Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

Linux/net/core/dev.c

  1 /*
  2  *      NET3    Protocol independent device support routines.
  3  *
  4  *              This program is free software; you can redistribute it and/or
  5  *              modify it under the terms of the GNU General Public License
  6  *              as published by the Free Software Foundation; either version
  7  *              2 of the License, or (at your option) any later version.
  8  *
  9  *      Derived from the non IP parts of dev.c 1.0.19
 10  *              Authors:        Ross Biro
 11  *                              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 12  *                              Mark Evans, <evansmp@uhura.aston.ac.uk>
 13  *
 14  *      Additional Authors:
 15  *              Florian la Roche <rzsfl@rz.uni-sb.de>
 16  *              Alan Cox <gw4pts@gw4pts.ampr.org>
 17  *              David Hinds <dahinds@users.sourceforge.net>
 18  *              Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
 19  *              Adam Sulmicki <adam@cfar.umd.edu>
 20  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
 21  *
 22  *      Changes:
 23  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
 24  *                                      to 2 if register_netdev gets called
 25  *                                      before net_dev_init & also removed a
 26  *                                      few lines of code in the process.
 27  *              Alan Cox        :       device private ioctl copies fields back.
 28  *              Alan Cox        :       Transmit queue code does relevant
 29  *                                      stunts to keep the queue safe.
 30  *              Alan Cox        :       Fixed double lock.
 31  *              Alan Cox        :       Fixed promisc NULL pointer trap
 32  *              ????????        :       Support the full private ioctl range
 33  *              Alan Cox        :       Moved ioctl permission check into
 34  *                                      drivers
 35  *              Tim Kordas      :       SIOCADDMULTI/SIOCDELMULTI
 36  *              Alan Cox        :       100 backlog just doesn't cut it when
 37  *                                      you start doing multicast video 8)
 38  *              Alan Cox        :       Rewrote net_bh and list manager.
 39  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
 40  *              Alan Cox        :       Took out transmit every packet pass
 41  *                                      Saved a few bytes in the ioctl handler
 42  *              Alan Cox        :       Network driver sets packet type before
 43  *                                      calling netif_rx. Saves a function
 44  *                                      call a packet.
 45  *              Alan Cox        :       Hashed net_bh()
 46  *              Richard Kooijman:       Timestamp fixes.
 47  *              Alan Cox        :       Wrong field in SIOCGIFDSTADDR
 48  *              Alan Cox        :       Device lock protection.
 49  *              Alan Cox        :       Fixed nasty side effect of device close
 50  *                                      changes.
 51  *              Rudi Cilibrasi  :       Pass the right thing to
 52  *                                      set_mac_address()
 53  *              Dave Miller     :       32bit quantity for the device lock to
 54  *                                      make it work out on a Sparc.
 55  *              Bjorn Ekwall    :       Added KERNELD hack.
 56  *              Alan Cox        :       Cleaned up the backlog initialise.
 57  *              Craig Metz      :       SIOCGIFCONF fix if space for under
 58  *                                      1 device.
 59  *          Thomas Bogendoerfer :       Return ENODEV for dev_open, if there
 60  *                                      is no device open function.
 61  *              Andi Kleen      :       Fix error reporting for SIOCGIFCONF
 62  *          Michael Chastain    :       Fix signed/unsigned for SIOCGIFCONF
 63  *              Cyrus Durgin    :       Cleaned for KMOD
 64  *              Adam Sulmicki   :       Bug Fix : Network Device Unload
 65  *                                      A network device unload needs to purge
 66  *                                      the backlog queue.
 67  *      Paul Rusty Russell      :       SIOCSIFNAME
 68  *              Pekka Riikonen  :       Netdev boot-time settings code
 69  *              Andrew Morton   :       Make unregister_netdevice wait
 70  *                                      indefinitely on dev->refcnt
 71  *              J Hadi Salim    :       - Backlog queue sampling
 72  *                                      - netif_rx() feedback
 73  */
 74 
 75 #include <asm/uaccess.h>
 76 #include <linux/bitops.h>
 77 #include <linux/capability.h>
 78 #include <linux/cpu.h>
 79 #include <linux/types.h>
 80 #include <linux/kernel.h>
 81 #include <linux/hash.h>
 82 #include <linux/slab.h>
 83 #include <linux/sched.h>
 84 #include <linux/mutex.h>
 85 #include <linux/string.h>
 86 #include <linux/mm.h>
 87 #include <linux/socket.h>
 88 #include <linux/sockios.h>
 89 #include <linux/errno.h>
 90 #include <linux/interrupt.h>
 91 #include <linux/if_ether.h>
 92 #include <linux/netdevice.h>
 93 #include <linux/etherdevice.h>
 94 #include <linux/ethtool.h>
 95 #include <linux/notifier.h>
 96 #include <linux/skbuff.h>
 97 #include <net/net_namespace.h>
 98 #include <net/sock.h>
 99 #include <linux/rtnetlink.h>
100 #include <linux/stat.h>
101 #include <net/dst.h>
102 #include <net/pkt_sched.h>
103 #include <net/checksum.h>
104 #include <net/xfrm.h>
105 #include <linux/highmem.h>
106 #include <linux/init.h>
107 #include <linux/module.h>
108 #include <linux/netpoll.h>
109 #include <linux/rcupdate.h>
110 #include <linux/delay.h>
111 #include <net/iw_handler.h>
112 #include <asm/current.h>
113 #include <linux/audit.h>
114 #include <linux/dmaengine.h>
115 #include <linux/err.h>
116 #include <linux/ctype.h>
117 #include <linux/if_arp.h>
118 #include <linux/if_vlan.h>
119 #include <linux/ip.h>
120 #include <net/ip.h>
121 #include <linux/ipv6.h>
122 #include <linux/in.h>
123 #include <linux/jhash.h>
124 #include <linux/random.h>
125 #include <trace/events/napi.h>
126 #include <trace/events/net.h>
127 #include <trace/events/skb.h>
128 #include <linux/pci.h>
129 #include <linux/inetdevice.h>
130 #include <linux/cpu_rmap.h>
131 #include <linux/static_key.h>
132 #include <linux/hashtable.h>
133 #include <linux/vmalloc.h>
134 #include <linux/if_macvlan.h>
135 #include <linux/errqueue.h>
136 
137 #include "net-sysfs.h"
138 
139 /* Instead of increasing this, you should create a hash table. */
140 #define MAX_GRO_SKBS 8
141 
142 /* This should be increased if a protocol with a bigger head is added. */
143 #define GRO_MAX_HEAD (MAX_HEADER + 128)
144 
145 static DEFINE_SPINLOCK(ptype_lock);
146 static DEFINE_SPINLOCK(offload_lock);
147 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
148 struct list_head ptype_all __read_mostly;       /* Taps */
149 static struct list_head offload_base __read_mostly;
150 
151 static int netif_rx_internal(struct sk_buff *skb);
152 static int call_netdevice_notifiers_info(unsigned long val,
153                                          struct net_device *dev,
154                                          struct netdev_notifier_info *info);
155 
156 /*
157  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
158  * semaphore.
159  *
160  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
161  *
162  * Writers must hold the rtnl semaphore while they loop through the
163  * dev_base_head list, and hold dev_base_lock for writing when they do the
164  * actual updates.  This allows pure readers to access the list even
165  * while a writer is preparing to update it.
166  *
167  * To put it another way, dev_base_lock is held for writing only to
168  * protect against pure readers; the rtnl semaphore provides the
169  * protection against other writers.
170  *
171  * See, for example usages, register_netdevice() and
172  * unregister_netdevice(), which must be called with the rtnl
173  * semaphore held.
174  */
175 DEFINE_RWLOCK(dev_base_lock);
176 EXPORT_SYMBOL(dev_base_lock);
177 
178 /* protects napi_hash addition/deletion and napi_gen_id */
179 static DEFINE_SPINLOCK(napi_hash_lock);
180 
181 static unsigned int napi_gen_id;
182 static DEFINE_HASHTABLE(napi_hash, 8);
183 
184 static seqcount_t devnet_rename_seq;
185 
186 static inline void dev_base_seq_inc(struct net *net)
187 {
188         while (++net->dev_base_seq == 0);
189 }
190 
191 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
192 {
193         unsigned int hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
194 
195         return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
196 }
197 
198 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
199 {
200         return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
201 }
202 
203 static inline void rps_lock(struct softnet_data *sd)
204 {
205 #ifdef CONFIG_RPS
206         spin_lock(&sd->input_pkt_queue.lock);
207 #endif
208 }
209 
210 static inline void rps_unlock(struct softnet_data *sd)
211 {
212 #ifdef CONFIG_RPS
213         spin_unlock(&sd->input_pkt_queue.lock);
214 #endif
215 }
216 
217 /* Device list insertion */
218 static void list_netdevice(struct net_device *dev)
219 {
220         struct net *net = dev_net(dev);
221 
222         ASSERT_RTNL();
223 
224         write_lock_bh(&dev_base_lock);
225         list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
226         hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
227         hlist_add_head_rcu(&dev->index_hlist,
228                            dev_index_hash(net, dev->ifindex));
229         write_unlock_bh(&dev_base_lock);
230 
231         dev_base_seq_inc(net);
232 }
233 
234 /* Device list removal
235  * caller must respect a RCU grace period before freeing/reusing dev
236  */
237 static void unlist_netdevice(struct net_device *dev)
238 {
239         ASSERT_RTNL();
240 
241         /* Unlink dev from the device chain */
242         write_lock_bh(&dev_base_lock);
243         list_del_rcu(&dev->dev_list);
244         hlist_del_rcu(&dev->name_hlist);
245         hlist_del_rcu(&dev->index_hlist);
246         write_unlock_bh(&dev_base_lock);
247 
248         dev_base_seq_inc(dev_net(dev));
249 }
250 
251 /*
252  *      Our notifier list
253  */
254 
255 static RAW_NOTIFIER_HEAD(netdev_chain);
256 
257 /*
258  *      Device drivers call our routines to queue packets here. We empty the
259  *      queue in the local softnet handler.
260  */
261 
262 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
263 EXPORT_PER_CPU_SYMBOL(softnet_data);
264 
265 #ifdef CONFIG_LOCKDEP
266 /*
267  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
268  * according to dev->type
269  */
270 static const unsigned short netdev_lock_type[] =
271         {ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
272          ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
273          ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
274          ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
275          ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
276          ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
277          ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
278          ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
279          ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
280          ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
281          ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
282          ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
283          ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
284          ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
285          ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
286 
287 static const char *const netdev_lock_name[] =
288         {"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
289          "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
290          "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
291          "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
292          "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
293          "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
294          "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
295          "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
296          "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
297          "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
298          "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
299          "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
300          "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
301          "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
302          "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
303 
304 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
305 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
306 
307 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
308 {
309         int i;
310 
311         for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
312                 if (netdev_lock_type[i] == dev_type)
313                         return i;
314         /* the last key is used by default */
315         return ARRAY_SIZE(netdev_lock_type) - 1;
316 }
317 
318 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
319                                                  unsigned short dev_type)
320 {
321         int i;
322 
323         i = netdev_lock_pos(dev_type);
324         lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
325                                    netdev_lock_name[i]);
326 }
327 
328 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
329 {
330         int i;
331 
332         i = netdev_lock_pos(dev->type);
333         lockdep_set_class_and_name(&dev->addr_list_lock,
334                                    &netdev_addr_lock_key[i],
335                                    netdev_lock_name[i]);
336 }
337 #else
338 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
339                                                  unsigned short dev_type)
340 {
341 }
342 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
343 {
344 }
345 #endif
346 
347 /*******************************************************************************
348 
349                 Protocol management and registration routines
350 
351 *******************************************************************************/
352 
353 /*
354  *      Add a protocol ID to the list. Now that the input handler is
355  *      smarter we can dispense with all the messy stuff that used to be
356  *      here.
357  *
358  *      BEWARE!!! Protocol handlers, mangling input packets,
359  *      MUST BE last in hash buckets and checking protocol handlers
360  *      MUST start from promiscuous ptype_all chain in net_bh.
361  *      It is true now, do not change it.
362  *      Explanation follows: if protocol handler, mangling packet, will
363  *      be the first on list, it is not able to sense, that packet
364  *      is cloned and should be copied-on-write, so that it will
365  *      change it and subsequent readers will get broken packet.
366  *                                                      --ANK (980803)
367  */
368 
369 static inline struct list_head *ptype_head(const struct packet_type *pt)
370 {
371         if (pt->type == htons(ETH_P_ALL))
372                 return &ptype_all;
373         else
374                 return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
375 }
376 
377 /**
378  *      dev_add_pack - add packet handler
379  *      @pt: packet type declaration
380  *
381  *      Add a protocol handler to the networking stack. The passed &packet_type
382  *      is linked into kernel lists and may not be freed until it has been
383  *      removed from the kernel lists.
384  *
385  *      This call does not sleep therefore it can not
386  *      guarantee all CPU's that are in middle of receiving packets
387  *      will see the new packet type (until the next received packet).
388  */
389 
390 void dev_add_pack(struct packet_type *pt)
391 {
392         struct list_head *head = ptype_head(pt);
393 
394         spin_lock(&ptype_lock);
395         list_add_rcu(&pt->list, head);
396         spin_unlock(&ptype_lock);
397 }
398 EXPORT_SYMBOL(dev_add_pack);
399 
400 /**
401  *      __dev_remove_pack        - remove packet handler
402  *      @pt: packet type declaration
403  *
404  *      Remove a protocol handler that was previously added to the kernel
405  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
406  *      from the kernel lists and can be freed or reused once this function
407  *      returns.
408  *
409  *      The packet type might still be in use by receivers
410  *      and must not be freed until after all the CPU's have gone
411  *      through a quiescent state.
412  */
413 void __dev_remove_pack(struct packet_type *pt)
414 {
415         struct list_head *head = ptype_head(pt);
416         struct packet_type *pt1;
417 
418         spin_lock(&ptype_lock);
419 
420         list_for_each_entry(pt1, head, list) {
421                 if (pt == pt1) {
422                         list_del_rcu(&pt->list);
423                         goto out;
424                 }
425         }
426 
427         pr_warn("dev_remove_pack: %p not found\n", pt);
428 out:
429         spin_unlock(&ptype_lock);
430 }
431 EXPORT_SYMBOL(__dev_remove_pack);
432 
433 /**
434  *      dev_remove_pack  - remove packet handler
435  *      @pt: packet type declaration
436  *
437  *      Remove a protocol handler that was previously added to the kernel
438  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
439  *      from the kernel lists and can be freed or reused once this function
440  *      returns.
441  *
442  *      This call sleeps to guarantee that no CPU is looking at the packet
443  *      type after return.
444  */
445 void dev_remove_pack(struct packet_type *pt)
446 {
447         __dev_remove_pack(pt);
448 
449         synchronize_net();
450 }
451 EXPORT_SYMBOL(dev_remove_pack);
452 
453 
454 /**
455  *      dev_add_offload - register offload handlers
456  *      @po: protocol offload declaration
457  *
458  *      Add protocol offload handlers to the networking stack. The passed
459  *      &proto_offload is linked into kernel lists and may not be freed until
460  *      it has been removed from the kernel lists.
461  *
462  *      This call does not sleep therefore it can not
463  *      guarantee all CPU's that are in middle of receiving packets
464  *      will see the new offload handlers (until the next received packet).
465  */
466 void dev_add_offload(struct packet_offload *po)
467 {
468         struct list_head *head = &offload_base;
469 
470         spin_lock(&offload_lock);
471         list_add_rcu(&po->list, head);
472         spin_unlock(&offload_lock);
473 }
474 EXPORT_SYMBOL(dev_add_offload);
475 
476 /**
477  *      __dev_remove_offload     - remove offload handler
478  *      @po: packet offload declaration
479  *
480  *      Remove a protocol offload handler that was previously added to the
481  *      kernel offload handlers by dev_add_offload(). The passed &offload_type
482  *      is removed from the kernel lists and can be freed or reused once this
483  *      function returns.
484  *
485  *      The packet type might still be in use by receivers
486  *      and must not be freed until after all the CPU's have gone
487  *      through a quiescent state.
488  */
489 static void __dev_remove_offload(struct packet_offload *po)
490 {
491         struct list_head *head = &offload_base;
492         struct packet_offload *po1;
493 
494         spin_lock(&offload_lock);
495 
496         list_for_each_entry(po1, head, list) {
497                 if (po == po1) {
498                         list_del_rcu(&po->list);
499                         goto out;
500                 }
501         }
502 
503         pr_warn("dev_remove_offload: %p not found\n", po);
504 out:
505         spin_unlock(&offload_lock);
506 }
507 
508 /**
509  *      dev_remove_offload       - remove packet offload handler
510  *      @po: packet offload declaration
511  *
512  *      Remove a packet offload handler that was previously added to the kernel
513  *      offload handlers by dev_add_offload(). The passed &offload_type is
514  *      removed from the kernel lists and can be freed or reused once this
515  *      function returns.
516  *
517  *      This call sleeps to guarantee that no CPU is looking at the packet
518  *      type after return.
519  */
520 void dev_remove_offload(struct packet_offload *po)
521 {
522         __dev_remove_offload(po);
523 
524         synchronize_net();
525 }
526 EXPORT_SYMBOL(dev_remove_offload);
527 
528 /******************************************************************************
529 
530                       Device Boot-time Settings Routines
531 
532 *******************************************************************************/
533 
534 /* Boot time configuration table */
535 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
536 
537 /**
538  *      netdev_boot_setup_add   - add new setup entry
539  *      @name: name of the device
540  *      @map: configured settings for the device
541  *
542  *      Adds new setup entry to the dev_boot_setup list.  The function
543  *      returns 0 on error and 1 on success.  This is a generic routine to
544  *      all netdevices.
545  */
546 static int netdev_boot_setup_add(char *name, struct ifmap *map)
547 {
548         struct netdev_boot_setup *s;
549         int i;
550 
551         s = dev_boot_setup;
552         for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
553                 if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
554                         memset(s[i].name, 0, sizeof(s[i].name));
555                         strlcpy(s[i].name, name, IFNAMSIZ);
556                         memcpy(&s[i].map, map, sizeof(s[i].map));
557                         break;
558                 }
559         }
560 
561         return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
562 }
563 
564 /**
565  *      netdev_boot_setup_check - check boot time settings
566  *      @dev: the netdevice
567  *
568  *      Check boot time settings for the device.
569  *      The found settings are set for the device to be used
570  *      later in the device probing.
571  *      Returns 0 if no settings found, 1 if they are.
572  */
573 int netdev_boot_setup_check(struct net_device *dev)
574 {
575         struct netdev_boot_setup *s = dev_boot_setup;
576         int i;
577 
578         for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
579                 if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
580                     !strcmp(dev->name, s[i].name)) {
581                         dev->irq        = s[i].map.irq;
582                         dev->base_addr  = s[i].map.base_addr;
583                         dev->mem_start  = s[i].map.mem_start;
584                         dev->mem_end    = s[i].map.mem_end;
585                         return 1;
586                 }
587         }
588         return 0;
589 }
590 EXPORT_SYMBOL(netdev_boot_setup_check);
591 
592 
593 /**
594  *      netdev_boot_base        - get address from boot time settings
595  *      @prefix: prefix for network device
596  *      @unit: id for network device
597  *
598  *      Check boot time settings for the base address of device.
599  *      The found settings are set for the device to be used
600  *      later in the device probing.
601  *      Returns 0 if no settings found.
602  */
603 unsigned long netdev_boot_base(const char *prefix, int unit)
604 {
605         const struct netdev_boot_setup *s = dev_boot_setup;
606         char name[IFNAMSIZ];
607         int i;
608 
609         sprintf(name, "%s%d", prefix, unit);
610 
611         /*
612          * If device already registered then return base of 1
613          * to indicate not to probe for this interface
614          */
615         if (__dev_get_by_name(&init_net, name))
616                 return 1;
617 
618         for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
619                 if (!strcmp(name, s[i].name))
620                         return s[i].map.base_addr;
621         return 0;
622 }
623 
624 /*
625  * Saves at boot time configured settings for any netdevice.
626  */
627 int __init netdev_boot_setup(char *str)
628 {
629         int ints[5];
630         struct ifmap map;
631 
632         str = get_options(str, ARRAY_SIZE(ints), ints);
633         if (!str || !*str)
634                 return 0;
635 
636         /* Save settings */
637         memset(&map, 0, sizeof(map));
638         if (ints[0] > 0)
639                 map.irq = ints[1];
640         if (ints[0] > 1)
641                 map.base_addr = ints[2];
642         if (ints[0] > 2)
643                 map.mem_start = ints[3];
644         if (ints[0] > 3)
645                 map.mem_end = ints[4];
646 
647         /* Add new entry to the list */
648         return netdev_boot_setup_add(str, &map);
649 }
650 
651 __setup("netdev=", netdev_boot_setup);
652 
653 /*******************************************************************************
654 
655                             Device Interface Subroutines
656 
657 *******************************************************************************/
658 
659 /**
660  *      __dev_get_by_name       - find a device by its name
661  *      @net: the applicable net namespace
662  *      @name: name to find
663  *
664  *      Find an interface by name. Must be called under RTNL semaphore
665  *      or @dev_base_lock. If the name is found a pointer to the device
666  *      is returned. If the name is not found then %NULL is returned. The
667  *      reference counters are not incremented so the caller must be
668  *      careful with locks.
669  */
670 
671 struct net_device *__dev_get_by_name(struct net *net, const char *name)
672 {
673         struct net_device *dev;
674         struct hlist_head *head = dev_name_hash(net, name);
675 
676         hlist_for_each_entry(dev, head, name_hlist)
677                 if (!strncmp(dev->name, name, IFNAMSIZ))
678                         return dev;
679 
680         return NULL;
681 }
682 EXPORT_SYMBOL(__dev_get_by_name);
683 
684 /**
685  *      dev_get_by_name_rcu     - find a device by its name
686  *      @net: the applicable net namespace
687  *      @name: name to find
688  *
689  *      Find an interface by name.
690  *      If the name is found a pointer to the device is returned.
691  *      If the name is not found then %NULL is returned.
692  *      The reference counters are not incremented so the caller must be
693  *      careful with locks. The caller must hold RCU lock.
694  */
695 
696 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
697 {
698         struct net_device *dev;
699         struct hlist_head *head = dev_name_hash(net, name);
700 
701         hlist_for_each_entry_rcu(dev, head, name_hlist)
702                 if (!strncmp(dev->name, name, IFNAMSIZ))
703                         return dev;
704 
705         return NULL;
706 }
707 EXPORT_SYMBOL(dev_get_by_name_rcu);
708 
709 /**
710  *      dev_get_by_name         - find a device by its name
711  *      @net: the applicable net namespace
712  *      @name: name to find
713  *
714  *      Find an interface by name. This can be called from any
715  *      context and does its own locking. The returned handle has
716  *      the usage count incremented and the caller must use dev_put() to
717  *      release it when it is no longer needed. %NULL is returned if no
718  *      matching device is found.
719  */
720 
721 struct net_device *dev_get_by_name(struct net *net, const char *name)
722 {
723         struct net_device *dev;
724 
725         rcu_read_lock();
726         dev = dev_get_by_name_rcu(net, name);
727         if (dev)
728                 dev_hold(dev);
729         rcu_read_unlock();
730         return dev;
731 }
732 EXPORT_SYMBOL(dev_get_by_name);
733 
734 /**
735  *      __dev_get_by_index - find a device by its ifindex
736  *      @net: the applicable net namespace
737  *      @ifindex: index of device
738  *
739  *      Search for an interface by index. Returns %NULL if the device
740  *      is not found or a pointer to the device. The device has not
741  *      had its reference counter increased so the caller must be careful
742  *      about locking. The caller must hold either the RTNL semaphore
743  *      or @dev_base_lock.
744  */
745 
746 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
747 {
748         struct net_device *dev;
749         struct hlist_head *head = dev_index_hash(net, ifindex);
750 
751         hlist_for_each_entry(dev, head, index_hlist)
752                 if (dev->ifindex == ifindex)
753                         return dev;
754 
755         return NULL;
756 }
757 EXPORT_SYMBOL(__dev_get_by_index);
758 
759 /**
760  *      dev_get_by_index_rcu - find a device by its ifindex
761  *      @net: the applicable net namespace
762  *      @ifindex: index of device
763  *
764  *      Search for an interface by index. Returns %NULL if the device
765  *      is not found or a pointer to the device. The device has not
766  *      had its reference counter increased so the caller must be careful
767  *      about locking. The caller must hold RCU lock.
768  */
769 
770 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
771 {
772         struct net_device *dev;
773         struct hlist_head *head = dev_index_hash(net, ifindex);
774 
775         hlist_for_each_entry_rcu(dev, head, index_hlist)
776                 if (dev->ifindex == ifindex)
777                         return dev;
778 
779         return NULL;
780 }
781 EXPORT_SYMBOL(dev_get_by_index_rcu);
782 
783 
784 /**
785  *      dev_get_by_index - find a device by its ifindex
786  *      @net: the applicable net namespace
787  *      @ifindex: index of device
788  *
789  *      Search for an interface by index. Returns NULL if the device
790  *      is not found or a pointer to the device. The device returned has
791  *      had a reference added and the pointer is safe until the user calls
792  *      dev_put to indicate they have finished with it.
793  */
794 
795 struct net_device *dev_get_by_index(struct net *net, int ifindex)
796 {
797         struct net_device *dev;
798 
799         rcu_read_lock();
800         dev = dev_get_by_index_rcu(net, ifindex);
801         if (dev)
802                 dev_hold(dev);
803         rcu_read_unlock();
804         return dev;
805 }
806 EXPORT_SYMBOL(dev_get_by_index);
807 
808 /**
809  *      netdev_get_name - get a netdevice name, knowing its ifindex.
810  *      @net: network namespace
811  *      @name: a pointer to the buffer where the name will be stored.
812  *      @ifindex: the ifindex of the interface to get the name from.
813  *
814  *      The use of raw_seqcount_begin() and cond_resched() before
815  *      retrying is required as we want to give the writers a chance
816  *      to complete when CONFIG_PREEMPT is not set.
817  */
818 int netdev_get_name(struct net *net, char *name, int ifindex)
819 {
820         struct net_device *dev;
821         unsigned int seq;
822 
823 retry:
824         seq = raw_seqcount_begin(&devnet_rename_seq);
825         rcu_read_lock();
826         dev = dev_get_by_index_rcu(net, ifindex);
827         if (!dev) {
828                 rcu_read_unlock();
829                 return -ENODEV;
830         }
831 
832         strcpy(name, dev->name);
833         rcu_read_unlock();
834         if (read_seqcount_retry(&devnet_rename_seq, seq)) {
835                 cond_resched();
836                 goto retry;
837         }
838 
839         return 0;
840 }
841 
842 /**
843  *      dev_getbyhwaddr_rcu - find a device by its hardware address
844  *      @net: the applicable net namespace
845  *      @type: media type of device
846  *      @ha: hardware address
847  *
848  *      Search for an interface by MAC address. Returns NULL if the device
849  *      is not found or a pointer to the device.
850  *      The caller must hold RCU or RTNL.
851  *      The returned device has not had its ref count increased
852  *      and the caller must therefore be careful about locking
853  *
854  */
855 
856 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
857                                        const char *ha)
858 {
859         struct net_device *dev;
860 
861         for_each_netdev_rcu(net, dev)
862                 if (dev->type == type &&
863                     !memcmp(dev->dev_addr, ha, dev->addr_len))
864                         return dev;
865 
866         return NULL;
867 }
868 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
869 
870 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
871 {
872         struct net_device *dev;
873 
874         ASSERT_RTNL();
875         for_each_netdev(net, dev)
876                 if (dev->type == type)
877                         return dev;
878 
879         return NULL;
880 }
881 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
882 
883 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
884 {
885         struct net_device *dev, *ret = NULL;
886 
887         rcu_read_lock();
888         for_each_netdev_rcu(net, dev)
889                 if (dev->type == type) {
890                         dev_hold(dev);
891                         ret = dev;
892                         break;
893                 }
894         rcu_read_unlock();
895         return ret;
896 }
897 EXPORT_SYMBOL(dev_getfirstbyhwtype);
898 
899 /**
900  *      dev_get_by_flags_rcu - find any device with given flags
901  *      @net: the applicable net namespace
902  *      @if_flags: IFF_* values
903  *      @mask: bitmask of bits in if_flags to check
904  *
905  *      Search for any interface with the given flags. Returns NULL if a device
906  *      is not found or a pointer to the device. Must be called inside
907  *      rcu_read_lock(), and result refcount is unchanged.
908  */
909 
910 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
911                                     unsigned short mask)
912 {
913         struct net_device *dev, *ret;
914 
915         ret = NULL;
916         for_each_netdev_rcu(net, dev) {
917                 if (((dev->flags ^ if_flags) & mask) == 0) {
918                         ret = dev;
919                         break;
920                 }
921         }
922         return ret;
923 }
924 EXPORT_SYMBOL(dev_get_by_flags_rcu);
925 
926 /**
927  *      dev_valid_name - check if name is okay for network device
928  *      @name: name string
929  *
930  *      Network device names need to be valid file names to
931  *      to allow sysfs to work.  We also disallow any kind of
932  *      whitespace.
933  */
934 bool dev_valid_name(const char *name)
935 {
936         if (*name == '\0')
937                 return false;
938         if (strlen(name) >= IFNAMSIZ)
939                 return false;
940         if (!strcmp(name, ".") || !strcmp(name, ".."))
