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[NET]: Wrap hard_header_parse
[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 * Version: $Id: af_packet.c,v 1.61 2002/02/08 03:57:19 davem Exp $
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 *
14 * Fixes:
15 * Alan Cox : verify_area() now used correctly
16 * Alan Cox : new skbuff lists, look ma no backlogs!
17 * Alan Cox : tidied skbuff lists.
18 * Alan Cox : Now uses generic datagram routines I
19 * added. Also fixed the peek/read crash
20 * from all old Linux datagram code.
21 * Alan Cox : Uses the improved datagram code.
22 * Alan Cox : Added NULL's for socket options.
23 * Alan Cox : Re-commented the code.
24 * Alan Cox : Use new kernel side addressing
25 * Rob Janssen : Correct MTU usage.
26 * Dave Platt : Counter leaks caused by incorrect
27 * interrupt locking and some slightly
28 * dubious gcc output. Can you read
29 * compiler: it said _VOLATILE_
30 * Richard Kooijman : Timestamp fixes.
31 * Alan Cox : New buffers. Use sk->mac.raw.
32 * Alan Cox : sendmsg/recvmsg support.
33 * Alan Cox : Protocol setting support
34 * Alexey Kuznetsov : Untied from IPv4 stack.
35 * Cyrus Durgin : Fixed kerneld for kmod.
36 * Michal Ostrowski : Module initialization cleanup.
37 * Ulises Alonso : Frame number limit removal and
38 * packet_set_ring memory leak.
39 * Eric Biederman : Allow for > 8 byte hardware addresses.
40 * The convention is that longer addresses
41 * will simply extend the hardware address
42 * byte arrays at the end of sockaddr_ll
43 * and packet_mreq.
44 *
45 * This program is free software; you can redistribute it and/or
46 * modify it under the terms of the GNU General Public License
47 * as published by the Free Software Foundation; either version
48 * 2 of the License, or (at your option) any later version.
49 *
50 */
51
52 #include <linux/types.h>
53 #include <linux/mm.h>
54 #include <linux/capability.h>
55 #include <linux/fcntl.h>
56 #include <linux/socket.h>
57 #include <linux/in.h>
58 #include <linux/inet.h>
59 #include <linux/netdevice.h>
60 #include <linux/if_packet.h>
61 #include <linux/wireless.h>
62 #include <linux/kernel.h>
63 #include <linux/kmod.h>
64 #include <net/net_namespace.h>
65 #include <net/ip.h>
66 #include <net/protocol.h>
67 #include <linux/skbuff.h>
68 #include <net/sock.h>
69 #include <linux/errno.h>
70 #include <linux/timer.h>
71 #include <asm/system.h>
72 #include <asm/uaccess.h>
73 #include <asm/ioctls.h>
74 #include <asm/page.h>
75 #include <asm/cacheflush.h>
76 #include <asm/io.h>
77 #include <linux/proc_fs.h>
78 #include <linux/seq_file.h>
79 #include <linux/poll.h>
80 #include <linux/module.h>
81 #include <linux/init.h>
82
83 #ifdef CONFIG_INET
84 #include <net/inet_common.h>
85 #endif
86
87 /*
88 Assumptions:
89 - if device has no dev->hard_header routine, it adds and removes ll header
90 inside itself. In this case ll header is invisible outside of device,
91 but higher levels still should reserve dev->hard_header_len.
92 Some devices are enough clever to reallocate skb, when header
93 will not fit to reserved space (tunnel), another ones are silly
94 (PPP).
95 - packet socket receives packets with pulled ll header,
96 so that SOCK_RAW should push it back.
97
98 On receive:
99 -----------
100
101 Incoming, dev->hard_header!=NULL
102 mac_header -> ll header
103 data -> data
104
105 Outgoing, dev->hard_header!=NULL
106 mac_header -> ll header
107 data -> ll header
108
109 Incoming, dev->hard_header==NULL
110 mac_header -> UNKNOWN position. It is very likely, that it points to ll
111 header. PPP makes it, that is wrong, because introduce
112 assymetry between rx and tx paths.
113 data -> data
114
115 Outgoing, dev->hard_header==NULL
116 mac_header -> data. ll header is still not built!
117 data -> data
118
119 Resume
120 If dev->hard_header==NULL we are unlikely to restore sensible ll header.
121
122
123 On transmit:
124 ------------
125
126 dev->hard_header != NULL
127 mac_header -> ll header
128 data -> ll header
129
130 dev->hard_header == NULL (ll header is added by device, we cannot control it)
131 mac_header -> data
132 data -> data
133
134 We should set nh.raw on output to correct posistion,
135 packet classifier depends on it.
136 */
137
138 /* List of all packet sockets. */
139 static HLIST_HEAD(packet_sklist);
140 static DEFINE_RWLOCK(packet_sklist_lock);
141
142 static atomic_t packet_socks_nr;
143
144
145 /* Private packet socket structures. */
146
147 struct packet_mclist
148 {
149 struct packet_mclist *next;
150 int ifindex;
151 int count;
152 unsigned short type;
153 unsigned short alen;
154 unsigned char addr[MAX_ADDR_LEN];
155 };
156 /* identical to struct packet_mreq except it has
157 * a longer address field.
158 */
159 struct packet_mreq_max
160 {
161 int mr_ifindex;
162 unsigned short mr_type;
163 unsigned short mr_alen;
164 unsigned char mr_address[MAX_ADDR_LEN];
165 };
166
167 #ifdef CONFIG_PACKET_MMAP
168 static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing);
169 #endif
170
171 static void packet_flush_mclist(struct sock *sk);
172
173 struct packet_sock {
174 /* struct sock has to be the first member of packet_sock */
175 struct sock sk;
176 struct tpacket_stats stats;
177 #ifdef CONFIG_PACKET_MMAP
178 char * *pg_vec;
179 unsigned int head;
180 unsigned int frames_per_block;
181 unsigned int frame_size;
182 unsigned int frame_max;
183 int copy_thresh;
184 #endif
185 struct packet_type prot_hook;
186 spinlock_t bind_lock;
187 unsigned int running:1, /* prot_hook is attached*/
188 auxdata:1,
189 origdev:1;
190 int ifindex; /* bound device */
191 __be16 num;
192 struct packet_mclist *mclist;
193 #ifdef CONFIG_PACKET_MMAP
194 atomic_t mapped;
195 unsigned int pg_vec_order;
196 unsigned int pg_vec_pages;
197 unsigned int pg_vec_len;
198 #endif
199 };
200
201 struct packet_skb_cb {
202 unsigned int origlen;
203 union {
204 struct sockaddr_pkt pkt;
205 struct sockaddr_ll ll;
206 } sa;
207 };
208
209 #define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
210
211 #ifdef CONFIG_PACKET_MMAP
212
213 static inline struct tpacket_hdr *packet_lookup_frame(struct packet_sock *po, unsigned int position)
214 {
215 unsigned int pg_vec_pos, frame_offset;
216
217 pg_vec_pos = position / po->frames_per_block;
218 frame_offset = position % po->frames_per_block;
219
220 return (struct tpacket_hdr *)(po->pg_vec[pg_vec_pos] + (frame_offset * po->frame_size));
221 }
222 #endif
223
224 static inline struct packet_sock *pkt_sk(struct sock *sk)
225 {
226 return (struct packet_sock *)sk;
227 }
228
229 static void packet_sock_destruct(struct sock *sk)
230 {
231 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
232 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
233
234 if (!sock_flag(sk, SOCK_DEAD)) {
235 printk("Attempt to release alive packet socket: %p\n", sk);
236 return;
237 }
238
239 atomic_dec(&packet_socks_nr);
240 #ifdef PACKET_REFCNT_DEBUG
241 printk(KERN_DEBUG "PACKET socket %p is free, %d are alive\n", sk, atomic_read(&packet_socks_nr));
242 #endif
243 }
244
245
246 static const struct proto_ops packet_ops;
247
248 static const struct proto_ops packet_ops_spkt;
249
250 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
251 {
252 struct sock *sk;
253 struct sockaddr_pkt *spkt;
254
255 if (dev->nd_net != &init_net)
256 goto out;
257
258 /*
259 * When we registered the protocol we saved the socket in the data
260 * field for just this event.
