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net: Add framework to allow sending packets with customized CRC.
[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/system.h>
77 #include <asm/uaccess.h>
78 #include <asm/ioctls.h>
79 #include <asm/page.h>
80 #include <asm/cacheflush.h>
81 #include <asm/io.h>
82 #include <linux/proc_fs.h>
83 #include <linux/seq_file.h>
84 #include <linux/poll.h>
85 #include <linux/module.h>
86 #include <linux/init.h>
87 #include <linux/mutex.h>
88 #include <linux/if_vlan.h>
89 #include <linux/virtio_net.h>
90 #include <linux/errqueue.h>
91 #include <linux/net_tstamp.h>
92
93 #ifdef CONFIG_INET
94 #include <net/inet_common.h>
95 #endif
96
97 /*
98 Assumptions:
99 - if device has no dev->hard_header routine, it adds and removes ll header
100 inside itself. In this case ll header is invisible outside of device,
101 but higher levels still should reserve dev->hard_header_len.
102 Some devices are enough clever to reallocate skb, when header
103 will not fit to reserved space (tunnel), another ones are silly
104 (PPP).
105 - packet socket receives packets with pulled ll header,
106 so that SOCK_RAW should push it back.
107
108 On receive:
109 -----------
110
111 Incoming, dev->hard_header!=NULL
112 mac_header -> ll header
113 data -> data
114
115 Outgoing, dev->hard_header!=NULL
116 mac_header -> ll header
117 data -> ll header
118
119 Incoming, dev->hard_header==NULL
120 mac_header -> UNKNOWN position. It is very likely, that it points to ll
121 header. PPP makes it, that is wrong, because introduce
122 assymetry between rx and tx paths.
123 data -> data
124
125 Outgoing, dev->hard_header==NULL
126 mac_header -> data. ll header is still not built!
127 data -> data
128
129 Resume
130 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
131
132
133 On transmit:
134 ------------
135
136 dev->hard_header != NULL
137 mac_header -> ll header
138 data -> ll header
139
140 dev->hard_header == NULL (ll header is added by device, we cannot control it)
141 mac_header -> data
142 data -> data
143
144 We should set nh.raw on output to correct posistion,
145 packet classifier depends on it.
146 */
147
148 /* Private packet socket structures. */
149
150 struct packet_mclist {
151 struct packet_mclist *next;
152 int ifindex;
153 int count;
154 unsigned short type;
155 unsigned short alen;
156 unsigned char addr[MAX_ADDR_LEN];
157 };
158 /* identical to struct packet_mreq except it has
159 * a longer address field.
160 */
161 struct packet_mreq_max {
162 int mr_ifindex;
163 unsigned short mr_type;
164 unsigned short mr_alen;
165 unsigned char mr_address[MAX_ADDR_LEN];
166 };
167
168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
169 int closing, int tx_ring);
170
171
172 #define V3_ALIGNMENT (8)
173
174 #define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
175
176 #define BLK_PLUS_PRIV(sz_of_priv) \
177 (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
178
179 /* kbdq - kernel block descriptor queue */
180 struct tpacket_kbdq_core {
181 struct pgv *pkbdq;
182 unsigned int feature_req_word;
183 unsigned int hdrlen;
184 unsigned char reset_pending_on_curr_blk;
185 unsigned char delete_blk_timer;
186 unsigned short kactive_blk_num;
187 unsigned short blk_sizeof_priv;
188
189 /* last_kactive_blk_num:
190 * trick to see if user-space has caught up
191 * in order to avoid refreshing timer when every single pkt arrives.
192 */
193 unsigned short last_kactive_blk_num;
194
195 char *pkblk_start;
196 char *pkblk_end;
197 int kblk_size;
198 unsigned int knum_blocks;
199 uint64_t knxt_seq_num;
200 char *prev;
201 char *nxt_offset;
202 struct sk_buff *skb;
203
204 atomic_t blk_fill_in_prog;
205
206 /* Default is set to 8ms */
207 #define DEFAULT_PRB_RETIRE_TOV (8)
208
209 unsigned short retire_blk_tov;
210 unsigned short version;
211 unsigned long tov_in_jiffies;
212
213 /* timer to retire an outstanding block */
214 struct timer_list retire_blk_timer;
215 };
216
217 #define PGV_FROM_VMALLOC 1
218 struct pgv {
219 char *buffer;
220 };
221
222 struct packet_ring_buffer {
223 struct pgv *pg_vec;
224 unsigned int head;
225 unsigned int frames_per_block;
226 unsigned int frame_size;
227 unsigned int frame_max;
228
229 unsigned int pg_vec_order;
230 unsigned int pg_vec_pages;
231 unsigned int pg_vec_len;
232
233 struct tpacket_kbdq_core prb_bdqc;
234 atomic_t pending;
235 };
236
237 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
238 #define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts)
239 #define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt)
240 #define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len)
241 #define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num)
242 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
243 #define BLOCK_PRIV(x) ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
244
245 struct packet_sock;
246 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
247
248 static void *packet_previous_frame(struct packet_sock *po,
249 struct packet_ring_buffer *rb,
250 int status);
251 static void packet_increment_head(struct packet_ring_buffer *buff);
252 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
253 struct tpacket_block_desc *);
254 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
255 struct packet_sock *);
256 static void prb_retire_current_block(struct tpacket_kbdq_core *,
257 struct packet_sock *, unsigned int status);
258 static int prb_queue_frozen(struct tpacket_kbdq_core *);
259 static void prb_open_block(struct tpacket_kbdq_core *,
260 struct tpacket_block_desc *);
261 static void prb_retire_rx_blk_timer_expired(unsigned long);
262 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
263 static void prb_init_blk_timer(struct packet_sock *,
264 struct tpacket_kbdq_core *,
265 void (*func) (unsigned long));
266 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
267 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
268 struct tpacket3_hdr *);
269 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
270 struct tpacket3_hdr *);
271 static void packet_flush_mclist(struct sock *sk);
272
273 struct packet_fanout;
274 struct packet_sock {
275 /* struct sock has to be the first member of packet_sock */
276 struct sock sk;
277 struct packet_fanout *fanout;
278 struct tpacket_stats stats;
279 union tpacket_stats_u stats_u;
280 struct packet_ring_buffer rx_ring;
281 struct packet_ring_buffer tx_ring;
282 int copy_thresh;
283 spinlock_t bind_lock;
284 struct mutex pg_vec_lock;
285 unsigned int running:1, /* prot_hook is attached*/
286 auxdata:1,
287 origdev:1,
288 has_vnet_hdr:1;
289 int ifindex; /* bound device */
290 __be16 num;
291 struct packet_mclist *mclist;
292 atomic_t mapped;
293 enum tpacket_versions tp_version;
294 unsigned int tp_hdrlen;
295 unsigned int tp_reserve;
296 unsigned int tp_loss:1;
297 unsigned int tp_tstamp;
298 struct packet_type prot_hook ____cacheline_aligned_in_smp;
299 };
300
301 #define PACKET_FANOUT_MAX 256
302
303 struct packet_fanout {
304 #ifdef CONFIG_NET_NS
305 struct net *net;
306 #endif
307 unsigned int num_members;
308 u16 id;
309 u8 type;
310 u8 defrag;
311 atomic_t rr_cur;
312 struct list_head list;
313 struct sock *arr[PACKET_FANOUT_MAX];
314 spinlock_t lock;
315 atomic_t sk_ref;
316 struct packet_type prot_hook ____cacheline_aligned_in_smp;
317 };
318
319 struct packet_skb_cb {
320 unsigned int origlen;
321 union {
322 struct sockaddr_pkt pkt;
323 struct sockaddr_ll ll;
324 } sa;
325 };
326
327 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
328
329 #define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
330 #define GET_PBLOCK_DESC(x, bid) \
331 ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
332 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \
333 ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
334 #define GET_NEXT_PRB_BLK_NUM(x) \
335 (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
336 ((x)->kactive_blk_num+1) : 0)
337
338 static struct packet_sock *pkt_sk(struct sock *sk)
339 {
340 return (struct packet_sock *)sk;
341 }
342
343 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
344 static void __fanout_link(struct sock *sk, struct packet_sock *po);
345
346 /* register_prot_hook must be invoked with the po->bind_lock held,
347 * or from a context in which asynchronous accesses to the packet
348 * socket is not possible (packet_create()).
349 */
350 static void register_prot_hook(struct sock *sk)
351 {
352 struct packet_sock *po = pkt_sk(sk);
353 if (!po->running) {
354 if (po->fanout)
355 __fanout_link(sk, po);
356 else
357 dev_add_pack(&po->prot_hook);
358 sock_hold(sk);
359 po->running = 1;
360 }
361 }
362
363 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
364 * held. If the sync parameter is true, we will temporarily drop
365 * the po->bind_lock and do a synchronize_net to make sure no
366 * asynchronous packet processing paths still refer to the elements
367 * of po->prot_hook. If the sync parameter is false, it is the
368 * callers responsibility to take care of this.
