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Merge branch 'for-airlied' of git://people.freedesktop.org/~danvet/drm-intel into...
[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 bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1277 {
1278 if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1279 return true;
1280
1281 return false;
1282 }
1283
1284 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1285 {
1286 struct packet_sock *po = pkt_sk(sk);
1287 struct packet_fanout *f, *match;
1288 u8 type = type_flags & 0xff;
1289 u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
1290 int err;
1291
1292 switch (type) {
1293 case PACKET_FANOUT_HASH:
1294 case PACKET_FANOUT_LB:
1295 case PACKET_FANOUT_CPU:
1296 break;
1297 default:
1298 return -EINVAL;
1299 }
1300
1301 if (!po->running)
1302 return -EINVAL;
1303
1304 if (po->fanout)
1305 return -EALREADY;
1306
1307 mutex_lock(&fanout_mutex);
1308 match = NULL;
1309 list_for_each_entry(f, &fanout_list, list) {
1310 if (f->id == id &&
1311 read_pnet(&f->net) == sock_net(sk)) {
1312 match = f;
1313 break;
1314 }
1315 }
1316 err = -EINVAL;
1317 if (match && match->defrag != defrag)
1318 goto out;
1319 if (!match) {
1320 err = -ENOMEM;
1321 match = kzalloc(sizeof(*match), GFP_KERNEL);
1322 if (!match)
1323 goto out;
1324 write_pnet(&match->net, sock_net(sk));
1325 match->id = id;
1326 match->type = type;
1327 match->defrag = defrag;
1328 atomic_set(&match->rr_cur, 0);
1329 INIT_LIST_HEAD(&match->list);
1330 spin_lock_init(&match->lock);
1331 atomic_set(&match->sk_ref, 0);
1332 match->prot_hook.type = po->prot_hook.type;
1333 match->prot_hook.dev = po->prot_hook.dev;
1334 match->prot_hook.func = packet_rcv_fanout;
1335 match->prot_hook.af_packet_priv = match;
1336 match->prot_hook.id_match = match_fanout_group;
1337 dev_add_pack(&match->prot_hook);
1338 list_add(&match->list, &fanout_list);
1339 }
1340 err = -EINVAL;
1341 if (match->type == type &&
1342 match->prot_hook.type == po->prot_hook.type &&
1343 match->prot_hook.dev == po->prot_hook.dev) {
1344 err = -ENOSPC;
1345 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1346 __dev_remove_pack(&po->prot_hook);
1347 po->fanout = match;
1348 atomic_inc(&match->sk_ref);
1349 __fanout_link(sk, po);
1350 err = 0;
1351 }
1352 }
1353 out:
1354 mutex_unlock(&fanout_mutex);
1355 return err;
1356 }
1357
1358 static void fanout_release(struct sock *sk)
1359 {
1360 struct packet_sock *po = pkt_sk(sk);
1361 struct packet_fanout *f;
1362
1363 f = po->fanout;
1364 if (!f)
1365 return;
1366
1367 po->fanout = NULL;
1368
1369 mutex_lock(&fanout_mutex);
1370 if (atomic_dec_and_test(&f->sk_ref)) {
1371 list_del(&f->list);
1372 dev_remove_pack(&f->prot_hook);
1373 kfree(f);
1374 }
1375 mutex_unlock(&fanout_mutex);
1376 }
1377
1378 static const struct proto_ops packet_ops;
1379
1380 static const struct proto_ops packet_ops_spkt;
1381
1382 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1383 struct packet_type *pt, struct net_device *orig_dev)
1384 {
1385 struct sock *sk;
1386 struct sockaddr_pkt *spkt;
1387
1388 /*
1389 * When we registered the protocol we saved the socket in the data
1390 * field for just this event.
1391 */
1392
1393 sk = pt->af_packet_priv;
1394
1395 /*
1396 * Yank back the headers [hope the device set this
1397 * right or kerboom...]
1398 *
1399 * Incoming packets have ll header pulled,
1400 * push it back.
1401 *
1402 * For outgoing ones skb->data == skb_mac_header(skb)
1403 * so that this procedure is noop.
1404 */
1405
1406 if (skb->pkt_type == PACKET_LOOPBACK)
1407 goto out;
1408
1409 if (!net_eq(dev_net(dev), sock_net(sk)))
1410 goto out;
1411
1412 skb = skb_share_check(skb, GFP_ATOMIC);
1413 if (skb == NULL)
1414 goto oom;
1415
1416 /* drop any routing info */
1417 skb_dst_drop(skb);
1418
1419 /* drop conntrack reference */
1420 nf_reset(skb);
1421
1422 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1423
1424 skb_push(skb, skb->data - skb_mac_header(skb));
1425
1426 /*
1427 * The SOCK_PACKET socket receives _all_ frames.
1428 */
1429
1430 spkt->spkt_family = dev->type;
1431 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1432 spkt->spkt_protocol = skb->protocol;
1433
1434 /*
1435 * Charge the memory to the socket. This is done specifically
1436 * to prevent sockets using all the memory up.
1437 */
1438
1439 if (sock_queue_rcv_skb(sk, skb) == 0)
1440 return 0;
1441
1442 out:
1443 kfree_skb(skb);
1444 oom:
1445 return 0;
1446 }
1447
1448
1449 /*
1450 * Output a raw packet to a device layer. This bypasses all the other
1451 * protocol layers and you must therefore supply it with a complete frame
1452 */
1453
1454 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1455 struct msghdr *msg, size_t len)
1456 {
1457 struct sock *sk = sock->sk;
1458 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1459 struct sk_buff *skb = NULL;
1460 struct net_device *dev;
1461 __be16 proto = 0;
1462 int err;
1463 int extra_len = 0;
1464
1465 /*
1466 * Get and verify the address.
1467 */
1468
1469 if (saddr) {
1470 if (msg->msg_namelen < sizeof(struct sockaddr))
1471 return -EINVAL;
1472 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1473 proto = saddr->spkt_protocol;
1474 } else
1475 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1476
1477 /*
1478 * Find the device first to size check it
1479 */
1480
1481 saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1482 retry:
1483 rcu_read_lock();
1484 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1485 err = -ENODEV;
1486 if (dev == NULL)
1487 goto out_unlock;
1488
1489 err = -ENETDOWN;
1490 if (!(dev->flags & IFF_UP))
1491 goto out_unlock;
1492
1493 /*
1494 * You may not queue a frame bigger than the mtu. This is the lowest level
1495 * raw protocol and you must do your own fragmentation at this level.
1496 */
1497
1498 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1499 if (!netif_supports_nofcs(dev)) {
1500 err = -EPROTONOSUPPORT;
1501 goto out_unlock;
1502 }
1503 extra_len = 4; /* We're doing our own CRC */
1504 }
1505
1506 err = -EMSGSIZE;
1507 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1508 goto out_unlock;
1509
1510 if (!skb) {
1511 size_t reserved = LL_RESERVED_SPACE(dev);
1512 int tlen = dev->needed_tailroom;
1513 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1514
1515 rcu_read_unlock();
1516 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1517 if (skb == NULL)
1518 return -ENOBUFS;
1519 /* FIXME: Save some space for broken drivers that write a hard
1520 * header at transmission time by themselves. PPP is the notable
1521 * one here. This should really be fixed at the driver level.
1522 */
1523 skb_reserve(skb, reserved);
1524 skb_reset_network_header(skb);
1525
1526 /* Try to align data part correctly */
1527 if (hhlen) {
1528 skb->data -= hhlen;
1529 skb->tail -= hhlen;
1530 if (len < hhlen)
1531 skb_reset_network_header(skb);
1532 }
1533 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1534 if (err)
1535 goto out_free;
1536 goto retry;
1537 }
1538
1539 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1540 /* Earlier code assumed this would be a VLAN pkt,
1541 * double-check this now that we have the actual
1542 * packet in hand.
1543 */
1544 struct ethhdr *ehdr;
1545 skb_reset_mac_header(skb);
1546 ehdr = eth_hdr(skb);
1547 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1548 err = -EMSGSIZE;
1549 goto out_unlock;
1550 }
1551 }
1552
1553 skb->protocol = proto;
1554 skb->dev = dev;
1555 skb->priority = sk->sk_priority;
1556 skb->mark = sk->sk_mark;
1557 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1558 if (err < 0)
1559 goto out_unlock;
1560
1561 if (unlikely(extra_len == 4))
1562 skb->no_fcs = 1;
1563
1564 dev_queue_xmit(skb);
1565 rcu_read_unlock();
1566 return len;
1567
1568 out_unlock:
1569 rcu_read_unlock();
1570 out_free:
1571 kfree_skb(skb);
1572 return err;
1573 }
1574
1575 static unsigned int run_filter(const struct sk_buff *skb,
1576 const struct sock *sk,
1577 unsigned int res)
1578 {
1579 struct sk_filter *filter;
1580
1581 rcu_read_lock();
1582 filter = rcu_dereference(sk->sk_filter);
1583 if (filter != NULL)
1584 res = SK_RUN_FILTER(filter, skb);
1585 rcu_read_unlock();
1586
1587 return res;
1588 }
1589
1590 /*
1591 * This function makes lazy skb cloning in hope that most of packets
1592 * are discarded by BPF.
1593 *
1594 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1595 * and skb->cb are mangled. It works because (and until) packets
1596 * falling here are owned by current CPU. Output packets are cloned
1597 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1598 * sequencially, so that if we return skb to original state on exit,
1599 * we will not harm anyone.
1600 */
1601
1602 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1603 struct packet_type *pt, struct net_device *orig_dev)
1604 {
1605 struct sock *sk;
1606 struct sockaddr_ll *sll;
1607 struct packet_sock *po;
1608 u8 *skb_head = skb->data;
1609 int skb_len = skb->len;
1610 unsigned int snaplen, res;
1611
1612 if (skb->pkt_type == PACKET_LOOPBACK)
1613 goto drop;
1614
1615 sk = pt->af_packet_priv;
1616 po = pkt_sk(sk);
1617
1618 if (!net_eq(dev_net(dev), sock_net(sk)))
1619 goto drop;
1620
1621 skb->dev = dev;
1622
1623 if (dev->header_ops) {
1624 /* The device has an explicit notion of ll header,
1625 * exported to higher levels.
