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TOMOYO Linux Cross Reference
Linux/net/packet/af_packet.c

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  4  *              operating system.  INET is implemented using the  BSD Socket
  5  *              interface as the means of communication with the user level.
  6  *
  7  *              PACKET - implements raw packet sockets.
  8  *
  9  * Authors:     Ross Biro
 10  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 11  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
 12  *
 13  * Fixes:
 14  *              Alan Cox        :       verify_area() now used correctly
 15  *              Alan Cox        :       new skbuff lists, look ma no backlogs!
 16  *              Alan Cox        :       tidied skbuff lists.
 17  *              Alan Cox        :       Now uses generic datagram routines I
 18  *                                      added. Also fixed the peek/read crash
 19  *                                      from all old Linux datagram code.
 20  *              Alan Cox        :       Uses the improved datagram code.
 21  *              Alan Cox        :       Added NULL's for socket options.
 22  *              Alan Cox        :       Re-commented the code.
 23  *              Alan Cox        :       Use new kernel side addressing
 24  *              Rob Janssen     :       Correct MTU usage.
 25  *              Dave Platt      :       Counter leaks caused by incorrect
 26  *                                      interrupt locking and some slightly
 27  *                                      dubious gcc output. Can you read
 28  *                                      compiler: it said _VOLATILE_
 29  *      Richard Kooijman        :       Timestamp fixes.
 30  *              Alan Cox        :       New buffers. Use sk->mac.raw.
 31  *              Alan Cox        :       sendmsg/recvmsg support.
 32  *              Alan Cox        :       Protocol setting support
 33  *      Alexey Kuznetsov        :       Untied from IPv4 stack.
 34  *      Cyrus Durgin            :       Fixed kerneld for kmod.
 35  *      Michal Ostrowski        :       Module initialization cleanup.
 36  *         Ulises Alonso        :       Frame number limit removal and
 37  *                                      packet_set_ring memory leak.
 38  *              Eric Biederman  :       Allow for > 8 byte hardware addresses.
 39  *                                      The convention is that longer addresses
 40  *                                      will simply extend the hardware address
 41  *                                      byte arrays at the end of sockaddr_ll
 42  *                                      and packet_mreq.
 43  *              Johann Baudy    :       Added TX RING.
 44  *              Chetan Loke     :       Implemented TPACKET_V3 block abstraction
 45  *                                      layer.
 46  *                                      Copyright (C) 2011, <lokec@ccs.neu.edu>
 47  */
 48 
 49 #include <linux/types.h>
 50 #include <linux/mm.h>
 51 #include <linux/capability.h>
 52 #include <linux/fcntl.h>
 53 #include <linux/socket.h>
 54 #include <linux/in.h>
 55 #include <linux/inet.h>
 56 #include <linux/netdevice.h>
 57 #include <linux/if_packet.h>
 58 #include <linux/wireless.h>
 59 #include <linux/kernel.h>
 60 #include <linux/kmod.h>
 61 #include <linux/slab.h>
 62 #include <linux/vmalloc.h>
 63 #include <net/net_namespace.h>
 64 #include <net/ip.h>
 65 #include <net/protocol.h>
 66 #include <linux/skbuff.h>
 67 #include <net/sock.h>
 68 #include <linux/errno.h>
 69 #include <linux/timer.h>
 70 #include <linux/uaccess.h>
 71 #include <asm/ioctls.h>
 72 #include <asm/page.h>
 73 #include <asm/cacheflush.h>
 74 #include <asm/io.h>
 75 #include <linux/proc_fs.h>
 76 #include <linux/seq_file.h>
 77 #include <linux/poll.h>
 78 #include <linux/module.h>
 79 #include <linux/init.h>
 80 #include <linux/mutex.h>
 81 #include <linux/if_vlan.h>
 82 #include <linux/virtio_net.h>
 83 #include <linux/errqueue.h>
 84 #include <linux/net_tstamp.h>
 85 #include <linux/percpu.h>
 86 #ifdef CONFIG_INET
 87 #include <net/inet_common.h>
 88 #endif
 89 #include <linux/bpf.h>
 90 #include <net/compat.h>
 91 
 92 #include "internal.h"
 93 
 94 /*
 95    Assumptions:
 96    - if device has no dev->hard_header routine, it adds and removes ll header
 97      inside itself. In this case ll header is invisible outside of device,
 98      but higher levels still should reserve dev->hard_header_len.
 99      Some devices are enough clever to reallocate skb, when header
100      will not fit to reserved space (tunnel), another ones are silly
101      (PPP).
102    - packet socket receives packets with pulled ll header,
103      so that SOCK_RAW should push it back.
104 
105 On receive:
106 -----------
107 
108 Incoming, dev->hard_header!=NULL
109    mac_header -> ll header
110    data       -> data
111 
112 Outgoing, dev->hard_header!=NULL
113    mac_header -> ll header
114    data       -> ll header
115 
116 Incoming, dev->hard_header==NULL
117    mac_header -> UNKNOWN position. It is very likely, that it points to ll
118                  header.  PPP makes it, that is wrong, because introduce
119                  assymetry between rx and tx paths.
120    data       -> data
121 
122 Outgoing, dev->hard_header==NULL
123    mac_header -> data. ll header is still not built!
124    data       -> data
125 
126 Resume
127   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
128 
129 
130 On transmit:
131 ------------
132 
133 dev->hard_header != NULL
134    mac_header -> ll header
135    data       -> ll header
136 
137 dev->hard_header == NULL (ll header is added by device, we cannot control it)
138    mac_header -> data
139    data       -> data
140 
141    We should set nh.raw on output to correct posistion,
142    packet classifier depends on it.
143  */
144 
145 /* Private packet socket structures. */
146 
147 /* identical to struct packet_mreq except it has
148  * a longer address field.
149  */
150 struct packet_mreq_max {
151         int             mr_ifindex;
152         unsigned short  mr_type;
153         unsigned short  mr_alen;
154         unsigned char   mr_address[MAX_ADDR_LEN];
155 };
156 
157 union tpacket_uhdr {
158         struct tpacket_hdr  *h1;
159         struct tpacket2_hdr *h2;
160         struct tpacket3_hdr *h3;
161         void *raw;
162 };
163 
164 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
165                 int closing, int tx_ring);
166 
167 #define V3_ALIGNMENT    (8)
168 
169 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
170 
171 #define BLK_PLUS_PRIV(sz_of_priv) \
172         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
173 
174 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
175 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
176 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
177 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
178 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
179 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
180 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
181 
182 struct packet_sock;
183 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
184                        struct packet_type *pt, struct net_device *orig_dev);
185 
186 static void *packet_previous_frame(struct packet_sock *po,
187                 struct packet_ring_buffer *rb,
188                 int status);
189 static void packet_increment_head(struct packet_ring_buffer *buff);
190 static int prb_curr_blk_in_use(struct tpacket_block_desc *);
191 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
192                         struct packet_sock *);
193 static void prb_retire_current_block(struct tpacket_kbdq_core *,
194                 struct packet_sock *, unsigned int status);
195 static int prb_queue_frozen(struct tpacket_kbdq_core *);
196 static void prb_open_block(struct tpacket_kbdq_core *,
197                 struct tpacket_block_desc *);
198 static void prb_retire_rx_blk_timer_expired(struct timer_list *);
199 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
200 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
201 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
202                 struct tpacket3_hdr *);
203 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
204                 struct tpacket3_hdr *);
205 static void packet_flush_mclist(struct sock *sk);
206 static u16 packet_pick_tx_queue(struct sk_buff *skb);
207 
208 struct packet_skb_cb {
209         union {
210                 struct sockaddr_pkt pkt;
211                 union {
212                         /* Trick: alias skb original length with
213                          * ll.sll_family and ll.protocol in order
214                          * to save room.
215                          */
216                         unsigned int origlen;
217                         struct sockaddr_ll ll;
218                 };
219         } sa;
220 };
221 
222 #define vio_le() virtio_legacy_is_little_endian()
223 
224 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
225 
226 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
227 #define GET_PBLOCK_DESC(x, bid) \
228         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
229 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
230         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
231 #define GET_NEXT_PRB_BLK_NUM(x) \
232         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
233         ((x)->kactive_blk_num+1) : 0)
234 
235 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
236 static void __fanout_link(struct sock *sk, struct packet_sock *po);
237 
238 static int packet_direct_xmit(struct sk_buff *skb)
239 {
240         return dev_direct_xmit(skb, packet_pick_tx_queue(skb));
241 }
242 
243 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
244 {
245         struct net_device *dev;
246 
247         rcu_read_lock();
248         dev = rcu_dereference(po->cached_dev);
249         if (likely(dev))
250                 dev_hold(dev);
251         rcu_read_unlock();
252 
253         return dev;
254 }
255 
256 static void packet_cached_dev_assign(struct packet_sock *po,
257                                      struct net_device *dev)
258 {
259         rcu_assign_pointer(po->cached_dev, dev);
260 }
261 
262 static void packet_cached_dev_reset(struct packet_sock *po)
263 {
264         RCU_INIT_POINTER(po->cached_dev, NULL);
265 }
266 
267 static bool packet_use_direct_xmit(const struct packet_sock *po)
268 {
269         return po->xmit == packet_direct_xmit;
270 }
271 
272 static u16 packet_pick_tx_queue(struct sk_buff *skb)
273 {
274         struct net_device *dev = skb->dev;
275         const struct net_device_ops *ops = dev->netdev_ops;
276         int cpu = raw_smp_processor_id();
277         u16 queue_index;
278 
279 #ifdef CONFIG_XPS
280         skb->sender_cpu = cpu + 1;
281 #endif
282         skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues);
283         if (ops->ndo_select_queue) {
284                 queue_index = ops->ndo_select_queue(dev, skb, NULL);
285                 queue_index = netdev_cap_txqueue(dev, queue_index);
286         } else {
287                 queue_index = netdev_pick_tx(dev, skb, NULL);
288         }
289 
290         return queue_index;
291 }
292 
293 /* __register_prot_hook must be invoked through register_prot_hook
294  * or from a context in which asynchronous accesses to the packet
295  * socket is not possible (packet_create()).
296  */
297 static void __register_prot_hook(struct sock *sk)
298 {
299         struct packet_sock *po = pkt_sk(sk);
300 
301         if (!po->running) {
302                 if (po->fanout)
303                         __fanout_link(sk, po);
304                 else
305                         dev_add_pack(&po->prot_hook);
306 
307                 sock_hold(sk);
308                 po->running = 1;
309         }
310 }
311 
312 static void register_prot_hook(struct sock *sk)
313 {
314         lockdep_assert_held_once(&pkt_sk(sk)->bind_lock);
315         __register_prot_hook(sk);
316 }
317 
318 /* If the sync parameter is true, we will temporarily drop
319  * the po->bind_lock and do a synchronize_net to make sure no
320  * asynchronous packet processing paths still refer to the elements
321  * of po->prot_hook.  If the sync parameter is false, it is the
322  * callers responsibility to take care of this.
323  */
324 static void __unregister_prot_hook(struct sock *sk, bool sync)
325 {
326         struct packet_sock *po = pkt_sk(sk);
327 
328         lockdep_assert_held_once(&po->bind_lock);
329 
330         po->running = 0;
331 
332         if (po->fanout)
333                 __fanout_unlink(sk, po);
334         else
335                 __dev_remove_pack(&po->prot_hook);
336 
337         __sock_put(sk);
338 
339         if (sync) {
340                 spin_unlock(&po->bind_lock);
341                 synchronize_net();
342                 spin_lock(&po->bind_lock);
343         }
344 }
345 
346 static void unregister_prot_hook(struct sock *sk, bool sync)
347 {
348         struct packet_sock *po = pkt_sk(sk);
349 
350         if (po->running)
351                 __unregister_prot_hook(sk, sync);
352 }
353 
354 static inline struct page * __pure pgv_to_page(void *addr)
355 {
356         if (is_vmalloc_addr(addr))
357                 return vmalloc_to_page(addr);
358         return virt_to_page(addr);
359 }
360 
361 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
362 {
363         union tpacket_uhdr h;
364 
365         h.raw = frame;
366         switch (po->tp_version) {
367         case TPACKET_V1:
368                 h.h1->tp_status = status;
369                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
370                 break;
371         case TPACKET_V2:
372                 h.h2->tp_status = status;
373                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
374                 break;
375         case TPACKET_V3:
376                 h.h3->tp_status = status;
377                 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
378                 break;
379         default:
380                 WARN(1, "TPACKET version not supported.\n");
381                 BUG();
382         }
383 
384         smp_wmb();
385 }
386 
387 static int __packet_get_status(const struct packet_sock *po, void *frame)
388 {
389         union tpacket_uhdr h;
390 
391         smp_rmb();
392 
393         h.raw = frame;
394         switch (po->tp_version) {
395         case TPACKET_V1:
396                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
397                 return h.h1->tp_status;
398         case TPACKET_V2:
399                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
400                 return h.h2->tp_status;
401         case TPACKET_V3:
402                 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
403                 return h.h3->tp_status;
404         default:
405                 WARN(1, "TPACKET version not supported.\n");
406                 BUG();
407                 return 0;
408         }
409 }
410 
411 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
412                                    unsigned int flags)
413 {
414         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
415 
416         if (shhwtstamps &&
417             (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
418             ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
419                 return TP_STATUS_TS_RAW_HARDWARE;
420 
421         if (ktime_to_timespec_cond(skb->tstamp, ts))
422                 return TP_STATUS_TS_SOFTWARE;
423 
424         return 0;
425 }
426 
427 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
428                                     struct sk_buff *skb)
429 {
430         union tpacket_uhdr h;
431         struct timespec ts;
432         __u32 ts_status;
433 
434         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
435                 return 0;
436 
437         h.raw = frame;
438         switch (po->tp_version) {
439         case TPACKET_V1:
440                 h.h1->tp_sec = ts.tv_sec;
441                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
442                 break;
443         case TPACKET_V2:
444                 h.h2->tp_sec = ts.tv_sec;
445                 h.h2->tp_nsec = ts.tv_nsec;
446                 break;
447         case TPACKET_V3:
448                 h.h3->tp_sec = ts.tv_sec;
449                 h.h3->tp_nsec = ts.tv_nsec;
450                 break;
451         default:
452                 WARN(1, "TPACKET version not supported.\n");
453                 BUG();
454         }
455 
456         /* one flush is safe, as both fields always lie on the same cacheline */
457         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
458         smp_wmb();
459 
460         return ts_status;
461 }
462 
463 static void *packet_lookup_frame(const struct packet_sock *po,
464                                  const struct packet_ring_buffer *rb,
465                                  unsigned int position,
466                                  int status)
467 {
468         unsigned int pg_vec_pos, frame_offset;
469         union tpacket_uhdr h;
470 
471         pg_vec_pos = position / rb->frames_per_block;
472         frame_offset = position % rb->frames_per_block;
473 
474         h.raw = rb->pg_vec[pg_vec_pos].buffer +
475                 (frame_offset * rb->frame_size);
476 
477         if (status != __packet_get_status(po, h.raw))
478                 return NULL;
479 
480         return h.raw;
481 }
482 
483 static void *packet_current_frame(struct packet_sock *po,
484                 struct packet_ring_buffer *rb,
485                 int status)
486 {
487         return packet_lookup_frame(po, rb, rb->head, status);
488 }
489 
490 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
491 {
492         del_timer_sync(&pkc->retire_blk_timer);
493 }
494 
495 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
496                 struct sk_buff_head *rb_queue)
497 {
498         struct tpacket_kbdq_core *pkc;
499 
500         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
501 
502         spin_lock_bh(&rb_queue->lock);
503         pkc->delete_blk_timer = 1;
504         spin_unlock_bh(&rb_queue->lock);
505 
506         prb_del_retire_blk_timer(pkc);
507 }
508 
509 static void prb_setup_retire_blk_timer(struct packet_sock *po)
510 {
511         struct tpacket_kbdq_core *pkc;
512 
513         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
514         timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
515                     0);
516         pkc->retire_blk_timer.expires = jiffies;
517 }
518 
519 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
520                                 int blk_size_in_bytes)
521 {
522         struct net_device *dev;
523         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
524         struct ethtool_link_ksettings ecmd;
525         int err;
526 
527         rtnl_lock();
528         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
529         if (unlikely(!dev)) {
530                 rtnl_unlock();
531                 return DEFAULT_PRB_RETIRE_TOV;
532         }
533         err = __ethtool_get_link_ksettings(dev, &ecmd);
534         rtnl_unlock();
535         if (!err) {
536                 /*
537                  * If the link speed is so slow you don't really
538                  * need to worry about perf anyways
539                  */
540                 if (ecmd.base.speed < SPEED_1000 ||
541                     ecmd.base.speed == SPEED_UNKNOWN) {
542                         return DEFAULT_PRB_RETIRE_TOV;
543                 } else {
544                         msec = 1;
545                         div = ecmd.base.speed / 1000;
546                 }
547         }
548 
549         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
550 
551         if (div)
552                 mbits /= div;
553 
554         tmo = mbits * msec;
555 
556         if (div)
557                 return tmo+1;
558         return tmo;
559 }
560 
561 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
562                         union tpacket_req_u *req_u)
563 {
564         p1->feature_req_word = req_u->req3.tp_feature_req_word;
565 }
566 
567 static void init_prb_bdqc(struct packet_sock *po,
568                         struct packet_ring_buffer *rb,
569                         struct pgv *pg_vec,
570                         union tpacket_req_u *req_u)
571 {
572         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
573         struct tpacket_block_desc *pbd;
574 
575         memset(p1, 0x0, sizeof(*p1));
576 
577         p1->knxt_seq_num = 1;
578         p1->pkbdq = pg_vec;
579         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
580         p1->pkblk_start = pg_vec[0].buffer;
581         p1->kblk_size = req_u->req3.tp_block_size;
582         p1->knum_blocks = req_u->req3.tp_block_nr;
583         p1->hdrlen = po->tp_hdrlen;
584         p1->version = po->tp_version;
585         p1->last_kactive_blk_num = 0;
586         po->stats.stats3.tp_freeze_q_cnt = 0;
587         if (req_u->req3.tp_retire_blk_tov)
588                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
589         else
590                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
591                                                 req_u->req3.tp_block_size);
592         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
593         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
594 
595         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
596         prb_init_ft_ops(p1, req_u);
597         prb_setup_retire_blk_timer(po);
598         prb_open_block(p1, pbd);
599 }
600 
601 /*  Do NOT update the last_blk_num first.