369 */
370 static void __unregister_prot_hook(struct sock *sk, bool sync)
371 {
372 struct packet_sock *po = pkt_sk(sk);
373
374 po->running = 0;
375 if (po->fanout)
376 __fanout_unlink(sk, po);
377 else
378 __dev_remove_pack(&po->prot_hook);
379 __sock_put(sk);
380
381 if (sync) {
382 spin_unlock(&po->bind_lock);
383 synchronize_net();
384 spin_lock(&po->bind_lock);
385 }
386 }
387
388 static void unregister_prot_hook(struct sock *sk, bool sync)
389 {
390 struct packet_sock *po = pkt_sk(sk);
391
392 if (po->running)
393 __unregister_prot_hook(sk, sync);
394 }
395
396 static inline __pure struct page *pgv_to_page(void *addr)
397 {
398 if (is_vmalloc_addr(addr))
399 return vmalloc_to_page(addr);
400 return virt_to_page(addr);
401 }
402
403 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
404 {
405 union {
406 struct tpacket_hdr *h1;
407 struct tpacket2_hdr *h2;
408 void *raw;
409 } h;
410
411 h.raw = frame;
412 switch (po->tp_version) {
413 case TPACKET_V1:
414 h.h1->tp_status = status;
415 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
416 break;
417 case TPACKET_V2:
418 h.h2->tp_status = status;
419 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
420 break;
421 case TPACKET_V3:
422 default:
423 WARN(1, "TPACKET version not supported.\n");
424 BUG();
425 }
426
427 smp_wmb();
428 }
429
430 static int __packet_get_status(struct packet_sock *po, void *frame)
431 {
432 union {
433 struct tpacket_hdr *h1;
434 struct tpacket2_hdr *h2;
435 void *raw;
436 } h;
437
438 smp_rmb();
439
440 h.raw = frame;
441 switch (po->tp_version) {
442 case TPACKET_V1:
443 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
444 return h.h1->tp_status;
445 case TPACKET_V2:
446 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
447 return h.h2->tp_status;
448 case TPACKET_V3:
449 default:
450 WARN(1, "TPACKET version not supported.\n");
451 BUG();
452 return 0;
453 }
454 }
455
456 static void *packet_lookup_frame(struct packet_sock *po,
457 struct packet_ring_buffer *rb,
458 unsigned int position,
459 int status)
460 {
461 unsigned int pg_vec_pos, frame_offset;
462 union {
463 struct tpacket_hdr *h1;
464 struct tpacket2_hdr *h2;
465 void *raw;
466 } h;
467
468 pg_vec_pos = position / rb->frames_per_block;
469 frame_offset = position % rb->frames_per_block;
470
471 h.raw = rb->pg_vec[pg_vec_pos].buffer +
472 (frame_offset * rb->frame_size);
473
474 if (status != __packet_get_status(po, h.raw))
475 return NULL;
476
477 return h.raw;
478 }
479
480 static void *packet_current_frame(struct packet_sock *po,
481 struct packet_ring_buffer *rb,
482 int status)
483 {
484 return packet_lookup_frame(po, rb, rb->head, status);
485 }
486
487 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
488 {
489 del_timer_sync(&pkc->retire_blk_timer);
490 }
491
492 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
493 int tx_ring,
494 struct sk_buff_head *rb_queue)
495 {
496 struct tpacket_kbdq_core *pkc;
497
498 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
499
500 spin_lock(&rb_queue->lock);
501 pkc->delete_blk_timer = 1;
502 spin_unlock(&rb_queue->lock);
503
504 prb_del_retire_blk_timer(pkc);
505 }
506
507 static void prb_init_blk_timer(struct packet_sock *po,
508 struct tpacket_kbdq_core *pkc,
509 void (*func) (unsigned long))
510 {
511 init_timer(&pkc->retire_blk_timer);
512 pkc->retire_blk_timer.data = (long)po;
513 pkc->retire_blk_timer.function = func;
514 pkc->retire_blk_timer.expires = jiffies;
515 }
516
517 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
518 {
519 struct tpacket_kbdq_core *pkc;
520
521 if (tx_ring)
522 BUG();
523
524 pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
525 prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
526 }
527
528 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
529 int blk_size_in_bytes)
530 {
531 struct net_device *dev;
532 unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
533 struct ethtool_cmd ecmd;
534 int err;
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 rtnl_unlock();
544 if (!err) {
545 switch (ecmd.speed) {
546 case SPEED_10000:
547 msec = 1;
548 div = 10000/1000;
549 break;
550 case SPEED_1000:
551 msec = 1;
552 div = 1000/1000;
553 break;
554 /*
555 * If the link speed is so slow you don't really
556 * need to worry about perf anyways
557 */
558 case SPEED_100:
559 case SPEED_10:
560 default:
561 return DEFAULT_PRB_RETIRE_TOV;
562 }
563 }
564
565 mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
566
567 if (div)
568 mbits /= div;
569
570 tmo = mbits * msec;
571
572 if (div)
573 return tmo+1;
574 return tmo;
575 }
576
577 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
578 union tpacket_req_u *req_u)
579 {
580 p1->feature_req_word = req_u->req3.tp_feature_req_word;
581 }
582
583 static void init_prb_bdqc(struct packet_sock *po,
584 struct packet_ring_buffer *rb,
585 struct pgv *pg_vec,
586 union tpacket_req_u *req_u, int tx_ring)
587 {
588 struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
589 struct tpacket_block_desc *pbd;
590
591 memset(p1, 0x0, sizeof(*p1));
592
593 p1->knxt_seq_num = 1;
594 p1->pkbdq = pg_vec;
595 pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
596 p1->pkblk_start = (char *)pg_vec[0].buffer;
597 p1->kblk_size = req_u->req3.tp_block_size;
598 p1->knum_blocks = req_u->req3.tp_block_nr;
599 p1->hdrlen = po->tp_hdrlen;
600 p1->version = po->tp_version;
601 p1->last_kactive_blk_num = 0;
602 po->stats_u.stats3.tp_freeze_q_cnt = 0;
603 if (req_u->req3.tp_retire_blk_tov)
604 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
605 else
606 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
607 req_u->req3.tp_block_size);
608 p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
609 p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
610
611 prb_init_ft_ops(p1, req_u);
612 prb_setup_retire_blk_timer(po, tx_ring);
613 prb_open_block(p1, pbd);
614 }
615
616 /* Do NOT update the last_blk_num first.
617 * Assumes sk_buff_head lock is held.
618 */
619 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
620 {
621 mod_timer(&pkc->retire_blk_timer,
622 jiffies + pkc->tov_in_jiffies);
623 pkc->last_kactive_blk_num = pkc->kactive_blk_num;
624 }
625
626 /*
627 * Timer logic:
628 * 1) We refresh the timer only when we open a block.
629 * By doing this we don't waste cycles refreshing the timer
630 * on packet-by-packet basis.
631 *
632 * With a 1MB block-size, on a 1Gbps line, it will take
633 * i) ~8 ms to fill a block + ii) memcpy etc.
634 * In this cut we are not accounting for the memcpy time.
635 *
636 * So, if the user sets the 'tmo' to 10ms then the timer
637 * will never fire while the block is still getting filled
638 * (which is what we want). However, the user could choose
639 * to close a block early and that's fine.
640 *
641 * But when the timer does fire, we check whether or not to refresh it.
642 * Since the tmo granularity is in msecs, it is not too expensive
643 * to refresh the timer, lets say every '8' msecs.
644 * Either the user can set the 'tmo' or we can derive it based on
645 * a) line-speed and b) block-size.
646 * prb_calc_retire_blk_tmo() calculates the tmo.
647 *
648 */
649 static void prb_retire_rx_blk_timer_expired(unsigned long data)
650 {
651 struct packet_sock *po = (struct packet_sock *)data;
652 struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
653 unsigned int frozen;
654 struct tpacket_block_desc *pbd;
655
656 spin_lock(&po->sk.sk_receive_queue.lock);
657
658 frozen = prb_queue_frozen(pkc);
659 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
660
661 if (unlikely(pkc->delete_blk_timer))
662 goto out;
663
664 /* We only need to plug the race when the block is partially filled.
665 * tpacket_rcv:
666 * lock(); increment BLOCK_NUM_PKTS; unlock()
667 * copy_bits() is in progress ...
668 * timer fires on other cpu:
669 * we can't retire the current block because copy_bits
670 * is in progress.
671 *
672 */
673 if (BLOCK_NUM_PKTS(pbd)) {
674 while (atomic_read(&pkc->blk_fill_in_prog)) {
675 /* Waiting for skb_copy_bits to finish... */
676 cpu_relax();
677 }
678 }
679
680 if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
681 if (!frozen) {
682 prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
683 if (!prb_dispatch_next_block(pkc, po))
684 goto refresh_timer;
685 else
686 goto out;
687 } else {
688 /* Case 1. Queue was frozen because user-space was
689 * lagging behind.
690 */
691 if (prb_curr_blk_in_use(pkc, pbd)) {
692 /*
693 * Ok, user-space is still behind.
694 * So just refresh the timer.
695 */
696 goto refresh_timer;
697 } else {
698 /* Case 2. queue was frozen,user-space caught up,
699 * now the link went idle && the timer fired.
700 * We don't have a block to close.So we open this
701 * block and restart the timer.
702 * opening a block thaws the queue,restarts timer
703 * Thawing/timer-refresh is a side effect.
704 */
705 prb_open_block(pkc, pbd);
706 goto out;
707 }
708 }
709 }
710
711 refresh_timer:
712 _prb_refresh_rx_retire_blk_timer(pkc);
713
714 out:
715 spin_unlock(&po->sk.sk_receive_queue.lock);
716 }
717
718 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
719 struct tpacket_block_desc *pbd1, __u32 status)
720 {
721 /* Flush everything minus the block header */
722
723 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
724 u8 *start, *end;
725
726 start = (u8 *)pbd1;
727
728 /* Skip the block header(we know header WILL fit in 4K) */
729 start += PAGE_SIZE;
730
731 end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
732 for (; start < end; start += PAGE_SIZE)
733 flush_dcache_page(pgv_to_page(start));
734
735 smp_wmb();
736 #endif
737
738 /* Now update the block status. */
739
740 BLOCK_STATUS(pbd1) = status;
741
742 /* Flush the block header */
743
744 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
745 start = (u8 *)pbd1;
746 flush_dcache_page(pgv_to_page(start));
747
748 smp_wmb();
749 #endif
750 }
751
752 /*
753 * Side effect:
754 *
755 * 1) flush the block
756 * 2) Increment active_blk_num
757 *
758 * Note:We DONT refresh the timer on purpose.
