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Merge tag 'asoc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound...
[deliverable/linux.git] / net / packet / af_packet.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PACKET - implements raw packet sockets.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 *
12 * Fixes:
13 * Alan Cox : verify_area() now used correctly
14 * Alan Cox : new skbuff lists, look ma no backlogs!
15 * Alan Cox : tidied skbuff lists.
16 * Alan Cox : Now uses generic datagram routines I
17 * added. Also fixed the peek/read crash
18 * from all old Linux datagram code.
19 * Alan Cox : Uses the improved datagram code.
20 * Alan Cox : Added NULL's for socket options.
21 * Alan Cox : Re-commented the code.
22 * Alan Cox : Use new kernel side addressing
23 * Rob Janssen : Correct MTU usage.
24 * Dave Platt : Counter leaks caused by incorrect
25 * interrupt locking and some slightly
26 * dubious gcc output. Can you read
27 * compiler: it said _VOLATILE_
28 * Richard Kooijman : Timestamp fixes.
29 * Alan Cox : New buffers. Use sk->mac.raw.
30 * Alan Cox : sendmsg/recvmsg support.
31 * Alan Cox : Protocol setting support
32 * Alexey Kuznetsov : Untied from IPv4 stack.
33 * Cyrus Durgin : Fixed kerneld for kmod.
34 * Michal Ostrowski : Module initialization cleanup.
35 * Ulises Alonso : Frame number limit removal and
36 * packet_set_ring memory leak.
37 * Eric Biederman : Allow for > 8 byte hardware addresses.
38 * The convention is that longer addresses
39 * will simply extend the hardware address
40 * byte arrays at the end of sockaddr_ll
41 * and packet_mreq.
42 * Johann Baudy : Added TX RING.
43 * Chetan Loke : Implemented TPACKET_V3 block abstraction
44 * layer.
45 * Copyright (C) 2011, <lokec@ccs.neu.edu>
46 *
47 *
48 * This program is free software; you can redistribute it and/or
49 * modify it under the terms of the GNU General Public License
50 * as published by the Free Software Foundation; either version
51 * 2 of the License, or (at your option) any later version.
52 *
53 */
54
55 #include <linux/types.h>
56 #include <linux/mm.h>
57 #include <linux/capability.h>
58 #include <linux/fcntl.h>
59 #include <linux/socket.h>
60 #include <linux/in.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/if_packet.h>
64 #include <linux/wireless.h>
65 #include <linux/kernel.h>
66 #include <linux/kmod.h>
67 #include <linux/slab.h>
68 #include <linux/vmalloc.h>
69 #include <net/net_namespace.h>
70 #include <net/ip.h>
71 #include <net/protocol.h>
72 #include <linux/skbuff.h>
73 #include <net/sock.h>
74 #include <linux/errno.h>
75 #include <linux/timer.h>
76 #include <asm/uaccess.h>
77 #include <asm/ioctls.h>
78 #include <asm/page.h>
79 #include <asm/cacheflush.h>
80 #include <asm/io.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83 #include <linux/poll.h>
84 #include <linux/module.h>
85 #include <linux/init.h>
86 #include <linux/mutex.h>
87 #include <linux/if_vlan.h>
88 #include <linux/virtio_net.h>
89 #include <linux/errqueue.h>
90 #include <linux/net_tstamp.h>
91
92 #ifdef CONFIG_INET
93 #include <net/inet_common.h>
94 #endif
95
96 /*
97 Assumptions:
98 - if device has no dev->hard_header routine, it adds and removes ll header
99 inside itself. In this case ll header is invisible outside of device,
100 but higher levels still should reserve dev->hard_header_len.
101 Some devices are enough clever to reallocate skb, when header
102 will not fit to reserved space (tunnel), another ones are silly
103 (PPP).
104 - packet socket receives packets with pulled ll header,
105 so that SOCK_RAW should push it back.
106
107 On receive:
108 -----------
109
110 Incoming, dev->hard_header!=NULL
111 mac_header -> ll header
112 data -> data
113
114 Outgoing, dev->hard_header!=NULL
115 mac_header -> ll header
116 data -> ll header
117
118 Incoming, dev->hard_header==NULL
119 mac_header -> UNKNOWN position. It is very likely, that it points to ll
120 header. PPP makes it, that is wrong, because introduce
121 assymetry between rx and tx paths.
122 data -> data
123
124 Outgoing, dev->hard_header==NULL
125 mac_header -> data. ll header is still not built!
126 data -> data
127
128 Resume
129 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
130
131
132 On transmit:
133 ------------
134
135 dev->hard_header != NULL
136 mac_header -> ll header
137 data -> ll header
138
139 dev->hard_header == NULL (ll header is added by device, we cannot control it)
140 mac_header -> data
141 data -> data
142
143 We should set nh.raw on output to correct posistion,
144 packet classifier depends on it.
145 */
146
147 /* Private packet socket structures. */
148
149 struct packet_mclist {
150 struct packet_mclist *next;
151 int ifindex;
152 int count;
153 unsigned short type;
154 unsigned short alen;
155 unsigned char addr[MAX_ADDR_LEN];
156 };
157 /* identical to struct packet_mreq except it has
158 * a longer address field.
159 */
160 struct packet_mreq_max {
161 int mr_ifindex;
162 unsigned short mr_type;
163 unsigned short mr_alen;
164 unsigned char mr_address[MAX_ADDR_LEN];
165 };
166
167 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
168 int closing, int tx_ring);
169
170
171 #define V3_ALIGNMENT (8)
172
173 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
174
175 #define BLK_PLUS_PRIV(sz_of_priv) \
176 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
177
178 /* kbdq - kernel block descriptor queue */
179 struct tpacket_kbdq_core {
180 struct pgv *pkbdq;
181 unsigned int feature_req_word;
182 unsigned int hdrlen;
183 unsigned char reset_pending_on_curr_blk;
184 unsigned char delete_blk_timer;
185 unsigned short kactive_blk_num;
186 unsigned short blk_sizeof_priv;
187
188 /* last_kactive_blk_num:
189 * trick to see if user-space has caught up
190 * in order to avoid refreshing timer when every single pkt arrives.
191 */
192 unsigned short last_kactive_blk_num;
193
194 char *pkblk_start;
195 char *pkblk_end;
196 int kblk_size;
197 unsigned int knum_blocks;
198 uint64_t knxt_seq_num;
199 char *prev;
200 char *nxt_offset;
201 struct sk_buff *skb;
202
203 atomic_t blk_fill_in_prog;
204
205 /* Default is set to 8ms */
206 #define DEFAULT_PRB_RETIRE_TOV (8)
207
208 unsigned short retire_blk_tov;
209 unsigned short version;
210 unsigned long tov_in_jiffies;
211
212 /* timer to retire an outstanding block */
213 struct timer_list retire_blk_timer;
214 };
215
216 #define PGV_FROM_VMALLOC 1
217 struct pgv {
218 char *buffer;
219 };
220
221 struct packet_ring_buffer {
222 struct pgv *pg_vec;
223 unsigned int head;
224 unsigned int frames_per_block;
225 unsigned int frame_size;
226 unsigned int frame_max;
227
228 unsigned int pg_vec_order;
229 unsigned int pg_vec_pages;
230 unsigned int pg_vec_len;
231
232 struct tpacket_kbdq_core prb_bdqc;
233 atomic_t pending;
234 };
235
236 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
237 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
238 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
239 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
240 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
241 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
242 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
243
244 struct packet_sock;
245 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
246
247 static void *packet_previous_frame(struct packet_sock *po,
248 struct packet_ring_buffer *rb,
249 int status);
250 static void packet_increment_head(struct packet_ring_buffer *buff);
251 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
252 struct tpacket_block_desc *);
253 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
254 struct packet_sock *);
255 static void prb_retire_current_block(struct tpacket_kbdq_core *,
256 struct packet_sock *, unsigned int status);
257 static int prb_queue_frozen(struct tpacket_kbdq_core *);
258 static void prb_open_block(struct tpacket_kbdq_core *,
259 struct tpacket_block_desc *);
260 static void prb_retire_rx_blk_timer_expired(unsigned long);
261 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
262 static void prb_init_blk_timer(struct packet_sock *,
263 struct tpacket_kbdq_core *,
264 void (*func) (unsigned long));
265 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
266 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
267 struct tpacket3_hdr *);
268 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
269 struct tpacket3_hdr *);
270 static void packet_flush_mclist(struct sock *sk);
271
272 struct packet_fanout;
273 struct packet_sock {
274 /* struct sock has to be the first member of packet_sock */
275 struct sock sk;
276 struct packet_fanout *fanout;
277 struct tpacket_stats stats;
278 union tpacket_stats_u stats_u;
279 struct packet_ring_buffer rx_ring;
280 struct packet_ring_buffer tx_ring;
281 int copy_thresh;
282 spinlock_t bind_lock;
283 struct mutex pg_vec_lock;
284 unsigned int running:1, /* prot_hook is attached*/
285 auxdata:1,
286 origdev:1,
287 has_vnet_hdr:1;
288 int ifindex; /* bound device */
289 __be16 num;
290 struct packet_mclist *mclist;
291 atomic_t mapped;
292 enum tpacket_versions tp_version;
293 unsigned int tp_hdrlen;
294 unsigned int tp_reserve;
295 unsigned int tp_loss:1;
296 unsigned int tp_tstamp;
297 struct packet_type prot_hook ____cacheline_aligned_in_smp;
298 };
299
300 #define PACKET_FANOUT_MAX 256
301
302 struct packet_fanout {
303 #ifdef CONFIG_NET_NS
304 struct net *net;
305 #endif
306 unsigned int num_members;
307 u16 id;
308 u8 type;
309 u8 defrag;
310 atomic_t rr_cur;
311 struct list_head list;
312 struct sock *arr[PACKET_FANOUT_MAX];
313 spinlock_t lock;
314 atomic_t sk_ref;
315 struct packet_type prot_hook ____cacheline_aligned_in_smp;
316 };
317
318 struct packet_skb_cb {
319 unsigned int origlen;
320 union {
321 struct sockaddr_pkt pkt;
322 struct sockaddr_ll ll;
323 } sa;
324 };
325
326 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
327
328 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
329 #define GET_PBLOCK_DESC(x, bid) \
330 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
331 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
332 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
333 #define GET_NEXT_PRB_BLK_NUM(x) \
334 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
335 ((x)->kactive_blk_num+1) : 0)
336
337 static struct packet_sock *pkt_sk(struct sock *sk)
338 {
339 return (struct packet_sock *)sk;
340 }
341
342 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
343 static void __fanout_link(struct sock *sk, struct packet_sock *po);
344
345 /* register_prot_hook must be invoked with the po->bind_lock held,
346 * or from a context in which asynchronous accesses to the packet
347 * socket is not possible (packet_create()).
348 */
349 static void register_prot_hook(struct sock *sk)
350 {
351 struct packet_sock *po = pkt_sk(sk);
352 if (!po->running) {
353 if (po->fanout)
354 __fanout_link(sk, po);
355 else
356 dev_add_pack(&po->prot_hook);
357 sock_hold(sk);
358 po->running = 1;
359 }
360 }
361
362 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
363 * held. If the sync parameter is true, we will temporarily drop
364 * the po->bind_lock and do a synchronize_net to make sure no
365 * asynchronous packet processing paths still refer to the elements
366 * of po->prot_hook. If the sync parameter is false, it is the
367 * callers responsibility to take care of this.