261 */
262
263 sk = pt->af_packet_priv;
264
265 /*
266 * Yank back the headers [hope the device set this
267 * right or kerboom...]
268 *
269 * Incoming packets have ll header pulled,
270 * push it back.
271 *
272 * For outgoing ones skb->data == skb_mac_header(skb)
273 * so that this procedure is noop.
274 */
275
276 if (skb->pkt_type == PACKET_LOOPBACK)
277 goto out;
278
279 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
280 goto oom;
281
282 /* drop any routing info */
283 dst_release(skb->dst);
284 skb->dst = NULL;
285
286 /* drop conntrack reference */
287 nf_reset(skb);
288
289 spkt = &PACKET_SKB_CB(skb)->sa.pkt;
290
291 skb_push(skb, skb->data - skb_mac_header(skb));
292
293 /*
294 * The SOCK_PACKET socket receives _all_ frames.
295 */
296
297 spkt->spkt_family = dev->type;
298 strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
299 spkt->spkt_protocol = skb->protocol;
300
301 /*
302 * Charge the memory to the socket. This is done specifically
303 * to prevent sockets using all the memory up.
304 */
305
306 if (sock_queue_rcv_skb(sk,skb) == 0)
307 return 0;
308
309 out:
310 kfree_skb(skb);
311 oom:
312 return 0;
313 }
314
315
316 /*
317 * Output a raw packet to a device layer. This bypasses all the other
318 * protocol layers and you must therefore supply it with a complete frame
319 */
320
321 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
322 struct msghdr *msg, size_t len)
323 {
324 struct sock *sk = sock->sk;
325 struct sockaddr_pkt *saddr=(struct sockaddr_pkt *)msg->msg_name;
326 struct sk_buff *skb;
327 struct net_device *dev;
328 __be16 proto=0;
329 int err;
330
331 /*
332 * Get and verify the address.
333 */
334
335 if (saddr)
336 {
337 if (msg->msg_namelen < sizeof(struct sockaddr))
338 return(-EINVAL);
339 if (msg->msg_namelen==sizeof(struct sockaddr_pkt))
340 proto=saddr->spkt_protocol;
341 }
342 else
343 return(-ENOTCONN); /* SOCK_PACKET must be sent giving an address */
344
345 /*
346 * Find the device first to size check it
347 */
348
349 saddr->spkt_device[13] = 0;
350 dev = dev_get_by_name(&init_net, saddr->spkt_device);
351 err = -ENODEV;
352 if (dev == NULL)
353 goto out_unlock;
354
355 err = -ENETDOWN;
356 if (!(dev->flags & IFF_UP))
357 goto out_unlock;
358
359 /*
360 * You may not queue a frame bigger than the mtu. This is the lowest level
361 * raw protocol and you must do your own fragmentation at this level.
362 */
363
364 err = -EMSGSIZE;
365 if (len > dev->mtu + dev->hard_header_len)
366 goto out_unlock;
367
368 err = -ENOBUFS;
369 skb = sock_wmalloc(sk, len + LL_RESERVED_SPACE(dev), 0, GFP_KERNEL);
370
371 /*
372 * If the write buffer is full, then tough. At this level the user gets to
373 * deal with the problem - do your own algorithmic backoffs. That's far
374 * more flexible.
375 */
376
377 if (skb == NULL)
378 goto out_unlock;
379
380 /*
381 * Fill it in
382 */
383
384 /* FIXME: Save some space for broken drivers that write a
385 * hard header at transmission time by themselves. PPP is the
386 * notable one here. This should really be fixed at the driver level.
387 */
388 skb_reserve(skb, LL_RESERVED_SPACE(dev));
389 skb_reset_network_header(skb);
390
391 /* Try to align data part correctly */
392 if (dev->hard_header) {
393 skb->data -= dev->hard_header_len;
394 skb->tail -= dev->hard_header_len;
395 if (len < dev->hard_header_len)
396 skb_reset_network_header(skb);
397 }
398
399 /* Returns -EFAULT on error */
400 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
401 skb->protocol = proto;
402 skb->dev = dev;
403 skb->priority = sk->sk_priority;
404 if (err)
405 goto out_free;
406
407 /*
408 * Now send it
409 */
410
411 dev_queue_xmit(skb);
412 dev_put(dev);
413 return(len);
414
415 out_free:
416 kfree_skb(skb);
417 out_unlock:
418 if (dev)
419 dev_put(dev);
420 return err;
421 }
422
423 static inline unsigned int run_filter(struct sk_buff *skb, struct sock *sk,
424 unsigned int res)
425 {
426 struct sk_filter *filter;
427
428 rcu_read_lock_bh();
429 filter = rcu_dereference(sk->sk_filter);
430 if (filter != NULL)
431 res = sk_run_filter(skb, filter->insns, filter->len);
432 rcu_read_unlock_bh();
433
434 return res;
435 }
436
437 /*
438 This function makes lazy skb cloning in hope that most of packets
439 are discarded by BPF.
440
441 Note tricky part: we DO mangle shared skb! skb->data, skb->len
442 and skb->cb are mangled. It works because (and until) packets
443 falling here are owned by current CPU. Output packets are cloned
444 by dev_queue_xmit_nit(), input packets are processed by net_bh
445 sequencially, so that if we return skb to original state on exit,
446 we will not harm anyone.
447 */
448
449 static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
450 {
451 struct sock *sk;
452 struct sockaddr_ll *sll;
453 struct packet_sock *po;
454 u8 * skb_head = skb->data;
455 int skb_len = skb->len;
456 unsigned int snaplen, res;
457
458 if (dev->nd_net != &init_net)
459 goto drop;
460
461 if (skb->pkt_type == PACKET_LOOPBACK)
462 goto drop;
463
464 sk = pt->af_packet_priv;
465 po = pkt_sk(sk);
466
467 skb->dev = dev;
468
469 if (dev->hard_header) {
470 /* The device has an explicit notion of ll header,
471 exported to higher levels.
472
473 Otherwise, the device hides datails of it frame
474 structure, so that corresponding packet head
475 never delivered to user.