941                 return false;
942 
943         while (*name) {
944                 if (*name == '/' || isspace(*name))
945                         return false;
946                 name++;
947         }
948         return true;
949 }
950 EXPORT_SYMBOL(dev_valid_name);
951 
952 /**
953  *      __dev_alloc_name - allocate a name for a device
954  *      @net: network namespace to allocate the device name in
955  *      @name: name format string
956  *      @buf:  scratch buffer and result name string
957  *
958  *      Passed a format string - eg "lt%d" it will try and find a suitable
959  *      id. It scans list of devices to build up a free map, then chooses
960  *      the first empty slot. The caller must hold the dev_base or rtnl lock
961  *      while allocating the name and adding the device in order to avoid
962  *      duplicates.
963  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
964  *      Returns the number of the unit assigned or a negative errno code.
965  */
966 
967 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
968 {
969         int i = 0;
970         const char *p;
971         const int max_netdevices = 8*PAGE_SIZE;
972         unsigned long *inuse;
973         struct net_device *d;
974 
975         p = strnchr(name, IFNAMSIZ-1, '%');
976         if (p) {
977                 /*
978                  * Verify the string as this thing may have come from
979                  * the user.  There must be either one "%d" and no other "%"
980                  * characters.
981                  */
982                 if (p[1] != 'd' || strchr(p + 2, '%'))
983                         return -EINVAL;
984 
985                 /* Use one page as a bit array of possible slots */
986                 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
987                 if (!inuse)
988                         return -ENOMEM;
989 
990                 for_each_netdev(net, d) {
991                         if (!sscanf(d->name, name, &i))
992                                 continue;
993                         if (i < 0 || i >= max_netdevices)
994                                 continue;
995 
996                         /*  avoid cases where sscanf is not exact inverse of printf */
997                         snprintf(buf, IFNAMSIZ, name, i);
998                         if (!strncmp(buf, d->name, IFNAMSIZ))
999                                 set_bit(i, inuse);
1000                 }
1001 
1002                 i = find_first_zero_bit(inuse, max_netdevices);
1003                 free_page((unsigned long) inuse);
1004         }
1005 
1006         if (buf != name)
1007                 snprintf(buf, IFNAMSIZ, name, i);
1008         if (!__dev_get_by_name(net, buf))
1009                 return i;
1010 
1011         /* It is possible to run out of possible slots
1012          * when the name is long and there isn't enough space left
1013          * for the digits, or if all bits are used.
1014          */
1015         return -ENFILE;
1016 }
1017 
1018 /**
1019  *      dev_alloc_name - allocate a name for a device
1020  *      @dev: device
1021  *      @name: name format string
1022  *
1023  *      Passed a format string - eg "lt%d" it will try and find a suitable
1024  *      id. It scans list of devices to build up a free map, then chooses
1025  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1026  *      while allocating the name and adding the device in order to avoid
1027  *      duplicates.
1028  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1029  *      Returns the number of the unit assigned or a negative errno code.
1030  */
1031 
1032 int dev_alloc_name(struct net_device *dev, const char *name)
1033 {
1034         char buf[IFNAMSIZ];
1035         struct net *net;
1036         int ret;
1037 
1038         BUG_ON(!dev_net(dev));
1039         net = dev_net(dev);
1040         ret = __dev_alloc_name(net, name, buf);
1041         if (ret >= 0)
1042                 strlcpy(dev->name, buf, IFNAMSIZ);
1043         return ret;
1044 }
1045 EXPORT_SYMBOL(dev_alloc_name);
1046 
1047 static int dev_alloc_name_ns(struct net *net,
1048                              struct net_device *dev,
1049                              const char *name)
1050 {
1051         char buf[IFNAMSIZ];
1052         int ret;
1053 
1054         ret = __dev_alloc_name(net, name, buf);
1055         if (ret >= 0)
1056                 strlcpy(dev->name, buf, IFNAMSIZ);
1057         return ret;
1058 }
1059 
1060 static int dev_get_valid_name(struct net *net,
1061                               struct net_device *dev,
1062                               const char *name)
1063 {
1064         BUG_ON(!net);
1065 
1066         if (!dev_valid_name(name))
1067                 return -EINVAL;
1068 
1069         if (strchr(name, '%'))
1070                 return dev_alloc_name_ns(net, dev, name);
1071         else if (__dev_get_by_name(net, name))
1072                 return -EEXIST;
1073         else if (dev->name != name)
1074                 strlcpy(dev->name, name, IFNAMSIZ);
1075 
1076         return 0;
1077 }
1078 
1079 /**
1080  *      dev_change_name - change name of a device
1081  *      @dev: device
1082  *      @newname: name (or format string) must be at least IFNAMSIZ
1083  *
1084  *      Change name of a device, can pass format strings "eth%d".
1085  *      for wildcarding.
1086  */
1087 int dev_change_name(struct net_device *dev, const char *newname)
1088 {
1089         unsigned char old_assign_type;
1090         char oldname[IFNAMSIZ];
1091         int err = 0;
1092         int ret;
1093         struct net *net;
1094 
1095         ASSERT_RTNL();
1096         BUG_ON(!dev_net(dev));
1097 
1098         net = dev_net(dev);
1099         if (dev->flags & IFF_UP)
1100                 return -EBUSY;
1101 
1102         write_seqcount_begin(&devnet_rename_seq);
1103 
1104         if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1105                 write_seqcount_end(&devnet_rename_seq);
1106                 return 0;
1107         }
1108 
1109         memcpy(oldname, dev->name, IFNAMSIZ);
1110 
1111         err = dev_get_valid_name(net, dev, newname);
1112         if (err < 0) {
1113                 write_seqcount_end(&devnet_rename_seq);
1114                 return err;
1115         }
1116 
1117         if (oldname[0] && !strchr(oldname, '%'))
1118                 netdev_info(dev, "renamed from %s\n", oldname);
1119 
1120         old_assign_type = dev->name_assign_type;
1121         dev->name_assign_type = NET_NAME_RENAMED;
1122 
1123 rollback:
1124         ret = device_rename(&dev->dev, dev->name);
1125         if (ret) {
1126                 memcpy(dev->name, oldname, IFNAMSIZ);
1127                 dev->name_assign_type = old_assign_type;
1128                 write_seqcount_end(&devnet_rename_seq);
1129                 return ret;
1130         }
1131 
1132         write_seqcount_end(&devnet_rename_seq);
1133 
1134         netdev_adjacent_rename_links(dev, oldname);
1135 
1136         write_lock_bh(&dev_base_lock);
1137         hlist_del_rcu(&dev->name_hlist);
1138         write_unlock_bh(&dev_base_lock);
1139 
1140         synchronize_rcu();
1141 
1142         write_lock_bh(&dev_base_lock);
1143         hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1144         write_unlock_bh(&dev_base_lock);
1145 
1146         ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1147         ret = notifier_to_errno(ret);
1148 
1149         if (ret) {
1150                 /* err >= 0 after dev_alloc_name() or stores the first errno */
1151                 if (err >= 0) {
1152                         err = ret;
1153                         write_seqcount_begin(&devnet_rename_seq);
1154                         memcpy(dev->name, oldname, IFNAMSIZ);
1155                         memcpy(oldname, newname, IFNAMSIZ);
1156                         dev->name_assign_type = old_assign_type;
1157                         old_assign_type = NET_NAME_RENAMED;
1158                         goto rollback;
1159                 } else {
1160                         pr_err("%s: name change rollback failed: %d\n",
1161                                dev->name, ret);
1162                 }
1163         }
1164 
1165         return err;
1166 }
1167 
1168 /**
1169  *      dev_set_alias - change ifalias of a device
1170  *      @dev: device
1171  *      @alias: name up to IFALIASZ
1172  *      @len: limit of bytes to copy from info
1173  *
1174  *      Set ifalias for a device,
1175  */
1176 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1177 {
1178         char *new_ifalias;
1179 
1180         ASSERT_RTNL();
1181 
1182         if (len >= IFALIASZ)
1183                 return -EINVAL;
1184 
1185         if (!len) {
1186                 kfree(dev->ifalias);
1187                 dev->ifalias = NULL;
1188                 return 0;
1189         }
1190 
1191         new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1192         if (!new_ifalias)
1193                 return -ENOMEM;
1194         dev->ifalias = new_ifalias;
1195 
1196         strlcpy(dev->ifalias, alias, len+1);
1197         return len;
1198 }
1199 
1200 
1201 /**
1202  *      netdev_features_change - device changes features
1203  *      @dev: device to cause notification
1204  *
1205  *      Called to indicate a device has changed features.
1206  */
1207 void netdev_features_change(struct net_device *dev)
1208 {
1209         call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1210 }
1211 EXPORT_SYMBOL(netdev_features_change);
1212 
1213 /**
1214  *      netdev_state_change - device changes state
1215  *      @dev: device to cause notification
1216  *
1217  *      Called to indicate a device has changed state. This function calls
1218  *      the notifier chains for netdev_chain and sends a NEWLINK message
1219  *      to the routing socket.
1220  */
1221 void netdev_state_change(struct net_device *dev)
1222 {
1223         if (dev->flags & IFF_UP) {
1224                 struct netdev_notifier_change_info change_info;
1225 
1226                 change_info.flags_changed = 0;
1227                 call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
1228                                               &change_info.info);
1229                 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
1230         }
1231 }
1232 EXPORT_SYMBOL(netdev_state_change);
1233 
1234 /**
1235  *      netdev_notify_peers - notify network peers about existence of @dev
1236  *      @dev: network device
1237  *
1238  * Generate traffic such that interested network peers are aware of
1239  * @dev, such as by generating a gratuitous ARP. This may be used when
1240  * a device wants to inform the rest of the network about some sort of
1241  * reconfiguration such as a failover event or virtual machine
1242  * migration.
1243  */
1244 void netdev_notify_peers(struct net_device *dev)
1245 {
1246         rtnl_lock();
1247         call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1248         rtnl_unlock();
1249 }
1250 EXPORT_SYMBOL(netdev_notify_peers);
1251 
1252 static int __dev_open(struct net_device *dev)
1253 {
1254         const struct net_device_ops *ops = dev->netdev_ops;
1255         int ret;
1256 
1257         ASSERT_RTNL();
1258 
1259         if (!netif_device_present(dev))
1260                 return -ENODEV;
1261 
1262         /* Block netpoll from trying to do any rx path servicing.
1263          * If we don't do this there is a chance ndo_poll_controller
1264          * or ndo_poll may be running while we open the device
1265          */
1266         netpoll_poll_disable(dev);
1267 
1268         ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1269         ret = notifier_to_errno(ret);
1270         if (ret)
1271                 return ret;
1272 
1273         set_bit(__LINK_STATE_START, &dev->state);
1274 
1275         if (ops->ndo_validate_addr)
1276                 ret = ops->ndo_validate_addr(dev);
1277 
1278         if (!ret && ops->ndo_open)
1279                 ret = ops->ndo_open(dev);
1280 
1281         netpoll_poll_enable(dev);
1282 
1283         if (ret)
1284                 clear_bit(__LINK_STATE_START, &dev->state);
1285         else {
1286                 dev->flags |= IFF_UP;
1287                 net_dmaengine_get();
1288                 dev_set_rx_mode(dev);
1289                 dev_activate(dev);
1290                 add_device_randomness(dev->dev_addr, dev->addr_len);
1291         }
1292 
1293         return ret;
1294 }
1295 
1296 /**
1297  *      dev_open        - prepare an interface for use.
1298  *      @dev:   device to open
1299  *
1300  *      Takes a device from down to up state. The device's private open
1301  *      function is invoked and then the multicast lists are loaded. Finally
1302  *      the device is moved into the up state and a %NETDEV_UP message is
1303  *      sent to the netdev notifier chain.
1304  *
1305  *      Calling this function on an active interface is a nop. On a failure
1306  *      a negative errno code is returned.
1307  */
1308 int dev_open(struct net_device *dev)
1309 {
1310         int ret;
1311 
1312         if (dev->flags & IFF_UP)
1313                 return 0;
1314 
1315         ret = __dev_open(dev);
1316         if (ret < 0)
1317                 return ret;
1318 
1319         rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1320         call_netdevice_notifiers(NETDEV_UP, dev);
1321 
1322         return ret;
1323 }
1324 EXPORT_SYMBOL(dev_open);
1325 
1326 static int __dev_close_many(struct list_head *head)
1327 {
1328         struct net_device *dev;
1329 
1330         ASSERT_RTNL();
1331         might_sleep();
1332 
1333         list_for_each_entry(dev, head, close_list) {
1334                 /* Temporarily disable netpoll until the interface is down */
1335                 netpoll_poll_disable(dev);
1336 
1337                 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1338 
1339                 clear_bit(__LINK_STATE_START, &dev->state);
1340 
1341                 /* Synchronize to scheduled poll. We cannot touch poll list, it
1342                  * can be even on different cpu. So just clear netif_running().
1343                  *
1344                  * dev->stop() will invoke napi_disable() on all of it's
1345                  * napi_struct instances on this device.
1346                  */
1347                 smp_mb__after_atomic(); /* Commit netif_running(). */
1348         }
1349 
1350         dev_deactivate_many(head);
1351 
1352         list_for_each_entry(dev, head, close_list) {
1353                 const struct net_device_ops *ops = dev->netdev_ops;
1354 
1355                 /*
1356                  *      Call the device specific close. This cannot fail.
1357                  *      Only if device is UP
1358                  *
1359                  *      We allow it to be called even after a DETACH hot-plug
1360                  *      event.
1361                  */
1362                 if (ops->ndo_stop)
1363                         ops->ndo_stop(dev);
1364 
1365                 dev->flags &= ~IFF_UP;
1366                 net_dmaengine_put();
1367                 netpoll_poll_enable(dev);
1368         }
1369 
1370         return 0;
1371 }
1372 
1373 static int __dev_close(struct net_device *dev)
1374 {
1375         int retval;
1376         LIST_HEAD(single);
1377 
1378         list_add(&dev->close_list, &single);
1379         retval = __dev_close_many(&single);
1380         list_del(&single);
1381 
1382         return retval;
1383 }
1384 
1385 static int dev_close_many(struct list_head *head)
1386 {
1387         struct net_device *dev, *tmp;
1388 
1389         /* Remove the devices that don't need to be closed */
1390         list_for_each_entry_safe(dev, tmp, head, close_list)
1391                 if (!(dev->flags & IFF_UP))
1392                         list_del_init(&dev->close_list);
1393 
1394         __dev_close_many(head);
1395 
1396         list_for_each_entry_safe(dev, tmp, head, close_list) {
1397                 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1398                 call_netdevice_notifiers(NETDEV_DOWN, dev);
1399                 list_del_init(&dev->close_list);
1400         }
1401 
1402         return 0;
1403 }
1404 
1405 /**
1406  *      dev_close - shutdown an interface.
1407  *      @dev: device to shutdown
1408  *
1409  *      This function moves an active device into down state. A
1410  *      %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1411  *      is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1412  *      chain.
1413  */
1414 int dev_close(struct net_device *dev)
1415 {
1416         if (dev->flags & IFF_UP) {
1417                 LIST_HEAD(single);
1418 
1419                 list_add(&dev->close_list, &single);
1420                 dev_close_many(&single);
1421                 list_del(&single);
1422         }
1423         return 0;
1424 }
1425 EXPORT_SYMBOL(dev_close);
1426 
1427 
1428 /**
1429  *      dev_disable_lro - disable Large Receive Offload on a device
1430  *      @dev: device
1431  *
1432  *      Disable Large Receive Offload (LRO) on a net device.  Must be
1433  *      called under RTNL.  This is needed if received packets may be
1434  *      forwarded to another interface.
1435  */
1436 void dev_disable_lro(struct net_device *dev)
1437 {
1438         /*
1439          * If we're trying to disable lro on a vlan device
1440          * use the underlying physical device instead
1441          */
1442         if (is_vlan_dev(dev))
1443                 dev = vlan_dev_real_dev(dev);
1444 
1445         /* the same for macvlan devices */
1446         if (netif_is_macvlan(dev))
1447                 dev = macvlan_dev_real_dev(dev);
1448 
1449         dev->wanted_features &= ~NETIF_F_LRO;
1450         netdev_update_features(dev);
1451 
1452         if (unlikely(dev->features & NETIF_F_LRO))
1453                 netdev_WARN(dev, "failed to disable LRO!\n");
1454 }
1455 EXPORT_SYMBOL(dev_disable_lro);
1456 
1457 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1458                                    struct net_device *dev)
1459 {
1460         struct netdev_notifier_info info;
1461 
1462         netdev_notifier_info_init(&info, dev);
1463         return nb->notifier_call(nb, val, &info);
1464 }
1465 
1466 static int dev_boot_phase = 1;
1467 
1468 /**
1469  *      register_netdevice_notifier - register a network notifier block
1470  *      @nb: notifier
1471  *
1472  *      Register a notifier to be called when network device events occur.
1473  *      The notifier passed is linked into the kernel structures and must
1474  *      not be reused until it has been unregistered. A negative errno code
1475  *      is returned on a failure.
1476  *
1477  *      When registered all registration and up events are replayed
1478  *      to the new notifier to allow device to have a race free
1479  *      view of the network device list.
1480  */
1481 
1482 int register_netdevice_notifier(struct notifier_block *nb)
1483 {
1484         struct net_device *dev;
1485         struct net_device *last;
1486         struct net *net;
1487         int err;
1488 
1489         rtnl_lock();
1490         err = raw_notifier_chain_register(&netdev_chain, nb);
1491         if (err)
1492                 goto unlock;
1493         if (dev_boot_phase)
1494                 goto unlock;
1495         for_each_net(net) {
1496                 for_each_netdev(net, dev) {
1497                         err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1498                         err = notifier_to_errno(err);
1499                         if (err)
1500                                 goto rollback;
1501 
1502                         if (!(dev->flags & IFF_UP))
1503                                 continue;
1504 
1505                         call_netdevice_notifier(nb, NETDEV_UP, dev);
1506                 }
1507         }
1508 
1509 unlock:
1510         rtnl_unlock();
1511         return err;
1512 
1513 rollback:
1514         last = dev;
1515         for_each_net(net) {
1516                 for_each_netdev(net, dev) {
1517                         if (dev == last)
1518                                 goto outroll;
1519 
1520                         if (dev->flags & IFF_UP) {
1521                                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1522                                                         dev);
1523                                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1524                         }
1525                         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1526                 }
1527         }
1528 
1529 outroll:
1530         raw_notifier_chain_unregister(&netdev_chain, nb);
1531         goto unlock;
1532 }
1533 EXPORT_SYMBOL(register_netdevice_notifier);
1534 
1535 /**
1536  *      unregister_netdevice_notifier - unregister a network notifier block
1537  *      @nb: notifier
1538  *
1539  *      Unregister a notifier previously registered by
1540  *      register_netdevice_notifier(). The notifier is unlinked into the
1541  *      kernel structures and may then be reused. A negative errno code
1542  *      is returned on a failure.
1543  *
1544  *      After unregistering unregister and down device events are synthesized
1545  *      for all devices on the device list to the removed notifier to remove
1546  *      the need for special case cleanup code.
1547  */
1548 
1549 int unregister_netdevice_notifier(struct notifier_block *nb)
1550 {
1551         struct net_device *dev;
1552         struct net *net;
1553         int err;
1554 
1555         rtnl_lock();
1556         err = raw_notifier_chain_unregister(&netdev_chain, nb);
1557         if (err)
1558                 goto unlock;
1559 
1560         for_each_net(net) {
1561                 for_each_netdev(net, dev) {
1562                         if (dev->flags & IFF_UP) {
1563                                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1564                                                         dev);
1565                                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1566                         }
1567                         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1568                 }
1569         }
1570 unlock:
1571         rtnl_unlock();
1572         return err;
1573 }
1574 EXPORT_SYMBOL(unregister_netdevice_notifier);
1575 
1576 /**
1577  *      call_netdevice_notifiers_info - call all network notifier blocks
1578  *      @val: value passed unmodified to notifier function
1579  *      @dev: net_device pointer passed unmodified to notifier function
1580  *      @info: notifier information data
1581  *
1582  *      Call all network notifier blocks.  Parameters and return value
1583  *      are as for raw_notifier_call_chain().
1584  */
1585 
1586 static int call_netdevice_notifiers_info(unsigned long val,
1587                                          struct net_device *dev,
1588                                          struct netdev_notifier_info *info)
1589 {
1590         ASSERT_RTNL();
1591         netdev_notifier_info_init(info, dev);
1592         return raw_notifier_call_chain(&netdev_chain, val, info);
1593 }
1594 
1595 /**
1596  *      call_netdevice_notifiers - call all network notifier blocks
1597  *      @val: value passed unmodified to notifier function
1598  *      @dev: net_device pointer passed unmodified to notifier function
1599  *
1600  *      Call all network notifier blocks.  Parameters and return value
1601  *      are as for raw_notifier_call_chain().
1602  */
1603 
1604 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1605 {
1606         struct netdev_notifier_info info;
1607 
1608         return call_netdevice_notifiers_info(val, dev, &info);
1609 }
1610 EXPORT_SYMBOL(call_netdevice_notifiers);
1611 
1612 static struct static_key netstamp_needed __read_mostly;
1613 #ifdef HAVE_JUMP_LABEL
1614 /* We are not allowed to call static_key_slow_dec() from irq context
1615  * If net_disable_timestamp() is called from irq context, defer the
1616  * static_key_slow_dec() calls.
1617  */
1618 static atomic_t netstamp_needed_deferred;
1619 #endif
1620 
1621 void net_enable_timestamp(void)
1622 {
1623 #ifdef HAVE_JUMP_LABEL
1624         int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
1625 
1626         if (deferred) {
1627                 while (--deferred)
1628                         static_key_slow_dec(&netstamp_needed);
1629                 return;
1630         }
1631 #endif
1632         static_key_slow_inc(&netstamp_needed);
1633 }
1634 EXPORT_SYMBOL(net_enable_timestamp);
1635 
1636 void net_disable_timestamp(void)
1637 {
1638 #ifdef HAVE_JUMP_LABEL
1639         if (in_interrupt()) {
1640                 atomic_inc(&netstamp_needed_deferred);
1641                 return;
1642         }
1643 #endif
1644         static_key_slow_dec(&netstamp_needed);
1645 }
1646 EXPORT_SYMBOL(net_disable_timestamp);
1647 
1648 static inline void net_timestamp_set(struct sk_buff *skb)
1649 {
1650         skb->tstamp.tv64 = 0;
1651         if (static_key_false(&netstamp_needed))
1652                 __net_timestamp(skb);
1653 }
1654 
1655 #define net_timestamp_check(COND, SKB)                  \
1656         if (static_key_false(&netstamp_needed)) {               \
1657                 if ((COND) && !(SKB)->tstamp.tv64)      \
1658                         __net_timestamp(SKB);           \
1659         }                                               \
1660 
1661 bool is_skb_forwardable(struct net_device *dev, struct sk_buff *skb)
1662 {
1663         unsigned int len;
1664 
1665         if (!(dev->flags & IFF_UP))
1666                 return false;
1667 
1668         len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1669         if (skb->len <= len)
1670                 return true;
1671 
1672         /* if TSO is enabled, we don't care about the length as the packet
1673          * could be forwarded without being segmented before
1674          */
1675         if (skb_is_gso(skb))
1676                 return true;
1677 
1678         return false;
1679 }
1680 EXPORT_SYMBOL_GPL(is_skb_forwardable);
1681 
1682 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1683 {
1684         if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
1685                 if (skb_copy_ubufs(skb, GFP_ATOMIC)) {
1686                         atomic_long_inc(&dev->rx_dropped);
1687                         kfree_skb(skb);
1688                         return NET_RX_DROP;
1689                 }
1690         }
1691 
1692         if (unlikely(!is_skb_forwardable(dev, skb))) {
1693                 atomic_long_inc(&dev->rx_dropped);
1694                 kfree_skb(skb);
1695                 return NET_RX_DROP;
1696         }
1697 
1698         skb_scrub_packet(skb, true);
1699         skb->protocol = eth_type_trans(skb, dev);
1700 
1701         return 0;
1702 }
1703 EXPORT_SYMBOL_GPL(__dev_forward_skb);
1704 
1705 /**
1706  * dev_forward_skb - loopback an skb to another netif
1707  *
1708  * @dev: destination network device
1709  * @skb: buffer to forward
1710  *
1711  * return values:
1712  *      NET_RX_SUCCESS  (no congestion)
1713  *      NET_RX_DROP     (packet was dropped, but freed)
1714  *
1715  * dev_forward_skb can be used for injecting an skb from the
1716  * start_xmit function of one device into the receive queue
1717  * of another device.
1718  *
1719  * The receiving device may be in another namespace, so
1720  * we have to clear all information in the skb that could
1721  * impact namespace isolation.
1722  */
1723 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1724 {
1725         return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
1726 }
1727 EXPORT_SYMBOL_GPL(dev_forward_skb);
1728 
1729 static inline int deliver_skb(struct sk_buff *skb,
1730                               struct packet_type *pt_prev,
1731                               struct net_device *orig_dev)
1732 {
1733         if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
1734                 return -ENOMEM;
1735         atomic_inc(&skb->users);
1736         return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1737 }
1738 
1739 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
1740 {
1741         if (!ptype->af_packet_priv || !skb->sk)
1742                 return false;
1743 
1744         if (ptype->id_match)
1745                 return ptype->id_match(ptype, skb->sk);
1746         else if ((struct sock *)ptype->af_packet_priv == skb->sk)
1747                 return true;
1748 
1749         return false;
1750 }
1751 
1752 /*
1753  *      Support routine. Sends outgoing frames to any network
1754  *      taps currently in use.
1755  */
1756 
1757 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1758 {
1759         struct packet_type *ptype;
1760         struct sk_buff *skb2 = NULL;
1761         struct packet_type *pt_prev = NULL;
1762 
1763         rcu_read_lock();
1764         list_for_each_entry_rcu(ptype, &ptype_all, list) {
1765                 /* Never send packets back to the socket
1766                  * they originated from - MvS (miquels@drinkel.ow.org)
1767                  */
1768                 if ((ptype->dev == dev || !ptype->dev) &&
1769                     (!skb_loop_sk(ptype, skb))) {
1770                         if (pt_prev) {
1771                                 deliver_skb(skb2, pt_prev, skb->dev);
1772                                 pt_prev = ptype;
1773                                 continue;
1774                         }
1775 
1776                         skb2 = skb_clone(skb, GFP_ATOMIC);
1777                         if (!skb2)
1778                                 break;
1779 
1780                         net_timestamp_set(skb2);
1781 
1782                         /* skb->nh should be correctly
1783                            set by sender, so that the second statement is
1784                            just protection against buggy protocols.
1785                          */
1786                         skb_reset_mac_header(skb2);
1787 
1788                         if (skb_network_header(skb2) < skb2->data ||
1789                             skb_network_header(skb2) > skb_tail_pointer(skb2)) {
1790                                 net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
1791                                                      ntohs(skb2->protocol),
1792                                                      dev->name);
1793                                 skb_reset_network_header(skb2);
1794                         }
1795 
1796                         skb2->transport_header = skb2->network_header;
1797                         skb2->pkt_type = PACKET_OUTGOING;
1798                         pt_prev = ptype;
1799                 }
1800         }
1801         if (pt_prev)
1802                 pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
1803         rcu_read_unlock();
1804 }
1805 
1806 /**
1807  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1808  * @dev: Network device
1809  * @txq: number of queues available
1810  *
1811  * If real_num_tx_queues is changed the tc mappings may no longer be
1812  * valid. To resolve this verify the tc mapping remains valid and if
1813  * not NULL the mapping. With no priorities mapping to this
1814  * offset/count pair it will no longer be used. In the worst case TC0
1815  * is invalid nothing can be done so disable priority mappings. If is
1816  * expected that drivers will fix this mapping if they can before
1817  * calling netif_set_real_num_tx_queues.
