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TOMOYO Linux Cross Reference
Linux/net/core/dev.c

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  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 <linux/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/sched/mm.h>
 85 #include <linux/mutex.h>
 86 #include <linux/string.h>
 87 #include <linux/mm.h>
 88 #include <linux/socket.h>
 89 #include <linux/sockios.h>
 90 #include <linux/errno.h>
 91 #include <linux/interrupt.h>
 92 #include <linux/if_ether.h>
 93 #include <linux/netdevice.h>
 94 #include <linux/etherdevice.h>
 95 #include <linux/ethtool.h>
 96 #include <linux/notifier.h>
 97 #include <linux/skbuff.h>
 98 #include <linux/bpf.h>
 99 #include <linux/bpf_trace.h>
100 #include <net/net_namespace.h>
101 #include <net/sock.h>
102 #include <net/busy_poll.h>
103 #include <linux/rtnetlink.h>
104 #include <linux/stat.h>
105 #include <net/dst.h>
106 #include <net/dst_metadata.h>
107 #include <net/pkt_sched.h>
108 #include <net/pkt_cls.h>
109 #include <net/checksum.h>
110 #include <net/xfrm.h>
111 #include <linux/highmem.h>
112 #include <linux/init.h>
113 #include <linux/module.h>
114 #include <linux/netpoll.h>
115 #include <linux/rcupdate.h>
116 #include <linux/delay.h>
117 #include <net/iw_handler.h>
118 #include <asm/current.h>
119 #include <linux/audit.h>
120 #include <linux/dmaengine.h>
121 #include <linux/err.h>
122 #include <linux/ctype.h>
123 #include <linux/if_arp.h>
124 #include <linux/if_vlan.h>
125 #include <linux/ip.h>
126 #include <net/ip.h>
127 #include <net/mpls.h>
128 #include <linux/ipv6.h>
129 #include <linux/in.h>
130 #include <linux/jhash.h>
131 #include <linux/random.h>
132 #include <trace/events/napi.h>
133 #include <trace/events/net.h>
134 #include <trace/events/skb.h>
135 #include <linux/pci.h>
136 #include <linux/inetdevice.h>
137 #include <linux/cpu_rmap.h>
138 #include <linux/static_key.h>
139 #include <linux/hashtable.h>
140 #include <linux/vmalloc.h>
141 #include <linux/if_macvlan.h>
142 #include <linux/errqueue.h>
143 #include <linux/hrtimer.h>
144 #include <linux/netfilter_ingress.h>
145 #include <linux/crash_dump.h>
146 #include <linux/sctp.h>
147 #include <net/udp_tunnel.h>
148 #include <linux/net_namespace.h>
149 
150 #include "net-sysfs.h"
151 
152 /* Instead of increasing this, you should create a hash table. */
153 #define MAX_GRO_SKBS 8
154 
155 /* This should be increased if a protocol with a bigger head is added. */
156 #define GRO_MAX_HEAD (MAX_HEADER + 128)
157 
158 static DEFINE_SPINLOCK(ptype_lock);
159 static DEFINE_SPINLOCK(offload_lock);
160 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
161 struct list_head ptype_all __read_mostly;       /* Taps */
162 static struct list_head offload_base __read_mostly;
163 
164 static int netif_rx_internal(struct sk_buff *skb);
165 static int call_netdevice_notifiers_info(unsigned long val,
166                                          struct netdev_notifier_info *info);
167 static struct napi_struct *napi_by_id(unsigned int napi_id);
168 
169 /*
170  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
171  * semaphore.
172  *
173  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
174  *
175  * Writers must hold the rtnl semaphore while they loop through the
176  * dev_base_head list, and hold dev_base_lock for writing when they do the
177  * actual updates.  This allows pure readers to access the list even
178  * while a writer is preparing to update it.
179  *
180  * To put it another way, dev_base_lock is held for writing only to
181  * protect against pure readers; the rtnl semaphore provides the
182  * protection against other writers.
183  *
184  * See, for example usages, register_netdevice() and
185  * unregister_netdevice(), which must be called with the rtnl
186  * semaphore held.
187  */
188 DEFINE_RWLOCK(dev_base_lock);
189 EXPORT_SYMBOL(dev_base_lock);
190 
191 static DEFINE_MUTEX(ifalias_mutex);
192 
193 /* protects napi_hash addition/deletion and napi_gen_id */
194 static DEFINE_SPINLOCK(napi_hash_lock);
195 
196 static unsigned int napi_gen_id = NR_CPUS;
197 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
198 
199 static seqcount_t devnet_rename_seq;
200 
201 static inline void dev_base_seq_inc(struct net *net)
202 {
203         while (++net->dev_base_seq == 0)
204                 ;
205 }
206 
207 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
208 {
209         unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
210 
211         return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
212 }
213 
214 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
215 {
216         return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
217 }
218 
219 static inline void rps_lock(struct softnet_data *sd)
220 {
221 #ifdef CONFIG_RPS
222         spin_lock(&sd->input_pkt_queue.lock);
223 #endif
224 }
225 
226 static inline void rps_unlock(struct softnet_data *sd)
227 {
228 #ifdef CONFIG_RPS
229         spin_unlock(&sd->input_pkt_queue.lock);
230 #endif
231 }
232 
233 /* Device list insertion */
234 static void list_netdevice(struct net_device *dev)
235 {
236         struct net *net = dev_net(dev);
237 
238         ASSERT_RTNL();
239 
240         write_lock_bh(&dev_base_lock);
241         list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
242         hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
243         hlist_add_head_rcu(&dev->index_hlist,
244                            dev_index_hash(net, dev->ifindex));
245         write_unlock_bh(&dev_base_lock);
246 
247         dev_base_seq_inc(net);
248 }
249 
250 /* Device list removal
251  * caller must respect a RCU grace period before freeing/reusing dev
252  */
253 static void unlist_netdevice(struct net_device *dev)
254 {
255         ASSERT_RTNL();
256 
257         /* Unlink dev from the device chain */
258         write_lock_bh(&dev_base_lock);
259         list_del_rcu(&dev->dev_list);
260         hlist_del_rcu(&dev->name_hlist);
261         hlist_del_rcu(&dev->index_hlist);
262         write_unlock_bh(&dev_base_lock);
263 
264         dev_base_seq_inc(dev_net(dev));
265 }
266 
267 /*
268  *      Our notifier list
269  */
270 
271 static RAW_NOTIFIER_HEAD(netdev_chain);
272 
273 /*
274  *      Device drivers call our routines to queue packets here. We empty the
275  *      queue in the local softnet handler.
276  */
277 
278 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
279 EXPORT_PER_CPU_SYMBOL(softnet_data);
280 
281 #ifdef CONFIG_LOCKDEP
282 /*
283  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
284  * according to dev->type
285  */
286 static const unsigned short netdev_lock_type[] = {
287          ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
288          ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
289          ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
290          ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
291          ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
292          ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
293          ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
294          ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
295          ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
296          ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
297          ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
298          ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
299          ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
300          ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
301          ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
302 
303 static const char *const netdev_lock_name[] = {
304         "_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
305         "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
306         "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
307         "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
308         "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
309         "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
310         "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
311         "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
312         "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
313         "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
314         "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
315         "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
316         "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
317         "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
318         "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
319 
320 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
321 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
322 
323 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
324 {
325         int i;
326 
327         for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
328                 if (netdev_lock_type[i] == dev_type)
329                         return i;
330         /* the last key is used by default */
331         return ARRAY_SIZE(netdev_lock_type) - 1;
332 }
333 
334 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
335                                                  unsigned short dev_type)
336 {
337         int i;
338 
339         i = netdev_lock_pos(dev_type);
340         lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
341                                    netdev_lock_name[i]);
342 }
343 
344 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
345 {
346         int i;
347 
348         i = netdev_lock_pos(dev->type);
349         lockdep_set_class_and_name(&dev->addr_list_lock,
350                                    &netdev_addr_lock_key[i],
351                                    netdev_lock_name[i]);
352 }
353 #else
354 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
355                                                  unsigned short dev_type)
356 {
357 }
358 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
359 {
360 }
361 #endif
362 
363 /*******************************************************************************
364  *
365  *              Protocol management and registration routines
366  *
367  *******************************************************************************/
368 
369 
370 /*
371  *      Add a protocol ID to the list. Now that the input handler is
372  *      smarter we can dispense with all the messy stuff that used to be
373  *      here.
374  *
375  *      BEWARE!!! Protocol handlers, mangling input packets,
376  *      MUST BE last in hash buckets and checking protocol handlers
377  *      MUST start from promiscuous ptype_all chain in net_bh.
378  *      It is true now, do not change it.
379  *      Explanation follows: if protocol handler, mangling packet, will
380  *      be the first on list, it is not able to sense, that packet
381  *      is cloned and should be copied-on-write, so that it will
382  *      change it and subsequent readers will get broken packet.
383  *                                                      --ANK (980803)
384  */
385 
386 static inline struct list_head *ptype_head(const struct packet_type *pt)
387 {
388         if (pt->type == htons(ETH_P_ALL))
389                 return pt->dev ? &pt->dev->ptype_all : &ptype_all;
390         else
391                 return pt->dev ? &pt->dev->ptype_specific :
392                                  &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
393 }
394 
395 /**
396  *      dev_add_pack - add packet handler
397  *      @pt: packet type declaration
398  *
399  *      Add a protocol handler to the networking stack. The passed &packet_type
400  *      is linked into kernel lists and may not be freed until it has been
401  *      removed from the kernel lists.
402  *
403  *      This call does not sleep therefore it can not
404  *      guarantee all CPU's that are in middle of receiving packets
405  *      will see the new packet type (until the next received packet).
406  */
407 
408 void dev_add_pack(struct packet_type *pt)
409 {
410         struct list_head *head = ptype_head(pt);
411 
412         spin_lock(&ptype_lock);
413         list_add_rcu(&pt->list, head);
414         spin_unlock(&ptype_lock);
415 }
416 EXPORT_SYMBOL(dev_add_pack);
417 
418 /**
419  *      __dev_remove_pack        - remove packet handler
420  *      @pt: packet type declaration
421  *
422  *      Remove a protocol handler that was previously added to the kernel
423  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
424  *      from the kernel lists and can be freed or reused once this function
425  *      returns.
426  *
427  *      The packet type might still be in use by receivers
428  *      and must not be freed until after all the CPU's have gone
429  *      through a quiescent state.
430  */
431 void __dev_remove_pack(struct packet_type *pt)
432 {
433         struct list_head *head = ptype_head(pt);
434         struct packet_type *pt1;
435 
436         spin_lock(&ptype_lock);
437 
438         list_for_each_entry(pt1, head, list) {
439                 if (pt == pt1) {
440                         list_del_rcu(&pt->list);
441                         goto out;
442                 }
443         }
444 
445         pr_warn("dev_remove_pack: %p not found\n", pt);
446 out:
447         spin_unlock(&ptype_lock);
448 }
449 EXPORT_SYMBOL(__dev_remove_pack);
450 
451 /**
452  *      dev_remove_pack  - remove packet handler
453  *      @pt: packet type declaration
454  *
455  *      Remove a protocol handler that was previously added to the kernel
456  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
457  *      from the kernel lists and can be freed or reused once this function
458  *      returns.
459  *
460  *      This call sleeps to guarantee that no CPU is looking at the packet
461  *      type after return.
462  */
463 void dev_remove_pack(struct packet_type *pt)
464 {
465         __dev_remove_pack(pt);
466 
467         synchronize_net();
468 }
469 EXPORT_SYMBOL(dev_remove_pack);
470 
471 
472 /**
473  *      dev_add_offload - register offload handlers
474  *      @po: protocol offload declaration
475  *
476  *      Add protocol offload handlers to the networking stack. The passed
477  *      &proto_offload is linked into kernel lists and may not be freed until
478  *      it has been removed from the kernel lists.
479  *
480  *      This call does not sleep therefore it can not
481  *      guarantee all CPU's that are in middle of receiving packets
482  *      will see the new offload handlers (until the next received packet).
483  */
484 void dev_add_offload(struct packet_offload *po)
485 {
486         struct packet_offload *elem;
487 
488         spin_lock(&offload_lock);
489         list_for_each_entry(elem, &offload_base, list) {
490                 if (po->priority < elem->priority)
491                         break;
492         }
493         list_add_rcu(&po->list, elem->list.prev);
494         spin_unlock(&offload_lock);
495 }
496 EXPORT_SYMBOL(dev_add_offload);
497 
498 /**
499  *      __dev_remove_offload     - remove offload handler
500  *      @po: packet offload declaration
501  *
502  *      Remove a protocol offload handler that was previously added to the
503  *      kernel offload handlers by dev_add_offload(). The passed &offload_type
504  *      is removed from the kernel lists and can be freed or reused once this
505  *      function returns.
506  *
507  *      The packet type might still be in use by receivers
508  *      and must not be freed until after all the CPU's have gone
509  *      through a quiescent state.
510  */
511 static void __dev_remove_offload(struct packet_offload *po)
512 {
513         struct list_head *head = &offload_base;
514         struct packet_offload *po1;
515 
516         spin_lock(&offload_lock);
517 
518         list_for_each_entry(po1, head, list) {
519                 if (po == po1) {
520                         list_del_rcu(&po->list);
521                         goto out;
522                 }
523         }
524 
525         pr_warn("dev_remove_offload: %p not found\n", po);
526 out:
527         spin_unlock(&offload_lock);
528 }
529 
530 /**
531  *      dev_remove_offload       - remove packet offload handler
532  *      @po: packet offload declaration
533  *
534  *      Remove a packet offload handler that was previously added to the kernel
535  *      offload handlers by dev_add_offload(). The passed &offload_type is
536  *      removed from the kernel lists and can be freed or reused once this
537  *      function returns.
538  *
539  *      This call sleeps to guarantee that no CPU is looking at the packet
540  *      type after return.
541  */
542 void dev_remove_offload(struct packet_offload *po)
543 {
544         __dev_remove_offload(po);
545 
546         synchronize_net();
547 }
548 EXPORT_SYMBOL(dev_remove_offload);
549 
550 /******************************************************************************
551  *
552  *                    Device Boot-time Settings Routines
553  *
554  ******************************************************************************/
555 
556 /* Boot time configuration table */
557 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
558 
559 /**
560  *      netdev_boot_setup_add   - add new setup entry
561  *      @name: name of the device
562  *      @map: configured settings for the device
563  *
564  *      Adds new setup entry to the dev_boot_setup list.  The function
565  *      returns 0 on error and 1 on success.  This is a generic routine to
566  *      all netdevices.
567  */
568 static int netdev_boot_setup_add(char *name, struct ifmap *map)
569 {
570         struct netdev_boot_setup *s;
571         int i;
572 
573         s = dev_boot_setup;
574         for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
575                 if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
576                         memset(s[i].name, 0, sizeof(s[i].name));
577                         strlcpy(s[i].name, name, IFNAMSIZ);
578                         memcpy(&s[i].map, map, sizeof(s[i].map));
579                         break;
580                 }
581         }
582 
583         return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
584 }
585 
586 /**
587  * netdev_boot_setup_check      - check boot time settings
588  * @dev: the netdevice
589  *
590  * Check boot time settings for the device.
591  * The found settings are set for the device to be used
592  * later in the device probing.
593  * Returns 0 if no settings found, 1 if they are.
594  */
595 int netdev_boot_setup_check(struct net_device *dev)
596 {
597         struct netdev_boot_setup *s = dev_boot_setup;
598         int i;
599 
600         for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
601                 if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
602                     !strcmp(dev->name, s[i].name)) {
603                         dev->irq = s[i].map.irq;
604                         dev->base_addr = s[i].map.base_addr;
605                         dev->mem_start = s[i].map.mem_start;
606                         dev->mem_end = s[i].map.mem_end;
607                         return 1;
608                 }
609         }
610         return 0;
611 }
612 EXPORT_SYMBOL(netdev_boot_setup_check);
613 
614 
615 /**
616  * netdev_boot_base     - get address from boot time settings
617  * @prefix: prefix for network device
618  * @unit: id for network device
619  *
620  * Check boot time settings for the base address of device.
621  * The found settings are set for the device to be used
622  * later in the device probing.
623  * Returns 0 if no settings found.
624  */
625 unsigned long netdev_boot_base(const char *prefix, int unit)
626 {
627         const struct netdev_boot_setup *s = dev_boot_setup;
628         char name[IFNAMSIZ];
629         int i;
630 
631         sprintf(name, "%s%d", prefix, unit);
632 
633         /*
634          * If device already registered then return base of 1
635          * to indicate not to probe for this interface
636          */
637         if (__dev_get_by_name(&init_net, name))
638                 return 1;
639 
640         for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
641                 if (!strcmp(name, s[i].name))
642                         return s[i].map.base_addr;
643         return 0;
644 }
645 
646 /*
647  * Saves at boot time configured settings for any netdevice.
648  */
649 int __init netdev_boot_setup(char *str)
650 {
651         int ints[5];
652         struct ifmap map;
653 
654         str = get_options(str, ARRAY_SIZE(ints), ints);
655         if (!str || !*str)
656                 return 0;
657 
658         /* Save settings */
659         memset(&map, 0, sizeof(map));
660         if (ints[0] > 0)
661                 map.irq = ints[1];
662         if (ints[0] > 1)
663                 map.base_addr = ints[2];
664         if (ints[0] > 2)
665                 map.mem_start = ints[3];
666         if (ints[0] > 3)
667                 map.mem_end = ints[4];
668 
669         /* Add new entry to the list */
670         return netdev_boot_setup_add(str, &map);
671 }
672 
673 __setup("netdev=", netdev_boot_setup);
674 
675 /*******************************************************************************
676  *
677  *                          Device Interface Subroutines
678  *
679  *******************************************************************************/
680 
681 /**
682  *      dev_get_iflink  - get 'iflink' value of a interface
683  *      @dev: targeted interface
684  *
685  *      Indicates the ifindex the interface is linked to.
686  *      Physical interfaces have the same 'ifindex' and 'iflink' values.
687  */
688 
689 int dev_get_iflink(const struct net_device *dev)
690 {
691         if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
692                 return dev->netdev_ops->ndo_get_iflink(dev);
693 
694         return dev->ifindex;
695 }
696 EXPORT_SYMBOL(dev_get_iflink);
697 
698 /**
699  *      dev_fill_metadata_dst - Retrieve tunnel egress information.
700  *      @dev: targeted interface
701  *      @skb: The packet.
702  *
703  *      For better visibility of tunnel traffic OVS needs to retrieve
704  *      egress tunnel information for a packet. Following API allows
705  *      user to get this info.
706  */
707 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
708 {
709         struct ip_tunnel_info *info;
710 
711         if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
712                 return -EINVAL;
713 
714         info = skb_tunnel_info_unclone(skb);
715         if (!info)
716                 return -ENOMEM;
717         if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
718                 return -EINVAL;
719 
720         return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
721 }
722 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
723 
724 /**
725  *      __dev_get_by_name       - find a device by its name
726  *      @net: the applicable net namespace
727  *      @name: name to find
728  *
729  *      Find an interface by name. Must be called under RTNL semaphore
730  *      or @dev_base_lock. If the name is found a pointer to the device
731  *      is returned. If the name is not found then %NULL is returned. The
732  *      reference counters are not incremented so the caller must be
733  *      careful with locks.
734  */
735 
736 struct net_device *__dev_get_by_name(struct net *net, const char *name)
737 {
738         struct net_device *dev;
739         struct hlist_head *head = dev_name_hash(net, name);
740 
741         hlist_for_each_entry(dev, head, name_hlist)
742                 if (!strncmp(dev->name, name, IFNAMSIZ))
743                         return dev;
744 
745         return NULL;
746 }
747 EXPORT_SYMBOL(__dev_get_by_name);
748 
749 /**
750  * dev_get_by_name_rcu  - find a device by its name
751  * @net: the applicable net namespace
752  * @name: name to find
753  *
754  * Find an interface by name.
755  * If the name is found a pointer to the device is returned.
756  * If the name is not found then %NULL is returned.
757  * The reference counters are not incremented so the caller must be
758  * careful with locks. The caller must hold RCU lock.
759  */
760 
761 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
762 {
763         struct net_device *dev;
764         struct hlist_head *head = dev_name_hash(net, name);
765 
766         hlist_for_each_entry_rcu(dev, head, name_hlist)
767                 if (!strncmp(dev->name, name, IFNAMSIZ))
768                         return dev;
769 
770         return NULL;
771 }
772 EXPORT_SYMBOL(dev_get_by_name_rcu);
773 
774 /**
775  *      dev_get_by_name         - find a device by its name
776  *      @net: the applicable net namespace
777  *      @name: name to find
778  *
779  *      Find an interface by name. This can be called from any
780  *      context and does its own locking. The returned handle has
781  *      the usage count incremented and the caller must use dev_put() to
782  *      release it when it is no longer needed. %NULL is returned if no
783  *      matching device is found.
784  */
785 
786 struct net_device *dev_get_by_name(struct net *net, const char *name)
787 {
788         struct net_device *dev;
789 
790         rcu_read_lock();
791         dev = dev_get_by_name_rcu(net, name);
792         if (dev)
793                 dev_hold(dev);
794         rcu_read_unlock();
795         return dev;
796 }
797 EXPORT_SYMBOL(dev_get_by_name);
798 
799 /**
800  *      __dev_get_by_index - find a device by its ifindex
801  *      @net: the applicable net namespace
802  *      @ifindex: index of device
803  *
804  *      Search for an interface by index. Returns %NULL if the device
805  *      is not found or a pointer to the device. The device has not
806  *      had its reference counter increased so the caller must be careful
807  *      about locking. The caller must hold either the RTNL semaphore
808  *      or @dev_base_lock.
809  */
810 
811 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
812 {
813         struct net_device *dev;
814         struct hlist_head *head = dev_index_hash(net, ifindex);
815 
816         hlist_for_each_entry(dev, head, index_hlist)
817                 if (dev->ifindex == ifindex)
818                         return dev;
819 
820         return NULL;
821 }
822 EXPORT_SYMBOL(__dev_get_by_index);
823 
824 /**
825  *      dev_get_by_index_rcu - find a device by its ifindex
826  *      @net: the applicable net namespace
827  *      @ifindex: index of device
828  *
829  *      Search for an interface by index. Returns %NULL if the device
830  *      is not found or a pointer to the device. The device has not
831  *      had its reference counter increased so the caller must be careful
832  *      about locking. The caller must hold RCU lock.
833  */
834 
835 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
836 {
837         struct net_device *dev;
838         struct hlist_head *head = dev_index_hash(net, ifindex);
839 
840         hlist_for_each_entry_rcu(dev, head, index_hlist)
841                 if (dev->ifindex == ifindex)
842                         return dev;
843 
844         return NULL;
845 }
846 EXPORT_SYMBOL(dev_get_by_index_rcu);
847 
848 
849 /**
850  *      dev_get_by_index - find a device by its ifindex
851  *      @net: the applicable net namespace
852  *      @ifindex: index of device
853  *
854  *      Search for an interface by index. Returns NULL if the device
855  *      is not found or a pointer to the device. The device returned has
856  *      had a reference added and the pointer is safe until the user calls
857  *      dev_put to indicate they have finished with it.
858  */
859 
860 struct net_device *dev_get_by_index(struct net *net, int ifindex)
861 {
862         struct net_device *dev;
863 
864         rcu_read_lock();
865         dev = dev_get_by_index_rcu(net, ifindex);
866         if (dev)
867                 dev_hold(dev);
868         rcu_read_unlock();
869         return dev;
870 }
871 EXPORT_SYMBOL(dev_get_by_index);
872 
873 /**
874  *      dev_get_by_napi_id - find a device by napi_id
875  *      @napi_id: ID of the NAPI struct
876  *
877  *      Search for an interface by NAPI ID. Returns %NULL if the device
878  *      is not found or a pointer to the device. The device has not had
879  *      its reference counter increased so the caller must be careful
880  *      about locking. The caller must hold RCU lock.
881  */
882 
883 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
884 {
885         struct napi_struct *napi;
886 
887         WARN_ON_ONCE(!rcu_read_lock_held());
888 
889         if (napi_id < MIN_NAPI_ID)
890                 return NULL;
891 
892         napi = napi_by_id(napi_id);
893 
894         return napi ? napi->dev : NULL;
895 }
896 EXPORT_SYMBOL(dev_get_by_napi_id);
897 
898 /**
899  *      netdev_get_name - get a netdevice name, knowing its ifindex.
900  *      @net: network namespace
901  *      @name: a pointer to the buffer where the name will be stored.
902  *      @ifindex: the ifindex of the interface to get the name from.
903  *
904  *      The use of raw_seqcount_begin() and cond_resched() before
905  *      retrying is required as we want to give the writers a chance
906  *      to complete when CONFIG_PREEMPT is not set.
907  */
908 int netdev_get_name(struct net *net, char *name, int ifindex)
909 {
910         struct net_device *dev;
911         unsigned int seq;
912 
913 retry:
914         seq = raw_seqcount_begin(&devnet_rename_seq);
915         rcu_read_lock();
916         dev = dev_get_by_index_rcu(net, ifindex);
917         if (!dev) {
918                 rcu_read_unlock();
919                 return -ENODEV;
920         }
921 
922         strcpy(name, dev->name);
923         rcu_read_unlock();
924         if (read_seqcount_retry(&devnet_rename_seq, seq)) {
925                 cond_resched();
926                 goto retry;
927         }
928 
929         return 0;
930 }
931 
932 /**
933  *      dev_getbyhwaddr_rcu - find a device by its hardware address
934  *      @net: the applicable net namespace
935  *      @type: media type of device
936  *      @ha: hardware address
937  *
938  *      Search for an interface by MAC address. Returns NULL if the device
939  *      is not found or a pointer to the device.
940  *      The caller must hold RCU or RTNL.
941  *      The returned device has not had its ref count increased
942  *      and the caller must therefore be careful about locking
943  *
944  */
945 
946 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
947                                        const char *ha)
948 {
949         struct net_device *dev;
950 
951         for_each_netdev_rcu(net, dev)
952                 if (dev->type == type &&
953                     !memcmp(dev->dev_addr, ha, dev->addr_len))
954                         return dev;
955 
956         return NULL;
957 }
958 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
959 
960 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
961 {
962         struct net_device *dev;
963 
964         ASSERT_RTNL();
965         for_each_netdev(net, dev)
966                 if (dev->type == type)
967                         return dev;
968 
969         return NULL;
970 }
971 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
972 
973 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
974 {
975         struct net_device *dev, *ret = NULL;
976 
977         rcu_read_lock();
978         for_each_netdev_rcu(net, dev)
979                 if (dev->type == type) {
980                         dev_hold(dev);
981                         ret = dev;
982                         break;
983                 }
984         rcu_read_unlock();
985         return ret;
986 }
987 EXPORT_SYMBOL(dev_getfirstbyhwtype);
988 
989 /**
990  *      __dev_get_by_flags - find any device with given flags
991  *      @net: the applicable net namespace
992  *      @if_flags: IFF_* values
993  *      @mask: bitmask of bits in if_flags to check
994  *
995  *      Search for any interface with the given flags. Returns NULL if a device
996  *      is not found or a pointer to the device. Must be called inside
997  *      rtnl_lock(), and result refcount is unchanged.
998  */
999 
1000 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
1001                                       unsigned short mask)
1002 {
1003         struct net_device *dev, *ret;
1004 
1005         ASSERT_RTNL();
1006 
1007         ret = NULL;
1008         for_each_netdev(net, dev) {
1009                 if (((dev->flags ^ if_flags) & mask) == 0) {
1010                         ret = dev;
1011                         break;
1012                 }
1013         }
1014         return ret;
1015 }
1016 EXPORT_SYMBOL(__dev_get_by_flags);
1017 
1018 /**
1019  *      dev_valid_name - check if name is okay for network device
1020  *      @name: name string
1021  *
1022  *      Network device names need to be valid file names to
1023  *      to allow sysfs to work.  We also disallow any kind of
1024  *      whitespace.
1025  */
1026 bool dev_valid_name(const char *name)
1027 {
1028         if (*name == '\0')
1029                 return false;
1030         if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1031                 return false;
1032         if (!strcmp(name, ".") || !strcmp(name, ".."))
1033                 return false;
1034 
1035         while (*name) {
1036                 if (*name == '/' || *name == ':' || isspace(*name))
1037                         return false;
1038                 name++;
1039         }
1040         return true;
1041 }
1042 EXPORT_SYMBOL(dev_valid_name);
1043 
1044 /**
1045  *      __dev_alloc_name - allocate a name for a device
1046  *      @net: network namespace to allocate the device name in
1047  *      @name: name format string
1048  *      @buf:  scratch buffer and result name string
1049  *
1050  *      Passed a format string - eg "lt%d" it will try and find a suitable
1051  *      id. It scans list of devices to build up a free map, then chooses
1052  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1053  *      while allocating the name and adding the device in order to avoid
1054  *      duplicates.
1055  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1056  *      Returns the number of the unit assigned or a negative errno code.
1057  */
1058 
1059 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1060 {
1061         int i = 0;
1062         const char *p;
1063         const int max_netdevices = 8*PAGE_SIZE;
1064         unsigned long *inuse;
1065         struct net_device *d;
1066 
1067         if (!dev_valid_name(name))
1068                 return -EINVAL;
1069 
1070         p = strchr(name, '%');
1071         if (p) {
1072                 /*
1073                  * Verify the string as this thing may have come from
1074                  * the user.  There must be either one "%d" and no other "%"
1075                  * characters.
1076                  */
1077                 if (p[1] != 'd' || strchr(p + 2, '%'))
1078                         return -EINVAL;
1079 
1080                 /* Use one page as a bit array of possible slots */
1081                 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1082                 if (!inuse)
1083                         return -ENOMEM;
1084 
1085                 for_each_netdev(net, d) {
1086                         if (!sscanf(d->name, name, &i))
1087                                 continue;
1088                         if (i < 0 || i >= max_netdevices)
1089                                 continue;
1090 
1091                         /*  avoid cases where sscanf is not exact inverse of printf */
1092                         snprintf(buf, IFNAMSIZ, name, i);
1093                         if (!strncmp(buf, d->name, IFNAMSIZ))
1094                                 set_bit(i, inuse);
1095                 }
1096 
1097                 i = find_first_zero_bit(inuse, max_netdevices);
1098                 free_page((unsigned long) inuse);
1099         }
1100 
1101         snprintf(buf, IFNAMSIZ, name, i);
1102         if (!__dev_get_by_name(net, buf))
1103                 return i;
1104 
1105         /* It is possible to run out of possible slots
1106          * when the name is long and there isn't enough space left
1107          * for the digits, or if all bits are used.
1108          */
1109         return -ENFILE;
1110 }
1111 
1112 static int dev_alloc_name_ns(struct net *net,
1113                              struct net_device *dev,
1114                              const char *name)
1115 {
1116         char buf[IFNAMSIZ];
1117         int ret;
1118 
1119         BUG_ON(!net);
1120         ret = __dev_alloc_name(net, name, buf);
1121         if (ret >= 0)
1122                 strlcpy(dev->name, buf, IFNAMSIZ);
1123         return ret;
1124 }
1125 
1126 /**
1127  *      dev_alloc_name - allocate a name for a device
1128  *      @dev: device
1129  *      @name: name format string
1130  *
1131  *      Passed a format string - eg "lt%d" it will try and find a suitable
1132  *      id. It scans list of devices to build up a free map, then chooses
1133  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1134  *      while allocating the name and adding the device in order to avoid
1135  *      duplicates.
1136  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1137  *      Returns the number of the unit assigned or a negative errno code.
1138  */
1139 
1140 int dev_alloc_name(struct net_device *dev, const char *name)
1141 {
1142         return dev_alloc_name_ns(dev_net(dev), dev, name);
1143 }
1144 EXPORT_SYMBOL(dev_alloc_name);
1145 
1146 int dev_get_valid_name(struct net *net, struct net_device *dev,
1147                        const char *name)
1148 {
1149         BUG_ON(!net);
1150 
1151         if (!dev_valid_name(name))
1152                 return -EINVAL;
1153 
1154         if (strchr(name, '%'))
1155                 return dev_alloc_name_ns(net, dev, name);
1156         else if (__dev_get_by_name(net, name))
1157                 return -EEXIST;
1158         else if (dev->name != name)
1159                 strlcpy(dev->name, name, IFNAMSIZ);
1160 
1161         return 0;
1162 }
1163 EXPORT_SYMBOL(dev_get_valid_name);
1164 
1165 /**
1166  *      dev_change_name - change name of a device
1167  *      @dev: device
1168  *      @newname: name (or format string) must be at least IFNAMSIZ
1169  *
1170  *      Change name of a device, can pass format strings "eth%d".
1171  *      for wildcarding.
