xref: /openbmc/linux/net/can/j1939/socket.c (revision 8e20ba2e) 
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 	jsk->priv = priv;
82 
83 	spin_lock_bh(&priv->j1939_socks_lock);
84 	list_add_tail(&jsk->list, &priv->j1939_socks);
85 	spin_unlock_bh(&priv->j1939_socks_lock);
86 }
87 
88 static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
89 {
90 	spin_lock_bh(&priv->j1939_socks_lock);
91 	list_del_init(&jsk->list);
92 	spin_unlock_bh(&priv->j1939_socks_lock);
93 
94 	jsk->priv = NULL;
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 (WARN_ON_ONCE(j1939_session_activate(first))) {
183 		first->err = -EBUSY;
184 		goto activate_next;
185 	} else {
186 		/* Give receiver some time (arbitrary chosen) to recover */
187 		int time_ms = 0;
188 
189 		if (err)
190 			time_ms = 10 + prandom_u32_max(16);
191 
192 		j1939_tp_schedule_txtimer(first, time_ms);
193 	}
194 }
195 
196 void j1939_sk_queue_activate_next(struct j1939_session *session)
197 {
198 	struct j1939_sock *jsk;
199 
200 	if (!session->sk)
201 		return;
202 
203 	jsk = j1939_sk(session->sk);
204 
205 	spin_lock_bh(&jsk->sk_session_queue_lock);
206 	j1939_sk_queue_activate_next_locked(session);
207 	spin_unlock_bh(&jsk->sk_session_queue_lock);
208 }
209 
210 static bool j1939_sk_match_dst(struct j1939_sock *jsk,
211 			       const struct j1939_sk_buff_cb *skcb)
212 {
213 	if ((jsk->state & J1939_SOCK_PROMISC))
214 		return true;
215 
216 	/* Destination address filter */
217 	if (jsk->addr.src_name && skcb->addr.dst_name) {
218 		if (jsk->addr.src_name != skcb->addr.dst_name)
219 			return false;
220 	} else {
221 		/* receive (all sockets) if
222 		 * - all packages that match our bind() address
223 		 * - all broadcast on a socket if SO_BROADCAST
224 		 *   is set
225 		 */
226 		if (j1939_address_is_unicast(skcb->addr.da)) {
227 			if (jsk->addr.sa != skcb->addr.da)
228 				return false;
229 		} else if (!sock_flag(&jsk->sk, SOCK_BROADCAST)) {
230 			/* receiving broadcast without SO_BROADCAST
231 			 * flag is not allowed
232 			 */
233 			return false;
234 		}
235 	}
236 
237 	/* Source address filter */
238 	if (jsk->state & J1939_SOCK_CONNECTED) {
239 		/* receive (all sockets) if
240 		 * - all packages that match our connect() name or address
241 		 */
242 		if (jsk->addr.dst_name && skcb->addr.src_name) {
243 			if (jsk->addr.dst_name != skcb->addr.src_name)
244 				return false;
245 		} else {
246 			if (jsk->addr.da != skcb->addr.sa)
247 				return false;
248 		}
249 	}
250 
251 	/* PGN filter */
252 	if (j1939_pgn_is_valid(jsk->pgn_rx_filter) &&
253 	    jsk->pgn_rx_filter != skcb->addr.pgn)
254 		return false;
255 
256 	return true;
257 }
258 
259 /* matches skb control buffer (addr) with a j1939 filter */
260 static bool j1939_sk_match_filter(struct j1939_sock *jsk,
261 				  const struct j1939_sk_buff_cb *skcb)
262 {
263 	const struct j1939_filter *f = jsk->filters;
264 	int nfilter = jsk->nfilters;
265 
266 	if (!nfilter)
267 		/* receive all when no filters are assigned */
268 		return true;
269 
270 	for (; nfilter; ++f, --nfilter) {
271 		if ((skcb->addr.pgn & f->pgn_mask) != f->pgn)
272 			continue;
273 		if ((skcb->addr.sa & f->addr_mask) != f->addr)
274 			continue;
275 		if ((skcb->addr.src_name & f->name_mask) != f->name)
276 			continue;
277 		return true;
278 	}
279 	return false;
280 }
281 
282 static bool j1939_sk_recv_match_one(struct j1939_sock *jsk,
283 				    const struct j1939_sk_buff_cb *skcb)
284 {
285 	if (!(jsk->state & J1939_SOCK_BOUND))
