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
34enum 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
125static unsigned int j1939_tp_block = 255;
126static unsigned int j1939_tp_packet_delay;
127static unsigned int j1939_tp_padding = 1;
128
129/* helpers */
130static 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
170static 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
236static inline void j1939_session_list_lock(struct j1939_priv *priv)
237{
238	spin_lock_bh(&priv->active_session_list_lock);
239}
240
241static inline void j1939_session_list_unlock(struct j1939_priv *priv)
242{
243	spin_unlock_bh(&priv->active_session_list_lock);
244}
245
246void j1939_session_get(struct j1939_session *session)
247{
248	kref_get(&session->kref);
249}
250
251/* session completion functions */
252static 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
261static void j1939_session_destroy(struct j1939_session *session)
262{
263	struct sk_buff *skb;
264
265	if (session->err)
266		j1939_sk_errqueue(session, J1939_ERRQUEUE_ABORT);
267	else
268		j1939_sk_errqueue(session, J1939_ERRQUEUE_ACK);
269
270	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
271
272	WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry));
273	WARN_ON_ONCE(!list_empty(&session->active_session_list_entry));
274
275	while ((skb = skb_dequeue(&session->skb_queue)) != NULL) {
276		/* drop ref taken in j1939_session_skb_queue() */
277		skb_unref(skb);
278		kfree_skb(skb);
279	}
280	__j1939_session_drop(session);
281	j1939_priv_put(session->priv);
282	kfree(session);
283}
284
285static void __j1939_session_release(struct kref *kref)
286{
287	struct j1939_session *session = container_of(kref, struct j1939_session,
288						     kref);
289
290	j1939_session_destroy(session);
291}
292
293void j1939_session_put(struct j1939_session *session)
294{
295	kref_put(&session->kref, __j1939_session_release);
296}
297
298static void j1939_session_txtimer_cancel(struct j1939_session *session)
299{
300	if (hrtimer_cancel(&session->txtimer))
301		j1939_session_put(session);
302}
303
304static void j1939_session_rxtimer_cancel(struct j1939_session *session)
305{
306	if (hrtimer_cancel(&session->rxtimer))
307		j1939_session_put(session);
308}
309
310void j1939_session_timers_cancel(struct j1939_session *session)
311{
312	j1939_session_txtimer_cancel(session);
313	j1939_session_rxtimer_cancel(session);
314}
315
316static inline bool j1939_cb_is_broadcast(const struct j1939_sk_buff_cb *skcb)
317{
318	return (!skcb->addr.dst_name && (skcb->addr.da == 0xff));
319}
320
321static void j1939_session_skb_drop_old(struct j1939_session *session)
322{
323	struct sk_buff *do_skb;
324	struct j1939_sk_buff_cb *do_skcb;
325	unsigned int offset_start;
326	unsigned long flags;
327
328	if (skb_queue_len(&session->skb_queue) < 2)
329		return;
330
331	offset_start = session->pkt.tx_acked * 7;
332
333	spin_lock_irqsave(&session->skb_queue.lock, flags);
334	do_skb = skb_peek(&session->skb_queue);
335	do_skcb = j1939_skb_to_cb(do_skb);
336
337	if ((do_skcb->offset + do_skb->len) < offset_start) {
338		__skb_unlink(do_skb, &session->skb_queue);
339		/* drop ref taken in j1939_session_skb_queue() */
340		skb_unref(do_skb);
341		spin_unlock_irqrestore(&session->skb_queue.lock, flags);
342
343		kfree_skb(do_skb);
344	} else {
345		spin_unlock_irqrestore(&session->skb_queue.lock, flags);
346	}
347}
348
349void j1939_session_skb_queue(struct j1939_session *session,
350			     struct sk_buff *skb)
351{
352	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
353	struct j1939_priv *priv = session->priv;
354
355	j1939_ac_fixup(priv, skb);
356
357	if (j1939_address_is_unicast(skcb->addr.da) &&
358	    priv->ents[skcb->addr.da].nusers)
359		skcb->flags |= J1939_ECU_LOCAL_DST;
360
361	skcb->flags |= J1939_ECU_LOCAL_SRC;
362
363	skb_get(skb);
364	skb_queue_tail(&session->skb_queue, skb);
365}
366
367static struct
368sk_buff *j1939_session_skb_get_by_offset(struct j1939_session *session,
369					 unsigned int offset_start)
370{
371	struct j1939_priv *priv = session->priv;
372	struct j1939_sk_buff_cb *do_skcb;
373	struct sk_buff *skb = NULL;
374	struct sk_buff *do_skb;
375	unsigned long flags;
376
377	spin_lock_irqsave(&session->skb_queue.lock, flags);
378	skb_queue_walk(&session->skb_queue, do_skb) {
379		do_skcb = j1939_skb_to_cb(do_skb);
380
381		if (offset_start >= do_skcb->offset &&
382		    offset_start < (do_skcb->offset + do_skb->len)) {
383			skb = do_skb;
384		}
385	}
386
387	if (skb)
388		skb_get(skb);
389
390	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
391
392	if (!skb)
393		netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
394			   __func__, session, offset_start,
395			   skb_queue_len(&session->skb_queue));
396
397	return skb;
398}
399
400static struct sk_buff *j1939_session_skb_get(struct j1939_session *session)
401{
402	unsigned int offset_start;
403
404	offset_start = session->pkt.dpo * 7;
405	return j1939_session_skb_get_by_offset(session, offset_start);
406}
407
408/* see if we are receiver
409 * returns 0 for broadcasts, although we will receive them
410 */
411static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
412{
413	return skcb->flags & J1939_ECU_LOCAL_DST;
414}
415
416/* see if we are sender */
417static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
418{
419	return skcb->flags & J1939_ECU_LOCAL_SRC;
420}
421
422/* see if we are involved as either receiver or transmitter */
423static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
424{
425	if (swap)
426		return j1939_tp_im_receiver(skcb);
427	else
428		return j1939_tp_im_transmitter(skcb);
429}
430
431static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
432{
433	return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
434}
435
436/* extract pgn from flow-ctl message */
437static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
438{
439	pgn_t pgn;
440
441	pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
442	if (j1939_pgn_is_pdu1(pgn))
443		pgn &= 0xffff00;
444	return pgn;
445}
446
447static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
448{
449	return (dat[2] << 8) + (dat[1] << 0);
450}
451
452static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
453{
454	return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
455}
456
457static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
458{
459	return (dat[4] << 24) | (dat[3] << 16) |
460		(dat[2] << 8) | (dat[1] << 0);
461}
462
463/* find existing session:
464 * reverse: swap cb's src & dst
465 * there is no problem with matching broadcasts, since
466 * broadcasts (no dst, no da) would never call this
467 * with reverse == true
468 */
469static bool j1939_session_match(struct j1939_addr *se_addr,
470				struct j1939_addr *sk_addr, bool reverse)
471{
472	if (se_addr->type != sk_addr->type)
473		return false;
474
475	if (reverse) {
476		if (se_addr->src_name) {