602  *  Assumes sk_buff_head lock is held.
603  */
604 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
605 {
606         mod_timer(&pkc->retire_blk_timer,
607                         jiffies + pkc->tov_in_jiffies);
608         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
609 }
610 
611 /*
612  * Timer logic:
613  * 1) We refresh the timer only when we open a block.
614  *    By doing this we don't waste cycles refreshing the timer
615  *        on packet-by-packet basis.
616  *
617  * With a 1MB block-size, on a 1Gbps line, it will take
618  * i) ~8 ms to fill a block + ii) memcpy etc.
619  * In this cut we are not accounting for the memcpy time.
620  *
621  * So, if the user sets the 'tmo' to 10ms then the timer
622  * will never fire while the block is still getting filled
623  * (which is what we want). However, the user could choose
624  * to close a block early and that's fine.
625  *
626  * But when the timer does fire, we check whether or not to refresh it.
627  * Since the tmo granularity is in msecs, it is not too expensive
628  * to refresh the timer, lets say every '8' msecs.
629  * Either the user can set the 'tmo' or we can derive it based on
630  * a) line-speed and b) block-size.
631  * prb_calc_retire_blk_tmo() calculates the tmo.
632  *
633  */
634 static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
635 {
636         struct packet_sock *po =
637                 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
638         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
639         unsigned int frozen;
640         struct tpacket_block_desc *pbd;
641 
642         spin_lock(&po->sk.sk_receive_queue.lock);
643 
644         frozen = prb_queue_frozen(pkc);
645         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
646 
647         if (unlikely(pkc->delete_blk_timer))
648                 goto out;
649 
650         /* We only need to plug the race when the block is partially filled.
651          * tpacket_rcv:
652          *              lock(); increment BLOCK_NUM_PKTS; unlock()
653          *              copy_bits() is in progress ...
654          *              timer fires on other cpu:
655          *              we can't retire the current block because copy_bits
656          *              is in progress.
657          *
658          */
659         if (BLOCK_NUM_PKTS(pbd)) {
660                 while (atomic_read(&pkc->blk_fill_in_prog)) {
661                         /* Waiting for skb_copy_bits to finish... */
662                         cpu_relax();
663                 }
664         }
665 
666         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
667                 if (!frozen) {
668                         if (!BLOCK_NUM_PKTS(pbd)) {
669                                 /* An empty block. Just refresh the timer. */
670                                 goto refresh_timer;
671                         }
672                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
673                         if (!prb_dispatch_next_block(pkc, po))
674                                 goto refresh_timer;
675                         else
676                                 goto out;
677                 } else {
678                         /* Case 1. Queue was frozen because user-space was
679                          *         lagging behind.
680                          */
681                         if (prb_curr_blk_in_use(pbd)) {
682                                 /*
683                                  * Ok, user-space is still behind.
684                                  * So just refresh the timer.
685                                  */
686                                 goto refresh_timer;
687                         } else {
688                                /* Case 2. queue was frozen,user-space caught up,
689                                 * now the link went idle && the timer fired.
690                                 * We don't have a block to close.So we open this
691                                 * block and restart the timer.
692                                 * opening a block thaws the queue,restarts timer
693                                 * Thawing/timer-refresh is a side effect.
694                                 */
695                                 prb_open_block(pkc, pbd);
696                                 goto out;
697                         }
698                 }
699         }
700 
701 refresh_timer:
702         _prb_refresh_rx_retire_blk_timer(pkc);
703 
704 out:
705         spin_unlock(&po->sk.sk_receive_queue.lock);
706 }
707 
708 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
709                 struct tpacket_block_desc *pbd1, __u32 status)
710 {
711         /* Flush everything minus the block header */
712 
713 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
714         u8 *start, *end;
715 
716         start = (u8 *)pbd1;
717 
718         /* Skip the block header(we know header WILL fit in 4K) */
719         start += PAGE_SIZE;
720 
721         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
722         for (; start < end; start += PAGE_SIZE)
723                 flush_dcache_page(pgv_to_page(start));
724 
725         smp_wmb();
726 #endif
727 
728         /* Now update the block status. */
729 
730         BLOCK_STATUS(pbd1) = status;
731 
732         /* Flush the block header */
733 
734 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
735         start = (u8 *)pbd1;
736         flush_dcache_page(pgv_to_page(start));
737 
738         smp_wmb();
739 #endif
740 }
741 
742 /*
743  * Side effect:
744  *
745  * 1) flush the block
746  * 2) Increment active_blk_num
747  *
748  * Note:We DONT refresh the timer on purpose.
749  *      Because almost always the next block will be opened.
750  */
751 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
752                 struct tpacket_block_desc *pbd1,
753                 struct packet_sock *po, unsigned int stat)
754 {
755         __u32 status = TP_STATUS_USER | stat;
756 
757         struct tpacket3_hdr *last_pkt;
758         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
759         struct sock *sk = &po->sk;
760 
761         if (atomic_read(&po->tp_drops))
762                 status |= TP_STATUS_LOSING;
763 
764         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
765         last_pkt->tp_next_offset = 0;
766 
767         /* Get the ts of the last pkt */
768         if (BLOCK_NUM_PKTS(pbd1)) {
769                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
770                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
771         } else {
772                 /* Ok, we tmo'd - so get the current time.
773                  *
774                  * It shouldn't really happen as we don't close empty
775                  * blocks. See prb_retire_rx_blk_timer_expired().
776                  */
777                 struct timespec ts;
778                 getnstimeofday(&ts);
779                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
780                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
781         }
782 
783         smp_wmb();
784 
785         /* Flush the block */
786         prb_flush_block(pkc1, pbd1, status);
787 
788         sk->sk_data_ready(sk);
789 
790         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
791 }
792 
793 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
794 {
795         pkc->reset_pending_on_curr_blk = 0;
796 }
797 
798 /*
799  * Side effect of opening a block:
800  *
801  * 1) prb_queue is thawed.
802  * 2) retire_blk_timer is refreshed.
803  *
804  */
805 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
806         struct tpacket_block_desc *pbd1)
807 {
808         struct timespec ts;
809         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
810 
811         smp_rmb();
812 
813         /* We could have just memset this but we will lose the
814          * flexibility of making the priv area sticky
815          */
816 
817         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
818         BLOCK_NUM_PKTS(pbd1) = 0;
819         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
820 
821         getnstimeofday(&ts);
822 
823         h1->ts_first_pkt.ts_sec = ts.tv_sec;
824         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
825 
826         pkc1->pkblk_start = (char *)pbd1;
827         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
828 
829         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
830         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
831 
832         pbd1->version = pkc1->version;
833         pkc1->prev = pkc1->nxt_offset;
834         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
835 
836         prb_thaw_queue(pkc1);
837         _prb_refresh_rx_retire_blk_timer(pkc1);
838 
839         smp_wmb();
840 }
841 
842 /*
843  * Queue freeze logic:
844  * 1) Assume tp_block_nr = 8 blocks.
845  * 2) At time 't0', user opens Rx ring.
846  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
847  * 4) user-space is either sleeping or processing block ''.
848  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
849  *    it will close block-7,loop around and try to fill block ''.
850  *    call-flow:
851  *    __packet_lookup_frame_in_block
852  *      prb_retire_current_block()
853  *      prb_dispatch_next_block()
854  *        |->(BLOCK_STATUS == USER) evaluates to true
855  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
856  * 6) Now there are two cases:
857  *    6.1) Link goes idle right after the queue is frozen.
858  *         But remember, the last open_block() refreshed the timer.
859  *         When this timer expires,it will refresh itself so that we can
860  *         re-open block-0 in near future.
861  *    6.2) Link is busy and keeps on receiving packets. This is a simple
862  *         case and __packet_lookup_frame_in_block will check if block-0
863  *         is free and can now be re-used.
864  */
865 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
866                                   struct packet_sock *po)
867 {
868         pkc->reset_pending_on_curr_blk = 1;
869         po->stats.stats3.tp_freeze_q_cnt++;
870 }
871 
872 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
873 
874 /*
875  * If the next block is free then we will dispatch it
876  * and return a good offset.
877  * Else, we will freeze the queue.
878  * So, caller must check the return value.
879  */
880 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
881                 struct packet_sock *po)
882 {
883         struct tpacket_block_desc *pbd;
884 
885         smp_rmb();
886 
887         /* 1. Get current block num */
888         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
889 
890         /* 2. If this block is currently in_use then freeze the queue */
891         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
892                 prb_freeze_queue(pkc, po);
893                 return NULL;
894         }
895 
896         /*
897          * 3.
898          * open this block and return the offset where the first packet
899          * needs to get stored.
900          */
901         prb_open_block(pkc, pbd);
902         return (void *)pkc->nxt_offset;
903 }
904 
905 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
906                 struct packet_sock *po, unsigned int status)
907 {
908         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
909 
910         /* retire/close the current block */
911         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
912                 /*
913                  * Plug the case where copy_bits() is in progress on
914                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
915                  * have space to copy the pkt in the current block and
916                  * called prb_retire_current_block()
917                  *
918                  * We don't need to worry about the TMO case because
919                  * the timer-handler already handled this case.
920                  */
921                 if (!(status & TP_STATUS_BLK_TMO)) {
922                         while (atomic_read(&pkc->blk_fill_in_prog)) {
923                                 /* Waiting for skb_copy_bits to finish... */
924                                 cpu_relax();
925                         }
926                 }
927                 prb_close_block(pkc, pbd, po, status);
928                 return;
929         }
930 }
931 
932 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
933 {
934         return TP_STATUS_USER & BLOCK_STATUS(pbd);
935 }
936 
937 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
938 {
939         return pkc->reset_pending_on_curr_blk;
940 }
941 
942 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
943 {
944         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
945         atomic_dec(&pkc->blk_fill_in_prog);
946 }
947 
948 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
949                         struct tpacket3_hdr *ppd)
950 {
951         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
952 }
953 
954 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
955                         struct tpacket3_hdr *ppd)
956 {
957         ppd->hv1.tp_rxhash = 0;
958 }
959 
960 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
961                         struct tpacket3_hdr *ppd)
962 {
963         if (skb_vlan_tag_present(pkc->skb)) {
964                 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
965                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
966                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
967         } else {
968                 ppd->hv1.tp_vlan_tci = 0;
969                 ppd->hv1.tp_vlan_tpid = 0;
970                 ppd->tp_status = TP_STATUS_AVAILABLE;
971         }
972 }
973 
974 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
975                         struct tpacket3_hdr *ppd)
976 {
977         ppd->hv1.tp_padding = 0;
978         prb_fill_vlan_info(pkc, ppd);
979 
980         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
981                 prb_fill_rxhash(pkc, ppd);
982         else
983                 prb_clear_rxhash(pkc, ppd);
984 }
985 
986 static void prb_fill_curr_block(char *curr,
987                                 struct tpacket_kbdq_core *pkc,
988                                 struct tpacket_block_desc *pbd,
989                                 unsigned int len)
990 {
991         struct tpacket3_hdr *ppd;
992 
993         ppd  = (struct tpacket3_hdr *)curr;
994         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
995         pkc->prev = curr;
996         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
997         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
998         BLOCK_NUM_PKTS(pbd) += 1;
999         atomic_inc(&pkc->blk_fill_in_prog);
1000         prb_run_all_ft_ops(pkc, ppd);
1001 }
1002 
1003 /* Assumes caller has the sk->rx_queue.lock */
1004 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1005                                             struct sk_buff *skb,
1006                                             unsigned int len
1007                                             )
1008 {
1009         struct tpacket_kbdq_core *pkc;
1010         struct tpacket_block_desc *pbd;
1011         char *curr, *end;
1012 
1013         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1014         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1015 
1016         /* Queue is frozen when user space is lagging behind */
1017         if (prb_queue_frozen(pkc)) {
1018                 /*
1019                  * Check if that last block which caused the queue to freeze,
1020                  * is still in_use by user-space.
1021                  */
1022                 if (prb_curr_blk_in_use(pbd)) {
1023                         /* Can't record this packet */
1024                         return NULL;
1025                 } else {
1026                         /*
1027                          * Ok, the block was released by user-space.
1028                          * Now let's open that block.
1029                          * opening a block also thaws the queue.
1030                          * Thawing is a side effect.
1031                          */
1032                         prb_open_block(pkc, pbd);
1033                 }
1034         }
1035 
1036         smp_mb();
1037         curr = pkc->nxt_offset;
1038         pkc->skb = skb;
1039         end = (char *)pbd + pkc->kblk_size;
1040 
1041         /* first try the current block */
1042         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1043                 prb_fill_curr_block(curr, pkc, pbd, len);
1044                 return (void *)curr;
1045         }
1046 
1047         /* Ok, close the current block */
1048         prb_retire_current_block(pkc, po, 0);
1049 
1050         /* Now, try to dispatch the next block */
1051         curr = (char *)prb_dispatch_next_block(pkc, po);
1052         if (curr) {
1053                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1054                 prb_fill_curr_block(curr, pkc, pbd, len);
1055                 return (void *)curr;
1056         }
1057 
1058         /*
1059          * No free blocks are available.user_space hasn't caught up yet.
1060          * Queue was just frozen and now this packet will get dropped.
