Merge branch 'rework/printk_safe-removal' into for-linus
[linux-2.6-microblaze.git] / net / core / dev.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      NET3    Protocol independent device support routines.
4  *
5  *      Derived from the non IP parts of dev.c 1.0.19
6  *              Authors:        Ross Biro
7  *                              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
8  *                              Mark Evans, <evansmp@uhura.aston.ac.uk>
9  *
10  *      Additional Authors:
11  *              Florian la Roche <rzsfl@rz.uni-sb.de>
12  *              Alan Cox <gw4pts@gw4pts.ampr.org>
13  *              David Hinds <dahinds@users.sourceforge.net>
14  *              Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
15  *              Adam Sulmicki <adam@cfar.umd.edu>
16  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
17  *
18  *      Changes:
19  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
20  *                                      to 2 if register_netdev gets called
21  *                                      before net_dev_init & also removed a
22  *                                      few lines of code in the process.
23  *              Alan Cox        :       device private ioctl copies fields back.
24  *              Alan Cox        :       Transmit queue code does relevant
25  *                                      stunts to keep the queue safe.
26  *              Alan Cox        :       Fixed double lock.
27  *              Alan Cox        :       Fixed promisc NULL pointer trap
28  *              ????????        :       Support the full private ioctl range
29  *              Alan Cox        :       Moved ioctl permission check into
30  *                                      drivers
31  *              Tim Kordas      :       SIOCADDMULTI/SIOCDELMULTI
32  *              Alan Cox        :       100 backlog just doesn't cut it when
33  *                                      you start doing multicast video 8)
34  *              Alan Cox        :       Rewrote net_bh and list manager.
35  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
36  *              Alan Cox        :       Took out transmit every packet pass
37  *                                      Saved a few bytes in the ioctl handler
38  *              Alan Cox        :       Network driver sets packet type before
39  *                                      calling netif_rx. Saves a function
40  *                                      call a packet.
41  *              Alan Cox        :       Hashed net_bh()
42  *              Richard Kooijman:       Timestamp fixes.
43  *              Alan Cox        :       Wrong field in SIOCGIFDSTADDR
44  *              Alan Cox        :       Device lock protection.
45  *              Alan Cox        :       Fixed nasty side effect of device close
46  *                                      changes.
47  *              Rudi Cilibrasi  :       Pass the right thing to
48  *                                      set_mac_address()
49  *              Dave Miller     :       32bit quantity for the device lock to
50  *                                      make it work out on a Sparc.
51  *              Bjorn Ekwall    :       Added KERNELD hack.
52  *              Alan Cox        :       Cleaned up the backlog initialise.
53  *              Craig Metz      :       SIOCGIFCONF fix if space for under
54  *                                      1 device.
55  *          Thomas Bogendoerfer :       Return ENODEV for dev_open, if there
56  *                                      is no device open function.
57  *              Andi Kleen      :       Fix error reporting for SIOCGIFCONF
58  *          Michael Chastain    :       Fix signed/unsigned for SIOCGIFCONF
59  *              Cyrus Durgin    :       Cleaned for KMOD
60  *              Adam Sulmicki   :       Bug Fix : Network Device Unload
61  *                                      A network device unload needs to purge
62  *                                      the backlog queue.
63  *      Paul Rusty Russell      :       SIOCSIFNAME
64  *              Pekka Riikonen  :       Netdev boot-time settings code
65  *              Andrew Morton   :       Make unregister_netdevice wait
66  *                                      indefinitely on dev->refcnt
67  *              J Hadi Salim    :       - Backlog queue sampling
68  *                                      - netif_rx() feedback
69  */
70
71 #include <linux/uaccess.h>
72 #include <linux/bitops.h>
73 #include <linux/capability.h>
74 #include <linux/cpu.h>
75 #include <linux/types.h>
76 #include <linux/kernel.h>
77 #include <linux/hash.h>
78 #include <linux/slab.h>
79 #include <linux/sched.h>
80 #include <linux/sched/mm.h>
81 #include <linux/mutex.h>
82 #include <linux/rwsem.h>
83 #include <linux/string.h>
84 #include <linux/mm.h>
85 #include <linux/socket.h>
86 #include <linux/sockios.h>
87 #include <linux/errno.h>
88 #include <linux/interrupt.h>
89 #include <linux/if_ether.h>
90 #include <linux/netdevice.h>
91 #include <linux/etherdevice.h>
92 #include <linux/ethtool.h>
93 #include <linux/skbuff.h>
94 #include <linux/kthread.h>
95 #include <linux/bpf.h>
96 #include <linux/bpf_trace.h>
97 #include <net/net_namespace.h>
98 #include <net/sock.h>
99 #include <net/busy_poll.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/stat.h>
102 #include <net/dsa.h>
103 #include <net/dst.h>
104 #include <net/dst_metadata.h>
105 #include <net/gro.h>
106 #include <net/pkt_sched.h>
107 #include <net/pkt_cls.h>
108 #include <net/checksum.h>
109 #include <net/xfrm.h>
110 #include <linux/highmem.h>
111 #include <linux/init.h>
112 #include <linux/module.h>
113 #include <linux/netpoll.h>
114 #include <linux/rcupdate.h>
115 #include <linux/delay.h>
116 #include <net/iw_handler.h>
117 #include <asm/current.h>
118 #include <linux/audit.h>
119 #include <linux/dmaengine.h>
120 #include <linux/err.h>
121 #include <linux/ctype.h>
122 #include <linux/if_arp.h>
123 #include <linux/if_vlan.h>
124 #include <linux/ip.h>
125 #include <net/ip.h>
126 #include <net/mpls.h>
127 #include <linux/ipv6.h>
128 #include <linux/in.h>
129 #include <linux/jhash.h>
130 #include <linux/random.h>
131 #include <trace/events/napi.h>
132 #include <trace/events/net.h>
133 #include <trace/events/skb.h>
134 #include <trace/events/qdisc.h>
135 #include <linux/inetdevice.h>
136 #include <linux/cpu_rmap.h>
137 #include <linux/static_key.h>
138 #include <linux/hashtable.h>
139 #include <linux/vmalloc.h>
140 #include <linux/if_macvlan.h>
141 #include <linux/errqueue.h>
142 #include <linux/hrtimer.h>
143 #include <linux/netfilter_netdev.h>
144 #include <linux/crash_dump.h>
145 #include <linux/sctp.h>
146 #include <net/udp_tunnel.h>
147 #include <linux/net_namespace.h>
148 #include <linux/indirect_call_wrapper.h>
149 #include <net/devlink.h>
150 #include <linux/pm_runtime.h>
151 #include <linux/prandom.h>
152 #include <linux/once_lite.h>
153
154 #include "net-sysfs.h"
155
156 #define MAX_GRO_SKBS 8
157
158 /* This should be increased if a protocol with a bigger head is added. */
159 #define GRO_MAX_HEAD (MAX_HEADER + 128)
160
161 static DEFINE_SPINLOCK(ptype_lock);
162 static DEFINE_SPINLOCK(offload_lock);
163 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
164 struct list_head ptype_all __read_mostly;       /* Taps */
165 static struct list_head offload_base __read_mostly;
166
167 static int netif_rx_internal(struct sk_buff *skb);
168 static int call_netdevice_notifiers_info(unsigned long val,
169                                          struct netdev_notifier_info *info);
170 static int call_netdevice_notifiers_extack(unsigned long val,
171                                            struct net_device *dev,
172                                            struct netlink_ext_ack *extack);
173 static struct napi_struct *napi_by_id(unsigned int napi_id);
174
175 /*
176  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
177  * semaphore.
178  *
179  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
180  *
181  * Writers must hold the rtnl semaphore while they loop through the
182  * dev_base_head list, and hold dev_base_lock for writing when they do the
183  * actual updates.  This allows pure readers to access the list even
184  * while a writer is preparing to update it.
185  *
186  * To put it another way, dev_base_lock is held for writing only to
187  * protect against pure readers; the rtnl semaphore provides the
188  * protection against other writers.
189  *
190  * See, for example usages, register_netdevice() and
191  * unregister_netdevice(), which must be called with the rtnl
192  * semaphore held.
193  */
194 DEFINE_RWLOCK(dev_base_lock);
195 EXPORT_SYMBOL(dev_base_lock);
196
197 static DEFINE_MUTEX(ifalias_mutex);
198
199 /* protects napi_hash addition/deletion and napi_gen_id */
200 static DEFINE_SPINLOCK(napi_hash_lock);
201
202 static unsigned int napi_gen_id = NR_CPUS;
203 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
204
205 static DECLARE_RWSEM(devnet_rename_sem);
206
207 static inline void dev_base_seq_inc(struct net *net)
208 {
209         while (++net->dev_base_seq == 0)
210                 ;
211 }
212
213 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
214 {
215         unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
216
217         return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
218 }
219
220 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
221 {
222         return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
223 }
224
225 static inline void rps_lock(struct softnet_data *sd)
226 {
227 #ifdef CONFIG_RPS
228         spin_lock(&sd->input_pkt_queue.lock);
229 #endif
230 }
231
232 static inline void rps_unlock(struct softnet_data *sd)
233 {
234 #ifdef CONFIG_RPS
235         spin_unlock(&sd->input_pkt_queue.lock);
236 #endif
237 }
238
239 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
240                                                        const char *name)
241 {
242         struct netdev_name_node *name_node;
243
244         name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
245         if (!name_node)
246                 return NULL;
247         INIT_HLIST_NODE(&name_node->hlist);
248         name_node->dev = dev;
249         name_node->name = name;
250         return name_node;
251 }
252
253 static struct netdev_name_node *
254 netdev_name_node_head_alloc(struct net_device *dev)
255 {
256         struct netdev_name_node *name_node;
257
258         name_node = netdev_name_node_alloc(dev, dev->name);
259         if (!name_node)
260                 return NULL;
261         INIT_LIST_HEAD(&name_node->list);
262         return name_node;
263 }
264
265 static void netdev_name_node_free(struct netdev_name_node *name_node)
266 {
267         kfree(name_node);
268 }
269
270 static void netdev_name_node_add(struct net *net,
271                                  struct netdev_name_node *name_node)
272 {
273         hlist_add_head_rcu(&name_node->hlist,
274                            dev_name_hash(net, name_node->name));
275 }
276
277 static void netdev_name_node_del(struct netdev_name_node *name_node)
278 {
279         hlist_del_rcu(&name_node->hlist);
280 }
281
282 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
283                                                         const char *name)
284 {
285         struct hlist_head *head = dev_name_hash(net, name);
286         struct netdev_name_node *name_node;
287
288         hlist_for_each_entry(name_node, head, hlist)
289                 if (!strcmp(name_node->name, name))
290                         return name_node;
291         return NULL;
292 }
293
294 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
295                                                             const char *name)
296 {
297         struct hlist_head *head = dev_name_hash(net, name);
298         struct netdev_name_node *name_node;
299
300         hlist_for_each_entry_rcu(name_node, head, hlist)
301                 if (!strcmp(name_node->name, name))
302                         return name_node;
303         return NULL;
304 }
305
306 bool netdev_name_in_use(struct net *net, const char *name)
307 {
308         return netdev_name_node_lookup(net, name);
309 }
310 EXPORT_SYMBOL(netdev_name_in_use);
311
312 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
313 {
314         struct netdev_name_node *name_node;
315         struct net *net = dev_net(dev);
316
317         name_node = netdev_name_node_lookup(net, name);
318         if (name_node)
319                 return -EEXIST;
320         name_node = netdev_name_node_alloc(dev, name);
321         if (!name_node)
322                 return -ENOMEM;
323         netdev_name_node_add(net, name_node);
324         /* The node that holds dev->name acts as a head of per-device list. */
325         list_add_tail(&name_node->list, &dev->name_node->list);
326
327         return 0;
328 }
329 EXPORT_SYMBOL(netdev_name_node_alt_create);
330
331 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
332 {
333         list_del(&name_node->list);
334         netdev_name_node_del(name_node);
335         kfree(name_node->name);
336         netdev_name_node_free(name_node);
337 }
338
339 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
340 {
341         struct netdev_name_node *name_node;
342         struct net *net = dev_net(dev);
343
344         name_node = netdev_name_node_lookup(net, name);
345         if (!name_node)
346                 return -ENOENT;
347         /* lookup might have found our primary name or a name belonging
348          * to another device.
349          */
350         if (name_node == dev->name_node || name_node->dev != dev)
351                 return -EINVAL;
352
353         __netdev_name_node_alt_destroy(name_node);
354
355         return 0;
356 }
357 EXPORT_SYMBOL(netdev_name_node_alt_destroy);
358
359 static void netdev_name_node_alt_flush(struct net_device *dev)
360 {
361         struct netdev_name_node *name_node, *tmp;
362
363         list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
364                 __netdev_name_node_alt_destroy(name_node);
365 }
366
367 /* Device list insertion */
368 static void list_netdevice(struct net_device *dev)
369 {
370         struct net *net = dev_net(dev);
371
372         ASSERT_RTNL();
373
374         write_lock_bh(&dev_base_lock);
375         list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
376         netdev_name_node_add(net, dev->name_node);
377         hlist_add_head_rcu(&dev->index_hlist,
378                            dev_index_hash(net, dev->ifindex));
379         write_unlock_bh(&dev_base_lock);
380
381         dev_base_seq_inc(net);
382 }
383
384 /* Device list removal
385  * caller must respect a RCU grace period before freeing/reusing dev
386  */
387 static void unlist_netdevice(struct net_device *dev)
388 {
389         ASSERT_RTNL();
390
391         /* Unlink dev from the device chain */
392         write_lock_bh(&dev_base_lock);
393         list_del_rcu(&dev->dev_list);
394         netdev_name_node_del(dev->name_node);
395         hlist_del_rcu(&dev->index_hlist);
396         write_unlock_bh(&dev_base_lock);
397
398         dev_base_seq_inc(dev_net(dev));
399 }
400
401 /*
402  *      Our notifier list
403  */
404
405 static RAW_NOTIFIER_HEAD(netdev_chain);
406
407 /*
408  *      Device drivers call our routines to queue packets here. We empty the
409  *      queue in the local softnet handler.
410  */
411
412 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
413 EXPORT_PER_CPU_SYMBOL(softnet_data);
414
415 #ifdef CONFIG_LOCKDEP
416 /*
417  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
418  * according to dev->type
419  */
420 static const unsigned short netdev_lock_type[] = {
421          ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
422          ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
423          ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
424          ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
425          ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
426          ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
427          ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
428          ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
429          ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
430          ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
431          ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
432          ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
433          ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
434          ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
435          ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
436
437 static const char *const netdev_lock_name[] = {
438         "_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
439         "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
440         "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
441         "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
442         "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
443         "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
444         "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
445         "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
446         "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
447         "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
448         "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
449         "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
450         "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
451         "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
452         "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
453
454 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
455 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
456
457 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
458 {
459         int i;
460
461         for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
462                 if (netdev_lock_type[i] == dev_type)
463                         return i;
464         /* the last key is used by default */
465         return ARRAY_SIZE(netdev_lock_type) - 1;
466 }
467
468 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
469                                                  unsigned short dev_type)
470 {
471         int i;
472
473         i = netdev_lock_pos(dev_type);
474         lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
475                                    netdev_lock_name[i]);
476 }
477
478 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
479 {
480         int i;
481
482         i = netdev_lock_pos(dev->type);
483         lockdep_set_class_and_name(&dev->addr_list_lock,
484                                    &netdev_addr_lock_key[i],
485                                    netdev_lock_name[i]);
486 }
487 #else
488 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
489                                                  unsigned short dev_type)
490 {
491 }
492
493 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
494 {
495 }
496 #endif
497
498 /*******************************************************************************
499  *
500  *              Protocol management and registration routines
501  *
502  *******************************************************************************/
503
504
505 /*
506  *      Add a protocol ID to the list. Now that the input handler is
507  *      smarter we can dispense with all the messy stuff that used to be
508  *      here.
509  *
510  *      BEWARE!!! Protocol handlers, mangling input packets,
511  *      MUST BE last in hash buckets and checking protocol handlers
512  *      MUST start from promiscuous ptype_all chain in net_bh.
513  *      It is true now, do not change it.
514  *      Explanation follows: if protocol handler, mangling packet, will
515  *      be the first on list, it is not able to sense, that packet
516  *      is cloned and should be copied-on-write, so that it will
517  *      change it and subsequent readers will get broken packet.
518  *                                                      --ANK (980803)
519  */
520
521 static inline struct list_head *ptype_head(const struct packet_type *pt)
522 {
523         if (pt->type == htons(ETH_P_ALL))
524                 return pt->dev ? &pt->dev->ptype_all : &ptype_all;
525         else
526                 return pt->dev ? &pt->dev->ptype_specific :
527                                  &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
528 }
529
530 /**
531  *      dev_add_pack - add packet handler
532  *      @pt: packet type declaration
533  *
534  *      Add a protocol handler to the networking stack. The passed &packet_type
535  *      is linked into kernel lists and may not be freed until it has been
536  *      removed from the kernel lists.
537  *
538  *      This call does not sleep therefore it can not
539  *      guarantee all CPU's that are in middle of receiving packets
540  *      will see the new packet type (until the next received packet).
541  */
542
543 void dev_add_pack(struct packet_type *pt)
544 {
545         struct list_head *head = ptype_head(pt);
546
547         spin_lock(&ptype_lock);
548         list_add_rcu(&pt->list, head);
549         spin_unlock(&ptype_lock);
550 }
551 EXPORT_SYMBOL(dev_add_pack);
552
553 /**
554  *      __dev_remove_pack        - remove packet handler
555  *      @pt: packet type declaration
556  *
557  *      Remove a protocol handler that was previously added to the kernel
558  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
559  *      from the kernel lists and can be freed or reused once this function
560  *      returns.
561  *
562  *      The packet type might still be in use by receivers
563  *      and must not be freed until after all the CPU's have gone
564  *      through a quiescent state.
565  */
566 void __dev_remove_pack(struct packet_type *pt)
567 {
568         struct list_head *head = ptype_head(pt);
569         struct packet_type *pt1;
570
571         spin_lock(&ptype_lock);
572
573         list_for_each_entry(pt1, head, list) {
574                 if (pt == pt1) {
575                         list_del_rcu(&pt->list);
576                         goto out;
577                 }
578         }
579
580         pr_warn("dev_remove_pack: %p not found\n", pt);
581 out:
582         spin_unlock(&ptype_lock);
583 }
584 EXPORT_SYMBOL(__dev_remove_pack);
585
586 /**
587  *      dev_remove_pack  - remove packet handler
588  *      @pt: packet type declaration
589  *
590  *      Remove a protocol handler that was previously added to the kernel
591  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
592  *      from the kernel lists and can be freed or reused once this function
593  *      returns.
594  *
595  *      This call sleeps to guarantee that no CPU is looking at the packet
596  *      type after return.
597  */
598 void dev_remove_pack(struct packet_type *pt)
599 {
600         __dev_remove_pack(pt);
601
602         synchronize_net();
603 }
604 EXPORT_SYMBOL(dev_remove_pack);
605
606
607 /**
608  *      dev_add_offload - register offload handlers
609  *      @po: protocol offload declaration
610  *
611  *      Add protocol offload handlers to the networking stack. The passed
612  *      &proto_offload is linked into kernel lists and may not be freed until
613  *      it has been removed from the kernel lists.
614  *
615  *      This call does not sleep therefore it can not
616  *      guarantee all CPU's that are in middle of receiving packets
617  *      will see the new offload handlers (until the next received packet).
618  */
619 void dev_add_offload(struct packet_offload *po)
620 {
621         struct packet_offload *elem;
622
623         spin_lock(&offload_lock);
624         list_for_each_entry(elem, &offload_base, list) {
625                 if (po->priority < elem->priority)
626                         break;
627         }
628         list_add_rcu(&po->list, elem->list.prev);
629         spin_unlock(&offload_lock);
630 }
631 EXPORT_SYMBOL(dev_add_offload);
632
633 /**
634  *      __dev_remove_offload     - remove offload handler
635  *      @po: packet offload declaration
636  *
637  *      Remove a protocol offload handler that was previously added to the
638  *      kernel offload handlers by dev_add_offload(). The passed &offload_type
639  *      is removed from the kernel lists and can be freed or reused once this
640  *      function returns.
641  *
642  *      The packet type might still be in use by receivers
643  *      and must not be freed until after all the CPU's have gone
644  *      through a quiescent state.
645  */
646 static void __dev_remove_offload(struct packet_offload *po)
647 {
648         struct list_head *head = &offload_base;
649         struct packet_offload *po1;
650
651         spin_lock(&offload_lock);
652
653         list_for_each_entry(po1, head, list) {
654                 if (po == po1) {
655                         list_del_rcu(&po->list);
656                         goto out;
657                 }
658         }
659
660         pr_warn("dev_remove_offload: %p not found\n", po);
661 out:
662         spin_unlock(&offload_lock);
663 }
664
665 /**
666  *      dev_remove_offload       - remove packet offload handler
667  *      @po: packet offload declaration
668  *
669  *      Remove a packet offload handler that was previously added to the kernel
670  *      offload handlers by dev_add_offload(). The passed &offload_type is
671  *      removed from the kernel lists and can be freed or reused once this
672  *      function returns.
673  *
674  *      This call sleeps to guarantee that no CPU is looking at the packet
675  *      type after return.
676  */
677 void dev_remove_offload(struct packet_offload *po)
678 {
679         __dev_remove_offload(po);
680
681         synchronize_net();
682 }
683 EXPORT_SYMBOL(dev_remove_offload);
684
685 /*******************************************************************************
686  *
687  *                          Device Interface Subroutines
688  *
689  *******************************************************************************/
690
691 /**
692  *      dev_get_iflink  - get 'iflink' value of a interface
693  *      @dev: targeted interface
694  *
695  *      Indicates the ifindex the interface is linked to.
696  *      Physical interfaces have the same 'ifindex' and 'iflink' values.
697  */
698
699 int dev_get_iflink(const struct net_device *dev)
700 {
701         if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
702                 return dev->netdev_ops->ndo_get_iflink(dev);
703
704         return dev->ifindex;
705 }
706 EXPORT_SYMBOL(dev_get_iflink);
707
708 /**
709  *      dev_fill_metadata_dst - Retrieve tunnel egress information.
710  *      @dev: targeted interface
711  *      @skb: The packet.
712  *
713  *      For better visibility of tunnel traffic OVS needs to retrieve
714  *      egress tunnel information for a packet. Following API allows
715  *      user to get this info.
716  */
717 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
718 {
719         struct ip_tunnel_info *info;
720
721         if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
722                 return -EINVAL;
723
724         info = skb_tunnel_info_unclone(skb);
725         if (!info)
726                 return -ENOMEM;
727         if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
728                 return -EINVAL;
729
730         return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
731 }
732 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
733
734 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
735 {
736         int k = stack->num_paths++;
737
738         if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
739                 return NULL;
740
741         return &stack->path[k];
742 }
743
744 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
745                           struct net_device_path_stack *stack)
746 {
747         const struct net_device *last_dev;
748         struct net_device_path_ctx ctx = {
749                 .dev    = dev,
750                 .daddr  = daddr,
751         };
752         struct net_device_path *path;
753         int ret = 0;
754
755         stack->num_paths = 0;
756         while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
757                 last_dev = ctx.dev;
758                 path = dev_fwd_path(stack);
759                 if (!path)
760                         return -1;
761
762                 memset(path, 0, sizeof(struct net_device_path));
763                 ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
764                 if (ret < 0)
765                         return -1;
766
767                 if (WARN_ON_ONCE(last_dev == ctx.dev))
768                         return -1;
769         }
770         path = dev_fwd_path(stack);
771         if (!path)
772                 return -1;
773         path->type = DEV_PATH_ETHERNET;
774         path->dev = ctx.dev;
775
776         return ret;
777 }
778 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
779
780 /**
781  *      __dev_get_by_name       - find a device by its name
782  *      @net: the applicable net namespace
783  *      @name: name to find
784  *
785  *      Find an interface by name. Must be called under RTNL semaphore
786  *      or @dev_base_lock. If the name is found a pointer to the device
787  *      is returned. If the name is not found then %NULL is returned. The
788  *      reference counters are not incremented so the caller must be
789  *      careful with locks.
790  */
791
792 struct net_device *__dev_get_by_name(struct net *net, const char *name)
793 {
794         struct netdev_name_node *node_name;
795
796         node_name = netdev_name_node_lookup(net, name);
797         return node_name ? node_name->dev : NULL;
798 }
799 EXPORT_SYMBOL(__dev_get_by_name);
800
801 /**
802  * dev_get_by_name_rcu  - find a device by its name
803  * @net: the applicable net namespace
804  * @name: name to find
805  *
806  * Find an interface by name.
807  * If the name is found a pointer to the device is returned.
808  * If the name is not found then %NULL is returned.
809  * The reference counters are not incremented so the caller must be
810  * careful with locks. The caller must hold RCU lock.
811  */
812
813 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
814 {
815         struct netdev_name_node *node_name;
816
817         node_name = netdev_name_node_lookup_rcu(net, name);
818         return node_name ? node_name->dev : NULL;
819 }
820 EXPORT_SYMBOL(dev_get_by_name_rcu);
821
822 /**
823  *      dev_get_by_name         - find a device by its name
824  *      @net: the applicable net namespace
825  *      @name: name to find
826  *
827  *      Find an interface by name. This can be called from any
828  *      context and does its own locking. The returned handle has
829  *      the usage count incremented and the caller must use dev_put() to
830  *      release it when it is no longer needed. %NULL is returned if no
831  *      matching device is found.
832  */
833
834 struct net_device *dev_get_by_name(struct net *net, const char *name)
835 {
836         struct net_device *dev;
837
838         rcu_read_lock();
839         dev = dev_get_by_name_rcu(net, name);
840         dev_hold(dev);
841         rcu_read_unlock();
842         return dev;
843 }
844 EXPORT_SYMBOL(dev_get_by_name);
845
846 /**
847  *      __dev_get_by_index - find a device by its ifindex
848  *      @net: the applicable net namespace
849  *      @ifindex: index of device
850  *
851  *      Search for an interface by index. Returns %NULL if the device
852  *      is not found or a pointer to the device. The device has not
853  *      had its reference counter increased so the caller must be careful
854  *      about locking. The caller must hold either the RTNL semaphore
855  *      or @dev_base_lock.
856  */
857
858 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
859 {
860         struct net_device *dev;
861         struct hlist_head *head = dev_index_hash(net, ifindex);
862
863         hlist_for_each_entry(dev, head, index_hlist)
864                 if (dev->ifindex == ifindex)
865                         return dev;
866
867         return NULL;
868 }
869 EXPORT_SYMBOL(__dev_get_by_index);
870
871 /**
872  *      dev_get_by_index_rcu - find a device by its ifindex
873  *      @net: the applicable net namespace
874  *      @ifindex: index of device
875  *
876  *      Search for an interface by index. Returns %NULL if the device
877  *      is not found or a pointer to the device. The device has not
878  *      had its reference counter increased so the caller must be careful
879  *      about locking. The caller must hold RCU lock.
880  */
881
882 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
883 {
884         struct net_device *dev;
885         struct hlist_head *head = dev_index_hash(net, ifindex);
886
887         hlist_for_each_entry_rcu(dev, head, index_hlist)
888                 if (dev->ifindex == ifindex)
889                         return dev;
890
891         return NULL;
892 }
893 EXPORT_SYMBOL(dev_get_by_index_rcu);
894
895
896 /**
897  *      dev_get_by_index - find a device by its ifindex
898  *      @net: the applicable net namespace
899  *      @ifindex: index of device
900  *
901  *      Search for an interface by index. Returns NULL if the device
902  *      is not found or a pointer to the device. The device returned has
903  *      had a reference added and the pointer is safe until the user calls
904  *      dev_put to indicate they have finished with it.
905  */
906
907 struct net_device *dev_get_by_index(struct net *net, int ifindex)
908 {
909         struct net_device *dev;
910
911         rcu_read_lock();
912         dev = dev_get_by_index_rcu(net, ifindex);
913         dev_hold(dev);
914         rcu_read_unlock();
915         return dev;
916 }
917 EXPORT_SYMBOL(dev_get_by_index);
918
919 /**
920  *      dev_get_by_napi_id - find a device by napi_id
921  *      @napi_id: ID of the NAPI struct
922  *
923  *      Search for an interface by NAPI ID. Returns %NULL if the device
924  *      is not found or a pointer to the device. The device has not had
925  *      its reference counter increased so the caller must be careful
926  *      about locking. The caller must hold RCU lock.
927  */
928
929 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
930 {
931         struct napi_struct *napi;
932
933         WARN_ON_ONCE(!rcu_read_lock_held());
934
935         if (napi_id < MIN_NAPI_ID)
936                 return NULL;
937
938         napi = napi_by_id(napi_id);
939
940         return napi ? napi->dev : NULL;
941 }
942 EXPORT_SYMBOL(dev_get_by_napi_id);
943
944 /**
945  *      netdev_get_name - get a netdevice name, knowing its ifindex.
946  *      @net: network namespace
947  *      @name: a pointer to the buffer where the name will be stored.
948  *      @ifindex: the ifindex of the interface to get the name from.
949  */
950 int netdev_get_name(struct net *net, char *name, int ifindex)
951 {
952         struct net_device *dev;
953         int ret;
954
955         down_read(&devnet_rename_sem);
956         rcu_read_lock();
957
958         dev = dev_get_by_index_rcu(net, ifindex);
959         if (!dev) {
960                 ret = -ENODEV;
961                 goto out;
962         }
963
964         strcpy(name, dev->name);
965
966         ret = 0;
967 out:
968         rcu_read_unlock();
969         up_read(&devnet_rename_sem);
970         return ret;
971 }
972
973 /**
974  *      dev_getbyhwaddr_rcu - find a device by its hardware address
975  *      @net: the applicable net namespace
976  *      @type: media type of device
977  *      @ha: hardware address
978  *
979  *      Search for an interface by MAC address. Returns NULL if the device
980  *      is not found or a pointer to the device.
981  *      The caller must hold RCU or RTNL.
982  *      The returned device has not had its ref count increased
983  *      and the caller must therefore be careful about locking
984  *
985  */
986
987 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
988                                        const char *ha)
989 {
990         struct net_device *dev;
991
992         for_each_netdev_rcu(net, dev)
993                 if (dev->type == type &&
994                     !memcmp(dev->dev_addr, ha, dev->addr_len))
995                         return dev;
996
997         return NULL;
998 }
999 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
1000
1001 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
1002 {
1003         struct net_device *dev, *ret = NULL;
1004
1005         rcu_read_lock();
1006         for_each_netdev_rcu(net, dev)
1007                 if (dev->type == type) {
1008                         dev_hold(dev);
1009                         ret = dev;
1010                         break;
1011                 }
1012         rcu_read_unlock();
1013         return ret;
1014 }
1015 EXPORT_SYMBOL(dev_getfirstbyhwtype);
1016
1017 /**
1018  *      __dev_get_by_flags - find any device with given flags
1019  *      @net: the applicable net namespace
1020  *      @if_flags: IFF_* values
1021  *      @mask: bitmask of bits in if_flags to check
1022  *
1023  *      Search for any interface with the given flags. Returns NULL if a device
1024  *      is not found or a pointer to the device. Must be called inside
1025  *      rtnl_lock(), and result refcount is unchanged.
1026  */
1027
1028 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
1029                                       unsigned short mask)
1030 {
1031         struct net_device *dev, *ret;
1032
1033         ASSERT_RTNL();
1034
1035         ret = NULL;
1036         for_each_netdev(net, dev) {
1037                 if (((dev->flags ^ if_flags) & mask) == 0) {
1038                         ret = dev;
1039                         break;
1040                 }
1041         }
1042         return ret;
1043 }
1044 EXPORT_SYMBOL(__dev_get_by_flags);
1045
1046 /**
1047  *      dev_valid_name - check if name is okay for network device
1048  *      @name: name string
1049  *
1050  *      Network device names need to be valid file names to
1051  *      allow sysfs to work.  We also disallow any kind of
1052  *      whitespace.
1053  */
1054 bool dev_valid_name(const char *name)
1055 {
1056         if (*name == '\0')
1057                 return false;
1058         if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1059                 return false;
1060         if (!strcmp(name, ".") || !strcmp(name, ".."))
1061                 return false;
1062
1063         while (*name) {
1064                 if (*name == '/' || *name == ':' || isspace(*name))
1065                         return false;
1066                 name++;
1067         }
1068         return true;
1069 }
1070 EXPORT_SYMBOL(dev_valid_name);
1071
1072 /**
1073  *      __dev_alloc_name - allocate a name for a device
1074  *      @net: network namespace to allocate the device name in
1075  *      @name: name format string
1076  *      @buf:  scratch buffer and result name string
1077  *
1078  *      Passed a format string - eg "lt%d" it will try and find a suitable
1079  *      id. It scans list of devices to build up a free map, then chooses
1080  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1081  *      while allocating the name and adding the device in order to avoid
1082  *      duplicates.
1083  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1084  *      Returns the number of the unit assigned or a negative errno code.
1085  */
1086
1087 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1088 {
1089         int i = 0;
1090         const char *p;
1091         const int max_netdevices = 8*PAGE_SIZE;
1092         unsigned long *inuse;
1093         struct net_device *d;
1094
1095         if (!dev_valid_name(name))
1096                 return -EINVAL;
1097
1098         p = strchr(name, '%');
1099         if (p) {
1100                 /*
1101                  * Verify the string as this thing may have come from
1102                  * the user.  There must be either one "%d" and no other "%"
1103                  * characters.
1104                  */
1105                 if (p[1] != 'd' || strchr(p + 2, '%'))
1106                         return -EINVAL;
1107
1108                 /* Use one page as a bit array of possible slots */
1109                 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1110                 if (!inuse)
1111                         return -ENOMEM;
1112
1113                 for_each_netdev(net, d) {
1114                         struct netdev_name_node *name_node;
1115                         list_for_each_entry(name_node, &d->name_node->list, list) {
1116                                 if (!sscanf(name_node->name, name, &i))
1117                                         continue;
1118                                 if (i < 0 || i >= max_netdevices)
1119                                         continue;
1120
1121                                 /*  avoid cases where sscanf is not exact inverse of printf */
1122                                 snprintf(buf, IFNAMSIZ, name, i);
1123                                 if (!strncmp(buf, name_node->name, IFNAMSIZ))
1124                                         set_bit(i, inuse);
1125                         }
1126                         if (!sscanf(d->name, name, &i))
1127                                 continue;
1128                         if (i < 0 || i >= max_netdevices)
1129                                 continue;
1130
1131                         /*  avoid cases where sscanf is not exact inverse of printf */
1132                         snprintf(buf, IFNAMSIZ, name, i);
1133                         if (!strncmp(buf, d->name, IFNAMSIZ))
1134                                 set_bit(i, inuse);
1135                 }
1136
1137                 i = find_first_zero_bit(inuse, max_netdevices);
1138                 free_page((unsigned long) inuse);
1139         }
1140
1141         snprintf(buf, IFNAMSIZ, name, i);
1142         if (!netdev_name_in_use(net, buf))
1143                 return i;
1144
1145         /* It is possible to run out of possible slots
1146          * when the name is long and there isn't enough space left
1147          * for the digits, or if all bits are used.
1148          */
1149         return -ENFILE;
1150 }
1151
1152 static int dev_alloc_name_ns(struct net *net,
1153                              struct net_device *dev,
1154                              const char *name)
1155 {
1156         char buf[IFNAMSIZ];
1157         int ret;
1158
1159         BUG_ON(!net);
1160         ret = __dev_alloc_name(net, name, buf);
1161         if (ret >= 0)
1162                 strlcpy(dev->name, buf, IFNAMSIZ);
1163         return ret;
1164 }
1165
1166 /**
1167  *      dev_alloc_name - allocate a name for a device
1168  *      @dev: device
1169  *      @name: name format string
1170  *
1171  *      Passed a format string - eg "lt%d" it will try and find a suitable
1172  *      id. It scans list of devices to build up a free map, then chooses
1173  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1174  *      while allocating the name and adding the device in order to avoid
1175  *      duplicates.
1176  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1177  *      Returns the number of the unit assigned or a negative errno code.
1178  */
1179
1180 int dev_alloc_name(struct net_device *dev, const char *name)
1181 {
1182         return dev_alloc_name_ns(dev_net(dev), dev, name);
1183 }
1184 EXPORT_SYMBOL(dev_alloc_name);
1185
1186 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1187                               const char *name)
1188 {
1189         BUG_ON(!net);
1190
1191         if (!dev_valid_name(name))
1192                 return -EINVAL;
1193
1194         if (strchr(name, '%'))
1195                 return dev_alloc_name_ns(net, dev, name);
1196         else if (netdev_name_in_use(net, name))
1197                 return -EEXIST;
1198         else if (dev->name != name)
1199                 strlcpy(dev->name, name, IFNAMSIZ);
1200
1201         return 0;
1202 }
1203
1204 /**
1205  *      dev_change_name - change name of a device
1206  *      @dev: device
1207  *      @newname: name (or format string) must be at least IFNAMSIZ
1208  *
1209  *      Change name of a device, can pass format strings "eth%d".
1210  *      for wildcarding.
1211  */
1212 int dev_change_name(struct net_device *dev, const char *newname)
1213 {
1214         unsigned char old_assign_type;
1215         char oldname[IFNAMSIZ];
1216         int err = 0;
1217         int ret;
1218         struct net *net;
1219
1220         ASSERT_RTNL();
1221         BUG_ON(!dev_net(dev));
1222
1223         net = dev_net(dev);
1224
1225         /* Some auto-enslaved devices e.g. failover slaves are
1226          * special, as userspace might rename the device after
1227          * the interface had been brought up and running since
1228          * the point kernel initiated auto-enslavement. Allow
1229          * live name change even when these slave devices are
1230          * up and running.
1231          *
1232          * Typically, users of these auto-enslaving devices
1233          * don't actually care about slave name change, as
1234          * they are supposed to operate on master interface
1235          * directly.
1236          */
1237         if (dev->flags & IFF_UP &&
1238             likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK)))
1239                 return -EBUSY;
1240
1241         down_write(&devnet_rename_sem);
1242
1243         if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1244                 up_write(&devnet_rename_sem);
1245                 return 0;
1246         }
1247
1248         memcpy(oldname, dev->name, IFNAMSIZ);
1249
1250         err = dev_get_valid_name(net, dev, newname);
1251         if (err < 0) {
1252                 up_write(&devnet_rename_sem);
1253                 return err;
1254         }
1255
1256         if (oldname[0] && !strchr(oldname, '%'))
1257                 netdev_info(dev, "renamed from %s\n", oldname);
1258
1259         old_assign_type = dev->name_assign_type;
1260         dev->name_assign_type = NET_NAME_RENAMED;
1261
1262 rollback:
1263         ret = device_rename(&dev->dev, dev->name);
1264         if (ret) {
1265                 memcpy(dev->name, oldname, IFNAMSIZ);
1266                 dev->name_assign_type = old_assign_type;
1267                 up_write(&devnet_rename_sem);
1268                 return ret;
1269         }
1270
1271         up_write(&devnet_rename_sem);
1272
1273         netdev_adjacent_rename_links(dev, oldname);
1274
1275         write_lock_bh(&dev_base_lock);
1276         netdev_name_node_del(dev->name_node);
1277         write_unlock_bh(&dev_base_lock);
1278
1279         synchronize_rcu();
1280
1281         write_lock_bh(&dev_base_lock);
1282         netdev_name_node_add(net, dev->name_node);
1283         write_unlock_bh(&dev_base_lock);
1284
1285         ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1286         ret = notifier_to_errno(ret);
1287
1288         if (ret) {
1289                 /* err >= 0 after dev_alloc_name() or stores the first errno */
1290                 if (err >= 0) {
1291                         err = ret;
1292                         down_write(&devnet_rename_sem);
1293                         memcpy(dev->name, oldname, IFNAMSIZ);
1294                         memcpy(oldname, newname, IFNAMSIZ);
1295                         dev->name_assign_type = old_assign_type;
1296                         old_assign_type = NET_NAME_RENAMED;
1297                         goto rollback;
1298                 } else {
1299                         netdev_err(dev, "name change rollback failed: %d\n",
1300                                    ret);
1301                 }
1302         }
1303
1304         return err;
1305 }
1306
1307 /**
1308  *      dev_set_alias - change ifalias of a device
1309  *      @dev: device
1310  *      @alias: name up to IFALIASZ
1311  *      @len: limit of bytes to copy from info
1312  *
1313  *      Set ifalias for a device,
1314  */
1315 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1316 {
1317         struct dev_ifalias *new_alias = NULL;
1318
1319         if (len >= IFALIASZ)
1320                 return -EINVAL;
1321
1322         if (len) {
1323                 new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1324                 if (!new_alias)
1325                         return -ENOMEM;
1326
1327                 memcpy(new_alias->ifalias, alias, len);
1328                 new_alias->ifalias[len] = 0;
1329         }
1330
1331         mutex_lock(&ifalias_mutex);
1332         new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1333                                         mutex_is_locked(&ifalias_mutex));
1334         mutex_unlock(&ifalias_mutex);
1335
1336         if (new_alias)
1337                 kfree_rcu(new_alias, rcuhead);
1338
1339         return len;
1340 }
1341 EXPORT_SYMBOL(dev_set_alias);
1342
1343 /**
1344  *      dev_get_alias - get ifalias of a device
1345  *      @dev: device
1346  *      @name: buffer to store name of ifalias
1347  *      @len: size of buffer
1348  *
1349  *      get ifalias for a device.  Caller must make sure dev cannot go
1350  *      away,  e.g. rcu read lock or own a reference count to device.
1351  */
1352 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1353 {
1354         const struct dev_ifalias *alias;
1355         int ret = 0;
1356
1357         rcu_read_lock();
1358         alias = rcu_dereference(dev->ifalias);
1359         if (alias)
1360                 ret = snprintf(name, len, "%s", alias->ifalias);
1361         rcu_read_unlock();
1362
1363         return ret;
1364 }
1365
1366 /**
1367  *      netdev_features_change - device changes features
1368  *      @dev: device to cause notification
1369  *
1370  *      Called to indicate a device has changed features.
1371  */
1372 void netdev_features_change(struct net_device *dev)
1373 {
1374         call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1375 }
1376 EXPORT_SYMBOL(netdev_features_change);
1377
1378 /**
1379  *      netdev_state_change - device changes state
1380  *      @dev: device to cause notification
1381  *
1382  *      Called to indicate a device has changed state. This function calls
1383  *      the notifier chains for netdev_chain and sends a NEWLINK message
1384  *      to the routing socket.
1385  */
1386 void netdev_state_change(struct net_device *dev)
1387 {
1388         if (dev->flags & IFF_UP) {
1389                 struct netdev_notifier_change_info change_info = {
1390                         .info.dev = dev,
1391                 };
1392
1393                 call_netdevice_notifiers_info(NETDEV_CHANGE,
1394                                               &change_info.info);
1395                 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
1396         }
1397 }
1398 EXPORT_SYMBOL(netdev_state_change);
1399
1400 /**
1401  * __netdev_notify_peers - notify network peers about existence of @dev,
1402  * to be called when rtnl lock is already held.
1403  * @dev: network device
1404  *
1405  * Generate traffic such that interested network peers are aware of
1406  * @dev, such as by generating a gratuitous ARP. This may be used when
1407  * a device wants to inform the rest of the network about some sort of
1408  * reconfiguration such as a failover event or virtual machine
1409  * migration.
1410  */
1411 void __netdev_notify_peers(struct net_device *dev)
1412 {
1413         ASSERT_RTNL();
1414         call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1415         call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1416 }
1417 EXPORT_SYMBOL(__netdev_notify_peers);
1418
1419 /**
1420  * netdev_notify_peers - notify network peers about existence of @dev
1421  * @dev: network device
1422  *
1423  * Generate traffic such that interested network peers are aware of
1424  * @dev, such as by generating a gratuitous ARP. This may be used when
1425  * a device wants to inform the rest of the network about some sort of
1426  * reconfiguration such as a failover event or virtual machine
1427  * migration.
1428  */
1429 void netdev_notify_peers(struct net_device *dev)
1430 {
1431         rtnl_lock();
1432         __netdev_notify_peers(dev);
1433         rtnl_unlock();
1434 }
1435 EXPORT_SYMBOL(netdev_notify_peers);
1436
1437 static int napi_threaded_poll(void *data);
1438
1439 static int napi_kthread_create(struct napi_struct *n)
1440 {
1441         int err = 0;
1442
1443         /* Create and wake up the kthread once to put it in
1444          * TASK_INTERRUPTIBLE mode to avoid the blocked task
1445          * warning and work with loadavg.
1446          */
1447         n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1448                                 n->dev->name, n->napi_id);
1449         if (IS_ERR(n->thread)) {
1450                 err = PTR_ERR(n->thread);
1451                 pr_err("kthread_run failed with err %d\n", err);
1452                 n->thread = NULL;
1453         }
1454
1455         return err;
1456 }
1457
1458 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1459 {
1460         const struct net_device_ops *ops = dev->netdev_ops;
1461         int ret;
1462
1463         ASSERT_RTNL();
1464
1465         if (!netif_device_present(dev)) {
1466                 /* may be detached because parent is runtime-suspended */
1467                 if (dev->dev.parent)
1468                         pm_runtime_resume(dev->dev.parent);
1469                 if (!netif_device_present(dev))
1470                         return -ENODEV;
1471         }
1472
1473         /* Block netpoll from trying to do any rx path servicing.