368 */
369 static void __unregister_prot_hook(struct sock *sk, bool sync)
370 {
371 struct packet_sock *po = pkt_sk(sk);
372
373 po->running = 0;
374 if (po->fanout)
375 __fanout_unlink(sk, po);
376 else
377 __dev_remove_pack(&po->prot_hook);
378 __sock_put(sk);
379
380 if (sync) {
381 spin_unlock(&po->bind_lock);
382 synchronize_net();
383 spin_lock(&po->bind_lock);
384 }
385 }
386
387 static void unregister_prot_hook(struct sock *sk, bool sync)
388 {
389 struct packet_sock *po = pkt_sk(sk);
390
391 if (po->running)
392 __unregister_prot_hook(sk, sync);
393 }
394
395 static inline __pure struct page *pgv_to_page(void *addr)
396 {
397 if (is_vmalloc_addr(addr))
398 return vmalloc_to_page(addr);
399 return virt_to_page(addr);
400 }
401
402 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
403 {
404 union {
405 struct tpacket_hdr *h1;
406 struct tpacket2_hdr *h2;
407 void *raw;
408 } h;
409
410 h.raw = frame;
411 switch (po->tp_version) {
412 case TPACKET_V1:
413 h.h1->tp_status = status;
414 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
415 break;
416 case TPACKET_V2:
417 h.h2->tp_status = status;
418 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
419 break;
420 case TPACKET_V3:
421 default:
422 WARN(1, "TPACKET version not supported.\n");
423 BUG();
424 }
425
426 smp_wmb();
427 }
428
429 static int __packet_get_status(struct packet_sock *po, void *frame)
430 {
431 union {
432 struct tpacket_hdr *h1;
433 struct tpacket2_hdr *h2;
434 void *raw;
435 } h;
436
437 smp_rmb();
438
439 h.raw = frame;
440 switch (po->tp_version) {
441 case TPACKET_V1:
442 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
443 return h.h1->tp_status;
444 case TPACKET_V2:
445 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
446 return h.h2->tp_status;
447 case TPACKET_V3:
448 default:
449 WARN(1, "TPACKET version not supported.\n");
450 BUG();
451 return 0;
452 }
453 }
454
455 static void *packet_lookup_frame(struct packet_sock *po,
456 struct packet_ring_buffer *rb,
457 unsigned int position,
458 int status)
459 {
460 unsigned int pg_vec_pos, frame_offset;
461 union {
462 struct tpacket_hdr *h1;
463 struct tpacket2_hdr *h2;
464 void *raw;
465 } h;
466
467 pg_vec_pos = position / rb->frames_per_block;
468 frame_offset = position % rb->frames_per_block;
469
470 h.raw = rb->pg_vec[pg_vec_pos].buffer +
471 (frame_offset * rb->frame_size);
472
473 if (status != __packet_get_status(po, h.raw))
474 return NULL;
475
476 return h.raw;
477 }
478
479 static void *packet_current_frame(struct packet_sock *po,
480 struct packet_ring_buffer *rb,
481 int status)
482 {
483 return packet_lookup_frame(po, rb, rb->head, status);
484 }
485
486 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
487 {
488 del_timer_sync(&pkc->retire_blk_timer);
489 }
490
491 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
492 int tx_ring,
493 struct sk_buff_head *rb_queue)
494 {
495 struct tpacket_kbdq_core *pkc;
496
497 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
498
499 spin_lock(&rb_queue->lock);
500 pkc->delete_blk_timer = 1;
501 spin_unlock(&rb_queue->lock);
502
503 prb_del_retire_blk_timer(pkc);
504 }
505
506 static void prb_init_blk_timer(struct packet_sock *po,
507 struct tpacket_kbdq_core *pkc,
508 void (*func) (unsigned long))
509 {
510 init_timer(&pkc->retire_blk_timer);
511 pkc->retire_blk_timer.data = (long)po;
512 pkc->retire_blk_timer.function = func;
513 pkc->retire_blk_timer.expires = jiffies;
514 }
515
516 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
517 {
518 struct tpacket_kbdq_core *pkc;
519
520 if (tx_ring)
521 BUG();
522
523 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
524 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
525 }
526
527 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
528 int blk_size_in_bytes)
529 {
530 struct net_device *dev;
531 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
532 struct ethtool_cmd ecmd;
533 int err;
534 u32 speed;
535
536 rtnl_lock();
537 dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
538 if (unlikely(!dev)) {
539 rtnl_unlock();
540 return DEFAULT_PRB_RETIRE_TOV;
541 }
542 err = __ethtool_get_settings(dev, &ecmd);
543 speed = ethtool_cmd_speed(&ecmd);
544 rtnl_unlock();
545 if (!err) {
546 /*
547 * If the link speed is so slow you don't really
548 * need to worry about perf anyways
549 */
550 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
551 return DEFAULT_PRB_RETIRE_TOV;
552 } else {
553 msec = 1;
554 div = speed / 1000;
555 }
556 }
557
558 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
559
560 if (div)
561 mbits /= div;
562
563 tmo = mbits * msec;
564
565 if (div)
566 return tmo+1;
567 return tmo;
568 }
569
570 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
571 union tpacket_req_u *req_u)
572 {
573 p1->feature_req_word = req_u->req3.tp_feature_req_word;
574 }
575
576 static void init_prb_bdqc(struct packet_sock *po,
577 struct packet_ring_buffer *rb,
578 struct pgv *pg_vec,
579 union tpacket_req_u *req_u, int tx_ring)
580 {
581 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
582 struct tpacket_block_desc *pbd;
583
584 memset(p1, 0x0, sizeof(*p1));
585
586 p1->knxt_seq_num = 1;
587 p1->pkbdq = pg_vec;
588 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
589 p1->pkblk_start = pg_vec[0].buffer;
590 p1->kblk_size = req_u->req3.tp_block_size;
591 p1->knum_blocks = req_u->req3.tp_block_nr;
592 p1->hdrlen = po->tp_hdrlen;
593 p1->version = po->tp_version;
594 p1->last_kactive_blk_num = 0;
595 po->stats_u.stats3.tp_freeze_q_cnt = 0;
596 if (req_u->req3.tp_retire_blk_tov)
597 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
598 else
599 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
600 req_u->req3.tp_block_size);
601 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
602 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
603
604 prb_init_ft_ops(p1, req_u);
605 prb_setup_retire_blk_timer(po, tx_ring);
606 prb_open_block(p1, pbd);
607 }
608
609 /* Do NOT update the last_blk_num first.
610 * Assumes sk_buff_head lock is held.
611 */
612 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
613 {
614 mod_timer(&pkc->retire_blk_timer,
615 jiffies + pkc->tov_in_jiffies);
616 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
617 }
618
619 /*
620 * Timer logic:
621 * 1) We refresh the timer only when we open a block.
622 * By doing this we don't waste cycles refreshing the timer
623 * on packet-by-packet basis.
624 *
625 * With a 1MB block-size, on a 1Gbps line, it will take
626 * i) ~8 ms to fill a block + ii) memcpy etc.
627 * In this cut we are not accounting for the memcpy time.
628 *
629 * So, if the user sets the 'tmo' to 10ms then the timer
630 * will never fire while the block is still getting filled
631 * (which is what we want). However, the user could choose
632 * to close a block early and that's fine.
633 *
634 * But when the timer does fire, we check whether or not to refresh it.
635 * Since the tmo granularity is in msecs, it is not too expensive
636 * to refresh the timer, lets say every '8' msecs.
637 * Either the user can set the 'tmo' or we can derive it based on
638 * a) line-speed and b) block-size.
639 * prb_calc_retire_blk_tmo() calculates the tmo.
640 *
641 */
642 static void prb_retire_rx_blk_timer_expired(unsigned long data)
643 {
644 struct packet_sock *po = (struct packet_sock *)data;
645 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
646 unsigned int frozen;
647 struct tpacket_block_desc *pbd;
648
649 spin_lock(&po->sk.sk_receive_queue.lock);
650
651 frozen = prb_queue_frozen(pkc);
652 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
653
654 if (unlikely(pkc->delete_blk_timer))
655 goto out;
656
657 /* We only need to plug the race when the block is partially filled.
658 * tpacket_rcv:
659 * lock(); increment BLOCK_NUM_PKTS; unlock()
660 * copy_bits() is in progress ...
661 * timer fires on other cpu:
662 * we can't retire the current block because copy_bits
663 * is in progress.
664 *
665 */
666 if (BLOCK_NUM_PKTS(pbd)) {
667 while (atomic_read(&pkc->blk_fill_in_prog)) {
668 /* Waiting for skb_copy_bits to finish... */
669 cpu_relax();
670 }
671 }
672
673 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
674 if (!frozen) {
675 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
676 if (!prb_dispatch_next_block(pkc, po))
677 goto refresh_timer;
678 else
679 goto out;
680 } else {
681 /* Case 1. Queue was frozen because user-space was
682 * lagging behind.
683 */
684 if (prb_curr_blk_in_use(pkc, pbd)) {
685 /*
686 * Ok, user-space is still behind.
687 * So just refresh the timer.
688 */
689 goto refresh_timer;
690 } else {
691 /* Case 2. queue was frozen,user-space caught up,
692 * now the link went idle && the timer fired.
693 * We don't have a block to close.So we open this
694 * block and restart the timer.
695 * opening a block thaws the queue,restarts timer
696 * Thawing/timer-refresh is a side effect.
697 */
698 prb_open_block(pkc, pbd);
699 goto out;
700 }
701 }
702 }
703
704 refresh_timer:
705 _prb_refresh_rx_retire_blk_timer(pkc);
706
707 out:
708 spin_unlock(&po->sk.sk_receive_queue.lock);
709 }
710
711 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
712 struct tpacket_block_desc *pbd1, __u32 status)
713 {
714 /* Flush everything minus the block header */
715
716 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
717 u8 *start, *end;
718
719 start = (u8 *)pbd1;
720
721 /* Skip the block header(we know header WILL fit in 4K) */
722 start += PAGE_SIZE;
723
724 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
725 for (; start < end; start += PAGE_SIZE)
726 flush_dcache_page(pgv_to_page(start));
727
728 smp_wmb();
729 #endif
730
731 /* Now update the block status. */
732
733 BLOCK_STATUS(pbd1) = status;
734
735 /* Flush the block header */
736
737 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
738 start = (u8 *)pbd1;
739 flush_dcache_page(pgv_to_page(start));
740
741 smp_wmb();
742 #endif
743 }
744
745 /*
746 * Side effect:
747 *
748 * 1) flush the block
749 * 2) Increment active_blk_num
750 *
751 * Note:We DONT refresh the timer on purpose.
752 * Because almost always the next block will be opened.
753 */
754 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
755 struct tpacket_block_desc *pbd1,
756 struct packet_sock *po, unsigned int stat)
757 {
758 __u32 status = TP_STATUS_USER | stat;
759
760 struct tpacket3_hdr *last_pkt;
761 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
762
763 if (po->stats.tp_drops)
764 status |= TP_STATUS_LOSING;
765
766 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
767 last_pkt->tp_next_offset = 0;
768
769 /* Get the ts of the last pkt */
770 if (BLOCK_NUM_PKTS(pbd1)) {
771 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
772 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
773 } else {
774 /* Ok, we tmo'd - so get the current time */
775 struct timespec ts;
776 getnstimeofday(&ts);
777 h1->ts_last_pkt.ts_sec = ts.tv_sec;
778 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
779 }
780
781 smp_wmb();
782
783 /* Flush the block */
784 prb_flush_block(pkc1, pbd1, status);
785
786 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
787 }
788
789 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
790 {
791 pkc->reset_pending_on_curr_blk = 0;
792 }
793
794 /*
795 * Side effect of opening a block:
796 *
797 * 1) prb_queue is thawed.
798 * 2) retire_blk_timer is refreshed.
799 *
800 */
801 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
802 struct tpacket_block_desc *pbd1)
803 {
804 struct timespec ts;
805 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
806
807 smp_rmb();
808
809 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) {
810
811 /* We could have just memset this but we will lose the
812 * flexibility of making the priv area sticky
813 */
814 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
815 BLOCK_NUM_PKTS(pbd1) = 0;
816 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
817 getnstimeofday(&ts);
818 h1->ts_first_pkt.ts_sec = ts.tv_sec;
819 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
820 pkc1->pkblk_start = (char *)pbd1;
821 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
822 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
823 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
824 pbd1->version = pkc1->version;
825 pkc1->prev = pkc1->nxt_offset;
826 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
827 prb_thaw_queue(pkc1);
828 _prb_refresh_rx_retire_blk_timer(pkc1);
829
830 smp_wmb();
831
832 return;
833 }
834
835 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n",
836 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num);
837 dump_stack();
838 BUG();
839 }
840
841 /*
842 * Queue freeze logic:
843 * 1) Assume tp_block_nr = 8 blocks.
844 * 2) At time 't0', user opens Rx ring.
845 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
846 * 4) user-space is either sleeping or processing block '0'.
847 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
848 * it will close block-7,loop around and try to fill block '0'.
849 * call-flow:
850 * __packet_lookup_frame_in_block
851 * prb_retire_current_block()
852 * prb_dispatch_next_block()
853 * |->(BLOCK_STATUS == USER) evaluates to true
854 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
855 * 6) Now there are two cases:
856 * 6.1) Link goes idle right after the queue is frozen.
857 * But remember, the last open_block() refreshed the timer.
858 * When this timer expires,it will refresh itself so that we can
859 * re-open block-0 in near future.
860 * 6.2) Link is busy and keeps on receiving packets. This is a simple
861 * case and __packet_lookup_frame_in_block will check if block-0
862 * is free and can now be re-used.
863 */
864 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
865 struct packet_sock *po)
866 {
867 pkc->reset_pending_on_curr_blk = 1;
868 po->stats_u.stats3.tp_freeze_q_cnt++;
869 }
870
871 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
872
873 /*
874 * If the next block is free then we will dispatch it
875 * and return a good offset.
876 * Else, we will freeze the queue.
877 * So, caller must check the return value.
878 */
879 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
880 struct packet_sock *po)
881 {
882 struct tpacket_block_desc *pbd;
883
884 smp_rmb();
885
886 /* 1. Get current block num */
887 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
888
889 /* 2. If this block is currently in_use then freeze the queue */
890 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
891 prb_freeze_queue(pkc, po);
892 return NULL;
893 }
894
895 /*
896 * 3.
897 * open this block and return the offset where the first packet
898 * needs to get stored.
899 */
900 prb_open_block(pkc, pbd);
901 return (void *)pkc->nxt_offset;
902 }
903
904 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
905 struct packet_sock *po, unsigned int status)
906 {
907 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
908
909 /* retire/close the current block */
910 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
911 /*
912 * Plug the case where copy_bits() is in progress on
913 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
914 * have space to copy the pkt in the current block and
915 * called prb_retire_current_block()
916 *
917 * We don't need to worry about the TMO case because
918 * the timer-handler already handled this case.
919 */
920 if (!(status & TP_STATUS_BLK_TMO)) {
921 while (atomic_read(&pkc->blk_fill_in_prog)) {
922 /* Waiting for skb_copy_bits to finish... */
923 cpu_relax();
924 }
925 }
926 prb_close_block(pkc, pbd, po, status);
927 return;
928 }
929
930 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd);
931 dump_stack();
932 BUG();
933 }
934
935 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
936 struct tpacket_block_desc *pbd)
937 {
938 return TP_STATUS_USER & BLOCK_STATUS(pbd);
939 }
940
941 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
942 {
943 return pkc->reset_pending_on_curr_blk;
944 }
945
946 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
947 {
948 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
949 atomic_dec(&pkc->blk_fill_in_prog);
950 }
951
952 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
953 struct tpacket3_hdr *ppd)
954 {
955 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
956 }
957
958 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
959 struct tpacket3_hdr *ppd)
960 {
961 ppd->hv1.tp_rxhash = 0;
962 }
963
964 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
965 struct tpacket3_hdr *ppd)
966 {
967 if (vlan_tx_tag_present(pkc->skb)) {
968 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
969 ppd->tp_status = TP_STATUS_VLAN_VALID;
970 } else {
971 ppd->hv1.tp_vlan_tci = ppd->tp_status = 0;
972 }
973 }
974
975 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
976 struct tpacket3_hdr *ppd)
977 {
978 prb_fill_vlan_info(pkc, ppd);
979
980 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
981 prb_fill_rxhash(pkc, ppd);
982 else
983 prb_clear_rxhash(pkc, ppd);
984 }
985
986 static void prb_fill_curr_block(char *curr,
987 struct tpacket_kbdq_core *pkc,
988 struct tpacket_block_desc *pbd,
989 unsigned int len)
990 {
991 struct tpacket3_hdr *ppd;
992
993 ppd = (struct tpacket3_hdr *)curr;
994 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
995 pkc->prev = curr;
996 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
997 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
998 BLOCK_NUM_PKTS(pbd) += 1;
999 atomic_inc(&pkc->blk_fill_in_prog);
1000 prb_run_all_ft_ops(pkc, ppd);
1001 }
1002
1003 /* Assumes caller has the sk->rx_queue.lock */
1004 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1005 struct sk_buff *skb,
1006 int status,
1007 unsigned int len
1008 )
1009 {
1010 struct tpacket_kbdq_core *pkc;
1011 struct tpacket_block_desc *pbd;
1012 char *curr, *end;
1013
1014 pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1015 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1016
1017 /* Queue is frozen when user space is lagging behind */
1018 if (prb_queue_frozen(pkc)) {
1019 /*
1020 * Check if that last block which caused the queue to freeze,
1021 * is still in_use by user-space.
