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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 timespec64 *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_timespec64_cond(shhwtstamps->hwtstamp, ts))
419                 return TP_STATUS_TS_RAW_HARDWARE;
420 
421         if (ktime_to_timespec64_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 timespec64 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         /*
439          * versions 1 through 3 overflow the timestamps in y2106, since they
440          * all store the seconds in a 32-bit unsigned integer.
441          * If we create a version 4, that should have a 64-bit timestamp,
442          * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit
443          * nanoseconds.
444          */
445         switch (po->tp_version) {
446         case TPACKET_V1:
447                 h.h1->tp_sec = ts.tv_sec;
448                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
449                 break;
450         case TPACKET_V2:
451                 h.h2->tp_sec = ts.tv_sec;
452                 h.h2->tp_nsec = ts.tv_nsec;
453                 break;
454         case TPACKET_V3:
455                 h.h3->tp_sec = ts.tv_sec;
456                 h.h3->tp_nsec = ts.tv_nsec;
457                 break;
458         default:
459                 WARN(1, "TPACKET version not supported.\n");
460                 BUG();
461         }
462 
463         /* one flush is safe, as both fields always lie on the same cacheline */
464         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
465         smp_wmb();
466 
467         return ts_status;
468 }
469 
470 static void *packet_lookup_frame(const struct packet_sock *po,
471                                  const struct packet_ring_buffer *rb,
472                                  unsigned int position,
473                                  int status)
474 {
475         unsigned int pg_vec_pos, frame_offset;
476         union tpacket_uhdr h;
477 
478         pg_vec_pos = position / rb->frames_per_block;
479         frame_offset = position % rb->frames_per_block;
480 
481         h.raw = rb->pg_vec[pg_vec_pos].buffer +
482                 (frame_offset * rb->frame_size);
483 
484         if (status != __packet_get_status(po, h.raw))
485                 return NULL;
486 
487         return h.raw;
488 }
489 
490 static void *packet_current_frame(struct packet_sock *po,
491                 struct packet_ring_buffer *rb,
492                 int status)
493 {
494         return packet_lookup_frame(po, rb, rb->head, status);
495 }
496 
497 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
498 {
499         del_timer_sync(&pkc->retire_blk_timer);
500 }
501 
502 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
503                 struct sk_buff_head *rb_queue)
504 {
505         struct tpacket_kbdq_core *pkc;
506 
507         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
508 
509         spin_lock_bh(&rb_queue->lock);
510         pkc->delete_blk_timer = 1;
511         spin_unlock_bh(&rb_queue->lock);
512 
513         prb_del_retire_blk_timer(pkc);
514 }
515 
516 static void prb_setup_retire_blk_timer(struct packet_sock *po)
517 {
518         struct tpacket_kbdq_core *pkc;
519 
520         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
521         timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired,
522                     0);
523         pkc->retire_blk_timer.expires = jiffies;
524 }
525 
526 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
527                                 int blk_size_in_bytes)
528 {
529         struct net_device *dev;
530         unsigned int mbits, div;
531         struct ethtool_link_ksettings ecmd;
532         int err;
533 
534         rtnl_lock();
535         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
536         if (unlikely(!dev)) {
537                 rtnl_unlock();
538                 return DEFAULT_PRB_RETIRE_TOV;
539         }
540         err = __ethtool_get_link_ksettings(dev, &ecmd);
541         rtnl_unlock();
542         if (err)
543                 return DEFAULT_PRB_RETIRE_TOV;
544 
545         /* If the link speed is so slow you don't really
546          * need to worry about perf anyways
547          */
548         if (ecmd.base.speed < SPEED_1000 ||
549             ecmd.base.speed == SPEED_UNKNOWN)
550                 return DEFAULT_PRB_RETIRE_TOV;
551 
552         div = ecmd.base.speed / 1000;
553         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
554 
555         if (div)
556                 mbits /= div;
557 
558         if (div)
559                 return mbits + 1;
560         return mbits;
561 }
562 
563 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
564                         union tpacket_req_u *req_u)
565 {
566         p1->feature_req_word = req_u->req3.tp_feature_req_word;
567 }
568 
569 static void init_prb_bdqc(struct packet_sock *po,
570                         struct packet_ring_buffer *rb,
571                         struct pgv *pg_vec,
572                         union tpacket_req_u *req_u)
573 {
574         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
575         struct tpacket_block_desc *pbd;
576 
577         memset(p1, 0x0, sizeof(*p1));
578 
579         p1->knxt_seq_num = 1;
580         p1->pkbdq = pg_vec;
581         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
582         p1->pkblk_start = pg_vec[0].buffer;
583         p1->kblk_size = req_u->req3.tp_block_size;
584         p1->knum_blocks = req_u->req3.tp_block_nr;
585         p1->hdrlen = po->tp_hdrlen;
586         p1->version = po->tp_version;
587         p1->last_kactive_blk_num = 0;
588         po->stats.stats3.tp_freeze_q_cnt = 0;
589         if (req_u->req3.tp_retire_blk_tov)
590                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
591         else
592                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
593                                                 req_u->req3.tp_block_size);
594         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
595         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
596 
597         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
598         prb_init_ft_ops(p1, req_u);
599         prb_setup_retire_blk_timer(po);
600         prb_open_block(p1, pbd);
601 }
602 
603 /*  Do NOT update the last_blk_num first.
604  *  Assumes sk_buff_head lock is held.
605  */
606 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
607 {
608         mod_timer(&pkc->retire_blk_timer,
609                         jiffies + pkc->tov_in_jiffies);
610         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
611 }
612 
613 /*
614  * Timer logic:
615  * 1) We refresh the timer only when we open a block.
616  *    By doing this we don't waste cycles refreshing the timer
617  *        on packet-by-packet basis.
618  *
619  * With a 1MB block-size, on a 1Gbps line, it will take
620  * i) ~8 ms to fill a block + ii) memcpy etc.
621  * In this cut we are not accounting for the memcpy time.
622  *
623  * So, if the user sets the 'tmo' to 10ms then the timer
624  * will never fire while the block is still getting filled
625  * (which is what we want). However, the user could choose
626  * to close a block early and that's fine.
627  *
628  * But when the timer does fire, we check whether or not to refresh it.
629  * Since the tmo granularity is in msecs, it is not too expensive
630  * to refresh the timer, lets say every '8' msecs.
631  * Either the user can set the 'tmo' or we can derive it based on
632  * a) line-speed and b) block-size.
633  * prb_calc_retire_blk_tmo() calculates the tmo.
634  *
635  */
636 static void prb_retire_rx_blk_timer_expired(struct timer_list *t)
637 {
638         struct packet_sock *po =
639                 from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer);
640         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
641         unsigned int frozen;
642         struct tpacket_block_desc *pbd;
643 
644         spin_lock(&po->sk.sk_receive_queue.lock);
645 
646         frozen = prb_queue_frozen(pkc);
647         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
648 
649         if (unlikely(pkc->delete_blk_timer))
650                 goto out;
651 
652         /* We only need to plug the race when the block is partially filled.
653          * tpacket_rcv:
654          *              lock(); increment BLOCK_NUM_PKTS; unlock()
655          *              copy_bits() is in progress ...
656          *              timer fires on other cpu:
657          *              we can't retire the current block because copy_bits
658          *              is in progress.
659          *
660          */
661         if (BLOCK_NUM_PKTS(pbd)) {
662                 while (atomic_read(&pkc->blk_fill_in_prog)) {
663                         /* Waiting for skb_copy_bits to finish... */
664                         cpu_relax();
665                 }
666         }
667 
668         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
669                 if (!frozen) {
670                         if (!BLOCK_NUM_PKTS(pbd)) {
671                                 /* An empty block. Just refresh the timer. */
672                                 goto refresh_timer;
673                         }
674                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
675                         if (!prb_dispatch_next_block(pkc, po))
676                                 goto refresh_timer;
677                         else
678                                 goto out;
679                 } else {
680                         /* Case 1. Queue was frozen because user-space was
681                          *         lagging behind.
682                          */
683                         if (prb_curr_blk_in_use(pbd)) {
684                                 /*
685                                  * Ok, user-space is still behind.
686                                  * So just refresh the timer.
687                                  */
688                                 goto refresh_timer;
689                         } else {
690                                /* Case 2. queue was frozen,user-space caught up,
691                                 * now the link went idle && the timer fired.
692                                 * We don't have a block to close.So we open this
693                                 * block and restart the timer.
694                                 * opening a block thaws the queue,restarts timer
695                                 * Thawing/timer-refresh is a side effect.
696                                 */
697                                 prb_open_block(pkc, pbd);
698                                 goto out;
699                         }
700                 }
701         }
702 
703 refresh_timer:
704         _prb_refresh_rx_retire_blk_timer(pkc);
705 
706 out:
707         spin_unlock(&po->sk.sk_receive_queue.lock);
708 }
709 
710 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
711                 struct tpacket_block_desc *pbd1, __u32 status)
712 {
713         /* Flush everything minus the block header */
714 
715 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
716         u8 *start, *end;
717 
718         start = (u8 *)pbd1;
719 
720         /* Skip the block header(we know header WILL fit in 4K) */
721         start += PAGE_SIZE;
722 
723         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
724         for (; start < end; start += PAGE_SIZE)
725                 flush_dcache_page(pgv_to_page(start));
726 
727         smp_wmb();
728 #endif
729 
730         /* Now update the block status. */
731 
732         BLOCK_STATUS(pbd1) = status;
733 
734         /* Flush the block header */
735 
736 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
737         start = (u8 *)pbd1;
738         flush_dcache_page(pgv_to_page(start));
739 
740         smp_wmb();
741 #endif
742 }
743 
744 /*
745  * Side effect:
746  *
747  * 1) flush the block
748  * 2) Increment active_blk_num
749  *
750  * Note:We DONT refresh the timer on purpose.
751  *      Because almost always the next block will be opened.
752  */
753 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
754                 struct tpacket_block_desc *pbd1,
755                 struct packet_sock *po, unsigned int stat)
756 {
757         __u32 status = TP_STATUS_USER | stat;
758 
759         struct tpacket3_hdr *last_pkt;
760         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
761         struct sock *sk = &po->sk;
762 
763         if (atomic_read(&po->tp_drops))
764                 status |= TP_STATUS_LOSING;
765 
766         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
767         last_pkt->tp_next_offset = 0;
768 
769         /* Get the ts of the last pkt */
770         if (BLOCK_NUM_PKTS(pbd1)) {
771                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
772                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
773         } else {
774                 /* Ok, we tmo'd - so get the current time.
775                  *
776                  * It shouldn't really happen as we don't close empty
777                  * blocks. See prb_retire_rx_blk_timer_expired().
778                  */
779                 struct timespec64 ts;
780                 ktime_get_real_ts64(&ts);
781                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
782                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
783         }
784 
785         smp_wmb();
786 
787         /* Flush the block */
788         prb_flush_block(pkc1, pbd1, status);
789 
790         sk->sk_data_ready(sk);
791 
792         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
793 }
794 
795 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
796 {
797         pkc->reset_pending_on_curr_blk = 0;
798 }
799 
800 /*
801  * Side effect of opening a block:
802  *
803  * 1) prb_queue is thawed.
804  * 2) retire_blk_timer is refreshed.
805  *
806  */
807 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
808         struct tpacket_block_desc *pbd1)
809 {
810         struct timespec64 ts;
811         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
812 
813         smp_rmb();
814 
815         /* We could have just memset this but we will lose the
816          * flexibility of making the priv area sticky
817          */
818 
819         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
820         BLOCK_NUM_PKTS(pbd1) = 0;
821         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
822 
823         ktime_get_real_ts64(&ts);
824 
825         h1->ts_first_pkt.ts_sec = ts.tv_sec;
826         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
827 
828         pkc1->pkblk_start = (char *)pbd1;
829         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
830 
831         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
832         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
833 
834         pbd1->version = pkc1->version;
835         pkc1->prev = pkc1->nxt_offset;
836         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
837 
838         prb_thaw_queue(pkc1);
839         _prb_refresh_rx_retire_blk_timer(pkc1);
840 
841         smp_wmb();
842 }
843 
844 /*
845  * Queue freeze logic:
846  * 1) Assume tp_block_nr = 8 blocks.
847  * 2) At time 't0', user opens Rx ring.
848  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
849  * 4) user-space is either sleeping or processing block ''.
850  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
851  *    it will close block-7,loop around and try to fill block ''.
852  *    call-flow:
853  *    __packet_lookup_frame_in_block
854  *      prb_retire_current_block()
855  *      prb_dispatch_next_block()
856  *        |->(BLOCK_STATUS == USER) evaluates to true
857  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
858  * 6) Now there are two cases:
859  *    6.1) Link goes idle right after the queue is frozen.
860  *         But remember, the last open_block() refreshed the timer.
861  *         When this timer expires,it will refresh itself so that we can
862  *         re-open block-0 in near future.
863  *    6.2) Link is busy and keeps on receiving packets. This is a simple
864  *         case and __packet_lookup_frame_in_block will check if block-0
865  *         is free and can now be re-used.
866  */
867 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
868                                   struct packet_sock *po)
869 {
870         pkc->reset_pending_on_curr_blk = 1;
871         po->stats.stats3.tp_freeze_q_cnt++;
872 }
873 
874 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
875 
876 /*
877  * If the next block is free then we will dispatch it
878  * and return a good offset.
879  * Else, we will freeze the queue.
880  * So, caller must check the return value.
881  */
882 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
883                 struct packet_sock *po)
884 {
885         struct tpacket_block_desc *pbd;
886 
887         smp_rmb();
888 
889         /* 1. Get current block num */
890         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
891 
892         /* 2. If this block is currently in_use then freeze the queue */
893         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
894                 prb_freeze_queue(pkc, po);
895                 return NULL;
896         }
897 
898         /*
899          * 3.
900          * open this block and return the offset where the first packet
901          * needs to get stored.
902          */
903         prb_open_block(pkc, pbd);
904         return (void *)pkc->nxt_offset;
905 }
906 
907 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
908                 struct packet_sock *po, unsigned int status)
909 {
910         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
911 
912         /* retire/close the current block */
913         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
914                 /*
915                  * Plug the case where copy_bits() is in progress on
916                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
917                  * have space to copy the pkt in the current block and
918                  * called prb_retire_current_block()
919                  *
920                  * We don't need to worry about the TMO case because
921                  * the timer-handler already handled this case.
922                  */
923                 if (!(status & TP_STATUS_BLK_TMO)) {
924                         while (atomic_read(&pkc->blk_fill_in_prog)) {
925                                 /* Waiting for skb_copy_bits to finish... */
926                                 cpu_relax();
927                         }
928                 }
929                 prb_close_block(pkc, pbd, po, status);
930                 return;
931         }
932 }
933 
934 static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd)
935 {
936         return TP_STATUS_USER & BLOCK_STATUS(pbd);
937 }
938 
939 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
940 {
941         return pkc->reset_pending_on_curr_blk;
942 }
943 
944 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
945         __releases(&pkc->blk_fill_in_prog_lock)
946 {
947         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
948         atomic_dec(&pkc->blk_fill_in_prog);
949 }
950 
951 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
952                         struct tpacket3_hdr *ppd)
953 {
954         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
955 }
956 
957 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
958                         struct tpacket3_hdr *ppd)
959 {
960         ppd->hv1.tp_rxhash = 0;
961 }
962 
963 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
964                         struct tpacket3_hdr *ppd)
965 {
966         if (skb_vlan_tag_present(pkc->skb)) {
967                 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
968                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
969                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
970         } else {
971                 ppd->hv1.tp_vlan_tci = 0;
972                 ppd->hv1.tp_vlan_tpid = 0;
973                 ppd->tp_status = TP_STATUS_AVAILABLE;
974         }
975 }
976 
977 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
978                         struct tpacket3_hdr *ppd)
979 {
980         ppd->hv1.tp_padding = 0;
981         prb_fill_vlan_info(pkc, ppd);
982 
983         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
984                 prb_fill_rxhash(pkc, ppd);
985         else
986                 prb_clear_rxhash(pkc, ppd);
987 }
988 
989 static void prb_fill_curr_block(char *curr,
990                                 struct tpacket_kbdq_core *pkc,
991                                 struct tpacket_block_desc *pbd,
992                                 unsigned int len)
993         __acquires(&pkc->blk_fill_in_prog_lock)
994 {
995         struct tpacket3_hdr *ppd;
996 
997         ppd  = (struct tpacket3_hdr *)curr;
998         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
999         pkc->prev = curr;
1000         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1001         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1002         BLOCK_NUM_PKTS(pbd) += 1;
1003         atomic_inc(&pkc->blk_fill_in_prog);
1004         prb_run_all_ft_ops(pkc, ppd);
1005 }
1006 
1007 /* Assumes caller has the sk->rx_queue.lock */
1008 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1009                                             struct sk_buff *skb,
1010                                             unsigned int len
1011                                             )
1012 {
1013         struct tpacket_kbdq_core *pkc;
1014         struct tpacket_block_desc *pbd;
1015         char *curr, *end;
1016 
1017         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1018         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1019 
1020         /* Queue is frozen when user space is lagging behind */
1021         if (prb_queue_frozen(pkc)) {
1022                 /*
1023                  * Check if that last block which caused the queue to freeze,
1024                  * is still in_use by user-space.
