Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[cascardo/linux.git] / net / packet / af_packet.c
1 /*
2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
3  *              operating system.  INET is implemented using the  BSD Socket
4  *              interface as the means of communication with the user level.
5  *
6  *              PACKET - implements raw packet sockets.
7  *
8  * Authors:     Ross Biro
9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
11  *
12  * Fixes:
13  *              Alan Cox        :       verify_area() now used correctly
14  *              Alan Cox        :       new skbuff lists, look ma no backlogs!
15  *              Alan Cox        :       tidied skbuff lists.
16  *              Alan Cox        :       Now uses generic datagram routines I
17  *                                      added. Also fixed the peek/read crash
18  *                                      from all old Linux datagram code.
19  *              Alan Cox        :       Uses the improved datagram code.
20  *              Alan Cox        :       Added NULL's for socket options.
21  *              Alan Cox        :       Re-commented the code.
22  *              Alan Cox        :       Use new kernel side addressing
23  *              Rob Janssen     :       Correct MTU usage.
24  *              Dave Platt      :       Counter leaks caused by incorrect
25  *                                      interrupt locking and some slightly
26  *                                      dubious gcc output. Can you read
27  *                                      compiler: it said _VOLATILE_
28  *      Richard Kooijman        :       Timestamp fixes.
29  *              Alan Cox        :       New buffers. Use sk->mac.raw.
30  *              Alan Cox        :       sendmsg/recvmsg support.
31  *              Alan Cox        :       Protocol setting support
32  *      Alexey Kuznetsov        :       Untied from IPv4 stack.
33  *      Cyrus Durgin            :       Fixed kerneld for kmod.
34  *      Michal Ostrowski        :       Module initialization cleanup.
35  *         Ulises Alonso        :       Frame number limit removal and
36  *                                      packet_set_ring memory leak.
37  *              Eric Biederman  :       Allow for > 8 byte hardware addresses.
38  *                                      The convention is that longer addresses
39  *                                      will simply extend the hardware address
40  *                                      byte arrays at the end of sockaddr_ll
41  *                                      and packet_mreq.
42  *              Johann Baudy    :       Added TX RING.
43  *              Chetan Loke     :       Implemented TPACKET_V3 block abstraction
44  *                                      layer.
45  *                                      Copyright (C) 2011, <lokec@ccs.neu.edu>
46  *
47  *
48  *              This program is free software; you can redistribute it and/or
49  *              modify it under the terms of the GNU General Public License
50  *              as published by the Free Software Foundation; either version
51  *              2 of the License, or (at your option) any later version.
52  *
53  */
54
55 #include <linux/types.h>
56 #include <linux/mm.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
60 #include <linux/in.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
70 #include <net/ip.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
73 #include <net/sock.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <asm/uaccess.h>
77 #include <asm/ioctls.h>
78 #include <asm/page.h>
79 #include <asm/cacheflush.h>
80 #include <asm/io.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91 #include <linux/percpu.h>
92 #ifdef CONFIG_INET
93 #include <net/inet_common.h>
94 #endif
95
96 #include "internal.h"
97
98 /*
99    Assumptions:
100    - if device has no dev->hard_header routine, it adds and removes ll header
101      inside itself. In this case ll header is invisible outside of device,
102      but higher levels still should reserve dev->hard_header_len.
103      Some devices are enough clever to reallocate skb, when header
104      will not fit to reserved space (tunnel), another ones are silly
105      (PPP).
106    - packet socket receives packets with pulled ll header,
107      so that SOCK_RAW should push it back.
108
109 On receive:
110 -----------
111
112 Incoming, dev->hard_header!=NULL
113    mac_header -> ll header
114    data       -> data
115
116 Outgoing, dev->hard_header!=NULL
117    mac_header -> ll header
118    data       -> ll header
119
120 Incoming, dev->hard_header==NULL
121    mac_header -> UNKNOWN position. It is very likely, that it points to ll
122                  header.  PPP makes it, that is wrong, because introduce
123                  assymetry between rx and tx paths.
124    data       -> data
125
126 Outgoing, dev->hard_header==NULL
127    mac_header -> data. ll header is still not built!
128    data       -> data
129
130 Resume
131   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
132
133
134 On transmit:
135 ------------
136
137 dev->hard_header != NULL
138    mac_header -> ll header
139    data       -> ll header
140
141 dev->hard_header == NULL (ll header is added by device, we cannot control it)
142    mac_header -> data
143    data       -> data
144
145    We should set nh.raw on output to correct posistion,
146    packet classifier depends on it.
147  */
148
149 /* Private packet socket structures. */
150
151 /* identical to struct packet_mreq except it has
152  * a longer address field.
153  */
154 struct packet_mreq_max {
155         int             mr_ifindex;
156         unsigned short  mr_type;
157         unsigned short  mr_alen;
158         unsigned char   mr_address[MAX_ADDR_LEN];
159 };
160
161 union tpacket_uhdr {
162         struct tpacket_hdr  *h1;
163         struct tpacket2_hdr *h2;
164         struct tpacket3_hdr *h3;
165         void *raw;
166 };
167
168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
169                 int closing, int tx_ring);
170
171 #define V3_ALIGNMENT    (8)
172
173 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
174
175 #define BLK_PLUS_PRIV(sz_of_priv) \
176         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
177
178 #define PGV_FROM_VMALLOC 1
179
180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
181 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
182 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
183 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
184 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
186 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
187
188 struct packet_sock;
189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
191                        struct packet_type *pt, struct net_device *orig_dev);
192
193 static void *packet_previous_frame(struct packet_sock *po,
194                 struct packet_ring_buffer *rb,
195                 int status);
196 static void packet_increment_head(struct packet_ring_buffer *buff);
197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
198                         struct tpacket_block_desc *);
199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200                         struct packet_sock *);
201 static void prb_retire_current_block(struct tpacket_kbdq_core *,
202                 struct packet_sock *, unsigned int status);
203 static int prb_queue_frozen(struct tpacket_kbdq_core *);
204 static void prb_open_block(struct tpacket_kbdq_core *,
205                 struct tpacket_block_desc *);
206 static void prb_retire_rx_blk_timer_expired(unsigned long);
207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208 static void prb_init_blk_timer(struct packet_sock *,
209                 struct tpacket_kbdq_core *,
210                 void (*func) (unsigned long));
211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
212 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
213                 struct tpacket3_hdr *);
214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
215                 struct tpacket3_hdr *);
216 static void packet_flush_mclist(struct sock *sk);
217
218 struct packet_skb_cb {
219         unsigned int origlen;
220         union {
221                 struct sockaddr_pkt pkt;
222                 struct sockaddr_ll ll;
223         } sa;
224 };
225
226 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
227
228 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
229 #define GET_PBLOCK_DESC(x, bid) \
230         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
232         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
233 #define GET_NEXT_PRB_BLK_NUM(x) \
234         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
235         ((x)->kactive_blk_num+1) : 0)
236
237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
238 static void __fanout_link(struct sock *sk, struct packet_sock *po);
239
240 static int packet_direct_xmit(struct sk_buff *skb)
241 {
242         struct net_device *dev = skb->dev;
243         netdev_features_t features;
244         struct netdev_queue *txq;
245         int ret = NETDEV_TX_BUSY;
246
247         if (unlikely(!netif_running(dev) ||
248                      !netif_carrier_ok(dev)))
249                 goto drop;
250
251         features = netif_skb_features(skb);
252         if (skb_needs_linearize(skb, features) &&
253             __skb_linearize(skb))
254                 goto drop;
255
256         txq = skb_get_tx_queue(dev, skb);
257
258         local_bh_disable();
259
260         HARD_TX_LOCK(dev, txq, smp_processor_id());
261         if (!netif_xmit_frozen_or_drv_stopped(txq))
262                 ret = netdev_start_xmit(skb, dev, txq, false);
263         HARD_TX_UNLOCK(dev, txq);
264
265         local_bh_enable();
266
267         if (!dev_xmit_complete(ret))
268                 kfree_skb(skb);
269
270         return ret;
271 drop:
272         atomic_long_inc(&dev->tx_dropped);
273         kfree_skb(skb);
274         return NET_XMIT_DROP;
275 }
276
277 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
278 {
279         struct net_device *dev;
280
281         rcu_read_lock();
282         dev = rcu_dereference(po->cached_dev);
283         if (likely(dev))
284                 dev_hold(dev);
285         rcu_read_unlock();
286
287         return dev;
288 }
289
290 static void packet_cached_dev_assign(struct packet_sock *po,
291                                      struct net_device *dev)
292 {
293         rcu_assign_pointer(po->cached_dev, dev);
294 }
295
296 static void packet_cached_dev_reset(struct packet_sock *po)
297 {
298         RCU_INIT_POINTER(po->cached_dev, NULL);
299 }
300
301 static bool packet_use_direct_xmit(const struct packet_sock *po)
302 {
303         return po->xmit == packet_direct_xmit;
304 }
305
306 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
307 {
308         return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
309 }
310
311 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
312 {
313         const struct net_device_ops *ops = dev->netdev_ops;
314         u16 queue_index;
315
316         if (ops->ndo_select_queue) {
317                 queue_index = ops->ndo_select_queue(dev, skb, NULL,
318                                                     __packet_pick_tx_queue);
319                 queue_index = netdev_cap_txqueue(dev, queue_index);
320         } else {
321                 queue_index = __packet_pick_tx_queue(dev, skb);
322         }
323
324         skb_set_queue_mapping(skb, queue_index);
325 }
326
327 /* register_prot_hook must be invoked with the po->bind_lock held,
328  * or from a context in which asynchronous accesses to the packet
329  * socket is not possible (packet_create()).
330  */
331 static void register_prot_hook(struct sock *sk)
332 {
333         struct packet_sock *po = pkt_sk(sk);
334
335         if (!po->running) {
336                 if (po->fanout)
337                         __fanout_link(sk, po);
338                 else
339                         dev_add_pack(&po->prot_hook);
340
341                 sock_hold(sk);
342                 po->running = 1;
343         }
344 }
345
346 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
347  * held.   If the sync parameter is true, we will temporarily drop
348  * the po->bind_lock and do a synchronize_net to make sure no
349  * asynchronous packet processing paths still refer to the elements
350  * of po->prot_hook.  If the sync parameter is false, it is the
351  * callers responsibility to take care of this.
352  */
353 static void __unregister_prot_hook(struct sock *sk, bool sync)
354 {
355         struct packet_sock *po = pkt_sk(sk);
356
357         po->running = 0;
358
359         if (po->fanout)
360                 __fanout_unlink(sk, po);
361         else
362                 __dev_remove_pack(&po->prot_hook);
363
364         __sock_put(sk);
365
366         if (sync) {
367                 spin_unlock(&po->bind_lock);
368                 synchronize_net();
369                 spin_lock(&po->bind_lock);
370         }
371 }
372
373 static void unregister_prot_hook(struct sock *sk, bool sync)
374 {
375         struct packet_sock *po = pkt_sk(sk);
376
377         if (po->running)
378                 __unregister_prot_hook(sk, sync);
379 }
380
381 static inline struct page * __pure pgv_to_page(void *addr)
382 {
383         if (is_vmalloc_addr(addr))
384                 return vmalloc_to_page(addr);
385         return virt_to_page(addr);
386 }
387
388 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
389 {
390         union tpacket_uhdr h;
391
392         h.raw = frame;
393         switch (po->tp_version) {
394         case TPACKET_V1:
395                 h.h1->tp_status = status;
396                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
397                 break;
398         case TPACKET_V2:
399                 h.h2->tp_status = status;
400                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
401                 break;
402         case TPACKET_V3:
403         default:
404                 WARN(1, "TPACKET version not supported.\n");
405                 BUG();
406         }
407
408         smp_wmb();
409 }
410
411 static int __packet_get_status(struct packet_sock *po, void *frame)
412 {
413         union tpacket_uhdr h;
414
415         smp_rmb();
416
417         h.raw = frame;
418         switch (po->tp_version) {
419         case TPACKET_V1:
420                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
421                 return h.h1->tp_status;
422         case TPACKET_V2:
423                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
424                 return h.h2->tp_status;
425         case TPACKET_V3:
426         default:
427                 WARN(1, "TPACKET version not supported.\n");
428                 BUG();
429                 return 0;
430         }
431 }
432
433 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
434                                    unsigned int flags)
435 {
436         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
437
438         if (shhwtstamps &&
439             (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
440             ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
441                 return TP_STATUS_TS_RAW_HARDWARE;
442
443         if (ktime_to_timespec_cond(skb->tstamp, ts))
444                 return TP_STATUS_TS_SOFTWARE;
445
446         return 0;
447 }
448
449 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
450                                     struct sk_buff *skb)
451 {
452         union tpacket_uhdr h;
453         struct timespec ts;
454         __u32 ts_status;
455
456         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
457                 return 0;
458
459         h.raw = frame;
460         switch (po->tp_version) {
461         case TPACKET_V1:
462                 h.h1->tp_sec = ts.tv_sec;
463                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
464                 break;
465         case TPACKET_V2:
466                 h.h2->tp_sec = ts.tv_sec;
467                 h.h2->tp_nsec = ts.tv_nsec;
468                 break;
469         case TPACKET_V3:
470         default:
471                 WARN(1, "TPACKET version not supported.\n");
472                 BUG();
473         }
474
475         /* one flush is safe, as both fields always lie on the same cacheline */
476         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
477         smp_wmb();
478
479         return ts_status;
480 }
481
482 static void *packet_lookup_frame(struct packet_sock *po,
483                 struct packet_ring_buffer *rb,
484                 unsigned int position,
485                 int status)
486 {
487         unsigned int pg_vec_pos, frame_offset;
488         union tpacket_uhdr h;
489
490         pg_vec_pos = position / rb->frames_per_block;
491         frame_offset = position % rb->frames_per_block;
492
493         h.raw = rb->pg_vec[pg_vec_pos].buffer +
494                 (frame_offset * rb->frame_size);
495
496         if (status != __packet_get_status(po, h.raw))
497                 return NULL;
498
499         return h.raw;
500 }
501
502 static void *packet_current_frame(struct packet_sock *po,
503                 struct packet_ring_buffer *rb,
504                 int status)
505 {
506         return packet_lookup_frame(po, rb, rb->head, status);
507 }
508
509 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
510 {
511         del_timer_sync(&pkc->retire_blk_timer);
512 }
513
514 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
515                 int tx_ring,
516                 struct sk_buff_head *rb_queue)
517 {
518         struct tpacket_kbdq_core *pkc;
519
520         pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) :
521                         GET_PBDQC_FROM_RB(&po->rx_ring);
522
523         spin_lock_bh(&rb_queue->lock);
524         pkc->delete_blk_timer = 1;
525         spin_unlock_bh(&rb_queue->lock);
526
527         prb_del_retire_blk_timer(pkc);
528 }
529
530 static void prb_init_blk_timer(struct packet_sock *po,
531                 struct tpacket_kbdq_core *pkc,
532                 void (*func) (unsigned long))
533 {
534         init_timer(&pkc->retire_blk_timer);
535         pkc->retire_blk_timer.data = (long)po;
536         pkc->retire_blk_timer.function = func;
537         pkc->retire_blk_timer.expires = jiffies;
538 }
539
540 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
541 {
542         struct tpacket_kbdq_core *pkc;
543
544         if (tx_ring)
545                 BUG();
546
547         pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) :
548                         GET_PBDQC_FROM_RB(&po->rx_ring);
549         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
550 }
551
552 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
553                                 int blk_size_in_bytes)
554 {
555         struct net_device *dev;
556         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
557         struct ethtool_cmd ecmd;
558         int err;
559         u32 speed;
560
561         rtnl_lock();
562         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
563         if (unlikely(!dev)) {
564                 rtnl_unlock();
565                 return DEFAULT_PRB_RETIRE_TOV;
566         }
567         err = __ethtool_get_settings(dev, &ecmd);
568         speed = ethtool_cmd_speed(&ecmd);
569         rtnl_unlock();
570         if (!err) {
571                 /*
572                  * If the link speed is so slow you don't really
573                  * need to worry about perf anyways
574                  */
575                 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
576                         return DEFAULT_PRB_RETIRE_TOV;
577                 } else {
578                         msec = 1;
579                         div = speed / 1000;
580                 }
581         }
582
583         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
584
585         if (div)
586                 mbits /= div;
587
588         tmo = mbits * msec;
589
590         if (div)
591                 return tmo+1;
592         return tmo;
593 }
594
595 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
596                         union tpacket_req_u *req_u)
597 {
598         p1->feature_req_word = req_u->req3.tp_feature_req_word;
599 }
600
601 static void init_prb_bdqc(struct packet_sock *po,
602                         struct packet_ring_buffer *rb,
603                         struct pgv *pg_vec,
604                         union tpacket_req_u *req_u, int tx_ring)
605 {
606         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
607         struct tpacket_block_desc *pbd;
608
609         memset(p1, 0x0, sizeof(*p1));
610
611         p1->knxt_seq_num = 1;
612         p1->pkbdq = pg_vec;
613         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
614         p1->pkblk_start = pg_vec[0].buffer;
615         p1->kblk_size = req_u->req3.tp_block_size;
616         p1->knum_blocks = req_u->req3.tp_block_nr;
617         p1->hdrlen = po->tp_hdrlen;
618         p1->version = po->tp_version;
619         p1->last_kactive_blk_num = 0;
620         po->stats.stats3.tp_freeze_q_cnt = 0;
621         if (req_u->req3.tp_retire_blk_tov)
622                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
623         else
624                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
625                                                 req_u->req3.tp_block_size);
626         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
627         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
628
629         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
630         prb_init_ft_ops(p1, req_u);
631         prb_setup_retire_blk_timer(po, tx_ring);
632         prb_open_block(p1, pbd);
633 }
634
635 /*  Do NOT update the last_blk_num first.
