xref: /openbmc/linux/net/can/j1939/transport.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2010-2011 EIA Electronics,
3 //                         Kurt Van Dijck <kurt.van.dijck@eia.be>
4 // Copyright (c) 2018 Protonic,
5 //                         Robin van der Gracht <robin@protonic.nl>
6 // Copyright (c) 2017-2019 Pengutronix,
7 //                         Marc Kleine-Budde <kernel@pengutronix.de>
8 // Copyright (c) 2017-2019 Pengutronix,
9 //                         Oleksij Rempel <kernel@pengutronix.de>
10 
11 #include <linux/can/skb.h>
12 
13 #include "j1939-priv.h"
14 
15 #define J1939_XTP_TX_RETRY_LIMIT 100
16 
17 #define J1939_ETP_PGN_CTL 0xc800
18 #define J1939_ETP_PGN_DAT 0xc700
19 #define J1939_TP_PGN_CTL 0xec00
20 #define J1939_TP_PGN_DAT 0xeb00
21 
22 #define J1939_TP_CMD_RTS 0x10
23 #define J1939_TP_CMD_CTS 0x11
24 #define J1939_TP_CMD_EOMA 0x13
25 #define J1939_TP_CMD_BAM 0x20
26 #define J1939_TP_CMD_ABORT 0xff
27 
28 #define J1939_ETP_CMD_RTS 0x14
29 #define J1939_ETP_CMD_CTS 0x15
30 #define J1939_ETP_CMD_DPO 0x16
31 #define J1939_ETP_CMD_EOMA 0x17
32 #define J1939_ETP_CMD_ABORT 0xff
33 
34 enum j1939_xtp_abort {
35 	J1939_XTP_NO_ABORT = 0,
36 	J1939_XTP_ABORT_BUSY = 1,
37 	/* Already in one or more connection managed sessions and
38 	 * cannot support another.
39 	 *
40 	 * EALREADY:
41 	 * Operation already in progress
42 	 */
43 
44 	J1939_XTP_ABORT_RESOURCE = 2,
45 	/* System resources were needed for another task so this
46 	 * connection managed session was terminated.
47 	 *
48 	 * EMSGSIZE:
49 	 * The socket type requires that message be sent atomically,
50 	 * and the size of the message to be sent made this
51 	 * impossible.
52 	 */
53 
54 	J1939_XTP_ABORT_TIMEOUT = 3,
55 	/* A timeout occurred and this is the connection abort to
56 	 * close the session.
57 	 *
58 	 * EHOSTUNREACH:
59 	 * The destination host cannot be reached (probably because
60 	 * the host is down or a remote router cannot reach it).
61 	 */
62 
63 	J1939_XTP_ABORT_GENERIC = 4,
64 	/* CTS messages received when data transfer is in progress
65 	 *
66 	 * EBADMSG:
67 	 * Not a data message
68 	 */
69 
70 	J1939_XTP_ABORT_FAULT = 5,
71 	/* Maximal retransmit request limit reached
72 	 *
73 	 * ENOTRECOVERABLE:
74 	 * State not recoverable
75 	 */
76 
77 	J1939_XTP_ABORT_UNEXPECTED_DATA = 6,
78 	/* Unexpected data transfer packet
79 	 *
80 	 * ENOTCONN:
81 	 * Transport endpoint is not connected
82 	 */
83 
84 	J1939_XTP_ABORT_BAD_SEQ = 7,
85 	/* Bad sequence number (and software is not able to recover)
86 	 *
87 	 * EILSEQ:
88 	 * Illegal byte sequence
89 	 */
90 
91 	J1939_XTP_ABORT_DUP_SEQ = 8,
92 	/* Duplicate sequence number (and software is not able to
93 	 * recover)
94 	 */
95 
96 	J1939_XTP_ABORT_EDPO_UNEXPECTED = 9,
97 	/* Unexpected EDPO packet (ETP) or Message size > 1785 bytes
98 	 * (TP)
99 	 */
100 
101 	J1939_XTP_ABORT_BAD_EDPO_PGN = 10,
102 	/* Unexpected EDPO PGN (PGN in EDPO is bad) */
103 
104 	J1939_XTP_ABORT_EDPO_OUTOF_CTS = 11,
105 	/* EDPO number of packets is greater than CTS */
106 
107 	J1939_XTP_ABORT_BAD_EDPO_OFFSET = 12,
108 	/* Bad EDPO offset */
109 
110 	J1939_XTP_ABORT_OTHER_DEPRECATED = 13,
111 	/* Deprecated. Use 250 instead (Any other reason)  */
112 
113 	J1939_XTP_ABORT_ECTS_UNXPECTED_PGN = 14,
114 	/* Unexpected ECTS PGN (PGN in ECTS is bad) */
115 
116 	J1939_XTP_ABORT_ECTS_TOO_BIG = 15,
117 	/* ECTS requested packets exceeds message size */
118 
119 	J1939_XTP_ABORT_OTHER = 250,
120 	/* Any other reason (if a Connection Abort reason is
121 	 * identified that is not listed in the table use code 250)
122 	 */
123 };
124 
125 static unsigned int j1939_tp_block = 255;
126 static unsigned int j1939_tp_packet_delay;
127 static unsigned int j1939_tp_padding = 1;
128 
129 /* helpers */
130 static const char *j1939_xtp_abort_to_str(enum j1939_xtp_abort abort)
131 {
132 	switch (abort) {
133 	case J1939_XTP_ABORT_BUSY:
134 		return "Already in one or more connection managed sessions and cannot support another.";
135 	case J1939_XTP_ABORT_RESOURCE:
136 		return "System resources were needed for another task so this connection managed session was terminated.";
137 	case J1939_XTP_ABORT_TIMEOUT:
138 		return "A timeout occurred and this is the connection abort to close the session.";
139 	case J1939_XTP_ABORT_GENERIC:
140 		return "CTS messages received when data transfer is in progress";
141 	case J1939_XTP_ABORT_FAULT:
142 		return "Maximal retransmit request limit reached";
143 	case J1939_XTP_ABORT_UNEXPECTED_DATA:
144 		return "Unexpected data transfer packet";
145 	case J1939_XTP_ABORT_BAD_SEQ:
146 		return "Bad sequence number (and software is not able to recover)";
147 	case J1939_XTP_ABORT_DUP_SEQ:
148 		return "Duplicate sequence number (and software is not able to recover)";
149 	case J1939_XTP_ABORT_EDPO_UNEXPECTED:
150 		return "Unexpected EDPO packet (ETP) or Message size > 1785 bytes (TP)";
151 	case J1939_XTP_ABORT_BAD_EDPO_PGN:
152 		return "Unexpected EDPO PGN (PGN in EDPO is bad)";
153 	case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
154 		return "EDPO number of packets is greater than CTS";
155 	case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
156 		return "Bad EDPO offset";
157 	case J1939_XTP_ABORT_OTHER_DEPRECATED:
158 		return "Deprecated. Use 250 instead (Any other reason)";
159 	case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
160 		return "Unexpected ECTS PGN (PGN in ECTS is bad)";
161 	case J1939_XTP_ABORT_ECTS_TOO_BIG:
162 		return "ECTS requested packets exceeds message size";
163 	case J1939_XTP_ABORT_OTHER:
164 		return "Any other reason (if a Connection Abort reason is identified that is not listed in the table use code 250)";
165 	default:
166 		return "<unknown>";
167 	}
168 }
169 
170 static int j1939_xtp_abort_to_errno(struct j1939_priv *priv,
171 				    enum j1939_xtp_abort abort)
172 {
173 	int err;
174 
175 	switch (abort) {
176 	case J1939_XTP_NO_ABORT:
177 		WARN_ON_ONCE(abort == J1939_XTP_NO_ABORT);
178 		err = 0;
179 		break;
180 	case J1939_XTP_ABORT_BUSY:
181 		err = EALREADY;
182 		break;
183 	case J1939_XTP_ABORT_RESOURCE:
184 		err = EMSGSIZE;
185 		break;
186 	case J1939_XTP_ABORT_TIMEOUT:
187 		err = EHOSTUNREACH;
188 		break;
189 	case J1939_XTP_ABORT_GENERIC:
190 		err = EBADMSG;
191 		break;
192 	case J1939_XTP_ABORT_FAULT:
193 		err = ENOTRECOVERABLE;
194 		break;
195 	case J1939_XTP_ABORT_UNEXPECTED_DATA:
196 		err = ENOTCONN;
197 		break;
198 	case J1939_XTP_ABORT_BAD_SEQ:
199 		err = EILSEQ;
200 		break;
201 	case J1939_XTP_ABORT_DUP_SEQ:
202 		err = EPROTO;
203 		break;
204 	case J1939_XTP_ABORT_EDPO_UNEXPECTED:
205 		err = EPROTO;
206 		break;
207 	case J1939_XTP_ABORT_BAD_EDPO_PGN:
208 		err = EPROTO;
209 		break;
210 	case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
211 		err = EPROTO;
212 		break;
213 	case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
214 		err = EPROTO;
215 		break;
216 	case J1939_XTP_ABORT_OTHER_DEPRECATED:
217 		err = EPROTO;
218 		break;
219 	case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
220 		err = EPROTO;
221 		break;
222 	case J1939_XTP_ABORT_ECTS_TOO_BIG:
223 		err = EPROTO;
224 		break;
225 	case J1939_XTP_ABORT_OTHER:
226 		err = EPROTO;
227 		break;
228 	default:
229 		netdev_warn(priv->ndev, "Unknown abort code %i", abort);
230 		err = EPROTO;
231 	}
232 
233 	return err;
234 }
235 
236 static inline void j1939_session_list_lock(struct j1939_priv *priv)
237 {
238 	spin_lock_bh(&priv->active_session_list_lock);
239 }
240 
241 static inline void j1939_session_list_unlock(struct j1939_priv *priv)
242 {
243 	spin_unlock_bh(&priv->active_session_list_lock);
244 }
245 
246 void j1939_session_get(struct j1939_session *session)
247 {
248 	kref_get(&session->kref);
249 }
250 
251 /* session completion functions */
252 static void __j1939_session_drop(struct j1939_session *session)
253 {
254 	if (!session->transmission)
255 		return;
256 