1626 *
1627 * Otherwise, the device hides details of its frame
1628 * structure, so that corresponding packet head is
1629 * never delivered to user.
1630 */
1631 if (sk->sk_type != SOCK_DGRAM)
1632 skb_push(skb, skb->data - skb_mac_header(skb));
1633 else if (skb->pkt_type == PACKET_OUTGOING) {
1634 /* Special case: outgoing packets have ll header at head */
1635 skb_pull(skb, skb_network_offset(skb));
1636 }
1637 }
1638
1639 snaplen = skb->len;
1640
1641 res = run_filter(skb, sk, snaplen);
1642 if (!res)
1643 goto drop_n_restore;
1644 if (snaplen > res)
1645 snaplen = res;
1646
1647 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1648 goto drop_n_acct;
1649
1650 if (skb_shared(skb)) {
1651 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1652 if (nskb == NULL)
1653 goto drop_n_acct;
1654
1655 if (skb_head != skb->data) {
1656 skb->data = skb_head;
1657 skb->len = skb_len;
1658 }
1659 consume_skb(skb);
1660 skb = nskb;
1661 }
1662
1663 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1664 sizeof(skb->cb));
1665
1666 sll = &PACKET_SKB_CB(skb)->sa.ll;
1667 sll->sll_family = AF_PACKET;
1668 sll->sll_hatype = dev->type;
1669 sll->sll_protocol = skb->protocol;
1670 sll->sll_pkttype = skb->pkt_type;
1671 if (unlikely(po->origdev))
1672 sll->sll_ifindex = orig_dev->ifindex;
1673 else
1674 sll->sll_ifindex = dev->ifindex;
1675
1676 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1677
1678 PACKET_SKB_CB(skb)->origlen = skb->len;
1679
1680 if (pskb_trim(skb, snaplen))
1681 goto drop_n_acct;
1682
1683 skb_set_owner_r(skb, sk);
1684 skb->dev = NULL;
1685 skb_dst_drop(skb);
1686
1687 /* drop conntrack reference */
1688 nf_reset(skb);
1689
1690 spin_lock(&sk->sk_receive_queue.lock);
1691 po->stats.tp_packets++;
1692 skb->dropcount = atomic_read(&sk->sk_drops);
1693 __skb_queue_tail(&sk->sk_receive_queue, skb);
1694 spin_unlock(&sk->sk_receive_queue.lock);
1695 sk->sk_data_ready(sk, skb->len);
1696 return 0;
1697
1698 drop_n_acct:
1699 spin_lock(&sk->sk_receive_queue.lock);
1700 po->stats.tp_drops++;
1701 atomic_inc(&sk->sk_drops);
1702 spin_unlock(&sk->sk_receive_queue.lock);
1703
1704 drop_n_restore:
1705 if (skb_head != skb->data && skb_shared(skb)) {
1706 skb->data = skb_head;
1707 skb->len = skb_len;
1708 }
1709 drop:
1710 consume_skb(skb);
1711 return 0;
1712 }
1713
1714 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1715 struct packet_type *pt, struct net_device *orig_dev)
1716 {
1717 struct sock *sk;
1718 struct packet_sock *po;
1719 struct sockaddr_ll *sll;
1720 union {
1721 struct tpacket_hdr *h1;
1722 struct tpacket2_hdr *h2;
1723 struct tpacket3_hdr *h3;
1724 void *raw;
1725 } h;
1726 u8 *skb_head = skb->data;
1727 int skb_len = skb->len;
1728 unsigned int snaplen, res;
1729 unsigned long status = TP_STATUS_USER;
1730 unsigned short macoff, netoff, hdrlen;
1731 struct sk_buff *copy_skb = NULL;
1732 struct timeval tv;
1733 struct timespec ts;
1734 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
1735
1736 if (skb->pkt_type == PACKET_LOOPBACK)
1737 goto drop;
1738
1739 sk = pt->af_packet_priv;
1740 po = pkt_sk(sk);
1741
1742 if (!net_eq(dev_net(dev), sock_net(sk)))
1743 goto drop;
1744
1745 if (dev->header_ops) {
1746 if (sk->sk_type != SOCK_DGRAM)
1747 skb_push(skb, skb->data - skb_mac_header(skb));
1748 else if (skb->pkt_type == PACKET_OUTGOING) {
1749 /* Special case: outgoing packets have ll header at head */
1750 skb_pull(skb, skb_network_offset(skb));
1751 }
1752 }
1753
1754 if (skb->ip_summed == CHECKSUM_PARTIAL)
1755 status |= TP_STATUS_CSUMNOTREADY;
1756
1757 snaplen = skb->len;
1758
1759 res = run_filter(skb, sk, snaplen);
1760 if (!res)
1761 goto drop_n_restore;
1762 if (snaplen > res)
1763 snaplen = res;
1764
1765 if (sk->sk_type == SOCK_DGRAM) {
1766 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1767 po->tp_reserve;
1768 } else {
1769 unsigned int maclen = skb_network_offset(skb);
1770 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1771 (maclen < 16 ? 16 : maclen)) +
1772 po->tp_reserve;
1773 macoff = netoff - maclen;
1774 }
1775 if (po->tp_version <= TPACKET_V2) {
1776 if (macoff + snaplen > po->rx_ring.frame_size) {
1777 if (po->copy_thresh &&
1778 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1779 if (skb_shared(skb)) {
1780 copy_skb = skb_clone(skb, GFP_ATOMIC);
1781 } else {
1782 copy_skb = skb_get(skb);
1783 skb_head = skb->data;
1784 }
1785 if (copy_skb)
1786 skb_set_owner_r(copy_skb, sk);
1787 }
1788 snaplen = po->rx_ring.frame_size - macoff;
1789 if ((int)snaplen < 0)
1790 snaplen = 0;
1791 }
1792 }
1793 spin_lock(&sk->sk_receive_queue.lock);
1794 h.raw = packet_current_rx_frame(po, skb,
1795 TP_STATUS_KERNEL, (macoff+snaplen));
1796 if (!h.raw)
1797 goto ring_is_full;
1798 if (po->tp_version <= TPACKET_V2) {
1799 packet_increment_rx_head(po, &po->rx_ring);
1800 /*
1801 * LOSING will be reported till you read the stats,
1802 * because it's COR - Clear On Read.
1803 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1804 * at packet level.
1805 */
1806 if (po->stats.tp_drops)
1807 status |= TP_STATUS_LOSING;
1808 }
1809 po->stats.tp_packets++;
1810 if (copy_skb) {
1811 status |= TP_STATUS_COPY;
1812 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1813 }
1814 spin_unlock(&sk->sk_receive_queue.lock);
1815
1816 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1817
1818 switch (po->tp_version) {
1819 case TPACKET_V1:
1820 h.h1->tp_len = skb->len;
1821 h.h1->tp_snaplen = snaplen;
1822 h.h1->tp_mac = macoff;
1823 h.h1->tp_net = netoff;
1824 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1825 && shhwtstamps->syststamp.tv64)
1826 tv = ktime_to_timeval(shhwtstamps->syststamp);
1827 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1828 && shhwtstamps->hwtstamp.tv64)
1829 tv = ktime_to_timeval(shhwtstamps->hwtstamp);
1830 else if (skb->tstamp.tv64)
1831 tv = ktime_to_timeval(skb->tstamp);
1832 else
1833 do_gettimeofday(&tv);
1834 h.h1->tp_sec = tv.tv_sec;
1835 h.h1->tp_usec = tv.tv_usec;
1836 hdrlen = sizeof(*h.h1);
1837 break;
1838 case TPACKET_V2:
1839 h.h2->tp_len = skb->len;
1840 h.h2->tp_snaplen = snaplen;
1841 h.h2->tp_mac = macoff;
1842 h.h2->tp_net = netoff;
1843 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1844 && shhwtstamps->syststamp.tv64)
1845 ts = ktime_to_timespec(shhwtstamps->syststamp);
1846 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1847 && shhwtstamps->hwtstamp.tv64)
1848 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1849 else if (skb->tstamp.tv64)
1850 ts = ktime_to_timespec(skb->tstamp);
1851 else
1852 getnstimeofday(&ts);
1853 h.h2->tp_sec = ts.tv_sec;
1854 h.h2->tp_nsec = ts.tv_nsec;
1855 if (vlan_tx_tag_present(skb)) {
1856 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1857 status |= TP_STATUS_VLAN_VALID;
1858 } else {
1859 h.h2->tp_vlan_tci = 0;
1860 }
1861 h.h2->tp_padding = 0;
1862 hdrlen = sizeof(*h.h2);
1863 break;
1864 case TPACKET_V3:
1865 /* tp_nxt_offset,vlan are already populated above.
