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packet: Report rings cfg via diag engine
[deliverable/linux.git] / net / packet / af_packet.c
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1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PACKET - implements raw packet sockets.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 *
12 * Fixes:
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
41 * and packet_mreq.
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
44 * layer.
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
46 *
47 *
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
52 *
53 */
54
55#include <linux/types.h>
56#include <linux/mm.h>
57#include <linux/capability.h>
58#include <linux/fcntl.h>
59#include <linux/socket.h>
60#include <linux/in.h>
61#include <linux/inet.h>
62#include <linux/netdevice.h>
63#include <linux/if_packet.h>
64#include <linux/wireless.h>
65#include <linux/kernel.h>
66#include <linux/kmod.h>
67#include <linux/slab.h>
68#include <linux/vmalloc.h>
69#include <net/net_namespace.h>
70#include <net/ip.h>
71#include <net/protocol.h>
72#include <linux/skbuff.h>
73#include <net/sock.h>
74#include <linux/errno.h>
75#include <linux/timer.h>
76#include <asm/uaccess.h>
77#include <asm/ioctls.h>
78#include <asm/page.h>
79#include <asm/cacheflush.h>
80#include <asm/io.h>
81#include <linux/proc_fs.h>
82#include <linux/seq_file.h>
83#include <linux/poll.h>
84#include <linux/module.h>
85#include <linux/init.h>
86#include <linux/mutex.h>
87#include <linux/if_vlan.h>
88#include <linux/virtio_net.h>
89#include <linux/errqueue.h>
90#include <linux/net_tstamp.h>
91
92#ifdef CONFIG_INET
93#include <net/inet_common.h>
94#endif
95
96#include "internal.h"
97
98/*
99 Assumptions:
100 - if device has no dev->hard_header routine, it adds and removes ll header
101 inside itself. In this case ll header is invisible outside of device,
102 but higher levels still should reserve dev->hard_header_len.
103 Some devices are enough clever to reallocate skb, when header
104 will not fit to reserved space (tunnel), another ones are silly
105 (PPP).
106 - packet socket receives packets with pulled ll header,
107 so that SOCK_RAW should push it back.
108
109On receive:
110-----------
111
112Incoming, dev->hard_header!=NULL
113 mac_header -> ll header
114 data -> data
115
116Outgoing, dev->hard_header!=NULL
117 mac_header -> ll header
118 data -> ll header
119
120Incoming, 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
126Outgoing, dev->hard_header==NULL
127 mac_header -> data. ll header is still not built!
128 data -> data
129
130Resume
131 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
132
133
134On transmit:
135------------
136
137dev->hard_header != NULL
138 mac_header -> ll header
139 data -> ll header
140
141dev->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 */
154struct 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
161static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
162 int closing, int tx_ring);
163
164
165#define V3_ALIGNMENT (8)
166
167#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
168
169#define BLK_PLUS_PRIV(sz_of_priv) \
170 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
171
172#define PGV_FROM_VMALLOC 1
173
174#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
175#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
176#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
177#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
178#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
179#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
180#define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
181
182struct packet_sock;
183static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
184
185static void *packet_previous_frame(struct packet_sock *po,
186 struct packet_ring_buffer *rb,
187 int status);
188static void packet_increment_head(struct packet_ring_buffer *buff);
189static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
190 struct tpacket_block_desc *);
191static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
192 struct packet_sock *);
193static void prb_retire_current_block(struct tpacket_kbdq_core *,
194 struct packet_sock *, unsigned int status);
195static int prb_queue_frozen(struct tpacket_kbdq_core *);
196static void prb_open_block(struct tpacket_kbdq_core *,
197 struct tpacket_block_desc *);
198static void prb_retire_rx_blk_timer_expired(unsigned long);
199static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
200static void prb_init_blk_timer(struct packet_sock *,
201 struct tpacket_kbdq_core *,
202 void (*func) (unsigned long));
203static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
204static void prb_clear_rxhash(struct tpacket_kbdq_core *,
205 struct tpacket3_hdr *);
206static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
207 struct tpacket3_hdr *);
208static void packet_flush_mclist(struct sock *sk);
209
210#define PACKET_FANOUT_MAX 256
211
212struct packet_fanout {
213#ifdef CONFIG_NET_NS
214 struct net *net;
215#endif
216 unsigned int num_members;
217 u16 id;
218 u8 type;
219 u8 defrag;
220 atomic_t rr_cur;
221 struct list_head list;
222 struct sock *arr[PACKET_FANOUT_MAX];
223 spinlock_t lock;
224 atomic_t sk_ref;
225 struct packet_type prot_hook ____cacheline_aligned_in_smp;
226};
227
228struct packet_skb_cb {
229 unsigned int origlen;
230 union {
231 struct sockaddr_pkt pkt;
232 struct sockaddr_ll ll;
233 } sa;
234};
235
236#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
237
238#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
239#define GET_PBLOCK_DESC(x, bid) \
240 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
241#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
242 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
243#define GET_NEXT_PRB_BLK_NUM(x) \
244 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
245 ((x)->kactive_blk_num+1) : 0)
246
247static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
248static void __fanout_link(struct sock *sk, struct packet_sock *po);
249
250/* register_prot_hook must be invoked with the po->bind_lock held,
251 * or from a context in which asynchronous accesses to the packet
252 * socket is not possible (packet_create()).
253 */
254static void register_prot_hook(struct sock *sk)
255{
256 struct packet_sock *po = pkt_sk(sk);
257 if (!po->running) {
258 if (po->fanout)
259 __fanout_link(sk, po);
260 else
261 dev_add_pack(&po->prot_hook);
262 sock_hold(sk);
263 po->running = 1;
264 }
265}
266
267/* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
268 * held. If the sync parameter is true, we will temporarily drop
269 * the po->bind_lock and do a synchronize_net to make sure no
270 * asynchronous packet processing paths still refer to the elements
271 * of po->prot_hook. If the sync parameter is false, it is the
272 * callers responsibility to take care of this.
273 */
274static void __unregister_prot_hook(struct sock *sk, bool sync)
275{
276 struct packet_sock *po = pkt_sk(sk);
277
278 po->running = 0;
279 if (po->fanout)
280 __fanout_unlink(sk, po);
281 else
282 __dev_remove_pack(&po->prot_hook);
283 __sock_put(sk);
284
285 if (sync) {
286 spin_unlock(&po->bind_lock);
287 synchronize_net();
288 spin_lock(&po->bind_lock);
289 }
290}
291
292static void unregister_prot_hook(struct sock *sk, bool sync)
293{
294 struct packet_sock *po = pkt_sk(sk);
295
296 if (po->running)
297 __unregister_prot_hook(sk, sync);
298}
299
300static inline __pure struct page *pgv_to_page(void *addr)
301{
302 if (is_vmalloc_addr(addr))
303 return vmalloc_to_page(addr);
304 return virt_to_page(addr);
305}
306
307static void __packet_set_status(struct packet_sock *po, void *frame, int status)
308{
309 union {
310 struct tpacket_hdr *h1;
311 struct tpacket2_hdr *h2;
312 void *raw;
313 } h;
314
315 h.raw = frame;
316 switch (po->tp_version) {
317 case TPACKET_V1:
318 h.h1->tp_status = status;
319 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
320 break;
321 case TPACKET_V2:
322 h.h2->tp_status = status;
323 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
324 break;
325 case TPACKET_V3:
326 default:
327 WARN(1, "TPACKET version not supported.\n");
328 BUG();
329 }
330
331 smp_wmb();
332}
333
334static int __packet_get_status(struct packet_sock *po, void *frame)
335{
336 union {
337 struct tpacket_hdr *h1;
338 struct tpacket2_hdr *h2;
339 void *raw;
340 } h;
341
342 smp_rmb();
343
344 h.raw = frame;
345 switch (po->tp_version) {
346 case TPACKET_V1:
347 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
348 return h.h1->tp_status;
349 case TPACKET_V2:
350 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
351 return h.h2->tp_status;
352 case TPACKET_V3:
353 default:
354 WARN(1, "TPACKET version not supported.\n");
355 BUG();
356 return 0;
357 }
358}
359
360static void *packet_lookup_frame(struct packet_sock *po,
361 struct packet_ring_buffer *rb,
362 unsigned int position,
363 int status)
364{
365 unsigned int pg_vec_pos, frame_offset;
366 union {
367 struct tpacket_hdr *h1;
368 struct tpacket2_hdr *h2;
369 void *raw;
370 } h;
371
372 pg_vec_pos = position / rb->frames_per_block;
373 frame_offset = position % rb->frames_per_block;
374
375 h.raw = rb->pg_vec[pg_vec_pos].buffer +
376 (frame_offset * rb->frame_size);
377
378 if (status != __packet_get_status(po, h.raw))
379 return NULL;
380
381 return h.raw;
382}
383
384static void *packet_current_frame(struct packet_sock *po,
385 struct packet_ring_buffer *rb,
386 int status)
387{
388 return packet_lookup_frame(po, rb, rb->head, status);
389}
390
391static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
392{
393 del_timer_sync(&pkc->retire_blk_timer);
394}
395
396static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
397 int tx_ring,
398 struct sk_buff_head *rb_queue)
399{
400 struct tpacket_kbdq_core *pkc;
401
402 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
403
404 spin_lock(&rb_queue->lock);
405 pkc->delete_blk_timer = 1;
406 spin_unlock(&rb_queue->lock);
407
408 prb_del_retire_blk_timer(pkc);
409}
410
411static void prb_init_blk_timer(struct packet_sock *po,
412 struct tpacket_kbdq_core *pkc,
413 void (*func) (unsigned long))
414{
415 init_timer(&pkc->retire_blk_timer);
416 pkc->retire_blk_timer.data = (long)po;
417 pkc->retire_blk_timer.function = func;
418 pkc->retire_blk_timer.expires = jiffies;
419}
420
421static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
422{
423 struct tpacket_kbdq_core *pkc;
424
425 if (tx_ring)
426 BUG();
427
428 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
429 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
430}
431
432static int prb_calc_retire_blk_tmo(struct packet_sock *po,
433 int blk_size_in_bytes)
434{
435 struct net_device *dev;
436 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
437 struct ethtool_cmd ecmd;
438 int err;
439 u32 speed;
440
441 rtnl_lock();
442 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
443 if (unlikely(!dev)) {
444 rtnl_unlock();
445 return DEFAULT_PRB_RETIRE_TOV;
446 }
447 err = __ethtool_get_settings(dev, &ecmd);
448 speed = ethtool_cmd_speed(&ecmd);
449 rtnl_unlock();
450 if (!err) {
451 /*
452 * If the link speed is so slow you don't really
453 * need to worry about perf anyways
454 */
455 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
456 return DEFAULT_PRB_RETIRE_TOV;
457 } else {
458 msec = 1;
459 div = speed / 1000;
460 }
461 }
462
463 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
464
465 if (div)
466 mbits /= div;
467
468 tmo = mbits * msec;
469
470 if (div)
471 return tmo+1;
472 return tmo;
473}
474
475static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
476 union tpacket_req_u *req_u)
477{
478 p1->feature_req_word = req_u->req3.tp_feature_req_word;
479}
480
481static void init_prb_bdqc(struct packet_sock *po,
482 struct packet_ring_buffer *rb,
483 struct pgv *pg_vec,
484 union tpacket_req_u *req_u, int tx_ring)
485{
486 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
487 struct tpacket_block_desc *pbd;
488
489 memset(p1, 0x0, sizeof(*p1));
490
491 p1->knxt_seq_num = 1;
492 p1->pkbdq = pg_vec;
493 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
494 p1->pkblk_start = pg_vec[0].buffer;
495 p1->kblk_size = req_u->req3.tp_block_size;
496 p1->knum_blocks = req_u->req3.tp_block_nr;
497 p1->hdrlen = po->tp_hdrlen;
498 p1->version = po->tp_version;
499 p1->last_kactive_blk_num = 0;
500 po->stats_u.stats3.tp_freeze_q_cnt = 0;
501 if (req_u->req3.tp_retire_blk_tov)
502 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
503 else
504 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
505 req_u->req3.tp_block_size);
506 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
507 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
508
509 prb_init_ft_ops(p1, req_u);
510 prb_setup_retire_blk_timer(po, tx_ring);
511 prb_open_block(p1, pbd);
512}
513
514/* Do NOT update the last_blk_num first.
515 * Assumes sk_buff_head lock is held.
516 */
517static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
518{
519 mod_timer(&pkc->retire_blk_timer,
520 jiffies + pkc->tov_in_jiffies);
521 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
522}
523
524/*
525 * Timer logic:
526 * 1) We refresh the timer only when we open a block.
527 * By doing this we don't waste cycles refreshing the timer
528 * on packet-by-packet basis.
529 *
530 * With a 1MB block-size, on a 1Gbps line, it will take
531 * i) ~8 ms to fill a block + ii) memcpy etc.
532 * In this cut we are not accounting for the memcpy time.
533 *
534 * So, if the user sets the 'tmo' to 10ms then the timer
535 * will never fire while the block is still getting filled
536 * (which is what we want). However, the user could choose
537 * to close a block early and that's fine.
538 *
539 * But when the timer does fire, we check whether or not to refresh it.
540 * Since the tmo granularity is in msecs, it is not too expensive
541 * to refresh the timer, lets say every '8' msecs.
542 * Either the user can set the 'tmo' or we can derive it based on
543 * a) line-speed and b) block-size.
544 * prb_calc_retire_blk_tmo() calculates the tmo.
545 *
546 */
547static void prb_retire_rx_blk_timer_expired(unsigned long data)
548{
549 struct packet_sock *po = (struct packet_sock *)data;
550 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
551 unsigned int frozen;
552 struct tpacket_block_desc *pbd;
553
554 spin_lock(&po->sk.sk_receive_queue.lock);
555
556 frozen = prb_queue_frozen(pkc);
557 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
558
559 if (unlikely(pkc->delete_blk_timer))
560 goto out;
561
562 /* We only need to plug the race when the block is partially filled.