1172  */
1173 int dev_change_name(struct net_device *dev, const char *newname)
1174 {
1175         unsigned char old_assign_type;
1176         char oldname[IFNAMSIZ];
1177         int err = 0;
1178         int ret;
1179         struct net *net;
1180 
1181         ASSERT_RTNL();
1182         BUG_ON(!dev_net(dev));
1183 
1184         net = dev_net(dev);
1185         if (dev->flags & IFF_UP)
1186                 return -EBUSY;
1187 
1188         write_seqcount_begin(&devnet_rename_seq);
1189 
1190         if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1191                 write_seqcount_end(&devnet_rename_seq);
1192                 return 0;
1193         }
1194 
1195         memcpy(oldname, dev->name, IFNAMSIZ);
1196 
1197         err = dev_get_valid_name(net, dev, newname);
1198         if (err < 0) {
1199                 write_seqcount_end(&devnet_rename_seq);
1200                 return err;
1201         }
1202 
1203         if (oldname[0] && !strchr(oldname, '%'))
1204                 netdev_info(dev, "renamed from %s\n", oldname);
1205 
1206         old_assign_type = dev->name_assign_type;
1207         dev->name_assign_type = NET_NAME_RENAMED;
1208 
1209 rollback:
1210         ret = device_rename(&dev->dev, dev->name);
1211         if (ret) {
1212                 memcpy(dev->name, oldname, IFNAMSIZ);
1213                 dev->name_assign_type = old_assign_type;
1214                 write_seqcount_end(&devnet_rename_seq);
1215                 return ret;
1216         }
1217 
1218         write_seqcount_end(&devnet_rename_seq);
1219 
1220         netdev_adjacent_rename_links(dev, oldname);
1221 
1222         write_lock_bh(&dev_base_lock);
1223         hlist_del_rcu(&dev->name_hlist);
1224         write_unlock_bh(&dev_base_lock);
1225 
1226         synchronize_rcu();
1227 
1228         write_lock_bh(&dev_base_lock);
1229         hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1230         write_unlock_bh(&dev_base_lock);
1231 
1232         ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1233         ret = notifier_to_errno(ret);
1234 
1235         if (ret) {
1236                 /* err >= 0 after dev_alloc_name() or stores the first errno */
1237                 if (err >= 0) {
1238                         err = ret;
1239                         write_seqcount_begin(&devnet_rename_seq);
1240                         memcpy(dev->name, oldname, IFNAMSIZ);
1241                         memcpy(oldname, newname, IFNAMSIZ);
1242                         dev->name_assign_type = old_assign_type;
1243                         old_assign_type = NET_NAME_RENAMED;
1244                         goto rollback;
1245                 } else {
1246                         pr_err("%s: name change rollback failed: %d\n",
1247                                dev->name, ret);
1248                 }
1249         }
1250 
1251         return err;
1252 }
1253 
1254 /**
1255  *      dev_set_alias - change ifalias of a device
1256  *      @dev: device
1257  *      @alias: name up to IFALIASZ
1258  *      @len: limit of bytes to copy from info
1259  *
1260  *      Set ifalias for a device,
1261  */
1262 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1263 {
1264         struct dev_ifalias *new_alias = NULL;
1265 
1266         if (len >= IFALIASZ)
1267                 return -EINVAL;
1268 
1269         if (len) {
1270                 new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1271                 if (!new_alias)
1272                         return -ENOMEM;
1273 
1274                 memcpy(new_alias->ifalias, alias, len);
1275                 new_alias->ifalias[len] = 0;
1276         }
1277 
1278         mutex_lock(&ifalias_mutex);
1279         rcu_swap_protected(dev->ifalias, new_alias,
1280                            mutex_is_locked(&ifalias_mutex));
1281         mutex_unlock(&ifalias_mutex);
1282 
1283         if (new_alias)
1284                 kfree_rcu(new_alias, rcuhead);
1285 
1286         return len;
1287 }
1288 
1289 /**
1290  *      dev_get_alias - get ifalias of a device
1291  *      @dev: device
1292  *      @name: buffer to store name of ifalias
1293  *      @len: size of buffer
1294  *
1295  *      get ifalias for a device.  Caller must make sure dev cannot go
1296  *      away,  e.g. rcu read lock or own a reference count to device.
1297  */
1298 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1299 {
1300         const struct dev_ifalias *alias;
1301         int ret = 0;
1302 
1303         rcu_read_lock();
1304         alias = rcu_dereference(dev->ifalias);
1305         if (alias)
1306                 ret = snprintf(name, len, "%s", alias->ifalias);
1307         rcu_read_unlock();
1308 
1309         return ret;
1310 }
1311 
1312 /**
1313  *      netdev_features_change - device changes features
1314  *      @dev: device to cause notification
1315  *
1316  *      Called to indicate a device has changed features.
1317  */
1318 void netdev_features_change(struct net_device *dev)
1319 {
1320         call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1321 }
1322 EXPORT_SYMBOL(netdev_features_change);
1323 
1324 /**
1325  *      netdev_state_change - device changes state
1326  *      @dev: device to cause notification
1327  *
1328  *      Called to indicate a device has changed state. This function calls
1329  *      the notifier chains for netdev_chain and sends a NEWLINK message
1330  *      to the routing socket.
1331  */
1332 void netdev_state_change(struct net_device *dev)
1333 {
1334         if (dev->flags & IFF_UP) {
1335                 struct netdev_notifier_change_info change_info = {
1336                         .info.dev = dev,
1337                 };
1338 
1339                 call_netdevice_notifiers_info(NETDEV_CHANGE,
1340                                               &change_info.info);
1341                 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
1342         }
1343 }
1344 EXPORT_SYMBOL(netdev_state_change);
1345 
1346 /**
1347  * netdev_notify_peers - notify network peers about existence of @dev
1348  * @dev: network device
1349  *
1350  * Generate traffic such that interested network peers are aware of
1351  * @dev, such as by generating a gratuitous ARP. This may be used when
1352  * a device wants to inform the rest of the network about some sort of
1353  * reconfiguration such as a failover event or virtual machine
1354  * migration.
1355  */
1356 void netdev_notify_peers(struct net_device *dev)
1357 {
1358         rtnl_lock();
1359         call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1360         call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1361         rtnl_unlock();
1362 }
1363 EXPORT_SYMBOL(netdev_notify_peers);
1364 
1365 static int __dev_open(struct net_device *dev)
1366 {
1367         const struct net_device_ops *ops = dev->netdev_ops;
1368         int ret;
1369 
1370         ASSERT_RTNL();
1371 
1372         if (!netif_device_present(dev))
1373                 return -ENODEV;
1374 
1375         /* Block netpoll from trying to do any rx path servicing.
1376          * If we don't do this there is a chance ndo_poll_controller
1377          * or ndo_poll may be running while we open the device
1378          */
1379         netpoll_poll_disable(dev);
1380 
1381         ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1382         ret = notifier_to_errno(ret);
1383         if (ret)
1384                 return ret;
1385 
1386         set_bit(__LINK_STATE_START, &dev->state);
1387 
1388         if (ops->ndo_validate_addr)
1389                 ret = ops->ndo_validate_addr(dev);
1390 
1391         if (!ret && ops->ndo_open)
1392                 ret = ops->ndo_open(dev);
1393 
1394         netpoll_poll_enable(dev);
1395 
1396         if (ret)
1397                 clear_bit(__LINK_STATE_START, &dev->state);
1398         else {
1399                 dev->flags |= IFF_UP;
1400                 dev_set_rx_mode(dev);
1401                 dev_activate(dev);
1402                 add_device_randomness(dev->dev_addr, dev->addr_len);
1403         }
1404 
1405         return ret;
1406 }
1407 
1408 /**
1409  *      dev_open        - prepare an interface for use.
1410  *      @dev:   device to open
1411  *
1412  *      Takes a device from down to up state. The device's private open
1413  *      function is invoked and then the multicast lists are loaded. Finally
1414  *      the device is moved into the up state and a %NETDEV_UP message is
1415  *      sent to the netdev notifier chain.
1416  *
1417  *      Calling this function on an active interface is a nop. On a failure
1418  *      a negative errno code is returned.
1419  */
1420 int dev_open(struct net_device *dev)
1421 {
1422         int ret;
1423 
1424         if (dev->flags & IFF_UP)
1425                 return 0;
1426 
1427         ret = __dev_open(dev);
1428         if (ret < 0)
1429                 return ret;
1430 
1431         rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1432         call_netdevice_notifiers(NETDEV_UP, dev);
1433 
1434         return ret;
1435 }
1436 EXPORT_SYMBOL(dev_open);
1437 
1438 static void __dev_close_many(struct list_head *head)
1439 {
1440         struct net_device *dev;
1441 
1442         ASSERT_RTNL();
1443         might_sleep();
1444 
1445         list_for_each_entry(dev, head, close_list) {
1446                 /* Temporarily disable netpoll until the interface is down */
1447                 netpoll_poll_disable(dev);
1448 
1449                 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1450 
1451                 clear_bit(__LINK_STATE_START, &dev->state);
1452 
1453                 /* Synchronize to scheduled poll. We cannot touch poll list, it
1454                  * can be even on different cpu. So just clear netif_running().
1455                  *
1456                  * dev->stop() will invoke napi_disable() on all of it's
1457                  * napi_struct instances on this device.
1458                  */
1459                 smp_mb__after_atomic(); /* Commit netif_running(). */
1460         }
1461 
1462         dev_deactivate_many(head);
1463 
1464         list_for_each_entry(dev, head, close_list) {
1465                 const struct net_device_ops *ops = dev->netdev_ops;
1466 
1467                 /*
1468                  *      Call the device specific close. This cannot fail.
1469                  *      Only if device is UP
1470                  *
1471                  *      We allow it to be called even after a DETACH hot-plug
1472                  *      event.
1473                  */
1474                 if (ops->ndo_stop)
1475                         ops->ndo_stop(dev);
1476 
1477                 dev->flags &= ~IFF_UP;
1478                 netpoll_poll_enable(dev);
1479         }
1480 }
1481 
1482 static void __dev_close(struct net_device *dev)
1483 {
1484         LIST_HEAD(single);
1485 
1486         list_add(&dev->close_list, &single);
1487         __dev_close_many(&single);
1488         list_del(&single);
1489 }
1490 
1491 void dev_close_many(struct list_head *head, bool unlink)
1492 {
1493         struct net_device *dev, *tmp;
1494 
1495         /* Remove the devices that don't need to be closed */
1496         list_for_each_entry_safe(dev, tmp, head, close_list)
1497                 if (!(dev->flags & IFF_UP))
1498                         list_del_init(&dev->close_list);
1499 
1500         __dev_close_many(head);
1501 
1502         list_for_each_entry_safe(dev, tmp, head, close_list) {
1503                 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1504                 call_netdevice_notifiers(NETDEV_DOWN, dev);
1505                 if (unlink)
1506                         list_del_init(&dev->close_list);
1507         }
1508 }
1509 EXPORT_SYMBOL(dev_close_many);
1510 
1511 /**
1512  *      dev_close - shutdown an interface.
1513  *      @dev: device to shutdown
1514  *
1515  *      This function moves an active device into down state. A
1516  *      %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1517  *      is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1518  *      chain.
1519  */
1520 void dev_close(struct net_device *dev)
1521 {
1522         if (dev->flags & IFF_UP) {
1523                 LIST_HEAD(single);
1524 
1525                 list_add(&dev->close_list, &single);
1526                 dev_close_many(&single, true);
1527                 list_del(&single);
1528         }
1529 }
1530 EXPORT_SYMBOL(dev_close);
1531 
1532 
1533 /**
1534  *      dev_disable_lro - disable Large Receive Offload on a device
1535  *      @dev: device
1536  *
1537  *      Disable Large Receive Offload (LRO) on a net device.  Must be
1538  *      called under RTNL.  This is needed if received packets may be
1539  *      forwarded to another interface.
1540  */
1541 void dev_disable_lro(struct net_device *dev)
1542 {
1543         struct net_device *lower_dev;
1544         struct list_head *iter;
1545 
1546         dev->wanted_features &= ~NETIF_F_LRO;
1547         netdev_update_features(dev);
1548 
1549         if (unlikely(dev->features & NETIF_F_LRO))
1550                 netdev_WARN(dev, "failed to disable LRO!\n");
1551 
1552         netdev_for_each_lower_dev(dev, lower_dev, iter)
1553                 dev_disable_lro(lower_dev);
1554 }
1555 EXPORT_SYMBOL(dev_disable_lro);
1556 
1557 /**
1558  *      dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1559  *      @dev: device
1560  *
1561  *      Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1562  *      called under RTNL.  This is needed if Generic XDP is installed on
1563  *      the device.
1564  */
1565 static void dev_disable_gro_hw(struct net_device *dev)
1566 {
1567         dev->wanted_features &= ~NETIF_F_GRO_HW;
1568         netdev_update_features(dev);
1569 
1570         if (unlikely(dev->features & NETIF_F_GRO_HW))
1571                 netdev_WARN(dev, "failed to disable GRO_HW!\n");
1572 }
1573 
1574 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1575 {
1576 #define N(val)                                          \
1577         case NETDEV_##val:                              \
1578                 return "NETDEV_" __stringify(val);
1579         switch (cmd) {
1580         N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1581         N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1582         N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1583         N(POST_INIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN) N(CHANGEUPPER)
1584         N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
1585         N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
1586         N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1587         N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1588         N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1589         };
1590 #undef N
1591         return "UNKNOWN_NETDEV_EVENT";
1592 }
1593 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1594 
1595 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1596                                    struct net_device *dev)
1597 {
1598         struct netdev_notifier_info info = {
1599                 .dev = dev,
1600         };
1601 
1602         return nb->notifier_call(nb, val, &info);
1603 }
1604 
1605 static int dev_boot_phase = 1;
1606 
1607 /**
1608  * register_netdevice_notifier - register a network notifier block
1609  * @nb: notifier
1610  *
1611  * Register a notifier to be called when network device events occur.
1612  * The notifier passed is linked into the kernel structures and must
1613  * not be reused until it has been unregistered. A negative errno code
1614  * is returned on a failure.
1615  *
1616  * When registered all registration and up events are replayed
1617  * to the new notifier to allow device to have a race free
1618  * view of the network device list.
1619  */
1620 
1621 int register_netdevice_notifier(struct notifier_block *nb)
1622 {
1623         struct net_device *dev;
1624         struct net_device *last;
1625         struct net *net;
1626         int err;
1627 
1628         /* Close race with setup_net() and cleanup_net() */
1629         down_write(&pernet_ops_rwsem);
1630         rtnl_lock();
1631         err = raw_notifier_chain_register(&netdev_chain, nb);
1632         if (err)
1633                 goto unlock;
1634         if (dev_boot_phase)
1635                 goto unlock;
1636         for_each_net(net) {
1637                 for_each_netdev(net, dev) {
1638                         err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1639                         err = notifier_to_errno(err);
1640                         if (err)
1641                                 goto rollback;
1642 
1643                         if (!(dev->flags & IFF_UP))
1644                                 continue;
1645 
1646                         call_netdevice_notifier(nb, NETDEV_UP, dev);
1647                 }
1648         }
1649 
1650 unlock:
1651         rtnl_unlock();
1652         up_write(&pernet_ops_rwsem);
1653         return err;
1654 
1655 rollback:
1656         last = dev;
1657         for_each_net(net) {
1658                 for_each_netdev(net, dev) {
1659                         if (dev == last)
1660                                 goto outroll;
1661 
1662                         if (dev->flags & IFF_UP) {
1663                                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1664                                                         dev);
1665                                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1666                         }
1667                         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1668                 }
1669         }
1670 
1671 outroll:
1672         raw_notifier_chain_unregister(&netdev_chain, nb);
1673         goto unlock;
1674 }
1675 EXPORT_SYMBOL(register_netdevice_notifier);
1676 
1677 /**
1678  * unregister_netdevice_notifier - unregister a network notifier block
1679  * @nb: notifier
1680  *
1681  * Unregister a notifier previously registered by
1682  * register_netdevice_notifier(). The notifier is unlinked into the
1683  * kernel structures and may then be reused. A negative errno code
1684  * is returned on a failure.
1685  *
1686  * After unregistering unregister and down device events are synthesized
1687  * for all devices on the device list to the removed notifier to remove
1688  * the need for special case cleanup code.
1689  */
1690 
1691 int unregister_netdevice_notifier(struct notifier_block *nb)
1692 {
1693         struct net_device *dev;
1694         struct net *net;
1695         int err;
1696 
1697         /* Close race with setup_net() and cleanup_net() */
1698         down_write(&pernet_ops_rwsem);
1699         rtnl_lock();
1700         err = raw_notifier_chain_unregister(&netdev_chain, nb);
1701         if (err)
1702                 goto unlock;
1703 
1704         for_each_net(net) {
1705                 for_each_netdev(net, dev) {
1706                         if (dev->flags & IFF_UP) {
1707                                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1708                                                         dev);
1709                                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1710                         }
1711                         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1712                 }
1713         }
1714 unlock:
1715         rtnl_unlock();
1716         up_write(&pernet_ops_rwsem);
1717         return err;
1718 }
1719 EXPORT_SYMBOL(unregister_netdevice_notifier);
1720 
1721 /**
1722  *      call_netdevice_notifiers_info - call all network notifier blocks
1723  *      @val: value passed unmodified to notifier function
1724  *      @info: notifier information data
1725  *
1726  *      Call all network notifier blocks.  Parameters and return value
1727  *      are as for raw_notifier_call_chain().
1728  */
1729 
1730 static int call_netdevice_notifiers_info(unsigned long val,
1731                                          struct netdev_notifier_info *info)
1732 {
1733         ASSERT_RTNL();
1734         return raw_notifier_call_chain(&netdev_chain, val, info);
1735 }
1736 
1737 /**
1738  *      call_netdevice_notifiers - call all network notifier blocks
1739  *      @val: value passed unmodified to notifier function
1740  *      @dev: net_device pointer passed unmodified to notifier function
1741  *
1742  *      Call all network notifier blocks.  Parameters and return value
1743  *      are as for raw_notifier_call_chain().
1744  */
1745 
1746 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1747 {
1748         struct netdev_notifier_info info = {
1749                 .dev = dev,
1750         };
1751 
1752         return call_netdevice_notifiers_info(val, &info);
1753 }
1754 EXPORT_SYMBOL(call_netdevice_notifiers);
1755 
1756 #ifdef CONFIG_NET_INGRESS
1757 static struct static_key ingress_needed __read_mostly;
1758 
1759 void net_inc_ingress_queue(void)
1760 {
1761         static_key_slow_inc(&ingress_needed);
1762 }
1763 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
1764 
1765 void net_dec_ingress_queue(void)
1766 {
1767         static_key_slow_dec(&ingress_needed);
1768 }
1769 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
1770 #endif
1771 
1772 #ifdef CONFIG_NET_EGRESS
1773 static struct static_key egress_needed __read_mostly;
1774 
1775 void net_inc_egress_queue(void)
1776 {
1777         static_key_slow_inc(&egress_needed);
1778 }
1779 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
1780 
1781 void net_dec_egress_queue(void)
1782 {
1783         static_key_slow_dec(&egress_needed);
1784 }
1785 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
1786 #endif
1787 
1788 static struct static_key netstamp_needed __read_mostly;
1789 #ifdef HAVE_JUMP_LABEL
1790 static atomic_t netstamp_needed_deferred;
1791 static atomic_t netstamp_wanted;
1792 static void netstamp_clear(struct work_struct *work)
1793 {
1794         int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
1795         int wanted;
1796 
1797         wanted = atomic_add_return(deferred, &netstamp_wanted);
1798         if (wanted > 0)
1799                 static_key_enable(&netstamp_needed);
1800         else
1801                 static_key_disable(&netstamp_needed);
1802 }
1803 static DECLARE_WORK(netstamp_work, netstamp_clear);
1804 #endif
1805 
1806 void net_enable_timestamp(void)
1807 {
1808 #ifdef HAVE_JUMP_LABEL
1809         int wanted;
1810 
1811         while (1) {
1812                 wanted = atomic_read(&netstamp_wanted);
1813                 if (wanted <= 0)
1814                         break;
1815                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
1816                         return;
1817         }
1818         atomic_inc(&netstamp_needed_deferred);
1819         schedule_work(&netstamp_work);
1820 #else
1821         static_key_slow_inc(&netstamp_needed);
1822 #endif
1823 }
1824 EXPORT_SYMBOL(net_enable_timestamp);
1825 
1826 void net_disable_timestamp(void)
1827 {
1828 #ifdef HAVE_JUMP_LABEL
1829         int wanted;
1830 
1831         while (1) {
1832                 wanted = atomic_read(&netstamp_wanted);
1833                 if (wanted <= 1)
1834                         break;
1835                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
1836                         return;
1837         }
1838         atomic_dec(&netstamp_needed_deferred);
1839         schedule_work(&netstamp_work);
1840 #else
1841         static_key_slow_dec(&netstamp_needed);
1842 #endif
1843 }
1844 EXPORT_SYMBOL(net_disable_timestamp);
1845 
1846 static inline void net_timestamp_set(struct sk_buff *skb)
1847 {
1848         skb->tstamp = 0;
1849         if (static_key_false(&netstamp_needed))
1850                 __net_timestamp(skb);
1851 }
1852 
1853 #define net_timestamp_check(COND, SKB)                  \
1854         if (static_key_false(&netstamp_needed)) {               \
1855                 if ((COND) && !(SKB)->tstamp)   \
1856                         __net_timestamp(SKB);           \
1857         }                                               \
1858 
1859 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
1860 {
1861         unsigned int len;
1862 
1863         if (!(dev->flags & IFF_UP))
1864                 return false;
1865 
1866         len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1867         if (skb->len <= len)
1868                 return true;
1869 
1870         /* if TSO is enabled, we don't care about the length as the packet
1871          * could be forwarded without being segmented before
1872          */
1873         if (skb_is_gso(skb))
1874                 return true;
1875 
1876         return false;
1877 }
1878 EXPORT_SYMBOL_GPL(is_skb_forwardable);
1879 
1880 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1881 {
1882         int ret = ____dev_forward_skb(dev, skb);
1883 
1884         if (likely(!ret)) {
1885                 skb->protocol = eth_type_trans(skb, dev);
1886                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
1887         }
1888 
1889         return ret;
1890 }
1891 EXPORT_SYMBOL_GPL(__dev_forward_skb);
1892 
1893 /**
1894  * dev_forward_skb - loopback an skb to another netif
1895  *
1896  * @dev: destination network device
1897  * @skb: buffer to forward
1898  *
1899  * return values:
1900  *      NET_RX_SUCCESS  (no congestion)
1901  *      NET_RX_DROP     (packet was dropped, but freed)
1902  *
1903  * dev_forward_skb can be used for injecting an skb from the
1904  * start_xmit function of one device into the receive queue
1905  * of another device.
1906  *
1907  * The receiving device may be in another namespace, so
1908  * we have to clear all information in the skb that could
1909  * impact namespace isolation.
1910  */
1911 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1912 {
1913         return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
1914 }
1915 EXPORT_SYMBOL_GPL(dev_forward_skb);
1916 
1917 static inline int deliver_skb(struct sk_buff *skb,
1918                               struct packet_type *pt_prev,
1919                               struct net_device *orig_dev)
1920 {
1921         if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
1922                 return -ENOMEM;
1923         refcount_inc(&skb->users);
1924         return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1925 }
1926 
1927 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
1928                                           struct packet_type **pt,
1929                                           struct net_device *orig_dev,
1930                                           __be16 type,
1931                                           struct list_head *ptype_list)
1932 {
1933         struct packet_type *ptype, *pt_prev = *pt;
1934 
1935         list_for_each_entry_rcu(ptype, ptype_list, list) {
1936                 if (ptype->type != type)
1937                         continue;
1938                 if (pt_prev)
1939                         deliver_skb(skb, pt_prev, orig_dev);
1940                 pt_prev = ptype;
1941         }
1942         *pt = pt_prev;
1943 }
1944 
1945 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
1946 {
1947         if (!ptype->af_packet_priv || !skb->sk)
1948                 return false;
1949 
1950         if (ptype->id_match)
1951                 return ptype->id_match(ptype, skb->sk);
1952         else if ((struct sock *)ptype->af_packet_priv == skb->sk)
1953                 return true;
1954 
1955         return false;
1956 }
1957 
1958 /*
1959  *      Support routine. Sends outgoing frames to any network
1960  *      taps currently in use.
1961  */
1962 
1963 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1964 {
1965         struct packet_type *ptype;
1966         struct sk_buff *skb2 = NULL;
1967         struct packet_type *pt_prev = NULL;
1968         struct list_head *ptype_list = &ptype_all;
1969 
1970         rcu_read_lock();
1971 again:
1972         list_for_each_entry_rcu(ptype, ptype_list, list) {
1973                 /* Never send packets back to the socket
1974                  * they originated from - MvS (miquels@drinkel.ow.org)
1975                  */
1976                 if (skb_loop_sk(ptype, skb))
1977                         continue;
1978 
1979                 if (pt_prev) {
1980                         deliver_skb(skb2, pt_prev, skb->dev);
1981                         pt_prev = ptype;
1982                         continue;
1983                 }
1984 
1985                 /* need to clone skb, done only once */
1986                 skb2 = skb_clone(skb, GFP_ATOMIC);
1987                 if (!skb2)
1988                         goto out_unlock;
1989 
1990                 net_timestamp_set(skb2);
1991 
1992                 /* skb->nh should be correctly
1993                  * set by sender, so that the second statement is
1994                  * just protection against buggy protocols.
1995                  */
1996                 skb_reset_mac_header(skb2);
1997 
1998                 if (skb_network_header(skb2) < skb2->data ||
1999                     skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2000                         net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2001                                              ntohs(skb2->protocol),
2002                                              dev->name);
2003                         skb_reset_network_header(skb2);
2004                 }
2005 
2006                 skb2->transport_header = skb2->network_header;
2007                 skb2->pkt_type = PACKET_OUTGOING;
2008                 pt_prev = ptype;
2009         }
2010 
2011         if (ptype_list == &ptype_all) {
2012                 ptype_list = &dev->ptype_all;
2013                 goto again;
2014         }
2015 out_unlock:
2016         if (pt_prev) {
2017                 if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2018                         pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2019                 else
2020                         kfree_skb(skb2);
2021         }
2022         rcu_read_unlock();
2023 }
2024 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2025 
2026 /**
2027  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2028  * @dev: Network device
2029  * @txq: number of queues available
2030  *
2031  * If real_num_tx_queues is changed the tc mappings may no longer be
2032  * valid. To resolve this verify the tc mapping remains valid and if
2033  * not NULL the mapping. With no priorities mapping to this
2034  * offset/count pair it will no longer be used. In the worst case TC0
2035  * is invalid nothing can be done so disable priority mappings. If is
2036  * expected that drivers will fix this mapping if they can before
2037  * calling netif_set_real_num_tx_queues.
2038  */
2039 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2040 {
2041         int i;
2042         struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2043 
2044         /* If TC0 is invalidated disable TC mapping */
2045         if (tc->offset + tc->count > txq) {
2046                 pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2047                 dev->num_tc = 0;
2048                 return;
2049         }
2050 
2051         /* Invalidated prio to tc mappings set to TC0 */
2052         for (i = 1; i < TC_BITMASK + 1; i++) {
2053                 int q = netdev_get_prio_tc_map(dev, i);
2054 
2055                 tc = &dev->tc_to_txq[q];
2056                 if (tc->offset + tc->count > txq) {
2057                         pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2058                                 i, q);
2059                         netdev_set_prio_tc_map(dev, i, 0);
2060                 }
2061         }
2062 }
2063 
2064 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2065 {
2066         if (dev->num_tc) {
2067                 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2068                 int i;
2069 
2070                 for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2071                         if ((txq - tc->offset) < tc->count)
2072                                 return i;
2073                 }
2074 
2075                 return -1;
2076         }
2077 
2078         return 0;
2079 }
2080 EXPORT_SYMBOL(netdev_txq_to_tc);
2081 
2082 #ifdef CONFIG_XPS
2083 static DEFINE_MUTEX(xps_map_mutex);
2084 #define xmap_dereference(P)             \
2085         rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2086 
2087 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2088                              int tci, u16 index)
2089 {
2090         struct xps_map *map = NULL;
2091         int pos;
2092 
2093         if (dev_maps)
2094                 map = xmap_dereference(dev_maps->cpu_map[tci]);
2095         if (!map)
2096                 return false;
2097 
2098         for (pos = map->len; pos--;) {
2099                 if (map->queues[pos] != index)
2100                         continue;
2101 
2102                 if (map->len > 1) {
2103                         map->queues[pos] = map->queues[--map->len];
2104                         break;
2105                 }
2106 
2107                 RCU_INIT_POINTER(dev_maps->cpu_map[tci], NULL);
2108                 kfree_rcu(map, rcu);
2109                 return false;
2110         }
2111 
2112         return true;
2113 }
2114 
2115 static bool remove_xps_queue_cpu(struct net_device *dev,
2116                                  struct xps_dev_maps *dev_maps,
2117                                  int cpu, u16 offset, u16 count)
2118 {
2119         int num_tc = dev->num_tc ? : 1;
2120         bool active = false;
2121         int tci;
2122 
2123         for (tci = cpu * num_tc; num_tc--; tci++) {
2124                 int i, j;
2125 
2126                 for (i = count, j = offset; i--; j++) {
2127                         if (!remove_xps_queue(dev_maps, cpu, j))
2128                                 break;
2129                 }
2130 
2131                 active |= i < 0;
2132         }
2133 
2134         return active;
2135 }
2136 
2137 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2138                                    u16 count)
2139 {
2140         struct xps_dev_maps *dev_maps;
2141         int cpu, i;
2142         bool active = false;
2143 
2144         mutex_lock(&xps_map_mutex);
2145         dev_maps = xmap_dereference(dev->xps_maps);
2146 
2147         if (!dev_maps)
2148                 goto out_no_maps;
2149 
2150         for_each_possible_cpu(cpu)
2151                 active |= remove_xps_queue_cpu(dev, dev_maps, cpu,
2152                                                offset, count);
2153 
2154         if (!active) {
2155                 RCU_INIT_POINTER(dev->xps_maps, NULL);
2156                 kfree_rcu(dev_maps, rcu);
2157         }
2158 
2159         for (i = offset + (count - 1); count--; i--)
2160                 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
2161                                              NUMA_NO_NODE);
2162 
2163 out_no_maps:
2164         mutex_unlock(&xps_map_mutex);
2165 }
2166 
2167 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2168 {
2169         netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2170 }
2171 
2172 static struct xps_map *expand_xps_map(struct xps_map *map,
2173                                       int cpu, u16 index)
2174 {
2175         struct xps_map *new_map;
2176         int alloc_len = XPS_MIN_MAP_ALLOC;
2177         int i, pos;
2178 
2179         for (pos = 0; map && pos < map->len; pos++) {
2180                 if (map->queues[pos] != index)
2181                         continue;
2182                 return map;
2183         }
2184 
2185         /* Need to add queue to this CPU's existing map */
2186         if (map) {
2187                 if (pos < map->alloc_len)
2188                         return map;
2189 
2190                 alloc_len = map->alloc_len * 2;
2191         }
2192 
2193         /* Need to allocate new map to store queue on this CPU's map */
2194         new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2195                                cpu_to_node(cpu));
2196         if (!new_map)
2197                 return NULL;
2198 
2199         for (i = 0; i < pos; i++)
2200                 new_map->queues[i] = map->queues[i];
2201         new_map->alloc_len = alloc_len;
2202         new_map->len = pos;
2203 
2204         return new_map;
2205 }
2206 
2207 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2208                         u16 index)
2209 {
2210         struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
2211         int i, cpu, tci, numa_node_id = -2;
2212         int maps_sz, num_tc = 1, tc = 0;
2213         struct xps_map *map, *new_map;
2214         bool active = false;
2215 
2216         if (dev->num_tc) {
2217                 num_tc = dev->num_tc;
2218                 tc = netdev_txq_to_tc(dev, index);
2219                 if (tc < 0)
2220                         return -EINVAL;
2221         }
2222 
2223         maps_sz = XPS_DEV_MAPS_SIZE(num_tc);
2224         if (maps_sz < L1_CACHE_BYTES)
2225                 maps_sz = L1_CACHE_BYTES;
2226 
2227         mutex_lock(&xps_map_mutex);
2228 
2229         dev_maps = xmap_dereference(dev->xps_maps);
2230 
2231         /* allocate memory for queue storage */
2232         for_each_cpu_and(cpu, cpu_online_mask, mask) {
2233                 if (!new_dev_maps)
2234                         new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2235                 if (!new_dev_maps) {
2236                         mutex_unlock(&xps_map_mutex);
2237                         return -ENOMEM;
2238                 }
2239 
2240                 tci = cpu * num_tc + tc;
2241                 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[tci]) :
2242                                  NULL;
2243 
2244                 map = expand_xps_map(map, cpu, index);
2245                 if (!map)
2246                         goto error;
2247 
2248                 RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
2249         }
2250 
2251         if (!new_dev_maps)
2252                 goto out_no_new_maps;
2253 
2254         for_each_possible_cpu(cpu) {
2255                 /* copy maps belonging to foreign traffic classes */
2256                 for (i = tc, tci = cpu * num_tc; dev_maps && i--; tci++) {
2257                         /* fill in the new device map from the old device map */
2258                         map = xmap_dereference(dev_maps->cpu_map[tci]);
2259                         RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
2260                 }
2261 
2262                 /* We need to explicitly update tci as prevous loop
2263                  * could break out early if dev_maps is NULL.
