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Linux 3.12.28
[linux/fpc-iii.git] / net / packet / af_packet.c
blob88cfbc189558f75b4b508b849827eea18c3be7c0
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PACKET - implements raw packet sockets.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 *
12 * Fixes:
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
41 * and packet_mreq.
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
44 * layer.
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
46 *
47 *
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
52 *
53 */
54
55 #include <linux/types.h>
56 #include <linux/mm.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
60 #include <linux/in.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
70 #include <net/ip.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
73 #include <net/sock.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <asm/uaccess.h>
77 #include <asm/ioctls.h>
78 #include <asm/page.h>
79 #include <asm/cacheflush.h>
80 #include <asm/io.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91 #include <linux/reciprocal_div.h>
92 #ifdef CONFIG_INET
93 #include <net/inet_common.h>
94 #endif
95
96 #include "internal.h"
97
98 /*
99 Assumptions:
100 - if device has no dev->hard_header routine, it adds and removes ll header
101 inside itself. In this case ll header is invisible outside of device,
102 but higher levels still should reserve dev->hard_header_len.
103 Some devices are enough clever to reallocate skb, when header
104 will not fit to reserved space (tunnel), another ones are silly
105 (PPP).
106 - packet socket receives packets with pulled ll header,
107 so that SOCK_RAW should push it back.
108
109 On receive:
110 -----------
111
112 Incoming, dev->hard_header!=NULL
113 mac_header -> ll header
114 data -> data
115
116 Outgoing, dev->hard_header!=NULL
117 mac_header -> ll header
118 data -> ll header
119
120 Incoming, dev->hard_header==NULL
121 mac_header -> UNKNOWN position. It is very likely, that it points to ll
122 header. PPP makes it, that is wrong, because introduce
123 assymetry between rx and tx paths.
124 data -> data
125
126 Outgoing, dev->hard_header==NULL
127 mac_header -> data. ll header is still not built!
128 data -> data
129
130 Resume
131 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
132
133
134 On transmit:
135 ------------
136
137 dev->hard_header != NULL
138 mac_header -> ll header
139 data -> ll header
140
141 dev->hard_header == NULL (ll header is added by device, we cannot control it)
142 mac_header -> data
143 data -> data
144
145 We should set nh.raw on output to correct posistion,
146 packet classifier depends on it.
147 */
148
149 /* Private packet socket structures. */
150
151 /* identical to struct packet_mreq except it has
152 * a longer address field.
153 */
154 struct packet_mreq_max {
155 int mr_ifindex;
156 unsigned short mr_type;
157 unsigned short mr_alen;
158 unsigned char mr_address[MAX_ADDR_LEN];
159 };
160
161 union tpacket_uhdr {
162 struct tpacket_hdr *h1;
163 struct tpacket2_hdr *h2;
164 struct tpacket3_hdr *h3;
165 void *raw;
166 };
167
168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
169 int closing, int tx_ring);
170
171 #define V3_ALIGNMENT (8)
172
173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
174
175 #define BLK_PLUS_PRIV(sz_of_priv) \
176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
177
178 #define PGV_FROM_VMALLOC 1
179
180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
187
188 struct packet_sock;
189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
191 struct packet_type *pt, struct net_device *orig_dev);
192
193 static void *packet_previous_frame(struct packet_sock *po,
194 struct packet_ring_buffer *rb,
195 int status);
196 static void packet_increment_head(struct packet_ring_buffer *buff);
197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
198 struct tpacket_block_desc *);
199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200 struct packet_sock *);
201 static void prb_retire_current_block(struct tpacket_kbdq_core *,
202 struct packet_sock *, unsigned int status);
203 static int prb_queue_frozen(struct tpacket_kbdq_core *);
204 static void prb_open_block(struct tpacket_kbdq_core *,
205 struct tpacket_block_desc *);
206 static void prb_retire_rx_blk_timer_expired(unsigned long);
207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208 static void prb_init_blk_timer(struct packet_sock *,
209 struct tpacket_kbdq_core *,
210 void (*func) (unsigned long));
211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
212 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
213 struct tpacket3_hdr *);
214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
215 struct tpacket3_hdr *);
216 static void packet_flush_mclist(struct sock *sk);
217
218 struct packet_skb_cb {
219 unsigned int origlen;
220 union {
221 struct sockaddr_pkt pkt;
222 struct sockaddr_ll ll;
223 } sa;
224 };
225
226 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
227
228 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
229 #define GET_PBLOCK_DESC(x, bid) \
230 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
232 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
233 #define GET_NEXT_PRB_BLK_NUM(x) \
234 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
235 ((x)->kactive_blk_num+1) : 0)
236
237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
238 static void __fanout_link(struct sock *sk, struct packet_sock *po);
239
240 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 prb_init_ft_ops(p1, req_u);
569 prb_setup_retire_blk_timer(po, tx_ring);
570 prb_open_block(p1, pbd);
571 }
572
573 /* Do NOT update the last_blk_num first.
574 * Assumes sk_buff_head lock is held.
575 */
576 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
577 {
578 mod_timer(&pkc->retire_blk_timer,
579 jiffies + pkc->tov_in_jiffies);
580 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
581 }
582
583 /*
584 * Timer logic:
585 * 1) We refresh the timer only when we open a block.
586 * By doing this we don't waste cycles refreshing the timer
587 * on packet-by-packet basis.
588 *
589 * With a 1MB block-size, on a 1Gbps line, it will take
590 * i) ~8 ms to fill a block + ii) memcpy etc.
591 * In this cut we are not accounting for the memcpy time.
592 *
593 * So, if the user sets the 'tmo' to 10ms then the timer
594 * will never fire while the block is still getting filled
595 * (which is what we want). However, the user could choose
596 * to close a block early and that's fine.
597 *
598 * But when the timer does fire, we check whether or not to refresh it.
599 * Since the tmo granularity is in msecs, it is not too expensive
600 * to refresh the timer, lets say every '8' msecs.
601 * Either the user can set the 'tmo' or we can derive it based on
602 * a) line-speed and b) block-size.
603 * prb_calc_retire_blk_tmo() calculates the tmo.
604 *
605 */
606 static void prb_retire_rx_blk_timer_expired(unsigned long data)
607 {
608 struct packet_sock *po = (struct packet_sock *)data;
609 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
610 unsigned int frozen;
611 struct tpacket_block_desc *pbd;
612
613 spin_lock(&po->sk.sk_receive_queue.lock);
614
615 frozen = prb_queue_frozen(pkc);
616 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
617
618 if (unlikely(pkc->delete_blk_timer))
619 goto out;
620
621 /* We only need to plug the race when the block is partially filled.
622 * tpacket_rcv:
623 * lock(); increment BLOCK_NUM_PKTS; unlock()
624 * copy_bits() is in progress ...
625 * timer fires on other cpu:
626 * we can't retire the current block because copy_bits
627 * is in progress.
628 *
629 */
630 if (BLOCK_NUM_PKTS(pbd)) {
631 while (atomic_read(&pkc->blk_fill_in_prog)) {
632 /* Waiting for skb_copy_bits to finish... */
633 cpu_relax();
634 }
635 }
636
637 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
638 if (!frozen) {
639 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
640 if (!prb_dispatch_next_block(pkc, po))
641 goto refresh_timer;
642 else
643 goto out;
644 } else {
645 /* Case 1. Queue was frozen because user-space was
646 * lagging behind.
647 */
648 if (prb_curr_blk_in_use(pkc, pbd)) {
649 /*
650 * Ok, user-space is still behind.
651 * So just refresh the timer.
652 */
653 goto refresh_timer;
654 } else {
655 /* Case 2. queue was frozen,user-space caught up,
656 * now the link went idle && the timer fired.
657 * We don't have a block to close.So we open this
658 * block and restart the timer.
659 * opening a block thaws the queue,restarts timer
660 * Thawing/timer-refresh is a side effect.
661 */
662 prb_open_block(pkc, pbd);
663 goto out;
664 }
665 }
666 }
667
668 refresh_timer:
669 _prb_refresh_rx_retire_blk_timer(pkc);
670
671 out:
672 spin_unlock(&po->sk.sk_receive_queue.lock);
673 }
674
675 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
676 struct tpacket_block_desc *pbd1, __u32 status)
677 {
678 /* Flush everything minus the block header */
679
680 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
681 u8 *start, *end;
682
683 start = (u8 *)pbd1;
684
685 /* Skip the block header(we know header WILL fit in 4K) */
686 start += PAGE_SIZE;
687
688 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
689 for (; start < end; start += PAGE_SIZE)
690 flush_dcache_page(pgv_to_page(start));
691
692 smp_wmb();
693 #endif
694
695 /* Now update the block status. */
696
697 BLOCK_STATUS(pbd1) = status;
698
699 /* Flush the block header */
700
701 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
702 start = (u8 *)pbd1;
703 flush_dcache_page(pgv_to_page(start));
704
705 smp_wmb();
706 #endif
707 }
708
709 /*
710 * Side effect:
711 *
712 * 1) flush the block
713 * 2) Increment active_blk_num
714 *
715 * Note:We DONT refresh the timer on purpose.
716 * Because almost always the next block will be opened.
717 */
718 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
719 struct tpacket_block_desc *pbd1,
720 struct packet_sock *po, unsigned int stat)
721 {
722 __u32 status = TP_STATUS_USER | stat;
723
724 struct tpacket3_hdr *last_pkt;
725 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
726
727 if (po->stats.stats3.tp_drops)
728 status |= TP_STATUS_LOSING;
729
730 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
731 last_pkt->tp_next_offset = 0;
732
733 /* Get the ts of the last pkt */
734 if (BLOCK_NUM_PKTS(pbd1)) {
735 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
736 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
737 } else {
738 /* Ok, we tmo'd - so get the current time */
739 struct timespec ts;
740 getnstimeofday(&ts);
741 h1->ts_last_pkt.ts_sec = ts.tv_sec;
742 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
743 }
744
745 smp_wmb();
746
747 /* Flush the block */
748 prb_flush_block(pkc1, pbd1, status);
749
750 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
751 }
752
753 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
754 {
755 pkc->reset_pending_on_curr_blk = 0;
756 }
757
758 /*
759 * Side effect of opening a block:
760 *
761 * 1) prb_queue is thawed.
762 * 2) retire_blk_timer is refreshed.
763 *
764 */
765 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
766 struct tpacket_block_desc *pbd1)
767 {
768 struct timespec ts;
769 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
770
771 smp_rmb();
772
773 /* We could have just memset this but we will lose the
774 * flexibility of making the priv area sticky
775 */
776
777 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
778 BLOCK_NUM_PKTS(pbd1) = 0;
779 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
780
781 getnstimeofday(&ts);
782
783 h1->ts_first_pkt.ts_sec = ts.tv_sec;
784 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
785
786 pkc1->pkblk_start = (char *)pbd1;
787 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
788
789 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
790 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
791
792 pbd1->version = pkc1->version;
793 pkc1->prev = pkc1->nxt_offset;
794 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
795
796 prb_thaw_queue(pkc1);
797 _prb_refresh_rx_retire_blk_timer(pkc1);
798
799 smp_wmb();
800 }
801
802 /*
803 * Queue freeze logic:
804 * 1) Assume tp_block_nr = 8 blocks.
805 * 2) At time 't0', user opens Rx ring.
806 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
807 * 4) user-space is either sleeping or processing block '0'.
808 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
809 * it will close block-7,loop around and try to fill block '0'.
810 * call-flow:
811 * __packet_lookup_frame_in_block
812 * prb_retire_current_block()
813 * prb_dispatch_next_block()
814 * |->(BLOCK_STATUS == USER) evaluates to true
815 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
816 * 6) Now there are two cases:
817 * 6.1) Link goes idle right after the queue is frozen.
818 * But remember, the last open_block() refreshed the timer.
819 * When this timer expires,it will refresh itself so that we can
820 * re-open block-0 in near future.
821 * 6.2) Link is busy and keeps on receiving packets. This is a simple
822 * case and __packet_lookup_frame_in_block will check if block-0
823 * is free and can now be re-used.
824 */
825 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
826 struct packet_sock *po)
827 {
828 pkc->reset_pending_on_curr_blk = 1;
829 po->stats.stats3.tp_freeze_q_cnt++;
830 }
831
832 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
833
834 /*
835 * If the next block is free then we will dispatch it
836 * and return a good offset.
837 * Else, we will freeze the queue.
838 * So, caller must check the return value.
839 */
840 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
841 struct packet_sock *po)
842 {
843 struct tpacket_block_desc *pbd;
844
845 smp_rmb();
846
847 /* 1. Get current block num */
848 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
849
850 /* 2. If this block is currently in_use then freeze the queue */
851 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
852 prb_freeze_queue(pkc, po);
853 return NULL;
854 }
855
856 /*
857 * 3.
858 * open this block and return the offset where the first packet
859 * needs to get stored.
