xref: /linux/net/can/j1939/socket.c (revision 9f10374bb024593a611e6845847f0444841a231b)
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/can-ml.h>
16 #include <linux/can/core.h>
17 #include <linux/can/skb.h>
18 #include <linux/errqueue.h>
19 #include <linux/if_arp.h>
20 #include <net/can.h>
21 
22 #include "j1939-priv.h"
23 
24 #define J1939_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.j1939)
25 
26 /* conversion function between struct sock::sk_priority from linux and
27  * j1939 priority field
28  */
29 static inline priority_t j1939_prio(u32 sk_priority)
30 {
31 	sk_priority = min(sk_priority, 7U);
32 
33 	return 7 - sk_priority;
34 }
35 
36 static inline u32 j1939_to_sk_priority(priority_t prio)
37 {
38 	return 7 - prio;
39 }
40 
41 /* function to see if pgn is to be evaluated */
42 static inline bool j1939_pgn_is_valid(pgn_t pgn)
43 {
44 	return pgn <= J1939_PGN_MAX;
45 }
46 
47 /* test function to avoid non-zero DA placeholder for pdu1 pgn's */
48 static inline bool j1939_pgn_is_clean_pdu(pgn_t pgn)
49 {
50 	if (j1939_pgn_is_pdu1(pgn))
51 		return !(pgn & 0xff);
52 	else
53 		return true;
54 }
55 
56 static inline void j1939_sock_pending_add(struct sock *sk)
57 {
58 	struct j1939_sock *jsk = j1939_sk(sk);
59 
60 	atomic_inc(&jsk->skb_pending);
61 }
62 
63 static int j1939_sock_pending_get(struct sock *sk)
64 {
65 	struct j1939_sock *jsk = j1939_sk(sk);
66 
67 	return atomic_read(&jsk->skb_pending);
68 }
69 
70 void j1939_sock_pending_del(struct sock *sk)
71 {
72 	struct j1939_sock *jsk = j1939_sk(sk);
73 
74 	/* atomic_dec_return returns the new value */
75 	if (!atomic_dec_return(&jsk->skb_pending))
76 		wake_up(&jsk->waitq);	/* no pending SKB's */
77 }
78 
79 static void j1939_jsk_add(struct j1939_priv *priv, struct j1939_sock *jsk)
80 {
81 	jsk->state |= J1939_SOCK_BOUND;
82 	j1939_priv_get(priv);
83 
84 	write_lock_bh(&priv->j1939_socks_lock);
85 	list_add_tail(&jsk->list, &priv->j1939_socks);
86 	write_unlock_bh(&priv->j1939_socks_lock);
87 }
88 
89 static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
90 {
91 	write_lock_bh(&priv->j1939_socks_lock);
92 	list_del_init(&jsk->list);
93 	write_unlock_bh(&priv->j1939_socks_lock);
94 
95 	j1939_priv_put(priv);
96 	jsk->state &= ~J1939_SOCK_BOUND;
97 }
98 
99 static bool j1939_sk_queue_session(struct j1939_session *session)
100 {
101 	struct j1939_sock *jsk = j1939_sk(session->sk);
102 	bool empty;
103 
104 	spin_lock_bh(&jsk->sk_session_queue_lock);
105 	empty = list_empty(&jsk->sk_session_queue);
106 	j1939_session_get(session);
107 	list_add_tail(&session->sk_session_queue_entry, &jsk->sk_session_queue);
108 	spin_unlock_bh(&jsk->sk_session_queue_lock);
109 	j1939_sock_pending_add(&jsk->sk);
110 
111 	return empty;
112 }
113 
114 static struct
115 j1939_session *j1939_sk_get_incomplete_session(struct j1939_sock *jsk)
116 {
117 	struct j1939_session *session = NULL;
118 
119 	spin_lock_bh(&jsk->sk_session_queue_lock);
120 	if (!list_empty(&jsk->sk_session_queue)) {
121 		session = list_last_entry(&jsk->sk_session_queue,
122 					  struct j1939_session,
123 					  sk_session_queue_entry);
124 		if (session->total_queued_size == session->total_message_size)
125 			session = NULL;
126 		else
127 			j1939_session_get(session);
128 	}
129 	spin_unlock_bh(&jsk->sk_session_queue_lock);
130 
131 	return session;
132 }
133 
134 static void j1939_sk_queue_drop_all(struct j1939_priv *priv,
135 				    struct j1939_sock *jsk, int err)
136 {
137 	struct j1939_session *session, *tmp;
138 
139 	netdev_dbg(priv->ndev, "%s: err: %i\n", __func__, err);
140 	spin_lock_bh(&jsk->sk_session_queue_lock);
141 	list_for_each_entry_safe(session, tmp, &jsk->sk_session_queue,
142 				 sk_session_queue_entry) {
143 		list_del_init(&session->sk_session_queue_entry);
144 		session->err = err;
145 		j1939_session_put(session);
146 	}
147 	spin_unlock_bh(&jsk->sk_session_queue_lock);
148 }
149 
150 static void j1939_sk_queue_activate_next_locked(struct j1939_session *session)
151 {
152 	struct j1939_sock *jsk;
153 	struct j1939_session *first;
154 	int err;
155 
156 	/* RX-Session don't have a socket (yet) */
157 	if (!session->sk)
158 		return;
159 
160 	jsk = j1939_sk(session->sk);
161 	lockdep_assert_held(&jsk->sk_session_queue_lock);
162 
163 	err = session->err;
164 
165 	first = list_first_entry_or_null(&jsk->sk_session_queue,
166 					 struct j1939_session,
167 					 sk_session_queue_entry);
168 
169 	/* Some else has already activated the next session */
170 	if (first != session)
171 		return;
172 
173 activate_next:
174 	list_del_init(&first->sk_session_queue_entry);
175 	j1939_session_put(first);
176 	first = list_first_entry_or_null(&jsk->sk_session_queue,
177 					 struct j1939_session,
178 					 sk_session_queue_entry);
179 	if (!first)
180 		return;
181 
182 	if (j1939_session_activate(first)) {
183 		netdev_warn_once(first->priv->ndev,
184 				 "%s: 0x%p: Identical session is already activated.\n",
185 				 __func__, first);
186 		first->err = -EBUSY;
187 		goto activate_next;
188 	} else {
189 		/* Give receiver some time (arbitrary chosen) to recover */
