2 * NET3 Protocol independent device support routines.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Derived from the non IP parts of dev.c 1.0.19
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Mark Evans, <evansmp@uhura.aston.ac.uk>
15 * Florian la Roche <rzsfl@rz.uni-sb.de>
16 * Alan Cox <gw4pts@gw4pts.ampr.org>
17 * David Hinds <dahinds@users.sourceforge.net>
18 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
19 * Adam Sulmicki <adam@cfar.umd.edu>
20 * Pekka Riikonen <priikone@poesidon.pspt.fi>
23 * D.J. Barrow : Fixed bug where dev->refcnt gets set
24 * to 2 if register_netdev gets called
25 * before net_dev_init & also removed a
26 * few lines of code in the process.
27 * Alan Cox : device private ioctl copies fields back.
28 * Alan Cox : Transmit queue code does relevant
29 * stunts to keep the queue safe.
30 * Alan Cox : Fixed double lock.
31 * Alan Cox : Fixed promisc NULL pointer trap
32 * ???????? : Support the full private ioctl range
33 * Alan Cox : Moved ioctl permission check into
35 * Tim Kordas : SIOCADDMULTI/SIOCDELMULTI
36 * Alan Cox : 100 backlog just doesn't cut it when
37 * you start doing multicast video 8)
38 * Alan Cox : Rewrote net_bh and list manager.
39 * Alan Cox : Fix ETH_P_ALL echoback lengths.
40 * Alan Cox : Took out transmit every packet pass
41 * Saved a few bytes in the ioctl handler
42 * Alan Cox : Network driver sets packet type before
43 * calling netif_rx. Saves a function
45 * Alan Cox : Hashed net_bh()
46 * Richard Kooijman: Timestamp fixes.
47 * Alan Cox : Wrong field in SIOCGIFDSTADDR
48 * Alan Cox : Device lock protection.
49 * Alan Cox : Fixed nasty side effect of device close
51 * Rudi Cilibrasi : Pass the right thing to
53 * Dave Miller : 32bit quantity for the device lock to
54 * make it work out on a Sparc.
55 * Bjorn Ekwall : Added KERNELD hack.
56 * Alan Cox : Cleaned up the backlog initialise.
57 * Craig Metz : SIOCGIFCONF fix if space for under
59 * Thomas Bogendoerfer : Return ENODEV for dev_open, if there
60 * is no device open function.
61 * Andi Kleen : Fix error reporting for SIOCGIFCONF
62 * Michael Chastain : Fix signed/unsigned for SIOCGIFCONF
63 * Cyrus Durgin : Cleaned for KMOD
64 * Adam Sulmicki : Bug Fix : Network Device Unload
65 * A network device unload needs to purge
67 * Paul Rusty Russell : SIOCSIFNAME
68 * Pekka Riikonen : Netdev boot-time settings code
69 * Andrew Morton : Make unregister_netdevice wait
70 * indefinitely on dev->refcnt
71 * J Hadi Salim : - Backlog queue sampling
72 * - netif_rx() feedback
75 #include <asm/uaccess.h>
76 #include <linux/bitops.h>
77 #include <linux/capability.h>
78 #include <linux/cpu.h>
79 #include <linux/types.h>
80 #include <linux/kernel.h>
81 #include <linux/hash.h>
82 #include <linux/slab.h>
83 #include <linux/sched.h>
84 #include <linux/mutex.h>
85 #include <linux/string.h>
87 #include <linux/socket.h>
88 #include <linux/sockios.h>
89 #include <linux/errno.h>
90 #include <linux/interrupt.h>
91 #include <linux/if_ether.h>
92 #include <linux/netdevice.h>
93 #include <linux/etherdevice.h>
94 #include <linux/ethtool.h>
95 #include <linux/notifier.h>
96 #include <linux/skbuff.h>
97 #include <net/net_namespace.h>
99 #include <linux/rtnetlink.h>
100 #include <linux/stat.h>
102 #include <net/pkt_sched.h>
103 #include <net/checksum.h>
104 #include <net/xfrm.h>
105 #include <linux/highmem.h>
106 #include <linux/init.h>
107 #include <linux/module.h>
108 #include <linux/netpoll.h>
109 #include <linux/rcupdate.h>
110 #include <linux/delay.h>
111 #include <net/iw_handler.h>
112 #include <asm/current.h>
113 #include <linux/audit.h>
114 #include <linux/dmaengine.h>
115 #include <linux/err.h>
116 #include <linux/ctype.h>
117 #include <linux/if_arp.h>
118 #include <linux/if_vlan.h>
119 #include <linux/ip.h>
121 #include <linux/ipv6.h>
122 #include <linux/in.h>
123 #include <linux/jhash.h>
124 #include <linux/random.h>
125 #include <trace/events/napi.h>
126 #include <trace/events/net.h>
127 #include <trace/events/skb.h>
128 #include <linux/pci.h>
129 #include <linux/inetdevice.h>
130 #include <linux/cpu_rmap.h>
131 #include <linux/static_key.h>
133 #include "net-sysfs.h"
135 /* Instead of increasing this, you should create a hash table. */
136 #define MAX_GRO_SKBS 8
138 /* This should be increased if a protocol with a bigger head is added. */
139 #define GRO_MAX_HEAD (MAX_HEADER + 128)
141 static DEFINE_SPINLOCK(ptype_lock);
142 static DEFINE_SPINLOCK(offload_lock);
143 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
144 struct list_head ptype_all __read_mostly; /* Taps */
145 static struct list_head offload_base __read_mostly;
148 * The @dev_base_head list is protected by @dev_base_lock and the rtnl
151 * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
153 * Writers must hold the rtnl semaphore while they loop through the
154 * dev_base_head list, and hold dev_base_lock for writing when they do the
155 * actual updates. This allows pure readers to access the list even
156 * while a writer is preparing to update it.
158 * To put it another way, dev_base_lock is held for writing only to
159 * protect against pure readers; the rtnl semaphore provides the
160 * protection against other writers.
162 * See, for example usages, register_netdevice() and
163 * unregister_netdevice(), which must be called with the rtnl
166 DEFINE_RWLOCK(dev_base_lock);
167 EXPORT_SYMBOL(dev_base_lock);
169 seqcount_t devnet_rename_seq;
171 static inline void dev_base_seq_inc(struct net *net)
173 while (++net->dev_base_seq == 0);
176 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
178 unsigned int hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
180 return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
183 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
185 return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
188 static inline void rps_lock(struct softnet_data *sd)
191 spin_lock(&sd->input_pkt_queue.lock);
195 static inline void rps_unlock(struct softnet_data *sd)
198 spin_unlock(&sd->input_pkt_queue.lock);
202 /* Device list insertion */
203 static int list_netdevice(struct net_device *dev)
205 struct net *net = dev_net(dev);
209 write_lock_bh(&dev_base_lock);
210 list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
211 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
212 hlist_add_head_rcu(&dev->index_hlist,
213 dev_index_hash(net, dev->ifindex));
214 write_unlock_bh(&dev_base_lock);
216 dev_base_seq_inc(net);
221 /* Device list removal
222 * caller must respect a RCU grace period before freeing/reusing dev
224 static void unlist_netdevice(struct net_device *dev)
228 /* Unlink dev from the device chain */
229 write_lock_bh(&dev_base_lock);
230 list_del_rcu(&dev->dev_list);
231 hlist_del_rcu(&dev->name_hlist);
232 hlist_del_rcu(&dev->index_hlist);
233 write_unlock_bh(&dev_base_lock);
235 dev_base_seq_inc(dev_net(dev));
242 static RAW_NOTIFIER_HEAD(netdev_chain);
245 * Device drivers call our routines to queue packets here. We empty the
246 * queue in the local softnet handler.
249 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
250 EXPORT_PER_CPU_SYMBOL(softnet_data);
252 #ifdef CONFIG_LOCKDEP
254 * register_netdevice() inits txq->_xmit_lock and sets lockdep class
255 * according to dev->type
257 static const unsigned short netdev_lock_type[] =
258 {ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
259 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
260 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
261 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
262 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
263 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
264 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
265 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
266 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
267 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
268 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
269 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
270 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
271 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
272 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
274 static const char *const netdev_lock_name[] =
275 {"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
276 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
277 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
278 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
279 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
280 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
281 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
282 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
283 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
284 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
285 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
286 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
287 "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
288 "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
289 "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
291 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
292 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
294 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
298 for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
299 if (netdev_lock_type[i] == dev_type)
301 /* the last key is used by default */
302 return ARRAY_SIZE(netdev_lock_type) - 1;
305 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
306 unsigned short dev_type)
310 i = netdev_lock_pos(dev_type);
311 lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
312 netdev_lock_name[i]);
315 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
319 i = netdev_lock_pos(dev->type);
320 lockdep_set_class_and_name(&dev->addr_list_lock,
321 &netdev_addr_lock_key[i],
322 netdev_lock_name[i]);
325 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
326 unsigned short dev_type)
329 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
334 /*******************************************************************************
336 Protocol management and registration routines
338 *******************************************************************************/
341 * Add a protocol ID to the list. Now that the input handler is
342 * smarter we can dispense with all the messy stuff that used to be
345 * BEWARE!!! Protocol handlers, mangling input packets,
346 * MUST BE last in hash buckets and checking protocol handlers
347 * MUST start from promiscuous ptype_all chain in net_bh.
348 * It is true now, do not change it.
349 * Explanation follows: if protocol handler, mangling packet, will
350 * be the first on list, it is not able to sense, that packet
351 * is cloned and should be copied-on-write, so that it will
352 * change it and subsequent readers will get broken packet.
356 static inline struct list_head *ptype_head(const struct packet_type *pt)
358 if (pt->type == htons(ETH_P_ALL))
361 return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
365 * dev_add_pack - add packet handler
366 * @pt: packet type declaration
368 * Add a protocol handler to the networking stack. The passed &packet_type
369 * is linked into kernel lists and may not be freed until it has been
370 * removed from the kernel lists.
372 * This call does not sleep therefore it can not
373 * guarantee all CPU's that are in middle of receiving packets
374 * will see the new packet type (until the next received packet).
377 void dev_add_pack(struct packet_type *pt)
379 struct list_head *head = ptype_head(pt);
381 spin_lock(&ptype_lock);
382 list_add_rcu(&pt->list, head);
383 spin_unlock(&ptype_lock);
385 EXPORT_SYMBOL(dev_add_pack);
388 * __dev_remove_pack - remove packet handler
389 * @pt: packet type declaration
391 * Remove a protocol handler that was previously added to the kernel
392 * protocol handlers by dev_add_pack(). The passed &packet_type is removed
393 * from the kernel lists and can be freed or reused once this function
396 * The packet type might still be in use by receivers
397 * and must not be freed until after all the CPU's have gone
398 * through a quiescent state.
400 void __dev_remove_pack(struct packet_type *pt)
402 struct list_head *head = ptype_head(pt);
403 struct packet_type *pt1;
405 spin_lock(&ptype_lock);
407 list_for_each_entry(pt1, head, list) {
409 list_del_rcu(&pt->list);
414 pr_warn("dev_remove_pack: %p not found\n", pt);
416 spin_unlock(&ptype_lock);
418 EXPORT_SYMBOL(__dev_remove_pack);
421 * dev_remove_pack - remove packet handler
422 * @pt: packet type declaration
424 * Remove a protocol handler that was previously added to the kernel
425 * protocol handlers by dev_add_pack(). The passed &packet_type is removed
426 * from the kernel lists and can be freed or reused once this function
429 * This call sleeps to guarantee that no CPU is looking at the packet
432 void dev_remove_pack(struct packet_type *pt)
434 __dev_remove_pack(pt);
438 EXPORT_SYMBOL(dev_remove_pack);
442 * dev_add_offload - register offload handlers
443 * @po: protocol offload declaration
445 * Add protocol offload handlers to the networking stack. The passed
446 * &proto_offload is linked into kernel lists and may not be freed until
447 * it has been removed from the kernel lists.
449 * This call does not sleep therefore it can not
450 * guarantee all CPU's that are in middle of receiving packets
451 * will see the new offload handlers (until the next received packet).
453 void dev_add_offload(struct packet_offload *po)
455 struct list_head *head = &offload_base;
457 spin_lock(&offload_lock);
458 list_add_rcu(&po->list, head);
459 spin_unlock(&offload_lock);
461 EXPORT_SYMBOL(dev_add_offload);
464 * __dev_remove_offload - remove offload handler
465 * @po: packet offload declaration
467 * Remove a protocol offload handler that was previously added to the
468 * kernel offload handlers by dev_add_offload(). The passed &offload_type
469 * is removed from the kernel lists and can be freed or reused once this
472 * The packet type might still be in use by receivers
473 * and must not be freed until after all the CPU's have gone
474 * through a quiescent state.
476 void __dev_remove_offload(struct packet_offload *po)
478 struct list_head *head = &offload_base;
479 struct packet_offload *po1;
481 spin_lock(&offload_lock);
483 list_for_each_entry(po1, head, list) {
485 list_del_rcu(&po->list);
490 pr_warn("dev_remove_offload: %p not found\n", po);
492 spin_unlock(&offload_lock);
494 EXPORT_SYMBOL(__dev_remove_offload);
497 * dev_remove_offload - remove packet offload handler
498 * @po: packet offload declaration
500 * Remove a packet offload handler that was previously added to the kernel
501 * offload handlers by dev_add_offload(). The passed &offload_type is
502 * removed from the kernel lists and can be freed or reused once this
505 * This call sleeps to guarantee that no CPU is looking at the packet
508 void dev_remove_offload(struct packet_offload *po)
510 __dev_remove_offload(po);
514 EXPORT_SYMBOL(dev_remove_offload);
516 /******************************************************************************
518 Device Boot-time Settings Routines
520 *******************************************************************************/
522 /* Boot time configuration table */
523 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
526 * netdev_boot_setup_add - add new setup entry
527 * @name: name of the device
528 * @map: configured settings for the device
530 * Adds new setup entry to the dev_boot_setup list. The function
531 * returns 0 on error and 1 on success. This is a generic routine to
534 static int netdev_boot_setup_add(char *name, struct ifmap *map)
536 struct netdev_boot_setup *s;
540 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
541 if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
542 memset(s[i].name, 0, sizeof(s[i].name));
543 strlcpy(s[i].name, name, IFNAMSIZ);
544 memcpy(&s[i].map, map, sizeof(s[i].map));
549 return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
553 * netdev_boot_setup_check - check boot time settings
554 * @dev: the netdevice
556 * Check boot time settings for the device.
557 * The found settings are set for the device to be used
558 * later in the device probing.
559 * Returns 0 if no settings found, 1 if they are.
561 int netdev_boot_setup_check(struct net_device *dev)
563 struct netdev_boot_setup *s = dev_boot_setup;
566 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
567 if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
568 !strcmp(dev->name, s[i].name)) {
569 dev->irq = s[i].map.irq;
570 dev->base_addr = s[i].map.base_addr;
571 dev->mem_start = s[i].map.mem_start;
572 dev->mem_end = s[i].map.mem_end;
578 EXPORT_SYMBOL(netdev_boot_setup_check);
582 * netdev_boot_base - get address from boot time settings
583 * @prefix: prefix for network device
584 * @unit: id for network device
586 * Check boot time settings for the base address of device.
587 * The found settings are set for the device to be used
588 * later in the device probing.
589 * Returns 0 if no settings found.
591 unsigned long netdev_boot_base(const char *prefix, int unit)
593 const struct netdev_boot_setup *s = dev_boot_setup;
597 sprintf(name, "%s%d", prefix, unit);
600 * If device already registered then return base of 1
601 * to indicate not to probe for this interface
603 if (__dev_get_by_name(&init_net, name))
606 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
607 if (!strcmp(name, s[i].name))
608 return s[i].map.base_addr;
613 * Saves at boot time configured settings for any netdevice.
615 int __init netdev_boot_setup(char *str)
620 str = get_options(str, ARRAY_SIZE(ints), ints);
625 memset(&map, 0, sizeof(map));
629 map.base_addr = ints[2];
631 map.mem_start = ints[3];
633 map.mem_end = ints[4];
635 /* Add new entry to the list */
636 return netdev_boot_setup_add(str, &map);
639 __setup("netdev=", netdev_boot_setup);
641 /*******************************************************************************
643 Device Interface Subroutines
645 *******************************************************************************/
648 * __dev_get_by_name - find a device by its name
649 * @net: the applicable net namespace
650 * @name: name to find
652 * Find an interface by name. Must be called under RTNL semaphore
653 * or @dev_base_lock. If the name is found a pointer to the device
654 * is returned. If the name is not found then %NULL is returned. The
655 * reference counters are not incremented so the caller must be
656 * careful with locks.
659 struct net_device *__dev_get_by_name(struct net *net, const char *name)
661 struct net_device *dev;
662 struct hlist_head *head = dev_name_hash(net, name);
664 hlist_for_each_entry(dev, head, name_hlist)
665 if (!strncmp(dev->name, name, IFNAMSIZ))
670 EXPORT_SYMBOL(__dev_get_by_name);
673 * dev_get_by_name_rcu - find a device by its name
674 * @net: the applicable net namespace
675 * @name: name to find
677 * Find an interface by name.
678 * If the name is found a pointer to the device is returned.
679 * If the name is not found then %NULL is returned.
680 * The reference counters are not incremented so the caller must be
681 * careful with locks. The caller must hold RCU lock.
684 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
686 struct net_device *dev;
687 struct hlist_head *head = dev_name_hash(net, name);
689 hlist_for_each_entry_rcu(dev, head, name_hlist)
690 if (!strncmp(dev->name, name, IFNAMSIZ))
695 EXPORT_SYMBOL(dev_get_by_name_rcu);
698 * dev_get_by_name - find a device by its name
699 * @net: the applicable net namespace
700 * @name: name to find
702 * Find an interface by name. This can be called from any
703 * context and does its own locking. The returned handle has
704 * the usage count incremented and the caller must use dev_put() to
705 * release it when it is no longer needed. %NULL is returned if no
706 * matching device is found.