1022 */
1023 if (prb_curr_blk_in_use(pkc, pbd)) {
1024 /* Can't record this packet */
1025 return NULL;
1026 } else {
1027 /*
1028 * Ok, the block was released by user-space.
1029 * Now let's open that block.
1030 * opening a block also thaws the queue.
1031 * Thawing is a side effect.
1032 */
1033 prb_open_block(pkc, pbd);
1034 }
1035 }
1036
1037 smp_mb();
1038 curr = pkc->nxt_offset;
1039 pkc->skb = skb;
1040 end = (char *)pbd + pkc->kblk_size;
1041
1042 /* first try the current block */
1043 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1044 prb_fill_curr_block(curr, pkc, pbd, len);
1045 return (void *)curr;
1046 }
1047
1048 /* Ok, close the current block */
1049 prb_retire_current_block(pkc, po, 0);
1050
1051 /* Now, try to dispatch the next block */
1052 curr = (char *)prb_dispatch_next_block(pkc, po);
1053 if (curr) {
1054 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1055 prb_fill_curr_block(curr, pkc, pbd, len);
1056 return (void *)curr;
1057 }
1058
1059 /*
1060 * No free blocks are available.user_space hasn't caught up yet.
1061 * Queue was just frozen and now this packet will get dropped.
1062 */
1063 return NULL;
1064 }
1065
1066 static void *packet_current_rx_frame(struct packet_sock *po,
1067 struct sk_buff *skb,
1068 int status, unsigned int len)
1069 {
1070 char *curr = NULL;
1071 switch (po->tp_version) {
1072 case TPACKET_V1:
1073 case TPACKET_V2:
1074 curr = packet_lookup_frame(po, &po->rx_ring,
1075 po->rx_ring.head, status);
1076 return curr;
1077 case TPACKET_V3:
1078 return __packet_lookup_frame_in_block(po, skb, status, len);
1079 default:
1080 WARN(1, "TPACKET version not supported\n");
1081 BUG();
1082 return NULL;
1083 }
1084 }
1085
1086 static void *prb_lookup_block(struct packet_sock *po,
1087 struct packet_ring_buffer *rb,
1088 unsigned int previous,
1089 int status)
1090 {
1091 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1092 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
1093
1094 if (status != BLOCK_STATUS(pbd))
1095 return NULL;
1096 return pbd;
1097 }
1098
1099 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1100 {
1101 unsigned int prev;
1102 if (rb->prb_bdqc.kactive_blk_num)
1103 prev = rb->prb_bdqc.kactive_blk_num-1;
1104 else
1105 prev = rb->prb_bdqc.knum_blocks-1;
1106 return prev;
1107 }
1108
1109 /* Assumes caller has held the rx_queue.lock */
1110 static void *__prb_previous_block(struct packet_sock *po,
1111 struct packet_ring_buffer *rb,
1112 int status)
1113 {
1114 unsigned int previous = prb_previous_blk_num(rb);
1115 return prb_lookup_block(po, rb, previous, status);
1116 }
1117
1118 static void *packet_previous_rx_frame(struct packet_sock *po,
1119 struct packet_ring_buffer *rb,
1120 int status)
1121 {
1122 if (po->tp_version <= TPACKET_V2)
1123 return packet_previous_frame(po, rb, status);
1124
1125 return __prb_previous_block(po, rb, status);
1126 }
1127
1128 static void packet_increment_rx_head(struct packet_sock *po,
1129 struct packet_ring_buffer *rb)
1130 {
1131 switch (po->tp_version) {
1132 case TPACKET_V1:
1133 case TPACKET_V2:
1134 return packet_increment_head(rb);
1135 case TPACKET_V3:
1136 default:
1137 WARN(1, "TPACKET version not supported.\n");
1138 BUG();
1139 return;
1140 }
1141 }
1142
1143 static void *packet_previous_frame(struct packet_sock *po,
1144 struct packet_ring_buffer *rb,
1145 int status)
1146 {
1147 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1148 return packet_lookup_frame(po, rb, previous, status);
1149 }
1150
1151 static void packet_increment_head(struct packet_ring_buffer *buff)
1152 {
1153 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1154 }
1155
1156 static void packet_sock_destruct(struct sock *sk)
1157 {
1158 skb_queue_purge(&sk->sk_error_queue);
1159
1160 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1161 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1162
1163 if (!sock_flag(sk, SOCK_DEAD)) {
1164 pr_err("Attempt to release alive packet socket: %p\n", sk);
1165 return;
1166 }
1167
1168 sk_refcnt_debug_dec(sk);
1169 }
1170
1171 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1172 {
1173 int x = atomic_read(&f->rr_cur) + 1;
1174
1175 if (x >= num)
1176 x = 0;
1177
1178 return x;
1179 }
1180
1181 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1182 {
1183 u32 idx, hash = skb->rxhash;
1184
1185 idx = ((u64)hash * num) >> 32;
1186
1187 return f->arr[idx];
1188 }
1189
1190 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1191 {
1192 int cur, old;
1193
1194 cur = atomic_read(&f->rr_cur);
1195 while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1196 fanout_rr_next(f, num))) != cur)
1197 cur = old;
1198 return f->arr[cur];
1199 }
1200
1201 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1202 {
1203 unsigned int cpu = smp_processor_id();
1204
1205 return f->arr[cpu % num];
1206 }
1207
1208 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1209 struct packet_type *pt, struct net_device *orig_dev)
1210 {
1211 struct packet_fanout *f = pt->af_packet_priv;
1212 unsigned int num = f->num_members;
1213 struct packet_sock *po;
1214 struct sock *sk;
1215
1216 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1217 !num) {
1218 kfree_skb(skb);
1219 return 0;
1220 }
1221
1222 switch (f->type) {
1223 case PACKET_FANOUT_HASH:
1224 default:
1225 if (f->defrag) {
1226 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1227 if (!skb)
1228 return 0;
1229 }
1230 skb_get_rxhash(skb);
1231 sk = fanout_demux_hash(f, skb, num);
1232 break;
1233 case PACKET_FANOUT_LB:
1234 sk = fanout_demux_lb(f, skb, num);
1235 break;
1236 case PACKET_FANOUT_CPU:
1237 sk = fanout_demux_cpu(f, skb, num);
1238 break;
1239 }
1240
1241 po = pkt_sk(sk);
1242
1243 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1244 }
1245
1246 static DEFINE_MUTEX(fanout_mutex);
1247 static LIST_HEAD(fanout_list);
1248
1249 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1250 {
1251 struct packet_fanout *f = po->fanout;
1252
1253 spin_lock(&f->lock);
1254 f->arr[f->num_members] = sk;
1255 smp_wmb();
1256 f->num_members++;
1257 spin_unlock(&f->lock);
1258 }
1259
1260 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1261 {
1262 struct packet_fanout *f = po->fanout;
1263 int i;
1264
1265 spin_lock(&f->lock);
1266 for (i = 0; i < f->num_members; i++) {
1267 if (f->arr[i] == sk)
1268 break;
1269 }
1270 BUG_ON(i >= f->num_members);
1271 f->arr[i] = f->arr[f->num_members - 1];
1272 f->num_members--;
1273 spin_unlock(&f->lock);
1274 }
1275
1276 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1277 {
1278 struct packet_sock *po = pkt_sk(sk);
1279 struct packet_fanout *f, *match;
1280 u8 type = type_flags & 0xff;
1281 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
1282 int err;
1283
1284 switch (type) {
1285 case PACKET_FANOUT_HASH:
1286 case PACKET_FANOUT_LB:
1287 case PACKET_FANOUT_CPU:
1288 break;
1289 default:
1290 return -EINVAL;
1291 }
1292
1293 if (!po->running)
1294 return -EINVAL;
1295
1296 if (po->fanout)
1297 return -EALREADY;
1298
1299 mutex_lock(&fanout_mutex);
1300 match = NULL;
1301 list_for_each_entry(f, &fanout_list, list) {
1302 if (f->id == id &&
1303 read_pnet(&f->net) == sock_net(sk)) {
1304 match = f;
1305 break;
1306 }
1307 }
1308 err = -EINVAL;
1309 if (match && match->defrag != defrag)
1310 goto out;
1311 if (!match) {
1312 err = -ENOMEM;
1313 match = kzalloc(sizeof(*match), GFP_KERNEL);
1314 if (!match)
1315 goto out;
1316 write_pnet(&match->net, sock_net(sk));
1317 match->id = id;
1318 match->type = type;
1319 match->defrag = defrag;
1320 atomic_set(&match->rr_cur, 0);
1321 INIT_LIST_HEAD(&match->list);
1322 spin_lock_init(&match->lock);
1323 atomic_set(&match->sk_ref, 0);
1324 match->prot_hook.type = po->prot_hook.type;
1325 match->prot_hook.dev = po->prot_hook.dev;
1326 match->prot_hook.func = packet_rcv_fanout;
1327 match->prot_hook.af_packet_priv = match;
1328 dev_add_pack(&match->prot_hook);
1329 list_add(&match->list, &fanout_list);
1330 }
1331 err = -EINVAL;
1332 if (match->type == type &&
1333 match->prot_hook.type == po->prot_hook.type &&
1334 match->prot_hook.dev == po->prot_hook.dev) {
1335 err = -ENOSPC;
1336 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1337 __dev_remove_pack(&po->prot_hook);
1338 po->fanout = match;
1339 atomic_inc(&match->sk_ref);
1340 __fanout_link(sk, po);
1341 err = 0;
1342 }
1343 }
1344 out:
1345 mutex_unlock(&fanout_mutex);
1346 return err;
1347 }
1348
1349 static void fanout_release(struct sock *sk)
1350 {
1351 struct packet_sock *po = pkt_sk(sk);
1352 struct packet_fanout *f;
1353
1354 f = po->fanout;
1355 if (!f)
1356 return;
1357
1358 po->fanout = NULL;
1359
1360 mutex_lock(&fanout_mutex);
1361 if (atomic_dec_and_test(&f->sk_ref)) {
1362 list_del(&f->list);
1363 dev_remove_pack(&f->prot_hook);
1364 kfree(f);
1365 }
1366 mutex_unlock(&fanout_mutex);
1367 }
1368
1369 static const struct proto_ops packet_ops;
1370
1371 static const struct proto_ops packet_ops_spkt;
1372
1373 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1374 struct packet_type *pt, struct net_device *orig_dev)
1375 {
1376 struct sock *sk;
1377 struct sockaddr_pkt *spkt;
1378
1379 /*
1380 * When we registered the protocol we saved the socket in the data
1381 * field for just this event.
1382 */
1383
1384 sk = pt->af_packet_priv;
1385
1386 /*
1387 * Yank back the headers [hope the device set this
1388 * right or kerboom...]
1389 *
1390 * Incoming packets have ll header pulled,
1391 * push it back.
1392 *
1393 * For outgoing ones skb->data == skb_mac_header(skb)
1394 * so that this procedure is noop.
1395 */
1396
1397 if (skb->pkt_type == PACKET_LOOPBACK)
1398 goto out;
1399
1400 if (!net_eq(dev_net(dev), sock_net(sk)))
1401 goto out;
1402
1403 skb = skb_share_check(skb, GFP_ATOMIC);
1404 if (skb == NULL)
1405 goto oom;
1406
1407 /* drop any routing info */
1408 skb_dst_drop(skb);
1409
1410 /* drop conntrack reference */
1411 nf_reset(skb);
1412
1413 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1414
1415 skb_push(skb, skb->data - skb_mac_header(skb));
1416
1417 /*
1418 * The SOCK_PACKET socket receives _all_ frames.
1419 */
1420
1421 spkt->spkt_family = dev->type;
1422 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1423 spkt->spkt_protocol = skb->protocol;
1424
1425 /*
1426 * Charge the memory to the socket. This is done specifically
1427 * to prevent sockets using all the memory up.
1428 */
1429
1430 if (sock_queue_rcv_skb(sk, skb) == 0)
1431 return 0;
1432
1433 out:
1434 kfree_skb(skb);
1435 oom:
1436 return 0;
1437 }
1438
1439
1440 /*
1441 * Output a raw packet to a device layer. This bypasses all the other
1442 * protocol layers and you must therefore supply it with a complete frame
1443 */
1444
1445 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1446 struct msghdr *msg, size_t len)
1447 {
1448 struct sock *sk = sock->sk;
1449 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1450 struct sk_buff *skb = NULL;
1451 struct net_device *dev;
1452 __be16 proto = 0;
1453 int err;
1454 int extra_len = 0;
1455
1456 /*
1457 * Get and verify the address.
1458 */
1459
1460 if (saddr) {
1461 if (msg->msg_namelen < sizeof(struct sockaddr))
1462 return -EINVAL;
1463 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1464 proto = saddr->spkt_protocol;
1465 } else
1466 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1467
1468 /*
1469 * Find the device first to size check it
1470 */
1471
1472 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1473 retry:
1474 rcu_read_lock();
1475 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1476 err = -ENODEV;
1477 if (dev == NULL)
1478 goto out_unlock;
1479
1480 err = -ENETDOWN;
1481 if (!(dev->flags & IFF_UP))
1482 goto out_unlock;
1483
1484 /*
1485 * You may not queue a frame bigger than the mtu. This is the lowest level
1486 * raw protocol and you must do your own fragmentation at this level.
1487 */
1488
1489 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1490 if (!netif_supports_nofcs(dev)) {
1491 err = -EPROTONOSUPPORT;
1492 goto out_unlock;
1493 }
1494 extra_len = 4; /* We're doing our own CRC */
1495 }
1496
1497 err = -EMSGSIZE;
1498 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1499 goto out_unlock;
1500
1501 if (!skb) {
1502 size_t reserved = LL_RESERVED_SPACE(dev);
1503 int tlen = dev->needed_tailroom;
1504 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1505
1506 rcu_read_unlock();
1507 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1508 if (skb == NULL)
1509 return -ENOBUFS;
1510 /* FIXME: Save some space for broken drivers that write a hard
1511 * header at transmission time by themselves. PPP is the notable
1512 * one here. This should really be fixed at the driver level.
1513 */
1514 skb_reserve(skb, reserved);
1515 skb_reset_network_header(skb);
1516
1517 /* Try to align data part correctly */
1518 if (hhlen) {
1519 skb->data -= hhlen;
1520 skb->tail -= hhlen;
1521 if (len < hhlen)
1522 skb_reset_network_header(skb);
1523 }
1524 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1525 if (err)
1526 goto out_free;
1527 goto retry;
1528 }
1529
1530 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1531 /* Earlier code assumed this would be a VLAN pkt,
1532 * double-check this now that we have the actual
1533 * packet in hand.