190 		int time_ms = 0;
191 
192 		if (err)
193 			time_ms = 10 + get_random_u32_below(16);
194 
195 		j1939_tp_schedule_txtimer(first, time_ms);
196 	}
197 }
198 
199 void j1939_sk_queue_activate_next(struct j1939_session *session)
200 {
201 	struct j1939_sock *jsk;
202 
203 	if (!session->sk)
204 		return;
205 
206 	jsk = j1939_sk(session->sk);
207 
208 	spin_lock_bh(&jsk->sk_session_queue_lock);
209 	j1939_sk_queue_activate_next_locked(session);
210 	spin_unlock_bh(&jsk->sk_session_queue_lock);
211 }
212 
213 static bool j1939_sk_match_dst(struct j1939_sock *jsk,
214 			       const struct j1939_sk_buff_cb *skcb)
215 {
216 	if ((jsk->state & J1939_SOCK_PROMISC))
217 		return true;
218 
219 	/* Destination address filter */
220 	if (jsk->addr.src_name && skcb->addr.dst_name) {
221 		if (jsk->addr.src_name != skcb->addr.dst_name)
222 			return false;
223 	} else {
224 		/* receive (all sockets) if
225 		 * - all packages that match our bind() address
226 		 * - all broadcast on a socket if SO_BROADCAST
227 		 *   is set
228 		 */
229 		if (j1939_address_is_unicast(skcb->addr.da)) {
230 			if (jsk->addr.sa != skcb->addr.da)
231 				return false;
232 		} else if (!sock_flag(&jsk->sk, SOCK_BROADCAST)) {
233 			/* receiving broadcast without SO_BROADCAST
234 			 * flag is not allowed
235 			 */
236 			return false;
237 		}
238 	}
239 
240 	/* Source address filter */
241 	if (jsk->state & J1939_SOCK_CONNECTED) {
242 		/* receive (all sockets) if
243 		 * - all packages that match our connect() name or address
244 		 */
245 		if (jsk->addr.dst_name && skcb->addr.src_name) {
246 			if (jsk->addr.dst_name != skcb->addr.src_name)
247 				return false;
248 		} else {
249 			if (jsk->addr.da != skcb->addr.sa)
250 				return false;
251 		}
252 	}
253 
254 	/* PGN filter */
255 	if (j1939_pgn_is_valid(jsk->pgn_rx_filter) &&
256 	    jsk->pgn_rx_filter != skcb->addr.pgn)
257 		return false;
258 
259 	return true;
260 }
261 
262 /* matches skb control buffer (addr) with a j1939 filter */
263 static bool j1939_sk_match_filter(struct j1939_sock *jsk,
264 				  const struct j1939_sk_buff_cb *skcb)
265 {
266 	const struct j1939_filter *f;
267 	int nfilter;
268 
269 	spin_lock_bh(&jsk->filters_lock);
270 
271 	f = jsk->filters;
272 	nfilter = jsk->nfilters;
273 
274 	if (!nfilter)
275 		/* receive all when no filters are assigned */
276 		goto filter_match_found;
277 
278 	for (; nfilter; ++f, --nfilter) {
279 		if ((skcb->addr.pgn & f->pgn_mask) != f->pgn)
280 			continue;
281 		if ((skcb->addr.sa & f->addr_mask) != f->addr)
282 			continue;
283 		if ((skcb->addr.src_name & f->name_mask) != f->name)
284 			continue;
285 		goto filter_match_found;
286 	}
287 
288 	spin_unlock_bh(&jsk->filters_lock);
289 	return false;
290 
291 filter_match_found:
292 	spin_unlock_bh(&jsk->filters_lock);
293 	return true;
294 }
295 
296 static bool j1939_sk_recv_match_one(struct j1939_sock *jsk,
297 				    const struct j1939_sk_buff_cb *skcb)
298 {
299 	if (!(jsk->state & J1939_SOCK_BOUND))
300 		return false;
301 
302 	if (!j1939_sk_match_dst(jsk, skcb))
303 		return false;
304 
305 	if (!j1939_sk_match_filter(jsk, skcb))
306 		return false;
307 
308 	return true;
309 }
310 
311 static void j1939_sk_recv_one(struct j1939_sock *jsk, struct sk_buff *oskb)
312 {
313 	const struct j1939_sk_buff_cb *oskcb = j1939_skb_to_cb(oskb);
314 	struct j1939_sk_buff_cb *skcb;
315 	enum skb_drop_reason reason;
316 	struct sk_buff *skb;
317 
318 	if (oskb->sk == &jsk->sk)
319 		return;
320 
321 	if (!j1939_sk_recv_match_one(jsk, oskcb))
322 		return;
323 
324 	skb = skb_clone(oskb, GFP_ATOMIC);
325 	if (!skb) {
326 		pr_warn("skb clone failed\n");
327 		return;
328 	}
329 	can_skb_set_owner(skb, oskb->sk);
330 
331 	skcb = j1939_skb_to_cb(skb);
332 	skcb->msg_flags &= ~(MSG_DONTROUTE);
333 	if (skb->sk)
334 		skcb->msg_flags |= MSG_DONTROUTE;
335 
336 	if (sock_queue_rcv_skb_reason(&jsk->sk, skb, &reason) < 0)
337 		sk_skb_reason_drop(&jsk->sk, skb, reason);
338 }
339 
340 bool j1939_sk_recv_match(struct j1939_priv *priv, struct j1939_sk_buff_cb *skcb)
341 {
342 	struct j1939_sock *jsk;
343 	bool match = false;
344 
345 	read_lock_bh(&priv->j1939_socks_lock);
346 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
347 		match = j1939_sk_recv_match_one(jsk, skcb);
348 		if (match)
349 			break;
350 	}
351 	read_unlock_bh(&priv->j1939_socks_lock);
352 
353 	return match;
354 }
355 
356 void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb)
357 {
358 	struct j1939_sock *jsk;
359 
360 	read_lock_bh(&priv->j1939_socks_lock);
361 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
362 		j1939_sk_recv_one(jsk, skb);
363 	}
364 	read_unlock_bh(&priv->j1939_socks_lock);
365 }
366 
367 static void j1939_sk_sock_destruct(struct sock *sk)
368 {
369 	struct j1939_sock *jsk = j1939_sk(sk);
370 
371 	/* This function will be called by the generic networking code, when
372 	 * the socket is ultimately closed (sk->sk_destruct).
373 	 *
374 	 * The race between
375 	 * - processing a received CAN frame
376 	 *   (can_receive -> j1939_can_recv)
377 	 *   and accessing j1939_priv
378 	 * ... and ...