563 * tpacket_rcv:
564 * lock(); increment BLOCK_NUM_PKTS; unlock()
565 * copy_bits() is in progress ...
566 * timer fires on other cpu:
567 * we can't retire the current block because copy_bits
568 * is in progress.
569 *
570 */
571 if (BLOCK_NUM_PKTS(pbd)) {
572 while (atomic_read(&pkc->blk_fill_in_prog)) {
573 /* Waiting for skb_copy_bits to finish... */
574 cpu_relax();
575 }
576 }
577
578 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
579 if (!frozen) {
580 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
581 if (!prb_dispatch_next_block(pkc, po))
582 goto refresh_timer;
583 else
584 goto out;
585 } else {
586 /* Case 1. Queue was frozen because user-space was
587 * lagging behind.
588 */
589 if (prb_curr_blk_in_use(pkc, pbd)) {
590 /*
591 * Ok, user-space is still behind.
592 * So just refresh the timer.
593 */
594 goto refresh_timer;
595 } else {
596 /* Case 2. queue was frozen,user-space caught up,
597 * now the link went idle && the timer fired.
598 * We don't have a block to close.So we open this
599 * block and restart the timer.
600 * opening a block thaws the queue,restarts timer
601 * Thawing/timer-refresh is a side effect.
602 */
603 prb_open_block(pkc, pbd);
604 goto out;
605 }
606 }
607 }
608
609refresh_timer:
610 _prb_refresh_rx_retire_blk_timer(pkc);
611
612out:
613 spin_unlock(&po->sk.sk_receive_queue.lock);
614}
615
616static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
617 struct tpacket_block_desc *pbd1, __u32 status)
618{
619 /* Flush everything minus the block header */
620
621#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
622 u8 *start, *end;
623
624 start = (u8 *)pbd1;
625
626 /* Skip the block header(we know header WILL fit in 4K) */
627 start += PAGE_SIZE;
628
629 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
630 for (; start < end; start += PAGE_SIZE)
631 flush_dcache_page(pgv_to_page(start));
632
633 smp_wmb();
634#endif
635
636 /* Now update the block status. */
637
638 BLOCK_STATUS(pbd1) = status;
639
640 /* Flush the block header */
641
642#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
643 start = (u8 *)pbd1;
644 flush_dcache_page(pgv_to_page(start));
645
646 smp_wmb();
647#endif
648}
649
650/*
651 * Side effect:
652 *
653 * 1) flush the block
654 * 2) Increment active_blk_num
655 *
656 * Note:We DONT refresh the timer on purpose.
657 * Because almost always the next block will be opened.
658 */
659static void prb_close_block(struct tpacket_kbdq_core *pkc1,
660 struct tpacket_block_desc *pbd1,
661 struct packet_sock *po, unsigned int stat)
662{
663 __u32 status = TP_STATUS_USER | stat;
664
665 struct tpacket3_hdr *last_pkt;
666 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
667
668 if (po->stats.tp_drops)
669 status |= TP_STATUS_LOSING;
670
671 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
672 last_pkt->tp_next_offset = 0;
673
674 /* Get the ts of the last pkt */
675 if (BLOCK_NUM_PKTS(pbd1)) {
676 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
677 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
678 } else {
679 /* Ok, we tmo'd - so get the current time */
680 struct timespec ts;
681 getnstimeofday(&ts);
682 h1->ts_last_pkt.ts_sec = ts.tv_sec;
683 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
684 }
685
686 smp_wmb();
687
688 /* Flush the block */
689 prb_flush_block(pkc1, pbd1, status);
690
691 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
692}
693
694static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
695{
696 pkc->reset_pending_on_curr_blk = 0;
697}
698
699/*
700 * Side effect of opening a block:
701 *
702 * 1) prb_queue is thawed.
703 * 2) retire_blk_timer is refreshed.
704 *
705 */
706static void prb_open_block(struct tpacket_kbdq_core *pkc1,
707 struct tpacket_block_desc *pbd1)
708{
709 struct timespec ts;
710 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
711
712 smp_rmb();
713
714 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) {
715
716 /* We could have just memset this but we will lose the
717 * flexibility of making the priv area sticky
718 */
719 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
720 BLOCK_NUM_PKTS(pbd1) = 0;
721 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
722 getnstimeofday(&ts);
723 h1->ts_first_pkt.ts_sec = ts.tv_sec;
724 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
725 pkc1->pkblk_start = (char *)pbd1;
726 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
727 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
728 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
729 pbd1->version = pkc1->version;
730 pkc1->prev = pkc1->nxt_offset;
731 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
732 prb_thaw_queue(pkc1);
733 _prb_refresh_rx_retire_blk_timer(pkc1);
734
735 smp_wmb();
736
737 return;
738 }
739
740 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n",
741 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num);
742 dump_stack();
743 BUG();
744}
745
746/*
747 * Queue freeze logic:
748 * 1) Assume tp_block_nr = 8 blocks.
749 * 2) At time 't0', user opens Rx ring.
750 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
751 * 4) user-space is either sleeping or processing block '0'.
752 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
753 * it will close block-7,loop around and try to fill block '0'.
754 * call-flow:
755 * __packet_lookup_frame_in_block
756 * prb_retire_current_block()
757 * prb_dispatch_next_block()
758 * |->(BLOCK_STATUS == USER) evaluates to true
759 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
760 * 6) Now there are two cases:
761 * 6.1) Link goes idle right after the queue is frozen.
762 * But remember, the last open_block() refreshed the timer.
763 * When this timer expires,it will refresh itself so that we can
764 * re-open block-0 in near future.
765 * 6.2) Link is busy and keeps on receiving packets. This is a simple
766 * case and __packet_lookup_frame_in_block will check if block-0
767 * is free and can now be re-used.
768 */
769static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
770 struct packet_sock *po)
771{
772 pkc->reset_pending_on_curr_blk = 1;
773 po->stats_u.stats3.tp_freeze_q_cnt++;
774}
775
776#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
777
778/*
779 * If the next block is free then we will dispatch it
780 * and return a good offset.
781 * Else, we will freeze the queue.
782 * So, caller must check the return value.
783 */
784static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
785 struct packet_sock *po)
786{
787 struct tpacket_block_desc *pbd;
788
789 smp_rmb();
790
791 /* 1. Get current block num */
792 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
793
794 /* 2. If this block is currently in_use then freeze the queue */
795 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
796 prb_freeze_queue(pkc, po);
797 return NULL;
798 }
799
800 /*
801 * 3.
802 * open this block and return the offset where the first packet
803 * needs to get stored.
804 */
805 prb_open_block(pkc, pbd);
806 return (void *)pkc->nxt_offset;
807}
808
809static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
810 struct packet_sock *po, unsigned int status)
811{
812 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
813
814 /* retire/close the current block */
815 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
816 /*
817 * Plug the case where copy_bits() is in progress on
818 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
819 * have space to copy the pkt in the current block and
820 * called prb_retire_current_block()
821 *
822 * We don't need to worry about the TMO case because
823 * the timer-handler already handled this case.
824 */
825 if (!(status & TP_STATUS_BLK_TMO)) {
826 while (atomic_read(&pkc->blk_fill_in_prog)) {
827 /* Waiting for skb_copy_bits to finish... */
828 cpu_relax();
829 }
830 }
831 prb_close_block(pkc, pbd, po, status);
832 return;
833 }
834
835 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd);
836 dump_stack();
837 BUG();
838}
839
840static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
841 struct tpacket_block_desc *pbd)
842{
843 return TP_STATUS_USER & BLOCK_STATUS(pbd);
844}
845
846static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
847{
848 return pkc->reset_pending_on_curr_blk;
849}
850
851static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
852{
853 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
854 atomic_dec(&pkc->blk_fill_in_prog);
855}
856
857static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
858 struct tpacket3_hdr *ppd)
859{
860 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
861}
862
863static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
864 struct tpacket3_hdr *ppd)
865{
866 ppd->hv1.tp_rxhash = 0;
867}
868
869static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
870 struct tpacket3_hdr *ppd)
871{
872 if (vlan_tx_tag_present(pkc->skb)) {
873 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
874 ppd->tp_status = TP_STATUS_VLAN_VALID;
875 } else {
876 ppd->hv1.tp_vlan_tci = ppd->tp_status = 0;
877 }
878}
879
880static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
881 struct tpacket3_hdr *ppd)
882{
883 prb_fill_vlan_info(pkc, ppd);
884
885 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
886 prb_fill_rxhash(pkc, ppd);
887 else
888 prb_clear_rxhash(pkc, ppd);
889}
890
891static void prb_fill_curr_block(char *curr,
892 struct tpacket_kbdq_core *pkc,
893 struct tpacket_block_desc *pbd,
894 unsigned int len)
895{
896 struct tpacket3_hdr *ppd;
897
898 ppd = (struct tpacket3_hdr *)curr;
899 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
900 pkc->prev = curr;
901 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
902 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
903 BLOCK_NUM_PKTS(pbd) += 1;
904 atomic_inc(&pkc->blk_fill_in_prog);
905 prb_run_all_ft_ops(pkc, ppd);
906}
907
908/* Assumes caller has the sk->rx_queue.lock */
909static void *__packet_lookup_frame_in_block(struct packet_sock *po,
910 struct sk_buff *skb,
911 int status,
912 unsigned int len
913 )
914{
915 struct tpacket_kbdq_core *pkc;
916 struct tpacket_block_desc *pbd;
917 char *curr, *end;
918
919 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
920 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
921
922 /* Queue is frozen when user space is lagging behind */
923 if (prb_queue_frozen(pkc)) {
924 /*
925 * Check if that last block which caused the queue to freeze,
926 * is still in_use by user-space.
927 */
928 if (prb_curr_blk_in_use(pkc, pbd)) {
929 /* Can't record this packet */
930 return NULL;
931 } else {
932 /*
933 * Ok, the block was released by user-space.
934 * Now let's open that block.
935 * opening a block also thaws the queue.
936 * Thawing is a side effect.
937 */
938 prb_open_block(pkc, pbd);
939 }
940 }
941
942 smp_mb();
943 curr = pkc->nxt_offset;
944 pkc->skb = skb;
945 end = (char *)pbd + pkc->kblk_size;
946
947 /* first try the current block */
948 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
949 prb_fill_curr_block(curr, pkc, pbd, len);
950 return (void *)curr;
951 }
952
953 /* Ok, close the current block */
954 prb_retire_current_block(pkc, po, 0);
955
956 /* Now, try to dispatch the next block */
957 curr = (char *)prb_dispatch_next_block(pkc, po);
958 if (curr) {
959 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
960 prb_fill_curr_block(curr, pkc, pbd, len);
961 return (void *)curr;
962 }
963
964 /*
965 * No free blocks are available.user_space hasn't caught up yet.
966 * Queue was just frozen and now this packet will get dropped.