1866 * So DONT clear those fields here
1867 */
1868 h.h3->tp_status |= status;
1869 h.h3->tp_len = skb->len;
1870 h.h3->tp_snaplen = snaplen;
1871 h.h3->tp_mac = macoff;
1872 h.h3->tp_net = netoff;
1873 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1874 && shhwtstamps->syststamp.tv64)
1875 ts = ktime_to_timespec(shhwtstamps->syststamp);
1876 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1877 && shhwtstamps->hwtstamp.tv64)
1878 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1879 else if (skb->tstamp.tv64)
1880 ts = ktime_to_timespec(skb->tstamp);
1881 else
1882 getnstimeofday(&ts);
1883 h.h3->tp_sec = ts.tv_sec;
1884 h.h3->tp_nsec = ts.tv_nsec;
1885 hdrlen = sizeof(*h.h3);
1886 break;
1887 default:
1888 BUG();
1889 }
1890
1891 sll = h.raw + TPACKET_ALIGN(hdrlen);
1892 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1893 sll->sll_family = AF_PACKET;
1894 sll->sll_hatype = dev->type;
1895 sll->sll_protocol = skb->protocol;
1896 sll->sll_pkttype = skb->pkt_type;
1897 if (unlikely(po->origdev))
1898 sll->sll_ifindex = orig_dev->ifindex;
1899 else
1900 sll->sll_ifindex = dev->ifindex;
1901
1902 smp_mb();
1903 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1904 {
1905 u8 *start, *end;
1906
1907 if (po->tp_version <= TPACKET_V2) {
1908 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1909 + macoff + snaplen);
1910 for (start = h.raw; start < end; start += PAGE_SIZE)
1911 flush_dcache_page(pgv_to_page(start));
1912 }
1913 smp_wmb();
1914 }
1915 #endif
1916 if (po->tp_version <= TPACKET_V2)
1917 __packet_set_status(po, h.raw, status);
1918 else
1919 prb_clear_blk_fill_status(&po->rx_ring);
1920
1921 sk->sk_data_ready(sk, 0);
1922
1923 drop_n_restore:
1924 if (skb_head != skb->data && skb_shared(skb)) {
1925 skb->data = skb_head;
1926 skb->len = skb_len;
1927 }
1928 drop:
1929 kfree_skb(skb);
1930 return 0;
1931
1932 ring_is_full:
1933 po->stats.tp_drops++;
1934 spin_unlock(&sk->sk_receive_queue.lock);
1935
1936 sk->sk_data_ready(sk, 0);
1937 kfree_skb(copy_skb);
1938 goto drop_n_restore;
1939 }
1940
1941 static void tpacket_destruct_skb(struct sk_buff *skb)
1942 {
1943 struct packet_sock *po = pkt_sk(skb->sk);
1944 void *ph;
1945
1946 if (likely(po->tx_ring.pg_vec)) {
1947 ph = skb_shinfo(skb)->destructor_arg;
1948 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1949 atomic_dec(&po->tx_ring.pending);
1950 __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
1951 }
1952
1953 sock_wfree(skb);
1954 }
1955
1956 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1957 void *frame, struct net_device *dev, int size_max,
1958 __be16 proto, unsigned char *addr, int hlen)
1959 {
1960 union {
1961 struct tpacket_hdr *h1;
1962 struct tpacket2_hdr *h2;
1963 void *raw;
1964 } ph;
1965 int to_write, offset, len, tp_len, nr_frags, len_max;
1966 struct socket *sock = po->sk.sk_socket;
1967 struct page *page;
1968 void *data;
1969 int err;
1970
1971 ph.raw = frame;
1972
1973 skb->protocol = proto;
1974 skb->dev = dev;
1975 skb->priority = po->sk.sk_priority;
1976 skb->mark = po->sk.sk_mark;
1977 skb_shinfo(skb)->destructor_arg = ph.raw;
1978
1979 switch (po->tp_version) {
1980 case TPACKET_V2:
1981 tp_len = ph.h2->tp_len;
1982 break;
1983 default:
1984 tp_len = ph.h1->tp_len;
1985 break;
1986 }
1987 if (unlikely(tp_len > size_max)) {
1988 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1989 return -EMSGSIZE;
1990 }
1991
1992 skb_reserve(skb, hlen);
1993 skb_reset_network_header(skb);
1994
1995 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1996 to_write = tp_len;
1997
1998 if (sock->type == SOCK_DGRAM) {
1999 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2000 NULL, tp_len);
2001 if (unlikely(err < 0))
2002 return -EINVAL;
2003 } else if (dev->hard_header_len) {
2004 /* net device doesn't like empty head */
2005 if (unlikely(tp_len <= dev->hard_header_len)) {
2006 pr_err("packet size is too short (%d < %d)\n",
2007 tp_len, dev->hard_header_len);
2008 return -EINVAL;
2009 }
2010
2011 skb_push(skb, dev->hard_header_len);
2012 err = skb_store_bits(skb, 0, data,
2013 dev->hard_header_len);
2014 if (unlikely(err))
2015 return err;
2016
2017 data += dev->hard_header_len;
2018 to_write -= dev->hard_header_len;
2019 }
2020
2021 err = -EFAULT;
2022 offset = offset_in_page(data);
2023 len_max = PAGE_SIZE - offset;
2024 len = ((to_write > len_max) ? len_max : to_write);
2025
2026 skb->data_len = to_write;
2027 skb->len += to_write;
2028 skb->truesize += to_write;
2029 atomic_add(to_write, &po->sk.sk_wmem_alloc);
2030
2031 while (likely(to_write)) {
2032 nr_frags = skb_shinfo(skb)->nr_frags;
2033
2034 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2035 pr_err("Packet exceed the number of skb frags(%lu)\n",
2036 MAX_SKB_FRAGS);
2037 return -EFAULT;
2038 }
2039
2040 page = pgv_to_page(data);
2041 data += len;
2042 flush_dcache_page(page);
2043 get_page(page);
2044 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2045 to_write -= len;
2046 offset = 0;
2047 len_max = PAGE_SIZE;
2048 len = ((to_write > len_max) ? len_max : to_write);
2049 }
2050
2051 return tp_len;
2052 }
2053
2054 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2055 {
2056 struct sk_buff *skb;
2057 struct net_device *dev;
2058 __be16 proto;
2059 bool need_rls_dev = false;
2060 int err, reserve = 0;
2061 void *ph;
2062 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2063 int tp_len, size_max;
2064 unsigned char *addr;
2065 int len_sum = 0;
2066 int status = 0;
2067 int hlen, tlen;
2068
2069 mutex_lock(&po->pg_vec_lock);
2070
2071 err = -EBUSY;
2072 if (saddr == NULL) {
2073 dev = po->prot_hook.dev;
2074 proto = po->num;
2075 addr = NULL;
2076 } else {
2077 err = -EINVAL;
2078 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2079 goto out;
2080 if (msg->msg_namelen < (saddr->sll_halen
2081 + offsetof(struct sockaddr_ll,
2082 sll_addr)))
2083 goto out;
2084 proto = saddr->sll_protocol;
2085 addr = saddr->sll_addr;
2086 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2087 need_rls_dev = true;
2088 }
2089
2090 err = -ENXIO;
2091 if (unlikely(dev == NULL))
2092 goto out;
2093
2094 reserve = dev->hard_header_len;
2095
2096 err = -ENETDOWN;
2097 if (unlikely(!(dev->flags & IFF_UP)))
2098 goto out_put;
2099
2100 size_max = po->tx_ring.frame_size
2101 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2102
2103 if (size_max > dev->mtu + reserve)
2104 size_max = dev->mtu + reserve;
2105
2106 do {
2107 ph = packet_current_frame(po, &po->tx_ring,
2108 TP_STATUS_SEND_REQUEST);
2109
2110 if (unlikely(ph == NULL)) {
2111 schedule();
2112 continue;
2113 }
2114
2115 status = TP_STATUS_SEND_REQUEST;
2116 hlen = LL_RESERVED_SPACE(dev);
2117 tlen = dev->needed_tailroom;
2118 skb = sock_alloc_send_skb(&po->sk,
2119 hlen + tlen + sizeof(struct sockaddr_ll),
2120 0, &err);
2121
2122 if (unlikely(skb == NULL))
2123 goto out_status;
2124
2125 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2126 addr, hlen);
2127
2128 if (unlikely(tp_len < 0)) {
2129 if (po->tp_loss) {
2130 __packet_set_status(po, ph,
2131 TP_STATUS_AVAILABLE);
2132 packet_increment_head(&po->tx_ring);
2133 kfree_skb(skb);
2134 continue;
2135 } else {
2136 status = TP_STATUS_WRONG_FORMAT;
2137 err = tp_len;
2138 goto out_status;
2139 }
2140 }
2141
2142 skb->destructor = tpacket_destruct_skb;
2143 __packet_set_status(po, ph, TP_STATUS_SENDING);
2144 atomic_inc(&po->tx_ring.pending);
2145
2146 status = TP_STATUS_SEND_REQUEST;
2147 err = dev_queue_xmit(skb);
2148 if (unlikely(err > 0)) {
2149 err = net_xmit_errno(err);
2150 if (err && __packet_get_status(po, ph) ==
2151 TP_STATUS_AVAILABLE) {
2152 /* skb was destructed already */
2153 skb = NULL;
2154 goto out_status;
2155 }
2156 /*
2157 * skb was dropped but not destructed yet;
2158 * let's treat it like congestion or err < 0
2159 */
2160 err = 0;
2161 }
2162 packet_increment_head(&po->tx_ring);
2163 len_sum += tp_len;
2164 } while (likely((ph != NULL) ||
2165 ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2166 (atomic_read(&po->tx_ring.pending))))
2167 );
2168
2169 err = len_sum;
2170 goto out_put;
2171
2172 out_status:
2173 __packet_set_status(po, ph, status);
2174 kfree_skb(skb);
2175 out_put:
2176 if (need_rls_dev)
2177 dev_put(dev);
2178 out:
2179 mutex_unlock(&po->pg_vec_lock);
2180 return err;
2181 }
2182
2183 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2184 size_t reserve, size_t len,
2185 size_t linear, int noblock,
2186 int *err)
2187 {
2188 struct sk_buff *skb;
2189
2190 /* Under a page? Don't bother with paged skb. */
2191 if (prepad + len < PAGE_SIZE || !linear)
2192 linear = len;
2193
2194 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2195 err);
2196 if (!skb)
2197 return NULL;
2198
2199 skb_reserve(skb, reserve);
2200 skb_put(skb, linear);
2201 skb->data_len = len - linear;
2202 skb->len += len - linear;
2203
2204 return skb;
2205 }
2206
2207 static int packet_snd(struct socket *sock,
2208 struct msghdr *msg, size_t len)
2209 {
2210 struct sock *sk = sock->sk;
2211 struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2212 struct sk_buff *skb;
2213 struct net_device *dev;
2214 __be16 proto;
2215 bool need_rls_dev = false;
2216 unsigned char *addr;
2217 int err, reserve = 0;
2218 struct virtio_net_hdr vnet_hdr = { 0 };
2219 int offset = 0;
2220 int vnet_hdr_len;
2221 struct packet_sock *po = pkt_sk(sk);
2222 unsigned short gso_type = 0;
2223 int hlen, tlen;
2224 int extra_len = 0;
2225
2226 /*
2227 * Get and verify the address.
