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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/slab.h>
49#include <linux/netdevice.h>
50#include <linux/socket.h>
51#include <linux/if_arp.h>
52#include <linux/skbuff.h>
53#include <linux/can.h>
54#include <linux/can/core.h>
55#include <linux/can/raw.h>
56#include <net/sock.h>
57#include <net/net_namespace.h>
58
59#define CAN_RAW_VERSION CAN_VERSION
60static __initdata const char banner[] =
61 KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";
62
63MODULE_DESCRIPTION("PF_CAN raw protocol");
64MODULE_LICENSE("Dual BSD/GPL");
65MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
66MODULE_ALIAS("can-proto-1");
67
68#define MASK_ALL 0
69
70/*
71 * A raw socket has a list of can_filters attached to it, each receiving
72 * the CAN frames matching that filter. If the filter list is empty,
73 * no CAN frames will be received by the socket. The default after
74 * opening the socket, is to have one filter which receives all frames.
75 * The filter list is allocated dynamically with the exception of the
76 * list containing only one item. This common case is optimized by
77 * storing the single filter in dfilter, to avoid using dynamic memory.
78 */
79
80struct raw_sock {
81 struct sock sk;
82 int bound;
83 int ifindex;
84 struct notifier_block notifier;
85 int loopback;
86 int recv_own_msgs;
87 int count; /* number of active filters */
88 struct can_filter dfilter; /* default/single filter */
89 struct can_filter *filter; /* pointer to filter(s) */
90 can_err_mask_t err_mask;
91};
92
93/*
94 * Return pointer to store the extra msg flags for raw_recvmsg().
95 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
96 * in skb->cb.
97 */
98static inline unsigned int *raw_flags(struct sk_buff *skb)
99{
100 BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) +
101 sizeof(unsigned int)));
102
103 /* return pointer after struct sockaddr_can */
104 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
105}
106
107static inline struct raw_sock *raw_sk(const struct sock *sk)
108{
109 return (struct raw_sock *)sk;
110}
111
112static void raw_rcv(struct sk_buff *oskb, void *data)
113{
114 struct sock *sk = (struct sock *)data;
115 struct raw_sock *ro = raw_sk(sk);
116 struct sockaddr_can *addr;
117 struct sk_buff *skb;
118 unsigned int *pflags;
119
120 /* check the received tx sock reference */
121 if (!ro->recv_own_msgs && oskb->sk == sk)
122 return;
123
124 /* clone the given skb to be able to enqueue it into the rcv queue */
125 skb = skb_clone(oskb, GFP_ATOMIC);
126 if (!skb)
127 return;
128
129 /*
130 * Put the datagram to the queue so that raw_recvmsg() can
131 * get it from there. We need to pass the interface index to
132 * raw_recvmsg(). We pass a whole struct sockaddr_can in skb->cb
133 * containing the interface index.
134 */
135
136 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
137 addr = (struct sockaddr_can *)skb->cb;
138 memset(addr, 0, sizeof(*addr));
139 addr->can_family = AF_CAN;
140 addr->can_ifindex = skb->dev->ifindex;
141
142 /* add CAN specific message flags for raw_recvmsg() */
143 pflags = raw_flags(skb);
144 *pflags = 0;
145 if (oskb->sk)
146 *pflags |= MSG_DONTROUTE;
147 if (oskb->sk == sk)
148 *pflags |= MSG_CONFIRM;
149
150 if (sock_queue_rcv_skb(sk, skb) < 0)
151 kfree_skb(skb);
152}
153
154static int raw_enable_filters(struct net_device *dev, struct sock *sk,
155 struct can_filter *filter, int count)
156{
157 int err = 0;
158 int i;
159
160 for (i = 0; i < count; i++) {
161 err = can_rx_register(dev, filter[i].can_id,
162 filter[i].can_mask,
163 raw_rcv, sk, "raw");
164 if (err) {
165 /* clean up successfully registered filters */
166 while (--i >= 0)
167 can_rx_unregister(dev, filter[i].can_id,
168 filter[i].can_mask,
169 raw_rcv, sk);
170 break;
171 }
172 }
173
174 return err;
175}
176
177static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
178 can_err_mask_t err_mask)
179{
180 int err = 0;
181
182 if (err_mask)
183 err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
184 raw_rcv, sk, "raw");
185
186 return err;
187}
188
189static void raw_disable_filters(struct net_device *dev, struct sock *sk,
190 struct can_filter *filter, int count)
191{
192 int i;
193
194 for (i = 0; i < count; i++)
195 can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
196 raw_rcv, sk);
197}
198
199static inline void raw_disable_errfilter(struct net_device *dev,
200 struct sock *sk,
201 can_err_mask_t err_mask)
202
203{
204 if (err_mask)
205 can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
206 raw_rcv, sk);
207}
208
209static inline void raw_disable_allfilters(struct net_device *dev,
210 struct sock *sk)
211{
212 struct raw_sock *ro = raw_sk(sk);
213
214 raw_disable_filters(dev, sk, ro->filter, ro->count);
215 raw_disable_errfilter(dev, sk, ro->err_mask);
216}
217
218static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
219{
220 struct raw_sock *ro = raw_sk(sk);