1061          */
1062         return NULL;
1063 }
1064 
1065 static void *packet_current_rx_frame(struct packet_sock *po,
1066                                             struct sk_buff *skb,
1067                                             int status, unsigned int len)
1068 {
1069         char *curr = NULL;
1070         switch (po->tp_version) {
1071         case TPACKET_V1:
1072         case TPACKET_V2:
1073                 curr = packet_lookup_frame(po, &po->rx_ring,
1074                                         po->rx_ring.head, status);
1075                 return curr;
1076         case TPACKET_V3:
1077                 return __packet_lookup_frame_in_block(po, skb, len);
1078         default:
1079                 WARN(1, "TPACKET version not supported\n");
1080                 BUG();
1081                 return NULL;
1082         }
1083 }
1084 
1085 static void *prb_lookup_block(const struct packet_sock *po,
1086                               const struct packet_ring_buffer *rb,
1087                               unsigned int idx,
1088                               int status)
1089 {
1090         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1091         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1092 
1093         if (status != BLOCK_STATUS(pbd))
1094                 return NULL;
1095         return pbd;
1096 }
1097 
1098 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1099 {
1100         unsigned int prev;
1101         if (rb->prb_bdqc.kactive_blk_num)
1102                 prev = rb->prb_bdqc.kactive_blk_num-1;
1103         else
1104                 prev = rb->prb_bdqc.knum_blocks-1;
1105         return prev;
1106 }
1107 
1108 /* Assumes caller has held the rx_queue.lock */
1109 static void *__prb_previous_block(struct packet_sock *po,
1110                                          struct packet_ring_buffer *rb,
1111                                          int status)
1112 {
1113         unsigned int previous = prb_previous_blk_num(rb);
1114         return prb_lookup_block(po, rb, previous, status);
1115 }
1116 
1117 static void *packet_previous_rx_frame(struct packet_sock *po,
1118                                              struct packet_ring_buffer *rb,
1119                                              int status)
1120 {
1121         if (po->tp_version <= TPACKET_V2)
1122                 return packet_previous_frame(po, rb, status);
1123 
1124         return __prb_previous_block(po, rb, status);
1125 }
1126 
1127 static void packet_increment_rx_head(struct packet_sock *po,
1128                                             struct packet_ring_buffer *rb)
1129 {
1130         switch (po->tp_version) {
1131         case TPACKET_V1:
1132         case TPACKET_V2:
1133                 return packet_increment_head(rb);
1134         case TPACKET_V3:
1135         default:
1136                 WARN(1, "TPACKET version not supported.\n");
1137                 BUG();
1138                 return;
1139         }
1140 }
1141 
1142 static void *packet_previous_frame(struct packet_sock *po,
1143                 struct packet_ring_buffer *rb,
1144                 int status)
1145 {
1146         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1147         return packet_lookup_frame(po, rb, previous, status);
1148 }
1149 
1150 static void packet_increment_head(struct packet_ring_buffer *buff)
1151 {
1152         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1153 }
1154 
1155 static void packet_inc_pending(struct packet_ring_buffer *rb)
1156 {
1157         this_cpu_inc(*rb->pending_refcnt);
1158 }
1159 
1160 static void packet_dec_pending(struct packet_ring_buffer *rb)
1161 {
1162         this_cpu_dec(*rb->pending_refcnt);
1163 }
1164 
1165 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1166 {
1167         unsigned int refcnt = 0;
1168         int cpu;
1169 
1170         /* We don't use pending refcount in rx_ring. */
1171         if (rb->pending_refcnt == NULL)
1172                 return 0;
1173 
1174         for_each_possible_cpu(cpu)
1175                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1176 
1177         return refcnt;
1178 }
1179 
1180 static int packet_alloc_pending(struct packet_sock *po)
1181 {
1182         po->rx_ring.pending_refcnt = NULL;
1183 
1184         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1185         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1186                 return -ENOBUFS;
1187 
1188         return 0;
1189 }
1190 
1191 static void packet_free_pending(struct packet_sock *po)
1192 {
1193         free_percpu(po->tx_ring.pending_refcnt);
1194 }
1195 
1196 #define ROOM_POW_OFF    2
1197 #define ROOM_NONE       0x0
1198 #define ROOM_LOW        0x1
1199 #define ROOM_NORMAL     0x2
1200 
1201 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1202 {
1203         int idx, len;
1204 
1205         len = READ_ONCE(po->rx_ring.frame_max) + 1;
1206         idx = READ_ONCE(po->rx_ring.head);
1207         if (pow_off)
1208                 idx += len >> pow_off;
1209         if (idx >= len)
1210                 idx -= len;
1211         return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1212 }
1213 
1214 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1215 {
1216         int idx, len;
1217 
1218         len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1219         idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1220         if (pow_off)
1221                 idx += len >> pow_off;
1222         if (idx >= len)
1223                 idx -= len;
1224         return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1225 }
1226 
1227 static int __packet_rcv_has_room(const struct packet_sock *po,
1228                                  const struct sk_buff *skb)
1229 {
1230         const struct sock *sk = &po->sk;
1231         int ret = ROOM_NONE;
1232 
1233         if (po->prot_hook.func != tpacket_rcv) {
1234                 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1235                 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1236                                    - (skb ? skb->truesize : 0);
1237 
1238                 if (avail > (rcvbuf >> ROOM_POW_OFF))
1239                         return ROOM_NORMAL;
1240                 else if (avail > 0)
1241                         return ROOM_LOW;
1242                 else
1243                         return ROOM_NONE;
1244         }
1245 
1246         if (po->tp_version == TPACKET_V3) {
1247                 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1248                         ret = ROOM_NORMAL;
1249                 else if (__tpacket_v3_has_room(po, 0))
1250                         ret = ROOM_LOW;
1251         } else {
1252                 if (__tpacket_has_room(po, ROOM_POW_OFF))
1253                         ret = ROOM_NORMAL;
1254                 else if (__tpacket_has_room(po, 0))
1255                         ret = ROOM_LOW;
1256         }
1257 
1258         return ret;
1259 }
1260 
1261 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1262 {
1263         int pressure, ret;
1264 
1265         ret = __packet_rcv_has_room(po, skb);
1266         pressure = ret != ROOM_NORMAL;
1267 
1268         if (READ_ONCE(po->pressure) != pressure)
1269                 WRITE_ONCE(po->pressure, pressure);
1270 
1271         return ret;
1272 }
1273 
1274 static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1275 {
1276         if (READ_ONCE(po->pressure) &&
1277             __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1278                 WRITE_ONCE(po->pressure,  0);
1279 }
1280 
1281 static void packet_sock_destruct(struct sock *sk)
1282 {
1283         skb_queue_purge(&sk->sk_error_queue);
1284 
1285         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1286         WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1287 
1288         if (!sock_flag(sk, SOCK_DEAD)) {
1289                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1290                 return;
1291         }
1292 
1293         sk_refcnt_debug_dec(sk);
1294 }
1295 
1296 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1297 {
1298         u32 rxhash;
1299         int i, count = 0;
1300 
1301         rxhash = skb_get_hash(skb);
1302         for (i = 0; i < ROLLOVER_HLEN; i++)
1303                 if (po->rollover->history[i] == rxhash)
1304                         count++;
1305 
1306         po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1307         return count > (ROLLOVER_HLEN >> 1);
1308 }
1309 
1310 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1311                                       struct sk_buff *skb,
1312                                       unsigned int num)
1313 {
1314         return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1315 }
1316 
1317 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1318                                     struct sk_buff *skb,
1319                                     unsigned int num)
1320 {
1321         unsigned int val = atomic_inc_return(&f->rr_cur);
1322 
1323         return val % num;
1324 }
1325 
1326 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1327                                      struct sk_buff *skb,
1328                                      unsigned int num)
1329 {
1330         return smp_processor_id() % num;
1331 }
1332 
1333 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1334                                      struct sk_buff *skb,
1335                                      unsigned int num)
1336 {
1337         return prandom_u32_max(num);
1338 }
1339 
1340 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1341                                           struct sk_buff *skb,
1342                                           unsigned int idx, bool try_self,
1343                                           unsigned int num)
1344 {
1345         struct packet_sock *po, *po_next, *po_skip = NULL;
1346         unsigned int i, j, room = ROOM_NONE;
1347 
1348         po = pkt_sk(f->arr[idx]);
1349 
1350         if (try_self) {
1351                 room = packet_rcv_has_room(po, skb);
1352                 if (room == ROOM_NORMAL ||
1353                     (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1354                         return idx;
1355                 po_skip = po;
1356         }
1357 
1358         i = j = min_t(int, po->rollover->sock, num - 1);
1359         do {
1360                 po_next = pkt_sk(f->arr[i]);
1361                 if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
1362                     packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1363                         if (i != j)
1364                                 po->rollover->sock = i;
1365                         atomic_long_inc(&po->rollover->num);
1366                         if (room == ROOM_LOW)
1367                                 atomic_long_inc(&po->rollover->num_huge);
1368                         return i;
1369                 }
1370 
1371                 if (++i == num)
1372                         i = 0;
1373         } while (i != j);
1374 
1375         atomic_long_inc(&po->rollover->num_failed);
1376         return idx;
1377 }
1378 
1379 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1380                                     struct sk_buff *skb,
1381                                     unsigned int num)
1382 {
1383         return skb_get_queue_mapping(skb) % num;
1384 }
1385 
1386 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1387                                      struct sk_buff *skb,
1388                                      unsigned int num)
1389 {
1390         struct bpf_prog *prog;
1391         unsigned int ret = 0;
1392 
1393         rcu_read_lock();
1394         prog = rcu_dereference(f->bpf_prog);
1395         if (prog)
1396                 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1397         rcu_read_unlock();
1398 
1399         return ret;
1400 }
1401 
1402 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1403 {
1404         return f->flags & (flag >> 8);
1405 }
1406 
1407 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1408                              struct packet_type *pt, struct net_device *orig_dev)
1409 {
1410         struct packet_fanout *f = pt->af_packet_priv;
1411         unsigned int num = READ_ONCE(f->num_members);
1412         struct net *net = read_pnet(&f->net);
1413         struct packet_sock *po;
1414         unsigned int idx;
1415 
1416         if (!net_eq(dev_net(dev), net) || !num) {
1417                 kfree_skb(skb);
1418                 return 0;
1419         }
1420 
1421         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1422                 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1423                 if (!skb)
1424                         return 0;
1425         }
1426         switch (f->type) {
1427         case PACKET_FANOUT_HASH:
1428         default:
1429                 idx = fanout_demux_hash(f, skb, num);
1430                 break;
1431         case PACKET_FANOUT_LB:
1432                 idx = fanout_demux_lb(f, skb, num);
1433                 break;
1434         case PACKET_FANOUT_CPU:
1435                 idx = fanout_demux_cpu(f, skb, num);
1436                 break;
1437         case PACKET_FANOUT_RND:
1438                 idx = fanout_demux_rnd(f, skb, num);
1439                 break;
1440         case PACKET_FANOUT_QM:
1441                 idx = fanout_demux_qm(f, skb, num);
1442                 break;
1443         case PACKET_FANOUT_ROLLOVER:
1444                 idx = fanout_demux_rollover(f, skb, 0, false, num);
1445                 break;
1446         case PACKET_FANOUT_CBPF:
1447         case PACKET_FANOUT_EBPF:
1448                 idx = fanout_demux_bpf(f, skb, num);
1449                 break;
1450         }
1451 
1452         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1453                 idx = fanout_demux_rollover(f, skb, idx, true, num);
1454 
1455         po = pkt_sk(f->arr[idx]);
1456         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1457 }
1458 
1459 DEFINE_MUTEX(fanout_mutex);
1460 EXPORT_SYMBOL_GPL(fanout_mutex);
1461 static LIST_HEAD(fanout_list);
1462 static u16 fanout_next_id;
1463 
1464 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1465 {
1466         struct packet_fanout *f = po->fanout;
1467 
1468         spin_lock(&f->lock);
1469         f->arr[f->num_members] = sk;
1470         smp_wmb();
1471         f->num_members++;
1472         if (f->num_members == 1)
1473                 dev_add_pack(&f->prot_hook);
1474         spin_unlock(&f->lock);
1475 }
1476 
1477 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1478 {
1479         struct packet_fanout *f = po->fanout;
1480         int i;
1481 
1482         spin_lock(&f->lock);
1483         for (i = 0; i < f->num_members; i++) {
1484                 if (f->arr[i] == sk)
1485                         break;
1486         }
1487         BUG_ON(i >= f->num_members);
1488         f->arr[i] = f->arr[f->num_members - 1];
1489         f->num_members--;
1490         if (f->num_members == 0)
1491                 __dev_remove_pack(&f->prot_hook);
1492         spin_unlock(&f->lock);
1493 }
1494 
1495 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1496 {
1497         if (sk->sk_family != PF_PACKET)
1498                 return false;
1499 
1500         return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1501 }
1502 
1503 static void fanout_init_data(struct packet_fanout *f)
1504 {
1505         switch (f->type) {
1506         case PACKET_FANOUT_LB:
1507                 atomic_set(&f->rr_cur, 0);
1508                 break;
1509         case PACKET_FANOUT_CBPF:
1510         case PACKET_FANOUT_EBPF:
1511                 RCU_INIT_POINTER(f->bpf_prog, NULL);
1512                 break;
1513         }
1514 }
1515 
1516 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1517 {
1518         struct bpf_prog *old;
1519 
1520         spin_lock(&f->lock);
1521         old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1522         rcu_assign_pointer(f->bpf_prog, new);
1523         spin_unlock(&f->lock);
1524 
1525         if (old) {
1526                 synchronize_net();
1527                 bpf_prog_destroy(old);
1528         }
1529 }
1530 
1531 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1532                                 unsigned int len)
1533 {
1534         struct bpf_prog *new;
1535         struct sock_fprog fprog;
1536         int ret;
1537 
1538         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1539                 return -EPERM;
1540         if (len != sizeof(fprog))
1541                 return -EINVAL;
1542         if (copy_from_user(&fprog, data, len))
1543                 return -EFAULT;
1544 
1545         ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1546         if (ret)
1547                 return ret;
1548 
1549         __fanout_set_data_bpf(po->fanout, new);
1550         return 0;
1551 }
1552 
1553 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1554                                 unsigned int len)
1555 {
1556         struct bpf_prog *new;
1557         u32 fd;
1558 
1559         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1560                 return -EPERM;
1561         if (len != sizeof(fd))
1562                 return -EINVAL;
1563         if (copy_from_user(&fd, data, len))
1564                 return -EFAULT;
1565 
1566         new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1567         if (IS_ERR(new))
1568                 return PTR_ERR(new);
1569 
1570         __fanout_set_data_bpf(po->fanout, new);
1571         return 0;
1572 }
1573 
1574 static int fanout_set_data(struct packet_sock *po, char __user *data,
1575                            unsigned int len)
1576 {
1577         switch (po->fanout->type) {
1578         case PACKET_FANOUT_CBPF:
1579                 return fanout_set_data_cbpf(po, data, len);
1580         case PACKET_FANOUT_EBPF:
1581                 return fanout_set_data_ebpf(po, data, len);
1582         default:
1583                 return -EINVAL;
1584         }
1585 }
1586 
1587 static void fanout_release_data(struct packet_fanout *f)
1588 {
1589         switch (f->type) {
1590         case PACKET_FANOUT_CBPF:
1591         case PACKET_FANOUT_EBPF:
1592                 __fanout_set_data_bpf(f, NULL);
1593         }
1594 }
1595 
1596 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1597 {
1598         struct packet_fanout *f;
1599 
1600         list_for_each_entry(f, &fanout_list, list) {
1601                 if (f->id == candidate_id &&
1602                     read_pnet(&f->net) == sock_net(sk)) {
1603                         return false;
1604                 }
1605         }
1606         return true;
1607 }
1608 
1609 static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1610 {
1611         u16 id = fanout_next_id;
1612 
1613         do {
1614                 if (__fanout_id_is_free(sk, id)) {
1615                         *new_id = id;
1616                         fanout_next_id = id + 1;
1617                         return true;
1618                 }
1619 
1620                 id++;
1621         } while (id != fanout_next_id);
1622 
1623         return false;
1624 }
1625 
1626 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1627 {
1628         struct packet_rollover *rollover = NULL;
1629         struct packet_sock *po = pkt_sk(sk);
1630         struct packet_fanout *f, *match;
1631         u8 type = type_flags & 0xff;
1632         u8 flags = type_flags >> 8;
1633         int err;
1634 
1635         switch (type) {
1636         case PACKET_FANOUT_ROLLOVER:
1637                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1638                         return -EINVAL;
1639         case PACKET_FANOUT_HASH:
1640         case PACKET_FANOUT_LB:
1641         case PACKET_FANOUT_CPU:
1642         case PACKET_FANOUT_RND:
1643         case PACKET_FANOUT_QM:
1644         case PACKET_FANOUT_CBPF:
1645         case PACKET_FANOUT_EBPF:
1646                 break;
1647         default:
1648                 return -EINVAL;
1649         }
1650 
1651         mutex_lock(&fanout_mutex);
1652 
1653         err = -EALREADY;
1654         if (po->fanout)
1655                 goto out;
1656 
1657         if (type == PACKET_FANOUT_ROLLOVER ||
1658             (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1659                 err = -ENOMEM;
1660                 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1661                 if (!rollover)
1662                         goto out;
1663                 atomic_long_set(&rollover->num, 0);
1664                 atomic_long_set(&rollover->num_huge, 0);
1665                 atomic_long_set(&rollover->num_failed, 0);
1666         }
1667 
1668         if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1669                 if (id != 0) {
1670                         err = -EINVAL;
1671                         goto out;
1672                 }
1673                 if (!fanout_find_new_id(sk, &id)) {
1674                         err = -ENOMEM;
1675                         goto out;
1676                 }
1677                 /* ephemeral flag for the first socket in the group: drop it */
1678                 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1679         }
1680 
1681         match = NULL;
1682         list_for_each_entry(f, &fanout_list, list) {
1683                 if (f->id == id &&
1684                     read_pnet(&f->net) == sock_net(sk)) {
1685                         match = f;
1686                         break;
1687                 }
1688         }
1689         err = -EINVAL;
1690         if (match && match->flags != flags)
1691                 goto out;
1692         if (!match) {
1693                 err = -ENOMEM;
1694                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1695                 if (!match)
1696                         goto out;
1697                 write_pnet(&match->net, sock_net(sk));
1698                 match->id = id;
1699                 match->type = type;
1700                 match->flags = flags;
1701                 INIT_LIST_HEAD(&match->list);
1702                 spin_lock_init(&match->lock);
1703                 refcount_set(&match->sk_ref, 0);
1704                 fanout_init_data(match);
1705                 match->prot_hook.type = po->prot_hook.type;
1706                 match->prot_hook.dev = po->prot_hook.dev;
1707                 match->prot_hook.func = packet_rcv_fanout;
1708                 match->prot_hook.af_packet_priv = match;
1709                 match->prot_hook.id_match = match_fanout_group;
1710                 list_add(&match->list, &fanout_list);
1711         }
1712         err = -EINVAL;
1713 
1714         spin_lock(&po->bind_lock);
1715         if (po->running &&
1716             match->type == type &&
1717             match->prot_hook.type == po->prot_hook.type &&
1718             match->prot_hook.dev == po->prot_hook.dev) {
1719                 err = -ENOSPC;
1720                 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1721                         __dev_remove_pack(&po->prot_hook);
1722                         po->fanout = match;
1723                         po->rollover = rollover;
1724                         rollover = NULL;
1725                         refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1726                         __fanout_link(sk, po);
1727                         err = 0;
1728                 }
1729         }
1730         spin_unlock(&po->bind_lock);
1731 
1732         if (err && !refcount_read(&match->sk_ref)) {
1733                 list_del(&match->list);
1734                 kfree(match);
1735         }
1736 
1737 out:
1738         kfree(rollover);
1739         mutex_unlock(&fanout_mutex);
1740         return err;
1741 }
1742 
1743 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1744  * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1745  * It is the responsibility of the caller to call fanout_release_data() and
1746  * free the returned packet_fanout (after synchronize_net())
1747  */
1748 static struct packet_fanout *fanout_release(struct sock *sk)
1749 {
1750         struct packet_sock *po = pkt_sk(sk);
1751         struct packet_fanout *f;
1752 
1753         mutex_lock(&fanout_mutex);
1754         f = po->fanout;
1755         if (f) {
1756                 po->fanout = NULL;
1757 
1758                 if (refcount_dec_and_test(&f->sk_ref))
1759                         list_del(&f->list);
1760                 else
1761                         f = NULL;
1762         }
1763         mutex_unlock(&fanout_mutex);
1764 
1765         return f;
1766 }
1767 
1768 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1769                                           struct sk_buff *skb)
1770 {
1771         /* Earlier code assumed this would be a VLAN pkt, double-check
1772          * this now that we have the actual packet in hand. We can only
1773          * do this check on Ethernet devices.
1774          */
1775         if (unlikely(dev->type != ARPHRD_ETHER))
1776                 return false;
1777 
1778         skb_reset_mac_header(skb);
1779         return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1780 }
1781 
1782 static const struct proto_ops packet_ops;
1783 
1784 static const struct proto_ops packet_ops_spkt;
1785 
1786 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1787                            struct packet_type *pt, struct net_device *orig_dev)
1788 {
1789         struct sock *sk;
1790         struct sockaddr_pkt *spkt;
1791 
1792         /*
1793          *      When we registered the protocol we saved the socket in the data
1794          *      field for just this event.
1795          */
1796 
1797         sk = pt->af_packet_priv;
1798 
1799         /*
1800          *      Yank back the headers [hope the device set this
1801          *      right or kerboom...]
1802          *
1803          *      Incoming packets have ll header pulled,
1804          *      push it back.
1805          *
1806          *      For outgoing ones skb->data == skb_mac_header(skb)
1807          *      so that this procedure is noop.
1808          */
1809 
1810         if (skb->pkt_type == PACKET_LOOPBACK)
1811                 goto out;
1812 
1813         if (!net_eq(dev_net(dev), sock_net(sk)))
1814                 goto out;
1815 
1816         skb = skb_share_check(skb, GFP_ATOMIC);
1817         if (skb == NULL)
1818                 goto oom;
1819 
1820         /* drop any routing info */
1821         skb_dst_drop(skb);
1822 
1823         /* drop conntrack reference */
1824         nf_reset(skb);
1825 
1826         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1827 
1828         skb_push(skb, skb->data - skb_mac_header(skb));
1829 
1830         /*
1831          *      The SOCK_PACKET socket receives _all_ frames.