759 * Because almost always the next block will be opened.
760 */
761 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
762 struct tpacket_block_desc *pbd1,
763 struct packet_sock *po, unsigned int stat)
764 {
765 __u32 status = TP_STATUS_USER | stat;
766
767 struct tpacket3_hdr *last_pkt;
768 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
769
770 if (po->stats.tp_drops)
771 status |= TP_STATUS_LOSING;
772
773 last_pkt = (struct tpacket3_hdr *)pkc1->prev;
774 last_pkt->tp_next_offset = 0;
775
776 /* Get the ts of the last pkt */
777 if (BLOCK_NUM_PKTS(pbd1)) {
778 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
779 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
780 } else {
781 /* Ok, we tmo'd - so get the current time */
782 struct timespec ts;
783 getnstimeofday(&ts);
784 h1->ts_last_pkt.ts_sec = ts.tv_sec;
785 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
786 }
787
788 smp_wmb();
789
790 /* Flush the block */
791 prb_flush_block(pkc1, pbd1, status);
792
793 pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
794 }
795
796 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
797 {
798 pkc->reset_pending_on_curr_blk = 0;
799 }
800
801 /*
802 * Side effect of opening a block:
803 *
804 * 1) prb_queue is thawed.
805 * 2) retire_blk_timer is refreshed.
806 *
807 */
808 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
809 struct tpacket_block_desc *pbd1)
810 {
811 struct timespec ts;
812 struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
813
814 smp_rmb();
815
816 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) {
817
818 /* We could have just memset this but we will lose the
819 * flexibility of making the priv area sticky
820 */
821 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
822 BLOCK_NUM_PKTS(pbd1) = 0;
823 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
824 getnstimeofday(&ts);
825 h1->ts_first_pkt.ts_sec = ts.tv_sec;
826 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
827 pkc1->pkblk_start = (char *)pbd1;
828 pkc1->nxt_offset = (char *)(pkc1->pkblk_start +
829 BLK_PLUS_PRIV(pkc1->blk_sizeof_priv));
830 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
831 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
832 pbd1->version = pkc1->version;
833 pkc1->prev = pkc1->nxt_offset;
834 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
835 prb_thaw_queue(pkc1);
836 _prb_refresh_rx_retire_blk_timer(pkc1);
837
838 smp_wmb();
839
840 return;
841 }
842
843 WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n",
844 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num);
845 dump_stack();
846 BUG();
847 }
848
849 /*
850 * Queue freeze logic:
851 * 1) Assume tp_block_nr = 8 blocks.
852 * 2) At time 't0', user opens Rx ring.
853 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
854 * 4) user-space is either sleeping or processing block '0'.
855 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
856 * it will close block-7,loop around and try to fill block '0'.
857 * call-flow:
858 * __packet_lookup_frame_in_block
859 * prb_retire_current_block()
860 * prb_dispatch_next_block()
861 * |->(BLOCK_STATUS == USER) evaluates to true
862 * 5.1) Since block-0 is currently in-use, we just freeze the queue.
863 * 6) Now there are two cases:
864 * 6.1) Link goes idle right after the queue is frozen.
865 * But remember, the last open_block() refreshed the timer.
866 * When this timer expires,it will refresh itself so that we can
867 * re-open block-0 in near future.
868 * 6.2) Link is busy and keeps on receiving packets. This is a simple
869 * case and __packet_lookup_frame_in_block will check if block-0
870 * is free and can now be re-used.
871 */
872 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
873 struct packet_sock *po)
874 {
875 pkc->reset_pending_on_curr_blk = 1;
876 po->stats_u.stats3.tp_freeze_q_cnt++;
877 }
878
879 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
880
881 /*
882 * If the next block is free then we will dispatch it
883 * and return a good offset.
884 * Else, we will freeze the queue.
885 * So, caller must check the return value.
886 */
887 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
888 struct packet_sock *po)
889 {
890 struct tpacket_block_desc *pbd;
891
892 smp_rmb();
893
894 /* 1. Get current block num */
895 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
896
897 /* 2. If this block is currently in_use then freeze the queue */
898 if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
899 prb_freeze_queue(pkc, po);
900 return NULL;
901 }
902
903 /*
904 * 3.
905 * open this block and return the offset where the first packet
906 * needs to get stored.
907 */
908 prb_open_block(pkc, pbd);
909 return (void *)pkc->nxt_offset;
910 }
911
912 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
913 struct packet_sock *po, unsigned int status)
914 {
915 struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
916
917 /* retire/close the current block */
918 if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
919 /*
920 * Plug the case where copy_bits() is in progress on
921 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
922 * have space to copy the pkt in the current block and
923 * called prb_retire_current_block()
924 *
925 * We don't need to worry about the TMO case because
926 * the timer-handler already handled this case.
927 */
928 if (!(status & TP_STATUS_BLK_TMO)) {
929 while (atomic_read(&pkc->blk_fill_in_prog)) {
930 /* Waiting for skb_copy_bits to finish... */
931 cpu_relax();
932 }
933 }
934 prb_close_block(pkc, pbd, po, status);
935 return;
936 }
937
938 WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd);
939 dump_stack();
940 BUG();
941 }
942
943 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
944 struct tpacket_block_desc *pbd)
945 {
946 return TP_STATUS_USER & BLOCK_STATUS(pbd);
947 }
948
949 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
950 {
951 return pkc->reset_pending_on_curr_blk;
952 }
953
954 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
955 {
956 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
957 atomic_dec(&pkc->blk_fill_in_prog);
958 }
959
960 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
961 struct tpacket3_hdr *ppd)
962 {
963 ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
964 }
965
966 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
967 struct tpacket3_hdr *ppd)
968 {
969 ppd->hv1.tp_rxhash = 0;
970 }
971
972 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
973 struct tpacket3_hdr *ppd)
974 {
975 if (vlan_tx_tag_present(pkc->skb)) {
976 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
977 ppd->tp_status = TP_STATUS_VLAN_VALID;
978 } else {
979 ppd->hv1.tp_vlan_tci = ppd->tp_status = 0;
980 }
981 }
982
983 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
984 struct tpacket3_hdr *ppd)
985 {
986 prb_fill_vlan_info(pkc, ppd);
987
988 if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
989 prb_fill_rxhash(pkc, ppd);
990 else
991 prb_clear_rxhash(pkc, ppd);
992 }
993
994 static void prb_fill_curr_block(char *curr,
995 struct tpacket_kbdq_core *pkc,
996 struct tpacket_block_desc *pbd,
997 unsigned int len)
998 {
999 struct tpacket3_hdr *ppd;
1000
1001 ppd = (struct tpacket3_hdr *)curr;
1002 ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1003 pkc->prev = curr;
1004 pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1005 BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1006 BLOCK_NUM_PKTS(pbd) += 1;
1007 atomic_inc(&pkc->blk_fill_in_prog);
1008 prb_run_all_ft_ops(pkc, ppd);
1009 }
1010
1011 /* Assumes caller has the sk->rx_queue.lock */
1012 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1013 struct sk_buff *skb,
1014 int status,
1015 unsigned int len
1016 )
1017 {
1018 struct tpacket_kbdq_core *pkc;
1019 struct tpacket_block_desc *pbd;
1020 char *curr, *end;
1021
1022 pkc = GET_PBDQC_FROM_RB(((struct packet_ring_buffer *)&po->rx_ring));
1023 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1024
1025 /* Queue is frozen when user space is lagging behind */
1026 if (prb_queue_frozen(pkc)) {
1027 /*
1028 * Check if that last block which caused the queue to freeze,
1029 * is still in_use by user-space.
1030 */
1031 if (prb_curr_blk_in_use(pkc, pbd)) {
1032 /* Can't record this packet */
1033 return NULL;
1034 } else {
1035 /*
1036 * Ok, the block was released by user-space.
1037 * Now let's open that block.
1038 * opening a block also thaws the queue.
1039 * Thawing is a side effect.
1040 */
1041 prb_open_block(pkc, pbd);
1042 }
1043 }
1044
1045 smp_mb();
1046 curr = pkc->nxt_offset;
1047 pkc->skb = skb;
1048 end = (char *) ((char *)pbd + pkc->kblk_size);
1049
1050 /* first try the current block */
1051 if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1052 prb_fill_curr_block(curr, pkc, pbd, len);
1053 return (void *)curr;
1054 }
1055
1056 /* Ok, close the current block */
1057 prb_retire_current_block(pkc, po, 0);
1058
1059 /* Now, try to dispatch the next block */
1060 curr = (char *)prb_dispatch_next_block(pkc, po);
1061 if (curr) {
1062 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1063 prb_fill_curr_block(curr, pkc, pbd, len);
1064 return (void *)curr;
1065 }
1066
1067 /*
1068 * No free blocks are available.user_space hasn't caught up yet.
1069 * Queue was just frozen and now this packet will get dropped.
