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net/packet: check length in getsockopt() called with PACKET_HDRLEN
[GitHub/LineageOS/android_kernel_samsung_universal7580.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
92 #ifdef CONFIG_INET
93 #include <net/inet_common.h>
94 #endif
95
96 #include "internal.h"
97
98 /*
99 Assumptions:
100 - if device has no dev->hard_header routine, it adds and removes ll header
101 inside itself. In this case ll header is invisible outside of device,
102 but higher levels still should reserve dev->hard_header_len.
103 Some devices are enough clever to reallocate skb, when header
104 will not fit to reserved space (tunnel), another ones are silly
105 (PPP).
106 - packet socket receives packets with pulled ll header,
107 so that SOCK_RAW should push it back.
108
109 On receive:
110 -----------
111
112 Incoming, dev->hard_header!=NULL
113 mac_header -> ll header
114 data -> data
115
116 Outgoing, dev->hard_header!=NULL
117 mac_header -> ll header
118 data -> ll header
119
120 Incoming, dev->hard_header==NULL
121 mac_header -> UNKNOWN position. It is very likely, that it points to ll
122 header. PPP makes it, that is wrong, because introduce
123 assymetry between rx and tx paths.
124 data -> data
125
126 Outgoing, dev->hard_header==NULL
127 mac_header -> data. ll header is still not built!
128 data -> data
129
130 Resume
131 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
132
133
134 On transmit:
135 ------------
136
137 dev->hard_header != NULL
138 mac_header -> ll header
139 data -> ll header
140
141 dev->hard_header == NULL (ll header is added by device, we cannot control it)
142 mac_header -> data
143 data -> data
144
145 We should set nh.raw on output to correct posistion,
146 packet classifier depends on it.
147 */
148
149 /* Private packet socket structures. */
150
151 /* identical to struct packet_mreq except it has
152 * a longer address field.
153 */
154 struct packet_mreq_max {
155 int mr_ifindex;
156 unsigned short mr_type;
157 unsigned short mr_alen;
158 unsigned char mr_address[MAX_ADDR_LEN];
159 };
160
161 union tpacket_uhdr {
162 struct tpacket_hdr *h1;
163 struct tpacket2_hdr *h2;
164 struct tpacket3_hdr *h3;
165 void *raw;
166 };
167
168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
169 int closing, int tx_ring);
170
171 #define V3_ALIGNMENT (8)
172
173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
174
175 #define BLK_PLUS_PRIV(sz_of_priv) \
176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
177
178 #define PGV_FROM_VMALLOC 1
179
180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
187
188 struct packet_sock;
189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
191 struct packet_type *pt, struct net_device *orig_dev);
192
193 static void *packet_previous_frame(struct packet_sock *po,
194 struct packet_ring_buffer *rb,
195 int status);
196 static void packet_increment_head(struct packet_ring_buffer *buff);
197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
198 struct tpacket_block_desc *);
199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200 struct packet_sock *);
201 static void prb_retire_current_block(struct tpacket_kbdq_core *,
202 struct packet_sock *, unsigned int status);
203 static int prb_queue_frozen(struct tpacket_kbdq_core *);
204 static void prb_open_block(struct tpacket_kbdq_core *,
205 struct tpacket_block_desc *);
206 static void prb_retire_rx_blk_timer_expired(unsigned long);
207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208 static void prb_init_blk_timer(struct packet_sock *,
209 struct tpacket_kbdq_core *,
210 void (*func) (unsigned long));
211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
212 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
213 struct tpacket3_hdr *);
214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
215 struct tpacket3_hdr *);
216 static void packet_flush_mclist(struct sock *sk);
217
218 struct packet_skb_cb {
219 unsigned int origlen;
220 union {
221 struct sockaddr_pkt pkt;
222 struct sockaddr_ll ll;
223 } sa;
224 };
225
226 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
227
228 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
229 #define GET_PBLOCK_DESC(x, bid) \
230 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
232 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
233 #define GET_NEXT_PRB_BLK_NUM(x) \
234 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
235 ((x)->kactive_blk_num+1) : 0)
236
237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
238 static void __fanout_link(struct sock *sk, struct packet_sock *po);
239
240 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
241 {
242 struct net_device *dev;
243
244 rcu_read_lock();
245 dev = rcu_dereference(po->cached_dev);
246 if (likely(dev))
247 dev_hold(dev);
248 rcu_read_unlock();
249
250 return dev;
251 }
252
253 static void packet_cached_dev_assign(struct packet_sock *po,
254 struct net_device *dev)
255 {
256 rcu_assign_pointer(po->cached_dev, dev);
257 }
258
259 static void packet_cached_dev_reset(struct packet_sock *po)
260 {
261 RCU_INIT_POINTER(po->cached_dev, NULL);
262 }
263
264 /* register_prot_hook must be invoked with the po->bind_lock held,
265 * or from a context in which asynchronous accesses to the packet
266 * socket is not possible (packet_create()).
267 */
268 static void register_prot_hook(struct sock *sk)
269 {
270 struct packet_sock *po = pkt_sk(sk);
271
272 if (!po->running) {
273 if (po->fanout)
274 __fanout_link(sk, po);
275 else
276 dev_add_pack(&po->prot_hook);
277
278 sock_hold(sk);
279 po->running = 1;
280 }
281 }
282
283 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
284 * held. If the sync parameter is true, we will temporarily drop
285 * the po->bind_lock and do a synchronize_net to make sure no
286 * asynchronous packet processing paths still refer to the elements
287 * of po->prot_hook. If the sync parameter is false, it is the
288 * callers responsibility to take care of this.
289 */
290 static void __unregister_prot_hook(struct sock *sk, bool sync)
291 {
292 struct packet_sock *po = pkt_sk(sk);
293
294 po->running = 0;
295
296 if (po->fanout)
297 __fanout_unlink(sk, po);
298 else
299 __dev_remove_pack(&po->prot_hook);
300
301 __sock_put(sk);
302
303 if (sync) {
304 spin_unlock(&po->bind_lock);
305 synchronize_net();
306 spin_lock(&po->bind_lock);
307 }
308 }
309
310 static void unregister_prot_hook(struct sock *sk, bool sync)
311 {
312 struct packet_sock *po = pkt_sk(sk);
313
314 if (po->running)
315 __unregister_prot_hook(sk, sync);
316 }
317
318 static inline __pure struct page *pgv_to_page(void *addr)
319 {
320 if (is_vmalloc_addr(addr))
321 return vmalloc_to_page(addr);
322 return virt_to_page(addr);
323 }
324
325 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
326 {
327 union tpacket_uhdr h;
328
329 h.raw = frame;
330 switch (po->tp_version) {
331 case TPACKET_V1:
332 h.h1->tp_status = status;
333 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
334 break;
335 case TPACKET_V2:
336 h.h2->tp_status = status;
337 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
338 break;
339 case TPACKET_V3:
340 default:
341 WARN(1, "TPACKET version not supported.\n");
342 BUG();
343 }
344
345 smp_wmb();
346 }
347
348 static int __packet_get_status(struct packet_sock *po, void *frame)
349 {
350 union tpacket_uhdr h;
351
352 smp_rmb();
353
354 h.raw = frame;
355 switch (po->tp_version) {
356 case TPACKET_V1:
357 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
358 return h.h1->tp_status;
359 case TPACKET_V2:
360 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
361 return h.h2->tp_status;
362 case TPACKET_V3:
363 default:
364 WARN(1, "TPACKET version not supported.\n");
365 BUG();
366 return 0;
367 }
368 }
369
370 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
371 unsigned int flags)
372 {
373 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
374
375 if (shhwtstamps) {
376 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
377 ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
378 return TP_STATUS_TS_SYS_HARDWARE;
379 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
380 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
381 return TP_STATUS_TS_RAW_HARDWARE;
382 }
383
384 if (ktime_to_timespec_cond(skb->tstamp, ts))
385 return TP_STATUS_TS_SOFTWARE;
386
387 return 0;
388 }
389
390 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
391 struct sk_buff *skb)
392 {
393 union tpacket_uhdr h;
394 struct timespec ts;
395 __u32 ts_status;
396
397 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
398 return 0;
399
400 h.raw = frame;
401 switch (po->tp_version) {
402 case TPACKET_V1:
403 h.h1->tp_sec = ts.tv_sec;
404 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
405 break;
406 case TPACKET_V2:
407 h.h2->tp_sec = ts.tv_sec;
408 h.h2->tp_nsec = ts.tv_nsec;
409 break;
410 case TPACKET_V3:
411 default:
412 WARN(1, "TPACKET version not supported.\n");
413 BUG();
414 }
415
416 /* one flush is safe, as both fields always lie on the same cacheline */
417 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
418 smp_wmb();
419
420 return ts_status;
421 }
422
423 static void *packet_lookup_frame(struct packet_sock *po,
424 struct packet_ring_buffer *rb,
425 unsigned int position,
426 int status)
427 {
428 unsigned int pg_vec_pos, frame_offset;
429 union tpacket_uhdr h;
430
431 pg_vec_pos = position / rb->frames_per_block;
432 frame_offset = position % rb->frames_per_block;
433
434 h.raw = rb->pg_vec[pg_vec_pos].buffer +
435 (frame_offset * rb->frame_size);
436
437 if (status != __packet_get_status(po, h.raw))
438 return NULL;
439
440 return h.raw;
441 }
442
443 static void *packet_current_frame(struct packet_sock *po,
444 struct packet_ring_buffer *rb,
445 int status)
446 {
447 return packet_lookup_frame(po, rb, rb->head, status);
448 }
449
450 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
451 {
452 del_timer_sync(&pkc->retire_blk_timer);
453 }
454
455 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
456 int tx_ring,
457 struct sk_buff_head *rb_queue)
458 {
459 struct tpacket_kbdq_core *pkc;
460
461 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
462
463 spin_lock_bh(&rb_queue->lock);
464 pkc->delete_blk_timer = 1;
465 spin_unlock_bh(&rb_queue->lock);
466
467 prb_del_retire_blk_timer(pkc);
468 }
469
470 static void prb_init_blk_timer(struct packet_sock *po,
471 struct tpacket_kbdq_core *pkc,
472 void (*func) (unsigned long))
473 {
474 init_timer(&pkc->retire_blk_timer);
475 pkc->retire_blk_timer.data = (long)po;
476 pkc->retire_blk_timer.function = func;
477 pkc->retire_blk_timer.expires = jiffies;
478 }
479
480 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
481 {
482 struct tpacket_kbdq_core *pkc;
483
484 if (tx_ring)
485 BUG();
486
487 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
488 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
489 }
490
491 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
492 int blk_size_in_bytes)
493 {
494 struct net_device *dev;
495 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
496 struct ethtool_cmd ecmd;
497 int err;
498 u32 speed;
499
500 rtnl_lock();
501 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
502 if (unlikely(!dev)) {
503 rtnl_unlock();
504 return DEFAULT_PRB_RETIRE_TOV;
505 }
506 err = __ethtool_get_settings(dev, &ecmd);
507 speed = ethtool_cmd_speed(&ecmd);
508 rtnl_unlock();
509 if (!err) {
510 /*
511 * If the link speed is so slow you don't really
512 * need to worry about perf anyways
513 */
514 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
515 return DEFAULT_PRB_RETIRE_TOV;
516 } else {
517 msec = 1;
518 div = speed / 1000;
519 }
520 }
521
522 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
523
524 if (div)
525 mbits /= div;
526
527 tmo = mbits * msec;
528
529 if (div)
530 return tmo+1;
531 return tmo;
532 }
533
534 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
535 union tpacket_req_u *req_u)
536 {
537 p1->feature_req_word = req_u->req3.tp_feature_req_word;
538 }
539
540 static void init_prb_bdqc(struct packet_sock *po,
541 struct packet_ring_buffer *rb,
542 struct pgv *pg_vec,
543 union tpacket_req_u *req_u, int tx_ring)
544 {
545 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
546 struct tpacket_block_desc *pbd;
547
548 memset(p1, 0x0, sizeof(*p1));
549
550 p1->knxt_seq_num = 1;
551 p1->pkbdq = pg_vec;
552 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
553 p1->pkblk_start = pg_vec[0].buffer;
554 p1->kblk_size = req_u->req3.tp_block_size;
555 p1->knum_blocks = req_u->req3.tp_block_nr;
556 p1->hdrlen = po->tp_hdrlen;
557 p1->version = po->tp_version;
558 p1->last_kactive_blk_num = 0;
559 po->stats.stats3.tp_freeze_q_cnt = 0;
560 if (req_u->req3.tp_retire_blk_tov)
561 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
562 else
563 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
564 req_u->req3.tp_block_size);
565 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
566 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
567
568 p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
569 prb_init_ft_ops(p1, req_u);
570 prb_setup_retire_blk_timer(po, tx_ring);
571 prb_open_block(p1, pbd);
572 }
573
574 /* Do NOT update the last_blk_num first.
575 * Assumes sk_buff_head lock is held.
576 */
577 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
578 {
579 mod_timer(&pkc->retire_blk_timer,
580 jiffies + pkc->tov_in_jiffies);
581 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
582 }
583
584 /*
585 * Timer logic:
586 * 1) We refresh the timer only when we open a block.
587 * By doing this we don't waste cycles refreshing the timer
588 * on packet-by-packet basis.
589 *
590 * With a 1MB block-size, on a 1Gbps line, it will take
591 * i) ~8 ms to fill a block + ii) memcpy etc.
592 * In this cut we are not accounting for the memcpy time.
593 *
594 * So, if the user sets the 'tmo' to 10ms then the timer
595 * will never fire while the block is still getting filled
596 * (which is what we want). However, the user could choose
597 * to close a block early and that's fine.
598 *
599 * But when the timer does fire, we check whether or not to refresh it.
600 * Since the tmo granularity is in msecs, it is not too expensive
601 * to refresh the timer, lets say every '8' msecs.
602 * Either the user can set the 'tmo' or we can derive it based on
603 * a) line-speed and b) block-size.
604 * prb_calc_retire_blk_tmo() calculates the tmo.