967 */
968 return NULL;
969}
970
971static void *packet_current_rx_frame(struct packet_sock *po,
972 struct sk_buff *skb,
973 int status, unsigned int len)
974{
975 char *curr = NULL;
976 switch (po->tp_version) {
977 case TPACKET_V1:
978 case TPACKET_V2:
979 curr = packet_lookup_frame(po, &po->rx_ring,
980 po->rx_ring.head, status);
981 return curr;
982 case TPACKET_V3:
983 return __packet_lookup_frame_in_block(po, skb, status, len);
984 default:
985 WARN(1, "TPACKET version not supported\n");
986 BUG();
987 return 0;
988 }
989}
990
991static void *prb_lookup_block(struct packet_sock *po,
992 struct packet_ring_buffer *rb,
993 unsigned int previous,
994 int status)
995{
996 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
997 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
998
999 if (status != BLOCK_STATUS(pbd))
1000 return NULL;
1001 return pbd;
1002}
1003
1004static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1005{
1006 unsigned int prev;
1007 if (rb->prb_bdqc.kactive_blk_num)
1008 prev = rb->prb_bdqc.kactive_blk_num-1;
1009 else
1010 prev = rb->prb_bdqc.knum_blocks-1;
1011 return prev;
1012}
1013
1014/* Assumes caller has held the rx_queue.lock */
1015static void *__prb_previous_block(struct packet_sock *po,
1016 struct packet_ring_buffer *rb,
1017 int status)
1018{
1019 unsigned int previous = prb_previous_blk_num(rb);
1020 return prb_lookup_block(po, rb, previous, status);
1021}
1022
1023static void *packet_previous_rx_frame(struct packet_sock *po,
1024 struct packet_ring_buffer *rb,
1025 int status)
1026{
1027 if (po->tp_version <= TPACKET_V2)
1028 return packet_previous_frame(po, rb, status);
1029
1030 return __prb_previous_block(po, rb, status);
1031}
1032
1033static void packet_increment_rx_head(struct packet_sock *po,
1034 struct packet_ring_buffer *rb)
1035{
1036 switch (po->tp_version) {
1037 case TPACKET_V1:
1038 case TPACKET_V2:
1039 return packet_increment_head(rb);
1040 case TPACKET_V3:
1041 default:
1042 WARN(1, "TPACKET version not supported.\n");
1043 BUG();
1044 return;
1045 }
1046}
1047
1048static void *packet_previous_frame(struct packet_sock *po,
1049 struct packet_ring_buffer *rb,
1050 int status)
1051{
1052 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1053 return packet_lookup_frame(po, rb, previous, status);
1054}
1055
1056static void packet_increment_head(struct packet_ring_buffer *buff)
1057{
1058 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1059}
1060
1061static void packet_sock_destruct(struct sock *sk)
1062{
1063 skb_queue_purge(&sk->sk_error_queue);
1064
1065 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1066 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1067
1068 if (!sock_flag(sk, SOCK_DEAD)) {
1069 pr_err("Attempt to release alive packet socket: %p\n", sk);
1070 return;
1071 }
1072
1073 sk_refcnt_debug_dec(sk);
1074}
1075
1076static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1077{
1078 int x = atomic_read(&f->rr_cur) + 1;
1079
1080 if (x >= num)
1081 x = 0;
1082
1083 return x;
1084}
1085
1086static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1087{
1088 u32 idx, hash = skb->rxhash;
1089
1090 idx = ((u64)hash * num) >> 32;
1091
1092 return f->arr[idx];
1093}
1094
1095static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1096{
1097 int cur, old;
1098
1099 cur = atomic_read(&f->rr_cur);
1100 while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1101 fanout_rr_next(f, num))) != cur)
1102 cur = old;
1103 return f->arr[cur];
1104}
1105
1106static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1107{
1108 unsigned int cpu = smp_processor_id();
1109
1110 return f->arr[cpu % num];
1111}
1112
1113static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1114 struct packet_type *pt, struct net_device *orig_dev)
1115{
1116 struct packet_fanout *f = pt->af_packet_priv;
1117 unsigned int num = f->num_members;
1118 struct packet_sock *po;
1119 struct sock *sk;
1120
1121 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1122 !num) {
1123 kfree_skb(skb);
1124 return 0;
1125 }
1126
1127 switch (f->type) {
1128 case PACKET_FANOUT_HASH:
1129 default:
1130 if (f->defrag) {
1131 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1132 if (!skb)
1133 return 0;
1134 }
1135 skb_get_rxhash(skb);
1136 sk = fanout_demux_hash(f, skb, num);
1137 break;
1138 case PACKET_FANOUT_LB:
1139 sk = fanout_demux_lb(f, skb, num);
1140 break;
1141 case PACKET_FANOUT_CPU:
1142 sk = fanout_demux_cpu(f, skb, num);
1143 break;
1144 }
1145
1146 po = pkt_sk(sk);
1147
1148 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1149}
1150
1151static DEFINE_MUTEX(fanout_mutex);
1152static LIST_HEAD(fanout_list);
1153
1154static void __fanout_link(struct sock *sk, struct packet_sock *po)
1155{
1156 struct packet_fanout *f = po->fanout;
1157
1158 spin_lock(&f->lock);
1159 f->arr[f->num_members] = sk;
1160 smp_wmb();
1161 f->num_members++;
1162 spin_unlock(&f->lock);
1163}
1164
1165static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1166{
1167 struct packet_fanout *f = po->fanout;
1168 int i;
1169
1170 spin_lock(&f->lock);
1171 for (i = 0; i < f->num_members; i++) {
1172 if (f->arr[i] == sk)
1173 break;
1174 }
1175 BUG_ON(i >= f->num_members);
1176 f->arr[i] = f->arr[f->num_members - 1];
1177 f->num_members--;
1178 spin_unlock(&f->lock);
1179}
1180
1181static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1182{
1183 struct packet_sock *po = pkt_sk(sk);
1184 struct packet_fanout *f, *match;
1185 u8 type = type_flags & 0xff;
1186 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
1187 int err;
1188
1189 switch (type) {
1190 case PACKET_FANOUT_HASH:
1191 case PACKET_FANOUT_LB:
1192 case PACKET_FANOUT_CPU:
1193 break;
1194 default:
1195 return -EINVAL;
1196 }
1197
1198 if (!po->running)
1199 return -EINVAL;
1200
1201 if (po->fanout)
1202 return -EALREADY;
1203
1204 mutex_lock(&fanout_mutex);
1205 match = NULL;
1206 list_for_each_entry(f, &fanout_list, list) {
1207 if (f->id == id &&
1208 read_pnet(&f->net) == sock_net(sk)) {
1209 match = f;
1210 break;
1211 }
1212 }
1213 err = -EINVAL;
1214 if (match && match->defrag != defrag)
1215 goto out;
1216 if (!match) {
1217 err = -ENOMEM;
1218 match = kzalloc(sizeof(*match), GFP_KERNEL);
1219 if (!match)
1220 goto out;
1221 write_pnet(&match->net, sock_net(sk));
1222 match->id = id;
1223 match->type = type;
1224 match->defrag = defrag;
1225 atomic_set(&match->rr_cur, 0);
1226 INIT_LIST_HEAD(&match->list);
1227 spin_lock_init(&match->lock);
1228 atomic_set(&match->sk_ref, 0);
1229 match->prot_hook.type = po->prot_hook.type;
1230 match->prot_hook.dev = po->prot_hook.dev;
1231 match->prot_hook.func = packet_rcv_fanout;
1232 match->prot_hook.af_packet_priv = match;
1233 dev_add_pack(&match->prot_hook);
1234 list_add(&match->list, &fanout_list);
1235 }
1236 err = -EINVAL;
1237 if (match->type == type &&
1238 match->prot_hook.type == po->prot_hook.type &&
1239 match->prot_hook.dev == po->prot_hook.dev) {
1240 err = -ENOSPC;
1241 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1242 __dev_remove_pack(&po->prot_hook);
1243 po->fanout = match;
1244 atomic_inc(&match->sk_ref);
1245 __fanout_link(sk, po);
1246 err = 0;
1247 }
1248 }
1249out:
1250 mutex_unlock(&fanout_mutex);
1251 return err;
1252}
1253
1254static void fanout_release(struct sock *sk)
1255{
1256 struct packet_sock *po = pkt_sk(sk);
1257 struct packet_fanout *f;
1258
1259 f = po->fanout;
1260 if (!f)
1261 return;
1262
1263 po->fanout = NULL;
1264
1265 mutex_lock(&fanout_mutex);
1266 if (atomic_dec_and_test(&f->sk_ref)) {
1267 list_del(&f->list);
1268 dev_remove_pack(&f->prot_hook);
1269 kfree(f);
1270 }
1271 mutex_unlock(&fanout_mutex);
1272}
1273
1274static const struct proto_ops packet_ops;
1275
1276static const struct proto_ops packet_ops_spkt;
1277
1278static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1279 struct packet_type *pt, struct net_device *orig_dev)
1280{
1281 struct sock *sk;
1282 struct sockaddr_pkt *spkt;
1283
1284 /*
1285 * When we registered the protocol we saved the socket in the data
1286 * field for just this event.
1287 */
1288
1289 sk = pt->af_packet_priv;
1290
1291 /*
1292 * Yank back the headers [hope the device set this
1293 * right or kerboom...]
1294 *
1295 * Incoming packets have ll header pulled,
1296 * push it back.
1297 *
1298 * For outgoing ones skb->data == skb_mac_header(skb)
1299 * so that this procedure is noop.
1300 */
1301
1302 if (skb->pkt_type == PACKET_LOOPBACK)
1303 goto out;
1304
1305 if (!net_eq(dev_net(dev), sock_net(sk)))
1306 goto out;
1307
1308 skb = skb_share_check(skb, GFP_ATOMIC);
1309 if (skb == NULL)
1310 goto oom;
1311
1312 /* drop any routing info */
1313 skb_dst_drop(skb);
1314
1315 /* drop conntrack reference */
1316 nf_reset(skb);
1317
1318 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1319
1320 skb_push(skb, skb->data - skb_mac_header(skb));
1321
1322 /*
1323 * The SOCK_PACKET socket receives _all_ frames.
1324 */
1325
1326 spkt->spkt_family = dev->type;
1327 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1328 spkt->spkt_protocol = skb->protocol;
1329
1330 /*
1331 * Charge the memory to the socket. This is done specifically
1332 * to prevent sockets using all the memory up.
1333 */
1334
1335 if (sock_queue_rcv_skb(sk, skb) == 0)
1336 return 0;
1337
1338out:
1339 kfree_skb(skb);
1340oom:
1341 return 0;
1342}
1343
1344
1345/*
1346 * Output a raw packet to a device layer. This bypasses all the other
1347 * protocol layers and you must therefore supply it with a complete frame
1348 */
1349
1350static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1351 struct msghdr *msg, size_t len)
1352{
1353 struct sock *sk = sock->sk;
1354 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1355 struct sk_buff *skb = NULL;
1356 struct net_device *dev;
1357 __be16 proto = 0;
1358 int err;
1359 int extra_len = 0;
1360
1361 /*
1362 * Get and verify the address.
1363 */
1364
1365 if (saddr) {
1366 if (msg->msg_namelen < sizeof(struct sockaddr))
1367 return -EINVAL;
1368 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1369 proto = saddr->spkt_protocol;
1370 } else
1371 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1372
1373 /*
1374 * Find the device first to size check it
1375 */
1376
1377 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1378retry:
1379 rcu_read_lock();
1380 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1381 err = -ENODEV;
1382 if (dev == NULL)
1383 goto out_unlock;
1384
1385 err = -ENETDOWN;
1386 if (!(dev->flags & IFF_UP))
1387 goto out_unlock;
1388
1389 /*
1390 * You may not queue a frame bigger than the mtu. This is the lowest level
1391 * raw protocol and you must do your own fragmentation at this level.
1392 */
1393
1394 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1395 if (!netif_supports_nofcs(dev)) {
1396 err = -EPROTONOSUPPORT;
1397 goto out_unlock;
1398 }
1399 extra_len = 4; /* We're doing our own CRC */
1400 }
1401
1402 err = -EMSGSIZE;
1403 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1404 goto out_unlock;
1405
1406 if (!skb) {
1407 size_t reserved = LL_RESERVED_SPACE(dev);
1408 int tlen = dev->needed_tailroom;
1409 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1410
1411 rcu_read_unlock();
1412 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1413 if (skb == NULL)
1414 return -ENOBUFS;
1415 /* FIXME: Save some space for broken drivers that write a hard
1416 * header at transmission time by themselves. PPP is the notable
1417 * one here. This should really be fixed at the driver level.
1418 */
1419 skb_reserve(skb, reserved);
1420 skb_reset_network_header(skb);
1421
1422 /* Try to align data part correctly */
1423 if (hhlen) {
1424 skb->data -= hhlen;
1425 skb->tail -= hhlen;
1426 if (len < hhlen)
1427 skb_reset_network_header(skb);
1428 }
1429 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1430 if (err)
1431 goto out_free;
1432 goto retry;
1433 }
1434
1435 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1436 /* Earlier code assumed this would be a VLAN pkt,
1437 * double-check this now that we have the actual
1438 * packet in hand.
1439 */
1440 struct ethhdr *ehdr;
1441 skb_reset_mac_header(skb);
1442 ehdr = eth_hdr(skb);
1443 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1444 err = -EMSGSIZE;
1445 goto out_unlock;
1446 }
1447 }
1448
1449 skb->protocol = proto;
1450 skb->dev = dev;
1451 skb->priority = sk->sk_priority;
1452 skb->mark = sk->sk_mark;
1453 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1454 if (err < 0)
1455 goto out_unlock;
1456
1457 if (unlikely(extra_len == 4))
1458 skb->no_fcs = 1;
1459
1460 dev_queue_xmit(skb);
1461 rcu_read_unlock();
1462 return len;
1463
1464out_unlock:
1465 rcu_read_unlock();
1466out_free:
1467 kfree_skb(skb);
1468 return err;
1469}
1470
1471static unsigned int run_filter(const struct sk_buff *skb,
1472 const struct sock *sk,
1473 unsigned int res)
1474{
1475 struct sk_filter *filter;
1476
1477 rcu_read_lock();
1478 filter = rcu_dereference(sk->sk_filter);
1479 if (filter != NULL)
1480 res = SK_RUN_FILTER(filter, skb);
1481 rcu_read_unlock();
1482
1483 return res;
1484}
1485
1486/*
1487 * This function makes lazy skb cloning in hope that most of packets
1488 * are discarded by BPF.
1489 *
1490 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1491 * and skb->cb are mangled. It works because (and until) packets
1492 * falling here are owned by current CPU. Output packets are cloned
1493 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1494 * sequencially, so that if we return skb to original state on exit,
1495 * we will not harm anyone.
1496 */
1497
1498static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1499 struct packet_type *pt, struct net_device *orig_dev)
1500{
1501 struct sock *sk;
1502 struct sockaddr_ll *sll;
1503 struct packet_sock *po;
1504 u8 *skb_head = skb->data;
1505 int skb_len = skb->len;
1506 unsigned int snaplen, res;
1507
1508 if (skb->pkt_type == PACKET_LOOPBACK)
1509 goto drop;
1510
1511 sk = pt->af_packet_priv;
1512 po = pkt_sk(sk);
1513
1514 if (!net_eq(dev_net(dev), sock_net(sk)))
1515 goto drop;
1516
1517 skb->dev = dev;
1518
1519 if (dev->header_ops) {
1520 /* The device has an explicit notion of ll header,
1521 * exported to higher levels.
1522 *
1523 * Otherwise, the device hides details of its frame
1524 * structure, so that corresponding packet head is
1525 * never delivered to user.