860 */
861 prb_open_block(pkc, pbd);
862 return (void *)pkc->nxt_offset;
863 }
864
865 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
866 struct packet_sock *po, unsigned int status)
867 {
868 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
869
870 /* retire/close the current block */
871 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
872 /*
873 * Plug the case where copy_bits() is in progress on
874 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
875 * have space to copy the pkt in the current block and
876 * called prb_retire_current_block()
877 *
878 * We don't need to worry about the TMO case because
879 * the timer-handler already handled this case.
880 */
881 if (!(status & TP_STATUS_BLK_TMO)) {
882 while (atomic_read(&pkc->blk_fill_in_prog)) {
883 /* Waiting for skb_copy_bits to finish... */
884 cpu_relax();
885 }
886 }
887 prb_close_block(pkc, pbd, po, status);
888 return;
889 }
890 }
891
892 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
893 struct tpacket_block_desc *pbd)
894 {
895 return TP_STATUS_USER & BLOCK_STATUS(pbd);
896 }
897
898 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
899 {
900 return pkc->reset_pending_on_curr_blk;
901 }
902
903 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
904 {
905 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
906 atomic_dec(&pkc->blk_fill_in_prog);
907 }
908
909 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
910 struct tpacket3_hdr *ppd)
911 {
912 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
913 }
914
915 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
916 struct tpacket3_hdr *ppd)
917 {
918 ppd->hv1.tp_rxhash = 0;
919 }
920
921 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
922 struct tpacket3_hdr *ppd)
923 {
924 if (vlan_tx_tag_present(pkc->skb)) {
925 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
926 ppd->tp_status = TP_STATUS_VLAN_VALID;
927 } else {
928 ppd->hv1.tp_vlan_tci = 0;
929 ppd->tp_status = TP_STATUS_AVAILABLE;
930 }
931 }
932
933 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
934 struct tpacket3_hdr *ppd)
935 {
936 prb_fill_vlan_info(pkc, ppd);
937
938 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
939 prb_fill_rxhash(pkc, ppd);
940 else
941 prb_clear_rxhash(pkc, ppd);
942 }
943
944 static void prb_fill_curr_block(char *curr,
945 struct tpacket_kbdq_core *pkc,
946 struct tpacket_block_desc *pbd,
947 unsigned int len)
948 {
949 struct tpacket3_hdr *ppd;
950
951 ppd = (struct tpacket3_hdr *)curr;
952 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
953 pkc->prev = curr;
954 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
955 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
956 BLOCK_NUM_PKTS(pbd) += 1;
957 atomic_inc(&pkc->blk_fill_in_prog);
958 prb_run_all_ft_ops(pkc, ppd);
959 }
960
961 /* Assumes caller has the sk->rx_queue.lock */
962 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
963 struct sk_buff *skb,
964 int status,
965 unsigned int len
966 )
967 {
968 struct tpacket_kbdq_core *pkc;
969 struct tpacket_block_desc *pbd;
970 char *curr, *end;
971
972 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
973 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
974
975 /* Queue is frozen when user space is lagging behind */
976 if (prb_queue_frozen(pkc)) {
977 /*
978 * Check if that last block which caused the queue to freeze,
979 * is still in_use by user-space.
980 */
981 if (prb_curr_blk_in_use(pkc, pbd)) {
982 /* Can't record this packet */
983 return NULL;
984 } else {
985 /*
986 * Ok, the block was released by user-space.
987 * Now let's open that block.
988 * opening a block also thaws the queue.
989 * Thawing is a side effect.
990 */
991 prb_open_block(pkc, pbd);
992 }
993 }
994
995 smp_mb();
996 curr = pkc->nxt_offset;
997 pkc->skb = skb;
998 end = (char *)pbd + pkc->kblk_size;
999
1000 /* first try the current block */
1001 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1002 prb_fill_curr_block(curr, pkc, pbd, len);
1003 return (void *)curr;
1004 }
1005
1006 /* Ok, close the current block */
1007 prb_retire_current_block(pkc, po, 0);
1008
1009 /* Now, try to dispatch the next block */
1010 curr = (char *)prb_dispatch_next_block(pkc, po);
1011 if (curr) {
1012 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1013 prb_fill_curr_block(curr, pkc, pbd, len);
1014 return (void *)curr;
1015 }
1016
1017 /*
1018 * No free blocks are available.user_space hasn't caught up yet.
1019 * Queue was just frozen and now this packet will get dropped.
1020 */
1021 return NULL;
1022 }
1023
1024 static void *packet_current_rx_frame(struct packet_sock *po,
1025 struct sk_buff *skb,
1026 int status, unsigned int len)
1027 {
1028 char *curr = NULL;
1029 switch (po->tp_version) {
1030 case TPACKET_V1:
1031 case TPACKET_V2:
1032 curr = packet_lookup_frame(po, &po->rx_ring,
1033 po->rx_ring.head, status);
1034 return curr;
1035 case TPACKET_V3:
1036 return __packet_lookup_frame_in_block(po, skb, status, len);
1037 default:
1038 WARN(1, "TPACKET version not supported\n");
1039 BUG();
1040 return NULL;
1041 }
1042 }
1043
1044 static void *prb_lookup_block(struct packet_sock *po,
1045 struct packet_ring_buffer *rb,
1046 unsigned int idx,
1047 int status)
1048 {
1049 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1050 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1051
1052 if (status != BLOCK_STATUS(pbd))
1053 return NULL;
1054 return pbd;
1055 }
1056
1057 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1058 {
1059 unsigned int prev;
1060 if (rb->prb_bdqc.kactive_blk_num)
1061 prev = rb->prb_bdqc.kactive_blk_num-1;
1062 else
1063 prev = rb->prb_bdqc.knum_blocks-1;
1064 return prev;
1065 }
1066
1067 /* Assumes caller has held the rx_queue.lock */
1068 static void *__prb_previous_block(struct packet_sock *po,
1069 struct packet_ring_buffer *rb,
1070 int status)
1071 {
1072 unsigned int previous = prb_previous_blk_num(rb);
1073 return prb_lookup_block(po, rb, previous, status);
1074 }
1075
1076 static void *packet_previous_rx_frame(struct packet_sock *po,
1077 struct packet_ring_buffer *rb,
1078 int status)
1079 {
1080 if (po->tp_version <= TPACKET_V2)
1081 return packet_previous_frame(po, rb, status);
1082
1083 return __prb_previous_block(po, rb, status);
1084 }
1085
1086 static void packet_increment_rx_head(struct packet_sock *po,
1087 struct packet_ring_buffer *rb)
1088 {
1089 switch (po->tp_version) {
1090 case TPACKET_V1:
1091 case TPACKET_V2:
1092 return packet_increment_head(rb);
1093 case TPACKET_V3:
1094 default:
1095 WARN(1, "TPACKET version not supported.\n");
1096 BUG();
1097 return;
1098 }
1099 }
1100
1101 static void *packet_previous_frame(struct packet_sock *po,
1102 struct packet_ring_buffer *rb,
1103 int status)
1104 {
1105 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1106 return packet_lookup_frame(po, rb, previous, status);
1107 }
1108
1109 static void packet_increment_head(struct packet_ring_buffer *buff)
1110 {
1111 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1112 }
1113
1114 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1115 {
1116 struct sock *sk = &po->sk;
1117 bool has_room;
1118
1119 if (po->prot_hook.func != tpacket_rcv)
1120 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
1121 <= sk->sk_rcvbuf;
1122
1123 spin_lock(&sk->sk_receive_queue.lock);
1124 if (po->tp_version == TPACKET_V3)
1125 has_room = prb_lookup_block(po, &po->rx_ring,
1126 po->rx_ring.prb_bdqc.kactive_blk_num,
1127 TP_STATUS_KERNEL);
1128 else
1129 has_room = packet_lookup_frame(po, &po->rx_ring,
1130 po->rx_ring.head,
1131 TP_STATUS_KERNEL);
1132 spin_unlock(&sk->sk_receive_queue.lock);
1133
1134 return has_room;
1135 }
1136
1137 static void packet_sock_destruct(struct sock *sk)
1138 {
1139 skb_queue_purge(&sk->sk_error_queue);
1140
1141 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1142 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1143
1144 if (!sock_flag(sk, SOCK_DEAD)) {
1145 pr_err("Attempt to release alive packet socket: %p\n", sk);
1146 return;
1147 }
1148
1149 sk_refcnt_debug_dec(sk);
1150 }
1151
1152 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1153 {
1154 int x = atomic_read(&f->rr_cur) + 1;
1155
1156 if (x >= num)
1157 x = 0;
1158
1159 return x;
1160 }
1161
1162 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1163 struct sk_buff *skb,
1164 unsigned int num)
1165 {
1166 return reciprocal_divide(skb->rxhash, num);
1167 }
1168
1169 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1170 struct sk_buff *skb,
1171 unsigned int num)
1172 {
1173 int cur, old;
1174
1175 cur = atomic_read(&f->rr_cur);
1176 while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1177 fanout_rr_next(f, num))) != cur)
1178 cur = old;
1179 return cur;
1180 }
1181
1182 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1183 struct sk_buff *skb,
1184 unsigned int num)
1185 {
1186 return smp_processor_id() % num;
1187 }
1188
1189 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1190 struct sk_buff *skb,
1191 unsigned int num)
1192 {
1193 return reciprocal_divide(prandom_u32(), num);
1194 }
1195
1196 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1197 struct sk_buff *skb,
1198 unsigned int idx, unsigned int skip,
1199 unsigned int num)
1200 {
1201 unsigned int i, j;
1202
1203 i = j = min_t(int, f->next[idx], num - 1);
1204 do {
1205 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1206 if (i != j)
1207 f->next[idx] = i;
1208 return i;
1209 }
1210 if (++i == num)
1211 i = 0;
1212 } while (i != j);
1213
1214 return idx;
1215 }
1216
1217 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1218 {
1219 return f->flags & (flag >> 8);
1220 }
1221
1222 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1223 struct packet_type *pt, struct net_device *orig_dev)
1224 {
1225 struct packet_fanout *f = pt->af_packet_priv;
1226 unsigned int num = f->num_members;
1227 struct packet_sock *po;
1228 unsigned int idx;
1229
1230 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1231 !num) {
1232 kfree_skb(skb);
1233 return 0;
1234 }
1235
1236 switch (f->type) {
1237 case PACKET_FANOUT_HASH:
1238 default:
1239 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1240 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1241 if (!skb)
1242 return 0;
1243 }
1244 skb_get_rxhash(skb);
1245 idx = fanout_demux_hash(f, skb, num);
1246 break;
1247 case PACKET_FANOUT_LB:
1248 idx = fanout_demux_lb(f, skb, num);
1249 break;
1250 case PACKET_FANOUT_CPU:
1251 idx = fanout_demux_cpu(f, skb, num);
1252 break;
1253 case PACKET_FANOUT_RND:
1254 idx = fanout_demux_rnd(f, skb, num);
1255 break;
1256 case PACKET_FANOUT_ROLLOVER:
1257 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1258 break;
1259 }
1260
1261 po = pkt_sk(f->arr[idx]);
1262 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1263 unlikely(!packet_rcv_has_room(po, skb))) {
1264 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1265 po = pkt_sk(f->arr[idx]);
1266 }
1267
1268 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1269 }
1270
1271 DEFINE_MUTEX(fanout_mutex);
1272 EXPORT_SYMBOL_GPL(fanout_mutex);
1273 static LIST_HEAD(fanout_list);
1274
1275 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1276 {
1277 struct packet_fanout *f = po->fanout;
1278
1279 spin_lock(&f->lock);
1280 f->arr[f->num_members] = sk;
1281 smp_wmb();
1282 f->num_members++;
1283 spin_unlock(&f->lock);
1284 }
1285
1286 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1287 {
1288 struct packet_fanout *f = po->fanout;
1289 int i;
1290
1291 spin_lock(&f->lock);
1292 for (i = 0; i < f->num_members; i++) {
1293 if (f->arr[i] == sk)
1294 break;
1295 }
1296 BUG_ON(i >= f->num_members);
1297 f->arr[i] = f->arr[f->num_members - 1];
1298 f->num_members--;
1299 spin_unlock(&f->lock);
1300 }
1301
1302 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1303 {
1304 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1305 return true;
1306
1307 return false;
1308 }
1309
1310 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1311 {
1312 struct packet_sock *po = pkt_sk(sk);
1313 struct packet_fanout *f, *match;
1314 u8 type = type_flags & 0xff;
1315 u8 flags = type_flags >> 8;
1316 int err;
1317
1318 switch (type) {
1319 case PACKET_FANOUT_ROLLOVER:
1320 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1321 return -EINVAL;
1322 case PACKET_FANOUT_HASH:
1323 case PACKET_FANOUT_LB:
1324 case PACKET_FANOUT_CPU:
1325 case PACKET_FANOUT_RND:
1326 break;
1327 default:
1328 return -EINVAL;
1329 }
1330
1331 if (!po->running)
1332 return -EINVAL;
1333
1334 if (po->fanout)
1335 return -EALREADY;
1336
1337 mutex_lock(&fanout_mutex);
1338 match = NULL;
1339 list_for_each_entry(f, &fanout_list, list) {
1340 if (f->id == id &&
1341 read_pnet(&f->net) == sock_net(sk)) {
1342 match = f;
1343 break;
1344 }
1345 }
1346 err = -EINVAL;
1347 if (match && match->flags != flags)
1348 goto out;
1349 if (!match) {
1350 err = -ENOMEM;
1351 match = kzalloc(sizeof(*match), GFP_KERNEL);
1352 if (!match)
1353 goto out;
1354 write_pnet(&match->net, sock_net(sk));
1355 match->id = id;
1356 match->type = type;
1357 match->flags = flags;
1358 atomic_set(&match->rr_cur, 0);
1359 INIT_LIST_HEAD(&match->list);
1360 spin_lock_init(&match->lock);
1361 atomic_set(&match->sk_ref, 0);
1362 match->prot_hook.type = po->prot_hook.type;
1363 match->prot_hook.dev = po->prot_hook.dev;
1364 match->prot_hook.func = packet_rcv_fanout;
1365 match->prot_hook.af_packet_priv = match;
1366 match->prot_hook.id_match = match_fanout_group;
1367 dev_add_pack(&match->prot_hook);
1368 list_add(&match->list, &fanout_list);
1369 }
1370 err = -EINVAL;
1371 if (match->type == type &&
1372 match->prot_hook.type == po->prot_hook.type &&
1373 match->prot_hook.dev == po->prot_hook.dev) {
1374 err = -ENOSPC;
1375 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1376 __dev_remove_pack(&po->prot_hook);
1377 po->fanout = match;
1378 atomic_inc(&match->sk_ref);
1379 __fanout_link(sk, po);
1380 err = 0;
1381 }
1382 }
1383 out:
1384 mutex_unlock(&fanout_mutex);
1385 return err;
1386 }
1387
1388 static void fanout_release(struct sock *sk)
1389 {
1390 struct packet_sock *po = pkt_sk(sk);
1391 struct packet_fanout *f;
1392
1393 f = po->fanout;
1394 if (!f)
1395 return;
1396
1397 mutex_lock(&fanout_mutex);
1398 po->fanout = NULL;
1399
1400 if (atomic_dec_and_test(&f->sk_ref)) {
1401 list_del(&f->list);
1402 dev_remove_pack(&f->prot_hook);
1403 kfree(f);
1404 }
1405 mutex_unlock(&fanout_mutex);
1406 }
1407
1408 static const struct proto_ops packet_ops;
1409
1410 static const struct proto_ops packet_ops_spkt;
1411
1412 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1413 struct packet_type *pt, struct net_device *orig_dev)
1414 {
1415 struct sock *sk;
1416 struct sockaddr_pkt *spkt;
1417
1418 /*
1419 * When we registered the protocol we saved the socket in the data
1420 * field for just this event.
