1 /*
2 * raw.c - Raw sockets for protocol family CAN
3 *
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 * Send feedback to <socketcan-users@lists.berlios.de>
41 *
42 */
43
44 #include <linux/module.h>
45 #include <linux/init.h>
46 #include <linux/uio.h>
47 #include <linux/net.h>
48 #include <linux/netdevice.h>
49 #include <linux/socket.h>
50 #include <linux/if_arp.h>
51 #include <linux/skbuff.h>
52 #include <linux/can.h>
53 #include <linux/can/core.h>
54 #include <linux/can/raw.h>
55 #include <net/sock.h>
56 #include <net/net_namespace.h>
57
58 #define CAN_RAW_VERSION CAN_VERSION
59 static __initdata const char banner[] =
60 KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";
61
62 MODULE_DESCRIPTION("PF_CAN raw protocol");
63 MODULE_LICENSE("Dual BSD/GPL");
64 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
65
66 #define MASK_ALL 0
67
68 /*
69 * A raw socket has a list of can_filters attached to it, each receiving
70 * the CAN frames matching that filter. If the filter list is empty,
71 * no CAN frames will be received by the socket. The default after
72 * opening the socket, is to have one filter which receives all frames.
73 * The filter list is allocated dynamically with the exception of the
74 * list containing only one item. This common case is optimized by
75 * storing the single filter in dfilter, to avoid using dynamic memory.
76 */
77
78 struct raw_sock {
79 struct sock sk;
80 int bound;
81 int ifindex;
82 struct notifier_block notifier;
83 int loopback;
84 int recv_own_msgs;
85 int count; /* number of active filters */
86 struct can_filter dfilter; /* default/single filter */
87 struct can_filter *filter; /* pointer to filter(s) */
88 can_err_mask_t err_mask;
89 };
90
91 static inline struct raw_sock *raw_sk(const struct sock *sk)
92 {
93 return (struct raw_sock *)sk;
94 }
95
96 static void raw_rcv(struct sk_buff *skb, void *data)
97 {
98 struct sock *sk = (struct sock *)data;
99 struct raw_sock *ro = raw_sk(sk);
100 struct sockaddr_can *addr;
101
102 if (!ro->recv_own_msgs) {
103 /* check the received tx sock reference */
104 if (skb->sk == sk) {
105 kfree_skb(skb);
106 return;
107 }
108 }
109
110 /*
111 * Put the datagram to the queue so that raw_recvmsg() can
112 * get it from there. We need to pass the interface index to
113 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
114 * containing the interface index.
115 */
116
117 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
118 addr = (struct sockaddr_can *)skb->cb;
119 memset(addr, 0, sizeof(*addr));
120 addr->can_family = AF_CAN;
121 addr->can_ifindex = skb->dev->ifindex;
122
123 if (sock_queue_rcv_skb(sk, skb) < 0)
124 kfree_skb(skb);
125 }
126
127 static int raw_enable_filters(struct net_device *dev, struct sock *sk,
128 struct can_filter *filter, int count)
129 {
130 int err = 0;
131 int i;
132
133 for (i = 0; i < count; i++) {
134 err = can_rx_register(dev, filter[i].can_id,
135 filter[i].can_mask,
136 raw_rcv, sk, "raw");
137 if (err) {
138 /* clean up successfully registered filters */
139 while (--i >= 0)
140 can_rx_unregister(dev, filter[i].can_id,
141 filter[i].can_mask,
142 raw_rcv, sk);
143 break;
144 }
145 }
146
147 return err;
148 }
149
150 static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
151 can_err_mask_t err_mask)
152 {
153 int err = 0;
