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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 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/dev.h> /* for can_is_canxl_dev_mtu() */
54#include <linux/can/skb.h>
55#include <linux/can/raw.h>
56#include <net/sock.h>
57#include <net/net_namespace.h>
58
59MODULE_DESCRIPTION("PF_CAN raw protocol");
60MODULE_LICENSE("Dual BSD/GPL");
61MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
62MODULE_ALIAS("can-proto-1");
63
64#define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
65
66#define MASK_ALL 0
67
68/* A raw socket has a list of can_filters attached to it, each receiving
69 * the CAN frames matching that filter. If the filter list is empty,
70 * no CAN frames will be received by the socket. The default after
71 * opening the socket, is to have one filter which receives all frames.
72 * The filter list is allocated dynamically with the exception of the
73 * list containing only one item. This common case is optimized by
74 * storing the single filter in dfilter, to avoid using dynamic memory.
75 */
76
77struct uniqframe {
78 int skbcnt;
79 const struct sk_buff *skb;
80 unsigned int join_rx_count;
81};
82
83struct raw_sock {
84 struct sock sk;
85 int bound;
86 int ifindex;
87 struct net_device *dev;
88 netdevice_tracker dev_tracker;
89 struct list_head notifier;
90 int loopback;
91 int recv_own_msgs;
92 int fd_frames;
93 int xl_frames;
94 int join_filters;
95 int count; /* number of active filters */
96 struct can_filter dfilter; /* default/single filter */
97 struct can_filter *filter; /* pointer to filter(s) */
98 can_err_mask_t err_mask;
99 struct uniqframe __percpu *uniq;
100};
101
102static LIST_HEAD(raw_notifier_list);
103static DEFINE_SPINLOCK(raw_notifier_lock);
104static struct raw_sock *raw_busy_notifier;
105
106/* Return pointer to store the extra msg flags for raw_recvmsg().
107 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
108 * in skb->cb.
109 */
110static inline unsigned int *raw_flags(struct sk_buff *skb)
111{
112 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
113 sizeof(unsigned int));
114
115 /* return pointer after struct sockaddr_can */
116 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
117}
118
119static inline struct raw_sock *raw_sk(const struct sock *sk)
120{
121 return (struct raw_sock *)sk;
122}
123
124static void raw_rcv(struct sk_buff *oskb, void *data)
125{
126 struct sock *sk = (struct sock *)data;
127 struct raw_sock *ro = raw_sk(sk);
128 struct sockaddr_can *addr;
129 struct sk_buff *skb;
130 unsigned int *pflags;
131
132 /* check the received tx sock reference */
133 if (!ro->recv_own_msgs && oskb->sk == sk)
134 return;
135
136 /* make sure to not pass oversized frames to the socket */
137 if ((!ro->fd_frames && can_is_canfd_skb(oskb)) ||
138 (!ro->xl_frames && can_is_canxl_skb(oskb)))
139 return;
140
141 /* eliminate multiple filter matches for the same skb */
142 if (this_cpu_ptr(ro->uniq)->skb == oskb &&
143 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
144 if (!ro->join_filters)
145 return;
146
147 this_cpu_inc(ro->uniq->join_rx_count);
148 /* drop frame until all enabled filters matched */
149 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
150 return;
151 } else {
152 this_cpu_ptr(ro->uniq)->skb = oskb;
153 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
154 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
155 /* drop first frame to check all enabled filters? */
156 if (ro->join_filters && ro->count > 1)
157 return;
158 }
159
160 /* clone the given skb to be able to enqueue it into the rcv queue */
161 skb = skb_clone(oskb, GFP_ATOMIC);
162 if (!skb)
163 return;
164
165 /* Put the datagram to the queue so that raw_recvmsg() can get
166 * it from there. We need to pass the interface index to
167 * raw_recvmsg(). We pass a whole struct sockaddr_can in
168 * skb->cb containing the interface index.