257 	j1939_sock_pending_del(session->sk);
258 	sock_put(session->sk);
259 }
260 
261 static void j1939_session_destroy(struct j1939_session *session)
262 {
263 	if (session->err)
264 		j1939_sk_errqueue(session, J1939_ERRQUEUE_ABORT);
265 	else
266 		j1939_sk_errqueue(session, J1939_ERRQUEUE_ACK);
267 
268 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
269 
270 	WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry));
271 	WARN_ON_ONCE(!list_empty(&session->active_session_list_entry));
272 
273 	skb_queue_purge(&session->skb_queue);
274 	__j1939_session_drop(session);
275 	j1939_priv_put(session->priv);
276 	kfree(session);
277 }
278 
279 static void __j1939_session_release(struct kref *kref)
280 {
281 	struct j1939_session *session = container_of(kref, struct j1939_session,
282 						     kref);
283 
284 	j1939_session_destroy(session);
285 }
286 
287 void j1939_session_put(struct j1939_session *session)
288 {
289 	kref_put(&session->kref, __j1939_session_release);
290 }
291 
292 static void j1939_session_txtimer_cancel(struct j1939_session *session)
293 {
294 	if (hrtimer_cancel(&session->txtimer))
295 		j1939_session_put(session);
296 }
297 
298 static void j1939_session_rxtimer_cancel(struct j1939_session *session)
299 {
300 	if (hrtimer_cancel(&session->rxtimer))
301 		j1939_session_put(session);
302 }
303 
304 void j1939_session_timers_cancel(struct j1939_session *session)
305 {
306 	j1939_session_txtimer_cancel(session);
307 	j1939_session_rxtimer_cancel(session);
308 }
309 
310 static inline bool j1939_cb_is_broadcast(const struct j1939_sk_buff_cb *skcb)
311 {
312 	return (!skcb->addr.dst_name && (skcb->addr.da == 0xff));
313 }
314 
315 static void j1939_session_skb_drop_old(struct j1939_session *session)
316 {
317 	struct sk_buff *do_skb;
318 	struct j1939_sk_buff_cb *do_skcb;
319 	unsigned int offset_start;
320 	unsigned long flags;
321 
322 	if (skb_queue_len(&session->skb_queue) < 2)
323 		return;
324 
325 	offset_start = session->pkt.tx_acked * 7;
326 
327 	spin_lock_irqsave(&session->skb_queue.lock, flags);
328 	do_skb = skb_peek(&session->skb_queue);
329 	do_skcb = j1939_skb_to_cb(do_skb);
330 
331 	if ((do_skcb->offset + do_skb->len) < offset_start) {
332 		__skb_unlink(do_skb, &session->skb_queue);
333 		kfree_skb(do_skb);
334 	}
335 	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
336 }
337 
338 void j1939_session_skb_queue(struct j1939_session *session,
339 			     struct sk_buff *skb)
340 {
341 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
342 	struct j1939_priv *priv = session->priv;
343 
344 	j1939_ac_fixup(priv, skb);
345 
346 	if (j1939_address_is_unicast(skcb->addr.da) &&
347 	    priv->ents[skcb->addr.da].nusers)
348 		skcb->flags |= J1939_ECU_LOCAL_DST;
349 
350 	skcb->flags |= J1939_ECU_LOCAL_SRC;
351 
352 	skb_queue_tail(&session->skb_queue, skb);
353 }
354 
355 static struct sk_buff *j1939_session_skb_find(struct j1939_session *session)
356 {
357 	struct j1939_priv *priv = session->priv;
358 	struct sk_buff *skb = NULL;
359 	struct sk_buff *do_skb;
360 	struct j1939_sk_buff_cb *do_skcb;
361 	unsigned int offset_start;
362 	unsigned long flags;
363 
364 	offset_start = session->pkt.dpo * 7;
365 
366 	spin_lock_irqsave(&session->skb_queue.lock, flags);
367 	skb_queue_walk(&session->skb_queue, do_skb) {
368 		do_skcb = j1939_skb_to_cb(do_skb);
369 
370 		if (offset_start >= do_skcb->offset &&
371 		    offset_start < (do_skcb->offset + do_skb->len)) {
372 			skb = do_skb;
373 		}
374 	}
375 	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
376 
377 	if (!skb)
378 		netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
379 			   __func__, session, offset_start,
380 			   skb_queue_len(&session->skb_queue));
381 
382 	return skb;
383 }
384 
385 /* see if we are receiver
386  * returns 0 for broadcasts, although we will receive them
387  */
388 static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
389 {
390 	return skcb->flags & J1939_ECU_LOCAL_DST;
391 }
392 
393 /* see if we are sender */
394 static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
395 {
396 	return skcb->flags & J1939_ECU_LOCAL_SRC;
397 }
398 
399 /* see if we are involved as either receiver or transmitter */
400 static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
401 {
402 	if (swap)
403 		return j1939_tp_im_receiver(skcb);
404 	else
405 		return j1939_tp_im_transmitter(skcb);
406 }
407 
408 static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
409 {
410 	return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
411 }
412 
413 /* extract pgn from flow-ctl message */
414 static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
415 {
416 	pgn_t pgn;
417 
418 	pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
419 	if (j1939_pgn_is_pdu1(pgn))
420 		pgn &= 0xffff00;
421 	return pgn;
422 }
423 
424 static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
425 {
426 	return (dat[2] << 8) + (dat[1] << 0);
427 }
428 
429 static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
430 {
431 	return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
432 }
433 
434 static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
435 {
436 	return (dat[4] << 24) | (dat[3] << 16) |
437 		(dat[2] << 8) | (dat[1] << 0);
438 }
439 
440 /* find existing session:
441  * reverse: swap cb's src & dst
442  * there is no problem with matching broadcasts, since
443  * broadcasts (no dst, no da) would never call this
444  * with reverse == true
445  */
446 static bool j1939_session_match(struct j1939_addr *se_addr,
447 				struct j1939_addr *sk_addr, bool reverse)
448 {
449 	if (se_addr->type != sk_addr->type)
450 		return false;
451 
452 	if (reverse) {
453 		if (se_addr->src_name) {
454 			if (se_addr->src_name != sk_addr->dst_name)
455 				return false;
456 		} else if (se_addr->sa != sk_addr->da) {
457 			return false;
458 		}
459 
460 		if (se_addr->dst_name) {
461 			if (se_addr->dst_name != sk_addr->src_name)
462 				return false;
463 		} else if (se_addr->da != sk_addr->sa) {
464 			return false;
465 		}
466 	} else {
467 		if (se_addr->src_name) {
468 			if (se_addr->src_name != sk_addr->src_name)
469 				return false;
470 		} else if (se_addr->sa != sk_addr->sa) {
471 			return false;
472 		}
473 
474 		if (se_addr->dst_name) {
475 			if (se_addr->dst_name != sk_addr->dst_name)
476 				return false;
477 		} else if (se_addr->da != sk_addr->da) {
478 			return false;
479 		}
480 	}
481 
482 	return true;
483 }
484 
485 static struct
486 j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
487 						struct list_head *root,
488 						struct j1939_addr *addr,
489 						bool reverse, bool transmitter)
490 {
491 	struct j1939_session *session;
492 
493 	lockdep_assert_held(&priv->active_session_list_lock);
494 
495 	list_for_each_entry(session, root, active_session_list_entry) {
496 		j1939_session_get(session);
497 		if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
498 		    session->transmission == transmitter)
499 			return session;
500 		j1939_session_put(session);
501 	}
502 
503 	return NULL;
504 }
505 
506 static struct
507 j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
508 					struct sk_buff *skb)
509 {
510 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
511 	struct j1939_session *session;
512 
513 	lockdep_assert_held(&priv->active_session_list_lock);
514 
515 	list_for_each_entry(session, &priv->active_session_list,
516 			    active_session_list_entry) {
517 		j1939_session_get(session);
518 		if (session->skcb.addr.type == J1939_SIMPLE &&
519 		    session->tskey == skcb->tskey && session->sk == skb->sk)
520 			return session;
521 		j1939_session_put(session);
522 	}
523 
524 	return NULL;
525 }
526 
527 static struct
528 j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
529 					 struct j1939_addr *addr,
530 					 bool reverse, bool transmitter)
531 {
532 	struct j1939_session *session;
533 
534 	j1939_session_list_lock(priv);