154
155 if (err_mask)
156 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
157 raw_rcv, sk, "raw");
158
159 return err;
160 }
161
162 static void raw_disable_filters(struct net_device *dev, struct sock *sk,
163 struct can_filter *filter, int count)
164 {
165 int i;
166
167 for (i = 0; i < count; i++)
168 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
169 raw_rcv, sk);
170 }
171
172 static inline void raw_disable_errfilter(struct net_device *dev,
173 struct sock *sk,
174 can_err_mask_t err_mask)
175
176 {
177 if (err_mask)
178 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
179 raw_rcv, sk);
180 }
181
182 static inline void raw_disable_allfilters(struct net_device *dev,
183 struct sock *sk)
184 {
185 struct raw_sock *ro = raw_sk(sk);
186
187 raw_disable_filters(dev, sk, ro->filter, ro->count);
188 raw_disable_errfilter(dev, sk, ro->err_mask);
189 }
190
191 static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
192 {
193 struct raw_sock *ro = raw_sk(sk);
194 int err;
195
196 err = raw_enable_filters(dev, sk, ro->filter, ro->count);
197 if (!err) {
198 err = raw_enable_errfilter(dev, sk, ro->err_mask);
199 if (err)
200 raw_disable_filters(dev, sk, ro->filter, ro->count);
201 }
202
203 return err;
204 }
205
206 static int raw_notifier(struct notifier_block *nb,
207 unsigned long msg, void *data)
208 {
209 struct net_device *dev = (struct net_device *)data;
210 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
211 struct sock *sk = &ro->sk;
212
213 if (dev->nd_net != &init_net)
214 return NOTIFY_DONE;
215
216 if (dev->type != ARPHRD_CAN)
217 return NOTIFY_DONE;
218
219 if (ro->ifindex != dev->ifindex)
220 return NOTIFY_DONE;
221
222 switch (msg) {
223
224 case NETDEV_UNREGISTER:
225 lock_sock(sk);
226 /* remove current filters & unregister */
227 if (ro->bound)
228 raw_disable_allfilters(dev, sk);
229
230 if (ro->count > 1)
231 kfree(ro->filter);
232
233 ro->ifindex = 0;
234 ro->bound = 0;
235 ro->count = 0;
236 release_sock(sk);
237
238 sk->sk_err = ENODEV;
239 if (!sock_flag(sk, SOCK_DEAD))
240 sk->sk_error_report(sk);
241 break;
242
243 case NETDEV_DOWN:
244 sk->sk_err = ENETDOWN;
245 if (!sock_flag(sk, SOCK_DEAD))
246 sk->sk_error_report(sk);
247 break;
248 }
249
250 return NOTIFY_DONE;
251 }
252
253 static int raw_init(struct sock *sk)
254 {
255 struct raw_sock *ro = raw_sk(sk);
256
257 ro->bound = 0;
258 ro->ifindex = 0;
259
260 /* set default filter to single entry dfilter */
261 ro->dfilter.can_id = 0;
262 ro->dfilter.can_mask = MASK_ALL;
263 ro->filter = &ro->dfilter;
264 ro->count = 1;
265
266 /* set default loopback behaviour */
267 ro->loopback = 1;
268 ro->recv_own_msgs = 0;
269
270 /* set notifier */
271 ro->notifier.notifier_call = raw_notifier;
272
273 register_netdevice_notifier(&ro->notifier);
274
275 return 0;
276 }
277
278 static int raw_release(struct socket *sock)
279 {
280 struct sock *sk = sock->sk;
281 struct raw_sock *ro = raw_sk(sk);
282
283 unregister_netdevice_notifier(&ro->notifier);
284
285 lock_sock(sk);
286
287 /* remove current filters & unregister */
288 if (ro->bound) {
289 if (ro->ifindex) {
290 struct net_device *dev;
291
292 dev = dev_get_by_index(&init_net, ro->ifindex);
293 if (dev) {
294 raw_disable_allfilters(dev, sk);
295 dev_put(dev);
296 }
297 } else
298 raw_disable_allfilters(NULL, sk);
