1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /* raw.c - Raw sockets for protocol family CAN
3 *
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42 #include <linux/module.h>
43 #include <linux/init.h>
44 #include <linux/uio.h>
45 #include <linux/net.h>
46 #include <linux/slab.h>
47 #include <linux/netdevice.h>
48 #include <linux/socket.h>
49 #include <linux/if_arp.h>
50 #include <linux/skbuff.h>
51 #include <linux/can.h>
52 #include <linux/can/core.h>
53 #include <linux/can/skb.h>
54 #include <linux/can/raw.h>
55 #include <net/sock.h>
56 #include <net/net_namespace.h>
57
58 MODULE_DESCRIPTION("PF_CAN raw protocol");
59 MODULE_LICENSE("Dual BSD/GPL");
60 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
61 MODULE_ALIAS("can-proto-1");
62
63 #define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
64
65 #define MASK_ALL 0
66
67 /* A raw socket has a list of can_filters attached to it, each receiving
68 * the CAN frames matching that filter. If the filter list is empty,
69 * no CAN frames will be received by the socket. The default after
70 * opening the socket, is to have one filter which receives all frames.
71 * The filter list is allocated dynamically with the exception of the
72 * list containing only one item. This common case is optimized by
73 * storing the single filter in dfilter, to avoid using dynamic memory.
74 */
75
76 struct uniqframe {
77 int skbcnt;
78 const struct sk_buff *skb;
79 unsigned int join_rx_count;
80 };
81
82 struct raw_sock {
83 struct sock sk;
84 int bound;
85 int ifindex;
86 struct list_head notifier;
87 int loopback;
88 int recv_own_msgs;
89 int fd_frames;
90 int join_filters;
91 int count; /* number of active filters */
92 struct can_filter dfilter; /* default/single filter */
93 struct can_filter *filter; /* pointer to filter(s) */
94 can_err_mask_t err_mask;
95 struct uniqframe __percpu *uniq;
96 };
97
98 static LIST_HEAD(raw_notifier_list);
99 static DEFINE_SPINLOCK(raw_notifier_lock);
100 static struct raw_sock *raw_busy_notifier;
101
102 /* Return pointer to store the extra msg flags for raw_recvmsg().
103 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
104 * in skb->cb.
105 */
raw_flags(struct sk_buff * skb)106 static inline unsigned int *raw_flags(struct sk_buff *skb)
107 {
108 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
109 sizeof(unsigned int));
110
111 /* return pointer after struct sockaddr_can */
112 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
113 }
114
raw_sk(const struct sock * sk)115 static inline struct raw_sock *raw_sk(const struct sock *sk)
116 {
117 return (struct raw_sock *)sk;
118 }
119
raw_rcv(struct sk_buff * oskb,void * data)120 static void raw_rcv(struct sk_buff *oskb, void *data)
121 {
122 struct sock *sk = (struct sock *)data;
123 struct raw_sock *ro = raw_sk(sk);
124 struct sockaddr_can *addr;
125 struct sk_buff *skb;
126 unsigned int *pflags;
127
128 /* check the received tx sock reference */
129 if (!ro->recv_own_msgs && oskb->sk == sk)
130 return;
131
132 /* do not pass non-CAN2.0 frames to a legacy socket */
133 if (!ro->fd_frames && oskb->len != CAN_MTU)
134 return;
135
136 /* eliminate multiple filter matches for the same skb */
137 if (this_cpu_ptr(ro->uniq)->skb == oskb &&
138 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
139 if (ro->join_filters) {
140 this_cpu_inc(ro->uniq->join_rx_count);
141 /* drop frame until all enabled filters matched */
142 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
143 return;
144 } else {
145 return;
146 }
147 } else {
148 this_cpu_ptr(ro->uniq)->skb = oskb;
149 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
150 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
151 /* drop first frame to check all enabled filters? */
152 if (ro->join_filters && ro->count > 1)
153 return;
154 }
155
156 /* clone the given skb to be able to enqueue it into the rcv queue */
157 skb = skb_clone(oskb, GFP_ATOMIC);
158 if (!skb)
159 return;
160
161 /* Put the datagram to the queue so that raw_recvmsg() can get
162 * it from there. We need to pass the interface index to
163 * raw_recvmsg(). We pass a whole struct sockaddr_can in
164 * skb->cb containing the interface index.