605 *
606 */
607 static void prb_retire_rx_blk_timer_expired(unsigned long data)
608 {
609 struct packet_sock *po = (struct packet_sock *)data;
610 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
611 unsigned int frozen;
612 struct tpacket_block_desc *pbd;
613
614 spin_lock(&po->sk.sk_receive_queue.lock);
615
616 frozen = prb_queue_frozen(pkc);
617 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
618
619 if (unlikely(pkc->delete_blk_timer))
620 goto out;
621
622 /* We only need to plug the race when the block is partially filled.
623 * tpacket_rcv:
624 * lock(); increment BLOCK_NUM_PKTS; unlock()
625 * copy_bits() is in progress ...
626 * timer fires on other cpu:
627 * we can't retire the current block because copy_bits
628 * is in progress.
629 *
630 */
631 if (BLOCK_NUM_PKTS(pbd)) {
632 while (atomic_read(&pkc->blk_fill_in_prog)) {
633 /* Waiting for skb_copy_bits to finish... */
634 cpu_relax();
635 }
636 }
637
638 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
639 if (!frozen) {
640 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
641 if (!prb_dispatch_next_block(pkc, po))
642 goto refresh_timer;
643 else
644 goto out;
645 } else {
646 /* Case 1. Queue was frozen because user-space was
647 * lagging behind.
648 */
649 if (prb_curr_blk_in_use(pkc, pbd)) {
650 /*
651 * Ok, user-space is still behind.
652 * So just refresh the timer.
653 */
654 goto refresh_timer;
655 } else {
656 /* Case 2. queue was frozen,user-space caught up,
657 * now the link went idle && the timer fired.
658 * We don't have a block to close.So we open this
659 * block and restart the timer.
660 * opening a block thaws the queue,restarts timer
661 * Thawing/timer-refresh is a side effect.
662 */
663 prb_open_block(pkc, pbd);
664 goto out;
665 }
666 }
667 }
668
669 refresh_timer:
670 _prb_refresh_rx_retire_blk_timer(pkc);
671
672 out:
673 spin_unlock(&po->sk.sk_receive_queue.lock);
674 }
675
676 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
677 struct tpacket_block_desc *pbd1, __u32 status)
678 {
679 /* Flush everything minus the block header */
680
681 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
682 u8 *start, *end;
683
684 start = (u8 *)pbd1;
685
686 /* Skip the block header(we know header WILL fit in 4K) */
687 start += PAGE_SIZE;
688
689 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
690 for (; start < end; start += PAGE_SIZE)
691 flush_dcache_page(pgv_to_page(start));
692
693 smp_wmb();
694 #endif
695
696 /* Now update the block status. */
697
698 BLOCK_STATUS(pbd1) = status;
699
700 /* Flush the block header */
701
702 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
703 start = (u8 *)pbd1;
704 flush_dcache_page(pgv_to_page(start));
705
706 smp_wmb();
707 #endif
708 }
709
710 /*
711 * Side effect:
712 *
713 * 1) flush the block
714 * 2) Increment active_blk_num
715 *
716 * Note:We DONT refresh the timer on purpose.
717 * Because almost always the next block will be opened.
718 */
719 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
720 struct tpacket_block_desc *pbd1,
721 struct packet_sock *po, unsigned int stat)
722 {
723 __u32 status = TP_STATUS_USER | stat;
724
725 struct tpacket3_hdr *last_pkt;
726 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
727
728 if (po->stats.stats3.tp_drops)
729 status |= TP_STATUS_LOSING;
730
731 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
732 last_pkt->tp_next_offset = 0;
733
734 /* Get the ts of the last pkt */
735 if (BLOCK_NUM_PKTS(pbd1)) {
736 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
737 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
738 } else {
739 /* Ok, we tmo'd - so get the current time */
740 struct timespec ts;
741 getnstimeofday(&ts);
742 h1->ts_last_pkt.ts_sec = ts.tv_sec;
743 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
744 }
745
746 smp_wmb();
747
748 /* Flush the block */
749 prb_flush_block(pkc1, pbd1, status);
750
751 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
752 }
753
754 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
755 {
756 pkc->reset_pending_on_curr_blk = 0;
757 }
758
759 /*
760 * Side effect of opening a block:
761 *
762 * 1) prb_queue is thawed.
763 * 2) retire_blk_timer is refreshed.
764 *
765 */
766 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
767 struct tpacket_block_desc *pbd1)
768 {
769 struct timespec ts;
770 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
771
772 smp_rmb();
773
774 /* We could have just memset this but we will lose the
775 * flexibility of making the priv area sticky
776 */
777
778 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
779 BLOCK_NUM_PKTS(pbd1) = 0;
780 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
781
782 getnstimeofday(&ts);
783
784 h1->ts_first_pkt.ts_sec = ts.tv_sec;
785 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
786
787 pkc1->pkblk_start = (char *)pbd1;
788 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
789
790 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
791 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
792
793 pbd1->version = pkc1->version;
794 pkc1->prev = pkc1->nxt_offset;
795 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
796
797 prb_thaw_queue(pkc1);
798 _prb_refresh_rx_retire_blk_timer(pkc1);
799
800 smp_wmb();
801 }
802
803 /*
804 * Queue freeze logic:
805 * 1) Assume tp_block_nr = 8 blocks.
806 * 2) At time 't0', user opens Rx ring.
807 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
808 * 4) user-space is either sleeping or processing block '0'.
809 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
810 * it will close block-7,loop around and try to fill block '0'.
811 * call-flow:
812 * __packet_lookup_frame_in_block
813 * prb_retire_current_block()
814 * prb_dispatch_next_block()
815 * |->(BLOCK_STATUS == USER) evaluates to true
816 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
817 * 6) Now there are two cases:
818 * 6.1) Link goes idle right after the queue is frozen.
819 * But remember, the last open_block() refreshed the timer.
820 * When this timer expires,it will refresh itself so that we can
821 * re-open block-0 in near future.
822 * 6.2) Link is busy and keeps on receiving packets. This is a simple
823 * case and __packet_lookup_frame_in_block will check if block-0
824 * is free and can now be re-used.
825 */
826 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
827 struct packet_sock *po)
828 {
829 pkc->reset_pending_on_curr_blk = 1;
830 po->stats.stats3.tp_freeze_q_cnt++;
831 }
832
833 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
834
835 /*
836 * If the next block is free then we will dispatch it
837 * and return a good offset.
838 * Else, we will freeze the queue.
839 * So, caller must check the return value.
840 */
841 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
842 struct packet_sock *po)
843 {
844 struct tpacket_block_desc *pbd;
845
846 smp_rmb();
847
848 /* 1. Get current block num */
849 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
850
851 /* 2. If this block is currently in_use then freeze the queue */
852 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
853 prb_freeze_queue(pkc, po);
854 return NULL;
855 }
856
857 /*
858 * 3.
859 * open this block and return the offset where the first packet
860 * needs to get stored.
861 */
862 prb_open_block(pkc, pbd);
863 return (void *)pkc->nxt_offset;
864 }
865
866 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
867 struct packet_sock *po, unsigned int status)
868 {
869 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
870
871 /* retire/close the current block */
872 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
873 /*
874 * Plug the case where copy_bits() is in progress on
875 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
876 * have space to copy the pkt in the current block and
877 * called prb_retire_current_block()
878 *
879 * We don't need to worry about the TMO case because
880 * the timer-handler already handled this case.
881 */
882 if (!(status & TP_STATUS_BLK_TMO)) {
883 while (atomic_read(&pkc->blk_fill_in_prog)) {
884 /* Waiting for skb_copy_bits to finish... */
885 cpu_relax();
886 }
887 }
888 prb_close_block(pkc, pbd, po, status);
889 return;
890 }
891 }
892
893 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
894 struct tpacket_block_desc *pbd)
895 {
896 return TP_STATUS_USER & BLOCK_STATUS(pbd);
897 }
898
899 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
900 {
901 return pkc->reset_pending_on_curr_blk;
902 }
903
904 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
905 {
906 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
907 atomic_dec(&pkc->blk_fill_in_prog);
908 }
909
910 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
911 struct tpacket3_hdr *ppd)
912 {
913 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
914 }
915
916 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
917 struct tpacket3_hdr *ppd)
918 {
919 ppd->hv1.tp_rxhash = 0;
920 }
921
922 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
923 struct tpacket3_hdr *ppd)
924 {
925 if (vlan_tx_tag_present(pkc->skb)) {
926 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
927 ppd->tp_status = TP_STATUS_VLAN_VALID;
928 } else {
929 ppd->hv1.tp_vlan_tci = 0;
930 ppd->tp_status = TP_STATUS_AVAILABLE;
931 }
932 }
933
934 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
935 struct tpacket3_hdr *ppd)
936 {
937 prb_fill_vlan_info(pkc, ppd);
938
939 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
940 prb_fill_rxhash(pkc, ppd);
941 else
942 prb_clear_rxhash(pkc, ppd);
943 }
944
945 static void prb_fill_curr_block(char *curr,
946 struct tpacket_kbdq_core *pkc,
947 struct tpacket_block_desc *pbd,
948 unsigned int len)
949 {
950 struct tpacket3_hdr *ppd;
951
952 ppd = (struct tpacket3_hdr *)curr;
953 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
954 pkc->prev = curr;
955 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
956 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
957 BLOCK_NUM_PKTS(pbd) += 1;
958 atomic_inc(&pkc->blk_fill_in_prog);
959 prb_run_all_ft_ops(pkc, ppd);
960 }
961
962 /* Assumes caller has the sk->rx_queue.lock */
963 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
964 struct sk_buff *skb,
965 int status,
966 unsigned int len
967 )
968 {
969 struct tpacket_kbdq_core *pkc;
970 struct tpacket_block_desc *pbd;
971 char *curr, *end;
972
973 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
974 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
975
976 /* Queue is frozen when user space is lagging behind */
977 if (prb_queue_frozen(pkc)) {
978 /*
979 * Check if that last block which caused the queue to freeze,
980 * is still in_use by user-space.
981 */
982 if (prb_curr_blk_in_use(pkc, pbd)) {
983 /* Can't record this packet */
984 return NULL;
985 } else {
986 /*
987 * Ok, the block was released by user-space.
988 * Now let's open that block.
989 * opening a block also thaws the queue.
990 * Thawing is a side effect.
991 */
992 prb_open_block(pkc, pbd);
993 }
994 }
995
996 smp_mb();
997 curr = pkc->nxt_offset;
998 pkc->skb = skb;
999 end = (char *)pbd + pkc->kblk_size;
1000
1001 /* first try the current block */
1002 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1003 prb_fill_curr_block(curr, pkc, pbd, len);
1004 return (void *)curr;
1005 }
1006
1007 /* Ok, close the current block */
1008 prb_retire_current_block(pkc, po, 0);
1009
1010 /* Now, try to dispatch the next block */
1011 curr = (char *)prb_dispatch_next_block(pkc, po);
1012 if (curr) {
1013 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1014 prb_fill_curr_block(curr, pkc, pbd, len);
1015 return (void *)curr;
1016 }
1017
1018 /*
1019 * No free blocks are available.user_space hasn't caught up yet.
1020 * Queue was just frozen and now this packet will get dropped.