477			if (se_addr->src_name != sk_addr->dst_name)
478				return false;
479		} else if (se_addr->sa != sk_addr->da) {
480			return false;
481		}
482
483		if (se_addr->dst_name) {
484			if (se_addr->dst_name != sk_addr->src_name)
485				return false;
486		} else if (se_addr->da != sk_addr->sa) {
487			return false;
488		}
489	} else {
490		if (se_addr->src_name) {
491			if (se_addr->src_name != sk_addr->src_name)
492				return false;
493		} else if (se_addr->sa != sk_addr->sa) {
494			return false;
495		}
496
497		if (se_addr->dst_name) {
498			if (se_addr->dst_name != sk_addr->dst_name)
499				return false;
500		} else if (se_addr->da != sk_addr->da) {
501			return false;
502		}
503	}
504
505	return true;
506}
507
508static struct
509j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
510						struct list_head *root,
511						struct j1939_addr *addr,
512						bool reverse, bool transmitter)
513{
514	struct j1939_session *session;
515
516	lockdep_assert_held(&priv->active_session_list_lock);
517
518	list_for_each_entry(session, root, active_session_list_entry) {
519		j1939_session_get(session);
520		if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
521		    session->transmission == transmitter)
522			return session;
523		j1939_session_put(session);
524	}
525
526	return NULL;
527}
528
529static struct
530j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
531					struct sk_buff *skb)
532{
533	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
534	struct j1939_session *session;
535
536	lockdep_assert_held(&priv->active_session_list_lock);
537
538	list_for_each_entry(session, &priv->active_session_list,
539			    active_session_list_entry) {
540		j1939_session_get(session);
541		if (session->skcb.addr.type == J1939_SIMPLE &&
542		    session->tskey == skcb->tskey && session->sk == skb->sk)
543			return session;
544		j1939_session_put(session);
545	}
546
547	return NULL;
548}
549
550static struct
551j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
552					 struct j1939_addr *addr,
553					 bool reverse, bool transmitter)
554{
555	struct j1939_session *session;
556
557	j1939_session_list_lock(priv);
558	session = j1939_session_get_by_addr_locked(priv,
559						   &priv->active_session_list,
560						   addr, reverse, transmitter);
561	j1939_session_list_unlock(priv);
562
563	return session;
564}
565
566static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
567{
568	u8 tmp = 0;
569
570	swap(skcb->addr.dst_name, skcb->addr.src_name);
571	swap(skcb->addr.da, skcb->addr.sa);
572
573	/* swap SRC and DST flags, leave other untouched */
574	if (skcb->flags & J1939_ECU_LOCAL_SRC)
575		tmp |= J1939_ECU_LOCAL_DST;
576	if (skcb->flags & J1939_ECU_LOCAL_DST)
577		tmp |= J1939_ECU_LOCAL_SRC;
578	skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
579	skcb->flags |= tmp;
580}
581
582static struct
583sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
584			     const struct j1939_sk_buff_cb *re_skcb,
585			     bool ctl,
586			     bool swap_src_dst)
587{
588	struct sk_buff *skb;
589	struct j1939_sk_buff_cb *skcb;
590
591	skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
592			GFP_ATOMIC);
593	if (unlikely(!skb))
594		return ERR_PTR(-ENOMEM);
595
596	skb->dev = priv->ndev;
597	can_skb_reserve(skb);
598	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
599	can_skb_prv(skb)->skbcnt = 0;
600	/* reserve CAN header */
601	skb_reserve(skb, offsetof(struct can_frame, data));
602
603	/* skb->cb must be large enough to hold a j1939_sk_buff_cb structure */
604	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*re_skcb));
605
606	memcpy(skb->cb, re_skcb, sizeof(*re_skcb));
607	skcb = j1939_skb_to_cb(skb);
608	if (swap_src_dst)
609		j1939_skbcb_swap(skcb);
610
611	if (ctl) {
612		if (skcb->addr.type == J1939_ETP)
613			skcb->addr.pgn = J1939_ETP_PGN_CTL;
614		else
615			skcb->addr.pgn = J1939_TP_PGN_CTL;
616	} else {
617		if (skcb->addr.type == J1939_ETP)
618			skcb->addr.pgn = J1939_ETP_PGN_DAT;
619		else
620			skcb->addr.pgn = J1939_TP_PGN_DAT;
621	}
622
623	return skb;
624}
625
626/* TP transmit packet functions */
627static int j1939_tp_tx_dat(struct j1939_session *session,
628			   const u8 *dat, int len)
629{
630	struct j1939_priv *priv = session->priv;
631	struct sk_buff *skb;
632
633	skb = j1939_tp_tx_dat_new(priv, &session->skcb,
634				  false, false);
635	if (IS_ERR(skb))
636		return PTR_ERR(skb);
637
638	skb_put_data(skb, dat, len);
639	if (j1939_tp_padding && len < 8)
640		memset(skb_put(skb, 8 - len), 0xff, 8 - len);
641
642	return j1939_send_one(priv, skb);
643}
644
645static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
646			       const struct j1939_sk_buff_cb *re_skcb,
647			       bool swap_src_dst, pgn_t pgn, const u8 *dat)
648{
649	struct sk_buff *skb;
650	u8 *skdat;
651
652	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
653		return 0;
654
655	skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
656	if (IS_ERR(skb))
657		return PTR_ERR(skb);
658
659	skdat = skb_put(skb, 8);
660	memcpy(skdat, dat, 5);
661	skdat[5] = (pgn >> 0);
662	skdat[6] = (pgn >> 8);
663	skdat[7] = (pgn >> 16);
664
665	return j1939_send_one(priv, skb);
666}
667
668static inline int j1939_tp_tx_ctl(struct j1939_session *session,
669				  bool swap_src_dst, const u8 *dat)
670{
671	struct j1939_priv *priv = session->priv;
672
673	return j1939_xtp_do_tx_ctl(priv, &session->skcb,
674				   swap_src_dst,
675				   session->skcb.addr.pgn, dat);
676}
677
678static int j1939_xtp_tx_abort(struct j1939_priv *priv,
679			      const struct j1939_sk_buff_cb *re_skcb,
680			      bool swap_src_dst,
681			      enum j1939_xtp_abort err,
682			      pgn_t pgn)
683{
684	u8 dat[5];
685
686	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
687		return 0;
688
689	memset(dat, 0xff, sizeof(dat));
690	dat[0] = J1939_TP_CMD_ABORT;
691	dat[1] = err;
692	return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
693}
694
695void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
696{
697	j1939_session_get(session);
698	hrtimer_start(&session->txtimer, ms_to_ktime(msec),
699		      HRTIMER_MODE_REL_SOFT);
700}
701
702static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
703					  int msec)
704{
705	j1939_session_rxtimer_cancel(session);
706	j1939_session_get(session);
707	hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
708		      HRTIMER_MODE_REL_SOFT);
709}
710
711static int j1939_session_tx_rts(struct j1939_session *session)
712{
713	u8 dat[8];
714	int ret;
715
716	memset(dat, 0xff, sizeof(dat));
717
718	dat[1] = (session->total_message_size >> 0);
719	dat[2] = (session->total_message_size >> 8);
720	dat[3] = session->pkt.total;
721
722	if (session->skcb.addr.type == J1939_ETP) {
723		dat[0] = J1939_ETP_CMD_RTS;
724		dat[1] = (session->total_message_size >> 0);
725		dat[2] = (session->total_message_size >> 8);
726		dat[3] = (session->total_message_size >> 16);
727		dat[4] = (session->total_message_size >> 24);