1070 */
1071 return NULL;
1072 }
1073
1074 static void *packet_current_rx_frame(struct packet_sock *po,
1075 struct sk_buff *skb,
1076 int status, unsigned int len)
1077 {
1078 char *curr = NULL;
1079 switch (po->tp_version) {
1080 case TPACKET_V1:
1081 case TPACKET_V2:
1082 curr = packet_lookup_frame(po, &po->rx_ring,
1083 po->rx_ring.head, status);
1084 return curr;
1085 case TPACKET_V3:
1086 return __packet_lookup_frame_in_block(po, skb, status, len);
1087 default:
1088 WARN(1, "TPACKET version not supported\n");
1089 BUG();
1090 return 0;
1091 }
1092 }
1093
1094 static void *prb_lookup_block(struct packet_sock *po,
1095 struct packet_ring_buffer *rb,
1096 unsigned int previous,
1097 int status)
1098 {
1099 struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb);
1100 struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
1101
1102 if (status != BLOCK_STATUS(pbd))
1103 return NULL;
1104 return pbd;
1105 }
1106
1107 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1108 {
1109 unsigned int prev;
1110 if (rb->prb_bdqc.kactive_blk_num)
1111 prev = rb->prb_bdqc.kactive_blk_num-1;
1112 else
1113 prev = rb->prb_bdqc.knum_blocks-1;
1114 return prev;
1115 }
1116
1117 /* Assumes caller has held the rx_queue.lock */
1118 static void *__prb_previous_block(struct packet_sock *po,
1119 struct packet_ring_buffer *rb,
1120 int status)
1121 {
1122 unsigned int previous = prb_previous_blk_num(rb);
1123 return prb_lookup_block(po, rb, previous, status);
1124 }
1125
1126 static void *packet_previous_rx_frame(struct packet_sock *po,
1127 struct packet_ring_buffer *rb,
1128 int status)
1129 {
1130 if (po->tp_version <= TPACKET_V2)
1131 return packet_previous_frame(po, rb, status);
1132
1133 return __prb_previous_block(po, rb, status);
1134 }
1135
1136 static void packet_increment_rx_head(struct packet_sock *po,
1137 struct packet_ring_buffer *rb)
1138 {
1139 switch (po->tp_version) {
1140 case TPACKET_V1:
1141 case TPACKET_V2:
1142 return packet_increment_head(rb);
1143 case TPACKET_V3:
1144 default:
1145 WARN(1, "TPACKET version not supported.\n");
1146 BUG();
1147 return;
1148 }
1149 }
1150
1151 static void *packet_previous_frame(struct packet_sock *po,
1152 struct packet_ring_buffer *rb,
1153 int status)
1154 {
1155 unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1156 return packet_lookup_frame(po, rb, previous, status);
1157 }
1158
1159 static void packet_increment_head(struct packet_ring_buffer *buff)
1160 {
1161 buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1162 }
1163
1164 static void packet_sock_destruct(struct sock *sk)
1165 {
1166 skb_queue_purge(&sk->sk_error_queue);
1167
1168 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1169 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1170
1171 if (!sock_flag(sk, SOCK_DEAD)) {
1172 pr_err("Attempt to release alive packet socket: %p\n", sk);
1173 return;
1174 }
1175
1176 sk_refcnt_debug_dec(sk);
1177 }
1178
1179 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1180 {
1181 int x = atomic_read(&f->rr_cur) + 1;
1182
1183 if (x >= num)
1184 x = 0;
1185
1186 return x;
1187 }
1188
1189 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1190 {
1191 u32 idx, hash = skb->rxhash;
1192
1193 idx = ((u64)hash * num) >> 32;
1194
1195 return f->arr[idx];
1196 }
1197
1198 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1199 {
1200 int cur, old;
1201
1202 cur = atomic_read(&f->rr_cur);
1203 while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1204 fanout_rr_next(f, num))) != cur)
1205 cur = old;
1206 return f->arr[cur];
1207 }
1208
1209 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1210 {
1211 unsigned int cpu = smp_processor_id();
1212
1213 return f->arr[cpu % num];
1214 }
1215
1216 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1217 struct packet_type *pt, struct net_device *orig_dev)
1218 {
1219 struct packet_fanout *f = pt->af_packet_priv;
1220 unsigned int num = f->num_members;
1221 struct packet_sock *po;
1222 struct sock *sk;
1223
1224 if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1225 !num) {
1226 kfree_skb(skb);
1227 return 0;
1228 }
1229
1230 switch (f->type) {
1231 case PACKET_FANOUT_HASH:
1232 default:
1233 if (f->defrag) {
1234 skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1235 if (!skb)
1236 return 0;
1237 }
1238 skb_get_rxhash(skb);
1239 sk = fanout_demux_hash(f, skb, num);
1240 break;
1241 case PACKET_FANOUT_LB:
1242 sk = fanout_demux_lb(f, skb, num);
1243 break;
1244 case PACKET_FANOUT_CPU:
1245 sk = fanout_demux_cpu(f, skb, num);
1246 break;
1247 }
1248
1249 po = pkt_sk(sk);
1250
1251 return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1252 }
1253
1254 static DEFINE_MUTEX(fanout_mutex);
1255 static LIST_HEAD(fanout_list);
1256
1257 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1258 {
1259 struct packet_fanout *f = po->fanout;
1260
1261 spin_lock(&f->lock);
1262 f->arr[f->num_members] = sk;
1263 smp_wmb();
1264 f->num_members++;
1265 spin_unlock(&f->lock);
1266 }
1267
1268 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1269 {
1270 struct packet_fanout *f = po->fanout;
1271 int i;
1272
1273 spin_lock(&f->lock);
1274 for (i = 0; i < f->num_members; i++) {
1275 if (f->arr[i] == sk)
1276 break;
1277 }
1278 BUG_ON(i >= f->num_members);
1279 f->arr[i] = f->arr[f->num_members - 1];
1280 f->num_members--;
1281 spin_unlock(&f->lock);
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 dev_add_pack(&match->prot_hook);
1337 list_add(&match->list, &fanout_list);
1338 }
1339 err = -EINVAL;
1340 if (match->type == type &&
1341 match->prot_hook.type == po->prot_hook.type &&
1342 match->prot_hook.dev == po->prot_hook.dev) {
1343 err = -ENOSPC;
1344 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1345 __dev_remove_pack(&po->prot_hook);
1346 po->fanout = match;
1347 atomic_inc(&match->sk_ref);
1348 __fanout_link(sk, po);
1349 err = 0;
1350 }
1351 }
1352 out:
1353 mutex_unlock(&fanout_mutex);
1354 return err;
1355 }
1356
1357 static void fanout_release(struct sock *sk)
1358 {
1359 struct packet_sock *po = pkt_sk(sk);
1360 struct packet_fanout *f;
1361
1362 f = po->fanout;
1363 if (!f)
1364 return;
1365
1366 po->fanout = NULL;
1367
1368 mutex_lock(&fanout_mutex);
1369 if (atomic_dec_and_test(&f->sk_ref)) {
1370 list_del(&f->list);
1371 dev_remove_pack(&f->prot_hook);
1372 kfree(f);
1373 }
1374 mutex_unlock(&fanout_mutex);
1375 }
1376
1377 static const struct proto_ops packet_ops;
1378
1379 static const struct proto_ops packet_ops_spkt;
1380
1381 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1382 struct packet_type *pt, struct net_device *orig_dev)
1383 {
1384 struct sock *sk;
1385 struct sockaddr_pkt *spkt;
1386
1387 /*
1388 * When we registered the protocol we saved the socket in the data
1389 * field for just this event.
1390 */
1391
1392 sk = pt->af_packet_priv;
1393
1394 /*
1395 * Yank back the headers [hope the device set this
1396 * right or kerboom...]
1397 *
1398 * Incoming packets have ll header pulled,
1399 * push it back.
1400 *
1401 * For outgoing ones skb->data == skb_mac_header(skb)
1402 * so that this procedure is noop.
1403 */
1404
1405 if (skb->pkt_type == PACKET_LOOPBACK)
1406 goto out;
1407
1408 if (!net_eq(dev_net(dev), sock_net(sk)))
1409 goto out;
1410
1411 skb = skb_share_check(skb, GFP_ATOMIC);
1412 if (skb == NULL)
1413 goto oom;
1414
1415 /* drop any routing info */
1416 skb_dst_drop(skb);
1417
1418 /* drop conntrack reference */
1419 nf_reset(skb);
1420
1421 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1422
1423 skb_push(skb, skb->data - skb_mac_header(skb));
1424
1425 /*
1426 * The SOCK_PACKET socket receives _all_ frames.
1427 */
1428
1429 spkt->spkt_family = dev->type;
1430 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1431 spkt->spkt_protocol = skb->protocol;
1432
1433 /*
1434 * Charge the memory to the socket. This is done specifically
1435 * to prevent sockets using all the memory up.
1436 */
1437
1438 if (sock_queue_rcv_skb(sk, skb) == 0)
1439 return 0;
1440
1441 out:
1442 kfree_skb(skb);
1443 oom:
1444 return 0;
1445 }
1446
1447
1448 /*
1449 * Output a raw packet to a device layer. This bypasses all the other
1450 * protocol layers and you must therefore supply it with a complete frame
1451 */
1452
1453 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1454 struct msghdr *msg, size_t len)
1455 {
1456 struct sock *sk = sock->sk;
1457 struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1458 struct sk_buff *skb = NULL;
1459 struct net_device *dev;
1460 __be16 proto = 0;
1461 int err;
1462 int extra_len = 0;
1463
1464 /*
1465 * Get and verify the address.
1466 */
1467
1468 if (saddr) {
1469 if (msg->msg_namelen < sizeof(struct sockaddr))
1470 return -EINVAL;
1471 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1472 proto = saddr->spkt_protocol;
1473 } else
1474 return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */
1475
1476 /*
1477 * Find the device first to size check it
1478 */
1479
1480 saddr->spkt_device[13] = 0;
1481 retry:
1482 rcu_read_lock();
1483 dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1484 err = -ENODEV;
1485 if (dev == NULL)
1486 goto out_unlock;
1487
1488 err = -ENETDOWN;
1489 if (!(dev->flags & IFF_UP))
1490 goto out_unlock;
1491
1492 /*
1493 * You may not queue a frame bigger than the mtu. This is the lowest level
1494 * raw protocol and you must do your own fragmentation at this level.