2228 */
2229
2230 if (saddr == NULL) {
2231 dev = po->prot_hook.dev;
2232 proto = po->num;
2233 addr = NULL;
2234 } else {
2235 err = -EINVAL;
2236 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2237 goto out;
2238 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2239 goto out;
2240 proto = saddr->sll_protocol;
2241 addr = saddr->sll_addr;
2242 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2243 need_rls_dev = true;
2244 }
2245
2246 err = -ENXIO;
2247 if (dev == NULL)
2248 goto out_unlock;
2249 if (sock->type == SOCK_RAW)
2250 reserve = dev->hard_header_len;
2251
2252 err = -ENETDOWN;
2253 if (!(dev->flags & IFF_UP))
2254 goto out_unlock;
2255
2256 if (po->has_vnet_hdr) {
2257 vnet_hdr_len = sizeof(vnet_hdr);
2258
2259 err = -EINVAL;
2260 if (len < vnet_hdr_len)
2261 goto out_unlock;
2262
2263 len -= vnet_hdr_len;
2264
2265 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2266 vnet_hdr_len);
2267 if (err < 0)
2268 goto out_unlock;
2269
2270 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2271 (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2272 vnet_hdr.hdr_len))
2273 vnet_hdr.hdr_len = vnet_hdr.csum_start +
2274 vnet_hdr.csum_offset + 2;
2275
2276 err = -EINVAL;
2277 if (vnet_hdr.hdr_len > len)
2278 goto out_unlock;
2279
2280 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2281 switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2282 case VIRTIO_NET_HDR_GSO_TCPV4:
2283 gso_type = SKB_GSO_TCPV4;
2284 break;
2285 case VIRTIO_NET_HDR_GSO_TCPV6:
2286 gso_type = SKB_GSO_TCPV6;
2287 break;
2288 case VIRTIO_NET_HDR_GSO_UDP:
2289 gso_type = SKB_GSO_UDP;
2290 break;
2291 default:
2292 goto out_unlock;
2293 }
2294
2295 if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2296 gso_type |= SKB_GSO_TCP_ECN;
2297
2298 if (vnet_hdr.gso_size == 0)
2299 goto out_unlock;
2300
2301 }
2302 }
2303
2304 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2305 if (!netif_supports_nofcs(dev)) {
2306 err = -EPROTONOSUPPORT;
2307 goto out_unlock;
2308 }
2309 extra_len = 4; /* We're doing our own CRC */
2310 }
2311
2312 err = -EMSGSIZE;
2313 if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2314 goto out_unlock;
2315
2316 err = -ENOBUFS;
2317 hlen = LL_RESERVED_SPACE(dev);
2318 tlen = dev->needed_tailroom;
2319 skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2320 msg->msg_flags & MSG_DONTWAIT, &err);
2321 if (skb == NULL)
2322 goto out_unlock;
2323
2324 skb_set_network_header(skb, reserve);
2325
2326 err = -EINVAL;
2327 if (sock->type == SOCK_DGRAM &&
2328 (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2329 goto out_free;
2330
2331 /* Returns -EFAULT on error */
2332 err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2333 if (err)
2334 goto out_free;
2335 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2336 if (err < 0)
2337 goto out_free;
2338
2339 if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2340 /* Earlier code assumed this would be a VLAN pkt,
2341 * double-check this now that we have the actual
2342 * packet in hand.
2343 */
2344 struct ethhdr *ehdr;
2345 skb_reset_mac_header(skb);
2346 ehdr = eth_hdr(skb);
2347 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2348 err = -EMSGSIZE;
2349 goto out_free;
2350 }
2351 }
2352
2353 skb->protocol = proto;
2354 skb->dev = dev;
2355 skb->priority = sk->sk_priority;
2356 skb->mark = sk->sk_mark;
2357
2358 if (po->has_vnet_hdr) {
2359 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2360 if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2361 vnet_hdr.csum_offset)) {
2362 err = -EINVAL;
2363 goto out_free;
2364 }
2365 }
2366
2367 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2368 skb_shinfo(skb)->gso_type = gso_type;
2369
2370 /* Header must be checked, and gso_segs computed. */
2371 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2372 skb_shinfo(skb)->gso_segs = 0;
2373
2374 len += vnet_hdr_len;
2375 }
2376
2377 if (unlikely(extra_len == 4))
2378 skb->no_fcs = 1;
2379
2380 /*
2381 * Now send it
2382 */
2383
2384 err = dev_queue_xmit(skb);
2385 if (err > 0 && (err = net_xmit_errno(err)) != 0)
2386 goto out_unlock;
2387
2388 if (need_rls_dev)
2389 dev_put(dev);
2390
2391 return len;
2392
2393 out_free:
2394 kfree_skb(skb);
2395 out_unlock:
2396 if (dev && need_rls_dev)
2397 dev_put(dev);
2398 out:
2399 return err;
2400 }
2401
2402 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2403 struct msghdr *msg, size_t len)
2404 {
2405 struct sock *sk = sock->sk;
2406 struct packet_sock *po = pkt_sk(sk);
2407 if (po->tx_ring.pg_vec)
2408 return tpacket_snd(po, msg);
2409 else
2410 return packet_snd(sock, msg, len);
2411 }
2412
2413 /*
2414 * Close a PACKET socket. This is fairly simple. We immediately go
2415 * to 'closed' state and remove our protocol entry in the device list.
2416 */
2417
2418 static int packet_release(struct socket *sock)
2419 {
2420 struct sock *sk = sock->sk;
2421 struct packet_sock *po;
2422 struct net *net;
2423 union tpacket_req_u req_u;
2424
2425 if (!sk)
2426 return 0;
2427
2428 net = sock_net(sk);
2429 po = pkt_sk(sk);
2430
2431 spin_lock_bh(&net->packet.sklist_lock);
2432 sk_del_node_init_rcu(sk);
2433 sock_prot_inuse_add(net, sk->sk_prot, -1);
2434 spin_unlock_bh(&net->packet.sklist_lock);
2435
2436 spin_lock(&po->bind_lock);
2437 unregister_prot_hook(sk, false);
2438 if (po->prot_hook.dev) {
2439 dev_put(po->prot_hook.dev);
2440 po->prot_hook.dev = NULL;
2441 }
2442 spin_unlock(&po->bind_lock);
2443
2444 packet_flush_mclist(sk);
2445
2446 memset(&req_u, 0, sizeof(req_u));
2447
2448 if (po->rx_ring.pg_vec)
2449 packet_set_ring(sk, &req_u, 1, 0);
2450
2451 if (po->tx_ring.pg_vec)
2452 packet_set_ring(sk, &req_u, 1, 1);
2453
2454 fanout_release(sk);
2455
2456 synchronize_net();
2457 /*
2458 * Now the socket is dead. No more input will appear.
2459 */
2460 sock_orphan(sk);
2461 sock->sk = NULL;
2462
2463 /* Purge queues */
2464
2465 skb_queue_purge(&sk->sk_receive_queue);
2466 sk_refcnt_debug_release(sk);
2467
2468 sock_put(sk);
2469 return 0;
2470 }
2471
2472 /*
2473 * Attach a packet hook.
2474 */
2475
2476 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2477 {
2478 struct packet_sock *po = pkt_sk(sk);
2479
2480 if (po->fanout) {
2481 if (dev)
2482 dev_put(dev);
2483
2484 return -EINVAL;
2485 }
2486
2487 lock_sock(sk);
2488
2489 spin_lock(&po->bind_lock);
2490 unregister_prot_hook(sk, true);
2491 po->num = protocol;
2492 po->prot_hook.type = protocol;
2493 if (po->prot_hook.dev)
2494 dev_put(po->prot_hook.dev);
2495 po->prot_hook.dev = dev;
2496
2497 po->ifindex = dev ? dev->ifindex : 0;
2498
2499 if (protocol == 0)
2500 goto out_unlock;
2501
2502 if (!dev || (dev->flags & IFF_UP)) {
2503 register_prot_hook(sk);
2504 } else {
2505 sk->sk_err = ENETDOWN;
2506 if (!sock_flag(sk, SOCK_DEAD))
2507 sk->sk_error_report(sk);
2508 }
2509
2510 out_unlock:
2511 spin_unlock(&po->bind_lock);
2512 release_sock(sk);
2513 return 0;
2514 }
2515
2516 /*
2517 * Bind a packet socket to a device
2518 */
2519
2520 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2521 int addr_len)
2522 {
2523 struct sock *sk = sock->sk;
2524 char name[15];
2525 struct net_device *dev;
2526 int err = -ENODEV;
2527
2528 /*
2529 * Check legality
2530 */
2531
2532 if (addr_len != sizeof(struct sockaddr))
2533 return -EINVAL;
2534 strlcpy(name, uaddr->sa_data, sizeof(name));
2535
2536 dev = dev_get_by_name(sock_net(sk), name);
2537 if (dev)
2538 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2539 return err;
2540 }
2541
2542 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2543 {
2544 struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2545 struct sock *sk = sock->sk;
2546 struct net_device *dev = NULL;
2547 int err;
2548
2549
2550 /*
2551 * Check legality
2552 */
2553
2554 if (addr_len < sizeof(struct sockaddr_ll))
2555 return -EINVAL;
2556 if (sll->sll_family != AF_PACKET)
2557 return -EINVAL;
2558
2559 if (sll->sll_ifindex) {
2560 err = -ENODEV;
2561 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2562 if (dev == NULL)
2563 goto out;
2564 }
2565 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2566
2567 out:
2568 return err;
2569 }
2570
2571 static struct proto packet_proto = {
2572 .name = "PACKET",
2573 .owner = THIS_MODULE,
2574 .obj_size = sizeof(struct packet_sock),
2575 };
2576
2577 /*
2578 * Create a packet of type SOCK_PACKET.