728	} else if (j1939_cb_is_broadcast(&session->skcb)) {
729		dat[0] = J1939_TP_CMD_BAM;
730		/* fake cts for broadcast */
731		session->pkt.tx = 0;
732	} else {
733		dat[0] = J1939_TP_CMD_RTS;
734		dat[4] = dat[3];
735	}
736
737	if (dat[0] == session->last_txcmd)
738		/* done already */
739		return 0;
740
741	ret = j1939_tp_tx_ctl(session, false, dat);
742	if (ret < 0)
743		return ret;
744
745	session->last_txcmd = dat[0];
746	if (dat[0] == J1939_TP_CMD_BAM) {
747		j1939_tp_schedule_txtimer(session, 50);
748		j1939_tp_set_rxtimeout(session, 250);
749	} else {
750		j1939_tp_set_rxtimeout(session, 1250);
751	}
752
753	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
754
755	return 0;
756}
757
758static int j1939_session_tx_dpo(struct j1939_session *session)
759{
760	unsigned int pkt;
761	u8 dat[8];
762	int ret;
763
764	memset(dat, 0xff, sizeof(dat));
765
766	dat[0] = J1939_ETP_CMD_DPO;
767	session->pkt.dpo = session->pkt.tx_acked;
768	pkt = session->pkt.dpo;
769	dat[1] = session->pkt.last - session->pkt.tx_acked;
770	dat[2] = (pkt >> 0);
771	dat[3] = (pkt >> 8);
772	dat[4] = (pkt >> 16);
773
774	ret = j1939_tp_tx_ctl(session, false, dat);
775	if (ret < 0)
776		return ret;
777
778	session->last_txcmd = dat[0];
779	j1939_tp_set_rxtimeout(session, 1250);
780	session->pkt.tx = session->pkt.tx_acked;
781
782	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
783
784	return 0;
785}
786
787static int j1939_session_tx_dat(struct j1939_session *session)
788{
789	struct j1939_priv *priv = session->priv;
790	struct j1939_sk_buff_cb *skcb;
791	int offset, pkt_done, pkt_end;
792	unsigned int len, pdelay;
793	struct sk_buff *se_skb;
794	const u8 *tpdat;
795	int ret = 0;
796	u8 dat[8];
797
798	se_skb = j1939_session_skb_get_by_offset(session, session->pkt.tx * 7);
799	if (!se_skb)
800		return -ENOBUFS;
801
802	skcb = j1939_skb_to_cb(se_skb);
803	tpdat = se_skb->data;
804	ret = 0;
805	pkt_done = 0;
806	if (session->skcb.addr.type != J1939_ETP &&
807	    j1939_cb_is_broadcast(&session->skcb))
808		pkt_end = session->pkt.total;
809	else
810		pkt_end = session->pkt.last;
811
812	while (session->pkt.tx < pkt_end) {
813		dat[0] = session->pkt.tx - session->pkt.dpo + 1;
814		offset = (session->pkt.tx * 7) - skcb->offset;
815		len =  se_skb->len - offset;
816		if (len > 7)
817			len = 7;
818
819		if (offset + len > se_skb->len) {
820			netdev_err_once(priv->ndev,
821					"%s: 0x%p: requested data outside of queued buffer: offset %i, len %i, pkt.tx: %i\n",
822					__func__, session, skcb->offset, se_skb->len , session->pkt.tx);
823			ret = -EOVERFLOW;
824			goto out_free;
825		}
826
827		if (!len) {
828			ret = -ENOBUFS;
829			break;
830		}
831
832		memcpy(&dat[1], &tpdat[offset], len);
833		ret = j1939_tp_tx_dat(session, dat, len + 1);
834		if (ret < 0) {
835			/* ENOBUS == CAN interface TX queue is full */
836			if (ret != -ENOBUFS)
837				netdev_alert(priv->ndev,
838					     "%s: 0x%p: queue data error: %i\n",
839					     __func__, session, ret);
840			break;
841		}
842
843		session->last_txcmd = 0xff;
844		pkt_done++;
845		session->pkt.tx++;
846		pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
847			j1939_tp_packet_delay;
848
849		if (session->pkt.tx < session->pkt.total && pdelay) {
850			j1939_tp_schedule_txtimer(session, pdelay);
851			break;
852		}
853	}
854
855	if (pkt_done)
856		j1939_tp_set_rxtimeout(session, 250);
857
858 out_free:
859	if (ret)
860		kfree_skb(se_skb);
861	else
862		consume_skb(se_skb);
863
864	return ret;
865}
866
867static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
868{
869	struct j1939_priv *priv = session->priv;
870	int ret = 0;
871
872	if (!j1939_tp_im_transmitter(&session->skcb)) {
873		netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
874			     __func__, session);
875		return -EINVAL;
876	}
877
878	switch (session->last_cmd) {
879	case 0:
880		ret = j1939_session_tx_rts(session);
881		break;
882
883	case J1939_ETP_CMD_CTS:
884		if (session->last_txcmd != J1939_ETP_CMD_DPO) {
885			ret = j1939_session_tx_dpo(session);
886			if (ret)
887				return ret;
888		}
889
890		fallthrough;
891	case J1939_TP_CMD_CTS:
892	case 0xff: /* did some data */
893	case J1939_ETP_CMD_DPO:
894	case J1939_TP_CMD_BAM:
895		ret = j1939_session_tx_dat(session);
896
897		break;
898	default:
899		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
900			     __func__, session, session->last_cmd);
901	}
902
903	return ret;
904}
905
906static int j1939_session_tx_cts(struct j1939_session *session)
907{
908	struct j1939_priv *priv = session->priv;
909	unsigned int pkt, len;
910	int ret;
911	u8 dat[8];
912
913	if (!j1939_sk_recv_match(priv, &session->skcb))
914		return -ENOENT;
915
916	len = session->pkt.total - session->pkt.rx;
917	len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
918	memset(dat, 0xff, sizeof(dat));
919
920	if (session->skcb.addr.type == J1939_ETP) {
921		pkt = session->pkt.rx + 1;
922		dat[0] = J1939_ETP_CMD_CTS;
923		dat[1] = len;
924		dat[2] = (pkt >> 0);
925		dat[3] = (pkt >> 8);
926		dat[4] = (pkt >> 16);
927	} else {
928		dat[0] = J1939_TP_CMD_CTS;
929		dat[1] = len;
930		dat[2] = session->pkt.rx + 1;
931	}
932
933	if (dat[0] == session->last_txcmd)
934		/* done already */
935		return 0;
936
937	ret = j1939_tp_tx_ctl(session, true, dat);
938	if (ret < 0)
939		return ret;
940
941	if (len)
942		/* only mark cts done when len is set */
943		session->last_txcmd = dat[0];
944	j1939_tp_set_rxtimeout(session, 1250);
945
946	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
947
948	return 0;
949}
950
951static int j1939_session_tx_eoma(struct j1939_session *session)
952{
953	struct j1939_priv *priv = session->priv;
954	u8 dat[8];
955	int ret;
956
957	if (!j1939_sk_recv_match(priv, &session->skcb))
958		return -ENOENT;
959
960	memset(dat, 0xff, sizeof(dat));
961
962	if (session->skcb.addr.type == J1939_ETP) {
963		dat[0] = J1939_ETP_CMD_EOMA;
964		dat[1] = session->total_message_size >> 0;
965		dat[2] = session->total_message_size >> 8;
966		dat[3] = session->total_message_size >> 16;
967		dat[4] = session->total_message_size >> 24;
968	} else {
969		dat[0] = J1939_TP_CMD_EOMA;
970		dat[1] = session->total_message_size;
971		dat[2] = session->total_message_size >> 8;
972		dat[3] = session->pkt.total;
973	}
974
975	if (dat[0] == session->last_txcmd)
976		/* done already */
977		return 0;
978
979	ret = j1939_tp_tx_ctl(session, true, dat);
980	if (ret < 0)
981		return ret;
982
983	session->last_txcmd = dat[0];
984
985	/* wait for the EOMA packet to come in */
986	j1939_tp_set_rxtimeout(session, 1250);
987
988	netdev_dbg(session->priv->ndev, "%p: 0x%p\n", __func__, session);
989
990	return 0;
991}
992
993static int j1939_xtp_txnext_receiver(struct j1939_session *session)
994{
995	struct j1939_priv *priv = session->priv;
996	int ret = 0;
997
998	if (!j1939_tp_im_receiver(&session->skcb)) {
999		netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
1000			     __func__, session);
