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
59 MODULE_DESCRIPTION("PF_CAN raw protocol");
60 MODULE_LICENSE("Dual BSD/GPL");
61 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
62 MODULE_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
77 struct uniqframe {
78 int skbcnt;
79 const struct sk_buff *skb;
80 unsigned int join_rx_count;
81 };
82
83 struct 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 struct can_raw_vcid_options raw_vcid_opts;
95 canid_t tx_vcid_shifted;
96 canid_t rx_vcid_shifted;
97 canid_t rx_vcid_mask_shifted;
98 int join_filters;
99 int count; /* number of active filters */
100 struct can_filter dfilter; /* default/single filter */
101 struct can_filter *filter; /* pointer to filter(s) */
102 can_err_mask_t err_mask;
103 struct uniqframe __percpu *uniq;
104 };
105
106 static LIST_HEAD(raw_notifier_list);
107 static DEFINE_SPINLOCK(raw_notifier_lock);
108 static struct raw_sock *raw_busy_notifier;
109
110 /* Return pointer to store the extra msg flags for raw_recvmsg().
111 * We use the space of one unsigned int beyond the 'struct sockaddr_can'
112 * in skb->cb.
113 */
raw_flags(struct sk_buff * skb)114 static inline unsigned int *raw_flags(struct sk_buff *skb)
115 {
116 sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
117 sizeof(unsigned int));
118
119 /* return pointer after struct sockaddr_can */
120 return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
121 }
122
raw_sk(const struct sock * sk)123 static inline struct raw_sock *raw_sk(const struct sock *sk)
124 {
125 return (struct raw_sock *)sk;
126 }
127
raw_rcv(struct sk_buff * oskb,void * data)128 static void raw_rcv(struct sk_buff *oskb, void *data)
129 {
130 struct sock *sk = (struct sock *)data;
131 struct raw_sock *ro = raw_sk(sk);
132 enum skb_drop_reason reason;
133 struct sockaddr_can *addr;
134 struct sk_buff *skb;
135 unsigned int *pflags;
136
137 /* check the received tx sock reference */
138 if (!ro->recv_own_msgs && oskb->sk == sk)
139 return;
140
141 /* make sure to not pass oversized frames to the socket */
142 if (!ro->fd_frames && can_is_canfd_skb(oskb))
143 return;
144
145 if (can_is_canxl_skb(oskb)) {
146 struct canxl_frame *cxl = (struct canxl_frame *)oskb->data;
147
148 /* make sure to not pass oversized frames to the socket */
149 if (!ro->xl_frames)
150 return;
151
152 /* filter CAN XL VCID content */
153 if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_RX_FILTER) {
154 /* apply VCID filter if user enabled the filter */
155 if ((cxl->prio & ro->rx_vcid_mask_shifted) !=
156 (ro->rx_vcid_shifted & ro->rx_vcid_mask_shifted))
157 return;
158 } else {
159 /* no filter => do not forward VCID tagged frames */
160 if (cxl->prio & CANXL_VCID_MASK)
161 return;
162 }
163 }
164
165 /* eliminate multiple filter matches for the same skb */
166 if (this_cpu_ptr(ro->uniq)->skb == oskb &&
167 this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
168 if (!ro->join_filters)
169 return;
170
171 this_cpu_inc(ro->uniq->join_rx_count);
172 /* drop frame until all enabled filters matched */
173 if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
174 return;
175 } else {
176 this_cpu_ptr(ro->uniq)->skb = oskb;
177 this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt;
178 this_cpu_ptr(ro->uniq)->join_rx_count = 1;
179 /* drop first frame to check all enabled filters? */
180 if (ro->join_filters && ro->count > 1)
181 return;
182 }
183
184 /* clone the given skb to be able to enqueue it into the rcv queue */
185 skb = skb_clone(oskb, GFP_ATOMIC);
186 if (!skb)
187 return;
188
189 /* Put the datagram to the queue so that raw_recvmsg() can get
190 * it from there. We need to pass the interface index to
191 * raw_recvmsg(). We pass a whole struct sockaddr_can in
192 * skb->cb containing the interface index.