2264                  */
2265                 tci = cpu * num_tc + tc;
2266 
2267                 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
2268                         /* add queue to CPU maps */
2269                         int pos = 0;
2270 
2271                         map = xmap_dereference(new_dev_maps->cpu_map[tci]);
2272                         while ((pos < map->len) && (map->queues[pos] != index))
2273                                 pos++;
2274 
2275                         if (pos == map->len)
2276                                 map->queues[map->len++] = index;
2277 #ifdef CONFIG_NUMA
2278                         if (numa_node_id == -2)
2279                                 numa_node_id = cpu_to_node(cpu);
2280                         else if (numa_node_id != cpu_to_node(cpu))
2281                                 numa_node_id = -1;
2282 #endif
2283                 } else if (dev_maps) {
2284                         /* fill in the new device map from the old device map */
2285                         map = xmap_dereference(dev_maps->cpu_map[tci]);
2286                         RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
2287                 }
2288 
2289                 /* copy maps belonging to foreign traffic classes */
2290                 for (i = num_tc - tc, tci++; dev_maps && --i; tci++) {
2291                         /* fill in the new device map from the old device map */
2292                         map = xmap_dereference(dev_maps->cpu_map[tci]);
2293                         RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
2294                 }
2295         }
2296 
2297         rcu_assign_pointer(dev->xps_maps, new_dev_maps);
2298 
2299         /* Cleanup old maps */
2300         if (!dev_maps)
2301                 goto out_no_old_maps;
2302 
2303         for_each_possible_cpu(cpu) {
2304                 for (i = num_tc, tci = cpu * num_tc; i--; tci++) {
2305                         new_map = xmap_dereference(new_dev_maps->cpu_map[tci]);
2306                         map = xmap_dereference(dev_maps->cpu_map[tci]);
2307                         if (map && map != new_map)
2308                                 kfree_rcu(map, rcu);
2309                 }
2310         }
2311 
2312         kfree_rcu(dev_maps, rcu);
2313 
2314 out_no_old_maps:
2315         dev_maps = new_dev_maps;
2316         active = true;
2317 
2318 out_no_new_maps:
2319         /* update Tx queue numa node */
2320         netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2321                                      (numa_node_id >= 0) ? numa_node_id :
2322                                      NUMA_NO_NODE);
2323 
2324         if (!dev_maps)
2325                 goto out_no_maps;
2326 
2327         /* removes queue from unused CPUs */
2328         for_each_possible_cpu(cpu) {
2329                 for (i = tc, tci = cpu * num_tc; i--; tci++)
2330                         active |= remove_xps_queue(dev_maps, tci, index);
2331                 if (!cpumask_test_cpu(cpu, mask) || !cpu_online(cpu))
2332                         active |= remove_xps_queue(dev_maps, tci, index);
2333                 for (i = num_tc - tc, tci++; --i; tci++)
2334                         active |= remove_xps_queue(dev_maps, tci, index);
2335         }
2336 
2337         /* free map if not active */
2338         if (!active) {
2339                 RCU_INIT_POINTER(dev->xps_maps, NULL);
2340                 kfree_rcu(dev_maps, rcu);
2341         }
2342 
2343 out_no_maps:
2344         mutex_unlock(&xps_map_mutex);
2345 
2346         return 0;
2347 error:
2348         /* remove any maps that we added */
2349         for_each_possible_cpu(cpu) {
2350                 for (i = num_tc, tci = cpu * num_tc; i--; tci++) {
2351                         new_map = xmap_dereference(new_dev_maps->cpu_map[tci]);
2352                         map = dev_maps ?
2353                               xmap_dereference(dev_maps->cpu_map[tci]) :
2354                               NULL;
2355                         if (new_map && new_map != map)
2356                                 kfree(new_map);
2357                 }
2358         }
2359 
2360         mutex_unlock(&xps_map_mutex);
2361 
2362         kfree(new_dev_maps);
2363         return -ENOMEM;
2364 }
2365 EXPORT_SYMBOL(netif_set_xps_queue);
2366 
2367 #endif
2368 void netdev_reset_tc(struct net_device *dev)
2369 {
2370 #ifdef CONFIG_XPS
2371         netif_reset_xps_queues_gt(dev, 0);
2372 #endif
2373         dev->num_tc = 0;
2374         memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2375         memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2376 }
2377 EXPORT_SYMBOL(netdev_reset_tc);
2378 
2379 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2380 {
2381         if (tc >= dev->num_tc)
2382                 return -EINVAL;
2383 
2384 #ifdef CONFIG_XPS
2385         netif_reset_xps_queues(dev, offset, count);
2386 #endif
2387         dev->tc_to_txq[tc].count = count;
2388         dev->tc_to_txq[tc].offset = offset;
2389         return 0;
2390 }
2391 EXPORT_SYMBOL(netdev_set_tc_queue);
2392 
2393 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2394 {
2395         if (num_tc > TC_MAX_QUEUE)
2396                 return -EINVAL;
2397 
2398 #ifdef CONFIG_XPS
2399         netif_reset_xps_queues_gt(dev, 0);
2400 #endif
2401         dev->num_tc = num_tc;
2402         return 0;
2403 }
2404 EXPORT_SYMBOL(netdev_set_num_tc);
2405 
2406 /*
2407  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2408  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2409  */
2410 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2411 {
2412         bool disabling;
2413         int rc;
2414 
2415         disabling = txq < dev->real_num_tx_queues;
2416 
2417         if (txq < 1 || txq > dev->num_tx_queues)
2418                 return -EINVAL;
2419 
2420         if (dev->reg_state == NETREG_REGISTERED ||
2421             dev->reg_state == NETREG_UNREGISTERING) {
2422                 ASSERT_RTNL();
2423 
2424                 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2425                                                   txq);
2426                 if (rc)
2427                         return rc;
2428 
2429                 if (dev->num_tc)
2430                         netif_setup_tc(dev, txq);
2431 
2432                 dev->real_num_tx_queues = txq;
2433 
2434                 if (disabling) {
2435                         synchronize_net();
2436                         qdisc_reset_all_tx_gt(dev, txq);
2437 #ifdef CONFIG_XPS
2438                         netif_reset_xps_queues_gt(dev, txq);
2439 #endif
2440                 }
2441         } else {
2442                 dev->real_num_tx_queues = txq;
2443         }
2444 
2445         return 0;
2446 }
2447 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2448 
2449 #ifdef CONFIG_SYSFS
2450 /**
2451  *      netif_set_real_num_rx_queues - set actual number of RX queues used
2452  *      @dev: Network device
2453  *      @rxq: Actual number of RX queues
2454  *
2455  *      This must be called either with the rtnl_lock held or before
2456  *      registration of the net device.  Returns 0 on success, or a
2457  *      negative error code.  If called before registration, it always
2458  *      succeeds.
2459  */
2460 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2461 {
2462         int rc;
2463 
2464         if (rxq < 1 || rxq > dev->num_rx_queues)
2465                 return -EINVAL;
2466 
2467         if (dev->reg_state == NETREG_REGISTERED) {
2468                 ASSERT_RTNL();
2469 
2470                 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2471                                                   rxq);
2472                 if (rc)
2473                         return rc;
2474         }
2475 
2476         dev->real_num_rx_queues = rxq;
2477         return 0;
2478 }
2479 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2480 #endif
2481 
2482 /**
2483  * netif_get_num_default_rss_queues - default number of RSS queues
2484  *
2485  * This routine should set an upper limit on the number of RSS queues
2486  * used by default by multiqueue devices.
2487  */
2488 int netif_get_num_default_rss_queues(void)
2489 {
2490         return is_kdump_kernel() ?
2491                 1 : min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
2492 }
2493 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
2494 
2495 static void __netif_reschedule(struct Qdisc *q)
2496 {
2497         struct softnet_data *sd;
2498         unsigned long flags;
2499 
2500         local_irq_save(flags);
2501         sd = this_cpu_ptr(&softnet_data);
2502         q->next_sched = NULL;
2503         *sd->output_queue_tailp = q;
2504         sd->output_queue_tailp = &q->next_sched;
2505         raise_softirq_irqoff(NET_TX_SOFTIRQ);
2506         local_irq_restore(flags);
2507 }
2508 
2509 void __netif_schedule(struct Qdisc *q)
2510 {
2511         if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
2512                 __netif_reschedule(q);
2513 }
2514 EXPORT_SYMBOL(__netif_schedule);
2515 
2516 struct dev_kfree_skb_cb {
2517         enum skb_free_reason reason;
2518 };
2519 
2520 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
2521 {
2522         return (struct dev_kfree_skb_cb *)skb->cb;
2523 }
2524 
2525 void netif_schedule_queue(struct netdev_queue *txq)
2526 {
2527         rcu_read_lock();
2528         if (!(txq->state & QUEUE_STATE_ANY_XOFF)) {
2529                 struct Qdisc *q = rcu_dereference(txq->qdisc);
2530 
2531                 __netif_schedule(q);
2532         }
2533         rcu_read_unlock();
2534 }
2535 EXPORT_SYMBOL(netif_schedule_queue);
2536 
2537 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
2538 {
2539         if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
2540                 struct Qdisc *q;
2541 
2542                 rcu_read_lock();
2543                 q = rcu_dereference(dev_queue->qdisc);
2544                 __netif_schedule(q);
2545                 rcu_read_unlock();
2546         }
2547 }
2548 EXPORT_SYMBOL(netif_tx_wake_queue);
2549 
2550 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
2551 {
2552         unsigned long flags;
2553 
2554         if (unlikely(!skb))
2555                 return;
2556 
2557         if (likely(refcount_read(&skb->users) == 1)) {
2558                 smp_rmb();
2559                 refcount_set(&skb->users, 0);
2560         } else if (likely(!refcount_dec_and_test(&skb->users))) {
2561                 return;
2562         }
2563         get_kfree_skb_cb(skb)->reason = reason;
2564         local_irq_save(flags);
2565         skb->next = __this_cpu_read(softnet_data.completion_queue);
2566         __this_cpu_write(softnet_data.completion_queue, skb);
2567         raise_softirq_irqoff(NET_TX_SOFTIRQ);
2568         local_irq_restore(flags);
2569 }
2570 EXPORT_SYMBOL(__dev_kfree_skb_irq);
2571 
2572 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
2573 {
2574         if (in_irq() || irqs_disabled())
2575                 __dev_kfree_skb_irq(skb, reason);
2576         else
2577                 dev_kfree_skb(skb);
2578 }
2579 EXPORT_SYMBOL(__dev_kfree_skb_any);
2580 
2581 
2582 /**
2583  * netif_device_detach - mark device as removed
2584  * @dev: network device
2585  *
2586  * Mark device as removed from system and therefore no longer available.
2587  */
2588 void netif_device_detach(struct net_device *dev)
2589 {
2590         if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
2591             netif_running(dev)) {
2592                 netif_tx_stop_all_queues(dev);
2593         }
2594 }
2595 EXPORT_SYMBOL(netif_device_detach);
2596 
2597 /**
2598  * netif_device_attach - mark device as attached
2599  * @dev: network device
2600  *
2601  * Mark device as attached from system and restart if needed.
2602  */
2603 void netif_device_attach(struct net_device *dev)
2604 {
2605         if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
2606             netif_running(dev)) {
2607                 netif_tx_wake_all_queues(dev);
2608                 __netdev_watchdog_up(dev);
2609         }
2610 }
2611 EXPORT_SYMBOL(netif_device_attach);
2612 
2613 /*
2614  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
2615  * to be used as a distribution range.
2616  */
2617 u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
2618                   unsigned int num_tx_queues)
2619 {
2620         u32 hash;
2621         u16 qoffset = 0;
2622         u16 qcount = num_tx_queues;
2623 
2624         if (skb_rx_queue_recorded(skb)) {
2625                 hash = skb_get_rx_queue(skb);
2626                 while (unlikely(hash >= num_tx_queues))
2627                         hash -= num_tx_queues;
2628                 return hash;
2629         }
2630 
2631         if (dev->num_tc) {
2632                 u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
2633 
2634                 qoffset = dev->tc_to_txq[tc].offset;
2635                 qcount = dev->tc_to_txq[tc].count;
2636         }
2637 
2638         return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
2639 }
2640 EXPORT_SYMBOL(__skb_tx_hash);
2641 
2642 static void skb_warn_bad_offload(const struct sk_buff *skb)
2643 {
2644         static const netdev_features_t null_features;
2645         struct net_device *dev = skb->dev;
2646         const char *name = "";
2647 
2648         if (!net_ratelimit())
2649                 return;
2650 
2651         if (dev) {
2652                 if (dev->dev.parent)
2653                         name = dev_driver_string(dev->dev.parent);
2654                 else
2655                         name = netdev_name(dev);
2656         }
2657         WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
2658              "gso_type=%d ip_summed=%d\n",
2659              name, dev ? &dev->features : &null_features,
2660              skb->sk ? &skb->sk->sk_route_caps : &null_features,
2661              skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
2662              skb_shinfo(skb)->gso_type, skb->ip_summed);
2663 }
2664 
2665 /*
2666  * Invalidate hardware checksum when packet is to be mangled, and
2667  * complete checksum manually on outgoing path.
2668  */
2669 int skb_checksum_help(struct sk_buff *skb)
2670 {
2671         __wsum csum;
2672         int ret = 0, offset;
2673 
2674         if (skb->ip_summed == CHECKSUM_COMPLETE)
2675                 goto out_set_summed;
2676 
2677         if (unlikely(skb_shinfo(skb)->gso_size)) {
2678                 skb_warn_bad_offload(skb);
2679                 return -EINVAL;
2680         }
2681 
2682         /* Before computing a checksum, we should make sure no frag could
2683          * be modified by an external entity : checksum could be wrong.
2684          */
2685         if (skb_has_shared_frag(skb)) {
2686                 ret = __skb_linearize(skb);
2687                 if (ret)
2688                         goto out;
2689         }
2690 
2691         offset = skb_checksum_start_offset(skb);
2692         BUG_ON(offset >= skb_headlen(skb));
2693         csum = skb_checksum(skb, offset, skb->len - offset, 0);
2694 
2695         offset += skb->csum_offset;
2696         BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
2697 
2698         if (skb_cloned(skb) &&
2699             !skb_clone_writable(skb, offset + sizeof(__sum16))) {
2700                 ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
2701                 if (ret)
2702                         goto out;
2703         }
2704 
2705         *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
2706 out_set_summed:
2707         skb->ip_summed = CHECKSUM_NONE;
2708 out:
2709         return ret;
2710 }
2711 EXPORT_SYMBOL(skb_checksum_help);
2712 
2713 int skb_crc32c_csum_help(struct sk_buff *skb)
2714 {
2715         __le32 crc32c_csum;
2716         int ret = 0, offset, start;
2717 
2718         if (skb->ip_summed != CHECKSUM_PARTIAL)
2719                 goto out;
2720 
2721         if (unlikely(skb_is_gso(skb)))
2722                 goto out;
2723 
2724         /* Before computing a checksum, we should make sure no frag could
2725          * be modified by an external entity : checksum could be wrong.
2726          */
2727         if (unlikely(skb_has_shared_frag(skb))) {
2728                 ret = __skb_linearize(skb);
2729                 if (ret)
2730                         goto out;
2731         }
2732         start = skb_checksum_start_offset(skb);
2733         offset = start + offsetof(struct sctphdr, checksum);
2734         if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
2735                 ret = -EINVAL;
2736                 goto out;
2737         }
2738         if (skb_cloned(skb) &&
2739             !skb_clone_writable(skb, offset + sizeof(__le32))) {
2740                 ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
2741                 if (ret)
2742                         goto out;
2743         }
2744         crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
2745                                                   skb->len - start, ~(__u32)0,
2746                                                   crc32c_csum_stub));
2747         *(__le32 *)(skb->data + offset) = crc32c_csum;
2748         skb->ip_summed = CHECKSUM_NONE;
2749         skb->csum_not_inet = 0;
2750 out:
2751         return ret;
2752 }
2753 
2754 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
2755 {
2756         __be16 type = skb->protocol;
2757 
2758         /* Tunnel gso handlers can set protocol to ethernet. */
2759         if (type == htons(ETH_P_TEB)) {
2760                 struct ethhdr *eth;
2761 
2762                 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
2763                         return 0;
2764 
2765                 eth = (struct ethhdr *)skb->data;
2766                 type = eth->h_proto;
2767         }
2768 
2769         return __vlan_get_protocol(skb, type, depth);
2770 }
2771 
2772 /**
2773  *      skb_mac_gso_segment - mac layer segmentation handler.
2774  *      @skb: buffer to segment
2775  *      @features: features for the output path (see dev->features)
2776  */
2777 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
2778                                     netdev_features_t features)
2779 {
2780         struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
2781         struct packet_offload *ptype;
2782         int vlan_depth = skb->mac_len;
2783         __be16 type = skb_network_protocol(skb, &vlan_depth);
2784 
2785         if (unlikely(!type))
2786                 return ERR_PTR(-EINVAL);
2787 
2788         __skb_pull(skb, vlan_depth);
2789 
2790         rcu_read_lock();
2791         list_for_each_entry_rcu(ptype, &offload_base, list) {
2792                 if (ptype->type == type && ptype->callbacks.gso_segment) {
2793                         segs = ptype->callbacks.gso_segment(skb, features);
2794                         break;
2795                 }
2796         }
2797         rcu_read_unlock();
2798 
2799         __skb_push(skb, skb->data - skb_mac_header(skb));
2800 
2801         return segs;
2802 }
2803 EXPORT_SYMBOL(skb_mac_gso_segment);
2804 
2805 
2806 /* openvswitch calls this on rx path, so we need a different check.
2807  */
2808 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
2809 {
2810         if (tx_path)
2811                 return skb->ip_summed != CHECKSUM_PARTIAL &&
2812                        skb->ip_summed != CHECKSUM_UNNECESSARY;
2813 
2814         return skb->ip_summed == CHECKSUM_NONE;
2815 }
2816 
2817 /**
2818  *      __skb_gso_segment - Perform segmentation on skb.
2819  *      @skb: buffer to segment
2820  *      @features: features for the output path (see dev->features)
2821  *      @tx_path: whether it is called in TX path
2822  *
2823  *      This function segments the given skb and returns a list of segments.
2824  *
2825  *      It may return NULL if the skb requires no segmentation.  This is
2826  *      only possible when GSO is used for verifying header integrity.
2827  *
2828  *      Segmentation preserves SKB_SGO_CB_OFFSET bytes of previous skb cb.
2829  */
2830 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
2831                                   netdev_features_t features, bool tx_path)
2832 {
2833         struct sk_buff *segs;
2834 
2835         if (unlikely(skb_needs_check(skb, tx_path))) {
2836                 int err;
2837 
2838                 /* We're going to init ->check field in TCP or UDP header */
2839                 err = skb_cow_head(skb, 0);
2840                 if (err < 0)
2841                         return ERR_PTR(err);
2842         }
2843 
2844         /* Only report GSO partial support if it will enable us to
2845          * support segmentation on this frame without needing additional
2846          * work.
2847          */
2848         if (features & NETIF_F_GSO_PARTIAL) {
2849                 netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
2850                 struct net_device *dev = skb->dev;
2851 
2852                 partial_features |= dev->features & dev->gso_partial_features;
2853                 if (!skb_gso_ok(skb, features | partial_features))
2854                         features &= ~NETIF_F_GSO_PARTIAL;
2855         }
2856 
2857         BUILD_BUG_ON(SKB_SGO_CB_OFFSET +
2858                      sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
2859 
2860         SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2861         SKB_GSO_CB(skb)->encap_level = 0;
2862 
2863         skb_reset_mac_header(skb);
2864         skb_reset_mac_len(skb);
2865 
2866         segs = skb_mac_gso_segment(skb, features);
2867 
2868         if (unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
2869                 skb_warn_bad_offload(skb);
2870 
2871         return segs;
2872 }
2873 EXPORT_SYMBOL(__skb_gso_segment);
2874 
2875 /* Take action when hardware reception checksum errors are detected. */
2876 #ifdef CONFIG_BUG
2877 void netdev_rx_csum_fault(struct net_device *dev)
2878 {
2879         if (net_ratelimit()) {
2880                 pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2881                 dump_stack();
2882         }
2883 }
2884 EXPORT_SYMBOL(netdev_rx_csum_fault);
2885 #endif
2886 
2887 /* Actually, we should eliminate this check as soon as we know, that:
2888  * 1. IOMMU is present and allows to map all the memory.
2889  * 2. No high memory really exists on this machine.
2890  */
2891 
2892 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
2893 {
2894 #ifdef CONFIG_HIGHMEM
2895         int i;
2896 
2897         if (!(dev->features & NETIF_F_HIGHDMA)) {
2898                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2899                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2900 
2901                         if (PageHighMem(skb_frag_page(frag)))
2902                                 return 1;
2903                 }
2904         }
2905 
2906         if (PCI_DMA_BUS_IS_PHYS) {
2907                 struct device *pdev = dev->dev.parent;
2908 
2909                 if (!pdev)
2910                         return 0;
2911                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2912                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2913                         dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2914 
2915                         if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
2916                                 return 1;
2917                 }
2918         }
2919 #endif
2920         return 0;
2921 }
2922 
2923 /* If MPLS offload request, verify we are testing hardware MPLS features
2924  * instead of standard features for the netdev.
2925  */
2926 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
2927 static netdev_features_t net_mpls_features(struct sk_buff *skb,
2928                                            netdev_features_t features,
2929                                            __be16 type)
2930 {
2931         if (eth_p_mpls(type))
2932                 features &= skb->dev->mpls_features;
2933 
2934         return features;
2935 }
2936 #else
2937 static netdev_features_t net_mpls_features(struct sk_buff *skb,
2938                                            netdev_features_t features,
2939                                            __be16 type)
2940 {
2941         return features;
2942 }
2943 #endif
2944 
2945 static netdev_features_t harmonize_features(struct sk_buff *skb,
2946         netdev_features_t features)
2947 {
2948         int tmp;
2949         __be16 type;
2950 
2951         type = skb_network_protocol(skb, &tmp);
2952         features = net_mpls_features(skb, features, type);
2953 
2954         if (skb->ip_summed != CHECKSUM_NONE &&
2955             !can_checksum_protocol(features, type)) {
2956                 features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
2957         }
2958         if (illegal_highdma(skb->dev, skb))
2959                 features &= ~NETIF_F_SG;
2960 
2961         return features;
2962 }
2963 
2964 netdev_features_t passthru_features_check(struct sk_buff *skb,
2965                                           struct net_device *dev,
2966                                           netdev_features_t features)
2967 {
2968         return features;
2969 }
2970 EXPORT_SYMBOL(passthru_features_check);
2971 
2972 static netdev_features_t dflt_features_check(const struct sk_buff *skb,
2973                                              struct net_device *dev,
2974                                              netdev_features_t features)
2975 {
2976         return vlan_features_check(skb, features);
2977 }
2978 
2979 static netdev_features_t gso_features_check(const struct sk_buff *skb,
2980                                             struct net_device *dev,
2981                                             netdev_features_t features)
2982 {
2983         u16 gso_segs = skb_shinfo(skb)->gso_segs;
2984 
2985         if (gso_segs > dev->gso_max_segs)
2986                 return features & ~NETIF_F_GSO_MASK;
2987 
2988         /* Support for GSO partial features requires software
2989          * intervention before we can actually process the packets
2990          * so we need to strip support for any partial features now
2991          * and we can pull them back in after we have partially
2992          * segmented the frame.
2993          */
2994         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
2995                 features &= ~dev->gso_partial_features;
2996 
2997         /* Make sure to clear the IPv4 ID mangling feature if the
2998          * IPv4 header has the potential to be fragmented.
2999          */
3000         if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3001                 struct iphdr *iph = skb->encapsulation ?
3002                                     inner_ip_hdr(skb) : ip_hdr(skb);
3003 
3004                 if (!(iph->frag_off & htons(IP_DF)))
3005                         features &= ~NETIF_F_TSO_MANGLEID;
3006         }
3007 
3008         return features;
3009 }
3010 
3011 netdev_features_t netif_skb_features(struct sk_buff *skb)
3012 {
3013         struct net_device *dev = skb->dev;
3014         netdev_features_t features = dev->features;
3015 
3016         if (skb_is_gso(skb))
3017                 features = gso_features_check(skb, dev, features);
3018 
3019         /* If encapsulation offload request, verify we are testing
3020          * hardware encapsulation features instead of standard
3021          * features for the netdev
3022          */
3023         if (skb->encapsulation)
3024                 features &= dev->hw_enc_features;
3025 
3026         if (skb_vlan_tagged(skb))
3027                 features = netdev_intersect_features(features,
3028                                                      dev->vlan_features |
3029                                                      NETIF_F_HW_VLAN_CTAG_TX |
3030                                                      NETIF_F_HW_VLAN_STAG_TX);
3031 
3032         if (dev->netdev_ops->ndo_features_check)
3033                 features &= dev->netdev_ops->ndo_features_check(skb, dev,
3034                                                                 features);
3035         else
3036                 features &= dflt_features_check(skb, dev, features);
3037 
3038         return harmonize_features(skb, features);
3039 }
3040 EXPORT_SYMBOL(netif_skb_features);
3041 
3042 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3043                     struct netdev_queue *txq, bool more)
3044 {
3045         unsigned int len;
3046         int rc;
3047 
3048         if (!list_empty(&ptype_all) || !list_empty(&dev->ptype_all))
3049                 dev_queue_xmit_nit(skb, dev);
3050 
3051         len = skb->len;
3052         trace_net_dev_start_xmit(skb, dev);
3053         rc = netdev_start_xmit(skb, dev, txq, more);
3054         trace_net_dev_xmit(skb, rc, dev, len);
3055 
3056         return rc;
3057 }
3058 
3059 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3060                                     struct netdev_queue *txq, int *ret)
3061 {
3062         struct sk_buff *skb = first;
3063         int rc = NETDEV_TX_OK;
3064 
3065         while (skb) {
3066                 struct sk_buff *next = skb->next;
3067 
3068                 skb->next = NULL;
3069                 rc = xmit_one(skb, dev, txq, next != NULL);
3070                 if (unlikely(!dev_xmit_complete(rc))) {
3071                         skb->next = next;
3072                         goto out;
3073                 }
3074 
3075                 skb = next;
3076                 if (netif_xmit_stopped(txq) && skb) {
3077                         rc = NETDEV_TX_BUSY;
3078                         break;
3079                 }
3080         }
3081 
3082 out:
3083         *ret = rc;
3084         return skb;
3085 }
3086 
3087 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3088                                           netdev_features_t features)
3089 {
3090         if (skb_vlan_tag_present(skb) &&
3091             !vlan_hw_offload_capable(features, skb->vlan_proto))
3092                 skb = __vlan_hwaccel_push_inside(skb);
3093         return skb;
3094 }
3095 
3096 int skb_csum_hwoffload_help(struct sk_buff *skb,
3097                             const netdev_features_t features)
3098 {
3099         if (unlikely(skb->csum_not_inet))
3100                 return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3101                         skb_crc32c_csum_help(skb);
3102 
3103         return !!(features & NETIF_F_CSUM_MASK) ? 0 : skb_checksum_help(skb);
3104 }
3105 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3106 
3107 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3108 {
3109         netdev_features_t features;
3110 
3111         features = netif_skb_features(skb);
3112         skb = validate_xmit_vlan(skb, features);
3113         if (unlikely(!skb))
3114                 goto out_null;
3115 
3116         if (netif_needs_gso(skb, features)) {
3117                 struct sk_buff *segs;
3118 
3119                 segs = skb_gso_segment(skb, features);
3120                 if (IS_ERR(segs)) {
3121                         goto out_kfree_skb;
3122                 } else if (segs) {
3123                         consume_skb(skb);
3124                         skb = segs;
3125                 }
3126         } else {
3127                 if (skb_needs_linearize(skb, features) &&
3128                     __skb_linearize(skb))
3129                         goto out_kfree_skb;
3130 
3131                 /* If packet is not checksummed and device does not
3132                  * support checksumming for this protocol, complete
3133                  * checksumming here.
3134                  */
3135                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3136                         if (skb->encapsulation)
3137                                 skb_set_inner_transport_header(skb,
3138                                                                skb_checksum_start_offset(skb));
3139                         else
3140                                 skb_set_transport_header(skb,
3141                                                          skb_checksum_start_offset(skb));
3142                         if (skb_csum_hwoffload_help(skb, features))
3143                                 goto out_kfree_skb;
3144                 }
3145         }
3146 
3147         skb = validate_xmit_xfrm(skb, features, again);
3148 
3149         return skb;
3150 
3151 out_kfree_skb:
3152         kfree_skb(skb);
3153 out_null:
3154         atomic_long_inc(&dev->tx_dropped);
3155         return NULL;
3156 }
3157 
3158 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3159 {
3160         struct sk_buff *next, *head = NULL, *tail;
3161 
3162         for (; skb != NULL; skb = next) {
3163                 next = skb->next;
3164                 skb->next = NULL;
3165 
3166                 /* in case skb wont be segmented, point to itself */
3167                 skb->prev = skb;
3168 
3169                 skb = validate_xmit_skb(skb, dev, again);
3170                 if (!skb)
3171                         continue;
3172 
3173                 if (!head)
3174                         head = skb;
3175                 else
3176                         tail->next = skb;
3177                 /* If skb was segmented, skb->prev points to
3178                  * the last segment. If not, it still contains skb.
3179                  */
3180                 tail = skb->prev;
3181         }
3182         return head;
3183 }
3184 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3185 
3186 static void qdisc_pkt_len_init(struct sk_buff *skb)
3187 {
3188         const struct skb_shared_info *shinfo = skb_shinfo(skb);
3189 
3190         qdisc_skb_cb(skb)->pkt_len = skb->len;
3191 
3192         /* To get more precise estimation of bytes sent on wire,
3193          * we add to pkt_len the headers size of all segments
3194          */
3195         if (shinfo->gso_size)  {
3196                 unsigned int hdr_len;
3197                 u16 gso_segs = shinfo->gso_segs;
3198 
3199                 /* mac layer + network layer */
3200                 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
3201 
3202                 /* + transport layer */
3203                 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3204                         const struct tcphdr *th;
3205                         struct tcphdr _tcphdr;
3206 
3207                         th = skb_header_pointer(skb, skb_transport_offset(skb),
3208                                                 sizeof(_tcphdr), &_tcphdr);
3209                         if (likely(th))
3210                                 hdr_len += __tcp_hdrlen(th);
3211                 } else {
3212                         struct udphdr _udphdr;
3213 
3214                         if (skb_header_pointer(skb, skb_transport_offset(skb),
3215                                                sizeof(_udphdr), &_udphdr))
3216                                 hdr_len += sizeof(struct udphdr);
3217                 }
3218 
3219                 if (shinfo->gso_type & SKB_GSO_DODGY)
3220                         gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3221                                                 shinfo->gso_size);
3222 
3223                 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3224         }
3225 }
3226 
3227 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3228                                  struct net_device *dev,
3229                                  struct netdev_queue *txq)
3230 {
3231         spinlock_t *root_lock = qdisc_lock(q);
3232         struct sk_buff *to_free = NULL;
3233         bool contended;
3234         int rc;
3235 
3236         qdisc_calculate_pkt_len(skb, q);
3237 
3238         if (q->flags & TCQ_F_NOLOCK) {
3239                 if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3240                         __qdisc_drop(skb, &to_free);
3241                         rc = NET_XMIT_DROP;
3242                 } else {
3243                         rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
3244                         __qdisc_run(q);
3245                 }
3246 
3247                 if (unlikely(to_free))
3248                         kfree_skb_list(to_free);
3249                 return rc;
3250         }
3251 
3252         /*
3253          * Heuristic to force contended enqueues to serialize on a
3254          * separate lock before trying to get qdisc main lock.
3255          * This permits qdisc->running owner to get the lock more
3256          * often and dequeue packets faster.
3257          */
3258         contended = qdisc_is_running(q);
3259         if (unlikely(contended))
3260                 spin_lock(&q->busylock);
3261 
3262         spin_lock(root_lock);
3263         if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3264                 __qdisc_drop(skb, &to_free);
3265                 rc = NET_XMIT_DROP;
3266         } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3267                    qdisc_run_begin(q)) {
3268                 /*
3269                  * This is a work-conserving queue; there are no old skbs
3270                  * waiting to be sent out; and the qdisc is not running -
3271                  * xmit the skb directly.
