aboutsummaryrefslogtreecommitdiffstats
path: root/net/can/raw.c
blob: 07d72d852324f23a8fffdc71798e89602b861977 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
/*
 * raw.c - Raw sockets for protocol family CAN
 *
 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Volkswagen nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Alternatively, provided that this notice is retained in full, this
 * software may be distributed under the terms of the GNU General
 * Public License ("GPL") version 2, in which case the provisions of the
 * GPL apply INSTEAD OF those given above.
 *
 * The provided data structures and external interfaces from this code
 * are not restricted to be used by modules with a GPL compatible license.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/uio.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/socket.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/can.h>
#include <linux/can/core.h>
#include <linux/can/skb.h>
#include <linux/can/raw.h>
#include <net/sock.h>
#include <net/net_namespace.h>

#define CAN_RAW_VERSION CAN_VERSION
static __initconst const char banner[] =
	KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";

MODULE_DESCRIPTION("PF_CAN raw protocol");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
MODULE_ALIAS("can-proto-1");

#define MASK_ALL 0

/*
 * A raw socket has a list of can_filters attached to it, each receiving
 * the CAN frames matching that filter.  If the filter list is empty,
 * no CAN frames will be received by the socket.  The default after
 * opening the socket, is to have one filter which receives all frames.
 * The filter list is allocated dynamically with the exception of the
 * list containing only one item.  This common case is optimized by
 * storing the single filter in dfilter, to avoid using dynamic memory.
 */

struct raw_sock {
	struct sock sk;
	int bound;
	int ifindex;
	struct notifier_block notifier;
	int loopback;
	int recv_own_msgs;
	int fd_frames;
	int count;                 /* number of active filters */
	struct can_filter dfilter; /* default/single filter */
	struct can_filter *filter; /* pointer to filter(s) */
	can_err_mask_t err_mask;
};

/*
 * Return pointer to store the extra msg flags for raw_recvmsg().
 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
 * in skb->cb.
 */
static inline unsigned int *raw_flags(struct sk_buff *skb)
{
	BUILD_BUG_ON(sizeof(skb->cb) <= (sizeof(struct sockaddr_can) +
					 sizeof(unsigned int)));

	/* return pointer after struct sockaddr_can */
	return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
}

static inline struct raw_sock *raw_sk(const struct sock *sk)
{
	return (struct raw_sock *)sk;
}

static void raw_rcv(struct sk_buff *oskb, void *data)
{
	struct sock *sk = (struct sock *)data;
	struct raw_sock *ro = raw_sk(sk);
	struct sockaddr_can *addr;
	struct sk_buff *skb;
	unsigned int *pflags;

	/* check the received tx sock reference */
	if (!ro->recv_own_msgs && oskb->sk == sk)
		return;

	/* do not pass frames with DLC > 8 to a legacy socket */
	if (!ro->fd_frames) {
		struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;

		if (unlikely(cfd->len > CAN_MAX_DLEN))
			return;
	}

	/* clone the given skb to be able to enqueue it into the rcv queue */
	skb = skb_clone(oskb, GFP_ATOMIC);
	if (!skb)
		return;

	/*
	 *  Put the datagram to the queue so that raw_recvmsg() can
	 *  get it from there.  We need to pass the interface index to
	 *  raw_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
	 *  containing the interface index.
	 */

	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
	addr = (struct sockaddr_can *)skb->cb;
	memset(addr, 0, sizeof(*addr));
	addr->can_family  = AF_CAN;
	addr->can_ifindex = skb->dev->ifindex;

