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Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
[linux-2.6.git] / net / packet / af_packet.c
blob4b66c752eae5d99b2bfe5fa7832a1301d20519ef
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
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 /* register_prot_hook must be invoked with the po->bind_lock held,
241 * or from a context in which asynchronous accesses to the packet
242 * socket is not possible (packet_create()).
243 */
244 static void register_prot_hook(struct sock *sk)
245 {
246 struct packet_sock *po = pkt_sk(sk);
247 if (!po->running) {
248 if (po->fanout)
249 __fanout_link(sk, po);
250 else
251 dev_add_pack(&po->prot_hook);
252 sock_hold(sk);
253 po->running = 1;
254 }
255 }
256
257 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
258 * held. If the sync parameter is true, we will temporarily drop
259 * the po->bind_lock and do a synchronize_net to make sure no
260 * asynchronous packet processing paths still refer to the elements
261 * of po->prot_hook. If the sync parameter is false, it is the
262 * callers responsibility to take care of this.
263 */
264 static void __unregister_prot_hook(struct sock *sk, bool sync)
265 {
266 struct packet_sock *po = pkt_sk(sk);
267
268 po->running = 0;
269 if (po->fanout)
270 __fanout_unlink(sk, po);
271 else
272 __dev_remove_pack(&po->prot_hook);
273 __sock_put(sk);
274
275 if (sync) {
276 spin_unlock(&po->bind_lock);
277 synchronize_net();
278 spin_lock(&po->bind_lock);
279 }
280 }
281
282 static void unregister_prot_hook(struct sock *sk, bool sync)
283 {
284 struct packet_sock *po = pkt_sk(sk);
285
286 if (po->running)
287 __unregister_prot_hook(sk, sync);
288 }
289
290 static inline __pure struct page *pgv_to_page(void *addr)
291 {
292 if (is_vmalloc_addr(addr))
293 return vmalloc_to_page(addr);
294 return virt_to_page(addr);
295 }
296
297 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
298 {
299 union tpacket_uhdr h;
300
301 h.raw = frame;
302 switch (po->tp_version) {
303 case TPACKET_V1:
304 h.h1->tp_status = status;
305 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
306 break;
307 case TPACKET_V2:
308 h.h2->tp_status = status;
309 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
310 break;
311 case TPACKET_V3:
312 default:
313 WARN(1, "TPACKET version not supported.\n");
314 BUG();
315 }
316
317 smp_wmb();
318 }
319
320 static int __packet_get_status(struct packet_sock *po, void *frame)
321 {
322 union tpacket_uhdr h;
323
324 smp_rmb();
325
326 h.raw = frame;
327 switch (po->tp_version) {
328 case TPACKET_V1:
329 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
330 return h.h1->tp_status;
331 case TPACKET_V2:
332 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
333 return h.h2->tp_status;
334 case TPACKET_V3:
335 default:
336 WARN(1, "TPACKET version not supported.\n");
337 BUG();
338 return 0;
339 }
340 }
341
342 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
343 unsigned int flags)
344 {
345 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
346
347 if (shhwtstamps) {
348 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
349 ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
350 return TP_STATUS_TS_SYS_HARDWARE;
351 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
352 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
353 return TP_STATUS_TS_RAW_HARDWARE;
354 }
355
356 if (ktime_to_timespec_cond(skb->tstamp, ts))
357 return TP_STATUS_TS_SOFTWARE;
358
359 return 0;
360 }
361
362 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
363 struct sk_buff *skb)
364 {
365 union tpacket_uhdr h;
366 struct timespec ts;
367 __u32 ts_status;
368
369 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
370 return 0;
371
372 h.raw = frame;
373 switch (po->tp_version) {
374 case TPACKET_V1:
375 h.h1->tp_sec = ts.tv_sec;
376 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
377 break;
378 case TPACKET_V2:
379 h.h2->tp_sec = ts.tv_sec;
380 h.h2->tp_nsec = ts.tv_nsec;
381 break;
382 case TPACKET_V3:
383 default:
384 WARN(1, "TPACKET version not supported.\n");
385 BUG();
386 }
387
388 /* one flush is safe, as both fields always lie on the same cacheline */
389 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
390 smp_wmb();
391
392 return ts_status;
393 }
394
395 static void *packet_lookup_frame(struct packet_sock *po,
396 struct packet_ring_buffer *rb,
397 unsigned int position,
398 int status)
399 {
400 unsigned int pg_vec_pos, frame_offset;
401 union tpacket_uhdr h;
402
403 pg_vec_pos = position / rb->frames_per_block;
404 frame_offset = position % rb->frames_per_block;
405
406 h.raw = rb->pg_vec[pg_vec_pos].buffer +
407 (frame_offset * rb->frame_size);
408
409 if (status != __packet_get_status(po, h.raw))
410 return NULL;
411
412 return h.raw;
413 }
414
415 static void *packet_current_frame(struct packet_sock *po,
416 struct packet_ring_buffer *rb,
417 int status)
418 {
419 return packet_lookup_frame(po, rb, rb->head, status);
420 }
421
422 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
423 {
424 del_timer_sync(&pkc->retire_blk_timer);
425 }
426
427 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
428 int tx_ring,
429 struct sk_buff_head *rb_queue)
430 {
431 struct tpacket_kbdq_core *pkc;
432
433 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
434
435 spin_lock(&rb_queue->lock);
436 pkc->delete_blk_timer = 1;
437 spin_unlock(&rb_queue->lock);
438
439 prb_del_retire_blk_timer(pkc);
440 }
441
442 static void prb_init_blk_timer(struct packet_sock *po,
443 struct tpacket_kbdq_core *pkc,
444 void (*func) (unsigned long))
445 {
446 init_timer(&pkc->retire_blk_timer);
447 pkc->retire_blk_timer.data = (long)po;
448 pkc->retire_blk_timer.function = func;
449 pkc->retire_blk_timer.expires = jiffies;
450 }
451
452 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
453 {
454 struct tpacket_kbdq_core *pkc;
455
456 if (tx_ring)
457 BUG();
458
459 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
460 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
461 }
462
463 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
464 int blk_size_in_bytes)
465 {
466 struct net_device *dev;
467 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
468 struct ethtool_cmd ecmd;
469 int err;
470 u32 speed;
471
472 rtnl_lock();
473 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
474 if (unlikely(!dev)) {
475 rtnl_unlock();
476 return DEFAULT_PRB_RETIRE_TOV;
477 }
478 err = __ethtool_get_settings(dev, &ecmd);
479 speed = ethtool_cmd_speed(&ecmd);
480 rtnl_unlock();
481 if (!err) {
482 /*
483 * If the link speed is so slow you don't really
484 * need to worry about perf anyways
485 */
486 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
487 return DEFAULT_PRB_RETIRE_TOV;
488 } else {
489 msec = 1;
490 div = speed / 1000;
491 }
492 }
493
494 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
495
496 if (div)
497 mbits /= div;
498
499 tmo = mbits * msec;
500
501 if (div)
502 return tmo+1;
503 return tmo;
504 }
505
506 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
507 union tpacket_req_u *req_u)
508 {
509 p1->feature_req_word = req_u->req3.tp_feature_req_word;
510 }
511
512 static void init_prb_bdqc(struct packet_sock *po,
513 struct packet_ring_buffer *rb,
514 struct pgv *pg_vec,
515 union tpacket_req_u *req_u, int tx_ring)
516 {
517 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
518 struct tpacket_block_desc *pbd;
519
520 memset(p1, 0x0, sizeof(*p1));
521
522 p1->knxt_seq_num = 1;
523 p1->pkbdq = pg_vec;
524 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
525 p1->pkblk_start = pg_vec[0].buffer;
526 p1->kblk_size = req_u->req3.tp_block_size;
527 p1->knum_blocks = req_u->req3.tp_block_nr;
528 p1->hdrlen = po->tp_hdrlen;
529 p1->version = po->tp_version;
530 p1->last_kactive_blk_num = 0;
531 po->stats.stats3.tp_freeze_q_cnt = 0;
532 if (req_u->req3.tp_retire_blk_tov)
533 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
534 else
535 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
536 req_u->req3.tp_block_size);
537 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
538 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
539
540 prb_init_ft_ops(p1, req_u);
541 prb_setup_retire_blk_timer(po, tx_ring);
542 prb_open_block(p1, pbd);
543 }
544
545 /* Do NOT update the last_blk_num first.
546 * Assumes sk_buff_head lock is held.
547 */
548 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
549 {
550 mod_timer(&pkc->retire_blk_timer,
551 jiffies + pkc->tov_in_jiffies);
552 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
553 }
554
555 /*
556 * Timer logic:
557 * 1) We refresh the timer only when we open a block.
558 * By doing this we don't waste cycles refreshing the timer
559 * on packet-by-packet basis.
560 *
561 * With a 1MB block-size, on a 1Gbps line, it will take
562 * i) ~8 ms to fill a block + ii) memcpy etc.
563 * In this cut we are not accounting for the memcpy time.
564 *
565 * So, if the user sets the 'tmo' to 10ms then the timer
566 * will never fire while the block is still getting filled
567 * (which is what we want). However, the user could choose
568 * to close a block early and that's fine.
569 *
570 * But when the timer does fire, we check whether or not to refresh it.
571 * Since the tmo granularity is in msecs, it is not too expensive
572 * to refresh the timer, lets say every '8' msecs.
573 * Either the user can set the 'tmo' or we can derive it based on
574 * a) line-speed and b) block-size.
575 * prb_calc_retire_blk_tmo() calculates the tmo.
576 *
577 */
578 static void prb_retire_rx_blk_timer_expired(unsigned long data)
579 {
580 struct packet_sock *po = (struct packet_sock *)data;
581 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
582 unsigned int frozen;
583 struct tpacket_block_desc *pbd;
584
585 spin_lock(&po->sk.sk_receive_queue.lock);
586
587 frozen = prb_queue_frozen(pkc);
588 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
589
590 if (unlikely(pkc->delete_blk_timer))
591 goto out;
592
593 /* We only need to plug the race when the block is partially filled.
594 * tpacket_rcv:
595 * lock(); increment BLOCK_NUM_PKTS; unlock()
596 * copy_bits() is in progress ...
597 * timer fires on other cpu:
598 * we can't retire the current block because copy_bits
599 * is in progress.
600 *
601 */
602 if (BLOCK_NUM_PKTS(pbd)) {
603 while (atomic_read(&pkc->blk_fill_in_prog)) {
604 /* Waiting for skb_copy_bits to finish... */
605 cpu_relax();
606 }
607 }
608
609 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
610 if (!frozen) {
611 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
612 if (!prb_dispatch_next_block(pkc, po))
613 goto refresh_timer;
614 else
615 goto out;
616 } else {
617 /* Case 1. Queue was frozen because user-space was
618 * lagging behind.
619 */
620 if (prb_curr_blk_in_use(pkc, pbd)) {
621 /*
622 * Ok, user-space is still behind.
623 * So just refresh the timer.
624 */
625 goto refresh_timer;
626 } else {
627 /* Case 2. queue was frozen,user-space caught up,
628 * now the link went idle && the timer fired.
629 * We don't have a block to close.So we open this
630 * block and restart the timer.
631 * opening a block thaws the queue,restarts timer
632 * Thawing/timer-refresh is a side effect.
633 */
634 prb_open_block(pkc, pbd);
635 goto out;
636 }
637 }
638 }
639
640 refresh_timer:
641 _prb_refresh_rx_retire_blk_timer(pkc);
642
643 out:
644 spin_unlock(&po->sk.sk_receive_queue.lock);
645 }
646
647 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
648 struct tpacket_block_desc *pbd1, __u32 status)
649 {
650 /* Flush everything minus the block header */
651
652 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
653 u8 *start, *end;
654
655 start = (u8 *)pbd1;
656
657 /* Skip the block header(we know header WILL fit in 4K) */
658 start += PAGE_SIZE;
659
660 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
661 for (; start < end; start += PAGE_SIZE)
662 flush_dcache_page(pgv_to_page(start));
663
664 smp_wmb();
665 #endif
666
667 /* Now update the block status. */
668
669 BLOCK_STATUS(pbd1) = status;
670
671 /* Flush the block header */
672
673 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
674 start = (u8 *)pbd1;
675 flush_dcache_page(pgv_to_page(start));
676
677 smp_wmb();
678 #endif
679 }
680
681 /*
682 * Side effect:
683 *
684 * 1) flush the block
685 * 2) Increment active_blk_num
686 *
687 * Note:We DONT refresh the timer on purpose.
688 * Because almost always the next block will be opened.
689 */
690 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
691 struct tpacket_block_desc *pbd1,
692 struct packet_sock *po, unsigned int stat)
693 {
694 __u32 status = TP_STATUS_USER | stat;
695
696 struct tpacket3_hdr *last_pkt;
697 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
698
699 if (po->stats.stats3.tp_drops)
700 status |= TP_STATUS_LOSING;
701
702 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
703 last_pkt->tp_next_offset = 0;
704
705 /* Get the ts of the last pkt */
706 if (BLOCK_NUM_PKTS(pbd1)) {
707 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
708 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
709 } else {
710 /* Ok, we tmo'd - so get the current time */
711 struct timespec ts;
712 getnstimeofday(&ts);
713 h1->ts_last_pkt.ts_sec = ts.tv_sec;
714 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
715 }
716
717 smp_wmb();
718
719 /* Flush the block */
720 prb_flush_block(pkc1, pbd1, status);
721
722 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
723 }
724
725 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
726 {
727 pkc->reset_pending_on_curr_blk = 0;
728 }
729
730 /*
731 * Side effect of opening a block:
732 *
733 * 1) prb_queue is thawed.