1534 */
1535 struct ethhdr *ehdr;
1536 skb_reset_mac_header(skb);
1537 ehdr = eth_hdr(skb);
1538 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1539 err = -EMSGSIZE;
1540 goto out_unlock;
1541 }
1542 }
1543
1544 skb->protocol = proto;
1545 skb->dev = dev;
1546 skb->priority = sk->sk_priority;
1547 skb->mark = sk->sk_mark;
1548 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1549 if (err < 0)
1550 goto out_unlock;
1551
1552 if (unlikely(extra_len == 4))
1553 skb->no_fcs = 1;
1554
1555 dev_queue_xmit(skb);
1556 rcu_read_unlock();
1557 return len;
1558
1559 out_unlock:
1560 rcu_read_unlock();
1561 out_free:
1562 kfree_skb(skb);
1563 return err;
1564 }
1565
1566 static unsigned int run_filter(const struct sk_buff *skb,
1567 const struct sock *sk,
1568 unsigned int res)
1569 {
1570 struct sk_filter *filter;
1571
1572 rcu_read_lock();
1573 filter = rcu_dereference(sk->sk_filter);
1574 if (filter != NULL)
1575 res = SK_RUN_FILTER(filter, skb);
1576 rcu_read_unlock();
1577
1578 return res;
1579 }
1580
1581 /*
1582 * This function makes lazy skb cloning in hope that most of packets
1583 * are discarded by BPF.
1584 *
1585 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1586 * and skb->cb are mangled. It works because (and until) packets
1587 * falling here are owned by current CPU. Output packets are cloned
1588 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1589 * sequencially, so that if we return skb to original state on exit,
1590 * we will not harm anyone.
1591 */
1592
1593 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1594 struct packet_type *pt, struct net_device *orig_dev)
1595 {
1596 struct sock *sk;
1597 struct sockaddr_ll *sll;
1598 struct packet_sock *po;
1599 u8 *skb_head = skb->data;
1600 int skb_len = skb->len;
1601 unsigned int snaplen, res;
1602
1603 if (skb->pkt_type == PACKET_LOOPBACK)
1604 goto drop;
1605
1606 sk = pt->af_packet_priv;
1607 po = pkt_sk(sk);
1608
1609 if (!net_eq(dev_net(dev), sock_net(sk)))
1610 goto drop;
1611
1612 skb->dev = dev;
1613
1614 if (dev->header_ops) {
1615 /* The device has an explicit notion of ll header,
1616 * exported to higher levels.
1617 *
1618 * Otherwise, the device hides details of its frame
1619 * structure, so that corresponding packet head is
1620 * never delivered to user.
1621 */
1622 if (sk->sk_type != SOCK_DGRAM)
1623 skb_push(skb, skb->data - skb_mac_header(skb));
1624 else if (skb->pkt_type == PACKET_OUTGOING) {
1625 /* Special case: outgoing packets have ll header at head */
1626 skb_pull(skb, skb_network_offset(skb));
1627 }
1628 }
1629
1630 snaplen = skb->len;
1631
1632 res = run_filter(skb, sk, snaplen);
1633 if (!res)
1634 goto drop_n_restore;
1635 if (snaplen > res)
1636 snaplen = res;
1637
1638 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1639 goto drop_n_acct;
1640
1641 if (skb_shared(skb)) {
1642 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1643 if (nskb == NULL)
1644 goto drop_n_acct;
1645
1646 if (skb_head != skb->data) {
1647 skb->data = skb_head;
1648 skb->len = skb_len;
1649 }
1650 consume_skb(skb);
1651 skb = nskb;
1652 }
1653
1654 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1655 sizeof(skb->cb));
1656
1657 sll = &PACKET_SKB_CB(skb)->sa.ll;
1658 sll->sll_family = AF_PACKET;
1659 sll->sll_hatype = dev->type;
1660 sll->sll_protocol = skb->protocol;
1661 sll->sll_pkttype = skb->pkt_type;
1662 if (unlikely(po->origdev))
1663 sll->sll_ifindex = orig_dev->ifindex;
1664 else
1665 sll->sll_ifindex = dev->ifindex;
1666
1667 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1668
1669 PACKET_SKB_CB(skb)->origlen = skb->len;
1670
1671 if (pskb_trim(skb, snaplen))
1672 goto drop_n_acct;
1673
1674 skb_set_owner_r(skb, sk);
1675 skb->dev = NULL;
1676 skb_dst_drop(skb);
1677
1678 /* drop conntrack reference */
1679 nf_reset(skb);
1680
1681 spin_lock(&sk->sk_receive_queue.lock);
1682 po->stats.tp_packets++;
1683 skb->dropcount = atomic_read(&sk->sk_drops);
1684 __skb_queue_tail(&sk->sk_receive_queue, skb);
1685 spin_unlock(&sk->sk_receive_queue.lock);
1686 sk->sk_data_ready(sk, skb->len);
1687 return 0;
1688
1689 drop_n_acct:
1690 spin_lock(&sk->sk_receive_queue.lock);
1691 po->stats.tp_drops++;
1692 atomic_inc(&sk->sk_drops);
1693 spin_unlock(&sk->sk_receive_queue.lock);
1694
1695 drop_n_restore:
1696 if (skb_head != skb->data && skb_shared(skb)) {
1697 skb->data = skb_head;
1698 skb->len = skb_len;
1699 }
1700 drop:
1701 consume_skb(skb);
1702 return 0;
1703 }
1704
1705 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1706 struct packet_type *pt, struct net_device *orig_dev)
1707 {
1708 struct sock *sk;
1709 struct packet_sock *po;
1710 struct sockaddr_ll *sll;
1711 union {
1712 struct tpacket_hdr *h1;
1713 struct tpacket2_hdr *h2;
1714 struct tpacket3_hdr *h3;
1715 void *raw;
1716 } h;
1717 u8 *skb_head = skb->data;
1718 int skb_len = skb->len;
1719 unsigned int snaplen, res;
1720 unsigned long status = TP_STATUS_USER;
1721 unsigned short macoff, netoff, hdrlen;
1722 struct sk_buff *copy_skb = NULL;
1723 struct timeval tv;
1724 struct timespec ts;
1725 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
1726
1727 if (skb->pkt_type == PACKET_LOOPBACK)
1728 goto drop;
1729
1730 sk = pt->af_packet_priv;
1731 po = pkt_sk(sk);
1732
1733 if (!net_eq(dev_net(dev), sock_net(sk)))
1734 goto drop;
1735
1736 if (dev->header_ops) {
1737 if (sk->sk_type != SOCK_DGRAM)
1738 skb_push(skb, skb->data - skb_mac_header(skb));
1739 else if (skb->pkt_type == PACKET_OUTGOING) {
1740 /* Special case: outgoing packets have ll header at head */
1741 skb_pull(skb, skb_network_offset(skb));
1742 }
1743 }
1744
1745 if (skb->ip_summed == CHECKSUM_PARTIAL)
1746 status |= TP_STATUS_CSUMNOTREADY;
1747
1748 snaplen = skb->len;
1749
1750 res = run_filter(skb, sk, snaplen);
1751 if (!res)
1752 goto drop_n_restore;
1753 if (snaplen > res)
1754 snaplen = res;
1755
1756 if (sk->sk_type == SOCK_DGRAM) {
1757 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1758 po->tp_reserve;
1759 } else {
1760 unsigned int maclen = skb_network_offset(skb);
1761 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1762 (maclen < 16 ? 16 : maclen)) +
1763 po->tp_reserve;
1764 macoff = netoff - maclen;
1765 }
1766 if (po->tp_version <= TPACKET_V2) {
1767 if (macoff + snaplen > po->rx_ring.frame_size) {
1768 if (po->copy_thresh &&
1769 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1770 if (skb_shared(skb)) {
1771 copy_skb = skb_clone(skb, GFP_ATOMIC);
1772 } else {
1773 copy_skb = skb_get(skb);
1774 skb_head = skb->data;
1775 }
1776 if (copy_skb)
1777 skb_set_owner_r(copy_skb, sk);
1778 }
1779 snaplen = po->rx_ring.frame_size - macoff;
1780 if ((int)snaplen < 0)
1781 snaplen = 0;
1782 }
1783 }
1784 spin_lock(&sk->sk_receive_queue.lock);
1785 h.raw = packet_current_rx_frame(po, skb,
1786 TP_STATUS_KERNEL, (macoff+snaplen));
1787 if (!h.raw)
1788 goto ring_is_full;
1789 if (po->tp_version <= TPACKET_V2) {
1790 packet_increment_rx_head(po, &po->rx_ring);
1791 /*
1792 * LOSING will be reported till you read the stats,
1793 * because it's COR - Clear On Read.
1794 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1795 * at packet level.
1796 */
1797 if (po->stats.tp_drops)
1798 status |= TP_STATUS_LOSING;
1799 }
1800 po->stats.tp_packets++;
1801 if (copy_skb) {
1802 status |= TP_STATUS_COPY;
1803 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1804 }
1805 spin_unlock(&sk->sk_receive_queue.lock);
1806
1807 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1808
1809 switch (po->tp_version) {
1810 case TPACKET_V1:
1811 h.h1->tp_len = skb->len;
1812 h.h1->tp_snaplen = snaplen;
1813 h.h1->tp_mac = macoff;
1814 h.h1->tp_net = netoff;
1815 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1816 && shhwtstamps->syststamp.tv64)
1817 tv = ktime_to_timeval(shhwtstamps->syststamp);
1818 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1819 && shhwtstamps->hwtstamp.tv64)
1820 tv = ktime_to_timeval(shhwtstamps->hwtstamp);
1821 else if (skb->tstamp.tv64)
1822 tv = ktime_to_timeval(skb->tstamp);
1823 else
1824 do_gettimeofday(&tv);
1825 h.h1->tp_sec = tv.tv_sec;
1826 h.h1->tp_usec = tv.tv_usec;
1827 hdrlen = sizeof(*h.h1);
1828 break;
1829 case TPACKET_V2:
1830 h.h2->tp_len = skb->len;
1831 h.h2->tp_snaplen = snaplen;
1832 h.h2->tp_mac = macoff;
1833 h.h2->tp_net = netoff;
1834 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1835 && shhwtstamps->syststamp.tv64)
1836 ts = ktime_to_timespec(shhwtstamps->syststamp);
1837 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1838 && shhwtstamps->hwtstamp.tv64)
1839 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1840 else if (skb->tstamp.tv64)
1841 ts = ktime_to_timespec(skb->tstamp);
1842 else
1843 getnstimeofday(&ts);
1844 h.h2->tp_sec = ts.tv_sec;
1845 h.h2->tp_nsec = ts.tv_nsec;
1846 if (vlan_tx_tag_present(skb)) {
1847 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1848 status |= TP_STATUS_VLAN_VALID;
1849 } else {
1850 h.h2->tp_vlan_tci = 0;
1851 }
1852 h.h2->tp_padding = 0;
1853 hdrlen = sizeof(*h.h2);
1854 break;
1855 case TPACKET_V3:
1856 /* tp_nxt_offset,vlan are already populated above.