709 struct net_device *dev_get_by_name(struct net *net, const char *name)
711 struct net_device *dev;
714 dev = dev_get_by_name_rcu(net, name);
720 EXPORT_SYMBOL(dev_get_by_name);
723 * __dev_get_by_index - find a device by its ifindex
724 * @net: the applicable net namespace
725 * @ifindex: index of device
727 * Search for an interface by index. Returns %NULL if the device
728 * is not found or a pointer to the device. The device has not
729 * had its reference counter increased so the caller must be careful
730 * about locking. The caller must hold either the RTNL semaphore
734 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
736 struct net_device *dev;
737 struct hlist_head *head = dev_index_hash(net, ifindex);
739 hlist_for_each_entry(dev, head, index_hlist)
740 if (dev->ifindex == ifindex)
745 EXPORT_SYMBOL(__dev_get_by_index);
748 * dev_get_by_index_rcu - find a device by its ifindex
749 * @net: the applicable net namespace
750 * @ifindex: index of device
752 * Search for an interface by index. Returns %NULL if the device
753 * is not found or a pointer to the device. The device has not
754 * had its reference counter increased so the caller must be careful
755 * about locking. The caller must hold RCU lock.
758 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
760 struct net_device *dev;
761 struct hlist_head *head = dev_index_hash(net, ifindex);
763 hlist_for_each_entry_rcu(dev, head, index_hlist)
764 if (dev->ifindex == ifindex)
769 EXPORT_SYMBOL(dev_get_by_index_rcu);
773 * dev_get_by_index - find a device by its ifindex
774 * @net: the applicable net namespace
775 * @ifindex: index of device
777 * Search for an interface by index. Returns NULL if the device
778 * is not found or a pointer to the device. The device returned has
779 * had a reference added and the pointer is safe until the user calls
780 * dev_put to indicate they have finished with it.
783 struct net_device *dev_get_by_index(struct net *net, int ifindex)
785 struct net_device *dev;
788 dev = dev_get_by_index_rcu(net, ifindex);
794 EXPORT_SYMBOL(dev_get_by_index);
797 * dev_getbyhwaddr_rcu - find a device by its hardware address
798 * @net: the applicable net namespace
799 * @type: media type of device
800 * @ha: hardware address
802 * Search for an interface by MAC address. Returns NULL if the device
803 * is not found or a pointer to the device.
804 * The caller must hold RCU or RTNL.
805 * The returned device has not had its ref count increased
806 * and the caller must therefore be careful about locking
810 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
813 struct net_device *dev;
815 for_each_netdev_rcu(net, dev)
816 if (dev->type == type &&
817 !memcmp(dev->dev_addr, ha, dev->addr_len))
822 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
824 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
826 struct net_device *dev;
829 for_each_netdev(net, dev)
830 if (dev->type == type)
835 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
837 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
839 struct net_device *dev, *ret = NULL;
842 for_each_netdev_rcu(net, dev)
843 if (dev->type == type) {
851 EXPORT_SYMBOL(dev_getfirstbyhwtype);
854 * dev_get_by_flags_rcu - find any device with given flags
855 * @net: the applicable net namespace
856 * @if_flags: IFF_* values
857 * @mask: bitmask of bits in if_flags to check
859 * Search for any interface with the given flags. Returns NULL if a device
860 * is not found or a pointer to the device. Must be called inside
861 * rcu_read_lock(), and result refcount is unchanged.
864 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
867 struct net_device *dev, *ret;
870 for_each_netdev_rcu(net, dev) {
871 if (((dev->flags ^ if_flags) & mask) == 0) {
878 EXPORT_SYMBOL(dev_get_by_flags_rcu);
881 * dev_valid_name - check if name is okay for network device
884 * Network device names need to be valid file names to
885 * to allow sysfs to work. We also disallow any kind of
888 bool dev_valid_name(const char *name)
892 if (strlen(name) >= IFNAMSIZ)
894 if (!strcmp(name, ".") || !strcmp(name, ".."))
898 if (*name == '/' || isspace(*name))
904 EXPORT_SYMBOL(dev_valid_name);
907 * __dev_alloc_name - allocate a name for a device
908 * @net: network namespace to allocate the device name in
909 * @name: name format string
910 * @buf: scratch buffer and result name string
912 * Passed a format string - eg "lt%d" it will try and find a suitable
913 * id. It scans list of devices to build up a free map, then chooses
914 * the first empty slot. The caller must hold the dev_base or rtnl lock
915 * while allocating the name and adding the device in order to avoid
917 * Limited to bits_per_byte * page size devices (ie 32K on most platforms).
918 * Returns the number of the unit assigned or a negative errno code.
921 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
925 const int max_netdevices = 8*PAGE_SIZE;
926 unsigned long *inuse;
927 struct net_device *d;
929 p = strnchr(name, IFNAMSIZ-1, '%');
932 * Verify the string as this thing may have come from
933 * the user. There must be either one "%d" and no other "%"
936 if (p[1] != 'd' || strchr(p + 2, '%'))
939 /* Use one page as a bit array of possible slots */
940 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
944 for_each_netdev(net, d) {
945 if (!sscanf(d->name, name, &i))
947 if (i < 0 || i >= max_netdevices)
950 /* avoid cases where sscanf is not exact inverse of printf */
951 snprintf(buf, IFNAMSIZ, name, i);
952 if (!strncmp(buf, d->name, IFNAMSIZ))
956 i = find_first_zero_bit(inuse, max_netdevices);
957 free_page((unsigned long) inuse);
961 snprintf(buf, IFNAMSIZ, name, i);
962 if (!__dev_get_by_name(net, buf))
965 /* It is possible to run out of possible slots
966 * when the name is long and there isn't enough space left
967 * for the digits, or if all bits are used.
973 * dev_alloc_name - allocate a name for a device
975 * @name: name format string
977 * Passed a format string - eg "lt%d" it will try and find a suitable
978 * id. It scans list of devices to build up a free map, then chooses
979 * the first empty slot. The caller must hold the dev_base or rtnl lock
980 * while allocating the name and adding the device in order to avoid
982 * Limited to bits_per_byte * page size devices (ie 32K on most platforms).
983 * Returns the number of the unit assigned or a negative errno code.
986 int dev_alloc_name(struct net_device *dev, const char *name)
992 BUG_ON(!dev_net(dev));
994 ret = __dev_alloc_name(net, name, buf);
996 strlcpy(dev->name, buf, IFNAMSIZ);
999 EXPORT_SYMBOL(dev_alloc_name);
1001 static int dev_alloc_name_ns(struct net *net,
1002 struct net_device *dev,
1008 ret = __dev_alloc_name(net, name, buf);
1010 strlcpy(dev->name, buf, IFNAMSIZ);
1014 static int dev_get_valid_name(struct net *net,
1015 struct net_device *dev,
1020 if (!dev_valid_name(name))
1023 if (strchr(name, '%'))
1024 return dev_alloc_name_ns(net, dev, name);
1025 else if (__dev_get_by_name(net, name))
1027 else if (dev->name != name)
1028 strlcpy(dev->name, name, IFNAMSIZ);
1034 * dev_change_name - change name of a device
1036 * @newname: name (or format string) must be at least IFNAMSIZ
1038 * Change name of a device, can pass format strings "eth%d".
1041 int dev_change_name(struct net_device *dev, const char *newname)
1043 char oldname[IFNAMSIZ];
1049 BUG_ON(!dev_net(dev));
1052 if (dev->flags & IFF_UP)
1055 write_seqcount_begin(&devnet_rename_seq);
1057 if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1058 write_seqcount_end(&devnet_rename_seq);
1062 memcpy(oldname, dev->name, IFNAMSIZ);
1064 err = dev_get_valid_name(net, dev, newname);
1066 write_seqcount_end(&devnet_rename_seq);
1071 ret = device_rename(&dev->dev, dev->name);
1073 memcpy(dev->name, oldname, IFNAMSIZ);
1074 write_seqcount_end(&devnet_rename_seq);
1078 write_seqcount_end(&devnet_rename_seq);
1080 write_lock_bh(&dev_base_lock);
1081 hlist_del_rcu(&dev->name_hlist);
1082 write_unlock_bh(&dev_base_lock);
1086 write_lock_bh(&dev_base_lock);
1087 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1088 write_unlock_bh(&dev_base_lock);
1090 ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1091 ret = notifier_to_errno(ret);
1094 /* err >= 0 after dev_alloc_name() or stores the first errno */
1097 write_seqcount_begin(&devnet_rename_seq);
1098 memcpy(dev->name, oldname, IFNAMSIZ);
1101 pr_err("%s: name change rollback failed: %d\n",
1110 * dev_set_alias - change ifalias of a device
1112 * @alias: name up to IFALIASZ
1113 * @len: limit of bytes to copy from info
1115 * Set ifalias for a device,
1117 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1123 if (len >= IFALIASZ)
1127 kfree(dev->ifalias);
1128 dev->ifalias = NULL;
1132 new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1135 dev->ifalias = new_ifalias;
1137 strlcpy(dev->ifalias, alias, len+1);
1143 * netdev_features_change - device changes features
1144 * @dev: device to cause notification
1146 * Called to indicate a device has changed features.
1148 void netdev_features_change(struct net_device *dev)
1150 call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1152 EXPORT_SYMBOL(netdev_features_change);
1155 * netdev_state_change - device changes state
1156 * @dev: device to cause notification
1158 * Called to indicate a device has changed state. This function calls
1159 * the notifier chains for netdev_chain and sends a NEWLINK message
1160 * to the routing socket.
1162 void netdev_state_change(struct net_device *dev)
1164 if (dev->flags & IFF_UP) {
1165 call_netdevice_notifiers(NETDEV_CHANGE, dev);
1166 rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1169 EXPORT_SYMBOL(netdev_state_change);
1172 * netdev_notify_peers - notify network peers about existence of @dev
1173 * @dev: network device
1175 * Generate traffic such that interested network peers are aware of
1176 * @dev, such as by generating a gratuitous ARP. This may be used when
1177 * a device wants to inform the rest of the network about some sort of
1178 * reconfiguration such as a failover event or virtual machine
1181 void netdev_notify_peers(struct net_device *dev)
1184 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1187 EXPORT_SYMBOL(netdev_notify_peers);
1189 static int __dev_open(struct net_device *dev)
1191 const struct net_device_ops *ops = dev->netdev_ops;
1196 if (!netif_device_present(dev))
1199 /* Block netpoll from trying to do any rx path servicing.
1200 * If we don't do this there is a chance ndo_poll_controller
1201 * or ndo_poll may be running while we open the device
1203 ret = netpoll_rx_disable(dev);
1207 ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1208 ret = notifier_to_errno(ret);
1212 set_bit(__LINK_STATE_START, &dev->state);
1214 if (ops->ndo_validate_addr)
1215 ret = ops->ndo_validate_addr(dev);
1217 if (!ret && ops->ndo_open)
1218 ret = ops->ndo_open(dev);
1220 netpoll_rx_enable(dev);
1223 clear_bit(__LINK_STATE_START, &dev->state);
1225 dev->flags |= IFF_UP;
1226 net_dmaengine_get();
1227 dev_set_rx_mode(dev);
1229 add_device_randomness(dev->dev_addr, dev->addr_len);
1236 * dev_open - prepare an interface for use.
1237 * @dev: device to open
1239 * Takes a device from down to up state. The device's private open
1240 * function is invoked and then the multicast lists are loaded. Finally
1241 * the device is moved into the up state and a %NETDEV_UP message is
1242 * sent to the netdev notifier chain.
1244 * Calling this function on an active interface is a nop. On a failure
1245 * a negative errno code is returned.
1247 int dev_open(struct net_device *dev)
1251 if (dev->flags & IFF_UP)
1254 ret = __dev_open(dev);
1258 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1259 call_netdevice_notifiers(NETDEV_UP, dev);
1263 EXPORT_SYMBOL(dev_open);
1265 static int __dev_close_many(struct list_head *head)
1267 struct net_device *dev;
1272 list_for_each_entry(dev, head, unreg_list) {
1273 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1275 clear_bit(__LINK_STATE_START, &dev->state);
1277 /* Synchronize to scheduled poll. We cannot touch poll list, it
1278 * can be even on different cpu. So just clear netif_running().
1280 * dev->stop() will invoke napi_disable() on all of it's
1281 * napi_struct instances on this device.
1283 smp_mb__after_clear_bit(); /* Commit netif_running(). */
1286 dev_deactivate_many(head);
1288 list_for_each_entry(dev, head, unreg_list) {
1289 const struct net_device_ops *ops = dev->netdev_ops;
1292 * Call the device specific close. This cannot fail.
1293 * Only if device is UP
1295 * We allow it to be called even after a DETACH hot-plug
1301 dev->flags &= ~IFF_UP;
1302 net_dmaengine_put();
1308 static int __dev_close(struct net_device *dev)
1313 /* Temporarily disable netpoll until the interface is down */
1314 retval = netpoll_rx_disable(dev);
1318 list_add(&dev->unreg_list, &single);
1319 retval = __dev_close_many(&single);
1322 netpoll_rx_enable(dev);
1326 static int dev_close_many(struct list_head *head)
1328 struct net_device *dev, *tmp;
1329 LIST_HEAD(tmp_list);
1331 list_for_each_entry_safe(dev, tmp, head, unreg_list)
1332 if (!(dev->flags & IFF_UP))
1333 list_move(&dev->unreg_list, &tmp_list);
1335 __dev_close_many(head);
1337 list_for_each_entry(dev, head, unreg_list) {
1338 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1339 call_netdevice_notifiers(NETDEV_DOWN, dev);
1342 /* rollback_registered_many needs the complete original list */
1343 list_splice(&tmp_list, head);
1348 * dev_close - shutdown an interface.
1349 * @dev: device to shutdown
1351 * This function moves an active device into down state. A
1352 * %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1353 * is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1356 int dev_close(struct net_device *dev)
1359 if (dev->flags & IFF_UP) {
1362 /* Block netpoll rx while the interface is going down */
1363 ret = netpoll_rx_disable(dev);
1367 list_add(&dev->unreg_list, &single);
1368 dev_close_many(&single);
1371 netpoll_rx_enable(dev);
1375 EXPORT_SYMBOL(dev_close);
1379 * dev_disable_lro - disable Large Receive Offload on a device
1382 * Disable Large Receive Offload (LRO) on a net device. Must be
1383 * called under RTNL. This is needed if received packets may be
1384 * forwarded to another interface.
1386 void dev_disable_lro(struct net_device *dev)
1389 * If we're trying to disable lro on a vlan device
1390 * use the underlying physical device instead
1392 if (is_vlan_dev(dev))
1393 dev = vlan_dev_real_dev(dev);
1395 dev->wanted_features &= ~NETIF_F_LRO;
1396 netdev_update_features(dev);
1398 if (unlikely(dev->features & NETIF_F_LRO))
1399 netdev_WARN(dev, "failed to disable LRO!\n");
1401 EXPORT_SYMBOL(dev_disable_lro);
1404 static int dev_boot_phase = 1;
1407 * register_netdevice_notifier - register a network notifier block
1410 * Register a notifier to be called when network device events occur.
1411 * The notifier passed is linked into the kernel structures and must
1412 * not be reused until it has been unregistered. A negative errno code
1413 * is returned on a failure.
1415 * When registered all registration and up events are replayed
1416 * to the new notifier to allow device to have a race free
1417 * view of the network device list.
1420 int register_netdevice_notifier(struct notifier_block *nb)
1422 struct net_device *dev;
1423 struct net_device *last;
1428 err = raw_notifier_chain_register(&netdev_chain, nb);
1434 for_each_netdev(net, dev) {
1435 err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1436 err = notifier_to_errno(err);
1440 if (!(dev->flags & IFF_UP))
1443 nb->notifier_call(nb, NETDEV_UP, dev);
1454 for_each_netdev(net, dev) {
1458 if (dev->flags & IFF_UP) {
1459 nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1460 nb->notifier_call(nb, NETDEV_DOWN, dev);
1462 nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1467 raw_notifier_chain_unregister(&netdev_chain, nb);
1470 EXPORT_SYMBOL(register_netdevice_notifier);
1473 * unregister_netdevice_notifier - unregister a network notifier block
1476 * Unregister a notifier previously registered by
1477 * register_netdevice_notifier(). The notifier is unlinked into the
1478 * kernel structures and may then be reused. A negative errno code
1479 * is returned on a failure.
1481 * After unregistering unregister and down device events are synthesized
1482 * for all devices on the device list to the removed notifier to remove
1483 * the need for special case cleanup code.
1486 int unregister_netdevice_notifier(struct notifier_block *nb)
1488 struct net_device *dev;
1493 err = raw_notifier_chain_unregister(&netdev_chain, nb);
1498 for_each_netdev(net, dev) {
1499 if (dev->flags & IFF_UP) {
1500 nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1501 nb->notifier_call(nb, NETDEV_DOWN, dev);
1503 nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1510 EXPORT_SYMBOL(unregister_netdevice_notifier);
1513 * call_netdevice_notifiers - call all network notifier blocks
1514 * @val: value passed unmodified to notifier function
1515 * @dev: net_device pointer passed unmodified to notifier function
1517 * Call all network notifier blocks. Parameters and return value
1518 * are as for raw_notifier_call_chain().
1521 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1524 return raw_notifier_call_chain(&netdev_chain, val, dev);
1526 EXPORT_SYMBOL(call_netdevice_notifiers);
1528 static struct static_key netstamp_needed __read_mostly;
1529 #ifdef HAVE_JUMP_LABEL
1530 /* We are not allowed to call static_key_slow_dec() from irq context
1531 * If net_disable_timestamp() is called from irq context, defer the
1532 * static_key_slow_dec() calls.
