xref: /openbmc/linux/net/can/j1939/transport.c (revision 11a163f2)
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
356 sk_buff *j1939_session_skb_find_by_offset(struct j1939_session *session,
357 					  unsigned int offset_start)
358 {
359 	struct j1939_priv *priv = session->priv;
360 	struct j1939_sk_buff_cb *do_skcb;
361 	struct sk_buff *skb = NULL;
362 	struct sk_buff *do_skb;
363 	unsigned long flags;
364 
365 	spin_lock_irqsave(&session->skb_queue.lock, flags);
366 	skb_queue_walk(&session->skb_queue, do_skb) {
367 		do_skcb = j1939_skb_to_cb(do_skb);
368 
369 		if (offset_start >= do_skcb->offset &&
370 		    offset_start < (do_skcb->offset + do_skb->len)) {
371 			skb = do_skb;
372 		}
373 	}
374 	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
375 
376 	if (!skb)
377 		netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
378 			   __func__, session, offset_start,
379 			   skb_queue_len(&session->skb_queue));
380 
381 	return skb;
382 }
383 
384 static struct sk_buff *j1939_session_skb_find(struct j1939_session *session)
385 {
386 	unsigned int offset_start;
387 
388 	offset_start = session->pkt.dpo * 7;
389 	return j1939_session_skb_find_by_offset(session, offset_start);
390 }
391 
392 /* see if we are receiver
393  * returns 0 for broadcasts, although we will receive them
394  */
395 static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
396 {
397 	return skcb->flags & J1939_ECU_LOCAL_DST;
398 }
399 
400 /* see if we are sender */
401 static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
402 {
403 	return skcb->flags & J1939_ECU_LOCAL_SRC;
404 }
405 
406 /* see if we are involved as either receiver or transmitter */
407 static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
408 {
409 	if (swap)
410 		return j1939_tp_im_receiver(skcb);
411 	else
412 		return j1939_tp_im_transmitter(skcb);
413 }
414 
415 static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
416 {
417 	return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
418 }
419 
420 /* extract pgn from flow-ctl message */
421 static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
422 {
423 	pgn_t pgn;
424 
425 	pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
426 	if (j1939_pgn_is_pdu1(pgn))
427 		pgn &= 0xffff00;
428 	return pgn;
429 }
430 
431 static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
432 {
433 	return (dat[2] << 8) + (dat[1] << 0);
434 }
435 
436 static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
437 {
438 	return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
439 }
440 
441 static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
442 {
443 	return (dat[4] << 24) | (dat[3] << 16) |
444 		(dat[2] << 8) | (dat[1] << 0);
445 }
446 
447 /* find existing session:
448  * reverse: swap cb's src & dst
449  * there is no problem with matching broadcasts, since
450  * broadcasts (no dst, no da) would never call this
451  * with reverse == true
452  */
453 static bool j1939_session_match(struct j1939_addr *se_addr,
454 				struct j1939_addr *sk_addr, bool reverse)
455 {
456 	if (se_addr->type != sk_addr->type)
457 		return false;
458 
459 	if (reverse) {
460 		if (se_addr->src_name) {
461 			if (se_addr->src_name != sk_addr->dst_name)
462 				return false;
463 		} else if (se_addr->sa != sk_addr->da) {
464 			return false;
465 		}
466 
467 		if (se_addr->dst_name) {
468 			if (se_addr->dst_name != sk_addr->src_name)
469 				return false;
470 		} else if (se_addr->da != sk_addr->sa) {
471 			return false;
472 		}
473 	} else {
474 		if (se_addr->src_name) {
475 			if (se_addr->src_name != sk_addr->src_name)
476 				return false;
477 		} else if (se_addr->sa != sk_addr->sa) {
478 			return false;
479 		}
480 
481 		if (se_addr->dst_name) {
482 			if (se_addr->dst_name != sk_addr->dst_name)
483 				return false;
484 		} else if (se_addr->da != sk_addr->da) {
485 			return false;
486 		}
487 	}
488 
489 	return true;
490 }
491 
492 static struct
493 j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
494 						struct list_head *root,
495 						struct j1939_addr *addr,
496 						bool reverse, bool transmitter)
497 {
498 	struct j1939_session *session;
499 
500 	lockdep_assert_held(&priv->active_session_list_lock);
501 
502 	list_for_each_entry(session, root, active_session_list_entry) {
503 		j1939_session_get(session);
504 		if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
505 		    session->transmission == transmitter)
506 			return session;
507 		j1939_session_put(session);
508 	}
509 
510 	return NULL;
511 }
512 
513 static struct
514 j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
515 					struct sk_buff *skb)
516 {
517 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
518 	struct j1939_session *session;
519 
520 	lockdep_assert_held(&priv->active_session_list_lock);
521 
522 	list_for_each_entry(session, &priv->active_session_list,
523 			    active_session_list_entry) {
524 		j1939_session_get(session);
525 		if (session->skcb.addr.type == J1939_SIMPLE &&
526 		    session->tskey == skcb->tskey && session->sk == skb->sk)
527 			return session;
528 		j1939_session_put(session);
529 	}
530 
531 	return NULL;
532 }
533 
534 static struct
535 j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
536 					 struct j1939_addr *addr,
537 					 bool reverse, bool transmitter)
538 {
539 	struct j1939_session *session;
540 
541 	j1939_session_list_lock(priv);
542 	session = j1939_session_get_by_addr_locked(priv,
543 						   &priv->active_session_list,
544 						   addr, reverse, transmitter);
545 	j1939_session_list_unlock(priv);
546 
547 	return session;
548 }
549 
550 static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
551 {
552 	u8 tmp = 0;
553 
554 	swap(skcb->addr.dst_name, skcb->addr.src_name);
555 	swap(skcb->addr.da, skcb->addr.sa);
556 
557 	/* swap SRC and DST flags, leave other untouched */
558 	if (skcb->flags & J1939_ECU_LOCAL_SRC)
559 		tmp |= J1939_ECU_LOCAL_DST;
560 	if (skcb->flags & J1939_ECU_LOCAL_DST)
561 		tmp |= J1939_ECU_LOCAL_SRC;
562 	skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