1495 */
1496
1497 if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1498 if (!netif_supports_nofcs(dev)) {
1499 err = -EPROTONOSUPPORT;
1500 goto out_unlock;
1501 }
1502 extra_len = 4; /* We're doing our own CRC */
1503 }
1504
1505 err = -EMSGSIZE;
1506 if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1507 goto out_unlock;
1508
1509 if (!skb) {
1510 size_t reserved = LL_RESERVED_SPACE(dev);
1511 int tlen = dev->needed_tailroom;
1512 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1513
1514 rcu_read_unlock();
1515 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1516 if (skb == NULL)
1517 return -ENOBUFS;
1518 /* FIXME: Save some space for broken drivers that write a hard
1519 * header at transmission time by themselves. PPP is the notable
1520 * one here. This should really be fixed at the driver level.
1521 */
1522 skb_reserve(skb, reserved);
1523 skb_reset_network_header(skb);
1524
1525 /* Try to align data part correctly */
1526 if (hhlen) {
1527 skb->data -= hhlen;
1528 skb->tail -= hhlen;
1529 if (len < hhlen)
1530 skb_reset_network_header(skb);
1531 }
1532 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1533 if (err)
1534 goto out_free;
1535 goto retry;
1536 }
1537
1538 if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1539 /* Earlier code assumed this would be a VLAN pkt,
1540 * double-check this now that we have the actual
1541 * packet in hand.
1542 */
1543 struct ethhdr *ehdr;
1544 skb_reset_mac_header(skb);
1545 ehdr = eth_hdr(skb);
1546 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1547 err = -EMSGSIZE;
1548 goto out_unlock;
1549 }
1550 }
1551
1552 skb->protocol = proto;
1553 skb->dev = dev;
1554 skb->priority = sk->sk_priority;
1555 skb->mark = sk->sk_mark;
1556 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1557 if (err < 0)
1558 goto out_unlock;
1559
1560 if (unlikely(extra_len == 4))
1561 skb->no_fcs = 1;
1562
1563 dev_queue_xmit(skb);
1564 rcu_read_unlock();
1565 return len;
1566
1567 out_unlock:
1568 rcu_read_unlock();
1569 out_free:
1570 kfree_skb(skb);
1571 return err;
1572 }
1573
1574 static unsigned int run_filter(const struct sk_buff *skb,
1575 const struct sock *sk,
1576 unsigned int res)
1577 {
1578 struct sk_filter *filter;
1579
1580 rcu_read_lock();
1581 filter = rcu_dereference(sk->sk_filter);
1582 if (filter != NULL)
1583 res = SK_RUN_FILTER(filter, skb);
1584 rcu_read_unlock();
1585
1586 return res;
1587 }
1588
1589 /*
1590 * This function makes lazy skb cloning in hope that most of packets
1591 * are discarded by BPF.
1592 *
1593 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1594 * and skb->cb are mangled. It works because (and until) packets
1595 * falling here are owned by current CPU. Output packets are cloned
1596 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1597 * sequencially, so that if we return skb to original state on exit,
1598 * we will not harm anyone.
1599 */
1600
1601 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1602 struct packet_type *pt, struct net_device *orig_dev)
1603 {
1604 struct sock *sk;
1605 struct sockaddr_ll *sll;
1606 struct packet_sock *po;
1607 u8 *skb_head = skb->data;
1608 int skb_len = skb->len;
1609 unsigned int snaplen, res;
1610
1611 if (skb->pkt_type == PACKET_LOOPBACK)
1612 goto drop;
1613
1614 sk = pt->af_packet_priv;
1615 po = pkt_sk(sk);
1616
1617 if (!net_eq(dev_net(dev), sock_net(sk)))
1618 goto drop;
1619
1620 skb->dev = dev;
1621
1622 if (dev->header_ops) {
1623 /* The device has an explicit notion of ll header,
1624 * exported to higher levels.
1625 *
1626 * Otherwise, the device hides details of its frame
1627 * structure, so that corresponding packet head is
1628 * never delivered to user.
1629 */
1630 if (sk->sk_type != SOCK_DGRAM)
1631 skb_push(skb, skb->data - skb_mac_header(skb));
1632 else if (skb->pkt_type == PACKET_OUTGOING) {
1633 /* Special case: outgoing packets have ll header at head */
1634 skb_pull(skb, skb_network_offset(skb));
1635 }
1636 }
1637
1638 snaplen = skb->len;
1639
1640 res = run_filter(skb, sk, snaplen);
1641 if (!res)
1642 goto drop_n_restore;
1643 if (snaplen > res)
1644 snaplen = res;
1645
1646 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1647 goto drop_n_acct;
1648
1649 if (skb_shared(skb)) {
1650 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1651 if (nskb == NULL)
1652 goto drop_n_acct;
1653
1654 if (skb_head != skb->data) {
1655 skb->data = skb_head;
1656 skb->len = skb_len;
1657 }
1658 kfree_skb(skb);
1659 skb = nskb;
1660 }
1661
1662 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1663 sizeof(skb->cb));
1664
1665 sll = &PACKET_SKB_CB(skb)->sa.ll;
1666 sll->sll_family = AF_PACKET;
1667 sll->sll_hatype = dev->type;
1668 sll->sll_protocol = skb->protocol;
1669 sll->sll_pkttype = skb->pkt_type;
1670 if (unlikely(po->origdev))
1671 sll->sll_ifindex = orig_dev->ifindex;
1672 else
1673 sll->sll_ifindex = dev->ifindex;
1674
1675 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1676
1677 PACKET_SKB_CB(skb)->origlen = skb->len;
1678
1679 if (pskb_trim(skb, snaplen))
1680 goto drop_n_acct;
1681
1682 skb_set_owner_r(skb, sk);
1683 skb->dev = NULL;
1684 skb_dst_drop(skb);
1685
1686 /* drop conntrack reference */
1687 nf_reset(skb);
1688
1689 spin_lock(&sk->sk_receive_queue.lock);
1690 po->stats.tp_packets++;
1691 skb->dropcount = atomic_read(&sk->sk_drops);
1692 __skb_queue_tail(&sk->sk_receive_queue, skb);
1693 spin_unlock(&sk->sk_receive_queue.lock);
1694 sk->sk_data_ready(sk, skb->len);
1695 return 0;
1696
1697 drop_n_acct:
1698 spin_lock(&sk->sk_receive_queue.lock);
1699 po->stats.tp_drops++;
1700 atomic_inc(&sk->sk_drops);
1701 spin_unlock(&sk->sk_receive_queue.lock);
1702
1703 drop_n_restore:
1704 if (skb_head != skb->data && skb_shared(skb)) {
1705 skb->data = skb_head;
1706 skb->len = skb_len;
1707 }
1708 drop:
1709 consume_skb(skb);
1710 return 0;
1711 }
1712
1713 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1714 struct packet_type *pt, struct net_device *orig_dev)
1715 {
1716 struct sock *sk;
1717 struct packet_sock *po;
1718 struct sockaddr_ll *sll;
1719 union {
1720 struct tpacket_hdr *h1;
1721 struct tpacket2_hdr *h2;
1722 struct tpacket3_hdr *h3;
1723 void *raw;
1724 } h;
1725 u8 *skb_head = skb->data;
1726 int skb_len = skb->len;
1727 unsigned int snaplen, res;
1728 unsigned long status = TP_STATUS_USER;
1729 unsigned short macoff, netoff, hdrlen;
1730 struct sk_buff *copy_skb = NULL;
1731 struct timeval tv;
1732 struct timespec ts;
1733 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
1734
1735 if (skb->pkt_type == PACKET_LOOPBACK)
1736 goto drop;
1737
1738 sk = pt->af_packet_priv;
1739 po = pkt_sk(sk);
1740
1741 if (!net_eq(dev_net(dev), sock_net(sk)))
1742 goto drop;
1743
1744 if (dev->header_ops) {
1745 if (sk->sk_type != SOCK_DGRAM)
1746 skb_push(skb, skb->data - skb_mac_header(skb));
1747 else if (skb->pkt_type == PACKET_OUTGOING) {
1748 /* Special case: outgoing packets have ll header at head */
1749 skb_pull(skb, skb_network_offset(skb));
1750 }
1751 }
1752
1753 if (skb->ip_summed == CHECKSUM_PARTIAL)
1754 status |= TP_STATUS_CSUMNOTREADY;
1755
1756 snaplen = skb->len;
1757
1758 res = run_filter(skb, sk, snaplen);
1759 if (!res)
1760 goto drop_n_restore;
1761 if (snaplen > res)
1762 snaplen = res;
1763
1764 if (sk->sk_type == SOCK_DGRAM) {
1765 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1766 po->tp_reserve;
1767 } else {
1768 unsigned maclen = skb_network_offset(skb);
1769 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1770 (maclen < 16 ? 16 : maclen)) +
1771 po->tp_reserve;
1772 macoff = netoff - maclen;
1773 }
1774 if (po->tp_version <= TPACKET_V2) {
1775 if (macoff + snaplen > po->rx_ring.frame_size) {
1776 if (po->copy_thresh &&
1777 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1778 if (skb_shared(skb)) {
1779 copy_skb = skb_clone(skb, GFP_ATOMIC);
1780 } else {
1781 copy_skb = skb_get(skb);
1782 skb_head = skb->data;
1783 }
1784 if (copy_skb)
1785 skb_set_owner_r(copy_skb, sk);
1786 }
1787 snaplen = po->rx_ring.frame_size - macoff;
1788 if ((int)snaplen < 0)
1789 snaplen = 0;
1790 }
1791 }
1792 spin_lock(&sk->sk_receive_queue.lock);
1793 h.raw = packet_current_rx_frame(po, skb,
1794 TP_STATUS_KERNEL, (macoff+snaplen));
1795 if (!h.raw)
1796 goto ring_is_full;
1797 if (po->tp_version <= TPACKET_V2) {
1798 packet_increment_rx_head(po, &po->rx_ring);
1799 /*
1800 * LOSING will be reported till you read the stats,
1801 * because it's COR - Clear On Read.
