net/core/dev.c

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