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packet: fix use after free race in send path when dev is released
[deliverable/linux.git] / net / packet / af_packet.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PACKET - implements raw packet sockets.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 *
12 * Fixes:
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
41 * and packet_mreq.
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
44 * layer.
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
46 *
47 *
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
52 *
53 */
54
55 #include <linux/types.h>
56 #include <linux/mm.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
60 #include <linux/in.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
70 #include <net/ip.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
73 #include <net/sock.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <asm/uaccess.h>
77 #include <asm/ioctls.h>
78 #include <asm/page.h>
79 #include <asm/cacheflush.h>
80 #include <asm/io.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91 #include <linux/reciprocal_div.h>
92 #ifdef CONFIG_INET
93 #include <net/inet_common.h>
94 #endif
95
96 #include "internal.h"
97
98 /*
99 Assumptions:
100 - if device has no dev->hard_header routine, it adds and removes ll header
101 inside itself. In this case ll header is invisible outside of device,
102 but higher levels still should reserve dev->hard_header_len.
103 Some devices are enough clever to reallocate skb, when header
104 will not fit to reserved space (tunnel), another ones are silly
105 (PPP).
106 - packet socket receives packets with pulled ll header,
107 so that SOCK_RAW should push it back.
108
109 On receive:
110 -----------
111
112 Incoming, dev->hard_header!=NULL
113 mac_header -> ll header
114 data -> data
115
116 Outgoing, dev->hard_header!=NULL
117 mac_header -> ll header
118 data -> ll header
119
120 Incoming, dev->hard_header==NULL
121 mac_header -> UNKNOWN position. It is very likely, that it points to ll
122 header. PPP makes it, that is wrong, because introduce
123 assymetry between rx and tx paths.
124 data -> data
125
126 Outgoing, dev->hard_header==NULL
127 mac_header -> data. ll header is still not built!
128 data -> data
129
130 Resume
131 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
132
133
134 On transmit:
135 ------------
136
137 dev->hard_header != NULL
138 mac_header -> ll header
139 data -> ll header
140
141 dev->hard_header == NULL (ll header is added by device, we cannot control it)
142 mac_header -> data
143 data -> data
144
145 We should set nh.raw on output to correct posistion,
146 packet classifier depends on it.
147 */
148
149 /* Private packet socket structures. */
150
151 /* identical to struct packet_mreq except it has
152 * a longer address field.
153 */
154 struct packet_mreq_max {
155 int mr_ifindex;
156 unsigned short mr_type;
157 unsigned short mr_alen;
158 unsigned char mr_address[MAX_ADDR_LEN];
159 };
160
161 union tpacket_uhdr {
162 struct tpacket_hdr *h1;
163 struct tpacket2_hdr *h2;
164 struct tpacket3_hdr *h3;
165 void *raw;
166 };
167
168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
169 int closing, int tx_ring);
170
171 #define V3_ALIGNMENT (8)
172
173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
174
175 #define BLK_PLUS_PRIV(sz_of_priv) \
176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
177
178 #define PGV_FROM_VMALLOC 1
179
180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
187
188 struct packet_sock;
189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
191 struct packet_type *pt, struct net_device *orig_dev);
192
193 static void *packet_previous_frame(struct packet_sock *po,
194 struct packet_ring_buffer *rb,
195 int status);
196 static void packet_increment_head(struct packet_ring_buffer *buff);
197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
198 struct tpacket_block_desc *);
199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200 struct packet_sock *);
201 static void prb_retire_current_block(struct tpacket_kbdq_core *,
202 struct packet_sock *, unsigned int status);
203 static int prb_queue_frozen(struct tpacket_kbdq_core *);
204 static void prb_open_block(struct tpacket_kbdq_core *,
205 struct tpacket_block_desc *);
206 static void prb_retire_rx_blk_timer_expired(unsigned long);
207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208 static void prb_init_blk_timer(struct packet_sock *,
209 struct tpacket_kbdq_core *,
210 void (*func) (unsigned long));
211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
212 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
213 struct tpacket3_hdr *);
214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
215 struct tpacket3_hdr *);
216 static void packet_flush_mclist(struct sock *sk);
217
218 struct packet_skb_cb {
219 unsigned int origlen;
220 union {
221 struct sockaddr_pkt pkt;
222 struct sockaddr_ll ll;
223 } sa;
224 };
225
226 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
227
228 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
229 #define GET_PBLOCK_DESC(x, bid) \
230 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
232 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
233 #define GET_NEXT_PRB_BLK_NUM(x) \
234 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
235 ((x)->kactive_blk_num+1) : 0)
236
237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
238 static void __fanout_link(struct sock *sk, struct packet_sock *po);
239
240 /* 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
248 if (!po->running) {
249 if (po->fanout) {
250 __fanout_link(sk, po);
251 } else {
252 dev_add_pack(&po->prot_hook);
253 rcu_assign_pointer(po->cached_dev, po->prot_hook.dev);
254 }
255
256 sock_hold(sk);
257 po->running = 1;
258 }
259 }
260
261 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
262 * held. If the sync parameter is true, we will temporarily drop
263 * the po->bind_lock and do a synchronize_net to make sure no
264 * asynchronous packet processing paths still refer to the elements
265 * of po->prot_hook. If the sync parameter is false, it is the
266 * callers responsibility to take care of this.
267 */
268 static void __unregister_prot_hook(struct sock *sk, bool sync)
269 {
270 struct packet_sock *po = pkt_sk(sk);
271
272 po->running = 0;
273 if (po->fanout) {
274 __fanout_unlink(sk, po);
275 } else {
276 __dev_remove_pack(&po->prot_hook);
277 RCU_INIT_POINTER(po->cached_dev, NULL);
278 }
279
280 __sock_put(sk);
281
282 if (sync) {
283 spin_unlock(&po->bind_lock);
284 synchronize_net();
285 spin_lock(&po->bind_lock);
286 }
287 }
288
289 static void unregister_prot_hook(struct sock *sk, bool sync)
290 {
291 struct packet_sock *po = pkt_sk(sk);
292
293 if (po->running)
294 __unregister_prot_hook(sk, sync);
295 }
296
297 static inline __pure struct page *pgv_to_page(void *addr)
298 {
299 if (is_vmalloc_addr(addr))
300 return vmalloc_to_page(addr);
301 return virt_to_page(addr);
302 }
303
304 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
305 {
306 union tpacket_uhdr h;
307
308 h.raw = frame;
309 switch (po->tp_version) {
310 case TPACKET_V1:
311 h.h1->tp_status = status;
312 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
313 break;
314 case TPACKET_V2:
315 h.h2->tp_status = status;
316 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
317 break;
318 case TPACKET_V3:
319 default:
320 WARN(1, "TPACKET version not supported.\n");
321 BUG();
322 }
323
324 smp_wmb();
325 }
326
327 static int __packet_get_status(struct packet_sock *po, void *frame)
328 {
329 union tpacket_uhdr h;
330
331 smp_rmb();
332
333 h.raw = frame;
334 switch (po->tp_version) {
335 case TPACKET_V1:
336 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
337 return h.h1->tp_status;
338 case TPACKET_V2:
339 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
340 return h.h2->tp_status;
341 case TPACKET_V3:
342 default:
343 WARN(1, "TPACKET version not supported.\n");
344 BUG();
345 return 0;
346 }
347 }
348
349 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
350 unsigned int flags)
351 {
352 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
353
354 if (shhwtstamps) {
355 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
356 ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
357 return TP_STATUS_TS_SYS_HARDWARE;
358 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
359 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
360 return TP_STATUS_TS_RAW_HARDWARE;
361 }
362
363 if (ktime_to_timespec_cond(skb->tstamp, ts))
364 return TP_STATUS_TS_SOFTWARE;
365
366 return 0;
367 }
368
369 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
370 struct sk_buff *skb)
371 {
372 union tpacket_uhdr h;
373 struct timespec ts;
374 __u32 ts_status;
375
376 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
377 return 0;
378
379 h.raw = frame;
380 switch (po->tp_version) {
381 case TPACKET_V1:
382 h.h1->tp_sec = ts.tv_sec;
383 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
384 break;
385 case TPACKET_V2:
386 h.h2->tp_sec = ts.tv_sec;
387 h.h2->tp_nsec = ts.tv_nsec;
388 break;
389 case TPACKET_V3:
390 default:
391 WARN(1, "TPACKET version not supported.\n");
392 BUG();
393 }
394
395 /* one flush is safe, as both fields always lie on the same cacheline */
396 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
397 smp_wmb();
398
399 return ts_status;
400 }
401
402 static void *packet_lookup_frame(struct packet_sock *po,
403 struct packet_ring_buffer *rb,
404 unsigned int position,
405 int status)
406 {
407 unsigned int pg_vec_pos, frame_offset;
408 union tpacket_uhdr h;
409
410 pg_vec_pos = position / rb->frames_per_block;
411 frame_offset = position % rb->frames_per_block;
412
413 h.raw = rb->pg_vec[pg_vec_pos].buffer +
414 (frame_offset * rb->frame_size);
415
416 if (status != __packet_get_status(po, h.raw))
417 return NULL;
418
419 return h.raw;
420 }
421
422 static void *packet_current_frame(struct packet_sock *po,
423 struct packet_ring_buffer *rb,
424 int status)
425 {
426 return packet_lookup_frame(po, rb, rb->head, status);
427 }
428
429 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
430 {
431 del_timer_sync(&pkc->retire_blk_timer);
432 }
433
434 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
435 int tx_ring,
436 struct sk_buff_head *rb_queue)
437 {
438 struct tpacket_kbdq_core *pkc;
439
440 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
441
442 spin_lock(&rb_queue->lock);
443 pkc->delete_blk_timer = 1;
444 spin_unlock(&rb_queue->lock);
445
446 prb_del_retire_blk_timer(pkc);
447 }
448
449 static void prb_init_blk_timer(struct packet_sock *po,
450 struct tpacket_kbdq_core *pkc,
451 void (*func) (unsigned long))
452 {
453 init_timer(&pkc->retire_blk_timer);
454 pkc->retire_blk_timer.data = (long)po;
455 pkc->retire_blk_timer.function = func;
456 pkc->retire_blk_timer.expires = jiffies;
457 }
458
459 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
460 {
461 struct tpacket_kbdq_core *pkc;
462
463 if (tx_ring)
464 BUG();
465
466 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
467 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
468 }
469
470 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
471 int blk_size_in_bytes)
472 {
473 struct net_device *dev;
474 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
475 struct ethtool_cmd ecmd;
476 int err;
477 u32 speed;
478
479 rtnl_lock();
480 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
481 if (unlikely(!dev)) {
482 rtnl_unlock();
483 return DEFAULT_PRB_RETIRE_TOV;
484 }
485 err = __ethtool_get_settings(dev, &ecmd);
486 speed = ethtool_cmd_speed(&ecmd);
487 rtnl_unlock();
488 if (!err) {
489 /*
490 * If the link speed is so slow you don't really
491 * need to worry about perf anyways
492 */
493 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
494 return DEFAULT_PRB_RETIRE_TOV;
495 } else {
496 msec = 1;
497 div = speed / 1000;
498 }
499 }
500
501 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
502
503 if (div)
504 mbits /= div;
505
506 tmo = mbits * msec;
507
508 if (div)
509 return tmo+1;
510 return tmo;
511 }
512
513 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
514 union tpacket_req_u *req_u)
515 {
516 p1->feature_req_word = req_u->req3.tp_feature_req_word;
517 }
518
519 static void init_prb_bdqc(struct packet_sock *po,
520 struct packet_ring_buffer *rb,
521 struct pgv *pg_vec,
522 union tpacket_req_u *req_u, int tx_ring)
523 {
524 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
525 struct tpacket_block_desc *pbd;
526
527 memset(p1, 0x0, sizeof(*p1));
528
529 p1->knxt_seq_num = 1;
530 p1->pkbdq = pg_vec;
531 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
532 p1->pkblk_start = pg_vec[0].buffer;
533 p1->kblk_size = req_u->req3.tp_block_size;
534 p1->knum_blocks = req_u->req3.tp_block_nr;
535 p1->hdrlen = po->tp_hdrlen;
536 p1->version = po->tp_version;
537 p1->last_kactive_blk_num = 0;
538 po->stats.stats3.tp_freeze_q_cnt = 0;
539 if (req_u->req3.tp_retire_blk_tov)
540 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
541 else
542 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
543 req_u->req3.tp_block_size);
544 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
545 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
546
547 prb_init_ft_ops(p1, req_u);
548 prb_setup_retire_blk_timer(po, tx_ring);
549 prb_open_block(p1, pbd);
550 }
551
552 /* Do NOT update the last_blk_num first.
553 * Assumes sk_buff_head lock is held.
554 */
555 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
556 {
557 mod_timer(&pkc->retire_blk_timer,
558 jiffies + pkc->tov_in_jiffies);
559 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
560 }
561
562 /*
563 * Timer logic:
564 * 1) We refresh the timer only when we open a block.
565 * By doing this we don't waste cycles refreshing the timer
566 * on packet-by-packet basis.
567 *
568 * With a 1MB block-size, on a 1Gbps line, it will take
569 * i) ~8 ms to fill a block + ii) memcpy etc.
570 * In this cut we are not accounting for the memcpy time.
571 *
572 * So, if the user sets the 'tmo' to 10ms then the timer
573 * will never fire while the block is still getting filled
574 * (which is what we want). However, the user could choose
575 * to close a block early and that's fine.
576 *
577 * But when the timer does fire, we check whether or not to refresh it.
578 * Since the tmo granularity is in msecs, it is not too expensive
579 * to refresh the timer, lets say every '8' msecs.
580 * Either the user can set the 'tmo' or we can derive it based on
581 * a) line-speed and b) block-size.
582 * prb_calc_retire_blk_tmo() calculates the tmo.