1474          * If we don't do this there is a chance ndo_poll_controller
1475          * or ndo_poll may be running while we open the device
1476          */
1477         netpoll_poll_disable(dev);
1478
1479         ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1480         ret = notifier_to_errno(ret);
1481         if (ret)
1482                 return ret;
1483
1484         set_bit(__LINK_STATE_START, &dev->state);
1485
1486         if (ops->ndo_validate_addr)
1487                 ret = ops->ndo_validate_addr(dev);
1488
1489         if (!ret && ops->ndo_open)
1490                 ret = ops->ndo_open(dev);
1491
1492         netpoll_poll_enable(dev);
1493
1494         if (ret)
1495                 clear_bit(__LINK_STATE_START, &dev->state);
1496         else {
1497                 dev->flags |= IFF_UP;
1498                 dev_set_rx_mode(dev);
1499                 dev_activate(dev);
1500                 add_device_randomness(dev->dev_addr, dev->addr_len);
1501         }
1502
1503         return ret;
1504 }
1505
1506 /**
1507  *      dev_open        - prepare an interface for use.
1508  *      @dev: device to open
1509  *      @extack: netlink extended ack
1510  *
1511  *      Takes a device from down to up state. The device's private open
1512  *      function is invoked and then the multicast lists are loaded. Finally
1513  *      the device is moved into the up state and a %NETDEV_UP message is
1514  *      sent to the netdev notifier chain.
1515  *
1516  *      Calling this function on an active interface is a nop. On a failure
1517  *      a negative errno code is returned.
1518  */
1519 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1520 {
1521         int ret;
1522
1523         if (dev->flags & IFF_UP)
1524                 return 0;
1525
1526         ret = __dev_open(dev, extack);
1527         if (ret < 0)
1528                 return ret;
1529
1530         rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1531         call_netdevice_notifiers(NETDEV_UP, dev);
1532
1533         return ret;
1534 }
1535 EXPORT_SYMBOL(dev_open);
1536
1537 static void __dev_close_many(struct list_head *head)
1538 {
1539         struct net_device *dev;
1540
1541         ASSERT_RTNL();
1542         might_sleep();
1543
1544         list_for_each_entry(dev, head, close_list) {
1545                 /* Temporarily disable netpoll until the interface is down */
1546                 netpoll_poll_disable(dev);
1547
1548                 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1549
1550                 clear_bit(__LINK_STATE_START, &dev->state);
1551
1552                 /* Synchronize to scheduled poll. We cannot touch poll list, it
1553                  * can be even on different cpu. So just clear netif_running().
1554                  *
1555                  * dev->stop() will invoke napi_disable() on all of it's
1556                  * napi_struct instances on this device.
1557                  */
1558                 smp_mb__after_atomic(); /* Commit netif_running(). */
1559         }
1560
1561         dev_deactivate_many(head);
1562
1563         list_for_each_entry(dev, head, close_list) {
1564                 const struct net_device_ops *ops = dev->netdev_ops;
1565
1566                 /*
1567                  *      Call the device specific close. This cannot fail.
1568                  *      Only if device is UP
1569                  *
1570                  *      We allow it to be called even after a DETACH hot-plug
1571                  *      event.
1572                  */
1573                 if (ops->ndo_stop)
1574                         ops->ndo_stop(dev);
1575
1576                 dev->flags &= ~IFF_UP;
1577                 netpoll_poll_enable(dev);
1578         }
1579 }
1580
1581 static void __dev_close(struct net_device *dev)
1582 {
1583         LIST_HEAD(single);
1584
1585         list_add(&dev->close_list, &single);
1586         __dev_close_many(&single);
1587         list_del(&single);
1588 }
1589
1590 void dev_close_many(struct list_head *head, bool unlink)
1591 {
1592         struct net_device *dev, *tmp;
1593
1594         /* Remove the devices that don't need to be closed */
1595         list_for_each_entry_safe(dev, tmp, head, close_list)
1596                 if (!(dev->flags & IFF_UP))
1597                         list_del_init(&dev->close_list);
1598
1599         __dev_close_many(head);
1600
1601         list_for_each_entry_safe(dev, tmp, head, close_list) {
1602                 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1603                 call_netdevice_notifiers(NETDEV_DOWN, dev);
1604                 if (unlink)
1605                         list_del_init(&dev->close_list);
1606         }
1607 }
1608 EXPORT_SYMBOL(dev_close_many);
1609
1610 /**
1611  *      dev_close - shutdown an interface.
1612  *      @dev: device to shutdown
1613  *
1614  *      This function moves an active device into down state. A
1615  *      %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1616  *      is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1617  *      chain.
1618  */
1619 void dev_close(struct net_device *dev)
1620 {
1621         if (dev->flags & IFF_UP) {
1622                 LIST_HEAD(single);
1623
1624                 list_add(&dev->close_list, &single);
1625                 dev_close_many(&single, true);
1626                 list_del(&single);
1627         }
1628 }
1629 EXPORT_SYMBOL(dev_close);
1630
1631
1632 /**
1633  *      dev_disable_lro - disable Large Receive Offload on a device
1634  *      @dev: device
1635  *
1636  *      Disable Large Receive Offload (LRO) on a net device.  Must be
1637  *      called under RTNL.  This is needed if received packets may be
1638  *      forwarded to another interface.
1639  */
1640 void dev_disable_lro(struct net_device *dev)
1641 {
1642         struct net_device *lower_dev;
1643         struct list_head *iter;
1644
1645         dev->wanted_features &= ~NETIF_F_LRO;
1646         netdev_update_features(dev);
1647
1648         if (unlikely(dev->features & NETIF_F_LRO))
1649                 netdev_WARN(dev, "failed to disable LRO!\n");
1650
1651         netdev_for_each_lower_dev(dev, lower_dev, iter)
1652                 dev_disable_lro(lower_dev);
1653 }
1654 EXPORT_SYMBOL(dev_disable_lro);
1655
1656 /**
1657  *      dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1658  *      @dev: device
1659  *
1660  *      Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1661  *      called under RTNL.  This is needed if Generic XDP is installed on
1662  *      the device.
1663  */
1664 static void dev_disable_gro_hw(struct net_device *dev)
1665 {
1666         dev->wanted_features &= ~NETIF_F_GRO_HW;
1667         netdev_update_features(dev);
1668
1669         if (unlikely(dev->features & NETIF_F_GRO_HW))
1670                 netdev_WARN(dev, "failed to disable GRO_HW!\n");
1671 }
1672
1673 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1674 {
1675 #define N(val)                                          \
1676         case NETDEV_##val:                              \
1677                 return "NETDEV_" __stringify(val);
1678         switch (cmd) {
1679         N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1680         N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1681         N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1682         N(POST_INIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN) N(CHANGEUPPER)
1683         N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
1684         N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
1685         N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1686         N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1687         N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1688         N(PRE_CHANGEADDR)
1689         }
1690 #undef N
1691         return "UNKNOWN_NETDEV_EVENT";
1692 }
1693 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1694
1695 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1696                                    struct net_device *dev)
1697 {
1698         struct netdev_notifier_info info = {
1699                 .dev = dev,
1700         };
1701
1702         return nb->notifier_call(nb, val, &info);
1703 }
1704
1705 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1706                                              struct net_device *dev)
1707 {
1708         int err;
1709
1710         err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1711         err = notifier_to_errno(err);
1712         if (err)
1713                 return err;
1714
1715         if (!(dev->flags & IFF_UP))
1716                 return 0;
1717
1718         call_netdevice_notifier(nb, NETDEV_UP, dev);
1719         return 0;
1720 }
1721
1722 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1723                                                 struct net_device *dev)
1724 {
1725         if (dev->flags & IFF_UP) {
1726                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1727                                         dev);
1728                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1729         }
1730         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1731 }
1732
1733 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1734                                                  struct net *net)
1735 {
1736         struct net_device *dev;
1737         int err;
1738
1739         for_each_netdev(net, dev) {
1740                 err = call_netdevice_register_notifiers(nb, dev);
1741                 if (err)
1742                         goto rollback;
1743         }
1744         return 0;
1745
1746 rollback:
1747         for_each_netdev_continue_reverse(net, dev)
1748                 call_netdevice_unregister_notifiers(nb, dev);
1749         return err;
1750 }
1751
1752 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1753                                                     struct net *net)
1754 {
1755         struct net_device *dev;
1756
1757         for_each_netdev(net, dev)
1758                 call_netdevice_unregister_notifiers(nb, dev);
1759 }
1760
1761 static int dev_boot_phase = 1;
1762
1763 /**
1764  * register_netdevice_notifier - register a network notifier block
1765  * @nb: notifier
1766  *
1767  * Register a notifier to be called when network device events occur.
1768  * The notifier passed is linked into the kernel structures and must
1769  * not be reused until it has been unregistered. A negative errno code
1770  * is returned on a failure.
1771  *
1772  * When registered all registration and up events are replayed
1773  * to the new notifier to allow device to have a race free
1774  * view of the network device list.
1775  */
1776
1777 int register_netdevice_notifier(struct notifier_block *nb)
1778 {
1779         struct net *net;
1780         int err;
1781
1782         /* Close race with setup_net() and cleanup_net() */
1783         down_write(&pernet_ops_rwsem);
1784         rtnl_lock();
1785         err = raw_notifier_chain_register(&netdev_chain, nb);
1786         if (err)
1787                 goto unlock;
1788         if (dev_boot_phase)
1789                 goto unlock;
1790         for_each_net(net) {
1791                 err = call_netdevice_register_net_notifiers(nb, net);
1792                 if (err)
1793                         goto rollback;
1794         }
1795
1796 unlock:
1797         rtnl_unlock();
1798         up_write(&pernet_ops_rwsem);
1799         return err;
1800
1801 rollback:
1802         for_each_net_continue_reverse(net)
1803                 call_netdevice_unregister_net_notifiers(nb, net);
1804
1805         raw_notifier_chain_unregister(&netdev_chain, nb);
1806         goto unlock;
1807 }
1808 EXPORT_SYMBOL(register_netdevice_notifier);
1809
1810 /**
1811  * unregister_netdevice_notifier - unregister a network notifier block
1812  * @nb: notifier
1813  *
1814  * Unregister a notifier previously registered by
1815  * register_netdevice_notifier(). The notifier is unlinked into the
1816  * kernel structures and may then be reused. A negative errno code
1817  * is returned on a failure.
1818  *
1819  * After unregistering unregister and down device events are synthesized
1820  * for all devices on the device list to the removed notifier to remove
1821  * the need for special case cleanup code.
1822  */
1823
1824 int unregister_netdevice_notifier(struct notifier_block *nb)
1825 {
1826         struct net *net;
1827         int err;
1828
1829         /* Close race with setup_net() and cleanup_net() */
1830         down_write(&pernet_ops_rwsem);
1831         rtnl_lock();
1832         err = raw_notifier_chain_unregister(&netdev_chain, nb);
1833         if (err)
1834                 goto unlock;
1835
1836         for_each_net(net)
1837                 call_netdevice_unregister_net_notifiers(nb, net);
1838
1839 unlock:
1840         rtnl_unlock();
1841         up_write(&pernet_ops_rwsem);
1842         return err;
1843 }
1844 EXPORT_SYMBOL(unregister_netdevice_notifier);
1845
1846 static int __register_netdevice_notifier_net(struct net *net,
1847                                              struct notifier_block *nb,
1848                                              bool ignore_call_fail)
1849 {
1850         int err;
1851
1852         err = raw_notifier_chain_register(&net->netdev_chain, nb);
1853         if (err)
1854                 return err;
1855         if (dev_boot_phase)
1856                 return 0;
1857
1858         err = call_netdevice_register_net_notifiers(nb, net);
1859         if (err && !ignore_call_fail)
1860                 goto chain_unregister;
1861
1862         return 0;
1863
1864 chain_unregister:
1865         raw_notifier_chain_unregister(&net->netdev_chain, nb);
1866         return err;
1867 }
1868
1869 static int __unregister_netdevice_notifier_net(struct net *net,
1870                                                struct notifier_block *nb)
1871 {
1872         int err;
1873
1874         err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1875         if (err)
1876                 return err;
1877
1878         call_netdevice_unregister_net_notifiers(nb, net);
1879         return 0;
1880 }
1881
1882 /**
1883  * register_netdevice_notifier_net - register a per-netns network notifier block
1884  * @net: network namespace
1885  * @nb: notifier
1886  *
1887  * Register a notifier to be called when network device events occur.
1888  * The notifier passed is linked into the kernel structures and must
1889  * not be reused until it has been unregistered. A negative errno code
1890  * is returned on a failure.
1891  *
1892  * When registered all registration and up events are replayed
1893  * to the new notifier to allow device to have a race free
1894  * view of the network device list.
1895  */
1896
1897 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1898 {
1899         int err;
1900
1901         rtnl_lock();
1902         err = __register_netdevice_notifier_net(net, nb, false);
1903         rtnl_unlock();
1904         return err;
1905 }
1906 EXPORT_SYMBOL(register_netdevice_notifier_net);
1907
1908 /**
1909  * unregister_netdevice_notifier_net - unregister a per-netns
1910  *                                     network notifier block
1911  * @net: network namespace
1912  * @nb: notifier
1913  *
1914  * Unregister a notifier previously registered by
1915  * register_netdevice_notifier(). The notifier is unlinked into the
1916  * kernel structures and may then be reused. A negative errno code
1917  * is returned on a failure.
1918  *
1919  * After unregistering unregister and down device events are synthesized
1920  * for all devices on the device list to the removed notifier to remove
1921  * the need for special case cleanup code.
1922  */
1923
1924 int unregister_netdevice_notifier_net(struct net *net,
1925                                       struct notifier_block *nb)
1926 {
1927         int err;
1928
1929         rtnl_lock();
1930         err = __unregister_netdevice_notifier_net(net, nb);
1931         rtnl_unlock();
1932         return err;
1933 }
1934 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1935
1936 int register_netdevice_notifier_dev_net(struct net_device *dev,
1937                                         struct notifier_block *nb,
1938                                         struct netdev_net_notifier *nn)
1939 {
1940         int err;
1941
1942         rtnl_lock();
1943         err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1944         if (!err) {
1945                 nn->nb = nb;
1946                 list_add(&nn->list, &dev->net_notifier_list);
1947         }
1948         rtnl_unlock();
1949         return err;
1950 }
1951 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1952
1953 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1954                                           struct notifier_block *nb,
1955                                           struct netdev_net_notifier *nn)
1956 {
1957         int err;
1958
1959         rtnl_lock();
1960         list_del(&nn->list);
1961         err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1962         rtnl_unlock();
1963         return err;
1964 }
1965 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1966
1967 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1968                                              struct net *net)
1969 {
1970         struct netdev_net_notifier *nn;
1971
1972         list_for_each_entry(nn, &dev->net_notifier_list, list) {
1973                 __unregister_netdevice_notifier_net(dev_net(dev), nn->nb);
1974                 __register_netdevice_notifier_net(net, nn->nb, true);
1975         }
1976 }
1977
1978 /**
1979  *      call_netdevice_notifiers_info - call all network notifier blocks
1980  *      @val: value passed unmodified to notifier function
1981  *      @info: notifier information data
1982  *
1983  *      Call all network notifier blocks.  Parameters and return value
1984  *      are as for raw_notifier_call_chain().
1985  */
1986
1987 static int call_netdevice_notifiers_info(unsigned long val,
1988                                          struct netdev_notifier_info *info)
1989 {
1990         struct net *net = dev_net(info->dev);
1991         int ret;
1992
1993         ASSERT_RTNL();
1994
1995         /* Run per-netns notifier block chain first, then run the global one.
1996          * Hopefully, one day, the global one is going to be removed after
1997          * all notifier block registrators get converted to be per-netns.
1998          */
1999         ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
2000         if (ret & NOTIFY_STOP_MASK)
2001                 return ret;
2002         return raw_notifier_call_chain(&netdev_chain, val, info);
2003 }
2004
2005 static int call_netdevice_notifiers_extack(unsigned long val,
2006                                            struct net_device *dev,
2007                                            struct netlink_ext_ack *extack)
2008 {
2009         struct netdev_notifier_info info = {
2010                 .dev = dev,
2011                 .extack = extack,
2012         };
2013
2014         return call_netdevice_notifiers_info(val, &info);
2015 }
2016
2017 /**
2018  *      call_netdevice_notifiers - call all network notifier blocks
2019  *      @val: value passed unmodified to notifier function
2020  *      @dev: net_device pointer passed unmodified to notifier function
2021  *
2022  *      Call all network notifier blocks.  Parameters and return value
2023  *      are as for raw_notifier_call_chain().
2024  */
2025
2026 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
2027 {
2028         return call_netdevice_notifiers_extack(val, dev, NULL);
2029 }
2030 EXPORT_SYMBOL(call_netdevice_notifiers);
2031
2032 /**
2033  *      call_netdevice_notifiers_mtu - call all network notifier blocks
2034  *      @val: value passed unmodified to notifier function
2035  *      @dev: net_device pointer passed unmodified to notifier function
2036  *      @arg: additional u32 argument passed to the notifier function
2037  *
2038  *      Call all network notifier blocks.  Parameters and return value
2039  *      are as for raw_notifier_call_chain().
2040  */
2041 static int call_netdevice_notifiers_mtu(unsigned long val,
2042                                         struct net_device *dev, u32 arg)
2043 {
2044         struct netdev_notifier_info_ext info = {
2045                 .info.dev = dev,
2046                 .ext.mtu = arg,
2047         };
2048
2049         BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2050
2051         return call_netdevice_notifiers_info(val, &info.info);
2052 }
2053
2054 #ifdef CONFIG_NET_INGRESS
2055 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2056
2057 void net_inc_ingress_queue(void)
2058 {
2059         static_branch_inc(&ingress_needed_key);
2060 }
2061 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2062
2063 void net_dec_ingress_queue(void)
2064 {
2065         static_branch_dec(&ingress_needed_key);
2066 }
2067 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2068 #endif
2069
2070 #ifdef CONFIG_NET_EGRESS
2071 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2072
2073 void net_inc_egress_queue(void)
2074 {
2075         static_branch_inc(&egress_needed_key);
2076 }
2077 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2078
2079 void net_dec_egress_queue(void)
2080 {
2081         static_branch_dec(&egress_needed_key);
2082 }
2083 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2084 #endif
2085
2086 static DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2087 #ifdef CONFIG_JUMP_LABEL
2088 static atomic_t netstamp_needed_deferred;
2089 static atomic_t netstamp_wanted;
2090 static void netstamp_clear(struct work_struct *work)
2091 {
2092         int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2093         int wanted;
2094
2095         wanted = atomic_add_return(deferred, &netstamp_wanted);
2096         if (wanted > 0)
2097                 static_branch_enable(&netstamp_needed_key);
2098         else
2099                 static_branch_disable(&netstamp_needed_key);
2100 }
2101 static DECLARE_WORK(netstamp_work, netstamp_clear);
2102 #endif
2103
2104 void net_enable_timestamp(void)
2105 {
2106 #ifdef CONFIG_JUMP_LABEL
2107         int wanted;
2108
2109         while (1) {
2110                 wanted = atomic_read(&netstamp_wanted);
2111                 if (wanted <= 0)
2112                         break;
2113                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
2114                         return;
2115         }
2116         atomic_inc(&netstamp_needed_deferred);
2117         schedule_work(&netstamp_work);
2118 #else
2119         static_branch_inc(&netstamp_needed_key);
2120 #endif
2121 }
2122 EXPORT_SYMBOL(net_enable_timestamp);
2123
2124 void net_disable_timestamp(void)
2125 {
2126 #ifdef CONFIG_JUMP_LABEL
2127         int wanted;
2128
2129         while (1) {
2130                 wanted = atomic_read(&netstamp_wanted);
2131                 if (wanted <= 1)
2132                         break;
2133                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
2134                         return;
2135         }
2136         atomic_dec(&netstamp_needed_deferred);
2137         schedule_work(&netstamp_work);
2138 #else
2139         static_branch_dec(&netstamp_needed_key);
2140 #endif
2141 }
2142 EXPORT_SYMBOL(net_disable_timestamp);
2143
2144 static inline void net_timestamp_set(struct sk_buff *skb)
2145 {
2146         skb->tstamp = 0;
2147         if (static_branch_unlikely(&netstamp_needed_key))
2148                 __net_timestamp(skb);
2149 }
2150
2151 #define net_timestamp_check(COND, SKB)                          \
2152         if (static_branch_unlikely(&netstamp_needed_key)) {     \
2153                 if ((COND) && !(SKB)->tstamp)                   \
2154                         __net_timestamp(SKB);                   \
2155         }                                                       \
2156
2157 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2158 {
2159         return __is_skb_forwardable(dev, skb, true);
2160 }
2161 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2162
2163 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2164                               bool check_mtu)
2165 {
2166         int ret = ____dev_forward_skb(dev, skb, check_mtu);
2167
2168         if (likely(!ret)) {
2169                 skb->protocol = eth_type_trans(skb, dev);
2170                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2171         }
2172
2173         return ret;
2174 }
2175
2176 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2177 {
2178         return __dev_forward_skb2(dev, skb, true);
2179 }
2180 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2181
2182 /**
2183  * dev_forward_skb - loopback an skb to another netif
2184  *
2185  * @dev: destination network device
2186  * @skb: buffer to forward
2187  *
2188  * return values:
2189  *      NET_RX_SUCCESS  (no congestion)
2190  *      NET_RX_DROP     (packet was dropped, but freed)
2191  *
2192  * dev_forward_skb can be used for injecting an skb from the
2193  * start_xmit function of one device into the receive queue
2194  * of another device.
2195  *
2196  * The receiving device may be in another namespace, so
2197  * we have to clear all information in the skb that could
2198  * impact namespace isolation.
2199  */
2200 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2201 {
2202         return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2203 }
2204 EXPORT_SYMBOL_GPL(dev_forward_skb);
2205
2206 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2207 {
2208         return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2209 }
2210
2211 static inline int deliver_skb(struct sk_buff *skb,
2212                               struct packet_type *pt_prev,
2213                               struct net_device *orig_dev)
2214 {
2215         if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2216                 return -ENOMEM;
2217         refcount_inc(&skb->users);
2218         return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2219 }
2220
2221 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2222                                           struct packet_type **pt,
2223                                           struct net_device *orig_dev,
2224                                           __be16 type,
2225                                           struct list_head *ptype_list)
2226 {
2227         struct packet_type *ptype, *pt_prev = *pt;
2228
2229         list_for_each_entry_rcu(ptype, ptype_list, list) {
2230                 if (ptype->type != type)
2231                         continue;
2232                 if (pt_prev)
2233                         deliver_skb(skb, pt_prev, orig_dev);
2234                 pt_prev = ptype;
2235         }
2236         *pt = pt_prev;
2237 }
2238
2239 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2240 {
2241         if (!ptype->af_packet_priv || !skb->sk)
2242                 return false;
2243
2244         if (ptype->id_match)
2245                 return ptype->id_match(ptype, skb->sk);
2246         else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2247                 return true;
2248
2249         return false;
2250 }
2251
2252 /**
2253  * dev_nit_active - return true if any network interface taps are in use
2254  *
2255  * @dev: network device to check for the presence of taps
2256  */
2257 bool dev_nit_active(struct net_device *dev)
2258 {
2259         return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2260 }
2261 EXPORT_SYMBOL_GPL(dev_nit_active);
2262
2263 /*
2264  *      Support routine. Sends outgoing frames to any network
2265  *      taps currently in use.
2266  */
2267
2268 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2269 {
2270         struct packet_type *ptype;
2271         struct sk_buff *skb2 = NULL;
2272         struct packet_type *pt_prev = NULL;
2273         struct list_head *ptype_list = &ptype_all;
2274
2275         rcu_read_lock();
2276 again:
2277         list_for_each_entry_rcu(ptype, ptype_list, list) {
2278                 if (ptype->ignore_outgoing)
2279                         continue;
2280
2281                 /* Never send packets back to the socket
2282                  * they originated from - MvS (miquels@drinkel.ow.org)
2283                  */
2284                 if (skb_loop_sk(ptype, skb))
2285                         continue;
2286
2287                 if (pt_prev) {
2288                         deliver_skb(skb2, pt_prev, skb->dev);
2289                         pt_prev = ptype;
2290                         continue;
2291                 }
2292
2293                 /* need to clone skb, done only once */
2294                 skb2 = skb_clone(skb, GFP_ATOMIC);
2295                 if (!skb2)
2296                         goto out_unlock;
2297
2298                 net_timestamp_set(skb2);
2299
2300                 /* skb->nh should be correctly
2301                  * set by sender, so that the second statement is
2302                  * just protection against buggy protocols.
2303                  */
2304                 skb_reset_mac_header(skb2);
2305
2306                 if (skb_network_header(skb2) < skb2->data ||
2307                     skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2308                         net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2309                                              ntohs(skb2->protocol),
2310                                              dev->name);
2311                         skb_reset_network_header(skb2);
2312                 }
2313
2314                 skb2->transport_header = skb2->network_header;
2315                 skb2->pkt_type = PACKET_OUTGOING;
2316                 pt_prev = ptype;
2317         }
2318
2319         if (ptype_list == &ptype_all) {
2320                 ptype_list = &dev->ptype_all;
2321                 goto again;
2322         }
2323 out_unlock:
2324         if (pt_prev) {
2325                 if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2326                         pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2327                 else
2328                         kfree_skb(skb2);
2329         }
2330         rcu_read_unlock();
2331 }
2332 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2333
2334 /**
2335  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2336  * @dev: Network device
2337  * @txq: number of queues available
2338  *
2339  * If real_num_tx_queues is changed the tc mappings may no longer be
2340  * valid. To resolve this verify the tc mapping remains valid and if
2341  * not NULL the mapping. With no priorities mapping to this
2342  * offset/count pair it will no longer be used. In the worst case TC0
2343  * is invalid nothing can be done so disable priority mappings. If is
2344  * expected that drivers will fix this mapping if they can before
2345  * calling netif_set_real_num_tx_queues.
2346  */
2347 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2348 {
2349         int i;
2350         struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2351
2352         /* If TC0 is invalidated disable TC mapping */
2353         if (tc->offset + tc->count > txq) {
2354                 netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2355                 dev->num_tc = 0;
2356                 return;
2357         }
2358
2359         /* Invalidated prio to tc mappings set to TC0 */
2360         for (i = 1; i < TC_BITMASK + 1; i++) {
2361                 int q = netdev_get_prio_tc_map(dev, i);
2362
2363                 tc = &dev->tc_to_txq[q];
2364                 if (tc->offset + tc->count > txq) {
2365                         netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2366                                     i, q);
2367                         netdev_set_prio_tc_map(dev, i, 0);
2368                 }
2369         }
2370 }
2371
2372 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2373 {
2374         if (dev->num_tc) {
2375                 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2376                 int i;
2377
2378                 /* walk through the TCs and see if it falls into any of them */
2379                 for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2380                         if ((txq - tc->offset) < tc->count)
2381                                 return i;
2382                 }
2383
2384                 /* didn't find it, just return -1 to indicate no match */
2385                 return -1;
2386         }
2387
2388         return 0;
2389 }
2390 EXPORT_SYMBOL(netdev_txq_to_tc);
2391
2392 #ifdef CONFIG_XPS
2393 static struct static_key xps_needed __read_mostly;
2394 static struct static_key xps_rxqs_needed __read_mostly;
2395 static DEFINE_MUTEX(xps_map_mutex);
2396 #define xmap_dereference(P)             \
2397         rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2398
2399 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2400                              struct xps_dev_maps *old_maps, int tci, u16 index)
2401 {
2402         struct xps_map *map = NULL;
2403         int pos;
2404
2405         if (dev_maps)
2406                 map = xmap_dereference(dev_maps->attr_map[tci]);
2407         if (!map)
2408                 return false;
2409
2410         for (pos = map->len; pos--;) {
2411                 if (map->queues[pos] != index)
2412                         continue;
2413
2414                 if (map->len > 1) {
2415                         map->queues[pos] = map->queues[--map->len];
2416                         break;
2417                 }
2418
2419                 if (old_maps)
2420                         RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2421                 RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2422                 kfree_rcu(map, rcu);
2423                 return false;
2424         }
2425
2426         return true;
2427 }
2428
2429 static bool remove_xps_queue_cpu(struct net_device *dev,
2430                                  struct xps_dev_maps *dev_maps,
2431                                  int cpu, u16 offset, u16 count)
2432 {
2433         int num_tc = dev_maps->num_tc;
2434         bool active = false;
2435         int tci;
2436
2437         for (tci = cpu * num_tc; num_tc--; tci++) {
2438                 int i, j;
2439
2440                 for (i = count, j = offset; i--; j++) {
2441                         if (!remove_xps_queue(dev_maps, NULL, tci, j))
2442                                 break;
2443                 }
2444
2445                 active |= i < 0;
2446         }
2447
2448         return active;
2449 }
2450
2451 static void reset_xps_maps(struct net_device *dev,
2452                            struct xps_dev_maps *dev_maps,
2453                            enum xps_map_type type)
2454 {
2455         static_key_slow_dec_cpuslocked(&xps_needed);
2456         if (type == XPS_RXQS)
2457                 static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2458
2459         RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2460
2461         kfree_rcu(dev_maps, rcu);
2462 }
2463
2464 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2465                            u16 offset, u16 count)
2466 {
2467         struct xps_dev_maps *dev_maps;
2468         bool active = false;
2469         int i, j;
2470
2471         dev_maps = xmap_dereference(dev->xps_maps[type]);
2472         if (!dev_maps)
2473                 return;
2474
2475         for (j = 0; j < dev_maps->nr_ids; j++)
2476                 active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2477         if (!active)
2478                 reset_xps_maps(dev, dev_maps, type);
2479
2480         if (type == XPS_CPUS) {
2481                 for (i = offset + (count - 1); count--; i--)
2482                         netdev_queue_numa_node_write(
2483                                 netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2484         }
2485 }
2486
2487 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2488                                    u16 count)
2489 {
2490         if (!static_key_false(&xps_needed))
2491                 return;
2492
2493         cpus_read_lock();
2494         mutex_lock(&xps_map_mutex);
2495
2496         if (static_key_false(&xps_rxqs_needed))
2497                 clean_xps_maps(dev, XPS_RXQS, offset, count);
2498
2499         clean_xps_maps(dev, XPS_CPUS, offset, count);
2500
2501         mutex_unlock(&xps_map_mutex);
2502         cpus_read_unlock();
2503 }
2504
2505 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2506 {
2507         netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2508 }
2509
2510 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2511                                       u16 index, bool is_rxqs_map)
2512 {
2513         struct xps_map *new_map;
2514         int alloc_len = XPS_MIN_MAP_ALLOC;
2515         int i, pos;
2516
2517         for (pos = 0; map && pos < map->len; pos++) {
2518                 if (map->queues[pos] != index)
2519                         continue;
2520                 return map;
2521         }
2522
2523         /* Need to add tx-queue to this CPU's/rx-queue's existing map */
2524         if (map) {
2525                 if (pos < map->alloc_len)
2526                         return map;
2527
2528                 alloc_len = map->alloc_len * 2;
2529         }
2530
2531         /* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2532          *  map
2533          */
2534         if (is_rxqs_map)
2535                 new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2536         else
2537                 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2538                                        cpu_to_node(attr_index));
2539         if (!new_map)
2540                 return NULL;
2541
2542         for (i = 0; i < pos; i++)
2543                 new_map->queues[i] = map->queues[i];
2544         new_map->alloc_len = alloc_len;
2545         new_map->len = pos;
2546
2547         return new_map;
2548 }
2549
2550 /* Copy xps maps at a given index */
2551 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2552                               struct xps_dev_maps *new_dev_maps, int index,
2553                               int tc, bool skip_tc)
2554 {
2555         int i, tci = index * dev_maps->num_tc;
2556         struct xps_map *map;
2557
2558         /* copy maps belonging to foreign traffic classes */
2559         for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2560                 if (i == tc && skip_tc)
2561                         continue;
2562
2563                 /* fill in the new device map from the old device map */
2564                 map = xmap_dereference(dev_maps->attr_map[tci]);
2565                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2566         }
2567 }
2568
2569 /* Must be called under cpus_read_lock */
2570 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2571                           u16 index, enum xps_map_type type)
2572 {
2573         struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2574         const unsigned long *online_mask = NULL;
2575         bool active = false, copy = false;
2576         int i, j, tci, numa_node_id = -2;
2577         int maps_sz, num_tc = 1, tc = 0;
2578         struct xps_map *map, *new_map;
2579         unsigned int nr_ids;
2580
2581         if (dev->num_tc) {
2582                 /* Do not allow XPS on subordinate device directly */
2583                 num_tc = dev->num_tc;
2584                 if (num_tc < 0)
2585                         return -EINVAL;
2586
2587                 /* If queue belongs to subordinate dev use its map */
2588                 dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2589
2590                 tc = netdev_txq_to_tc(dev, index);
2591                 if (tc < 0)
2592                         return -EINVAL;
2593         }
2594
2595         mutex_lock(&xps_map_mutex);
2596
2597         dev_maps = xmap_dereference(dev->xps_maps[type]);
2598         if (type == XPS_RXQS) {
2599                 maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2600                 nr_ids = dev->num_rx_queues;
2601         } else {
2602                 maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2603                 if (num_possible_cpus() > 1)
2604                         online_mask = cpumask_bits(cpu_online_mask);
2605                 nr_ids = nr_cpu_ids;
2606         }
2607
2608         if (maps_sz < L1_CACHE_BYTES)
2609                 maps_sz = L1_CACHE_BYTES;
2610
2611         /* The old dev_maps could be larger or smaller than the one we're
2612          * setting up now, as dev->num_tc or nr_ids could have been updated in
2613          * between. We could try to be smart, but let's be safe instead and only
2614          * copy foreign traffic classes if the two map sizes match.
2615          */
2616         if (dev_maps &&
2617             dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2618                 copy = true;
2619
2620         /* allocate memory for queue storage */
2621         for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2622              j < nr_ids;) {
2623                 if (!new_dev_maps) {
2624                         new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2625                         if (!new_dev_maps) {
2626                                 mutex_unlock(&xps_map_mutex);
2627                                 return -ENOMEM;
2628                         }
2629
2630                         new_dev_maps->nr_ids = nr_ids;
2631                         new_dev_maps->num_tc = num_tc;
2632                 }
2633
2634                 tci = j * num_tc + tc;
2635                 map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2636
2637                 map = expand_xps_map(map, j, index, type == XPS_RXQS);
2638                 if (!map)
2639                         goto error;
2640
2641                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2642         }
2643
2644         if (!new_dev_maps)
2645                 goto out_no_new_maps;
2646
2647         if (!dev_maps) {
2648                 /* Increment static keys at most once per type */
2649                 static_key_slow_inc_cpuslocked(&xps_needed);
2650                 if (type == XPS_RXQS)
2651                         static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2652         }
2653
2654         for (j = 0; j < nr_ids; j++) {
2655                 bool skip_tc = false;
2656
2657                 tci = j * num_tc + tc;
2658                 if (netif_attr_test_mask(j, mask, nr_ids) &&
2659                     netif_attr_test_online(j, online_mask, nr_ids)) {
2660                         /* add tx-queue to CPU/rx-queue maps */
2661                         int pos = 0;
2662
2663                         skip_tc = true;
2664
2665                         map = xmap_dereference(new_dev_maps->attr_map[tci]);
2666                         while ((pos < map->len) && (map->queues[pos] != index))
2667                                 pos++;
2668
2669                         if (pos == map->len)
2670                                 map->queues[map->len++] = index;
2671 #ifdef CONFIG_NUMA
2672                         if (type == XPS_CPUS) {
2673                                 if (numa_node_id == -2)
2674                                         numa_node_id = cpu_to_node(j);
2675                                 else if (numa_node_id != cpu_to_node(j))
2676                                         numa_node_id = -1;
2677                         }
2678 #endif
2679                 }
2680
2681                 if (copy)
2682                         xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2683                                           skip_tc);
2684         }
2685
2686         rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2687
2688         /* Cleanup old maps */
2689         if (!dev_maps)
2690                 goto out_no_old_maps;
2691
2692         for (j = 0; j < dev_maps->nr_ids; j++) {
2693                 for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2694                         map = xmap_dereference(dev_maps->attr_map[tci]);
2695                         if (!map)
2696                                 continue;
2697
2698                         if (copy) {
2699                                 new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2700                                 if (map == new_map)
2701                                         continue;
2702                         }
2703
2704                         RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2705                         kfree_rcu(map, rcu);
2706                 }
2707         }
2708
2709         old_dev_maps = dev_maps;
2710
2711 out_no_old_maps:
2712         dev_maps = new_dev_maps;
2713         active = true;
2714
2715 out_no_new_maps:
2716         if (type == XPS_CPUS)
2717                 /* update Tx queue numa node */
2718                 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2719                                              (numa_node_id >= 0) ?
2720                                              numa_node_id : NUMA_NO_NODE);
2721
2722         if (!dev_maps)
2723                 goto out_no_maps;
2724
2725         /* removes tx-queue from unused CPUs/rx-queues */
2726         for (j = 0; j < dev_maps->nr_ids; j++) {
2727                 tci = j * dev_maps->num_tc;
2728
2729                 for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2730                         if (i == tc &&
2731                             netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2732                             netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2733                                 continue;
2734
2735                         active |= remove_xps_queue(dev_maps,
2736                                                    copy ? old_dev_maps : NULL,
2737                                                    tci, index);
2738                 }
2739         }
2740
2741         if (old_dev_maps)
2742                 kfree_rcu(old_dev_maps, rcu);
2743
2744         /* free map if not active */
2745         if (!active)
2746                 reset_xps_maps(dev, dev_maps, type);
2747
2748 out_no_maps:
2749         mutex_unlock(&xps_map_mutex);
2750
2751         return 0;
2752 error:
2753         /* remove any maps that we added */
2754         for (j = 0; j < nr_ids; j++) {
2755                 for (i = num_tc, tci = j * num_tc; i--; tci++) {
2756                         new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2757                         map = copy ?
2758                               xmap_dereference(dev_maps->attr_map[tci]) :
2759                               NULL;
2760                         if (new_map && new_map != map)
2761                                 kfree(new_map);
2762                 }
2763         }
2764
2765         mutex_unlock(&xps_map_mutex);
2766
2767         kfree(new_dev_maps);
2768         return -ENOMEM;
2769 }
2770 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2771
2772 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2773                         u16 index)
2774 {
2775         int ret;
2776
2777         cpus_read_lock();
2778         ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2779         cpus_read_unlock();
2780
2781         return ret;
2782 }
2783 EXPORT_SYMBOL(netif_set_xps_queue);
2784
2785 #endif
2786 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2787 {
2788         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2789
2790         /* Unbind any subordinate channels */
2791         while (txq-- != &dev->_tx[0]) {
2792                 if (txq->sb_dev)
2793                         netdev_unbind_sb_channel(dev, txq->sb_dev);
2794         }
2795 }
2796
2797 void netdev_reset_tc(struct net_device *dev)
2798 {
2799 #ifdef CONFIG_XPS
2800         netif_reset_xps_queues_gt(dev, 0);
2801 #endif
2802         netdev_unbind_all_sb_channels(dev);
2803
2804         /* Reset TC configuration of device */
2805         dev->num_tc = 0;
2806         memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2807         memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2808 }
2809 EXPORT_SYMBOL(netdev_reset_tc);
2810
2811 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2812 {
2813         if (tc >= dev->num_tc)
2814                 return -EINVAL;
2815
2816 #ifdef CONFIG_XPS
2817         netif_reset_xps_queues(dev, offset, count);
2818 #endif
2819         dev->tc_to_txq[tc].count = count;
2820         dev->tc_to_txq[tc].offset = offset;
2821         return 0;
2822 }
2823 EXPORT_SYMBOL(netdev_set_tc_queue);
2824
2825 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2826 {
2827         if (num_tc > TC_MAX_QUEUE)
2828                 return -EINVAL;
2829
2830 #ifdef CONFIG_XPS
2831         netif_reset_xps_queues_gt(dev, 0);
2832 #endif
2833         netdev_unbind_all_sb_channels(dev);
2834
2835         dev->num_tc = num_tc;
2836         return 0;
2837 }
2838 EXPORT_SYMBOL(netdev_set_num_tc);
2839
2840 void netdev_unbind_sb_channel(struct net_device *dev,
2841                               struct net_device *sb_dev)
2842 {
2843         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2844
2845 #ifdef CONFIG_XPS
2846         netif_reset_xps_queues_gt(sb_dev, 0);
2847 #endif
2848         memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2849         memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2850
2851         while (txq-- != &dev->_tx[0]) {
2852                 if (txq->sb_dev == sb_dev)
2853                         txq->sb_dev = NULL;
2854         }
2855 }
2856 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2857
2858 int netdev_bind_sb_channel_queue(struct net_device *dev,
2859                                  struct net_device *sb_dev,
2860                                  u8 tc, u16 count, u16 offset)
2861 {
2862         /* Make certain the sb_dev and dev are already configured */
2863         if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2864                 return -EINVAL;
2865
2866         /* We cannot hand out queues we don't have */
2867         if ((offset + count) > dev->real_num_tx_queues)
2868                 return -EINVAL;
2869
2870         /* Record the mapping */
2871         sb_dev->tc_to_txq[tc].count = count;
2872         sb_dev->tc_to_txq[tc].offset = offset;
2873
2874         /* Provide a way for Tx queue to find the tc_to_txq map or
2875          * XPS map for itself.
2876          */
2877         while (count--)
2878                 netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2879
2880         return 0;
2881 }
2882 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2883
2884 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2885 {
2886         /* Do not use a multiqueue device to represent a subordinate channel */
2887         if (netif_is_multiqueue(dev))
2888                 return -ENODEV;
2889
2890         /* We allow channels 1 - 32767 to be used for subordinate channels.
2891          * Channel 0 is meant to be "native" mode and used only to represent
2892          * the main root device. We allow writing 0 to reset the device back
2893          * to normal mode after being used as a subordinate channel.
2894          */
2895         if (channel > S16_MAX)
2896                 return -EINVAL;
2897
2898         dev->num_tc = -channel;
2899
2900         return 0;
2901 }
2902 EXPORT_SYMBOL(netdev_set_sb_channel);
2903
2904 /*
2905  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2906  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2907  */
2908 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2909 {
2910         bool disabling;
2911         int rc;
2912
2913         disabling = txq < dev->real_num_tx_queues;
2914
2915         if (txq < 1 || txq > dev->num_tx_queues)
2916                 return -EINVAL;
2917
2918         if (dev->reg_state == NETREG_REGISTERED ||
2919             dev->reg_state == NETREG_UNREGISTERING) {
2920                 ASSERT_RTNL();
2921
2922                 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2923                                                   txq);
2924                 if (rc)
2925                         return rc;
2926
2927                 if (dev->num_tc)
2928                         netif_setup_tc(dev, txq);
2929
2930                 dev_qdisc_change_real_num_tx(dev, txq);
2931
2932                 dev->real_num_tx_queues = txq;
2933
2934                 if (disabling) {
2935                         synchronize_net();
2936                         qdisc_reset_all_tx_gt(dev, txq);
2937 #ifdef CONFIG_XPS
2938                         netif_reset_xps_queues_gt(dev, txq);
2939 #endif
2940                 }
2941         } else {
2942                 dev->real_num_tx_queues = txq;
2943         }
2944
2945         return 0;
2946 }
2947 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2948
2949 #ifdef CONFIG_SYSFS
2950 /**
2951  *      netif_set_real_num_rx_queues - set actual number of RX queues used
2952  *      @dev: Network device
2953  *      @rxq: Actual number of RX queues
2954  *
2955  *      This must be called either with the rtnl_lock held or before
2956  *      registration of the net device.  Returns 0 on success, or a
2957  *      negative error code.  If called before registration, it always
2958  *      succeeds.
2959  */
2960 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2961 {
2962         int rc;
2963
2964         if (rxq < 1 || rxq > dev->num_rx_queues)
2965                 return -EINVAL;
2966
2967         if (dev->reg_state == NETREG_REGISTERED) {
2968                 ASSERT_RTNL();
2969
2970                 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2971                                                   rxq);
2972                 if (rc)
2973                         return rc;
2974         }
2975
2976         dev->real_num_rx_queues = rxq;
2977         return 0;
2978 }
2979 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2980 #endif
2981
2982 /**
2983  *      netif_set_real_num_queues - set actual number of RX and TX queues used
2984  *      @dev: Network device
2985  *      @txq: Actual number of TX queues
2986  *      @rxq: Actual number of RX queues
2987  *
2988  *      Set the real number of both TX and RX queues.
2989  *      Does nothing if the number of queues is already correct.