221 int err;
222
223 err = raw_enable_filters(dev, sk, ro->filter, ro->count);
224 if (!err) {
225 err = raw_enable_errfilter(dev, sk, ro->err_mask);
226 if (err)
227 raw_disable_filters(dev, sk, ro->filter, ro->count);
228 }
229
230 return err;
231}
232
233static int raw_notifier(struct notifier_block *nb,
234 unsigned long msg, void *data)
235{
236 struct net_device *dev = (struct net_device *)data;
237 struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
238 struct sock *sk = &ro->sk;
239
240 if (!net_eq(dev_net(dev), &init_net))
241 return NOTIFY_DONE;
242
243 if (dev->type != ARPHRD_CAN)
244 return NOTIFY_DONE;
245
246 if (ro->ifindex != dev->ifindex)
247 return NOTIFY_DONE;
248
249 switch (msg) {
250
251 case NETDEV_UNREGISTER:
252 lock_sock(sk);
253 /* remove current filters & unregister */
254 if (ro->bound)
255 raw_disable_allfilters(dev, sk);
256
257 if (ro->count > 1)
258 kfree(ro->filter);
259
260 ro->ifindex = 0;
261 ro->bound = 0;
262 ro->count = 0;
263 release_sock(sk);
264
265 sk->sk_err = ENODEV;
266 if (!sock_flag(sk, SOCK_DEAD))
267 sk->sk_error_report(sk);
268 break;
269
270 case NETDEV_DOWN:
271 sk->sk_err = ENETDOWN;
272 if (!sock_flag(sk, SOCK_DEAD))
273 sk->sk_error_report(sk);
274 break;
275 }
276
277 return NOTIFY_DONE;
278}
279
280static int raw_init(struct sock *sk)
281{
282 struct raw_sock *ro = raw_sk(sk);
283
284 ro->bound = 0;
285 ro->ifindex = 0;
286
287 /* set default filter to single entry dfilter */
288 ro->dfilter.can_id = 0;
289 ro->dfilter.can_mask = MASK_ALL;
290 ro->filter = &ro->dfilter;
291 ro->count = 1;
292
293 /* set default loopback behaviour */
294 ro->loopback = 1;
295 ro->recv_own_msgs = 0;
296
297 /* set notifier */
298 ro->notifier.notifier_call = raw_notifier;
299
300 register_netdevice_notifier(&ro->notifier);
301
302 return 0;
303}
304
305static int raw_release(struct socket *sock)
306{
307 struct sock *sk = sock->sk;
308 struct raw_sock *ro;
309
310 if (!sk)
311 return 0;
312
313 ro = raw_sk(sk);
314
315 unregister_netdevice_notifier(&ro->notifier);
316
317 lock_sock(sk);
318
319 /* remove current filters & unregister */
320 if (ro->bound) {
321 if (ro->ifindex) {
322 struct net_device *dev;
323
324 dev = dev_get_by_index(&init_net, ro->ifindex);
325 if (dev) {
326 raw_disable_allfilters(dev, sk);
327 dev_put(dev);
328 }
329 } else
330 raw_disable_allfilters(NULL, sk);
331 }
332
333 if (ro->count > 1)
334 kfree(ro->filter);
335
336 ro->ifindex = 0;
337 ro->bound = 0;
338 ro->count = 0;
339
340 sock_orphan(sk);
341 sock->sk = NULL;
342
343 release_sock(sk);
344 sock_put(sk);
345
346 return 0;
347}
348
349static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
350{
351 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
352 struct sock *sk = sock->sk;
353 struct raw_sock *ro = raw_sk(sk);
354 int ifindex;
355 int err = 0;
356 int notify_enetdown = 0;
357
358 if (len < sizeof(*addr))
359 return -EINVAL;
360
361 lock_sock(sk);
362
363 if (ro->bound && addr->can_ifindex == ro->ifindex)
364 goto out;
365
366 if (addr->can_ifindex) {
367 struct net_device *dev;
368
369 dev = dev_get_by_index(&init_net, addr->can_ifindex);
370 if (!dev) {
371 err = -ENODEV;
372 goto out;
373 }
374 if (dev->type != ARPHRD_CAN) {
375 dev_put(dev);
376 err = -ENODEV;
377 goto out;
378 }
379 if (!(dev->flags & IFF_UP))
380 notify_enetdown = 1;
381
382 ifindex = dev->ifindex;
383
384 /* filters set by default/setsockopt */
385 err = raw_enable_allfilters(dev, sk);
386 dev_put(dev);
387 } else {
388 ifindex = 0;
389
390 /* filters set by default/setsockopt */
391 err = raw_enable_allfilters(NULL, sk);
392 }
393
394 if (!err) {
395 if (ro->bound) {
396 /* unregister old filters */
397 if (ro->ifindex) {
398 struct net_device *dev;
399
400 dev = dev_get_by_index(&init_net, ro->ifindex);
401 if (dev) {
402 raw_disable_allfilters(dev, sk);
403 dev_put(dev);
404 }
405 } else
406 raw_disable_allfilters(NULL, sk);
407 }
408 ro->ifindex = ifindex;
409 ro->bound = 1;
410 }
411
412 out:
413 release_sock(sk);
414
415 if (notify_enetdown) {
416 sk->sk_err = ENETDOWN;
417 if (!sock_flag(sk, SOCK_DEAD))
418 sk->sk_error_report(sk);
419 }
420
421 return err;
422}
423
424static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
425 int *len, int peer)
426{
427 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
428 struct sock *sk = sock->sk;
429 struct raw_sock *ro = raw_sk(sk);
430
431 if (peer)
432 return -EOPNOTSUPP;
433
434 memset(addr, 0, sizeof(*addr));
435 addr->can_family = AF_CAN;
436 addr->can_ifindex = ro->ifindex;
437
438 *len = sizeof(*addr);
439
440 return 0;
441}
442
443static int raw_setsockopt(struct socket *sock, int level, int optname,
444 char __user *optval, unsigned int optlen)
445{
446 struct sock *sk = sock->sk;
447 struct raw_sock *ro = raw_sk(sk);
448 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
449 struct can_filter sfilter; /* single filter */
450 struct net_device *dev = NULL;