563 	skcb->flags |= tmp;
564 }
565 
566 static struct
567 sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
568 			     const struct j1939_sk_buff_cb *re_skcb,
569 			     bool ctl,
570 			     bool swap_src_dst)
571 {
572 	struct sk_buff *skb;
573 	struct j1939_sk_buff_cb *skcb;
574 
575 	skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
576 			GFP_ATOMIC);
577 	if (unlikely(!skb))
578 		return ERR_PTR(-ENOMEM);
579 
580 	skb->dev = priv->ndev;
581 	can_skb_reserve(skb);
582 	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
583 	can_skb_prv(skb)->skbcnt = 0;
584 	/* reserve CAN header */
585 	skb_reserve(skb, offsetof(struct can_frame, data));
586 
587 	memcpy(skb->cb, re_skcb, sizeof(skb->cb));
588 	skcb = j1939_skb_to_cb(skb);
589 	if (swap_src_dst)
590 		j1939_skbcb_swap(skcb);
591 
592 	if (ctl) {
593 		if (skcb->addr.type == J1939_ETP)
594 			skcb->addr.pgn = J1939_ETP_PGN_CTL;
595 		else
596 			skcb->addr.pgn = J1939_TP_PGN_CTL;
597 	} else {
598 		if (skcb->addr.type == J1939_ETP)
599 			skcb->addr.pgn = J1939_ETP_PGN_DAT;
600 		else
601 			skcb->addr.pgn = J1939_TP_PGN_DAT;
602 	}
603 
604 	return skb;
605 }
606 
607 /* TP transmit packet functions */
608 static int j1939_tp_tx_dat(struct j1939_session *session,
609 			   const u8 *dat, int len)
610 {
611 	struct j1939_priv *priv = session->priv;
612 	struct sk_buff *skb;
613 
614 	skb = j1939_tp_tx_dat_new(priv, &session->skcb,
615 				  false, false);
616 	if (IS_ERR(skb))
617 		return PTR_ERR(skb);
618 
619 	skb_put_data(skb, dat, len);
620 	if (j1939_tp_padding && len < 8)
621 		memset(skb_put(skb, 8 - len), 0xff, 8 - len);
622 
623 	return j1939_send_one(priv, skb);
624 }
625 
626 static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
627 			       const struct j1939_sk_buff_cb *re_skcb,
628 			       bool swap_src_dst, pgn_t pgn, const u8 *dat)
629 {
630 	struct sk_buff *skb;
631 	u8 *skdat;
632 
633 	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
634 		return 0;
635 
636 	skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
637 	if (IS_ERR(skb))
638 		return PTR_ERR(skb);
639 
640 	skdat = skb_put(skb, 8);
641 	memcpy(skdat, dat, 5);
642 	skdat[5] = (pgn >> 0);
643 	skdat[6] = (pgn >> 8);
644 	skdat[7] = (pgn >> 16);
645 
646 	return j1939_send_one(priv, skb);
647 }
648 
649 static inline int j1939_tp_tx_ctl(struct j1939_session *session,
650 				  bool swap_src_dst, const u8 *dat)
651 {
652 	struct j1939_priv *priv = session->priv;
653 
654 	return j1939_xtp_do_tx_ctl(priv, &session->skcb,
655 				   swap_src_dst,
656 				   session->skcb.addr.pgn, dat);
657 }
658 
659 static int j1939_xtp_tx_abort(struct j1939_priv *priv,
660 			      const struct j1939_sk_buff_cb *re_skcb,
661 			      bool swap_src_dst,
662 			      enum j1939_xtp_abort err,
663 			      pgn_t pgn)
664 {
665 	u8 dat[5];
666 
667 	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
668 		return 0;
669 
670 	memset(dat, 0xff, sizeof(dat));
671 	dat[0] = J1939_TP_CMD_ABORT;
672 	dat[1] = err;
673 	return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
674 }
675 
676 void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
677 {
678 	j1939_session_get(session);
679 	hrtimer_start(&session->txtimer, ms_to_ktime(msec),
680 		      HRTIMER_MODE_REL_SOFT);
681 }
682 
683 static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
684 					  int msec)
685 {
686 	j1939_session_rxtimer_cancel(session);
687 	j1939_session_get(session);
688 	hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
689 		      HRTIMER_MODE_REL_SOFT);
690 }
691 
692 static int j1939_session_tx_rts(struct j1939_session *session)
693 {
694 	u8 dat[8];
695 	int ret;
696 
697 	memset(dat, 0xff, sizeof(dat));
698 
699 	dat[1] = (session->total_message_size >> 0);
700 	dat[2] = (session->total_message_size >> 8);
701 	dat[3] = session->pkt.total;
702 
703 	if (session->skcb.addr.type == J1939_ETP) {
704 		dat[0] = J1939_ETP_CMD_RTS;
705 		dat[1] = (session->total_message_size >> 0);
706 		dat[2] = (session->total_message_size >> 8);
707 		dat[3] = (session->total_message_size >> 16);
708 		dat[4] = (session->total_message_size >> 24);
709 	} else if (j1939_cb_is_broadcast(&session->skcb)) {
710 		dat[0] = J1939_TP_CMD_BAM;
711 		/* fake cts for broadcast */
712 		session->pkt.tx = 0;
713 	} else {
714 		dat[0] = J1939_TP_CMD_RTS;
715 		dat[4] = dat[3];
716 	}
717 
718 	if (dat[0] == session->last_txcmd)
719 		/* done already */
720 		return 0;
721 
722 	ret = j1939_tp_tx_ctl(session, false, dat);
723 	if (ret < 0)
724 		return ret;
725 
726 	session->last_txcmd = dat[0];
727 	if (dat[0] == J1939_TP_CMD_BAM) {
728 		j1939_tp_schedule_txtimer(session, 50);
729 		j1939_tp_set_rxtimeout(session, 250);
730 	} else {
731 		j1939_tp_set_rxtimeout(session, 1250);
732 	}
733 
734 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
735 
736 	return 0;
737 }
738 
739 static int j1939_session_tx_dpo(struct j1939_session *session)
740 {
741 	unsigned int pkt;
742 	u8 dat[8];
743 	int ret;
744 
745 	memset(dat, 0xff, sizeof(dat));
746 
747 	dat[0] = J1939_ETP_CMD_DPO;
748 	session->pkt.dpo = session->pkt.tx_acked;
749 	pkt = session->pkt.dpo;
750 	dat[1] = session->pkt.last - session->pkt.tx_acked;
751 	dat[2] = (pkt >> 0);
752 	dat[3] = (pkt >> 8);
753 	dat[4] = (pkt >> 16);
754 
755 	ret = j1939_tp_tx_ctl(session, false, dat);
756 	if (ret < 0)
757 		return ret;
758 
759 	session->last_txcmd = dat[0];
760 	j1939_tp_set_rxtimeout(session, 1250);
761 	session->pkt.tx = session->pkt.tx_acked;
762 
763 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
764 
765 	return 0;
766 }
767 
768 static int j1939_session_tx_dat(struct j1939_session *session)
769 {
770 	struct j1939_priv *priv = session->priv;
771 	struct j1939_sk_buff_cb *skcb;
772 	int offset, pkt_done, pkt_end;
773 	unsigned int len, pdelay;
774 	struct sk_buff *se_skb;
775 	const u8 *tpdat;
776 	int ret = 0;
777 	u8 dat[8];
778 
779 	se_skb = j1939_session_skb_find_by_offset(session, session->pkt.tx * 7);
780 	if (!se_skb)
781 		return -ENOBUFS;
782 