	/* add CAN specific message flags for raw_recvmsg() */
	pflags = raw_flags(skb);
	*pflags = 0;
	if (oskb->sk)
		*pflags |= MSG_DONTROUTE;
	if (oskb->sk == sk)
		*pflags |= MSG_CONFIRM;

	if (sock_queue_rcv_skb(sk, skb) < 0)
		kfree_skb(skb);
}

static int raw_enable_filters(struct net_device *dev, struct sock *sk,
			      struct can_filter *filter, int count)
{
	int err = 0;
	int i;

	for (i = 0; i < count; i++) {
		err = can_rx_register(dev, filter[i].can_id,
				      filter[i].can_mask,
				      raw_rcv, sk, "raw");
		if (err) {
			/* clean up successfully registered filters */
			while (--i >= 0)
				can_rx_unregister(dev, filter[i].can_id,
						  filter[i].can_mask,
						  raw_rcv, sk);
			break;
		}
	}

	return err;
}

static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,
				can_err_mask_t err_mask)
{
	int err = 0;

	if (err_mask)
		err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,
				      raw_rcv, sk, "raw");

	return err;
}

static void raw_disable_filters(struct net_device *dev, struct sock *sk,
			      struct can_filter *filter, int count)
{
	int i;

	for (i = 0; i < count; i++)
		can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,
				  raw_rcv, sk);
}

static inline void raw_disable_errfilter(struct net_device *dev,
					 struct sock *sk,
					 can_err_mask_t err_mask)

{
	if (err_mask)
		can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,
				  raw_rcv, sk);
}

static inline void raw_disable_allfilters(struct net_device *dev,
					  struct sock *sk)
{
	struct raw_sock *ro = raw_sk(sk);

	raw_disable_filters(dev, sk, ro->filter, ro->count);
	raw_disable_errfilter(dev, sk, ro->err_mask);
}

static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
{
	struct raw_sock *ro = raw_sk(sk);
	int err;

	err = raw_enable_filters(dev, sk, ro->filter, ro->count);
	if (!err) {
		err = raw_enable_errfilter(dev, sk, ro->err_mask);
		if (err)
			raw_disable_filters(dev, sk, ro->filter, ro->count);
	}

	return err;
}

static int raw_notifier(struct notifier_block *nb,
			unsigned long msg, void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
	struct sock *sk = &ro->sk;

	if (!net_eq(dev_net(dev), &init_net))
		return NOTIFY_DONE;

	if (dev->type != ARPHRD_CAN)
		return NOTIFY_DONE;

	if (ro->ifindex != dev->ifindex)
		return NOTIFY_DONE;

	switch (msg) {

	case NETDEV_UNREGISTER:
		lock_sock(sk);
		/* remove current filters & unregister */
		if (ro->bound)
			raw_disable_allfilters(dev, sk);

		if (ro->count > 1)
			kfree(ro->filter);

		ro->ifindex = 0;
		ro->bound   = 0;
		ro->count   = 0;
		release_sock(sk);

		sk->sk_err = ENODEV;
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_error_report(sk);
		break;

	case NETDEV_DOWN:
		sk->sk_err = ENETDOWN;
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_error_report(sk);
		break;
	}

	return NOTIFY_DONE;
}

static int raw_init(struct sock *sk)
{
	struct raw_sock *ro = raw_sk(sk);

	ro->bound            = 0;
	ro->ifindex          = 0;

	/* set default filter to single entry dfilter */
	ro->dfilter.can_id   = 0;
	ro->dfilter.can_mask = MASK_ALL;
	ro->filter           = &ro->dfilter;
	ro->count            = 1;

	/* set default loopback behaviour */
	ro->loopback         = 1;
	ro->recv_own_msgs    = 0;
	ro->fd_frames        = 0;

	/* set notifier */
	ro->notifier.notifier_call = raw_notifier;

	register_netdevice_notifier(&ro->notifier);

	return 0;
}

static int raw_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro;

	if (!sk)
		return 0;

	ro = raw_sk(sk);

	unregister_netdevice_notifier(&ro->notifier);

	lock_sock(sk);