636  *  Assumes sk_buff_head lock is held.
637  */
638 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
639 {
640         mod_timer(&pkc->retire_blk_timer,
641                         jiffies + pkc->tov_in_jiffies);
642         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
643 }
644
645 /*
646  * Timer logic:
647  * 1) We refresh the timer only when we open a block.
648  *    By doing this we don't waste cycles refreshing the timer
649  *        on packet-by-packet basis.
650  *
651  * With a 1MB block-size, on a 1Gbps line, it will take
652  * i) ~8 ms to fill a block + ii) memcpy etc.
653  * In this cut we are not accounting for the memcpy time.
654  *
655  * So, if the user sets the 'tmo' to 10ms then the timer
656  * will never fire while the block is still getting filled
657  * (which is what we want). However, the user could choose
658  * to close a block early and that's fine.
659  *
660  * But when the timer does fire, we check whether or not to refresh it.
661  * Since the tmo granularity is in msecs, it is not too expensive
662  * to refresh the timer, lets say every '8' msecs.
663  * Either the user can set the 'tmo' or we can derive it based on
664  * a) line-speed and b) block-size.
665  * prb_calc_retire_blk_tmo() calculates the tmo.
666  *
667  */
668 static void prb_retire_rx_blk_timer_expired(unsigned long data)
669 {
670         struct packet_sock *po = (struct packet_sock *)data;
671         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
672         unsigned int frozen;
673         struct tpacket_block_desc *pbd;
674
675         spin_lock(&po->sk.sk_receive_queue.lock);
676
677         frozen = prb_queue_frozen(pkc);
678         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
679
680         if (unlikely(pkc->delete_blk_timer))
681                 goto out;
682
683         /* We only need to plug the race when the block is partially filled.
684          * tpacket_rcv:
685          *              lock(); increment BLOCK_NUM_PKTS; unlock()
686          *              copy_bits() is in progress ...
687          *              timer fires on other cpu:
688          *              we can't retire the current block because copy_bits
689          *              is in progress.
690          *
691          */
692         if (BLOCK_NUM_PKTS(pbd)) {
693                 while (atomic_read(&pkc->blk_fill_in_prog)) {
694                         /* Waiting for skb_copy_bits to finish... */
695                         cpu_relax();
696                 }
697         }
698
699         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
700                 if (!frozen) {
701                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
702                         if (!prb_dispatch_next_block(pkc, po))
703                                 goto refresh_timer;
704                         else
705                                 goto out;
706                 } else {
707                         /* Case 1. Queue was frozen because user-space was
708                          *         lagging behind.
709                          */
710                         if (prb_curr_blk_in_use(pkc, pbd)) {
711                                 /*
712                                  * Ok, user-space is still behind.
713                                  * So just refresh the timer.
714                                  */
715                                 goto refresh_timer;
716                         } else {
717                                /* Case 2. queue was frozen,user-space caught up,
718                                 * now the link went idle && the timer fired.
719                                 * We don't have a block to close.So we open this
720                                 * block and restart the timer.
721                                 * opening a block thaws the queue,restarts timer
722                                 * Thawing/timer-refresh is a side effect.
723                                 */
724                                 prb_open_block(pkc, pbd);
725                                 goto out;
726                         }
727                 }
728         }
729
730 refresh_timer:
731         _prb_refresh_rx_retire_blk_timer(pkc);
732
733 out:
734         spin_unlock(&po->sk.sk_receive_queue.lock);
735 }
736
737 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
738                 struct tpacket_block_desc *pbd1, __u32 status)
739 {
740         /* Flush everything minus the block header */
741
742 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
743         u8 *start, *end;
744
745         start = (u8 *)pbd1;
746
747         /* Skip the block header(we know header WILL fit in 4K) */
748         start += PAGE_SIZE;
749
750         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
751         for (; start < end; start += PAGE_SIZE)
752                 flush_dcache_page(pgv_to_page(start));
753
754         smp_wmb();
755 #endif
756
757         /* Now update the block status. */
758
759         BLOCK_STATUS(pbd1) = status;
760
761         /* Flush the block header */
762
763 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
764         start = (u8 *)pbd1;
765         flush_dcache_page(pgv_to_page(start));
766
767         smp_wmb();
768 #endif
769 }
770
771 /*
772  * Side effect:
773  *
774  * 1) flush the block
775  * 2) Increment active_blk_num
776  *
777  * Note:We DONT refresh the timer on purpose.
778  *      Because almost always the next block will be opened.
779  */
780 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
781                 struct tpacket_block_desc *pbd1,
782                 struct packet_sock *po, unsigned int stat)
783 {
784         __u32 status = TP_STATUS_USER | stat;
785
786         struct tpacket3_hdr *last_pkt;
787         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
788
789         if (po->stats.stats3.tp_drops)
790                 status |= TP_STATUS_LOSING;
791
792         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
793         last_pkt->tp_next_offset = 0;
794
795         /* Get the ts of the last pkt */
796         if (BLOCK_NUM_PKTS(pbd1)) {
797                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
798                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
799         } else {
800                 /* Ok, we tmo'd - so get the current time */
801                 struct timespec ts;
802                 getnstimeofday(&ts);
803                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
804                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
805         }
806
807         smp_wmb();
808
809         /* Flush the block */
810         prb_flush_block(pkc1, pbd1, status);
811
812         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
813 }
814
815 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
816 {
817         pkc->reset_pending_on_curr_blk = 0;
818 }
819
820 /*
821  * Side effect of opening a block:
822  *
823  * 1) prb_queue is thawed.
824  * 2) retire_blk_timer is refreshed.
825  *
826  */
827 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
828         struct tpacket_block_desc *pbd1)
829 {
830         struct timespec ts;
831         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
832
833         smp_rmb();
834
835         /* We could have just memset this but we will lose the
836          * flexibility of making the priv area sticky
837          */
838
839         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
840         BLOCK_NUM_PKTS(pbd1) = 0;
841         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
842
843         getnstimeofday(&ts);
844
845         h1->ts_first_pkt.ts_sec = ts.tv_sec;
846         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
847
848         pkc1->pkblk_start = (char *)pbd1;
849         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
850
851         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
852         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
853
854         pbd1->version = pkc1->version;
855         pkc1->prev = pkc1->nxt_offset;
856         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
857
858         prb_thaw_queue(pkc1);
859         _prb_refresh_rx_retire_blk_timer(pkc1);
860
861         smp_wmb();
862 }
863
864 /*
865  * Queue freeze logic:
866  * 1) Assume tp_block_nr = 8 blocks.
867  * 2) At time 't0', user opens Rx ring.
868  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
869  * 4) user-space is either sleeping or processing block '0'.
870  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
871  *    it will close block-7,loop around and try to fill block '0'.
872  *    call-flow:
873  *    __packet_lookup_frame_in_block
874  *      prb_retire_current_block()
875  *      prb_dispatch_next_block()
876  *        |->(BLOCK_STATUS == USER) evaluates to true
877  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
878  * 6) Now there are two cases:
879  *    6.1) Link goes idle right after the queue is frozen.
880  *         But remember, the last open_block() refreshed the timer.
881  *         When this timer expires,it will refresh itself so that we can
882  *         re-open block-0 in near future.
883  *    6.2) Link is busy and keeps on receiving packets. This is a simple
884  *         case and __packet_lookup_frame_in_block will check if block-0
885  *         is free and can now be re-used.
886  */
887 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
888                                   struct packet_sock *po)
889 {
890         pkc->reset_pending_on_curr_blk = 1;
891         po->stats.stats3.tp_freeze_q_cnt++;
892 }
893
894 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
895
896 /*
897  * If the next block is free then we will dispatch it
898  * and return a good offset.
899  * Else, we will freeze the queue.
900  * So, caller must check the return value.
901  */
902 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
903                 struct packet_sock *po)
904 {
905         struct tpacket_block_desc *pbd;
906
907         smp_rmb();
908
909         /* 1. Get current block num */
910         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
911
912         /* 2. If this block is currently in_use then freeze the queue */
913         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
914                 prb_freeze_queue(pkc, po);
915                 return NULL;
916         }
917
918         /*
919          * 3.
920          * open this block and return the offset where the first packet
921          * needs to get stored.
922          */
923         prb_open_block(pkc, pbd);
924         return (void *)pkc->nxt_offset;
925 }
926
927 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
928                 struct packet_sock *po, unsigned int status)
929 {
930         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
931
932         /* retire/close the current block */
933         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
934                 /*
935                  * Plug the case where copy_bits() is in progress on
936                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
937                  * have space to copy the pkt in the current block and
938                  * called prb_retire_current_block()
939                  *
940                  * We don't need to worry about the TMO case because
941                  * the timer-handler already handled this case.
942                  */
943                 if (!(status & TP_STATUS_BLK_TMO)) {
944                         while (atomic_read(&pkc->blk_fill_in_prog)) {
945                                 /* Waiting for skb_copy_bits to finish... */
946                                 cpu_relax();
947                         }
948                 }
949                 prb_close_block(pkc, pbd, po, status);
950                 return;
951         }
952 }
953
954 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
955                                       struct tpacket_block_desc *pbd)
956 {
957         return TP_STATUS_USER & BLOCK_STATUS(pbd);
958 }
959
960 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
961 {
962         return pkc->reset_pending_on_curr_blk;
963 }
964
965 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
966 {
967         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
968         atomic_dec(&pkc->blk_fill_in_prog);
969 }
970
971 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
972                         struct tpacket3_hdr *ppd)
973 {
974         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
975 }
976
977 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
978                         struct tpacket3_hdr *ppd)
979 {
980         ppd->hv1.tp_rxhash = 0;
981 }
982
983 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
984                         struct tpacket3_hdr *ppd)
985 {
986         if (vlan_tx_tag_present(pkc->skb)) {
987                 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
988                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
989                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
990         } else {
991                 ppd->hv1.tp_vlan_tci = 0;
992                 ppd->hv1.tp_vlan_tpid = 0;
993                 ppd->tp_status = TP_STATUS_AVAILABLE;
994         }
995 }
996
997 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
998                         struct tpacket3_hdr *ppd)
999 {
1000         ppd->hv1.tp_padding = 0;
1001         prb_fill_vlan_info(pkc, ppd);
1002
1003         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1004                 prb_fill_rxhash(pkc, ppd);
1005         else
1006                 prb_clear_rxhash(pkc, ppd);
1007 }
1008
1009 static void prb_fill_curr_block(char *curr,
1010                                 struct tpacket_kbdq_core *pkc,
1011                                 struct tpacket_block_desc *pbd,
1012                                 unsigned int len)
1013 {
1014         struct tpacket3_hdr *ppd;
1015
1016         ppd  = (struct tpacket3_hdr *)curr;
1017         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1018         pkc->prev = curr;
1019         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1020         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1021         BLOCK_NUM_PKTS(pbd) += 1;
1022         atomic_inc(&pkc->blk_fill_in_prog);
1023         prb_run_all_ft_ops(pkc, ppd);
1024 }
1025
1026 /* Assumes caller has the sk->rx_queue.lock */
1027 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1028                                             struct sk_buff *skb,
1029                                                 int status,
1030                                             unsigned int len
1031                                             )
1032 {
1033         struct tpacket_kbdq_core *pkc;
1034         struct tpacket_block_desc *pbd;
1035         char *curr, *end;
1036
1037         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1038         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1039
1040         /* Queue is frozen when user space is lagging behind */
1041         if (prb_queue_frozen(pkc)) {
1042                 /*
1043                  * Check if that last block which caused the queue to freeze,
1044                  * is still in_use by user-space.
1045                  */
1046                 if (prb_curr_blk_in_use(pkc, pbd)) {
1047                         /* Can't record this packet */
1048                         return NULL;
1049                 } else {
1050                         /*
1051                          * Ok, the block was released by user-space.
1052                          * Now let's open that block.
1053                          * opening a block also thaws the queue.
1054                          * Thawing is a side effect.
1055                          */
1056                         prb_open_block(pkc, pbd);
1057                 }
1058         }
1059
1060         smp_mb();
1061         curr = pkc->nxt_offset;
1062         pkc->skb = skb;
1063         end = (char *)pbd + pkc->kblk_size;
1064
1065         /* first try the current block */
1066         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1067                 prb_fill_curr_block(curr, pkc, pbd, len);
1068                 return (void *)curr;
1069         }
1070
1071         /* Ok, close the current block */
1072         prb_retire_current_block(pkc, po, 0);
1073
1074         /* Now, try to dispatch the next block */
1075         curr = (char *)prb_dispatch_next_block(pkc, po);
1076         if (curr) {
1077                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1078                 prb_fill_curr_block(curr, pkc, pbd, len);
1079                 return (void *)curr;
1080         }
1081
1082         /*
1083          * No free blocks are available.user_space hasn't caught up yet.
1084          * Queue was just frozen and now this packet will get dropped.
