xref: /linux/net/can/j1939/socket.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2010-2011 EIA Electronics,
3 //                         Pieter Beyens <pieter.beyens@eia.be>
4 // Copyright (c) 2010-2011 EIA Electronics,
5 //                         Kurt Van Dijck <kurt.van.dijck@eia.be>
6 // Copyright (c) 2018 Protonic,
7 //                         Robin van der Gracht <robin@protonic.nl>
8 // Copyright (c) 2017-2019 Pengutronix,
9 //                         Marc Kleine-Budde <kernel@pengutronix.de>
10 // Copyright (c) 2017-2019 Pengutronix,
11 //                         Oleksij Rempel <kernel@pengutronix.de>
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/can/core.h>
16 #include <linux/can/skb.h>
17 #include <linux/errqueue.h>
18 #include <linux/if_arp.h>
19 
20 #include "j1939-priv.h"
21 
22 #define J1939_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.j1939)
23 
24 /* conversion function between struct sock::sk_priority from linux and
25  * j1939 priority field
26  */
27 static inline priority_t j1939_prio(u32 sk_priority)
28 {
29 	sk_priority = min(sk_priority, 7U);
30 
31 	return 7 - sk_priority;
32 }
33 
34 static inline u32 j1939_to_sk_priority(priority_t prio)
35 {
36 	return 7 - prio;
37 }
38 
39 /* function to see if pgn is to be evaluated */
40 static inline bool j1939_pgn_is_valid(pgn_t pgn)
41 {
42 	return pgn <= J1939_PGN_MAX;
43 }
44 
45 /* test function to avoid non-zero DA placeholder for pdu1 pgn's */
46 static inline bool j1939_pgn_is_clean_pdu(pgn_t pgn)
47 {
48 	if (j1939_pgn_is_pdu1(pgn))
49 		return !(pgn & 0xff);
50 	else
51 		return true;
52 }
53 
54 static inline void j1939_sock_pending_add(struct sock *sk)
55 {
56 	struct j1939_sock *jsk = j1939_sk(sk);
57 
58 	atomic_inc(&jsk->skb_pending);
59 }
60 
61 static int j1939_sock_pending_get(struct sock *sk)
62 {
63 	struct j1939_sock *jsk = j1939_sk(sk);
64 
65 	return atomic_read(&jsk->skb_pending);
66 }
67 
68 void j1939_sock_pending_del(struct sock *sk)
69 {
70 	struct j1939_sock *jsk = j1939_sk(sk);
71 
72 	/* atomic_dec_return returns the new value */
73 	if (!atomic_dec_return(&jsk->skb_pending))
74 		wake_up(&jsk->waitq);	/* no pending SKB's */
75 }
76 
77 static void j1939_jsk_add(struct j1939_priv *priv, struct j1939_sock *jsk)
78 {
79 	jsk->state |= J1939_SOCK_BOUND;
80 	j1939_priv_get(priv);
81 
82 	spin_lock_bh(&priv->j1939_socks_lock);
83 	list_add_tail(&jsk->list, &priv->j1939_socks);
84 	spin_unlock_bh(&priv->j1939_socks_lock);
85 }
86 
87 static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
88 {
89 	spin_lock_bh(&priv->j1939_socks_lock);
90 	list_del_init(&jsk->list);
91 	spin_unlock_bh(&priv->j1939_socks_lock);
92 
93 	j1939_priv_put(priv);
94 	jsk->state &= ~J1939_SOCK_BOUND;
95 }
96 
97 static bool j1939_sk_queue_session(struct j1939_session *session)
98 {
99 	struct j1939_sock *jsk = j1939_sk(session->sk);
100 	bool empty;
101 
102 	spin_lock_bh(&jsk->sk_session_queue_lock);
103 	empty = list_empty(&jsk->sk_session_queue);
104 	j1939_session_get(session);
105 	list_add_tail(&session->sk_session_queue_entry, &jsk->sk_session_queue);
106 	spin_unlock_bh(&jsk->sk_session_queue_lock);
107 	j1939_sock_pending_add(&jsk->sk);
108 
109 	return empty;
110 }
111 
112 static struct
113 j1939_session *j1939_sk_get_incomplete_session(struct j1939_sock *jsk)
114 {
115 	struct j1939_session *session = NULL;
116 
117 	spin_lock_bh(&jsk->sk_session_queue_lock);
118 	if (!list_empty(&jsk->sk_session_queue)) {
119 		session = list_last_entry(&jsk->sk_session_queue,
120 					  struct j1939_session,
121 					  sk_session_queue_entry);
122 		if (session->total_queued_size == session->total_message_size)
123 			session = NULL;
124 		else
125 			j1939_session_get(session);
126 	}
127 	spin_unlock_bh(&jsk->sk_session_queue_lock);
128 
129 	return session;
130 }
131 
132 static void j1939_sk_queue_drop_all(struct j1939_priv *priv,
133 				    struct j1939_sock *jsk, int err)
134 {
135 	struct j1939_session *session, *tmp;
136 
137 	netdev_dbg(priv->ndev, "%s: err: %i\n", __func__, err);
138 	spin_lock_bh(&jsk->sk_session_queue_lock);
139 	list_for_each_entry_safe(session, tmp, &jsk->sk_session_queue,
140 				 sk_session_queue_entry) {
141 		list_del_init(&session->sk_session_queue_entry);