2990  */
2991 int netif_set_real_num_queues(struct net_device *dev,
2992                               unsigned int txq, unsigned int rxq)
2993 {
2994         unsigned int old_rxq = dev->real_num_rx_queues;
2995         int err;
2996
2997         if (txq < 1 || txq > dev->num_tx_queues ||
2998             rxq < 1 || rxq > dev->num_rx_queues)
2999                 return -EINVAL;
3000
3001         /* Start from increases, so the error path only does decreases -
3002          * decreases can't fail.
3003          */
3004         if (rxq > dev->real_num_rx_queues) {
3005                 err = netif_set_real_num_rx_queues(dev, rxq);
3006                 if (err)
3007                         return err;
3008         }
3009         if (txq > dev->real_num_tx_queues) {
3010                 err = netif_set_real_num_tx_queues(dev, txq);
3011                 if (err)
3012                         goto undo_rx;
3013         }
3014         if (rxq < dev->real_num_rx_queues)
3015                 WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
3016         if (txq < dev->real_num_tx_queues)
3017                 WARN_ON(netif_set_real_num_tx_queues(dev, txq));
3018
3019         return 0;
3020 undo_rx:
3021         WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
3022         return err;
3023 }
3024 EXPORT_SYMBOL(netif_set_real_num_queues);
3025
3026 /**
3027  * netif_get_num_default_rss_queues - default number of RSS queues
3028  *
3029  * This routine should set an upper limit on the number of RSS queues
3030  * used by default by multiqueue devices.
3031  */
3032 int netif_get_num_default_rss_queues(void)
3033 {
3034         return is_kdump_kernel() ?
3035                 1 : min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
3036 }
3037 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3038
3039 static void __netif_reschedule(struct Qdisc *q)
3040 {
3041         struct softnet_data *sd;
3042         unsigned long flags;
3043
3044         local_irq_save(flags);
3045         sd = this_cpu_ptr(&softnet_data);
3046         q->next_sched = NULL;
3047         *sd->output_queue_tailp = q;
3048         sd->output_queue_tailp = &q->next_sched;
3049         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3050         local_irq_restore(flags);
3051 }
3052
3053 void __netif_schedule(struct Qdisc *q)
3054 {
3055         if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3056                 __netif_reschedule(q);
3057 }
3058 EXPORT_SYMBOL(__netif_schedule);
3059
3060 struct dev_kfree_skb_cb {
3061         enum skb_free_reason reason;
3062 };
3063
3064 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3065 {
3066         return (struct dev_kfree_skb_cb *)skb->cb;
3067 }
3068
3069 void netif_schedule_queue(struct netdev_queue *txq)
3070 {
3071         rcu_read_lock();
3072         if (!netif_xmit_stopped(txq)) {
3073                 struct Qdisc *q = rcu_dereference(txq->qdisc);
3074
3075                 __netif_schedule(q);
3076         }
3077         rcu_read_unlock();
3078 }
3079 EXPORT_SYMBOL(netif_schedule_queue);
3080
3081 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3082 {
3083         if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3084                 struct Qdisc *q;
3085
3086                 rcu_read_lock();
3087                 q = rcu_dereference(dev_queue->qdisc);
3088                 __netif_schedule(q);
3089                 rcu_read_unlock();
3090         }
3091 }
3092 EXPORT_SYMBOL(netif_tx_wake_queue);
3093
3094 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
3095 {
3096         unsigned long flags;
3097
3098         if (unlikely(!skb))
3099                 return;
3100
3101         if (likely(refcount_read(&skb->users) == 1)) {
3102                 smp_rmb();
3103                 refcount_set(&skb->users, 0);
3104         } else if (likely(!refcount_dec_and_test(&skb->users))) {
3105                 return;
3106         }
3107         get_kfree_skb_cb(skb)->reason = reason;
3108         local_irq_save(flags);
3109         skb->next = __this_cpu_read(softnet_data.completion_queue);
3110         __this_cpu_write(softnet_data.completion_queue, skb);
3111         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3112         local_irq_restore(flags);
3113 }
3114 EXPORT_SYMBOL(__dev_kfree_skb_irq);
3115
3116 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
3117 {
3118         if (in_hardirq() || irqs_disabled())
3119                 __dev_kfree_skb_irq(skb, reason);
3120         else
3121                 dev_kfree_skb(skb);
3122 }
3123 EXPORT_SYMBOL(__dev_kfree_skb_any);
3124
3125
3126 /**
3127  * netif_device_detach - mark device as removed
3128  * @dev: network device
3129  *
3130  * Mark device as removed from system and therefore no longer available.
3131  */
3132 void netif_device_detach(struct net_device *dev)
3133 {
3134         if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3135             netif_running(dev)) {
3136                 netif_tx_stop_all_queues(dev);
3137         }
3138 }
3139 EXPORT_SYMBOL(netif_device_detach);
3140
3141 /**
3142  * netif_device_attach - mark device as attached
3143  * @dev: network device
3144  *
3145  * Mark device as attached from system and restart if needed.
3146  */
3147 void netif_device_attach(struct net_device *dev)
3148 {
3149         if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3150             netif_running(dev)) {
3151                 netif_tx_wake_all_queues(dev);
3152                 __netdev_watchdog_up(dev);
3153         }
3154 }
3155 EXPORT_SYMBOL(netif_device_attach);
3156
3157 /*
3158  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3159  * to be used as a distribution range.
3160  */
3161 static u16 skb_tx_hash(const struct net_device *dev,
3162                        const struct net_device *sb_dev,
3163                        struct sk_buff *skb)
3164 {
3165         u32 hash;
3166         u16 qoffset = 0;
3167         u16 qcount = dev->real_num_tx_queues;
3168
3169         if (dev->num_tc) {
3170                 u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3171
3172                 qoffset = sb_dev->tc_to_txq[tc].offset;
3173                 qcount = sb_dev->tc_to_txq[tc].count;
3174                 if (unlikely(!qcount)) {
3175                         net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3176                                              sb_dev->name, qoffset, tc);
3177                         qoffset = 0;
3178                         qcount = dev->real_num_tx_queues;
3179                 }
3180         }
3181
3182         if (skb_rx_queue_recorded(skb)) {
3183                 hash = skb_get_rx_queue(skb);
3184                 if (hash >= qoffset)
3185                         hash -= qoffset;
3186                 while (unlikely(hash >= qcount))
3187                         hash -= qcount;
3188                 return hash + qoffset;
3189         }
3190
3191         return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3192 }
3193
3194 static void skb_warn_bad_offload(const struct sk_buff *skb)
3195 {
3196         static const netdev_features_t null_features;
3197         struct net_device *dev = skb->dev;
3198         const char *name = "";
3199
3200         if (!net_ratelimit())
3201                 return;
3202
3203         if (dev) {
3204                 if (dev->dev.parent)
3205                         name = dev_driver_string(dev->dev.parent);
3206                 else
3207                         name = netdev_name(dev);
3208         }
3209         skb_dump(KERN_WARNING, skb, false);
3210         WARN(1, "%s: caps=(%pNF, %pNF)\n",
3211              name, dev ? &dev->features : &null_features,
3212              skb->sk ? &skb->sk->sk_route_caps : &null_features);
3213 }
3214
3215 /*
3216  * Invalidate hardware checksum when packet is to be mangled, and
3217  * complete checksum manually on outgoing path.
3218  */
3219 int skb_checksum_help(struct sk_buff *skb)
3220 {
3221         __wsum csum;
3222         int ret = 0, offset;
3223
3224         if (skb->ip_summed == CHECKSUM_COMPLETE)
3225                 goto out_set_summed;
3226
3227         if (unlikely(skb_is_gso(skb))) {
3228                 skb_warn_bad_offload(skb);
3229                 return -EINVAL;
3230         }
3231
3232         /* Before computing a checksum, we should make sure no frag could
3233          * be modified by an external entity : checksum could be wrong.
3234          */
3235         if (skb_has_shared_frag(skb)) {
3236                 ret = __skb_linearize(skb);
3237                 if (ret)
3238                         goto out;
3239         }
3240
3241         offset = skb_checksum_start_offset(skb);
3242         BUG_ON(offset >= skb_headlen(skb));
3243         csum = skb_checksum(skb, offset, skb->len - offset, 0);
3244
3245         offset += skb->csum_offset;
3246         BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
3247
3248         ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3249         if (ret)
3250                 goto out;
3251
3252         *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3253 out_set_summed:
3254         skb->ip_summed = CHECKSUM_NONE;
3255 out:
3256         return ret;
3257 }
3258 EXPORT_SYMBOL(skb_checksum_help);
3259
3260 int skb_crc32c_csum_help(struct sk_buff *skb)
3261 {
3262         __le32 crc32c_csum;
3263         int ret = 0, offset, start;
3264
3265         if (skb->ip_summed != CHECKSUM_PARTIAL)
3266                 goto out;
3267
3268         if (unlikely(skb_is_gso(skb)))
3269                 goto out;
3270
3271         /* Before computing a checksum, we should make sure no frag could
3272          * be modified by an external entity : checksum could be wrong.
3273          */
3274         if (unlikely(skb_has_shared_frag(skb))) {
3275                 ret = __skb_linearize(skb);
3276                 if (ret)
3277                         goto out;
3278         }
3279         start = skb_checksum_start_offset(skb);
3280         offset = start + offsetof(struct sctphdr, checksum);
3281         if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3282                 ret = -EINVAL;
3283                 goto out;
3284         }
3285
3286         ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3287         if (ret)
3288                 goto out;
3289
3290         crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3291                                                   skb->len - start, ~(__u32)0,
3292                                                   crc32c_csum_stub));
3293         *(__le32 *)(skb->data + offset) = crc32c_csum;
3294         skb->ip_summed = CHECKSUM_NONE;
3295         skb->csum_not_inet = 0;
3296 out:
3297         return ret;
3298 }
3299
3300 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3301 {
3302         __be16 type = skb->protocol;
3303
3304         /* Tunnel gso handlers can set protocol to ethernet. */
3305         if (type == htons(ETH_P_TEB)) {
3306                 struct ethhdr *eth;
3307
3308                 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3309                         return 0;
3310
3311                 eth = (struct ethhdr *)skb->data;
3312                 type = eth->h_proto;
3313         }
3314
3315         return __vlan_get_protocol(skb, type, depth);
3316 }
3317
3318 /**
3319  *      skb_mac_gso_segment - mac layer segmentation handler.
3320  *      @skb: buffer to segment
3321  *      @features: features for the output path (see dev->features)
3322  */
3323 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
3324                                     netdev_features_t features)
3325 {
3326         struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
3327         struct packet_offload *ptype;
3328         int vlan_depth = skb->mac_len;
3329         __be16 type = skb_network_protocol(skb, &vlan_depth);
3330
3331         if (unlikely(!type))
3332                 return ERR_PTR(-EINVAL);
3333
3334         __skb_pull(skb, vlan_depth);
3335
3336         rcu_read_lock();
3337         list_for_each_entry_rcu(ptype, &offload_base, list) {
3338                 if (ptype->type == type && ptype->callbacks.gso_segment) {
3339                         segs = ptype->callbacks.gso_segment(skb, features);
3340                         break;
3341                 }
3342         }
3343         rcu_read_unlock();
3344
3345         __skb_push(skb, skb->data - skb_mac_header(skb));
3346
3347         return segs;
3348 }
3349 EXPORT_SYMBOL(skb_mac_gso_segment);
3350
3351
3352 /* openvswitch calls this on rx path, so we need a different check.
3353  */
3354 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3355 {
3356         if (tx_path)
3357                 return skb->ip_summed != CHECKSUM_PARTIAL &&
3358                        skb->ip_summed != CHECKSUM_UNNECESSARY;
3359
3360         return skb->ip_summed == CHECKSUM_NONE;
3361 }
3362
3363 /**
3364  *      __skb_gso_segment - Perform segmentation on skb.
3365  *      @skb: buffer to segment
3366  *      @features: features for the output path (see dev->features)
3367  *      @tx_path: whether it is called in TX path
3368  *
3369  *      This function segments the given skb and returns a list of segments.
3370  *
3371  *      It may return NULL if the skb requires no segmentation.  This is
3372  *      only possible when GSO is used for verifying header integrity.
3373  *
3374  *      Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3375  */
3376 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3377                                   netdev_features_t features, bool tx_path)
3378 {
3379         struct sk_buff *segs;
3380
3381         if (unlikely(skb_needs_check(skb, tx_path))) {
3382                 int err;
3383
3384                 /* We're going to init ->check field in TCP or UDP header */
3385                 err = skb_cow_head(skb, 0);
3386                 if (err < 0)
3387                         return ERR_PTR(err);
3388         }
3389
3390         /* Only report GSO partial support if it will enable us to
3391          * support segmentation on this frame without needing additional
3392          * work.
3393          */
3394         if (features & NETIF_F_GSO_PARTIAL) {
3395                 netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3396                 struct net_device *dev = skb->dev;
3397
3398                 partial_features |= dev->features & dev->gso_partial_features;
3399                 if (!skb_gso_ok(skb, features | partial_features))
3400                         features &= ~NETIF_F_GSO_PARTIAL;
3401         }
3402
3403         BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3404                      sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3405
3406         SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3407         SKB_GSO_CB(skb)->encap_level = 0;
3408
3409         skb_reset_mac_header(skb);
3410         skb_reset_mac_len(skb);
3411
3412         segs = skb_mac_gso_segment(skb, features);
3413
3414         if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3415                 skb_warn_bad_offload(skb);
3416
3417         return segs;
3418 }
3419 EXPORT_SYMBOL(__skb_gso_segment);
3420
3421 /* Take action when hardware reception checksum errors are detected. */
3422 #ifdef CONFIG_BUG
3423 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3424 {
3425         netdev_err(dev, "hw csum failure\n");
3426         skb_dump(KERN_ERR, skb, true);
3427         dump_stack();
3428 }
3429
3430 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3431 {
3432         DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3433 }
3434 EXPORT_SYMBOL(netdev_rx_csum_fault);
3435 #endif
3436
3437 /* XXX: check that highmem exists at all on the given machine. */
3438 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3439 {
3440 #ifdef CONFIG_HIGHMEM
3441         int i;
3442
3443         if (!(dev->features & NETIF_F_HIGHDMA)) {
3444                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3445                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3446
3447                         if (PageHighMem(skb_frag_page(frag)))
3448                                 return 1;
3449                 }
3450         }
3451 #endif
3452         return 0;
3453 }
3454
3455 /* If MPLS offload request, verify we are testing hardware MPLS features
3456  * instead of standard features for the netdev.
3457  */
3458 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3459 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3460                                            netdev_features_t features,
3461                                            __be16 type)
3462 {
3463         if (eth_p_mpls(type))
3464                 features &= skb->dev->mpls_features;
3465
3466         return features;
3467 }
3468 #else
3469 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3470                                            netdev_features_t features,
3471                                            __be16 type)
3472 {
3473         return features;
3474 }
3475 #endif
3476
3477 static netdev_features_t harmonize_features(struct sk_buff *skb,
3478         netdev_features_t features)
3479 {
3480         __be16 type;
3481
3482         type = skb_network_protocol(skb, NULL);
3483         features = net_mpls_features(skb, features, type);
3484
3485         if (skb->ip_summed != CHECKSUM_NONE &&
3486             !can_checksum_protocol(features, type)) {
3487                 features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3488         }
3489         if (illegal_highdma(skb->dev, skb))
3490                 features &= ~NETIF_F_SG;
3491
3492         return features;
3493 }
3494
3495 netdev_features_t passthru_features_check(struct sk_buff *skb,
3496                                           struct net_device *dev,
3497                                           netdev_features_t features)
3498 {
3499         return features;
3500 }
3501 EXPORT_SYMBOL(passthru_features_check);
3502
3503 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3504                                              struct net_device *dev,
3505                                              netdev_features_t features)
3506 {
3507         return vlan_features_check(skb, features);
3508 }
3509
3510 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3511                                             struct net_device *dev,
3512                                             netdev_features_t features)
3513 {
3514         u16 gso_segs = skb_shinfo(skb)->gso_segs;
3515
3516         if (gso_segs > dev->gso_max_segs)
3517                 return features & ~NETIF_F_GSO_MASK;
3518
3519         if (!skb_shinfo(skb)->gso_type) {
3520                 skb_warn_bad_offload(skb);
3521                 return features & ~NETIF_F_GSO_MASK;
3522         }
3523
3524         /* Support for GSO partial features requires software
3525          * intervention before we can actually process the packets
3526          * so we need to strip support for any partial features now
3527          * and we can pull them back in after we have partially
3528          * segmented the frame.
3529          */
3530         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3531                 features &= ~dev->gso_partial_features;
3532
3533         /* Make sure to clear the IPv4 ID mangling feature if the
3534          * IPv4 header has the potential to be fragmented.
3535          */
3536         if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3537                 struct iphdr *iph = skb->encapsulation ?
3538                                     inner_ip_hdr(skb) : ip_hdr(skb);
3539
3540                 if (!(iph->frag_off & htons(IP_DF)))
3541                         features &= ~NETIF_F_TSO_MANGLEID;
3542         }
3543
3544         return features;
3545 }
3546
3547 netdev_features_t netif_skb_features(struct sk_buff *skb)
3548 {
3549         struct net_device *dev = skb->dev;
3550         netdev_features_t features = dev->features;
3551
3552         if (skb_is_gso(skb))
3553                 features = gso_features_check(skb, dev, features);
3554
3555         /* If encapsulation offload request, verify we are testing
3556          * hardware encapsulation features instead of standard
3557          * features for the netdev
3558          */
3559         if (skb->encapsulation)
3560                 features &= dev->hw_enc_features;
3561
3562         if (skb_vlan_tagged(skb))
3563                 features = netdev_intersect_features(features,
3564                                                      dev->vlan_features |
3565                                                      NETIF_F_HW_VLAN_CTAG_TX |
3566                                                      NETIF_F_HW_VLAN_STAG_TX);
3567
3568         if (dev->netdev_ops->ndo_features_check)
3569                 features &= dev->netdev_ops->ndo_features_check(skb, dev,
3570                                                                 features);
3571         else
3572                 features &= dflt_features_check(skb, dev, features);
3573
3574         return harmonize_features(skb, features);
3575 }
3576 EXPORT_SYMBOL(netif_skb_features);
3577
3578 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3579                     struct netdev_queue *txq, bool more)
3580 {
3581         unsigned int len;
3582         int rc;
3583
3584         if (dev_nit_active(dev))
3585                 dev_queue_xmit_nit(skb, dev);
3586
3587         len = skb->len;
3588         PRANDOM_ADD_NOISE(skb, dev, txq, len + jiffies);
3589         trace_net_dev_start_xmit(skb, dev);
3590         rc = netdev_start_xmit(skb, dev, txq, more);
3591         trace_net_dev_xmit(skb, rc, dev, len);
3592
3593         return rc;
3594 }
3595
3596 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3597                                     struct netdev_queue *txq, int *ret)
3598 {
3599         struct sk_buff *skb = first;
3600         int rc = NETDEV_TX_OK;
3601
3602         while (skb) {
3603                 struct sk_buff *next = skb->next;
3604
3605                 skb_mark_not_on_list(skb);
3606                 rc = xmit_one(skb, dev, txq, next != NULL);
3607                 if (unlikely(!dev_xmit_complete(rc))) {
3608                         skb->next = next;
3609                         goto out;
3610                 }
3611
3612                 skb = next;
3613                 if (netif_tx_queue_stopped(txq) && skb) {
3614                         rc = NETDEV_TX_BUSY;
3615                         break;
3616                 }
3617         }
3618
3619 out:
3620         *ret = rc;
3621         return skb;
3622 }
3623
3624 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3625                                           netdev_features_t features)
3626 {
3627         if (skb_vlan_tag_present(skb) &&
3628             !vlan_hw_offload_capable(features, skb->vlan_proto))
3629                 skb = __vlan_hwaccel_push_inside(skb);
3630         return skb;
3631 }
3632
3633 int skb_csum_hwoffload_help(struct sk_buff *skb,
3634                             const netdev_features_t features)
3635 {
3636         if (unlikely(skb_csum_is_sctp(skb)))
3637                 return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3638                         skb_crc32c_csum_help(skb);
3639
3640         if (features & NETIF_F_HW_CSUM)
3641                 return 0;
3642
3643         if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3644                 switch (skb->csum_offset) {
3645                 case offsetof(struct tcphdr, check):
3646                 case offsetof(struct udphdr, check):
3647                         return 0;
3648                 }
3649         }
3650
3651         return skb_checksum_help(skb);
3652 }
3653 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3654
3655 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3656 {
3657         netdev_features_t features;
3658
3659         features = netif_skb_features(skb);
3660         skb = validate_xmit_vlan(skb, features);
3661         if (unlikely(!skb))
3662                 goto out_null;
3663
3664         skb = sk_validate_xmit_skb(skb, dev);
3665         if (unlikely(!skb))
3666                 goto out_null;
3667
3668         if (netif_needs_gso(skb, features)) {
3669                 struct sk_buff *segs;
3670
3671                 segs = skb_gso_segment(skb, features);
3672                 if (IS_ERR(segs)) {
3673                         goto out_kfree_skb;
3674                 } else if (segs) {
3675                         consume_skb(skb);
3676                         skb = segs;
3677                 }
3678         } else {
3679                 if (skb_needs_linearize(skb, features) &&
3680                     __skb_linearize(skb))
3681                         goto out_kfree_skb;
3682
3683                 /* If packet is not checksummed and device does not
3684                  * support checksumming for this protocol, complete
3685                  * checksumming here.
3686                  */
3687                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3688                         if (skb->encapsulation)
3689                                 skb_set_inner_transport_header(skb,
3690                                                                skb_checksum_start_offset(skb));
3691                         else
3692                                 skb_set_transport_header(skb,
3693                                                          skb_checksum_start_offset(skb));
3694                         if (skb_csum_hwoffload_help(skb, features))
3695                                 goto out_kfree_skb;
3696                 }
3697         }
3698
3699         skb = validate_xmit_xfrm(skb, features, again);
3700
3701         return skb;
3702
3703 out_kfree_skb:
3704         kfree_skb(skb);
3705 out_null:
3706         atomic_long_inc(&dev->tx_dropped);
3707         return NULL;
3708 }
3709
3710 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3711 {
3712         struct sk_buff *next, *head = NULL, *tail;
3713
3714         for (; skb != NULL; skb = next) {
3715                 next = skb->next;
3716                 skb_mark_not_on_list(skb);
3717
3718                 /* in case skb wont be segmented, point to itself */
3719                 skb->prev = skb;
3720
3721                 skb = validate_xmit_skb(skb, dev, again);
3722                 if (!skb)
3723                         continue;
3724
3725                 if (!head)
3726                         head = skb;
3727                 else
3728                         tail->next = skb;
3729                 /* If skb was segmented, skb->prev points to
3730                  * the last segment. If not, it still contains skb.
3731                  */
3732                 tail = skb->prev;
3733         }
3734         return head;
3735 }
3736 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3737
3738 static void qdisc_pkt_len_init(struct sk_buff *skb)
3739 {
3740         const struct skb_shared_info *shinfo = skb_shinfo(skb);
3741
3742         qdisc_skb_cb(skb)->pkt_len = skb->len;
3743
3744         /* To get more precise estimation of bytes sent on wire,
3745          * we add to pkt_len the headers size of all segments
3746          */
3747         if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3748                 unsigned int hdr_len;
3749                 u16 gso_segs = shinfo->gso_segs;
3750
3751                 /* mac layer + network layer */
3752                 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
3753
3754                 /* + transport layer */
3755                 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3756                         const struct tcphdr *th;
3757                         struct tcphdr _tcphdr;
3758
3759                         th = skb_header_pointer(skb, skb_transport_offset(skb),
3760                                                 sizeof(_tcphdr), &_tcphdr);
3761                         if (likely(th))
3762                                 hdr_len += __tcp_hdrlen(th);
3763                 } else {
3764                         struct udphdr _udphdr;
3765
3766                         if (skb_header_pointer(skb, skb_transport_offset(skb),
3767                                                sizeof(_udphdr), &_udphdr))
3768                                 hdr_len += sizeof(struct udphdr);
3769                 }
3770
3771                 if (shinfo->gso_type & SKB_GSO_DODGY)
3772                         gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3773                                                 shinfo->gso_size);
3774
3775                 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3776         }
3777 }
3778
3779 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3780                              struct sk_buff **to_free,
3781                              struct netdev_queue *txq)
3782 {
3783         int rc;
3784
3785         rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3786         if (rc == NET_XMIT_SUCCESS)
3787                 trace_qdisc_enqueue(q, txq, skb);
3788         return rc;
3789 }
3790
3791 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3792                                  struct net_device *dev,
3793                                  struct netdev_queue *txq)
3794 {
3795         spinlock_t *root_lock = qdisc_lock(q);
3796         struct sk_buff *to_free = NULL;
3797         bool contended;
3798         int rc;
3799
3800         qdisc_calculate_pkt_len(skb, q);
3801
3802         if (q->flags & TCQ_F_NOLOCK) {
3803                 if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3804                     qdisc_run_begin(q)) {
3805                         /* Retest nolock_qdisc_is_empty() within the protection
3806                          * of q->seqlock to protect from racing with requeuing.
3807                          */
3808                         if (unlikely(!nolock_qdisc_is_empty(q))) {
3809                                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3810                                 __qdisc_run(q);
3811                                 qdisc_run_end(q);
3812
3813                                 goto no_lock_out;
3814                         }
3815
3816                         qdisc_bstats_cpu_update(q, skb);
3817                         if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3818                             !nolock_qdisc_is_empty(q))
3819                                 __qdisc_run(q);
3820
3821                         qdisc_run_end(q);
3822                         return NET_XMIT_SUCCESS;
3823                 }
3824
3825                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3826                 qdisc_run(q);
3827
3828 no_lock_out:
3829                 if (unlikely(to_free))
3830                         kfree_skb_list(to_free);
3831                 return rc;
3832         }
3833
3834         /*
3835          * Heuristic to force contended enqueues to serialize on a
3836          * separate lock before trying to get qdisc main lock.
3837          * This permits qdisc->running owner to get the lock more
3838          * often and dequeue packets faster.
3839          */
3840         contended = qdisc_is_running(q);
3841         if (unlikely(contended))
3842                 spin_lock(&q->busylock);
3843
3844         spin_lock(root_lock);
3845         if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3846                 __qdisc_drop(skb, &to_free);
3847                 rc = NET_XMIT_DROP;
3848         } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3849                    qdisc_run_begin(q)) {
3850                 /*
3851                  * This is a work-conserving queue; there are no old skbs
3852                  * waiting to be sent out; and the qdisc is not running -
3853                  * xmit the skb directly.
3854                  */
3855
3856                 qdisc_bstats_update(q, skb);
3857
3858                 if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3859                         if (unlikely(contended)) {
3860                                 spin_unlock(&q->busylock);
3861                                 contended = false;
3862                         }
3863                         __qdisc_run(q);
3864                 }
3865
3866                 qdisc_run_end(q);
3867                 rc = NET_XMIT_SUCCESS;
3868         } else {
3869                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3870                 if (qdisc_run_begin(q)) {
3871                         if (unlikely(contended)) {
3872                                 spin_unlock(&q->busylock);
3873                                 contended = false;
3874                         }
3875                         __qdisc_run(q);
3876                         qdisc_run_end(q);
3877                 }
3878         }
3879         spin_unlock(root_lock);
3880         if (unlikely(to_free))
3881                 kfree_skb_list(to_free);
3882         if (unlikely(contended))
3883                 spin_unlock(&q->busylock);
3884         return rc;
3885 }
3886
3887 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3888 static void skb_update_prio(struct sk_buff *skb)
3889 {
3890         const struct netprio_map *map;
3891         const struct sock *sk;
3892         unsigned int prioidx;
3893
3894         if (skb->priority)
3895                 return;
3896         map = rcu_dereference_bh(skb->dev->priomap);
3897         if (!map)
3898                 return;
3899         sk = skb_to_full_sk(skb);
3900         if (!sk)
3901                 return;
3902
3903         prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3904
3905         if (prioidx < map->priomap_len)
3906                 skb->priority = map->priomap[prioidx];
3907 }
3908 #else
3909 #define skb_update_prio(skb)
3910 #endif
3911
3912 /**
3913  *      dev_loopback_xmit - loop back @skb
3914  *      @net: network namespace this loopback is happening in
3915  *      @sk:  sk needed to be a netfilter okfn
3916  *      @skb: buffer to transmit
3917  */
3918 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3919 {
3920         skb_reset_mac_header(skb);
3921         __skb_pull(skb, skb_network_offset(skb));
3922         skb->pkt_type = PACKET_LOOPBACK;
3923         if (skb->ip_summed == CHECKSUM_NONE)
3924                 skb->ip_summed = CHECKSUM_UNNECESSARY;
3925         WARN_ON(!skb_dst(skb));
3926         skb_dst_force(skb);
3927         netif_rx_ni(skb);
3928         return 0;
3929 }
3930 EXPORT_SYMBOL(dev_loopback_xmit);
3931
3932 #ifdef CONFIG_NET_EGRESS
3933 static struct sk_buff *
3934 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3935 {
3936 #ifdef CONFIG_NET_CLS_ACT
3937         struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3938         struct tcf_result cl_res;
3939
3940         if (!miniq)
3941                 return skb;
3942
3943         /* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3944         qdisc_skb_cb(skb)->mru = 0;
3945         qdisc_skb_cb(skb)->post_ct = false;
3946         mini_qdisc_bstats_cpu_update(miniq, skb);
3947
3948         switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3949         case TC_ACT_OK:
3950         case TC_ACT_RECLASSIFY:
3951                 skb->tc_index = TC_H_MIN(cl_res.classid);
3952                 break;
3953         case TC_ACT_SHOT:
3954                 mini_qdisc_qstats_cpu_drop(miniq);
3955                 *ret = NET_XMIT_DROP;
3956                 kfree_skb(skb);
3957                 return NULL;
3958         case TC_ACT_STOLEN:
3959         case TC_ACT_QUEUED:
3960         case TC_ACT_TRAP:
3961                 *ret = NET_XMIT_SUCCESS;
3962                 consume_skb(skb);
3963                 return NULL;
3964         case TC_ACT_REDIRECT:
3965                 /* No need to push/pop skb's mac_header here on egress! */
3966                 skb_do_redirect(skb);
3967                 *ret = NET_XMIT_SUCCESS;
3968                 return NULL;
3969         default:
3970                 break;
3971         }
3972 #endif /* CONFIG_NET_CLS_ACT */
3973
3974         return skb;
3975 }
3976 #endif /* CONFIG_NET_EGRESS */
3977
3978 #ifdef CONFIG_XPS
3979 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
3980                                struct xps_dev_maps *dev_maps, unsigned int tci)
3981 {
3982         int tc = netdev_get_prio_tc_map(dev, skb->priority);
3983         struct xps_map *map;
3984         int queue_index = -1;
3985
3986         if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
3987                 return queue_index;
3988
3989         tci *= dev_maps->num_tc;
3990         tci += tc;
3991
3992         map = rcu_dereference(dev_maps->attr_map[tci]);
3993         if (map) {
3994                 if (map->len == 1)
3995                         queue_index = map->queues[0];
3996                 else
3997                         queue_index = map->queues[reciprocal_scale(
3998                                                 skb_get_hash(skb), map->len)];
3999                 if (unlikely(queue_index >= dev->real_num_tx_queues))
4000                         queue_index = -1;
4001         }
4002         return queue_index;
4003 }
4004 #endif
4005
4006 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4007                          struct sk_buff *skb)
4008 {
4009 #ifdef CONFIG_XPS
4010         struct xps_dev_maps *dev_maps;
4011         struct sock *sk = skb->sk;
4012         int queue_index = -1;
4013
4014         if (!static_key_false(&xps_needed))
4015                 return -1;
4016
4017         rcu_read_lock();
4018         if (!static_key_false(&xps_rxqs_needed))
4019                 goto get_cpus_map;
4020
4021         dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4022         if (dev_maps) {
4023                 int tci = sk_rx_queue_get(sk);
4024
4025                 if (tci >= 0)
4026                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4027                                                           tci);
4028         }
4029
4030 get_cpus_map:
4031         if (queue_index < 0) {
4032                 dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4033                 if (dev_maps) {
4034                         unsigned int tci = skb->sender_cpu - 1;
4035
4036                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4037                                                           tci);
4038                 }
4039         }
4040         rcu_read_unlock();
4041
4042         return queue_index;
4043 #else
4044         return -1;
4045 #endif
4046 }
4047
4048 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4049                      struct net_device *sb_dev)
4050 {
4051         return 0;
4052 }
4053 EXPORT_SYMBOL(dev_pick_tx_zero);
4054
4055 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4056                        struct net_device *sb_dev)
4057 {
4058         return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4059 }
4060 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4061
4062 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4063                      struct net_device *sb_dev)
4064 {
4065         struct sock *sk = skb->sk;
4066         int queue_index = sk_tx_queue_get(sk);
4067
4068         sb_dev = sb_dev ? : dev;
4069
4070         if (queue_index < 0 || skb->ooo_okay ||
4071             queue_index >= dev->real_num_tx_queues) {
4072                 int new_index = get_xps_queue(dev, sb_dev, skb);
4073
4074                 if (new_index < 0)
4075                         new_index = skb_tx_hash(dev, sb_dev, skb);
4076
4077                 if (queue_index != new_index && sk &&
4078                     sk_fullsock(sk) &&
4079                     rcu_access_pointer(sk->sk_dst_cache))
4080                         sk_tx_queue_set(sk, new_index);
4081
4082                 queue_index = new_index;
4083         }
4084
4085         return queue_index;
4086 }
4087 EXPORT_SYMBOL(netdev_pick_tx);
4088
4089 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4090                                          struct sk_buff *skb,
4091                                          struct net_device *sb_dev)
4092 {
4093         int queue_index = 0;
4094
4095 #ifdef CONFIG_XPS
4096         u32 sender_cpu = skb->sender_cpu - 1;
4097
4098         if (sender_cpu >= (u32)NR_CPUS)
4099                 skb->sender_cpu = raw_smp_processor_id() + 1;
4100 #endif
4101
4102         if (dev->real_num_tx_queues != 1) {
4103                 const struct net_device_ops *ops = dev->netdev_ops;
4104
4105                 if (ops->ndo_select_queue)
4106                         queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4107                 else
4108                         queue_index = netdev_pick_tx(dev, skb, sb_dev);
4109
4110                 queue_index = netdev_cap_txqueue(dev, queue_index);
4111         }
4112
4113         skb_set_queue_mapping(skb, queue_index);
4114         return netdev_get_tx_queue(dev, queue_index);
4115 }
4116
4117 /**
4118  *      __dev_queue_xmit - transmit a buffer
4119  *      @skb: buffer to transmit
4120  *      @sb_dev: suboordinate device used for L2 forwarding offload
4121  *
4122  *      Queue a buffer for transmission to a network device. The caller must
4123  *      have set the device and priority and built the buffer before calling
4124  *      this function. The function can be called from an interrupt.
4125  *
4126  *      A negative errno code is returned on a failure. A success does not
4127  *      guarantee the frame will be transmitted as it may be dropped due
4128  *      to congestion or traffic shaping.
4129  *
4130  * -----------------------------------------------------------------------------------
4131  *      I notice this method can also return errors from the queue disciplines,
4132  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
4133  *      be positive.
4134  *
4135  *      Regardless of the return value, the skb is consumed, so it is currently
4136  *      difficult to retry a send to this method.  (You can bump the ref count
4137  *      before sending to hold a reference for retry if you are careful.)
4138  *
4139  *      When calling this method, interrupts MUST be enabled.  This is because
4140  *      the BH enable code must have IRQs enabled so that it will not deadlock.
4141  *          --BLG
4142  */
4143 static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4144 {
4145         struct net_device *dev = skb->dev;
4146         struct netdev_queue *txq;
4147         struct Qdisc *q;
4148         int rc = -ENOMEM;
4149         bool again = false;
4150
4151         skb_reset_mac_header(skb);
4152
4153         if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4154                 __skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4155
4156         /* Disable soft irqs for various locks below. Also
4157          * stops preemption for RCU.
4158          */
4159         rcu_read_lock_bh();
4160
4161         skb_update_prio(skb);
4162
4163         qdisc_pkt_len_init(skb);
4164 #ifdef CONFIG_NET_CLS_ACT
4165         skb->tc_at_ingress = 0;
4166 #endif
4167 #ifdef CONFIG_NET_EGRESS
4168         if (static_branch_unlikely(&egress_needed_key)) {
4169                 if (nf_hook_egress_active()) {
4170                         skb = nf_hook_egress(skb, &rc, dev);
4171                         if (!skb)
4172                                 goto out;
4173                 }
4174                 nf_skip_egress(skb, true);
4175                 skb = sch_handle_egress(skb, &rc, dev);
4176                 if (!skb)
4177                         goto out;
4178                 nf_skip_egress(skb, false);
4179         }
4180 #endif
4181         /* If device/qdisc don't need skb->dst, release it right now while
4182          * its hot in this cpu cache.
4183          */
4184         if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4185                 skb_dst_drop(skb);
4186         else
4187                 skb_dst_force(skb);
4188
4189         txq = netdev_core_pick_tx(dev, skb, sb_dev);
4190         q = rcu_dereference_bh(txq->qdisc);
4191
4192         trace_net_dev_queue(skb);
4193         if (q->enqueue) {
4194                 rc = __dev_xmit_skb(skb, q, dev, txq);
4195                 goto out;
4196         }
4197
4198         /* The device has no queue. Common case for software devices:
4199          * loopback, all the sorts of tunnels...
4200
4201          * Really, it is unlikely that netif_tx_lock protection is necessary
4202          * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4203          * counters.)
4204          * However, it is possible, that they rely on protection
4205          * made by us here.
4206
4207          * Check this and shot the lock. It is not prone from deadlocks.
4208          *Either shot noqueue qdisc, it is even simpler 8)
4209          */
4210         if (dev->flags & IFF_UP) {
4211                 int cpu = smp_processor_id(); /* ok because BHs are off */
4212
4213                 if (txq->xmit_lock_owner != cpu) {
4214                         if (dev_xmit_recursion())
4215                                 goto recursion_alert;
4216
4217                         skb = validate_xmit_skb(skb, dev, &again);
4218                         if (!skb)
4219                                 goto out;
4220
4221                         PRANDOM_ADD_NOISE(skb, dev, txq, jiffies);
4222                         HARD_TX_LOCK(dev, txq, cpu);
4223
4224                         if (!netif_xmit_stopped(txq)) {
4225                                 dev_xmit_recursion_inc();
4226                                 skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4227                                 dev_xmit_recursion_dec();
4228                                 if (dev_xmit_complete(rc)) {
4229                                         HARD_TX_UNLOCK(dev, txq);
4230                                         goto out;
4231                                 }
4232                         }
4233                         HARD_TX_UNLOCK(dev, txq);
4234                         net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4235                                              dev->name);
4236                 } else {
4237                         /* Recursion is detected! It is possible,
4238                          * unfortunately
4239                          */
4240 recursion_alert:
4241                         net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4242                                              dev->name);
4243                 }
4244         }
4245
4246         rc = -ENETDOWN;
4247         rcu_read_unlock_bh();
4248
4249         atomic_long_inc(&dev->tx_dropped);
4250         kfree_skb_list(skb);
4251         return rc;
4252 out:
4253         rcu_read_unlock_bh();
4254         return rc;
4255 }
4256
4257 int dev_queue_xmit(struct sk_buff *skb)
4258 {
4259         return __dev_queue_xmit(skb, NULL);
4260 }
4261 EXPORT_SYMBOL(dev_queue_xmit);
4262
4263 int dev_queue_xmit_accel(struct sk_buff *skb, struct net_device *sb_dev)
4264 {
4265         return __dev_queue_xmit(skb, sb_dev);
4266 }
4267 EXPORT_SYMBOL(dev_queue_xmit_accel);
4268
4269 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4270 {
4271         struct net_device *dev = skb->dev;
4272         struct sk_buff *orig_skb = skb;
4273         struct netdev_queue *txq;
4274         int ret = NETDEV_TX_BUSY;
4275         bool again = false;
4276
4277         if (unlikely(!netif_running(dev) ||
4278                      !netif_carrier_ok(dev)))
4279                 goto drop;
4280
4281         skb = validate_xmit_skb_list(skb, dev, &again);
4282         if (skb != orig_skb)
4283                 goto drop;
4284
4285         skb_set_queue_mapping(skb, queue_id);
4286         txq = skb_get_tx_queue(dev, skb);
4287         PRANDOM_ADD_NOISE(skb, dev, txq, jiffies);
4288
4289         local_bh_disable();
4290
4291         dev_xmit_recursion_inc();
4292         HARD_TX_LOCK(dev, txq, smp_processor_id());
4293         if (!netif_xmit_frozen_or_drv_stopped(txq))
4294                 ret = netdev_start_xmit(skb, dev, txq, false);
4295         HARD_TX_UNLOCK(dev, txq);
4296         dev_xmit_recursion_dec();
4297
4298         local_bh_enable();
4299         return ret;
4300 drop:
4301         atomic_long_inc(&dev->tx_dropped);
4302         kfree_skb_list(skb);
4303         return NET_XMIT_DROP;
4304 }
4305 EXPORT_SYMBOL(__dev_direct_xmit);
4306
4307 /*************************************************************************
4308  *                      Receiver routines
4309  *************************************************************************/
4310
4311 int netdev_max_backlog __read_mostly = 1000;
4312 EXPORT_SYMBOL(netdev_max_backlog);
4313
4314 int netdev_tstamp_prequeue __read_mostly = 1;
4315 int netdev_budget __read_mostly = 300;
4316 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4317 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4318 int weight_p __read_mostly = 64;           /* old backlog weight */
4319 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4320 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4321 int dev_rx_weight __read_mostly = 64;
4322 int dev_tx_weight __read_mostly = 64;
4323 /* Maximum number of GRO_NORMAL skbs to batch up for list-RX */
4324 int gro_normal_batch __read_mostly = 8;
4325
4326 /* Called with irq disabled */
4327 static inline void ____napi_schedule(struct softnet_data *sd,
4328                                      struct napi_struct *napi)
4329 {
4330         struct task_struct *thread;
4331
4332         if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4333                 /* Paired with smp_mb__before_atomic() in
4334                  * napi_enable()/dev_set_threaded().
4335                  * Use READ_ONCE() to guarantee a complete
4336                  * read on napi->thread. Only call
4337                  * wake_up_process() when it's not NULL.
4338                  */
4339                 thread = READ_ONCE(napi->thread);
4340                 if (thread) {
4341                         /* Avoid doing set_bit() if the thread is in
4342                          * INTERRUPTIBLE state, cause napi_thread_wait()
4343                          * makes sure to proceed with napi polling
4344                          * if the thread is explicitly woken from here.
4345                          */
4346                         if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4347                                 set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4348                         wake_up_process(thread);
4349                         return;
4350                 }
4351         }
4352
4353         list_add_tail(&napi->poll_list, &sd->poll_list);
4354         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4355 }
4356
4357 #ifdef CONFIG_RPS
4358
4359 /* One global table that all flow-based protocols share. */
4360 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4361 EXPORT_SYMBOL(rps_sock_flow_table);
4362 u32 rps_cpu_mask __read_mostly;
4363 EXPORT_SYMBOL(rps_cpu_mask);
4364
4365 struct static_key_false rps_needed __read_mostly;
4366 EXPORT_SYMBOL(rps_needed);
4367 struct static_key_false rfs_needed __read_mostly;
4368 EXPORT_SYMBOL(rfs_needed);
4369
4370 static struct rps_dev_flow *
4371 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4372             struct rps_dev_flow *rflow, u16 next_cpu)
4373 {
4374         if (next_cpu < nr_cpu_ids) {
4375 #ifdef CONFIG_RFS_ACCEL
4376                 struct netdev_rx_queue *rxqueue;
4377                 struct rps_dev_flow_table *flow_table;
4378                 struct rps_dev_flow *old_rflow;
4379                 u32 flow_id;
4380                 u16 rxq_index;
4381                 int rc;
4382
4383                 /* Should we steer this flow to a different hardware queue? */
4384                 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4385                     !(dev->features & NETIF_F_NTUPLE))
4386                         goto out;
4387                 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4388                 if (rxq_index == skb_get_rx_queue(skb))
4389                         goto out;
4390
4391                 rxqueue = dev->_rx + rxq_index;
4392                 flow_table = rcu_dereference(rxqueue->rps_flow_table);
4393                 if (!flow_table)
4394                         goto out;
4395                 flow_id = skb_get_hash(skb) & flow_table->mask;
4396                 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4397                                                         rxq_index, flow_id);
4398                 if (rc < 0)
4399                         goto out;
4400                 old_rflow = rflow;
4401                 rflow = &flow_table->flows[flow_id];
4402                 rflow->filter = rc;
4403                 if (old_rflow->filter == rflow->filter)
4404                         old_rflow->filter = RPS_NO_FILTER;
4405         out:
4406 #endif
4407                 rflow->last_qtail =
4408                         per_cpu(softnet_data, next_cpu).input_queue_head;
4409         }
4410
4411         rflow->cpu = next_cpu;
4412         return rflow;
4413 }
4414
4415 /*
4416  * get_rps_cpu is called from netif_receive_skb and returns the target
4417  * CPU from the RPS map of the receiving queue for a given skb.