783 	skcb = j1939_skb_to_cb(se_skb);
784 	tpdat = se_skb->data;
785 	ret = 0;
786 	pkt_done = 0;
787 	if (session->skcb.addr.type != J1939_ETP &&
788 	    j1939_cb_is_broadcast(&session->skcb))
789 		pkt_end = session->pkt.total;
790 	else
791 		pkt_end = session->pkt.last;
792 
793 	while (session->pkt.tx < pkt_end) {
794 		dat[0] = session->pkt.tx - session->pkt.dpo + 1;
795 		offset = (session->pkt.tx * 7) - skcb->offset;
796 		len =  se_skb->len - offset;
797 		if (len > 7)
798 			len = 7;
799 
800 		if (offset + len > se_skb->len) {
801 			netdev_err_once(priv->ndev,
802 					"%s: 0x%p: requested data outside of queued buffer: offset %i, len %i, pkt.tx: %i\n",
803 					__func__, session, skcb->offset, se_skb->len , session->pkt.tx);
804 			return -EOVERFLOW;
805 		}
806 
807 		if (!len) {
808 			ret = -ENOBUFS;
809 			break;
810 		}
811 
812 		memcpy(&dat[1], &tpdat[offset], len);
813 		ret = j1939_tp_tx_dat(session, dat, len + 1);
814 		if (ret < 0) {
815 			/* ENOBUS == CAN interface TX queue is full */
816 			if (ret != -ENOBUFS)
817 				netdev_alert(priv->ndev,
818 					     "%s: 0x%p: queue data error: %i\n",
819 					     __func__, session, ret);
820 			break;
821 		}
822 
823 		session->last_txcmd = 0xff;
824 		pkt_done++;
825 		session->pkt.tx++;
826 		pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
827 			j1939_tp_packet_delay;
828 
829 		if (session->pkt.tx < session->pkt.total && pdelay) {
830 			j1939_tp_schedule_txtimer(session, pdelay);
831 			break;
832 		}
833 	}
834 
835 	if (pkt_done)
836 		j1939_tp_set_rxtimeout(session, 250);
837 
838 	return ret;
839 }
840 
841 static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
842 {
843 	struct j1939_priv *priv = session->priv;
844 	int ret = 0;
845 
846 	if (!j1939_tp_im_transmitter(&session->skcb)) {
847 		netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
848 			     __func__, session);
849 		return -EINVAL;
850 	}
851 
852 	switch (session->last_cmd) {
853 	case 0:
854 		ret = j1939_session_tx_rts(session);
855 		break;
856 
857 	case J1939_ETP_CMD_CTS:
858 		if (session->last_txcmd != J1939_ETP_CMD_DPO) {
859 			ret = j1939_session_tx_dpo(session);
860 			if (ret)
861 				return ret;
862 		}
863 
864 		fallthrough;
865 	case J1939_TP_CMD_CTS:
866 	case 0xff: /* did some data */
867 	case J1939_ETP_CMD_DPO:
868 	case J1939_TP_CMD_BAM:
869 		ret = j1939_session_tx_dat(session);
870 
871 		break;
872 	default:
873 		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
874 			     __func__, session, session->last_cmd);
875 	}
876 
877 	return ret;
878 }
879 
880 static int j1939_session_tx_cts(struct j1939_session *session)
881 {
882 	struct j1939_priv *priv = session->priv;
883 	unsigned int pkt, len;
884 	int ret;
885 	u8 dat[8];
886 
887 	if (!j1939_sk_recv_match(priv, &session->skcb))
888 		return -ENOENT;
889 
890 	len = session->pkt.total - session->pkt.rx;
891 	len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
892 	memset(dat, 0xff, sizeof(dat));
893 
894 	if (session->skcb.addr.type == J1939_ETP) {
895 		pkt = session->pkt.rx + 1;
896 		dat[0] = J1939_ETP_CMD_CTS;
897 		dat[1] = len;
898 		dat[2] = (pkt >> 0);
899 		dat[3] = (pkt >> 8);
900 		dat[4] = (pkt >> 16);
901 	} else {
902 		dat[0] = J1939_TP_CMD_CTS;
903 		dat[1] = len;
904 		dat[2] = session->pkt.rx + 1;
905 	}
906 
907 	if (dat[0] == session->last_txcmd)
908 		/* done already */
909 		return 0;
910 
911 	ret = j1939_tp_tx_ctl(session, true, dat);
912 	if (ret < 0)
913 		return ret;
914 
915 	if (len)
916 		/* only mark cts done when len is set */
917 		session->last_txcmd = dat[0];
918 	j1939_tp_set_rxtimeout(session, 1250);
919 
920 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
921 
922 	return 0;
923 }
924 
925 static int j1939_session_tx_eoma(struct j1939_session *session)
926 {
927 	struct j1939_priv *priv = session->priv;
928 	u8 dat[8];
929 	int ret;
930 
931 	if (!j1939_sk_recv_match(priv, &session->skcb))
932 		return -ENOENT;
933 
934 	memset(dat, 0xff, sizeof(dat));
935 
936 	if (session->skcb.addr.type == J1939_ETP) {
937 		dat[0] = J1939_ETP_CMD_EOMA;
938 		dat[1] = session->total_message_size >> 0;
939 		dat[2] = session->total_message_size >> 8;
940 		dat[3] = session->total_message_size >> 16;
941 		dat[4] = session->total_message_size >> 24;
942 	} else {
943 		dat[0] = J1939_TP_CMD_EOMA;
944 		dat[1] = session->total_message_size;
945 		dat[2] = session->total_message_size >> 8;
946 		dat[3] = session->pkt.total;
947 	}
948 
949 	if (dat[0] == session->last_txcmd)
950 		/* done already */
951 		return 0;
952 
953 	ret = j1939_tp_tx_ctl(session, true, dat);
954 	if (ret < 0)
955 		return ret;
956 
957 	session->last_txcmd = dat[0];
958 
959 	/* wait for the EOMA packet to come in */
960 	j1939_tp_set_rxtimeout(session, 1250);
961 
962 	netdev_dbg(session->priv->ndev, "%p: 0x%p\n", __func__, session);
963 
964 	return 0;
965 }
966 
967 static int j1939_xtp_txnext_receiver(struct j1939_session *session)
968 {
969 	struct j1939_priv *priv = session->priv;
970 	int ret = 0;
971 
972 	if (!j1939_tp_im_receiver(&session->skcb)) {
973 		netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
974 			     __func__, session);
975 		return -EINVAL;
976 	}
977 
978 	switch (session->last_cmd) {
979 	case J1939_TP_CMD_RTS:
980 	case J1939_ETP_CMD_RTS:
981 		ret = j1939_session_tx_cts(session);
982 		break;
983 
984 	case J1939_ETP_CMD_CTS:
985 	case J1939_TP_CMD_CTS:
986 	case 0xff: /* did some data */
987 	case J1939_ETP_CMD_DPO:
988 		if ((session->skcb.addr.type == J1939_TP &&
989 		     j1939_cb_is_broadcast(&session->skcb)))
990 			break;
991 
992 		if (session->pkt.rx >= session->pkt.total) {
993 			ret = j1939_session_tx_eoma(session);
994 		} else if (session->pkt.rx >= session->pkt.last) {
995 			session->last_txcmd = 0;
996 			ret = j1939_session_tx_cts(session);
997 		}
998 		break;
999 	default:
1000 		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
1001 			     __func__, session, session->last_cmd);
1002 	}
1003 
1004 	return ret;
1005 }
1006 