	/* remove current filters & unregister */
	if (ro->bound) {
		if (ro->ifindex) {
			struct net_device *dev;

			dev = dev_get_by_index(&init_net, ro->ifindex);
			if (dev) {
				raw_disable_allfilters(dev, sk);
				dev_put(dev);
			}
		} else
			raw_disable_allfilters(NULL, sk);
	}

	if (ro->count > 1)
		kfree(ro->filter);

	ro->ifindex = 0;
	ro->bound   = 0;
	ro->count   = 0;

	sock_orphan(sk);
	sock->sk = NULL;

	release_sock(sk);
	sock_put(sk);

	return 0;
}

static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
{
	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	int ifindex;
	int err = 0;
	int notify_enetdown = 0;

	if (len < sizeof(*addr))
		return -EINVAL;

	lock_sock(sk);

	if (ro->bound && addr->can_ifindex == ro->ifindex)
		goto out;

	if (addr->can_ifindex) {
		struct net_device *dev;

		dev = dev_get_by_index(&init_net, addr->can_ifindex);
		if (!dev) {
			err = -ENODEV;
			goto out;
		}
		if (dev->type != ARPHRD_CAN) {
			dev_put(dev);
			err = -ENODEV;
			goto out;
		}
		if (!(dev->flags & IFF_UP))
			notify_enetdown = 1;

		ifindex = dev->ifindex;

		/* filters set by default/setsockopt */
		err = raw_enable_allfilters(dev, sk);
		dev_put(dev);
	} else {
		ifindex = 0;

		/* filters set by default/setsockopt */
		err = raw_enable_allfilters(NULL, sk);
	}

	if (!err) {
		if (ro->bound) {
			/* unregister old filters */
			if (ro->ifindex) {
				struct net_device *dev;

				dev = dev_get_by_index(&init_net, ro->ifindex);
				if (dev) {
					raw_disable_allfilters(dev, sk);
					dev_put(dev);
				}
			} else
				raw_disable_allfilters(NULL, sk);
		}
		ro->ifindex = ifindex;
		ro->bound = 1;
	}

 out:
	release_sock(sk);

	if (notify_enetdown) {
		sk->sk_err = ENETDOWN;
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_error_report(sk);
	}

	return err;
}

static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
		       int *len, int peer)
{
	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);

	if (peer)
		return -EOPNOTSUPP;

	memset(addr, 0, sizeof(*addr));
	addr->can_family  = AF_CAN;
	addr->can_ifindex = ro->ifindex;

	*len = sizeof(*addr);

	return 0;
}

static int raw_setsockopt(struct socket *sock, int level, int optname,
			  char __user *optval, unsigned int optlen)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
	struct can_filter sfilter;         /* single filter */
	struct net_device *dev = NULL;
	can_err_mask_t err_mask = 0;
	int count = 0;
	int err = 0;

	if (level != SOL_CAN_RAW)
		return -EINVAL;

	switch (optname) {

	case CAN_RAW_FILTER:
		if (optlen % sizeof(struct can_filter) != 0)
			return -EINVAL;

		count = optlen / sizeof(struct can_filter);

		if (count > 1) {
			/* filter does not fit into dfilter => alloc space */
			filter = memdup_user(optval, optlen);
			if (IS_ERR(filter))
				return PTR_ERR(filter);
		} else if (count == 1) {
			if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
				return -EFAULT;
		}

		lock_sock(sk);

		if (ro->bound && ro->ifindex)
			dev = dev_get_by_index(&init_net, ro->ifindex);

		if (ro->bound) {
			/* (try to) register the new filters */
			if (count == 1)
				err = raw_enable_filters(dev, sk, &sfilter, 1);
			else
				err = raw_enable_filters(dev, sk, filter,
							 count);
			if (err) {
				if (count > 1)
					kfree(filter);
				goto out_fil;
			}

			/* remove old filter registrations */
			raw_disable_filters(dev, sk, ro->filter, ro->count);
		}

		/* remove old filter space */
		if (ro->count > 1)
			kfree(ro->filter);

