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net: rework recvmsg handler msg_name and msg_namelen logic
[mirror_ubuntu-artful-kernel.git] / net / packet / af_packet.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PACKET - implements raw packet sockets.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 *
12 * Fixes:
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
41 * and packet_mreq.
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
44 * layer.
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
46 *
47 *
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
52 *
53 */
54
55 #include <linux/types.h>
56 #include <linux/mm.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
60 #include <linux/in.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
70 #include <net/ip.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
73 #include <net/sock.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <asm/uaccess.h>
77 #include <asm/ioctls.h>
78 #include <asm/page.h>
79 #include <asm/cacheflush.h>
80 #include <asm/io.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91 #include <linux/reciprocal_div.h>
92 #ifdef CONFIG_INET
93 #include <net/inet_common.h>
94 #endif
95
96 #include "internal.h"
97
98 /*
99 Assumptions:
100 - if device has no dev->hard_header routine, it adds and removes ll header
101 inside itself. In this case ll header is invisible outside of device,
102 but higher levels still should reserve dev->hard_header_len.
103 Some devices are enough clever to reallocate skb, when header
104 will not fit to reserved space (tunnel), another ones are silly
105 (PPP).
106 - packet socket receives packets with pulled ll header,
107 so that SOCK_RAW should push it back.
108
109 On receive:
110 -----------
111
112 Incoming, dev->hard_header!=NULL
113 mac_header -> ll header
114 data -> data
115
116 Outgoing, dev->hard_header!=NULL
117 mac_header -> ll header
118 data -> ll header
119
120 Incoming, dev->hard_header==NULL
121 mac_header -> UNKNOWN position. It is very likely, that it points to ll
122 header. PPP makes it, that is wrong, because introduce
123 assymetry between rx and tx paths.
124 data -> data
125
126 Outgoing, dev->hard_header==NULL
127 mac_header -> data. ll header is still not built!
128 data -> data
129
130 Resume
131 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
132
133
134 On transmit:
135 ------------
136
137 dev->hard_header != NULL
138 mac_header -> ll header
139 data -> ll header
140
141 dev->hard_header == NULL (ll header is added by device, we cannot control it)
142 mac_header -> data
143 data -> data
144
145 We should set nh.raw on output to correct posistion,
146 packet classifier depends on it.
147 */
148
149 /* Private packet socket structures. */
150
151 /* identical to struct packet_mreq except it has
152 * a longer address field.
153 */
154 struct packet_mreq_max {
155 int mr_ifindex;
156 unsigned short mr_type;
157 unsigned short mr_alen;
158 unsigned char mr_address[MAX_ADDR_LEN];
159 };
160
161 union tpacket_uhdr {
162 struct tpacket_hdr *h1;
163 struct tpacket2_hdr *h2;
164 struct tpacket3_hdr *h3;
165 void *raw;
166 };
167
168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
169 int closing, int tx_ring);
170
171 #define V3_ALIGNMENT (8)
172
173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
174
175 #define BLK_PLUS_PRIV(sz_of_priv) \
176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
177
178 #define PGV_FROM_VMALLOC 1
179
180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
181 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
182 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
183 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
184 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
186 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
187
188 struct packet_sock;
189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
191 struct packet_type *pt, struct net_device *orig_dev);
192
193 static void *packet_previous_frame(struct packet_sock *po,
194 struct packet_ring_buffer *rb,
195 int status);
196 static void packet_increment_head(struct packet_ring_buffer *buff);
197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
198 struct tpacket_block_desc *);
199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
200 struct packet_sock *);
201 static void prb_retire_current_block(struct tpacket_kbdq_core *,
202 struct packet_sock *, unsigned int status);
203 static int prb_queue_frozen(struct tpacket_kbdq_core *);
204 static void prb_open_block(struct tpacket_kbdq_core *,
205 struct tpacket_block_desc *);
206 static void prb_retire_rx_blk_timer_expired(unsigned long);
207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
208 static void prb_init_blk_timer(struct packet_sock *,
209 struct tpacket_kbdq_core *,
210 void (*func) (unsigned long));
211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
212 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
213 struct tpacket3_hdr *);
214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
215 struct tpacket3_hdr *);
216 static void packet_flush_mclist(struct sock *sk);
217
218 struct packet_skb_cb {
219 unsigned int origlen;
220 union {
221 struct sockaddr_pkt pkt;
222 struct sockaddr_ll ll;
223 } sa;
224 };
225
226 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
227
228 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
229 #define GET_PBLOCK_DESC(x, bid) \
230 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
232 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
233 #define GET_NEXT_PRB_BLK_NUM(x) \
234 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
235 ((x)->kactive_blk_num+1) : 0)
236
237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
238 static void __fanout_link(struct sock *sk, struct packet_sock *po);
239
240 /* register_prot_hook must be invoked with the po->bind_lock held,
241 * or from a context in which asynchronous accesses to the packet
242 * socket is not possible (packet_create()).
243 */
244 static void register_prot_hook(struct sock *sk)
245 {
246 struct packet_sock *po = pkt_sk(sk);
247 if (!po->running) {
248 if (po->fanout)
249 __fanout_link(sk, po);
250 else
251 dev_add_pack(&po->prot_hook);
252 sock_hold(sk);
253 po->running = 1;
254 }
255 }
256
257 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
258 * held. If the sync parameter is true, we will temporarily drop
259 * the po->bind_lock and do a synchronize_net to make sure no
260 * asynchronous packet processing paths still refer to the elements
261 * of po->prot_hook. If the sync parameter is false, it is the
262 * callers responsibility to take care of this.
263 */
264 static void __unregister_prot_hook(struct sock *sk, bool sync)
265 {
266 struct packet_sock *po = pkt_sk(sk);
267
268 po->running = 0;
269 if (po->fanout)
270 __fanout_unlink(sk, po);
271 else
272 __dev_remove_pack(&po->prot_hook);
273 __sock_put(sk);
274
275 if (sync) {
276 spin_unlock(&po->bind_lock);
277 synchronize_net();
278 spin_lock(&po->bind_lock);
279 }
280 }
281
282 static void unregister_prot_hook(struct sock *sk, bool sync)
283 {
284 struct packet_sock *po = pkt_sk(sk);
285
286 if (po->running)
287 __unregister_prot_hook(sk, sync);
288 }
289
290 static inline __pure struct page *pgv_to_page(void *addr)
291 {
292 if (is_vmalloc_addr(addr))
293 return vmalloc_to_page(addr);
294 return virt_to_page(addr);
295 }
296
297 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
298 {
299 union tpacket_uhdr h;
300
301 h.raw = frame;
302 switch (po->tp_version) {
303 case TPACKET_V1:
304 h.h1->tp_status = status;
305 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
306 break;
307 case TPACKET_V2:
308 h.h2->tp_status = status;
309 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
310 break;
311 case TPACKET_V3:
312 default:
313 WARN(1, "TPACKET version not supported.\n");
314 BUG();
315 }
316
317 smp_wmb();
318 }
319
320 static int __packet_get_status(struct packet_sock *po, void *frame)
321 {
322 union tpacket_uhdr h;
323
324 smp_rmb();
325
326 h.raw = frame;
327 switch (po->tp_version) {
328 case TPACKET_V1:
329 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
330 return h.h1->tp_status;
331 case TPACKET_V2:
332 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
333 return h.h2->tp_status;
334 case TPACKET_V3:
335 default:
336 WARN(1, "TPACKET version not supported.\n");
337 BUG();
338 return 0;
339 }
340 }
341
342 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
343 unsigned int flags)
344 {
345 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
346
347 if (shhwtstamps) {
348 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
349 ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
350 return TP_STATUS_TS_SYS_HARDWARE;
351 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
352 ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
353 return TP_STATUS_TS_RAW_HARDWARE;
354 }
355
356 if (ktime_to_timespec_cond(skb->tstamp, ts))
357 return TP_STATUS_TS_SOFTWARE;
358
359 return 0;
360 }
361
362 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
363 struct sk_buff *skb)
364 {
365 union tpacket_uhdr h;
366 struct timespec ts;
367 __u32 ts_status;
368
369 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
370 return 0;
371
372 h.raw = frame;
373 switch (po->tp_version) {
374 case TPACKET_V1:
375 h.h1->tp_sec = ts.tv_sec;
376 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
377 break;
378 case TPACKET_V2:
379 h.h2->tp_sec = ts.tv_sec;
380 h.h2->tp_nsec = ts.tv_nsec;
381 break;
382 case TPACKET_V3:
383 default:
384 WARN(1, "TPACKET version not supported.\n");
385 BUG();
386 }
387
388 /* one flush is safe, as both fields always lie on the same cacheline */
389 flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
390 smp_wmb();
391
392 return ts_status;
393 }
394
395 static void *packet_lookup_frame(struct packet_sock *po,
396 struct packet_ring_buffer *rb,
397 unsigned int position,
398 int status)
399 {
400 unsigned int pg_vec_pos, frame_offset;
401 union tpacket_uhdr h;
402
403 pg_vec_pos = position / rb->frames_per_block;
404 frame_offset = position % rb->frames_per_block;
405
406 h.raw = rb->pg_vec[pg_vec_pos].buffer +
407 (frame_offset * rb->frame_size);
408
409 if (status != __packet_get_status(po, h.raw))
410 return NULL;
411
412 return h.raw;
413 }
414
415 static void *packet_current_frame(struct packet_sock *po,
416 struct packet_ring_buffer *rb,
417 int status)
418 {
419 return packet_lookup_frame(po, rb, rb->head, status);
420 }
421
422 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
423 {
424 del_timer_sync(&pkc->retire_blk_timer);
425 }
426
427 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
428 int tx_ring,
429 struct sk_buff_head *rb_queue)
430 {
431 struct tpacket_kbdq_core *pkc;
432
433 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
434
435 spin_lock(&rb_queue->lock);
436 pkc->delete_blk_timer = 1;
437 spin_unlock(&rb_queue->lock);
438
439 prb_del_retire_blk_timer(pkc);
440 }
441
442 static void prb_init_blk_timer(struct packet_sock *po,
443 struct tpacket_kbdq_core *pkc,
444 void (*func) (unsigned long))
445 {
446 init_timer(&pkc->retire_blk_timer);
447 pkc->retire_blk_timer.data = (long)po;
448 pkc->retire_blk_timer.function = func;
449 pkc->retire_blk_timer.expires = jiffies;
450 }
451
452 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
453 {
454 struct tpacket_kbdq_core *pkc;
455
456 if (tx_ring)
457 BUG();
458
459 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
460 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
461 }
462
463 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
464 int blk_size_in_bytes)
465 {
466 struct net_device *dev;
467 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
468 struct ethtool_cmd ecmd;
469 int err;
470 u32 speed;
471
472 rtnl_lock();
473 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
474 if (unlikely(!dev)) {
475 rtnl_unlock();
476 return DEFAULT_PRB_RETIRE_TOV;
477 }
478 err = __ethtool_get_settings(dev, &ecmd);
479 speed = ethtool_cmd_speed(&ecmd);
480 rtnl_unlock();
481 if (!err) {
482 /*
483 * If the link speed is so slow you don't really
484 * need to worry about perf anyways
485 */
486 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
487 return DEFAULT_PRB_RETIRE_TOV;
488 } else {
489 msec = 1;
490 div = speed / 1000;
491 }
492 }
493
494 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
495
496 if (div)
497 mbits /= div;
498
499 tmo = mbits * msec;
500
501 if (div)
502 return tmo+1;
503 return tmo;
504 }
505
506 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
507 union tpacket_req_u *req_u)
508 {
509 p1->feature_req_word = req_u->req3.tp_feature_req_word;
510 }
511
512 static void init_prb_bdqc(struct packet_sock *po,
513 struct packet_ring_buffer *rb,
514 struct pgv *pg_vec,
515 union tpacket_req_u *req_u, int tx_ring)
516 {
517 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
518 struct tpacket_block_desc *pbd;
519
520 memset(p1, 0x0, sizeof(*p1));
521
522 p1->knxt_seq_num = 1;
523 p1->pkbdq = pg_vec;
524 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
525 p1->pkblk_start = pg_vec[0].buffer;
526 p1->kblk_size = req_u->req3.tp_block_size;
527 p1->knum_blocks = req_u->req3.tp_block_nr;
528 p1->hdrlen = po->tp_hdrlen;
529 p1->version = po->tp_version;
530 p1->last_kactive_blk_num = 0;
531 po->stats.stats3.tp_freeze_q_cnt = 0;
532 if (req_u->req3.tp_retire_blk_tov)
533 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
534 else
535 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
536 req_u->req3.tp_block_size);
537 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
538 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
539
540 prb_init_ft_ops(p1, req_u);
541 prb_setup_retire_blk_timer(po, tx_ring);
542 prb_open_block(p1, pbd);
543 }
544
545 /* Do NOT update the last_blk_num first.
546 * Assumes sk_buff_head lock is held.
547 */
548 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
549 {
550 mod_timer(&pkc->retire_blk_timer,
551 jiffies + pkc->tov_in_jiffies);
552 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
553 }
554
555 /*
556 * Timer logic:
557 * 1) We refresh the timer only when we open a block.
558 * By doing this we don't waste cycles refreshing the timer
559 * on packet-by-packet basis.
560 *
561 * With a 1MB block-size, on a 1Gbps line, it will take
562 * i) ~8 ms to fill a block + ii) memcpy etc.
563 * In this cut we are not accounting for the memcpy time.
564 *
565 * So, if the user sets the 'tmo' to 10ms then the timer
566 * will never fire while the block is still getting filled
567 * (which is what we want). However, the user could choose
568 * to close a block early and that's fine.
569 *
570 * But when the timer does fire, we check whether or not to refresh it.
571 * Since the tmo granularity is in msecs, it is not too expensive
572 * to refresh the timer, lets say every '8' msecs.
573 * Either the user can set the 'tmo' or we can derive it based on
574 * a) line-speed and b) block-size.
575 * prb_calc_retire_blk_tmo() calculates the tmo.