1001		return -EINVAL;
1002	}
1003
1004	switch (session->last_cmd) {
1005	case J1939_TP_CMD_RTS:
1006	case J1939_ETP_CMD_RTS:
1007		ret = j1939_session_tx_cts(session);
1008		break;
1009
1010	case J1939_ETP_CMD_CTS:
1011	case J1939_TP_CMD_CTS:
1012	case 0xff: /* did some data */
1013	case J1939_ETP_CMD_DPO:
1014		if ((session->skcb.addr.type == J1939_TP &&
1015		     j1939_cb_is_broadcast(&session->skcb)))
1016			break;
1017
1018		if (session->pkt.rx >= session->pkt.total) {
1019			ret = j1939_session_tx_eoma(session);
1020		} else if (session->pkt.rx >= session->pkt.last) {
1021			session->last_txcmd = 0;
1022			ret = j1939_session_tx_cts(session);
1023		}
1024		break;
1025	default:
1026		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
1027			     __func__, session, session->last_cmd);
1028	}
1029
1030	return ret;
1031}
1032
1033static int j1939_simple_txnext(struct j1939_session *session)
1034{
1035	struct j1939_priv *priv = session->priv;
1036	struct sk_buff *se_skb = j1939_session_skb_get(session);
1037	struct sk_buff *skb;
1038	int ret;
1039
1040	if (!se_skb)
1041		return 0;
1042
1043	skb = skb_clone(se_skb, GFP_ATOMIC);
1044	if (!skb) {
1045		ret = -ENOMEM;
1046		goto out_free;
1047	}
1048
1049	can_skb_set_owner(skb, se_skb->sk);
1050
1051	j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
1052
1053	ret = j1939_send_one(priv, skb);
1054	if (ret)
1055		goto out_free;
1056
1057	j1939_sk_errqueue(session, J1939_ERRQUEUE_SCHED);
1058	j1939_sk_queue_activate_next(session);
1059
1060 out_free:
1061	if (ret)
1062		kfree_skb(se_skb);
1063	else
1064		consume_skb(se_skb);
1065
1066	return ret;
1067}
1068
1069static bool j1939_session_deactivate_locked(struct j1939_session *session)
1070{
1071	bool active = false;
1072
1073	lockdep_assert_held(&session->priv->active_session_list_lock);
1074
1075	if (session->state >= J1939_SESSION_ACTIVE &&
1076	    session->state < J1939_SESSION_ACTIVE_MAX) {
1077		active = true;
1078
1079		list_del_init(&session->active_session_list_entry);
1080		session->state = J1939_SESSION_DONE;
1081		j1939_session_put(session);
1082	}
1083
1084	return active;
1085}
1086
1087static bool j1939_session_deactivate(struct j1939_session *session)
1088{
1089	struct j1939_priv *priv = session->priv;
1090	bool active;
1091
1092	j1939_session_list_lock(priv);
1093	active = j1939_session_deactivate_locked(session);
1094	j1939_session_list_unlock(priv);
1095
1096	return active;
1097}
1098
1099static void
1100j1939_session_deactivate_activate_next(struct j1939_session *session)
1101{
1102	if (j1939_session_deactivate(session))
1103		j1939_sk_queue_activate_next(session);
1104}
1105
1106static void __j1939_session_cancel(struct j1939_session *session,
1107				 enum j1939_xtp_abort err)
1108{
1109	struct j1939_priv *priv = session->priv;
1110
1111	WARN_ON_ONCE(!err);
1112	lockdep_assert_held(&session->priv->active_session_list_lock);
1113
1114	session->err = j1939_xtp_abort_to_errno(priv, err);
1115	session->state = J1939_SESSION_WAITING_ABORT;
1116	/* do not send aborts on incoming broadcasts */
1117	if (!j1939_cb_is_broadcast(&session->skcb)) {
1118		j1939_xtp_tx_abort(priv, &session->skcb,
1119				   !session->transmission,
1120				   err, session->skcb.addr.pgn);
1121	}
1122
1123	if (session->sk)
1124		j1939_sk_send_loop_abort(session->sk, session->err);
1125}
1126
1127static void j1939_session_cancel(struct j1939_session *session,
1128				 enum j1939_xtp_abort err)
1129{
1130	j1939_session_list_lock(session->priv);
1131
1132	if (session->state >= J1939_SESSION_ACTIVE &&
1133	    session->state < J1939_SESSION_WAITING_ABORT) {
1134		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
1135		__j1939_session_cancel(session, err);
1136	}
1137
1138	j1939_session_list_unlock(session->priv);
1139}
1140
1141static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
1142{
1143	struct j1939_session *session =
1144		container_of(hrtimer, struct j1939_session, txtimer);
1145	struct j1939_priv *priv = session->priv;
1146	int ret = 0;
1147
1148	if (session->skcb.addr.type == J1939_SIMPLE) {
1149		ret = j1939_simple_txnext(session);
1150	} else {
1151		if (session->transmission)
1152			ret = j1939_xtp_txnext_transmiter(session);
1153		else
1154			ret = j1939_xtp_txnext_receiver(session);
1155	}
1156
1157	switch (ret) {
1158	case -ENOBUFS:
1159		/* Retry limit is currently arbitrary chosen */
1160		if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
1161			session->tx_retry++;
1162			j1939_tp_schedule_txtimer(session,
1163						  10 + prandom_u32_max(16));
1164		} else {
1165			netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
1166				     __func__, session);
1167			session->err = -ENETUNREACH;
1168			j1939_session_rxtimer_cancel(session);
1169			j1939_session_deactivate_activate_next(session);
1170		}
1171		break;
1172	case -ENETDOWN:
1173		/* In this case we should get a netdev_event(), all active
1174		 * sessions will be cleared by
1175		 * j1939_cancel_all_active_sessions(). So handle this as an
1176		 * error, but let j1939_cancel_all_active_sessions() do the
1177		 * cleanup including propagation of the error to user space.
1178		 */
1179		break;
1180	case -EOVERFLOW:
1181		j1939_session_cancel(session, J1939_XTP_ABORT_ECTS_TOO_BIG);
1182		break;
1183	case 0:
1184		session->tx_retry = 0;
1185		break;
1186	default:
1187		netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
1188			     __func__, session, ret);
1189		if (session->skcb.addr.type != J1939_SIMPLE) {
1190			j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
1191		} else {
1192			session->err = ret;
1193			j1939_session_rxtimer_cancel(session);
1194			j1939_session_deactivate_activate_next(session);
1195		}
1196	}
1197
1198	j1939_session_put(session);
1199
1200	return HRTIMER_NORESTART;
1201}
1202
1203static void j1939_session_completed(struct j1939_session *session)
1204{
1205	struct sk_buff *skb;
1206
1207	if (!session->transmission) {
1208		skb = j1939_session_skb_get(session);
1209		/* distribute among j1939 receivers */
1210		j1939_sk_recv(session->priv, skb);
1211		consume_skb(skb);
1212	}
1213
1214	j1939_session_deactivate_activate_next(session);
1215}
1216
1217static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
1218{
1219	struct j1939_session *session = container_of(hrtimer,
1220						     struct j1939_session,
1221						     rxtimer);
1222	struct j1939_priv *priv = session->priv;
1223
1224	if (session->state == J1939_SESSION_WAITING_ABORT) {
1225		netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
1226			     __func__, session);
1227
1228		j1939_session_deactivate_activate_next(session);
1229
1230	} else if (session->skcb.addr.type == J1939_SIMPLE) {
1231		netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
1232			     __func__, session);
1233
1234		/* The message is probably stuck in the CAN controller and can
1235		 * be send as soon as CAN bus is in working state again.