1802 * Anyways, moving it for V1/V2 only as V3 doesn't need this
1803 * at packet level.
1804 */
1805 if (po->stats.tp_drops)
1806 status |= TP_STATUS_LOSING;
1807 }
1808 po->stats.tp_packets++;
1809 if (copy_skb) {
1810 status |= TP_STATUS_COPY;
1811 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1812 }
1813 spin_unlock(&sk->sk_receive_queue.lock);
1814
1815 skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1816
1817 switch (po->tp_version) {
1818 case TPACKET_V1:
1819 h.h1->tp_len = skb->len;
1820 h.h1->tp_snaplen = snaplen;
1821 h.h1->tp_mac = macoff;
1822 h.h1->tp_net = netoff;
1823 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1824 && shhwtstamps->syststamp.tv64)
1825 tv = ktime_to_timeval(shhwtstamps->syststamp);
1826 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1827 && shhwtstamps->hwtstamp.tv64)
1828 tv = ktime_to_timeval(shhwtstamps->hwtstamp);
1829 else if (skb->tstamp.tv64)
1830 tv = ktime_to_timeval(skb->tstamp);
1831 else
1832 do_gettimeofday(&tv);
1833 h.h1->tp_sec = tv.tv_sec;
1834 h.h1->tp_usec = tv.tv_usec;
1835 hdrlen = sizeof(*h.h1);
1836 break;
1837 case TPACKET_V2:
1838 h.h2->tp_len = skb->len;
1839 h.h2->tp_snaplen = snaplen;
1840 h.h2->tp_mac = macoff;
1841 h.h2->tp_net = netoff;
1842 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1843 && shhwtstamps->syststamp.tv64)
1844 ts = ktime_to_timespec(shhwtstamps->syststamp);
1845 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1846 && shhwtstamps->hwtstamp.tv64)
1847 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1848 else if (skb->tstamp.tv64)
1849 ts = ktime_to_timespec(skb->tstamp);
1850 else
1851 getnstimeofday(&ts);
1852 h.h2->tp_sec = ts.tv_sec;
1853 h.h2->tp_nsec = ts.tv_nsec;
1854 if (vlan_tx_tag_present(skb)) {
1855 h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1856 status |= TP_STATUS_VLAN_VALID;
1857 } else {
1858 h.h2->tp_vlan_tci = 0;
1859 }
1860 h.h2->tp_padding = 0;
1861 hdrlen = sizeof(*h.h2);
1862 break;
1863 case TPACKET_V3:
1864 /* tp_nxt_offset,vlan are already populated above.
1865 * So DONT clear those fields here
1866 */
1867 h.h3->tp_status |= status;
1868 h.h3->tp_len = skb->len;
1869 h.h3->tp_snaplen = snaplen;
1870 h.h3->tp_mac = macoff;
1871 h.h3->tp_net = netoff;
1872 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1873 && shhwtstamps->syststamp.tv64)
1874 ts = ktime_to_timespec(shhwtstamps->syststamp);
1875 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1876 && shhwtstamps->hwtstamp.tv64)
1877 ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1878 else if (skb->tstamp.tv64)
1879 ts = ktime_to_timespec(skb->tstamp);
1880 else
1881 getnstimeofday(&ts);
1882 h.h3->tp_sec = ts.tv_sec;
1883 h.h3->tp_nsec = ts.tv_nsec;
1884 hdrlen = sizeof(*h.h3);
1885 break;
1886 default:
1887 BUG();
1888 }
1889
1890 sll = h.raw + TPACKET_ALIGN(hdrlen);
1891 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1892 sll->sll_family = AF_PACKET;
1893 sll->sll_hatype = dev->type;
1894 sll->sll_protocol = skb->protocol;
1895 sll->sll_pkttype = skb->pkt_type;
1896 if (unlikely(po->origdev))
1897 sll->sll_ifindex = orig_dev->ifindex;
1898 else
1899 sll->sll_ifindex = dev->ifindex;
1900
1901 smp_mb();
1902 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1903 {
1904 u8 *start, *end;
1905
1906 if (po->tp_version <= TPACKET_V2) {
1907 end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1908 + macoff + snaplen);
1909 for (start = h.raw; start < end; start += PAGE_SIZE)
1910 flush_dcache_page(pgv_to_page(start));
1911 }
1912 smp_wmb();
1913 }
1914 #endif
1915 if (po->tp_version <= TPACKET_V2)
1916 __packet_set_status(po, h.raw, status);
1917 else
1918 prb_clear_blk_fill_status(&po->rx_ring);
1919
1920 sk->sk_data_ready(sk, 0);
1921
1922 drop_n_restore:
1923 if (skb_head != skb->data && skb_shared(skb)) {
1924 skb->data = skb_head;
1925 skb->len = skb_len;
1926 }
1927 drop:
1928 kfree_skb(skb);
1929 return 0;
1930
1931 ring_is_full:
1932 po->stats.tp_drops++;
1933 spin_unlock(&sk->sk_receive_queue.lock);
1934
1935 sk->sk_data_ready(sk, 0);
1936 kfree_skb(copy_skb);
1937 goto drop_n_restore;
1938 }
1939
1940 static void tpacket_destruct_skb(struct sk_buff *skb)
1941 {
1942 struct packet_sock *po = pkt_sk(skb->sk);
1943 void *ph;
1944
1945 if (likely(po->tx_ring.pg_vec)) {
1946 ph = skb_shinfo(skb)->destructor_arg;
1947 BUG_ON(__packet_get_status(po, ph) != TP_STATUS_SENDING);
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;
3229 struct sock *sk = sock->sk;
3230 struct packet_sock *po = pkt_sk(sk);
3231 void *data;
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 if (po->tp_version == TPACKET_V3) {
3247 len = sizeof(struct tpacket_stats_v3);
3248 } else {
3249 if (len > sizeof(struct tpacket_stats))
3250 len = sizeof(struct tpacket_stats);
3251 }
3252 spin_lock_bh(&sk->sk_receive_queue.lock);
3253 if (po->tp_version == TPACKET_V3) {
3254 memcpy(&st_u.stats3, &po->stats,
3255 sizeof(struct tpacket_stats));
3256 st_u.stats3.tp_freeze_q_cnt =
3257 po->stats_u.stats3.tp_freeze_q_cnt;
3258 st_u.stats3.tp_packets += po->stats.tp_drops;
3259 data = &st_u.stats3;
3260 } else {
3261 st = po->stats;
3262 st.tp_packets += st.tp_drops;
3263 data = &st;
3264 }
3265 memset(&po->stats, 0, sizeof(st));
3266 spin_unlock_bh(&sk->sk_receive_queue.lock);
3267 break;
3268 case PACKET_AUXDATA:
3269 if (len > sizeof(int))
3270 len = sizeof(int);
3271 val = po->auxdata;
3272
3273 data = &val;
3274 break;
3275 case PACKET_ORIGDEV:
3276 if (len > sizeof(int))
3277 len = sizeof(int);
3278 val = po->origdev;
3279
3280 data = &val;
3281 break;
3282 case PACKET_VNET_HDR:
3283 if (len > sizeof(int))
3284 len = sizeof(int);
3285 val = po->has_vnet_hdr;
3286
3287 data = &val;
3288 break;
3289 case PACKET_VERSION:
3290 if (len > sizeof(int))
3291 len = sizeof(int);
3292 val = po->tp_version;
3293 data = &val;
3294 break;
3295 case PACKET_HDRLEN:
3296 if (len > sizeof(int))
3297 len = sizeof(int);
3298 if (copy_from_user(&val, optval, len))
3299 return -EFAULT;
3300 switch (val) {
3301 case TPACKET_V1:
3302 val = sizeof(struct tpacket_hdr);
3303 break;
3304 case TPACKET_V2:
3305 val = sizeof(struct tpacket2_hdr);
3306 break;
3307 case TPACKET_V3:
3308 val = sizeof(struct tpacket3_hdr);
3309 break;
3310 default:
3311 return -EINVAL;
3312 }
3313 data = &val;
3314 break;
3315 case PACKET_RESERVE:
3316 if (len > sizeof(unsigned int))
3317 len = sizeof(unsigned int);
3318 val = po->tp_reserve;
3319 data = &val;
3320 break;
3321 case PACKET_LOSS:
3322 if (len > sizeof(unsigned int))
3323 len = sizeof(unsigned int);
3324 val = po->tp_loss;
3325 data = &val;
3326 break;
3327 case PACKET_TIMESTAMP:
3328 if (len > sizeof(int))
3329 len = sizeof(int);
3330 val = po->tp_tstamp;
3331 data = &val;
3332 break;
3333 case PACKET_FANOUT:
3334 if (len > sizeof(int))
3335 len = sizeof(int);
3336 val = (po->fanout ?