1526 */
1527 if (sk->sk_type != SOCK_DGRAM)
1528 skb_push(skb, skb->data - skb_mac_header(skb));
1529 else if (skb->pkt_type == PACKET_OUTGOING) {
1530 /* Special case: outgoing packets have ll header at head */
1531 skb_pull(skb, skb_network_offset(skb));
1532 }
1533 }
1534
1535 snaplen = skb->len;
1536
1537 res = run_filter(skb, sk, snaplen);
1538 if (!res)
1539 goto drop_n_restore;
1540 if (snaplen > res)
1541 snaplen = res;
1542
1543 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1544 goto drop_n_acct;
1545
1546 if (skb_shared(skb)) {
1547 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1548 if (nskb == NULL)
1549 goto drop_n_acct;
1550
1551 if (skb_head != skb->data) {
1552 skb->data = skb_head;
1553 skb->len = skb_len;
1554 }
1555 consume_skb(skb);
1556 skb = nskb;
1557 }
1558
1559 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1560 sizeof(skb->cb));
1561
1562 sll = &PACKET_SKB_CB(skb)->sa.ll;
1563 sll->sll_family = AF_PACKET;
1564 sll->sll_hatype = dev->type;
1565 sll->sll_protocol = skb->protocol;
1566 sll->sll_pkttype = skb->pkt_type;
1567 if (unlikely(po->origdev))
1568 sll->sll_ifindex = orig_dev->ifindex;
1569 else
1570 sll->sll_ifindex = dev->ifindex;
1571
1572 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1573
1574 PACKET_SKB_CB(skb)->origlen = skb->len;
1575
1576 if (pskb_trim(skb, snaplen))
1577 goto drop_n_acct;
1578
1579 skb_set_owner_r(skb, sk);
1580 skb->dev = NULL;
1581 skb_dst_drop(skb);
1582
1583 /* drop conntrack reference */
1584 nf_reset(skb);
1585
1586 spin_lock(&sk->sk_receive_queue.lock);
1587 po->stats.tp_packets++;
1588 skb->dropcount = atomic_read(&sk->sk_drops);
1589 __skb_queue_tail(&sk->sk_receive_queue, skb);
1590 spin_unlock(&sk->sk_receive_queue.lock);
1591 sk->sk_data_ready(sk, skb->len);
1592 return 0;
1593
1594drop_n_acct:
1595 spin_lock(&sk->sk_receive_queue.lock);
1596 po->stats.tp_drops++;
1597 atomic_inc(&sk->sk_drops);
1598 spin_unlock(&sk->sk_receive_queue.lock);
1599
1600drop_n_restore:
1601 if (skb_head != skb->data && skb_shared(skb)) {
1602 skb->data = skb_head;
1603 skb->len = skb_len;
1604 }
1605drop:
1606 consume_skb(skb);
1607 return 0;
1608}
1609
1610static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1611 struct packet_type *pt, struct net_device *orig_dev)
1612{
1613 struct sock *sk;
1614 struct packet_sock *po;
1615 struct sockaddr_ll *sll;
1616 union {
1617 struct tpacket_hdr *h1;
1618 struct tpacket2_hdr *h2;
1619 struct tpacket3_hdr *h3;
1620 void *raw;
1621 } h;
1622 u8 *skb_head = skb->data;
1623 int skb_len = skb->len;
1624 unsigned int snaplen, res;
1625 unsigned long status = TP_STATUS_USER;
1626 unsigned short macoff, netoff, hdrlen;
1627 struct sk_buff *copy_skb = NULL;
1628 struct timeval tv;
1629 struct timespec ts;
1630 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
1631
1632 if (skb->pkt_type == PACKET_LOOPBACK)
1633 goto drop;
1634
1635 sk = pt->af_packet_priv;
1636 po = pkt_sk(sk);
1637
1638 if (!net_eq(dev_net(dev), sock_net(sk)))
1639 goto drop;
1640
1641 if (dev->header_ops) {
1642 if (sk->sk_type != SOCK_DGRAM)
1643 skb_push(skb, skb->data - skb_mac_header(skb));
1644 else if (skb->pkt_type == PACKET_OUTGOING) {
1645 /* Special case: outgoing packets have ll header at head */
1646 skb_pull(skb, skb_network_offset(skb));
1647 }
1648 }
1649
1650 if (skb->ip_summed == CHECKSUM_PARTIAL)
1651 status |= TP_STATUS_CSUMNOTREADY;
1652
1653 snaplen = skb->len;
1654
1655 res = run_filter(skb, sk, snaplen);
1656 if (!res)
1657 goto drop_n_restore;
1658 if (snaplen > res)
1659 snaplen = res;
1660
1661 if (sk->sk_type == SOCK_DGRAM) {
1662 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1663 po->tp_reserve;
1664 } else {
1665 unsigned int maclen = skb_network_offset(skb);
1666 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1667 (maclen < 16 ? 16 : maclen)) +
1668 po->tp_reserve;
1669 macoff = netoff - maclen;
1670 }
1671 if (po->tp_version <= TPACKET_V2) {
1672 if (macoff + snaplen > po->rx_ring.frame_size) {
1673 if (po->copy_thresh &&
1674 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1675 if (skb_shared(skb)) {
1676 copy_skb = skb_clone(skb, GFP_ATOMIC);
1677 } else {
1678 copy_skb = skb_get(skb);
1679 skb_head = skb->data;
1680 }
1681 if (copy_skb)
1682 skb_set_owner_r(copy_skb, sk);
1683 }
1684 snaplen = po->rx_ring.frame_size - macoff;
1685 if ((int)snaplen < 0)
1686 snaplen = 0;
1687 }
1688 }
1689 spin_lock(&sk->sk_receive_queue.lock);
1690 h.raw = packet_current_rx_frame(po, skb,
1691 TP_STATUS_KERNEL, (macoff+snaplen));
1692 if (!h.raw)
1693 goto ring_is_full;
1694 if (po->tp_version <= TPACKET_V2) {
1695 packet_increment_rx_head(po, &po->rx_ring);
1696 /*
1697 * LOSING will be reported till you read the stats,
1698 * because it's COR - Clear On Read.
1699 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1700 * at packet level.
1701 */
1702 if (po->stats.tp_drops)
1703 status |= TP_STATUS_LOSING;
1704 }
1705 po->stats.tp_packets++;
1706 if (copy_skb) {
1707 status |= TP_STATUS_COPY;
1708 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1709 }
1710 spin_unlock(&sk->sk_receive_queue.lock);
1711
1712 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1713
1714 switch (po->tp_version) {
1715 case TPACKET_V1:
1716 h.h1->tp_len = skb->len;
1717 h.h1->tp_snaplen = snaplen;
1718 h.h1->tp_mac = macoff;
1719 h.h1->tp_net = netoff;
1720 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1721 && shhwtstamps->syststamp.tv64)
1722 tv = ktime_to_timeval(shhwtstamps->syststamp);
1723 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1724 && shhwtstamps->hwtstamp.tv64)
1725 tv = ktime_to_timeval(shhwtstamps->hwtstamp);
1726 else if (skb->tstamp.tv64)
1727 tv = ktime_to_timeval(skb->tstamp);
1728 else
1729 do_gettimeofday(&tv);
1730 h.h1->tp_sec = tv.tv_sec;
1731 h.h1->tp_usec = tv.tv_usec;
1732 hdrlen = sizeof(*h.h1);
1733 break;
1734 case TPACKET_V2:
1735 h.h2->tp_len = skb->len;
1736 h.h2->tp_snaplen = snaplen;
1737 h.h2->tp_mac = macoff;
1738 h.h2->tp_net = netoff;
1739 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1740 && shhwtstamps->syststamp.tv64)
1741 ts = ktime_to_timespec(shhwtstamps->syststamp);
1742 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1743 && shhwtstamps->hwtstamp.tv64)
1744 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1745 else if (skb->tstamp.tv64)
1746 ts = ktime_to_timespec(skb->tstamp);
1747 else
1748 getnstimeofday(&ts);
1749 h.h2->tp_sec = ts.tv_sec;
1750 h.h2->tp_nsec = ts.tv_nsec;
1751 if (vlan_tx_tag_present(skb)) {
1752 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1753 status |= TP_STATUS_VLAN_VALID;
1754 } else {
1755 h.h2->tp_vlan_tci = 0;
1756 }
1757 h.h2->tp_padding = 0;
1758 hdrlen = sizeof(*h.h2);
1759 break;
1760 case TPACKET_V3:
1761 /* tp_nxt_offset,vlan are already populated above.
1762 * So DONT clear those fields here
1763 */
1764 h.h3->tp_status |= status;
1765 h.h3->tp_len = skb->len;
1766 h.h3->tp_snaplen = snaplen;
1767 h.h3->tp_mac = macoff;
1768 h.h3->tp_net = netoff;
1769 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1770 && shhwtstamps->syststamp.tv64)
1771 ts = ktime_to_timespec(shhwtstamps->syststamp);
1772 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1773 && shhwtstamps->hwtstamp.tv64)
1774 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1775 else if (skb->tstamp.tv64)
1776 ts = ktime_to_timespec(skb->tstamp);
1777 else
1778 getnstimeofday(&ts);
1779 h.h3->tp_sec = ts.tv_sec;
1780 h.h3->tp_nsec = ts.tv_nsec;
1781 hdrlen = sizeof(*h.h3);
1782 break;
1783 default:
1784 BUG();
1785 }
1786
1787 sll = h.raw + TPACKET_ALIGN(hdrlen);
1788 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1789 sll->sll_family = AF_PACKET;
1790 sll->sll_hatype = dev->type;
1791 sll->sll_protocol = skb->protocol;
1792 sll->sll_pkttype = skb->pkt_type;
1793 if (unlikely(po->origdev))
1794 sll->sll_ifindex = orig_dev->ifindex;
1795 else
1796 sll->sll_ifindex = dev->ifindex;
1797
1798 smp_mb();
1799#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1800 {
1801 u8 *start, *end;
1802
1803 if (po->tp_version <= TPACKET_V2) {
1804 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1805 + macoff + snaplen);
1806 for (start = h.raw; start < end; start += PAGE_SIZE)
1807 flush_dcache_page(pgv_to_page(start));
1808 }
1809 smp_wmb();
1810 }
1811#endif
1812 if (po->tp_version <= TPACKET_V2)
1813 __packet_set_status(po, h.raw, status);
1814 else
1815 prb_clear_blk_fill_status(&po->rx_ring);
1816
1817 sk->sk_data_ready(sk, 0);
1818
1819drop_n_restore:
1820 if (skb_head != skb->data && skb_shared(skb)) {
1821 skb->data = skb_head;
1822 skb->len = skb_len;
1823 }
1824drop:
1825 kfree_skb(skb);
1826 return 0;
1827
1828ring_is_full:
1829 po->stats.tp_drops++;
1830 spin_unlock(&sk->sk_receive_queue.lock);
1831
1832 sk->sk_data_ready(sk, 0);
1833 kfree_skb(copy_skb);
1834 goto drop_n_restore;
1835}
1836
1837static void tpacket_destruct_skb(struct sk_buff *skb)
1838{
1839 struct packet_sock *po = pkt_sk(skb->sk);
1840 void *ph;
1841
1842 if (likely(po->tx_ring.pg_vec)) {
1843 ph = skb_shinfo(skb)->destructor_arg;
1844 BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING);
1845 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1846 atomic_dec(&po->tx_ring.pending);
1847 __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
1848 }
1849
1850 sock_wfree(skb);
1851}
1852
1853static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1854 void *frame, struct net_device *dev, int size_max,
1855 __be16 proto, unsigned char *addr, int hlen)
1856{
1857 union {
1858 struct tpacket_hdr *h1;
1859 struct tpacket2_hdr *h2;
1860 void *raw;
1861 } ph;
1862 int to_write, offset, len, tp_len, nr_frags, len_max;
1863 struct socket *sock = po->sk.sk_socket;
1864 struct page *page;
1865 void *data;
1866 int err;
1867
1868 ph.raw = frame;
1869
1870 skb->protocol = proto;
1871 skb->dev = dev;
1872 skb->priority = po->sk.sk_priority;
1873 skb->mark = po->sk.sk_mark;
1874 skb_shinfo(skb)->destructor_arg = ph.raw;
1875
1876 switch (po->tp_version) {
1877 case TPACKET_V2:
1878 tp_len = ph.h2->tp_len;
1879 break;
1880 default:
1881 tp_len = ph.h1->tp_len;
1882 break;
1883 }
1884 if (unlikely(tp_len > size_max)) {
1885 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1886 return -EMSGSIZE;
1887 }
1888
1889 skb_reserve(skb, hlen);
1890 skb_reset_network_header(skb);
1891
1892 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1893 to_write = tp_len;
1894
1895 if (sock->type == SOCK_DGRAM) {
1896 err = dev_hard_header(skb, dev, ntohs(proto), addr,
1897 NULL, tp_len);
1898 if (unlikely(err < 0))
1899 return -EINVAL;
1900 } else if (dev->hard_header_len) {
1901 /* net device doesn't like empty head */
1902 if (unlikely(tp_len <= dev->hard_header_len)) {
1903 pr_err("packet size is too short (%d < %d)\n",
1904 tp_len, dev->hard_header_len);
1905 return -EINVAL;
1906 }
1907
1908 skb_push(skb, dev->hard_header_len);
1909 err = skb_store_bits(skb, 0, data,
1910 dev->hard_header_len);
1911 if (unlikely(err))
1912 return err;
1913
1914 data += dev->hard_header_len;
1915 to_write -= dev->hard_header_len;
1916 }
1917
1918 err = -EFAULT;
1919 offset = offset_in_page(data);
1920 len_max = PAGE_SIZE - offset;
1921 len = ((to_write > len_max) ? len_max : to_write);
1922
1923 skb->data_len = to_write;
1924 skb->len += to_write;
1925 skb->truesize += to_write;
1926 atomic_add(to_write, &po->sk.sk_wmem_alloc);
1927
1928 while (likely(to_write)) {
1929 nr_frags = skb_shinfo(skb)->nr_frags;
1930
1931 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
1932 pr_err("Packet exceed the number of skb frags(%lu)\n",
1933 MAX_SKB_FRAGS);
1934 return -EFAULT;
1935 }
1936
1937 page = pgv_to_page(data);
1938 data += len;
1939 flush_dcache_page(page);
1940 get_page(page);
1941 skb_fill_page_desc(skb, nr_frags, page, offset, len);
1942 to_write -= len;
1943 offset = 0;
1944 len_max = PAGE_SIZE;
1945 len = ((to_write > len_max) ? len_max : to_write);
1946 }
1947
1948 return tp_len;
1949}
1950
1951static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
1952{
1953 struct sk_buff *skb;
1954 struct net_device *dev;
1955 __be16 proto;
1956 bool need_rls_dev = false;
1957 int err, reserve = 0;
1958 void *ph;
1959 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
1960 int tp_len, size_max;
1961 unsigned char *addr;
1962 int len_sum = 0;