4418  * rcu_read_lock must be held on entry.
4419  */
4420 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4421                        struct rps_dev_flow **rflowp)
4422 {
4423         const struct rps_sock_flow_table *sock_flow_table;
4424         struct netdev_rx_queue *rxqueue = dev->_rx;
4425         struct rps_dev_flow_table *flow_table;
4426         struct rps_map *map;
4427         int cpu = -1;
4428         u32 tcpu;
4429         u32 hash;
4430
4431         if (skb_rx_queue_recorded(skb)) {
4432                 u16 index = skb_get_rx_queue(skb);
4433
4434                 if (unlikely(index >= dev->real_num_rx_queues)) {
4435                         WARN_ONCE(dev->real_num_rx_queues > 1,
4436                                   "%s received packet on queue %u, but number "
4437                                   "of RX queues is %u\n",
4438                                   dev->name, index, dev->real_num_rx_queues);
4439                         goto done;
4440                 }
4441                 rxqueue += index;
4442         }
4443
4444         /* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4445
4446         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4447         map = rcu_dereference(rxqueue->rps_map);
4448         if (!flow_table && !map)
4449                 goto done;
4450
4451         skb_reset_network_header(skb);
4452         hash = skb_get_hash(skb);
4453         if (!hash)
4454                 goto done;
4455
4456         sock_flow_table = rcu_dereference(rps_sock_flow_table);
4457         if (flow_table && sock_flow_table) {
4458                 struct rps_dev_flow *rflow;
4459                 u32 next_cpu;
4460                 u32 ident;
4461
4462                 /* First check into global flow table if there is a match */
4463                 ident = sock_flow_table->ents[hash & sock_flow_table->mask];
4464                 if ((ident ^ hash) & ~rps_cpu_mask)
4465                         goto try_rps;
4466
4467                 next_cpu = ident & rps_cpu_mask;
4468
4469                 /* OK, now we know there is a match,
4470                  * we can look at the local (per receive queue) flow table
4471                  */
4472                 rflow = &flow_table->flows[hash & flow_table->mask];
4473                 tcpu = rflow->cpu;
4474
4475                 /*
4476                  * If the desired CPU (where last recvmsg was done) is
4477                  * different from current CPU (one in the rx-queue flow
4478                  * table entry), switch if one of the following holds:
4479                  *   - Current CPU is unset (>= nr_cpu_ids).
4480                  *   - Current CPU is offline.
4481                  *   - The current CPU's queue tail has advanced beyond the
4482                  *     last packet that was enqueued using this table entry.
4483                  *     This guarantees that all previous packets for the flow
4484                  *     have been dequeued, thus preserving in order delivery.
4485                  */
4486                 if (unlikely(tcpu != next_cpu) &&
4487                     (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4488                      ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4489                       rflow->last_qtail)) >= 0)) {
4490                         tcpu = next_cpu;
4491                         rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4492                 }
4493
4494                 if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4495                         *rflowp = rflow;
4496                         cpu = tcpu;
4497                         goto done;
4498                 }
4499         }
4500
4501 try_rps:
4502
4503         if (map) {
4504                 tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4505                 if (cpu_online(tcpu)) {
4506                         cpu = tcpu;
4507                         goto done;
4508                 }
4509         }
4510
4511 done:
4512         return cpu;
4513 }
4514
4515 #ifdef CONFIG_RFS_ACCEL
4516
4517 /**
4518  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4519  * @dev: Device on which the filter was set
4520  * @rxq_index: RX queue index
4521  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4522  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4523  *
4524  * Drivers that implement ndo_rx_flow_steer() should periodically call
4525  * this function for each installed filter and remove the filters for
4526  * which it returns %true.
4527  */
4528 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4529                          u32 flow_id, u16 filter_id)
4530 {
4531         struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4532         struct rps_dev_flow_table *flow_table;
4533         struct rps_dev_flow *rflow;
4534         bool expire = true;
4535         unsigned int cpu;
4536
4537         rcu_read_lock();
4538         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4539         if (flow_table && flow_id <= flow_table->mask) {
4540                 rflow = &flow_table->flows[flow_id];
4541                 cpu = READ_ONCE(rflow->cpu);
4542                 if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4543                     ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4544                            rflow->last_qtail) <
4545                      (int)(10 * flow_table->mask)))
4546                         expire = false;
4547         }
4548         rcu_read_unlock();
4549         return expire;
4550 }
4551 EXPORT_SYMBOL(rps_may_expire_flow);
4552
4553 #endif /* CONFIG_RFS_ACCEL */
4554
4555 /* Called from hardirq (IPI) context */
4556 static void rps_trigger_softirq(void *data)
4557 {
4558         struct softnet_data *sd = data;
4559
4560         ____napi_schedule(sd, &sd->backlog);
4561         sd->received_rps++;
4562 }
4563
4564 #endif /* CONFIG_RPS */
4565
4566 /*
4567  * Check if this softnet_data structure is another cpu one
4568  * If yes, queue it to our IPI list and return 1
4569  * If no, return 0
4570  */
4571 static int rps_ipi_queued(struct softnet_data *sd)
4572 {
4573 #ifdef CONFIG_RPS
4574         struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4575
4576         if (sd != mysd) {
4577                 sd->rps_ipi_next = mysd->rps_ipi_list;
4578                 mysd->rps_ipi_list = sd;
4579
4580                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4581                 return 1;
4582         }
4583 #endif /* CONFIG_RPS */
4584         return 0;
4585 }
4586
4587 #ifdef CONFIG_NET_FLOW_LIMIT
4588 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4589 #endif
4590
4591 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4592 {
4593 #ifdef CONFIG_NET_FLOW_LIMIT
4594         struct sd_flow_limit *fl;
4595         struct softnet_data *sd;
4596         unsigned int old_flow, new_flow;
4597
4598         if (qlen < (netdev_max_backlog >> 1))
4599                 return false;
4600
4601         sd = this_cpu_ptr(&softnet_data);
4602
4603         rcu_read_lock();
4604         fl = rcu_dereference(sd->flow_limit);
4605         if (fl) {
4606                 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4607                 old_flow = fl->history[fl->history_head];
4608                 fl->history[fl->history_head] = new_flow;
4609
4610                 fl->history_head++;
4611                 fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4612
4613                 if (likely(fl->buckets[old_flow]))
4614                         fl->buckets[old_flow]--;
4615
4616                 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4617                         fl->count++;
4618                         rcu_read_unlock();
4619                         return true;
4620                 }
4621         }
4622         rcu_read_unlock();
4623 #endif
4624         return false;
4625 }
4626
4627 /*
4628  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4629  * queue (may be a remote CPU queue).
4630  */
4631 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4632                               unsigned int *qtail)
4633 {
4634         struct softnet_data *sd;
4635         unsigned long flags;
4636         unsigned int qlen;
4637
4638         sd = &per_cpu(softnet_data, cpu);
4639
4640         local_irq_save(flags);
4641
4642         rps_lock(sd);
4643         if (!netif_running(skb->dev))
4644                 goto drop;
4645         qlen = skb_queue_len(&sd->input_pkt_queue);
4646         if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
4647                 if (qlen) {
4648 enqueue:
4649                         __skb_queue_tail(&sd->input_pkt_queue, skb);
4650                         input_queue_tail_incr_save(sd, qtail);
4651                         rps_unlock(sd);
4652                         local_irq_restore(flags);
4653                         return NET_RX_SUCCESS;
4654                 }
4655
4656                 /* Schedule NAPI for backlog device
4657                  * We can use non atomic operation since we own the queue lock
4658                  */
4659                 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
4660                         if (!rps_ipi_queued(sd))
4661                                 ____napi_schedule(sd, &sd->backlog);
4662                 }
4663                 goto enqueue;
4664         }
4665
4666 drop:
4667         sd->dropped++;
4668         rps_unlock(sd);
4669
4670         local_irq_restore(flags);
4671
4672         atomic_long_inc(&skb->dev->rx_dropped);
4673         kfree_skb(skb);
4674         return NET_RX_DROP;
4675 }
4676
4677 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4678 {
4679         struct net_device *dev = skb->dev;
4680         struct netdev_rx_queue *rxqueue;
4681
4682         rxqueue = dev->_rx;
4683
4684         if (skb_rx_queue_recorded(skb)) {
4685                 u16 index = skb_get_rx_queue(skb);
4686
4687                 if (unlikely(index >= dev->real_num_rx_queues)) {
4688                         WARN_ONCE(dev->real_num_rx_queues > 1,
4689                                   "%s received packet on queue %u, but number "
4690                                   "of RX queues is %u\n",
4691                                   dev->name, index, dev->real_num_rx_queues);
4692
4693                         return rxqueue; /* Return first rxqueue */
4694                 }
4695                 rxqueue += index;
4696         }
4697         return rxqueue;
4698 }
4699
4700 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4701                              struct bpf_prog *xdp_prog)
4702 {
4703         void *orig_data, *orig_data_end, *hard_start;
4704         struct netdev_rx_queue *rxqueue;
4705         bool orig_bcast, orig_host;
4706         u32 mac_len, frame_sz;
4707         __be16 orig_eth_type;
4708         struct ethhdr *eth;
4709         u32 metalen, act;
4710         int off;
4711
4712         /* The XDP program wants to see the packet starting at the MAC
4713          * header.
4714          */
4715         mac_len = skb->data - skb_mac_header(skb);
4716         hard_start = skb->data - skb_headroom(skb);
4717
4718         /* SKB "head" area always have tailroom for skb_shared_info */
4719         frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4720         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4721
4722         rxqueue = netif_get_rxqueue(skb);
4723         xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4724         xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4725                          skb_headlen(skb) + mac_len, true);
4726
4727         orig_data_end = xdp->data_end;
4728         orig_data = xdp->data;
4729         eth = (struct ethhdr *)xdp->data;
4730         orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4731         orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4732         orig_eth_type = eth->h_proto;
4733
4734         act = bpf_prog_run_xdp(xdp_prog, xdp);
4735
4736         /* check if bpf_xdp_adjust_head was used */
4737         off = xdp->data - orig_data;
4738         if (off) {
4739                 if (off > 0)
4740                         __skb_pull(skb, off);
4741                 else if (off < 0)
4742                         __skb_push(skb, -off);
4743
4744                 skb->mac_header += off;
4745                 skb_reset_network_header(skb);
4746         }
4747
4748         /* check if bpf_xdp_adjust_tail was used */
4749         off = xdp->data_end - orig_data_end;
4750         if (off != 0) {
4751                 skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4752                 skb->len += off; /* positive on grow, negative on shrink */
4753         }
4754
4755         /* check if XDP changed eth hdr such SKB needs update */
4756         eth = (struct ethhdr *)xdp->data;
4757         if ((orig_eth_type != eth->h_proto) ||
4758             (orig_host != ether_addr_equal_64bits(eth->h_dest,
4759                                                   skb->dev->dev_addr)) ||
4760             (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4761                 __skb_push(skb, ETH_HLEN);
4762                 skb->pkt_type = PACKET_HOST;
4763                 skb->protocol = eth_type_trans(skb, skb->dev);
4764         }
4765
4766         /* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4767          * before calling us again on redirect path. We do not call do_redirect
4768          * as we leave that up to the caller.
4769          *
4770          * Caller is responsible for managing lifetime of skb (i.e. calling
4771          * kfree_skb in response to actions it cannot handle/XDP_DROP).
4772          */
4773         switch (act) {
4774         case XDP_REDIRECT:
4775         case XDP_TX:
4776                 __skb_push(skb, mac_len);
4777                 break;
4778         case XDP_PASS:
4779                 metalen = xdp->data - xdp->data_meta;
4780                 if (metalen)
4781                         skb_metadata_set(skb, metalen);
4782                 break;
4783         }
4784
4785         return act;
4786 }
4787
4788 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4789                                      struct xdp_buff *xdp,
4790                                      struct bpf_prog *xdp_prog)
4791 {
4792         u32 act = XDP_DROP;
4793
4794         /* Reinjected packets coming from act_mirred or similar should
4795          * not get XDP generic processing.
4796          */
4797         if (skb_is_redirected(skb))
4798                 return XDP_PASS;
4799
4800         /* XDP packets must be linear and must have sufficient headroom
4801          * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4802          * native XDP provides, thus we need to do it here as well.
4803          */
4804         if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4805             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4806                 int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4807                 int troom = skb->tail + skb->data_len - skb->end;
4808
4809                 /* In case we have to go down the path and also linearize,
4810                  * then lets do the pskb_expand_head() work just once here.
4811                  */
4812                 if (pskb_expand_head(skb,
4813                                      hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4814                                      troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4815                         goto do_drop;
4816                 if (skb_linearize(skb))
4817                         goto do_drop;
4818         }
4819
4820         act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4821         switch (act) {
4822         case XDP_REDIRECT:
4823         case XDP_TX:
4824         case XDP_PASS:
4825                 break;
4826         default:
4827                 bpf_warn_invalid_xdp_action(act);
4828                 fallthrough;
4829         case XDP_ABORTED:
4830                 trace_xdp_exception(skb->dev, xdp_prog, act);
4831                 fallthrough;
4832         case XDP_DROP:
4833         do_drop:
4834                 kfree_skb(skb);
4835                 break;
4836         }
4837
4838         return act;
4839 }
4840
4841 /* When doing generic XDP we have to bypass the qdisc layer and the
4842  * network taps in order to match in-driver-XDP behavior.
4843  */
4844 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4845 {
4846         struct net_device *dev = skb->dev;
4847         struct netdev_queue *txq;
4848         bool free_skb = true;
4849         int cpu, rc;
4850
4851         txq = netdev_core_pick_tx(dev, skb, NULL);
4852         cpu = smp_processor_id();
4853         HARD_TX_LOCK(dev, txq, cpu);
4854         if (!netif_xmit_stopped(txq)) {
4855                 rc = netdev_start_xmit(skb, dev, txq, 0);
4856                 if (dev_xmit_complete(rc))
4857                         free_skb = false;
4858         }
4859         HARD_TX_UNLOCK(dev, txq);
4860         if (free_skb) {
4861                 trace_xdp_exception(dev, xdp_prog, XDP_TX);
4862                 kfree_skb(skb);
4863         }
4864 }
4865
4866 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4867
4868 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4869 {
4870         if (xdp_prog) {
4871                 struct xdp_buff xdp;
4872                 u32 act;
4873                 int err;
4874
4875                 act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4876                 if (act != XDP_PASS) {
4877                         switch (act) {
4878                         case XDP_REDIRECT:
4879                                 err = xdp_do_generic_redirect(skb->dev, skb,
4880                                                               &xdp, xdp_prog);
4881                                 if (err)
4882                                         goto out_redir;
4883                                 break;
4884                         case XDP_TX:
4885                                 generic_xdp_tx(skb, xdp_prog);
4886                                 break;
4887                         }
4888                         return XDP_DROP;
4889                 }
4890         }
4891         return XDP_PASS;
4892 out_redir:
4893         kfree_skb(skb);
4894         return XDP_DROP;
4895 }
4896 EXPORT_SYMBOL_GPL(do_xdp_generic);
4897
4898 static int netif_rx_internal(struct sk_buff *skb)
4899 {
4900         int ret;
4901
4902         net_timestamp_check(netdev_tstamp_prequeue, skb);
4903
4904         trace_netif_rx(skb);
4905
4906 #ifdef CONFIG_RPS
4907         if (static_branch_unlikely(&rps_needed)) {
4908                 struct rps_dev_flow voidflow, *rflow = &voidflow;
4909                 int cpu;
4910
4911                 preempt_disable();
4912                 rcu_read_lock();
4913
4914                 cpu = get_rps_cpu(skb->dev, skb, &rflow);
4915                 if (cpu < 0)
4916                         cpu = smp_processor_id();
4917
4918                 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4919
4920                 rcu_read_unlock();
4921                 preempt_enable();
4922         } else
4923 #endif
4924         {
4925                 unsigned int qtail;
4926
4927                 ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
4928                 put_cpu();
4929         }
4930         return ret;
4931 }
4932
4933 /**
4934  *      netif_rx        -       post buffer to the network code
4935  *      @skb: buffer to post
4936  *
4937  *      This function receives a packet from a device driver and queues it for
4938  *      the upper (protocol) levels to process.  It always succeeds. The buffer
4939  *      may be dropped during processing for congestion control or by the
4940  *      protocol layers.
4941  *
4942  *      return values:
4943  *      NET_RX_SUCCESS  (no congestion)
4944  *      NET_RX_DROP     (packet was dropped)
4945  *
4946  */
4947
4948 int netif_rx(struct sk_buff *skb)
4949 {
4950         int ret;
4951
4952         trace_netif_rx_entry(skb);
4953
4954         ret = netif_rx_internal(skb);
4955         trace_netif_rx_exit(ret);
4956
4957         return ret;
4958 }
4959 EXPORT_SYMBOL(netif_rx);
4960
4961 int netif_rx_ni(struct sk_buff *skb)
4962 {
4963         int err;
4964
4965         trace_netif_rx_ni_entry(skb);
4966
4967         preempt_disable();
4968         err = netif_rx_internal(skb);
4969         if (local_softirq_pending())
4970                 do_softirq();
4971         preempt_enable();
4972         trace_netif_rx_ni_exit(err);
4973
4974         return err;
4975 }
4976 EXPORT_SYMBOL(netif_rx_ni);
4977
4978 int netif_rx_any_context(struct sk_buff *skb)
4979 {
4980         /*
4981          * If invoked from contexts which do not invoke bottom half
4982          * processing either at return from interrupt or when softrqs are
4983          * reenabled, use netif_rx_ni() which invokes bottomhalf processing
4984          * directly.
4985          */
4986         if (in_interrupt())
4987                 return netif_rx(skb);
4988         else
4989                 return netif_rx_ni(skb);
4990 }
4991 EXPORT_SYMBOL(netif_rx_any_context);
4992
4993 static __latent_entropy void net_tx_action(struct softirq_action *h)
4994 {
4995         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
4996
4997         if (sd->completion_queue) {
4998                 struct sk_buff *clist;
4999
5000                 local_irq_disable();
5001                 clist = sd->completion_queue;
5002                 sd->completion_queue = NULL;
5003                 local_irq_enable();
5004
5005                 while (clist) {
5006                         struct sk_buff *skb = clist;
5007
5008                         clist = clist->next;
5009
5010                         WARN_ON(refcount_read(&skb->users));
5011                         if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
5012                                 trace_consume_skb(skb);
5013                         else
5014                                 trace_kfree_skb(skb, net_tx_action);
5015
5016                         if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5017                                 __kfree_skb(skb);
5018                         else
5019                                 __kfree_skb_defer(skb);
5020                 }
5021         }
5022
5023         if (sd->output_queue) {
5024                 struct Qdisc *head;
5025
5026                 local_irq_disable();
5027                 head = sd->output_queue;
5028                 sd->output_queue = NULL;
5029                 sd->output_queue_tailp = &sd->output_queue;
5030                 local_irq_enable();
5031
5032                 rcu_read_lock();
5033
5034                 while (head) {
5035                         struct Qdisc *q = head;
5036                         spinlock_t *root_lock = NULL;
5037
5038                         head = head->next_sched;
5039
5040                         /* We need to make sure head->next_sched is read
5041                          * before clearing __QDISC_STATE_SCHED
5042                          */
5043                         smp_mb__before_atomic();
5044
5045                         if (!(q->flags & TCQ_F_NOLOCK)) {
5046                                 root_lock = qdisc_lock(q);
5047                                 spin_lock(root_lock);
5048                         } else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5049                                                      &q->state))) {
5050                                 /* There is a synchronize_net() between
5051                                  * STATE_DEACTIVATED flag being set and
5052                                  * qdisc_reset()/some_qdisc_is_busy() in
5053                                  * dev_deactivate(), so we can safely bail out
5054                                  * early here to avoid data race between
5055                                  * qdisc_deactivate() and some_qdisc_is_busy()
5056                                  * for lockless qdisc.
5057                                  */
5058                                 clear_bit(__QDISC_STATE_SCHED, &q->state);
5059                                 continue;
5060                         }
5061
5062                         clear_bit(__QDISC_STATE_SCHED, &q->state);
5063                         qdisc_run(q);
5064                         if (root_lock)
5065                                 spin_unlock(root_lock);
5066                 }
5067
5068                 rcu_read_unlock();
5069         }
5070
5071         xfrm_dev_backlog(sd);
5072 }
5073
5074 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5075 /* This hook is defined here for ATM LANE */
5076 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5077                              unsigned char *addr) __read_mostly;
5078 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5079 #endif
5080
5081 static inline struct sk_buff *
5082 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5083                    struct net_device *orig_dev, bool *another)
5084 {
5085 #ifdef CONFIG_NET_CLS_ACT
5086         struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5087         struct tcf_result cl_res;
5088
5089         /* If there's at least one ingress present somewhere (so
5090          * we get here via enabled static key), remaining devices
5091          * that are not configured with an ingress qdisc will bail
5092          * out here.
5093          */
5094         if (!miniq)
5095                 return skb;
5096
5097         if (*pt_prev) {
5098                 *ret = deliver_skb(skb, *pt_prev, orig_dev);
5099                 *pt_prev = NULL;
5100         }
5101
5102         qdisc_skb_cb(skb)->pkt_len = skb->len;
5103         qdisc_skb_cb(skb)->mru = 0;
5104         qdisc_skb_cb(skb)->post_ct = false;
5105         skb->tc_at_ingress = 1;
5106         mini_qdisc_bstats_cpu_update(miniq, skb);
5107
5108         switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5109         case TC_ACT_OK:
5110         case TC_ACT_RECLASSIFY:
5111                 skb->tc_index = TC_H_MIN(cl_res.classid);
5112                 break;
5113         case TC_ACT_SHOT:
5114                 mini_qdisc_qstats_cpu_drop(miniq);
5115                 kfree_skb(skb);
5116                 return NULL;
5117         case TC_ACT_STOLEN:
5118         case TC_ACT_QUEUED:
5119         case TC_ACT_TRAP:
5120                 consume_skb(skb);
5121                 return NULL;
5122         case TC_ACT_REDIRECT:
5123                 /* skb_mac_header check was done by cls/act_bpf, so
5124                  * we can safely push the L2 header back before
5125                  * redirecting to another netdev
5126                  */
5127                 __skb_push(skb, skb->mac_len);
5128                 if (skb_do_redirect(skb) == -EAGAIN) {
5129                         __skb_pull(skb, skb->mac_len);
5130                         *another = true;
5131                         break;
5132                 }
5133                 return NULL;
5134         case TC_ACT_CONSUMED:
5135                 return NULL;
5136         default:
5137                 break;
5138         }
5139 #endif /* CONFIG_NET_CLS_ACT */
5140         return skb;
5141 }
5142
5143 /**
5144  *      netdev_is_rx_handler_busy - check if receive handler is registered
5145  *      @dev: device to check
5146  *
5147  *      Check if a receive handler is already registered for a given device.
5148  *      Return true if there one.
5149  *
5150  *      The caller must hold the rtnl_mutex.
5151  */
5152 bool netdev_is_rx_handler_busy(struct net_device *dev)
5153 {
5154         ASSERT_RTNL();
5155         return dev && rtnl_dereference(dev->rx_handler);
5156 }
5157 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5158
5159 /**
5160  *      netdev_rx_handler_register - register receive handler
5161  *      @dev: device to register a handler for
5162  *      @rx_handler: receive handler to register
5163  *      @rx_handler_data: data pointer that is used by rx handler
5164  *
5165  *      Register a receive handler for a device. This handler will then be
5166  *      called from __netif_receive_skb. A negative errno code is returned
5167  *      on a failure.
5168  *
5169  *      The caller must hold the rtnl_mutex.
5170  *
5171  *      For a general description of rx_handler, see enum rx_handler_result.
5172  */
5173 int netdev_rx_handler_register(struct net_device *dev,
5174                                rx_handler_func_t *rx_handler,
5175                                void *rx_handler_data)
5176 {
5177         if (netdev_is_rx_handler_busy(dev))
5178                 return -EBUSY;
5179
5180         if (dev->priv_flags & IFF_NO_RX_HANDLER)
5181                 return -EINVAL;
5182
5183         /* Note: rx_handler_data must be set before rx_handler */
5184         rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5185         rcu_assign_pointer(dev->rx_handler, rx_handler);
5186
5187         return 0;
5188 }
5189 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5190
5191 /**
5192  *      netdev_rx_handler_unregister - unregister receive handler
5193  *      @dev: device to unregister a handler from
5194  *
5195  *      Unregister a receive handler from a device.
5196  *
5197  *      The caller must hold the rtnl_mutex.
5198  */
5199 void netdev_rx_handler_unregister(struct net_device *dev)
5200 {
5201
5202         ASSERT_RTNL();
5203         RCU_INIT_POINTER(dev->rx_handler, NULL);
5204         /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5205          * section has a guarantee to see a non NULL rx_handler_data
5206          * as well.
5207          */
5208         synchronize_net();
5209         RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5210 }
5211 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5212
5213 /*
5214  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5215  * the special handling of PFMEMALLOC skbs.
5216  */
5217 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5218 {
5219         switch (skb->protocol) {
5220         case htons(ETH_P_ARP):
5221         case htons(ETH_P_IP):
5222         case htons(ETH_P_IPV6):
5223         case htons(ETH_P_8021Q):
5224         case htons(ETH_P_8021AD):
5225                 return true;
5226         default:
5227                 return false;
5228         }
5229 }
5230
5231 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5232                              int *ret, struct net_device *orig_dev)
5233 {
5234         if (nf_hook_ingress_active(skb)) {
5235                 int ingress_retval;
5236
5237                 if (*pt_prev) {
5238                         *ret = deliver_skb(skb, *pt_prev, orig_dev);
5239                         *pt_prev = NULL;
5240                 }
5241
5242                 rcu_read_lock();
5243                 ingress_retval = nf_hook_ingress(skb);
5244                 rcu_read_unlock();
5245                 return ingress_retval;
5246         }
5247         return 0;
5248 }
5249
5250 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5251                                     struct packet_type **ppt_prev)
5252 {
5253         struct packet_type *ptype, *pt_prev;
5254         rx_handler_func_t *rx_handler;
5255         struct sk_buff *skb = *pskb;
5256         struct net_device *orig_dev;
5257         bool deliver_exact = false;
5258         int ret = NET_RX_DROP;
5259         __be16 type;
5260
5261         net_timestamp_check(!netdev_tstamp_prequeue, skb);
5262
5263         trace_netif_receive_skb(skb);
5264
5265         orig_dev = skb->dev;
5266
5267         skb_reset_network_header(skb);
5268         if (!skb_transport_header_was_set(skb))
5269                 skb_reset_transport_header(skb);
5270         skb_reset_mac_len(skb);
5271
5272         pt_prev = NULL;
5273
5274 another_round:
5275         skb->skb_iif = skb->dev->ifindex;
5276
5277         __this_cpu_inc(softnet_data.processed);
5278
5279         if (static_branch_unlikely(&generic_xdp_needed_key)) {
5280                 int ret2;
5281
5282                 migrate_disable();
5283                 ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5284                 migrate_enable();
5285
5286                 if (ret2 != XDP_PASS) {
5287                         ret = NET_RX_DROP;
5288                         goto out;
5289                 }
5290         }
5291
5292         if (eth_type_vlan(skb->protocol)) {
5293                 skb = skb_vlan_untag(skb);
5294                 if (unlikely(!skb))
5295                         goto out;
5296         }
5297
5298         if (skb_skip_tc_classify(skb))
5299                 goto skip_classify;
5300
5301         if (pfmemalloc)
5302                 goto skip_taps;
5303
5304         list_for_each_entry_rcu(ptype, &ptype_all, list) {
5305                 if (pt_prev)
5306                         ret = deliver_skb(skb, pt_prev, orig_dev);
5307                 pt_prev = ptype;
5308         }
5309
5310         list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5311                 if (pt_prev)
5312                         ret = deliver_skb(skb, pt_prev, orig_dev);
5313                 pt_prev = ptype;
5314         }
5315
5316 skip_taps:
5317 #ifdef CONFIG_NET_INGRESS
5318         if (static_branch_unlikely(&ingress_needed_key)) {
5319                 bool another = false;
5320
5321                 nf_skip_egress(skb, true);
5322                 skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5323                                          &another);
5324                 if (another)
5325                         goto another_round;
5326                 if (!skb)
5327                         goto out;
5328
5329                 nf_skip_egress(skb, false);
5330                 if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5331                         goto out;
5332         }
5333 #endif
5334         skb_reset_redirect(skb);
5335 skip_classify:
5336         if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5337                 goto drop;
5338
5339         if (skb_vlan_tag_present(skb)) {
5340                 if (pt_prev) {
5341                         ret = deliver_skb(skb, pt_prev, orig_dev);
5342                         pt_prev = NULL;
5343                 }
5344                 if (vlan_do_receive(&skb))
5345                         goto another_round;
5346                 else if (unlikely(!skb))
5347                         goto out;
5348         }
5349
5350         rx_handler = rcu_dereference(skb->dev->rx_handler);
5351         if (rx_handler) {
5352                 if (pt_prev) {
5353                         ret = deliver_skb(skb, pt_prev, orig_dev);
5354                         pt_prev = NULL;
5355                 }
5356                 switch (rx_handler(&skb)) {
5357                 case RX_HANDLER_CONSUMED:
5358                         ret = NET_RX_SUCCESS;
5359                         goto out;
5360                 case RX_HANDLER_ANOTHER:
5361                         goto another_round;
5362                 case RX_HANDLER_EXACT:
5363                         deliver_exact = true;
5364                         break;
5365                 case RX_HANDLER_PASS:
5366                         break;
5367                 default:
5368                         BUG();
5369                 }
5370         }
5371
5372         if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5373 check_vlan_id:
5374                 if (skb_vlan_tag_get_id(skb)) {
5375                         /* Vlan id is non 0 and vlan_do_receive() above couldn't
5376                          * find vlan device.
5377                          */
5378                         skb->pkt_type = PACKET_OTHERHOST;
5379                 } else if (eth_type_vlan(skb->protocol)) {
5380                         /* Outer header is 802.1P with vlan 0, inner header is
5381                          * 802.1Q or 802.1AD and vlan_do_receive() above could
5382                          * not find vlan dev for vlan id 0.
5383                          */
5384                         __vlan_hwaccel_clear_tag(skb);
5385                         skb = skb_vlan_untag(skb);
5386                         if (unlikely(!skb))
5387                                 goto out;
5388                         if (vlan_do_receive(&skb))
5389                                 /* After stripping off 802.1P header with vlan 0
5390                                  * vlan dev is found for inner header.
5391                                  */
5392                                 goto another_round;
5393                         else if (unlikely(!skb))
5394                                 goto out;
5395                         else
5396                                 /* We have stripped outer 802.1P vlan 0 header.
5397                                  * But could not find vlan dev.
5398                                  * check again for vlan id to set OTHERHOST.
5399                                  */
5400                                 goto check_vlan_id;
5401                 }
5402                 /* Note: we might in the future use prio bits
5403                  * and set skb->priority like in vlan_do_receive()
5404                  * For the time being, just ignore Priority Code Point
5405                  */
5406                 __vlan_hwaccel_clear_tag(skb);
5407         }
5408
5409         type = skb->protocol;
5410
5411         /* deliver only exact match when indicated */
5412         if (likely(!deliver_exact)) {
5413                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5414                                        &ptype_base[ntohs(type) &
5415                                                    PTYPE_HASH_MASK]);
5416         }
5417
5418         deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5419                                &orig_dev->ptype_specific);
5420
5421         if (unlikely(skb->dev != orig_dev)) {
5422                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5423                                        &skb->dev->ptype_specific);
5424         }
5425
5426         if (pt_prev) {
5427                 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5428                         goto drop;
5429                 *ppt_prev = pt_prev;
5430         } else {
5431 drop:
5432                 if (!deliver_exact)
5433                         atomic_long_inc(&skb->dev->rx_dropped);
5434                 else
5435                         atomic_long_inc(&skb->dev->rx_nohandler);
5436                 kfree_skb(skb);
5437                 /* Jamal, now you will not able to escape explaining
5438                  * me how you were going to use this. :-)
5439                  */
5440                 ret = NET_RX_DROP;
5441         }
5442
5443 out:
5444         /* The invariant here is that if *ppt_prev is not NULL
5445          * then skb should also be non-NULL.
5446          *
5447          * Apparently *ppt_prev assignment above holds this invariant due to
5448          * skb dereferencing near it.
5449          */
5450         *pskb = skb;
5451         return ret;
5452 }
5453
5454 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5455 {
5456         struct net_device *orig_dev = skb->dev;
5457         struct packet_type *pt_prev = NULL;
5458         int ret;
5459
5460         ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5461         if (pt_prev)
5462                 ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5463                                          skb->dev, pt_prev, orig_dev);
5464         return ret;
5465 }
5466
5467 /**
5468  *      netif_receive_skb_core - special purpose version of netif_receive_skb
5469  *      @skb: buffer to process
5470  *
5471  *      More direct receive version of netif_receive_skb().  It should
5472  *      only be used by callers that have a need to skip RPS and Generic XDP.
5473  *      Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5474  *
5475  *      This function may only be called from softirq context and interrupts
5476  *      should be enabled.
5477  *
5478  *      Return values (usually ignored):
5479  *      NET_RX_SUCCESS: no congestion
5480  *      NET_RX_DROP: packet was dropped
5481  */
5482 int netif_receive_skb_core(struct sk_buff *skb)
5483 {
5484         int ret;
5485
5486         rcu_read_lock();
5487         ret = __netif_receive_skb_one_core(skb, false);
5488         rcu_read_unlock();
5489
5490         return ret;
5491 }
5492 EXPORT_SYMBOL(netif_receive_skb_core);
5493
5494 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5495                                                   struct packet_type *pt_prev,
5496                                                   struct net_device *orig_dev)
5497 {
5498         struct sk_buff *skb, *next;
5499
5500         if (!pt_prev)
5501                 return;
5502         if (list_empty(head))
5503                 return;
5504         if (pt_prev->list_func != NULL)
5505                 INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5506                                    ip_list_rcv, head, pt_prev, orig_dev);
5507         else
5508                 list_for_each_entry_safe(skb, next, head, list) {
5509                         skb_list_del_init(skb);
5510                         pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5511                 }
5512 }
5513
5514 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5515 {
5516         /* Fast-path assumptions:
5517          * - There is no RX handler.
5518          * - Only one packet_type matches.
5519          * If either of these fails, we will end up doing some per-packet
5520          * processing in-line, then handling the 'last ptype' for the whole
5521          * sublist.  This can't cause out-of-order delivery to any single ptype,
5522          * because the 'last ptype' must be constant across the sublist, and all
5523          * other ptypes are handled per-packet.
5524          */
5525         /* Current (common) ptype of sublist */
5526         struct packet_type *pt_curr = NULL;
5527         /* Current (common) orig_dev of sublist */
5528         struct net_device *od_curr = NULL;
5529         struct list_head sublist;
5530         struct sk_buff *skb, *next;
5531
5532         INIT_LIST_HEAD(&sublist);
5533         list_for_each_entry_safe(skb, next, head, list) {
5534                 struct net_device *orig_dev = skb->dev;
5535                 struct packet_type *pt_prev = NULL;
5536
5537                 skb_list_del_init(skb);
5538                 __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5539                 if (!pt_prev)
5540                         continue;
5541                 if (pt_curr != pt_prev || od_curr != orig_dev) {
5542                         /* dispatch old sublist */
5543                         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5544                         /* start new sublist */
5545                         INIT_LIST_HEAD(&sublist);
5546                         pt_curr = pt_prev;
5547                         od_curr = orig_dev;
5548                 }
5549                 list_add_tail(&skb->list, &sublist);
5550         }
5551
5552         /* dispatch final sublist */
5553         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5554 }
5555
5556 static int __netif_receive_skb(struct sk_buff *skb)
5557 {
5558         int ret;
5559
5560         if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5561                 unsigned int noreclaim_flag;
5562
5563                 /*
5564                  * PFMEMALLOC skbs are special, they should
5565                  * - be delivered to SOCK_MEMALLOC sockets only
5566                  * - stay away from userspace
5567                  * - have bounded memory usage
5568                  *
5569                  * Use PF_MEMALLOC as this saves us from propagating the allocation
5570                  * context down to all allocation sites.
5571                  */
5572                 noreclaim_flag = memalloc_noreclaim_save();
5573                 ret = __netif_receive_skb_one_core(skb, true);
5574                 memalloc_noreclaim_restore(noreclaim_flag);
5575         } else
5576                 ret = __netif_receive_skb_one_core(skb, false);
5577
5578         return ret;
5579 }
5580
5581 static void __netif_receive_skb_list(struct list_head *head)
5582 {
5583         unsigned long noreclaim_flag = 0;
5584         struct sk_buff *skb, *next;
5585         bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5586
5587         list_for_each_entry_safe(skb, next, head, list) {
5588                 if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5589                         struct list_head sublist;
5590
5591                         /* Handle the previous sublist */
5592                         list_cut_before(&sublist, head, &skb->list);
5593                         if (!list_empty(&sublist))
5594                                 __netif_receive_skb_list_core(&sublist, pfmemalloc);
5595                         pfmemalloc = !pfmemalloc;
5596                         /* See comments in __netif_receive_skb */
5597                         if (pfmemalloc)
5598                                 noreclaim_flag = memalloc_noreclaim_save();
5599                         else
5600                                 memalloc_noreclaim_restore(noreclaim_flag);
5601                 }
5602         }
5603         /* Handle the remaining sublist */
5604         if (!list_empty(head))
5605                 __netif_receive_skb_list_core(head, pfmemalloc);
5606         /* Restore pflags */
5607         if (pfmemalloc)
5608                 memalloc_noreclaim_restore(noreclaim_flag);
5609 }
5610
5611 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5612 {
5613         struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5614         struct bpf_prog *new = xdp->prog;
5615         int ret = 0;
5616
5617         switch (xdp->command) {
5618         case XDP_SETUP_PROG:
5619                 rcu_assign_pointer(dev->xdp_prog, new);
5620                 if (old)
5621                         bpf_prog_put(old);
5622
5623                 if (old && !new) {
5624                         static_branch_dec(&generic_xdp_needed_key);
5625                 } else if (new && !old) {
5626                         static_branch_inc(&generic_xdp_needed_key);
5627                         dev_disable_lro(dev);
5628                         dev_disable_gro_hw(dev);
5629                 }
5630                 break;
5631
5632         default:
5633                 ret = -EINVAL;
5634                 break;
5635         }
5636
5637         return ret;
5638 }
5639
5640 static int netif_receive_skb_internal(struct sk_buff *skb)
5641 {
5642         int ret;
5643
5644         net_timestamp_check(netdev_tstamp_prequeue, skb);
5645
5646         if (skb_defer_rx_timestamp(skb))
5647                 return NET_RX_SUCCESS;
5648
5649         rcu_read_lock();
5650 #ifdef CONFIG_RPS
5651         if (static_branch_unlikely(&rps_needed)) {
5652                 struct rps_dev_flow voidflow, *rflow = &voidflow;
5653                 int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5654
5655                 if (cpu >= 0) {
5656                         ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5657                         rcu_read_unlock();
5658                         return ret;
5659                 }
5660         }
5661 #endif
5662         ret = __netif_receive_skb(skb);
5663         rcu_read_unlock();
5664         return ret;
5665 }
5666
5667 static void netif_receive_skb_list_internal(struct list_head *head)
5668 {
5669         struct sk_buff *skb, *next;
5670         struct list_head sublist;
5671
5672         INIT_LIST_HEAD(&sublist);
5673         list_for_each_entry_safe(skb, next, head, list) {
5674                 net_timestamp_check(netdev_tstamp_prequeue, skb);
5675                 skb_list_del_init(skb);
5676                 if (!skb_defer_rx_timestamp(skb))
5677                         list_add_tail(&skb->list, &sublist);
5678         }
5679         list_splice_init(&sublist, head);
5680
5681         rcu_read_lock();
5682 #ifdef CONFIG_RPS
5683         if (static_branch_unlikely(&rps_needed)) {
5684                 list_for_each_entry_safe(skb, next, head, list) {
5685                         struct rps_dev_flow voidflow, *rflow = &voidflow;
5686                         int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5687
5688                         if (cpu >= 0) {
5689                                 /* Will be handled, remove from list */
5690                                 skb_list_del_init(skb);
5691                                 enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5692                         }
5693                 }
5694         }
5695 #endif
5696         __netif_receive_skb_list(head);
5697         rcu_read_unlock();
5698 }
5699
5700 /**
5701  *      netif_receive_skb - process receive buffer from network
5702  *      @skb: buffer to process
5703  *
5704  *      netif_receive_skb() is the main receive data processing function.
5705  *      It always succeeds. The buffer may be dropped during processing
5706  *      for congestion control or by the protocol layers.
5707  *
5708  *      This function may only be called from softirq context and interrupts
5709  *      should be enabled.
5710  *
5711  *      Return values (usually ignored):
5712  *      NET_RX_SUCCESS: no congestion
5713  *      NET_RX_DROP: packet was dropped
5714  */
5715 int netif_receive_skb(struct sk_buff *skb)
5716 {
5717         int ret;
5718
5719         trace_netif_receive_skb_entry(skb);
5720
5721         ret = netif_receive_skb_internal(skb);
5722         trace_netif_receive_skb_exit(ret);
5723
5724         return ret;
5725 }
5726 EXPORT_SYMBOL(netif_receive_skb);
5727
5728 /**
5729  *      netif_receive_skb_list - process many receive buffers from network
5730  *      @head: list of skbs to process.
5731  *
5732  *      Since return value of netif_receive_skb() is normally ignored, and
5733  *      wouldn't be meaningful for a list, this function returns void.
5734  *
5735  *      This function may only be called from softirq context and interrupts
5736  *      should be enabled.
5737  */
5738 void netif_receive_skb_list(struct list_head *head)
5739 {
5740         struct sk_buff *skb;
5741
5742         if (list_empty(head))
5743                 return;
5744         if (trace_netif_receive_skb_list_entry_enabled()) {
5745                 list_for_each_entry(skb, head, list)
5746                         trace_netif_receive_skb_list_entry(skb);
5747         }
5748         netif_receive_skb_list_internal(head);
5749         trace_netif_receive_skb_list_exit(0);
5750 }
5751 EXPORT_SYMBOL(netif_receive_skb_list);
5752
5753 static DEFINE_PER_CPU(struct work_struct, flush_works);
5754
5755 /* Network device is going away, flush any packets still pending */
5756 static void flush_backlog(struct work_struct *work)
5757 {
5758         struct sk_buff *skb, *tmp;
5759         struct softnet_data *sd;
5760
5761         local_bh_disable();
5762         sd = this_cpu_ptr(&softnet_data);
5763
5764         local_irq_disable();
5765         rps_lock(sd);
5766         skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5767                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5768                         __skb_unlink(skb, &sd->input_pkt_queue);
5769                         dev_kfree_skb_irq(skb);
5770                         input_queue_head_incr(sd);
5771                 }
5772         }
5773         rps_unlock(sd);
5774         local_irq_enable();
5775
5776         skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5777                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5778                         __skb_unlink(skb, &sd->process_queue);
5779                         kfree_skb(skb);
5780                         input_queue_head_incr(sd);
5781                 }
5782         }
5783         local_bh_enable();
5784 }
5785
5786 static bool flush_required(int cpu)
5787 {
5788 #if IS_ENABLED(CONFIG_RPS)
5789         struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5790         bool do_flush;
5791
5792         local_irq_disable();
5793         rps_lock(sd);
5794
5795         /* as insertion into process_queue happens with the rps lock held,
5796          * process_queue access may race only with dequeue
5797          */
5798         do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5799                    !skb_queue_empty_lockless(&sd->process_queue);
5800         rps_unlock(sd);
5801         local_irq_enable();
5802
5803         return do_flush;
5804 #endif
5805         /* without RPS we can't safely check input_pkt_queue: during a
5806          * concurrent remote skb_queue_splice() we can detect as empty both
5807          * input_pkt_queue and process_queue even if the latter could end-up
5808          * containing a lot of packets.
5809          */
5810         return true;
5811 }
5812
5813 static void flush_all_backlogs(void)
5814 {
5815         static cpumask_t flush_cpus;
5816         unsigned int cpu;
5817
5818         /* since we are under rtnl lock protection we can use static data
5819          * for the cpumask and avoid allocating on stack the possibly
5820          * large mask
5821          */
5822         ASSERT_RTNL();
5823
5824         cpus_read_lock();
5825
5826         cpumask_clear(&flush_cpus);
5827         for_each_online_cpu(cpu) {
5828                 if (flush_required(cpu)) {
5829                         queue_work_on(cpu, system_highpri_wq,
5830                                       per_cpu_ptr(&flush_works, cpu));
5831                         cpumask_set_cpu(cpu, &flush_cpus);
5832                 }
5833         }
5834
5835         /* we can have in flight packet[s] on the cpus we are not flushing,
5836          * synchronize_net() in unregister_netdevice_many() will take care of
5837          * them
5838          */
5839         for_each_cpu(cpu, &flush_cpus)
5840                 flush_work(per_cpu_ptr(&flush_works, cpu));
5841
5842         cpus_read_unlock();
5843 }
5844
5845 /* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
5846 static void gro_normal_list(struct napi_struct *napi)
5847 {
5848         if (!napi->rx_count)
5849                 return;
5850         netif_receive_skb_list_internal(&napi->rx_list);
5851         INIT_LIST_HEAD(&napi->rx_list);
5852         napi->rx_count = 0;
5853 }
5854
5855 /* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
5856  * pass the whole batch up to the stack.
