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1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2/* isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
3 *
4 * This implementation does not provide ISO-TP specific return values to the
5 * userspace.
6 *
7 * - RX path timeout of data reception leads to -ETIMEDOUT
8 * - RX path SN mismatch leads to -EILSEQ
9 * - RX path data reception with wrong padding leads to -EBADMSG
10 * - TX path flowcontrol reception timeout leads to -ECOMM
11 * - TX path flowcontrol reception overflow leads to -EMSGSIZE
12 * - TX path flowcontrol reception with wrong layout/padding leads to -EBADMSG
13 * - when a transfer (tx) is on the run the next write() blocks until it's done
14 * - use CAN_ISOTP_WAIT_TX_DONE flag to block the caller until the PDU is sent
15 * - as we have static buffers the check whether the PDU fits into the buffer
16 * is done at FF reception time (no support for sending 'wait frames')
17 *
18 * Copyright (c) 2020 Volkswagen Group Electronic Research
19 * All rights reserved.
20 *
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
23 * are met:
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
29 * 3. Neither the name of Volkswagen nor the names of its contributors
30 * may be used to endorse or promote products derived from this software
31 * without specific prior written permission.
32 *
33 * Alternatively, provided that this notice is retained in full, this
34 * software may be distributed under the terms of the GNU General
35 * Public License ("GPL") version 2, in which case the provisions of the
36 * GPL apply INSTEAD OF those given above.
37 *
38 * The provided data structures and external interfaces from this code
39 * are not restricted to be used by modules with a GPL compatible license.
40 *
41 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
42 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
43 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
44 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
45 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
48 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
49 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
50 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
51 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
52 * DAMAGE.
53 */
54
55#include <linux/module.h>
56#include <linux/init.h>
57#include <linux/interrupt.h>
58#include <linux/spinlock.h>
59#include <linux/hrtimer.h>
60#include <linux/wait.h>
61#include <linux/uio.h>
62#include <linux/net.h>
63#include <linux/netdevice.h>
64#include <linux/socket.h>
65#include <linux/if_arp.h>
66#include <linux/skbuff.h>
67#include <linux/can.h>
68#include <linux/can/core.h>
69#include <linux/can/skb.h>
70#include <linux/can/isotp.h>
71#include <linux/slab.h>
72#include <net/sock.h>
73#include <net/net_namespace.h>
74
75MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
76MODULE_LICENSE("Dual BSD/GPL");
77MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
78MODULE_ALIAS("can-proto-6");
79
80#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
81
82#define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
83 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
84 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
85
86/* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
87 * take full 32 bit values (4 Gbyte). We would need some good concept to handle
88 * this between user space and kernel space. For now increase the static buffer
89 * to something about 64 kbyte to be able to test this new functionality.
90 */
91#define MAX_MSG_LENGTH 66000
92
93/* N_PCI type values in bits 7-4 of N_PCI bytes */
94#define N_PCI_SF 0x00 /* single frame */
95#define N_PCI_FF 0x10 /* first frame */
96#define N_PCI_CF 0x20 /* consecutive frame */
97#define N_PCI_FC 0x30 /* flow control */
98
99#define N_PCI_SZ 1 /* size of the PCI byte #1 */
100#define SF_PCI_SZ4 1 /* size of SingleFrame PCI including 4 bit SF_DL */
101#define SF_PCI_SZ8 2 /* size of SingleFrame PCI including 8 bit SF_DL */
102#define FF_PCI_SZ12 2 /* size of FirstFrame PCI including 12 bit FF_DL */
103#define FF_PCI_SZ32 6 /* size of FirstFrame PCI including 32 bit FF_DL */
104#define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
105
106#define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
107#define ISOTP_ALL_BC_FLAGS (CAN_ISOTP_SF_BROADCAST | CAN_ISOTP_CF_BROADCAST)
108
109/* Flow Status given in FC frame */
110#define ISOTP_FC_CTS 0 /* clear to send */
111#define ISOTP_FC_WT 1 /* wait */
112#define ISOTP_FC_OVFLW 2 /* overflow */
113
114#define ISOTP_FC_TIMEOUT 1 /* 1 sec */
115#define ISOTP_ECHO_TIMEOUT 2 /* 2 secs */
116
117enum {
118 ISOTP_IDLE = 0,
119 ISOTP_WAIT_FIRST_FC,
120 ISOTP_WAIT_FC,
121 ISOTP_WAIT_DATA,
122 ISOTP_SENDING
123};
124
125struct tpcon {
126 unsigned int idx;
127 unsigned int len;
128 u32 state;