169 */
170
171 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
172 addr = (struct sockaddr_can *)skb->cb;
173 memset(addr, 0, sizeof(*addr));
174 addr->can_family = AF_CAN;
175 addr->can_ifindex = skb->dev->ifindex;
176
177 /* add CAN specific message flags for raw_recvmsg() */
178 pflags = raw_flags(skb);
179 *pflags = 0;
180 if (oskb->sk)
181 *pflags |= MSG_DONTROUTE;
182 if (oskb->sk == sk)
183 *pflags |= MSG_CONFIRM;
184
185 if (sock_queue_rcv_skb(sk, skb) < 0)
186 kfree_skb(skb);
187}
188
189static int raw_enable_filters(struct net *net, struct net_device *dev,
190 struct sock *sk, struct can_filter *filter,
191 int count)
192{
193 int err = 0;
194 int i;
195
196 for (i = 0; i < count; i++) {
197 err = can_rx_register(net, dev, filter[i].can_id,
198 filter[i].can_mask,
199 raw_rcv, sk, "raw", sk);
200 if (err) {
201 /* clean up successfully registered filters */
202 while (--i >= 0)
203 can_rx_unregister(net, dev, filter[i].can_id,
204 filter[i].can_mask,
205 raw_rcv, sk);
206 break;
207 }
208 }
209
210 return err;
211}
212
213static int raw_enable_errfilter(struct net *net, struct net_device *dev,
214 struct sock *sk, can_err_mask_t err_mask)
215{
216 int err = 0;
217
218 if (err_mask)
219 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
220 raw_rcv, sk, "raw", sk);
221
222 return err;
223}
224
225static void raw_disable_filters(struct net *net, struct net_device *dev,
226 struct sock *sk, struct can_filter *filter,
227 int count)
228{
229 int i;
230
231 for (i = 0; i < count; i++)
232 can_rx_unregister(net, dev, filter[i].can_id,
233 filter[i].can_mask, raw_rcv, sk);
234}
235
236static inline void raw_disable_errfilter(struct net *net,
237 struct net_device *dev,
238 struct sock *sk,
239 can_err_mask_t err_mask)
240
241{
242 if (err_mask)
243 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
244 raw_rcv, sk);
245}
246
247static inline void raw_disable_allfilters(struct net *net,
248 struct net_device *dev,
249 struct sock *sk)
250{
251 struct raw_sock *ro = raw_sk(sk);
252
253 raw_disable_filters(net, dev, sk, ro->filter, ro->count);
254 raw_disable_errfilter(net, dev, sk, ro->err_mask);
255}
256
257static int raw_enable_allfilters(struct net *net, struct net_device *dev,
258 struct sock *sk)
259{
260 struct raw_sock *ro = raw_sk(sk);
261 int err;
262
263 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
264 if (!err) {
265 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
266 if (err)
267 raw_disable_filters(net, dev, sk, ro->filter,
268 ro->count);
269 }
270
271 return err;
272}
273
274static void raw_notify(struct raw_sock *ro, unsigned long msg,
275 struct net_device *dev)
276{
277 struct sock *sk = &ro->sk;
278
279 if (!net_eq(dev_net(dev), sock_net(sk)))
280 return;
281
282 if (ro->dev != dev)
283 return;
284
285 switch (msg) {
286 case NETDEV_UNREGISTER:
287 lock_sock(sk);
288 /* remove current filters & unregister */
289 if (ro->bound) {
290 raw_disable_allfilters(dev_net(dev), dev, sk);
291 netdev_put(dev, &ro->dev_tracker);
292 }
293
294 if (ro->count > 1)
295 kfree(ro->filter);
296
297 ro->ifindex = 0;
298 ro->bound = 0;
299 ro->dev = NULL;
300 ro->count = 0;
301 release_sock(sk);
302
303 sk->sk_err = ENODEV;
304 if (!sock_flag(sk, SOCK_DEAD))
305 sk_error_report(sk);
306 break;
307