1021 */
1022 return NULL;
1023 }
1024
1025 static void *packet_current_rx_frame(struct packet_sock *po,
1026 struct sk_buff *skb,
1027 int status, unsigned int len)
1028 {
1029 char *curr = NULL;
1030 switch (po->tp_version) {
1031 case TPACKET_V1:
1032 case TPACKET_V2:
1033 curr = packet_lookup_frame(po, &po->rx_ring,
1034 po->rx_ring.head, status);
1035 return curr;
1036 case TPACKET_V3:
1037 return __packet_lookup_frame_in_block(po, skb, status, len);
1038 default:
1039 WARN(1, "TPACKET version not supported\n");
1040 BUG();
1041 return NULL;
1042 }
1043 }
1044
1045 static void *prb_lookup_block(struct packet_sock *po,
1046 struct packet_ring_buffer *rb,
1047 unsigned int idx,
1048 int status)
1049 {
1050 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1051 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1052
1053 if (status != BLOCK_STATUS(pbd))
1054 return NULL;
1055 return pbd;
1056 }
1057
1058 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1059 {
1060 unsigned int prev;
1061 if (rb->prb_bdqc.kactive_blk_num)
1062 prev = rb->prb_bdqc.kactive_blk_num-1;
1063 else
1064 prev = rb->prb_bdqc.knum_blocks-1;
1065 return prev;
1066 }
1067
1068 /* Assumes caller has held the rx_queue.lock */
1069 static void *__prb_previous_block(struct packet_sock *po,
1070 struct packet_ring_buffer *rb,
1071 int status)
1072 {
1073 unsigned int previous = prb_previous_blk_num(rb);
1074 return prb_lookup_block(po, rb, previous, status);
1075 }
1076
1077 static void *packet_previous_rx_frame(struct packet_sock *po,
1078 struct packet_ring_buffer *rb,
1079 int status)
1080 {
1081 if (po->tp_version <= TPACKET_V2)
1082 return packet_previous_frame(po, rb, status);
1083
1084 return __prb_previous_block(po, rb, status);
1085 }
1086
1087 static void packet_increment_rx_head(struct packet_sock *po,
1088 struct packet_ring_buffer *rb)
1089 {
1090 switch (po->tp_version) {
1091 case TPACKET_V1:
1092 case TPACKET_V2:
1093 return packet_increment_head(rb);
1094 case TPACKET_V3:
1095 default:
1096 WARN(1, "TPACKET version not supported.\n");
1097 BUG();
1098 return;
1099 }
1100 }
1101
1102 static void *packet_previous_frame(struct packet_sock *po,
1103 struct packet_ring_buffer *rb,
1104 int status)
1105 {
1106 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1107 return packet_lookup_frame(po, rb, previous, status);
1108 }
1109
1110 static void packet_increment_head(struct packet_ring_buffer *buff)
1111 {
1112 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1113 }
1114
1115 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1116 {
1117 struct sock *sk = &po->sk;
1118 bool has_room;
1119
1120 if (po->prot_hook.func != tpacket_rcv)
1121 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
1122 <= sk->sk_rcvbuf;
1123
1124 spin_lock(&sk->sk_receive_queue.lock);
1125 if (po->tp_version == TPACKET_V3)
1126 has_room = prb_lookup_block(po, &po->rx_ring,
1127 po->rx_ring.prb_bdqc.kactive_blk_num,
1128 TP_STATUS_KERNEL);
1129 else
1130 has_room = packet_lookup_frame(po, &po->rx_ring,
1131 po->rx_ring.head,
1132 TP_STATUS_KERNEL);
1133 spin_unlock(&sk->sk_receive_queue.lock);
1134
1135 return has_room;
1136 }
1137
1138 static void packet_sock_destruct(struct sock *sk)
1139 {
1140 skb_queue_purge(&sk->sk_error_queue);
1141
1142 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1143 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1144
1145 if (!sock_flag(sk, SOCK_DEAD)) {
1146 pr_err("Attempt to release alive packet socket: %p\n", sk);
1147 return;
1148 }
1149
1150 sk_refcnt_debug_dec(sk);
1151 }
1152
1153 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1154 struct sk_buff *skb,
1155 unsigned int num)
1156 {
1157 return (((u64)skb->rxhash) * num) >> 32;
1158 }
1159
1160 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1161 struct sk_buff *skb,
1162 unsigned int num)
1163 {
1164 unsigned int val = atomic_inc_return(&f->rr_cur);
1165
1166 return val % num;
1167 }
1168
1169 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1170 struct sk_buff *skb,
1171 unsigned int num)
1172 {
1173 return smp_processor_id() % num;
1174 }
1175
1176 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1177 struct sk_buff *skb,
1178 unsigned int idx, unsigned int skip,
1179 unsigned int num)
1180 {
1181 unsigned int i, j;
1182
1183 i = j = min_t(int, f->next[idx], num - 1);
1184 do {
1185 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1186 if (i != j)
1187 f->next[idx] = i;
1188 return i;
1189 }
1190 if (++i == num)
1191 i = 0;
1192 } while (i != j);
1193
1194 return idx;
1195 }
1196
1197 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1198 {
1199 return f->flags & (flag >> 8);
1200 }
1201
1202 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1203 struct packet_type *pt, struct net_device *orig_dev)
1204 {
1205 struct packet_fanout *f = pt->af_packet_priv;
1206 unsigned int num = ACCESS_ONCE(f->num_members);
1207 struct packet_sock *po;
1208 unsigned int idx;
1209
1210 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1211 !num) {
1212 kfree_skb(skb);
1213 return 0;
1214 }
1215
1216 switch (f->type) {
1217 case PACKET_FANOUT_HASH:
1218 default:
1219 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1220 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1221 if (!skb)
1222 return 0;
1223 }
1224 skb_get_rxhash(skb);
1225 idx = fanout_demux_hash(f, skb, num);
1226 break;
1227 case PACKET_FANOUT_LB:
1228 idx = fanout_demux_lb(f, skb, num);
1229 break;
1230 case PACKET_FANOUT_CPU:
1231 idx = fanout_demux_cpu(f, skb, num);
1232 break;
1233 case PACKET_FANOUT_ROLLOVER:
1234 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1235 break;
1236 }
1237
1238 po = pkt_sk(f->arr[idx]);
1239 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1240 unlikely(!packet_rcv_has_room(po, skb))) {
1241 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1242 po = pkt_sk(f->arr[idx]);
1243 }
1244
1245 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1246 }
1247
1248 DEFINE_MUTEX(fanout_mutex);
1249 EXPORT_SYMBOL_GPL(fanout_mutex);
1250 static LIST_HEAD(fanout_list);
1251
1252 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1253 {
1254 struct packet_fanout *f = po->fanout;
1255
1256 spin_lock(&f->lock);
1257 f->arr[f->num_members] = sk;
1258 smp_wmb();
1259 f->num_members++;
1260 if (f->num_members == 1)
1261 dev_add_pack(&f->prot_hook);
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 if (f->num_members == 0)
1279 __dev_remove_pack(&f->prot_hook);
1280 spin_unlock(&f->lock);
1281 }
1282
1283 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1284 {
1285 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1286 return true;
1287
1288 return false;
1289 }
1290
1291 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1292 {
1293 struct packet_sock *po = pkt_sk(sk);
1294 struct packet_fanout *f, *match;
1295 u8 type = type_flags & 0xff;
1296 u8 flags = type_flags >> 8;
1297 int err;
1298
1299 switch (type) {
1300 case PACKET_FANOUT_ROLLOVER:
1301 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1302 return -EINVAL;
1303 case PACKET_FANOUT_HASH:
1304 case PACKET_FANOUT_LB:
1305 case PACKET_FANOUT_CPU:
1306 break;
1307 default:
1308 return -EINVAL;
1309 }
1310
1311 mutex_lock(&fanout_mutex);
1312
1313 err = -EINVAL;
1314 if (!po->running)
1315 goto out;
1316
1317 err = -EALREADY;
1318 if (po->fanout)
1319 goto out;
1320
1321 match = NULL;
1322 list_for_each_entry(f, &fanout_list, list) {
1323 if (f->id == id &&
1324 read_pnet(&f->net) == sock_net(sk)) {
1325 match = f;
1326 break;
1327 }
1328 }
1329 err = -EINVAL;
1330 if (match && match->flags != flags)
1331 goto out;
1332 if (!match) {
1333 err = -ENOMEM;
1334 match = kzalloc(sizeof(*match), GFP_KERNEL);
1335 if (!match)
1336 goto out;
1337 write_pnet(&match->net, sock_net(sk));
1338 match->id = id;
1339 match->type = type;
1340 match->flags = flags;
1341 atomic_set(&match->rr_cur, 0);
1342 INIT_LIST_HEAD(&match->list);
1343 spin_lock_init(&match->lock);
1344 atomic_set(&match->sk_ref, 0);
1345 match->prot_hook.type = po->prot_hook.type;
1346 match->prot_hook.dev = po->prot_hook.dev;
1347 match->prot_hook.func = packet_rcv_fanout;
1348 match->prot_hook.af_packet_priv = match;
1349 match->prot_hook.id_match = match_fanout_group;
1350 list_add(&match->list, &fanout_list);
1351 }
1352 err = -EINVAL;
1353
1354 spin_lock(&po->bind_lock);
1355 if (po->running &&
1356 match->type == type &&
1357 match->prot_hook.type == po->prot_hook.type &&
1358 match->prot_hook.dev == po->prot_hook.dev) {
1359 err = -ENOSPC;
1360 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1361 __dev_remove_pack(&po->prot_hook);
1362 po->fanout = match;
1363 atomic_inc(&match->sk_ref);
1364 __fanout_link(sk, po);
1365 err = 0;
1366 }
1367 }
1368 spin_unlock(&po->bind_lock);
1369
1370 if (err && !atomic_read(&match->sk_ref)) {
1371 list_del(&match->list);
1372 kfree(match);
1373 }
1374
1375 out:
1376 mutex_unlock(&fanout_mutex);
1377 return err;
1378 }
1379
1380 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1381 * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1382 * It is the responsibility of the caller to call fanout_release_data() and
1383 * free the returned packet_fanout (after synchronize_net())
1384 */
1385 static struct packet_fanout *fanout_release(struct sock *sk)
1386 {
1387 struct packet_sock *po = pkt_sk(sk);
1388 struct packet_fanout *f;
1389
1390 mutex_lock(&fanout_mutex);
1391 f = po->fanout;
1392 if (f) {
1393 po->fanout = NULL;
1394
1395 if (atomic_dec_and_test(&f->sk_ref))
1396 list_del(&f->list);
1397 else
1398 f = NULL;
1399 }
1400 mutex_unlock(&fanout_mutex);
1401
1402 return f;
1403 }
1404
1405 static const struct proto_ops packet_ops;
1406
1407 static const struct proto_ops packet_ops_spkt;
1408
1409 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1410 struct packet_type *pt, struct net_device *orig_dev)
1411 {
1412 struct sock *sk;
1413 struct sockaddr_pkt *spkt;
1414
1415 /*
1416 * When we registered the protocol we saved the socket in the data
1417 * field for just this event.
1418 */
1419
1420 sk = pt->af_packet_priv;
1421
1422 /*
1423 * Yank back the headers [hope the device set this
1424 * right or kerboom...]
1425 *
1426 * Incoming packets have ll header pulled,
1427 * push it back.
1428 *
1429 * For outgoing ones skb->data == skb_mac_header(skb)
1430 * so that this procedure is noop.
1431 */
1432
1433 if (skb->pkt_type == PACKET_LOOPBACK)
1434 goto out;
1435
1436 if (!net_eq(dev_net(dev), sock_net(sk)))
1437 goto out;
1438
1439 skb = skb_share_check(skb, GFP_ATOMIC);
1440 if (skb == NULL)
1441 goto oom;
1442
1443 /* drop any routing info */
1444 skb_dst_drop(skb);
1445
1446 /* drop conntrack reference */
1447 nf_reset(skb);
1448
1449 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1450
1451 skb_push(skb, skb->data - skb_mac_header(skb));
1452
1453 /*
1454 * The SOCK_PACKET socket receives _all_ frames.
1455 */
1456
1457 spkt->spkt_family = dev->type;
1458 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1459 spkt->spkt_protocol = skb->protocol;
1460
1461 /*
1462 * Charge the memory to the socket. This is done specifically
1463 * to prevent sockets using all the memory up.
1464 */
1465
1466 if (sock_queue_rcv_skb(sk, skb) == 0)
1467 return 0;
1468
1469 out:
1470 kfree_skb(skb);
1471 oom:
1472 return 0;
1473 }
1474
1475
1476 /*
1477 * Output a raw packet to a device layer. This bypasses all the other
1478 * protocol layers and you must therefore supply it with a complete frame
1479 */
1480
1481 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1482 struct msghdr *msg, size_t len)
1483 {
1484 struct sock *sk = sock->sk;
1485 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1486 struct sk_buff *skb = NULL;
1487 struct net_device *dev;
1488 __be16 proto = 0;
1489 int err;
1490 int extra_len = 0;
1491
1492 /*
1493 * Get and verify the address.
1494 */
1495
1496 if (saddr) {
1497 if (msg->msg_namelen < sizeof(struct sockaddr))
1498 return -EINVAL;
1499 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1500 proto = saddr->spkt_protocol;
1501 } else
1502 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1503
1504 /*
1505 * Find the device first to size check it
1506 */
1507
1508 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1509 retry:
1510 rcu_read_lock();
1511 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1512 err = -ENODEV;
1513 if (dev == NULL)
1514 goto out_unlock;
1515
1516 err = -ENETDOWN;
1517 if (!(dev->flags & IFF_UP))
1518 goto out_unlock;
1519
1520 /*
1521 * You may not queue a frame bigger than the mtu. This is the lowest level
1522 * raw protocol and you must do your own fragmentation at this level.
1523 */
1524
1525 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1526 if (!netif_supports_nofcs(dev)) {
1527 err = -EPROTONOSUPPORT;
1528 goto out_unlock;
1529 }
1530 extra_len = 4; /* We're doing our own CRC */
1531 }
1532
1533 err = -EMSGSIZE;
1534 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1535 goto out_unlock;
1536
1537 if (!skb) {
1538 size_t reserved = LL_RESERVED_SPACE(dev);
1539 int tlen = dev->needed_tailroom;
1540 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1541
1542 rcu_read_unlock();
1543 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1544 if (skb == NULL)
1545 return -ENOBUFS;
1546 /* FIXME: Save some space for broken drivers that write a hard
1547 * header at transmission time by themselves. PPP is the notable
1548 * one here. This should really be fixed at the driver level.
1549 */
1550 skb_reserve(skb, reserved);
1551 skb_reset_network_header(skb);
1552
1553 /* Try to align data part correctly */
1554 if (hhlen) {
1555 skb->data -= hhlen;
1556 skb->tail -= hhlen;
1557 if (len < hhlen)
1558 skb_reset_network_header(skb);
1559 }
1560 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1561 if (err)
1562 goto out_free;
1563 goto retry;
1564 }
1565
1566 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1567 /* Earlier code assumed this would be a VLAN pkt,
1568 * double-check this now that we have the actual
1569 * packet in hand.
1570 */
1571 struct ethhdr *ehdr;
1572 skb_reset_mac_header(skb);
1573 ehdr = eth_hdr(skb);
1574 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1575 err = -EMSGSIZE;
1576 goto out_unlock;
1577 }
1578 }
1579
1580 skb->protocol = proto;
1581 skb->dev = dev;
1582 skb->priority = sk->sk_priority;
1583 skb->mark = sk->sk_mark;
1584
1585 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1586
1587 if (unlikely(extra_len == 4))
1588 skb->no_fcs = 1;
1589
1590 skb_probe_transport_header(skb, 0);
1591
1592 dev_queue_xmit(skb);
1593 rcu_read_unlock();
1594 return len;
1595
1596 out_unlock:
1597 rcu_read_unlock();
1598 out_free:
1599 kfree_skb(skb);
1600 return err;
1601 }
1602
1603 static unsigned int run_filter(const struct sk_buff *skb,
1604 const struct sock *sk,
1605 unsigned int res)
1606 {
1607 struct sk_filter *filter;
1608
1609 rcu_read_lock();
1610 filter = rcu_dereference(sk->sk_filter);
1611 if (filter != NULL)
1612 res = SK_RUN_FILTER(filter, skb);
1613 rcu_read_unlock();
1614
1615 return res;
1616 }
1617
1618 /*
1619 * This function makes lazy skb cloning in hope that most of packets
1620 * are discarded by BPF.
1621 *
1622 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1623 * and skb->cb are mangled. It works because (and until) packets
1624 * falling here are owned by current CPU. Output packets are cloned
1625 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1626 * sequencially, so that if we return skb to original state on exit,
1627 * we will not harm anyone.
1628 */
1629
1630 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1631 struct packet_type *pt, struct net_device *orig_dev)
1632 {
1633 struct sock *sk;
1634 struct sockaddr_ll *sll;
1635 struct packet_sock *po;
1636 u8 *skb_head = skb->data;
1637 int skb_len = skb->len;
1638 unsigned int snaplen, res;
1639
1640 if (skb->pkt_type == PACKET_LOOPBACK)
1641 goto drop;
1642
1643 sk = pt->af_packet_priv;
1644 po = pkt_sk(sk);
1645
1646 if (!net_eq(dev_net(dev), sock_net(sk)))
1647 goto drop;
1648
1649 skb->dev = dev;
1650
1651 if (dev->header_ops) {
1652 /* The device has an explicit notion of ll header,
1653 * exported to higher levels.