129 u8 bs;
130 u8 sn;
131 u8 ll_dl;
132 u8 buf[MAX_MSG_LENGTH + 1];
133};
134
135struct isotp_sock {
136 struct sock sk;
137 int bound;
138 int ifindex;
139 canid_t txid;
140 canid_t rxid;
141 ktime_t tx_gap;
142 ktime_t lastrxcf_tstamp;
143 struct hrtimer rxtimer, txtimer, txfrtimer;
144 struct can_isotp_options opt;
145 struct can_isotp_fc_options rxfc, txfc;
146 struct can_isotp_ll_options ll;
147 u32 frame_txtime;
148 u32 force_tx_stmin;
149 u32 force_rx_stmin;
150 u32 cfecho; /* consecutive frame echo tag */
151 struct tpcon rx, tx;
152 struct list_head notifier;
153 wait_queue_head_t wait;
154 spinlock_t rx_lock; /* protect single thread state machine */
155};
156
157static LIST_HEAD(isotp_notifier_list);
158static DEFINE_SPINLOCK(isotp_notifier_lock);
159static struct isotp_sock *isotp_busy_notifier;
160
161static inline struct isotp_sock *isotp_sk(const struct sock *sk)
162{
163 return (struct isotp_sock *)sk;
164}
165
166static u32 isotp_bc_flags(struct isotp_sock *so)
167{
168 return so->opt.flags & ISOTP_ALL_BC_FLAGS;
169}
170
171static bool isotp_register_rxid(struct isotp_sock *so)
172{
173 /* no broadcast modes => register rx_id for FC frame reception */
174 return (isotp_bc_flags(so) == 0);
175}
176
177static bool isotp_register_txecho(struct isotp_sock *so)
178{
179 /* all modes but SF_BROADCAST register for tx echo skbs */
180 return (isotp_bc_flags(so) != CAN_ISOTP_SF_BROADCAST);
181}
182
183static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
184{
185 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
186 rxtimer);
187 struct sock *sk = &so->sk;
188
189 if (so->rx.state == ISOTP_WAIT_DATA) {
190 /* we did not get new data frames in time */
191
192 /* report 'connection timed out' */
193 sk->sk_err = ETIMEDOUT;
194 if (!sock_flag(sk, SOCK_DEAD))
195 sk_error_report(sk);
196
197 /* reset rx state */
198 so->rx.state = ISOTP_IDLE;
199 }
200
201 return HRTIMER_NORESTART;
202}
203
204static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
205{
206 struct net_device *dev;
207 struct sk_buff *nskb;
208 struct canfd_frame *ncf;
209 struct isotp_sock *so = isotp_sk(sk);
210 int can_send_ret;
211
212 nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
213 if (!nskb)
214 return 1;
215
216 dev = dev_get_by_index(sock_net(sk), so->ifindex);
217 if (!dev) {
218 kfree_skb(nskb);
219 return 1;
220 }
221
222 can_skb_reserve(nskb);
223 can_skb_prv(nskb)->ifindex = dev->ifindex;
224 can_skb_prv(nskb)->skbcnt = 0;
225
226 nskb->dev = dev;
227 can_skb_set_owner(nskb, sk);
228 ncf = (struct canfd_frame *)nskb->data;
229 skb_put_zero(nskb, so->ll.mtu);
230
231 /* create & send flow control reply */
232 ncf->can_id = so->txid;
233
234 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
235 memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
236 ncf->len = CAN_MAX_DLEN;
237 } else {
238 ncf->len = ae + FC_CONTENT_SZ;
239 }
240
241 ncf->data[ae] = N_PCI_FC | flowstatus;
242 ncf->data[ae + 1] = so->rxfc.bs;
243 ncf->data[ae + 2] = so->rxfc.stmin;
244
245 if (ae)
246 ncf->data[0] = so->opt.ext_address;
247
248 ncf->flags = so->ll.tx_flags;
249
250 can_send_ret = can_send(nskb, 1);
251 if (can_send_ret)
252 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
253 __func__, ERR_PTR(can_send_ret));
254
255 dev_put(dev);
256
257 /* reset blocksize counter */
258 so->rx.bs = 0;
259
260 /* reset last CF frame rx timestamp for rx stmin enforcement */
261 so->lastrxcf_tstamp = ktime_set(0, 0);
262
263 /* start rx timeout watchdog */
264 hrtimer_start(&so->rxtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
265 HRTIMER_MODE_REL_SOFT);
266 return 0;
267}
268
269static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
270{
271 struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
272
273 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
274
275 memset(addr, 0, sizeof(*addr));
276 addr->can_family = AF_CAN;
277 addr->can_ifindex = skb->dev->ifindex;
278
279 if (sock_queue_rcv_skb(sk, skb) < 0)
280 kfree_skb(skb);
281}
282
283static u8 padlen(u8 datalen)
284{
285 static const u8 plen[] = {
286 8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
287 12, 12, 12, 12, /* 9 - 12 */
288 16, 16, 16, 16, /* 13 - 16 */
289 20, 20, 20, 20, /* 17 - 20 */
290 24, 24, 24, 24, /* 21 - 24 */
291 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
292 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
293 48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
294 };
295
296 if (datalen > 48)
297 return 64;
298
299 return plen[datalen];
300}
301
302/* check for length optimization and return 1/true when the check fails */
303static int check_optimized(struct canfd_frame *cf, int start_index)
304{
305 /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
306 * padding would start at this point. E.g. if the padding would
307 * start at cf.data[7] cf->len has to be 7 to be optimal.