451 can_err_mask_t err_mask = 0;
452 int count = 0;
453 int err = 0;
454
455 if (level != SOL_CAN_RAW)
456 return -EINVAL;
457
458 switch (optname) {
459
460 case CAN_RAW_FILTER:
461 if (optlen % sizeof(struct can_filter) != 0)
462 return -EINVAL;
463
464 count = optlen / sizeof(struct can_filter);
465
466 if (count > 1) {
467 /* filter does not fit into dfilter => alloc space */
468 filter = memdup_user(optval, optlen);
469 if (IS_ERR(filter))
470 return PTR_ERR(filter);
471 } else if (count == 1) {
472 if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
473 return -EFAULT;
474 }
475
476 lock_sock(sk);
477
478 if (ro->bound && ro->ifindex)
479 dev = dev_get_by_index(&init_net, ro->ifindex);
480
481 if (ro->bound) {
482 /* (try to) register the new filters */
483 if (count == 1)
484 err = raw_enable_filters(dev, sk, &sfilter, 1);
485 else
486 err = raw_enable_filters(dev, sk, filter,
487 count);
488 if (err) {
489 if (count > 1)
490 kfree(filter);
491 goto out_fil;
492 }
493
494 /* remove old filter registrations */
495 raw_disable_filters(dev, sk, ro->filter, ro->count);
496 }
497
498 /* remove old filter space */
499 if (ro->count > 1)
500 kfree(ro->filter);
501
502 /* link new filters to the socket */
503 if (count == 1) {
504 /* copy filter data for single filter */
505 ro->dfilter = sfilter;
506 filter = &ro->dfilter;
507 }
508 ro->filter = filter;
509 ro->count = count;
510
511 out_fil:
512 if (dev)
513 dev_put(dev);
514
515 release_sock(sk);
516
517 break;
518
519 case CAN_RAW_ERR_FILTER:
520 if (optlen != sizeof(err_mask))
521 return -EINVAL;
522
523 if (copy_from_user(&err_mask, optval, optlen))
524 return -EFAULT;
525
526 err_mask &= CAN_ERR_MASK;
527
528 lock_sock(sk);
529
530 if (ro->bound && ro->ifindex)
531 dev = dev_get_by_index(&init_net, ro->ifindex);
532
533 /* remove current error mask */
534 if (ro->bound) {
535 /* (try to) register the new err_mask */
536 err = raw_enable_errfilter(dev, sk, err_mask);
537
538 if (err)
539 goto out_err;
540
541 /* remove old err_mask registration */
542 raw_disable_errfilter(dev, sk, ro->err_mask);
543 }
544
545 /* link new err_mask to the socket */
546 ro->err_mask = err_mask;
547
548 out_err:
549 if (dev)
550 dev_put(dev);
551
552 release_sock(sk);
553
554 break;
555
556 case CAN_RAW_LOOPBACK:
557 if (optlen != sizeof(ro->loopback))
558 return -EINVAL;
559
560 if (copy_from_user(&ro->loopback, optval, optlen))
561 return -EFAULT;
562
563 break;
564
565 case CAN_RAW_RECV_OWN_MSGS:
566 if (optlen != sizeof(ro->recv_own_msgs))
567 return -EINVAL;
568
569 if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
570 return -EFAULT;
571
572 break;
573
574 default:
575 return -ENOPROTOOPT;
576 }
577 return err;
578}
579
580static int raw_getsockopt(struct socket *sock, int level, int optname,
581 char __user *optval, int __user *optlen)
582{
583 struct sock *sk = sock->sk;
584 struct raw_sock *ro = raw_sk(sk);
585 int len;
586 void *val;
587 int err = 0;
588
589 if (level != SOL_CAN_RAW)
590 return -EINVAL;
591 if (get_user(len, optlen))
592 return -EFAULT;
593 if (len < 0)
594 return -EINVAL;
595
596 switch (optname) {
597
598 case CAN_RAW_FILTER:
599 lock_sock(sk);
600 if (ro->count > 0) {
601 int fsize = ro->count * sizeof(struct can_filter);
602 if (len > fsize)
603 len = fsize;
604 if (copy_to_user(optval, ro->filter, len))
605 err = -EFAULT;
606 } else
607 len = 0;
608 release_sock(sk);
609
610 if (!err)
611 err = put_user(len, optlen);
612 return err;
613
614 case CAN_RAW_ERR_FILTER:
615 if (len > sizeof(can_err_mask_t))
616 len = sizeof(can_err_mask_t);
617 val = &ro->err_mask;
618 break;
619
620 case CAN_RAW_LOOPBACK:
621 if (len > sizeof(int))
622 len = sizeof(int);
623 val = &ro->loopback;
624 break;
625
626 case CAN_RAW_RECV_OWN_MSGS:
627 if (len > sizeof(int))
628 len = sizeof(int);
629 val = &ro->recv_own_msgs;
630 break;
631
632 default:
633 return -ENOPROTOOPT;
634 }
635
636 if (put_user(len, optlen))
637 return -EFAULT;
638 if (copy_to_user(optval, val, len))
639 return -EFAULT;
640 return 0;
641}
642
643static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
644 struct msghdr *msg, size_t size)
645{
646 struct sock *sk = sock->sk;
647 struct raw_sock *ro = raw_sk(sk);
648 struct sk_buff *skb;
649 struct net_device *dev;
650 int ifindex;
651 int err;
652
653 if (msg->msg_name) {
654 struct sockaddr_can *addr =
655 (struct sockaddr_can *)msg->msg_name;
656
657 if (msg->msg_namelen < sizeof(*addr))
658 return -EINVAL;
659
660 if (addr->can_family != AF_CAN)
661 return -EINVAL;
662
663 ifindex = addr->can_ifindex;
664 } else
665 ifindex = ro->ifindex;
666
667 if (size != sizeof(struct can_frame))
668 return -EINVAL;
669
670 dev = dev_get_by_index(&init_net, ifindex);
671 if (!dev)
672 return -ENXIO;
673
674 skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
675 &err);
676 if (!skb)
677 goto put_dev;
678
679 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