1832          */
1833 
1834         spkt->spkt_family = dev->type;
1835         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1836         spkt->spkt_protocol = skb->protocol;
1837 
1838         /*
1839          *      Charge the memory to the socket. This is done specifically
1840          *      to prevent sockets using all the memory up.
1841          */
1842 
1843         if (sock_queue_rcv_skb(sk, skb) == 0)
1844                 return 0;
1845 
1846 out:
1847         kfree_skb(skb);
1848 oom:
1849         return 0;
1850 }
1851 
1852 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1853 {
1854         if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1855             sock->type == SOCK_RAW) {
1856                 skb_reset_mac_header(skb);
1857                 skb->protocol = dev_parse_header_protocol(skb);
1858         }
1859 
1860         skb_probe_transport_header(skb);
1861 }
1862 
1863 /*
1864  *      Output a raw packet to a device layer. This bypasses all the other
1865  *      protocol layers and you must therefore supply it with a complete frame
1866  */
1867 
1868 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1869                                size_t len)
1870 {
1871         struct sock *sk = sock->sk;
1872         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1873         struct sk_buff *skb = NULL;
1874         struct net_device *dev;
1875         struct sockcm_cookie sockc;
1876         __be16 proto = 0;
1877         int err;
1878         int extra_len = 0;
1879 
1880         /*
1881          *      Get and verify the address.
1882          */
1883 
1884         if (saddr) {
1885                 if (msg->msg_namelen < sizeof(struct sockaddr))
1886                         return -EINVAL;
1887                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1888                         proto = saddr->spkt_protocol;
1889         } else
1890                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1891 
1892         /*
1893          *      Find the device first to size check it
1894          */
1895 
1896         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1897 retry:
1898         rcu_read_lock();
1899         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1900         err = -ENODEV;
1901         if (dev == NULL)
1902                 goto out_unlock;
1903 
1904         err = -ENETDOWN;
1905         if (!(dev->flags & IFF_UP))
1906                 goto out_unlock;
1907 
1908         /*
1909          * You may not queue a frame bigger than the mtu. This is the lowest level
1910          * raw protocol and you must do your own fragmentation at this level.
1911          */
1912 
1913         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1914                 if (!netif_supports_nofcs(dev)) {
1915                         err = -EPROTONOSUPPORT;
1916                         goto out_unlock;
1917                 }
1918                 extra_len = 4; /* We're doing our own CRC */
1919         }
1920 
1921         err = -EMSGSIZE;
1922         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1923                 goto out_unlock;
1924 
1925         if (!skb) {
1926                 size_t reserved = LL_RESERVED_SPACE(dev);
1927                 int tlen = dev->needed_tailroom;
1928                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1929 
1930                 rcu_read_unlock();
1931                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1932                 if (skb == NULL)
1933                         return -ENOBUFS;
1934                 /* FIXME: Save some space for broken drivers that write a hard
1935                  * header at transmission time by themselves. PPP is the notable
1936                  * one here. This should really be fixed at the driver level.
1937                  */
1938                 skb_reserve(skb, reserved);
1939                 skb_reset_network_header(skb);
1940 
1941                 /* Try to align data part correctly */
1942                 if (hhlen) {
1943                         skb->data -= hhlen;
1944                         skb->tail -= hhlen;
1945                         if (len < hhlen)
1946                                 skb_reset_network_header(skb);
1947                 }
1948                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1949                 if (err)
1950                         goto out_free;
1951                 goto retry;
1952         }
1953 
1954         if (!dev_validate_header(dev, skb->data, len)) {
1955                 err = -EINVAL;
1956                 goto out_unlock;
1957         }
1958         if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1959             !packet_extra_vlan_len_allowed(dev, skb)) {
1960                 err = -EMSGSIZE;
1961                 goto out_unlock;
1962         }
1963 
1964         sockcm_init(&sockc, sk);
1965         if (msg->msg_controllen) {
1966                 err = sock_cmsg_send(sk, msg, &sockc);
1967                 if (unlikely(err))
1968                         goto out_unlock;
1969         }
1970 
1971         skb->protocol = proto;
1972         skb->dev = dev;
1973         skb->priority = sk->sk_priority;
1974         skb->mark = sk->sk_mark;
1975         skb->tstamp = sockc.transmit_time;
1976 
1977         skb_setup_tx_timestamp(skb, sockc.tsflags);
1978 
1979         if (unlikely(extra_len == 4))
1980                 skb->no_fcs = 1;
1981 
1982         packet_parse_headers(skb, sock);
1983 
1984         dev_queue_xmit(skb);
1985         rcu_read_unlock();
1986         return len;
1987 
1988 out_unlock:
1989         rcu_read_unlock();
1990 out_free:
1991         kfree_skb(skb);
1992         return err;
1993 }
1994 
1995 static unsigned int run_filter(struct sk_buff *skb,
1996                                const struct sock *sk,
1997                                unsigned int res)
1998 {
1999         struct sk_filter *filter;
2000 
2001         rcu_read_lock();
2002         filter = rcu_dereference(sk->sk_filter);
2003         if (filter != NULL)
2004                 res = bpf_prog_run_clear_cb(filter->prog, skb);
2005         rcu_read_unlock();
2006 
2007         return res;
2008 }
2009 
2010 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2011                            size_t *len)
2012 {
2013         struct virtio_net_hdr vnet_hdr;
2014 
2015         if (*len < sizeof(vnet_hdr))
2016                 return -EINVAL;
2017         *len -= sizeof(vnet_hdr);
2018 
2019         if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2020                 return -EINVAL;
2021 
2022         return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2023 }
2024 
2025 /*
2026  * This function makes lazy skb cloning in hope that most of packets
2027  * are discarded by BPF.
2028  *
2029  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2030  * and skb->cb are mangled. It works because (and until) packets
2031  * falling here are owned by current CPU. Output packets are cloned
2032  * by dev_queue_xmit_nit(), input packets are processed by net_bh
2033  * sequencially, so that if we return skb to original state on exit,
2034  * we will not harm anyone.
2035  */
2036 
2037 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2038                       struct packet_type *pt, struct net_device *orig_dev)
2039 {
2040         struct sock *sk;
2041         struct sockaddr_ll *sll;
2042         struct packet_sock *po;
2043         u8 *skb_head = skb->data;
2044         int skb_len = skb->len;
2045         unsigned int snaplen, res;
2046         bool is_drop_n_account = false;
2047 
2048         if (skb->pkt_type == PACKET_LOOPBACK)
2049                 goto drop;
2050 
2051         sk = pt->af_packet_priv;
2052         po = pkt_sk(sk);
2053 
2054         if (!net_eq(dev_net(dev), sock_net(sk)))
2055                 goto drop;
2056 
2057         skb->dev = dev;
2058 
2059         if (dev->header_ops) {
2060                 /* The device has an explicit notion of ll header,
2061                  * exported to higher levels.
2062                  *
2063                  * Otherwise, the device hides details of its frame
2064                  * structure, so that corresponding packet head is
2065                  * never delivered to user.
2066                  */
2067                 if (sk->sk_type != SOCK_DGRAM)
2068                         skb_push(skb, skb->data - skb_mac_header(skb));
2069                 else if (skb->pkt_type == PACKET_OUTGOING) {
2070                         /* Special case: outgoing packets have ll header at head */
2071                         skb_pull(skb, skb_network_offset(skb));
2072                 }
2073         }
2074 
2075         snaplen = skb->len;
2076 
2077         res = run_filter(skb, sk, snaplen);
2078         if (!res)
2079                 goto drop_n_restore;
2080         if (snaplen > res)
2081                 snaplen = res;
2082 
2083         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2084                 goto drop_n_acct;
2085 
2086         if (skb_shared(skb)) {
2087                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2088                 if (nskb == NULL)
2089                         goto drop_n_acct;
2090 
2091                 if (skb_head != skb->data) {
2092                         skb->data = skb_head;
2093                         skb->len = skb_len;
2094                 }
2095                 consume_skb(skb);
2096                 skb = nskb;
2097         }
2098 
2099         sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2100 
2101         sll = &PACKET_SKB_CB(skb)->sa.ll;
2102         sll->sll_hatype = dev->type;
2103         sll->sll_pkttype = skb->pkt_type;
2104         if (unlikely(po->origdev))
2105                 sll->sll_ifindex = orig_dev->ifindex;
2106         else
2107                 sll->sll_ifindex = dev->ifindex;
2108 
2109         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2110 
2111         /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2112          * Use their space for storing the original skb length.
2113          */
2114         PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2115 
2116         if (pskb_trim(skb, snaplen))
2117                 goto drop_n_acct;
2118 
2119         skb_set_owner_r(skb, sk);
2120         skb->dev = NULL;
2121         skb_dst_drop(skb);
2122 
2123         /* drop conntrack reference */
2124         nf_reset(skb);
2125 
2126         spin_lock(&sk->sk_receive_queue.lock);
2127         po->stats.stats1.tp_packets++;
2128         sock_skb_set_dropcount(sk, skb);
2129         __skb_queue_tail(&sk->sk_receive_queue, skb);
2130         spin_unlock(&sk->sk_receive_queue.lock);
2131         sk->sk_data_ready(sk);
2132         return 0;
2133 
2134 drop_n_acct:
2135         is_drop_n_account = true;
2136         atomic_inc(&po->tp_drops);
2137         atomic_inc(&sk->sk_drops);
2138 
2139 drop_n_restore:
2140         if (skb_head != skb->data && skb_shared(skb)) {
2141                 skb->data = skb_head;
2142                 skb->len = skb_len;
2143         }
2144 drop:
2145         if (!is_drop_n_account)
2146                 consume_skb(skb);
2147         else
2148                 kfree_skb(skb);
2149         return 0;
2150 }
2151 
2152 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2153                        struct packet_type *pt, struct net_device *orig_dev)
2154 {
2155         struct sock *sk;
2156         struct packet_sock *po;
2157         struct sockaddr_ll *sll;
2158         union tpacket_uhdr h;
2159         u8 *skb_head = skb->data;
2160         int skb_len = skb->len;
2161         unsigned int snaplen, res;
2162         unsigned long status = TP_STATUS_USER;
2163         unsigned short macoff, netoff, hdrlen;
2164         struct sk_buff *copy_skb = NULL;
2165         struct timespec ts;
2166         __u32 ts_status;
2167         bool is_drop_n_account = false;
2168         bool do_vnet = false;
2169 
2170         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2171          * We may add members to them until current aligned size without forcing
2172          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2173          */
2174         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2175         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2176 
2177         if (skb->pkt_type == PACKET_LOOPBACK)
2178                 goto drop;
2179 
2180         sk = pt->af_packet_priv;
2181         po = pkt_sk(sk);
2182 
2183         if (!net_eq(dev_net(dev), sock_net(sk)))
2184                 goto drop;
2185 
2186         if (dev->header_ops) {
2187                 if (sk->sk_type != SOCK_DGRAM)
2188                         skb_push(skb, skb->data - skb_mac_header(skb));
2189                 else if (skb->pkt_type == PACKET_OUTGOING) {
2190                         /* Special case: outgoing packets have ll header at head */
2191                         skb_pull(skb, skb_network_offset(skb));
2192                 }
2193         }
2194 
2195         snaplen = skb->len;
2196 
2197         res = run_filter(skb, sk, snaplen);
2198         if (!res)
2199                 goto drop_n_restore;
2200 
2201         /* If we are flooded, just give up */
2202         if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2203                 atomic_inc(&po->tp_drops);
2204                 goto drop_n_restore;
2205         }
2206 
2207         if (skb->ip_summed == CHECKSUM_PARTIAL)
2208                 status |= TP_STATUS_CSUMNOTREADY;
2209         else if (skb->pkt_type != PACKET_OUTGOING &&
2210                  (skb->ip_summed == CHECKSUM_COMPLETE ||
2211                   skb_csum_unnecessary(skb)))
2212                 status |= TP_STATUS_CSUM_VALID;
2213 
2214         if (snaplen > res)
2215                 snaplen = res;
2216 
2217         if (sk->sk_type == SOCK_DGRAM) {
2218                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2219                                   po->tp_reserve;
2220         } else {
2221                 unsigned int maclen = skb_network_offset(skb);
2222                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2223                                        (maclen < 16 ? 16 : maclen)) +
2224                                        po->tp_reserve;
2225                 if (po->has_vnet_hdr) {
2226                         netoff += sizeof(struct virtio_net_hdr);
2227                         do_vnet = true;
2228                 }
2229                 macoff = netoff - maclen;
2230         }
2231         if (po->tp_version <= TPACKET_V2) {
2232                 if (macoff + snaplen > po->rx_ring.frame_size) {
2233                         if (po->copy_thresh &&
2234                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2235                                 if (skb_shared(skb)) {
2236                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
2237                                 } else {
2238                                         copy_skb = skb_get(skb);
2239                                         skb_head = skb->data;
2240                                 }
2241                                 if (copy_skb)
2242                                         skb_set_owner_r(copy_skb, sk);
2243                         }
2244                         snaplen = po->rx_ring.frame_size - macoff;
2245                         if ((int)snaplen < 0) {
2246                                 snaplen = 0;
2247                                 do_vnet = false;
2248                         }
2249                 }
2250         } else if (unlikely(macoff + snaplen >
2251                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2252                 u32 nval;
2253 
2254                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2255                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2256                             snaplen, nval, macoff);
2257                 snaplen = nval;
2258                 if (unlikely((int)snaplen < 0)) {
2259                         snaplen = 0;
2260                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2261                         do_vnet = false;
2262                 }
2263         }
2264         spin_lock(&sk->sk_receive_queue.lock);
2265         h.raw = packet_current_rx_frame(po, skb,
2266                                         TP_STATUS_KERNEL, (macoff+snaplen));
2267         if (!h.raw)
2268                 goto drop_n_account;
2269         if (po->tp_version <= TPACKET_V2) {
2270                 packet_increment_rx_head(po, &po->rx_ring);
2271         /*
2272          * LOSING will be reported till you read the stats,
2273          * because it's COR - Clear On Read.
2274          * Anyways, moving it for V1/V2 only as V3 doesn't need this
2275          * at packet level.
2276          */
2277                 if (atomic_read(&po->tp_drops))
2278                         status |= TP_STATUS_LOSING;
2279         }
2280 
2281         if (do_vnet &&
2282             virtio_net_hdr_from_skb(skb, h.raw + macoff -
2283                                     sizeof(struct virtio_net_hdr),
2284                                     vio_le(), true, 0))
2285                 goto drop_n_account;
2286 
2287         po->stats.stats1.tp_packets++;
2288         if (copy_skb) {
2289                 status |= TP_STATUS_COPY;
2290                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2291         }
2292         spin_unlock(&sk->sk_receive_queue.lock);
2293 
2294         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2295 
2296         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2297                 getnstimeofday(&ts);
2298 
2299         status |= ts_status;
2300 
2301         switch (po->tp_version) {
2302         case TPACKET_V1:
2303                 h.h1->tp_len = skb->len;
2304                 h.h1->tp_snaplen = snaplen;
2305                 h.h1->tp_mac = macoff;
2306                 h.h1->tp_net = netoff;
2307                 h.h1->tp_sec = ts.tv_sec;
2308                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2309                 hdrlen = sizeof(*h.h1);
2310                 break;
2311         case TPACKET_V2:
2312                 h.h2->tp_len = skb->len;
2313                 h.h2->tp_snaplen = snaplen;
2314                 h.h2->tp_mac = macoff;
2315                 h.h2->tp_net = netoff;
2316                 h.h2->tp_sec = ts.tv_sec;
2317                 h.h2->tp_nsec = ts.tv_nsec;
2318                 if (skb_vlan_tag_present(skb)) {
2319                         h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2320                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2321                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2322                 } else {
2323                         h.h2->tp_vlan_tci = 0;
2324                         h.h2->tp_vlan_tpid = 0;
2325                 }
2326                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2327                 hdrlen = sizeof(*h.h2);
2328                 break;
2329         case TPACKET_V3:
2330                 /* tp_nxt_offset,vlan are already populated above.