583 *
584 */
585 static void prb_retire_rx_blk_timer_expired(unsigned long data)
586 {
587 struct packet_sock *po = (struct packet_sock *)data;
588 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
589 unsigned int frozen;
590 struct tpacket_block_desc *pbd;
591
592 spin_lock(&po->sk.sk_receive_queue.lock);
593
594 frozen = prb_queue_frozen(pkc);
595 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
596
597 if (unlikely(pkc->delete_blk_timer))
598 goto out;
599
600 /* We only need to plug the race when the block is partially filled.
601 * tpacket_rcv:
602 * lock(); increment BLOCK_NUM_PKTS; unlock()
603 * copy_bits() is in progress ...
604 * timer fires on other cpu:
605 * we can't retire the current block because copy_bits
606 * is in progress.
607 *
608 */
609 if (BLOCK_NUM_PKTS(pbd)) {
610 while (atomic_read(&pkc->blk_fill_in_prog)) {
611 /* Waiting for skb_copy_bits to finish... */
612 cpu_relax();
613 }
614 }
615
616 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
617 if (!frozen) {
618 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
619 if (!prb_dispatch_next_block(pkc, po))
620 goto refresh_timer;
621 else
622 goto out;
623 } else {
624 /* Case 1. Queue was frozen because user-space was
625 * lagging behind.
626 */
627 if (prb_curr_blk_in_use(pkc, pbd)) {
628 /*
629 * Ok, user-space is still behind.
630 * So just refresh the timer.
631 */
632 goto refresh_timer;
633 } else {
634 /* Case 2. queue was frozen,user-space caught up,
635 * now the link went idle && the timer fired.
636 * We don't have a block to close.So we open this
637 * block and restart the timer.
638 * opening a block thaws the queue,restarts timer
639 * Thawing/timer-refresh is a side effect.
640 */
641 prb_open_block(pkc, pbd);
642 goto out;
643 }
644 }
645 }
646
647 refresh_timer:
648 _prb_refresh_rx_retire_blk_timer(pkc);
649
650 out:
651 spin_unlock(&po->sk.sk_receive_queue.lock);
652 }
653
654 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
655 struct tpacket_block_desc *pbd1, __u32 status)
656 {
657 /* Flush everything minus the block header */
658
659 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
660 u8 *start, *end;
661
662 start = (u8 *)pbd1;
663
664 /* Skip the block header(we know header WILL fit in 4K) */
665 start += PAGE_SIZE;
666
667 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
668 for (; start < end; start += PAGE_SIZE)
669 flush_dcache_page(pgv_to_page(start));
670
671 smp_wmb();
672 #endif
673
674 /* Now update the block status. */
675
676 BLOCK_STATUS(pbd1) = status;
677
678 /* Flush the block header */
679
680 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
681 start = (u8 *)pbd1;
682 flush_dcache_page(pgv_to_page(start));
683
684 smp_wmb();
685 #endif
686 }
687
688 /*
689 * Side effect:
690 *
691 * 1) flush the block
692 * 2) Increment active_blk_num
693 *
694 * Note:We DONT refresh the timer on purpose.
695 * Because almost always the next block will be opened.
696 */
697 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
698 struct tpacket_block_desc *pbd1,
699 struct packet_sock *po, unsigned int stat)
700 {
701 __u32 status = TP_STATUS_USER | stat;
702
703 struct tpacket3_hdr *last_pkt;
704 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
705
706 if (po->stats.stats3.tp_drops)
707 status |= TP_STATUS_LOSING;
708
709 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
710 last_pkt->tp_next_offset = 0;
711
712 /* Get the ts of the last pkt */
713 if (BLOCK_NUM_PKTS(pbd1)) {
714 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
715 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
716 } else {
717 /* Ok, we tmo'd - so get the current time */
718 struct timespec ts;
719 getnstimeofday(&ts);
720 h1->ts_last_pkt.ts_sec = ts.tv_sec;
721 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
722 }
723
724 smp_wmb();
725
726 /* Flush the block */
727 prb_flush_block(pkc1, pbd1, status);
728
729 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
730 }
731
732 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
733 {
734 pkc->reset_pending_on_curr_blk = 0;
735 }
736
737 /*
738 * Side effect of opening a block:
739 *
740 * 1) prb_queue is thawed.
741 * 2) retire_blk_timer is refreshed.
742 *
743 */
744 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
745 struct tpacket_block_desc *pbd1)
746 {
747 struct timespec ts;
748 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
749
750 smp_rmb();
751
752 /* We could have just memset this but we will lose the
753 * flexibility of making the priv area sticky
754 */
755
756 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
757 BLOCK_NUM_PKTS(pbd1) = 0;
758 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
759
760 getnstimeofday(&ts);
761
762 h1->ts_first_pkt.ts_sec = ts.tv_sec;
763 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
764
765 pkc1->pkblk_start = (char *)pbd1;
766 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
767
768 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
769 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
770
771 pbd1->version = pkc1->version;
772 pkc1->prev = pkc1->nxt_offset;
773 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
774
775 prb_thaw_queue(pkc1);
776 _prb_refresh_rx_retire_blk_timer(pkc1);
777
778 smp_wmb();
779 }
780
781 /*
782 * Queue freeze logic:
783 * 1) Assume tp_block_nr = 8 blocks.
784 * 2) At time 't0', user opens Rx ring.
785 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
786 * 4) user-space is either sleeping or processing block '0'.
787 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
788 * it will close block-7,loop around and try to fill block '0'.
789 * call-flow:
790 * __packet_lookup_frame_in_block
791 * prb_retire_current_block()
792 * prb_dispatch_next_block()
793 * |->(BLOCK_STATUS == USER) evaluates to true
794 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
795 * 6) Now there are two cases:
796 * 6.1) Link goes idle right after the queue is frozen.
797 * But remember, the last open_block() refreshed the timer.
798 * When this timer expires,it will refresh itself so that we can
799 * re-open block-0 in near future.
800 * 6.2) Link is busy and keeps on receiving packets. This is a simple
801 * case and __packet_lookup_frame_in_block will check if block-0
802 * is free and can now be re-used.
803 */
804 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
805 struct packet_sock *po)
806 {
807 pkc->reset_pending_on_curr_blk = 1;
808 po->stats.stats3.tp_freeze_q_cnt++;
809 }
810
811 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
812
813 /*
814 * If the next block is free then we will dispatch it
815 * and return a good offset.
816 * Else, we will freeze the queue.
817 * So, caller must check the return value.
818 */
819 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
820 struct packet_sock *po)
821 {
822 struct tpacket_block_desc *pbd;
823
824 smp_rmb();
825
826 /* 1. Get current block num */
827 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
828
829 /* 2. If this block is currently in_use then freeze the queue */
830 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
831 prb_freeze_queue(pkc, po);
832 return NULL;
833 }
834
835 /*
836 * 3.
837 * open this block and return the offset where the first packet
838 * needs to get stored.
839 */
840 prb_open_block(pkc, pbd);
841 return (void *)pkc->nxt_offset;
842 }
843
844 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
845 struct packet_sock *po, unsigned int status)
846 {
847 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
848
849 /* retire/close the current block */
850 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
851 /*
852 * Plug the case where copy_bits() is in progress on
853 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
854 * have space to copy the pkt in the current block and
855 * called prb_retire_current_block()
856 *
857 * We don't need to worry about the TMO case because
858 * the timer-handler already handled this case.
859 */
860 if (!(status & TP_STATUS_BLK_TMO)) {
861 while (atomic_read(&pkc->blk_fill_in_prog)) {
862 /* Waiting for skb_copy_bits to finish... */
863 cpu_relax();
864 }
865 }
866 prb_close_block(pkc, pbd, po, status);
867 return;
868 }
869 }
870
871 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
872 struct tpacket_block_desc *pbd)
873 {
874 return TP_STATUS_USER & BLOCK_STATUS(pbd);
875 }
876
877 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
878 {
879 return pkc->reset_pending_on_curr_blk;
880 }
881
882 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
883 {
884 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
885 atomic_dec(&pkc->blk_fill_in_prog);
886 }
887
888 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
889 struct tpacket3_hdr *ppd)
890 {
891 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
892 }
893
894 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
895 struct tpacket3_hdr *ppd)
896 {
897 ppd->hv1.tp_rxhash = 0;
898 }
899
900 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
901 struct tpacket3_hdr *ppd)
902 {
903 if (vlan_tx_tag_present(pkc->skb)) {
904 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
905 ppd->tp_status = TP_STATUS_VLAN_VALID;
906 } else {
907 ppd->hv1.tp_vlan_tci = 0;
908 ppd->tp_status = TP_STATUS_AVAILABLE;
909 }
910 }
911
912 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
913 struct tpacket3_hdr *ppd)
914 {
915 prb_fill_vlan_info(pkc, ppd);
916
917 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
918 prb_fill_rxhash(pkc, ppd);
919 else
920 prb_clear_rxhash(pkc, ppd);
921 }
922
923 static void prb_fill_curr_block(char *curr,
924 struct tpacket_kbdq_core *pkc,
925 struct tpacket_block_desc *pbd,
926 unsigned int len)
927 {
928 struct tpacket3_hdr *ppd;
929
930 ppd = (struct tpacket3_hdr *)curr;
931 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
932 pkc->prev = curr;
933 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
934 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
935 BLOCK_NUM_PKTS(pbd) += 1;
936 atomic_inc(&pkc->blk_fill_in_prog);
937 prb_run_all_ft_ops(pkc, ppd);
938 }
939
940 /* Assumes caller has the sk->rx_queue.lock */
941 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
942 struct sk_buff *skb,
943 int status,
944 unsigned int len
945 )
946 {
947 struct tpacket_kbdq_core *pkc;
948 struct tpacket_block_desc *pbd;
949 char *curr, *end;
950
951 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
952 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
953
954 /* Queue is frozen when user space is lagging behind */
955 if (prb_queue_frozen(pkc)) {
956 /*
957 * Check if that last block which caused the queue to freeze,
958 * is still in_use by user-space.
959 */
960 if (prb_curr_blk_in_use(pkc, pbd)) {
961 /* Can't record this packet */
962 return NULL;
963 } else {
964 /*
965 * Ok, the block was released by user-space.
966 * Now let's open that block.
967 * opening a block also thaws the queue.
968 * Thawing is a side effect.
969 */
970 prb_open_block(pkc, pbd);
971 }
972 }
973
974 smp_mb();
975 curr = pkc->nxt_offset;
976 pkc->skb = skb;
977 end = (char *)pbd + pkc->kblk_size;
978
979 /* first try the current block */
980 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
981 prb_fill_curr_block(curr, pkc, pbd, len);
982 return (void *)curr;
983 }
984
985 /* Ok, close the current block */
986 prb_retire_current_block(pkc, po, 0);
987
988 /* Now, try to dispatch the next block */
989 curr = (char *)prb_dispatch_next_block(pkc, po);
990 if (curr) {
991 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
992 prb_fill_curr_block(curr, pkc, pbd, len);
993 return (void *)curr;
994 }
995
996 /*
997 * No free blocks are available.user_space hasn't caught up yet.
998 * Queue was just frozen and now this packet will get dropped.