3272                  */
3273 
3274                 qdisc_bstats_update(q, skb);
3275 
3276                 if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3277                         if (unlikely(contended)) {
3278                                 spin_unlock(&q->busylock);
3279                                 contended = false;
3280                         }
3281                         __qdisc_run(q);
3282                 }
3283 
3284                 qdisc_run_end(q);
3285                 rc = NET_XMIT_SUCCESS;
3286         } else {
3287                 rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
3288                 if (qdisc_run_begin(q)) {
3289                         if (unlikely(contended)) {
3290                                 spin_unlock(&q->busylock);
3291                                 contended = false;
3292                         }
3293                         __qdisc_run(q);
3294                         qdisc_run_end(q);
3295                 }
3296         }
3297         spin_unlock(root_lock);
3298         if (unlikely(to_free))
3299                 kfree_skb_list(to_free);
3300         if (unlikely(contended))
3301                 spin_unlock(&q->busylock);
3302         return rc;
3303 }
3304 
3305 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3306 static void skb_update_prio(struct sk_buff *skb)
3307 {
3308         const struct netprio_map *map;
3309         const struct sock *sk;
3310         unsigned int prioidx;
3311 
3312         if (skb->priority)
3313                 return;
3314         map = rcu_dereference_bh(skb->dev->priomap);
3315         if (!map)
3316                 return;
3317         sk = skb_to_full_sk(skb);
3318         if (!sk)
3319                 return;
3320 
3321         prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3322 
3323         if (prioidx < map->priomap_len)
3324                 skb->priority = map->priomap[prioidx];
3325 }
3326 #else
3327 #define skb_update_prio(skb)
3328 #endif
3329 
3330 DEFINE_PER_CPU(int, xmit_recursion);
3331 EXPORT_SYMBOL(xmit_recursion);
3332 
3333 /**
3334  *      dev_loopback_xmit - loop back @skb
3335  *      @net: network namespace this loopback is happening in
3336  *      @sk:  sk needed to be a netfilter okfn
3337  *      @skb: buffer to transmit
3338  */
3339 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3340 {
3341         skb_reset_mac_header(skb);
3342         __skb_pull(skb, skb_network_offset(skb));
3343         skb->pkt_type = PACKET_LOOPBACK;
3344         skb->ip_summed = CHECKSUM_UNNECESSARY;
3345         WARN_ON(!skb_dst(skb));
3346         skb_dst_force(skb);
3347         netif_rx_ni(skb);
3348         return 0;
3349 }
3350 EXPORT_SYMBOL(dev_loopback_xmit);
3351 
3352 #ifdef CONFIG_NET_EGRESS
3353 static struct sk_buff *
3354 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3355 {
3356         struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3357         struct tcf_result cl_res;
3358 
3359         if (!miniq)
3360                 return skb;
3361 
3362         /* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3363         mini_qdisc_bstats_cpu_update(miniq, skb);
3364 
3365         switch (tcf_classify(skb, miniq->filter_list, &cl_res, false)) {
3366         case TC_ACT_OK:
3367         case TC_ACT_RECLASSIFY:
3368                 skb->tc_index = TC_H_MIN(cl_res.classid);
3369                 break;
3370         case TC_ACT_SHOT:
3371                 mini_qdisc_qstats_cpu_drop(miniq);
3372                 *ret = NET_XMIT_DROP;
3373                 kfree_skb(skb);
3374                 return NULL;
3375         case TC_ACT_STOLEN:
3376         case TC_ACT_QUEUED:
3377         case TC_ACT_TRAP:
3378                 *ret = NET_XMIT_SUCCESS;
3379                 consume_skb(skb);
3380                 return NULL;
3381         case TC_ACT_REDIRECT:
3382                 /* No need to push/pop skb's mac_header here on egress! */
3383                 skb_do_redirect(skb);
3384                 *ret = NET_XMIT_SUCCESS;
3385                 return NULL;
3386         default:
3387                 break;
3388         }
3389 
3390         return skb;
3391 }
3392 #endif /* CONFIG_NET_EGRESS */
3393 
3394 static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
3395 {
3396 #ifdef CONFIG_XPS
3397         struct xps_dev_maps *dev_maps;
3398         struct xps_map *map;
3399         int queue_index = -1;
3400 
3401         rcu_read_lock();
3402         dev_maps = rcu_dereference(dev->xps_maps);
3403         if (dev_maps) {
3404                 unsigned int tci = skb->sender_cpu - 1;
3405 
3406                 if (dev->num_tc) {
3407                         tci *= dev->num_tc;
3408                         tci += netdev_get_prio_tc_map(dev, skb->priority);
3409                 }
3410 
3411                 map = rcu_dereference(dev_maps->cpu_map[tci]);
3412                 if (map) {
3413                         if (map->len == 1)
3414                                 queue_index = map->queues[0];
3415                         else
3416                                 queue_index = map->queues[reciprocal_scale(skb_get_hash(skb),
3417                                                                            map->len)];
3418                         if (unlikely(queue_index >= dev->real_num_tx_queues))
3419                                 queue_index = -1;
3420                 }
3421         }
3422         rcu_read_unlock();
3423 
3424         return queue_index;
3425 #else
3426         return -1;
3427 #endif
3428 }
3429 
3430 static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb)
3431 {
3432         struct sock *sk = skb->sk;
3433         int queue_index = sk_tx_queue_get(sk);
3434 
3435         if (queue_index < 0 || skb->ooo_okay ||
3436             queue_index >= dev->real_num_tx_queues) {
3437                 int new_index = get_xps_queue(dev, skb);
3438 
3439                 if (new_index < 0)
3440                         new_index = skb_tx_hash(dev, skb);
3441 
3442                 if (queue_index != new_index && sk &&
3443                     sk_fullsock(sk) &&
3444                     rcu_access_pointer(sk->sk_dst_cache))
3445                         sk_tx_queue_set(sk, new_index);
3446 
3447                 queue_index = new_index;
3448         }
3449 
3450         return queue_index;
3451 }
3452 
3453 struct netdev_queue *netdev_pick_tx(struct net_device *dev,
3454                                     struct sk_buff *skb,
3455                                     void *accel_priv)
3456 {
3457         int queue_index = 0;
3458 
3459 #ifdef CONFIG_XPS
3460         u32 sender_cpu = skb->sender_cpu - 1;
3461 
3462         if (sender_cpu >= (u32)NR_CPUS)
3463                 skb->sender_cpu = raw_smp_processor_id() + 1;
3464 #endif
3465 
3466         if (dev->real_num_tx_queues != 1) {
3467                 const struct net_device_ops *ops = dev->netdev_ops;
3468 
3469                 if (ops->ndo_select_queue)
3470                         queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
3471                                                             __netdev_pick_tx);
3472                 else
3473                         queue_index = __netdev_pick_tx(dev, skb);
3474 
3475                 queue_index = netdev_cap_txqueue(dev, queue_index);
3476         }
3477 
3478         skb_set_queue_mapping(skb, queue_index);
3479         return netdev_get_tx_queue(dev, queue_index);
3480 }
3481 
3482 /**
3483  *      __dev_queue_xmit - transmit a buffer
3484  *      @skb: buffer to transmit
3485  *      @accel_priv: private data used for L2 forwarding offload
3486  *
3487  *      Queue a buffer for transmission to a network device. The caller must
3488  *      have set the device and priority and built the buffer before calling
3489  *      this function. The function can be called from an interrupt.
3490  *
3491  *      A negative errno code is returned on a failure. A success does not
3492  *      guarantee the frame will be transmitted as it may be dropped due
3493  *      to congestion or traffic shaping.
3494  *
3495  * -----------------------------------------------------------------------------------
3496  *      I notice this method can also return errors from the queue disciplines,
3497  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
3498  *      be positive.
3499  *
3500  *      Regardless of the return value, the skb is consumed, so it is currently
3501  *      difficult to retry a send to this method.  (You can bump the ref count
3502  *      before sending to hold a reference for retry if you are careful.)
3503  *
3504  *      When calling this method, interrupts MUST be enabled.  This is because
3505  *      the BH enable code must have IRQs enabled so that it will not deadlock.
3506  *          --BLG
3507  */
3508 static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
3509 {
3510         struct net_device *dev = skb->dev;
3511         struct netdev_queue *txq;
3512         struct Qdisc *q;
3513         int rc = -ENOMEM;
3514         bool again = false;
3515 
3516         skb_reset_mac_header(skb);
3517 
3518         if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
3519                 __skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED);
3520 
3521         /* Disable soft irqs for various locks below. Also
3522          * stops preemption for RCU.
3523          */
3524         rcu_read_lock_bh();
3525 
3526         skb_update_prio(skb);
3527 
3528         qdisc_pkt_len_init(skb);
3529 #ifdef CONFIG_NET_CLS_ACT
3530         skb->tc_at_ingress = 0;
3531 # ifdef CONFIG_NET_EGRESS
3532         if (static_key_false(&egress_needed)) {
3533                 skb = sch_handle_egress(skb, &rc, dev);
3534                 if (!skb)
3535                         goto out;
3536         }
3537 # endif
3538 #endif
3539         /* If device/qdisc don't need skb->dst, release it right now while
3540          * its hot in this cpu cache.
3541          */
3542         if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
3543                 skb_dst_drop(skb);
3544         else
3545                 skb_dst_force(skb);
3546 
3547         txq = netdev_pick_tx(dev, skb, accel_priv);
3548         q = rcu_dereference_bh(txq->qdisc);
3549 
3550         trace_net_dev_queue(skb);
3551         if (q->enqueue) {
3552                 rc = __dev_xmit_skb(skb, q, dev, txq);
3553                 goto out;
3554         }
3555 
3556         /* The device has no queue. Common case for software devices:
3557          * loopback, all the sorts of tunnels...
3558 
3559          * Really, it is unlikely that netif_tx_lock protection is necessary
3560          * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
3561          * counters.)
3562          * However, it is possible, that they rely on protection
3563          * made by us here.
3564 
3565          * Check this and shot the lock. It is not prone from deadlocks.
3566          *Either shot noqueue qdisc, it is even simpler 8)
3567          */
3568         if (dev->flags & IFF_UP) {
3569                 int cpu = smp_processor_id(); /* ok because BHs are off */
3570 
3571                 if (txq->xmit_lock_owner != cpu) {
3572                         if (unlikely(__this_cpu_read(xmit_recursion) >
3573                                      XMIT_RECURSION_LIMIT))
3574                                 goto recursion_alert;
3575 
3576                         skb = validate_xmit_skb(skb, dev, &again);
3577                         if (!skb)
3578                                 goto out;
3579 
3580                         HARD_TX_LOCK(dev, txq, cpu);
3581 
3582                         if (!netif_xmit_stopped(txq)) {
3583                                 __this_cpu_inc(xmit_recursion);
3584                                 skb = dev_hard_start_xmit(skb, dev, txq, &rc);
3585                                 __this_cpu_dec(xmit_recursion);
3586                                 if (dev_xmit_complete(rc)) {
3587                                         HARD_TX_UNLOCK(dev, txq);
3588                                         goto out;
3589                                 }
3590                         }
3591                         HARD_TX_UNLOCK(dev, txq);
3592                         net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
3593                                              dev->name);
3594                 } else {
3595                         /* Recursion is detected! It is possible,
3596                          * unfortunately
3597                          */
3598 recursion_alert:
3599                         net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
3600                                              dev->name);
3601                 }
3602         }
3603 
3604         rc = -ENETDOWN;
3605         rcu_read_unlock_bh();
3606 
3607         atomic_long_inc(&dev->tx_dropped);
3608         kfree_skb_list(skb);
3609         return rc;
3610 out:
3611         rcu_read_unlock_bh();
3612         return rc;
3613 }
3614 
3615 int dev_queue_xmit(struct sk_buff *skb)
3616 {
3617         return __dev_queue_xmit(skb, NULL);
3618 }
3619 EXPORT_SYMBOL(dev_queue_xmit);
3620 
3621 int dev_queue_xmit_accel(struct sk_buff *skb, void *accel_priv)
3622 {
3623         return __dev_queue_xmit(skb, accel_priv);
3624 }
3625 EXPORT_SYMBOL(dev_queue_xmit_accel);
3626 
3627 
3628 /*************************************************************************
3629  *                      Receiver routines
3630  *************************************************************************/
3631 
3632 int netdev_max_backlog __read_mostly = 1000;
3633 EXPORT_SYMBOL(netdev_max_backlog);
3634 
3635 int netdev_tstamp_prequeue __read_mostly = 1;
3636 int netdev_budget __read_mostly = 300;
3637 unsigned int __read_mostly netdev_budget_usecs = 2000;
3638 int weight_p __read_mostly = 64;           /* old backlog weight */
3639 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
3640 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
3641 int dev_rx_weight __read_mostly = 64;
3642 int dev_tx_weight __read_mostly = 64;
3643 
3644 /* Called with irq disabled */
3645 static inline void ____napi_schedule(struct softnet_data *sd,
3646                                      struct napi_struct *napi)
3647 {
3648         list_add_tail(&napi->poll_list, &sd->poll_list);
3649         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
3650 }
3651 
3652 #ifdef CONFIG_RPS
3653 
3654 /* One global table that all flow-based protocols share. */
3655 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
3656 EXPORT_SYMBOL(rps_sock_flow_table);
3657 u32 rps_cpu_mask __read_mostly;
3658 EXPORT_SYMBOL(rps_cpu_mask);
3659 
3660 struct static_key rps_needed __read_mostly;
3661 EXPORT_SYMBOL(rps_needed);
3662 struct static_key rfs_needed __read_mostly;
3663 EXPORT_SYMBOL(rfs_needed);
3664 
3665 static struct rps_dev_flow *
3666 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
3667             struct rps_dev_flow *rflow, u16 next_cpu)
3668 {
3669         if (next_cpu < nr_cpu_ids) {
3670 #ifdef CONFIG_RFS_ACCEL
3671                 struct netdev_rx_queue *rxqueue;
3672                 struct rps_dev_flow_table *flow_table;
3673                 struct rps_dev_flow *old_rflow;
3674                 u32 flow_id;
3675                 u16 rxq_index;
3676                 int rc;
3677 
3678                 /* Should we steer this flow to a different hardware queue? */
3679                 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
3680                     !(dev->features & NETIF_F_NTUPLE))
3681                         goto out;
3682                 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
3683                 if (rxq_index == skb_get_rx_queue(skb))
3684                         goto out;
3685 
3686                 rxqueue = dev->_rx + rxq_index;
3687                 flow_table = rcu_dereference(rxqueue->rps_flow_table);
3688                 if (!flow_table)
3689                         goto out;
3690                 flow_id = skb_get_hash(skb) & flow_table->mask;
3691                 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
3692                                                         rxq_index, flow_id);
3693                 if (rc < 0)
3694                         goto out;
3695                 old_rflow = rflow;
3696                 rflow = &flow_table->flows[flow_id];
3697                 rflow->filter = rc;
3698                 if (old_rflow->filter == rflow->filter)
3699                         old_rflow->filter = RPS_NO_FILTER;
3700         out:
3701 #endif
3702                 rflow->last_qtail =
3703                         per_cpu(softnet_data, next_cpu).input_queue_head;
3704         }
3705 
3706         rflow->cpu = next_cpu;
3707         return rflow;
3708 }
3709 
3710 /*
3711  * get_rps_cpu is called from netif_receive_skb and returns the target
3712  * CPU from the RPS map of the receiving queue for a given skb.
3713  * rcu_read_lock must be held on entry.
3714  */
3715 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
3716                        struct rps_dev_flow **rflowp)
3717 {
3718         const struct rps_sock_flow_table *sock_flow_table;
3719         struct netdev_rx_queue *rxqueue = dev->_rx;
3720         struct rps_dev_flow_table *flow_table;
3721         struct rps_map *map;
3722         int cpu = -1;
3723         u32 tcpu;
3724         u32 hash;
3725 
3726         if (skb_rx_queue_recorded(skb)) {
3727                 u16 index = skb_get_rx_queue(skb);
3728 
3729                 if (unlikely(index >= dev->real_num_rx_queues)) {
3730                         WARN_ONCE(dev->real_num_rx_queues > 1,
3731                                   "%s received packet on queue %u, but number "
3732                                   "of RX queues is %u\n",
3733                                   dev->name, index, dev->real_num_rx_queues);
3734                         goto done;
3735                 }
3736                 rxqueue += index;
3737         }
3738 
3739         /* Avoid computing hash if RFS/RPS is not active for this rxqueue */
3740 
3741         flow_table = rcu_dereference(rxqueue->rps_flow_table);
3742         map = rcu_dereference(rxqueue->rps_map);
3743         if (!flow_table && !map)
3744                 goto done;
3745 
3746         skb_reset_network_header(skb);
3747         hash = skb_get_hash(skb);
3748         if (!hash)
3749                 goto done;
3750 
3751         sock_flow_table = rcu_dereference(rps_sock_flow_table);
3752         if (flow_table && sock_flow_table) {
3753                 struct rps_dev_flow *rflow;
3754                 u32 next_cpu;
3755                 u32 ident;
3756 
3757                 /* First check into global flow table if there is a match */
3758                 ident = sock_flow_table->ents[hash & sock_flow_table->mask];
3759                 if ((ident ^ hash) & ~rps_cpu_mask)
3760                         goto try_rps;
3761 
3762                 next_cpu = ident & rps_cpu_mask;
3763 
3764                 /* OK, now we know there is a match,
3765                  * we can look at the local (per receive queue) flow table
3766                  */
3767                 rflow = &flow_table->flows[hash & flow_table->mask];
3768                 tcpu = rflow->cpu;
3769 
3770                 /*
3771                  * If the desired CPU (where last recvmsg was done) is
3772                  * different from current CPU (one in the rx-queue flow
3773                  * table entry), switch if one of the following holds:
3774                  *   - Current CPU is unset (>= nr_cpu_ids).
3775                  *   - Current CPU is offline.
3776                  *   - The current CPU's queue tail has advanced beyond the
3777                  *     last packet that was enqueued using this table entry.
3778                  *     This guarantees that all previous packets for the flow
3779                  *     have been dequeued, thus preserving in order delivery.
3780                  */
3781                 if (unlikely(tcpu != next_cpu) &&
3782                     (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
3783                      ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
3784                       rflow->last_qtail)) >= 0)) {
3785                         tcpu = next_cpu;
3786                         rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3787                 }
3788 
3789                 if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
3790                         *rflowp = rflow;
3791                         cpu = tcpu;
3792                         goto done;
3793                 }
3794         }
3795 
3796 try_rps:
3797 
3798         if (map) {
3799                 tcpu = map->cpus[reciprocal_scale(hash, map->len)];
3800                 if (cpu_online(tcpu)) {
3801                         cpu = tcpu;
3802                         goto done;
3803                 }
3804         }
3805 
3806 done:
3807         return cpu;
3808 }
3809 
3810 #ifdef CONFIG_RFS_ACCEL
3811 
3812 /**
3813  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
3814  * @dev: Device on which the filter was set
3815  * @rxq_index: RX queue index
3816  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
3817  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
3818  *
3819  * Drivers that implement ndo_rx_flow_steer() should periodically call
3820  * this function for each installed filter and remove the filters for
3821  * which it returns %true.
3822  */
3823 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
3824                          u32 flow_id, u16 filter_id)
3825 {
3826         struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
3827         struct rps_dev_flow_table *flow_table;
3828         struct rps_dev_flow *rflow;
3829         bool expire = true;
3830         unsigned int cpu;
3831 
3832         rcu_read_lock();
3833         flow_table = rcu_dereference(rxqueue->rps_flow_table);
3834         if (flow_table && flow_id <= flow_table->mask) {
3835                 rflow = &flow_table->flows[flow_id];
3836                 cpu = READ_ONCE(rflow->cpu);
3837                 if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
3838                     ((int)(per_cpu(softnet_data, cpu).input_queue_head -
3839                            rflow->last_qtail) <
3840                      (int)(10 * flow_table->mask)))
3841                         expire = false;
3842         }
3843         rcu_read_unlock();
3844         return expire;
3845 }
3846 EXPORT_SYMBOL(rps_may_expire_flow);
3847 
3848 #endif /* CONFIG_RFS_ACCEL */
3849 
3850 /* Called from hardirq (IPI) context */
3851 static void rps_trigger_softirq(void *data)
3852 {
3853         struct softnet_data *sd = data;
3854 
3855         ____napi_schedule(sd, &sd->backlog);
3856         sd->received_rps++;
3857 }
3858 
3859 #endif /* CONFIG_RPS */
3860 
3861 /*
3862  * Check if this softnet_data structure is another cpu one
3863  * If yes, queue it to our IPI list and return 1
3864  * If no, return 0
3865  */
3866 static int rps_ipi_queued(struct softnet_data *sd)
3867 {
3868 #ifdef CONFIG_RPS
3869         struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
3870 
3871         if (sd != mysd) {
3872                 sd->rps_ipi_next = mysd->rps_ipi_list;
3873                 mysd->rps_ipi_list = sd;
3874 
3875                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
3876                 return 1;
3877         }
3878 #endif /* CONFIG_RPS */
3879         return 0;
3880 }
3881 
3882 #ifdef CONFIG_NET_FLOW_LIMIT
3883 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
3884 #endif
3885 
3886 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
3887 {
3888 #ifdef CONFIG_NET_FLOW_LIMIT
3889         struct sd_flow_limit *fl;
3890         struct softnet_data *sd;
3891         unsigned int old_flow, new_flow;
3892 
3893         if (qlen < (netdev_max_backlog >> 1))
3894                 return false;
3895 
3896         sd = this_cpu_ptr(&softnet_data);
3897 
3898         rcu_read_lock();
3899         fl = rcu_dereference(sd->flow_limit);
3900         if (fl) {
3901                 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
3902                 old_flow = fl->history[fl->history_head];
3903                 fl->history[fl->history_head] = new_flow;
3904 
3905                 fl->history_head++;
3906                 fl->history_head &= FLOW_LIMIT_HISTORY - 1;
3907 
3908                 if (likely(fl->buckets[old_flow]))
3909                         fl->buckets[old_flow]--;
3910 
3911                 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
3912                         fl->count++;
3913                         rcu_read_unlock();
3914                         return true;
3915                 }
3916         }
3917         rcu_read_unlock();
3918 #endif
3919         return false;
3920 }
3921 
3922 /*
3923  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
3924  * queue (may be a remote CPU queue).
3925  */
3926 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
3927                               unsigned int *qtail)
3928 {
3929         struct softnet_data *sd;
3930         unsigned long flags;
3931         unsigned int qlen;
3932 
3933         sd = &per_cpu(softnet_data, cpu);
3934 
3935         local_irq_save(flags);
3936 
3937         rps_lock(sd);
3938         if (!netif_running(skb->dev))
3939                 goto drop;
3940         qlen = skb_queue_len(&sd->input_pkt_queue);
3941         if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3942                 if (qlen) {
3943 enqueue:
3944                         __skb_queue_tail(&sd->input_pkt_queue, skb);
3945                         input_queue_tail_incr_save(sd, qtail);
3946                         rps_unlock(sd);
3947                         local_irq_restore(flags);
3948                         return NET_RX_SUCCESS;
3949                 }
3950 
3951                 /* Schedule NAPI for backlog device
3952                  * We can use non atomic operation since we own the queue lock
3953                  */
3954                 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
3955                         if (!rps_ipi_queued(sd))
3956                                 ____napi_schedule(sd, &sd->backlog);
3957                 }
3958                 goto enqueue;
3959         }
3960 
3961 drop:
3962         sd->dropped++;
3963         rps_unlock(sd);
3964 
3965         local_irq_restore(flags);
3966 
3967         atomic_long_inc(&skb->dev->rx_dropped);
3968         kfree_skb(skb);
3969         return NET_RX_DROP;
3970 }
3971 
3972 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
3973 {
3974         struct net_device *dev = skb->dev;
3975         struct netdev_rx_queue *rxqueue;
3976 
3977         rxqueue = dev->_rx;
3978 
3979         if (skb_rx_queue_recorded(skb)) {
3980                 u16 index = skb_get_rx_queue(skb);
3981 
3982                 if (unlikely(index >= dev->real_num_rx_queues)) {
3983                         WARN_ONCE(dev->real_num_rx_queues > 1,
3984                                   "%s received packet on queue %u, but number "
3985                                   "of RX queues is %u\n",
3986                                   dev->name, index, dev->real_num_rx_queues);
3987 
3988                         return rxqueue; /* Return first rxqueue */
3989                 }
3990                 rxqueue += index;
3991         }
3992         return rxqueue;
3993 }
3994 
3995 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
3996                                      struct bpf_prog *xdp_prog)
3997 {
3998         struct netdev_rx_queue *rxqueue;
3999         u32 metalen, act = XDP_DROP;
4000         struct xdp_buff xdp;
4001         void *orig_data;
4002         int hlen, off;
4003         u32 mac_len;
4004 
4005         /* Reinjected packets coming from act_mirred or similar should
4006          * not get XDP generic processing.
4007          */
4008         if (skb_cloned(skb))
4009                 return XDP_PASS;
4010 
4011         /* XDP packets must be linear and must have sufficient headroom
4012          * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4013          * native XDP provides, thus we need to do it here as well.
4014          */
4015         if (skb_is_nonlinear(skb) ||
4016             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4017                 int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4018                 int troom = skb->tail + skb->data_len - skb->end;
4019 
4020                 /* In case we have to go down the path and also linearize,
4021                  * then lets do the pskb_expand_head() work just once here.
4022                  */
4023                 if (pskb_expand_head(skb,
4024                                      hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4025                                      troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4026                         goto do_drop;
4027                 if (skb_linearize(skb))
4028                         goto do_drop;
4029         }
4030 
4031         /* The XDP program wants to see the packet starting at the MAC
4032          * header.
4033          */
4034         mac_len = skb->data - skb_mac_header(skb);
4035         hlen = skb_headlen(skb) + mac_len;
4036         xdp.data = skb->data - mac_len;
4037         xdp.data_meta = xdp.data;
4038         xdp.data_end = xdp.data + hlen;
4039         xdp.data_hard_start = skb->data - skb_headroom(skb);
4040         orig_data = xdp.data;
4041 
4042         rxqueue = netif_get_rxqueue(skb);
4043         xdp.rxq = &rxqueue->xdp_rxq;
4044 
4045         act = bpf_prog_run_xdp(xdp_prog, &xdp);
4046 
4047         off = xdp.data - orig_data;
4048         if (off > 0)
4049                 __skb_pull(skb, off);
4050         else if (off < 0)
4051                 __skb_push(skb, -off);
4052         skb->mac_header += off;
4053 
4054         switch (act) {
4055         case XDP_REDIRECT:
4056         case XDP_TX:
4057                 __skb_push(skb, mac_len);
4058                 break;
4059         case XDP_PASS:
4060                 metalen = xdp.data - xdp.data_meta;
4061                 if (metalen)
4062                         skb_metadata_set(skb, metalen);
4063                 break;
4064         default:
4065                 bpf_warn_invalid_xdp_action(act);
4066                 /* fall through */
4067         case XDP_ABORTED:
4068                 trace_xdp_exception(skb->dev, xdp_prog, act);
4069                 /* fall through */
4070         case XDP_DROP:
4071         do_drop:
4072                 kfree_skb(skb);
4073                 break;
4074         }
4075 
4076         return act;
4077 }
4078 
4079 /* When doing generic XDP we have to bypass the qdisc layer and the
4080  * network taps in order to match in-driver-XDP behavior.
4081  */
4082 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4083 {
4084         struct net_device *dev = skb->dev;
4085         struct netdev_queue *txq;
4086         bool free_skb = true;
4087         int cpu, rc;
4088 
4089         txq = netdev_pick_tx(dev, skb, NULL);
4090         cpu = smp_processor_id();
4091         HARD_TX_LOCK(dev, txq, cpu);
4092         if (!netif_xmit_stopped(txq)) {
4093                 rc = netdev_start_xmit(skb, dev, txq, 0);
4094                 if (dev_xmit_complete(rc))
4095                         free_skb = false;
4096         }
4097         HARD_TX_UNLOCK(dev, txq);
4098         if (free_skb) {
4099                 trace_xdp_exception(dev, xdp_prog, XDP_TX);
4100                 kfree_skb(skb);
4101         }
4102 }
4103 EXPORT_SYMBOL_GPL(generic_xdp_tx);
4104 
4105 static struct static_key generic_xdp_needed __read_mostly;
4106 
4107 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4108 {
4109         if (xdp_prog) {
4110                 u32 act = netif_receive_generic_xdp(skb, xdp_prog);
4111                 int err;
4112 
4113                 if (act != XDP_PASS) {
4114                         switch (act) {
4115                         case XDP_REDIRECT:
4116                                 err = xdp_do_generic_redirect(skb->dev, skb,
4117                                                               xdp_prog);
4118                                 if (err)
4119                                         goto out_redir;
4120                         /* fallthru to submit skb */
4121                         case XDP_TX:
4122                                 generic_xdp_tx(skb, xdp_prog);
4123                                 break;
4124                         }
4125                         return XDP_DROP;
4126                 }
4127         }
4128         return XDP_PASS;
4129 out_redir:
4130         kfree_skb(skb);
4131         return XDP_DROP;
4132 }
4133 EXPORT_SYMBOL_GPL(do_xdp_generic);
4134 
4135 static int netif_rx_internal(struct sk_buff *skb)
4136 {
4137         int ret;
4138 
4139         net_timestamp_check(netdev_tstamp_prequeue, skb);
4140 
4141         trace_netif_rx(skb);
4142 
4143         if (static_key_false(&generic_xdp_needed)) {
4144                 int ret;
4145 
4146                 preempt_disable();
4147                 rcu_read_lock();
4148                 ret = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
4149                 rcu_read_unlock();
4150                 preempt_enable();
4151 
4152                 /* Consider XDP consuming the packet a success from
4153                  * the netdev point of view we do not want to count
4154                  * this as an error.
4155                  */
4156                 if (ret != XDP_PASS)
4157                         return NET_RX_SUCCESS;
4158         }
4159 
4160 #ifdef CONFIG_RPS
4161         if (static_key_false(&rps_needed)) {
4162                 struct rps_dev_flow voidflow, *rflow = &voidflow;
4163                 int cpu;
4164 
4165                 preempt_disable();
4166                 rcu_read_lock();
4167 
4168                 cpu = get_rps_cpu(skb->dev, skb, &rflow);
4169                 if (cpu < 0)
4170                         cpu = smp_processor_id();
4171 
4172                 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4173 
4174                 rcu_read_unlock();
4175                 preempt_enable();
4176         } else
4177 #endif
4178         {
4179                 unsigned int qtail;
4180 
4181                 ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
4182                 put_cpu();
4183         }
4184         return ret;
4185 }
4186 
4187 /**
4188  *      netif_rx        -       post buffer to the network code
4189  *      @skb: buffer to post
4190  *
4191  *      This function receives a packet from a device driver and queues it for
4192  *      the upper (protocol) levels to process.  It always succeeds. The buffer
4193  *      may be dropped during processing for congestion control or by the
4194  *      protocol layers.
4195  *
4196  *      return values:
4197  *      NET_RX_SUCCESS  (no congestion)
4198  *      NET_RX_DROP     (packet was dropped)
4199  *
4200  */
4201 
4202 int netif_rx(struct sk_buff *skb)
4203 {
4204         trace_netif_rx_entry(skb);
4205 
4206         return netif_rx_internal(skb);
4207 }
4208 EXPORT_SYMBOL(netif_rx);
4209 
4210 int netif_rx_ni(struct sk_buff *skb)
4211 {
4212         int err;
4213 
4214         trace_netif_rx_ni_entry(skb);
4215 
4216         preempt_disable();
4217         err = netif_rx_internal(skb);
4218         if (local_softirq_pending())
4219                 do_softirq();
4220         preempt_enable();
4221 
4222         return err;
4223 }
4224 EXPORT_SYMBOL(netif_rx_ni);
4225 
4226 static __latent_entropy void net_tx_action(struct softirq_action *h)
4227 {
4228         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
4229 
4230         if (sd->completion_queue) {
4231                 struct sk_buff *clist;
4232 
4233                 local_irq_disable();
4234                 clist = sd->completion_queue;
4235                 sd->completion_queue = NULL;
4236                 local_irq_enable();
4237 
4238                 while (clist) {
4239                         struct sk_buff *skb = clist;
4240 
4241                         clist = clist->next;
4242 
4243                         WARN_ON(refcount_read(&skb->users));
4244                         if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
4245                                 trace_consume_skb(skb);
4246                         else
4247                                 trace_kfree_skb(skb, net_tx_action);
4248 
4249                         if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
4250                                 __kfree_skb(skb);
4251                         else
4252                                 __kfree_skb_defer(skb);
4253                 }
4254 
4255                 __kfree_skb_flush();
4256         }
4257 
4258         if (sd->output_queue) {
4259                 struct Qdisc *head;
4260 
4261                 local_irq_disable();
4262                 head = sd->output_queue;
4263                 sd->output_queue = NULL;
4264                 sd->output_queue_tailp = &sd->output_queue;
4265                 local_irq_enable();
4266 
4267                 while (head) {
4268                         struct Qdisc *q = head;
4269                         spinlock_t *root_lock = NULL;
4270 
4271                         head = head->next_sched;
4272 
4273                         if (!(q->flags & TCQ_F_NOLOCK)) {
4274                                 root_lock = qdisc_lock(q);
4275                                 spin_lock(root_lock);
4276                         }
4277                         /* We need to make sure head->next_sched is read
4278                          * before clearing __QDISC_STATE_SCHED
4279                          */
4280                         smp_mb__before_atomic();
4281                         clear_bit(__QDISC_STATE_SCHED, &q->state);
4282                         qdisc_run(q);
4283                         if (root_lock)
4284                                 spin_unlock(root_lock);
4285                 }
4286         }
4287 
4288         xfrm_dev_backlog(sd);
4289 }
4290 
4291 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
4292 /* This hook is defined here for ATM LANE */
4293 int (*br_fdb_test_addr_hook)(struct net_device *dev,
4294                              unsigned char *addr) __read_mostly;
4295 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
4296 #endif
4297 
4298 static inline struct sk_buff *
4299 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
4300                    struct net_device *orig_dev)
4301 {
4302 #ifdef CONFIG_NET_CLS_ACT
4303         struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
4304         struct tcf_result cl_res;
4305 
4306         /* If there's at least one ingress present somewhere (so
4307          * we get here via enabled static key), remaining devices
4308          * that are not configured with an ingress qdisc will bail
4309          * out here.