1857 * So DONT clear those fields here
1858 */
1859 h.h3->tp_status |= status;
1860 h.h3->tp_len = skb->len;
1861 h.h3->tp_snaplen = snaplen;
1862 h.h3->tp_mac = macoff;
1863 h.h3->tp_net = netoff;
1864 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1865 && shhwtstamps->syststamp.tv64)
1866 ts = ktime_to_timespec(shhwtstamps->syststamp);
1867 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1868 && shhwtstamps->hwtstamp.tv64)
1869 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1870 else if (skb->tstamp.tv64)
1871 ts = ktime_to_timespec(skb->tstamp);
1872 else
1873 getnstimeofday(&ts);
1874 h.h3->tp_sec = ts.tv_sec;
1875 h.h3->tp_nsec = ts.tv_nsec;
1876 hdrlen = sizeof(*h.h3);
1877 break;
1878 default:
1879 BUG();
1880 }
1881
1882 sll = h.raw + TPACKET_ALIGN(hdrlen);
1883 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1884 sll->sll_family = AF_PACKET;
1885 sll->sll_hatype = dev->type;
1886 sll->sll_protocol = skb->protocol;
1887 sll->sll_pkttype = skb->pkt_type;
1888 if (unlikely(po->origdev))
1889 sll->sll_ifindex = orig_dev->ifindex;
1890 else
1891 sll->sll_ifindex = dev->ifindex;
1892
1893 smp_mb();
1894 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1895 {
1896 u8 *start, *end;
1897
1898 if (po->tp_version <= TPACKET_V2) {
1899 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1900 + macoff + snaplen);
1901 for (start = h.raw; start < end; start += PAGE_SIZE)
1902 flush_dcache_page(pgv_to_page(start));
1903 }
1904 smp_wmb();
1905 }
1906 #endif
1907 if (po->tp_version <= TPACKET_V2)
1908 __packet_set_status(po, h.raw, status);
1909 else
1910 prb_clear_blk_fill_status(&po->rx_ring);
1911
1912 sk->sk_data_ready(sk, 0);
1913
1914 drop_n_restore:
1915 if (skb_head != skb->data && skb_shared(skb)) {
1916 skb->data = skb_head;
1917 skb->len = skb_len;
1918 }
1919 drop:
1920 kfree_skb(skb);
1921 return 0;
1922
1923 ring_is_full:
1924 po->stats.tp_drops++;
1925 spin_unlock(&sk->sk_receive_queue.lock);
1926
1927 sk->sk_data_ready(sk, 0);
1928 kfree_skb(copy_skb);
1929 goto drop_n_restore;
1930 }
1931
1932 static void tpacket_destruct_skb(struct sk_buff *skb)
1933 {
1934 struct packet_sock *po = pkt_sk(skb->sk);
1935 void *ph;
1936
1937 if (likely(po->tx_ring.pg_vec)) {
1938 ph = skb_shinfo(skb)->destructor_arg;
1939 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1940 atomic_dec(&po->tx_ring.pending);
1941 __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
1942 }
1943
1944 sock_wfree(skb);
1945 }
1946
1947 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1948 void *frame, struct net_device *dev, int size_max,
1949 __be16 proto, unsigned char *addr, int hlen)
1950 {
1951 union {
1952 struct tpacket_hdr *h1;
1953 struct tpacket2_hdr *h2;
1954 void *raw;
1955 } ph;
1956 int to_write, offset, len, tp_len, nr_frags, len_max;
1957 struct socket *sock = po->sk.sk_socket;
1958 struct page *page;
1959 void *data;
1960 int err;
1961
1962 ph.raw = frame;
1963
1964 skb->protocol = proto;
1965 skb->dev = dev;
1966 skb->priority = po->sk.sk_priority;
1967 skb->mark = po->sk.sk_mark;
1968 skb_shinfo(skb)->destructor_arg = ph.raw;
1969
1970 switch (po->tp_version) {
1971 case TPACKET_V2:
1972 tp_len = ph.h2->tp_len;
1973 break;
1974 default:
1975 tp_len = ph.h1->tp_len;
1976 break;
1977 }
1978 if (unlikely(tp_len > size_max)) {
1979 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1980 return -EMSGSIZE;
1981 }
1982
1983 skb_reserve(skb, hlen);
1984 skb_reset_network_header(skb);
1985
1986 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1987 to_write = tp_len;
1988
1989 if (sock->type == SOCK_DGRAM) {
1990 err = dev_hard_header(skb, dev, ntohs(proto), addr,
1991 NULL, tp_len);
1992 if (unlikely(err < 0))
1993 return -EINVAL;
1994 } else if (dev->hard_header_len) {
1995 /* net device doesn't like empty head */
1996 if (unlikely(tp_len <= dev->hard_header_len)) {
1997 pr_err("packet size is too short (%d < %d)\n",
1998 tp_len, dev->hard_header_len);
1999 return -EINVAL;
2000 }
2001
2002 skb_push(skb, dev->hard_header_len);
2003 err = skb_store_bits(skb, 0, data,
2004 dev->hard_header_len);
2005 if (unlikely(err))
2006 return err;
2007
2008 data += dev->hard_header_len;
2009 to_write -= dev->hard_header_len;
2010 }
2011
2012 err = -EFAULT;
2013 offset = offset_in_page(data);
2014 len_max = PAGE_SIZE - offset;
2015 len = ((to_write > len_max) ? len_max : to_write);
2016
2017 skb->data_len = to_write;
2018 skb->len += to_write;
2019 skb->truesize += to_write;
2020 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2021
2022 while (likely(to_write)) {
2023 nr_frags = skb_shinfo(skb)->nr_frags;
2024
2025 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2026 pr_err("Packet exceed the number of skb frags(%lu)\n",
2027 MAX_SKB_FRAGS);
2028 return -EFAULT;
2029 }
2030
2031 page = pgv_to_page(data);
2032 data += len;
2033 flush_dcache_page(page);
2034 get_page(page);
2035 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2036 to_write -= len;
2037 offset = 0;
2038 len_max = PAGE_SIZE;
2039 len = ((to_write > len_max) ? len_max : to_write);
2040 }
2041
2042 return tp_len;
2043 }
2044
2045 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2046 {
2047 struct sk_buff *skb;
2048 struct net_device *dev;
2049 __be16 proto;
2050 bool need_rls_dev = false;
2051 int err, reserve = 0;
2052 void *ph;
2053 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2054 int tp_len, size_max;
2055 unsigned char *addr;
2056 int len_sum = 0;
2057 int status = 0;
2058 int hlen, tlen;
2059
2060 mutex_lock(&po->pg_vec_lock);
2061
2062 err = -EBUSY;
2063 if (saddr == NULL) {
2064 dev = po->prot_hook.dev;
2065 proto = po->num;
2066 addr = NULL;
2067 } else {
2068 err = -EINVAL;
2069 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2070 goto out;
2071 if (msg->msg_namelen < (saddr->sll_halen
2072 + offsetof(struct sockaddr_ll,
2073 sll_addr)))
2074 goto out;
2075 proto = saddr->sll_protocol;
2076 addr = saddr->sll_addr;
2077 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2078 need_rls_dev = true;
2079 }
2080
2081 err = -ENXIO;
2082 if (unlikely(dev == NULL))
2083 goto out;
2084
2085 reserve = dev->hard_header_len;
2086
2087 err = -ENETDOWN;
2088 if (unlikely(!(dev->flags & IFF_UP)))
2089 goto out_put;
2090
2091 size_max = po->tx_ring.frame_size
2092 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2093
2094 if (size_max > dev->mtu + reserve)
2095 size_max = dev->mtu + reserve;
2096
2097 do {
2098 ph = packet_current_frame(po, &po->tx_ring,
2099 TP_STATUS_SEND_REQUEST);
2100
2101 if (unlikely(ph == NULL)) {
2102 schedule();
2103 continue;
2104 }
2105
2106 status = TP_STATUS_SEND_REQUEST;
2107 hlen = LL_RESERVED_SPACE(dev);
2108 tlen = dev->needed_tailroom;
2109 skb = sock_alloc_send_skb(&po->sk,
2110 hlen + tlen + sizeof(struct sockaddr_ll),
2111 0, &err);
2112
2113 if (unlikely(skb == NULL))
2114 goto out_status;
2115
2116 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2117 addr, hlen);
2118
2119 if (unlikely(tp_len < 0)) {
2120 if (po->tp_loss) {
2121 __packet_set_status(po, ph,
2122 TP_STATUS_AVAILABLE);
2123 packet_increment_head(&po->tx_ring);
2124 kfree_skb(skb);
2125 continue;
2126 } else {
2127 status = TP_STATUS_WRONG_FORMAT;
2128 err = tp_len;
2129 goto out_status;
2130 }
2131 }
2132
2133 skb->destructor = tpacket_destruct_skb;
2134 __packet_set_status(po, ph, TP_STATUS_SENDING);
2135 atomic_inc(&po->tx_ring.pending);
2136
2137 status = TP_STATUS_SEND_REQUEST;
2138 err = dev_queue_xmit(skb);
2139 if (unlikely(err > 0)) {
2140 err = net_xmit_errno(err);
2141 if (err && __packet_get_status(po, ph) ==
2142 TP_STATUS_AVAILABLE) {
2143 /* skb was destructed already */
2144 skb = NULL;
2145 goto out_status;
2146 }
2147 /*
2148 * skb was dropped but not destructed yet;
2149 * let's treat it like congestion or err < 0
2150 */
2151 err = 0;
2152 }
2153 packet_increment_head(&po->tx_ring);
2154 len_sum += tp_len;
2155 } while (likely((ph != NULL) ||
2156 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2157 (atomic_read(&po->tx_ring.pending))))
2158 );
2159
2160 err = len_sum;
2161 goto out_put;
2162
2163 out_status:
2164 __packet_set_status(po, ph, status);
2165 kfree_skb(skb);
2166 out_put:
2167 if (need_rls_dev)
2168 dev_put(dev);
2169 out:
2170 mutex_unlock(&po->pg_vec_lock);
2171 return err;
2172 }
2173
2174 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2175 size_t reserve, size_t len,
2176 size_t linear, int noblock,
2177 int *err)
2178 {
2179 struct sk_buff *skb;
2180
2181 /* Under a page? Don't bother with paged skb. */
2182 if (prepad + len < PAGE_SIZE || !linear)
2183 linear = len;
2184
2185 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2186 err);
2187 if (!skb)
2188 return NULL;
2189
2190 skb_reserve(skb, reserve);
2191 skb_put(skb, linear);
2192 skb->data_len = len - linear;
2193 skb->len += len - linear;
2194
2195 return skb;
2196 }
2197
2198 static int packet_snd(struct socket *sock,
2199 struct msghdr *msg, size_t len)
2200 {
2201 struct sock *sk = sock->sk;
2202 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2203 struct sk_buff *skb;
2204 struct net_device *dev;
2205 __be16 proto;
2206 bool need_rls_dev = false;
2207 unsigned char *addr;
2208 int err, reserve = 0;
2209 struct virtio_net_hdr vnet_hdr = { 0 };
2210 int offset = 0;
2211 int vnet_hdr_len;
2212 struct packet_sock *po = pkt_sk(sk);
2213 unsigned short gso_type = 0;
2214 int hlen, tlen;
2215 int extra_len = 0;
2216
2217 /*
2218 * Get and verify the address.
2219 */
2220
2221 if (saddr == NULL) {
2222 dev = po->prot_hook.dev;
2223 proto = po->num;
2224 addr = NULL;
2225 } else {
2226 err = -EINVAL;
2227 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2228 goto out;
2229 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2230 goto out;
2231 proto = saddr->sll_protocol;
2232 addr = saddr->sll_addr;
2233 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2234 need_rls_dev = true;
2235 }
2236
2237 err = -ENXIO;
2238 if (dev == NULL)
2239 goto out_unlock;
2240 if (sock->type == SOCK_RAW)
2241 reserve = dev->hard_header_len;
2242
2243 err = -ENETDOWN;
2244 if (!(dev->flags & IFF_UP))
2245 goto out_unlock;
2246
2247 if (po->has_vnet_hdr) {
2248 vnet_hdr_len = sizeof(vnet_hdr);
2249
2250 err = -EINVAL;
2251 if (len < vnet_hdr_len)
2252 goto out_unlock;
2253
2254 len -= vnet_hdr_len;
2255
2256 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2257 vnet_hdr_len);
2258 if (err < 0)
2259 goto out_unlock;
2260
2261 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2262 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2263 vnet_hdr.hdr_len))
2264 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2265 vnet_hdr.csum_offset + 2;
2266
2267 err = -EINVAL;
2268 if (vnet_hdr.hdr_len > len)
2269 goto out_unlock;
2270
2271 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2272 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2273 case VIRTIO_NET_HDR_GSO_TCPV4:
2274 gso_type = SKB_GSO_TCPV4;
2275 break;
2276 case VIRTIO_NET_HDR_GSO_TCPV6:
2277 gso_type = SKB_GSO_TCPV6;
2278 break;
2279 case VIRTIO_NET_HDR_GSO_UDP:
2280 gso_type = SKB_GSO_UDP;
2281 break;
2282 default:
2283 goto out_unlock;
2284 }
2285
2286 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2287 gso_type |= SKB_GSO_TCP_ECN;
2288
2289 if (vnet_hdr.gso_size == 0)
2290 goto out_unlock;
2291
2292 }
2293 }
2294
2295 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2296 if (!netif_supports_nofcs(dev)) {
2297 err = -EPROTONOSUPPORT;
2298 goto out_unlock;
2299 }
2300 extra_len = 4; /* We're doing our own CRC */
2301 }
2302
2303 err = -EMSGSIZE;
2304 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2305 goto out_unlock;
2306
2307 err = -ENOBUFS;
2308 hlen = LL_RESERVED_SPACE(dev);
2309 tlen = dev->needed_tailroom;
2310 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2311 msg->msg_flags & MSG_DONTWAIT, &err);
2312 if (skb == NULL)
2313 goto out_unlock;
2314
2315 skb_set_network_header(skb, reserve);
2316
2317 err = -EINVAL;
2318 if (sock->type == SOCK_DGRAM &&
2319 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2320 goto out_free;
2321
2322 /* Returns -EFAULT on error */
2323 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2324 if (err)
2325 goto out_free;
2326 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2327 if (err < 0)
2328 goto out_free;
2329
2330 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2331 /* Earlier code assumed this would be a VLAN pkt,
2332 * double-check this now that we have the actual
2333 * packet in hand.
2334 */
2335 struct ethhdr *ehdr;
2336 skb_reset_mac_header(skb);
2337 ehdr = eth_hdr(skb);
2338 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2339 err = -EMSGSIZE;
2340 goto out_free;
2341 }
2342 }
2343
2344 skb->protocol = proto;
2345 skb->dev = dev;
2346 skb->priority = sk->sk_priority;
2347 skb->mark = sk->sk_mark;
2348
2349 if (po->has_vnet_hdr) {
2350 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2351 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2352 vnet_hdr.csum_offset)) {
2353 err = -EINVAL;
2354 goto out_free;
2355 }
2356 }
2357
2358 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2359 skb_shinfo(skb)->gso_type = gso_type;
2360
2361 /* Header must be checked, and gso_segs computed. */
2362 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2363 skb_shinfo(skb)->gso_segs = 0;
2364
2365 len += vnet_hdr_len;
2366 }
2367
2368 if (unlikely(extra_len == 4))
2369 skb->no_fcs = 1;
2370
2371 /*
2372 * Now send it
2373 */
2374
2375 err = dev_queue_xmit(skb);
2376 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2377 goto out_unlock;
2378
2379 if (need_rls_dev)
2380 dev_put(dev);
2381
2382 return len;
2383
2384 out_free:
2385 kfree_skb(skb);
2386 out_unlock:
2387 if (dev && need_rls_dev)
2388 dev_put(dev);
2389 out:
2390 return err;
2391 }
2392
2393 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2394 struct msghdr *msg, size_t len)
2395 {
2396 struct sock *sk = sock->sk;
2397 struct packet_sock *po = pkt_sk(sk);
2398 if (po->tx_ring.pg_vec)
2399 return tpacket_snd(po, msg);
2400 else
2401 return packet_snd(sock, msg, len);
2402 }
2403
2404 /*
2405 * Close a PACKET socket. This is fairly simple. We immediately go
2406 * to 'closed' state and remove our protocol entry in the device list.
2407 */
2408
2409 static int packet_release(struct socket *sock)
2410 {
2411 struct sock *sk = sock->sk;
2412 struct packet_sock *po;
2413 struct net *net;
2414 union tpacket_req_u req_u;
2415
2416 if (!sk)
2417 return 0;
2418
2419 net = sock_net(sk);
2420 po = pkt_sk(sk);
2421
2422 spin_lock_bh(&net->packet.sklist_lock);
2423 sk_del_node_init_rcu(sk);
2424 sock_prot_inuse_add(net, sk->sk_prot, -1);
2425 spin_unlock_bh(&net->packet.sklist_lock);
2426
2427 spin_lock(&po->bind_lock);
2428 unregister_prot_hook(sk, false);
2429 if (po->prot_hook.dev) {
2430 dev_put(po->prot_hook.dev);
2431 po->prot_hook.dev = NULL;
2432 }
2433 spin_unlock(&po->bind_lock);
2434
2435 packet_flush_mclist(sk);
2436
2437 memset(&req_u, 0, sizeof(req_u));
2438
2439 if (po->rx_ring.pg_vec)
2440 packet_set_ring(sk, &req_u, 1, 0);
2441
2442 if (po->tx_ring.pg_vec)
2443 packet_set_ring(sk, &req_u, 1, 1);
2444
2445 fanout_release(sk);
2446
2447 synchronize_net();
2448 /*
2449 * Now the socket is dead. No more input will appear.