1421 */
1422
1423 sk = pt->af_packet_priv;
1424
1425 /*
1426 * Yank back the headers [hope the device set this
1427 * right or kerboom...]
1428 *
1429 * Incoming packets have ll header pulled,
1430 * push it back.
1431 *
1432 * For outgoing ones skb->data == skb_mac_header(skb)
1433 * so that this procedure is noop.
1434 */
1435
1436 if (skb->pkt_type == PACKET_LOOPBACK)
1437 goto out;
1438
1439 if (!net_eq(dev_net(dev), sock_net(sk)))
1440 goto out;
1441
1442 skb = skb_share_check(skb, GFP_ATOMIC);
1443 if (skb == NULL)
1444 goto oom;
1445
1446 /* drop any routing info */
1447 skb_dst_drop(skb);
1448
1449 /* drop conntrack reference */
1450 nf_reset(skb);
1451
1452 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1453
1454 skb_push(skb, skb->data - skb_mac_header(skb));
1455
1456 /*
1457 * The SOCK_PACKET socket receives _all_ frames.
1458 */
1459
1460 spkt->spkt_family = dev->type;
1461 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1462 spkt->spkt_protocol = skb->protocol;
1463
1464 /*
1465 * Charge the memory to the socket. This is done specifically
1466 * to prevent sockets using all the memory up.
1467 */
1468
1469 if (sock_queue_rcv_skb(sk, skb) == 0)
1470 return 0;
1471
1472 out:
1473 kfree_skb(skb);
1474 oom:
1475 return 0;
1476 }
1477
1478
1479 /*
1480 * Output a raw packet to a device layer. This bypasses all the other
1481 * protocol layers and you must therefore supply it with a complete frame
1482 */
1483
1484 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1485 struct msghdr *msg, size_t len)
1486 {
1487 struct sock *sk = sock->sk;
1488 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1489 struct sk_buff *skb = NULL;
1490 struct net_device *dev;
1491 __be16 proto = 0;
1492 int err;
1493 int extra_len = 0;
1494
1495 /*
1496 * Get and verify the address.
1497 */
1498
1499 if (saddr) {
1500 if (msg->msg_namelen < sizeof(struct sockaddr))
1501 return -EINVAL;
1502 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1503 proto = saddr->spkt_protocol;
1504 } else
1505 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1506
1507 /*
1508 * Find the device first to size check it
1509 */
1510
1511 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1512 retry:
1513 rcu_read_lock();
1514 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1515 err = -ENODEV;
1516 if (dev == NULL)
1517 goto out_unlock;
1518
1519 err = -ENETDOWN;
1520 if (!(dev->flags & IFF_UP))
1521 goto out_unlock;
1522
1523 /*
1524 * You may not queue a frame bigger than the mtu. This is the lowest level
1525 * raw protocol and you must do your own fragmentation at this level.
1526 */
1527
1528 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1529 if (!netif_supports_nofcs(dev)) {
1530 err = -EPROTONOSUPPORT;
1531 goto out_unlock;
1532 }
1533 extra_len = 4; /* We're doing our own CRC */
1534 }
1535
1536 err = -EMSGSIZE;
1537 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1538 goto out_unlock;
1539
1540 if (!skb) {
1541 size_t reserved = LL_RESERVED_SPACE(dev);
1542 int tlen = dev->needed_tailroom;
1543 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1544
1545 rcu_read_unlock();
1546 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1547 if (skb == NULL)
1548 return -ENOBUFS;
1549 /* FIXME: Save some space for broken drivers that write a hard
1550 * header at transmission time by themselves. PPP is the notable
1551 * one here. This should really be fixed at the driver level.
1552 */
1553 skb_reserve(skb, reserved);
1554 skb_reset_network_header(skb);
1555
1556 /* Try to align data part correctly */
1557 if (hhlen) {
1558 skb->data -= hhlen;
1559 skb->tail -= hhlen;
1560 if (len < hhlen)
1561 skb_reset_network_header(skb);
1562 }
1563 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1564 if (err)
1565 goto out_free;
1566 goto retry;
1567 }
1568
1569 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1570 /* Earlier code assumed this would be a VLAN pkt,
1571 * double-check this now that we have the actual
1572 * packet in hand.
1573 */
1574 struct ethhdr *ehdr;
1575 skb_reset_mac_header(skb);
1576 ehdr = eth_hdr(skb);
1577 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1578 err = -EMSGSIZE;
1579 goto out_unlock;
1580 }
1581 }
1582
1583 skb->protocol = proto;
1584 skb->dev = dev;
1585 skb->priority = sk->sk_priority;
1586 skb->mark = sk->sk_mark;
1587
1588 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1589
1590 if (unlikely(extra_len == 4))
1591 skb->no_fcs = 1;
1592
1593 skb_probe_transport_header(skb, 0);
1594
1595 dev_queue_xmit(skb);
1596 rcu_read_unlock();
1597 return len;
1598
1599 out_unlock:
1600 rcu_read_unlock();
1601 out_free:
1602 kfree_skb(skb);
1603 return err;
1604 }
1605
1606 static unsigned int run_filter(const struct sk_buff *skb,
1607 const struct sock *sk,
1608 unsigned int res)
1609 {
1610 struct sk_filter *filter;
1611
1612 rcu_read_lock();
1613 filter = rcu_dereference(sk->sk_filter);
1614 if (filter != NULL)
1615 res = SK_RUN_FILTER(filter, skb);
1616 rcu_read_unlock();
1617
1618 return res;
1619 }
1620
1621 /*
1622 * This function makes lazy skb cloning in hope that most of packets
1623 * are discarded by BPF.
1624 *
1625 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1626 * and skb->cb are mangled. It works because (and until) packets
1627 * falling here are owned by current CPU. Output packets are cloned
1628 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1629 * sequencially, so that if we return skb to original state on exit,
1630 * we will not harm anyone.
1631 */
1632
1633 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1634 struct packet_type *pt, struct net_device *orig_dev)
1635 {
1636 struct sock *sk;
1637 struct sockaddr_ll *sll;
1638 struct packet_sock *po;
1639 u8 *skb_head = skb->data;
1640 int skb_len = skb->len;
1641 unsigned int snaplen, res;
1642
1643 if (skb->pkt_type == PACKET_LOOPBACK)
1644 goto drop;
1645
1646 sk = pt->af_packet_priv;
1647 po = pkt_sk(sk);
1648
1649 if (!net_eq(dev_net(dev), sock_net(sk)))
1650 goto drop;
1651
1652 skb->dev = dev;
1653
1654 if (dev->header_ops) {
1655 /* The device has an explicit notion of ll header,
1656 * exported to higher levels.
1657 *
1658 * Otherwise, the device hides details of its frame
1659 * structure, so that corresponding packet head is
1660 * never delivered to user.
1661 */
1662 if (sk->sk_type != SOCK_DGRAM)
1663 skb_push(skb, skb->data - skb_mac_header(skb));
1664 else if (skb->pkt_type == PACKET_OUTGOING) {
1665 /* Special case: outgoing packets have ll header at head */
1666 skb_pull(skb, skb_network_offset(skb));
1667 }
1668 }
1669
1670 snaplen = skb->len;
1671
1672 res = run_filter(skb, sk, snaplen);
1673 if (!res)
1674 goto drop_n_restore;
1675 if (snaplen > res)
1676 snaplen = res;
1677
1678 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1679 goto drop_n_acct;
1680
1681 if (skb_shared(skb)) {
1682 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1683 if (nskb == NULL)
1684 goto drop_n_acct;
1685
1686 if (skb_head != skb->data) {
1687 skb->data = skb_head;
1688 skb->len = skb_len;
1689 }
1690 consume_skb(skb);
1691 skb = nskb;
1692 }
1693
1694 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1695 sizeof(skb->cb));
1696
1697 sll = &PACKET_SKB_CB(skb)->sa.ll;
1698 sll->sll_family = AF_PACKET;
1699 sll->sll_hatype = dev->type;
1700 sll->sll_protocol = skb->protocol;
1701 sll->sll_pkttype = skb->pkt_type;
1702 if (unlikely(po->origdev))
1703 sll->sll_ifindex = orig_dev->ifindex;
1704 else
1705 sll->sll_ifindex = dev->ifindex;
1706
1707 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1708
1709 PACKET_SKB_CB(skb)->origlen = skb->len;
1710
1711 if (pskb_trim(skb, snaplen))
1712 goto drop_n_acct;
1713
1714 skb_set_owner_r(skb, sk);
1715 skb->dev = NULL;
1716 skb_dst_drop(skb);
1717
1718 /* drop conntrack reference */
1719 nf_reset(skb);
1720
1721 spin_lock(&sk->sk_receive_queue.lock);
1722 po->stats.stats1.tp_packets++;
1723 skb->dropcount = atomic_read(&sk->sk_drops);
1724 __skb_queue_tail(&sk->sk_receive_queue, skb);
1725 spin_unlock(&sk->sk_receive_queue.lock);
1726 sk->sk_data_ready(sk, skb->len);
1727 return 0;
1728
1729 drop_n_acct:
1730 spin_lock(&sk->sk_receive_queue.lock);
1731 po->stats.stats1.tp_drops++;
1732 atomic_inc(&sk->sk_drops);
1733 spin_unlock(&sk->sk_receive_queue.lock);
1734
1735 drop_n_restore:
1736 if (skb_head != skb->data && skb_shared(skb)) {
1737 skb->data = skb_head;
1738 skb->len = skb_len;
1739 }
1740 drop:
1741 consume_skb(skb);
1742 return 0;
1743 }
1744
1745 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1746 struct packet_type *pt, struct net_device *orig_dev)
1747 {
1748 struct sock *sk;
1749 struct packet_sock *po;
1750 struct sockaddr_ll *sll;
1751 union tpacket_uhdr h;
1752 u8 *skb_head = skb->data;
1753 int skb_len = skb->len;
1754 unsigned int snaplen, res;
1755 unsigned long status = TP_STATUS_USER;
1756 unsigned short macoff, netoff, hdrlen;
1757 struct sk_buff *copy_skb = NULL;
1758 struct timespec ts;
1759 __u32 ts_status;
1760
1761 if (skb->pkt_type == PACKET_LOOPBACK)
1762 goto drop;
1763
1764 sk = pt->af_packet_priv;
1765 po = pkt_sk(sk);
1766
1767 if (!net_eq(dev_net(dev), sock_net(sk)))
1768 goto drop;
1769
1770 if (dev->header_ops) {
1771 if (sk->sk_type != SOCK_DGRAM)
1772 skb_push(skb, skb->data - skb_mac_header(skb));
1773 else if (skb->pkt_type == PACKET_OUTGOING) {
1774 /* Special case: outgoing packets have ll header at head */
1775 skb_pull(skb, skb_network_offset(skb));
1776 }
1777 }
1778
1779 if (skb->ip_summed == CHECKSUM_PARTIAL)
1780 status |= TP_STATUS_CSUMNOTREADY;
1781
1782 snaplen = skb->len;
1783
1784 res = run_filter(skb, sk, snaplen);
1785 if (!res)
1786 goto drop_n_restore;
1787 if (snaplen > res)
1788 snaplen = res;
1789
1790 if (sk->sk_type == SOCK_DGRAM) {
1791 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1792 po->tp_reserve;
1793 } else {
1794 unsigned int maclen = skb_network_offset(skb);
1795 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1796 (maclen < 16 ? 16 : maclen)) +
1797 po->tp_reserve;
1798 macoff = netoff - maclen;
1799 }
1800 if (po->tp_version <= TPACKET_V2) {
1801 if (macoff + snaplen > po->rx_ring.frame_size) {
1802 if (po->copy_thresh &&
1803 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1804 if (skb_shared(skb)) {
1805 copy_skb = skb_clone(skb, GFP_ATOMIC);
1806 } else {
1807 copy_skb = skb_get(skb);
1808 skb_head = skb->data;
1809 }
1810 if (copy_skb)
1811 skb_set_owner_r(copy_skb, sk);
1812 }
1813 snaplen = po->rx_ring.frame_size - macoff;
1814 if ((int)snaplen < 0)
1815 snaplen = 0;
1816 }
1817 }
1818 spin_lock(&sk->sk_receive_queue.lock);
1819 h.raw = packet_current_rx_frame(po, skb,
1820 TP_STATUS_KERNEL, (macoff+snaplen));
1821 if (!h.raw)
1822 goto ring_is_full;
1823 if (po->tp_version <= TPACKET_V2) {
1824 packet_increment_rx_head(po, &po->rx_ring);
1825 /*
1826 * LOSING will be reported till you read the stats,
1827 * because it's COR - Clear On Read.