142 		session->err = err;
143 		j1939_session_put(session);
144 	}
145 	spin_unlock_bh(&jsk->sk_session_queue_lock);
146 }
147 
148 static void j1939_sk_queue_activate_next_locked(struct j1939_session *session)
149 {
150 	struct j1939_sock *jsk;
151 	struct j1939_session *first;
152 	int err;
153 
154 	/* RX-Session don't have a socket (yet) */
155 	if (!session->sk)
156 		return;
157 
158 	jsk = j1939_sk(session->sk);
159 	lockdep_assert_held(&jsk->sk_session_queue_lock);
160 
161 	err = session->err;
162 
163 	first = list_first_entry_or_null(&jsk->sk_session_queue,
164 					 struct j1939_session,
165 					 sk_session_queue_entry);
166 
167 	/* Some else has already activated the next session */
168 	if (first != session)
169 		return;
170 
171 activate_next:
172 	list_del_init(&first->sk_session_queue_entry);
173 	j1939_session_put(first);
174 	first = list_first_entry_or_null(&jsk->sk_session_queue,
175 					 struct j1939_session,
176 					 sk_session_queue_entry);
177 	if (!first)
178 		return;
179 
180 	if (WARN_ON_ONCE(j1939_session_activate(first))) {
181 		first->err = -EBUSY;
182 		goto activate_next;
183 	} else {
184 		/* Give receiver some time (arbitrary chosen) to recover */
185 		int time_ms = 0;
186 
187 		if (err)
188 			time_ms = 10 + prandom_u32_max(16);
189 
190 		j1939_tp_schedule_txtimer(first, time_ms);
191 	}
192 }
193 
194 void j1939_sk_queue_activate_next(struct j1939_session *session)
195 {
196 	struct j1939_sock *jsk;
197 
198 	if (!session->sk)
199 		return;
200 
201 	jsk = j1939_sk(session->sk);
202 
203 	spin_lock_bh(&jsk->sk_session_queue_lock);
204 	j1939_sk_queue_activate_next_locked(session);
205 	spin_unlock_bh(&jsk->sk_session_queue_lock);
206 }
207 
208 static bool j1939_sk_match_dst(struct j1939_sock *jsk,
209 			       const struct j1939_sk_buff_cb *skcb)
210 {
211 	if ((jsk->state & J1939_SOCK_PROMISC))
212 		return true;
213 
214 	/* Destination address filter */
215 	if (jsk->addr.src_name && skcb->addr.dst_name) {
216 		if (jsk->addr.src_name != skcb->addr.dst_name)
217 			return false;
218 	} else {
219 		/* receive (all sockets) if
220 		 * - all packages that match our bind() address
221 		 * - all broadcast on a socket if SO_BROADCAST
222 		 *   is set
223 		 */
224 		if (j1939_address_is_unicast(skcb->addr.da)) {
225 			if (jsk->addr.sa != skcb->addr.da)
226 				return false;
227 		} else if (!sock_flag(&jsk->sk, SOCK_BROADCAST)) {
228 			/* receiving broadcast without SO_BROADCAST
229 			 * flag is not allowed
230 			 */
231 			return false;
232 		}
233 	}
234 
235 	/* Source address filter */
236 	if (jsk->state & J1939_SOCK_CONNECTED) {
237 		/* receive (all sockets) if
238 		 * - all packages that match our connect() name or address
239 		 */
240 		if (jsk->addr.dst_name && skcb->addr.src_name) {
241 			if (jsk->addr.dst_name != skcb->addr.src_name)
242 				return false;
243 		} else {
244 			if (jsk->addr.da != skcb->addr.sa)
245 				return false;
246 		}
247 	}
248 
249 	/* PGN filter */
250 	if (j1939_pgn_is_valid(jsk->pgn_rx_filter) &&
251 	    jsk->pgn_rx_filter != skcb->addr.pgn)
252 		return false;
253 
254 	return true;
255 }
256 
257 /* matches skb control buffer (addr) with a j1939 filter */
258 static bool j1939_sk_match_filter(struct j1939_sock *jsk,
259 				  const struct j1939_sk_buff_cb *skcb)
260 {
261 	const struct j1939_filter *f = jsk->filters;
262 	int nfilter = jsk->nfilters;
263 
264 	if (!nfilter)
265 		/* receive all when no filters are assigned */
266 		return true;
267 
268 	for (; nfilter; ++f, --nfilter) {
269 		if ((skcb->addr.pgn & f->pgn_mask) != f->pgn)
270 			continue;
271 		if ((skcb->addr.sa & f->addr_mask) != f->addr)
272 			continue;
273 		if ((skcb->addr.src_name & f->name_mask) != f->name)
274 			continue;
275 		return true;
276 	}
277 	return false;
278 }
279 
280 static bool j1939_sk_recv_match_one(struct j1939_sock *jsk,
281 				    const struct j1939_sk_buff_cb *skcb)
282 {
283 	if (!(jsk->state & J1939_SOCK_BOUND))
284 		return false;
285 
286 	if (!j1939_sk_match_dst(jsk, skcb))
287 		return false;
288 
289 	if (!j1939_sk_match_filter(jsk, skcb))
290 		return false;
291 
292 	return true;
293 }
294 
295 static void j1939_sk_recv_one(struct j1939_sock *jsk, struct sk_buff *oskb)