1025                  */
1026                 if (prb_curr_blk_in_use(pbd)) {
1027                         /* Can't record this packet */
1028                         return NULL;
1029                 } else {
1030                         /*
1031                          * Ok, the block was released by user-space.
1032                          * Now let's open that block.
1033                          * opening a block also thaws the queue.
1034                          * Thawing is a side effect.
1035                          */
1036                         prb_open_block(pkc, pbd);
1037                 }
1038         }
1039 
1040         smp_mb();
1041         curr = pkc->nxt_offset;
1042         pkc->skb = skb;
1043         end = (char *)pbd + pkc->kblk_size;
1044 
1045         /* first try the current block */
1046         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1047                 prb_fill_curr_block(curr, pkc, pbd, len);
1048                 return (void *)curr;
1049         }
1050 
1051         /* Ok, close the current block */
1052         prb_retire_current_block(pkc, po, 0);
1053 
1054         /* Now, try to dispatch the next block */
1055         curr = (char *)prb_dispatch_next_block(pkc, po);
1056         if (curr) {
1057                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1058                 prb_fill_curr_block(curr, pkc, pbd, len);
1059                 return (void *)curr;
1060         }
1061 
1062         /*
1063          * No free blocks are available.user_space hasn't caught up yet.
1064          * Queue was just frozen and now this packet will get dropped.
1065          */
1066         return NULL;
1067 }
1068 
1069 static void *packet_current_rx_frame(struct packet_sock *po,
1070                                             struct sk_buff *skb,
1071                                             int status, unsigned int len)
1072 {
1073         char *curr = NULL;
1074         switch (po->tp_version) {
1075         case TPACKET_V1:
1076         case TPACKET_V2:
1077                 curr = packet_lookup_frame(po, &po->rx_ring,
1078                                         po->rx_ring.head, status);
1079                 return curr;
1080         case TPACKET_V3:
1081                 return __packet_lookup_frame_in_block(po, skb, len);
1082         default:
1083                 WARN(1, "TPACKET version not supported\n");
1084                 BUG();
1085                 return NULL;
1086         }
1087 }
1088 
1089 static void *prb_lookup_block(const struct packet_sock *po,
1090                               const struct packet_ring_buffer *rb,
1091                               unsigned int idx,
1092                               int status)
1093 {
1094         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1095         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1096 
1097         if (status != BLOCK_STATUS(pbd))
1098                 return NULL;
1099         return pbd;
1100 }
1101 
1102 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1103 {
1104         unsigned int prev;
1105         if (rb->prb_bdqc.kactive_blk_num)
1106                 prev = rb->prb_bdqc.kactive_blk_num-1;
1107         else
1108                 prev = rb->prb_bdqc.knum_blocks-1;
1109         return prev;
1110 }
1111 
1112 /* Assumes caller has held the rx_queue.lock */
1113 static void *__prb_previous_block(struct packet_sock *po,
1114                                          struct packet_ring_buffer *rb,
1115                                          int status)
1116 {
1117         unsigned int previous = prb_previous_blk_num(rb);
1118         return prb_lookup_block(po, rb, previous, status);
1119 }
1120 
1121 static void *packet_previous_rx_frame(struct packet_sock *po,
1122                                              struct packet_ring_buffer *rb,
1123                                              int status)
1124 {
1125         if (po->tp_version <= TPACKET_V2)
1126                 return packet_previous_frame(po, rb, status);
1127 
1128         return __prb_previous_block(po, rb, status);
1129 }
1130 
1131 static void packet_increment_rx_head(struct packet_sock *po,
1132                                             struct packet_ring_buffer *rb)
1133 {
1134         switch (po->tp_version) {
1135         case TPACKET_V1:
1136         case TPACKET_V2:
1137                 return packet_increment_head(rb);
1138         case TPACKET_V3:
1139         default:
1140                 WARN(1, "TPACKET version not supported.\n");
1141                 BUG();
1142                 return;
1143         }
1144 }
1145 
1146 static void *packet_previous_frame(struct packet_sock *po,
1147                 struct packet_ring_buffer *rb,
1148                 int status)
1149 {
1150         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1151         return packet_lookup_frame(po, rb, previous, status);
1152 }
1153 
1154 static void packet_increment_head(struct packet_ring_buffer *buff)
1155 {
1156         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1157 }
1158 
1159 static void packet_inc_pending(struct packet_ring_buffer *rb)
1160 {
1161         this_cpu_inc(*rb->pending_refcnt);
1162 }
1163 
1164 static void packet_dec_pending(struct packet_ring_buffer *rb)
1165 {
1166         this_cpu_dec(*rb->pending_refcnt);
1167 }
1168 
1169 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1170 {
1171         unsigned int refcnt = 0;
1172         int cpu;
1173 
1174         /* We don't use pending refcount in rx_ring. */
1175         if (rb->pending_refcnt == NULL)
1176                 return 0;
1177 
1178         for_each_possible_cpu(cpu)
1179                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1180 
1181         return refcnt;
1182 }
1183 
1184 static int packet_alloc_pending(struct packet_sock *po)
1185 {
1186         po->rx_ring.pending_refcnt = NULL;
1187 
1188         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1189         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1190                 return -ENOBUFS;
1191 
1192         return 0;
1193 }
1194 
1195 static void packet_free_pending(struct packet_sock *po)
1196 {
1197         free_percpu(po->tx_ring.pending_refcnt);
1198 }
1199 
1200 #define ROOM_POW_OFF    2
1201 #define ROOM_NONE       0x0
1202 #define ROOM_LOW        0x1
1203 #define ROOM_NORMAL     0x2
1204 
1205 static bool __tpacket_has_room(const struct packet_sock *po, int pow_off)
1206 {
1207         int idx, len;
1208 
1209         len = READ_ONCE(po->rx_ring.frame_max) + 1;
1210         idx = READ_ONCE(po->rx_ring.head);
1211         if (pow_off)
1212                 idx += len >> pow_off;
1213         if (idx >= len)
1214                 idx -= len;
1215         return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1216 }
1217 
1218 static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off)
1219 {
1220         int idx, len;
1221 
1222         len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks);
1223         idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num);
1224         if (pow_off)
1225                 idx += len >> pow_off;
1226         if (idx >= len)
1227                 idx -= len;
1228         return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1229 }
1230 
1231 static int __packet_rcv_has_room(const struct packet_sock *po,
1232                                  const struct sk_buff *skb)
1233 {
1234         const struct sock *sk = &po->sk;
1235         int ret = ROOM_NONE;
1236 
1237         if (po->prot_hook.func != tpacket_rcv) {
1238                 int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
1239                 int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1240                                    - (skb ? skb->truesize : 0);
1241 
1242                 if (avail > (rcvbuf >> ROOM_POW_OFF))
1243                         return ROOM_NORMAL;
1244                 else if (avail > 0)
1245                         return ROOM_LOW;
1246                 else
1247                         return ROOM_NONE;
1248         }
1249 
1250         if (po->tp_version == TPACKET_V3) {
1251                 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1252                         ret = ROOM_NORMAL;
1253                 else if (__tpacket_v3_has_room(po, 0))
1254                         ret = ROOM_LOW;
1255         } else {
1256                 if (__tpacket_has_room(po, ROOM_POW_OFF))
1257                         ret = ROOM_NORMAL;
1258                 else if (__tpacket_has_room(po, 0))
1259                         ret = ROOM_LOW;
1260         }
1261 
1262         return ret;
1263 }
1264 
1265 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1266 {
1267         int pressure, ret;
1268 
1269         ret = __packet_rcv_has_room(po, skb);
1270         pressure = ret != ROOM_NORMAL;
1271 
1272         if (READ_ONCE(po->pressure) != pressure)
1273                 WRITE_ONCE(po->pressure, pressure);
1274 
1275         return ret;
1276 }
1277 
1278 static void packet_rcv_try_clear_pressure(struct packet_sock *po)
1279 {
1280         if (READ_ONCE(po->pressure) &&
1281             __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
1282                 WRITE_ONCE(po->pressure,  0);
1283 }
1284 
1285 static void packet_sock_destruct(struct sock *sk)
1286 {
1287         skb_queue_purge(&sk->sk_error_queue);
1288 
1289         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1290         WARN_ON(refcount_read(&sk->sk_wmem_alloc));
1291 
1292         if (!sock_flag(sk, SOCK_DEAD)) {
1293                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1294                 return;
1295         }
1296 
1297         sk_refcnt_debug_dec(sk);
1298 }
1299 
1300 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1301 {
1302         u32 *history = po->rollover->history;
1303         u32 victim, rxhash;
1304         int i, count = 0;
1305 
1306         rxhash = skb_get_hash(skb);
1307         for (i = 0; i < ROLLOVER_HLEN; i++)
1308                 if (READ_ONCE(history[i]) == rxhash)
1309                         count++;
1310 
1311         victim = prandom_u32() % ROLLOVER_HLEN;
1312 
1313         /* Avoid dirtying the cache line if possible */
1314         if (READ_ONCE(history[victim]) != rxhash)
1315                 WRITE_ONCE(history[victim], rxhash);
1316 
1317         return count > (ROLLOVER_HLEN >> 1);
1318 }
1319 
1320 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1321                                       struct sk_buff *skb,
1322                                       unsigned int num)
1323 {
1324         return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1325 }
1326 
1327 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1328                                     struct sk_buff *skb,
1329                                     unsigned int num)
1330 {
1331         unsigned int val = atomic_inc_return(&f->rr_cur);
1332 
1333         return val % num;
1334 }
1335 
1336 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1337                                      struct sk_buff *skb,
1338                                      unsigned int num)
1339 {
1340         return smp_processor_id() % num;
1341 }
1342 
1343 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1344                                      struct sk_buff *skb,
1345                                      unsigned int num)
1346 {
1347         return prandom_u32_max(num);
1348 }
1349 
1350 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1351                                           struct sk_buff *skb,
1352                                           unsigned int idx, bool try_self,
1353                                           unsigned int num)
1354 {
1355         struct packet_sock *po, *po_next, *po_skip = NULL;
1356         unsigned int i, j, room = ROOM_NONE;
1357 
1358         po = pkt_sk(f->arr[idx]);
1359 
1360         if (try_self) {
1361                 room = packet_rcv_has_room(po, skb);
1362                 if (room == ROOM_NORMAL ||
1363                     (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1364                         return idx;
1365                 po_skip = po;
1366         }
1367 
1368         i = j = min_t(int, po->rollover->sock, num - 1);
1369         do {
1370                 po_next = pkt_sk(f->arr[i]);
1371                 if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
1372                     packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1373                         if (i != j)
1374                                 po->rollover->sock = i;
1375                         atomic_long_inc(&po->rollover->num);
1376                         if (room == ROOM_LOW)
1377                                 atomic_long_inc(&po->rollover->num_huge);
1378                         return i;
1379                 }
1380 
1381                 if (++i == num)
1382                         i = 0;
1383         } while (i != j);
1384 
1385         atomic_long_inc(&po->rollover->num_failed);
1386         return idx;
1387 }
1388 
1389 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1390                                     struct sk_buff *skb,
1391                                     unsigned int num)
1392 {
1393         return skb_get_queue_mapping(skb) % num;
1394 }
1395 
1396 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1397                                      struct sk_buff *skb,
1398                                      unsigned int num)
1399 {
1400         struct bpf_prog *prog;
1401         unsigned int ret = 0;
1402 
1403         rcu_read_lock();
1404         prog = rcu_dereference(f->bpf_prog);
1405         if (prog)
1406                 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1407         rcu_read_unlock();
1408 
1409         return ret;
1410 }
1411 
1412 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1413 {
1414         return f->flags & (flag >> 8);
1415 }
1416 
1417 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1418                              struct packet_type *pt, struct net_device *orig_dev)
1419 {
1420         struct packet_fanout *f = pt->af_packet_priv;
1421         unsigned int num = READ_ONCE(f->num_members);
1422         struct net *net = read_pnet(&f->net);
1423         struct packet_sock *po;
1424         unsigned int idx;
1425 
1426         if (!net_eq(dev_net(dev), net) || !num) {
1427                 kfree_skb(skb);
1428                 return 0;
1429         }
1430 
1431         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1432                 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1433                 if (!skb)
1434                         return 0;
1435         }
1436         switch (f->type) {
1437         case PACKET_FANOUT_HASH:
1438         default:
1439                 idx = fanout_demux_hash(f, skb, num);
1440                 break;
1441         case PACKET_FANOUT_LB:
1442                 idx = fanout_demux_lb(f, skb, num);
1443                 break;
1444         case PACKET_FANOUT_CPU:
1445                 idx = fanout_demux_cpu(f, skb, num);
1446                 break;
1447         case PACKET_FANOUT_RND:
1448                 idx = fanout_demux_rnd(f, skb, num);
1449                 break;
1450         case PACKET_FANOUT_QM:
1451                 idx = fanout_demux_qm(f, skb, num);
1452                 break;
1453         case PACKET_FANOUT_ROLLOVER:
1454                 idx = fanout_demux_rollover(f, skb, 0, false, num);
1455                 break;
1456         case PACKET_FANOUT_CBPF:
1457         case PACKET_FANOUT_EBPF:
1458                 idx = fanout_demux_bpf(f, skb, num);
1459                 break;
1460         }
1461 
1462         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1463                 idx = fanout_demux_rollover(f, skb, idx, true, num);
1464 
1465         po = pkt_sk(f->arr[idx]);
1466         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1467 }
1468 
1469 DEFINE_MUTEX(fanout_mutex);
1470 EXPORT_SYMBOL_GPL(fanout_mutex);
1471 static LIST_HEAD(fanout_list);
1472 static u16 fanout_next_id;
1473 
1474 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1475 {
1476         struct packet_fanout *f = po->fanout;
1477 
1478         spin_lock(&f->lock);
1479         f->arr[f->num_members] = sk;
1480         smp_wmb();
1481         f->num_members++;
1482         if (f->num_members == 1)
1483                 dev_add_pack(&f->prot_hook);
1484         spin_unlock(&f->lock);
1485 }
1486 
1487 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1488 {
1489         struct packet_fanout *f = po->fanout;
1490         int i;
1491 
1492         spin_lock(&f->lock);
1493         for (i = 0; i < f->num_members; i++) {
1494                 if (f->arr[i] == sk)
1495                         break;
1496         }
1497         BUG_ON(i >= f->num_members);
1498         f->arr[i] = f->arr[f->num_members - 1];
1499         f->num_members--;
1500         if (f->num_members == 0)
1501                 __dev_remove_pack(&f->prot_hook);
1502         spin_unlock(&f->lock);
1503 }
1504 
1505 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1506 {
1507         if (sk->sk_family != PF_PACKET)
1508                 return false;
1509 
1510         return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1511 }
1512 
1513 static void fanout_init_data(struct packet_fanout *f)
1514 {
1515         switch (f->type) {
1516         case PACKET_FANOUT_LB:
1517                 atomic_set(&f->rr_cur, 0);
1518                 break;
1519         case PACKET_FANOUT_CBPF:
1520         case PACKET_FANOUT_EBPF:
1521                 RCU_INIT_POINTER(f->bpf_prog, NULL);
1522                 break;
1523         }
1524 }
1525 
1526 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1527 {
1528         struct bpf_prog *old;
1529 
1530         spin_lock(&f->lock);
1531         old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1532         rcu_assign_pointer(f->bpf_prog, new);
1533         spin_unlock(&f->lock);
1534 
1535         if (old) {
1536                 synchronize_net();
1537                 bpf_prog_destroy(old);
1538         }
1539 }
1540 
1541 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1542                                 unsigned int len)
1543 {
1544         struct bpf_prog *new;
1545         struct sock_fprog fprog;
1546         int ret;
1547 
1548         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1549                 return -EPERM;
1550         if (len != sizeof(fprog))
1551                 return -EINVAL;
1552         if (copy_from_user(&fprog, data, len))
1553                 return -EFAULT;
1554 
1555         ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1556         if (ret)
1557                 return ret;
1558 
1559         __fanout_set_data_bpf(po->fanout, new);
1560         return 0;
1561 }
1562 
1563 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1564                                 unsigned int len)
1565 {
1566         struct bpf_prog *new;
1567         u32 fd;
1568 
1569         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1570                 return -EPERM;
1571         if (len != sizeof(fd))
1572                 return -EINVAL;
1573         if (copy_from_user(&fd, data, len))
1574                 return -EFAULT;
1575 
1576         new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1577         if (IS_ERR(new))
1578                 return PTR_ERR(new);
1579 