2579 */
2580
2581 static int packet_create(struct net *net, struct socket *sock, int protocol,
2582 int kern)
2583 {
2584 struct sock *sk;
2585 struct packet_sock *po;
2586 __be16 proto = (__force __be16)protocol; /* weird, but documented */
2587 int err;
2588
2589 if (!capable(CAP_NET_RAW))
2590 return -EPERM;
2591 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2592 sock->type != SOCK_PACKET)
2593 return -ESOCKTNOSUPPORT;
2594
2595 sock->state = SS_UNCONNECTED;
2596
2597 err = -ENOBUFS;
2598 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2599 if (sk == NULL)
2600 goto out;
2601
2602 sock->ops = &packet_ops;
2603 if (sock->type == SOCK_PACKET)
2604 sock->ops = &packet_ops_spkt;
2605
2606 sock_init_data(sock, sk);
2607
2608 po = pkt_sk(sk);
2609 sk->sk_family = PF_PACKET;
2610 po->num = proto;
2611
2612 sk->sk_destruct = packet_sock_destruct;
2613 sk_refcnt_debug_inc(sk);
2614
2615 /*
2616 * Attach a protocol block
2617 */
2618
2619 spin_lock_init(&po->bind_lock);
2620 mutex_init(&po->pg_vec_lock);
2621 po->prot_hook.func = packet_rcv;
2622
2623 if (sock->type == SOCK_PACKET)
2624 po->prot_hook.func = packet_rcv_spkt;
2625
2626 po->prot_hook.af_packet_priv = sk;
2627
2628 if (proto) {
2629 po->prot_hook.type = proto;
2630 register_prot_hook(sk);
2631 }
2632
2633 spin_lock_bh(&net->packet.sklist_lock);
2634 sk_add_node_rcu(sk, &net->packet.sklist);
2635 sock_prot_inuse_add(net, &packet_proto, 1);
2636 spin_unlock_bh(&net->packet.sklist_lock);
2637
2638 return 0;
2639 out:
2640 return err;
2641 }
2642
2643 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2644 {
2645 struct sock_exterr_skb *serr;
2646 struct sk_buff *skb, *skb2;
2647 int copied, err;
2648
2649 err = -EAGAIN;
2650 skb = skb_dequeue(&sk->sk_error_queue);
2651 if (skb == NULL)
2652 goto out;
2653
2654 copied = skb->len;
2655 if (copied > len) {
2656 msg->msg_flags |= MSG_TRUNC;
2657 copied = len;
2658 }
2659 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2660 if (err)
2661 goto out_free_skb;
2662
2663 sock_recv_timestamp(msg, sk, skb);
2664
2665 serr = SKB_EXT_ERR(skb);
2666 put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2667 sizeof(serr->ee), &serr->ee);
2668
2669 msg->msg_flags |= MSG_ERRQUEUE;
2670 err = copied;
2671
2672 /* Reset and regenerate socket error */
2673 spin_lock_bh(&sk->sk_error_queue.lock);
2674 sk->sk_err = 0;
2675 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2676 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2677 spin_unlock_bh(&sk->sk_error_queue.lock);
2678 sk->sk_error_report(sk);
2679 } else
2680 spin_unlock_bh(&sk->sk_error_queue.lock);
2681
2682 out_free_skb:
2683 kfree_skb(skb);
2684 out:
2685 return err;
2686 }
2687
2688 /*
2689 * Pull a packet from our receive queue and hand it to the user.
2690 * If necessary we block.
2691 */
2692
2693 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2694 struct msghdr *msg, size_t len, int flags)
2695 {
2696 struct sock *sk = sock->sk;
2697 struct sk_buff *skb;
2698 int copied, err;
2699 struct sockaddr_ll *sll;
2700 int vnet_hdr_len = 0;
2701
2702 err = -EINVAL;
2703 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2704 goto out;
2705
2706 #if 0
2707 /* What error should we return now? EUNATTACH? */
2708 if (pkt_sk(sk)->ifindex < 0)
2709 return -ENODEV;
2710 #endif
2711
2712 if (flags & MSG_ERRQUEUE) {
2713 err = packet_recv_error(sk, msg, len);
2714 goto out;
2715 }
2716
2717 /*
2718 * Call the generic datagram receiver. This handles all sorts
2719 * of horrible races and re-entrancy so we can forget about it
2720 * in the protocol layers.
2721 *
2722 * Now it will return ENETDOWN, if device have just gone down,
2723 * but then it will block.
2724 */
2725
2726 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2727
2728 /*
2729 * An error occurred so return it. Because skb_recv_datagram()
2730 * handles the blocking we don't see and worry about blocking
2731 * retries.
2732 */
2733
2734 if (skb == NULL)
2735 goto out;
2736
2737 if (pkt_sk(sk)->has_vnet_hdr) {
2738 struct virtio_net_hdr vnet_hdr = { 0 };
2739
2740 err = -EINVAL;
2741 vnet_hdr_len = sizeof(vnet_hdr);
2742 if (len < vnet_hdr_len)
2743 goto out_free;
2744
2745 len -= vnet_hdr_len;
2746
2747 if (skb_is_gso(skb)) {
2748 struct skb_shared_info *sinfo = skb_shinfo(skb);
2749
2750 /* This is a hint as to how much should be linear. */
2751 vnet_hdr.hdr_len = skb_headlen(skb);
2752 vnet_hdr.gso_size = sinfo->gso_size;
2753 if (sinfo->gso_type & SKB_GSO_TCPV4)
2754 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2755 else if (sinfo->gso_type & SKB_GSO_TCPV6)
2756 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2757 else if (sinfo->gso_type & SKB_GSO_UDP)
2758 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2759 else if (sinfo->gso_type & SKB_GSO_FCOE)
2760 goto out_free;
2761 else
2762 BUG();
2763 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2764 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2765 } else
2766 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2767
2768 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2769 vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2770 vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2771 vnet_hdr.csum_offset = skb->csum_offset;
2772 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2773 vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2774 } /* else everything is zero */
2775
2776 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2777 vnet_hdr_len);
2778 if (err < 0)
2779 goto out_free;
2780 }
2781
2782 /*
2783 * If the address length field is there to be filled in, we fill
2784 * it in now.
2785 */
2786
2787 sll = &PACKET_SKB_CB(skb)->sa.ll;
2788 if (sock->type == SOCK_PACKET)
2789 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2790 else
2791 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
2792
2793 /*
2794 * You lose any data beyond the buffer you gave. If it worries a
2795 * user program they can ask the device for its MTU anyway.
2796 */
2797
2798 copied = skb->len;
2799 if (copied > len) {
2800 copied = len;
2801 msg->msg_flags |= MSG_TRUNC;
2802 }
2803
2804 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2805 if (err)
2806 goto out_free;
2807
2808 sock_recv_ts_and_drops(msg, sk, skb);
2809
2810 if (msg->msg_name)
2811 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2812 msg->msg_namelen);
2813
2814 if (pkt_sk(sk)->auxdata) {
2815 struct tpacket_auxdata aux;
2816
2817 aux.tp_status = TP_STATUS_USER;
2818 if (skb->ip_summed == CHECKSUM_PARTIAL)
2819 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2820 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2821 aux.tp_snaplen = skb->len;
2822 aux.tp_mac = 0;
2823 aux.tp_net = skb_network_offset(skb);
2824 if (vlan_tx_tag_present(skb)) {
2825 aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2826 aux.tp_status |= TP_STATUS_VLAN_VALID;
2827 } else {
2828 aux.tp_vlan_tci = 0;
2829 }
2830 aux.tp_padding = 0;
2831 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2832 }
2833
2834 /*
2835 * Free or return the buffer as appropriate. Again this
2836 * hides all the races and re-entrancy issues from us.