286 		return false;
287 
288 	if (!j1939_sk_match_dst(jsk, skcb))
289 		return false;
290 
291 	if (!j1939_sk_match_filter(jsk, skcb))
292 		return false;
293 
294 	return true;
295 }
296 
297 static void j1939_sk_recv_one(struct j1939_sock *jsk, struct sk_buff *oskb)
298 {
299 	const struct j1939_sk_buff_cb *oskcb = j1939_skb_to_cb(oskb);
300 	struct j1939_sk_buff_cb *skcb;
301 	struct sk_buff *skb;
302 
303 	if (oskb->sk == &jsk->sk)
304 		return;
305 
306 	if (!j1939_sk_recv_match_one(jsk, oskcb))
307 		return;
308 
309 	skb = skb_clone(oskb, GFP_ATOMIC);
310 	if (!skb) {
311 		pr_warn("skb clone failed\n");
312 		return;
313 	}
314 	can_skb_set_owner(skb, oskb->sk);
315 
316 	skcb = j1939_skb_to_cb(skb);
317 	skcb->msg_flags &= ~(MSG_DONTROUTE);
318 	if (skb->sk)
319 		skcb->msg_flags |= MSG_DONTROUTE;
320 
321 	if (sock_queue_rcv_skb(&jsk->sk, skb) < 0)
322 		kfree_skb(skb);
323 }
324 
325 bool j1939_sk_recv_match(struct j1939_priv *priv, struct j1939_sk_buff_cb *skcb)
326 {
327 	struct j1939_sock *jsk;
328 	bool match = false;
329 
330 	spin_lock_bh(&priv->j1939_socks_lock);
331 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
332 		match = j1939_sk_recv_match_one(jsk, skcb);
333 		if (match)
334 			break;
335 	}
336 	spin_unlock_bh(&priv->j1939_socks_lock);
337 
338 	return match;
339 }
340 
341 void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb)
342 {
343 	struct j1939_sock *jsk;
344 
345 	spin_lock_bh(&priv->j1939_socks_lock);
346 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
347 		j1939_sk_recv_one(jsk, skb);
348 	}
349 	spin_unlock_bh(&priv->j1939_socks_lock);
350 }
351 
352 static int j1939_sk_init(struct sock *sk)
353 {
354 	struct j1939_sock *jsk = j1939_sk(sk);
355 
356 	/* Ensure that "sk" is first member in "struct j1939_sock", so that we
357 	 * can skip it during memset().
358 	 */
359 	BUILD_BUG_ON(offsetof(struct j1939_sock, sk) != 0);
360 	memset((void *)jsk + sizeof(jsk->sk), 0x0,
361 	       sizeof(*jsk) - sizeof(jsk->sk));
362 
363 	INIT_LIST_HEAD(&jsk->list);
364 	init_waitqueue_head(&jsk->waitq);
365 	jsk->sk.sk_priority = j1939_to_sk_priority(6);
366 	jsk->sk.sk_reuse = 1; /* per default */
367 	jsk->addr.sa = J1939_NO_ADDR;
368 	jsk->addr.da = J1939_NO_ADDR;
369 	jsk->addr.pgn = J1939_NO_PGN;
370 	jsk->pgn_rx_filter = J1939_NO_PGN;
371 	atomic_set(&jsk->skb_pending, 0);
372 	spin_lock_init(&jsk->sk_session_queue_lock);
373 	INIT_LIST_HEAD(&jsk->sk_session_queue);
374 
375 	return 0;
376 }
377 
378 static int j1939_sk_sanity_check(struct sockaddr_can *addr, int len)
379 {
380 	if (!addr)
381 		return -EDESTADDRREQ;
382 	if (len < J1939_MIN_NAMELEN)
383 		return -EINVAL;
384 	if (addr->can_family != AF_CAN)
385 		return -EINVAL;
386 	if (!addr->can_ifindex)
387 		return -ENODEV;
388 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
389 	    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
390 		return -EINVAL;
391 
392 	return 0;
393 }
394 
395 static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
396 {
397 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
398 	struct j1939_sock *jsk = j1939_sk(sock->sk);
399 	struct j1939_priv *priv = jsk->priv;
400 	struct sock *sk = sock->sk;
401 	struct net *net = sock_net(sk);
402 	int ret = 0;
403 
404 	ret = j1939_sk_sanity_check(addr, len);
405 	if (ret)
406 		return ret;
407 
408 	lock_sock(sock->sk);
409 
410 	/* Already bound to an interface? */
411 	if (jsk->state & J1939_SOCK_BOUND) {
412 		/* A re-bind() to a different interface is not
413 		 * supported.