1534 static atomic_t netstamp_needed_deferred;
1537 void net_enable_timestamp(void)
1539 #ifdef HAVE_JUMP_LABEL
1540 int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
1544 static_key_slow_dec(&netstamp_needed);
1548 static_key_slow_inc(&netstamp_needed);
1550 EXPORT_SYMBOL(net_enable_timestamp);
1552 void net_disable_timestamp(void)
1554 #ifdef HAVE_JUMP_LABEL
1555 if (in_interrupt()) {
1556 atomic_inc(&netstamp_needed_deferred);
1560 static_key_slow_dec(&netstamp_needed);
1562 EXPORT_SYMBOL(net_disable_timestamp);
1564 static inline void net_timestamp_set(struct sk_buff *skb)
1566 skb->tstamp.tv64 = 0;
1567 if (static_key_false(&netstamp_needed))
1568 __net_timestamp(skb);
1571 #define net_timestamp_check(COND, SKB) \
1572 if (static_key_false(&netstamp_needed)) { \
1573 if ((COND) && !(SKB)->tstamp.tv64) \
1574 __net_timestamp(SKB); \
1577 static inline bool is_skb_forwardable(struct net_device *dev,
1578 struct sk_buff *skb)
1582 if (!(dev->flags & IFF_UP))
1585 len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1586 if (skb->len <= len)
1589 /* if TSO is enabled, we don't care about the length as the packet
1590 * could be forwarded without being segmented before
1592 if (skb_is_gso(skb))
1599 * dev_forward_skb - loopback an skb to another netif
1601 * @dev: destination network device
1602 * @skb: buffer to forward
1605 * NET_RX_SUCCESS (no congestion)
1606 * NET_RX_DROP (packet was dropped, but freed)
1608 * dev_forward_skb can be used for injecting an skb from the
1609 * start_xmit function of one device into the receive queue
1610 * of another device.
1612 * The receiving device may be in another namespace, so
1613 * we have to clear all information in the skb that could
1614 * impact namespace isolation.
1616 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1618 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
1619 if (skb_copy_ubufs(skb, GFP_ATOMIC)) {
1620 atomic_long_inc(&dev->rx_dropped);
1628 if (unlikely(!is_skb_forwardable(dev, skb))) {
1629 atomic_long_inc(&dev->rx_dropped);
1636 skb->tstamp.tv64 = 0;
1637 skb->pkt_type = PACKET_HOST;
1638 skb->protocol = eth_type_trans(skb, dev);
1642 nf_reset_trace(skb);
1643 return netif_rx(skb);
1645 EXPORT_SYMBOL_GPL(dev_forward_skb);
1647 static inline int deliver_skb(struct sk_buff *skb,
1648 struct packet_type *pt_prev,
1649 struct net_device *orig_dev)
1651 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
1653 atomic_inc(&skb->users);
1654 return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1657 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
1659 if (!ptype->af_packet_priv || !skb->sk)
1662 if (ptype->id_match)
1663 return ptype->id_match(ptype, skb->sk);
1664 else if ((struct sock *)ptype->af_packet_priv == skb->sk)
1671 * Support routine. Sends outgoing frames to any network
1672 * taps currently in use.
1675 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1677 struct packet_type *ptype;
1678 struct sk_buff *skb2 = NULL;
1679 struct packet_type *pt_prev = NULL;
1682 list_for_each_entry_rcu(ptype, &ptype_all, list) {
1683 /* Never send packets back to the socket
1684 * they originated from - MvS (miquels@drinkel.ow.org)
1686 if ((ptype->dev == dev || !ptype->dev) &&
1687 (!skb_loop_sk(ptype, skb))) {
1689 deliver_skb(skb2, pt_prev, skb->dev);
1694 skb2 = skb_clone(skb, GFP_ATOMIC);
1698 net_timestamp_set(skb2);
1700 /* skb->nh should be correctly
1701 set by sender, so that the second statement is
1702 just protection against buggy protocols.
1704 skb_reset_mac_header(skb2);
1706 if (skb_network_header(skb2) < skb2->data ||
1707 skb2->network_header > skb2->tail) {
1708 net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
1709 ntohs(skb2->protocol),
1711 skb_reset_network_header(skb2);
1714 skb2->transport_header = skb2->network_header;
1715 skb2->pkt_type = PACKET_OUTGOING;
1720 pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
1725 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1726 * @dev: Network device
1727 * @txq: number of queues available
1729 * If real_num_tx_queues is changed the tc mappings may no longer be
1730 * valid. To resolve this verify the tc mapping remains valid and if
1731 * not NULL the mapping. With no priorities mapping to this
1732 * offset/count pair it will no longer be used. In the worst case TC0
1733 * is invalid nothing can be done so disable priority mappings. If is
1734 * expected that drivers will fix this mapping if they can before
1735 * calling netif_set_real_num_tx_queues.
1737 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1740 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
1742 /* If TC0 is invalidated disable TC mapping */
1743 if (tc->offset + tc->count > txq) {
1744 pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1749 /* Invalidated prio to tc mappings set to TC0 */
1750 for (i = 1; i < TC_BITMASK + 1; i++) {
1751 int q = netdev_get_prio_tc_map(dev, i);
1753 tc = &dev->tc_to_txq[q];
1754 if (tc->offset + tc->count > txq) {
1755 pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
1757 netdev_set_prio_tc_map(dev, i, 0);
1763 static DEFINE_MUTEX(xps_map_mutex);
1764 #define xmap_dereference(P) \
1765 rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
1767 static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
1770 struct xps_map *map = NULL;
1774 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1776 for (pos = 0; map && pos < map->len; pos++) {
1777 if (map->queues[pos] == index) {
1779 map->queues[pos] = map->queues[--map->len];
1781 RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1782 kfree_rcu(map, rcu);
1792 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1794 struct xps_dev_maps *dev_maps;
1796 bool active = false;
1798 mutex_lock(&xps_map_mutex);
1799 dev_maps = xmap_dereference(dev->xps_maps);
1804 for_each_possible_cpu(cpu) {
1805 for (i = index; i < dev->num_tx_queues; i++) {
1806 if (!remove_xps_queue(dev_maps, cpu, i))
1809 if (i == dev->num_tx_queues)
1814 RCU_INIT_POINTER(dev->xps_maps, NULL);
1815 kfree_rcu(dev_maps, rcu);
1818 for (i = index; i < dev->num_tx_queues; i++)
1819 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
1823 mutex_unlock(&xps_map_mutex);
1826 static struct xps_map *expand_xps_map(struct xps_map *map,
1829 struct xps_map *new_map;
1830 int alloc_len = XPS_MIN_MAP_ALLOC;
1833 for (pos = 0; map && pos < map->len; pos++) {
1834 if (map->queues[pos] != index)
1839 /* Need to add queue to this CPU's existing map */
1841 if (pos < map->alloc_len)
1844 alloc_len = map->alloc_len * 2;
1847 /* Need to allocate new map to store queue on this CPU's map */
1848 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
1853 for (i = 0; i < pos; i++)
1854 new_map->queues[i] = map->queues[i];
1855 new_map->alloc_len = alloc_len;
1861 int netif_set_xps_queue(struct net_device *dev, struct cpumask *mask, u16 index)
1863 struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
1864 struct xps_map *map, *new_map;
1865 int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
1866 int cpu, numa_node_id = -2;
1867 bool active = false;
1869 mutex_lock(&xps_map_mutex);
1871 dev_maps = xmap_dereference(dev->xps_maps);
1873 /* allocate memory for queue storage */
1874 for_each_online_cpu(cpu) {
1875 if (!cpumask_test_cpu(cpu, mask))
1879 new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
1880 if (!new_dev_maps) {
1881 mutex_unlock(&xps_map_mutex);
1885 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
1888 map = expand_xps_map(map, cpu, index);
1892 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1896 goto out_no_new_maps;
1898 for_each_possible_cpu(cpu) {
1899 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
1900 /* add queue to CPU maps */
1903 map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1904 while ((pos < map->len) && (map->queues[pos] != index))
1907 if (pos == map->len)
1908 map->queues[map->len++] = index;
1910 if (numa_node_id == -2)
1911 numa_node_id = cpu_to_node(cpu);
1912 else if (numa_node_id != cpu_to_node(cpu))
1915 } else if (dev_maps) {
1916 /* fill in the new device map from the old device map */
1917 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1918 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1923 rcu_assign_pointer(dev->xps_maps, new_dev_maps);
1925 /* Cleanup old maps */
1927 for_each_possible_cpu(cpu) {
1928 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1929 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1930 if (map && map != new_map)
1931 kfree_rcu(map, rcu);
1934 kfree_rcu(dev_maps, rcu);
1937 dev_maps = new_dev_maps;
1941 /* update Tx queue numa node */
1942 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
1943 (numa_node_id >= 0) ? numa_node_id :
1949 /* removes queue from unused CPUs */
1950 for_each_possible_cpu(cpu) {
1951 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu))
1954 if (remove_xps_queue(dev_maps, cpu, index))
1958 /* free map if not active */
1960 RCU_INIT_POINTER(dev->xps_maps, NULL);
1961 kfree_rcu(dev_maps, rcu);
1965 mutex_unlock(&xps_map_mutex);
1969 /* remove any maps that we added */
1970 for_each_possible_cpu(cpu) {
1971 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1972 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
1974 if (new_map && new_map != map)
1978 mutex_unlock(&xps_map_mutex);
1980 kfree(new_dev_maps);
1983 EXPORT_SYMBOL(netif_set_xps_queue);
1987 * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
1988 * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
1990 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
1994 if (txq < 1 || txq > dev->num_tx_queues)
1997 if (dev->reg_state == NETREG_REGISTERED ||
1998 dev->reg_state == NETREG_UNREGISTERING) {
2001 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2007 netif_setup_tc(dev, txq);
2009 if (txq < dev->real_num_tx_queues) {
2010 qdisc_reset_all_tx_gt(dev, txq);
2012 netif_reset_xps_queues_gt(dev, txq);
2017 dev->real_num_tx_queues = txq;
2020 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2024 * netif_set_real_num_rx_queues - set actual number of RX queues used
2025 * @dev: Network device
2026 * @rxq: Actual number of RX queues
2028 * This must be called either with the rtnl_lock held or before
2029 * registration of the net device. Returns 0 on success, or a
2030 * negative error code. If called before registration, it always
2033 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2037 if (rxq < 1 || rxq > dev->num_rx_queues)
2040 if (dev->reg_state == NETREG_REGISTERED) {
2043 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2049 dev->real_num_rx_queues = rxq;
2052 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2056 * netif_get_num_default_rss_queues - default number of RSS queues
2058 * This routine should set an upper limit on the number of RSS queues
2059 * used by default by multiqueue devices.
2061 int netif_get_num_default_rss_queues(void)
2063 return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
2065 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
2067 static inline void __netif_reschedule(struct Qdisc *q)
2069 struct softnet_data *sd;
2070 unsigned long flags;
2072 local_irq_save(flags);
2073 sd = &__get_cpu_var(softnet_data);
2074 q->next_sched = NULL;
2075 *sd->output_queue_tailp = q;
2076 sd->output_queue_tailp = &q->next_sched;
2077 raise_softirq_irqoff(NET_TX_SOFTIRQ);
2078 local_irq_restore(flags);
2081 void __netif_schedule(struct Qdisc *q)
2083 if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
2084 __netif_reschedule(q);
2086 EXPORT_SYMBOL(__netif_schedule);
2088 void dev_kfree_skb_irq(struct sk_buff *skb)
2090 if (atomic_dec_and_test(&skb->users)) {
2091 struct softnet_data *sd;
2092 unsigned long flags;
2094 local_irq_save(flags);
2095 sd = &__get_cpu_var(softnet_data);
2096 skb->next = sd->completion_queue;
2097 sd->completion_queue = skb;
2098 raise_softirq_irqoff(NET_TX_SOFTIRQ);
2099 local_irq_restore(flags);
2102 EXPORT_SYMBOL(dev_kfree_skb_irq);
2104 void dev_kfree_skb_any(struct sk_buff *skb)
2106 if (in_irq() || irqs_disabled())
2107 dev_kfree_skb_irq(skb);
2111 EXPORT_SYMBOL(dev_kfree_skb_any);
2115 * netif_device_detach - mark device as removed
2116 * @dev: network device
2118 * Mark device as removed from system and therefore no longer available.
2120 void netif_device_detach(struct net_device *dev)
2122 if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
2123 netif_running(dev)) {
2124 netif_tx_stop_all_queues(dev);
2127 EXPORT_SYMBOL(netif_device_detach);
2130 * netif_device_attach - mark device as attached
2131 * @dev: network device
2133 * Mark device as attached from system and restart if needed.
2135 void netif_device_attach(struct net_device *dev)
2137 if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
2138 netif_running(dev)) {
2139 netif_tx_wake_all_queues(dev);
2140 __netdev_watchdog_up(dev);
2143 EXPORT_SYMBOL(netif_device_attach);
2145 static void skb_warn_bad_offload(const struct sk_buff *skb)
2147 static const netdev_features_t null_features = 0;
2148 struct net_device *dev = skb->dev;
2149 const char *driver = "";
2151 if (!net_ratelimit())
2154 if (dev && dev->dev.parent)
2155 driver = dev_driver_string(dev->dev.parent);
2157 WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
2158 "gso_type=%d ip_summed=%d\n",
2159 driver, dev ? &dev->features : &null_features,
2160 skb->sk ? &skb->sk->sk_route_caps : &null_features,
2161 skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
2162 skb_shinfo(skb)->gso_type, skb->ip_summed);
2166 * Invalidate hardware checksum when packet is to be mangled, and
2167 * complete checksum manually on outgoing path.
2169 int skb_checksum_help(struct sk_buff *skb)
2172 int ret = 0, offset;
2174 if (skb->ip_summed == CHECKSUM_COMPLETE)
2175 goto out_set_summed;
2177 if (unlikely(skb_shinfo(skb)->gso_size)) {
2178 skb_warn_bad_offload(skb);
2182 /* Before computing a checksum, we should make sure no frag could
2183 * be modified by an external entity : checksum could be wrong.
2185 if (skb_has_shared_frag(skb)) {
2186 ret = __skb_linearize(skb);
2191 offset = skb_checksum_start_offset(skb);
2192 BUG_ON(offset >= skb_headlen(skb));
2193 csum = skb_checksum(skb, offset, skb->len - offset, 0);
2195 offset += skb->csum_offset;
2196 BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
2198 if (skb_cloned(skb) &&
2199 !skb_clone_writable(skb, offset + sizeof(__sum16))) {
2200 ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
2205 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2207 skb->ip_summed = CHECKSUM_NONE;
2211 EXPORT_SYMBOL(skb_checksum_help);
2214 * skb_mac_gso_segment - mac layer segmentation handler.
2215 * @skb: buffer to segment
2216 * @features: features for the output path (see dev->features)
2218 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
2219 netdev_features_t features)
2221 struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
2222 struct packet_offload *ptype;
2223 __be16 type = skb->protocol;
2224 int vlan_depth = ETH_HLEN;
2226 while (type == htons(ETH_P_8021Q)) {
2227 struct vlan_hdr *vh;
2229 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
2230 return ERR_PTR(-EINVAL);
2232 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
2233 type = vh->h_vlan_encapsulated_proto;
2234 vlan_depth += VLAN_HLEN;
2237 __skb_pull(skb, skb->mac_len);
2240 list_for_each_entry_rcu(ptype, &offload_base, list) {
2241 if (ptype->type == type && ptype->callbacks.gso_segment) {
2242 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2245 err = ptype->callbacks.gso_send_check(skb);
2246 segs = ERR_PTR(err);
2247 if (err || skb_gso_ok(skb, features))
2249 __skb_push(skb, (skb->data -
2250 skb_network_header(skb)));
2252 segs = ptype->callbacks.gso_segment(skb, features);
2258 __skb_push(skb, skb->data - skb_mac_header(skb));
2262 EXPORT_SYMBOL(skb_mac_gso_segment);
2265 /* openvswitch calls this on rx path, so we need a different check.
2267 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
2270 return skb->ip_summed != CHECKSUM_PARTIAL;
2272 return skb->ip_summed == CHECKSUM_NONE;
2276 * __skb_gso_segment - Perform segmentation on skb.
2277 * @skb: buffer to segment
2278 * @features: features for the output path (see dev->features)
2279 * @tx_path: whether it is called in TX path
2281 * This function segments the given skb and returns a list of segments.
2283 * It may return NULL if the skb requires no segmentation. This is
2284 * only possible when GSO is used for verifying header integrity.
2286 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
2287 netdev_features_t features, bool tx_path)
2289 if (unlikely(skb_needs_check(skb, tx_path))) {
2292 skb_warn_bad_offload(skb);
2294 if (skb_header_cloned(skb) &&
2295 (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
2296 return ERR_PTR(err);
2299 SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2300 skb_reset_mac_header(skb);
2301 skb_reset_mac_len(skb);
2303 return skb_mac_gso_segment(skb, features);
2305 EXPORT_SYMBOL(__skb_gso_segment);
2307 /* Take action when hardware reception checksum errors are detected. */
2309 void netdev_rx_csum_fault(struct net_device *dev)
2311 if (net_ratelimit()) {
2312 pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2316 EXPORT_SYMBOL(netdev_rx_csum_fault);
2319 /* Actually, we should eliminate this check as soon as we know, that:
2320 * 1. IOMMU is present and allows to map all the memory.
2321 * 2. No high memory really exists on this machine.
2324 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
2326 #ifdef CONFIG_HIGHMEM
2328 if (!(dev->features & NETIF_F_HIGHDMA)) {
2329 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2330 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2331 if (PageHighMem(skb_frag_page(frag)))
2336 if (PCI_DMA_BUS_IS_PHYS) {
2337 struct device *pdev = dev->dev.parent;
2341 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2342 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2343 dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2344 if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
2353 void (*destructor)(struct sk_buff *skb);
2356 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
2358 static void dev_gso_skb_destructor(struct sk_buff *skb)
2360 struct dev_gso_cb *cb;
2363 struct sk_buff *nskb = skb->next;
2365 skb->next = nskb->next;
2368 } while (skb->next);
2370 cb = DEV_GSO_CB(skb);
2372 cb->destructor(skb);
2376 * dev_gso_segment - Perform emulated hardware segmentation on skb.