999 */
1000 return NULL;
1001 }
1002
1003 static void *packet_current_rx_frame(struct packet_sock *po,
1004 struct sk_buff *skb,
1005 int status, unsigned int len)
1006 {
1007 char *curr = NULL;
1008 switch (po->tp_version) {
1009 case TPACKET_V1:
1010 case TPACKET_V2:
1011 curr = packet_lookup_frame(po, &po->rx_ring,
1012 po->rx_ring.head, status);
1013 return curr;
1014 case TPACKET_V3:
1015 return __packet_lookup_frame_in_block(po, skb, status, len);
1016 default:
1017 WARN(1, "TPACKET version not supported\n");
1018 BUG();
1019 return NULL;
1020 }
1021 }
1022
1023 static void *prb_lookup_block(struct packet_sock *po,
1024 struct packet_ring_buffer *rb,
1025 unsigned int idx,
1026 int status)
1027 {
1028 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1029 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1030
1031 if (status != BLOCK_STATUS(pbd))
1032 return NULL;
1033 return pbd;
1034 }
1035
1036 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1037 {
1038 unsigned int prev;
1039 if (rb->prb_bdqc.kactive_blk_num)
1040 prev = rb->prb_bdqc.kactive_blk_num-1;
1041 else
1042 prev = rb->prb_bdqc.knum_blocks-1;
1043 return prev;
1044 }
1045
1046 /* Assumes caller has held the rx_queue.lock */
1047 static void *__prb_previous_block(struct packet_sock *po,
1048 struct packet_ring_buffer *rb,
1049 int status)
1050 {
1051 unsigned int previous = prb_previous_blk_num(rb);
1052 return prb_lookup_block(po, rb, previous, status);
1053 }
1054
1055 static void *packet_previous_rx_frame(struct packet_sock *po,
1056 struct packet_ring_buffer *rb,
1057 int status)
1058 {
1059 if (po->tp_version <= TPACKET_V2)
1060 return packet_previous_frame(po, rb, status);
1061
1062 return __prb_previous_block(po, rb, status);
1063 }
1064
1065 static void packet_increment_rx_head(struct packet_sock *po,
1066 struct packet_ring_buffer *rb)
1067 {
1068 switch (po->tp_version) {
1069 case TPACKET_V1:
1070 case TPACKET_V2:
1071 return packet_increment_head(rb);
1072 case TPACKET_V3:
1073 default:
1074 WARN(1, "TPACKET version not supported.\n");
1075 BUG();
1076 return;
1077 }
1078 }
1079
1080 static void *packet_previous_frame(struct packet_sock *po,
1081 struct packet_ring_buffer *rb,
1082 int status)
1083 {
1084 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1085 return packet_lookup_frame(po, rb, previous, status);
1086 }
1087
1088 static void packet_increment_head(struct packet_ring_buffer *buff)
1089 {
1090 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1091 }
1092
1093 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1094 {
1095 struct sock *sk = &po->sk;
1096 bool has_room;
1097
1098 if (po->prot_hook.func != tpacket_rcv)
1099 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
1100 <= sk->sk_rcvbuf;
1101
1102 spin_lock(&sk->sk_receive_queue.lock);
1103 if (po->tp_version == TPACKET_V3)
1104 has_room = prb_lookup_block(po, &po->rx_ring,
1105 po->rx_ring.prb_bdqc.kactive_blk_num,
1106 TP_STATUS_KERNEL);
1107 else
1108 has_room = packet_lookup_frame(po, &po->rx_ring,
1109 po->rx_ring.head,
1110 TP_STATUS_KERNEL);
1111 spin_unlock(&sk->sk_receive_queue.lock);
1112
1113 return has_room;
1114 }
1115
1116 static void packet_sock_destruct(struct sock *sk)
1117 {
1118 skb_queue_purge(&sk->sk_error_queue);
1119
1120 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1121 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1122
1123 if (!sock_flag(sk, SOCK_DEAD)) {
1124 pr_err("Attempt to release alive packet socket: %p\n", sk);
1125 return;
1126 }
1127
1128 sk_refcnt_debug_dec(sk);
1129 }
1130
1131 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1132 {
1133 int x = atomic_read(&f->rr_cur) + 1;
1134
1135 if (x >= num)
1136 x = 0;
1137
1138 return x;
1139 }
1140
1141 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1142 struct sk_buff *skb,
1143 unsigned int num)
1144 {
1145 return reciprocal_divide(skb->rxhash, num);
1146 }
1147
1148 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1149 struct sk_buff *skb,
1150 unsigned int num)
1151 {
1152 int cur, old;
1153
1154 cur = atomic_read(&f->rr_cur);
1155 while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1156 fanout_rr_next(f, num))) != cur)
1157 cur = old;
1158 return cur;
1159 }
1160
1161 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1162 struct sk_buff *skb,
1163 unsigned int num)
1164 {
1165 return smp_processor_id() % num;
1166 }
1167
1168 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1169 struct sk_buff *skb,
1170 unsigned int num)
1171 {
1172 return reciprocal_divide(prandom_u32(), num);
1173 }
1174
1175 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1176 struct sk_buff *skb,
1177 unsigned int idx, unsigned int skip,
1178 unsigned int num)
1179 {
1180 unsigned int i, j;
1181
1182 i = j = min_t(int, f->next[idx], num - 1);
1183 do {
1184 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1185 if (i != j)
1186 f->next[idx] = i;
1187 return i;
1188 }
1189 if (++i == num)
1190 i = 0;
1191 } while (i != j);
1192
1193 return idx;
1194 }
1195
1196 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1197 {
1198 return f->flags & (flag >> 8);
1199 }
1200
1201 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1202 struct packet_type *pt, struct net_device *orig_dev)
1203 {
1204 struct packet_fanout *f = pt->af_packet_priv;
1205 unsigned int num = f->num_members;
1206 struct packet_sock *po;
1207 unsigned int idx;
1208
1209 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1210 !num) {
1211 kfree_skb(skb);
1212 return 0;
1213 }
1214
1215 switch (f->type) {
1216 case PACKET_FANOUT_HASH:
1217 default:
1218 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1219 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1220 if (!skb)
1221 return 0;
1222 }
1223 skb_get_rxhash(skb);
1224 idx = fanout_demux_hash(f, skb, num);
1225 break;
1226 case PACKET_FANOUT_LB:
1227 idx = fanout_demux_lb(f, skb, num);
1228 break;
1229 case PACKET_FANOUT_CPU:
1230 idx = fanout_demux_cpu(f, skb, num);
1231 break;
1232 case PACKET_FANOUT_RND:
1233 idx = fanout_demux_rnd(f, skb, num);
1234 break;
1235 case PACKET_FANOUT_ROLLOVER:
1236 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1237 break;
1238 }
1239
1240 po = pkt_sk(f->arr[idx]);
1241 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1242 unlikely(!packet_rcv_has_room(po, skb))) {
1243 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1244 po = pkt_sk(f->arr[idx]);
1245 }
1246
1247 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1248 }
1249
1250 DEFINE_MUTEX(fanout_mutex);
1251 EXPORT_SYMBOL_GPL(fanout_mutex);
1252 static LIST_HEAD(fanout_list);
1253
1254 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1255 {
1256 struct packet_fanout *f = po->fanout;
1257
1258 spin_lock(&f->lock);
1259 f->arr[f->num_members] = sk;
1260 smp_wmb();
1261 f->num_members++;
1262 spin_unlock(&f->lock);
1263 }
1264
1265 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1266 {
1267 struct packet_fanout *f = po->fanout;
1268 int i;
1269
1270 spin_lock(&f->lock);
1271 for (i = 0; i < f->num_members; i++) {
1272 if (f->arr[i] == sk)
1273 break;
1274 }
1275 BUG_ON(i >= f->num_members);
1276 f->arr[i] = f->arr[f->num_members - 1];
1277 f->num_members--;
1278 spin_unlock(&f->lock);
1279 }
1280
1281 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1282 {
1283 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1284 return true;
1285
1286 return false;
1287 }
1288
1289 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1290 {
1291 struct packet_sock *po = pkt_sk(sk);
1292 struct packet_fanout *f, *match;
1293 u8 type = type_flags & 0xff;
1294 u8 flags = type_flags >> 8;
1295 int err;
1296
1297 switch (type) {
1298 case PACKET_FANOUT_ROLLOVER:
1299 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1300 return -EINVAL;
1301 case PACKET_FANOUT_HASH:
1302 case PACKET_FANOUT_LB:
1303 case PACKET_FANOUT_CPU:
1304 case PACKET_FANOUT_RND:
1305 break;
1306 default:
1307 return -EINVAL;
1308 }
1309
1310 if (!po->running)
1311 return -EINVAL;
1312
1313 if (po->fanout)
1314 return -EALREADY;
1315
1316 mutex_lock(&fanout_mutex);
1317 match = NULL;
1318 list_for_each_entry(f, &fanout_list, list) {
1319 if (f->id == id &&
1320 read_pnet(&f->net) == sock_net(sk)) {
1321 match = f;
1322 break;
1323 }
1324 }
1325 err = -EINVAL;
1326 if (match && match->flags != flags)
1327 goto out;
1328 if (!match) {
1329 err = -ENOMEM;
1330 match = kzalloc(sizeof(*match), GFP_KERNEL);
1331 if (!match)
1332 goto out;
1333 write_pnet(&match->net, sock_net(sk));
1334 match->id = id;
1335 match->type = type;
1336 match->flags = flags;
1337 atomic_set(&match->rr_cur, 0);
1338 INIT_LIST_HEAD(&match->list);
1339 spin_lock_init(&match->lock);
1340 atomic_set(&match->sk_ref, 0);
1341 match->prot_hook.type = po->prot_hook.type;
1342 match->prot_hook.dev = po->prot_hook.dev;
1343 match->prot_hook.func = packet_rcv_fanout;
1344 match->prot_hook.af_packet_priv = match;
1345 match->prot_hook.id_match = match_fanout_group;
1346 dev_add_pack(&match->prot_hook);
1347 list_add(&match->list, &fanout_list);
1348 }
1349 err = -EINVAL;
1350 if (match->type == type &&
1351 match->prot_hook.type == po->prot_hook.type &&
1352 match->prot_hook.dev == po->prot_hook.dev) {
1353 err = -ENOSPC;
1354 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1355 __dev_remove_pack(&po->prot_hook);
1356 po->fanout = match;
1357 atomic_inc(&match->sk_ref);
1358 __fanout_link(sk, po);
1359 err = 0;
1360 }
1361 }
1362 out:
1363 mutex_unlock(&fanout_mutex);
1364 return err;
1365 }
1366
1367 static void fanout_release(struct sock *sk)
1368 {
1369 struct packet_sock *po = pkt_sk(sk);
1370 struct packet_fanout *f;
1371
1372 f = po->fanout;
1373 if (!f)
1374 return;
1375
1376 mutex_lock(&fanout_mutex);
1377 po->fanout = NULL;
1378
1379 if (atomic_dec_and_test(&f->sk_ref)) {
1380 list_del(&f->list);
1381 dev_remove_pack(&f->prot_hook);
1382 kfree(f);
1383 }
1384 mutex_unlock(&fanout_mutex);
1385 }
1386
1387 static const struct proto_ops packet_ops;
1388
1389 static const struct proto_ops packet_ops_spkt;
1390
1391 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1392 struct packet_type *pt, struct net_device *orig_dev)
1393 {
1394 struct sock *sk;
1395 struct sockaddr_pkt *spkt;
1396
1397 /*
1398 * When we registered the protocol we saved the socket in the data
1399 * field for just this event.
1400 */
1401
1402 sk = pt->af_packet_priv;
1403
1404 /*
1405 * Yank back the headers [hope the device set this
1406 * right or kerboom...]
1407 *
1408 * Incoming packets have ll header pulled,
1409 * push it back.
1410 *
1411 * For outgoing ones skb->data == skb_mac_header(skb)
1412 * so that this procedure is noop.
1413 */
1414
1415 if (skb->pkt_type == PACKET_LOOPBACK)
1416 goto out;
1417
1418 if (!net_eq(dev_net(dev), sock_net(sk)))
1419 goto out;
1420
1421 skb = skb_share_check(skb, GFP_ATOMIC);
1422 if (skb == NULL)
1423 goto oom;
1424
1425 /* drop any routing info */
1426 skb_dst_drop(skb);
1427
1428 /* drop conntrack reference */
1429 nf_reset(skb);
1430
1431 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1432
1433 skb_push(skb, skb->data - skb_mac_header(skb));
1434
1435 /*
1436 * The SOCK_PACKET socket receives _all_ frames.
1437 */
1438
1439 spkt->spkt_family = dev->type;
1440 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1441 spkt->spkt_protocol = skb->protocol;
1442
1443 /*
1444 * Charge the memory to the socket. This is done specifically
1445 * to prevent sockets using all the memory up.
1446 */
1447
1448 if (sock_queue_rcv_skb(sk, skb) == 0)
1449 return 0;
1450
1451 out:
1452 kfree_skb(skb);
1453 oom:
1454 return 0;
1455 }
1456
1457
1458 /*
1459 * Output a raw packet to a device layer. This bypasses all the other
1460 * protocol layers and you must therefore supply it with a complete frame
1461 */
1462
1463 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1464 struct msghdr *msg, size_t len)
1465 {
1466 struct sock *sk = sock->sk;
1467 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1468 struct sk_buff *skb = NULL;
1469 struct net_device *dev;
1470 __be16 proto = 0;
1471 int err;
1472 int extra_len = 0;
1473
1474 /*
1475 * Get and verify the address.
1476 */
1477
1478 if (saddr) {
1479 if (msg->msg_namelen < sizeof(struct sockaddr))
1480 return -EINVAL;
1481 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1482 proto = saddr->spkt_protocol;
1483 } else
1484 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1485
1486 /*
1487 * Find the device first to size check it
1488 */
1489
1490 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1491 retry:
1492 rcu_read_lock();
1493 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1494 err = -ENODEV;
1495 if (dev == NULL)
1496 goto out_unlock;
1497
1498 err = -ENETDOWN;
1499 if (!(dev->flags & IFF_UP))
1500 goto out_unlock;
1501
1502 /*
1503 * You may not queue a frame bigger than the mtu. This is the lowest level
1504 * raw protocol and you must do your own fragmentation at this level.
1505 */
1506
1507 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1508 if (!netif_supports_nofcs(dev)) {
1509 err = -EPROTONOSUPPORT;
1510 goto out_unlock;
1511 }
1512 extra_len = 4; /* We're doing our own CRC */
1513 }
1514
1515 err = -EMSGSIZE;
1516 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1517 goto out_unlock;
1518
1519 if (!skb) {
1520 size_t reserved = LL_RESERVED_SPACE(dev);
1521 int tlen = dev->needed_tailroom;
1522 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1523
1524 rcu_read_unlock();
1525 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1526 if (skb == NULL)
1527 return -ENOBUFS;
1528 /* FIXME: Save some space for broken drivers that write a hard
1529 * header at transmission time by themselves. PPP is the notable
1530 * one here. This should really be fixed at the driver level.
1531 */
1532 skb_reserve(skb, reserved);
1533 skb_reset_network_header(skb);
1534
1535 /* Try to align data part correctly */
1536 if (hhlen) {
1537 skb->data -= hhlen;
1538 skb->tail -= hhlen;
1539 if (len < hhlen)
1540 skb_reset_network_header(skb);
1541 }
1542 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1543 if (err)
1544 goto out_free;
1545 goto retry;
1546 }
1547
1548 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1549 /* Earlier code assumed this would be a VLAN pkt,
1550 * double-check this now that we have the actual
1551 * packet in hand.
1552 */
1553 struct ethhdr *ehdr;
1554 skb_reset_mac_header(skb);
1555 ehdr = eth_hdr(skb);
1556 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1557 err = -EMSGSIZE;
1558 goto out_unlock;
1559 }
1560 }
1561
1562 skb->protocol = proto;
1563 skb->dev = dev;
1564 skb->priority = sk->sk_priority;
1565 skb->mark = sk->sk_mark;
1566
1567 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1568
1569 if (unlikely(extra_len == 4))
1570 skb->no_fcs = 1;
1571
1572 skb_probe_transport_header(skb, 0);
1573
1574 dev_queue_xmit(skb);
1575 rcu_read_unlock();
1576 return len;
1577
1578 out_unlock:
1579 rcu_read_unlock();
1580 out_free:
1581 kfree_skb(skb);
1582 return err;
1583 }
1584
1585 static unsigned int run_filter(const struct sk_buff *skb,
1586 const struct sock *sk,
1587 unsigned int res)
1588 {
1589 struct sk_filter *filter;
1590
1591 rcu_read_lock();
1592 filter = rcu_dereference(sk->sk_filter);
1593 if (filter != NULL)
1594 res = SK_RUN_FILTER(filter, skb);
1595 rcu_read_unlock();
1596
1597 return res;
1598 }
1599
1600 /*
1601 * This function makes lazy skb cloning in hope that most of packets
1602 * are discarded by BPF.