2837 */
2838 err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2839
2840 out_free:
2841 skb_free_datagram(sk, skb);
2842 out:
2843 return err;
2844 }
2845
2846 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2847 int *uaddr_len, int peer)
2848 {
2849 struct net_device *dev;
2850 struct sock *sk = sock->sk;
2851
2852 if (peer)
2853 return -EOPNOTSUPP;
2854
2855 uaddr->sa_family = AF_PACKET;
2856 rcu_read_lock();
2857 dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2858 if (dev)
2859 strncpy(uaddr->sa_data, dev->name, 14);
2860 else
2861 memset(uaddr->sa_data, 0, 14);
2862 rcu_read_unlock();
2863 *uaddr_len = sizeof(*uaddr);
2864
2865 return 0;
2866 }
2867
2868 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2869 int *uaddr_len, int peer)
2870 {
2871 struct net_device *dev;
2872 struct sock *sk = sock->sk;
2873 struct packet_sock *po = pkt_sk(sk);
2874 DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2875
2876 if (peer)
2877 return -EOPNOTSUPP;
2878
2879 sll->sll_family = AF_PACKET;
2880 sll->sll_ifindex = po->ifindex;
2881 sll->sll_protocol = po->num;
2882 sll->sll_pkttype = 0;
2883 rcu_read_lock();
2884 dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2885 if (dev) {
2886 sll->sll_hatype = dev->type;
2887 sll->sll_halen = dev->addr_len;
2888 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2889 } else {
2890 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
2891 sll->sll_halen = 0;
2892 }
2893 rcu_read_unlock();
2894 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2895
2896 return 0;
2897 }
2898
2899 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2900 int what)
2901 {
2902 switch (i->type) {
2903 case PACKET_MR_MULTICAST:
2904 if (i->alen != dev->addr_len)
2905 return -EINVAL;
2906 if (what > 0)
2907 return dev_mc_add(dev, i->addr);
2908 else
2909 return dev_mc_del(dev, i->addr);
2910 break;
2911 case PACKET_MR_PROMISC:
2912 return dev_set_promiscuity(dev, what);
2913 break;
2914 case PACKET_MR_ALLMULTI:
2915 return dev_set_allmulti(dev, what);
2916 break;
2917 case PACKET_MR_UNICAST:
2918 if (i->alen != dev->addr_len)
2919 return -EINVAL;
2920 if (what > 0)
2921 return dev_uc_add(dev, i->addr);
2922 else
2923 return dev_uc_del(dev, i->addr);
2924 break;
2925 default:
2926 break;
2927 }
2928 return 0;
2929 }
2930
2931 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2932 {
2933 for ( ; i; i = i->next) {
2934 if (i->ifindex == dev->ifindex)
2935 packet_dev_mc(dev, i, what);
2936 }
2937 }
2938
2939 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2940 {
2941 struct packet_sock *po = pkt_sk(sk);
2942 struct packet_mclist *ml, *i;
2943 struct net_device *dev;
2944 int err;
2945
2946 rtnl_lock();
2947
2948 err = -ENODEV;
2949 dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2950 if (!dev)
2951 goto done;
2952
2953 err = -EINVAL;
2954 if (mreq->mr_alen > dev->addr_len)
2955 goto done;
2956
2957 err = -ENOBUFS;
2958 i = kmalloc(sizeof(*i), GFP_KERNEL);
2959 if (i == NULL)
2960 goto done;
2961
2962 err = 0;
2963 for (ml = po->mclist; ml; ml = ml->next) {
2964 if (ml->ifindex == mreq->mr_ifindex &&
2965 ml->type == mreq->mr_type &&
2966 ml->alen == mreq->mr_alen &&
2967 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2968 ml->count++;
2969 /* Free the new element ... */
2970 kfree(i);
2971 goto done;
2972 }
2973 }
2974
2975 i->type = mreq->mr_type;
2976 i->ifindex = mreq->mr_ifindex;
2977 i->alen = mreq->mr_alen;
2978 memcpy(i->addr, mreq->mr_address, i->alen);
2979 i->count = 1;
2980 i->next = po->mclist;
2981 po->mclist = i;
2982 err = packet_dev_mc(dev, i, 1);
2983 if (err) {
2984 po->mclist = i->next;
2985 kfree(i);
2986 }
2987
2988 done:
2989 rtnl_unlock();
2990 return err;
2991 }
2992
2993 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2994 {
2995 struct packet_mclist *ml, **mlp;
2996
2997 rtnl_lock();
2998
2999 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3000 if (ml->ifindex == mreq->mr_ifindex &&
3001 ml->type == mreq->mr_type &&
3002 ml->alen == mreq->mr_alen &&
3003 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3004 if (--ml->count == 0) {
3005 struct net_device *dev;
3006 *mlp = ml->next;
3007 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3008 if (dev)
3009 packet_dev_mc(dev, ml, -1);
3010 kfree(ml);
3011 }
3012 rtnl_unlock();
3013 return 0;
3014 }
3015 }
3016 rtnl_unlock();
3017 return -EADDRNOTAVAIL;
3018 }
3019
3020 static void packet_flush_mclist(struct sock *sk)
3021 {
3022 struct packet_sock *po = pkt_sk(sk);
3023 struct packet_mclist *ml;
3024
3025 if (!po->mclist)
3026 return;
3027
3028 rtnl_lock();
3029 while ((ml = po->mclist) != NULL) {
3030 struct net_device *dev;
3031
3032 po->mclist = ml->next;
3033 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3034 if (dev != NULL)
3035 packet_dev_mc(dev, ml, -1);
3036 kfree(ml);
3037 }
3038 rtnl_unlock();
3039 }
3040
3041 static int
3042 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3043 {
3044 struct sock *sk = sock->sk;
3045 struct packet_sock *po = pkt_sk(sk);
3046 int ret;
3047
3048 if (level != SOL_PACKET)
3049 return -ENOPROTOOPT;
3050
3051 switch (optname) {
3052 case PACKET_ADD_MEMBERSHIP:
3053 case PACKET_DROP_MEMBERSHIP:
3054 {
3055 struct packet_mreq_max mreq;
3056 int len = optlen;
3057 memset(&mreq, 0, sizeof(mreq));
3058 if (len < sizeof(struct packet_mreq))
3059 return -EINVAL;
3060 if (len > sizeof(mreq))
3061 len = sizeof(mreq);
3062 if (copy_from_user(&mreq, optval, len))
3063 return -EFAULT;
3064 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3065 return -EINVAL;
3066 if (optname == PACKET_ADD_MEMBERSHIP)
3067 ret = packet_mc_add(sk, &mreq);
3068 else
3069 ret = packet_mc_drop(sk, &mreq);
3070 return ret;
3071 }
3072
3073 case PACKET_RX_RING:
3074 case PACKET_TX_RING:
3075 {
3076 union tpacket_req_u req_u;
3077 int len;
3078
3079 switch (po->tp_version) {
3080 case TPACKET_V1:
3081 case TPACKET_V2:
3082 len = sizeof(req_u.req);
3083 break;
3084 case TPACKET_V3:
3085 default:
3086 len = sizeof(req_u.req3);
3087 break;
3088 }
3089 if (optlen < len)
3090 return -EINVAL;
3091 if (pkt_sk(sk)->has_vnet_hdr)
3092 return -EINVAL;
3093 if (copy_from_user(&req_u.req, optval, len))
3094 return -EFAULT;
3095 return packet_set_ring(sk, &req_u, 0,
3096 optname == PACKET_TX_RING);
3097 }
3098 case PACKET_COPY_THRESH:
3099 {
3100 int val;
3101
3102 if (optlen != sizeof(val))
3103 return -EINVAL;
3104 if (copy_from_user(&val, optval, sizeof(val)))
3105 return -EFAULT;
3106
3107 pkt_sk(sk)->copy_thresh = val;
3108 return 0;
3109 }
3110 case PACKET_VERSION:
3111 {
3112 int val;
3113
3114 if (optlen != sizeof(val))
3115 return -EINVAL;
3116 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3117 return -EBUSY;
3118 if (copy_from_user(&val, optval, sizeof(val)))
3119 return -EFAULT;
3120 switch (val) {
3121 case TPACKET_V1:
3122 case TPACKET_V2:
3123 case TPACKET_V3:
3124 po->tp_version = val;
3125 return 0;
3126 default:
3127 return -EINVAL;
3128 }
3129 }
3130 case PACKET_RESERVE:
3131 {
3132 unsigned int val;
3133
3134 if (optlen != sizeof(val))
3135 return -EINVAL;
3136 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3137 return -EBUSY;
3138 if (copy_from_user(&val, optval, sizeof(val)))
3139 return -EFAULT;
3140 po->tp_reserve = val;
3141 return 0;
3142 }
3143 case PACKET_LOSS:
3144 {
3145 unsigned int val;
3146
3147 if (optlen != sizeof(val))
3148 return -EINVAL;
3149 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3150 return -EBUSY;
3151 if (copy_from_user(&val, optval, sizeof(val)))
3152 return -EFAULT;
3153 po->tp_loss = !!val;
3154 return 0;
3155 }
3156 case PACKET_AUXDATA:
3157 {
3158 int val;
3159
3160 if (optlen < sizeof(val))
3161 return -EINVAL;
3162 if (copy_from_user(&val, optval, sizeof(val)))
3163 return -EFAULT;
3164
3165 po->auxdata = !!val;
3166 return 0;
3167 }
3168 case PACKET_ORIGDEV:
3169 {
3170 int val;
3171
3172 if (optlen < sizeof(val))
3173 return -EINVAL;
3174 if (copy_from_user(&val, optval, sizeof(val)))
3175 return -EFAULT;
3176
3177 po->origdev = !!val;
3178 return 0;
3179 }
3180 case PACKET_VNET_HDR:
3181 {
3182 int val;
3183
3184 if (sock->type != SOCK_RAW)
3185 return -EINVAL;
3186 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3187 return -EBUSY;
3188 if (optlen < sizeof(val))
3189 return -EINVAL;
3190 if (copy_from_user(&val, optval, sizeof(val)))
3191 return -EFAULT;
3192
3193 po->has_vnet_hdr = !!val;
3194 return 0;
3195 }
3196 case PACKET_TIMESTAMP:
3197 {
3198 int val;
3199
3200 if (optlen != sizeof(val))
3201 return -EINVAL;
3202 if (copy_from_user(&val, optval, sizeof(val)))
3203 return -EFAULT;
3204
3205 po->tp_tstamp = val;
3206 return 0;
3207 }
3208 case PACKET_FANOUT:
3209 {
3210 int val;
3211
3212 if (optlen != sizeof(val))
3213 return -EINVAL;
3214 if (copy_from_user(&val, optval, sizeof(val)))
3215 return -EFAULT;
3216
3217 return fanout_add(sk, val & 0xffff, val >> 16);
3218 }
3219 default:
3220 return -ENOPROTOOPT;
3221 }
3222 }
3223
3224 static int packet_getsockopt(struct socket *sock, int level, int optname,
3225 char __user *optval, int __user *optlen)
3226 {
3227 int len;
3228 int val, lv = sizeof(val);
3229 struct sock *sk = sock->sk;
3230 struct packet_sock *po = pkt_sk(sk);
3231 void *data = &val;
3232 struct tpacket_stats st;
3233 union tpacket_stats_u st_u;
3234
3235 if (level != SOL_PACKET)
3236 return -ENOPROTOOPT;
3237
3238 if (get_user(len, optlen))
3239 return -EFAULT;
3240
3241 if (len < 0)
3242 return -EINVAL;
3243
3244 switch (optname) {
3245 case PACKET_STATISTICS:
3246 spin_lock_bh(&sk->sk_receive_queue.lock);
3247 if (po->tp_version == TPACKET_V3) {
3248 lv = sizeof(struct tpacket_stats_v3);
3249 memcpy(&st_u.stats3, &po->stats,
3250 sizeof(struct tpacket_stats));
3251 st_u.stats3.tp_freeze_q_cnt =
3252 po->stats_u.stats3.tp_freeze_q_cnt;
3253 st_u.stats3.tp_packets += po->stats.tp_drops;
3254 data = &st_u.stats3;
3255 } else {
3256 lv = sizeof(struct tpacket_stats);
3257 st = po->stats;
3258 st.tp_packets += st.tp_drops;
3259 data = &st;
3260 }
3261 memset(&po->stats, 0, sizeof(st));
3262 spin_unlock_bh(&sk->sk_receive_queue.lock);
3263 break;
3264 case PACKET_AUXDATA:
3265 val = po->auxdata;
3266 break;
3267 case PACKET_ORIGDEV:
3268 val = po->origdev;
3269 break;
3270 case PACKET_VNET_HDR:
3271 val = po->has_vnet_hdr;
3272 break;
3273 case PACKET_VERSION:
3274 val = po->tp_version;
3275 break;
3276 case PACKET_HDRLEN:
3277 if (len > sizeof(int))
3278 len = sizeof(int);
3279 if (copy_from_user(&val, optval, len))
3280 return -EFAULT;
3281 switch (val) {
3282 case TPACKET_V1:
3283 val = sizeof(struct tpacket_hdr);
3284 break;
3285 case TPACKET_V2:
3286 val = sizeof(struct tpacket2_hdr);
3287 break;
3288 case TPACKET_V3:
3289 val = sizeof(struct tpacket3_hdr);
3290 break;
3291 default:
3292 return -EINVAL;
3293 }
3294 break;
3295 case PACKET_RESERVE:
3296 val = po->tp_reserve;
3297 break;
3298 case PACKET_LOSS:
3299 val = po->tp_loss;
3300 break;
3301 case PACKET_TIMESTAMP:
3302 val = po->tp_tstamp;
3303 break;
3304 case PACKET_FANOUT:
3305 val = (po->fanout ?