308 case NETDEV_DOWN:
309 sk->sk_err = ENETDOWN;
310 if (!sock_flag(sk, SOCK_DEAD))
311 sk_error_report(sk);
312 break;
313 }
314}
315
316static int raw_notifier(struct notifier_block *nb, unsigned long msg,
317 void *ptr)
318{
319 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
320
321 if (dev->type != ARPHRD_CAN)
322 return NOTIFY_DONE;
323 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
324 return NOTIFY_DONE;
325 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
326 return NOTIFY_DONE;
327
328 spin_lock(&raw_notifier_lock);
329 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
330 spin_unlock(&raw_notifier_lock);
331 raw_notify(raw_busy_notifier, msg, dev);
332 spin_lock(&raw_notifier_lock);
333 }
334 raw_busy_notifier = NULL;
335 spin_unlock(&raw_notifier_lock);
336 return NOTIFY_DONE;
337}
338
339static int raw_init(struct sock *sk)
340{
341 struct raw_sock *ro = raw_sk(sk);
342
343 ro->bound = 0;
344 ro->ifindex = 0;
345 ro->dev = NULL;
346
347 /* set default filter to single entry dfilter */
348 ro->dfilter.can_id = 0;
349 ro->dfilter.can_mask = MASK_ALL;
350 ro->filter = &ro->dfilter;
351 ro->count = 1;
352
353 /* set default loopback behaviour */
354 ro->loopback = 1;
355 ro->recv_own_msgs = 0;
356 ro->fd_frames = 0;
357 ro->xl_frames = 0;
358 ro->join_filters = 0;
359
360 /* alloc_percpu provides zero'ed memory */
361 ro->uniq = alloc_percpu(struct uniqframe);
362 if (unlikely(!ro->uniq))
363 return -ENOMEM;
364
365 /* set notifier */
366 spin_lock(&raw_notifier_lock);
367 list_add_tail(&ro->notifier, &raw_notifier_list);
368 spin_unlock(&raw_notifier_lock);
369
370 return 0;
371}
372
373static int raw_release(struct socket *sock)
374{
375 struct sock *sk = sock->sk;
376 struct raw_sock *ro;
377
378 if (!sk)
379 return 0;
380
381 ro = raw_sk(sk);
382
383 spin_lock(&raw_notifier_lock);
384 while (raw_busy_notifier == ro) {
385 spin_unlock(&raw_notifier_lock);
386 schedule_timeout_uninterruptible(1);
387 spin_lock(&raw_notifier_lock);
388 }
389 list_del(&ro->notifier);
390 spin_unlock(&raw_notifier_lock);
391
392 rtnl_lock();
393 lock_sock(sk);
394
395 /* remove current filters & unregister */
396 if (ro->bound) {
397 if (ro->dev) {
398 raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk);
399 netdev_put(ro->dev, &ro->dev_tracker);
400 } else {
401 raw_disable_allfilters(sock_net(sk), NULL, sk);
402 }
403 }
404
405 if (ro->count > 1)
406 kfree(ro->filter);
407
408 ro->ifindex = 0;
409 ro->bound = 0;
410 ro->dev = NULL;
411 ro->count = 0;
412 free_percpu(ro->uniq);
413
414 sock_orphan(sk);
415 sock->sk = NULL;
416
417 release_sock(sk);
418 rtnl_unlock();
419
420 sock_put(sk);
421
422 return 0;
423}
424
425static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
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 struct net_device *dev = NULL;
431 int ifindex;
432 int err = 0;
433 int notify_enetdown = 0;
434
435 if (len < RAW_MIN_NAMELEN)
436 return -EINVAL;
437 if (addr->can_family != AF_CAN)
438 return -EINVAL;
439
440 rtnl_lock();
441 lock_sock(sk);
442
443 if (ro->bound && addr->can_ifindex == ro->ifindex)
444 goto out;
445
446 if (addr->can_ifindex) {
447 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
448 if (!dev) {
449 err = -ENODEV;
450 goto out;
451 }