1828 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1829 * at packet level.
1830 */
1831 if (po->stats.stats1.tp_drops)
1832 status |= TP_STATUS_LOSING;
1833 }
1834 po->stats.stats1.tp_packets++;
1835 if (copy_skb) {
1836 status |= TP_STATUS_COPY;
1837 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1838 }
1839 spin_unlock(&sk->sk_receive_queue.lock);
1840
1841 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1842
1843 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1844 getnstimeofday(&ts);
1845
1846 status |= ts_status;
1847
1848 switch (po->tp_version) {
1849 case TPACKET_V1:
1850 h.h1->tp_len = skb->len;
1851 h.h1->tp_snaplen = snaplen;
1852 h.h1->tp_mac = macoff;
1853 h.h1->tp_net = netoff;
1854 h.h1->tp_sec = ts.tv_sec;
1855 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1856 hdrlen = sizeof(*h.h1);
1857 break;
1858 case TPACKET_V2:
1859 h.h2->tp_len = skb->len;
1860 h.h2->tp_snaplen = snaplen;
1861 h.h2->tp_mac = macoff;
1862 h.h2->tp_net = netoff;
1863 h.h2->tp_sec = ts.tv_sec;
1864 h.h2->tp_nsec = ts.tv_nsec;
1865 if (vlan_tx_tag_present(skb)) {
1866 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1867 status |= TP_STATUS_VLAN_VALID;
1868 } else {
1869 h.h2->tp_vlan_tci = 0;
1870 }
1871 h.h2->tp_padding = 0;
1872 hdrlen = sizeof(*h.h2);
1873 break;
1874 case TPACKET_V3:
1875 /* tp_nxt_offset,vlan are already populated above.
1876 * So DONT clear those fields here
1877 */
1878 h.h3->tp_status |= status;
1879 h.h3->tp_len = skb->len;
1880 h.h3->tp_snaplen = snaplen;
1881 h.h3->tp_mac = macoff;
1882 h.h3->tp_net = netoff;
1883 h.h3->tp_sec = ts.tv_sec;
1884 h.h3->tp_nsec = ts.tv_nsec;
1885 hdrlen = sizeof(*h.h3);
1886 break;
1887 default:
1888 BUG();
1889 }
1890
1891 sll = h.raw + TPACKET_ALIGN(hdrlen);
1892 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1893 sll->sll_family = AF_PACKET;
1894 sll->sll_hatype = dev->type;
1895 sll->sll_protocol = skb->protocol;
1896 sll->sll_pkttype = skb->pkt_type;
1897 if (unlikely(po->origdev))
1898 sll->sll_ifindex = orig_dev->ifindex;
1899 else
1900 sll->sll_ifindex = dev->ifindex;
1901
1902 smp_mb();
1903 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1904 {
1905 u8 *start, *end;
1906
1907 if (po->tp_version <= TPACKET_V2) {
1908 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1909 + macoff + snaplen);
1910 for (start = h.raw; start < end; start += PAGE_SIZE)
1911 flush_dcache_page(pgv_to_page(start));
1912 }
1913 smp_wmb();
1914 }
1915 #endif
1916 if (po->tp_version <= TPACKET_V2)
1917 __packet_set_status(po, h.raw, status);
1918 else
1919 prb_clear_blk_fill_status(&po->rx_ring);
1920
1921 sk->sk_data_ready(sk, 0);
1922
1923 drop_n_restore:
1924 if (skb_head != skb->data && skb_shared(skb)) {
1925 skb->data = skb_head;
1926 skb->len = skb_len;
1927 }
1928 drop:
1929 kfree_skb(skb);
1930 return 0;
1931
1932 ring_is_full:
1933 po->stats.stats1.tp_drops++;
1934 spin_unlock(&sk->sk_receive_queue.lock);
1935
1936 sk->sk_data_ready(sk, 0);
1937 kfree_skb(copy_skb);
1938 goto drop_n_restore;
1939 }
1940
1941 static void tpacket_destruct_skb(struct sk_buff *skb)
1942 {
1943 struct packet_sock *po = pkt_sk(skb->sk);
1944 void *ph;
1945
1946 if (likely(po->tx_ring.pg_vec)) {
1947 __u32 ts;
1948
1949 ph = skb_shinfo(skb)->destructor_arg;
1950 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1951 atomic_dec(&po->tx_ring.pending);
1952
1953 ts = __packet_set_timestamp(po, ph, skb);
1954 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
1955 }
1956
1957 sock_wfree(skb);
1958 }
1959
1960 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1961 void *frame, struct net_device *dev, int size_max,
1962 __be16 proto, unsigned char *addr, int hlen)
1963 {
1964 union tpacket_uhdr ph;
1965 int to_write, offset, len, tp_len, nr_frags, len_max;
1966 struct socket *sock = po->sk.sk_socket;
1967 struct page *page;
1968 void *data;
1969 int err;
1970
1971 ph.raw = frame;
1972
1973 skb->protocol = proto;
1974 skb->dev = dev;
1975 skb->priority = po->sk.sk_priority;
1976 skb->mark = po->sk.sk_mark;
1977 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
1978 skb_shinfo(skb)->destructor_arg = ph.raw;
1979
1980 switch (po->tp_version) {
1981 case TPACKET_V2:
1982 tp_len = ph.h2->tp_len;
1983 break;
1984 default:
1985 tp_len = ph.h1->tp_len;
1986 break;
1987 }
1988 if (unlikely(tp_len > size_max)) {
1989 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1990 return -EMSGSIZE;
1991 }
1992
1993 skb_reserve(skb, hlen);
1994 skb_reset_network_header(skb);
1995 skb_probe_transport_header(skb, 0);
1996
1997 if (po->tp_tx_has_off) {
1998 int off_min, off_max, off;
1999 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2000 off_max = po->tx_ring.frame_size - tp_len;
2001 if (sock->type == SOCK_DGRAM) {
2002 switch (po->tp_version) {
2003 case TPACKET_V2:
2004 off = ph.h2->tp_net;
2005 break;
2006 default:
2007 off = ph.h1->tp_net;
2008 break;
2009 }
2010 } else {
2011 switch (po->tp_version) {
2012 case TPACKET_V2:
2013 off = ph.h2->tp_mac;
2014 break;
2015 default:
2016 off = ph.h1->tp_mac;
2017 break;
2018 }
2019 }
2020 if (unlikely((off < off_min) || (off_max < off)))
2021 return -EINVAL;
2022 data = ph.raw + off;
2023 } else {
2024 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2025 }
2026 to_write = tp_len;
2027
2028 if (sock->type == SOCK_DGRAM) {
2029 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2030 NULL, tp_len);
2031 if (unlikely(err < 0))
2032 return -EINVAL;
2033 } else if (dev->hard_header_len) {
2034 /* net device doesn't like empty head */
2035 if (unlikely(tp_len <= dev->hard_header_len)) {
2036 pr_err("packet size is too short (%d < %d)\n",
2037 tp_len, dev->hard_header_len);
2038 return -EINVAL;
2039 }
2040
2041 skb_push(skb, dev->hard_header_len);
2042 err = skb_store_bits(skb, 0, data,
2043 dev->hard_header_len);
2044 if (unlikely(err))
2045 return err;
2046
2047 data += dev->hard_header_len;
2048 to_write -= dev->hard_header_len;
2049 }
2050
2051 offset = offset_in_page(data);
2052 len_max = PAGE_SIZE - offset;
2053 len = ((to_write > len_max) ? len_max : to_write);
2054
2055 skb->data_len = to_write;
2056 skb->len += to_write;
2057 skb->truesize += to_write;
2058 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2059
2060 while (likely(to_write)) {
2061 nr_frags = skb_shinfo(skb)->nr_frags;
2062
2063 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2064 pr_err("Packet exceed the number of skb frags(%lu)\n",
2065 MAX_SKB_FRAGS);
2066 return -EFAULT;
2067 }
2068
2069 page = pgv_to_page(data);
2070 data += len;
2071 flush_dcache_page(page);
2072 get_page(page);
2073 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2074 to_write -= len;
2075 offset = 0;
2076 len_max = PAGE_SIZE;
2077 len = ((to_write > len_max) ? len_max : to_write);
2078 }
2079
2080 return tp_len;
2081 }
2082
2083 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2084 {
2085 struct sk_buff *skb;
2086 struct net_device *dev;
2087 __be16 proto;
2088 int err, reserve = 0;
2089 void *ph;
2090 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2091 int tp_len, size_max;
2092 unsigned char *addr;
2093 int len_sum = 0;
2094 int status = TP_STATUS_AVAILABLE;
2095 int hlen, tlen;
2096
2097 mutex_lock(&po->pg_vec_lock);
2098
2099 if (likely(saddr == NULL)) {
2100 dev = packet_cached_dev_get(po);
2101 proto = po->num;
2102 addr = NULL;
2103 } else {
2104 err = -EINVAL;
2105 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2106 goto out;
2107 if (msg->msg_namelen < (saddr->sll_halen
2108 + offsetof(struct sockaddr_ll,
2109 sll_addr)))
2110 goto out;
2111 proto = saddr->sll_protocol;
2112 addr = saddr->sll_addr;
2113 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2114 }
2115
2116 err = -ENXIO;
2117 if (unlikely(dev == NULL))
2118 goto out;
2119 err = -ENETDOWN;
2120 if (unlikely(!(dev->flags & IFF_UP)))
2121 goto out_put;
2122
2123 reserve = dev->hard_header_len;
2124
2125 size_max = po->tx_ring.frame_size
2126 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2127
2128 if (size_max > dev->mtu + reserve)
2129 size_max = dev->mtu + reserve;
2130
2131 do {
2132 ph = packet_current_frame(po, &po->tx_ring,
2133 TP_STATUS_SEND_REQUEST);
2134
2135 if (unlikely(ph == NULL)) {
2136 schedule();
2137 continue;
2138 }
2139
2140 status = TP_STATUS_SEND_REQUEST;
2141 hlen = LL_RESERVED_SPACE(dev);
2142 tlen = dev->needed_tailroom;
2143 skb = sock_alloc_send_skb(&po->sk,
2144 hlen + tlen + sizeof(struct sockaddr_ll),
2145 0, &err);
2146
2147 if (unlikely(skb == NULL))
2148 goto out_status;
2149
2150 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2151 addr, hlen);
2152
2153 if (unlikely(tp_len < 0)) {
2154 if (po->tp_loss) {
2155 __packet_set_status(po, ph,
2156 TP_STATUS_AVAILABLE);
2157 packet_increment_head(&po->tx_ring);
2158 kfree_skb(skb);
2159 continue;
2160 } else {
2161 status = TP_STATUS_WRONG_FORMAT;
2162 err = tp_len;
2163 goto out_status;
2164 }
2165 }
2166
2167 skb->destructor = tpacket_destruct_skb;
2168 __packet_set_status(po, ph, TP_STATUS_SENDING);
2169 atomic_inc(&po->tx_ring.pending);
2170
2171 status = TP_STATUS_SEND_REQUEST;
2172 err = dev_queue_xmit(skb);
2173 if (unlikely(err > 0)) {
2174 err = net_xmit_errno(err);
2175 if (err && __packet_get_status(po, ph) ==
2176 TP_STATUS_AVAILABLE) {
2177 /* skb was destructed already */
2178 skb = NULL;
2179 goto out_status;
2180 }
2181 /*
2182 * skb was dropped but not destructed yet;
2183 * let's treat it like congestion or err < 0
2184 */
2185 err = 0;
2186 }
2187 packet_increment_head(&po->tx_ring);
2188 len_sum += tp_len;
2189 } while (likely((ph != NULL) ||
2190 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2191 (atomic_read(&po->tx_ring.pending))))
2192 );
2193
2194 err = len_sum;
2195 goto out_put;
2196
2197 out_status:
2198 __packet_set_status(po, ph, status);
2199 kfree_skb(skb);
2200 out_put:
2201 dev_put(dev);
2202 out:
2203 mutex_unlock(&po->pg_vec_lock);
2204 return err;
2205 }
2206
2207 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2208 size_t reserve, size_t len,
2209 size_t linear, int noblock,
2210 int *err)
2211 {
2212 struct sk_buff *skb;
2213
2214 /* Under a page? Don't bother with paged skb. */
2215 if (prepad + len < PAGE_SIZE || !linear)
2216 linear = len;
2217
2218 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2219 err, 0);
2220 if (!skb)
2221 return NULL;
2222
2223 skb_reserve(skb, reserve);
2224 skb_put(skb, linear);
2225 skb->data_len = len - linear;
2226 skb->len += len - linear;
2227
2228 return skb;
2229 }
2230
2231 static int packet_snd(struct socket *sock,
2232 struct msghdr *msg, size_t len)
2233 {
2234 struct sock *sk = sock->sk;
2235 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2236 struct sk_buff *skb;
2237 struct net_device *dev;
2238 __be16 proto;
2239 unsigned char *addr;
2240 int err, reserve = 0;
2241 struct virtio_net_hdr vnet_hdr = { 0 };
2242 int offset = 0;
2243 int vnet_hdr_len;
2244 struct packet_sock *po = pkt_sk(sk);
2245 unsigned short gso_type = 0;
2246 int hlen, tlen;
2247 int extra_len = 0;
2248
2249 /*
2250 * Get and verify the address.