576 *
577 */
578 static void prb_retire_rx_blk_timer_expired(unsigned long data)
579 {
580 struct packet_sock *po = (struct packet_sock *)data;
581 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
582 unsigned int frozen;
583 struct tpacket_block_desc *pbd;
584
585 spin_lock(&po->sk.sk_receive_queue.lock);
586
587 frozen = prb_queue_frozen(pkc);
588 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
589
590 if (unlikely(pkc->delete_blk_timer))
591 goto out;
592
593 /* We only need to plug the race when the block is partially filled.
594 * tpacket_rcv:
595 * lock(); increment BLOCK_NUM_PKTS; unlock()
596 * copy_bits() is in progress ...
597 * timer fires on other cpu:
598 * we can't retire the current block because copy_bits
599 * is in progress.
600 *
601 */
602 if (BLOCK_NUM_PKTS(pbd)) {
603 while (atomic_read(&pkc->blk_fill_in_prog)) {
604 /* Waiting for skb_copy_bits to finish... */
605 cpu_relax();
606 }
607 }
608
609 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
610 if (!frozen) {
611 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
612 if (!prb_dispatch_next_block(pkc, po))
613 goto refresh_timer;
614 else
615 goto out;
616 } else {
617 /* Case 1. Queue was frozen because user-space was
618 * lagging behind.
619 */
620 if (prb_curr_blk_in_use(pkc, pbd)) {
621 /*
622 * Ok, user-space is still behind.
623 * So just refresh the timer.
624 */
625 goto refresh_timer;
626 } else {
627 /* Case 2. queue was frozen,user-space caught up,
628 * now the link went idle && the timer fired.
629 * We don't have a block to close.So we open this
630 * block and restart the timer.
631 * opening a block thaws the queue,restarts timer
632 * Thawing/timer-refresh is a side effect.
633 */
634 prb_open_block(pkc, pbd);
635 goto out;
636 }
637 }
638 }
639
640 refresh_timer:
641 _prb_refresh_rx_retire_blk_timer(pkc);
642
643 out:
644 spin_unlock(&po->sk.sk_receive_queue.lock);
645 }
646
647 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
648 struct tpacket_block_desc *pbd1, __u32 status)
649 {
650 /* Flush everything minus the block header */
651
652 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
653 u8 *start, *end;
654
655 start = (u8 *)pbd1;
656
657 /* Skip the block header(we know header WILL fit in 4K) */
658 start += PAGE_SIZE;
659
660 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
661 for (; start < end; start += PAGE_SIZE)
662 flush_dcache_page(pgv_to_page(start));
663
664 smp_wmb();
665 #endif
666
667 /* Now update the block status. */
668
669 BLOCK_STATUS(pbd1) = status;
670
671 /* Flush the block header */
672
673 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
674 start = (u8 *)pbd1;
675 flush_dcache_page(pgv_to_page(start));
676
677 smp_wmb();
678 #endif
679 }
680
681 /*
682 * Side effect:
683 *
684 * 1) flush the block
685 * 2) Increment active_blk_num
686 *
687 * Note:We DONT refresh the timer on purpose.
688 * Because almost always the next block will be opened.
689 */
690 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
691 struct tpacket_block_desc *pbd1,
692 struct packet_sock *po, unsigned int stat)
693 {
694 __u32 status = TP_STATUS_USER | stat;
695
696 struct tpacket3_hdr *last_pkt;
697 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
698
699 if (po->stats.stats3.tp_drops)
700 status |= TP_STATUS_LOSING;
701
702 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
703 last_pkt->tp_next_offset = 0;
704
705 /* Get the ts of the last pkt */
706 if (BLOCK_NUM_PKTS(pbd1)) {
707 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
708 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
709 } else {
710 /* Ok, we tmo'd - so get the current time */
711 struct timespec ts;
712 getnstimeofday(&ts);
713 h1->ts_last_pkt.ts_sec = ts.tv_sec;
714 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
715 }
716
717 smp_wmb();
718
719 /* Flush the block */
720 prb_flush_block(pkc1, pbd1, status);
721
722 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
723 }
724
725 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
726 {
727 pkc->reset_pending_on_curr_blk = 0;
728 }
729
730 /*
731 * Side effect of opening a block:
732 *
733 * 1) prb_queue is thawed.
734 * 2) retire_blk_timer is refreshed.
735 *
736 */
737 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
738 struct tpacket_block_desc *pbd1)
739 {
740 struct timespec ts;
741 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
742
743 smp_rmb();
744
745 /* We could have just memset this but we will lose the
746 * flexibility of making the priv area sticky
747 */
748
749 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
750 BLOCK_NUM_PKTS(pbd1) = 0;
751 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
752
753 getnstimeofday(&ts);
754
755 h1->ts_first_pkt.ts_sec = ts.tv_sec;
756 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
757
758 pkc1->pkblk_start = (char *)pbd1;
759 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
760
761 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
762 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
763
764 pbd1->version = pkc1->version;
765 pkc1->prev = pkc1->nxt_offset;
766 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
767
768 prb_thaw_queue(pkc1);
769 _prb_refresh_rx_retire_blk_timer(pkc1);
770
771 smp_wmb();
772 }
773
774 /*
775 * Queue freeze logic:
776 * 1) Assume tp_block_nr = 8 blocks.
777 * 2) At time 't0', user opens Rx ring.
778 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
779 * 4) user-space is either sleeping or processing block '0'.
780 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
781 * it will close block-7,loop around and try to fill block '0'.
782 * call-flow:
783 * __packet_lookup_frame_in_block
784 * prb_retire_current_block()
785 * prb_dispatch_next_block()
786 * |->(BLOCK_STATUS == USER) evaluates to true
787 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
788 * 6) Now there are two cases:
789 * 6.1) Link goes idle right after the queue is frozen.
790 * But remember, the last open_block() refreshed the timer.
791 * When this timer expires,it will refresh itself so that we can
792 * re-open block-0 in near future.
793 * 6.2) Link is busy and keeps on receiving packets. This is a simple
794 * case and __packet_lookup_frame_in_block will check if block-0
795 * is free and can now be re-used.
796 */
797 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
798 struct packet_sock *po)
799 {
800 pkc->reset_pending_on_curr_blk = 1;
801 po->stats.stats3.tp_freeze_q_cnt++;
802 }
803
804 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
805
806 /*
807 * If the next block is free then we will dispatch it
808 * and return a good offset.
809 * Else, we will freeze the queue.
810 * So, caller must check the return value.
811 */
812 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
813 struct packet_sock *po)
814 {
815 struct tpacket_block_desc *pbd;
816
817 smp_rmb();
818
819 /* 1. Get current block num */
820 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
821
822 /* 2. If this block is currently in_use then freeze the queue */
823 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
824 prb_freeze_queue(pkc, po);
825 return NULL;
826 }
827
828 /*
829 * 3.
830 * open this block and return the offset where the first packet
831 * needs to get stored.
832 */
833 prb_open_block(pkc, pbd);
834 return (void *)pkc->nxt_offset;
835 }
836
837 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
838 struct packet_sock *po, unsigned int status)
839 {
840 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
841
842 /* retire/close the current block */
843 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
844 /*
845 * Plug the case where copy_bits() is in progress on
846 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
847 * have space to copy the pkt in the current block and
848 * called prb_retire_current_block()
849 *
850 * We don't need to worry about the TMO case because
851 * the timer-handler already handled this case.
852 */
853 if (!(status & TP_STATUS_BLK_TMO)) {
854 while (atomic_read(&pkc->blk_fill_in_prog)) {
855 /* Waiting for skb_copy_bits to finish... */
856 cpu_relax();
857 }
858 }
859 prb_close_block(pkc, pbd, po, status);
860 return;
861 }
862 }
863
864 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
865 struct tpacket_block_desc *pbd)
866 {
867 return TP_STATUS_USER & BLOCK_STATUS(pbd);
868 }
869
870 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
871 {
872 return pkc->reset_pending_on_curr_blk;
873 }
874
875 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
876 {
877 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
878 atomic_dec(&pkc->blk_fill_in_prog);
879 }
880
881 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
882 struct tpacket3_hdr *ppd)
883 {
884 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
885 }
886
887 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
888 struct tpacket3_hdr *ppd)
889 {
890 ppd->hv1.tp_rxhash = 0;
891 }
892
893 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
894 struct tpacket3_hdr *ppd)
895 {
896 if (vlan_tx_tag_present(pkc->skb)) {
897 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
898 ppd->tp_status = TP_STATUS_VLAN_VALID;
899 } else {
900 ppd->hv1.tp_vlan_tci = 0;
901 ppd->tp_status = TP_STATUS_AVAILABLE;
902 }
903 }
904
905 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
906 struct tpacket3_hdr *ppd)
907 {
908 prb_fill_vlan_info(pkc, ppd);
909
910 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
911 prb_fill_rxhash(pkc, ppd);
912 else
913 prb_clear_rxhash(pkc, ppd);
914 }
915
916 static void prb_fill_curr_block(char *curr,
917 struct tpacket_kbdq_core *pkc,
918 struct tpacket_block_desc *pbd,
919 unsigned int len)
920 {
921 struct tpacket3_hdr *ppd;
922
923 ppd = (struct tpacket3_hdr *)curr;
924 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
925 pkc->prev = curr;
926 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
927 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
928 BLOCK_NUM_PKTS(pbd) += 1;
929 atomic_inc(&pkc->blk_fill_in_prog);
930 prb_run_all_ft_ops(pkc, ppd);
931 }
932
933 /* Assumes caller has the sk->rx_queue.lock */
934 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
935 struct sk_buff *skb,
936 int status,
937 unsigned int len
938 )
939 {
940 struct tpacket_kbdq_core *pkc;
941 struct tpacket_block_desc *pbd;
942 char *curr, *end;
943
944 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
945 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
946
947 /* Queue is frozen when user space is lagging behind */
948 if (prb_queue_frozen(pkc)) {
949 /*
950 * Check if that last block which caused the queue to freeze,
951 * is still in_use by user-space.
952 */
953 if (prb_curr_blk_in_use(pkc, pbd)) {
954 /* Can't record this packet */
955 return NULL;
956 } else {
957 /*
958 * Ok, the block was released by user-space.
959 * Now let's open that block.
960 * opening a block also thaws the queue.
961 * Thawing is a side effect.
962 */
963 prb_open_block(pkc, pbd);
964 }
965 }
966
967 smp_mb();
968 curr = pkc->nxt_offset;
969 pkc->skb = skb;
970 end = (char *)pbd + pkc->kblk_size;
971
972 /* first try the current block */
973 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
974 prb_fill_curr_block(curr, pkc, pbd, len);
975 return (void *)curr;
976 }
977
978 /* Ok, close the current block */
979 prb_retire_current_block(pkc, po, 0);
980
981 /* Now, try to dispatch the next block */
982 curr = (char *)prb_dispatch_next_block(pkc, po);
983 if (curr) {
984 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
985 prb_fill_curr_block(curr, pkc, pbd, len);
986 return (void *)curr;
987 }
988
989 /*
990 * No free blocks are available.user_space hasn't caught up yet.
991 * Queue was just frozen and now this packet will get dropped.