680 if (err < 0)
681 goto free_skb;
682 err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
683 if (err < 0)
684 goto free_skb;
685
686 /* to be able to check the received tx sock reference in raw_rcv() */
687 skb_shinfo(skb)->tx_flags |= SKBTX_DRV_NEEDS_SK_REF;
688
689 skb->dev = dev;
690 skb->sk = sk;
691
692 err = can_send(skb, ro->loopback);
693
694 dev_put(dev);
695
696 if (err)
697 goto send_failed;
698
699 return size;
700
701free_skb:
702 kfree_skb(skb);
703put_dev:
704 dev_put(dev);
705send_failed:
706 return err;
707}
708
709static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
710 struct msghdr *msg, size_t size, int flags)
711{
712 struct sock *sk = sock->sk;
713 struct sk_buff *skb;
714 int err = 0;
715 int noblock;
716
717 noblock = flags & MSG_DONTWAIT;
718 flags &= ~MSG_DONTWAIT;
719
720 skb = skb_recv_datagram(sk, flags, noblock, &err);
721 if (!skb)
722 return err;
723
724 if (size < skb->len)
725 msg->msg_flags |= MSG_TRUNC;
726 else
727 size = skb->len;
728
729 err = memcpy_toiovec(msg->msg_iov, skb->data, size);
730 if (err < 0) {
731 skb_free_datagram(sk, skb);
732 return err;
733 }
734
735 sock_recv_ts_and_drops(msg, sk, skb);
736
737 if (msg->msg_name) {
738 msg->msg_namelen = sizeof(struct sockaddr_can);
739 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
740 }
741
742 /* assign the flags that have been recorded in raw_rcv() */
743 msg->msg_flags |= *(raw_flags(skb));
744
745 skb_free_datagram(sk, skb);
746
747 return size;
748}
749
750static const struct proto_ops raw_ops = {
751 .family = PF_CAN,
752 .release = raw_release,
753 .bind = raw_bind,
754 .connect = sock_no_connect,
755 .socketpair = sock_no_socketpair,
756 .accept = sock_no_accept,
757 .getname = raw_getname,
758 .poll = datagram_poll,
759 .ioctl = can_ioctl, /* use can_ioctl() from af_can.c */
760 .listen = sock_no_listen,
761 .shutdown = sock_no_shutdown,
762 .setsockopt = raw_setsockopt,
763 .getsockopt = raw_getsockopt,
764 .sendmsg = raw_sendmsg,
765 .recvmsg = raw_recvmsg,
766 .mmap = sock_no_mmap,
767 .sendpage = sock_no_sendpage,
768};
769
770static struct proto raw_proto __read_mostly = {
771 .name = "CAN_RAW",
772 .owner = THIS_MODULE,
773 .obj_size = sizeof(struct raw_sock),
774 .init = raw_init,
775};
776
777static const struct can_proto raw_can_proto = {
778 .type = SOCK_RAW,
779 .protocol = CAN_RAW,
780 .ops = &raw_ops,
781 .prot = &raw_proto,
782};
783
784static __init int raw_module_init(void)
785{
786 int err;
787
788 printk(banner);
789
790 err = can_proto_register(&raw_can_proto);
791 if (err < 0)
792 printk(KERN_ERR "can: registration of raw protocol failed\n");
793
794 return err;
795}
796
797static __exit void raw_module_exit(void)
798{
799 can_proto_unregister(&raw_can_proto);
800}
801
802module_init(raw_module_init);
803module_exit(raw_module_exit);
1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
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 */
41
42#include <linux/module.h>
43#include <linux/init.h>
44#include <linux/uio.h>
45#include <linux/net.h>
46#include <linux/slab.h>
47#include <linux/netdevice.h>
48#include <linux/socket.h>
49#include <linux/if_arp.h>
50#include <linux/skbuff.h>
51#include <linux/can.h>
52#include <linux/can/core.h>
53#include <linux/can/skb.h>
54#include <linux/can/raw.h>
55#include <net/sock.h>
56#include <net/net_namespace.h>
57
58MODULE_DESCRIPTION("PF_CAN raw protocol");
59MODULE_LICENSE("Dual BSD/GPL");
60MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
61MODULE_ALIAS("can-proto-1");
62
63#define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
64
65#define MASK_ALL 0
66
67/* A raw socket has a list of can_filters attached to it, each receiving
68 * the CAN frames matching that filter. If the filter list is empty,
69 * no CAN frames will be received by the socket. The default after
70 * opening the socket, is to have one filter which receives all frames.
71 * The filter list is allocated dynamically with the exception of the
72 * list containing only one item. This common case is optimized by
73 * storing the single filter in dfilter, to avoid using dynamic memory.
74 */
75
76struct uniqframe {
77 int skbcnt;
78 const struct sk_buff *skb;
79 unsigned int join_rx_count;
80};
81
82struct raw_sock {
83 struct sock sk;
84 int bound;
85 int ifindex;
86 struct list_head notifier;
87 int loopback;
88 int recv_own_msgs;
89 int fd_frames;
90 int join_filters;
91 int count; /* number of active filters */
92 struct can_filter dfilter; /* default/single filter */
93 struct can_filter *filter; /* pointer to filter(s) */
94 can_err_mask_t err_mask;
95 struct uniqframe __percpu *uniq;
96};
97
98static LIST_HEAD(raw_notifier_list);
99static DEFINE_SPINLOCK(raw_notifier_lock);
100static struct raw_sock *raw_busy_notifier;
101
102/* Return pointer to store the extra msg flags for raw_recvmsg().
103 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
104 * in skb->cb.