414 		 */
415 		if (jsk->ifindex != addr->can_ifindex) {
416 			ret = -EINVAL;
417 			goto out_release_sock;
418 		}
419 
420 		/* drop old references */
421 		j1939_jsk_del(priv, jsk);
422 		j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
423 	} else {
424 		struct net_device *ndev;
425 
426 		ndev = dev_get_by_index(net, addr->can_ifindex);
427 		if (!ndev) {
428 			ret = -ENODEV;
429 			goto out_release_sock;
430 		}
431 
432 		if (ndev->type != ARPHRD_CAN) {
433 			dev_put(ndev);
434 			ret = -ENODEV;
435 			goto out_release_sock;
436 		}
437 
438 		priv = j1939_netdev_start(ndev);
439 		dev_put(ndev);
440 		if (IS_ERR(priv)) {
441 			ret = PTR_ERR(priv);
442 			goto out_release_sock;
443 		}
444 
445 		jsk->ifindex = addr->can_ifindex;
446 	}
447 
448 	/* set default transmit pgn */
449 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
450 		jsk->pgn_rx_filter = addr->can_addr.j1939.pgn;
451 	jsk->addr.src_name = addr->can_addr.j1939.name;
452 	jsk->addr.sa = addr->can_addr.j1939.addr;
453 
454 	/* get new references */
455 	ret = j1939_local_ecu_get(priv, jsk->addr.src_name, jsk->addr.sa);
456 	if (ret) {
457 		j1939_netdev_stop(priv);
458 		goto out_release_sock;
459 	}
460 
461 	j1939_jsk_add(priv, jsk);
462 
463  out_release_sock: /* fall through */
464 	release_sock(sock->sk);
465 
466 	return ret;
467 }
468 
469 static int j1939_sk_connect(struct socket *sock, struct sockaddr *uaddr,
470 			    int len, int flags)
471 {
472 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
473 	struct j1939_sock *jsk = j1939_sk(sock->sk);
474 	int ret = 0;
475 
476 	ret = j1939_sk_sanity_check(addr, len);
477 	if (ret)
478 		return ret;
479 
480 	lock_sock(sock->sk);
481 
482 	/* bind() before connect() is mandatory */
483 	if (!(jsk->state & J1939_SOCK_BOUND)) {
484 		ret = -EINVAL;
485 		goto out_release_sock;
486 	}
487 
488 	/* A connect() to a different interface is not supported. */
489 	if (jsk->ifindex != addr->can_ifindex) {
490 		ret = -EINVAL;
491 		goto out_release_sock;
492 	}
493 
494 	if (!addr->can_addr.j1939.name &&
495 	    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
496 	    !sock_flag(&jsk->sk, SOCK_BROADCAST)) {
497 		/* broadcast, but SO_BROADCAST not set */
498 		ret = -EACCES;
499 		goto out_release_sock;
500 	}
501 
502 	jsk->addr.dst_name = addr->can_addr.j1939.name;
503 	jsk->addr.da = addr->can_addr.j1939.addr;
504 
505 	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
506 		jsk->addr.pgn = addr->can_addr.j1939.pgn;
507 
508 	jsk->state |= J1939_SOCK_CONNECTED;
509 
510  out_release_sock: /* fall through */
511 	release_sock(sock->sk);
512 
513 	return ret;
514 }
515 
516 static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr,
517 				       const struct j1939_sock *jsk, int peer)
518 {
519 	addr->can_family = AF_CAN;
520 	addr->can_ifindex = jsk->ifindex;
521 	addr->can_addr.j1939.pgn = jsk->addr.pgn;
522 	if (peer) {
523 		addr->can_addr.j1939.name = jsk->addr.dst_name;
524 		addr->can_addr.j1939.addr = jsk->addr.da;
525 	} else {
526 		addr->can_addr.j1939.name = jsk->addr.src_name;
527 		addr->can_addr.j1939.addr = jsk->addr.sa;
528 	}
529 }
530 
531 static int j1939_sk_getname(struct socket *sock, struct sockaddr *uaddr,
532 			    int peer)
533 {
534 	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
535 	struct sock *sk = sock->sk;
536 	struct j1939_sock *jsk = j1939_sk(sk);