476 */
477 if (sk->sk_type != SOCK_DGRAM)
478 skb_push(skb, skb->data - skb_mac_header(skb));
479 else if (skb->pkt_type == PACKET_OUTGOING) {
480 /* Special case: outgoing packets have ll header at head */
481 skb_pull(skb, skb_network_offset(skb));
482 }
483 }
484
485 snaplen = skb->len;
486
487 res = run_filter(skb, sk, snaplen);
488 if (!res)
489 goto drop_n_restore;
490 if (snaplen > res)
491 snaplen = res;
492
493 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
494 (unsigned)sk->sk_rcvbuf)
495 goto drop_n_acct;
496
497 if (skb_shared(skb)) {
498 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
499 if (nskb == NULL)
500 goto drop_n_acct;
501
502 if (skb_head != skb->data) {
503 skb->data = skb_head;
504 skb->len = skb_len;
505 }
506 kfree_skb(skb);
507 skb = nskb;
508 }
509
510 BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
511 sizeof(skb->cb));
512
513 sll = &PACKET_SKB_CB(skb)->sa.ll;
514 sll->sll_family = AF_PACKET;
515 sll->sll_hatype = dev->type;
516 sll->sll_protocol = skb->protocol;
517 sll->sll_pkttype = skb->pkt_type;
518 if (unlikely(po->origdev) && skb->pkt_type == PACKET_HOST)
519 sll->sll_ifindex = orig_dev->ifindex;
520 else
521 sll->sll_ifindex = dev->ifindex;
522
523 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
524
525 PACKET_SKB_CB(skb)->origlen = skb->len;
526
527 if (pskb_trim(skb, snaplen))
528 goto drop_n_acct;
529
530 skb_set_owner_r(skb, sk);
531 skb->dev = NULL;
532 dst_release(skb->dst);
533 skb->dst = NULL;
534
535 /* drop conntrack reference */
536 nf_reset(skb);
537
538 spin_lock(&sk->sk_receive_queue.lock);
539 po->stats.tp_packets++;
540 __skb_queue_tail(&sk->sk_receive_queue, skb);
541 spin_unlock(&sk->sk_receive_queue.lock);
542 sk->sk_data_ready(sk, skb->len);
543 return 0;
544
545 drop_n_acct:
546 spin_lock(&sk->sk_receive_queue.lock);
547 po->stats.tp_drops++;
548 spin_unlock(&sk->sk_receive_queue.lock);
549
550 drop_n_restore:
551 if (skb_head != skb->data && skb_shared(skb)) {
552 skb->data = skb_head;
553 skb->len = skb_len;
554 }
555 drop:
556 kfree_skb(skb);
557 return 0;
558 }
559
560 #ifdef CONFIG_PACKET_MMAP
561 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
562 {
563 struct sock *sk;
564 struct packet_sock *po;
565 struct sockaddr_ll *sll;
566 struct tpacket_hdr *h;
567 u8 * skb_head = skb->data;
568 int skb_len = skb->len;
569 unsigned int snaplen, res;
570 unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER;
571 unsigned short macoff, netoff;
572 struct sk_buff *copy_skb = NULL;
573 struct timeval tv;
574
575 if (dev->nd_net != &init_net)
576 goto drop;
577
578 if (skb->pkt_type == PACKET_LOOPBACK)
579 goto drop;
580
581 sk = pt->af_packet_priv;
582 po = pkt_sk(sk);
583
584 if (dev->hard_header) {
585 if (sk->sk_type != SOCK_DGRAM)
586 skb_push(skb, skb->data - skb_mac_header(skb));
587 else if (skb->pkt_type == PACKET_OUTGOING) {
588 /* Special case: outgoing packets have ll header at head */
589 skb_pull(skb, skb_network_offset(skb));
590 }
591 }
592
593 if (skb->ip_summed == CHECKSUM_PARTIAL)
594 status |= TP_STATUS_CSUMNOTREADY;
595
596 snaplen = skb->len;
597
598 res = run_filter(skb, sk, snaplen);
599 if (!res)
600 goto drop_n_restore;
601 if (snaplen > res)
602 snaplen = res;
603
604 if (sk->sk_type == SOCK_DGRAM) {
605 macoff = netoff = TPACKET_ALIGN(TPACKET_HDRLEN) + 16;
606 } else {
607 unsigned maclen = skb_network_offset(skb);
608 netoff = TPACKET_ALIGN(TPACKET_HDRLEN + (maclen < 16 ? 16 : maclen));
609 macoff = netoff - maclen;
610 }
611
612 if (macoff + snaplen > po->frame_size) {
613 if (po->copy_thresh &&
614 atomic_read(&sk->sk_rmem_alloc) + skb->truesize <
615 (unsigned)sk->sk_rcvbuf) {
616 if (skb_shared(skb)) {
617 copy_skb = skb_clone(skb, GFP_ATOMIC);
618 } else {
619 copy_skb = skb_get(skb);
620 skb_head = skb->data;
621 }
622 if (copy_skb)
623 skb_set_owner_r(copy_skb, sk);
624 }
625 snaplen = po->frame_size - macoff;
626 if ((int)snaplen < 0)
627 snaplen = 0;
628 }
629
630 spin_lock(&sk->sk_receive_queue.lock);
631 h = packet_lookup_frame(po, po->head);
632
633 if (h->tp_status)
634 goto ring_is_full;
635 po->head = po->head != po->frame_max ? po->head+1 : 0;
636 po->stats.tp_packets++;
637 if (copy_skb) {
638 status |= TP_STATUS_COPY;
639 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
640 }
641 if (!po->stats.tp_drops)
642 status &= ~TP_STATUS_LOSING;
643 spin_unlock(&sk->sk_receive_queue.lock);
644
645 skb_copy_bits(skb, 0, (u8*)h + macoff, snaplen);
646
647 h->tp_len = skb->len;
648 h->tp_snaplen = snaplen;
649 h->tp_mac = macoff;
650 h->tp_net = netoff;
651 if (skb->tstamp.tv64)
652 tv = ktime_to_timeval(skb->tstamp);
653 else
654 do_gettimeofday(&tv);
655 h->tp_sec = tv.tv_sec;
656 h->tp_usec = tv.tv_usec;
657
658 sll = (struct sockaddr_ll*)((u8*)h + TPACKET_ALIGN(sizeof(*h)));
659 sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
660 sll->sll_family = AF_PACKET;
661 sll->sll_hatype = dev->type;
662 sll->sll_protocol = skb->protocol;
663 sll->sll_pkttype = skb->pkt_type;
664 if (unlikely(po->origdev) && skb->pkt_type == PACKET_HOST)
665 sll->sll_ifindex = orig_dev->ifindex;
666 else
667 sll->sll_ifindex = dev->ifindex;
668
669 h->tp_status = status;
670 smp_mb();
671
672 {
673 struct page *p_start, *p_end;
674 u8 *h_end = (u8 *)h + macoff + snaplen - 1;
675
676 p_start = virt_to_page(h);
677 p_end = virt_to_page(h_end);
678 while (p_start <= p_end) {
679 flush_dcache_page(p_start);
680 p_start++;
681 }
682 }
683
684 sk->sk_data_ready(sk, 0);
685
686 drop_n_restore:
687 if (skb_head != skb->data && skb_shared(skb)) {
688 skb->data = skb_head;
689 skb->len = skb_len;
690 }
691 drop:
692 kfree_skb(skb);
693 return 0;
694
695 ring_is_full:
696 po->stats.tp_drops++;
697 spin_unlock(&sk->sk_receive_queue.lock);
698
699 sk->sk_data_ready(sk, 0);
700 if (copy_skb)
701 kfree_skb(copy_skb);
702 goto drop_n_restore;
703 }
704
705 #endif
706
707
708 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
709 struct msghdr *msg, size_t len)
710 {
711 struct sock *sk = sock->sk;
712 struct sockaddr_ll *saddr=(struct sockaddr_ll *)msg->msg_name;
713 struct sk_buff *skb;
714 struct net_device *dev;
715 __be16 proto;
716 unsigned char *addr;
717 int ifindex, err, reserve = 0;
718
719 /*
720 * Get and verify the address.