1963 int status = 0;
1964 int hlen, tlen;
1965
1966 mutex_lock(&po->pg_vec_lock);
1967
1968 err = -EBUSY;
1969 if (saddr == NULL) {
1970 dev = po->prot_hook.dev;
1971 proto = po->num;
1972 addr = NULL;
1973 } else {
1974 err = -EINVAL;
1975 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
1976 goto out;
1977 if (msg->msg_namelen < (saddr->sll_halen
1978 + offsetof(struct sockaddr_ll,
1979 sll_addr)))
1980 goto out;
1981 proto = saddr->sll_protocol;
1982 addr = saddr->sll_addr;
1983 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
1984 need_rls_dev = true;
1985 }
1986
1987 err = -ENXIO;
1988 if (unlikely(dev == NULL))
1989 goto out;
1990
1991 reserve = dev->hard_header_len;
1992
1993 err = -ENETDOWN;
1994 if (unlikely(!(dev->flags & IFF_UP)))
1995 goto out_put;
1996
1997 size_max = po->tx_ring.frame_size
1998 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
1999
2000 if (size_max > dev->mtu + reserve)
2001 size_max = dev->mtu + reserve;
2002
2003 do {
2004 ph = packet_current_frame(po, &po->tx_ring,
2005 TP_STATUS_SEND_REQUEST);
2006
2007 if (unlikely(ph == NULL)) {
2008 schedule();
2009 continue;
2010 }
2011
2012 status = TP_STATUS_SEND_REQUEST;
2013 hlen = LL_RESERVED_SPACE(dev);
2014 tlen = dev->needed_tailroom;
2015 skb = sock_alloc_send_skb(&po->sk,
2016 hlen + tlen + sizeof(struct sockaddr_ll),
2017 0, &err);
2018
2019 if (unlikely(skb == NULL))
2020 goto out_status;
2021
2022 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2023 addr, hlen);
2024
2025 if (unlikely(tp_len < 0)) {
2026 if (po->tp_loss) {
2027 __packet_set_status(po, ph,
2028 TP_STATUS_AVAILABLE);
2029 packet_increment_head(&po->tx_ring);
2030 kfree_skb(skb);
2031 continue;
2032 } else {
2033 status = TP_STATUS_WRONG_FORMAT;
2034 err = tp_len;
2035 goto out_status;
2036 }
2037 }
2038
2039 skb->destructor = tpacket_destruct_skb;
2040 __packet_set_status(po, ph, TP_STATUS_SENDING);
2041 atomic_inc(&po->tx_ring.pending);
2042
2043 status = TP_STATUS_SEND_REQUEST;
2044 err = dev_queue_xmit(skb);
2045 if (unlikely(err > 0)) {
2046 err = net_xmit_errno(err);
2047 if (err && __packet_get_status(po, ph) ==
2048 TP_STATUS_AVAILABLE) {
2049 /* skb was destructed already */
2050 skb = NULL;
2051 goto out_status;
2052 }
2053 /*
2054 * skb was dropped but not destructed yet;
2055 * let's treat it like congestion or err < 0
2056 */
2057 err = 0;
2058 }
2059 packet_increment_head(&po->tx_ring);
2060 len_sum += tp_len;
2061 } while (likely((ph != NULL) ||
2062 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2063 (atomic_read(&po->tx_ring.pending))))
2064 );
2065
2066 err = len_sum;
2067 goto out_put;
2068
2069out_status:
2070 __packet_set_status(po, ph, status);
2071 kfree_skb(skb);
2072out_put:
2073 if (need_rls_dev)
2074 dev_put(dev);
2075out:
2076 mutex_unlock(&po->pg_vec_lock);
2077 return err;
2078}
2079
2080static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2081 size_t reserve, size_t len,
2082 size_t linear, int noblock,
2083 int *err)
2084{
2085 struct sk_buff *skb;
2086
2087 /* Under a page? Don't bother with paged skb. */
2088 if (prepad + len < PAGE_SIZE || !linear)
2089 linear = len;
2090
2091 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2092 err);
2093 if (!skb)
2094 return NULL;
2095
2096 skb_reserve(skb, reserve);
2097 skb_put(skb, linear);
2098 skb->data_len = len - linear;
2099 skb->len += len - linear;
2100
2101 return skb;
2102}
2103
2104static int packet_snd(struct socket *sock,
2105 struct msghdr *msg, size_t len)
2106{
2107 struct sock *sk = sock->sk;
2108 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2109 struct sk_buff *skb;
2110 struct net_device *dev;
2111 __be16 proto;
2112 bool need_rls_dev = false;
2113 unsigned char *addr;
2114 int err, reserve = 0;
2115 struct virtio_net_hdr vnet_hdr = { 0 };
2116 int offset = 0;
2117 int vnet_hdr_len;
2118 struct packet_sock *po = pkt_sk(sk);
2119 unsigned short gso_type = 0;
2120 int hlen, tlen;
2121 int extra_len = 0;
2122
2123 /*
2124 * Get and verify the address.
2125 */
2126
2127 if (saddr == NULL) {
2128 dev = po->prot_hook.dev;
2129 proto = po->num;
2130 addr = NULL;
2131 } else {
2132 err = -EINVAL;
2133 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2134 goto out;
2135 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2136 goto out;
2137 proto = saddr->sll_protocol;
2138 addr = saddr->sll_addr;
2139 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2140 need_rls_dev = true;
2141 }
2142
2143 err = -ENXIO;
2144 if (dev == NULL)
2145 goto out_unlock;
2146 if (sock->type == SOCK_RAW)
2147 reserve = dev->hard_header_len;
2148
2149 err = -ENETDOWN;
2150 if (!(dev->flags & IFF_UP))
2151 goto out_unlock;
2152
2153 if (po->has_vnet_hdr) {
2154 vnet_hdr_len = sizeof(vnet_hdr);
2155
2156 err = -EINVAL;
2157 if (len < vnet_hdr_len)
2158 goto out_unlock;
2159
2160 len -= vnet_hdr_len;
2161
2162 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2163 vnet_hdr_len);
2164 if (err < 0)
2165 goto out_unlock;
2166
2167 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2168 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2169 vnet_hdr.hdr_len))
2170 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2171 vnet_hdr.csum_offset + 2;
2172
2173 err = -EINVAL;
2174 if (vnet_hdr.hdr_len > len)
2175 goto out_unlock;
2176
2177 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2178 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2179 case VIRTIO_NET_HDR_GSO_TCPV4:
2180 gso_type = SKB_GSO_TCPV4;
2181 break;
2182 case VIRTIO_NET_HDR_GSO_TCPV6:
2183 gso_type = SKB_GSO_TCPV6;
2184 break;
2185 case VIRTIO_NET_HDR_GSO_UDP:
2186 gso_type = SKB_GSO_UDP;
2187 break;
2188 default:
2189 goto out_unlock;
2190 }
2191
2192 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2193 gso_type |= SKB_GSO_TCP_ECN;
2194
2195 if (vnet_hdr.gso_size == 0)
2196 goto out_unlock;
2197
2198 }
2199 }
2200
2201 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2202 if (!netif_supports_nofcs(dev)) {
2203 err = -EPROTONOSUPPORT;
2204 goto out_unlock;
2205 }
2206 extra_len = 4; /* We're doing our own CRC */
2207 }
2208
2209 err = -EMSGSIZE;
2210 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2211 goto out_unlock;
2212
2213 err = -ENOBUFS;
2214 hlen = LL_RESERVED_SPACE(dev);
2215 tlen = dev->needed_tailroom;
2216 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2217 msg->msg_flags & MSG_DONTWAIT, &err);
2218 if (skb == NULL)
2219 goto out_unlock;
2220
2221 skb_set_network_header(skb, reserve);
2222
2223 err = -EINVAL;
2224 if (sock->type == SOCK_DGRAM &&
2225 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2226 goto out_free;
2227
2228 /* Returns -EFAULT on error */
2229 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2230 if (err)
2231 goto out_free;
2232 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2233 if (err < 0)
2234 goto out_free;
2235
2236 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2237 /* Earlier code assumed this would be a VLAN pkt,
2238 * double-check this now that we have the actual
2239 * packet in hand.
2240 */
2241 struct ethhdr *ehdr;
2242 skb_reset_mac_header(skb);
2243 ehdr = eth_hdr(skb);
2244 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2245 err = -EMSGSIZE;
2246 goto out_free;
2247 }
2248 }
2249
2250 skb->protocol = proto;
2251 skb->dev = dev;
2252 skb->priority = sk->sk_priority;
2253 skb->mark = sk->sk_mark;
2254
2255 if (po->has_vnet_hdr) {
2256 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2257 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2258 vnet_hdr.csum_offset)) {
2259 err = -EINVAL;
2260 goto out_free;
2261 }
2262 }
2263
2264 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2265 skb_shinfo(skb)->gso_type = gso_type;
2266
2267 /* Header must be checked, and gso_segs computed. */
2268 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2269 skb_shinfo(skb)->gso_segs = 0;
2270
2271 len += vnet_hdr_len;
2272 }
2273
2274 if (unlikely(extra_len == 4))
2275 skb->no_fcs = 1;
2276
2277 /*
2278 * Now send it
2279 */
2280
2281 err = dev_queue_xmit(skb);
2282 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2283 goto out_unlock;
2284
2285 if (need_rls_dev)
2286 dev_put(dev);
2287
2288 return len;
2289
2290out_free:
2291 kfree_skb(skb);
2292out_unlock:
2293 if (dev && need_rls_dev)
2294 dev_put(dev);
2295out:
2296 return err;
2297}
2298
2299static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2300 struct msghdr *msg, size_t len)
2301{
2302 struct sock *sk = sock->sk;
2303 struct packet_sock *po = pkt_sk(sk);
2304 if (po->tx_ring.pg_vec)
2305 return tpacket_snd(po, msg);
2306 else
2307 return packet_snd(sock, msg, len);
2308}
2309
2310/*
2311 * Close a PACKET socket. This is fairly simple. We immediately go
2312 * to 'closed' state and remove our protocol entry in the device list.
2313 */
2314
2315static int packet_release(struct socket *sock)
2316{
2317 struct sock *sk = sock->sk;
2318 struct packet_sock *po;
2319 struct net *net;
2320 union tpacket_req_u req_u;
2321
2322 if (!sk)
2323 return 0;
2324
2325 net = sock_net(sk);
2326 po = pkt_sk(sk);
2327
2328 spin_lock_bh(&net->packet.sklist_lock);
2329 sk_del_node_init_rcu(sk);
2330 sock_prot_inuse_add(net, sk->sk_prot, -1);
2331 spin_unlock_bh(&net->packet.sklist_lock);
2332
2333 spin_lock(&po->bind_lock);
2334 unregister_prot_hook(sk, false);
2335 if (po->prot_hook.dev) {
2336 dev_put(po->prot_hook.dev);
2337 po->prot_hook.dev = NULL;
2338 }
2339 spin_unlock(&po->bind_lock);
2340
2341 packet_flush_mclist(sk);
2342
2343 memset(&req_u, 0, sizeof(req_u));
2344
2345 if (po->rx_ring.pg_vec)
2346 packet_set_ring(sk, &req_u, 1, 0);
2347
2348 if (po->tx_ring.pg_vec)
2349 packet_set_ring(sk, &req_u, 1, 1);
2350
2351 fanout_release(sk);
2352
2353 synchronize_net();
2354 /*
2355 * Now the socket is dead. No more input will appear.
2356 */
2357 sock_orphan(sk);
2358 sock->sk = NULL;
2359
2360 /* Purge queues */
2361
2362 skb_queue_purge(&sk->sk_receive_queue);
2363 sk_refcnt_debug_release(sk);
2364
2365 sock_put(sk);
2366 return 0;
2367}
2368
2369/*
2370 * Attach a packet hook.
2371 */
2372
2373static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2374{
2375 struct packet_sock *po = pkt_sk(sk);
2376
2377 if (po->fanout) {
2378 if (dev)
2379 dev_put(dev);
2380
2381 return -EINVAL;
2382 }
2383
2384 lock_sock(sk);
2385
2386 spin_lock(&po->bind_lock);
2387 unregister_prot_hook(sk, true);
2388 po->num = protocol;
2389 po->prot_hook.type = protocol;
2390 if (po->prot_hook.dev)
2391 dev_put(po->prot_hook.dev);
2392 po->prot_hook.dev = dev;
2393
2394 po->ifindex = dev ? dev->ifindex : 0;
2395
2396 if (protocol == 0)
2397 goto out_unlock;
2398
2399 if (!dev || (dev->flags & IFF_UP)) {
2400 register_prot_hook(sk);
2401 } else {
2402 sk->sk_err = ENETDOWN;
2403 if (!sock_flag(sk, SOCK_DEAD))
2404 sk->sk_error_report(sk);
2405 }
2406
2407out_unlock:
2408 spin_unlock(&po->bind_lock);
2409 release_sock(sk);
2410 return 0;
2411}
2412
2413/*
2414 * Bind a packet socket to a device
2415 */
2416
2417static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2418 int addr_len)
2419{
2420 struct sock *sk = sock->sk;
2421 char name[15];
2422 struct net_device *dev;
2423 int err = -ENODEV;
2424
2425 /*
2426 * Check legality
2427 */
2428
2429 if (addr_len != sizeof(struct sockaddr))
2430 return -EINVAL;
2431 strlcpy(name, uaddr->sa_data, sizeof(name));
2432
2433 dev = dev_get_by_name(sock_net(sk), name);
2434 if (dev)
2435 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2436 return err;
2437}
2438
2439static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2440{
2441 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2442 struct sock *sk = sock->sk;
2443 struct net_device *dev = NULL;
2444 int err;
2445
2446
2447 /*
2448 * Check legality
2449 */
2450
2451 if (addr_len < sizeof(struct sockaddr_ll))
2452 return -EINVAL;
2453 if (sll->sll_family != AF_PACKET)
2454 return -EINVAL;
2455
2456 if (sll->sll_ifindex) {
2457 err = -ENODEV;
2458 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2459 if (dev == NULL)
2460 goto out;
2461 }
2462 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2463
2464out:
2465 return err;
2466}
2467
2468static struct proto packet_proto = {
2469 .name = "PACKET",
2470 .owner = THIS_MODULE,
2471 .obj_size = sizeof(struct packet_sock),
2472};
2473
2474/*
2475 * Create a packet of type SOCK_PACKET.