1603 *
1604 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1605 * and skb->cb are mangled. It works because (and until) packets
1606 * falling here are owned by current CPU. Output packets are cloned
1607 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1608 * sequencially, so that if we return skb to original state on exit,
1609 * we will not harm anyone.
1610 */
1611
1612 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1613 struct packet_type *pt, struct net_device *orig_dev)
1614 {
1615 struct sock *sk;
1616 struct sockaddr_ll *sll;
1617 struct packet_sock *po;
1618 u8 *skb_head = skb->data;
1619 int skb_len = skb->len;
1620 unsigned int snaplen, res;
1621
1622 if (skb->pkt_type == PACKET_LOOPBACK)
1623 goto drop;
1624
1625 sk = pt->af_packet_priv;
1626 po = pkt_sk(sk);
1627
1628 if (!net_eq(dev_net(dev), sock_net(sk)))
1629 goto drop;
1630
1631 skb->dev = dev;
1632
1633 if (dev->header_ops) {
1634 /* The device has an explicit notion of ll header,
1635 * exported to higher levels.
1636 *
1637 * Otherwise, the device hides details of its frame
1638 * structure, so that corresponding packet head is
1639 * never delivered to user.
1640 */
1641 if (sk->sk_type != SOCK_DGRAM)
1642 skb_push(skb, skb->data - skb_mac_header(skb));
1643 else if (skb->pkt_type == PACKET_OUTGOING) {
1644 /* Special case: outgoing packets have ll header at head */
1645 skb_pull(skb, skb_network_offset(skb));
1646 }
1647 }
1648
1649 snaplen = skb->len;
1650
1651 res = run_filter(skb, sk, snaplen);
1652 if (!res)
1653 goto drop_n_restore;
1654 if (snaplen > res)
1655 snaplen = res;
1656
1657 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1658 goto drop_n_acct;
1659
1660 if (skb_shared(skb)) {
1661 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1662 if (nskb == NULL)
1663 goto drop_n_acct;
1664
1665 if (skb_head != skb->data) {
1666 skb->data = skb_head;
1667 skb->len = skb_len;
1668 }
1669 consume_skb(skb);
1670 skb = nskb;
1671 }
1672
1673 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1674 sizeof(skb->cb));
1675
1676 sll = &PACKET_SKB_CB(skb)->sa.ll;
1677 sll->sll_family = AF_PACKET;
1678 sll->sll_hatype = dev->type;
1679 sll->sll_protocol = skb->protocol;
1680 sll->sll_pkttype = skb->pkt_type;
1681 if (unlikely(po->origdev))
1682 sll->sll_ifindex = orig_dev->ifindex;
1683 else
1684 sll->sll_ifindex = dev->ifindex;
1685
1686 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1687
1688 PACKET_SKB_CB(skb)->origlen = skb->len;
1689
1690 if (pskb_trim(skb, snaplen))
1691 goto drop_n_acct;
1692
1693 skb_set_owner_r(skb, sk);
1694 skb->dev = NULL;
1695 skb_dst_drop(skb);
1696
1697 /* drop conntrack reference */
1698 nf_reset(skb);
1699
1700 spin_lock(&sk->sk_receive_queue.lock);
1701 po->stats.stats1.tp_packets++;
1702 skb->dropcount = atomic_read(&sk->sk_drops);
1703 __skb_queue_tail(&sk->sk_receive_queue, skb);
1704 spin_unlock(&sk->sk_receive_queue.lock);
1705 sk->sk_data_ready(sk, skb->len);
1706 return 0;
1707
1708 drop_n_acct:
1709 spin_lock(&sk->sk_receive_queue.lock);
1710 po->stats.stats1.tp_drops++;
1711 atomic_inc(&sk->sk_drops);
1712 spin_unlock(&sk->sk_receive_queue.lock);
1713
1714 drop_n_restore:
1715 if (skb_head != skb->data && skb_shared(skb)) {
1716 skb->data = skb_head;
1717 skb->len = skb_len;
1718 }
1719 drop:
1720 consume_skb(skb);
1721 return 0;
1722 }
1723
1724 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1725 struct packet_type *pt, struct net_device *orig_dev)
1726 {
1727 struct sock *sk;
1728 struct packet_sock *po;
1729 struct sockaddr_ll *sll;
1730 union tpacket_uhdr h;
1731 u8 *skb_head = skb->data;
1732 int skb_len = skb->len;
1733 unsigned int snaplen, res;
1734 unsigned long status = TP_STATUS_USER;
1735 unsigned short macoff, netoff, hdrlen;
1736 struct sk_buff *copy_skb = NULL;
1737 struct timespec ts;
1738 __u32 ts_status;
1739
1740 if (skb->pkt_type == PACKET_LOOPBACK)
1741 goto drop;
1742
1743 sk = pt->af_packet_priv;
1744 po = pkt_sk(sk);
1745
1746 if (!net_eq(dev_net(dev), sock_net(sk)))
1747 goto drop;
1748
1749 if (dev->header_ops) {
1750 if (sk->sk_type != SOCK_DGRAM)
1751 skb_push(skb, skb->data - skb_mac_header(skb));
1752 else if (skb->pkt_type == PACKET_OUTGOING) {
1753 /* Special case: outgoing packets have ll header at head */
1754 skb_pull(skb, skb_network_offset(skb));
1755 }
1756 }
1757
1758 if (skb->ip_summed == CHECKSUM_PARTIAL)
1759 status |= TP_STATUS_CSUMNOTREADY;
1760
1761 snaplen = skb->len;
1762
1763 res = run_filter(skb, sk, snaplen);
1764 if (!res)
1765 goto drop_n_restore;
1766 if (snaplen > res)
1767 snaplen = res;
1768
1769 if (sk->sk_type == SOCK_DGRAM) {
1770 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1771 po->tp_reserve;
1772 } else {
1773 unsigned int maclen = skb_network_offset(skb);
1774 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1775 (maclen < 16 ? 16 : maclen)) +
1776 po->tp_reserve;
1777 macoff = netoff - maclen;
1778 }
1779 if (po->tp_version <= TPACKET_V2) {
1780 if (macoff + snaplen > po->rx_ring.frame_size) {
1781 if (po->copy_thresh &&
1782 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1783 if (skb_shared(skb)) {
1784 copy_skb = skb_clone(skb, GFP_ATOMIC);
1785 } else {
1786 copy_skb = skb_get(skb);
1787 skb_head = skb->data;
1788 }
1789 if (copy_skb)
1790 skb_set_owner_r(copy_skb, sk);
1791 }
1792 snaplen = po->rx_ring.frame_size - macoff;
1793 if ((int)snaplen < 0)
1794 snaplen = 0;
1795 }
1796 }
1797 spin_lock(&sk->sk_receive_queue.lock);
1798 h.raw = packet_current_rx_frame(po, skb,
1799 TP_STATUS_KERNEL, (macoff+snaplen));
1800 if (!h.raw)
1801 goto ring_is_full;
1802 if (po->tp_version <= TPACKET_V2) {
1803 packet_increment_rx_head(po, &po->rx_ring);
1804 /*
1805 * LOSING will be reported till you read the stats,
1806 * because it's COR - Clear On Read.
1807 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1808 * at packet level.
1809 */
1810 if (po->stats.stats1.tp_drops)
1811 status |= TP_STATUS_LOSING;
1812 }
1813 po->stats.stats1.tp_packets++;
1814 if (copy_skb) {
1815 status |= TP_STATUS_COPY;
1816 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1817 }
1818 spin_unlock(&sk->sk_receive_queue.lock);
1819
1820 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1821
1822 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1823 getnstimeofday(&ts);
1824
1825 status |= ts_status;
1826
1827 switch (po->tp_version) {
1828 case TPACKET_V1:
1829 h.h1->tp_len = skb->len;
1830 h.h1->tp_snaplen = snaplen;
1831 h.h1->tp_mac = macoff;
1832 h.h1->tp_net = netoff;
1833 h.h1->tp_sec = ts.tv_sec;
1834 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1835 hdrlen = sizeof(*h.h1);
1836 break;
1837 case TPACKET_V2:
1838 h.h2->tp_len = skb->len;
1839 h.h2->tp_snaplen = snaplen;
1840 h.h2->tp_mac = macoff;
1841 h.h2->tp_net = netoff;
1842 h.h2->tp_sec = ts.tv_sec;
1843 h.h2->tp_nsec = ts.tv_nsec;
1844 if (vlan_tx_tag_present(skb)) {
1845 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1846 status |= TP_STATUS_VLAN_VALID;
1847 } else {
1848 h.h2->tp_vlan_tci = 0;
1849 }
1850 h.h2->tp_padding = 0;
1851 hdrlen = sizeof(*h.h2);
1852 break;
1853 case TPACKET_V3:
1854 /* tp_nxt_offset,vlan are already populated above.
1855 * So DONT clear those fields here
1856 */
1857 h.h3->tp_status |= status;
1858 h.h3->tp_len = skb->len;
1859 h.h3->tp_snaplen = snaplen;
1860 h.h3->tp_mac = macoff;
1861 h.h3->tp_net = netoff;
1862 h.h3->tp_sec = ts.tv_sec;
1863 h.h3->tp_nsec = ts.tv_nsec;
1864 hdrlen = sizeof(*h.h3);
1865 break;
1866 default:
1867 BUG();
1868 }
1869
1870 sll = h.raw + TPACKET_ALIGN(hdrlen);
1871 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1872 sll->sll_family = AF_PACKET;
1873 sll->sll_hatype = dev->type;
1874 sll->sll_protocol = skb->protocol;
1875 sll->sll_pkttype = skb->pkt_type;
1876 if (unlikely(po->origdev))
1877 sll->sll_ifindex = orig_dev->ifindex;
1878 else
1879 sll->sll_ifindex = dev->ifindex;
1880
1881 smp_mb();
1882 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1883 {
1884 u8 *start, *end;
1885
1886 if (po->tp_version <= TPACKET_V2) {
1887 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1888 + macoff + snaplen);
1889 for (start = h.raw; start < end; start += PAGE_SIZE)
1890 flush_dcache_page(pgv_to_page(start));
1891 }
1892 smp_wmb();
1893 }
1894 #endif
1895 if (po->tp_version <= TPACKET_V2)
1896 __packet_set_status(po, h.raw, status);
1897 else
1898 prb_clear_blk_fill_status(&po->rx_ring);
1899
1900 sk->sk_data_ready(sk, 0);
1901
1902 drop_n_restore:
1903 if (skb_head != skb->data && skb_shared(skb)) {
1904 skb->data = skb_head;
1905 skb->len = skb_len;
1906 }
1907 drop:
1908 kfree_skb(skb);
1909 return 0;
1910
1911 ring_is_full:
1912 po->stats.stats1.tp_drops++;
1913 spin_unlock(&sk->sk_receive_queue.lock);
1914
1915 sk->sk_data_ready(sk, 0);
1916 kfree_skb(copy_skb);
1917 goto drop_n_restore;
1918 }
1919
1920 static void tpacket_destruct_skb(struct sk_buff *skb)
1921 {
1922 struct packet_sock *po = pkt_sk(skb->sk);
1923 void *ph;
1924
1925 if (likely(po->tx_ring.pg_vec)) {
1926 __u32 ts;
1927
1928 ph = skb_shinfo(skb)->destructor_arg;
1929 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1930 atomic_dec(&po->tx_ring.pending);
1931
1932 ts = __packet_set_timestamp(po, ph, skb);
1933 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
1934 }
1935
1936 sock_wfree(skb);
1937 }
1938
1939 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1940 void *frame, struct net_device *dev, int size_max,
1941 __be16 proto, unsigned char *addr, int hlen)
1942 {
1943 union tpacket_uhdr ph;
1944 int to_write, offset, len, tp_len, nr_frags, len_max;
1945 struct socket *sock = po->sk.sk_socket;
1946 struct page *page;
1947 void *data;
1948 int err;
1949
1950 ph.raw = frame;
1951
1952 skb->protocol = proto;
1953 skb->dev = dev;
1954 skb->priority = po->sk.sk_priority;
1955 skb->mark = po->sk.sk_mark;
1956 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
1957 skb_shinfo(skb)->destructor_arg = ph.raw;
1958
1959 switch (po->tp_version) {
1960 case TPACKET_V2:
1961 tp_len = ph.h2->tp_len;
1962 break;
1963 default:
1964 tp_len = ph.h1->tp_len;
1965 break;
1966 }
1967 if (unlikely(tp_len > size_max)) {
1968 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1969 return -EMSGSIZE;
1970 }
1971
1972 skb_reserve(skb, hlen);
1973 skb_reset_network_header(skb);
1974 skb_probe_transport_header(skb, 0);
1975
1976 if (po->tp_tx_has_off) {
1977 int off_min, off_max, off;
1978 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
1979 off_max = po->tx_ring.frame_size - tp_len;
1980 if (sock->type == SOCK_DGRAM) {
1981 switch (po->tp_version) {
1982 case TPACKET_V2:
1983 off = ph.h2->tp_net;
1984 break;
1985 default:
1986 off = ph.h1->tp_net;
1987 break;
1988 }
1989 } else {
1990 switch (po->tp_version) {
1991 case TPACKET_V2:
1992 off = ph.h2->tp_mac;
1993 break;
1994 default:
1995 off = ph.h1->tp_mac;
1996 break;
1997 }
1998 }
1999 if (unlikely((off < off_min) || (off_max < off)))
2000 return -EINVAL;
2001 data = ph.raw + off;
2002 } else {
2003 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2004 }
2005 to_write = tp_len;
2006
2007 if (sock->type == SOCK_DGRAM) {
2008 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2009 NULL, tp_len);
2010 if (unlikely(err < 0))
2011 return -EINVAL;
2012 } else if (dev->hard_header_len) {
2013 /* net device doesn't like empty head */
2014 if (unlikely(tp_len <= dev->hard_header_len)) {
2015 pr_err("packet size is too short (%d < %d)\n",
2016 tp_len, dev->hard_header_len);
2017 return -EINVAL;
2018 }
2019
2020 skb_push(skb, dev->hard_header_len);
2021 err = skb_store_bits(skb, 0, data,
2022 dev->hard_header_len);