2377 * @skb: buffer to segment
2378 * @features: device features as applicable to this skb
2380 * This function segments the given skb and stores the list of segments
2383 static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2385 struct sk_buff *segs;
2387 segs = skb_gso_segment(skb, features);
2389 /* Verifying header integrity only. */
2394 return PTR_ERR(segs);
2397 DEV_GSO_CB(skb)->destructor = skb->destructor;
2398 skb->destructor = dev_gso_skb_destructor;
2403 static bool can_checksum_protocol(netdev_features_t features, __be16 protocol)
2405 return ((features & NETIF_F_GEN_CSUM) ||
2406 ((features & NETIF_F_V4_CSUM) &&
2407 protocol == htons(ETH_P_IP)) ||
2408 ((features & NETIF_F_V6_CSUM) &&
2409 protocol == htons(ETH_P_IPV6)) ||
2410 ((features & NETIF_F_FCOE_CRC) &&
2411 protocol == htons(ETH_P_FCOE)));
2414 static netdev_features_t harmonize_features(struct sk_buff *skb,
2415 __be16 protocol, netdev_features_t features)
2417 if (skb->ip_summed != CHECKSUM_NONE &&
2418 !can_checksum_protocol(features, protocol)) {
2419 features &= ~NETIF_F_ALL_CSUM;
2420 features &= ~NETIF_F_SG;
2421 } else if (illegal_highdma(skb->dev, skb)) {
2422 features &= ~NETIF_F_SG;
2428 netdev_features_t netif_skb_features(struct sk_buff *skb)
2430 __be16 protocol = skb->protocol;
2431 netdev_features_t features = skb->dev->features;
2433 if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
2434 features &= ~NETIF_F_GSO_MASK;
2436 if (protocol == htons(ETH_P_8021Q)) {
2437 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
2438 protocol = veh->h_vlan_encapsulated_proto;
2439 } else if (!vlan_tx_tag_present(skb)) {
2440 return harmonize_features(skb, protocol, features);
2443 features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_TX);
2445 if (protocol != htons(ETH_P_8021Q)) {
2446 return harmonize_features(skb, protocol, features);
2448 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
2449 NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
2450 return harmonize_features(skb, protocol, features);
2453 EXPORT_SYMBOL(netif_skb_features);
2456 * Returns true if either:
2457 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2458 * 2. skb is fragmented and the device does not support SG.
2460 static inline int skb_needs_linearize(struct sk_buff *skb,
2463 return skb_is_nonlinear(skb) &&
2464 ((skb_has_frag_list(skb) &&
2465 !(features & NETIF_F_FRAGLIST)) ||
2466 (skb_shinfo(skb)->nr_frags &&
2467 !(features & NETIF_F_SG)));
2470 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2471 struct netdev_queue *txq)
2473 const struct net_device_ops *ops = dev->netdev_ops;
2474 int rc = NETDEV_TX_OK;
2475 unsigned int skb_len;
2477 if (likely(!skb->next)) {
2478 netdev_features_t features;
2481 * If device doesn't need skb->dst, release it right now while
2482 * its hot in this cpu cache
2484 if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2487 features = netif_skb_features(skb);
2489 if (vlan_tx_tag_present(skb) &&
2490 !(features & NETIF_F_HW_VLAN_TX)) {
2491 skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
2498 /* If encapsulation offload request, verify we are testing
2499 * hardware encapsulation features instead of standard
2500 * features for the netdev
2502 if (skb->encapsulation)
2503 features &= dev->hw_enc_features;
2505 if (netif_needs_gso(skb, features)) {
2506 if (unlikely(dev_gso_segment(skb, features)))
2511 if (skb_needs_linearize(skb, features) &&
2512 __skb_linearize(skb))
2515 /* If packet is not checksummed and device does not
2516 * support checksumming for this protocol, complete
2517 * checksumming here.
2519 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2520 if (skb->encapsulation)
2521 skb_set_inner_transport_header(skb,
2522 skb_checksum_start_offset(skb));
2524 skb_set_transport_header(skb,
2525 skb_checksum_start_offset(skb));
2526 if (!(features & NETIF_F_ALL_CSUM) &&
2527 skb_checksum_help(skb))
2532 if (!list_empty(&ptype_all))
2533 dev_queue_xmit_nit(skb, dev);
2536 rc = ops->ndo_start_xmit(skb, dev);
2537 trace_net_dev_xmit(skb, rc, dev, skb_len);
2538 if (rc == NETDEV_TX_OK)
2539 txq_trans_update(txq);
2545 struct sk_buff *nskb = skb->next;
2547 skb->next = nskb->next;
2551 * If device doesn't need nskb->dst, release it right now while
2552 * its hot in this cpu cache
2554 if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2557 if (!list_empty(&ptype_all))
2558 dev_queue_xmit_nit(nskb, dev);
2560 skb_len = nskb->len;
2561 rc = ops->ndo_start_xmit(nskb, dev);
2562 trace_net_dev_xmit(nskb, rc, dev, skb_len);
2563 if (unlikely(rc != NETDEV_TX_OK)) {
2564 if (rc & ~NETDEV_TX_MASK)
2565 goto out_kfree_gso_skb;
2566 nskb->next = skb->next;
2570 txq_trans_update(txq);
2571 if (unlikely(netif_xmit_stopped(txq) && skb->next))
2572 return NETDEV_TX_BUSY;
2573 } while (skb->next);
2576 if (likely(skb->next == NULL))
2577 skb->destructor = DEV_GSO_CB(skb)->destructor;
2584 static void qdisc_pkt_len_init(struct sk_buff *skb)
2586 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2588 qdisc_skb_cb(skb)->pkt_len = skb->len;
2590 /* To get more precise estimation of bytes sent on wire,
2591 * we add to pkt_len the headers size of all segments
2593 if (shinfo->gso_size) {
2594 unsigned int hdr_len;
2596 /* mac layer + network layer */
2597 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
2599 /* + transport layer */
2600 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
2601 hdr_len += tcp_hdrlen(skb);
2603 hdr_len += sizeof(struct udphdr);
2604 qdisc_skb_cb(skb)->pkt_len += (shinfo->gso_segs - 1) * hdr_len;
2608 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2609 struct net_device *dev,
2610 struct netdev_queue *txq)
2612 spinlock_t *root_lock = qdisc_lock(q);
2616 qdisc_pkt_len_init(skb);
2617 qdisc_calculate_pkt_len(skb, q);
2619 * Heuristic to force contended enqueues to serialize on a
2620 * separate lock before trying to get qdisc main lock.
2621 * This permits __QDISC_STATE_RUNNING owner to get the lock more often
2622 * and dequeue packets faster.
2624 contended = qdisc_is_running(q);
2625 if (unlikely(contended))
2626 spin_lock(&q->busylock);
2628 spin_lock(root_lock);
2629 if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2632 } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2633 qdisc_run_begin(q)) {
2635 * This is a work-conserving queue; there are no old skbs
2636 * waiting to be sent out; and the qdisc is not running -
2637 * xmit the skb directly.
2639 if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2642 qdisc_bstats_update(q, skb);
2644 if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
2645 if (unlikely(contended)) {
2646 spin_unlock(&q->busylock);
2653 rc = NET_XMIT_SUCCESS;
2656 rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2657 if (qdisc_run_begin(q)) {
2658 if (unlikely(contended)) {
2659 spin_unlock(&q->busylock);
2665 spin_unlock(root_lock);
2666 if (unlikely(contended))
2667 spin_unlock(&q->busylock);
2671 #if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
2672 static void skb_update_prio(struct sk_buff *skb)
2674 struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
2676 if (!skb->priority && skb->sk && map) {
2677 unsigned int prioidx = skb->sk->sk_cgrp_prioidx;
2679 if (prioidx < map->priomap_len)
2680 skb->priority = map->priomap[prioidx];
2684 #define skb_update_prio(skb)
2687 static DEFINE_PER_CPU(int, xmit_recursion);
2688 #define RECURSION_LIMIT 10
2691 * dev_loopback_xmit - loop back @skb
2692 * @skb: buffer to transmit
2694 int dev_loopback_xmit(struct sk_buff *skb)
2696 skb_reset_mac_header(skb);
2697 __skb_pull(skb, skb_network_offset(skb));
2698 skb->pkt_type = PACKET_LOOPBACK;
2699 skb->ip_summed = CHECKSUM_UNNECESSARY;
2700 WARN_ON(!skb_dst(skb));
2705 EXPORT_SYMBOL(dev_loopback_xmit);
2708 * dev_queue_xmit - transmit a buffer
2709 * @skb: buffer to transmit
2711 * Queue a buffer for transmission to a network device. The caller must
2712 * have set the device and priority and built the buffer before calling
2713 * this function. The function can be called from an interrupt.
2715 * A negative errno code is returned on a failure. A success does not
2716 * guarantee the frame will be transmitted as it may be dropped due
2717 * to congestion or traffic shaping.
2719 * -----------------------------------------------------------------------------------
2720 * I notice this method can also return errors from the queue disciplines,
2721 * including NET_XMIT_DROP, which is a positive value. So, errors can also
2724 * Regardless of the return value, the skb is consumed, so it is currently
2725 * difficult to retry a send to this method. (You can bump the ref count
2726 * before sending to hold a reference for retry if you are careful.)
2728 * When calling this method, interrupts MUST be enabled. This is because
2729 * the BH enable code must have IRQs enabled so that it will not deadlock.
2732 int dev_queue_xmit(struct sk_buff *skb)
2734 struct net_device *dev = skb->dev;
2735 struct netdev_queue *txq;
2739 skb_reset_mac_header(skb);
2741 /* Disable soft irqs for various locks below. Also
2742 * stops preemption for RCU.
2746 skb_update_prio(skb);
2748 txq = netdev_pick_tx(dev, skb);
2749 q = rcu_dereference_bh(txq->qdisc);
2751 #ifdef CONFIG_NET_CLS_ACT
2752 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2754 trace_net_dev_queue(skb);
2756 rc = __dev_xmit_skb(skb, q, dev, txq);
2760 /* The device has no queue. Common case for software devices:
2761 loopback, all the sorts of tunnels...
2763 Really, it is unlikely that netif_tx_lock protection is necessary
2764 here. (f.e. loopback and IP tunnels are clean ignoring statistics
2766 However, it is possible, that they rely on protection
2769 Check this and shot the lock. It is not prone from deadlocks.
2770 Either shot noqueue qdisc, it is even simpler 8)
2772 if (dev->flags & IFF_UP) {
2773 int cpu = smp_processor_id(); /* ok because BHs are off */
2775 if (txq->xmit_lock_owner != cpu) {
2777 if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
2778 goto recursion_alert;
2780 HARD_TX_LOCK(dev, txq, cpu);
2782 if (!netif_xmit_stopped(txq)) {
2783 __this_cpu_inc(xmit_recursion);
2784 rc = dev_hard_start_xmit(skb, dev, txq);
2785 __this_cpu_dec(xmit_recursion);
2786 if (dev_xmit_complete(rc)) {
2787 HARD_TX_UNLOCK(dev, txq);
2791 HARD_TX_UNLOCK(dev, txq);
2792 net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
2795 /* Recursion is detected! It is possible,
2799 net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
2805 rcu_read_unlock_bh();
2810 rcu_read_unlock_bh();
2813 EXPORT_SYMBOL(dev_queue_xmit);
2816 /*=======================================================================
2818 =======================================================================*/
2820 int netdev_max_backlog __read_mostly = 1000;
2821 EXPORT_SYMBOL(netdev_max_backlog);
2823 int netdev_tstamp_prequeue __read_mostly = 1;
2824 int netdev_budget __read_mostly = 300;
2825 int weight_p __read_mostly = 64; /* old backlog weight */
2827 /* Called with irq disabled */
2828 static inline void ____napi_schedule(struct softnet_data *sd,
2829 struct napi_struct *napi)
2831 list_add_tail(&napi->poll_list, &sd->poll_list);
2832 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
2837 /* One global table that all flow-based protocols share. */
2838 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2839 EXPORT_SYMBOL(rps_sock_flow_table);
2841 struct static_key rps_needed __read_mostly;
2843 static struct rps_dev_flow *
2844 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2845 struct rps_dev_flow *rflow, u16 next_cpu)
2847 if (next_cpu != RPS_NO_CPU) {
2848 #ifdef CONFIG_RFS_ACCEL
2849 struct netdev_rx_queue *rxqueue;
2850 struct rps_dev_flow_table *flow_table;
2851 struct rps_dev_flow *old_rflow;
2856 /* Should we steer this flow to a different hardware queue? */
2857 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
2858 !(dev->features & NETIF_F_NTUPLE))
2860 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
2861 if (rxq_index == skb_get_rx_queue(skb))
2864 rxqueue = dev->_rx + rxq_index;
2865 flow_table = rcu_dereference(rxqueue->rps_flow_table);
2868 flow_id = skb->rxhash & flow_table->mask;
2869 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
2870 rxq_index, flow_id);
2874 rflow = &flow_table->flows[flow_id];
2876 if (old_rflow->filter == rflow->filter)
2877 old_rflow->filter = RPS_NO_FILTER;
2881 per_cpu(softnet_data, next_cpu).input_queue_head;
2884 rflow->cpu = next_cpu;
2889 * get_rps_cpu is called from netif_receive_skb and returns the target
2890 * CPU from the RPS map of the receiving queue for a given skb.
2891 * rcu_read_lock must be held on entry.
2893 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2894 struct rps_dev_flow **rflowp)
2896 struct netdev_rx_queue *rxqueue;
2897 struct rps_map *map;
2898 struct rps_dev_flow_table *flow_table;
2899 struct rps_sock_flow_table *sock_flow_table;
2903 if (skb_rx_queue_recorded(skb)) {
2904 u16 index = skb_get_rx_queue(skb);
2905 if (unlikely(index >= dev->real_num_rx_queues)) {
2906 WARN_ONCE(dev->real_num_rx_queues > 1,
2907 "%s received packet on queue %u, but number "
2908 "of RX queues is %u\n",
2909 dev->name, index, dev->real_num_rx_queues);
2912 rxqueue = dev->_rx + index;
2916 map = rcu_dereference(rxqueue->rps_map);
2918 if (map->len == 1 &&
2919 !rcu_access_pointer(rxqueue->rps_flow_table)) {
2920 tcpu = map->cpus[0];
2921 if (cpu_online(tcpu))
2925 } else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
2929 skb_reset_network_header(skb);
2930 if (!skb_get_rxhash(skb))
2933 flow_table = rcu_dereference(rxqueue->rps_flow_table);
2934 sock_flow_table = rcu_dereference(rps_sock_flow_table);
2935 if (flow_table && sock_flow_table) {
2937 struct rps_dev_flow *rflow;
2939 rflow = &flow_table->flows[skb->rxhash & flow_table->mask];
2942 next_cpu = sock_flow_table->ents[skb->rxhash &
2943 sock_flow_table->mask];
2946 * If the desired CPU (where last recvmsg was done) is
2947 * different from current CPU (one in the rx-queue flow
2948 * table entry), switch if one of the following holds:
2949 * - Current CPU is unset (equal to RPS_NO_CPU).
2950 * - Current CPU is offline.
2951 * - The current CPU's queue tail has advanced beyond the
2952 * last packet that was enqueued using this table entry.
2953 * This guarantees that all previous packets for the flow
2954 * have been dequeued, thus preserving in order delivery.
2956 if (unlikely(tcpu != next_cpu) &&
2957 (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
2958 ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
2959 rflow->last_qtail)) >= 0)) {
2961 rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
2964 if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
2972 tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
2974 if (cpu_online(tcpu)) {
2984 #ifdef CONFIG_RFS_ACCEL
2987 * rps_may_expire_flow - check whether an RFS hardware filter may be removed
2988 * @dev: Device on which the filter was set
2989 * @rxq_index: RX queue index
2990 * @flow_id: Flow ID passed to ndo_rx_flow_steer()
2991 * @filter_id: Filter ID returned by ndo_rx_flow_steer()
2993 * Drivers that implement ndo_rx_flow_steer() should periodically call
2994 * this function for each installed filter and remove the filters for
2995 * which it returns %true.
2997 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
2998 u32 flow_id, u16 filter_id)
3000 struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
3001 struct rps_dev_flow_table *flow_table;
3002 struct rps_dev_flow *rflow;
3007 flow_table = rcu_dereference(rxqueue->rps_flow_table);
3008 if (flow_table && flow_id <= flow_table->mask) {
3009 rflow = &flow_table->flows[flow_id];
3010 cpu = ACCESS_ONCE(rflow->cpu);
3011 if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
3012 ((int)(per_cpu(softnet_data, cpu).input_queue_head -
3013 rflow->last_qtail) <
3014 (int)(10 * flow_table->mask)))
3020 EXPORT_SYMBOL(rps_may_expire_flow);
3022 #endif /* CONFIG_RFS_ACCEL */
3024 /* Called from hardirq (IPI) context */
3025 static void rps_trigger_softirq(void *data)
3027 struct softnet_data *sd = data;
3029 ____napi_schedule(sd, &sd->backlog);
3033 #endif /* CONFIG_RPS */
3036 * Check if this softnet_data structure is another cpu one
3037 * If yes, queue it to our IPI list and return 1
3040 static int rps_ipi_queued(struct softnet_data *sd)
3043 struct softnet_data *mysd = &__get_cpu_var(softnet_data);
3046 sd->rps_ipi_next = mysd->rps_ipi_list;
3047 mysd->rps_ipi_list = sd;
3049 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
3052 #endif /* CONFIG_RPS */
3057 * enqueue_to_backlog is called to queue an skb to a per CPU backlog
3058 * queue (may be a remote CPU queue).