2331                  * So DONT clear those fields here
2332                  */
2333                 h.h3->tp_status |= status;
2334                 h.h3->tp_len = skb->len;
2335                 h.h3->tp_snaplen = snaplen;
2336                 h.h3->tp_mac = macoff;
2337                 h.h3->tp_net = netoff;
2338                 h.h3->tp_sec  = ts.tv_sec;
2339                 h.h3->tp_nsec = ts.tv_nsec;
2340                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2341                 hdrlen = sizeof(*h.h3);
2342                 break;
2343         default:
2344                 BUG();
2345         }
2346 
2347         sll = h.raw + TPACKET_ALIGN(hdrlen);
2348         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2349         sll->sll_family = AF_PACKET;
2350         sll->sll_hatype = dev->type;
2351         sll->sll_protocol = skb->protocol;
2352         sll->sll_pkttype = skb->pkt_type;
2353         if (unlikely(po->origdev))
2354                 sll->sll_ifindex = orig_dev->ifindex;
2355         else
2356                 sll->sll_ifindex = dev->ifindex;
2357 
2358         smp_mb();
2359 
2360 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2361         if (po->tp_version <= TPACKET_V2) {
2362                 u8 *start, *end;
2363 
2364                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2365                                         macoff + snaplen);
2366 
2367                 for (start = h.raw; start < end; start += PAGE_SIZE)
2368                         flush_dcache_page(pgv_to_page(start));
2369         }
2370         smp_wmb();
2371 #endif
2372 
2373         if (po->tp_version <= TPACKET_V2) {
2374                 __packet_set_status(po, h.raw, status);
2375                 sk->sk_data_ready(sk);
2376         } else {
2377                 prb_clear_blk_fill_status(&po->rx_ring);
2378         }
2379 
2380 drop_n_restore:
2381         if (skb_head != skb->data && skb_shared(skb)) {
2382                 skb->data = skb_head;
2383                 skb->len = skb_len;
2384         }
2385 drop:
2386         if (!is_drop_n_account)
2387                 consume_skb(skb);
2388         else
2389                 kfree_skb(skb);
2390         return 0;
2391 
2392 drop_n_account:
2393         spin_unlock(&sk->sk_receive_queue.lock);
2394         atomic_inc(&po->tp_drops);
2395         is_drop_n_account = true;
2396 
2397         sk->sk_data_ready(sk);
2398         kfree_skb(copy_skb);
2399         goto drop_n_restore;
2400 }
2401 
2402 static void tpacket_destruct_skb(struct sk_buff *skb)
2403 {
2404         struct packet_sock *po = pkt_sk(skb->sk);
2405 
2406         if (likely(po->tx_ring.pg_vec)) {
2407                 void *ph;
2408                 __u32 ts;
2409 
2410                 ph = skb_zcopy_get_nouarg(skb);
2411                 packet_dec_pending(&po->tx_ring);
2412 
2413                 ts = __packet_set_timestamp(po, ph, skb);
2414                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2415 
2416                 if (!packet_read_pending(&po->tx_ring))
2417                         complete(&po->skb_completion);
2418         }
2419 
2420         sock_wfree(skb);
2421 }
2422 
2423 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2424 {
2425         if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2426             (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2427              __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2428               __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2429                 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2430                          __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2431                         __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2432 
2433         if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2434                 return -EINVAL;
2435 
2436         return 0;
2437 }
2438 
2439 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2440                                  struct virtio_net_hdr *vnet_hdr)
2441 {
2442         if (*len < sizeof(*vnet_hdr))
2443                 return -EINVAL;
2444         *len -= sizeof(*vnet_hdr);
2445 
2446         if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2447                 return -EFAULT;
2448 
2449         return __packet_snd_vnet_parse(vnet_hdr, *len);
2450 }
2451 
2452 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2453                 void *frame, struct net_device *dev, void *data, int tp_len,
2454                 __be16 proto, unsigned char *addr, int hlen, int copylen,
2455                 const struct sockcm_cookie *sockc)
2456 {
2457         union tpacket_uhdr ph;
2458         int to_write, offset, len, nr_frags, len_max;
2459         struct socket *sock = po->sk.sk_socket;
2460         struct page *page;
2461         int err;
2462 
2463         ph.raw = frame;
2464 
2465         skb->protocol = proto;
2466         skb->dev = dev;
2467         skb->priority = po->sk.sk_priority;
2468         skb->mark = po->sk.sk_mark;
2469         skb->tstamp = sockc->transmit_time;
2470         skb_setup_tx_timestamp(skb, sockc->tsflags);
2471         skb_zcopy_set_nouarg(skb, ph.raw);
2472 
2473         skb_reserve(skb, hlen);
2474         skb_reset_network_header(skb);
2475 
2476         to_write = tp_len;
2477 
2478         if (sock->type == SOCK_DGRAM) {
2479                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2480                                 NULL, tp_len);
2481                 if (unlikely(err < 0))
2482                         return -EINVAL;
2483         } else if (copylen) {
2484                 int hdrlen = min_t(int, copylen, tp_len);
2485 
2486                 skb_push(skb, dev->hard_header_len);
2487                 skb_put(skb, copylen - dev->hard_header_len);
2488                 err = skb_store_bits(skb, 0, data, hdrlen);
2489                 if (unlikely(err))
2490                         return err;
2491                 if (!dev_validate_header(dev, skb->data, hdrlen))
2492                         return -EINVAL;
2493 
2494                 data += hdrlen;
2495                 to_write -= hdrlen;
2496         }
2497 
2498         offset = offset_in_page(data);
2499         len_max = PAGE_SIZE - offset;
2500         len = ((to_write > len_max) ? len_max : to_write);
2501 
2502         skb->data_len = to_write;
2503         skb->len += to_write;
2504         skb->truesize += to_write;
2505         refcount_add(to_write, &po->sk.sk_wmem_alloc);
2506 
2507         while (likely(to_write)) {
2508                 nr_frags = skb_shinfo(skb)->nr_frags;
2509 
2510                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2511                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2512                                MAX_SKB_FRAGS);
2513                         return -EFAULT;
2514                 }
2515 
2516                 page = pgv_to_page(data);
2517                 data += len;
2518                 flush_dcache_page(page);
2519                 get_page(page);
2520                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2521                 to_write -= len;
2522                 offset = 0;
2523                 len_max = PAGE_SIZE;
2524                 len = ((to_write > len_max) ? len_max : to_write);
2525         }
2526 
2527         packet_parse_headers(skb, sock);
2528 
2529         return tp_len;
2530 }
2531 
2532 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2533                                 int size_max, void **data)
2534 {
2535         union tpacket_uhdr ph;
2536         int tp_len, off;
2537 
2538         ph.raw = frame;
2539 
2540         switch (po->tp_version) {
2541         case TPACKET_V3:
2542                 if (ph.h3->tp_next_offset != 0) {
2543                         pr_warn_once("variable sized slot not supported");
2544                         return -EINVAL;
2545                 }
2546                 tp_len = ph.h3->tp_len;
2547                 break;
2548         case TPACKET_V2:
2549                 tp_len = ph.h2->tp_len;
2550                 break;
2551         default:
2552                 tp_len = ph.h1->tp_len;
2553                 break;
2554         }
2555         if (unlikely(tp_len > size_max)) {
2556                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2557                 return -EMSGSIZE;
2558         }
2559 
2560         if (unlikely(po->tp_tx_has_off)) {
2561                 int off_min, off_max;
2562 
2563                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2564                 off_max = po->tx_ring.frame_size - tp_len;
2565                 if (po->sk.sk_type == SOCK_DGRAM) {
2566                         switch (po->tp_version) {
2567                         case TPACKET_V3:
2568                                 off = ph.h3->tp_net;
2569                                 break;
2570                         case TPACKET_V2:
2571                                 off = ph.h2->tp_net;
2572                                 break;
2573                         default:
2574                                 off = ph.h1->tp_net;
2575                                 break;
2576                         }
2577                 } else {
2578                         switch (po->tp_version) {
2579                         case TPACKET_V3:
2580                                 off = ph.h3->tp_mac;
2581                                 break;
2582                         case TPACKET_V2:
2583                                 off = ph.h2->tp_mac;
2584                                 break;
2585                         default:
2586                                 off = ph.h1->tp_mac;
2587                                 break;
2588                         }
2589                 }
2590                 if (unlikely((off < off_min) || (off_max < off)))
2591                         return -EINVAL;
2592         } else {
2593                 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2594         }
2595 
2596         *data = frame + off;
2597         return tp_len;
2598 }
2599 
2600 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2601 {
2602         struct sk_buff *skb = NULL;
2603         struct net_device *dev;
2604         struct virtio_net_hdr *vnet_hdr = NULL;
2605         struct sockcm_cookie sockc;
2606         __be16 proto;
2607         int err, reserve = 0;
2608         void *ph;
2609         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2610         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2611         unsigned char *addr = NULL;
2612         int tp_len, size_max;
2613         void *data;
2614         int len_sum = 0;
2615         int status = TP_STATUS_AVAILABLE;
2616         int hlen, tlen, copylen = 0;
2617         long timeo = 0;
2618 
2619         mutex_lock(&po->pg_vec_lock);
2620 
2621         /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2622          * we need to confirm it under protection of pg_vec_lock.
2623          */
2624         if (unlikely(!po->tx_ring.pg_vec)) {
2625                 err = -EBUSY;
2626                 goto out;
2627         }
2628         if (likely(saddr == NULL)) {
2629                 dev     = packet_cached_dev_get(po);
2630                 proto   = po->num;
2631         } else {
2632                 err = -EINVAL;
2633                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2634                         goto out;
2635                 if (msg->msg_namelen < (saddr->sll_halen
2636                                         + offsetof(struct sockaddr_ll,
2637                                                 sll_addr)))
2638                         goto out;
2639                 proto   = saddr->sll_protocol;
2640                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2641                 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2642                         if (dev && msg->msg_namelen < dev->addr_len +
2643                                    offsetof(struct sockaddr_ll, sll_addr))
2644                                 goto out_put;
2645                         addr = saddr->sll_addr;
2646                 }
2647         }
2648 
2649         err = -ENXIO;
2650         if (unlikely(dev == NULL))
2651                 goto out;
2652         err = -ENETDOWN;
2653         if (unlikely(!(dev->flags & IFF_UP)))
2654                 goto out_put;
2655 
2656         sockcm_init(&sockc, &po->sk);
2657         if (msg->msg_controllen) {
2658                 err = sock_cmsg_send(&po->sk, msg, &sockc);
2659                 if (unlikely(err))
2660                         goto out_put;
2661         }
2662 
2663         if (po->sk.sk_socket->type == SOCK_RAW)
2664                 reserve = dev->hard_header_len;
2665         size_max = po->tx_ring.frame_size
2666                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2667 
2668         if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2669                 size_max = dev->mtu + reserve + VLAN_HLEN;
2670 
2671         reinit_completion(&po->skb_completion);
2672 
2673         do {
2674                 ph = packet_current_frame(po, &po->tx_ring,
2675                                           TP_STATUS_SEND_REQUEST);
2676                 if (unlikely(ph == NULL)) {
2677                         if (need_wait && skb) {
2678                                 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2679                                 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2680                                 if (timeo <= 0) {
2681                                         err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2682                                         goto out_put;
2683                                 }
2684                         }
2685                         /* check for additional frames */
2686                         continue;
2687                 }
2688 
2689                 skb = NULL;
2690                 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2691                 if (tp_len < 0)
2692                         goto tpacket_error;
2693 
2694                 status = TP_STATUS_SEND_REQUEST;
2695                 hlen = LL_RESERVED_SPACE(dev);
2696                 tlen = dev->needed_tailroom;
2697                 if (po->has_vnet_hdr) {
2698                         vnet_hdr = data;
2699                         data += sizeof(*vnet_hdr);
2700                         tp_len -= sizeof(*vnet_hdr);
2701                         if (tp_len < 0 ||
2702                             __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2703                                 tp_len = -EINVAL;
2704                                 goto tpacket_error;
2705                         }
2706                         copylen = __virtio16_to_cpu(vio_le(),
2707                                                     vnet_hdr->hdr_len);
2708                 }
2709                 copylen = max_t(int, copylen, dev->hard_header_len);
2710                 skb = sock_alloc_send_skb(&po->sk,
2711                                 hlen + tlen + sizeof(struct sockaddr_ll) +
2712                                 (copylen - dev->hard_header_len),
2713                                 !need_wait, &err);
2714 
2715                 if (unlikely(skb == NULL)) {
2716                         /* we assume the socket was initially writeable ... */
2717                         if (likely(len_sum > 0))
2718                                 err = len_sum;
2719                         goto out_status;
2720                 }
2721                 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2722                                           addr, hlen, copylen, &sockc);
2723                 if (likely(tp_len >= 0) &&
2724                     tp_len > dev->mtu + reserve &&
2725                     !po->has_vnet_hdr &&
2726                     !packet_extra_vlan_len_allowed(dev, skb))
2727                         tp_len = -EMSGSIZE;
2728 
2729                 if (unlikely(tp_len < 0)) {
2730 tpacket_error:
2731                         if (po->tp_loss) {
2732                                 __packet_set_status(po, ph,
2733                                                 TP_STATUS_AVAILABLE);
2734                                 packet_increment_head(&po->tx_ring);
2735                                 kfree_skb(skb);
2736                                 continue;
2737                         } else {
2738                                 status = TP_STATUS_WRONG_FORMAT;
2739                                 err = tp_len;
2740                                 goto out_status;
2741                         }
2742                 }
2743 
2744                 if (po->has_vnet_hdr) {
2745                         if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2746                                 tp_len = -EINVAL;
2747                                 goto tpacket_error;
2748                         }
2749                         virtio_net_hdr_set_proto(skb, vnet_hdr);
2750                 }
2751 
2752                 skb->destructor = tpacket_destruct_skb;
2753                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2754                 packet_inc_pending(&po->tx_ring);
2755 
2756                 status = TP_STATUS_SEND_REQUEST;
2757                 err = po->xmit(skb);
2758                 if (unlikely(err > 0)) {
2759                         err = net_xmit_errno(err);
2760                         if (err && __packet_get_status(po, ph) ==
2761                                    TP_STATUS_AVAILABLE) {
2762                                 /* skb was destructed already */
2763                                 skb = NULL;
2764                                 goto out_status;
2765                         }
2766                         /*
2767                          * skb was dropped but not destructed yet;
2768                          * let's treat it like congestion or err < 0
2769                          */
2770                         err = 0;
2771                 }
2772                 packet_increment_head(&po->tx_ring);
2773                 len_sum += tp_len;
2774         } while (likely((ph != NULL) ||
2775                 /* Note: packet_read_pending() might be slow if we have
2776                  * to call it as it's per_cpu variable, but in fast-path
2777                  * we already short-circuit the loop with the first
2778                  * condition, and luckily don't have to go that path
2779                  * anyway.
2780                  */
2781                  (need_wait && packet_read_pending(&po->tx_ring))));
2782 
2783         err = len_sum;
2784         goto out_put;
2785 
2786 out_status:
2787         __packet_set_status(po, ph, status);
2788         kfree_skb(skb);
2789 out_put:
2790         dev_put(dev);
2791 out:
2792         mutex_unlock(&po->pg_vec_lock);
2793         return err;
2794 }
2795 
2796 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2797                                         size_t reserve, size_t len,
2798                                         size_t linear, int noblock,
2799                                         int *err)
2800 {
2801         struct sk_buff *skb;
2802 
2803         /* Under a page?  Don't bother with paged skb. */
2804         if (prepad + len < PAGE_SIZE || !linear)
2805                 linear = len;
2806 
2807         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2808                                    err, 0);
2809         if (!skb)
2810                 return NULL;
2811 
2812         skb_reserve(skb, reserve);
2813         skb_put(skb, linear);
2814         skb->data_len = len - linear;
2815         skb->len += len - linear;
2816 
2817         return skb;
2818 }
2819 
2820 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2821 {
2822         struct sock *sk = sock->sk;
2823         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2824         struct sk_buff *skb;
2825         struct net_device *dev;
2826         __be16 proto;
2827         unsigned char *addr = NULL;
2828         int err, reserve = 0;
2829         struct sockcm_cookie sockc;
2830         struct virtio_net_hdr vnet_hdr = { 0 };
2831         int offset = 0;
2832         struct packet_sock *po = pkt_sk(sk);
2833         bool has_vnet_hdr = false;
2834         int hlen, tlen, linear;
2835         int extra_len = 0;
2836 
2837         /*
2838          *      Get and verify the address.
2839          */
2840 
2841         if (likely(saddr == NULL)) {
2842                 dev     = packet_cached_dev_get(po);
2843                 proto   = po->num;
2844         } else {
2845                 err = -EINVAL;
2846                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2847                         goto out;
2848                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2849                         goto out;
2850                 proto   = saddr->sll_protocol;
2851                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2852                 if (sock->type == SOCK_DGRAM) {
2853                         if (dev && msg->msg_namelen < dev->addr_len +
2854                                    offsetof(struct sockaddr_ll, sll_addr))
2855                                 goto out_unlock;
2856                         addr = saddr->sll_addr;
2857                 }
2858         }
2859 
2860         err = -ENXIO;
2861         if (unlikely(dev == NULL))
2862                 goto out_unlock;
2863         err = -ENETDOWN;
2864         if (unlikely(!(dev->flags & IFF_UP)))
2865                 goto out_unlock;
2866 
2867         sockcm_init(&sockc, sk);
2868         sockc.mark = sk->sk_mark;
2869         if (msg->msg_controllen) {
2870                 err = sock_cmsg_send(sk, msg, &sockc);
2871                 if (unlikely(err))
2872                         goto out_unlock;
2873         }
2874 
2875         if (sock->type == SOCK_RAW)
2876                 reserve = dev->hard_header_len;
2877         if (po->has_vnet_hdr) {
2878                 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2879                 if (err)
2880                         goto out_unlock;
2881                 has_vnet_hdr = true;
2882         }
2883 
2884         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2885                 if (!netif_supports_nofcs(dev)) {
2886                         err = -EPROTONOSUPPORT;
2887                         goto out_unlock;
2888                 }
2889                 extra_len = 4; /* We're doing our own CRC */
2890         }
2891 
2892         err = -EMSGSIZE;
2893         if (!vnet_hdr.gso_type &&
2894             (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2895                 goto out_unlock;
2896 
2897         err = -ENOBUFS;
2898         hlen = LL_RESERVED_SPACE(dev);
2899         tlen = dev->needed_tailroom;
2900         linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2901         linear = max(linear, min_t(int, len, dev->hard_header_len));
2902         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2903                                msg->msg_flags & MSG_DONTWAIT, &err);
2904         if (skb == NULL)
2905                 goto out_unlock;
2906 
2907         skb_reset_network_header(skb);
2908 
2909         err = -EINVAL;
2910         if (sock->type == SOCK_DGRAM) {
2911                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2912                 if (unlikely(offset < 0))
2913                         goto out_free;
2914         } else if (reserve) {
2915                 skb_reserve(skb, -reserve);
2916                 if (len < reserve + sizeof(struct ipv6hdr) &&
2917                     dev->min_header_len != dev->hard_header_len)
2918                         skb_reset_network_header(skb);
2919         }
2920 
2921         /* Returns -EFAULT on error */
2922         err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2923         if (err)
2924                 goto out_free;
2925 
2926         if (sock->type == SOCK_RAW &&
2927             !dev_validate_header(dev, skb->data, len)) {
2928                 err = -EINVAL;
2929                 goto out_free;
2930         }
2931 
2932         skb_setup_tx_timestamp(skb, sockc.tsflags);
2933 
2934         if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2935             !packet_extra_vlan_len_allowed(dev, skb)) {
2936                 err = -EMSGSIZE;
2937                 goto out_free;
2938         }
2939 
2940         skb->protocol = proto;
2941         skb->dev = dev;
2942         skb->priority = sk->sk_priority;
2943         skb->mark = sockc.mark;
2944         skb->tstamp = sockc.transmit_time;
2945 
2946         if (has_vnet_hdr) {
2947                 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2948                 if (err)
2949                         goto out_free;
2950                 len += sizeof(vnet_hdr);
2951                 virtio_net_hdr_set_proto(skb, &vnet_hdr);
2952         }
2953 
2954         packet_parse_headers(skb, sock);
2955 
2956         if (unlikely(extra_len == 4))
2957                 skb->no_fcs = 1;
2958 
2959         err = po->xmit(skb);
2960         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2961                 goto out_unlock;
2962 
2963         dev_put(dev);
2964 
2965         return len;
2966 
2967 out_free:
2968         kfree_skb(skb);
2969 out_unlock:
2970         if (dev)
2971                 dev_put(dev);
2972 out:
2973         return err;
2974 }
2975 
2976 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2977 {
2978         struct sock *sk = sock->sk;
2979         struct packet_sock *po = pkt_sk(sk);
2980 
2981         if (po->tx_ring.pg_vec)
2982                 return tpacket_snd(po, msg);
2983         else
2984                 return packet_snd(sock, msg, len);
2985 }
2986 
2987 /*
2988  *      Close a PACKET socket. This is fairly simple. We immediately go
2989  *      to 'closed' state and remove our protocol entry in the device list.