2023 if (unlikely(err))
2024 return err;
2025
2026 data += dev->hard_header_len;
2027 to_write -= dev->hard_header_len;
2028 }
2029
2030 offset = offset_in_page(data);
2031 len_max = PAGE_SIZE - offset;
2032 len = ((to_write > len_max) ? len_max : to_write);
2033
2034 skb->data_len = to_write;
2035 skb->len += to_write;
2036 skb->truesize += to_write;
2037 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2038
2039 while (likely(to_write)) {
2040 nr_frags = skb_shinfo(skb)->nr_frags;
2041
2042 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2043 pr_err("Packet exceed the number of skb frags(%lu)\n",
2044 MAX_SKB_FRAGS);
2045 return -EFAULT;
2046 }
2047
2048 page = pgv_to_page(data);
2049 data += len;
2050 flush_dcache_page(page);
2051 get_page(page);
2052 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2053 to_write -= len;
2054 offset = 0;
2055 len_max = PAGE_SIZE;
2056 len = ((to_write > len_max) ? len_max : to_write);
2057 }
2058
2059 return tp_len;
2060 }
2061
2062 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
2063 {
2064 struct net_device *dev;
2065
2066 rcu_read_lock();
2067 dev = rcu_dereference(po->cached_dev);
2068 if (dev)
2069 dev_hold(dev);
2070 rcu_read_unlock();
2071
2072 return dev;
2073 }
2074
2075 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2076 {
2077 struct sk_buff *skb;
2078 struct net_device *dev;
2079 __be16 proto;
2080 int err, reserve = 0;
2081 void *ph;
2082 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2083 int tp_len, size_max;
2084 unsigned char *addr;
2085 int len_sum = 0;
2086 int status = TP_STATUS_AVAILABLE;
2087 int hlen, tlen;
2088
2089 mutex_lock(&po->pg_vec_lock);
2090
2091 if (saddr == NULL) {
2092 dev = packet_cached_dev_get(po);
2093 proto = po->num;
2094 addr = NULL;
2095 } else {
2096 err = -EINVAL;
2097 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2098 goto out;
2099 if (msg->msg_namelen < (saddr->sll_halen
2100 + offsetof(struct sockaddr_ll,
2101 sll_addr)))
2102 goto out;
2103 proto = saddr->sll_protocol;
2104 addr = saddr->sll_addr;
2105 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2106 }
2107
2108 err = -ENXIO;
2109 if (unlikely(dev == NULL))
2110 goto out;
2111 err = -ENETDOWN;
2112 if (unlikely(!(dev->flags & IFF_UP)))
2113 goto out_put;
2114
2115 reserve = dev->hard_header_len;
2116
2117 size_max = po->tx_ring.frame_size
2118 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2119
2120 if (size_max > dev->mtu + reserve)
2121 size_max = dev->mtu + reserve;
2122
2123 do {
2124 ph = packet_current_frame(po, &po->tx_ring,
2125 TP_STATUS_SEND_REQUEST);
2126
2127 if (unlikely(ph == NULL)) {
2128 schedule();
2129 continue;
2130 }
2131
2132 status = TP_STATUS_SEND_REQUEST;
2133 hlen = LL_RESERVED_SPACE(dev);
2134 tlen = dev->needed_tailroom;
2135 skb = sock_alloc_send_skb(&po->sk,
2136 hlen + tlen + sizeof(struct sockaddr_ll),
2137 0, &err);
2138
2139 if (unlikely(skb == NULL))
2140 goto out_status;
2141
2142 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2143 addr, hlen);
2144
2145 if (unlikely(tp_len < 0)) {
2146 if (po->tp_loss) {
2147 __packet_set_status(po, ph,
2148 TP_STATUS_AVAILABLE);
2149 packet_increment_head(&po->tx_ring);
2150 kfree_skb(skb);
2151 continue;
2152 } else {
2153 status = TP_STATUS_WRONG_FORMAT;
2154 err = tp_len;
2155 goto out_status;
2156 }
2157 }
2158
2159 skb->destructor = tpacket_destruct_skb;
2160 __packet_set_status(po, ph, TP_STATUS_SENDING);
2161 atomic_inc(&po->tx_ring.pending);
2162
2163 status = TP_STATUS_SEND_REQUEST;
2164 err = dev_queue_xmit(skb);
2165 if (unlikely(err > 0)) {
2166 err = net_xmit_errno(err);
2167 if (err && __packet_get_status(po, ph) ==
2168 TP_STATUS_AVAILABLE) {
2169 /* skb was destructed already */
2170 skb = NULL;
2171 goto out_status;
2172 }
2173 /*
2174 * skb was dropped but not destructed yet;
2175 * let's treat it like congestion or err < 0
2176 */
2177 err = 0;
2178 }
2179 packet_increment_head(&po->tx_ring);
2180 len_sum += tp_len;
2181 } while (likely((ph != NULL) ||
2182 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2183 (atomic_read(&po->tx_ring.pending))))
2184 );
2185
2186 err = len_sum;
2187 goto out_put;
2188
2189 out_status:
2190 __packet_set_status(po, ph, status);
2191 kfree_skb(skb);
2192 out_put:
2193 dev_put(dev);
2194 out:
2195 mutex_unlock(&po->pg_vec_lock);
2196 return err;
2197 }
2198
2199 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2200 size_t reserve, size_t len,
2201 size_t linear, int noblock,
2202 int *err)
2203 {
2204 struct sk_buff *skb;
2205
2206 /* Under a page? Don't bother with paged skb. */
2207 if (prepad + len < PAGE_SIZE || !linear)
2208 linear = len;
2209
2210 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2211 err, 0);
2212 if (!skb)
2213 return NULL;
2214
2215 skb_reserve(skb, reserve);
2216 skb_put(skb, linear);
2217 skb->data_len = len - linear;
2218 skb->len += len - linear;
2219
2220 return skb;
2221 }
2222
2223 static int packet_snd(struct socket *sock,
2224 struct msghdr *msg, size_t len)
2225 {
2226 struct sock *sk = sock->sk;
2227 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2228 struct sk_buff *skb;
2229 struct net_device *dev;
2230 __be16 proto;
2231 unsigned char *addr;
2232 int err, reserve = 0;
2233 struct virtio_net_hdr vnet_hdr = { 0 };
2234 int offset = 0;
2235 int vnet_hdr_len;
2236 struct packet_sock *po = pkt_sk(sk);
2237 unsigned short gso_type = 0;
2238 int hlen, tlen;
2239 int extra_len = 0;
2240
2241 /*
2242 * Get and verify the address.
2243 */
2244
2245 if (saddr == NULL) {
2246 dev = packet_cached_dev_get(po);
2247 proto = po->num;
2248 addr = NULL;
2249 } else {
2250 err = -EINVAL;
2251 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2252 goto out;
2253 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2254 goto out;
2255 proto = saddr->sll_protocol;
2256 addr = saddr->sll_addr;
2257 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2258 }
2259
2260 err = -ENXIO;
2261 if (unlikely(dev == NULL))
2262 goto out_unlock;
2263 err = -ENETDOWN;
2264 if (unlikely(!(dev->flags & IFF_UP)))
2265 goto out_unlock;
2266
2267 if (sock->type == SOCK_RAW)
2268 reserve = dev->hard_header_len;
2269 if (po->has_vnet_hdr) {
2270 vnet_hdr_len = sizeof(vnet_hdr);
2271
2272 err = -EINVAL;
2273 if (len < vnet_hdr_len)
2274 goto out_unlock;
2275
2276 len -= vnet_hdr_len;
2277
2278 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2279 vnet_hdr_len);
2280 if (err < 0)
2281 goto out_unlock;
2282
2283 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2284 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2285 vnet_hdr.hdr_len))
2286 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2287 vnet_hdr.csum_offset + 2;
2288
2289 err = -EINVAL;
2290 if (vnet_hdr.hdr_len > len)
2291 goto out_unlock;
2292
2293 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2294 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2295 case VIRTIO_NET_HDR_GSO_TCPV4:
2296 gso_type = SKB_GSO_TCPV4;
2297 break;
2298 case VIRTIO_NET_HDR_GSO_TCPV6:
2299 gso_type = SKB_GSO_TCPV6;
2300 break;
2301 case VIRTIO_NET_HDR_GSO_UDP:
2302 gso_type = SKB_GSO_UDP;
2303 break;
2304 default:
2305 goto out_unlock;
2306 }
2307
2308 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2309 gso_type |= SKB_GSO_TCP_ECN;
2310
2311 if (vnet_hdr.gso_size == 0)
2312 goto out_unlock;
2313
2314 }
2315 }
2316
2317 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2318 if (!netif_supports_nofcs(dev)) {
2319 err = -EPROTONOSUPPORT;
2320 goto out_unlock;
2321 }
2322 extra_len = 4; /* We're doing our own CRC */
2323 }
2324
2325 err = -EMSGSIZE;
2326 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2327 goto out_unlock;
2328
2329 err = -ENOBUFS;
2330 hlen = LL_RESERVED_SPACE(dev);
2331 tlen = dev->needed_tailroom;
2332 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2333 msg->msg_flags & MSG_DONTWAIT, &err);
2334 if (skb == NULL)
2335 goto out_unlock;
2336
2337 skb_set_network_header(skb, reserve);
2338
2339 err = -EINVAL;
2340 if (sock->type == SOCK_DGRAM &&
2341 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2342 goto out_free;
2343
2344 /* Returns -EFAULT on error */
2345 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2346 if (err)
2347 goto out_free;
2348
2349 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2350
2351 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2352 /* Earlier code assumed this would be a VLAN pkt,
2353 * double-check this now that we have the actual
2354 * packet in hand.
2355 */
2356 struct ethhdr *ehdr;
2357 skb_reset_mac_header(skb);
2358 ehdr = eth_hdr(skb);
2359 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2360 err = -EMSGSIZE;
2361 goto out_free;
2362 }
2363 }
2364
2365 skb->protocol = proto;
2366 skb->dev = dev;
2367 skb->priority = sk->sk_priority;
2368 skb->mark = sk->sk_mark;
2369
2370 if (po->has_vnet_hdr) {
2371 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2372 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2373 vnet_hdr.csum_offset)) {
2374 err = -EINVAL;
2375 goto out_free;
2376 }
2377 }
2378
2379 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2380 skb_shinfo(skb)->gso_type = gso_type;
2381
2382 /* Header must be checked, and gso_segs computed. */
2383 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2384 skb_shinfo(skb)->gso_segs = 0;
2385
2386 len += vnet_hdr_len;
2387 }
2388
2389 skb_probe_transport_header(skb, reserve);
2390
2391 if (unlikely(extra_len == 4))
2392 skb->no_fcs = 1;
2393
2394 /*
2395 * Now send it
2396 */
2397
2398 err = dev_queue_xmit(skb);
2399 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2400 goto out_unlock;
2401
2402 dev_put(dev);
2403
2404 return len;
2405
2406 out_free:
2407 kfree_skb(skb);
2408 out_unlock:
2409 if (dev)
2410 dev_put(dev);
2411 out:
2412 return err;
2413 }
2414
2415 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2416 struct msghdr *msg, size_t len)
2417 {
2418 struct sock *sk = sock->sk;
2419 struct packet_sock *po = pkt_sk(sk);
2420 if (po->tx_ring.pg_vec)
2421 return tpacket_snd(po, msg);
2422 else
2423 return packet_snd(sock, msg, len);
2424 }
2425
2426 /*
2427 * Close a PACKET socket. This is fairly simple. We immediately go
2428 * to 'closed' state and remove our protocol entry in the device list.
2429 */
2430
2431 static int packet_release(struct socket *sock)
2432 {
2433 struct sock *sk = sock->sk;
2434 struct packet_sock *po;
2435 struct net *net;
2436 union tpacket_req_u req_u;
2437
2438 if (!sk)
2439 return 0;
2440
2441 net = sock_net(sk);
2442 po = pkt_sk(sk);
2443
2444 mutex_lock(&net->packet.sklist_lock);
2445 sk_del_node_init_rcu(sk);
2446 mutex_unlock(&net->packet.sklist_lock);
2447
2448 preempt_disable();
2449 sock_prot_inuse_add(net, sk->sk_prot, -1);
2450 preempt_enable();
2451
2452 spin_lock(&po->bind_lock);
2453 unregister_prot_hook(sk, false);
2454 if (po->prot_hook.dev) {
2455 dev_put(po->prot_hook.dev);
2456 po->prot_hook.dev = NULL;
2457 }
2458 spin_unlock(&po->bind_lock);
2459
2460 packet_flush_mclist(sk);
2461
2462 if (po->rx_ring.pg_vec) {
2463 memset(&req_u, 0, sizeof(req_u));
2464 packet_set_ring(sk, &req_u, 1, 0);
2465 }
2466
2467 if (po->tx_ring.pg_vec) {
2468 memset(&req_u, 0, sizeof(req_u));
2469 packet_set_ring(sk, &req_u, 1, 1);
2470 }
2471
2472 fanout_release(sk);
2473
2474 synchronize_net();
2475 /*
2476 * Now the socket is dead. No more input will appear.
2477 */
2478 sock_orphan(sk);
2479 sock->sk = NULL;
2480
2481 /* Purge queues */
2482
2483 skb_queue_purge(&sk->sk_receive_queue);
2484 sk_refcnt_debug_release(sk);
2485
2486 sock_put(sk);
2487 return 0;
2488 }
2489
2490 /*
2491 * Attach a packet hook.