1818  */
1819 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1820 {
1821         int i;
1822         struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
1823 
1824         /* If TC0 is invalidated disable TC mapping */
1825         if (tc->offset + tc->count > txq) {
1826                 pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1827                 dev->num_tc = 0;
1828                 return;
1829         }
1830 
1831         /* Invalidated prio to tc mappings set to TC0 */
1832         for (i = 1; i < TC_BITMASK + 1; i++) {
1833                 int q = netdev_get_prio_tc_map(dev, i);
1834 
1835                 tc = &dev->tc_to_txq[q];
1836                 if (tc->offset + tc->count > txq) {
1837                         pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
1838                                 i, q);
1839                         netdev_set_prio_tc_map(dev, i, 0);
1840                 }
1841         }
1842 }
1843 
1844 #ifdef CONFIG_XPS
1845 static DEFINE_MUTEX(xps_map_mutex);
1846 #define xmap_dereference(P)             \
1847         rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
1848 
1849 static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
1850                                         int cpu, u16 index)
1851 {
1852         struct xps_map *map = NULL;
1853         int pos;
1854 
1855         if (dev_maps)
1856                 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1857 
1858         for (pos = 0; map && pos < map->len; pos++) {
1859                 if (map->queues[pos] == index) {
1860                         if (map->len > 1) {
1861                                 map->queues[pos] = map->queues[--map->len];
1862                         } else {
1863                                 RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1864                                 kfree_rcu(map, rcu);
1865                                 map = NULL;
1866                         }
1867                         break;
1868                 }
1869         }
1870 
1871         return map;
1872 }
1873 
1874 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1875 {
1876         struct xps_dev_maps *dev_maps;
1877         int cpu, i;
1878         bool active = false;
1879 
1880         mutex_lock(&xps_map_mutex);
1881         dev_maps = xmap_dereference(dev->xps_maps);
1882 
1883         if (!dev_maps)
1884                 goto out_no_maps;
1885 
1886         for_each_possible_cpu(cpu) {
1887                 for (i = index; i < dev->num_tx_queues; i++) {
1888                         if (!remove_xps_queue(dev_maps, cpu, i))
1889                                 break;
1890                 }
1891                 if (i == dev->num_tx_queues)
1892                         active = true;
1893         }
1894 
1895         if (!active) {
1896                 RCU_INIT_POINTER(dev->xps_maps, NULL);
1897                 kfree_rcu(dev_maps, rcu);
1898         }
1899 
1900         for (i = index; i < dev->num_tx_queues; i++)
1901                 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
1902                                              NUMA_NO_NODE);
1903 
1904 out_no_maps:
1905         mutex_unlock(&xps_map_mutex);
1906 }
1907 
1908 static struct xps_map *expand_xps_map(struct xps_map *map,
1909                                       int cpu, u16 index)
1910 {
1911         struct xps_map *new_map;
1912         int alloc_len = XPS_MIN_MAP_ALLOC;
1913         int i, pos;
1914 
1915         for (pos = 0; map && pos < map->len; pos++) {
1916                 if (map->queues[pos] != index)
1917                         continue;
1918                 return map;
1919         }
1920 
1921         /* Need to add queue to this CPU's existing map */
1922         if (map) {
1923                 if (pos < map->alloc_len)
1924                         return map;
1925 
1926                 alloc_len = map->alloc_len * 2;
1927         }
1928 
1929         /* Need to allocate new map to store queue on this CPU's map */
1930         new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
1931                                cpu_to_node(cpu));
1932         if (!new_map)
1933                 return NULL;
1934 
1935         for (i = 0; i < pos; i++)
1936                 new_map->queues[i] = map->queues[i];
1937         new_map->alloc_len = alloc_len;
1938         new_map->len = pos;
1939 
1940         return new_map;
1941 }
1942 
1943 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
1944                         u16 index)
1945 {
1946         struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
1947         struct xps_map *map, *new_map;
1948         int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
1949         int cpu, numa_node_id = -2;
1950         bool active = false;
1951 
1952         mutex_lock(&xps_map_mutex);
1953 
1954         dev_maps = xmap_dereference(dev->xps_maps);
1955 
1956         /* allocate memory for queue storage */
1957         for_each_online_cpu(cpu) {
1958                 if (!cpumask_test_cpu(cpu, mask))
1959                         continue;
1960 
1961                 if (!new_dev_maps)
1962                         new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
1963                 if (!new_dev_maps) {
1964                         mutex_unlock(&xps_map_mutex);
1965                         return -ENOMEM;
1966                 }
1967 
1968                 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
1969                                  NULL;
1970 
1971                 map = expand_xps_map(map, cpu, index);
1972                 if (!map)
1973                         goto error;
1974 
1975                 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1976         }
1977 
1978         if (!new_dev_maps)
1979                 goto out_no_new_maps;
1980 
1981         for_each_possible_cpu(cpu) {
1982                 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
1983                         /* add queue to CPU maps */
1984                         int pos = 0;
1985 
1986                         map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1987                         while ((pos < map->len) && (map->queues[pos] != index))
1988                                 pos++;
1989 
1990                         if (pos == map->len)
1991                                 map->queues[map->len++] = index;
1992 #ifdef CONFIG_NUMA
1993                         if (numa_node_id == -2)
1994                                 numa_node_id = cpu_to_node(cpu);
1995                         else if (numa_node_id != cpu_to_node(cpu))
1996                                 numa_node_id = -1;
1997 #endif
1998                 } else if (dev_maps) {
1999                         /* fill in the new device map from the old device map */
2000                         map = xmap_dereference(dev_maps->cpu_map[cpu]);
2001                         RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
2002                 }
2003 
2004         }
2005 
2006         rcu_assign_pointer(dev->xps_maps, new_dev_maps);
2007 
2008         /* Cleanup old maps */
2009         if (dev_maps) {
2010                 for_each_possible_cpu(cpu) {
2011                         new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
2012                         map = xmap_dereference(dev_maps->cpu_map[cpu]);
2013                         if (map && map != new_map)
2014                                 kfree_rcu(map, rcu);
2015                 }
2016 
2017                 kfree_rcu(dev_maps, rcu);
2018         }
2019 
2020         dev_maps = new_dev_maps;
2021         active = true;
2022 
2023 out_no_new_maps:
2024         /* update Tx queue numa node */
2025         netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2026                                      (numa_node_id >= 0) ? numa_node_id :
2027                                      NUMA_NO_NODE);
2028 
2029         if (!dev_maps)
2030                 goto out_no_maps;
2031 
2032         /* removes queue from unused CPUs */
2033         for_each_possible_cpu(cpu) {
2034                 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu))
2035                         continue;
2036 
2037                 if (remove_xps_queue(dev_maps, cpu, index))
2038                         active = true;
2039         }
2040 
2041         /* free map if not active */
2042         if (!active) {
2043                 RCU_INIT_POINTER(dev->xps_maps, NULL);
2044                 kfree_rcu(dev_maps, rcu);
2045         }
2046 
2047 out_no_maps:
2048         mutex_unlock(&xps_map_mutex);
2049 
2050         return 0;
2051 error:
2052         /* remove any maps that we added */
2053         for_each_possible_cpu(cpu) {
2054                 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
2055                 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
2056                                  NULL;
2057                 if (new_map && new_map != map)
2058                         kfree(new_map);
2059         }
2060 
2061         mutex_unlock(&xps_map_mutex);
2062 
2063         kfree(new_dev_maps);
2064         return -ENOMEM;
2065 }
2066 EXPORT_SYMBOL(netif_set_xps_queue);
2067 
2068 #endif
2069 /*
2070  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2071  * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
2072  */
2073 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2074 {
2075         int rc;
2076 
2077         if (txq < 1 || txq > dev->num_tx_queues)
2078                 return -EINVAL;
2079 
2080         if (dev->reg_state == NETREG_REGISTERED ||
2081             dev->reg_state == NETREG_UNREGISTERING) {
2082                 ASSERT_RTNL();
2083 
2084                 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2085                                                   txq);
2086                 if (rc)
2087                         return rc;
2088 
2089                 if (dev->num_tc)
2090                         netif_setup_tc(dev, txq);
2091 
2092                 if (txq < dev->real_num_tx_queues) {
2093                         qdisc_reset_all_tx_gt(dev, txq);
2094 #ifdef CONFIG_XPS
2095                         netif_reset_xps_queues_gt(dev, txq);
2096 #endif
2097                 }
2098         }
2099 
2100         dev->real_num_tx_queues = txq;
2101         return 0;
2102 }
2103 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2104 
2105 #ifdef CONFIG_SYSFS
2106 /**
2107  *      netif_set_real_num_rx_queues - set actual number of RX queues used
2108  *      @dev: Network device
2109  *      @rxq: Actual number of RX queues
2110  *
2111  *      This must be called either with the rtnl_lock held or before
2112  *      registration of the net device.  Returns 0 on success, or a
2113  *      negative error code.  If called before registration, it always
2114  *      succeeds.
2115  */
2116 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2117 {
2118         int rc;
2119 
2120         if (rxq < 1 || rxq > dev->num_rx_queues)
2121                 return -EINVAL;
2122 
2123         if (dev->reg_state == NETREG_REGISTERED) {
2124                 ASSERT_RTNL();
2125 
2126                 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2127                                                   rxq);
2128                 if (rc)
2129                         return rc;
2130         }
2131 
2132         dev->real_num_rx_queues = rxq;
2133         return 0;
2134 }
2135 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2136 #endif
2137 
2138 /**
2139  * netif_get_num_default_rss_queues - default number of RSS queues
2140  *
2141  * This routine should set an upper limit on the number of RSS queues
2142  * used by default by multiqueue devices.
2143  */
2144 int netif_get_num_default_rss_queues(void)
2145 {
2146         return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
2147 }
2148 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
2149 
2150 static inline void __netif_reschedule(struct Qdisc *q)
2151 {
2152         struct softnet_data *sd;
2153         unsigned long flags;
2154 
2155         local_irq_save(flags);
2156         sd = &__get_cpu_var(softnet_data);
2157         q->next_sched = NULL;
2158         *sd->output_queue_tailp = q;
2159         sd->output_queue_tailp = &q->next_sched;
2160         raise_softirq_irqoff(NET_TX_SOFTIRQ);
2161         local_irq_restore(flags);
2162 }
2163 
2164 void __netif_schedule(struct Qdisc *q)
2165 {
2166         if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
2167                 __netif_reschedule(q);
2168 }
2169 EXPORT_SYMBOL(__netif_schedule);
2170 
2171 struct dev_kfree_skb_cb {
2172         enum skb_free_reason reason;
2173 };
2174 
2175 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
2176 {
2177         return (struct dev_kfree_skb_cb *)skb->cb;
2178 }
2179 
2180 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
2181 {
2182         unsigned long flags;
2183 
2184         if (likely(atomic_read(&skb->users) == 1)) {
2185                 smp_rmb();
2186                 atomic_set(&skb->users, 0);
2187         } else if (likely(!atomic_dec_and_test(&skb->users))) {
2188                 return;
2189         }
2190         get_kfree_skb_cb(skb)->reason = reason;
2191         local_irq_save(flags);
2192         skb->next = __this_cpu_read(softnet_data.completion_queue);
2193         __this_cpu_write(softnet_data.completion_queue, skb);
2194         raise_softirq_irqoff(NET_TX_SOFTIRQ);
2195         local_irq_restore(flags);
2196 }
2197 EXPORT_SYMBOL(__dev_kfree_skb_irq);
2198 
2199 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
2200 {
2201         if (in_irq() || irqs_disabled())
2202                 __dev_kfree_skb_irq(skb, reason);
2203         else
2204                 dev_kfree_skb(skb);
2205 }
2206 EXPORT_SYMBOL(__dev_kfree_skb_any);
2207 
2208 
2209 /**
2210  * netif_device_detach - mark device as removed
2211  * @dev: network device
2212  *
2213  * Mark device as removed from system and therefore no longer available.
2214  */
2215 void netif_device_detach(struct net_device *dev)
2216 {
2217         if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
2218             netif_running(dev)) {
2219                 netif_tx_stop_all_queues(dev);
2220         }
2221 }
2222 EXPORT_SYMBOL(netif_device_detach);
2223 
2224 /**
2225  * netif_device_attach - mark device as attached
2226  * @dev: network device
2227  *
2228  * Mark device as attached from system and restart if needed.
2229  */
2230 void netif_device_attach(struct net_device *dev)
2231 {
2232         if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
2233             netif_running(dev)) {
2234                 netif_tx_wake_all_queues(dev);
2235                 __netdev_watchdog_up(dev);
2236         }
2237 }
2238 EXPORT_SYMBOL(netif_device_attach);
2239 
2240 static void skb_warn_bad_offload(const struct sk_buff *skb)
2241 {
2242         static const netdev_features_t null_features = 0;
2243         struct net_device *dev = skb->dev;
2244         const char *driver = "";
2245 
2246         if (!net_ratelimit())
2247                 return;
2248 
2249         if (dev && dev->dev.parent)
2250                 driver = dev_driver_string(dev->dev.parent);
2251 
2252         WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
2253              "gso_type=%d ip_summed=%d\n",
2254              driver, dev ? &dev->features : &null_features,
2255              skb->sk ? &skb->sk->sk_route_caps : &null_features,
2256              skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
2257              skb_shinfo(skb)->gso_type, skb->ip_summed);
2258 }
2259 
2260 /*
2261  * Invalidate hardware checksum when packet is to be mangled, and
2262  * complete checksum manually on outgoing path.
2263  */
2264 int skb_checksum_help(struct sk_buff *skb)
2265 {
2266         __wsum csum;
2267         int ret = 0, offset;
2268 
2269         if (skb->ip_summed == CHECKSUM_COMPLETE)
2270                 goto out_set_summed;
2271 
2272         if (unlikely(skb_shinfo(skb)->gso_size)) {
2273                 skb_warn_bad_offload(skb);
2274                 return -EINVAL;
2275         }
2276 
2277         /* Before computing a checksum, we should make sure no frag could
2278          * be modified by an external entity : checksum could be wrong.
2279          */
2280         if (skb_has_shared_frag(skb)) {
2281                 ret = __skb_linearize(skb);
2282                 if (ret)
2283                         goto out;
2284         }
2285 
2286         offset = skb_checksum_start_offset(skb);
2287         BUG_ON(offset >= skb_headlen(skb));
2288         csum = skb_checksum(skb, offset, skb->len - offset, 0);
2289 
2290         offset += skb->csum_offset;
2291         BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
2292 
2293         if (skb_cloned(skb) &&
2294             !skb_clone_writable(skb, offset + sizeof(__sum16))) {
2295                 ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
2296                 if (ret)
2297                         goto out;
2298         }
2299 
2300         *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2301 out_set_summed:
2302         skb->ip_summed = CHECKSUM_NONE;
2303 out:
2304         return ret;
2305 }
2306 EXPORT_SYMBOL(skb_checksum_help);
2307 
2308 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
2309 {
2310         unsigned int vlan_depth = skb->mac_len;
2311         __be16 type = skb->protocol;
2312 
2313         /* Tunnel gso handlers can set protocol to ethernet. */
2314         if (type == htons(ETH_P_TEB)) {
2315                 struct ethhdr *eth;
2316 
2317                 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
2318                         return 0;
2319 
2320                 eth = (struct ethhdr *)skb_mac_header(skb);
2321                 type = eth->h_proto;
2322         }
2323 
2324         /* if skb->protocol is 802.1Q/AD then the header should already be
2325          * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
2326          * ETH_HLEN otherwise
2327          */
2328         if (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
2329                 if (vlan_depth) {
2330                         if (WARN_ON(vlan_depth < VLAN_HLEN))
2331                                 return 0;
2332                         vlan_depth -= VLAN_HLEN;
2333                 } else {
2334                         vlan_depth = ETH_HLEN;
2335                 }
2336                 do {
2337                         struct vlan_hdr *vh;
2338 
2339                         if (unlikely(!pskb_may_pull(skb,
2340                                                     vlan_depth + VLAN_HLEN)))
2341                                 return 0;
2342 
2343                         vh = (struct vlan_hdr *)(skb->data + vlan_depth);
2344                         type = vh->h_vlan_encapsulated_proto;
2345                         vlan_depth += VLAN_HLEN;
2346                 } while (type == htons(ETH_P_8021Q) ||
2347                          type == htons(ETH_P_8021AD));
2348         }
2349 
2350         *depth = vlan_depth;
2351 
2352         return type;
2353 }
2354 
2355 /**
2356  *      skb_mac_gso_segment - mac layer segmentation handler.
2357  *      @skb: buffer to segment
2358  *      @features: features for the output path (see dev->features)
2359  */
2360 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
2361                                     netdev_features_t features)
2362 {
2363         struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
2364         struct packet_offload *ptype;
2365         int vlan_depth = skb->mac_len;
2366         __be16 type = skb_network_protocol(skb, &vlan_depth);
2367 
2368         if (unlikely(!type))
2369                 return ERR_PTR(-EINVAL);
2370 
2371         __skb_pull(skb, vlan_depth);
2372 
2373         rcu_read_lock();
2374         list_for_each_entry_rcu(ptype, &offload_base, list) {
2375                 if (ptype->type == type && ptype->callbacks.gso_segment) {
2376                         if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2377                                 int err;
2378 
2379                                 err = ptype->callbacks.gso_send_check(skb);
2380                                 segs = ERR_PTR(err);
2381                                 if (err || skb_gso_ok(skb, features))
2382                                         break;
2383                                 __skb_push(skb, (skb->data -
2384                                                  skb_network_header(skb)));
2385                         }
2386                         segs = ptype->callbacks.gso_segment(skb, features);
2387                         break;
2388                 }
2389         }
2390         rcu_read_unlock();
2391 
2392         __skb_push(skb, skb->data - skb_mac_header(skb));
2393 
2394         return segs;
2395 }
2396 EXPORT_SYMBOL(skb_mac_gso_segment);
2397 
2398 
2399 /* openvswitch calls this on rx path, so we need a different check.
2400  */
2401 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
2402 {
2403         if (tx_path)
2404                 return skb->ip_summed != CHECKSUM_PARTIAL;
2405         else
2406                 return skb->ip_summed == CHECKSUM_NONE;
2407 }
2408 
2409 /**
2410  *      __skb_gso_segment - Perform segmentation on skb.
2411  *      @skb: buffer to segment
2412  *      @features: features for the output path (see dev->features)
2413  *      @tx_path: whether it is called in TX path
2414  *
2415  *      This function segments the given skb and returns a list of segments.
2416  *
2417  *      It may return NULL if the skb requires no segmentation.  This is
2418  *      only possible when GSO is used for verifying header integrity.
2419  */
2420 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
2421                                   netdev_features_t features, bool tx_path)
2422 {
2423         if (unlikely(skb_needs_check(skb, tx_path))) {
2424                 int err;
2425 
2426                 skb_warn_bad_offload(skb);
2427 
2428                 err = skb_cow_head(skb, 0);
2429                 if (err < 0)
2430                         return ERR_PTR(err);
2431         }
2432 
2433         SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2434         SKB_GSO_CB(skb)->encap_level = 0;
2435 
2436         skb_reset_mac_header(skb);
2437         skb_reset_mac_len(skb);
2438 
2439         return skb_mac_gso_segment(skb, features);
2440 }
2441 EXPORT_SYMBOL(__skb_gso_segment);
2442 
2443 /* Take action when hardware reception checksum errors are detected. */
2444 #ifdef CONFIG_BUG
2445 void netdev_rx_csum_fault(struct net_device *dev)
2446 {
2447         if (net_ratelimit()) {
2448                 pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2449                 dump_stack();
2450         }
2451 }
2452 EXPORT_SYMBOL(netdev_rx_csum_fault);
2453 #endif
2454 
2455 /* Actually, we should eliminate this check as soon as we know, that:
2456  * 1. IOMMU is present and allows to map all the memory.
2457  * 2. No high memory really exists on this machine.
2458  */
2459 
2460 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
2461 {
2462 #ifdef CONFIG_HIGHMEM
2463         int i;
2464         if (!(dev->features & NETIF_F_HIGHDMA)) {
2465                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2466                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2467                         if (PageHighMem(skb_frag_page(frag)))
2468                                 return 1;
2469                 }
2470         }
2471 
2472         if (PCI_DMA_BUS_IS_PHYS) {
2473                 struct device *pdev = dev->dev.parent;
2474 
2475                 if (!pdev)
2476                         return 0;
2477                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2478                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2479                         dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2480                         if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
2481                                 return 1;
2482                 }
2483         }
2484 #endif
2485         return 0;
2486 }
2487 
2488 struct dev_gso_cb {
2489         void (*destructor)(struct sk_buff *skb);
2490 };
2491 
2492 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
2493 
2494 static void dev_gso_skb_destructor(struct sk_buff *skb)
2495 {
2496         struct dev_gso_cb *cb;
2497 
2498         kfree_skb_list(skb->next);
2499         skb->next = NULL;
2500 
2501         cb = DEV_GSO_CB(skb);
2502         if (cb->destructor)
2503                 cb->destructor(skb);
2504 }
2505 
2506 /**
2507  *      dev_gso_segment - Perform emulated hardware segmentation on skb.
2508  *      @skb: buffer to segment
2509  *      @features: device features as applicable to this skb
2510  *
2511  *      This function segments the given skb and stores the list of segments
2512  *      in skb->next.
2513  */
2514 static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2515 {
2516         struct sk_buff *segs;
2517 
2518         segs = skb_gso_segment(skb, features);
2519 
2520         /* Verifying header integrity only. */
2521         if (!segs)
2522                 return 0;
2523 
2524         if (IS_ERR(segs))
2525                 return PTR_ERR(segs);
2526 
2527         skb->next = segs;
2528         DEV_GSO_CB(skb)->destructor = skb->destructor;
2529         skb->destructor = dev_gso_skb_destructor;
2530 
2531         return 0;
2532 }
2533 
2534 /* If MPLS offload request, verify we are testing hardware MPLS features
2535  * instead of standard features for the netdev.
2536  */
2537 #ifdef CONFIG_NET_MPLS_GSO
2538 static netdev_features_t net_mpls_features(struct sk_buff *skb,
2539                                            netdev_features_t features,
2540                                            __be16 type)
2541 {
2542         if (type == htons(ETH_P_MPLS_UC) || type == htons(ETH_P_MPLS_MC))
2543                 features &= skb->dev->mpls_features;
2544 
2545         return features;
2546 }
2547 #else
2548 static netdev_features_t net_mpls_features(struct sk_buff *skb,
2549                                            netdev_features_t features,
2550                                            __be16 type)
2551 {
2552         return features;
2553 }
2554 #endif
2555 
2556 static netdev_features_t harmonize_features(struct sk_buff *skb,
2557         netdev_features_t features)
2558 {
2559         int tmp;
2560         __be16 type;
2561 
2562         type = skb_network_protocol(skb, &tmp);
2563         features = net_mpls_features(skb, features, type);
2564 
2565         if (skb->ip_summed != CHECKSUM_NONE &&
2566             !can_checksum_protocol(features, type)) {
2567                 features &= ~NETIF_F_ALL_CSUM;
2568         } else if (illegal_highdma(skb->dev, skb)) {
2569                 features &= ~NETIF_F_SG;
2570         }
2571 
2572         return features;
2573 }
2574 
2575 netdev_features_t netif_skb_features(struct sk_buff *skb)
2576 {
2577         __be16 protocol = skb->protocol;
2578         netdev_features_t features = skb->dev->features;
2579 
2580         if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
2581                 features &= ~NETIF_F_GSO_MASK;
2582 
2583         if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
2584                 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
2585                 protocol = veh->h_vlan_encapsulated_proto;
2586         } else if (!vlan_tx_tag_present(skb)) {
2587                 return harmonize_features(skb, features);
2588         }
2589 
2590         features = netdev_intersect_features(features,
2591                                              skb->dev->vlan_features |
2592                                              NETIF_F_HW_VLAN_CTAG_TX |
2593                                              NETIF_F_HW_VLAN_STAG_TX);
2594 
2595         if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD))
2596                 features = netdev_intersect_features(features,
2597                                                      NETIF_F_SG |
2598                                                      NETIF_F_HIGHDMA |
2599                                                      NETIF_F_FRAGLIST |
2600                                                      NETIF_F_GEN_CSUM |
2601                                                      NETIF_F_HW_VLAN_CTAG_TX |
2602                                                      NETIF_F_HW_VLAN_STAG_TX);
2603 
2604         return harmonize_features(skb, features);
2605 }
2606 EXPORT_SYMBOL(netif_skb_features);
2607 
2608 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2609                         struct netdev_queue *txq)
2610 {
2611         const struct net_device_ops *ops = dev->netdev_ops;
2612         int rc = NETDEV_TX_OK;
2613         unsigned int skb_len;
2614 
2615         if (likely(!skb->next)) {
2616                 netdev_features_t features;
2617 
2618                 /*
2619                  * If device doesn't need skb->dst, release it right now while
2620                  * its hot in this cpu cache
2621                  */
2622                 if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2623                         skb_dst_drop(skb);
2624 
2625                 features = netif_skb_features(skb);
2626 
2627                 if (vlan_tx_tag_present(skb) &&
2628                     !vlan_hw_offload_capable(features, skb->vlan_proto)) {
2629                         skb = __vlan_put_tag(skb, skb->vlan_proto,
2630                                              vlan_tx_tag_get(skb));
2631                         if (unlikely(!skb))
2632                                 goto out;
2633 
2634                         skb->vlan_tci = 0;
2635                 }
2636 
2637                 /* If encapsulation offload request, verify we are testing
2638                  * hardware encapsulation features instead of standard
2639                  * features for the netdev
2640                  */
2641                 if (skb->encapsulation)
2642                         features &= dev->hw_enc_features;
2643 
2644                 if (netif_needs_gso(skb, features)) {
2645                         if (unlikely(dev_gso_segment(skb, features)))
2646                                 goto out_kfree_skb;
2647                         if (skb->next)
2648                                 goto gso;
2649                 } else {
2650                         if (skb_needs_linearize(skb, features) &&
2651                             __skb_linearize(skb))
2652                                 goto out_kfree_skb;
2653 
2654                         /* If packet is not checksummed and device does not
2655                          * support checksumming for this protocol, complete
2656                          * checksumming here.
2657                          */
2658                         if (skb->ip_summed == CHECKSUM_PARTIAL) {
2659                                 if (skb->encapsulation)
2660                                         skb_set_inner_transport_header(skb,
2661                                                 skb_checksum_start_offset(skb));
2662                                 else
2663                                         skb_set_transport_header(skb,
2664                                                 skb_checksum_start_offset(skb));
2665                                 if (!(features & NETIF_F_ALL_CSUM) &&
2666                                      skb_checksum_help(skb))
2667                                         goto out_kfree_skb;
2668                         }
2669                 }
2670 
2671                 if (!list_empty(&ptype_all))
2672                         dev_queue_xmit_nit(skb, dev);
2673 
2674                 skb_len = skb->len;
2675                 trace_net_dev_start_xmit(skb, dev);
2676                 rc = ops->ndo_start_xmit(skb, dev);
2677                 trace_net_dev_xmit(skb, rc, dev, skb_len);
2678                 if (rc == NETDEV_TX_OK)
2679                         txq_trans_update(txq);
2680                 return rc;
2681         }
2682 
2683 gso:
2684         do {
2685                 struct sk_buff *nskb = skb->next;
2686 
2687                 skb->next = nskb->next;
2688                 nskb->next = NULL;
2689 
2690                 if (!list_empty(&ptype_all))
2691                         dev_queue_xmit_nit(nskb, dev);
2692 
2693                 skb_len = nskb->len;
2694                 trace_net_dev_start_xmit(nskb, dev);
2695                 rc = ops->ndo_start_xmit(nskb, dev);
2696                 trace_net_dev_xmit(nskb, rc, dev, skb_len);
2697                 if (unlikely(rc != NETDEV_TX_OK)) {
2698                         if (rc & ~NETDEV_TX_MASK)
2699                                 goto out_kfree_gso_skb;
2700                         nskb->next = skb->next;
2701                         skb->next = nskb;
2702                         return rc;
2703                 }
2704                 txq_trans_update(txq);
2705                 if (unlikely(netif_xmit_stopped(txq) && skb->next))
2706                         return NETDEV_TX_BUSY;
2707         } while (skb->next);
2708 
2709 out_kfree_gso_skb:
2710         if (likely(skb->next == NULL)) {
2711                 skb->destructor = DEV_GSO_CB(skb)->destructor;
2712                 consume_skb(skb);
2713                 return rc;
2714         }
2715 out_kfree_skb:
2716         kfree_skb(skb);
2717 out:
2718         return rc;
2719 }
2720 EXPORT_SYMBOL_GPL(dev_hard_start_xmit);
2721 
2722 static void qdisc_pkt_len_init(struct sk_buff *skb)
2723 {
2724         const struct skb_shared_info *shinfo = skb_shinfo(skb);
2725 
2726         qdisc_skb_cb(skb)->pkt_len = skb->len;
2727 
2728         /* To get more precise estimation of bytes sent on wire,
2729          * we add to pkt_len the headers size of all segments
2730          */
2731         if (shinfo->gso_size)  {
2732                 unsigned int hdr_len;
2733                 u16 gso_segs = shinfo->gso_segs;
2734 
2735                 /* mac layer + network layer */
2736                 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
2737 
2738                 /* + transport layer */
2739                 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
2740                         hdr_len += tcp_hdrlen(skb);
2741                 else
2742                         hdr_len += sizeof(struct udphdr);
2743 
2744                 if (shinfo->gso_type & SKB_GSO_DODGY)
2745                         gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
2746                                                 shinfo->gso_size);
2747 
2748                 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
2749         }
2750 }
2751 
2752 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2753                                  struct net_device *dev,
2754                                  struct netdev_queue *txq)
2755 {
2756         spinlock_t *root_lock = qdisc_lock(q);
2757         bool contended;
2758         int rc;
2759 
2760         qdisc_pkt_len_init(skb);
2761         qdisc_calculate_pkt_len(skb, q);
2762         /*
2763          * Heuristic to force contended enqueues to serialize on a
2764          * separate lock before trying to get qdisc main lock.
2765          * This permits __QDISC___STATE_RUNNING owner to get the lock more
2766          * often and dequeue packets faster.
2767          */
2768         contended = qdisc_is_running(q);
2769         if (unlikely(contended))
2770                 spin_lock(&q->busylock);
2771 
2772         spin_lock(root_lock);
2773         if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2774                 kfree_skb(skb);
2775                 rc = NET_XMIT_DROP;
2776         } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2777                    qdisc_run_begin(q)) {
2778                 /*
2779                  * This is a work-conserving queue; there are no old skbs
2780                  * waiting to be sent out; and the qdisc is not running -
2781                  * xmit the skb directly.