379 	 * - closing a socket
380 	 *   (j1939_can_rx_unregister -> can_rx_unregister)
381 	 *   and calling the final j1939_priv_put()
382 	 *
383 	 * is avoided by calling the final j1939_priv_put() from this
384 	 * RCU deferred cleanup call.
385 	 */
386 	if (jsk->priv) {
387 		j1939_priv_put(jsk->priv);
388 		jsk->priv = NULL;
389 	}
390 
391 	/* call generic CAN sock destruct */
392 	can_sock_destruct(sk);
393 }
394 
395 static int j1939_sk_init(struct sock *sk)
396 {
397 	struct j1939_sock *jsk = j1939_sk(sk);
398 
399 	/* Ensure that "sk" is first member in "struct j1939_sock", so that we
400 	 * can skip it during memset().
401 	 */
402 	BUILD_BUG_ON(offsetof(struct j1939_sock, sk) != 0);
403 	memset((void *)jsk + sizeof(jsk->sk), 0x0,
404 	       sizeof(*jsk) - sizeof(jsk->sk));
405 
406 	INIT_LIST_HEAD(&jsk->list);
407 	init_waitqueue_head(&jsk->waitq);
408 	jsk->sk.sk_priority = j1939_to_sk_priority(6);
409 	jsk->sk.sk_reuse = 1; /* per default */
410 	jsk->addr.sa = J1939_NO_ADDR;
411 	jsk->addr.da = J1939_NO_ADDR;
412 	jsk->addr.pgn = J1939_NO_PGN;
413 	jsk->pgn_rx_filter = J1939_NO_PGN;
414 	atomic_set(&jsk->skb_pending, 0);
415 	spin_lock_init(&jsk->sk_session_queue_lock);
416 	INIT_LIST_HEAD(&jsk->sk_session_queue);
417 	spin_lock_init(&jsk->filters_lock);
418 
419 	/* j1939_sk_sock_destruct() depends on SOCK_RCU_FREE flag */
420 	sock_set_flag(sk, SOCK_RCU_FREE);
421 	sk->sk_destruct = j1939_sk_sock_destruct;
422 	sk->sk_protocol = CAN_J1939;
423 
424 	return 0;
425 }
426 
427 static int j1939_sk_sanity_check(struct sockaddr_can *addr, int len)
428 {
429 	if (!addr)
430 		return -EDESTADDRREQ;
431 	if (len < J1939_MIN_NAMELEN)
432 		return -EINVAL;
433 	if (addr->can_family != AF_CAN)
434 		return -EINVAL;
435 	if (!addr->can_ifindex)
436 		return -ENODEV;
437 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
438 	    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
439 		return -EINVAL;
440 
441 	return 0;
442 }
443 
444 static int j1939_sk_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int len)
445 {
446 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
447 	struct j1939_sock *jsk = j1939_sk(sock->sk);
448 	struct j1939_priv *priv;
449 	struct sock *sk;
450 	struct net *net;
451 	int ret = 0;
452 
453 	ret = j1939_sk_sanity_check(addr, len);
454 	if (ret)
455 		return ret;
456 
457 	lock_sock(sock->sk);
458 
459 	priv = jsk->priv;
460 	sk = sock->sk;
461 	net = sock_net(sk);
462 
463 	/* Already bound to an interface? */
464 	if (jsk->state & J1939_SOCK_BOUND) {
465 		/* A re-bind() to a different interface is not
466 		 * supported.
467 		 */
468 		if (jsk->ifindex != addr->can_ifindex) {
469 			ret = -EINVAL;
470 			goto out_release_sock;
471 		}
472 
473 		/* drop old references */
474 		j1939_jsk_del(priv, jsk);
475 		j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
476 	} else {
477 		struct can_ml_priv *can_ml;
478 		struct net_device *ndev;
479 
480 		ndev = dev_get_by_index(net, addr->can_ifindex);
481 		if (!ndev) {
482 			ret = -ENODEV;
483 			goto out_release_sock;
484 		}
485 
486 		if (ndev->reg_state != NETREG_REGISTERED) {
487 			dev_put(ndev);
488 			ret = -ENODEV;
489 			goto out_release_sock;
490 		}
491 
492 		can_ml = can_get_ml_priv(ndev);
493 		if (!can_ml) {
494 			dev_put(ndev);
495 			ret = -ENODEV;
496 			goto out_release_sock;
497 		}
498 
499 		if (!(ndev->flags & IFF_UP)) {
500 			dev_put(ndev);
501 			ret = -ENETDOWN;
502 			goto out_release_sock;
503 		}
504 
505 		priv = j1939_netdev_start(ndev);
506 		dev_put(ndev);
507 		if (IS_ERR(priv)) {
508 			ret = PTR_ERR(priv);
509 			goto out_release_sock;
510 		}
511 
512 		jsk->ifindex = addr->can_ifindex;
513 
514 		/* the corresponding j1939_priv_put() is called via
515 		 * sk->sk_destruct, which points to j1939_sk_sock_destruct()
516 		 */
517 		j1939_priv_get(priv);
518 		jsk->priv = priv;
519 	}
520 
521 	/* set default transmit pgn */
522 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
523 		jsk->pgn_rx_filter = addr->can_addr.j1939.pgn;
524 	jsk->addr.src_name = addr->can_addr.j1939.name;
525 	jsk->addr.sa = addr->can_addr.j1939.addr;
526 
527 	/* get new references */
528 	ret = j1939_local_ecu_get(priv, jsk->addr.src_name, jsk->addr.sa);
529 	if (ret) {
530 		j1939_netdev_stop(priv);
531 		jsk->priv = NULL;
532 		synchronize_rcu();
533 		j1939_priv_put(priv);
534 		goto out_release_sock;
535 	}
536 
537 	j1939_jsk_add(priv, jsk);
538 
539  out_release_sock: /* fall through */
540 	release_sock(sock->sk);
541 
542 	return ret;
543 }
544 
545 static int j1939_sk_connect(struct socket *sock, struct sockaddr_unsized *uaddr,
546 			    int len, int flags)
547 {
548 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
549 	struct j1939_sock *jsk = j1939_sk(sock->sk);
550 	int ret = 0;
551 
552 	ret = j1939_sk_sanity_check(addr, len);
553 	if (ret)
554 		return ret;
555 
556 	lock_sock(sock->sk);
557 
558 	/* bind() before connect() is mandatory */
559 	if (!(jsk->state & J1939_SOCK_BOUND)) {
560 		ret = -EINVAL;
561 		goto out_release_sock;
562 	}
563 
564 	/* A connect() to a different interface is not supported. */
565 	if (jsk->ifindex != addr->can_ifindex) {
566 		ret = -EINVAL;
567 		goto out_release_sock;
568 	}
569 
570 	if (!addr->can_addr.j1939.name &&
571 	    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
572 	    !sock_flag(&jsk->sk, SOCK_BROADCAST)) {
573 		/* broadcast, but SO_BROADCAST not set */
574 		ret = -EACCES;
575 		goto out_release_sock;
576 	}
577 
578 	jsk->addr.dst_name = addr->can_addr.j1939.name;
579 	jsk->addr.da = addr->can_addr.j1939.addr;
580 
581 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
582 		jsk->addr.pgn = addr->can_addr.j1939.pgn;
583 
584 	jsk->state |= J1939_SOCK_CONNECTED;
585 
586  out_release_sock: /* fall through */
587 	release_sock(sock->sk);
588 
589 	return ret;
590 }
591 
592 static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr,
593 				       const struct j1939_sock *jsk, int peer)
594 {
595 	/* There are two holes (2 bytes and 3 bytes) to clear to avoid
596 	 * leaking kernel information to user space.