105 */
106static inline unsigned int *raw_flags(struct sk_buff *skb)
107{
108 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
109 sizeof(unsigned int));
110
111 /* return pointer after struct sockaddr_can */
112 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
113}
114
115static inline struct raw_sock *raw_sk(const struct sock *sk)
116{
117 return (struct raw_sock *)sk;
118}
119
120static void raw_rcv(struct sk_buff *oskb, void *data)
121{
122 struct sock *sk = (struct sock *)data;
123 struct raw_sock *ro = raw_sk(sk);
124 struct sockaddr_can *addr;
125 struct sk_buff *skb;
126 unsigned int *pflags;
127
128 /* check the received tx sock reference */
129 if (!ro->recv_own_msgs && oskb->sk == sk)
130 return;
131
132 /* do not pass non-CAN2.0 frames to a legacy socket */
133 if (!ro->fd_frames && oskb->len != CAN_MTU)
134 return;
135
136 /* eliminate multiple filter matches for the same skb */
137 if (this_cpu_ptr(ro->uniq)->skb == oskb &&
138 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
139 if (ro->join_filters) {
140 this_cpu_inc(ro->uniq->join_rx_count);
141 /* drop frame until all enabled filters matched */
142 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
143 return;
144 } else {
145 return;
146 }
147 } else {
148 this_cpu_ptr(ro->uniq)->skb = oskb;
149 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
150 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
151 /* drop first frame to check all enabled filters? */
152 if (ro->join_filters && ro->count > 1)
153 return;
154 }
155
156 /* clone the given skb to be able to enqueue it into the rcv queue */
157 skb = skb_clone(oskb, GFP_ATOMIC);
158 if (!skb)
159 return;
160
161 /* Put the datagram to the queue so that raw_recvmsg() can get
162 * it from there. We need to pass the interface index to
163 * raw_recvmsg(). We pass a whole struct sockaddr_can in
164 * skb->cb containing the interface index.
165 */
166
167 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
168 addr = (struct sockaddr_can *)skb->cb;
169 memset(addr, 0, sizeof(*addr));
170 addr->can_family = AF_CAN;
171 addr->can_ifindex = skb->dev->ifindex;
172
173 /* add CAN specific message flags for raw_recvmsg() */
174 pflags = raw_flags(skb);
175 *pflags = 0;
176 if (oskb->sk)
177 *pflags |= MSG_DONTROUTE;
178 if (oskb->sk == sk)
179 *pflags |= MSG_CONFIRM;
180
181 if (sock_queue_rcv_skb(sk, skb) < 0)
182 kfree_skb(skb);
183}
184
185static int raw_enable_filters(struct net *net, struct net_device *dev,
186 struct sock *sk, struct can_filter *filter,
187 int count)
188{
189 int err = 0;
190 int i;
191
192 for (i = 0; i < count; i++) {
193 err = can_rx_register(net, dev, filter[i].can_id,
194 filter[i].can_mask,
195 raw_rcv, sk, "raw", sk);
196 if (err) {
197 /* clean up successfully registered filters */
198 while (--i >= 0)
199 can_rx_unregister(net, dev, filter[i].can_id,
200 filter[i].can_mask,
201 raw_rcv, sk);
202 break;
203 }
204 }
205
206 return err;
207}
208
209static int raw_enable_errfilter(struct net *net, struct net_device *dev,
210 struct sock *sk, can_err_mask_t err_mask)
211{
212 int err = 0;
213
214 if (err_mask)
215 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
216 raw_rcv, sk, "raw", sk);
217
218 return err;
219}
220
221static void raw_disable_filters(struct net *net, struct net_device *dev,
222 struct sock *sk, struct can_filter *filter,
223 int count)
224{
225 int i;
226
227 for (i = 0; i < count; i++)
228 can_rx_unregister(net, dev, filter[i].can_id,
229 filter[i].can_mask, raw_rcv, sk);
230}
231
232static inline void raw_disable_errfilter(struct net *net,
233 struct net_device *dev,
234 struct sock *sk,
235 can_err_mask_t err_mask)
236
237{
238 if (err_mask)
239 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
240 raw_rcv, sk);
241}
242
243static inline void raw_disable_allfilters(struct net *net,
244 struct net_device *dev,
245 struct sock *sk)
246{
247 struct raw_sock *ro = raw_sk(sk);
248
249 raw_disable_filters(net, dev, sk, ro->filter, ro->count);
250 raw_disable_errfilter(net, dev, sk, ro->err_mask);
251}
252
253static int raw_enable_allfilters(struct net *net, struct net_device *dev,
254 struct sock *sk)
255{
256 struct raw_sock *ro = raw_sk(sk);
257 int err;
258
259 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
260 if (!err) {
261 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
262 if (err)
263 raw_disable_filters(net, dev, sk, ro->filter,
264 ro->count);
265 }
266
267 return err;
268}
269
270static void raw_notify(struct raw_sock *ro, unsigned long msg,
271 struct net_device *dev)
272{
273 struct sock *sk = &ro->sk;
274
275 if (!net_eq(dev_net(dev), sock_net(sk)))
276 return;
277
278 if (ro->ifindex != dev->ifindex)
279 return;
280
281 switch (msg) {
282 case NETDEV_UNREGISTER:
283 lock_sock(sk);
284 /* remove current filters & unregister */
285 if (ro->bound)
286 raw_disable_allfilters(dev_net(dev), dev, sk);
287
288 if (ro->count > 1)
289 kfree(ro->filter);
290
291 ro->ifindex = 0;