2450 */
2451 sock_orphan(sk);
2452 sock->sk = NULL;
2453
2454 /* Purge queues */
2455
2456 skb_queue_purge(&sk->sk_receive_queue);
2457 sk_refcnt_debug_release(sk);
2458
2459 sock_put(sk);
2460 return 0;
2461 }
2462
2463 /*
2464 * Attach a packet hook.
2465 */
2466
2467 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2468 {
2469 struct packet_sock *po = pkt_sk(sk);
2470
2471 if (po->fanout) {
2472 if (dev)
2473 dev_put(dev);
2474
2475 return -EINVAL;
2476 }
2477
2478 lock_sock(sk);
2479
2480 spin_lock(&po->bind_lock);
2481 unregister_prot_hook(sk, true);
2482 po->num = protocol;
2483 po->prot_hook.type = protocol;
2484 if (po->prot_hook.dev)
2485 dev_put(po->prot_hook.dev);
2486 po->prot_hook.dev = dev;
2487
2488 po->ifindex = dev ? dev->ifindex : 0;
2489
2490 if (protocol == 0)
2491 goto out_unlock;
2492
2493 if (!dev || (dev->flags & IFF_UP)) {
2494 register_prot_hook(sk);
2495 } else {
2496 sk->sk_err = ENETDOWN;
2497 if (!sock_flag(sk, SOCK_DEAD))
2498 sk->sk_error_report(sk);
2499 }
2500
2501 out_unlock:
2502 spin_unlock(&po->bind_lock);
2503 release_sock(sk);
2504 return 0;
2505 }
2506
2507 /*
2508 * Bind a packet socket to a device
2509 */
2510
2511 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2512 int addr_len)
2513 {
2514 struct sock *sk = sock->sk;
2515 char name[15];
2516 struct net_device *dev;
2517 int err = -ENODEV;
2518
2519 /*
2520 * Check legality
2521 */
2522
2523 if (addr_len != sizeof(struct sockaddr))
2524 return -EINVAL;
2525 strlcpy(name, uaddr->sa_data, sizeof(name));
2526
2527 dev = dev_get_by_name(sock_net(sk), name);
2528 if (dev)
2529 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2530 return err;
2531 }
2532
2533 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2534 {
2535 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2536 struct sock *sk = sock->sk;
2537 struct net_device *dev = NULL;
2538 int err;
2539
2540
2541 /*
2542 * Check legality
2543 */
2544
2545 if (addr_len < sizeof(struct sockaddr_ll))
2546 return -EINVAL;
2547 if (sll->sll_family != AF_PACKET)
2548 return -EINVAL;
2549
2550 if (sll->sll_ifindex) {
2551 err = -ENODEV;
2552 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2553 if (dev == NULL)
2554 goto out;
2555 }
2556 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2557
2558 out:
2559 return err;
2560 }
2561
2562 static struct proto packet_proto = {
2563 .name = "PACKET",
2564 .owner = THIS_MODULE,
2565 .obj_size = sizeof(struct packet_sock),
2566 };
2567
2568 /*
2569 * Create a packet of type SOCK_PACKET.
2570 */
2571
2572 static int packet_create(struct net *net, struct socket *sock, int protocol,
2573 int kern)
2574 {
2575 struct sock *sk;
2576 struct packet_sock *po;
2577 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2578 int err;
2579
2580 if (!capable(CAP_NET_RAW))
2581 return -EPERM;
2582 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2583 sock->type != SOCK_PACKET)
2584 return -ESOCKTNOSUPPORT;
2585
2586 sock->state = SS_UNCONNECTED;
2587
2588 err = -ENOBUFS;
2589 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2590 if (sk == NULL)
2591 goto out;
2592
2593 sock->ops = &packet_ops;
2594 if (sock->type == SOCK_PACKET)
2595 sock->ops = &packet_ops_spkt;
2596
2597 sock_init_data(sock, sk);
2598
2599 po = pkt_sk(sk);
2600 sk->sk_family = PF_PACKET;
2601 po->num = proto;
2602
2603 sk->sk_destruct = packet_sock_destruct;
2604 sk_refcnt_debug_inc(sk);
2605
2606 /*
2607 * Attach a protocol block
2608 */
2609
2610 spin_lock_init(&po->bind_lock);
2611 mutex_init(&po->pg_vec_lock);
2612 po->prot_hook.func = packet_rcv;
2613
2614 if (sock->type == SOCK_PACKET)
2615 po->prot_hook.func = packet_rcv_spkt;
2616
2617 po->prot_hook.af_packet_priv = sk;
2618
2619 if (proto) {
2620 po->prot_hook.type = proto;
2621 register_prot_hook(sk);
2622 }
2623
2624 spin_lock_bh(&net->packet.sklist_lock);
2625 sk_add_node_rcu(sk, &net->packet.sklist);
2626 sock_prot_inuse_add(net, &packet_proto, 1);
2627 spin_unlock_bh(&net->packet.sklist_lock);
2628
2629 return 0;
2630 out:
2631 return err;
2632 }
2633
2634 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2635 {
2636 struct sock_exterr_skb *serr;
2637 struct sk_buff *skb, *skb2;
2638 int copied, err;
2639
2640 err = -EAGAIN;
2641 skb = skb_dequeue(&sk->sk_error_queue);
2642 if (skb == NULL)
2643 goto out;
2644
2645 copied = skb->len;
2646 if (copied > len) {
2647 msg->msg_flags |= MSG_TRUNC;
2648 copied = len;
2649 }
2650 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2651 if (err)
2652 goto out_free_skb;
2653
2654 sock_recv_timestamp(msg, sk, skb);
2655
2656 serr = SKB_EXT_ERR(skb);
2657 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2658 sizeof(serr->ee), &serr->ee);
2659
2660 msg->msg_flags |= MSG_ERRQUEUE;
2661 err = copied;
2662
2663 /* Reset and regenerate socket error */
2664 spin_lock_bh(&sk->sk_error_queue.lock);
2665 sk->sk_err = 0;
2666 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2667 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2668 spin_unlock_bh(&sk->sk_error_queue.lock);
2669 sk->sk_error_report(sk);
2670 } else
2671 spin_unlock_bh(&sk->sk_error_queue.lock);
2672
2673 out_free_skb:
2674 kfree_skb(skb);
2675 out:
2676 return err;
2677 }
2678
2679 /*
2680 * Pull a packet from our receive queue and hand it to the user.
2681 * If necessary we block.
2682 */
2683
2684 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2685 struct msghdr *msg, size_t len, int flags)
2686 {
2687 struct sock *sk = sock->sk;
2688 struct sk_buff *skb;
2689 int copied, err;
2690 struct sockaddr_ll *sll;
2691 int vnet_hdr_len = 0;
2692
2693 err = -EINVAL;
2694 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2695 goto out;
2696
2697 #if 0
2698 /* What error should we return now? EUNATTACH? */
2699 if (pkt_sk(sk)->ifindex < 0)
2700 return -ENODEV;
2701 #endif
2702
2703 if (flags & MSG_ERRQUEUE) {
2704 err = packet_recv_error(sk, msg, len);
2705 goto out;
2706 }
2707
2708 /*
2709 * Call the generic datagram receiver. This handles all sorts
2710 * of horrible races and re-entrancy so we can forget about it
2711 * in the protocol layers.
2712 *
2713 * Now it will return ENETDOWN, if device have just gone down,
2714 * but then it will block.
2715 */
2716
2717 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2718
2719 /*
2720 * An error occurred so return it. Because skb_recv_datagram()
2721 * handles the blocking we don't see and worry about blocking
2722 * retries.
2723 */
2724
2725 if (skb == NULL)
2726 goto out;
2727
2728 if (pkt_sk(sk)->has_vnet_hdr) {
2729 struct virtio_net_hdr vnet_hdr = { 0 };
2730
2731 err = -EINVAL;
2732 vnet_hdr_len = sizeof(vnet_hdr);
2733 if (len < vnet_hdr_len)
2734 goto out_free;
2735
2736 len -= vnet_hdr_len;
2737
2738 if (skb_is_gso(skb)) {
2739 struct skb_shared_info *sinfo = skb_shinfo(skb);
2740
2741 /* This is a hint as to how much should be linear. */
2742 vnet_hdr.hdr_len = skb_headlen(skb);
2743 vnet_hdr.gso_size = sinfo->gso_size;
2744 if (sinfo->gso_type & SKB_GSO_TCPV4)
2745 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2746 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2747 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2748 else if (sinfo->gso_type & SKB_GSO_UDP)
2749 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2750 else if (sinfo->gso_type & SKB_GSO_FCOE)
2751 goto out_free;
2752 else
2753 BUG();
2754 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2755 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2756 } else
2757 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2758
2759 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2760 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2761 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2762 vnet_hdr.csum_offset = skb->csum_offset;
2763 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2764 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2765 } /* else everything is zero */
2766
2767 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2768 vnet_hdr_len);
2769 if (err < 0)
2770 goto out_free;
2771 }
2772
2773 /*
2774 * If the address length field is there to be filled in, we fill
2775 * it in now.
2776 */
2777
2778 sll = &PACKET_SKB_CB(skb)->sa.ll;
2779 if (sock->type == SOCK_PACKET)
2780 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2781 else
2782 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
2783
2784 /*
2785 * You lose any data beyond the buffer you gave. If it worries a
2786 * user program they can ask the device for its MTU anyway.
2787 */
2788
2789 copied = skb->len;
2790 if (copied > len) {
2791 copied = len;
2792 msg->msg_flags |= MSG_TRUNC;
2793 }
2794
2795 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2796 if (err)
2797 goto out_free;
2798
2799 sock_recv_ts_and_drops(msg, sk, skb);
2800
2801 if (msg->msg_name)
2802 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2803 msg->msg_namelen);
2804
2805 if (pkt_sk(sk)->auxdata) {
2806 struct tpacket_auxdata aux;
2807
2808 aux.tp_status = TP_STATUS_USER;
2809 if (skb->ip_summed == CHECKSUM_PARTIAL)
2810 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2811 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2812 aux.tp_snaplen = skb->len;
2813 aux.tp_mac = 0;
2814 aux.tp_net = skb_network_offset(skb);
2815 if (vlan_tx_tag_present(skb)) {
2816 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2817 aux.tp_status |= TP_STATUS_VLAN_VALID;
2818 } else {
2819 aux.tp_vlan_tci = 0;
2820 }
2821 aux.tp_padding = 0;
2822 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2823 }
2824
2825 /*
2826 * Free or return the buffer as appropriate. Again this
2827 * hides all the races and re-entrancy issues from us.