734 * 2) retire_blk_timer is refreshed.
735 *
736 */
737 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
738 struct tpacket_block_desc *pbd1)
739 {
740 struct timespec ts;
741 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
742
743 smp_rmb();
744
745 /* We could have just memset this but we will lose the
746 * flexibility of making the priv area sticky
747 */
748
749 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
750 BLOCK_NUM_PKTS(pbd1) = 0;
751 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
752
753 getnstimeofday(&ts);
754
755 h1->ts_first_pkt.ts_sec = ts.tv_sec;
756 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
757
758 pkc1->pkblk_start = (char *)pbd1;
759 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
760
761 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
762 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
763
764 pbd1->version = pkc1->version;
765 pkc1->prev = pkc1->nxt_offset;
766 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
767
768 prb_thaw_queue(pkc1);
769 _prb_refresh_rx_retire_blk_timer(pkc1);
770
771 smp_wmb();
772 }
773
774 /*
775 * Queue freeze logic:
776 * 1) Assume tp_block_nr = 8 blocks.
777 * 2) At time 't0', user opens Rx ring.
778 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
779 * 4) user-space is either sleeping or processing block '0'.
780 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
781 * it will close block-7,loop around and try to fill block '0'.
782 * call-flow:
783 * __packet_lookup_frame_in_block
784 * prb_retire_current_block()
785 * prb_dispatch_next_block()
786 * |->(BLOCK_STATUS == USER) evaluates to true
787 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
788 * 6) Now there are two cases:
789 * 6.1) Link goes idle right after the queue is frozen.
790 * But remember, the last open_block() refreshed the timer.
791 * When this timer expires,it will refresh itself so that we can
792 * re-open block-0 in near future.
793 * 6.2) Link is busy and keeps on receiving packets. This is a simple
794 * case and __packet_lookup_frame_in_block will check if block-0
795 * is free and can now be re-used.
796 */
797 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
798 struct packet_sock *po)
799 {
800 pkc->reset_pending_on_curr_blk = 1;
801 po->stats.stats3.tp_freeze_q_cnt++;
802 }
803
804 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
805
806 /*
807 * If the next block is free then we will dispatch it
808 * and return a good offset.
809 * Else, we will freeze the queue.
810 * So, caller must check the return value.
811 */
812 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
813 struct packet_sock *po)
814 {
815 struct tpacket_block_desc *pbd;
816
817 smp_rmb();
818
819 /* 1. Get current block num */
820 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
821
822 /* 2. If this block is currently in_use then freeze the queue */
823 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
824 prb_freeze_queue(pkc, po);
825 return NULL;
826 }
827
828 /*
829 * 3.
830 * open this block and return the offset where the first packet
831 * needs to get stored.
832 */
833 prb_open_block(pkc, pbd);
834 return (void *)pkc->nxt_offset;
835 }
836
837 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
838 struct packet_sock *po, unsigned int status)
839 {
840 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
841
842 /* retire/close the current block */
843 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
844 /*
845 * Plug the case where copy_bits() is in progress on
846 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
847 * have space to copy the pkt in the current block and
848 * called prb_retire_current_block()
849 *
850 * We don't need to worry about the TMO case because
851 * the timer-handler already handled this case.
852 */
853 if (!(status & TP_STATUS_BLK_TMO)) {
854 while (atomic_read(&pkc->blk_fill_in_prog)) {
855 /* Waiting for skb_copy_bits to finish... */
856 cpu_relax();
857 }
858 }
859 prb_close_block(pkc, pbd, po, status);
860 return;
861 }
862 }
863
864 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
865 struct tpacket_block_desc *pbd)
866 {
867 return TP_STATUS_USER & BLOCK_STATUS(pbd);
868 }
869
870 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
871 {
872 return pkc->reset_pending_on_curr_blk;
873 }
874
875 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
876 {
877 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
878 atomic_dec(&pkc->blk_fill_in_prog);
879 }
880
881 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
882 struct tpacket3_hdr *ppd)
883 {
884 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
885 }
886
887 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
888 struct tpacket3_hdr *ppd)
889 {
890 ppd->hv1.tp_rxhash = 0;
891 }
892
893 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
894 struct tpacket3_hdr *ppd)
895 {
896 if (vlan_tx_tag_present(pkc->skb)) {
897 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
898 ppd->tp_status = TP_STATUS_VLAN_VALID;
899 } else {
900 ppd->hv1.tp_vlan_tci = 0;
901 ppd->tp_status = TP_STATUS_AVAILABLE;
902 }
903 }
904
905 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
906 struct tpacket3_hdr *ppd)
907 {
908 prb_fill_vlan_info(pkc, ppd);
909
910 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
911 prb_fill_rxhash(pkc, ppd);
912 else
913 prb_clear_rxhash(pkc, ppd);
914 }
915
916 static void prb_fill_curr_block(char *curr,
917 struct tpacket_kbdq_core *pkc,
918 struct tpacket_block_desc *pbd,
919 unsigned int len)
920 {
921 struct tpacket3_hdr *ppd;
922
923 ppd = (struct tpacket3_hdr *)curr;
924 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
925 pkc->prev = curr;
926 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
927 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
928 BLOCK_NUM_PKTS(pbd) += 1;
929 atomic_inc(&pkc->blk_fill_in_prog);
930 prb_run_all_ft_ops(pkc, ppd);
931 }
932
933 /* Assumes caller has the sk->rx_queue.lock */
934 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
935 struct sk_buff *skb,
936 int status,
937 unsigned int len
938 )
939 {
940 struct tpacket_kbdq_core *pkc;
941 struct tpacket_block_desc *pbd;
942 char *curr, *end;
943
944 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
945 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
946
947 /* Queue is frozen when user space is lagging behind */
948 if (prb_queue_frozen(pkc)) {
949 /*
950 * Check if that last block which caused the queue to freeze,
951 * is still in_use by user-space.
952 */
953 if (prb_curr_blk_in_use(pkc, pbd)) {
954 /* Can't record this packet */
955 return NULL;
956 } else {
957 /*
958 * Ok, the block was released by user-space.
959 * Now let's open that block.
960 * opening a block also thaws the queue.
961 * Thawing is a side effect.
962 */
963 prb_open_block(pkc, pbd);
964 }
965 }
966
967 smp_mb();
968 curr = pkc->nxt_offset;
969 pkc->skb = skb;
970 end = (char *)pbd + pkc->kblk_size;
971
972 /* first try the current block */
973 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
974 prb_fill_curr_block(curr, pkc, pbd, len);
975 return (void *)curr;
976 }
977
978 /* Ok, close the current block */
979 prb_retire_current_block(pkc, po, 0);
980
981 /* Now, try to dispatch the next block */
982 curr = (char *)prb_dispatch_next_block(pkc, po);
983 if (curr) {
984 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
985 prb_fill_curr_block(curr, pkc, pbd, len);
986 return (void *)curr;
987 }
988
989 /*
990 * No free blocks are available.user_space hasn't caught up yet.
991 * Queue was just frozen and now this packet will get dropped.
992 */
993 return NULL;
994 }
995
996 static void *packet_current_rx_frame(struct packet_sock *po,
997 struct sk_buff *skb,
998 int status, unsigned int len)
999 {
1000 char *curr = NULL;
1001 switch (po->tp_version) {
1002 case TPACKET_V1:
1003 case TPACKET_V2:
1004 curr = packet_lookup_frame(po, &po->rx_ring,
1005 po->rx_ring.head, status);
1006 return curr;
1007 case TPACKET_V3:
1008 return __packet_lookup_frame_in_block(po, skb, status, len);
1009 default:
1010 WARN(1, "TPACKET version not supported\n");
1011 BUG();
1012 return NULL;
1013 }
1014 }
1015
1016 static void *prb_lookup_block(struct packet_sock *po,
1017 struct packet_ring_buffer *rb,
1018 unsigned int idx,
1019 int status)
1020 {
1021 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1022 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1023
1024 if (status != BLOCK_STATUS(pbd))
1025 return NULL;
1026 return pbd;
1027 }
1028
1029 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1030 {
1031 unsigned int prev;
1032 if (rb->prb_bdqc.kactive_blk_num)
1033 prev = rb->prb_bdqc.kactive_blk_num-1;
1034 else
1035 prev = rb->prb_bdqc.knum_blocks-1;
1036 return prev;
1037 }
1038
1039 /* Assumes caller has held the rx_queue.lock */
1040 static void *__prb_previous_block(struct packet_sock *po,
1041 struct packet_ring_buffer *rb,
1042 int status)
1043 {
1044 unsigned int previous = prb_previous_blk_num(rb);
1045 return prb_lookup_block(po, rb, previous, status);
1046 }
1047
1048 static void *packet_previous_rx_frame(struct packet_sock *po,
1049 struct packet_ring_buffer *rb,
1050 int status)
1051 {
1052 if (po->tp_version <= TPACKET_V2)
1053 return packet_previous_frame(po, rb, status);
1054
1055 return __prb_previous_block(po, rb, status);
1056 }
1057
1058 static void packet_increment_rx_head(struct packet_sock *po,
1059 struct packet_ring_buffer *rb)
1060 {
1061 switch (po->tp_version) {
1062 case TPACKET_V1:
1063 case TPACKET_V2:
1064 return packet_increment_head(rb);
1065 case TPACKET_V3:
1066 default:
1067 WARN(1, "TPACKET version not supported.\n");
1068 BUG();
1069 return;
1070 }
1071 }
1072
1073 static void *packet_previous_frame(struct packet_sock *po,
1074 struct packet_ring_buffer *rb,
1075 int status)
1076 {
1077 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1078 return packet_lookup_frame(po, rb, previous, status);
1079 }
1080
1081 static void packet_increment_head(struct packet_ring_buffer *buff)
1082 {
1083 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1084 }
1085
1086 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1087 {
1088 struct sock *sk = &po->sk;
1089 bool has_room;
1090
1091 if (po->prot_hook.func != tpacket_rcv)
1092 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
1093 <= sk->sk_rcvbuf;
1094
1095 spin_lock(&sk->sk_receive_queue.lock);
1096 if (po->tp_version == TPACKET_V3)
1097 has_room = prb_lookup_block(po, &po->rx_ring,
1098 po->rx_ring.prb_bdqc.kactive_blk_num,
1099 TP_STATUS_KERNEL);
1100 else
1101 has_room = packet_lookup_frame(po, &po->rx_ring,
1102 po->rx_ring.head,
1103 TP_STATUS_KERNEL);
1104 spin_unlock(&sk->sk_receive_queue.lock);
1105
1106 return has_room;
1107 }
1108
1109 static void packet_sock_destruct(struct sock *sk)
1110 {
1111 skb_queue_purge(&sk->sk_error_queue);
1112
1113 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1114 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1115
1116 if (!sock_flag(sk, SOCK_DEAD)) {
1117 pr_err("Attempt to release alive packet socket: %p\n", sk);
1118 return;
1119 }
1120
1121 sk_refcnt_debug_dec(sk);
1122 }
1123
1124 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1125 {
1126 int x = atomic_read(&f->rr_cur) + 1;
1127
1128 if (x >= num)
1129 x = 0;
1130
1131 return x;
1132 }
1133
1134 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1135 struct sk_buff *skb,
1136 unsigned int num)
1137 {
1138 return (((u64)skb->rxhash) * num) >> 32;
1139 }
1140
1141 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1142 struct sk_buff *skb,
1143 unsigned int num)
1144 {
1145 int cur, old;
1146
1147 cur = atomic_read(&f->rr_cur);
1148 while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1149 fanout_rr_next(f, num))) != cur)
1150 cur = old;
1151 return cur;
1152 }
1153
1154 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1155 struct sk_buff *skb,
1156 unsigned int num)
1157 {
1158 return smp_processor_id() % num;