165 */
166
167 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
168 addr = (struct sockaddr_can *)skb->cb;
169 memset(addr, 0, sizeof(*addr));
170 addr->can_family = AF_CAN;
171 addr->can_ifindex = skb->dev->ifindex;
172
173 /* add CAN specific message flags for raw_recvmsg() */
174 pflags = raw_flags(skb);
175 *pflags = 0;
176 if (oskb->sk)
177 *pflags |= MSG_DONTROUTE;
178 if (oskb->sk == sk)
179 *pflags |= MSG_CONFIRM;
180
181 if (sock_queue_rcv_skb(sk, skb) < 0)
182 kfree_skb(skb);
183 }
184
raw_enable_filters(struct net * net,struct net_device * dev,struct sock * sk,struct can_filter * filter,int count)185 static int raw_enable_filters(struct net *net, struct net_device *dev,
186 struct sock *sk, struct can_filter *filter,
187 int count)
188 {
189 int err = 0;
190 int i;
191
192 for (i = 0; i < count; i++) {
193 err = can_rx_register(net, dev, filter[i].can_id,
194 filter[i].can_mask,
195 raw_rcv, sk, "raw", sk);
196 if (err) {
197 /* clean up successfully registered filters */
198 while (--i >= 0)
199 can_rx_unregister(net, dev, filter[i].can_id,
200 filter[i].can_mask,
201 raw_rcv, sk);
202 break;
203 }
204 }
205
206 return err;
207 }
208
raw_enable_errfilter(struct net * net,struct net_device * dev,struct sock * sk,can_err_mask_t err_mask)209 static int raw_enable_errfilter(struct net *net, struct net_device *dev,
210 struct sock *sk, can_err_mask_t err_mask)
211 {
212 int err = 0;
213
214 if (err_mask)
215 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
216 raw_rcv, sk, "raw", sk);
217
218 return err;
219 }
220
raw_disable_filters(struct net * net,struct net_device * dev,struct sock * sk,struct can_filter * filter,int count)221 static void raw_disable_filters(struct net *net, struct net_device *dev,
222 struct sock *sk, struct can_filter *filter,
223 int count)
224 {
225 int i;
226
227 for (i = 0; i < count; i++)
228 can_rx_unregister(net, dev, filter[i].can_id,
229 filter[i].can_mask, raw_rcv, sk);
230 }
231
raw_disable_errfilter(struct net * net,struct net_device * dev,struct sock * sk,can_err_mask_t err_mask)232 static inline void raw_disable_errfilter(struct net *net,
233 struct net_device *dev,
234 struct sock *sk,
235 can_err_mask_t err_mask)
236
237 {
238 if (err_mask)
239 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
240 raw_rcv, sk);
241 }
242
raw_disable_allfilters(struct net * net,struct net_device * dev,struct sock * sk)243 static inline void raw_disable_allfilters(struct net *net,
244 struct net_device *dev,
245 struct sock *sk)
246 {
247 struct raw_sock *ro = raw_sk(sk);
248
249 raw_disable_filters(net, dev, sk, ro->filter, ro->count);
250 raw_disable_errfilter(net, dev, sk, ro->err_mask);
251 }
252
raw_enable_allfilters(struct net * net,struct net_device * dev,struct sock * sk)253 static int raw_enable_allfilters(struct net *net, struct net_device *dev,
254 struct sock *sk)
255 {
256 struct raw_sock *ro = raw_sk(sk);
257 int err;
258
259 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
260 if (!err) {
261 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
262 if (err)
263 raw_disable_filters(net, dev, sk, ro->filter,
264 ro->count);
265 }
266
267 return err;
268 }
269