452 if (dev->type != ARPHRD_CAN) {
453 err = -ENODEV;
454 goto out_put_dev;
455 }
456
457 if (!(dev->flags & IFF_UP))
458 notify_enetdown = 1;
459
460 ifindex = dev->ifindex;
461
462 /* filters set by default/setsockopt */
463 err = raw_enable_allfilters(sock_net(sk), dev, sk);
464 if (err)
465 goto out_put_dev;
466
467 } else {
468 ifindex = 0;
469
470 /* filters set by default/setsockopt */
471 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
472 }
473
474 if (!err) {
475 if (ro->bound) {
476 /* unregister old filters */
477 if (ro->dev) {
478 raw_disable_allfilters(dev_net(ro->dev),
479 ro->dev, sk);
480 /* drop reference to old ro->dev */
481 netdev_put(ro->dev, &ro->dev_tracker);
482 } else {
483 raw_disable_allfilters(sock_net(sk), NULL, sk);
484 }
485 }
486 ro->ifindex = ifindex;
487 ro->bound = 1;
488 /* bind() ok -> hold a reference for new ro->dev */
489 ro->dev = dev;
490 if (ro->dev)
491 netdev_hold(ro->dev, &ro->dev_tracker, GFP_KERNEL);
492 }
493
494out_put_dev:
495 /* remove potential reference from dev_get_by_index() */
496 dev_put(dev);
497out:
498 release_sock(sk);
499 rtnl_unlock();
500
501 if (notify_enetdown) {
502 sk->sk_err = ENETDOWN;
503 if (!sock_flag(sk, SOCK_DEAD))
504 sk_error_report(sk);
505 }
506
507 return err;
508}
509
510static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
511 int peer)
512{
513 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
514 struct sock *sk = sock->sk;
515 struct raw_sock *ro = raw_sk(sk);
516
517 if (peer)
518 return -EOPNOTSUPP;
519
520 memset(addr, 0, RAW_MIN_NAMELEN);
521 addr->can_family = AF_CAN;
522 addr->can_ifindex = ro->ifindex;
523
524 return RAW_MIN_NAMELEN;
525}
526
527static int raw_setsockopt(struct socket *sock, int level, int optname,
528 sockptr_t optval, unsigned int optlen)
529{
530 struct sock *sk = sock->sk;
531 struct raw_sock *ro = raw_sk(sk);
532 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
533 struct can_filter sfilter; /* single filter */
534 struct net_device *dev = NULL;
535 can_err_mask_t err_mask = 0;
536 int fd_frames;
537 int count = 0;
538 int err = 0;
539
540 if (level != SOL_CAN_RAW)
541 return -EINVAL;
542
543 switch (optname) {
544 case CAN_RAW_FILTER:
545 if (optlen % sizeof(struct can_filter) != 0)
546 return -EINVAL;
547
548 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
549 return -EINVAL;
550
551 count = optlen / sizeof(struct can_filter);
552
553 if (count > 1) {
554 /* filter does not fit into dfilter => alloc space */
555 filter = memdup_sockptr(optval, optlen);
556 if (IS_ERR(filter))
557 return PTR_ERR(filter);
558 } else if (count == 1) {
559 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter)))
560 return -EFAULT;
561 }
562
563 rtnl_lock();
564 lock_sock(sk);
565
566 dev = ro->dev;
567 if (ro->bound && dev) {
568 if (dev->reg_state != NETREG_REGISTERED) {
569 if (count > 1)
570 kfree(filter);
571 err = -ENODEV;
572 goto out_fil;
573 }
574 }
575
576 if (ro->bound) {
577 /* (try to) register the new filters */
578 if (count == 1)
579 err = raw_enable_filters(sock_net(sk), dev, sk,
580 &sfilter, 1);
581 else
582 err = raw_enable_filters(sock_net(sk), dev, sk,
583 filter, count);
584 if (err) {
585 if (count > 1)
586 kfree(filter);
587 goto out_fil;
588 }
589
590 /* remove old filter registrations */