4310          */
4311         if (!miniq)
4312                 return skb;
4313 
4314         if (*pt_prev) {
4315                 *ret = deliver_skb(skb, *pt_prev, orig_dev);
4316                 *pt_prev = NULL;
4317         }
4318 
4319         qdisc_skb_cb(skb)->pkt_len = skb->len;
4320         skb->tc_at_ingress = 1;
4321         mini_qdisc_bstats_cpu_update(miniq, skb);
4322 
4323         switch (tcf_classify(skb, miniq->filter_list, &cl_res, false)) {
4324         case TC_ACT_OK:
4325         case TC_ACT_RECLASSIFY:
4326                 skb->tc_index = TC_H_MIN(cl_res.classid);
4327                 break;
4328         case TC_ACT_SHOT:
4329                 mini_qdisc_qstats_cpu_drop(miniq);
4330                 kfree_skb(skb);
4331                 return NULL;
4332         case TC_ACT_STOLEN:
4333         case TC_ACT_QUEUED:
4334         case TC_ACT_TRAP:
4335                 consume_skb(skb);
4336                 return NULL;
4337         case TC_ACT_REDIRECT:
4338                 /* skb_mac_header check was done by cls/act_bpf, so
4339                  * we can safely push the L2 header back before
4340                  * redirecting to another netdev
4341                  */
4342                 __skb_push(skb, skb->mac_len);
4343                 skb_do_redirect(skb);
4344                 return NULL;
4345         default:
4346                 break;
4347         }
4348 #endif /* CONFIG_NET_CLS_ACT */
4349         return skb;
4350 }
4351 
4352 /**
4353  *      netdev_is_rx_handler_busy - check if receive handler is registered
4354  *      @dev: device to check
4355  *
4356  *      Check if a receive handler is already registered for a given device.
4357  *      Return true if there one.
4358  *
4359  *      The caller must hold the rtnl_mutex.
4360  */
4361 bool netdev_is_rx_handler_busy(struct net_device *dev)
4362 {
4363         ASSERT_RTNL();
4364         return dev && rtnl_dereference(dev->rx_handler);
4365 }
4366 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
4367 
4368 /**
4369  *      netdev_rx_handler_register - register receive handler
4370  *      @dev: device to register a handler for
4371  *      @rx_handler: receive handler to register
4372  *      @rx_handler_data: data pointer that is used by rx handler
4373  *
4374  *      Register a receive handler for a device. This handler will then be
4375  *      called from __netif_receive_skb. A negative errno code is returned
4376  *      on a failure.
4377  *
4378  *      The caller must hold the rtnl_mutex.
4379  *
4380  *      For a general description of rx_handler, see enum rx_handler_result.
4381  */
4382 int netdev_rx_handler_register(struct net_device *dev,
4383                                rx_handler_func_t *rx_handler,
4384                                void *rx_handler_data)
4385 {
4386         if (netdev_is_rx_handler_busy(dev))
4387                 return -EBUSY;
4388 
4389         if (dev->priv_flags & IFF_NO_RX_HANDLER)
4390                 return -EINVAL;
4391 
4392         /* Note: rx_handler_data must be set before rx_handler */
4393         rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
4394         rcu_assign_pointer(dev->rx_handler, rx_handler);
4395 
4396         return 0;
4397 }
4398 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
4399 
4400 /**
4401  *      netdev_rx_handler_unregister - unregister receive handler
4402  *      @dev: device to unregister a handler from
4403  *
4404  *      Unregister a receive handler from a device.
4405  *
4406  *      The caller must hold the rtnl_mutex.
4407  */
4408 void netdev_rx_handler_unregister(struct net_device *dev)
4409 {
4410 
4411         ASSERT_RTNL();
4412         RCU_INIT_POINTER(dev->rx_handler, NULL);
4413         /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
4414          * section has a guarantee to see a non NULL rx_handler_data
4415          * as well.
4416          */
4417         synchronize_net();
4418         RCU_INIT_POINTER(dev->rx_handler_data, NULL);
4419 }
4420 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
4421 
4422 /*
4423  * Limit the use of PFMEMALLOC reserves to those protocols that implement
4424  * the special handling of PFMEMALLOC skbs.
4425  */
4426 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
4427 {
4428         switch (skb->protocol) {
4429         case htons(ETH_P_ARP):
4430         case htons(ETH_P_IP):
4431         case htons(ETH_P_IPV6):
4432         case htons(ETH_P_8021Q):
4433         case htons(ETH_P_8021AD):
4434                 return true;
4435         default:
4436                 return false;
4437         }
4438 }
4439 
4440 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
4441                              int *ret, struct net_device *orig_dev)
4442 {
4443 #ifdef CONFIG_NETFILTER_INGRESS
4444         if (nf_hook_ingress_active(skb)) {
4445                 int ingress_retval;
4446 
4447                 if (*pt_prev) {
4448                         *ret = deliver_skb(skb, *pt_prev, orig_dev);
4449                         *pt_prev = NULL;
4450                 }
4451 
4452                 rcu_read_lock();
4453                 ingress_retval = nf_hook_ingress(skb);
4454                 rcu_read_unlock();
4455                 return ingress_retval;
4456         }
4457 #endif /* CONFIG_NETFILTER_INGRESS */
4458         return 0;
4459 }
4460 
4461 static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
4462 {
4463         struct packet_type *ptype, *pt_prev;
4464         rx_handler_func_t *rx_handler;
4465         struct net_device *orig_dev;
4466         bool deliver_exact = false;
4467         int ret = NET_RX_DROP;
4468         __be16 type;
4469 
4470         net_timestamp_check(!netdev_tstamp_prequeue, skb);
4471 
4472         trace_netif_receive_skb(skb);
4473 
4474         orig_dev = skb->dev;
4475 
4476         skb_reset_network_header(skb);
4477         if (!skb_transport_header_was_set(skb))
4478                 skb_reset_transport_header(skb);
4479         skb_reset_mac_len(skb);
4480 
4481         pt_prev = NULL;
4482 
4483 another_round:
4484         skb->skb_iif = skb->dev->ifindex;
4485 
4486         __this_cpu_inc(softnet_data.processed);
4487 
4488         if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
4489             skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
4490                 skb = skb_vlan_untag(skb);
4491                 if (unlikely(!skb))
4492                         goto out;
4493         }
4494 
4495         if (skb_skip_tc_classify(skb))
4496                 goto skip_classify;
4497 
4498         if (pfmemalloc)
4499                 goto skip_taps;
4500 
4501         list_for_each_entry_rcu(ptype, &ptype_all, list) {
4502                 if (pt_prev)
4503                         ret = deliver_skb(skb, pt_prev, orig_dev);
4504                 pt_prev = ptype;
4505         }
4506 
4507         list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
4508                 if (pt_prev)
4509                         ret = deliver_skb(skb, pt_prev, orig_dev);
4510                 pt_prev = ptype;
4511         }
4512 
4513 skip_taps:
4514 #ifdef CONFIG_NET_INGRESS
4515         if (static_key_false(&ingress_needed)) {
4516                 skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev);
4517                 if (!skb)
4518                         goto out;
4519 
4520                 if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
4521                         goto out;
4522         }
4523 #endif
4524         skb_reset_tc(skb);
4525 skip_classify:
4526         if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
4527                 goto drop;
4528 
4529         if (skb_vlan_tag_present(skb)) {
4530                 if (pt_prev) {
4531                         ret = deliver_skb(skb, pt_prev, orig_dev);
4532                         pt_prev = NULL;
4533                 }
4534                 if (vlan_do_receive(&skb))
4535                         goto another_round;
4536                 else if (unlikely(!skb))
4537                         goto out;
4538         }
4539 
4540         rx_handler = rcu_dereference(skb->dev->rx_handler);
4541         if (rx_handler) {
4542                 if (pt_prev) {
4543                         ret = deliver_skb(skb, pt_prev, orig_dev);
4544                         pt_prev = NULL;
4545                 }
4546                 switch (rx_handler(&skb)) {
4547                 case RX_HANDLER_CONSUMED:
4548                         ret = NET_RX_SUCCESS;
4549                         goto out;
4550                 case RX_HANDLER_ANOTHER:
4551                         goto another_round;
4552                 case RX_HANDLER_EXACT:
4553                         deliver_exact = true;
4554                 case RX_HANDLER_PASS:
4555                         break;
4556                 default:
4557                         BUG();
4558                 }
4559         }
4560 
4561         if (unlikely(skb_vlan_tag_present(skb))) {
4562                 if (skb_vlan_tag_get_id(skb))
4563                         skb->pkt_type = PACKET_OTHERHOST;
4564                 /* Note: we might in the future use prio bits
4565                  * and set skb->priority like in vlan_do_receive()
4566                  * For the time being, just ignore Priority Code Point
4567                  */
4568                 skb->vlan_tci = 0;
4569         }
4570 
4571         type = skb->protocol;
4572 
4573         /* deliver only exact match when indicated */
4574         if (likely(!deliver_exact)) {
4575                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
4576                                        &ptype_base[ntohs(type) &
4577                                                    PTYPE_HASH_MASK]);
4578         }
4579 
4580         deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
4581                                &orig_dev->ptype_specific);
4582 
4583         if (unlikely(skb->dev != orig_dev)) {
4584                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
4585                                        &skb->dev->ptype_specific);
4586         }
4587 
4588         if (pt_prev) {
4589                 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
4590                         goto drop;
4591                 else
4592                         ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
4593         } else {
4594 drop:
4595                 if (!deliver_exact)
4596                         atomic_long_inc(&skb->dev->rx_dropped);
4597                 else
4598                         atomic_long_inc(&skb->dev->rx_nohandler);
4599                 kfree_skb(skb);
4600                 /* Jamal, now you will not able to escape explaining
4601                  * me how you were going to use this. :-)
4602                  */
4603                 ret = NET_RX_DROP;
4604         }
4605 
4606 out:
4607         return ret;
4608 }
4609 
4610 /**
4611  *      netif_receive_skb_core - special purpose version of netif_receive_skb
4612  *      @skb: buffer to process
4613  *
4614  *      More direct receive version of netif_receive_skb().  It should
4615  *      only be used by callers that have a need to skip RPS and Generic XDP.
4616  *      Caller must also take care of handling if (page_is_)pfmemalloc.
4617  *
4618  *      This function may only be called from softirq context and interrupts
4619  *      should be enabled.
4620  *
4621  *      Return values (usually ignored):
4622  *      NET_RX_SUCCESS: no congestion
4623  *      NET_RX_DROP: packet was dropped
4624  */
4625 int netif_receive_skb_core(struct sk_buff *skb)
4626 {
4627         int ret;
4628 
4629         rcu_read_lock();
4630         ret = __netif_receive_skb_core(skb, false);
4631         rcu_read_unlock();
4632 
4633         return ret;
4634 }
4635 EXPORT_SYMBOL(netif_receive_skb_core);
4636 
4637 static int __netif_receive_skb(struct sk_buff *skb)
4638 {
4639         int ret;
4640 
4641         if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
4642                 unsigned int noreclaim_flag;
4643 
4644                 /*
4645                  * PFMEMALLOC skbs are special, they should
4646                  * - be delivered to SOCK_MEMALLOC sockets only
4647                  * - stay away from userspace
4648                  * - have bounded memory usage
4649                  *
4650                  * Use PF_MEMALLOC as this saves us from propagating the allocation
4651                  * context down to all allocation sites.
4652                  */
4653                 noreclaim_flag = memalloc_noreclaim_save();
4654                 ret = __netif_receive_skb_core(skb, true);
4655                 memalloc_noreclaim_restore(noreclaim_flag);
4656         } else
4657                 ret = __netif_receive_skb_core(skb, false);
4658 
4659         return ret;
4660 }
4661 
4662 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
4663 {
4664         struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
4665         struct bpf_prog *new = xdp->prog;
4666         int ret = 0;
4667 
4668         switch (xdp->command) {
4669         case XDP_SETUP_PROG:
4670                 rcu_assign_pointer(dev->xdp_prog, new);
4671                 if (old)
4672                         bpf_prog_put(old);
4673 
4674                 if (old && !new) {
4675                         static_key_slow_dec(&generic_xdp_needed);
4676                 } else if (new && !old) {
4677                         static_key_slow_inc(&generic_xdp_needed);
4678                         dev_disable_lro(dev);
4679                         dev_disable_gro_hw(dev);
4680                 }
4681                 break;
4682 
4683         case XDP_QUERY_PROG:
4684                 xdp->prog_attached = !!old;
4685                 xdp->prog_id = old ? old->aux->id : 0;
4686                 break;
4687 
4688         default:
4689                 ret = -EINVAL;
4690                 break;
4691         }
4692 
4693         return ret;
4694 }
4695 
4696 static int netif_receive_skb_internal(struct sk_buff *skb)
4697 {
4698         int ret;
4699 
4700         net_timestamp_check(netdev_tstamp_prequeue, skb);
4701 
4702         if (skb_defer_rx_timestamp(skb))
4703                 return NET_RX_SUCCESS;
4704 
4705         if (static_key_false(&generic_xdp_needed)) {
4706                 int ret;
4707 
4708                 preempt_disable();
4709                 rcu_read_lock();
4710                 ret = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
4711                 rcu_read_unlock();
4712                 preempt_enable();
4713 
4714                 if (ret != XDP_PASS)
4715                         return NET_RX_DROP;
4716         }
4717 
4718         rcu_read_lock();
4719 #ifdef CONFIG_RPS
4720         if (static_key_false(&rps_needed)) {
4721                 struct rps_dev_flow voidflow, *rflow = &voidflow;
4722                 int cpu = get_rps_cpu(skb->dev, skb, &rflow);
4723 
4724                 if (cpu >= 0) {
4725                         ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4726                         rcu_read_unlock();
4727                         return ret;
4728                 }
4729         }
4730 #endif
4731         ret = __netif_receive_skb(skb);
4732         rcu_read_unlock();
4733         return ret;
4734 }
4735 
4736 /**
4737  *      netif_receive_skb - process receive buffer from network
4738  *      @skb: buffer to process
4739  *
4740  *      netif_receive_skb() is the main receive data processing function.
4741  *      It always succeeds. The buffer may be dropped during processing
4742  *      for congestion control or by the protocol layers.
4743  *
4744  *      This function may only be called from softirq context and interrupts
4745  *      should be enabled.
4746  *
4747  *      Return values (usually ignored):
4748  *      NET_RX_SUCCESS: no congestion
4749  *      NET_RX_DROP: packet was dropped
4750  */
4751 int netif_receive_skb(struct sk_buff *skb)
4752 {
4753         trace_netif_receive_skb_entry(skb);
4754 
4755         return netif_receive_skb_internal(skb);
4756 }
4757 EXPORT_SYMBOL(netif_receive_skb);
4758 
4759 DEFINE_PER_CPU(struct work_struct, flush_works);
4760 
4761 /* Network device is going away, flush any packets still pending */
4762 static void flush_backlog(struct work_struct *work)
4763 {
4764         struct sk_buff *skb, *tmp;
4765         struct softnet_data *sd;
4766 
4767         local_bh_disable();
4768         sd = this_cpu_ptr(&softnet_data);
4769 
4770         local_irq_disable();
4771         rps_lock(sd);
4772         skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
4773                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
4774                         __skb_unlink(skb, &sd->input_pkt_queue);
4775                         kfree_skb(skb);
4776                         input_queue_head_incr(sd);
4777                 }
4778         }
4779         rps_unlock(sd);
4780         local_irq_enable();
4781 
4782         skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
4783                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
4784                         __skb_unlink(skb, &sd->process_queue);
4785                         kfree_skb(skb);
4786                         input_queue_head_incr(sd);
4787                 }
4788         }
4789         local_bh_enable();
4790 }
4791 
4792 static void flush_all_backlogs(void)
4793 {
4794         unsigned int cpu;
4795 
4796         get_online_cpus();
4797 
4798         for_each_online_cpu(cpu)
4799                 queue_work_on(cpu, system_highpri_wq,
4800                               per_cpu_ptr(&flush_works, cpu));
4801 
4802         for_each_online_cpu(cpu)
4803                 flush_work(per_cpu_ptr(&flush_works, cpu));
4804 
4805         put_online_cpus();
4806 }
4807 
4808 static int napi_gro_complete(struct sk_buff *skb)
4809 {
4810         struct packet_offload *ptype;
4811         __be16 type = skb->protocol;
4812         struct list_head *head = &offload_base;
4813         int err = -ENOENT;
4814 
4815         BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
4816 
4817         if (NAPI_GRO_CB(skb)->count == 1) {
4818                 skb_shinfo(skb)->gso_size = 0;
4819                 goto out;
4820         }
4821 
4822         rcu_read_lock();
4823         list_for_each_entry_rcu(ptype, head, list) {
4824                 if (ptype->type != type || !ptype->callbacks.gro_complete)
4825                         continue;
4826 
4827                 err = ptype->callbacks.gro_complete(skb, 0);
4828                 break;
4829         }
4830         rcu_read_unlock();
4831 
4832         if (err) {
4833                 WARN_ON(&ptype->list == head);
4834                 kfree_skb(skb);
4835                 return NET_RX_SUCCESS;
4836         }
4837 
4838 out:
4839         return netif_receive_skb_internal(skb);
4840 }
4841 
4842 /* napi->gro_list contains packets ordered by age.
4843  * youngest packets at the head of it.
4844  * Complete skbs in reverse order to reduce latencies.
4845  */
4846 void napi_gro_flush(struct napi_struct *napi, bool flush_old)
4847 {
4848         struct sk_buff *skb, *prev = NULL;
4849 
4850         /* scan list and build reverse chain */
4851         for (skb = napi->gro_list; skb != NULL; skb = skb->next) {
4852                 skb->prev = prev;
4853                 prev = skb;
4854         }
4855 
4856         for (skb = prev; skb; skb = prev) {
4857                 skb->next = NULL;
4858 
4859                 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
4860                         return;
4861 
4862                 prev = skb->prev;
4863                 napi_gro_complete(skb);
4864                 napi->gro_count--;
4865         }
4866 
4867         napi->gro_list = NULL;
4868 }
4869 EXPORT_SYMBOL(napi_gro_flush);
4870 
4871 static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb)
4872 {
4873         struct sk_buff *p;
4874         unsigned int maclen = skb->dev->hard_header_len;
4875         u32 hash = skb_get_hash_raw(skb);
4876 
4877         for (p = napi->gro_list; p; p = p->next) {
4878                 unsigned long diffs;
4879 
4880                 NAPI_GRO_CB(p)->flush = 0;
4881 
4882                 if (hash != skb_get_hash_raw(p)) {
4883                         NAPI_GRO_CB(p)->same_flow = 0;
4884                         continue;
4885                 }
4886 
4887                 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
4888                 diffs |= p->vlan_tci ^ skb->vlan_tci;
4889                 diffs |= skb_metadata_dst_cmp(p, skb);
4890                 diffs |= skb_metadata_differs(p, skb);
4891                 if (maclen == ETH_HLEN)
4892                         diffs |= compare_ether_header(skb_mac_header(p),
4893                                                       skb_mac_header(skb));
4894                 else if (!diffs)
4895                         diffs = memcmp(skb_mac_header(p),
4896                                        skb_mac_header(skb),
4897                                        maclen);
4898                 NAPI_GRO_CB(p)->same_flow = !diffs;
4899         }
4900 }
4901 
4902 static void skb_gro_reset_offset(struct sk_buff *skb)
4903 {
4904         const struct skb_shared_info *pinfo = skb_shinfo(skb);
4905         const skb_frag_t *frag0 = &pinfo->frags[0];
4906 
4907         NAPI_GRO_CB(skb)->data_offset = 0;
4908         NAPI_GRO_CB(skb)->frag0 = NULL;
4909         NAPI_GRO_CB(skb)->frag0_len = 0;
4910 
4911         if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
4912             pinfo->nr_frags &&
4913             !PageHighMem(skb_frag_page(frag0))) {
4914                 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
4915                 NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
4916                                                     skb_frag_size(frag0),
4917                                                     skb->end - skb->tail);
4918         }
4919 }
4920 
4921 static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
4922 {
4923         struct skb_shared_info *pinfo = skb_shinfo(skb);
4924 
4925         BUG_ON(skb->end - skb->tail < grow);
4926 
4927         memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
4928 
4929         skb->data_len -= grow;
4930         skb->tail += grow;
4931 
4932         pinfo->frags[0].page_offset += grow;
4933         skb_frag_size_sub(&pinfo->frags[0], grow);
4934 
4935         if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
4936                 skb_frag_unref(skb, 0);
4937                 memmove(pinfo->frags, pinfo->frags + 1,
4938                         --pinfo->nr_frags * sizeof(pinfo->frags[0]));
4939         }
4940 }
4941 
4942 static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
4943 {
4944         struct sk_buff **pp = NULL;
4945         struct packet_offload *ptype;
4946         __be16 type = skb->protocol;
4947         struct list_head *head = &offload_base;
4948         int same_flow;
4949         enum gro_result ret;
4950         int grow;
4951 
4952         if (netif_elide_gro(skb->dev))
4953                 goto normal;
4954 
4955         gro_list_prepare(napi, skb);
4956 
4957         rcu_read_lock();
4958         list_for_each_entry_rcu(ptype, head, list) {
4959                 if (ptype->type != type || !ptype->callbacks.gro_receive)
4960                         continue;
4961 
4962                 skb_set_network_header(skb, skb_gro_offset(skb));
4963                 skb_reset_mac_len(skb);
4964                 NAPI_GRO_CB(skb)->same_flow = 0;
4965                 NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
4966                 NAPI_GRO_CB(skb)->free = 0;
4967                 NAPI_GRO_CB(skb)->encap_mark = 0;
4968                 NAPI_GRO_CB(skb)->recursion_counter = 0;
4969                 NAPI_GRO_CB(skb)->is_fou = 0;
4970                 NAPI_GRO_CB(skb)->is_atomic = 1;
4971                 NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
4972 
4973                 /* Setup for GRO checksum validation */
4974                 switch (skb->ip_summed) {
4975                 case CHECKSUM_COMPLETE:
4976                         NAPI_GRO_CB(skb)->csum = skb->csum;
4977                         NAPI_GRO_CB(skb)->csum_valid = 1;
4978                         NAPI_GRO_CB(skb)->csum_cnt = 0;
4979                         break;
4980                 case CHECKSUM_UNNECESSARY:
4981                         NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
4982                         NAPI_GRO_CB(skb)->csum_valid = 0;
4983                         break;
4984                 default:
4985                         NAPI_GRO_CB(skb)->csum_cnt = 0;
4986                         NAPI_GRO_CB(skb)->csum_valid = 0;
4987                 }
4988 
4989                 pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
4990                 break;
4991         }
4992         rcu_read_unlock();
4993 
4994         if (&ptype->list == head)
4995                 goto normal;
4996 
4997         if (IS_ERR(pp) && PTR_ERR(pp) == -EINPROGRESS) {
4998                 ret = GRO_CONSUMED;
4999                 goto ok;
5000         }
5001 
5002         same_flow = NAPI_GRO_CB(skb)->same_flow;
5003         ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
5004 
5005         if (pp) {
5006                 struct sk_buff *nskb = *pp;
5007 
5008                 *pp = nskb->next;
5009                 nskb->next = NULL;
5010                 napi_gro_complete(nskb);
5011                 napi->gro_count--;
5012         }
5013 
5014         if (same_flow)
5015                 goto ok;
5016 
5017         if (NAPI_GRO_CB(skb)->flush)
5018                 goto normal;
5019 
5020         if (unlikely(napi->gro_count >= MAX_GRO_SKBS)) {
5021                 struct sk_buff *nskb = napi->gro_list;
5022 
5023                 /* locate the end of the list to select the 'oldest' flow */
5024                 while (nskb->next) {
5025                         pp = &nskb->next;
5026                         nskb = *pp;
5027                 }
5028                 *pp = NULL;
5029                 nskb->next = NULL;
5030                 napi_gro_complete(nskb);
5031         } else {
5032                 napi->gro_count++;
5033         }
5034         NAPI_GRO_CB(skb)->count = 1;
5035         NAPI_GRO_CB(skb)->age = jiffies;
5036         NAPI_GRO_CB(skb)->last = skb;
5037         skb_shinfo(skb)->gso_size = skb_gro_len(skb);
5038         skb->next = napi->gro_list;
5039         napi->gro_list = skb;
5040         ret = GRO_HELD;
5041 
5042 pull:
5043         grow = skb_gro_offset(skb) - skb_headlen(skb);
5044         if (grow > 0)
5045                 gro_pull_from_frag0(skb, grow);
5046 ok:
5047         return ret;
5048 
5049 normal:
5050         ret = GRO_NORMAL;
5051         goto pull;
5052 }
5053 
5054 struct packet_offload *gro_find_receive_by_type(__be16 type)
5055 {
5056         struct list_head *offload_head = &offload_base;
5057         struct packet_offload *ptype;
5058 
5059         list_for_each_entry_rcu(ptype, offload_head, list) {
5060                 if (ptype->type != type || !ptype->callbacks.gro_receive)
5061                         continue;
5062                 return ptype;
5063         }
5064         return NULL;
5065 }
5066 EXPORT_SYMBOL(gro_find_receive_by_type);
5067 
5068 struct packet_offload *gro_find_complete_by_type(__be16 type)
5069 {
5070         struct list_head *offload_head = &offload_base;
5071         struct packet_offload *ptype;
5072 
5073         list_for_each_entry_rcu(ptype, offload_head, list) {
5074                 if (ptype->type != type || !ptype->callbacks.gro_complete)
5075                         continue;
5076                 return ptype;
5077         }
5078         return NULL;
5079 }
5080 EXPORT_SYMBOL(gro_find_complete_by_type);
5081 
5082 static void napi_skb_free_stolen_head(struct sk_buff *skb)
5083 {
5084         skb_dst_drop(skb);
5085         secpath_reset(skb);
5086         kmem_cache_free(skbuff_head_cache, skb);
5087 }
5088 
5089 static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
5090 {
5091         switch (ret) {
5092         case GRO_NORMAL:
5093                 if (netif_receive_skb_internal(skb))
5094                         ret = GRO_DROP;
5095                 break;
5096 
5097         case GRO_DROP:
5098                 kfree_skb(skb);
5099                 break;
5100 
5101         case GRO_MERGED_FREE:
5102                 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
5103                         napi_skb_free_stolen_head(skb);
5104                 else
5105                         __kfree_skb(skb);
5106                 break;
5107 
5108         case GRO_HELD:
5109         case GRO_MERGED:
5110         case GRO_CONSUMED:
5111                 break;
5112         }
5113 
5114         return ret;
5115 }
5116 
5117 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
5118 {
5119         skb_mark_napi_id(skb, napi);
5120         trace_napi_gro_receive_entry(skb);
5121 
5122         skb_gro_reset_offset(skb);
5123 
5124         return napi_skb_finish(dev_gro_receive(napi, skb), skb);
5125 }
5126 EXPORT_SYMBOL(napi_gro_receive);
5127 
5128 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
5129 {
5130         if (unlikely(skb->pfmemalloc)) {
5131                 consume_skb(skb);
5132                 return;
5133         }
5134         __skb_pull(skb, skb_headlen(skb));
5135         /* restore the reserve we had after netdev_alloc_skb_ip_align() */
5136         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
5137         skb->vlan_tci = 0;
5138         skb->dev = napi->dev;
5139         skb->skb_iif = 0;
5140         skb->encapsulation = 0;
5141         skb_shinfo(skb)->gso_type = 0;
5142         skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
5143         secpath_reset(skb);
5144 
5145         napi->skb = skb;
5146 }
5147 
5148 struct sk_buff *napi_get_frags(struct napi_struct *napi)
5149 {
5150         struct sk_buff *skb = napi->skb;
5151 
5152         if (!skb) {
5153                 skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
5154                 if (skb) {
5155                         napi->skb = skb;
5156                         skb_mark_napi_id(skb, napi);
5157                 }
5158         }
5159         return skb;
5160 }
5161 EXPORT_SYMBOL(napi_get_frags);
5162 
5163 static gro_result_t napi_frags_finish(struct napi_struct *napi,
5164                                       struct sk_buff *skb,
5165                                       gro_result_t ret)
5166 {
5167         switch (ret) {
5168         case GRO_NORMAL:
5169         case GRO_HELD:
5170                 __skb_push(skb, ETH_HLEN);
5171                 skb->protocol = eth_type_trans(skb, skb->dev);
5172                 if (ret == GRO_NORMAL && netif_receive_skb_internal(skb))
5173                         ret = GRO_DROP;
5174                 break;
5175 
5176         case GRO_DROP:
5177                 napi_reuse_skb(napi, skb);
5178                 break;
5179 
5180         case GRO_MERGED_FREE:
5181                 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
5182                         napi_skb_free_stolen_head(skb);
5183                 else
5184                         napi_reuse_skb(napi, skb);
5185                 break;
5186 
5187         case GRO_MERGED:
5188         case GRO_CONSUMED:
5189                 break;
5190         }
5191 
5192         return ret;
5193 }
5194 
5195 /* Upper GRO stack assumes network header starts at gro_offset=0
5196  * Drivers could call both napi_gro_frags() and napi_gro_receive()
5197  * We copy ethernet header into skb->data to have a common layout.
5198  */
5199 static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
5200 {
5201         struct sk_buff *skb = napi->skb;
5202         const struct ethhdr *eth;
5203         unsigned int hlen = sizeof(*eth);
5204 
5205         napi->skb = NULL;
5206 
5207         skb_reset_mac_header(skb);
5208         skb_gro_reset_offset(skb);
5209 
5210         eth = skb_gro_header_fast(skb, 0);
5211         if (unlikely(skb_gro_header_hard(skb, hlen))) {
5212                 eth = skb_gro_header_slow(skb, hlen, 0);
5213                 if (unlikely(!eth)) {
5214                         net_warn_ratelimited("%s: dropping impossible skb from %s\n",
5215                                              __func__, napi->dev->name);
5216                         napi_reuse_skb(napi, skb);
5217                         return NULL;
5218                 }
5219         } else {
5220                 gro_pull_from_frag0(skb, hlen);
5221                 NAPI_GRO_CB(skb)->frag0 += hlen;
5222                 NAPI_GRO_CB(skb)->frag0_len -= hlen;
5223         }
5224         __skb_pull(skb, hlen);
5225 
5226         /*
5227          * This works because the only protocols we care about don't require
5228          * special handling.
5229          * We'll fix it up properly in napi_frags_finish()
5230          */
5231         skb->protocol = eth->h_proto;
5232 
5233         return skb;
5234 }
5235 
5236 gro_result_t napi_gro_frags(struct napi_struct *napi)
5237 {
5238         struct sk_buff *skb = napi_frags_skb(napi);
5239 
5240         if (!skb)
5241                 return GRO_DROP;
5242 
5243         trace_napi_gro_frags_entry(skb);
5244 
5245         return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
5246 }
5247 EXPORT_SYMBOL(napi_gro_frags);
5248 
5249 /* Compute the checksum from gro_offset and return the folded value
5250  * after adding in any pseudo checksum.
5251  */
5252 __sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
5253 {
5254         __wsum wsum;
5255         __sum16 sum;
5256 
5257         wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
5258 
5259         /* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
5260         sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
5261         if (likely(!sum)) {
5262                 if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
5263                     !skb->csum_complete_sw)
5264                         netdev_rx_csum_fault(skb->dev);
5265         }
5266 
5267         NAPI_GRO_CB(skb)->csum = wsum;
5268         NAPI_GRO_CB(skb)->csum_valid = 1;
5269 
5270         return sum;
5271 }
5272 EXPORT_SYMBOL(__skb_gro_checksum_complete);
5273 
5274 static void net_rps_send_ipi(struct softnet_data *remsd)
5275 {
5276 #ifdef CONFIG_RPS
5277         while (remsd) {
5278                 struct softnet_data *next = remsd->rps_ipi_next;
5279 
5280                 if (cpu_online(remsd->cpu))
5281                         smp_call_function_single_async(remsd->cpu, &remsd->csd);
5282                 remsd = next;
5283         }
5284 #endif
5285 }
5286 
5287 /*
5288  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5289  * Note: called with local irq disabled, but exits with local irq enabled.
5290  */
5291 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5292 {
5293 #ifdef CONFIG_RPS
5294         struct softnet_data *remsd = sd->rps_ipi_list;
5295 
5296         if (remsd) {
5297                 sd->rps_ipi_list = NULL;
5298 
5299                 local_irq_enable();
5300 
5301                 /* Send pending IPI's to kick RPS processing on remote cpus. */
5302                 net_rps_send_ipi(remsd);
5303         } else
5304 #endif
5305                 local_irq_enable();
5306 }
5307 
5308 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5309 {
5310 #ifdef CONFIG_RPS
5311         return sd->rps_ipi_list != NULL;
5312 #else
5313         return false;
5314 #endif
5315 }
5316 
5317 static int process_backlog(struct napi_struct *napi, int quota)
5318 {
5319         struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5320         bool again = true;
5321         int work = 0;
5322 
5323         /* Check if we have pending ipi, its better to send them now,
5324          * not waiting net_rx_action() end.
5325          */
5326         if (sd_has_rps_ipi_waiting(sd)) {
5327                 local_irq_disable();
5328                 net_rps_action_and_irq_enable(sd);
5329         }
5330 
5331         napi->weight = dev_rx_weight;
5332         while (again) {
5333                 struct sk_buff *skb;
5334 
5335                 while ((skb = __skb_dequeue(&sd->process_queue))) {
5336                         rcu_read_lock();
5337                         __netif_receive_skb(skb);
5338                         rcu_read_unlock();
5339                         input_queue_head_incr(sd);
5340                         if (++work >= quota)
5341                                 return work;
5342 
5343                 }
5344 
5345                 local_irq_disable();
5346                 rps_lock(sd);
5347                 if (skb_queue_empty(&sd->input_pkt_queue)) {
5348                         /*
5349                          * Inline a custom version of __napi_complete().