992 */
993 return NULL;
994 }
995
996 static void *packet_current_rx_frame(struct packet_sock *po,
997 struct sk_buff *skb,
998 int status, unsigned int len)
999 {
1000 char *curr = NULL;
1001 switch (po->tp_version) {
1002 case TPACKET_V1:
1003 case TPACKET_V2:
1004 curr = packet_lookup_frame(po, &po->rx_ring,
1005 po->rx_ring.head, status);
1006 return curr;
1007 case TPACKET_V3:
1008 return __packet_lookup_frame_in_block(po, skb, status, len);
1009 default:
1010 WARN(1, "TPACKET version not supported\n");
1011 BUG();
1012 return NULL;
1013 }
1014 }
1015
1016 static void *prb_lookup_block(struct packet_sock *po,
1017 struct packet_ring_buffer *rb,
1018 unsigned int idx,
1019 int status)
1020 {
1021 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1022 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1023
1024 if (status != BLOCK_STATUS(pbd))
1025 return NULL;
1026 return pbd;
1027 }
1028
1029 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1030 {
1031 unsigned int prev;
1032 if (rb->prb_bdqc.kactive_blk_num)
1033 prev = rb->prb_bdqc.kactive_blk_num-1;
1034 else
1035 prev = rb->prb_bdqc.knum_blocks-1;
1036 return prev;
1037 }
1038
1039 /* Assumes caller has held the rx_queue.lock */
1040 static void *__prb_previous_block(struct packet_sock *po,
1041 struct packet_ring_buffer *rb,
1042 int status)
1043 {
1044 unsigned int previous = prb_previous_blk_num(rb);
1045 return prb_lookup_block(po, rb, previous, status);
1046 }
1047
1048 static void *packet_previous_rx_frame(struct packet_sock *po,
1049 struct packet_ring_buffer *rb,
1050 int status)
1051 {
1052 if (po->tp_version <= TPACKET_V2)
1053 return packet_previous_frame(po, rb, status);
1054
1055 return __prb_previous_block(po, rb, status);
1056 }
1057
1058 static void packet_increment_rx_head(struct packet_sock *po,
1059 struct packet_ring_buffer *rb)
1060 {
1061 switch (po->tp_version) {
1062 case TPACKET_V1:
1063 case TPACKET_V2:
1064 return packet_increment_head(rb);
1065 case TPACKET_V3:
1066 default:
1067 WARN(1, "TPACKET version not supported.\n");
1068 BUG();
1069 return;
1070 }
1071 }
1072
1073 static void *packet_previous_frame(struct packet_sock *po,
1074 struct packet_ring_buffer *rb,
1075 int status)
1076 {
1077 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1078 return packet_lookup_frame(po, rb, previous, status);
1079 }
1080
1081 static void packet_increment_head(struct packet_ring_buffer *buff)
1082 {
1083 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1084 }
1085
1086 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1087 {
1088 struct sock *sk = &po->sk;
1089 bool has_room;
1090
1091 if (po->prot_hook.func != tpacket_rcv)
1092 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
1093 <= sk->sk_rcvbuf;
1094
1095 spin_lock(&sk->sk_receive_queue.lock);
1096 if (po->tp_version == TPACKET_V3)
1097 has_room = prb_lookup_block(po, &po->rx_ring,
1098 po->rx_ring.prb_bdqc.kactive_blk_num,
1099 TP_STATUS_KERNEL);
1100 else
1101 has_room = packet_lookup_frame(po, &po->rx_ring,
1102 po->rx_ring.head,
1103 TP_STATUS_KERNEL);
1104 spin_unlock(&sk->sk_receive_queue.lock);
1105
1106 return has_room;
1107 }
1108
1109 static void packet_sock_destruct(struct sock *sk)
1110 {
1111 skb_queue_purge(&sk->sk_error_queue);
1112
1113 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1114 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1115
1116 if (!sock_flag(sk, SOCK_DEAD)) {
1117 pr_err("Attempt to release alive packet socket: %p\n", sk);
1118 return;
1119 }
1120
1121 sk_refcnt_debug_dec(sk);
1122 }
1123
1124 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1125 {
1126 int x = atomic_read(&f->rr_cur) + 1;
1127
1128 if (x >= num)
1129 x = 0;
1130
1131 return x;
1132 }
1133
1134 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1135 struct sk_buff *skb,
1136 unsigned int num)
1137 {
1138 return reciprocal_divide(skb->rxhash, num);
1139 }
1140
1141 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1142 struct sk_buff *skb,
1143 unsigned int num)
1144 {
1145 int cur, old;
1146
1147 cur = atomic_read(&f->rr_cur);
1148 while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1149 fanout_rr_next(f, num))) != cur)
1150 cur = old;
1151 return cur;
1152 }
1153
1154 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1155 struct sk_buff *skb,
1156 unsigned int num)
1157 {
1158 return smp_processor_id() % num;
1159 }
1160
1161 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1162 struct sk_buff *skb,
1163 unsigned int num)
1164 {
1165 return reciprocal_divide(prandom_u32(), num);
1166 }
1167
1168 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1169 struct sk_buff *skb,
1170 unsigned int idx, unsigned int skip,
1171 unsigned int num)
1172 {
1173 unsigned int i, j;
1174
1175 i = j = min_t(int, f->next[idx], num - 1);
1176 do {
1177 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1178 if (i != j)
1179 f->next[idx] = i;
1180 return i;
1181 }
1182 if (++i == num)
1183 i = 0;
1184 } while (i != j);
1185
1186 return idx;
1187 }
1188
1189 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1190 {
1191 return f->flags & (flag >> 8);
1192 }
1193
1194 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1195 struct packet_type *pt, struct net_device *orig_dev)
1196 {
1197 struct packet_fanout *f = pt->af_packet_priv;
1198 unsigned int num = f->num_members;
1199 struct packet_sock *po;
1200 unsigned int idx;
1201
1202 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1203 !num) {
1204 kfree_skb(skb);
1205 return 0;
1206 }
1207
1208 switch (f->type) {
1209 case PACKET_FANOUT_HASH:
1210 default:
1211 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1212 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1213 if (!skb)
1214 return 0;
1215 }
1216 skb_get_rxhash(skb);
1217 idx = fanout_demux_hash(f, skb, num);
1218 break;
1219 case PACKET_FANOUT_LB:
1220 idx = fanout_demux_lb(f, skb, num);
1221 break;
1222 case PACKET_FANOUT_CPU:
1223 idx = fanout_demux_cpu(f, skb, num);
1224 break;
1225 case PACKET_FANOUT_RND:
1226 idx = fanout_demux_rnd(f, skb, num);
1227 break;
1228 case PACKET_FANOUT_ROLLOVER:
1229 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1230 break;
1231 }
1232
1233 po = pkt_sk(f->arr[idx]);
1234 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1235 unlikely(!packet_rcv_has_room(po, skb))) {
1236 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1237 po = pkt_sk(f->arr[idx]);
1238 }
1239
1240 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1241 }
1242
1243 DEFINE_MUTEX(fanout_mutex);
1244 EXPORT_SYMBOL_GPL(fanout_mutex);
1245 static LIST_HEAD(fanout_list);
1246
1247 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1248 {
1249 struct packet_fanout *f = po->fanout;
1250
1251 spin_lock(&f->lock);
1252 f->arr[f->num_members] = sk;
1253 smp_wmb();
1254 f->num_members++;
1255 spin_unlock(&f->lock);
1256 }
1257
1258 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1259 {
1260 struct packet_fanout *f = po->fanout;
1261 int i;
1262
1263 spin_lock(&f->lock);
1264 for (i = 0; i < f->num_members; i++) {
1265 if (f->arr[i] == sk)
1266 break;
1267 }
1268 BUG_ON(i >= f->num_members);
1269 f->arr[i] = f->arr[f->num_members - 1];
1270 f->num_members--;
1271 spin_unlock(&f->lock);
1272 }
1273
1274 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1275 {
1276 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1277 return true;
1278
1279 return false;
1280 }
1281
1282 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1283 {
1284 struct packet_sock *po = pkt_sk(sk);
1285 struct packet_fanout *f, *match;
1286 u8 type = type_flags & 0xff;
1287 u8 flags = type_flags >> 8;
1288 int err;
1289
1290 switch (type) {
1291 case PACKET_FANOUT_ROLLOVER:
1292 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1293 return -EINVAL;
1294 case PACKET_FANOUT_HASH:
1295 case PACKET_FANOUT_LB:
1296 case PACKET_FANOUT_CPU:
1297 case PACKET_FANOUT_RND:
1298 break;
1299 default:
1300 return -EINVAL;
1301 }
1302
1303 if (!po->running)
1304 return -EINVAL;
1305
1306 if (po->fanout)
1307 return -EALREADY;
1308
1309 mutex_lock(&fanout_mutex);
1310 match = NULL;
1311 list_for_each_entry(f, &fanout_list, list) {
1312 if (f->id == id &&
1313 read_pnet(&f->net) == sock_net(sk)) {
1314 match = f;
1315 break;
1316 }
1317 }
1318 err = -EINVAL;
1319 if (match && match->flags != flags)
1320 goto out;
1321 if (!match) {
1322 err = -ENOMEM;
1323 match = kzalloc(sizeof(*match), GFP_KERNEL);
1324 if (!match)
1325 goto out;
1326 write_pnet(&match->net, sock_net(sk));
1327 match->id = id;
1328 match->type = type;
1329 match->flags = flags;
1330 atomic_set(&match->rr_cur, 0);
1331 INIT_LIST_HEAD(&match->list);
1332 spin_lock_init(&match->lock);
1333 atomic_set(&match->sk_ref, 0);
1334 match->prot_hook.type = po->prot_hook.type;
1335 match->prot_hook.dev = po->prot_hook.dev;
1336 match->prot_hook.func = packet_rcv_fanout;
1337 match->prot_hook.af_packet_priv = match;
1338 match->prot_hook.id_match = match_fanout_group;
1339 dev_add_pack(&match->prot_hook);
1340 list_add(&match->list, &fanout_list);
1341 }
1342 err = -EINVAL;
1343 if (match->type == type &&
1344 match->prot_hook.type == po->prot_hook.type &&
1345 match->prot_hook.dev == po->prot_hook.dev) {
1346 err = -ENOSPC;
1347 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1348 __dev_remove_pack(&po->prot_hook);
1349 po->fanout = match;
1350 atomic_inc(&match->sk_ref);
1351 __fanout_link(sk, po);
1352 err = 0;
1353 }
1354 }
1355 out:
1356 mutex_unlock(&fanout_mutex);
1357 return err;
1358 }
1359
1360 static void fanout_release(struct sock *sk)
1361 {
1362 struct packet_sock *po = pkt_sk(sk);
1363 struct packet_fanout *f;
1364
1365 f = po->fanout;
1366 if (!f)
1367 return;
1368
1369 mutex_lock(&fanout_mutex);
1370 po->fanout = NULL;
1371
1372 if (atomic_dec_and_test(&f->sk_ref)) {
1373 list_del(&f->list);
1374 dev_remove_pack(&f->prot_hook);
1375 kfree(f);
1376 }
1377 mutex_unlock(&fanout_mutex);
1378 }
1379
1380 static const struct proto_ops packet_ops;
1381
1382 static const struct proto_ops packet_ops_spkt;
1383
1384 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1385 struct packet_type *pt, struct net_device *orig_dev)
1386 {
1387 struct sock *sk;
1388 struct sockaddr_pkt *spkt;
1389
1390 /*
1391 * When we registered the protocol we saved the socket in the data
1392 * field for just this event.
1393 */
1394
1395 sk = pt->af_packet_priv;
1396
1397 /*
1398 * Yank back the headers [hope the device set this
1399 * right or kerboom...]
1400 *
1401 * Incoming packets have ll header pulled,
1402 * push it back.
1403 *
1404 * For outgoing ones skb->data == skb_mac_header(skb)
1405 * so that this procedure is noop.
1406 */
1407
1408 if (skb->pkt_type == PACKET_LOOPBACK)
1409 goto out;
1410
1411 if (!net_eq(dev_net(dev), sock_net(sk)))
1412 goto out;
1413
1414 skb = skb_share_check(skb, GFP_ATOMIC);
1415 if (skb == NULL)
1416 goto oom;
1417
1418 /* drop any routing info */
1419 skb_dst_drop(skb);
1420
1421 /* drop conntrack reference */
1422 nf_reset(skb);
1423
1424 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1425
1426 skb_push(skb, skb->data - skb_mac_header(skb));
1427
1428 /*
1429 * The SOCK_PACKET socket receives _all_ frames.
1430 */
1431
1432 spkt->spkt_family = dev->type;
1433 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1434 spkt->spkt_protocol = skb->protocol;
1435
1436 /*
1437 * Charge the memory to the socket. This is done specifically
1438 * to prevent sockets using all the memory up.
1439 */
1440
1441 if (sock_queue_rcv_skb(sk, skb) == 0)
1442 return 0;
1443
1444 out:
1445 kfree_skb(skb);
1446 oom:
1447 return 0;
1448 }
1449
1450
1451 /*
1452 * Output a raw packet to a device layer. This bypasses all the other
1453 * protocol layers and you must therefore supply it with a complete frame
1454 */
1455
1456 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1457 struct msghdr *msg, size_t len)
1458 {
1459 struct sock *sk = sock->sk;
1460 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1461 struct sk_buff *skb = NULL;
1462 struct net_device *dev;
1463 __be16 proto = 0;
1464 int err;
1465 int extra_len = 0;
1466
1467 /*
1468 * Get and verify the address.
1469 */
1470
1471 if (saddr) {
1472 if (msg->msg_namelen < sizeof(struct sockaddr))
1473 return -EINVAL;
1474 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1475 proto = saddr->spkt_protocol;
1476 } else
1477 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1478
1479 /*
1480 * Find the device first to size check it
1481 */
1482
1483 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1484 retry:
1485 rcu_read_lock();
1486 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1487 err = -ENODEV;
1488 if (dev == NULL)
1489 goto out_unlock;
1490
1491 err = -ENETDOWN;
1492 if (!(dev->flags & IFF_UP))
1493 goto out_unlock;
1494
1495 /*
1496 * You may not queue a frame bigger than the mtu. This is the lowest level
1497 * raw protocol and you must do your own fragmentation at this level.
1498 */
1499
1500 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1501 if (!netif_supports_nofcs(dev)) {
1502 err = -EPROTONOSUPPORT;
1503 goto out_unlock;
1504 }
1505 extra_len = 4; /* We're doing our own CRC */
1506 }
1507
1508 err = -EMSGSIZE;
1509 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1510 goto out_unlock;
1511
1512 if (!skb) {
1513 size_t reserved = LL_RESERVED_SPACE(dev);
1514 int tlen = dev->needed_tailroom;
1515 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1516
1517 rcu_read_unlock();
1518 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1519 if (skb == NULL)
1520 return -ENOBUFS;
1521 /* FIXME: Save some space for broken drivers that write a hard
1522 * header at transmission time by themselves. PPP is the notable
1523 * one here. This should really be fixed at the driver level.
1524 */
1525 skb_reserve(skb, reserved);
1526 skb_reset_network_header(skb);
1527
1528 /* Try to align data part correctly */
1529 if (hhlen) {
1530 skb->data -= hhlen;
1531 skb->tail -= hhlen;
1532 if (len < hhlen)
1533 skb_reset_network_header(skb);
1534 }
1535 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1536 if (err)
1537 goto out_free;
1538 goto retry;
1539 }
1540
1541 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1542 /* Earlier code assumed this would be a VLAN pkt,
1543 * double-check this now that we have the actual
1544 * packet in hand.
1545 */
1546 struct ethhdr *ehdr;
1547 skb_reset_mac_header(skb);
1548 ehdr = eth_hdr(skb);
1549 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1550 err = -EMSGSIZE;
1551 goto out_unlock;
1552 }
1553 }
1554
1555 skb->protocol = proto;
1556 skb->dev = dev;
1557 skb->priority = sk->sk_priority;
1558 skb->mark = sk->sk_mark;
1559
1560 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1561
1562 if (unlikely(extra_len == 4))
1563 skb->no_fcs = 1;
1564
1565 skb_probe_transport_header(skb, 0);
1566
1567 dev_queue_xmit(skb);
1568 rcu_read_unlock();
1569 return len;
1570
1571 out_unlock:
1572 rcu_read_unlock();
1573 out_free:
1574 kfree_skb(skb);
1575 return err;
1576 }
1577
1578 static unsigned int run_filter(const struct sk_buff *skb,
1579 const struct sock *sk,
1580 unsigned int res)
1581 {
1582 struct sk_filter *filter;
1583
1584 rcu_read_lock();
1585 filter = rcu_dereference(sk->sk_filter);
1586 if (filter != NULL)
1587 res = SK_RUN_FILTER(filter, skb);
1588 rcu_read_unlock();
1589
1590 return res;
1591 }
1592
1593 /*
1594 * This function makes lazy skb cloning in hope that most of packets
1595 * are discarded by BPF.