1007 static int j1939_simple_txnext(struct j1939_session *session)
1008 {
1009 	struct j1939_priv *priv = session->priv;
1010 	struct sk_buff *se_skb = j1939_session_skb_find(session);
1011 	struct sk_buff *skb;
1012 	int ret;
1013 
1014 	if (!se_skb)
1015 		return 0;
1016 
1017 	skb = skb_clone(se_skb, GFP_ATOMIC);
1018 	if (!skb)
1019 		return -ENOMEM;
1020 
1021 	can_skb_set_owner(skb, se_skb->sk);
1022 
1023 	j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
1024 
1025 	ret = j1939_send_one(priv, skb);
1026 	if (ret)
1027 		return ret;
1028 
1029 	j1939_sk_errqueue(session, J1939_ERRQUEUE_SCHED);
1030 	j1939_sk_queue_activate_next(session);
1031 
1032 	return 0;
1033 }
1034 
1035 static bool j1939_session_deactivate_locked(struct j1939_session *session)
1036 {
1037 	bool active = false;
1038 
1039 	lockdep_assert_held(&session->priv->active_session_list_lock);
1040 
1041 	if (session->state >= J1939_SESSION_ACTIVE &&
1042 	    session->state < J1939_SESSION_ACTIVE_MAX) {
1043 		active = true;
1044 
1045 		list_del_init(&session->active_session_list_entry);
1046 		session->state = J1939_SESSION_DONE;
1047 		j1939_session_put(session);
1048 	}
1049 
1050 	return active;
1051 }
1052 
1053 static bool j1939_session_deactivate(struct j1939_session *session)
1054 {
1055 	bool active;
1056 
1057 	j1939_session_list_lock(session->priv);
1058 	active = j1939_session_deactivate_locked(session);
1059 	j1939_session_list_unlock(session->priv);
1060 
1061 	return active;
1062 }
1063 
1064 static void
1065 j1939_session_deactivate_activate_next(struct j1939_session *session)
1066 {
1067 	if (j1939_session_deactivate(session))
1068 		j1939_sk_queue_activate_next(session);
1069 }
1070 
1071 static void __j1939_session_cancel(struct j1939_session *session,
1072 				 enum j1939_xtp_abort err)
1073 {
1074 	struct j1939_priv *priv = session->priv;
1075 
1076 	WARN_ON_ONCE(!err);
1077 	lockdep_assert_held(&session->priv->active_session_list_lock);
1078 
1079 	session->err = j1939_xtp_abort_to_errno(priv, err);
1080 	session->state = J1939_SESSION_WAITING_ABORT;
1081 	/* do not send aborts on incoming broadcasts */
1082 	if (!j1939_cb_is_broadcast(&session->skcb)) {
1083 		j1939_xtp_tx_abort(priv, &session->skcb,
1084 				   !session->transmission,
1085 				   err, session->skcb.addr.pgn);
1086 	}
1087 
1088 	if (session->sk)
1089 		j1939_sk_send_loop_abort(session->sk, session->err);
1090 }
1091 
1092 static void j1939_session_cancel(struct j1939_session *session,
1093 				 enum j1939_xtp_abort err)
1094 {
1095 	j1939_session_list_lock(session->priv);
1096 
1097 	if (session->state >= J1939_SESSION_ACTIVE &&
1098 	    session->state < J1939_SESSION_WAITING_ABORT) {
1099 		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
1100 		__j1939_session_cancel(session, err);
1101 	}
1102 
1103 	j1939_session_list_unlock(session->priv);
1104 }
1105 
1106 static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
1107 {
1108 	struct j1939_session *session =
1109 		container_of(hrtimer, struct j1939_session, txtimer);
1110 	struct j1939_priv *priv = session->priv;
1111 	int ret = 0;
1112 
1113 	if (session->skcb.addr.type == J1939_SIMPLE) {
1114 		ret = j1939_simple_txnext(session);
1115 	} else {
1116 		if (session->transmission)
1117 			ret = j1939_xtp_txnext_transmiter(session);
1118 		else
1119 			ret = j1939_xtp_txnext_receiver(session);
1120 	}
1121 
1122 	switch (ret) {
1123 	case -ENOBUFS:
1124 		/* Retry limit is currently arbitrary chosen */
1125 		if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
1126 			session->tx_retry++;
1127 			j1939_tp_schedule_txtimer(session,
1128 						  10 + prandom_u32_max(16));
1129 		} else {
1130 			netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
1131 				     __func__, session);
1132 			session->err = -ENETUNREACH;
1133 			j1939_session_rxtimer_cancel(session);
1134 			j1939_session_deactivate_activate_next(session);
1135 		}
1136 		break;
1137 	case -ENETDOWN:
1138 		/* In this case we should get a netdev_event(), all active
1139 		 * sessions will be cleared by
1140 		 * j1939_cancel_all_active_sessions(). So handle this as an
1141 		 * error, but let j1939_cancel_all_active_sessions() do the
1142 		 * cleanup including propagation of the error to user space.
1143 		 */
1144 		break;
1145 	case -EOVERFLOW:
1146 		j1939_session_cancel(session, J1939_XTP_ABORT_ECTS_TOO_BIG);
1147 		break;
1148 	case 0:
1149 		session->tx_retry = 0;
1150 		break;
1151 	default:
1152 		netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
1153 			     __func__, session, ret);
1154 		if (session->skcb.addr.type != J1939_SIMPLE) {
1155 			j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
1156 		} else {
1157 			session->err = ret;
1158 			j1939_session_rxtimer_cancel(session);
1159 			j1939_session_deactivate_activate_next(session);
1160 		}
1161 	}
1162 
1163 	j1939_session_put(session);
1164 
1165 	return HRTIMER_NORESTART;
1166 }
1167 
1168 static void j1939_session_completed(struct j1939_session *session)
1169 {
1170 	struct sk_buff *skb;
1171 
1172 	if (!session->transmission) {
1173 		skb = j1939_session_skb_find(session);
1174 		/* distribute among j1939 receivers */
1175 		j1939_sk_recv(session->priv, skb);
1176 	}
1177 
1178 	j1939_session_deactivate_activate_next(session);
1179 }
1180 
1181 static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
1182 {
1183 	struct j1939_session *session = container_of(hrtimer,
1184 						     struct j1939_session,
1185 						     rxtimer);
1186 	struct j1939_priv *priv = session->priv;
1187 
1188 	if (session->state == J1939_SESSION_WAITING_ABORT) {
1189 		netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
1190 			     __func__, session);
1191 
1192 		j1939_session_deactivate_activate_next(session);
1193 
1194 	} else if (session->skcb.addr.type == J1939_SIMPLE) {
1195 		netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
1196 			     __func__, session);
1197 
1198 		/* The message is probably stuck in the CAN controller and can
1199 		 * be send as soon as CAN bus is in working state again.