1580         __fanout_set_data_bpf(po->fanout, new);
1581         return 0;
1582 }
1583 
1584 static int fanout_set_data(struct packet_sock *po, char __user *data,
1585                            unsigned int len)
1586 {
1587         switch (po->fanout->type) {
1588         case PACKET_FANOUT_CBPF:
1589                 return fanout_set_data_cbpf(po, data, len);
1590         case PACKET_FANOUT_EBPF:
1591                 return fanout_set_data_ebpf(po, data, len);
1592         default:
1593                 return -EINVAL;
1594         }
1595 }
1596 
1597 static void fanout_release_data(struct packet_fanout *f)
1598 {
1599         switch (f->type) {
1600         case PACKET_FANOUT_CBPF:
1601         case PACKET_FANOUT_EBPF:
1602                 __fanout_set_data_bpf(f, NULL);
1603         }
1604 }
1605 
1606 static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)
1607 {
1608         struct packet_fanout *f;
1609 
1610         list_for_each_entry(f, &fanout_list, list) {
1611                 if (f->id == candidate_id &&
1612                     read_pnet(&f->net) == sock_net(sk)) {
1613                         return false;
1614                 }
1615         }
1616         return true;
1617 }
1618 
1619 static bool fanout_find_new_id(struct sock *sk, u16 *new_id)
1620 {
1621         u16 id = fanout_next_id;
1622 
1623         do {
1624                 if (__fanout_id_is_free(sk, id)) {
1625                         *new_id = id;
1626                         fanout_next_id = id + 1;
1627                         return true;
1628                 }
1629 
1630                 id++;
1631         } while (id != fanout_next_id);
1632 
1633         return false;
1634 }
1635 
1636 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1637 {
1638         struct packet_rollover *rollover = NULL;
1639         struct packet_sock *po = pkt_sk(sk);
1640         struct packet_fanout *f, *match;
1641         u8 type = type_flags & 0xff;
1642         u8 flags = type_flags >> 8;
1643         int err;
1644 
1645         switch (type) {
1646         case PACKET_FANOUT_ROLLOVER:
1647                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1648                         return -EINVAL;
1649         case PACKET_FANOUT_HASH:
1650         case PACKET_FANOUT_LB:
1651         case PACKET_FANOUT_CPU:
1652         case PACKET_FANOUT_RND:
1653         case PACKET_FANOUT_QM:
1654         case PACKET_FANOUT_CBPF:
1655         case PACKET_FANOUT_EBPF:
1656                 break;
1657         default:
1658                 return -EINVAL;
1659         }
1660 
1661         mutex_lock(&fanout_mutex);
1662 
1663         err = -EALREADY;
1664         if (po->fanout)
1665                 goto out;
1666 
1667         if (type == PACKET_FANOUT_ROLLOVER ||
1668             (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1669                 err = -ENOMEM;
1670                 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1671                 if (!rollover)
1672                         goto out;
1673                 atomic_long_set(&rollover->num, 0);
1674                 atomic_long_set(&rollover->num_huge, 0);
1675                 atomic_long_set(&rollover->num_failed, 0);
1676         }
1677 
1678         if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {
1679                 if (id != 0) {
1680                         err = -EINVAL;
1681                         goto out;
1682                 }
1683                 if (!fanout_find_new_id(sk, &id)) {
1684                         err = -ENOMEM;
1685                         goto out;
1686                 }
1687                 /* ephemeral flag for the first socket in the group: drop it */
1688                 flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);
1689         }
1690 
1691         match = NULL;
1692         list_for_each_entry(f, &fanout_list, list) {
1693                 if (f->id == id &&
1694                     read_pnet(&f->net) == sock_net(sk)) {
1695                         match = f;
1696                         break;
1697                 }
1698         }
1699         err = -EINVAL;
1700         if (match && match->flags != flags)
1701                 goto out;
1702         if (!match) {
1703                 err = -ENOMEM;
1704                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1705                 if (!match)
1706                         goto out;
1707                 write_pnet(&match->net, sock_net(sk));
1708                 match->id = id;
1709                 match->type = type;
1710                 match->flags = flags;
1711                 INIT_LIST_HEAD(&match->list);
1712                 spin_lock_init(&match->lock);
1713                 refcount_set(&match->sk_ref, 0);
1714                 fanout_init_data(match);
1715                 match->prot_hook.type = po->prot_hook.type;
1716                 match->prot_hook.dev = po->prot_hook.dev;
1717                 match->prot_hook.func = packet_rcv_fanout;
1718                 match->prot_hook.af_packet_priv = match;
1719                 match->prot_hook.id_match = match_fanout_group;
1720                 list_add(&match->list, &fanout_list);
1721         }
1722         err = -EINVAL;
1723 
1724         spin_lock(&po->bind_lock);
1725         if (po->running &&
1726             match->type == type &&
1727             match->prot_hook.type == po->prot_hook.type &&
1728             match->prot_hook.dev == po->prot_hook.dev) {
1729                 err = -ENOSPC;
1730                 if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1731                         __dev_remove_pack(&po->prot_hook);
1732                         po->fanout = match;
1733                         po->rollover = rollover;
1734                         rollover = NULL;
1735                         refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
1736                         __fanout_link(sk, po);
1737                         err = 0;
1738                 }
1739         }
1740         spin_unlock(&po->bind_lock);
1741 
1742         if (err && !refcount_read(&match->sk_ref)) {
1743                 list_del(&match->list);
1744                 kfree(match);
1745         }
1746 
1747 out:
1748         kfree(rollover);
1749         mutex_unlock(&fanout_mutex);
1750         return err;
1751 }
1752 
1753 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1754  * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1755  * It is the responsibility of the caller to call fanout_release_data() and
1756  * free the returned packet_fanout (after synchronize_net())
1757  */
1758 static struct packet_fanout *fanout_release(struct sock *sk)
1759 {
1760         struct packet_sock *po = pkt_sk(sk);
1761         struct packet_fanout *f;
1762 
1763         mutex_lock(&fanout_mutex);
1764         f = po->fanout;
1765         if (f) {
1766                 po->fanout = NULL;
1767 
1768                 if (refcount_dec_and_test(&f->sk_ref))
1769                         list_del(&f->list);
1770                 else
1771                         f = NULL;
1772         }
1773         mutex_unlock(&fanout_mutex);
1774 
1775         return f;
1776 }
1777 
1778 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1779                                           struct sk_buff *skb)
1780 {
1781         /* Earlier code assumed this would be a VLAN pkt, double-check
1782          * this now that we have the actual packet in hand. We can only
1783          * do this check on Ethernet devices.
1784          */
1785         if (unlikely(dev->type != ARPHRD_ETHER))
1786                 return false;
1787 
1788         skb_reset_mac_header(skb);
1789         return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1790 }
1791 
1792 static const struct proto_ops packet_ops;
1793 
1794 static const struct proto_ops packet_ops_spkt;
1795 
1796 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1797                            struct packet_type *pt, struct net_device *orig_dev)
1798 {
1799         struct sock *sk;
1800         struct sockaddr_pkt *spkt;
1801 
1802         /*
1803          *      When we registered the protocol we saved the socket in the data
1804          *      field for just this event.
1805          */
1806 
1807         sk = pt->af_packet_priv;
1808 
1809         /*
1810          *      Yank back the headers [hope the device set this
1811          *      right or kerboom...]
1812          *
1813          *      Incoming packets have ll header pulled,
1814          *      push it back.
1815          *
1816          *      For outgoing ones skb->data == skb_mac_header(skb)
1817          *      so that this procedure is noop.
1818          */
1819 
1820         if (skb->pkt_type == PACKET_LOOPBACK)
1821                 goto out;
1822 
1823         if (!net_eq(dev_net(dev), sock_net(sk)))
1824                 goto out;
1825 
1826         skb = skb_share_check(skb, GFP_ATOMIC);
1827         if (skb == NULL)
1828                 goto oom;
1829 
1830         /* drop any routing info */
1831         skb_dst_drop(skb);
1832 
1833         /* drop conntrack reference */
1834         nf_reset_ct(skb);
1835 
1836         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1837 
1838         skb_push(skb, skb->data - skb_mac_header(skb));
1839 
1840         /*
1841          *      The SOCK_PACKET socket receives _all_ frames.
1842          */
1843 
1844         spkt->spkt_family = dev->type;
1845         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1846         spkt->spkt_protocol = skb->protocol;
1847 
1848         /*
1849          *      Charge the memory to the socket. This is done specifically
1850          *      to prevent sockets using all the memory up.
1851          */
1852 
1853         if (sock_queue_rcv_skb(sk, skb) == 0)
1854                 return 0;
1855 
1856 out:
1857         kfree_skb(skb);
1858 oom:
1859         return 0;
1860 }
1861 
1862 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
1863 {
1864         if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
1865             sock->type == SOCK_RAW) {
1866                 skb_reset_mac_header(skb);
1867                 skb->protocol = dev_parse_header_protocol(skb);
1868         }
1869 
1870         skb_probe_transport_header(skb);
1871 }
1872 
1873 /*
1874  *      Output a raw packet to a device layer. This bypasses all the other
1875  *      protocol layers and you must therefore supply it with a complete frame
1876  */
1877 
1878 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1879                                size_t len)
1880 {
1881         struct sock *sk = sock->sk;
1882         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1883         struct sk_buff *skb = NULL;
1884         struct net_device *dev;
1885         struct sockcm_cookie sockc;
1886         __be16 proto = 0;
1887         int err;
1888         int extra_len = 0;
1889 
1890         /*
1891          *      Get and verify the address.
1892          */
1893 
1894         if (saddr) {
1895                 if (msg->msg_namelen < sizeof(struct sockaddr))
1896                         return -EINVAL;
1897                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1898                         proto = saddr->spkt_protocol;
1899         } else
1900                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1901 
1902         /*
1903          *      Find the device first to size check it
1904          */
1905 
1906         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1907 retry:
1908         rcu_read_lock();
1909         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1910         err = -ENODEV;
1911         if (dev == NULL)
1912                 goto out_unlock;
1913 
1914         err = -ENETDOWN;
1915         if (!(dev->flags & IFF_UP))
1916                 goto out_unlock;
1917 
1918         /*
1919          * You may not queue a frame bigger than the mtu. This is the lowest level
1920          * raw protocol and you must do your own fragmentation at this level.
1921          */
1922 
1923         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1924                 if (!netif_supports_nofcs(dev)) {
1925                         err = -EPROTONOSUPPORT;
1926                         goto out_unlock;
1927                 }
1928                 extra_len = 4; /* We're doing our own CRC */
1929         }
1930 
1931         err = -EMSGSIZE;
1932         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1933                 goto out_unlock;
1934 
1935         if (!skb) {
1936                 size_t reserved = LL_RESERVED_SPACE(dev);
1937                 int tlen = dev->needed_tailroom;
1938                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1939 
1940                 rcu_read_unlock();
1941                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1942                 if (skb == NULL)
1943                         return -ENOBUFS;
1944                 /* FIXME: Save some space for broken drivers that write a hard
1945                  * header at transmission time by themselves. PPP is the notable
1946                  * one here. This should really be fixed at the driver level.
1947                  */
1948                 skb_reserve(skb, reserved);
1949                 skb_reset_network_header(skb);
1950 
1951                 /* Try to align data part correctly */
1952                 if (hhlen) {
1953                         skb->data -= hhlen;
1954                         skb->tail -= hhlen;
1955                         if (len < hhlen)
1956                                 skb_reset_network_header(skb);
1957                 }
1958                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1959                 if (err)
1960                         goto out_free;
1961                 goto retry;
1962         }
1963 
1964         if (!dev_validate_header(dev, skb->data, len)) {
1965                 err = -EINVAL;
1966                 goto out_unlock;
1967         }
1968         if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1969             !packet_extra_vlan_len_allowed(dev, skb)) {
1970                 err = -EMSGSIZE;
1971                 goto out_unlock;
1972         }
1973 
1974         sockcm_init(&sockc, sk);
1975         if (msg->msg_controllen) {
1976                 err = sock_cmsg_send(sk, msg, &sockc);
1977                 if (unlikely(err))
1978                         goto out_unlock;
1979         }
1980 
1981         skb->protocol = proto;
1982         skb->dev = dev;
1983         skb->priority = sk->sk_priority;
1984         skb->mark = sk->sk_mark;
1985         skb->tstamp = sockc.transmit_time;
1986 
1987         skb_setup_tx_timestamp(skb, sockc.tsflags);
1988 
1989         if (unlikely(extra_len == 4))
1990                 skb->no_fcs = 1;
1991 
1992         packet_parse_headers(skb, sock);
1993 
1994         dev_queue_xmit(skb);
1995         rcu_read_unlock();
1996         return len;
1997 
1998 out_unlock:
1999         rcu_read_unlock();
2000 out_free:
2001         kfree_skb(skb);
2002         return err;
2003 }
2004 
2005 static unsigned int run_filter(struct sk_buff *skb,
2006                                const struct sock *sk,
2007                                unsigned int res)
2008 {
2009         struct sk_filter *filter;
2010 
2011         rcu_read_lock();
2012         filter = rcu_dereference(sk->sk_filter);
2013         if (filter != NULL)
2014                 res = bpf_prog_run_clear_cb(filter->prog, skb);
2015         rcu_read_unlock();
2016 
2017         return res;
2018 }
2019 
2020 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
2021                            size_t *len)
2022 {
2023         struct virtio_net_hdr vnet_hdr;
2024 
2025         if (*len < sizeof(vnet_hdr))
2026                 return -EINVAL;
2027         *len -= sizeof(vnet_hdr);
2028 
2029         if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true, 0))
2030                 return -EINVAL;
2031 
2032         return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2033 }
2034 
2035 /*
2036  * This function makes lazy skb cloning in hope that most of packets
2037  * are discarded by BPF.
2038  *
2039  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2040  * and skb->cb are mangled. It works because (and until) packets
2041  * falling here are owned by current CPU. Output packets are cloned
2042  * by dev_queue_xmit_nit(), input packets are processed by net_bh
2043  * sequencially, so that if we return skb to original state on exit,
2044  * we will not harm anyone.
2045  */
2046 
2047 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2048                       struct packet_type *pt, struct net_device *orig_dev)
2049 {
2050         struct sock *sk;
2051         struct sockaddr_ll *sll;
2052         struct packet_sock *po;
2053         u8 *skb_head = skb->data;
2054         int skb_len = skb->len;
2055         unsigned int snaplen, res;
2056         bool is_drop_n_account = false;
2057 
2058         if (skb->pkt_type == PACKET_LOOPBACK)
2059                 goto drop;
2060 
2061         sk = pt->af_packet_priv;
2062         po = pkt_sk(sk);
2063 
2064         if (!net_eq(dev_net(dev), sock_net(sk)))
2065                 goto drop;
2066 
2067         skb->dev = dev;
2068 
2069         if (dev->header_ops) {
2070                 /* The device has an explicit notion of ll header,
2071                  * exported to higher levels.
2072                  *
2073                  * Otherwise, the device hides details of its frame
2074                  * structure, so that corresponding packet head is
2075                  * never delivered to user.
2076                  */
2077                 if (sk->sk_type != SOCK_DGRAM)
2078                         skb_push(skb, skb->data - skb_mac_header(skb));
2079                 else if (skb->pkt_type == PACKET_OUTGOING) {
2080                         /* Special case: outgoing packets have ll header at head */
2081                         skb_pull(skb, skb_network_offset(skb));
2082                 }
2083         }
2084 
2085         snaplen = skb->len;
2086 
2087         res = run_filter(skb, sk, snaplen);
2088         if (!res)
2089                 goto drop_n_restore;
2090         if (snaplen > res)
2091                 snaplen = res;
2092 
2093         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2094                 goto drop_n_acct;
2095 
2096         if (skb_shared(skb)) {
2097                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2098                 if (nskb == NULL)
2099                         goto drop_n_acct;
2100 
2101                 if (skb_head != skb->data) {
2102                         skb->data = skb_head;
2103                         skb->len = skb_len;
2104                 }
2105                 consume_skb(skb);
2106                 skb = nskb;
2107         }
2108 
2109         sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2110 
2111         sll = &PACKET_SKB_CB(skb)->sa.ll;
2112         sll->sll_hatype = dev->type;
2113         sll->sll_pkttype = skb->pkt_type;
2114         if (unlikely(po->origdev))
2115                 sll->sll_ifindex = orig_dev->ifindex;
2116         else
2117                 sll->sll_ifindex = dev->ifindex;
2118 
2119         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2120 
2121         /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2122          * Use their space for storing the original skb length.