597 	 */
598 	memset(addr, 0, J1939_MIN_NAMELEN);
599 
600 	addr->can_family = AF_CAN;
601 	addr->can_ifindex = jsk->ifindex;
602 	addr->can_addr.j1939.pgn = jsk->addr.pgn;
603 	if (peer) {
604 		addr->can_addr.j1939.name = jsk->addr.dst_name;
605 		addr->can_addr.j1939.addr = jsk->addr.da;
606 	} else {
607 		addr->can_addr.j1939.name = jsk->addr.src_name;
608 		addr->can_addr.j1939.addr = jsk->addr.sa;
609 	}
610 }
611 
612 static int j1939_sk_getname(struct socket *sock, struct sockaddr *uaddr,
613 			    int peer)
614 {
615 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
616 	struct sock *sk = sock->sk;
617 	struct j1939_sock *jsk = j1939_sk(sk);
618 	int ret = 0;
619 
620 	lock_sock(sk);
621 
622 	if (peer && !(jsk->state & J1939_SOCK_CONNECTED)) {
623 		ret = -EADDRNOTAVAIL;
624 		goto failure;
625 	}
626 
627 	j1939_sk_sock2sockaddr_can(addr, jsk, peer);
628 	ret = J1939_MIN_NAMELEN;
629 
630  failure:
631 	release_sock(sk);
632 
633 	return ret;
634 }
635 
636 static int j1939_sk_release(struct socket *sock)
637 {
638 	struct sock *sk = sock->sk;
639 	struct j1939_sock *jsk;
640 
641 	if (!sk)
642 		return 0;
643 
644 	lock_sock(sk);
645 	jsk = j1939_sk(sk);
646 
647 	if (jsk->state & J1939_SOCK_BOUND) {
648 		struct j1939_priv *priv = jsk->priv;
649 
650 		if (wait_event_interruptible(jsk->waitq,
651 					     !j1939_sock_pending_get(&jsk->sk))) {
652 			j1939_cancel_active_session(priv, sk);
653 			j1939_sk_queue_drop_all(priv, jsk, ESHUTDOWN);
654 		}
655 
656 		j1939_jsk_del(priv, jsk);
657 
658 		j1939_local_ecu_put(priv, jsk->addr.src_name,
659 				    jsk->addr.sa);
660 
661 		j1939_netdev_stop(priv);
662 	}
663 
664 	kfree(jsk->filters);
665 	sock_orphan(sk);
666 	sock->sk = NULL;
667 
668 	release_sock(sk);
669 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
670 	sock_put(sk);
671 
672 	return 0;
673 }
674 
675 static int j1939_sk_setsockopt_flag(struct j1939_sock *jsk, sockptr_t optval,
676 				    unsigned int optlen, int flag)
677 {
678 	int tmp;
679 
680 	if (optlen != sizeof(tmp))
681 		return -EINVAL;
682 	if (copy_from_sockptr(&tmp, optval, optlen))
683 		return -EFAULT;
684 	lock_sock(&jsk->sk);
685 	if (tmp)
686 		jsk->state |= flag;
687 	else
688 		jsk->state &= ~flag;
689 	release_sock(&jsk->sk);
690 	return tmp;
691 }
692 
693 static int j1939_sk_setsockopt(struct socket *sock, int level, int optname,
694 			       sockptr_t optval, unsigned int optlen)
695 {
696 	struct sock *sk = sock->sk;
697 	struct j1939_sock *jsk = j1939_sk(sk);
698 	int tmp, count = 0, ret = 0;
699 	struct j1939_filter *filters = NULL, *ofilters;
700 
701 	if (level != SOL_CAN_J1939)
702 		return -EINVAL;
703 
704 	switch (optname) {
705 	case SO_J1939_FILTER:
706 		if (!sockptr_is_null(optval) && optlen != 0) {
707 			struct j1939_filter *f;
708 			int c;
709 
710 			if (optlen % sizeof(*filters) != 0)
711 				return -EINVAL;
712 
713 			if (optlen > J1939_FILTER_MAX *
714 			    sizeof(struct j1939_filter))
715 				return -EINVAL;
716 
717 			count = optlen / sizeof(*filters);
718 			filters = memdup_sockptr(optval, optlen);
719 			if (IS_ERR(filters))
720 				return PTR_ERR(filters);
721 
722 			for (f = filters, c = count; c; f++, c--) {
723 				f->name &= f->name_mask;
724 				f->pgn &= f->pgn_mask;
725 				f->addr &= f->addr_mask;
726 			}
727 		}
728 
729 		lock_sock(&jsk->sk);
730 		spin_lock_bh(&jsk->filters_lock);
731 		ofilters = jsk->filters;
732 		jsk->filters = filters;
733 		jsk->nfilters = count;
734 		spin_unlock_bh(&jsk->filters_lock);
735 		release_sock(&jsk->sk);
736 		kfree(ofilters);
737 		return 0;
738 	case SO_J1939_PROMISC:
739 		return j1939_sk_setsockopt_flag(jsk, optval, optlen,
740 						J1939_SOCK_PROMISC);
741 	case SO_J1939_ERRQUEUE:
742 		ret = j1939_sk_setsockopt_flag(jsk, optval, optlen,
743 					       J1939_SOCK_ERRQUEUE);
744 		if (ret < 0)
745 			return ret;
746 
747 		if (!(jsk->state & J1939_SOCK_ERRQUEUE))
748 			skb_queue_purge(&sk->sk_error_queue);
749 		return ret;
750 	case SO_J1939_SEND_PRIO:
751 		if (optlen != sizeof(tmp))
752 			return -EINVAL;
753 		if (copy_from_sockptr(&tmp, optval, optlen))
754 			return -EFAULT;
755 		if (tmp < 0 || tmp > 7)
756 			return -EDOM;
757 		if (tmp < 2 && !capable(CAP_NET_ADMIN))
758 			return -EPERM;
759 		lock_sock(&jsk->sk);
760 		jsk->sk.sk_priority = j1939_to_sk_priority(tmp);
761 		release_sock(&jsk->sk);
762 		return 0;
763 	default:
764 		return -ENOPROTOOPT;
765 	}
766 }
767 
768 static int j1939_sk_getsockopt(struct socket *sock, int level, int optname,
769 			       char __user *optval, int __user *optlen)
770 {
771 	struct sock *sk = sock->sk;