2476 */
2477
2478static int packet_create(struct net *net, struct socket *sock, int protocol,
2479 int kern)
2480{
2481 struct sock *sk;
2482 struct packet_sock *po;
2483 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2484 int err;
2485
2486 if (!capable(CAP_NET_RAW))
2487 return -EPERM;
2488 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2489 sock->type != SOCK_PACKET)
2490 return -ESOCKTNOSUPPORT;
2491
2492 sock->state = SS_UNCONNECTED;
2493
2494 err = -ENOBUFS;
2495 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2496 if (sk == NULL)
2497 goto out;
2498
2499 sock->ops = &packet_ops;
2500 if (sock->type == SOCK_PACKET)
2501 sock->ops = &packet_ops_spkt;
2502
2503 sock_init_data(sock, sk);
2504
2505 po = pkt_sk(sk);
2506 sk->sk_family = PF_PACKET;
2507 po->num = proto;
2508
2509 sk->sk_destruct = packet_sock_destruct;
2510 sk_refcnt_debug_inc(sk);
2511
2512 /*
2513 * Attach a protocol block
2514 */
2515
2516 spin_lock_init(&po->bind_lock);
2517 mutex_init(&po->pg_vec_lock);
2518 po->prot_hook.func = packet_rcv;
2519
2520 if (sock->type == SOCK_PACKET)
2521 po->prot_hook.func = packet_rcv_spkt;
2522
2523 po->prot_hook.af_packet_priv = sk;
2524
2525 if (proto) {
2526 po->prot_hook.type = proto;
2527 register_prot_hook(sk);
2528 }
2529
2530 spin_lock_bh(&net->packet.sklist_lock);
2531 sk_add_node_rcu(sk, &net->packet.sklist);
2532 sock_prot_inuse_add(net, &packet_proto, 1);
2533 spin_unlock_bh(&net->packet.sklist_lock);
2534
2535 return 0;
2536out:
2537 return err;
2538}
2539
2540static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2541{
2542 struct sock_exterr_skb *serr;
2543 struct sk_buff *skb, *skb2;
2544 int copied, err;
2545
2546 err = -EAGAIN;
2547 skb = skb_dequeue(&sk->sk_error_queue);
2548 if (skb == NULL)
2549 goto out;
2550
2551 copied = skb->len;
2552 if (copied > len) {
2553 msg->msg_flags |= MSG_TRUNC;
2554 copied = len;
2555 }
2556 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2557 if (err)
2558 goto out_free_skb;
2559
2560 sock_recv_timestamp(msg, sk, skb);
2561
2562 serr = SKB_EXT_ERR(skb);
2563 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2564 sizeof(serr->ee), &serr->ee);
2565
2566 msg->msg_flags |= MSG_ERRQUEUE;
2567 err = copied;
2568
2569 /* Reset and regenerate socket error */
2570 spin_lock_bh(&sk->sk_error_queue.lock);
2571 sk->sk_err = 0;
2572 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2573 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2574 spin_unlock_bh(&sk->sk_error_queue.lock);
2575 sk->sk_error_report(sk);
2576 } else
2577 spin_unlock_bh(&sk->sk_error_queue.lock);
2578
2579out_free_skb:
2580 kfree_skb(skb);
2581out:
2582 return err;
2583}
2584
2585/*
2586 * Pull a packet from our receive queue and hand it to the user.
2587 * If necessary we block.
2588 */
2589
2590static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2591 struct msghdr *msg, size_t len, int flags)
2592{
2593 struct sock *sk = sock->sk;
2594 struct sk_buff *skb;
2595 int copied, err;
2596 struct sockaddr_ll *sll;
2597 int vnet_hdr_len = 0;
2598
2599 err = -EINVAL;
2600 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2601 goto out;
2602
2603#if 0
2604 /* What error should we return now? EUNATTACH? */
2605 if (pkt_sk(sk)->ifindex < 0)
2606 return -ENODEV;
2607#endif
2608
2609 if (flags & MSG_ERRQUEUE) {
2610 err = packet_recv_error(sk, msg, len);
2611 goto out;
2612 }
2613
2614 /*
2615 * Call the generic datagram receiver. This handles all sorts
2616 * of horrible races and re-entrancy so we can forget about it
2617 * in the protocol layers.
2618 *
2619 * Now it will return ENETDOWN, if device have just gone down,
2620 * but then it will block.
2621 */
2622
2623 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2624
2625 /*
2626 * An error occurred so return it. Because skb_recv_datagram()
2627 * handles the blocking we don't see and worry about blocking
2628 * retries.
2629 */
2630
2631 if (skb == NULL)
2632 goto out;
2633
2634 if (pkt_sk(sk)->has_vnet_hdr) {
2635 struct virtio_net_hdr vnet_hdr = { 0 };
2636
2637 err = -EINVAL;
2638 vnet_hdr_len = sizeof(vnet_hdr);
2639 if (len < vnet_hdr_len)
2640 goto out_free;
2641
2642 len -= vnet_hdr_len;
2643
2644 if (skb_is_gso(skb)) {
2645 struct skb_shared_info *sinfo = skb_shinfo(skb);
2646
2647 /* This is a hint as to how much should be linear. */
2648 vnet_hdr.hdr_len = skb_headlen(skb);
2649 vnet_hdr.gso_size = sinfo->gso_size;
2650 if (sinfo->gso_type & SKB_GSO_TCPV4)
2651 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2652 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2653 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2654 else if (sinfo->gso_type & SKB_GSO_UDP)
2655 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2656 else if (sinfo->gso_type & SKB_GSO_FCOE)
2657 goto out_free;
2658 else
2659 BUG();
2660 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2661 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2662 } else
2663 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2664
2665 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2666 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2667 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2668 vnet_hdr.csum_offset = skb->csum_offset;
2669 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2670 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2671 } /* else everything is zero */
2672
2673 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2674 vnet_hdr_len);
2675 if (err < 0)
2676 goto out_free;
2677 }
2678
2679 /*
2680 * If the address length field is there to be filled in, we fill
2681 * it in now.
2682 */
2683
2684 sll = &PACKET_SKB_CB(skb)->sa.ll;
2685 if (sock->type == SOCK_PACKET)
2686 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2687 else
2688 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
2689
2690 /*
2691 * You lose any data beyond the buffer you gave. If it worries a
2692 * user program they can ask the device for its MTU anyway.
2693 */
2694
2695 copied = skb->len;
2696 if (copied > len) {
2697 copied = len;
2698 msg->msg_flags |= MSG_TRUNC;
2699 }
2700
2701 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2702 if (err)
2703 goto out_free;
2704
2705 sock_recv_ts_and_drops(msg, sk, skb);
2706
2707 if (msg->msg_name)
2708 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2709 msg->msg_namelen);
2710
2711 if (pkt_sk(sk)->auxdata) {
2712 struct tpacket_auxdata aux;
2713
2714 aux.tp_status = TP_STATUS_USER;
2715 if (skb->ip_summed == CHECKSUM_PARTIAL)
2716 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2717 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2718 aux.tp_snaplen = skb->len;
2719 aux.tp_mac = 0;
2720 aux.tp_net = skb_network_offset(skb);
2721 if (vlan_tx_tag_present(skb)) {
2722 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2723 aux.tp_status |= TP_STATUS_VLAN_VALID;
2724 } else {
2725 aux.tp_vlan_tci = 0;
2726 }
2727 aux.tp_padding = 0;
2728 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2729 }
2730
2731 /*
2732 * Free or return the buffer as appropriate. Again this
2733 * hides all the races and re-entrancy issues from us.
2734 */
2735 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2736
2737out_free:
2738 skb_free_datagram(sk, skb);
2739out:
2740 return err;
2741}
2742
2743static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2744 int *uaddr_len, int peer)
2745{
2746 struct net_device *dev;
2747 struct sock *sk = sock->sk;
2748
2749 if (peer)
2750 return -EOPNOTSUPP;
2751
2752 uaddr->sa_family = AF_PACKET;
2753 rcu_read_lock();
2754 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2755 if (dev)
2756 strncpy(uaddr->sa_data, dev->name, 14);
2757 else
2758 memset(uaddr->sa_data, 0, 14);
2759 rcu_read_unlock();
2760 *uaddr_len = sizeof(*uaddr);
2761
2762 return 0;
2763}
2764
2765static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2766 int *uaddr_len, int peer)
2767{
2768 struct net_device *dev;
2769 struct sock *sk = sock->sk;
2770 struct packet_sock *po = pkt_sk(sk);
2771 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2772
2773 if (peer)
2774 return -EOPNOTSUPP;
2775
2776 sll->sll_family = AF_PACKET;
2777 sll->sll_ifindex = po->ifindex;
2778 sll->sll_protocol = po->num;
2779 sll->sll_pkttype = 0;
2780 rcu_read_lock();
2781 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2782 if (dev) {
2783 sll->sll_hatype = dev->type;
2784 sll->sll_halen = dev->addr_len;
2785 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2786 } else {
2787 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2788 sll->sll_halen = 0;
2789 }
2790 rcu_read_unlock();
2791 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2792
2793 return 0;
2794}
2795
2796static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2797 int what)
2798{
2799 switch (i->type) {
2800 case PACKET_MR_MULTICAST:
2801 if (i->alen != dev->addr_len)
2802 return -EINVAL;
2803 if (what > 0)
2804 return dev_mc_add(dev, i->addr);
2805 else
2806 return dev_mc_del(dev, i->addr);
2807 break;
2808 case PACKET_MR_PROMISC:
2809 return dev_set_promiscuity(dev, what);
2810 break;
2811 case PACKET_MR_ALLMULTI:
2812 return dev_set_allmulti(dev, what);
2813 break;
2814 case PACKET_MR_UNICAST:
2815 if (i->alen != dev->addr_len)
2816 return -EINVAL;
2817 if (what > 0)
2818 return dev_uc_add(dev, i->addr);
2819 else
2820 return dev_uc_del(dev, i->addr);
2821 break;
2822 default:
2823 break;
2824 }
2825 return 0;
2826}
2827
2828static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2829{
2830 for ( ; i; i = i->next) {
2831 if (i->ifindex == dev->ifindex)
2832 packet_dev_mc(dev, i, what);
2833 }
2834}
2835
2836static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2837{
2838 struct packet_sock *po = pkt_sk(sk);
2839 struct packet_mclist *ml, *i;
2840 struct net_device *dev;
2841 int err;
2842
2843 rtnl_lock();
2844
2845 err = -ENODEV;
2846 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2847 if (!dev)
2848 goto done;
2849
2850 err = -EINVAL;
2851 if (mreq->mr_alen > dev->addr_len)
2852 goto done;
2853
2854 err = -ENOBUFS;
2855 i = kmalloc(sizeof(*i), GFP_KERNEL);
2856 if (i == NULL)
2857 goto done;
2858
2859 err = 0;
2860 for (ml = po->mclist; ml; ml = ml->next) {
2861 if (ml->ifindex == mreq->mr_ifindex &&
2862 ml->type == mreq->mr_type &&
2863 ml->alen == mreq->mr_alen &&
2864 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2865 ml->count++;
2866 /* Free the new element ... */
2867 kfree(i);
2868 goto done;
2869 }
2870 }
2871
2872 i->type = mreq->mr_type;
2873 i->ifindex = mreq->mr_ifindex;
2874 i->alen = mreq->mr_alen;
2875 memcpy(i->addr, mreq->mr_address, i->alen);
2876 i->count = 1;
2877 i->next = po->mclist;
2878 po->mclist = i;
2879 err = packet_dev_mc(dev, i, 1);
2880 if (err) {
2881 po->mclist = i->next;
2882 kfree(i);
2883 }
2884
2885done:
2886 rtnl_unlock();
2887 return err;
2888}
2889
2890static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2891{