1085          */
1086         return NULL;
1087 }
1088
1089 static void *packet_current_rx_frame(struct packet_sock *po,
1090                                             struct sk_buff *skb,
1091                                             int status, unsigned int len)
1092 {
1093         char *curr = NULL;
1094         switch (po->tp_version) {
1095         case TPACKET_V1:
1096         case TPACKET_V2:
1097                 curr = packet_lookup_frame(po, &po->rx_ring,
1098                                         po->rx_ring.head, status);
1099                 return curr;
1100         case TPACKET_V3:
1101                 return __packet_lookup_frame_in_block(po, skb, status, len);
1102         default:
1103                 WARN(1, "TPACKET version not supported\n");
1104                 BUG();
1105                 return NULL;
1106         }
1107 }
1108
1109 static void *prb_lookup_block(struct packet_sock *po,
1110                                      struct packet_ring_buffer *rb,
1111                                      unsigned int idx,
1112                                      int status)
1113 {
1114         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1115         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1116
1117         if (status != BLOCK_STATUS(pbd))
1118                 return NULL;
1119         return pbd;
1120 }
1121
1122 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1123 {
1124         unsigned int prev;
1125         if (rb->prb_bdqc.kactive_blk_num)
1126                 prev = rb->prb_bdqc.kactive_blk_num-1;
1127         else
1128                 prev = rb->prb_bdqc.knum_blocks-1;
1129         return prev;
1130 }
1131
1132 /* Assumes caller has held the rx_queue.lock */
1133 static void *__prb_previous_block(struct packet_sock *po,
1134                                          struct packet_ring_buffer *rb,
1135                                          int status)
1136 {
1137         unsigned int previous = prb_previous_blk_num(rb);
1138         return prb_lookup_block(po, rb, previous, status);
1139 }
1140
1141 static void *packet_previous_rx_frame(struct packet_sock *po,
1142                                              struct packet_ring_buffer *rb,
1143                                              int status)
1144 {
1145         if (po->tp_version <= TPACKET_V2)
1146                 return packet_previous_frame(po, rb, status);
1147
1148         return __prb_previous_block(po, rb, status);
1149 }
1150
1151 static void packet_increment_rx_head(struct packet_sock *po,
1152                                             struct packet_ring_buffer *rb)
1153 {
1154         switch (po->tp_version) {
1155         case TPACKET_V1:
1156         case TPACKET_V2:
1157                 return packet_increment_head(rb);
1158         case TPACKET_V3:
1159         default:
1160                 WARN(1, "TPACKET version not supported.\n");
1161                 BUG();
1162                 return;
1163         }
1164 }
1165
1166 static void *packet_previous_frame(struct packet_sock *po,
1167                 struct packet_ring_buffer *rb,
1168                 int status)
1169 {
1170         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1171         return packet_lookup_frame(po, rb, previous, status);
1172 }
1173
1174 static void packet_increment_head(struct packet_ring_buffer *buff)
1175 {
1176         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1177 }
1178
1179 static void packet_inc_pending(struct packet_ring_buffer *rb)
1180 {
1181         this_cpu_inc(*rb->pending_refcnt);
1182 }
1183
1184 static void packet_dec_pending(struct packet_ring_buffer *rb)
1185 {
1186         this_cpu_dec(*rb->pending_refcnt);
1187 }
1188
1189 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1190 {
1191         unsigned int refcnt = 0;
1192         int cpu;
1193
1194         /* We don't use pending refcount in rx_ring. */
1195         if (rb->pending_refcnt == NULL)
1196                 return 0;
1197
1198         for_each_possible_cpu(cpu)
1199                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1200
1201         return refcnt;
1202 }
1203
1204 static int packet_alloc_pending(struct packet_sock *po)
1205 {
1206         po->rx_ring.pending_refcnt = NULL;
1207
1208         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1209         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1210                 return -ENOBUFS;
1211
1212         return 0;
1213 }
1214
1215 static void packet_free_pending(struct packet_sock *po)
1216 {
1217         free_percpu(po->tx_ring.pending_refcnt);
1218 }
1219
1220 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1221 {
1222         struct sock *sk = &po->sk;
1223         bool has_room;
1224
1225         if (po->prot_hook.func != tpacket_rcv)
1226                 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
1227                         <= sk->sk_rcvbuf;
1228
1229         spin_lock(&sk->sk_receive_queue.lock);
1230         if (po->tp_version == TPACKET_V3)
1231                 has_room = prb_lookup_block(po, &po->rx_ring,
1232                                             po->rx_ring.prb_bdqc.kactive_blk_num,
1233                                             TP_STATUS_KERNEL);
1234         else
1235                 has_room = packet_lookup_frame(po, &po->rx_ring,
1236                                                po->rx_ring.head,
1237                                                TP_STATUS_KERNEL);
1238         spin_unlock(&sk->sk_receive_queue.lock);
1239
1240         return has_room;
1241 }
1242
1243 static void packet_sock_destruct(struct sock *sk)
1244 {
1245         skb_queue_purge(&sk->sk_error_queue);
1246
1247         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1248         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1249
1250         if (!sock_flag(sk, SOCK_DEAD)) {
1251                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1252                 return;
1253         }
1254
1255         sk_refcnt_debug_dec(sk);
1256 }
1257
1258 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1259 {
1260         int x = atomic_read(&f->rr_cur) + 1;
1261
1262         if (x >= num)
1263                 x = 0;
1264
1265         return x;
1266 }
1267
1268 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1269                                       struct sk_buff *skb,
1270                                       unsigned int num)
1271 {
1272         return reciprocal_scale(skb_get_hash(skb), num);
1273 }
1274
1275 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1276                                     struct sk_buff *skb,
1277                                     unsigned int num)
1278 {
1279         int cur, old;
1280
1281         cur = atomic_read(&f->rr_cur);
1282         while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1283                                      fanout_rr_next(f, num))) != cur)
1284                 cur = old;
1285         return cur;
1286 }
1287
1288 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1289                                      struct sk_buff *skb,
1290                                      unsigned int num)
1291 {
1292         return smp_processor_id() % num;
1293 }
1294
1295 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1296                                      struct sk_buff *skb,
1297                                      unsigned int num)
1298 {
1299         return prandom_u32_max(num);
1300 }
1301
1302 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1303                                           struct sk_buff *skb,
1304                                           unsigned int idx, unsigned int skip,
1305                                           unsigned int num)
1306 {
1307         unsigned int i, j;
1308
1309         i = j = min_t(int, f->next[idx], num - 1);
1310         do {
1311                 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1312                         if (i != j)
1313                                 f->next[idx] = i;
1314                         return i;
1315                 }
1316                 if (++i == num)
1317                         i = 0;
1318         } while (i != j);
1319
1320         return idx;
1321 }
1322
1323 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1324                                     struct sk_buff *skb,
1325                                     unsigned int num)
1326 {
1327         return skb_get_queue_mapping(skb) % num;
1328 }
1329
1330 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1331 {
1332         return f->flags & (flag >> 8);
1333 }
1334
1335 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1336                              struct packet_type *pt, struct net_device *orig_dev)
1337 {
1338         struct packet_fanout *f = pt->af_packet_priv;
1339         unsigned int num = f->num_members;
1340         struct packet_sock *po;
1341         unsigned int idx;
1342
1343         if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1344             !num) {
1345                 kfree_skb(skb);
1346                 return 0;
1347         }
1348
1349         switch (f->type) {
1350         case PACKET_FANOUT_HASH:
1351         default:
1352                 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1353                         skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1354                         if (!skb)
1355                                 return 0;
1356                 }
1357                 idx = fanout_demux_hash(f, skb, num);
1358                 break;
1359         case PACKET_FANOUT_LB:
1360                 idx = fanout_demux_lb(f, skb, num);
1361                 break;
1362         case PACKET_FANOUT_CPU:
1363                 idx = fanout_demux_cpu(f, skb, num);
1364                 break;
1365         case PACKET_FANOUT_RND:
1366                 idx = fanout_demux_rnd(f, skb, num);
1367                 break;
1368         case PACKET_FANOUT_QM:
1369                 idx = fanout_demux_qm(f, skb, num);
1370                 break;
1371         case PACKET_FANOUT_ROLLOVER:
1372                 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1373                 break;
1374         }
1375
1376         po = pkt_sk(f->arr[idx]);
1377         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1378             unlikely(!packet_rcv_has_room(po, skb))) {
1379                 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1380                 po = pkt_sk(f->arr[idx]);
1381         }
1382
1383         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1384 }
1385
1386 DEFINE_MUTEX(fanout_mutex);
1387 EXPORT_SYMBOL_GPL(fanout_mutex);
1388 static LIST_HEAD(fanout_list);
1389
1390 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1391 {
1392         struct packet_fanout *f = po->fanout;
1393
1394         spin_lock(&f->lock);
1395         f->arr[f->num_members] = sk;
1396         smp_wmb();
1397         f->num_members++;
1398         spin_unlock(&f->lock);
1399 }
1400
1401 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1402 {
1403         struct packet_fanout *f = po->fanout;
1404         int i;
1405
1406         spin_lock(&f->lock);
1407         for (i = 0; i < f->num_members; i++) {
1408                 if (f->arr[i] == sk)
1409                         break;
1410         }
1411         BUG_ON(i >= f->num_members);
1412         f->arr[i] = f->arr[f->num_members - 1];
1413         f->num_members--;
1414         spin_unlock(&f->lock);
1415 }
1416
1417 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1418 {
1419         if (ptype->af_packet_priv == (void *)((struct packet_sock *)sk)->fanout)
1420                 return true;
1421
1422         return false;
1423 }
1424
1425 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1426 {
1427         struct packet_sock *po = pkt_sk(sk);
1428         struct packet_fanout *f, *match;
1429         u8 type = type_flags & 0xff;
1430         u8 flags = type_flags >> 8;
1431         int err;
1432
1433         switch (type) {
1434         case PACKET_FANOUT_ROLLOVER:
1435                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1436                         return -EINVAL;
1437         case PACKET_FANOUT_HASH:
1438         case PACKET_FANOUT_LB:
1439         case PACKET_FANOUT_CPU:
1440         case PACKET_FANOUT_RND:
1441         case PACKET_FANOUT_QM:
1442                 break;
1443         default:
1444                 return -EINVAL;
1445         }
1446
1447         if (!po->running)
1448                 return -EINVAL;
1449
1450         if (po->fanout)
1451                 return -EALREADY;
1452
1453         mutex_lock(&fanout_mutex);
1454         match = NULL;
1455         list_for_each_entry(f, &fanout_list, list) {
1456                 if (f->id == id &&
1457                     read_pnet(&f->net) == sock_net(sk)) {
1458                         match = f;
1459                         break;
1460                 }
1461         }
1462         err = -EINVAL;
1463         if (match && match->flags != flags)
1464                 goto out;
1465         if (!match) {
1466                 err = -ENOMEM;
1467                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1468                 if (!match)
1469                         goto out;
1470                 write_pnet(&match->net, sock_net(sk));
1471                 match->id = id;
1472                 match->type = type;
1473                 match->flags = flags;
1474                 atomic_set(&match->rr_cur, 0);
1475                 INIT_LIST_HEAD(&match->list);
1476                 spin_lock_init(&match->lock);
1477                 atomic_set(&match->sk_ref, 0);
1478                 match->prot_hook.type = po->prot_hook.type;
1479                 match->prot_hook.dev = po->prot_hook.dev;
1480                 match->prot_hook.func = packet_rcv_fanout;
1481                 match->prot_hook.af_packet_priv = match;
1482                 match->prot_hook.id_match = match_fanout_group;
1483                 dev_add_pack(&match->prot_hook);
1484                 list_add(&match->list, &fanout_list);
1485         }
1486         err = -EINVAL;
1487         if (match->type == type &&
1488             match->prot_hook.type == po->prot_hook.type &&
1489             match->prot_hook.dev == po->prot_hook.dev) {
1490                 err = -ENOSPC;
1491                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1492                         __dev_remove_pack(&po->prot_hook);
1493                         po->fanout = match;
1494                         atomic_inc(&match->sk_ref);
1495                         __fanout_link(sk, po);
1496                         err = 0;
1497                 }
1498         }
1499 out:
1500         mutex_unlock(&fanout_mutex);
1501         return err;
1502 }
1503
1504 static void fanout_release(struct sock *sk)
1505 {
1506         struct packet_sock *po = pkt_sk(sk);
1507         struct packet_fanout *f;
1508
1509         f = po->fanout;
1510         if (!f)
1511                 return;
1512
1513         mutex_lock(&fanout_mutex);
1514         po->fanout = NULL;
1515
1516         if (atomic_dec_and_test(&f->sk_ref)) {
1517                 list_del(&f->list);
1518                 dev_remove_pack(&f->prot_hook);
1519                 kfree(f);
1520         }
1521         mutex_unlock(&fanout_mutex);
1522 }
1523
1524 static const struct proto_ops packet_ops;
1525
1526 static const struct proto_ops packet_ops_spkt;
1527
1528 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1529                            struct packet_type *pt, struct net_device *orig_dev)
1530 {
1531         struct sock *sk;
1532         struct sockaddr_pkt *spkt;
1533
1534         /*
1535          *      When we registered the protocol we saved the socket in the data
1536          *      field for just this event.
1537          */
1538
1539         sk = pt->af_packet_priv;
1540
1541         /*
1542          *      Yank back the headers [hope the device set this
1543          *      right or kerboom...]
1544          *
1545          *      Incoming packets have ll header pulled,
1546          *      push it back.
1547          *
1548          *      For outgoing ones skb->data == skb_mac_header(skb)
1549          *      so that this procedure is noop.
1550          */
1551
1552         if (skb->pkt_type == PACKET_LOOPBACK)
1553                 goto out;
1554
1555         if (!net_eq(dev_net(dev), sock_net(sk)))
1556                 goto out;
1557
1558         skb = skb_share_check(skb, GFP_ATOMIC);
1559         if (skb == NULL)
1560                 goto oom;
1561
1562         /* drop any routing info */
1563         skb_dst_drop(skb);
1564
1565         /* drop conntrack reference */
1566         nf_reset(skb);
1567
1568         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1569
1570         skb_push(skb, skb->data - skb_mac_header(skb));
1571
1572         /*
1573          *      The SOCK_PACKET socket receives _all_ frames.
1574          */
1575
1576         spkt->spkt_family = dev->type;
1577         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1578         spkt->spkt_protocol = skb->protocol;
1579
1580         /*
1581          *      Charge the memory to the socket. This is done specifically
1582          *      to prevent sockets using all the memory up.
1583          */
1584
1585         if (sock_queue_rcv_skb(sk, skb) == 0)
1586                 return 0;
1587
1588 out:
1589         kfree_skb(skb);
1590 oom:
1591         return 0;
1592 }
1593
1594
1595 /*
1596  *      Output a raw packet to a device layer. This bypasses all the other
1597  *      protocol layers and you must therefore supply it with a complete frame
1598  */
1599
1600 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1601                                struct msghdr *msg, size_t len)
1602 {
1603         struct sock *sk = sock->sk;
1604         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1605         struct sk_buff *skb = NULL;
1606         struct net_device *dev;
1607         __be16 proto = 0;
1608         int err;
1609         int extra_len = 0;
1610
1611         /*
1612          *      Get and verify the address.
1613          */
1614
1615         if (saddr) {
1616                 if (msg->msg_namelen < sizeof(struct sockaddr))
1617                         return -EINVAL;
1618                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1619                         proto = saddr->spkt_protocol;
1620         } else
1621                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1622
1623         /*
1624          *      Find the device first to size check it
1625          */
1626
1627         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1628 retry:
1629         rcu_read_lock();
1630         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1631         err = -ENODEV;
1632         if (dev == NULL)
1633                 goto out_unlock;
1634
1635         err = -ENETDOWN;
1636         if (!(dev->flags & IFF_UP))
1637                 goto out_unlock;
1638
1639         /*
1640          * You may not queue a frame bigger than the mtu. This is the lowest level
1641          * raw protocol and you must do your own fragmentation at this level.