2828 */
2829 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2830
2831 out_free:
2832 skb_free_datagram(sk, skb);
2833 out:
2834 return err;
2835 }
2836
2837 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2838 int *uaddr_len, int peer)
2839 {
2840 struct net_device *dev;
2841 struct sock *sk = sock->sk;
2842
2843 if (peer)
2844 return -EOPNOTSUPP;
2845
2846 uaddr->sa_family = AF_PACKET;
2847 rcu_read_lock();
2848 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2849 if (dev)
2850 strncpy(uaddr->sa_data, dev->name, 14);
2851 else
2852 memset(uaddr->sa_data, 0, 14);
2853 rcu_read_unlock();
2854 *uaddr_len = sizeof(*uaddr);
2855
2856 return 0;
2857 }
2858
2859 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2860 int *uaddr_len, int peer)
2861 {
2862 struct net_device *dev;
2863 struct sock *sk = sock->sk;
2864 struct packet_sock *po = pkt_sk(sk);
2865 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2866
2867 if (peer)
2868 return -EOPNOTSUPP;
2869
2870 sll->sll_family = AF_PACKET;
2871 sll->sll_ifindex = po->ifindex;
2872 sll->sll_protocol = po->num;
2873 sll->sll_pkttype = 0;
2874 rcu_read_lock();
2875 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2876 if (dev) {
2877 sll->sll_hatype = dev->type;
2878 sll->sll_halen = dev->addr_len;
2879 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2880 } else {
2881 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2882 sll->sll_halen = 0;
2883 }
2884 rcu_read_unlock();
2885 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2886
2887 return 0;
2888 }
2889
2890 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2891 int what)
2892 {
2893 switch (i->type) {
2894 case PACKET_MR_MULTICAST:
2895 if (i->alen != dev->addr_len)
2896 return -EINVAL;
2897 if (what > 0)
2898 return dev_mc_add(dev, i->addr);
2899 else
2900 return dev_mc_del(dev, i->addr);
2901 break;
2902 case PACKET_MR_PROMISC:
2903 return dev_set_promiscuity(dev, what);
2904 break;
2905 case PACKET_MR_ALLMULTI:
2906 return dev_set_allmulti(dev, what);
2907 break;
2908 case PACKET_MR_UNICAST:
2909 if (i->alen != dev->addr_len)
2910 return -EINVAL;
2911 if (what > 0)
2912 return dev_uc_add(dev, i->addr);
2913 else
2914 return dev_uc_del(dev, i->addr);
2915 break;
2916 default:
2917 break;
2918 }
2919 return 0;
2920 }
2921
2922 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2923 {
2924 for ( ; i; i = i->next) {
2925 if (i->ifindex == dev->ifindex)
2926 packet_dev_mc(dev, i, what);
2927 }
2928 }
2929
2930 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2931 {
2932 struct packet_sock *po = pkt_sk(sk);
2933 struct packet_mclist *ml, *i;
2934 struct net_device *dev;
2935 int err;
2936
2937 rtnl_lock();
2938
2939 err = -ENODEV;
2940 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2941 if (!dev)
2942 goto done;
2943
2944 err = -EINVAL;
2945 if (mreq->mr_alen > dev->addr_len)
2946 goto done;
2947
2948 err = -ENOBUFS;
2949 i = kmalloc(sizeof(*i), GFP_KERNEL);
2950 if (i == NULL)
2951 goto done;
2952
2953 err = 0;
2954 for (ml = po->mclist; ml; ml = ml->next) {
2955 if (ml->ifindex == mreq->mr_ifindex &&
2956 ml->type == mreq->mr_type &&
2957 ml->alen == mreq->mr_alen &&
2958 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2959 ml->count++;
2960 /* Free the new element ... */
2961 kfree(i);
2962 goto done;
2963 }
2964 }
2965
2966 i->type = mreq->mr_type;
2967 i->ifindex = mreq->mr_ifindex;
2968 i->alen = mreq->mr_alen;
2969 memcpy(i->addr, mreq->mr_address, i->alen);
2970 i->count = 1;
2971 i->next = po->mclist;
2972 po->mclist = i;
2973 err = packet_dev_mc(dev, i, 1);
2974 if (err) {
2975 po->mclist = i->next;
2976 kfree(i);
2977 }
2978
2979 done:
2980 rtnl_unlock();
2981 return err;
2982 }
2983
2984 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2985 {
2986 struct packet_mclist *ml, **mlp;
2987
2988 rtnl_lock();
2989
2990 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2991 if (ml->ifindex == mreq->mr_ifindex &&
2992 ml->type == mreq->mr_type &&
2993 ml->alen == mreq->mr_alen &&
2994 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2995 if (--ml->count == 0) {
2996 struct net_device *dev;
2997 *mlp = ml->next;
2998 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2999 if (dev)
3000 packet_dev_mc(dev, ml, -1);
3001 kfree(ml);
3002 }
3003 rtnl_unlock();
3004 return 0;
3005 }
3006 }
3007 rtnl_unlock();
3008 return -EADDRNOTAVAIL;
3009 }
3010
3011 static void packet_flush_mclist(struct sock *sk)
3012 {
3013 struct packet_sock *po = pkt_sk(sk);
3014 struct packet_mclist *ml;
3015
3016 if (!po->mclist)
3017 return;
3018
3019 rtnl_lock();
3020 while ((ml = po->mclist) != NULL) {
3021 struct net_device *dev;
3022
3023 po->mclist = ml->next;
3024 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3025 if (dev != NULL)
3026 packet_dev_mc(dev, ml, -1);
3027 kfree(ml);
3028 }
3029 rtnl_unlock();
3030 }
3031
3032 static int
3033 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3034 {
3035 struct sock *sk = sock->sk;
3036 struct packet_sock *po = pkt_sk(sk);
3037 int ret;
3038
3039 if (level != SOL_PACKET)
3040 return -ENOPROTOOPT;
3041
3042 switch (optname) {
3043 case PACKET_ADD_MEMBERSHIP:
3044 case PACKET_DROP_MEMBERSHIP:
3045 {
3046 struct packet_mreq_max mreq;
3047 int len = optlen;
3048 memset(&mreq, 0, sizeof(mreq));
3049 if (len < sizeof(struct packet_mreq))
3050 return -EINVAL;
3051 if (len > sizeof(mreq))
3052 len = sizeof(mreq);
3053 if (copy_from_user(&mreq, optval, len))
3054 return -EFAULT;
3055 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3056 return -EINVAL;
3057 if (optname == PACKET_ADD_MEMBERSHIP)
3058 ret = packet_mc_add(sk, &mreq);
3059 else
3060 ret = packet_mc_drop(sk, &mreq);
3061 return ret;
3062 }
3063
3064 case PACKET_RX_RING:
3065 case PACKET_TX_RING:
3066 {
3067 union tpacket_req_u req_u;
3068 int len;
3069
3070 switch (po->tp_version) {
3071 case TPACKET_V1:
3072 case TPACKET_V2:
3073 len = sizeof(req_u.req);
3074 break;
3075 case TPACKET_V3:
3076 default:
3077 len = sizeof(req_u.req3);
3078 break;
3079 }
3080 if (optlen < len)
3081 return -EINVAL;
3082 if (pkt_sk(sk)->has_vnet_hdr)
3083 return -EINVAL;
3084 if (copy_from_user(&req_u.req, optval, len))
3085 return -EFAULT;
3086 return packet_set_ring(sk, &req_u, 0,
3087 optname == PACKET_TX_RING);
3088 }
3089 case PACKET_COPY_THRESH:
3090 {
3091 int val;
3092
3093 if (optlen != sizeof(val))
3094 return -EINVAL;
3095 if (copy_from_user(&val, optval, sizeof(val)))
3096 return -EFAULT;
3097
3098 pkt_sk(sk)->copy_thresh = val;
3099 return 0;
3100 }
3101 case PACKET_VERSION:
3102 {
3103 int val;
3104
3105 if (optlen != sizeof(val))
3106 return -EINVAL;
3107 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3108 return -EBUSY;
3109 if (copy_from_user(&val, optval, sizeof(val)))
3110 return -EFAULT;
3111 switch (val) {
3112 case TPACKET_V1:
3113 case TPACKET_V2:
3114 case TPACKET_V3:
3115 po->tp_version = val;
3116 return 0;
3117 default:
3118 return -EINVAL;
3119 }
3120 }
3121 case PACKET_RESERVE:
3122 {
3123 unsigned int val;
3124
3125 if (optlen != sizeof(val))
3126 return -EINVAL;
3127 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3128 return -EBUSY;
3129 if (copy_from_user(&val, optval, sizeof(val)))
3130 return -EFAULT;
3131 po->tp_reserve = val;
3132 return 0;
3133 }
3134 case PACKET_LOSS:
3135 {
3136 unsigned int val;
3137
3138 if (optlen != sizeof(val))
3139 return -EINVAL;
3140 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3141 return -EBUSY;
3142 if (copy_from_user(&val, optval, sizeof(val)))
3143 return -EFAULT;
3144 po->tp_loss = !!val;
3145 return 0;
3146 }
3147 case PACKET_AUXDATA:
3148 {
3149 int val;
3150
3151 if (optlen < sizeof(val))
3152 return -EINVAL;
3153 if (copy_from_user(&val, optval, sizeof(val)))
3154 return -EFAULT;
3155
3156 po->auxdata = !!val;
3157 return 0;
3158 }
3159 case PACKET_ORIGDEV:
3160 {
3161 int val;
3162
3163 if (optlen < sizeof(val))
3164 return -EINVAL;
3165 if (copy_from_user(&val, optval, sizeof(val)))
3166 return -EFAULT;
3167
3168 po->origdev = !!val;
3169 return 0;
3170 }
3171 case PACKET_VNET_HDR:
3172 {
3173 int val;
3174
3175 if (sock->type != SOCK_RAW)
3176 return -EINVAL;
3177 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3178 return -EBUSY;
3179 if (optlen < sizeof(val))
3180 return -EINVAL;
3181 if (copy_from_user(&val, optval, sizeof(val)))
3182 return -EFAULT;
3183
3184 po->has_vnet_hdr = !!val;
3185 return 0;
3186 }
3187 case PACKET_TIMESTAMP:
3188 {
3189 int val;
3190
3191 if (optlen != sizeof(val))
3192 return -EINVAL;
3193 if (copy_from_user(&val, optval, sizeof(val)))
3194 return -EFAULT;
3195
3196 po->tp_tstamp = val;
3197 return 0;
3198 }
3199 case PACKET_FANOUT:
3200 {
3201 int val;
3202
3203 if (optlen != sizeof(val))
3204 return -EINVAL;
3205 if (copy_from_user(&val, optval, sizeof(val)))
3206 return -EFAULT;
3207
3208 return fanout_add(sk, val & 0xffff, val >> 16);
3209 }
3210 default:
3211 return -ENOPROTOOPT;
3212 }
3213 }
3214
3215 static int packet_getsockopt(struct socket *sock, int level, int optname,
3216 char __user *optval, int __user *optlen)
3217 {
3218 int len;
3219 int val, lv = sizeof(val);
3220 struct sock *sk = sock->sk;
3221 struct packet_sock *po = pkt_sk(sk);
3222 void *data = &val;
3223 struct tpacket_stats st;
3224 union tpacket_stats_u st_u;
3225
3226 if (level != SOL_PACKET)
3227 return -ENOPROTOOPT;
3228
3229 if (get_user(len, optlen))
3230 return -EFAULT;
3231
3232 if (len < 0)
3233 return -EINVAL;
3234
3235 switch (optname) {
3236 case PACKET_STATISTICS:
3237 spin_lock_bh(&sk->sk_receive_queue.lock);
3238 if (po->tp_version == TPACKET_V3) {
3239 lv = sizeof(struct tpacket_stats_v3);
3240 memcpy(&st_u.stats3, &po->stats,
3241 sizeof(struct tpacket_stats));
3242 st_u.stats3.tp_freeze_q_cnt =
3243 po->stats_u.stats3.tp_freeze_q_cnt;
3244 st_u.stats3.tp_packets += po->stats.tp_drops;
3245 data = &st_u.stats3;
3246 } else {
3247 lv = sizeof(struct tpacket_stats);
3248 st = po->stats;
3249 st.tp_packets += st.tp_drops;
3250 data = &st;
3251 }
3252 memset(&po->stats, 0, sizeof(st));
3253 spin_unlock_bh(&sk->sk_receive_queue.lock);
3254 break;
3255 case PACKET_AUXDATA:
3256 val = po->auxdata;
3257 break;
3258 case PACKET_ORIGDEV:
3259 val = po->origdev;
3260 break;
3261 case PACKET_VNET_HDR:
3262 val = po->has_vnet_hdr;
3263 break;
3264 case PACKET_VERSION:
3265 val = po->tp_version;
3266 break;
3267 case PACKET_HDRLEN:
3268 if (len > sizeof(int))
3269 len = sizeof(int);
3270 if (copy_from_user(&val, optval, len))
3271 return -EFAULT;
3272 switch (val) {
3273 case TPACKET_V1:
3274 val = sizeof(struct tpacket_hdr);
3275 break;
3276 case TPACKET_V2:
3277 val = sizeof(struct tpacket2_hdr);
3278 break;
3279 case TPACKET_V3:
3280 val = sizeof(struct tpacket3_hdr);
3281 break;
3282 default:
3283 return -EINVAL;
3284 }
3285 break;
3286 case PACKET_RESERVE:
3287 val = po->tp_reserve;
3288 break;
3289 case PACKET_LOSS:
3290 val = po->tp_loss;
3291 break;
3292 case PACKET_TIMESTAMP:
3293 val = po->tp_tstamp;
3294 break;
3295 case PACKET_FANOUT:
3296 val = (po->fanout ?
3297 ((u32)po->fanout->id |
3298 ((u32)po->fanout->type << 16)) :
3299 0);
3300 break;
3301 default:
3302 return -ENOPROTOOPT;
3303 }
3304
3305 if (len > lv)
3306 len = lv;
3307 if (put_user(len, optlen))
3308 return -EFAULT;
3309 if (copy_to_user(optval, data, len))
3310 return -EFAULT;
3311 return 0;
3312 }
3313
3314
3315 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3316 {
3317 struct sock *sk;
3318 struct hlist_node *node;
3319 struct net_device *dev = data;
3320 struct net *net = dev_net(dev);
3321
3322 rcu_read_lock();
3323 sk_for_each_rcu(sk, node, &net->packet.sklist) {
3324 struct packet_sock *po = pkt_sk(sk);
3325
3326 switch (msg) {
3327 case NETDEV_UNREGISTER:
3328 if (po->mclist)
3329 packet_dev_mclist(dev, po->mclist, -1);
3330 /* fallthrough */
3331
3332 case NETDEV_DOWN:
3333 if (dev->ifindex == po->ifindex) {
3334 spin_lock(&po->bind_lock);
3335 if (po->running) {
3336 __unregister_prot_hook(sk, false);
3337 sk->sk_err = ENETDOWN;
3338 if (!sock_flag(sk, SOCK_DEAD))
3339 sk->sk_error_report(sk);
3340 }
3341 if (msg == NETDEV_UNREGISTER) {
3342 po->ifindex = -1;
3343 if (po->prot_hook.dev)
3344 dev_put(po->prot_hook.dev);
3345 po->prot_hook.dev = NULL;
3346 }
3347 spin_unlock(&po->bind_lock);
3348 }
3349 break;
3350 case NETDEV_UP:
3351 if (dev->ifindex == po->ifindex) {
3352 spin_lock(&po->bind_lock);
3353 if (po->num)
3354 register_prot_hook(sk);
3355 spin_unlock(&po->bind_lock);
3356 }
3357 break;
3358 }
3359 }
3360 rcu_read_unlock();
3361 return NOTIFY_DONE;
3362 }
3363
3364
3365 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3366 unsigned long arg)
3367 {
3368 struct sock *sk = sock->sk;
3369
3370 switch (cmd) {
3371 case SIOCOUTQ:
3372 {
3373 int amount = sk_wmem_alloc_get(sk);
3374
3375 return put_user(amount, (int __user *)arg);
3376 }
3377 case SIOCINQ:
3378 {
3379 struct sk_buff *skb;
3380 int amount = 0;
3381
3382 spin_lock_bh(&sk->sk_receive_queue.lock);
3383 skb = skb_peek(&sk->sk_receive_queue);
3384 if (skb)
3385 amount = skb->len;
3386 spin_unlock_bh(&sk->sk_receive_queue.lock);
3387 return put_user(amount, (int __user *)arg);
3388 }
3389 case SIOCGSTAMP:
3390 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3391 case SIOCGSTAMPNS:
3392 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3393
3394 #ifdef CONFIG_INET
3395 case SIOCADDRT:
3396 case SIOCDELRT:
3397 case SIOCDARP:
3398 case SIOCGARP:
3399 case SIOCSARP:
3400 case SIOCGIFADDR:
3401 case SIOCSIFADDR:
3402 case SIOCGIFBRDADDR:
3403 case SIOCSIFBRDADDR:
3404 case SIOCGIFNETMASK:
3405 case SIOCSIFNETMASK:
3406 case SIOCGIFDSTADDR:
3407 case SIOCSIFDSTADDR:
3408 case SIOCSIFFLAGS:
3409 return inet_dgram_ops.ioctl(sock, cmd, arg);
3410 #endif
3411
3412 default:
3413 return -ENOIOCTLCMD;
3414 }
3415 return 0;
3416 }
3417
3418 static unsigned int packet_poll(struct file *file, struct socket *sock,
3419 poll_table *wait)
3420 {
3421 struct sock *sk = sock->sk;
3422 struct packet_sock *po = pkt_sk(sk);
3423 unsigned int mask = datagram_poll(file, sock, wait);
3424
3425 spin_lock_bh(&sk->sk_receive_queue.lock);
3426 if (po->rx_ring.pg_vec) {
3427 if (!packet_previous_rx_frame(po, &po->rx_ring,
3428 TP_STATUS_KERNEL))
3429 mask |= POLLIN | POLLRDNORM;
3430 }
3431 spin_unlock_bh(&sk->sk_receive_queue.lock);
3432 spin_lock_bh(&sk->sk_write_queue.lock);
3433 if (po->tx_ring.pg_vec) {
3434 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3435 mask |= POLLOUT | POLLWRNORM;
3436 }
3437 spin_unlock_bh(&sk->sk_write_queue.lock);
3438 return mask;
3439 }
3440
3441
3442 /* Dirty? Well, I still did not learn better way to account
3443 * for user mmaps.