2782                  */
2783                 if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2784                         skb_dst_force(skb);
2785 
2786                 qdisc_bstats_update(q, skb);
2787 
2788                 if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
2789                         if (unlikely(contended)) {
2790                                 spin_unlock(&q->busylock);
2791                                 contended = false;
2792                         }
2793                         __qdisc_run(q);
2794                 } else
2795                         qdisc_run_end(q);
2796 
2797                 rc = NET_XMIT_SUCCESS;
2798         } else {
2799                 skb_dst_force(skb);
2800                 rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2801                 if (qdisc_run_begin(q)) {
2802                         if (unlikely(contended)) {
2803                                 spin_unlock(&q->busylock);
2804                                 contended = false;
2805                         }
2806                         __qdisc_run(q);
2807                 }
2808         }
2809         spin_unlock(root_lock);
2810         if (unlikely(contended))
2811                 spin_unlock(&q->busylock);
2812         return rc;
2813 }
2814 
2815 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
2816 static void skb_update_prio(struct sk_buff *skb)
2817 {
2818         struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
2819 
2820         if (!skb->priority && skb->sk && map) {
2821                 unsigned int prioidx = skb->sk->sk_cgrp_prioidx;
2822 
2823                 if (prioidx < map->priomap_len)
2824                         skb->priority = map->priomap[prioidx];
2825         }
2826 }
2827 #else
2828 #define skb_update_prio(skb)
2829 #endif
2830 
2831 static DEFINE_PER_CPU(int, xmit_recursion);
2832 #define RECURSION_LIMIT 10
2833 
2834 /**
2835  *      dev_loopback_xmit - loop back @skb
2836  *      @skb: buffer to transmit
2837  */
2838 int dev_loopback_xmit(struct sk_buff *skb)
2839 {
2840         skb_reset_mac_header(skb);
2841         __skb_pull(skb, skb_network_offset(skb));
2842         skb->pkt_type = PACKET_LOOPBACK;
2843         skb->ip_summed = CHECKSUM_UNNECESSARY;
2844         WARN_ON(!skb_dst(skb));
2845         skb_dst_force(skb);
2846         netif_rx_ni(skb);
2847         return 0;
2848 }
2849 EXPORT_SYMBOL(dev_loopback_xmit);
2850 
2851 /**
2852  *      __dev_queue_xmit - transmit a buffer
2853  *      @skb: buffer to transmit
2854  *      @accel_priv: private data used for L2 forwarding offload
2855  *
2856  *      Queue a buffer for transmission to a network device. The caller must
2857  *      have set the device and priority and built the buffer before calling
2858  *      this function. The function can be called from an interrupt.
2859  *
2860  *      A negative errno code is returned on a failure. A success does not
2861  *      guarantee the frame will be transmitted as it may be dropped due
2862  *      to congestion or traffic shaping.
2863  *
2864  * -----------------------------------------------------------------------------------
2865  *      I notice this method can also return errors from the queue disciplines,
2866  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
2867  *      be positive.
2868  *
2869  *      Regardless of the return value, the skb is consumed, so it is currently
2870  *      difficult to retry a send to this method.  (You can bump the ref count
2871  *      before sending to hold a reference for retry if you are careful.)
2872  *
2873  *      When calling this method, interrupts MUST be enabled.  This is because
2874  *      the BH enable code must have IRQs enabled so that it will not deadlock.
2875  *          --BLG
2876  */
2877 static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
2878 {
2879         struct net_device *dev = skb->dev;
2880         struct netdev_queue *txq;
2881         struct Qdisc *q;
2882         int rc = -ENOMEM;
2883 
2884         skb_reset_mac_header(skb);
2885 
2886         if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
2887                 __skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED);
2888 
2889         /* Disable soft irqs for various locks below. Also
2890          * stops preemption for RCU.
2891          */
2892         rcu_read_lock_bh();
2893 
2894         skb_update_prio(skb);
2895 
2896         txq = netdev_pick_tx(dev, skb, accel_priv);
2897         q = rcu_dereference_bh(txq->qdisc);
2898 
2899 #ifdef CONFIG_NET_CLS_ACT
2900         skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2901 #endif
2902         trace_net_dev_queue(skb);
2903         if (q->enqueue) {
2904                 rc = __dev_xmit_skb(skb, q, dev, txq);
2905                 goto out;
2906         }
2907 
2908         /* The device has no queue. Common case for software devices:
2909            loopback, all the sorts of tunnels...
2910 
2911            Really, it is unlikely that netif_tx_lock protection is necessary
2912            here.  (f.e. loopback and IP tunnels are clean ignoring statistics
2913            counters.)
2914            However, it is possible, that they rely on protection
2915            made by us here.
2916 
2917            Check this and shot the lock. It is not prone from deadlocks.
2918            Either shot noqueue qdisc, it is even simpler 8)
2919          */
2920         if (dev->flags & IFF_UP) {
2921                 int cpu = smp_processor_id(); /* ok because BHs are off */
2922 
2923                 if (txq->xmit_lock_owner != cpu) {
2924 
2925                         if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
2926                                 goto recursion_alert;
2927 
2928                         HARD_TX_LOCK(dev, txq, cpu);
2929 
2930                         if (!netif_xmit_stopped(txq)) {
2931                                 __this_cpu_inc(xmit_recursion);
2932                                 rc = dev_hard_start_xmit(skb, dev, txq);
2933                                 __this_cpu_dec(xmit_recursion);
2934                                 if (dev_xmit_complete(rc)) {
2935                                         HARD_TX_UNLOCK(dev, txq);
2936                                         goto out;
2937                                 }
2938                         }
2939                         HARD_TX_UNLOCK(dev, txq);
2940                         net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
2941                                              dev->name);
2942                 } else {
2943                         /* Recursion is detected! It is possible,
2944                          * unfortunately
2945                          */
2946 recursion_alert:
2947                         net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
2948                                              dev->name);
2949                 }
2950         }
2951 
2952         rc = -ENETDOWN;
2953         rcu_read_unlock_bh();
2954 
2955         atomic_long_inc(&dev->tx_dropped);
2956         kfree_skb(skb);
2957         return rc;
2958 out:
2959         rcu_read_unlock_bh();
2960         return rc;
2961 }
2962 
2963 int dev_queue_xmit(struct sk_buff *skb)
2964 {
2965         return __dev_queue_xmit(skb, NULL);
2966 }
2967 EXPORT_SYMBOL(dev_queue_xmit);
2968 
2969 int dev_queue_xmit_accel(struct sk_buff *skb, void *accel_priv)
2970 {
2971         return __dev_queue_xmit(skb, accel_priv);
2972 }
2973 EXPORT_SYMBOL(dev_queue_xmit_accel);
2974 
2975 
2976 /*=======================================================================
2977                         Receiver routines
2978   =======================================================================*/
2979 
2980 int netdev_max_backlog __read_mostly = 1000;
2981 EXPORT_SYMBOL(netdev_max_backlog);
2982 
2983 int netdev_tstamp_prequeue __read_mostly = 1;
2984 int netdev_budget __read_mostly = 300;
2985 int weight_p __read_mostly = 64;            /* old backlog weight */
2986 
2987 /* Called with irq disabled */
2988 static inline void ____napi_schedule(struct softnet_data *sd,
2989                                      struct napi_struct *napi)
2990 {
2991         list_add_tail(&napi->poll_list, &sd->poll_list);
2992         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
2993 }
2994 
2995 #ifdef CONFIG_RPS
2996 
2997 /* One global table that all flow-based protocols share. */
2998 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2999 EXPORT_SYMBOL(rps_sock_flow_table);
3000 
3001 struct static_key rps_needed __read_mostly;
3002 
3003 static struct rps_dev_flow *
3004 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
3005             struct rps_dev_flow *rflow, u16 next_cpu)
3006 {
3007         if (next_cpu != RPS_NO_CPU) {
3008 #ifdef CONFIG_RFS_ACCEL
3009                 struct netdev_rx_queue *rxqueue;
3010                 struct rps_dev_flow_table *flow_table;
3011                 struct rps_dev_flow *old_rflow;
3012                 u32 flow_id;
3013                 u16 rxq_index;
3014                 int rc;
3015 
3016                 /* Should we steer this flow to a different hardware queue? */
3017                 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
3018                     !(dev->features & NETIF_F_NTUPLE))
3019                         goto out;
3020                 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
3021                 if (rxq_index == skb_get_rx_queue(skb))
3022                         goto out;
3023 
3024                 rxqueue = dev->_rx + rxq_index;
3025                 flow_table = rcu_dereference(rxqueue->rps_flow_table);
3026                 if (!flow_table)
3027                         goto out;
3028                 flow_id = skb_get_hash(skb) & flow_table->mask;
3029                 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
3030                                                         rxq_index, flow_id);
3031                 if (rc < 0)
3032                         goto out;
3033                 old_rflow = rflow;
3034                 rflow = &flow_table->flows[flow_id];
3035                 rflow->filter = rc;
3036                 if (old_rflow->filter == rflow->filter)
3037                         old_rflow->filter = RPS_NO_FILTER;
3038         out:
3039 #endif
3040                 rflow->last_qtail =
3041                         per_cpu(softnet_data, next_cpu).input_queue_head;
3042         }
3043 
3044         rflow->cpu = next_cpu;
3045         return rflow;
3046 }
3047 
3048 /*
3049  * get_rps_cpu is called from netif_receive_skb and returns the target
3050  * CPU from the RPS map of the receiving queue for a given skb.
3051  * rcu_read_lock must be held on entry.
3052  */
3053 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
3054                        struct rps_dev_flow **rflowp)
3055 {
3056         struct netdev_rx_queue *rxqueue;
3057         struct rps_map *map;
3058         struct rps_dev_flow_table *flow_table;
3059         struct rps_sock_flow_table *sock_flow_table;
3060         int cpu = -1;
3061         u16 tcpu;
3062         u32 hash;
3063 
3064         if (skb_rx_queue_recorded(skb)) {
3065                 u16 index = skb_get_rx_queue(skb);
3066                 if (unlikely(index >= dev->real_num_rx_queues)) {
3067                         WARN_ONCE(dev->real_num_rx_queues > 1,
3068                                   "%s received packet on queue %u, but number "
3069                                   "of RX queues is %u\n",
3070                                   dev->name, index, dev->real_num_rx_queues);
3071                         goto done;
3072                 }
3073                 rxqueue = dev->_rx + index;
3074         } else
3075                 rxqueue = dev->_rx;
3076 
3077         map = rcu_dereference(rxqueue->rps_map);
3078         if (map) {
3079                 if (map->len == 1 &&
3080                     !rcu_access_pointer(rxqueue->rps_flow_table)) {
3081                         tcpu = map->cpus[0];
3082                         if (cpu_online(tcpu))
3083                                 cpu = tcpu;
3084                         goto done;
3085                 }
3086         } else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
3087                 goto done;
3088         }
3089 
3090         skb_reset_network_header(skb);
3091         hash = skb_get_hash(skb);
3092         if (!hash)
3093                 goto done;
3094 
3095         flow_table = rcu_dereference(rxqueue->rps_flow_table);
3096         sock_flow_table = rcu_dereference(rps_sock_flow_table);
3097         if (flow_table && sock_flow_table) {
3098                 u16 next_cpu;
3099                 struct rps_dev_flow *rflow;
3100 
3101                 rflow = &flow_table->flows[hash & flow_table->mask];
3102                 tcpu = rflow->cpu;
3103 
3104                 next_cpu = sock_flow_table->ents[hash & sock_flow_table->mask];
3105 
3106                 /*
3107                  * If the desired CPU (where last recvmsg was done) is
3108                  * different from current CPU (one in the rx-queue flow
3109                  * table entry), switch if one of the following holds:
3110                  *   - Current CPU is unset (equal to RPS_NO_CPU).
3111                  *   - Current CPU is offline.
3112                  *   - The current CPU's queue tail has advanced beyond the
3113                  *     last packet that was enqueued using this table entry.
3114                  *     This guarantees that all previous packets for the flow
3115                  *     have been dequeued, thus preserving in order delivery.
3116                  */
3117                 if (unlikely(tcpu != next_cpu) &&
3118                     (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
3119                      ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
3120                       rflow->last_qtail)) >= 0)) {
3121                         tcpu = next_cpu;
3122                         rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3123                 }
3124 
3125                 if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
3126                         *rflowp = rflow;
3127                         cpu = tcpu;
3128                         goto done;
3129                 }
3130         }
3131 
3132         if (map) {
3133                 tcpu = map->cpus[((u64) hash * map->len) >> 32];
3134 
3135                 if (cpu_online(tcpu)) {
3136                         cpu = tcpu;
3137                         goto done;
3138                 }
3139         }
3140 
3141 done:
3142         return cpu;
3143 }
3144 
3145 #ifdef CONFIG_RFS_ACCEL
3146 
3147 /**
3148  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
3149  * @dev: Device on which the filter was set
3150  * @rxq_index: RX queue index
3151  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
3152  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
3153  *
3154  * Drivers that implement ndo_rx_flow_steer() should periodically call
3155  * this function for each installed filter and remove the filters for
3156  * which it returns %true.
3157  */
3158 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
3159                          u32 flow_id, u16 filter_id)
3160 {
3161         struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
3162         struct rps_dev_flow_table *flow_table;
3163         struct rps_dev_flow *rflow;
3164         bool expire = true;
3165         int cpu;
3166 
3167         rcu_read_lock();
3168         flow_table = rcu_dereference(rxqueue->rps_flow_table);
3169         if (flow_table && flow_id <= flow_table->mask) {
3170                 rflow = &flow_table->flows[flow_id];
3171                 cpu = ACCESS_ONCE(rflow->cpu);
3172                 if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
3173                     ((int)(per_cpu(softnet_data, cpu).input_queue_head -
3174                            rflow->last_qtail) <
3175                      (int)(10 * flow_table->mask)))
3176                         expire = false;
3177         }
3178         rcu_read_unlock();
3179         return expire;
3180 }
3181 EXPORT_SYMBOL(rps_may_expire_flow);
3182 
3183 #endif /* CONFIG_RFS_ACCEL */
3184 
3185 /* Called from hardirq (IPI) context */
3186 static void rps_trigger_softirq(void *data)
3187 {
3188         struct softnet_data *sd = data;
3189 
3190         ____napi_schedule(sd, &sd->backlog);
3191         sd->received_rps++;
3192 }
3193 
3194 #endif /* CONFIG_RPS */
3195 
3196 /*
3197  * Check if this softnet_data structure is another cpu one
3198  * If yes, queue it to our IPI list and return 1
3199  * If no, return 0
3200  */
3201 static int rps_ipi_queued(struct softnet_data *sd)
3202 {
3203 #ifdef CONFIG_RPS
3204         struct softnet_data *mysd = &__get_cpu_var(softnet_data);
3205 
3206         if (sd != mysd) {
3207                 sd->rps_ipi_next = mysd->rps_ipi_list;
3208                 mysd->rps_ipi_list = sd;
3209 
3210                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
3211                 return 1;
3212         }
3213 #endif /* CONFIG_RPS */
3214         return 0;
3215 }
3216 
3217 #ifdef CONFIG_NET_FLOW_LIMIT
3218 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
3219 #endif
3220 
3221 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
3222 {
3223 #ifdef CONFIG_NET_FLOW_LIMIT
3224         struct sd_flow_limit *fl;
3225         struct softnet_data *sd;
3226         unsigned int old_flow, new_flow;
3227 
3228         if (qlen < (netdev_max_backlog >> 1))
3229                 return false;
3230 
3231         sd = &__get_cpu_var(softnet_data);
3232 
3233         rcu_read_lock();
3234         fl = rcu_dereference(sd->flow_limit);
3235         if (fl) {
3236                 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
3237                 old_flow = fl->history[fl->history_head];
3238                 fl->history[fl->history_head] = new_flow;
3239 
3240                 fl->history_head++;
3241                 fl->history_head &= FLOW_LIMIT_HISTORY - 1;
3242 
3243                 if (likely(fl->buckets[old_flow]))
3244                         fl->buckets[old_flow]--;
3245 
3246                 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
3247                         fl->count++;
3248                         rcu_read_unlock();
3249                         return true;
3250                 }
3251         }
3252         rcu_read_unlock();
3253 #endif
3254         return false;
3255 }
3256 
3257 /*
3258  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
3259  * queue (may be a remote CPU queue).
3260  */
3261 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
3262                               unsigned int *qtail)
3263 {
3264         struct softnet_data *sd;
3265         unsigned long flags;
3266         unsigned int qlen;
3267 
3268         sd = &per_cpu(softnet_data, cpu);
3269 
3270         local_irq_save(flags);
3271 
3272         rps_lock(sd);
3273         qlen = skb_queue_len(&sd->input_pkt_queue);
3274         if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3275                 if (skb_queue_len(&sd->input_pkt_queue)) {
3276 enqueue:
3277                         __skb_queue_tail(&sd->input_pkt_queue, skb);
3278                         input_queue_tail_incr_save(sd, qtail);
3279                         rps_unlock(sd);
3280                         local_irq_restore(flags);
3281                         return NET_RX_SUCCESS;
3282                 }
3283 
3284                 /* Schedule NAPI for backlog device
3285                  * We can use non atomic operation since we own the queue lock
3286                  */
3287                 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
3288                         if (!rps_ipi_queued(sd))
3289                                 ____napi_schedule(sd, &sd->backlog);
3290                 }
3291                 goto enqueue;
3292         }
3293 
3294         sd->dropped++;
3295         rps_unlock(sd);
3296 
3297         local_irq_restore(flags);
3298 
3299         atomic_long_inc(&skb->dev->rx_dropped);
3300         kfree_skb(skb);
3301         return NET_RX_DROP;
3302 }
3303 
3304 static int netif_rx_internal(struct sk_buff *skb)
3305 {
3306         int ret;
3307 
3308         net_timestamp_check(netdev_tstamp_prequeue, skb);
3309 
3310         trace_netif_rx(skb);
3311 #ifdef CONFIG_RPS
3312         if (static_key_false(&rps_needed)) {
3313                 struct rps_dev_flow voidflow, *rflow = &voidflow;
3314                 int cpu;
3315 
3316                 preempt_disable();
3317                 rcu_read_lock();
3318 
3319                 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3320                 if (cpu < 0)
3321                         cpu = smp_processor_id();
3322 
3323                 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3324 
3325                 rcu_read_unlock();
3326                 preempt_enable();
3327         } else
3328 #endif
3329         {
3330                 unsigned int qtail;
3331                 ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
3332                 put_cpu();
3333         }
3334         return ret;
3335 }
3336 
3337 /**
3338  *      netif_rx        -       post buffer to the network code
3339  *      @skb: buffer to post
3340  *
3341  *      This function receives a packet from a device driver and queues it for
3342  *      the upper (protocol) levels to process.  It always succeeds. The buffer
3343  *      may be dropped during processing for congestion control or by the
3344  *      protocol layers.
3345  *
3346  *      return values:
3347  *      NET_RX_SUCCESS  (no congestion)
3348  *      NET_RX_DROP     (packet was dropped)
3349  *
3350  */
3351 
3352 int netif_rx(struct sk_buff *skb)
3353 {
3354         trace_netif_rx_entry(skb);
3355 
3356         return netif_rx_internal(skb);
3357 }
3358 EXPORT_SYMBOL(netif_rx);
3359 
3360 int netif_rx_ni(struct sk_buff *skb)
3361 {
3362         int err;
3363 
3364         trace_netif_rx_ni_entry(skb);
3365 
3366         preempt_disable();
3367         err = netif_rx_internal(skb);
3368         if (local_softirq_pending())
3369                 do_softirq();
3370         preempt_enable();
3371 
3372         return err;
3373 }
3374 EXPORT_SYMBOL(netif_rx_ni);
3375 
3376 static void net_tx_action(struct softirq_action *h)
3377 {
3378         struct softnet_data *sd = &__get_cpu_var(softnet_data);
3379 
3380         if (sd->completion_queue) {
3381                 struct sk_buff *clist;
3382 
3383                 local_irq_disable();
3384                 clist = sd->completion_queue;
3385                 sd->completion_queue = NULL;
3386                 local_irq_enable();
3387 
3388                 while (clist) {
3389                         struct sk_buff *skb = clist;
3390                         clist = clist->next;
3391 
3392                         WARN_ON(atomic_read(&skb->users));
3393                         if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
3394                                 trace_consume_skb(skb);
3395                         else
3396                                 trace_kfree_skb(skb, net_tx_action);
3397                         __kfree_skb(skb);
3398                 }
3399         }
3400 
3401         if (sd->output_queue) {
3402                 struct Qdisc *head;
3403 
3404                 local_irq_disable();
3405                 head = sd->output_queue;
3406                 sd->output_queue = NULL;
3407                 sd->output_queue_tailp = &sd->output_queue;
3408                 local_irq_enable();
3409 
3410                 while (head) {
3411                         struct Qdisc *q = head;
3412                         spinlock_t *root_lock;
3413 
3414                         head = head->next_sched;
3415 
3416                         root_lock = qdisc_lock(q);
3417                         if (spin_trylock(root_lock)) {
3418                                 smp_mb__before_atomic();
3419                                 clear_bit(__QDISC_STATE_SCHED,
3420                                           &q->state);
3421                                 qdisc_run(q);
3422                                 spin_unlock(root_lock);
3423                         } else {
3424                                 if (!test_bit(__QDISC_STATE_DEACTIVATED,
3425                                               &q->state)) {
3426                                         __netif_reschedule(q);
3427                                 } else {
3428                                         smp_mb__before_atomic();
3429                                         clear_bit(__QDISC_STATE_SCHED,
3430                                                   &q->state);
3431                                 }
3432                         }
3433                 }
3434         }
3435 }
3436 
3437 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
3438     (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3439 /* This hook is defined here for ATM LANE */
3440 int (*br_fdb_test_addr_hook)(struct net_device *dev,
3441                              unsigned char *addr) __read_mostly;
3442 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3443 #endif
3444 
3445 #ifdef CONFIG_NET_CLS_ACT
3446 /* TODO: Maybe we should just force sch_ingress to be compiled in
3447  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
3448  * a compare and 2 stores extra right now if we dont have it on
3449  * but have CONFIG_NET_CLS_ACT
3450  * NOTE: This doesn't stop any functionality; if you dont have
3451  * the ingress scheduler, you just can't add policies on ingress.
3452  *
3453  */
3454 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
3455 {
3456         struct net_device *dev = skb->dev;
3457         u32 ttl = G_TC_RTTL(skb->tc_verd);
3458         int result = TC_ACT_OK;
3459         struct Qdisc *q;
3460 
3461         if (unlikely(MAX_RED_LOOP < ttl++)) {
3462                 net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
3463                                      skb->skb_iif, dev->ifindex);
3464                 return TC_ACT_SHOT;
3465         }
3466 
3467         skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
3468         skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
3469 
3470         q = rxq->qdisc;
3471         if (q != &noop_qdisc) {
3472                 spin_lock(qdisc_lock(q));
3473                 if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
3474                         result = qdisc_enqueue_root(skb, q);
3475                 spin_unlock(qdisc_lock(q));
3476         }
3477 
3478         return result;
3479 }
3480 
3481 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
3482                                          struct packet_type **pt_prev,
3483                                          int *ret, struct net_device *orig_dev)
3484 {
3485         struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
3486 
3487         if (!rxq || rxq->qdisc == &noop_qdisc)
3488                 goto out;
3489 
3490         if (*pt_prev) {
3491                 *ret = deliver_skb(skb, *pt_prev, orig_dev);
3492                 *pt_prev = NULL;
3493         }
3494 
3495         switch (ing_filter(skb, rxq)) {
3496         case TC_ACT_SHOT:
3497         case TC_ACT_STOLEN:
3498                 kfree_skb(skb);
3499                 return NULL;
3500         }
3501 
3502 out:
3503         skb->tc_verd = 0;
3504         return skb;
3505 }
3506 #endif
3507 
3508 /**
3509  *      netdev_rx_handler_register - register receive handler
3510  *      @dev: device to register a handler for
3511  *      @rx_handler: receive handler to register
3512  *      @rx_handler_data: data pointer that is used by rx handler
3513  *
3514  *      Register a receive handler for a device. This handler will then be
3515  *      called from __netif_receive_skb. A negative errno code is returned
3516  *      on a failure.
3517  *
3518  *      The caller must hold the rtnl_mutex.
3519  *
3520  *      For a general description of rx_handler, see enum rx_handler_result.
3521  */
3522 int netdev_rx_handler_register(struct net_device *dev,
3523                                rx_handler_func_t *rx_handler,
3524                                void *rx_handler_data)
3525 {
3526         ASSERT_RTNL();
3527 
3528         if (dev->rx_handler)
3529                 return -EBUSY;
3530 
3531         /* Note: rx_handler_data must be set before rx_handler */
3532         rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3533         rcu_assign_pointer(dev->rx_handler, rx_handler);
3534 
3535         return 0;
3536 }
3537 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
3538 
3539 /**
3540  *      netdev_rx_handler_unregister - unregister receive handler
3541  *      @dev: device to unregister a handler from
3542  *
3543  *      Unregister a receive handler from a device.
3544  *
3545  *      The caller must hold the rtnl_mutex.
3546  */
3547 void netdev_rx_handler_unregister(struct net_device *dev)
3548 {
3549 
3550         ASSERT_RTNL();
3551         RCU_INIT_POINTER(dev->rx_handler, NULL);
3552         /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
3553          * section has a guarantee to see a non NULL rx_handler_data
3554          * as well.
3555          */
3556         synchronize_net();
3557         RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3558 }
3559 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
3560 
3561 /*
3562  * Limit the use of PFMEMALLOC reserves to those protocols that implement
3563  * the special handling of PFMEMALLOC skbs.
3564  */
3565 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
3566 {
3567         switch (skb->protocol) {
3568         case htons(ETH_P_ARP):
3569         case htons(ETH_P_IP):
3570         case htons(ETH_P_IPV6):
3571         case htons(ETH_P_8021Q):
3572         case htons(ETH_P_8021AD):
3573                 return true;
3574         default:
3575                 return false;
3576         }
3577 }
3578 
3579 static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
3580 {
3581         struct packet_type *ptype, *pt_prev;
3582         rx_handler_func_t *rx_handler;
3583         struct net_device *orig_dev;
3584         struct net_device *null_or_dev;
3585         bool deliver_exact = false;
3586         int ret = NET_RX_DROP;
3587         __be16 type;
3588 
3589         net_timestamp_check(!netdev_tstamp_prequeue, skb);
3590 
3591         trace_netif_receive_skb(skb);
3592 
3593         orig_dev = skb->dev;
3594 
3595         skb_reset_network_header(skb);
3596         if (!skb_transport_header_was_set(skb))
3597                 skb_reset_transport_header(skb);
3598         skb_reset_mac_len(skb);
3599 
3600         pt_prev = NULL;
3601 
3602         rcu_read_lock();
3603 
3604 another_round:
3605         skb->skb_iif = skb->dev->ifindex;
3606 
3607         __this_cpu_inc(softnet_data.processed);
3608 
3609         if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
3610             skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
3611                 skb = skb_vlan_untag(skb);
3612                 if (unlikely(!skb))
3613                         goto unlock;
3614         }
3615 
3616 #ifdef CONFIG_NET_CLS_ACT
3617         if (skb->tc_verd & TC_NCLS) {
3618                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
3619                 goto ncls;
3620         }
3621 #endif
3622 
3623         if (pfmemalloc)
3624                 goto skip_taps;
3625 
3626         list_for_each_entry_rcu(ptype, &ptype_all, list) {
3627                 if (!ptype->dev || ptype->dev == skb->dev) {
3628                         if (pt_prev)
3629                                 ret = deliver_skb(skb, pt_prev, orig_dev);
3630                         pt_prev = ptype;
3631                 }
3632         }
3633 
3634 skip_taps:
3635 #ifdef CONFIG_NET_CLS_ACT
3636         skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
3637         if (!skb)
3638                 goto unlock;
3639 ncls:
3640 #endif
3641 
3642         if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3643                 goto drop;
3644 
3645         if (vlan_tx_tag_present(skb)) {
3646                 if (pt_prev) {
3647                         ret = deliver_skb(skb, pt_prev, orig_dev);
3648                         pt_prev = NULL;
3649                 }
3650                 if (vlan_do_receive(&skb))
3651                         goto another_round;
3652                 else if (unlikely(!skb))
3653                         goto unlock;
3654         }
3655 
3656         rx_handler = rcu_dereference(skb->dev->rx_handler);
3657         if (rx_handler) {
3658                 if (pt_prev) {
3659                         ret = deliver_skb(skb, pt_prev, orig_dev);
3660                         pt_prev = NULL;
3661                 }
3662                 switch (rx_handler(&skb)) {
3663                 case RX_HANDLER_CONSUMED:
3664                         ret = NET_RX_SUCCESS;
3665                         goto unlock;
3666                 case RX_HANDLER_ANOTHER:
3667                         goto another_round;
3668                 case RX_HANDLER_EXACT:
3669                         deliver_exact = true;
3670                 case RX_HANDLER_PASS:
3671                         break;
3672                 default:
3673                         BUG();
3674                 }
3675         }
3676 
3677         if (unlikely(vlan_tx_tag_present(skb))) {
3678                 if (vlan_tx_tag_get_id(skb))
3679                         skb->pkt_type = PACKET_OTHERHOST;
3680                 /* Note: we might in the future use prio bits
3681                  * and set skb->priority like in vlan_do_receive()
3682                  * For the time being, just ignore Priority Code Point
3683                  */
3684                 skb->vlan_tci = 0;
3685         }
3686 
3687         /* deliver only exact match when indicated */
3688         null_or_dev = deliver_exact ? skb->dev : NULL;
3689 
3690         type = skb->protocol;
3691         list_for_each_entry_rcu(ptype,
3692                         &ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3693                 if (ptype->type == type &&
3694                     (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
3695                      ptype->dev == orig_dev)) {
3696                         if (pt_prev)
3697                                 ret = deliver_skb(skb, pt_prev, orig_dev);
3698                         pt_prev = ptype;
3699                 }
3700         }
3701 
3702         if (pt_prev) {
3703                 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3704                         goto drop;
3705                 else
3706                         ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
3707         } else {
3708 drop:
3709                 atomic_long_inc(&skb->dev->rx_dropped);
3710                 kfree_skb(skb);
3711                 /* Jamal, now you will not able to escape explaining
3712                  * me how you were going to use this. :-)
3713                  */
3714                 ret = NET_RX_DROP;
3715         }
3716 
3717 unlock:
3718         rcu_read_unlock();
3719         return ret;
3720 }
3721 
3722 static int __netif_receive_skb(struct sk_buff *skb)
3723 {
3724         int ret;
3725 
3726         if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
3727                 unsigned long pflags = current->flags;
3728 
3729                 /*
3730                  * PFMEMALLOC skbs are special, they should
3731                  * - be delivered to SOCK_MEMALLOC sockets only
3732                  * - stay away from userspace
3733                  * - have bounded memory usage
3734                  *
3735                  * Use PF_MEMALLOC as this saves us from propagating the allocation
3736                  * context down to all allocation sites.