2251 */
2252
2253 if (likely(saddr == NULL)) {
2254 dev = packet_cached_dev_get(po);
2255 proto = po->num;
2256 addr = NULL;
2257 } else {
2258 err = -EINVAL;
2259 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2260 goto out;
2261 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2262 goto out;
2263 proto = saddr->sll_protocol;
2264 addr = saddr->sll_addr;
2265 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2266 }
2267
2268 err = -ENXIO;
2269 if (unlikely(dev == NULL))
2270 goto out_unlock;
2271 err = -ENETDOWN;
2272 if (unlikely(!(dev->flags & IFF_UP)))
2273 goto out_unlock;
2274
2275 if (sock->type == SOCK_RAW)
2276 reserve = dev->hard_header_len;
2277 if (po->has_vnet_hdr) {
2278 vnet_hdr_len = sizeof(vnet_hdr);
2279
2280 err = -EINVAL;
2281 if (len < vnet_hdr_len)
2282 goto out_unlock;
2283
2284 len -= vnet_hdr_len;
2285
2286 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2287 vnet_hdr_len);
2288 if (err < 0)
2289 goto out_unlock;
2290
2291 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2292 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2293 vnet_hdr.hdr_len))
2294 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2295 vnet_hdr.csum_offset + 2;
2296
2297 err = -EINVAL;
2298 if (vnet_hdr.hdr_len > len)
2299 goto out_unlock;
2300
2301 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2302 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2303 case VIRTIO_NET_HDR_GSO_TCPV4:
2304 gso_type = SKB_GSO_TCPV4;
2305 break;
2306 case VIRTIO_NET_HDR_GSO_TCPV6:
2307 gso_type = SKB_GSO_TCPV6;
2308 break;
2309 case VIRTIO_NET_HDR_GSO_UDP:
2310 gso_type = SKB_GSO_UDP;
2311 break;
2312 default:
2313 goto out_unlock;
2314 }
2315
2316 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2317 gso_type |= SKB_GSO_TCP_ECN;
2318
2319 if (vnet_hdr.gso_size == 0)
2320 goto out_unlock;
2321
2322 }
2323 }
2324
2325 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2326 if (!netif_supports_nofcs(dev)) {
2327 err = -EPROTONOSUPPORT;
2328 goto out_unlock;
2329 }
2330 extra_len = 4; /* We're doing our own CRC */
2331 }
2332
2333 err = -EMSGSIZE;
2334 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2335 goto out_unlock;
2336
2337 err = -ENOBUFS;
2338 hlen = LL_RESERVED_SPACE(dev);
2339 tlen = dev->needed_tailroom;
2340 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2341 msg->msg_flags & MSG_DONTWAIT, &err);
2342 if (skb == NULL)
2343 goto out_unlock;
2344
2345 skb_set_network_header(skb, reserve);
2346
2347 err = -EINVAL;
2348 if (sock->type == SOCK_DGRAM &&
2349 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2350 goto out_free;
2351
2352 /* Returns -EFAULT on error */
2353 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2354 if (err)
2355 goto out_free;
2356
2357 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2358
2359 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2360 /* Earlier code assumed this would be a VLAN pkt,
2361 * double-check this now that we have the actual
2362 * packet in hand.
2363 */
2364 struct ethhdr *ehdr;
2365 skb_reset_mac_header(skb);
2366 ehdr = eth_hdr(skb);
2367 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2368 err = -EMSGSIZE;
2369 goto out_free;
2370 }
2371 }
2372
2373 skb->protocol = proto;
2374 skb->dev = dev;
2375 skb->priority = sk->sk_priority;
2376 skb->mark = sk->sk_mark;
2377
2378 if (po->has_vnet_hdr) {
2379 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2380 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2381 vnet_hdr.csum_offset)) {
2382 err = -EINVAL;
2383 goto out_free;
2384 }
2385 }
2386
2387 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2388 skb_shinfo(skb)->gso_type = gso_type;
2389
2390 /* Header must be checked, and gso_segs computed. */
2391 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2392 skb_shinfo(skb)->gso_segs = 0;
2393
2394 len += vnet_hdr_len;
2395 }
2396
2397 skb_probe_transport_header(skb, reserve);
2398
2399 if (unlikely(extra_len == 4))
2400 skb->no_fcs = 1;
2401
2402 /*
2403 * Now send it
2404 */
2405
2406 err = dev_queue_xmit(skb);
2407 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2408 goto out_unlock;
2409
2410 dev_put(dev);
2411
2412 return len;
2413
2414 out_free:
2415 kfree_skb(skb);
2416 out_unlock:
2417 if (dev)
2418 dev_put(dev);
2419 out:
2420 return err;
2421 }
2422
2423 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2424 struct msghdr *msg, size_t len)
2425 {
2426 struct sock *sk = sock->sk;
2427 struct packet_sock *po = pkt_sk(sk);
2428 if (po->tx_ring.pg_vec)
2429 return tpacket_snd(po, msg);
2430 else
2431 return packet_snd(sock, msg, len);
2432 }
2433
2434 /*
2435 * Close a PACKET socket. This is fairly simple. We immediately go
2436 * to 'closed' state and remove our protocol entry in the device list.
2437 */
2438
2439 static int packet_release(struct socket *sock)
2440 {
2441 struct sock *sk = sock->sk;
2442 struct packet_sock *po;
2443 struct net *net;
2444 union tpacket_req_u req_u;
2445
2446 if (!sk)
2447 return 0;
2448
2449 net = sock_net(sk);
2450 po = pkt_sk(sk);
2451
2452 mutex_lock(&net->packet.sklist_lock);
2453 sk_del_node_init_rcu(sk);
2454 mutex_unlock(&net->packet.sklist_lock);
2455
2456 preempt_disable();
2457 sock_prot_inuse_add(net, sk->sk_prot, -1);
2458 preempt_enable();
2459
2460 spin_lock(&po->bind_lock);
2461 unregister_prot_hook(sk, false);
2462 packet_cached_dev_reset(po);
2463
2464 if (po->prot_hook.dev) {
2465 dev_put(po->prot_hook.dev);
2466 po->prot_hook.dev = NULL;
2467 }
2468 spin_unlock(&po->bind_lock);
2469
2470 packet_flush_mclist(sk);
2471
2472 if (po->rx_ring.pg_vec) {
2473 memset(&req_u, 0, sizeof(req_u));
2474 packet_set_ring(sk, &req_u, 1, 0);
2475 }
2476
2477 if (po->tx_ring.pg_vec) {
2478 memset(&req_u, 0, sizeof(req_u));
2479 packet_set_ring(sk, &req_u, 1, 1);
2480 }
2481
2482 fanout_release(sk);
2483
2484 synchronize_net();
2485 /*
2486 * Now the socket is dead. No more input will appear.
2487 */
2488 sock_orphan(sk);
2489 sock->sk = NULL;
2490
2491 /* Purge queues */
2492
2493 skb_queue_purge(&sk->sk_receive_queue);
2494 sk_refcnt_debug_release(sk);
2495
2496 sock_put(sk);
2497 return 0;
2498 }
2499
2500 /*
2501 * Attach a packet hook.
2502 */
2503
2504 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2505 {
2506 struct packet_sock *po = pkt_sk(sk);
2507
2508 if (po->fanout) {
2509 if (dev)
2510 dev_put(dev);
2511
2512 return -EINVAL;
2513 }
2514
2515 lock_sock(sk);
2516
2517 spin_lock(&po->bind_lock);
2518 unregister_prot_hook(sk, true);
2519
2520 po->num = protocol;
2521 po->prot_hook.type = protocol;
2522 if (po->prot_hook.dev)
2523 dev_put(po->prot_hook.dev);
2524
2525 po->prot_hook.dev = dev;
2526 po->ifindex = dev ? dev->ifindex : 0;
2527
2528 packet_cached_dev_assign(po, dev);
2529
2530 if (protocol == 0)
2531 goto out_unlock;
2532
2533 if (!dev || (dev->flags & IFF_UP)) {
2534 register_prot_hook(sk);
2535 } else {
2536 sk->sk_err = ENETDOWN;
2537 if (!sock_flag(sk, SOCK_DEAD))
2538 sk->sk_error_report(sk);
2539 }
2540
2541 out_unlock:
2542 spin_unlock(&po->bind_lock);
2543 release_sock(sk);
2544 return 0;
2545 }
2546
2547 /*
2548 * Bind a packet socket to a device
2549 */
2550
2551 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2552 int addr_len)
2553 {
2554 struct sock *sk = sock->sk;
2555 char name[15];
2556 struct net_device *dev;
2557 int err = -ENODEV;
2558
2559 /*
2560 * Check legality
2561 */
2562
2563 if (addr_len != sizeof(struct sockaddr))
2564 return -EINVAL;
2565 strlcpy(name, uaddr->sa_data, sizeof(name));
2566
2567 dev = dev_get_by_name(sock_net(sk), name);
2568 if (dev)
2569 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2570 return err;
2571 }
2572
2573 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2574 {
2575 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2576 struct sock *sk = sock->sk;
2577 struct net_device *dev = NULL;
2578 int err;
2579
2580
2581 /*
2582 * Check legality
2583 */
2584
2585 if (addr_len < sizeof(struct sockaddr_ll))
2586 return -EINVAL;
2587 if (sll->sll_family != AF_PACKET)
2588 return -EINVAL;
2589
2590 if (sll->sll_ifindex) {
2591 err = -ENODEV;
2592 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2593 if (dev == NULL)
2594 goto out;
2595 }
2596 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2597
2598 out:
2599 return err;
2600 }
2601
2602 static struct proto packet_proto = {
2603 .name = "PACKET",
2604 .owner = THIS_MODULE,
2605 .obj_size = sizeof(struct packet_sock),
2606 };
2607
2608 /*
2609 * Create a packet of type SOCK_PACKET.