721 */
722
723 if (saddr == NULL) {
724 struct packet_sock *po = pkt_sk(sk);
725
726 ifindex = po->ifindex;
727 proto = po->num;
728 addr = NULL;
729 } else {
730 err = -EINVAL;
731 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
732 goto out;
733 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
734 goto out;
735 ifindex = saddr->sll_ifindex;
736 proto = saddr->sll_protocol;
737 addr = saddr->sll_addr;
738 }
739
740
741 dev = dev_get_by_index(&init_net, ifindex);
742 err = -ENXIO;
743 if (dev == NULL)
744 goto out_unlock;
745 if (sock->type == SOCK_RAW)
746 reserve = dev->hard_header_len;
747
748 err = -ENETDOWN;
749 if (!(dev->flags & IFF_UP))
750 goto out_unlock;
751
752 err = -EMSGSIZE;
753 if (len > dev->mtu+reserve)
754 goto out_unlock;
755
756 skb = sock_alloc_send_skb(sk, len + LL_RESERVED_SPACE(dev),
757 msg->msg_flags & MSG_DONTWAIT, &err);
758 if (skb==NULL)
759 goto out_unlock;
760
761 skb_reserve(skb, LL_RESERVED_SPACE(dev));
762 skb_reset_network_header(skb);
763
764 err = -EINVAL;
765 if (sock->type == SOCK_DGRAM &&
766 dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len) < 0)
767 goto out_free;
768
769 /* Returns -EFAULT on error */
770 err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
771 if (err)
772 goto out_free;
773
774 skb->protocol = proto;
775 skb->dev = dev;
776 skb->priority = sk->sk_priority;
777
778 /*
779 * Now send it
780 */
781
782 err = dev_queue_xmit(skb);
783 if (err > 0 && (err = net_xmit_errno(err)) != 0)
784 goto out_unlock;
785
786 dev_put(dev);
787
788 return(len);
789
790 out_free:
791 kfree_skb(skb);
792 out_unlock:
793 if (dev)
794 dev_put(dev);
795 out:
796 return err;
797 }
798
799 /*
800 * Close a PACKET socket. This is fairly simple. We immediately go
801 * to 'closed' state and remove our protocol entry in the device list.
802 */
803
804 static int packet_release(struct socket *sock)
805 {
806 struct sock *sk = sock->sk;
807 struct packet_sock *po;
808
809 if (!sk)
810 return 0;
811
812 po = pkt_sk(sk);
813
814 write_lock_bh(&packet_sklist_lock);
815 sk_del_node_init(sk);
816 write_unlock_bh(&packet_sklist_lock);
817
818 /*
819 * Unhook packet receive handler.
820 */
821
822 if (po->running) {
823 /*
824 * Remove the protocol hook
825 */
826 dev_remove_pack(&po->prot_hook);
827 po->running = 0;
828 po->num = 0;
829 __sock_put(sk);
830 }
831
832 packet_flush_mclist(sk);
833
834 #ifdef CONFIG_PACKET_MMAP
835 if (po->pg_vec) {
836 struct tpacket_req req;
837 memset(&req, 0, sizeof(req));
838 packet_set_ring(sk, &req, 1);
839 }
840 #endif
841
842 /*
843 * Now the socket is dead. No more input will appear.
844 */
845
846 sock_orphan(sk);
847 sock->sk = NULL;
848
849 /* Purge queues */
850
851 skb_queue_purge(&sk->sk_receive_queue);
852
853 sock_put(sk);
854 return 0;
855 }
856
857 /*
858 * Attach a packet hook.
859 */
860
861 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
862 {
863 struct packet_sock *po = pkt_sk(sk);
864 /*
865 * Detach an existing hook if present.
866 */
867
868 lock_sock(sk);
869
870 spin_lock(&po->bind_lock);
871 if (po->running) {
872 __sock_put(sk);
873 po->running = 0;
874 po->num = 0;
875 spin_unlock(&po->bind_lock);
876 dev_remove_pack(&po->prot_hook);
877 spin_lock(&po->bind_lock);
878 }
879
880 po->num = protocol;
881 po->prot_hook.type = protocol;
882 po->prot_hook.dev = dev;
883
884 po->ifindex = dev ? dev->ifindex : 0;
885
886 if (protocol == 0)
887 goto out_unlock;
888
889 if (dev) {
890 if (dev->flags&IFF_UP) {
891 dev_add_pack(&po->prot_hook);
892 sock_hold(sk);
893 po->running = 1;
894 } else {
895 sk->sk_err = ENETDOWN;
896 if (!sock_flag(sk, SOCK_DEAD))
897 sk->sk_error_report(sk);
898 }
899 } else {
900 dev_add_pack(&po->prot_hook);
901 sock_hold(sk);
902 po->running = 1;
903 }
904
905 out_unlock:
906 spin_unlock(&po->bind_lock);
907 release_sock(sk);
908 return 0;
909 }
910
911 /*
912 * Bind a packet socket to a device
913 */
914
915 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, int addr_len)
916 {
917 struct sock *sk=sock->sk;
918 char name[15];
919 struct net_device *dev;
920 int err = -ENODEV;
921
922 /*
923 * Check legality
924 */
925
926 if (addr_len != sizeof(struct sockaddr))
927 return -EINVAL;
928 strlcpy(name,uaddr->sa_data,sizeof(name));
929
930 dev = dev_get_by_name(&init_net, name);
931 if (dev) {
932 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
933 dev_put(dev);
934 }
935 return err;
936 }
937
938 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
939 {
940 struct sockaddr_ll *sll = (struct sockaddr_ll*)uaddr;
941 struct sock *sk=sock->sk;
942 struct net_device *dev = NULL;
943 int err;
944
945
946 /*
947 * Check legality
948 */
949
950 if (addr_len < sizeof(struct sockaddr_ll))
951 return -EINVAL;
952 if (sll->sll_family != AF_PACKET)
953 return -EINVAL;
954
955 if (sll->sll_ifindex) {
956 err = -ENODEV;
957 dev = dev_get_by_index(&init_net, sll->sll_ifindex);
958 if (dev == NULL)
959 goto out;
960 }
961 err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
962 if (dev)
963 dev_put(dev);
964
965 out:
966 return err;
967 }
968
969 static struct proto packet_proto = {
970 .name = "PACKET",
971 .owner = THIS_MODULE,
972 .obj_size = sizeof(struct packet_sock),
973 };
974
975 /*
976 * Create a packet of type SOCK_PACKET.
977 */
978
979 static int packet_create(struct net *net, struct socket *sock, int protocol)
980 {
981 struct sock *sk;
982 struct packet_sock *po;
983 __be16 proto = (__force __be16)protocol; /* weird, but documented */
984 int err;
985
986 if (net != &init_net)
987 return -EAFNOSUPPORT;
988
989 if (!capable(CAP_NET_RAW))
990 return -EPERM;
991 if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
992 sock->type != SOCK_PACKET)
993 return -ESOCKTNOSUPPORT;
994
995 sock->state = SS_UNCONNECTED;
996
997 err = -ENOBUFS;
998 sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, 1);
999 if (sk == NULL)
1000 goto out;
1001
1002 sock->ops = &packet_ops;
1003 if (sock->type == SOCK_PACKET)
1004 sock->ops = &packet_ops_spkt;
1005
1006 sock_init_data(sock, sk);
1007
1008 po = pkt_sk(sk);
1009 sk->sk_family = PF_PACKET;
1010 po->num = proto;
1011
1012 sk->sk_destruct = packet_sock_destruct;
1013 atomic_inc(&packet_socks_nr);
1014
1015 /*
1016 * Attach a protocol block
1017 */
1018
1019 spin_lock_init(&po->bind_lock);
1020 po->prot_hook.func = packet_rcv;
1021
1022 if (sock->type == SOCK_PACKET)
1023 po->prot_hook.func = packet_rcv_spkt;
1024
1025 po->prot_hook.af_packet_priv = sk;
1026
1027 if (proto) {
1028 po->prot_hook.type = proto;
1029 dev_add_pack(&po->prot_hook);
1030 sock_hold(sk);
1031 po->running = 1;
1032 }
1033
1034 write_lock_bh(&packet_sklist_lock);
1035 sk_add_node(sk, &packet_sklist);
1036 write_unlock_bh(&packet_sklist_lock);
1037 return(0);
1038 out:
1039 return err;
1040 }
1041
1042 /*
1043 * Pull a packet from our receive queue and hand it to the user.