3337 ((u32)po->fanout->id |
3338 ((u32)po->fanout->type << 16)) :
3339 0);
3340 data = &val;
3341 break;
3342 default:
3343 return -ENOPROTOOPT;
3344 }
3345
3346 if (put_user(len, optlen))
3347 return -EFAULT;
3348 if (copy_to_user(optval, data, len))
3349 return -EFAULT;
3350 return 0;
3351 }
3352
3353
3354 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3355 {
3356 struct sock *sk;
3357 struct hlist_node *node;
3358 struct net_device *dev = data;
3359 struct net *net = dev_net(dev);
3360
3361 rcu_read_lock();
3362 sk_for_each_rcu(sk, node, &net->packet.sklist) {
3363 struct packet_sock *po = pkt_sk(sk);
3364
3365 switch (msg) {
3366 case NETDEV_UNREGISTER:
3367 if (po->mclist)
3368 packet_dev_mclist(dev, po->mclist, -1);
3369 /* fallthrough */
3370
3371 case NETDEV_DOWN:
3372 if (dev->ifindex == po->ifindex) {
3373 spin_lock(&po->bind_lock);
3374 if (po->running) {
3375 __unregister_prot_hook(sk, false);
3376 sk->sk_err = ENETDOWN;
3377 if (!sock_flag(sk, SOCK_DEAD))
3378 sk->sk_error_report(sk);
3379 }
3380 if (msg == NETDEV_UNREGISTER) {
3381 po->ifindex = -1;
3382 if (po->prot_hook.dev)
3383 dev_put(po->prot_hook.dev);
3384 po->prot_hook.dev = NULL;
3385 }
3386 spin_unlock(&po->bind_lock);
3387 }
3388 break;
3389 case NETDEV_UP:
3390 if (dev->ifindex == po->ifindex) {
3391 spin_lock(&po->bind_lock);
3392 if (po->num)
3393 register_prot_hook(sk);
3394 spin_unlock(&po->bind_lock);
3395 }
3396 break;
3397 }
3398 }
3399 rcu_read_unlock();
3400 return NOTIFY_DONE;
3401 }
3402
3403
3404 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3405 unsigned long arg)
3406 {
3407 struct sock *sk = sock->sk;
3408
3409 switch (cmd) {
3410 case SIOCOUTQ:
3411 {
3412 int amount = sk_wmem_alloc_get(sk);
3413
3414 return put_user(amount, (int __user *)arg);
3415 }
3416 case SIOCINQ:
3417 {
3418 struct sk_buff *skb;
3419 int amount = 0;
3420
3421 spin_lock_bh(&sk->sk_receive_queue.lock);
3422 skb = skb_peek(&sk->sk_receive_queue);
3423 if (skb)
3424 amount = skb->len;
3425 spin_unlock_bh(&sk->sk_receive_queue.lock);
3426 return put_user(amount, (int __user *)arg);
3427 }
3428 case SIOCGSTAMP:
3429 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3430 case SIOCGSTAMPNS:
3431 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3432
3433 #ifdef CONFIG_INET
3434 case SIOCADDRT:
3435 case SIOCDELRT:
3436 case SIOCDARP:
3437 case SIOCGARP:
3438 case SIOCSARP:
3439 case SIOCGIFADDR:
3440 case SIOCSIFADDR:
3441 case SIOCGIFBRDADDR:
3442 case SIOCSIFBRDADDR:
3443 case SIOCGIFNETMASK:
3444 case SIOCSIFNETMASK:
3445 case SIOCGIFDSTADDR:
3446 case SIOCSIFDSTADDR:
3447 case SIOCSIFFLAGS:
3448 return inet_dgram_ops.ioctl(sock, cmd, arg);
3449 #endif
3450
3451 default:
3452 return -ENOIOCTLCMD;
3453 }
3454 return 0;
3455 }
3456
3457 static unsigned int packet_poll(struct file *file, struct socket *sock,
3458 poll_table *wait)
3459 {
3460 struct sock *sk = sock->sk;
3461 struct packet_sock *po = pkt_sk(sk);
3462 unsigned int mask = datagram_poll(file, sock, wait);
3463
3464 spin_lock_bh(&sk->sk_receive_queue.lock);
3465 if (po->rx_ring.pg_vec) {
3466 if (!packet_previous_rx_frame(po, &po->rx_ring,
3467 TP_STATUS_KERNEL))
3468 mask |= POLLIN | POLLRDNORM;
3469 }
3470 spin_unlock_bh(&sk->sk_receive_queue.lock);
3471 spin_lock_bh(&sk->sk_write_queue.lock);
3472 if (po->tx_ring.pg_vec) {
3473 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3474 mask |= POLLOUT | POLLWRNORM;
3475 }
3476 spin_unlock_bh(&sk->sk_write_queue.lock);
3477 return mask;
3478 }
3479
3480
3481 /* Dirty? Well, I still did not learn better way to account
3482 * for user mmaps.
3483 */
3484
3485 static void packet_mm_open(struct vm_area_struct *vma)
3486 {
3487 struct file *file = vma->vm_file;
3488 struct socket *sock = file->private_data;
3489 struct sock *sk = sock->sk;
3490
3491 if (sk)
3492 atomic_inc(&pkt_sk(sk)->mapped);
3493 }
3494
3495 static void packet_mm_close(struct vm_area_struct *vma)
3496 {
3497 struct file *file = vma->vm_file;
3498 struct socket *sock = file->private_data;
3499 struct sock *sk = sock->sk;
3500
3501 if (sk)
3502 atomic_dec(&pkt_sk(sk)->mapped);
3503 }
3504
3505 static const struct vm_operations_struct packet_mmap_ops = {
3506 .open = packet_mm_open,
3507 .close = packet_mm_close,
3508 };
3509
3510 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3511 unsigned int len)
3512 {
3513 int i;
3514
3515 for (i = 0; i < len; i++) {
3516 if (likely(pg_vec[i].buffer)) {
3517 if (is_vmalloc_addr(pg_vec[i].buffer))
3518 vfree(pg_vec[i].buffer);
3519 else
3520 free_pages((unsigned long)pg_vec[i].buffer,
3521 order);
3522 pg_vec[i].buffer = NULL;
3523 }
3524 }
3525 kfree(pg_vec);
3526 }
3527
3528 static char *alloc_one_pg_vec_page(unsigned long order)
3529 {
3530 char *buffer = NULL;
3531 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3532 __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3533
3534 buffer = (char *) __get_free_pages(gfp_flags, order);
3535
3536 if (buffer)
3537 return buffer;
3538
3539 /*
3540 * __get_free_pages failed, fall back to vmalloc
3541 */
3542 buffer = vzalloc((1 << order) * PAGE_SIZE);
3543
3544 if (buffer)
3545 return buffer;
3546
3547 /*
3548 * vmalloc failed, lets dig into swap here
3549 */
3550 gfp_flags &= ~__GFP_NORETRY;
3551 buffer = (char *)__get_free_pages(gfp_flags, order);
3552 if (buffer)
3553 return buffer;
3554
3555 /*
3556 * complete and utter failure
3557 */
3558 return NULL;
3559 }
3560
3561 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3562 {
3563 unsigned int block_nr = req->tp_block_nr;
3564 struct pgv *pg_vec;
3565 int i;
3566
3567 pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3568 if (unlikely(!pg_vec))
3569 goto out;
3570
3571 for (i = 0; i < block_nr; i++) {
3572 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3573 if (unlikely(!pg_vec[i].buffer))
3574 goto out_free_pgvec;
3575 }
3576
3577 out:
3578 return pg_vec;
3579
3580 out_free_pgvec:
3581 free_pg_vec(pg_vec, order, block_nr);
3582 pg_vec = NULL;
3583 goto out;
3584 }
3585
3586 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3587 int closing, int tx_ring)
3588 {
3589 struct pgv *pg_vec = NULL;
3590 struct packet_sock *po = pkt_sk(sk);
3591 int was_running, order = 0;
3592 struct packet_ring_buffer *rb;
3593 struct sk_buff_head *rb_queue;
3594 __be16 num;
3595 int err = -EINVAL;
3596 /* Added to avoid minimal code churn */
3597 struct tpacket_req *req = &req_u->req;
3598
3599 /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3600 if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3601 WARN(1, "Tx-ring is not supported.\n");
3602 goto out;
3603 }
3604
3605 rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3606 rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3607
3608 err = -EBUSY;
3609 if (!closing) {
3610 if (atomic_read(&po->mapped))
3611 goto out;
3612 if (atomic_read(&rb->pending))
3613 goto out;
3614 }
3615
3616 if (req->tp_block_nr) {
3617 /* Sanity tests and some calculations */
3618 err = -EBUSY;
3619 if (unlikely(rb->pg_vec))
3620 goto out;
3621
3622 switch (po->tp_version) {
3623 case TPACKET_V1:
3624 po->tp_hdrlen = TPACKET_HDRLEN;
3625 break;
3626 case TPACKET_V2:
3627 po->tp_hdrlen = TPACKET2_HDRLEN;
3628 break;
3629 case TPACKET_V3:
3630 po->tp_hdrlen = TPACKET3_HDRLEN;
3631 break;
3632 }
3633
3634 err = -EINVAL;
3635 if (unlikely((int)req->tp_block_size <= 0))
3636 goto out;
3637 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3638 goto out;
3639 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3640 po->tp_reserve))
3641 goto out;
3642 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3643 goto out;
3644
3645 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3646 if (unlikely(rb->frames_per_block <= 0))
3647 goto out;
3648 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3649 req->tp_frame_nr))
3650 goto out;
3651
3652 err = -ENOMEM;
3653 order = get_order(req->tp_block_size);
3654 pg_vec = alloc_pg_vec(req, order);
3655 if (unlikely(!pg_vec))
3656 goto out;