5350                          * only current cpu owns and manipulates this napi,
5351                          * and NAPI_STATE_SCHED is the only possible flag set
5352                          * on backlog.
5353                          * We can use a plain write instead of clear_bit(),
5354                          * and we dont need an smp_mb() memory barrier.
5355                          */
5356                         napi->state = 0;
5357                         again = false;
5358                 } else {
5359                         skb_queue_splice_tail_init(&sd->input_pkt_queue,
5360                                                    &sd->process_queue);
5361                 }
5362                 rps_unlock(sd);
5363                 local_irq_enable();
5364         }
5365 
5366         return work;
5367 }
5368 
5369 /**
5370  * __napi_schedule - schedule for receive
5371  * @n: entry to schedule
5372  *
5373  * The entry's receive function will be scheduled to run.
5374  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5375  */
5376 void __napi_schedule(struct napi_struct *n)
5377 {
5378         unsigned long flags;
5379 
5380         local_irq_save(flags);
5381         ____napi_schedule(this_cpu_ptr(&softnet_data), n);
5382         local_irq_restore(flags);
5383 }
5384 EXPORT_SYMBOL(__napi_schedule);
5385 
5386 /**
5387  *      napi_schedule_prep - check if napi can be scheduled
5388  *      @n: napi context
5389  *
5390  * Test if NAPI routine is already running, and if not mark
5391  * it as running.  This is used as a condition variable
5392  * insure only one NAPI poll instance runs.  We also make
5393  * sure there is no pending NAPI disable.
5394  */
5395 bool napi_schedule_prep(struct napi_struct *n)
5396 {
5397         unsigned long val, new;
5398 
5399         do {
5400                 val = READ_ONCE(n->state);
5401                 if (unlikely(val & NAPIF_STATE_DISABLE))
5402                         return false;
5403                 new = val | NAPIF_STATE_SCHED;
5404 
5405                 /* Sets STATE_MISSED bit if STATE_SCHED was already set
5406                  * This was suggested by Alexander Duyck, as compiler
5407                  * emits better code than :
5408                  * if (val & NAPIF_STATE_SCHED)
5409                  *     new |= NAPIF_STATE_MISSED;
5410                  */
5411                 new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
5412                                                    NAPIF_STATE_MISSED;
5413         } while (cmpxchg(&n->state, val, new) != val);
5414 
5415         return !(val & NAPIF_STATE_SCHED);
5416 }
5417 EXPORT_SYMBOL(napi_schedule_prep);
5418 
5419 /**
5420  * __napi_schedule_irqoff - schedule for receive
5421  * @n: entry to schedule
5422  *
5423  * Variant of __napi_schedule() assuming hard irqs are masked
5424  */
5425 void __napi_schedule_irqoff(struct napi_struct *n)
5426 {
5427         ____napi_schedule(this_cpu_ptr(&softnet_data), n);
5428 }
5429 EXPORT_SYMBOL(__napi_schedule_irqoff);
5430 
5431 bool napi_complete_done(struct napi_struct *n, int work_done)
5432 {
5433         unsigned long flags, val, new;
5434 
5435         /*
5436          * 1) Don't let napi dequeue from the cpu poll list
5437          *    just in case its running on a different cpu.
5438          * 2) If we are busy polling, do nothing here, we have
5439          *    the guarantee we will be called later.
5440          */
5441         if (unlikely(n->state & (NAPIF_STATE_NPSVC |
5442                                  NAPIF_STATE_IN_BUSY_POLL)))
5443                 return false;
5444 
5445         if (n->gro_list) {
5446                 unsigned long timeout = 0;
5447 
5448                 if (work_done)
5449                         timeout = n->dev->gro_flush_timeout;
5450 
5451                 if (timeout)
5452                         hrtimer_start(&n->timer, ns_to_ktime(timeout),
5453                                       HRTIMER_MODE_REL_PINNED);
5454                 else
5455                         napi_gro_flush(n, false);
5456         }
5457         if (unlikely(!list_empty(&n->poll_list))) {
5458                 /* If n->poll_list is not empty, we need to mask irqs */
5459                 local_irq_save(flags);
5460                 list_del_init(&n->poll_list);
5461                 local_irq_restore(flags);
5462         }
5463 
5464         do {
5465                 val = READ_ONCE(n->state);
5466 
5467                 WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
5468 
5469                 new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED);
5470 
5471                 /* If STATE_MISSED was set, leave STATE_SCHED set,
5472                  * because we will call napi->poll() one more time.
5473                  * This C code was suggested by Alexander Duyck to help gcc.
5474                  */
5475                 new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
5476                                                     NAPIF_STATE_SCHED;
5477         } while (cmpxchg(&n->state, val, new) != val);
5478 
5479         if (unlikely(val & NAPIF_STATE_MISSED)) {
5480                 __napi_schedule(n);
5481                 return false;
5482         }
5483 
5484         return true;
5485 }
5486 EXPORT_SYMBOL(napi_complete_done);
5487 
5488 /* must be called under rcu_read_lock(), as we dont take a reference */
5489 static struct napi_struct *napi_by_id(unsigned int napi_id)
5490 {
5491         unsigned int hash = napi_id % HASH_SIZE(napi_hash);
5492         struct napi_struct *napi;
5493 
5494         hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
5495                 if (napi->napi_id == napi_id)
5496                         return napi;
5497 
5498         return NULL;
5499 }
5500 
5501 #if defined(CONFIG_NET_RX_BUSY_POLL)
5502 
5503 #define BUSY_POLL_BUDGET 8
5504 
5505 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
5506 {
5507         int rc;
5508 
5509         /* Busy polling means there is a high chance device driver hard irq
5510          * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
5511          * set in napi_schedule_prep().
5512          * Since we are about to call napi->poll() once more, we can safely
5513          * clear NAPI_STATE_MISSED.
5514          *
5515          * Note: x86 could use a single "lock and ..." instruction
5516          * to perform these two clear_bit()
5517          */
5518         clear_bit(NAPI_STATE_MISSED, &napi->state);
5519         clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
5520 
5521         local_bh_disable();
5522 
5523         /* All we really want here is to re-enable device interrupts.
5524          * Ideally, a new ndo_busy_poll_stop() could avoid another round.
5525          */
5526         rc = napi->poll(napi, BUSY_POLL_BUDGET);
5527         trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
5528         netpoll_poll_unlock(have_poll_lock);
5529         if (rc == BUSY_POLL_BUDGET)
5530                 __napi_schedule(napi);
5531         local_bh_enable();
5532 }
5533 
5534 void napi_busy_loop(unsigned int napi_id,
5535                     bool (*loop_end)(void *, unsigned long),
5536                     void *loop_end_arg)
5537 {
5538         unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
5539         int (*napi_poll)(struct napi_struct *napi, int budget);
5540         void *have_poll_lock = NULL;
5541         struct napi_struct *napi;
5542 
5543 restart:
5544         napi_poll = NULL;
5545 
5546         rcu_read_lock();
5547 
5548         napi = napi_by_id(napi_id);
5549         if (!napi)
5550                 goto out;
5551 
5552         preempt_disable();
5553         for (;;) {
5554                 int work = 0;
5555 
5556                 local_bh_disable();
5557                 if (!napi_poll) {
5558                         unsigned long val = READ_ONCE(napi->state);
5559 
5560                         /* If multiple threads are competing for this napi,
5561                          * we avoid dirtying napi->state as much as we can.
5562                          */
5563                         if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
5564                                    NAPIF_STATE_IN_BUSY_POLL))
5565                                 goto count;
5566                         if (cmpxchg(&napi->state, val,
5567                                     val | NAPIF_STATE_IN_BUSY_POLL |
5568                                           NAPIF_STATE_SCHED) != val)
5569                                 goto count;
5570                         have_poll_lock = netpoll_poll_lock(napi);
5571                         napi_poll = napi->poll;
5572                 }
5573                 work = napi_poll(napi, BUSY_POLL_BUDGET);
5574                 trace_napi_poll(napi, work, BUSY_POLL_BUDGET);
5575 count:
5576                 if (work > 0)
5577                         __NET_ADD_STATS(dev_net(napi->dev),
5578                                         LINUX_MIB_BUSYPOLLRXPACKETS, work);
5579                 local_bh_enable();
5580 
5581                 if (!loop_end || loop_end(loop_end_arg, start_time))
5582                         break;
5583 
5584                 if (unlikely(need_resched())) {
5585                         if (napi_poll)
5586                                 busy_poll_stop(napi, have_poll_lock);
5587                         preempt_enable();
5588                         rcu_read_unlock();
5589                         cond_resched();
5590                         if (loop_end(loop_end_arg, start_time))
5591                                 return;
5592                         goto restart;
5593                 }
5594                 cpu_relax();
5595         }
5596         if (napi_poll)
5597                 busy_poll_stop(napi, have_poll_lock);
5598         preempt_enable();
5599 out:
5600         rcu_read_unlock();
5601 }
5602 EXPORT_SYMBOL(napi_busy_loop);
5603 
5604 #endif /* CONFIG_NET_RX_BUSY_POLL */
5605 
5606 static void napi_hash_add(struct napi_struct *napi)
5607 {
5608         if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state) ||
5609             test_and_set_bit(NAPI_STATE_HASHED, &napi->state))
5610                 return;
5611 
5612         spin_lock(&napi_hash_lock);
5613 
5614         /* 0..NR_CPUS range is reserved for sender_cpu use */
5615         do {
5616                 if (unlikely(++napi_gen_id < MIN_NAPI_ID))
5617                         napi_gen_id = MIN_NAPI_ID;
5618         } while (napi_by_id(napi_gen_id));
5619         napi->napi_id = napi_gen_id;
5620 
5621         hlist_add_head_rcu(&napi->napi_hash_node,
5622                            &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
5623 
5624         spin_unlock(&napi_hash_lock);
5625 }
5626 
5627 /* Warning : caller is responsible to make sure rcu grace period
5628  * is respected before freeing memory containing @napi
5629  */
5630 bool napi_hash_del(struct napi_struct *napi)
5631 {
5632         bool rcu_sync_needed = false;
5633 
5634         spin_lock(&napi_hash_lock);
5635 
5636         if (test_and_clear_bit(NAPI_STATE_HASHED, &napi->state)) {
5637                 rcu_sync_needed = true;
5638                 hlist_del_rcu(&napi->napi_hash_node);
5639         }
5640         spin_unlock(&napi_hash_lock);
5641         return rcu_sync_needed;
5642 }
5643 EXPORT_SYMBOL_GPL(napi_hash_del);
5644 
5645 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
5646 {
5647         struct napi_struct *napi;
5648 
5649         napi = container_of(timer, struct napi_struct, timer);
5650 
5651         /* Note : we use a relaxed variant of napi_schedule_prep() not setting
5652          * NAPI_STATE_MISSED, since we do not react to a device IRQ.
5653          */
5654         if (napi->gro_list && !napi_disable_pending(napi) &&
5655             !test_and_set_bit(NAPI_STATE_SCHED, &napi->state))
5656                 __napi_schedule_irqoff(napi);
5657 
5658         return HRTIMER_NORESTART;
5659 }
5660 
5661 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
5662                     int (*poll)(struct napi_struct *, int), int weight)
5663 {
5664         INIT_LIST_HEAD(&napi->poll_list);
5665         hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
5666         napi->timer.function = napi_watchdog;
5667         napi->gro_count = 0;
5668         napi->gro_list = NULL;
5669         napi->skb = NULL;
5670         napi->poll = poll;
5671         if (weight > NAPI_POLL_WEIGHT)
5672                 pr_err_once("netif_napi_add() called with weight %d on device %s\n",
5673                             weight, dev->name);
5674         napi->weight = weight;
5675         list_add(&napi->dev_list, &dev->napi_list);
5676         napi->dev = dev;
5677 #ifdef CONFIG_NETPOLL
5678         napi->poll_owner = -1;
5679 #endif
5680         set_bit(NAPI_STATE_SCHED, &napi->state);
5681         napi_hash_add(napi);
5682 }
5683 EXPORT_SYMBOL(netif_napi_add);
5684 
5685 void napi_disable(struct napi_struct *n)
5686 {
5687         might_sleep();
5688         set_bit(NAPI_STATE_DISABLE, &n->state);
5689 
5690         while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
5691                 msleep(1);
5692         while (test_and_set_bit(NAPI_STATE_NPSVC, &n->state))
5693                 msleep(1);
5694 
5695         hrtimer_cancel(&n->timer);
5696 
5697         clear_bit(NAPI_STATE_DISABLE, &n->state);
5698 }
5699 EXPORT_SYMBOL(napi_disable);
5700 
5701 /* Must be called in process context */
5702 void netif_napi_del(struct napi_struct *napi)
5703 {
5704         might_sleep();
5705         if (napi_hash_del(napi))
5706                 synchronize_net();
5707         list_del_init(&napi->dev_list);
5708         napi_free_frags(napi);
5709 
5710         kfree_skb_list(napi->gro_list);
5711         napi->gro_list = NULL;
5712         napi->gro_count = 0;
5713 }
5714 EXPORT_SYMBOL(netif_napi_del);
5715 
5716 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
5717 {
5718         void *have;
5719         int work, weight;
5720 
5721         list_del_init(&n->poll_list);
5722 
5723         have = netpoll_poll_lock(n);
5724 
5725         weight = n->weight;
5726 
5727         /* This NAPI_STATE_SCHED test is for avoiding a race
5728          * with netpoll's poll_napi().  Only the entity which
5729          * obtains the lock and sees NAPI_STATE_SCHED set will
5730          * actually make the ->poll() call.  Therefore we avoid
5731          * accidentally calling ->poll() when NAPI is not scheduled.
5732          */
5733         work = 0;
5734         if (test_bit(NAPI_STATE_SCHED, &n->state)) {
5735                 work = n->poll(n, weight);
5736                 trace_napi_poll(n, work, weight);
5737         }
5738 
5739         WARN_ON_ONCE(work > weight);
5740 
5741         if (likely(work < weight))
5742                 goto out_unlock;
5743 
5744         /* Drivers must not modify the NAPI state if they
5745          * consume the entire weight.  In such cases this code
5746          * still "owns" the NAPI instance and therefore can
5747          * move the instance around on the list at-will.
5748          */
5749         if (unlikely(napi_disable_pending(n))) {
5750                 napi_complete(n);
5751                 goto out_unlock;
5752         }
5753 
5754         if (n->gro_list) {
5755                 /* flush too old packets
5756                  * If HZ < 1000, flush all packets.
5757                  */
5758                 napi_gro_flush(n, HZ >= 1000);
5759         }
5760 
5761         /* Some drivers may have called napi_schedule
5762          * prior to exhausting their budget.
5763          */
5764         if (unlikely(!list_empty(&n->poll_list))) {
5765                 pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
5766                              n->dev ? n->dev->name : "backlog");
5767                 goto out_unlock;
5768         }
5769 
5770         list_add_tail(&n->poll_list, repoll);
5771 
5772 out_unlock:
5773         netpoll_poll_unlock(have);
5774 
5775         return work;
5776 }
5777 
5778 static __latent_entropy void net_rx_action(struct softirq_action *h)
5779 {
5780         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5781         unsigned long time_limit = jiffies +
5782                 usecs_to_jiffies(netdev_budget_usecs);
5783         int budget = netdev_budget;
5784         LIST_HEAD(list);
5785         LIST_HEAD(repoll);
5786 
5787         local_irq_disable();
5788         list_splice_init(&sd->poll_list, &list);
5789         local_irq_enable();
5790 
5791         for (;;) {
5792                 struct napi_struct *n;
5793 
5794                 if (list_empty(&list)) {
5795                         if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
5796                                 goto out;
5797                         break;
5798                 }
5799 
5800                 n = list_first_entry(&list, struct napi_struct, poll_list);
5801                 budget -= napi_poll(n, &repoll);
5802 
5803                 /* If softirq window is exhausted then punt.
5804                  * Allow this to run for 2 jiffies since which will allow
5805                  * an average latency of 1.5/HZ.
5806                  */
5807                 if (unlikely(budget <= 0 ||
5808                              time_after_eq(jiffies, time_limit))) {
5809                         sd->time_squeeze++;
5810                         break;
5811                 }
5812         }
5813 
5814         local_irq_disable();
5815 
5816         list_splice_tail_init(&sd->poll_list, &list);
5817         list_splice_tail(&repoll, &list);
5818         list_splice(&list, &sd->poll_list);
5819         if (!list_empty(&sd->poll_list))
5820                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
5821 
5822         net_rps_action_and_irq_enable(sd);
5823 out:
5824         __kfree_skb_flush();
5825 }
5826 
5827 struct netdev_adjacent {
5828         struct net_device *dev;
5829 
5830         /* upper master flag, there can only be one master device per list */
5831         bool master;
5832 
5833         /* counter for the number of times this device was added to us */
5834         u16 ref_nr;
5835 
5836         /* private field for the users */
5837         void *private;
5838 
5839         struct list_head list;
5840         struct rcu_head rcu;
5841 };
5842 
5843 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
5844                                                  struct list_head *adj_list)
5845 {
5846         struct netdev_adjacent *adj;
5847 
5848         list_for_each_entry(adj, adj_list, list) {
5849                 if (adj->dev == adj_dev)
5850                         return adj;
5851         }
5852         return NULL;
5853 }
5854 
5855 static int __netdev_has_upper_dev(struct net_device *upper_dev, void *data)
5856 {
5857         struct net_device *dev = data;
5858 
5859         return upper_dev == dev;
5860 }
5861 
5862 /**
5863  * netdev_has_upper_dev - Check if device is linked to an upper device
5864  * @dev: device
5865  * @upper_dev: upper device to check
5866  *
5867  * Find out if a device is linked to specified upper device and return true
5868  * in case it is. Note that this checks only immediate upper device,
5869  * not through a complete stack of devices. The caller must hold the RTNL lock.
5870  */
5871 bool netdev_has_upper_dev(struct net_device *dev,
5872                           struct net_device *upper_dev)
5873 {
5874         ASSERT_RTNL();
5875 
5876         return netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev,
5877                                              upper_dev);
5878 }
5879 EXPORT_SYMBOL(netdev_has_upper_dev);
5880 
5881 /**
5882  * netdev_has_upper_dev_all - Check if device is linked to an upper device
5883  * @dev: device
5884  * @upper_dev: upper device to check
5885  *
5886  * Find out if a device is linked to specified upper device and return true
5887  * in case it is. Note that this checks the entire upper device chain.
5888  * The caller must hold rcu lock.
5889  */
5890 
5891 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
5892                                   struct net_device *upper_dev)
5893 {
5894         return !!netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev,
5895                                                upper_dev);
5896 }
5897 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
5898 
5899 /**
5900  * netdev_has_any_upper_dev - Check if device is linked to some device
5901  * @dev: device
5902  *
5903  * Find out if a device is linked to an upper device and return true in case
5904  * it is. The caller must hold the RTNL lock.
5905  */
5906 bool netdev_has_any_upper_dev(struct net_device *dev)
5907 {
5908         ASSERT_RTNL();
5909 
5910         return !list_empty(&dev->adj_list.upper);
5911 }
5912 EXPORT_SYMBOL(netdev_has_any_upper_dev);
5913 
5914 /**
5915  * netdev_master_upper_dev_get - Get master upper device
5916  * @dev: device
5917  *
5918  * Find a master upper device and return pointer to it or NULL in case
5919  * it's not there. The caller must hold the RTNL lock.
5920  */
5921 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
5922 {
5923         struct netdev_adjacent *upper;
5924 
5925         ASSERT_RTNL();
5926 
5927         if (list_empty(&dev->adj_list.upper))
5928                 return NULL;
5929 
5930         upper = list_first_entry(&dev->adj_list.upper,
5931                                  struct netdev_adjacent, list);
5932         if (likely(upper->master))
5933                 return upper->dev;
5934         return NULL;
5935 }
5936 EXPORT_SYMBOL(netdev_master_upper_dev_get);
5937 
5938 /**
5939  * netdev_has_any_lower_dev - Check if device is linked to some device
5940  * @dev: device
5941  *
5942  * Find out if a device is linked to a lower device and return true in case
5943  * it is. The caller must hold the RTNL lock.
5944  */
5945 static bool netdev_has_any_lower_dev(struct net_device *dev)
5946 {
5947         ASSERT_RTNL();
5948 
5949         return !list_empty(&dev->adj_list.lower);
5950 }
5951 
5952 void *netdev_adjacent_get_private(struct list_head *adj_list)
5953 {
5954         struct netdev_adjacent *adj;
5955 
5956         adj = list_entry(adj_list, struct netdev_adjacent, list);
5957 
5958         return adj->private;
5959 }
5960 EXPORT_SYMBOL(netdev_adjacent_get_private);
5961 
5962 /**
5963  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
5964  * @dev: device
5965  * @iter: list_head ** of the current position
5966  *
5967  * Gets the next device from the dev's upper list, starting from iter
5968  * position. The caller must hold RCU read lock.
5969  */
5970 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
5971                                                  struct list_head **iter)
5972 {
5973         struct netdev_adjacent *upper;
5974 
5975         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
5976 
5977         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
5978 
5979         if (&upper->list == &dev->adj_list.upper)
5980                 return NULL;
5981 
5982         *iter = &upper->list;
5983 
5984         return upper->dev;
5985 }
5986 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
5987 
5988 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
5989                                                     struct list_head **iter)
5990 {
5991         struct netdev_adjacent *upper;
5992 
5993         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
5994 
5995         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
5996 
5997         if (&upper->list == &dev->adj_list.upper)
5998                 return NULL;
5999 
6000         *iter = &upper->list;
6001 
6002         return upper->dev;
6003 }
6004 
6005 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6006                                   int (*fn)(struct net_device *dev,
6007                                             void *data),
6008                                   void *data)
6009 {
6010         struct net_device *udev;
6011         struct list_head *iter;
6012         int ret;
6013 
6014         for (iter = &dev->adj_list.upper,
6015              udev = netdev_next_upper_dev_rcu(dev, &iter);
6016              udev;
6017              udev = netdev_next_upper_dev_rcu(dev, &iter)) {
6018                 /* first is the upper device itself */
6019                 ret = fn(udev, data);
6020                 if (ret)
6021                         return ret;
6022 
6023                 /* then look at all of its upper devices */
6024                 ret = netdev_walk_all_upper_dev_rcu(udev, fn, data);
6025                 if (ret)
6026                         return ret;
6027         }
6028 
6029         return 0;
6030 }
6031 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
6032 
6033 /**
6034  * netdev_lower_get_next_private - Get the next ->private from the
6035  *                                 lower neighbour list
6036  * @dev: device
6037  * @iter: list_head ** of the current position
6038  *
6039  * Gets the next netdev_adjacent->private from the dev's lower neighbour
6040  * list, starting from iter position. The caller must hold either hold the
6041  * RTNL lock or its own locking that guarantees that the neighbour lower
6042  * list will remain unchanged.
6043  */
6044 void *netdev_lower_get_next_private(struct net_device *dev,
6045                                     struct list_head **iter)
6046 {
6047         struct netdev_adjacent *lower;
6048 
6049         lower = list_entry(*iter, struct netdev_adjacent, list);
6050 
6051         if (&lower->list == &dev->adj_list.lower)
6052                 return NULL;
6053 
6054         *iter = lower->list.next;
6055 
6056         return lower->private;
6057 }
6058 EXPORT_SYMBOL(netdev_lower_get_next_private);
6059 
6060 /**
6061  * netdev_lower_get_next_private_rcu - Get the next ->private from the
6062  *                                     lower neighbour list, RCU
6063  *                                     variant
6064  * @dev: device
6065  * @iter: list_head ** of the current position
6066  *
6067  * Gets the next netdev_adjacent->private from the dev's lower neighbour
6068  * list, starting from iter position. The caller must hold RCU read lock.
6069  */
6070 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
6071                                         struct list_head **iter)
6072 {
6073         struct netdev_adjacent *lower;
6074 
6075         WARN_ON_ONCE(!rcu_read_lock_held());
6076 
6077         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6078 
6079         if (&lower->list == &dev->adj_list.lower)
6080                 return NULL;
6081 
6082         *iter = &lower->list;
6083 
6084         return lower->private;
6085 }
6086 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
6087 
6088 /**
6089  * netdev_lower_get_next - Get the next device from the lower neighbour
6090  *                         list
6091  * @dev: device
6092  * @iter: list_head ** of the current position
6093  *
6094  * Gets the next netdev_adjacent from the dev's lower neighbour
6095  * list, starting from iter position. The caller must hold RTNL lock or
6096  * its own locking that guarantees that the neighbour lower
6097  * list will remain unchanged.
6098  */
6099 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
6100 {
6101         struct netdev_adjacent *lower;
6102 
6103         lower = list_entry(*iter, struct netdev_adjacent, list);
6104 
6105         if (&lower->list == &dev->adj_list.lower)
6106                 return NULL;
6107 
6108         *iter = lower->list.next;
6109 
6110         return lower->dev;
6111 }
6112 EXPORT_SYMBOL(netdev_lower_get_next);
6113 
6114 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
6115                                                 struct list_head **iter)
6116 {
6117         struct netdev_adjacent *lower;
6118 
6119         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
6120 
6121         if (&lower->list == &dev->adj_list.lower)
6122                 return NULL;
6123 
6124         *iter = &lower->list;
6125 
6126         return lower->dev;
6127 }
6128 
6129 int netdev_walk_all_lower_dev(struct net_device *dev,
6130                               int (*fn)(struct net_device *dev,
6131                                         void *data),
6132                               void *data)
6133 {
6134         struct net_device *ldev;
6135         struct list_head *iter;
6136         int ret;
6137 
6138         for (iter = &dev->adj_list.lower,
6139              ldev = netdev_next_lower_dev(dev, &iter);
6140              ldev;
6141              ldev = netdev_next_lower_dev(dev, &iter)) {
6142                 /* first is the lower device itself */
6143                 ret = fn(ldev, data);
6144                 if (ret)
6145                         return ret;
6146 
6147                 /* then look at all of its lower devices */
6148                 ret = netdev_walk_all_lower_dev(ldev, fn, data);
6149                 if (ret)
6150                         return ret;
6151         }
6152 
6153         return 0;
6154 }
6155 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
6156 
6157 static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
6158                                                     struct list_head **iter)
6159 {
6160         struct netdev_adjacent *lower;
6161 
6162         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6163         if (&lower->list == &dev->adj_list.lower)
6164                 return NULL;
6165 
6166         *iter = &lower->list;
6167 
6168         return lower->dev;
6169 }
6170 
6171 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
6172                                   int (*fn)(struct net_device *dev,
6173                                             void *data),
6174                                   void *data)
6175 {
6176         struct net_device *ldev;
6177         struct list_head *iter;
6178         int ret;
6179 
6180         for (iter = &dev->adj_list.lower,
6181              ldev = netdev_next_lower_dev_rcu(dev, &iter);
6182              ldev;
6183              ldev = netdev_next_lower_dev_rcu(dev, &iter)) {
6184                 /* first is the lower device itself */
6185                 ret = fn(ldev, data);
6186                 if (ret)
6187                         return ret;
6188 
6189                 /* then look at all of its lower devices */
6190                 ret = netdev_walk_all_lower_dev_rcu(ldev, fn, data);
6191                 if (ret)
6192                         return ret;
6193         }
6194 
6195         return 0;
6196 }
6197 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
6198 
6199 /**
6200  * netdev_lower_get_first_private_rcu - Get the first ->private from the
6201  *                                     lower neighbour list, RCU
6202  *                                     variant
6203  * @dev: device
6204  *
6205  * Gets the first netdev_adjacent->private from the dev's lower neighbour
6206  * list. The caller must hold RCU read lock.
6207  */
6208 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
6209 {
6210         struct netdev_adjacent *lower;
6211 
6212         lower = list_first_or_null_rcu(&dev->adj_list.lower,
6213                         struct netdev_adjacent, list);
6214         if (lower)
6215                 return lower->private;
6216         return NULL;
6217 }
6218 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
6219 
6220 /**
6221  * netdev_master_upper_dev_get_rcu - Get master upper device
6222  * @dev: device
6223  *
6224  * Find a master upper device and return pointer to it or NULL in case
6225  * it's not there. The caller must hold the RCU read lock.
6226  */
6227 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
6228 {
6229         struct netdev_adjacent *upper;
6230 
6231         upper = list_first_or_null_rcu(&dev->adj_list.upper,
6232                                        struct netdev_adjacent, list);
6233         if (upper && likely(upper->master))
6234                 return upper->dev;
6235         return NULL;
6236 }
6237 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
6238 
6239 static int netdev_adjacent_sysfs_add(struct net_device *dev,
6240                               struct net_device *adj_dev,
6241                               struct list_head *dev_list)
6242 {
6243         char linkname[IFNAMSIZ+7];
6244 
6245         sprintf(linkname, dev_list == &dev->adj_list.upper ?
6246                 "upper_%s" : "lower_%s", adj_dev->name);
6247         return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
6248                                  linkname);
6249 }
6250 static void netdev_adjacent_sysfs_del(struct net_device *dev,
6251                                char *name,
6252                                struct list_head *dev_list)
6253 {
6254         char linkname[IFNAMSIZ+7];
6255 
6256         sprintf(linkname, dev_list == &dev->adj_list.upper ?
6257                 "upper_%s" : "lower_%s", name);
6258         sysfs_remove_link(&(dev->dev.kobj), linkname);
6259 }
6260 
6261 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
6262                                                  struct net_device *adj_dev,
6263                                                  struct list_head *dev_list)
6264 {
6265         return (dev_list == &dev->adj_list.upper ||
6266                 dev_list == &dev->adj_list.lower) &&
6267                 net_eq(dev_net(dev), dev_net(adj_dev));
6268 }
6269 
6270 static int __netdev_adjacent_dev_insert(struct net_device *dev,
6271                                         struct net_device *adj_dev,
6272                                         struct list_head *dev_list,
6273                                         void *private, bool master)
6274 {
6275         struct netdev_adjacent *adj;
6276         int ret;
6277 
6278         adj = __netdev_find_adj(adj_dev, dev_list);
6279 
6280         if (adj) {
6281                 adj->ref_nr += 1;
6282                 pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
6283                          dev->name, adj_dev->name, adj->ref_nr);
6284 
6285                 return 0;
6286         }
6287 
6288         adj = kmalloc(sizeof(*adj), GFP_KERNEL);
6289         if (!adj)
6290                 return -ENOMEM;
6291 
6292         adj->dev = adj_dev;
6293         adj->master = master;
6294         adj->ref_nr = 1;
6295         adj->private = private;
6296         dev_hold(adj_dev);
6297 
6298         pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
6299                  dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
6300 
6301         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
6302                 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
6303                 if (ret)
6304                         goto free_adj;
6305         }
6306 
6307         /* Ensure that master link is always the first item in list. */
6308         if (master) {
6309                 ret = sysfs_create_link(&(dev->dev.kobj),
6310                                         &(adj_dev->dev.kobj), "master");
6311                 if (ret)
6312                         goto remove_symlinks;
6313 
6314                 list_add_rcu(&adj->list, dev_list);
6315         } else {
6316                 list_add_tail_rcu(&adj->list, dev_list);
6317         }
6318 
6319         return 0;
6320 
6321 remove_symlinks:
6322         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
6323                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
6324 free_adj:
6325         kfree(adj);
6326         dev_put(adj_dev);
6327 
6328         return ret;
6329 }
6330 
6331 static void __netdev_adjacent_dev_remove(struct net_device *dev,
6332                                          struct net_device *adj_dev,
6333                                          u16 ref_nr,
6334                                          struct list_head *dev_list)
6335 {
6336         struct netdev_adjacent *adj;
6337 
6338         pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
6339                  dev->name, adj_dev->name, ref_nr);
6340 
6341         adj = __netdev_find_adj(adj_dev, dev_list);
6342 
6343         if (!adj) {
6344                 pr_err("Adjacency does not exist for device %s from %s\n",
6345                        dev->name, adj_dev->name);
6346                 WARN_ON(1);
6347                 return;
6348         }
6349 
6350         if (adj->ref_nr > ref_nr) {
6351                 pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
6352                          dev->name, adj_dev->name, ref_nr,
6353                          adj->ref_nr - ref_nr);
6354                 adj->ref_nr -= ref_nr;
6355                 return;
6356         }
6357 
6358         if (adj->master)
6359                 sysfs_remove_link(&(dev->dev.kobj), "master");
6360 
6361         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
6362                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
6363 
6364         list_del_rcu(&adj->list);
6365         pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
6366                  adj_dev->name, dev->name, adj_dev->name);
6367         dev_put(adj_dev);
6368         kfree_rcu(adj, rcu);
6369 }
6370 
6371 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
6372                                             struct net_device *upper_dev,
6373                                             struct list_head *up_list,
6374                                             struct list_head *down_list,
6375                                             void *private, bool master)
6376 {
6377         int ret;
6378 
6379         ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
6380                                            private, master);
6381         if (ret)
6382                 return ret;
6383 
6384         ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
6385                                            private, false);
6386         if (ret) {
6387                 __netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
6388                 return ret;
6389         }
6390 
6391         return 0;
6392 }
6393 
6394 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
6395                                                struct net_device *upper_dev,
6396                                                u16 ref_nr,
6397                                                struct list_head *up_list,
6398                                                struct list_head *down_list)
6399 {
6400         __netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
6401         __netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
6402 }
6403 
6404 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
6405                                                 struct net_device *upper_dev,
6406                                                 void *private, bool master)
6407 {
6408         return __netdev_adjacent_dev_link_lists(dev, upper_dev,
6409                                                 &dev->adj_list.upper,
6410                                                 &upper_dev->adj_list.lower,
6411                                                 private, master);
6412 }
6413 
6414 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
6415                                                    struct net_device *upper_dev)
6416 {
6417         __netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
6418                                            &dev->adj_list.upper,
6419                                            &upper_dev->adj_list.lower);
6420 }
6421 
6422 static int __netdev_upper_dev_link(struct net_device *dev,
6423                                    struct net_device *upper_dev, bool master,
6424                                    void *upper_priv, void *upper_info,
6425                                    struct netlink_ext_ack *extack)
6426 {
6427         struct netdev_notifier_changeupper_info changeupper_info = {
6428                 .info = {
6429                         .dev = dev,
6430                         .extack = extack,
6431                 },
6432                 .upper_dev = upper_dev,
6433                 .master = master,
6434                 .linking = true,
6435                 .upper_info = upper_info,
6436         };
6437         struct net_device *master_dev;
6438         int ret = 0;
6439 
6440         ASSERT_RTNL();
6441 
6442         if (dev == upper_dev)
6443                 return -EBUSY;
6444 
6445         /* To prevent loops, check if dev is not upper device to upper_dev. */
6446         if (netdev_has_upper_dev(upper_dev, dev))
6447                 return -EBUSY;
6448 
6449         if (!master) {
6450                 if (netdev_has_upper_dev(dev, upper_dev))
6451                         return -EEXIST;
6452         } else {
6453                 master_dev = netdev_master_upper_dev_get(dev);
6454                 if (master_dev)
6455                         return master_dev == upper_dev ? -EEXIST : -EBUSY;
6456         }
6457 
6458         ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
6459                                             &changeupper_info.info);
6460         ret = notifier_to_errno(ret);
6461         if (ret)
6462                 return ret;
6463 
6464         ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
6465                                                    master);
6466         if (ret)
6467                 return ret;
6468 
6469         ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
6470                                             &changeupper_info.info);
6471         ret = notifier_to_errno(ret);
6472         if (ret)
6473                 goto rollback;
6474 
6475         return 0;
6476 
6477 rollback:
6478         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
6479 
6480         return ret;
6481 }
6482 
6483 /**
6484  * netdev_upper_dev_link - Add a link to the upper device
6485  * @dev: device
6486  * @upper_dev: new upper device
6487  * @extack: netlink extended ack
6488  *
6489  * Adds a link to device which is upper to this one. The caller must hold
6490  * the RTNL lock. On a failure a negative errno code is returned.