591 raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
592 ro->count);
593 }
594
595 /* remove old filter space */
596 if (ro->count > 1)
597 kfree(ro->filter);
598
599 /* link new filters to the socket */
600 if (count == 1) {
601 /* copy filter data for single filter */
602 ro->dfilter = sfilter;
603 filter = &ro->dfilter;
604 }
605 ro->filter = filter;
606 ro->count = count;
607
608 out_fil:
609 release_sock(sk);
610 rtnl_unlock();
611
612 break;
613
614 case CAN_RAW_ERR_FILTER:
615 if (optlen != sizeof(err_mask))
616 return -EINVAL;
617
618 if (copy_from_sockptr(&err_mask, optval, optlen))
619 return -EFAULT;
620
621 err_mask &= CAN_ERR_MASK;
622
623 rtnl_lock();
624 lock_sock(sk);
625
626 dev = ro->dev;
627 if (ro->bound && dev) {
628 if (dev->reg_state != NETREG_REGISTERED) {
629 err = -ENODEV;
630 goto out_err;
631 }
632 }
633
634 /* remove current error mask */
635 if (ro->bound) {
636 /* (try to) register the new err_mask */
637 err = raw_enable_errfilter(sock_net(sk), dev, sk,
638 err_mask);
639
640 if (err)
641 goto out_err;
642
643 /* remove old err_mask registration */
644 raw_disable_errfilter(sock_net(sk), dev, sk,
645 ro->err_mask);
646 }
647
648 /* link new err_mask to the socket */
649 ro->err_mask = err_mask;
650
651 out_err:
652 release_sock(sk);
653 rtnl_unlock();
654
655 break;
656
657 case CAN_RAW_LOOPBACK:
658 if (optlen != sizeof(ro->loopback))
659 return -EINVAL;
660
661 if (copy_from_sockptr(&ro->loopback, optval, optlen))
662 return -EFAULT;
663
664 break;
665
666 case CAN_RAW_RECV_OWN_MSGS:
667 if (optlen != sizeof(ro->recv_own_msgs))
668 return -EINVAL;
669
670 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen))
671 return -EFAULT;
672
673 break;
674
675 case CAN_RAW_FD_FRAMES:
676 if (optlen != sizeof(fd_frames))
677 return -EINVAL;
678
679 if (copy_from_sockptr(&fd_frames, optval, optlen))
680 return -EFAULT;
681
682 /* Enabling CAN XL includes CAN FD */
683 if (ro->xl_frames && !fd_frames)
684 return -EINVAL;
685
686 ro->fd_frames = fd_frames;
687 break;
688
689 case CAN_RAW_XL_FRAMES:
690 if (optlen != sizeof(ro->xl_frames))
691 return -EINVAL;
692
693 if (copy_from_sockptr(&ro->xl_frames, optval, optlen))
694 return -EFAULT;
695
696 /* Enabling CAN XL includes CAN FD */
697 if (ro->xl_frames)
698 ro->fd_frames = ro->xl_frames;
699 break;
700
701 case CAN_RAW_JOIN_FILTERS:
702 if (optlen != sizeof(ro->join_filters))
703 return -EINVAL;
704
705 if (copy_from_sockptr(&ro->join_filters, optval, optlen))
706 return -EFAULT;
707
708 break;
709
710 default:
711 return -ENOPROTOOPT;
712 }
713 return err;
714}
715
716static int raw_getsockopt(struct socket *sock, int level, int optname,
717 char __user *optval, int __user *optlen)
718{
719 struct sock *sk = sock->sk;
720 struct raw_sock *ro = raw_sk(sk);
721 int len;
722 void *val;
723 int err = 0;
724
725 if (level != SOL_CAN_RAW)
726 return -EINVAL;
727 if (get_user(len, optlen))
728 return -EFAULT;
729 if (len < 0)
730 return -EINVAL;
731
732 switch (optname) {
733 case CAN_RAW_FILTER:
734 lock_sock(sk);
735 if (ro->count > 0) {
736 int fsize = ro->count * sizeof(struct can_filter);
737
738 /* user space buffer to small for filter list? */
739 if (len < fsize) {
740 /* return -ERANGE and needed space in optlen */
741 err = -ERANGE;