1044 * If necessary we block.
1045 */
1046
1047 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
1048 struct msghdr *msg, size_t len, int flags)
1049 {
1050 struct sock *sk = sock->sk;
1051 struct sk_buff *skb;
1052 int copied, err;
1053 struct sockaddr_ll *sll;
1054
1055 err = -EINVAL;
1056 if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT))
1057 goto out;
1058
1059 #if 0
1060 /* What error should we return now? EUNATTACH? */
1061 if (pkt_sk(sk)->ifindex < 0)
1062 return -ENODEV;
1063 #endif
1064
1065 /*
1066 * Call the generic datagram receiver. This handles all sorts
1067 * of horrible races and re-entrancy so we can forget about it
1068 * in the protocol layers.
1069 *
1070 * Now it will return ENETDOWN, if device have just gone down,
1071 * but then it will block.
1072 */
1073
1074 skb=skb_recv_datagram(sk,flags,flags&MSG_DONTWAIT,&err);
1075
1076 /*
1077 * An error occurred so return it. Because skb_recv_datagram()
1078 * handles the blocking we don't see and worry about blocking
1079 * retries.
1080 */
1081
1082 if (skb == NULL)
1083 goto out;
1084
1085 /*
1086 * If the address length field is there to be filled in, we fill
1087 * it in now.
1088 */
1089
1090 sll = &PACKET_SKB_CB(skb)->sa.ll;
1091 if (sock->type == SOCK_PACKET)
1092 msg->msg_namelen = sizeof(struct sockaddr_pkt);
1093 else
1094 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
1095
1096 /*
1097 * You lose any data beyond the buffer you gave. If it worries a
1098 * user program they can ask the device for its MTU anyway.
1099 */
1100
1101 copied = skb->len;
1102 if (copied > len)
1103 {
1104 copied=len;
1105 msg->msg_flags|=MSG_TRUNC;
1106 }
1107
1108 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1109 if (err)
1110 goto out_free;
1111
1112 sock_recv_timestamp(msg, sk, skb);
1113
1114 if (msg->msg_name)
1115 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
1116 msg->msg_namelen);
1117
1118 if (pkt_sk(sk)->auxdata) {
1119 struct tpacket_auxdata aux;
1120
1121 aux.tp_status = TP_STATUS_USER;
1122 if (skb->ip_summed == CHECKSUM_PARTIAL)
1123 aux.tp_status |= TP_STATUS_CSUMNOTREADY;
1124 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
1125 aux.tp_snaplen = skb->len;
1126 aux.tp_mac = 0;
1127 aux.tp_net = skb_network_offset(skb);
1128
1129 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
1130 }
1131
1132 /*
1133 * Free or return the buffer as appropriate. Again this
1134 * hides all the races and re-entrancy issues from us.
1135 */
1136 err = (flags&MSG_TRUNC) ? skb->len : copied;
1137
1138 out_free:
1139 skb_free_datagram(sk, skb);
1140 out:
1141 return err;
1142 }
1143
1144 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
1145 int *uaddr_len, int peer)
1146 {
1147 struct net_device *dev;
1148 struct sock *sk = sock->sk;
1149
1150 if (peer)
1151 return -EOPNOTSUPP;
1152
1153 uaddr->sa_family = AF_PACKET;
1154 dev = dev_get_by_index(&init_net, pkt_sk(sk)->ifindex);
1155 if (dev) {
1156 strlcpy(uaddr->sa_data, dev->name, 15);
1157 dev_put(dev);
1158 } else
1159 memset(uaddr->sa_data, 0, 14);
1160 *uaddr_len = sizeof(*uaddr);
1161
1162 return 0;
1163 }
1164
1165 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
1166 int *uaddr_len, int peer)
1167 {
1168 struct net_device *dev;
1169 struct sock *sk = sock->sk;
1170 struct packet_sock *po = pkt_sk(sk);
1171 struct sockaddr_ll *sll = (struct sockaddr_ll*)uaddr;
1172
1173 if (peer)
1174 return -EOPNOTSUPP;
1175
1176 sll->sll_family = AF_PACKET;
1177 sll->sll_ifindex = po->ifindex;
1178 sll->sll_protocol = po->num;
1179 dev = dev_get_by_index(&init_net, po->ifindex);
1180 if (dev) {
1181 sll->sll_hatype = dev->type;
1182 sll->sll_halen = dev->addr_len;
1183 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
1184 dev_put(dev);
1185 } else {
1186 sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */
1187 sll->sll_halen = 0;
1188 }
1189 *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
1190
1191 return 0;
1192 }
1193
1194 static void packet_dev_mc(struct net_device *dev, struct packet_mclist *i, int what)
1195 {
1196 switch (i->type) {
1197 case PACKET_MR_MULTICAST:
1198 if (what > 0)
1199 dev_mc_add(dev, i->addr, i->alen, 0);
1200 else
1201 dev_mc_delete(dev, i->addr, i->alen, 0);
1202 break;
1203 case PACKET_MR_PROMISC:
1204 dev_set_promiscuity(dev, what);
1205 break;
1206 case PACKET_MR_ALLMULTI:
1207 dev_set_allmulti(dev, what);
1208 break;
1209 default:;
1210 }
1211 }
1212
1213 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
1214 {
1215 for ( ; i; i=i->next) {
1216 if (i->ifindex == dev->ifindex)
1217 packet_dev_mc(dev, i, what);
1218 }
1219 }
1220
1221 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
1222 {
1223 struct packet_sock *po = pkt_sk(sk);
1224 struct packet_mclist *ml, *i;
1225 struct net_device *dev;
1226 int err;
1227
1228 rtnl_lock();
1229
1230 err = -ENODEV;
1231 dev = __dev_get_by_index(&init_net, mreq->mr_ifindex);
1232 if (!dev)
1233 goto done;
1234
1235 err = -EINVAL;
1236 if (mreq->mr_alen > dev->addr_len)
1237 goto done;
1238
1239 err = -ENOBUFS;
1240 i = kmalloc(sizeof(*i), GFP_KERNEL);
1241 if (i == NULL)
1242 goto done;
1243
1244 err = 0;
1245 for (ml = po->mclist; ml; ml = ml->next) {
1246 if (ml->ifindex == mreq->mr_ifindex &&
1247 ml->type == mreq->mr_type &&
1248 ml->alen == mreq->mr_alen &&
1249 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
1250 ml->count++;
1251 /* Free the new element ... */
1252 kfree(i);
1253 goto done;
1254 }
1255 }
1256
1257 i->type = mreq->mr_type;
1258 i->ifindex = mreq->mr_ifindex;
1259 i->alen = mreq->mr_alen;
1260 memcpy(i->addr, mreq->mr_address, i->alen);
1261 i->count = 1;
1262 i->next = po->mclist;
1263 po->mclist = i;
1264 packet_dev_mc(dev, i, +1);
1265
1266 done:
1267 rtnl_unlock();
1268 return err;
1269 }
1270
1271 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
1272 {
1273 struct packet_mclist *ml, **mlp;
1274
1275 rtnl_lock();
1276
1277 for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
1278 if (ml->ifindex == mreq->mr_ifindex &&
1279 ml->type == mreq->mr_type &&
1280 ml->alen == mreq->mr_alen &&
1281 memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
1282 if (--ml->count == 0) {
1283 struct net_device *dev;
1284 *mlp = ml->next;
1285 dev = dev_get_by_index(&init_net, ml->ifindex);
1286 if (dev) {
1287 packet_dev_mc(dev, ml, -1);
1288 dev_put(dev);
1289 }
1290 kfree(ml);
1291 }
1292 rtnl_unlock();
1293 return 0;
1294 }
1295 }
1296 rtnl_unlock();
1297 return -EADDRNOTAVAIL;
1298 }
1299
1300 static void packet_flush_mclist(struct sock *sk)
1301 {
1302 struct packet_sock *po = pkt_sk(sk);
1303 struct packet_mclist *ml;
1304
1305 if (!po->mclist)
1306 return;
1307
1308 rtnl_lock();
1309 while ((ml = po->mclist) != NULL) {
1310 struct net_device *dev;
1311
1312 po->mclist = ml->next;
