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