2492 */
2493
2494 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2495 {
2496 struct packet_sock *po = pkt_sk(sk);
2497
2498 if (po->fanout) {
2499 if (dev)
2500 dev_put(dev);
2501
2502 return -EINVAL;
2503 }
2504
2505 lock_sock(sk);
2506
2507 spin_lock(&po->bind_lock);
2508 unregister_prot_hook(sk, true);
2509 po->num = protocol;
2510 po->prot_hook.type = protocol;
2511 if (po->prot_hook.dev)
2512 dev_put(po->prot_hook.dev);
2513 po->prot_hook.dev = dev;
2514
2515 po->ifindex = dev ? dev->ifindex : 0;
2516
2517 if (protocol == 0)
2518 goto out_unlock;
2519
2520 if (!dev || (dev->flags & IFF_UP)) {
2521 register_prot_hook(sk);
2522 } else {
2523 sk->sk_err = ENETDOWN;
2524 if (!sock_flag(sk, SOCK_DEAD))
2525 sk->sk_error_report(sk);
2526 }
2527
2528 out_unlock:
2529 spin_unlock(&po->bind_lock);
2530 release_sock(sk);
2531 return 0;
2532 }
2533
2534 /*
2535 * Bind a packet socket to a device
2536 */
2537
2538 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2539 int addr_len)
2540 {
2541 struct sock *sk = sock->sk;
2542 char name[15];
2543 struct net_device *dev;
2544 int err = -ENODEV;
2545
2546 /*
2547 * Check legality
2548 */
2549
2550 if (addr_len != sizeof(struct sockaddr))
2551 return -EINVAL;
2552 strlcpy(name, uaddr->sa_data, sizeof(name));
2553
2554 dev = dev_get_by_name(sock_net(sk), name);
2555 if (dev)
2556 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2557 return err;
2558 }
2559
2560 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2561 {
2562 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2563 struct sock *sk = sock->sk;
2564 struct net_device *dev = NULL;
2565 int err;
2566
2567
2568 /*
2569 * Check legality
2570 */
2571
2572 if (addr_len < sizeof(struct sockaddr_ll))
2573 return -EINVAL;
2574 if (sll->sll_family != AF_PACKET)
2575 return -EINVAL;
2576
2577 if (sll->sll_ifindex) {
2578 err = -ENODEV;
2579 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2580 if (dev == NULL)
2581 goto out;
2582 }
2583 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2584
2585 out:
2586 return err;
2587 }
2588
2589 static struct proto packet_proto = {
2590 .name = "PACKET",
2591 .owner = THIS_MODULE,
2592 .obj_size = sizeof(struct packet_sock),
2593 };
2594
2595 /*
2596 * Create a packet of type SOCK_PACKET.
2597 */
2598
2599 static int packet_create(struct net *net, struct socket *sock, int protocol,
2600 int kern)
2601 {
2602 struct sock *sk;
2603 struct packet_sock *po;
2604 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2605 int err;
2606
2607 if (!ns_capable(net->user_ns, CAP_NET_RAW))
2608 return -EPERM;
2609 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2610 sock->type != SOCK_PACKET)
2611 return -ESOCKTNOSUPPORT;
2612
2613 sock->state = SS_UNCONNECTED;
2614
2615 err = -ENOBUFS;
2616 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2617 if (sk == NULL)
2618 goto out;
2619
2620 sock->ops = &packet_ops;
2621 if (sock->type == SOCK_PACKET)
2622 sock->ops = &packet_ops_spkt;
2623
2624 sock_init_data(sock, sk);
2625
2626 po = pkt_sk(sk);
2627 sk->sk_family = PF_PACKET;
2628 po->num = proto;
2629 RCU_INIT_POINTER(po->cached_dev, NULL);
2630
2631 sk->sk_destruct = packet_sock_destruct;
2632 sk_refcnt_debug_inc(sk);
2633
2634 /*
2635 * Attach a protocol block
2636 */
2637
2638 spin_lock_init(&po->bind_lock);
2639 mutex_init(&po->pg_vec_lock);
2640 po->prot_hook.func = packet_rcv;
2641
2642 if (sock->type == SOCK_PACKET)
2643 po->prot_hook.func = packet_rcv_spkt;
2644
2645 po->prot_hook.af_packet_priv = sk;
2646
2647 if (proto) {
2648 po->prot_hook.type = proto;
2649 register_prot_hook(sk);
2650 }
2651
2652 mutex_lock(&net->packet.sklist_lock);
2653 sk_add_node_rcu(sk, &net->packet.sklist);
2654 mutex_unlock(&net->packet.sklist_lock);
2655
2656 preempt_disable();
2657 sock_prot_inuse_add(net, &packet_proto, 1);
2658 preempt_enable();
2659
2660 return 0;
2661 out:
2662 return err;
2663 }
2664
2665 /*
2666 * Pull a packet from our receive queue and hand it to the user.
2667 * If necessary we block.
2668 */
2669
2670 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2671 struct msghdr *msg, size_t len, int flags)
2672 {
2673 struct sock *sk = sock->sk;
2674 struct sk_buff *skb;
2675 int copied, err;
2676 int vnet_hdr_len = 0;
2677
2678 err = -EINVAL;
2679 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2680 goto out;
2681
2682 #if 0
2683 /* What error should we return now? EUNATTACH? */
2684 if (pkt_sk(sk)->ifindex < 0)
2685 return -ENODEV;
2686 #endif
2687
2688 if (flags & MSG_ERRQUEUE) {
2689 err = sock_recv_errqueue(sk, msg, len,
2690 SOL_PACKET, PACKET_TX_TIMESTAMP);
2691 goto out;
2692 }
2693
2694 /*
2695 * Call the generic datagram receiver. This handles all sorts
2696 * of horrible races and re-entrancy so we can forget about it
2697 * in the protocol layers.
2698 *
2699 * Now it will return ENETDOWN, if device have just gone down,
2700 * but then it will block.
2701 */
2702
2703 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2704
2705 /*
2706 * An error occurred so return it. Because skb_recv_datagram()
2707 * handles the blocking we don't see and worry about blocking
2708 * retries.
2709 */
2710
2711 if (skb == NULL)
2712 goto out;
2713
2714 if (pkt_sk(sk)->has_vnet_hdr) {
2715 struct virtio_net_hdr vnet_hdr = { 0 };
2716
2717 err = -EINVAL;
2718 vnet_hdr_len = sizeof(vnet_hdr);
2719 if (len < vnet_hdr_len)
2720 goto out_free;
2721
2722 len -= vnet_hdr_len;
2723
2724 if (skb_is_gso(skb)) {
2725 struct skb_shared_info *sinfo = skb_shinfo(skb);
2726
2727 /* This is a hint as to how much should be linear. */
2728 vnet_hdr.hdr_len = skb_headlen(skb);
2729 vnet_hdr.gso_size = sinfo->gso_size;
2730 if (sinfo->gso_type & SKB_GSO_TCPV4)
2731 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2732 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2733 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2734 else if (sinfo->gso_type & SKB_GSO_UDP)
2735 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2736 else if (sinfo->gso_type & SKB_GSO_FCOE)
2737 goto out_free;
2738 else
2739 BUG();
2740 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2741 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2742 } else
2743 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2744
2745 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2746 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2747 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2748 vnet_hdr.csum_offset = skb->csum_offset;
2749 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2750 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2751 } /* else everything is zero */
2752
2753 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2754 vnet_hdr_len);
2755 if (err < 0)
2756 goto out_free;
2757 }
2758
2759 /* You lose any data beyond the buffer you gave. If it worries
2760 * a user program they can ask the device for its MTU
2761 * anyway.
2762 */
2763 copied = skb->len;
2764 if (copied > len) {
2765 copied = len;
2766 msg->msg_flags |= MSG_TRUNC;
2767 }
2768
2769 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2770 if (err)
2771 goto out_free;
2772
2773 sock_recv_ts_and_drops(msg, sk, skb);
2774
2775 if (msg->msg_name) {
2776 /* If the address length field is there to be filled
2777 * in, we fill it in now.
2778 */
2779 if (sock->type == SOCK_PACKET) {
2780 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2781 } else {
2782 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
2783 msg->msg_namelen = sll->sll_halen +
2784 offsetof(struct sockaddr_ll, sll_addr);
2785 }
2786 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2787 msg->msg_namelen);
2788 }
2789
2790 if (pkt_sk(sk)->auxdata) {
2791 struct tpacket_auxdata aux;
2792
2793 aux.tp_status = TP_STATUS_USER;
2794 if (skb->ip_summed == CHECKSUM_PARTIAL)
2795 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2796 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2797 aux.tp_snaplen = skb->len;
2798 aux.tp_mac = 0;
2799 aux.tp_net = skb_network_offset(skb);
2800 if (vlan_tx_tag_present(skb)) {
2801 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2802 aux.tp_status |= TP_STATUS_VLAN_VALID;
2803 } else {
2804 aux.tp_vlan_tci = 0;
2805 }
2806 aux.tp_padding = 0;
2807 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2808 }
2809
2810 /*
2811 * Free or return the buffer as appropriate. Again this
2812 * hides all the races and re-entrancy issues from us.
2813 */
2814 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2815
2816 out_free:
2817 skb_free_datagram(sk, skb);
2818 out:
2819 return err;
2820 }
2821
2822 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2823 int *uaddr_len, int peer)
2824 {
2825 struct net_device *dev;
2826 struct sock *sk = sock->sk;
2827
2828 if (peer)
2829 return -EOPNOTSUPP;
2830
2831 uaddr->sa_family = AF_PACKET;
2832 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
2833 rcu_read_lock();
2834 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2835 if (dev)
2836 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
2837 rcu_read_unlock();
2838 *uaddr_len = sizeof(*uaddr);
2839
2840 return 0;
2841 }
2842
2843 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2844 int *uaddr_len, int peer)
2845 {
2846 struct net_device *dev;
2847 struct sock *sk = sock->sk;
2848 struct packet_sock *po = pkt_sk(sk);
2849 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2850
2851 if (peer)
2852 return -EOPNOTSUPP;
2853
2854 sll->sll_family = AF_PACKET;
2855 sll->sll_ifindex = po->ifindex;
2856 sll->sll_protocol = po->num;
2857 sll->sll_pkttype = 0;
2858 rcu_read_lock();
2859 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2860 if (dev) {
2861 sll->sll_hatype = dev->type;
2862 sll->sll_halen = dev->addr_len;
2863 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2864 } else {
2865 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2866 sll->sll_halen = 0;
2867 }
2868 rcu_read_unlock();
2869 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2870
2871 return 0;
2872 }
2873
2874 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2875 int what)
2876 {
2877 switch (i->type) {
2878 case PACKET_MR_MULTICAST:
2879 if (i->alen != dev->addr_len)
2880 return -EINVAL;
2881 if (what > 0)
2882 return dev_mc_add(dev, i->addr);
2883 else
2884 return dev_mc_del(dev, i->addr);
2885 break;
2886 case PACKET_MR_PROMISC:
2887 return dev_set_promiscuity(dev, what);
2888 break;
2889 case PACKET_MR_ALLMULTI:
2890 return dev_set_allmulti(dev, what);
2891 break;
2892 case PACKET_MR_UNICAST:
2893 if (i->alen != dev->addr_len)
2894 return -EINVAL;
2895 if (what > 0)
2896 return dev_uc_add(dev, i->addr);
2897 else
2898 return dev_uc_del(dev, i->addr);
2899 break;
2900 default:
2901 break;
2902 }
2903 return 0;
2904 }
2905
2906 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2907 {
2908 for ( ; i; i = i->next) {
2909 if (i->ifindex == dev->ifindex)
2910 packet_dev_mc(dev, i, what);
2911 }
2912 }
2913
2914 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2915 {
2916 struct packet_sock *po = pkt_sk(sk);
2917 struct packet_mclist *ml, *i;
2918 struct net_device *dev;
2919 int err;
2920
2921 rtnl_lock();
2922
2923 err = -ENODEV;
2924 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2925 if (!dev)
2926 goto done;
2927
2928 err = -EINVAL;
2929 if (mreq->mr_alen > dev->addr_len)
2930 goto done;
2931
2932 err = -ENOBUFS;
2933 i = kmalloc(sizeof(*i), GFP_KERNEL);
2934 if (i == NULL)
2935 goto done;
2936
2937 err = 0;
2938 for (ml = po->mclist; ml; ml = ml->next) {
2939 if (ml->ifindex == mreq->mr_ifindex &&
2940 ml->type == mreq->mr_type &&
2941 ml->alen == mreq->mr_alen &&
2942 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2943 ml->count++;