1642          */
1643
1644         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1645                 if (!netif_supports_nofcs(dev)) {
1646                         err = -EPROTONOSUPPORT;
1647                         goto out_unlock;
1648                 }
1649                 extra_len = 4; /* We're doing our own CRC */
1650         }
1651
1652         err = -EMSGSIZE;
1653         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1654                 goto out_unlock;
1655
1656         if (!skb) {
1657                 size_t reserved = LL_RESERVED_SPACE(dev);
1658                 int tlen = dev->needed_tailroom;
1659                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1660
1661                 rcu_read_unlock();
1662                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1663                 if (skb == NULL)
1664                         return -ENOBUFS;
1665                 /* FIXME: Save some space for broken drivers that write a hard
1666                  * header at transmission time by themselves. PPP is the notable
1667                  * one here. This should really be fixed at the driver level.
1668                  */
1669                 skb_reserve(skb, reserved);
1670                 skb_reset_network_header(skb);
1671
1672                 /* Try to align data part correctly */
1673                 if (hhlen) {
1674                         skb->data -= hhlen;
1675                         skb->tail -= hhlen;
1676                         if (len < hhlen)
1677                                 skb_reset_network_header(skb);
1678                 }
1679                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1680                 if (err)
1681                         goto out_free;
1682                 goto retry;
1683         }
1684
1685         if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1686                 /* Earlier code assumed this would be a VLAN pkt,
1687                  * double-check this now that we have the actual
1688                  * packet in hand.
1689                  */
1690                 struct ethhdr *ehdr;
1691                 skb_reset_mac_header(skb);
1692                 ehdr = eth_hdr(skb);
1693                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1694                         err = -EMSGSIZE;
1695                         goto out_unlock;
1696                 }
1697         }
1698
1699         skb->protocol = proto;
1700         skb->dev = dev;
1701         skb->priority = sk->sk_priority;
1702         skb->mark = sk->sk_mark;
1703
1704         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1705
1706         if (unlikely(extra_len == 4))
1707                 skb->no_fcs = 1;
1708
1709         skb_probe_transport_header(skb, 0);
1710
1711         dev_queue_xmit(skb);
1712         rcu_read_unlock();
1713         return len;
1714
1715 out_unlock:
1716         rcu_read_unlock();
1717 out_free:
1718         kfree_skb(skb);
1719         return err;
1720 }
1721
1722 static unsigned int run_filter(const struct sk_buff *skb,
1723                                       const struct sock *sk,
1724                                       unsigned int res)
1725 {
1726         struct sk_filter *filter;
1727
1728         rcu_read_lock();
1729         filter = rcu_dereference(sk->sk_filter);
1730         if (filter != NULL)
1731                 res = SK_RUN_FILTER(filter, skb);
1732         rcu_read_unlock();
1733
1734         return res;
1735 }
1736
1737 /*
1738  * This function makes lazy skb cloning in hope that most of packets
1739  * are discarded by BPF.
1740  *
1741  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1742  * and skb->cb are mangled. It works because (and until) packets
1743  * falling here are owned by current CPU. Output packets are cloned
1744  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1745  * sequencially, so that if we return skb to original state on exit,
1746  * we will not harm anyone.
1747  */
1748
1749 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1750                       struct packet_type *pt, struct net_device *orig_dev)
1751 {
1752         struct sock *sk;
1753         struct sockaddr_ll *sll;
1754         struct packet_sock *po;
1755         u8 *skb_head = skb->data;
1756         int skb_len = skb->len;
1757         unsigned int snaplen, res;
1758
1759         if (skb->pkt_type == PACKET_LOOPBACK)
1760                 goto drop;
1761
1762         sk = pt->af_packet_priv;
1763         po = pkt_sk(sk);
1764
1765         if (!net_eq(dev_net(dev), sock_net(sk)))
1766                 goto drop;
1767
1768         skb->dev = dev;
1769
1770         if (dev->header_ops) {
1771                 /* The device has an explicit notion of ll header,
1772                  * exported to higher levels.
1773                  *
1774                  * Otherwise, the device hides details of its frame
1775                  * structure, so that corresponding packet head is
1776                  * never delivered to user.
1777                  */
1778                 if (sk->sk_type != SOCK_DGRAM)
1779                         skb_push(skb, skb->data - skb_mac_header(skb));
1780                 else if (skb->pkt_type == PACKET_OUTGOING) {
1781                         /* Special case: outgoing packets have ll header at head */
1782                         skb_pull(skb, skb_network_offset(skb));
1783                 }
1784         }
1785
1786         snaplen = skb->len;
1787
1788         res = run_filter(skb, sk, snaplen);
1789         if (!res)
1790                 goto drop_n_restore;
1791         if (snaplen > res)
1792                 snaplen = res;
1793
1794         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1795                 goto drop_n_acct;
1796
1797         if (skb_shared(skb)) {
1798                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1799                 if (nskb == NULL)
1800                         goto drop_n_acct;
1801
1802                 if (skb_head != skb->data) {
1803                         skb->data = skb_head;
1804                         skb->len = skb_len;
1805                 }
1806                 consume_skb(skb);
1807                 skb = nskb;
1808         }
1809
1810         BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1811                      sizeof(skb->cb));
1812
1813         sll = &PACKET_SKB_CB(skb)->sa.ll;
1814         sll->sll_family = AF_PACKET;
1815         sll->sll_hatype = dev->type;
1816         sll->sll_protocol = skb->protocol;
1817         sll->sll_pkttype = skb->pkt_type;
1818         if (unlikely(po->origdev))
1819                 sll->sll_ifindex = orig_dev->ifindex;
1820         else
1821                 sll->sll_ifindex = dev->ifindex;
1822
1823         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1824
1825         PACKET_SKB_CB(skb)->origlen = skb->len;
1826
1827         if (pskb_trim(skb, snaplen))
1828                 goto drop_n_acct;
1829
1830         skb_set_owner_r(skb, sk);
1831         skb->dev = NULL;
1832         skb_dst_drop(skb);
1833
1834         /* drop conntrack reference */
1835         nf_reset(skb);
1836
1837         spin_lock(&sk->sk_receive_queue.lock);
1838         po->stats.stats1.tp_packets++;
1839         skb->dropcount = atomic_read(&sk->sk_drops);
1840         __skb_queue_tail(&sk->sk_receive_queue, skb);
1841         spin_unlock(&sk->sk_receive_queue.lock);
1842         sk->sk_data_ready(sk);
1843         return 0;
1844
1845 drop_n_acct:
1846         spin_lock(&sk->sk_receive_queue.lock);
1847         po->stats.stats1.tp_drops++;
1848         atomic_inc(&sk->sk_drops);
1849         spin_unlock(&sk->sk_receive_queue.lock);
1850
1851 drop_n_restore:
1852         if (skb_head != skb->data && skb_shared(skb)) {
1853                 skb->data = skb_head;
1854                 skb->len = skb_len;
1855         }
1856 drop:
1857         consume_skb(skb);
1858         return 0;
1859 }
1860
1861 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1862                        struct packet_type *pt, struct net_device *orig_dev)
1863 {
1864         struct sock *sk;
1865         struct packet_sock *po;
1866         struct sockaddr_ll *sll;
1867         union tpacket_uhdr h;
1868         u8 *skb_head = skb->data;
1869         int skb_len = skb->len;
1870         unsigned int snaplen, res;
1871         unsigned long status = TP_STATUS_USER;
1872         unsigned short macoff, netoff, hdrlen;
1873         struct sk_buff *copy_skb = NULL;
1874         struct timespec ts;
1875         __u32 ts_status;
1876
1877         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
1878          * We may add members to them until current aligned size without forcing
1879          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
1880          */
1881         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
1882         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
1883
1884         if (skb->pkt_type == PACKET_LOOPBACK)
1885                 goto drop;
1886
1887         sk = pt->af_packet_priv;
1888         po = pkt_sk(sk);
1889
1890         if (!net_eq(dev_net(dev), sock_net(sk)))
1891                 goto drop;
1892
1893         if (dev->header_ops) {
1894                 if (sk->sk_type != SOCK_DGRAM)
1895                         skb_push(skb, skb->data - skb_mac_header(skb));
1896                 else if (skb->pkt_type == PACKET_OUTGOING) {
1897                         /* Special case: outgoing packets have ll header at head */
1898                         skb_pull(skb, skb_network_offset(skb));
1899                 }
1900         }
1901
1902         if (skb->ip_summed == CHECKSUM_PARTIAL)
1903                 status |= TP_STATUS_CSUMNOTREADY;
1904
1905         snaplen = skb->len;
1906
1907         res = run_filter(skb, sk, snaplen);
1908         if (!res)
1909                 goto drop_n_restore;
1910         if (snaplen > res)
1911                 snaplen = res;
1912
1913         if (sk->sk_type == SOCK_DGRAM) {
1914                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1915                                   po->tp_reserve;
1916         } else {
1917                 unsigned int maclen = skb_network_offset(skb);
1918                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1919                                        (maclen < 16 ? 16 : maclen)) +
1920                         po->tp_reserve;
1921                 macoff = netoff - maclen;
1922         }
1923         if (po->tp_version <= TPACKET_V2) {
1924                 if (macoff + snaplen > po->rx_ring.frame_size) {
1925                         if (po->copy_thresh &&
1926                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1927                                 if (skb_shared(skb)) {
1928                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
1929                                 } else {
1930                                         copy_skb = skb_get(skb);
1931                                         skb_head = skb->data;
1932                                 }
1933                                 if (copy_skb)
1934                                         skb_set_owner_r(copy_skb, sk);
1935                         }
1936                         snaplen = po->rx_ring.frame_size - macoff;
1937                         if ((int)snaplen < 0)
1938                                 snaplen = 0;
1939                 }
1940         } else if (unlikely(macoff + snaplen >
1941                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
1942                 u32 nval;
1943
1944                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
1945                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
1946                             snaplen, nval, macoff);
1947                 snaplen = nval;
1948                 if (unlikely((int)snaplen < 0)) {
1949                         snaplen = 0;
1950                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
1951                 }
1952         }
1953         spin_lock(&sk->sk_receive_queue.lock);
1954         h.raw = packet_current_rx_frame(po, skb,
1955                                         TP_STATUS_KERNEL, (macoff+snaplen));
1956         if (!h.raw)
1957                 goto ring_is_full;
1958         if (po->tp_version <= TPACKET_V2) {
1959                 packet_increment_rx_head(po, &po->rx_ring);
1960         /*
1961          * LOSING will be reported till you read the stats,
1962          * because it's COR - Clear On Read.
1963          * Anyways, moving it for V1/V2 only as V3 doesn't need this
1964          * at packet level.
1965          */
1966                 if (po->stats.stats1.tp_drops)
1967                         status |= TP_STATUS_LOSING;
1968         }
1969         po->stats.stats1.tp_packets++;
1970         if (copy_skb) {
1971                 status |= TP_STATUS_COPY;
1972                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1973         }
1974         spin_unlock(&sk->sk_receive_queue.lock);
1975
1976         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1977
1978         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1979                 getnstimeofday(&ts);
1980
1981         status |= ts_status;
1982
1983         switch (po->tp_version) {
1984         case TPACKET_V1:
1985                 h.h1->tp_len = skb->len;
1986                 h.h1->tp_snaplen = snaplen;
1987                 h.h1->tp_mac = macoff;
1988                 h.h1->tp_net = netoff;
1989                 h.h1->tp_sec = ts.tv_sec;
1990                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1991                 hdrlen = sizeof(*h.h1);
1992                 break;
1993         case TPACKET_V2:
1994                 h.h2->tp_len = skb->len;
1995                 h.h2->tp_snaplen = snaplen;
1996                 h.h2->tp_mac = macoff;
1997                 h.h2->tp_net = netoff;
1998                 h.h2->tp_sec = ts.tv_sec;
1999                 h.h2->tp_nsec = ts.tv_nsec;
2000                 if (vlan_tx_tag_present(skb)) {
2001                         h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
2002                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2003                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2004                 } else {
2005                         h.h2->tp_vlan_tci = 0;
2006                         h.h2->tp_vlan_tpid = 0;
2007                 }
2008                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2009                 hdrlen = sizeof(*h.h2);
2010                 break;
2011         case TPACKET_V3:
2012                 /* tp_nxt_offset,vlan are already populated above.