3737                  */
3738                 current->flags |= PF_MEMALLOC;
3739                 ret = __netif_receive_skb_core(skb, true);
3740                 tsk_restore_flags(current, pflags, PF_MEMALLOC);
3741         } else
3742                 ret = __netif_receive_skb_core(skb, false);
3743 
3744         return ret;
3745 }
3746 
3747 static int netif_receive_skb_internal(struct sk_buff *skb)
3748 {
3749         net_timestamp_check(netdev_tstamp_prequeue, skb);
3750 
3751         if (skb_defer_rx_timestamp(skb))
3752                 return NET_RX_SUCCESS;
3753 
3754 #ifdef CONFIG_RPS
3755         if (static_key_false(&rps_needed)) {
3756                 struct rps_dev_flow voidflow, *rflow = &voidflow;
3757                 int cpu, ret;
3758 
3759                 rcu_read_lock();
3760 
3761                 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3762 
3763                 if (cpu >= 0) {
3764                         ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3765                         rcu_read_unlock();
3766                         return ret;
3767                 }
3768                 rcu_read_unlock();
3769         }
3770 #endif
3771         return __netif_receive_skb(skb);
3772 }
3773 
3774 /**
3775  *      netif_receive_skb - process receive buffer from network
3776  *      @skb: buffer to process
3777  *
3778  *      netif_receive_skb() is the main receive data processing function.
3779  *      It always succeeds. The buffer may be dropped during processing
3780  *      for congestion control or by the protocol layers.
3781  *
3782  *      This function may only be called from softirq context and interrupts
3783  *      should be enabled.
3784  *
3785  *      Return values (usually ignored):
3786  *      NET_RX_SUCCESS: no congestion
3787  *      NET_RX_DROP: packet was dropped
3788  */
3789 int netif_receive_skb(struct sk_buff *skb)
3790 {
3791         trace_netif_receive_skb_entry(skb);
3792 
3793         return netif_receive_skb_internal(skb);
3794 }
3795 EXPORT_SYMBOL(netif_receive_skb);
3796 
3797 /* Network device is going away, flush any packets still pending
3798  * Called with irqs disabled.
3799  */
3800 static void flush_backlog(void *arg)
3801 {
3802         struct net_device *dev = arg;
3803         struct softnet_data *sd = &__get_cpu_var(softnet_data);
3804         struct sk_buff *skb, *tmp;
3805 
3806         rps_lock(sd);
3807         skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3808                 if (skb->dev == dev) {
3809                         __skb_unlink(skb, &sd->input_pkt_queue);
3810                         kfree_skb(skb);
3811                         input_queue_head_incr(sd);
3812                 }
3813         }
3814         rps_unlock(sd);
3815 
3816         skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
3817                 if (skb->dev == dev) {
3818                         __skb_unlink(skb, &sd->process_queue);
3819                         kfree_skb(skb);
3820                         input_queue_head_incr(sd);
3821                 }
3822         }
3823 }
3824 
3825 static int napi_gro_complete(struct sk_buff *skb)
3826 {
3827         struct packet_offload *ptype;
3828         __be16 type = skb->protocol;
3829         struct list_head *head = &offload_base;
3830         int err = -ENOENT;
3831 
3832         BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
3833 
3834         if (NAPI_GRO_CB(skb)->count == 1) {
3835                 skb_shinfo(skb)->gso_size = 0;
3836                 goto out;
3837         }
3838 
3839         rcu_read_lock();
3840         list_for_each_entry_rcu(ptype, head, list) {
3841                 if (ptype->type != type || !ptype->callbacks.gro_complete)
3842                         continue;
3843 
3844                 err = ptype->callbacks.gro_complete(skb, 0);
3845                 break;
3846         }
3847         rcu_read_unlock();
3848 
3849         if (err) {
3850                 WARN_ON(&ptype->list == head);
3851                 kfree_skb(skb);
3852                 return NET_RX_SUCCESS;
3853         }
3854 
3855 out:
3856         return netif_receive_skb_internal(skb);
3857 }
3858 
3859 /* napi->gro_list contains packets ordered by age.
3860  * youngest packets at the head of it.
3861  * Complete skbs in reverse order to reduce latencies.
3862  */
3863 void napi_gro_flush(struct napi_struct *napi, bool flush_old)
3864 {
3865         struct sk_buff *skb, *prev = NULL;
3866 
3867         /* scan list and build reverse chain */
3868         for (skb = napi->gro_list; skb != NULL; skb = skb->next) {
3869                 skb->prev = prev;
3870                 prev = skb;
3871         }
3872 
3873         for (skb = prev; skb; skb = prev) {
3874                 skb->next = NULL;
3875 
3876                 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
3877                         return;
3878 
3879                 prev = skb->prev;
3880                 napi_gro_complete(skb);
3881                 napi->gro_count--;
3882         }
3883 
3884         napi->gro_list = NULL;
3885 }
3886 EXPORT_SYMBOL(napi_gro_flush);
3887 
3888 static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb)
3889 {
3890         struct sk_buff *p;
3891         unsigned int maclen = skb->dev->hard_header_len;
3892         u32 hash = skb_get_hash_raw(skb);
3893 
3894         for (p = napi->gro_list; p; p = p->next) {
3895                 unsigned long diffs;
3896 
3897                 NAPI_GRO_CB(p)->flush = 0;
3898 
3899                 if (hash != skb_get_hash_raw(p)) {
3900                         NAPI_GRO_CB(p)->same_flow = 0;
3901                         continue;
3902                 }
3903 
3904                 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
3905                 diffs |= p->vlan_tci ^ skb->vlan_tci;
3906                 if (maclen == ETH_HLEN)
3907                         diffs |= compare_ether_header(skb_mac_header(p),
3908                                                       skb_mac_header(skb));
3909                 else if (!diffs)
3910                         diffs = memcmp(skb_mac_header(p),
3911                                        skb_mac_header(skb),
3912                                        maclen);
3913                 NAPI_GRO_CB(p)->same_flow = !diffs;
3914         }
3915 }
3916 
3917 static void skb_gro_reset_offset(struct sk_buff *skb)
3918 {
3919         const struct skb_shared_info *pinfo = skb_shinfo(skb);
3920         const skb_frag_t *frag0 = &pinfo->frags[0];
3921 
3922         NAPI_GRO_CB(skb)->data_offset = 0;
3923         NAPI_GRO_CB(skb)->frag0 = NULL;
3924         NAPI_GRO_CB(skb)->frag0_len = 0;
3925 
3926         if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
3927             pinfo->nr_frags &&
3928             !PageHighMem(skb_frag_page(frag0))) {
3929                 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
3930                 NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0);
3931         }
3932 }
3933 
3934 static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
3935 {
3936         struct skb_shared_info *pinfo = skb_shinfo(skb);
3937 
3938         BUG_ON(skb->end - skb->tail < grow);
3939 
3940         memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3941 
3942         skb->data_len -= grow;
3943         skb->tail += grow;
3944 
3945         pinfo->frags[0].page_offset += grow;
3946         skb_frag_size_sub(&pinfo->frags[0], grow);
3947 
3948         if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
3949                 skb_frag_unref(skb, 0);
3950                 memmove(pinfo->frags, pinfo->frags + 1,
3951                         --pinfo->nr_frags * sizeof(pinfo->frags[0]));
3952         }
3953 }
3954 
3955 static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3956 {
3957         struct sk_buff **pp = NULL;
3958         struct packet_offload *ptype;
3959         __be16 type = skb->protocol;
3960         struct list_head *head = &offload_base;
3961         int same_flow;
3962         enum gro_result ret;
3963         int grow;
3964 
3965         if (!(skb->dev->features & NETIF_F_GRO))
3966                 goto normal;
3967 
3968         if (skb_is_gso(skb) || skb_has_frag_list(skb))
3969                 goto normal;
3970 
3971         gro_list_prepare(napi, skb);
3972         NAPI_GRO_CB(skb)->csum = skb->csum; /* Needed for CHECKSUM_COMPLETE */
3973 
3974         rcu_read_lock();
3975         list_for_each_entry_rcu(ptype, head, list) {
3976                 if (ptype->type != type || !ptype->callbacks.gro_receive)
3977                         continue;
3978 
3979                 skb_set_network_header(skb, skb_gro_offset(skb));
3980                 skb_reset_mac_len(skb);
3981                 NAPI_GRO_CB(skb)->same_flow = 0;
3982                 NAPI_GRO_CB(skb)->flush = 0;
3983                 NAPI_GRO_CB(skb)->free = 0;
3984                 NAPI_GRO_CB(skb)->udp_mark = 0;
3985 
3986                 pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3987                 break;
3988         }
3989         rcu_read_unlock();
3990 
3991         if (&ptype->list == head)
3992                 goto normal;
3993 
3994         same_flow = NAPI_GRO_CB(skb)->same_flow;
3995         ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3996 
3997         if (pp) {
3998                 struct sk_buff *nskb = *pp;
3999 
4000                 *pp = nskb->next;
4001                 nskb->next = NULL;
4002                 napi_gro_complete(nskb);
4003                 napi->gro_count--;
4004         }
4005 
4006         if (same_flow)
4007                 goto ok;
4008 
4009         if (NAPI_GRO_CB(skb)->flush)
4010                 goto normal;
4011 
4012         if (unlikely(napi->gro_count >= MAX_GRO_SKBS)) {
4013                 struct sk_buff *nskb = napi->gro_list;
4014 
4015                 /* locate the end of the list to select the 'oldest' flow */
4016                 while (nskb->next) {
4017                         pp = &nskb->next;
4018                         nskb = *pp;
4019                 }
4020                 *pp = NULL;
4021                 nskb->next = NULL;
4022                 napi_gro_complete(nskb);
4023         } else {
4024                 napi->gro_count++;
4025         }
4026         NAPI_GRO_CB(skb)->count = 1;
4027         NAPI_GRO_CB(skb)->age = jiffies;
4028         NAPI_GRO_CB(skb)->last = skb;
4029         skb_shinfo(skb)->gso_size = skb_gro_len(skb);
4030         skb->next = napi->gro_list;
4031         napi->gro_list = skb;
4032         ret = GRO_HELD;
4033 
4034 pull:
4035         grow = skb_gro_offset(skb) - skb_headlen(skb);
4036         if (grow > 0)
4037                 gro_pull_from_frag0(skb, grow);
4038 ok:
4039         return ret;
4040 
4041 normal:
4042         ret = GRO_NORMAL;
4043         goto pull;
4044 }
4045 
4046 struct packet_offload *gro_find_receive_by_type(__be16 type)
4047 {
4048         struct list_head *offload_head = &offload_base;
4049         struct packet_offload *ptype;
4050 
4051         list_for_each_entry_rcu(ptype, offload_head, list) {
4052                 if (ptype->type != type || !ptype->callbacks.gro_receive)
4053                         continue;
4054                 return ptype;
4055         }
4056         return NULL;
4057 }
4058 EXPORT_SYMBOL(gro_find_receive_by_type);
4059 
4060 struct packet_offload *gro_find_complete_by_type(__be16 type)
4061 {
4062         struct list_head *offload_head = &offload_base;
4063         struct packet_offload *ptype;
4064 
4065         list_for_each_entry_rcu(ptype, offload_head, list) {
4066                 if (ptype->type != type || !ptype->callbacks.gro_complete)
4067                         continue;
4068                 return ptype;
4069         }
4070         return NULL;
4071 }
4072 EXPORT_SYMBOL(gro_find_complete_by_type);
4073 
4074 static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
4075 {
4076         switch (ret) {
4077         case GRO_NORMAL:
4078                 if (netif_receive_skb_internal(skb))
4079                         ret = GRO_DROP;
4080                 break;
4081 
4082         case GRO_DROP:
4083                 kfree_skb(skb);
4084                 break;
4085 
4086         case GRO_MERGED_FREE:
4087                 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
4088                         kmem_cache_free(skbuff_head_cache, skb);
4089                 else
4090                         __kfree_skb(skb);
4091                 break;
4092 
4093         case GRO_HELD:
4094         case GRO_MERGED:
4095                 break;
4096         }
4097 
4098         return ret;
4099 }
4100 
4101 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
4102 {
4103         trace_napi_gro_receive_entry(skb);
4104 
4105         skb_gro_reset_offset(skb);
4106 
4107         return napi_skb_finish(dev_gro_receive(napi, skb), skb);
4108 }
4109 EXPORT_SYMBOL(napi_gro_receive);
4110 
4111 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
4112 {
4113         __skb_pull(skb, skb_headlen(skb));
4114         /* restore the reserve we had after netdev_alloc_skb_ip_align() */
4115         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
4116         skb->vlan_tci = 0;
4117         skb->dev = napi->dev;
4118         skb->skb_iif = 0;
4119         skb->encapsulation = 0;
4120         skb_shinfo(skb)->gso_type = 0;
4121         skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
4122 
4123         napi->skb = skb;
4124 }
4125 
4126 struct sk_buff *napi_get_frags(struct napi_struct *napi)
4127 {
4128         struct sk_buff *skb = napi->skb;
4129 
4130         if (!skb) {
4131                 skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
4132                 napi->skb = skb;
4133         }
4134         return skb;
4135 }
4136 EXPORT_SYMBOL(napi_get_frags);
4137 
4138 static gro_result_t napi_frags_finish(struct napi_struct *napi,
4139                                       struct sk_buff *skb,
4140                                       gro_result_t ret)
4141 {
4142         switch (ret) {
4143         case GRO_NORMAL:
4144         case GRO_HELD:
4145                 __skb_push(skb, ETH_HLEN);
4146                 skb->protocol = eth_type_trans(skb, skb->dev);
4147                 if (ret == GRO_NORMAL && netif_receive_skb_internal(skb))
4148                         ret = GRO_DROP;
4149                 break;
4150 
4151         case GRO_DROP:
4152         case GRO_MERGED_FREE:
4153                 napi_reuse_skb(napi, skb);
4154                 break;
4155 
4156         case GRO_MERGED:
4157                 break;
4158         }
4159 
4160         return ret;
4161 }
4162 
4163 /* Upper GRO stack assumes network header starts at gro_offset=0
4164  * Drivers could call both napi_gro_frags() and napi_gro_receive()
4165  * We copy ethernet header into skb->data to have a common layout.
4166  */
4167 static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
4168 {
4169         struct sk_buff *skb = napi->skb;
4170         const struct ethhdr *eth;
4171         unsigned int hlen = sizeof(*eth);
4172 
4173         napi->skb = NULL;
4174 
4175         skb_reset_mac_header(skb);
4176         skb_gro_reset_offset(skb);
4177 
4178         eth = skb_gro_header_fast(skb, 0);
4179         if (unlikely(skb_gro_header_hard(skb, hlen))) {
4180                 eth = skb_gro_header_slow(skb, hlen, 0);
4181                 if (unlikely(!eth)) {
4182                         napi_reuse_skb(napi, skb);
4183                         return NULL;
4184                 }
4185         } else {
4186                 gro_pull_from_frag0(skb, hlen);
4187                 NAPI_GRO_CB(skb)->frag0 += hlen;
4188                 NAPI_GRO_CB(skb)->frag0_len -= hlen;
4189         }
4190         __skb_pull(skb, hlen);
4191 
4192         /*
4193          * This works because the only protocols we care about don't require
4194          * special handling.
4195          * We'll fix it up properly in napi_frags_finish()
4196          */
4197         skb->protocol = eth->h_proto;
4198 
4199         return skb;
4200 }
4201 
4202 gro_result_t napi_gro_frags(struct napi_struct *napi)
4203 {
4204         struct sk_buff *skb = napi_frags_skb(napi);
4205 
4206         if (!skb)
4207                 return GRO_DROP;
4208 
4209         trace_napi_gro_frags_entry(skb);
4210 
4211         return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
4212 }
4213 EXPORT_SYMBOL(napi_gro_frags);
4214 
4215 /*
4216  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
4217  * Note: called with local irq disabled, but exits with local irq enabled.
4218  */
4219 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
4220 {
4221 #ifdef CONFIG_RPS
4222         struct softnet_data *remsd = sd->rps_ipi_list;
4223 
4224         if (remsd) {
4225                 sd->rps_ipi_list = NULL;
4226 
4227                 local_irq_enable();
4228 
4229                 /* Send pending IPI's to kick RPS processing on remote cpus. */
4230                 while (remsd) {
4231                         struct softnet_data *next = remsd->rps_ipi_next;
4232 
4233                         if (cpu_online(remsd->cpu))
4234                                 smp_call_function_single_async(remsd->cpu,
4235                                                            &remsd->csd);
4236                         remsd = next;
4237                 }
4238         } else
4239 #endif
4240                 local_irq_enable();
4241 }
4242 
4243 static int process_backlog(struct napi_struct *napi, int quota)
4244 {
4245         int work = 0;
4246         struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
4247 
4248 #ifdef CONFIG_RPS
4249         /* Check if we have pending ipi, its better to send them now,
4250          * not waiting net_rx_action() end.
4251          */
4252         if (sd->rps_ipi_list) {
4253                 local_irq_disable();
4254                 net_rps_action_and_irq_enable(sd);
4255         }
4256 #endif
4257         napi->weight = weight_p;
4258         local_irq_disable();
4259         while (1) {
4260                 struct sk_buff *skb;
4261 
4262                 while ((skb = __skb_dequeue(&sd->process_queue))) {
4263                         local_irq_enable();
4264                         __netif_receive_skb(skb);
4265                         local_irq_disable();
4266                         input_queue_head_incr(sd);
4267                         if (++work >= quota) {
4268                                 local_irq_enable();
4269                                 return work;
4270                         }
4271                 }
4272 
4273                 rps_lock(sd);
4274                 if (skb_queue_empty(&sd->input_pkt_queue)) {
4275                         /*
4276                          * Inline a custom version of __napi_complete().
4277                          * only current cpu owns and manipulates this napi,
4278                          * and NAPI_STATE_SCHED is the only possible flag set
4279                          * on backlog.
4280                          * We can use a plain write instead of clear_bit(),
4281                          * and we dont need an smp_mb() memory barrier.
4282                          */
4283                         list_del(&napi->poll_list);
4284                         napi->state = 0;
4285                         rps_unlock(sd);
4286 
4287                         break;
4288                 }
4289 
4290                 skb_queue_splice_tail_init(&sd->input_pkt_queue,
4291                                            &sd->process_queue);
4292                 rps_unlock(sd);
4293         }
4294         local_irq_enable();
4295 
4296         return work;
4297 }
4298 
4299 /**
4300  * __napi_schedule - schedule for receive
4301  * @n: entry to schedule
4302  *
4303  * The entry's receive function will be scheduled to run
4304  */
4305 void __napi_schedule(struct napi_struct *n)
4306 {
4307         unsigned long flags;
4308 
4309         local_irq_save(flags);
4310         ____napi_schedule(&__get_cpu_var(softnet_data), n);
4311         local_irq_restore(flags);
4312 }
4313 EXPORT_SYMBOL(__napi_schedule);
4314 
4315 void __napi_complete(struct napi_struct *n)
4316 {
4317         BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
4318         BUG_ON(n->gro_list);
4319 
4320         list_del(&n->poll_list);
4321         smp_mb__before_atomic();
4322         clear_bit(NAPI_STATE_SCHED, &n->state);
4323 }
4324 EXPORT_SYMBOL(__napi_complete);
4325 
4326 void napi_complete(struct napi_struct *n)
4327 {
4328         unsigned long flags;
4329 
4330         /*
4331          * don't let napi dequeue from the cpu poll list
4332          * just in case its running on a different cpu
4333          */
4334         if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
4335                 return;
4336 
4337         napi_gro_flush(n, false);
4338         local_irq_save(flags);
4339         __napi_complete(n);
4340         local_irq_restore(flags);
4341 }
4342 EXPORT_SYMBOL(napi_complete);
4343 
4344 /* must be called under rcu_read_lock(), as we dont take a reference */
4345 struct napi_struct *napi_by_id(unsigned int napi_id)
4346 {
4347         unsigned int hash = napi_id % HASH_SIZE(napi_hash);
4348         struct napi_struct *napi;
4349 
4350         hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
4351                 if (napi->napi_id == napi_id)
4352                         return napi;
4353 
4354         return NULL;
4355 }
4356 EXPORT_SYMBOL_GPL(napi_by_id);
4357 
4358 void napi_hash_add(struct napi_struct *napi)
4359 {
4360         if (!test_and_set_bit(NAPI_STATE_HASHED, &napi->state)) {
4361 
4362                 spin_lock(&napi_hash_lock);
4363 
4364                 /* 0 is not a valid id, we also skip an id that is taken
4365                  * we expect both events to be extremely rare
4366                  */
4367                 napi->napi_id = 0;
4368                 while (!napi->napi_id) {
4369                         napi->napi_id = ++napi_gen_id;
4370                         if (napi_by_id(napi->napi_id))
4371                                 napi->napi_id = 0;
4372                 }
4373 
4374                 hlist_add_head_rcu(&napi->napi_hash_node,
4375                         &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
4376 
4377                 spin_unlock(&napi_hash_lock);
4378         }
4379 }
4380 EXPORT_SYMBOL_GPL(napi_hash_add);
4381 
4382 /* Warning : caller is responsible to make sure rcu grace period
4383  * is respected before freeing memory containing @napi
4384  */
4385 void napi_hash_del(struct napi_struct *napi)
4386 {
4387         spin_lock(&napi_hash_lock);
4388 
4389         if (test_and_clear_bit(NAPI_STATE_HASHED, &napi->state))
4390                 hlist_del_rcu(&napi->napi_hash_node);
4391 
4392         spin_unlock(&napi_hash_lock);
4393 }
4394 EXPORT_SYMBOL_GPL(napi_hash_del);
4395 
4396 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
4397                     int (*poll)(struct napi_struct *, int), int weight)
4398 {
4399         INIT_LIST_HEAD(&napi->poll_list);
4400         napi->gro_count = 0;
4401         napi->gro_list = NULL;
4402         napi->skb = NULL;
4403         napi->poll = poll;
4404         if (weight > NAPI_POLL_WEIGHT)
4405                 pr_err_once("netif_napi_add() called with weight %d on device %s\n",
4406                             weight, dev->name);
4407         napi->weight = weight;
4408         list_add(&napi->dev_list, &dev->napi_list);
4409         napi->dev = dev;
4410 #ifdef CONFIG_NETPOLL
4411         spin_lock_init(&napi->poll_lock);
4412         napi->poll_owner = -1;
4413 #endif
4414         set_bit(NAPI_STATE_SCHED, &napi->state);
4415 }
4416 EXPORT_SYMBOL(netif_napi_add);
4417 
4418 void netif_napi_del(struct napi_struct *napi)
4419 {
4420         list_del_init(&napi->dev_list);
4421         napi_free_frags(napi);
4422 
4423         kfree_skb_list(napi->gro_list);
4424         napi->gro_list = NULL;
4425         napi->gro_count = 0;
4426 }
4427 EXPORT_SYMBOL(netif_napi_del);
4428 
4429 static void net_rx_action(struct softirq_action *h)
4430 {
4431         struct softnet_data *sd = &__get_cpu_var(softnet_data);
4432         unsigned long time_limit = jiffies + 2;
4433         int budget = netdev_budget;
4434         void *have;
4435 
4436         local_irq_disable();
4437 
4438         while (!list_empty(&sd->poll_list)) {
4439                 struct napi_struct *n;
4440                 int work, weight;
4441 
4442                 /* If softirq window is exhuasted then punt.
4443                  * Allow this to run for 2 jiffies since which will allow
4444                  * an average latency of 1.5/HZ.
4445                  */
4446                 if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
4447                         goto softnet_break;
4448 
4449                 local_irq_enable();
4450 
4451                 /* Even though interrupts have been re-enabled, this
4452                  * access is safe because interrupts can only add new
4453                  * entries to the tail of this list, and only ->poll()
4454                  * calls can remove this head entry from the list.
4455                  */
4456                 n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
4457 
4458                 have = netpoll_poll_lock(n);
4459 
4460                 weight = n->weight;
4461 
4462                 /* This NAPI_STATE_SCHED test is for avoiding a race
4463                  * with netpoll's poll_napi().  Only the entity which
4464                  * obtains the lock and sees NAPI_STATE_SCHED set will
4465                  * actually make the ->poll() call.  Therefore we avoid
4466                  * accidentally calling ->poll() when NAPI is not scheduled.
4467                  */
4468                 work = 0;
4469                 if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4470                         work = n->poll(n, weight);
4471                         trace_napi_poll(n);
4472                 }
4473 
4474                 WARN_ON_ONCE(work > weight);
4475 
4476                 budget -= work;
4477 
4478                 local_irq_disable();
4479 
4480                 /* Drivers must not modify the NAPI state if they
4481                  * consume the entire weight.  In such cases this code
4482                  * still "owns" the NAPI instance and therefore can
4483                  * move the instance around on the list at-will.
4484                  */
4485                 if (unlikely(work == weight)) {
4486                         if (unlikely(napi_disable_pending(n))) {
4487                                 local_irq_enable();
4488                                 napi_complete(n);
4489                                 local_irq_disable();
4490                         } else {
4491                                 if (n->gro_list) {
4492                                         /* flush too old packets
4493                                          * If HZ < 1000, flush all packets.
4494                                          */
4495                                         local_irq_enable();
4496                                         napi_gro_flush(n, HZ >= 1000);
4497                                         local_irq_disable();
4498                                 }
4499                                 list_move_tail(&n->poll_list, &sd->poll_list);
4500                         }
4501                 }
4502 
4503                 netpoll_poll_unlock(have);
4504         }
4505 out:
4506         net_rps_action_and_irq_enable(sd);
4507 
4508 #ifdef CONFIG_NET_DMA
4509         /*
4510          * There may not be any more sk_buffs coming right now, so push
4511          * any pending DMA copies to hardware
4512          */
4513         dma_issue_pending_all();
4514 #endif
4515 
4516         return;
4517 
4518 softnet_break:
4519         sd->time_squeeze++;
4520         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4521         goto out;
4522 }
4523 
4524 struct netdev_adjacent {
4525         struct net_device *dev;
4526 
4527         /* upper master flag, there can only be one master device per list */
4528         bool master;
4529 
4530         /* counter for the number of times this device was added to us */
4531         u16 ref_nr;
4532 
4533         /* private field for the users */
4534         void *private;
4535 
4536         struct list_head list;
4537         struct rcu_head rcu;
4538 };
4539 
4540 static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev,
4541                                                  struct net_device *adj_dev,
4542                                                  struct list_head *adj_list)
4543 {
4544         struct netdev_adjacent *adj;
4545 
4546         list_for_each_entry(adj, adj_list, list) {
4547                 if (adj->dev == adj_dev)
4548                         return adj;
4549         }
4550         return NULL;
4551 }
4552 
4553 /**
4554  * netdev_has_upper_dev - Check if device is linked to an upper device
4555  * @dev: device
4556  * @upper_dev: upper device to check
4557  *
4558  * Find out if a device is linked to specified upper device and return true
4559  * in case it is. Note that this checks only immediate upper device,
4560  * not through a complete stack of devices. The caller must hold the RTNL lock.
4561  */
4562 bool netdev_has_upper_dev(struct net_device *dev,
4563                           struct net_device *upper_dev)
4564 {
4565         ASSERT_RTNL();
4566 
4567         return __netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper);
4568 }
4569 EXPORT_SYMBOL(netdev_has_upper_dev);
4570 
4571 /**
4572  * netdev_has_any_upper_dev - Check if device is linked to some device
4573  * @dev: device
4574  *
4575  * Find out if a device is linked to an upper device and return true in case
4576  * it is. The caller must hold the RTNL lock.
4577  */
4578 static bool netdev_has_any_upper_dev(struct net_device *dev)
4579 {
4580         ASSERT_RTNL();
4581 
4582         return !list_empty(&dev->all_adj_list.upper);
4583 }
4584 
4585 /**
4586  * netdev_master_upper_dev_get - Get master upper device
4587  * @dev: device
4588  *
4589  * Find a master upper device and return pointer to it or NULL in case
4590  * it's not there. The caller must hold the RTNL lock.