6491  * On success the reference counts are adjusted and the function
6492  * returns zero.
6493  */
6494 int netdev_upper_dev_link(struct net_device *dev,
6495                           struct net_device *upper_dev,
6496                           struct netlink_ext_ack *extack)
6497 {
6498         return __netdev_upper_dev_link(dev, upper_dev, false,
6499                                        NULL, NULL, extack);
6500 }
6501 EXPORT_SYMBOL(netdev_upper_dev_link);
6502 
6503 /**
6504  * netdev_master_upper_dev_link - Add a master link to the upper device
6505  * @dev: device
6506  * @upper_dev: new upper device
6507  * @upper_priv: upper device private
6508  * @upper_info: upper info to be passed down via notifier
6509  * @extack: netlink extended ack
6510  *
6511  * Adds a link to device which is upper to this one. In this case, only
6512  * one master upper device can be linked, although other non-master devices
6513  * might be linked as well. The caller must hold the RTNL lock.
6514  * On a failure a negative errno code is returned. On success the reference
6515  * counts are adjusted and the function returns zero.
6516  */
6517 int netdev_master_upper_dev_link(struct net_device *dev,
6518                                  struct net_device *upper_dev,
6519                                  void *upper_priv, void *upper_info,
6520                                  struct netlink_ext_ack *extack)
6521 {
6522         return __netdev_upper_dev_link(dev, upper_dev, true,
6523                                        upper_priv, upper_info, extack);
6524 }
6525 EXPORT_SYMBOL(netdev_master_upper_dev_link);
6526 
6527 /**
6528  * netdev_upper_dev_unlink - Removes a link to upper device
6529  * @dev: device
6530  * @upper_dev: new upper device
6531  *
6532  * Removes a link to device which is upper to this one. The caller must hold
6533  * the RTNL lock.
6534  */
6535 void netdev_upper_dev_unlink(struct net_device *dev,
6536                              struct net_device *upper_dev)
6537 {
6538         struct netdev_notifier_changeupper_info changeupper_info = {
6539                 .info = {
6540                         .dev = dev,
6541                 },
6542                 .upper_dev = upper_dev,
6543                 .linking = false,
6544         };
6545 
6546         ASSERT_RTNL();
6547 
6548         changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
6549 
6550         call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
6551                                       &changeupper_info.info);
6552 
6553         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
6554 
6555         call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
6556                                       &changeupper_info.info);
6557 }
6558 EXPORT_SYMBOL(netdev_upper_dev_unlink);
6559 
6560 /**
6561  * netdev_bonding_info_change - Dispatch event about slave change
6562  * @dev: device
6563  * @bonding_info: info to dispatch
6564  *
6565  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
6566  * The caller must hold the RTNL lock.
6567  */
6568 void netdev_bonding_info_change(struct net_device *dev,
6569                                 struct netdev_bonding_info *bonding_info)
6570 {
6571         struct netdev_notifier_bonding_info info = {
6572                 .info.dev = dev,
6573         };
6574 
6575         memcpy(&info.bonding_info, bonding_info,
6576                sizeof(struct netdev_bonding_info));
6577         call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
6578                                       &info.info);
6579 }
6580 EXPORT_SYMBOL(netdev_bonding_info_change);
6581 
6582 static void netdev_adjacent_add_links(struct net_device *dev)
6583 {
6584         struct netdev_adjacent *iter;
6585 
6586         struct net *net = dev_net(dev);
6587 
6588         list_for_each_entry(iter, &dev->adj_list.upper, list) {
6589                 if (!net_eq(net, dev_net(iter->dev)))
6590                         continue;
6591                 netdev_adjacent_sysfs_add(iter->dev, dev,
6592                                           &iter->dev->adj_list.lower);
6593                 netdev_adjacent_sysfs_add(dev, iter->dev,
6594                                           &dev->adj_list.upper);
6595         }
6596 
6597         list_for_each_entry(iter, &dev->adj_list.lower, list) {
6598                 if (!net_eq(net, dev_net(iter->dev)))
6599                         continue;
6600                 netdev_adjacent_sysfs_add(iter->dev, dev,
6601                                           &iter->dev->adj_list.upper);
6602                 netdev_adjacent_sysfs_add(dev, iter->dev,
6603                                           &dev->adj_list.lower);
6604         }
6605 }
6606 
6607 static void netdev_adjacent_del_links(struct net_device *dev)
6608 {
6609         struct netdev_adjacent *iter;
6610 
6611         struct net *net = dev_net(dev);
6612 
6613         list_for_each_entry(iter, &dev->adj_list.upper, list) {
6614                 if (!net_eq(net, dev_net(iter->dev)))
6615                         continue;
6616                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
6617                                           &iter->dev->adj_list.lower);
6618                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
6619                                           &dev->adj_list.upper);
6620         }
6621 
6622         list_for_each_entry(iter, &dev->adj_list.lower, list) {
6623                 if (!net_eq(net, dev_net(iter->dev)))
6624                         continue;
6625                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
6626                                           &iter->dev->adj_list.upper);
6627                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
6628                                           &dev->adj_list.lower);
6629         }
6630 }
6631 
6632 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
6633 {
6634         struct netdev_adjacent *iter;
6635 
6636         struct net *net = dev_net(dev);
6637 
6638         list_for_each_entry(iter, &dev->adj_list.upper, list) {
6639                 if (!net_eq(net, dev_net(iter->dev)))
6640                         continue;
6641                 netdev_adjacent_sysfs_del(iter->dev, oldname,
6642                                           &iter->dev->adj_list.lower);
6643                 netdev_adjacent_sysfs_add(iter->dev, dev,
6644                                           &iter->dev->adj_list.lower);
6645         }
6646 
6647         list_for_each_entry(iter, &dev->adj_list.lower, list) {
6648                 if (!net_eq(net, dev_net(iter->dev)))
6649                         continue;
6650                 netdev_adjacent_sysfs_del(iter->dev, oldname,
6651                                           &iter->dev->adj_list.upper);
6652                 netdev_adjacent_sysfs_add(iter->dev, dev,
6653                                           &iter->dev->adj_list.upper);
6654         }
6655 }
6656 
6657 void *netdev_lower_dev_get_private(struct net_device *dev,
6658                                    struct net_device *lower_dev)
6659 {
6660         struct netdev_adjacent *lower;
6661 
6662         if (!lower_dev)
6663                 return NULL;
6664         lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
6665         if (!lower)
6666                 return NULL;
6667 
6668         return lower->private;
6669 }
6670 EXPORT_SYMBOL(netdev_lower_dev_get_private);
6671 
6672 
6673 int dev_get_nest_level(struct net_device *dev)
6674 {
6675         struct net_device *lower = NULL;
6676         struct list_head *iter;
6677         int max_nest = -1;
6678         int nest;
6679 
6680         ASSERT_RTNL();
6681 
6682         netdev_for_each_lower_dev(dev, lower, iter) {
6683                 nest = dev_get_nest_level(lower);
6684                 if (max_nest < nest)
6685                         max_nest = nest;
6686         }
6687 
6688         return max_nest + 1;
6689 }
6690 EXPORT_SYMBOL(dev_get_nest_level);
6691 
6692 /**
6693  * netdev_lower_change - Dispatch event about lower device state change
6694  * @lower_dev: device
6695  * @lower_state_info: state to dispatch
6696  *
6697  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
6698  * The caller must hold the RTNL lock.
6699  */
6700 void netdev_lower_state_changed(struct net_device *lower_dev,
6701                                 void *lower_state_info)
6702 {
6703         struct netdev_notifier_changelowerstate_info changelowerstate_info = {
6704                 .info.dev = lower_dev,
6705         };
6706 
6707         ASSERT_RTNL();
6708         changelowerstate_info.lower_state_info = lower_state_info;
6709         call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
6710                                       &changelowerstate_info.info);
6711 }
6712 EXPORT_SYMBOL(netdev_lower_state_changed);
6713 
6714 static void dev_change_rx_flags(struct net_device *dev, int flags)
6715 {
6716         const struct net_device_ops *ops = dev->netdev_ops;
6717 
6718         if (ops->ndo_change_rx_flags)
6719                 ops->ndo_change_rx_flags(dev, flags);
6720 }
6721 
6722 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
6723 {
6724         unsigned int old_flags = dev->flags;
6725         kuid_t uid;
6726         kgid_t gid;
6727 
6728         ASSERT_RTNL();
6729 
6730         dev->flags |= IFF_PROMISC;
6731         dev->promiscuity += inc;
6732         if (dev->promiscuity == 0) {
6733                 /*
6734                  * Avoid overflow.
6735                  * If inc causes overflow, untouch promisc and return error.
6736                  */
6737                 if (inc < 0)
6738                         dev->flags &= ~IFF_PROMISC;
6739                 else {
6740                         dev->promiscuity -= inc;
6741                         pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
6742                                 dev->name);
6743                         return -EOVERFLOW;
6744                 }
6745         }
6746         if (dev->flags != old_flags) {
6747                 pr_info("device %s %s promiscuous mode\n",
6748                         dev->name,
6749                         dev->flags & IFF_PROMISC ? "entered" : "left");
6750                 if (audit_enabled) {
6751                         current_uid_gid(&uid, &gid);
6752                         audit_log(current->audit_context, GFP_ATOMIC,
6753                                 AUDIT_ANOM_PROMISCUOUS,
6754                                 "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
6755                                 dev->name, (dev->flags & IFF_PROMISC),
6756                                 (old_flags & IFF_PROMISC),
6757                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
6758                                 from_kuid(&init_user_ns, uid),
6759                                 from_kgid(&init_user_ns, gid),
6760                                 audit_get_sessionid(current));
6761                 }
6762 
6763                 dev_change_rx_flags(dev, IFF_PROMISC);
6764         }
6765         if (notify)
6766                 __dev_notify_flags(dev, old_flags, IFF_PROMISC);
6767         return 0;
6768 }
6769 
6770 /**
6771  *      dev_set_promiscuity     - update promiscuity count on a device
6772  *      @dev: device
6773  *      @inc: modifier
6774  *
6775  *      Add or remove promiscuity from a device. While the count in the device
6776  *      remains above zero the interface remains promiscuous. Once it hits zero
6777  *      the device reverts back to normal filtering operation. A negative inc
6778  *      value is used to drop promiscuity on the device.
6779  *      Return 0 if successful or a negative errno code on error.
6780  */
6781 int dev_set_promiscuity(struct net_device *dev, int inc)
6782 {
6783         unsigned int old_flags = dev->flags;
6784         int err;
6785 
6786         err = __dev_set_promiscuity(dev, inc, true);
6787         if (err < 0)
6788                 return err;
6789         if (dev->flags != old_flags)
6790                 dev_set_rx_mode(dev);
6791         return err;
6792 }
6793 EXPORT_SYMBOL(dev_set_promiscuity);
6794 
6795 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
6796 {
6797         unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
6798 
6799         ASSERT_RTNL();
6800 
6801         dev->flags |= IFF_ALLMULTI;
6802         dev->allmulti += inc;
6803         if (dev->allmulti == 0) {
6804                 /*
6805                  * Avoid overflow.
6806                  * If inc causes overflow, untouch allmulti and return error.
6807                  */
6808                 if (inc < 0)
6809                         dev->flags &= ~IFF_ALLMULTI;
6810                 else {
6811                         dev->allmulti -= inc;
6812                         pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
6813                                 dev->name);
6814                         return -EOVERFLOW;
6815                 }
6816         }
6817         if (dev->flags ^ old_flags) {
6818                 dev_change_rx_flags(dev, IFF_ALLMULTI);
6819                 dev_set_rx_mode(dev);
6820                 if (notify)
6821                         __dev_notify_flags(dev, old_flags,
6822                                            dev->gflags ^ old_gflags);
6823         }
6824         return 0;
6825 }
6826 
6827 /**
6828  *      dev_set_allmulti        - update allmulti count on a device
6829  *      @dev: device
6830  *      @inc: modifier
6831  *
6832  *      Add or remove reception of all multicast frames to a device. While the
6833  *      count in the device remains above zero the interface remains listening
6834  *      to all interfaces. Once it hits zero the device reverts back to normal
6835  *      filtering operation. A negative @inc value is used to drop the counter
6836  *      when releasing a resource needing all multicasts.
6837  *      Return 0 if successful or a negative errno code on error.
6838  */
6839 
6840 int dev_set_allmulti(struct net_device *dev, int inc)
6841 {
6842         return __dev_set_allmulti(dev, inc, true);
6843 }
6844 EXPORT_SYMBOL(dev_set_allmulti);
6845 
6846 /*
6847  *      Upload unicast and multicast address lists to device and
6848  *      configure RX filtering. When the device doesn't support unicast
6849  *      filtering it is put in promiscuous mode while unicast addresses
6850  *      are present.
6851  */
6852 void __dev_set_rx_mode(struct net_device *dev)
6853 {
6854         const struct net_device_ops *ops = dev->netdev_ops;
6855 
6856         /* dev_open will call this function so the list will stay sane. */
6857         if (!(dev->flags&IFF_UP))
6858                 return;
6859 
6860         if (!netif_device_present(dev))
6861                 return;
6862 
6863         if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
6864                 /* Unicast addresses changes may only happen under the rtnl,
6865                  * therefore calling __dev_set_promiscuity here is safe.
6866                  */
6867                 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
6868                         __dev_set_promiscuity(dev, 1, false);
6869                         dev->uc_promisc = true;
6870                 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
6871                         __dev_set_promiscuity(dev, -1, false);
6872                         dev->uc_promisc = false;
6873                 }
6874         }
6875 
6876         if (ops->ndo_set_rx_mode)
6877                 ops->ndo_set_rx_mode(dev);
6878 }
6879 
6880 void dev_set_rx_mode(struct net_device *dev)
6881 {
6882         netif_addr_lock_bh(dev);
6883         __dev_set_rx_mode(dev);
6884         netif_addr_unlock_bh(dev);
6885 }
6886 
6887 /**
6888  *      dev_get_flags - get flags reported to userspace
6889  *      @dev: device
6890  *
6891  *      Get the combination of flag bits exported through APIs to userspace.
6892  */
6893 unsigned int dev_get_flags(const struct net_device *dev)
6894 {
6895         unsigned int flags;
6896 
6897         flags = (dev->flags & ~(IFF_PROMISC |
6898                                 IFF_ALLMULTI |
6899                                 IFF_RUNNING |
6900                                 IFF_LOWER_UP |
6901                                 IFF_DORMANT)) |
6902                 (dev->gflags & (IFF_PROMISC |
6903                                 IFF_ALLMULTI));
6904 
6905         if (netif_running(dev)) {
6906                 if (netif_oper_up(dev))
6907                         flags |= IFF_RUNNING;
6908                 if (netif_carrier_ok(dev))
6909                         flags |= IFF_LOWER_UP;
6910                 if (netif_dormant(dev))
6911                         flags |= IFF_DORMANT;
6912         }
6913 
6914         return flags;
6915 }
6916 EXPORT_SYMBOL(dev_get_flags);
6917 
6918 int __dev_change_flags(struct net_device *dev, unsigned int flags)
6919 {
6920         unsigned int old_flags = dev->flags;
6921         int ret;
6922 
6923         ASSERT_RTNL();
6924 
6925         /*
6926          *      Set the flags on our device.
6927          */
6928 
6929         dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
6930                                IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
6931                                IFF_AUTOMEDIA)) |
6932                      (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
6933                                     IFF_ALLMULTI));
6934 
6935         /*
6936          *      Load in the correct multicast list now the flags have changed.
6937          */
6938 
6939         if ((old_flags ^ flags) & IFF_MULTICAST)
6940                 dev_change_rx_flags(dev, IFF_MULTICAST);
6941 
6942         dev_set_rx_mode(dev);
6943 
6944         /*
6945          *      Have we downed the interface. We handle IFF_UP ourselves
6946          *      according to user attempts to set it, rather than blindly
6947          *      setting it.
6948          */
6949 
6950         ret = 0;
6951         if ((old_flags ^ flags) & IFF_UP) {
6952                 if (old_flags & IFF_UP)
6953                         __dev_close(dev);
6954                 else
6955                         ret = __dev_open(dev);
6956         }
6957 
6958         if ((flags ^ dev->gflags) & IFF_PROMISC) {
6959                 int inc = (flags & IFF_PROMISC) ? 1 : -1;
6960                 unsigned int old_flags = dev->flags;
6961 
6962                 dev->gflags ^= IFF_PROMISC;
6963 
6964                 if (__dev_set_promiscuity(dev, inc, false) >= 0)
6965                         if (dev->flags != old_flags)
6966                                 dev_set_rx_mode(dev);
6967         }
6968 
6969         /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
6970          * is important. Some (broken) drivers set IFF_PROMISC, when
6971          * IFF_ALLMULTI is requested not asking us and not reporting.
6972          */
6973         if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
6974                 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
6975 
6976                 dev->gflags ^= IFF_ALLMULTI;
6977                 __dev_set_allmulti(dev, inc, false);
6978         }
6979 
6980         return ret;
6981 }
6982 
6983 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
6984                         unsigned int gchanges)
6985 {
6986         unsigned int changes = dev->flags ^ old_flags;
6987 
6988         if (gchanges)
6989                 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
6990 
6991         if (changes & IFF_UP) {
6992                 if (dev->flags & IFF_UP)
6993                         call_netdevice_notifiers(NETDEV_UP, dev);
6994                 else
6995                         call_netdevice_notifiers(NETDEV_DOWN, dev);
6996         }
6997 
6998         if (dev->flags & IFF_UP &&
6999             (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
7000                 struct netdev_notifier_change_info change_info = {
7001                         .info = {
7002                                 .dev = dev,
7003                         },
7004                         .flags_changed = changes,
7005                 };
7006 
7007                 call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
7008         }
7009 }
7010 
7011 /**
7012  *      dev_change_flags - change device settings
7013  *      @dev: device
7014  *      @flags: device state flags
7015  *
7016  *      Change settings on device based state flags. The flags are
7017  *      in the userspace exported format.
7018  */
7019 int dev_change_flags(struct net_device *dev, unsigned int flags)
7020 {
7021         int ret;
7022         unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
7023 
7024         ret = __dev_change_flags(dev, flags);
7025         if (ret < 0)
7026                 return ret;
7027 
7028         changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
7029         __dev_notify_flags(dev, old_flags, changes);
7030         return ret;
7031 }
7032 EXPORT_SYMBOL(dev_change_flags);
7033 
7034 int __dev_set_mtu(struct net_device *dev, int new_mtu)
7035 {
7036         const struct net_device_ops *ops = dev->netdev_ops;
7037 
7038         if (ops->ndo_change_mtu)
7039                 return ops->ndo_change_mtu(dev, new_mtu);
7040 
7041         dev->mtu = new_mtu;
7042         return 0;
7043 }
7044 EXPORT_SYMBOL(__dev_set_mtu);
7045 
7046 /**
7047  *      dev_set_mtu - Change maximum transfer unit
7048  *      @dev: device
7049  *      @new_mtu: new transfer unit
7050  *
7051  *      Change the maximum transfer size of the network device.
7052  */
7053 int dev_set_mtu(struct net_device *dev, int new_mtu)
7054 {
7055         int err, orig_mtu;
7056 
7057         if (new_mtu == dev->mtu)
7058                 return 0;
7059 
7060         /* MTU must be positive, and in range */
7061         if (new_mtu < 0 || new_mtu < dev->min_mtu) {
7062                 net_err_ratelimited("%s: Invalid MTU %d requested, hw min %d\n",
7063                                     dev->name, new_mtu, dev->min_mtu);
7064                 return -EINVAL;
7065         }
7066 
7067         if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
7068                 net_err_ratelimited("%s: Invalid MTU %d requested, hw max %d\n",
7069                                     dev->name, new_mtu, dev->max_mtu);
7070                 return -EINVAL;
7071         }
7072 
7073         if (!netif_device_present(dev))
7074                 return -ENODEV;
7075 
7076         err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
7077         err = notifier_to_errno(err);
7078         if (err)
7079                 return err;
7080 
7081         orig_mtu = dev->mtu;
7082         err = __dev_set_mtu(dev, new_mtu);
7083 
7084         if (!err) {
7085                 err = call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
7086                 err = notifier_to_errno(err);
7087                 if (err) {
7088                         /* setting mtu back and notifying everyone again,
7089                          * so that they have a chance to revert changes.
7090                          */
7091                         __dev_set_mtu(dev, orig_mtu);
7092                         call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
7093                 }
7094         }
7095         return err;
7096 }
7097 EXPORT_SYMBOL(dev_set_mtu);
7098 
7099 /**
7100  *      dev_change_tx_queue_len - Change TX queue length of a netdevice
7101  *      @dev: device
7102  *      @new_len: new tx queue length
7103  */
7104 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
7105 {
7106         unsigned int orig_len = dev->tx_queue_len;
7107         int res;
7108 
7109         if (new_len != (unsigned int)new_len)
7110                 return -ERANGE;
7111 
7112         if (new_len != orig_len) {
7113                 dev->tx_queue_len = new_len;
7114                 res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
7115                 res = notifier_to_errno(res);
7116                 if (res) {
7117                         netdev_err(dev,
7118                                    "refused to change device tx_queue_len\n");
7119                         dev->tx_queue_len = orig_len;
7120                         return res;
7121                 }
7122                 return dev_qdisc_change_tx_queue_len(dev);
7123         }
7124 
7125         return 0;
7126 }
7127 
7128 /**
7129  *      dev_set_group - Change group this device belongs to
7130  *      @dev: device
7131  *      @new_group: group this device should belong to
7132  */
7133 void dev_set_group(struct net_device *dev, int new_group)
7134 {
7135         dev->group = new_group;
7136 }
7137 EXPORT_SYMBOL(dev_set_group);
7138 
7139 /**
7140  *      dev_set_mac_address - Change Media Access Control Address
7141  *      @dev: device
7142  *      @sa: new address
7143  *
7144  *      Change the hardware (MAC) address of the device
7145  */
7146 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
7147 {
7148         const struct net_device_ops *ops = dev->netdev_ops;
7149         int err;
7150 
7151         if (!ops->ndo_set_mac_address)
7152                 return -EOPNOTSUPP;
7153         if (sa->sa_family != dev->type)
7154                 return -EINVAL;
7155         if (!netif_device_present(dev))
7156                 return -ENODEV;
7157         err = ops->ndo_set_mac_address(dev, sa);
7158         if (err)
7159                 return err;
7160         dev->addr_assign_type = NET_ADDR_SET;
7161         call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
7162         add_device_randomness(dev->dev_addr, dev->addr_len);
7163         return 0;
7164 }
7165 EXPORT_SYMBOL(dev_set_mac_address);
7166 
7167 /**
7168  *      dev_change_carrier - Change device carrier
7169  *      @dev: device
7170  *      @new_carrier: new value
7171  *
7172  *      Change device carrier
7173  */
7174 int dev_change_carrier(struct net_device *dev, bool new_carrier)
7175 {
7176         const struct net_device_ops *ops = dev->netdev_ops;
7177 
7178         if (!ops->ndo_change_carrier)
7179                 return -EOPNOTSUPP;
7180         if (!netif_device_present(dev))
7181                 return -ENODEV;
7182         return ops->ndo_change_carrier(dev, new_carrier);
7183 }
7184 EXPORT_SYMBOL(dev_change_carrier);
7185 
7186 /**
7187  *      dev_get_phys_port_id - Get device physical port ID
7188  *      @dev: device
7189  *      @ppid: port ID
7190  *
7191  *      Get device physical port ID
7192  */
7193 int dev_get_phys_port_id(struct net_device *dev,
7194                          struct netdev_phys_item_id *ppid)
7195 {
7196         const struct net_device_ops *ops = dev->netdev_ops;
7197 
7198         if (!ops->ndo_get_phys_port_id)
7199                 return -EOPNOTSUPP;
7200         return ops->ndo_get_phys_port_id(dev, ppid);
7201 }
7202 EXPORT_SYMBOL(dev_get_phys_port_id);
7203 
7204 /**
7205  *      dev_get_phys_port_name - Get device physical port name
7206  *      @dev: device
7207  *      @name: port name
7208  *      @len: limit of bytes to copy to name
7209  *
7210  *      Get device physical port name
7211  */
7212 int dev_get_phys_port_name(struct net_device *dev,
7213                            char *name, size_t len)
7214 {
7215         const struct net_device_ops *ops = dev->netdev_ops;
7216 
7217         if (!ops->ndo_get_phys_port_name)
7218                 return -EOPNOTSUPP;
7219         return ops->ndo_get_phys_port_name(dev, name, len);
7220 }
7221 EXPORT_SYMBOL(dev_get_phys_port_name);
7222 
7223 /**
7224  *      dev_change_proto_down - update protocol port state information
7225  *      @dev: device
7226  *      @proto_down: new value
7227  *
7228  *      This info can be used by switch drivers to set the phys state of the
7229  *      port.
7230  */
7231 int dev_change_proto_down(struct net_device *dev, bool proto_down)
7232 {
7233         const struct net_device_ops *ops = dev->netdev_ops;
7234 
7235         if (!ops->ndo_change_proto_down)
7236                 return -EOPNOTSUPP;
7237         if (!netif_device_present(dev))
7238                 return -ENODEV;
7239         return ops->ndo_change_proto_down(dev, proto_down);
7240 }
7241 EXPORT_SYMBOL(dev_change_proto_down);
7242 
7243 void __dev_xdp_query(struct net_device *dev, bpf_op_t bpf_op,
7244                      struct netdev_bpf *xdp)
7245 {
7246         memset(xdp, 0, sizeof(*xdp));
7247         xdp->command = XDP_QUERY_PROG;
7248 
7249         /* Query must always succeed. */
7250         WARN_ON(bpf_op(dev, xdp) < 0);
7251 }
7252 
7253 static u8 __dev_xdp_attached(struct net_device *dev, bpf_op_t bpf_op)
7254 {
7255         struct netdev_bpf xdp;
7256 
7257         __dev_xdp_query(dev, bpf_op, &xdp);
7258 
7259         return xdp.prog_attached;
7260 }
7261 
7262 static int dev_xdp_install(struct net_device *dev, bpf_op_t bpf_op,
7263                            struct netlink_ext_ack *extack, u32 flags,
7264                            struct bpf_prog *prog)
7265 {
7266         struct netdev_bpf xdp;
7267 
7268         memset(&xdp, 0, sizeof(xdp));
7269         if (flags & XDP_FLAGS_HW_MODE)
7270                 xdp.command = XDP_SETUP_PROG_HW;
7271         else
7272                 xdp.command = XDP_SETUP_PROG;
7273         xdp.extack = extack;
7274         xdp.flags = flags;
7275         xdp.prog = prog;
7276 
7277         return bpf_op(dev, &xdp);
7278 }
7279 
7280 static void dev_xdp_uninstall(struct net_device *dev)
7281 {
7282         struct netdev_bpf xdp;
7283         bpf_op_t ndo_bpf;
7284 
7285         /* Remove generic XDP */
7286         WARN_ON(dev_xdp_install(dev, generic_xdp_install, NULL, 0, NULL));
7287 
7288         /* Remove from the driver */
7289         ndo_bpf = dev->netdev_ops->ndo_bpf;
7290         if (!ndo_bpf)
7291                 return;
7292 
7293         __dev_xdp_query(dev, ndo_bpf, &xdp);
7294         if (xdp.prog_attached == XDP_ATTACHED_NONE)
7295                 return;
7296 
7297         /* Program removal should always succeed */
7298         WARN_ON(dev_xdp_install(dev, ndo_bpf, NULL, xdp.prog_flags, NULL));
7299 }
7300 
7301 /**
7302  *      dev_change_xdp_fd - set or clear a bpf program for a device rx path
7303  *      @dev: device
7304  *      @extack: netlink extended ack
7305  *      @fd: new program fd or negative value to clear
7306  *      @flags: xdp-related flags
7307  *
7308  *      Set or clear a bpf program for a device
7309  */
7310 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
7311                       int fd, u32 flags)
7312 {
7313         const struct net_device_ops *ops = dev->netdev_ops;
7314         struct bpf_prog *prog = NULL;
7315         bpf_op_t bpf_op, bpf_chk;
7316         int err;
7317 
7318         ASSERT_RTNL();
7319 
7320         bpf_op = bpf_chk = ops->ndo_bpf;
7321         if (!bpf_op && (flags & (XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE)))
7322                 return -EOPNOTSUPP;
7323         if (!bpf_op || (flags & XDP_FLAGS_SKB_MODE))
7324                 bpf_op = generic_xdp_install;
7325         if (bpf_op == bpf_chk)
7326                 bpf_chk = generic_xdp_install;
7327 
7328         if (fd >= 0) {
7329                 if (bpf_chk && __dev_xdp_attached(dev, bpf_chk))
7330                         return -EEXIST;
7331                 if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) &&
7332                     __dev_xdp_attached(dev, bpf_op))
7333                         return -EBUSY;
7334 
7335                 prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
7336                                              bpf_op == ops->ndo_bpf);
7337                 if (IS_ERR(prog))
7338                         return PTR_ERR(prog);
7339 
7340                 if (!(flags & XDP_FLAGS_HW_MODE) &&
7341                     bpf_prog_is_dev_bound(prog->aux)) {
7342                         NL_SET_ERR_MSG(extack, "using device-bound program without HW_MODE flag is not supported");
7343                         bpf_prog_put(prog);
7344                         return -EINVAL;
7345                 }
7346         }
7347 
7348         err = dev_xdp_install(dev, bpf_op, extack, flags, prog);
7349         if (err < 0 && prog)
7350                 bpf_prog_put(prog);
7351 
7352         return err;
7353 }
7354 
7355 /**
7356  *      dev_new_index   -       allocate an ifindex
7357  *      @net: the applicable net namespace
7358  *
7359  *      Returns a suitable unique value for a new device interface
7360  *      number.  The caller must hold the rtnl semaphore or the
7361  *      dev_base_lock to be sure it remains unique.
7362  */
7363 static int dev_new_index(struct net *net)
7364 {
7365         int ifindex = net->ifindex;
7366 
7367         for (;;) {
7368                 if (++ifindex <= 0)
7369                         ifindex = 1;
7370                 if (!__dev_get_by_index(net, ifindex))
7371                         return net->ifindex = ifindex;
7372         }
7373 }
7374 
7375 /* Delayed registration/unregisteration */
7376 static LIST_HEAD(net_todo_list);
7377 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
7378 
7379 static void net_set_todo(struct net_device *dev)
7380 {
7381         list_add_tail(&dev->todo_list, &net_todo_list);
7382         dev_net(dev)->dev_unreg_count++;
7383 }
7384 
7385 static void rollback_registered_many(struct list_head *head)
7386 {
7387         struct net_device *dev, *tmp;
7388         LIST_HEAD(close_head);
7389 
7390         BUG_ON(dev_boot_phase);
7391         ASSERT_RTNL();
7392 
7393         list_for_each_entry_safe(dev, tmp, head, unreg_list) {
7394                 /* Some devices call without registering
7395                  * for initialization unwind. Remove those
7396                  * devices and proceed with the remaining.