535 	session = j1939_session_get_by_addr_locked(priv,
536 						   &priv->active_session_list,
537 						   addr, reverse, transmitter);
538 	j1939_session_list_unlock(priv);
539 
540 	return session;
541 }
542 
543 static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
544 {
545 	u8 tmp = 0;
546 
547 	swap(skcb->addr.dst_name, skcb->addr.src_name);
548 	swap(skcb->addr.da, skcb->addr.sa);
549 
550 	/* swap SRC and DST flags, leave other untouched */
551 	if (skcb->flags & J1939_ECU_LOCAL_SRC)
552 		tmp |= J1939_ECU_LOCAL_DST;
553 	if (skcb->flags & J1939_ECU_LOCAL_DST)
554 		tmp |= J1939_ECU_LOCAL_SRC;
555 	skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
556 	skcb->flags |= tmp;
557 }
558 
559 static struct
560 sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
561 			     const struct j1939_sk_buff_cb *re_skcb,
562 			     bool ctl,
563 			     bool swap_src_dst)
564 {
565 	struct sk_buff *skb;
566 	struct j1939_sk_buff_cb *skcb;
567 
568 	skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
569 			GFP_ATOMIC);
570 	if (unlikely(!skb))
571 		return ERR_PTR(-ENOMEM);
572 
573 	skb->dev = priv->ndev;
574 	can_skb_reserve(skb);
575 	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
576 	/* reserve CAN header */
577 	skb_reserve(skb, offsetof(struct can_frame, data));
578 
579 	memcpy(skb->cb, re_skcb, sizeof(skb->cb));
580 	skcb = j1939_skb_to_cb(skb);
581 	if (swap_src_dst)
582 		j1939_skbcb_swap(skcb);
583 
584 	if (ctl) {
585 		if (skcb->addr.type == J1939_ETP)
586 			skcb->addr.pgn = J1939_ETP_PGN_CTL;
587 		else
588 			skcb->addr.pgn = J1939_TP_PGN_CTL;
589 	} else {
590 		if (skcb->addr.type == J1939_ETP)
591 			skcb->addr.pgn = J1939_ETP_PGN_DAT;
592 		else
593 			skcb->addr.pgn = J1939_TP_PGN_DAT;
594 	}
595 
596 	return skb;
597 }
598 
599 /* TP transmit packet functions */
600 static int j1939_tp_tx_dat(struct j1939_session *session,
601 			   const u8 *dat, int len)
602 {
603 	struct j1939_priv *priv = session->priv;
604 	struct sk_buff *skb;
605 
606 	skb = j1939_tp_tx_dat_new(priv, &session->skcb,
607 				  false, false);
608 	if (IS_ERR(skb))
609 		return PTR_ERR(skb);
610 
611 	skb_put_data(skb, dat, len);
612 	if (j1939_tp_padding && len < 8)
613 		memset(skb_put(skb, 8 - len), 0xff, 8 - len);
614 
615 	return j1939_send_one(priv, skb);
616 }
617 
618 static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
619 			       const struct j1939_sk_buff_cb *re_skcb,
620 			       bool swap_src_dst, pgn_t pgn, const u8 *dat)
621 {
622 	struct sk_buff *skb;
623 	u8 *skdat;
624 
625 	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
626 		return 0;
627 
628 	skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
629 	if (IS_ERR(skb))
630 		return PTR_ERR(skb);
631 
632 	skdat = skb_put(skb, 8);
633 	memcpy(skdat, dat, 5);
634 	skdat[5] = (pgn >> 0);
635 	skdat[6] = (pgn >> 8);
636 	skdat[7] = (pgn >> 16);
637 
638 	return j1939_send_one(priv, skb);
639 }
640 
641 static inline int j1939_tp_tx_ctl(struct j1939_session *session,
642 				  bool swap_src_dst, const u8 *dat)
643 {
644 	struct j1939_priv *priv = session->priv;
645 
646 	return j1939_xtp_do_tx_ctl(priv, &session->skcb,
647 				   swap_src_dst,
648 				   session->skcb.addr.pgn, dat);
649 }
650 
651 static int j1939_xtp_tx_abort(struct j1939_priv *priv,
652 			      const struct j1939_sk_buff_cb *re_skcb,
653 			      bool swap_src_dst,
654 			      enum j1939_xtp_abort err,
655 			      pgn_t pgn)
656 {
657 	u8 dat[5];
658 
659 	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
660 		return 0;
661 
662 	memset(dat, 0xff, sizeof(dat));
663 	dat[0] = J1939_TP_CMD_ABORT;
664 	dat[1] = err;
665 	return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
666 }
667 
668 void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
669 {
670 	j1939_session_get(session);
671 	hrtimer_start(&session->txtimer, ms_to_ktime(msec),
672 		      HRTIMER_MODE_REL_SOFT);
673 }
674 
675 static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
676 					  int msec)
677 {
678 	j1939_session_rxtimer_cancel(session);
679 	j1939_session_get(session);
680 	hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
681 		      HRTIMER_MODE_REL_SOFT);
682 }
683 
684 static int j1939_session_tx_rts(struct j1939_session *session)
685 {
686 	u8 dat[8];
687 	int ret;
688 
689 	memset(dat, 0xff, sizeof(dat));
690 
691 	dat[1] = (session->total_message_size >> 0);
692 	dat[2] = (session->total_message_size >> 8);
693 	dat[3] = session->pkt.total;
694 
695 	if (session->skcb.addr.type == J1939_ETP) {
696 		dat[0] = J1939_ETP_CMD_RTS;
697 		dat[1] = (session->total_message_size >> 0);
698 		dat[2] = (session->total_message_size >> 8);
699 		dat[3] = (session->total_message_size >> 16);
700 		dat[4] = (session->total_message_size >> 24);
701 	} else if (j1939_cb_is_broadcast(&session->skcb)) {
702 		dat[0] = J1939_TP_CMD_BAM;
703 		/* fake cts for broadcast */
704 		session->pkt.tx = 0;
705 	} else {
706 		dat[0] = J1939_TP_CMD_RTS;
707 		dat[4] = dat[3];
708 	}
709 
710 	if (dat[0] == session->last_txcmd)
711 		/* done already */
712 		return 0;
713 
714 	ret = j1939_tp_tx_ctl(session, false, dat);
715 	if (ret < 0)
716 		return ret;
717 
718 	session->last_txcmd = dat[0];
719 	if (dat[0] == J1939_TP_CMD_BAM)
720 		j1939_tp_schedule_txtimer(session, 50);
721 
722 	j1939_tp_set_rxtimeout(session, 1250);
723 
724 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
725 
726 	return 0;
727 }
728 
729 static int j1939_session_tx_dpo(struct j1939_session *session)
730 {
731 	unsigned int pkt;
732 	u8 dat[8];
733 	int ret;
734 
735 	memset(dat, 0xff, sizeof(dat));
736 
737 	dat[0] = J1939_ETP_CMD_DPO;
738 	session->pkt.dpo = session->pkt.tx_acked;
739 	pkt = session->pkt.dpo;
740 	dat[1] = session->pkt.last - session->pkt.tx_acked;
741 	dat[2] = (pkt >> 0);
742 	dat[3] = (pkt >> 8);
743 	dat[4] = (pkt >> 16);
744 
745 	ret = j1939_tp_tx_ctl(session, false, dat);
746 	if (ret < 0)
747 		return ret;
748 
749 	session->last_txcmd = dat[0];
750 	j1939_tp_set_rxtimeout(session, 1250);
751 	session->pkt.tx = session->pkt.tx_acked;
752 
753 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
754 
755 	return 0;
756 }
757 
758 static int j1939_session_tx_dat(struct j1939_session *session)
759 {
760 	struct j1939_priv *priv = session->priv;
761 	struct j1939_sk_buff_cb *skcb;
762 	int offset, pkt_done, pkt_end;
763 	unsigned int len, pdelay;
764 	struct sk_buff *se_skb;
765 	const u8 *tpdat;
766 	int ret = 0;
767 	u8 dat[8];
768 
769 	se_skb = j1939_session_skb_find(session);
770 	if (!se_skb)
771 		return -ENOBUFS;
772 
773 	skcb = j1939_skb_to_cb(se_skb);
774 	tpdat = se_skb->data;
775 	ret = 0;
776 	pkt_done = 0;
777 	if (session->skcb.addr.type != J1939_ETP &&
778 	    j1939_cb_is_broadcast(&session->skcb))
779 		pkt_end = session->pkt.total;
780 	else
781 		pkt_end = session->pkt.last;
782 
783 	while (session->pkt.tx < pkt_end) {
784 		dat[0] = session->pkt.tx - session->pkt.dpo + 1;
785 		offset = (session->pkt.tx * 7) - skcb->offset;
786 		len =  se_skb->len - offset;
787 		if (len > 7)
788 			len = 7;
789 
790 		memcpy(&dat[1], &tpdat[offset], len);
791 		ret = j1939_tp_tx_dat(session, dat, len + 1);
792 		if (ret < 0) {
793 			/* ENOBUS == CAN interface TX queue is full */
794 			if (ret != -ENOBUFS)
795 				netdev_alert(priv->ndev,
796 					     "%s: 0x%p: queue data error: %i\n",
797 					     __func__, session, ret);
798 			break;
799 		}
800 
801 		session->last_txcmd = 0xff;
802 		pkt_done++;
803 		session->pkt.tx++;
804 		pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
805 			j1939_tp_packet_delay;
806 
807 		if (session->pkt.tx < session->pkt.total && pdelay) {
808 			j1939_tp_schedule_txtimer(session, pdelay);
809 			break;
810 		}
811 	}
812 
813 	if (pkt_done)
814 		j1939_tp_set_rxtimeout(session, 250);
815 
816 	return ret;
817 }
818 
819 static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
820 {
821 	struct j1939_priv *priv = session->priv;