1596 *
1597 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1598 * and skb->cb are mangled. It works because (and until) packets
1599 * falling here are owned by current CPU. Output packets are cloned
1600 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1601 * sequencially, so that if we return skb to original state on exit,
1602 * we will not harm anyone.
1603 */
1604
1605 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1606 struct packet_type *pt, struct net_device *orig_dev)
1607 {
1608 struct sock *sk;
1609 struct sockaddr_ll *sll;
1610 struct packet_sock *po;
1611 u8 *skb_head = skb->data;
1612 int skb_len = skb->len;
1613 unsigned int snaplen, res;
1614
1615 if (skb->pkt_type == PACKET_LOOPBACK)
1616 goto drop;
1617
1618 sk = pt->af_packet_priv;
1619 po = pkt_sk(sk);
1620
1621 if (!net_eq(dev_net(dev), sock_net(sk)))
1622 goto drop;
1623
1624 skb->dev = dev;
1625
1626 if (dev->header_ops) {
1627 /* The device has an explicit notion of ll header,
1628 * exported to higher levels.
1629 *
1630 * Otherwise, the device hides details of its frame
1631 * structure, so that corresponding packet head is
1632 * never delivered to user.
1633 */
1634 if (sk->sk_type != SOCK_DGRAM)
1635 skb_push(skb, skb->data - skb_mac_header(skb));
1636 else if (skb->pkt_type == PACKET_OUTGOING) {
1637 /* Special case: outgoing packets have ll header at head */
1638 skb_pull(skb, skb_network_offset(skb));
1639 }
1640 }
1641
1642 snaplen = skb->len;
1643
1644 res = run_filter(skb, sk, snaplen);
1645 if (!res)
1646 goto drop_n_restore;
1647 if (snaplen > res)
1648 snaplen = res;
1649
1650 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1651 goto drop_n_acct;
1652
1653 if (skb_shared(skb)) {
1654 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1655 if (nskb == NULL)
1656 goto drop_n_acct;
1657
1658 if (skb_head != skb->data) {
1659 skb->data = skb_head;
1660 skb->len = skb_len;
1661 }
1662 consume_skb(skb);
1663 skb = nskb;
1664 }
1665
1666 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1667 sizeof(skb->cb));
1668
1669 sll = &PACKET_SKB_CB(skb)->sa.ll;
1670 sll->sll_family = AF_PACKET;
1671 sll->sll_hatype = dev->type;
1672 sll->sll_protocol = skb->protocol;
1673 sll->sll_pkttype = skb->pkt_type;
1674 if (unlikely(po->origdev))
1675 sll->sll_ifindex = orig_dev->ifindex;
1676 else
1677 sll->sll_ifindex = dev->ifindex;
1678
1679 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1680
1681 PACKET_SKB_CB(skb)->origlen = skb->len;
1682
1683 if (pskb_trim(skb, snaplen))
1684 goto drop_n_acct;
1685
1686 skb_set_owner_r(skb, sk);
1687 skb->dev = NULL;
1688 skb_dst_drop(skb);
1689
1690 /* drop conntrack reference */
1691 nf_reset(skb);
1692
1693 spin_lock(&sk->sk_receive_queue.lock);
1694 po->stats.stats1.tp_packets++;
1695 skb->dropcount = atomic_read(&sk->sk_drops);
1696 __skb_queue_tail(&sk->sk_receive_queue, skb);
1697 spin_unlock(&sk->sk_receive_queue.lock);
1698 sk->sk_data_ready(sk, skb->len);
1699 return 0;
1700
1701 drop_n_acct:
1702 spin_lock(&sk->sk_receive_queue.lock);
1703 po->stats.stats1.tp_drops++;
1704 atomic_inc(&sk->sk_drops);
1705 spin_unlock(&sk->sk_receive_queue.lock);
1706
1707 drop_n_restore:
1708 if (skb_head != skb->data && skb_shared(skb)) {
1709 skb->data = skb_head;
1710 skb->len = skb_len;
1711 }
1712 drop:
1713 consume_skb(skb);
1714 return 0;
1715 }
1716
1717 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1718 struct packet_type *pt, struct net_device *orig_dev)
1719 {
1720 struct sock *sk;
1721 struct packet_sock *po;
1722 struct sockaddr_ll *sll;
1723 union tpacket_uhdr h;
1724 u8 *skb_head = skb->data;
1725 int skb_len = skb->len;
1726 unsigned int snaplen, res;
1727 unsigned long status = TP_STATUS_USER;
1728 unsigned short macoff, netoff, hdrlen;
1729 struct sk_buff *copy_skb = NULL;
1730 struct timespec ts;
1731 __u32 ts_status;
1732
1733 if (skb->pkt_type == PACKET_LOOPBACK)
1734 goto drop;
1735
1736 sk = pt->af_packet_priv;
1737 po = pkt_sk(sk);
1738
1739 if (!net_eq(dev_net(dev), sock_net(sk)))
1740 goto drop;
1741
1742 if (dev->header_ops) {
1743 if (sk->sk_type != SOCK_DGRAM)
1744 skb_push(skb, skb->data - skb_mac_header(skb));
1745 else if (skb->pkt_type == PACKET_OUTGOING) {
1746 /* Special case: outgoing packets have ll header at head */
1747 skb_pull(skb, skb_network_offset(skb));
1748 }
1749 }
1750
1751 if (skb->ip_summed == CHECKSUM_PARTIAL)
1752 status |= TP_STATUS_CSUMNOTREADY;
1753
1754 snaplen = skb->len;
1755
1756 res = run_filter(skb, sk, snaplen);
1757 if (!res)
1758 goto drop_n_restore;
1759 if (snaplen > res)
1760 snaplen = res;
1761
1762 if (sk->sk_type == SOCK_DGRAM) {
1763 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1764 po->tp_reserve;
1765 } else {
1766 unsigned int maclen = skb_network_offset(skb);
1767 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1768 (maclen < 16 ? 16 : maclen)) +
1769 po->tp_reserve;
1770 macoff = netoff - maclen;
1771 }
1772 if (po->tp_version <= TPACKET_V2) {
1773 if (macoff + snaplen > po->rx_ring.frame_size) {
1774 if (po->copy_thresh &&
1775 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1776 if (skb_shared(skb)) {
1777 copy_skb = skb_clone(skb, GFP_ATOMIC);
1778 } else {
1779 copy_skb = skb_get(skb);
1780 skb_head = skb->data;
1781 }
1782 if (copy_skb)
1783 skb_set_owner_r(copy_skb, sk);
1784 }
1785 snaplen = po->rx_ring.frame_size - macoff;
1786 if ((int)snaplen < 0)
1787 snaplen = 0;
1788 }
1789 }
1790 spin_lock(&sk->sk_receive_queue.lock);
1791 h.raw = packet_current_rx_frame(po, skb,
1792 TP_STATUS_KERNEL, (macoff+snaplen));
1793 if (!h.raw)
1794 goto ring_is_full;
1795 if (po->tp_version <= TPACKET_V2) {
1796 packet_increment_rx_head(po, &po->rx_ring);
1797 /*
1798 * LOSING will be reported till you read the stats,
1799 * because it's COR - Clear On Read.
1800 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1801 * at packet level.
1802 */
1803 if (po->stats.stats1.tp_drops)
1804 status |= TP_STATUS_LOSING;
1805 }
1806 po->stats.stats1.tp_packets++;
1807 if (copy_skb) {
1808 status |= TP_STATUS_COPY;
1809 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1810 }
1811 spin_unlock(&sk->sk_receive_queue.lock);
1812
1813 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1814
1815 if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1816 getnstimeofday(&ts);
1817
1818 status |= ts_status;
1819
1820 switch (po->tp_version) {
1821 case TPACKET_V1:
1822 h.h1->tp_len = skb->len;
1823 h.h1->tp_snaplen = snaplen;
1824 h.h1->tp_mac = macoff;
1825 h.h1->tp_net = netoff;
1826 h.h1->tp_sec = ts.tv_sec;
1827 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1828 hdrlen = sizeof(*h.h1);
1829 break;
1830 case TPACKET_V2:
1831 h.h2->tp_len = skb->len;
1832 h.h2->tp_snaplen = snaplen;
1833 h.h2->tp_mac = macoff;
1834 h.h2->tp_net = netoff;
1835 h.h2->tp_sec = ts.tv_sec;
1836 h.h2->tp_nsec = ts.tv_nsec;
1837 if (vlan_tx_tag_present(skb)) {
1838 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1839 status |= TP_STATUS_VLAN_VALID;
1840 } else {
1841 h.h2->tp_vlan_tci = 0;
1842 }
1843 h.h2->tp_padding = 0;
1844 hdrlen = sizeof(*h.h2);
1845 break;
1846 case TPACKET_V3:
1847 /* tp_nxt_offset,vlan are already populated above.
1848 * So DONT clear those fields here
1849 */
1850 h.h3->tp_status |= status;
1851 h.h3->tp_len = skb->len;
1852 h.h3->tp_snaplen = snaplen;
1853 h.h3->tp_mac = macoff;
1854 h.h3->tp_net = netoff;
1855 h.h3->tp_sec = ts.tv_sec;
1856 h.h3->tp_nsec = ts.tv_nsec;
1857 hdrlen = sizeof(*h.h3);
1858 break;
1859 default:
1860 BUG();
1861 }
1862
1863 sll = h.raw + TPACKET_ALIGN(hdrlen);
1864 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1865 sll->sll_family = AF_PACKET;
1866 sll->sll_hatype = dev->type;
1867 sll->sll_protocol = skb->protocol;
1868 sll->sll_pkttype = skb->pkt_type;
1869 if (unlikely(po->origdev))
1870 sll->sll_ifindex = orig_dev->ifindex;
1871 else
1872 sll->sll_ifindex = dev->ifindex;
1873
1874 smp_mb();
1875 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1876 {
1877 u8 *start, *end;
1878
1879 if (po->tp_version <= TPACKET_V2) {
1880 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1881 + macoff + snaplen);
1882 for (start = h.raw; start < end; start += PAGE_SIZE)
1883 flush_dcache_page(pgv_to_page(start));
1884 }
1885 smp_wmb();
1886 }
1887 #endif
1888 if (po->tp_version <= TPACKET_V2)
1889 __packet_set_status(po, h.raw, status);
1890 else
1891 prb_clear_blk_fill_status(&po->rx_ring);
1892
1893 sk->sk_data_ready(sk, 0);
1894
1895 drop_n_restore:
1896 if (skb_head != skb->data && skb_shared(skb)) {
1897 skb->data = skb_head;
1898 skb->len = skb_len;
1899 }
1900 drop:
1901 kfree_skb(skb);
1902 return 0;
1903
1904 ring_is_full:
1905 po->stats.stats1.tp_drops++;
1906 spin_unlock(&sk->sk_receive_queue.lock);
1907
1908 sk->sk_data_ready(sk, 0);
1909 kfree_skb(copy_skb);
1910 goto drop_n_restore;
1911 }
1912
1913 static void tpacket_destruct_skb(struct sk_buff *skb)
1914 {
1915 struct packet_sock *po = pkt_sk(skb->sk);
1916 void *ph;
1917
1918 if (likely(po->tx_ring.pg_vec)) {
1919 __u32 ts;
1920
1921 ph = skb_shinfo(skb)->destructor_arg;
1922 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1923 atomic_dec(&po->tx_ring.pending);
1924
1925 ts = __packet_set_timestamp(po, ph, skb);
1926 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
1927 }
1928
1929 sock_wfree(skb);
1930 }
1931
1932 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1933 void *frame, struct net_device *dev, int size_max,
1934 __be16 proto, unsigned char *addr, int hlen)
1935 {
1936 union tpacket_uhdr ph;
1937 int to_write, offset, len, tp_len, nr_frags, len_max;
1938 struct socket *sock = po->sk.sk_socket;
1939 struct page *page;
1940 void *data;
1941 int err;
1942
1943 ph.raw = frame;
1944
1945 skb->protocol = proto;
1946 skb->dev = dev;
1947 skb->priority = po->sk.sk_priority;
1948 skb->mark = po->sk.sk_mark;
1949 sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
1950 skb_shinfo(skb)->destructor_arg = ph.raw;
1951
1952 switch (po->tp_version) {
1953 case TPACKET_V2:
1954 tp_len = ph.h2->tp_len;
1955 break;
1956 default:
1957 tp_len = ph.h1->tp_len;
1958 break;
1959 }
1960 if (unlikely(tp_len > size_max)) {
1961 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1962 return -EMSGSIZE;
1963 }
1964
1965 skb_reserve(skb, hlen);
1966 skb_reset_network_header(skb);
1967 skb_probe_transport_header(skb, 0);
1968
1969 if (po->tp_tx_has_off) {
1970 int off_min, off_max, off;
1971 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
1972 off_max = po->tx_ring.frame_size - tp_len;
1973 if (sock->type == SOCK_DGRAM) {
1974 switch (po->tp_version) {
1975 case TPACKET_V2:
1976 off = ph.h2->tp_net;
1977 break;
1978 default:
1979 off = ph.h1->tp_net;
1980 break;
1981 }
1982 } else {
1983 switch (po->tp_version) {
1984 case TPACKET_V2:
1985 off = ph.h2->tp_mac;
1986 break;
1987 default:
1988 off = ph.h1->tp_mac;
1989 break;
1990 }
1991 }
1992 if (unlikely((off < off_min) || (off_max < off)))
1993 return -EINVAL;
1994 data = ph.raw + off;
1995 } else {
1996 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1997 }
1998 to_write = tp_len;
1999
2000 if (sock->type == SOCK_DGRAM) {
2001 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2002 NULL, tp_len);
2003 if (unlikely(err < 0))
2004 return -EINVAL;
2005 } else if (dev->hard_header_len) {
2006 /* net device doesn't like empty head */
2007 if (unlikely(tp_len <= dev->hard_header_len)) {
2008 pr_err("packet size is too short (%d < %d)\n",
2009 tp_len, dev->hard_header_len);
2010 return -EINVAL;
2011 }
2012
2013 skb_push(skb, dev->hard_header_len);