2892 struct packet_mclist *ml, **mlp;
2893
2894 rtnl_lock();
2895
2896 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2897 if (ml->ifindex == mreq->mr_ifindex &&
2898 ml->type == mreq->mr_type &&
2899 ml->alen == mreq->mr_alen &&
2900 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2901 if (--ml->count == 0) {
2902 struct net_device *dev;
2903 *mlp = ml->next;
2904 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2905 if (dev)
2906 packet_dev_mc(dev, ml, -1);
2907 kfree(ml);
2908 }
2909 rtnl_unlock();
2910 return 0;
2911 }
2912 }
2913 rtnl_unlock();
2914 return -EADDRNOTAVAIL;
2915}
2916
2917static void packet_flush_mclist(struct sock *sk)
2918{
2919 struct packet_sock *po = pkt_sk(sk);
2920 struct packet_mclist *ml;
2921
2922 if (!po->mclist)
2923 return;
2924
2925 rtnl_lock();
2926 while ((ml = po->mclist) != NULL) {
2927 struct net_device *dev;
2928
2929 po->mclist = ml->next;
2930 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2931 if (dev != NULL)
2932 packet_dev_mc(dev, ml, -1);
2933 kfree(ml);
2934 }
2935 rtnl_unlock();
2936}
2937
2938static int
2939packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
2940{
2941 struct sock *sk = sock->sk;
2942 struct packet_sock *po = pkt_sk(sk);
2943 int ret;
2944
2945 if (level != SOL_PACKET)
2946 return -ENOPROTOOPT;
2947
2948 switch (optname) {
2949 case PACKET_ADD_MEMBERSHIP:
2950 case PACKET_DROP_MEMBERSHIP:
2951 {
2952 struct packet_mreq_max mreq;
2953 int len = optlen;
2954 memset(&mreq, 0, sizeof(mreq));
2955 if (len < sizeof(struct packet_mreq))
2956 return -EINVAL;
2957 if (len > sizeof(mreq))
2958 len = sizeof(mreq);
2959 if (copy_from_user(&mreq, optval, len))
2960 return -EFAULT;
2961 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
2962 return -EINVAL;
2963 if (optname == PACKET_ADD_MEMBERSHIP)
2964 ret = packet_mc_add(sk, &mreq);
2965 else
2966 ret = packet_mc_drop(sk, &mreq);
2967 return ret;
2968 }
2969
2970 case PACKET_RX_RING:
2971 case PACKET_TX_RING:
2972 {
2973 union tpacket_req_u req_u;
2974 int len;
2975
2976 switch (po->tp_version) {
2977 case TPACKET_V1:
2978 case TPACKET_V2:
2979 len = sizeof(req_u.req);
2980 break;
2981 case TPACKET_V3:
2982 default:
2983 len = sizeof(req_u.req3);
2984 break;
2985 }
2986 if (optlen < len)
2987 return -EINVAL;
2988 if (pkt_sk(sk)->has_vnet_hdr)
2989 return -EINVAL;
2990 if (copy_from_user(&req_u.req, optval, len))
2991 return -EFAULT;
2992 return packet_set_ring(sk, &req_u, 0,
2993 optname == PACKET_TX_RING);
2994 }
2995 case PACKET_COPY_THRESH:
2996 {
2997 int val;
2998
2999 if (optlen != sizeof(val))
3000 return -EINVAL;
3001 if (copy_from_user(&val, optval, sizeof(val)))
3002 return -EFAULT;
3003
3004 pkt_sk(sk)->copy_thresh = val;
3005 return 0;
3006 }
3007 case PACKET_VERSION:
3008 {
3009 int val;
3010
3011 if (optlen != sizeof(val))
3012 return -EINVAL;
3013 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3014 return -EBUSY;
3015 if (copy_from_user(&val, optval, sizeof(val)))
3016 return -EFAULT;
3017 switch (val) {
3018 case TPACKET_V1:
3019 case TPACKET_V2:
3020 case TPACKET_V3:
3021 po->tp_version = val;
3022 return 0;
3023 default:
3024 return -EINVAL;
3025 }
3026 }
3027 case PACKET_RESERVE:
3028 {
3029 unsigned int val;
3030
3031 if (optlen != sizeof(val))
3032 return -EINVAL;
3033 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3034 return -EBUSY;
3035 if (copy_from_user(&val, optval, sizeof(val)))
3036 return -EFAULT;
3037 po->tp_reserve = val;
3038 return 0;
3039 }
3040 case PACKET_LOSS:
3041 {
3042 unsigned int val;
3043
3044 if (optlen != sizeof(val))
3045 return -EINVAL;
3046 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3047 return -EBUSY;
3048 if (copy_from_user(&val, optval, sizeof(val)))
3049 return -EFAULT;
3050 po->tp_loss = !!val;
3051 return 0;
3052 }
3053 case PACKET_AUXDATA:
3054 {
3055 int val;
3056
3057 if (optlen < sizeof(val))
3058 return -EINVAL;
3059 if (copy_from_user(&val, optval, sizeof(val)))
3060 return -EFAULT;
3061
3062 po->auxdata = !!val;
3063 return 0;
3064 }
3065 case PACKET_ORIGDEV:
3066 {
3067 int val;
3068
3069 if (optlen < sizeof(val))
3070 return -EINVAL;
3071 if (copy_from_user(&val, optval, sizeof(val)))
3072 return -EFAULT;
3073
3074 po->origdev = !!val;
3075 return 0;
3076 }
3077 case PACKET_VNET_HDR:
3078 {
3079 int val;
3080
3081 if (sock->type != SOCK_RAW)
3082 return -EINVAL;
3083 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3084 return -EBUSY;
3085 if (optlen < sizeof(val))
3086 return -EINVAL;
3087 if (copy_from_user(&val, optval, sizeof(val)))
3088 return -EFAULT;
3089
3090 po->has_vnet_hdr = !!val;
3091 return 0;
3092 }
3093 case PACKET_TIMESTAMP:
3094 {
3095 int val;
3096
3097 if (optlen != sizeof(val))
3098 return -EINVAL;
3099 if (copy_from_user(&val, optval, sizeof(val)))
3100 return -EFAULT;
3101
3102 po->tp_tstamp = val;
3103 return 0;
3104 }
3105 case PACKET_FANOUT:
3106 {
3107 int val;
3108
3109 if (optlen != sizeof(val))
3110 return -EINVAL;
3111 if (copy_from_user(&val, optval, sizeof(val)))
3112 return -EFAULT;
3113
3114 return fanout_add(sk, val & 0xffff, val >> 16);
3115 }
3116 default:
3117 return -ENOPROTOOPT;
3118 }
3119}
3120
3121static int packet_getsockopt(struct socket *sock, int level, int optname,
3122 char __user *optval, int __user *optlen)
3123{
3124 int len;
3125 int val, lv = sizeof(val);
3126 struct sock *sk = sock->sk;
3127 struct packet_sock *po = pkt_sk(sk);
3128 void *data = &val;
3129 struct tpacket_stats st;
3130 union tpacket_stats_u st_u;
3131
3132 if (level != SOL_PACKET)
3133 return -ENOPROTOOPT;
3134
3135 if (get_user(len, optlen))
3136 return -EFAULT;
3137
3138 if (len < 0)
3139 return -EINVAL;
3140
3141 switch (optname) {
3142 case PACKET_STATISTICS:
3143 spin_lock_bh(&sk->sk_receive_queue.lock);
3144 if (po->tp_version == TPACKET_V3) {
3145 lv = sizeof(struct tpacket_stats_v3);
3146 memcpy(&st_u.stats3, &po->stats,
3147 sizeof(struct tpacket_stats));
3148 st_u.stats3.tp_freeze_q_cnt =
3149 po->stats_u.stats3.tp_freeze_q_cnt;
3150 st_u.stats3.tp_packets += po->stats.tp_drops;
3151 data = &st_u.stats3;
3152 } else {
3153 lv = sizeof(struct tpacket_stats);
3154 st = po->stats;
3155 st.tp_packets += st.tp_drops;
3156 data = &st;
3157 }
3158 memset(&po->stats, 0, sizeof(st));
3159 spin_unlock_bh(&sk->sk_receive_queue.lock);
3160 break;
3161 case PACKET_AUXDATA:
3162 val = po->auxdata;
3163 break;
3164 case PACKET_ORIGDEV:
3165 val = po->origdev;
3166 break;
3167 case PACKET_VNET_HDR:
3168 val = po->has_vnet_hdr;
3169 break;
3170 case PACKET_VERSION:
3171 val = po->tp_version;
3172 break;
3173 case PACKET_HDRLEN:
3174 if (len > sizeof(int))
3175 len = sizeof(int);
3176 if (copy_from_user(&val, optval, len))
3177 return -EFAULT;
3178 switch (val) {
3179 case TPACKET_V1:
3180 val = sizeof(struct tpacket_hdr);
3181 break;
3182 case TPACKET_V2:
3183 val = sizeof(struct tpacket2_hdr);
3184 break;
3185 case TPACKET_V3:
3186 val = sizeof(struct tpacket3_hdr);
3187 break;
3188 default:
3189 return -EINVAL;
3190 }
3191 break;
3192 case PACKET_RESERVE:
3193 val = po->tp_reserve;
3194 break;
3195 case PACKET_LOSS:
3196 val = po->tp_loss;
3197 break;
3198 case PACKET_TIMESTAMP:
3199 val = po->tp_tstamp;
3200 break;
3201 case PACKET_FANOUT:
3202 val = (po->fanout ?
3203 ((u32)po->fanout->id |
3204 ((u32)po->fanout->type << 16)) :
3205 0);
3206 break;
3207 default:
3208 return -ENOPROTOOPT;
3209 }
3210
3211 if (len > lv)
3212 len = lv;
3213 if (put_user(len, optlen))
3214 return -EFAULT;
3215 if (copy_to_user(optval, data, len))
3216 return -EFAULT;
3217 return 0;
3218}
3219
3220
3221static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3222{
3223 struct sock *sk;
3224 struct hlist_node *node;
3225 struct net_device *dev = data;
3226 struct net *net = dev_net(dev);
3227
3228 rcu_read_lock();
3229 sk_for_each_rcu(sk, node, &net->packet.sklist) {
3230 struct packet_sock *po = pkt_sk(sk);
3231
3232 switch (msg) {
3233 case NETDEV_UNREGISTER:
3234 if (po->mclist)
3235 packet_dev_mclist(dev, po->mclist, -1);
3236 /* fallthrough */
3237
3238 case NETDEV_DOWN:
3239 if (dev->ifindex == po->ifindex) {
3240 spin_lock(&po->bind_lock);
3241 if (po->running) {
3242 __unregister_prot_hook(sk, false);
3243 sk->sk_err = ENETDOWN;
3244 if (!sock_flag(sk, SOCK_DEAD))
3245 sk->sk_error_report(sk);
3246 }
3247 if (msg == NETDEV_UNREGISTER) {
3248 po->ifindex = -1;
3249 if (po->prot_hook.dev)
3250 dev_put(po->prot_hook.dev);
3251 po->prot_hook.dev = NULL;
3252 }
3253 spin_unlock(&po->bind_lock);
3254 }
3255 break;
3256 case NETDEV_UP:
3257 if (dev->ifindex == po->ifindex) {
3258 spin_lock(&po->bind_lock);
3259 if (po->num)
3260 register_prot_hook(sk);
3261 spin_unlock(&po->bind_lock);
3262 }
3263 break;
3264 }
3265 }
3266 rcu_read_unlock();
3267 return NOTIFY_DONE;
3268}
3269
3270
3271static int packet_ioctl(struct socket *sock, unsigned int cmd,
3272 unsigned long arg)
3273{
3274 struct sock *sk = sock->sk;
3275
3276 switch (cmd) {
3277 case SIOCOUTQ:
3278 {
3279 int amount = sk_wmem_alloc_get(sk);
3280
3281 return put_user(amount, (int __user *)arg);
3282 }
3283 case SIOCINQ:
3284 {
3285 struct sk_buff *skb;
3286 int amount = 0;
3287
3288 spin_lock_bh(&sk->sk_receive_queue.lock);
3289 skb = skb_peek(&sk->sk_receive_queue);
3290 if (skb)
3291 amount = skb->len;
3292 spin_unlock_bh(&sk->sk_receive_queue.lock);
3293 return put_user(amount, (int __user *)arg);
3294 }
3295 case SIOCGSTAMP:
3296 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3297 case SIOCGSTAMPNS:
3298 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3299
3300#ifdef CONFIG_INET
3301 case SIOCADDRT:
3302 case SIOCDELRT:
3303 case SIOCDARP:
3304 case SIOCGARP:
3305 case SIOCSARP:
3306 case SIOCGIFADDR:
3307 case SIOCSIFADDR:
3308 case SIOCGIFBRDADDR:
3309 case SIOCSIFBRDADDR:
3310 case SIOCGIFNETMASK:
3311 case SIOCSIFNETMASK:
3312 case SIOCGIFDSTADDR:
3313 case SIOCSIFDSTADDR:
3314 case SIOCSIFFLAGS:
3315 return inet_dgram_ops.ioctl(sock, cmd, arg);
3316#endif
3317
3318 default:
3319 return -ENOIOCTLCMD;
3320 }
3321 return 0;
3322}
3323
3324static unsigned int packet_poll(struct file *file, struct socket *sock,
3325 poll_table *wait)
3326{
3327 struct sock *sk = sock->sk;
3328 struct packet_sock *po = pkt_sk(sk);
3329 unsigned int mask = datagram_poll(file, sock, wait);
3330
3331 spin_lock_bh(&sk->sk_receive_queue.lock);
3332 if (po->rx_ring.pg_vec) {
3333 if (!packet_previous_rx_frame(po, &po->rx_ring,
3334 TP_STATUS_KERNEL))
3335 mask |= POLLIN | POLLRDNORM;
3336 }
3337 spin_unlock_bh(&sk->sk_receive_queue.lock);
3338 spin_lock_bh(&sk->sk_write_queue.lock);
3339 if (po->tx_ring.pg_vec) {
3340 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3341 mask |= POLLOUT | POLLWRNORM;
3342 }
3343 spin_unlock_bh(&sk->sk_write_queue.lock);
3344 return mask;
3345}
3346
3347
3348/* Dirty? Well, I still did not learn better way to account
3349 * for user mmaps.