193 */
194
195 sock_skb_cb_check_size(sizeof(struct sockaddr_can));
196 addr = (struct sockaddr_can *)skb->cb;
197 memset(addr, 0, sizeof(*addr));
198 addr->can_family = AF_CAN;
199 addr->can_ifindex = skb->dev->ifindex;
200
201 /* add CAN specific message flags for raw_recvmsg() */
202 pflags = raw_flags(skb);
203 *pflags = 0;
204 if (oskb->sk)
205 *pflags |= MSG_DONTROUTE;
206 if (oskb->sk == sk)
207 *pflags |= MSG_CONFIRM;
208
209 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0)
210 sk_skb_reason_drop(sk, skb, reason);
211 }
212
raw_enable_filters(struct net * net,struct net_device * dev,struct sock * sk,struct can_filter * filter,int count)213 static int raw_enable_filters(struct net *net, struct net_device *dev,
214 struct sock *sk, struct can_filter *filter,
215 int count)
216 {
217 int err = 0;
218 int i;
219
220 for (i = 0; i < count; i++) {
221 err = can_rx_register(net, dev, filter[i].can_id,
222 filter[i].can_mask,
223 raw_rcv, sk, "raw", sk);
224 if (err) {
225 /* clean up successfully registered filters */
226 while (--i >= 0)
227 can_rx_unregister(net, dev, filter[i].can_id,
228 filter[i].can_mask,
229 raw_rcv, sk);
230 break;
231 }
232 }
233
234 return err;
235 }
236
raw_enable_errfilter(struct net * net,struct net_device * dev,struct sock * sk,can_err_mask_t err_mask)237 static int raw_enable_errfilter(struct net *net, struct net_device *dev,
238 struct sock *sk, can_err_mask_t err_mask)
239 {
240 int err = 0;
241
242 if (err_mask)
243 err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
244 raw_rcv, sk, "raw", sk);
245
246 return err;
247 }
248
raw_disable_filters(struct net * net,struct net_device * dev,struct sock * sk,struct can_filter * filter,int count)249 static void raw_disable_filters(struct net *net, struct net_device *dev,
250 struct sock *sk, struct can_filter *filter,
251 int count)
252 {
253 int i;
254
255 for (i = 0; i < count; i++)
256 can_rx_unregister(net, dev, filter[i].can_id,
257 filter[i].can_mask, raw_rcv, sk);
258 }
259
raw_disable_errfilter(struct net * net,struct net_device * dev,struct sock * sk,can_err_mask_t err_mask)260 static inline void raw_disable_errfilter(struct net *net,
261 struct net_device *dev,
262 struct sock *sk,
263 can_err_mask_t err_mask)
264
265 {
266 if (err_mask)
267 can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
268 raw_rcv, sk);
269 }
270
raw_disable_allfilters(struct net * net,struct net_device * dev,struct sock * sk)271 static inline void raw_disable_allfilters(struct net *net,
272 struct net_device *dev,
273 struct sock *sk)
274 {
275 struct raw_sock *ro = raw_sk(sk);
276
277 raw_disable_filters(net, dev, sk, ro->filter, ro->count);
278 raw_disable_errfilter(net, dev, sk, ro->err_mask);
279 }
280
raw_enable_allfilters(struct net * net,struct net_device * dev,struct sock * sk)281 static int raw_enable_allfilters(struct net *net, struct net_device *dev,
282 struct sock *sk)
283 {
284 struct raw_sock *ro = raw_sk(sk);
285 int err;
286
287 err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
288 if (!err) {
289 err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
290 if (err)
291 raw_disable_filters(net, dev, sk, ro->filter,
292 ro->count);
293 }
294
295 return err;
296 }
297
raw_notify(struct raw_sock * ro,unsigned long msg,struct net_device * dev)298 static void raw_notify(struct raw_sock *ro, unsigned long msg,