3657 switch (po->tp_version) {
3658 case TPACKET_V3:
3659 /* Transmit path is not supported. We checked
3660 * it above but just being paranoid
3661 */
3662 if (!tx_ring)
3663 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3664 break;
3665 default:
3666 break;
3667 }
3668 }
3669 /* Done */
3670 else {
3671 err = -EINVAL;
3672 if (unlikely(req->tp_frame_nr))
3673 goto out;
3674 }
3675
3676 lock_sock(sk);
3677
3678 /* Detach socket from network */
3679 spin_lock(&po->bind_lock);
3680 was_running = po->running;
3681 num = po->num;
3682 if (was_running) {
3683 po->num = 0;
3684 __unregister_prot_hook(sk, false);
3685 }
3686 spin_unlock(&po->bind_lock);
3687
3688 synchronize_net();
3689
3690 err = -EBUSY;
3691 mutex_lock(&po->pg_vec_lock);
3692 if (closing || atomic_read(&po->mapped) == 0) {
3693 err = 0;
3694 spin_lock_bh(&rb_queue->lock);
3695 swap(rb->pg_vec, pg_vec);
3696 rb->frame_max = (req->tp_frame_nr - 1);
3697 rb->head = 0;
3698 rb->frame_size = req->tp_frame_size;
3699 spin_unlock_bh(&rb_queue->lock);
3700
3701 swap(rb->pg_vec_order, order);
3702 swap(rb->pg_vec_len, req->tp_block_nr);
3703
3704 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3705 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3706 tpacket_rcv : packet_rcv;
3707 skb_queue_purge(rb_queue);
3708 if (atomic_read(&po->mapped))
3709 pr_err("packet_mmap: vma is busy: %d\n",
3710 atomic_read(&po->mapped));
3711 }
3712 mutex_unlock(&po->pg_vec_lock);
3713
3714 spin_lock(&po->bind_lock);
3715 if (was_running) {
3716 po->num = num;
3717 register_prot_hook(sk);
3718 }
3719 spin_unlock(&po->bind_lock);
3720 if (closing && (po->tp_version > TPACKET_V2)) {
3721 /* Because we don't support block-based V3 on tx-ring */
3722 if (!tx_ring)
3723 prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3724 }
3725 release_sock(sk);
3726
3727 if (pg_vec)
3728 free_pg_vec(pg_vec, order, req->tp_block_nr);
3729 out:
3730 return err;
3731 }
3732
3733 static int packet_mmap(struct file *file, struct socket *sock,
3734 struct vm_area_struct *vma)
3735 {
3736 struct sock *sk = sock->sk;
3737 struct packet_sock *po = pkt_sk(sk);
3738 unsigned long size, expected_size;
3739 struct packet_ring_buffer *rb;
3740 unsigned long start;
3741 int err = -EINVAL;
3742 int i;
3743
3744 if (vma->vm_pgoff)
3745 return -EINVAL;
3746
3747 mutex_lock(&po->pg_vec_lock);
3748
3749 expected_size = 0;
3750 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3751 if (rb->pg_vec) {
3752 expected_size += rb->pg_vec_len
3753 * rb->pg_vec_pages
3754 * PAGE_SIZE;
3755 }
3756 }
3757
3758 if (expected_size == 0)
3759 goto out;
3760
3761 size = vma->vm_end - vma->vm_start;
3762 if (size != expected_size)
3763 goto out;
3764
3765 start = vma->vm_start;
3766 for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3767 if (rb->pg_vec == NULL)
3768 continue;
3769
3770 for (i = 0; i < rb->pg_vec_len; i++) {
3771 struct page *page;
3772 void *kaddr = rb->pg_vec[i].buffer;
3773 int pg_num;
3774
3775 for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3776 page = pgv_to_page(kaddr);
3777 err = vm_insert_page(vma, start, page);
3778 if (unlikely(err))
3779 goto out;
3780 start += PAGE_SIZE;
3781 kaddr += PAGE_SIZE;
3782 }
3783 }
3784 }
3785
3786 atomic_inc(&po->mapped);
3787 vma->vm_ops = &packet_mmap_ops;
3788 err = 0;
3789
3790 out:
3791 mutex_unlock(&po->pg_vec_lock);
3792 return err;
3793 }
3794
3795 static const struct proto_ops packet_ops_spkt = {
3796 .family = PF_PACKET,
3797 .owner = THIS_MODULE,
3798 .release = packet_release,
3799 .bind = packet_bind_spkt,
3800 .connect = sock_no_connect,
3801 .socketpair = sock_no_socketpair,
3802 .accept = sock_no_accept,
3803 .getname = packet_getname_spkt,
3804 .poll = datagram_poll,
3805 .ioctl = packet_ioctl,
3806 .listen = sock_no_listen,
3807 .shutdown = sock_no_shutdown,
3808 .setsockopt = sock_no_setsockopt,
3809 .getsockopt = sock_no_getsockopt,
3810 .sendmsg = packet_sendmsg_spkt,
3811 .recvmsg = packet_recvmsg,
3812 .mmap = sock_no_mmap,
3813 .sendpage = sock_no_sendpage,
3814 };
3815
3816 static const struct proto_ops packet_ops = {
3817 .family = PF_PACKET,
3818 .owner = THIS_MODULE,
3819 .release = packet_release,
3820 .bind = packet_bind,
3821 .connect = sock_no_connect,
3822 .socketpair = sock_no_socketpair,
3823 .accept = sock_no_accept,
3824 .getname = packet_getname,
3825 .poll = packet_poll,
3826 .ioctl = packet_ioctl,
3827 .listen = sock_no_listen,
3828 .shutdown = sock_no_shutdown,
3829 .setsockopt = packet_setsockopt,
3830 .getsockopt = packet_getsockopt,
3831 .sendmsg = packet_sendmsg,
3832 .recvmsg = packet_recvmsg,
3833 .mmap = packet_mmap,
3834 .sendpage = sock_no_sendpage,
3835 };
3836
3837 static const struct net_proto_family packet_family_ops = {
3838 .family = PF_PACKET,
3839 .create = packet_create,
3840 .owner = THIS_MODULE,
3841 };
3842
3843 static struct notifier_block packet_netdev_notifier = {
3844 .notifier_call = packet_notifier,
3845 };
3846
3847 #ifdef CONFIG_PROC_FS
3848
3849 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3850 __acquires(RCU)
3851 {
3852 struct net *net = seq_file_net(seq);
3853
3854 rcu_read_lock();
3855 return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3856 }
3857
3858 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3859 {
3860 struct net *net = seq_file_net(seq);
3861 return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3862 }
3863
3864 static void packet_seq_stop(struct seq_file *seq, void *v)
3865 __releases(RCU)
3866 {
3867 rcu_read_unlock();
3868 }
3869
3870 static int packet_seq_show(struct seq_file *seq, void *v)
3871 {
3872 if (v == SEQ_START_TOKEN)
3873 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
3874 else {
3875 struct sock *s = sk_entry(v);
3876 const struct packet_sock *po = pkt_sk(s);
3877
3878 seq_printf(seq,
3879 "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
3880 s,
3881 atomic_read(&s->sk_refcnt),
3882 s->sk_type,
3883 ntohs(po->num),
3884 po->ifindex,
3885 po->running,
3886 atomic_read(&s->sk_rmem_alloc),
3887 sock_i_uid(s),
3888 sock_i_ino(s));
3889 }
3890
3891 return 0;
3892 }
3893
3894 static const struct seq_operations packet_seq_ops = {
3895 .start = packet_seq_start,
3896 .next = packet_seq_next,
3897 .stop = packet_seq_stop,
3898 .show = packet_seq_show,
3899 };
3900
3901 static int packet_seq_open(struct inode *inode, struct file *file)
3902 {
3903 return seq_open_net(inode, file, &packet_seq_ops,
3904 sizeof(struct seq_net_private));
3905 }
3906
3907 static const struct file_operations packet_seq_fops = {
3908 .owner = THIS_MODULE,
3909 .open = packet_seq_open,
3910 .read = seq_read,
3911 .llseek = seq_lseek,
3912 .release = seq_release_net,
3913 };
3914
3915 #endif
3916
3917 static int __net_init packet_net_init(struct net *net)
3918 {
3919 spin_lock_init(&net->packet.sklist_lock);
3920 INIT_HLIST_HEAD(&net->packet.sklist);
3921
3922 if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
3923 return -ENOMEM;
3924
3925 return 0;
3926 }
3927
3928 static void __net_exit packet_net_exit(struct net *net)
3929 {
3930 proc_net_remove(net, "packet");
3931 }
3932
3933 static struct pernet_operations packet_net_ops = {
3934 .init = packet_net_init,
3935 .exit = packet_net_exit,
3936 };
3937
3938
3939 static void __exit packet_exit(void)
3940 {
3941 unregister_netdevice_notifier(&packet_netdev_notifier);
3942 unregister_pernet_subsys(&packet_net_ops);
3943 sock_unregister(PF_PACKET);
3944 proto_unregister(&packet_proto);
3945 }
3946
3947 static int __init packet_init(void)
3948 {
3949 int rc = proto_register(&packet_proto, 0);
3950
3951 if (rc != 0)
3952 goto out;
3953
3954 sock_register(&packet_family_ops);
3955 register_pernet_subsys(&packet_net_ops);
3956 register_netdevice_notifier(&packet_netdev_notifier);
3957 out:
3958 return rc;
3959 }
3960
3961 module_init(packet_init);
3962 module_exit(packet_exit);
3963 MODULE_LICENSE("GPL");
3964 MODULE_ALIAS_NETPROTO(PF_PACKET);
Linux kernel - Deliverables
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