299 }
300
301 if (ro->count > 1)
302 kfree(ro->filter);
303
304 ro->ifindex = 0;
305 ro->bound = 0;
306 ro->count = 0;
307
308 release_sock(sk);
309 sock_put(sk);
310
311 return 0;
312 }
313
314 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
315 {
316 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
317 struct sock *sk = sock->sk;
318 struct raw_sock *ro = raw_sk(sk);
319 int ifindex;
320 int err = 0;
321 int notify_enetdown = 0;
322
323 if (len < sizeof(*addr))
324 return -EINVAL;
325
326 lock_sock(sk);
327
328 if (ro->bound && addr->can_ifindex == ro->ifindex)
329 goto out;
330
331 if (addr->can_ifindex) {
332 struct net_device *dev;
333
334 dev = dev_get_by_index(&init_net, addr->can_ifindex);
335 if (!dev) {
336 err = -ENODEV;
337 goto out;
338 }
339 if (dev->type != ARPHRD_CAN) {
340 dev_put(dev);
341 err = -ENODEV;
342 goto out;
343 }
344 if (!(dev->flags & IFF_UP))
345 notify_enetdown = 1;
346
347 ifindex = dev->ifindex;
348
349 /* filters set by default/setsockopt */
350 err = raw_enable_allfilters(dev, sk);
351 dev_put(dev);
352 } else {
353 ifindex = 0;
354
355 /* filters set by default/setsockopt */
356 err = raw_enable_allfilters(NULL, sk);
357 }
358
359 if (!err) {
360 if (ro->bound) {
361 /* unregister old filters */
362 if (ro->ifindex) {
363 struct net_device *dev;
364
365 dev = dev_get_by_index(&init_net, ro->ifindex);
366 if (dev) {
367 raw_disable_allfilters(dev, sk);
368 dev_put(dev);
369 }
370 } else
371 raw_disable_allfilters(NULL, sk);
372 }
373 ro->ifindex = ifindex;
374 ro->bound = 1;
375 }
376
377 out:
378 release_sock(sk);
379
380 if (notify_enetdown) {
381 sk->sk_err = ENETDOWN;
382 if (!sock_flag(sk, SOCK_DEAD))
383 sk->sk_error_report(sk);
384 }
385
386 return err;
387 }
388
389 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
390 int *len, int peer)
391 {
392 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
393 struct sock *sk = sock->sk;
394 struct raw_sock *ro = raw_sk(sk);
395
396 if (peer)
397 return -EOPNOTSUPP;
398
399 addr->can_family = AF_CAN;
400 addr->can_ifindex = ro->ifindex;
401
402 *len = sizeof(*addr);
403
404 return 0;
405 }
406
407 static int raw_setsockopt(struct socket *sock, int level, int optname,
408 char __user *optval, int optlen)
409 {
410 struct sock *sk = sock->sk;
411 struct raw_sock *ro = raw_sk(sk);
412 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
413 struct can_filter sfilter; /* single filter */
414 struct net_device *dev = NULL;
415 can_err_mask_t err_mask = 0;
416 int count = 0;
417 int err = 0;
418
419 if (level != SOL_CAN_RAW)
420 return -EINVAL;
421 if (optlen < 0)
422 return -EINVAL;
423
424 switch (optname) {
425
426 case CAN_RAW_FILTER:
427 if (optlen % sizeof(struct can_filter) != 0)
428 return -EINVAL;
429
430 count = optlen / sizeof(struct can_filter);
431
432 if (count > 1) {
433 /* filter does not fit into dfilter => alloc space */
434 filter = kmalloc(optlen, GFP_KERNEL);
435 if (!filter)
436 return -ENOMEM;
437
438 if (copy_from_user(filter, optval, optlen)) {
439 kfree(filter);
440 return -EFAULT;
441 }
442 } else if (count == 1) {
443 if (copy_from_user(&sfilter, optval, optlen))
444 return -EFAULT;
445 }
446
447 lock_sock(sk);
448
449 if (ro->bound && ro->ifindex)
450 dev = dev_get_by_index(&init_net, ro->ifindex);
451
452 if (ro->bound) {