2013                  * So DONT clear those fields here
2014                  */
2015                 h.h3->tp_status |= status;
2016                 h.h3->tp_len = skb->len;
2017                 h.h3->tp_snaplen = snaplen;
2018                 h.h3->tp_mac = macoff;
2019                 h.h3->tp_net = netoff;
2020                 h.h3->tp_sec  = ts.tv_sec;
2021                 h.h3->tp_nsec = ts.tv_nsec;
2022                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2023                 hdrlen = sizeof(*h.h3);
2024                 break;
2025         default:
2026                 BUG();
2027         }
2028
2029         sll = h.raw + TPACKET_ALIGN(hdrlen);
2030         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2031         sll->sll_family = AF_PACKET;
2032         sll->sll_hatype = dev->type;
2033         sll->sll_protocol = skb->protocol;
2034         sll->sll_pkttype = skb->pkt_type;
2035         if (unlikely(po->origdev))
2036                 sll->sll_ifindex = orig_dev->ifindex;
2037         else
2038                 sll->sll_ifindex = dev->ifindex;
2039
2040         smp_mb();
2041
2042 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2043         if (po->tp_version <= TPACKET_V2) {
2044                 u8 *start, *end;
2045
2046                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2047                                         macoff + snaplen);
2048
2049                 for (start = h.raw; start < end; start += PAGE_SIZE)
2050                         flush_dcache_page(pgv_to_page(start));
2051         }
2052         smp_wmb();
2053 #endif
2054
2055         if (po->tp_version <= TPACKET_V2)
2056                 __packet_set_status(po, h.raw, status);
2057         else
2058                 prb_clear_blk_fill_status(&po->rx_ring);
2059
2060         sk->sk_data_ready(sk);
2061
2062 drop_n_restore:
2063         if (skb_head != skb->data && skb_shared(skb)) {
2064                 skb->data = skb_head;
2065                 skb->len = skb_len;
2066         }
2067 drop:
2068         kfree_skb(skb);
2069         return 0;
2070
2071 ring_is_full:
2072         po->stats.stats1.tp_drops++;
2073         spin_unlock(&sk->sk_receive_queue.lock);
2074
2075         sk->sk_data_ready(sk);
2076         kfree_skb(copy_skb);
2077         goto drop_n_restore;
2078 }
2079
2080 static void tpacket_destruct_skb(struct sk_buff *skb)
2081 {
2082         struct packet_sock *po = pkt_sk(skb->sk);
2083
2084         if (likely(po->tx_ring.pg_vec)) {
2085                 void *ph;
2086                 __u32 ts;
2087
2088                 ph = skb_shinfo(skb)->destructor_arg;
2089                 packet_dec_pending(&po->tx_ring);
2090
2091                 ts = __packet_set_timestamp(po, ph, skb);
2092                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2093         }
2094
2095         sock_wfree(skb);
2096 }
2097
2098 static bool ll_header_truncated(const struct net_device *dev, int len)
2099 {
2100         /* net device doesn't like empty head */
2101         if (unlikely(len <= dev->hard_header_len)) {
2102                 net_warn_ratelimited("%s: packet size is too short (%d < %d)\n",
2103                                      current->comm, len, dev->hard_header_len);
2104                 return true;
2105         }
2106
2107         return false;
2108 }
2109
2110 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2111                 void *frame, struct net_device *dev, int size_max,
2112                 __be16 proto, unsigned char *addr, int hlen)
2113 {
2114         union tpacket_uhdr ph;
2115         int to_write, offset, len, tp_len, nr_frags, len_max;
2116         struct socket *sock = po->sk.sk_socket;
2117         struct page *page;
2118         void *data;
2119         int err;
2120
2121         ph.raw = frame;
2122
2123         skb->protocol = proto;
2124         skb->dev = dev;
2125         skb->priority = po->sk.sk_priority;
2126         skb->mark = po->sk.sk_mark;
2127         sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2128         skb_shinfo(skb)->destructor_arg = ph.raw;
2129
2130         switch (po->tp_version) {
2131         case TPACKET_V2:
2132                 tp_len = ph.h2->tp_len;
2133                 break;
2134         default:
2135                 tp_len = ph.h1->tp_len;
2136                 break;
2137         }
2138         if (unlikely(tp_len > size_max)) {
2139                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2140                 return -EMSGSIZE;
2141         }
2142
2143         skb_reserve(skb, hlen);
2144         skb_reset_network_header(skb);
2145
2146         if (!packet_use_direct_xmit(po))
2147                 skb_probe_transport_header(skb, 0);
2148         if (unlikely(po->tp_tx_has_off)) {
2149                 int off_min, off_max, off;
2150                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2151                 off_max = po->tx_ring.frame_size - tp_len;
2152                 if (sock->type == SOCK_DGRAM) {
2153                         switch (po->tp_version) {
2154                         case TPACKET_V2:
2155                                 off = ph.h2->tp_net;
2156                                 break;
2157                         default:
2158                                 off = ph.h1->tp_net;
2159                                 break;
2160                         }
2161                 } else {
2162                         switch (po->tp_version) {
2163                         case TPACKET_V2:
2164                                 off = ph.h2->tp_mac;
2165                                 break;
2166                         default:
2167                                 off = ph.h1->tp_mac;
2168                                 break;
2169                         }
2170                 }
2171                 if (unlikely((off < off_min) || (off_max < off)))
2172                         return -EINVAL;
2173                 data = ph.raw + off;
2174         } else {
2175                 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2176         }
2177         to_write = tp_len;
2178
2179         if (sock->type == SOCK_DGRAM) {
2180                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2181                                 NULL, tp_len);
2182                 if (unlikely(err < 0))
2183                         return -EINVAL;
2184         } else if (dev->hard_header_len) {
2185                 if (ll_header_truncated(dev, tp_len))
2186                         return -EINVAL;
2187
2188                 skb_push(skb, dev->hard_header_len);
2189                 err = skb_store_bits(skb, 0, data,
2190                                 dev->hard_header_len);
2191                 if (unlikely(err))
2192                         return err;
2193
2194                 data += dev->hard_header_len;
2195                 to_write -= dev->hard_header_len;
2196         }
2197
2198         offset = offset_in_page(data);
2199         len_max = PAGE_SIZE - offset;
2200         len = ((to_write > len_max) ? len_max : to_write);
2201
2202         skb->data_len = to_write;
2203         skb->len += to_write;
2204         skb->truesize += to_write;
2205         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2206
2207         while (likely(to_write)) {
2208                 nr_frags = skb_shinfo(skb)->nr_frags;
2209
2210                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2211                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2212                                MAX_SKB_FRAGS);
2213                         return -EFAULT;
2214                 }
2215
2216                 page = pgv_to_page(data);
2217                 data += len;
2218                 flush_dcache_page(page);
2219                 get_page(page);
2220                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2221                 to_write -= len;
2222                 offset = 0;
2223                 len_max = PAGE_SIZE;
2224                 len = ((to_write > len_max) ? len_max : to_write);
2225         }
2226
2227         return tp_len;
2228 }
2229
2230 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2231 {
2232         struct sk_buff *skb;
2233         struct net_device *dev;
2234         __be16 proto;
2235         int err, reserve = 0;
2236         void *ph;
2237         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2238         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2239         int tp_len, size_max;
2240         unsigned char *addr;
2241         int len_sum = 0;
2242         int status = TP_STATUS_AVAILABLE;
2243         int hlen, tlen;
2244
2245         mutex_lock(&po->pg_vec_lock);
2246
2247         if (likely(saddr == NULL)) {
2248                 dev     = packet_cached_dev_get(po);
2249                 proto   = po->num;
2250                 addr    = NULL;
2251         } else {
2252                 err = -EINVAL;
2253                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2254                         goto out;
2255                 if (msg->msg_namelen < (saddr->sll_halen
2256                                         + offsetof(struct sockaddr_ll,
2257                                                 sll_addr)))
2258                         goto out;
2259                 proto   = saddr->sll_protocol;
2260                 addr    = saddr->sll_addr;
2261                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2262         }
2263
2264         err = -ENXIO;
2265         if (unlikely(dev == NULL))
2266                 goto out;
2267         err = -ENETDOWN;
2268         if (unlikely(!(dev->flags & IFF_UP)))
2269                 goto out_put;
2270
2271         reserve = dev->hard_header_len + VLAN_HLEN;
2272         size_max = po->tx_ring.frame_size
2273                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2274
2275         if (size_max > dev->mtu + reserve)
2276                 size_max = dev->mtu + reserve;
2277
2278         do {
2279                 ph = packet_current_frame(po, &po->tx_ring,
2280                                           TP_STATUS_SEND_REQUEST);
2281                 if (unlikely(ph == NULL)) {
2282                         if (need_wait && need_resched())
2283                                 schedule();
2284                         continue;
2285                 }
2286
2287                 status = TP_STATUS_SEND_REQUEST;
2288                 hlen = LL_RESERVED_SPACE(dev);
2289                 tlen = dev->needed_tailroom;
2290                 skb = sock_alloc_send_skb(&po->sk,
2291                                 hlen + tlen + sizeof(struct sockaddr_ll),
2292                                 0, &err);
2293
2294                 if (unlikely(skb == NULL))
2295                         goto out_status;
2296
2297                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2298                                           addr, hlen);
2299                 if (tp_len > dev->mtu + dev->hard_header_len) {
2300                         struct ethhdr *ehdr;
2301                         /* Earlier code assumed this would be a VLAN pkt,
2302                          * double-check this now that we have the actual
2303                          * packet in hand.
2304                          */
2305
2306                         skb_reset_mac_header(skb);
2307                         ehdr = eth_hdr(skb);
2308                         if (ehdr->h_proto != htons(ETH_P_8021Q))
2309                                 tp_len = -EMSGSIZE;
2310                 }
2311                 if (unlikely(tp_len < 0)) {
2312                         if (po->tp_loss) {
2313                                 __packet_set_status(po, ph,
2314                                                 TP_STATUS_AVAILABLE);
2315                                 packet_increment_head(&po->tx_ring);
2316                                 kfree_skb(skb);
2317                                 continue;
2318                         } else {
2319                                 status = TP_STATUS_WRONG_FORMAT;
2320                                 err = tp_len;
2321                                 goto out_status;
2322                         }
2323                 }
2324
2325                 packet_pick_tx_queue(dev, skb);
2326
2327                 skb->destructor = tpacket_destruct_skb;
2328                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2329                 packet_inc_pending(&po->tx_ring);
2330
2331                 status = TP_STATUS_SEND_REQUEST;
2332                 err = po->xmit(skb);
2333                 if (unlikely(err > 0)) {
2334                         err = net_xmit_errno(err);
2335                         if (err && __packet_get_status(po, ph) ==
2336                                    TP_STATUS_AVAILABLE) {
2337                                 /* skb was destructed already */
2338                                 skb = NULL;
2339                                 goto out_status;
2340                         }
2341                         /*
2342                          * skb was dropped but not destructed yet;
2343                          * let's treat it like congestion or err < 0
2344                          */
2345                         err = 0;
2346                 }
2347                 packet_increment_head(&po->tx_ring);
2348                 len_sum += tp_len;
2349         } while (likely((ph != NULL) ||
2350                 /* Note: packet_read_pending() might be slow if we have
2351                  * to call it as it's per_cpu variable, but in fast-path
2352                  * we already short-circuit the loop with the first
2353                  * condition, and luckily don't have to go that path
2354                  * anyway.
2355                  */
2356                  (need_wait && packet_read_pending(&po->tx_ring))));
2357
2358         err = len_sum;
2359         goto out_put;
2360
2361 out_status:
2362         __packet_set_status(po, ph, status);
2363         kfree_skb(skb);
2364 out_put:
2365         dev_put(dev);
2366 out:
2367         mutex_unlock(&po->pg_vec_lock);
2368         return err;
2369 }
2370
2371 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2372                                         size_t reserve, size_t len,
2373                                         size_t linear, int noblock,
2374                                         int *err)
2375 {
2376         struct sk_buff *skb;
2377
2378         /* Under a page?  Don't bother with paged skb. */
2379         if (prepad + len < PAGE_SIZE || !linear)
2380                 linear = len;
2381
2382         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2383                                    err, 0);
2384         if (!skb)
2385                 return NULL;
2386
2387         skb_reserve(skb, reserve);
2388         skb_put(skb, linear);
2389         skb->data_len = len - linear;
2390         skb->len += len - linear;
2391
2392         return skb;
2393 }
2394
2395 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2396 {
2397         struct sock *sk = sock->sk;
2398         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2399         struct sk_buff *skb;
2400         struct net_device *dev;
2401         __be16 proto;
2402         unsigned char *addr;
2403         int err, reserve = 0;
2404         struct virtio_net_hdr vnet_hdr = { 0 };
2405         int offset = 0;
2406         int vnet_hdr_len;
2407         struct packet_sock *po = pkt_sk(sk);
2408         unsigned short gso_type = 0;
2409         int hlen, tlen;
2410         int extra_len = 0;
2411         struct iov_iter from;
2412         ssize_t n;
2413
2414         iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, len);
2415
2416         /*
2417          *      Get and verify the address.
2418          */
2419
2420         if (likely(saddr == NULL)) {
2421                 dev     = packet_cached_dev_get(po);
2422                 proto   = po->num;
2423                 addr    = NULL;
2424         } else {
2425                 err = -EINVAL;
2426                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2427                         goto out;
2428                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2429                         goto out;
2430                 proto   = saddr->sll_protocol;
2431                 addr    = saddr->sll_addr;
2432                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2433         }
2434
2435         err = -ENXIO;
2436         if (unlikely(dev == NULL))
2437                 goto out_unlock;
2438         err = -ENETDOWN;
2439         if (unlikely(!(dev->flags & IFF_UP)))
2440                 goto out_unlock;
2441
2442         if (sock->type == SOCK_RAW)
2443                 reserve = dev->hard_header_len;
2444         if (po->has_vnet_hdr) {
2445                 vnet_hdr_len = sizeof(vnet_hdr);
2446
2447                 err = -EINVAL;
2448                 if (len < vnet_hdr_len)
2449                         goto out_unlock;
2450
2451                 len -= vnet_hdr_len;
2452
2453                 err = -EFAULT;
2454                 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &from);
2455                 if (n != vnet_hdr_len)
2456                         goto out_unlock;
2457
2458                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2459                     (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2460                       vnet_hdr.hdr_len))
2461                         vnet_hdr.hdr_len = vnet_hdr.csum_start +
2462                                                  vnet_hdr.csum_offset + 2;
2463
2464                 err = -EINVAL;
2465                 if (vnet_hdr.hdr_len > len)
2466                         goto out_unlock;
2467
2468                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2469                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2470                         case VIRTIO_NET_HDR_GSO_TCPV4:
2471                                 gso_type = SKB_GSO_TCPV4;
2472                                 break;
2473                         case VIRTIO_NET_HDR_GSO_TCPV6:
2474                                 gso_type = SKB_GSO_TCPV6;
2475                                 break;
2476                         case VIRTIO_NET_HDR_GSO_UDP:
2477                                 gso_type = SKB_GSO_UDP;
2478                                 break;
2479                         default:
2480                                 goto out_unlock;
2481                         }
2482
2483                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2484                                 gso_type |= SKB_GSO_TCP_ECN;
2485
2486                         if (vnet_hdr.gso_size == 0)
2487                                 goto out_unlock;
2488
2489                 }
2490         }
2491
2492         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2493                 if (!netif_supports_nofcs(dev)) {
2494                         err = -EPROTONOSUPPORT;
2495                         goto out_unlock;
2496                 }
2497                 extra_len = 4; /* We're doing our own CRC */
2498         }
2499
2500         err = -EMSGSIZE;
2501         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2502                 goto out_unlock;
2503
2504         err = -ENOBUFS;
2505         hlen = LL_RESERVED_SPACE(dev);
2506         tlen = dev->needed_tailroom;
2507         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2508                                msg->msg_flags & MSG_DONTWAIT, &err);
2509         if (skb == NULL)
2510                 goto out_unlock;
2511
2512         skb_set_network_header(skb, reserve);
2513
2514         err = -EINVAL;
2515         if (sock->type == SOCK_DGRAM) {
2516                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2517                 if (unlikely(offset) < 0)
2518                         goto out_free;
2519         } else {
2520                 if (ll_header_truncated(dev, len))
2521                         goto out_free;
2522         }
2523
2524         /* Returns -EFAULT on error */
2525         err = skb_copy_datagram_from_iter(skb, offset, &from, len);
2526         if (err)
2527                 goto out_free;
2528
2529         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2530
2531         if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2532                 /* Earlier code assumed this would be a VLAN pkt,
2533                  * double-check this now that we have the actual
2534                  * packet in hand.
2535                  */
2536                 struct ethhdr *ehdr;
2537                 skb_reset_mac_header(skb);
2538                 ehdr = eth_hdr(skb);
2539                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2540                         err = -EMSGSIZE;
2541                         goto out_free;
2542                 }
2543         }
2544
2545         skb->protocol = proto;
2546         skb->dev = dev;
2547         skb->priority = sk->sk_priority;
2548         skb->mark = sk->sk_mark;
2549
2550         packet_pick_tx_queue(dev, skb);
2551
2552         if (po->has_vnet_hdr) {
2553                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2554                         if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2555                                                   vnet_hdr.csum_offset)) {
2556                                 err = -EINVAL;
2557                                 goto out_free;
2558                         }
2559                 }
2560
2561                 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2562                 skb_shinfo(skb)->gso_type = gso_type;
2563
2564                 /* Header must be checked, and gso_segs computed. */
2565                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2566                 skb_shinfo(skb)->gso_segs = 0;
2567
2568                 len += vnet_hdr_len;
2569         }
2570
2571         if (!packet_use_direct_xmit(po))
2572                 skb_probe_transport_header(skb, reserve);
2573         if (unlikely(extra_len == 4))
2574                 skb->no_fcs = 1;
2575
2576         err = po->xmit(skb);
2577         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2578                 goto out_unlock;
2579
2580         dev_put(dev);
2581
2582         return len;
2583
2584 out_free:
2585         kfree_skb(skb);
2586 out_unlock:
2587         if (dev)
2588                 dev_put(dev);
2589 out:
2590         return err;
2591 }
2592
2593 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2594                 struct msghdr *msg, size_t len)
2595 {
2596         struct sock *sk = sock->sk;
2597         struct packet_sock *po = pkt_sk(sk);
2598
2599         if (po->tx_ring.pg_vec)
2600                 return tpacket_snd(po, msg);
2601         else
2602                 return packet_snd(sock, msg, len);
2603 }
2604
2605 /*
2606  *      Close a PACKET socket. This is fairly simple. We immediately go
2607  *      to 'closed' state and remove our protocol entry in the device list.