1236		 */
1237		session->err = -ETIME;
1238		j1939_session_deactivate(session);
1239	} else {
1240		j1939_session_list_lock(session->priv);
1241		if (session->state >= J1939_SESSION_ACTIVE &&
1242		    session->state < J1939_SESSION_ACTIVE_MAX) {
1243			netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
1244				     __func__, session);
1245			j1939_session_get(session);
1246			hrtimer_start(&session->rxtimer,
1247				      ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
1248				      HRTIMER_MODE_REL_SOFT);
1249			__j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
1250		}
1251		j1939_session_list_unlock(session->priv);
1252	}
1253
1254	j1939_session_put(session);
1255
1256	return HRTIMER_NORESTART;
1257}
1258
1259static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
1260				     const struct sk_buff *skb)
1261{
1262	const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1263	pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
1264	struct j1939_priv *priv = session->priv;
1265	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1266	u8 cmd = skb->data[0];
1267
1268	if (session->skcb.addr.pgn == pgn)
1269		return false;
1270
1271	switch (cmd) {
1272	case J1939_TP_CMD_BAM:
1273		abort = J1939_XTP_NO_ABORT;
1274		break;
1275
1276	case J1939_ETP_CMD_RTS:
1277	case J1939_TP_CMD_RTS: /* fall through */
1278		abort = J1939_XTP_ABORT_BUSY;
1279		break;
1280
1281	case J1939_ETP_CMD_CTS:
1282	case J1939_TP_CMD_CTS: /* fall through */
1283		abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
1284		break;
1285
1286	case J1939_ETP_CMD_DPO:
1287		abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
1288		break;
1289
1290	case J1939_ETP_CMD_EOMA:
1291	case J1939_TP_CMD_EOMA: /* fall through */
1292		abort = J1939_XTP_ABORT_OTHER;
1293		break;
1294
1295	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
1296		abort = J1939_XTP_NO_ABORT;
1297		break;
1298
1299	default:
1300		WARN_ON_ONCE(1);
1301		break;
1302	}
1303
1304	netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
1305		    __func__, session, cmd, pgn, session->skcb.addr.pgn);
1306	if (abort != J1939_XTP_NO_ABORT)
1307		j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
1308
1309	return true;
1310}
1311
1312static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
1313				   bool reverse, bool transmitter)
1314{
1315	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1316	struct j1939_session *session;
1317	u8 abort = skb->data[1];
1318
1319	session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
1320					    transmitter);
1321	if (!session)
1322		return;
1323
1324	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1325		goto abort_put;
1326
1327	netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
1328		    session, j1939_xtp_ctl_to_pgn(skb->data), abort,
1329		    j1939_xtp_abort_to_str(abort));
1330
1331	j1939_session_timers_cancel(session);
1332	session->err = j1939_xtp_abort_to_errno(priv, abort);
1333	if (session->sk)
1334		j1939_sk_send_loop_abort(session->sk, session->err);
1335	j1939_session_deactivate_activate_next(session);
1336
1337abort_put:
1338	j1939_session_put(session);
1339}
1340
1341/* abort packets may come in 2 directions */
1342static void
1343j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
1344		   bool transmitter)
1345{
1346	j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
1347	j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
1348}
1349
1350static void
1351j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
1352{
1353	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1354	const u8 *dat;
1355	int len;
1356
1357	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1358		return;
1359
1360	dat = skb->data;
1361
1362	if (skcb->addr.type == J1939_ETP)
1363		len = j1939_etp_ctl_to_size(dat);
1364	else
1365		len = j1939_tp_ctl_to_size(dat);
1366
1367	if (session->total_message_size != len) {
1368		netdev_warn_once(session->priv->ndev,
1369				 "%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
1370				 __func__, session, session->total_message_size,
1371				 len);
1372	}
1373
1374	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1375
1376	session->pkt.tx_acked = session->pkt.total;
1377	j1939_session_timers_cancel(session);
1378	/* transmitted without problems */
1379	j1939_session_completed(session);
1380}
1381
1382static void
1383j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
1384		  bool transmitter)
1385{
1386	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1387	struct j1939_session *session;
1388
1389	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1390					    transmitter);
1391	if (!session)
1392		return;
1393
1394	j1939_xtp_rx_eoma_one(session, skb);
1395	j1939_session_put(session);
1396}
1397
1398static void
1399j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
1400{
1401	enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
1402	unsigned int pkt;
1403	const u8 *dat;
1404
1405	dat = skb->data;
1406
1407	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1408		return;
1409
1410	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1411
1412	if (session->last_cmd == dat[0]) {
1413		err = J1939_XTP_ABORT_DUP_SEQ;
1414		goto out_session_cancel;
1415	}
1416
1417	if (session->skcb.addr.type == J1939_ETP)
1418		pkt = j1939_etp_ctl_to_packet(dat);
1419	else
1420		pkt = dat[2];
1421
1422	if (!pkt)
1423		goto out_session_cancel;
1424	else if (dat[1] > session->pkt.block /* 0xff for etp */)
1425		goto out_session_cancel;
1426
1427	/* set packet counters only when not CTS(0) */
1428	session->pkt.tx_acked = pkt - 1;
1429	j1939_session_skb_drop_old(session);
1430	session->pkt.last = session->pkt.tx_acked + dat[1];
1431	if (session->pkt.last > session->pkt.total)
1432		/* safety measure */
1433		session->pkt.last = session->pkt.total;
1434	/* TODO: do not set tx here, do it in txtimer */
1435	session->pkt.tx = session->pkt.tx_acked;
1436
1437	session->last_cmd = dat[0];
1438	if (dat[1]) {
1439		j1939_tp_set_rxtimeout(session, 1250);
1440		if (session->transmission) {
1441			if (session->pkt.tx_acked)
1442				j1939_sk_errqueue(session,
1443						  J1939_ERRQUEUE_SCHED);
1444			j1939_session_txtimer_cancel(session);
1445			j1939_tp_schedule_txtimer(session, 0);
1446		}
1447	} else {
1448		/* CTS(0) */
1449		j1939_tp_set_rxtimeout(session, 550);
1450	}
1451	return;
1452
1453 out_session_cancel:
1454	j1939_session_timers_cancel(session);
1455	j1939_session_cancel(session, err);
1456}
1457
1458static void
1459j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
1460{
1461	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1462	struct j1939_session *session;
1463
1464	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
1465					    transmitter);
1466	if (!session)
1467		return;
1468	j1939_xtp_rx_cts_one(session, skb);
1469	j1939_session_put(session);
1470}
1471
1472static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
1473					       struct sk_buff *skb, size_t size)
1474{
1475	struct j1939_session *session;
1476	struct j1939_sk_buff_cb *skcb;
1477
1478	session = kzalloc(sizeof(*session), gfp_any());
1479	if (!session)