3060 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
3061 unsigned int *qtail)
3063 struct softnet_data *sd;
3064 unsigned long flags;
3066 sd = &per_cpu(softnet_data, cpu);
3068 local_irq_save(flags);
3071 if (skb_queue_len(&sd->input_pkt_queue) <= netdev_max_backlog) {
3072 if (skb_queue_len(&sd->input_pkt_queue)) {
3074 __skb_queue_tail(&sd->input_pkt_queue, skb);
3075 input_queue_tail_incr_save(sd, qtail);
3077 local_irq_restore(flags);
3078 return NET_RX_SUCCESS;
3081 /* Schedule NAPI for backlog device
3082 * We can use non atomic operation since we own the queue lock
3084 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
3085 if (!rps_ipi_queued(sd))
3086 ____napi_schedule(sd, &sd->backlog);
3094 local_irq_restore(flags);
3096 atomic_long_inc(&skb->dev->rx_dropped);
3102 * netif_rx - post buffer to the network code
3103 * @skb: buffer to post
3105 * This function receives a packet from a device driver and queues it for
3106 * the upper (protocol) levels to process. It always succeeds. The buffer
3107 * may be dropped during processing for congestion control or by the
3111 * NET_RX_SUCCESS (no congestion)
3112 * NET_RX_DROP (packet was dropped)
3116 int netif_rx(struct sk_buff *skb)
3120 /* if netpoll wants it, pretend we never saw it */
3121 if (netpoll_rx(skb))
3124 net_timestamp_check(netdev_tstamp_prequeue, skb);
3126 trace_netif_rx(skb);
3128 if (static_key_false(&rps_needed)) {
3129 struct rps_dev_flow voidflow, *rflow = &voidflow;
3135 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3137 cpu = smp_processor_id();
3139 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3147 ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
3152 EXPORT_SYMBOL(netif_rx);
3154 int netif_rx_ni(struct sk_buff *skb)
3159 err = netif_rx(skb);
3160 if (local_softirq_pending())
3166 EXPORT_SYMBOL(netif_rx_ni);
3168 static void net_tx_action(struct softirq_action *h)
3170 struct softnet_data *sd = &__get_cpu_var(softnet_data);
3172 if (sd->completion_queue) {
3173 struct sk_buff *clist;
3175 local_irq_disable();
3176 clist = sd->completion_queue;
3177 sd->completion_queue = NULL;
3181 struct sk_buff *skb = clist;
3182 clist = clist->next;
3184 WARN_ON(atomic_read(&skb->users));
3185 trace_kfree_skb(skb, net_tx_action);
3190 if (sd->output_queue) {
3193 local_irq_disable();
3194 head = sd->output_queue;
3195 sd->output_queue = NULL;
3196 sd->output_queue_tailp = &sd->output_queue;
3200 struct Qdisc *q = head;
3201 spinlock_t *root_lock;
3203 head = head->next_sched;
3205 root_lock = qdisc_lock(q);
3206 if (spin_trylock(root_lock)) {
3207 smp_mb__before_clear_bit();
3208 clear_bit(__QDISC_STATE_SCHED,
3211 spin_unlock(root_lock);
3213 if (!test_bit(__QDISC_STATE_DEACTIVATED,
3215 __netif_reschedule(q);
3217 smp_mb__before_clear_bit();
3218 clear_bit(__QDISC_STATE_SCHED,
3226 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
3227 (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3228 /* This hook is defined here for ATM LANE */
3229 int (*br_fdb_test_addr_hook)(struct net_device *dev,
3230 unsigned char *addr) __read_mostly;
3231 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3234 #ifdef CONFIG_NET_CLS_ACT
3235 /* TODO: Maybe we should just force sch_ingress to be compiled in
3236 * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
3237 * a compare and 2 stores extra right now if we dont have it on
3238 * but have CONFIG_NET_CLS_ACT
3239 * NOTE: This doesn't stop any functionality; if you dont have
3240 * the ingress scheduler, you just can't add policies on ingress.
3243 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
3245 struct net_device *dev = skb->dev;
3246 u32 ttl = G_TC_RTTL(skb->tc_verd);
3247 int result = TC_ACT_OK;
3250 if (unlikely(MAX_RED_LOOP < ttl++)) {
3251 net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
3252 skb->skb_iif, dev->ifindex);
3256 skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
3257 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
3260 if (q != &noop_qdisc) {
3261 spin_lock(qdisc_lock(q));
3262 if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
3263 result = qdisc_enqueue_root(skb, q);
3264 spin_unlock(qdisc_lock(q));
3270 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
3271 struct packet_type **pt_prev,
3272 int *ret, struct net_device *orig_dev)
3274 struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
3276 if (!rxq || rxq->qdisc == &noop_qdisc)
3280 *ret = deliver_skb(skb, *pt_prev, orig_dev);
3284 switch (ing_filter(skb, rxq)) {
3298 * netdev_rx_handler_register - register receive handler
3299 * @dev: device to register a handler for
3300 * @rx_handler: receive handler to register
3301 * @rx_handler_data: data pointer that is used by rx handler
3303 * Register a receive hander for a device. This handler will then be
3304 * called from __netif_receive_skb. A negative errno code is returned
3307 * The caller must hold the rtnl_mutex.
3309 * For a general description of rx_handler, see enum rx_handler_result.
3311 int netdev_rx_handler_register(struct net_device *dev,
3312 rx_handler_func_t *rx_handler,
3313 void *rx_handler_data)
3317 if (dev->rx_handler)
3320 /* Note: rx_handler_data must be set before rx_handler */
3321 rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3322 rcu_assign_pointer(dev->rx_handler, rx_handler);
3326 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
3329 * netdev_rx_handler_unregister - unregister receive handler
3330 * @dev: device to unregister a handler from
3332 * Unregister a receive hander from a device.
3334 * The caller must hold the rtnl_mutex.
3336 void netdev_rx_handler_unregister(struct net_device *dev)
3340 RCU_INIT_POINTER(dev->rx_handler, NULL);
3341 /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
3342 * section has a guarantee to see a non NULL rx_handler_data
3346 RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3348 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
3351 * Limit the use of PFMEMALLOC reserves to those protocols that implement
3352 * the special handling of PFMEMALLOC skbs.
3354 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
3356 switch (skb->protocol) {
3357 case __constant_htons(ETH_P_ARP):
3358 case __constant_htons(ETH_P_IP):
3359 case __constant_htons(ETH_P_IPV6):
3360 case __constant_htons(ETH_P_8021Q):
3367 static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
3369 struct packet_type *ptype, *pt_prev;
3370 rx_handler_func_t *rx_handler;
3371 struct net_device *orig_dev;
3372 struct net_device *null_or_dev;
3373 bool deliver_exact = false;
3374 int ret = NET_RX_DROP;
3377 net_timestamp_check(!netdev_tstamp_prequeue, skb);
3379 trace_netif_receive_skb(skb);
3381 /* if we've gotten here through NAPI, check netpoll */
3382 if (netpoll_receive_skb(skb))
3385 orig_dev = skb->dev;
3387 skb_reset_network_header(skb);
3388 if (!skb_transport_header_was_set(skb))
3389 skb_reset_transport_header(skb);
3390 skb_reset_mac_len(skb);
3397 skb->skb_iif = skb->dev->ifindex;
3399 __this_cpu_inc(softnet_data.processed);
3401 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
3402 skb = vlan_untag(skb);
3407 #ifdef CONFIG_NET_CLS_ACT
3408 if (skb->tc_verd & TC_NCLS) {
3409 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
3417 list_for_each_entry_rcu(ptype, &ptype_all, list) {
3418 if (!ptype->dev || ptype->dev == skb->dev) {
3420 ret = deliver_skb(skb, pt_prev, orig_dev);
3426 #ifdef CONFIG_NET_CLS_ACT
3427 skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
3433 if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3436 if (vlan_tx_tag_present(skb)) {
3438 ret = deliver_skb(skb, pt_prev, orig_dev);
3441 if (vlan_do_receive(&skb))
3443 else if (unlikely(!skb))
3447 rx_handler = rcu_dereference(skb->dev->rx_handler);
3450 ret = deliver_skb(skb, pt_prev, orig_dev);
3453 switch (rx_handler(&skb)) {
3454 case RX_HANDLER_CONSUMED:
3455 ret = NET_RX_SUCCESS;
3457 case RX_HANDLER_ANOTHER:
3459 case RX_HANDLER_EXACT:
3460 deliver_exact = true;
3461 case RX_HANDLER_PASS:
3468 if (vlan_tx_nonzero_tag_present(skb))
3469 skb->pkt_type = PACKET_OTHERHOST;
3471 /* deliver only exact match when indicated */
3472 null_or_dev = deliver_exact ? skb->dev : NULL;
3474 type = skb->protocol;
3475 list_for_each_entry_rcu(ptype,
3476 &ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3477 if (ptype->type == type &&
3478 (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
3479 ptype->dev == orig_dev)) {
3481 ret = deliver_skb(skb, pt_prev, orig_dev);
3487 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3490 ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
3493 atomic_long_inc(&skb->dev->rx_dropped);
3495 /* Jamal, now you will not able to escape explaining
3496 * me how you were going to use this. :-)
3507 static int __netif_receive_skb(struct sk_buff *skb)
3511 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
3512 unsigned long pflags = current->flags;
3515 * PFMEMALLOC skbs are special, they should
3516 * - be delivered to SOCK_MEMALLOC sockets only
3517 * - stay away from userspace
3518 * - have bounded memory usage
3520 * Use PF_MEMALLOC as this saves us from propagating the allocation
3521 * context down to all allocation sites.
3523 current->flags |= PF_MEMALLOC;
3524 ret = __netif_receive_skb_core(skb, true);
3525 tsk_restore_flags(current, pflags, PF_MEMALLOC);
3527 ret = __netif_receive_skb_core(skb, false);
3533 * netif_receive_skb - process receive buffer from network
3534 * @skb: buffer to process
3536 * netif_receive_skb() is the main receive data processing function.
3537 * It always succeeds. The buffer may be dropped during processing
3538 * for congestion control or by the protocol layers.
3540 * This function may only be called from softirq context and interrupts
3541 * should be enabled.
3543 * Return values (usually ignored):
3544 * NET_RX_SUCCESS: no congestion
3545 * NET_RX_DROP: packet was dropped
3547 int netif_receive_skb(struct sk_buff *skb)
3549 net_timestamp_check(netdev_tstamp_prequeue, skb);
3551 if (skb_defer_rx_timestamp(skb))
3552 return NET_RX_SUCCESS;
3555 if (static_key_false(&rps_needed)) {
3556 struct rps_dev_flow voidflow, *rflow = &voidflow;
3561 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3564 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3571 return __netif_receive_skb(skb);
3573 EXPORT_SYMBOL(netif_receive_skb);
3575 /* Network device is going away, flush any packets still pending
3576 * Called with irqs disabled.
3578 static void flush_backlog(void *arg)
3580 struct net_device *dev = arg;
3581 struct softnet_data *sd = &__get_cpu_var(softnet_data);
3582 struct sk_buff *skb, *tmp;
3585 skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3586 if (skb->dev == dev) {
3587 __skb_unlink(skb, &sd->input_pkt_queue);
3589 input_queue_head_incr(sd);
3594 skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
3595 if (skb->dev == dev) {
3596 __skb_unlink(skb, &sd->process_queue);
3598 input_queue_head_incr(sd);
3603 static int napi_gro_complete(struct sk_buff *skb)
3605 struct packet_offload *ptype;
3606 __be16 type = skb->protocol;
3607 struct list_head *head = &offload_base;
3610 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
3612 if (NAPI_GRO_CB(skb)->count == 1) {
3613 skb_shinfo(skb)->gso_size = 0;
3618 list_for_each_entry_rcu(ptype, head, list) {
3619 if (ptype->type != type || !ptype->callbacks.gro_complete)
3622 err = ptype->callbacks.gro_complete(skb);
3628 WARN_ON(&ptype->list == head);
3630 return NET_RX_SUCCESS;
3634 return netif_receive_skb(skb);
3637 /* napi->gro_list contains packets ordered by age.
3638 * youngest packets at the head of it.
3639 * Complete skbs in reverse order to reduce latencies.
3641 void napi_gro_flush(struct napi_struct *napi, bool flush_old)
3643 struct sk_buff *skb, *prev = NULL;
3645 /* scan list and build reverse chain */
3646 for (skb = napi->gro_list; skb != NULL; skb = skb->next) {
3651 for (skb = prev; skb; skb = prev) {
3654 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
3658 napi_gro_complete(skb);
3662 napi->gro_list = NULL;
3664 EXPORT_SYMBOL(napi_gro_flush);
3666 static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb)
3669 unsigned int maclen = skb->dev->hard_header_len;
3671 for (p = napi->gro_list; p; p = p->next) {
3672 unsigned long diffs;
3674 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
3675 diffs |= p->vlan_tci ^ skb->vlan_tci;
3676 if (maclen == ETH_HLEN)
3677 diffs |= compare_ether_header(skb_mac_header(p),
3678 skb_gro_mac_header(skb));
3680 diffs = memcmp(skb_mac_header(p),
3681 skb_gro_mac_header(skb),
3683 NAPI_GRO_CB(p)->same_flow = !diffs;
3684 NAPI_GRO_CB(p)->flush = 0;
3688 static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3690 struct sk_buff **pp = NULL;
3691 struct packet_offload *ptype;
3692 __be16 type = skb->protocol;
3693 struct list_head *head = &offload_base;
3695 enum gro_result ret;
3697 if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3700 if (skb_is_gso(skb) || skb_has_frag_list(skb))
3703 gro_list_prepare(napi, skb);
3706 list_for_each_entry_rcu(ptype, head, list) {
3707 if (ptype->type != type || !ptype->callbacks.gro_receive)
3710 skb_set_network_header(skb, skb_gro_offset(skb));
3711 skb_reset_mac_len(skb);
3712 NAPI_GRO_CB(skb)->same_flow = 0;
3713 NAPI_GRO_CB(skb)->flush = 0;
3714 NAPI_GRO_CB(skb)->free = 0;
3716 pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3721 if (&ptype->list == head)
3724 same_flow = NAPI_GRO_CB(skb)->same_flow;
3725 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3728 struct sk_buff *nskb = *pp;
3732 napi_gro_complete(nskb);
3739 if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3743 NAPI_GRO_CB(skb)->count = 1;
3744 NAPI_GRO_CB(skb)->age = jiffies;
3745 skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3746 skb->next = napi->gro_list;
3747 napi->gro_list = skb;
3751 if (skb_headlen(skb) < skb_gro_offset(skb)) {
3752 int grow = skb_gro_offset(skb) - skb_headlen(skb);
3754 BUG_ON(skb->end - skb->tail < grow);
3756 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3759 skb->data_len -= grow;
3761 skb_shinfo(skb)->frags[0].page_offset += grow;
3762 skb_frag_size_sub(&skb_shinfo(skb)->frags[0], grow);
3764 if (unlikely(!skb_frag_size(&skb_shinfo(skb)->frags[0]))) {
3765 skb_frag_unref(skb, 0);
3766 memmove(skb_shinfo(skb)->frags,
3767 skb_shinfo(skb)->frags + 1,
3768 --skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
3781 static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
3785 if (netif_receive_skb(skb))
3793 case GRO_MERGED_FREE:
3794 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
3795 kmem_cache_free(skbuff_head_cache, skb);
3808 static void skb_gro_reset_offset(struct sk_buff *skb)
3810 const struct skb_shared_info *pinfo = skb_shinfo(skb);
3811 const skb_frag_t *frag0 = &pinfo->frags[0];
3813 NAPI_GRO_CB(skb)->data_offset = 0;
3814 NAPI_GRO_CB(skb)->frag0 = NULL;
3815 NAPI_GRO_CB(skb)->frag0_len = 0;
3817 if (skb->mac_header == skb->tail &&
3819 !PageHighMem(skb_frag_page(frag0))) {
3820 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
3821 NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0);
3825 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3827 skb_gro_reset_offset(skb);
3829 return napi_skb_finish(dev_gro_receive(napi, skb), skb);
3831 EXPORT_SYMBOL(napi_gro_receive);
3833 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3835 __skb_pull(skb, skb_headlen(skb));
3836 /* restore the reserve we had after netdev_alloc_skb_ip_align() */
3837 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
3839 skb->dev = napi->dev;
3845 struct sk_buff *napi_get_frags(struct napi_struct *napi)
3847 struct sk_buff *skb = napi->skb;
3850 skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
3856 EXPORT_SYMBOL(napi_get_frags);
3858 static gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3864 skb->protocol = eth_type_trans(skb, skb->dev);
3866 if (ret == GRO_HELD)
3867 skb_gro_pull(skb, -ETH_HLEN);
3868 else if (netif_receive_skb(skb))
3873 case GRO_MERGED_FREE:
3874 napi_reuse_skb(napi, skb);
3884 static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
3886 struct sk_buff *skb = napi->skb;
3893 skb_reset_mac_header(skb);
3894 skb_gro_reset_offset(skb);
3896 off = skb_gro_offset(skb);
3897 hlen = off + sizeof(*eth);
3898 eth = skb_gro_header_fast(skb, off);
3899 if (skb_gro_header_hard(skb, hlen)) {
3900 eth = skb_gro_header_slow(skb, hlen, off);
3901 if (unlikely(!eth)) {
3902 napi_reuse_skb(napi, skb);
3908 skb_gro_pull(skb, sizeof(*eth));
3911 * This works because the only protocols we care about don't require
3912 * special handling. We'll fix it up properly at the end.
3914 skb->protocol = eth->h_proto;
3920 gro_result_t napi_gro_frags(struct napi_struct *napi)
3922 struct sk_buff *skb = napi_frags_skb(napi);
3927 return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
3929 EXPORT_SYMBOL(napi_gro_frags);
3932 * net_rps_action sends any pending IPI's for rps.
3933 * Note: called with local irq disabled, but exits with local irq enabled.
3935 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
3938 struct softnet_data *remsd = sd->rps_ipi_list;
3941 sd->rps_ipi_list = NULL;
3945 /* Send pending IPI's to kick RPS processing on remote cpus. */
3947 struct softnet_data *next = remsd->rps_ipi_next;
3949 if (cpu_online(remsd->cpu))
3950 __smp_call_function_single(remsd->cpu,
3959 static int process_backlog(struct napi_struct *napi, int quota)
3962 struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
3965 /* Check if we have pending ipi, its better to send them now,
3966 * not waiting net_rx_action() end.
3968 if (sd->rps_ipi_list) {
3969 local_irq_disable();
3970 net_rps_action_and_irq_enable(sd);
3973 napi->weight = weight_p;
3974 local_irq_disable();
3975 while (work < quota) {
3976 struct sk_buff *skb;
3979 while ((skb = __skb_dequeue(&sd->process_queue))) {
3981 __netif_receive_skb(skb);
3982 local_irq_disable();
3983 input_queue_head_incr(sd);
3984 if (++work >= quota) {
3991 qlen = skb_queue_len(&sd->input_pkt_queue);
3993 skb_queue_splice_tail_init(&sd->input_pkt_queue,
3994 &sd->process_queue);
3996 if (qlen < quota - work) {
3998 * Inline a custom version of __napi_complete().