308 * Note: The data[] index starts with zero.
309 */
310 if (cf->len <= CAN_MAX_DLEN)
311 return (cf->len != start_index);
312
313 /* This relation is also valid in the non-linear DLC range, where
314 * we need to take care of the minimal next possible CAN_DL.
315 * The correct check would be (padlen(cf->len) != padlen(start_index)).
316 * But as cf->len can only take discrete values from 12, .., 64 at this
317 * point the padlen(cf->len) is always equal to cf->len.
318 */
319 return (cf->len != padlen(start_index));
320}
321
322/* check padding and return 1/true when the check fails */
323static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
324 int start_index, u8 content)
325{
326 int i;
327
328 /* no RX_PADDING value => check length of optimized frame length */
329 if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
330 if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
331 return check_optimized(cf, start_index);
332
333 /* no valid test against empty value => ignore frame */
334 return 1;
335 }
336
337 /* check datalength of correctly padded CAN frame */
338 if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
339 cf->len != padlen(cf->len))
340 return 1;
341
342 /* check padding content */
343 if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
344 for (i = start_index; i < cf->len; i++)
345 if (cf->data[i] != content)
346 return 1;
347 }
348 return 0;
349}
350
351static void isotp_send_cframe(struct isotp_sock *so);
352
353static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
354{
355 struct sock *sk = &so->sk;
356
357 if (so->tx.state != ISOTP_WAIT_FC &&
358 so->tx.state != ISOTP_WAIT_FIRST_FC)
359 return 0;
360
361 hrtimer_cancel(&so->txtimer);
362
363 if ((cf->len < ae + FC_CONTENT_SZ) ||
364 ((so->opt.flags & ISOTP_CHECK_PADDING) &&
365 check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
366 /* malformed PDU - report 'not a data message' */
367 sk->sk_err = EBADMSG;
368 if (!sock_flag(sk, SOCK_DEAD))
369 sk_error_report(sk);
370
371 so->tx.state = ISOTP_IDLE;
372 wake_up_interruptible(&so->wait);
373 return 1;
374 }
375
376 /* get communication parameters only from the first FC frame */
377 if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
378 so->txfc.bs = cf->data[ae + 1];
379 so->txfc.stmin = cf->data[ae + 2];
380
381 /* fix wrong STmin values according spec */
382 if (so->txfc.stmin > 0x7F &&
383 (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
384 so->txfc.stmin = 0x7F;
385
386 so->tx_gap = ktime_set(0, 0);
387 /* add transmission time for CAN frame N_As */
388 so->tx_gap = ktime_add_ns(so->tx_gap, so->frame_txtime);
389 /* add waiting time for consecutive frames N_Cs */
390 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
391 so->tx_gap = ktime_add_ns(so->tx_gap,
392 so->force_tx_stmin);
393 else if (so->txfc.stmin < 0x80)
394 so->tx_gap = ktime_add_ns(so->tx_gap,
395 so->txfc.stmin * 1000000);
396 else
397 so->tx_gap = ktime_add_ns(so->tx_gap,
398 (so->txfc.stmin - 0xF0)
399 * 100000);
400 so->tx.state = ISOTP_WAIT_FC;
401 }
402
403 switch (cf->data[ae] & 0x0F) {
404 case ISOTP_FC_CTS:
405 so->tx.bs = 0;
406 so->tx.state = ISOTP_SENDING;
407 /* send CF frame and enable echo timeout handling */
408 hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
409 HRTIMER_MODE_REL_SOFT);
410 isotp_send_cframe(so);
411 break;
412
413 case ISOTP_FC_WT:
414 /* start timer to wait for next FC frame */
415 hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
416 HRTIMER_MODE_REL_SOFT);
417 break;
418
419 case ISOTP_FC_OVFLW:
420 /* overflow on receiver side - report 'message too long' */
421 sk->sk_err = EMSGSIZE;
422 if (!sock_flag(sk, SOCK_DEAD))
423 sk_error_report(sk);
424 fallthrough;
425
426 default:
427 /* stop this tx job */
428 so->tx.state = ISOTP_IDLE;
429 wake_up_interruptible(&so->wait);
430 }
431 return 0;
432}
433
434static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
435 struct sk_buff *skb, int len)
436{
437 struct isotp_sock *so = isotp_sk(sk);
438 struct sk_buff *nskb;
439
440 hrtimer_cancel(&so->rxtimer);
441 so->rx.state = ISOTP_IDLE;
442
443 if (!len || len > cf->len - pcilen)
444 return 1;
445
446 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
447 check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
448 /* malformed PDU - report 'not a data message' */
449 sk->sk_err = EBADMSG;
450 if (!sock_flag(sk, SOCK_DEAD))
451 sk_error_report(sk);
452 return 1;
453 }
454
455 nskb = alloc_skb(len, gfp_any());
456 if (!nskb)
457 return 1;
458
459 memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
460
461 nskb->tstamp = skb->tstamp;
462 nskb->dev = skb->dev;
463 isotp_rcv_skb(nskb, sk);
464 return 0;
465}
466
467static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
468{
469 struct isotp_sock *so = isotp_sk(sk);
470 int i;
471 int off;
472 int ff_pci_sz;
473
474 hrtimer_cancel(&so->rxtimer);
475 so->rx.state = ISOTP_IDLE;
476
477 /* get the used sender LL_DL from the (first) CAN frame data length */
478 so->rx.ll_dl = padlen(cf->len);
479
480 /* the first frame has to use the entire frame up to LL_DL length */
481 if (cf->len != so->rx.ll_dl)
482 return 1;
483
484 /* get the FF_DL */
485 so->rx.len = (cf->data[ae] & 0x0F) << 8;
486 so->rx.len += cf->data[ae + 1];
487
488 /* Check for FF_DL escape sequence supporting 32 bit PDU length */
489 if (so->rx.len) {
490 ff_pci_sz = FF_PCI_SZ12;
491 } else {
492 /* FF_DL = 0 => get real length from next 4 bytes */
493 so->rx.len = cf->data[ae + 2] << 24;
494 so->rx.len += cf->data[ae + 3] << 16;
495 so->rx.len += cf->data[ae + 4] << 8;
496 so->rx.len += cf->data[ae + 5];
497 ff_pci_sz = FF_PCI_SZ32;
498 }
499
500 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
501 off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
502
503 if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
504 return 1;
505
506 if (so->rx.len > MAX_MSG_LENGTH) {
507 /* send FC frame with overflow status */
508 isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
509 return 1;
510 }
511
512 /* copy the first received data bytes */
513 so->rx.idx = 0;
514 for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
515 so->rx.buf[so->rx.idx++] = cf->data[i];
516
517 /* initial setup for this pdu reception */
518 so->rx.sn = 1;
519 so->rx.state = ISOTP_WAIT_DATA;
520
521 /* no creation of flow control frames */
522 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
523 return 0;
524
525 /* send our first FC frame */
526 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
527 return 0;
528}
529
530static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
531 struct sk_buff *skb)
532{
533 struct isotp_sock *so = isotp_sk(sk);
534 struct sk_buff *nskb;
535 int i;
536
537 if (so->rx.state != ISOTP_WAIT_DATA)
538 return 0;
539
540 /* drop if timestamp gap is less than force_rx_stmin nano secs */
541 if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
542 if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
543 so->force_rx_stmin)
544 return 0;
545
546 so->lastrxcf_tstamp = skb->tstamp;
547 }
548
549 hrtimer_cancel(&so->rxtimer);
550
551 /* CFs are never longer than the FF */
552 if (cf->len > so->rx.ll_dl)
553 return 1;
554
555 /* CFs have usually the LL_DL length */
556 if (cf->len < so->rx.ll_dl) {
557 /* this is only allowed for the last CF */
558 if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
559 return 1;
560 }
561
562 if ((cf->data[ae] & 0x0F) != so->rx.sn) {
563 /* wrong sn detected - report 'illegal byte sequence' */