1654 *
1655 * Otherwise, the device hides details of its frame
1656 * structure, so that corresponding packet head is
1657 * never delivered to user.
1658 */
1659 if (sk->sk_type != SOCK_DGRAM)
1660 skb_push(skb, skb->data - skb_mac_header(skb));
1661 else if (skb->pkt_type == PACKET_OUTGOING) {
1662 /* Special case: outgoing packets have ll header at head */
1663 skb_pull(skb, skb_network_offset(skb));
1664 }
1665 }
1666
1667 snaplen = skb->len;
1668
1669 res = run_filter(skb, sk, snaplen);
1670 if (!res)
1671 goto drop_n_restore;
1672 if (snaplen > res)
1673 snaplen = res;
1674
1675 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1676 goto drop_n_acct;
1677
1678 if (skb_shared(skb)) {
1679 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1680 if (nskb == NULL)
1681 goto drop_n_acct;
1682
1683 if (skb_head != skb->data) {
1684 skb->data = skb_head;
1685 skb->len = skb_len;
1686 }
1687 consume_skb(skb);
1688 skb = nskb;
1689 }
1690
1691 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1692 sizeof(skb->cb));
1693
1694 sll = &PACKET_SKB_CB(skb)->sa.ll;
1695 sll->sll_family = AF_PACKET;
1696 sll->sll_hatype = dev->type;
1697 sll->sll_protocol = skb->protocol;
1698 sll->sll_pkttype = skb->pkt_type;
1699 if (unlikely(po->origdev))
1700 sll->sll_ifindex = orig_dev->ifindex;
1701 else
1702 sll->sll_ifindex = dev->ifindex;
1703
1704 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1705
1706 PACKET_SKB_CB(skb)->origlen = skb->len;
1707
1708 if (pskb_trim(skb, snaplen))
1709 goto drop_n_acct;
1710
1711 skb_set_owner_r(skb, sk);
1712 skb->dev = NULL;
1713 skb_dst_drop(skb);
1714
1715 /* drop conntrack reference */
1716 nf_reset(skb);
1717
1718 spin_lock(&sk->sk_receive_queue.lock);
1719 po->stats.stats1.tp_packets++;
1720 skb->dropcount = atomic_read(&sk->sk_drops);
1721 __skb_queue_tail(&sk->sk_receive_queue, skb);
1722 spin_unlock(&sk->sk_receive_queue.lock);
1723 sk->sk_data_ready(sk, skb->len);
1724 return 0;
1725
1726 drop_n_acct:
1727 spin_lock(&sk->sk_receive_queue.lock);
1728 po->stats.stats1.tp_drops++;
1729 atomic_inc(&sk->sk_drops);
1730 spin_unlock(&sk->sk_receive_queue.lock);
1731
1732 drop_n_restore:
1733 if (skb_head != skb->data && skb_shared(skb)) {
1734 skb->data = skb_head;
1735 skb->len = skb_len;
1736 }
1737 drop:
1738 consume_skb(skb);
1739 return 0;
1740 }
1741
1742 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1743 struct packet_type *pt, struct net_device *orig_dev)
1744 {
1745 struct sock *sk;
1746 struct packet_sock *po;
1747 struct sockaddr_ll *sll;
1748 union tpacket_uhdr h;
1749 u8 *skb_head = skb->data;
1750 int skb_len = skb->len;
1751 unsigned int snaplen, res;
1752 unsigned long status = TP_STATUS_USER;
1753 unsigned short macoff, netoff, hdrlen;
1754 struct sk_buff *copy_skb = NULL;
1755 struct timespec ts;
1756 __u32 ts_status;
1757
1758 if (skb->pkt_type == PACKET_LOOPBACK)
1759 goto drop;
1760
1761 sk = pt->af_packet_priv;
1762 po = pkt_sk(sk);
1763
1764 if (!net_eq(dev_net(dev), sock_net(sk)))
1765 goto drop;
1766
1767 if (dev->header_ops) {
1768 if (sk->sk_type != SOCK_DGRAM)
1769 skb_push(skb, skb->data - skb_mac_header(skb));
1770 else if (skb->pkt_type == PACKET_OUTGOING) {
1771 /* Special case: outgoing packets have ll header at head */
1772 skb_pull(skb, skb_network_offset(skb));
1773 }
1774 }
1775
1776 if (skb->ip_summed == CHECKSUM_PARTIAL)
1777 status |= TP_STATUS_CSUMNOTREADY;
1778
1779 snaplen = skb->len;
1780
1781 res = run_filter(skb, sk, snaplen);
1782 if (!res)
1783 goto drop_n_restore;
1784 if (snaplen > res)
1785 snaplen = res;
1786
1787 if (sk->sk_type == SOCK_DGRAM) {
1788 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1789 po->tp_reserve;
1790 } else {
1791 unsigned int maclen = skb_network_offset(skb);
1792 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1793 (maclen < 16 ? 16 : maclen)) +
1794 po->tp_reserve;
1795 macoff = netoff - maclen;
1796 }
1797 if (po->tp_version <= TPACKET_V2) {
1798 if (macoff + snaplen > po->rx_ring.frame_size) {
1799 if (po->copy_thresh &&
1800 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1801 if (skb_shared(skb)) {
1802 copy_skb = skb_clone(skb, GFP_ATOMIC);
1803 } else {
1804 copy_skb = skb_get(skb);
1805 skb_head = skb->data;
1806 }
1807 if (copy_skb)
1808 skb_set_owner_r(copy_skb, sk);
1809 }
1810 snaplen = po->rx_ring.frame_size - macoff;
1811 if ((int)snaplen < 0)
1812 snaplen = 0;
1813 }
1814 } else if (unlikely(macoff + snaplen >
1815 GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
1816 u32 nval;
1817
1818 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
1819 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
1820 snaplen, nval, macoff);
1821 snaplen = nval;
1822 if (unlikely((int)snaplen < 0)) {
1823 snaplen = 0;
1824 macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
1825 }
1826 }
1827 spin_lock(&sk->sk_receive_queue.lock);
1828 h.raw = packet_current_rx_frame(po, skb,
1829 TP_STATUS_KERNEL, (macoff+snaplen));
1830 if (!h.raw)
1831 goto ring_is_full;
1832 if (po->tp_version <= TPACKET_V2) {
1833 packet_increment_rx_head(po, &po->rx_ring);
1834 /*
1835 * LOSING will be reported till you read the stats,
1836 * because it's COR - Clear On Read.
1837 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1838 * at packet level.
1839 */
1840 if (po->stats.stats1.tp_drops)
1841 status |= TP_STATUS_LOSING;
1842 }
1843 po->stats.stats1.tp_packets++;
1844 if (copy_skb) {
1845 status |= TP_STATUS_COPY;
1846 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1847 }
1848 spin_unlock(&sk->sk_receive_queue.lock);
1849
1850 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1851
1852 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1853 getnstimeofday(&ts);
1854
1855 status |= ts_status;
1856
1857 switch (po->tp_version) {
1858 case TPACKET_V1:
1859 h.h1->tp_len = skb->len;
1860 h.h1->tp_snaplen = snaplen;
1861 h.h1->tp_mac = macoff;
1862 h.h1->tp_net = netoff;
1863 h.h1->tp_sec = ts.tv_sec;
1864 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1865 hdrlen = sizeof(*h.h1);
1866 break;
1867 case TPACKET_V2:
1868 h.h2->tp_len = skb->len;
1869 h.h2->tp_snaplen = snaplen;
1870 h.h2->tp_mac = macoff;
1871 h.h2->tp_net = netoff;
1872 h.h2->tp_sec = ts.tv_sec;
1873 h.h2->tp_nsec = ts.tv_nsec;
1874 if (vlan_tx_tag_present(skb)) {
1875 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1876 status |= TP_STATUS_VLAN_VALID;
1877 } else {
1878 h.h2->tp_vlan_tci = 0;
1879 }
1880 h.h2->tp_padding = 0;
1881 hdrlen = sizeof(*h.h2);
1882 break;
1883 case TPACKET_V3:
1884 /* tp_nxt_offset,vlan are already populated above.
1885 * So DONT clear those fields here
1886 */
1887 h.h3->tp_status |= status;
1888 h.h3->tp_len = skb->len;
1889 h.h3->tp_snaplen = snaplen;
1890 h.h3->tp_mac = macoff;
1891 h.h3->tp_net = netoff;
1892 h.h3->tp_sec = ts.tv_sec;
1893 h.h3->tp_nsec = ts.tv_nsec;
1894 hdrlen = sizeof(*h.h3);
1895 break;
1896 default:
1897 BUG();
1898 }
1899
1900 sll = h.raw + TPACKET_ALIGN(hdrlen);
1901 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1902 sll->sll_family = AF_PACKET;
1903 sll->sll_hatype = dev->type;
1904 sll->sll_protocol = skb->protocol;
1905 sll->sll_pkttype = skb->pkt_type;
1906 if (unlikely(po->origdev))
1907 sll->sll_ifindex = orig_dev->ifindex;
1908 else
1909 sll->sll_ifindex = dev->ifindex;
1910
1911 smp_mb();
1912 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1913 {
1914 u8 *start, *end;
1915
1916 if (po->tp_version <= TPACKET_V2) {
1917 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1918 + macoff + snaplen);
1919 for (start = h.raw; start < end; start += PAGE_SIZE)
1920 flush_dcache_page(pgv_to_page(start));
1921 }
1922 smp_wmb();
1923 }
1924 #endif
1925 if (po->tp_version <= TPACKET_V2)
1926 __packet_set_status(po, h.raw, status);
1927 else
1928 prb_clear_blk_fill_status(&po->rx_ring);
1929
1930 sk->sk_data_ready(sk, 0);
1931
1932 drop_n_restore:
1933 if (skb_head != skb->data && skb_shared(skb)) {
1934 skb->data = skb_head;
1935 skb->len = skb_len;
1936 }
1937 drop:
1938 kfree_skb(skb);
1939 return 0;
1940
1941 ring_is_full:
1942 po->stats.stats1.tp_drops++;
1943 spin_unlock(&sk->sk_receive_queue.lock);
1944
1945 sk->sk_data_ready(sk, 0);
1946 kfree_skb(copy_skb);
1947 goto drop_n_restore;
1948 }
1949
1950 static void tpacket_destruct_skb(struct sk_buff *skb)
1951 {
1952 struct packet_sock *po = pkt_sk(skb->sk);
1953 void *ph;
1954
1955 if (likely(po->tx_ring.pg_vec)) {
1956 __u32 ts;
1957
1958 ph = skb_shinfo(skb)->destructor_arg;
1959 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1960 atomic_dec(&po->tx_ring.pending);
1961
1962 ts = __packet_set_timestamp(po, ph, skb);
1963 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
1964 }
1965
1966 sock_wfree(skb);
1967 }
1968
1969 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1970 void *frame, struct net_device *dev, int size_max,
1971 __be16 proto, unsigned char *addr, int hlen)
1972 {
1973 union tpacket_uhdr ph;
1974 int to_write, offset, len, tp_len, nr_frags, len_max;
1975 struct socket *sock = po->sk.sk_socket;
1976 struct page *page;
1977 void *data;
1978 int err;
1979
1980 ph.raw = frame;
1981
1982 skb->protocol = proto;
1983 skb->dev = dev;
1984 skb->priority = po->sk.sk_priority;
1985 skb->mark = po->sk.sk_mark;
1986 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
1987 skb_shinfo(skb)->destructor_arg = ph.raw;
1988
1989 switch (po->tp_version) {
1990 case TPACKET_V2:
1991 tp_len = ph.h2->tp_len;
1992 break;
1993 default:
1994 tp_len = ph.h1->tp_len;
1995 break;
1996 }
1997 if (unlikely(tp_len > size_max)) {
1998 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1999 return -EMSGSIZE;
2000 }
2001
2002 skb_reserve(skb, hlen);
2003 skb_reset_network_header(skb);
2004 skb_probe_transport_header(skb, 0);
2005
2006 if (po->tp_tx_has_off) {
2007 int off_min, off_max, off;
2008 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2009 off_max = po->tx_ring.frame_size - tp_len;
2010 if (sock->type == SOCK_DGRAM) {
2011 switch (po->tp_version) {
2012 case TPACKET_V2:
2013 off = ph.h2->tp_net;
2014 break;
2015 default:
2016 off = ph.h1->tp_net;
2017 break;
2018 }
2019 } else {
2020 switch (po->tp_version) {
2021 case TPACKET_V2:
2022 off = ph.h2->tp_mac;
2023 break;
2024 default:
2025 off = ph.h1->tp_mac;
2026 break;
2027 }
2028 }
2029 if (unlikely((off < off_min) || (off_max < off)))
2030 return -EINVAL;
2031 data = ph.raw + off;
2032 } else {
2033 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2034 }
2035 to_write = tp_len;
2036
2037 if (sock->type == SOCK_DGRAM) {
2038 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2039 NULL, tp_len);
2040 if (unlikely(err < 0))
2041 return -EINVAL;
2042 } else if (dev->hard_header_len) {
2043 /* net device doesn't like empty head */
2044 if (unlikely(tp_len <= dev->hard_header_len)) {
2045 pr_err("packet size is too short (%d < %d)\n",
2046 tp_len, dev->hard_header_len);
2047 return -EINVAL;
2048 }
2049
2050 skb_push(skb, dev->hard_header_len);
2051 err = skb_store_bits(skb, 0, data,
2052 dev->hard_header_len);
2053 if (unlikely(err))
2054 return err;
2055
2056 data += dev->hard_header_len;
2057 to_write -= dev->hard_header_len;
2058 }
2059
2060 offset = offset_in_page(data);
2061 len_max = PAGE_SIZE - offset;
2062 len = ((to_write > len_max) ? len_max : to_write);
2063
2064 skb->data_len = to_write;
2065 skb->len += to_write;
2066 skb->truesize += to_write;
2067 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2068
2069 while (likely(to_write)) {
2070 nr_frags = skb_shinfo(skb)->nr_frags;
2071
2072 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2073 pr_err("Packet exceed the number of skb frags(%lu)\n",
2074 MAX_SKB_FRAGS);
2075 return -EFAULT;
2076 }
2077
2078 page = pgv_to_page(data);
2079 data += len;
2080 flush_dcache_page(page);
2081 get_page(page);
2082 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2083 to_write -= len;
2084 offset = 0;
2085 len_max = PAGE_SIZE;
2086 len = ((to_write > len_max) ? len_max : to_write);
2087 }
2088
2089 return tp_len;
2090 }
2091