raw_notify(struct raw_sock * ro,unsigned long msg,struct net_device * dev)270 static void raw_notify(struct raw_sock *ro, unsigned long msg,
271 struct net_device *dev)
272 {
273 struct sock *sk = &ro->sk;
274
275 if (!net_eq(dev_net(dev), sock_net(sk)))
276 return;
277
278 if (ro->ifindex != dev->ifindex)
279 return;
280
281 switch (msg) {
282 case NETDEV_UNREGISTER:
283 lock_sock(sk);
284 /* remove current filters & unregister */
285 if (ro->bound)
286 raw_disable_allfilters(dev_net(dev), dev, sk);
287
288 if (ro->count > 1)
289 kfree(ro->filter);
290
291 ro->ifindex = 0;
292 ro->bound = 0;
293 ro->count = 0;
294 release_sock(sk);
295
296 sk->sk_err = ENODEV;
297 if (!sock_flag(sk, SOCK_DEAD))
298 sk_error_report(sk);
299 break;
300
301 case NETDEV_DOWN:
302 sk->sk_err = ENETDOWN;
303 if (!sock_flag(sk, SOCK_DEAD))
304 sk_error_report(sk);
305 break;
306 }
307 }
308
raw_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)309 static int raw_notifier(struct notifier_block *nb, unsigned long msg,
310 void *ptr)
311 {
312 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
313
314 if (dev->type != ARPHRD_CAN)
315 return NOTIFY_DONE;
316 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
317 return NOTIFY_DONE;
318 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
319 return NOTIFY_DONE;
320
321 spin_lock(&raw_notifier_lock);
322 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
323 spin_unlock(&raw_notifier_lock);
324 raw_notify(raw_busy_notifier, msg, dev);
325 spin_lock(&raw_notifier_lock);
326 }
327 raw_busy_notifier = NULL;
328 spin_unlock(&raw_notifier_lock);
329 return NOTIFY_DONE;
330 }
331
raw_init(struct sock * sk)332 static int raw_init(struct sock *sk)
333 {
334 struct raw_sock *ro = raw_sk(sk);
335
336 ro->bound = 0;
337 ro->ifindex = 0;
338
339 /* set default filter to single entry dfilter */
340 ro->dfilter.can_id = 0;
341 ro->dfilter.can_mask = MASK_ALL;
342 ro->filter = &ro->dfilter;
343 ro->count = 1;
344
345 /* set default loopback behaviour */
346 ro->loopback = 1;
347 ro->recv_own_msgs = 0;
348 ro->fd_frames = 0;
349 ro->join_filters = 0;
350
351 /* alloc_percpu provides zero'ed memory */
352 ro->uniq = alloc_percpu(struct uniqframe);
353 if (unlikely(!ro->uniq))
354 return -ENOMEM;
355
356 /* set notifier */
357 spin_lock(&raw_notifier_lock);
358 list_add_tail(&ro->notifier, &raw_notifier_list);
359 spin_unlock(&raw_notifier_lock);
360
361 return 0;
362 }
363
raw_release(struct socket * sock)364 static int raw_release(struct socket *sock)
365 {
366 struct sock *sk = sock->sk;
367 struct raw_sock *ro;
368
369 if (!sk)
370 return 0;
371
372 ro = raw_sk(sk);
373
374 spin_lock(&raw_notifier_lock);
375 while (raw_busy_notifier == ro) {
376 spin_unlock(&raw_notifier_lock);
377 schedule_timeout_uninterruptible(1);
378 spin_lock(&raw_notifier_lock);
379 }
380 list_del(&ro->notifier);
381 spin_unlock(&raw_notifier_lock);
382
383 lock_sock(sk);
384
385 /* remove current filters & unregister */
386 if (ro->bound) {
387 if (ro->ifindex) {
388 struct net_device *dev;
389
390 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
391 if (dev) {
392 raw_disable_allfilters(dev_net(dev), dev, sk);
393 dev_put(dev);
394 }
395 } else {
396 raw_disable_allfilters(sock_net(sk), NULL, sk);