296 {
297 	const struct j1939_sk_buff_cb *oskcb = j1939_skb_to_cb(oskb);
298 	struct j1939_sk_buff_cb *skcb;
299 	struct sk_buff *skb;
300 
301 	if (oskb->sk == &jsk->sk)
302 		return;
303 
304 	if (!j1939_sk_recv_match_one(jsk, oskcb))
305 		return;
306 
307 	skb = skb_clone(oskb, GFP_ATOMIC);
308 	if (!skb) {
309 		pr_warn("skb clone failed\n");
310 		return;
311 	}
312 	can_skb_set_owner(skb, oskb->sk);
313 
314 	skcb = j1939_skb_to_cb(skb);
315 	skcb->msg_flags &= ~(MSG_DONTROUTE);
316 	if (skb->sk)
317 		skcb->msg_flags |= MSG_DONTROUTE;
318 
319 	if (sock_queue_rcv_skb(&jsk->sk, skb) < 0)
320 		kfree_skb(skb);
321 }
322 
323 bool j1939_sk_recv_match(struct j1939_priv *priv, struct j1939_sk_buff_cb *skcb)
324 {
325 	struct j1939_sock *jsk;
326 	bool match = false;
327 
328 	spin_lock_bh(&priv->j1939_socks_lock);
329 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
330 		match = j1939_sk_recv_match_one(jsk, skcb);
331 		if (match)
332 			break;
333 	}
334 	spin_unlock_bh(&priv->j1939_socks_lock);
335 
336 	return match;
337 }
338 
339 void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb)
340 {
341 	struct j1939_sock *jsk;
342 
343 	spin_lock_bh(&priv->j1939_socks_lock);
344 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
345 		j1939_sk_recv_one(jsk, skb);
346 	}
347 	spin_unlock_bh(&priv->j1939_socks_lock);
348 }
349 
350 static void j1939_sk_sock_destruct(struct sock *sk)
351 {
352 	struct j1939_sock *jsk = j1939_sk(sk);
353 
354 	/* This function will be call by the generic networking code, when then
355 	 * the socket is ultimately closed (sk->sk_destruct).
356 	 *
357 	 * The race between
358 	 * - processing a received CAN frame
359 	 *   (can_receive -> j1939_can_recv)
360 	 *   and accessing j1939_priv
361 	 * ... and ...
362 	 * - closing a socket
363 	 *   (j1939_can_rx_unregister -> can_rx_unregister)
364 	 *   and calling the final j1939_priv_put()
365 	 *
366 	 * is avoided by calling the final j1939_priv_put() from this
367 	 * RCU deferred cleanup call.
368 	 */
369 	if (jsk->priv) {
370 		j1939_priv_put(jsk->priv);
371 		jsk->priv = NULL;
372 	}
373 
374 	/* call generic CAN sock destruct */
375 	can_sock_destruct(sk);
376 }
377 
378 static int j1939_sk_init(struct sock *sk)
379 {
380 	struct j1939_sock *jsk = j1939_sk(sk);
381 
382 	/* Ensure that "sk" is first member in "struct j1939_sock", so that we
383 	 * can skip it during memset().
384 	 */
385 	BUILD_BUG_ON(offsetof(struct j1939_sock, sk) != 0);
386 	memset((void *)jsk + sizeof(jsk->sk), 0x0,
387 	       sizeof(*jsk) - sizeof(jsk->sk));
388 
389 	INIT_LIST_HEAD(&jsk->list);
390 	init_waitqueue_head(&jsk->waitq);
391 	jsk->sk.sk_priority = j1939_to_sk_priority(6);
392 	jsk->sk.sk_reuse = 1; /* per default */
393 	jsk->addr.sa = J1939_NO_ADDR;
394 	jsk->addr.da = J1939_NO_ADDR;
395 	jsk->addr.pgn = J1939_NO_PGN;
396 	jsk->pgn_rx_filter = J1939_NO_PGN;
397 	atomic_set(&jsk->skb_pending, 0);
398 	spin_lock_init(&jsk->sk_session_queue_lock);
399 	INIT_LIST_HEAD(&jsk->sk_session_queue);
400 	sk->sk_destruct = j1939_sk_sock_destruct;
401 	sk->sk_protocol = CAN_J1939;
402 
403 	return 0;
404 }
405 
406 static int j1939_sk_sanity_check(struct sockaddr_can *addr, int len)
407 {
408 	if (!addr)
409 		return -EDESTADDRREQ;
410 	if (len < J1939_MIN_NAMELEN)
411 		return -EINVAL;
412 	if (addr->can_family != AF_CAN)
413 		return -EINVAL;
414 	if (!addr->can_ifindex)
415 		return -ENODEV;
416 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
417 	    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
418 		return -EINVAL;
419 
420 	return 0;
421 }
422 
423 static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
424 {
425 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
426 	struct j1939_sock *jsk = j1939_sk(sock->sk);
427 	struct j1939_priv *priv;
428 	struct sock *sk;
429 	struct net *net;
430 	int ret = 0;
431 
432 	ret = j1939_sk_sanity_check(addr, len);
433 	if (ret)
434 		return ret;
435 
436 	lock_sock(sock->sk);
437 
438 	priv = jsk->priv;
439 	sk = sock->sk;
440 	net = sock_net(sk);
441 
442 	/* Already bound to an interface? */
443 	if (jsk->state & J1939_SOCK_BOUND) {
444 		/* A re-bind() to a different interface is not
445 		 * supported.