537 	int ret = 0;
538 
539 	lock_sock(sk);
540 
541 	if (peer && !(jsk->state & J1939_SOCK_CONNECTED)) {
542 		ret = -EADDRNOTAVAIL;
543 		goto failure;
544 	}
545 
546 	j1939_sk_sock2sockaddr_can(addr, jsk, peer);
547 	ret = J1939_MIN_NAMELEN;
548 
549  failure:
550 	release_sock(sk);
551 
552 	return ret;
553 }
554 
555 static int j1939_sk_release(struct socket *sock)
556 {
557 	struct sock *sk = sock->sk;
558 	struct j1939_sock *jsk;
559 
560 	if (!sk)
561 		return 0;
562 
563 	jsk = j1939_sk(sk);
564 	lock_sock(sk);
565 
566 	if (jsk->state & J1939_SOCK_BOUND) {
567 		struct j1939_priv *priv = jsk->priv;
568 
569 		if (wait_event_interruptible(jsk->waitq,
570 					     !j1939_sock_pending_get(&jsk->sk))) {
571 			j1939_cancel_active_session(priv, sk);
572 			j1939_sk_queue_drop_all(priv, jsk, ESHUTDOWN);
573 		}
574 
575 		j1939_jsk_del(priv, jsk);
576 
577 		j1939_local_ecu_put(priv, jsk->addr.src_name,
578 				    jsk->addr.sa);
579 
580 		j1939_netdev_stop(priv);
581 	}
582 
583 	kfree(jsk->filters);
584 	sock_orphan(sk);
585 	sock->sk = NULL;
586 
587 	release_sock(sk);
588 	sock_put(sk);
589 
590 	return 0;
591 }
592 
593 static int j1939_sk_setsockopt_flag(struct j1939_sock *jsk, char __user *optval,
594 				    unsigned int optlen, int flag)
595 {
596 	int tmp;
597 
598 	if (optlen != sizeof(tmp))
599 		return -EINVAL;
600 	if (copy_from_user(&tmp, optval, optlen))
601 		return -EFAULT;
602 	lock_sock(&jsk->sk);
603 	if (tmp)
604 		jsk->state |= flag;
605 	else
606 		jsk->state &= ~flag;
607 	release_sock(&jsk->sk);
608 	return tmp;
609 }
610 
611 static int j1939_sk_setsockopt(struct socket *sock, int level, int optname,
612 			       char __user *optval, unsigned int optlen)
613 {
614 	struct sock *sk = sock->sk;
615 	struct j1939_sock *jsk = j1939_sk(sk);
616 	int tmp, count = 0, ret = 0;
617 	struct j1939_filter *filters = NULL, *ofilters;
618 
619 	if (level != SOL_CAN_J1939)
620 		return -EINVAL;
621 
622 	switch (optname) {
623 	case SO_J1939_FILTER:
624 		if (optval) {
625 			struct j1939_filter *f;
626 			int c;
627 
628 			if (optlen % sizeof(*filters) != 0)
629 				return -EINVAL;
630 
631 			if (optlen > J1939_FILTER_MAX *
632 			    sizeof(struct j1939_filter))
633 				return -EINVAL;
634 
635 			count = optlen / sizeof(*filters);
636 			filters = memdup_user(optval, optlen);
637 			if (IS_ERR(filters))
638 				return PTR_ERR(filters);
639 
640 			for (f = filters, c = count; c; f++, c--) {
641 				f->name &= f->name_mask;
642 				f->pgn &= f->pgn_mask;
643 				f->addr &= f->addr_mask;
644 			}
645 		}
646 
647 		lock_sock(&jsk->sk);
648 		ofilters = jsk->filters;
649 		jsk->filters = filters;
650 		jsk->nfilters = count;
651 		release_sock(&jsk->sk);
652 		kfree(ofilters);
653 		return 0;
654 	case SO_J1939_PROMISC:
655 		return j1939_sk_setsockopt_flag(jsk, optval, optlen,
656 						J1939_SOCK_PROMISC);
657 	case SO_J1939_ERRQUEUE:
658 		ret = j1939_sk_setsockopt_flag(jsk, optval, optlen,
659 					       J1939_SOCK_ERRQUEUE);
660 		if (ret < 0)
661 			return ret;
662 
663 		if (!(jsk->state & J1939_SOCK_ERRQUEUE))
664 			skb_queue_purge(&sk->sk_error_queue);
665 		return ret;
666 	case SO_J1939_SEND_PRIO:
667 		if (optlen != sizeof(tmp))
668 			return -EINVAL;
669 		if (copy_from_user(&tmp, optval, optlen))
670 			return -EFAULT;
671 		if (tmp < 0 || tmp > 7)
672 			return -EDOM;
673 		if (tmp < 2 && !capable(CAP_NET_ADMIN))