2610 */
2611
2612 static int packet_create(struct net *net, struct socket *sock, int protocol,
2613 int kern)
2614 {
2615 struct sock *sk;
2616 struct packet_sock *po;
2617 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2618 int err;
2619
2620 if (!ns_capable(net->user_ns, CAP_NET_RAW))
2621 return -EPERM;
2622 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2623 sock->type != SOCK_PACKET)
2624 return -ESOCKTNOSUPPORT;
2625
2626 sock->state = SS_UNCONNECTED;
2627
2628 err = -ENOBUFS;
2629 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2630 if (sk == NULL)
2631 goto out;
2632
2633 sock->ops = &packet_ops;
2634 if (sock->type == SOCK_PACKET)
2635 sock->ops = &packet_ops_spkt;
2636
2637 sock_init_data(sock, sk);
2638
2639 po = pkt_sk(sk);
2640 sk->sk_family = PF_PACKET;
2641 po->num = proto;
2642
2643 packet_cached_dev_reset(po);
2644
2645 sk->sk_destruct = packet_sock_destruct;
2646 sk_refcnt_debug_inc(sk);
2647
2648 /*
2649 * Attach a protocol block
2650 */
2651
2652 spin_lock_init(&po->bind_lock);
2653 mutex_init(&po->pg_vec_lock);
2654 po->prot_hook.func = packet_rcv;
2655
2656 if (sock->type == SOCK_PACKET)
2657 po->prot_hook.func = packet_rcv_spkt;
2658
2659 po->prot_hook.af_packet_priv = sk;
2660
2661 if (proto) {
2662 po->prot_hook.type = proto;
2663 register_prot_hook(sk);
2664 }
2665
2666 mutex_lock(&net->packet.sklist_lock);
2667 sk_add_node_rcu(sk, &net->packet.sklist);
2668 mutex_unlock(&net->packet.sklist_lock);
2669
2670 preempt_disable();
2671 sock_prot_inuse_add(net, &packet_proto, 1);
2672 preempt_enable();
2673
2674 return 0;
2675 out:
2676 return err;
2677 }
2678
2679 /*
2680 * Pull a packet from our receive queue and hand it to the user.
2681 * If necessary we block.
2682 */
2683
2684 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2685 struct msghdr *msg, size_t len, int flags)
2686 {
2687 struct sock *sk = sock->sk;
2688 struct sk_buff *skb;
2689 int copied, err;
2690 int vnet_hdr_len = 0;
2691
2692 err = -EINVAL;
2693 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2694 goto out;
2695
2696 #if 0
2697 /* What error should we return now? EUNATTACH? */
2698 if (pkt_sk(sk)->ifindex < 0)
2699 return -ENODEV;
2700 #endif
2701
2702 if (flags & MSG_ERRQUEUE) {
2703 err = sock_recv_errqueue(sk, msg, len,
2704 SOL_PACKET, PACKET_TX_TIMESTAMP);
2705 goto out;
2706 }
2707
2708 /*
2709 * Call the generic datagram receiver. This handles all sorts
2710 * of horrible races and re-entrancy so we can forget about it
2711 * in the protocol layers.
2712 *
2713 * Now it will return ENETDOWN, if device have just gone down,
2714 * but then it will block.
2715 */
2716
2717 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2718
2719 /*
2720 * An error occurred so return it. Because skb_recv_datagram()
2721 * handles the blocking we don't see and worry about blocking
2722 * retries.
2723 */
2724
2725 if (skb == NULL)
2726 goto out;
2727
2728 if (pkt_sk(sk)->has_vnet_hdr) {
2729 struct virtio_net_hdr vnet_hdr = { 0 };
2730
2731 err = -EINVAL;
2732 vnet_hdr_len = sizeof(vnet_hdr);
2733 if (len < vnet_hdr_len)
2734 goto out_free;
2735
2736 len -= vnet_hdr_len;
2737
2738 if (skb_is_gso(skb)) {
2739 struct skb_shared_info *sinfo = skb_shinfo(skb);
2740
2741 /* This is a hint as to how much should be linear. */
2742 vnet_hdr.hdr_len = skb_headlen(skb);
2743 vnet_hdr.gso_size = sinfo->gso_size;
2744 if (sinfo->gso_type & SKB_GSO_TCPV4)
2745 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2746 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2747 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2748 else if (sinfo->gso_type & SKB_GSO_UDP)
2749 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2750 else if (sinfo->gso_type & SKB_GSO_FCOE)
2751 goto out_free;
2752 else
2753 BUG();
2754 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2755 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2756 } else
2757 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2758
2759 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2760 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2761 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2762 vnet_hdr.csum_offset = skb->csum_offset;
2763 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2764 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2765 } /* else everything is zero */
2766
2767 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2768 vnet_hdr_len);
2769 if (err < 0)
2770 goto out_free;
2771 }
2772
2773 /* You lose any data beyond the buffer you gave. If it worries
2774 * a user program they can ask the device for its MTU
2775 * anyway.
2776 */
2777 copied = skb->len;
2778 if (copied > len) {
2779 copied = len;
2780 msg->msg_flags |= MSG_TRUNC;
2781 }
2782
2783 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2784 if (err)
2785 goto out_free;
2786
2787 sock_recv_ts_and_drops(msg, sk, skb);
2788
2789 if (msg->msg_name) {
2790 /* If the address length field is there to be filled
2791 * in, we fill it in now.
2792 */
2793 if (sock->type == SOCK_PACKET) {
2794 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2795 } else {
2796 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
2797 msg->msg_namelen = sll->sll_halen +
2798 offsetof(struct sockaddr_ll, sll_addr);
2799 }
2800 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2801 msg->msg_namelen);
2802 }
2803
2804 if (pkt_sk(sk)->auxdata) {
2805 struct tpacket_auxdata aux;
2806
2807 aux.tp_status = TP_STATUS_USER;
2808 if (skb->ip_summed == CHECKSUM_PARTIAL)
2809 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2810 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2811 aux.tp_snaplen = skb->len;
2812 aux.tp_mac = 0;
2813 aux.tp_net = skb_network_offset(skb);
2814 if (vlan_tx_tag_present(skb)) {
2815 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2816 aux.tp_status |= TP_STATUS_VLAN_VALID;
2817 } else {
2818 aux.tp_vlan_tci = 0;
2819 }
2820 aux.tp_padding = 0;
2821 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2822 }
2823
2824 /*
2825 * Free or return the buffer as appropriate. Again this
2826 * hides all the races and re-entrancy issues from us.
2827 */
2828 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2829
2830 out_free:
2831 skb_free_datagram(sk, skb);
2832 out:
2833 return err;
2834 }
2835
2836 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2837 int *uaddr_len, int peer)
2838 {
2839 struct net_device *dev;
2840 struct sock *sk = sock->sk;
2841
2842 if (peer)
2843 return -EOPNOTSUPP;
2844
2845 uaddr->sa_family = AF_PACKET;
2846 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
2847 rcu_read_lock();
2848 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2849 if (dev)
2850 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
2851 rcu_read_unlock();
2852 *uaddr_len = sizeof(*uaddr);
2853
2854 return 0;
2855 }
2856
2857 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2858 int *uaddr_len, int peer)
2859 {
2860 struct net_device *dev;
2861 struct sock *sk = sock->sk;
2862 struct packet_sock *po = pkt_sk(sk);
2863 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2864
2865 if (peer)
2866 return -EOPNOTSUPP;
2867
2868 sll->sll_family = AF_PACKET;
2869 sll->sll_ifindex = po->ifindex;
2870 sll->sll_protocol = po->num;
2871 sll->sll_pkttype = 0;
2872 rcu_read_lock();
2873 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2874 if (dev) {
2875 sll->sll_hatype = dev->type;
2876 sll->sll_halen = dev->addr_len;
2877 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2878 } else {
2879 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2880 sll->sll_halen = 0;
2881 }
2882 rcu_read_unlock();
2883 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2884
2885 return 0;
2886 }
2887
2888 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2889 int what)
2890 {
2891 switch (i->type) {
2892 case PACKET_MR_MULTICAST:
2893 if (i->alen != dev->addr_len)
2894 return -EINVAL;
2895 if (what > 0)
2896 return dev_mc_add(dev, i->addr);
2897 else
2898 return dev_mc_del(dev, i->addr);
2899 break;
2900 case PACKET_MR_PROMISC:
2901 return dev_set_promiscuity(dev, what);
2902 break;
2903 case PACKET_MR_ALLMULTI:
2904 return dev_set_allmulti(dev, what);
2905 break;
2906 case PACKET_MR_UNICAST:
2907 if (i->alen != dev->addr_len)
2908 return -EINVAL;
2909 if (what > 0)
2910 return dev_uc_add(dev, i->addr);
2911 else
2912 return dev_uc_del(dev, i->addr);
2913 break;
2914 default:
2915 break;
2916 }
2917 return 0;
2918 }
2919
2920 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2921 {
2922 for ( ; i; i = i->next) {
2923 if (i->ifindex == dev->ifindex)
2924 packet_dev_mc(dev, i, what);
2925 }
2926 }
2927
2928 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2929 {
2930 struct packet_sock *po = pkt_sk(sk);
2931 struct packet_mclist *ml, *i;
2932 struct net_device *dev;
2933 int err;
2934
2935 rtnl_lock();
2936
2937 err = -ENODEV;
2938 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2939 if (!dev)
2940 goto done;
2941
2942 err = -EINVAL;
2943 if (mreq->mr_alen > dev->addr_len)
2944 goto done;
2945
2946 err = -ENOBUFS;
2947 i = kmalloc(sizeof(*i), GFP_KERNEL);
2948 if (i == NULL)
2949 goto done;
2950
2951 err = 0;
2952 for (ml = po->mclist; ml; ml = ml->next) {
2953 if (ml->ifindex == mreq->mr_ifindex &&
2954 ml->type == mreq->mr_type &&
2955 ml->alen == mreq->mr_alen &&
2956 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2957 ml->count++;
2958 /* Free the new element ... */
2959 kfree(i);
2960 goto done;
2961 }
2962 }
2963
2964 i->type = mreq->mr_type;
2965 i->ifindex = mreq->mr_ifindex;
2966 i->alen = mreq->mr_alen;
2967 memcpy(i->addr, mreq->mr_address, i->alen);
2968 i->count = 1;
2969 i->next = po->mclist;
2970 po->mclist = i;
2971 err = packet_dev_mc(dev, i, 1);
2972 if (err) {
2973 po->mclist = i->next;
2974 kfree(i);
2975 }
2976
2977 done:
2978 rtnl_unlock();
2979 return err;
2980 }
2981
2982 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2983 {
2984 struct packet_mclist *ml, **mlp;
2985
2986 rtnl_lock();
2987
2988 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2989 if (ml->ifindex == mreq->mr_ifindex &&
2990 ml->type == mreq->mr_type &&
2991 ml->alen == mreq->mr_alen &&
2992 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2993 if (--ml->count == 0) {
2994 struct net_device *dev;
2995 *mlp = ml->next;
2996 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2997 if (dev)
2998 packet_dev_mc(dev, ml, -1);
2999 kfree(ml);
3000 }
3001 rtnl_unlock();
3002 return 0;
3003 }
3004 }
3005 rtnl_unlock();
3006 return -EADDRNOTAVAIL;
3007 }
3008
3009 static void packet_flush_mclist(struct sock *sk)