453 /* (try to) register the new filters */
454 if (count == 1)
455 err = raw_enable_filters(dev, sk, &sfilter, 1);
456 else
457 err = raw_enable_filters(dev, sk, filter,
458 count);
459 if (err) {
460 if (count > 1)
461 kfree(filter);
462 goto out_fil;
463 }
464
465 /* remove old filter registrations */
466 raw_disable_filters(dev, sk, ro->filter, ro->count);
467 }
468
469 /* remove old filter space */
470 if (ro->count > 1)
471 kfree(ro->filter);
472
473 /* link new filters to the socket */
474 if (count == 1) {
475 /* copy filter data for single filter */
476 ro->dfilter = sfilter;
477 filter = &ro->dfilter;
478 }
479 ro->filter = filter;
480 ro->count = count;
481
482 out_fil:
483 if (dev)
484 dev_put(dev);
485
486 release_sock(sk);
487
488 break;
489
490 case CAN_RAW_ERR_FILTER:
491 if (optlen != sizeof(err_mask))
492 return -EINVAL;
493
494 if (copy_from_user(&err_mask, optval, optlen))
495 return -EFAULT;
496
497 err_mask &= CAN_ERR_MASK;
498
499 lock_sock(sk);
500
501 if (ro->bound && ro->ifindex)
502 dev = dev_get_by_index(&init_net, ro->ifindex);
503
504 /* remove current error mask */
505 if (ro->bound) {
506 /* (try to) register the new err_mask */
507 err = raw_enable_errfilter(dev, sk, err_mask);
508
509 if (err)
510 goto out_err;
511
512 /* remove old err_mask registration */
513 raw_disable_errfilter(dev, sk, ro->err_mask);
514 }
515
516 /* link new err_mask to the socket */
517 ro->err_mask = err_mask;
518
519 out_err:
520 if (dev)
521 dev_put(dev);
522
523 release_sock(sk);
524
525 break;
526
527 case CAN_RAW_LOOPBACK:
528 if (optlen != sizeof(ro->loopback))
529 return -EINVAL;
530
531 if (copy_from_user(&ro->loopback, optval, optlen))
532 return -EFAULT;
533
534 break;
535
536 case CAN_RAW_RECV_OWN_MSGS:
537 if (optlen != sizeof(ro->recv_own_msgs))
538 return -EINVAL;
539
540 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
541 return -EFAULT;
542
543 break;
544
545 default:
546 return -ENOPROTOOPT;
547 }
548 return err;
549 }
550
551 static int raw_getsockopt(struct socket *sock, int level, int optname,
552 char __user *optval, int __user *optlen)
553 {
554 struct sock *sk = sock->sk;
555 struct raw_sock *ro = raw_sk(sk);
556 int len;
557 void *val;
558 int err = 0;
559
560 if (level != SOL_CAN_RAW)
561 return -EINVAL;
562 if (get_user(len, optlen))
563 return -EFAULT;
564 if (len < 0)
565 return -EINVAL;
566
567 switch (optname) {
568
569 case CAN_RAW_FILTER:
570 lock_sock(sk);
571 if (ro->count > 0) {
572 int fsize = ro->count * sizeof(struct can_filter);
573 if (len > fsize)
574 len = fsize;
575 if (copy_to_user(optval, ro->filter, len))
576 err = -EFAULT;
577 } else
578 len = 0;
579 release_sock(sk);
580
581 if (!err)
582 err = put_user(len, optlen);
583 return err;
584
585 case CAN_RAW_ERR_FILTER:
586 if (len > sizeof(can_err_mask_t))
587 len = sizeof(can_err_mask_t);
588 val = &ro->err_mask;
589 break;
590
591 case CAN_RAW_LOOPBACK:
592 if (len > sizeof(int))
593 len = sizeof(int);
594 val = &ro->loopback;
595 break;
596
597 case CAN_RAW_RECV_OWN_MSGS:
598 if (len > sizeof(int))
599 len = sizeof(int);
600 val = &ro->recv_own_msgs;
601 break;
602
603 default:
604 return -ENOPROTOOPT;
605 }
606
607 if (put_user(len, optlen))
608 return -EFAULT;
609 if (copy_to_user(optval, val, len))
610 return -EFAULT;
611 return 0;