397 }
398 }
399
400 if (ro->count > 1)
401 kfree(ro->filter);
402
403 ro->ifindex = 0;
404 ro->bound = 0;
405 ro->count = 0;
406 free_percpu(ro->uniq);
407
408 sock_orphan(sk);
409 sock->sk = NULL;
410
411 release_sock(sk);
412 sock_put(sk);
413
414 return 0;
415 }
416
raw_bind(struct socket * sock,struct sockaddr * uaddr,int len)417 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
418 {
419 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
420 struct sock *sk = sock->sk;
421 struct raw_sock *ro = raw_sk(sk);
422 int ifindex;
423 int err = 0;
424 int notify_enetdown = 0;
425
426 if (len < RAW_MIN_NAMELEN)
427 return -EINVAL;
428 if (addr->can_family != AF_CAN)
429 return -EINVAL;
430
431 lock_sock(sk);
432
433 if (ro->bound && addr->can_ifindex == ro->ifindex)
434 goto out;
435
436 if (addr->can_ifindex) {
437 struct net_device *dev;
438
439 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
440 if (!dev) {
441 err = -ENODEV;
442 goto out;
443 }
444 if (dev->type != ARPHRD_CAN) {
445 dev_put(dev);
446 err = -ENODEV;
447 goto out;
448 }
449 if (!(dev->flags & IFF_UP))
450 notify_enetdown = 1;
451
452 ifindex = dev->ifindex;
453
454 /* filters set by default/setsockopt */
455 err = raw_enable_allfilters(sock_net(sk), dev, sk);
456 dev_put(dev);
457 } else {
458 ifindex = 0;
459
460 /* filters set by default/setsockopt */
461 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
462 }
463
464 if (!err) {
465 if (ro->bound) {
466 /* unregister old filters */
467 if (ro->ifindex) {
468 struct net_device *dev;
469
470 dev = dev_get_by_index(sock_net(sk),
471 ro->ifindex);
472 if (dev) {
473 raw_disable_allfilters(dev_net(dev),
474 dev, sk);
475 dev_put(dev);
476 }
477 } else {
478 raw_disable_allfilters(sock_net(sk), NULL, sk);
479 }
480 }
481 ro->ifindex = ifindex;
482 ro->bound = 1;
483 }
484
485 out:
486 release_sock(sk);
487
488 if (notify_enetdown) {
489 sk->sk_err = ENETDOWN;
490 if (!sock_flag(sk, SOCK_DEAD))
491 sk_error_report(sk);
492 }
493
494 return err;
495 }
496
raw_getname(struct socket * sock,struct sockaddr * uaddr,int peer)497 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
498 int peer)
499 {
500 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
501 struct sock *sk = sock->sk;
502 struct raw_sock *ro = raw_sk(sk);
503
504 if (peer)
505 return -EOPNOTSUPP;
506
507 memset(addr, 0, RAW_MIN_NAMELEN);
508 addr->can_family = AF_CAN;
509 addr->can_ifindex = ro->ifindex;
510
511 return RAW_MIN_NAMELEN;
512 }
513
raw_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)514 static int raw_setsockopt(struct socket *sock, int level, int optname,
515 sockptr_t optval, unsigned int optlen)
516 {
517 struct sock *sk = sock->sk;
518 struct raw_sock *ro = raw_sk(sk);
519 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
520 struct can_filter sfilter; /* single filter */
521 struct net_device *dev = NULL;
522 can_err_mask_t err_mask = 0;
523 int count = 0;
524 int err = 0;
525
526 if (level != SOL_CAN_RAW)
527 return -EINVAL;
528
529 switch (optname) {
530 case CAN_RAW_FILTER:
531 if (optlen % sizeof(struct can_filter) != 0)
532 return -EINVAL;
533
534 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
535 return -EINVAL;
536