822 	int ret = 0;
823 
824 	if (!j1939_tp_im_transmitter(&session->skcb)) {
825 		netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
826 			     __func__, session);
827 		return -EINVAL;
828 	}
829 
830 	switch (session->last_cmd) {
831 	case 0:
832 		ret = j1939_session_tx_rts(session);
833 		break;
834 
835 	case J1939_ETP_CMD_CTS:
836 		if (session->last_txcmd != J1939_ETP_CMD_DPO) {
837 			ret = j1939_session_tx_dpo(session);
838 			if (ret)
839 				return ret;
840 		}
841 
842 		/* fall through */
843 	case J1939_TP_CMD_CTS:
844 	case 0xff: /* did some data */
845 	case J1939_ETP_CMD_DPO:
846 	case J1939_TP_CMD_BAM:
847 		ret = j1939_session_tx_dat(session);
848 
849 		break;
850 	default:
851 		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
852 			     __func__, session, session->last_cmd);
853 	}
854 
855 	return ret;
856 }
857 
858 static int j1939_session_tx_cts(struct j1939_session *session)
859 {
860 	struct j1939_priv *priv = session->priv;
861 	unsigned int pkt, len;
862 	int ret;
863 	u8 dat[8];
864 
865 	if (!j1939_sk_recv_match(priv, &session->skcb))
866 		return -ENOENT;
867 
868 	len = session->pkt.total - session->pkt.rx;
869 	len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
870 	memset(dat, 0xff, sizeof(dat));
871 
872 	if (session->skcb.addr.type == J1939_ETP) {
873 		pkt = session->pkt.rx + 1;
874 		dat[0] = J1939_ETP_CMD_CTS;
875 		dat[1] = len;
876 		dat[2] = (pkt >> 0);
877 		dat[3] = (pkt >> 8);
878 		dat[4] = (pkt >> 16);
879 	} else {
880 		dat[0] = J1939_TP_CMD_CTS;
881 		dat[1] = len;
882 		dat[2] = session->pkt.rx + 1;
883 	}
884 
885 	if (dat[0] == session->last_txcmd)
886 		/* done already */
887 		return 0;
888 
889 	ret = j1939_tp_tx_ctl(session, true, dat);
890 	if (ret < 0)
891 		return ret;
892 
893 	if (len)
894 		/* only mark cts done when len is set */
895 		session->last_txcmd = dat[0];
896 	j1939_tp_set_rxtimeout(session, 1250);
897 
898 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
899 
900 	return 0;
901 }
902 
903 static int j1939_session_tx_eoma(struct j1939_session *session)
904 {
905 	struct j1939_priv *priv = session->priv;
906 	u8 dat[8];
907 	int ret;
908 
909 	if (!j1939_sk_recv_match(priv, &session->skcb))
910 		return -ENOENT;
911 
912 	memset(dat, 0xff, sizeof(dat));
913 
914 	if (session->skcb.addr.type == J1939_ETP) {
915 		dat[0] = J1939_ETP_CMD_EOMA;
916 		dat[1] = session->total_message_size >> 0;
917 		dat[2] = session->total_message_size >> 8;
918 		dat[3] = session->total_message_size >> 16;
919 		dat[4] = session->total_message_size >> 24;
920 	} else {
921 		dat[0] = J1939_TP_CMD_EOMA;
922 		dat[1] = session->total_message_size;
923 		dat[2] = session->total_message_size >> 8;
924 		dat[3] = session->pkt.total;
925 	}
926 
927 	if (dat[0] == session->last_txcmd)
928 		/* done already */
929 		return 0;
930 
931 	ret = j1939_tp_tx_ctl(session, true, dat);
932 	if (ret < 0)
933 		return ret;
934 
935 	session->last_txcmd = dat[0];
936 
937 	/* wait for the EOMA packet to come in */
938 	j1939_tp_set_rxtimeout(session, 1250);
939 
940 	netdev_dbg(session->priv->ndev, "%p: 0x%p\n", __func__, session);
941 
942 	return 0;
943 }
944 
945 static int j1939_xtp_txnext_receiver(struct j1939_session *session)
946 {
947 	struct j1939_priv *priv = session->priv;
948 	int ret = 0;
949 
950 	if (!j1939_tp_im_receiver(&session->skcb)) {
951 		netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
952 			     __func__, session);
953 		return -EINVAL;
954 	}
955 
956 	switch (session->last_cmd) {
957 	case J1939_TP_CMD_RTS:
958 	case J1939_ETP_CMD_RTS:
959 		ret = j1939_session_tx_cts(session);
960 		break;
961 
962 	case J1939_ETP_CMD_CTS:
963 	case J1939_TP_CMD_CTS:
964 	case 0xff: /* did some data */
965 	case J1939_ETP_CMD_DPO:
966 		if ((session->skcb.addr.type == J1939_TP &&
967 		     j1939_cb_is_broadcast(&session->skcb)))
968 			break;
969 
970 		if (session->pkt.rx >= session->pkt.total) {
971 			ret = j1939_session_tx_eoma(session);
972 		} else if (session->pkt.rx >= session->pkt.last) {
973 			session->last_txcmd = 0;
974 			ret = j1939_session_tx_cts(session);
975 		}
976 		break;
977 	default:
978 		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
979 			     __func__, session, session->last_cmd);
980 	}
981 
982 	return ret;
983 }
984 
985 static int j1939_simple_txnext(struct j1939_session *session)
986 {
987 	struct j1939_priv *priv = session->priv;
988 	struct sk_buff *se_skb = j1939_session_skb_find(session);
989 	struct sk_buff *skb;
990 	int ret;
991 
992 	if (!se_skb)
993 		return 0;
994 
995 	skb = skb_clone(se_skb, GFP_ATOMIC);
996 	if (!skb)
997 		return -ENOMEM;
998 
999 	can_skb_set_owner(skb, se_skb->sk);
1000 
1001 	j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
1002 
1003 	ret = j1939_send_one(priv, skb);
1004 	if (ret)
1005 		return ret;
1006 
1007 	j1939_sk_errqueue(session, J1939_ERRQUEUE_SCHED);
1008 	j1939_sk_queue_activate_next(session);
1009 
1010 	return 0;
1011 }
1012 
1013 static bool j1939_session_deactivate_locked(struct j1939_session *session)
1014 {
1015 	bool active = false;
1016 
1017 	lockdep_assert_held(&session->priv->active_session_list_lock);
1018 
1019 	if (session->state >= J1939_SESSION_ACTIVE &&
1020 	    session->state < J1939_SESSION_ACTIVE_MAX) {
1021 		active = true;
1022 
1023 		list_del_init(&session->active_session_list_entry);
1024 		session->state = J1939_SESSION_DONE;
1025 		j1939_session_put(session);
1026 	}
1027 
1028 	return active;
1029 }
1030 
1031 static bool j1939_session_deactivate(struct j1939_session *session)
1032 {
1033 	bool active;
1034 
1035 	j1939_session_list_lock(session->priv);
1036 	active = j1939_session_deactivate_locked(session);
1037 	j1939_session_list_unlock(session->priv);
1038 
1039 	return active;
1040 }
1041 
1042 static void
1043 j1939_session_deactivate_activate_next(struct j1939_session *session)
1044 {
1045 	if (j1939_session_deactivate(session))
1046 		j1939_sk_queue_activate_next(session);
1047 }
1048 
1049 static void __j1939_session_cancel(struct j1939_session *session,
1050 				 enum j1939_xtp_abort err)
1051 {
1052 	struct j1939_priv *priv = session->priv;
1053 
1054 	WARN_ON_ONCE(!err);
1055 	lockdep_assert_held(&session->priv->active_session_list_lock);
1056 
1057 	session->err = j1939_xtp_abort_to_errno(priv, err);
1058 	/* do not send aborts on incoming broadcasts */
1059 	if (!j1939_cb_is_broadcast(&session->skcb)) {
1060 		session->state = J1939_SESSION_WAITING_ABORT;
1061 		j1939_xtp_tx_abort(priv, &session->skcb,
1062 				   !session->transmission,
1063 				   err, session->skcb.addr.pgn);
1064 	}
1065 
1066 	if (session->sk)
1067 		j1939_sk_send_loop_abort(session->sk, session->err);
1068 }
1069 
1070 static void j1939_session_cancel(struct j1939_session *session,
1071 				 enum j1939_xtp_abort err)
1072 {
1073 	j1939_session_list_lock(session->priv);
1074 
1075 	if (session->state >= J1939_SESSION_ACTIVE &&
1076 	    session->state < J1939_SESSION_WAITING_ABORT) {
1077 		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
1078 		__j1939_session_cancel(session, err);
1079 	}
1080 
1081 	j1939_session_list_unlock(session->priv);
1082 }
1083 
1084 static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
1085 {
1086 	struct j1939_session *session =
1087 		container_of(hrtimer, struct j1939_session, txtimer);
1088 	struct j1939_priv *priv = session->priv;
1089 	int ret = 0;
1090 
1091 	if (session->skcb.addr.type == J1939_SIMPLE) {
1092 		ret = j1939_simple_txnext(session);
1093 	} else {
1094 		if (session->transmission)
1095 			ret = j1939_xtp_txnext_transmiter(session);
1096 		else
1097 			ret = j1939_xtp_txnext_receiver(session);
1098 	}
1099 
1100 	switch (ret) {
1101 	case -ENOBUFS:
1102 		/* Retry limit is currently arbitrary chosen */
1103 		if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
1104 			session->tx_retry++;
1105 			j1939_tp_schedule_txtimer(session,
1106 						  10 + prandom_u32_max(16));