2014 err = skb_store_bits(skb, 0, data,
2015 dev->hard_header_len);
2016 if (unlikely(err))
2017 return err;
2018
2019 data += dev->hard_header_len;
2020 to_write -= dev->hard_header_len;
2021 }
2022
2023 offset = offset_in_page(data);
2024 len_max = PAGE_SIZE - offset;
2025 len = ((to_write > len_max) ? len_max : to_write);
2026
2027 skb->data_len = to_write;
2028 skb->len += to_write;
2029 skb->truesize += to_write;
2030 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2031
2032 while (likely(to_write)) {
2033 nr_frags = skb_shinfo(skb)->nr_frags;
2034
2035 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2036 pr_err("Packet exceed the number of skb frags(%lu)\n",
2037 MAX_SKB_FRAGS);
2038 return -EFAULT;
2039 }
2040
2041 page = pgv_to_page(data);
2042 data += len;
2043 flush_dcache_page(page);
2044 get_page(page);
2045 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2046 to_write -= len;
2047 offset = 0;
2048 len_max = PAGE_SIZE;
2049 len = ((to_write > len_max) ? len_max : to_write);
2050 }
2051
2052 return tp_len;
2053 }
2054
2055 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2056 {
2057 struct sk_buff *skb;
2058 struct net_device *dev;
2059 __be16 proto;
2060 bool need_rls_dev = false;
2061 int err, reserve = 0;
2062 void *ph;
2063 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2064 int tp_len, size_max;
2065 unsigned char *addr;
2066 int len_sum = 0;
2067 int status = TP_STATUS_AVAILABLE;
2068 int hlen, tlen;
2069
2070 mutex_lock(&po->pg_vec_lock);
2071
2072 if (saddr == NULL) {
2073 dev = po->prot_hook.dev;
2074 proto = po->num;
2075 addr = NULL;
2076 } else {
2077 err = -EINVAL;
2078 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2079 goto out;
2080 if (msg->msg_namelen < (saddr->sll_halen
2081 + offsetof(struct sockaddr_ll,
2082 sll_addr)))
2083 goto out;
2084 proto = saddr->sll_protocol;
2085 addr = saddr->sll_addr;
2086 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2087 need_rls_dev = true;
2088 }
2089
2090 err = -ENXIO;
2091 if (unlikely(dev == NULL))
2092 goto out;
2093
2094 reserve = dev->hard_header_len;
2095
2096 err = -ENETDOWN;
2097 if (unlikely(!(dev->flags & IFF_UP)))
2098 goto out_put;
2099
2100 size_max = po->tx_ring.frame_size
2101 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2102
2103 if (size_max > dev->mtu + reserve)
2104 size_max = dev->mtu + reserve;
2105
2106 do {
2107 ph = packet_current_frame(po, &po->tx_ring,
2108 TP_STATUS_SEND_REQUEST);
2109
2110 if (unlikely(ph == NULL)) {
2111 schedule();
2112 continue;
2113 }
2114
2115 status = TP_STATUS_SEND_REQUEST;
2116 hlen = LL_RESERVED_SPACE(dev);
2117 tlen = dev->needed_tailroom;
2118 skb = sock_alloc_send_skb(&po->sk,
2119 hlen + tlen + sizeof(struct sockaddr_ll),
2120 0, &err);
2121
2122 if (unlikely(skb == NULL))
2123 goto out_status;
2124
2125 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2126 addr, hlen);
2127
2128 if (unlikely(tp_len < 0)) {
2129 if (po->tp_loss) {
2130 __packet_set_status(po, ph,
2131 TP_STATUS_AVAILABLE);
2132 packet_increment_head(&po->tx_ring);
2133 kfree_skb(skb);
2134 continue;
2135 } else {
2136 status = TP_STATUS_WRONG_FORMAT;
2137 err = tp_len;
2138 goto out_status;
2139 }
2140 }
2141
2142 skb->destructor = tpacket_destruct_skb;
2143 __packet_set_status(po, ph, TP_STATUS_SENDING);
2144 atomic_inc(&po->tx_ring.pending);
2145
2146 status = TP_STATUS_SEND_REQUEST;
2147 err = dev_queue_xmit(skb);
2148 if (unlikely(err > 0)) {
2149 err = net_xmit_errno(err);
2150 if (err && __packet_get_status(po, ph) ==
2151 TP_STATUS_AVAILABLE) {
2152 /* skb was destructed already */
2153 skb = NULL;
2154 goto out_status;
2155 }
2156 /*
2157 * skb was dropped but not destructed yet;
2158 * let's treat it like congestion or err < 0
2159 */
2160 err = 0;
2161 }
2162 packet_increment_head(&po->tx_ring);
2163 len_sum += tp_len;
2164 } while (likely((ph != NULL) ||
2165 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2166 (atomic_read(&po->tx_ring.pending))))
2167 );
2168
2169 err = len_sum;
2170 goto out_put;
2171
2172 out_status:
2173 __packet_set_status(po, ph, status);
2174 kfree_skb(skb);
2175 out_put:
2176 if (need_rls_dev)
2177 dev_put(dev);
2178 out:
2179 mutex_unlock(&po->pg_vec_lock);
2180 return err;
2181 }
2182
2183 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2184 size_t reserve, size_t len,
2185 size_t linear, int noblock,
2186 int *err)
2187 {
2188 struct sk_buff *skb;
2189
2190 /* Under a page? Don't bother with paged skb. */
2191 if (prepad + len < PAGE_SIZE || !linear)
2192 linear = len;
2193
2194 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2195 err, 0);
2196 if (!skb)
2197 return NULL;
2198
2199 skb_reserve(skb, reserve);
2200 skb_put(skb, linear);
2201 skb->data_len = len - linear;
2202 skb->len += len - linear;
2203
2204 return skb;
2205 }
2206
2207 static int packet_snd(struct socket *sock,
2208 struct msghdr *msg, size_t len)
2209 {
2210 struct sock *sk = sock->sk;
2211 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2212 struct sk_buff *skb;
2213 struct net_device *dev;
2214 __be16 proto;
2215 bool need_rls_dev = false;
2216 unsigned char *addr;
2217 int err, reserve = 0;
2218 struct virtio_net_hdr vnet_hdr = { 0 };
2219 int offset = 0;
2220 int vnet_hdr_len;
2221 struct packet_sock *po = pkt_sk(sk);
2222 unsigned short gso_type = 0;
2223 int hlen, tlen;
2224 int extra_len = 0;
2225
2226 /*
2227 * Get and verify the address.
2228 */
2229
2230 if (saddr == NULL) {
2231 dev = po->prot_hook.dev;
2232 proto = po->num;
2233 addr = NULL;
2234 } else {
2235 err = -EINVAL;
2236 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2237 goto out;
2238 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2239 goto out;
2240 proto = saddr->sll_protocol;
2241 addr = saddr->sll_addr;
2242 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2243 need_rls_dev = true;
2244 }
2245
2246 err = -ENXIO;
2247 if (dev == NULL)
2248 goto out_unlock;
2249 if (sock->type == SOCK_RAW)
2250 reserve = dev->hard_header_len;
2251
2252 err = -ENETDOWN;
2253 if (!(dev->flags & IFF_UP))
2254 goto out_unlock;
2255
2256 if (po->has_vnet_hdr) {
2257 vnet_hdr_len = sizeof(vnet_hdr);
2258
2259 err = -EINVAL;
2260 if (len < vnet_hdr_len)
2261 goto out_unlock;
2262
2263 len -= vnet_hdr_len;
2264
2265 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2266 vnet_hdr_len);
2267 if (err < 0)
2268 goto out_unlock;
2269
2270 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2271 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2272 vnet_hdr.hdr_len))
2273 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2274 vnet_hdr.csum_offset + 2;
2275
2276 err = -EINVAL;
2277 if (vnet_hdr.hdr_len > len)
2278 goto out_unlock;
2279
2280 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2281 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2282 case VIRTIO_NET_HDR_GSO_TCPV4:
2283 gso_type = SKB_GSO_TCPV4;
2284 break;
2285 case VIRTIO_NET_HDR_GSO_TCPV6:
2286 gso_type = SKB_GSO_TCPV6;
2287 break;
2288 case VIRTIO_NET_HDR_GSO_UDP:
2289 gso_type = SKB_GSO_UDP;
2290 break;
2291 default:
2292 goto out_unlock;
2293 }
2294
2295 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2296 gso_type |= SKB_GSO_TCP_ECN;
2297
2298 if (vnet_hdr.gso_size == 0)
2299 goto out_unlock;
2300
2301 }
2302 }
2303
2304 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2305 if (!netif_supports_nofcs(dev)) {
2306 err = -EPROTONOSUPPORT;
2307 goto out_unlock;
2308 }
2309 extra_len = 4; /* We're doing our own CRC */
2310 }
2311
2312 err = -EMSGSIZE;
2313 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2314 goto out_unlock;
2315
2316 err = -ENOBUFS;
2317 hlen = LL_RESERVED_SPACE(dev);
2318 tlen = dev->needed_tailroom;
2319 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2320 msg->msg_flags & MSG_DONTWAIT, &err);
2321 if (skb == NULL)
2322 goto out_unlock;
2323
2324 skb_set_network_header(skb, reserve);
2325
2326 err = -EINVAL;
2327 if (sock->type == SOCK_DGRAM &&
2328 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2329 goto out_free;
2330
2331 /* Returns -EFAULT on error */
2332 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2333 if (err)
2334 goto out_free;
2335
2336 sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2337
2338 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2339 /* Earlier code assumed this would be a VLAN pkt,
2340 * double-check this now that we have the actual
2341 * packet in hand.
2342 */
2343 struct ethhdr *ehdr;
2344 skb_reset_mac_header(skb);
2345 ehdr = eth_hdr(skb);
2346 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2347 err = -EMSGSIZE;
2348 goto out_free;
2349 }
2350 }
2351
2352 skb->protocol = proto;
2353 skb->dev = dev;
2354 skb->priority = sk->sk_priority;
2355 skb->mark = sk->sk_mark;
2356
2357 if (po->has_vnet_hdr) {
2358 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2359 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2360 vnet_hdr.csum_offset)) {
2361 err = -EINVAL;
2362 goto out_free;
2363 }
2364 }
2365
2366 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2367 skb_shinfo(skb)->gso_type = gso_type;
2368
2369 /* Header must be checked, and gso_segs computed. */
2370 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2371 skb_shinfo(skb)->gso_segs = 0;
2372
2373 len += vnet_hdr_len;
2374 }
2375
2376 skb_probe_transport_header(skb, reserve);
2377
2378 if (unlikely(extra_len == 4))
2379 skb->no_fcs = 1;
2380
2381 /*
2382 * Now send it
2383 */
2384
2385 err = dev_queue_xmit(skb);
2386 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2387 goto out_unlock;
2388
2389 if (need_rls_dev)
2390 dev_put(dev);
2391
2392 return len;
2393
2394 out_free:
2395 kfree_skb(skb);
2396 out_unlock:
2397 if (dev && need_rls_dev)
2398 dev_put(dev);
2399 out:
2400 return err;
2401 }
2402
2403 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2404 struct msghdr *msg, size_t len)
2405 {
2406 struct sock *sk = sock->sk;
2407 struct packet_sock *po = pkt_sk(sk);
2408 if (po->tx_ring.pg_vec)
2409 return tpacket_snd(po, msg);
2410 else
2411 return packet_snd(sock, msg, len);
2412 }
2413
2414 /*
2415 * Close a PACKET socket. This is fairly simple. We immediately go
2416 * to 'closed' state and remove our protocol entry in the device list.
2417 */
2418
2419 static int packet_release(struct socket *sock)
2420 {
2421 struct sock *sk = sock->sk;
2422 struct packet_sock *po;
2423 struct net *net;
2424 union tpacket_req_u req_u;
2425
2426 if (!sk)
2427 return 0;
2428
2429 net = sock_net(sk);
2430 po = pkt_sk(sk);
2431
2432 mutex_lock(&net->packet.sklist_lock);
2433 sk_del_node_init_rcu(sk);
2434 mutex_unlock(&net->packet.sklist_lock);
2435
2436 preempt_disable();
2437 sock_prot_inuse_add(net, sk->sk_prot, -1);
2438 preempt_enable();
2439
2440 spin_lock(&po->bind_lock);
2441 unregister_prot_hook(sk, false);
2442 if (po->prot_hook.dev) {
2443 dev_put(po->prot_hook.dev);
2444 po->prot_hook.dev = NULL;
2445 }
2446 spin_unlock(&po->bind_lock);
2447
2448 packet_flush_mclist(sk);
2449
2450 if (po->rx_ring.pg_vec) {
2451 memset(&req_u, 0, sizeof(req_u));
2452 packet_set_ring(sk, &req_u, 1, 0);
2453 }
2454
2455 if (po->tx_ring.pg_vec) {
2456 memset(&req_u, 0, sizeof(req_u));
2457 packet_set_ring(sk, &req_u, 1, 1);
2458 }
2459
2460 fanout_release(sk);
2461
2462 synchronize_net();
2463 /*
2464 * Now the socket is dead. No more input will appear.
2465 */
2466 sock_orphan(sk);
2467 sock->sk = NULL;
2468
2469 /* Purge queues */
2470
2471 skb_queue_purge(&sk->sk_receive_queue);
2472 sk_refcnt_debug_release(sk);
2473
2474 sock_put(sk);
2475 return 0;
2476 }
2477
2478 /*
2479 * Attach a packet hook.
