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