537 count = optlen / sizeof(struct can_filter);
538
539 if (count > 1) {
540 /* filter does not fit into dfilter => alloc space */
541 filter = memdup_sockptr(optval, optlen);
542 if (IS_ERR(filter))
543 return PTR_ERR(filter);
544 } else if (count == 1) {
545 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter)))
546 return -EFAULT;
547 }
548
549 rtnl_lock();
550 lock_sock(sk);
551
552 if (ro->bound && ro->ifindex) {
553 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
554 if (!dev) {
555 if (count > 1)
556 kfree(filter);
557 err = -ENODEV;
558 goto out_fil;
559 }
560 }
561
562 if (ro->bound) {
563 /* (try to) register the new filters */
564 if (count == 1)
565 err = raw_enable_filters(sock_net(sk), dev, sk,
566 &sfilter, 1);
567 else
568 err = raw_enable_filters(sock_net(sk), dev, sk,
569 filter, count);
570 if (err) {
571 if (count > 1)
572 kfree(filter);
573 goto out_fil;
574 }
575
576 /* remove old filter registrations */
577 raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
578 ro->count);
579 }
580
581 /* remove old filter space */
582 if (ro->count > 1)
583 kfree(ro->filter);
584
585 /* link new filters to the socket */
586 if (count == 1) {
587 /* copy filter data for single filter */
588 ro->dfilter = sfilter;
589 filter = &ro->dfilter;
590 }
591 ro->filter = filter;
592 ro->count = count;
593
594 out_fil:
595 dev_put(dev);
596 release_sock(sk);
597 rtnl_unlock();
598
599 break;
600
601 case CAN_RAW_ERR_FILTER:
602 if (optlen != sizeof(err_mask))
603 return -EINVAL;
604
605 if (copy_from_sockptr(&err_mask, optval, optlen))
606 return -EFAULT;
607
608 err_mask &= CAN_ERR_MASK;
609
610 rtnl_lock();
611 lock_sock(sk);
612
613 if (ro->bound && ro->ifindex) {
614 dev = dev_get_by_index(sock_net(sk), ro->ifindex);
615 if (!dev) {
616 err = -ENODEV;
617 goto out_err;
618 }
619 }
620
621 /* remove current error mask */
622 if (ro->bound) {
623 /* (try to) register the new err_mask */
624 err = raw_enable_errfilter(sock_net(sk), dev, sk,
625 err_mask);
626
627 if (err)
628 goto out_err;
629
630 /* remove old err_mask registration */
631 raw_disable_errfilter(sock_net(sk), dev, sk,
632 ro->err_mask);
633 }
634
635 /* link new err_mask to the socket */
636 ro->err_mask = err_mask;
637
638 out_err:
639 dev_put(dev);
640 release_sock(sk);
641 rtnl_unlock();
642
643 break;
644
645 case CAN_RAW_LOOPBACK:
646 if (optlen != sizeof(ro->loopback))
647 return -EINVAL;
648
649 if (copy_from_sockptr(&ro->loopback, optval, optlen))
650 return -EFAULT;
651
652 break;
653
654 case CAN_RAW_RECV_OWN_MSGS:
655 if (optlen != sizeof(ro->recv_own_msgs))
656 return -EINVAL;
657
658 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen))
659 return -EFAULT;
660
661 break;
662
663 case CAN_RAW_FD_FRAMES:
664 if (optlen != sizeof(ro->fd_frames))
665 return -EINVAL;
666
667 if (copy_from_sockptr(&ro->fd_frames, optval, optlen))
668 return -EFAULT;
669
670 break;
671
672 case CAN_RAW_JOIN_FILTERS:
673 if (optlen != sizeof(ro->join_filters))
674 return -EINVAL;
675
676 if (copy_from_sockptr(&ro->join_filters, optval, optlen))
677 return -EFAULT;
678
679 break;
680
681 default:
682 return -ENOPROTOOPT;
683 }
684 return err;
685 }
686