5857  */
5858 static void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, int segs)
5859 {
5860         list_add_tail(&skb->list, &napi->rx_list);
5861         napi->rx_count += segs;
5862         if (napi->rx_count >= gro_normal_batch)
5863                 gro_normal_list(napi);
5864 }
5865
5866 static void napi_gro_complete(struct napi_struct *napi, struct sk_buff *skb)
5867 {
5868         struct packet_offload *ptype;
5869         __be16 type = skb->protocol;
5870         struct list_head *head = &offload_base;
5871         int err = -ENOENT;
5872
5873         BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
5874
5875         if (NAPI_GRO_CB(skb)->count == 1) {
5876                 skb_shinfo(skb)->gso_size = 0;
5877                 goto out;
5878         }
5879
5880         rcu_read_lock();
5881         list_for_each_entry_rcu(ptype, head, list) {
5882                 if (ptype->type != type || !ptype->callbacks.gro_complete)
5883                         continue;
5884
5885                 err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
5886                                          ipv6_gro_complete, inet_gro_complete,
5887                                          skb, 0);
5888                 break;
5889         }
5890         rcu_read_unlock();
5891
5892         if (err) {
5893                 WARN_ON(&ptype->list == head);
5894                 kfree_skb(skb);
5895                 return;
5896         }
5897
5898 out:
5899         gro_normal_one(napi, skb, NAPI_GRO_CB(skb)->count);
5900 }
5901
5902 static void __napi_gro_flush_chain(struct napi_struct *napi, u32 index,
5903                                    bool flush_old)
5904 {
5905         struct list_head *head = &napi->gro_hash[index].list;
5906         struct sk_buff *skb, *p;
5907
5908         list_for_each_entry_safe_reverse(skb, p, head, list) {
5909                 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
5910                         return;
5911                 skb_list_del_init(skb);
5912                 napi_gro_complete(napi, skb);
5913                 napi->gro_hash[index].count--;
5914         }
5915
5916         if (!napi->gro_hash[index].count)
5917                 __clear_bit(index, &napi->gro_bitmask);
5918 }
5919
5920 /* napi->gro_hash[].list contains packets ordered by age.
5921  * youngest packets at the head of it.
5922  * Complete skbs in reverse order to reduce latencies.
5923  */
5924 void napi_gro_flush(struct napi_struct *napi, bool flush_old)
5925 {
5926         unsigned long bitmask = napi->gro_bitmask;
5927         unsigned int i, base = ~0U;
5928
5929         while ((i = ffs(bitmask)) != 0) {
5930                 bitmask >>= i;
5931                 base += i;
5932                 __napi_gro_flush_chain(napi, base, flush_old);
5933         }
5934 }
5935 EXPORT_SYMBOL(napi_gro_flush);
5936
5937 static void gro_list_prepare(const struct list_head *head,
5938                              const struct sk_buff *skb)
5939 {
5940         unsigned int maclen = skb->dev->hard_header_len;
5941         u32 hash = skb_get_hash_raw(skb);
5942         struct sk_buff *p;
5943
5944         list_for_each_entry(p, head, list) {
5945                 unsigned long diffs;
5946
5947                 NAPI_GRO_CB(p)->flush = 0;
5948
5949                 if (hash != skb_get_hash_raw(p)) {
5950                         NAPI_GRO_CB(p)->same_flow = 0;
5951                         continue;
5952                 }
5953
5954                 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
5955                 diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb);
5956                 if (skb_vlan_tag_present(p))
5957                         diffs |= skb_vlan_tag_get(p) ^ skb_vlan_tag_get(skb);
5958                 diffs |= skb_metadata_differs(p, skb);
5959                 if (maclen == ETH_HLEN)
5960                         diffs |= compare_ether_header(skb_mac_header(p),
5961                                                       skb_mac_header(skb));
5962                 else if (!diffs)
5963                         diffs = memcmp(skb_mac_header(p),
5964                                        skb_mac_header(skb),
5965                                        maclen);
5966
5967                 /* in most common scenarions 'slow_gro' is 0
5968                  * otherwise we are already on some slower paths
5969                  * either skip all the infrequent tests altogether or
5970                  * avoid trying too hard to skip each of them individually
5971                  */
5972                 if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) {
5973 #if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
5974                         struct tc_skb_ext *skb_ext;
5975                         struct tc_skb_ext *p_ext;
5976 #endif
5977
5978                         diffs |= p->sk != skb->sk;
5979                         diffs |= skb_metadata_dst_cmp(p, skb);
5980                         diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb);
5981
5982 #if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
5983                         skb_ext = skb_ext_find(skb, TC_SKB_EXT);
5984                         p_ext = skb_ext_find(p, TC_SKB_EXT);
5985
5986                         diffs |= (!!p_ext) ^ (!!skb_ext);
5987                         if (!diffs && unlikely(skb_ext))
5988                                 diffs |= p_ext->chain ^ skb_ext->chain;
5989 #endif
5990                 }
5991
5992                 NAPI_GRO_CB(p)->same_flow = !diffs;
5993         }
5994 }
5995
5996 static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
5997 {
5998         const struct skb_shared_info *pinfo = skb_shinfo(skb);
5999         const skb_frag_t *frag0 = &pinfo->frags[0];
6000
6001         NAPI_GRO_CB(skb)->data_offset = 0;
6002         NAPI_GRO_CB(skb)->frag0 = NULL;
6003         NAPI_GRO_CB(skb)->frag0_len = 0;
6004
6005         if (!skb_headlen(skb) && pinfo->nr_frags &&
6006             !PageHighMem(skb_frag_page(frag0)) &&
6007             (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) {
6008                 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
6009                 NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
6010                                                     skb_frag_size(frag0),
6011                                                     skb->end - skb->tail);
6012         }
6013 }
6014
6015 static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
6016 {
6017         struct skb_shared_info *pinfo = skb_shinfo(skb);
6018
6019         BUG_ON(skb->end - skb->tail < grow);
6020
6021         memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
6022
6023         skb->data_len -= grow;
6024         skb->tail += grow;
6025
6026         skb_frag_off_add(&pinfo->frags[0], grow);
6027         skb_frag_size_sub(&pinfo->frags[0], grow);
6028
6029         if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
6030                 skb_frag_unref(skb, 0);
6031                 memmove(pinfo->frags, pinfo->frags + 1,
6032                         --pinfo->nr_frags * sizeof(pinfo->frags[0]));
6033         }
6034 }
6035
6036 static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head)
6037 {
6038         struct sk_buff *oldest;
6039
6040         oldest = list_last_entry(head, struct sk_buff, list);
6041
6042         /* We are called with head length >= MAX_GRO_SKBS, so this is
6043          * impossible.
6044          */
6045         if (WARN_ON_ONCE(!oldest))
6046                 return;
6047
6048         /* Do not adjust napi->gro_hash[].count, caller is adding a new
6049          * SKB to the chain.
6050          */
6051         skb_list_del_init(oldest);
6052         napi_gro_complete(napi, oldest);
6053 }
6054
6055 static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
6056 {
6057         u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
6058         struct gro_list *gro_list = &napi->gro_hash[bucket];
6059         struct list_head *head = &offload_base;
6060         struct packet_offload *ptype;
6061         __be16 type = skb->protocol;
6062         struct sk_buff *pp = NULL;
6063         enum gro_result ret;
6064         int same_flow;
6065         int grow;
6066
6067         if (netif_elide_gro(skb->dev))
6068                 goto normal;
6069
6070         gro_list_prepare(&gro_list->list, skb);
6071
6072         rcu_read_lock();
6073         list_for_each_entry_rcu(ptype, head, list) {
6074                 if (ptype->type != type || !ptype->callbacks.gro_receive)
6075                         continue;
6076
6077                 skb_set_network_header(skb, skb_gro_offset(skb));
6078                 skb_reset_mac_len(skb);
6079                 NAPI_GRO_CB(skb)->same_flow = 0;
6080                 NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
6081                 NAPI_GRO_CB(skb)->free = 0;
6082                 NAPI_GRO_CB(skb)->encap_mark = 0;
6083                 NAPI_GRO_CB(skb)->recursion_counter = 0;
6084                 NAPI_GRO_CB(skb)->is_fou = 0;
6085                 NAPI_GRO_CB(skb)->is_atomic = 1;
6086                 NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
6087
6088                 /* Setup for GRO checksum validation */
6089                 switch (skb->ip_summed) {
6090                 case CHECKSUM_COMPLETE:
6091                         NAPI_GRO_CB(skb)->csum = skb->csum;
6092                         NAPI_GRO_CB(skb)->csum_valid = 1;
6093                         NAPI_GRO_CB(skb)->csum_cnt = 0;
6094                         break;
6095                 case CHECKSUM_UNNECESSARY:
6096                         NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
6097                         NAPI_GRO_CB(skb)->csum_valid = 0;
6098                         break;
6099                 default:
6100                         NAPI_GRO_CB(skb)->csum_cnt = 0;
6101                         NAPI_GRO_CB(skb)->csum_valid = 0;
6102                 }
6103
6104                 pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
6105                                         ipv6_gro_receive, inet_gro_receive,
6106                                         &gro_list->list, skb);
6107                 break;
6108         }
6109         rcu_read_unlock();
6110
6111         if (&ptype->list == head)
6112                 goto normal;
6113
6114         if (PTR_ERR(pp) == -EINPROGRESS) {
6115                 ret = GRO_CONSUMED;
6116                 goto ok;
6117         }
6118
6119         same_flow = NAPI_GRO_CB(skb)->same_flow;
6120         ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
6121
6122         if (pp) {
6123                 skb_list_del_init(pp);
6124                 napi_gro_complete(napi, pp);
6125                 gro_list->count--;
6126         }
6127
6128         if (same_flow)
6129                 goto ok;
6130
6131         if (NAPI_GRO_CB(skb)->flush)
6132                 goto normal;
6133
6134         if (unlikely(gro_list->count >= MAX_GRO_SKBS))
6135                 gro_flush_oldest(napi, &gro_list->list);
6136         else
6137                 gro_list->count++;
6138
6139         NAPI_GRO_CB(skb)->count = 1;
6140         NAPI_GRO_CB(skb)->age = jiffies;
6141         NAPI_GRO_CB(skb)->last = skb;
6142         skb_shinfo(skb)->gso_size = skb_gro_len(skb);
6143         list_add(&skb->list, &gro_list->list);
6144         ret = GRO_HELD;
6145
6146 pull:
6147         grow = skb_gro_offset(skb) - skb_headlen(skb);
6148         if (grow > 0)
6149                 gro_pull_from_frag0(skb, grow);
6150 ok:
6151         if (gro_list->count) {
6152                 if (!test_bit(bucket, &napi->gro_bitmask))
6153                         __set_bit(bucket, &napi->gro_bitmask);
6154         } else if (test_bit(bucket, &napi->gro_bitmask)) {
6155                 __clear_bit(bucket, &napi->gro_bitmask);
6156         }
6157
6158         return ret;
6159
6160 normal:
6161         ret = GRO_NORMAL;
6162         goto pull;
6163 }
6164
6165 struct packet_offload *gro_find_receive_by_type(__be16 type)
6166 {
6167         struct list_head *offload_head = &offload_base;
6168         struct packet_offload *ptype;
6169
6170         list_for_each_entry_rcu(ptype, offload_head, list) {
6171                 if (ptype->type != type || !ptype->callbacks.gro_receive)
6172                         continue;
6173                 return ptype;
6174         }
6175         return NULL;
6176 }
6177 EXPORT_SYMBOL(gro_find_receive_by_type);
6178
6179 struct packet_offload *gro_find_complete_by_type(__be16 type)
6180 {
6181         struct list_head *offload_head = &offload_base;
6182         struct packet_offload *ptype;
6183
6184         list_for_each_entry_rcu(ptype, offload_head, list) {
6185                 if (ptype->type != type || !ptype->callbacks.gro_complete)
6186                         continue;
6187                 return ptype;
6188         }
6189         return NULL;
6190 }
6191 EXPORT_SYMBOL(gro_find_complete_by_type);
6192
6193 static gro_result_t napi_skb_finish(struct napi_struct *napi,
6194                                     struct sk_buff *skb,
6195                                     gro_result_t ret)
6196 {
6197         switch (ret) {
6198         case GRO_NORMAL:
6199                 gro_normal_one(napi, skb, 1);
6200                 break;
6201
6202         case GRO_MERGED_FREE:
6203                 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
6204                         napi_skb_free_stolen_head(skb);
6205                 else if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
6206                         __kfree_skb(skb);
6207                 else
6208                         __kfree_skb_defer(skb);
6209                 break;
6210
6211         case GRO_HELD:
6212         case GRO_MERGED:
6213         case GRO_CONSUMED:
6214                 break;
6215         }
6216
6217         return ret;
6218 }
6219
6220 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
6221 {
6222         gro_result_t ret;
6223
6224         skb_mark_napi_id(skb, napi);
6225         trace_napi_gro_receive_entry(skb);
6226
6227         skb_gro_reset_offset(skb, 0);
6228
6229         ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb));
6230         trace_napi_gro_receive_exit(ret);
6231
6232         return ret;
6233 }
6234 EXPORT_SYMBOL(napi_gro_receive);
6235
6236 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
6237 {
6238         if (unlikely(skb->pfmemalloc)) {
6239                 consume_skb(skb);
6240                 return;
6241         }
6242         __skb_pull(skb, skb_headlen(skb));
6243         /* restore the reserve we had after netdev_alloc_skb_ip_align() */
6244         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
6245         __vlan_hwaccel_clear_tag(skb);
6246         skb->dev = napi->dev;
6247         skb->skb_iif = 0;
6248
6249         /* eth_type_trans() assumes pkt_type is PACKET_HOST */
6250         skb->pkt_type = PACKET_HOST;
6251
6252         skb->encapsulation = 0;
6253         skb_shinfo(skb)->gso_type = 0;
6254         skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
6255         if (unlikely(skb->slow_gro)) {
6256                 skb_orphan(skb);
6257                 skb_ext_reset(skb);
6258                 nf_reset_ct(skb);
6259                 skb->slow_gro = 0;
6260         }
6261
6262         napi->skb = skb;
6263 }
6264
6265 struct sk_buff *napi_get_frags(struct napi_struct *napi)
6266 {
6267         struct sk_buff *skb = napi->skb;
6268
6269         if (!skb) {
6270                 skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
6271                 if (skb) {
6272                         napi->skb = skb;
6273                         skb_mark_napi_id(skb, napi);
6274                 }
6275         }
6276         return skb;
6277 }
6278 EXPORT_SYMBOL(napi_get_frags);
6279
6280 static gro_result_t napi_frags_finish(struct napi_struct *napi,
6281                                       struct sk_buff *skb,
6282                                       gro_result_t ret)
6283 {
6284         switch (ret) {
6285         case GRO_NORMAL:
6286         case GRO_HELD:
6287                 __skb_push(skb, ETH_HLEN);
6288                 skb->protocol = eth_type_trans(skb, skb->dev);
6289                 if (ret == GRO_NORMAL)
6290                         gro_normal_one(napi, skb, 1);
6291                 break;
6292
6293         case GRO_MERGED_FREE:
6294                 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
6295                         napi_skb_free_stolen_head(skb);
6296                 else
6297                         napi_reuse_skb(napi, skb);
6298                 break;
6299
6300         case GRO_MERGED:
6301         case GRO_CONSUMED:
6302                 break;
6303         }
6304
6305         return ret;
6306 }
6307
6308 /* Upper GRO stack assumes network header starts at gro_offset=0
6309  * Drivers could call both napi_gro_frags() and napi_gro_receive()
6310  * We copy ethernet header into skb->data to have a common layout.
6311  */
6312 static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
6313 {
6314         struct sk_buff *skb = napi->skb;
6315         const struct ethhdr *eth;
6316         unsigned int hlen = sizeof(*eth);
6317
6318         napi->skb = NULL;
6319
6320         skb_reset_mac_header(skb);
6321         skb_gro_reset_offset(skb, hlen);
6322
6323         if (unlikely(skb_gro_header_hard(skb, hlen))) {
6324                 eth = skb_gro_header_slow(skb, hlen, 0);
6325                 if (unlikely(!eth)) {
6326                         net_warn_ratelimited("%s: dropping impossible skb from %s\n",
6327                                              __func__, napi->dev->name);
6328                         napi_reuse_skb(napi, skb);
6329                         return NULL;
6330                 }
6331         } else {
6332                 eth = (const struct ethhdr *)skb->data;
6333                 gro_pull_from_frag0(skb, hlen);
6334                 NAPI_GRO_CB(skb)->frag0 += hlen;
6335                 NAPI_GRO_CB(skb)->frag0_len -= hlen;
6336         }
6337         __skb_pull(skb, hlen);
6338
6339         /*
6340          * This works because the only protocols we care about don't require
6341          * special handling.
6342          * We'll fix it up properly in napi_frags_finish()
6343          */
6344         skb->protocol = eth->h_proto;
6345
6346         return skb;
6347 }
6348
6349 gro_result_t napi_gro_frags(struct napi_struct *napi)
6350 {
6351         gro_result_t ret;
6352         struct sk_buff *skb = napi_frags_skb(napi);
6353
6354         trace_napi_gro_frags_entry(skb);
6355
6356         ret = napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
6357         trace_napi_gro_frags_exit(ret);
6358
6359         return ret;
6360 }
6361 EXPORT_SYMBOL(napi_gro_frags);
6362
6363 /* Compute the checksum from gro_offset and return the folded value
6364  * after adding in any pseudo checksum.
6365  */
6366 __sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
6367 {
6368         __wsum wsum;
6369         __sum16 sum;
6370
6371         wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
6372
6373         /* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
6374         sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
6375         /* See comments in __skb_checksum_complete(). */
6376         if (likely(!sum)) {
6377                 if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
6378                     !skb->csum_complete_sw)
6379                         netdev_rx_csum_fault(skb->dev, skb);
6380         }
6381
6382         NAPI_GRO_CB(skb)->csum = wsum;
6383         NAPI_GRO_CB(skb)->csum_valid = 1;
6384
6385         return sum;
6386 }
6387 EXPORT_SYMBOL(__skb_gro_checksum_complete);
6388
6389 static void net_rps_send_ipi(struct softnet_data *remsd)
6390 {
6391 #ifdef CONFIG_RPS
6392         while (remsd) {
6393                 struct softnet_data *next = remsd->rps_ipi_next;
6394
6395                 if (cpu_online(remsd->cpu))
6396                         smp_call_function_single_async(remsd->cpu, &remsd->csd);
6397                 remsd = next;
6398         }
6399 #endif
6400 }
6401
6402 /*
6403  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
6404  * Note: called with local irq disabled, but exits with local irq enabled.
6405  */
6406 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
6407 {
6408 #ifdef CONFIG_RPS
6409         struct softnet_data *remsd = sd->rps_ipi_list;
6410
6411         if (remsd) {
6412                 sd->rps_ipi_list = NULL;
6413
6414                 local_irq_enable();
6415
6416                 /* Send pending IPI's to kick RPS processing on remote cpus. */
6417                 net_rps_send_ipi(remsd);
6418         } else
6419 #endif
6420                 local_irq_enable();
6421 }
6422
6423 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
6424 {
6425 #ifdef CONFIG_RPS
6426         return sd->rps_ipi_list != NULL;
6427 #else
6428         return false;
6429 #endif
6430 }
6431
6432 static int process_backlog(struct napi_struct *napi, int quota)
6433 {
6434         struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
6435         bool again = true;
6436         int work = 0;
6437
6438         /* Check if we have pending ipi, its better to send them now,
6439          * not waiting net_rx_action() end.
6440          */
6441         if (sd_has_rps_ipi_waiting(sd)) {
6442                 local_irq_disable();
6443                 net_rps_action_and_irq_enable(sd);
6444         }
6445
6446         napi->weight = dev_rx_weight;
6447         while (again) {
6448                 struct sk_buff *skb;
6449
6450                 while ((skb = __skb_dequeue(&sd->process_queue))) {
6451                         rcu_read_lock();
6452                         __netif_receive_skb(skb);
6453                         rcu_read_unlock();
6454                         input_queue_head_incr(sd);
6455                         if (++work >= quota)
6456                                 return work;
6457
6458                 }
6459
6460                 local_irq_disable();
6461                 rps_lock(sd);
6462                 if (skb_queue_empty(&sd->input_pkt_queue)) {
6463                         /*
6464                          * Inline a custom version of __napi_complete().
6465                          * only current cpu owns and manipulates this napi,
6466                          * and NAPI_STATE_SCHED is the only possible flag set
6467                          * on backlog.
6468                          * We can use a plain write instead of clear_bit(),
6469                          * and we dont need an smp_mb() memory barrier.
6470                          */
6471                         napi->state = 0;
6472                         again = false;
6473                 } else {
6474                         skb_queue_splice_tail_init(&sd->input_pkt_queue,
6475                                                    &sd->process_queue);
6476                 }
6477                 rps_unlock(sd);
6478                 local_irq_enable();
6479         }
6480
6481         return work;
6482 }
6483
6484 /**
6485  * __napi_schedule - schedule for receive
6486  * @n: entry to schedule
6487  *
6488  * The entry's receive function will be scheduled to run.
6489  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
6490  */
6491 void __napi_schedule(struct napi_struct *n)
6492 {
6493         unsigned long flags;
6494
6495         local_irq_save(flags);
6496         ____napi_schedule(this_cpu_ptr(&softnet_data), n);
6497         local_irq_restore(flags);
6498 }
6499 EXPORT_SYMBOL(__napi_schedule);
6500
6501 /**
6502  *      napi_schedule_prep - check if napi can be scheduled
6503  *      @n: napi context
6504  *
6505  * Test if NAPI routine is already running, and if not mark
6506  * it as running.  This is used as a condition variable to
6507  * insure only one NAPI poll instance runs.  We also make
6508  * sure there is no pending NAPI disable.
6509  */
6510 bool napi_schedule_prep(struct napi_struct *n)
6511 {
6512         unsigned long val, new;
6513
6514         do {
6515                 val = READ_ONCE(n->state);
6516                 if (unlikely(val & NAPIF_STATE_DISABLE))
6517                         return false;
6518                 new = val | NAPIF_STATE_SCHED;
6519
6520                 /* Sets STATE_MISSED bit if STATE_SCHED was already set
6521                  * This was suggested by Alexander Duyck, as compiler
6522                  * emits better code than :
6523                  * if (val & NAPIF_STATE_SCHED)
6524                  *     new |= NAPIF_STATE_MISSED;
6525                  */
6526                 new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6527                                                    NAPIF_STATE_MISSED;
6528         } while (cmpxchg(&n->state, val, new) != val);
6529
6530         return !(val & NAPIF_STATE_SCHED);
6531 }
6532 EXPORT_SYMBOL(napi_schedule_prep);
6533
6534 /**
6535  * __napi_schedule_irqoff - schedule for receive
6536  * @n: entry to schedule
6537  *
6538  * Variant of __napi_schedule() assuming hard irqs are masked.
6539  *
6540  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6541  * because the interrupt disabled assumption might not be true
6542  * due to force-threaded interrupts and spinlock substitution.
6543  */
6544 void __napi_schedule_irqoff(struct napi_struct *n)
6545 {
6546         if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6547                 ____napi_schedule(this_cpu_ptr(&softnet_data), n);
6548         else
6549                 __napi_schedule(n);
6550 }
6551 EXPORT_SYMBOL(__napi_schedule_irqoff);
6552
6553 bool napi_complete_done(struct napi_struct *n, int work_done)
6554 {
6555         unsigned long flags, val, new, timeout = 0;
6556         bool ret = true;
6557
6558         /*
6559          * 1) Don't let napi dequeue from the cpu poll list
6560          *    just in case its running on a different cpu.
6561          * 2) If we are busy polling, do nothing here, we have
6562          *    the guarantee we will be called later.
6563          */
6564         if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6565                                  NAPIF_STATE_IN_BUSY_POLL)))
6566                 return false;
6567
6568         if (work_done) {
6569                 if (n->gro_bitmask)
6570                         timeout = READ_ONCE(n->dev->gro_flush_timeout);
6571                 n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6572         }
6573         if (n->defer_hard_irqs_count > 0) {
6574                 n->defer_hard_irqs_count--;
6575                 timeout = READ_ONCE(n->dev->gro_flush_timeout);
6576                 if (timeout)
6577                         ret = false;
6578         }
6579         if (n->gro_bitmask) {
6580                 /* When the NAPI instance uses a timeout and keeps postponing
6581                  * it, we need to bound somehow the time packets are kept in
6582                  * the GRO layer
6583                  */
6584                 napi_gro_flush(n, !!timeout);
6585         }
6586
6587         gro_normal_list(n);
6588
6589         if (unlikely(!list_empty(&n->poll_list))) {
6590                 /* If n->poll_list is not empty, we need to mask irqs */
6591                 local_irq_save(flags);
6592                 list_del_init(&n->poll_list);
6593                 local_irq_restore(flags);
6594         }
6595
6596         do {
6597                 val = READ_ONCE(n->state);
6598
6599                 WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6600
6601                 new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6602                               NAPIF_STATE_SCHED_THREADED |
6603                               NAPIF_STATE_PREFER_BUSY_POLL);
6604
6605                 /* If STATE_MISSED was set, leave STATE_SCHED set,
6606                  * because we will call napi->poll() one more time.
6607                  * This C code was suggested by Alexander Duyck to help gcc.
6608                  */
6609                 new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6610                                                     NAPIF_STATE_SCHED;
6611         } while (cmpxchg(&n->state, val, new) != val);
6612
6613         if (unlikely(val & NAPIF_STATE_MISSED)) {
6614                 __napi_schedule(n);
6615                 return false;
6616         }
6617
6618         if (timeout)
6619                 hrtimer_start(&n->timer, ns_to_ktime(timeout),
6620                               HRTIMER_MODE_REL_PINNED);
6621         return ret;
6622 }
6623 EXPORT_SYMBOL(napi_complete_done);
6624
6625 /* must be called under rcu_read_lock(), as we dont take a reference */
6626 static struct napi_struct *napi_by_id(unsigned int napi_id)
6627 {
6628         unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6629         struct napi_struct *napi;
6630
6631         hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6632                 if (napi->napi_id == napi_id)
6633                         return napi;
6634
6635         return NULL;
6636 }
6637
6638 #if defined(CONFIG_NET_RX_BUSY_POLL)
6639
6640 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6641 {
6642         if (!skip_schedule) {
6643                 gro_normal_list(napi);
6644                 __napi_schedule(napi);
6645                 return;
6646         }
6647
6648         if (napi->gro_bitmask) {
6649                 /* flush too old packets
6650                  * If HZ < 1000, flush all packets.
6651                  */
6652                 napi_gro_flush(napi, HZ >= 1000);
6653         }
6654
6655         gro_normal_list(napi);
6656         clear_bit(NAPI_STATE_SCHED, &napi->state);
6657 }
6658
6659 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6660                            u16 budget)
6661 {
6662         bool skip_schedule = false;
6663         unsigned long timeout;
6664         int rc;
6665
6666         /* Busy polling means there is a high chance device driver hard irq
6667          * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6668          * set in napi_schedule_prep().
6669          * Since we are about to call napi->poll() once more, we can safely
6670          * clear NAPI_STATE_MISSED.
6671          *
6672          * Note: x86 could use a single "lock and ..." instruction
6673          * to perform these two clear_bit()
6674          */
6675         clear_bit(NAPI_STATE_MISSED, &napi->state);
6676         clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6677
6678         local_bh_disable();
6679
6680         if (prefer_busy_poll) {
6681                 napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6682                 timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6683                 if (napi->defer_hard_irqs_count && timeout) {
6684                         hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6685                         skip_schedule = true;
6686                 }
6687         }
6688
6689         /* All we really want here is to re-enable device interrupts.
6690          * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6691          */
6692         rc = napi->poll(napi, budget);
6693         /* We can't gro_normal_list() here, because napi->poll() might have
6694          * rearmed the napi (napi_complete_done()) in which case it could
6695          * already be running on another CPU.
6696          */
6697         trace_napi_poll(napi, rc, budget);
6698         netpoll_poll_unlock(have_poll_lock);
6699         if (rc == budget)
6700                 __busy_poll_stop(napi, skip_schedule);
6701         local_bh_enable();
6702 }
6703
6704 void napi_busy_loop(unsigned int napi_id,
6705                     bool (*loop_end)(void *, unsigned long),
6706                     void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6707 {
6708         unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6709         int (*napi_poll)(struct napi_struct *napi, int budget);
6710         void *have_poll_lock = NULL;
6711         struct napi_struct *napi;
6712
6713 restart:
6714         napi_poll = NULL;
6715
6716         rcu_read_lock();
6717
6718         napi = napi_by_id(napi_id);
6719         if (!napi)
6720                 goto out;
6721
6722         preempt_disable();
6723         for (;;) {
6724                 int work = 0;
6725
6726                 local_bh_disable();
6727                 if (!napi_poll) {
6728                         unsigned long val = READ_ONCE(napi->state);
6729
6730                         /* If multiple threads are competing for this napi,
6731                          * we avoid dirtying napi->state as much as we can.
6732                          */
6733                         if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6734                                    NAPIF_STATE_IN_BUSY_POLL)) {
6735                                 if (prefer_busy_poll)
6736                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6737                                 goto count;
6738                         }
6739                         if (cmpxchg(&napi->state, val,
6740                                     val | NAPIF_STATE_IN_BUSY_POLL |
6741                                           NAPIF_STATE_SCHED) != val) {
6742                                 if (prefer_busy_poll)
6743                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6744                                 goto count;
6745                         }
6746                         have_poll_lock = netpoll_poll_lock(napi);
6747                         napi_poll = napi->poll;
6748                 }
6749                 work = napi_poll(napi, budget);
6750                 trace_napi_poll(napi, work, budget);
6751                 gro_normal_list(napi);
6752 count:
6753                 if (work > 0)
6754                         __NET_ADD_STATS(dev_net(napi->dev),
6755                                         LINUX_MIB_BUSYPOLLRXPACKETS, work);
6756                 local_bh_enable();
6757
6758                 if (!loop_end || loop_end(loop_end_arg, start_time))
6759                         break;
6760
6761                 if (unlikely(need_resched())) {
6762                         if (napi_poll)
6763                                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6764                         preempt_enable();
6765                         rcu_read_unlock();
6766                         cond_resched();
6767                         if (loop_end(loop_end_arg, start_time))
6768                                 return;
6769                         goto restart;
6770                 }
6771                 cpu_relax();
6772         }
6773         if (napi_poll)
6774                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6775         preempt_enable();
6776 out:
6777         rcu_read_unlock();
6778 }
6779 EXPORT_SYMBOL(napi_busy_loop);
6780
6781 #endif /* CONFIG_NET_RX_BUSY_POLL */
6782
6783 static void napi_hash_add(struct napi_struct *napi)
6784 {
6785         if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6786                 return;
6787
6788         spin_lock(&napi_hash_lock);
6789
6790         /* 0..NR_CPUS range is reserved for sender_cpu use */
6791         do {
6792                 if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6793                         napi_gen_id = MIN_NAPI_ID;
6794         } while (napi_by_id(napi_gen_id));
6795         napi->napi_id = napi_gen_id;
6796
6797         hlist_add_head_rcu(&napi->napi_hash_node,
6798                            &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6799
6800         spin_unlock(&napi_hash_lock);
6801 }
6802
6803 /* Warning : caller is responsible to make sure rcu grace period
6804  * is respected before freeing memory containing @napi
6805  */
6806 static void napi_hash_del(struct napi_struct *napi)
6807 {
6808         spin_lock(&napi_hash_lock);
6809
6810         hlist_del_init_rcu(&napi->napi_hash_node);
6811
6812         spin_unlock(&napi_hash_lock);
6813 }
6814
6815 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6816 {
6817         struct napi_struct *napi;
6818
6819         napi = container_of(timer, struct napi_struct, timer);
6820
6821         /* Note : we use a relaxed variant of napi_schedule_prep() not setting
6822          * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6823          */
6824         if (!napi_disable_pending(napi) &&
6825             !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6826                 clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6827                 __napi_schedule_irqoff(napi);
6828         }
6829
6830         return HRTIMER_NORESTART;
6831 }
6832
6833 static void init_gro_hash(struct napi_struct *napi)
6834 {
6835         int i;
6836
6837         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6838                 INIT_LIST_HEAD(&napi->gro_hash[i].list);
6839                 napi->gro_hash[i].count = 0;
6840         }
6841         napi->gro_bitmask = 0;
6842 }
6843
6844 int dev_set_threaded(struct net_device *dev, bool threaded)
6845 {
6846         struct napi_struct *napi;
6847         int err = 0;
6848
6849         if (dev->threaded == threaded)
6850                 return 0;
6851
6852         if (threaded) {
6853                 list_for_each_entry(napi, &dev->napi_list, dev_list) {
6854                         if (!napi->thread) {
6855                                 err = napi_kthread_create(napi);
6856                                 if (err) {
6857                                         threaded = false;
6858                                         break;
6859                                 }
6860                         }
6861                 }
6862         }
6863
6864         dev->threaded = threaded;
6865
6866         /* Make sure kthread is created before THREADED bit
6867          * is set.
6868          */
6869         smp_mb__before_atomic();
6870
6871         /* Setting/unsetting threaded mode on a napi might not immediately
6872          * take effect, if the current napi instance is actively being
6873          * polled. In this case, the switch between threaded mode and
6874          * softirq mode will happen in the next round of napi_schedule().
6875          * This should not cause hiccups/stalls to the live traffic.
6876          */
6877         list_for_each_entry(napi, &dev->napi_list, dev_list) {
6878                 if (threaded)
6879                         set_bit(NAPI_STATE_THREADED, &napi->state);
6880                 else
6881                         clear_bit(NAPI_STATE_THREADED, &napi->state);
6882         }
6883
6884         return err;
6885 }
6886 EXPORT_SYMBOL(dev_set_threaded);
6887
6888 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
6889                     int (*poll)(struct napi_struct *, int), int weight)
6890 {
6891         if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6892                 return;
6893
6894         INIT_LIST_HEAD(&napi->poll_list);
6895         INIT_HLIST_NODE(&napi->napi_hash_node);
6896         hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6897         napi->timer.function = napi_watchdog;
6898         init_gro_hash(napi);
6899         napi->skb = NULL;
6900         INIT_LIST_HEAD(&napi->rx_list);
6901         napi->rx_count = 0;
6902         napi->poll = poll;
6903         if (weight > NAPI_POLL_WEIGHT)
6904                 netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6905                                 weight);
6906         napi->weight = weight;
6907         napi->dev = dev;
6908 #ifdef CONFIG_NETPOLL
6909         napi->poll_owner = -1;
6910 #endif
6911         set_bit(NAPI_STATE_SCHED, &napi->state);
6912         set_bit(NAPI_STATE_NPSVC, &napi->state);
6913         list_add_rcu(&napi->dev_list, &dev->napi_list);
6914         napi_hash_add(napi);
6915         /* Create kthread for this napi if dev->threaded is set.
6916          * Clear dev->threaded if kthread creation failed so that
6917          * threaded mode will not be enabled in napi_enable().
6918          */
6919         if (dev->threaded && napi_kthread_create(napi))
6920                 dev->threaded = 0;
6921 }
6922 EXPORT_SYMBOL(netif_napi_add);
6923
6924 void napi_disable(struct napi_struct *n)
6925 {
6926         unsigned long val, new;
6927
6928         might_sleep();
6929         set_bit(NAPI_STATE_DISABLE, &n->state);
6930
6931         do {
6932                 val = READ_ONCE(n->state);
6933                 if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6934                         usleep_range(20, 200);
6935                         continue;
6936                 }
6937
6938                 new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6939                 new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6940         } while (cmpxchg(&n->state, val, new) != val);
6941
6942         hrtimer_cancel(&n->timer);
6943
6944         clear_bit(NAPI_STATE_DISABLE, &n->state);
6945 }
6946 EXPORT_SYMBOL(napi_disable);
6947
6948 /**
6949  *      napi_enable - enable NAPI scheduling
6950  *      @n: NAPI context
6951  *
6952  * Resume NAPI from being scheduled on this context.
6953  * Must be paired with napi_disable.
6954  */
6955 void napi_enable(struct napi_struct *n)
6956 {
6957         unsigned long val, new;
6958
6959         do {
6960                 val = READ_ONCE(n->state);
6961                 BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6962
6963                 new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6964                 if (n->dev->threaded && n->thread)
6965                         new |= NAPIF_STATE_THREADED;
6966         } while (cmpxchg(&n->state, val, new) != val);
6967 }
6968 EXPORT_SYMBOL(napi_enable);
6969
6970 static void flush_gro_hash(struct napi_struct *napi)
6971 {
6972         int i;
6973
6974         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6975                 struct sk_buff *skb, *n;
6976
6977                 list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6978                         kfree_skb(skb);
6979                 napi->gro_hash[i].count = 0;
6980         }
6981 }
6982
6983 /* Must be called in process context */
6984 void __netif_napi_del(struct napi_struct *napi)
6985 {
6986         if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6987                 return;
6988
6989         napi_hash_del(napi);
6990         list_del_rcu(&napi->dev_list);
6991         napi_free_frags(napi);
6992
6993         flush_gro_hash(napi);
6994         napi->gro_bitmask = 0;
6995
6996         if (napi->thread) {
6997                 kthread_stop(napi->thread);
6998                 napi->thread = NULL;
6999         }
7000 }
7001 EXPORT_SYMBOL(__netif_napi_del);
7002
7003 static int __napi_poll(struct napi_struct *n, bool *repoll)
7004 {
7005         int work, weight;
7006
7007         weight = n->weight;
7008
7009         /* This NAPI_STATE_SCHED test is for avoiding a race
7010          * with netpoll's poll_napi().  Only the entity which
7011          * obtains the lock and sees NAPI_STATE_SCHED set will
7012          * actually make the ->poll() call.  Therefore we avoid
7013          * accidentally calling ->poll() when NAPI is not scheduled.
7014          */
7015         work = 0;
7016         if (test_bit(NAPI_STATE_SCHED, &n->state)) {
7017                 work = n->poll(n, weight);
7018                 trace_napi_poll(n, work, weight);
7019         }
7020
7021         if (unlikely(work > weight))
7022                 netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
7023                                 n->poll, work, weight);
7024
7025         if (likely(work < weight))
7026                 return work;
7027
7028         /* Drivers must not modify the NAPI state if they
7029          * consume the entire weight.  In such cases this code
7030          * still "owns" the NAPI instance and therefore can
7031          * move the instance around on the list at-will.
7032          */
7033         if (unlikely(napi_disable_pending(n))) {
7034                 napi_complete(n);
7035                 return work;
7036         }
7037
7038         /* The NAPI context has more processing work, but busy-polling
7039          * is preferred. Exit early.
7040          */
7041         if (napi_prefer_busy_poll(n)) {
7042                 if (napi_complete_done(n, work)) {
7043                         /* If timeout is not set, we need to make sure
7044                          * that the NAPI is re-scheduled.
7045                          */
7046                         napi_schedule(n);
7047                 }
7048                 return work;
7049         }
7050
7051         if (n->gro_bitmask) {
7052                 /* flush too old packets
7053                  * If HZ < 1000, flush all packets.
7054                  */
7055                 napi_gro_flush(n, HZ >= 1000);
7056         }
7057
7058         gro_normal_list(n);
7059
7060         /* Some drivers may have called napi_schedule
7061          * prior to exhausting their budget.
7062          */
7063         if (unlikely(!list_empty(&n->poll_list))) {
7064                 pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
7065                              n->dev ? n->dev->name : "backlog");
7066                 return work;
7067         }
7068
7069         *repoll = true;
7070
7071         return work;
7072 }
7073
7074 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
7075 {
7076         bool do_repoll = false;
7077         void *have;
7078         int work;
7079
7080         list_del_init(&n->poll_list);
7081
7082         have = netpoll_poll_lock(n);
7083
7084         work = __napi_poll(n, &do_repoll);
7085
7086         if (do_repoll)
7087                 list_add_tail(&n->poll_list, repoll);
7088
7089         netpoll_poll_unlock(have);
7090
7091         return work;
7092 }
7093
7094 static int napi_thread_wait(struct napi_struct *napi)
7095 {
7096         bool woken = false;
7097
7098         set_current_state(TASK_INTERRUPTIBLE);
7099
7100         while (!kthread_should_stop()) {
7101                 /* Testing SCHED_THREADED bit here to make sure the current
7102                  * kthread owns this napi and could poll on this napi.
7103                  * Testing SCHED bit is not enough because SCHED bit might be
7104                  * set by some other busy poll thread or by napi_disable().
7105                  */
7106                 if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
7107                         WARN_ON(!list_empty(&napi->poll_list));
7108                         __set_current_state(TASK_RUNNING);
7109                         return 0;
7110                 }
7111
7112                 schedule();
7113                 /* woken being true indicates this thread owns this napi. */
7114                 woken = true;
7115                 set_current_state(TASK_INTERRUPTIBLE);
7116         }
7117         __set_current_state(TASK_RUNNING);
7118
7119         return -1;
7120 }
7121
7122 static int napi_threaded_poll(void *data)
7123 {
7124         struct napi_struct *napi = data;
7125         void *have;
7126
7127         while (!napi_thread_wait(napi)) {
7128                 for (;;) {
7129                         bool repoll = false;
7130
7131                         local_bh_disable();
7132
7133                         have = netpoll_poll_lock(napi);
7134                         __napi_poll(napi, &repoll);
7135                         netpoll_poll_unlock(have);
7136
7137                         local_bh_enable();
7138
7139                         if (!repoll)
7140                                 break;
7141
7142                         cond_resched();
7143                 }
7144         }
7145         return 0;
7146 }
7147
7148 static __latent_entropy void net_rx_action(struct softirq_action *h)
7149 {
7150         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
7151         unsigned long time_limit = jiffies +
7152                 usecs_to_jiffies(netdev_budget_usecs);
7153         int budget = netdev_budget;
7154         LIST_HEAD(list);
7155         LIST_HEAD(repoll);
7156
7157         local_irq_disable();
7158         list_splice_init(&sd->poll_list, &list);
7159         local_irq_enable();
7160
7161         for (;;) {
7162                 struct napi_struct *n;
7163
7164                 if (list_empty(&list)) {
7165                         if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
7166                                 return;
7167                         break;
7168                 }
7169
7170                 n = list_first_entry(&list, struct napi_struct, poll_list);
7171                 budget -= napi_poll(n, &repoll);
7172
7173                 /* If softirq window is exhausted then punt.
7174                  * Allow this to run for 2 jiffies since which will allow
7175                  * an average latency of 1.5/HZ.
7176                  */
7177                 if (unlikely(budget <= 0 ||
7178                              time_after_eq(jiffies, time_limit))) {
7179                         sd->time_squeeze++;
7180                         break;
7181                 }
7182         }
7183
7184         local_irq_disable();
7185
7186         list_splice_tail_init(&sd->poll_list, &list);
7187         list_splice_tail(&repoll, &list);
7188         list_splice(&list, &sd->poll_list);
7189         if (!list_empty(&sd->poll_list))
7190                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
7191
7192         net_rps_action_and_irq_enable(sd);
7193 }
7194
7195 struct netdev_adjacent {
7196         struct net_device *dev;
7197
7198         /* upper master flag, there can only be one master device per list */
7199         bool master;
7200
7201         /* lookup ignore flag */
7202         bool ignore;
7203
7204         /* counter for the number of times this device was added to us */
7205         u16 ref_nr;
7206
7207         /* private field for the users */
7208         void *private;
7209
7210         struct list_head list;
7211         struct rcu_head rcu;
7212 };
7213
7214 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
7215                                                  struct list_head *adj_list)
7216 {
7217         struct netdev_adjacent *adj;
7218
7219         list_for_each_entry(adj, adj_list, list) {
7220                 if (adj->dev == adj_dev)
7221                         return adj;
7222         }
7223         return NULL;
7224 }
7225
7226 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
7227                                     struct netdev_nested_priv *priv)
7228 {
7229         struct net_device *dev = (struct net_device *)priv->data;
7230
7231         return upper_dev == dev;
7232 }
7233
7234 /**
7235  * netdev_has_upper_dev - Check if device is linked to an upper device
7236  * @dev: device
7237  * @upper_dev: upper device to check
7238  *
7239  * Find out if a device is linked to specified upper device and return true
7240  * in case it is. Note that this checks only immediate upper device,
7241  * not through a complete stack of devices. The caller must hold the RTNL lock.