		/* link new filters to the socket */
		if (count == 1) {
			/* copy filter data for single filter */
			ro->dfilter = sfilter;
			filter = &ro->dfilter;
		}
		ro->filter = filter;
		ro->count  = count;

 out_fil:
		if (dev)
			dev_put(dev);

		release_sock(sk);

		break;

	case CAN_RAW_ERR_FILTER:
		if (optlen != sizeof(err_mask))
			return -EINVAL;

		if (copy_from_user(&err_mask, optval, optlen))
			return -EFAULT;

		err_mask &= CAN_ERR_MASK;

		lock_sock(sk);

		if (ro->bound && ro->ifindex)
			dev = dev_get_by_index(&init_net, ro->ifindex);

		/* remove current error mask */
		if (ro->bound) {
			/* (try to) register the new err_mask */
			err = raw_enable_errfilter(dev, sk, err_mask);

			if (err)
				goto out_err;

			/* remove old err_mask registration */
			raw_disable_errfilter(dev, sk, ro->err_mask);
		}

		/* link new err_mask to the socket */
		ro->err_mask = err_mask;

 out_err:
		if (dev)
			dev_put(dev);

		release_sock(sk);

		break;

	case CAN_RAW_LOOPBACK:
		if (optlen != sizeof(ro->loopback))
			return -EINVAL;

		if (copy_from_user(&ro->loopback, optval, optlen))
			return -EFAULT;

		break;

	case CAN_RAW_RECV_OWN_MSGS:
		if (optlen != sizeof(ro->recv_own_msgs))
			return -EINVAL;

		if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
			return -EFAULT;

		break;

	case CAN_RAW_FD_FRAMES:
		if (optlen != sizeof(ro->fd_frames))
			return -EINVAL;

		if (copy_from_user(&ro->fd_frames, optval, optlen))
			return -EFAULT;

		break;

	default:
		return -ENOPROTOOPT;
	}
	return err;
}

static int raw_getsockopt(struct socket *sock, int level, int optname,
			  char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	int len;
	void *val;
	int err = 0;

	if (level != SOL_CAN_RAW)
		return -EINVAL;
	if (get_user(len, optlen))
		return -EFAULT;
	if (len < 0)
		return -EINVAL;

	switch (optname) {

	case CAN_RAW_FILTER:
		lock_sock(sk);
		if (ro->count > 0) {
			int fsize = ro->count * sizeof(struct can_filter);
			if (len > fsize)
				len = fsize;
			if (copy_to_user(optval, ro->filter, len))
				err = -EFAULT;
		} else
			len = 0;
		release_sock(sk);

		if (!err)
			err = put_user(len, optlen);
		return err;

	case CAN_RAW_ERR_FILTER:
		if (len > sizeof(can_err_mask_t))
			len = sizeof(can_err_mask_t);
		val = &ro->err_mask;
		break;

	case CAN_RAW_LOOPBACK:
		if (len > sizeof(int))
			len = sizeof(int);
		val = &ro->loopback;
		break;

	case CAN_RAW_RECV_OWN_MSGS:
		if (len > sizeof(int))
			len = sizeof(int);
		val = &ro->recv_own_msgs;
		break;

	case CAN_RAW_FD_FRAMES:
		if (len > sizeof(int))
			len = sizeof(int);
		val = &ro->fd_frames;
		break;

	default:
		return -ENOPROTOOPT;
	}

	if (put_user(len, optlen))
		return -EFAULT;
	if (copy_to_user(optval, val, len))
		return -EFAULT;
	return 0;
}

static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
		       struct msghdr *msg, size_t size)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	struct sk_buff *skb;
	struct net_device *dev;
	int ifindex;
	int err;

	if (msg->msg_name) {
		DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);

		if (msg->msg_namelen < sizeof(*addr))
			return -EINVAL;

		if (addr->can_family != AF_CAN)
			return -EINVAL;

		ifindex = addr->can_ifindex;
	} else
		ifindex = ro->ifindex;