1107 		} else {
1108 			netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
1109 				     __func__, session);
1110 			session->err = -ENETUNREACH;
1111 			j1939_session_rxtimer_cancel(session);
1112 			j1939_session_deactivate_activate_next(session);
1113 		}
1114 		break;
1115 	case -ENETDOWN:
1116 		/* In this case we should get a netdev_event(), all active
1117 		 * sessions will be cleared by
1118 		 * j1939_cancel_all_active_sessions(). So handle this as an
1119 		 * error, but let j1939_cancel_all_active_sessions() do the
1120 		 * cleanup including propagation of the error to user space.
1121 		 */
1122 		break;
1123 	case 0:
1124 		session->tx_retry = 0;
1125 		break;
1126 	default:
1127 		netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
1128 			     __func__, session, ret);
1129 		if (session->skcb.addr.type != J1939_SIMPLE) {
1130 			j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
1131 		} else {
1132 			session->err = ret;
1133 			j1939_session_rxtimer_cancel(session);
1134 			j1939_session_deactivate_activate_next(session);
1135 		}
1136 	}
1137 
1138 	j1939_session_put(session);
1139 
1140 	return HRTIMER_NORESTART;
1141 }
1142 
1143 static void j1939_session_completed(struct j1939_session *session)
1144 {
1145 	struct sk_buff *skb;
1146 
1147 	if (!session->transmission) {
1148 		skb = j1939_session_skb_find(session);
1149 		/* distribute among j1939 receivers */
1150 		j1939_sk_recv(session->priv, skb);
1151 	}
1152 
1153 	j1939_session_deactivate_activate_next(session);
1154 }
1155 
1156 static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
1157 {
1158 	struct j1939_session *session = container_of(hrtimer,
1159 						     struct j1939_session,
1160 						     rxtimer);
1161 	struct j1939_priv *priv = session->priv;
1162 
1163 	if (session->state == J1939_SESSION_WAITING_ABORT) {
1164 		netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
1165 			     __func__, session);
1166 
1167 		j1939_session_deactivate_activate_next(session);
1168 
1169 	} else if (session->skcb.addr.type == J1939_SIMPLE) {
1170 		netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
1171 			     __func__, session);
1172 
1173 		/* The message is probably stuck in the CAN controller and can
1174 		 * be send as soon as CAN bus is in working state again.
1175 		 */
1176 		session->err = -ETIME;
1177 		j1939_session_deactivate(session);
1178 	} else {
1179 		netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
1180 			     __func__, session);
1181 
1182 		j1939_session_list_lock(session->priv);
1183 		if (session->state >= J1939_SESSION_ACTIVE &&
1184 		    session->state < J1939_SESSION_ACTIVE_MAX) {
1185 			j1939_session_get(session);
1186 			hrtimer_start(&session->rxtimer,
1187 				      ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
1188 				      HRTIMER_MODE_REL_SOFT);
1189 			__j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
1190 		}
1191 		j1939_session_list_unlock(session->priv);
1192 	}
1193 
1194 	j1939_session_put(session);
1195 
1196 	return HRTIMER_NORESTART;
1197 }
1198 
1199 static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
1200 				     const struct sk_buff *skb)
1201 {
1202 	const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1203 	pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
1204 	struct j1939_priv *priv = session->priv;
1205 	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1206 	u8 cmd = skb->data[0];
1207 
1208 	if (session->skcb.addr.pgn == pgn)
1209 		return false;
1210 
1211 	switch (cmd) {
1212 	case J1939_TP_CMD_BAM:
1213 		abort = J1939_XTP_NO_ABORT;
1214 		break;
1215 
1216 	case J1939_ETP_CMD_RTS:
1217 	case J1939_TP_CMD_RTS: /* fall through */
1218 		abort = J1939_XTP_ABORT_BUSY;
1219 		break;
1220 
1221 	case J1939_ETP_CMD_CTS:
1222 	case J1939_TP_CMD_CTS: /* fall through */
1223 		abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
1224 		break;
1225 
1226 	case J1939_ETP_CMD_DPO:
1227 		abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
1228 		break;
1229 
1230 	case J1939_ETP_CMD_EOMA:
1231 	case J1939_TP_CMD_EOMA: /* fall through */
1232 		abort = J1939_XTP_ABORT_OTHER;
1233 		break;
1234 
1235 	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
1236 		abort = J1939_XTP_NO_ABORT;
1237 		break;
1238 
1239 	default:
1240 		WARN_ON_ONCE(1);
1241 		break;
1242 	}
1243 
1244 	netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
1245 		    __func__, session, cmd, pgn, session->skcb.addr.pgn);
1246 	if (abort != J1939_XTP_NO_ABORT)
1247 		j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
1248 
1249 	return true;
1250 }
1251 
1252 static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
1253 				   bool reverse, bool transmitter)
1254 {
1255 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1256 	struct j1939_session *session;
1257 	u8 abort = skb->data[1];
1258 
1259 	session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
1260 					    transmitter);
1261 	if (!session)
1262 		return;
1263 
1264 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1265 		goto abort_put;
1266 
1267 	netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
1268 		    session, j1939_xtp_ctl_to_pgn(skb->data), abort,
1269 		    j1939_xtp_abort_to_str(abort));
1270 
1271 	j1939_session_timers_cancel(session);
1272 	session->err = j1939_xtp_abort_to_errno(priv, abort);
1273 	if (session->sk)
1274 		j1939_sk_send_loop_abort(session->sk, session->err);
1275 	j1939_session_deactivate_activate_next(session);
1276 
1277 abort_put:
1278 	j1939_session_put(session);
1279 }
1280 
1281 /* abort packets may come in 2 directions */
1282 static void
1283 j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
1284 		   bool transmitter)
1285 {
1286 	j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
1287 	j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
1288 }
1289 
1290 static void
1291 j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
1292 {
1293 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1294 	const u8 *dat;
1295 	int len;
1296 
1297 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1298 		return;
1299 
1300 	dat = skb->data;
1301 
1302 	if (skcb->addr.type == J1939_ETP)
1303 		len = j1939_etp_ctl_to_size(dat);
1304 	else
1305 		len = j1939_tp_ctl_to_size(dat);
1306 
1307 	if (session->total_message_size != len) {
1308 		netdev_warn_once(session->priv->ndev,
1309 				 "%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
1310 				 __func__, session, session->total_message_size,
1311 				 len);
1312 	}
1313 
1314 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1315 
1316 	session->pkt.tx_acked = session->pkt.total;
1317 	j1939_session_timers_cancel(session);
1318 	/* transmitted without problems */
1319 	j1939_session_completed(session);
1320 }
1321 
1322 static void
1323 j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
1324 		  bool transmitter)
1325 {
1326 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1327 	struct j1939_session *session;
1328 
1329 	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1330 					    transmitter);
1331 	if (!session)
1332 		return;
1333 
1334 	j1939_xtp_rx_eoma_one(session, skb);
1335 	j1939_session_put(session);
1336 }
1337 
1338 static void
1339 j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
1340 {
1341 	enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
1342 	unsigned int pkt;
1343 	const u8 *dat;
1344 
1345 	dat = skb->data;
1346 
1347 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1348 		return;
1349 
1350 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1351 
1352 	if (session->last_cmd == dat[0]) {
1353 		err = J1939_XTP_ABORT_DUP_SEQ;
1354 		goto out_session_cancel;
1355 	}
1356 
1357 	if (session->skcb.addr.type == J1939_ETP)
1358 		pkt = j1939_etp_ctl_to_packet(dat);
1359 	else
1360 		pkt = dat[2];
1361 
1362 	if (!pkt)
1363 		goto out_session_cancel;
1364 	else if (dat[1] > session->pkt.block /* 0xff for etp */)