446 		 */
447 		if (jsk->ifindex != addr->can_ifindex) {
448 			ret = -EINVAL;
449 			goto out_release_sock;
450 		}
451 
452 		/* drop old references */
453 		j1939_jsk_del(priv, jsk);
454 		j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
455 	} else {
456 		struct net_device *ndev;
457 
458 		ndev = dev_get_by_index(net, addr->can_ifindex);
459 		if (!ndev) {
460 			ret = -ENODEV;
461 			goto out_release_sock;
462 		}
463 
464 		if (ndev->type != ARPHRD_CAN) {
465 			dev_put(ndev);
466 			ret = -ENODEV;
467 			goto out_release_sock;
468 		}
469 
470 		if (!ndev->ml_priv) {
471 			netdev_warn_once(ndev,
472 					 "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n");
473 			dev_put(ndev);
474 			ret = -ENODEV;
475 			goto out_release_sock;
476 		}
477 
478 		if (!(ndev->flags & IFF_UP)) {
479 			dev_put(ndev);
480 			ret = -ENETDOWN;
481 			goto out_release_sock;
482 		}
483 
484 		priv = j1939_netdev_start(ndev);
485 		dev_put(ndev);
486 		if (IS_ERR(priv)) {
487 			ret = PTR_ERR(priv);
488 			goto out_release_sock;
489 		}
490 
491 		jsk->ifindex = addr->can_ifindex;
492 
493 		/* the corresponding j1939_priv_put() is called via
494 		 * sk->sk_destruct, which points to j1939_sk_sock_destruct()
495 		 */
496 		j1939_priv_get(priv);
497 		jsk->priv = priv;
498 	}
499 
500 	/* set default transmit pgn */
501 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
502 		jsk->pgn_rx_filter = addr->can_addr.j1939.pgn;
503 	jsk->addr.src_name = addr->can_addr.j1939.name;
504 	jsk->addr.sa = addr->can_addr.j1939.addr;
505 
506 	/* get new references */
507 	ret = j1939_local_ecu_get(priv, jsk->addr.src_name, jsk->addr.sa);
508 	if (ret) {
509 		j1939_netdev_stop(priv);
510 		goto out_release_sock;
511 	}
512 
513 	j1939_jsk_add(priv, jsk);
514 
515  out_release_sock: /* fall through */
516 	release_sock(sock->sk);
517 
518 	return ret;
519 }
520 
521 static int j1939_sk_connect(struct socket *sock, struct sockaddr *uaddr,
522 			    int len, int flags)
523 {
524 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
525 	struct j1939_sock *jsk = j1939_sk(sock->sk);
526 	int ret = 0;
527 
528 	ret = j1939_sk_sanity_check(addr, len);
529 	if (ret)
530 		return ret;
531 
532 	lock_sock(sock->sk);
533 
534 	/* bind() before connect() is mandatory */
535 	if (!(jsk->state & J1939_SOCK_BOUND)) {
536 		ret = -EINVAL;
537 		goto out_release_sock;
538 	}
539 
540 	/* A connect() to a different interface is not supported. */
541 	if (jsk->ifindex != addr->can_ifindex) {
542 		ret = -EINVAL;
543 		goto out_release_sock;
544 	}
545 
546 	if (!addr->can_addr.j1939.name &&
547 	    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
548 	    !sock_flag(&jsk->sk, SOCK_BROADCAST)) {
549 		/* broadcast, but SO_BROADCAST not set */
550 		ret = -EACCES;
551 		goto out_release_sock;
552 	}
553 
554 	jsk->addr.dst_name = addr->can_addr.j1939.name;
555 	jsk->addr.da = addr->can_addr.j1939.addr;
556 
557 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
558 		jsk->addr.pgn = addr->can_addr.j1939.pgn;
559 
560 	jsk->state |= J1939_SOCK_CONNECTED;
561 
562  out_release_sock: /* fall through */
563 	release_sock(sock->sk);
564 
565 	return ret;
566 }
567 
568 static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr,
569 				       const struct j1939_sock *jsk, int peer)
570 {
571 	/* There are two holes (2 bytes and 3 bytes) to clear to avoid
572 	 * leaking kernel information to user space.
573 	 */
574 	memset(addr, 0, J1939_MIN_NAMELEN);
575 
576 	addr->can_family = AF_CAN;
577 	addr->can_ifindex = jsk->ifindex;
578 	addr->can_addr.j1939.pgn = jsk->addr.pgn;
579 	if (peer) {
580 		addr->can_addr.j1939.name = jsk->addr.dst_name;
581 		addr->can_addr.j1939.addr = jsk->addr.da;
582 	} else {
583 		addr->can_addr.j1939.name = jsk->addr.src_name;
584 		addr->can_addr.j1939.addr = jsk->addr.sa;
585 	}
586 }
587 
588 static int j1939_sk_getname(struct socket *sock, struct sockaddr *uaddr,
589 			    int peer)
590 {
591 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
592 	struct sock *sk = sock->sk;
593 	struct j1939_sock *jsk = j1939_sk(sk);
594 	int ret = 0;
595 
596 	lock_sock(sk);
597 
598 	if (peer && !(jsk->state & J1939_SOCK_CONNECTED)) {
599 		ret = -EADDRNOTAVAIL;
600 		goto failure;
601 	}
602 
603 	j1939_sk_sock2sockaddr_can(addr, jsk, peer);