1313 if ((dev = dev_get_by_index(&init_net, ml->ifindex)) != NULL) {
1314 packet_dev_mc(dev, ml, -1);
1315 dev_put(dev);
1316 }
1317 kfree(ml);
1318 }
1319 rtnl_unlock();
1320 }
1321
1322 static int
1323 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen)
1324 {
1325 struct sock *sk = sock->sk;
1326 struct packet_sock *po = pkt_sk(sk);
1327 int ret;
1328
1329 if (level != SOL_PACKET)
1330 return -ENOPROTOOPT;
1331
1332 switch(optname) {
1333 case PACKET_ADD_MEMBERSHIP:
1334 case PACKET_DROP_MEMBERSHIP:
1335 {
1336 struct packet_mreq_max mreq;
1337 int len = optlen;
1338 memset(&mreq, 0, sizeof(mreq));
1339 if (len < sizeof(struct packet_mreq))
1340 return -EINVAL;
1341 if (len > sizeof(mreq))
1342 len = sizeof(mreq);
1343 if (copy_from_user(&mreq,optval,len))
1344 return -EFAULT;
1345 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
1346 return -EINVAL;
1347 if (optname == PACKET_ADD_MEMBERSHIP)
1348 ret = packet_mc_add(sk, &mreq);
1349 else
1350 ret = packet_mc_drop(sk, &mreq);
1351 return ret;
1352 }
1353
1354 #ifdef CONFIG_PACKET_MMAP
1355 case PACKET_RX_RING:
1356 {
1357 struct tpacket_req req;
1358
1359 if (optlen<sizeof(req))
1360 return -EINVAL;
1361 if (copy_from_user(&req,optval,sizeof(req)))
1362 return -EFAULT;
1363 return packet_set_ring(sk, &req, 0);
1364 }
1365 case PACKET_COPY_THRESH:
1366 {
1367 int val;
1368
1369 if (optlen!=sizeof(val))
1370 return -EINVAL;
1371 if (copy_from_user(&val,optval,sizeof(val)))
1372 return -EFAULT;
1373
1374 pkt_sk(sk)->copy_thresh = val;
1375 return 0;
1376 }
1377 #endif
1378 case PACKET_AUXDATA:
1379 {
1380 int val;
1381
1382 if (optlen < sizeof(val))
1383 return -EINVAL;
1384 if (copy_from_user(&val, optval, sizeof(val)))
1385 return -EFAULT;
1386
1387 po->auxdata = !!val;
1388 return 0;
1389 }
1390 case PACKET_ORIGDEV:
1391 {
1392 int val;
1393
1394 if (optlen < sizeof(val))
1395 return -EINVAL;
1396 if (copy_from_user(&val, optval, sizeof(val)))
1397 return -EFAULT;
1398
1399 po->origdev = !!val;
1400 return 0;
1401 }
1402 default:
1403 return -ENOPROTOOPT;
1404 }
1405 }
1406
1407 static int packet_getsockopt(struct socket *sock, int level, int optname,
1408 char __user *optval, int __user *optlen)
1409 {
1410 int len;
1411 int val;
1412 struct sock *sk = sock->sk;
1413 struct packet_sock *po = pkt_sk(sk);
1414 void *data;
1415 struct tpacket_stats st;
1416
1417 if (level != SOL_PACKET)
1418 return -ENOPROTOOPT;
1419
1420 if (get_user(len, optlen))
1421 return -EFAULT;
1422
1423 if (len < 0)
1424 return -EINVAL;
1425
1426 switch(optname) {
1427 case PACKET_STATISTICS:
1428 if (len > sizeof(struct tpacket_stats))
1429 len = sizeof(struct tpacket_stats);
1430 spin_lock_bh(&sk->sk_receive_queue.lock);
1431 st = po->stats;
1432 memset(&po->stats, 0, sizeof(st));
1433 spin_unlock_bh(&sk->sk_receive_queue.lock);
1434 st.tp_packets += st.tp_drops;
1435
1436 data = &st;
1437 break;
1438 case PACKET_AUXDATA:
1439 if (len > sizeof(int))
1440 len = sizeof(int);
1441 val = po->auxdata;
1442
1443 data = &val;
1444 break;
1445 case PACKET_ORIGDEV:
1446 if (len > sizeof(int))
1447 len = sizeof(int);
1448 val = po->origdev;
1449
1450 data = &val;
1451 break;
1452 default:
1453 return -ENOPROTOOPT;
1454 }
1455
1456 if (put_user(len, optlen))
1457 return -EFAULT;
1458 if (copy_to_user(optval, data, len))
1459 return -EFAULT;
1460 return 0;
1461 }
1462
1463
1464 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
1465 {
1466 struct sock *sk;
1467 struct hlist_node *node;
1468 struct net_device *dev = data;
1469
1470 if (dev->nd_net != &init_net)
1471 return NOTIFY_DONE;
1472
1473 read_lock(&packet_sklist_lock);
1474 sk_for_each(sk, node, &packet_sklist) {
1475 struct packet_sock *po = pkt_sk(sk);
1476
1477 switch (msg) {
1478 case NETDEV_UNREGISTER:
1479 if (po->mclist)
1480 packet_dev_mclist(dev, po->mclist, -1);
1481 /* fallthrough */
1482
1483 case NETDEV_DOWN:
1484 if (dev->ifindex == po->ifindex) {
1485 spin_lock(&po->bind_lock);
1486 if (po->running) {
1487 __dev_remove_pack(&po->prot_hook);
1488 __sock_put(sk);
1489 po->running = 0;
1490 sk->sk_err = ENETDOWN;
1491 if (!sock_flag(sk, SOCK_DEAD))
1492 sk->sk_error_report(sk);
1493 }
1494 if (msg == NETDEV_UNREGISTER) {
1495 po->ifindex = -1;
1496 po->prot_hook.dev = NULL;
1497 }
1498 spin_unlock(&po->bind_lock);
1499 }
1500 break;
1501 case NETDEV_UP:
1502 spin_lock(&po->bind_lock);
1503 if (dev->ifindex == po->ifindex && po->num &&
1504 !po->running) {
1505 dev_add_pack(&po->prot_hook);
1506 sock_hold(sk);
1507 po->running = 1;
1508 }
1509 spin_unlock(&po->bind_lock);
1510 break;
1511 }
1512 }
1513 read_unlock(&packet_sklist_lock);
1514 return NOTIFY_DONE;
1515 }
1516
1517
1518 static int packet_ioctl(struct socket *sock, unsigned int cmd,
1519 unsigned long arg)
1520 {
1521 struct sock *sk = sock->sk;
1522
1523 switch(cmd) {
1524 case SIOCOUTQ:
1525 {
1526 int amount = atomic_read(&sk->sk_wmem_alloc);
1527 return put_user(amount, (int __user *)arg);
1528 }
1529 case SIOCINQ:
1530 {
1531 struct sk_buff *skb;
1532 int amount = 0;
1533
1534 spin_lock_bh(&sk->sk_receive_queue.lock);
1535 skb = skb_peek(&sk->sk_receive_queue);
1536 if (skb)
1537 amount = skb->len;
1538 spin_unlock_bh(&sk->sk_receive_queue.lock);
1539 return put_user(amount, (int __user *)arg);
1540 }
1541 case SIOCGSTAMP:
1542 return sock_get_timestamp(sk, (struct timeval __user *)arg);
1543 case SIOCGSTAMPNS:
1544 return sock_get_timestampns(sk, (struct timespec __user *)arg);
1545
1546 #ifdef CONFIG_INET
1547 case SIOCADDRT:
1548 case SIOCDELRT:
1549 case SIOCDARP:
1550 case SIOCGARP:
1551 case SIOCSARP:
1552 case SIOCGIFADDR:
1553 case SIOCSIFADDR:
1554 case SIOCGIFBRDADDR:
1555 case SIOCSIFBRDADDR:
1556 case SIOCGIFNETMASK:
1557 case SIOCSIFNETMASK:
1558 case SIOCGIFDSTADDR:
1559 case SIOCSIFDSTADDR:
1560 case SIOCSIFFLAGS:
1561 return inet_dgram_ops.ioctl(sock, cmd, arg);
1562 #endif
1563
1564 default:
1565 return -ENOIOCTLCMD;
1566 }
1567 return 0;
1568 }
1569
1570 #ifndef CONFIG_PACKET_MMAP
1571 #define packet_mmap sock_no_mmap
1572 #define packet_poll datagram_poll
1573 #else
1574
1575 static unsigned int packet_poll(struct file * file, struct socket *sock,
1576 poll_table *wait)
1577 {
1578 struct sock *sk = sock->sk;
1579 struct packet_sock *po = pkt_sk(sk);
1580 unsigned int mask = datagram_poll(file, sock, wait);
1581
1582 spin_lock_bh(&sk->sk_receive_queue.lock);
1583 if (po->pg_vec) {
1584 unsigned last = po->head ? po->head-1 : po->frame_max;
1585 struct tpacket_hdr *h;
1586
1587 h = packet_lookup_frame(po, last);
1588
1589 if (h->tp_status)
1590 mask |= POLLIN | POLLRDNORM;
1591 }
1592 spin_unlock_bh(&sk->sk_receive_queue.lock);
1593 return mask;
1594 }
1595
1596
1597 /* Dirty? Well, I still did not learn better way to account
1598 * for user mmaps.