2123          */
2124         PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2125 
2126         if (pskb_trim(skb, snaplen))
2127                 goto drop_n_acct;
2128 
2129         skb_set_owner_r(skb, sk);
2130         skb->dev = NULL;
2131         skb_dst_drop(skb);
2132 
2133         /* drop conntrack reference */
2134         nf_reset_ct(skb);
2135 
2136         spin_lock(&sk->sk_receive_queue.lock);
2137         po->stats.stats1.tp_packets++;
2138         sock_skb_set_dropcount(sk, skb);
2139         __skb_queue_tail(&sk->sk_receive_queue, skb);
2140         spin_unlock(&sk->sk_receive_queue.lock);
2141         sk->sk_data_ready(sk);
2142         return 0;
2143 
2144 drop_n_acct:
2145         is_drop_n_account = true;
2146         atomic_inc(&po->tp_drops);
2147         atomic_inc(&sk->sk_drops);
2148 
2149 drop_n_restore:
2150         if (skb_head != skb->data && skb_shared(skb)) {
2151                 skb->data = skb_head;
2152                 skb->len = skb_len;
2153         }
2154 drop:
2155         if (!is_drop_n_account)
2156                 consume_skb(skb);
2157         else
2158                 kfree_skb(skb);
2159         return 0;
2160 }
2161 
2162 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2163                        struct packet_type *pt, struct net_device *orig_dev)
2164 {
2165         struct sock *sk;
2166         struct packet_sock *po;
2167         struct sockaddr_ll *sll;
2168         union tpacket_uhdr h;
2169         u8 *skb_head = skb->data;
2170         int skb_len = skb->len;
2171         unsigned int snaplen, res;
2172         unsigned long status = TP_STATUS_USER;
2173         unsigned short macoff, netoff, hdrlen;
2174         struct sk_buff *copy_skb = NULL;
2175         struct timespec64 ts;
2176         __u32 ts_status;
2177         bool is_drop_n_account = false;
2178         unsigned int slot_id = 0;
2179         bool do_vnet = false;
2180 
2181         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2182          * We may add members to them until current aligned size without forcing
2183          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2184          */
2185         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2186         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2187 
2188         if (skb->pkt_type == PACKET_LOOPBACK)
2189                 goto drop;
2190 
2191         sk = pt->af_packet_priv;
2192         po = pkt_sk(sk);
2193 
2194         if (!net_eq(dev_net(dev), sock_net(sk)))
2195                 goto drop;
2196 
2197         if (dev->header_ops) {
2198                 if (sk->sk_type != SOCK_DGRAM)
2199                         skb_push(skb, skb->data - skb_mac_header(skb));
2200                 else if (skb->pkt_type == PACKET_OUTGOING) {
2201                         /* Special case: outgoing packets have ll header at head */
2202                         skb_pull(skb, skb_network_offset(skb));
2203                 }
2204         }
2205 
2206         snaplen = skb->len;
2207 
2208         res = run_filter(skb, sk, snaplen);
2209         if (!res)
2210                 goto drop_n_restore;
2211 
2212         /* If we are flooded, just give up */
2213         if (__packet_rcv_has_room(po, skb) == ROOM_NONE) {
2214                 atomic_inc(&po->tp_drops);
2215                 goto drop_n_restore;
2216         }
2217 
2218         if (skb->ip_summed == CHECKSUM_PARTIAL)
2219                 status |= TP_STATUS_CSUMNOTREADY;
2220         else if (skb->pkt_type != PACKET_OUTGOING &&
2221                  (skb->ip_summed == CHECKSUM_COMPLETE ||
2222                   skb_csum_unnecessary(skb)))
2223                 status |= TP_STATUS_CSUM_VALID;
2224 
2225         if (snaplen > res)
2226                 snaplen = res;
2227 
2228         if (sk->sk_type == SOCK_DGRAM) {
2229                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2230                                   po->tp_reserve;
2231         } else {
2232                 unsigned int maclen = skb_network_offset(skb);
2233                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2234                                        (maclen < 16 ? 16 : maclen)) +
2235                                        po->tp_reserve;
2236                 if (po->has_vnet_hdr) {
2237                         netoff += sizeof(struct virtio_net_hdr);
2238                         do_vnet = true;
2239                 }
2240                 macoff = netoff - maclen;
2241         }
2242         if (po->tp_version <= TPACKET_V2) {
2243                 if (macoff + snaplen > po->rx_ring.frame_size) {
2244                         if (po->copy_thresh &&
2245                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2246                                 if (skb_shared(skb)) {
2247                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
2248                                 } else {
2249                                         copy_skb = skb_get(skb);
2250                                         skb_head = skb->data;
2251                                 }
2252                                 if (copy_skb)
2253                                         skb_set_owner_r(copy_skb, sk);
2254                         }
2255                         snaplen = po->rx_ring.frame_size - macoff;
2256                         if ((int)snaplen < 0) {
2257                                 snaplen = 0;
2258                                 do_vnet = false;
2259                         }
2260                 }
2261         } else if (unlikely(macoff + snaplen >
2262                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2263                 u32 nval;
2264 
2265                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2266                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2267                             snaplen, nval, macoff);
2268                 snaplen = nval;
2269                 if (unlikely((int)snaplen < 0)) {
2270                         snaplen = 0;
2271                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2272                         do_vnet = false;
2273                 }
2274         }
2275         spin_lock(&sk->sk_receive_queue.lock);
2276         h.raw = packet_current_rx_frame(po, skb,
2277                                         TP_STATUS_KERNEL, (macoff+snaplen));
2278         if (!h.raw)
2279                 goto drop_n_account;
2280 
2281         if (po->tp_version <= TPACKET_V2) {
2282                 slot_id = po->rx_ring.head;
2283                 if (test_bit(slot_id, po->rx_ring.rx_owner_map))
2284                         goto drop_n_account;
2285                 __set_bit(slot_id, po->rx_ring.rx_owner_map);
2286         }
2287 
2288         if (do_vnet &&
2289             virtio_net_hdr_from_skb(skb, h.raw + macoff -
2290                                     sizeof(struct virtio_net_hdr),
2291                                     vio_le(), true, 0)) {
2292                 if (po->tp_version == TPACKET_V3)
2293                         prb_clear_blk_fill_status(&po->rx_ring);
2294                 goto drop_n_account;
2295         }
2296 
2297         if (po->tp_version <= TPACKET_V2) {
2298                 packet_increment_rx_head(po, &po->rx_ring);
2299         /*
2300          * LOSING will be reported till you read the stats,
2301          * because it's COR - Clear On Read.
2302          * Anyways, moving it for V1/V2 only as V3 doesn't need this
2303          * at packet level.
2304          */
2305                 if (atomic_read(&po->tp_drops))
2306                         status |= TP_STATUS_LOSING;
2307         }
2308 
2309         po->stats.stats1.tp_packets++;
2310         if (copy_skb) {
2311                 status |= TP_STATUS_COPY;
2312                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2313         }
2314         spin_unlock(&sk->sk_receive_queue.lock);
2315 
2316         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2317 
2318         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2319                 ktime_get_real_ts64(&ts);
2320 
2321         status |= ts_status;
2322 
2323         switch (po->tp_version) {
2324         case TPACKET_V1:
2325                 h.h1->tp_len = skb->len;
2326                 h.h1->tp_snaplen = snaplen;
2327                 h.h1->tp_mac = macoff;
2328                 h.h1->tp_net = netoff;
2329                 h.h1->tp_sec = ts.tv_sec;
2330                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2331                 hdrlen = sizeof(*h.h1);
2332                 break;
2333         case TPACKET_V2:
2334                 h.h2->tp_len = skb->len;
2335                 h.h2->tp_snaplen = snaplen;
2336                 h.h2->tp_mac = macoff;
2337                 h.h2->tp_net = netoff;
2338                 h.h2->tp_sec = ts.tv_sec;
2339                 h.h2->tp_nsec = ts.tv_nsec;
2340                 if (skb_vlan_tag_present(skb)) {
2341                         h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2342                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2343                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2344                 } else {
2345                         h.h2->tp_vlan_tci = 0;
2346                         h.h2->tp_vlan_tpid = 0;
2347                 }
2348                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2349                 hdrlen = sizeof(*h.h2);
2350                 break;
2351         case TPACKET_V3:
2352                 /* tp_nxt_offset,vlan are already populated above.
2353                  * So DONT clear those fields here
2354                  */
2355                 h.h3->tp_status |= status;
2356                 h.h3->tp_len = skb->len;
2357                 h.h3->tp_snaplen = snaplen;
2358                 h.h3->tp_mac = macoff;
2359                 h.h3->tp_net = netoff;
2360                 h.h3->tp_sec  = ts.tv_sec;
2361                 h.h3->tp_nsec = ts.tv_nsec;
2362                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2363                 hdrlen = sizeof(*h.h3);
2364                 break;
2365         default:
2366                 BUG();
2367         }
2368 
2369         sll = h.raw + TPACKET_ALIGN(hdrlen);
2370         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2371         sll->sll_family = AF_PACKET;
2372         sll->sll_hatype = dev->type;
2373         sll->sll_protocol = skb->protocol;
2374         sll->sll_pkttype = skb->pkt_type;
2375         if (unlikely(po->origdev))
2376                 sll->sll_ifindex = orig_dev->ifindex;
2377         else
2378                 sll->sll_ifindex = dev->ifindex;
2379 
2380         smp_mb();
2381 
2382 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2383         if (po->tp_version <= TPACKET_V2) {
2384                 u8 *start, *end;
2385 
2386                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2387                                         macoff + snaplen);
2388 
2389                 for (start = h.raw; start < end; start += PAGE_SIZE)
2390                         flush_dcache_page(pgv_to_page(start));
2391         }
2392         smp_wmb();
2393 #endif
2394 
2395         if (po->tp_version <= TPACKET_V2) {
2396                 spin_lock(&sk->sk_receive_queue.lock);
2397                 __packet_set_status(po, h.raw, status);
2398                 __clear_bit(slot_id, po->rx_ring.rx_owner_map);
2399                 spin_unlock(&sk->sk_receive_queue.lock);
2400                 sk->sk_data_ready(sk);
2401         } else if (po->tp_version == TPACKET_V3) {
2402                 prb_clear_blk_fill_status(&po->rx_ring);
2403         }
2404 
2405 drop_n_restore:
2406         if (skb_head != skb->data && skb_shared(skb)) {
2407                 skb->data = skb_head;
2408                 skb->len = skb_len;
2409         }
2410 drop:
2411         if (!is_drop_n_account)
2412                 consume_skb(skb);
2413         else
2414                 kfree_skb(skb);
2415         return 0;
2416 
2417 drop_n_account:
2418         spin_unlock(&sk->sk_receive_queue.lock);
2419         atomic_inc(&po->tp_drops);
2420         is_drop_n_account = true;
2421 
2422         sk->sk_data_ready(sk);
2423         kfree_skb(copy_skb);
2424         goto drop_n_restore;
2425 }
2426 
2427 static void tpacket_destruct_skb(struct sk_buff *skb)
2428 {
2429         struct packet_sock *po = pkt_sk(skb->sk);
2430 
2431         if (likely(po->tx_ring.pg_vec)) {
2432                 void *ph;
2433                 __u32 ts;
2434 
2435                 ph = skb_zcopy_get_nouarg(skb);
2436                 packet_dec_pending(&po->tx_ring);
2437 
2438                 ts = __packet_set_timestamp(po, ph, skb);
2439                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2440 
2441                 if (!packet_read_pending(&po->tx_ring))
2442                         complete(&po->skb_completion);
2443         }
2444 
2445         sock_wfree(skb);
2446 }
2447 
2448 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2449 {
2450         if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2451             (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2452              __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2453               __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2454                 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2455                          __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2456                         __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2457 
2458         if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2459                 return -EINVAL;
2460 
2461         return 0;
2462 }
2463 
2464 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2465                                  struct virtio_net_hdr *vnet_hdr)
2466 {
2467         if (*len < sizeof(*vnet_hdr))
2468                 return -EINVAL;
2469         *len -= sizeof(*vnet_hdr);
2470 
2471         if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2472                 return -EFAULT;
2473 
2474         return __packet_snd_vnet_parse(vnet_hdr, *len);
2475 }
2476 
2477 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2478                 void *frame, struct net_device *dev, void *data, int tp_len,
2479                 __be16 proto, unsigned char *addr, int hlen, int copylen,
2480                 const struct sockcm_cookie *sockc)
2481 {
2482         union tpacket_uhdr ph;
2483         int to_write, offset, len, nr_frags, len_max;
2484         struct socket *sock = po->sk.sk_socket;
2485         struct page *page;
2486         int err;
2487 
2488         ph.raw = frame;
2489 
2490         skb->protocol = proto;
2491         skb->dev = dev;
2492         skb->priority = po->sk.sk_priority;
2493         skb->mark = po->sk.sk_mark;
2494         skb->tstamp = sockc->transmit_time;
2495         skb_setup_tx_timestamp(skb, sockc->tsflags);
2496         skb_zcopy_set_nouarg(skb, ph.raw);
2497 
2498         skb_reserve(skb, hlen);
2499         skb_reset_network_header(skb);
2500 
2501         to_write = tp_len;
2502 
2503         if (sock->type == SOCK_DGRAM) {
2504                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2505                                 NULL, tp_len);
2506                 if (unlikely(err < 0))
2507                         return -EINVAL;
2508         } else if (copylen) {
2509                 int hdrlen = min_t(int, copylen, tp_len);
2510 
2511                 skb_push(skb, dev->hard_header_len);
2512                 skb_put(skb, copylen - dev->hard_header_len);
2513                 err = skb_store_bits(skb, 0, data, hdrlen);
2514                 if (unlikely(err))
2515                         return err;
2516                 if (!dev_validate_header(dev, skb->data, hdrlen))
2517                         return -EINVAL;
2518 
2519                 data += hdrlen;
2520                 to_write -= hdrlen;
2521         }
2522 
2523         offset = offset_in_page(data);
2524         len_max = PAGE_SIZE - offset;
2525         len = ((to_write > len_max) ? len_max : to_write);
2526 
2527         skb->data_len = to_write;
2528         skb->len += to_write;
2529         skb->truesize += to_write;
2530         refcount_add(to_write, &po->sk.sk_wmem_alloc);
2531 
2532         while (likely(to_write)) {
2533                 nr_frags = skb_shinfo(skb)->nr_frags;
2534 
2535                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2536                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2537                                MAX_SKB_FRAGS);
2538                         return -EFAULT;
2539                 }
2540 
2541                 page = pgv_to_page(data);
2542                 data += len;
2543                 flush_dcache_page(page);
2544                 get_page(page);
2545                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2546                 to_write -= len;
2547                 offset = 0;
2548                 len_max = PAGE_SIZE;
2549                 len = ((to_write > len_max) ? len_max : to_write);
2550         }
2551 
2552         packet_parse_headers(skb, sock);
2553 
2554         return tp_len;
2555 }
2556 
2557 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2558                                 int size_max, void **data)
2559 {
2560         union tpacket_uhdr ph;
2561         int tp_len, off;
2562 
2563         ph.raw = frame;
2564 
2565         switch (po->tp_version) {
2566         case TPACKET_V3:
2567                 if (ph.h3->tp_next_offset != 0) {
2568                         pr_warn_once("variable sized slot not supported");
2569                         return -EINVAL;
2570                 }
2571                 tp_len = ph.h3->tp_len;
2572                 break;
2573         case TPACKET_V2:
2574                 tp_len = ph.h2->tp_len;
2575                 break;
2576         default:
2577                 tp_len = ph.h1->tp_len;
2578                 break;
2579         }
2580         if (unlikely(tp_len > size_max)) {
2581                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2582                 return -EMSGSIZE;
2583         }
2584 
2585         if (unlikely(po->tp_tx_has_off)) {
2586                 int off_min, off_max;
2587 
2588                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2589                 off_max = po->tx_ring.frame_size - tp_len;
2590                 if (po->sk.sk_type == SOCK_DGRAM) {
2591                         switch (po->tp_version) {
2592                         case TPACKET_V3:
2593                                 off = ph.h3->tp_net;
2594                                 break;
2595                         case TPACKET_V2:
2596                                 off = ph.h2->tp_net;
2597                                 break;
2598                         default:
2599                                 off = ph.h1->tp_net;
2600                                 break;
2601                         }
2602                 } else {
2603                         switch (po->tp_version) {
2604                         case TPACKET_V3:
2605                                 off = ph.h3->tp_mac;
2606                                 break;
2607                         case TPACKET_V2:
2608                                 off = ph.h2->tp_mac;
2609                                 break;
2610                         default:
2611                                 off = ph.h1->tp_mac;
2612                                 break;
2613                         }
2614                 }
2615                 if (unlikely((off < off_min) || (off_max < off)))
2616                         return -EINVAL;
2617         } else {
2618                 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2619         }
2620 
2621         *data = frame + off;
2622         return tp_len;
2623 }
2624 
2625 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2626 {
2627         struct sk_buff *skb = NULL;
2628         struct net_device *dev;
2629         struct virtio_net_hdr *vnet_hdr = NULL;
2630         struct sockcm_cookie sockc;
2631         __be16 proto;
2632         int err, reserve = 0;
2633         void *ph;
2634         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2635         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2636         unsigned char *addr = NULL;
2637         int tp_len, size_max;
2638         void *data;
2639         int len_sum = 0;
2640         int status = TP_STATUS_AVAILABLE;
2641         int hlen, tlen, copylen = 0;
2642         long timeo = 0;
2643 
2644         mutex_lock(&po->pg_vec_lock);
2645 
2646         /* packet_sendmsg() check on tx_ring.pg_vec was lockless,
2647          * we need to confirm it under protection of pg_vec_lock.