3999 * only current cpu owns and manipulates this napi,
4000 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
4001 * we can use a plain write instead of clear_bit(),
4002 * and we dont need an smp_mb() memory barrier.
4004 list_del(&napi->poll_list);
4007 quota = work + qlen;
4017 * __napi_schedule - schedule for receive
4018 * @n: entry to schedule
4020 * The entry's receive function will be scheduled to run
4022 void __napi_schedule(struct napi_struct *n)
4024 unsigned long flags;
4026 local_irq_save(flags);
4027 ____napi_schedule(&__get_cpu_var(softnet_data), n);
4028 local_irq_restore(flags);
4030 EXPORT_SYMBOL(__napi_schedule);
4032 void __napi_complete(struct napi_struct *n)
4034 BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
4035 BUG_ON(n->gro_list);
4037 list_del(&n->poll_list);
4038 smp_mb__before_clear_bit();
4039 clear_bit(NAPI_STATE_SCHED, &n->state);
4041 EXPORT_SYMBOL(__napi_complete);
4043 void napi_complete(struct napi_struct *n)
4045 unsigned long flags;
4048 * don't let napi dequeue from the cpu poll list
4049 * just in case its running on a different cpu
4051 if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
4054 napi_gro_flush(n, false);
4055 local_irq_save(flags);
4057 local_irq_restore(flags);
4059 EXPORT_SYMBOL(napi_complete);
4061 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
4062 int (*poll)(struct napi_struct *, int), int weight)
4064 INIT_LIST_HEAD(&napi->poll_list);
4065 napi->gro_count = 0;
4066 napi->gro_list = NULL;
4069 napi->weight = weight;
4070 list_add(&napi->dev_list, &dev->napi_list);
4072 #ifdef CONFIG_NETPOLL
4073 spin_lock_init(&napi->poll_lock);
4074 napi->poll_owner = -1;
4076 set_bit(NAPI_STATE_SCHED, &napi->state);
4078 EXPORT_SYMBOL(netif_napi_add);
4080 void netif_napi_del(struct napi_struct *napi)
4082 struct sk_buff *skb, *next;
4084 list_del_init(&napi->dev_list);
4085 napi_free_frags(napi);
4087 for (skb = napi->gro_list; skb; skb = next) {
4093 napi->gro_list = NULL;
4094 napi->gro_count = 0;
4096 EXPORT_SYMBOL(netif_napi_del);
4098 static void net_rx_action(struct softirq_action *h)
4100 struct softnet_data *sd = &__get_cpu_var(softnet_data);
4101 unsigned long time_limit = jiffies + 2;
4102 int budget = netdev_budget;
4105 local_irq_disable();
4107 while (!list_empty(&sd->poll_list)) {
4108 struct napi_struct *n;
4111 /* If softirq window is exhuasted then punt.
4112 * Allow this to run for 2 jiffies since which will allow
4113 * an average latency of 1.5/HZ.
4115 if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
4120 /* Even though interrupts have been re-enabled, this
4121 * access is safe because interrupts can only add new
4122 * entries to the tail of this list, and only ->poll()
4123 * calls can remove this head entry from the list.
4125 n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
4127 have = netpoll_poll_lock(n);
4131 /* This NAPI_STATE_SCHED test is for avoiding a race
4132 * with netpoll's poll_napi(). Only the entity which
4133 * obtains the lock and sees NAPI_STATE_SCHED set will
4134 * actually make the ->poll() call. Therefore we avoid
4135 * accidentally calling ->poll() when NAPI is not scheduled.
4138 if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4139 work = n->poll(n, weight);
4143 WARN_ON_ONCE(work > weight);
4147 local_irq_disable();
4149 /* Drivers must not modify the NAPI state if they
4150 * consume the entire weight. In such cases this code
4151 * still "owns" the NAPI instance and therefore can
4152 * move the instance around on the list at-will.
4154 if (unlikely(work == weight)) {
4155 if (unlikely(napi_disable_pending(n))) {
4158 local_irq_disable();
4161 /* flush too old packets
4162 * If HZ < 1000, flush all packets.
4165 napi_gro_flush(n, HZ >= 1000);
4166 local_irq_disable();
4168 list_move_tail(&n->poll_list, &sd->poll_list);
4172 netpoll_poll_unlock(have);
4175 net_rps_action_and_irq_enable(sd);
4177 #ifdef CONFIG_NET_DMA
4179 * There may not be any more sk_buffs coming right now, so push
4180 * any pending DMA copies to hardware
4182 dma_issue_pending_all();
4189 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4193 struct netdev_upper {
4194 struct net_device *dev;
4196 struct list_head list;
4197 struct rcu_head rcu;
4198 struct list_head search_list;
4201 static void __append_search_uppers(struct list_head *search_list,
4202 struct net_device *dev)
4204 struct netdev_upper *upper;
4206 list_for_each_entry(upper, &dev->upper_dev_list, list) {
4207 /* check if this upper is not already in search list */
4208 if (list_empty(&upper->search_list))
4209 list_add_tail(&upper->search_list, search_list);
4213 static bool __netdev_search_upper_dev(struct net_device *dev,
4214 struct net_device *upper_dev)
4216 LIST_HEAD(search_list);
4217 struct netdev_upper *upper;
4218 struct netdev_upper *tmp;
4221 __append_search_uppers(&search_list, dev);
4222 list_for_each_entry(upper, &search_list, search_list) {
4223 if (upper->dev == upper_dev) {
4227 __append_search_uppers(&search_list, upper->dev);
4229 list_for_each_entry_safe(upper, tmp, &search_list, search_list)
4230 INIT_LIST_HEAD(&upper->search_list);
4234 static struct netdev_upper *__netdev_find_upper(struct net_device *dev,
4235 struct net_device *upper_dev)
4237 struct netdev_upper *upper;
4239 list_for_each_entry(upper, &dev->upper_dev_list, list) {
4240 if (upper->dev == upper_dev)
4247 * netdev_has_upper_dev - Check if device is linked to an upper device
4249 * @upper_dev: upper device to check
4251 * Find out if a device is linked to specified upper device and return true
4252 * in case it is. Note that this checks only immediate upper device,
4253 * not through a complete stack of devices. The caller must hold the RTNL lock.
4255 bool netdev_has_upper_dev(struct net_device *dev,
4256 struct net_device *upper_dev)
4260 return __netdev_find_upper(dev, upper_dev);
4262 EXPORT_SYMBOL(netdev_has_upper_dev);
4265 * netdev_has_any_upper_dev - Check if device is linked to some device
4268 * Find out if a device is linked to an upper device and return true in case
4269 * it is. The caller must hold the RTNL lock.
4271 bool netdev_has_any_upper_dev(struct net_device *dev)
4275 return !list_empty(&dev->upper_dev_list);
4277 EXPORT_SYMBOL(netdev_has_any_upper_dev);
4280 * netdev_master_upper_dev_get - Get master upper device
4283 * Find a master upper device and return pointer to it or NULL in case
4284 * it's not there. The caller must hold the RTNL lock.
4286 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
4288 struct netdev_upper *upper;
4292 if (list_empty(&dev->upper_dev_list))
4295 upper = list_first_entry(&dev->upper_dev_list,
4296 struct netdev_upper, list);
4297 if (likely(upper->master))
4301 EXPORT_SYMBOL(netdev_master_upper_dev_get);
4304 * netdev_master_upper_dev_get_rcu - Get master upper device
4307 * Find a master upper device and return pointer to it or NULL in case
4308 * it's not there. The caller must hold the RCU read lock.
4310 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
4312 struct netdev_upper *upper;
4314 upper = list_first_or_null_rcu(&dev->upper_dev_list,
4315 struct netdev_upper, list);
4316 if (upper && likely(upper->master))
4320 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
4322 static int __netdev_upper_dev_link(struct net_device *dev,
4323 struct net_device *upper_dev, bool master)
4325 struct netdev_upper *upper;
4329 if (dev == upper_dev)
4332 /* To prevent loops, check if dev is not upper device to upper_dev. */
4333 if (__netdev_search_upper_dev(upper_dev, dev))
4336 if (__netdev_find_upper(dev, upper_dev))
4339 if (master && netdev_master_upper_dev_get(dev))
4342 upper = kmalloc(sizeof(*upper), GFP_KERNEL);
4346 upper->dev = upper_dev;
4347 upper->master = master;
4348 INIT_LIST_HEAD(&upper->search_list);
4350 /* Ensure that master upper link is always the first item in list. */
4352 list_add_rcu(&upper->list, &dev->upper_dev_list);
4354 list_add_tail_rcu(&upper->list, &dev->upper_dev_list);
4355 dev_hold(upper_dev);
4361 * netdev_upper_dev_link - Add a link to the upper device
4363 * @upper_dev: new upper device
4365 * Adds a link to device which is upper to this one. The caller must hold
4366 * the RTNL lock. On a failure a negative errno code is returned.
4367 * On success the reference counts are adjusted and the function
4370 int netdev_upper_dev_link(struct net_device *dev,
4371 struct net_device *upper_dev)
4373 return __netdev_upper_dev_link(dev, upper_dev, false);
4375 EXPORT_SYMBOL(netdev_upper_dev_link);
4378 * netdev_master_upper_dev_link - Add a master link to the upper device
4380 * @upper_dev: new upper device
4382 * Adds a link to device which is upper to this one. In this case, only
4383 * one master upper device can be linked, although other non-master devices
4384 * might be linked as well. The caller must hold the RTNL lock.
4385 * On a failure a negative errno code is returned. On success the reference
4386 * counts are adjusted and the function returns zero.
4388 int netdev_master_upper_dev_link(struct net_device *dev,
4389 struct net_device *upper_dev)
4391 return __netdev_upper_dev_link(dev, upper_dev, true);
4393 EXPORT_SYMBOL(netdev_master_upper_dev_link);
4396 * netdev_upper_dev_unlink - Removes a link to upper device
4398 * @upper_dev: new upper device
4400 * Removes a link to device which is upper to this one. The caller must hold
4403 void netdev_upper_dev_unlink(struct net_device *dev,
4404 struct net_device *upper_dev)
4406 struct netdev_upper *upper;
4410 upper = __netdev_find_upper(dev, upper_dev);
4413 list_del_rcu(&upper->list);
4415 kfree_rcu(upper, rcu);
4417 EXPORT_SYMBOL(netdev_upper_dev_unlink);
4419 static void dev_change_rx_flags(struct net_device *dev, int flags)
4421 const struct net_device_ops *ops = dev->netdev_ops;
4423 if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
4424 ops->ndo_change_rx_flags(dev, flags);
4427 static int __dev_set_promiscuity(struct net_device *dev, int inc)
4429 unsigned int old_flags = dev->flags;
4435 dev->flags |= IFF_PROMISC;
4436 dev->promiscuity += inc;
4437 if (dev->promiscuity == 0) {
4440 * If inc causes overflow, untouch promisc and return error.
4443 dev->flags &= ~IFF_PROMISC;
4445 dev->promiscuity -= inc;
4446 pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
4451 if (dev->flags != old_flags) {
4452 pr_info("device %s %s promiscuous mode\n",
4454 dev->flags & IFF_PROMISC ? "entered" : "left");
4455 if (audit_enabled) {
4456 current_uid_gid(&uid, &gid);
4457 audit_log(current->audit_context, GFP_ATOMIC,
4458 AUDIT_ANOM_PROMISCUOUS,
4459 "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
4460 dev->name, (dev->flags & IFF_PROMISC),
4461 (old_flags & IFF_PROMISC),
4462 from_kuid(&init_user_ns, audit_get_loginuid(current)),
4463 from_kuid(&init_user_ns, uid),
4464 from_kgid(&init_user_ns, gid),
4465 audit_get_sessionid(current));
4468 dev_change_rx_flags(dev, IFF_PROMISC);
4474 * dev_set_promiscuity - update promiscuity count on a device
4478 * Add or remove promiscuity from a device. While the count in the device
4479 * remains above zero the interface remains promiscuous. Once it hits zero
4480 * the device reverts back to normal filtering operation. A negative inc
4481 * value is used to drop promiscuity on the device.
4482 * Return 0 if successful or a negative errno code on error.
4484 int dev_set_promiscuity(struct net_device *dev, int inc)
4486 unsigned int old_flags = dev->flags;
4489 err = __dev_set_promiscuity(dev, inc);
4492 if (dev->flags != old_flags)
4493 dev_set_rx_mode(dev);
4496 EXPORT_SYMBOL(dev_set_promiscuity);
4499 * dev_set_allmulti - update allmulti count on a device
4503 * Add or remove reception of all multicast frames to a device. While the
4504 * count in the device remains above zero the interface remains listening
4505 * to all interfaces. Once it hits zero the device reverts back to normal
4506 * filtering operation. A negative @inc value is used to drop the counter
4507 * when releasing a resource needing all multicasts.
4508 * Return 0 if successful or a negative errno code on error.
4511 int dev_set_allmulti(struct net_device *dev, int inc)
4513 unsigned int old_flags = dev->flags;
4517 dev->flags |= IFF_ALLMULTI;
4518 dev->allmulti += inc;
4519 if (dev->allmulti == 0) {
4522 * If inc causes overflow, untouch allmulti and return error.
4525 dev->flags &= ~IFF_ALLMULTI;
4527 dev->allmulti -= inc;
4528 pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
4533 if (dev->flags ^ old_flags) {
4534 dev_change_rx_flags(dev, IFF_ALLMULTI);
4535 dev_set_rx_mode(dev);
4539 EXPORT_SYMBOL(dev_set_allmulti);
4542 * Upload unicast and multicast address lists to device and
4543 * configure RX filtering. When the device doesn't support unicast
4544 * filtering it is put in promiscuous mode while unicast addresses
4547 void __dev_set_rx_mode(struct net_device *dev)
4549 const struct net_device_ops *ops = dev->netdev_ops;
4551 /* dev_open will call this function so the list will stay sane. */
4552 if (!(dev->flags&IFF_UP))
4555 if (!netif_device_present(dev))
4558 if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
4559 /* Unicast addresses changes may only happen under the rtnl,
4560 * therefore calling __dev_set_promiscuity here is safe.
4562 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4563 __dev_set_promiscuity(dev, 1);
4564 dev->uc_promisc = true;
4565 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4566 __dev_set_promiscuity(dev, -1);
4567 dev->uc_promisc = false;
4571 if (ops->ndo_set_rx_mode)
4572 ops->ndo_set_rx_mode(dev);
4575 void dev_set_rx_mode(struct net_device *dev)
4577 netif_addr_lock_bh(dev);
4578 __dev_set_rx_mode(dev);
4579 netif_addr_unlock_bh(dev);
4583 * dev_get_flags - get flags reported to userspace
4586 * Get the combination of flag bits exported through APIs to userspace.
4588 unsigned int dev_get_flags(const struct net_device *dev)
4592 flags = (dev->flags & ~(IFF_PROMISC |
4597 (dev->gflags & (IFF_PROMISC |
4600 if (netif_running(dev)) {
4601 if (netif_oper_up(dev))
4602 flags |= IFF_RUNNING;
4603 if (netif_carrier_ok(dev))
4604 flags |= IFF_LOWER_UP;
4605 if (netif_dormant(dev))
4606 flags |= IFF_DORMANT;
4611 EXPORT_SYMBOL(dev_get_flags);
4613 int __dev_change_flags(struct net_device *dev, unsigned int flags)
4615 unsigned int old_flags = dev->flags;
4621 * Set the flags on our device.
4624 dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
4625 IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
4627 (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
4631 * Load in the correct multicast list now the flags have changed.
4634 if ((old_flags ^ flags) & IFF_MULTICAST)
4635 dev_change_rx_flags(dev, IFF_MULTICAST);
4637 dev_set_rx_mode(dev);
4640 * Have we downed the interface. We handle IFF_UP ourselves
4641 * according to user attempts to set it, rather than blindly
4646 if ((old_flags ^ flags) & IFF_UP) { /* Bit is different ? */
4647 ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
4650 dev_set_rx_mode(dev);
4653 if ((flags ^ dev->gflags) & IFF_PROMISC) {
4654 int inc = (flags & IFF_PROMISC) ? 1 : -1;
4656 dev->gflags ^= IFF_PROMISC;
4657 dev_set_promiscuity(dev, inc);
4660 /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
4661 is important. Some (broken) drivers set IFF_PROMISC, when
4662 IFF_ALLMULTI is requested not asking us and not reporting.
4664 if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
4665 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
4667 dev->gflags ^= IFF_ALLMULTI;
4668 dev_set_allmulti(dev, inc);
4674 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
4676 unsigned int changes = dev->flags ^ old_flags;
4678 if (changes & IFF_UP) {
4679 if (dev->flags & IFF_UP)
4680 call_netdevice_notifiers(NETDEV_UP, dev);
4682 call_netdevice_notifiers(NETDEV_DOWN, dev);
4685 if (dev->flags & IFF_UP &&
4686 (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE)))
4687 call_netdevice_notifiers(NETDEV_CHANGE, dev);
4691 * dev_change_flags - change device settings
4693 * @flags: device state flags
4695 * Change settings on device based state flags. The flags are
4696 * in the userspace exported format.
4698 int dev_change_flags(struct net_device *dev, unsigned int flags)
4701 unsigned int changes, old_flags = dev->flags;
4703 ret = __dev_change_flags(dev, flags);
4707 changes = old_flags ^ dev->flags;
4709 rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
4711 __dev_notify_flags(dev, old_flags);
4714 EXPORT_SYMBOL(dev_change_flags);
4717 * dev_set_mtu - Change maximum transfer unit
4719 * @new_mtu: new transfer unit
4721 * Change the maximum transfer size of the network device.