604 	ret = J1939_MIN_NAMELEN;
605 
606  failure:
607 	release_sock(sk);
608 
609 	return ret;
610 }
611 
612 static int j1939_sk_release(struct socket *sock)
613 {
614 	struct sock *sk = sock->sk;
615 	struct j1939_sock *jsk;
616 
617 	if (!sk)
618 		return 0;
619 
620 	lock_sock(sk);
621 	jsk = j1939_sk(sk);
622 
623 	if (jsk->state & J1939_SOCK_BOUND) {
624 		struct j1939_priv *priv = jsk->priv;
625 
626 		if (wait_event_interruptible(jsk->waitq,
627 					     !j1939_sock_pending_get(&jsk->sk))) {
628 			j1939_cancel_active_session(priv, sk);
629 			j1939_sk_queue_drop_all(priv, jsk, ESHUTDOWN);
630 		}
631 
632 		j1939_jsk_del(priv, jsk);
633 
634 		j1939_local_ecu_put(priv, jsk->addr.src_name,
635 				    jsk->addr.sa);
636 
637 		j1939_netdev_stop(priv);
638 	}
639 
640 	kfree(jsk->filters);
641 	sock_orphan(sk);
642 	sock->sk = NULL;
643 
644 	release_sock(sk);
645 	sock_put(sk);
646 
647 	return 0;
648 }
649 
650 static int j1939_sk_setsockopt_flag(struct j1939_sock *jsk, sockptr_t optval,
651 				    unsigned int optlen, int flag)
652 {
653 	int tmp;
654 
655 	if (optlen != sizeof(tmp))
656 		return -EINVAL;
657 	if (copy_from_sockptr(&tmp, optval, optlen))
658 		return -EFAULT;
659 	lock_sock(&jsk->sk);
660 	if (tmp)
661 		jsk->state |= flag;
662 	else
663 		jsk->state &= ~flag;
664 	release_sock(&jsk->sk);
665 	return tmp;
666 }
667 
668 static int j1939_sk_setsockopt(struct socket *sock, int level, int optname,
669 			       sockptr_t optval, unsigned int optlen)
670 {
671 	struct sock *sk = sock->sk;
672 	struct j1939_sock *jsk = j1939_sk(sk);
673 	int tmp, count = 0, ret = 0;
674 	struct j1939_filter *filters = NULL, *ofilters;
675 
676 	if (level != SOL_CAN_J1939)
677 		return -EINVAL;
678 
679 	switch (optname) {
680 	case SO_J1939_FILTER:
681 		if (!sockptr_is_null(optval)) {
682 			struct j1939_filter *f;
683 			int c;
684 
685 			if (optlen % sizeof(*filters) != 0)
686 				return -EINVAL;
687 
688 			if (optlen > J1939_FILTER_MAX *
689 			    sizeof(struct j1939_filter))
690 				return -EINVAL;
691 
692 			count = optlen / sizeof(*filters);
693 			filters = memdup_sockptr(optval, optlen);
694 			if (IS_ERR(filters))
695 				return PTR_ERR(filters);
696 
697 			for (f = filters, c = count; c; f++, c--) {
698 				f->name &= f->name_mask;
699 				f->pgn &= f->pgn_mask;
700 				f->addr &= f->addr_mask;
701 			}
702 		}
703 
704 		lock_sock(&jsk->sk);
705 		ofilters = jsk->filters;
706 		jsk->filters = filters;
707 		jsk->nfilters = count;
708 		release_sock(&jsk->sk);
709 		kfree(ofilters);
710 		return 0;
711 	case SO_J1939_PROMISC:
712 		return j1939_sk_setsockopt_flag(jsk, optval, optlen,
713 						J1939_SOCK_PROMISC);
714 	case SO_J1939_ERRQUEUE:
715 		ret = j1939_sk_setsockopt_flag(jsk, optval, optlen,
716 					       J1939_SOCK_ERRQUEUE);
717 		if (ret < 0)
718 			return ret;
719 
720 		if (!(jsk->state & J1939_SOCK_ERRQUEUE))
721 			skb_queue_purge(&sk->sk_error_queue);
722 		return ret;
723 	case SO_J1939_SEND_PRIO:
724 		if (optlen != sizeof(tmp))
725 			return -EINVAL;
726 		if (copy_from_sockptr(&tmp, optval, optlen))
727 			return -EFAULT;
728 		if (tmp < 0 || tmp > 7)
729 			return -EDOM;
730 		if (tmp < 2 && !capable(CAP_NET_ADMIN))
731 			return -EPERM;
732 		lock_sock(&jsk->sk);
733 		jsk->sk.sk_priority = j1939_to_sk_priority(tmp);
734 		release_sock(&jsk->sk);
735 		return 0;
736 	default:
737 		return -ENOPROTOOPT;
738 	}
739 }
740 
741 static int j1939_sk_getsockopt(struct socket *sock, int level, int optname,
742 			       char __user *optval, int __user *optlen)
743 {
744 	struct sock *sk = sock->sk;
745 	struct j1939_sock *jsk = j1939_sk(sk);
746 	int ret, ulen;
747 	/* set defaults for using 'int' properties */
748 	int tmp = 0;
749 	int len = sizeof(tmp);
750 	void *val = &tmp;
751 
752 	if (level != SOL_CAN_J1939)
753 		return -EINVAL;
754 	if (get_user(ulen, optlen))
755 		return -EFAULT;
756 	if (ulen < 0)
757 		return -EINVAL;
758 
759 	lock_sock(&jsk->sk);
760 	switch (optname) {
761 	case SO_J1939_PROMISC:
762 		tmp = (jsk->state & J1939_SOCK_PROMISC) ? 1 : 0;
763 		break;
764 	case SO_J1939_ERRQUEUE:
765 		tmp = (jsk->state & J1939_SOCK_ERRQUEUE) ? 1 : 0;
766 		break;
767 	case SO_J1939_SEND_PRIO:
768 		tmp = j1939_prio(jsk->sk.sk_priority);
769 		break;
770 	default:
771 		ret = -ENOPROTOOPT;