1480		return NULL;
1481
1482	INIT_LIST_HEAD(&session->active_session_list_entry);
1483	INIT_LIST_HEAD(&session->sk_session_queue_entry);
1484	kref_init(&session->kref);
1485
1486	j1939_priv_get(priv);
1487	session->priv = priv;
1488	session->total_message_size = size;
1489	session->state = J1939_SESSION_NEW;
1490
1491	skb_queue_head_init(&session->skb_queue);
1492	skb_queue_tail(&session->skb_queue, skb);
1493
1494	skcb = j1939_skb_to_cb(skb);
1495	memcpy(&session->skcb, skcb, sizeof(session->skcb));
1496
1497	hrtimer_init(&session->txtimer, CLOCK_MONOTONIC,
1498		     HRTIMER_MODE_REL_SOFT);
1499	session->txtimer.function = j1939_tp_txtimer;
1500	hrtimer_init(&session->rxtimer, CLOCK_MONOTONIC,
1501		     HRTIMER_MODE_REL_SOFT);
1502	session->rxtimer.function = j1939_tp_rxtimer;
1503
1504	netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
1505		   __func__, session, skcb->addr.sa, skcb->addr.da);
1506
1507	return session;
1508}
1509
1510static struct
1511j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
1512				       int size,
1513				       const struct j1939_sk_buff_cb *rel_skcb)
1514{
1515	struct sk_buff *skb;
1516	struct j1939_sk_buff_cb *skcb;
1517	struct j1939_session *session;
1518
1519	skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
1520	if (unlikely(!skb))
1521		return NULL;
1522
1523	skb->dev = priv->ndev;
1524	can_skb_reserve(skb);
1525	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
1526	can_skb_prv(skb)->skbcnt = 0;
1527	skcb = j1939_skb_to_cb(skb);
1528	memcpy(skcb, rel_skcb, sizeof(*skcb));
1529
1530	session = j1939_session_new(priv, skb, size);
1531	if (!session) {
1532		kfree_skb(skb);
1533		return NULL;
1534	}
1535
1536	/* alloc data area */
1537	skb_put(skb, size);
1538	/* skb is recounted in j1939_session_new() */
1539	return session;
1540}
1541
1542int j1939_session_activate(struct j1939_session *session)
1543{
1544	struct j1939_priv *priv = session->priv;
1545	struct j1939_session *active = NULL;
1546	int ret = 0;
1547
1548	j1939_session_list_lock(priv);
1549	if (session->skcb.addr.type != J1939_SIMPLE)
1550		active = j1939_session_get_by_addr_locked(priv,
1551							  &priv->active_session_list,
1552							  &session->skcb.addr, false,
1553							  session->transmission);
1554	if (active) {
1555		j1939_session_put(active);
1556		ret = -EAGAIN;
1557	} else {
1558		WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
1559		list_add_tail(&session->active_session_list_entry,
1560			      &priv->active_session_list);
1561		j1939_session_get(session);
1562		session->state = J1939_SESSION_ACTIVE;
1563
1564		netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
1565			   __func__, session);
1566	}
1567	j1939_session_list_unlock(priv);
1568
1569	return ret;
1570}
1571
1572static struct
1573j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
1574					    struct sk_buff *skb)
1575{
1576	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
1577	struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
1578	struct j1939_session *session;
1579	const u8 *dat;
1580	pgn_t pgn;
1581	int len;
1582
1583	netdev_dbg(priv->ndev, "%s\n", __func__);
1584
1585	dat = skb->data;
1586	pgn = j1939_xtp_ctl_to_pgn(dat);
1587	skcb.addr.pgn = pgn;
1588
1589	if (!j1939_sk_recv_match(priv, &skcb))
1590		return NULL;
1591
1592	if (skcb.addr.type == J1939_ETP) {
1593		len = j1939_etp_ctl_to_size(dat);
1594		if (len > J1939_MAX_ETP_PACKET_SIZE)
1595			abort = J1939_XTP_ABORT_FAULT;
1596		else if (len > priv->tp_max_packet_size)
1597			abort = J1939_XTP_ABORT_RESOURCE;
1598		else if (len <= J1939_MAX_TP_PACKET_SIZE)
1599			abort = J1939_XTP_ABORT_FAULT;
1600	} else {
1601		len = j1939_tp_ctl_to_size(dat);
1602		if (len > J1939_MAX_TP_PACKET_SIZE)
1603			abort = J1939_XTP_ABORT_FAULT;
1604		else if (len > priv->tp_max_packet_size)
1605			abort = J1939_XTP_ABORT_RESOURCE;
1606		else if (len < J1939_MIN_TP_PACKET_SIZE)
1607			abort = J1939_XTP_ABORT_FAULT;
1608	}
1609
1610	if (abort != J1939_XTP_NO_ABORT) {
1611		j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
1612		return NULL;
1613	}
1614
1615	session = j1939_session_fresh_new(priv, len, &skcb);
1616	if (!session) {
1617		j1939_xtp_tx_abort(priv, &skcb, true,
1618				   J1939_XTP_ABORT_RESOURCE, pgn);
1619		return NULL;
1620	}
1621
1622	/* initialize the control buffer: plain copy */
1623	session->pkt.total = (len + 6) / 7;
1624	session->pkt.block = 0xff;
1625	if (skcb.addr.type != J1939_ETP) {
1626		if (dat[3] != session->pkt.total)
1627			netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
1628				     __func__, session, session->pkt.total,
1629				     dat[3]);
1630		session->pkt.total = dat[3];
1631		session->pkt.block = min(dat[3], dat[4]);
1632	}
1633
1634	session->pkt.rx = 0;
1635	session->pkt.tx = 0;
1636
1637	WARN_ON_ONCE(j1939_session_activate(session));
1638
1639	return session;
1640}
1641
1642static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
1643					   struct sk_buff *skb)
1644{
1645	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1646	struct j1939_priv *priv = session->priv;
1647
1648	if (!session->transmission) {
1649		if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1650			return -EBUSY;
1651
1652		/* RTS on active session */
1653		j1939_session_timers_cancel(session);
1654		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1655	}
1656
1657	if (session->last_cmd != 0) {
1658		/* we received a second rts on the same connection */
1659		netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
1660			     __func__, session, skcb->addr.sa, skcb->addr.da,
1661			     session->last_cmd);
1662
1663		j1939_session_timers_cancel(session);
1664		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
1665
1666		return -EBUSY;
1667	}
1668
1669	if (session->skcb.addr.sa != skcb->addr.sa ||
1670	    session->skcb.addr.da != skcb->addr.da)
1671		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",
1672			    __func__, session,
1673			    session->skcb.addr.sa, skcb->addr.sa,
1674			    session->skcb.addr.da, skcb->addr.da);
1675	/* make sure 'sa' & 'da' are correct !
1676	 * They may be 'not filled in yet' for sending
1677	 * skb's, since they did not pass the Address Claim ever.
1678	 */
1679	session->skcb.addr.sa = skcb->addr.sa;
1680	session->skcb.addr.da = skcb->addr.da;
1681
1682	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1683
1684	return 0;
1685}
1686
1687static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
1688			     bool transmitter)
1689{
1690	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1691	struct j1939_session *session;
1692	u8 cmd = skb->data[0];
1693
1694	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1695					    transmitter);
1696
1697	if (!session) {
1698		if (transmitter) {
1699			/* If we're the transmitter and this function is called,
1700			 * we received our own RTS. A session has already been
1701			 * created.
1702			 *
1703			 * For some reasons however it might have been destroyed
1704			 * already. So don't create a new one here (using
1705			 * "j1939_xtp_rx_rts_session_new()") as this will be a
1706			 * receiver session.