2608  */
2609
2610 static int packet_release(struct socket *sock)
2611 {
2612         struct sock *sk = sock->sk;
2613         struct packet_sock *po;
2614         struct net *net;
2615         union tpacket_req_u req_u;
2616
2617         if (!sk)
2618                 return 0;
2619
2620         net = sock_net(sk);
2621         po = pkt_sk(sk);
2622
2623         mutex_lock(&net->packet.sklist_lock);
2624         sk_del_node_init_rcu(sk);
2625         mutex_unlock(&net->packet.sklist_lock);
2626
2627         preempt_disable();
2628         sock_prot_inuse_add(net, sk->sk_prot, -1);
2629         preempt_enable();
2630
2631         spin_lock(&po->bind_lock);
2632         unregister_prot_hook(sk, false);
2633         packet_cached_dev_reset(po);
2634
2635         if (po->prot_hook.dev) {
2636                 dev_put(po->prot_hook.dev);
2637                 po->prot_hook.dev = NULL;
2638         }
2639         spin_unlock(&po->bind_lock);
2640
2641         packet_flush_mclist(sk);
2642
2643         if (po->rx_ring.pg_vec) {
2644                 memset(&req_u, 0, sizeof(req_u));
2645                 packet_set_ring(sk, &req_u, 1, 0);
2646         }
2647
2648         if (po->tx_ring.pg_vec) {
2649                 memset(&req_u, 0, sizeof(req_u));
2650                 packet_set_ring(sk, &req_u, 1, 1);
2651         }
2652
2653         fanout_release(sk);
2654
2655         synchronize_net();
2656         /*
2657          *      Now the socket is dead. No more input will appear.
2658          */
2659         sock_orphan(sk);
2660         sock->sk = NULL;
2661
2662         /* Purge queues */
2663
2664         skb_queue_purge(&sk->sk_receive_queue);
2665         packet_free_pending(po);
2666         sk_refcnt_debug_release(sk);
2667
2668         sock_put(sk);
2669         return 0;
2670 }
2671
2672 /*
2673  *      Attach a packet hook.
2674  */
2675
2676 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto)
2677 {
2678         struct packet_sock *po = pkt_sk(sk);
2679         const struct net_device *dev_curr;
2680         __be16 proto_curr;
2681         bool need_rehook;
2682
2683         if (po->fanout) {
2684                 if (dev)
2685                         dev_put(dev);
2686
2687                 return -EINVAL;
2688         }
2689
2690         lock_sock(sk);
2691         spin_lock(&po->bind_lock);
2692
2693         proto_curr = po->prot_hook.type;
2694         dev_curr = po->prot_hook.dev;
2695
2696         need_rehook = proto_curr != proto || dev_curr != dev;
2697
2698         if (need_rehook) {
2699                 unregister_prot_hook(sk, true);
2700
2701                 po->num = proto;
2702                 po->prot_hook.type = proto;
2703
2704                 if (po->prot_hook.dev)
2705                         dev_put(po->prot_hook.dev);
2706
2707                 po->prot_hook.dev = dev;
2708
2709                 po->ifindex = dev ? dev->ifindex : 0;
2710                 packet_cached_dev_assign(po, dev);
2711         }
2712
2713         if (proto == 0 || !need_rehook)
2714                 goto out_unlock;
2715
2716         if (!dev || (dev->flags & IFF_UP)) {
2717                 register_prot_hook(sk);
2718         } else {
2719                 sk->sk_err = ENETDOWN;
2720                 if (!sock_flag(sk, SOCK_DEAD))
2721                         sk->sk_error_report(sk);
2722         }
2723
2724 out_unlock:
2725         spin_unlock(&po->bind_lock);
2726         release_sock(sk);
2727         return 0;
2728 }
2729
2730 /*
2731  *      Bind a packet socket to a device
2732  */
2733
2734 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2735                             int addr_len)
2736 {
2737         struct sock *sk = sock->sk;
2738         char name[15];
2739         struct net_device *dev;
2740         int err = -ENODEV;
2741
2742         /*
2743          *      Check legality
2744          */
2745
2746         if (addr_len != sizeof(struct sockaddr))
2747                 return -EINVAL;
2748         strlcpy(name, uaddr->sa_data, sizeof(name));
2749
2750         dev = dev_get_by_name(sock_net(sk), name);
2751         if (dev)
2752                 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2753         return err;
2754 }
2755
2756 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2757 {
2758         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2759         struct sock *sk = sock->sk;
2760         struct net_device *dev = NULL;
2761         int err;
2762
2763
2764         /*
2765          *      Check legality
2766          */
2767
2768         if (addr_len < sizeof(struct sockaddr_ll))
2769                 return -EINVAL;
2770         if (sll->sll_family != AF_PACKET)
2771                 return -EINVAL;
2772
2773         if (sll->sll_ifindex) {
2774                 err = -ENODEV;
2775                 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2776                 if (dev == NULL)
2777                         goto out;
2778         }
2779         err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2780
2781 out:
2782         return err;
2783 }
2784
2785 static struct proto packet_proto = {
2786         .name     = "PACKET",
2787         .owner    = THIS_MODULE,
2788         .obj_size = sizeof(struct packet_sock),
2789 };
2790
2791 /*
2792  *      Create a packet of type SOCK_PACKET.
2793  */
2794
2795 static int packet_create(struct net *net, struct socket *sock, int protocol,
2796                          int kern)
2797 {
2798         struct sock *sk;
2799         struct packet_sock *po;
2800         __be16 proto = (__force __be16)protocol; /* weird, but documented */
2801         int err;
2802
2803         if (!ns_capable(net->user_ns, CAP_NET_RAW))
2804                 return -EPERM;
2805         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2806             sock->type != SOCK_PACKET)
2807                 return -ESOCKTNOSUPPORT;
2808
2809         sock->state = SS_UNCONNECTED;
2810
2811         err = -ENOBUFS;
2812         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2813         if (sk == NULL)
2814                 goto out;
2815
2816         sock->ops = &packet_ops;
2817         if (sock->type == SOCK_PACKET)
2818                 sock->ops = &packet_ops_spkt;
2819
2820         sock_init_data(sock, sk);
2821
2822         po = pkt_sk(sk);
2823         sk->sk_family = PF_PACKET;
2824         po->num = proto;
2825         po->xmit = dev_queue_xmit;
2826
2827         err = packet_alloc_pending(po);
2828         if (err)
2829                 goto out2;
2830
2831         packet_cached_dev_reset(po);
2832
2833         sk->sk_destruct = packet_sock_destruct;
2834         sk_refcnt_debug_inc(sk);
2835
2836         /*
2837          *      Attach a protocol block
2838          */
2839
2840         spin_lock_init(&po->bind_lock);
2841         mutex_init(&po->pg_vec_lock);
2842         po->prot_hook.func = packet_rcv;
2843
2844         if (sock->type == SOCK_PACKET)
2845                 po->prot_hook.func = packet_rcv_spkt;
2846
2847         po->prot_hook.af_packet_priv = sk;
2848
2849         if (proto) {
2850                 po->prot_hook.type = proto;
2851                 register_prot_hook(sk);
2852         }
2853
2854         mutex_lock(&net->packet.sklist_lock);
2855         sk_add_node_rcu(sk, &net->packet.sklist);
2856         mutex_unlock(&net->packet.sklist_lock);
2857
2858         preempt_disable();
2859         sock_prot_inuse_add(net, &packet_proto, 1);
2860         preempt_enable();
2861
2862         return 0;
2863 out2:
2864         sk_free(sk);
2865 out:
2866         return err;
2867 }
2868
2869 /*
2870  *      Pull a packet from our receive queue and hand it to the user.
2871  *      If necessary we block.
2872  */
2873
2874 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2875                           struct msghdr *msg, size_t len, int flags)
2876 {
2877         struct sock *sk = sock->sk;
2878         struct sk_buff *skb;
2879         int copied, err;
2880         int vnet_hdr_len = 0;
2881
2882         err = -EINVAL;
2883         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2884                 goto out;
2885
2886 #if 0
2887         /* What error should we return now? EUNATTACH? */
2888         if (pkt_sk(sk)->ifindex < 0)
2889                 return -ENODEV;
2890 #endif
2891
2892         if (flags & MSG_ERRQUEUE) {
2893                 err = sock_recv_errqueue(sk, msg, len,
2894                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
2895                 goto out;
2896         }
2897
2898         /*
2899          *      Call the generic datagram receiver. This handles all sorts
2900          *      of horrible races and re-entrancy so we can forget about it
2901          *      in the protocol layers.
2902          *
2903          *      Now it will return ENETDOWN, if device have just gone down,
2904          *      but then it will block.
2905          */
2906
2907         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2908
2909         /*
2910          *      An error occurred so return it. Because skb_recv_datagram()
2911          *      handles the blocking we don't see and worry about blocking
2912          *      retries.
2913          */
2914
2915         if (skb == NULL)
2916                 goto out;
2917
2918         if (pkt_sk(sk)->has_vnet_hdr) {
2919                 struct virtio_net_hdr vnet_hdr = { 0 };
2920
2921                 err = -EINVAL;
2922                 vnet_hdr_len = sizeof(vnet_hdr);
2923                 if (len < vnet_hdr_len)
2924                         goto out_free;
2925
2926                 len -= vnet_hdr_len;
2927
2928                 if (skb_is_gso(skb)) {
2929                         struct skb_shared_info *sinfo = skb_shinfo(skb);
2930
2931                         /* This is a hint as to how much should be linear. */
2932                         vnet_hdr.hdr_len = skb_headlen(skb);
2933                         vnet_hdr.gso_size = sinfo->gso_size;
2934                         if (sinfo->gso_type & SKB_GSO_TCPV4)
2935                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2936                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
2937                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2938                         else if (sinfo->gso_type & SKB_GSO_UDP)
2939                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2940                         else if (sinfo->gso_type & SKB_GSO_FCOE)
2941                                 goto out_free;
2942                         else
2943                                 BUG();
2944                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2945                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2946                 } else
2947                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2948
2949                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2950                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2951                         vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2952                         vnet_hdr.csum_offset = skb->csum_offset;
2953                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2954                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2955                 } /* else everything is zero */
2956
2957                 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len);
2958                 if (err < 0)
2959                         goto out_free;
2960         }
2961
2962         /* You lose any data beyond the buffer you gave. If it worries
2963          * a user program they can ask the device for its MTU
2964          * anyway.
2965          */
2966         copied = skb->len;
2967         if (copied > len) {
2968                 copied = len;
2969                 msg->msg_flags |= MSG_TRUNC;
2970         }
2971
2972         err = skb_copy_datagram_msg(skb, 0, msg, copied);
2973         if (err)
2974                 goto out_free;
2975
2976         sock_recv_ts_and_drops(msg, sk, skb);
2977
2978         if (msg->msg_name) {
2979                 /* If the address length field is there to be filled
2980                  * in, we fill it in now.
2981                  */
2982                 if (sock->type == SOCK_PACKET) {
2983                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
2984                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
2985                 } else {
2986                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
2987                         msg->msg_namelen = sll->sll_halen +
2988                                 offsetof(struct sockaddr_ll, sll_addr);
2989                 }
2990                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2991                        msg->msg_namelen);
2992         }
2993
2994         if (pkt_sk(sk)->auxdata) {
2995                 struct tpacket_auxdata aux;
2996
2997                 aux.tp_status = TP_STATUS_USER;
2998                 if (skb->ip_summed == CHECKSUM_PARTIAL)
2999                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3000                 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
3001                 aux.tp_snaplen = skb->len;
3002                 aux.tp_mac = 0;
3003                 aux.tp_net = skb_network_offset(skb);
3004                 if (vlan_tx_tag_present(skb)) {
3005                         aux.tp_vlan_tci = vlan_tx_tag_get(skb);
3006                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3007                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3008                 } else {
3009                         aux.tp_vlan_tci = 0;
3010                         aux.tp_vlan_tpid = 0;
3011                 }
3012                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3013         }
3014
3015         /*
3016          *      Free or return the buffer as appropriate. Again this
3017          *      hides all the races and re-entrancy issues from us.