772 		goto no_copy;
773 	}
774 
775 	/* copy to user, based on 'len' & 'val'
776 	 * but most sockopt's are 'int' properties, and have 'len' & 'val'
777 	 * left unchanged, but instead modified 'tmp'
778 	 */
779 	if (len > ulen)
780 		ret = -EFAULT;
781 	else if (put_user(len, optlen))
782 		ret = -EFAULT;
783 	else if (copy_to_user(optval, val, len))
784 		ret = -EFAULT;
785 	else
786 		ret = 0;
787  no_copy:
788 	release_sock(&jsk->sk);
789 	return ret;
790 }
791 
792 static int j1939_sk_recvmsg(struct socket *sock, struct msghdr *msg,
793 			    size_t size, int flags)
794 {
795 	struct sock *sk = sock->sk;
796 	struct sk_buff *skb;
797 	struct j1939_sk_buff_cb *skcb;
798 	int ret = 0;
799 
800 	if (flags & ~(MSG_DONTWAIT | MSG_ERRQUEUE))
801 		return -EINVAL;
802 
803 	if (flags & MSG_ERRQUEUE)
804 		return sock_recv_errqueue(sock->sk, msg, size, SOL_CAN_J1939,
805 					  SCM_J1939_ERRQUEUE);
806 
807 	skb = skb_recv_datagram(sk, flags, 0, &ret);
808 	if (!skb)
809 		return ret;
810 
811 	if (size < skb->len)
812 		msg->msg_flags |= MSG_TRUNC;
813 	else
814 		size = skb->len;
815 
816 	ret = memcpy_to_msg(msg, skb->data, size);
817 	if (ret < 0) {
818 		skb_free_datagram(sk, skb);
819 		return ret;
820 	}
821 
822 	skcb = j1939_skb_to_cb(skb);
823 	if (j1939_address_is_valid(skcb->addr.da))
824 		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_ADDR,
825 			 sizeof(skcb->addr.da), &skcb->addr.da);
826 
827 	if (skcb->addr.dst_name)
828 		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_NAME,
829 			 sizeof(skcb->addr.dst_name), &skcb->addr.dst_name);
830 
831 	put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_PRIO,
832 		 sizeof(skcb->priority), &skcb->priority);
833 
834 	if (msg->msg_name) {
835 		struct sockaddr_can *paddr = msg->msg_name;
836 
837 		msg->msg_namelen = J1939_MIN_NAMELEN;
838 		memset(msg->msg_name, 0, msg->msg_namelen);
839 		paddr->can_family = AF_CAN;
840 		paddr->can_ifindex = skb->skb_iif;
841 		paddr->can_addr.j1939.name = skcb->addr.src_name;
842 		paddr->can_addr.j1939.addr = skcb->addr.sa;
843 		paddr->can_addr.j1939.pgn = skcb->addr.pgn;
844 	}
845 
846 	sock_recv_ts_and_drops(msg, sk, skb);
847 	msg->msg_flags |= skcb->msg_flags;
848 	skb_free_datagram(sk, skb);
849 
850 	return size;
851 }
852 
853 static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
854 					  struct sock *sk,
855 					  struct msghdr *msg, size_t size,
856 					  int *errcode)
857 {
858 	struct j1939_sock *jsk = j1939_sk(sk);
859 	struct j1939_sk_buff_cb *skcb;
860 	struct sk_buff *skb;
861 	int ret;
862 
863 	skb = sock_alloc_send_skb(sk,
864 				  size +
865 				  sizeof(struct can_frame) -
866 				  sizeof(((struct can_frame *)NULL)->data) +
867 				  sizeof(struct can_skb_priv),
868 				  msg->msg_flags & MSG_DONTWAIT, &ret);
869 	if (!skb)
870 		goto failure;
871 
872 	can_skb_reserve(skb);
873 	can_skb_prv(skb)->ifindex = ndev->ifindex;
874 	can_skb_prv(skb)->skbcnt = 0;
875 	skb_reserve(skb, offsetof(struct can_frame, data));
876 
877 	ret = memcpy_from_msg(skb_put(skb, size), msg, size);
878 	if (ret < 0)
879 		goto free_skb;
880 
881 	skb->dev = ndev;
882 
883 	skcb = j1939_skb_to_cb(skb);
884 	memset(skcb, 0, sizeof(*skcb));
885 	skcb->addr = jsk->addr;
886 	skcb->priority = j1939_prio(sk->sk_priority);
887 
888 	if (msg->msg_name) {
889 		struct sockaddr_can *addr = msg->msg_name;
890 
891 		if (addr->can_addr.j1939.name ||
892 		    addr->can_addr.j1939.addr != J1939_NO_ADDR) {
893 			skcb->addr.dst_name = addr->can_addr.j1939.name;
894 			skcb->addr.da = addr->can_addr.j1939.addr;
895 		}
896 		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
897 			skcb->addr.pgn = addr->can_addr.j1939.pgn;
898 	}
899 
900 	*errcode = ret;
901 	return skb;
902 
903 free_skb:
904 	kfree_skb(skb);
905 failure:
906 	*errcode = ret;
907 	return NULL;
908 }
909 
910 static size_t j1939_sk_opt_stats_get_size(void)
911 {
912 	return
913 		nla_total_size(sizeof(u32)) + /* J1939_NLA_BYTES_ACKED */
914 		0;
915 }
916 
917 static struct sk_buff *
918 j1939_sk_get_timestamping_opt_stats(struct j1939_session *session)
919 {
920 	struct sk_buff *stats;
921 	u32 size;
922 
923 	stats = alloc_skb(j1939_sk_opt_stats_get_size(), GFP_ATOMIC);
924 	if (!stats)
925 		return NULL;
926 
927 	if (session->skcb.addr.type == J1939_SIMPLE)