2092 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2093 {
2094 struct sk_buff *skb;
2095 struct net_device *dev;
2096 __be16 proto;
2097 int err, reserve = 0;
2098 void *ph;
2099 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2100 int tp_len, size_max;
2101 unsigned char *addr;
2102 int len_sum = 0;
2103 int status = TP_STATUS_AVAILABLE;
2104 int hlen, tlen;
2105
2106 mutex_lock(&po->pg_vec_lock);
2107
2108 if (likely(saddr == NULL)) {
2109 dev = packet_cached_dev_get(po);
2110 proto = po->num;
2111 addr = NULL;
2112 } else {
2113 err = -EINVAL;
2114 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2115 goto out;
2116 if (msg->msg_namelen < (saddr->sll_halen
2117 + offsetof(struct sockaddr_ll,
2118 sll_addr)))
2119 goto out;
2120 proto = saddr->sll_protocol;
2121 addr = saddr->sll_addr;
2122 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2123 }
2124
2125 err = -ENXIO;
2126 if (unlikely(dev == NULL))
2127 goto out;
2128 err = -ENETDOWN;
2129 if (unlikely(!(dev->flags & IFF_UP)))
2130 goto out_put;
2131
2132 reserve = dev->hard_header_len;
2133
2134 size_max = po->tx_ring.frame_size
2135 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2136
2137 if (size_max > dev->mtu + reserve)
2138 size_max = dev->mtu + reserve;
2139
2140 do {
2141 ph = packet_current_frame(po, &po->tx_ring,
2142 TP_STATUS_SEND_REQUEST);
2143
2144 if (unlikely(ph == NULL)) {
2145 schedule();
2146 continue;
2147 }
2148
2149 status = TP_STATUS_SEND_REQUEST;
2150 hlen = LL_RESERVED_SPACE(dev);
2151 tlen = dev->needed_tailroom;
2152 skb = sock_alloc_send_skb(&po->sk,
2153 hlen + tlen + sizeof(struct sockaddr_ll),
2154 0, &err);
2155
2156 if (unlikely(skb == NULL))
2157 goto out_status;
2158
2159 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2160 addr, hlen);
2161
2162 if (unlikely(tp_len < 0)) {
2163 if (po->tp_loss) {
2164 __packet_set_status(po, ph,
2165 TP_STATUS_AVAILABLE);
2166 packet_increment_head(&po->tx_ring);
2167 kfree_skb(skb);
2168 continue;
2169 } else {
2170 status = TP_STATUS_WRONG_FORMAT;
2171 err = tp_len;
2172 goto out_status;
2173 }
2174 }
2175
2176 skb->destructor = tpacket_destruct_skb;
2177 __packet_set_status(po, ph, TP_STATUS_SENDING);
2178 atomic_inc(&po->tx_ring.pending);
2179
2180 status = TP_STATUS_SEND_REQUEST;
2181 err = dev_queue_xmit(skb);
2182 if (unlikely(err > 0)) {
2183 err = net_xmit_errno(err);
2184 if (err && __packet_get_status(po, ph) ==
2185 TP_STATUS_AVAILABLE) {
2186 /* skb was destructed already */
2187 skb = NULL;
2188 goto out_status;
2189 }
2190 /*
2191 * skb was dropped but not destructed yet;
2192 * let's treat it like congestion or err < 0
2193 */
2194 err = 0;
2195 }
2196 packet_increment_head(&po->tx_ring);
2197 len_sum += tp_len;
2198 } while (likely((ph != NULL) ||
2199 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2200 (atomic_read(&po->tx_ring.pending))))
2201 );
2202
2203 err = len_sum;
2204 goto out_put;
2205
2206 out_status:
2207 __packet_set_status(po, ph, status);
2208 kfree_skb(skb);
2209 out_put:
2210 dev_put(dev);
2211 out:
2212 mutex_unlock(&po->pg_vec_lock);
2213 return err;
2214 }
2215
2216 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2217 size_t reserve, size_t len,
2218 size_t linear, int noblock,
2219 int *err)
2220 {
2221 struct sk_buff *skb;
2222
2223 /* Under a page? Don't bother with paged skb. */
2224 if (prepad + len < PAGE_SIZE || !linear)
2225 linear = len;
2226
2227 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2228 err);
2229 if (!skb)
2230 return NULL;
2231
2232 skb_reserve(skb, reserve);
2233 skb_put(skb, linear);
2234 skb->data_len = len - linear;
2235 skb->len += len - linear;
2236
2237 return skb;
2238 }
2239
2240 static int packet_snd(struct socket *sock,
2241 struct msghdr *msg, size_t len)
2242 {
2243 struct sock *sk = sock->sk;
2244 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2245 struct sk_buff *skb;
2246 struct net_device *dev;
2247 __be16 proto;
2248 unsigned char *addr;
2249 int err, reserve = 0;
2250 struct virtio_net_hdr vnet_hdr = { 0 };
2251 int offset = 0;
2252 int vnet_hdr_len;
2253 struct packet_sock *po = pkt_sk(sk);
2254 unsigned short gso_type = 0;
2255 int hlen, tlen, linear;
2256 int extra_len = 0;
2257
2258 /*
2259 * Get and verify the address.
2260 */
2261
2262 if (likely(saddr == NULL)) {
2263 dev = packet_cached_dev_get(po);
2264 proto = po->num;
2265 addr = NULL;
2266 } else {
2267 err = -EINVAL;
2268 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2269 goto out;
2270 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2271 goto out;
2272 proto = saddr->sll_protocol;
2273 addr = saddr->sll_addr;
2274 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2275 }
2276
2277 err = -ENXIO;
2278 if (unlikely(dev == NULL))
2279 goto out_unlock;
2280 err = -ENETDOWN;
2281 if (unlikely(!(dev->flags & IFF_UP)))
2282 goto out_unlock;
2283
2284 if (sock->type == SOCK_RAW)
2285 reserve = dev->hard_header_len;
2286 if (po->has_vnet_hdr) {
2287 vnet_hdr_len = sizeof(vnet_hdr);
2288
2289 err = -EINVAL;
2290 if (len < vnet_hdr_len)
2291 goto out_unlock;
2292
2293 len -= vnet_hdr_len;
2294
2295 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2296 vnet_hdr_len);
2297 if (err < 0)
2298 goto out_unlock;
2299
2300 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2301 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2302 vnet_hdr.hdr_len))
2303 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2304 vnet_hdr.csum_offset + 2;
2305
2306 err = -EINVAL;
2307 if (vnet_hdr.hdr_len > len)
2308 goto out_unlock;
2309
2310 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2311 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2312 case VIRTIO_NET_HDR_GSO_TCPV4:
2313 gso_type = SKB_GSO_TCPV4;
2314 break;
2315 case VIRTIO_NET_HDR_GSO_TCPV6:
2316 gso_type = SKB_GSO_TCPV6;
2317 break;
2318 case VIRTIO_NET_HDR_GSO_UDP:
2319 gso_type = SKB_GSO_UDP;
2320 break;
2321 default:
2322 goto out_unlock;
2323 }
2324
2325 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2326 gso_type |= SKB_GSO_TCP_ECN;
2327
2328 if (vnet_hdr.gso_size == 0)
2329 goto out_unlock;
2330
2331 }
2332 }
2333
2334 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2335 if (!netif_supports_nofcs(dev)) {
2336 err = -EPROTONOSUPPORT;
2337 goto out_unlock;
2338 }
2339 extra_len = 4; /* We're doing our own CRC */
2340 }
2341
2342 err = -EMSGSIZE;
2343 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2344 goto out_unlock;
2345
2346 err = -ENOBUFS;
2347 hlen = LL_RESERVED_SPACE(dev);
2348 tlen = dev->needed_tailroom;
2349 linear = vnet_hdr.hdr_len;
2350 linear = max(linear, min_t(int, len, dev->hard_header_len));
2351 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2352 msg->msg_flags & MSG_DONTWAIT, &err);
2353 if (skb == NULL)
2354 goto out_unlock;
2355
2356 skb_set_network_header(skb, reserve);
2357
2358 err = -EINVAL;
2359 if (sock->type == SOCK_DGRAM &&
2360 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2361 goto out_free;
2362
2363 /* Returns -EFAULT on error */
2364 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2365 if (err)
2366 goto out_free;
2367
2368 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2369
2370 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2371 /* Earlier code assumed this would be a VLAN pkt,
2372 * double-check this now that we have the actual
2373 * packet in hand.
2374 */
2375 struct ethhdr *ehdr;
2376 skb_reset_mac_header(skb);
2377 ehdr = eth_hdr(skb);
2378 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2379 err = -EMSGSIZE;
2380 goto out_free;
2381 }
2382 }
2383
2384 skb->protocol = proto;
2385 skb->dev = dev;
2386 skb->priority = sk->sk_priority;
2387 skb->mark = sk->sk_mark;
2388
2389 if (po->has_vnet_hdr) {
2390 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2391 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2392 vnet_hdr.csum_offset)) {
2393 err = -EINVAL;
2394 goto out_free;
2395 }
2396 }
2397
2398 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2399 skb_shinfo(skb)->gso_type = gso_type;
2400
2401 /* Header must be checked, and gso_segs computed. */
2402 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2403 skb_shinfo(skb)->gso_segs = 0;
2404
2405 len += vnet_hdr_len;
2406 }
2407
2408 skb_probe_transport_header(skb, reserve);
2409
2410 if (unlikely(extra_len == 4))
2411 skb->no_fcs = 1;
2412
2413 /*
2414 * Now send it
2415 */
2416
2417 err = dev_queue_xmit(skb);
2418 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2419 goto out_unlock;
2420
2421 dev_put(dev);
2422
2423 return len;
2424
2425 out_free:
2426 kfree_skb(skb);
2427 out_unlock:
2428 if (dev)
2429 dev_put(dev);
2430 out:
2431 return err;
2432 }
2433
2434 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2435 struct msghdr *msg, size_t len)
2436 {
2437 struct sock *sk = sock->sk;
2438 struct packet_sock *po = pkt_sk(sk);
2439 if (po->tx_ring.pg_vec)
2440 return tpacket_snd(po, msg);
2441 else
2442 return packet_snd(sock, msg, len);
2443 }
2444
2445 /*
2446 * Close a PACKET socket. This is fairly simple. We immediately go
2447 * to 'closed' state and remove our protocol entry in the device list.
2448 */
2449
2450 static int packet_release(struct socket *sock)
2451 {
2452 struct sock *sk = sock->sk;
2453 struct packet_sock *po;
2454 struct packet_fanout *f;
2455 struct net *net;
2456 union tpacket_req_u req_u;
2457
2458 if (!sk)
2459 return 0;
2460
2461 net = sock_net(sk);
2462 po = pkt_sk(sk);
2463
2464 mutex_lock(&net->packet.sklist_lock);
2465 sk_del_node_init_rcu(sk);
2466 mutex_unlock(&net->packet.sklist_lock);
2467
2468 preempt_disable();
2469 sock_prot_inuse_add(net, sk->sk_prot, -1);
2470 preempt_enable();
2471
2472 spin_lock(&po->bind_lock);
2473 unregister_prot_hook(sk, false);
2474 packet_cached_dev_reset(po);
2475
2476 if (po->prot_hook.dev) {
2477 dev_put(po->prot_hook.dev);
2478 po->prot_hook.dev = NULL;
2479 }
2480 spin_unlock(&po->bind_lock);
2481
2482 packet_flush_mclist(sk);
2483
2484 if (po->rx_ring.pg_vec) {
2485 memset(&req_u, 0, sizeof(req_u));
2486 packet_set_ring(sk, &req_u, 1, 0);
2487 }
2488
2489 if (po->tx_ring.pg_vec) {
2490 memset(&req_u, 0, sizeof(req_u));
2491 packet_set_ring(sk, &req_u, 1, 1);
2492 }
2493
2494 f = fanout_release(sk);
2495
2496 synchronize_net();
2497
2498 if (f) {
2499 kfree(f);
2500 }
2501 /*
2502 * Now the socket is dead. No more input will appear.
2503 */
2504 sock_orphan(sk);
2505 sock->sk = NULL;
2506
2507 /* Purge queues */
2508
2509 skb_queue_purge(&sk->sk_receive_queue);
2510 sk_refcnt_debug_release(sk);
2511
2512 sock_put(sk);
2513 return 0;
2514 }
2515
2516 /*
2517 * Attach a packet hook.
2518 */
2519
2520 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2521 {
2522 struct packet_sock *po = pkt_sk(sk);
2523 int ret = 0;
2524
2525 lock_sock(sk);
2526
2527 spin_lock(&po->bind_lock);
2528
2529 if (po->fanout) {
2530 if (dev)
2531 dev_put(dev);
2532
2533 ret = -EINVAL;
2534 goto out_unlock;
2535 }
2536
2537 unregister_prot_hook(sk, true);
2538
2539 po->num = protocol;
2540 po->prot_hook.type = protocol;
2541 if (po->prot_hook.dev)
2542 dev_put(po->prot_hook.dev);
2543
2544 po->prot_hook.dev = dev;
2545 po->ifindex = dev ? dev->ifindex : 0;
2546
2547 packet_cached_dev_assign(po, dev);
2548
2549 if (protocol == 0)
2550 goto out_unlock;
2551
2552 if (!dev || (dev->flags & IFF_UP)) {
2553 register_prot_hook(sk);
2554 } else {
2555 sk->sk_err = ENETDOWN;
2556 if (!sock_flag(sk, SOCK_DEAD))
2557 sk->sk_error_report(sk);
2558 }
2559
2560 out_unlock:
2561 spin_unlock(&po->bind_lock);
2562 release_sock(sk);
2563 return ret;
2564 }
2565
2566 /*
2567 * Bind a packet socket to a device
2568 */
2569
2570 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2571 int addr_len)
2572 {
2573 struct sock *sk = sock->sk;
2574 char name[sizeof(uaddr->sa_data) + 1];
2575 struct net_device *dev;
2576 int err = -ENODEV;
2577
2578 /*
2579 * Check legality
2580 */
2581
2582 if (addr_len != sizeof(struct sockaddr))
2583 return -EINVAL;
2584 /* uaddr->sa_data comes from the userspace, it's not guaranteed to be
2585 * zero-terminated.