3444 */
3445
3446 static void packet_mm_open(struct vm_area_struct *vma)
3447 {
3448 struct file *file = vma->vm_file;
3449 struct socket *sock = file->private_data;
3450 struct sock *sk = sock->sk;
3451
3452 if (sk)
3453 atomic_inc(&pkt_sk(sk)->mapped);
3454 }
3455
3456 static void packet_mm_close(struct vm_area_struct *vma)
3457 {
3458 struct file *file = vma->vm_file;
3459 struct socket *sock = file->private_data;
3460 struct sock *sk = sock->sk;
3461
3462 if (sk)
3463 atomic_dec(&pkt_sk(sk)->mapped);
3464 }
3465
3466 static const struct vm_operations_struct packet_mmap_ops = {
3467 .open = packet_mm_open,
3468 .close = packet_mm_close,
3469 };
3470
3471 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3472 unsigned int len)
3473 {
3474 int i;
3475
3476 for (i = 0; i < len; i++) {
3477 if (likely(pg_vec[i].buffer)) {
3478 if (is_vmalloc_addr(pg_vec[i].buffer))
3479 vfree(pg_vec[i].buffer);
3480 else
3481 free_pages((unsigned long)pg_vec[i].buffer,
3482 order);
3483 pg_vec[i].buffer = NULL;
3484 }
3485 }
3486 kfree(pg_vec);
3487 }
3488
3489 static char *alloc_one_pg_vec_page(unsigned long order)
3490 {
3491 char *buffer = NULL;
3492 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3493 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3494
3495 buffer = (char *) __get_free_pages(gfp_flags, order);
3496
3497 if (buffer)
3498 return buffer;
3499
3500 /*
3501 * __get_free_pages failed, fall back to vmalloc
3502 */
3503 buffer = vzalloc((1 << order) * PAGE_SIZE);
3504
3505 if (buffer)
3506 return buffer;
3507
3508 /*
3509 * vmalloc failed, lets dig into swap here
3510 */
3511 gfp_flags &= ~__GFP_NORETRY;
3512 buffer = (char *)__get_free_pages(gfp_flags, order);
3513 if (buffer)
3514 return buffer;
3515
3516 /*
3517 * complete and utter failure
3518 */
3519 return NULL;
3520 }
3521
3522 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3523 {
3524 unsigned int block_nr = req->tp_block_nr;
3525 struct pgv *pg_vec;
3526 int i;
3527
3528 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3529 if (unlikely(!pg_vec))
3530 goto out;
3531
3532 for (i = 0; i < block_nr; i++) {
3533 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3534 if (unlikely(!pg_vec[i].buffer))
3535 goto out_free_pgvec;
3536 }
3537
3538 out:
3539 return pg_vec;
3540
3541 out_free_pgvec:
3542 free_pg_vec(pg_vec, order, block_nr);
3543 pg_vec = NULL;
3544 goto out;
3545 }
3546
3547 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3548 int closing, int tx_ring)
3549 {
3550 struct pgv *pg_vec = NULL;
3551 struct packet_sock *po = pkt_sk(sk);
3552 int was_running, order = 0;
3553 struct packet_ring_buffer *rb;
3554 struct sk_buff_head *rb_queue;
3555 __be16 num;
3556 int err = -EINVAL;
3557 /* Added to avoid minimal code churn */
3558 struct tpacket_req *req = &req_u->req;
3559
3560 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3561 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3562 WARN(1, "Tx-ring is not supported.\n");
3563 goto out;
3564 }
3565
3566 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3567 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3568
3569 err = -EBUSY;
3570 if (!closing) {
3571 if (atomic_read(&po->mapped))
3572 goto out;
3573 if (atomic_read(&rb->pending))
3574 goto out;
3575 }
3576
3577 if (req->tp_block_nr) {
3578 /* Sanity tests and some calculations */
3579 err = -EBUSY;
3580 if (unlikely(rb->pg_vec))
3581 goto out;
3582
3583 switch (po->tp_version) {
3584 case TPACKET_V1:
3585 po->tp_hdrlen = TPACKET_HDRLEN;
3586 break;
3587 case TPACKET_V2:
3588 po->tp_hdrlen = TPACKET2_HDRLEN;
3589 break;
3590 case TPACKET_V3:
3591 po->tp_hdrlen = TPACKET3_HDRLEN;
3592 break;
3593 }
3594
3595 err = -EINVAL;
3596 if (unlikely((int)req->tp_block_size <= 0))
3597 goto out;
3598 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3599 goto out;
3600 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3601 po->tp_reserve))
3602 goto out;
3603 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3604 goto out;
3605
3606 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3607 if (unlikely(rb->frames_per_block <= 0))
3608 goto out;
3609 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3610 req->tp_frame_nr))
3611 goto out;
3612
3613 err = -ENOMEM;
3614 order = get_order(req->tp_block_size);
3615 pg_vec = alloc_pg_vec(req, order);
3616 if (unlikely(!pg_vec))
3617 goto out;
3618 switch (po->tp_version) {
3619 case TPACKET_V3:
3620 /* Transmit path is not supported. We checked
3621 * it above but just being paranoid
3622 */
3623 if (!tx_ring)
3624 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3625 break;
3626 default:
3627 break;
3628 }
3629 }
3630 /* Done */
3631 else {
3632 err = -EINVAL;
3633 if (unlikely(req->tp_frame_nr))
3634 goto out;
3635 }
3636
3637 lock_sock(sk);
3638
3639 /* Detach socket from network */
3640 spin_lock(&po->bind_lock);
3641 was_running = po->running;
3642 num = po->num;
3643 if (was_running) {
3644 po->num = 0;
3645 __unregister_prot_hook(sk, false);
3646 }
3647 spin_unlock(&po->bind_lock);
3648
3649 synchronize_net();
3650
3651 err = -EBUSY;
3652 mutex_lock(&po->pg_vec_lock);
3653 if (closing || atomic_read(&po->mapped) == 0) {
3654 err = 0;
3655 spin_lock_bh(&rb_queue->lock);
3656 swap(rb->pg_vec, pg_vec);
3657 rb->frame_max = (req->tp_frame_nr - 1);
3658 rb->head = 0;
3659 rb->frame_size = req->tp_frame_size;
3660 spin_unlock_bh(&rb_queue->lock);
3661
3662 swap(rb->pg_vec_order, order);
3663 swap(rb->pg_vec_len, req->tp_block_nr);
3664
3665 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3666 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3667 tpacket_rcv : packet_rcv;
3668 skb_queue_purge(rb_queue);
3669 if (atomic_read(&po->mapped))
3670 pr_err("packet_mmap: vma is busy: %d\n",
3671 atomic_read(&po->mapped));
3672 }
3673 mutex_unlock(&po->pg_vec_lock);
3674
3675 spin_lock(&po->bind_lock);
3676 if (was_running) {
3677 po->num = num;
3678 register_prot_hook(sk);
3679 }
3680 spin_unlock(&po->bind_lock);
3681 if (closing && (po->tp_version > TPACKET_V2)) {
3682 /* Because we don't support block-based V3 on tx-ring */
3683 if (!tx_ring)
3684 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3685 }
3686 release_sock(sk);
3687
3688 if (pg_vec)
3689 free_pg_vec(pg_vec, order, req->tp_block_nr);
3690 out:
3691 return err;
3692 }
3693
3694 static int packet_mmap(struct file *file, struct socket *sock,
3695 struct vm_area_struct *vma)
3696 {
3697 struct sock *sk = sock->sk;
3698 struct packet_sock *po = pkt_sk(sk);
3699 unsigned long size, expected_size;
3700 struct packet_ring_buffer *rb;
3701 unsigned long start;
3702 int err = -EINVAL;
3703 int i;
3704
3705 if (vma->vm_pgoff)
3706 return -EINVAL;
3707
3708 mutex_lock(&po->pg_vec_lock);
3709
3710 expected_size = 0;
3711 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3712 if (rb->pg_vec) {
3713 expected_size += rb->pg_vec_len
3714 * rb->pg_vec_pages
3715 * PAGE_SIZE;
3716 }
3717 }
3718
3719 if (expected_size == 0)
3720 goto out;
3721
3722 size = vma->vm_end - vma->vm_start;
3723 if (size != expected_size)
3724 goto out;
3725
3726 start = vma->vm_start;
3727 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3728 if (rb->pg_vec == NULL)
3729 continue;
3730
3731 for (i = 0; i < rb->pg_vec_len; i++) {
3732 struct page *page;
3733 void *kaddr = rb->pg_vec[i].buffer;
3734 int pg_num;
3735
3736 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3737 page = pgv_to_page(kaddr);
3738 err = vm_insert_page(vma, start, page);
3739 if (unlikely(err))
3740 goto out;
3741 start += PAGE_SIZE;
3742 kaddr += PAGE_SIZE;
3743 }
3744 }
3745 }
3746
3747 atomic_inc(&po->mapped);
3748 vma->vm_ops = &packet_mmap_ops;
3749 err = 0;
3750
3751 out:
3752 mutex_unlock(&po->pg_vec_lock);
3753 return err;
3754 }
3755
3756 static const struct proto_ops packet_ops_spkt = {
3757 .family = PF_PACKET,
3758 .owner = THIS_MODULE,
3759 .release = packet_release,
3760 .bind = packet_bind_spkt,
3761 .connect = sock_no_connect,
3762 .socketpair = sock_no_socketpair,
3763 .accept = sock_no_accept,
3764 .getname = packet_getname_spkt,
3765 .poll = datagram_poll,
3766 .ioctl = packet_ioctl,
3767 .listen = sock_no_listen,
3768 .shutdown = sock_no_shutdown,
3769 .setsockopt = sock_no_setsockopt,
3770 .getsockopt = sock_no_getsockopt,
3771 .sendmsg = packet_sendmsg_spkt,
3772 .recvmsg = packet_recvmsg,
3773 .mmap = sock_no_mmap,
3774 .sendpage = sock_no_sendpage,
3775 };
3776
3777 static const struct proto_ops packet_ops = {
3778 .family = PF_PACKET,
3779 .owner = THIS_MODULE,
3780 .release = packet_release,
3781 .bind = packet_bind,
3782 .connect = sock_no_connect,
3783 .socketpair = sock_no_socketpair,
3784 .accept = sock_no_accept,
3785 .getname = packet_getname,
3786 .poll = packet_poll,
3787 .ioctl = packet_ioctl,
3788 .listen = sock_no_listen,
3789 .shutdown = sock_no_shutdown,
3790 .setsockopt = packet_setsockopt,
3791 .getsockopt = packet_getsockopt,
3792 .sendmsg = packet_sendmsg,
3793 .recvmsg = packet_recvmsg,
3794 .mmap = packet_mmap,
3795 .sendpage = sock_no_sendpage,
3796 };
3797
3798 static const struct net_proto_family packet_family_ops = {
3799 .family = PF_PACKET,
3800 .create = packet_create,
3801 .owner = THIS_MODULE,
3802 };
3803
3804 static struct notifier_block packet_netdev_notifier = {
3805 .notifier_call = packet_notifier,
3806 };
3807
3808 #ifdef CONFIG_PROC_FS
3809
3810 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3811 __acquires(RCU)
3812 {
3813 struct net *net = seq_file_net(seq);
3814
3815 rcu_read_lock();
3816 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3817 }
3818
3819 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3820 {
3821 struct net *net = seq_file_net(seq);
3822 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3823 }
3824
3825 static void packet_seq_stop(struct seq_file *seq, void *v)
3826 __releases(RCU)
3827 {
3828 rcu_read_unlock();
3829 }
3830
3831 static int packet_seq_show(struct seq_file *seq, void *v)
3832 {
3833 if (v == SEQ_START_TOKEN)
3834 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3835 else {
3836 struct sock *s = sk_entry(v);
3837 const struct packet_sock *po = pkt_sk(s);
3838
3839 seq_printf(seq,
3840 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3841 s,
3842 atomic_read(&s->sk_refcnt),
3843 s->sk_type,
3844 ntohs(po->num),
3845 po->ifindex,
3846 po->running,
3847 atomic_read(&s->sk_rmem_alloc),
3848 sock_i_uid(s),
3849 sock_i_ino(s));
3850 }
3851
3852 return 0;
3853 }
3854
3855 static const struct seq_operations packet_seq_ops = {
3856 .start = packet_seq_start,
3857 .next = packet_seq_next,
3858 .stop = packet_seq_stop,
3859 .show = packet_seq_show,
3860 };
3861
3862 static int packet_seq_open(struct inode *inode, struct file *file)
3863 {
3864 return seq_open_net(inode, file, &packet_seq_ops,
3865 sizeof(struct seq_net_private));
3866 }
3867
3868 static const struct file_operations packet_seq_fops = {
3869 .owner = THIS_MODULE,
3870 .open = packet_seq_open,
3871 .read = seq_read,
3872 .llseek = seq_lseek,
3873 .release = seq_release_net,
3874 };
3875
3876 #endif
3877
3878 static int __net_init packet_net_init(struct net *net)
3879 {
3880 spin_lock_init(&net->packet.sklist_lock);
3881 INIT_HLIST_HEAD(&net->packet.sklist);
3882
3883 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
3884 return -ENOMEM;
3885
3886 return 0;
3887 }
3888
3889 static void __net_exit packet_net_exit(struct net *net)
3890 {
3891 proc_net_remove(net, "packet");
3892 }
3893
3894 static struct pernet_operations packet_net_ops = {
3895 .init = packet_net_init,
3896 .exit = packet_net_exit,
3897 };
3898
3899
3900 static void __exit packet_exit(void)
3901 {
3902 unregister_netdevice_notifier(&packet_netdev_notifier);
3903 unregister_pernet_subsys(&packet_net_ops);
3904 sock_unregister(PF_PACKET);
3905 proto_unregister(&packet_proto);
3906 }
3907
3908 static int __init packet_init(void)
3909 {
3910 int rc = proto_register(&packet_proto, 0);
3911
3912 if (rc != 0)
3913 goto out;
3914
3915 sock_register(&packet_family_ops);
3916 register_pernet_subsys(&packet_net_ops);
3917 register_netdevice_notifier(&packet_netdev_notifier);
3918 out:
3919 return rc;
3920 }
3921
3922 module_init(packet_init);
3923 module_exit(packet_exit);
3924 MODULE_LICENSE("GPL");
3925 MODULE_ALIAS_NETPROTO(PF_PACKET);
Linux kernel - Deliverables
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