3350 */
3351
3352static void packet_mm_open(struct vm_area_struct *vma)
3353{
3354 struct file *file = vma->vm_file;
3355 struct socket *sock = file->private_data;
3356 struct sock *sk = sock->sk;
3357
3358 if (sk)
3359 atomic_inc(&pkt_sk(sk)->mapped);
3360}
3361
3362static void packet_mm_close(struct vm_area_struct *vma)
3363{
3364 struct file *file = vma->vm_file;
3365 struct socket *sock = file->private_data;
3366 struct sock *sk = sock->sk;
3367
3368 if (sk)
3369 atomic_dec(&pkt_sk(sk)->mapped);
3370}
3371
3372static const struct vm_operations_struct packet_mmap_ops = {
3373 .open = packet_mm_open,
3374 .close = packet_mm_close,
3375};
3376
3377static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3378 unsigned int len)
3379{
3380 int i;
3381
3382 for (i = 0; i < len; i++) {
3383 if (likely(pg_vec[i].buffer)) {
3384 if (is_vmalloc_addr(pg_vec[i].buffer))
3385 vfree(pg_vec[i].buffer);
3386 else
3387 free_pages((unsigned long)pg_vec[i].buffer,
3388 order);
3389 pg_vec[i].buffer = NULL;
3390 }
3391 }
3392 kfree(pg_vec);
3393}
3394
3395static char *alloc_one_pg_vec_page(unsigned long order)
3396{
3397 char *buffer = NULL;
3398 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3399 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3400
3401 buffer = (char *) __get_free_pages(gfp_flags, order);
3402
3403 if (buffer)
3404 return buffer;
3405
3406 /*
3407 * __get_free_pages failed, fall back to vmalloc
3408 */
3409 buffer = vzalloc((1 << order) * PAGE_SIZE);
3410
3411 if (buffer)
3412 return buffer;
3413
3414 /*
3415 * vmalloc failed, lets dig into swap here
3416 */
3417 gfp_flags &= ~__GFP_NORETRY;
3418 buffer = (char *)__get_free_pages(gfp_flags, order);
3419 if (buffer)
3420 return buffer;
3421
3422 /*
3423 * complete and utter failure
3424 */
3425 return NULL;
3426}
3427
3428static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3429{
3430 unsigned int block_nr = req->tp_block_nr;
3431 struct pgv *pg_vec;
3432 int i;
3433
3434 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3435 if (unlikely(!pg_vec))
3436 goto out;
3437
3438 for (i = 0; i < block_nr; i++) {
3439 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3440 if (unlikely(!pg_vec[i].buffer))
3441 goto out_free_pgvec;
3442 }
3443
3444out:
3445 return pg_vec;
3446
3447out_free_pgvec:
3448 free_pg_vec(pg_vec, order, block_nr);
3449 pg_vec = NULL;
3450 goto out;
3451}
3452
3453static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3454 int closing, int tx_ring)
3455{
3456 struct pgv *pg_vec = NULL;
3457 struct packet_sock *po = pkt_sk(sk);
3458 int was_running, order = 0;
3459 struct packet_ring_buffer *rb;
3460 struct sk_buff_head *rb_queue;
3461 __be16 num;
3462 int err = -EINVAL;
3463 /* Added to avoid minimal code churn */
3464 struct tpacket_req *req = &req_u->req;
3465
3466 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3467 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3468 WARN(1, "Tx-ring is not supported.\n");
3469 goto out;
3470 }
3471
3472 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3473 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3474
3475 err = -EBUSY;
3476 if (!closing) {
3477 if (atomic_read(&po->mapped))
3478 goto out;
3479 if (atomic_read(&rb->pending))
3480 goto out;
3481 }
3482
3483 if (req->tp_block_nr) {
3484 /* Sanity tests and some calculations */
3485 err = -EBUSY;
3486 if (unlikely(rb->pg_vec))
3487 goto out;
3488
3489 switch (po->tp_version) {
3490 case TPACKET_V1:
3491 po->tp_hdrlen = TPACKET_HDRLEN;
3492 break;
3493 case TPACKET_V2:
3494 po->tp_hdrlen = TPACKET2_HDRLEN;
3495 break;
3496 case TPACKET_V3:
3497 po->tp_hdrlen = TPACKET3_HDRLEN;
3498 break;
3499 }
3500
3501 err = -EINVAL;
3502 if (unlikely((int)req->tp_block_size <= 0))
3503 goto out;
3504 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3505 goto out;
3506 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3507 po->tp_reserve))
3508 goto out;
3509 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3510 goto out;
3511
3512 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3513 if (unlikely(rb->frames_per_block <= 0))
3514 goto out;
3515 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3516 req->tp_frame_nr))
3517 goto out;
3518
3519 err = -ENOMEM;
3520 order = get_order(req->tp_block_size);
3521 pg_vec = alloc_pg_vec(req, order);
3522 if (unlikely(!pg_vec))
3523 goto out;
3524 switch (po->tp_version) {
3525 case TPACKET_V3:
3526 /* Transmit path is not supported. We checked
3527 * it above but just being paranoid
3528 */
3529 if (!tx_ring)
3530 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3531 break;
3532 default:
3533 break;
3534 }
3535 }
3536 /* Done */
3537 else {
3538 err = -EINVAL;
3539 if (unlikely(req->tp_frame_nr))
3540 goto out;
3541 }
3542
3543 lock_sock(sk);
3544
3545 /* Detach socket from network */
3546 spin_lock(&po->bind_lock);
3547 was_running = po->running;
3548 num = po->num;
3549 if (was_running) {
3550 po->num = 0;
3551 __unregister_prot_hook(sk, false);
3552 }
3553 spin_unlock(&po->bind_lock);
3554
3555 synchronize_net();
3556
3557 err = -EBUSY;
3558 mutex_lock(&po->pg_vec_lock);
3559 if (closing || atomic_read(&po->mapped) == 0) {
3560 err = 0;
3561 spin_lock_bh(&rb_queue->lock);
3562 swap(rb->pg_vec, pg_vec);
3563 rb->frame_max = (req->tp_frame_nr - 1);
3564 rb->head = 0;
3565 rb->frame_size = req->tp_frame_size;
3566 spin_unlock_bh(&rb_queue->lock);
3567
3568 swap(rb->pg_vec_order, order);
3569 swap(rb->pg_vec_len, req->tp_block_nr);
3570
3571 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3572 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3573 tpacket_rcv : packet_rcv;
3574 skb_queue_purge(rb_queue);
3575 if (atomic_read(&po->mapped))
3576 pr_err("packet_mmap: vma is busy: %d\n",
3577 atomic_read(&po->mapped));
3578 }
3579 mutex_unlock(&po->pg_vec_lock);
3580
3581 spin_lock(&po->bind_lock);
3582 if (was_running) {
3583 po->num = num;
3584 register_prot_hook(sk);
3585 }
3586 spin_unlock(&po->bind_lock);
3587 if (closing && (po->tp_version > TPACKET_V2)) {
3588 /* Because we don't support block-based V3 on tx-ring */
3589 if (!tx_ring)
3590 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3591 }
3592 release_sock(sk);
3593
3594 if (pg_vec)
3595 free_pg_vec(pg_vec, order, req->tp_block_nr);
3596out:
3597 return err;
3598}
3599
3600static int packet_mmap(struct file *file, struct socket *sock,
3601 struct vm_area_struct *vma)
3602{
3603 struct sock *sk = sock->sk;
3604 struct packet_sock *po = pkt_sk(sk);
3605 unsigned long size, expected_size;
3606 struct packet_ring_buffer *rb;
3607 unsigned long start;
3608 int err = -EINVAL;
3609 int i;
3610
3611 if (vma->vm_pgoff)
3612 return -EINVAL;
3613
3614 mutex_lock(&po->pg_vec_lock);
3615
3616 expected_size = 0;
3617 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3618 if (rb->pg_vec) {
3619 expected_size += rb->pg_vec_len
3620 * rb->pg_vec_pages
3621 * PAGE_SIZE;
3622 }
3623 }
3624
3625 if (expected_size == 0)
3626 goto out;
3627
3628 size = vma->vm_end - vma->vm_start;
3629 if (size != expected_size)
3630 goto out;
3631
3632 start = vma->vm_start;
3633 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3634 if (rb->pg_vec == NULL)
3635 continue;
3636
3637 for (i = 0; i < rb->pg_vec_len; i++) {
3638 struct page *page;
3639 void *kaddr = rb->pg_vec[i].buffer;
3640 int pg_num;
3641
3642 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3643 page = pgv_to_page(kaddr);
3644 err = vm_insert_page(vma, start, page);
3645 if (unlikely(err))
3646 goto out;
3647 start += PAGE_SIZE;
3648 kaddr += PAGE_SIZE;
3649 }
3650 }
3651 }
3652
3653 atomic_inc(&po->mapped);
3654 vma->vm_ops = &packet_mmap_ops;
3655 err = 0;
3656
3657out:
3658 mutex_unlock(&po->pg_vec_lock);
3659 return err;
3660}
3661
3662static const struct proto_ops packet_ops_spkt = {
3663 .family = PF_PACKET,
3664 .owner = THIS_MODULE,
3665 .release = packet_release,
3666 .bind = packet_bind_spkt,
3667 .connect = sock_no_connect,
3668 .socketpair = sock_no_socketpair,
3669 .accept = sock_no_accept,
3670 .getname = packet_getname_spkt,
3671 .poll = datagram_poll,
3672 .ioctl = packet_ioctl,
3673 .listen = sock_no_listen,
3674 .shutdown = sock_no_shutdown,
3675 .setsockopt = sock_no_setsockopt,
3676 .getsockopt = sock_no_getsockopt,
3677 .sendmsg = packet_sendmsg_spkt,
3678 .recvmsg = packet_recvmsg,
3679 .mmap = sock_no_mmap,
3680 .sendpage = sock_no_sendpage,
3681};
3682
3683static const struct proto_ops packet_ops = {
3684 .family = PF_PACKET,
3685 .owner = THIS_MODULE,
3686 .release = packet_release,
3687 .bind = packet_bind,
3688 .connect = sock_no_connect,
3689 .socketpair = sock_no_socketpair,
3690 .accept = sock_no_accept,
3691 .getname = packet_getname,
3692 .poll = packet_poll,
3693 .ioctl = packet_ioctl,
3694 .listen = sock_no_listen,
3695 .shutdown = sock_no_shutdown,
3696 .setsockopt = packet_setsockopt,
3697 .getsockopt = packet_getsockopt,
3698 .sendmsg = packet_sendmsg,
3699 .recvmsg = packet_recvmsg,
3700 .mmap = packet_mmap,
3701 .sendpage = sock_no_sendpage,
3702};
3703
3704static const struct net_proto_family packet_family_ops = {
3705 .family = PF_PACKET,
3706 .create = packet_create,
3707 .owner = THIS_MODULE,
3708};
3709
3710static struct notifier_block packet_netdev_notifier = {
3711 .notifier_call = packet_notifier,
3712};
3713
3714#ifdef CONFIG_PROC_FS
3715
3716static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3717 __acquires(RCU)
3718{
3719 struct net *net = seq_file_net(seq);
3720
3721 rcu_read_lock();
3722 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3723}
3724
3725static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3726{
3727 struct net *net = seq_file_net(seq);
3728 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3729}
3730
3731static void packet_seq_stop(struct seq_file *seq, void *v)
3732 __releases(RCU)
3733{
3734 rcu_read_unlock();
3735}
3736
3737static int packet_seq_show(struct seq_file *seq, void *v)
3738{
3739 if (v == SEQ_START_TOKEN)
3740 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3741 else {
3742 struct sock *s = sk_entry(v);
3743 const struct packet_sock *po = pkt_sk(s);
3744
3745 seq_printf(seq,
3746 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3747 s,
3748 atomic_read(&s->sk_refcnt),
3749 s->sk_type,
3750 ntohs(po->num),
3751 po->ifindex,
3752 po->running,
3753 atomic_read(&s->sk_rmem_alloc),
3754 sock_i_uid(s),
3755 sock_i_ino(s));
3756 }
3757
3758 return 0;
3759}
3760
3761static const struct seq_operations packet_seq_ops = {
3762 .start = packet_seq_start,
3763 .next = packet_seq_next,
3764 .stop = packet_seq_stop,
3765 .show = packet_seq_show,
3766};
3767
3768static int packet_seq_open(struct inode *inode, struct file *file)
3769{
3770 return seq_open_net(inode, file, &packet_seq_ops,
3771 sizeof(struct seq_net_private));
3772}
3773
3774static const struct file_operations packet_seq_fops = {
3775 .owner = THIS_MODULE,
3776 .open = packet_seq_open,
3777 .read = seq_read,
3778 .llseek = seq_lseek,
3779 .release = seq_release_net,
3780};
3781
3782#endif
3783
3784static int __net_init packet_net_init(struct net *net)
3785{
3786 spin_lock_init(&net->packet.sklist_lock);
3787 INIT_HLIST_HEAD(&net->packet.sklist);
3788
3789 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
3790 return -ENOMEM;
3791
3792 return 0;
3793}
3794
3795static void __net_exit packet_net_exit(struct net *net)
3796{
3797 proc_net_remove(net, "packet");
3798}
3799
3800static struct pernet_operations packet_net_ops = {
3801 .init = packet_net_init,
3802 .exit = packet_net_exit,
3803};
3804
3805
3806static void __exit packet_exit(void)
3807{
3808 unregister_netdevice_notifier(&packet_netdev_notifier);
3809 unregister_pernet_subsys(&packet_net_ops);
3810 sock_unregister(PF_PACKET);
3811 proto_unregister(&packet_proto);
3812}
3813
3814static int __init packet_init(void)
3815{
3816 int rc = proto_register(&packet_proto, 0);
3817
3818 if (rc != 0)
3819 goto out;
3820
3821 sock_register(&packet_family_ops);
3822 register_pernet_subsys(&packet_net_ops);
3823 register_netdevice_notifier(&packet_netdev_notifier);
3824out:
3825 return rc;
3826}
3827
3828module_init(packet_init);
3829module_exit(packet_exit);
3830MODULE_LICENSE("GPL");
3831MODULE_ALIAS_NETPROTO(PF_PACKET);
Linux kernel - Deliverables
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