2586 */
2587 memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
2588 name[sizeof(uaddr->sa_data)] = 0;
2589
2590 dev = dev_get_by_name(sock_net(sk), name);
2591 if (dev)
2592 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2593 return err;
2594 }
2595
2596 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2597 {
2598 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2599 struct sock *sk = sock->sk;
2600 struct net_device *dev = NULL;
2601 int err;
2602
2603
2604 /*
2605 * Check legality
2606 */
2607
2608 if (addr_len < sizeof(struct sockaddr_ll))
2609 return -EINVAL;
2610 if (sll->sll_family != AF_PACKET)
2611 return -EINVAL;
2612
2613 if (sll->sll_ifindex) {
2614 err = -ENODEV;
2615 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2616 if (dev == NULL)
2617 goto out;
2618 }
2619 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2620
2621 out:
2622 return err;
2623 }
2624
2625 static struct proto packet_proto = {
2626 .name = "PACKET",
2627 .owner = THIS_MODULE,
2628 .obj_size = sizeof(struct packet_sock),
2629 };
2630
2631 /*
2632 * Create a packet of type SOCK_PACKET.
2633 */
2634
2635 static int packet_create(struct net *net, struct socket *sock, int protocol,
2636 int kern)
2637 {
2638 struct sock *sk;
2639 struct packet_sock *po;
2640 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2641 int err;
2642
2643 if (!ns_capable(net->user_ns, CAP_NET_RAW))
2644 return -EPERM;
2645 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2646 sock->type != SOCK_PACKET)
2647 return -ESOCKTNOSUPPORT;
2648
2649 sock->state = SS_UNCONNECTED;
2650
2651 err = -ENOBUFS;
2652 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2653 if (sk == NULL)
2654 goto out;
2655
2656 sock->ops = &packet_ops;
2657 if (sock->type == SOCK_PACKET)
2658 sock->ops = &packet_ops_spkt;
2659
2660 sock_init_data(sock, sk);
2661
2662 po = pkt_sk(sk);
2663 sk->sk_family = PF_PACKET;
2664 po->num = proto;
2665
2666 packet_cached_dev_reset(po);
2667
2668 sk->sk_destruct = packet_sock_destruct;
2669 sk_refcnt_debug_inc(sk);
2670
2671 /*
2672 * Attach a protocol block
2673 */
2674
2675 spin_lock_init(&po->bind_lock);
2676 mutex_init(&po->pg_vec_lock);
2677 po->prot_hook.func = packet_rcv;
2678
2679 if (sock->type == SOCK_PACKET)
2680 po->prot_hook.func = packet_rcv_spkt;
2681
2682 po->prot_hook.af_packet_priv = sk;
2683
2684 if (proto) {
2685 po->prot_hook.type = proto;
2686 register_prot_hook(sk);
2687 }
2688
2689 mutex_lock(&net->packet.sklist_lock);
2690 sk_add_node_rcu(sk, &net->packet.sklist);
2691 mutex_unlock(&net->packet.sklist_lock);
2692
2693 preempt_disable();
2694 sock_prot_inuse_add(net, &packet_proto, 1);
2695 preempt_enable();
2696
2697 return 0;
2698 out:
2699 return err;
2700 }
2701
2702 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2703 {
2704 struct sock_exterr_skb *serr;
2705 struct sk_buff *skb, *skb2;
2706 int copied, err;
2707
2708 err = -EAGAIN;
2709 skb = skb_dequeue(&sk->sk_error_queue);
2710 if (skb == NULL)
2711 goto out;
2712
2713 copied = skb->len;
2714 if (copied > len) {
2715 msg->msg_flags |= MSG_TRUNC;
2716 copied = len;
2717 }
2718 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2719 if (err)
2720 goto out_free_skb;
2721
2722 sock_recv_timestamp(msg, sk, skb);
2723
2724 serr = SKB_EXT_ERR(skb);
2725 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2726 sizeof(serr->ee), &serr->ee);
2727
2728 msg->msg_flags |= MSG_ERRQUEUE;
2729 err = copied;
2730
2731 /* Reset and regenerate socket error */
2732 spin_lock_bh(&sk->sk_error_queue.lock);
2733 sk->sk_err = 0;
2734 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2735 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2736 spin_unlock_bh(&sk->sk_error_queue.lock);
2737 sk->sk_error_report(sk);
2738 } else
2739 spin_unlock_bh(&sk->sk_error_queue.lock);
2740
2741 out_free_skb:
2742 kfree_skb(skb);
2743 out:
2744 return err;
2745 }
2746
2747 /*
2748 * Pull a packet from our receive queue and hand it to the user.
2749 * If necessary we block.
2750 */
2751
2752 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2753 struct msghdr *msg, size_t len, int flags)
2754 {
2755 struct sock *sk = sock->sk;
2756 struct sk_buff *skb;
2757 int copied, err;
2758 int vnet_hdr_len = 0;
2759
2760 err = -EINVAL;
2761 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2762 goto out;
2763
2764 #if 0
2765 /* What error should we return now? EUNATTACH? */
2766 if (pkt_sk(sk)->ifindex < 0)
2767 return -ENODEV;
2768 #endif
2769
2770 if (flags & MSG_ERRQUEUE) {
2771 err = packet_recv_error(sk, msg, len);
2772 goto out;
2773 }
2774
2775 /*
2776 * Call the generic datagram receiver. This handles all sorts
2777 * of horrible races and re-entrancy so we can forget about it
2778 * in the protocol layers.
2779 *
2780 * Now it will return ENETDOWN, if device have just gone down,
2781 * but then it will block.
2782 */
2783
2784 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2785
2786 /*
2787 * An error occurred so return it. Because skb_recv_datagram()
2788 * handles the blocking we don't see and worry about blocking
2789 * retries.
2790 */
2791
2792 if (skb == NULL)
2793 goto out;
2794
2795 if (pkt_sk(sk)->has_vnet_hdr) {
2796 struct virtio_net_hdr vnet_hdr = { 0 };
2797
2798 err = -EINVAL;
2799 vnet_hdr_len = sizeof(vnet_hdr);
2800 if (len < vnet_hdr_len)
2801 goto out_free;
2802
2803 len -= vnet_hdr_len;
2804
2805 if (skb_is_gso(skb)) {
2806 struct skb_shared_info *sinfo = skb_shinfo(skb);
2807
2808 /* This is a hint as to how much should be linear. */
2809 vnet_hdr.hdr_len = skb_headlen(skb);
2810 vnet_hdr.gso_size = sinfo->gso_size;
2811 if (sinfo->gso_type & SKB_GSO_TCPV4)
2812 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2813 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2814 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2815 else if (sinfo->gso_type & SKB_GSO_UDP)
2816 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2817 else if (sinfo->gso_type & SKB_GSO_FCOE)
2818 goto out_free;
2819 else
2820 BUG();
2821 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2822 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2823 } else
2824 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2825
2826 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2827 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2828 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2829 vnet_hdr.csum_offset = skb->csum_offset;
2830 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2831 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2832 } /* else everything is zero */
2833
2834 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2835 vnet_hdr_len);
2836 if (err < 0)
2837 goto out_free;
2838 }
2839
2840 /* You lose any data beyond the buffer you gave. If it worries
2841 * a user program they can ask the device for its MTU
2842 * anyway.
2843 */
2844 copied = skb->len;
2845 if (copied > len) {
2846 copied = len;
2847 msg->msg_flags |= MSG_TRUNC;
2848 }
2849
2850 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2851 if (err)
2852 goto out_free;
2853
2854 sock_recv_ts_and_drops(msg, sk, skb);
2855
2856 if (msg->msg_name) {
2857 /* If the address length field is there to be filled
2858 * in, we fill it in now.
2859 */
2860 if (sock->type == SOCK_PACKET) {
2861 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2862 } else {
2863 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
2864 msg->msg_namelen = sll->sll_halen +
2865 offsetof(struct sockaddr_ll, sll_addr);
2866 }
2867 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2868 msg->msg_namelen);
2869 }
2870
2871 if (pkt_sk(sk)->auxdata) {
2872 struct tpacket_auxdata aux;
2873
2874 aux.tp_status = TP_STATUS_USER;
2875 if (skb->ip_summed == CHECKSUM_PARTIAL)
2876 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2877 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2878 aux.tp_snaplen = skb->len;
2879 aux.tp_mac = 0;
2880 aux.tp_net = skb_network_offset(skb);
2881 if (vlan_tx_tag_present(skb)) {
2882 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2883 aux.tp_status |= TP_STATUS_VLAN_VALID;
2884 } else {
2885 aux.tp_vlan_tci = 0;
2886 }
2887 aux.tp_padding = 0;
2888 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2889 }
2890
2891 /*
2892 * Free or return the buffer as appropriate. Again this
2893 * hides all the races and re-entrancy issues from us.
2894 */
2895 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2896
2897 out_free:
2898 skb_free_datagram(sk, skb);
2899 out:
2900 return err;
2901 }
2902
2903 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2904 int *uaddr_len, int peer)
2905 {
2906 struct net_device *dev;
2907 struct sock *sk = sock->sk;
2908
2909 if (peer)
2910 return -EOPNOTSUPP;
2911
2912 uaddr->sa_family = AF_PACKET;
2913 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
2914 rcu_read_lock();
2915 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2916 if (dev)
2917 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
2918 rcu_read_unlock();
2919 *uaddr_len = sizeof(*uaddr);
2920
2921 return 0;
2922 }
2923
2924 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2925 int *uaddr_len, int peer)
2926 {
2927 struct net_device *dev;
2928 struct sock *sk = sock->sk;
2929 struct packet_sock *po = pkt_sk(sk);
2930 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2931
2932 if (peer)
2933 return -EOPNOTSUPP;
2934
2935 sll->sll_family = AF_PACKET;
2936 sll->sll_ifindex = po->ifindex;
2937 sll->sll_protocol = po->num;
2938 sll->sll_pkttype = 0;
2939 rcu_read_lock();
2940 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2941 if (dev) {
2942 sll->sll_hatype = dev->type;
2943 sll->sll_halen = dev->addr_len;
2944 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2945 } else {
2946 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2947 sll->sll_halen = 0;
2948 }
2949 rcu_read_unlock();
2950 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2951
2952 return 0;
2953 }
2954
2955 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2956 int what)
2957 {
2958 switch (i->type) {
2959 case PACKET_MR_MULTICAST:
2960 if (i->alen != dev->addr_len)
2961 return -EINVAL;
2962 if (what > 0)
2963 return dev_mc_add(dev, i->addr);
2964 else
2965 return dev_mc_del(dev, i->addr);
2966 break;
2967 case PACKET_MR_PROMISC:
2968 return dev_set_promiscuity(dev, what);
2969 break;
2970 case PACKET_MR_ALLMULTI:
2971 return dev_set_allmulti(dev, what);
2972 break;
2973 case PACKET_MR_UNICAST:
2974 if (i->alen != dev->addr_len)
2975 return -EINVAL;
2976 if (what > 0)
2977 return dev_uc_add(dev, i->addr);
2978 else
2979 return dev_uc_del(dev, i->addr);
2980 break;
2981 default:
2982 break;
2983 }
2984 return 0;
2985 }
2986
2987 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2988 {
2989 for ( ; i; i = i->next) {
2990 if (i->ifindex == dev->ifindex)
2991 packet_dev_mc(dev, i, what);
2992 }
2993 }
2994
2995 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2996 {
2997 struct packet_sock *po = pkt_sk(sk);
2998 struct packet_mclist *ml, *i;
2999 struct net_device *dev;
3000 int err;
3001
3002 rtnl_lock();
3003
3004 err = -ENODEV;
3005 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3006 if (!dev)
3007 goto done;
3008
3009 err = -EINVAL;
3010 if (mreq->mr_alen > dev->addr_len)
3011 goto done;
3012
3013 err = -ENOBUFS;
3014 i = kmalloc(sizeof(*i), GFP_KERNEL);
3015 if (i == NULL)
3016 goto done;
3017
3018 err = 0;
3019 for (ml = po->mclist; ml; ml = ml->next) {
3020 if (ml->ifindex == mreq->mr_ifindex &&
3021 ml->type == mreq->mr_type &&
3022 ml->alen == mreq->mr_alen &&
3023 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3024 ml->count++;
3025 /* Free the new element ... */
3026 kfree(i);
3027 goto done;
3028 }
3029 }
3030
3031 i->type = mreq->mr_type;
3032 i->ifindex = mreq->mr_ifindex;
3033 i->alen = mreq->mr_alen;