928 		size = session->total_message_size;
929 	else
930 		size = min(session->pkt.tx_acked * 7,
931 			   session->total_message_size);
932 
933 	nla_put_u32(stats, J1939_NLA_BYTES_ACKED, size);
934 
935 	return stats;
936 }
937 
938 void j1939_sk_errqueue(struct j1939_session *session,
939 		       enum j1939_sk_errqueue_type type)
940 {
941 	struct j1939_priv *priv = session->priv;
942 	struct sock *sk = session->sk;
943 	struct j1939_sock *jsk;
944 	struct sock_exterr_skb *serr;
945 	struct sk_buff *skb;
946 	char *state = "UNK";
947 	int err;
948 
949 	/* currently we have no sk for the RX session */
950 	if (!sk)
951 		return;
952 
953 	jsk = j1939_sk(sk);
954 
955 	if (!(jsk->state & J1939_SOCK_ERRQUEUE))
956 		return;
957 
958 	skb = j1939_sk_get_timestamping_opt_stats(session);
959 	if (!skb)
960 		return;
961 
962 	skb->tstamp = ktime_get_real();
963 
964 	BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb));
965 
966 	serr = SKB_EXT_ERR(skb);
967 	memset(serr, 0, sizeof(*serr));
968 	switch (type) {
969 	case J1939_ERRQUEUE_ACK:
970 		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_ACK)) {
971 			kfree_skb(skb);
972 			return;
973 		}
974 
975 		serr->ee.ee_errno = ENOMSG;
976 		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
977 		serr->ee.ee_info = SCM_TSTAMP_ACK;
978 		state = "ACK";
979 		break;
980 	case J1939_ERRQUEUE_SCHED:
981 		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED)) {
982 			kfree_skb(skb);
983 			return;
984 		}
985 
986 		serr->ee.ee_errno = ENOMSG;
987 		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
988 		serr->ee.ee_info = SCM_TSTAMP_SCHED;
989 		state = "SCH";
990 		break;
991 	case J1939_ERRQUEUE_ABORT:
992 		serr->ee.ee_errno = session->err;
993 		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
994 		serr->ee.ee_info = J1939_EE_INFO_TX_ABORT;
995 		state = "ABT";
996 		break;
997 	default:
998 		netdev_err(priv->ndev, "Unknown errqueue type %i\n", type);
999 	}
1000 
1001 	serr->opt_stats = true;
1002 	if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
1003 		serr->ee.ee_data = session->tskey;
1004 
1005 	netdev_dbg(session->priv->ndev, "%s: 0x%p tskey: %i, state: %s\n",
1006 		   __func__, session, session->tskey, state);
1007 	err = sock_queue_err_skb(sk, skb);
1008 
1009 	if (err)
1010 		kfree_skb(skb);
1011 };
1012 
1013 void j1939_sk_send_loop_abort(struct sock *sk, int err)
1014 {
1015 	sk->sk_err = err;
1016 
1017 	sk->sk_error_report(sk);
1018 }
1019 
1020 static int j1939_sk_send_loop(struct j1939_priv *priv,  struct sock *sk,
1021 			      struct msghdr *msg, size_t size)
1022 
1023 {
1024 	struct j1939_sock *jsk = j1939_sk(sk);
1025 	struct j1939_session *session = j1939_sk_get_incomplete_session(jsk);
1026 	struct sk_buff *skb;
1027 	size_t segment_size, todo_size;
1028 	int ret = 0;
1029 
1030 	if (session &&
1031 	    session->total_message_size != session->total_queued_size + size) {
1032 		j1939_session_put(session);
1033 		return -EIO;
1034 	}
1035 
1036 	todo_size = size;
1037 
1038 	while (todo_size) {
1039 		struct j1939_sk_buff_cb *skcb;
1040 
1041 		segment_size = min_t(size_t, J1939_MAX_TP_PACKET_SIZE,
1042 				     todo_size);
1043 
1044 		/* Allocate skb for one segment */
1045 		skb = j1939_sk_alloc_skb(priv->ndev, sk, msg, segment_size,
1046 					 &ret);
1047 		if (ret)
1048 			break;
1049 
1050 		skcb = j1939_skb_to_cb(skb);
1051 
1052 		if (!session) {
1053 			/* at this point the size should be full size
1054 			 * of the session
1055 			 */
1056 			skcb->offset = 0;
1057 			session = j1939_tp_send(priv, skb, size);
1058 			if (IS_ERR(session)) {
1059 				ret = PTR_ERR(session);
1060 				goto kfree_skb;
1061 			}
1062 			if (j1939_sk_queue_session(session)) {
1063 				/* try to activate session if we a
1064 				 * fist in the queue
1065 				 */
1066 				if (!j1939_session_activate(session)) {
1067 					j1939_tp_schedule_txtimer(session, 0);
1068 				} else {
1069 					ret = -EBUSY;
1070 					session->err = ret;
1071 					j1939_sk_queue_drop_all(priv, jsk,
1072 								EBUSY);
1073 					break;
1074 				}
1075 			}
1076 		} else {
1077 			skcb->offset = session->total_queued_size;
1078 			j1939_session_skb_queue(session, skb);
1079 		}
1080 
1081 		todo_size -= segment_size;
1082 		session->total_queued_size += segment_size;
1083 	}