1200 		 */
1201 		session->err = -ETIME;
1202 		j1939_session_deactivate(session);
1203 	} else {
1204 		netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
1205 			     __func__, session);
1206 
1207 		j1939_session_list_lock(session->priv);
1208 		if (session->state >= J1939_SESSION_ACTIVE &&
1209 		    session->state < J1939_SESSION_ACTIVE_MAX) {
1210 			j1939_session_get(session);
1211 			hrtimer_start(&session->rxtimer,
1212 				      ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
1213 				      HRTIMER_MODE_REL_SOFT);
1214 			__j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
1215 		}
1216 		j1939_session_list_unlock(session->priv);
1217 	}
1218 
1219 	j1939_session_put(session);
1220 
1221 	return HRTIMER_NORESTART;
1222 }
1223 
1224 static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
1225 				     const struct sk_buff *skb)
1226 {
1227 	const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1228 	pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
1229 	struct j1939_priv *priv = session->priv;
1230 	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1231 	u8 cmd = skb->data[0];
1232 
1233 	if (session->skcb.addr.pgn == pgn)
1234 		return false;
1235 
1236 	switch (cmd) {
1237 	case J1939_TP_CMD_BAM:
1238 		abort = J1939_XTP_NO_ABORT;
1239 		break;
1240 
1241 	case J1939_ETP_CMD_RTS:
1242 	case J1939_TP_CMD_RTS: /* fall through */
1243 		abort = J1939_XTP_ABORT_BUSY;
1244 		break;
1245 
1246 	case J1939_ETP_CMD_CTS:
1247 	case J1939_TP_CMD_CTS: /* fall through */
1248 		abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
1249 		break;
1250 
1251 	case J1939_ETP_CMD_DPO:
1252 		abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
1253 		break;
1254 
1255 	case J1939_ETP_CMD_EOMA:
1256 	case J1939_TP_CMD_EOMA: /* fall through */
1257 		abort = J1939_XTP_ABORT_OTHER;
1258 		break;
1259 
1260 	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
1261 		abort = J1939_XTP_NO_ABORT;
1262 		break;
1263 
1264 	default:
1265 		WARN_ON_ONCE(1);
1266 		break;
1267 	}
1268 
1269 	netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
1270 		    __func__, session, cmd, pgn, session->skcb.addr.pgn);
1271 	if (abort != J1939_XTP_NO_ABORT)
1272 		j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
1273 
1274 	return true;
1275 }
1276 
1277 static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
1278 				   bool reverse, bool transmitter)
1279 {
1280 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1281 	struct j1939_session *session;
1282 	u8 abort = skb->data[1];
1283 
1284 	session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
1285 					    transmitter);
1286 	if (!session)
1287 		return;
1288 
1289 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1290 		goto abort_put;
1291 
1292 	netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
1293 		    session, j1939_xtp_ctl_to_pgn(skb->data), abort,
1294 		    j1939_xtp_abort_to_str(abort));
1295 
1296 	j1939_session_timers_cancel(session);
1297 	session->err = j1939_xtp_abort_to_errno(priv, abort);
1298 	if (session->sk)
1299 		j1939_sk_send_loop_abort(session->sk, session->err);
1300 	j1939_session_deactivate_activate_next(session);
1301 
1302 abort_put:
1303 	j1939_session_put(session);
1304 }
1305 
1306 /* abort packets may come in 2 directions */
1307 static void
1308 j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
1309 		   bool transmitter)
1310 {
1311 	j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
1312 	j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
1313 }
1314 
1315 static void
1316 j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
1317 {
1318 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1319 	const u8 *dat;
1320 	int len;
1321 
1322 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1323 		return;
1324 
1325 	dat = skb->data;
1326 
1327 	if (skcb->addr.type == J1939_ETP)
1328 		len = j1939_etp_ctl_to_size(dat);
1329 	else
1330 		len = j1939_tp_ctl_to_size(dat);
1331 
1332 	if (session->total_message_size != len) {
1333 		netdev_warn_once(session->priv->ndev,
1334 				 "%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
1335 				 __func__, session, session->total_message_size,
1336 				 len);
1337 	}
1338 
1339 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1340 
1341 	session->pkt.tx_acked = session->pkt.total;
1342 	j1939_session_timers_cancel(session);
1343 	/* transmitted without problems */
1344 	j1939_session_completed(session);
1345 }
1346 
1347 static void
1348 j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
1349 		  bool transmitter)
1350 {
1351 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1352 	struct j1939_session *session;
1353 
1354 	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1355 					    transmitter);
1356 	if (!session)
1357 		return;
1358 
1359 	j1939_xtp_rx_eoma_one(session, skb);
1360 	j1939_session_put(session);
1361 }
1362 
1363 static void
1364 j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
1365 {
1366 	enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
1367 	unsigned int pkt;
1368 	const u8 *dat;
1369 
1370 	dat = skb->data;
1371 
1372 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1373 		return;
1374 
1375 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1376 
1377 	if (session->last_cmd == dat[0]) {
1378 		err = J1939_XTP_ABORT_DUP_SEQ;
1379 		goto out_session_cancel;
1380 	}
1381 
1382 	if (session->skcb.addr.type == J1939_ETP)
1383 		pkt = j1939_etp_ctl_to_packet(dat);
1384 	else
1385 		pkt = dat[2];
1386 
1387 	if (!pkt)
1388 		goto out_session_cancel;
1389 	else if (dat[1] > session->pkt.block /* 0xff for etp */)
1390 		goto out_session_cancel;
1391 
1392 	/* set packet counters only when not CTS(0) */
1393 	session->pkt.tx_acked = pkt - 1;
1394 	j1939_session_skb_drop_old(session);
1395 	session->pkt.last = session->pkt.tx_acked + dat[1];
1396 	if (session->pkt.last > session->pkt.total)
1397 		/* safety measure */
1398 		session->pkt.last = session->pkt.total;
1399 	/* TODO: do not set tx here, do it in txtimer */
1400 	session->pkt.tx = session->pkt.tx_acked;
1401 
1402 	session->last_cmd = dat[0];
1403 	if (dat[1]) {
1404 		j1939_tp_set_rxtimeout(session, 1250);
1405 		if (session->transmission) {
1406 			if (session->pkt.tx_acked)
1407 				j1939_sk_errqueue(session,
1408 						  J1939_ERRQUEUE_SCHED);
1409 			j1939_session_txtimer_cancel(session);
1410 			j1939_tp_schedule_txtimer(session, 0);
1411 		}
1412 	} else {
1413 		/* CTS(0) */
1414 		j1939_tp_set_rxtimeout(session, 550);
1415 	}
1416 	return;
1417 
1418  out_session_cancel:
1419 	j1939_session_timers_cancel(session);
1420 	j1939_session_cancel(session, err);
1421 }
1422 
1423 static void
1424 j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
1425 {
1426 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1427 	struct j1939_session *session;
1428 
1429 	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1430 					    transmitter);
1431 	if (!session)
1432 		return;
1433 	j1939_xtp_rx_cts_one(session, skb);
1434 	j1939_session_put(session);
1435 }
1436 
1437 static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
1438 					       struct sk_buff *skb, size_t size)
1439 {
1440 	struct j1939_session *session;
1441 	struct j1939_sk_buff_cb *skcb;
1442 