2648          */
2649         if (unlikely(!po->tx_ring.pg_vec)) {
2650                 err = -EBUSY;
2651                 goto out;
2652         }
2653         if (likely(saddr == NULL)) {
2654                 dev     = packet_cached_dev_get(po);
2655                 proto   = po->num;
2656         } else {
2657                 err = -EINVAL;
2658                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2659                         goto out;
2660                 if (msg->msg_namelen < (saddr->sll_halen
2661                                         + offsetof(struct sockaddr_ll,
2662                                                 sll_addr)))
2663                         goto out;
2664                 proto   = saddr->sll_protocol;
2665                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2666                 if (po->sk.sk_socket->type == SOCK_DGRAM) {
2667                         if (dev && msg->msg_namelen < dev->addr_len +
2668                                    offsetof(struct sockaddr_ll, sll_addr))
2669                                 goto out_put;
2670                         addr = saddr->sll_addr;
2671                 }
2672         }
2673 
2674         err = -ENXIO;
2675         if (unlikely(dev == NULL))
2676                 goto out;
2677         err = -ENETDOWN;
2678         if (unlikely(!(dev->flags & IFF_UP)))
2679                 goto out_put;
2680 
2681         sockcm_init(&sockc, &po->sk);
2682         if (msg->msg_controllen) {
2683                 err = sock_cmsg_send(&po->sk, msg, &sockc);
2684                 if (unlikely(err))
2685                         goto out_put;
2686         }
2687 
2688         if (po->sk.sk_socket->type == SOCK_RAW)
2689                 reserve = dev->hard_header_len;
2690         size_max = po->tx_ring.frame_size
2691                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2692 
2693         if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2694                 size_max = dev->mtu + reserve + VLAN_HLEN;
2695 
2696         reinit_completion(&po->skb_completion);
2697 
2698         do {
2699                 ph = packet_current_frame(po, &po->tx_ring,
2700                                           TP_STATUS_SEND_REQUEST);
2701                 if (unlikely(ph == NULL)) {
2702                         if (need_wait && skb) {
2703                                 timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT);
2704                                 timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo);
2705                                 if (timeo <= 0) {
2706                                         err = !timeo ? -ETIMEDOUT : -ERESTARTSYS;
2707                                         goto out_put;
2708                                 }
2709                         }
2710                         /* check for additional frames */
2711                         continue;
2712                 }
2713 
2714                 skb = NULL;
2715                 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2716                 if (tp_len < 0)
2717                         goto tpacket_error;
2718 
2719                 status = TP_STATUS_SEND_REQUEST;
2720                 hlen = LL_RESERVED_SPACE(dev);
2721                 tlen = dev->needed_tailroom;
2722                 if (po->has_vnet_hdr) {
2723                         vnet_hdr = data;
2724                         data += sizeof(*vnet_hdr);
2725                         tp_len -= sizeof(*vnet_hdr);
2726                         if (tp_len < 0 ||
2727                             __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2728                                 tp_len = -EINVAL;
2729                                 goto tpacket_error;
2730                         }
2731                         copylen = __virtio16_to_cpu(vio_le(),
2732                                                     vnet_hdr->hdr_len);
2733                 }
2734                 copylen = max_t(int, copylen, dev->hard_header_len);
2735                 skb = sock_alloc_send_skb(&po->sk,
2736                                 hlen + tlen + sizeof(struct sockaddr_ll) +
2737                                 (copylen - dev->hard_header_len),
2738                                 !need_wait, &err);
2739 
2740                 if (unlikely(skb == NULL)) {
2741                         /* we assume the socket was initially writeable ... */
2742                         if (likely(len_sum > 0))
2743                                 err = len_sum;
2744                         goto out_status;
2745                 }
2746                 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2747                                           addr, hlen, copylen, &sockc);
2748                 if (likely(tp_len >= 0) &&
2749                     tp_len > dev->mtu + reserve &&
2750                     !po->has_vnet_hdr &&
2751                     !packet_extra_vlan_len_allowed(dev, skb))
2752                         tp_len = -EMSGSIZE;
2753 
2754                 if (unlikely(tp_len < 0)) {
2755 tpacket_error:
2756                         if (po->tp_loss) {
2757                                 __packet_set_status(po, ph,
2758                                                 TP_STATUS_AVAILABLE);
2759                                 packet_increment_head(&po->tx_ring);
2760                                 kfree_skb(skb);
2761                                 continue;
2762                         } else {
2763                                 status = TP_STATUS_WRONG_FORMAT;
2764                                 err = tp_len;
2765                                 goto out_status;
2766                         }
2767                 }
2768 
2769                 if (po->has_vnet_hdr) {
2770                         if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) {
2771                                 tp_len = -EINVAL;
2772                                 goto tpacket_error;
2773                         }
2774                         virtio_net_hdr_set_proto(skb, vnet_hdr);
2775                 }
2776 
2777                 skb->destructor = tpacket_destruct_skb;
2778                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2779                 packet_inc_pending(&po->tx_ring);
2780 
2781                 status = TP_STATUS_SEND_REQUEST;
2782                 err = po->xmit(skb);
2783                 if (unlikely(err > 0)) {
2784                         err = net_xmit_errno(err);
2785                         if (err && __packet_get_status(po, ph) ==
2786                                    TP_STATUS_AVAILABLE) {
2787                                 /* skb was destructed already */
2788                                 skb = NULL;
2789                                 goto out_status;
2790                         }
2791                         /*
2792                          * skb was dropped but not destructed yet;
2793                          * let's treat it like congestion or err < 0
2794                          */
2795                         err = 0;
2796                 }
2797                 packet_increment_head(&po->tx_ring);
2798                 len_sum += tp_len;
2799         } while (likely((ph != NULL) ||
2800                 /* Note: packet_read_pending() might be slow if we have
2801                  * to call it as it's per_cpu variable, but in fast-path
2802                  * we already short-circuit the loop with the first
2803                  * condition, and luckily don't have to go that path
2804                  * anyway.
2805                  */
2806                  (need_wait && packet_read_pending(&po->tx_ring))));
2807 
2808         err = len_sum;
2809         goto out_put;
2810 
2811 out_status:
2812         __packet_set_status(po, ph, status);
2813         kfree_skb(skb);
2814 out_put:
2815         dev_put(dev);
2816 out:
2817         mutex_unlock(&po->pg_vec_lock);
2818         return err;
2819 }
2820 
2821 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2822                                         size_t reserve, size_t len,
2823                                         size_t linear, int noblock,
2824                                         int *err)
2825 {
2826         struct sk_buff *skb;
2827 
2828         /* Under a page?  Don't bother with paged skb. */
2829         if (prepad + len < PAGE_SIZE || !linear)
2830                 linear = len;
2831 
2832         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2833                                    err, 0);
2834         if (!skb)
2835                 return NULL;
2836 
2837         skb_reserve(skb, reserve);
2838         skb_put(skb, linear);
2839         skb->data_len = len - linear;
2840         skb->len += len - linear;
2841 
2842         return skb;
2843 }
2844 
2845 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2846 {
2847         struct sock *sk = sock->sk;
2848         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2849         struct sk_buff *skb;
2850         struct net_device *dev;
2851         __be16 proto;
2852         unsigned char *addr = NULL;
2853         int err, reserve = 0;
2854         struct sockcm_cookie sockc;
2855         struct virtio_net_hdr vnet_hdr = { 0 };
2856         int offset = 0;
2857         struct packet_sock *po = pkt_sk(sk);
2858         bool has_vnet_hdr = false;
2859         int hlen, tlen, linear;
2860         int extra_len = 0;
2861 
2862         /*
2863          *      Get and verify the address.
2864          */
2865 
2866         if (likely(saddr == NULL)) {
2867                 dev     = packet_cached_dev_get(po);
2868                 proto   = po->num;
2869         } else {
2870                 err = -EINVAL;
2871                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2872                         goto out;
2873                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2874                         goto out;
2875                 proto   = saddr->sll_protocol;
2876                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2877                 if (sock->type == SOCK_DGRAM) {
2878                         if (dev && msg->msg_namelen < dev->addr_len +
2879                                    offsetof(struct sockaddr_ll, sll_addr))
2880                                 goto out_unlock;
2881                         addr = saddr->sll_addr;
2882                 }
2883         }
2884 
2885         err = -ENXIO;
2886         if (unlikely(dev == NULL))
2887                 goto out_unlock;
2888         err = -ENETDOWN;
2889         if (unlikely(!(dev->flags & IFF_UP)))
2890                 goto out_unlock;
2891 
2892         sockcm_init(&sockc, sk);
2893         sockc.mark = sk->sk_mark;
2894         if (msg->msg_controllen) {
2895                 err = sock_cmsg_send(sk, msg, &sockc);
2896                 if (unlikely(err))
2897                         goto out_unlock;
2898         }
2899 
2900         if (sock->type == SOCK_RAW)
2901                 reserve = dev->hard_header_len;
2902         if (po->has_vnet_hdr) {
2903                 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2904                 if (err)
2905                         goto out_unlock;
2906                 has_vnet_hdr = true;
2907         }
2908 
2909         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2910                 if (!netif_supports_nofcs(dev)) {
2911                         err = -EPROTONOSUPPORT;
2912                         goto out_unlock;
2913                 }
2914                 extra_len = 4; /* We're doing our own CRC */
2915         }
2916 
2917         err = -EMSGSIZE;
2918         if (!vnet_hdr.gso_type &&
2919             (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2920                 goto out_unlock;
2921 
2922         err = -ENOBUFS;
2923         hlen = LL_RESERVED_SPACE(dev);
2924         tlen = dev->needed_tailroom;
2925         linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2926         linear = max(linear, min_t(int, len, dev->hard_header_len));
2927         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2928                                msg->msg_flags & MSG_DONTWAIT, &err);
2929         if (skb == NULL)
2930                 goto out_unlock;
2931 
2932         skb_reset_network_header(skb);
2933 
2934         err = -EINVAL;
2935         if (sock->type == SOCK_DGRAM) {
2936                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2937                 if (unlikely(offset < 0))
2938                         goto out_free;
2939         } else if (reserve) {
2940                 skb_reserve(skb, -reserve);
2941                 if (len < reserve + sizeof(struct ipv6hdr) &&
2942                     dev->min_header_len != dev->hard_header_len)
2943                         skb_reset_network_header(skb);
2944         }
2945 
2946         /* Returns -EFAULT on error */
2947         err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2948         if (err)
2949                 goto out_free;
2950 
2951         if (sock->type == SOCK_RAW &&
2952             !dev_validate_header(dev, skb->data, len)) {
2953                 err = -EINVAL;
2954                 goto out_free;
2955         }
2956 
2957         skb_setup_tx_timestamp(skb, sockc.tsflags);
2958 
2959         if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2960             !packet_extra_vlan_len_allowed(dev, skb)) {
2961                 err = -EMSGSIZE;
2962                 goto out_free;
2963         }
2964 
2965         skb->protocol = proto;
2966         skb->dev = dev;
2967         skb->priority = sk->sk_priority;
2968         skb->mark = sockc.mark;
2969         skb->tstamp = sockc.transmit_time;
2970 
2971         if (has_vnet_hdr) {
2972                 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2973                 if (err)
2974                         goto out_free;
2975                 len += sizeof(vnet_hdr);
2976                 virtio_net_hdr_set_proto(skb, &vnet_hdr);
2977         }
2978 
2979         packet_parse_headers(skb, sock);
2980 
2981         if (unlikely(extra_len == 4))
2982                 skb->no_fcs = 1;
2983 
2984         err = po->xmit(skb);
2985         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2986                 goto out_unlock;
2987 
2988         dev_put(dev);
2989 
2990         return len;
2991 
2992 out_free:
2993         kfree_skb(skb);
2994 out_unlock:
2995         if (dev)
2996                 dev_put(dev);
2997 out:
2998         return err;
2999 }
3000 
3001 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
3002 {
3003         struct sock *sk = sock->sk;
3004         struct packet_sock *po = pkt_sk(sk);
3005 
3006         if (po->tx_ring.pg_vec)
3007                 return tpacket_snd(po, msg);
3008         else
3009                 return packet_snd(sock, msg, len);
3010 }
3011 
3012 /*
3013  *      Close a PACKET socket. This is fairly simple. We immediately go
3014  *      to 'closed' state and remove our protocol entry in the device list.
3015  */
3016 
3017 static int packet_release(struct socket *sock)
3018 {
3019         struct sock *sk = sock->sk;
3020         struct packet_sock *po;
3021         struct packet_fanout *f;
3022         struct net *net;
3023         union tpacket_req_u req_u;
3024 
3025         if (!sk)
3026                 return 0;
3027 
3028         net = sock_net(sk);
3029         po = pkt_sk(sk);
3030 
3031         mutex_lock(&net->packet.sklist_lock);
3032         sk_del_node_init_rcu(sk);
3033         mutex_unlock(&net->packet.sklist_lock);
3034 
3035         preempt_disable();
3036         sock_prot_inuse_add(net, sk->sk_prot, -1);
3037         preempt_enable();
3038 
3039         spin_lock(&po->bind_lock);
3040         unregister_prot_hook(sk, false);
3041         packet_cached_dev_reset(po);
3042 
3043         if (po->prot_hook.dev) {
3044                 dev_put(po->prot_hook.dev);
3045                 po->prot_hook.dev = NULL;
3046         }
3047         spin_unlock(&po->bind_lock);
3048 
3049         packet_flush_mclist(sk);
3050 
3051         lock_sock(sk);
3052         if (po->rx_ring.pg_vec) {
3053                 memset(&req_u, 0, sizeof(req_u));
3054                 packet_set_ring(sk, &req_u, 1, 0);
3055         }
3056 
3057         if (po->tx_ring.pg_vec) {
3058                 memset(&req_u, 0, sizeof(req_u));
3059                 packet_set_ring(sk, &req_u, 1, 1);
3060         }
3061         release_sock(sk);
3062 
3063         f = fanout_release(sk);
3064 
3065         synchronize_net();
3066 
3067         kfree(po->rollover);
3068         if (f) {
3069                 fanout_release_data(f);
3070                 kfree(f);
3071         }
3072         /*
3073          *      Now the socket is dead. No more input will appear.
3074          */
3075         sock_orphan(sk);
3076         sock->sk = NULL;
3077 
3078         /* Purge queues */
3079 
3080         skb_queue_purge(&sk->sk_receive_queue);
3081         packet_free_pending(po);
3082         sk_refcnt_debug_release(sk);
3083 
3084         sock_put(sk);
3085         return 0;
3086 }
3087 
3088 /*
3089  *      Attach a packet hook.