674 			return -EPERM;
675 		lock_sock(&jsk->sk);
676 		jsk->sk.sk_priority = j1939_to_sk_priority(tmp);
677 		release_sock(&jsk->sk);
678 		return 0;
679 	default:
680 		return -ENOPROTOOPT;
681 	}
682 }
683 
684 static int j1939_sk_getsockopt(struct socket *sock, int level, int optname,
685 			       char __user *optval, int __user *optlen)
686 {
687 	struct sock *sk = sock->sk;
688 	struct j1939_sock *jsk = j1939_sk(sk);
689 	int ret, ulen;
690 	/* set defaults for using 'int' properties */
691 	int tmp = 0;
692 	int len = sizeof(tmp);
693 	void *val = &tmp;
694 
695 	if (level != SOL_CAN_J1939)
696 		return -EINVAL;
697 	if (get_user(ulen, optlen))
698 		return -EFAULT;
699 	if (ulen < 0)
700 		return -EINVAL;
701 
702 	lock_sock(&jsk->sk);
703 	switch (optname) {
704 	case SO_J1939_PROMISC:
705 		tmp = (jsk->state & J1939_SOCK_PROMISC) ? 1 : 0;
706 		break;
707 	case SO_J1939_ERRQUEUE:
708 		tmp = (jsk->state & J1939_SOCK_ERRQUEUE) ? 1 : 0;
709 		break;
710 	case SO_J1939_SEND_PRIO:
711 		tmp = j1939_prio(jsk->sk.sk_priority);
712 		break;
713 	default:
714 		ret = -ENOPROTOOPT;
715 		goto no_copy;
716 	}
717 
718 	/* copy to user, based on 'len' & 'val'
719 	 * but most sockopt's are 'int' properties, and have 'len' & 'val'
720 	 * left unchanged, but instead modified 'tmp'
721 	 */
722 	if (len > ulen)
723 		ret = -EFAULT;
724 	else if (put_user(len, optlen))
725 		ret = -EFAULT;
726 	else if (copy_to_user(optval, val, len))
727 		ret = -EFAULT;
728 	else
729 		ret = 0;
730  no_copy:
731 	release_sock(&jsk->sk);
732 	return ret;
733 }
734 
735 static int j1939_sk_recvmsg(struct socket *sock, struct msghdr *msg,
736 			    size_t size, int flags)
737 {
738 	struct sock *sk = sock->sk;
739 	struct sk_buff *skb;
740 	struct j1939_sk_buff_cb *skcb;
741 	int ret = 0;
742 
743 	if (flags & ~(MSG_DONTWAIT | MSG_ERRQUEUE))
744 		return -EINVAL;
745 
746 	if (flags & MSG_ERRQUEUE)
747 		return sock_recv_errqueue(sock->sk, msg, size, SOL_CAN_J1939,
748 					  SCM_J1939_ERRQUEUE);
749 
750 	skb = skb_recv_datagram(sk, flags, 0, &ret);
751 	if (!skb)
752 		return ret;
753 
754 	if (size < skb->len)
755 		msg->msg_flags |= MSG_TRUNC;
756 	else
757 		size = skb->len;
758 
759 	ret = memcpy_to_msg(msg, skb->data, size);
760 	if (ret < 0) {
761 		skb_free_datagram(sk, skb);
762 		return ret;
763 	}
764 
765 	skcb = j1939_skb_to_cb(skb);
766 	if (j1939_address_is_valid(skcb->addr.da))
767 		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_ADDR,
768 			 sizeof(skcb->addr.da), &skcb->addr.da);
769 
770 	if (skcb->addr.dst_name)
771 		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_NAME,
772 			 sizeof(skcb->addr.dst_name), &skcb->addr.dst_name);
773 
774 	put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_PRIO,
775 		 sizeof(skcb->priority), &skcb->priority);
776 
777 	if (msg->msg_name) {
778 		struct sockaddr_can *paddr = msg->msg_name;
779 
780 		msg->msg_namelen = J1939_MIN_NAMELEN;
781 		memset(msg->msg_name, 0, msg->msg_namelen);
782 		paddr->can_family = AF_CAN;
783 		paddr->can_ifindex = skb->skb_iif;
784 		paddr->can_addr.j1939.name = skcb->addr.src_name;
785 		paddr->can_addr.j1939.addr = skcb->addr.sa;
786 		paddr->can_addr.j1939.pgn = skcb->addr.pgn;
787 	}
788 
789 	sock_recv_ts_and_drops(msg, sk, skb);
790 	msg->msg_flags |= skcb->msg_flags;
791 	skb_free_datagram(sk, skb);
792 
793 	return size;
794 }
795 