772 	struct j1939_sock *jsk = j1939_sk(sk);
773 	int ret, ulen;
774 	/* set defaults for using 'int' properties */
775 	int tmp = 0;
776 	int len = sizeof(tmp);
777 	void *val = &tmp;
778 
779 	if (level != SOL_CAN_J1939)
780 		return -EINVAL;
781 	if (get_user(ulen, optlen))
782 		return -EFAULT;
783 	if (ulen < 0)
784 		return -EINVAL;
785 
786 	lock_sock(&jsk->sk);
787 	switch (optname) {
788 	case SO_J1939_PROMISC:
789 		tmp = (jsk->state & J1939_SOCK_PROMISC) ? 1 : 0;
790 		break;
791 	case SO_J1939_ERRQUEUE:
792 		tmp = (jsk->state & J1939_SOCK_ERRQUEUE) ? 1 : 0;
793 		break;
794 	case SO_J1939_SEND_PRIO:
795 		tmp = j1939_prio(jsk->sk.sk_priority);
796 		break;
797 	default:
798 		ret = -ENOPROTOOPT;
799 		goto no_copy;
800 	}
801 
802 	/* copy to user, based on 'len' & 'val'
803 	 * but most sockopt's are 'int' properties, and have 'len' & 'val'
804 	 * left unchanged, but instead modified 'tmp'
805 	 */
806 	if (len > ulen)
807 		ret = -EFAULT;
808 	else if (put_user(len, optlen))
809 		ret = -EFAULT;
810 	else if (copy_to_user(optval, val, len))
811 		ret = -EFAULT;
812 	else
813 		ret = 0;
814  no_copy:
815 	release_sock(&jsk->sk);
816 	return ret;
817 }
818 
819 static int j1939_sk_recvmsg(struct socket *sock, struct msghdr *msg,
820 			    size_t size, int flags)
821 {
822 	struct sock *sk = sock->sk;
823 	struct sk_buff *skb;
824 	struct j1939_sk_buff_cb *skcb;
825 	int ret = 0;
826 
827 	if (flags & ~(MSG_DONTWAIT | MSG_ERRQUEUE | MSG_CMSG_COMPAT))
828 		return -EINVAL;
829 
830 	if (flags & MSG_ERRQUEUE)
831 		return sock_recv_errqueue(sock->sk, msg, size, SOL_CAN_J1939,
832 					  SCM_J1939_ERRQUEUE);
833 
834 	skb = skb_recv_datagram(sk, flags, &ret);
835 	if (!skb)
836 		return ret;
837 
838 	if (size < skb->len)
839 		msg->msg_flags |= MSG_TRUNC;
840 	else
841 		size = skb->len;
842 
843 	ret = memcpy_to_msg(msg, skb->data, size);
844 	if (ret < 0) {
845 		skb_free_datagram(sk, skb);
846 		return ret;
847 	}
848 
849 	skcb = j1939_skb_to_cb(skb);
850 	if (j1939_address_is_valid(skcb->addr.da))
851 		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_ADDR,
852 			 sizeof(skcb->addr.da), &skcb->addr.da);
853 
854 	if (skcb->addr.dst_name)
855 		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_NAME,
856 			 sizeof(skcb->addr.dst_name), &skcb->addr.dst_name);
857 
858 	put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_PRIO,
859 		 sizeof(skcb->priority), &skcb->priority);
860 
861 	if (msg->msg_name) {
862 		struct sockaddr_can *paddr = msg->msg_name;
863 
864 		msg->msg_namelen = J1939_MIN_NAMELEN;
865 		memset(msg->msg_name, 0, msg->msg_namelen);
866 		paddr->can_family = AF_CAN;
867 		paddr->can_ifindex = skb->skb_iif;
868 		paddr->can_addr.j1939.name = skcb->addr.src_name;
869 		paddr->can_addr.j1939.addr = skcb->addr.sa;
870 		paddr->can_addr.j1939.pgn = skcb->addr.pgn;
871 	}
872 
873 	sock_recv_cmsgs(msg, sk, skb);
874 	msg->msg_flags |= skcb->msg_flags;
875 	skb_free_datagram(sk, skb);
876 
877 	return size;
878 }
879 
880 static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
881 					  struct sock *sk,
882 					  struct msghdr *msg, size_t size,
883 					  int *errcode)
884 {
885 	struct j1939_sock *jsk = j1939_sk(sk);
886 	struct j1939_sk_buff_cb *skcb;
887 	struct sk_buff *skb;
888 	struct can_skb_ext *csx;
889 	int ret;
890 
891 	skb = sock_alloc_send_skb(sk,
892 				  size +
893 				  sizeof(struct can_frame) -
894 				  sizeof(((struct can_frame *)NULL)->data),
895 				  msg->msg_flags & MSG_DONTWAIT, &ret);
896 	if (!skb)
897 		goto failure;
898 
899 	csx = can_skb_ext_add(skb);
900 	if (!csx) {
901 		kfree_skb(skb);
902 		ret = -ENOMEM;
903 		goto failure;
904 	}
905 
906 	csx->can_iif = ndev->ifindex;
907 	skb_reserve(skb, offsetof(struct can_frame, data));
908 
909 	ret = memcpy_from_msg(skb_put(skb, size), msg, size);
910 	if (ret < 0)
911 		goto free_skb;
912 
913 	skb->dev = ndev;
914 
915 	skcb = j1939_skb_to_cb(skb);
916 	memset(skcb, 0, sizeof(*skcb));
917 	skcb->addr = jsk->addr;
918 	skcb->priority = j1939_prio(READ_ONCE(sk->sk_priority));
919 
920 	if (msg->msg_name) {
921 		struct sockaddr_can *addr = msg->msg_name;
922 
923 		if (addr->can_addr.j1939.name ||
924 		    addr->can_addr.j1939.addr != J1939_NO_ADDR) {
925 			skcb->addr.dst_name = addr->can_addr.j1939.name;
926 			skcb->addr.da = addr->can_addr.j1939.addr;
927 		}
928 		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
929 			skcb->addr.pgn = addr->can_addr.j1939.pgn;
930 	}
931 
932 	*errcode = ret;
933 	return skb;
934 
935 free_skb:
936 	kfree_skb(skb);
937 failure:
938 	*errcode = ret;
939 	return NULL;
940 }
941 
942 static size_t j1939_sk_opt_stats_get_size(enum j1939_sk_errqueue_type type)