2990  */
2991 
2992 static int packet_release(struct socket *sock)
2993 {
2994         struct sock *sk = sock->sk;
2995         struct packet_sock *po;
2996         struct packet_fanout *f;
2997         struct net *net;
2998         union tpacket_req_u req_u;
2999 
3000         if (!sk)
3001                 return 0;
3002 
3003         net = sock_net(sk);
3004         po = pkt_sk(sk);
3005 
3006         mutex_lock(&net->packet.sklist_lock);
3007         sk_del_node_init_rcu(sk);
3008         mutex_unlock(&net->packet.sklist_lock);
3009 
3010         preempt_disable();
3011         sock_prot_inuse_add(net, sk->sk_prot, -1);
3012         preempt_enable();
3013 
3014         spin_lock(&po->bind_lock);
3015         unregister_prot_hook(sk, false);
3016         packet_cached_dev_reset(po);
3017 
3018         if (po->prot_hook.dev) {
3019                 dev_put(po->prot_hook.dev);
3020                 po->prot_hook.dev = NULL;
3021         }
3022         spin_unlock(&po->bind_lock);
3023 
3024         packet_flush_mclist(sk);
3025 
3026         lock_sock(sk);
3027         if (po->rx_ring.pg_vec) {
3028                 memset(&req_u, 0, sizeof(req_u));
3029                 packet_set_ring(sk, &req_u, 1, 0);
3030         }
3031 
3032         if (po->tx_ring.pg_vec) {
3033                 memset(&req_u, 0, sizeof(req_u));
3034                 packet_set_ring(sk, &req_u, 1, 1);
3035         }
3036         release_sock(sk);
3037 
3038         f = fanout_release(sk);
3039 
3040         synchronize_net();
3041 
3042         kfree(po->rollover);
3043         if (f) {
3044                 fanout_release_data(f);
3045                 kfree(f);
3046         }
3047         /*
3048          *      Now the socket is dead. No more input will appear.
3049          */
3050         sock_orphan(sk);
3051         sock->sk = NULL;
3052 
3053         /* Purge queues */
3054 
3055         skb_queue_purge(&sk->sk_receive_queue);
3056         packet_free_pending(po);
3057         sk_refcnt_debug_release(sk);
3058 
3059         sock_put(sk);
3060         return 0;
3061 }
3062 
3063 /*
3064  *      Attach a packet hook.
3065  */
3066 
3067 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3068                           __be16 proto)
3069 {
3070         struct packet_sock *po = pkt_sk(sk);
3071         struct net_device *dev_curr;
3072         __be16 proto_curr;
3073         bool need_rehook;
3074         struct net_device *dev = NULL;
3075         int ret = 0;
3076         bool unlisted = false;
3077 
3078         lock_sock(sk);
3079         spin_lock(&po->bind_lock);
3080         rcu_read_lock();
3081 
3082         if (po->fanout) {
3083                 ret = -EINVAL;
3084                 goto out_unlock;
3085         }
3086 
3087         if (name) {
3088                 dev = dev_get_by_name_rcu(sock_net(sk), name);
3089                 if (!dev) {
3090                         ret = -ENODEV;
3091                         goto out_unlock;
3092                 }
3093         } else if (ifindex) {
3094                 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3095                 if (!dev) {
3096                         ret = -ENODEV;
3097                         goto out_unlock;
3098                 }
3099         }
3100 
3101         if (dev)
3102                 dev_hold(dev);
3103 
3104         proto_curr = po->prot_hook.type;
3105         dev_curr = po->prot_hook.dev;
3106 
3107         need_rehook = proto_curr != proto || dev_curr != dev;
3108 
3109         if (need_rehook) {
3110                 if (po->running) {
3111                         rcu_read_unlock();
3112                         /* prevents packet_notifier() from calling
3113                          * register_prot_hook()
3114                          */
3115                         po->num = 0;
3116                         __unregister_prot_hook(sk, true);
3117                         rcu_read_lock();
3118                         dev_curr = po->prot_hook.dev;
3119                         if (dev)
3120                                 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3121                                                                  dev->ifindex);
3122                 }
3123 
3124                 BUG_ON(po->running);
3125                 po->num = proto;
3126                 po->prot_hook.type = proto;
3127 
3128                 if (unlikely(unlisted)) {
3129                         dev_put(dev);
3130                         po->prot_hook.dev = NULL;
3131                         po->ifindex = -1;
3132                         packet_cached_dev_reset(po);
3133                 } else {
3134                         po->prot_hook.dev = dev;
3135                         po->ifindex = dev ? dev->ifindex : 0;
3136                         packet_cached_dev_assign(po, dev);
3137                 }
3138         }
3139         if (dev_curr)
3140                 dev_put(dev_curr);
3141 
3142         if (proto == 0 || !need_rehook)
3143                 goto out_unlock;
3144 
3145         if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3146                 register_prot_hook(sk);
3147         } else {
3148                 sk->sk_err = ENETDOWN;
3149                 if (!sock_flag(sk, SOCK_DEAD))
3150                         sk->sk_error_report(sk);
3151         }
3152 
3153 out_unlock:
3154         rcu_read_unlock();
3155         spin_unlock(&po->bind_lock);
3156         release_sock(sk);
3157         return ret;
3158 }
3159 
3160 /*
3161  *      Bind a packet socket to a device
3162  */
3163 
3164 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3165                             int addr_len)
3166 {
3167         struct sock *sk = sock->sk;
3168         char name[sizeof(uaddr->sa_data) + 1];
3169 
3170         /*
3171          *      Check legality
3172          */
3173 
3174         if (addr_len != sizeof(struct sockaddr))
3175                 return -EINVAL;
3176         /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3177          * zero-terminated.
3178          */
3179         memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3180         name[sizeof(uaddr->sa_data)] = 0;
3181 
3182         return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3183 }
3184 
3185 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3186 {
3187         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3188         struct sock *sk = sock->sk;
3189 
3190         /*
3191          *      Check legality
3192          */
3193 
3194         if (addr_len < sizeof(struct sockaddr_ll))
3195                 return -EINVAL;
3196         if (sll->sll_family != AF_PACKET)
3197                 return -EINVAL;
3198 
3199         return packet_do_bind(sk, NULL, sll->sll_ifindex,
3200                               sll->sll_protocol ? : pkt_sk(sk)->num);
3201 }
3202 
3203 static struct proto packet_proto = {
3204         .name     = "PACKET",
3205         .owner    = THIS_MODULE,
3206         .obj_size = sizeof(struct packet_sock),
3207 };
3208 
3209 /*
3210  *      Create a packet of type SOCK_PACKET.
3211  */
3212 
3213 static int packet_create(struct net *net, struct socket *sock, int protocol,
3214                          int kern)
3215 {
3216         struct sock *sk;
3217         struct packet_sock *po;
3218         __be16 proto = (__force __be16)protocol; /* weird, but documented */
3219         int err;
3220 
3221         if (!ns_capable(net->user_ns, CAP_NET_RAW))
3222                 return -EPERM;
3223         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3224             sock->type != SOCK_PACKET)
3225                 return -ESOCKTNOSUPPORT;
3226 
3227         sock->state = SS_UNCONNECTED;
3228 
3229         err = -ENOBUFS;
3230         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3231         if (sk == NULL)
3232                 goto out;
3233 
3234         sock->ops = &packet_ops;
3235         if (sock->type == SOCK_PACKET)
3236                 sock->ops = &packet_ops_spkt;
3237 
3238         sock_init_data(sock, sk);
3239 
3240         po = pkt_sk(sk);
3241         init_completion(&po->skb_completion);
3242         sk->sk_family = PF_PACKET;
3243         po->num = proto;
3244         po->xmit = dev_queue_xmit;
3245 
3246         err = packet_alloc_pending(po);
3247         if (err)
3248                 goto out2;
3249 
3250         packet_cached_dev_reset(po);
3251 
3252         sk->sk_destruct = packet_sock_destruct;
3253         sk_refcnt_debug_inc(sk);
3254 
3255         /*
3256          *      Attach a protocol block
3257          */
3258 
3259         spin_lock_init(&po->bind_lock);
3260         mutex_init(&po->pg_vec_lock);
3261         po->rollover = NULL;
3262         po->prot_hook.func = packet_rcv;
3263 
3264         if (sock->type == SOCK_PACKET)
3265                 po->prot_hook.func = packet_rcv_spkt;
3266 
3267         po->prot_hook.af_packet_priv = sk;
3268 
3269         if (proto) {
3270                 po->prot_hook.type = proto;
3271                 __register_prot_hook(sk);
3272         }
3273 
3274         mutex_lock(&net->packet.sklist_lock);
3275         sk_add_node_tail_rcu(sk, &net->packet.sklist);
3276         mutex_unlock(&net->packet.sklist_lock);
3277 
3278         preempt_disable();
3279         sock_prot_inuse_add(net, &packet_proto, 1);
3280         preempt_enable();
3281 
3282         return 0;
3283 out2:
3284         sk_free(sk);
3285 out:
3286         return err;
3287 }
3288 
3289 /*
3290  *      Pull a packet from our receive queue and hand it to the user.
3291  *      If necessary we block.
3292  */
3293 
3294 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3295                           int flags)
3296 {
3297         struct sock *sk = sock->sk;
3298         struct sk_buff *skb;
3299         int copied, err;
3300         int vnet_hdr_len = 0;
3301         unsigned int origlen = 0;
3302 
3303         err = -EINVAL;
3304         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3305                 goto out;
3306 
3307 #if 0
3308         /* What error should we return now? EUNATTACH? */
3309         if (pkt_sk(sk)->ifindex < 0)
3310                 return -ENODEV;
3311 #endif
3312 
3313         if (flags & MSG_ERRQUEUE) {
3314                 err = sock_recv_errqueue(sk, msg, len,
3315                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
3316                 goto out;
3317         }
3318 
3319         /*
3320          *      Call the generic datagram receiver. This handles all sorts
3321          *      of horrible races and re-entrancy so we can forget about it
3322          *      in the protocol layers.
3323          *
3324          *      Now it will return ENETDOWN, if device have just gone down,
3325          *      but then it will block.
3326          */
3327 
3328         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3329 
3330         /*
3331          *      An error occurred so return it. Because skb_recv_datagram()
3332          *      handles the blocking we don't see and worry about blocking
3333          *      retries.
3334          */
3335 
3336         if (skb == NULL)
3337                 goto out;
3338 
3339         packet_rcv_try_clear_pressure(pkt_sk(sk));
3340 
3341         if (pkt_sk(sk)->has_vnet_hdr) {
3342                 err = packet_rcv_vnet(msg, skb, &len);
3343                 if (err)
3344                         goto out_free;
3345                 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3346         }
3347 
3348         /* You lose any data beyond the buffer you gave. If it worries
3349          * a user program they can ask the device for its MTU
3350          * anyway.
3351          */
3352         copied = skb->len;
3353         if (copied > len) {
3354                 copied = len;
3355                 msg->msg_flags |= MSG_TRUNC;
3356         }
3357 
3358         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3359         if (err)
3360                 goto out_free;
3361 
3362         if (sock->type != SOCK_PACKET) {
3363                 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3364 
3365                 /* Original length was stored in sockaddr_ll fields */
3366                 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3367                 sll->sll_family = AF_PACKET;
3368                 sll->sll_protocol = skb->protocol;
3369         }
3370 
3371         sock_recv_ts_and_drops(msg, sk, skb);
3372 
3373         if (msg->msg_name) {
3374                 int copy_len;
3375 
3376                 /* If the address length field is there to be filled
3377                  * in, we fill it in now.
3378                  */
3379                 if (sock->type == SOCK_PACKET) {
3380                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3381                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
3382                         copy_len = msg->msg_namelen;
3383                 } else {
3384                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3385 
3386                         msg->msg_namelen = sll->sll_halen +
3387                                 offsetof(struct sockaddr_ll, sll_addr);
3388                         copy_len = msg->msg_namelen;
3389                         if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3390                                 memset(msg->msg_name +
3391                                        offsetof(struct sockaddr_ll, sll_addr),
3392                                        0, sizeof(sll->sll_addr));
3393                                 msg->msg_namelen = sizeof(struct sockaddr_ll);
3394                         }
3395                 }
3396                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3397         }
3398 
3399         if (pkt_sk(sk)->auxdata) {
3400                 struct tpacket_auxdata aux;
3401 
3402                 aux.tp_status = TP_STATUS_USER;
3403                 if (skb->ip_summed == CHECKSUM_PARTIAL)
3404                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3405                 else if (skb->pkt_type != PACKET_OUTGOING &&
3406                          (skb->ip_summed == CHECKSUM_COMPLETE ||
3407                           skb_csum_unnecessary(skb)))
3408                         aux.tp_status |= TP_STATUS_CSUM_VALID;
3409 
3410                 aux.tp_len = origlen;
3411                 aux.tp_snaplen = skb->len;
3412                 aux.tp_mac = 0;
3413                 aux.tp_net = skb_network_offset(skb);
3414                 if (skb_vlan_tag_present(skb)) {
3415                         aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3416                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3417                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3418                 } else {
3419                         aux.tp_vlan_tci = 0;
3420                         aux.tp_vlan_tpid = 0;
3421                 }
3422                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3423         }
3424 
3425         /*
3426          *      Free or return the buffer as appropriate. Again this
3427          *      hides all the races and re-entrancy issues from us.