	if (ro->fd_frames) {
		if (unlikely(size != CANFD_MTU && size != CAN_MTU))
			return -EINVAL;
	} else {
		if (unlikely(size != CAN_MTU))
			return -EINVAL;
	}

	dev = dev_get_by_index(&init_net, ifindex);
	if (!dev)
		return -ENXIO;

	skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
				  msg->msg_flags & MSG_DONTWAIT, &err);
	if (!skb)
		goto put_dev;

	can_skb_reserve(skb);
	can_skb_prv(skb)->ifindex = dev->ifindex;

	err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
	if (err < 0)
		goto free_skb;

	sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);

	skb->dev = dev;
	skb->sk  = sk;

	err = can_send(skb, ro->loopback);

	dev_put(dev);

	if (err)
		goto send_failed;

	return size;

free_skb:
	kfree_skb(skb);
put_dev:
	dev_put(dev);
send_failed:
	return err;
}

static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
		       struct msghdr *msg, size_t size, int flags)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	struct sk_buff *skb;
	int rxmtu;
	int err = 0;
	int noblock;

	noblock =  flags & MSG_DONTWAIT;
	flags   &= ~MSG_DONTWAIT;

	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb)
		return err;

	/*
	 * when serving a legacy socket the DLC <= 8 is already checked inside
	 * raw_rcv(). Now check if we need to pass a canfd_frame to a legacy
	 * socket and cut the possible CANFD_MTU/CAN_MTU length to CAN_MTU
	 */
	if (!ro->fd_frames)
		rxmtu = CAN_MTU;
	else
		rxmtu = skb->len;

	if (size < rxmtu)
		msg->msg_flags |= MSG_TRUNC;
	else
		size = rxmtu;

	err = memcpy_toiovec(msg->msg_iov, skb->data, size);
	if (err < 0) {
		skb_free_datagram(sk, skb);
		return err;
	}

	sock_recv_ts_and_drops(msg, sk, skb);

	if (msg->msg_name) {
		__sockaddr_check_size(sizeof(struct sockaddr_can));
		msg->msg_namelen = sizeof(struct sockaddr_can);
		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
	}

	/* assign the flags that have been recorded in raw_rcv() */
	msg->msg_flags |= *(raw_flags(skb));

	skb_free_datagram(sk, skb);

	return size;
}

static const struct proto_ops raw_ops = {
	.family        = PF_CAN,
	.release       = raw_release,
	.bind          = raw_bind,
	.connect       = sock_no_connect,
	.socketpair    = sock_no_socketpair,
	.accept        = sock_no_accept,
	.getname       = raw_getname,
	.poll          = datagram_poll,
	.ioctl         = can_ioctl,	/* use can_ioctl() from af_can.c */
	.listen        = sock_no_listen,
	.shutdown      = sock_no_shutdown,
	.setsockopt    = raw_setsockopt,
	.getsockopt    = raw_getsockopt,
	.sendmsg       = raw_sendmsg,
	.recvmsg       = raw_recvmsg,
	.mmap          = sock_no_mmap,
	.sendpage      = sock_no_sendpage,
};

static struct proto raw_proto __read_mostly = {
	.name       = "CAN_RAW",
	.owner      = THIS_MODULE,
	.obj_size   = sizeof(struct raw_sock),
	.init       = raw_init,
};

static const struct can_proto raw_can_proto = {
	.type       = SOCK_RAW,
	.protocol   = CAN_RAW,
	.ops        = &raw_ops,
	.prot       = &raw_proto,
};

static __init int raw_module_init(void)
{
	int err;

	printk(banner);

	err = can_proto_register(&raw_can_proto);
	if (err < 0)
		printk(KERN_ERR "can: registration of raw protocol failed\n");

	return err;
}

static __exit void raw_module_exit(void)
{
	can_proto_unregister(&raw_can_proto);
}

module_init(raw_module_init);
module_exit(raw_module_exit);