1443 	session = kzalloc(sizeof(*session), gfp_any());
1444 	if (!session)
1445 		return NULL;
1446 
1447 	INIT_LIST_HEAD(&session->active_session_list_entry);
1448 	INIT_LIST_HEAD(&session->sk_session_queue_entry);
1449 	kref_init(&session->kref);
1450 
1451 	j1939_priv_get(priv);
1452 	session->priv = priv;
1453 	session->total_message_size = size;
1454 	session->state = J1939_SESSION_NEW;
1455 
1456 	skb_queue_head_init(&session->skb_queue);
1457 	skb_queue_tail(&session->skb_queue, skb);
1458 
1459 	skcb = j1939_skb_to_cb(skb);
1460 	memcpy(&session->skcb, skcb, sizeof(session->skcb));
1461 
1462 	hrtimer_init(&session->txtimer, CLOCK_MONOTONIC,
1463 		     HRTIMER_MODE_REL_SOFT);
1464 	session->txtimer.function = j1939_tp_txtimer;
1465 	hrtimer_init(&session->rxtimer, CLOCK_MONOTONIC,
1466 		     HRTIMER_MODE_REL_SOFT);
1467 	session->rxtimer.function = j1939_tp_rxtimer;
1468 
1469 	netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
1470 		   __func__, session, skcb->addr.sa, skcb->addr.da);
1471 
1472 	return session;
1473 }
1474 
1475 static struct
1476 j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
1477 				       int size,
1478 				       const struct j1939_sk_buff_cb *rel_skcb)
1479 {
1480 	struct sk_buff *skb;
1481 	struct j1939_sk_buff_cb *skcb;
1482 	struct j1939_session *session;
1483 
1484 	skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
1485 	if (unlikely(!skb))
1486 		return NULL;
1487 
1488 	skb->dev = priv->ndev;
1489 	can_skb_reserve(skb);
1490 	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
1491 	can_skb_prv(skb)->skbcnt = 0;
1492 	skcb = j1939_skb_to_cb(skb);
1493 	memcpy(skcb, rel_skcb, sizeof(*skcb));
1494 
1495 	session = j1939_session_new(priv, skb, size);
1496 	if (!session) {
1497 		kfree_skb(skb);
1498 		return NULL;
1499 	}
1500 
1501 	/* alloc data area */
1502 	skb_put(skb, size);
1503 	/* skb is recounted in j1939_session_new() */
1504 	return session;
1505 }
1506 
1507 int j1939_session_activate(struct j1939_session *session)
1508 {
1509 	struct j1939_priv *priv = session->priv;
1510 	struct j1939_session *active = NULL;
1511 	int ret = 0;
1512 
1513 	j1939_session_list_lock(priv);
1514 	if (session->skcb.addr.type != J1939_SIMPLE)
1515 		active = j1939_session_get_by_addr_locked(priv,
1516 							  &priv->active_session_list,
1517 							  &session->skcb.addr, false,
1518 							  session->transmission);
1519 	if (active) {
1520 		j1939_session_put(active);
1521 		ret = -EAGAIN;
1522 	} else {
1523 		WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
1524 		list_add_tail(&session->active_session_list_entry,
1525 			      &priv->active_session_list);
1526 		j1939_session_get(session);
1527 		session->state = J1939_SESSION_ACTIVE;
1528 
1529 		netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
1530 			   __func__, session);
1531 	}
1532 	j1939_session_list_unlock(priv);
1533 
1534 	return ret;
1535 }
1536 
1537 static struct
1538 j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
1539 					    struct sk_buff *skb)
1540 {
1541 	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1542 	struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
1543 	struct j1939_session *session;
1544 	const u8 *dat;
1545 	pgn_t pgn;
1546 	int len;
1547 
1548 	netdev_dbg(priv->ndev, "%s\n", __func__);
1549 
1550 	dat = skb->data;
1551 	pgn = j1939_xtp_ctl_to_pgn(dat);
1552 	skcb.addr.pgn = pgn;
1553 
1554 	if (!j1939_sk_recv_match(priv, &skcb))
1555 		return NULL;
1556 
1557 	if (skcb.addr.type == J1939_ETP) {
1558 		len = j1939_etp_ctl_to_size(dat);
1559 		if (len > J1939_MAX_ETP_PACKET_SIZE)
1560 			abort = J1939_XTP_ABORT_FAULT;
1561 		else if (len > priv->tp_max_packet_size)
1562 			abort = J1939_XTP_ABORT_RESOURCE;
1563 		else if (len <= J1939_MAX_TP_PACKET_SIZE)
1564 			abort = J1939_XTP_ABORT_FAULT;
1565 	} else {
1566 		len = j1939_tp_ctl_to_size(dat);
1567 		if (len > J1939_MAX_TP_PACKET_SIZE)
1568 			abort = J1939_XTP_ABORT_FAULT;
1569 		else if (len > priv->tp_max_packet_size)
1570 			abort = J1939_XTP_ABORT_RESOURCE;
1571 	}
1572 
1573 	if (abort != J1939_XTP_NO_ABORT) {
1574 		j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
1575 		return NULL;
1576 	}
1577 
1578 	session = j1939_session_fresh_new(priv, len, &skcb);
1579 	if (!session) {
1580 		j1939_xtp_tx_abort(priv, &skcb, true,
1581 				   J1939_XTP_ABORT_RESOURCE, pgn);
1582 		return NULL;
1583 	}
1584 
1585 	/* initialize the control buffer: plain copy */
1586 	session->pkt.total = (len + 6) / 7;
1587 	session->pkt.block = 0xff;
1588 	if (skcb.addr.type != J1939_ETP) {
1589 		if (dat[3] != session->pkt.total)
1590 			netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
1591 				     __func__, session, session->pkt.total,
1592 				     dat[3]);
1593 		session->pkt.total = dat[3];
1594 		session->pkt.block = min(dat[3], dat[4]);
1595 	}
1596 
1597 	session->pkt.rx = 0;
1598 	session->pkt.tx = 0;
1599 
1600 	WARN_ON_ONCE(j1939_session_activate(session));
1601 
1602 	return session;
1603 }
1604 
1605 static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
1606 					   struct sk_buff *skb)
1607 {
1608 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1609 	struct j1939_priv *priv = session->priv;
1610 
1611 	if (!session->transmission) {
1612 		if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1613 			return -EBUSY;
1614 
1615 		/* RTS on active session */
1616 		j1939_session_timers_cancel(session);
1617 		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1618 	}
1619 
1620 	if (session->last_cmd != 0) {
1621 		/* we received a second rts on the same connection */
1622 		netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
1623 			     __func__, session, skcb->addr.sa, skcb->addr.da,
1624 			     session->last_cmd);
1625 
1626 		j1939_session_timers_cancel(session);
1627 		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1628 
1629 		return -EBUSY;
1630 	}
1631 
1632 	if (session->skcb.addr.sa != skcb->addr.sa ||
1633 	    session->skcb.addr.da != skcb->addr.da)
1634 		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",
1635 			    __func__, session,
1636 			    session->skcb.addr.sa, skcb->addr.sa,
1637 			    session->skcb.addr.da, skcb->addr.da);
1638 	/* make sure 'sa' & 'da' are correct !
1639 	 * They may be 'not filled in yet' for sending
1640 	 * skb's, since they did not pass the Address Claim ever.
1641 	 */
1642 	session->skcb.addr.sa = skcb->addr.sa;
1643 	session->skcb.addr.da = skcb->addr.da;
1644 
1645 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1646 
1647 	return 0;
1648 }
1649 
1650 static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
1651 			     bool transmitter)
1652 {
1653 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1654 	struct j1939_session *session;
1655 	u8 cmd = skb->data[0];
1656 
1657 	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1658 					    transmitter);
1659 
1660 	if (!session) {
1661 		if (transmitter) {
1662 			/* If we're the transmitter and this function is called,
1663 			 * we received our own RTS. A session has already been
1664 			 * created.
1665 			 *
1666 			 * For some reasons however it might have been destroyed
1667 			 * already. So don't create a new one here (using
1668 			 * "j1939_xtp_rx_rts_session_new()") as this will be a
1669 			 * receiver session.