796 static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
797 					  struct sock *sk,
798 					  struct msghdr *msg, size_t size,
799 					  int *errcode)
800 {
801 	struct j1939_sock *jsk = j1939_sk(sk);
802 	struct j1939_sk_buff_cb *skcb;
803 	struct sk_buff *skb;
804 	int ret;
805 
806 	skb = sock_alloc_send_skb(sk,
807 				  size +
808 				  sizeof(struct can_frame) -
809 				  sizeof(((struct can_frame *)NULL)->data) +
810 				  sizeof(struct can_skb_priv),
811 				  msg->msg_flags & MSG_DONTWAIT, &ret);
812 	if (!skb)
813 		goto failure;
814 
815 	can_skb_reserve(skb);
816 	can_skb_prv(skb)->ifindex = ndev->ifindex;
817 	can_skb_prv(skb)->skbcnt = 0;
818 	skb_reserve(skb, offsetof(struct can_frame, data));
819 
820 	ret = memcpy_from_msg(skb_put(skb, size), msg, size);
821 	if (ret < 0)
822 		goto free_skb;
823 
824 	skb->dev = ndev;
825 
826 	skcb = j1939_skb_to_cb(skb);
827 	memset(skcb, 0, sizeof(*skcb));
828 	skcb->addr = jsk->addr;
829 	skcb->priority = j1939_prio(sk->sk_priority);
830 
831 	if (msg->msg_name) {
832 		struct sockaddr_can *addr = msg->msg_name;
833 
834 		if (addr->can_addr.j1939.name ||
835 		    addr->can_addr.j1939.addr != J1939_NO_ADDR) {
836 			skcb->addr.dst_name = addr->can_addr.j1939.name;
837 			skcb->addr.da = addr->can_addr.j1939.addr;
838 		}
839 		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
840 			skcb->addr.pgn = addr->can_addr.j1939.pgn;
841 	}
842 
843 	*errcode = ret;
844 	return skb;
845 
846 free_skb:
847 	kfree_skb(skb);
848 failure:
849 	*errcode = ret;
850 	return NULL;
851 }
852 
853 static size_t j1939_sk_opt_stats_get_size(void)
854 {
855 	return
856 		nla_total_size(sizeof(u32)) + /* J1939_NLA_BYTES_ACKED */
857 		0;
858 }
859 
860 static struct sk_buff *
861 j1939_sk_get_timestamping_opt_stats(struct j1939_session *session)
862 {
863 	struct sk_buff *stats;
864 	u32 size;
865 
866 	stats = alloc_skb(j1939_sk_opt_stats_get_size(), GFP_ATOMIC);
867 	if (!stats)
868 		return NULL;
869 
870 	if (session->skcb.addr.type == J1939_SIMPLE)
871 		size = session->total_message_size;
872 	else
873 		size = min(session->pkt.tx_acked * 7,
874 			   session->total_message_size);
875 
876 	nla_put_u32(stats, J1939_NLA_BYTES_ACKED, size);
877 
878 	return stats;
879 }
880 
881 void j1939_sk_errqueue(struct j1939_session *session,
882 		       enum j1939_sk_errqueue_type type)
883 {
884 	struct j1939_priv *priv = session->priv;
885 	struct sock *sk = session->sk;
886 	struct j1939_sock *jsk;
887 	struct sock_exterr_skb *serr;
888 	struct sk_buff *skb;
889 	char *state = "UNK";
890 	int err;
891 
892 	/* currently we have no sk for the RX session */
893 	if (!sk)
894 		return;
895 
896 	jsk = j1939_sk(sk);
897 
898 	if (!(jsk->state & J1939_SOCK_ERRQUEUE))
899 		return;
900 
901 	skb = j1939_sk_get_timestamping_opt_stats(session);
902 	if (!skb)
903 		return;
904 
905 	skb->tstamp = ktime_get_real();
906 
907 	BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb));
908 
909 	serr = SKB_EXT_ERR(skb);
910 	memset(serr, 0, sizeof(*serr));
911 	switch (type) {
912 	case J1939_ERRQUEUE_ACK:
913 		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_ACK)) {
914 			kfree_skb(skb);
915 			return;
916 		}
917 
918 		serr->ee.ee_errno = ENOMSG;
919 		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
920 		serr->ee.ee_info = SCM_TSTAMP_ACK;
921 		state = "ACK";
922 		break;
923 	case J1939_ERRQUEUE_SCHED:
924 		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED)) {
925 			kfree_skb(skb);
926 			return;
927 		}
928 
929 		serr->ee.ee_errno = ENOMSG;
930 		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
931 		serr->ee.ee_info = SCM_TSTAMP_SCHED;
932 		state = "SCH";
933 		break;
934 	case J1939_ERRQUEUE_ABORT:
935 		serr->ee.ee_errno = session->err;
936 		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
937 		serr->ee.ee_info = J1939_EE_INFO_TX_ABORT;
938 		state = "ABT";
939 		break;
940 	default:
941 		netdev_err(priv->ndev, "Unknown errqueue type %i\n", type);
942 	}
943 
944 	serr->opt_stats = true;
945 	if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
946 		serr->ee.ee_data = session->tskey;
947 
948 	netdev_dbg(session->priv->ndev, "%s: 0x%p tskey: %i, state: %s\n",
949 		   __func__, session, session->tskey, state);
950 	err = sock_queue_err_skb(sk, skb);
951 
952 	if (err)
953 		kfree_skb(skb);
954 };
955 
956 void j1939_sk_send_loop_abort(struct sock *sk, int err)
957 {
958 	sk->sk_err = err;
959 
960 	sk->sk_error_report(sk);
961 }
962 
963 static int j1939_sk_send_loop(struct j1939_priv *priv,  struct sock *sk,
964 			      struct msghdr *msg, size_t size)
965 
966 {
967 	struct j1939_sock *jsk = j1939_sk(sk);
968 	struct j1939_session *session = j1939_sk_get_incomplete_session(jsk);
969 	struct sk_buff *skb;
970 	size_t segment_size, todo_size;
971 	int ret = 0;
972 
973 	if (session &&
974 	    session->total_message_size != session->total_queued_size + size) {
975 		j1939_session_put(session);
976 		return -EIO;
977 	}
978 
979 	todo_size = size;
980 
981 	while (todo_size) {
982 		struct j1939_sk_buff_cb *skcb;
983 
984 		segment_size = min_t(size_t, J1939_MAX_TP_PACKET_SIZE,
985 				     todo_size);
986 
987 		/* Allocate skb for one segment */
988 		skb = j1939_sk_alloc_skb(priv->ndev, sk, msg, segment_size,
989 					 &ret);
990 		if (ret)
991 			break;
992 
993 		skcb = j1939_skb_to_cb(skb);
994 
995 		if (!session) {
996 			/* at this point the size should be full size
997 			 * of the session
998 			 */
999 			skcb->offset = 0;
1000 			session = j1939_tp_send(priv, skb, size);
1001 			if (IS_ERR(session)) {
1002 				ret = PTR_ERR(session);
1003 				goto kfree_skb;
1004 			}
1005 			if (j1939_sk_queue_session(session)) {
1006 				/* try to activate session if we a
1007 				 * fist in the queue
1008 				 */
1009 				if (!j1939_session_activate(session)) {
1010 					j1939_tp_schedule_txtimer(session, 0);
1011 				} else {
1012 					ret = -EBUSY;
1013 					session->err = ret;
1014 					j1939_sk_queue_drop_all(priv, jsk,
1015 								EBUSY);
1016 					break;
1017 				}
1018 			}
1019 		} else {
1020 			skcb->offset = session->total_queued_size;
1021 			j1939_session_skb_queue(session, skb);
1022 		}
1023 
1024 		todo_size -= segment_size;
1025 		session->total_queued_size += segment_size;
1026 	}
1027 
1028 	switch (ret) {
1029 	case 0: /* OK */
1030 		if (todo_size)
1031 			netdev_warn(priv->ndev,
1032 				    "no error found and not completely queued?! %zu\n",
1033 				    todo_size);
1034 		ret = size;
1035 		break;
1036 	case -ERESTARTSYS:
1037 		ret = -EINTR;
1038 		/* fall through */
1039 	case -EAGAIN: /* OK */
1040 		if (todo_size != size)
1041 			ret = size - todo_size;
1042 		break;
1043 	default: /* ERROR */
1044 		break;
1045 	}
1046 
1047 	if (session)
1048 		j1939_session_put(session);
1049 
1050 	return ret;