299 struct net_device *dev)
300 {
301 struct sock *sk = &ro->sk;
302
303 if (!net_eq(dev_net(dev), sock_net(sk)))
304 return;
305
306 if (ro->dev != dev)
307 return;
308
309 switch (msg) {
310 case NETDEV_UNREGISTER:
311 lock_sock(sk);
312 /* remove current filters & unregister */
313 if (ro->bound) {
314 raw_disable_allfilters(dev_net(dev), dev, sk);
315 netdev_put(dev, &ro->dev_tracker);
316 }
317
318 if (ro->count > 1)
319 kfree(ro->filter);
320
321 ro->ifindex = 0;
322 ro->bound = 0;
323 ro->dev = NULL;
324 ro->count = 0;
325 release_sock(sk);
326
327 sk->sk_err = ENODEV;
328 if (!sock_flag(sk, SOCK_DEAD))
329 sk_error_report(sk);
330 break;
331
332 case NETDEV_DOWN:
333 sk->sk_err = ENETDOWN;
334 if (!sock_flag(sk, SOCK_DEAD))
335 sk_error_report(sk);
336 break;
337 }
338 }
339
raw_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)340 static int raw_notifier(struct notifier_block *nb, unsigned long msg,
341 void *ptr)
342 {
343 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
344
345 if (dev->type != ARPHRD_CAN)
346 return NOTIFY_DONE;
347 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
348 return NOTIFY_DONE;
349 if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
350 return NOTIFY_DONE;
351
352 spin_lock(&raw_notifier_lock);
353 list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
354 spin_unlock(&raw_notifier_lock);
355 raw_notify(raw_busy_notifier, msg, dev);
356 spin_lock(&raw_notifier_lock);
357 }
358 raw_busy_notifier = NULL;
359 spin_unlock(&raw_notifier_lock);
360 return NOTIFY_DONE;
361 }
362
raw_init(struct sock * sk)363 static int raw_init(struct sock *sk)
364 {
365 struct raw_sock *ro = raw_sk(sk);
366
367 ro->bound = 0;
368 ro->ifindex = 0;
369 ro->dev = NULL;
370
371 /* set default filter to single entry dfilter */
372 ro->dfilter.can_id = 0;
373 ro->dfilter.can_mask = MASK_ALL;
374 ro->filter = &ro->dfilter;
375 ro->count = 1;
376
377 /* set default loopback behaviour */
378 ro->loopback = 1;
379 ro->recv_own_msgs = 0;
380 ro->fd_frames = 0;
381 ro->xl_frames = 0;
382 ro->join_filters = 0;
383
384 /* alloc_percpu provides zero'ed memory */
385 ro->uniq = alloc_percpu(struct uniqframe);
386 if (unlikely(!ro->uniq))
387 return -ENOMEM;
388
389 /* set notifier */
390 spin_lock(&raw_notifier_lock);
391 list_add_tail(&ro->notifier, &raw_notifier_list);
392 spin_unlock(&raw_notifier_lock);
393
394 return 0;
395 }
396
raw_release(struct socket * sock)397 static int raw_release(struct socket *sock)
398 {
399 struct sock *sk = sock->sk;
400 struct raw_sock *ro;
401 struct net *net;
402
403 if (!sk)
404 return 0;
405
406 ro = raw_sk(sk);
407 net = sock_net(sk);
408
409 spin_lock(&raw_notifier_lock);
410 while (raw_busy_notifier == ro) {
411 spin_unlock(&raw_notifier_lock);
412 schedule_timeout_uninterruptible(1);
413 spin_lock(&raw_notifier_lock);
414 }
415 list_del(&ro->notifier);
416 spin_unlock(&raw_notifier_lock);
417
418 rtnl_lock();
419 lock_sock(sk);
420
421 /* remove current filters & unregister */
422 if (ro->bound) {
423 if (ro->dev) {
424 raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk);
425 netdev_put(ro->dev, &ro->dev_tracker);
426 } else {
427 raw_disable_allfilters(net, NULL, sk);
428 }
429 }
430
431 if (ro->count > 1)
432 kfree(ro->filter);
433
434 ro->ifindex = 0;
435 ro->bound = 0;