943 {
944 	switch (type) {
945 	case J1939_ERRQUEUE_RX_RTS:
946 		return
947 			nla_total_size(sizeof(u32)) + /* J1939_NLA_TOTAL_SIZE */
948 			nla_total_size(sizeof(u32)) + /* J1939_NLA_PGN */
949 			nla_total_size(sizeof(u64)) + /* J1939_NLA_SRC_NAME */
950 			nla_total_size(sizeof(u64)) + /* J1939_NLA_DEST_NAME */
951 			nla_total_size(sizeof(u8)) +  /* J1939_NLA_SRC_ADDR */
952 			nla_total_size(sizeof(u8)) +  /* J1939_NLA_DEST_ADDR */
953 			0;
954 	default:
955 		return
956 			nla_total_size(sizeof(u32)) + /* J1939_NLA_BYTES_ACKED */
957 			0;
958 	}
959 }
960 
961 static struct sk_buff *
962 j1939_sk_get_timestamping_opt_stats(struct j1939_session *session,
963 				    enum j1939_sk_errqueue_type type)
964 {
965 	struct sk_buff *stats;
966 	u32 size;
967 
968 	stats = alloc_skb(j1939_sk_opt_stats_get_size(type), GFP_ATOMIC);
969 	if (!stats)
970 		return NULL;
971 
972 	if (session->skcb.addr.type == J1939_SIMPLE)
973 		size = session->total_message_size;
974 	else
975 		size = min(session->pkt.tx_acked * 7,
976 			   session->total_message_size);
977 
978 	switch (type) {
979 	case J1939_ERRQUEUE_RX_RTS:
980 		nla_put_u32(stats, J1939_NLA_TOTAL_SIZE,
981 			    session->total_message_size);
982 		nla_put_u32(stats, J1939_NLA_PGN,
983 			    session->skcb.addr.pgn);
984 		nla_put_u64_64bit(stats, J1939_NLA_SRC_NAME,
985 				  session->skcb.addr.src_name, J1939_NLA_PAD);
986 		nla_put_u64_64bit(stats, J1939_NLA_DEST_NAME,
987 				  session->skcb.addr.dst_name, J1939_NLA_PAD);
988 		nla_put_u8(stats, J1939_NLA_SRC_ADDR,
989 			   session->skcb.addr.sa);
990 		nla_put_u8(stats, J1939_NLA_DEST_ADDR,
991 			   session->skcb.addr.da);
992 		break;
993 	default:
994 		nla_put_u32(stats, J1939_NLA_BYTES_ACKED, size);
995 	}
996 
997 	return stats;
998 }
999 
1000 static void __j1939_sk_errqueue(struct j1939_session *session, struct sock *sk,
1001 				enum j1939_sk_errqueue_type type)
1002 {
1003 	struct j1939_priv *priv = session->priv;
1004 	struct j1939_sock *jsk;
1005 	struct sock_exterr_skb *serr;
1006 	struct sk_buff *skb;
1007 	char *state = "UNK";
1008 	u32 tsflags;
1009 	int err;
1010 
1011 	jsk = j1939_sk(sk);
1012 
1013 	if (!(jsk->state & J1939_SOCK_ERRQUEUE))
1014 		return;
1015 
1016 	tsflags = READ_ONCE(sk->sk_tsflags);
1017 	switch (type) {
1018 	case J1939_ERRQUEUE_TX_ACK:
1019 		if (!(tsflags & SOF_TIMESTAMPING_TX_ACK))
1020 			return;
1021 		break;
1022 	case J1939_ERRQUEUE_TX_SCHED:
1023 		if (!(tsflags & SOF_TIMESTAMPING_TX_SCHED))
1024 			return;
1025 		break;
1026 	case J1939_ERRQUEUE_TX_ABORT:
1027 		break;
1028 	case J1939_ERRQUEUE_RX_RTS:
1029 		fallthrough;
1030 	case J1939_ERRQUEUE_RX_DPO:
1031 		fallthrough;
1032 	case J1939_ERRQUEUE_RX_ABORT:
1033 		if (!(tsflags & SOF_TIMESTAMPING_RX_SOFTWARE))
1034 			return;
1035 		break;
1036 	default:
1037 		netdev_err(priv->ndev, "Unknown errqueue type %i\n", type);
1038 	}
1039 
1040 	skb = j1939_sk_get_timestamping_opt_stats(session, type);
1041 	if (!skb)
1042 		return;
1043 
1044 	skb->tstamp = ktime_get_real();
1045 
1046 	BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb));
1047 
1048 	serr = SKB_EXT_ERR(skb);
1049 	memset(serr, 0, sizeof(*serr));
1050 	switch (type) {
1051 	case J1939_ERRQUEUE_TX_ACK:
1052 		serr->ee.ee_errno = ENOMSG;
1053 		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
1054 		serr->ee.ee_info = SCM_TSTAMP_ACK;
1055 		state = "TX ACK";
1056 		break;
1057 	case J1939_ERRQUEUE_TX_SCHED:
1058 		serr->ee.ee_errno = ENOMSG;
1059 		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
1060 		serr->ee.ee_info = SCM_TSTAMP_SCHED;
1061 		state = "TX SCH";
1062 		break;
1063 	case J1939_ERRQUEUE_TX_ABORT:
1064 		serr->ee.ee_errno = session->err;
1065 		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
1066 		serr->ee.ee_info = J1939_EE_INFO_TX_ABORT;
1067 		state = "TX ABT";
1068 		break;
1069 	case J1939_ERRQUEUE_RX_RTS:
1070 		serr->ee.ee_errno = ENOMSG;
1071 		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
1072 		serr->ee.ee_info = J1939_EE_INFO_RX_RTS;
1073 		state = "RX RTS";
1074 		break;
1075 	case J1939_ERRQUEUE_RX_DPO:
1076 		serr->ee.ee_errno = ENOMSG;
1077 		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
1078 		serr->ee.ee_info = J1939_EE_INFO_RX_DPO;
1079 		state = "RX DPO";
1080 		break;
1081 	case J1939_ERRQUEUE_RX_ABORT:
1082 		serr->ee.ee_errno = session->err;
1083 		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
1084 		serr->ee.ee_info = J1939_EE_INFO_RX_ABORT;
1085 		state = "RX ABT";
1086 		break;
1087 	}
1088 
1089 	serr->opt_stats = true;
1090 	if (tsflags & SOF_TIMESTAMPING_OPT_ID)