564 sk->sk_err = EILSEQ;
565 if (!sock_flag(sk, SOCK_DEAD))
566 sk_error_report(sk);
567
568 /* reset rx state */
569 so->rx.state = ISOTP_IDLE;
570 return 1;
571 }
572 so->rx.sn++;
573 so->rx.sn %= 16;
574
575 for (i = ae + N_PCI_SZ; i < cf->len; i++) {
576 so->rx.buf[so->rx.idx++] = cf->data[i];
577 if (so->rx.idx >= so->rx.len)
578 break;
579 }
580
581 if (so->rx.idx >= so->rx.len) {
582 /* we are done */
583 so->rx.state = ISOTP_IDLE;
584
585 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
586 check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
587 /* malformed PDU - report 'not a data message' */
588 sk->sk_err = EBADMSG;
589 if (!sock_flag(sk, SOCK_DEAD))
590 sk_error_report(sk);
591 return 1;
592 }
593
594 nskb = alloc_skb(so->rx.len, gfp_any());
595 if (!nskb)
596 return 1;
597
598 memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
599 so->rx.len);
600
601 nskb->tstamp = skb->tstamp;
602 nskb->dev = skb->dev;
603 isotp_rcv_skb(nskb, sk);
604 return 0;
605 }
606
607 /* perform blocksize handling, if enabled */
608 if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
609 /* start rx timeout watchdog */
610 hrtimer_start(&so->rxtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
611 HRTIMER_MODE_REL_SOFT);
612 return 0;
613 }
614
615 /* no creation of flow control frames */
616 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
617 return 0;
618
619 /* we reached the specified blocksize so->rxfc.bs */
620 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
621 return 0;
622}
623
624static void isotp_rcv(struct sk_buff *skb, void *data)
625{
626 struct sock *sk = (struct sock *)data;
627 struct isotp_sock *so = isotp_sk(sk);
628 struct canfd_frame *cf;
629 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
630 u8 n_pci_type, sf_dl;
631
632 /* Strictly receive only frames with the configured MTU size
633 * => clear separation of CAN2.0 / CAN FD transport channels
634 */
635 if (skb->len != so->ll.mtu)
636 return;
637
638 cf = (struct canfd_frame *)skb->data;
639
640 /* if enabled: check reception of my configured extended address */
641 if (ae && cf->data[0] != so->opt.rx_ext_address)
642 return;
643
644 n_pci_type = cf->data[ae] & 0xF0;
645
646 /* Make sure the state changes and data structures stay consistent at
647 * CAN frame reception time. This locking is not needed in real world
648 * use cases but the inconsistency can be triggered with syzkaller.
649 */
650 spin_lock(&so->rx_lock);
651
652 if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
653 /* check rx/tx path half duplex expectations */
654 if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
655 (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
656 goto out_unlock;
657 }
658
659 switch (n_pci_type) {
660 case N_PCI_FC:
661 /* tx path: flow control frame containing the FC parameters */
662 isotp_rcv_fc(so, cf, ae);
663 break;
664
665 case N_PCI_SF:
666 /* rx path: single frame
667 *
668 * As we do not have a rx.ll_dl configuration, we can only test
669 * if the CAN frames payload length matches the LL_DL == 8
670 * requirements - no matter if it's CAN 2.0 or CAN FD
671 */
672
673 /* get the SF_DL from the N_PCI byte */
674 sf_dl = cf->data[ae] & 0x0F;
675
676 if (cf->len <= CAN_MAX_DLEN) {
677 isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
678 } else {
679 if (can_is_canfd_skb(skb)) {
680 /* We have a CAN FD frame and CAN_DL is greater than 8:
681 * Only frames with the SF_DL == 0 ESC value are valid.
682 *
683 * If so take care of the increased SF PCI size
684 * (SF_PCI_SZ8) to point to the message content behind
685 * the extended SF PCI info and get the real SF_DL
686 * length value from the formerly first data byte.