7242  */
7243 bool netdev_has_upper_dev(struct net_device *dev,
7244                           struct net_device *upper_dev)
7245 {
7246         struct netdev_nested_priv priv = {
7247                 .data = (void *)upper_dev,
7248         };
7249
7250         ASSERT_RTNL();
7251
7252         return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
7253                                              &priv);
7254 }
7255 EXPORT_SYMBOL(netdev_has_upper_dev);
7256
7257 /**
7258  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
7259  * @dev: device
7260  * @upper_dev: upper device to check
7261  *
7262  * Find out if a device is linked to specified upper device and return true
7263  * in case it is. Note that this checks the entire upper device chain.
7264  * The caller must hold rcu lock.
7265  */
7266
7267 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
7268                                   struct net_device *upper_dev)
7269 {
7270         struct netdev_nested_priv priv = {
7271                 .data = (void *)upper_dev,
7272         };
7273
7274         return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
7275                                                &priv);
7276 }
7277 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
7278
7279 /**
7280  * netdev_has_any_upper_dev - Check if device is linked to some device
7281  * @dev: device
7282  *
7283  * Find out if a device is linked to an upper device and return true in case
7284  * it is. The caller must hold the RTNL lock.
7285  */
7286 bool netdev_has_any_upper_dev(struct net_device *dev)
7287 {
7288         ASSERT_RTNL();
7289
7290         return !list_empty(&dev->adj_list.upper);
7291 }
7292 EXPORT_SYMBOL(netdev_has_any_upper_dev);
7293
7294 /**
7295  * netdev_master_upper_dev_get - Get master upper device
7296  * @dev: device
7297  *
7298  * Find a master upper device and return pointer to it or NULL in case
7299  * it's not there. The caller must hold the RTNL lock.
7300  */
7301 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
7302 {
7303         struct netdev_adjacent *upper;
7304
7305         ASSERT_RTNL();
7306
7307         if (list_empty(&dev->adj_list.upper))
7308                 return NULL;
7309
7310         upper = list_first_entry(&dev->adj_list.upper,
7311                                  struct netdev_adjacent, list);
7312         if (likely(upper->master))
7313                 return upper->dev;
7314         return NULL;
7315 }
7316 EXPORT_SYMBOL(netdev_master_upper_dev_get);
7317
7318 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
7319 {
7320         struct netdev_adjacent *upper;
7321
7322         ASSERT_RTNL();
7323
7324         if (list_empty(&dev->adj_list.upper))
7325                 return NULL;
7326
7327         upper = list_first_entry(&dev->adj_list.upper,
7328                                  struct netdev_adjacent, list);
7329         if (likely(upper->master) && !upper->ignore)
7330                 return upper->dev;
7331         return NULL;
7332 }
7333
7334 /**
7335  * netdev_has_any_lower_dev - Check if device is linked to some device
7336  * @dev: device
7337  *
7338  * Find out if a device is linked to a lower device and return true in case
7339  * it is. The caller must hold the RTNL lock.
7340  */
7341 static bool netdev_has_any_lower_dev(struct net_device *dev)
7342 {
7343         ASSERT_RTNL();
7344
7345         return !list_empty(&dev->adj_list.lower);
7346 }
7347
7348 void *netdev_adjacent_get_private(struct list_head *adj_list)
7349 {
7350         struct netdev_adjacent *adj;
7351
7352         adj = list_entry(adj_list, struct netdev_adjacent, list);
7353
7354         return adj->private;
7355 }
7356 EXPORT_SYMBOL(netdev_adjacent_get_private);
7357
7358 /**
7359  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
7360  * @dev: device
7361  * @iter: list_head ** of the current position
7362  *
7363  * Gets the next device from the dev's upper list, starting from iter
7364  * position. The caller must hold RCU read lock.
7365  */
7366 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
7367                                                  struct list_head **iter)
7368 {
7369         struct netdev_adjacent *upper;
7370
7371         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
7372
7373         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7374
7375         if (&upper->list == &dev->adj_list.upper)
7376                 return NULL;
7377
7378         *iter = &upper->list;
7379
7380         return upper->dev;
7381 }
7382 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
7383
7384 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
7385                                                   struct list_head **iter,
7386                                                   bool *ignore)
7387 {
7388         struct netdev_adjacent *upper;
7389
7390         upper = list_entry((*iter)->next, struct netdev_adjacent, list);
7391
7392         if (&upper->list == &dev->adj_list.upper)
7393                 return NULL;
7394
7395         *iter = &upper->list;
7396         *ignore = upper->ignore;
7397
7398         return upper->dev;
7399 }
7400
7401 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
7402                                                     struct list_head **iter)
7403 {
7404         struct netdev_adjacent *upper;
7405
7406         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
7407
7408         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7409
7410         if (&upper->list == &dev->adj_list.upper)
7411                 return NULL;
7412
7413         *iter = &upper->list;
7414
7415         return upper->dev;
7416 }
7417
7418 static int __netdev_walk_all_upper_dev(struct net_device *dev,
7419                                        int (*fn)(struct net_device *dev,
7420                                          struct netdev_nested_priv *priv),
7421                                        struct netdev_nested_priv *priv)
7422 {
7423         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7424         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7425         int ret, cur = 0;
7426         bool ignore;
7427
7428         now = dev;
7429         iter = &dev->adj_list.upper;
7430
7431         while (1) {
7432                 if (now != dev) {
7433                         ret = fn(now, priv);
7434                         if (ret)
7435                                 return ret;
7436                 }
7437
7438                 next = NULL;
7439                 while (1) {
7440                         udev = __netdev_next_upper_dev(now, &iter, &ignore);
7441                         if (!udev)
7442                                 break;
7443                         if (ignore)
7444                                 continue;
7445
7446                         next = udev;
7447                         niter = &udev->adj_list.upper;
7448                         dev_stack[cur] = now;
7449                         iter_stack[cur++] = iter;
7450                         break;
7451                 }
7452
7453                 if (!next) {
7454                         if (!cur)
7455                                 return 0;
7456                         next = dev_stack[--cur];
7457                         niter = iter_stack[cur];
7458                 }
7459
7460                 now = next;
7461                 iter = niter;
7462         }
7463
7464         return 0;
7465 }
7466
7467 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
7468                                   int (*fn)(struct net_device *dev,
7469                                             struct netdev_nested_priv *priv),
7470                                   struct netdev_nested_priv *priv)
7471 {
7472         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7473         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7474         int ret, cur = 0;
7475
7476         now = dev;
7477         iter = &dev->adj_list.upper;
7478
7479         while (1) {
7480                 if (now != dev) {
7481                         ret = fn(now, priv);
7482                         if (ret)
7483                                 return ret;
7484                 }
7485
7486                 next = NULL;
7487                 while (1) {
7488                         udev = netdev_next_upper_dev_rcu(now, &iter);
7489                         if (!udev)
7490                                 break;
7491
7492                         next = udev;
7493                         niter = &udev->adj_list.upper;
7494                         dev_stack[cur] = now;
7495                         iter_stack[cur++] = iter;
7496                         break;
7497                 }
7498
7499                 if (!next) {
7500                         if (!cur)
7501                                 return 0;
7502                         next = dev_stack[--cur];
7503                         niter = iter_stack[cur];
7504                 }
7505
7506                 now = next;
7507                 iter = niter;
7508         }
7509
7510         return 0;
7511 }
7512 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7513
7514 static bool __netdev_has_upper_dev(struct net_device *dev,
7515                                    struct net_device *upper_dev)
7516 {
7517         struct netdev_nested_priv priv = {
7518                 .flags = 0,
7519                 .data = (void *)upper_dev,
7520         };
7521
7522         ASSERT_RTNL();
7523
7524         return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7525                                            &priv);
7526 }
7527
7528 /**
7529  * netdev_lower_get_next_private - Get the next ->private from the
7530  *                                 lower neighbour list
7531  * @dev: device
7532  * @iter: list_head ** of the current position
7533  *
7534  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7535  * list, starting from iter position. The caller must hold either hold the
7536  * RTNL lock or its own locking that guarantees that the neighbour lower
7537  * list will remain unchanged.
7538  */
7539 void *netdev_lower_get_next_private(struct net_device *dev,
7540                                     struct list_head **iter)
7541 {
7542         struct netdev_adjacent *lower;
7543
7544         lower = list_entry(*iter, struct netdev_adjacent, list);
7545
7546         if (&lower->list == &dev->adj_list.lower)
7547                 return NULL;
7548
7549         *iter = lower->list.next;
7550
7551         return lower->private;
7552 }
7553 EXPORT_SYMBOL(netdev_lower_get_next_private);
7554
7555 /**
7556  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7557  *                                     lower neighbour list, RCU
7558  *                                     variant
7559  * @dev: device
7560  * @iter: list_head ** of the current position
7561  *
7562  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7563  * list, starting from iter position. The caller must hold RCU read lock.
7564  */
7565 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7566                                         struct list_head **iter)
7567 {
7568         struct netdev_adjacent *lower;
7569
7570         WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7571
7572         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7573
7574         if (&lower->list == &dev->adj_list.lower)
7575                 return NULL;
7576
7577         *iter = &lower->list;
7578
7579         return lower->private;
7580 }
7581 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7582
7583 /**
7584  * netdev_lower_get_next - Get the next device from the lower neighbour
7585  *                         list
7586  * @dev: device
7587  * @iter: list_head ** of the current position
7588  *
7589  * Gets the next netdev_adjacent from the dev's lower neighbour
7590  * list, starting from iter position. The caller must hold RTNL lock or
7591  * its own locking that guarantees that the neighbour lower
7592  * list will remain unchanged.
7593  */
7594 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7595 {
7596         struct netdev_adjacent *lower;
7597
7598         lower = list_entry(*iter, struct netdev_adjacent, list);
7599
7600         if (&lower->list == &dev->adj_list.lower)
7601                 return NULL;
7602
7603         *iter = lower->list.next;
7604
7605         return lower->dev;
7606 }
7607 EXPORT_SYMBOL(netdev_lower_get_next);
7608
7609 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7610                                                 struct list_head **iter)
7611 {
7612         struct netdev_adjacent *lower;
7613
7614         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7615
7616         if (&lower->list == &dev->adj_list.lower)
7617                 return NULL;
7618
7619         *iter = &lower->list;
7620
7621         return lower->dev;
7622 }
7623
7624 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7625                                                   struct list_head **iter,
7626                                                   bool *ignore)
7627 {
7628         struct netdev_adjacent *lower;
7629
7630         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7631
7632         if (&lower->list == &dev->adj_list.lower)
7633                 return NULL;
7634
7635         *iter = &lower->list;
7636         *ignore = lower->ignore;
7637
7638         return lower->dev;
7639 }
7640
7641 int netdev_walk_all_lower_dev(struct net_device *dev,
7642                               int (*fn)(struct net_device *dev,
7643                                         struct netdev_nested_priv *priv),
7644                               struct netdev_nested_priv *priv)
7645 {
7646         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7647         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7648         int ret, cur = 0;
7649
7650         now = dev;
7651         iter = &dev->adj_list.lower;
7652
7653         while (1) {
7654                 if (now != dev) {
7655                         ret = fn(now, priv);
7656                         if (ret)
7657                                 return ret;
7658                 }
7659
7660                 next = NULL;
7661                 while (1) {
7662                         ldev = netdev_next_lower_dev(now, &iter);
7663                         if (!ldev)
7664                                 break;
7665
7666                         next = ldev;
7667                         niter = &ldev->adj_list.lower;
7668                         dev_stack[cur] = now;
7669                         iter_stack[cur++] = iter;
7670                         break;
7671                 }
7672
7673                 if (!next) {
7674                         if (!cur)
7675                                 return 0;
7676                         next = dev_stack[--cur];
7677                         niter = iter_stack[cur];
7678                 }
7679
7680                 now = next;
7681                 iter = niter;
7682         }
7683
7684         return 0;
7685 }
7686 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7687
7688 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7689                                        int (*fn)(struct net_device *dev,
7690                                          struct netdev_nested_priv *priv),
7691                                        struct netdev_nested_priv *priv)
7692 {
7693         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7694         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7695         int ret, cur = 0;
7696         bool ignore;
7697
7698         now = dev;
7699         iter = &dev->adj_list.lower;
7700
7701         while (1) {
7702                 if (now != dev) {
7703                         ret = fn(now, priv);
7704                         if (ret)
7705                                 return ret;
7706                 }
7707
7708                 next = NULL;
7709                 while (1) {
7710                         ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7711                         if (!ldev)
7712                                 break;
7713                         if (ignore)
7714                                 continue;
7715
7716                         next = ldev;
7717                         niter = &ldev->adj_list.lower;
7718                         dev_stack[cur] = now;
7719                         iter_stack[cur++] = iter;
7720                         break;
7721                 }
7722
7723                 if (!next) {
7724                         if (!cur)
7725                                 return 0;
7726                         next = dev_stack[--cur];
7727                         niter = iter_stack[cur];
7728                 }
7729
7730                 now = next;
7731                 iter = niter;
7732         }
7733
7734         return 0;
7735 }
7736
7737 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7738                                              struct list_head **iter)
7739 {
7740         struct netdev_adjacent *lower;
7741
7742         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7743         if (&lower->list == &dev->adj_list.lower)
7744                 return NULL;
7745
7746         *iter = &lower->list;
7747
7748         return lower->dev;
7749 }
7750 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7751
7752 static u8 __netdev_upper_depth(struct net_device *dev)
7753 {
7754         struct net_device *udev;
7755         struct list_head *iter;
7756         u8 max_depth = 0;
7757         bool ignore;
7758
7759         for (iter = &dev->adj_list.upper,
7760              udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7761              udev;
7762              udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7763                 if (ignore)
7764                         continue;
7765                 if (max_depth < udev->upper_level)
7766                         max_depth = udev->upper_level;
7767         }
7768
7769         return max_depth;
7770 }
7771
7772 static u8 __netdev_lower_depth(struct net_device *dev)
7773 {
7774         struct net_device *ldev;
7775         struct list_head *iter;
7776         u8 max_depth = 0;
7777         bool ignore;
7778
7779         for (iter = &dev->adj_list.lower,
7780              ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7781              ldev;
7782              ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7783                 if (ignore)
7784                         continue;
7785                 if (max_depth < ldev->lower_level)
7786                         max_depth = ldev->lower_level;
7787         }
7788
7789         return max_depth;
7790 }
7791
7792 static int __netdev_update_upper_level(struct net_device *dev,
7793                                        struct netdev_nested_priv *__unused)
7794 {
7795         dev->upper_level = __netdev_upper_depth(dev) + 1;
7796         return 0;
7797 }
7798
7799 static int __netdev_update_lower_level(struct net_device *dev,
7800                                        struct netdev_nested_priv *priv)
7801 {
7802         dev->lower_level = __netdev_lower_depth(dev) + 1;
7803
7804 #ifdef CONFIG_LOCKDEP
7805         if (!priv)
7806                 return 0;
7807
7808         if (priv->flags & NESTED_SYNC_IMM)
7809                 dev->nested_level = dev->lower_level - 1;
7810         if (priv->flags & NESTED_SYNC_TODO)
7811                 net_unlink_todo(dev);
7812 #endif
7813         return 0;
7814 }
7815
7816 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7817                                   int (*fn)(struct net_device *dev,
7818                                             struct netdev_nested_priv *priv),
7819                                   struct netdev_nested_priv *priv)
7820 {
7821         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7822         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7823         int ret, cur = 0;
7824
7825         now = dev;
7826         iter = &dev->adj_list.lower;
7827
7828         while (1) {
7829                 if (now != dev) {
7830                         ret = fn(now, priv);
7831                         if (ret)
7832                                 return ret;
7833                 }
7834
7835                 next = NULL;
7836                 while (1) {
7837                         ldev = netdev_next_lower_dev_rcu(now, &iter);
7838                         if (!ldev)
7839                                 break;
7840
7841                         next = ldev;
7842                         niter = &ldev->adj_list.lower;
7843                         dev_stack[cur] = now;
7844                         iter_stack[cur++] = iter;
7845                         break;
7846                 }
7847
7848                 if (!next) {
7849                         if (!cur)
7850                                 return 0;
7851                         next = dev_stack[--cur];
7852                         niter = iter_stack[cur];
7853                 }
7854
7855                 now = next;
7856                 iter = niter;
7857         }
7858
7859         return 0;
7860 }
7861 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7862
7863 /**
7864  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7865  *                                     lower neighbour list, RCU
7866  *                                     variant
7867  * @dev: device
7868  *
7869  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7870  * list. The caller must hold RCU read lock.
7871  */
7872 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7873 {
7874         struct netdev_adjacent *lower;
7875
7876         lower = list_first_or_null_rcu(&dev->adj_list.lower,
7877                         struct netdev_adjacent, list);
7878         if (lower)
7879                 return lower->private;
7880         return NULL;
7881 }
7882 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7883
7884 /**
7885  * netdev_master_upper_dev_get_rcu - Get master upper device
7886  * @dev: device
7887  *
7888  * Find a master upper device and return pointer to it or NULL in case
7889  * it's not there. The caller must hold the RCU read lock.
7890  */
7891 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7892 {
7893         struct netdev_adjacent *upper;
7894
7895         upper = list_first_or_null_rcu(&dev->adj_list.upper,
7896                                        struct netdev_adjacent, list);
7897         if (upper && likely(upper->master))
7898                 return upper->dev;
7899         return NULL;
7900 }
7901 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7902
7903 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7904                               struct net_device *adj_dev,
7905                               struct list_head *dev_list)
7906 {
7907         char linkname[IFNAMSIZ+7];
7908
7909         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7910                 "upper_%s" : "lower_%s", adj_dev->name);
7911         return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7912                                  linkname);
7913 }
7914 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7915                                char *name,
7916                                struct list_head *dev_list)
7917 {
7918         char linkname[IFNAMSIZ+7];
7919
7920         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7921                 "upper_%s" : "lower_%s", name);
7922         sysfs_remove_link(&(dev->dev.kobj), linkname);
7923 }
7924
7925 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7926                                                  struct net_device *adj_dev,
7927                                                  struct list_head *dev_list)
7928 {
7929         return (dev_list == &dev->adj_list.upper ||
7930                 dev_list == &dev->adj_list.lower) &&
7931                 net_eq(dev_net(dev), dev_net(adj_dev));
7932 }
7933
7934 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7935                                         struct net_device *adj_dev,
7936                                         struct list_head *dev_list,
7937                                         void *private, bool master)
7938 {
7939         struct netdev_adjacent *adj;
7940         int ret;
7941
7942         adj = __netdev_find_adj(adj_dev, dev_list);
7943
7944         if (adj) {
7945                 adj->ref_nr += 1;
7946                 pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7947                          dev->name, adj_dev->name, adj->ref_nr);
7948
7949                 return 0;
7950         }
7951
7952         adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7953         if (!adj)
7954                 return -ENOMEM;
7955
7956         adj->dev = adj_dev;
7957         adj->master = master;
7958         adj->ref_nr = 1;
7959         adj->private = private;
7960         adj->ignore = false;
7961         dev_hold(adj_dev);
7962
7963         pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7964                  dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7965
7966         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7967                 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7968                 if (ret)
7969                         goto free_adj;
7970         }
7971
7972         /* Ensure that master link is always the first item in list. */
7973         if (master) {
7974                 ret = sysfs_create_link(&(dev->dev.kobj),
7975                                         &(adj_dev->dev.kobj), "master");
7976                 if (ret)
7977                         goto remove_symlinks;
7978
7979                 list_add_rcu(&adj->list, dev_list);
7980         } else {
7981                 list_add_tail_rcu(&adj->list, dev_list);
7982         }
7983
7984         return 0;
7985
7986 remove_symlinks:
7987         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7988                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7989 free_adj:
7990         kfree(adj);
7991         dev_put(adj_dev);
7992
7993         return ret;
7994 }
7995
7996 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7997                                          struct net_device *adj_dev,
7998                                          u16 ref_nr,
7999                                          struct list_head *dev_list)
8000 {
8001         struct netdev_adjacent *adj;
8002
8003         pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
8004                  dev->name, adj_dev->name, ref_nr);
8005
8006         adj = __netdev_find_adj(adj_dev, dev_list);
8007
8008         if (!adj) {
8009                 pr_err("Adjacency does not exist for device %s from %s\n",
8010                        dev->name, adj_dev->name);
8011                 WARN_ON(1);
8012                 return;
8013         }
8014
8015         if (adj->ref_nr > ref_nr) {
8016                 pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
8017                          dev->name, adj_dev->name, ref_nr,
8018                          adj->ref_nr - ref_nr);
8019                 adj->ref_nr -= ref_nr;
8020                 return;
8021         }
8022
8023         if (adj->master)
8024                 sysfs_remove_link(&(dev->dev.kobj), "master");
8025
8026         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
8027                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
8028
8029         list_del_rcu(&adj->list);
8030         pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
8031                  adj_dev->name, dev->name, adj_dev->name);
8032         dev_put(adj_dev);
8033         kfree_rcu(adj, rcu);
8034 }
8035
8036 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
8037                                             struct net_device *upper_dev,
8038                                             struct list_head *up_list,
8039                                             struct list_head *down_list,
8040                                             void *private, bool master)
8041 {
8042         int ret;
8043
8044         ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
8045                                            private, master);
8046         if (ret)
8047                 return ret;
8048
8049         ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
8050                                            private, false);
8051         if (ret) {
8052                 __netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
8053                 return ret;
8054         }
8055
8056         return 0;
8057 }
8058
8059 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
8060                                                struct net_device *upper_dev,
8061                                                u16 ref_nr,
8062                                                struct list_head *up_list,
8063                                                struct list_head *down_list)
8064 {
8065         __netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
8066         __netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
8067 }
8068
8069 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
8070                                                 struct net_device *upper_dev,
8071                                                 void *private, bool master)
8072 {
8073         return __netdev_adjacent_dev_link_lists(dev, upper_dev,
8074                                                 &dev->adj_list.upper,
8075                                                 &upper_dev->adj_list.lower,
8076                                                 private, master);
8077 }
8078
8079 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
8080                                                    struct net_device *upper_dev)
8081 {
8082         __netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
8083                                            &dev->adj_list.upper,
8084                                            &upper_dev->adj_list.lower);
8085 }
8086
8087 static int __netdev_upper_dev_link(struct net_device *dev,
8088                                    struct net_device *upper_dev, bool master,
8089                                    void *upper_priv, void *upper_info,
8090                                    struct netdev_nested_priv *priv,
8091                                    struct netlink_ext_ack *extack)
8092 {
8093         struct netdev_notifier_changeupper_info changeupper_info = {
8094                 .info = {
8095                         .dev = dev,
8096                         .extack = extack,
8097                 },
8098                 .upper_dev = upper_dev,
8099                 .master = master,
8100                 .linking = true,
8101                 .upper_info = upper_info,
8102         };
8103         struct net_device *master_dev;
8104         int ret = 0;
8105
8106         ASSERT_RTNL();
8107
8108         if (dev == upper_dev)
8109                 return -EBUSY;
8110
8111         /* To prevent loops, check if dev is not upper device to upper_dev. */
8112         if (__netdev_has_upper_dev(upper_dev, dev))
8113                 return -EBUSY;
8114
8115         if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
8116                 return -EMLINK;
8117
8118         if (!master) {
8119                 if (__netdev_has_upper_dev(dev, upper_dev))
8120                         return -EEXIST;
8121         } else {
8122                 master_dev = __netdev_master_upper_dev_get(dev);
8123                 if (master_dev)
8124                         return master_dev == upper_dev ? -EEXIST : -EBUSY;
8125         }
8126
8127         ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
8128                                             &changeupper_info.info);
8129         ret = notifier_to_errno(ret);
8130         if (ret)
8131                 return ret;
8132
8133         ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
8134                                                    master);
8135         if (ret)
8136                 return ret;
8137
8138         ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
8139                                             &changeupper_info.info);
8140         ret = notifier_to_errno(ret);
8141         if (ret)
8142                 goto rollback;
8143
8144         __netdev_update_upper_level(dev, NULL);
8145         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
8146
8147         __netdev_update_lower_level(upper_dev, priv);
8148         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
8149                                     priv);
8150
8151         return 0;
8152
8153 rollback:
8154         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
8155
8156         return ret;
8157 }
8158
8159 /**
8160  * netdev_upper_dev_link - Add a link to the upper device
8161  * @dev: device
8162  * @upper_dev: new upper device
8163  * @extack: netlink extended ack
8164  *
8165  * Adds a link to device which is upper to this one. The caller must hold
8166  * the RTNL lock. On a failure a negative errno code is returned.
8167  * On success the reference counts are adjusted and the function
8168  * returns zero.
8169  */
8170 int netdev_upper_dev_link(struct net_device *dev,
8171                           struct net_device *upper_dev,
8172                           struct netlink_ext_ack *extack)
8173 {
8174         struct netdev_nested_priv priv = {
8175                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
8176                 .data = NULL,
8177         };
8178
8179         return __netdev_upper_dev_link(dev, upper_dev, false,
8180                                        NULL, NULL, &priv, extack);
8181 }
8182 EXPORT_SYMBOL(netdev_upper_dev_link);
8183
8184 /**
8185  * netdev_master_upper_dev_link - Add a master link to the upper device
8186  * @dev: device
8187  * @upper_dev: new upper device
8188  * @upper_priv: upper device private
8189  * @upper_info: upper info to be passed down via notifier
8190  * @extack: netlink extended ack
8191  *
8192  * Adds a link to device which is upper to this one. In this case, only
8193  * one master upper device can be linked, although other non-master devices
8194  * might be linked as well. The caller must hold the RTNL lock.
8195  * On a failure a negative errno code is returned. On success the reference
8196  * counts are adjusted and the function returns zero.
8197  */
8198 int netdev_master_upper_dev_link(struct net_device *dev,
8199                                  struct net_device *upper_dev,
8200                                  void *upper_priv, void *upper_info,
8201                                  struct netlink_ext_ack *extack)
8202 {
8203         struct netdev_nested_priv priv = {
8204                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
8205                 .data = NULL,
8206         };
8207
8208         return __netdev_upper_dev_link(dev, upper_dev, true,
8209                                        upper_priv, upper_info, &priv, extack);
8210 }
8211 EXPORT_SYMBOL(netdev_master_upper_dev_link);
8212
8213 static void __netdev_upper_dev_unlink(struct net_device *dev,
8214                                       struct net_device *upper_dev,
8215                                       struct netdev_nested_priv *priv)
8216 {
8217         struct netdev_notifier_changeupper_info changeupper_info = {
8218                 .info = {
8219                         .dev = dev,
8220                 },
8221                 .upper_dev = upper_dev,
8222                 .linking = false,
8223         };
8224
8225         ASSERT_RTNL();
8226
8227         changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
8228
8229         call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
8230                                       &changeupper_info.info);
8231
8232         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
8233
8234         call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
8235                                       &changeupper_info.info);
8236
8237         __netdev_update_upper_level(dev, NULL);
8238         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
8239
8240         __netdev_update_lower_level(upper_dev, priv);
8241         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
8242                                     priv);
8243 }
8244
8245 /**
8246  * netdev_upper_dev_unlink - Removes a link to upper device
8247  * @dev: device
8248  * @upper_dev: new upper device
8249  *
8250  * Removes a link to device which is upper to this one. The caller must hold
8251  * the RTNL lock.
8252  */
8253 void netdev_upper_dev_unlink(struct net_device *dev,
8254                              struct net_device *upper_dev)
8255 {
8256         struct netdev_nested_priv priv = {
8257                 .flags = NESTED_SYNC_TODO,
8258                 .data = NULL,
8259         };
8260
8261         __netdev_upper_dev_unlink(dev, upper_dev, &priv);
8262 }
8263 EXPORT_SYMBOL(netdev_upper_dev_unlink);
8264
8265 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
8266                                       struct net_device *lower_dev,
8267                                       bool val)
8268 {
8269         struct netdev_adjacent *adj;
8270
8271         adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
8272         if (adj)
8273                 adj->ignore = val;
8274
8275         adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
8276         if (adj)
8277                 adj->ignore = val;
8278 }
8279
8280 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
8281                                         struct net_device *lower_dev)
8282 {
8283         __netdev_adjacent_dev_set(upper_dev, lower_dev, true);
8284 }
8285
8286 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
8287                                        struct net_device *lower_dev)
8288 {
8289         __netdev_adjacent_dev_set(upper_dev, lower_dev, false);
8290 }
8291
8292 int netdev_adjacent_change_prepare(struct net_device *old_dev,
8293                                    struct net_device *new_dev,
8294                                    struct net_device *dev,
8295                                    struct netlink_ext_ack *extack)
8296 {
8297         struct netdev_nested_priv priv = {
8298                 .flags = 0,
8299                 .data = NULL,
8300         };
8301         int err;
8302
8303         if (!new_dev)
8304                 return 0;
8305
8306         if (old_dev && new_dev != old_dev)
8307                 netdev_adjacent_dev_disable(dev, old_dev);
8308         err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
8309                                       extack);
8310         if (err) {
8311                 if (old_dev && new_dev != old_dev)
8312                         netdev_adjacent_dev_enable(dev, old_dev);
8313                 return err;
8314         }
8315
8316         return 0;
8317 }
8318 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
8319
8320 void netdev_adjacent_change_commit(struct net_device *old_dev,
8321                                    struct net_device *new_dev,
8322                                    struct net_device *dev)
8323 {
8324         struct netdev_nested_priv priv = {
8325                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
8326                 .data = NULL,
8327         };
8328
8329         if (!new_dev || !old_dev)
8330                 return;
8331
8332         if (new_dev == old_dev)
8333                 return;
8334
8335         netdev_adjacent_dev_enable(dev, old_dev);
8336         __netdev_upper_dev_unlink(old_dev, dev, &priv);
8337 }
8338 EXPORT_SYMBOL(netdev_adjacent_change_commit);
8339
8340 void netdev_adjacent_change_abort(struct net_device *old_dev,
8341                                   struct net_device *new_dev,
8342                                   struct net_device *dev)
8343 {
8344         struct netdev_nested_priv priv = {
8345                 .flags = 0,
8346                 .data = NULL,
8347         };
8348
8349         if (!new_dev)
8350                 return;
8351
8352         if (old_dev && new_dev != old_dev)
8353                 netdev_adjacent_dev_enable(dev, old_dev);
8354
8355         __netdev_upper_dev_unlink(new_dev, dev, &priv);
8356 }
8357 EXPORT_SYMBOL(netdev_adjacent_change_abort);
8358
8359 /**
8360  * netdev_bonding_info_change - Dispatch event about slave change
8361  * @dev: device
8362  * @bonding_info: info to dispatch
8363  *
8364  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
8365  * The caller must hold the RTNL lock.
8366  */
8367 void netdev_bonding_info_change(struct net_device *dev,
8368                                 struct netdev_bonding_info *bonding_info)
8369 {
8370         struct netdev_notifier_bonding_info info = {
8371                 .info.dev = dev,
8372         };
8373
8374         memcpy(&info.bonding_info, bonding_info,
8375                sizeof(struct netdev_bonding_info));
8376         call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
8377                                       &info.info);
8378 }
8379 EXPORT_SYMBOL(netdev_bonding_info_change);
8380
8381 /**
8382  * netdev_get_xmit_slave - Get the xmit slave of master device
8383  * @dev: device
8384  * @skb: The packet
8385  * @all_slaves: assume all the slaves are active
8386  *
8387  * The reference counters are not incremented so the caller must be
8388  * careful with locks. The caller must hold RCU lock.
8389  * %NULL is returned if no slave is found.
8390  */
8391
8392 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8393                                          struct sk_buff *skb,
8394                                          bool all_slaves)
8395 {
8396         const struct net_device_ops *ops = dev->netdev_ops;
8397
8398         if (!ops->ndo_get_xmit_slave)
8399                 return NULL;
8400         return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8401 }
8402 EXPORT_SYMBOL(netdev_get_xmit_slave);
8403
8404 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8405                                                   struct sock *sk)
8406 {
8407         const struct net_device_ops *ops = dev->netdev_ops;
8408
8409         if (!ops->ndo_sk_get_lower_dev)
8410                 return NULL;
8411         return ops->ndo_sk_get_lower_dev(dev, sk);
8412 }
8413
8414 /**
8415  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8416  * @dev: device
8417  * @sk: the socket
8418  *
8419  * %NULL is returned if no lower device is found.
8420  */
8421
8422 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8423                                             struct sock *sk)
8424 {
8425         struct net_device *lower;
8426
8427         lower = netdev_sk_get_lower_dev(dev, sk);
8428         while (lower) {
8429                 dev = lower;
8430                 lower = netdev_sk_get_lower_dev(dev, sk);
8431         }
8432
8433         return dev;
8434 }
8435 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8436
8437 static void netdev_adjacent_add_links(struct net_device *dev)
8438 {
8439         struct netdev_adjacent *iter;
8440
8441         struct net *net = dev_net(dev);
8442
8443         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8444                 if (!net_eq(net, dev_net(iter->dev)))
8445                         continue;
8446                 netdev_adjacent_sysfs_add(iter->dev, dev,
8447                                           &iter->dev->adj_list.lower);
8448                 netdev_adjacent_sysfs_add(dev, iter->dev,
8449                                           &dev->adj_list.upper);
8450         }
8451
8452         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8453                 if (!net_eq(net, dev_net(iter->dev)))
8454                         continue;
8455                 netdev_adjacent_sysfs_add(iter->dev, dev,
8456                                           &iter->dev->adj_list.upper);
8457                 netdev_adjacent_sysfs_add(dev, iter->dev,
8458                                           &dev->adj_list.lower);
8459         }
8460 }
8461
8462 static void netdev_adjacent_del_links(struct net_device *dev)
8463 {
8464         struct netdev_adjacent *iter;
8465
8466         struct net *net = dev_net(dev);
8467
8468         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8469                 if (!net_eq(net, dev_net(iter->dev)))
8470                         continue;
8471                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8472                                           &iter->dev->adj_list.lower);
8473                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8474                                           &dev->adj_list.upper);
8475         }
8476
8477         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8478                 if (!net_eq(net, dev_net(iter->dev)))
8479                         continue;
8480                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8481                                           &iter->dev->adj_list.upper);
8482                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8483                                           &dev->adj_list.lower);
8484         }
8485 }
8486
8487 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8488 {
8489         struct netdev_adjacent *iter;
8490
8491         struct net *net = dev_net(dev);
8492
8493         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8494                 if (!net_eq(net, dev_net(iter->dev)))
8495                         continue;
8496                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8497                                           &iter->dev->adj_list.lower);
8498                 netdev_adjacent_sysfs_add(iter->dev, dev,
8499                                           &iter->dev->adj_list.lower);
8500         }
8501
8502         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8503                 if (!net_eq(net, dev_net(iter->dev)))
8504                         continue;
8505                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8506                                           &iter->dev->adj_list.upper);
8507                 netdev_adjacent_sysfs_add(iter->dev, dev,
8508                                           &iter->dev->adj_list.upper);
8509         }
8510 }
8511
8512 void *netdev_lower_dev_get_private(struct net_device *dev,
8513                                    struct net_device *lower_dev)
8514 {
8515         struct netdev_adjacent *lower;
8516
8517         if (!lower_dev)
8518                 return NULL;
8519         lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8520         if (!lower)
8521                 return NULL;
8522
8523         return lower->private;
8524 }
8525 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8526
8527
8528 /**
8529  * netdev_lower_state_changed - Dispatch event about lower device state change
8530  * @lower_dev: device
8531  * @lower_state_info: state to dispatch
8532  *
8533  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8534  * The caller must hold the RTNL lock.
8535  */
8536 void netdev_lower_state_changed(struct net_device *lower_dev,
8537                                 void *lower_state_info)
8538 {
8539         struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8540                 .info.dev = lower_dev,
8541         };
8542
8543         ASSERT_RTNL();
8544         changelowerstate_info.lower_state_info = lower_state_info;
8545         call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8546                                       &changelowerstate_info.info);
8547 }
8548 EXPORT_SYMBOL(netdev_lower_state_changed);
8549
8550 static void dev_change_rx_flags(struct net_device *dev, int flags)
8551 {
8552         const struct net_device_ops *ops = dev->netdev_ops;
8553
8554         if (ops->ndo_change_rx_flags)
8555                 ops->ndo_change_rx_flags(dev, flags);
8556 }
8557
8558 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8559 {
8560         unsigned int old_flags = dev->flags;
8561         kuid_t uid;
8562         kgid_t gid;
8563
8564         ASSERT_RTNL();
8565
8566         dev->flags |= IFF_PROMISC;
8567         dev->promiscuity += inc;
8568         if (dev->promiscuity == 0) {
8569                 /*
8570                  * Avoid overflow.
8571                  * If inc causes overflow, untouch promisc and return error.
8572                  */
8573                 if (inc < 0)
8574                         dev->flags &= ~IFF_PROMISC;
8575                 else {
8576                         dev->promiscuity -= inc;
8577                         netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8578                         return -EOVERFLOW;
8579                 }
8580         }
8581         if (dev->flags != old_flags) {
8582                 pr_info("device %s %s promiscuous mode\n",
8583                         dev->name,
8584                         dev->flags & IFF_PROMISC ? "entered" : "left");
8585                 if (audit_enabled) {
8586                         current_uid_gid(&uid, &gid);
8587                         audit_log(audit_context(), GFP_ATOMIC,
8588                                   AUDIT_ANOM_PROMISCUOUS,
8589                                   "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8590                                   dev->name, (dev->flags & IFF_PROMISC),
8591                                   (old_flags & IFF_PROMISC),
8592                                   from_kuid(&init_user_ns, audit_get_loginuid(current)),
8593                                   from_kuid(&init_user_ns, uid),
8594                                   from_kgid(&init_user_ns, gid),
8595                                   audit_get_sessionid(current));
8596                 }
8597
8598                 dev_change_rx_flags(dev, IFF_PROMISC);
8599         }
8600         if (notify)
8601                 __dev_notify_flags(dev, old_flags, IFF_PROMISC);
8602         return 0;
8603 }
8604
8605 /**
8606  *      dev_set_promiscuity     - update promiscuity count on a device
8607  *      @dev: device
8608  *      @inc: modifier
8609  *
8610  *      Add or remove promiscuity from a device. While the count in the device
8611  *      remains above zero the interface remains promiscuous. Once it hits zero
8612  *      the device reverts back to normal filtering operation. A negative inc
8613  *      value is used to drop promiscuity on the device.
8614  *      Return 0 if successful or a negative errno code on error.
8615  */
8616 int dev_set_promiscuity(struct net_device *dev, int inc)
8617 {
8618         unsigned int old_flags = dev->flags;
8619         int err;
8620
8621         err = __dev_set_promiscuity(dev, inc, true);
8622         if (err < 0)
8623                 return err;
8624         if (dev->flags != old_flags)
8625                 dev_set_rx_mode(dev);
8626         return err;
8627 }
8628 EXPORT_SYMBOL(dev_set_promiscuity);
8629
8630 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8631 {
8632         unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8633
8634         ASSERT_RTNL();
8635
8636         dev->flags |= IFF_ALLMULTI;
8637         dev->allmulti += inc;
8638         if (dev->allmulti == 0) {
8639                 /*
8640                  * Avoid overflow.
8641                  * If inc causes overflow, untouch allmulti and return error.
8642                  */
8643                 if (inc < 0)
8644                         dev->flags &= ~IFF_ALLMULTI;
8645                 else {
8646                         dev->allmulti -= inc;
8647                         netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8648                         return -EOVERFLOW;
8649                 }
8650         }
8651         if (dev->flags ^ old_flags) {
8652                 dev_change_rx_flags(dev, IFF_ALLMULTI);
8653                 dev_set_rx_mode(dev);
8654                 if (notify)
8655                         __dev_notify_flags(dev, old_flags,
8656                                            dev->gflags ^ old_gflags);
8657         }
8658         return 0;
8659 }
8660
8661 /**
8662  *      dev_set_allmulti        - update allmulti count on a device
8663  *      @dev: device
8664  *      @inc: modifier
8665  *
8666  *      Add or remove reception of all multicast frames to a device. While the
8667  *      count in the device remains above zero the interface remains listening
8668  *      to all interfaces. Once it hits zero the device reverts back to normal
8669  *      filtering operation. A negative @inc value is used to drop the counter
8670  *      when releasing a resource needing all multicasts.
8671  *      Return 0 if successful or a negative errno code on error.
8672  */
8673
8674 int dev_set_allmulti(struct net_device *dev, int inc)
8675 {
8676         return __dev_set_allmulti(dev, inc, true);
8677 }
8678 EXPORT_SYMBOL(dev_set_allmulti);
8679
8680 /*
8681  *      Upload unicast and multicast address lists to device and
8682  *      configure RX filtering. When the device doesn't support unicast
8683  *      filtering it is put in promiscuous mode while unicast addresses
8684  *      are present.
8685  */
8686 void __dev_set_rx_mode(struct net_device *dev)
8687 {
8688         const struct net_device_ops *ops = dev->netdev_ops;
8689
8690         /* dev_open will call this function so the list will stay sane. */
8691         if (!(dev->flags&IFF_UP))
8692                 return;
8693
8694         if (!netif_device_present(dev))
8695                 return;
8696
8697         if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8698                 /* Unicast addresses changes may only happen under the rtnl,
8699                  * therefore calling __dev_set_promiscuity here is safe.
8700                  */
8701                 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8702                         __dev_set_promiscuity(dev, 1, false);
8703                         dev->uc_promisc = true;
8704                 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8705                         __dev_set_promiscuity(dev, -1, false);
8706                         dev->uc_promisc = false;
8707                 }
8708         }
8709
8710         if (ops->ndo_set_rx_mode)
8711                 ops->ndo_set_rx_mode(dev);
8712 }
8713
8714 void dev_set_rx_mode(struct net_device *dev)
8715 {
8716         netif_addr_lock_bh(dev);
8717         __dev_set_rx_mode(dev);
8718         netif_addr_unlock_bh(dev);
8719 }
8720
8721 /**
8722  *      dev_get_flags - get flags reported to userspace
8723  *      @dev: device
8724  *
8725  *      Get the combination of flag bits exported through APIs to userspace.
8726  */
8727 unsigned int dev_get_flags(const struct net_device *dev)
8728 {
8729         unsigned int flags;
8730
8731         flags = (dev->flags & ~(IFF_PROMISC |
8732                                 IFF_ALLMULTI |
8733                                 IFF_RUNNING |
8734                                 IFF_LOWER_UP |
8735                                 IFF_DORMANT)) |
8736                 (dev->gflags & (IFF_PROMISC |
8737                                 IFF_ALLMULTI));
8738
8739         if (netif_running(dev)) {
8740                 if (netif_oper_up(dev))
8741                         flags |= IFF_RUNNING;
8742                 if (netif_carrier_ok(dev))
8743                         flags |= IFF_LOWER_UP;
8744                 if (netif_dormant(dev))
8745                         flags |= IFF_DORMANT;
8746         }
8747
8748         return flags;
8749 }
8750 EXPORT_SYMBOL(dev_get_flags);
8751
8752 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8753                        struct netlink_ext_ack *extack)
8754 {
8755         unsigned int old_flags = dev->flags;
8756         int ret;
8757
8758         ASSERT_RTNL();
8759
8760         /*
8761          *      Set the flags on our device.
8762          */
8763
8764         dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8765                                IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8766                                IFF_AUTOMEDIA)) |
8767                      (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8768                                     IFF_ALLMULTI));
8769
8770         /*
8771          *      Load in the correct multicast list now the flags have changed.
8772          */
8773
8774         if ((old_flags ^ flags) & IFF_MULTICAST)
8775                 dev_change_rx_flags(dev, IFF_MULTICAST);
8776
8777         dev_set_rx_mode(dev);
8778
8779         /*
8780          *      Have we downed the interface. We handle IFF_UP ourselves
8781          *      according to user attempts to set it, rather than blindly
8782          *      setting it.
8783          */
8784
8785         ret = 0;
8786         if ((old_flags ^ flags) & IFF_UP) {
8787                 if (old_flags & IFF_UP)
8788                         __dev_close(dev);
8789                 else
8790                         ret = __dev_open(dev, extack);
8791         }
8792
8793         if ((flags ^ dev->gflags) & IFF_PROMISC) {
8794                 int inc = (flags & IFF_PROMISC) ? 1 : -1;
8795                 unsigned int old_flags = dev->flags;
8796
8797                 dev->gflags ^= IFF_PROMISC;
8798
8799                 if (__dev_set_promiscuity(dev, inc, false) >= 0)
8800                         if (dev->flags != old_flags)
8801                                 dev_set_rx_mode(dev);
8802         }
8803
8804         /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8805          * is important. Some (broken) drivers set IFF_PROMISC, when
8806          * IFF_ALLMULTI is requested not asking us and not reporting.