1159 }
1160
1161 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1162 struct sk_buff *skb,
1163 unsigned int idx, unsigned int skip,
1164 unsigned int num)
1165 {
1166 unsigned int i, j;
1167
1168 i = j = min_t(int, f->next[idx], num - 1);
1169 do {
1170 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1171 if (i != j)
1172 f->next[idx] = i;
1173 return i;
1174 }
1175 if (++i == num)
1176 i = 0;
1177 } while (i != j);
1178
1179 return idx;
1180 }
1181
1182 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1183 {
1184 return f->flags & (flag >> 8);
1185 }
1186
1187 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1188 struct packet_type *pt, struct net_device *orig_dev)
1189 {
1190 struct packet_fanout *f = pt->af_packet_priv;
1191 unsigned int num = f->num_members;
1192 struct packet_sock *po;
1193 unsigned int idx;
1194
1195 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1196 !num) {
1197 kfree_skb(skb);
1198 return 0;
1199 }
1200
1201 switch (f->type) {
1202 case PACKET_FANOUT_HASH:
1203 default:
1204 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1205 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1206 if (!skb)
1207 return 0;
1208 }
1209 skb_get_rxhash(skb);
1210 idx = fanout_demux_hash(f, skb, num);
1211 break;
1212 case PACKET_FANOUT_LB:
1213 idx = fanout_demux_lb(f, skb, num);
1214 break;
1215 case PACKET_FANOUT_CPU:
1216 idx = fanout_demux_cpu(f, skb, num);
1217 break;
1218 case PACKET_FANOUT_ROLLOVER:
1219 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1220 break;
1221 }
1222
1223 po = pkt_sk(f->arr[idx]);
1224 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1225 unlikely(!packet_rcv_has_room(po, skb))) {
1226 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1227 po = pkt_sk(f->arr[idx]);
1228 }
1229
1230 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1231 }
1232
1233 DEFINE_MUTEX(fanout_mutex);
1234 EXPORT_SYMBOL_GPL(fanout_mutex);
1235 static LIST_HEAD(fanout_list);
1236
1237 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1238 {
1239 struct packet_fanout *f = po->fanout;
1240
1241 spin_lock(&f->lock);
1242 f->arr[f->num_members] = sk;
1243 smp_wmb();
1244 f->num_members++;
1245 spin_unlock(&f->lock);
1246 }
1247
1248 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1249 {
1250 struct packet_fanout *f = po->fanout;
1251 int i;
1252
1253 spin_lock(&f->lock);
1254 for (i = 0; i < f->num_members; i++) {
1255 if (f->arr[i] == sk)
1256 break;
1257 }
1258 BUG_ON(i >= f->num_members);
1259 f->arr[i] = f->arr[f->num_members - 1];
1260 f->num_members--;
1261 spin_unlock(&f->lock);
1262 }
1263
1264 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1265 {
1266 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1267 return true;
1268
1269 return false;
1270 }
1271
1272 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1273 {
1274 struct packet_sock *po = pkt_sk(sk);
1275 struct packet_fanout *f, *match;
1276 u8 type = type_flags & 0xff;
1277 u8 flags = type_flags >> 8;
1278 int err;
1279
1280 switch (type) {
1281 case PACKET_FANOUT_ROLLOVER:
1282 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1283 return -EINVAL;
1284 case PACKET_FANOUT_HASH:
1285 case PACKET_FANOUT_LB:
1286 case PACKET_FANOUT_CPU:
1287 break;
1288 default:
1289 return -EINVAL;
1290 }
1291
1292 if (!po->running)
1293 return -EINVAL;
1294
1295 if (po->fanout)
1296 return -EALREADY;
1297
1298 mutex_lock(&fanout_mutex);
1299 match = NULL;
1300 list_for_each_entry(f, &fanout_list, list) {
1301 if (f->id == id &&
1302 read_pnet(&f->net) == sock_net(sk)) {
1303 match = f;
1304 break;
1305 }
1306 }
1307 err = -EINVAL;
1308 if (match && match->flags != flags)
1309 goto out;
1310 if (!match) {
1311 err = -ENOMEM;
1312 match = kzalloc(sizeof(*match), GFP_KERNEL);
1313 if (!match)
1314 goto out;
1315 write_pnet(&match->net, sock_net(sk));
1316 match->id = id;
1317 match->type = type;
1318 match->flags = flags;
1319 atomic_set(&match->rr_cur, 0);
1320 INIT_LIST_HEAD(&match->list);
1321 spin_lock_init(&match->lock);
1322 atomic_set(&match->sk_ref, 0);
1323 match->prot_hook.type = po->prot_hook.type;
1324 match->prot_hook.dev = po->prot_hook.dev;
1325 match->prot_hook.func = packet_rcv_fanout;
1326 match->prot_hook.af_packet_priv = match;
1327 match->prot_hook.id_match = match_fanout_group;
1328 dev_add_pack(&match->prot_hook);
1329 list_add(&match->list, &fanout_list);
1330 }
1331 err = -EINVAL;
1332 if (match->type == type &&
1333 match->prot_hook.type == po->prot_hook.type &&
1334 match->prot_hook.dev == po->prot_hook.dev) {
1335 err = -ENOSPC;
1336 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1337 __dev_remove_pack(&po->prot_hook);
1338 po->fanout = match;
1339 atomic_inc(&match->sk_ref);
1340 __fanout_link(sk, po);
1341 err = 0;
1342 }
1343 }
1344 out:
1345 mutex_unlock(&fanout_mutex);
1346 return err;
1347 }
1348
1349 static void fanout_release(struct sock *sk)
1350 {
1351 struct packet_sock *po = pkt_sk(sk);
1352 struct packet_fanout *f;
1353
1354 f = po->fanout;
1355 if (!f)
1356 return;
1357
1358 mutex_lock(&fanout_mutex);
1359 po->fanout = NULL;
1360
1361 if (atomic_dec_and_test(&f->sk_ref)) {
1362 list_del(&f->list);
1363 dev_remove_pack(&f->prot_hook);
1364 kfree(f);
1365 }
1366 mutex_unlock(&fanout_mutex);
1367 }
1368
1369 static const struct proto_ops packet_ops;
1370
1371 static const struct proto_ops packet_ops_spkt;
1372
1373 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1374 struct packet_type *pt, struct net_device *orig_dev)
1375 {
1376 struct sock *sk;
1377 struct sockaddr_pkt *spkt;
1378
1379 /*
1380 * When we registered the protocol we saved the socket in the data
1381 * field for just this event.
1382 */
1383
1384 sk = pt->af_packet_priv;
1385
1386 /*
1387 * Yank back the headers [hope the device set this
1388 * right or kerboom...]
1389 *
1390 * Incoming packets have ll header pulled,
1391 * push it back.
1392 *
1393 * For outgoing ones skb->data == skb_mac_header(skb)
1394 * so that this procedure is noop.
1395 */
1396
1397 if (skb->pkt_type == PACKET_LOOPBACK)
1398 goto out;
1399
1400 if (!net_eq(dev_net(dev), sock_net(sk)))
1401 goto out;
1402
1403 skb = skb_share_check(skb, GFP_ATOMIC);
1404 if (skb == NULL)
1405 goto oom;
1406
1407 /* drop any routing info */
1408 skb_dst_drop(skb);
1409
1410 /* drop conntrack reference */
1411 nf_reset(skb);
1412
1413 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1414
1415 skb_push(skb, skb->data - skb_mac_header(skb));
1416
1417 /*
1418 * The SOCK_PACKET socket receives _all_ frames.
1419 */
1420
1421 spkt->spkt_family = dev->type;
1422 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1423 spkt->spkt_protocol = skb->protocol;
1424
1425 /*
1426 * Charge the memory to the socket. This is done specifically
1427 * to prevent sockets using all the memory up.
1428 */
1429
1430 if (sock_queue_rcv_skb(sk, skb) == 0)
1431 return 0;
1432
1433 out:
1434 kfree_skb(skb);
1435 oom:
1436 return 0;
1437 }
1438
1439
1440 /*
1441 * Output a raw packet to a device layer. This bypasses all the other
1442 * protocol layers and you must therefore supply it with a complete frame
1443 */
1444
1445 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1446 struct msghdr *msg, size_t len)
1447 {
1448 struct sock *sk = sock->sk;
1449 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1450 struct sk_buff *skb = NULL;
1451 struct net_device *dev;
1452 __be16 proto = 0;
1453 int err;
1454 int extra_len = 0;
1455
1456 /*
1457 * Get and verify the address.
1458 */
1459
1460 if (saddr) {
1461 if (msg->msg_namelen < sizeof(struct sockaddr))
1462 return -EINVAL;
1463 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1464 proto = saddr->spkt_protocol;
1465 } else
1466 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1467
1468 /*
1469 * Find the device first to size check it
1470 */
1471
1472 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1473 retry:
1474 rcu_read_lock();
1475 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1476 err = -ENODEV;
1477 if (dev == NULL)
1478 goto out_unlock;
1479
1480 err = -ENETDOWN;
1481 if (!(dev->flags & IFF_UP))
1482 goto out_unlock;
1483
1484 /*
1485 * You may not queue a frame bigger than the mtu. This is the lowest level
1486 * raw protocol and you must do your own fragmentation at this level.
1487 */
1488
1489 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1490 if (!netif_supports_nofcs(dev)) {
1491 err = -EPROTONOSUPPORT;
1492 goto out_unlock;
1493 }
1494 extra_len = 4; /* We're doing our own CRC */
1495 }
1496
1497 err = -EMSGSIZE;
1498 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1499 goto out_unlock;
1500
1501 if (!skb) {
1502 size_t reserved = LL_RESERVED_SPACE(dev);
1503 int tlen = dev->needed_tailroom;
1504 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1505
1506 rcu_read_unlock();
1507 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1508 if (skb == NULL)
1509 return -ENOBUFS;
1510 /* FIXME: Save some space for broken drivers that write a hard
1511 * header at transmission time by themselves. PPP is the notable
1512 * one here. This should really be fixed at the driver level.
1513 */
1514 skb_reserve(skb, reserved);
1515 skb_reset_network_header(skb);
1516
1517 /* Try to align data part correctly */
1518 if (hhlen) {
1519 skb->data -= hhlen;
1520 skb->tail -= hhlen;
1521 if (len < hhlen)
1522 skb_reset_network_header(skb);
1523 }
1524 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1525 if (err)
1526 goto out_free;
1527 goto retry;
1528 }
1529
1530 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1531 /* Earlier code assumed this would be a VLAN pkt,
1532 * double-check this now that we have the actual
1533 * packet in hand.
1534 */
1535 struct ethhdr *ehdr;
1536 skb_reset_mac_header(skb);
1537 ehdr = eth_hdr(skb);
1538 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1539 err = -EMSGSIZE;
1540 goto out_unlock;
1541 }
1542 }
1543
1544 skb->protocol = proto;
1545 skb->dev = dev;
1546 skb->priority = sk->sk_priority;
1547 skb->mark = sk->sk_mark;
1548
1549 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1550
1551 if (unlikely(extra_len == 4))
1552 skb->no_fcs = 1;
1553
1554 skb_probe_transport_header(skb, 0);
1555
1556 dev_queue_xmit(skb);
1557 rcu_read_unlock();
1558 return len;
1559
1560 out_unlock:
1561 rcu_read_unlock();
1562 out_free:
1563 kfree_skb(skb);
1564 return err;
1565 }
1566
1567 static unsigned int run_filter(const struct sk_buff *skb,
1568 const struct sock *sk,
1569 unsigned int res)
1570 {
1571 struct sk_filter *filter;
1572
1573 rcu_read_lock();
1574 filter = rcu_dereference(sk->sk_filter);
1575 if (filter != NULL)
1576 res = SK_RUN_FILTER(filter, skb);
1577 rcu_read_unlock();
1578
1579 return res;
1580 }
1581
1582 /*
1583 * This function makes lazy skb cloning in hope that most of packets
1584 * are discarded by BPF.
1585 *
1586 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1587 * and skb->cb are mangled. It works because (and until) packets
1588 * falling here are owned by current CPU. Output packets are cloned
1589 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1590 * sequencially, so that if we return skb to original state on exit,
1591 * we will not harm anyone.
1592 */
1593
1594 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1595 struct packet_type *pt, struct net_device *orig_dev)
1596 {
1597 struct sock *sk;
1598 struct sockaddr_ll *sll;
1599 struct packet_sock *po;
1600 u8 *skb_head = skb->data;
1601 int skb_len = skb->len;
1602 unsigned int snaplen, res;
1603
1604 if (skb->pkt_type == PACKET_LOOPBACK)
1605 goto drop;
1606
1607 sk = pt->af_packet_priv;
1608 po = pkt_sk(sk);
1609
1610 if (!net_eq(dev_net(dev), sock_net(sk)))
1611 goto drop;
1612
1613 skb->dev = dev;
1614
1615 if (dev->header_ops) {
1616 /* The device has an explicit notion of ll header,
1617 * exported to higher levels.
1618 *
1619 * Otherwise, the device hides details of its frame
1620 * structure, so that corresponding packet head is
1621 * never delivered to user.