1707			 *
1708			 * The reasons the session is already destroyed might
1709			 * be:
1710			 * - user space closed socket was and the session was
1711			 *   aborted
1712			 * - session was aborted due to external abort message
1713			 */
1714			return;
1715		}
1716		session = j1939_xtp_rx_rts_session_new(priv, skb);
1717		if (!session) {
1718			if (cmd == J1939_TP_CMD_BAM && j1939_sk_recv_match(priv, skcb))
1719				netdev_info(priv->ndev, "%s: failed to create TP BAM session\n",
1720					    __func__);
1721			return;
1722		}
1723	} else {
1724		if (j1939_xtp_rx_rts_session_active(session, skb)) {
1725			j1939_session_put(session);
1726			return;
1727		}
1728	}
1729	session->last_cmd = cmd;
1730
1731	if (cmd == J1939_TP_CMD_BAM) {
1732		if (!session->transmission)
1733			j1939_tp_set_rxtimeout(session, 750);
1734	} else {
1735		if (!session->transmission) {
1736			j1939_session_txtimer_cancel(session);
1737			j1939_tp_schedule_txtimer(session, 0);
1738		}
1739		j1939_tp_set_rxtimeout(session, 1250);
1740	}
1741
1742	j1939_session_put(session);
1743}
1744
1745static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
1746				 struct sk_buff *skb)
1747{
1748	const u8 *dat = skb->data;
1749
1750	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
1751		return;
1752
1753	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
1754
1755	/* transmitted without problems */
1756	session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
1757	session->last_cmd = dat[0];
1758	j1939_tp_set_rxtimeout(session, 750);
1759}
1760
1761static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
1762			     bool transmitter)
1763{
1764	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1765	struct j1939_session *session;
1766
1767	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1768					    transmitter);
1769	if (!session) {
1770		netdev_info(priv->ndev,
1771			    "%s: no connection found\n", __func__);
1772		return;
1773	}
1774
1775	j1939_xtp_rx_dpo_one(session, skb);
1776	j1939_session_put(session);
1777}
1778
1779static void j1939_xtp_rx_dat_one(struct j1939_session *session,
1780				 struct sk_buff *skb)
1781{
1782	enum j1939_xtp_abort abort = J1939_XTP_ABORT_FAULT;
1783	struct j1939_priv *priv = session->priv;
1784	struct j1939_sk_buff_cb *skcb;
1785	struct sk_buff *se_skb = NULL;
1786	const u8 *dat;
1787	u8 *tpdat;
1788	int offset;
1789	int nbytes;
1790	bool final = false;
1791	bool remain = false;
1792	bool do_cts_eoma = false;
1793	int packet;
1794
1795	skcb = j1939_skb_to_cb(skb);
1796	dat = skb->data;
1797	if (skb->len != 8) {
1798		/* makes no sense */
1799		abort = J1939_XTP_ABORT_UNEXPECTED_DATA;
1800		goto out_session_cancel;
1801	}
1802
1803	switch (session->last_cmd) {
1804	case 0xff:
1805		break;
1806	case J1939_ETP_CMD_DPO:
1807		if (skcb->addr.type == J1939_ETP)
1808			break;
1809		fallthrough;
1810	case J1939_TP_CMD_BAM:
1811	case J1939_TP_CMD_CTS: /* fall through */
1812		if (skcb->addr.type != J1939_ETP)
1813			break;
1814		fallthrough;
1815	default:
1816		netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
1817			    session, session->last_cmd);
1818		goto out_session_cancel;
1819	}
1820
1821	packet = (dat[0] - 1 + session->pkt.dpo);
1822	if (packet > session->pkt.total ||
1823	    (session->pkt.rx + 1) > session->pkt.total) {
1824		netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
1825			    __func__, session);
1826		goto out_session_cancel;
1827	}
1828
1829	se_skb = j1939_session_skb_get_by_offset(session, packet * 7);
1830	if (!se_skb) {
1831		netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
1832			    session);
1833		goto out_session_cancel;
1834	}
1835
1836	skcb = j1939_skb_to_cb(se_skb);
1837	offset = packet * 7 - skcb->offset;
1838	nbytes = se_skb->len - offset;
1839	if (nbytes > 7)
1840		nbytes = 7;
1841	if (nbytes <= 0 || (nbytes + 1) > skb->len) {
1842		netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
1843			    __func__, session, nbytes, skb->len);
1844		goto out_session_cancel;
1845	}
1846
1847	tpdat = se_skb->data;
1848	if (!session->transmission) {
1849		memcpy(&tpdat[offset], &dat[1], nbytes);
1850	} else {
1851		int err;
1852
1853		err = memcmp(&tpdat[offset], &dat[1], nbytes);
1854		if (err)
1855			netdev_err_once(priv->ndev,
1856					"%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n",
1857					__func__, session,
1858					nbytes, &dat[1],
1859					nbytes, &tpdat[offset]);
1860	}
1861
1862	if (packet == session->pkt.rx)
1863		session->pkt.rx++;
1864
1865	if (skcb->addr.type != J1939_ETP &&
1866	    j1939_cb_is_broadcast(&session->skcb)) {
1867		if (session->pkt.rx >= session->pkt.total)
1868			final = true;
1869		else
1870			remain = true;
1871	} else {
1872		/* never final, an EOMA must follow */
1873		if (session->pkt.rx >= session->pkt.last)
1874			do_cts_eoma = true;
1875	}
1876
1877	if (final) {
1878		j1939_session_timers_cancel(session);
1879		j1939_session_completed(session);
1880	} else if (remain) {
1881		if (!session->transmission)
1882			j1939_tp_set_rxtimeout(session, 750);
1883	} else if (do_cts_eoma) {
1884		j1939_tp_set_rxtimeout(session, 1250);
1885		if (!session->transmission)
1886			j1939_tp_schedule_txtimer(session, 0);
1887	} else {
1888		j1939_tp_set_rxtimeout(session, 750);
1889	}
1890	session->last_cmd = 0xff;
1891	consume_skb(se_skb);
1892	j1939_session_put(session);
1893
1894	return;
1895
1896 out_session_cancel:
1897	kfree_skb(se_skb);
1898	j1939_session_timers_cancel(session);
1899	j1939_session_cancel(session, abort);
1900	j1939_session_put(session);
1901}
1902
1903static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
1904{
1905	struct j1939_sk_buff_cb *skcb;
1906	struct j1939_session *session;
1907
1908	skcb = j1939_skb_to_cb(skb);
1909
1910	if (j1939_tp_im_transmitter(skcb)) {
1911		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1912						    true);
1913		if (!session)
1914			netdev_info(priv->ndev, "%s: no tx connection found\n",
1915				    __func__);
1916		else
1917			j1939_xtp_rx_dat_one(session, skb);
1918	}
1919
1920	if (j1939_tp_im_receiver(skcb)) {
1921		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1922						    false);
1923		if (!session)
1924			netdev_info(priv->ndev, "%s: no rx connection found\n",
1925				    __func__);
1926		else
1927			j1939_xtp_rx_dat_one(session, skb);
1928	}
1929
1930	if (j1939_cb_is_broadcast(skcb)) {
1931		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
1932						    false);
1933		if (session)
1934			j1939_xtp_rx_dat_one(session, skb);
1935	}
1936}
1937
1938/* j1939 main intf */
1939struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
1940				    struct sk_buff *skb, size_t size)
1941{
1942	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