2944 /* Free the new element ... */
2945 kfree(i);
2946 goto done;
2947 }
2948 }
2949
2950 i->type = mreq->mr_type;
2951 i->ifindex = mreq->mr_ifindex;
2952 i->alen = mreq->mr_alen;
2953 memcpy(i->addr, mreq->mr_address, i->alen);
2954 i->count = 1;
2955 i->next = po->mclist;
2956 po->mclist = i;
2957 err = packet_dev_mc(dev, i, 1);
2958 if (err) {
2959 po->mclist = i->next;
2960 kfree(i);
2961 }
2962
2963 done:
2964 rtnl_unlock();
2965 return err;
2966 }
2967
2968 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2969 {
2970 struct packet_mclist *ml, **mlp;
2971
2972 rtnl_lock();
2973
2974 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2975 if (ml->ifindex == mreq->mr_ifindex &&
2976 ml->type == mreq->mr_type &&
2977 ml->alen == mreq->mr_alen &&
2978 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2979 if (--ml->count == 0) {
2980 struct net_device *dev;
2981 *mlp = ml->next;
2982 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2983 if (dev)
2984 packet_dev_mc(dev, ml, -1);
2985 kfree(ml);
2986 }
2987 rtnl_unlock();
2988 return 0;
2989 }
2990 }
2991 rtnl_unlock();
2992 return -EADDRNOTAVAIL;
2993 }
2994
2995 static void packet_flush_mclist(struct sock *sk)
2996 {
2997 struct packet_sock *po = pkt_sk(sk);
2998 struct packet_mclist *ml;
2999
3000 if (!po->mclist)
3001 return;
3002
3003 rtnl_lock();
3004 while ((ml = po->mclist) != NULL) {
3005 struct net_device *dev;
3006
3007 po->mclist = ml->next;
3008 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3009 if (dev != NULL)
3010 packet_dev_mc(dev, ml, -1);
3011 kfree(ml);
3012 }
3013 rtnl_unlock();
3014 }
3015
3016 static int
3017 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3018 {
3019 struct sock *sk = sock->sk;
3020 struct packet_sock *po = pkt_sk(sk);
3021 int ret;
3022
3023 if (level != SOL_PACKET)
3024 return -ENOPROTOOPT;
3025
3026 switch (optname) {
3027 case PACKET_ADD_MEMBERSHIP:
3028 case PACKET_DROP_MEMBERSHIP:
3029 {
3030 struct packet_mreq_max mreq;
3031 int len = optlen;
3032 memset(&mreq, 0, sizeof(mreq));
3033 if (len < sizeof(struct packet_mreq))
3034 return -EINVAL;
3035 if (len > sizeof(mreq))
3036 len = sizeof(mreq);
3037 if (copy_from_user(&mreq, optval, len))
3038 return -EFAULT;
3039 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3040 return -EINVAL;
3041 if (optname == PACKET_ADD_MEMBERSHIP)
3042 ret = packet_mc_add(sk, &mreq);
3043 else
3044 ret = packet_mc_drop(sk, &mreq);
3045 return ret;
3046 }
3047
3048 case PACKET_RX_RING:
3049 case PACKET_TX_RING:
3050 {
3051 union tpacket_req_u req_u;
3052 int len;
3053
3054 switch (po->tp_version) {
3055 case TPACKET_V1:
3056 case TPACKET_V2:
3057 len = sizeof(req_u.req);
3058 break;
3059 case TPACKET_V3:
3060 default:
3061 len = sizeof(req_u.req3);
3062 break;
3063 }
3064 if (optlen < len)
3065 return -EINVAL;
3066 if (pkt_sk(sk)->has_vnet_hdr)
3067 return -EINVAL;
3068 if (copy_from_user(&req_u.req, optval, len))
3069 return -EFAULT;
3070 return packet_set_ring(sk, &req_u, 0,
3071 optname == PACKET_TX_RING);
3072 }
3073 case PACKET_COPY_THRESH:
3074 {
3075 int val;
3076
3077 if (optlen != sizeof(val))
3078 return -EINVAL;
3079 if (copy_from_user(&val, optval, sizeof(val)))
3080 return -EFAULT;
3081
3082 pkt_sk(sk)->copy_thresh = val;
3083 return 0;
3084 }
3085 case PACKET_VERSION:
3086 {
3087 int val;
3088
3089 if (optlen != sizeof(val))
3090 return -EINVAL;
3091 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3092 return -EBUSY;
3093 if (copy_from_user(&val, optval, sizeof(val)))
3094 return -EFAULT;
3095 switch (val) {
3096 case TPACKET_V1:
3097 case TPACKET_V2:
3098 case TPACKET_V3:
3099 po->tp_version = val;
3100 return 0;
3101 default:
3102 return -EINVAL;
3103 }
3104 }
3105 case PACKET_RESERVE:
3106 {
3107 unsigned int val;
3108
3109 if (optlen != sizeof(val))
3110 return -EINVAL;
3111 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3112 return -EBUSY;
3113 if (copy_from_user(&val, optval, sizeof(val)))
3114 return -EFAULT;
3115 po->tp_reserve = val;
3116 return 0;
3117 }
3118 case PACKET_LOSS:
3119 {
3120 unsigned int val;
3121
3122 if (optlen != sizeof(val))
3123 return -EINVAL;
3124 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3125 return -EBUSY;
3126 if (copy_from_user(&val, optval, sizeof(val)))
3127 return -EFAULT;
3128 po->tp_loss = !!val;
3129 return 0;
3130 }
3131 case PACKET_AUXDATA:
3132 {
3133 int val;
3134
3135 if (optlen < sizeof(val))
3136 return -EINVAL;
3137 if (copy_from_user(&val, optval, sizeof(val)))
3138 return -EFAULT;
3139
3140 po->auxdata = !!val;
3141 return 0;
3142 }
3143 case PACKET_ORIGDEV:
3144 {
3145 int val;
3146
3147 if (optlen < sizeof(val))
3148 return -EINVAL;
3149 if (copy_from_user(&val, optval, sizeof(val)))
3150 return -EFAULT;
3151
3152 po->origdev = !!val;
3153 return 0;
3154 }
3155 case PACKET_VNET_HDR:
3156 {
3157 int val;
3158
3159 if (sock->type != SOCK_RAW)
3160 return -EINVAL;
3161 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3162 return -EBUSY;
3163 if (optlen < sizeof(val))
3164 return -EINVAL;
3165 if (copy_from_user(&val, optval, sizeof(val)))
3166 return -EFAULT;
3167
3168 po->has_vnet_hdr = !!val;
3169 return 0;
3170 }
3171 case PACKET_TIMESTAMP:
3172 {
3173 int val;
3174
3175 if (optlen != sizeof(val))
3176 return -EINVAL;
3177 if (copy_from_user(&val, optval, sizeof(val)))
3178 return -EFAULT;
3179
3180 po->tp_tstamp = val;
3181 return 0;
3182 }
3183 case PACKET_FANOUT:
3184 {
3185 int val;
3186
3187 if (optlen != sizeof(val))
3188 return -EINVAL;
3189 if (copy_from_user(&val, optval, sizeof(val)))
3190 return -EFAULT;
3191
3192 return fanout_add(sk, val & 0xffff, val >> 16);
3193 }
3194 case PACKET_TX_HAS_OFF:
3195 {
3196 unsigned int val;
3197
3198 if (optlen != sizeof(val))
3199 return -EINVAL;
3200 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3201 return -EBUSY;
3202 if (copy_from_user(&val, optval, sizeof(val)))
3203 return -EFAULT;
3204 po->tp_tx_has_off = !!val;
3205 return 0;
3206 }
3207 default:
3208 return -ENOPROTOOPT;
3209 }
3210 }
3211
3212 static int packet_getsockopt(struct socket *sock, int level, int optname,
3213 char __user *optval, int __user *optlen)
3214 {
3215 int len;
3216 int val, lv = sizeof(val);
3217 struct sock *sk = sock->sk;
3218 struct packet_sock *po = pkt_sk(sk);
3219 void *data = &val;
3220 union tpacket_stats_u st;
3221
3222 if (level != SOL_PACKET)
3223 return -ENOPROTOOPT;
3224
3225 if (get_user(len, optlen))
3226 return -EFAULT;
3227
3228 if (len < 0)
3229 return -EINVAL;
3230
3231 switch (optname) {
3232 case PACKET_STATISTICS:
3233 spin_lock_bh(&sk->sk_receive_queue.lock);
3234 memcpy(&st, &po->stats, sizeof(st));
3235 memset(&po->stats, 0, sizeof(po->stats));
3236 spin_unlock_bh(&sk->sk_receive_queue.lock);
3237
3238 if (po->tp_version == TPACKET_V3) {
3239 lv = sizeof(struct tpacket_stats_v3);
3240 st.stats3.tp_packets += st.stats3.tp_drops;
3241 data = &st.stats3;
3242 } else {
3243 lv = sizeof(struct tpacket_stats);
3244 st.stats1.tp_packets += st.stats1.tp_drops;
3245 data = &st.stats1;
3246 }
3247
3248 break;
3249 case PACKET_AUXDATA:
3250 val = po->auxdata;
3251 break;
3252 case PACKET_ORIGDEV:
3253 val = po->origdev;
3254 break;
3255 case PACKET_VNET_HDR:
3256 val = po->has_vnet_hdr;
3257 break;
3258 case PACKET_VERSION:
3259 val = po->tp_version;
3260 break;
3261 case PACKET_HDRLEN:
3262 if (len > sizeof(int))
3263 len = sizeof(int);
3264 if (copy_from_user(&val, optval, len))
3265 return -EFAULT;
3266 switch (val) {
3267 case TPACKET_V1:
3268 val = sizeof(struct tpacket_hdr);
3269 break;
3270 case TPACKET_V2:
3271 val = sizeof(struct tpacket2_hdr);
3272 break;
3273 case TPACKET_V3:
3274 val = sizeof(struct tpacket3_hdr);
3275 break;
3276 default:
3277 return -EINVAL;
3278 }
3279 break;
3280 case PACKET_RESERVE:
3281 val = po->tp_reserve;
3282 break;
3283 case PACKET_LOSS:
3284 val = po->tp_loss;
3285 break;
3286 case PACKET_TIMESTAMP:
3287 val = po->tp_tstamp;
3288 break;
3289 case PACKET_FANOUT:
3290 val = (po->fanout ?
3291 ((u32)po->fanout->id |
3292 ((u32)po->fanout->type << 16) |
3293 ((u32)po->fanout->flags << 24)) :
3294 0);
3295 break;
3296 case PACKET_TX_HAS_OFF:
3297 val = po->tp_tx_has_off;
3298 break;
3299 default:
3300 return -ENOPROTOOPT;
3301 }
3302
3303 if (len > lv)
3304 len = lv;
3305 if (put_user(len, optlen))
3306 return -EFAULT;
3307 if (copy_to_user(optval, data, len))
3308 return -EFAULT;
3309 return 0;
3310 }
3311
3312
3313 static int packet_notifier(struct notifier_block *this,
3314 unsigned long msg, void *ptr)
3315 {
3316 struct sock *sk;
3317 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3318 struct net *net = dev_net(dev);
3319
3320 rcu_read_lock();
3321 sk_for_each_rcu(sk, &net->packet.sklist) {
3322 struct packet_sock *po = pkt_sk(sk);
3323
3324 switch (msg) {
3325 case NETDEV_UNREGISTER:
3326 if (po->mclist)
3327 packet_dev_mclist(dev, po->mclist, -1);
3328 /* fallthrough */
3329
3330 case NETDEV_DOWN:
3331 if (dev->ifindex == po->ifindex) {
3332 spin_lock(&po->bind_lock);
3333 if (po->running) {
3334 __unregister_prot_hook(sk, false);
3335 sk->sk_err = ENETDOWN;
3336 if (!sock_flag(sk, SOCK_DEAD))
3337 sk->sk_error_report(sk);
3338 }
3339 if (msg == NETDEV_UNREGISTER) {
3340 po->ifindex = -1;
3341 if (po->prot_hook.dev)
3342 dev_put(po->prot_hook.dev);
3343 po->prot_hook.dev = NULL;
3344 }
3345 spin_unlock(&po->bind_lock);
3346 }
3347 break;
3348 case NETDEV_UP:
3349 if (dev->ifindex == po->ifindex) {
3350 spin_lock(&po->bind_lock);
3351 if (po->num)
3352 register_prot_hook(sk);
3353 spin_unlock(&po->bind_lock);
3354 }
3355 break;
3356 }
3357 }
3358 rcu_read_unlock();
3359 return NOTIFY_DONE;
3360 }
3361
3362
3363 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3364 unsigned long arg)
3365 {
3366 struct sock *sk = sock->sk;
3367
3368 switch (cmd) {
3369 case SIOCOUTQ:
3370 {
3371 int amount = sk_wmem_alloc_get(sk);
3372
3373 return put_user(amount, (int __user *)arg);
3374 }
3375 case SIOCINQ:
3376 {
3377 struct sk_buff *skb;
3378 int amount = 0;
3379
3380 spin_lock_bh(&sk->sk_receive_queue.lock);
3381 skb = skb_peek(&sk->sk_receive_queue);
3382 if (skb)
3383 amount = skb->len;
3384 spin_unlock_bh(&sk->sk_receive_queue.lock);
3385 return put_user(amount, (int __user *)arg);
3386 }
3387 case SIOCGSTAMP:
3388 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3389 case SIOCGSTAMPNS:
3390 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3391
3392 #ifdef CONFIG_INET
3393 case SIOCADDRT:
3394 case SIOCDELRT:
3395 case SIOCDARP:
3396 case SIOCGARP:
3397 case SIOCSARP:
3398 case SIOCGIFADDR:
3399 case SIOCSIFADDR:
3400 case SIOCGIFBRDADDR:
3401 case SIOCSIFBRDADDR:
3402 case SIOCGIFNETMASK:
3403 case SIOCSIFNETMASK:
3404 case SIOCGIFDSTADDR:
3405 case SIOCSIFDSTADDR:
3406 case SIOCSIFFLAGS:
3407 return inet_dgram_ops.ioctl(sock, cmd, arg);
3408 #endif
3409
3410 default:
3411 return -ENOIOCTLCMD;
3412 }
3413 return 0;
3414 }
3415
3416 static unsigned int packet_poll(struct file *file, struct socket *sock,
3417 poll_table *wait)
3418 {
3419 struct sock *sk = sock->sk;
3420 struct packet_sock *po = pkt_sk(sk);
3421 unsigned int mask = datagram_poll(file, sock, wait);
3422
3423 spin_lock_bh(&sk->sk_receive_queue.lock);
3424 if (po->rx_ring.pg_vec) {
3425 if (!packet_previous_rx_frame(po, &po->rx_ring,
3426 TP_STATUS_KERNEL))
3427 mask |= POLLIN | POLLRDNORM;
3428 }
3429 spin_unlock_bh(&sk->sk_receive_queue.lock);
3430 spin_lock_bh(&sk->sk_write_queue.lock);
3431 if (po->tx_ring.pg_vec) {
3432 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3433 mask |= POLLOUT | POLLWRNORM;
3434 }
3435 spin_unlock_bh(&sk->sk_write_queue.lock);
3436 return mask;
3437 }
3438
3439
3440 /* Dirty? Well, I still did not learn better way to account
3441 * for user mmaps.