742 if (put_user(fsize, optlen))
743 err = -EFAULT;
744 } else {
745 if (len > fsize)
746 len = fsize;
747 if (copy_to_user(optval, ro->filter, len))
748 err = -EFAULT;
749 }
750 } else {
751 len = 0;
752 }
753 release_sock(sk);
754
755 if (!err)
756 err = put_user(len, optlen);
757 return err;
758
759 case CAN_RAW_ERR_FILTER:
760 if (len > sizeof(can_err_mask_t))
761 len = sizeof(can_err_mask_t);
762 val = &ro->err_mask;
763 break;
764
765 case CAN_RAW_LOOPBACK:
766 if (len > sizeof(int))
767 len = sizeof(int);
768 val = &ro->loopback;
769 break;
770
771 case CAN_RAW_RECV_OWN_MSGS:
772 if (len > sizeof(int))
773 len = sizeof(int);
774 val = &ro->recv_own_msgs;
775 break;
776
777 case CAN_RAW_FD_FRAMES:
778 if (len > sizeof(int))
779 len = sizeof(int);
780 val = &ro->fd_frames;
781 break;
782
783 case CAN_RAW_XL_FRAMES:
784 if (len > sizeof(int))
785 len = sizeof(int);
786 val = &ro->xl_frames;
787 break;
788
789 case CAN_RAW_JOIN_FILTERS:
790 if (len > sizeof(int))
791 len = sizeof(int);
792 val = &ro->join_filters;
793 break;
794
795 default:
796 return -ENOPROTOOPT;
797 }
798
799 if (put_user(len, optlen))
800 return -EFAULT;
801 if (copy_to_user(optval, val, len))
802 return -EFAULT;
803 return 0;
804}
805
806static bool raw_bad_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu)
807{
808 /* Classical CAN -> no checks for flags and device capabilities */
809 if (can_is_can_skb(skb))
810 return false;
811
812 /* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */
813 if (ro->fd_frames && can_is_canfd_skb(skb) &&
814 (mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu)))
815 return false;
816
817 /* CAN XL -> needs to be enabled and a CAN XL device */
818 if (ro->xl_frames && can_is_canxl_skb(skb) &&
819 can_is_canxl_dev_mtu(mtu))
820 return false;
821
822 return true;
823}
824
825static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
826{
827 struct sock *sk = sock->sk;
828 struct raw_sock *ro = raw_sk(sk);
829 struct sockcm_cookie sockc;
830 struct sk_buff *skb;
831 struct net_device *dev;
832 int ifindex;
833 int err = -EINVAL;
834
835 /* check for valid CAN frame sizes */
836 if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU)
837 return -EINVAL;
838
839 if (msg->msg_name) {
840 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
841
842 if (msg->msg_namelen < RAW_MIN_NAMELEN)
843 return -EINVAL;
844
845 if (addr->can_family != AF_CAN)
846 return -EINVAL;
847
848 ifindex = addr->can_ifindex;
849 } else {
850 ifindex = ro->ifindex;
851 }
852
853 dev = dev_get_by_index(sock_net(sk), ifindex);
854 if (!dev)
855 return -ENXIO;
856
857 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
858 msg->msg_flags & MSG_DONTWAIT, &err);
859 if (!skb)
860 goto put_dev;
861
862 can_skb_reserve(skb);
863 can_skb_prv(skb)->ifindex = dev->ifindex;
864 can_skb_prv(skb)->skbcnt = 0;
865
866 /* fill the skb before testing for valid CAN frames */
867 err = memcpy_from_msg(skb_put(skb, size), msg, size);
868 if (err < 0)
869 goto free_skb;
870
871 err = -EINVAL;
872 if (raw_bad_txframe(ro, skb, dev->mtu))
873 goto free_skb;
874
875 sockcm_init(&sockc, sk);
876 if (msg->msg_controllen) {
877 err = sock_cmsg_send(sk, msg, &sockc);
878 if (unlikely(err))
879 goto free_skb;
880 }
881
882 skb->dev = dev;