1365 		goto out_session_cancel;
1366 
1367 	/* set packet counters only when not CTS(0) */
1368 	session->pkt.tx_acked = pkt - 1;
1369 	j1939_session_skb_drop_old(session);
1370 	session->pkt.last = session->pkt.tx_acked + dat[1];
1371 	if (session->pkt.last > session->pkt.total)
1372 		/* safety measure */
1373 		session->pkt.last = session->pkt.total;
1374 	/* TODO: do not set tx here, do it in txtimer */
1375 	session->pkt.tx = session->pkt.tx_acked;
1376 
1377 	session->last_cmd = dat[0];
1378 	if (dat[1]) {
1379 		j1939_tp_set_rxtimeout(session, 1250);
1380 		if (session->transmission) {
1381 			if (session->pkt.tx_acked)
1382 				j1939_sk_errqueue(session,
1383 						  J1939_ERRQUEUE_SCHED);
1384 			j1939_session_txtimer_cancel(session);
1385 			j1939_tp_schedule_txtimer(session, 0);
1386 		}
1387 	} else {
1388 		/* CTS(0) */
1389 		j1939_tp_set_rxtimeout(session, 550);
1390 	}
1391 	return;
1392 
1393  out_session_cancel:
1394 	j1939_session_timers_cancel(session);
1395 	j1939_session_cancel(session, err);
1396 }
1397 
1398 static void
1399 j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
1400 {
1401 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1402 	struct j1939_session *session;
1403 
1404 	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1405 					    transmitter);
1406 	if (!session)
1407 		return;
1408 	j1939_xtp_rx_cts_one(session, skb);
1409 	j1939_session_put(session);
1410 }
1411 
1412 static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
1413 					       struct sk_buff *skb, size_t size)
1414 {
1415 	struct j1939_session *session;
1416 	struct j1939_sk_buff_cb *skcb;
1417 
1418 	session = kzalloc(sizeof(*session), gfp_any());
1419 	if (!session)
1420 		return NULL;
1421 
1422 	INIT_LIST_HEAD(&session->active_session_list_entry);
1423 	INIT_LIST_HEAD(&session->sk_session_queue_entry);
1424 	kref_init(&session->kref);
1425 
1426 	j1939_priv_get(priv);
1427 	session->priv = priv;
1428 	session->total_message_size = size;
1429 	session->state = J1939_SESSION_NEW;
1430 
1431 	skb_queue_head_init(&session->skb_queue);
1432 	skb_queue_tail(&session->skb_queue, skb);
1433 
1434 	skcb = j1939_skb_to_cb(skb);
1435 	memcpy(&session->skcb, skcb, sizeof(session->skcb));
1436 
1437 	hrtimer_init(&session->txtimer, CLOCK_MONOTONIC,
1438 		     HRTIMER_MODE_REL_SOFT);
1439 	session->txtimer.function = j1939_tp_txtimer;
1440 	hrtimer_init(&session->rxtimer, CLOCK_MONOTONIC,
1441 		     HRTIMER_MODE_REL_SOFT);
1442 	session->rxtimer.function = j1939_tp_rxtimer;
1443 
1444 	netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
1445 		   __func__, session, skcb->addr.sa, skcb->addr.da);
1446 
1447 	return session;
1448 }
1449 
1450 static struct
1451 j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
1452 				       int size,
1453 				       const struct j1939_sk_buff_cb *rel_skcb)
1454 {
1455 	struct sk_buff *skb;
1456 	struct j1939_sk_buff_cb *skcb;
1457 	struct j1939_session *session;
1458 
1459 	skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
1460 	if (unlikely(!skb))
1461 		return NULL;
1462 
1463 	skb->dev = priv->ndev;
1464 	can_skb_reserve(skb);
1465 	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
1466 	skcb = j1939_skb_to_cb(skb);
1467 	memcpy(skcb, rel_skcb, sizeof(*skcb));
1468 
1469 	session = j1939_session_new(priv, skb, size);
1470 	if (!session) {
1471 		kfree_skb(skb);
1472 		return NULL;
1473 	}
1474 
1475 	/* alloc data area */
1476 	skb_put(skb, size);
1477 	/* skb is recounted in j1939_session_new() */
1478 	return session;
1479 }
1480 
1481 int j1939_session_activate(struct j1939_session *session)
1482 {
1483 	struct j1939_priv *priv = session->priv;
1484 	struct j1939_session *active = NULL;
1485 	int ret = 0;
1486 
1487 	j1939_session_list_lock(priv);
1488 	if (session->skcb.addr.type != J1939_SIMPLE)
1489 		active = j1939_session_get_by_addr_locked(priv,
1490 							  &priv->active_session_list,
1491 							  &session->skcb.addr, false,
1492 							  session->transmission);
1493 	if (active) {
1494 		j1939_session_put(active);
1495 		ret = -EAGAIN;
1496 	} else {
1497 		WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
1498 		list_add_tail(&session->active_session_list_entry,
1499 			      &priv->active_session_list);
1500 		j1939_session_get(session);
1501 		session->state = J1939_SESSION_ACTIVE;
1502 
1503 		netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
1504 			   __func__, session);
1505 	}
1506 	j1939_session_list_unlock(priv);
1507 
1508 	return ret;
1509 }
1510 
1511 static struct
1512 j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
1513 					    struct sk_buff *skb)
1514 {
1515 	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1516 	struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
1517 	struct j1939_session *session;
1518 	const u8 *dat;
1519 	pgn_t pgn;
1520 	int len;
1521 
1522 	netdev_dbg(priv->ndev, "%s\n", __func__);
1523 
1524 	dat = skb->data;
1525 	pgn = j1939_xtp_ctl_to_pgn(dat);
1526 	skcb.addr.pgn = pgn;
1527 
1528 	if (!j1939_sk_recv_match(priv, &skcb))
1529 		return NULL;
1530 
1531 	if (skcb.addr.type == J1939_ETP) {
1532 		len = j1939_etp_ctl_to_size(dat);
1533 		if (len > J1939_MAX_ETP_PACKET_SIZE)
1534 			abort = J1939_XTP_ABORT_FAULT;
1535 		else if (len > priv->tp_max_packet_size)
1536 			abort = J1939_XTP_ABORT_RESOURCE;
1537 		else if (len <= J1939_MAX_TP_PACKET_SIZE)
1538 			abort = J1939_XTP_ABORT_FAULT;
1539 	} else {
1540 		len = j1939_tp_ctl_to_size(dat);
1541 		if (len > J1939_MAX_TP_PACKET_SIZE)
1542 			abort = J1939_XTP_ABORT_FAULT;
1543 		else if (len > priv->tp_max_packet_size)
1544 			abort = J1939_XTP_ABORT_RESOURCE;
1545 	}
1546 
1547 	if (abort != J1939_XTP_NO_ABORT) {
1548 		j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
1549 		return NULL;
1550 	}
1551 
1552 	session = j1939_session_fresh_new(priv, len, &skcb);
1553 	if (!session) {
1554 		j1939_xtp_tx_abort(priv, &skcb, true,
1555 				   J1939_XTP_ABORT_RESOURCE, pgn);
1556 		return NULL;
1557 	}
1558 
1559 	/* initialize the control buffer: plain copy */
1560 	session->pkt.total = (len + 6) / 7;
1561 	session->pkt.block = 0xff;
1562 	if (skcb.addr.type != J1939_ETP) {
1563 		if (dat[3] != session->pkt.total)
1564 			netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
1565 				     __func__, session, session->pkt.total,
1566 				     dat[3]);
1567 		session->pkt.total = dat[3];
1568 		session->pkt.block = min(dat[3], dat[4]);
1569 	}
1570 
1571 	session->pkt.rx = 0;
1572 	session->pkt.tx = 0;
1573 
1574 	WARN_ON_ONCE(j1939_session_activate(session));
1575 
1576 	return session;
1577 }
1578 
1579 static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
1580 					   struct sk_buff *skb)
1581 {
1582 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1583 	struct j1939_priv *priv = session->priv;
1584 
1585 	if (!session->transmission) {
1586 		if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1587 			return -EBUSY;
1588 
1589 		/* RTS on active session */
1590 		j1939_session_timers_cancel(session);
1591 		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1592 	}
1593 
1594 	if (session->last_cmd != 0) {
1595 		/* we received a second rts on the same connection */
1596 		netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
1597 			     __func__, session, skcb->addr.sa, skcb->addr.da,
1598 			     session->last_cmd);
1599 
1600 		j1939_session_timers_cancel(session);
1601 		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1602 
1603 		return -EBUSY;
1604 	}
1605 
1606 	if (session->skcb.addr.sa != skcb->addr.sa ||
1607 	    session->skcb.addr.da != skcb->addr.da)
1608 		netdev_warn(priv->ndev, "%s: 0x%p: session->skcb.addr.sa=0x%02x skcb->addr.sa=0x%02x session->skcb.addr.da=0x%02x skcb->addr.da=0x%02x\n",
1609 			    __func__, session,
1610 			    session->skcb.addr.sa, skcb->addr.sa,
1611 			    session->skcb.addr.da, skcb->addr.da);
1612 	/* make sure 'sa' & 'da' are correct !