1622 */
1623 if (sk->sk_type != SOCK_DGRAM)
1624 skb_push(skb, skb->data - skb_mac_header(skb));
1625 else if (skb->pkt_type == PACKET_OUTGOING) {
1626 /* Special case: outgoing packets have ll header at head */
1627 skb_pull(skb, skb_network_offset(skb));
1628 }
1629 }
1630
1631 snaplen = skb->len;
1632
1633 res = run_filter(skb, sk, snaplen);
1634 if (!res)
1635 goto drop_n_restore;
1636 if (snaplen > res)
1637 snaplen = res;
1638
1639 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1640 goto drop_n_acct;
1641
1642 if (skb_shared(skb)) {
1643 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1644 if (nskb == NULL)
1645 goto drop_n_acct;
1646
1647 if (skb_head != skb->data) {
1648 skb->data = skb_head;
1649 skb->len = skb_len;
1650 }
1651 consume_skb(skb);
1652 skb = nskb;
1653 }
1654
1655 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1656 sizeof(skb->cb));
1657
1658 sll = &PACKET_SKB_CB(skb)->sa.ll;
1659 sll->sll_family = AF_PACKET;
1660 sll->sll_hatype = dev->type;
1661 sll->sll_protocol = skb->protocol;
1662 sll->sll_pkttype = skb->pkt_type;
1663 if (unlikely(po->origdev))
1664 sll->sll_ifindex = orig_dev->ifindex;
1665 else
1666 sll->sll_ifindex = dev->ifindex;
1667
1668 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1669
1670 PACKET_SKB_CB(skb)->origlen = skb->len;
1671
1672 if (pskb_trim(skb, snaplen))
1673 goto drop_n_acct;
1674
1675 skb_set_owner_r(skb, sk);
1676 skb->dev = NULL;
1677 skb_dst_drop(skb);
1678
1679 /* drop conntrack reference */
1680 nf_reset(skb);
1681
1682 spin_lock(&sk->sk_receive_queue.lock);
1683 po->stats.stats1.tp_packets++;
1684 skb->dropcount = atomic_read(&sk->sk_drops);
1685 __skb_queue_tail(&sk->sk_receive_queue, skb);
1686 spin_unlock(&sk->sk_receive_queue.lock);
1687 sk->sk_data_ready(sk, skb->len);
1688 return 0;
1689
1690 drop_n_acct:
1691 spin_lock(&sk->sk_receive_queue.lock);
1692 po->stats.stats1.tp_drops++;
1693 atomic_inc(&sk->sk_drops);
1694 spin_unlock(&sk->sk_receive_queue.lock);
1695
1696 drop_n_restore:
1697 if (skb_head != skb->data && skb_shared(skb)) {
1698 skb->data = skb_head;
1699 skb->len = skb_len;
1700 }
1701 drop:
1702 consume_skb(skb);
1703 return 0;
1704 }
1705
1706 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1707 struct packet_type *pt, struct net_device *orig_dev)
1708 {
1709 struct sock *sk;
1710 struct packet_sock *po;
1711 struct sockaddr_ll *sll;
1712 union tpacket_uhdr h;
1713 u8 *skb_head = skb->data;
1714 int skb_len = skb->len;
1715 unsigned int snaplen, res;
1716 unsigned long status = TP_STATUS_USER;
1717 unsigned short macoff, netoff, hdrlen;
1718 struct sk_buff *copy_skb = NULL;
1719 struct timespec ts;
1720 __u32 ts_status;
1721
1722 if (skb->pkt_type == PACKET_LOOPBACK)
1723 goto drop;
1724
1725 sk = pt->af_packet_priv;
1726 po = pkt_sk(sk);
1727
1728 if (!net_eq(dev_net(dev), sock_net(sk)))
1729 goto drop;
1730
1731 if (dev->header_ops) {
1732 if (sk->sk_type != SOCK_DGRAM)
1733 skb_push(skb, skb->data - skb_mac_header(skb));
1734 else if (skb->pkt_type == PACKET_OUTGOING) {
1735 /* Special case: outgoing packets have ll header at head */
1736 skb_pull(skb, skb_network_offset(skb));
1737 }
1738 }
1739
1740 if (skb->ip_summed == CHECKSUM_PARTIAL)
1741 status |= TP_STATUS_CSUMNOTREADY;
1742
1743 snaplen = skb->len;
1744
1745 res = run_filter(skb, sk, snaplen);
1746 if (!res)
1747 goto drop_n_restore;
1748 if (snaplen > res)
1749 snaplen = res;
1750
1751 if (sk->sk_type == SOCK_DGRAM) {
1752 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1753 po->tp_reserve;
1754 } else {
1755 unsigned int maclen = skb_network_offset(skb);
1756 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1757 (maclen < 16 ? 16 : maclen)) +
1758 po->tp_reserve;
1759 macoff = netoff - maclen;
1760 }
1761 if (po->tp_version <= TPACKET_V2) {
1762 if (macoff + snaplen > po->rx_ring.frame_size) {
1763 if (po->copy_thresh &&
1764 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1765 if (skb_shared(skb)) {
1766 copy_skb = skb_clone(skb, GFP_ATOMIC);
1767 } else {
1768 copy_skb = skb_get(skb);
1769 skb_head = skb->data;
1770 }
1771 if (copy_skb)
1772 skb_set_owner_r(copy_skb, sk);
1773 }
1774 snaplen = po->rx_ring.frame_size - macoff;
1775 if ((int)snaplen < 0)
1776 snaplen = 0;
1777 }
1778 }
1779 spin_lock(&sk->sk_receive_queue.lock);
1780 h.raw = packet_current_rx_frame(po, skb,
1781 TP_STATUS_KERNEL, (macoff+snaplen));
1782 if (!h.raw)
1783 goto ring_is_full;
1784 if (po->tp_version <= TPACKET_V2) {
1785 packet_increment_rx_head(po, &po->rx_ring);
1786 /*
1787 * LOSING will be reported till you read the stats,
1788 * because it's COR - Clear On Read.
1789 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1790 * at packet level.
1791 */
1792 if (po->stats.stats1.tp_drops)
1793 status |= TP_STATUS_LOSING;
1794 }
1795 po->stats.stats1.tp_packets++;
1796 if (copy_skb) {
1797 status |= TP_STATUS_COPY;
1798 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1799 }
1800 spin_unlock(&sk->sk_receive_queue.lock);
1801
1802 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1803
1804 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1805 getnstimeofday(&ts);
1806
1807 status |= ts_status;
1808
1809 switch (po->tp_version) {
1810 case TPACKET_V1:
1811 h.h1->tp_len = skb->len;
1812 h.h1->tp_snaplen = snaplen;
1813 h.h1->tp_mac = macoff;
1814 h.h1->tp_net = netoff;
1815 h.h1->tp_sec = ts.tv_sec;
1816 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1817 hdrlen = sizeof(*h.h1);
1818 break;
1819 case TPACKET_V2:
1820 h.h2->tp_len = skb->len;
1821 h.h2->tp_snaplen = snaplen;
1822 h.h2->tp_mac = macoff;
1823 h.h2->tp_net = netoff;
1824 h.h2->tp_sec = ts.tv_sec;
1825 h.h2->tp_nsec = ts.tv_nsec;
1826 if (vlan_tx_tag_present(skb)) {
1827 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1828 status |= TP_STATUS_VLAN_VALID;
1829 } else {
1830 h.h2->tp_vlan_tci = 0;
1831 }
1832 h.h2->tp_padding = 0;
1833 hdrlen = sizeof(*h.h2);
1834 break;
1835 case TPACKET_V3:
1836 /* tp_nxt_offset,vlan are already populated above.
1837 * So DONT clear those fields here
1838 */
1839 h.h3->tp_status |= status;
1840 h.h3->tp_len = skb->len;
1841 h.h3->tp_snaplen = snaplen;
1842 h.h3->tp_mac = macoff;
1843 h.h3->tp_net = netoff;
1844 h.h3->tp_sec = ts.tv_sec;
1845 h.h3->tp_nsec = ts.tv_nsec;
1846 hdrlen = sizeof(*h.h3);
1847 break;
1848 default:
1849 BUG();
1850 }
1851
1852 sll = h.raw + TPACKET_ALIGN(hdrlen);
1853 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1854 sll->sll_family = AF_PACKET;
1855 sll->sll_hatype = dev->type;
1856 sll->sll_protocol = skb->protocol;
1857 sll->sll_pkttype = skb->pkt_type;
1858 if (unlikely(po->origdev))
1859 sll->sll_ifindex = orig_dev->ifindex;
1860 else
1861 sll->sll_ifindex = dev->ifindex;
1862
1863 smp_mb();
1864 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1865 {
1866 u8 *start, *end;
1867
1868 if (po->tp_version <= TPACKET_V2) {
1869 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1870 + macoff + snaplen);
1871 for (start = h.raw; start < end; start += PAGE_SIZE)
1872 flush_dcache_page(pgv_to_page(start));
1873 }
1874 smp_wmb();
1875 }
1876 #endif
1877 if (po->tp_version <= TPACKET_V2)
1878 __packet_set_status(po, h.raw, status);
1879 else
1880 prb_clear_blk_fill_status(&po->rx_ring);
1881
1882 sk->sk_data_ready(sk, 0);
1883
1884 drop_n_restore:
1885 if (skb_head != skb->data && skb_shared(skb)) {
1886 skb->data = skb_head;
1887 skb->len = skb_len;
1888 }
1889 drop:
1890 kfree_skb(skb);
1891 return 0;
1892
1893 ring_is_full:
1894 po->stats.stats1.tp_drops++;
1895 spin_unlock(&sk->sk_receive_queue.lock);
1896
1897 sk->sk_data_ready(sk, 0);
1898 kfree_skb(copy_skb);
1899 goto drop_n_restore;
1900 }
1901
1902 static void tpacket_destruct_skb(struct sk_buff *skb)
1903 {
1904 struct packet_sock *po = pkt_sk(skb->sk);
1905 void *ph;
1906
1907 if (likely(po->tx_ring.pg_vec)) {
1908 __u32 ts;
1909
1910 ph = skb_shinfo(skb)->destructor_arg;
1911 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1912 atomic_dec(&po->tx_ring.pending);
1913
1914 ts = __packet_set_timestamp(po, ph, skb);
1915 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
1916 }
1917
1918 sock_wfree(skb);
1919 }
1920
1921 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1922 void *frame, struct net_device *dev, int size_max,
1923 __be16 proto, unsigned char *addr, int hlen)
1924 {
1925 union tpacket_uhdr ph;
1926 int to_write, offset, len, tp_len, nr_frags, len_max;
1927 struct socket *sock = po->sk.sk_socket;
1928 struct page *page;
1929 void *data;
1930 int err;
1931
1932 ph.raw = frame;
1933
1934 skb->protocol = proto;
1935 skb->dev = dev;
1936 skb->priority = po->sk.sk_priority;
1937 skb->mark = po->sk.sk_mark;
1938 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
1939 skb_shinfo(skb)->destructor_arg = ph.raw;
1940
1941 switch (po->tp_version) {
1942 case TPACKET_V2:
1943 tp_len = ph.h2->tp_len;
1944 break;
1945 default:
1946 tp_len = ph.h1->tp_len;
1947 break;
1948 }
1949 if (unlikely(tp_len > size_max)) {
1950 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1951 return -EMSGSIZE;
1952 }
1953
1954 skb_reserve(skb, hlen);
1955 skb_reset_network_header(skb);
1956 skb_probe_transport_header(skb, 0);
1957
1958 if (po->tp_tx_has_off) {
1959 int off_min, off_max, off;
1960 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
1961 off_max = po->tx_ring.frame_size - tp_len;
1962 if (sock->type == SOCK_DGRAM) {
1963 switch (po->tp_version) {
1964 case TPACKET_V2:
1965 off = ph.h2->tp_net;
1966 break;
1967 default:
1968 off = ph.h1->tp_net;
1969 break;
1970 }
1971 } else {
1972 switch (po->tp_version) {
1973 case TPACKET_V2:
1974 off = ph.h2->tp_mac;
1975 break;
1976 default:
1977 off = ph.h1->tp_mac;
1978 break;
1979 }
1980 }
1981 if (unlikely((off < off_min) || (off_max < off)))
1982 return -EINVAL;
1983 data = ph.raw + off;
1984 } else {
1985 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1986 }
1987 to_write = tp_len;
1988
1989 if (sock->type == SOCK_DGRAM) {
1990 err = dev_hard_header(skb, dev, ntohs(proto), addr,
1991 NULL, tp_len);
1992 if (unlikely(err < 0))
1993 return -EINVAL;
1994 } else if (dev->hard_header_len) {
1995 /* net device doesn't like empty head */
1996 if (unlikely(tp_len <= dev->hard_header_len)) {
1997 pr_err("packet size is too short (%d < %d)\n",
1998 tp_len, dev->hard_header_len);
1999 return -EINVAL;
2000 }
2001
2002 skb_push(skb, dev->hard_header_len);
2003 err = skb_store_bits(skb, 0, data,
2004 dev->hard_header_len);
2005 if (unlikely(err))
2006 return err;
2007
2008 data += dev->hard_header_len;
2009 to_write -= dev->hard_header_len;
2010 }
2011
2012 offset = offset_in_page(data);
2013 len_max = PAGE_SIZE - offset;
2014 len = ((to_write > len_max) ? len_max : to_write);
2015
2016 skb->data_len = to_write;
2017 skb->len += to_write;
2018 skb->truesize += to_write;
2019 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2020
2021 while (likely(to_write)) {
2022 nr_frags = skb_shinfo(skb)->nr_frags;
2023
2024 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2025 pr_err("Packet exceed the number of skb frags(%lu)\n",
2026 MAX_SKB_FRAGS);
2027 return -EFAULT;
2028 }
2029
2030 page = pgv_to_page(data);
2031 data += len;
2032 flush_dcache_page(page);
2033 get_page(page);
2034 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2035 to_write -= len;
2036 offset = 0;
2037 len_max = PAGE_SIZE;
2038 len = ((to_write > len_max) ? len_max : to_write);
2039 }
2040
2041 return tp_len;
2042 }
2043
2044 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2045 {
2046 struct sk_buff *skb;
2047 struct net_device *dev;
2048 __be16 proto;
2049 bool need_rls_dev = false;
2050 int err, reserve = 0;
2051 void *ph;
2052 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2053 int tp_len, size_max;
2054 unsigned char *addr;
2055 int len_sum = 0;
2056 int status = TP_STATUS_AVAILABLE;
2057 int hlen, tlen;
2058
2059 mutex_lock(&po->pg_vec_lock);
2060
2061 if (saddr == NULL) {
2062 dev = po->prot_hook.dev;
2063 proto = po->num;
2064 addr = NULL;
2065 } else {
2066 err = -EINVAL;
2067 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2068 goto out;
2069 if (msg->msg_namelen < (saddr->sll_halen
2070 + offsetof(struct sockaddr_ll,
2071 sll_addr)))
2072 goto out;
2073 proto = saddr->sll_protocol;
2074 addr = saddr->sll_addr;
2075 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2076 need_rls_dev = true;
2077 }
2078
2079 err = -ENXIO;
2080 if (unlikely(dev == NULL))
2081 goto out;
2082
2083 reserve = dev->hard_header_len;
2084
2085 err = -ENETDOWN;
2086 if (unlikely(!(dev->flags & IFF_UP)))
2087 goto out_put;
2088
2089 size_max = po->tx_ring.frame_size
2090 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2091
2092 if (size_max > dev->mtu + reserve)
2093 size_max = dev->mtu + reserve;
2094
2095 do {
2096 ph = packet_current_frame(po, &po->tx_ring,
2097 TP_STATUS_SEND_REQUEST);
2098
2099 if (unlikely(ph == NULL)) {
2100 schedule();
2101 continue;
2102 }
2103
2104 status = TP_STATUS_SEND_REQUEST;
2105 hlen = LL_RESERVED_SPACE(dev);
2106 tlen = dev->needed_tailroom;
2107 skb = sock_alloc_send_skb(&po->sk,
2108 hlen + tlen + sizeof(struct sockaddr_ll),
2109 0, &err);
2110
2111 if (unlikely(skb == NULL))
2112 goto out_status;
2113
2114 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2115 addr, hlen);
2116
2117 if (unlikely(tp_len < 0)) {
2118 if (po->tp_loss) {
2119 __packet_set_status(po, ph,
2120 TP_STATUS_AVAILABLE);
2121 packet_increment_head(&po->tx_ring);
2122 kfree_skb(skb);
2123 continue;
2124 } else {
2125 status = TP_STATUS_WRONG_FORMAT;
2126 err = tp_len;
2127 goto out_status;
2128 }
2129 }
2130
2131 skb->destructor = tpacket_destruct_skb;
2132 __packet_set_status(po, ph, TP_STATUS_SENDING);
2133 atomic_inc(&po->tx_ring.pending);
2134
2135 status = TP_STATUS_SEND_REQUEST;
2136 err = dev_queue_xmit(skb);
2137 if (unlikely(err > 0)) {
2138 err = net_xmit_errno(err);
2139 if (err && __packet_get_status(po, ph) ==
2140 TP_STATUS_AVAILABLE) {
2141 /* skb was destructed already */
2142 skb = NULL;
2143 goto out_status;
2144 }
2145 /*
2146 * skb was dropped but not destructed yet;
2147 * let's treat it like congestion or err < 0
2148 */
2149 err = 0;
2150 }
2151 packet_increment_head(&po->tx_ring);
2152 len_sum += tp_len;
2153 } while (likely((ph != NULL) ||
2154 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2155 (atomic_read(&po->tx_ring.pending))))
2156 );
2157
2158 err = len_sum;
2159 goto out_put;
2160
2161 out_status:
2162 __packet_set_status(po, ph, status);
2163 kfree_skb(skb);
2164 out_put:
2165 if (need_rls_dev)
2166 dev_put(dev);
2167 out:
2168 mutex_unlock(&po->pg_vec_lock);
2169 return err;
2170 }
2171
2172 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2173 size_t reserve, size_t len,
2174 size_t linear, int noblock,
2175 int *err)
2176 {
2177 struct sk_buff *skb;
2178
2179 /* Under a page? Don't bother with paged skb. */
2180 if (prepad + len < PAGE_SIZE || !linear)
2181 linear = len;
2182
2183 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2184 err);
2185 if (!skb)
2186 return NULL;
2187
2188 skb_reserve(skb, reserve);
2189 skb_put(skb, linear);
2190 skb->data_len = len - linear;
2191 skb->len += len - linear;
2192
2193 return skb;
2194 }
2195
2196 static int packet_snd(struct socket *sock,
2197 struct msghdr *msg, size_t len)
2198 {
2199 struct sock *sk = sock->sk;
2200 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2201 struct sk_buff *skb;
2202 struct net_device *dev;
2203 __be16 proto;
2204 bool need_rls_dev = false;
2205 unsigned char *addr;
2206 int err, reserve = 0;
2207 struct virtio_net_hdr vnet_hdr = { 0 };
2208 int offset = 0;
2209 int vnet_hdr_len;
2210 struct packet_sock *po = pkt_sk(sk);
2211 unsigned short gso_type = 0;
2212 int hlen, tlen;
2213 int extra_len = 0;
2214
2215 /*
2216 * Get and verify the address.