612 }
613
614 static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
615 struct msghdr *msg, size_t size)
616 {
617 struct sock *sk = sock->sk;
618 struct raw_sock *ro = raw_sk(sk);
619 struct sk_buff *skb;
620 struct net_device *dev;
621 int ifindex;
622 int err;
623
624 if (msg->msg_name) {
625 struct sockaddr_can *addr =
626 (struct sockaddr_can *)msg->msg_name;
627
628 if (addr->can_family != AF_CAN)
629 return -EINVAL;
630
631 ifindex = addr->can_ifindex;
632 } else
633 ifindex = ro->ifindex;
634
635 dev = dev_get_by_index(&init_net, ifindex);
636 if (!dev)
637 return -ENXIO;
638
639 skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
640 &err);
641 if (!skb) {
642 dev_put(dev);
643 return err;
644 }
645
646 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
647 if (err < 0) {
648 kfree_skb(skb);
649 dev_put(dev);
650 return err;
651 }
652 skb->dev = dev;
653 skb->sk = sk;
654
655 err = can_send(skb, ro->loopback);
656
657 dev_put(dev);
658
659 if (err)
660 return err;
661
662 return size;
663 }
664
665 static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
666 struct msghdr *msg, size_t size, int flags)
667 {
668 struct sock *sk = sock->sk;
669 struct sk_buff *skb;
670 int err = 0;
671 int noblock;
672
673 noblock = flags & MSG_DONTWAIT;
674 flags &= ~MSG_DONTWAIT;
675
676 skb = skb_recv_datagram(sk, flags, noblock, &err);
677 if (!skb)
678 return err;
679
680 if (size < skb->len)
681 msg->msg_flags |= MSG_TRUNC;
682 else
683 size = skb->len;
684
685 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
686 if (err < 0) {
687 skb_free_datagram(sk, skb);
688 return err;
689 }
690
691 sock_recv_timestamp(msg, sk, skb);
692
693 if (msg->msg_name) {
694 msg->msg_namelen = sizeof(struct sockaddr_can);
695 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
696 }
697
698 skb_free_datagram(sk, skb);
699
700 return size;
701 }
702
703 static struct proto_ops raw_ops __read_mostly = {
704 .family = PF_CAN,
705 .release = raw_release,
706 .bind = raw_bind,
707 .connect = sock_no_connect,
708 .socketpair = sock_no_socketpair,
709 .accept = sock_no_accept,
710 .getname = raw_getname,
711 .poll = datagram_poll,
712 .ioctl = NULL, /* use can_ioctl() from af_can.c */
713 .listen = sock_no_listen,
714 .shutdown = sock_no_shutdown,
715 .setsockopt = raw_setsockopt,
716 .getsockopt = raw_getsockopt,
717 .sendmsg = raw_sendmsg,
718 .recvmsg = raw_recvmsg,
719 .mmap = sock_no_mmap,
720 .sendpage = sock_no_sendpage,
721 };
722
723 static struct proto raw_proto __read_mostly = {
724 .name = "CAN_RAW",
725 .owner = THIS_MODULE,
726 .obj_size = sizeof(struct raw_sock),
727 .init = raw_init,
728 };
729
730 static struct can_proto raw_can_proto __read_mostly = {
731 .type = SOCK_RAW,
732 .protocol = CAN_RAW,
733 .capability = -1,
734 .ops = &raw_ops,
735 .prot = &raw_proto,
736 };
737
738 static __init int raw_module_init(void)
739 {
740 int err;
741
742 printk(banner);
743
744 err = can_proto_register(&raw_can_proto);
745 if (err < 0)
746 printk(KERN_ERR "can: registration of raw protocol failed\n");
747
748 return err;
749 }
750
751 static __exit void raw_module_exit(void)
752 {
753 can_proto_unregister(&raw_can_proto);
754 }
755
756 module_init(raw_module_init);
757 module_exit(raw_module_exit);
758
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