436 ro->dev = NULL;
437 ro->count = 0;
438 free_percpu(ro->uniq);
439
440 sock_orphan(sk);
441 sock->sk = NULL;
442
443 release_sock(sk);
444 rtnl_unlock();
445
446 sock_prot_inuse_add(net, sk->sk_prot, -1);
447 sock_put(sk);
448
449 return 0;
450 }
451
raw_bind(struct socket * sock,struct sockaddr * uaddr,int len)452 static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
453 {
454 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
455 struct sock *sk = sock->sk;
456 struct raw_sock *ro = raw_sk(sk);
457 struct net_device *dev = NULL;
458 int ifindex;
459 int err = 0;
460 int notify_enetdown = 0;
461
462 if (len < RAW_MIN_NAMELEN)
463 return -EINVAL;
464 if (addr->can_family != AF_CAN)
465 return -EINVAL;
466
467 rtnl_lock();
468 lock_sock(sk);
469
470 if (ro->bound && addr->can_ifindex == ro->ifindex)
471 goto out;
472
473 if (addr->can_ifindex) {
474 dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
475 if (!dev) {
476 err = -ENODEV;
477 goto out;
478 }
479 if (dev->type != ARPHRD_CAN) {
480 err = -ENODEV;
481 goto out_put_dev;
482 }
483
484 if (!(dev->flags & IFF_UP))
485 notify_enetdown = 1;
486
487 ifindex = dev->ifindex;
488
489 /* filters set by default/setsockopt */
490 err = raw_enable_allfilters(sock_net(sk), dev, sk);
491 if (err)
492 goto out_put_dev;
493
494 } else {
495 ifindex = 0;
496
497 /* filters set by default/setsockopt */
498 err = raw_enable_allfilters(sock_net(sk), NULL, sk);
499 }
500
501 if (!err) {
502 if (ro->bound) {
503 /* unregister old filters */
504 if (ro->dev) {
505 raw_disable_allfilters(dev_net(ro->dev),
506 ro->dev, sk);
507 /* drop reference to old ro->dev */
508 netdev_put(ro->dev, &ro->dev_tracker);
509 } else {
510 raw_disable_allfilters(sock_net(sk), NULL, sk);
511 }
512 }
513 ro->ifindex = ifindex;
514 ro->bound = 1;
515 /* bind() ok -> hold a reference for new ro->dev */
516 ro->dev = dev;
517 if (ro->dev)
518 netdev_hold(ro->dev, &ro->dev_tracker, GFP_KERNEL);
519 }
520
521 out_put_dev:
522 /* remove potential reference from dev_get_by_index() */
523 dev_put(dev);
524 out:
525 release_sock(sk);
526 rtnl_unlock();
527
528 if (notify_enetdown) {
529 sk->sk_err = ENETDOWN;
530 if (!sock_flag(sk, SOCK_DEAD))
531 sk_error_report(sk);
532 }
533
534 return err;
535 }
536
raw_getname(struct socket * sock,struct sockaddr * uaddr,int peer)537 static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
538 int peer)
539 {
540 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
541 struct sock *sk = sock->sk;
542 struct raw_sock *ro = raw_sk(sk);
543
544 if (peer)
545 return -EOPNOTSUPP;
546
547 memset(addr, 0, RAW_MIN_NAMELEN);
548 addr->can_family = AF_CAN;
549 addr->can_ifindex = ro->ifindex;
550
551 return RAW_MIN_NAMELEN;
552 }
553
raw_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)554 static int raw_setsockopt(struct socket *sock, int level, int optname,
555 sockptr_t optval, unsigned int optlen)
556 {
557 struct sock *sk = sock->sk;
558 struct raw_sock *ro = raw_sk(sk);
559 struct can_filter *filter = NULL; /* dyn. alloc'ed filters */
560 struct can_filter sfilter; /* single filter */
561 struct net_device *dev = NULL;
562 can_err_mask_t err_mask = 0;
563 int fd_frames;
564 int count = 0;
565 int err = 0;
566
567 if (level != SOL_CAN_RAW)
568 return -EINVAL;
569
570 switch (optname) {
571 case CAN_RAW_FILTER:
572 if (optlen % sizeof(struct can_filter) != 0)
573 return -EINVAL;
574
575 if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
576 return -EINVAL;
577
578 count = optlen / sizeof(struct can_filter);
579
580 if (count > 1) {
581 /* filter does not fit into dfilter => alloc space */
582 filter = memdup_sockptr(optval, optlen);
583 if (IS_ERR(filter))
584 return PTR_ERR(filter);
585 } else if (count == 1) {
586 if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter)))
587 return -EFAULT;
588 }
589
590 rtnl_lock();
591 lock_sock(sk);
592
593 dev = ro->dev;
594 if (ro->bound && dev) {
595 if (dev->reg_state != NETREG_REGISTERED) {
596 if (count > 1)
597 kfree(filter);
598 err = -ENODEV;
599 goto out_fil;
600 }
601 }
602
603 if (ro->bound) {
604 /* (try to) register the new filters */
605 if (count == 1)
606 err = raw_enable_filters(sock_net(sk), dev, sk,
607 &sfilter, 1);
608 else
609 err = raw_enable_filters(sock_net(sk), dev, sk,
610 filter, count);
611 if (err) {
612 if (count > 1)
613 kfree(filter);
614 goto out_fil;
615 }
616
617 /* remove old filter registrations */
618 raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
619 ro->count);
620 }
621
622 /* remove old filter space */
623 if (ro->count > 1)
624 kfree(ro->filter);
625
626 /* link new filters to the socket */
627 if (count == 1) {
628 /* copy filter data for single filter */
629 ro->dfilter = sfilter;
630 filter = &ro->dfilter;
631 }
632 ro->filter = filter;
633 ro->count = count;
634
635 out_fil:
636 release_sock(sk);
637 rtnl_unlock();
638
639 break;
640
641 case CAN_RAW_ERR_FILTER:
642 if (optlen != sizeof(err_mask))
643 return -EINVAL;
644
645 if (copy_from_sockptr(&err_mask, optval, optlen))
646 return -EFAULT;
647
648 err_mask &= CAN_ERR_MASK;
649
650 rtnl_lock();
651 lock_sock(sk);
652
653 dev = ro->dev;
654 if (ro->bound && dev) {
655 if (dev->reg_state != NETREG_REGISTERED) {
656 err = -ENODEV;
657 goto out_err;
658 }
659 }
660
661 /* remove current error mask */
662 if (ro->bound) {
663 /* (try to) register the new err_mask */
664 err = raw_enable_errfilter(sock_net(sk), dev, sk,
665 err_mask);
666
667 if (err)
668 goto out_err;
669
670 /* remove old err_mask registration */
671 raw_disable_errfilter(sock_net(sk), dev, sk,
672 ro->err_mask);
673 }
674
675 /* link new err_mask to the socket */
676 ro->err_mask = err_mask;
677
678 out_err:
679 release_sock(sk);
680 rtnl_unlock();
681
682 break;
683
684 case CAN_RAW_LOOPBACK:
685 if (optlen != sizeof(ro->loopback))
686 return -EINVAL;
687
688 if (copy_from_sockptr(&ro->loopback, optval, optlen))
689 return -EFAULT;
690
691 break;
692
693 case CAN_RAW_RECV_OWN_MSGS:
694 if (optlen != sizeof(ro->recv_own_msgs))
695 return -EINVAL;
696
697 if (copy_from_sockptr(&ro->recv_own_msgs, optval, optlen))
698 return -EFAULT;
699
700 break;
701
702 case CAN_RAW_FD_FRAMES:
703 if (optlen != sizeof(fd_frames))
704 return -EINVAL;
705
706 if (copy_from_sockptr(&fd_frames, optval, optlen))
707 return -EFAULT;
708
709 /* Enabling CAN XL includes CAN FD */
710 if (ro->xl_frames && !fd_frames)
711 return -EINVAL;
712
713 ro->fd_frames = fd_frames;
714 break;
715
716 case CAN_RAW_XL_FRAMES:
717 if (optlen != sizeof(ro->xl_frames))
718 return -EINVAL;
719
720 if (copy_from_sockptr(&ro->xl_frames, optval, optlen))
721 return -EFAULT;
722