3018          */
3019         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3020
3021 out_free:
3022         skb_free_datagram(sk, skb);
3023 out:
3024         return err;
3025 }
3026
3027 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3028                                int *uaddr_len, int peer)
3029 {
3030         struct net_device *dev;
3031         struct sock *sk = sock->sk;
3032
3033         if (peer)
3034                 return -EOPNOTSUPP;
3035
3036         uaddr->sa_family = AF_PACKET;
3037         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3038         rcu_read_lock();
3039         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3040         if (dev)
3041                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3042         rcu_read_unlock();
3043         *uaddr_len = sizeof(*uaddr);
3044
3045         return 0;
3046 }
3047
3048 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3049                           int *uaddr_len, int peer)
3050 {
3051         struct net_device *dev;
3052         struct sock *sk = sock->sk;
3053         struct packet_sock *po = pkt_sk(sk);
3054         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3055
3056         if (peer)
3057                 return -EOPNOTSUPP;
3058
3059         sll->sll_family = AF_PACKET;
3060         sll->sll_ifindex = po->ifindex;
3061         sll->sll_protocol = po->num;
3062         sll->sll_pkttype = 0;
3063         rcu_read_lock();
3064         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3065         if (dev) {
3066                 sll->sll_hatype = dev->type;
3067                 sll->sll_halen = dev->addr_len;
3068                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3069         } else {
3070                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3071                 sll->sll_halen = 0;
3072         }
3073         rcu_read_unlock();
3074         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3075
3076         return 0;
3077 }
3078
3079 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3080                          int what)
3081 {
3082         switch (i->type) {
3083         case PACKET_MR_MULTICAST:
3084                 if (i->alen != dev->addr_len)
3085                         return -EINVAL;
3086                 if (what > 0)
3087                         return dev_mc_add(dev, i->addr);
3088                 else
3089                         return dev_mc_del(dev, i->addr);
3090                 break;
3091         case PACKET_MR_PROMISC:
3092                 return dev_set_promiscuity(dev, what);
3093         case PACKET_MR_ALLMULTI:
3094                 return dev_set_allmulti(dev, what);
3095         case PACKET_MR_UNICAST:
3096                 if (i->alen != dev->addr_len)
3097                         return -EINVAL;
3098                 if (what > 0)
3099                         return dev_uc_add(dev, i->addr);
3100                 else
3101                         return dev_uc_del(dev, i->addr);
3102                 break;
3103         default:
3104                 break;
3105         }
3106         return 0;
3107 }
3108
3109 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
3110 {
3111         for ( ; i; i = i->next) {
3112                 if (i->ifindex == dev->ifindex)
3113                         packet_dev_mc(dev, i, what);
3114         }
3115 }
3116
3117 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3118 {
3119         struct packet_sock *po = pkt_sk(sk);
3120         struct packet_mclist *ml, *i;
3121         struct net_device *dev;
3122         int err;
3123
3124         rtnl_lock();
3125
3126         err = -ENODEV;
3127         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3128         if (!dev)
3129                 goto done;
3130
3131         err = -EINVAL;
3132         if (mreq->mr_alen > dev->addr_len)
3133                 goto done;
3134
3135         err = -ENOBUFS;
3136         i = kmalloc(sizeof(*i), GFP_KERNEL);
3137         if (i == NULL)
3138                 goto done;
3139
3140         err = 0;
3141         for (ml = po->mclist; ml; ml = ml->next) {
3142                 if (ml->ifindex == mreq->mr_ifindex &&
3143                     ml->type == mreq->mr_type &&
3144                     ml->alen == mreq->mr_alen &&
3145                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3146                         ml->count++;
3147                         /* Free the new element ... */
3148                         kfree(i);
3149                         goto done;
3150                 }
3151         }
3152
3153         i->type = mreq->mr_type;
3154         i->ifindex = mreq->mr_ifindex;
3155         i->alen = mreq->mr_alen;
3156         memcpy(i->addr, mreq->mr_address, i->alen);
3157         i->count = 1;
3158         i->next = po->mclist;
3159         po->mclist = i;
3160         err = packet_dev_mc(dev, i, 1);
3161         if (err) {
3162                 po->mclist = i->next;
3163                 kfree(i);
3164         }
3165
3166 done:
3167         rtnl_unlock();
3168         return err;
3169 }
3170
3171 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3172 {
3173         struct packet_mclist *ml, **mlp;
3174
3175         rtnl_lock();
3176
3177         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3178                 if (ml->ifindex == mreq->mr_ifindex &&
3179                     ml->type == mreq->mr_type &&
3180                     ml->alen == mreq->mr_alen &&
3181                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3182                         if (--ml->count == 0) {
3183                                 struct net_device *dev;
3184                                 *mlp = ml->next;
3185                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3186                                 if (dev)
3187                                         packet_dev_mc(dev, ml, -1);
3188                                 kfree(ml);
3189                         }
3190                         rtnl_unlock();
3191                         return 0;
3192                 }
3193         }
3194         rtnl_unlock();
3195         return -EADDRNOTAVAIL;
3196 }
3197
3198 static void packet_flush_mclist(struct sock *sk)
3199 {
3200         struct packet_sock *po = pkt_sk(sk);
3201         struct packet_mclist *ml;
3202
3203         if (!po->mclist)
3204                 return;
3205
3206         rtnl_lock();
3207         while ((ml = po->mclist) != NULL) {
3208                 struct net_device *dev;
3209
3210                 po->mclist = ml->next;
3211                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3212                 if (dev != NULL)
3213                         packet_dev_mc(dev, ml, -1);
3214                 kfree(ml);
3215         }
3216         rtnl_unlock();
3217 }
3218
3219 static int
3220 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3221 {
3222         struct sock *sk = sock->sk;
3223         struct packet_sock *po = pkt_sk(sk);
3224         int ret;
3225
3226         if (level != SOL_PACKET)
3227                 return -ENOPROTOOPT;
3228
3229         switch (optname) {
3230         case PACKET_ADD_MEMBERSHIP:
3231         case PACKET_DROP_MEMBERSHIP:
3232         {
3233                 struct packet_mreq_max mreq;
3234                 int len = optlen;
3235                 memset(&mreq, 0, sizeof(mreq));
3236                 if (len < sizeof(struct packet_mreq))
3237                         return -EINVAL;
3238                 if (len > sizeof(mreq))
3239                         len = sizeof(mreq);
3240                 if (copy_from_user(&mreq, optval, len))
3241                         return -EFAULT;
3242                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3243                         return -EINVAL;
3244                 if (optname == PACKET_ADD_MEMBERSHIP)
3245                         ret = packet_mc_add(sk, &mreq);
3246                 else
3247                         ret = packet_mc_drop(sk, &mreq);
3248                 return ret;
3249         }
3250
3251         case PACKET_RX_RING:
3252         case PACKET_TX_RING:
3253         {
3254                 union tpacket_req_u req_u;
3255                 int len;
3256
3257                 switch (po->tp_version) {
3258                 case TPACKET_V1:
3259                 case TPACKET_V2:
3260                         len = sizeof(req_u.req);
3261                         break;
3262                 case TPACKET_V3:
3263                 default:
3264                         len = sizeof(req_u.req3);
3265                         break;
3266                 }
3267                 if (optlen < len)
3268                         return -EINVAL;
3269                 if (pkt_sk(sk)->has_vnet_hdr)
3270                         return -EINVAL;
3271                 if (copy_from_user(&req_u.req, optval, len))
3272                         return -EFAULT;
3273                 return packet_set_ring(sk, &req_u, 0,
3274                         optname == PACKET_TX_RING);
3275         }
3276         case PACKET_COPY_THRESH:
3277         {
3278                 int val;
3279
3280                 if (optlen != sizeof(val))
3281                         return -EINVAL;
3282                 if (copy_from_user(&val, optval, sizeof(val)))
3283                         return -EFAULT;
3284
3285                 pkt_sk(sk)->copy_thresh = val;
3286                 return 0;
3287         }
3288         case PACKET_VERSION:
3289         {
3290                 int val;
3291
3292                 if (optlen != sizeof(val))
3293                         return -EINVAL;
3294                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3295                         return -EBUSY;
3296                 if (copy_from_user(&val, optval, sizeof(val)))
3297                         return -EFAULT;
3298                 switch (val) {
3299                 case TPACKET_V1:
3300                 case TPACKET_V2:
3301                 case TPACKET_V3:
3302                         po->tp_version = val;
3303                         return 0;
3304                 default:
3305                         return -EINVAL;
3306                 }
3307         }
3308         case PACKET_RESERVE:
3309         {
3310                 unsigned int val;
3311
3312                 if (optlen != sizeof(val))
3313                         return -EINVAL;
3314                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3315                         return -EBUSY;
3316                 if (copy_from_user(&val, optval, sizeof(val)))
3317                         return -EFAULT;
3318                 po->tp_reserve = val;
3319                 return 0;
3320         }
3321         case PACKET_LOSS:
3322         {
3323                 unsigned int val;
3324
3325                 if (optlen != sizeof(val))
3326                         return -EINVAL;
3327                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3328                         return -EBUSY;
3329                 if (copy_from_user(&val, optval, sizeof(val)))
3330                         return -EFAULT;
3331                 po->tp_loss = !!val;
3332                 return 0;
3333         }
3334         case PACKET_AUXDATA:
3335         {
3336                 int val;
3337
3338                 if (optlen < sizeof(val))
3339                         return -EINVAL;
3340                 if (copy_from_user(&val, optval, sizeof(val)))
3341                         return -EFAULT;
3342
3343                 po->auxdata = !!val;
3344                 return 0;
3345         }
3346         case PACKET_ORIGDEV:
3347         {
3348                 int val;
3349
3350                 if (optlen < sizeof(val))
3351                         return -EINVAL;
3352                 if (copy_from_user(&val, optval, sizeof(val)))
3353                         return -EFAULT;
3354
3355                 po->origdev = !!val;
3356                 return 0;
3357         }
3358         case PACKET_VNET_HDR:
3359         {
3360                 int val;
3361
3362                 if (sock->type != SOCK_RAW)
3363                         return -EINVAL;
3364                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3365                         return -EBUSY;
3366                 if (optlen < sizeof(val))
3367                         return -EINVAL;
3368                 if (copy_from_user(&val, optval, sizeof(val)))
3369                         return -EFAULT;
3370
3371                 po->has_vnet_hdr = !!val;
3372                 return 0;
3373         }
3374         case PACKET_TIMESTAMP:
3375         {
3376                 int val;
3377
3378                 if (optlen != sizeof(val))
3379                         return -EINVAL;
3380                 if (copy_from_user(&val, optval, sizeof(val)))
3381                         return -EFAULT;
3382
3383                 po->tp_tstamp = val;
3384                 return 0;
3385         }
3386         case PACKET_FANOUT:
3387         {
3388                 int val;
3389
3390                 if (optlen != sizeof(val))
3391                         return -EINVAL;
3392                 if (copy_from_user(&val, optval, sizeof(val)))
3393                         return -EFAULT;
3394
3395                 return fanout_add(sk, val & 0xffff, val >> 16);
3396         }
3397         case PACKET_TX_HAS_OFF:
3398         {
3399                 unsigned int val;
3400
3401                 if (optlen != sizeof(val))
3402                         return -EINVAL;
3403                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3404                         return -EBUSY;
3405                 if (copy_from_user(&val, optval, sizeof(val)))
3406                         return -EFAULT;
3407                 po->tp_tx_has_off = !!val;
3408                 return 0;
3409         }
3410         case PACKET_QDISC_BYPASS:
3411         {
3412                 int val;
3413
3414                 if (optlen != sizeof(val))
3415                         return -EINVAL;
3416                 if (copy_from_user(&val, optval, sizeof(val)))
3417                         return -EFAULT;
3418
3419                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3420                 return 0;
3421         }
3422         default:
3423                 return -ENOPROTOOPT;
3424         }
3425 }
3426
3427 static int packet_getsockopt(struct socket *sock, int level, int optname,
3428                              char __user *optval, int __user *optlen)
3429 {
3430         int len;
3431         int val, lv = sizeof(val);
3432         struct sock *sk = sock->sk;
3433         struct packet_sock *po = pkt_sk(sk);
3434         void *data = &val;
3435         union tpacket_stats_u st;
3436
3437         if (level != SOL_PACKET)
3438                 return -ENOPROTOOPT;
3439
3440         if (get_user(len, optlen))
3441                 return -EFAULT;
3442
3443         if (len < 0)
3444                 return -EINVAL;
3445
3446         switch (optname) {
3447         case PACKET_STATISTICS:
3448                 spin_lock_bh(&sk->sk_receive_queue.lock);
3449                 memcpy(&st, &po->stats, sizeof(st));
3450                 memset(&po->stats, 0, sizeof(po->stats));
3451                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3452
3453                 if (po->tp_version == TPACKET_V3) {
3454                         lv = sizeof(struct tpacket_stats_v3);
3455                         st.stats3.tp_packets += st.stats3.tp_drops;
3456                         data = &st.stats3;
3457                 } else {
3458                         lv = sizeof(struct tpacket_stats);
3459                         st.stats1.tp_packets += st.stats1.tp_drops;
3460                         data = &st.stats1;
3461                 }
3462
3463                 break;
3464         case PACKET_AUXDATA:
3465                 val = po->auxdata;
3466                 break;
3467         case PACKET_ORIGDEV:
3468                 val = po->origdev;
3469                 break;
3470         case PACKET_VNET_HDR:
3471                 val = po->has_vnet_hdr;
3472                 break;
3473         case PACKET_VERSION:
3474                 val = po->tp_version;
3475                 break;
3476         case PACKET_HDRLEN:
3477                 if (len > sizeof(int))
3478                         len = sizeof(int);
3479                 if (copy_from_user(&val, optval, len))
3480                         return -EFAULT;
3481                 switch (val) {
3482                 case TPACKET_V1:
3483                         val = sizeof(struct tpacket_hdr);
3484                         break;
3485                 case TPACKET_V2:
3486                         val = sizeof(struct tpacket2_hdr);
3487                         break;
3488                 case TPACKET_V3:
3489                         val = sizeof(struct tpacket3_hdr);
3490                         break;
3491                 default:
3492                         return -EINVAL;
3493                 }
3494                 break;
3495         case PACKET_RESERVE:
3496                 val = po->tp_reserve;
3497                 break;
3498         case PACKET_LOSS:
3499                 val = po->tp_loss;
3500                 break;
3501         case PACKET_TIMESTAMP:
3502                 val = po->tp_tstamp;
3503                 break;
3504         case PACKET_FANOUT:
3505                 val = (po->fanout ?
3506                        ((u32)po->fanout->id |
3507                         ((u32)po->fanout->type << 16) |
3508                         ((u32)po->fanout->flags << 24)) :
3509                        0);
3510                 break;
3511         case PACKET_TX_HAS_OFF:
3512                 val = po->tp_tx_has_off;
3513                 break;
3514         case PACKET_QDISC_BYPASS:
3515                 val = packet_use_direct_xmit(po);
3516                 break;
3517         default:
3518                 return -ENOPROTOOPT;
3519         }
3520
3521         if (len > lv)
3522                 len = lv;
3523         if (put_user(len, optlen))
3524                 return -EFAULT;
3525         if (copy_to_user(optval, data, len))
3526                 return -EFAULT;
3527         return 0;
3528 }
3529
3530
3531 static int packet_notifier(struct notifier_block *this,
3532                            unsigned long msg, void *ptr)
3533 {
3534         struct sock *sk;
3535         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3536         struct net *net = dev_net(dev);
3537
3538         rcu_read_lock();
3539         sk_for_each_rcu(sk, &net->packet.sklist) {
3540                 struct packet_sock *po = pkt_sk(sk);
3541
3542                 switch (msg) {
3543                 case NETDEV_UNREGISTER:
3544                         if (po->mclist)
3545                                 packet_dev_mclist(dev, po->mclist, -1);
3546                         /* fallthrough */
3547
3548                 case NETDEV_DOWN:
3549                         if (dev->ifindex == po->ifindex) {
3550                                 spin_lock(&po->bind_lock);
3551                                 if (po->running) {
3552                                         __unregister_prot_hook(sk, false);
3553                                         sk->sk_err = ENETDOWN;
3554                                         if (!sock_flag(sk, SOCK_DEAD))
3555                                                 sk->sk_error_report(sk);
3556                                 }
3557                                 if (msg == NETDEV_UNREGISTER) {
3558                                         packet_cached_dev_reset(po);
3559                                         po->ifindex = -1;
3560                                         if (po->prot_hook.dev)
3561                                                 dev_put(po->prot_hook.dev);
3562                                         po->prot_hook.dev = NULL;
3563                                 }
3564                                 spin_unlock(&po->bind_lock);
3565                         }
3566                         break;
3567                 case NETDEV_UP:
3568                         if (dev->ifindex == po->ifindex) {
3569                                 spin_lock(&po->bind_lock);
3570                                 if (po->num)
3571                                         register_prot_hook(sk);
3572                                 spin_unlock(&po->bind_lock);
3573                         }
3574                         break;
3575                 }
3576         }
3577         rcu_read_unlock();
3578         return NOTIFY_DONE;
3579 }
3580
3581
3582 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3583                         unsigned long arg)
3584 {
3585         struct sock *sk = sock->sk;
3586
3587         switch (cmd) {
3588         case SIOCOUTQ:
3589         {
3590                 int amount = sk_wmem_alloc_get(sk);
3591
3592                 return put_user(amount, (int __user *)arg);
3593         }
3594         case SIOCINQ:
3595         {
3596                 struct sk_buff *skb;
3597                 int amount = 0;
3598
3599                 spin_lock_bh(&sk->sk_receive_queue.lock);
3600                 skb = skb_peek(&sk->sk_receive_queue);
3601                 if (skb)
3602                         amount = skb->len;
3603                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3604                 return put_user(amount, (int __user *)arg);
3605         }
3606         case SIOCGSTAMP:
3607                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3608         case SIOCGSTAMPNS:
3609                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3610
3611 #ifdef CONFIG_INET
3612         case SIOCADDRT:
3613         case SIOCDELRT:
3614         case SIOCDARP:
3615         case SIOCGARP:
3616         case SIOCSARP:
3617         case SIOCGIFADDR:
3618         case SIOCSIFADDR:
3619         case SIOCGIFBRDADDR:
3620         case SIOCSIFBRDADDR:
3621         case SIOCGIFNETMASK:
3622         case SIOCSIFNETMASK:
3623         case SIOCGIFDSTADDR:
3624         case SIOCSIFDSTADDR:
3625         case SIOCSIFFLAGS:
3626                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3627 #endif
3628
3629         default:
3630                 return -ENOIOCTLCMD;
3631         }
3632         return 0;
3633 }
3634
3635 static unsigned int packet_poll(struct file *file, struct socket *sock,
3636                                 poll_table *wait)
3637 {
3638         struct sock *sk = sock->sk;
3639         struct packet_sock *po = pkt_sk(sk);
3640         unsigned int mask = datagram_poll(file, sock, wait);
3641
3642         spin_lock_bh(&sk->sk_receive_queue.lock);
3643         if (po->rx_ring.pg_vec) {
3644                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3645                         TP_STATUS_KERNEL))
3646                         mask |= POLLIN | POLLRDNORM;
3647         }
3648         spin_unlock_bh(&sk->sk_receive_queue.lock);
3649         spin_lock_bh(&sk->sk_write_queue.lock);
3650         if (po->tx_ring.pg_vec) {
3651                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3652                         mask |= POLLOUT | POLLWRNORM;
3653         }
3654         spin_unlock_bh(&sk->sk_write_queue.lock);
3655         return mask;
3656 }
3657
3658
3659 /* Dirty? Well, I still did not learn better way to account
3660  * for user mmaps.