883 skb->priority = READ_ONCE(sk->sk_priority);
884 skb->mark = READ_ONCE(sk->sk_mark);
885 skb->tstamp = sockc.transmit_time;
886
887 skb_setup_tx_timestamp(skb, sockc.tsflags);
888
889 err = can_send(skb, ro->loopback);
890
891 dev_put(dev);
892
893 if (err)
894 goto send_failed;
895
896 return size;
897
898free_skb:
899 kfree_skb(skb);
900put_dev:
901 dev_put(dev);
902send_failed:
903 return err;
904}
905
906static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
907 int flags)
908{
909 struct sock *sk = sock->sk;
910 struct sk_buff *skb;
911 int err = 0;
912
913 if (flags & MSG_ERRQUEUE)
914 return sock_recv_errqueue(sk, msg, size,
915 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
916
917 skb = skb_recv_datagram(sk, flags, &err);
918 if (!skb)
919 return err;
920
921 if (size < skb->len)
922 msg->msg_flags |= MSG_TRUNC;
923 else
924 size = skb->len;
925
926 err = memcpy_to_msg(msg, skb->data, size);
927 if (err < 0) {
928 skb_free_datagram(sk, skb);
929 return err;
930 }
931
932 sock_recv_cmsgs(msg, sk, skb);
933
934 if (msg->msg_name) {
935 __sockaddr_check_size(RAW_MIN_NAMELEN);
936 msg->msg_namelen = RAW_MIN_NAMELEN;
937 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
938 }
939
940 /* assign the flags that have been recorded in raw_rcv() */
941 msg->msg_flags |= *(raw_flags(skb));
942
943 skb_free_datagram(sk, skb);
944
945 return size;
946}
947
948static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
949 unsigned long arg)
950{
951 /* no ioctls for socket layer -> hand it down to NIC layer */
952 return -ENOIOCTLCMD;
953}
954
955static const struct proto_ops raw_ops = {
956 .family = PF_CAN,
957 .release = raw_release,
958 .bind = raw_bind,
959 .connect = sock_no_connect,
960 .socketpair = sock_no_socketpair,
961 .accept = sock_no_accept,
962 .getname = raw_getname,
963 .poll = datagram_poll,
964 .ioctl = raw_sock_no_ioctlcmd,
965 .gettstamp = sock_gettstamp,
966 .listen = sock_no_listen,
967 .shutdown = sock_no_shutdown,
968 .setsockopt = raw_setsockopt,
969 .getsockopt = raw_getsockopt,
970 .sendmsg = raw_sendmsg,
971 .recvmsg = raw_recvmsg,
972 .mmap = sock_no_mmap,
973};
974
975static struct proto raw_proto __read_mostly = {
976 .name = "CAN_RAW",
977 .owner = THIS_MODULE,
978 .obj_size = sizeof(struct raw_sock),
979 .init = raw_init,
980};
981
982static const struct can_proto raw_can_proto = {
983 .type = SOCK_RAW,
984 .protocol = CAN_RAW,
985 .ops = &raw_ops,
986 .prot = &raw_proto,
987};
988
989static struct notifier_block canraw_notifier = {
990 .notifier_call = raw_notifier
991};
992
993static __init int raw_module_init(void)
994{
995 int err;
996
997 pr_info("can: raw protocol\n");
998
999 err = register_netdevice_notifier(&canraw_notifier);
1000 if (err)
1001 return err;
1002
1003 err = can_proto_register(&raw_can_proto);
1004 if (err < 0) {
1005 pr_err("can: registration of raw protocol failed\n");
1006 goto register_proto_failed;
1007 }
1008
1009 return 0;
1010
1011register_proto_failed:
1012 unregister_netdevice_notifier(&canraw_notifier);
1013 return err;
1014}
1015
1016static __exit void raw_module_exit(void)
1017{
1018 can_proto_unregister(&raw_can_proto);
1019 unregister_netdevice_notifier(&canraw_notifier);
1020}
1021
1022module_init(raw_module_init);
1023module_exit(raw_module_exit);