1051 
1052  kfree_skb:
1053 	kfree_skb(skb);
1054 	return ret;
1055 }
1056 
1057 static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
1058 			    size_t size)
1059 {
1060 	struct sock *sk = sock->sk;
1061 	struct j1939_sock *jsk = j1939_sk(sk);
1062 	struct j1939_priv *priv = jsk->priv;
1063 	int ifindex;
1064 	int ret;
1065 
1066 	/* various socket state tests */
1067 	if (!(jsk->state & J1939_SOCK_BOUND))
1068 		return -EBADFD;
1069 
1070 	ifindex = jsk->ifindex;
1071 
1072 	if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR)
1073 		/* no source address assigned yet */
1074 		return -EBADFD;
1075 
1076 	/* deal with provided destination address info */
1077 	if (msg->msg_name) {
1078 		struct sockaddr_can *addr = msg->msg_name;
1079 
1080 		if (msg->msg_namelen < J1939_MIN_NAMELEN)
1081 			return -EINVAL;
1082 
1083 		if (addr->can_family != AF_CAN)
1084 			return -EINVAL;
1085 
1086 		if (addr->can_ifindex && addr->can_ifindex != ifindex)
1087 			return -EBADFD;
1088 
1089 		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
1090 		    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
1091 			return -EINVAL;
1092 
1093 		if (!addr->can_addr.j1939.name &&
1094 		    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
1095 		    !sock_flag(sk, SOCK_BROADCAST))
1096 			/* broadcast, but SO_BROADCAST not set */
1097 			return -EACCES;
1098 	} else {
1099 		if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
1100 		    !sock_flag(sk, SOCK_BROADCAST))
1101 			/* broadcast, but SO_BROADCAST not set */
1102 			return -EACCES;
1103 	}
1104 
1105 	ret = j1939_sk_send_loop(priv, sk, msg, size);
1106 
1107 	return ret;
1108 }
1109 
1110 void j1939_sk_netdev_event_netdown(struct j1939_priv *priv)
1111 {
1112 	struct j1939_sock *jsk;
1113 	int error_code = ENETDOWN;
1114 
1115 	spin_lock_bh(&priv->j1939_socks_lock);
1116 	list_for_each_entry(jsk, &priv->j1939_socks, list) {
1117 		jsk->sk.sk_err = error_code;
1118 		if (!sock_flag(&jsk->sk, SOCK_DEAD))
1119 			jsk->sk.sk_error_report(&jsk->sk);
1120 
1121 		j1939_sk_queue_drop_all(priv, jsk, error_code);
1122 	}
1123 	spin_unlock_bh(&priv->j1939_socks_lock);
1124 }
1125 
1126 static int j1939_sk_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1127 				unsigned long arg)
1128 {
1129 	/* no ioctls for socket layer -> hand it down to NIC layer */
1130 	return -ENOIOCTLCMD;
1131 }
1132 
1133 static const struct proto_ops j1939_ops = {
1134 	.family = PF_CAN,
1135 	.release = j1939_sk_release,
1136 	.bind = j1939_sk_bind,
1137 	.connect = j1939_sk_connect,
1138 	.socketpair = sock_no_socketpair,
1139 	.accept = sock_no_accept,
1140 	.getname = j1939_sk_getname,
1141 	.poll = datagram_poll,
1142 	.ioctl = j1939_sk_no_ioctlcmd,
1143 	.listen = sock_no_listen,
1144 	.shutdown = sock_no_shutdown,
1145 	.setsockopt = j1939_sk_setsockopt,
1146 	.getsockopt = j1939_sk_getsockopt,
1147 	.sendmsg = j1939_sk_sendmsg,
1148 	.recvmsg = j1939_sk_recvmsg,
1149 	.mmap = sock_no_mmap,
1150 	.sendpage = sock_no_sendpage,
1151 };
1152 
1153 static struct proto j1939_proto __read_mostly = {
1154 	.name = "CAN_J1939",
1155 	.owner = THIS_MODULE,
1156 	.obj_size = sizeof(struct j1939_sock),
1157 	.init = j1939_sk_init,
1158 };
1159 
1160 const struct can_proto j1939_can_proto = {
1161 	.type = SOCK_DGRAM,
1162 	.protocol = CAN_J1939,
1163 	.ops = &j1939_ops,
1164 	.prot = &j1939_proto,
1165 };
1166