8807          */
8808         if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8809                 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8810
8811                 dev->gflags ^= IFF_ALLMULTI;
8812                 __dev_set_allmulti(dev, inc, false);
8813         }
8814
8815         return ret;
8816 }
8817
8818 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8819                         unsigned int gchanges)
8820 {
8821         unsigned int changes = dev->flags ^ old_flags;
8822
8823         if (gchanges)
8824                 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
8825
8826         if (changes & IFF_UP) {
8827                 if (dev->flags & IFF_UP)
8828                         call_netdevice_notifiers(NETDEV_UP, dev);
8829                 else
8830                         call_netdevice_notifiers(NETDEV_DOWN, dev);
8831         }
8832
8833         if (dev->flags & IFF_UP &&
8834             (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8835                 struct netdev_notifier_change_info change_info = {
8836                         .info = {
8837                                 .dev = dev,
8838                         },
8839                         .flags_changed = changes,
8840                 };
8841
8842                 call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8843         }
8844 }
8845
8846 /**
8847  *      dev_change_flags - change device settings
8848  *      @dev: device
8849  *      @flags: device state flags
8850  *      @extack: netlink extended ack
8851  *
8852  *      Change settings on device based state flags. The flags are
8853  *      in the userspace exported format.
8854  */
8855 int dev_change_flags(struct net_device *dev, unsigned int flags,
8856                      struct netlink_ext_ack *extack)
8857 {
8858         int ret;
8859         unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8860
8861         ret = __dev_change_flags(dev, flags, extack);
8862         if (ret < 0)
8863                 return ret;
8864
8865         changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8866         __dev_notify_flags(dev, old_flags, changes);
8867         return ret;
8868 }
8869 EXPORT_SYMBOL(dev_change_flags);
8870
8871 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8872 {
8873         const struct net_device_ops *ops = dev->netdev_ops;
8874
8875         if (ops->ndo_change_mtu)
8876                 return ops->ndo_change_mtu(dev, new_mtu);
8877
8878         /* Pairs with all the lockless reads of dev->mtu in the stack */
8879         WRITE_ONCE(dev->mtu, new_mtu);
8880         return 0;
8881 }
8882 EXPORT_SYMBOL(__dev_set_mtu);
8883
8884 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8885                      struct netlink_ext_ack *extack)
8886 {
8887         /* MTU must be positive, and in range */
8888         if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8889                 NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8890                 return -EINVAL;
8891         }
8892
8893         if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8894                 NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8895                 return -EINVAL;
8896         }
8897         return 0;
8898 }
8899
8900 /**
8901  *      dev_set_mtu_ext - Change maximum transfer unit
8902  *      @dev: device
8903  *      @new_mtu: new transfer unit
8904  *      @extack: netlink extended ack
8905  *
8906  *      Change the maximum transfer size of the network device.
8907  */
8908 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8909                     struct netlink_ext_ack *extack)
8910 {
8911         int err, orig_mtu;
8912
8913         if (new_mtu == dev->mtu)
8914                 return 0;
8915
8916         err = dev_validate_mtu(dev, new_mtu, extack);
8917         if (err)
8918                 return err;
8919
8920         if (!netif_device_present(dev))
8921                 return -ENODEV;
8922
8923         err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8924         err = notifier_to_errno(err);
8925         if (err)
8926                 return err;
8927
8928         orig_mtu = dev->mtu;
8929         err = __dev_set_mtu(dev, new_mtu);
8930
8931         if (!err) {
8932                 err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8933                                                    orig_mtu);
8934                 err = notifier_to_errno(err);
8935                 if (err) {
8936                         /* setting mtu back and notifying everyone again,
8937                          * so that they have a chance to revert changes.
8938                          */
8939                         __dev_set_mtu(dev, orig_mtu);
8940                         call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8941                                                      new_mtu);
8942                 }
8943         }
8944         return err;
8945 }
8946
8947 int dev_set_mtu(struct net_device *dev, int new_mtu)
8948 {
8949         struct netlink_ext_ack extack;
8950         int err;
8951
8952         memset(&extack, 0, sizeof(extack));
8953         err = dev_set_mtu_ext(dev, new_mtu, &extack);
8954         if (err && extack._msg)
8955                 net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8956         return err;
8957 }
8958 EXPORT_SYMBOL(dev_set_mtu);
8959
8960 /**
8961  *      dev_change_tx_queue_len - Change TX queue length of a netdevice
8962  *      @dev: device
8963  *      @new_len: new tx queue length
8964  */
8965 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8966 {
8967         unsigned int orig_len = dev->tx_queue_len;
8968         int res;
8969
8970         if (new_len != (unsigned int)new_len)
8971                 return -ERANGE;
8972
8973         if (new_len != orig_len) {
8974                 dev->tx_queue_len = new_len;
8975                 res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8976                 res = notifier_to_errno(res);
8977                 if (res)
8978                         goto err_rollback;
8979                 res = dev_qdisc_change_tx_queue_len(dev);
8980                 if (res)
8981                         goto err_rollback;
8982         }
8983
8984         return 0;
8985
8986 err_rollback:
8987         netdev_err(dev, "refused to change device tx_queue_len\n");
8988         dev->tx_queue_len = orig_len;
8989         return res;
8990 }
8991
8992 /**
8993  *      dev_set_group - Change group this device belongs to
8994  *      @dev: device
8995  *      @new_group: group this device should belong to
8996  */
8997 void dev_set_group(struct net_device *dev, int new_group)
8998 {
8999         dev->group = new_group;
9000 }
9001 EXPORT_SYMBOL(dev_set_group);
9002
9003 /**
9004  *      dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
9005  *      @dev: device
9006  *      @addr: new address
9007  *      @extack: netlink extended ack
9008  */
9009 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
9010                               struct netlink_ext_ack *extack)
9011 {
9012         struct netdev_notifier_pre_changeaddr_info info = {
9013                 .info.dev = dev,
9014                 .info.extack = extack,
9015                 .dev_addr = addr,
9016         };
9017         int rc;
9018
9019         rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
9020         return notifier_to_errno(rc);
9021 }
9022 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
9023
9024 /**
9025  *      dev_set_mac_address - Change Media Access Control Address
9026  *      @dev: device
9027  *      @sa: new address
9028  *      @extack: netlink extended ack
9029  *
9030  *      Change the hardware (MAC) address of the device
9031  */
9032 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
9033                         struct netlink_ext_ack *extack)
9034 {
9035         const struct net_device_ops *ops = dev->netdev_ops;
9036         int err;
9037
9038         if (!ops->ndo_set_mac_address)
9039                 return -EOPNOTSUPP;
9040         if (sa->sa_family != dev->type)
9041                 return -EINVAL;
9042         if (!netif_device_present(dev))
9043                 return -ENODEV;
9044         err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
9045         if (err)
9046                 return err;
9047         err = ops->ndo_set_mac_address(dev, sa);
9048         if (err)
9049                 return err;
9050         dev->addr_assign_type = NET_ADDR_SET;
9051         call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
9052         add_device_randomness(dev->dev_addr, dev->addr_len);
9053         return 0;
9054 }
9055 EXPORT_SYMBOL(dev_set_mac_address);
9056
9057 static DECLARE_RWSEM(dev_addr_sem);
9058
9059 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
9060                              struct netlink_ext_ack *extack)
9061 {
9062         int ret;
9063
9064         down_write(&dev_addr_sem);
9065         ret = dev_set_mac_address(dev, sa, extack);
9066         up_write(&dev_addr_sem);
9067         return ret;
9068 }
9069 EXPORT_SYMBOL(dev_set_mac_address_user);
9070
9071 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
9072 {
9073         size_t size = sizeof(sa->sa_data);
9074         struct net_device *dev;
9075         int ret = 0;
9076
9077         down_read(&dev_addr_sem);
9078         rcu_read_lock();
9079
9080         dev = dev_get_by_name_rcu(net, dev_name);
9081         if (!dev) {
9082                 ret = -ENODEV;
9083                 goto unlock;
9084         }
9085         if (!dev->addr_len)
9086                 memset(sa->sa_data, 0, size);
9087         else
9088                 memcpy(sa->sa_data, dev->dev_addr,
9089                        min_t(size_t, size, dev->addr_len));
9090         sa->sa_family = dev->type;
9091
9092 unlock:
9093         rcu_read_unlock();
9094         up_read(&dev_addr_sem);
9095         return ret;
9096 }
9097 EXPORT_SYMBOL(dev_get_mac_address);
9098
9099 /**
9100  *      dev_change_carrier - Change device carrier
9101  *      @dev: device
9102  *      @new_carrier: new value
9103  *
9104  *      Change device carrier
9105  */
9106 int dev_change_carrier(struct net_device *dev, bool new_carrier)
9107 {
9108         const struct net_device_ops *ops = dev->netdev_ops;
9109
9110         if (!ops->ndo_change_carrier)
9111                 return -EOPNOTSUPP;
9112         if (!netif_device_present(dev))
9113                 return -ENODEV;
9114         return ops->ndo_change_carrier(dev, new_carrier);
9115 }
9116 EXPORT_SYMBOL(dev_change_carrier);
9117
9118 /**
9119  *      dev_get_phys_port_id - Get device physical port ID
9120  *      @dev: device
9121  *      @ppid: port ID
9122  *
9123  *      Get device physical port ID
9124  */
9125 int dev_get_phys_port_id(struct net_device *dev,
9126                          struct netdev_phys_item_id *ppid)
9127 {
9128         const struct net_device_ops *ops = dev->netdev_ops;
9129
9130         if (!ops->ndo_get_phys_port_id)
9131                 return -EOPNOTSUPP;
9132         return ops->ndo_get_phys_port_id(dev, ppid);
9133 }
9134 EXPORT_SYMBOL(dev_get_phys_port_id);
9135
9136 /**
9137  *      dev_get_phys_port_name - Get device physical port name
9138  *      @dev: device
9139  *      @name: port name
9140  *      @len: limit of bytes to copy to name
9141  *
9142  *      Get device physical port name
9143  */
9144 int dev_get_phys_port_name(struct net_device *dev,
9145                            char *name, size_t len)
9146 {
9147         const struct net_device_ops *ops = dev->netdev_ops;
9148         int err;
9149
9150         if (ops->ndo_get_phys_port_name) {
9151                 err = ops->ndo_get_phys_port_name(dev, name, len);
9152                 if (err != -EOPNOTSUPP)
9153                         return err;
9154         }
9155         return devlink_compat_phys_port_name_get(dev, name, len);
9156 }
9157 EXPORT_SYMBOL(dev_get_phys_port_name);
9158
9159 /**
9160  *      dev_get_port_parent_id - Get the device's port parent identifier
9161  *      @dev: network device
9162  *      @ppid: pointer to a storage for the port's parent identifier
9163  *      @recurse: allow/disallow recursion to lower devices
9164  *
9165  *      Get the devices's port parent identifier
9166  */
9167 int dev_get_port_parent_id(struct net_device *dev,
9168                            struct netdev_phys_item_id *ppid,
9169                            bool recurse)
9170 {
9171         const struct net_device_ops *ops = dev->netdev_ops;
9172         struct netdev_phys_item_id first = { };
9173         struct net_device *lower_dev;
9174         struct list_head *iter;
9175         int err;
9176
9177         if (ops->ndo_get_port_parent_id) {
9178                 err = ops->ndo_get_port_parent_id(dev, ppid);
9179                 if (err != -EOPNOTSUPP)
9180                         return err;
9181         }
9182
9183         err = devlink_compat_switch_id_get(dev, ppid);
9184         if (!recurse || err != -EOPNOTSUPP)
9185                 return err;
9186
9187         netdev_for_each_lower_dev(dev, lower_dev, iter) {
9188                 err = dev_get_port_parent_id(lower_dev, ppid, true);
9189                 if (err)
9190                         break;
9191                 if (!first.id_len)
9192                         first = *ppid;
9193                 else if (memcmp(&first, ppid, sizeof(*ppid)))
9194                         return -EOPNOTSUPP;
9195         }
9196
9197         return err;
9198 }
9199 EXPORT_SYMBOL(dev_get_port_parent_id);
9200
9201 /**
9202  *      netdev_port_same_parent_id - Indicate if two network devices have
9203  *      the same port parent identifier
9204  *      @a: first network device
9205  *      @b: second network device
9206  */
9207 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
9208 {
9209         struct netdev_phys_item_id a_id = { };
9210         struct netdev_phys_item_id b_id = { };
9211
9212         if (dev_get_port_parent_id(a, &a_id, true) ||
9213             dev_get_port_parent_id(b, &b_id, true))
9214                 return false;
9215
9216         return netdev_phys_item_id_same(&a_id, &b_id);
9217 }
9218 EXPORT_SYMBOL(netdev_port_same_parent_id);
9219
9220 /**
9221  *      dev_change_proto_down - update protocol port state information
9222  *      @dev: device
9223  *      @proto_down: new value
9224  *
9225  *      This info can be used by switch drivers to set the phys state of the
9226  *      port.
9227  */
9228 int dev_change_proto_down(struct net_device *dev, bool proto_down)
9229 {
9230         const struct net_device_ops *ops = dev->netdev_ops;
9231
9232         if (!ops->ndo_change_proto_down)
9233                 return -EOPNOTSUPP;
9234         if (!netif_device_present(dev))
9235                 return -ENODEV;
9236         return ops->ndo_change_proto_down(dev, proto_down);
9237 }
9238 EXPORT_SYMBOL(dev_change_proto_down);
9239
9240 /**
9241  *      dev_change_proto_down_generic - generic implementation for
9242  *      ndo_change_proto_down that sets carrier according to
9243  *      proto_down.
9244  *
9245  *      @dev: device
9246  *      @proto_down: new value
9247  */
9248 int dev_change_proto_down_generic(struct net_device *dev, bool proto_down)
9249 {
9250         if (proto_down)
9251                 netif_carrier_off(dev);
9252         else
9253                 netif_carrier_on(dev);
9254         dev->proto_down = proto_down;
9255         return 0;
9256 }
9257 EXPORT_SYMBOL(dev_change_proto_down_generic);
9258
9259 /**
9260  *      dev_change_proto_down_reason - proto down reason
9261  *
9262  *      @dev: device
9263  *      @mask: proto down mask
9264  *      @value: proto down value
9265  */
9266 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9267                                   u32 value)
9268 {
9269         int b;
9270
9271         if (!mask) {
9272                 dev->proto_down_reason = value;
9273         } else {
9274                 for_each_set_bit(b, &mask, 32) {
9275                         if (value & (1 << b))
9276                                 dev->proto_down_reason |= BIT(b);
9277                         else
9278                                 dev->proto_down_reason &= ~BIT(b);
9279                 }
9280         }
9281 }
9282 EXPORT_SYMBOL(dev_change_proto_down_reason);
9283
9284 struct bpf_xdp_link {
9285         struct bpf_link link;
9286         struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9287         int flags;
9288 };
9289
9290 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9291 {
9292         if (flags & XDP_FLAGS_HW_MODE)
9293                 return XDP_MODE_HW;
9294         if (flags & XDP_FLAGS_DRV_MODE)
9295                 return XDP_MODE_DRV;
9296         if (flags & XDP_FLAGS_SKB_MODE)
9297                 return XDP_MODE_SKB;
9298         return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9299 }
9300
9301 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9302 {
9303         switch (mode) {
9304         case XDP_MODE_SKB:
9305                 return generic_xdp_install;
9306         case XDP_MODE_DRV:
9307         case XDP_MODE_HW:
9308                 return dev->netdev_ops->ndo_bpf;
9309         default:
9310                 return NULL;
9311         }
9312 }
9313
9314 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9315                                          enum bpf_xdp_mode mode)
9316 {
9317         return dev->xdp_state[mode].link;
9318 }
9319
9320 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9321                                      enum bpf_xdp_mode mode)
9322 {
9323         struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9324
9325         if (link)
9326                 return link->link.prog;
9327         return dev->xdp_state[mode].prog;
9328 }
9329
9330 u8 dev_xdp_prog_count(struct net_device *dev)
9331 {
9332         u8 count = 0;
9333         int i;
9334
9335         for (i = 0; i < __MAX_XDP_MODE; i++)
9336                 if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9337                         count++;
9338         return count;
9339 }
9340 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9341
9342 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9343 {
9344         struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9345
9346         return prog ? prog->aux->id : 0;
9347 }
9348
9349 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9350                              struct bpf_xdp_link *link)
9351 {
9352         dev->xdp_state[mode].link = link;
9353         dev->xdp_state[mode].prog = NULL;
9354 }
9355
9356 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9357                              struct bpf_prog *prog)
9358 {
9359         dev->xdp_state[mode].link = NULL;
9360         dev->xdp_state[mode].prog = prog;
9361 }
9362
9363 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9364                            bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9365                            u32 flags, struct bpf_prog *prog)
9366 {
9367         struct netdev_bpf xdp;
9368         int err;
9369
9370         memset(&xdp, 0, sizeof(xdp));
9371         xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9372         xdp.extack = extack;
9373         xdp.flags = flags;
9374         xdp.prog = prog;
9375
9376         /* Drivers assume refcnt is already incremented (i.e, prog pointer is
9377          * "moved" into driver), so they don't increment it on their own, but
9378          * they do decrement refcnt when program is detached or replaced.
9379          * Given net_device also owns link/prog, we need to bump refcnt here
9380          * to prevent drivers from underflowing it.
9381          */
9382         if (prog)
9383                 bpf_prog_inc(prog);
9384         err = bpf_op(dev, &xdp);
9385         if (err) {
9386                 if (prog)
9387                         bpf_prog_put(prog);
9388                 return err;
9389         }
9390
9391         if (mode != XDP_MODE_HW)
9392                 bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9393
9394         return 0;
9395 }
9396
9397 static void dev_xdp_uninstall(struct net_device *dev)
9398 {
9399         struct bpf_xdp_link *link;
9400         struct bpf_prog *prog;
9401         enum bpf_xdp_mode mode;
9402         bpf_op_t bpf_op;
9403
9404         ASSERT_RTNL();
9405
9406         for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9407                 prog = dev_xdp_prog(dev, mode);
9408                 if (!prog)
9409                         continue;
9410
9411                 bpf_op = dev_xdp_bpf_op(dev, mode);
9412                 if (!bpf_op)
9413                         continue;
9414
9415                 WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9416
9417                 /* auto-detach link from net device */
9418                 link = dev_xdp_link(dev, mode);
9419                 if (link)
9420                         link->dev = NULL;
9421                 else
9422                         bpf_prog_put(prog);
9423
9424                 dev_xdp_set_link(dev, mode, NULL);
9425         }
9426 }
9427
9428 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9429                           struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9430                           struct bpf_prog *old_prog, u32 flags)
9431 {
9432         unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9433         struct bpf_prog *cur_prog;
9434         struct net_device *upper;
9435         struct list_head *iter;
9436         enum bpf_xdp_mode mode;
9437         bpf_op_t bpf_op;
9438         int err;
9439
9440         ASSERT_RTNL();
9441
9442         /* either link or prog attachment, never both */
9443         if (link && (new_prog || old_prog))
9444                 return -EINVAL;
9445         /* link supports only XDP mode flags */
9446         if (link && (flags & ~XDP_FLAGS_MODES)) {
9447                 NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9448                 return -EINVAL;
9449         }
9450         /* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9451         if (num_modes > 1) {
9452                 NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9453                 return -EINVAL;
9454         }
9455         /* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9456         if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9457                 NL_SET_ERR_MSG(extack,
9458                                "More than one program loaded, unset mode is ambiguous");
9459                 return -EINVAL;
9460         }
9461         /* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9462         if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9463                 NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9464                 return -EINVAL;
9465         }
9466
9467         mode = dev_xdp_mode(dev, flags);
9468         /* can't replace attached link */
9469         if (dev_xdp_link(dev, mode)) {
9470                 NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9471                 return -EBUSY;
9472         }
9473
9474         /* don't allow if an upper device already has a program */
9475         netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9476                 if (dev_xdp_prog_count(upper) > 0) {
9477                         NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9478                         return -EEXIST;
9479                 }
9480         }
9481
9482         cur_prog = dev_xdp_prog(dev, mode);
9483         /* can't replace attached prog with link */
9484         if (link && cur_prog) {
9485                 NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9486                 return -EBUSY;
9487         }
9488         if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9489                 NL_SET_ERR_MSG(extack, "Active program does not match expected");
9490                 return -EEXIST;
9491         }
9492
9493         /* put effective new program into new_prog */
9494         if (link)
9495                 new_prog = link->link.prog;
9496
9497         if (new_prog) {
9498                 bool offload = mode == XDP_MODE_HW;
9499                 enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9500                                                ? XDP_MODE_DRV : XDP_MODE_SKB;
9501
9502                 if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9503                         NL_SET_ERR_MSG(extack, "XDP program already attached");
9504                         return -EBUSY;
9505                 }
9506                 if (!offload && dev_xdp_prog(dev, other_mode)) {
9507                         NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9508                         return -EEXIST;
9509                 }
9510                 if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
9511                         NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
9512                         return -EINVAL;
9513                 }
9514                 if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9515                         NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9516                         return -EINVAL;
9517                 }
9518                 if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9519                         NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9520                         return -EINVAL;
9521                 }
9522         }
9523
9524         /* don't call drivers if the effective program didn't change */
9525         if (new_prog != cur_prog) {
9526                 bpf_op = dev_xdp_bpf_op(dev, mode);
9527                 if (!bpf_op) {
9528                         NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9529                         return -EOPNOTSUPP;
9530                 }
9531
9532                 err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9533                 if (err)
9534                         return err;
9535         }
9536
9537         if (link)
9538                 dev_xdp_set_link(dev, mode, link);
9539         else
9540                 dev_xdp_set_prog(dev, mode, new_prog);
9541         if (cur_prog)
9542                 bpf_prog_put(cur_prog);
9543
9544         return 0;
9545 }
9546
9547 static int dev_xdp_attach_link(struct net_device *dev,
9548                                struct netlink_ext_ack *extack,
9549                                struct bpf_xdp_link *link)
9550 {
9551         return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9552 }
9553
9554 static int dev_xdp_detach_link(struct net_device *dev,
9555                                struct netlink_ext_ack *extack,
9556                                struct bpf_xdp_link *link)
9557 {
9558         enum bpf_xdp_mode mode;
9559         bpf_op_t bpf_op;
9560
9561         ASSERT_RTNL();
9562
9563         mode = dev_xdp_mode(dev, link->flags);
9564         if (dev_xdp_link(dev, mode) != link)
9565                 return -EINVAL;
9566
9567         bpf_op = dev_xdp_bpf_op(dev, mode);
9568         WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9569         dev_xdp_set_link(dev, mode, NULL);
9570         return 0;
9571 }
9572
9573 static void bpf_xdp_link_release(struct bpf_link *link)
9574 {
9575         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9576
9577         rtnl_lock();
9578
9579         /* if racing with net_device's tear down, xdp_link->dev might be
9580          * already NULL, in which case link was already auto-detached
9581          */
9582         if (xdp_link->dev) {
9583                 WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9584                 xdp_link->dev = NULL;
9585         }
9586
9587         rtnl_unlock();
9588 }
9589
9590 static int bpf_xdp_link_detach(struct bpf_link *link)
9591 {
9592         bpf_xdp_link_release(link);
9593         return 0;
9594 }
9595
9596 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9597 {
9598         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9599
9600         kfree(xdp_link);
9601 }
9602
9603 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9604                                      struct seq_file *seq)
9605 {
9606         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9607         u32 ifindex = 0;
9608
9609         rtnl_lock();
9610         if (xdp_link->dev)
9611                 ifindex = xdp_link->dev->ifindex;
9612         rtnl_unlock();
9613
9614         seq_printf(seq, "ifindex:\t%u\n", ifindex);
9615 }
9616
9617 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9618                                        struct bpf_link_info *info)
9619 {
9620         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9621         u32 ifindex = 0;
9622
9623         rtnl_lock();
9624         if (xdp_link->dev)
9625                 ifindex = xdp_link->dev->ifindex;
9626         rtnl_unlock();
9627
9628         info->xdp.ifindex = ifindex;
9629         return 0;
9630 }
9631
9632 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9633                                struct bpf_prog *old_prog)
9634 {
9635         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9636         enum bpf_xdp_mode mode;
9637         bpf_op_t bpf_op;
9638         int err = 0;
9639
9640         rtnl_lock();
9641
9642         /* link might have been auto-released already, so fail */
9643         if (!xdp_link->dev) {
9644                 err = -ENOLINK;
9645                 goto out_unlock;
9646         }
9647
9648         if (old_prog && link->prog != old_prog) {
9649                 err = -EPERM;
9650                 goto out_unlock;
9651         }
9652         old_prog = link->prog;
9653         if (old_prog == new_prog) {
9654                 /* no-op, don't disturb drivers */
9655                 bpf_prog_put(new_prog);
9656                 goto out_unlock;
9657         }
9658
9659         mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9660         bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9661         err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9662                               xdp_link->flags, new_prog);
9663         if (err)
9664                 goto out_unlock;
9665
9666         old_prog = xchg(&link->prog, new_prog);
9667         bpf_prog_put(old_prog);
9668
9669 out_unlock:
9670         rtnl_unlock();
9671         return err;
9672 }
9673
9674 static const struct bpf_link_ops bpf_xdp_link_lops = {
9675         .release = bpf_xdp_link_release,
9676         .dealloc = bpf_xdp_link_dealloc,
9677         .detach = bpf_xdp_link_detach,
9678         .show_fdinfo = bpf_xdp_link_show_fdinfo,
9679         .fill_link_info = bpf_xdp_link_fill_link_info,
9680         .update_prog = bpf_xdp_link_update,
9681 };
9682
9683 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9684 {
9685         struct net *net = current->nsproxy->net_ns;
9686         struct bpf_link_primer link_primer;
9687         struct bpf_xdp_link *link;
9688         struct net_device *dev;
9689         int err, fd;
9690
9691         rtnl_lock();
9692         dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9693         if (!dev) {
9694                 rtnl_unlock();
9695                 return -EINVAL;
9696         }
9697
9698         link = kzalloc(sizeof(*link), GFP_USER);
9699         if (!link) {
9700                 err = -ENOMEM;
9701                 goto unlock;
9702         }
9703
9704         bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9705         link->dev = dev;
9706         link->flags = attr->link_create.flags;
9707
9708         err = bpf_link_prime(&link->link, &link_primer);
9709         if (err) {
9710                 kfree(link);
9711                 goto unlock;
9712         }
9713
9714         err = dev_xdp_attach_link(dev, NULL, link);
9715         rtnl_unlock();
9716
9717         if (err) {
9718                 link->dev = NULL;
9719                 bpf_link_cleanup(&link_primer);
9720                 goto out_put_dev;
9721         }
9722
9723         fd = bpf_link_settle(&link_primer);
9724         /* link itself doesn't hold dev's refcnt to not complicate shutdown */
9725         dev_put(dev);
9726         return fd;
9727
9728 unlock:
9729         rtnl_unlock();
9730
9731 out_put_dev:
9732         dev_put(dev);
9733         return err;
9734 }
9735
9736 /**
9737  *      dev_change_xdp_fd - set or clear a bpf program for a device rx path
9738  *      @dev: device
9739  *      @extack: netlink extended ack
9740  *      @fd: new program fd or negative value to clear
9741  *      @expected_fd: old program fd that userspace expects to replace or clear
9742  *      @flags: xdp-related flags
9743  *
9744  *      Set or clear a bpf program for a device
9745  */
9746 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9747                       int fd, int expected_fd, u32 flags)
9748 {
9749         enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9750         struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9751         int err;
9752
9753         ASSERT_RTNL();
9754
9755         if (fd >= 0) {
9756                 new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9757                                                  mode != XDP_MODE_SKB);
9758                 if (IS_ERR(new_prog))
9759                         return PTR_ERR(new_prog);
9760         }
9761
9762         if (expected_fd >= 0) {
9763                 old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9764                                                  mode != XDP_MODE_SKB);
9765                 if (IS_ERR(old_prog)) {
9766                         err = PTR_ERR(old_prog);
9767                         old_prog = NULL;
9768                         goto err_out;
9769                 }
9770         }
9771
9772         err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9773
9774 err_out:
9775         if (err && new_prog)
9776                 bpf_prog_put(new_prog);
9777         if (old_prog)
9778                 bpf_prog_put(old_prog);
9779         return err;
9780 }
9781
9782 /**
9783  *      dev_new_index   -       allocate an ifindex
9784  *      @net: the applicable net namespace
9785  *
9786  *      Returns a suitable unique value for a new device interface
9787  *      number.  The caller must hold the rtnl semaphore or the
9788  *      dev_base_lock to be sure it remains unique.
9789  */
9790 static int dev_new_index(struct net *net)
9791 {
9792         int ifindex = net->ifindex;
9793
9794         for (;;) {
9795                 if (++ifindex <= 0)
9796                         ifindex = 1;
9797                 if (!__dev_get_by_index(net, ifindex))
9798                         return net->ifindex = ifindex;
9799         }
9800 }
9801
9802 /* Delayed registration/unregisteration */
9803 static LIST_HEAD(net_todo_list);
9804 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9805
9806 static void net_set_todo(struct net_device *dev)
9807 {
9808         list_add_tail(&dev->todo_list, &net_todo_list);
9809         dev_net(dev)->dev_unreg_count++;
9810 }
9811
9812 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9813         struct net_device *upper, netdev_features_t features)
9814 {
9815         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9816         netdev_features_t feature;
9817         int feature_bit;
9818
9819         for_each_netdev_feature(upper_disables, feature_bit) {
9820                 feature = __NETIF_F_BIT(feature_bit);
9821                 if (!(upper->wanted_features & feature)
9822                     && (features & feature)) {
9823                         netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9824                                    &feature, upper->name);
9825                         features &= ~feature;
9826                 }
9827         }
9828
9829         return features;
9830 }
9831
9832 static void netdev_sync_lower_features(struct net_device *upper,
9833         struct net_device *lower, netdev_features_t features)
9834 {
9835         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9836         netdev_features_t feature;
9837         int feature_bit;
9838
9839         for_each_netdev_feature(upper_disables, feature_bit) {
9840                 feature = __NETIF_F_BIT(feature_bit);
9841                 if (!(features & feature) && (lower->features & feature)) {
9842                         netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9843                                    &feature, lower->name);
9844                         lower->wanted_features &= ~feature;
9845                         __netdev_update_features(lower);
9846
9847                         if (unlikely(lower->features & feature))
9848                                 netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9849                                             &feature, lower->name);
9850                         else
9851                                 netdev_features_change(lower);
9852                 }
9853         }
9854 }
9855
9856 static netdev_features_t netdev_fix_features(struct net_device *dev,
9857         netdev_features_t features)
9858 {
9859         /* Fix illegal checksum combinations */
9860         if ((features & NETIF_F_HW_CSUM) &&
9861             (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9862                 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9863                 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9864         }
9865
9866         /* TSO requires that SG is present as well. */
9867         if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9868                 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9869                 features &= ~NETIF_F_ALL_TSO;
9870         }
9871
9872         if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9873                                         !(features & NETIF_F_IP_CSUM)) {
9874                 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9875                 features &= ~NETIF_F_TSO;
9876                 features &= ~NETIF_F_TSO_ECN;
9877         }
9878
9879         if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9880                                          !(features & NETIF_F_IPV6_CSUM)) {
9881                 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9882                 features &= ~NETIF_F_TSO6;
9883         }
9884
9885         /* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9886         if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9887                 features &= ~NETIF_F_TSO_MANGLEID;
9888
9889         /* TSO ECN requires that TSO is present as well. */
9890         if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9891                 features &= ~NETIF_F_TSO_ECN;
9892
9893         /* Software GSO depends on SG. */
9894         if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9895                 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9896                 features &= ~NETIF_F_GSO;
9897         }
9898
9899         /* GSO partial features require GSO partial be set */
9900         if ((features & dev->gso_partial_features) &&
9901             !(features & NETIF_F_GSO_PARTIAL)) {
9902                 netdev_dbg(dev,
9903                            "Dropping partially supported GSO features since no GSO partial.\n");
9904                 features &= ~dev->gso_partial_features;
9905         }
9906
9907         if (!(features & NETIF_F_RXCSUM)) {
9908                 /* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9909                  * successfully merged by hardware must also have the
9910                  * checksum verified by hardware.  If the user does not
9911                  * want to enable RXCSUM, logically, we should disable GRO_HW.
9912                  */
9913                 if (features & NETIF_F_GRO_HW) {
9914                         netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9915                         features &= ~NETIF_F_GRO_HW;
9916                 }
9917         }
9918
9919         /* LRO/HW-GRO features cannot be combined with RX-FCS */
9920         if (features & NETIF_F_RXFCS) {
9921                 if (features & NETIF_F_LRO) {
9922                         netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9923                         features &= ~NETIF_F_LRO;
9924                 }
9925
9926                 if (features & NETIF_F_GRO_HW) {
9927                         netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9928                         features &= ~NETIF_F_GRO_HW;
9929                 }
9930         }
9931
9932         if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9933                 netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9934                 features &= ~NETIF_F_LRO;
9935         }
9936
9937         if (features & NETIF_F_HW_TLS_TX) {
9938                 bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9939                         (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9940                 bool hw_csum = features & NETIF_F_HW_CSUM;
9941
9942                 if (!ip_csum && !hw_csum) {
9943                         netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9944                         features &= ~NETIF_F_HW_TLS_TX;
9945                 }
9946         }
9947
9948         if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9949                 netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9950                 features &= ~NETIF_F_HW_TLS_RX;
9951         }
9952
9953         return features;
9954 }
9955
9956 int __netdev_update_features(struct net_device *dev)
9957 {
9958         struct net_device *upper, *lower;
9959         netdev_features_t features;
9960         struct list_head *iter;
9961         int err = -1;
9962
9963         ASSERT_RTNL();
9964
9965         features = netdev_get_wanted_features(dev);
9966
9967         if (dev->netdev_ops->ndo_fix_features)
9968                 features = dev->netdev_ops->ndo_fix_features(dev, features);
9969
9970         /* driver might be less strict about feature dependencies */
9971         features = netdev_fix_features(dev, features);
9972
9973         /* some features can't be enabled if they're off on an upper device */
9974         netdev_for_each_upper_dev_rcu(dev, upper, iter)
9975                 features = netdev_sync_upper_features(dev, upper, features);
9976
9977         if (dev->features == features)
9978                 goto sync_lower;
9979
9980         netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9981                 &dev->features, &features);
9982
9983         if (dev->netdev_ops->ndo_set_features)
9984                 err = dev->netdev_ops->ndo_set_features(dev, features);
9985         else
9986                 err = 0;
9987
9988         if (unlikely(err < 0)) {
9989                 netdev_err(dev,
9990                         "set_features() failed (%d); wanted %pNF, left %pNF\n",
9991                         err, &features, &dev->features);
9992                 /* return non-0 since some features might have changed and
9993                  * it's better to fire a spurious notification than miss it
9994                  */
9995                 return -1;
9996         }
9997
9998 sync_lower:
9999         /* some features must be disabled on lower devices when disabled
10000          * on an upper device (think: bonding master or bridge)
10001          */
10002         netdev_for_each_lower_dev(dev, lower, iter)
10003                 netdev_sync_lower_features(dev, lower, features);
10004
10005         if (!err) {
10006                 netdev_features_t diff = features ^ dev->features;
10007
10008                 if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
10009                         /* udp_tunnel_{get,drop}_rx_info both need
10010                          * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
10011                          * device, or they won't do anything.
10012                          * Thus we need to update dev->features
10013                          * *before* calling udp_tunnel_get_rx_info,
10014                          * but *after* calling udp_tunnel_drop_rx_info.
10015                          */
10016                         if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
10017                                 dev->features = features;
10018                                 udp_tunnel_get_rx_info(dev);
10019                         } else {
10020                                 udp_tunnel_drop_rx_info(dev);
10021                         }
10022                 }
10023
10024                 if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
10025                         if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
10026                                 dev->features = features;
10027                                 err |= vlan_get_rx_ctag_filter_info(dev);
10028                         } else {
10029                                 vlan_drop_rx_ctag_filter_info(dev);
10030                         }
10031                 }
10032
10033                 if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
10034                         if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
10035                                 dev->features = features;
10036                                 err |= vlan_get_rx_stag_filter_info(dev);
10037                         } else {
10038                                 vlan_drop_rx_stag_filter_info(dev);
10039                         }
10040                 }
10041
10042                 dev->features = features;
10043         }
10044
10045         return err < 0 ? 0 : 1;
10046 }
10047
10048 /**
10049  *      netdev_update_features - recalculate device features
10050  *      @dev: the device to check
10051  *
10052  *      Recalculate dev->features set and send notifications if it
10053  *      has changed. Should be called after driver or hardware dependent
10054  *      conditions might have changed that influence the features.
10055  */
10056 void netdev_update_features(struct net_device *dev)
10057 {
10058         if (__netdev_update_features(dev))
10059                 netdev_features_change(dev);
10060 }
10061 EXPORT_SYMBOL(netdev_update_features);
10062
10063 /**
10064  *      netdev_change_features - recalculate device features
10065  *      @dev: the device to check
10066  *
10067  *      Recalculate dev->features set and send notifications even
10068  *      if they have not changed. Should be called instead of
10069  *      netdev_update_features() if also dev->vlan_features might
10070  *      have changed to allow the changes to be propagated to stacked
10071  *      VLAN devices.
10072  */
10073 void netdev_change_features(struct net_device *dev)
10074 {
10075         __netdev_update_features(dev);
10076         netdev_features_change(dev);
10077 }
10078 EXPORT_SYMBOL(netdev_change_features);
10079
10080 /**
10081  *      netif_stacked_transfer_operstate -      transfer operstate
10082  *      @rootdev: the root or lower level device to transfer state from
10083  *      @dev: the device to transfer operstate to
10084  *
10085  *      Transfer operational state from root to device. This is normally
10086  *      called when a stacking relationship exists between the root
10087  *      device and the device(a leaf device).
10088  */
10089 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
10090                                         struct net_device *dev)
10091 {
10092         if (rootdev->operstate == IF_OPER_DORMANT)
10093                 netif_dormant_on(dev);
10094         else
10095                 netif_dormant_off(dev);
10096
10097         if (rootdev->operstate == IF_OPER_TESTING)
10098                 netif_testing_on(dev);
10099         else
10100                 netif_testing_off(dev);
10101
10102         if (netif_carrier_ok(rootdev))
10103                 netif_carrier_on(dev);
10104         else
10105                 netif_carrier_off(dev);
10106 }
10107 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
10108
10109 static int netif_alloc_rx_queues(struct net_device *dev)
10110 {
10111         unsigned int i, count = dev->num_rx_queues;
10112         struct netdev_rx_queue *rx;
10113         size_t sz = count * sizeof(*rx);
10114         int err = 0;
10115
10116         BUG_ON(count < 1);
10117
10118         rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10119         if (!rx)
10120                 return -ENOMEM;
10121
10122         dev->_rx = rx;
10123
10124         for (i = 0; i < count; i++) {
10125                 rx[i].dev = dev;
10126
10127                 /* XDP RX-queue setup */
10128                 err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
10129                 if (err < 0)
10130                         goto err_rxq_info;
10131         }
10132         return 0;
10133
10134 err_rxq_info:
10135         /* Rollback successful reg's and free other resources */
10136         while (i--)
10137                 xdp_rxq_info_unreg(&rx[i].xdp_rxq);
10138         kvfree(dev->_rx);
10139         dev->_rx = NULL;
10140         return err;
10141 }
10142
10143 static void netif_free_rx_queues(struct net_device *dev)
10144 {
10145         unsigned int i, count = dev->num_rx_queues;
10146
10147         /* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
10148         if (!dev->_rx)
10149                 return;
10150
10151         for (i = 0; i < count; i++)
10152                 xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
10153
10154         kvfree(dev->_rx);
10155 }
10156
10157 static void netdev_init_one_queue(struct net_device *dev,
10158                                   struct netdev_queue *queue, void *_unused)
10159 {
10160         /* Initialize queue lock */
10161         spin_lock_init(&queue->_xmit_lock);
10162         netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
10163         queue->xmit_lock_owner = -1;
10164         netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
10165         queue->dev = dev;
10166 #ifdef CONFIG_BQL
10167         dql_init(&queue->dql, HZ);
10168 #endif
10169 }
10170
10171 static void netif_free_tx_queues(struct net_device *dev)
10172 {
10173         kvfree(dev->_tx);
10174 }
10175
10176 static int netif_alloc_netdev_queues(struct net_device *dev)
10177 {
10178         unsigned int count = dev->num_tx_queues;
10179         struct netdev_queue *tx;
10180         size_t sz = count * sizeof(*tx);
10181
10182         if (count < 1 || count > 0xffff)
10183                 return -EINVAL;
10184
10185         tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10186         if (!tx)
10187                 return -ENOMEM;
10188
10189         dev->_tx = tx;
10190
10191         netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
10192         spin_lock_init(&dev->tx_global_lock);
10193
10194         return 0;
10195 }
10196
10197 void netif_tx_stop_all_queues(struct net_device *dev)
10198 {
10199         unsigned int i;
10200
10201         for (i = 0; i < dev->num_tx_queues; i++) {
10202                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
10203
10204                 netif_tx_stop_queue(txq);
10205         }
10206 }
10207 EXPORT_SYMBOL(netif_tx_stop_all_queues);
10208
10209 /**
10210  *      register_netdevice      - register a network device
10211  *      @dev: device to register
10212  *
10213  *      Take a completed network device structure and add it to the kernel
10214  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10215  *      chain. 0 is returned on success. A negative errno code is returned
10216  *      on a failure to set up the device, or if the name is a duplicate.
10217  *
10218  *      Callers must hold the rtnl semaphore. You may want
10219  *      register_netdev() instead of this.
10220  *
10221  *      BUGS:
10222  *      The locking appears insufficient to guarantee two parallel registers
10223  *      will not get the same name.
10224  */
10225
10226 int register_netdevice(struct net_device *dev)
10227 {
10228         int ret;
10229         struct net *net = dev_net(dev);
10230
10231         BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
10232                      NETDEV_FEATURE_COUNT);
10233         BUG_ON(dev_boot_phase);
10234         ASSERT_RTNL();
10235
10236         might_sleep();
10237
10238         /* When net_device's are persistent, this will be fatal. */
10239         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
10240         BUG_ON(!net);
10241
10242         ret = ethtool_check_ops(dev->ethtool_ops);
10243         if (ret)
10244                 return ret;
10245
10246         spin_lock_init(&dev->addr_list_lock);
10247         netdev_set_addr_lockdep_class(dev);
10248
10249         ret = dev_get_valid_name(net, dev, dev->name);
10250         if (ret < 0)
10251                 goto out;
10252
10253         ret = -ENOMEM;
10254         dev->name_node = netdev_name_node_head_alloc(dev);
10255         if (!dev->name_node)
10256                 goto out;
10257
10258         /* Init, if this function is available */
10259         if (dev->netdev_ops->ndo_init) {
10260                 ret = dev->netdev_ops->ndo_init(dev);
10261                 if (ret) {
10262                         if (ret > 0)
10263                                 ret = -EIO;
10264                         goto err_free_name;
10265                 }
10266         }
10267
10268         if (((dev->hw_features | dev->features) &
10269              NETIF_F_HW_VLAN_CTAG_FILTER) &&
10270             (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10271              !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10272                 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10273                 ret = -EINVAL;
10274                 goto err_uninit;
10275         }
10276
10277         ret = -EBUSY;
10278         if (!dev->ifindex)
10279                 dev->ifindex = dev_new_index(net);
10280         else if (__dev_get_by_index(net, dev->ifindex))
10281                 goto err_uninit;
10282
10283         /* Transfer changeable features to wanted_features and enable
10284          * software offloads (GSO and GRO).
10285          */
10286         dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10287         dev->features |= NETIF_F_SOFT_FEATURES;
10288
10289         if (dev->udp_tunnel_nic_info) {
10290                 dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10291                 dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10292         }
10293
10294         dev->wanted_features = dev->features & dev->hw_features;
10295
10296         if (!(dev->flags & IFF_LOOPBACK))
10297                 dev->hw_features |= NETIF_F_NOCACHE_COPY;
10298
10299         /* If IPv4 TCP segmentation offload is supported we should also
10300          * allow the device to enable segmenting the frame with the option
10301          * of ignoring a static IP ID value.  This doesn't enable the
10302          * feature itself but allows the user to enable it later.
10303          */
10304         if (dev->hw_features & NETIF_F_TSO)
10305                 dev->hw_features |= NETIF_F_TSO_MANGLEID;
10306         if (dev->vlan_features & NETIF_F_TSO)
10307                 dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10308         if (dev->mpls_features & NETIF_F_TSO)
10309                 dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10310         if (dev->hw_enc_features & NETIF_F_TSO)
10311                 dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10312
10313         /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10314          */
10315         dev->vlan_features |= NETIF_F_HIGHDMA;
10316
10317         /* Make NETIF_F_SG inheritable to tunnel devices.
10318          */
10319         dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10320
10321         /* Make NETIF_F_SG inheritable to MPLS.
10322          */
10323         dev->mpls_features |= NETIF_F_SG;
10324
10325         ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10326         ret = notifier_to_errno(ret);
10327         if (ret)
10328                 goto err_uninit;
10329
10330         ret = netdev_register_kobject(dev);
10331         if (ret) {
10332                 dev->reg_state = NETREG_UNREGISTERED;
10333                 goto err_uninit;
10334         }
10335         dev->reg_state = NETREG_REGISTERED;
10336
10337         __netdev_update_features(dev);
10338
10339         /*
10340          *      Default initial state at registry is that the
10341          *      device is present.