687 */
688 if (sf_dl == 0)
689 isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
690 cf->data[SF_PCI_SZ4 + ae]);
691 }
692 }
693 break;
694
695 case N_PCI_FF:
696 /* rx path: first frame */
697 isotp_rcv_ff(sk, cf, ae);
698 break;
699
700 case N_PCI_CF:
701 /* rx path: consecutive frame */
702 isotp_rcv_cf(sk, cf, ae, skb);
703 break;
704 }
705
706out_unlock:
707 spin_unlock(&so->rx_lock);
708}
709
710static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
711 int ae, int off)
712{
713 int pcilen = N_PCI_SZ + ae + off;
714 int space = so->tx.ll_dl - pcilen;
715 int num = min_t(int, so->tx.len - so->tx.idx, space);
716 int i;
717
718 cf->can_id = so->txid;
719 cf->len = num + pcilen;
720
721 if (num < space) {
722 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
723 /* user requested padding */
724 cf->len = padlen(cf->len);
725 memset(cf->data, so->opt.txpad_content, cf->len);
726 } else if (cf->len > CAN_MAX_DLEN) {
727 /* mandatory padding for CAN FD frames */
728 cf->len = padlen(cf->len);
729 memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
730 cf->len);
731 }
732 }
733
734 for (i = 0; i < num; i++)
735 cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
736
737 if (ae)
738 cf->data[0] = so->opt.ext_address;
739}
740
741static void isotp_send_cframe(struct isotp_sock *so)
742{
743 struct sock *sk = &so->sk;
744 struct sk_buff *skb;
745 struct net_device *dev;
746 struct canfd_frame *cf;
747 int can_send_ret;
748 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
749
750 dev = dev_get_by_index(sock_net(sk), so->ifindex);
751 if (!dev)
752 return;
753
754 skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), GFP_ATOMIC);
755 if (!skb) {
756 dev_put(dev);
757 return;
758 }
759
760 can_skb_reserve(skb);
761 can_skb_prv(skb)->ifindex = dev->ifindex;
762 can_skb_prv(skb)->skbcnt = 0;
763
764 cf = (struct canfd_frame *)skb->data;
765 skb_put_zero(skb, so->ll.mtu);
766
767 /* create consecutive frame */
768 isotp_fill_dataframe(cf, so, ae, 0);
769
770 /* place consecutive frame N_PCI in appropriate index */
771 cf->data[ae] = N_PCI_CF | so->tx.sn++;
772 so->tx.sn %= 16;
773 so->tx.bs++;
774
775 cf->flags = so->ll.tx_flags;
776
777 skb->dev = dev;
778 can_skb_set_owner(skb, sk);
779
780 /* cfecho should have been zero'ed by init/isotp_rcv_echo() */
781 if (so->cfecho)
782 pr_notice_once("can-isotp: cfecho is %08X != 0\n", so->cfecho);
783
784 /* set consecutive frame echo tag */
785 so->cfecho = *(u32 *)cf->data;
786
787 /* send frame with local echo enabled */
788 can_send_ret = can_send(skb, 1);
789 if (can_send_ret) {
790 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
791 __func__, ERR_PTR(can_send_ret));
792 if (can_send_ret == -ENOBUFS)
793 pr_notice_once("can-isotp: tx queue is full\n");
794 }
795 dev_put(dev);
796}
797
798static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
799 int ae)
800{
801 int i;
802 int ff_pci_sz;
803
804 cf->can_id = so->txid;
805 cf->len = so->tx.ll_dl;
806 if (ae)
807 cf->data[0] = so->opt.ext_address;
808
809 /* create N_PCI bytes with 12/32 bit FF_DL data length */
810 if (so->tx.len > 4095) {
811 /* use 32 bit FF_DL notation */
812 cf->data[ae] = N_PCI_FF;
813 cf->data[ae + 1] = 0;
814 cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
815 cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
816 cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
817 cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
818 ff_pci_sz = FF_PCI_SZ32;
819 } else {
820 /* use 12 bit FF_DL notation */
821 cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
822 cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
823 ff_pci_sz = FF_PCI_SZ12;
824 }
825
826 /* add first data bytes depending on ae */
827 for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
828 cf->data[i] = so->tx.buf[so->tx.idx++];
829
830 so->tx.sn = 1;
831}
832
833static void isotp_rcv_echo(struct sk_buff *skb, void *data)
834{
835 struct sock *sk = (struct sock *)data;
836 struct isotp_sock *so = isotp_sk(sk);
837 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
838
839 /* only handle my own local echo CF/SF skb's (no FF!) */
840 if (skb->sk != sk || so->cfecho != *(u32 *)cf->data)
841 return;
842
843 /* cancel local echo timeout */
844 hrtimer_cancel(&so->txtimer);
845
846 /* local echo skb with consecutive frame has been consumed */
847 so->cfecho = 0;
848
849 if (so->tx.idx >= so->tx.len) {