1613 	 * They may be 'not filled in yet' for sending
1614 	 * skb's, since they did not pass the Address Claim ever.
1615 	 */
1616 	session->skcb.addr.sa = skcb->addr.sa;
1617 	session->skcb.addr.da = skcb->addr.da;
1618 
1619 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1620 
1621 	return 0;
1622 }
1623 
1624 static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
1625 			     bool transmitter)
1626 {
1627 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1628 	struct j1939_session *session;
1629 	u8 cmd = skb->data[0];
1630 
1631 	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1632 					    transmitter);
1633 
1634 	if (!session) {
1635 		if (transmitter) {
1636 			/* If we're the transmitter and this function is called,
1637 			 * we received our own RTS. A session has already been
1638 			 * created.
1639 			 *
1640 			 * For some reasons however it might have been destroyed
1641 			 * already. So don't create a new one here (using
1642 			 * "j1939_xtp_rx_rts_session_new()") as this will be a
1643 			 * receiver session.
1644 			 *
1645 			 * The reasons the session is already destroyed might
1646 			 * be:
1647 			 * - user space closed socket was and the session was
1648 			 *   aborted
1649 			 * - session was aborted due to external abort message
1650 			 */
1651 			return;
1652 		}
1653 		session = j1939_xtp_rx_rts_session_new(priv, skb);
1654 		if (!session)
1655 			return;
1656 	} else {
1657 		if (j1939_xtp_rx_rts_session_active(session, skb)) {
1658 			j1939_session_put(session);
1659 			return;
1660 		}
1661 	}
1662 	session->last_cmd = cmd;
1663 
1664 	j1939_tp_set_rxtimeout(session, 1250);
1665 
1666 	if (cmd != J1939_TP_CMD_BAM && !session->transmission) {
1667 		j1939_session_txtimer_cancel(session);
1668 		j1939_tp_schedule_txtimer(session, 0);
1669 	}
1670 
1671 	j1939_session_put(session);
1672 }
1673 
1674 static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
1675 				 struct sk_buff *skb)
1676 {
1677 	const u8 *dat = skb->data;
1678 
1679 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1680 		return;
1681 
1682 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1683 
1684 	/* transmitted without problems */
1685 	session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
1686 	session->last_cmd = dat[0];
1687 	j1939_tp_set_rxtimeout(session, 750);
1688 }
1689 
1690 static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
1691 			     bool transmitter)
1692 {
1693 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1694 	struct j1939_session *session;
1695 
1696 	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1697 					    transmitter);
1698 	if (!session) {
1699 		netdev_info(priv->ndev,
1700 			    "%s: no connection found\n", __func__);
1701 		return;
1702 	}
1703 
1704 	j1939_xtp_rx_dpo_one(session, skb);
1705 	j1939_session_put(session);
1706 }
1707 
1708 static void j1939_xtp_rx_dat_one(struct j1939_session *session,
1709 				 struct sk_buff *skb)
1710 {
1711 	struct j1939_priv *priv = session->priv;
1712 	struct j1939_sk_buff_cb *skcb;
1713 	struct sk_buff *se_skb;
1714 	const u8 *dat;
1715 	u8 *tpdat;
1716 	int offset;
1717 	int nbytes;
1718 	bool final = false;
1719 	bool do_cts_eoma = false;
1720 	int packet;
1721 
1722 	skcb = j1939_skb_to_cb(skb);
1723 	dat = skb->data;
1724 	if (skb->len <= 1)
1725 		/* makes no sense */
1726 		goto out_session_cancel;
1727 
1728 	switch (session->last_cmd) {
1729 	case 0xff:
1730 		break;
1731 	case J1939_ETP_CMD_DPO:
1732 		if (skcb->addr.type == J1939_ETP)
1733 			break;
1734 		/* fall through */
1735 	case J1939_TP_CMD_BAM: /* fall through */
1736 	case J1939_TP_CMD_CTS: /* fall through */
1737 		if (skcb->addr.type != J1939_ETP)
1738 			break;
1739 		/* fall through */
1740 	default:
1741 		netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
1742 			    session, session->last_cmd);
1743 		goto out_session_cancel;
1744 	}
1745 
1746 	packet = (dat[0] - 1 + session->pkt.dpo);
1747 	if (packet > session->pkt.total ||
1748 	    (session->pkt.rx + 1) > session->pkt.total) {
1749 		netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
1750 			    __func__, session);
1751 		goto out_session_cancel;
1752 	}
1753 	se_skb = j1939_session_skb_find(session);
1754 	if (!se_skb) {
1755 		netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
1756 			    session);
1757 		goto out_session_cancel;
1758 	}
1759 
1760 	skcb = j1939_skb_to_cb(se_skb);
1761 	offset = packet * 7 - skcb->offset;
1762 	nbytes = se_skb->len - offset;
1763 	if (nbytes > 7)
1764 		nbytes = 7;
1765 	if (nbytes <= 0 || (nbytes + 1) > skb->len) {
1766 		netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
1767 			    __func__, session, nbytes, skb->len);
1768 		goto out_session_cancel;
1769 	}
1770 
1771 	tpdat = se_skb->data;
1772 	memcpy(&tpdat[offset], &dat[1], nbytes);
1773 	if (packet == session->pkt.rx)
1774 		session->pkt.rx++;
1775 
1776 	if (skcb->addr.type != J1939_ETP &&
1777 	    j1939_cb_is_broadcast(&session->skcb)) {
1778 		if (session->pkt.rx >= session->pkt.total)
1779 			final = true;
1780 	} else {
1781 		/* never final, an EOMA must follow */
1782 		if (session->pkt.rx >= session->pkt.last)
1783 			do_cts_eoma = true;
1784 	}
1785 
1786 	if (final) {
1787 		j1939_session_completed(session);
1788 	} else if (do_cts_eoma) {
1789 		j1939_tp_set_rxtimeout(session, 1250);
1790 		if (!session->transmission)
1791 			j1939_tp_schedule_txtimer(session, 0);
1792 	} else {
1793 		j1939_tp_set_rxtimeout(session, 250);
1794 	}
1795 	session->last_cmd = 0xff;
1796 	j1939_session_put(session);
1797 
1798 	return;
1799 
1800  out_session_cancel:
1801 	j1939_session_timers_cancel(session);
1802 	j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
1803 	j1939_session_put(session);
1804 }
1805 
1806 static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
1807 {
1808 	struct j1939_sk_buff_cb *skcb;
1809 	struct j1939_session *session;
1810 
1811 	skcb = j1939_skb_to_cb(skb);
1812 
1813 	if (j1939_tp_im_transmitter(skcb)) {
1814 		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1815 						    true);
1816 		if (!session)
1817 			netdev_info(priv->ndev, "%s: no tx connection found\n",
1818 				    __func__);
1819 		else
1820 			j1939_xtp_rx_dat_one(session, skb);
1821 	}
1822 
1823 	if (j1939_tp_im_receiver(skcb)) {
1824 		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1825 						    false);
1826 		if (!session)
1827 			netdev_info(priv->ndev, "%s: no rx connection found\n",
1828 				    __func__);
1829 		else
1830 			j1939_xtp_rx_dat_one(session, skb);
1831 	}
1832 }
1833 
1834 /* j1939 main intf */