4723 int dev_set_mtu(struct net_device *dev, int new_mtu)
4725 const struct net_device_ops *ops = dev->netdev_ops;
4728 if (new_mtu == dev->mtu)
4731 /* MTU must be positive. */
4735 if (!netif_device_present(dev))
4739 if (ops->ndo_change_mtu)
4740 err = ops->ndo_change_mtu(dev, new_mtu);
4745 call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
4748 EXPORT_SYMBOL(dev_set_mtu);
4751 * dev_set_group - Change group this device belongs to
4753 * @new_group: group this device should belong to
4755 void dev_set_group(struct net_device *dev, int new_group)
4757 dev->group = new_group;
4759 EXPORT_SYMBOL(dev_set_group);
4762 * dev_set_mac_address - Change Media Access Control Address
4766 * Change the hardware (MAC) address of the device
4768 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
4770 const struct net_device_ops *ops = dev->netdev_ops;
4773 if (!ops->ndo_set_mac_address)
4775 if (sa->sa_family != dev->type)
4777 if (!netif_device_present(dev))
4779 err = ops->ndo_set_mac_address(dev, sa);
4782 dev->addr_assign_type = NET_ADDR_SET;
4783 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4784 add_device_randomness(dev->dev_addr, dev->addr_len);
4787 EXPORT_SYMBOL(dev_set_mac_address);
4790 * dev_change_carrier - Change device carrier
4792 * @new_carrier: new value
4794 * Change device carrier
4796 int dev_change_carrier(struct net_device *dev, bool new_carrier)
4798 const struct net_device_ops *ops = dev->netdev_ops;
4800 if (!ops->ndo_change_carrier)
4802 if (!netif_device_present(dev))
4804 return ops->ndo_change_carrier(dev, new_carrier);
4806 EXPORT_SYMBOL(dev_change_carrier);
4809 * dev_new_index - allocate an ifindex
4810 * @net: the applicable net namespace
4812 * Returns a suitable unique value for a new device interface
4813 * number. The caller must hold the rtnl semaphore or the
4814 * dev_base_lock to be sure it remains unique.
4816 static int dev_new_index(struct net *net)
4818 int ifindex = net->ifindex;
4822 if (!__dev_get_by_index(net, ifindex))
4823 return net->ifindex = ifindex;
4827 /* Delayed registration/unregisteration */
4828 static LIST_HEAD(net_todo_list);
4830 static void net_set_todo(struct net_device *dev)
4832 list_add_tail(&dev->todo_list, &net_todo_list);
4835 static void rollback_registered_many(struct list_head *head)
4837 struct net_device *dev, *tmp;
4839 BUG_ON(dev_boot_phase);
4842 list_for_each_entry_safe(dev, tmp, head, unreg_list) {
4843 /* Some devices call without registering
4844 * for initialization unwind. Remove those
4845 * devices and proceed with the remaining.
4847 if (dev->reg_state == NETREG_UNINITIALIZED) {
4848 pr_debug("unregister_netdevice: device %s/%p never was registered\n",
4852 list_del(&dev->unreg_list);
4855 dev->dismantle = true;
4856 BUG_ON(dev->reg_state != NETREG_REGISTERED);
4859 /* If device is running, close it first. */
4860 dev_close_many(head);
4862 list_for_each_entry(dev, head, unreg_list) {
4863 /* And unlink it from device chain. */
4864 unlist_netdevice(dev);
4866 dev->reg_state = NETREG_UNREGISTERING;
4871 list_for_each_entry(dev, head, unreg_list) {
4872 /* Shutdown queueing discipline. */
4876 /* Notify protocols, that we are about to destroy
4877 this device. They should clean all the things.
4879 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
4881 if (!dev->rtnl_link_ops ||
4882 dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
4883 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
4886 * Flush the unicast and multicast chains
4891 if (dev->netdev_ops->ndo_uninit)
4892 dev->netdev_ops->ndo_uninit(dev);
4894 /* Notifier chain MUST detach us all upper devices. */
4895 WARN_ON(netdev_has_any_upper_dev(dev));
4897 /* Remove entries from kobject tree */
4898 netdev_unregister_kobject(dev);
4900 /* Remove XPS queueing entries */
4901 netif_reset_xps_queues_gt(dev, 0);
4907 list_for_each_entry(dev, head, unreg_list)
4911 static void rollback_registered(struct net_device *dev)
4915 list_add(&dev->unreg_list, &single);
4916 rollback_registered_many(&single);
4920 static netdev_features_t netdev_fix_features(struct net_device *dev,
4921 netdev_features_t features)
4923 /* Fix illegal checksum combinations */
4924 if ((features & NETIF_F_HW_CSUM) &&
4925 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
4926 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
4927 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
4930 /* Fix illegal SG+CSUM combinations. */
4931 if ((features & NETIF_F_SG) &&
4932 !(features & NETIF_F_ALL_CSUM)) {
4934 "Dropping NETIF_F_SG since no checksum feature.\n");
4935 features &= ~NETIF_F_SG;
4938 /* TSO requires that SG is present as well. */
4939 if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
4940 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
4941 features &= ~NETIF_F_ALL_TSO;
4944 /* TSO ECN requires that TSO is present as well. */
4945 if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
4946 features &= ~NETIF_F_TSO_ECN;
4948 /* Software GSO depends on SG. */
4949 if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
4950 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
4951 features &= ~NETIF_F_GSO;
4954 /* UFO needs SG and checksumming */
4955 if (features & NETIF_F_UFO) {
4956 /* maybe split UFO into V4 and V6? */
4957 if (!((features & NETIF_F_GEN_CSUM) ||
4958 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
4959 == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
4961 "Dropping NETIF_F_UFO since no checksum offload features.\n");
4962 features &= ~NETIF_F_UFO;
4965 if (!(features & NETIF_F_SG)) {
4967 "Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
4968 features &= ~NETIF_F_UFO;
4975 int __netdev_update_features(struct net_device *dev)
4977 netdev_features_t features;
4982 features = netdev_get_wanted_features(dev);
4984 if (dev->netdev_ops->ndo_fix_features)
4985 features = dev->netdev_ops->ndo_fix_features(dev, features);
4987 /* driver might be less strict about feature dependencies */
4988 features = netdev_fix_features(dev, features);
4990 if (dev->features == features)
4993 netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
4994 &dev->features, &features);
4996 if (dev->netdev_ops->ndo_set_features)
4997 err = dev->netdev_ops->ndo_set_features(dev, features);
4999 if (unlikely(err < 0)) {
5001 "set_features() failed (%d); wanted %pNF, left %pNF\n",
5002 err, &features, &dev->features);
5007 dev->features = features;
5013 * netdev_update_features - recalculate device features
5014 * @dev: the device to check
5016 * Recalculate dev->features set and send notifications if it
5017 * has changed. Should be called after driver or hardware dependent
5018 * conditions might have changed that influence the features.
5020 void netdev_update_features(struct net_device *dev)
5022 if (__netdev_update_features(dev))
5023 netdev_features_change(dev);
5025 EXPORT_SYMBOL(netdev_update_features);
5028 * netdev_change_features - recalculate device features
5029 * @dev: the device to check
5031 * Recalculate dev->features set and send notifications even
5032 * if they have not changed. Should be called instead of
5033 * netdev_update_features() if also dev->vlan_features might
5034 * have changed to allow the changes to be propagated to stacked
5037 void netdev_change_features(struct net_device *dev)
5039 __netdev_update_features(dev);
5040 netdev_features_change(dev);
5042 EXPORT_SYMBOL(netdev_change_features);
5045 * netif_stacked_transfer_operstate - transfer operstate
5046 * @rootdev: the root or lower level device to transfer state from
5047 * @dev: the device to transfer operstate to
5049 * Transfer operational state from root to device. This is normally
5050 * called when a stacking relationship exists between the root
5051 * device and the device(a leaf device).
5053 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
5054 struct net_device *dev)
5056 if (rootdev->operstate == IF_OPER_DORMANT)
5057 netif_dormant_on(dev);
5059 netif_dormant_off(dev);
5061 if (netif_carrier_ok(rootdev)) {
5062 if (!netif_carrier_ok(dev))
5063 netif_carrier_on(dev);
5065 if (netif_carrier_ok(dev))
5066 netif_carrier_off(dev);
5069 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
5072 static int netif_alloc_rx_queues(struct net_device *dev)
5074 unsigned int i, count = dev->num_rx_queues;
5075 struct netdev_rx_queue *rx;
5079 rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5085 for (i = 0; i < count; i++)
5091 static void netdev_init_one_queue(struct net_device *dev,
5092 struct netdev_queue *queue, void *_unused)
5094 /* Initialize queue lock */
5095 spin_lock_init(&queue->_xmit_lock);
5096 netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
5097 queue->xmit_lock_owner = -1;
5098 netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
5101 dql_init(&queue->dql, HZ);
5105 static int netif_alloc_netdev_queues(struct net_device *dev)
5107 unsigned int count = dev->num_tx_queues;
5108 struct netdev_queue *tx;
5112 tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
5118 netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5119 spin_lock_init(&dev->tx_global_lock);
5125 * register_netdevice - register a network device
5126 * @dev: device to register
5128 * Take a completed network device structure and add it to the kernel
5129 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5130 * chain. 0 is returned on success. A negative errno code is returned
5131 * on a failure to set up the device, or if the name is a duplicate.
5133 * Callers must hold the rtnl semaphore. You may want
5134 * register_netdev() instead of this.
5137 * The locking appears insufficient to guarantee two parallel registers
5138 * will not get the same name.
5141 int register_netdevice(struct net_device *dev)
5144 struct net *net = dev_net(dev);
5146 BUG_ON(dev_boot_phase);
5151 /* When net_device's are persistent, this will be fatal. */
5152 BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5155 spin_lock_init(&dev->addr_list_lock);
5156 netdev_set_addr_lockdep_class(dev);
5160 ret = dev_get_valid_name(net, dev, dev->name);
5164 /* Init, if this function is available */
5165 if (dev->netdev_ops->ndo_init) {
5166 ret = dev->netdev_ops->ndo_init(dev);
5174 if (((dev->hw_features | dev->features) & NETIF_F_HW_VLAN_FILTER) &&
5175 (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
5176 !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
5177 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
5184 dev->ifindex = dev_new_index(net);
5185 else if (__dev_get_by_index(net, dev->ifindex))
5188 if (dev->iflink == -1)
5189 dev->iflink = dev->ifindex;
5191 /* Transfer changeable features to wanted_features and enable
5192 * software offloads (GSO and GRO).
5194 dev->hw_features |= NETIF_F_SOFT_FEATURES;
5195 dev->features |= NETIF_F_SOFT_FEATURES;
5196 dev->wanted_features = dev->features & dev->hw_features;
5198 /* Turn on no cache copy if HW is doing checksum */
5199 if (!(dev->flags & IFF_LOOPBACK)) {
5200 dev->hw_features |= NETIF_F_NOCACHE_COPY;
5201 if (dev->features & NETIF_F_ALL_CSUM) {
5202 dev->wanted_features |= NETIF_F_NOCACHE_COPY;
5203 dev->features |= NETIF_F_NOCACHE_COPY;
5207 /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5209 dev->vlan_features |= NETIF_F_HIGHDMA;
5211 ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5212 ret = notifier_to_errno(ret);
5216 ret = netdev_register_kobject(dev);
5219 dev->reg_state = NETREG_REGISTERED;
5221 __netdev_update_features(dev);
5224 * Default initial state at registry is that the
5225 * device is present.
5228 set_bit(__LINK_STATE_PRESENT, &dev->state);
5230 linkwatch_init_dev(dev);
5232 dev_init_scheduler(dev);
5234 list_netdevice(dev);
5235 add_device_randomness(dev->dev_addr, dev->addr_len);
5237 /* If the device has permanent device address, driver should
5238 * set dev_addr and also addr_assign_type should be set to
5239 * NET_ADDR_PERM (default value).
5241 if (dev->addr_assign_type == NET_ADDR_PERM)
5242 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
5244 /* Notify protocols, that a new device appeared. */
5245 ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5246 ret = notifier_to_errno(ret);
5248 rollback_registered(dev);
5249 dev->reg_state = NETREG_UNREGISTERED;
5252 * Prevent userspace races by waiting until the network
5253 * device is fully setup before sending notifications.
5255 if (!dev->rtnl_link_ops ||
5256 dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5257 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5263 if (dev->netdev_ops->ndo_uninit)
5264 dev->netdev_ops->ndo_uninit(dev);
5267 EXPORT_SYMBOL(register_netdevice);
5270 * init_dummy_netdev - init a dummy network device for NAPI
5271 * @dev: device to init
5273 * This takes a network device structure and initialize the minimum
5274 * amount of fields so it can be used to schedule NAPI polls without
5275 * registering a full blown interface. This is to be used by drivers
5276 * that need to tie several hardware interfaces to a single NAPI
5277 * poll scheduler due to HW limitations.
5279 int init_dummy_netdev(struct net_device *dev)
5281 /* Clear everything. Note we don't initialize spinlocks
5282 * are they aren't supposed to be taken by any of the
5283 * NAPI code and this dummy netdev is supposed to be
5284 * only ever used for NAPI polls
5286 memset(dev, 0, sizeof(struct net_device));
5288 /* make sure we BUG if trying to hit standard
5289 * register/unregister code path
5291 dev->reg_state = NETREG_DUMMY;
5293 /* NAPI wants this */
5294 INIT_LIST_HEAD(&dev->napi_list);
5296 /* a dummy interface is started by default */
5297 set_bit(__LINK_STATE_PRESENT, &dev->state);
5298 set_bit(__LINK_STATE_START, &dev->state);
5300 /* Note : We dont allocate pcpu_refcnt for dummy devices,
5301 * because users of this 'device' dont need to change
5307 EXPORT_SYMBOL_GPL(init_dummy_netdev);
5311 * register_netdev - register a network device
5312 * @dev: device to register
5314 * Take a completed network device structure and add it to the kernel
5315 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5316 * chain. 0 is returned on success. A negative errno code is returned
5317 * on a failure to set up the device, or if the name is a duplicate.
5319 * This is a wrapper around register_netdevice that takes the rtnl semaphore
5320 * and expands the device name if you passed a format string to
5323 int register_netdev(struct net_device *dev)
5328 err = register_netdevice(dev);
5332 EXPORT_SYMBOL(register_netdev);
5334 int netdev_refcnt_read(const struct net_device *dev)
5338 for_each_possible_cpu(i)
5339 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
5342 EXPORT_SYMBOL(netdev_refcnt_read);
5345 * netdev_wait_allrefs - wait until all references are gone.
5346 * @dev: target net_device
5348 * This is called when unregistering network devices.
5350 * Any protocol or device that holds a reference should register
5351 * for netdevice notification, and cleanup and put back the
5352 * reference if they receive an UNREGISTER event.
5353 * We can get stuck here if buggy protocols don't correctly
5356 static void netdev_wait_allrefs(struct net_device *dev)
5358 unsigned long rebroadcast_time, warning_time;
5361 linkwatch_forget_dev(dev);
5363 rebroadcast_time = warning_time = jiffies;
5364 refcnt = netdev_refcnt_read(dev);
5366 while (refcnt != 0) {
5367 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5370 /* Rebroadcast unregister notification */
5371 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5377 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5378 if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
5380 /* We must not have linkwatch events
5381 * pending on unregister. If this
5382 * happens, we simply run the queue
5383 * unscheduled, resulting in a noop
5386 linkwatch_run_queue();
5391 rebroadcast_time = jiffies;
5396 refcnt = netdev_refcnt_read(dev);
5398 if (time_after(jiffies, warning_time + 10 * HZ)) {
5399 pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
5401 warning_time = jiffies;
5410 * register_netdevice(x1);
5411 * register_netdevice(x2);
5413 * unregister_netdevice(y1);
5414 * unregister_netdevice(y2);
5420 * We are invoked by rtnl_unlock().
5421 * This allows us to deal with problems:
5422 * 1) We can delete sysfs objects which invoke hotplug
5423 * without deadlocking with linkwatch via keventd.
5424 * 2) Since we run with the RTNL semaphore not held, we can sleep
5425 * safely in order to wait for the netdev refcnt to drop to zero.
5427 * We must not return until all unregister events added during
5428 * the interval the lock was held have been completed.
5430 void netdev_run_todo(void)
5432 struct list_head list;
5434 /* Snapshot list, allow later requests */
5435 list_replace_init(&net_todo_list, &list);
5440 /* Wait for rcu callbacks to finish before next phase */
5441 if (!list_empty(&list))
5444 while (!list_empty(&list)) {
5445 struct net_device *dev
5446 = list_first_entry(&list, struct net_device, todo_list);
5447 list_del(&dev->todo_list);
5450 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5453 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5454 pr_err("network todo '%s' but state %d\n",
5455 dev->name, dev->reg_state);
5460 dev->reg_state = NETREG_UNREGISTERED;
5462 on_each_cpu(flush_backlog, dev, 1);
5464 netdev_wait_allrefs(dev);
5467 BUG_ON(netdev_refcnt_read(dev));
5468 WARN_ON(rcu_access_pointer(dev->ip_ptr));
5469 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
5470 WARN_ON(dev->dn_ptr);
5472 if (dev->destructor)
5473 dev->destructor(dev);
5475 /* Free network device */
5476 kobject_put(&dev->dev.kobj);
5480 /* Convert net_device_stats to rtnl_link_stats64. They have the same
5481 * fields in the same order, with only the type differing.
5483 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
5484 const struct net_device_stats *netdev_stats)
5486 #if BITS_PER_LONG == 64
5487 BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
5488 memcpy(stats64, netdev_stats, sizeof(*stats64));
5490 size_t i, n = sizeof(*stats64) / sizeof(u64);
5491 const unsigned long *src = (const unsigned long *)netdev_stats;
5492 u64 *dst = (u64 *)stats64;
5494 BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
5495 sizeof(*stats64) / sizeof(u64));
5496 for (i = 0; i < n; i++)
5500 EXPORT_SYMBOL(netdev_stats_to_stats64);
5503 * dev_get_stats - get network device statistics
5504 * @dev: device to get statistics from
5505 * @storage: place to store stats
5507 * Get network statistics from device. Return @storage.
5508 * The device driver may provide its own method by setting
5509 * dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
5510 * otherwise the internal statistics structure is used.