850 /* we are done */
851 so->tx.state = ISOTP_IDLE;
852 wake_up_interruptible(&so->wait);
853 return;
854 }
855
856 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
857 /* stop and wait for FC with timeout */
858 so->tx.state = ISOTP_WAIT_FC;
859 hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
860 HRTIMER_MODE_REL_SOFT);
861 return;
862 }
863
864 /* no gap between data frames needed => use burst mode */
865 if (!so->tx_gap) {
866 /* enable echo timeout handling */
867 hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
868 HRTIMER_MODE_REL_SOFT);
869 isotp_send_cframe(so);
870 return;
871 }
872
873 /* start timer to send next consecutive frame with correct delay */
874 hrtimer_start(&so->txfrtimer, so->tx_gap, HRTIMER_MODE_REL_SOFT);
875}
876
877static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
878{
879 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
880 txtimer);
881 struct sock *sk = &so->sk;
882
883 /* don't handle timeouts in IDLE state */
884 if (so->tx.state == ISOTP_IDLE)
885 return HRTIMER_NORESTART;
886
887 /* we did not get any flow control or echo frame in time */
888
889 /* report 'communication error on send' */
890 sk->sk_err = ECOMM;
891 if (!sock_flag(sk, SOCK_DEAD))
892 sk_error_report(sk);
893
894 /* reset tx state */
895 so->tx.state = ISOTP_IDLE;
896 wake_up_interruptible(&so->wait);
897
898 return HRTIMER_NORESTART;
899}
900
901static enum hrtimer_restart isotp_txfr_timer_handler(struct hrtimer *hrtimer)
902{
903 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
904 txfrtimer);
905
906 /* start echo timeout handling and cover below protocol error */
907 hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
908 HRTIMER_MODE_REL_SOFT);
909
910 /* cfecho should be consumed by isotp_rcv_echo() here */
911 if (so->tx.state == ISOTP_SENDING && !so->cfecho)
912 isotp_send_cframe(so);
913
914 return HRTIMER_NORESTART;
915}
916
917static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
918{
919 struct sock *sk = sock->sk;
920 struct isotp_sock *so = isotp_sk(sk);
921 u32 old_state = so->tx.state;
922 struct sk_buff *skb;
923 struct net_device *dev;
924 struct canfd_frame *cf;
925 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
926 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
927 s64 hrtimer_sec = ISOTP_ECHO_TIMEOUT;
928 int off;
929 int err;
930
931 if (!so->bound)
932 return -EADDRNOTAVAIL;
933
934 /* we do not support multiple buffers - for now */
935 if (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE ||
936 wq_has_sleeper(&so->wait)) {
937 if (msg->msg_flags & MSG_DONTWAIT) {
938 err = -EAGAIN;
939 goto err_out;
940 }
941
942 /* wait for complete transmission of current pdu */
943 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
944 if (err)
945 goto err_out;
946
947 so->tx.state = ISOTP_SENDING;
948 }
949
950 if (!size || size > MAX_MSG_LENGTH) {
951 err = -EINVAL;
952 goto err_out_drop;
953 }
954
955 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
956 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
957
958 /* does the given data fit into a single frame for SF_BROADCAST? */
959 if ((isotp_bc_flags(so) == CAN_ISOTP_SF_BROADCAST) &&
960 (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
961 err = -EINVAL;
962 goto err_out_drop;
963 }
964
965 err = memcpy_from_msg(so->tx.buf, msg, size);
966 if (err < 0)
967 goto err_out_drop;
968
969 dev = dev_get_by_index(sock_net(sk), so->ifindex);
970 if (!dev) {
971 err = -ENXIO;
972 goto err_out_drop;
973 }
974
975 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
976 msg->msg_flags & MSG_DONTWAIT, &err);
977 if (!skb) {
978 dev_put(dev);
979 goto err_out_drop;
980 }
981
982 can_skb_reserve(skb);
983 can_skb_prv(skb)->ifindex = dev->ifindex;
984 can_skb_prv(skb)->skbcnt = 0;
985
986 so->tx.len = size;
987 so->tx.idx = 0;
988
989 cf = (struct canfd_frame *)skb->data;
990 skb_put_zero(skb, so->ll.mtu);
991
992 /* cfecho should have been zero'ed by init / former isotp_rcv_echo() */
993 if (so->cfecho)
994 pr_notice_once("can-isotp: uninit cfecho %08X\n", so->cfecho);
995
996 /* check for single frame transmission depending on TX_DL */
997 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
998 /* The message size generally fits into a SingleFrame - good.
999 *
1000 * SF_DL ESC offset optimization:
1001 *
1002 * When TX_DL is greater 8 but the message would still fit
1003 * into a 8 byte CAN frame, we can omit the offset.