3442 */
3443
3444 static void packet_mm_open(struct vm_area_struct *vma)
3445 {
3446 struct file *file = vma->vm_file;
3447 struct socket *sock = file->private_data;
3448 struct sock *sk = sock->sk;
3449
3450 if (sk)
3451 atomic_inc(&pkt_sk(sk)->mapped);
3452 }
3453
3454 static void packet_mm_close(struct vm_area_struct *vma)
3455 {
3456 struct file *file = vma->vm_file;
3457 struct socket *sock = file->private_data;
3458 struct sock *sk = sock->sk;
3459
3460 if (sk)
3461 atomic_dec(&pkt_sk(sk)->mapped);
3462 }
3463
3464 static const struct vm_operations_struct packet_mmap_ops = {
3465 .open = packet_mm_open,
3466 .close = packet_mm_close,
3467 };
3468
3469 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3470 unsigned int len)
3471 {
3472 int i;
3473
3474 for (i = 0; i < len; i++) {
3475 if (likely(pg_vec[i].buffer)) {
3476 if (is_vmalloc_addr(pg_vec[i].buffer))
3477 vfree(pg_vec[i].buffer);
3478 else
3479 free_pages((unsigned long)pg_vec[i].buffer,
3480 order);
3481 pg_vec[i].buffer = NULL;
3482 }
3483 }
3484 kfree(pg_vec);
3485 }
3486
3487 static char *alloc_one_pg_vec_page(unsigned long order)
3488 {
3489 char *buffer = NULL;
3490 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3491 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3492
3493 buffer = (char *) __get_free_pages(gfp_flags, order);
3494
3495 if (buffer)
3496 return buffer;
3497
3498 /*
3499 * __get_free_pages failed, fall back to vmalloc
3500 */
3501 buffer = vzalloc((1 << order) * PAGE_SIZE);
3502
3503 if (buffer)
3504 return buffer;
3505
3506 /*
3507 * vmalloc failed, lets dig into swap here
3508 */
3509 gfp_flags &= ~__GFP_NORETRY;
3510 buffer = (char *)__get_free_pages(gfp_flags, order);
3511 if (buffer)
3512 return buffer;
3513
3514 /*
3515 * complete and utter failure
3516 */
3517 return NULL;
3518 }
3519
3520 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3521 {
3522 unsigned int block_nr = req->tp_block_nr;
3523 struct pgv *pg_vec;
3524 int i;
3525
3526 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3527 if (unlikely(!pg_vec))
3528 goto out;
3529
3530 for (i = 0; i < block_nr; i++) {
3531 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3532 if (unlikely(!pg_vec[i].buffer))
3533 goto out_free_pgvec;
3534 }
3535
3536 out:
3537 return pg_vec;
3538
3539 out_free_pgvec:
3540 free_pg_vec(pg_vec, order, block_nr);
3541 pg_vec = NULL;
3542 goto out;
3543 }
3544
3545 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3546 int closing, int tx_ring)
3547 {
3548 struct pgv *pg_vec = NULL;
3549 struct packet_sock *po = pkt_sk(sk);
3550 int was_running, order = 0;
3551 struct packet_ring_buffer *rb;
3552 struct sk_buff_head *rb_queue;
3553 __be16 num;
3554 int err = -EINVAL;
3555 /* Added to avoid minimal code churn */
3556 struct tpacket_req *req = &req_u->req;
3557
3558 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3559 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3560 WARN(1, "Tx-ring is not supported.\n");
3561 goto out;
3562 }
3563
3564 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3565 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3566
3567 err = -EBUSY;
3568 if (!closing) {
3569 if (atomic_read(&po->mapped))
3570 goto out;
3571 if (atomic_read(&rb->pending))
3572 goto out;
3573 }
3574
3575 if (req->tp_block_nr) {
3576 /* Sanity tests and some calculations */
3577 err = -EBUSY;
3578 if (unlikely(rb->pg_vec))
3579 goto out;
3580
3581 switch (po->tp_version) {
3582 case TPACKET_V1:
3583 po->tp_hdrlen = TPACKET_HDRLEN;
3584 break;
3585 case TPACKET_V2:
3586 po->tp_hdrlen = TPACKET2_HDRLEN;
3587 break;
3588 case TPACKET_V3:
3589 po->tp_hdrlen = TPACKET3_HDRLEN;
3590 break;
3591 }
3592
3593 err = -EINVAL;
3594 if (unlikely((int)req->tp_block_size <= 0))
3595 goto out;
3596 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3597 goto out;
3598 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3599 po->tp_reserve))
3600 goto out;
3601 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3602 goto out;
3603
3604 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3605 if (unlikely(rb->frames_per_block <= 0))
3606 goto out;
3607 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3608 req->tp_frame_nr))
3609 goto out;
3610
3611 err = -ENOMEM;
3612 order = get_order(req->tp_block_size);
3613 pg_vec = alloc_pg_vec(req, order);
3614 if (unlikely(!pg_vec))
3615 goto out;
3616 switch (po->tp_version) {
3617 case TPACKET_V3:
3618 /* Transmit path is not supported. We checked
3619 * it above but just being paranoid
3620 */
3621 if (!tx_ring)
3622 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3623 break;
3624 default:
3625 break;
3626 }
3627 }
3628 /* Done */
3629 else {
3630 err = -EINVAL;
3631 if (unlikely(req->tp_frame_nr))
3632 goto out;
3633 }
3634
3635 lock_sock(sk);
3636
3637 /* Detach socket from network */
3638 spin_lock(&po->bind_lock);
3639 was_running = po->running;
3640 num = po->num;
3641 if (was_running) {
3642 po->num = 0;
3643 __unregister_prot_hook(sk, false);
3644 }
3645 spin_unlock(&po->bind_lock);
3646
3647 synchronize_net();
3648
3649 err = -EBUSY;
3650 mutex_lock(&po->pg_vec_lock);
3651 if (closing || atomic_read(&po->mapped) == 0) {
3652 err = 0;
3653 spin_lock_bh(&rb_queue->lock);
3654 swap(rb->pg_vec, pg_vec);
3655 rb->frame_max = (req->tp_frame_nr - 1);
3656 rb->head = 0;
3657 rb->frame_size = req->tp_frame_size;
3658 spin_unlock_bh(&rb_queue->lock);
3659
3660 swap(rb->pg_vec_order, order);
3661 swap(rb->pg_vec_len, req->tp_block_nr);
3662
3663 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3664 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3665 tpacket_rcv : packet_rcv;
3666 skb_queue_purge(rb_queue);
3667 if (atomic_read(&po->mapped))
3668 pr_err("packet_mmap: vma is busy: %d\n",
3669 atomic_read(&po->mapped));
3670 }
3671 mutex_unlock(&po->pg_vec_lock);
3672
3673 spin_lock(&po->bind_lock);
3674 if (was_running) {
3675 po->num = num;
3676 register_prot_hook(sk);
3677 }
3678 spin_unlock(&po->bind_lock);
3679 if (closing && (po->tp_version > TPACKET_V2)) {
3680 /* Because we don't support block-based V3 on tx-ring */
3681 if (!tx_ring)
3682 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3683 }
3684 release_sock(sk);
3685
3686 if (pg_vec)
3687 free_pg_vec(pg_vec, order, req->tp_block_nr);
3688 out:
3689 return err;
3690 }
3691
3692 static int packet_mmap(struct file *file, struct socket *sock,
3693 struct vm_area_struct *vma)
3694 {
3695 struct sock *sk = sock->sk;
3696 struct packet_sock *po = pkt_sk(sk);
3697 unsigned long size, expected_size;
3698 struct packet_ring_buffer *rb;
3699 unsigned long start;
3700 int err = -EINVAL;
3701 int i;
3702
3703 if (vma->vm_pgoff)
3704 return -EINVAL;
3705
3706 mutex_lock(&po->pg_vec_lock);
3707
3708 expected_size = 0;
3709 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3710 if (rb->pg_vec) {
3711 expected_size += rb->pg_vec_len
3712 * rb->pg_vec_pages
3713 * PAGE_SIZE;
3714 }
3715 }
3716
3717 if (expected_size == 0)
3718 goto out;
3719
3720 size = vma->vm_end - vma->vm_start;
3721 if (size != expected_size)
3722 goto out;
3723
3724 start = vma->vm_start;
3725 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3726 if (rb->pg_vec == NULL)
3727 continue;
3728
3729 for (i = 0; i < rb->pg_vec_len; i++) {
3730 struct page *page;
3731 void *kaddr = rb->pg_vec[i].buffer;
3732 int pg_num;
3733
3734 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3735 page = pgv_to_page(kaddr);
3736 err = vm_insert_page(vma, start, page);
3737 if (unlikely(err))
3738 goto out;
3739 start += PAGE_SIZE;
3740 kaddr += PAGE_SIZE;
3741 }
3742 }
3743 }
3744
3745 atomic_inc(&po->mapped);
3746 vma->vm_ops = &packet_mmap_ops;
3747 err = 0;
3748
3749 out:
3750 mutex_unlock(&po->pg_vec_lock);
3751 return err;
3752 }
3753
3754 static const struct proto_ops packet_ops_spkt = {
3755 .family = PF_PACKET,
3756 .owner = THIS_MODULE,
3757 .release = packet_release,
3758 .bind = packet_bind_spkt,
3759 .connect = sock_no_connect,
3760 .socketpair = sock_no_socketpair,
3761 .accept = sock_no_accept,
3762 .getname = packet_getname_spkt,
3763 .poll = datagram_poll,
3764 .ioctl = packet_ioctl,
3765 .listen = sock_no_listen,
3766 .shutdown = sock_no_shutdown,
3767 .setsockopt = sock_no_setsockopt,
3768 .getsockopt = sock_no_getsockopt,
3769 .sendmsg = packet_sendmsg_spkt,
3770 .recvmsg = packet_recvmsg,
3771 .mmap = sock_no_mmap,
3772 .sendpage = sock_no_sendpage,
3773 };
3774
3775 static const struct proto_ops packet_ops = {
3776 .family = PF_PACKET,
3777 .owner = THIS_MODULE,
3778 .release = packet_release,
3779 .bind = packet_bind,
3780 .connect = sock_no_connect,
3781 .socketpair = sock_no_socketpair,
3782 .accept = sock_no_accept,
3783 .getname = packet_getname,
3784 .poll = packet_poll,
3785 .ioctl = packet_ioctl,
3786 .listen = sock_no_listen,
3787 .shutdown = sock_no_shutdown,
3788 .setsockopt = packet_setsockopt,
3789 .getsockopt = packet_getsockopt,
3790 .sendmsg = packet_sendmsg,
3791 .recvmsg = packet_recvmsg,
3792 .mmap = packet_mmap,
3793 .sendpage = sock_no_sendpage,
3794 };
3795
3796 static const struct net_proto_family packet_family_ops = {
3797 .family = PF_PACKET,
3798 .create = packet_create,
3799 .owner = THIS_MODULE,
3800 };
3801
3802 static struct notifier_block packet_netdev_notifier = {
3803 .notifier_call = packet_notifier,
3804 };
3805
3806 #ifdef CONFIG_PROC_FS
3807
3808 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3809 __acquires(RCU)
3810 {
3811 struct net *net = seq_file_net(seq);
3812
3813 rcu_read_lock();
3814 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3815 }
3816
3817 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3818 {
3819 struct net *net = seq_file_net(seq);
3820 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3821 }
3822
3823 static void packet_seq_stop(struct seq_file *seq, void *v)
3824 __releases(RCU)
3825 {
3826 rcu_read_unlock();
3827 }
3828
3829 static int packet_seq_show(struct seq_file *seq, void *v)
3830 {
3831 if (v == SEQ_START_TOKEN)
3832 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3833 else {
3834 struct sock *s = sk_entry(v);
3835 const struct packet_sock *po = pkt_sk(s);
3836
3837 seq_printf(seq,
3838 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3839 s,
3840 atomic_read(&s->sk_refcnt),
3841 s->sk_type,
3842 ntohs(po->num),
3843 po->ifindex,
3844 po->running,
3845 atomic_read(&s->sk_rmem_alloc),
3846 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3847 sock_i_ino(s));
3848 }
3849
3850 return 0;
3851 }
3852
3853 static const struct seq_operations packet_seq_ops = {
3854 .start = packet_seq_start,
3855 .next = packet_seq_next,
3856 .stop = packet_seq_stop,
3857 .show = packet_seq_show,
3858 };
3859
3860 static int packet_seq_open(struct inode *inode, struct file *file)
3861 {
3862 return seq_open_net(inode, file, &packet_seq_ops,
3863 sizeof(struct seq_net_private));
3864 }
3865
3866 static const struct file_operations packet_seq_fops = {
3867 .owner = THIS_MODULE,
3868 .open = packet_seq_open,
3869 .read = seq_read,
3870 .llseek = seq_lseek,
3871 .release = seq_release_net,
3872 };
3873
3874 #endif
3875
3876 static int __net_init packet_net_init(struct net *net)
3877 {
3878 mutex_init(&net->packet.sklist_lock);
3879 INIT_HLIST_HEAD(&net->packet.sklist);
3880
3881 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
3882 return -ENOMEM;
3883
3884 return 0;
3885 }
3886
3887 static void __net_exit packet_net_exit(struct net *net)
3888 {
3889 remove_proc_entry("packet", net->proc_net);
3890 }
3891
3892 static struct pernet_operations packet_net_ops = {
3893 .init = packet_net_init,
3894 .exit = packet_net_exit,
3895 };
3896
3897
3898 static void __exit packet_exit(void)
3899 {
3900 unregister_netdevice_notifier(&packet_netdev_notifier);
3901 unregister_pernet_subsys(&packet_net_ops);
3902 sock_unregister(PF_PACKET);
3903 proto_unregister(&packet_proto);
3904 }
3905
3906 static int __init packet_init(void)
3907 {
3908 int rc = proto_register(&packet_proto, 0);
3909
3910 if (rc != 0)
3911 goto out;
3912
3913 sock_register(&packet_family_ops);
3914 register_pernet_subsys(&packet_net_ops);
3915 register_netdevice_notifier(&packet_netdev_notifier);
3916 out:
3917 return rc;
3918 }
3919
3920 module_init(packet_init);
3921 module_exit(packet_exit);
3922 MODULE_LICENSE("GPL");
3923 MODULE_ALIAS_NETPROTO(PF_PACKET);
Linux kernel - Deliverables
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