3090  */
3091 
3092 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3093                           __be16 proto)
3094 {
3095         struct packet_sock *po = pkt_sk(sk);
3096         struct net_device *dev_curr;
3097         __be16 proto_curr;
3098         bool need_rehook;
3099         struct net_device *dev = NULL;
3100         int ret = 0;
3101         bool unlisted = false;
3102 
3103         lock_sock(sk);
3104         spin_lock(&po->bind_lock);
3105         rcu_read_lock();
3106 
3107         if (po->fanout) {
3108                 ret = -EINVAL;
3109                 goto out_unlock;
3110         }
3111 
3112         if (name) {
3113                 dev = dev_get_by_name_rcu(sock_net(sk), name);
3114                 if (!dev) {
3115                         ret = -ENODEV;
3116                         goto out_unlock;
3117                 }
3118         } else if (ifindex) {
3119                 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3120                 if (!dev) {
3121                         ret = -ENODEV;
3122                         goto out_unlock;
3123                 }
3124         }
3125 
3126         if (dev)
3127                 dev_hold(dev);
3128 
3129         proto_curr = po->prot_hook.type;
3130         dev_curr = po->prot_hook.dev;
3131 
3132         need_rehook = proto_curr != proto || dev_curr != dev;
3133 
3134         if (need_rehook) {
3135                 if (po->running) {
3136                         rcu_read_unlock();
3137                         /* prevents packet_notifier() from calling
3138                          * register_prot_hook()
3139                          */
3140                         po->num = 0;
3141                         __unregister_prot_hook(sk, true);
3142                         rcu_read_lock();
3143                         dev_curr = po->prot_hook.dev;
3144                         if (dev)
3145                                 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3146                                                                  dev->ifindex);
3147                 }
3148 
3149                 BUG_ON(po->running);
3150                 po->num = proto;
3151                 po->prot_hook.type = proto;
3152 
3153                 if (unlikely(unlisted)) {
3154                         dev_put(dev);
3155                         po->prot_hook.dev = NULL;
3156                         po->ifindex = -1;
3157                         packet_cached_dev_reset(po);
3158                 } else {
3159                         po->prot_hook.dev = dev;
3160                         po->ifindex = dev ? dev->ifindex : 0;
3161                         packet_cached_dev_assign(po, dev);
3162                 }
3163         }
3164         if (dev_curr)
3165                 dev_put(dev_curr);
3166 
3167         if (proto == 0 || !need_rehook)
3168                 goto out_unlock;
3169 
3170         if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3171                 register_prot_hook(sk);
3172         } else {
3173                 sk->sk_err = ENETDOWN;
3174                 if (!sock_flag(sk, SOCK_DEAD))
3175                         sk->sk_error_report(sk);
3176         }
3177 
3178 out_unlock:
3179         rcu_read_unlock();
3180         spin_unlock(&po->bind_lock);
3181         release_sock(sk);
3182         return ret;
3183 }
3184 
3185 /*
3186  *      Bind a packet socket to a device
3187  */
3188 
3189 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3190                             int addr_len)
3191 {
3192         struct sock *sk = sock->sk;
3193         char name[sizeof(uaddr->sa_data) + 1];
3194 
3195         /*
3196          *      Check legality
3197          */
3198 
3199         if (addr_len != sizeof(struct sockaddr))
3200                 return -EINVAL;
3201         /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
3202          * zero-terminated.
3203          */
3204         memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
3205         name[sizeof(uaddr->sa_data)] = 0;
3206 
3207         return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3208 }
3209 
3210 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3211 {
3212         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3213         struct sock *sk = sock->sk;
3214 
3215         /*
3216          *      Check legality
3217          */
3218 
3219         if (addr_len < sizeof(struct sockaddr_ll))
3220                 return -EINVAL;
3221         if (sll->sll_family != AF_PACKET)
3222                 return -EINVAL;
3223 
3224         return packet_do_bind(sk, NULL, sll->sll_ifindex,
3225                               sll->sll_protocol ? : pkt_sk(sk)->num);
3226 }
3227 
3228 static struct proto packet_proto = {
3229         .name     = "PACKET",
3230         .owner    = THIS_MODULE,
3231         .obj_size = sizeof(struct packet_sock),
3232 };
3233 
3234 /*
3235  *      Create a packet of type SOCK_PACKET.
3236  */
3237 
3238 static int packet_create(struct net *net, struct socket *sock, int protocol,
3239                          int kern)
3240 {
3241         struct sock *sk;
3242         struct packet_sock *po;
3243         __be16 proto = (__force __be16)protocol; /* weird, but documented */
3244         int err;
3245 
3246         if (!ns_capable(net->user_ns, CAP_NET_RAW))
3247                 return -EPERM;
3248         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3249             sock->type != SOCK_PACKET)
3250                 return -ESOCKTNOSUPPORT;
3251 
3252         sock->state = SS_UNCONNECTED;
3253 
3254         err = -ENOBUFS;
3255         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3256         if (sk == NULL)
3257                 goto out;
3258 
3259         sock->ops = &packet_ops;
3260         if (sock->type == SOCK_PACKET)
3261                 sock->ops = &packet_ops_spkt;
3262 
3263         sock_init_data(sock, sk);
3264 
3265         po = pkt_sk(sk);
3266         init_completion(&po->skb_completion);
3267         sk->sk_family = PF_PACKET;
3268         po->num = proto;
3269         po->xmit = dev_queue_xmit;
3270 
3271         err = packet_alloc_pending(po);
3272         if (err)
3273                 goto out2;
3274 
3275         packet_cached_dev_reset(po);
3276 
3277         sk->sk_destruct = packet_sock_destruct;
3278         sk_refcnt_debug_inc(sk);
3279 
3280         /*
3281          *      Attach a protocol block
3282          */
3283 
3284         spin_lock_init(&po->bind_lock);
3285         mutex_init(&po->pg_vec_lock);
3286         po->rollover = NULL;
3287         po->prot_hook.func = packet_rcv;
3288 
3289         if (sock->type == SOCK_PACKET)
3290                 po->prot_hook.func = packet_rcv_spkt;
3291 
3292         po->prot_hook.af_packet_priv = sk;
3293 
3294         if (proto) {
3295                 po->prot_hook.type = proto;
3296                 __register_prot_hook(sk);
3297         }
3298 
3299         mutex_lock(&net->packet.sklist_lock);
3300         sk_add_node_tail_rcu(sk, &net->packet.sklist);
3301         mutex_unlock(&net->packet.sklist_lock);
3302 
3303         preempt_disable();
3304         sock_prot_inuse_add(net, &packet_proto, 1);
3305         preempt_enable();
3306 
3307         return 0;
3308 out2:
3309         sk_free(sk);
3310 out:
3311         return err;
3312 }
3313 
3314 /*
3315  *      Pull a packet from our receive queue and hand it to the user.
3316  *      If necessary we block.
3317  */
3318 
3319 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3320                           int flags)
3321 {
3322         struct sock *sk = sock->sk;
3323         struct sk_buff *skb;
3324         int copied, err;
3325         int vnet_hdr_len = 0;
3326         unsigned int origlen = 0;
3327 
3328         err = -EINVAL;
3329         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3330                 goto out;
3331 
3332 #if 0
3333         /* What error should we return now? EUNATTACH? */
3334         if (pkt_sk(sk)->ifindex < 0)
3335                 return -ENODEV;
3336 #endif
3337 
3338         if (flags & MSG_ERRQUEUE) {
3339                 err = sock_recv_errqueue(sk, msg, len,
3340                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
3341                 goto out;
3342         }
3343 
3344         /*
3345          *      Call the generic datagram receiver. This handles all sorts
3346          *      of horrible races and re-entrancy so we can forget about it
3347          *      in the protocol layers.
3348          *
3349          *      Now it will return ENETDOWN, if device have just gone down,
3350          *      but then it will block.
3351          */
3352 
3353         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3354 
3355         /*
3356          *      An error occurred so return it. Because skb_recv_datagram()
3357          *      handles the blocking we don't see and worry about blocking
3358          *      retries.
3359          */
3360 
3361         if (skb == NULL)
3362                 goto out;
3363 
3364         packet_rcv_try_clear_pressure(pkt_sk(sk));
3365 
3366         if (pkt_sk(sk)->has_vnet_hdr) {
3367                 err = packet_rcv_vnet(msg, skb, &len);
3368                 if (err)
3369                         goto out_free;
3370                 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3371         }
3372 
3373         /* You lose any data beyond the buffer you gave. If it worries
3374          * a user program they can ask the device for its MTU
3375          * anyway.
3376          */
3377         copied = skb->len;
3378         if (copied > len) {
3379                 copied = len;
3380                 msg->msg_flags |= MSG_TRUNC;
3381         }
3382 
3383         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3384         if (err)
3385                 goto out_free;
3386 
3387         if (sock->type != SOCK_PACKET) {
3388                 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3389 
3390                 /* Original length was stored in sockaddr_ll fields */
3391                 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3392                 sll->sll_family = AF_PACKET;
3393                 sll->sll_protocol = skb->protocol;
3394         }
3395 
3396         sock_recv_ts_and_drops(msg, sk, skb);
3397 
3398         if (msg->msg_name) {
3399                 int copy_len;
3400 
3401                 /* If the address length field is there to be filled
3402                  * in, we fill it in now.
3403                  */
3404                 if (sock->type == SOCK_PACKET) {
3405                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3406                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
3407                         copy_len = msg->msg_namelen;
3408                 } else {
3409                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3410 
3411                         msg->msg_namelen = sll->sll_halen +
3412                                 offsetof(struct sockaddr_ll, sll_addr);
3413                         copy_len = msg->msg_namelen;
3414                         if (msg->msg_namelen < sizeof(struct sockaddr_ll)) {
3415                                 memset(msg->msg_name +
3416                                        offsetof(struct sockaddr_ll, sll_addr),
3417                                        0, sizeof(sll->sll_addr));
3418                                 msg->msg_namelen = sizeof(struct sockaddr_ll);
3419                         }
3420                 }
3421                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
3422         }
3423 
3424         if (pkt_sk(sk)->auxdata) {
3425                 struct tpacket_auxdata aux;
3426 
3427                 aux.tp_status = TP_STATUS_USER;
3428                 if (skb->ip_summed == CHECKSUM_PARTIAL)
3429                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3430                 else if (skb->pkt_type != PACKET_OUTGOING &&
3431                          (skb->ip_summed == CHECKSUM_COMPLETE ||
3432                           skb_csum_unnecessary(skb)))
3433                         aux.tp_status |= TP_STATUS_CSUM_VALID;
3434 
3435                 aux.tp_len = origlen;
3436                 aux.tp_snaplen = skb->len;
3437                 aux.tp_mac = 0;
3438                 aux.tp_net = skb_network_offset(skb);
3439                 if (skb_vlan_tag_present(skb)) {
3440                         aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3441                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3442                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3443                 } else {
3444                         aux.tp_vlan_tci = 0;
3445                         aux.tp_vlan_tpid = 0;
3446                 }
3447                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3448         }
3449 
3450         /*
3451          *      Free or return the buffer as appropriate. Again this
3452          *      hides all the races and re-entrancy issues from us.
3453          */
3454         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3455 
3456 out_free:
3457         skb_free_datagram(sk, skb);
3458 out:
3459         return err;
3460 }
3461 
3462 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3463                                int peer)
3464 {
3465         struct net_device *dev;
3466         struct sock *sk = sock->sk;
3467 
3468         if (peer)
3469                 return -EOPNOTSUPP;
3470 
3471         uaddr->sa_family = AF_PACKET;
3472         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3473         rcu_read_lock();
3474         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3475         if (dev)
3476                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3477         rcu_read_unlock();
3478 
3479         return sizeof(*uaddr);
3480 }
3481 
3482 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3483                           int peer)
3484 {
3485         struct net_device *dev;
3486         struct sock *sk = sock->sk;
3487         struct packet_sock *po = pkt_sk(sk);
3488         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3489 
3490         if (peer)
3491                 return -EOPNOTSUPP;
3492 
3493         sll->sll_family = AF_PACKET;
3494         sll->sll_ifindex = po->ifindex;
3495         sll->sll_protocol = po->num;
3496         sll->sll_pkttype = 0;
3497         rcu_read_lock();
3498         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3499         if (dev) {
3500                 sll->sll_hatype = dev->type;
3501                 sll->sll_halen = dev->addr_len;
3502                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3503         } else {
3504                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3505                 sll->sll_halen = 0;
3506         }
3507         rcu_read_unlock();
3508 
3509         return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3510 }
3511 
3512 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3513                          int what)
3514 {
3515         switch (i->type) {
3516         case PACKET_MR_MULTICAST:
3517                 if (i->alen != dev->addr_len)
3518                         return -EINVAL;
3519                 if (what > 0)
3520                         return dev_mc_add(dev, i->addr);
3521                 else
3522                         return dev_mc_del(dev, i->addr);
3523                 break;
3524         case PACKET_MR_PROMISC:
3525                 return dev_set_promiscuity(dev, what);
3526         case PACKET_MR_ALLMULTI:
3527                 return dev_set_allmulti(dev, what);
3528         case PACKET_MR_UNICAST:
3529                 if (i->alen != dev->addr_len)
3530                         return -EINVAL;
3531                 if (what > 0)
3532                         return dev_uc_add(dev, i->addr);
3533                 else
3534                         return dev_uc_del(dev, i->addr);
3535                 break;
3536         default:
3537                 break;
3538         }
3539         return 0;
3540 }
3541 
3542 static void packet_dev_mclist_delete(struct net_device *dev,
3543                                      struct packet_mclist **mlp)
3544 {
3545         struct packet_mclist *ml;
3546 
3547         while ((ml = *mlp) != NULL) {
3548                 if (ml->ifindex == dev->ifindex) {
3549                         packet_dev_mc(dev, ml, -1);
3550                         *mlp = ml->next;
3551                         kfree(ml);
3552                 } else
3553                         mlp = &ml->next;
3554         }
3555 }
3556 
3557 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3558 {
3559         struct packet_sock *po = pkt_sk(sk);
3560         struct packet_mclist *ml, *i;
3561         struct net_device *dev;
3562         int err;
3563 
3564         rtnl_lock();
3565 
3566         err = -ENODEV;
3567         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3568         if (!dev)
3569                 goto done;
3570 
3571         err = -EINVAL;
3572         if (mreq->mr_alen > dev->addr_len)
3573                 goto done;
3574 
3575         err = -ENOBUFS;
3576         i = kmalloc(sizeof(*i), GFP_KERNEL);
3577         if (i == NULL)
3578                 goto done;
3579 
3580         err = 0;
3581         for (ml = po->mclist; ml; ml = ml->next) {
3582                 if (ml->ifindex == mreq->mr_ifindex &&
3583                     ml->type == mreq->mr_type &&
3584                     ml->alen == mreq->mr_alen &&
3585                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3586                         ml->count++;
3587                         /* Free the new element ... */
3588                         kfree(i);
3589                         goto done;
3590                 }
3591         }
3592 
3593         i->type = mreq->mr_type;
3594         i->ifindex = mreq->mr_ifindex;
3595         i->alen = mreq->mr_alen;
3596         memcpy(i->addr, mreq->mr_address, i->alen);
3597         memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3598         i->count = 1;
3599         i->next = po->mclist;
3600         po->mclist = i;
3601         err = packet_dev_mc(dev, i, 1);
3602         if (err) {
3603                 po->mclist = i->next;
3604                 kfree(i);
3605         }
3606 
3607 done:
3608         rtnl_unlock();
3609         return err;
3610 }
3611 
3612 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3613 {
3614         struct packet_mclist *ml, **mlp;
3615 
3616         rtnl_lock();
3617 
3618         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3619                 if (ml->ifindex == mreq->mr_ifindex &&
3620                     ml->type == mreq->mr_type &&
3621                     ml->alen == mreq->mr_alen &&
3622                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3623                         if (--ml->count == 0) {
3624                                 struct net_device *dev;
3625                                 *mlp = ml->next;
3626                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3627                                 if (dev)
3628                                         packet_dev_mc(dev, ml, -1);
3629                                 kfree(ml);
3630                         }
3631                         break;
3632                 }
3633         }
3634         rtnl_unlock();
3635         return 0;
3636 }
3637 
3638 static void packet_flush_mclist(struct sock *sk)
3639 {
3640         struct packet_sock *po = pkt_sk(sk);
3641         struct packet_mclist *ml;
3642 
3643         if (!po->mclist)
3644                 return;
3645 
3646         rtnl_lock();
3647         while ((ml = po->mclist) != NULL) {
3648                 struct net_device *dev;
3649 
3650                 po->mclist = ml->next;
3651                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3652                 if (dev != NULL)
3653                         packet_dev_mc(dev, ml, -1);
3654                 kfree(ml);
3655         }
3656         rtnl_unlock();
3657 }
3658 