292 ro->bound = 0;
293 ro->count = 0;
294 release_sock(sk);
295
296 sk->sk_err = ENODEV;
297 if (!sock_flag(sk, SOCK_DEAD))
298 sk_error_report(sk);
299 break;
300
301 case NETDEV_DOWN:
302 sk->sk_err = ENETDOWN;
303 if (!sock_flag(sk, SOCK_DEAD))
304 sk_error_report(sk);
305 break;
306 }
307}
308
309static int raw_notifier(struct notifier_block *nb, unsigned long msg,
310 void *ptr)
311{
312 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
313
314 if (dev->type != ARPHRD_CAN)
315 return NOTIFY_DONE;
316 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
317 return NOTIFY_DONE;
318 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
319 return NOTIFY_DONE;
320
321 spin_lock(&raw_notifier_lock);
322 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
323 spin_unlock(&raw_notifier_lock);
324 raw_notify(raw_busy_notifier, msg, dev);
325 spin_lock(&raw_notifier_lock);
326 }
327 raw_busy_notifier = NULL;
328 spin_unlock(&raw_notifier_lock);
329 return NOTIFY_DONE;
330}
331
332static int raw_init(struct sock *sk)
333{
334 struct raw_sock *ro = raw_sk(sk);
335
336 ro->bound = 0;
337 ro->ifindex = 0;
338
339 /* set default filter to single entry dfilter */
340 ro->dfilter.can_id = 0;
341 ro->dfilter.can_mask = MASK_ALL;
342 ro->filter = &ro->dfilter;
343 ro->count = 1;
344
345 /* set default loopback behaviour */
346 ro->loopback = 1;
347 ro->recv_own_msgs = 0;
348 ro->fd_frames = 0;
349 ro->join_filters = 0;
350
351 /* alloc_percpu provides zero'ed memory */
352 ro->uniq = alloc_percpu(struct uniqframe);
353 if (unlikely(!ro->uniq))
354 return -ENOMEM;
355
356 /* set notifier */
357 spin_lock(&raw_notifier_lock);
358 list_add_tail(&ro->notifier, &raw_notifier_list);
359 spin_unlock(&raw_notifier_lock);
360
361 return 0;
362}
363
364static int raw_release(struct socket *sock)
365{
366 struct sock *sk = sock->sk;
367 struct raw_sock *ro;
368
369 if (!sk)
370 return 0;
371
372 ro = raw_sk(sk);
373
374 spin_lock(&raw_notifier_lock);
375 while (raw_busy_notifier == ro) {
376 spin_unlock(&raw_notifier_lock);
377 schedule_timeout_uninterruptible(1);
378 spin_lock(&raw_notifier_lock);
379 }
380 list_del(&ro->notifier);
381 spin_unlock(&raw_notifier_lock);
382
383 lock_sock(sk);
384
385 /* remove current filters & unregister */
386 if (ro->bound) {
387 if (ro->ifindex) {
388 struct net_device *dev;
389
390 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
391 if (dev) {
392 raw_disable_allfilters(dev_net(dev), dev, sk);
393 dev_put(dev);
394 }
395 } else {
396 raw_disable_allfilters(sock_net(sk), NULL, sk);
397 }
398 }
399
400 if (ro->count > 1)
401 kfree(ro->filter);
402
403 ro->ifindex = 0;
404 ro->bound = 0;
405 ro->count = 0;
406 free_percpu(ro->uniq);
407
408 sock_orphan(sk);
409 sock->sk = NULL;
410
411 release_sock(sk);
412 sock_put(sk);
413
414 return 0;
415}
416
417static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
418{
419 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
420 struct sock *sk = sock->sk;
421 struct raw_sock *ro = raw_sk(sk);
422 int ifindex;
423 int err = 0;
424 int notify_enetdown = 0;
425
426 if (len < RAW_MIN_NAMELEN)
427 return -EINVAL;
428 if (addr->can_family != AF_CAN)
429 return -EINVAL;
430
431 lock_sock(sk);
432
433 if (ro->bound && addr->can_ifindex == ro->ifindex)
434 goto out;
435
436 if (addr->can_ifindex) {
437 struct net_device *dev;
438
439 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
440 if (!dev) {
441 err = -ENODEV;
442 goto out;
443 }
444 if (dev->type != ARPHRD_CAN) {
445 dev_put(dev);
446 err = -ENODEV;
447 goto out;
448 }
449 if (!(dev->flags & IFF_UP))
450 notify_enetdown = 1;
451
452 ifindex = dev->ifindex;
453
454 /* filters set by default/setsockopt */
455 err = raw_enable_allfilters(sock_net(sk), dev, sk);
456 dev_put(dev);
457 } else {
458 ifindex = 0;
459
460 /* filters set by default/setsockopt */
461 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
462 }
463
464 if (!err) {
465 if (ro->bound) {
466 /* unregister old filters */
467 if (ro->ifindex) {
468 struct net_device *dev;
469
470 dev = dev_get_by_index(sock_net(sk),
471 ro->ifindex);
472 if (dev) {
473 raw_disable_allfilters(dev_net(dev),
474 dev, sk);
475 dev_put(dev);
476 }
477 } else {
478 raw_disable_allfilters(sock_net(sk), NULL, sk);
479 }
480 }
481 ro->ifindex = ifindex;
482 ro->bound = 1;
483 }
484
485 out:
486 release_sock(sk);
487
488 if (notify_enetdown) {
489 sk->sk_err = ENETDOWN;
490 if (!sock_flag(sk, SOCK_DEAD))
491 sk_error_report(sk);
492 }
493
494 return err;
495}
496
497static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
498 int peer)
499{
500 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
501 struct sock *sk = sock->sk;
502 struct raw_sock *ro = raw_sk(sk);
503
504 if (peer)
505 return -EOPNOTSUPP;
506
507 memset(addr, 0, RAW_MIN_NAMELEN);
508 addr->can_family = AF_CAN;
509 addr->can_ifindex = ro->ifindex;
510
511 return RAW_MIN_NAMELEN;
512}
513
514static int raw_setsockopt(struct socket *sock, int level, int optname,