3034 memcpy(i->addr, mreq->mr_address, i->alen);
3035 memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3036 i->count = 1;
3037 i->next = po->mclist;
3038 po->mclist = i;
3039 err = packet_dev_mc(dev, i, 1);
3040 if (err) {
3041 po->mclist = i->next;
3042 kfree(i);
3043 }
3044
3045 done:
3046 rtnl_unlock();
3047 return err;
3048 }
3049
3050 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3051 {
3052 struct packet_mclist *ml, **mlp;
3053
3054 rtnl_lock();
3055
3056 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3057 if (ml->ifindex == mreq->mr_ifindex &&
3058 ml->type == mreq->mr_type &&
3059 ml->alen == mreq->mr_alen &&
3060 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3061 if (--ml->count == 0) {
3062 struct net_device *dev;
3063 *mlp = ml->next;
3064 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3065 if (dev)
3066 packet_dev_mc(dev, ml, -1);
3067 kfree(ml);
3068 }
3069 rtnl_unlock();
3070 return 0;
3071 }
3072 }
3073 rtnl_unlock();
3074 return -EADDRNOTAVAIL;
3075 }
3076
3077 static void packet_flush_mclist(struct sock *sk)
3078 {
3079 struct packet_sock *po = pkt_sk(sk);
3080 struct packet_mclist *ml;
3081
3082 if (!po->mclist)
3083 return;
3084
3085 rtnl_lock();
3086 while ((ml = po->mclist) != NULL) {
3087 struct net_device *dev;
3088
3089 po->mclist = ml->next;
3090 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3091 if (dev != NULL)
3092 packet_dev_mc(dev, ml, -1);
3093 kfree(ml);
3094 }
3095 rtnl_unlock();
3096 }
3097
3098 static int
3099 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3100 {
3101 struct sock *sk = sock->sk;
3102 struct packet_sock *po = pkt_sk(sk);
3103 int ret;
3104
3105 if (level != SOL_PACKET)
3106 return -ENOPROTOOPT;
3107
3108 switch (optname) {
3109 case PACKET_ADD_MEMBERSHIP:
3110 case PACKET_DROP_MEMBERSHIP:
3111 {
3112 struct packet_mreq_max mreq;
3113 int len = optlen;
3114 memset(&mreq, 0, sizeof(mreq));
3115 if (len < sizeof(struct packet_mreq))
3116 return -EINVAL;
3117 if (len > sizeof(mreq))
3118 len = sizeof(mreq);
3119 if (copy_from_user(&mreq, optval, len))
3120 return -EFAULT;
3121 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3122 return -EINVAL;
3123 if (optname == PACKET_ADD_MEMBERSHIP)
3124 ret = packet_mc_add(sk, &mreq);
3125 else
3126 ret = packet_mc_drop(sk, &mreq);
3127 return ret;
3128 }
3129
3130 case PACKET_RX_RING:
3131 case PACKET_TX_RING:
3132 {
3133 union tpacket_req_u req_u;
3134 int len;
3135
3136 switch (po->tp_version) {
3137 case TPACKET_V1:
3138 case TPACKET_V2:
3139 len = sizeof(req_u.req);
3140 break;
3141 case TPACKET_V3:
3142 default:
3143 len = sizeof(req_u.req3);
3144 break;
3145 }
3146 if (optlen < len)
3147 return -EINVAL;
3148 if (pkt_sk(sk)->has_vnet_hdr)
3149 return -EINVAL;
3150 if (copy_from_user(&req_u.req, optval, len))
3151 return -EFAULT;
3152 return packet_set_ring(sk, &req_u, 0,
3153 optname == PACKET_TX_RING);
3154 }
3155 case PACKET_COPY_THRESH:
3156 {
3157 int val;
3158
3159 if (optlen != sizeof(val))
3160 return -EINVAL;
3161 if (copy_from_user(&val, optval, sizeof(val)))
3162 return -EFAULT;
3163
3164 pkt_sk(sk)->copy_thresh = val;
3165 return 0;
3166 }
3167 case PACKET_VERSION:
3168 {
3169 int val;
3170
3171 if (optlen != sizeof(val))
3172 return -EINVAL;
3173 if (copy_from_user(&val, optval, sizeof(val)))
3174 return -EFAULT;
3175 switch (val) {
3176 case TPACKET_V1:
3177 case TPACKET_V2:
3178 case TPACKET_V3:
3179 break;
3180 default:
3181 return -EINVAL;
3182 }
3183 lock_sock(sk);
3184 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3185 ret = -EBUSY;
3186 } else {
3187 po->tp_version = val;
3188 ret = 0;
3189 }
3190 release_sock(sk);
3191 return ret;
3192 }
3193 case PACKET_RESERVE:
3194 {
3195 unsigned int val;
3196
3197 if (optlen != sizeof(val))
3198 return -EINVAL;
3199 if (copy_from_user(&val, optval, sizeof(val)))
3200 return -EFAULT;
3201 if (val > INT_MAX)
3202 return -EINVAL;
3203 lock_sock(sk);
3204 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3205 ret = -EBUSY;
3206 } else {
3207 po->tp_reserve = val;
3208 ret = 0;
3209 }
3210 release_sock(sk);
3211 return ret;
3212 }
3213 case PACKET_LOSS:
3214 {
3215 unsigned int val;
3216
3217 if (optlen != sizeof(val))
3218 return -EINVAL;
3219 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3220 return -EBUSY;
3221 if (copy_from_user(&val, optval, sizeof(val)))
3222 return -EFAULT;
3223 po->tp_loss = !!val;
3224 return 0;
3225 }
3226 case PACKET_AUXDATA:
3227 {
3228 int val;
3229
3230 if (optlen < sizeof(val))
3231 return -EINVAL;
3232 if (copy_from_user(&val, optval, sizeof(val)))
3233 return -EFAULT;
3234
3235 po->auxdata = !!val;
3236 return 0;
3237 }
3238 case PACKET_ORIGDEV:
3239 {
3240 int val;
3241
3242 if (optlen < sizeof(val))
3243 return -EINVAL;
3244 if (copy_from_user(&val, optval, sizeof(val)))
3245 return -EFAULT;
3246
3247 po->origdev = !!val;
3248 return 0;
3249 }
3250 case PACKET_VNET_HDR:
3251 {
3252 int val;
3253
3254 if (sock->type != SOCK_RAW)
3255 return -EINVAL;
3256 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3257 return -EBUSY;
3258 if (optlen < sizeof(val))
3259 return -EINVAL;
3260 if (copy_from_user(&val, optval, sizeof(val)))
3261 return -EFAULT;
3262
3263 po->has_vnet_hdr = !!val;
3264 return 0;
3265 }
3266 case PACKET_TIMESTAMP:
3267 {
3268 int val;
3269
3270 if (optlen != sizeof(val))
3271 return -EINVAL;
3272 if (copy_from_user(&val, optval, sizeof(val)))
3273 return -EFAULT;
3274
3275 po->tp_tstamp = val;
3276 return 0;
3277 }
3278 case PACKET_FANOUT:
3279 {
3280 int val;
3281
3282 if (optlen != sizeof(val))
3283 return -EINVAL;
3284 if (copy_from_user(&val, optval, sizeof(val)))
3285 return -EFAULT;
3286
3287 return fanout_add(sk, val & 0xffff, val >> 16);
3288 }
3289 case PACKET_TX_HAS_OFF:
3290 {
3291 unsigned int val;
3292
3293 if (optlen != sizeof(val))
3294 return -EINVAL;
3295 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3296 return -EBUSY;
3297 if (copy_from_user(&val, optval, sizeof(val)))
3298 return -EFAULT;
3299 po->tp_tx_has_off = !!val;
3300 return 0;
3301 }
3302 default:
3303 return -ENOPROTOOPT;
3304 }
3305 }
3306
3307 static int packet_getsockopt(struct socket *sock, int level, int optname,
3308 char __user *optval, int __user *optlen)
3309 {
3310 int len;
3311 int val, lv = sizeof(val);
3312 struct sock *sk = sock->sk;
3313 struct packet_sock *po = pkt_sk(sk);
3314 void *data = &val;
3315 union tpacket_stats_u st;
3316
3317 if (level != SOL_PACKET)
3318 return -ENOPROTOOPT;
3319
3320 if (get_user(len, optlen))
3321 return -EFAULT;
3322
3323 if (len < 0)
3324 return -EINVAL;
3325
3326 switch (optname) {
3327 case PACKET_STATISTICS:
3328 spin_lock_bh(&sk->sk_receive_queue.lock);
3329 memcpy(&st, &po->stats, sizeof(st));
3330 memset(&po->stats, 0, sizeof(po->stats));
3331 spin_unlock_bh(&sk->sk_receive_queue.lock);
3332
3333 if (po->tp_version == TPACKET_V3) {
3334 lv = sizeof(struct tpacket_stats_v3);
3335 st.stats3.tp_packets += st.stats3.tp_drops;
3336 data = &st.stats3;
3337 } else {
3338 lv = sizeof(struct tpacket_stats);
3339 st.stats1.tp_packets += st.stats1.tp_drops;
3340 data = &st.stats1;
3341 }
3342
3343 break;
3344 case PACKET_AUXDATA:
3345 val = po->auxdata;
3346 break;
3347 case PACKET_ORIGDEV:
3348 val = po->origdev;
3349 break;
3350 case PACKET_VNET_HDR:
3351 val = po->has_vnet_hdr;
3352 break;
3353 case PACKET_VERSION:
3354 val = po->tp_version;
3355 break;
3356 case PACKET_HDRLEN:
3357 if (len > sizeof(int))
3358 len = sizeof(int);
3359 if (len < sizeof(int))
3360 return -EINVAL;
3361 if (copy_from_user(&val, optval, len))
3362 return -EFAULT;
3363 switch (val) {
3364 case TPACKET_V1:
3365 val = sizeof(struct tpacket_hdr);
3366 break;
3367 case TPACKET_V2:
3368 val = sizeof(struct tpacket2_hdr);
3369 break;
3370 case TPACKET_V3:
3371 val = sizeof(struct tpacket3_hdr);
3372 break;
3373 default:
3374 return -EINVAL;
3375 }
3376 break;
3377 case PACKET_RESERVE:
3378 val = po->tp_reserve;
3379 break;
3380 case PACKET_LOSS:
3381 val = po->tp_loss;
3382 break;
3383 case PACKET_TIMESTAMP:
3384 val = po->tp_tstamp;
3385 break;
3386 case PACKET_FANOUT:
3387 val = (po->fanout ?
3388 ((u32)po->fanout->id |
3389 ((u32)po->fanout->type << 16) |
3390 ((u32)po->fanout->flags << 24)) :
3391 0);
3392 break;
3393 case PACKET_TX_HAS_OFF:
3394 val = po->tp_tx_has_off;
3395 break;
3396 default:
3397 return -ENOPROTOOPT;
3398 }
3399
3400 if (len > lv)
3401 len = lv;
3402 if (put_user(len, optlen))
3403 return -EFAULT;
3404 if (copy_to_user(optval, data, len))
3405 return -EFAULT;
3406 return 0;
3407 }
3408
3409
3410 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3411 {
3412 struct sock *sk;
3413 struct net_device *dev = data;
3414 struct net *net = dev_net(dev);
3415
3416 rcu_read_lock();
3417 sk_for_each_rcu(sk, &net->packet.sklist) {
3418 struct packet_sock *po = pkt_sk(sk);
3419
3420 switch (msg) {
3421 case NETDEV_UNREGISTER:
3422 if (po->mclist)
3423 packet_dev_mclist(dev, po->mclist, -1);
3424 /* fallthrough */
3425
3426 case NETDEV_DOWN:
3427 if (dev->ifindex == po->ifindex) {
3428 spin_lock(&po->bind_lock);
3429 if (po->running) {
3430 __unregister_prot_hook(sk, false);
3431 sk->sk_err = ENETDOWN;
3432 if (!sock_flag(sk, SOCK_DEAD))
3433 sk->sk_error_report(sk);
3434 }
3435 if (msg == NETDEV_UNREGISTER) {
3436 packet_cached_dev_reset(po);
3437 po->ifindex = -1;
3438 if (po->prot_hook.dev)
3439 dev_put(po->prot_hook.dev);
3440 po->prot_hook.dev = NULL;
3441 }
3442 spin_unlock(&po->bind_lock);
3443 }
3444 break;
3445 case NETDEV_UP:
3446 if (dev->ifindex == po->ifindex) {
3447 spin_lock(&po->bind_lock);
3448 if (po->num)
3449 register_prot_hook(sk);
3450 spin_unlock(&po->bind_lock);
3451 }
3452 break;
3453 }
3454 }
3455 rcu_read_unlock();
3456 return NOTIFY_DONE;
3457 }
3458
3459
3460 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3461 unsigned long arg)
3462 {
3463 struct sock *sk = sock->sk;
3464
3465 switch (cmd) {
3466 case SIOCOUTQ:
3467 {
3468 int amount = sk_wmem_alloc_get(sk);
3469
3470 return put_user(amount, (int __user *)arg);
3471 }
3472 case SIOCINQ:
3473 {
3474 struct sk_buff *skb;
3475 int amount = 0;
3476
3477 spin_lock_bh(&sk->sk_receive_queue.lock);
3478 skb = skb_peek(&sk->sk_receive_queue);
3479 if (skb)
3480 amount = skb->len;
3481 spin_unlock_bh(&sk->sk_receive_queue.lock);
3482 return put_user(amount, (int __user *)arg);
3483 }
3484 case SIOCGSTAMP:
3485 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3486 case SIOCGSTAMPNS:
3487 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3488
3489 #ifdef CONFIG_INET
3490 case SIOCADDRT:
3491 case SIOCDELRT:
3492 case SIOCDARP:
3493 case SIOCGARP:
3494 case SIOCSARP:
3495 case SIOCGIFADDR:
3496 case SIOCSIFADDR:
3497 case SIOCGIFBRDADDR:
3498 case SIOCSIFBRDADDR:
3499 case SIOCGIFNETMASK:
3500 case SIOCSIFNETMASK:
3501 case SIOCGIFDSTADDR:
3502 case SIOCSIFDSTADDR:
3503 case SIOCSIFFLAGS:
3504 return inet_dgram_ops.ioctl(sock, cmd, arg);
3505 #endif
3506
3507 default:
3508 return -ENOIOCTLCMD;
3509 }
3510 return 0;
3511 }
3512
3513 static unsigned int packet_poll(struct file *file, struct socket *sock,
3514 poll_table *wait)
3515 {
3516 struct sock *sk = sock->sk;
3517 struct packet_sock *po = pkt_sk(sk);
3518 unsigned int mask = datagram_poll(file, sock, wait);
3519
3520 spin_lock_bh(&sk->sk_receive_queue.lock);
3521 if (po->rx_ring.pg_vec) {
3522 if (!packet_previous_rx_frame(po, &po->rx_ring,
3523 TP_STATUS_KERNEL))
3524 mask |= POLLIN | POLLRDNORM;
3525 }
3526 spin_unlock_bh(&sk->sk_receive_queue.lock);
3527 spin_lock_bh(&sk->sk_write_queue.lock);
3528 if (po->tx_ring.pg_vec) {
3529 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3530 mask |= POLLOUT | POLLWRNORM;
3531 }
3532 spin_unlock_bh(&sk->sk_write_queue.lock);
3533 return mask;
3534 }
3535
3536
3537 /* Dirty? Well, I still did not learn better way to account
3538 * for user mmaps.