2480 */
2481
2482 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2483 {
2484 struct packet_sock *po = pkt_sk(sk);
2485
2486 if (po->fanout) {
2487 if (dev)
2488 dev_put(dev);
2489
2490 return -EINVAL;
2491 }
2492
2493 lock_sock(sk);
2494
2495 spin_lock(&po->bind_lock);
2496 unregister_prot_hook(sk, true);
2497 po->num = protocol;
2498 po->prot_hook.type = protocol;
2499 if (po->prot_hook.dev)
2500 dev_put(po->prot_hook.dev);
2501 po->prot_hook.dev = dev;
2502
2503 po->ifindex = dev ? dev->ifindex : 0;
2504
2505 if (protocol == 0)
2506 goto out_unlock;
2507
2508 if (!dev || (dev->flags & IFF_UP)) {
2509 register_prot_hook(sk);
2510 } else {
2511 sk->sk_err = ENETDOWN;
2512 if (!sock_flag(sk, SOCK_DEAD))
2513 sk->sk_error_report(sk);
2514 }
2515
2516 out_unlock:
2517 spin_unlock(&po->bind_lock);
2518 release_sock(sk);
2519 return 0;
2520 }
2521
2522 /*
2523 * Bind a packet socket to a device
2524 */
2525
2526 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2527 int addr_len)
2528 {
2529 struct sock *sk = sock->sk;
2530 char name[15];
2531 struct net_device *dev;
2532 int err = -ENODEV;
2533
2534 /*
2535 * Check legality
2536 */
2537
2538 if (addr_len != sizeof(struct sockaddr))
2539 return -EINVAL;
2540 strlcpy(name, uaddr->sa_data, sizeof(name));
2541
2542 dev = dev_get_by_name(sock_net(sk), name);
2543 if (dev)
2544 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2545 return err;
2546 }
2547
2548 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2549 {
2550 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2551 struct sock *sk = sock->sk;
2552 struct net_device *dev = NULL;
2553 int err;
2554
2555
2556 /*
2557 * Check legality
2558 */
2559
2560 if (addr_len < sizeof(struct sockaddr_ll))
2561 return -EINVAL;
2562 if (sll->sll_family != AF_PACKET)
2563 return -EINVAL;
2564
2565 if (sll->sll_ifindex) {
2566 err = -ENODEV;
2567 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2568 if (dev == NULL)
2569 goto out;
2570 }
2571 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2572
2573 out:
2574 return err;
2575 }
2576
2577 static struct proto packet_proto = {
2578 .name = "PACKET",
2579 .owner = THIS_MODULE,
2580 .obj_size = sizeof(struct packet_sock),
2581 };
2582
2583 /*
2584 * Create a packet of type SOCK_PACKET.
2585 */
2586
2587 static int packet_create(struct net *net, struct socket *sock, int protocol,
2588 int kern)
2589 {
2590 struct sock *sk;
2591 struct packet_sock *po;
2592 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2593 int err;
2594
2595 if (!ns_capable(net->user_ns, CAP_NET_RAW))
2596 return -EPERM;
2597 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2598 sock->type != SOCK_PACKET)
2599 return -ESOCKTNOSUPPORT;
2600
2601 sock->state = SS_UNCONNECTED;
2602
2603 err = -ENOBUFS;
2604 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2605 if (sk == NULL)
2606 goto out;
2607
2608 sock->ops = &packet_ops;
2609 if (sock->type == SOCK_PACKET)
2610 sock->ops = &packet_ops_spkt;
2611
2612 sock_init_data(sock, sk);
2613
2614 po = pkt_sk(sk);
2615 sk->sk_family = PF_PACKET;
2616 po->num = proto;
2617
2618 sk->sk_destruct = packet_sock_destruct;
2619 sk_refcnt_debug_inc(sk);
2620
2621 /*
2622 * Attach a protocol block
2623 */
2624
2625 spin_lock_init(&po->bind_lock);
2626 mutex_init(&po->pg_vec_lock);
2627 po->prot_hook.func = packet_rcv;
2628
2629 if (sock->type == SOCK_PACKET)
2630 po->prot_hook.func = packet_rcv_spkt;
2631
2632 po->prot_hook.af_packet_priv = sk;
2633
2634 if (proto) {
2635 po->prot_hook.type = proto;
2636 register_prot_hook(sk);
2637 }
2638
2639 mutex_lock(&net->packet.sklist_lock);
2640 sk_add_node_rcu(sk, &net->packet.sklist);
2641 mutex_unlock(&net->packet.sklist_lock);
2642
2643 preempt_disable();
2644 sock_prot_inuse_add(net, &packet_proto, 1);
2645 preempt_enable();
2646
2647 return 0;
2648 out:
2649 return err;
2650 }
2651
2652 /*
2653 * Pull a packet from our receive queue and hand it to the user.
2654 * If necessary we block.
2655 */
2656
2657 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2658 struct msghdr *msg, size_t len, int flags)
2659 {
2660 struct sock *sk = sock->sk;
2661 struct sk_buff *skb;
2662 int copied, err;
2663 int vnet_hdr_len = 0;
2664
2665 err = -EINVAL;
2666 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2667 goto out;
2668
2669 #if 0
2670 /* What error should we return now? EUNATTACH? */
2671 if (pkt_sk(sk)->ifindex < 0)
2672 return -ENODEV;
2673 #endif
2674
2675 if (flags & MSG_ERRQUEUE) {
2676 err = sock_recv_errqueue(sk, msg, len,
2677 SOL_PACKET, PACKET_TX_TIMESTAMP);
2678 goto out;
2679 }
2680
2681 /*
2682 * Call the generic datagram receiver. This handles all sorts
2683 * of horrible races and re-entrancy so we can forget about it
2684 * in the protocol layers.
2685 *
2686 * Now it will return ENETDOWN, if device have just gone down,
2687 * but then it will block.
2688 */
2689
2690 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2691
2692 /*
2693 * An error occurred so return it. Because skb_recv_datagram()
2694 * handles the blocking we don't see and worry about blocking
2695 * retries.
2696 */
2697
2698 if (skb == NULL)
2699 goto out;
2700
2701 if (pkt_sk(sk)->has_vnet_hdr) {
2702 struct virtio_net_hdr vnet_hdr = { 0 };
2703
2704 err = -EINVAL;
2705 vnet_hdr_len = sizeof(vnet_hdr);
2706 if (len < vnet_hdr_len)
2707 goto out_free;
2708
2709 len -= vnet_hdr_len;
2710
2711 if (skb_is_gso(skb)) {
2712 struct skb_shared_info *sinfo = skb_shinfo(skb);
2713
2714 /* This is a hint as to how much should be linear. */
2715 vnet_hdr.hdr_len = skb_headlen(skb);
2716 vnet_hdr.gso_size = sinfo->gso_size;
2717 if (sinfo->gso_type & SKB_GSO_TCPV4)
2718 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2719 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2720 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2721 else if (sinfo->gso_type & SKB_GSO_UDP)
2722 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2723 else if (sinfo->gso_type & SKB_GSO_FCOE)
2724 goto out_free;
2725 else
2726 BUG();
2727 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2728 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2729 } else
2730 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2731
2732 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2733 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2734 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2735 vnet_hdr.csum_offset = skb->csum_offset;
2736 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2737 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2738 } /* else everything is zero */
2739
2740 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2741 vnet_hdr_len);
2742 if (err < 0)
2743 goto out_free;
2744 }
2745
2746 /* You lose any data beyond the buffer you gave. If it worries
2747 * a user program they can ask the device for its MTU
2748 * anyway.
2749 */
2750 copied = skb->len;
2751 if (copied > len) {
2752 copied = len;
2753 msg->msg_flags |= MSG_TRUNC;
2754 }
2755
2756 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2757 if (err)
2758 goto out_free;
2759
2760 sock_recv_ts_and_drops(msg, sk, skb);
2761
2762 if (msg->msg_name) {
2763 /* If the address length field is there to be filled
2764 * in, we fill it in now.
2765 */
2766 if (sock->type == SOCK_PACKET) {
2767 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2768 } else {
2769 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
2770 msg->msg_namelen = sll->sll_halen +
2771 offsetof(struct sockaddr_ll, sll_addr);
2772 }
2773 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2774 msg->msg_namelen);
2775 }
2776
2777 if (pkt_sk(sk)->auxdata) {
2778 struct tpacket_auxdata aux;
2779
2780 aux.tp_status = TP_STATUS_USER;
2781 if (skb->ip_summed == CHECKSUM_PARTIAL)
2782 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2783 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2784 aux.tp_snaplen = skb->len;
2785 aux.tp_mac = 0;
2786 aux.tp_net = skb_network_offset(skb);
2787 if (vlan_tx_tag_present(skb)) {
2788 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2789 aux.tp_status |= TP_STATUS_VLAN_VALID;
2790 } else {
2791 aux.tp_vlan_tci = 0;
2792 }
2793 aux.tp_padding = 0;
2794 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2795 }
2796
2797 /*
2798 * Free or return the buffer as appropriate. Again this
2799 * hides all the races and re-entrancy issues from us.
2800 */
2801 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2802
2803 out_free:
2804 skb_free_datagram(sk, skb);
2805 out:
2806 return err;
2807 }
2808
2809 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2810 int *uaddr_len, int peer)
2811 {
2812 struct net_device *dev;
2813 struct sock *sk = sock->sk;
2814
2815 if (peer)
2816 return -EOPNOTSUPP;
2817
2818 uaddr->sa_family = AF_PACKET;
2819 memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
2820 rcu_read_lock();
2821 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2822 if (dev)
2823 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
2824 rcu_read_unlock();
2825 *uaddr_len = sizeof(*uaddr);
2826
2827 return 0;
2828 }
2829
2830 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2831 int *uaddr_len, int peer)
2832 {
2833 struct net_device *dev;
2834 struct sock *sk = sock->sk;
2835 struct packet_sock *po = pkt_sk(sk);
2836 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2837
2838 if (peer)
2839 return -EOPNOTSUPP;
2840
2841 sll->sll_family = AF_PACKET;
2842 sll->sll_ifindex = po->ifindex;
2843 sll->sll_protocol = po->num;
2844 sll->sll_pkttype = 0;
2845 rcu_read_lock();
2846 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2847 if (dev) {
2848 sll->sll_hatype = dev->type;
2849 sll->sll_halen = dev->addr_len;
2850 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2851 } else {
2852 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2853 sll->sll_halen = 0;
2854 }
2855 rcu_read_unlock();
2856 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2857
2858 return 0;
2859 }
2860
2861 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2862 int what)
2863 {
2864 switch (i->type) {
2865 case PACKET_MR_MULTICAST:
2866 if (i->alen != dev->addr_len)
2867 return -EINVAL;
2868 if (what > 0)
2869 return dev_mc_add(dev, i->addr);
2870 else
2871 return dev_mc_del(dev, i->addr);
2872 break;
2873 case PACKET_MR_PROMISC:
2874 return dev_set_promiscuity(dev, what);
2875 break;
2876 case PACKET_MR_ALLMULTI:
2877 return dev_set_allmulti(dev, what);
2878 break;
2879 case PACKET_MR_UNICAST:
2880 if (i->alen != dev->addr_len)
2881 return -EINVAL;
2882 if (what > 0)
2883 return dev_uc_add(dev, i->addr);
2884 else
2885 return dev_uc_del(dev, i->addr);
2886 break;
2887 default:
2888 break;
2889 }
2890 return 0;
2891 }
2892
2893 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2894 {
2895 for ( ; i; i = i->next) {
2896 if (i->ifindex == dev->ifindex)
2897 packet_dev_mc(dev, i, what);
2898 }
2899 }
2900
2901 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2902 {
2903 struct packet_sock *po = pkt_sk(sk);
2904 struct packet_mclist *ml, *i;
2905 struct net_device *dev;
2906 int err;
2907
2908 rtnl_lock();
2909
2910 err = -ENODEV;
2911 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2912 if (!dev)
2913 goto done;
2914
2915 err = -EINVAL;
2916 if (mreq->mr_alen > dev->addr_len)
2917 goto done;
2918
2919 err = -ENOBUFS;
2920 i = kmalloc(sizeof(*i), GFP_KERNEL);
2921 if (i == NULL)
2922 goto done;
2923
2924 err = 0;
2925 for (ml = po->mclist; ml; ml = ml->next) {
2926 if (ml->ifindex == mreq->mr_ifindex &&
2927 ml->type == mreq->mr_type &&
2928 ml->alen == mreq->mr_alen &&
2929 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2930 ml->count++;
2931 /* Free the new element ... */