raw_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)687 static int raw_getsockopt(struct socket *sock, int level, int optname,
688 char __user *optval, int __user *optlen)
689 {
690 struct sock *sk = sock->sk;
691 struct raw_sock *ro = raw_sk(sk);
692 int len;
693 void *val;
694 int err = 0;
695
696 if (level != SOL_CAN_RAW)
697 return -EINVAL;
698 if (get_user(len, optlen))
699 return -EFAULT;
700 if (len < 0)
701 return -EINVAL;
702
703 switch (optname) {
704 case CAN_RAW_FILTER:
705 lock_sock(sk);
706 if (ro->count > 0) {
707 int fsize = ro->count * sizeof(struct can_filter);
708
709 /* user space buffer to small for filter list? */
710 if (len < fsize) {
711 /* return -ERANGE and needed space in optlen */
712 err = -ERANGE;
713 if (put_user(fsize, optlen))
714 err = -EFAULT;
715 } else {
716 if (len > fsize)
717 len = fsize;
718 if (copy_to_user(optval, ro->filter, len))
719 err = -EFAULT;
720 }
721 } else {
722 len = 0;
723 }
724 release_sock(sk);
725
726 if (!err)
727 err = put_user(len, optlen);
728 return err;
729
730 case CAN_RAW_ERR_FILTER:
731 if (len > sizeof(can_err_mask_t))
732 len = sizeof(can_err_mask_t);
733 val = &ro->err_mask;
734 break;
735
736 case CAN_RAW_LOOPBACK:
737 if (len > sizeof(int))
738 len = sizeof(int);
739 val = &ro->loopback;
740 break;
741
742 case CAN_RAW_RECV_OWN_MSGS:
743 if (len > sizeof(int))
744 len = sizeof(int);
745 val = &ro->recv_own_msgs;
746 break;
747
748 case CAN_RAW_FD_FRAMES:
749 if (len > sizeof(int))
750 len = sizeof(int);
751 val = &ro->fd_frames;
752 break;
753
754 case CAN_RAW_JOIN_FILTERS:
755 if (len > sizeof(int))
756 len = sizeof(int);
757 val = &ro->join_filters;
758 break;
759
760 default:
761 return -ENOPROTOOPT;
762 }
763
764 if (put_user(len, optlen))
765 return -EFAULT;
766 if (copy_to_user(optval, val, len))
767 return -EFAULT;
768 return 0;
769 }
770
raw_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)771 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
772 {
773 struct sock *sk = sock->sk;
774 struct raw_sock *ro = raw_sk(sk);
775 struct sk_buff *skb;
776 struct net_device *dev;
777 int ifindex;
778 int err;
779
780 if (msg->msg_name) {
781 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
782
783 if (msg->msg_namelen < RAW_MIN_NAMELEN)
784 return -EINVAL;
785
786 if (addr->can_family != AF_CAN)
787 return -EINVAL;
788
789 ifindex = addr->can_ifindex;
790 } else {
791 ifindex = ro->ifindex;
792 }
793
794 dev = dev_get_by_index(sock_net(sk), ifindex);
795 if (!dev)
796 return -ENXIO;
797
798 err = -EINVAL;
799 if (ro->fd_frames && dev->mtu == CANFD_MTU) {
800 if (unlikely(size != CANFD_MTU && size != CAN_MTU))
801 goto put_dev;
802 } else {
803 if (unlikely(size != CAN_MTU))
804 goto put_dev;
805 }
806
807 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
808 msg->msg_flags & MSG_DONTWAIT, &err);
809 if (!skb)
810 goto put_dev;
811
812 can_skb_reserve(skb);
813 can_skb_prv(skb)->ifindex = dev->ifindex;
814 can_skb_prv(skb)->skbcnt = 0;
815
816 err = memcpy_from_msg(skb_put(skb, size), msg, size);
817 if (err < 0)
818 goto free_skb;
819
820 skb_setup_tx_timestamp(skb, sk->sk_tsflags);
821
822 skb->dev = dev;
823 skb->sk = sk;
824 skb->priority = sk->sk_priority;
825
826 err = can_send(skb, ro->loopback);