2217 */
2218
2219 if (saddr == NULL) {
2220 dev = po->prot_hook.dev;
2221 proto = po->num;
2222 addr = NULL;
2223 } else {
2224 err = -EINVAL;
2225 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2226 goto out;
2227 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2228 goto out;
2229 proto = saddr->sll_protocol;
2230 addr = saddr->sll_addr;
2231 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2232 need_rls_dev = true;
2233 }
2234
2235 err = -ENXIO;
2236 if (dev == NULL)
2237 goto out_unlock;
2238 if (sock->type == SOCK_RAW)
2239 reserve = dev->hard_header_len;
2240
2241 err = -ENETDOWN;
2242 if (!(dev->flags & IFF_UP))
2243 goto out_unlock;
2244
2245 if (po->has_vnet_hdr) {
2246 vnet_hdr_len = sizeof(vnet_hdr);
2247
2248 err = -EINVAL;
2249 if (len < vnet_hdr_len)
2250 goto out_unlock;
2251
2252 len -= vnet_hdr_len;
2253
2254 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2255 vnet_hdr_len);
2256 if (err < 0)
2257 goto out_unlock;
2258
2259 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2260 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2261 vnet_hdr.hdr_len))
2262 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2263 vnet_hdr.csum_offset + 2;
2264
2265 err = -EINVAL;
2266 if (vnet_hdr.hdr_len > len)
2267 goto out_unlock;
2268
2269 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2270 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2271 case VIRTIO_NET_HDR_GSO_TCPV4:
2272 gso_type = SKB_GSO_TCPV4;
2273 break;
2274 case VIRTIO_NET_HDR_GSO_TCPV6:
2275 gso_type = SKB_GSO_TCPV6;
2276 break;
2277 case VIRTIO_NET_HDR_GSO_UDP:
2278 gso_type = SKB_GSO_UDP;
2279 break;
2280 default:
2281 goto out_unlock;
2282 }
2283
2284 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2285 gso_type |= SKB_GSO_TCP_ECN;
2286
2287 if (vnet_hdr.gso_size == 0)
2288 goto out_unlock;
2289
2290 }
2291 }
2292
2293 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2294 if (!netif_supports_nofcs(dev)) {
2295 err = -EPROTONOSUPPORT;
2296 goto out_unlock;
2297 }
2298 extra_len = 4; /* We're doing our own CRC */
2299 }
2300
2301 err = -EMSGSIZE;
2302 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2303 goto out_unlock;
2304
2305 err = -ENOBUFS;
2306 hlen = LL_RESERVED_SPACE(dev);
2307 tlen = dev->needed_tailroom;
2308 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2309 msg->msg_flags & MSG_DONTWAIT, &err);
2310 if (skb == NULL)
2311 goto out_unlock;
2312
2313 skb_set_network_header(skb, reserve);
2314
2315 err = -EINVAL;
2316 if (sock->type == SOCK_DGRAM &&
2317 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2318 goto out_free;
2319
2320 /* Returns -EFAULT on error */
2321 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2322 if (err)
2323 goto out_free;
2324
2325 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2326
2327 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2328 /* Earlier code assumed this would be a VLAN pkt,
2329 * double-check this now that we have the actual
2330 * packet in hand.
2331 */
2332 struct ethhdr *ehdr;
2333 skb_reset_mac_header(skb);
2334 ehdr = eth_hdr(skb);
2335 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2336 err = -EMSGSIZE;
2337 goto out_free;
2338 }
2339 }
2340
2341 skb->protocol = proto;
2342 skb->dev = dev;
2343 skb->priority = sk->sk_priority;
2344 skb->mark = sk->sk_mark;
2345
2346 if (po->has_vnet_hdr) {
2347 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2348 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2349 vnet_hdr.csum_offset)) {
2350 err = -EINVAL;
2351 goto out_free;
2352 }
2353 }
2354
2355 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2356 skb_shinfo(skb)->gso_type = gso_type;
2357
2358 /* Header must be checked, and gso_segs computed. */
2359 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2360 skb_shinfo(skb)->gso_segs = 0;
2361
2362 len += vnet_hdr_len;
2363 }
2364
2365 skb_probe_transport_header(skb, reserve);
2366
2367 if (unlikely(extra_len == 4))
2368 skb->no_fcs = 1;
2369
2370 /*
2371 * Now send it
2372 */
2373
2374 err = dev_queue_xmit(skb);
2375 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2376 goto out_unlock;
2377
2378 if (need_rls_dev)
2379 dev_put(dev);
2380
2381 return len;
2382
2383 out_free:
2384 kfree_skb(skb);
2385 out_unlock:
2386 if (dev && need_rls_dev)
2387 dev_put(dev);
2388 out:
2389 return err;
2390 }
2391
2392 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2393 struct msghdr *msg, size_t len)
2394 {
2395 struct sock *sk = sock->sk;
2396 struct packet_sock *po = pkt_sk(sk);
2397 if (po->tx_ring.pg_vec)
2398 return tpacket_snd(po, msg);
2399 else
2400 return packet_snd(sock, msg, len);
2401 }
2402
2403 /*
2404 * Close a PACKET socket. This is fairly simple. We immediately go
2405 * to 'closed' state and remove our protocol entry in the device list.
2406 */
2407
2408 static int packet_release(struct socket *sock)
2409 {
2410 struct sock *sk = sock->sk;
2411 struct packet_sock *po;
2412 struct net *net;
2413 union tpacket_req_u req_u;
2414
2415 if (!sk)
2416 return 0;
2417
2418 net = sock_net(sk);
2419 po = pkt_sk(sk);
2420
2421 mutex_lock(&net->packet.sklist_lock);
2422 sk_del_node_init_rcu(sk);
2423 mutex_unlock(&net->packet.sklist_lock);
2424
2425 preempt_disable();
2426 sock_prot_inuse_add(net, sk->sk_prot, -1);
2427 preempt_enable();
2428
2429 spin_lock(&po->bind_lock);
2430 unregister_prot_hook(sk, false);
2431 if (po->prot_hook.dev) {
2432 dev_put(po->prot_hook.dev);
2433 po->prot_hook.dev = NULL;
2434 }
2435 spin_unlock(&po->bind_lock);
2436
2437 packet_flush_mclist(sk);
2438
2439 if (po->rx_ring.pg_vec) {
2440 memset(&req_u, 0, sizeof(req_u));
2441 packet_set_ring(sk, &req_u, 1, 0);
2442 }
2443
2444 if (po->tx_ring.pg_vec) {
2445 memset(&req_u, 0, sizeof(req_u));
2446 packet_set_ring(sk, &req_u, 1, 1);
2447 }
2448
2449 fanout_release(sk);
2450
2451 synchronize_net();
2452 /*
2453 * Now the socket is dead. No more input will appear.
2454 */
2455 sock_orphan(sk);
2456 sock->sk = NULL;
2457
2458 /* Purge queues */
2459
2460 skb_queue_purge(&sk->sk_receive_queue);
2461 sk_refcnt_debug_release(sk);
2462
2463 sock_put(sk);
2464 return 0;
2465 }
2466
2467 /*
2468 * Attach a packet hook.
2469 */
2470
2471 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2472 {
2473 struct packet_sock *po = pkt_sk(sk);
2474
2475 if (po->fanout) {
2476 if (dev)
2477 dev_put(dev);
2478
2479 return -EINVAL;
2480 }
2481
2482 lock_sock(sk);
2483
2484 spin_lock(&po->bind_lock);
2485 unregister_prot_hook(sk, true);
2486 po->num = protocol;
2487 po->prot_hook.type = protocol;
2488 if (po->prot_hook.dev)
2489 dev_put(po->prot_hook.dev);
2490 po->prot_hook.dev = dev;
2491
2492 po->ifindex = dev ? dev->ifindex : 0;
2493
2494 if (protocol == 0)
2495 goto out_unlock;
2496
2497 if (!dev || (dev->flags & IFF_UP)) {
2498 register_prot_hook(sk);
2499 } else {
2500 sk->sk_err = ENETDOWN;
2501 if (!sock_flag(sk, SOCK_DEAD))
2502 sk->sk_error_report(sk);
2503 }
2504
2505 out_unlock:
2506 spin_unlock(&po->bind_lock);
2507 release_sock(sk);
2508 return 0;
2509 }
2510
2511 /*
2512 * Bind a packet socket to a device
2513 */
2514
2515 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2516 int addr_len)
2517 {
2518 struct sock *sk = sock->sk;
2519 char name[15];
2520 struct net_device *dev;
2521 int err = -ENODEV;
2522
2523 /*
2524 * Check legality
2525 */
2526
2527 if (addr_len != sizeof(struct sockaddr))
2528 return -EINVAL;
2529 strlcpy(name, uaddr->sa_data, sizeof(name));
2530
2531 dev = dev_get_by_name(sock_net(sk), name);
2532 if (dev)
2533 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2534 return err;
2535 }
2536
2537 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2538 {
2539 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2540 struct sock *sk = sock->sk;
2541 struct net_device *dev = NULL;
2542 int err;
2543
2544
2545 /*
2546 * Check legality
2547 */
2548
2549 if (addr_len < sizeof(struct sockaddr_ll))
2550 return -EINVAL;
2551 if (sll->sll_family != AF_PACKET)
2552 return -EINVAL;
2553
2554 if (sll->sll_ifindex) {
2555 err = -ENODEV;
2556 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2557 if (dev == NULL)
2558 goto out;
2559 }
2560 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2561
2562 out:
2563 return err;
2564 }
2565
2566 static struct proto packet_proto = {
2567 .name = "PACKET",
2568 .owner = THIS_MODULE,
2569 .obj_size = sizeof(struct packet_sock),
2570 };
2571
2572 /*
2573 * Create a packet of type SOCK_PACKET.