2932 kfree(i);
2933 goto done;
2934 }
2935 }
2936
2937 i->type = mreq->mr_type;
2938 i->ifindex = mreq->mr_ifindex;
2939 i->alen = mreq->mr_alen;
2940 memcpy(i->addr, mreq->mr_address, i->alen);
2941 i->count = 1;
2942 i->next = po->mclist;
2943 po->mclist = i;
2944 err = packet_dev_mc(dev, i, 1);
2945 if (err) {
2946 po->mclist = i->next;
2947 kfree(i);
2948 }
2949
2950 done:
2951 rtnl_unlock();
2952 return err;
2953 }
2954
2955 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2956 {
2957 struct packet_mclist *ml, **mlp;
2958
2959 rtnl_lock();
2960
2961 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2962 if (ml->ifindex == mreq->mr_ifindex &&
2963 ml->type == mreq->mr_type &&
2964 ml->alen == mreq->mr_alen &&
2965 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2966 if (--ml->count == 0) {
2967 struct net_device *dev;
2968 *mlp = ml->next;
2969 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2970 if (dev)
2971 packet_dev_mc(dev, ml, -1);
2972 kfree(ml);
2973 }
2974 rtnl_unlock();
2975 return 0;
2976 }
2977 }
2978 rtnl_unlock();
2979 return -EADDRNOTAVAIL;
2980 }
2981
2982 static void packet_flush_mclist(struct sock *sk)
2983 {
2984 struct packet_sock *po = pkt_sk(sk);
2985 struct packet_mclist *ml;
2986
2987 if (!po->mclist)
2988 return;
2989
2990 rtnl_lock();
2991 while ((ml = po->mclist) != NULL) {
2992 struct net_device *dev;
2993
2994 po->mclist = ml->next;
2995 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2996 if (dev != NULL)
2997 packet_dev_mc(dev, ml, -1);
2998 kfree(ml);
2999 }
3000 rtnl_unlock();
3001 }
3002
3003 static int
3004 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3005 {
3006 struct sock *sk = sock->sk;
3007 struct packet_sock *po = pkt_sk(sk);
3008 int ret;
3009
3010 if (level != SOL_PACKET)
3011 return -ENOPROTOOPT;
3012
3013 switch (optname) {
3014 case PACKET_ADD_MEMBERSHIP:
3015 case PACKET_DROP_MEMBERSHIP:
3016 {
3017 struct packet_mreq_max mreq;
3018 int len = optlen;
3019 memset(&mreq, 0, sizeof(mreq));
3020 if (len < sizeof(struct packet_mreq))
3021 return -EINVAL;
3022 if (len > sizeof(mreq))
3023 len = sizeof(mreq);
3024 if (copy_from_user(&mreq, optval, len))
3025 return -EFAULT;
3026 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3027 return -EINVAL;
3028 if (optname == PACKET_ADD_MEMBERSHIP)
3029 ret = packet_mc_add(sk, &mreq);
3030 else
3031 ret = packet_mc_drop(sk, &mreq);
3032 return ret;
3033 }
3034
3035 case PACKET_RX_RING:
3036 case PACKET_TX_RING:
3037 {
3038 union tpacket_req_u req_u;
3039 int len;
3040
3041 switch (po->tp_version) {
3042 case TPACKET_V1:
3043 case TPACKET_V2:
3044 len = sizeof(req_u.req);
3045 break;
3046 case TPACKET_V3:
3047 default:
3048 len = sizeof(req_u.req3);
3049 break;
3050 }
3051 if (optlen < len)
3052 return -EINVAL;
3053 if (pkt_sk(sk)->has_vnet_hdr)
3054 return -EINVAL;
3055 if (copy_from_user(&req_u.req, optval, len))
3056 return -EFAULT;
3057 return packet_set_ring(sk, &req_u, 0,
3058 optname == PACKET_TX_RING);
3059 }
3060 case PACKET_COPY_THRESH:
3061 {
3062 int val;
3063
3064 if (optlen != sizeof(val))
3065 return -EINVAL;
3066 if (copy_from_user(&val, optval, sizeof(val)))
3067 return -EFAULT;
3068
3069 pkt_sk(sk)->copy_thresh = val;
3070 return 0;
3071 }
3072 case PACKET_VERSION:
3073 {
3074 int val;
3075
3076 if (optlen != sizeof(val))
3077 return -EINVAL;
3078 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3079 return -EBUSY;
3080 if (copy_from_user(&val, optval, sizeof(val)))
3081 return -EFAULT;
3082 switch (val) {
3083 case TPACKET_V1:
3084 case TPACKET_V2:
3085 case TPACKET_V3:
3086 po->tp_version = val;
3087 return 0;
3088 default:
3089 return -EINVAL;
3090 }
3091 }
3092 case PACKET_RESERVE:
3093 {
3094 unsigned int val;
3095
3096 if (optlen != sizeof(val))
3097 return -EINVAL;
3098 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3099 return -EBUSY;
3100 if (copy_from_user(&val, optval, sizeof(val)))
3101 return -EFAULT;
3102 po->tp_reserve = val;
3103 return 0;
3104 }
3105 case PACKET_LOSS:
3106 {
3107 unsigned int val;
3108
3109 if (optlen != sizeof(val))
3110 return -EINVAL;
3111 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3112 return -EBUSY;
3113 if (copy_from_user(&val, optval, sizeof(val)))
3114 return -EFAULT;
3115 po->tp_loss = !!val;
3116 return 0;
3117 }
3118 case PACKET_AUXDATA:
3119 {
3120 int val;
3121
3122 if (optlen < sizeof(val))
3123 return -EINVAL;
3124 if (copy_from_user(&val, optval, sizeof(val)))
3125 return -EFAULT;
3126
3127 po->auxdata = !!val;
3128 return 0;
3129 }
3130 case PACKET_ORIGDEV:
3131 {
3132 int val;
3133
3134 if (optlen < sizeof(val))
3135 return -EINVAL;
3136 if (copy_from_user(&val, optval, sizeof(val)))
3137 return -EFAULT;
3138
3139 po->origdev = !!val;
3140 return 0;
3141 }
3142 case PACKET_VNET_HDR:
3143 {
3144 int val;
3145
3146 if (sock->type != SOCK_RAW)
3147 return -EINVAL;
3148 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3149 return -EBUSY;
3150 if (optlen < sizeof(val))
3151 return -EINVAL;
3152 if (copy_from_user(&val, optval, sizeof(val)))
3153 return -EFAULT;
3154
3155 po->has_vnet_hdr = !!val;
3156 return 0;
3157 }
3158 case PACKET_TIMESTAMP:
3159 {
3160 int val;
3161
3162 if (optlen != sizeof(val))
3163 return -EINVAL;
3164 if (copy_from_user(&val, optval, sizeof(val)))
3165 return -EFAULT;
3166
3167 po->tp_tstamp = val;
3168 return 0;
3169 }
3170 case PACKET_FANOUT:
3171 {
3172 int val;
3173
3174 if (optlen != sizeof(val))
3175 return -EINVAL;
3176 if (copy_from_user(&val, optval, sizeof(val)))
3177 return -EFAULT;
3178
3179 return fanout_add(sk, val & 0xffff, val >> 16);
3180 }
3181 case PACKET_TX_HAS_OFF:
3182 {
3183 unsigned int val;
3184
3185 if (optlen != sizeof(val))
3186 return -EINVAL;
3187 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3188 return -EBUSY;
3189 if (copy_from_user(&val, optval, sizeof(val)))
3190 return -EFAULT;
3191 po->tp_tx_has_off = !!val;
3192 return 0;
3193 }
3194 default:
3195 return -ENOPROTOOPT;
3196 }
3197 }
3198
3199 static int packet_getsockopt(struct socket *sock, int level, int optname,
3200 char __user *optval, int __user *optlen)
3201 {
3202 int len;
3203 int val, lv = sizeof(val);
3204 struct sock *sk = sock->sk;
3205 struct packet_sock *po = pkt_sk(sk);
3206 void *data = &val;
3207 union tpacket_stats_u st;
3208
3209 if (level != SOL_PACKET)
3210 return -ENOPROTOOPT;
3211
3212 if (get_user(len, optlen))
3213 return -EFAULT;
3214
3215 if (len < 0)
3216 return -EINVAL;
3217
3218 switch (optname) {
3219 case PACKET_STATISTICS:
3220 spin_lock_bh(&sk->sk_receive_queue.lock);
3221 memcpy(&st, &po->stats, sizeof(st));
3222 memset(&po->stats, 0, sizeof(po->stats));
3223 spin_unlock_bh(&sk->sk_receive_queue.lock);
3224
3225 if (po->tp_version == TPACKET_V3) {
3226 lv = sizeof(struct tpacket_stats_v3);
3227 st.stats3.tp_packets += st.stats3.tp_drops;
3228 data = &st.stats3;
3229 } else {
3230 lv = sizeof(struct tpacket_stats);
3231 st.stats1.tp_packets += st.stats1.tp_drops;
3232 data = &st.stats1;
3233 }
3234
3235 break;
3236 case PACKET_AUXDATA:
3237 val = po->auxdata;
3238 break;
3239 case PACKET_ORIGDEV:
3240 val = po->origdev;
3241 break;
3242 case PACKET_VNET_HDR:
3243 val = po->has_vnet_hdr;
3244 break;
3245 case PACKET_VERSION:
3246 val = po->tp_version;
3247 break;
3248 case PACKET_HDRLEN:
3249 if (len > sizeof(int))
3250 len = sizeof(int);
3251 if (copy_from_user(&val, optval, len))
3252 return -EFAULT;
3253 switch (val) {
3254 case TPACKET_V1:
3255 val = sizeof(struct tpacket_hdr);
3256 break;
3257 case TPACKET_V2:
3258 val = sizeof(struct tpacket2_hdr);
3259 break;
3260 case TPACKET_V3:
3261 val = sizeof(struct tpacket3_hdr);
3262 break;
3263 default:
3264 return -EINVAL;
3265 }
3266 break;
3267 case PACKET_RESERVE:
3268 val = po->tp_reserve;
3269 break;
3270 case PACKET_LOSS:
3271 val = po->tp_loss;
3272 break;
3273 case PACKET_TIMESTAMP:
3274 val = po->tp_tstamp;
3275 break;
3276 case PACKET_FANOUT:
3277 val = (po->fanout ?
3278 ((u32)po->fanout->id |
3279 ((u32)po->fanout->type << 16) |
3280 ((u32)po->fanout->flags << 24)) :
3281 0);
3282 break;
3283 case PACKET_TX_HAS_OFF:
3284 val = po->tp_tx_has_off;
3285 break;
3286 default:
3287 return -ENOPROTOOPT;
3288 }
3289
3290 if (len > lv)
3291 len = lv;
3292 if (put_user(len, optlen))
3293 return -EFAULT;
3294 if (copy_to_user(optval, data, len))
3295 return -EFAULT;
3296 return 0;
3297 }
3298
3299
3300 static int packet_notifier(struct notifier_block *this,
3301 unsigned long msg, void *ptr)
3302 {
3303 struct sock *sk;
3304 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3305 struct net *net = dev_net(dev);
3306
3307 rcu_read_lock();
3308 sk_for_each_rcu(sk, &net->packet.sklist) {
3309 struct packet_sock *po = pkt_sk(sk);
3310
3311 switch (msg) {
3312 case NETDEV_UNREGISTER:
3313 if (po->mclist)
3314 packet_dev_mclist(dev, po->mclist, -1);
3315 /* fallthrough */
3316
3317 case NETDEV_DOWN:
3318 if (dev->ifindex == po->ifindex) {
3319 spin_lock(&po->bind_lock);
3320 if (po->running) {
3321 __unregister_prot_hook(sk, false);
3322 sk->sk_err = ENETDOWN;
3323 if (!sock_flag(sk, SOCK_DEAD))
3324 sk->sk_error_report(sk);
3325 }
3326 if (msg == NETDEV_UNREGISTER) {
3327 po->ifindex = -1;
3328 if (po->prot_hook.dev)
3329 dev_put(po->prot_hook.dev);
3330 po->prot_hook.dev = NULL;
3331 }
3332 spin_unlock(&po->bind_lock);
3333 }
3334 break;
3335 case NETDEV_UP:
3336 if (dev->ifindex == po->ifindex) {
3337 spin_lock(&po->bind_lock);
3338 if (po->num)
3339 register_prot_hook(sk);
3340 spin_unlock(&po->bind_lock);
3341 }
3342 break;
3343 }
3344 }
3345 rcu_read_unlock();
3346 return NOTIFY_DONE;
3347 }
3348
3349
3350 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3351 unsigned long arg)
3352 {
3353 struct sock *sk = sock->sk;
3354
3355 switch (cmd) {
3356 case SIOCOUTQ:
3357 {
3358 int amount = sk_wmem_alloc_get(sk);
3359
3360 return put_user(amount, (int __user *)arg);
3361 }
3362 case SIOCINQ:
3363 {
3364 struct sk_buff *skb;
3365 int amount = 0;
3366
3367 spin_lock_bh(&sk->sk_receive_queue.lock);
3368 skb = skb_peek(&sk->sk_receive_queue);
3369 if (skb)
3370 amount = skb->len;
3371 spin_unlock_bh(&sk->sk_receive_queue.lock);
3372 return put_user(amount, (int __user *)arg);
3373 }
3374 case SIOCGSTAMP:
3375 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3376 case SIOCGSTAMPNS:
3377 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3378
3379 #ifdef CONFIG_INET
3380 case SIOCADDRT:
3381 case SIOCDELRT:
3382 case SIOCDARP:
3383 case SIOCGARP:
3384 case SIOCSARP:
3385 case SIOCGIFADDR:
3386 case SIOCSIFADDR:
3387 case SIOCGIFBRDADDR:
3388 case SIOCSIFBRDADDR:
3389 case SIOCGIFNETMASK:
3390 case SIOCSIFNETMASK:
3391 case SIOCGIFDSTADDR:
3392 case SIOCSIFDSTADDR:
3393 case SIOCSIFFLAGS:
3394 return inet_dgram_ops.ioctl(sock, cmd, arg);
3395 #endif
3396
3397 default:
3398 return -ENOIOCTLCMD;
3399 }
3400 return 0;
3401 }
3402
3403 static unsigned int packet_poll(struct file *file, struct socket *sock,
3404 poll_table *wait)
3405 {
3406 struct sock *sk = sock->sk;
3407 struct packet_sock *po = pkt_sk(sk);
3408 unsigned int mask = datagram_poll(file, sock, wait);
3409
3410 spin_lock_bh(&sk->sk_receive_queue.lock);
3411 if (po->rx_ring.pg_vec) {
3412 if (!packet_previous_rx_frame(po, &po->rx_ring,
3413 TP_STATUS_KERNEL))
3414 mask |= POLLIN | POLLRDNORM;
3415 }
3416 spin_unlock_bh(&sk->sk_receive_queue.lock);
3417 spin_lock_bh(&sk->sk_write_queue.lock);
3418 if (po->tx_ring.pg_vec) {
3419 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3420 mask |= POLLOUT | POLLWRNORM;
3421 }
3422 spin_unlock_bh(&sk->sk_write_queue.lock);
3423 return mask;
3424 }
3425
3426
3427 /* Dirty? Well, I still did not learn better way to account
3428 * for user mmaps.