3010 {
3011 struct packet_sock *po = pkt_sk(sk);
3012 struct packet_mclist *ml;
3013
3014 if (!po->mclist)
3015 return;
3016
3017 rtnl_lock();
3018 while ((ml = po->mclist) != NULL) {
3019 struct net_device *dev;
3020
3021 po->mclist = ml->next;
3022 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3023 if (dev != NULL)
3024 packet_dev_mc(dev, ml, -1);
3025 kfree(ml);
3026 }
3027 rtnl_unlock();
3028 }
3029
3030 static int
3031 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3032 {
3033 struct sock *sk = sock->sk;
3034 struct packet_sock *po = pkt_sk(sk);
3035 int ret;
3036
3037 if (level != SOL_PACKET)
3038 return -ENOPROTOOPT;
3039
3040 switch (optname) {
3041 case PACKET_ADD_MEMBERSHIP:
3042 case PACKET_DROP_MEMBERSHIP:
3043 {
3044 struct packet_mreq_max mreq;
3045 int len = optlen;
3046 memset(&mreq, 0, sizeof(mreq));
3047 if (len < sizeof(struct packet_mreq))
3048 return -EINVAL;
3049 if (len > sizeof(mreq))
3050 len = sizeof(mreq);
3051 if (copy_from_user(&mreq, optval, len))
3052 return -EFAULT;
3053 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3054 return -EINVAL;
3055 if (optname == PACKET_ADD_MEMBERSHIP)
3056 ret = packet_mc_add(sk, &mreq);
3057 else
3058 ret = packet_mc_drop(sk, &mreq);
3059 return ret;
3060 }
3061
3062 case PACKET_RX_RING:
3063 case PACKET_TX_RING:
3064 {
3065 union tpacket_req_u req_u;
3066 int len;
3067
3068 switch (po->tp_version) {
3069 case TPACKET_V1:
3070 case TPACKET_V2:
3071 len = sizeof(req_u.req);
3072 break;
3073 case TPACKET_V3:
3074 default:
3075 len = sizeof(req_u.req3);
3076 break;
3077 }
3078 if (optlen < len)
3079 return -EINVAL;
3080 if (pkt_sk(sk)->has_vnet_hdr)
3081 return -EINVAL;
3082 if (copy_from_user(&req_u.req, optval, len))
3083 return -EFAULT;
3084 return packet_set_ring(sk, &req_u, 0,
3085 optname == PACKET_TX_RING);
3086 }
3087 case PACKET_COPY_THRESH:
3088 {
3089 int val;
3090
3091 if (optlen != sizeof(val))
3092 return -EINVAL;
3093 if (copy_from_user(&val, optval, sizeof(val)))
3094 return -EFAULT;
3095
3096 pkt_sk(sk)->copy_thresh = val;
3097 return 0;
3098 }
3099 case PACKET_VERSION:
3100 {
3101 int val;
3102
3103 if (optlen != sizeof(val))
3104 return -EINVAL;
3105 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3106 return -EBUSY;
3107 if (copy_from_user(&val, optval, sizeof(val)))
3108 return -EFAULT;
3109 switch (val) {
3110 case TPACKET_V1:
3111 case TPACKET_V2:
3112 case TPACKET_V3:
3113 po->tp_version = val;
3114 return 0;
3115 default:
3116 return -EINVAL;
3117 }
3118 }
3119 case PACKET_RESERVE:
3120 {
3121 unsigned int val;
3122
3123 if (optlen != sizeof(val))
3124 return -EINVAL;
3125 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3126 return -EBUSY;
3127 if (copy_from_user(&val, optval, sizeof(val)))
3128 return -EFAULT;
3129 po->tp_reserve = val;
3130 return 0;
3131 }
3132 case PACKET_LOSS:
3133 {
3134 unsigned int val;
3135
3136 if (optlen != sizeof(val))
3137 return -EINVAL;
3138 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3139 return -EBUSY;
3140 if (copy_from_user(&val, optval, sizeof(val)))
3141 return -EFAULT;
3142 po->tp_loss = !!val;
3143 return 0;
3144 }
3145 case PACKET_AUXDATA:
3146 {
3147 int val;
3148
3149 if (optlen < sizeof(val))
3150 return -EINVAL;
3151 if (copy_from_user(&val, optval, sizeof(val)))
3152 return -EFAULT;
3153
3154 po->auxdata = !!val;
3155 return 0;
3156 }
3157 case PACKET_ORIGDEV:
3158 {
3159 int val;
3160
3161 if (optlen < sizeof(val))
3162 return -EINVAL;
3163 if (copy_from_user(&val, optval, sizeof(val)))
3164 return -EFAULT;
3165
3166 po->origdev = !!val;
3167 return 0;
3168 }
3169 case PACKET_VNET_HDR:
3170 {
3171 int val;
3172
3173 if (sock->type != SOCK_RAW)
3174 return -EINVAL;
3175 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3176 return -EBUSY;
3177 if (optlen < sizeof(val))
3178 return -EINVAL;
3179 if (copy_from_user(&val, optval, sizeof(val)))
3180 return -EFAULT;
3181
3182 po->has_vnet_hdr = !!val;
3183 return 0;
3184 }
3185 case PACKET_TIMESTAMP:
3186 {
3187 int val;
3188
3189 if (optlen != sizeof(val))
3190 return -EINVAL;
3191 if (copy_from_user(&val, optval, sizeof(val)))
3192 return -EFAULT;
3193
3194 po->tp_tstamp = val;
3195 return 0;
3196 }
3197 case PACKET_FANOUT:
3198 {
3199 int val;
3200
3201 if (optlen != sizeof(val))
3202 return -EINVAL;
3203 if (copy_from_user(&val, optval, sizeof(val)))
3204 return -EFAULT;
3205
3206 return fanout_add(sk, val & 0xffff, val >> 16);
3207 }
3208 case PACKET_TX_HAS_OFF:
3209 {
3210 unsigned int val;
3211
3212 if (optlen != sizeof(val))
3213 return -EINVAL;
3214 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3215 return -EBUSY;
3216 if (copy_from_user(&val, optval, sizeof(val)))
3217 return -EFAULT;
3218 po->tp_tx_has_off = !!val;
3219 return 0;
3220 }
3221 default:
3222 return -ENOPROTOOPT;
3223 }
3224 }
3225
3226 static int packet_getsockopt(struct socket *sock, int level, int optname,
3227 char __user *optval, int __user *optlen)
3228 {
3229 int len;
3230 int val, lv = sizeof(val);
3231 struct sock *sk = sock->sk;
3232 struct packet_sock *po = pkt_sk(sk);
3233 void *data = &val;
3234 union tpacket_stats_u st;
3235
3236 if (level != SOL_PACKET)
3237 return -ENOPROTOOPT;
3238
3239 if (get_user(len, optlen))
3240 return -EFAULT;
3241
3242 if (len < 0)
3243 return -EINVAL;
3244
3245 switch (optname) {
3246 case PACKET_STATISTICS:
3247 spin_lock_bh(&sk->sk_receive_queue.lock);
3248 memcpy(&st, &po->stats, sizeof(st));
3249 memset(&po->stats, 0, sizeof(po->stats));
3250 spin_unlock_bh(&sk->sk_receive_queue.lock);
3251
3252 if (po->tp_version == TPACKET_V3) {
3253 lv = sizeof(struct tpacket_stats_v3);
3254 st.stats3.tp_packets += st.stats3.tp_drops;
3255 data = &st.stats3;
3256 } else {
3257 lv = sizeof(struct tpacket_stats);
3258 st.stats1.tp_packets += st.stats1.tp_drops;
3259 data = &st.stats1;
3260 }
3261
3262 break;
3263 case PACKET_AUXDATA:
3264 val = po->auxdata;
3265 break;
3266 case PACKET_ORIGDEV:
3267 val = po->origdev;
3268 break;
3269 case PACKET_VNET_HDR:
3270 val = po->has_vnet_hdr;
3271 break;
3272 case PACKET_VERSION:
3273 val = po->tp_version;
3274 break;
3275 case PACKET_HDRLEN:
3276 if (len > sizeof(int))
3277 len = sizeof(int);
3278 if (copy_from_user(&val, optval, len))
3279 return -EFAULT;
3280 switch (val) {
3281 case TPACKET_V1:
3282 val = sizeof(struct tpacket_hdr);
3283 break;
3284 case TPACKET_V2:
3285 val = sizeof(struct tpacket2_hdr);
3286 break;
3287 case TPACKET_V3:
3288 val = sizeof(struct tpacket3_hdr);
3289 break;
3290 default:
3291 return -EINVAL;
3292 }
3293 break;
3294 case PACKET_RESERVE:
3295 val = po->tp_reserve;
3296 break;
3297 case PACKET_LOSS:
3298 val = po->tp_loss;
3299 break;
3300 case PACKET_TIMESTAMP:
3301 val = po->tp_tstamp;
3302 break;
3303 case PACKET_FANOUT:
3304 val = (po->fanout ?
3305 ((u32)po->fanout->id |
3306 ((u32)po->fanout->type << 16) |
3307 ((u32)po->fanout->flags << 24)) :
3308 0);
3309 break;
3310 case PACKET_TX_HAS_OFF:
3311 val = po->tp_tx_has_off;
3312 break;
3313 default:
3314 return -ENOPROTOOPT;
3315 }
3316
3317 if (len > lv)
3318 len = lv;
3319 if (put_user(len, optlen))
3320 return -EFAULT;
3321 if (copy_to_user(optval, data, len))
3322 return -EFAULT;
3323 return 0;
3324 }
3325
3326
3327 static int packet_notifier(struct notifier_block *this,
3328 unsigned long msg, void *ptr)
3329 {
3330 struct sock *sk;
3331 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3332 struct net *net = dev_net(dev);
3333
3334 rcu_read_lock();
3335 sk_for_each_rcu(sk, &net->packet.sklist) {
3336 struct packet_sock *po = pkt_sk(sk);
3337
3338 switch (msg) {
3339 case NETDEV_UNREGISTER:
3340 if (po->mclist)
3341 packet_dev_mclist(dev, po->mclist, -1);
3342 /* fallthrough */
3343
3344 case NETDEV_DOWN:
3345 if (dev->ifindex == po->ifindex) {
3346 spin_lock(&po->bind_lock);
3347 if (po->running) {
3348 __unregister_prot_hook(sk, false);
3349 sk->sk_err = ENETDOWN;
3350 if (!sock_flag(sk, SOCK_DEAD))
3351 sk->sk_error_report(sk);
3352 }
3353 if (msg == NETDEV_UNREGISTER) {
3354 packet_cached_dev_reset(po);
3355 po->ifindex = -1;
3356 if (po->prot_hook.dev)
3357 dev_put(po->prot_hook.dev);
3358 po->prot_hook.dev = NULL;
3359 }
3360 spin_unlock(&po->bind_lock);
3361 }
3362 break;
3363 case NETDEV_UP:
3364 if (dev->ifindex == po->ifindex) {
3365 spin_lock(&po->bind_lock);
3366 if (po->num)
3367 register_prot_hook(sk);
3368 spin_unlock(&po->bind_lock);
3369 }
3370 break;
3371 }
3372 }
3373 rcu_read_unlock();
3374 return NOTIFY_DONE;
3375 }
3376
3377
3378 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3379 unsigned long arg)
3380 {
3381 struct sock *sk = sock->sk;
3382
3383 switch (cmd) {
3384 case SIOCOUTQ:
3385 {
3386 int amount = sk_wmem_alloc_get(sk);
3387
3388 return put_user(amount, (int __user *)arg);
3389 }
3390 case SIOCINQ:
3391 {
3392 struct sk_buff *skb;
3393 int amount = 0;
3394
3395 spin_lock_bh(&sk->sk_receive_queue.lock);
3396 skb = skb_peek(&sk->sk_receive_queue);
3397 if (skb)
3398 amount = skb->len;
3399 spin_unlock_bh(&sk->sk_receive_queue.lock);
3400 return put_user(amount, (int __user *)arg);
3401 }
3402 case SIOCGSTAMP:
3403 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3404 case SIOCGSTAMPNS:
3405 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3406
3407 #ifdef CONFIG_INET
3408 case SIOCADDRT:
3409 case SIOCDELRT:
3410 case SIOCDARP:
3411 case SIOCGARP:
3412 case SIOCSARP:
3413 case SIOCGIFADDR:
3414 case SIOCSIFADDR:
3415 case SIOCGIFBRDADDR:
3416 case SIOCSIFBRDADDR:
3417 case SIOCGIFNETMASK:
3418 case SIOCSIFNETMASK:
3419 case SIOCGIFDSTADDR:
3420 case SIOCSIFDSTADDR:
3421 case SIOCSIFFLAGS:
3422 return inet_dgram_ops.ioctl(sock, cmd, arg);
3423 #endif
3424
3425 default:
3426 return -ENOIOCTLCMD;
3427 }
3428 return 0;
3429 }
3430
3431 static unsigned int packet_poll(struct file *file, struct socket *sock,
3432 poll_table *wait)
3433 {
3434 struct sock *sk = sock->sk;
3435 struct packet_sock *po = pkt_sk(sk);
3436 unsigned int mask = datagram_poll(file, sock, wait);
3437
3438 spin_lock_bh(&sk->sk_receive_queue.lock);
3439 if (po->rx_ring.pg_vec) {
3440 if (!packet_previous_rx_frame(po, &po->rx_ring,
3441 TP_STATUS_KERNEL))
3442 mask |= POLLIN | POLLRDNORM;
3443 }
3444 spin_unlock_bh(&sk->sk_receive_queue.lock);
3445 spin_lock_bh(&sk->sk_write_queue.lock);
3446 if (po->tx_ring.pg_vec) {
3447 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3448 mask |= POLLOUT | POLLWRNORM;
3449 }
3450 spin_unlock_bh(&sk->sk_write_queue.lock);
3451 return mask;
3452 }
3453
3454
3455 /* Dirty? Well, I still did not learn better way to account
3456 * for user mmaps.