1091 		serr->ee.ee_data = session->tskey;
1092 
1093 	netdev_dbg(session->priv->ndev, "%s: 0x%p tskey: %i, state: %s\n",
1094 		   __func__, session, session->tskey, state);
1095 	err = sock_queue_err_skb(sk, skb);
1096 
1097 	if (err)
1098 		kfree_skb(skb);
1099 };
1100 
1101 void j1939_sk_errqueue(struct j1939_session *session,
1102 		       enum j1939_sk_errqueue_type type)
1103 {
1104 	struct j1939_priv *priv = session->priv;
1105 	struct j1939_sock *jsk;
1106 
1107 	if (session->sk) {
1108 		/* send TX notifications to the socket of origin  */
1109 		__j1939_sk_errqueue(session, session->sk, type);
1110 		return;
1111 	}
1112 
1113 	/* spread RX notifications to all sockets subscribed to this session */
1114 	read_lock_bh(&priv->j1939_socks_lock);
1115 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
1116 		if (j1939_sk_recv_match_one(jsk, &session->skcb))
1117 			__j1939_sk_errqueue(session, &jsk->sk, type);
1118 	}
1119 	read_unlock_bh(&priv->j1939_socks_lock);
1120 };
1121 
1122 void j1939_sk_send_loop_abort(struct sock *sk, int err)
1123 {
1124 	struct j1939_sock *jsk = j1939_sk(sk);
1125 
1126 	if (jsk->state & J1939_SOCK_ERRQUEUE)
1127 		return;
1128 
1129 	sk->sk_err = err;
1130 
1131 	sk_error_report(sk);
1132 }
1133 
1134 static int j1939_sk_send_loop(struct j1939_priv *priv,  struct sock *sk,
1135 			      struct msghdr *msg, size_t size)
1136 
1137 {
1138 	struct j1939_sock *jsk = j1939_sk(sk);
1139 	struct j1939_session *session = j1939_sk_get_incomplete_session(jsk);
1140 	struct sk_buff *skb;
1141 	size_t segment_size, todo_size;
1142 	int ret = 0;
1143 
1144 	if (session &&
1145 	    session->total_message_size != session->total_queued_size + size) {
1146 		j1939_session_put(session);
1147 		return -EIO;
1148 	}
1149 
1150 	todo_size = size;
1151 
1152 	do {
1153 		struct j1939_sk_buff_cb *skcb;
1154 
1155 		segment_size = min_t(size_t, J1939_MAX_TP_PACKET_SIZE,
1156 				     todo_size);
1157 
1158 		/* Allocate skb for one segment */
1159 		skb = j1939_sk_alloc_skb(priv->ndev, sk, msg, segment_size,
1160 					 &ret);
1161 		if (ret)
1162 			break;
1163 
1164 		skcb = j1939_skb_to_cb(skb);
1165 
1166 		if (!session) {
1167 			/* at this point the size should be full size
1168 			 * of the session
1169 			 */
1170 			skcb->offset = 0;
1171 			session = j1939_tp_send(priv, skb, size);
1172 			if (IS_ERR(session)) {
1173 				ret = PTR_ERR(session);
1174 				goto kfree_skb;
1175 			}
1176 			if (j1939_sk_queue_session(session)) {
1177 				/* try to activate session if we a
1178 				 * fist in the queue
1179 				 */
1180 				if (!j1939_session_activate(session)) {
1181 					j1939_tp_schedule_txtimer(session, 0);
1182 				} else {
1183 					ret = -EBUSY;
1184 					session->err = ret;
1185 					j1939_sk_queue_drop_all(priv, jsk,
1186 								EBUSY);
1187 					break;
1188 				}
1189 			}
1190 		} else {
1191 			skcb->offset = session->total_queued_size;
1192 			j1939_session_skb_queue(session, skb);
1193 		}
1194 
1195 		todo_size -= segment_size;
1196 		session->total_queued_size += segment_size;
1197 	} while (todo_size);
1198 
1199 	switch (ret) {
1200 	case 0: /* OK */
1201 		if (todo_size)
1202 			netdev_warn(priv->ndev,
1203 				    "no error found and not completely queued?! %zu\n",
1204 				    todo_size);
1205 		ret = size;
1206 		break;
1207 	case -ERESTARTSYS:
1208 		ret = -EINTR;
1209 		fallthrough;
1210 	case -EAGAIN: /* OK */
1211 		if (todo_size != size)
1212 			ret = size - todo_size;
1213 		break;
1214 	default: /* ERROR */
1215 		break;
1216 	}
1217 
1218 	if (session)
1219 		j1939_session_put(session);
1220 
1221 	return ret;
1222 
1223  kfree_skb:
1224 	kfree_skb(skb);
1225 	return ret;
1226 }
1227 
1228 static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
1229 			    size_t size)
1230 {
1231 	struct sock *sk = sock->sk;
1232 	struct j1939_sock *jsk = j1939_sk(sk);
1233 	struct j1939_priv *priv;
1234 	int ifindex;
1235 	int ret;
1236 
1237 	lock_sock(sock->sk);
1238 	/* various socket state tests */
1239 	if (!(jsk->state & J1939_SOCK_BOUND)) {
1240 		ret = -EBADFD;
1241 		goto sendmsg_done;
1242 	}
1243 
1244 	priv = jsk->priv;
1245 	ifindex = jsk->ifindex;
1246 
1247 	if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR) {
1248 		/* no source address assigned yet */
1249 		ret = -EBADFD;
1250 		goto sendmsg_done;
1251 	}
1252 
1253 	/* deal with provided destination address info */
1254 	if (msg->msg_name) {
1255 		struct sockaddr_can *addr = msg->msg_name;
1256 
1257 		if (msg->msg_namelen < J1939_MIN_NAMELEN) {
1258 			ret = -EINVAL;
1259 			goto sendmsg_done;
1260 		}
1261 
1262 		if (addr->can_family != AF_CAN) {
1263 			ret = -EINVAL;