4591  */
4592 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
4593 {
4594         struct netdev_adjacent *upper;
4595 
4596         ASSERT_RTNL();
4597 
4598         if (list_empty(&dev->adj_list.upper))
4599                 return NULL;
4600 
4601         upper = list_first_entry(&dev->adj_list.upper,
4602                                  struct netdev_adjacent, list);
4603         if (likely(upper->master))
4604                 return upper->dev;
4605         return NULL;
4606 }
4607 EXPORT_SYMBOL(netdev_master_upper_dev_get);
4608 
4609 void *netdev_adjacent_get_private(struct list_head *adj_list)
4610 {
4611         struct netdev_adjacent *adj;
4612 
4613         adj = list_entry(adj_list, struct netdev_adjacent, list);
4614 
4615         return adj->private;
4616 }
4617 EXPORT_SYMBOL(netdev_adjacent_get_private);
4618 
4619 /**
4620  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
4621  * @dev: device
4622  * @iter: list_head ** of the current position
4623  *
4624  * Gets the next device from the dev's upper list, starting from iter
4625  * position. The caller must hold RCU read lock.
4626  */
4627 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
4628                                                  struct list_head **iter)
4629 {
4630         struct netdev_adjacent *upper;
4631 
4632         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
4633 
4634         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
4635 
4636         if (&upper->list == &dev->adj_list.upper)
4637                 return NULL;
4638 
4639         *iter = &upper->list;
4640 
4641         return upper->dev;
4642 }
4643 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
4644 
4645 /**
4646  * netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list
4647  * @dev: device
4648  * @iter: list_head ** of the current position
4649  *
4650  * Gets the next device from the dev's upper list, starting from iter
4651  * position. The caller must hold RCU read lock.
4652  */
4653 struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
4654                                                      struct list_head **iter)
4655 {
4656         struct netdev_adjacent *upper;
4657 
4658         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
4659 
4660         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
4661 
4662         if (&upper->list == &dev->all_adj_list.upper)
4663                 return NULL;
4664 
4665         *iter = &upper->list;
4666 
4667         return upper->dev;
4668 }
4669 EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu);
4670 
4671 /**
4672  * netdev_lower_get_next_private - Get the next ->private from the
4673  *                                 lower neighbour list
4674  * @dev: device
4675  * @iter: list_head ** of the current position
4676  *
4677  * Gets the next netdev_adjacent->private from the dev's lower neighbour
4678  * list, starting from iter position. The caller must hold either hold the
4679  * RTNL lock or its own locking that guarantees that the neighbour lower
4680  * list will remain unchainged.
4681  */
4682 void *netdev_lower_get_next_private(struct net_device *dev,
4683                                     struct list_head **iter)
4684 {
4685         struct netdev_adjacent *lower;
4686 
4687         lower = list_entry(*iter, struct netdev_adjacent, list);
4688 
4689         if (&lower->list == &dev->adj_list.lower)
4690                 return NULL;
4691 
4692         *iter = lower->list.next;
4693 
4694         return lower->private;
4695 }
4696 EXPORT_SYMBOL(netdev_lower_get_next_private);
4697 
4698 /**
4699  * netdev_lower_get_next_private_rcu - Get the next ->private from the
4700  *                                     lower neighbour list, RCU
4701  *                                     variant
4702  * @dev: device
4703  * @iter: list_head ** of the current position
4704  *
4705  * Gets the next netdev_adjacent->private from the dev's lower neighbour
4706  * list, starting from iter position. The caller must hold RCU read lock.
4707  */
4708 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
4709                                         struct list_head **iter)
4710 {
4711         struct netdev_adjacent *lower;
4712 
4713         WARN_ON_ONCE(!rcu_read_lock_held());
4714 
4715         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
4716 
4717         if (&lower->list == &dev->adj_list.lower)
4718                 return NULL;
4719 
4720         *iter = &lower->list;
4721 
4722         return lower->private;
4723 }
4724 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
4725 
4726 /**
4727  * netdev_lower_get_next - Get the next device from the lower neighbour
4728  *                         list
4729  * @dev: device
4730  * @iter: list_head ** of the current position
4731  *
4732  * Gets the next netdev_adjacent from the dev's lower neighbour
4733  * list, starting from iter position. The caller must hold RTNL lock or
4734  * its own locking that guarantees that the neighbour lower
4735  * list will remain unchainged.
4736  */
4737 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
4738 {
4739         struct netdev_adjacent *lower;
4740 
4741         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
4742 
4743         if (&lower->list == &dev->adj_list.lower)
4744                 return NULL;
4745 
4746         *iter = &lower->list;
4747 
4748         return lower->dev;
4749 }
4750 EXPORT_SYMBOL(netdev_lower_get_next);
4751 
4752 /**
4753  * netdev_lower_get_first_private_rcu - Get the first ->private from the
4754  *                                     lower neighbour list, RCU
4755  *                                     variant
4756  * @dev: device
4757  *
4758  * Gets the first netdev_adjacent->private from the dev's lower neighbour
4759  * list. The caller must hold RCU read lock.
4760  */
4761 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
4762 {
4763         struct netdev_adjacent *lower;
4764 
4765         lower = list_first_or_null_rcu(&dev->adj_list.lower,
4766                         struct netdev_adjacent, list);
4767         if (lower)
4768                 return lower->private;
4769         return NULL;
4770 }
4771 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
4772 
4773 /**
4774  * netdev_master_upper_dev_get_rcu - Get master upper device
4775  * @dev: device
4776  *
4777  * Find a master upper device and return pointer to it or NULL in case
4778  * it's not there. The caller must hold the RCU read lock.
4779  */
4780 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
4781 {
4782         struct netdev_adjacent *upper;
4783 
4784         upper = list_first_or_null_rcu(&dev->adj_list.upper,
4785                                        struct netdev_adjacent, list);
4786         if (upper && likely(upper->master))
4787                 return upper->dev;
4788         return NULL;
4789 }
4790 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
4791 
4792 static int netdev_adjacent_sysfs_add(struct net_device *dev,
4793                               struct net_device *adj_dev,
4794                               struct list_head *dev_list)
4795 {
4796         char linkname[IFNAMSIZ+7];
4797         sprintf(linkname, dev_list == &dev->adj_list.upper ?
4798                 "upper_%s" : "lower_%s", adj_dev->name);
4799         return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
4800                                  linkname);
4801 }
4802 static void netdev_adjacent_sysfs_del(struct net_device *dev,
4803                                char *name,
4804                                struct list_head *dev_list)
4805 {
4806         char linkname[IFNAMSIZ+7];
4807         sprintf(linkname, dev_list == &dev->adj_list.upper ?
4808                 "upper_%s" : "lower_%s", name);
4809         sysfs_remove_link(&(dev->dev.kobj), linkname);
4810 }
4811 
4812 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
4813                                                  struct net_device *adj_dev,
4814                                                  struct list_head *dev_list)
4815 {
4816         return (dev_list == &dev->adj_list.upper ||
4817                 dev_list == &dev->adj_list.lower) &&
4818                 net_eq(dev_net(dev), dev_net(adj_dev));
4819 }
4820 
4821 static int __netdev_adjacent_dev_insert(struct net_device *dev,
4822                                         struct net_device *adj_dev,
4823                                         struct list_head *dev_list,
4824                                         void *private, bool master)
4825 {
4826         struct netdev_adjacent *adj;
4827         int ret;
4828 
4829         adj = __netdev_find_adj(dev, adj_dev, dev_list);
4830 
4831         if (adj) {
4832                 adj->ref_nr++;
4833                 return 0;
4834         }
4835 
4836         adj = kmalloc(sizeof(*adj), GFP_KERNEL);
4837         if (!adj)
4838                 return -ENOMEM;
4839 
4840         adj->dev = adj_dev;
4841         adj->master = master;
4842         adj->ref_nr = 1;
4843         adj->private = private;
4844         dev_hold(adj_dev);
4845 
4846         pr_debug("dev_hold for %s, because of link added from %s to %s\n",
4847                  adj_dev->name, dev->name, adj_dev->name);
4848 
4849         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
4850                 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
4851                 if (ret)
4852                         goto free_adj;
4853         }
4854 
4855         /* Ensure that master link is always the first item in list. */
4856         if (master) {
4857                 ret = sysfs_create_link(&(dev->dev.kobj),
4858                                         &(adj_dev->dev.kobj), "master");
4859                 if (ret)
4860                         goto remove_symlinks;
4861 
4862                 list_add_rcu(&adj->list, dev_list);
4863         } else {
4864                 list_add_tail_rcu(&adj->list, dev_list);
4865         }
4866 
4867         return 0;
4868 
4869 remove_symlinks:
4870         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
4871                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
4872 free_adj:
4873         kfree(adj);
4874         dev_put(adj_dev);
4875 
4876         return ret;
4877 }
4878 
4879 static void __netdev_adjacent_dev_remove(struct net_device *dev,
4880                                          struct net_device *adj_dev,
4881                                          struct list_head *dev_list)
4882 {
4883         struct netdev_adjacent *adj;
4884 
4885         adj = __netdev_find_adj(dev, adj_dev, dev_list);
4886 
4887         if (!adj) {
4888                 pr_err("tried to remove device %s from %s\n",
4889                        dev->name, adj_dev->name);
4890                 BUG();
4891         }
4892 
4893         if (adj->ref_nr > 1) {
4894                 pr_debug("%s to %s ref_nr-- = %d\n", dev->name, adj_dev->name,
4895                          adj->ref_nr-1);
4896                 adj->ref_nr--;
4897                 return;
4898         }
4899 
4900         if (adj->master)
4901                 sysfs_remove_link(&(dev->dev.kobj), "master");
4902 
4903         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
4904                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
4905 
4906         list_del_rcu(&adj->list);
4907         pr_debug("dev_put for %s, because link removed from %s to %s\n",
4908                  adj_dev->name, dev->name, adj_dev->name);
4909         dev_put(adj_dev);
4910         kfree_rcu(adj, rcu);
4911 }
4912 
4913 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
4914                                             struct net_device *upper_dev,
4915                                             struct list_head *up_list,
4916                                             struct list_head *down_list,
4917                                             void *private, bool master)
4918 {
4919         int ret;
4920 
4921         ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list, private,
4922                                            master);
4923         if (ret)
4924                 return ret;
4925 
4926         ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list, private,
4927                                            false);
4928         if (ret) {
4929                 __netdev_adjacent_dev_remove(dev, upper_dev, up_list);
4930                 return ret;
4931         }
4932 
4933         return 0;
4934 }
4935 
4936 static int __netdev_adjacent_dev_link(struct net_device *dev,
4937                                       struct net_device *upper_dev)
4938 {
4939         return __netdev_adjacent_dev_link_lists(dev, upper_dev,
4940                                                 &dev->all_adj_list.upper,
4941                                                 &upper_dev->all_adj_list.lower,
4942                                                 NULL, false);
4943 }
4944 
4945 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
4946                                                struct net_device *upper_dev,
4947                                                struct list_head *up_list,
4948                                                struct list_head *down_list)
4949 {
4950         __netdev_adjacent_dev_remove(dev, upper_dev, up_list);
4951         __netdev_adjacent_dev_remove(upper_dev, dev, down_list);
4952 }
4953 
4954 static void __netdev_adjacent_dev_unlink(struct net_device *dev,
4955                                          struct net_device *upper_dev)
4956 {
4957         __netdev_adjacent_dev_unlink_lists(dev, upper_dev,
4958                                            &dev->all_adj_list.upper,
4959                                            &upper_dev->all_adj_list.lower);
4960 }
4961 
4962 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
4963                                                 struct net_device *upper_dev,
4964                                                 void *private, bool master)
4965 {
4966         int ret = __netdev_adjacent_dev_link(dev, upper_dev);
4967 
4968         if (ret)
4969                 return ret;
4970 
4971         ret = __netdev_adjacent_dev_link_lists(dev, upper_dev,
4972                                                &dev->adj_list.upper,
4973                                                &upper_dev->adj_list.lower,
4974                                                private, master);
4975         if (ret) {
4976                 __netdev_adjacent_dev_unlink(dev, upper_dev);
4977                 return ret;
4978         }
4979 
4980         return 0;
4981 }
4982 
4983 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
4984                                                    struct net_device *upper_dev)
4985 {
4986         __netdev_adjacent_dev_unlink(dev, upper_dev);
4987         __netdev_adjacent_dev_unlink_lists(dev, upper_dev,
4988                                            &dev->adj_list.upper,
4989                                            &upper_dev->adj_list.lower);
4990 }
4991 
4992 static int __netdev_upper_dev_link(struct net_device *dev,
4993                                    struct net_device *upper_dev, bool master,
4994                                    void *private)
4995 {
4996         struct netdev_adjacent *i, *j, *to_i, *to_j;
4997         int ret = 0;
4998 
4999         ASSERT_RTNL();
5000 
5001         if (dev == upper_dev)
5002                 return -EBUSY;
5003 
5004         /* To prevent loops, check if dev is not upper device to upper_dev. */
5005         if (__netdev_find_adj(upper_dev, dev, &upper_dev->all_adj_list.upper))
5006                 return -EBUSY;
5007 
5008         if (__netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper))
5009                 return -EEXIST;
5010 
5011         if (master && netdev_master_upper_dev_get(dev))
5012                 return -EBUSY;
5013 
5014         ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, private,
5015                                                    master);
5016         if (ret)
5017                 return ret;
5018 
5019         /* Now that we linked these devs, make all the upper_dev's
5020          * all_adj_list.upper visible to every dev's all_adj_list.lower an
5021          * versa, and don't forget the devices itself. All of these
5022          * links are non-neighbours.
5023          */
5024         list_for_each_entry(i, &dev->all_adj_list.lower, list) {
5025                 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
5026                         pr_debug("Interlinking %s with %s, non-neighbour\n",
5027                                  i->dev->name, j->dev->name);
5028                         ret = __netdev_adjacent_dev_link(i->dev, j->dev);
5029                         if (ret)
5030                                 goto rollback_mesh;
5031                 }
5032         }
5033 
5034         /* add dev to every upper_dev's upper device */
5035         list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
5036                 pr_debug("linking %s's upper device %s with %s\n",
5037                          upper_dev->name, i->dev->name, dev->name);
5038                 ret = __netdev_adjacent_dev_link(dev, i->dev);
5039                 if (ret)
5040                         goto rollback_upper_mesh;
5041         }
5042 
5043         /* add upper_dev to every dev's lower device */
5044         list_for_each_entry(i, &dev->all_adj_list.lower, list) {
5045                 pr_debug("linking %s's lower device %s with %s\n", dev->name,
5046                          i->dev->name, upper_dev->name);
5047                 ret = __netdev_adjacent_dev_link(i->dev, upper_dev);
5048                 if (ret)
5049                         goto rollback_lower_mesh;
5050         }
5051 
5052         call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
5053         return 0;
5054 
5055 rollback_lower_mesh:
5056         to_i = i;
5057         list_for_each_entry(i, &dev->all_adj_list.lower, list) {
5058                 if (i == to_i)
5059                         break;
5060                 __netdev_adjacent_dev_unlink(i->dev, upper_dev);
5061         }
5062 
5063         i = NULL;
5064 
5065 rollback_upper_mesh:
5066         to_i = i;
5067         list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
5068                 if (i == to_i)
5069                         break;
5070                 __netdev_adjacent_dev_unlink(dev, i->dev);
5071         }
5072 
5073         i = j = NULL;
5074 
5075 rollback_mesh:
5076         to_i = i;
5077         to_j = j;
5078         list_for_each_entry(i, &dev->all_adj_list.lower, list) {
5079                 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
5080                         if (i == to_i && j == to_j)
5081                                 break;
5082                         __netdev_adjacent_dev_unlink(i->dev, j->dev);
5083                 }
5084                 if (i == to_i)
5085                         break;
5086         }
5087 
5088         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
5089 
5090         return ret;
5091 }
5092 
5093 /**
5094  * netdev_upper_dev_link - Add a link to the upper device
5095  * @dev: device
5096  * @upper_dev: new upper device
5097  *
5098  * Adds a link to device which is upper to this one. The caller must hold
5099  * the RTNL lock. On a failure a negative errno code is returned.
5100  * On success the reference counts are adjusted and the function
5101  * returns zero.
5102  */
5103 int netdev_upper_dev_link(struct net_device *dev,
5104                           struct net_device *upper_dev)
5105 {
5106         return __netdev_upper_dev_link(dev, upper_dev, false, NULL);
5107 }
5108 EXPORT_SYMBOL(netdev_upper_dev_link);
5109 
5110 /**
5111  * netdev_master_upper_dev_link - Add a master link to the upper device
5112  * @dev: device
5113  * @upper_dev: new upper device
5114  *
5115  * Adds a link to device which is upper to this one. In this case, only
5116  * one master upper device can be linked, although other non-master devices
5117  * might be linked as well. The caller must hold the RTNL lock.
5118  * On a failure a negative errno code is returned. On success the reference
5119  * counts are adjusted and the function returns zero.
5120  */
5121 int netdev_master_upper_dev_link(struct net_device *dev,
5122                                  struct net_device *upper_dev)
5123 {
5124         return __netdev_upper_dev_link(dev, upper_dev, true, NULL);
5125 }
5126 EXPORT_SYMBOL(netdev_master_upper_dev_link);
5127 
5128 int netdev_master_upper_dev_link_private(struct net_device *dev,
5129                                          struct net_device *upper_dev,
5130                                          void *private)
5131 {
5132         return __netdev_upper_dev_link(dev, upper_dev, true, private);
5133 }
5134 EXPORT_SYMBOL(netdev_master_upper_dev_link_private);
5135 
5136 /**
5137  * netdev_upper_dev_unlink - Removes a link to upper device
5138  * @dev: device
5139  * @upper_dev: new upper device
5140  *
5141  * Removes a link to device which is upper to this one. The caller must hold
5142  * the RTNL lock.
5143  */
5144 void netdev_upper_dev_unlink(struct net_device *dev,
5145                              struct net_device *upper_dev)
5146 {
5147         struct netdev_adjacent *i, *j;
5148         ASSERT_RTNL();
5149 
5150         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
5151 
5152         /* Here is the tricky part. We must remove all dev's lower
5153          * devices from all upper_dev's upper devices and vice
5154          * versa, to maintain the graph relationship.
5155          */
5156         list_for_each_entry(i, &dev->all_adj_list.lower, list)
5157                 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list)
5158                         __netdev_adjacent_dev_unlink(i->dev, j->dev);
5159 
5160         /* remove also the devices itself from lower/upper device
5161          * list
5162          */
5163         list_for_each_entry(i, &dev->all_adj_list.lower, list)
5164                 __netdev_adjacent_dev_unlink(i->dev, upper_dev);
5165 
5166         list_for_each_entry(i, &upper_dev->all_adj_list.upper, list)
5167                 __netdev_adjacent_dev_unlink(dev, i->dev);
5168 
5169         call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
5170 }
5171 EXPORT_SYMBOL(netdev_upper_dev_unlink);
5172 
5173 void netdev_adjacent_add_links(struct net_device *dev)
5174 {
5175         struct netdev_adjacent *iter;
5176 
5177         struct net *net = dev_net(dev);
5178 
5179         list_for_each_entry(iter, &dev->adj_list.upper, list) {
5180                 if (!net_eq(net,dev_net(iter->dev)))
5181                         continue;
5182                 netdev_adjacent_sysfs_add(iter->dev, dev,
5183                                           &iter->dev->adj_list.lower);
5184                 netdev_adjacent_sysfs_add(dev, iter->dev,
5185                                           &dev->adj_list.upper);
5186         }
5187 
5188         list_for_each_entry(iter, &dev->adj_list.lower, list) {
5189                 if (!net_eq(net,dev_net(iter->dev)))
5190                         continue;
5191                 netdev_adjacent_sysfs_add(iter->dev, dev,
5192                                           &iter->dev->adj_list.upper);
5193                 netdev_adjacent_sysfs_add(dev, iter->dev,
5194                                           &dev->adj_list.lower);
5195         }
5196 }
5197 
5198 void netdev_adjacent_del_links(struct net_device *dev)
5199 {
5200         struct netdev_adjacent *iter;
5201 
5202         struct net *net = dev_net(dev);
5203 
5204         list_for_each_entry(iter, &dev->adj_list.upper, list) {
5205                 if (!net_eq(net,dev_net(iter->dev)))
5206                         continue;
5207                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
5208                                           &iter->dev->adj_list.lower);
5209                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
5210                                           &dev->adj_list.upper);
5211         }
5212 
5213         list_for_each_entry(iter, &dev->adj_list.lower, list) {
5214                 if (!net_eq(net,dev_net(iter->dev)))
5215                         continue;
5216                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
5217                                           &iter->dev->adj_list.upper);
5218                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
5219                                           &dev->adj_list.lower);
5220         }
5221 }
5222 
5223 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
5224 {
5225         struct netdev_adjacent *iter;
5226 
5227         struct net *net = dev_net(dev);
5228 
5229         list_for_each_entry(iter, &dev->adj_list.upper, list) {
5230                 if (!net_eq(net,dev_net(iter->dev)))
5231                         continue;
5232                 netdev_adjacent_sysfs_del(iter->dev, oldname,
5233                                           &iter->dev->adj_list.lower);
5234                 netdev_adjacent_sysfs_add(iter->dev, dev,
5235                                           &iter->dev->adj_list.lower);
5236         }
5237 
5238         list_for_each_entry(iter, &dev->adj_list.lower, list) {
5239                 if (!net_eq(net,dev_net(iter->dev)))
5240                         continue;
5241                 netdev_adjacent_sysfs_del(iter->dev, oldname,
5242                                           &iter->dev->adj_list.upper);
5243                 netdev_adjacent_sysfs_add(iter->dev, dev,
5244                                           &iter->dev->adj_list.upper);
5245         }
5246 }
5247 
5248 void *netdev_lower_dev_get_private(struct net_device *dev,
5249                                    struct net_device *lower_dev)
5250 {
5251         struct netdev_adjacent *lower;
5252 
5253         if (!lower_dev)
5254                 return NULL;
5255         lower = __netdev_find_adj(dev, lower_dev, &dev->adj_list.lower);
5256         if (!lower)
5257                 return NULL;
5258 
5259         return lower->private;
5260 }
5261 EXPORT_SYMBOL(netdev_lower_dev_get_private);
5262 
5263 
5264 int dev_get_nest_level(struct net_device *dev,
5265                        bool (*type_check)(struct net_device *dev))
5266 {
5267         struct net_device *lower = NULL;
5268         struct list_head *iter;
5269         int max_nest = -1;
5270         int nest;
5271 
5272         ASSERT_RTNL();
5273 
5274         netdev_for_each_lower_dev(dev, lower, iter) {
5275                 nest = dev_get_nest_level(lower, type_check);
5276                 if (max_nest < nest)
5277                         max_nest = nest;
5278         }
5279 
5280         if (type_check(dev))
5281                 max_nest++;
5282 
5283         return max_nest;
5284 }
5285 EXPORT_SYMBOL(dev_get_nest_level);
5286 
5287 static void dev_change_rx_flags(struct net_device *dev, int flags)
5288 {
5289         const struct net_device_ops *ops = dev->netdev_ops;
5290 
5291         if (ops->ndo_change_rx_flags)
5292                 ops->ndo_change_rx_flags(dev, flags);
5293 }
5294 
5295 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
5296 {
5297         unsigned int old_flags = dev->flags;
5298         kuid_t uid;
5299         kgid_t gid;
5300 
5301         ASSERT_RTNL();
5302 
5303         dev->flags |= IFF_PROMISC;
5304         dev->promiscuity += inc;
5305         if (dev->promiscuity == 0) {
5306                 /*
5307                  * Avoid overflow.
5308                  * If inc causes overflow, untouch promisc and return error.
5309                  */
5310                 if (inc < 0)
5311                         dev->flags &= ~IFF_PROMISC;
5312                 else {
5313                         dev->promiscuity -= inc;
5314                         pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
5315                                 dev->name);
5316                         return -EOVERFLOW;
5317                 }
5318         }
5319         if (dev->flags != old_flags) {
5320                 pr_info("device %s %s promiscuous mode\n",
5321                         dev->name,
5322                         dev->flags & IFF_PROMISC ? "entered" : "left");
5323                 if (audit_enabled) {
5324                         current_uid_gid(&uid, &gid);
5325                         audit_log(current->audit_context, GFP_ATOMIC,
5326                                 AUDIT_ANOM_PROMISCUOUS,
5327                                 "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
5328                                 dev->name, (dev->flags & IFF_PROMISC),
5329                                 (old_flags & IFF_PROMISC),
5330                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
5331                                 from_kuid(&init_user_ns, uid),
5332                                 from_kgid(&init_user_ns, gid),
5333                                 audit_get_sessionid(current));
5334                 }
5335 
5336                 dev_change_rx_flags(dev, IFF_PROMISC);
5337         }
5338         if (notify)
5339                 __dev_notify_flags(dev, old_flags, IFF_PROMISC);
5340         return 0;
5341 }
5342 
5343 /**
5344  *      dev_set_promiscuity     - update promiscuity count on a device
5345  *      @dev: device
5346  *      @inc: modifier
5347  *
5348  *      Add or remove promiscuity from a device. While the count in the device
5349  *      remains above zero the interface remains promiscuous. Once it hits zero
5350  *      the device reverts back to normal filtering operation. A negative inc
5351  *      value is used to drop promiscuity on the device.
5352  *      Return 0 if successful or a negative errno code on error.
5353  */
5354 int dev_set_promiscuity(struct net_device *dev, int inc)
5355 {
5356         unsigned int old_flags = dev->flags;
5357         int err;
5358 
5359         err = __dev_set_promiscuity(dev, inc, true);
5360         if (err < 0)
5361                 return err;
5362         if (dev->flags != old_flags)
5363                 dev_set_rx_mode(dev);
5364         return err;
5365 }
5366 EXPORT_SYMBOL(dev_set_promiscuity);
5367 
5368 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
5369 {
5370         unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
5371 
5372         ASSERT_RTNL();
5373 
5374         dev->flags |= IFF_ALLMULTI;
5375         dev->allmulti += inc;
5376         if (dev->allmulti == 0) {
5377                 /*
5378                  * Avoid overflow.
5379                  * If inc causes overflow, untouch allmulti and return error.
5380                  */
5381                 if (inc < 0)
5382                         dev->flags &= ~IFF_ALLMULTI;
5383                 else {
5384                         dev->allmulti -= inc;
5385                         pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
5386                                 dev->name);
5387                         return -EOVERFLOW;
5388                 }
5389         }
5390         if (dev->flags ^ old_flags) {
5391                 dev_change_rx_flags(dev, IFF_ALLMULTI);
5392                 dev_set_rx_mode(dev);
5393                 if (notify)
5394                         __dev_notify_flags(dev, old_flags,
5395                                            dev->gflags ^ old_gflags);
5396         }
5397         return 0;
5398 }
5399 
5400 /**
5401  *      dev_set_allmulti        - update allmulti count on a device
5402  *      @dev: device
5403  *      @inc: modifier
5404  *
5405  *      Add or remove reception of all multicast frames to a device. While the
5406  *      count in the device remains above zero the interface remains listening
5407  *      to all interfaces. Once it hits zero the device reverts back to normal
5408  *      filtering operation. A negative @inc value is used to drop the counter
5409  *      when releasing a resource needing all multicasts.
5410  *      Return 0 if successful or a negative errno code on error.
5411  */
5412 
5413 int dev_set_allmulti(struct net_device *dev, int inc)
5414 {
5415         return __dev_set_allmulti(dev, inc, true);
5416 }
5417 EXPORT_SYMBOL(dev_set_allmulti);
5418 
5419 /*
5420  *      Upload unicast and multicast address lists to device and
5421  *      configure RX filtering. When the device doesn't support unicast
5422  *      filtering it is put in promiscuous mode while unicast addresses
5423  *      are present.
5424  */
5425 void __dev_set_rx_mode(struct net_device *dev)
5426 {
5427         const struct net_device_ops *ops = dev->netdev_ops;
5428 
5429         /* dev_open will call this function so the list will stay sane. */
5430         if (!(dev->flags&IFF_UP))
5431                 return;
5432 
5433         if (!netif_device_present(dev))
5434                 return;
5435 
5436         if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
5437                 /* Unicast addresses changes may only happen under the rtnl,
5438                  * therefore calling __dev_set_promiscuity here is safe.
5439                  */
5440                 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
5441                         __dev_set_promiscuity(dev, 1, false);
5442                         dev->uc_promisc = true;
5443                 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
5444                         __dev_set_promiscuity(dev, -1, false);
5445                         dev->uc_promisc = false;
5446                 }
5447         }
5448 
5449         if (ops->ndo_set_rx_mode)
5450                 ops->ndo_set_rx_mode(dev);
5451 }
5452 
5453 void dev_set_rx_mode(struct net_device *dev)
5454 {
5455         netif_addr_lock_bh(dev);
5456         __dev_set_rx_mode(dev);
5457         netif_addr_unlock_bh(dev);
5458 }
5459 
5460 /**
5461  *      dev_get_flags - get flags reported to userspace
5462  *      @dev: device
5463  *
5464  *      Get the combination of flag bits exported through APIs to userspace.