3457 */
3458
3459 static void packet_mm_open(struct vm_area_struct *vma)
3460 {
3461 struct file *file = vma->vm_file;
3462 struct socket *sock = file->private_data;
3463 struct sock *sk = sock->sk;
3464
3465 if (sk)
3466 atomic_inc(&pkt_sk(sk)->mapped);
3467 }
3468
3469 static void packet_mm_close(struct vm_area_struct *vma)
3470 {
3471 struct file *file = vma->vm_file;
3472 struct socket *sock = file->private_data;
3473 struct sock *sk = sock->sk;
3474
3475 if (sk)
3476 atomic_dec(&pkt_sk(sk)->mapped);
3477 }
3478
3479 static const struct vm_operations_struct packet_mmap_ops = {
3480 .open = packet_mm_open,
3481 .close = packet_mm_close,
3482 };
3483
3484 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3485 unsigned int len)
3486 {
3487 int i;
3488
3489 for (i = 0; i < len; i++) {
3490 if (likely(pg_vec[i].buffer)) {
3491 if (is_vmalloc_addr(pg_vec[i].buffer))
3492 vfree(pg_vec[i].buffer);
3493 else
3494 free_pages((unsigned long)pg_vec[i].buffer,
3495 order);
3496 pg_vec[i].buffer = NULL;
3497 }
3498 }
3499 kfree(pg_vec);
3500 }
3501
3502 static char *alloc_one_pg_vec_page(unsigned long order)
3503 {
3504 char *buffer = NULL;
3505 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3506 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3507
3508 buffer = (char *) __get_free_pages(gfp_flags, order);
3509
3510 if (buffer)
3511 return buffer;
3512
3513 /*
3514 * __get_free_pages failed, fall back to vmalloc
3515 */
3516 buffer = vzalloc((1 << order) * PAGE_SIZE);
3517
3518 if (buffer)
3519 return buffer;
3520
3521 /*
3522 * vmalloc failed, lets dig into swap here
3523 */
3524 gfp_flags &= ~__GFP_NORETRY;
3525 buffer = (char *)__get_free_pages(gfp_flags, order);
3526 if (buffer)
3527 return buffer;
3528
3529 /*
3530 * complete and utter failure
3531 */
3532 return NULL;
3533 }
3534
3535 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3536 {
3537 unsigned int block_nr = req->tp_block_nr;
3538 struct pgv *pg_vec;
3539 int i;
3540
3541 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3542 if (unlikely(!pg_vec))
3543 goto out;
3544
3545 for (i = 0; i < block_nr; i++) {
3546 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3547 if (unlikely(!pg_vec[i].buffer))
3548 goto out_free_pgvec;
3549 }
3550
3551 out:
3552 return pg_vec;
3553
3554 out_free_pgvec:
3555 free_pg_vec(pg_vec, order, block_nr);
3556 pg_vec = NULL;
3557 goto out;
3558 }
3559
3560 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3561 int closing, int tx_ring)
3562 {
3563 struct pgv *pg_vec = NULL;
3564 struct packet_sock *po = pkt_sk(sk);
3565 int was_running, order = 0;
3566 struct packet_ring_buffer *rb;
3567 struct sk_buff_head *rb_queue;
3568 __be16 num;
3569 int err = -EINVAL;
3570 /* Added to avoid minimal code churn */
3571 struct tpacket_req *req = &req_u->req;
3572
3573 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3574 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3575 WARN(1, "Tx-ring is not supported.\n");
3576 goto out;
3577 }
3578
3579 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3580 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3581
3582 err = -EBUSY;
3583 if (!closing) {
3584 if (atomic_read(&po->mapped))
3585 goto out;
3586 if (atomic_read(&rb->pending))
3587 goto out;
3588 }
3589
3590 if (req->tp_block_nr) {
3591 /* Sanity tests and some calculations */
3592 err = -EBUSY;
3593 if (unlikely(rb->pg_vec))
3594 goto out;
3595
3596 switch (po->tp_version) {
3597 case TPACKET_V1:
3598 po->tp_hdrlen = TPACKET_HDRLEN;
3599 break;
3600 case TPACKET_V2:
3601 po->tp_hdrlen = TPACKET2_HDRLEN;
3602 break;
3603 case TPACKET_V3:
3604 po->tp_hdrlen = TPACKET3_HDRLEN;
3605 break;
3606 }
3607
3608 err = -EINVAL;
3609 if (unlikely((int)req->tp_block_size <= 0))
3610 goto out;
3611 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3612 goto out;
3613 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3614 po->tp_reserve))
3615 goto out;
3616 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3617 goto out;
3618
3619 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3620 if (unlikely(rb->frames_per_block <= 0))
3621 goto out;
3622 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3623 req->tp_frame_nr))
3624 goto out;
3625
3626 err = -ENOMEM;
3627 order = get_order(req->tp_block_size);
3628 pg_vec = alloc_pg_vec(req, order);
3629 if (unlikely(!pg_vec))
3630 goto out;
3631 switch (po->tp_version) {
3632 case TPACKET_V3:
3633 /* Transmit path is not supported. We checked
3634 * it above but just being paranoid
3635 */
3636 if (!tx_ring)
3637 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3638 break;
3639 default:
3640 break;
3641 }
3642 }
3643 /* Done */
3644 else {
3645 err = -EINVAL;
3646 if (unlikely(req->tp_frame_nr))
3647 goto out;
3648 }
3649
3650 lock_sock(sk);
3651
3652 /* Detach socket from network */
3653 spin_lock(&po->bind_lock);
3654 was_running = po->running;
3655 num = po->num;
3656 if (was_running) {
3657 po->num = 0;
3658 __unregister_prot_hook(sk, false);
3659 }
3660 spin_unlock(&po->bind_lock);
3661
3662 synchronize_net();
3663
3664 err = -EBUSY;
3665 mutex_lock(&po->pg_vec_lock);
3666 if (closing || atomic_read(&po->mapped) == 0) {
3667 err = 0;
3668 spin_lock_bh(&rb_queue->lock);
3669 swap(rb->pg_vec, pg_vec);
3670 rb->frame_max = (req->tp_frame_nr - 1);
3671 rb->head = 0;
3672 rb->frame_size = req->tp_frame_size;
3673 spin_unlock_bh(&rb_queue->lock);
3674
3675 swap(rb->pg_vec_order, order);
3676 swap(rb->pg_vec_len, req->tp_block_nr);
3677
3678 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3679 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3680 tpacket_rcv : packet_rcv;
3681 skb_queue_purge(rb_queue);
3682 if (atomic_read(&po->mapped))
3683 pr_err("packet_mmap: vma is busy: %d\n",
3684 atomic_read(&po->mapped));
3685 }
3686 mutex_unlock(&po->pg_vec_lock);
3687
3688 spin_lock(&po->bind_lock);
3689 if (was_running) {
3690 po->num = num;
3691 register_prot_hook(sk);
3692 }
3693 spin_unlock(&po->bind_lock);
3694 if (closing && (po->tp_version > TPACKET_V2)) {
3695 /* Because we don't support block-based V3 on tx-ring */
3696 if (!tx_ring)
3697 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3698 }
3699 release_sock(sk);
3700
3701 if (pg_vec)
3702 free_pg_vec(pg_vec, order, req->tp_block_nr);
3703 out:
3704 return err;
3705 }
3706
3707 static int packet_mmap(struct file *file, struct socket *sock,
3708 struct vm_area_struct *vma)
3709 {
3710 struct sock *sk = sock->sk;
3711 struct packet_sock *po = pkt_sk(sk);
3712 unsigned long size, expected_size;
3713 struct packet_ring_buffer *rb;
3714 unsigned long start;
3715 int err = -EINVAL;
3716 int i;
3717
3718 if (vma->vm_pgoff)
3719 return -EINVAL;
3720
3721 mutex_lock(&po->pg_vec_lock);
3722
3723 expected_size = 0;
3724 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3725 if (rb->pg_vec) {
3726 expected_size += rb->pg_vec_len
3727 * rb->pg_vec_pages
3728 * PAGE_SIZE;
3729 }
3730 }
3731
3732 if (expected_size == 0)
3733 goto out;
3734
3735 size = vma->vm_end - vma->vm_start;
3736 if (size != expected_size)
3737 goto out;
3738
3739 start = vma->vm_start;
3740 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3741 if (rb->pg_vec == NULL)
3742 continue;
3743
3744 for (i = 0; i < rb->pg_vec_len; i++) {
3745 struct page *page;
3746 void *kaddr = rb->pg_vec[i].buffer;
3747 int pg_num;
3748
3749 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3750 page = pgv_to_page(kaddr);
3751 err = vm_insert_page(vma, start, page);
3752 if (unlikely(err))
3753 goto out;
3754 start += PAGE_SIZE;
3755 kaddr += PAGE_SIZE;
3756 }
3757 }
3758 }
3759
3760 atomic_inc(&po->mapped);
3761 vma->vm_ops = &packet_mmap_ops;
3762 err = 0;
3763
3764 out:
3765 mutex_unlock(&po->pg_vec_lock);
3766 return err;
3767 }
3768
3769 static const struct proto_ops packet_ops_spkt = {
3770 .family = PF_PACKET,
3771 .owner = THIS_MODULE,
3772 .release = packet_release,
3773 .bind = packet_bind_spkt,
3774 .connect = sock_no_connect,
3775 .socketpair = sock_no_socketpair,
3776 .accept = sock_no_accept,
3777 .getname = packet_getname_spkt,
3778 .poll = datagram_poll,
3779 .ioctl = packet_ioctl,
3780 .listen = sock_no_listen,
3781 .shutdown = sock_no_shutdown,
3782 .setsockopt = sock_no_setsockopt,
3783 .getsockopt = sock_no_getsockopt,
3784 .sendmsg = packet_sendmsg_spkt,
3785 .recvmsg = packet_recvmsg,
3786 .mmap = sock_no_mmap,
3787 .sendpage = sock_no_sendpage,
3788 };
3789
3790 static const struct proto_ops packet_ops = {
3791 .family = PF_PACKET,
3792 .owner = THIS_MODULE,
3793 .release = packet_release,
3794 .bind = packet_bind,
3795 .connect = sock_no_connect,
3796 .socketpair = sock_no_socketpair,
3797 .accept = sock_no_accept,
3798 .getname = packet_getname,
3799 .poll = packet_poll,
3800 .ioctl = packet_ioctl,
3801 .listen = sock_no_listen,
3802 .shutdown = sock_no_shutdown,
3803 .setsockopt = packet_setsockopt,
3804 .getsockopt = packet_getsockopt,
3805 .sendmsg = packet_sendmsg,
3806 .recvmsg = packet_recvmsg,
3807 .mmap = packet_mmap,
3808 .sendpage = sock_no_sendpage,
3809 };
3810
3811 static const struct net_proto_family packet_family_ops = {
3812 .family = PF_PACKET,
3813 .create = packet_create,
3814 .owner = THIS_MODULE,
3815 };
3816
3817 static struct notifier_block packet_netdev_notifier = {
3818 .notifier_call = packet_notifier,
3819 };
3820
3821 #ifdef CONFIG_PROC_FS
3822
3823 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3824 __acquires(RCU)
3825 {
3826 struct net *net = seq_file_net(seq);
3827
3828 rcu_read_lock();
3829 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3830 }
3831
3832 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3833 {
3834 struct net *net = seq_file_net(seq);
3835 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3836 }
3837
3838 static void packet_seq_stop(struct seq_file *seq, void *v)
3839 __releases(RCU)
3840 {
3841 rcu_read_unlock();
3842 }
3843
3844 static int packet_seq_show(struct seq_file *seq, void *v)
3845 {
3846 if (v == SEQ_START_TOKEN)
3847 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3848 else {
3849 struct sock *s = sk_entry(v);
3850 const struct packet_sock *po = pkt_sk(s);
3851
3852 seq_printf(seq,
3853 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3854 s,
3855 atomic_read(&s->sk_refcnt),
3856 s->sk_type,
3857 ntohs(po->num),
3858 po->ifindex,
3859 po->running,
3860 atomic_read(&s->sk_rmem_alloc),
3861 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3862 sock_i_ino(s));
3863 }
3864
3865 return 0;
3866 }
3867
3868 static const struct seq_operations packet_seq_ops = {
3869 .start = packet_seq_start,
3870 .next = packet_seq_next,
3871 .stop = packet_seq_stop,
3872 .show = packet_seq_show,
3873 };
3874
3875 static int packet_seq_open(struct inode *inode, struct file *file)
3876 {
3877 return seq_open_net(inode, file, &packet_seq_ops,
3878 sizeof(struct seq_net_private));
3879 }
3880
3881 static const struct file_operations packet_seq_fops = {
3882 .owner = THIS_MODULE,
3883 .open = packet_seq_open,
3884 .read = seq_read,
3885 .llseek = seq_lseek,
3886 .release = seq_release_net,
3887 };
3888
3889 #endif
3890
3891 static int __net_init packet_net_init(struct net *net)
3892 {
3893 mutex_init(&net->packet.sklist_lock);
3894 INIT_HLIST_HEAD(&net->packet.sklist);
3895
3896 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
3897 return -ENOMEM;
3898
3899 return 0;
3900 }
3901
3902 static void __net_exit packet_net_exit(struct net *net)
3903 {
3904 remove_proc_entry("packet", net->proc_net);
3905 }
3906
3907 static struct pernet_operations packet_net_ops = {
3908 .init = packet_net_init,
3909 .exit = packet_net_exit,
3910 };
3911
3912
3913 static void __exit packet_exit(void)
3914 {
3915 unregister_netdevice_notifier(&packet_netdev_notifier);
3916 unregister_pernet_subsys(&packet_net_ops);
3917 sock_unregister(PF_PACKET);
3918 proto_unregister(&packet_proto);
3919 }
3920
3921 static int __init packet_init(void)
3922 {
3923 int rc = proto_register(&packet_proto, 0);
3924
3925 if (rc != 0)
3926 goto out;
3927
3928 sock_register(&packet_family_ops);
3929 register_pernet_subsys(&packet_net_ops);
3930 register_netdevice_notifier(&packet_netdev_notifier);
3931 out:
3932 return rc;
3933 }
3934
3935 module_init(packet_init);
3936 module_exit(packet_exit);
3937 MODULE_LICENSE("GPL");
3938 MODULE_ALIAS_NETPROTO(PF_PACKET);
Linux with added FPC-III support