827
828 dev_put(dev);
829
830 if (err)
831 goto send_failed;
832
833 return size;
834
835 free_skb:
836 kfree_skb(skb);
837 put_dev:
838 dev_put(dev);
839 send_failed:
840 return err;
841 }
842
raw_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)843 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
844 int flags)
845 {
846 struct sock *sk = sock->sk;
847 struct sk_buff *skb;
848 int err = 0;
849 int noblock;
850
851 noblock = flags & MSG_DONTWAIT;
852 flags &= ~MSG_DONTWAIT;
853
854 if (flags & MSG_ERRQUEUE)
855 return sock_recv_errqueue(sk, msg, size,
856 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
857
858 skb = skb_recv_datagram(sk, flags, noblock, &err);
859 if (!skb)
860 return err;
861
862 if (size < skb->len)
863 msg->msg_flags |= MSG_TRUNC;
864 else
865 size = skb->len;
866
867 err = memcpy_to_msg(msg, skb->data, size);
868 if (err < 0) {
869 skb_free_datagram(sk, skb);
870 return err;
871 }
872
873 sock_recv_ts_and_drops(msg, sk, skb);
874
875 if (msg->msg_name) {
876 __sockaddr_check_size(RAW_MIN_NAMELEN);
877 msg->msg_namelen = RAW_MIN_NAMELEN;
878 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
879 }
880
881 /* assign the flags that have been recorded in raw_rcv() */
882 msg->msg_flags |= *(raw_flags(skb));
883
884 skb_free_datagram(sk, skb);
885
886 return size;
887 }
888
raw_sock_no_ioctlcmd(struct socket * sock,unsigned int cmd,unsigned long arg)889 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
890 unsigned long arg)
891 {
892 /* no ioctls for socket layer -> hand it down to NIC layer */
893 return -ENOIOCTLCMD;
894 }
895
896 static const struct proto_ops raw_ops = {
897 .family = PF_CAN,
898 .release = raw_release,
899 .bind = raw_bind,
900 .connect = sock_no_connect,
901 .socketpair = sock_no_socketpair,
902 .accept = sock_no_accept,
903 .getname = raw_getname,
904 .poll = datagram_poll,
905 .ioctl = raw_sock_no_ioctlcmd,
906 .gettstamp = sock_gettstamp,
907 .listen = sock_no_listen,
908 .shutdown = sock_no_shutdown,
909 .setsockopt = raw_setsockopt,
910 .getsockopt = raw_getsockopt,
911 .sendmsg = raw_sendmsg,
912 .recvmsg = raw_recvmsg,
913 .mmap = sock_no_mmap,
914 .sendpage = sock_no_sendpage,
915 };
916
917 static struct proto raw_proto __read_mostly = {
918 .name = "CAN_RAW",
919 .owner = THIS_MODULE,
920 .obj_size = sizeof(struct raw_sock),
921 .init = raw_init,
922 };
923
924 static const struct can_proto raw_can_proto = {
925 .type = SOCK_RAW,
926 .protocol = CAN_RAW,
927 .ops = &raw_ops,
928 .prot = &raw_proto,
929 };
930
931 static struct notifier_block canraw_notifier = {
932 .notifier_call = raw_notifier
933 };
934
raw_module_init(void)935 static __init int raw_module_init(void)
936 {
937 int err;
938
939 pr_info("can: raw protocol\n");
940
941 err = can_proto_register(&raw_can_proto);
942 if (err < 0)
943 pr_err("can: registration of raw protocol failed\n");
944 else
945 register_netdevice_notifier(&canraw_notifier);
946
947 return err;
948 }
949
raw_module_exit(void)950 static __exit void raw_module_exit(void)
951 {
952 can_proto_unregister(&raw_can_proto);
953 unregister_netdevice_notifier(&canraw_notifier);
954 }
955
956 module_init(raw_module_init);
957 module_exit(raw_module_exit);
958