1599 */
1600
1601 static void packet_mm_open(struct vm_area_struct *vma)
1602 {
1603 struct file *file = vma->vm_file;
1604 struct socket * sock = file->private_data;
1605 struct sock *sk = sock->sk;
1606
1607 if (sk)
1608 atomic_inc(&pkt_sk(sk)->mapped);
1609 }
1610
1611 static void packet_mm_close(struct vm_area_struct *vma)
1612 {
1613 struct file *file = vma->vm_file;
1614 struct socket * sock = file->private_data;
1615 struct sock *sk = sock->sk;
1616
1617 if (sk)
1618 atomic_dec(&pkt_sk(sk)->mapped);
1619 }
1620
1621 static struct vm_operations_struct packet_mmap_ops = {
1622 .open = packet_mm_open,
1623 .close =packet_mm_close,
1624 };
1625
1626 static inline struct page *pg_vec_endpage(char *one_pg_vec, unsigned int order)
1627 {
1628 return virt_to_page(one_pg_vec + (PAGE_SIZE << order) - 1);
1629 }
1630
1631 static void free_pg_vec(char **pg_vec, unsigned int order, unsigned int len)
1632 {
1633 int i;
1634
1635 for (i = 0; i < len; i++) {
1636 if (likely(pg_vec[i]))
1637 free_pages((unsigned long) pg_vec[i], order);
1638 }
1639 kfree(pg_vec);
1640 }
1641
1642 static inline char *alloc_one_pg_vec_page(unsigned long order)
1643 {
1644 return (char *) __get_free_pages(GFP_KERNEL | __GFP_COMP | __GFP_ZERO,
1645 order);
1646 }
1647
1648 static char **alloc_pg_vec(struct tpacket_req *req, int order)
1649 {
1650 unsigned int block_nr = req->tp_block_nr;
1651 char **pg_vec;
1652 int i;
1653
1654 pg_vec = kzalloc(block_nr * sizeof(char *), GFP_KERNEL);
1655 if (unlikely(!pg_vec))
1656 goto out;
1657
1658 for (i = 0; i < block_nr; i++) {
1659 pg_vec[i] = alloc_one_pg_vec_page(order);
1660 if (unlikely(!pg_vec[i]))
1661 goto out_free_pgvec;
1662 }
1663
1664 out:
1665 return pg_vec;
1666
1667 out_free_pgvec:
1668 free_pg_vec(pg_vec, order, block_nr);
1669 pg_vec = NULL;
1670 goto out;
1671 }
1672
1673 static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing)
1674 {
1675 char **pg_vec = NULL;
1676 struct packet_sock *po = pkt_sk(sk);
1677 int was_running, order = 0;
1678 __be16 num;
1679 int err = 0;
1680
1681 if (req->tp_block_nr) {
1682 int i, l;
1683
1684 /* Sanity tests and some calculations */
1685
1686 if (unlikely(po->pg_vec))
1687 return -EBUSY;
1688
1689 if (unlikely((int)req->tp_block_size <= 0))
1690 return -EINVAL;
1691 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
1692 return -EINVAL;
1693 if (unlikely(req->tp_frame_size < TPACKET_HDRLEN))
1694 return -EINVAL;
1695 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
1696 return -EINVAL;
1697
1698 po->frames_per_block = req->tp_block_size/req->tp_frame_size;
1699 if (unlikely(po->frames_per_block <= 0))
1700 return -EINVAL;
1701 if (unlikely((po->frames_per_block * req->tp_block_nr) !=
1702 req->tp_frame_nr))
1703 return -EINVAL;
1704
1705 err = -ENOMEM;
1706 order = get_order(req->tp_block_size);
1707 pg_vec = alloc_pg_vec(req, order);
1708 if (unlikely(!pg_vec))
1709 goto out;
1710
1711 l = 0;
1712 for (i = 0; i < req->tp_block_nr; i++) {
1713 char *ptr = pg_vec[i];
1714 struct tpacket_hdr *header;
1715 int k;
1716
1717 for (k = 0; k < po->frames_per_block; k++) {
1718 header = (struct tpacket_hdr *) ptr;
1719 header->tp_status = TP_STATUS_KERNEL;
1720 ptr += req->tp_frame_size;
1721 }
1722 }
1723 /* Done */
1724 } else {
1725 if (unlikely(req->tp_frame_nr))
1726 return -EINVAL;
1727 }
1728
1729 lock_sock(sk);
1730
1731 /* Detach socket from network */
1732 spin_lock(&po->bind_lock);
1733 was_running = po->running;
1734 num = po->num;
1735 if (was_running) {
1736 __dev_remove_pack(&po->prot_hook);
1737 po->num = 0;
1738 po->running = 0;
1739 __sock_put(sk);
1740 }
1741 spin_unlock(&po->bind_lock);
1742
1743 synchronize_net();
1744
1745 err = -EBUSY;
1746 if (closing || atomic_read(&po->mapped) == 0) {
1747 err = 0;
1748 #define XC(a, b) ({ __typeof__ ((a)) __t; __t = (a); (a) = (b); __t; })
1749
1750 spin_lock_bh(&sk->sk_receive_queue.lock);
1751 pg_vec = XC(po->pg_vec, pg_vec);
1752 po->frame_max = (req->tp_frame_nr - 1);
1753 po->head = 0;
1754 po->frame_size = req->tp_frame_size;
1755 spin_unlock_bh(&sk->sk_receive_queue.lock);
1756
1757 order = XC(po->pg_vec_order, order);
1758 req->tp_block_nr = XC(po->pg_vec_len, req->tp_block_nr);
1759
1760 po->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
1761 po->prot_hook.func = po->pg_vec ? tpacket_rcv : packet_rcv;
1762 skb_queue_purge(&sk->sk_receive_queue);
1763 #undef XC
1764 if (atomic_read(&po->mapped))
1765 printk(KERN_DEBUG "packet_mmap: vma is busy: %d\n", atomic_read(&po->mapped));
1766 }
1767
1768 spin_lock(&po->bind_lock);
1769 if (was_running && !po->running) {
1770 sock_hold(sk);
1771 po->running = 1;
1772 po->num = num;
1773 dev_add_pack(&po->prot_hook);
1774 }
1775 spin_unlock(&po->bind_lock);
1776
1777 release_sock(sk);
1778
1779 if (pg_vec)
1780 free_pg_vec(pg_vec, order, req->tp_block_nr);
1781 out:
1782 return err;
1783 }
1784
1785 static int packet_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1786 {
1787 struct sock *sk = sock->sk;
1788 struct packet_sock *po = pkt_sk(sk);
1789 unsigned long size;