10342          */
10343
10344         set_bit(__LINK_STATE_PRESENT, &dev->state);
10345
10346         linkwatch_init_dev(dev);
10347
10348         dev_init_scheduler(dev);
10349         dev_hold(dev);
10350         list_netdevice(dev);
10351         add_device_randomness(dev->dev_addr, dev->addr_len);
10352
10353         /* If the device has permanent device address, driver should
10354          * set dev_addr and also addr_assign_type should be set to
10355          * NET_ADDR_PERM (default value).
10356          */
10357         if (dev->addr_assign_type == NET_ADDR_PERM)
10358                 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10359
10360         /* Notify protocols, that a new device appeared. */
10361         ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10362         ret = notifier_to_errno(ret);
10363         if (ret) {
10364                 /* Expect explicit free_netdev() on failure */
10365                 dev->needs_free_netdev = false;
10366                 unregister_netdevice_queue(dev, NULL);
10367                 goto out;
10368         }
10369         /*
10370          *      Prevent userspace races by waiting until the network
10371          *      device is fully setup before sending notifications.
10372          */
10373         if (!dev->rtnl_link_ops ||
10374             dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10375                 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
10376
10377 out:
10378         return ret;
10379
10380 err_uninit:
10381         if (dev->netdev_ops->ndo_uninit)
10382                 dev->netdev_ops->ndo_uninit(dev);
10383         if (dev->priv_destructor)
10384                 dev->priv_destructor(dev);
10385 err_free_name:
10386         netdev_name_node_free(dev->name_node);
10387         goto out;
10388 }
10389 EXPORT_SYMBOL(register_netdevice);
10390
10391 /**
10392  *      init_dummy_netdev       - init a dummy network device for NAPI
10393  *      @dev: device to init
10394  *
10395  *      This takes a network device structure and initialize the minimum
10396  *      amount of fields so it can be used to schedule NAPI polls without
10397  *      registering a full blown interface. This is to be used by drivers
10398  *      that need to tie several hardware interfaces to a single NAPI
10399  *      poll scheduler due to HW limitations.
10400  */
10401 int init_dummy_netdev(struct net_device *dev)
10402 {
10403         /* Clear everything. Note we don't initialize spinlocks
10404          * are they aren't supposed to be taken by any of the
10405          * NAPI code and this dummy netdev is supposed to be
10406          * only ever used for NAPI polls
10407          */
10408         memset(dev, 0, sizeof(struct net_device));
10409
10410         /* make sure we BUG if trying to hit standard
10411          * register/unregister code path
10412          */
10413         dev->reg_state = NETREG_DUMMY;
10414
10415         /* NAPI wants this */
10416         INIT_LIST_HEAD(&dev->napi_list);
10417
10418         /* a dummy interface is started by default */
10419         set_bit(__LINK_STATE_PRESENT, &dev->state);
10420         set_bit(__LINK_STATE_START, &dev->state);
10421
10422         /* napi_busy_loop stats accounting wants this */
10423         dev_net_set(dev, &init_net);
10424
10425         /* Note : We dont allocate pcpu_refcnt for dummy devices,
10426          * because users of this 'device' dont need to change
10427          * its refcount.
10428          */
10429
10430         return 0;
10431 }
10432 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10433
10434
10435 /**
10436  *      register_netdev - register a network device
10437  *      @dev: device to register
10438  *
10439  *      Take a completed network device structure and add it to the kernel
10440  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10441  *      chain. 0 is returned on success. A negative errno code is returned
10442  *      on a failure to set up the device, or if the name is a duplicate.
10443  *
10444  *      This is a wrapper around register_netdevice that takes the rtnl semaphore
10445  *      and expands the device name if you passed a format string to
10446  *      alloc_netdev.
10447  */
10448 int register_netdev(struct net_device *dev)
10449 {
10450         int err;
10451
10452         if (rtnl_lock_killable())
10453                 return -EINTR;
10454         err = register_netdevice(dev);
10455         rtnl_unlock();
10456         return err;
10457 }
10458 EXPORT_SYMBOL(register_netdev);
10459
10460 int netdev_refcnt_read(const struct net_device *dev)
10461 {
10462 #ifdef CONFIG_PCPU_DEV_REFCNT
10463         int i, refcnt = 0;
10464
10465         for_each_possible_cpu(i)
10466                 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10467         return refcnt;
10468 #else
10469         return refcount_read(&dev->dev_refcnt);
10470 #endif
10471 }
10472 EXPORT_SYMBOL(netdev_refcnt_read);
10473
10474 int netdev_unregister_timeout_secs __read_mostly = 10;
10475
10476 #define WAIT_REFS_MIN_MSECS 1
10477 #define WAIT_REFS_MAX_MSECS 250
10478 /**
10479  * netdev_wait_allrefs - wait until all references are gone.
10480  * @dev: target net_device
10481  *
10482  * This is called when unregistering network devices.
10483  *
10484  * Any protocol or device that holds a reference should register
10485  * for netdevice notification, and cleanup and put back the
10486  * reference if they receive an UNREGISTER event.
10487  * We can get stuck here if buggy protocols don't correctly
10488  * call dev_put.
10489  */
10490 static void netdev_wait_allrefs(struct net_device *dev)
10491 {
10492         unsigned long rebroadcast_time, warning_time;
10493         int wait = 0, refcnt;
10494
10495         linkwatch_forget_dev(dev);
10496
10497         rebroadcast_time = warning_time = jiffies;
10498         refcnt = netdev_refcnt_read(dev);
10499
10500         while (refcnt != 1) {
10501                 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10502                         rtnl_lock();
10503
10504                         /* Rebroadcast unregister notification */
10505                         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10506
10507                         __rtnl_unlock();
10508                         rcu_barrier();
10509                         rtnl_lock();
10510
10511                         if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10512                                      &dev->state)) {
10513                                 /* We must not have linkwatch events
10514                                  * pending on unregister. If this
10515                                  * happens, we simply run the queue
10516                                  * unscheduled, resulting in a noop
10517                                  * for this device.
10518                                  */
10519                                 linkwatch_run_queue();
10520                         }
10521
10522                         __rtnl_unlock();
10523
10524                         rebroadcast_time = jiffies;
10525                 }
10526
10527                 if (!wait) {
10528                         rcu_barrier();
10529                         wait = WAIT_REFS_MIN_MSECS;
10530                 } else {
10531                         msleep(wait);
10532                         wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10533                 }
10534
10535                 refcnt = netdev_refcnt_read(dev);
10536
10537                 if (refcnt != 1 &&
10538                     time_after(jiffies, warning_time +
10539                                netdev_unregister_timeout_secs * HZ)) {
10540                         pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10541                                  dev->name, refcnt);
10542                         warning_time = jiffies;
10543                 }
10544         }
10545 }
10546
10547 /* The sequence is:
10548  *
10549  *      rtnl_lock();
10550  *      ...
10551  *      register_netdevice(x1);
10552  *      register_netdevice(x2);
10553  *      ...
10554  *      unregister_netdevice(y1);
10555  *      unregister_netdevice(y2);
10556  *      ...
10557  *      rtnl_unlock();
10558  *      free_netdev(y1);
10559  *      free_netdev(y2);
10560  *
10561  * We are invoked by rtnl_unlock().
10562  * This allows us to deal with problems:
10563  * 1) We can delete sysfs objects which invoke hotplug
10564  *    without deadlocking with linkwatch via keventd.
10565  * 2) Since we run with the RTNL semaphore not held, we can sleep
10566  *    safely in order to wait for the netdev refcnt to drop to zero.
10567  *
10568  * We must not return until all unregister events added during
10569  * the interval the lock was held have been completed.
10570  */
10571 void netdev_run_todo(void)
10572 {
10573         struct list_head list;
10574 #ifdef CONFIG_LOCKDEP
10575         struct list_head unlink_list;
10576
10577         list_replace_init(&net_unlink_list, &unlink_list);
10578
10579         while (!list_empty(&unlink_list)) {
10580                 struct net_device *dev = list_first_entry(&unlink_list,
10581                                                           struct net_device,
10582                                                           unlink_list);
10583                 list_del_init(&dev->unlink_list);
10584                 dev->nested_level = dev->lower_level - 1;
10585         }
10586 #endif
10587
10588         /* Snapshot list, allow later requests */
10589         list_replace_init(&net_todo_list, &list);
10590
10591         __rtnl_unlock();
10592
10593
10594         /* Wait for rcu callbacks to finish before next phase */
10595         if (!list_empty(&list))
10596                 rcu_barrier();
10597
10598         while (!list_empty(&list)) {
10599                 struct net_device *dev
10600                         = list_first_entry(&list, struct net_device, todo_list);
10601                 list_del(&dev->todo_list);
10602
10603                 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10604                         pr_err("network todo '%s' but state %d\n",
10605                                dev->name, dev->reg_state);
10606                         dump_stack();
10607                         continue;
10608                 }
10609
10610                 dev->reg_state = NETREG_UNREGISTERED;
10611
10612                 netdev_wait_allrefs(dev);
10613
10614                 /* paranoia */
10615                 BUG_ON(netdev_refcnt_read(dev) != 1);
10616                 BUG_ON(!list_empty(&dev->ptype_all));
10617                 BUG_ON(!list_empty(&dev->ptype_specific));
10618                 WARN_ON(rcu_access_pointer(dev->ip_ptr));
10619                 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10620 #if IS_ENABLED(CONFIG_DECNET)
10621                 WARN_ON(dev->dn_ptr);
10622 #endif
10623                 if (dev->priv_destructor)
10624                         dev->priv_destructor(dev);
10625                 if (dev->needs_free_netdev)
10626                         free_netdev(dev);
10627
10628                 /* Report a network device has been unregistered */
10629                 rtnl_lock();
10630                 dev_net(dev)->dev_unreg_count--;
10631                 __rtnl_unlock();
10632                 wake_up(&netdev_unregistering_wq);
10633
10634                 /* Free network device */
10635                 kobject_put(&dev->dev.kobj);
10636         }
10637 }
10638
10639 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10640  * all the same fields in the same order as net_device_stats, with only
10641  * the type differing, but rtnl_link_stats64 may have additional fields
10642  * at the end for newer counters.
10643  */
10644 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10645                              const struct net_device_stats *netdev_stats)
10646 {
10647 #if BITS_PER_LONG == 64
10648         BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats));
10649         memcpy(stats64, netdev_stats, sizeof(*netdev_stats));
10650         /* zero out counters that only exist in rtnl_link_stats64 */
10651         memset((char *)stats64 + sizeof(*netdev_stats), 0,
10652                sizeof(*stats64) - sizeof(*netdev_stats));
10653 #else
10654         size_t i, n = sizeof(*netdev_stats) / sizeof(unsigned long);
10655         const unsigned long *src = (const unsigned long *)netdev_stats;
10656         u64 *dst = (u64 *)stats64;
10657
10658         BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10659         for (i = 0; i < n; i++)
10660                 dst[i] = src[i];
10661         /* zero out counters that only exist in rtnl_link_stats64 */
10662         memset((char *)stats64 + n * sizeof(u64), 0,
10663                sizeof(*stats64) - n * sizeof(u64));
10664 #endif
10665 }
10666 EXPORT_SYMBOL(netdev_stats_to_stats64);
10667
10668 /**
10669  *      dev_get_stats   - get network device statistics
10670  *      @dev: device to get statistics from
10671  *      @storage: place to store stats
10672  *
10673  *      Get network statistics from device. Return @storage.
10674  *      The device driver may provide its own method by setting
10675  *      dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10676  *      otherwise the internal statistics structure is used.
10677  */
10678 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10679                                         struct rtnl_link_stats64 *storage)
10680 {
10681         const struct net_device_ops *ops = dev->netdev_ops;
10682
10683         if (ops->ndo_get_stats64) {
10684                 memset(storage, 0, sizeof(*storage));
10685                 ops->ndo_get_stats64(dev, storage);
10686         } else if (ops->ndo_get_stats) {
10687                 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10688         } else {
10689                 netdev_stats_to_stats64(storage, &dev->stats);
10690         }
10691         storage->rx_dropped += (unsigned long)atomic_long_read(&dev->rx_dropped);
10692         storage->tx_dropped += (unsigned long)atomic_long_read(&dev->tx_dropped);
10693         storage->rx_nohandler += (unsigned long)atomic_long_read(&dev->rx_nohandler);
10694         return storage;
10695 }
10696 EXPORT_SYMBOL(dev_get_stats);
10697
10698 /**
10699  *      dev_fetch_sw_netstats - get per-cpu network device statistics
10700  *      @s: place to store stats
10701  *      @netstats: per-cpu network stats to read from
10702  *
10703  *      Read per-cpu network statistics and populate the related fields in @s.
10704  */
10705 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10706                            const struct pcpu_sw_netstats __percpu *netstats)
10707 {
10708         int cpu;
10709
10710         for_each_possible_cpu(cpu) {
10711                 const struct pcpu_sw_netstats *stats;
10712                 struct pcpu_sw_netstats tmp;
10713                 unsigned int start;
10714
10715                 stats = per_cpu_ptr(netstats, cpu);
10716                 do {
10717                         start = u64_stats_fetch_begin_irq(&stats->syncp);
10718                         tmp.rx_packets = stats->rx_packets;
10719                         tmp.rx_bytes   = stats->rx_bytes;
10720                         tmp.tx_packets = stats->tx_packets;
10721                         tmp.tx_bytes   = stats->tx_bytes;
10722                 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
10723
10724                 s->rx_packets += tmp.rx_packets;
10725                 s->rx_bytes   += tmp.rx_bytes;
10726                 s->tx_packets += tmp.tx_packets;
10727                 s->tx_bytes   += tmp.tx_bytes;
10728         }
10729 }
10730 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10731
10732 /**
10733  *      dev_get_tstats64 - ndo_get_stats64 implementation
10734  *      @dev: device to get statistics from
10735  *      @s: place to store stats
10736  *
10737  *      Populate @s from dev->stats and dev->tstats. Can be used as
10738  *      ndo_get_stats64() callback.
10739  */
10740 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10741 {
10742         netdev_stats_to_stats64(s, &dev->stats);
10743         dev_fetch_sw_netstats(s, dev->tstats);
10744 }
10745 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10746
10747 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10748 {
10749         struct netdev_queue *queue = dev_ingress_queue(dev);
10750
10751 #ifdef CONFIG_NET_CLS_ACT
10752         if (queue)
10753                 return queue;
10754         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10755         if (!queue)
10756                 return NULL;
10757         netdev_init_one_queue(dev, queue, NULL);
10758         RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10759         queue->qdisc_sleeping = &noop_qdisc;
10760         rcu_assign_pointer(dev->ingress_queue, queue);
10761 #endif
10762         return queue;
10763 }
10764
10765 static const struct ethtool_ops default_ethtool_ops;
10766
10767 void netdev_set_default_ethtool_ops(struct net_device *dev,
10768                                     const struct ethtool_ops *ops)
10769 {
10770         if (dev->ethtool_ops == &default_ethtool_ops)
10771                 dev->ethtool_ops = ops;
10772 }
10773 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10774
10775 void netdev_freemem(struct net_device *dev)
10776 {
10777         char *addr = (char *)dev - dev->padded;
10778
10779         kvfree(addr);
10780 }
10781
10782 /**
10783  * alloc_netdev_mqs - allocate network device
10784  * @sizeof_priv: size of private data to allocate space for
10785  * @name: device name format string
10786  * @name_assign_type: origin of device name
10787  * @setup: callback to initialize device
10788  * @txqs: the number of TX subqueues to allocate
10789  * @rxqs: the number of RX subqueues to allocate
10790  *
10791  * Allocates a struct net_device with private data area for driver use
10792  * and performs basic initialization.  Also allocates subqueue structs
10793  * for each queue on the device.
10794  */
10795 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10796                 unsigned char name_assign_type,
10797                 void (*setup)(struct net_device *),
10798                 unsigned int txqs, unsigned int rxqs)
10799 {
10800         struct net_device *dev;
10801         unsigned int alloc_size;
10802         struct net_device *p;
10803
10804         BUG_ON(strlen(name) >= sizeof(dev->name));
10805
10806         if (txqs < 1) {
10807                 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10808                 return NULL;
10809         }
10810
10811         if (rxqs < 1) {
10812                 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10813                 return NULL;
10814         }
10815
10816         alloc_size = sizeof(struct net_device);
10817         if (sizeof_priv) {
10818                 /* ensure 32-byte alignment of private area */
10819                 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10820                 alloc_size += sizeof_priv;
10821         }
10822         /* ensure 32-byte alignment of whole construct */
10823         alloc_size += NETDEV_ALIGN - 1;
10824
10825         p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10826         if (!p)
10827                 return NULL;
10828
10829         dev = PTR_ALIGN(p, NETDEV_ALIGN);
10830         dev->padded = (char *)dev - (char *)p;
10831
10832 #ifdef CONFIG_PCPU_DEV_REFCNT
10833         dev->pcpu_refcnt = alloc_percpu(int);
10834         if (!dev->pcpu_refcnt)
10835                 goto free_dev;
10836         dev_hold(dev);
10837 #else
10838         refcount_set(&dev->dev_refcnt, 1);
10839 #endif
10840
10841         if (dev_addr_init(dev))
10842                 goto free_pcpu;
10843
10844         dev_mc_init(dev);
10845         dev_uc_init(dev);
10846
10847         dev_net_set(dev, &init_net);
10848
10849         dev->gso_max_size = GSO_MAX_SIZE;
10850         dev->gso_max_segs = GSO_MAX_SEGS;
10851         dev->upper_level = 1;
10852         dev->lower_level = 1;
10853 #ifdef CONFIG_LOCKDEP
10854         dev->nested_level = 0;
10855         INIT_LIST_HEAD(&dev->unlink_list);
10856 #endif
10857
10858         INIT_LIST_HEAD(&dev->napi_list);
10859         INIT_LIST_HEAD(&dev->unreg_list);
10860         INIT_LIST_HEAD(&dev->close_list);
10861         INIT_LIST_HEAD(&dev->link_watch_list);
10862         INIT_LIST_HEAD(&dev->adj_list.upper);
10863         INIT_LIST_HEAD(&dev->adj_list.lower);
10864         INIT_LIST_HEAD(&dev->ptype_all);
10865         INIT_LIST_HEAD(&dev->ptype_specific);
10866         INIT_LIST_HEAD(&dev->net_notifier_list);
10867 #ifdef CONFIG_NET_SCHED
10868         hash_init(dev->qdisc_hash);
10869 #endif
10870         dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10871         setup(dev);
10872
10873         if (!dev->tx_queue_len) {
10874                 dev->priv_flags |= IFF_NO_QUEUE;
10875                 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10876         }
10877
10878         dev->num_tx_queues = txqs;
10879         dev->real_num_tx_queues = txqs;
10880         if (netif_alloc_netdev_queues(dev))
10881                 goto free_all;
10882
10883         dev->num_rx_queues = rxqs;
10884         dev->real_num_rx_queues = rxqs;
10885         if (netif_alloc_rx_queues(dev))
10886                 goto free_all;
10887
10888         strcpy(dev->name, name);
10889         dev->name_assign_type = name_assign_type;
10890         dev->group = INIT_NETDEV_GROUP;
10891         if (!dev->ethtool_ops)
10892                 dev->ethtool_ops = &default_ethtool_ops;
10893
10894         nf_hook_netdev_init(dev);
10895
10896         return dev;
10897
10898 free_all:
10899         free_netdev(dev);
10900         return NULL;
10901
10902 free_pcpu:
10903 #ifdef CONFIG_PCPU_DEV_REFCNT
10904         free_percpu(dev->pcpu_refcnt);
10905 free_dev:
10906 #endif
10907         netdev_freemem(dev);
10908         return NULL;
10909 }
10910 EXPORT_SYMBOL(alloc_netdev_mqs);
10911
10912 /**
10913  * free_netdev - free network device
10914  * @dev: device
10915  *
10916  * This function does the last stage of destroying an allocated device
10917  * interface. The reference to the device object is released. If this
10918  * is the last reference then it will be freed.Must be called in process
10919  * context.
10920  */
10921 void free_netdev(struct net_device *dev)
10922 {
10923         struct napi_struct *p, *n;
10924
10925         might_sleep();
10926
10927         /* When called immediately after register_netdevice() failed the unwind
10928          * handling may still be dismantling the device. Handle that case by
10929          * deferring the free.
10930          */
10931         if (dev->reg_state == NETREG_UNREGISTERING) {
10932                 ASSERT_RTNL();
10933                 dev->needs_free_netdev = true;
10934                 return;
10935         }
10936
10937         netif_free_tx_queues(dev);
10938         netif_free_rx_queues(dev);
10939
10940         kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10941
10942         /* Flush device addresses */
10943         dev_addr_flush(dev);
10944
10945         list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10946                 netif_napi_del(p);
10947
10948 #ifdef CONFIG_PCPU_DEV_REFCNT
10949         free_percpu(dev->pcpu_refcnt);
10950         dev->pcpu_refcnt = NULL;
10951 #endif
10952         free_percpu(dev->xdp_bulkq);
10953         dev->xdp_bulkq = NULL;
10954
10955         /*  Compatibility with error handling in drivers */
10956         if (dev->reg_state == NETREG_UNINITIALIZED) {
10957                 netdev_freemem(dev);
10958                 return;
10959         }
10960
10961         BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10962         dev->reg_state = NETREG_RELEASED;
10963
10964         /* will free via device release */
10965         put_device(&dev->dev);
10966 }
10967 EXPORT_SYMBOL(free_netdev);
10968
10969 /**
10970  *      synchronize_net -  Synchronize with packet receive processing
10971  *
10972  *      Wait for packets currently being received to be done.
10973  *      Does not block later packets from starting.
10974  */
10975 void synchronize_net(void)
10976 {
10977         might_sleep();
10978         if (rtnl_is_locked())
10979                 synchronize_rcu_expedited();
10980         else
10981                 synchronize_rcu();
10982 }
10983 EXPORT_SYMBOL(synchronize_net);
10984
10985 /**
10986  *      unregister_netdevice_queue - remove device from the kernel
10987  *      @dev: device
10988  *      @head: list
10989  *
10990  *      This function shuts down a device interface and removes it
10991  *      from the kernel tables.
10992  *      If head not NULL, device is queued to be unregistered later.
10993  *
10994  *      Callers must hold the rtnl semaphore.  You may want
10995  *      unregister_netdev() instead of this.
10996  */
10997
10998 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10999 {
11000         ASSERT_RTNL();
11001
11002         if (head) {
11003                 list_move_tail(&dev->unreg_list, head);
11004         } else {
11005                 LIST_HEAD(single);
11006
11007                 list_add(&dev->unreg_list, &single);
11008                 unregister_netdevice_many(&single);
11009         }
11010 }
11011 EXPORT_SYMBOL(unregister_netdevice_queue);
11012
11013 /**
11014  *      unregister_netdevice_many - unregister many devices
11015  *      @head: list of devices
11016  *
11017  *  Note: As most callers use a stack allocated list_head,
11018  *  we force a list_del() to make sure stack wont be corrupted later.
11019  */
11020 void unregister_netdevice_many(struct list_head *head)
11021 {
11022         struct net_device *dev, *tmp;
11023         LIST_HEAD(close_head);
11024
11025         BUG_ON(dev_boot_phase);
11026         ASSERT_RTNL();
11027
11028         if (list_empty(head))
11029                 return;
11030
11031         list_for_each_entry_safe(dev, tmp, head, unreg_list) {
11032                 /* Some devices call without registering
11033                  * for initialization unwind. Remove those
11034                  * devices and proceed with the remaining.
11035                  */
11036                 if (dev->reg_state == NETREG_UNINITIALIZED) {
11037                         pr_debug("unregister_netdevice: device %s/%p never was registered\n",
11038                                  dev->name, dev);
11039
11040                         WARN_ON(1);
11041                         list_del(&dev->unreg_list);
11042                         continue;
11043                 }
11044                 dev->dismantle = true;
11045                 BUG_ON(dev->reg_state != NETREG_REGISTERED);
11046         }
11047
11048         /* If device is running, close it first. */
11049         list_for_each_entry(dev, head, unreg_list)
11050                 list_add_tail(&dev->close_list, &close_head);
11051         dev_close_many(&close_head, true);
11052
11053         list_for_each_entry(dev, head, unreg_list) {
11054                 /* And unlink it from device chain. */
11055                 unlist_netdevice(dev);
11056
11057                 dev->reg_state = NETREG_UNREGISTERING;
11058         }
11059         flush_all_backlogs();
11060
11061         synchronize_net();
11062
11063         list_for_each_entry(dev, head, unreg_list) {
11064                 struct sk_buff *skb = NULL;
11065
11066                 /* Shutdown queueing discipline. */
11067                 dev_shutdown(dev);
11068
11069                 dev_xdp_uninstall(dev);
11070
11071                 /* Notify protocols, that we are about to destroy
11072                  * this device. They should clean all the things.
11073                  */
11074                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11075
11076                 if (!dev->rtnl_link_ops ||
11077                     dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
11078                         skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
11079                                                      GFP_KERNEL, NULL, 0);
11080
11081                 /*
11082                  *      Flush the unicast and multicast chains
11083                  */
11084                 dev_uc_flush(dev);
11085                 dev_mc_flush(dev);
11086
11087                 netdev_name_node_alt_flush(dev);
11088                 netdev_name_node_free(dev->name_node);
11089
11090                 if (dev->netdev_ops->ndo_uninit)
11091                         dev->netdev_ops->ndo_uninit(dev);
11092
11093                 if (skb)
11094                         rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
11095
11096                 /* Notifier chain MUST detach us all upper devices. */
11097                 WARN_ON(netdev_has_any_upper_dev(dev));
11098                 WARN_ON(netdev_has_any_lower_dev(dev));
11099
11100                 /* Remove entries from kobject tree */
11101                 netdev_unregister_kobject(dev);
11102 #ifdef CONFIG_XPS
11103                 /* Remove XPS queueing entries */
11104                 netif_reset_xps_queues_gt(dev, 0);
11105 #endif
11106         }
11107
11108         synchronize_net();
11109
11110         list_for_each_entry(dev, head, unreg_list) {
11111                 dev_put(dev);
11112                 net_set_todo(dev);
11113         }
11114
11115         list_del(head);
11116 }
11117 EXPORT_SYMBOL(unregister_netdevice_many);
11118
11119 /**
11120  *      unregister_netdev - remove device from the kernel
11121  *      @dev: device
11122  *
11123  *      This function shuts down a device interface and removes it
11124  *      from the kernel tables.
11125  *
11126  *      This is just a wrapper for unregister_netdevice that takes
11127  *      the rtnl semaphore.  In general you want to use this and not
11128  *      unregister_netdevice.
11129  */
11130 void unregister_netdev(struct net_device *dev)
11131 {
11132         rtnl_lock();
11133         unregister_netdevice(dev);
11134         rtnl_unlock();
11135 }
11136 EXPORT_SYMBOL(unregister_netdev);
11137
11138 /**
11139  *      __dev_change_net_namespace - move device to different nethost namespace
11140  *      @dev: device
11141  *      @net: network namespace
11142  *      @pat: If not NULL name pattern to try if the current device name
11143  *            is already taken in the destination network namespace.
11144  *      @new_ifindex: If not zero, specifies device index in the target
11145  *                    namespace.
11146  *
11147  *      This function shuts down a device interface and moves it
11148  *      to a new network namespace. On success 0 is returned, on
11149  *      a failure a netagive errno code is returned.
11150  *
11151  *      Callers must hold the rtnl semaphore.
11152  */
11153
11154 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
11155                                const char *pat, int new_ifindex)
11156 {
11157         struct net *net_old = dev_net(dev);
11158         int err, new_nsid;
11159
11160         ASSERT_RTNL();
11161
11162         /* Don't allow namespace local devices to be moved. */
11163         err = -EINVAL;
11164         if (dev->features & NETIF_F_NETNS_LOCAL)
11165                 goto out;
11166
11167         /* Ensure the device has been registrered */
11168         if (dev->reg_state != NETREG_REGISTERED)
11169                 goto out;
11170
11171         /* Get out if there is nothing todo */
11172         err = 0;
11173         if (net_eq(net_old, net))
11174                 goto out;
11175
11176         /* Pick the destination device name, and ensure
11177          * we can use it in the destination network namespace.
11178          */
11179         err = -EEXIST;
11180         if (netdev_name_in_use(net, dev->name)) {
11181                 /* We get here if we can't use the current device name */
11182                 if (!pat)
11183                         goto out;
11184                 err = dev_get_valid_name(net, dev, pat);
11185                 if (err < 0)
11186                         goto out;
11187         }
11188
11189         /* Check that new_ifindex isn't used yet. */
11190         err = -EBUSY;
11191         if (new_ifindex && __dev_get_by_index(net, new_ifindex))
11192                 goto out;
11193
11194         /*
11195          * And now a mini version of register_netdevice unregister_netdevice.
11196          */
11197
11198         /* If device is running close it first. */
11199         dev_close(dev);
11200
11201         /* And unlink it from device chain */
11202         unlist_netdevice(dev);
11203
11204         synchronize_net();
11205
11206         /* Shutdown queueing discipline. */
11207         dev_shutdown(dev);
11208
11209         /* Notify protocols, that we are about to destroy
11210          * this device. They should clean all the things.
11211          *
11212          * Note that dev->reg_state stays at NETREG_REGISTERED.
11213          * This is wanted because this way 8021q and macvlan know
11214          * the device is just moving and can keep their slaves up.
11215          */
11216         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11217         rcu_barrier();
11218
11219         new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11220         /* If there is an ifindex conflict assign a new one */
11221         if (!new_ifindex) {
11222                 if (__dev_get_by_index(net, dev->ifindex))
11223                         new_ifindex = dev_new_index(net);
11224                 else
11225                         new_ifindex = dev->ifindex;
11226         }
11227
11228         rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11229                             new_ifindex);
11230
11231         /*
11232          *      Flush the unicast and multicast chains
11233          */
11234         dev_uc_flush(dev);
11235         dev_mc_flush(dev);
11236
11237         /* Send a netdev-removed uevent to the old namespace */
11238         kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11239         netdev_adjacent_del_links(dev);
11240
11241         /* Move per-net netdevice notifiers that are following the netdevice */
11242         move_netdevice_notifiers_dev_net(dev, net);
11243
11244         /* Actually switch the network namespace */
11245         dev_net_set(dev, net);
11246         dev->ifindex = new_ifindex;
11247
11248         /* Send a netdev-add uevent to the new namespace */
11249         kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11250         netdev_adjacent_add_links(dev);
11251
11252         /* Fixup kobjects */
11253         err = device_rename(&dev->dev, dev->name);
11254         WARN_ON(err);
11255
11256         /* Adapt owner in case owning user namespace of target network
11257          * namespace is different from the original one.
11258          */
11259         err = netdev_change_owner(dev, net_old, net);
11260         WARN_ON(err);
11261
11262         /* Add the device back in the hashes */
11263         list_netdevice(dev);
11264
11265         /* Notify protocols, that a new device appeared. */
11266         call_netdevice_notifiers(NETDEV_REGISTER, dev);
11267
11268         /*
11269          *      Prevent userspace races by waiting until the network
11270          *      device is fully setup before sending notifications.
11271          */
11272         rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
11273
11274         synchronize_net();
11275         err = 0;
11276 out:
11277         return err;
11278 }
11279 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11280
11281 static int dev_cpu_dead(unsigned int oldcpu)
11282 {
11283         struct sk_buff **list_skb;
11284         struct sk_buff *skb;
11285         unsigned int cpu;
11286         struct softnet_data *sd, *oldsd, *remsd = NULL;
11287
11288         local_irq_disable();
11289         cpu = smp_processor_id();
11290         sd = &per_cpu(softnet_data, cpu);
11291         oldsd = &per_cpu(softnet_data, oldcpu);
11292
11293         /* Find end of our completion_queue. */
11294         list_skb = &sd->completion_queue;
11295         while (*list_skb)
11296                 list_skb = &(*list_skb)->next;
11297         /* Append completion queue from offline CPU. */
11298         *list_skb = oldsd->completion_queue;
11299         oldsd->completion_queue = NULL;
11300
11301         /* Append output queue from offline CPU. */
11302         if (oldsd->output_queue) {
11303                 *sd->output_queue_tailp = oldsd->output_queue;
11304                 sd->output_queue_tailp = oldsd->output_queue_tailp;
11305                 oldsd->output_queue = NULL;
11306                 oldsd->output_queue_tailp = &oldsd->output_queue;
11307         }
11308         /* Append NAPI poll list from offline CPU, with one exception :
11309          * process_backlog() must be called by cpu owning percpu backlog.
11310          * We properly handle process_queue & input_pkt_queue later.
11311          */
11312         while (!list_empty(&oldsd->poll_list)) {
11313                 struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11314                                                             struct napi_struct,
11315                                                             poll_list);
11316
11317                 list_del_init(&napi->poll_list);
11318                 if (napi->poll == process_backlog)
11319                         napi->state = 0;
11320                 else
11321                         ____napi_schedule(sd, napi);
11322         }
11323
11324         raise_softirq_irqoff(NET_TX_SOFTIRQ);
11325         local_irq_enable();
11326
11327 #ifdef CONFIG_RPS
11328         remsd = oldsd->rps_ipi_list;
11329         oldsd->rps_ipi_list = NULL;
11330 #endif
11331         /* send out pending IPI's on offline CPU */
11332         net_rps_send_ipi(remsd);
11333
11334         /* Process offline CPU's input_pkt_queue */
11335         while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11336                 netif_rx_ni(skb);
11337                 input_queue_head_incr(oldsd);
11338         }
11339         while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11340                 netif_rx_ni(skb);
11341                 input_queue_head_incr(oldsd);
11342         }
11343
11344         return 0;
11345 }
11346
11347 /**
11348  *      netdev_increment_features - increment feature set by one
11349  *      @all: current feature set
11350  *      @one: new feature set
11351  *      @mask: mask feature set
11352  *
11353  *      Computes a new feature set after adding a device with feature set
11354  *      @one to the master device with current feature set @all.  Will not
11355  *      enable anything that is off in @mask. Returns the new feature set.
11356  */
11357 netdev_features_t netdev_increment_features(netdev_features_t all,
11358         netdev_features_t one, netdev_features_t mask)
11359 {
11360         if (mask & NETIF_F_HW_CSUM)
11361                 mask |= NETIF_F_CSUM_MASK;
11362         mask |= NETIF_F_VLAN_CHALLENGED;
11363
11364         all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11365         all &= one | ~NETIF_F_ALL_FOR_ALL;
11366
11367         /* If one device supports hw checksumming, set for all. */
11368         if (all & NETIF_F_HW_CSUM)
11369                 all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11370
11371         return all;
11372 }
11373 EXPORT_SYMBOL(netdev_increment_features);
11374
11375 static struct hlist_head * __net_init netdev_create_hash(void)
11376 {
11377         int i;
11378         struct hlist_head *hash;
11379
11380         hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11381         if (hash != NULL)
11382                 for (i = 0; i < NETDEV_HASHENTRIES; i++)
11383                         INIT_HLIST_HEAD(&hash[i]);
11384
11385         return hash;
11386 }
11387
11388 /* Initialize per network namespace state */
11389 static int __net_init netdev_init(struct net *net)
11390 {
11391         BUILD_BUG_ON(GRO_HASH_BUCKETS >
11392                      8 * sizeof_field(struct napi_struct, gro_bitmask));
11393
11394         if (net != &init_net)
11395                 INIT_LIST_HEAD(&net->dev_base_head);
11396
11397         net->dev_name_head = netdev_create_hash();
11398         if (net->dev_name_head == NULL)
11399                 goto err_name;
11400
11401         net->dev_index_head = netdev_create_hash();
11402         if (net->dev_index_head == NULL)
11403                 goto err_idx;
11404
11405         RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11406
11407         return 0;
11408
11409 err_idx:
11410         kfree(net->dev_name_head);
11411 err_name:
11412         return -ENOMEM;
11413 }
11414
11415 /**
11416  *      netdev_drivername - network driver for the device
11417  *      @dev: network device
11418  *
11419  *      Determine network driver for device.
11420  */
11421 const char *netdev_drivername(const struct net_device *dev)
11422 {
11423         const struct device_driver *driver;
11424         const struct device *parent;
11425         const char *empty = "";
11426
11427         parent = dev->dev.parent;
11428         if (!parent)
11429                 return empty;
11430
11431         driver = parent->driver;
11432         if (driver && driver->name)
11433                 return driver->name;
11434         return empty;
11435 }
11436
11437 static void __netdev_printk(const char *level, const struct net_device *dev,
11438                             struct va_format *vaf)
11439 {
11440         if (dev && dev->dev.parent) {
11441                 dev_printk_emit(level[1] - '0',
11442                                 dev->dev.parent,
11443                                 "%s %s %s%s: %pV",
11444                                 dev_driver_string(dev->dev.parent),
11445                                 dev_name(dev->dev.parent),
11446                                 netdev_name(dev), netdev_reg_state(dev),
11447                                 vaf);
11448         } else if (dev) {
11449                 printk("%s%s%s: %pV",
11450                        level, netdev_name(dev), netdev_reg_state(dev), vaf);
11451         } else {
11452                 printk("%s(NULL net_device): %pV", level, vaf);
11453         }
11454 }
11455
11456 void netdev_printk(const char *level, const struct net_device *dev,
11457                    const char *format, ...)
11458 {
11459         struct va_format vaf;
11460         va_list args;
11461
11462         va_start(args, format);
11463
11464         vaf.fmt = format;
11465         vaf.va = &args;
11466
11467         __netdev_printk(level, dev, &vaf);
11468
11469         va_end(args);
11470 }
11471 EXPORT_SYMBOL(netdev_printk);
11472
11473 #define define_netdev_printk_level(func, level)                 \
11474 void func(const struct net_device *dev, const char *fmt, ...)   \
11475 {                                                               \
11476         struct va_format vaf;                                   \
11477         va_list args;                                           \
11478                                                                 \
11479         va_start(args, fmt);                                    \
11480                                                                 \
11481         vaf.fmt = fmt;                                          \
11482         vaf.va = &args;                                         \
11483                                                                 \
11484         __netdev_printk(level, dev, &vaf);                      \
11485                                                                 \
11486         va_end(args);                                           \
11487 }                                                               \
11488 EXPORT_SYMBOL(func);
11489
11490 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11491 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11492 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11493 define_netdev_printk_level(netdev_err, KERN_ERR);
11494 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11495 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11496 define_netdev_printk_level(netdev_info, KERN_INFO);
11497
11498 static void __net_exit netdev_exit(struct net *net)
11499 {
11500         kfree(net->dev_name_head);
11501         kfree(net->dev_index_head);
11502         if (net != &init_net)
11503                 WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11504 }
11505
11506 static struct pernet_operations __net_initdata netdev_net_ops = {
11507         .init = netdev_init,
11508         .exit = netdev_exit,
11509 };
11510
11511 static void __net_exit default_device_exit(struct net *net)
11512 {
11513         struct net_device *dev, *aux;
11514         /*
11515          * Push all migratable network devices back to the
11516          * initial network namespace
11517          */
11518         rtnl_lock();
11519         for_each_netdev_safe(net, dev, aux) {
11520                 int err;
11521                 char fb_name[IFNAMSIZ];
11522
11523                 /* Ignore unmoveable devices (i.e. loopback) */
11524                 if (dev->features & NETIF_F_NETNS_LOCAL)
11525                         continue;
11526
11527                 /* Leave virtual devices for the generic cleanup */
11528                 if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11529                         continue;
11530
11531                 /* Push remaining network devices to init_net */
11532                 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11533                 if (netdev_name_in_use(&init_net, fb_name))
11534                         snprintf(fb_name, IFNAMSIZ, "dev%%d");
11535                 err = dev_change_net_namespace(dev, &init_net, fb_name);
11536                 if (err) {
11537                         pr_emerg("%s: failed to move %s to init_net: %d\n",
11538                                  __func__, dev->name, err);
11539                         BUG();
11540                 }
11541         }
11542         rtnl_unlock();
11543 }
11544
11545 static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
11546 {
11547         /* Return with the rtnl_lock held when there are no network
11548          * devices unregistering in any network namespace in net_list.
11549          */
11550         struct net *net;
11551         bool unregistering;
11552         DEFINE_WAIT_FUNC(wait, woken_wake_function);
11553
11554         add_wait_queue(&netdev_unregistering_wq, &wait);
11555         for (;;) {
11556                 unregistering = false;
11557                 rtnl_lock();
11558                 list_for_each_entry(net, net_list, exit_list) {
11559                         if (net->dev_unreg_count > 0) {
11560                                 unregistering = true;
11561                                 break;
11562                         }
11563                 }
11564                 if (!unregistering)
11565                         break;
11566                 __rtnl_unlock();
11567
11568                 wait_woken(&wait, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
11569         }
11570         remove_wait_queue(&netdev_unregistering_wq, &wait);
11571 }
11572
11573 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11574 {
11575         /* At exit all network devices most be removed from a network
11576          * namespace.  Do this in the reverse order of registration.
11577          * Do this across as many network namespaces as possible to
11578          * improve batching efficiency.
11579          */
11580         struct net_device *dev;
11581         struct net *net;
11582         LIST_HEAD(dev_kill_list);
11583
11584         /* To prevent network device cleanup code from dereferencing
11585          * loopback devices or network devices that have been freed
11586          * wait here for all pending unregistrations to complete,
11587          * before unregistring the loopback device and allowing the
11588          * network namespace be freed.
11589          *
11590          * The netdev todo list containing all network devices
11591          * unregistrations that happen in default_device_exit_batch
11592          * will run in the rtnl_unlock() at the end of
11593          * default_device_exit_batch.
11594          */
11595         rtnl_lock_unregistering(net_list);
11596         list_for_each_entry(net, net_list, exit_list) {
11597                 for_each_netdev_reverse(net, dev) {
11598                         if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11599                                 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11600                         else
11601                                 unregister_netdevice_queue(dev, &dev_kill_list);
11602                 }
11603         }
11604         unregister_netdevice_many(&dev_kill_list);
11605         rtnl_unlock();
11606 }
11607
11608 static struct pernet_operations __net_initdata default_device_ops = {
11609         .exit = default_device_exit,
11610         .exit_batch = default_device_exit_batch,
11611 };
11612
11613 /*
11614  *      Initialize the DEV module. At boot time this walks the device list and
11615  *      unhooks any devices that fail to initialise (normally hardware not
11616  *      present) and leaves us with a valid list of present and active devices.
11617  *
11618  */
11619
11620 /*
11621  *       This is called single threaded during boot, so no need
11622  *       to take the rtnl semaphore.
11623  */
11624 static int __init net_dev_init(void)
11625 {
11626         int i, rc = -ENOMEM;
11627
11628         BUG_ON(!dev_boot_phase);
11629
11630         if (dev_proc_init())
11631                 goto out;
11632
11633         if (netdev_kobject_init())
11634                 goto out;
11635
11636         INIT_LIST_HEAD(&ptype_all);
11637         for (i = 0; i < PTYPE_HASH_SIZE; i++)
11638                 INIT_LIST_HEAD(&ptype_base[i]);
11639
11640         INIT_LIST_HEAD(&offload_base);
11641
11642         if (register_pernet_subsys(&netdev_net_ops))
11643                 goto out;
11644
11645         /*
11646          *      Initialise the packet receive queues.
11647          */
11648
11649         for_each_possible_cpu(i) {
11650                 struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11651                 struct softnet_data *sd = &per_cpu(softnet_data, i);
11652
11653                 INIT_WORK(flush, flush_backlog);
11654
11655                 skb_queue_head_init(&sd->input_pkt_queue);
11656                 skb_queue_head_init(&sd->process_queue);
11657 #ifdef CONFIG_XFRM_OFFLOAD
11658                 skb_queue_head_init(&sd->xfrm_backlog);
11659 #endif
11660                 INIT_LIST_HEAD(&sd->poll_list);
11661                 sd->output_queue_tailp = &sd->output_queue;
11662 #ifdef CONFIG_RPS
11663                 INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11664                 sd->cpu = i;
11665 #endif
11666
11667                 init_gro_hash(&sd->backlog);
11668                 sd->backlog.poll = process_backlog;
11669                 sd->backlog.weight = weight_p;
11670         }
11671
11672         dev_boot_phase = 0;
11673
11674         /* The loopback device is special if any other network devices
11675          * is present in a network namespace the loopback device must
11676          * be present. Since we now dynamically allocate and free the
11677          * loopback device ensure this invariant is maintained by
11678          * keeping the loopback device as the first device on the
11679          * list of network devices.  Ensuring the loopback devices
11680          * is the first device that appears and the last network device
11681          * that disappears.
11682          */
11683         if (register_pernet_device(&loopback_net_ops))
11684                 goto out;
11685
11686         if (register_pernet_device(&default_device_ops))
11687                 goto out;
11688
11689         open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11690         open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11691
11692         rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11693                                        NULL, dev_cpu_dead);
11694         WARN_ON(rc < 0);
11695         rc = 0;
11696 out:
11697         return rc;
11698 }
11699
11700 subsys_initcall(net_dev_init);