3428          */
3429         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3430 
3431 out_free:
3432         skb_free_datagram(sk, skb);
3433 out:
3434         return err;
3435 }
3436 
3437 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3438                                int peer)
3439 {
3440         struct net_device *dev;
3441         struct sock *sk = sock->sk;
3442 
3443         if (peer)
3444                 return -EOPNOTSUPP;
3445 
3446         uaddr->sa_family = AF_PACKET;
3447         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3448         rcu_read_lock();
3449         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3450         if (dev)
3451                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3452         rcu_read_unlock();
3453 
3454         return sizeof(*uaddr);
3455 }
3456 
3457 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3458                           int peer)
3459 {
3460         struct net_device *dev;
3461         struct sock *sk = sock->sk;
3462         struct packet_sock *po = pkt_sk(sk);
3463         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3464 
3465         if (peer)
3466                 return -EOPNOTSUPP;
3467 
3468         sll->sll_family = AF_PACKET;
3469         sll->sll_ifindex = po->ifindex;
3470         sll->sll_protocol = po->num;
3471         sll->sll_pkttype = 0;
3472         rcu_read_lock();
3473         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3474         if (dev) {
3475                 sll->sll_hatype = dev->type;
3476                 sll->sll_halen = dev->addr_len;
3477                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3478         } else {
3479                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3480                 sll->sll_halen = 0;
3481         }
3482         rcu_read_unlock();
3483 
3484         return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3485 }
3486 
3487 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3488                          int what)
3489 {
3490         switch (i->type) {
3491         case PACKET_MR_MULTICAST:
3492                 if (i->alen != dev->addr_len)
3493                         return -EINVAL;
3494                 if (what > 0)
3495                         return dev_mc_add(dev, i->addr);
3496                 else
3497                         return dev_mc_del(dev, i->addr);
3498                 break;
3499         case PACKET_MR_PROMISC:
3500                 return dev_set_promiscuity(dev, what);
3501         case PACKET_MR_ALLMULTI:
3502                 return dev_set_allmulti(dev, what);
3503         case PACKET_MR_UNICAST:
3504                 if (i->alen != dev->addr_len)
3505                         return -EINVAL;
3506                 if (what > 0)
3507                         return dev_uc_add(dev, i->addr);
3508                 else
3509                         return dev_uc_del(dev, i->addr);
3510                 break;
3511         default:
3512                 break;
3513         }
3514         return 0;
3515 }
3516 
3517 static void packet_dev_mclist_delete(struct net_device *dev,
3518                                      struct packet_mclist **mlp)
3519 {
3520         struct packet_mclist *ml;
3521 
3522         while ((ml = *mlp) != NULL) {
3523                 if (ml->ifindex == dev->ifindex) {
3524                         packet_dev_mc(dev, ml, -1);
3525                         *mlp = ml->next;
3526                         kfree(ml);
3527                 } else
3528                         mlp = &ml->next;
3529         }
3530 }
3531 
3532 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3533 {
3534         struct packet_sock *po = pkt_sk(sk);
3535         struct packet_mclist *ml, *i;
3536         struct net_device *dev;
3537         int err;
3538 
3539         rtnl_lock();
3540 
3541         err = -ENODEV;
3542         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3543         if (!dev)
3544                 goto done;
3545 
3546         err = -EINVAL;
3547         if (mreq->mr_alen > dev->addr_len)
3548                 goto done;
3549 
3550         err = -ENOBUFS;
3551         i = kmalloc(sizeof(*i), GFP_KERNEL);
3552         if (i == NULL)
3553                 goto done;
3554 
3555         err = 0;
3556         for (ml = po->mclist; ml; ml = ml->next) {
3557                 if (ml->ifindex == mreq->mr_ifindex &&
3558                     ml->type == mreq->mr_type &&
3559                     ml->alen == mreq->mr_alen &&
3560                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3561                         ml->count++;
3562                         /* Free the new element ... */
3563                         kfree(i);
3564                         goto done;
3565                 }
3566         }
3567 
3568         i->type = mreq->mr_type;
3569         i->ifindex = mreq->mr_ifindex;
3570         i->alen = mreq->mr_alen;
3571         memcpy(i->addr, mreq->mr_address, i->alen);
3572         memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3573         i->count = 1;
3574         i->next = po->mclist;
3575         po->mclist = i;
3576         err = packet_dev_mc(dev, i, 1);
3577         if (err) {
3578                 po->mclist = i->next;
3579                 kfree(i);
3580         }
3581 
3582 done:
3583         rtnl_unlock();
3584         return err;
3585 }
3586 
3587 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3588 {
3589         struct packet_mclist *ml, **mlp;
3590 
3591         rtnl_lock();
3592 
3593         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3594                 if (ml->ifindex == mreq->mr_ifindex &&
3595                     ml->type == mreq->mr_type &&
3596                     ml->alen == mreq->mr_alen &&
3597                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3598                         if (--ml->count == 0) {
3599                                 struct net_device *dev;
3600                                 *mlp = ml->next;
3601                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3602                                 if (dev)
3603                                         packet_dev_mc(dev, ml, -1);
3604                                 kfree(ml);
3605                         }
3606                         break;
3607                 }
3608         }
3609         rtnl_unlock();
3610         return 0;
3611 }
3612 
3613 static void packet_flush_mclist(struct sock *sk)
3614 {
3615         struct packet_sock *po = pkt_sk(sk);
3616         struct packet_mclist *ml;
3617 
3618         if (!po->mclist)
3619                 return;
3620 
3621         rtnl_lock();
3622         while ((ml = po->mclist) != NULL) {
3623                 struct net_device *dev;
3624 
3625                 po->mclist = ml->next;
3626                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3627                 if (dev != NULL)
3628                         packet_dev_mc(dev, ml, -1);
3629                 kfree(ml);
3630         }
3631         rtnl_unlock();
3632 }
3633 
3634 static int
3635 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3636 {
3637         struct sock *sk = sock->sk;
3638         struct packet_sock *po = pkt_sk(sk);
3639         int ret;
3640 
3641         if (level != SOL_PACKET)
3642                 return -ENOPROTOOPT;
3643 
3644         switch (optname) {
3645         case PACKET_ADD_MEMBERSHIP:
3646         case PACKET_DROP_MEMBERSHIP:
3647         {
3648                 struct packet_mreq_max mreq;
3649                 int len = optlen;
3650                 memset(&mreq, 0, sizeof(mreq));
3651                 if (len < sizeof(struct packet_mreq))
3652                         return -EINVAL;
3653                 if (len > sizeof(mreq))
3654                         len = sizeof(mreq);
3655                 if (copy_from_user(&mreq, optval, len))
3656                         return -EFAULT;
3657                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3658                         return -EINVAL;
3659                 if (optname == PACKET_ADD_MEMBERSHIP)
3660                         ret = packet_mc_add(sk, &mreq);
3661                 else
3662                         ret = packet_mc_drop(sk, &mreq);
3663                 return ret;
3664         }
3665 
3666         case PACKET_RX_RING:
3667         case PACKET_TX_RING:
3668         {
3669                 union tpacket_req_u req_u;
3670                 int len;
3671 
3672                 lock_sock(sk);
3673                 switch (po->tp_version) {
3674                 case TPACKET_V1:
3675                 case TPACKET_V2:
3676                         len = sizeof(req_u.req);
3677                         break;
3678                 case TPACKET_V3:
3679                 default:
3680                         len = sizeof(req_u.req3);
3681                         break;
3682                 }
3683                 if (optlen < len) {
3684                         ret = -EINVAL;
3685                 } else {
3686                         if (copy_from_user(&req_u.req, optval, len))
3687                                 ret = -EFAULT;
3688                         else
3689                                 ret = packet_set_ring(sk, &req_u, 0,
3690                                                     optname == PACKET_TX_RING);
3691                 }
3692                 release_sock(sk);
3693                 return ret;
3694         }
3695         case PACKET_COPY_THRESH:
3696         {
3697                 int val;
3698 
3699                 if (optlen != sizeof(val))
3700                         return -EINVAL;
3701                 if (copy_from_user(&val, optval, sizeof(val)))
3702                         return -EFAULT;
3703 
3704                 pkt_sk(sk)->copy_thresh = val;
3705                 return 0;
3706         }
3707         case PACKET_VERSION:
3708         {
3709                 int val;
3710 
3711                 if (optlen != sizeof(val))
3712                         return -EINVAL;
3713                 if (copy_from_user(&val, optval, sizeof(val)))
3714                         return -EFAULT;
3715                 switch (val) {
3716                 case TPACKET_V1:
3717                 case TPACKET_V2:
3718                 case TPACKET_V3:
3719                         break;
3720                 default:
3721                         return -EINVAL;
3722                 }
3723                 lock_sock(sk);
3724                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3725                         ret = -EBUSY;
3726                 } else {
3727                         po->tp_version = val;
3728                         ret = 0;
3729                 }
3730                 release_sock(sk);
3731                 return ret;
3732         }
3733         case PACKET_RESERVE:
3734         {
3735                 unsigned int val;
3736 
3737                 if (optlen != sizeof(val))
3738                         return -EINVAL;
3739                 if (copy_from_user(&val, optval, sizeof(val)))
3740                         return -EFAULT;
3741                 if (val > INT_MAX)
3742                         return -EINVAL;
3743                 lock_sock(sk);
3744                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3745                         ret = -EBUSY;
3746                 } else {
3747                         po->tp_reserve = val;
3748                         ret = 0;
3749                 }
3750                 release_sock(sk);
3751                 return ret;
3752         }
3753         case PACKET_LOSS:
3754         {
3755                 unsigned int val;
3756 
3757                 if (optlen != sizeof(val))
3758                         return -EINVAL;
3759                 if (copy_from_user(&val, optval, sizeof(val)))
3760                         return -EFAULT;
3761 
3762                 lock_sock(sk);
3763                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3764                         ret = -EBUSY;
3765                 } else {
3766                         po->tp_loss = !!val;
3767                         ret = 0;
3768                 }
3769                 release_sock(sk);
3770                 return ret;
3771         }
3772         case PACKET_AUXDATA:
3773         {
3774                 int val;
3775 
3776                 if (optlen < sizeof(val))
3777                         return -EINVAL;
3778                 if (copy_from_user(&val, optval, sizeof(val)))
3779                         return -EFAULT;
3780 
3781                 lock_sock(sk);
3782                 po->auxdata = !!val;
3783                 release_sock(sk);
3784                 return 0;
3785         }
3786         case PACKET_ORIGDEV:
3787         {
3788                 int val;
3789 
3790                 if (optlen < sizeof(val))
3791                         return -EINVAL;
3792                 if (copy_from_user(&val, optval, sizeof(val)))
3793                         return -EFAULT;
3794 
3795                 lock_sock(sk);
3796                 po->origdev = !!val;
3797                 release_sock(sk);
3798                 return 0;
3799         }
3800         case PACKET_VNET_HDR:
3801         {
3802                 int val;
3803 
3804                 if (sock->type != SOCK_RAW)
3805                         return -EINVAL;
3806                 if (optlen < sizeof(val))
3807                         return -EINVAL;
3808                 if (copy_from_user(&val, optval, sizeof(val)))
3809                         return -EFAULT;
3810 
3811                 lock_sock(sk);
3812                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3813                         ret = -EBUSY;
3814                 } else {
3815                         po->has_vnet_hdr = !!val;
3816                         ret = 0;
3817                 }
3818                 release_sock(sk);
3819                 return ret;
3820         }
3821         case PACKET_TIMESTAMP:
3822         {
3823                 int val;
3824 
3825                 if (optlen != sizeof(val))
3826                         return -EINVAL;
3827                 if (copy_from_user(&val, optval, sizeof(val)))
3828                         return -EFAULT;
3829 
3830                 po->tp_tstamp = val;
3831                 return 0;
3832         }
3833         case PACKET_FANOUT:
3834         {
3835                 int val;
3836 
3837                 if (optlen != sizeof(val))
3838                         return -EINVAL;
3839                 if (copy_from_user(&val, optval, sizeof(val)))
3840                         return -EFAULT;
3841 
3842                 return fanout_add(sk, val & 0xffff, val >> 16);
3843         }
3844         case PACKET_FANOUT_DATA:
3845         {
3846                 if (!po->fanout)
3847                         return -EINVAL;
3848 
3849                 return fanout_set_data(po, optval, optlen);
3850         }
3851         case PACKET_IGNORE_OUTGOING:
3852         {
3853                 int val;
3854 
3855                 if (optlen != sizeof(val))
3856                         return -EINVAL;
3857                 if (copy_from_user(&val, optval, sizeof(val)))
3858                         return -EFAULT;
3859                 if (val < 0 || val > 1)
3860                         return -EINVAL;
3861 
3862                 po->prot_hook.ignore_outgoing = !!val;
3863                 return 0;
3864         }
3865         case PACKET_TX_HAS_OFF:
3866         {
3867                 unsigned int val;
3868 
3869                 if (optlen != sizeof(val))
3870                         return -EINVAL;
3871                 if (copy_from_user(&val, optval, sizeof(val)))
3872                         return -EFAULT;
3873 
3874                 lock_sock(sk);
3875                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3876                         ret = -EBUSY;
3877                 } else {
3878                         po->tp_tx_has_off = !!val;
3879                         ret = 0;
3880                 }
3881                 release_sock(sk);
3882                 return 0;
3883         }
3884         case PACKET_QDISC_BYPASS:
3885         {
3886                 int val;
3887 
3888                 if (optlen != sizeof(val))
3889                         return -EINVAL;
3890                 if (copy_from_user(&val, optval, sizeof(val)))
3891                         return -EFAULT;
3892 
3893                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3894                 return 0;
3895         }
3896         default:
3897                 return -ENOPROTOOPT;
3898         }
3899 }
3900 
3901 static int packet_getsockopt(struct socket *sock, int level, int optname,
3902                              char __user *optval, int __user *optlen)
3903 {
3904         int len;
3905         int val, lv = sizeof(val);
3906         struct sock *sk = sock->sk;
3907         struct packet_sock *po = pkt_sk(sk);
3908         void *data = &val;
3909         union tpacket_stats_u st;
3910         struct tpacket_rollover_stats rstats;
3911         int drops;
3912 
3913         if (level != SOL_PACKET)
3914                 return -ENOPROTOOPT;
3915 
3916         if (get_user(len, optlen))
3917                 return -EFAULT;
3918 
3919         if (len < 0)
3920                 return -EINVAL;
3921 
3922         switch (optname) {
3923         case PACKET_STATISTICS:
3924                 spin_lock_bh(&sk->sk_receive_queue.lock);
3925                 memcpy(&st, &po->stats, sizeof(st));
3926                 memset(&po->stats, 0, sizeof(po->stats));
3927                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3928                 drops = atomic_xchg(&po->tp_drops, 0);
3929 
3930                 if (po->tp_version == TPACKET_V3) {
3931                         lv = sizeof(struct tpacket_stats_v3);
3932                         st.stats3.tp_drops = drops;
3933                         st.stats3.tp_packets += drops;
3934                         data = &st.stats3;
3935                 } else {
3936                         lv = sizeof(struct tpacket_stats);
3937                         st.stats1.tp_drops = drops;
3938                         st.stats1.tp_packets += drops;
3939                         data = &st.stats1;
3940                 }
3941 
3942                 break;
3943         case PACKET_AUXDATA:
3944                 val = po->auxdata;
3945                 break;
3946         case PACKET_ORIGDEV:
3947                 val = po->origdev;
3948                 break;
3949         case PACKET_VNET_HDR:
3950                 val = po->has_vnet_hdr;
3951                 break;
3952         case PACKET_VERSION:
3953                 val = po->tp_version;
3954                 break;
3955         case PACKET_HDRLEN:
3956                 if (len > sizeof(int))
3957                         len = sizeof(int);
3958                 if (len < sizeof(int))
3959                         return -EINVAL;
3960                 if (copy_from_user(&val, optval, len))
3961                         return -EFAULT;
3962                 switch (val) {
3963                 case TPACKET_V1:
3964                         val = sizeof(struct tpacket_hdr);
3965                         break;
3966                 case TPACKET_V2:
3967                         val = sizeof(struct tpacket2_hdr);
3968                         break;
3969                 case TPACKET_V3:
3970                         val = sizeof(struct tpacket3_hdr);
3971                         break;
3972                 default:
3973                         return -EINVAL;
3974                 }
3975                 break;
3976         case PACKET_RESERVE:
3977                 val = po->tp_reserve;
3978                 break;
3979         case PACKET_LOSS:
3980                 val = po->tp_loss;
3981                 break;
3982         case PACKET_TIMESTAMP:
3983                 val = po->tp_tstamp;
3984                 break;
3985         case PACKET_FANOUT:
3986                 val = (po->fanout ?
3987                        ((u32)po->fanout->id |
3988                         ((u32)po->fanout->type << 16) |
3989                         ((u32)po->fanout->flags << 24)) :
3990                        0);
3991                 break;
3992         case PACKET_IGNORE_OUTGOING:
3993                 val = po->prot_hook.ignore_outgoing;
3994                 break;
3995         case PACKET_ROLLOVER_STATS:
3996                 if (!po->rollover)
3997                         return -EINVAL;
3998                 rstats.tp_all = atomic_long_read(&po->rollover->num);
3999                 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4000                 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4001                 data = &rstats;
4002                 lv = sizeof(rstats);
4003                 break;
4004         case PACKET_TX_HAS_OFF:
4005                 val = po->tp_tx_has_off;
4006                 break;
4007         case PACKET_QDISC_BYPASS:
4008                 val = packet_use_direct_xmit(po);
4009                 break;
4010         default:
4011                 return -ENOPROTOOPT;
4012         }
4013 
4014         if (len > lv)
4015                 len = lv;
4016         if (put_user(len, optlen))
4017                 return -EFAULT;
4018         if (copy_to_user(optval, data, len))
4019                 return -EFAULT;
4020         return 0;
4021 }
4022 
4023 
4024 #ifdef CONFIG_COMPAT
4025 static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
4026                                     char __user *optval, unsigned int optlen)
4027 {
4028         struct packet_sock *po = pkt_sk(sock->sk);
4029 
4030         if (level != SOL_PACKET)
4031                 return -ENOPROTOOPT;
4032 
4033         if (optname == PACKET_FANOUT_DATA &&
4034             po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
4035                 optval = (char __user *)get_compat_bpf_fprog(optval);
4036                 if (!optval)
4037                         return -EFAULT;
4038                 optlen = sizeof(struct sock_fprog);
4039         }
4040 
4041         return packet_setsockopt(sock, level, optname, optval, optlen);
4042 }
4043 #endif
4044 
4045 static int packet_notifier(struct notifier_block *this,
4046                            unsigned long msg, void *ptr)
4047 {
4048         struct sock *sk;
4049         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4050         struct net *net = dev_net(dev);
4051 
4052         rcu_read_lock();
4053         sk_for_each_rcu(sk, &net->packet.sklist) {
4054                 struct packet_sock *po = pkt_sk(sk);
4055 
4056                 switch (msg) {
4057                 case NETDEV_UNREGISTER:
4058                         if (po->mclist)
4059                                 packet_dev_mclist_delete(dev, &po->mclist);
4060                         /* fallthrough */
4061 
4062                 case NETDEV_DOWN:
4063                         if (dev->ifindex == po->ifindex) {
4064                                 spin_lock(&po->bind_lock);
4065                                 if (po->running) {
4066                                         __unregister_prot_hook(sk, false);
4067                                         sk->sk_err = ENETDOWN;
4068                                         if (!sock_flag(sk, SOCK_DEAD))
4069                                                 sk->sk_error_report(sk);
4070                                 }
4071                                 if (msg == NETDEV_UNREGISTER) {
4072                                         packet_cached_dev_reset(po);
4073                                         po->ifindex = -1;
4074                                         if (po->prot_hook.dev)
4075                                                 dev_put(po->prot_hook.dev);
4076                                         po->prot_hook.dev = NULL;
4077                                 }
4078                                 spin_unlock(&po->bind_lock);
4079                         }
4080                         break;
4081                 case NETDEV_UP:
4082                         if (dev->ifindex == po->ifindex) {
4083                                 spin_lock(&po->bind_lock);
4084                                 if (po->num)
4085                                         register_prot_hook(sk);
4086                                 spin_unlock(&po->bind_lock);
4087                         }
4088                         break;
4089                 }
4090         }
4091         rcu_read_unlock();
4092         return NOTIFY_DONE;
4093 }
4094 
4095 
4096 static int packet_ioctl(struct socket *sock, unsigned int cmd,
4097                         unsigned long arg)
4098 {
4099         struct sock *sk = sock->sk;
4100 
4101         switch (cmd) {
4102         case SIOCOUTQ:
4103         {
4104                 int amount = sk_wmem_alloc_get(sk);
4105 
4106                 return put_user(amount, (int __user *)arg);
4107         }
4108         case SIOCINQ:
4109         {
4110                 struct sk_buff *skb;
4111                 int amount = 0;
4112 
4113                 spin_lock_bh(&sk->sk_receive_queue.lock);
4114                 skb = skb_peek(&sk->sk_receive_queue);
4115                 if (skb)
4116                         amount = skb->len;
4117                 spin_unlock_bh(&sk->sk_receive_queue.lock);
4118                 return put_user(amount, (int __user *)arg);
4119         }
4120 #ifdef CONFIG_INET
4121         case SIOCADDRT:
4122         case SIOCDELRT:
4123         case SIOCDARP:
4124         case SIOCGARP:
4125         case SIOCSARP:
4126         case SIOCGIFADDR:
4127         case SIOCSIFADDR:
4128         case SIOCGIFBRDADDR:
4129         case SIOCSIFBRDADDR:
4130         case SIOCGIFNETMASK:
4131         case SIOCSIFNETMASK:
4132         case SIOCGIFDSTADDR:
4133         case SIOCSIFDSTADDR:
4134         case SIOCSIFFLAGS:
4135                 return inet_dgram_ops.ioctl(sock, cmd, arg);
4136 #endif
4137 
4138         default:
4139                 return -ENOIOCTLCMD;
4140         }
4141         return 0;
4142 }
4143 
4144 static __poll_t packet_poll(struct file *file, struct socket *sock,
4145                                 poll_table *wait)
4146 {
4147         struct sock *sk = sock->sk;
4148         struct packet_sock *po = pkt_sk(sk);
4149         __poll_t mask = datagram_poll(file, sock, wait);
4150 
4151         spin_lock_bh(&sk->sk_receive_queue.lock);
4152         if (po->rx_ring.pg_vec) {
4153                 if (!packet_previous_rx_frame(po, &po->rx_ring,
4154                         TP_STATUS_KERNEL))
4155                         mask |= EPOLLIN | EPOLLRDNORM;
4156         }
4157         packet_rcv_try_clear_pressure(po);
4158         spin_unlock_bh(&sk->sk_receive_queue.lock);
4159         spin_lock_bh(&sk->sk_write_queue.lock);
4160         if (po->tx_ring.pg_vec) {
4161                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4162                         mask |= EPOLLOUT | EPOLLWRNORM;
4163         }
4164         spin_unlock_bh(&sk->sk_write_queue.lock);
4165         return mask;
4166 }
4167 
4168 
4169 /* Dirty? Well, I still did not learn better way to account
4170  * for user mmaps.