1943	struct j1939_session *session;
1944	int ret;
1945
1946	if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
1947	    skcb->addr.pgn == J1939_TP_PGN_CTL ||
1948	    skcb->addr.pgn == J1939_ETP_PGN_DAT ||
1949	    skcb->addr.pgn == J1939_ETP_PGN_CTL)
1950		/* avoid conflict */
1951		return ERR_PTR(-EDOM);
1952
1953	if (size > priv->tp_max_packet_size)
1954		return ERR_PTR(-EMSGSIZE);
1955
1956	if (size <= 8)
1957		skcb->addr.type = J1939_SIMPLE;
1958	else if (size > J1939_MAX_TP_PACKET_SIZE)
1959		skcb->addr.type = J1939_ETP;
1960	else
1961		skcb->addr.type = J1939_TP;
1962
1963	if (skcb->addr.type == J1939_ETP &&
1964	    j1939_cb_is_broadcast(skcb))
1965		return ERR_PTR(-EDESTADDRREQ);
1966
1967	/* fill in addresses from names */
1968	ret = j1939_ac_fixup(priv, skb);
1969	if (unlikely(ret))
1970		return ERR_PTR(ret);
1971
1972	/* fix DST flags, it may be used there soon */
1973	if (j1939_address_is_unicast(skcb->addr.da) &&
1974	    priv->ents[skcb->addr.da].nusers)
1975		skcb->flags |= J1939_ECU_LOCAL_DST;
1976
1977	/* src is always local, I'm sending ... */
1978	skcb->flags |= J1939_ECU_LOCAL_SRC;
1979
1980	/* prepare new session */
1981	session = j1939_session_new(priv, skb, size);
1982	if (!session)
1983		return ERR_PTR(-ENOMEM);
1984
1985	/* skb is recounted in j1939_session_new() */
1986	sock_hold(skb->sk);
1987	session->sk = skb->sk;
1988	session->transmission = true;
1989	session->pkt.total = (size + 6) / 7;
1990	session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
1991		min(j1939_tp_block ?: 255, session->pkt.total);
1992
1993	if (j1939_cb_is_broadcast(&session->skcb))
1994		/* set the end-packet for broadcast */
1995		session->pkt.last = session->pkt.total;
1996
1997	skcb->tskey = session->sk->sk_tskey++;
1998	session->tskey = skcb->tskey;
1999
2000	return session;
2001}
2002
2003static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
2004{
2005	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
2006	int extd = J1939_TP;
2007	u8 cmd = skb->data[0];
2008
2009	switch (cmd) {
2010	case J1939_ETP_CMD_RTS:
2011		extd = J1939_ETP;
2012		fallthrough;
2013	case J1939_TP_CMD_BAM:
2014		if (cmd == J1939_TP_CMD_BAM && !j1939_cb_is_broadcast(skcb)) {
2015			netdev_err_once(priv->ndev, "%s: BAM to unicast (%02x), ignoring!\n",
2016					__func__, skcb->addr.sa);
2017			return;
2018		}
2019		fallthrough;
2020	case J1939_TP_CMD_RTS: /* fall through */
2021		if (skcb->addr.type != extd)
2022			return;
2023
2024		if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
2025			netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
2026				     __func__, skcb->addr.sa);
2027			return;
2028		}
2029
2030		if (j1939_tp_im_transmitter(skcb))
2031			j1939_xtp_rx_rts(priv, skb, true);
2032
2033		if (j1939_tp_im_receiver(skcb) || j1939_cb_is_broadcast(skcb))
2034			j1939_xtp_rx_rts(priv, skb, false);
2035
2036		break;
2037
2038	case J1939_ETP_CMD_CTS:
2039		extd = J1939_ETP;
2040		fallthrough;
2041	case J1939_TP_CMD_CTS:
2042		if (skcb->addr.type != extd)
2043			return;
2044
2045		if (j1939_tp_im_transmitter(skcb))
2046			j1939_xtp_rx_cts(priv, skb, false);
2047
2048		if (j1939_tp_im_receiver(skcb))
2049			j1939_xtp_rx_cts(priv, skb, true);
2050
2051		break;
2052
2053	case J1939_ETP_CMD_DPO:
2054		if (skcb->addr.type != J1939_ETP)
2055			return;
2056
2057		if (j1939_tp_im_transmitter(skcb))
2058			j1939_xtp_rx_dpo(priv, skb, true);
2059
2060		if (j1939_tp_im_receiver(skcb))
2061			j1939_xtp_rx_dpo(priv, skb, false);
2062
2063		break;
2064
2065	case J1939_ETP_CMD_EOMA:
2066		extd = J1939_ETP;
2067		fallthrough;
2068	case J1939_TP_CMD_EOMA:
2069		if (skcb->addr.type != extd)
2070			return;
2071
2072		if (j1939_tp_im_transmitter(skcb))
2073			j1939_xtp_rx_eoma(priv, skb, false);
2074
2075		if (j1939_tp_im_receiver(skcb))
2076			j1939_xtp_rx_eoma(priv, skb, true);
2077
2078		break;
2079
2080	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
2081		if (j1939_cb_is_broadcast(skcb)) {
2082			netdev_err_once(priv->ndev, "%s: abort to broadcast (%02x), ignoring!\n",
2083					__func__, skcb->addr.sa);
2084			return;
2085		}
2086
2087		if (j1939_tp_im_transmitter(skcb))
2088			j1939_xtp_rx_abort(priv, skb, true);
2089
2090		if (j1939_tp_im_receiver(skcb))
2091			j1939_xtp_rx_abort(priv, skb, false);
2092
2093		break;
2094	default:
2095		return;
2096	}
2097}
2098
2099int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
2100{
2101	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
2102
2103	if (!j1939_tp_im_involved_anydir(skcb) && !j1939_cb_is_broadcast(skcb))
2104		return 0;
2105
2106	switch (skcb->addr.pgn) {
2107	case J1939_ETP_PGN_DAT:
2108		skcb->addr.type = J1939_ETP;
2109		fallthrough;
2110	case J1939_TP_PGN_DAT:
2111		j1939_xtp_rx_dat(priv, skb);
2112		break;
2113
2114	case J1939_ETP_PGN_CTL:
2115		skcb->addr.type = J1939_ETP;
2116		fallthrough;
2117	case J1939_TP_PGN_CTL:
2118		if (skb->len < 8)
2119			return 0; /* Don't care. Nothing to extract here */
2120
2121		j1939_tp_cmd_recv(priv, skb);
2122		break;
2123	default:
2124		return 0; /* no problem */
2125	}
2126	return 1; /* "I processed the message" */
2127}
2128
2129void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
2130{
2131	struct j1939_session *session;
2132
2133	if (!skb->sk)
2134		return;
2135
2136	if (skb->sk->sk_family != AF_CAN ||
2137	    skb->sk->sk_protocol != CAN_J1939)
2138		return;
2139
2140	j1939_session_list_lock(priv);
2141	session = j1939_session_get_simple(priv, skb);
2142	j1939_session_list_unlock(priv);
2143	if (!session) {
2144		netdev_warn(priv->ndev,
2145			    "%s: Received already invalidated message\n",
2146			    __func__);
2147		return;
2148	}
2149
2150	j1939_session_timers_cancel(session);
2151	j1939_session_deactivate(session);
2152	j1939_session_put(session);
2153}
2154
2155int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
2156{
2157	struct j1939_session *session, *saved;
2158
2159	netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
2160	j1939_session_list_lock(priv);
2161	list_for_each_entry_safe(session, saved,
2162				 &priv->active_session_list,
2163				 active_session_list_entry) {
2164		if (!sk || sk == session->sk) {
2165			if (hrtimer_try_to_cancel(&session->txtimer) == 1)
2166				j1939_session_put(session);
2167			if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
2168				j1939_session_put(session);
2169
2170			session->err = ESHUTDOWN;
2171			j1939_session_deactivate_locked(session);
2172		}
2173	}
2174	j1939_session_list_unlock(priv);
2175	return NOTIFY_DONE;
2176}
2177
2178void j1939_tp_init(struct j1939_priv *priv)
2179{
2180	spin_lock_init(&priv->active_session_list_lock);
2181	INIT_LIST_HEAD(&priv->active_session_list);
2182	priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
2183}
2184