1264 			goto sendmsg_done;
1265 		}
1266 
1267 		if (addr->can_ifindex && addr->can_ifindex != ifindex) {
1268 			ret = -EBADFD;
1269 			goto sendmsg_done;
1270 		}
1271 
1272 		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
1273 		    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn)) {
1274 			ret = -EINVAL;
1275 			goto sendmsg_done;
1276 		}
1277 
1278 		if (!addr->can_addr.j1939.name &&
1279 		    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
1280 		    !sock_flag(sk, SOCK_BROADCAST)) {
1281 			/* broadcast, but SO_BROADCAST not set */
1282 			ret = -EACCES;
1283 			goto sendmsg_done;
1284 		}
1285 	} else {
1286 		if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
1287 		    !sock_flag(sk, SOCK_BROADCAST)) {
1288 			/* broadcast, but SO_BROADCAST not set */
1289 			ret = -EACCES;
1290 			goto sendmsg_done;
1291 		}
1292 	}
1293 
1294 	ret = j1939_sk_send_loop(priv, sk, msg, size);
1295 
1296 sendmsg_done:
1297 	release_sock(sock->sk);
1298 
1299 	return ret;
1300 }
1301 
1302 void j1939_sk_netdev_event_netdown(struct j1939_priv *priv)
1303 {
1304 	struct j1939_sock *jsk;
1305 	int error_code = ENETDOWN;
1306 
1307 	read_lock_bh(&priv->j1939_socks_lock);
1308 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
1309 		jsk->sk.sk_err = error_code;
1310 		if (!sock_flag(&jsk->sk, SOCK_DEAD))
1311 			sk_error_report(&jsk->sk);
1312 
1313 		j1939_sk_queue_drop_all(priv, jsk, error_code);
1314 	}
1315 	read_unlock_bh(&priv->j1939_socks_lock);
1316 }
1317 
1318 void j1939_sk_netdev_event_unregister(struct j1939_priv *priv)
1319 {
1320 	struct sock *sk;
1321 	struct j1939_sock *jsk;
1322 	bool wait_rcu = false;
1323 
1324 rescan: /* The caller is holding a ref on this "priv" via j1939_priv_get_by_ndev(). */
1325 	read_lock_bh(&priv->j1939_socks_lock);
1326 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
1327 		/* Skip if j1939_jsk_add() is not called on this socket. */
1328 		if (!(jsk->state & J1939_SOCK_BOUND))
1329 			continue;
1330 		sk = &jsk->sk;
1331 		sock_hold(sk);
1332 		read_unlock_bh(&priv->j1939_socks_lock);
1333 		/* Check if j1939_jsk_del() is not yet called on this socket after holding
1334 		 * socket's lock, for both j1939_sk_bind() and j1939_sk_release() call
1335 		 * j1939_jsk_del() with socket's lock held.
1336 		 */
1337 		lock_sock(sk);
1338 		if (jsk->state & J1939_SOCK_BOUND) {
1339 			/* Neither j1939_sk_bind() nor j1939_sk_release() called j1939_jsk_del().
1340 			 * Make this socket no longer bound, by pretending as if j1939_sk_bind()
1341 			 * dropped old references but did not get new references.
1342 			 */
1343 			j1939_jsk_del(priv, jsk);
1344 			j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
1345 			j1939_netdev_stop(priv);
1346 			/* Call j1939_priv_put() now and prevent j1939_sk_sock_destruct() from
1347 			 * calling the corresponding j1939_priv_put().
1348 			 *
1349 			 * j1939_sk_sock_destruct() is supposed to call j1939_priv_put() after
1350 			 * an RCU grace period. But since the caller is holding a ref on this
1351 			 * "priv", we can defer synchronize_rcu() until immediately before
1352 			 * the caller calls j1939_priv_put().
1353 			 */
1354 			j1939_priv_put(priv);
1355 			jsk->priv = NULL;
1356 			wait_rcu = true;
1357 		}
1358 		release_sock(sk);
1359 		sock_put(sk);
1360 		goto rescan;
1361 	}
1362 	read_unlock_bh(&priv->j1939_socks_lock);
1363 	if (wait_rcu)
1364 		synchronize_rcu();
1365 }
1366 
1367 static int j1939_sk_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1368 				unsigned long arg)
1369 {
1370 	/* no ioctls for socket layer -> hand it down to NIC layer */
1371 	return -ENOIOCTLCMD;
1372 }
1373 
1374 static const struct proto_ops j1939_ops = {
1375 	.family = PF_CAN,
1376 	.release = j1939_sk_release,
1377 	.bind = j1939_sk_bind,
1378 	.connect = j1939_sk_connect,
1379 	.socketpair = sock_no_socketpair,
1380 	.accept = sock_no_accept,
1381 	.getname = j1939_sk_getname,
1382 	.poll = datagram_poll,
1383 	.ioctl = j1939_sk_no_ioctlcmd,
1384 	.listen = sock_no_listen,
1385 	.shutdown = sock_no_shutdown,
1386 	.setsockopt = j1939_sk_setsockopt,
1387 	.getsockopt = j1939_sk_getsockopt,
1388 	.sendmsg = j1939_sk_sendmsg,
1389 	.recvmsg = j1939_sk_recvmsg,
1390 	.mmap = sock_no_mmap,
1391 };
1392 
1393 static struct proto j1939_proto __read_mostly = {
1394 	.name = "CAN_J1939",
1395 	.owner = THIS_MODULE,
1396 	.obj_size = sizeof(struct j1939_sock),
1397 	.init = j1939_sk_init,
1398 };
1399 
1400 const struct can_proto j1939_can_proto = {
1401 	.type = SOCK_DGRAM,
1402 	.protocol = CAN_J1939,
1403 	.ops = &j1939_ops,
1404 	.prot = &j1939_proto,
1405 };
1406