1835 struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
1836 				    struct sk_buff *skb, size_t size)
1837 {
1838 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1839 	struct j1939_session *session;
1840 	int ret;
1841 
1842 	if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
1843 	    skcb->addr.pgn == J1939_TP_PGN_CTL ||
1844 	    skcb->addr.pgn == J1939_ETP_PGN_DAT ||
1845 	    skcb->addr.pgn == J1939_ETP_PGN_CTL)
1846 		/* avoid conflict */
1847 		return ERR_PTR(-EDOM);
1848 
1849 	if (size > priv->tp_max_packet_size)
1850 		return ERR_PTR(-EMSGSIZE);
1851 
1852 	if (size <= 8)
1853 		skcb->addr.type = J1939_SIMPLE;
1854 	else if (size > J1939_MAX_TP_PACKET_SIZE)
1855 		skcb->addr.type = J1939_ETP;
1856 	else
1857 		skcb->addr.type = J1939_TP;
1858 
1859 	if (skcb->addr.type == J1939_ETP &&
1860 	    j1939_cb_is_broadcast(skcb))
1861 		return ERR_PTR(-EDESTADDRREQ);
1862 
1863 	/* fill in addresses from names */
1864 	ret = j1939_ac_fixup(priv, skb);
1865 	if (unlikely(ret))
1866 		return ERR_PTR(ret);
1867 
1868 	/* fix DST flags, it may be used there soon */
1869 	if (j1939_address_is_unicast(skcb->addr.da) &&
1870 	    priv->ents[skcb->addr.da].nusers)
1871 		skcb->flags |= J1939_ECU_LOCAL_DST;
1872 
1873 	/* src is always local, I'm sending ... */
1874 	skcb->flags |= J1939_ECU_LOCAL_SRC;
1875 
1876 	/* prepare new session */
1877 	session = j1939_session_new(priv, skb, size);
1878 	if (!session)
1879 		return ERR_PTR(-ENOMEM);
1880 
1881 	/* skb is recounted in j1939_session_new() */
1882 	sock_hold(skb->sk);
1883 	session->sk = skb->sk;
1884 	session->transmission = true;
1885 	session->pkt.total = (size + 6) / 7;
1886 	session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
1887 		min(j1939_tp_block ?: 255, session->pkt.total);
1888 
1889 	if (j1939_cb_is_broadcast(&session->skcb))
1890 		/* set the end-packet for broadcast */
1891 		session->pkt.last = session->pkt.total;
1892 
1893 	skcb->tskey = session->sk->sk_tskey++;
1894 	session->tskey = skcb->tskey;
1895 
1896 	return session;
1897 }
1898 
1899 static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
1900 {
1901 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1902 	int extd = J1939_TP;
1903 	u8 cmd = skb->data[0];
1904 
1905 	switch (cmd) {
1906 	case J1939_ETP_CMD_RTS:
1907 		extd = J1939_ETP;
1908 		/* fall through */
1909 	case J1939_TP_CMD_BAM: /* fall through */
1910 	case J1939_TP_CMD_RTS: /* fall through */
1911 		if (skcb->addr.type != extd)
1912 			return;
1913 
1914 		if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
1915 			netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
1916 				     __func__, skcb->addr.sa);
1917 			return;
1918 		}
1919 
1920 		if (j1939_tp_im_transmitter(skcb))
1921 			j1939_xtp_rx_rts(priv, skb, true);
1922 
1923 		if (j1939_tp_im_receiver(skcb))
1924 			j1939_xtp_rx_rts(priv, skb, false);
1925 
1926 		break;
1927 
1928 	case J1939_ETP_CMD_CTS:
1929 		extd = J1939_ETP;
1930 		/* fall through */
1931 	case J1939_TP_CMD_CTS:
1932 		if (skcb->addr.type != extd)
1933 			return;
1934 
1935 		if (j1939_tp_im_transmitter(skcb))
1936 			j1939_xtp_rx_cts(priv, skb, false);
1937 
1938 		if (j1939_tp_im_receiver(skcb))
1939 			j1939_xtp_rx_cts(priv, skb, true);
1940 
1941 		break;
1942 
1943 	case J1939_ETP_CMD_DPO:
1944 		if (skcb->addr.type != J1939_ETP)
1945 			return;
1946 
1947 		if (j1939_tp_im_transmitter(skcb))
1948 			j1939_xtp_rx_dpo(priv, skb, true);
1949 
1950 		if (j1939_tp_im_receiver(skcb))
1951 			j1939_xtp_rx_dpo(priv, skb, false);
1952 
1953 		break;
1954 
1955 	case J1939_ETP_CMD_EOMA:
1956 		extd = J1939_ETP;
1957 		/* fall through */
1958 	case J1939_TP_CMD_EOMA:
1959 		if (skcb->addr.type != extd)
1960 			return;
1961 
1962 		if (j1939_tp_im_transmitter(skcb))
1963 			j1939_xtp_rx_eoma(priv, skb, false);
1964 
1965 		if (j1939_tp_im_receiver(skcb))
1966 			j1939_xtp_rx_eoma(priv, skb, true);
1967 
1968 		break;
1969 
1970 	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
1971 		if (j1939_tp_im_transmitter(skcb))
1972 			j1939_xtp_rx_abort(priv, skb, true);
1973 
1974 		if (j1939_tp_im_receiver(skcb))
1975 			j1939_xtp_rx_abort(priv, skb, false);
1976 
1977 		break;
1978 	default:
1979 		return;
1980 	}
1981 }
1982 
1983 int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
1984 {
1985 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1986 
1987 	if (!j1939_tp_im_involved_anydir(skcb))
1988 		return 0;
1989 
1990 	switch (skcb->addr.pgn) {
1991 	case J1939_ETP_PGN_DAT:
1992 		skcb->addr.type = J1939_ETP;
1993 		/* fall through */
1994 	case J1939_TP_PGN_DAT:
1995 		j1939_xtp_rx_dat(priv, skb);
1996 		break;
1997 
1998 	case J1939_ETP_PGN_CTL:
1999 		skcb->addr.type = J1939_ETP;
2000 		/* fall through */
2001 	case J1939_TP_PGN_CTL:
2002 		if (skb->len < 8)
2003 			return 0; /* Don't care. Nothing to extract here */
2004 
2005 		j1939_tp_cmd_recv(priv, skb);
2006 		break;
2007 	default:
2008 		return 0; /* no problem */
2009 	}
2010 	return 1; /* "I processed the message" */
2011 }
2012 
2013 void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
2014 {
2015 	struct j1939_session *session;
2016 
2017 	if (!skb->sk)
2018 		return;
2019 
2020 	j1939_session_list_lock(priv);
2021 	session = j1939_session_get_simple(priv, skb);
2022 	j1939_session_list_unlock(priv);
2023 	if (!session) {
2024 		netdev_warn(priv->ndev,
2025 			    "%s: Received already invalidated message\n",
2026 			    __func__);
2027 		return;
2028 	}
2029 
2030 	j1939_session_timers_cancel(session);
2031 	j1939_session_deactivate(session);
2032 	j1939_session_put(session);
2033 }
2034 
2035 int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
2036 {
2037 	struct j1939_session *session, *saved;
2038 
2039 	netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
2040 	j1939_session_list_lock(priv);
2041 	list_for_each_entry_safe(session, saved,
2042 				 &priv->active_session_list,
2043 				 active_session_list_entry) {
2044 		if (!sk || sk == session->sk) {
2045 			if (hrtimer_try_to_cancel(&session->txtimer) == 1)
2046 				j1939_session_put(session);
2047 			if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
2048 				j1939_session_put(session);
2049 
2050 			session->err = ESHUTDOWN;
2051 			j1939_session_deactivate_locked(session);
2052 		}
2053 	}
2054 	j1939_session_list_unlock(priv);
2055 	return NOTIFY_DONE;
2056 }
2057 
2058 void j1939_tp_init(struct j1939_priv *priv)
2059 {
2060 	spin_lock_init(&priv->active_session_list_lock);
2061 	INIT_LIST_HEAD(&priv->active_session_list);
2062 	priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
2063 }
2064