5465  */
5466 unsigned int dev_get_flags(const struct net_device *dev)
5467 {
5468         unsigned int flags;
5469 
5470         flags = (dev->flags & ~(IFF_PROMISC |
5471                                 IFF_ALLMULTI |
5472                                 IFF_RUNNING |
5473                                 IFF_LOWER_UP |
5474                                 IFF_DORMANT)) |
5475                 (dev->gflags & (IFF_PROMISC |
5476                                 IFF_ALLMULTI));
5477 
5478         if (netif_running(dev)) {
5479                 if (netif_oper_up(dev))
5480                         flags |= IFF_RUNNING;
5481                 if (netif_carrier_ok(dev))
5482                         flags |= IFF_LOWER_UP;
5483                 if (netif_dormant(dev))
5484                         flags |= IFF_DORMANT;
5485         }
5486 
5487         return flags;
5488 }
5489 EXPORT_SYMBOL(dev_get_flags);
5490 
5491 int __dev_change_flags(struct net_device *dev, unsigned int flags)
5492 {
5493         unsigned int old_flags = dev->flags;
5494         int ret;
5495 
5496         ASSERT_RTNL();
5497 
5498         /*
5499          *      Set the flags on our device.
5500          */
5501 
5502         dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
5503                                IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
5504                                IFF_AUTOMEDIA)) |
5505                      (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
5506                                     IFF_ALLMULTI));
5507 
5508         /*
5509          *      Load in the correct multicast list now the flags have changed.
5510          */
5511 
5512         if ((old_flags ^ flags) & IFF_MULTICAST)
5513                 dev_change_rx_flags(dev, IFF_MULTICAST);
5514 
5515         dev_set_rx_mode(dev);
5516 
5517         /*
5518          *      Have we downed the interface. We handle IFF_UP ourselves
5519          *      according to user attempts to set it, rather than blindly
5520          *      setting it.
5521          */
5522 
5523         ret = 0;
5524         if ((old_flags ^ flags) & IFF_UP)
5525                 ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
5526 
5527         if ((flags ^ dev->gflags) & IFF_PROMISC) {
5528                 int inc = (flags & IFF_PROMISC) ? 1 : -1;
5529                 unsigned int old_flags = dev->flags;
5530 
5531                 dev->gflags ^= IFF_PROMISC;
5532 
5533                 if (__dev_set_promiscuity(dev, inc, false) >= 0)
5534                         if (dev->flags != old_flags)
5535                                 dev_set_rx_mode(dev);
5536         }
5537 
5538         /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
5539            is important. Some (broken) drivers set IFF_PROMISC, when
5540            IFF_ALLMULTI is requested not asking us and not reporting.
5541          */
5542         if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
5543                 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
5544 
5545                 dev->gflags ^= IFF_ALLMULTI;
5546                 __dev_set_allmulti(dev, inc, false);
5547         }
5548 
5549         return ret;
5550 }
5551 
5552 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
5553                         unsigned int gchanges)
5554 {
5555         unsigned int changes = dev->flags ^ old_flags;
5556 
5557         if (gchanges)
5558                 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
5559 
5560         if (changes & IFF_UP) {
5561                 if (dev->flags & IFF_UP)
5562                         call_netdevice_notifiers(NETDEV_UP, dev);
5563                 else
5564                         call_netdevice_notifiers(NETDEV_DOWN, dev);
5565         }
5566 
5567         if (dev->flags & IFF_UP &&
5568             (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
5569                 struct netdev_notifier_change_info change_info;
5570 
5571                 change_info.flags_changed = changes;
5572                 call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
5573                                               &change_info.info);
5574         }
5575 }
5576 
5577 /**
5578  *      dev_change_flags - change device settings
5579  *      @dev: device
5580  *      @flags: device state flags
5581  *
5582  *      Change settings on device based state flags. The flags are
5583  *      in the userspace exported format.
5584  */
5585 int dev_change_flags(struct net_device *dev, unsigned int flags)
5586 {
5587         int ret;
5588         unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
5589 
5590         ret = __dev_change_flags(dev, flags);
5591         if (ret < 0)
5592                 return ret;
5593 
5594         changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
5595         __dev_notify_flags(dev, old_flags, changes);
5596         return ret;
5597 }
5598 EXPORT_SYMBOL(dev_change_flags);
5599 
5600 static int __dev_set_mtu(struct net_device *dev, int new_mtu)
5601 {
5602         const struct net_device_ops *ops = dev->netdev_ops;
5603 
5604         if (ops->ndo_change_mtu)
5605                 return ops->ndo_change_mtu(dev, new_mtu);
5606 
5607         dev->mtu = new_mtu;
5608         return 0;
5609 }
5610 
5611 /**
5612  *      dev_set_mtu - Change maximum transfer unit
5613  *      @dev: device
5614  *      @new_mtu: new transfer unit
5615  *
5616  *      Change the maximum transfer size of the network device.
5617  */
5618 int dev_set_mtu(struct net_device *dev, int new_mtu)
5619 {
5620         int err, orig_mtu;
5621 
5622         if (new_mtu == dev->mtu)
5623                 return 0;
5624 
5625         /*      MTU must be positive.    */
5626         if (new_mtu < 0)
5627                 return -EINVAL;
5628 
5629         if (!netif_device_present(dev))
5630                 return -ENODEV;
5631 
5632         err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
5633         err = notifier_to_errno(err);
5634         if (err)
5635                 return err;
5636 
5637         orig_mtu = dev->mtu;
5638         err = __dev_set_mtu(dev, new_mtu);
5639 
5640         if (!err) {
5641                 err = call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
5642                 err = notifier_to_errno(err);
5643                 if (err) {
5644                         /* setting mtu back and notifying everyone again,
5645                          * so that they have a chance to revert changes.
5646                          */
5647                         __dev_set_mtu(dev, orig_mtu);
5648                         call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
5649                 }
5650         }
5651         return err;
5652 }
5653 EXPORT_SYMBOL(dev_set_mtu);
5654 
5655 /**
5656  *      dev_set_group - Change group this device belongs to
5657  *      @dev: device
5658  *      @new_group: group this device should belong to
5659  */
5660 void dev_set_group(struct net_device *dev, int new_group)
5661 {
5662         dev->group = new_group;
5663 }
5664 EXPORT_SYMBOL(dev_set_group);
5665 
5666 /**
5667  *      dev_set_mac_address - Change Media Access Control Address
5668  *      @dev: device
5669  *      @sa: new address
5670  *
5671  *      Change the hardware (MAC) address of the device
5672  */
5673 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
5674 {
5675         const struct net_device_ops *ops = dev->netdev_ops;
5676         int err;
5677 
5678         if (!ops->ndo_set_mac_address)
5679                 return -EOPNOTSUPP;
5680         if (sa->sa_family != dev->type)
5681                 return -EINVAL;
5682         if (!netif_device_present(dev))
5683                 return -ENODEV;
5684         err = ops->ndo_set_mac_address(dev, sa);
5685         if (err)
5686                 return err;
5687         dev->addr_assign_type = NET_ADDR_SET;
5688         call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
5689         add_device_randomness(dev->dev_addr, dev->addr_len);
5690         return 0;
5691 }
5692 EXPORT_SYMBOL(dev_set_mac_address);
5693 
5694 /**
5695  *      dev_change_carrier - Change device carrier
5696  *      @dev: device
5697  *      @new_carrier: new value
5698  *
5699  *      Change device carrier
5700  */
5701 int dev_change_carrier(struct net_device *dev, bool new_carrier)
5702 {
5703         const struct net_device_ops *ops = dev->netdev_ops;
5704 
5705         if (!ops->ndo_change_carrier)
5706                 return -EOPNOTSUPP;
5707         if (!netif_device_present(dev))
5708                 return -ENODEV;
5709         return ops->ndo_change_carrier(dev, new_carrier);
5710 }
5711 EXPORT_SYMBOL(dev_change_carrier);
5712 
5713 /**
5714  *      dev_get_phys_port_id - Get device physical port ID
5715  *      @dev: device
5716  *      @ppid: port ID
5717  *
5718  *      Get device physical port ID
5719  */
5720 int dev_get_phys_port_id(struct net_device *dev,
5721                          struct netdev_phys_port_id *ppid)
5722 {
5723         const struct net_device_ops *ops = dev->netdev_ops;
5724 
5725         if (!ops->ndo_get_phys_port_id)
5726                 return -EOPNOTSUPP;
5727         return ops->ndo_get_phys_port_id(dev, ppid);
5728 }
5729 EXPORT_SYMBOL(dev_get_phys_port_id);
5730 
5731 /**
5732  *      dev_new_index   -       allocate an ifindex
5733  *      @net: the applicable net namespace
5734  *
5735  *      Returns a suitable unique value for a new device interface
5736  *      number.  The caller must hold the rtnl semaphore or the
5737  *      dev_base_lock to be sure it remains unique.
5738  */
5739 static int dev_new_index(struct net *net)
5740 {
5741         int ifindex = net->ifindex;
5742         for (;;) {
5743                 if (++ifindex <= 0)
5744                         ifindex = 1;
5745                 if (!__dev_get_by_index(net, ifindex))
5746                         return net->ifindex = ifindex;
5747         }
5748 }
5749 
5750 /* Delayed registration/unregisteration */
5751 static LIST_HEAD(net_todo_list);
5752 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
5753 
5754 static void net_set_todo(struct net_device *dev)
5755 {
5756         list_add_tail(&dev->todo_list, &net_todo_list);
5757         dev_net(dev)->dev_unreg_count++;
5758 }
5759 
5760 static void rollback_registered_many(struct list_head *head)
5761 {
5762         struct net_device *dev, *tmp;
5763         LIST_HEAD(close_head);
5764 
5765         BUG_ON(dev_boot_phase);
5766         ASSERT_RTNL();
5767 
5768         list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5769                 /* Some devices call without registering
5770                  * for initialization unwind. Remove those
5771                  * devices and proceed with the remaining.
5772                  */
5773                 if (dev->reg_state == NETREG_UNINITIALIZED) {
5774                         pr_debug("unregister_netdevice: device %s/%p never was registered\n",
5775                                  dev->name, dev);
5776 
5777                         WARN_ON(1);
5778                         list_del(&dev->unreg_list);
5779                         continue;
5780                 }
5781                 dev->dismantle = true;
5782                 BUG_ON(dev->reg_state != NETREG_REGISTERED);
5783         }
5784 
5785         /* If device is running, close it first. */
5786         list_for_each_entry(dev, head, unreg_list)
5787                 list_add_tail(&dev->close_list, &close_head);
5788         dev_close_many(&close_head);
5789 
5790         list_for_each_entry(dev, head, unreg_list) {
5791                 /* And unlink it from device chain. */
5792                 unlist_netdevice(dev);
5793 
5794                 dev->reg_state = NETREG_UNREGISTERING;
5795         }
5796 
5797         synchronize_net();
5798 
5799         list_for_each_entry(dev, head, unreg_list) {
5800                 /* Shutdown queueing discipline. */
5801                 dev_shutdown(dev);
5802 
5803 
5804                 /* Notify protocols, that we are about to destroy
5805                    this device. They should clean all the things.
5806                 */
5807                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5808 
5809                 /*
5810                  *      Flush the unicast and multicast chains
5811                  */
5812                 dev_uc_flush(dev);
5813                 dev_mc_flush(dev);
5814 
5815                 if (dev->netdev_ops->ndo_uninit)
5816                         dev->netdev_ops->ndo_uninit(dev);
5817 
5818                 if (!dev->rtnl_link_ops ||
5819                     dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5820                         rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
5821 
5822                 /* Notifier chain MUST detach us all upper devices. */
5823                 WARN_ON(netdev_has_any_upper_dev(dev));
5824 
5825                 /* Remove entries from kobject tree */
5826                 netdev_unregister_kobject(dev);
5827 #ifdef CONFIG_XPS
5828                 /* Remove XPS queueing entries */
5829                 netif_reset_xps_queues_gt(dev, 0);
5830 #endif
5831         }
5832 
5833         synchronize_net();
5834 
5835         list_for_each_entry(dev, head, unreg_list)
5836                 dev_put(dev);
5837 }
5838 
5839 static void rollback_registered(struct net_device *dev)
5840 {
5841         LIST_HEAD(single);
5842 
5843         list_add(&dev->unreg_list, &single);
5844         rollback_registered_many(&single);
5845         list_del(&single);
5846 }
5847 
5848 static netdev_features_t netdev_fix_features(struct net_device *dev,
5849         netdev_features_t features)
5850 {
5851         /* Fix illegal checksum combinations */
5852         if ((features & NETIF_F_HW_CSUM) &&
5853             (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5854                 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5855                 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
5856         }
5857 
5858         /* TSO requires that SG is present as well. */
5859         if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5860                 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5861                 features &= ~NETIF_F_ALL_TSO;
5862         }
5863 
5864         if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
5865                                         !(features & NETIF_F_IP_CSUM)) {
5866                 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
5867                 features &= ~NETIF_F_TSO;
5868                 features &= ~NETIF_F_TSO_ECN;
5869         }
5870 
5871         if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
5872                                          !(features & NETIF_F_IPV6_CSUM)) {
5873                 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
5874                 features &= ~NETIF_F_TSO6;
5875         }
5876 
5877         /* TSO ECN requires that TSO is present as well. */
5878         if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
5879                 features &= ~NETIF_F_TSO_ECN;
5880 
5881         /* Software GSO depends on SG. */
5882         if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5883                 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5884                 features &= ~NETIF_F_GSO;
5885         }
5886 
5887         /* UFO needs SG and checksumming */
5888         if (features & NETIF_F_UFO) {
5889                 /* maybe split UFO into V4 and V6? */
5890                 if (!((features & NETIF_F_GEN_CSUM) ||
5891                     (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
5892                             == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5893                         netdev_dbg(dev,
5894                                 "Dropping NETIF_F_UFO since no checksum offload features.\n");
5895                         features &= ~NETIF_F_UFO;
5896                 }
5897 
5898                 if (!(features & NETIF_F_SG)) {
5899                         netdev_dbg(dev,
5900                                 "Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5901                         features &= ~NETIF_F_UFO;
5902                 }
5903         }
5904 
5905 #ifdef CONFIG_NET_RX_BUSY_POLL
5906         if (dev->netdev_ops->ndo_busy_poll)
5907                 features |= NETIF_F_BUSY_POLL;
5908         else
5909 #endif
5910                 features &= ~NETIF_F_BUSY_POLL;
5911 
5912         return features;
5913 }
5914 
5915 int __netdev_update_features(struct net_device *dev)
5916 {
5917         netdev_features_t features;
5918         int err = 0;
5919 
5920         ASSERT_RTNL();
5921 
5922         features = netdev_get_wanted_features(dev);
5923 
5924         if (dev->netdev_ops->ndo_fix_features)
5925                 features = dev->netdev_ops->ndo_fix_features(dev, features);
5926 
5927         /* driver might be less strict about feature dependencies */
5928         features = netdev_fix_features(dev, features);
5929 
5930         if (dev->features == features)
5931                 return 0;
5932 
5933         netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
5934                 &dev->features, &features);
5935 
5936         if (dev->netdev_ops->ndo_set_features)
5937                 err = dev->netdev_ops->ndo_set_features(dev, features);
5938 
5939         if (unlikely(err < 0)) {
5940                 netdev_err(dev,
5941                         "set_features() failed (%d); wanted %pNF, left %pNF\n",
5942                         err, &features, &dev->features);
5943                 return -1;
5944         }
5945 
5946         if (!err)
5947                 dev->features = features;
5948 
5949         return 1;
5950 }
5951 
5952 /**
5953  *      netdev_update_features - recalculate device features
5954  *      @dev: the device to check
5955  *
5956  *      Recalculate dev->features set and send notifications if it
5957  *      has changed. Should be called after driver or hardware dependent
5958  *      conditions might have changed that influence the features.
5959  */
5960 void netdev_update_features(struct net_device *dev)
5961 {
5962         if (__netdev_update_features(dev))
5963                 netdev_features_change(dev);
5964 }
5965 EXPORT_SYMBOL(netdev_update_features);
5966 
5967 /**
5968  *      netdev_change_features - recalculate device features
5969  *      @dev: the device to check
5970  *
5971  *      Recalculate dev->features set and send notifications even
5972  *      if they have not changed. Should be called instead of
5973  *      netdev_update_features() if also dev->vlan_features might
5974  *      have changed to allow the changes to be propagated to stacked
5975  *      VLAN devices.
5976  */
5977 void netdev_change_features(struct net_device *dev)
5978 {
5979         __netdev_update_features(dev);
5980         netdev_features_change(dev);
5981 }
5982 EXPORT_SYMBOL(netdev_change_features);
5983 
5984 /**
5985  *      netif_stacked_transfer_operstate -      transfer operstate
5986  *      @rootdev: the root or lower level device to transfer state from
5987  *      @dev: the device to transfer operstate to
5988  *
5989  *      Transfer operational state from root to device. This is normally
5990  *      called when a stacking relationship exists between the root
5991  *      device and the device(a leaf device).
5992  */
5993 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
5994                                         struct net_device *dev)
5995 {
5996         if (rootdev->operstate == IF_OPER_DORMANT)
5997                 netif_dormant_on(dev);
5998         else
5999                 netif_dormant_off(dev);
6000 
6001         if (netif_carrier_ok(rootdev)) {
6002                 if (!netif_carrier_ok(dev))
6003                         netif_carrier_on(dev);
6004         } else {
6005                 if (netif_carrier_ok(dev))
6006                         netif_carrier_off(dev);
6007         }
6008 }
6009 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
6010 
6011 #ifdef CONFIG_SYSFS
6012 static int netif_alloc_rx_queues(struct net_device *dev)
6013 {
6014         unsigned int i, count = dev->num_rx_queues;
6015         struct netdev_rx_queue *rx;
6016 
6017         BUG_ON(count < 1);
6018 
6019         rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
6020         if (!rx)
6021                 return -ENOMEM;
6022 
6023         dev->_rx = rx;
6024 
6025         for (i = 0; i < count; i++)
6026                 rx[i].dev = dev;
6027         return 0;
6028 }
6029 #endif
6030 
6031 static void netdev_init_one_queue(struct net_device *dev,
6032                                   struct netdev_queue *queue, void *_unused)
6033 {
6034         /* Initialize queue lock */
6035         spin_lock_init(&queue->_xmit_lock);
6036         netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
6037         queue->xmit_lock_owner = -1;
6038         netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
6039         queue->dev = dev;
6040 #ifdef CONFIG_BQL
6041         dql_init(&queue->dql, HZ);
6042 #endif
6043 }
6044 
6045 static void netif_free_tx_queues(struct net_device *dev)
6046 {
6047         kvfree(dev->_tx);
6048 }
6049 
6050 static int netif_alloc_netdev_queues(struct net_device *dev)
6051 {
6052         unsigned int count = dev->num_tx_queues;
6053         struct netdev_queue *tx;
6054         size_t sz = count * sizeof(*tx);
6055 
6056         BUG_ON(count < 1 || count > 0xffff);
6057 
6058         tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
6059         if (!tx) {
6060                 tx = vzalloc(sz);
6061                 if (!tx)
6062                         return -ENOMEM;
6063         }
6064         dev->_tx = tx;
6065 
6066         netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
6067         spin_lock_init(&dev->tx_global_lock);
6068 
6069         return 0;
6070 }
6071 
6072 /**
6073  *      register_netdevice      - register a network device
6074  *      @dev: device to register
6075  *
6076  *      Take a completed network device structure and add it to the kernel
6077  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
6078  *      chain. 0 is returned on success. A negative errno code is returned
6079  *      on a failure to set up the device, or if the name is a duplicate.
6080  *
6081  *      Callers must hold the rtnl semaphore. You may want
6082  *      register_netdev() instead of this.
6083  *
6084  *      BUGS:
6085  *      The locking appears insufficient to guarantee two parallel registers
6086  *      will not get the same name.
6087  */
6088 
6089 int register_netdevice(struct net_device *dev)
6090 {
6091         int ret;
6092         struct net *net = dev_net(dev);
6093 
6094         BUG_ON(dev_boot_phase);
6095         ASSERT_RTNL();
6096 
6097         might_sleep();
6098 
6099         /* When net_device's are persistent, this will be fatal. */
6100         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
6101         BUG_ON(!net);
6102 
6103         spin_lock_init(&dev->addr_list_lock);
6104         netdev_set_addr_lockdep_class(dev);
6105 
6106         dev->iflink = -1;
6107 
6108         ret = dev_get_valid_name(net, dev, dev->name);
6109         if (ret < 0)
6110                 goto out;
6111 
6112         /* Init, if this function is available */
6113         if (dev->netdev_ops->ndo_init) {
6114                 ret = dev->netdev_ops->ndo_init(dev);
6115                 if (ret) {
6116                         if (ret > 0)
6117                                 ret = -EIO;
6118                         goto out;
6119                 }
6120         }
6121 
6122         if (((dev->hw_features | dev->features) &
6123              NETIF_F_HW_VLAN_CTAG_FILTER) &&
6124             (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
6125              !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
6126                 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
6127                 ret = -EINVAL;
6128                 goto err_uninit;
6129         }
6130 
6131         ret = -EBUSY;
6132         if (!dev->ifindex)
6133                 dev->ifindex = dev_new_index(net);
6134         else if (__dev_get_by_index(net, dev->ifindex))
6135                 goto err_uninit;
6136 
6137         if (dev->iflink == -1)
6138                 dev->iflink = dev->ifindex;
6139 
6140         /* Transfer changeable features to wanted_features and enable
6141          * software offloads (GSO and GRO).
6142          */
6143         dev->hw_features |= NETIF_F_SOFT_FEATURES;
6144         dev->features |= NETIF_F_SOFT_FEATURES;
6145         dev->wanted_features = dev->features & dev->hw_features;
6146 
6147         if (!(dev->flags & IFF_LOOPBACK)) {
6148                 dev->hw_features |= NETIF_F_NOCACHE_COPY;
6149         }
6150 
6151         /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
6152          */
6153         dev->vlan_features |= NETIF_F_HIGHDMA;
6154 
6155         /* Make NETIF_F_SG inheritable to tunnel devices.
6156          */
6157         dev->hw_enc_features |= NETIF_F_SG;
6158 
6159         /* Make NETIF_F_SG inheritable to MPLS.
6160          */
6161         dev->mpls_features |= NETIF_F_SG;
6162 
6163         ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
6164         ret = notifier_to_errno(ret);
6165         if (ret)
6166                 goto err_uninit;
6167 
6168         ret = netdev_register_kobject(dev);
6169         if (ret)
6170                 goto err_uninit;
6171         dev->reg_state = NETREG_REGISTERED;
6172 
6173         __netdev_update_features(dev);
6174 
6175         /*
6176          *      Default initial state at registry is that the
6177          *      device is present.
6178          */
6179 
6180         set_bit(__LINK_STATE_PRESENT, &dev->state);
6181 
6182         linkwatch_init_dev(dev);
6183 
6184         dev_init_scheduler(dev);
6185         dev_hold(dev);
6186         list_netdevice(dev);
6187         add_device_randomness(dev->dev_addr, dev->addr_len);
6188 
6189         /* If the device has permanent device address, driver should
6190          * set dev_addr and also addr_assign_type should be set to
6191          * NET_ADDR_PERM (default value).
6192          */
6193         if (dev->addr_assign_type == NET_ADDR_PERM)
6194                 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
6195 
6196         /* Notify protocols, that a new device appeared. */
6197         ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
6198         ret = notifier_to_errno(ret);
6199         if (ret) {
6200                 rollback_registered(dev);
6201                 dev->reg_state = NETREG_UNREGISTERED;
6202         }
6203         /*
6204          *      Prevent userspace races by waiting until the network
6205          *      device is fully setup before sending notifications.
6206          */
6207         if (!dev->rtnl_link_ops ||
6208             dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
6209                 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
6210 
6211 out:
6212         return ret;
6213 
6214 err_uninit:
6215         if (dev->netdev_ops->ndo_uninit)
6216                 dev->netdev_ops->ndo_uninit(dev);
6217         goto out;
6218 }
6219 EXPORT_SYMBOL(register_netdevice);
6220 
6221 /**
6222  *      init_dummy_netdev       - init a dummy network device for NAPI
6223  *      @dev: device to init
6224  *
6225  *      This takes a network device structure and initialize the minimum
6226  *      amount of fields so it can be used to schedule NAPI polls without
6227  *      registering a full blown interface. This is to be used by drivers
6228  *      that need to tie several hardware interfaces to a single NAPI
6229  *      poll scheduler due to HW limitations.
6230  */
6231 int init_dummy_netdev(struct net_device *dev)
6232 {
6233         /* Clear everything. Note we don't initialize spinlocks
6234          * are they aren't supposed to be taken by any of the
6235          * NAPI code and this dummy netdev is supposed to be
6236          * only ever used for NAPI polls
6237          */
6238         memset(dev, 0, sizeof(struct net_device));
6239 
6240         /* make sure we BUG if trying to hit standard
6241          * register/unregister code path
6242          */
6243         dev->reg_state = NETREG_DUMMY;
6244 
6245         /* NAPI wants this */
6246         INIT_LIST_HEAD(&dev->napi_list);
6247 
6248         /* a dummy interface is started by default */
6249         set_bit(__LINK_STATE_PRESENT, &dev->state);
6250         set_bit(__LINK_STATE_START, &dev->state);
6251 
6252         /* Note : We dont allocate pcpu_refcnt for dummy devices,
6253          * because users of this 'device' dont need to change
6254          * its refcount.
6255          */
6256 
6257         return 0;
6258 }
6259 EXPORT_SYMBOL_GPL(init_dummy_netdev);
6260 
6261 
6262 /**
6263  *      register_netdev - register a network device
6264  *      @dev: device to register
6265  *
6266  *      Take a completed network device structure and add it to the kernel
6267  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
6268  *      chain. 0 is returned on success. A negative errno code is returned
6269  *      on a failure to set up the device, or if the name is a duplicate.
6270  *
6271  *      This is a wrapper around register_netdevice that takes the rtnl semaphore
6272  *      and expands the device name if you passed a format string to
6273  *      alloc_netdev.
6274  */
6275 int register_netdev(struct net_device *dev)
6276 {
6277         int err;
6278 
6279         rtnl_lock();
6280         err = register_netdevice(dev);
6281         rtnl_unlock();
6282         return err;
6283 }
6284 EXPORT_SYMBOL(register_netdev);
6285 
6286 int netdev_refcnt_read(const struct net_device *dev)
6287 {
6288         int i, refcnt = 0;
6289 
6290         for_each_possible_cpu(i)
6291                 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
6292         return refcnt;
6293 }
6294 EXPORT_SYMBOL(netdev_refcnt_read);
6295 
6296 /**
6297  * netdev_wait_allrefs - wait until all references are gone.
6298  * @dev: target net_device
6299  *
6300  * This is called when unregistering network devices.
6301  *
6302  * Any protocol or device that holds a reference should register
6303  * for netdevice notification, and cleanup and put back the
6304  * reference if they receive an UNREGISTER event.
6305  * We can get stuck here if buggy protocols don't correctly
6306  * call dev_put.
6307  */
6308 static void netdev_wait_allrefs(struct net_device *dev)
6309 {
6310         unsigned long rebroadcast_time, warning_time;
6311         int refcnt;
6312 
6313         linkwatch_forget_dev(dev);
6314 
6315         rebroadcast_time = warning_time = jiffies;
6316         refcnt = netdev_refcnt_read(dev);
6317 
6318         while (refcnt != 0) {
6319                 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
6320                         rtnl_lock();
6321 
6322                         /* Rebroadcast unregister notification */
6323                         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6324 
6325                         __rtnl_unlock();
6326                         rcu_barrier();
6327                         rtnl_lock();
6328 
6329                         call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6330                         if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
6331                                      &dev->state)) {
6332                                 /* We must not have linkwatch events
6333                                  * pending on unregister. If this
6334                                  * happens, we simply run the queue
6335                                  * unscheduled, resulting in a noop
6336                                  * for this device.
6337                                  */
6338                                 linkwatch_run_queue();
6339                         }
6340 
6341                         __rtnl_unlock();
6342 
6343                         rebroadcast_time = jiffies;
6344                 }
6345 
6346                 msleep(250);
6347 
6348                 refcnt = netdev_refcnt_read(dev);
6349 
6350                 if (time_after(jiffies, warning_time + 10 * HZ)) {
6351                         pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
6352                                  dev->name, refcnt);
6353                         warning_time = jiffies;
6354                 }
6355         }
6356 }
6357 
6358 /* The sequence is:
6359  *
6360  *      rtnl_lock();
6361  *      ...
6362  *      register_netdevice(x1);
6363  *      register_netdevice(x2);
6364  *      ...
6365  *      unregister_netdevice(y1);
6366  *      unregister_netdevice(y2);
6367  *      ...
6368  *      rtnl_unlock();
6369  *      free_netdev(y1);
6370  *      free_netdev(y2);
6371  *
6372  * We are invoked by rtnl_unlock().
6373  * This allows us to deal with problems:
6374  * 1) We can delete sysfs objects which invoke hotplug
6375  *    without deadlocking with linkwatch via keventd.
6376  * 2) Since we run with the RTNL semaphore not held, we can sleep
6377  *    safely in order to wait for the netdev refcnt to drop to zero.
6378  *
6379  * We must not return until all unregister events added during
6380  * the interval the lock was held have been completed.