4171  */
4172 
4173 static void packet_mm_open(struct vm_area_struct *vma)
4174 {
4175         struct file *file = vma->vm_file;
4176         struct socket *sock = file->private_data;
4177         struct sock *sk = sock->sk;
4178 
4179         if (sk)
4180                 atomic_inc(&pkt_sk(sk)->mapped);
4181 }
4182 
4183 static void packet_mm_close(struct vm_area_struct *vma)
4184 {
4185         struct file *file = vma->vm_file;
4186         struct socket *sock = file->private_data;
4187         struct sock *sk = sock->sk;
4188 
4189         if (sk)
4190                 atomic_dec(&pkt_sk(sk)->mapped);
4191 }
4192 
4193 static const struct vm_operations_struct packet_mmap_ops = {
4194         .open   =       packet_mm_open,
4195         .close  =       packet_mm_close,
4196 };
4197 
4198 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4199                         unsigned int len)
4200 {
4201         int i;
4202 
4203         for (i = 0; i < len; i++) {
4204                 if (likely(pg_vec[i].buffer)) {
4205                         if (is_vmalloc_addr(pg_vec[i].buffer))
4206                                 vfree(pg_vec[i].buffer);
4207                         else
4208                                 free_pages((unsigned long)pg_vec[i].buffer,
4209                                            order);
4210                         pg_vec[i].buffer = NULL;
4211                 }
4212         }
4213         kfree(pg_vec);
4214 }
4215 
4216 static char *alloc_one_pg_vec_page(unsigned long order)
4217 {
4218         char *buffer;
4219         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4220                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4221 
4222         buffer = (char *) __get_free_pages(gfp_flags, order);
4223         if (buffer)
4224                 return buffer;
4225 
4226         /* __get_free_pages failed, fall back to vmalloc */
4227         buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4228         if (buffer)
4229                 return buffer;
4230 
4231         /* vmalloc failed, lets dig into swap here */
4232         gfp_flags &= ~__GFP_NORETRY;
4233         buffer = (char *) __get_free_pages(gfp_flags, order);
4234         if (buffer)
4235                 return buffer;
4236 
4237         /* complete and utter failure */
4238         return NULL;
4239 }
4240 
4241 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4242 {
4243         unsigned int block_nr = req->tp_block_nr;
4244         struct pgv *pg_vec;
4245         int i;
4246 
4247         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4248         if (unlikely(!pg_vec))
4249                 goto out;
4250 
4251         for (i = 0; i < block_nr; i++) {
4252                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4253                 if (unlikely(!pg_vec[i].buffer))
4254                         goto out_free_pgvec;
4255         }
4256 
4257 out:
4258         return pg_vec;
4259 
4260 out_free_pgvec:
4261         free_pg_vec(pg_vec, order, block_nr);
4262         pg_vec = NULL;
4263         goto out;
4264 }
4265 
4266 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4267                 int closing, int tx_ring)
4268 {
4269         struct pgv *pg_vec = NULL;
4270         struct packet_sock *po = pkt_sk(sk);
4271         int was_running, order = 0;
4272         struct packet_ring_buffer *rb;
4273         struct sk_buff_head *rb_queue;
4274         __be16 num;
4275         int err = -EINVAL;
4276         /* Added to avoid minimal code churn */
4277         struct tpacket_req *req = &req_u->req;
4278 
4279         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4280         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4281 
4282         err = -EBUSY;
4283         if (!closing) {
4284                 if (atomic_read(&po->mapped))
4285                         goto out;
4286                 if (packet_read_pending(rb))
4287                         goto out;
4288         }
4289 
4290         if (req->tp_block_nr) {
4291                 unsigned int min_frame_size;
4292 
4293                 /* Sanity tests and some calculations */
4294                 err = -EBUSY;
4295                 if (unlikely(rb->pg_vec))
4296                         goto out;
4297 
4298                 switch (po->tp_version) {
4299                 case TPACKET_V1:
4300                         po->tp_hdrlen = TPACKET_HDRLEN;
4301                         break;
4302                 case TPACKET_V2:
4303                         po->tp_hdrlen = TPACKET2_HDRLEN;
4304                         break;
4305                 case TPACKET_V3:
4306                         po->tp_hdrlen = TPACKET3_HDRLEN;
4307                         break;
4308                 }
4309 
4310                 err = -EINVAL;
4311                 if (unlikely((int)req->tp_block_size <= 0))
4312                         goto out;
4313                 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4314                         goto out;
4315                 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4316                 if (po->tp_version >= TPACKET_V3 &&
4317                     req->tp_block_size <
4318                     BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4319                         goto out;
4320                 if (unlikely(req->tp_frame_size < min_frame_size))
4321                         goto out;
4322                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4323                         goto out;
4324 
4325                 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4326                 if (unlikely(rb->frames_per_block == 0))
4327                         goto out;
4328                 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4329                         goto out;
4330                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4331                                         req->tp_frame_nr))
4332                         goto out;
4333 
4334                 err = -ENOMEM;
4335                 order = get_order(req->tp_block_size);
4336                 pg_vec = alloc_pg_vec(req, order);
4337                 if (unlikely(!pg_vec))
4338                         goto out;
4339                 switch (po->tp_version) {
4340                 case TPACKET_V3:
4341                         /* Block transmit is not supported yet */
4342                         if (!tx_ring) {
4343                                 init_prb_bdqc(po, rb, pg_vec, req_u);
4344                         } else {
4345                                 struct tpacket_req3 *req3 = &req_u->req3;
4346 
4347                                 if (req3->tp_retire_blk_tov ||
4348                                     req3->tp_sizeof_priv ||
4349                                     req3->tp_feature_req_word) {
4350                                         err = -EINVAL;
4351                                         goto out_free_pg_vec;
4352                                 }
4353                         }
4354                         break;
4355                 default:
4356                         break;
4357                 }
4358         }
4359         /* Done */
4360         else {
4361                 err = -EINVAL;
4362                 if (unlikely(req->tp_frame_nr))
4363                         goto out;
4364         }
4365 
4366 
4367         /* Detach socket from network */
4368         spin_lock(&po->bind_lock);
4369         was_running = po->running;
4370         num = po->num;
4371         if (was_running) {
4372                 po->num = 0;
4373                 __unregister_prot_hook(sk, false);
4374         }
4375         spin_unlock(&po->bind_lock);
4376 
4377         synchronize_net();
4378 
4379         err = -EBUSY;
4380         mutex_lock(&po->pg_vec_lock);
4381         if (closing || atomic_read(&po->mapped) == 0) {
4382                 err = 0;
4383                 spin_lock_bh(&rb_queue->lock);
4384                 swap(rb->pg_vec, pg_vec);
4385                 rb->frame_max = (req->tp_frame_nr - 1);
4386                 rb->head = 0;
4387                 rb->frame_size = req->tp_frame_size;
4388                 spin_unlock_bh(&rb_queue->lock);
4389 
4390                 swap(rb->pg_vec_order, order);
4391                 swap(rb->pg_vec_len, req->tp_block_nr);
4392 
4393                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4394                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4395                                                 tpacket_rcv : packet_rcv;
4396                 skb_queue_purge(rb_queue);
4397                 if (atomic_read(&po->mapped))
4398                         pr_err("packet_mmap: vma is busy: %d\n",
4399                                atomic_read(&po->mapped));
4400         }
4401         mutex_unlock(&po->pg_vec_lock);
4402 
4403         spin_lock(&po->bind_lock);
4404         if (was_running) {
4405                 po->num = num;
4406                 register_prot_hook(sk);
4407         }
4408         spin_unlock(&po->bind_lock);
4409         if (pg_vec && (po->tp_version > TPACKET_V2)) {
4410                 /* Because we don't support block-based V3 on tx-ring */
4411                 if (!tx_ring)
4412                         prb_shutdown_retire_blk_timer(po, rb_queue);
4413         }
4414 
4415 out_free_pg_vec:
4416         if (pg_vec)
4417                 free_pg_vec(pg_vec, order, req->tp_block_nr);
4418 out:
4419         return err;
4420 }
4421 
4422 static int packet_mmap(struct file *file, struct socket *sock,
4423                 struct vm_area_struct *vma)
4424 {
4425         struct sock *sk = sock->sk;
4426         struct packet_sock *po = pkt_sk(sk);
4427         unsigned long size, expected_size;
4428         struct packet_ring_buffer *rb;
4429         unsigned long start;
4430         int err = -EINVAL;
4431         int i;
4432 
4433         if (vma->vm_pgoff)
4434                 return -EINVAL;
4435 
4436         mutex_lock(&po->pg_vec_lock);
4437 
4438         expected_size = 0;
4439         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4440                 if (rb->pg_vec) {
4441                         expected_size += rb->pg_vec_len
4442                                                 * rb->pg_vec_pages
4443                                                 * PAGE_SIZE;
4444                 }
4445         }
4446 
4447         if (expected_size == 0)
4448                 goto out;
4449 
4450         size = vma->vm_end - vma->vm_start;
4451         if (size != expected_size)
4452                 goto out;
4453 
4454         start = vma->vm_start;
4455         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4456                 if (rb->pg_vec == NULL)
4457                         continue;
4458 
4459                 for (i = 0; i < rb->pg_vec_len; i++) {
4460                         struct page *page;
4461                         void *kaddr = rb->pg_vec[i].buffer;
4462                         int pg_num;
4463 
4464                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4465                                 page = pgv_to_page(kaddr);
4466                                 err = vm_insert_page(vma, start, page);
4467                                 if (unlikely(err))
4468                                         goto out;
4469                                 start += PAGE_SIZE;
4470                                 kaddr += PAGE_SIZE;
4471                         }
4472                 }
4473         }
4474 
4475         atomic_inc(&po->mapped);
4476         vma->vm_ops = &packet_mmap_ops;
4477         err = 0;
4478 
4479 out:
4480         mutex_unlock(&po->pg_vec_lock);
4481         return err;
4482 }
4483 
4484 static const struct proto_ops packet_ops_spkt = {
4485         .family =       PF_PACKET,
4486         .owner =        THIS_MODULE,
4487         .release =      packet_release,
4488         .bind =         packet_bind_spkt,
4489         .connect =      sock_no_connect,
4490         .socketpair =   sock_no_socketpair,
4491         .accept =       sock_no_accept,
4492         .getname =      packet_getname_spkt,
4493         .poll =         datagram_poll,
4494         .ioctl =        packet_ioctl,
4495         .gettstamp =    sock_gettstamp,
4496         .listen =       sock_no_listen,
4497         .shutdown =     sock_no_shutdown,
4498         .setsockopt =   sock_no_setsockopt,
4499         .getsockopt =   sock_no_getsockopt,
4500         .sendmsg =      packet_sendmsg_spkt,
4501         .recvmsg =      packet_recvmsg,
4502         .mmap =         sock_no_mmap,
4503         .sendpage =     sock_no_sendpage,
4504 };
4505 
4506 static const struct proto_ops packet_ops = {
4507         .family =       PF_PACKET,
4508         .owner =        THIS_MODULE,
4509         .release =      packet_release,
4510         .bind =         packet_bind,
4511         .connect =      sock_no_connect,
4512         .socketpair =   sock_no_socketpair,
4513         .accept =       sock_no_accept,
4514         .getname =      packet_getname,
4515         .poll =         packet_poll,
4516         .ioctl =        packet_ioctl,
4517         .gettstamp =    sock_gettstamp,
4518         .listen =       sock_no_listen,
4519         .shutdown =     sock_no_shutdown,
4520         .setsockopt =   packet_setsockopt,
4521         .getsockopt =   packet_getsockopt,
4522 #ifdef CONFIG_COMPAT
4523         .compat_setsockopt = compat_packet_setsockopt,
4524 #endif
4525         .sendmsg =      packet_sendmsg,
4526         .recvmsg =      packet_recvmsg,
4527         .mmap =         packet_mmap,
4528         .sendpage =     sock_no_sendpage,
4529 };
4530 
4531 static const struct net_proto_family packet_family_ops = {
4532         .family =       PF_PACKET,
4533         .create =       packet_create,
4534         .owner  =       THIS_MODULE,
4535 };
4536 
4537 static struct notifier_block packet_netdev_notifier = {
4538         .notifier_call =        packet_notifier,
4539 };
4540 
4541 #ifdef CONFIG_PROC_FS
4542 
4543 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4544         __acquires(RCU)
4545 {
4546         struct net *net = seq_file_net(seq);
4547 
4548         rcu_read_lock();
4549         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4550 }
4551 
4552 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4553 {
4554         struct net *net = seq_file_net(seq);
4555         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4556 }
4557 
4558 static void packet_seq_stop(struct seq_file *seq, void *v)
4559         __releases(RCU)
4560 {
4561         rcu_read_unlock();
4562 }
4563 
4564 static int packet_seq_show(struct seq_file *seq, void *v)
4565 {
4566         if (v == SEQ_START_TOKEN)
4567                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4568         else {
4569                 struct sock *s = sk_entry(v);
4570                 const struct packet_sock *po = pkt_sk(s);
4571 
4572                 seq_printf(seq,
4573                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4574                            s,
4575                            refcount_read(&s->sk_refcnt),
4576                            s->sk_type,
4577                            ntohs(po->num),
4578                            po->ifindex,
4579                            po->running,
4580                            atomic_read(&s->sk_rmem_alloc),
4581                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4582                            sock_i_ino(s));
4583         }
4584 
4585         return 0;
4586 }
4587 
4588 static const struct seq_operations packet_seq_ops = {
4589         .start  = packet_seq_start,
4590         .next   = packet_seq_next,
4591         .stop   = packet_seq_stop,
4592         .show   = packet_seq_show,
4593 };
4594 #endif
4595 
4596 static int __net_init packet_net_init(struct net *net)
4597 {
4598         mutex_init(&net->packet.sklist_lock);
4599         INIT_HLIST_HEAD(&net->packet.sklist);
4600 
4601         if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4602                         sizeof(struct seq_net_private)))
4603                 return -ENOMEM;
4604 
4605         return 0;
4606 }
4607 
4608 static void __net_exit packet_net_exit(struct net *net)
4609 {
4610         remove_proc_entry("packet", net->proc_net);
4611         WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4612 }
4613 
4614 static struct pernet_operations packet_net_ops = {
4615         .init = packet_net_init,
4616         .exit = packet_net_exit,
4617 };
4618 
4619 
4620 static void __exit packet_exit(void)
4621 {
4622         unregister_netdevice_notifier(&packet_netdev_notifier);
4623         unregister_pernet_subsys(&packet_net_ops);
4624         sock_unregister(PF_PACKET);
4625         proto_unregister(&packet_proto);
4626 }
4627 
4628 static int __init packet_init(void)
4629 {
4630         int rc;
4631 
4632         rc = proto_register(&packet_proto, 0);
4633         if (rc)
4634                 goto out;
4635         rc = sock_register(&packet_family_ops);
4636         if (rc)
4637                 goto out_proto;
4638         rc = register_pernet_subsys(&packet_net_ops);
4639         if (rc)
4640                 goto out_sock;
4641         rc = register_netdevice_notifier(&packet_netdev_notifier);
4642         if (rc)
4643                 goto out_pernet;
4644 
4645         return 0;
4646 
4647 out_pernet:
4648         unregister_pernet_subsys(&packet_net_ops);
4649 out_sock:
4650         sock_unregister(PF_PACKET);
4651 out_proto:
4652         proto_unregister(&packet_proto);
4653 out:
4654         return rc;
4655 }
4656 
4657 module_init(packet_init);
4658 module_exit(packet_exit);
4659 MODULE_LICENSE("GPL");
4660 MODULE_ALIAS_NETPROTO(PF_PACKET);
4661 

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