5512 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
5513 struct rtnl_link_stats64 *storage)
5515 const struct net_device_ops *ops = dev->netdev_ops;
5517 if (ops->ndo_get_stats64) {
5518 memset(storage, 0, sizeof(*storage));
5519 ops->ndo_get_stats64(dev, storage);
5520 } else if (ops->ndo_get_stats) {
5521 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
5523 netdev_stats_to_stats64(storage, &dev->stats);
5525 storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
5528 EXPORT_SYMBOL(dev_get_stats);
5530 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
5532 struct netdev_queue *queue = dev_ingress_queue(dev);
5534 #ifdef CONFIG_NET_CLS_ACT
5537 queue = kzalloc(sizeof(*queue), GFP_KERNEL);
5540 netdev_init_one_queue(dev, queue, NULL);
5541 queue->qdisc = &noop_qdisc;
5542 queue->qdisc_sleeping = &noop_qdisc;
5543 rcu_assign_pointer(dev->ingress_queue, queue);
5548 static const struct ethtool_ops default_ethtool_ops;
5550 void netdev_set_default_ethtool_ops(struct net_device *dev,
5551 const struct ethtool_ops *ops)
5553 if (dev->ethtool_ops == &default_ethtool_ops)
5554 dev->ethtool_ops = ops;
5556 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
5559 * alloc_netdev_mqs - allocate network device
5560 * @sizeof_priv: size of private data to allocate space for
5561 * @name: device name format string
5562 * @setup: callback to initialize device
5563 * @txqs: the number of TX subqueues to allocate
5564 * @rxqs: the number of RX subqueues to allocate
5566 * Allocates a struct net_device with private data area for driver use
5567 * and performs basic initialization. Also allocates subquue structs
5568 * for each queue on the device.
5570 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
5571 void (*setup)(struct net_device *),
5572 unsigned int txqs, unsigned int rxqs)
5574 struct net_device *dev;
5576 struct net_device *p;
5578 BUG_ON(strlen(name) >= sizeof(dev->name));
5581 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
5587 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
5592 alloc_size = sizeof(struct net_device);
5594 /* ensure 32-byte alignment of private area */
5595 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5596 alloc_size += sizeof_priv;
5598 /* ensure 32-byte alignment of whole construct */
5599 alloc_size += NETDEV_ALIGN - 1;
5601 p = kzalloc(alloc_size, GFP_KERNEL);
5605 dev = PTR_ALIGN(p, NETDEV_ALIGN);
5606 dev->padded = (char *)dev - (char *)p;
5608 dev->pcpu_refcnt = alloc_percpu(int);
5609 if (!dev->pcpu_refcnt)
5612 if (dev_addr_init(dev))
5618 dev_net_set(dev, &init_net);
5620 dev->gso_max_size = GSO_MAX_SIZE;
5621 dev->gso_max_segs = GSO_MAX_SEGS;
5623 INIT_LIST_HEAD(&dev->napi_list);
5624 INIT_LIST_HEAD(&dev->unreg_list);
5625 INIT_LIST_HEAD(&dev->link_watch_list);
5626 INIT_LIST_HEAD(&dev->upper_dev_list);
5627 dev->priv_flags = IFF_XMIT_DST_RELEASE;
5630 dev->num_tx_queues = txqs;
5631 dev->real_num_tx_queues = txqs;
5632 if (netif_alloc_netdev_queues(dev))
5636 dev->num_rx_queues = rxqs;
5637 dev->real_num_rx_queues = rxqs;
5638 if (netif_alloc_rx_queues(dev))
5642 strcpy(dev->name, name);
5643 dev->group = INIT_NETDEV_GROUP;
5644 if (!dev->ethtool_ops)
5645 dev->ethtool_ops = &default_ethtool_ops;
5653 free_percpu(dev->pcpu_refcnt);
5663 EXPORT_SYMBOL(alloc_netdev_mqs);
5666 * free_netdev - free network device
5669 * This function does the last stage of destroying an allocated device
5670 * interface. The reference to the device object is released.
5671 * If this is the last reference then it will be freed.
5673 void free_netdev(struct net_device *dev)
5675 struct napi_struct *p, *n;
5677 release_net(dev_net(dev));
5684 kfree(rcu_dereference_protected(dev->ingress_queue, 1));
5686 /* Flush device addresses */
5687 dev_addr_flush(dev);
5689 list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
5692 free_percpu(dev->pcpu_refcnt);
5693 dev->pcpu_refcnt = NULL;
5695 /* Compatibility with error handling in drivers */
5696 if (dev->reg_state == NETREG_UNINITIALIZED) {
5697 kfree((char *)dev - dev->padded);
5701 BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
5702 dev->reg_state = NETREG_RELEASED;
5704 /* will free via device release */
5705 put_device(&dev->dev);
5707 EXPORT_SYMBOL(free_netdev);
5710 * synchronize_net - Synchronize with packet receive processing
5712 * Wait for packets currently being received to be done.
5713 * Does not block later packets from starting.
5715 void synchronize_net(void)
5718 if (rtnl_is_locked())
5719 synchronize_rcu_expedited();
5723 EXPORT_SYMBOL(synchronize_net);
5726 * unregister_netdevice_queue - remove device from the kernel
5730 * This function shuts down a device interface and removes it
5731 * from the kernel tables.
5732 * If head not NULL, device is queued to be unregistered later.
5734 * Callers must hold the rtnl semaphore. You may want
5735 * unregister_netdev() instead of this.
5738 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
5743 list_move_tail(&dev->unreg_list, head);
5745 rollback_registered(dev);
5746 /* Finish processing unregister after unlock */
5750 EXPORT_SYMBOL(unregister_netdevice_queue);
5753 * unregister_netdevice_many - unregister many devices
5754 * @head: list of devices
5756 void unregister_netdevice_many(struct list_head *head)
5758 struct net_device *dev;
5760 if (!list_empty(head)) {
5761 rollback_registered_many(head);
5762 list_for_each_entry(dev, head, unreg_list)
5766 EXPORT_SYMBOL(unregister_netdevice_many);
5769 * unregister_netdev - remove device from the kernel
5772 * This function shuts down a device interface and removes it
5773 * from the kernel tables.
5775 * This is just a wrapper for unregister_netdevice that takes
5776 * the rtnl semaphore. In general you want to use this and not
5777 * unregister_netdevice.
5779 void unregister_netdev(struct net_device *dev)
5782 unregister_netdevice(dev);
5785 EXPORT_SYMBOL(unregister_netdev);
5788 * dev_change_net_namespace - move device to different nethost namespace
5790 * @net: network namespace
5791 * @pat: If not NULL name pattern to try if the current device name
5792 * is already taken in the destination network namespace.
5794 * This function shuts down a device interface and moves it
5795 * to a new network namespace. On success 0 is returned, on
5796 * a failure a netagive errno code is returned.
5798 * Callers must hold the rtnl semaphore.
5801 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
5807 /* Don't allow namespace local devices to be moved. */
5809 if (dev->features & NETIF_F_NETNS_LOCAL)
5812 /* Ensure the device has been registrered */
5813 if (dev->reg_state != NETREG_REGISTERED)
5816 /* Get out if there is nothing todo */
5818 if (net_eq(dev_net(dev), net))
5821 /* Pick the destination device name, and ensure
5822 * we can use it in the destination network namespace.
5825 if (__dev_get_by_name(net, dev->name)) {
5826 /* We get here if we can't use the current device name */
5829 if (dev_get_valid_name(net, dev, pat) < 0)
5834 * And now a mini version of register_netdevice unregister_netdevice.
5837 /* If device is running close it first. */
5840 /* And unlink it from device chain */
5842 unlist_netdevice(dev);
5846 /* Shutdown queueing discipline. */
5849 /* Notify protocols, that we are about to destroy
5850 this device. They should clean all the things.
5852 Note that dev->reg_state stays at NETREG_REGISTERED.
5853 This is wanted because this way 8021q and macvlan know
5854 the device is just moving and can keep their slaves up.
5856 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5858 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5859 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
5862 * Flush the unicast and multicast chains
5867 /* Send a netdev-removed uevent to the old namespace */
5868 kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
5870 /* Actually switch the network namespace */
5871 dev_net_set(dev, net);
5873 /* If there is an ifindex conflict assign a new one */
5874 if (__dev_get_by_index(net, dev->ifindex)) {
5875 int iflink = (dev->iflink == dev->ifindex);
5876 dev->ifindex = dev_new_index(net);
5878 dev->iflink = dev->ifindex;
5881 /* Send a netdev-add uevent to the new namespace */
5882 kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
5884 /* Fixup kobjects */
5885 err = device_rename(&dev->dev, dev->name);
5888 /* Add the device back in the hashes */
5889 list_netdevice(dev);
5891 /* Notify protocols, that a new device appeared. */
5892 call_netdevice_notifiers(NETDEV_REGISTER, dev);
5895 * Prevent userspace races by waiting until the network
5896 * device is fully setup before sending notifications.
5898 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5905 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
5907 static int dev_cpu_callback(struct notifier_block *nfb,
5908 unsigned long action,
5911 struct sk_buff **list_skb;
5912 struct sk_buff *skb;
5913 unsigned int cpu, oldcpu = (unsigned long)ocpu;
5914 struct softnet_data *sd, *oldsd;
5916 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
5919 local_irq_disable();
5920 cpu = smp_processor_id();
5921 sd = &per_cpu(softnet_data, cpu);
5922 oldsd = &per_cpu(softnet_data, oldcpu);
5924 /* Find end of our completion_queue. */
5925 list_skb = &sd->completion_queue;
5927 list_skb = &(*list_skb)->next;
5928 /* Append completion queue from offline CPU. */
5929 *list_skb = oldsd->completion_queue;
5930 oldsd->completion_queue = NULL;
5932 /* Append output queue from offline CPU. */
5933 if (oldsd->output_queue) {
5934 *sd->output_queue_tailp = oldsd->output_queue;
5935 sd->output_queue_tailp = oldsd->output_queue_tailp;
5936 oldsd->output_queue = NULL;
5937 oldsd->output_queue_tailp = &oldsd->output_queue;
5939 /* Append NAPI poll list from offline CPU. */
5940 if (!list_empty(&oldsd->poll_list)) {
5941 list_splice_init(&oldsd->poll_list, &sd->poll_list);
5942 raise_softirq_irqoff(NET_RX_SOFTIRQ);
5945 raise_softirq_irqoff(NET_TX_SOFTIRQ);
5948 /* Process offline CPU's input_pkt_queue */
5949 while ((skb = __skb_dequeue(&oldsd->process_queue))) {
5951 input_queue_head_incr(oldsd);
5953 while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
5955 input_queue_head_incr(oldsd);
5963 * netdev_increment_features - increment feature set by one
5964 * @all: current feature set
5965 * @one: new feature set
5966 * @mask: mask feature set
5968 * Computes a new feature set after adding a device with feature set
5969 * @one to the master device with current feature set @all. Will not
5970 * enable anything that is off in @mask. Returns the new feature set.
5972 netdev_features_t netdev_increment_features(netdev_features_t all,
5973 netdev_features_t one, netdev_features_t mask)
5975 if (mask & NETIF_F_GEN_CSUM)
5976 mask |= NETIF_F_ALL_CSUM;
5977 mask |= NETIF_F_VLAN_CHALLENGED;
5979 all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
5980 all &= one | ~NETIF_F_ALL_FOR_ALL;
5982 /* If one device supports hw checksumming, set for all. */
5983 if (all & NETIF_F_GEN_CSUM)
5984 all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
5988 EXPORT_SYMBOL(netdev_increment_features);
5990 static struct hlist_head *netdev_create_hash(void)
5993 struct hlist_head *hash;
5995 hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
5997 for (i = 0; i < NETDEV_HASHENTRIES; i++)
5998 INIT_HLIST_HEAD(&hash[i]);
6003 /* Initialize per network namespace state */
6004 static int __net_init netdev_init(struct net *net)
6006 if (net != &init_net)
6007 INIT_LIST_HEAD(&net->dev_base_head);
6009 net->dev_name_head = netdev_create_hash();
6010 if (net->dev_name_head == NULL)
6013 net->dev_index_head = netdev_create_hash();
6014 if (net->dev_index_head == NULL)
6020 kfree(net->dev_name_head);
6026 * netdev_drivername - network driver for the device
6027 * @dev: network device
6029 * Determine network driver for device.
6031 const char *netdev_drivername(const struct net_device *dev)
6033 const struct device_driver *driver;
6034 const struct device *parent;
6035 const char *empty = "";
6037 parent = dev->dev.parent;
6041 driver = parent->driver;
6042 if (driver && driver->name)
6043 return driver->name;
6047 static int __netdev_printk(const char *level, const struct net_device *dev,
6048 struct va_format *vaf)
6052 if (dev && dev->dev.parent) {
6053 r = dev_printk_emit(level[1] - '0',
6056 dev_driver_string(dev->dev.parent),
6057 dev_name(dev->dev.parent),
6058 netdev_name(dev), vaf);
6060 r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6062 r = printk("%s(NULL net_device): %pV", level, vaf);
6068 int netdev_printk(const char *level, const struct net_device *dev,
6069 const char *format, ...)
6071 struct va_format vaf;
6075 va_start(args, format);
6080 r = __netdev_printk(level, dev, &vaf);
6086 EXPORT_SYMBOL(netdev_printk);
6088 #define define_netdev_printk_level(func, level) \
6089 int func(const struct net_device *dev, const char *fmt, ...) \
6092 struct va_format vaf; \
6095 va_start(args, fmt); \
6100 r = __netdev_printk(level, dev, &vaf); \
6106 EXPORT_SYMBOL(func);
6108 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
6109 define_netdev_printk_level(netdev_alert, KERN_ALERT);
6110 define_netdev_printk_level(netdev_crit, KERN_CRIT);
6111 define_netdev_printk_level(netdev_err, KERN_ERR);
6112 define_netdev_printk_level(netdev_warn, KERN_WARNING);
6113 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
6114 define_netdev_printk_level(netdev_info, KERN_INFO);
6116 static void __net_exit netdev_exit(struct net *net)
6118 kfree(net->dev_name_head);
6119 kfree(net->dev_index_head);
6122 static struct pernet_operations __net_initdata netdev_net_ops = {
6123 .init = netdev_init,
6124 .exit = netdev_exit,
6127 static void __net_exit default_device_exit(struct net *net)
6129 struct net_device *dev, *aux;
6131 * Push all migratable network devices back to the
6132 * initial network namespace
6135 for_each_netdev_safe(net, dev, aux) {
6137 char fb_name[IFNAMSIZ];
6139 /* Ignore unmoveable devices (i.e. loopback) */
6140 if (dev->features & NETIF_F_NETNS_LOCAL)
6143 /* Leave virtual devices for the generic cleanup */
6144 if (dev->rtnl_link_ops)
6147 /* Push remaining network devices to init_net */
6148 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
6149 err = dev_change_net_namespace(dev, &init_net, fb_name);
6151 pr_emerg("%s: failed to move %s to init_net: %d\n",
6152 __func__, dev->name, err);
6159 static void __net_exit default_device_exit_batch(struct list_head *net_list)
6161 /* At exit all network devices most be removed from a network
6162 * namespace. Do this in the reverse order of registration.
6163 * Do this across as many network namespaces as possible to
6164 * improve batching efficiency.
6166 struct net_device *dev;
6168 LIST_HEAD(dev_kill_list);
6171 list_for_each_entry(net, net_list, exit_list) {
6172 for_each_netdev_reverse(net, dev) {
6173 if (dev->rtnl_link_ops)
6174 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
6176 unregister_netdevice_queue(dev, &dev_kill_list);
6179 unregister_netdevice_many(&dev_kill_list);
6180 list_del(&dev_kill_list);
6184 static struct pernet_operations __net_initdata default_device_ops = {
6185 .exit = default_device_exit,
6186 .exit_batch = default_device_exit_batch,
6190 * Initialize the DEV module. At boot time this walks the device list and
6191 * unhooks any devices that fail to initialise (normally hardware not
6192 * present) and leaves us with a valid list of present and active devices.
6197 * This is called single threaded during boot, so no need
6198 * to take the rtnl semaphore.
6200 static int __init net_dev_init(void)
6202 int i, rc = -ENOMEM;
6204 BUG_ON(!dev_boot_phase);
6206 if (dev_proc_init())
6209 if (netdev_kobject_init())
6212 INIT_LIST_HEAD(&ptype_all);
6213 for (i = 0; i < PTYPE_HASH_SIZE; i++)
6214 INIT_LIST_HEAD(&ptype_base[i]);
6216 INIT_LIST_HEAD(&offload_base);
6218 if (register_pernet_subsys(&netdev_net_ops))
6222 * Initialise the packet receive queues.
6225 for_each_possible_cpu(i) {
6226 struct softnet_data *sd = &per_cpu(softnet_data, i);
6228 memset(sd, 0, sizeof(*sd));
6229 skb_queue_head_init(&sd->input_pkt_queue);
6230 skb_queue_head_init(&sd->process_queue);
6231 sd->completion_queue = NULL;
6232 INIT_LIST_HEAD(&sd->poll_list);
6233 sd->output_queue = NULL;
6234 sd->output_queue_tailp = &sd->output_queue;
6236 sd->csd.func = rps_trigger_softirq;
6242 sd->backlog.poll = process_backlog;
6243 sd->backlog.weight = weight_p;
6244 sd->backlog.gro_list = NULL;
6245 sd->backlog.gro_count = 0;
6250 /* The loopback device is special if any other network devices
6251 * is present in a network namespace the loopback device must
6252 * be present. Since we now dynamically allocate and free the
6253 * loopback device ensure this invariant is maintained by
6254 * keeping the loopback device as the first device on the
6255 * list of network devices. Ensuring the loopback devices
6256 * is the first device that appears and the last network device
6259 if (register_pernet_device(&loopback_net_ops))
6262 if (register_pernet_device(&default_device_ops))
6265 open_softirq(NET_TX_SOFTIRQ, net_tx_action);
6266 open_softirq(NET_RX_SOFTIRQ, net_rx_action);
6268 hotcpu_notifier(dev_cpu_callback, 0);
6275 subsys_initcall(net_dev_init);