723 /* Enabling CAN XL includes CAN FD */
724 if (ro->xl_frames)
725 ro->fd_frames = ro->xl_frames;
726 break;
727
728 case CAN_RAW_XL_VCID_OPTS:
729 if (optlen != sizeof(ro->raw_vcid_opts))
730 return -EINVAL;
731
732 if (copy_from_sockptr(&ro->raw_vcid_opts, optval, optlen))
733 return -EFAULT;
734
735 /* prepare 32 bit values for handling in hot path */
736 ro->tx_vcid_shifted = ro->raw_vcid_opts.tx_vcid << CANXL_VCID_OFFSET;
737 ro->rx_vcid_shifted = ro->raw_vcid_opts.rx_vcid << CANXL_VCID_OFFSET;
738 ro->rx_vcid_mask_shifted = ro->raw_vcid_opts.rx_vcid_mask << CANXL_VCID_OFFSET;
739 break;
740
741 case CAN_RAW_JOIN_FILTERS:
742 if (optlen != sizeof(ro->join_filters))
743 return -EINVAL;
744
745 if (copy_from_sockptr(&ro->join_filters, optval, optlen))
746 return -EFAULT;
747
748 break;
749
750 default:
751 return -ENOPROTOOPT;
752 }
753 return err;
754 }
755
raw_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)756 static int raw_getsockopt(struct socket *sock, int level, int optname,
757 char __user *optval, int __user *optlen)
758 {
759 struct sock *sk = sock->sk;
760 struct raw_sock *ro = raw_sk(sk);
761 int len;
762 void *val;
763
764 if (level != SOL_CAN_RAW)
765 return -EINVAL;
766 if (get_user(len, optlen))
767 return -EFAULT;
768 if (len < 0)
769 return -EINVAL;
770
771 switch (optname) {
772 case CAN_RAW_FILTER: {
773 int err = 0;
774
775 lock_sock(sk);
776 if (ro->count > 0) {
777 int fsize = ro->count * sizeof(struct can_filter);
778
779 /* user space buffer to small for filter list? */
780 if (len < fsize) {
781 /* return -ERANGE and needed space in optlen */
782 err = -ERANGE;
783 if (put_user(fsize, optlen))
784 err = -EFAULT;
785 } else {
786 if (len > fsize)
787 len = fsize;
788 if (copy_to_user(optval, ro->filter, len))
789 err = -EFAULT;
790 }
791 } else {
792 len = 0;
793 }
794 release_sock(sk);
795
796 if (!err)
797 err = put_user(len, optlen);
798 return err;
799 }
800 case CAN_RAW_ERR_FILTER:
801 if (len > sizeof(can_err_mask_t))
802 len = sizeof(can_err_mask_t);
803 val = &ro->err_mask;
804 break;
805
806 case CAN_RAW_LOOPBACK:
807 if (len > sizeof(int))
808 len = sizeof(int);
809 val = &ro->loopback;
810 break;
811
812 case CAN_RAW_RECV_OWN_MSGS:
813 if (len > sizeof(int))
814 len = sizeof(int);
815 val = &ro->recv_own_msgs;
816 break;
817
818 case CAN_RAW_FD_FRAMES:
819 if (len > sizeof(int))
820 len = sizeof(int);
821 val = &ro->fd_frames;
822 break;
823
824 case CAN_RAW_XL_FRAMES:
825 if (len > sizeof(int))
826 len = sizeof(int);
827 val = &ro->xl_frames;
828 break;
829
830 case CAN_RAW_XL_VCID_OPTS: {
831 int err = 0;
832
833 /* user space buffer to small for VCID opts? */
834 if (len < sizeof(ro->raw_vcid_opts)) {
835 /* return -ERANGE and needed space in optlen */
836 err = -ERANGE;
837 if (put_user(sizeof(ro->raw_vcid_opts), optlen))
838 err = -EFAULT;
839 } else {
840 if (len > sizeof(ro->raw_vcid_opts))
841 len = sizeof(ro->raw_vcid_opts);
842 if (copy_to_user(optval, &ro->raw_vcid_opts, len))
843 err = -EFAULT;
844 }
845 if (!err)
846 err = put_user(len, optlen);
847 return err;
848 }
849 case CAN_RAW_JOIN_FILTERS:
850 if (len > sizeof(int))
851 len = sizeof(int);
852 val = &ro->join_filters;
853 break;
854
855 default:
856 return -ENOPROTOOPT;
857 }
858
859 if (put_user(len, optlen))
860 return -EFAULT;
861 if (copy_to_user(optval, val, len))