3306 ((u32)po->fanout->id |
3307 ((u32)po->fanout->type << 16)) :
3308 0);
3309 break;
3310 default:
3311 return -ENOPROTOOPT;
3312 }
3313
3314 if (len > lv)
3315 len = lv;
3316 if (put_user(len, optlen))
3317 return -EFAULT;
3318 if (copy_to_user(optval, data, len))
3319 return -EFAULT;
3320 return 0;
3321 }
3322
3323
3324 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3325 {
3326 struct sock *sk;
3327 struct hlist_node *node;
3328 struct net_device *dev = data;
3329 struct net *net = dev_net(dev);
3330
3331 rcu_read_lock();
3332 sk_for_each_rcu(sk, node, &net->packet.sklist) {
3333 struct packet_sock *po = pkt_sk(sk);
3334
3335 switch (msg) {
3336 case NETDEV_UNREGISTER:
3337 if (po->mclist)
3338 packet_dev_mclist(dev, po->mclist, -1);
3339 /* fallthrough */
3340
3341 case NETDEV_DOWN:
3342 if (dev->ifindex == po->ifindex) {
3343 spin_lock(&po->bind_lock);
3344 if (po->running) {
3345 __unregister_prot_hook(sk, false);
3346 sk->sk_err = ENETDOWN;
3347 if (!sock_flag(sk, SOCK_DEAD))
3348 sk->sk_error_report(sk);
3349 }
3350 if (msg == NETDEV_UNREGISTER) {
3351 po->ifindex = -1;
3352 if (po->prot_hook.dev)
3353 dev_put(po->prot_hook.dev);
3354 po->prot_hook.dev = NULL;
3355 }
3356 spin_unlock(&po->bind_lock);
3357 }
3358 break;
3359 case NETDEV_UP:
3360 if (dev->ifindex == po->ifindex) {
3361 spin_lock(&po->bind_lock);
3362 if (po->num)
3363 register_prot_hook(sk);
3364 spin_unlock(&po->bind_lock);
3365 }
3366 break;
3367 }
3368 }
3369 rcu_read_unlock();
3370 return NOTIFY_DONE;
3371 }
3372
3373
3374 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3375 unsigned long arg)
3376 {
3377 struct sock *sk = sock->sk;
3378
3379 switch (cmd) {
3380 case SIOCOUTQ:
3381 {
3382 int amount = sk_wmem_alloc_get(sk);
3383
3384 return put_user(amount, (int __user *)arg);
3385 }
3386 case SIOCINQ:
3387 {
3388 struct sk_buff *skb;
3389 int amount = 0;
3390
3391 spin_lock_bh(&sk->sk_receive_queue.lock);
3392 skb = skb_peek(&sk->sk_receive_queue);
3393 if (skb)
3394 amount = skb->len;
3395 spin_unlock_bh(&sk->sk_receive_queue.lock);
3396 return put_user(amount, (int __user *)arg);
3397 }
3398 case SIOCGSTAMP:
3399 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3400 case SIOCGSTAMPNS:
3401 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3402
3403 #ifdef CONFIG_INET
3404 case SIOCADDRT:
3405 case SIOCDELRT:
3406 case SIOCDARP:
3407 case SIOCGARP:
3408 case SIOCSARP:
3409 case SIOCGIFADDR:
3410 case SIOCSIFADDR:
3411 case SIOCGIFBRDADDR:
3412 case SIOCSIFBRDADDR:
3413 case SIOCGIFNETMASK:
3414 case SIOCSIFNETMASK:
3415 case SIOCGIFDSTADDR:
3416 case SIOCSIFDSTADDR:
3417 case SIOCSIFFLAGS:
3418 return inet_dgram_ops.ioctl(sock, cmd, arg);
3419 #endif
3420
3421 default:
3422 return -ENOIOCTLCMD;
3423 }
3424 return 0;
3425 }
3426
3427 static unsigned int packet_poll(struct file *file, struct socket *sock,
3428 poll_table *wait)
3429 {
3430 struct sock *sk = sock->sk;
3431 struct packet_sock *po = pkt_sk(sk);
3432 unsigned int mask = datagram_poll(file, sock, wait);
3433
3434 spin_lock_bh(&sk->sk_receive_queue.lock);
3435 if (po->rx_ring.pg_vec) {
3436 if (!packet_previous_rx_frame(po, &po->rx_ring,
3437 TP_STATUS_KERNEL))
3438 mask |= POLLIN | POLLRDNORM;
3439 }
3440 spin_unlock_bh(&sk->sk_receive_queue.lock);
3441 spin_lock_bh(&sk->sk_write_queue.lock);
3442 if (po->tx_ring.pg_vec) {
3443 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3444 mask |= POLLOUT | POLLWRNORM;
3445 }
3446 spin_unlock_bh(&sk->sk_write_queue.lock);
3447 return mask;
3448 }
3449
3450
3451 /* Dirty? Well, I still did not learn better way to account
3452 * for user mmaps.
3453 */
3454
3455 static void packet_mm_open(struct vm_area_struct *vma)
3456 {
3457 struct file *file = vma->vm_file;
3458 struct socket *sock = file->private_data;
3459 struct sock *sk = sock->sk;
3460
3461 if (sk)
3462 atomic_inc(&pkt_sk(sk)->mapped);
3463 }
3464
3465 static void packet_mm_close(struct vm_area_struct *vma)
3466 {
3467 struct file *file = vma->vm_file;
3468 struct socket *sock = file->private_data;
3469 struct sock *sk = sock->sk;
3470
3471 if (sk)
3472 atomic_dec(&pkt_sk(sk)->mapped);
3473 }
3474
3475 static const struct vm_operations_struct packet_mmap_ops = {
3476 .open = packet_mm_open,
3477 .close = packet_mm_close,
3478 };
3479
3480 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3481 unsigned int len)
3482 {
3483 int i;
3484
3485 for (i = 0; i < len; i++) {
3486 if (likely(pg_vec[i].buffer)) {
3487 if (is_vmalloc_addr(pg_vec[i].buffer))
3488 vfree(pg_vec[i].buffer);
3489 else
3490 free_pages((unsigned long)pg_vec[i].buffer,
3491 order);
3492 pg_vec[i].buffer = NULL;
3493 }
3494 }
3495 kfree(pg_vec);
3496 }
3497
3498 static char *alloc_one_pg_vec_page(unsigned long order)
3499 {
3500 char *buffer = NULL;
3501 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3502 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3503
3504 buffer = (char *) __get_free_pages(gfp_flags, order);
3505
3506 if (buffer)
3507 return buffer;
3508
3509 /*
3510 * __get_free_pages failed, fall back to vmalloc
3511 */
3512 buffer = vzalloc((1 << order) * PAGE_SIZE);
3513
3514 if (buffer)
3515 return buffer;
3516
3517 /*
3518 * vmalloc failed, lets dig into swap here
3519 */
3520 gfp_flags &= ~__GFP_NORETRY;
3521 buffer = (char *)__get_free_pages(gfp_flags, order);
3522 if (buffer)
3523 return buffer;
3524
3525 /*
3526 * complete and utter failure
3527 */
3528 return NULL;
3529 }
3530
3531 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3532 {
3533 unsigned int block_nr = req->tp_block_nr;
3534 struct pgv *pg_vec;
3535 int i;
3536
3537 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3538 if (unlikely(!pg_vec))
3539 goto out;
3540
3541 for (i = 0; i < block_nr; i++) {
3542 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3543 if (unlikely(!pg_vec[i].buffer))
3544 goto out_free_pgvec;
3545 }
3546
3547 out:
3548 return pg_vec;
3549
3550 out_free_pgvec:
3551 free_pg_vec(pg_vec, order, block_nr);
3552 pg_vec = NULL;
3553 goto out;
3554 }
3555
3556 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3557 int closing, int tx_ring)
3558 {
3559 struct pgv *pg_vec = NULL;
3560 struct packet_sock *po = pkt_sk(sk);
3561 int was_running, order = 0;
3562 struct packet_ring_buffer *rb;
3563 struct sk_buff_head *rb_queue;
3564 __be16 num;
3565 int err = -EINVAL;
3566 /* Added to avoid minimal code churn */
3567 struct tpacket_req *req = &req_u->req;
3568
3569 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3570 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3571 WARN(1, "Tx-ring is not supported.\n");
3572 goto out;
3573 }
3574
3575 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3576 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3577
3578 err = -EBUSY;
3579 if (!closing) {
3580 if (atomic_read(&po->mapped))
3581 goto out;
3582 if (atomic_read(&rb->pending))
3583 goto out;
3584 }
3585
3586 if (req->tp_block_nr) {
3587 /* Sanity tests and some calculations */
3588 err = -EBUSY;
3589 if (unlikely(rb->pg_vec))
3590 goto out;
3591
3592 switch (po->tp_version) {
3593 case TPACKET_V1:
3594 po->tp_hdrlen = TPACKET_HDRLEN;
3595 break;
3596 case TPACKET_V2:
3597 po->tp_hdrlen = TPACKET2_HDRLEN;
3598 break;
3599 case TPACKET_V3:
3600 po->tp_hdrlen = TPACKET3_HDRLEN;
3601 break;
3602 }
3603
3604 err = -EINVAL;
3605 if (unlikely((int)req->tp_block_size <= 0))
3606 goto out;
3607 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3608 goto out;
3609 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3610 po->tp_reserve))
3611 goto out;
3612 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3613 goto out;
3614
3615 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3616 if (unlikely(rb->frames_per_block <= 0))
3617 goto out;
3618 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3619 req->tp_frame_nr))
3620 goto out;
3621
3622 err = -ENOMEM;
3623 order = get_order(req->tp_block_size);
3624 pg_vec = alloc_pg_vec(req, order);
3625 if (unlikely(!pg_vec))
3626 goto out;