515 sockptr_t optval, unsigned int optlen)
516{
517 struct sock *sk = sock->sk;
518 struct raw_sock *ro = raw_sk(sk);
519 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
520 struct can_filter sfilter; /* single filter */
521 struct net_device *dev = NULL;
522 can_err_mask_t err_mask = 0;
523 int count = 0;
524 int err = 0;
525
526 if (level != SOL_CAN_RAW)
527 return -EINVAL;
528
529 switch (optname) {
530 case CAN_RAW_FILTER:
531 if (optlen % sizeof(struct can_filter) != 0)
532 return -EINVAL;
533
534 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
535 return -EINVAL;
536
537 count = optlen / sizeof(struct can_filter);
538
539 if (count > 1) {
540 /* filter does not fit into dfilter => alloc space */
541 filter = memdup_sockptr(optval, optlen);
542 if (IS_ERR(filter))
543 return PTR_ERR(filter);
544 } else if (count == 1) {
545 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter)))
546 return -EFAULT;
547 }
548
549 rtnl_lock();
550 lock_sock(sk);
551
552 if (ro->bound && ro->ifindex) {
553 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
554 if (!dev) {
555 if (count > 1)
556 kfree(filter);
557 err = -ENODEV;
558 goto out_fil;
559 }
560 }
561
562 if (ro->bound) {
563 /* (try to) register the new filters */
564 if (count == 1)
565 err = raw_enable_filters(sock_net(sk), dev, sk,
566 &sfilter, 1);
567 else
568 err = raw_enable_filters(sock_net(sk), dev, sk,
569 filter, count);
570 if (err) {
571 if (count > 1)
572 kfree(filter);
573 goto out_fil;
574 }
575
576 /* remove old filter registrations */
577 raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
578 ro->count);
579 }
580
581 /* remove old filter space */
582 if (ro->count > 1)
583 kfree(ro->filter);
584
585 /* link new filters to the socket */
586 if (count == 1) {
587 /* copy filter data for single filter */
588 ro->dfilter = sfilter;
589 filter = &ro->dfilter;
590 }
591 ro->filter = filter;
592 ro->count = count;
593
594 out_fil:
595 if (dev)
596 dev_put(dev);
597
598 release_sock(sk);
599 rtnl_unlock();
600
601 break;
602
603 case CAN_RAW_ERR_FILTER:
604 if (optlen != sizeof(err_mask))
605 return -EINVAL;
606
607 if (copy_from_sockptr(&err_mask, optval, optlen))
608 return -EFAULT;
609
610 err_mask &= CAN_ERR_MASK;
611
612 rtnl_lock();
613 lock_sock(sk);
614
615 if (ro->bound && ro->ifindex) {
616 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
617 if (!dev) {
618 err = -ENODEV;
619 goto out_err;
620 }
621 }
622
623 /* remove current error mask */
624 if (ro->bound) {
625 /* (try to) register the new err_mask */
626 err = raw_enable_errfilter(sock_net(sk), dev, sk,
627 err_mask);
628
629 if (err)
630 goto out_err;
631
632 /* remove old err_mask registration */
633 raw_disable_errfilter(sock_net(sk), dev, sk,
634 ro->err_mask);
635 }
636
637 /* link new err_mask to the socket */
638 ro->err_mask = err_mask;
639
640 out_err:
641 if (dev)
642 dev_put(dev);
643
644 release_sock(sk);
645 rtnl_unlock();
646
647 break;
648
649 case CAN_RAW_LOOPBACK:
650 if (optlen != sizeof(ro->loopback))
651 return -EINVAL;
652
653 if (copy_from_sockptr(&ro->loopback, optval, optlen))
654 return -EFAULT;
655
656 break;
657
658 case CAN_RAW_RECV_OWN_MSGS:
659 if (optlen != sizeof(ro->recv_own_msgs))
660 return -EINVAL;
661
662 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen))
663 return -EFAULT;
664
665 break;
666
667 case CAN_RAW_FD_FRAMES:
668 if (optlen != sizeof(ro->fd_frames))
669 return -EINVAL;
670
671 if (copy_from_sockptr(&ro->fd_frames, optval, optlen))
672 return -EFAULT;
673
674 break;
675
676 case CAN_RAW_JOIN_FILTERS:
677 if (optlen != sizeof(ro->join_filters))
678 return -EINVAL;
679
680 if (copy_from_sockptr(&ro->join_filters, optval, optlen))
681 return -EFAULT;
682
683 break;
684
685 default:
686 return -ENOPROTOOPT;
687 }
688 return err;
689}
690
691static int raw_getsockopt(struct socket *sock, int level, int optname,
692 char __user *optval, int __user *optlen)
693{
694 struct sock *sk = sock->sk;
695 struct raw_sock *ro = raw_sk(sk);
696 int len;
697 void *val;
698 int err = 0;
699
700 if (level != SOL_CAN_RAW)
701 return -EINVAL;
702 if (get_user(len, optlen))
703 return -EFAULT;
704 if (len < 0)
705 return -EINVAL;
706
707 switch (optname) {
708 case CAN_RAW_FILTER:
709 lock_sock(sk);
710 if (ro->count > 0) {
711 int fsize = ro->count * sizeof(struct can_filter);
712
713 /* user space buffer to small for filter list? */
714 if (len < fsize) {
715 /* return -ERANGE and needed space in optlen */
716 err = -ERANGE;
717 if (put_user(fsize, optlen))
718 err = -EFAULT;
719 } else {
720 if (len > fsize)
721 len = fsize;
722 if (copy_to_user(optval, ro->filter, len))
723 err = -EFAULT;
724 }
725 } else {
726 len = 0;
727 }
728 release_sock(sk);
729
730 if (!err)
731 err = put_user(len, optlen);
732 return err;
733
734 case CAN_RAW_ERR_FILTER:
735 if (len > sizeof(can_err_mask_t))
736 len = sizeof(can_err_mask_t);
737 val = &ro->err_mask;
738 break;
739
740 case CAN_RAW_LOOPBACK:
741 if (len > sizeof(int))