862 return -EFAULT;
863 return 0;
864 }
865
raw_put_canxl_vcid(struct raw_sock * ro,struct sk_buff * skb)866 static void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb)
867 {
868 struct canxl_frame *cxl = (struct canxl_frame *)skb->data;
869
870 /* sanitize non CAN XL bits */
871 cxl->prio &= (CANXL_PRIO_MASK | CANXL_VCID_MASK);
872
873 /* clear VCID in CAN XL frame if pass through is disabled */
874 if (!(ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_PASS))
875 cxl->prio &= CANXL_PRIO_MASK;
876
877 /* set VCID in CAN XL frame if enabled */
878 if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_SET) {
879 cxl->prio &= CANXL_PRIO_MASK;
880 cxl->prio |= ro->tx_vcid_shifted;
881 }
882 }
883
raw_check_txframe(struct raw_sock * ro,struct sk_buff * skb,int mtu)884 static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu)
885 {
886 /* Classical CAN -> no checks for flags and device capabilities */
887 if (can_is_can_skb(skb))
888 return CAN_MTU;
889
890 /* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */
891 if (ro->fd_frames && can_is_canfd_skb(skb) &&
892 (mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu)))
893 return CANFD_MTU;
894
895 /* CAN XL -> needs to be enabled and a CAN XL device */
896 if (ro->xl_frames && can_is_canxl_skb(skb) &&
897 can_is_canxl_dev_mtu(mtu))
898 return CANXL_MTU;
899
900 return 0;
901 }
902
raw_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)903 static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
904 {
905 struct sock *sk = sock->sk;
906 struct raw_sock *ro = raw_sk(sk);
907 struct sockcm_cookie sockc;
908 struct sk_buff *skb;
909 struct net_device *dev;
910 unsigned int txmtu;
911 int ifindex;
912 int err = -EINVAL;
913
914 /* check for valid CAN frame sizes */
915 if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU)
916 return -EINVAL;
917
918 if (msg->msg_name) {
919 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
920
921 if (msg->msg_namelen < RAW_MIN_NAMELEN)
922 return -EINVAL;
923
924 if (addr->can_family != AF_CAN)
925 return -EINVAL;
926
927 ifindex = addr->can_ifindex;
928 } else {
929 ifindex = ro->ifindex;
930 }
931
932 dev = dev_get_by_index(sock_net(sk), ifindex);
933 if (!dev)
934 return -ENXIO;
935
936 skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
937 msg->msg_flags & MSG_DONTWAIT, &err);
938 if (!skb)
939 goto put_dev;
940
941 can_skb_reserve(skb);
942 can_skb_prv(skb)->ifindex = dev->ifindex;
943 can_skb_prv(skb)->skbcnt = 0;
944
945 /* fill the skb before testing for valid CAN frames */
946 err = memcpy_from_msg(skb_put(skb, size), msg, size);
947 if (err < 0)
948 goto free_skb;
949
950 err = -EINVAL;
951
952 /* check for valid CAN (CC/FD/XL) frame content */
953 txmtu = raw_check_txframe(ro, skb, dev->mtu);
954 if (!txmtu)
955 goto free_skb;
956
957 /* only CANXL: clear/forward/set VCID value */
958 if (txmtu == CANXL_MTU)
959 raw_put_canxl_vcid(ro, skb);
960
961 sockcm_init(&sockc, sk);
962 if (msg->msg_controllen) {
963 err = sock_cmsg_send(sk, msg, &sockc);
964 if (unlikely(err))
965 goto free_skb;
966 }
967
968 skb->dev = dev;
969 skb->priority = sockc.priority;
970 skb->mark = sockc.mark;
971 skb->tstamp = sockc.transmit_time;
972
973 skb_setup_tx_timestamp(skb, &sockc);
974
975 err = can_send(skb, ro->loopback);
976
977 dev_put(dev);
978
979 if (err)