2574 */
2575
2576 static int packet_create(struct net *net, struct socket *sock, int protocol,
2577 int kern)
2578 {
2579 struct sock *sk;
2580 struct packet_sock *po;
2581 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2582 int err;
2583
2584 if (!ns_capable(net->user_ns, CAP_NET_RAW))
2585 return -EPERM;
2586 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2587 sock->type != SOCK_PACKET)
2588 return -ESOCKTNOSUPPORT;
2589
2590 sock->state = SS_UNCONNECTED;
2591
2592 err = -ENOBUFS;
2593 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2594 if (sk == NULL)
2595 goto out;
2596
2597 sock->ops = &packet_ops;
2598 if (sock->type == SOCK_PACKET)
2599 sock->ops = &packet_ops_spkt;
2600
2601 sock_init_data(sock, sk);
2602
2603 po = pkt_sk(sk);
2604 sk->sk_family = PF_PACKET;
2605 po->num = proto;
2606
2607 sk->sk_destruct = packet_sock_destruct;
2608 sk_refcnt_debug_inc(sk);
2609
2610 /*
2611 * Attach a protocol block
2612 */
2613
2614 spin_lock_init(&po->bind_lock);
2615 mutex_init(&po->pg_vec_lock);
2616 po->prot_hook.func = packet_rcv;
2617
2618 if (sock->type == SOCK_PACKET)
2619 po->prot_hook.func = packet_rcv_spkt;
2620
2621 po->prot_hook.af_packet_priv = sk;
2622
2623 if (proto) {
2624 po->prot_hook.type = proto;
2625 register_prot_hook(sk);
2626 }
2627
2628 mutex_lock(&net->packet.sklist_lock);
2629 sk_add_node_rcu(sk, &net->packet.sklist);
2630 mutex_unlock(&net->packet.sklist_lock);
2631
2632 preempt_disable();
2633 sock_prot_inuse_add(net, &packet_proto, 1);
2634 preempt_enable();
2635
2636 return 0;
2637 out:
2638 return err;
2639 }
2640
2641 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2642 {
2643 struct sock_exterr_skb *serr;
2644 struct sk_buff *skb, *skb2;
2645 int copied, err;
2646
2647 err = -EAGAIN;
2648 skb = skb_dequeue(&sk->sk_error_queue);
2649 if (skb == NULL)
2650 goto out;
2651
2652 copied = skb->len;
2653 if (copied > len) {
2654 msg->msg_flags |= MSG_TRUNC;
2655 copied = len;
2656 }
2657 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2658 if (err)
2659 goto out_free_skb;
2660
2661 sock_recv_timestamp(msg, sk, skb);
2662
2663 serr = SKB_EXT_ERR(skb);
2664 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2665 sizeof(serr->ee), &serr->ee);
2666
2667 msg->msg_flags |= MSG_ERRQUEUE;
2668 err = copied;
2669
2670 /* Reset and regenerate socket error */
2671 spin_lock_bh(&sk->sk_error_queue.lock);
2672 sk->sk_err = 0;
2673 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2674 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2675 spin_unlock_bh(&sk->sk_error_queue.lock);
2676 sk->sk_error_report(sk);
2677 } else
2678 spin_unlock_bh(&sk->sk_error_queue.lock);
2679
2680 out_free_skb:
2681 kfree_skb(skb);
2682 out:
2683 return err;
2684 }
2685
2686 /*
2687 * Pull a packet from our receive queue and hand it to the user.
2688 * If necessary we block.
2689 */
2690
2691 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2692 struct msghdr *msg, size_t len, int flags)
2693 {
2694 struct sock *sk = sock->sk;
2695 struct sk_buff *skb;
2696 int copied, err;
2697 struct sockaddr_ll *sll;
2698 int vnet_hdr_len = 0;
2699
2700 err = -EINVAL;
2701 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2702 goto out;
2703
2704 #if 0
2705 /* What error should we return now? EUNATTACH? */
2706 if (pkt_sk(sk)->ifindex < 0)
2707 return -ENODEV;
2708 #endif
2709
2710 if (flags & MSG_ERRQUEUE) {
2711 err = packet_recv_error(sk, msg, len);
2712 goto out;
2713 }
2714
2715 /*
2716 * Call the generic datagram receiver. This handles all sorts
2717 * of horrible races and re-entrancy so we can forget about it
2718 * in the protocol layers.
2719 *
2720 * Now it will return ENETDOWN, if device have just gone down,
2721 * but then it will block.
2722 */
2723
2724 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2725
2726 /*
2727 * An error occurred so return it. Because skb_recv_datagram()
2728 * handles the blocking we don't see and worry about blocking
2729 * retries.
2730 */
2731
2732 if (skb == NULL)
2733 goto out;
2734
2735 if (pkt_sk(sk)->has_vnet_hdr) {
2736 struct virtio_net_hdr vnet_hdr = { 0 };
2737
2738 err = -EINVAL;
2739 vnet_hdr_len = sizeof(vnet_hdr);
2740 if (len < vnet_hdr_len)
2741 goto out_free;
2742
2743 len -= vnet_hdr_len;
2744
2745 if (skb_is_gso(skb)) {
2746 struct skb_shared_info *sinfo = skb_shinfo(skb);
2747
2748 /* This is a hint as to how much should be linear. */
2749 vnet_hdr.hdr_len = skb_headlen(skb);
2750 vnet_hdr.gso_size = sinfo->gso_size;
2751 if (sinfo->gso_type & SKB_GSO_TCPV4)
2752 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2753 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2754 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2755 else if (sinfo->gso_type & SKB_GSO_UDP)
2756 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2757 else if (sinfo->gso_type & SKB_GSO_FCOE)
2758 goto out_free;
2759 else
2760 BUG();
2761 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2762 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2763 } else
2764 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2765
2766 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2767 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2768 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2769 vnet_hdr.csum_offset = skb->csum_offset;
2770 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2771 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2772 } /* else everything is zero */
2773
2774 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2775 vnet_hdr_len);
2776 if (err < 0)
2777 goto out_free;
2778 }
2779
2780 /*
2781 * If the address length field is there to be filled in, we fill
2782 * it in now.
2783 */
2784
2785 sll = &PACKET_SKB_CB(skb)->sa.ll;
2786 if (sock->type == SOCK_PACKET)
2787 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2788 else
2789 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
2790
2791 /*
2792 * You lose any data beyond the buffer you gave. If it worries a
2793 * user program they can ask the device for its MTU anyway.
2794 */
2795
2796 copied = skb->len;
2797 if (copied > len) {
2798 copied = len;
2799 msg->msg_flags |= MSG_TRUNC;
2800 }
2801
2802 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2803 if (err)
2804 goto out_free;
2805
2806 sock_recv_ts_and_drops(msg, sk, skb);
2807
2808 if (msg->msg_name)
2809 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2810 msg->msg_namelen);
2811
2812 if (pkt_sk(sk)->auxdata) {
2813 struct tpacket_auxdata aux;
2814
2815 aux.tp_status = TP_STATUS_USER;
2816 if (skb->ip_summed == CHECKSUM_PARTIAL)
2817 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2818 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2819 aux.tp_snaplen = skb->len;
2820 aux.tp_mac = 0;
2821 aux.tp_net = skb_network_offset(skb);
2822 if (vlan_tx_tag_present(skb)) {
2823 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2824 aux.tp_status |= TP_STATUS_VLAN_VALID;
2825 } else {
2826 aux.tp_vlan_tci = 0;
2827 }
2828 aux.tp_padding = 0;
2829 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2830 }
2831
2832 /*
2833 * Free or return the buffer as appropriate. Again this
2834 * hides all the races and re-entrancy issues from us.
2835 */
2836 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2837
2838 out_free:
2839 skb_free_datagram(sk, skb);
2840 out:
2841 return err;
2842 }
2843
2844 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2845 int *uaddr_len, int peer)
2846 {
2847 struct net_device *dev;
2848 struct sock *sk = sock->sk;
2849
2850 if (peer)
2851 return -EOPNOTSUPP;
2852
2853 uaddr->sa_family = AF_PACKET;
2854 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
2855 rcu_read_lock();
2856 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2857 if (dev)
2858 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
2859 rcu_read_unlock();
2860 *uaddr_len = sizeof(*uaddr);
2861
2862 return 0;
2863 }
2864
2865 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2866 int *uaddr_len, int peer)
2867 {
2868 struct net_device *dev;
2869 struct sock *sk = sock->sk;
2870 struct packet_sock *po = pkt_sk(sk);
2871 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2872
2873 if (peer)
2874 return -EOPNOTSUPP;
2875
2876 sll->sll_family = AF_PACKET;
2877 sll->sll_ifindex = po->ifindex;
2878 sll->sll_protocol = po->num;
2879 sll->sll_pkttype = 0;
2880 rcu_read_lock();
2881 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2882 if (dev) {
2883 sll->sll_hatype = dev->type;
2884 sll->sll_halen = dev->addr_len;
2885 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2886 } else {
2887 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2888 sll->sll_halen = 0;
2889 }
2890 rcu_read_unlock();
2891 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2892
2893 return 0;
2894 }
2895
2896 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2897 int what)
2898 {
2899 switch (i->type) {
2900 case PACKET_MR_MULTICAST:
2901 if (i->alen != dev->addr_len)
2902 return -EINVAL;
2903 if (what > 0)
2904 return dev_mc_add(dev, i->addr);
2905 else
2906 return dev_mc_del(dev, i->addr);
2907 break;
2908 case PACKET_MR_PROMISC:
2909 return dev_set_promiscuity(dev, what);
2910 break;
2911 case PACKET_MR_ALLMULTI:
2912 return dev_set_allmulti(dev, what);
2913 break;
2914 case PACKET_MR_UNICAST:
2915 if (i->alen != dev->addr_len)
2916 return -EINVAL;
2917 if (what > 0)
2918 return dev_uc_add(dev, i->addr);
2919 else
2920 return dev_uc_del(dev, i->addr);
2921 break;
2922 default:
2923 break;
2924 }
2925 return 0;
2926 }
2927
2928 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2929 {
2930 for ( ; i; i = i->next) {
2931 if (i->ifindex == dev->ifindex)
2932 packet_dev_mc(dev, i, what);
2933 }
2934 }
2935
2936 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2937 {
2938 struct packet_sock *po = pkt_sk(sk);
2939 struct packet_mclist *ml, *i;
2940 struct net_device *dev;
2941 int err;
2942
2943 rtnl_lock();
2944
2945 err = -ENODEV;
2946 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2947 if (!dev)
2948 goto done;
2949
2950 err = -EINVAL;
2951 if (mreq->mr_alen > dev->addr_len)
2952 goto done;
2953
2954 err = -ENOBUFS;
2955 i = kmalloc(sizeof(*i), GFP_KERNEL);
2956 if (i == NULL)
2957 goto done;
2958
2959 err = 0;
2960 for (ml = po->mclist; ml; ml = ml->next) {
2961 if (ml->ifindex == mreq->mr_ifindex &&
2962 ml->type == mreq->mr_type &&
2963 ml->alen == mreq->mr_alen &&
2964 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2965 ml->count++;
2966 /* Free the new element ... */
2967 kfree(i);
2968 goto done;
2969 }
2970 }
2971
2972 i->type = mreq->mr_type;
2973 i->ifindex = mreq->mr_ifindex;
2974 i->alen = mreq->mr_alen;
2975 memcpy(i->addr, mreq->mr_address, i->alen);
2976 i->count = 1;
2977 i->next = po->mclist;
2978 po->mclist = i;
2979 err = packet_dev_mc(dev, i, 1);
2980 if (err) {
2981 po->mclist = i->next;
2982 kfree(i);
2983 }
2984
2985 done:
2986 rtnl_unlock();
2987 return err;
2988 }
2989
2990 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2991 {
2992 struct packet_mclist *ml, **mlp;
2993