3661  */
3662
3663 static void packet_mm_open(struct vm_area_struct *vma)
3664 {
3665         struct file *file = vma->vm_file;
3666         struct socket *sock = file->private_data;
3667         struct sock *sk = sock->sk;
3668
3669         if (sk)
3670                 atomic_inc(&pkt_sk(sk)->mapped);
3671 }
3672
3673 static void packet_mm_close(struct vm_area_struct *vma)
3674 {
3675         struct file *file = vma->vm_file;
3676         struct socket *sock = file->private_data;
3677         struct sock *sk = sock->sk;
3678
3679         if (sk)
3680                 atomic_dec(&pkt_sk(sk)->mapped);
3681 }
3682
3683 static const struct vm_operations_struct packet_mmap_ops = {
3684         .open   =       packet_mm_open,
3685         .close  =       packet_mm_close,
3686 };
3687
3688 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3689                         unsigned int len)
3690 {
3691         int i;
3692
3693         for (i = 0; i < len; i++) {
3694                 if (likely(pg_vec[i].buffer)) {
3695                         if (is_vmalloc_addr(pg_vec[i].buffer))
3696                                 vfree(pg_vec[i].buffer);
3697                         else
3698                                 free_pages((unsigned long)pg_vec[i].buffer,
3699                                            order);
3700                         pg_vec[i].buffer = NULL;
3701                 }
3702         }
3703         kfree(pg_vec);
3704 }
3705
3706 static char *alloc_one_pg_vec_page(unsigned long order)
3707 {
3708         char *buffer;
3709         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3710                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3711
3712         buffer = (char *) __get_free_pages(gfp_flags, order);
3713         if (buffer)
3714                 return buffer;
3715
3716         /* __get_free_pages failed, fall back to vmalloc */
3717         buffer = vzalloc((1 << order) * PAGE_SIZE);
3718         if (buffer)
3719                 return buffer;
3720
3721         /* vmalloc failed, lets dig into swap here */
3722         gfp_flags &= ~__GFP_NORETRY;
3723         buffer = (char *) __get_free_pages(gfp_flags, order);
3724         if (buffer)
3725                 return buffer;
3726
3727         /* complete and utter failure */
3728         return NULL;
3729 }
3730
3731 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3732 {
3733         unsigned int block_nr = req->tp_block_nr;
3734         struct pgv *pg_vec;
3735         int i;
3736
3737         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3738         if (unlikely(!pg_vec))
3739                 goto out;
3740
3741         for (i = 0; i < block_nr; i++) {
3742                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3743                 if (unlikely(!pg_vec[i].buffer))
3744                         goto out_free_pgvec;
3745         }
3746
3747 out:
3748         return pg_vec;
3749
3750 out_free_pgvec:
3751         free_pg_vec(pg_vec, order, block_nr);
3752         pg_vec = NULL;
3753         goto out;
3754 }
3755
3756 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3757                 int closing, int tx_ring)
3758 {
3759         struct pgv *pg_vec = NULL;
3760         struct packet_sock *po = pkt_sk(sk);
3761         int was_running, order = 0;
3762         struct packet_ring_buffer *rb;
3763         struct sk_buff_head *rb_queue;
3764         __be16 num;
3765         int err = -EINVAL;
3766         /* Added to avoid minimal code churn */
3767         struct tpacket_req *req = &req_u->req;
3768
3769         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3770         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3771                 WARN(1, "Tx-ring is not supported.\n");
3772                 goto out;
3773         }
3774
3775         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3776         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3777
3778         err = -EBUSY;
3779         if (!closing) {
3780                 if (atomic_read(&po->mapped))
3781                         goto out;
3782                 if (packet_read_pending(rb))
3783                         goto out;
3784         }
3785
3786         if (req->tp_block_nr) {
3787                 /* Sanity tests and some calculations */
3788                 err = -EBUSY;
3789                 if (unlikely(rb->pg_vec))
3790                         goto out;
3791
3792                 switch (po->tp_version) {
3793                 case TPACKET_V1:
3794                         po->tp_hdrlen = TPACKET_HDRLEN;
3795                         break;
3796                 case TPACKET_V2:
3797                         po->tp_hdrlen = TPACKET2_HDRLEN;
3798                         break;
3799                 case TPACKET_V3:
3800                         po->tp_hdrlen = TPACKET3_HDRLEN;
3801                         break;
3802                 }
3803
3804                 err = -EINVAL;
3805                 if (unlikely((int)req->tp_block_size <= 0))
3806                         goto out;
3807                 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3808                         goto out;
3809                 if (po->tp_version >= TPACKET_V3 &&
3810                     (int)(req->tp_block_size -
3811                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
3812                         goto out;
3813                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3814                                         po->tp_reserve))
3815                         goto out;
3816                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3817                         goto out;
3818
3819                 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3820                 if (unlikely(rb->frames_per_block <= 0))
3821                         goto out;
3822                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3823                                         req->tp_frame_nr))
3824                         goto out;
3825
3826                 err = -ENOMEM;
3827                 order = get_order(req->tp_block_size);
3828                 pg_vec = alloc_pg_vec(req, order);
3829                 if (unlikely(!pg_vec))
3830                         goto out;
3831                 switch (po->tp_version) {
3832                 case TPACKET_V3:
3833                 /* Transmit path is not supported. We checked
3834                  * it above but just being paranoid
3835                  */
3836                         if (!tx_ring)
3837                                 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3838                         break;
3839                 default:
3840                         break;
3841                 }
3842         }
3843         /* Done */
3844         else {
3845                 err = -EINVAL;
3846                 if (unlikely(req->tp_frame_nr))
3847                         goto out;
3848         }
3849
3850         lock_sock(sk);
3851
3852         /* Detach socket from network */
3853         spin_lock(&po->bind_lock);
3854         was_running = po->running;
3855         num = po->num;
3856         if (was_running) {
3857                 po->num = 0;
3858                 __unregister_prot_hook(sk, false);
3859         }
3860         spin_unlock(&po->bind_lock);
3861
3862         synchronize_net();
3863
3864         err = -EBUSY;
3865         mutex_lock(&po->pg_vec_lock);
3866         if (closing || atomic_read(&po->mapped) == 0) {
3867                 err = 0;
3868                 spin_lock_bh(&rb_queue->lock);
3869                 swap(rb->pg_vec, pg_vec);
3870                 rb->frame_max = (req->tp_frame_nr - 1);
3871                 rb->head = 0;
3872                 rb->frame_size = req->tp_frame_size;
3873                 spin_unlock_bh(&rb_queue->lock);
3874
3875                 swap(rb->pg_vec_order, order);
3876                 swap(rb->pg_vec_len, req->tp_block_nr);
3877
3878                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3879                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3880                                                 tpacket_rcv : packet_rcv;
3881                 skb_queue_purge(rb_queue);
3882                 if (atomic_read(&po->mapped))
3883                         pr_err("packet_mmap: vma is busy: %d\n",
3884                                atomic_read(&po->mapped));
3885         }
3886         mutex_unlock(&po->pg_vec_lock);
3887
3888         spin_lock(&po->bind_lock);
3889         if (was_running) {
3890                 po->num = num;
3891                 register_prot_hook(sk);
3892         }
3893         spin_unlock(&po->bind_lock);
3894         if (closing && (po->tp_version > TPACKET_V2)) {
3895                 /* Because we don't support block-based V3 on tx-ring */
3896                 if (!tx_ring)
3897                         prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3898         }
3899         release_sock(sk);
3900
3901         if (pg_vec)
3902                 free_pg_vec(pg_vec, order, req->tp_block_nr);
3903 out:
3904         return err;
3905 }
3906
3907 static int packet_mmap(struct file *file, struct socket *sock,
3908                 struct vm_area_struct *vma)
3909 {
3910         struct sock *sk = sock->sk;
3911         struct packet_sock *po = pkt_sk(sk);
3912         unsigned long size, expected_size;
3913         struct packet_ring_buffer *rb;
3914         unsigned long start;
3915         int err = -EINVAL;
3916         int i;
3917
3918         if (vma->vm_pgoff)
3919                 return -EINVAL;
3920
3921         mutex_lock(&po->pg_vec_lock);
3922
3923         expected_size = 0;
3924         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3925                 if (rb->pg_vec) {
3926                         expected_size += rb->pg_vec_len
3927                                                 * rb->pg_vec_pages
3928                                                 * PAGE_SIZE;
3929                 }
3930         }
3931
3932         if (expected_size == 0)
3933                 goto out;
3934
3935         size = vma->vm_end - vma->vm_start;
3936         if (size != expected_size)
3937                 goto out;
3938
3939         start = vma->vm_start;
3940         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3941                 if (rb->pg_vec == NULL)
3942                         continue;
3943
3944                 for (i = 0; i < rb->pg_vec_len; i++) {
3945                         struct page *page;
3946                         void *kaddr = rb->pg_vec[i].buffer;
3947                         int pg_num;
3948
3949                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3950                                 page = pgv_to_page(kaddr);
3951                                 err = vm_insert_page(vma, start, page);
3952                                 if (unlikely(err))
3953                                         goto out;
3954                                 start += PAGE_SIZE;
3955                                 kaddr += PAGE_SIZE;
3956                         }
3957                 }
3958         }
3959
3960         atomic_inc(&po->mapped);
3961         vma->vm_ops = &packet_mmap_ops;
3962         err = 0;
3963
3964 out:
3965         mutex_unlock(&po->pg_vec_lock);
3966         return err;
3967 }
3968
3969 static const struct proto_ops packet_ops_spkt = {
3970         .family =       PF_PACKET,
3971         .owner =        THIS_MODULE,
3972         .release =      packet_release,
3973         .bind =         packet_bind_spkt,
3974         .connect =      sock_no_connect,
3975         .socketpair =   sock_no_socketpair,
3976         .accept =       sock_no_accept,
3977         .getname =      packet_getname_spkt,
3978         .poll =         datagram_poll,
3979         .ioctl =        packet_ioctl,
3980         .listen =       sock_no_listen,
3981         .shutdown =     sock_no_shutdown,
3982         .setsockopt =   sock_no_setsockopt,
3983         .getsockopt =   sock_no_getsockopt,
3984         .sendmsg =      packet_sendmsg_spkt,
3985         .recvmsg =      packet_recvmsg,
3986         .mmap =         sock_no_mmap,
3987         .sendpage =     sock_no_sendpage,
3988 };
3989
3990 static const struct proto_ops packet_ops = {
3991         .family =       PF_PACKET,
3992         .owner =        THIS_MODULE,
3993         .release =      packet_release,
3994         .bind =         packet_bind,
3995         .connect =      sock_no_connect,
3996         .socketpair =   sock_no_socketpair,
3997         .accept =       sock_no_accept,
3998         .getname =      packet_getname,
3999         .poll =         packet_poll,
4000         .ioctl =        packet_ioctl,
4001         .listen =       sock_no_listen,
4002         .shutdown =     sock_no_shutdown,
4003         .setsockopt =   packet_setsockopt,
4004         .getsockopt =   packet_getsockopt,
4005         .sendmsg =      packet_sendmsg,
4006         .recvmsg =      packet_recvmsg,
4007         .mmap =         packet_mmap,
4008         .sendpage =     sock_no_sendpage,
4009 };
4010
4011 static const struct net_proto_family packet_family_ops = {
4012         .family =       PF_PACKET,
4013         .create =       packet_create,
4014         .owner  =       THIS_MODULE,
4015 };
4016
4017 static struct notifier_block packet_netdev_notifier = {
4018         .notifier_call =        packet_notifier,
4019 };
4020
4021 #ifdef CONFIG_PROC_FS
4022
4023 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4024         __acquires(RCU)
4025 {
4026         struct net *net = seq_file_net(seq);
4027
4028         rcu_read_lock();
4029         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4030 }
4031
4032 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4033 {
4034         struct net *net = seq_file_net(seq);
4035         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4036 }
4037
4038 static void packet_seq_stop(struct seq_file *seq, void *v)
4039         __releases(RCU)
4040 {
4041         rcu_read_unlock();
4042 }
4043
4044 static int packet_seq_show(struct seq_file *seq, void *v)
4045 {
4046         if (v == SEQ_START_TOKEN)
4047                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4048         else {
4049                 struct sock *s = sk_entry(v);
4050                 const struct packet_sock *po = pkt_sk(s);
4051
4052                 seq_printf(seq,
4053                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4054                            s,
4055                            atomic_read(&s->sk_refcnt),
4056                            s->sk_type,
4057                            ntohs(po->num),
4058                            po->ifindex,
4059                            po->running,
4060                            atomic_read(&s->sk_rmem_alloc),
4061                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4062                            sock_i_ino(s));
4063         }
4064
4065         return 0;
4066 }
4067
4068 static const struct seq_operations packet_seq_ops = {
4069         .start  = packet_seq_start,
4070         .next   = packet_seq_next,
4071         .stop   = packet_seq_stop,
4072         .show   = packet_seq_show,
4073 };
4074
4075 static int packet_seq_open(struct inode *inode, struct file *file)
4076 {
4077         return seq_open_net(inode, file, &packet_seq_ops,
4078                             sizeof(struct seq_net_private));
4079 }
4080
4081 static const struct file_operations packet_seq_fops = {
4082         .owner          = THIS_MODULE,
4083         .open           = packet_seq_open,
4084         .read           = seq_read,
4085         .llseek         = seq_lseek,
4086         .release        = seq_release_net,
4087 };
4088
4089 #endif
4090
4091 static int __net_init packet_net_init(struct net *net)
4092 {
4093         mutex_init(&net->packet.sklist_lock);
4094         INIT_HLIST_HEAD(&net->packet.sklist);
4095
4096         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4097                 return -ENOMEM;
4098
4099         return 0;
4100 }
4101
4102 static void __net_exit packet_net_exit(struct net *net)
4103 {
4104         remove_proc_entry("packet", net->proc_net);
4105 }
4106
4107 static struct pernet_operations packet_net_ops = {
4108         .init = packet_net_init,
4109         .exit = packet_net_exit,
4110 };
4111
4112
4113 static void __exit packet_exit(void)
4114 {
4115         unregister_netdevice_notifier(&packet_netdev_notifier);
4116         unregister_pernet_subsys(&packet_net_ops);
4117         sock_unregister(PF_PACKET);
4118         proto_unregister(&packet_proto);
4119 }
4120
4121 static int __init packet_init(void)
4122 {
4123         int rc = proto_register(&packet_proto, 0);
4124
4125         if (rc != 0)
4126                 goto out;
4127
4128         sock_register(&packet_family_ops);
4129         register_pernet_subsys(&packet_net_ops);
4130         register_netdevice_notifier(&packet_netdev_notifier);
4131 out:
4132         return rc;
4133 }
4134
4135 module_init(packet_init);
4136 module_exit(packet_exit);
4137 MODULE_LICENSE("GPL");
4138 MODULE_ALIAS_NETPROTO(PF_PACKET);