3429 */
3430
3431 static void packet_mm_open(struct vm_area_struct *vma)
3432 {
3433 struct file *file = vma->vm_file;
3434 struct socket *sock = file->private_data;
3435 struct sock *sk = sock->sk;
3436
3437 if (sk)
3438 atomic_inc(&pkt_sk(sk)->mapped);
3439 }
3440
3441 static void packet_mm_close(struct vm_area_struct *vma)
3442 {
3443 struct file *file = vma->vm_file;
3444 struct socket *sock = file->private_data;
3445 struct sock *sk = sock->sk;
3446
3447 if (sk)
3448 atomic_dec(&pkt_sk(sk)->mapped);
3449 }
3450
3451 static const struct vm_operations_struct packet_mmap_ops = {
3452 .open = packet_mm_open,
3453 .close = packet_mm_close,
3454 };
3455
3456 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3457 unsigned int len)
3458 {
3459 int i;
3460
3461 for (i = 0; i < len; i++) {
3462 if (likely(pg_vec[i].buffer)) {
3463 if (is_vmalloc_addr(pg_vec[i].buffer))
3464 vfree(pg_vec[i].buffer);
3465 else
3466 free_pages((unsigned long)pg_vec[i].buffer,
3467 order);
3468 pg_vec[i].buffer = NULL;
3469 }
3470 }
3471 kfree(pg_vec);
3472 }
3473
3474 static char *alloc_one_pg_vec_page(unsigned long order)
3475 {
3476 char *buffer = NULL;
3477 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3478 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3479
3480 buffer = (char *) __get_free_pages(gfp_flags, order);
3481
3482 if (buffer)
3483 return buffer;
3484
3485 /*
3486 * __get_free_pages failed, fall back to vmalloc
3487 */
3488 buffer = vzalloc((1 << order) * PAGE_SIZE);
3489
3490 if (buffer)
3491 return buffer;
3492
3493 /*
3494 * vmalloc failed, lets dig into swap here
3495 */
3496 gfp_flags &= ~__GFP_NORETRY;
3497 buffer = (char *)__get_free_pages(gfp_flags, order);
3498 if (buffer)
3499 return buffer;
3500
3501 /*
3502 * complete and utter failure
3503 */
3504 return NULL;
3505 }
3506
3507 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3508 {
3509 unsigned int block_nr = req->tp_block_nr;
3510 struct pgv *pg_vec;
3511 int i;
3512
3513 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3514 if (unlikely(!pg_vec))
3515 goto out;
3516
3517 for (i = 0; i < block_nr; i++) {
3518 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3519 if (unlikely(!pg_vec[i].buffer))
3520 goto out_free_pgvec;
3521 }
3522
3523 out:
3524 return pg_vec;
3525
3526 out_free_pgvec:
3527 free_pg_vec(pg_vec, order, block_nr);
3528 pg_vec = NULL;
3529 goto out;
3530 }
3531
3532 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3533 int closing, int tx_ring)
3534 {
3535 struct pgv *pg_vec = NULL;
3536 struct packet_sock *po = pkt_sk(sk);
3537 int was_running, order = 0;
3538 struct packet_ring_buffer *rb;
3539 struct sk_buff_head *rb_queue;
3540 __be16 num;
3541 int err = -EINVAL;
3542 /* Added to avoid minimal code churn */
3543 struct tpacket_req *req = &req_u->req;
3544
3545 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3546 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3547 WARN(1, "Tx-ring is not supported.\n");
3548 goto out;
3549 }
3550
3551 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3552 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3553
3554 err = -EBUSY;
3555 if (!closing) {
3556 if (atomic_read(&po->mapped))
3557 goto out;
3558 if (atomic_read(&rb->pending))
3559 goto out;
3560 }
3561
3562 if (req->tp_block_nr) {
3563 /* Sanity tests and some calculations */
3564 err = -EBUSY;
3565 if (unlikely(rb->pg_vec))
3566 goto out;
3567
3568 switch (po->tp_version) {
3569 case TPACKET_V1:
3570 po->tp_hdrlen = TPACKET_HDRLEN;
3571 break;
3572 case TPACKET_V2:
3573 po->tp_hdrlen = TPACKET2_HDRLEN;
3574 break;
3575 case TPACKET_V3:
3576 po->tp_hdrlen = TPACKET3_HDRLEN;
3577 break;
3578 }
3579
3580 err = -EINVAL;
3581 if (unlikely((int)req->tp_block_size <= 0))
3582 goto out;
3583 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3584 goto out;
3585 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3586 po->tp_reserve))
3587 goto out;
3588 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3589 goto out;
3590
3591 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3592 if (unlikely(rb->frames_per_block <= 0))
3593 goto out;
3594 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3595 req->tp_frame_nr))
3596 goto out;
3597
3598 err = -ENOMEM;
3599 order = get_order(req->tp_block_size);
3600 pg_vec = alloc_pg_vec(req, order);
3601 if (unlikely(!pg_vec))
3602 goto out;
3603 switch (po->tp_version) {
3604 case TPACKET_V3:
3605 /* Transmit path is not supported. We checked
3606 * it above but just being paranoid
3607 */
3608 if (!tx_ring)
3609 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3610 break;
3611 default:
3612 break;
3613 }
3614 }
3615 /* Done */
3616 else {
3617 err = -EINVAL;
3618 if (unlikely(req->tp_frame_nr))
3619 goto out;
3620 }
3621
3622 lock_sock(sk);
3623
3624 /* Detach socket from network */
3625 spin_lock(&po->bind_lock);
3626 was_running = po->running;
3627 num = po->num;
3628 if (was_running) {
3629 po->num = 0;
3630 __unregister_prot_hook(sk, false);
3631 }
3632 spin_unlock(&po->bind_lock);
3633
3634 synchronize_net();
3635
3636 err = -EBUSY;
3637 mutex_lock(&po->pg_vec_lock);
3638 if (closing || atomic_read(&po->mapped) == 0) {
3639 err = 0;
3640 spin_lock_bh(&rb_queue->lock);
3641 swap(rb->pg_vec, pg_vec);
3642 rb->frame_max = (req->tp_frame_nr - 1);
3643 rb->head = 0;
3644 rb->frame_size = req->tp_frame_size;
3645 spin_unlock_bh(&rb_queue->lock);
3646
3647 swap(rb->pg_vec_order, order);
3648 swap(rb->pg_vec_len, req->tp_block_nr);
3649
3650 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3651 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3652 tpacket_rcv : packet_rcv;
3653 skb_queue_purge(rb_queue);
3654 if (atomic_read(&po->mapped))
3655 pr_err("packet_mmap: vma is busy: %d\n",
3656 atomic_read(&po->mapped));
3657 }
3658 mutex_unlock(&po->pg_vec_lock);
3659
3660 spin_lock(&po->bind_lock);
3661 if (was_running) {
3662 po->num = num;
3663 register_prot_hook(sk);
3664 }
3665 spin_unlock(&po->bind_lock);
3666 if (closing && (po->tp_version > TPACKET_V2)) {
3667 /* Because we don't support block-based V3 on tx-ring */
3668 if (!tx_ring)
3669 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3670 }
3671 release_sock(sk);
3672
3673 if (pg_vec)
3674 free_pg_vec(pg_vec, order, req->tp_block_nr);
3675 out:
3676 return err;
3677 }
3678
3679 static int packet_mmap(struct file *file, struct socket *sock,
3680 struct vm_area_struct *vma)
3681 {
3682 struct sock *sk = sock->sk;
3683 struct packet_sock *po = pkt_sk(sk);
3684 unsigned long size, expected_size;
3685 struct packet_ring_buffer *rb;
3686 unsigned long start;
3687 int err = -EINVAL;
3688 int i;
3689
3690 if (vma->vm_pgoff)
3691 return -EINVAL;
3692
3693 mutex_lock(&po->pg_vec_lock);
3694
3695 expected_size = 0;
3696 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3697 if (rb->pg_vec) {
3698 expected_size += rb->pg_vec_len
3699 * rb->pg_vec_pages
3700 * PAGE_SIZE;
3701 }
3702 }
3703
3704 if (expected_size == 0)
3705 goto out;
3706
3707 size = vma->vm_end - vma->vm_start;
3708 if (size != expected_size)
3709 goto out;
3710
3711 start = vma->vm_start;
3712 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3713 if (rb->pg_vec == NULL)
3714 continue;
3715
3716 for (i = 0; i < rb->pg_vec_len; i++) {
3717 struct page *page;
3718 void *kaddr = rb->pg_vec[i].buffer;
3719 int pg_num;
3720
3721 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3722 page = pgv_to_page(kaddr);
3723 err = vm_insert_page(vma, start, page);
3724 if (unlikely(err))
3725 goto out;
3726 start += PAGE_SIZE;
3727 kaddr += PAGE_SIZE;
3728 }
3729 }
3730 }
3731
3732 atomic_inc(&po->mapped);
3733 vma->vm_ops = &packet_mmap_ops;
3734 err = 0;
3735
3736 out:
3737 mutex_unlock(&po->pg_vec_lock);
3738 return err;
3739 }
3740
3741 static const struct proto_ops packet_ops_spkt = {
3742 .family = PF_PACKET,
3743 .owner = THIS_MODULE,
3744 .release = packet_release,
3745 .bind = packet_bind_spkt,
3746 .connect = sock_no_connect,
3747 .socketpair = sock_no_socketpair,
3748 .accept = sock_no_accept,
3749 .getname = packet_getname_spkt,
3750 .poll = datagram_poll,
3751 .ioctl = packet_ioctl,
3752 .listen = sock_no_listen,
3753 .shutdown = sock_no_shutdown,
3754 .setsockopt = sock_no_setsockopt,
3755 .getsockopt = sock_no_getsockopt,
3756 .sendmsg = packet_sendmsg_spkt,
3757 .recvmsg = packet_recvmsg,
3758 .mmap = sock_no_mmap,
3759 .sendpage = sock_no_sendpage,
3760 };
3761
3762 static const struct proto_ops packet_ops = {
3763 .family = PF_PACKET,
3764 .owner = THIS_MODULE,
3765 .release = packet_release,
3766 .bind = packet_bind,
3767 .connect = sock_no_connect,
3768 .socketpair = sock_no_socketpair,
3769 .accept = sock_no_accept,
3770 .getname = packet_getname,
3771 .poll = packet_poll,
3772 .ioctl = packet_ioctl,
3773 .listen = sock_no_listen,
3774 .shutdown = sock_no_shutdown,
3775 .setsockopt = packet_setsockopt,
3776 .getsockopt = packet_getsockopt,
3777 .sendmsg = packet_sendmsg,
3778 .recvmsg = packet_recvmsg,
3779 .mmap = packet_mmap,
3780 .sendpage = sock_no_sendpage,
3781 };
3782
3783 static const struct net_proto_family packet_family_ops = {
3784 .family = PF_PACKET,
3785 .create = packet_create,
3786 .owner = THIS_MODULE,
3787 };
3788
3789 static struct notifier_block packet_netdev_notifier = {
3790 .notifier_call = packet_notifier,
3791 };
3792
3793 #ifdef CONFIG_PROC_FS
3794
3795 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3796 __acquires(RCU)
3797 {
3798 struct net *net = seq_file_net(seq);
3799
3800 rcu_read_lock();
3801 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3802 }
3803
3804 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3805 {
3806 struct net *net = seq_file_net(seq);
3807 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3808 }
3809
3810 static void packet_seq_stop(struct seq_file *seq, void *v)
3811 __releases(RCU)
3812 {
3813 rcu_read_unlock();
3814 }
3815
3816 static int packet_seq_show(struct seq_file *seq, void *v)
3817 {
3818 if (v == SEQ_START_TOKEN)
3819 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3820 else {
3821 struct sock *s = sk_entry(v);
3822 const struct packet_sock *po = pkt_sk(s);
3823
3824 seq_printf(seq,
3825 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3826 s,
3827 atomic_read(&s->sk_refcnt),
3828 s->sk_type,
3829 ntohs(po->num),
3830 po->ifindex,
3831 po->running,
3832 atomic_read(&s->sk_rmem_alloc),
3833 from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3834 sock_i_ino(s));
3835 }
3836
3837 return 0;
3838 }
3839
3840 static const struct seq_operations packet_seq_ops = {
3841 .start = packet_seq_start,
3842 .next = packet_seq_next,
3843 .stop = packet_seq_stop,
3844 .show = packet_seq_show,
3845 };
3846
3847 static int packet_seq_open(struct inode *inode, struct file *file)
3848 {
3849 return seq_open_net(inode, file, &packet_seq_ops,
3850 sizeof(struct seq_net_private));
3851 }
3852
3853 static const struct file_operations packet_seq_fops = {
3854 .owner = THIS_MODULE,
3855 .open = packet_seq_open,
3856 .read = seq_read,
3857 .llseek = seq_lseek,
3858 .release = seq_release_net,
3859 };
3860
3861 #endif
3862
3863 static int __net_init packet_net_init(struct net *net)
3864 {
3865 mutex_init(&net->packet.sklist_lock);
3866 INIT_HLIST_HEAD(&net->packet.sklist);
3867
3868 if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
3869 return -ENOMEM;
3870
3871 return 0;
3872 }
3873
3874 static void __net_exit packet_net_exit(struct net *net)
3875 {
3876 remove_proc_entry("packet", net->proc_net);
3877 }
3878
3879 static struct pernet_operations packet_net_ops = {
3880 .init = packet_net_init,
3881 .exit = packet_net_exit,
3882 };
3883
3884
3885 static void __exit packet_exit(void)
3886 {
3887 unregister_netdevice_notifier(&packet_netdev_notifier);
3888 unregister_pernet_subsys(&packet_net_ops);
3889 sock_unregister(PF_PACKET);
3890 proto_unregister(&packet_proto);
3891 }
3892
3893 static int __init packet_init(void)
3894 {
3895 int rc = proto_register(&packet_proto, 0);
3896
3897 if (rc != 0)
3898 goto out;
3899
3900 sock_register(&packet_family_ops);
3901 register_pernet_subsys(&packet_net_ops);
3902 register_netdevice_notifier(&packet_netdev_notifier);
3903 out:
3904 return rc;
3905 }
3906
3907 module_init(packet_init);
3908 module_exit(packet_exit);
3909 MODULE_LICENSE("GPL");
3910 MODULE_ALIAS_NETPROTO(PF_PACKET);
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