1084 
1085 	switch (ret) {
1086 	case 0: /* OK */
1087 		if (todo_size)
1088 			netdev_warn(priv->ndev,
1089 				    "no error found and not completely queued?! %zu\n",
1090 				    todo_size);
1091 		ret = size;
1092 		break;
1093 	case -ERESTARTSYS:
1094 		ret = -EINTR;
1095 		fallthrough;
1096 	case -EAGAIN: /* OK */
1097 		if (todo_size != size)
1098 			ret = size - todo_size;
1099 		break;
1100 	default: /* ERROR */
1101 		break;
1102 	}
1103 
1104 	if (session)
1105 		j1939_session_put(session);
1106 
1107 	return ret;
1108 
1109  kfree_skb:
1110 	kfree_skb(skb);
1111 	return ret;
1112 }
1113 
1114 static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
1115 			    size_t size)
1116 {
1117 	struct sock *sk = sock->sk;
1118 	struct j1939_sock *jsk = j1939_sk(sk);
1119 	struct j1939_priv *priv;
1120 	int ifindex;
1121 	int ret;
1122 
1123 	lock_sock(sock->sk);
1124 	/* various socket state tests */
1125 	if (!(jsk->state & J1939_SOCK_BOUND)) {
1126 		ret = -EBADFD;
1127 		goto sendmsg_done;
1128 	}
1129 
1130 	priv = jsk->priv;
1131 	ifindex = jsk->ifindex;
1132 
1133 	if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR) {
1134 		/* no source address assigned yet */
1135 		ret = -EBADFD;
1136 		goto sendmsg_done;
1137 	}
1138 
1139 	/* deal with provided destination address info */
1140 	if (msg->msg_name) {
1141 		struct sockaddr_can *addr = msg->msg_name;
1142 
1143 		if (msg->msg_namelen < J1939_MIN_NAMELEN) {
1144 			ret = -EINVAL;
1145 			goto sendmsg_done;
1146 		}
1147 
1148 		if (addr->can_family != AF_CAN) {
1149 			ret = -EINVAL;
1150 			goto sendmsg_done;
1151 		}
1152 
1153 		if (addr->can_ifindex && addr->can_ifindex != ifindex) {
1154 			ret = -EBADFD;
1155 			goto sendmsg_done;
1156 		}
1157 
1158 		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
1159 		    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn)) {
1160 			ret = -EINVAL;
1161 			goto sendmsg_done;
1162 		}
1163 
1164 		if (!addr->can_addr.j1939.name &&
1165 		    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
1166 		    !sock_flag(sk, SOCK_BROADCAST)) {
1167 			/* broadcast, but SO_BROADCAST not set */
1168 			ret = -EACCES;
1169 			goto sendmsg_done;
1170 		}
1171 	} else {
1172 		if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
1173 		    !sock_flag(sk, SOCK_BROADCAST)) {
1174 			/* broadcast, but SO_BROADCAST not set */
1175 			ret = -EACCES;
1176 			goto sendmsg_done;
1177 		}
1178 	}
1179 
1180 	ret = j1939_sk_send_loop(priv, sk, msg, size);
1181 
1182 sendmsg_done:
1183 	release_sock(sock->sk);
1184 
1185 	return ret;
1186 }
1187 
1188 void j1939_sk_netdev_event_netdown(struct j1939_priv *priv)
1189 {
1190 	struct j1939_sock *jsk;
1191 	int error_code = ENETDOWN;
1192 
1193 	spin_lock_bh(&priv->j1939_socks_lock);
1194 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
1195 		jsk->sk.sk_err = error_code;
1196 		if (!sock_flag(&jsk->sk, SOCK_DEAD))
1197 			jsk->sk.sk_error_report(&jsk->sk);
1198 
1199 		j1939_sk_queue_drop_all(priv, jsk, error_code);
1200 	}
1201 	spin_unlock_bh(&priv->j1939_socks_lock);
1202 }
1203 
1204 static int j1939_sk_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1205 				unsigned long arg)
1206 {
1207 	/* no ioctls for socket layer -> hand it down to NIC layer */
1208 	return -ENOIOCTLCMD;
1209 }
1210 
1211 static const struct proto_ops j1939_ops = {
1212 	.family = PF_CAN,
1213 	.release = j1939_sk_release,
1214 	.bind = j1939_sk_bind,
1215 	.connect = j1939_sk_connect,
1216 	.socketpair = sock_no_socketpair,
1217 	.accept = sock_no_accept,
1218 	.getname = j1939_sk_getname,
1219 	.poll = datagram_poll,
1220 	.ioctl = j1939_sk_no_ioctlcmd,
1221 	.listen = sock_no_listen,
1222 	.shutdown = sock_no_shutdown,
1223 	.setsockopt = j1939_sk_setsockopt,
1224 	.getsockopt = j1939_sk_getsockopt,
1225 	.sendmsg = j1939_sk_sendmsg,
1226 	.recvmsg = j1939_sk_recvmsg,
1227 	.mmap = sock_no_mmap,
1228 	.sendpage = sock_no_sendpage,
1229 };
1230 
1231 static struct proto j1939_proto __read_mostly = {
1232 	.name = "CAN_J1939",
1233 	.owner = THIS_MODULE,
1234 	.obj_size = sizeof(struct j1939_sock),
1235 	.init = j1939_sk_init,
1236 };
1237 
1238 const struct can_proto j1939_can_proto = {
1239 	.type = SOCK_DGRAM,
1240 	.protocol = CAN_J1939,
1241 	.ops = &j1939_ops,
1242 	.prot = &j1939_proto,
1243 };
1244