1790 unsigned long start;
1791 int err = -EINVAL;
1792 int i;
1793
1794 if (vma->vm_pgoff)
1795 return -EINVAL;
1796
1797 size = vma->vm_end - vma->vm_start;
1798
1799 lock_sock(sk);
1800 if (po->pg_vec == NULL)
1801 goto out;
1802 if (size != po->pg_vec_len*po->pg_vec_pages*PAGE_SIZE)
1803 goto out;
1804
1805 start = vma->vm_start;
1806 for (i = 0; i < po->pg_vec_len; i++) {
1807 struct page *page = virt_to_page(po->pg_vec[i]);
1808 int pg_num;
1809
1810 for (pg_num = 0; pg_num < po->pg_vec_pages; pg_num++, page++) {
1811 err = vm_insert_page(vma, start, page);
1812 if (unlikely(err))
1813 goto out;
1814 start += PAGE_SIZE;
1815 }
1816 }
1817 atomic_inc(&po->mapped);
1818 vma->vm_ops = &packet_mmap_ops;
1819 err = 0;
1820
1821 out:
1822 release_sock(sk);
1823 return err;
1824 }
1825 #endif
1826
1827
1828 static const struct proto_ops packet_ops_spkt = {
1829 .family = PF_PACKET,
1830 .owner = THIS_MODULE,
1831 .release = packet_release,
1832 .bind = packet_bind_spkt,
1833 .connect = sock_no_connect,
1834 .socketpair = sock_no_socketpair,
1835 .accept = sock_no_accept,
1836 .getname = packet_getname_spkt,
1837 .poll = datagram_poll,
1838 .ioctl = packet_ioctl,
1839 .listen = sock_no_listen,
1840 .shutdown = sock_no_shutdown,
1841 .setsockopt = sock_no_setsockopt,
1842 .getsockopt = sock_no_getsockopt,
1843 .sendmsg = packet_sendmsg_spkt,
1844 .recvmsg = packet_recvmsg,
1845 .mmap = sock_no_mmap,
1846 .sendpage = sock_no_sendpage,
1847 };
1848
1849 static const struct proto_ops packet_ops = {
1850 .family = PF_PACKET,
1851 .owner = THIS_MODULE,
1852 .release = packet_release,
1853 .bind = packet_bind,
1854 .connect = sock_no_connect,
1855 .socketpair = sock_no_socketpair,
1856 .accept = sock_no_accept,
1857 .getname = packet_getname,
1858 .poll = packet_poll,
1859 .ioctl = packet_ioctl,
1860 .listen = sock_no_listen,
1861 .shutdown = sock_no_shutdown,
1862 .setsockopt = packet_setsockopt,
1863 .getsockopt = packet_getsockopt,
1864 .sendmsg = packet_sendmsg,
1865 .recvmsg = packet_recvmsg,
1866 .mmap = packet_mmap,
1867 .sendpage = sock_no_sendpage,
1868 };
1869
1870 static struct net_proto_family packet_family_ops = {
1871 .family = PF_PACKET,
1872 .create = packet_create,
1873 .owner = THIS_MODULE,
1874 };
1875
1876 static struct notifier_block packet_netdev_notifier = {
1877 .notifier_call =packet_notifier,
1878 };
1879
1880 #ifdef CONFIG_PROC_FS
1881 static inline struct sock *packet_seq_idx(loff_t off)
1882 {
1883 struct sock *s;
1884 struct hlist_node *node;
1885
1886 sk_for_each(s, node, &packet_sklist) {
1887 if (!off--)
1888 return s;
1889 }
1890 return NULL;
1891 }
1892
1893 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
1894 {
1895 read_lock(&packet_sklist_lock);
1896 return *pos ? packet_seq_idx(*pos - 1) : SEQ_START_TOKEN;
1897 }
1898
1899 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1900 {
1901 ++*pos;
1902 return (v == SEQ_START_TOKEN)
1903 ? sk_head(&packet_sklist)
1904 : sk_next((struct sock*)v) ;
1905 }
1906
1907 static void packet_seq_stop(struct seq_file *seq, void *v)
1908 {
1909 read_unlock(&packet_sklist_lock);
1910 }
1911
1912 static int packet_seq_show(struct seq_file *seq, void *v)
1913 {
1914 if (v == SEQ_START_TOKEN)
1915 seq_puts(seq, "sk RefCnt Type Proto Iface R Rmem User Inode\n");
1916 else {
1917 struct sock *s = v;
1918 const struct packet_sock *po = pkt_sk(s);
1919
1920 seq_printf(seq,
1921 "%p %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n",
1922 s,
1923 atomic_read(&s->sk_refcnt),
1924 s->sk_type,
1925 ntohs(po->num),
1926 po->ifindex,
1927 po->running,
1928 atomic_read(&s->sk_rmem_alloc),
1929 sock_i_uid(s),
1930 sock_i_ino(s) );
1931 }
1932
1933 return 0;
1934 }
1935
1936 static const struct seq_operations packet_seq_ops = {
1937 .start = packet_seq_start,
1938 .next = packet_seq_next,
1939 .stop = packet_seq_stop,
1940 .show = packet_seq_show,
1941 };
1942
1943 static int packet_seq_open(struct inode *inode, struct file *file)
1944 {
1945 return seq_open(file, &packet_seq_ops);
1946 }
1947
1948 static const struct file_operations packet_seq_fops = {
1949 .owner = THIS_MODULE,
1950 .open = packet_seq_open,
1951 .read = seq_read,
1952 .llseek = seq_lseek,
1953 .release = seq_release,
1954 };
1955
1956 #endif
1957
1958 static void __exit packet_exit(void)
1959 {
1960 proc_net_remove(&init_net, "packet");
1961 unregister_netdevice_notifier(&packet_netdev_notifier);
1962 sock_unregister(PF_PACKET);
1963 proto_unregister(&packet_proto);
1964 }
1965
1966 static int __init packet_init(void)
1967 {
1968 int rc = proto_register(&packet_proto, 0);
1969
1970 if (rc != 0)
1971 goto out;
1972
1973 sock_register(&packet_family_ops);
1974 register_netdevice_notifier(&packet_netdev_notifier);
1975 proc_net_fops_create(&init_net, "packet", 0, &packet_seq_fops);
1976 out:
1977 return rc;
1978 }
1979
1980 module_init(packet_init);
1981 module_exit(packet_exit);
1982 MODULE_LICENSE("GPL");
1983 MODULE_ALIAS_NETPROTO(PF_PACKET);
Linux kernel - Deliverables
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