3659 static int
3660 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3661 {
3662         struct sock *sk = sock->sk;
3663         struct packet_sock *po = pkt_sk(sk);
3664         int ret;
3665 
3666         if (level != SOL_PACKET)
3667                 return -ENOPROTOOPT;
3668 
3669         switch (optname) {
3670         case PACKET_ADD_MEMBERSHIP:
3671         case PACKET_DROP_MEMBERSHIP:
3672         {
3673                 struct packet_mreq_max mreq;
3674                 int len = optlen;
3675                 memset(&mreq, 0, sizeof(mreq));
3676                 if (len < sizeof(struct packet_mreq))
3677                         return -EINVAL;
3678                 if (len > sizeof(mreq))
3679                         len = sizeof(mreq);
3680                 if (copy_from_user(&mreq, optval, len))
3681                         return -EFAULT;
3682                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3683                         return -EINVAL;
3684                 if (optname == PACKET_ADD_MEMBERSHIP)
3685                         ret = packet_mc_add(sk, &mreq);
3686                 else
3687                         ret = packet_mc_drop(sk, &mreq);
3688                 return ret;
3689         }
3690 
3691         case PACKET_RX_RING:
3692         case PACKET_TX_RING:
3693         {
3694                 union tpacket_req_u req_u;
3695                 int len;
3696 
3697                 lock_sock(sk);
3698                 switch (po->tp_version) {
3699                 case TPACKET_V1:
3700                 case TPACKET_V2:
3701                         len = sizeof(req_u.req);
3702                         break;
3703                 case TPACKET_V3:
3704                 default:
3705                         len = sizeof(req_u.req3);
3706                         break;
3707                 }
3708                 if (optlen < len) {
3709                         ret = -EINVAL;
3710                 } else {
3711                         if (copy_from_user(&req_u.req, optval, len))
3712                                 ret = -EFAULT;
3713                         else
3714                                 ret = packet_set_ring(sk, &req_u, 0,
3715                                                     optname == PACKET_TX_RING);
3716                 }
3717                 release_sock(sk);
3718                 return ret;
3719         }
3720         case PACKET_COPY_THRESH:
3721         {
3722                 int val;
3723 
3724                 if (optlen != sizeof(val))
3725                         return -EINVAL;
3726                 if (copy_from_user(&val, optval, sizeof(val)))
3727                         return -EFAULT;
3728 
3729                 pkt_sk(sk)->copy_thresh = val;
3730                 return 0;
3731         }
3732         case PACKET_VERSION:
3733         {
3734                 int val;
3735 
3736                 if (optlen != sizeof(val))
3737                         return -EINVAL;
3738                 if (copy_from_user(&val, optval, sizeof(val)))
3739                         return -EFAULT;
3740                 switch (val) {
3741                 case TPACKET_V1:
3742                 case TPACKET_V2:
3743                 case TPACKET_V3:
3744                         break;
3745                 default:
3746                         return -EINVAL;
3747                 }
3748                 lock_sock(sk);
3749                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3750                         ret = -EBUSY;
3751                 } else {
3752                         po->tp_version = val;
3753                         ret = 0;
3754                 }
3755                 release_sock(sk);
3756                 return ret;
3757         }
3758         case PACKET_RESERVE:
3759         {
3760                 unsigned int val;
3761 
3762                 if (optlen != sizeof(val))
3763                         return -EINVAL;
3764                 if (copy_from_user(&val, optval, sizeof(val)))
3765                         return -EFAULT;
3766                 if (val > INT_MAX)
3767                         return -EINVAL;
3768                 lock_sock(sk);
3769                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3770                         ret = -EBUSY;
3771                 } else {
3772                         po->tp_reserve = val;
3773                         ret = 0;
3774                 }
3775                 release_sock(sk);
3776                 return ret;
3777         }
3778         case PACKET_LOSS:
3779         {
3780                 unsigned int val;
3781 
3782                 if (optlen != sizeof(val))
3783                         return -EINVAL;
3784                 if (copy_from_user(&val, optval, sizeof(val)))
3785                         return -EFAULT;
3786 
3787                 lock_sock(sk);
3788                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3789                         ret = -EBUSY;
3790                 } else {
3791                         po->tp_loss = !!val;
3792                         ret = 0;
3793                 }
3794                 release_sock(sk);
3795                 return ret;
3796         }
3797         case PACKET_AUXDATA:
3798         {
3799                 int val;
3800 
3801                 if (optlen < sizeof(val))
3802                         return -EINVAL;
3803                 if (copy_from_user(&val, optval, sizeof(val)))
3804                         return -EFAULT;
3805 
3806                 lock_sock(sk);
3807                 po->auxdata = !!val;
3808                 release_sock(sk);
3809                 return 0;
3810         }
3811         case PACKET_ORIGDEV:
3812         {
3813                 int val;
3814 
3815                 if (optlen < sizeof(val))
3816                         return -EINVAL;
3817                 if (copy_from_user(&val, optval, sizeof(val)))
3818                         return -EFAULT;
3819 
3820                 lock_sock(sk);
3821                 po->origdev = !!val;
3822                 release_sock(sk);
3823                 return 0;
3824         }
3825         case PACKET_VNET_HDR:
3826         {
3827                 int val;
3828 
3829                 if (sock->type != SOCK_RAW)
3830                         return -EINVAL;
3831                 if (optlen < sizeof(val))
3832                         return -EINVAL;
3833                 if (copy_from_user(&val, optval, sizeof(val)))
3834                         return -EFAULT;
3835 
3836                 lock_sock(sk);
3837                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3838                         ret = -EBUSY;
3839                 } else {
3840                         po->has_vnet_hdr = !!val;
3841                         ret = 0;
3842                 }
3843                 release_sock(sk);
3844                 return ret;
3845         }
3846         case PACKET_TIMESTAMP:
3847         {
3848                 int val;
3849 
3850                 if (optlen != sizeof(val))
3851                         return -EINVAL;
3852                 if (copy_from_user(&val, optval, sizeof(val)))
3853                         return -EFAULT;
3854 
3855                 po->tp_tstamp = val;
3856                 return 0;
3857         }
3858         case PACKET_FANOUT:
3859         {
3860                 int val;
3861 
3862                 if (optlen != sizeof(val))
3863                         return -EINVAL;
3864                 if (copy_from_user(&val, optval, sizeof(val)))
3865                         return -EFAULT;
3866 
3867                 return fanout_add(sk, val & 0xffff, val >> 16);
3868         }
3869         case PACKET_FANOUT_DATA:
3870         {
3871                 if (!po->fanout)
3872                         return -EINVAL;
3873 
3874                 return fanout_set_data(po, optval, optlen);
3875         }
3876         case PACKET_IGNORE_OUTGOING:
3877         {
3878                 int val;
3879 
3880                 if (optlen != sizeof(val))
3881                         return -EINVAL;
3882                 if (copy_from_user(&val, optval, sizeof(val)))
3883                         return -EFAULT;
3884                 if (val < 0 || val > 1)
3885                         return -EINVAL;
3886 
3887                 po->prot_hook.ignore_outgoing = !!val;
3888                 return 0;
3889         }
3890         case PACKET_TX_HAS_OFF:
3891         {
3892                 unsigned int val;
3893 
3894                 if (optlen != sizeof(val))
3895                         return -EINVAL;
3896                 if (copy_from_user(&val, optval, sizeof(val)))
3897                         return -EFAULT;
3898 
3899                 lock_sock(sk);
3900                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3901                         ret = -EBUSY;
3902                 } else {
3903                         po->tp_tx_has_off = !!val;
3904                         ret = 0;
3905                 }
3906                 release_sock(sk);
3907                 return 0;
3908         }
3909         case PACKET_QDISC_BYPASS:
3910         {
3911                 int val;
3912 
3913                 if (optlen != sizeof(val))
3914                         return -EINVAL;
3915                 if (copy_from_user(&val, optval, sizeof(val)))
3916                         return -EFAULT;
3917 
3918                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3919                 return 0;
3920         }
3921         default:
3922                 return -ENOPROTOOPT;
3923         }
3924 }
3925 
3926 static int packet_getsockopt(struct socket *sock, int level, int optname,
3927                              char __user *optval, int __user *optlen)
3928 {
3929         int len;
3930         int val, lv = sizeof(val);
3931         struct sock *sk = sock->sk;
3932         struct packet_sock *po = pkt_sk(sk);
3933         void *data = &val;
3934         union tpacket_stats_u st;
3935         struct tpacket_rollover_stats rstats;
3936         int drops;
3937 
3938         if (level != SOL_PACKET)
3939                 return -ENOPROTOOPT;
3940 
3941         if (get_user(len, optlen))
3942                 return -EFAULT;
3943 
3944         if (len < 0)
3945                 return -EINVAL;
3946 
3947         switch (optname) {
3948         case PACKET_STATISTICS:
3949                 spin_lock_bh(&sk->sk_receive_queue.lock);
3950                 memcpy(&st, &po->stats, sizeof(st));
3951                 memset(&po->stats, 0, sizeof(po->stats));
3952                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3953                 drops = atomic_xchg(&po->tp_drops, 0);
3954 
3955                 if (po->tp_version == TPACKET_V3) {
3956                         lv = sizeof(struct tpacket_stats_v3);
3957                         st.stats3.tp_drops = drops;
3958                         st.stats3.tp_packets += drops;
3959                         data = &st.stats3;
3960                 } else {
3961                         lv = sizeof(struct tpacket_stats);
3962                         st.stats1.tp_drops = drops;
3963                         st.stats1.tp_packets += drops;
3964                         data = &st.stats1;
3965                 }
3966 
3967                 break;
3968         case PACKET_AUXDATA:
3969                 val = po->auxdata;
3970                 break;
3971         case PACKET_ORIGDEV:
3972                 val = po->origdev;
3973                 break;
3974         case PACKET_VNET_HDR:
3975                 val = po->has_vnet_hdr;
3976                 break;
3977         case PACKET_VERSION:
3978                 val = po->tp_version;
3979                 break;
3980         case PACKET_HDRLEN:
3981                 if (len > sizeof(int))
3982                         len = sizeof(int);
3983                 if (len < sizeof(int))
3984                         return -EINVAL;
3985                 if (copy_from_user(&val, optval, len))
3986                         return -EFAULT;
3987                 switch (val) {
3988                 case TPACKET_V1:
3989                         val = sizeof(struct tpacket_hdr);
3990                         break;
3991                 case TPACKET_V2:
3992                         val = sizeof(struct tpacket2_hdr);
3993                         break;
3994                 case TPACKET_V3:
3995                         val = sizeof(struct tpacket3_hdr);
3996                         break;
3997                 default:
3998                         return -EINVAL;
3999                 }
4000                 break;
4001         case PACKET_RESERVE:
4002                 val = po->tp_reserve;
4003                 break;
4004         case PACKET_LOSS:
4005                 val = po->tp_loss;
4006                 break;
4007         case PACKET_TIMESTAMP:
4008                 val = po->tp_tstamp;
4009                 break;
4010         case PACKET_FANOUT:
4011                 val = (po->fanout ?
4012                        ((u32)po->fanout->id |
4013                         ((u32)po->fanout->type << 16) |
4014                         ((u32)po->fanout->flags << 24)) :
4015                        0);
4016                 break;
4017         case PACKET_IGNORE_OUTGOING:
4018                 val = po->prot_hook.ignore_outgoing;
4019                 break;
4020         case PACKET_ROLLOVER_STATS:
4021                 if (!po->rollover)
4022                         return -EINVAL;
4023                 rstats.tp_all = atomic_long_read(&po->rollover->num);
4024                 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
4025                 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
4026                 data = &rstats;
4027                 lv = sizeof(rstats);
4028                 break;
4029         case PACKET_TX_HAS_OFF:
4030                 val = po->tp_tx_has_off;
4031                 break;
4032         case PACKET_QDISC_BYPASS:
4033                 val = packet_use_direct_xmit(po);
4034                 break;
4035         default:
4036                 return -ENOPROTOOPT;
4037         }
4038 
4039         if (len > lv)
4040                 len = lv;
4041         if (put_user(len, optlen))
4042                 return -EFAULT;
4043         if (copy_to_user(optval, data, len))
4044                 return -EFAULT;
4045         return 0;
4046 }
4047 
4048 
4049 #ifdef CONFIG_COMPAT
4050 static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
4051                                     char __user *optval, unsigned int optlen)
4052 {
4053         struct packet_sock *po = pkt_sk(sock->sk);
4054 
4055         if (level != SOL_PACKET)
4056                 return -ENOPROTOOPT;
4057 
4058         if (optname == PACKET_FANOUT_DATA &&
4059             po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
4060                 optval = (char __user *)get_compat_bpf_fprog(optval);
4061                 if (!optval)
4062                         return -EFAULT;
4063                 optlen = sizeof(struct sock_fprog);
4064         }
4065 
4066         return packet_setsockopt(sock, level, optname, optval, optlen);
4067 }
4068 #endif
4069 
4070 static int packet_notifier(struct notifier_block *this,
4071                            unsigned long msg, void *ptr)
4072 {
4073         struct sock *sk;
4074         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4075         struct net *net = dev_net(dev);
4076 
4077         rcu_read_lock();
4078         sk_for_each_rcu(sk, &net->packet.sklist) {
4079                 struct packet_sock *po = pkt_sk(sk);
4080 
4081                 switch (msg) {
4082                 case NETDEV_UNREGISTER:
4083                         if (po->mclist)
4084                                 packet_dev_mclist_delete(dev, &po->mclist);
4085                         /* fallthrough */
4086 
4087                 case NETDEV_DOWN:
4088                         if (dev->ifindex == po->ifindex) {
4089                                 spin_lock(&po->bind_lock);
4090                                 if (po->running) {
4091                                         __unregister_prot_hook(sk, false);
4092                                         sk->sk_err = ENETDOWN;
4093                                         if (!sock_flag(sk, SOCK_DEAD))
4094                                                 sk->sk_error_report(sk);
4095                                 }
4096                                 if (msg == NETDEV_UNREGISTER) {
4097                                         packet_cached_dev_reset(po);
4098                                         po->ifindex = -1;
4099                                         if (po->prot_hook.dev)
4100                                                 dev_put(po->prot_hook.dev);
4101                                         po->prot_hook.dev = NULL;
4102                                 }
4103                                 spin_unlock(&po->bind_lock);
4104                         }
4105                         break;
4106                 case NETDEV_UP:
4107                         if (dev->ifindex == po->ifindex) {
4108                                 spin_lock(&po->bind_lock);
4109                                 if (po->num)
4110                                         register_prot_hook(sk);
4111                                 spin_unlock(&po->bind_lock);
4112                         }
4113                         break;
4114                 }
4115         }
4116         rcu_read_unlock();
4117         return NOTIFY_DONE;
4118 }
4119 
4120 
4121 static int packet_ioctl(struct socket *sock, unsigned int cmd,
4122                         unsigned long arg)
4123 {
4124         struct sock *sk = sock->sk;
4125 
4126         switch (cmd) {
4127         case SIOCOUTQ:
4128         {
4129                 int amount = sk_wmem_alloc_get(sk);
4130 
4131                 return put_user(amount, (int __user *)arg);
4132         }
4133         case SIOCINQ:
4134         {
4135                 struct sk_buff *skb;
4136                 int amount = 0;
4137 
4138                 spin_lock_bh(&sk->sk_receive_queue.lock);
4139                 skb = skb_peek(&sk->sk_receive_queue);
4140                 if (skb)
4141                         amount = skb->len;
4142                 spin_unlock_bh(&sk->sk_receive_queue.lock);
4143                 return put_user(amount, (int __user *)arg);
4144         }
4145 #ifdef CONFIG_INET
4146         case SIOCADDRT:
4147         case SIOCDELRT:
4148         case SIOCDARP:
4149         case SIOCGARP:
4150         case SIOCSARP:
4151         case SIOCGIFADDR:
4152         case SIOCSIFADDR:
4153         case SIOCGIFBRDADDR:
4154         case SIOCSIFBRDADDR:
4155         case SIOCGIFNETMASK:
4156         case SIOCSIFNETMASK:
4157         case SIOCGIFDSTADDR:
4158         case SIOCSIFDSTADDR:
4159         case SIOCSIFFLAGS:
4160                 return inet_dgram_ops.ioctl(sock, cmd, arg);
4161 #endif
4162 
4163         default:
4164                 return -ENOIOCTLCMD;
4165         }
4166         return 0;
4167 }
4168 
4169 static __poll_t packet_poll(struct file *file, struct socket *sock,
4170                                 poll_table *wait)
4171 {
4172         struct sock *sk = sock->sk;
4173         struct packet_sock *po = pkt_sk(sk);
4174         __poll_t mask = datagram_poll(file, sock, wait);
4175 
4176         spin_lock_bh(&sk->sk_receive_queue.lock);
4177         if (po->rx_ring.pg_vec) {
4178                 if (!packet_previous_rx_frame(po, &po->rx_ring,
4179                         TP_STATUS_KERNEL))
4180                         mask |= EPOLLIN | EPOLLRDNORM;
4181         }
4182         packet_rcv_try_clear_pressure(po);
4183         spin_unlock_bh(&sk->sk_receive_queue.lock);
4184         spin_lock_bh(&sk->sk_write_queue.lock);
4185         if (po->tx_ring.pg_vec) {
4186                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4187                         mask |= EPOLLOUT | EPOLLWRNORM;
4188         }
4189         spin_unlock_bh(&sk->sk_write_queue.lock);
4190         return mask;
4191 }
4192 
4193 
4194 /* Dirty? Well, I still did not learn better way to account
4195  * for user mmaps.