2994 rtnl_lock();
2995
2996 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2997 if (ml->ifindex == mreq->mr_ifindex &&
2998 ml->type == mreq->mr_type &&
2999 ml->alen == mreq->mr_alen &&
3000 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3001 if (--ml->count == 0) {
3002 struct net_device *dev;
3003 *mlp = ml->next;
3004 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3005 if (dev)
3006 packet_dev_mc(dev, ml, -1);
3007 kfree(ml);
3008 }
3009 rtnl_unlock();
3010 return 0;
3011 }
3012 }
3013 rtnl_unlock();
3014 return -EADDRNOTAVAIL;
3015 }
3016
3017 static void packet_flush_mclist(struct sock *sk)
3018 {
3019 struct packet_sock *po = pkt_sk(sk);
3020 struct packet_mclist *ml;
3021
3022 if (!po->mclist)
3023 return;
3024
3025 rtnl_lock();
3026 while ((ml = po->mclist) != NULL) {
3027 struct net_device *dev;
3028
3029 po->mclist = ml->next;
3030 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3031 if (dev != NULL)
3032 packet_dev_mc(dev, ml, -1);
3033 kfree(ml);
3034 }
3035 rtnl_unlock();
3036 }
3037
3038 static int
3039 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3040 {
3041 struct sock *sk = sock->sk;
3042 struct packet_sock *po = pkt_sk(sk);
3043 int ret;
3044
3045 if (level != SOL_PACKET)
3046 return -ENOPROTOOPT;
3047
3048 switch (optname) {
3049 case PACKET_ADD_MEMBERSHIP:
3050 case PACKET_DROP_MEMBERSHIP:
3051 {
3052 struct packet_mreq_max mreq;
3053 int len = optlen;
3054 memset(&mreq, 0, sizeof(mreq));
3055 if (len < sizeof(struct packet_mreq))
3056 return -EINVAL;
3057 if (len > sizeof(mreq))
3058 len = sizeof(mreq);
3059 if (copy_from_user(&mreq, optval, len))
3060 return -EFAULT;
3061 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3062 return -EINVAL;
3063 if (optname == PACKET_ADD_MEMBERSHIP)
3064 ret = packet_mc_add(sk, &mreq);
3065 else
3066 ret = packet_mc_drop(sk, &mreq);
3067 return ret;
3068 }
3069
3070 case PACKET_RX_RING:
3071 case PACKET_TX_RING:
3072 {
3073 union tpacket_req_u req_u;
3074 int len;
3075
3076 switch (po->tp_version) {
3077 case TPACKET_V1:
3078 case TPACKET_V2:
3079 len = sizeof(req_u.req);
3080 break;
3081 case TPACKET_V3:
3082 default:
3083 len = sizeof(req_u.req3);
3084 break;
3085 }
3086 if (optlen < len)
3087 return -EINVAL;
3088 if (pkt_sk(sk)->has_vnet_hdr)
3089 return -EINVAL;
3090 if (copy_from_user(&req_u.req, optval, len))
3091 return -EFAULT;
3092 return packet_set_ring(sk, &req_u, 0,
3093 optname == PACKET_TX_RING);
3094 }
3095 case PACKET_COPY_THRESH:
3096 {
3097 int val;
3098
3099 if (optlen != sizeof(val))
3100 return -EINVAL;
3101 if (copy_from_user(&val, optval, sizeof(val)))
3102 return -EFAULT;
3103
3104 pkt_sk(sk)->copy_thresh = val;
3105 return 0;
3106 }
3107 case PACKET_VERSION:
3108 {
3109 int val;
3110
3111 if (optlen != sizeof(val))
3112 return -EINVAL;
3113 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3114 return -EBUSY;
3115 if (copy_from_user(&val, optval, sizeof(val)))
3116 return -EFAULT;
3117 switch (val) {
3118 case TPACKET_V1:
3119 case TPACKET_V2:
3120 case TPACKET_V3:
3121 po->tp_version = val;
3122 return 0;
3123 default:
3124 return -EINVAL;
3125 }
3126 }
3127 case PACKET_RESERVE:
3128 {
3129 unsigned int val;
3130
3131 if (optlen != sizeof(val))
3132 return -EINVAL;
3133 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3134 return -EBUSY;
3135 if (copy_from_user(&val, optval, sizeof(val)))
3136 return -EFAULT;
3137 po->tp_reserve = val;
3138 return 0;
3139 }
3140 case PACKET_LOSS:
3141 {
3142 unsigned int val;
3143
3144 if (optlen != sizeof(val))
3145 return -EINVAL;
3146 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3147 return -EBUSY;
3148 if (copy_from_user(&val, optval, sizeof(val)))
3149 return -EFAULT;
3150 po->tp_loss = !!val;
3151 return 0;
3152 }
3153 case PACKET_AUXDATA:
3154 {
3155 int val;
3156
3157 if (optlen < sizeof(val))
3158 return -EINVAL;
3159 if (copy_from_user(&val, optval, sizeof(val)))
3160 return -EFAULT;
3161
3162 po->auxdata = !!val;
3163 return 0;
3164 }
3165 case PACKET_ORIGDEV:
3166 {
3167 int val;
3168
3169 if (optlen < sizeof(val))
3170 return -EINVAL;
3171 if (copy_from_user(&val, optval, sizeof(val)))
3172 return -EFAULT;
3173
3174 po->origdev = !!val;
3175 return 0;
3176 }
3177 case PACKET_VNET_HDR:
3178 {
3179 int val;
3180
3181 if (sock->type != SOCK_RAW)
3182 return -EINVAL;
3183 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3184 return -EBUSY;
3185 if (optlen < sizeof(val))
3186 return -EINVAL;
3187 if (copy_from_user(&val, optval, sizeof(val)))
3188 return -EFAULT;
3189
3190 po->has_vnet_hdr = !!val;
3191 return 0;
3192 }
3193 case PACKET_TIMESTAMP:
3194 {
3195 int val;
3196
3197 if (optlen != sizeof(val))
3198 return -EINVAL;
3199 if (copy_from_user(&val, optval, sizeof(val)))
3200 return -EFAULT;
3201
3202 po->tp_tstamp = val;
3203 return 0;
3204 }
3205 case PACKET_FANOUT:
3206 {
3207 int val;
3208
3209 if (optlen != sizeof(val))
3210 return -EINVAL;
3211 if (copy_from_user(&val, optval, sizeof(val)))
3212 return -EFAULT;
3213
3214 return fanout_add(sk, val & 0xffff, val >> 16);
3215 }
3216 case PACKET_TX_HAS_OFF:
3217 {
3218 unsigned int val;
3219
3220 if (optlen != sizeof(val))
3221 return -EINVAL;
3222 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3223 return -EBUSY;
3224 if (copy_from_user(&val, optval, sizeof(val)))
3225 return -EFAULT;
3226 po->tp_tx_has_off = !!val;
3227 return 0;
3228 }
3229 default:
3230 return -ENOPROTOOPT;
3231 }
3232 }
3233
3234 static int packet_getsockopt(struct socket *sock, int level, int optname,
3235 char __user *optval, int __user *optlen)
3236 {
3237 int len;
3238 int val, lv = sizeof(val);
3239 struct sock *sk = sock->sk;
3240 struct packet_sock *po = pkt_sk(sk);
3241 void *data = &val;
3242 union tpacket_stats_u st;
3243
3244 if (level != SOL_PACKET)
3245 return -ENOPROTOOPT;
3246
3247 if (get_user(len, optlen))
3248 return -EFAULT;
3249
3250 if (len < 0)
3251 return -EINVAL;
3252
3253 switch (optname) {
3254 case PACKET_STATISTICS:
3255 spin_lock_bh(&sk->sk_receive_queue.lock);
3256 memcpy(&st, &po->stats, sizeof(st));
3257 memset(&po->stats, 0, sizeof(po->stats));
3258 spin_unlock_bh(&sk->sk_receive_queue.lock);
3259
3260 if (po->tp_version == TPACKET_V3) {
3261 lv = sizeof(struct tpacket_stats_v3);
3262 data = &st.stats3;
3263 } else {
3264 lv = sizeof(struct tpacket_stats);
3265 data = &st.stats1;
3266 }
3267
3268 break;
3269 case PACKET_AUXDATA:
3270 val = po->auxdata;
3271 break;
3272 case PACKET_ORIGDEV:
3273 val = po->origdev;
3274 break;
3275 case PACKET_VNET_HDR:
3276 val = po->has_vnet_hdr;
3277 break;
3278 case PACKET_VERSION:
3279 val = po->tp_version;
3280 break;
3281 case PACKET_HDRLEN:
3282 if (len > sizeof(int))
3283 len = sizeof(int);
3284 if (copy_from_user(&val, optval, len))
3285 return -EFAULT;
3286 switch (val) {
3287 case TPACKET_V1:
3288 val = sizeof(struct tpacket_hdr);
3289 break;
3290 case TPACKET_V2:
3291 val = sizeof(struct tpacket2_hdr);
3292 break;
3293 case TPACKET_V3:
3294 val = sizeof(struct tpacket3_hdr);
3295 break;
3296 default:
3297 return -EINVAL;
3298 }
3299 break;
3300 case PACKET_RESERVE:
3301 val = po->tp_reserve;
3302 break;
3303 case PACKET_LOSS:
3304 val = po->tp_loss;
3305 break;
3306 case PACKET_TIMESTAMP:
3307 val = po->tp_tstamp;
3308 break;
3309 case PACKET_FANOUT:
3310 val = (po->fanout ?
3311 ((u32)po->fanout->id |
3312 ((u32)po->fanout->type << 16) |
3313 ((u32)po->fanout->flags << 24)) :
3314 0);
3315 break;
3316 case PACKET_TX_HAS_OFF:
3317 val = po->tp_tx_has_off;
3318 break;
3319 default:
3320 return -ENOPROTOOPT;
3321 }
3322
3323 if (len > lv)
3324 len = lv;
3325 if (put_user(len, optlen))
3326 return -EFAULT;
3327 if (copy_to_user(optval, data, len))
3328 return -EFAULT;
3329 return 0;
3330 }
3331
3332
3333 static int packet_notifier(struct notifier_block *this,
3334 unsigned long msg, void *ptr)
3335 {
3336 struct sock *sk;
3337 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3338 struct net *net = dev_net(dev);
3339
3340 rcu_read_lock();
3341 sk_for_each_rcu(sk, &net->packet.sklist) {
3342 struct packet_sock *po = pkt_sk(sk);
3343
3344 switch (msg) {
3345 case NETDEV_UNREGISTER:
3346 if (po->mclist)
3347 packet_dev_mclist(dev, po->mclist, -1);
3348 /* fallthrough */
3349
3350 case NETDEV_DOWN:
3351 if (dev->ifindex == po->ifindex) {
3352 spin_lock(&po->bind_lock);
3353 if (po->running) {
3354 __unregister_prot_hook(sk, false);
3355 sk->sk_err = ENETDOWN;
3356 if (!sock_flag(sk, SOCK_DEAD))
3357 sk->sk_error_report(sk);
3358 }
3359 if (msg == NETDEV_UNREGISTER) {
3360 po->ifindex = -1;
3361 if (po->prot_hook.dev)
3362 dev_put(po->prot_hook.dev);
3363 po->prot_hook.dev = NULL;
3364 }
3365 spin_unlock(&po->bind_lock);
3366 }
3367 break;
3368 case NETDEV_UP:
3369 if (dev->ifindex == po->ifindex) {
3370 spin_lock(&po->bind_lock);
3371 if (po->num)
3372 register_prot_hook(sk);
3373 spin_unlock(&po->bind_lock);
3374 }
3375 break;
3376 }
3377 }
3378 rcu_read_unlock();
3379 return NOTIFY_DONE;
3380 }
3381
3382
3383 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3384 unsigned long arg)
3385 {
3386 struct sock *sk = sock->sk;
3387
3388 switch (cmd) {
3389 case SIOCOUTQ:
3390 {
3391 int amount = sk_wmem_alloc_get(sk);
3392
3393 return put_user(amount, (int __user *)arg);
3394 }
3395 case SIOCINQ:
3396 {
3397 struct sk_buff *skb;
3398 int amount = 0;
3399
3400 spin_lock_bh(&sk->sk_receive_queue.lock);
3401 skb = skb_peek(&sk->sk_receive_queue);
3402 if (skb)
3403 amount = skb->len;
3404 spin_unlock_bh(&sk->sk_receive_queue.lock);
3405 return put_user(amount, (int __user *)arg);
3406 }
3407 case SIOCGSTAMP:
3408 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3409 case SIOCGSTAMPNS:
3410 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3411
3412 #ifdef CONFIG_INET
3413 case SIOCADDRT:
3414 case SIOCDELRT:
3415 case SIOCDARP:
3416 case SIOCGARP:
3417 case SIOCSARP:
3418 case SIOCGIFADDR:
3419 case SIOCSIFADDR:
3420 case SIOCGIFBRDADDR:
3421 case SIOCSIFBRDADDR:
3422 case SIOCGIFNETMASK:
3423 case SIOCSIFNETMASK:
3424 case SIOCGIFDSTADDR:
3425 case SIOCSIFDSTADDR:
3426 case SIOCSIFFLAGS:
3427 return inet_dgram_ops.ioctl(sock, cmd, arg);
3428 #endif
3429
3430 default:
3431 return -ENOIOCTLCMD;
3432 }
3433 return 0;
3434 }
3435
3436 static unsigned int packet_poll(struct file *file, struct socket *sock,
3437 poll_table *wait)
3438 {
3439 struct sock *sk = sock->sk;
3440 struct packet_sock *po = pkt_sk(sk);
3441 unsigned int mask = datagram_poll(file, sock, wait);
3442
3443 spin_lock_bh(&sk->sk_receive_queue.lock);
3444 if (po->rx_ring.pg_vec) {
3445 if (!packet_previous_rx_frame(po, &po->rx_ring,
3446 TP_STATUS_KERNEL))
3447 mask |= POLLIN | POLLRDNORM;
3448 }
3449 spin_unlock_bh(&sk->sk_receive_queue.lock);
3450 spin_lock_bh(&sk->sk_write_queue.lock);
3451 if (po->tx_ring.pg_vec) {
3452 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3453 mask |= POLLOUT | POLLWRNORM;
3454 }
3455 spin_unlock_bh(&sk->sk_write_queue.lock);
3456 return mask;
3457 }
3458
3459
3460 /* Dirty? Well, I still did not learn better way to account
3461 * for user mmaps.