1670 			 *
1671 			 * The reasons the session is already destroyed might
1672 			 * be:
1673 			 * - user space closed socket was and the session was
1674 			 *   aborted
1675 			 * - session was aborted due to external abort message
1676 			 */
1677 			return;
1678 		}
1679 		session = j1939_xtp_rx_rts_session_new(priv, skb);
1680 		if (!session) {
1681 			if (cmd == J1939_TP_CMD_BAM && j1939_sk_recv_match(priv, skcb))
1682 				netdev_info(priv->ndev, "%s: failed to create TP BAM session\n",
1683 					    __func__);
1684 			return;
1685 		}
1686 	} else {
1687 		if (j1939_xtp_rx_rts_session_active(session, skb)) {
1688 			j1939_session_put(session);
1689 			return;
1690 		}
1691 	}
1692 	session->last_cmd = cmd;
1693 
1694 	if (cmd == J1939_TP_CMD_BAM) {
1695 		if (!session->transmission)
1696 			j1939_tp_set_rxtimeout(session, 750);
1697 	} else {
1698 		if (!session->transmission) {
1699 			j1939_session_txtimer_cancel(session);
1700 			j1939_tp_schedule_txtimer(session, 0);
1701 		}
1702 		j1939_tp_set_rxtimeout(session, 1250);
1703 	}
1704 
1705 	j1939_session_put(session);
1706 }
1707 
1708 static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
1709 				 struct sk_buff *skb)
1710 {
1711 	const u8 *dat = skb->data;
1712 
1713 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1714 		return;
1715 
1716 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1717 
1718 	/* transmitted without problems */
1719 	session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
1720 	session->last_cmd = dat[0];
1721 	j1939_tp_set_rxtimeout(session, 750);
1722 }
1723 
1724 static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
1725 			     bool transmitter)
1726 {
1727 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1728 	struct j1939_session *session;
1729 
1730 	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1731 					    transmitter);
1732 	if (!session) {
1733 		netdev_info(priv->ndev,
1734 			    "%s: no connection found\n", __func__);
1735 		return;
1736 	}
1737 
1738 	j1939_xtp_rx_dpo_one(session, skb);
1739 	j1939_session_put(session);
1740 }
1741 
1742 static void j1939_xtp_rx_dat_one(struct j1939_session *session,
1743 				 struct sk_buff *skb)
1744 {
1745 	struct j1939_priv *priv = session->priv;
1746 	struct j1939_sk_buff_cb *skcb;
1747 	struct sk_buff *se_skb;
1748 	const u8 *dat;
1749 	u8 *tpdat;
1750 	int offset;
1751 	int nbytes;
1752 	bool final = false;
1753 	bool remain = false;
1754 	bool do_cts_eoma = false;
1755 	int packet;
1756 
1757 	skcb = j1939_skb_to_cb(skb);
1758 	dat = skb->data;
1759 	if (skb->len <= 1)
1760 		/* makes no sense */
1761 		goto out_session_cancel;
1762 
1763 	switch (session->last_cmd) {
1764 	case 0xff:
1765 		break;
1766 	case J1939_ETP_CMD_DPO:
1767 		if (skcb->addr.type == J1939_ETP)
1768 			break;
1769 		fallthrough;
1770 	case J1939_TP_CMD_BAM:
1771 	case J1939_TP_CMD_CTS: /* fall through */
1772 		if (skcb->addr.type != J1939_ETP)
1773 			break;
1774 		fallthrough;
1775 	default:
1776 		netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
1777 			    session, session->last_cmd);
1778 		goto out_session_cancel;
1779 	}
1780 
1781 	packet = (dat[0] - 1 + session->pkt.dpo);
1782 	if (packet > session->pkt.total ||
1783 	    (session->pkt.rx + 1) > session->pkt.total) {
1784 		netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
1785 			    __func__, session);
1786 		goto out_session_cancel;
1787 	}
1788 
1789 	se_skb = j1939_session_skb_find_by_offset(session, packet * 7);
1790 	if (!se_skb) {
1791 		netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
1792 			    session);
1793 		goto out_session_cancel;
1794 	}
1795 
1796 	skcb = j1939_skb_to_cb(se_skb);
1797 	offset = packet * 7 - skcb->offset;
1798 	nbytes = se_skb->len - offset;
1799 	if (nbytes > 7)
1800 		nbytes = 7;
1801 	if (nbytes <= 0 || (nbytes + 1) > skb->len) {
1802 		netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
1803 			    __func__, session, nbytes, skb->len);
1804 		goto out_session_cancel;
1805 	}
1806 
1807 	tpdat = se_skb->data;
1808 	if (!session->transmission) {
1809 		memcpy(&tpdat[offset], &dat[1], nbytes);
1810 	} else {
1811 		int err;
1812 
1813 		err = memcmp(&tpdat[offset], &dat[1], nbytes);
1814 		if (err)
1815 			netdev_err_once(priv->ndev,
1816 					"%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n",
1817 					__func__, session,
1818 					nbytes, &dat[1],
1819 					nbytes, &tpdat[offset]);
1820 	}
1821 
1822 	if (packet == session->pkt.rx)
1823 		session->pkt.rx++;
1824 
1825 	if (skcb->addr.type != J1939_ETP &&
1826 	    j1939_cb_is_broadcast(&session->skcb)) {
1827 		if (session->pkt.rx >= session->pkt.total)
1828 			final = true;
1829 		else
1830 			remain = true;
1831 	} else {
1832 		/* never final, an EOMA must follow */
1833 		if (session->pkt.rx >= session->pkt.last)
1834 			do_cts_eoma = true;
1835 	}
1836 
1837 	if (final) {
1838 		j1939_session_timers_cancel(session);
1839 		j1939_session_completed(session);
1840 	} else if (remain) {
1841 		if (!session->transmission)
1842 			j1939_tp_set_rxtimeout(session, 750);
1843 	} else if (do_cts_eoma) {
1844 		j1939_tp_set_rxtimeout(session, 1250);
1845 		if (!session->transmission)
1846 			j1939_tp_schedule_txtimer(session, 0);
1847 	} else {
1848 		j1939_tp_set_rxtimeout(session, 250);
1849 	}
1850 	session->last_cmd = 0xff;
1851 	j1939_session_put(session);
1852 
1853 	return;
1854 
1855  out_session_cancel:
1856 	j1939_session_timers_cancel(session);
1857 	j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
1858 	j1939_session_put(session);
1859 }
1860 
1861 static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
1862 {
1863 	struct j1939_sk_buff_cb *skcb;
1864 	struct j1939_session *session;
1865 
1866 	skcb = j1939_skb_to_cb(skb);
1867 
1868 	if (j1939_tp_im_transmitter(skcb)) {
1869 		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1870 						    true);
1871 		if (!session)
1872 			netdev_info(priv->ndev, "%s: no tx connection found\n",
1873 				    __func__);
1874 		else
1875 			j1939_xtp_rx_dat_one(session, skb);
1876 	}
1877 
1878 	if (j1939_tp_im_receiver(skcb)) {
1879 		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1880 						    false);
1881 		if (!session)
1882 			netdev_info(priv->ndev, "%s: no rx connection found\n",
1883 				    __func__);
1884 		else
1885 			j1939_xtp_rx_dat_one(session, skb);
1886 	}
1887 
1888 	if (j1939_cb_is_broadcast(skcb)) {
1889 		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1890 						    false);
1891 		if (session)
1892 			j1939_xtp_rx_dat_one(session, skb);
1893 	}
1894 }
1895 
1896 /* j1939 main intf */
1897 struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