4196  */
4197 
4198 static void packet_mm_open(struct vm_area_struct *vma)
4199 {
4200         struct file *file = vma->vm_file;
4201         struct socket *sock = file->private_data;
4202         struct sock *sk = sock->sk;
4203 
4204         if (sk)
4205                 atomic_inc(&pkt_sk(sk)->mapped);
4206 }
4207 
4208 static void packet_mm_close(struct vm_area_struct *vma)
4209 {
4210         struct file *file = vma->vm_file;
4211         struct socket *sock = file->private_data;
4212         struct sock *sk = sock->sk;
4213 
4214         if (sk)
4215                 atomic_dec(&pkt_sk(sk)->mapped);
4216 }
4217 
4218 static const struct vm_operations_struct packet_mmap_ops = {
4219         .open   =       packet_mm_open,
4220         .close  =       packet_mm_close,
4221 };
4222 
4223 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4224                         unsigned int len)
4225 {
4226         int i;
4227 
4228         for (i = 0; i < len; i++) {
4229                 if (likely(pg_vec[i].buffer)) {
4230                         if (is_vmalloc_addr(pg_vec[i].buffer))
4231                                 vfree(pg_vec[i].buffer);
4232                         else
4233                                 free_pages((unsigned long)pg_vec[i].buffer,
4234                                            order);
4235                         pg_vec[i].buffer = NULL;
4236                 }
4237         }
4238         kfree(pg_vec);
4239 }
4240 
4241 static char *alloc_one_pg_vec_page(unsigned long order)
4242 {
4243         char *buffer;
4244         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4245                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4246 
4247         buffer = (char *) __get_free_pages(gfp_flags, order);
4248         if (buffer)
4249                 return buffer;
4250 
4251         /* __get_free_pages failed, fall back to vmalloc */
4252         buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
4253         if (buffer)
4254                 return buffer;
4255 
4256         /* vmalloc failed, lets dig into swap here */
4257         gfp_flags &= ~__GFP_NORETRY;
4258         buffer = (char *) __get_free_pages(gfp_flags, order);
4259         if (buffer)
4260                 return buffer;
4261 
4262         /* complete and utter failure */
4263         return NULL;
4264 }
4265 
4266 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4267 {
4268         unsigned int block_nr = req->tp_block_nr;
4269         struct pgv *pg_vec;
4270         int i;
4271 
4272         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
4273         if (unlikely(!pg_vec))
4274                 goto out;
4275 
4276         for (i = 0; i < block_nr; i++) {
4277                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4278                 if (unlikely(!pg_vec[i].buffer))
4279                         goto out_free_pgvec;
4280         }
4281 
4282 out:
4283         return pg_vec;
4284 
4285 out_free_pgvec:
4286         free_pg_vec(pg_vec, order, block_nr);
4287         pg_vec = NULL;
4288         goto out;
4289 }
4290 
4291 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4292                 int closing, int tx_ring)
4293 {
4294         struct pgv *pg_vec = NULL;
4295         struct packet_sock *po = pkt_sk(sk);
4296         unsigned long *rx_owner_map = NULL;
4297         int was_running, order = 0;
4298         struct packet_ring_buffer *rb;
4299         struct sk_buff_head *rb_queue;
4300         __be16 num;
4301         int err = -EINVAL;
4302         /* Added to avoid minimal code churn */
4303         struct tpacket_req *req = &req_u->req;
4304 
4305         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4306         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4307 
4308         err = -EBUSY;
4309         if (!closing) {
4310                 if (atomic_read(&po->mapped))
4311                         goto out;
4312                 if (packet_read_pending(rb))
4313                         goto out;
4314         }
4315 
4316         if (req->tp_block_nr) {
4317                 unsigned int min_frame_size;
4318 
4319                 /* Sanity tests and some calculations */
4320                 err = -EBUSY;
4321                 if (unlikely(rb->pg_vec))
4322                         goto out;
4323 
4324                 switch (po->tp_version) {
4325                 case TPACKET_V1:
4326                         po->tp_hdrlen = TPACKET_HDRLEN;
4327                         break;
4328                 case TPACKET_V2:
4329                         po->tp_hdrlen = TPACKET2_HDRLEN;
4330                         break;
4331                 case TPACKET_V3:
4332                         po->tp_hdrlen = TPACKET3_HDRLEN;
4333                         break;
4334                 }
4335 
4336                 err = -EINVAL;
4337                 if (unlikely((int)req->tp_block_size <= 0))
4338                         goto out;
4339                 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4340                         goto out;
4341                 min_frame_size = po->tp_hdrlen + po->tp_reserve;
4342                 if (po->tp_version >= TPACKET_V3 &&
4343                     req->tp_block_size <
4344                     BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size)
4345                         goto out;
4346                 if (unlikely(req->tp_frame_size < min_frame_size))
4347                         goto out;
4348                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4349                         goto out;
4350 
4351                 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4352                 if (unlikely(rb->frames_per_block == 0))
4353                         goto out;
4354                 if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr))
4355                         goto out;
4356                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4357                                         req->tp_frame_nr))
4358                         goto out;
4359 
4360                 err = -ENOMEM;
4361                 order = get_order(req->tp_block_size);
4362                 pg_vec = alloc_pg_vec(req, order);
4363                 if (unlikely(!pg_vec))
4364                         goto out;
4365                 switch (po->tp_version) {
4366                 case TPACKET_V3:
4367                         /* Block transmit is not supported yet */
4368                         if (!tx_ring) {
4369                                 init_prb_bdqc(po, rb, pg_vec, req_u);
4370                         } else {
4371                                 struct tpacket_req3 *req3 = &req_u->req3;
4372 
4373                                 if (req3->tp_retire_blk_tov ||
4374                                     req3->tp_sizeof_priv ||
4375                                     req3->tp_feature_req_word) {
4376                                         err = -EINVAL;
4377                                         goto out_free_pg_vec;
4378                                 }
4379                         }
4380                         break;
4381                 default:
4382                         if (!tx_ring) {
4383                                 rx_owner_map = bitmap_alloc(req->tp_frame_nr,
4384                                         GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
4385                                 if (!rx_owner_map)
4386                                         goto out_free_pg_vec;
4387                         }
4388                         break;
4389                 }
4390         }
4391         /* Done */
4392         else {
4393                 err = -EINVAL;
4394                 if (unlikely(req->tp_frame_nr))
4395                         goto out;
4396         }
4397 
4398 
4399         /* Detach socket from network */
4400         spin_lock(&po->bind_lock);
4401         was_running = po->running;
4402         num = po->num;
4403         if (was_running) {
4404                 po->num = 0;
4405                 __unregister_prot_hook(sk, false);
4406         }
4407         spin_unlock(&po->bind_lock);
4408 
4409         synchronize_net();
4410 
4411         err = -EBUSY;
4412         mutex_lock(&po->pg_vec_lock);
4413         if (closing || atomic_read(&po->mapped) == 0) {
4414                 err = 0;
4415                 spin_lock_bh(&rb_queue->lock);
4416                 swap(rb->pg_vec, pg_vec);
4417                 if (po->tp_version <= TPACKET_V2)
4418                         swap(rb->rx_owner_map, rx_owner_map);
4419                 rb->frame_max = (req->tp_frame_nr - 1);
4420                 rb->head = 0;
4421                 rb->frame_size = req->tp_frame_size;
4422                 spin_unlock_bh(&rb_queue->lock);
4423 
4424                 swap(rb->pg_vec_order, order);
4425                 swap(rb->pg_vec_len, req->tp_block_nr);
4426 
4427                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4428                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4429                                                 tpacket_rcv : packet_rcv;
4430                 skb_queue_purge(rb_queue);
4431                 if (atomic_read(&po->mapped))
4432                         pr_err("packet_mmap: vma is busy: %d\n",
4433                                atomic_read(&po->mapped));
4434         }
4435         mutex_unlock(&po->pg_vec_lock);
4436 
4437         spin_lock(&po->bind_lock);
4438         if (was_running) {
4439                 po->num = num;
4440                 register_prot_hook(sk);
4441         }
4442         spin_unlock(&po->bind_lock);
4443         if (pg_vec && (po->tp_version > TPACKET_V2)) {
4444                 /* Because we don't support block-based V3 on tx-ring */
4445                 if (!tx_ring)
4446                         prb_shutdown_retire_blk_timer(po, rb_queue);
4447         }
4448 
4449 out_free_pg_vec:
4450         bitmap_free(rx_owner_map);
4451         if (pg_vec)
4452                 free_pg_vec(pg_vec, order, req->tp_block_nr);
4453 out:
4454         return err;
4455 }
4456 
4457 static int packet_mmap(struct file *file, struct socket *sock,
4458                 struct vm_area_struct *vma)
4459 {
4460         struct sock *sk = sock->sk;
4461         struct packet_sock *po = pkt_sk(sk);
4462         unsigned long size, expected_size;
4463         struct packet_ring_buffer *rb;
4464         unsigned long start;
4465         int err = -EINVAL;
4466         int i;
4467 
4468         if (vma->vm_pgoff)
4469                 return -EINVAL;
4470 
4471         mutex_lock(&po->pg_vec_lock);
4472 
4473         expected_size = 0;
4474         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4475                 if (rb->pg_vec) {
4476                         expected_size += rb->pg_vec_len
4477                                                 * rb->pg_vec_pages
4478                                                 * PAGE_SIZE;
4479                 }
4480         }
4481 
4482         if (expected_size == 0)
4483                 goto out;
4484 
4485         size = vma->vm_end - vma->vm_start;
4486         if (size != expected_size)
4487                 goto out;
4488 
4489         start = vma->vm_start;
4490         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4491                 if (rb->pg_vec == NULL)
4492                         continue;
4493 
4494                 for (i = 0; i < rb->pg_vec_len; i++) {
4495                         struct page *page;
4496                         void *kaddr = rb->pg_vec[i].buffer;
4497                         int pg_num;
4498 
4499                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4500                                 page = pgv_to_page(kaddr);
4501                                 err = vm_insert_page(vma, start, page);
4502                                 if (unlikely(err))
4503                                         goto out;
4504                                 start += PAGE_SIZE;
4505                                 kaddr += PAGE_SIZE;
4506                         }
4507                 }
4508         }
4509 
4510         atomic_inc(&po->mapped);
4511         vma->vm_ops = &packet_mmap_ops;
4512         err = 0;
4513 
4514 out:
4515         mutex_unlock(&po->pg_vec_lock);
4516         return err;
4517 }
4518 
4519 static const struct proto_ops packet_ops_spkt = {
4520         .family =       PF_PACKET,
4521         .owner =        THIS_MODULE,
4522         .release =      packet_release,
4523         .bind =         packet_bind_spkt,
4524         .connect =      sock_no_connect,
4525         .socketpair =   sock_no_socketpair,
4526         .accept =       sock_no_accept,
4527         .getname =      packet_getname_spkt,
4528         .poll =         datagram_poll,
4529         .ioctl =        packet_ioctl,
4530         .gettstamp =    sock_gettstamp,
4531         .listen =       sock_no_listen,
4532         .shutdown =     sock_no_shutdown,
4533         .setsockopt =   sock_no_setsockopt,
4534         .getsockopt =   sock_no_getsockopt,
4535         .sendmsg =      packet_sendmsg_spkt,
4536         .recvmsg =      packet_recvmsg,
4537         .mmap =         sock_no_mmap,
4538         .sendpage =     sock_no_sendpage,
4539 };
4540 
4541 static const struct proto_ops packet_ops = {
4542         .family =       PF_PACKET,
4543         .owner =        THIS_MODULE,
4544         .release =      packet_release,
4545         .bind =         packet_bind,
4546         .connect =      sock_no_connect,
4547         .socketpair =   sock_no_socketpair,
4548         .accept =       sock_no_accept,
4549         .getname =      packet_getname,
4550         .poll =         packet_poll,
4551         .ioctl =        packet_ioctl,
4552         .gettstamp =    sock_gettstamp,
4553         .listen =       sock_no_listen,
4554         .shutdown =     sock_no_shutdown,
4555         .setsockopt =   packet_setsockopt,
4556         .getsockopt =   packet_getsockopt,
4557 #ifdef CONFIG_COMPAT
4558         .compat_setsockopt = compat_packet_setsockopt,
4559 #endif
4560         .sendmsg =      packet_sendmsg,
4561         .recvmsg =      packet_recvmsg,
4562         .mmap =         packet_mmap,
4563         .sendpage =     sock_no_sendpage,
4564 };
4565 
4566 static const struct net_proto_family packet_family_ops = {
4567         .family =       PF_PACKET,
4568         .create =       packet_create,
4569         .owner  =       THIS_MODULE,
4570 };
4571 
4572 static struct notifier_block packet_netdev_notifier = {
4573         .notifier_call =        packet_notifier,
4574 };
4575 
4576 #ifdef CONFIG_PROC_FS
4577 
4578 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4579         __acquires(RCU)
4580 {
4581         struct net *net = seq_file_net(seq);
4582 
4583         rcu_read_lock();
4584         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4585 }
4586 
4587 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4588 {
4589         struct net *net = seq_file_net(seq);
4590         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4591 }
4592 
4593 static void packet_seq_stop(struct seq_file *seq, void *v)
4594         __releases(RCU)
4595 {
4596         rcu_read_unlock();
4597 }
4598 
4599 static int packet_seq_show(struct seq_file *seq, void *v)
4600 {
4601         if (v == SEQ_START_TOKEN)
4602                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4603         else {
4604                 struct sock *s = sk_entry(v);
4605                 const struct packet_sock *po = pkt_sk(s);
4606 
4607                 seq_printf(seq,
4608                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4609                            s,
4610                            refcount_read(&s->sk_refcnt),
4611                            s->sk_type,
4612                            ntohs(po->num),
4613                            po->ifindex,
4614                            po->running,
4615                            atomic_read(&s->sk_rmem_alloc),
4616                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4617                            sock_i_ino(s));
4618         }
4619 
4620         return 0;
4621 }
4622 
4623 static const struct seq_operations packet_seq_ops = {
4624         .start  = packet_seq_start,
4625         .next   = packet_seq_next,
4626         .stop   = packet_seq_stop,
4627         .show   = packet_seq_show,
4628 };
4629 #endif
4630 
4631 static int __net_init packet_net_init(struct net *net)
4632 {
4633         mutex_init(&net->packet.sklist_lock);
4634         INIT_HLIST_HEAD(&net->packet.sklist);
4635 
4636         if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops,
4637                         sizeof(struct seq_net_private)))
4638                 return -ENOMEM;
4639 
4640         return 0;
4641 }
4642 
4643 static void __net_exit packet_net_exit(struct net *net)
4644 {
4645         remove_proc_entry("packet", net->proc_net);
4646         WARN_ON_ONCE(!hlist_empty(&net->packet.sklist));
4647 }
4648 
4649 static struct pernet_operations packet_net_ops = {
4650         .init = packet_net_init,
4651         .exit = packet_net_exit,
4652 };
4653 
4654 
4655 static void __exit packet_exit(void)
4656 {
4657         unregister_netdevice_notifier(&packet_netdev_notifier);
4658         unregister_pernet_subsys(&packet_net_ops);
4659         sock_unregister(PF_PACKET);
4660         proto_unregister(&packet_proto);
4661 }
4662 
4663 static int __init packet_init(void)
4664 {
4665         int rc;
4666 
4667         rc = proto_register(&packet_proto, 0);
4668         if (rc)
4669                 goto out;
4670         rc = sock_register(&packet_family_ops);
4671         if (rc)
4672                 goto out_proto;
4673         rc = register_pernet_subsys(&packet_net_ops);
4674         if (rc)
4675                 goto out_sock;
4676         rc = register_netdevice_notifier(&packet_netdev_notifier);
4677         if (rc)
4678                 goto out_pernet;
4679 
4680         return 0;
4681 
4682 out_pernet:
4683         unregister_pernet_subsys(&packet_net_ops);
4684 out_sock:
4685         sock_unregister(PF_PACKET);
4686 out_proto:
4687         proto_unregister(&packet_proto);
4688 out:
4689         return rc;
4690 }
4691 
4692 module_init(packet_init);
4693 module_exit(packet_exit);
4694 MODULE_LICENSE("GPL");
4695 MODULE_ALIAS_NETPROTO(PF_PACKET);
4696 

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