742 len = sizeof(int);
743 val = &ro->loopback;
744 break;
745
746 case CAN_RAW_RECV_OWN_MSGS:
747 if (len > sizeof(int))
748 len = sizeof(int);
749 val = &ro->recv_own_msgs;
750 break;
751
752 case CAN_RAW_FD_FRAMES:
753 if (len > sizeof(int))
754 len = sizeof(int);
755 val = &ro->fd_frames;
756 break;
757
758 case CAN_RAW_JOIN_FILTERS:
759 if (len > sizeof(int))
760 len = sizeof(int);
761 val = &ro->join_filters;
762 break;
763
764 default:
765 return -ENOPROTOOPT;
766 }
767
768 if (put_user(len, optlen))
769 return -EFAULT;
770 if (copy_to_user(optval, val, len))
771 return -EFAULT;
772 return 0;
773}
774
775static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
776{
777 struct sock *sk = sock->sk;
778 struct raw_sock *ro = raw_sk(sk);
779 struct sk_buff *skb;
780 struct net_device *dev;
781 int ifindex;
782 int err;
783
784 if (msg->msg_name) {
785 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
786
787 if (msg->msg_namelen < RAW_MIN_NAMELEN)
788 return -EINVAL;
789
790 if (addr->can_family != AF_CAN)
791 return -EINVAL;
792
793 ifindex = addr->can_ifindex;
794 } else {
795 ifindex = ro->ifindex;
796 }
797
798 dev = dev_get_by_index(sock_net(sk), ifindex);
799 if (!dev)
800 return -ENXIO;
801
802 err = -EINVAL;
803 if (ro->fd_frames && dev->mtu == CANFD_MTU) {
804 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
805 goto put_dev;
806 } else {
807 if (unlikely(size != CAN_MTU))
808 goto put_dev;
809 }
810
811 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
812 msg->msg_flags & MSG_DONTWAIT, &err);
813 if (!skb)
814 goto put_dev;
815
816 can_skb_reserve(skb);
817 can_skb_prv(skb)->ifindex = dev->ifindex;
818 can_skb_prv(skb)->skbcnt = 0;
819
820 err = memcpy_from_msg(skb_put(skb, size), msg, size);
821 if (err < 0)
822 goto free_skb;
823
824 skb_setup_tx_timestamp(skb, sk->sk_tsflags);
825
826 skb->dev = dev;
827 skb->sk = sk;
828 skb->priority = sk->sk_priority;
829
830 err = can_send(skb, ro->loopback);
831
832 dev_put(dev);
833
834 if (err)
835 goto send_failed;
836
837 return size;
838
839free_skb:
840 kfree_skb(skb);
841put_dev:
842 dev_put(dev);
843send_failed:
844 return err;
845}
846
847static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
848 int flags)
849{
850 struct sock *sk = sock->sk;
851 struct sk_buff *skb;
852 int err = 0;
853 int noblock;
854
855 noblock = flags & MSG_DONTWAIT;
856 flags &= ~MSG_DONTWAIT;
857
858 if (flags & MSG_ERRQUEUE)
859 return sock_recv_errqueue(sk, msg, size,
860 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
861
862 skb = skb_recv_datagram(sk, flags, noblock, &err);
863 if (!skb)
864 return err;
865
866 if (size < skb->len)
867 msg->msg_flags |= MSG_TRUNC;
868 else
869 size = skb->len;
870
871 err = memcpy_to_msg(msg, skb->data, size);
872 if (err < 0) {
873 skb_free_datagram(sk, skb);
874 return err;
875 }
876
877 sock_recv_ts_and_drops(msg, sk, skb);
878
879 if (msg->msg_name) {
880 __sockaddr_check_size(RAW_MIN_NAMELEN);
881 msg->msg_namelen = RAW_MIN_NAMELEN;
882 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
883 }
884
885 /* assign the flags that have been recorded in raw_rcv() */
886 msg->msg_flags |= *(raw_flags(skb));
887
888 skb_free_datagram(sk, skb);
889
890 return size;
891}
892
893static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
894 unsigned long arg)
895{
896 /* no ioctls for socket layer -> hand it down to NIC layer */
897 return -ENOIOCTLCMD;
898}
899
900static const struct proto_ops raw_ops = {
901 .family = PF_CAN,
902 .release = raw_release,
903 .bind = raw_bind,
904 .connect = sock_no_connect,
905 .socketpair = sock_no_socketpair,
906 .accept = sock_no_accept,
907 .getname = raw_getname,
908 .poll = datagram_poll,
909 .ioctl = raw_sock_no_ioctlcmd,
910 .gettstamp = sock_gettstamp,
911 .listen = sock_no_listen,
912 .shutdown = sock_no_shutdown,
913 .setsockopt = raw_setsockopt,
914 .getsockopt = raw_getsockopt,
915 .sendmsg = raw_sendmsg,
916 .recvmsg = raw_recvmsg,
917 .mmap = sock_no_mmap,
918 .sendpage = sock_no_sendpage,
919};
920
921static struct proto raw_proto __read_mostly = {
922 .name = "CAN_RAW",
923 .owner = THIS_MODULE,
924 .obj_size = sizeof(struct raw_sock),
925 .init = raw_init,
926};
927
928static const struct can_proto raw_can_proto = {
929 .type = SOCK_RAW,
930 .protocol = CAN_RAW,
931 .ops = &raw_ops,
932 .prot = &raw_proto,
933};
934
935static struct notifier_block canraw_notifier = {
936 .notifier_call = raw_notifier
937};
938
939static __init int raw_module_init(void)
940{
941 int err;
942
943 pr_info("can: raw protocol\n");
944
945 err = can_proto_register(&raw_can_proto);
946 if (err < 0)
947 pr_err("can: registration of raw protocol failed\n");
948 else
949 register_netdevice_notifier(&canraw_notifier);
950
951 return err;
952}
953
954static __exit void raw_module_exit(void)
955{
956 can_proto_unregister(&raw_can_proto);
957 unregister_netdevice_notifier(&canraw_notifier);
958}
959
960module_init(raw_module_init);
961module_exit(raw_module_exit);