3627 switch (po->tp_version) {
3628 case TPACKET_V3:
3629 /* Transmit path is not supported. We checked
3630 * it above but just being paranoid
3631 */
3632 if (!tx_ring)
3633 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3634 break;
3635 default:
3636 break;
3637 }
3638 }
3639 /* Done */
3640 else {
3641 err = -EINVAL;
3642 if (unlikely(req->tp_frame_nr))
3643 goto out;
3644 }
3645
3646 lock_sock(sk);
3647
3648 /* Detach socket from network */
3649 spin_lock(&po->bind_lock);
3650 was_running = po->running;
3651 num = po->num;
3652 if (was_running) {
3653 po->num = 0;
3654 __unregister_prot_hook(sk, false);
3655 }
3656 spin_unlock(&po->bind_lock);
3657
3658 synchronize_net();
3659
3660 err = -EBUSY;
3661 mutex_lock(&po->pg_vec_lock);
3662 if (closing || atomic_read(&po->mapped) == 0) {
3663 err = 0;
3664 spin_lock_bh(&rb_queue->lock);
3665 swap(rb->pg_vec, pg_vec);
3666 rb->frame_max = (req->tp_frame_nr - 1);
3667 rb->head = 0;
3668 rb->frame_size = req->tp_frame_size;
3669 spin_unlock_bh(&rb_queue->lock);
3670
3671 swap(rb->pg_vec_order, order);
3672 swap(rb->pg_vec_len, req->tp_block_nr);
3673
3674 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3675 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3676 tpacket_rcv : packet_rcv;
3677 skb_queue_purge(rb_queue);
3678 if (atomic_read(&po->mapped))
3679 pr_err("packet_mmap: vma is busy: %d\n",
3680 atomic_read(&po->mapped));
3681 }
3682 mutex_unlock(&po->pg_vec_lock);
3683
3684 spin_lock(&po->bind_lock);
3685 if (was_running) {
3686 po->num = num;
3687 register_prot_hook(sk);
3688 }
3689 spin_unlock(&po->bind_lock);
3690 if (closing && (po->tp_version > TPACKET_V2)) {
3691 /* Because we don't support block-based V3 on tx-ring */
3692 if (!tx_ring)
3693 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3694 }
3695 release_sock(sk);
3696
3697 if (pg_vec)
3698 free_pg_vec(pg_vec, order, req->tp_block_nr);
3699 out:
3700 return err;
3701 }
3702
3703 static int packet_mmap(struct file *file, struct socket *sock,
3704 struct vm_area_struct *vma)
3705 {
3706 struct sock *sk = sock->sk;
3707 struct packet_sock *po = pkt_sk(sk);
3708 unsigned long size, expected_size;
3709 struct packet_ring_buffer *rb;
3710 unsigned long start;
3711 int err = -EINVAL;
3712 int i;
3713
3714 if (vma->vm_pgoff)
3715 return -EINVAL;
3716
3717 mutex_lock(&po->pg_vec_lock);
3718
3719 expected_size = 0;
3720 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3721 if (rb->pg_vec) {
3722 expected_size += rb->pg_vec_len
3723 * rb->pg_vec_pages
3724 * PAGE_SIZE;
3725 }
3726 }
3727
3728 if (expected_size == 0)
3729 goto out;
3730
3731 size = vma->vm_end - vma->vm_start;
3732 if (size != expected_size)
3733 goto out;
3734
3735 start = vma->vm_start;
3736 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3737 if (rb->pg_vec == NULL)
3738 continue;
3739
3740 for (i = 0; i < rb->pg_vec_len; i++) {
3741 struct page *page;
3742 void *kaddr = rb->pg_vec[i].buffer;
3743 int pg_num;
3744
3745 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3746 page = pgv_to_page(kaddr);
3747 err = vm_insert_page(vma, start, page);
3748 if (unlikely(err))
3749 goto out;
3750 start += PAGE_SIZE;
3751 kaddr += PAGE_SIZE;
3752 }
3753 }
3754 }
3755
3756 atomic_inc(&po->mapped);
3757 vma->vm_ops = &packet_mmap_ops;
3758 err = 0;
3759
3760 out:
3761 mutex_unlock(&po->pg_vec_lock);
3762 return err;
3763 }
3764
3765 static const struct proto_ops packet_ops_spkt = {
3766 .family = PF_PACKET,
3767 .owner = THIS_MODULE,
3768 .release = packet_release,
3769 .bind = packet_bind_spkt,
3770 .connect = sock_no_connect,
3771 .socketpair = sock_no_socketpair,
3772 .accept = sock_no_accept,
3773 .getname = packet_getname_spkt,
3774 .poll = datagram_poll,
3775 .ioctl = packet_ioctl,
3776 .listen = sock_no_listen,
3777 .shutdown = sock_no_shutdown,
3778 .setsockopt = sock_no_setsockopt,
3779 .getsockopt = sock_no_getsockopt,
3780 .sendmsg = packet_sendmsg_spkt,
3781 .recvmsg = packet_recvmsg,
3782 .mmap = sock_no_mmap,
3783 .sendpage = sock_no_sendpage,
3784 };
3785
3786 static const struct proto_ops packet_ops = {
3787 .family = PF_PACKET,
3788 .owner = THIS_MODULE,
3789 .release = packet_release,
3790 .bind = packet_bind,
3791 .connect = sock_no_connect,
3792 .socketpair = sock_no_socketpair,
3793 .accept = sock_no_accept,
3794 .getname = packet_getname,
3795 .poll = packet_poll,
3796 .ioctl = packet_ioctl,
3797 .listen = sock_no_listen,
3798 .shutdown = sock_no_shutdown,
3799 .setsockopt = packet_setsockopt,
3800 .getsockopt = packet_getsockopt,
3801 .sendmsg = packet_sendmsg,
3802 .recvmsg = packet_recvmsg,
3803 .mmap = packet_mmap,
3804 .sendpage = sock_no_sendpage,
3805 };
3806
3807 static const struct net_proto_family packet_family_ops = {
3808 .family = PF_PACKET,
3809 .create = packet_create,
3810 .owner = THIS_MODULE,
3811 };
3812
3813 static struct notifier_block packet_netdev_notifier = {
3814 .notifier_call = packet_notifier,
3815 };
3816
3817 #ifdef CONFIG_PROC_FS
3818
3819 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3820 __acquires(RCU)
3821 {
3822 struct net *net = seq_file_net(seq);
3823
3824 rcu_read_lock();
3825 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3826 }
3827
3828 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3829 {
3830 struct net *net = seq_file_net(seq);
3831 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3832 }
3833
3834 static void packet_seq_stop(struct seq_file *seq, void *v)
3835 __releases(RCU)
3836 {
3837 rcu_read_unlock();
3838 }
3839
3840 static int packet_seq_show(struct seq_file *seq, void *v)
3841 {
3842 if (v == SEQ_START_TOKEN)
3843 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3844 else {
3845 struct sock *s = sk_entry(v);
3846 const struct packet_sock *po = pkt_sk(s);
3847
3848 seq_printf(seq,
3849 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3850 s,
3851 atomic_read(&s->sk_refcnt),
3852 s->sk_type,
3853 ntohs(po->num),
3854 po->ifindex,
3855 po->running,
3856 atomic_read(&s->sk_rmem_alloc),
3857 sock_i_uid(s),
3858 sock_i_ino(s));
3859 }
3860
3861 return 0;
3862 }
3863
3864 static const struct seq_operations packet_seq_ops = {
3865 .start = packet_seq_start,
3866 .next = packet_seq_next,
3867 .stop = packet_seq_stop,
3868 .show = packet_seq_show,
3869 };
3870
3871 static int packet_seq_open(struct inode *inode, struct file *file)
3872 {
3873 return seq_open_net(inode, file, &packet_seq_ops,
3874 sizeof(struct seq_net_private));
3875 }
3876
3877 static const struct file_operations packet_seq_fops = {
3878 .owner = THIS_MODULE,
3879 .open = packet_seq_open,
3880 .read = seq_read,
3881 .llseek = seq_lseek,
3882 .release = seq_release_net,
3883 };
3884
3885 #endif
3886
3887 static int __net_init packet_net_init(struct net *net)
3888 {
3889 spin_lock_init(&net->packet.sklist_lock);
3890 INIT_HLIST_HEAD(&net->packet.sklist);
3891
3892 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
3893 return -ENOMEM;
3894
3895 return 0;
3896 }
3897
3898 static void __net_exit packet_net_exit(struct net *net)
3899 {
3900 proc_net_remove(net, "packet");
3901 }
3902
3903 static struct pernet_operations packet_net_ops = {
3904 .init = packet_net_init,
3905 .exit = packet_net_exit,
3906 };
3907
3908
3909 static void __exit packet_exit(void)
3910 {
3911 unregister_netdevice_notifier(&packet_netdev_notifier);
3912 unregister_pernet_subsys(&packet_net_ops);
3913 sock_unregister(PF_PACKET);
3914 proto_unregister(&packet_proto);
3915 }
3916
3917 static int __init packet_init(void)
3918 {
3919 int rc = proto_register(&packet_proto, 0);
3920
3921 if (rc != 0)
3922 goto out;
3923
3924 sock_register(&packet_family_ops);
3925 register_pernet_subsys(&packet_net_ops);
3926 register_netdevice_notifier(&packet_netdev_notifier);
3927 out:
3928 return rc;
3929 }
3930
3931 module_init(packet_init);
3932 module_exit(packet_exit);
3933 MODULE_LICENSE("GPL");
3934 MODULE_ALIAS_NETPROTO(PF_PACKET);
Linux kernel - Deliverables
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