3462 */
3463
3464 static void packet_mm_open(struct vm_area_struct *vma)
3465 {
3466 struct file *file = vma->vm_file;
3467 struct socket *sock = file->private_data;
3468 struct sock *sk = sock->sk;
3469
3470 if (sk)
3471 atomic_inc(&pkt_sk(sk)->mapped);
3472 }
3473
3474 static void packet_mm_close(struct vm_area_struct *vma)
3475 {
3476 struct file *file = vma->vm_file;
3477 struct socket *sock = file->private_data;
3478 struct sock *sk = sock->sk;
3479
3480 if (sk)
3481 atomic_dec(&pkt_sk(sk)->mapped);
3482 }
3483
3484 static const struct vm_operations_struct packet_mmap_ops = {
3485 .open = packet_mm_open,
3486 .close = packet_mm_close,
3487 };
3488
3489 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3490 unsigned int len)
3491 {
3492 int i;
3493
3494 for (i = 0; i < len; i++) {
3495 if (likely(pg_vec[i].buffer)) {
3496 if (is_vmalloc_addr(pg_vec[i].buffer))
3497 vfree(pg_vec[i].buffer);
3498 else
3499 free_pages((unsigned long)pg_vec[i].buffer,
3500 order);
3501 pg_vec[i].buffer = NULL;
3502 }
3503 }
3504 kfree(pg_vec);
3505 }
3506
3507 static char *alloc_one_pg_vec_page(unsigned long order)
3508 {
3509 char *buffer = NULL;
3510 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3511 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3512
3513 buffer = (char *) __get_free_pages(gfp_flags, order);
3514
3515 if (buffer)
3516 return buffer;
3517
3518 /*
3519 * __get_free_pages failed, fall back to vmalloc
3520 */
3521 buffer = vzalloc((1 << order) * PAGE_SIZE);
3522
3523 if (buffer)
3524 return buffer;
3525
3526 /*
3527 * vmalloc failed, lets dig into swap here
3528 */
3529 gfp_flags &= ~__GFP_NORETRY;
3530 buffer = (char *)__get_free_pages(gfp_flags, order);
3531 if (buffer)
3532 return buffer;
3533
3534 /*
3535 * complete and utter failure
3536 */
3537 return NULL;
3538 }
3539
3540 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3541 {
3542 unsigned int block_nr = req->tp_block_nr;
3543 struct pgv *pg_vec;
3544 int i;
3545
3546 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3547 if (unlikely(!pg_vec))
3548 goto out;
3549
3550 for (i = 0; i < block_nr; i++) {
3551 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3552 if (unlikely(!pg_vec[i].buffer))
3553 goto out_free_pgvec;
3554 }
3555
3556 out:
3557 return pg_vec;
3558
3559 out_free_pgvec:
3560 free_pg_vec(pg_vec, order, block_nr);
3561 pg_vec = NULL;
3562 goto out;
3563 }
3564
3565 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3566 int closing, int tx_ring)
3567 {
3568 struct pgv *pg_vec = NULL;
3569 struct packet_sock *po = pkt_sk(sk);
3570 int was_running, order = 0;
3571 struct packet_ring_buffer *rb;
3572 struct sk_buff_head *rb_queue;
3573 __be16 num;
3574 int err = -EINVAL;
3575 /* Added to avoid minimal code churn */
3576 struct tpacket_req *req = &req_u->req;
3577
3578 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3579 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3580 WARN(1, "Tx-ring is not supported.\n");
3581 goto out;
3582 }
3583
3584 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3585 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3586
3587 err = -EBUSY;
3588 if (!closing) {
3589 if (atomic_read(&po->mapped))
3590 goto out;
3591 if (atomic_read(&rb->pending))
3592 goto out;
3593 }
3594
3595 if (req->tp_block_nr) {
3596 /* Sanity tests and some calculations */
3597 err = -EBUSY;
3598 if (unlikely(rb->pg_vec))
3599 goto out;
3600
3601 switch (po->tp_version) {
3602 case TPACKET_V1:
3603 po->tp_hdrlen = TPACKET_HDRLEN;
3604 break;
3605 case TPACKET_V2:
3606 po->tp_hdrlen = TPACKET2_HDRLEN;
3607 break;
3608 case TPACKET_V3:
3609 po->tp_hdrlen = TPACKET3_HDRLEN;
3610 break;
3611 }
3612
3613 err = -EINVAL;
3614 if (unlikely((int)req->tp_block_size <= 0))
3615 goto out;
3616 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3617 goto out;
3618 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3619 po->tp_reserve))
3620 goto out;
3621 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3622 goto out;
3623
3624 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3625 if (unlikely(rb->frames_per_block <= 0))
3626 goto out;
3627 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3628 req->tp_frame_nr))
3629 goto out;
3630
3631 err = -ENOMEM;
3632 order = get_order(req->tp_block_size);
3633 pg_vec = alloc_pg_vec(req, order);
3634 if (unlikely(!pg_vec))
3635 goto out;
3636 switch (po->tp_version) {
3637 case TPACKET_V3:
3638 /* Transmit path is not supported. We checked
3639 * it above but just being paranoid
3640 */
3641 if (!tx_ring)
3642 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3643 break;
3644 default:
3645 break;
3646 }
3647 }
3648 /* Done */
3649 else {
3650 err = -EINVAL;
3651 if (unlikely(req->tp_frame_nr))
3652 goto out;
3653 }
3654
3655 lock_sock(sk);
3656
3657 /* Detach socket from network */
3658 spin_lock(&po->bind_lock);
3659 was_running = po->running;
3660 num = po->num;
3661 if (was_running) {
3662 po->num = 0;
3663 __unregister_prot_hook(sk, false);
3664 }
3665 spin_unlock(&po->bind_lock);
3666
3667 synchronize_net();
3668
3669 err = -EBUSY;
3670 mutex_lock(&po->pg_vec_lock);
3671 if (closing || atomic_read(&po->mapped) == 0) {
3672 err = 0;
3673 spin_lock_bh(&rb_queue->lock);
3674 swap(rb->pg_vec, pg_vec);
3675 rb->frame_max = (req->tp_frame_nr - 1);
3676 rb->head = 0;
3677 rb->frame_size = req->tp_frame_size;
3678 spin_unlock_bh(&rb_queue->lock);
3679
3680 swap(rb->pg_vec_order, order);
3681 swap(rb->pg_vec_len, req->tp_block_nr);
3682
3683 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3684 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3685 tpacket_rcv : packet_rcv;
3686 skb_queue_purge(rb_queue);
3687 if (atomic_read(&po->mapped))
3688 pr_err("packet_mmap: vma is busy: %d\n",
3689 atomic_read(&po->mapped));
3690 }
3691 mutex_unlock(&po->pg_vec_lock);
3692
3693 spin_lock(&po->bind_lock);
3694 if (was_running) {
3695 po->num = num;
3696 register_prot_hook(sk);
3697 }
3698 spin_unlock(&po->bind_lock);
3699 if (closing && (po->tp_version > TPACKET_V2)) {
3700 /* Because we don't support block-based V3 on tx-ring */
3701 if (!tx_ring)
3702 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3703 }
3704 release_sock(sk);
3705
3706 if (pg_vec)
3707 free_pg_vec(pg_vec, order, req->tp_block_nr);
3708 out:
3709 return err;
3710 }
3711
3712 static int packet_mmap(struct file *file, struct socket *sock,
3713 struct vm_area_struct *vma)
3714 {
3715 struct sock *sk = sock->sk;
3716 struct packet_sock *po = pkt_sk(sk);
3717 unsigned long size, expected_size;
3718 struct packet_ring_buffer *rb;
3719 unsigned long start;
3720 int err = -EINVAL;
3721 int i;
3722
3723 if (vma->vm_pgoff)
3724 return -EINVAL;
3725
3726 mutex_lock(&po->pg_vec_lock);
3727
3728 expected_size = 0;
3729 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3730 if (rb->pg_vec) {
3731 expected_size += rb->pg_vec_len
3732 * rb->pg_vec_pages
3733 * PAGE_SIZE;
3734 }
3735 }
3736
3737 if (expected_size == 0)
3738 goto out;
3739
3740 size = vma->vm_end - vma->vm_start;
3741 if (size != expected_size)
3742 goto out;
3743
3744 start = vma->vm_start;
3745 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3746 if (rb->pg_vec == NULL)
3747 continue;
3748
3749 for (i = 0; i < rb->pg_vec_len; i++) {
3750 struct page *page;
3751 void *kaddr = rb->pg_vec[i].buffer;
3752 int pg_num;
3753
3754 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3755 page = pgv_to_page(kaddr);
3756 err = vm_insert_page(vma, start, page);
3757 if (unlikely(err))
3758 goto out;
3759 start += PAGE_SIZE;
3760 kaddr += PAGE_SIZE;
3761 }
3762 }
3763 }
3764
3765 atomic_inc(&po->mapped);
3766 vma->vm_ops = &packet_mmap_ops;
3767 err = 0;
3768
3769 out:
3770 mutex_unlock(&po->pg_vec_lock);
3771 return err;
3772 }
3773
3774 static const struct proto_ops packet_ops_spkt = {
3775 .family = PF_PACKET,
3776 .owner = THIS_MODULE,
3777 .release = packet_release,
3778 .bind = packet_bind_spkt,
3779 .connect = sock_no_connect,
3780 .socketpair = sock_no_socketpair,
3781 .accept = sock_no_accept,
3782 .getname = packet_getname_spkt,
3783 .poll = datagram_poll,
3784 .ioctl = packet_ioctl,
3785 .listen = sock_no_listen,
3786 .shutdown = sock_no_shutdown,
3787 .setsockopt = sock_no_setsockopt,
3788 .getsockopt = sock_no_getsockopt,
3789 .sendmsg = packet_sendmsg_spkt,
3790 .recvmsg = packet_recvmsg,
3791 .mmap = sock_no_mmap,
3792 .sendpage = sock_no_sendpage,
3793 };
3794
3795 static const struct proto_ops packet_ops = {
3796 .family = PF_PACKET,
3797 .owner = THIS_MODULE,
3798 .release = packet_release,
3799 .bind = packet_bind,
3800 .connect = sock_no_connect,
3801 .socketpair = sock_no_socketpair,
3802 .accept = sock_no_accept,
3803 .getname = packet_getname,
3804 .poll = packet_poll,
3805 .ioctl = packet_ioctl,
3806 .listen = sock_no_listen,
3807 .shutdown = sock_no_shutdown,
3808 .setsockopt = packet_setsockopt,
3809 .getsockopt = packet_getsockopt,
3810 .sendmsg = packet_sendmsg,
3811 .recvmsg = packet_recvmsg,
3812 .mmap = packet_mmap,
3813 .sendpage = sock_no_sendpage,
3814 };
3815
3816 static const struct net_proto_family packet_family_ops = {
3817 .family = PF_PACKET,
3818 .create = packet_create,
3819 .owner = THIS_MODULE,
3820 };
3821
3822 static struct notifier_block packet_netdev_notifier = {
3823 .notifier_call = packet_notifier,
3824 };
3825
3826 #ifdef CONFIG_PROC_FS
3827
3828 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3829 __acquires(RCU)
3830 {
3831 struct net *net = seq_file_net(seq);
3832
3833 rcu_read_lock();
3834 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3835 }
3836
3837 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3838 {
3839 struct net *net = seq_file_net(seq);
3840 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3841 }
3842
3843 static void packet_seq_stop(struct seq_file *seq, void *v)
3844 __releases(RCU)
3845 {
3846 rcu_read_unlock();
3847 }
3848
3849 static int packet_seq_show(struct seq_file *seq, void *v)
3850 {
3851 if (v == SEQ_START_TOKEN)
3852 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3853 else {
3854 struct sock *s = sk_entry(v);
3855 const struct packet_sock *po = pkt_sk(s);
3856
3857 seq_printf(seq,
3858 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3859 s,
3860 atomic_read(&s->sk_refcnt),
3861 s->sk_type,
3862 ntohs(po->num),
3863 po->ifindex,
3864 po->running,
3865 atomic_read(&s->sk_rmem_alloc),
3866 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3867 sock_i_ino(s));
3868 }
3869
3870 return 0;
3871 }
3872
3873 static const struct seq_operations packet_seq_ops = {
3874 .start = packet_seq_start,
3875 .next = packet_seq_next,
3876 .stop = packet_seq_stop,
3877 .show = packet_seq_show,
3878 };
3879
3880 static int packet_seq_open(struct inode *inode, struct file *file)
3881 {
3882 return seq_open_net(inode, file, &packet_seq_ops,
3883 sizeof(struct seq_net_private));
3884 }
3885
3886 static const struct file_operations packet_seq_fops = {
3887 .owner = THIS_MODULE,
3888 .open = packet_seq_open,
3889 .read = seq_read,
3890 .llseek = seq_lseek,
3891 .release = seq_release_net,
3892 };
3893
3894 #endif
3895
3896 static int __net_init packet_net_init(struct net *net)
3897 {
3898 mutex_init(&net->packet.sklist_lock);
3899 INIT_HLIST_HEAD(&net->packet.sklist);
3900
3901 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
3902 return -ENOMEM;
3903
3904 return 0;
3905 }
3906
3907 static void __net_exit packet_net_exit(struct net *net)
3908 {
3909 remove_proc_entry("packet", net->proc_net);
3910 }
3911
3912 static struct pernet_operations packet_net_ops = {
3913 .init = packet_net_init,
3914 .exit = packet_net_exit,
3915 };
3916
3917
3918 static void __exit packet_exit(void)
3919 {
3920 unregister_netdevice_notifier(&packet_netdev_notifier);
3921 unregister_pernet_subsys(&packet_net_ops);
3922 sock_unregister(PF_PACKET);
3923 proto_unregister(&packet_proto);
3924 }
3925
3926 static int __init packet_init(void)
3927 {
3928 int rc = proto_register(&packet_proto, 0);
3929
3930 if (rc != 0)
3931 goto out;
3932
3933 sock_register(&packet_family_ops);
3934 register_pernet_subsys(&packet_net_ops);
3935 register_netdevice_notifier(&packet_netdev_notifier);
3936 out:
3937 return rc;
3938 }
3939
3940 module_init(packet_init);
3941 module_exit(packet_exit);
3942 MODULE_LICENSE("GPL");
3943 MODULE_ALIAS_NETPROTO(PF_PACKET);
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