6381  */
6382 void netdev_run_todo(void)
6383 {
6384         struct list_head list;
6385 
6386         /* Snapshot list, allow later requests */
6387         list_replace_init(&net_todo_list, &list);
6388 
6389         __rtnl_unlock();
6390 
6391 
6392         /* Wait for rcu callbacks to finish before next phase */
6393         if (!list_empty(&list))
6394                 rcu_barrier();
6395 
6396         while (!list_empty(&list)) {
6397                 struct net_device *dev
6398                         = list_first_entry(&list, struct net_device, todo_list);
6399                 list_del(&dev->todo_list);
6400 
6401                 rtnl_lock();
6402                 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6403                 __rtnl_unlock();
6404 
6405                 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
6406                         pr_err("network todo '%s' but state %d\n",
6407                                dev->name, dev->reg_state);
6408                         dump_stack();
6409                         continue;
6410                 }
6411 
6412                 dev->reg_state = NETREG_UNREGISTERED;
6413 
6414                 on_each_cpu(flush_backlog, dev, 1);
6415 
6416                 netdev_wait_allrefs(dev);
6417 
6418                 /* paranoia */
6419                 BUG_ON(netdev_refcnt_read(dev));
6420                 WARN_ON(rcu_access_pointer(dev->ip_ptr));
6421                 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
6422                 WARN_ON(dev->dn_ptr);
6423 
6424                 if (dev->destructor)
6425                         dev->destructor(dev);
6426 
6427                 /* Report a network device has been unregistered */
6428                 rtnl_lock();
6429                 dev_net(dev)->dev_unreg_count--;
6430                 __rtnl_unlock();
6431                 wake_up(&netdev_unregistering_wq);
6432 
6433                 /* Free network device */
6434                 kobject_put(&dev->dev.kobj);
6435         }
6436 }
6437 
6438 /* Convert net_device_stats to rtnl_link_stats64.  They have the same
6439  * fields in the same order, with only the type differing.
6440  */
6441 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
6442                              const struct net_device_stats *netdev_stats)
6443 {
6444 #if BITS_PER_LONG == 64
6445         BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
6446         memcpy(stats64, netdev_stats, sizeof(*stats64));
6447 #else
6448         size_t i, n = sizeof(*stats64) / sizeof(u64);
6449         const unsigned long *src = (const unsigned long *)netdev_stats;
6450         u64 *dst = (u64 *)stats64;
6451 
6452         BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
6453                      sizeof(*stats64) / sizeof(u64));
6454         for (i = 0; i < n; i++)
6455                 dst[i] = src[i];
6456 #endif
6457 }
6458 EXPORT_SYMBOL(netdev_stats_to_stats64);
6459 
6460 /**
6461  *      dev_get_stats   - get network device statistics
6462  *      @dev: device to get statistics from
6463  *      @storage: place to store stats
6464  *
6465  *      Get network statistics from device. Return @storage.
6466  *      The device driver may provide its own method by setting
6467  *      dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
6468  *      otherwise the internal statistics structure is used.
6469  */
6470 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
6471                                         struct rtnl_link_stats64 *storage)
6472 {
6473         const struct net_device_ops *ops = dev->netdev_ops;
6474 
6475         if (ops->ndo_get_stats64) {
6476                 memset(storage, 0, sizeof(*storage));
6477                 ops->ndo_get_stats64(dev, storage);
6478         } else if (ops->ndo_get_stats) {
6479                 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
6480         } else {
6481                 netdev_stats_to_stats64(storage, &dev->stats);
6482         }
6483         storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
6484         storage->tx_dropped += atomic_long_read(&dev->tx_dropped);
6485         return storage;
6486 }
6487 EXPORT_SYMBOL(dev_get_stats);
6488 
6489 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
6490 {
6491         struct netdev_queue *queue = dev_ingress_queue(dev);
6492 
6493 #ifdef CONFIG_NET_CLS_ACT
6494         if (queue)
6495                 return queue;
6496         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
6497         if (!queue)
6498                 return NULL;
6499         netdev_init_one_queue(dev, queue, NULL);
6500         queue->qdisc = &noop_qdisc;
6501         queue->qdisc_sleeping = &noop_qdisc;
6502         rcu_assign_pointer(dev->ingress_queue, queue);
6503 #endif
6504         return queue;
6505 }
6506 
6507 static const struct ethtool_ops default_ethtool_ops;
6508 
6509 void netdev_set_default_ethtool_ops(struct net_device *dev,
6510                                     const struct ethtool_ops *ops)
6511 {
6512         if (dev->ethtool_ops == &default_ethtool_ops)
6513                 dev->ethtool_ops = ops;
6514 }
6515 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
6516 
6517 void netdev_freemem(struct net_device *dev)
6518 {
6519         char *addr = (char *)dev - dev->padded;
6520 
6521         kvfree(addr);
6522 }
6523 
6524 /**
6525  *      alloc_netdev_mqs - allocate network device
6526  *      @sizeof_priv:           size of private data to allocate space for
6527  *      @name:                  device name format string
6528  *      @name_assign_type:      origin of device name
6529  *      @setup:                 callback to initialize device
6530  *      @txqs:                  the number of TX subqueues to allocate
6531  *      @rxqs:                  the number of RX subqueues to allocate
6532  *
6533  *      Allocates a struct net_device with private data area for driver use
6534  *      and performs basic initialization.  Also allocates subqueue structs
6535  *      for each queue on the device.
6536  */
6537 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
6538                 unsigned char name_assign_type,
6539                 void (*setup)(struct net_device *),
6540                 unsigned int txqs, unsigned int rxqs)
6541 {
6542         struct net_device *dev;
6543         size_t alloc_size;
6544         struct net_device *p;
6545 
6546         BUG_ON(strlen(name) >= sizeof(dev->name));
6547 
6548         if (txqs < 1) {
6549                 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
6550                 return NULL;
6551         }
6552 
6553 #ifdef CONFIG_SYSFS
6554         if (rxqs < 1) {
6555                 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
6556                 return NULL;
6557         }
6558 #endif
6559 
6560         alloc_size = sizeof(struct net_device);
6561         if (sizeof_priv) {
6562                 /* ensure 32-byte alignment of private area */
6563                 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
6564                 alloc_size += sizeof_priv;
6565         }
6566         /* ensure 32-byte alignment of whole construct */
6567         alloc_size += NETDEV_ALIGN - 1;
6568 
6569         p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
6570         if (!p)
6571                 p = vzalloc(alloc_size);
6572         if (!p)
6573                 return NULL;
6574 
6575         dev = PTR_ALIGN(p, NETDEV_ALIGN);
6576         dev->padded = (char *)dev - (char *)p;
6577 
6578         dev->pcpu_refcnt = alloc_percpu(int);
6579         if (!dev->pcpu_refcnt)
6580                 goto free_dev;
6581 
6582         if (dev_addr_init(dev))
6583                 goto free_pcpu;
6584 
6585         dev_mc_init(dev);
6586         dev_uc_init(dev);
6587 
6588         dev_net_set(dev, &init_net);
6589 
6590         dev->gso_max_size = GSO_MAX_SIZE;
6591         dev->gso_max_segs = GSO_MAX_SEGS;
6592 
6593         INIT_LIST_HEAD(&dev->napi_list);
6594         INIT_LIST_HEAD(&dev->unreg_list);
6595         INIT_LIST_HEAD(&dev->close_list);
6596         INIT_LIST_HEAD(&dev->link_watch_list);
6597         INIT_LIST_HEAD(&dev->adj_list.upper);
6598         INIT_LIST_HEAD(&dev->adj_list.lower);
6599         INIT_LIST_HEAD(&dev->all_adj_list.upper);
6600         INIT_LIST_HEAD(&dev->all_adj_list.lower);
6601         dev->priv_flags = IFF_XMIT_DST_RELEASE;
6602         setup(dev);
6603 
6604         dev->num_tx_queues = txqs;
6605         dev->real_num_tx_queues = txqs;
6606         if (netif_alloc_netdev_queues(dev))
6607                 goto free_all;
6608 
6609 #ifdef CONFIG_SYSFS
6610         dev->num_rx_queues = rxqs;
6611         dev->real_num_rx_queues = rxqs;
6612         if (netif_alloc_rx_queues(dev))
6613                 goto free_all;
6614 #endif
6615 
6616         strcpy(dev->name, name);
6617         dev->name_assign_type = name_assign_type;
6618         dev->group = INIT_NETDEV_GROUP;
6619         if (!dev->ethtool_ops)
6620                 dev->ethtool_ops = &default_ethtool_ops;
6621         return dev;
6622 
6623 free_all:
6624         free_netdev(dev);
6625         return NULL;
6626 
6627 free_pcpu:
6628         free_percpu(dev->pcpu_refcnt);
6629 free_dev:
6630         netdev_freemem(dev);
6631         return NULL;
6632 }
6633 EXPORT_SYMBOL(alloc_netdev_mqs);
6634 
6635 /**
6636  *      free_netdev - free network device
6637  *      @dev: device
6638  *
6639  *      This function does the last stage of destroying an allocated device
6640  *      interface. The reference to the device object is released.
6641  *      If this is the last reference then it will be freed.
6642  */
6643 void free_netdev(struct net_device *dev)
6644 {
6645         struct napi_struct *p, *n;
6646 
6647         release_net(dev_net(dev));
6648 
6649         netif_free_tx_queues(dev);
6650 #ifdef CONFIG_SYSFS
6651         kfree(dev->_rx);
6652 #endif
6653 
6654         kfree(rcu_dereference_protected(dev->ingress_queue, 1));
6655 
6656         /* Flush device addresses */
6657         dev_addr_flush(dev);
6658 
6659         list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
6660                 netif_napi_del(p);
6661 
6662         free_percpu(dev->pcpu_refcnt);
6663         dev->pcpu_refcnt = NULL;
6664 
6665         /*  Compatibility with error handling in drivers */
6666         if (dev->reg_state == NETREG_UNINITIALIZED) {
6667                 netdev_freemem(dev);
6668                 return;
6669         }
6670 
6671         BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
6672         dev->reg_state = NETREG_RELEASED;
6673 
6674         /* will free via device release */
6675         put_device(&dev->dev);
6676 }
6677 EXPORT_SYMBOL(free_netdev);
6678 
6679 /**
6680  *      synchronize_net -  Synchronize with packet receive processing
6681  *
6682  *      Wait for packets currently being received to be done.
6683  *      Does not block later packets from starting.
6684  */
6685 void synchronize_net(void)
6686 {
6687         might_sleep();
6688         if (rtnl_is_locked())
6689                 synchronize_rcu_expedited();
6690         else
6691                 synchronize_rcu();
6692 }
6693 EXPORT_SYMBOL(synchronize_net);
6694 
6695 /**
6696  *      unregister_netdevice_queue - remove device from the kernel
6697  *      @dev: device
6698  *      @head: list
6699  *
6700  *      This function shuts down a device interface and removes it
6701  *      from the kernel tables.
6702  *      If head not NULL, device is queued to be unregistered later.
6703  *
6704  *      Callers must hold the rtnl semaphore.  You may want
6705  *      unregister_netdev() instead of this.
6706  */
6707 
6708 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
6709 {
6710         ASSERT_RTNL();
6711 
6712         if (head) {
6713                 list_move_tail(&dev->unreg_list, head);
6714         } else {
6715                 rollback_registered(dev);
6716                 /* Finish processing unregister after unlock */
6717                 net_set_todo(dev);
6718         }
6719 }
6720 EXPORT_SYMBOL(unregister_netdevice_queue);
6721 
6722 /**
6723  *      unregister_netdevice_many - unregister many devices
6724  *      @head: list of devices
6725  *
6726  *  Note: As most callers use a stack allocated list_head,
6727  *  we force a list_del() to make sure stack wont be corrupted later.
6728  */
6729 void unregister_netdevice_many(struct list_head *head)
6730 {
6731         struct net_device *dev;
6732 
6733         if (!list_empty(head)) {
6734                 rollback_registered_many(head);
6735                 list_for_each_entry(dev, head, unreg_list)
6736                         net_set_todo(dev);
6737                 list_del(head);
6738         }
6739 }
6740 EXPORT_SYMBOL(unregister_netdevice_many);
6741 
6742 /**
6743  *      unregister_netdev - remove device from the kernel
6744  *      @dev: device
6745  *
6746  *      This function shuts down a device interface and removes it
6747  *      from the kernel tables.
6748  *
6749  *      This is just a wrapper for unregister_netdevice that takes
6750  *      the rtnl semaphore.  In general you want to use this and not
6751  *      unregister_netdevice.
6752  */
6753 void unregister_netdev(struct net_device *dev)
6754 {
6755         rtnl_lock();
6756         unregister_netdevice(dev);
6757         rtnl_unlock();
6758 }
6759 EXPORT_SYMBOL(unregister_netdev);
6760 
6761 /**
6762  *      dev_change_net_namespace - move device to different nethost namespace
6763  *      @dev: device
6764  *      @net: network namespace
6765  *      @pat: If not NULL name pattern to try if the current device name
6766  *            is already taken in the destination network namespace.
6767  *
6768  *      This function shuts down a device interface and moves it
6769  *      to a new network namespace. On success 0 is returned, on
6770  *      a failure a netagive errno code is returned.
6771  *
6772  *      Callers must hold the rtnl semaphore.
6773  */
6774 
6775 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
6776 {
6777         int err;
6778 
6779         ASSERT_RTNL();
6780 
6781         /* Don't allow namespace local devices to be moved. */
6782         err = -EINVAL;
6783         if (dev->features & NETIF_F_NETNS_LOCAL)
6784                 goto out;
6785 
6786         /* Ensure the device has been registrered */
6787         if (dev->reg_state != NETREG_REGISTERED)
6788                 goto out;
6789 
6790         /* Get out if there is nothing todo */
6791         err = 0;
6792         if (net_eq(dev_net(dev), net))
6793                 goto out;
6794 
6795         /* Pick the destination device name, and ensure
6796          * we can use it in the destination network namespace.
6797          */
6798         err = -EEXIST;
6799         if (__dev_get_by_name(net, dev->name)) {
6800                 /* We get here if we can't use the current device name */
6801                 if (!pat)
6802                         goto out;
6803                 if (dev_get_valid_name(net, dev, pat) < 0)
6804                         goto out;
6805         }
6806 
6807         /*
6808          * And now a mini version of register_netdevice unregister_netdevice.
6809          */
6810 
6811         /* If device is running close it first. */
6812         dev_close(dev);
6813 
6814         /* And unlink it from device chain */
6815         err = -ENODEV;
6816         unlist_netdevice(dev);
6817 
6818         synchronize_net();
6819 
6820         /* Shutdown queueing discipline. */
6821         dev_shutdown(dev);
6822 
6823         /* Notify protocols, that we are about to destroy
6824            this device. They should clean all the things.
6825 
6826            Note that dev->reg_state stays at NETREG_REGISTERED.
6827            This is wanted because this way 8021q and macvlan know
6828            the device is just moving and can keep their slaves up.
6829         */
6830         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6831         rcu_barrier();
6832         call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6833         rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
6834 
6835         /*
6836          *      Flush the unicast and multicast chains
6837          */
6838         dev_uc_flush(dev);
6839         dev_mc_flush(dev);
6840 
6841         /* Send a netdev-removed uevent to the old namespace */
6842         kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
6843         netdev_adjacent_del_links(dev);
6844 
6845         /* Actually switch the network namespace */
6846         dev_net_set(dev, net);
6847 
6848         /* If there is an ifindex conflict assign a new one */
6849         if (__dev_get_by_index(net, dev->ifindex)) {
6850                 int iflink = (dev->iflink == dev->ifindex);
6851                 dev->ifindex = dev_new_index(net);
6852                 if (iflink)
6853                         dev->iflink = dev->ifindex;
6854         }
6855 
6856         /* Send a netdev-add uevent to the new namespace */
6857         kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
6858         netdev_adjacent_add_links(dev);
6859 
6860         /* Fixup kobjects */
6861         err = device_rename(&dev->dev, dev->name);
6862         WARN_ON(err);
6863 
6864         /* Add the device back in the hashes */
6865         list_netdevice(dev);
6866 
6867         /* Notify protocols, that a new device appeared. */
6868         call_netdevice_notifiers(NETDEV_REGISTER, dev);
6869 
6870         /*
6871          *      Prevent userspace races by waiting until the network
6872          *      device is fully setup before sending notifications.
6873          */
6874         rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
6875 
6876         synchronize_net();
6877         err = 0;
6878 out:
6879         return err;
6880 }
6881 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6882 
6883 static int dev_cpu_callback(struct notifier_block *nfb,
6884                             unsigned long action,
6885                             void *ocpu)
6886 {
6887         struct sk_buff **list_skb;
6888         struct sk_buff *skb;
6889         unsigned int cpu, oldcpu = (unsigned long)ocpu;
6890         struct softnet_data *sd, *oldsd;
6891 
6892         if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
6893                 return NOTIFY_OK;
6894 
6895         local_irq_disable();
6896         cpu = smp_processor_id();
6897         sd = &per_cpu(softnet_data, cpu);
6898         oldsd = &per_cpu(softnet_data, oldcpu);
6899 
6900         /* Find end of our completion_queue. */
6901         list_skb = &sd->completion_queue;
6902         while (*list_skb)
6903                 list_skb = &(*list_skb)->next;
6904         /* Append completion queue from offline CPU. */
6905         *list_skb = oldsd->completion_queue;
6906         oldsd->completion_queue = NULL;
6907 
6908         /* Append output queue from offline CPU. */
6909         if (oldsd->output_queue) {
6910                 *sd->output_queue_tailp = oldsd->output_queue;
6911                 sd->output_queue_tailp = oldsd->output_queue_tailp;
6912                 oldsd->output_queue = NULL;
6913                 oldsd->output_queue_tailp = &oldsd->output_queue;
6914         }
6915         /* Append NAPI poll list from offline CPU. */
6916         if (!list_empty(&oldsd->poll_list)) {
6917                 list_splice_init(&oldsd->poll_list, &sd->poll_list);
6918                 raise_softirq_irqoff(NET_RX_SOFTIRQ);
6919         }
6920 
6921         raise_softirq_irqoff(NET_TX_SOFTIRQ);
6922         local_irq_enable();
6923 
6924         /* Process offline CPU's input_pkt_queue */
6925         while ((skb = __skb_dequeue(&oldsd->process_queue))) {
6926                 netif_rx_internal(skb);
6927                 input_queue_head_incr(oldsd);
6928         }
6929         while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6930                 netif_rx_internal(skb);
6931                 input_queue_head_incr(oldsd);
6932         }
6933 
6934         return NOTIFY_OK;
6935 }
6936 
6937 
6938 /**
6939  *      netdev_increment_features - increment feature set by one
6940  *      @all: current feature set
6941  *      @one: new feature set
6942  *      @mask: mask feature set
6943  *
6944  *      Computes a new feature set after adding a device with feature set
6945  *      @one to the master device with current feature set @all.  Will not
6946  *      enable anything that is off in @mask. Returns the new feature set.
6947  */
6948 netdev_features_t netdev_increment_features(netdev_features_t all,
6949         netdev_features_t one, netdev_features_t mask)
6950 {
6951         if (mask & NETIF_F_GEN_CSUM)
6952                 mask |= NETIF_F_ALL_CSUM;
6953         mask |= NETIF_F_VLAN_CHALLENGED;
6954 
6955         all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
6956         all &= one | ~NETIF_F_ALL_FOR_ALL;
6957 
6958         /* If one device supports hw checksumming, set for all. */
6959         if (all & NETIF_F_GEN_CSUM)
6960                 all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6961 
6962         return all;
6963 }
6964 EXPORT_SYMBOL(netdev_increment_features);
6965 
6966 static struct hlist_head * __net_init netdev_create_hash(void)
6967 {
6968         int i;
6969         struct hlist_head *hash;
6970 
6971         hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
6972         if (hash != NULL)
6973                 for (i = 0; i < NETDEV_HASHENTRIES; i++)
6974                         INIT_HLIST_HEAD(&hash[i]);
6975 
6976         return hash;
6977 }
6978 
6979 /* Initialize per network namespace state */
6980 static int __net_init netdev_init(struct net *net)
6981 {
6982         if (net != &init_net)
6983                 INIT_LIST_HEAD(&net->dev_base_head);
6984 
6985         net->dev_name_head = netdev_create_hash();
6986         if (net->dev_name_head == NULL)
6987                 goto err_name;
6988 
6989         net->dev_index_head = netdev_create_hash();
6990         if (net->dev_index_head == NULL)
6991                 goto err_idx;
6992 
6993         return 0;
6994 
6995 err_idx:
6996         kfree(net->dev_name_head);
6997 err_name:
6998         return -ENOMEM;
6999 }
7000 
7001 /**
7002  *      netdev_drivername - network driver for the device
7003  *      @dev: network device
7004  *
7005  *      Determine network driver for device.
7006  */
7007 const char *netdev_drivername(const struct net_device *dev)
7008 {
7009         const struct device_driver *driver;
7010         const struct device *parent;
7011         const char *empty = "";
7012 
7013         parent = dev->dev.parent;
7014         if (!parent)
7015                 return empty;
7016 
7017         driver = parent->driver;
7018         if (driver && driver->name)
7019                 return driver->name;
7020         return empty;
7021 }
7022 
7023 static int __netdev_printk(const char *level, const struct net_device *dev,
7024                            struct va_format *vaf)
7025 {
7026         int r;
7027 
7028         if (dev && dev->dev.parent) {
7029                 r = dev_printk_emit(level[1] - '',
7030                                     dev->dev.parent,
7031                                     "%s %s %s%s: %pV",
7032                                     dev_driver_string(dev->dev.parent),
7033                                     dev_name(dev->dev.parent),
7034                                     netdev_name(dev), netdev_reg_state(dev),
7035                                     vaf);
7036         } else if (dev) {
7037                 r = printk("%s%s%s: %pV", level, netdev_name(dev),
7038                            netdev_reg_state(dev), vaf);
7039         } else {
7040                 r = printk("%s(NULL net_device): %pV", level, vaf);
7041         }
7042 
7043         return r;
7044 }
7045 
7046 int netdev_printk(const char *level, const struct net_device *dev,
7047                   const char *format, ...)
7048 {
7049         struct va_format vaf;
7050         va_list args;
7051         int r;
7052 
7053         va_start(args, format);
7054 
7055         vaf.fmt = format;
7056         vaf.va = &args;
7057 
7058         r = __netdev_printk(level, dev, &vaf);
7059 
7060         va_end(args);
7061 
7062         return r;
7063 }
7064 EXPORT_SYMBOL(netdev_printk);
7065 
7066 #define define_netdev_printk_level(func, level)                 \
7067 int func(const struct net_device *dev, const char *fmt, ...)    \
7068 {                                                               \
7069         int r;                                                  \
7070         struct va_format vaf;                                   \
7071         va_list args;                                           \
7072                                                                 \
7073         va_start(args, fmt);                                    \
7074                                                                 \
7075         vaf.fmt = fmt;                                          \
7076         vaf.va = &args;                                         \
7077                                                                 \
7078         r = __netdev_printk(level, dev, &vaf);                  \
7079                                                                 \
7080         va_end(args);                                           \
7081                                                                 \
7082         return r;                                               \
7083 }                                                               \
7084 EXPORT_SYMBOL(func);
7085 
7086 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
7087 define_netdev_printk_level(netdev_alert, KERN_ALERT);
7088 define_netdev_printk_level(netdev_crit, KERN_CRIT);
7089 define_netdev_printk_level(netdev_err, KERN_ERR);
7090 define_netdev_printk_level(netdev_warn, KERN_WARNING);
7091 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
7092 define_netdev_printk_level(netdev_info, KERN_INFO);
7093 
7094 static void __net_exit netdev_exit(struct net *net)
7095 {
7096         kfree(net->dev_name_head);
7097         kfree(net->dev_index_head);
7098 }
7099 
7100 static struct pernet_operations __net_initdata netdev_net_ops = {
7101         .init = netdev_init,
7102         .exit = netdev_exit,
7103 };
7104 
7105 static void __net_exit default_device_exit(struct net *net)
7106 {
7107         struct net_device *dev, *aux;
7108         /*
7109          * Push all migratable network devices back to the
7110          * initial network namespace
7111          */
7112         rtnl_lock();
7113         for_each_netdev_safe(net, dev, aux) {
7114                 int err;
7115                 char fb_name[IFNAMSIZ];
7116 
7117                 /* Ignore unmoveable devices (i.e. loopback) */
7118                 if (dev->features & NETIF_F_NETNS_LOCAL)
7119                         continue;
7120 
7121                 /* Leave virtual devices for the generic cleanup */
7122                 if (dev->rtnl_link_ops)
7123                         continue;
7124 
7125                 /* Push remaining network devices to init_net */
7126                 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
7127                 err = dev_change_net_namespace(dev, &init_net, fb_name);
7128                 if (err) {
7129                         pr_emerg("%s: failed to move %s to init_net: %d\n",
7130                                  __func__, dev->name, err);
7131                         BUG();
7132                 }
7133         }
7134         rtnl_unlock();
7135 }
7136 
7137 static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
7138 {
7139         /* Return with the rtnl_lock held when there are no network
7140          * devices unregistering in any network namespace in net_list.
7141          */
7142         struct net *net;
7143         bool unregistering;
7144         DEFINE_WAIT(wait);
7145 
7146         for (;;) {
7147                 prepare_to_wait(&netdev_unregistering_wq, &wait,
7148                                 TASK_UNINTERRUPTIBLE);
7149                 unregistering = false;
7150                 rtnl_lock();
7151                 list_for_each_entry(net, net_list, exit_list) {
7152                         if (net->dev_unreg_count > 0) {
7153                                 unregistering = true;
7154                                 break;
7155                         }
7156                 }
7157                 if (!unregistering)
7158                         break;
7159                 __rtnl_unlock();
7160                 schedule();
7161         }
7162         finish_wait(&netdev_unregistering_wq, &wait);
7163 }
7164 
7165 static void __net_exit default_device_exit_batch(struct list_head *net_list)
7166 {
7167         /* At exit all network devices most be removed from a network
7168          * namespace.  Do this in the reverse order of registration.
7169          * Do this across as many network namespaces as possible to
7170          * improve batching efficiency.
7171          */
7172         struct net_device *dev;
7173         struct net *net;
7174         LIST_HEAD(dev_kill_list);
7175 
7176         /* To prevent network device cleanup code from dereferencing
7177          * loopback devices or network devices that have been freed
7178          * wait here for all pending unregistrations to complete,
7179          * before unregistring the loopback device and allowing the
7180          * network namespace be freed.
7181          *
7182          * The netdev todo list containing all network devices
7183          * unregistrations that happen in default_device_exit_batch
7184          * will run in the rtnl_unlock() at the end of
7185          * default_device_exit_batch.
7186          */
7187         rtnl_lock_unregistering(net_list);
7188         list_for_each_entry(net, net_list, exit_list) {
7189                 for_each_netdev_reverse(net, dev) {
7190                         if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
7191                                 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
7192                         else
7193                                 unregister_netdevice_queue(dev, &dev_kill_list);
7194                 }
7195         }
7196         unregister_netdevice_many(&dev_kill_list);
7197         rtnl_unlock();
7198 }
7199 
7200 static struct pernet_operations __net_initdata default_device_ops = {
7201         .exit = default_device_exit,
7202         .exit_batch = default_device_exit_batch,
7203 };
7204 
7205 /*
7206  *      Initialize the DEV module. At boot time this walks the device list and
7207  *      unhooks any devices that fail to initialise (normally hardware not
7208  *      present) and leaves us with a valid list of present and active devices.
7209  *
7210  */
7211 
7212 /*
7213  *       This is called single threaded during boot, so no need
7214  *       to take the rtnl semaphore.
7215  */
7216 static int __init net_dev_init(void)
7217 {
7218         int i, rc = -ENOMEM;
7219 
7220         BUG_ON(!dev_boot_phase);
7221 
7222         if (dev_proc_init())
7223                 goto out;
7224 
7225         if (netdev_kobject_init())
7226                 goto out;
7227 
7228         INIT_LIST_HEAD(&ptype_all);
7229         for (i = 0; i < PTYPE_HASH_SIZE; i++)
7230                 INIT_LIST_HEAD(&ptype_base[i]);
7231 
7232         INIT_LIST_HEAD(&offload_base);
7233 
7234         if (register_pernet_subsys(&netdev_net_ops))
7235                 goto out;
7236 
7237         /*
7238          *      Initialise the packet receive queues.
7239          */
7240 
7241         for_each_possible_cpu(i) {
7242                 struct softnet_data *sd = &per_cpu(softnet_data, i);
7243 
7244                 skb_queue_head_init(&sd->input_pkt_queue);
7245                 skb_queue_head_init(&sd->process_queue);
7246                 INIT_LIST_HEAD(&sd->poll_list);
7247                 sd->output_queue_tailp = &sd->output_queue;
7248 #ifdef CONFIG_RPS
7249                 sd->csd.func = rps_trigger_softirq;
7250                 sd->csd.info = sd;
7251                 sd->cpu = i;
7252 #endif
7253 
7254                 sd->backlog.poll = process_backlog;
7255                 sd->backlog.weight = weight_p;
7256         }
7257 
7258         dev_boot_phase = 0;
7259 
7260         /* The loopback device is special if any other network devices
7261          * is present in a network namespace the loopback device must
7262          * be present. Since we now dynamically allocate and free the
7263          * loopback device ensure this invariant is maintained by
7264          * keeping the loopback device as the first device on the
7265          * list of network devices.  Ensuring the loopback devices
7266          * is the first device that appears and the last network device
7267          * that disappears.
7268          */
7269         if (register_pernet_device(&loopback_net_ops))
7270                 goto out;
7271 
7272         if (register_pernet_device(&default_device_ops))
7273                 goto out;
7274 
7275         open_softirq(NET_TX_SOFTIRQ, net_tx_action);
7276         open_softirq(NET_RX_SOFTIRQ, net_rx_action);
7277 
7278         hotcpu_notifier(dev_cpu_callback, 0);
7279         dst_init();
7280         rc = 0;
7281 out:
7282         return rc;
7283 }
7284 
7285 subsys_initcall(net_dev_init);
7286 

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