3539 */
3540
3541 static void packet_mm_open(struct vm_area_struct *vma)
3542 {
3543 struct file *file = vma->vm_file;
3544 struct socket *sock = file->private_data;
3545 struct sock *sk = sock->sk;
3546
3547 if (sk)
3548 atomic_inc(&pkt_sk(sk)->mapped);
3549 }
3550
3551 static void packet_mm_close(struct vm_area_struct *vma)
3552 {
3553 struct file *file = vma->vm_file;
3554 struct socket *sock = file->private_data;
3555 struct sock *sk = sock->sk;
3556
3557 if (sk)
3558 atomic_dec(&pkt_sk(sk)->mapped);
3559 }
3560
3561 static const struct vm_operations_struct packet_mmap_ops = {
3562 .open = packet_mm_open,
3563 .close = packet_mm_close,
3564 };
3565
3566 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3567 unsigned int len)
3568 {
3569 int i;
3570
3571 for (i = 0; i < len; i++) {
3572 if (likely(pg_vec[i].buffer)) {
3573 if (is_vmalloc_addr(pg_vec[i].buffer))
3574 vfree(pg_vec[i].buffer);
3575 else
3576 free_pages((unsigned long)pg_vec[i].buffer,
3577 order);
3578 pg_vec[i].buffer = NULL;
3579 }
3580 }
3581 kfree(pg_vec);
3582 }
3583
3584 static char *alloc_one_pg_vec_page(unsigned long order)
3585 {
3586 char *buffer = NULL;
3587 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3588 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3589
3590 buffer = (char *) __get_free_pages(gfp_flags, order);
3591
3592 if (buffer)
3593 return buffer;
3594
3595 /*
3596 * __get_free_pages failed, fall back to vmalloc
3597 */
3598 buffer = vzalloc((1 << order) * PAGE_SIZE);
3599
3600 if (buffer)
3601 return buffer;
3602
3603 /*
3604 * vmalloc failed, lets dig into swap here
3605 */
3606 gfp_flags &= ~__GFP_NORETRY;
3607 buffer = (char *)__get_free_pages(gfp_flags, order);
3608 if (buffer)
3609 return buffer;
3610
3611 /*
3612 * complete and utter failure
3613 */
3614 return NULL;
3615 }
3616
3617 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3618 {
3619 unsigned int block_nr = req->tp_block_nr;
3620 struct pgv *pg_vec;
3621 int i;
3622
3623 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3624 if (unlikely(!pg_vec))
3625 goto out;
3626
3627 for (i = 0; i < block_nr; i++) {
3628 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3629 if (unlikely(!pg_vec[i].buffer))
3630 goto out_free_pgvec;
3631 }
3632
3633 out:
3634 return pg_vec;
3635
3636 out_free_pgvec:
3637 free_pg_vec(pg_vec, order, block_nr);
3638 pg_vec = NULL;
3639 goto out;
3640 }
3641
3642 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3643 int closing, int tx_ring)
3644 {
3645 struct pgv *pg_vec = NULL;
3646 struct packet_sock *po = pkt_sk(sk);
3647 int was_running, order = 0;
3648 struct packet_ring_buffer *rb;
3649 struct sk_buff_head *rb_queue;
3650 __be16 num;
3651 int err = -EINVAL;
3652 /* Added to avoid minimal code churn */
3653 struct tpacket_req *req = &req_u->req;
3654
3655 lock_sock(sk);
3656 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3657 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3658 WARN(1, "Tx-ring is not supported.\n");
3659 goto out;
3660 }
3661
3662 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3663 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3664
3665 err = -EBUSY;
3666 if (!closing) {
3667 if (atomic_read(&po->mapped))
3668 goto out;
3669 if (atomic_read(&rb->pending))
3670 goto out;
3671 }
3672
3673 if (req->tp_block_nr) {
3674 /* Sanity tests and some calculations */
3675 err = -EBUSY;
3676 if (unlikely(rb->pg_vec))
3677 goto out;
3678
3679 switch (po->tp_version) {
3680 case TPACKET_V1:
3681 po->tp_hdrlen = TPACKET_HDRLEN;
3682 break;
3683 case TPACKET_V2:
3684 po->tp_hdrlen = TPACKET2_HDRLEN;
3685 break;
3686 case TPACKET_V3:
3687 po->tp_hdrlen = TPACKET3_HDRLEN;
3688 break;
3689 }
3690
3691 err = -EINVAL;
3692 if (unlikely((int)req->tp_block_size <= 0))
3693 goto out;
3694 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3695 goto out;
3696 if (po->tp_version >= TPACKET_V3 &&
3697 req->tp_block_size <=
3698 BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv))
3699 goto out;
3700 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3701 po->tp_reserve))
3702 goto out;
3703 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3704 goto out;
3705
3706 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3707 if (unlikely(rb->frames_per_block <= 0))
3708 goto out;
3709 if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr))
3710 goto out;
3711 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3712 req->tp_frame_nr))
3713 goto out;
3714
3715 err = -ENOMEM;
3716 order = get_order(req->tp_block_size);
3717 pg_vec = alloc_pg_vec(req, order);
3718 if (unlikely(!pg_vec))
3719 goto out;
3720 switch (po->tp_version) {
3721 case TPACKET_V3:
3722 /* Transmit path is not supported. We checked
3723 * it above but just being paranoid
3724 */
3725 if (!tx_ring)
3726 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3727 break;
3728 default:
3729 break;
3730 }
3731 }
3732 /* Done */
3733 else {
3734 err = -EINVAL;
3735 if (unlikely(req->tp_frame_nr))
3736 goto out;
3737 }
3738
3739
3740 /* Detach socket from network */
3741 spin_lock(&po->bind_lock);
3742 was_running = po->running;
3743 num = po->num;
3744 if (was_running) {
3745 po->num = 0;
3746 __unregister_prot_hook(sk, false);
3747 }
3748 spin_unlock(&po->bind_lock);
3749
3750 synchronize_net();
3751
3752 err = -EBUSY;
3753 mutex_lock(&po->pg_vec_lock);
3754 if (closing || atomic_read(&po->mapped) == 0) {
3755 err = 0;
3756 spin_lock_bh(&rb_queue->lock);
3757 swap(rb->pg_vec, pg_vec);
3758 rb->frame_max = (req->tp_frame_nr - 1);
3759 rb->head = 0;
3760 rb->frame_size = req->tp_frame_size;
3761 spin_unlock_bh(&rb_queue->lock);
3762
3763 swap(rb->pg_vec_order, order);
3764 swap(rb->pg_vec_len, req->tp_block_nr);
3765
3766 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3767 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3768 tpacket_rcv : packet_rcv;
3769 skb_queue_purge(rb_queue);
3770 if (atomic_read(&po->mapped))
3771 pr_err("packet_mmap: vma is busy: %d\n",
3772 atomic_read(&po->mapped));
3773 }
3774 mutex_unlock(&po->pg_vec_lock);
3775
3776 spin_lock(&po->bind_lock);
3777 if (was_running) {
3778 po->num = num;
3779 register_prot_hook(sk);
3780 }
3781 spin_unlock(&po->bind_lock);
3782 if (closing && (po->tp_version > TPACKET_V2)) {
3783 /* Because we don't support block-based V3 on tx-ring */
3784 if (!tx_ring)
3785 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3786 }
3787
3788 if (pg_vec)
3789 free_pg_vec(pg_vec, order, req->tp_block_nr);
3790 out:
3791 release_sock(sk);
3792 return err;
3793 }
3794
3795 static int packet_mmap(struct file *file, struct socket *sock,
3796 struct vm_area_struct *vma)
3797 {
3798 struct sock *sk = sock->sk;
3799 struct packet_sock *po = pkt_sk(sk);
3800 unsigned long size, expected_size;
3801 struct packet_ring_buffer *rb;
3802 unsigned long start;
3803 int err = -EINVAL;
3804 int i;
3805
3806 if (vma->vm_pgoff)
3807 return -EINVAL;
3808
3809 mutex_lock(&po->pg_vec_lock);
3810
3811 expected_size = 0;
3812 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3813 if (rb->pg_vec) {
3814 expected_size += rb->pg_vec_len
3815 * rb->pg_vec_pages
3816 * PAGE_SIZE;
3817 }
3818 }
3819
3820 if (expected_size == 0)
3821 goto out;
3822
3823 size = vma->vm_end - vma->vm_start;
3824 if (size != expected_size)
3825 goto out;
3826
3827 start = vma->vm_start;
3828 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3829 if (rb->pg_vec == NULL)
3830 continue;
3831
3832 for (i = 0; i < rb->pg_vec_len; i++) {
3833 struct page *page;
3834 void *kaddr = rb->pg_vec[i].buffer;
3835 int pg_num;
3836
3837 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3838 page = pgv_to_page(kaddr);
3839 err = vm_insert_page(vma, start, page);
3840 if (unlikely(err))
3841 goto out;
3842 start += PAGE_SIZE;
3843 kaddr += PAGE_SIZE;
3844 }
3845 }
3846 }
3847
3848 atomic_inc(&po->mapped);
3849 vma->vm_ops = &packet_mmap_ops;
3850 err = 0;
3851
3852 out:
3853 mutex_unlock(&po->pg_vec_lock);
3854 return err;
3855 }
3856
3857 static const struct proto_ops packet_ops_spkt = {
3858 .family = PF_PACKET,
3859 .owner = THIS_MODULE,
3860 .release = packet_release,
3861 .bind = packet_bind_spkt,
3862 .connect = sock_no_connect,
3863 .socketpair = sock_no_socketpair,
3864 .accept = sock_no_accept,
3865 .getname = packet_getname_spkt,
3866 .poll = datagram_poll,
3867 .ioctl = packet_ioctl,
3868 .listen = sock_no_listen,
3869 .shutdown = sock_no_shutdown,
3870 .setsockopt = sock_no_setsockopt,
3871 .getsockopt = sock_no_getsockopt,
3872 .sendmsg = packet_sendmsg_spkt,
3873 .recvmsg = packet_recvmsg,
3874 .mmap = sock_no_mmap,
3875 .sendpage = sock_no_sendpage,
3876 };
3877
3878 static const struct proto_ops packet_ops = {
3879 .family = PF_PACKET,
3880 .owner = THIS_MODULE,
3881 .release = packet_release,
3882 .bind = packet_bind,
3883 .connect = sock_no_connect,
3884 .socketpair = sock_no_socketpair,
3885 .accept = sock_no_accept,
3886 .getname = packet_getname,
3887 .poll = packet_poll,
3888 .ioctl = packet_ioctl,
3889 .listen = sock_no_listen,
3890 .shutdown = sock_no_shutdown,
3891 .setsockopt = packet_setsockopt,
3892 .getsockopt = packet_getsockopt,
3893 .sendmsg = packet_sendmsg,
3894 .recvmsg = packet_recvmsg,
3895 .mmap = packet_mmap,
3896 .sendpage = sock_no_sendpage,
3897 };
3898
3899 static const struct net_proto_family packet_family_ops = {
3900 .family = PF_PACKET,
3901 .create = packet_create,
3902 .owner = THIS_MODULE,
3903 };
3904
3905 static struct notifier_block packet_netdev_notifier = {
3906 .notifier_call = packet_notifier,
3907 };
3908
3909 #ifdef CONFIG_PROC_FS
3910
3911 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3912 __acquires(RCU)
3913 {
3914 struct net *net = seq_file_net(seq);
3915
3916 rcu_read_lock();
3917 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3918 }
3919
3920 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3921 {
3922 struct net *net = seq_file_net(seq);
3923 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3924 }
3925
3926 static void packet_seq_stop(struct seq_file *seq, void *v)
3927 __releases(RCU)
3928 {
3929 rcu_read_unlock();
3930 }
3931
3932 static int packet_seq_show(struct seq_file *seq, void *v)
3933 {
3934 if (v == SEQ_START_TOKEN)
3935 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3936 else {
3937 struct sock *s = sk_entry(v);
3938 const struct packet_sock *po = pkt_sk(s);
3939
3940 seq_printf(seq,
3941 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3942 s,
3943 atomic_read(&s->sk_refcnt),
3944 s->sk_type,
3945 ntohs(po->num),
3946 po->ifindex,
3947 po->running,
3948 atomic_read(&s->sk_rmem_alloc),
3949 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3950 sock_i_ino(s));
3951 }
3952
3953 return 0;
3954 }
3955
3956 static const struct seq_operations packet_seq_ops = {
3957 .start = packet_seq_start,
3958 .next = packet_seq_next,
3959 .stop = packet_seq_stop,
3960 .show = packet_seq_show,
3961 };
3962
3963 static int packet_seq_open(struct inode *inode, struct file *file)
3964 {
3965 return seq_open_net(inode, file, &packet_seq_ops,
3966 sizeof(struct seq_net_private));
3967 }
3968
3969 static const struct file_operations packet_seq_fops = {
3970 .owner = THIS_MODULE,
3971 .open = packet_seq_open,
3972 .read = seq_read,
3973 .llseek = seq_lseek,
3974 .release = seq_release_net,
3975 };
3976
3977 #endif
3978
3979 static int __net_init packet_net_init(struct net *net)
3980 {
3981 mutex_init(&net->packet.sklist_lock);
3982 INIT_HLIST_HEAD(&net->packet.sklist);
3983
3984 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
3985 return -ENOMEM;
3986
3987 return 0;
3988 }
3989
3990 static void __net_exit packet_net_exit(struct net *net)
3991 {
3992 remove_proc_entry("packet", net->proc_net);
3993 }
3994
3995 static struct pernet_operations packet_net_ops = {
3996 .init = packet_net_init,
3997 .exit = packet_net_exit,
3998 };
3999
4000
4001 static void __exit packet_exit(void)
4002 {
4003 unregister_netdevice_notifier(&packet_netdev_notifier);
4004 unregister_pernet_subsys(&packet_net_ops);
4005 sock_unregister(PF_PACKET);
4006 proto_unregister(&packet_proto);
4007 }
4008
4009 static int __init packet_init(void)
4010 {
4011 int rc = proto_register(&packet_proto, 0);
4012
4013 if (rc != 0)
4014 goto out;
4015
4016 sock_register(&packet_family_ops);
4017 register_pernet_subsys(&packet_net_ops);
4018 register_netdevice_notifier(&packet_netdev_notifier);
4019 out:
4020 return rc;
4021 }
4022
4023 module_init(packet_init);
4024 module_exit(packet_exit);
4025 MODULE_LICENSE("GPL");
4026 MODULE_ALIAS_NETPROTO(PF_PACKET);