1898 				    struct sk_buff *skb, size_t size)
1899 {
1900 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1901 	struct j1939_session *session;
1902 	int ret;
1903 
1904 	if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
1905 	    skcb->addr.pgn == J1939_TP_PGN_CTL ||
1906 	    skcb->addr.pgn == J1939_ETP_PGN_DAT ||
1907 	    skcb->addr.pgn == J1939_ETP_PGN_CTL)
1908 		/* avoid conflict */
1909 		return ERR_PTR(-EDOM);
1910 
1911 	if (size > priv->tp_max_packet_size)
1912 		return ERR_PTR(-EMSGSIZE);
1913 
1914 	if (size <= 8)
1915 		skcb->addr.type = J1939_SIMPLE;
1916 	else if (size > J1939_MAX_TP_PACKET_SIZE)
1917 		skcb->addr.type = J1939_ETP;
1918 	else
1919 		skcb->addr.type = J1939_TP;
1920 
1921 	if (skcb->addr.type == J1939_ETP &&
1922 	    j1939_cb_is_broadcast(skcb))
1923 		return ERR_PTR(-EDESTADDRREQ);
1924 
1925 	/* fill in addresses from names */
1926 	ret = j1939_ac_fixup(priv, skb);
1927 	if (unlikely(ret))
1928 		return ERR_PTR(ret);
1929 
1930 	/* fix DST flags, it may be used there soon */
1931 	if (j1939_address_is_unicast(skcb->addr.da) &&
1932 	    priv->ents[skcb->addr.da].nusers)
1933 		skcb->flags |= J1939_ECU_LOCAL_DST;
1934 
1935 	/* src is always local, I'm sending ... */
1936 	skcb->flags |= J1939_ECU_LOCAL_SRC;
1937 
1938 	/* prepare new session */
1939 	session = j1939_session_new(priv, skb, size);
1940 	if (!session)
1941 		return ERR_PTR(-ENOMEM);
1942 
1943 	/* skb is recounted in j1939_session_new() */
1944 	sock_hold(skb->sk);
1945 	session->sk = skb->sk;
1946 	session->transmission = true;
1947 	session->pkt.total = (size + 6) / 7;
1948 	session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
1949 		min(j1939_tp_block ?: 255, session->pkt.total);
1950 
1951 	if (j1939_cb_is_broadcast(&session->skcb))
1952 		/* set the end-packet for broadcast */
1953 		session->pkt.last = session->pkt.total;
1954 
1955 	skcb->tskey = session->sk->sk_tskey++;
1956 	session->tskey = skcb->tskey;
1957 
1958 	return session;
1959 }
1960 
1961 static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
1962 {
1963 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1964 	int extd = J1939_TP;
1965 	u8 cmd = skb->data[0];
1966 
1967 	switch (cmd) {
1968 	case J1939_ETP_CMD_RTS:
1969 		extd = J1939_ETP;
1970 		fallthrough;
1971 	case J1939_TP_CMD_BAM:
1972 	case J1939_TP_CMD_RTS: /* fall through */
1973 		if (skcb->addr.type != extd)
1974 			return;
1975 
1976 		if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
1977 			netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
1978 				     __func__, skcb->addr.sa);
1979 			return;
1980 		}
1981 
1982 		if (j1939_tp_im_transmitter(skcb))
1983 			j1939_xtp_rx_rts(priv, skb, true);
1984 
1985 		if (j1939_tp_im_receiver(skcb) || j1939_cb_is_broadcast(skcb))
1986 			j1939_xtp_rx_rts(priv, skb, false);
1987 
1988 		break;
1989 
1990 	case J1939_ETP_CMD_CTS:
1991 		extd = J1939_ETP;
1992 		fallthrough;
1993 	case J1939_TP_CMD_CTS:
1994 		if (skcb->addr.type != extd)
1995 			return;
1996 
1997 		if (j1939_tp_im_transmitter(skcb))
1998 			j1939_xtp_rx_cts(priv, skb, false);
1999 
2000 		if (j1939_tp_im_receiver(skcb))
2001 			j1939_xtp_rx_cts(priv, skb, true);
2002 
2003 		break;
2004 
2005 	case J1939_ETP_CMD_DPO:
2006 		if (skcb->addr.type != J1939_ETP)
2007 			return;
2008 
2009 		if (j1939_tp_im_transmitter(skcb))
2010 			j1939_xtp_rx_dpo(priv, skb, true);
2011 
2012 		if (j1939_tp_im_receiver(skcb))
2013 			j1939_xtp_rx_dpo(priv, skb, false);
2014 
2015 		break;
2016 
2017 	case J1939_ETP_CMD_EOMA:
2018 		extd = J1939_ETP;
2019 		fallthrough;
2020 	case J1939_TP_CMD_EOMA:
2021 		if (skcb->addr.type != extd)
2022 			return;
2023 
2024 		if (j1939_tp_im_transmitter(skcb))
2025 			j1939_xtp_rx_eoma(priv, skb, false);
2026 
2027 		if (j1939_tp_im_receiver(skcb))
2028 			j1939_xtp_rx_eoma(priv, skb, true);
2029 
2030 		break;
2031 
2032 	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
2033 		if (j1939_tp_im_transmitter(skcb))
2034 			j1939_xtp_rx_abort(priv, skb, true);
2035 
2036 		if (j1939_tp_im_receiver(skcb))
2037 			j1939_xtp_rx_abort(priv, skb, false);
2038 
2039 		break;
2040 	default:
2041 		return;
2042 	}
2043 }
2044 
2045 int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
2046 {
2047 	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
2048 
2049 	if (!j1939_tp_im_involved_anydir(skcb) && !j1939_cb_is_broadcast(skcb))
2050 		return 0;
2051 
2052 	switch (skcb->addr.pgn) {
2053 	case J1939_ETP_PGN_DAT:
2054 		skcb->addr.type = J1939_ETP;
2055 		fallthrough;
2056 	case J1939_TP_PGN_DAT:
2057 		j1939_xtp_rx_dat(priv, skb);
2058 		break;
2059 
2060 	case J1939_ETP_PGN_CTL:
2061 		skcb->addr.type = J1939_ETP;
2062 		fallthrough;
2063 	case J1939_TP_PGN_CTL:
2064 		if (skb->len < 8)
2065 			return 0; /* Don't care. Nothing to extract here */
2066 
2067 		j1939_tp_cmd_recv(priv, skb);
2068 		break;
2069 	default:
2070 		return 0; /* no problem */
2071 	}
2072 	return 1; /* "I processed the message" */
2073 }
2074 
2075 void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
2076 {
2077 	struct j1939_session *session;
2078 
2079 	if (!skb->sk)
2080 		return;
2081 
2082 	if (skb->sk->sk_family != AF_CAN ||
2083 	    skb->sk->sk_protocol != CAN_J1939)
2084 		return;
2085 
2086 	j1939_session_list_lock(priv);
2087 	session = j1939_session_get_simple(priv, skb);
2088 	j1939_session_list_unlock(priv);
2089 	if (!session) {
2090 		netdev_warn(priv->ndev,
2091 			    "%s: Received already invalidated message\n",
2092 			    __func__);
2093 		return;
2094 	}
2095 
2096 	j1939_session_timers_cancel(session);
2097 	j1939_session_deactivate(session);
2098 	j1939_session_put(session);
2099 }
2100 
2101 int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
2102 {
2103 	struct j1939_session *session, *saved;
2104 
2105 	netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
2106 	j1939_session_list_lock(priv);
2107 	list_for_each_entry_safe(session, saved,
2108 				 &priv->active_session_list,
2109 				 active_session_list_entry) {
2110 		if (!sk || sk == session->sk) {
2111 			if (hrtimer_try_to_cancel(&session->txtimer) == 1)
2112 				j1939_session_put(session);
2113 			if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
2114 				j1939_session_put(session);
2115 
2116 			session->err = ESHUTDOWN;
2117 			j1939_session_deactivate_locked(session);
2118 		}
2119 	}
2120 	j1939_session_list_unlock(priv);
2121 	return NOTIFY_DONE;
2122 }
2123 
2124 void j1939_tp_init(struct j1939_priv *priv)
2125 {
2126 	spin_lock_init(&priv->active_session_list_lock);
2127 	INIT_LIST_HEAD(&priv->active_session_list);
2128 	priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
2129 }
2130