980 goto send_failed;
981
982 return size;
983
984 free_skb:
985 kfree_skb(skb);
986 put_dev:
987 dev_put(dev);
988 send_failed:
989 return err;
990 }
991
raw_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)992 static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
993 int flags)
994 {
995 struct sock *sk = sock->sk;
996 struct sk_buff *skb;
997 int err = 0;
998
999 if (flags & MSG_ERRQUEUE)
1000 return sock_recv_errqueue(sk, msg, size,
1001 SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
1002
1003 skb = skb_recv_datagram(sk, flags, &err);
1004 if (!skb)
1005 return err;
1006
1007 if (size < skb->len)
1008 msg->msg_flags |= MSG_TRUNC;
1009 else
1010 size = skb->len;
1011
1012 err = memcpy_to_msg(msg, skb->data, size);
1013 if (err < 0) {
1014 skb_free_datagram(sk, skb);
1015 return err;
1016 }
1017
1018 sock_recv_cmsgs(msg, sk, skb);
1019
1020 if (msg->msg_name) {
1021 __sockaddr_check_size(RAW_MIN_NAMELEN);
1022 msg->msg_namelen = RAW_MIN_NAMELEN;
1023 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1024 }
1025
1026 /* assign the flags that have been recorded in raw_rcv() */
1027 msg->msg_flags |= *(raw_flags(skb));
1028
1029 skb_free_datagram(sk, skb);
1030
1031 return size;
1032 }
1033
raw_sock_no_ioctlcmd(struct socket * sock,unsigned int cmd,unsigned long arg)1034 static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1035 unsigned long arg)
1036 {
1037 /* no ioctls for socket layer -> hand it down to NIC layer */
1038 return -ENOIOCTLCMD;
1039 }
1040
1041 static const struct proto_ops raw_ops = {
1042 .family = PF_CAN,
1043 .release = raw_release,
1044 .bind = raw_bind,
1045 .connect = sock_no_connect,
1046 .socketpair = sock_no_socketpair,
1047 .accept = sock_no_accept,
1048 .getname = raw_getname,
1049 .poll = datagram_poll,
1050 .ioctl = raw_sock_no_ioctlcmd,
1051 .gettstamp = sock_gettstamp,
1052 .listen = sock_no_listen,
1053 .shutdown = sock_no_shutdown,
1054 .setsockopt = raw_setsockopt,
1055 .getsockopt = raw_getsockopt,
1056 .sendmsg = raw_sendmsg,
1057 .recvmsg = raw_recvmsg,
1058 .mmap = sock_no_mmap,
1059 };
1060
1061 static struct proto raw_proto __read_mostly = {
1062 .name = "CAN_RAW",
1063 .owner = THIS_MODULE,
1064 .obj_size = sizeof(struct raw_sock),
1065 .init = raw_init,
1066 };
1067
1068 static const struct can_proto raw_can_proto = {
1069 .type = SOCK_RAW,
1070 .protocol = CAN_RAW,
1071 .ops = &raw_ops,
1072 .prot = &raw_proto,
1073 };
1074
1075 static struct notifier_block canraw_notifier = {
1076 .notifier_call = raw_notifier
1077 };
1078
raw_module_init(void)1079 static __init int raw_module_init(void)
1080 {
1081 int err;
1082
1083 pr_info("can: raw protocol\n");
1084
1085 err = register_netdevice_notifier(&canraw_notifier);
1086 if (err)
1087 return err;
1088
1089 err = can_proto_register(&raw_can_proto);
1090 if (err < 0) {
1091 pr_err("can: registration of raw protocol failed\n");
1092 goto register_proto_failed;
1093 }
1094
1095 return 0;
1096
1097 register_proto_failed:
1098 unregister_netdevice_notifier(&canraw_notifier);
1099 return err;
1100 }
1101
raw_module_exit(void)1102 static __exit void raw_module_exit(void)
1103 {
1104 can_proto_unregister(&raw_can_proto);
1105 unregister_netdevice_notifier(&canraw_notifier);
1106 }
1107
1108 module_init(raw_module_init);
1109 module_exit(raw_module_exit);
1110