7397                  */
7398                 if (dev->reg_state == NETREG_UNINITIALIZED) {
7399                         pr_debug("unregister_netdevice: device %s/%p never was registered\n",
7400                                  dev->name, dev);
7401 
7402                         WARN_ON(1);
7403                         list_del(&dev->unreg_list);
7404                         continue;
7405                 }
7406                 dev->dismantle = true;
7407                 BUG_ON(dev->reg_state != NETREG_REGISTERED);
7408         }
7409 
7410         /* If device is running, close it first. */
7411         list_for_each_entry(dev, head, unreg_list)
7412                 list_add_tail(&dev->close_list, &close_head);
7413         dev_close_many(&close_head, true);
7414 
7415         list_for_each_entry(dev, head, unreg_list) {
7416                 /* And unlink it from device chain. */
7417                 unlist_netdevice(dev);
7418 
7419                 dev->reg_state = NETREG_UNREGISTERING;
7420         }
7421         flush_all_backlogs();
7422 
7423         synchronize_net();
7424 
7425         list_for_each_entry(dev, head, unreg_list) {
7426                 struct sk_buff *skb = NULL;
7427 
7428                 /* Shutdown queueing discipline. */
7429                 dev_shutdown(dev);
7430 
7431                 dev_xdp_uninstall(dev);
7432 
7433                 /* Notify protocols, that we are about to destroy
7434                  * this device. They should clean all the things.
7435                  */
7436                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
7437 
7438                 if (!dev->rtnl_link_ops ||
7439                     dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
7440                         skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
7441                                                      GFP_KERNEL, NULL, 0);
7442 
7443                 /*
7444                  *      Flush the unicast and multicast chains
7445                  */
7446                 dev_uc_flush(dev);
7447                 dev_mc_flush(dev);
7448 
7449                 if (dev->netdev_ops->ndo_uninit)
7450                         dev->netdev_ops->ndo_uninit(dev);
7451 
7452                 if (skb)
7453                         rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
7454 
7455                 /* Notifier chain MUST detach us all upper devices. */
7456                 WARN_ON(netdev_has_any_upper_dev(dev));
7457                 WARN_ON(netdev_has_any_lower_dev(dev));
7458 
7459                 /* Remove entries from kobject tree */
7460                 netdev_unregister_kobject(dev);
7461 #ifdef CONFIG_XPS
7462                 /* Remove XPS queueing entries */
7463                 netif_reset_xps_queues_gt(dev, 0);
7464 #endif
7465         }
7466 
7467         synchronize_net();
7468 
7469         list_for_each_entry(dev, head, unreg_list)
7470                 dev_put(dev);
7471 }
7472 
7473 static void rollback_registered(struct net_device *dev)
7474 {
7475         LIST_HEAD(single);
7476 
7477         list_add(&dev->unreg_list, &single);
7478         rollback_registered_many(&single);
7479         list_del(&single);
7480 }
7481 
7482 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
7483         struct net_device *upper, netdev_features_t features)
7484 {
7485         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
7486         netdev_features_t feature;
7487         int feature_bit;
7488 
7489         for_each_netdev_feature(&upper_disables, feature_bit) {
7490                 feature = __NETIF_F_BIT(feature_bit);
7491                 if (!(upper->wanted_features & feature)
7492                     && (features & feature)) {
7493                         netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
7494                                    &feature, upper->name);
7495                         features &= ~feature;
7496                 }
7497         }
7498 
7499         return features;
7500 }
7501 
7502 static void netdev_sync_lower_features(struct net_device *upper,
7503         struct net_device *lower, netdev_features_t features)
7504 {
7505         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
7506         netdev_features_t feature;
7507         int feature_bit;
7508 
7509         for_each_netdev_feature(&upper_disables, feature_bit) {
7510                 feature = __NETIF_F_BIT(feature_bit);
7511                 if (!(features & feature) && (lower->features & feature)) {
7512                         netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
7513                                    &feature, lower->name);
7514                         lower->wanted_features &= ~feature;
7515                         netdev_update_features(lower);
7516 
7517                         if (unlikely(lower->features & feature))
7518                                 netdev_WARN(upper, "failed to disable %pNF on %s!\n",
7519                                             &feature, lower->name);
7520                 }
7521         }
7522 }
7523 
7524 static netdev_features_t netdev_fix_features(struct net_device *dev,
7525         netdev_features_t features)
7526 {
7527         /* Fix illegal checksum combinations */
7528         if ((features & NETIF_F_HW_CSUM) &&
7529             (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
7530                 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
7531                 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
7532         }
7533 
7534         /* TSO requires that SG is present as well. */
7535         if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
7536                 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
7537                 features &= ~NETIF_F_ALL_TSO;
7538         }
7539 
7540         if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
7541                                         !(features & NETIF_F_IP_CSUM)) {
7542                 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
7543                 features &= ~NETIF_F_TSO;
7544                 features &= ~NETIF_F_TSO_ECN;
7545         }
7546 
7547         if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
7548                                          !(features & NETIF_F_IPV6_CSUM)) {
7549                 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
7550                 features &= ~NETIF_F_TSO6;
7551         }
7552 
7553         /* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
7554         if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
7555                 features &= ~NETIF_F_TSO_MANGLEID;
7556 
7557         /* TSO ECN requires that TSO is present as well. */
7558         if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
7559                 features &= ~NETIF_F_TSO_ECN;
7560 
7561         /* Software GSO depends on SG. */
7562         if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
7563                 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
7564                 features &= ~NETIF_F_GSO;
7565         }
7566 
7567         /* GSO partial features require GSO partial be set */
7568         if ((features & dev->gso_partial_features) &&
7569             !(features & NETIF_F_GSO_PARTIAL)) {
7570                 netdev_dbg(dev,
7571                            "Dropping partially supported GSO features since no GSO partial.\n");
7572                 features &= ~dev->gso_partial_features;
7573         }
7574 
7575         if (!(features & NETIF_F_RXCSUM)) {
7576                 /* NETIF_F_GRO_HW implies doing RXCSUM since every packet
7577                  * successfully merged by hardware must also have the
7578                  * checksum verified by hardware.  If the user does not
7579                  * want to enable RXCSUM, logically, we should disable GRO_HW.
7580                  */
7581                 if (features & NETIF_F_GRO_HW) {
7582                         netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
7583                         features &= ~NETIF_F_GRO_HW;
7584                 }
7585         }
7586 
7587         /* LRO/HW-GRO features cannot be combined with RX-FCS */
7588         if (features & NETIF_F_RXFCS) {
7589                 if (features & NETIF_F_LRO) {
7590                         netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
7591                         features &= ~NETIF_F_LRO;
7592                 }
7593 
7594                 if (features & NETIF_F_GRO_HW) {
7595                         netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
7596                         features &= ~NETIF_F_GRO_HW;
7597                 }
7598         }
7599 
7600         return features;
7601 }
7602 
7603 int __netdev_update_features(struct net_device *dev)
7604 {
7605         struct net_device *upper, *lower;
7606         netdev_features_t features;
7607         struct list_head *iter;
7608         int err = -1;
7609 
7610         ASSERT_RTNL();
7611 
7612         features = netdev_get_wanted_features(dev);
7613 
7614         if (dev->netdev_ops->ndo_fix_features)
7615                 features = dev->netdev_ops->ndo_fix_features(dev, features);
7616 
7617         /* driver might be less strict about feature dependencies */
7618         features = netdev_fix_features(dev, features);
7619 
7620         /* some features can't be enabled if they're off an an upper device */
7621         netdev_for_each_upper_dev_rcu(dev, upper, iter)
7622                 features = netdev_sync_upper_features(dev, upper, features);
7623 
7624         if (dev->features == features)
7625                 goto sync_lower;
7626 
7627         netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
7628                 &dev->features, &features);
7629 
7630         if (dev->netdev_ops->ndo_set_features)
7631                 err = dev->netdev_ops->ndo_set_features(dev, features);
7632         else
7633                 err = 0;
7634 
7635         if (unlikely(err < 0)) {
7636                 netdev_err(dev,
7637                         "set_features() failed (%d); wanted %pNF, left %pNF\n",
7638                         err, &features, &dev->features);
7639                 /* return non-0 since some features might have changed and
7640                  * it's better to fire a spurious notification than miss it
7641                  */
7642                 return -1;
7643         }
7644 
7645 sync_lower:
7646         /* some features must be disabled on lower devices when disabled
7647          * on an upper device (think: bonding master or bridge)
7648          */
7649         netdev_for_each_lower_dev(dev, lower, iter)
7650                 netdev_sync_lower_features(dev, lower, features);
7651 
7652         if (!err) {
7653                 netdev_features_t diff = features ^ dev->features;
7654 
7655                 if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
7656                         /* udp_tunnel_{get,drop}_rx_info both need
7657                          * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
7658                          * device, or they won't do anything.
7659                          * Thus we need to update dev->features
7660                          * *before* calling udp_tunnel_get_rx_info,
7661                          * but *after* calling udp_tunnel_drop_rx_info.
7662                          */
7663                         if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
7664                                 dev->features = features;
7665                                 udp_tunnel_get_rx_info(dev);
7666                         } else {
7667                                 udp_tunnel_drop_rx_info(dev);
7668                         }
7669                 }
7670 
7671                 if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
7672                         if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
7673                                 dev->features = features;
7674                                 err |= vlan_get_rx_ctag_filter_info(dev);
7675                         } else {
7676                                 vlan_drop_rx_ctag_filter_info(dev);
7677                         }
7678                 }
7679 
7680                 if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
7681                         if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
7682                                 dev->features = features;
7683                                 err |= vlan_get_rx_stag_filter_info(dev);
7684                         } else {
7685                                 vlan_drop_rx_stag_filter_info(dev);
7686                         }
7687                 }
7688 
7689                 dev->features = features;
7690         }
7691 
7692         return err < 0 ? 0 : 1;
7693 }
7694 
7695 /**
7696  *      netdev_update_features - recalculate device features
7697  *      @dev: the device to check
7698  *
7699  *      Recalculate dev->features set and send notifications if it
7700  *      has changed. Should be called after driver or hardware dependent
7701  *      conditions might have changed that influence the features.
7702  */
7703 void netdev_update_features(struct net_device *dev)
7704 {
7705         if (__netdev_update_features(dev))
7706                 netdev_features_change(dev);
7707 }
7708 EXPORT_SYMBOL(netdev_update_features);
7709 
7710 /**
7711  *      netdev_change_features - recalculate device features
7712  *      @dev: the device to check
7713  *
7714  *      Recalculate dev->features set and send notifications even
7715  *      if they have not changed. Should be called instead of
7716  *      netdev_update_features() if also dev->vlan_features might
7717  *      have changed to allow the changes to be propagated to stacked
7718  *      VLAN devices.
7719  */
7720 void netdev_change_features(struct net_device *dev)
7721 {
7722         __netdev_update_features(dev);
7723         netdev_features_change(dev);
7724 }
7725 EXPORT_SYMBOL(netdev_change_features);
7726 
7727 /**
7728  *      netif_stacked_transfer_operstate -      transfer operstate
7729  *      @rootdev: the root or lower level device to transfer state from
7730  *      @dev: the device to transfer operstate to
7731  *
7732  *      Transfer operational state from root to device. This is normally
7733  *      called when a stacking relationship exists between the root
7734  *      device and the device(a leaf device).
7735  */
7736 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
7737                                         struct net_device *dev)
7738 {
7739         if (rootdev->operstate == IF_OPER_DORMANT)
7740                 netif_dormant_on(dev);
7741         else
7742                 netif_dormant_off(dev);
7743 
7744         if (netif_carrier_ok(rootdev))
7745                 netif_carrier_on(dev);
7746         else
7747                 netif_carrier_off(dev);
7748 }
7749 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
7750 
7751 static int netif_alloc_rx_queues(struct net_device *dev)
7752 {
7753         unsigned int i, count = dev->num_rx_queues;
7754         struct netdev_rx_queue *rx;
7755         size_t sz = count * sizeof(*rx);
7756         int err = 0;
7757 
7758         BUG_ON(count < 1);
7759 
7760         rx = kvzalloc(sz, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
7761         if (!rx)
7762                 return -ENOMEM;
7763 
7764         dev->_rx = rx;
7765 
7766         for (i = 0; i < count; i++) {
7767                 rx[i].dev = dev;
7768 
7769                 /* XDP RX-queue setup */
7770                 err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i);
7771                 if (err < 0)
7772                         goto err_rxq_info;
7773         }
7774         return 0;
7775 
7776 err_rxq_info:
7777         /* Rollback successful reg's and free other resources */
7778         while (i--)
7779                 xdp_rxq_info_unreg(&rx[i].xdp_rxq);
7780         kvfree(dev->_rx);
7781         dev->_rx = NULL;
7782         return err;
7783 }
7784 
7785 static void netif_free_rx_queues(struct net_device *dev)
7786 {
7787         unsigned int i, count = dev->num_rx_queues;
7788 
7789         /* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
7790         if (!dev->_rx)
7791                 return;
7792 
7793         for (i = 0; i < count; i++)
7794                 xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
7795 
7796         kvfree(dev->_rx);
7797 }
7798 
7799 static void netdev_init_one_queue(struct net_device *dev,
7800                                   struct netdev_queue *queue, void *_unused)
7801 {
7802         /* Initialize queue lock */
7803         spin_lock_init(&queue->_xmit_lock);
7804         netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
7805         queue->xmit_lock_owner = -1;
7806         netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
7807         queue->dev = dev;
7808 #ifdef CONFIG_BQL
7809         dql_init(&queue->dql, HZ);
7810 #endif
7811 }
7812 
7813 static void netif_free_tx_queues(struct net_device *dev)
7814 {
7815         kvfree(dev->_tx);
7816 }
7817 
7818 static int netif_alloc_netdev_queues(struct net_device *dev)
7819 {
7820         unsigned int count = dev->num_tx_queues;
7821         struct netdev_queue *tx;
7822         size_t sz = count * sizeof(*tx);
7823 
7824         if (count < 1 || count > 0xffff)
7825                 return -EINVAL;
7826 
7827         tx = kvzalloc(sz, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
7828         if (!tx)
7829                 return -ENOMEM;
7830 
7831         dev->_tx = tx;
7832 
7833         netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
7834         spin_lock_init(&dev->tx_global_lock);
7835 
7836         return 0;
7837 }
7838 
7839 void netif_tx_stop_all_queues(struct net_device *dev)
7840 {
7841         unsigned int i;
7842 
7843         for (i = 0; i < dev->num_tx_queues; i++) {
7844                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
7845 
7846                 netif_tx_stop_queue(txq);
7847         }
7848 }
7849 EXPORT_SYMBOL(netif_tx_stop_all_queues);
7850 
7851 /**
7852  *      register_netdevice      - register a network device
7853  *      @dev: device to register
7854  *
7855  *      Take a completed network device structure and add it to the kernel
7856  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
7857  *      chain. 0 is returned on success. A negative errno code is returned
7858  *      on a failure to set up the device, or if the name is a duplicate.
7859  *
7860  *      Callers must hold the rtnl semaphore. You may want
7861  *      register_netdev() instead of this.
7862  *
7863  *      BUGS:
7864  *      The locking appears insufficient to guarantee two parallel registers
7865  *      will not get the same name.
7866  */
7867 
7868 int register_netdevice(struct net_device *dev)
7869 {
7870         int ret;
7871         struct net *net = dev_net(dev);
7872 
7873         BUG_ON(dev_boot_phase);
7874         ASSERT_RTNL();
7875 
7876         might_sleep();
7877 
7878         /* When net_device's are persistent, this will be fatal. */
7879         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
7880         BUG_ON(!net);
7881 
7882         spin_lock_init(&dev->addr_list_lock);
7883         netdev_set_addr_lockdep_class(dev);
7884 
7885         ret = dev_get_valid_name(net, dev, dev->name);
7886         if (ret < 0)
7887                 goto out;
7888 
7889         /* Init, if this function is available */
7890         if (dev->netdev_ops->ndo_init) {
7891                 ret = dev->netdev_ops->ndo_init(dev);
7892                 if (ret) {
7893                         if (ret > 0)
7894                                 ret = -EIO;
7895                         goto out;
7896                 }
7897         }
7898 
7899         if (((dev->hw_features | dev->features) &
7900              NETIF_F_HW_VLAN_CTAG_FILTER) &&
7901             (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
7902              !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
7903                 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
7904                 ret = -EINVAL;
7905                 goto err_uninit;
7906         }
7907 
7908         ret = -EBUSY;
7909         if (!dev->ifindex)
7910                 dev->ifindex = dev_new_index(net);
7911         else if (__dev_get_by_index(net, dev->ifindex))
7912                 goto err_uninit;
7913 
7914         /* Transfer changeable features to wanted_features and enable
7915          * software offloads (GSO and GRO).
7916          */
7917         dev->hw_features |= NETIF_F_SOFT_FEATURES;
7918         dev->features |= NETIF_F_SOFT_FEATURES;
7919 
7920         if (dev->netdev_ops->ndo_udp_tunnel_add) {
7921                 dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
7922                 dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
7923         }
7924 
7925         dev->wanted_features = dev->features & dev->hw_features;
7926 
7927         if (!(dev->flags & IFF_LOOPBACK))
7928                 dev->hw_features |= NETIF_F_NOCACHE_COPY;
7929 
7930         /* If IPv4 TCP segmentation offload is supported we should also
7931          * allow the device to enable segmenting the frame with the option
7932          * of ignoring a static IP ID value.  This doesn't enable the
7933          * feature itself but allows the user to enable it later.
7934          */
7935         if (dev->hw_features & NETIF_F_TSO)
7936                 dev->hw_features |= NETIF_F_TSO_MANGLEID;
7937         if (dev->vlan_features & NETIF_F_TSO)
7938                 dev->vlan_features |= NETIF_F_TSO_MANGLEID;
7939         if (dev->mpls_features & NETIF_F_TSO)
7940                 dev->mpls_features |= NETIF_F_TSO_MANGLEID;
7941         if (dev->hw_enc_features & NETIF_F_TSO)
7942                 dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
7943 
7944         /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
7945          */
7946         dev->vlan_features |= NETIF_F_HIGHDMA;
7947 
7948         /* Make NETIF_F_SG inheritable to tunnel devices.
7949          */
7950         dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
7951 
7952         /* Make NETIF_F_SG inheritable to MPLS.
7953          */
7954         dev->mpls_features |= NETIF_F_SG;
7955 
7956         ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
7957         ret = notifier_to_errno(ret);
7958         if (ret)
7959                 goto err_uninit;
7960 
7961         ret = netdev_register_kobject(dev);
7962         if (ret)
7963                 goto err_uninit;
7964         dev->reg_state = NETREG_REGISTERED;
7965 
7966         __netdev_update_features(dev);
7967 
7968         /*
7969          *      Default initial state at registry is that the
7970          *      device is present.
7971          */
7972 
7973         set_bit(__LINK_STATE_PRESENT, &dev->state);
7974 
7975         linkwatch_init_dev(dev);
7976 
7977         dev_init_scheduler(dev);
7978         dev_hold(dev);
7979         list_netdevice(dev);
7980         add_device_randomness(dev->dev_addr, dev->addr_len);
7981 
7982         /* If the device has permanent device address, driver should
7983          * set dev_addr and also addr_assign_type should be set to
7984          * NET_ADDR_PERM (default value).
7985          */
7986         if (dev->addr_assign_type == NET_ADDR_PERM)
7987                 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
7988 
7989         /* Notify protocols, that a new device appeared. */
7990         ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
7991         ret = notifier_to_errno(ret);
7992         if (ret) {
7993                 rollback_registered(dev);
7994                 dev->reg_state = NETREG_UNREGISTERED;
7995         }
7996         /*
7997          *      Prevent userspace races by waiting until the network
7998          *      device is fully setup before sending notifications.
7999          */
8000         if (!dev->rtnl_link_ops ||
8001             dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
8002                 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
8003 
8004 out:
8005         return ret;
8006 
8007 err_uninit:
8008         if (dev->netdev_ops->ndo_uninit)
8009                 dev->netdev_ops->ndo_uninit(dev);
8010         if (dev->priv_destructor)
8011                 dev->priv_destructor(dev);
8012         goto out;
8013 }
8014 EXPORT_SYMBOL(register_netdevice);
8015 
8016 /**
8017  *      init_dummy_netdev       - init a dummy network device for NAPI
8018  *      @dev: device to init
8019  *
8020  *      This takes a network device structure and initialize the minimum
8021  *      amount of fields so it can be used to schedule NAPI polls without
8022  *      registering a full blown interface. This is to be used by drivers
8023  *      that need to tie several hardware interfaces to a single NAPI
8024  *      poll scheduler due to HW limitations.
8025  */
8026 int init_dummy_netdev(struct net_device *dev)
8027 {
8028         /* Clear everything. Note we don't initialize spinlocks
8029          * are they aren't supposed to be taken by any of the
8030          * NAPI code and this dummy netdev is supposed to be
8031          * only ever used for NAPI polls
8032          */
8033         memset(dev, 0, sizeof(struct net_device));
8034 
8035         /* make sure we BUG if trying to hit standard
8036          * register/unregister code path
8037          */
8038         dev->reg_state = NETREG_DUMMY;
8039 
8040         /* NAPI wants this */
8041         INIT_LIST_HEAD(&dev->napi_list);
8042 
8043         /* a dummy interface is started by default */
8044         set_bit(__LINK_STATE_PRESENT, &dev->state);
8045         set_bit(__LINK_STATE_START, &dev->state);
8046 
8047         /* Note : We dont allocate pcpu_refcnt for dummy devices,
8048          * because users of this 'device' dont need to change
8049          * its refcount.
8050          */
8051 
8052         return 0;
8053 }
8054 EXPORT_SYMBOL_GPL(init_dummy_netdev);
8055 
8056 
8057 /**
8058  *      register_netdev - register a network device
8059  *      @dev: device to register
8060  *
8061  *      Take a completed network device structure and add it to the kernel
8062  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
8063  *      chain. 0 is returned on success. A negative errno code is returned
8064  *      on a failure to set up the device, or if the name is a duplicate.
8065  *
8066  *      This is a wrapper around register_netdevice that takes the rtnl semaphore
8067  *      and expands the device name if you passed a format string to
8068  *      alloc_netdev.
8069  */
8070 int register_netdev(struct net_device *dev)
8071 {
8072         int err;
8073 
8074         if (rtnl_lock_killable())
8075                 return -EINTR;
8076         err = register_netdevice(dev);
8077         rtnl_unlock();
8078         return err;
8079 }
8080 EXPORT_SYMBOL(register_netdev);
8081 
8082 int netdev_refcnt_read(const struct net_device *dev)
8083 {
8084         int i, refcnt = 0;
8085 
8086         for_each_possible_cpu(i)
8087                 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
8088         return refcnt;
8089 }
8090 EXPORT_SYMBOL(netdev_refcnt_read);
8091 
8092 /**
8093  * netdev_wait_allrefs - wait until all references are gone.
8094  * @dev: target net_device
8095  *
8096  * This is called when unregistering network devices.
8097  *
8098  * Any protocol or device that holds a reference should register
8099  * for netdevice notification, and cleanup and put back the
8100  * reference if they receive an UNREGISTER event.
8101  * We can get stuck here if buggy protocols don't correctly
8102  * call dev_put.
8103  */
8104 static void netdev_wait_allrefs(struct net_device *dev)
8105 {
8106         unsigned long rebroadcast_time, warning_time;
8107         int refcnt;
8108 
8109         linkwatch_forget_dev(dev);
8110 
8111         rebroadcast_time = warning_time = jiffies;
8112         refcnt = netdev_refcnt_read(dev);
8113 
8114         while (refcnt != 0) {
8115                 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
8116                         rtnl_lock();
8117 
8118                         /* Rebroadcast unregister notification */
8119                         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
8120 
8121                         __rtnl_unlock();
8122                         rcu_barrier();
8123                         rtnl_lock();
8124 
8125                         if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
8126                                      &dev->state)) {
8127                                 /* We must not have linkwatch events
8128                                  * pending on unregister. If this
8129                                  * happens, we simply run the queue
8130                                  * unscheduled, resulting in a noop
8131                                  * for this device.
8132                                  */
8133                                 linkwatch_run_queue();
8134                         }
8135 
8136                         __rtnl_unlock();
8137 
8138                         rebroadcast_time = jiffies;
8139                 }
8140 
8141                 msleep(250);
8142 
8143                 refcnt = netdev_refcnt_read(dev);
8144 
8145                 if (time_after(jiffies, warning_time + 10 * HZ)) {
8146                         pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
8147                                  dev->name, refcnt);
8148                         warning_time = jiffies;
8149                 }
8150         }
8151 }
8152 
8153 /* The sequence is:
8154  *
8155  *      rtnl_lock();
8156  *      ...
8157  *      register_netdevice(x1);
8158  *      register_netdevice(x2);
8159  *      ...
8160  *      unregister_netdevice(y1);
8161  *      unregister_netdevice(y2);
8162  *      ...
8163  *      rtnl_unlock();
8164  *      free_netdev(y1);
8165  *      free_netdev(y2);
8166  *
8167  * We are invoked by rtnl_unlock().
8168  * This allows us to deal with problems:
8169  * 1) We can delete sysfs objects which invoke hotplug
8170  *    without deadlocking with linkwatch via keventd.
8171  * 2) Since we run with the RTNL semaphore not held, we can sleep
8172  *    safely in order to wait for the netdev refcnt to drop to zero.
8173  *
8174  * We must not return until all unregister events added during
8175  * the interval the lock was held have been completed.
8176  */
8177 void netdev_run_todo(void)
8178 {
8179         struct list_head list;
8180 
8181         /* Snapshot list, allow later requests */
8182         list_replace_init(&net_todo_list, &list);
8183 
8184         __rtnl_unlock();
8185 
8186 
8187         /* Wait for rcu callbacks to finish before next phase */
8188         if (!list_empty(&list))
8189                 rcu_barrier();
8190 
8191         while (!list_empty(&list)) {
8192                 struct net_device *dev
8193                         = list_first_entry(&list, struct net_device, todo_list);
8194                 list_del(&dev->todo_list);
8195 
8196                 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
8197                         pr_err("network todo '%s' but state %d\n",
8198                                dev->name, dev->reg_state);
8199                         dump_stack();
8200                         continue;
8201                 }
8202 
8203                 dev->reg_state = NETREG_UNREGISTERED;
8204 
8205                 netdev_wait_allrefs(dev);
8206 
8207                 /* paranoia */
8208                 BUG_ON(netdev_refcnt_read(dev));
8209                 BUG_ON(!list_empty(&dev->ptype_all));
8210                 BUG_ON(!list_empty(&dev->ptype_specific));
8211                 WARN_ON(rcu_access_pointer(dev->ip_ptr));
8212                 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
8213 #if IS_ENABLED(CONFIG_DECNET)
8214                 WARN_ON(dev->dn_ptr);
8215 #endif
8216                 if (dev->priv_destructor)
8217                         dev->priv_destructor(dev);
8218                 if (dev->needs_free_netdev)
8219                         free_netdev(dev);
8220 
8221                 /* Report a network device has been unregistered */
8222                 rtnl_lock();
8223                 dev_net(dev)->dev_unreg_count--;
8224                 __rtnl_unlock();
8225                 wake_up(&netdev_unregistering_wq);
8226 
8227                 /* Free network device */
8228                 kobject_put(&dev->dev.kobj);
8229         }
8230 }
8231 
8232 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
8233  * all the same fields in the same order as net_device_stats, with only
8234  * the type differing, but rtnl_link_stats64 may have additional fields
8235  * at the end for newer counters.
8236  */
8237 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
8238                              const struct net_device_stats *netdev_stats)
8239 {
8240 #if BITS_PER_LONG == 64
8241         BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats));
8242         memcpy(stats64, netdev_stats, sizeof(*netdev_stats));
8243         /* zero out counters that only exist in rtnl_link_stats64 */
8244         memset((char *)stats64 + sizeof(*netdev_stats), 0,
8245                sizeof(*stats64) - sizeof(*netdev_stats));
8246 #else
8247         size_t i, n = sizeof(*netdev_stats) / sizeof(unsigned long);
8248         const unsigned long *src = (const unsigned long *)netdev_stats;
8249         u64 *dst = (u64 *)stats64;
8250 
8251         BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
8252         for (i = 0; i < n; i++)
8253                 dst[i] = src[i];
8254         /* zero out counters that only exist in rtnl_link_stats64 */
8255         memset((char *)stats64 + n * sizeof(u64), 0,
8256                sizeof(*stats64) - n * sizeof(u64));
8257 #endif
8258 }
8259 EXPORT_SYMBOL(netdev_stats_to_stats64);
8260 
8261 /**
8262  *      dev_get_stats   - get network device statistics
8263  *      @dev: device to get statistics from
8264  *      @storage: place to store stats
8265  *
8266  *      Get network statistics from device. Return @storage.
8267  *      The device driver may provide its own method by setting
8268  *      dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
8269  *      otherwise the internal statistics structure is used.
8270  */
8271 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
8272                                         struct rtnl_link_stats64 *storage)
8273 {
8274         const struct net_device_ops *ops = dev->netdev_ops;
8275 
8276         if (ops->ndo_get_stats64) {
8277                 memset(storage, 0, sizeof(*storage));
8278                 ops->ndo_get_stats64(dev, storage);
8279         } else if (ops->ndo_get_stats) {
8280                 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
8281         } else {
8282                 netdev_stats_to_stats64(storage, &dev->stats);
8283         }
8284         storage->rx_dropped += (unsigned long)atomic_long_read(&dev->rx_dropped);
8285         storage->tx_dropped += (unsigned long)atomic_long_read(&dev->tx_dropped);
8286         storage->rx_nohandler += (unsigned long)atomic_long_read(&dev->rx_nohandler);
8287         return storage;
8288 }
8289 EXPORT_SYMBOL(dev_get_stats);
8290 
8291 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
8292 {
8293         struct netdev_queue *queue = dev_ingress_queue(dev);
8294 
8295 #ifdef CONFIG_NET_CLS_ACT
8296         if (queue)
8297                 return queue;
8298         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
8299         if (!queue)
8300                 return NULL;
8301         netdev_init_one_queue(dev, queue, NULL);
8302         RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
8303         queue->qdisc_sleeping = &noop_qdisc;
8304         rcu_assign_pointer(dev->ingress_queue, queue);
8305 #endif
8306         return queue;
8307 }
8308 
8309 static const struct ethtool_ops default_ethtool_ops;
8310 
8311 void netdev_set_default_ethtool_ops(struct net_device *dev,
8312                                     const struct ethtool_ops *ops)
8313 {
8314         if (dev->ethtool_ops == &default_ethtool_ops)
8315                 dev->ethtool_ops = ops;
8316 }
8317 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
8318 
8319 void netdev_freemem(struct net_device *dev)
8320 {
8321         char *addr = (char *)dev - dev->padded;
8322 
8323         kvfree(addr);
8324 }
8325 
8326 /**
8327  * alloc_netdev_mqs - allocate network device
8328  * @sizeof_priv: size of private data to allocate space for
8329  * @name: device name format string
8330  * @name_assign_type: origin of device name
8331  * @setup: callback to initialize device
8332  * @txqs: the number of TX subqueues to allocate
8333  * @rxqs: the number of RX subqueues to allocate
8334  *
8335  * Allocates a struct net_device with private data area for driver use
8336  * and performs basic initialization.  Also allocates subqueue structs
8337  * for each queue on the device.
8338  */
8339 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
8340                 unsigned char name_assign_type,
8341                 void (*setup)(struct net_device *),
8342                 unsigned int txqs, unsigned int rxqs)
8343 {
8344         struct net_device *dev;
8345         unsigned int alloc_size;
8346         struct net_device *p;
8347 
8348         BUG_ON(strlen(name) >= sizeof(dev->name));
8349 
8350         if (txqs < 1) {
8351                 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
8352                 return NULL;
8353         }
8354 
8355         if (rxqs < 1) {
8356                 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
8357                 return NULL;
8358         }
8359 
8360         alloc_size = sizeof(struct net_device);
8361         if (sizeof_priv) {
8362                 /* ensure 32-byte alignment of private area */
8363                 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
8364                 alloc_size += sizeof_priv;
8365         }
8366         /* ensure 32-byte alignment of whole construct */
8367         alloc_size += NETDEV_ALIGN - 1;
8368 
8369         p = kvzalloc(alloc_size, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
8370         if (!p)
8371                 return NULL;
8372 
8373         dev = PTR_ALIGN(p, NETDEV_ALIGN);
8374         dev->padded = (char *)dev - (char *)p;
8375 
8376         dev->pcpu_refcnt = alloc_percpu(int);
8377         if (!dev->pcpu_refcnt)
8378                 goto free_dev;
8379 
8380         if (dev_addr_init(dev))
8381                 goto free_pcpu;
8382 
8383         dev_mc_init(dev);
8384         dev_uc_init(dev);
8385 
8386         dev_net_set(dev, &init_net);
8387 
8388         dev->gso_max_size = GSO_MAX_SIZE;
8389         dev->gso_max_segs = GSO_MAX_SEGS;
8390 
8391         INIT_LIST_HEAD(&dev->napi_list);
8392         INIT_LIST_HEAD(&dev->unreg_list);
8393         INIT_LIST_HEAD(&dev->close_list);
8394         INIT_L