1004 * This prevents a protocol caused length extension from
1005 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
1006 */
1007 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
1008 off = 0;
1009
1010 isotp_fill_dataframe(cf, so, ae, off);
1011
1012 /* place single frame N_PCI w/o length in appropriate index */
1013 cf->data[ae] = N_PCI_SF;
1014
1015 /* place SF_DL size value depending on the SF_DL ESC offset */
1016 if (off)
1017 cf->data[SF_PCI_SZ4 + ae] = size;
1018 else
1019 cf->data[ae] |= size;
1020
1021 /* set CF echo tag for isotp_rcv_echo() (SF-mode) */
1022 so->cfecho = *(u32 *)cf->data;
1023 } else {
1024 /* send first frame */
1025
1026 isotp_create_fframe(cf, so, ae);
1027
1028 if (isotp_bc_flags(so) == CAN_ISOTP_CF_BROADCAST) {
1029 /* set timer for FC-less operation (STmin = 0) */
1030 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
1031 so->tx_gap = ktime_set(0, so->force_tx_stmin);
1032 else
1033 so->tx_gap = ktime_set(0, so->frame_txtime);
1034
1035 /* disable wait for FCs due to activated block size */
1036 so->txfc.bs = 0;
1037
1038 /* set CF echo tag for isotp_rcv_echo() (CF-mode) */
1039 so->cfecho = *(u32 *)cf->data;
1040 } else {
1041 /* standard flow control check */
1042 so->tx.state = ISOTP_WAIT_FIRST_FC;
1043
1044 /* start timeout for FC */
1045 hrtimer_sec = ISOTP_FC_TIMEOUT;
1046
1047 /* no CF echo tag for isotp_rcv_echo() (FF-mode) */
1048 so->cfecho = 0;
1049 }
1050 }
1051
1052 hrtimer_start(&so->txtimer, ktime_set(hrtimer_sec, 0),
1053 HRTIMER_MODE_REL_SOFT);
1054
1055 /* send the first or only CAN frame */
1056 cf->flags = so->ll.tx_flags;
1057
1058 skb->dev = dev;
1059 skb->sk = sk;
1060 err = can_send(skb, 1);
1061 dev_put(dev);
1062 if (err) {
1063 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
1064 __func__, ERR_PTR(err));
1065
1066 /* no transmission -> no timeout monitoring */
1067 hrtimer_cancel(&so->txtimer);
1068
1069 /* reset consecutive frame echo tag */
1070 so->cfecho = 0;
1071
1072 goto err_out_drop;
1073 }
1074
1075 if (wait_tx_done) {
1076 /* wait for complete transmission of current pdu */
1077 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1078
1079 if (sk->sk_err)
1080 return -sk->sk_err;
1081 }
1082
1083 return size;
1084
1085err_out_drop:
1086 /* drop this PDU and unlock a potential wait queue */
1087 old_state = ISOTP_IDLE;
1088err_out:
1089 so->tx.state = old_state;
1090 if (so->tx.state == ISOTP_IDLE)
1091 wake_up_interruptible(&so->wait);
1092
1093 return err;
1094}
1095
1096static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1097 int flags)
1098{
1099 struct sock *sk = sock->sk;
1100 struct sk_buff *skb;
1101 struct isotp_sock *so = isotp_sk(sk);
1102 int ret = 0;
1103
1104 if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK))
1105 return -EINVAL;
1106
1107 if (!so->bound)
1108 return -EADDRNOTAVAIL;
1109
1110 skb = skb_recv_datagram(sk, flags, &ret);
1111 if (!skb)
1112 return ret;
1113
1114 if (size < skb->len)
1115 msg->msg_flags |= MSG_TRUNC;
1116 else
1117 size = skb->len;
1118
1119 ret = memcpy_to_msg(msg, skb->data, size);
1120 if (ret < 0)
1121 goto out_err;
1122
1123 sock_recv_timestamp(msg, sk, skb);
1124
1125 if (msg->msg_name) {
1126 __sockaddr_check_size(ISOTP_MIN_NAMELEN);
1127 msg->msg_namelen = ISOTP_MIN_NAMELEN;
1128 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1129 }
1130
1131 /* set length of return value */
1132 ret = (flags & MSG_TRUNC) ? skb->len : size;
1133
1134out_err:
1135 skb_free_datagram(sk, skb);
1136
1137 return ret;
1138}
1139
1140static int isotp_release(struct socket *sock)
1141{
1142 struct sock *sk = sock->sk;
1143 struct isotp_sock *so;
1144 struct net *net;
1145
1146 if (!sk)
1147 return 0;
1148
1149 so = isotp_sk(sk);
1150 net = sock_net(sk);
1151
1152 /* wait for complete transmission of current pdu */
1153 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1154
1155 /* force state machines to be idle also when a signal occurred */
1156 so->tx.state = ISOTP_IDLE;
1157 so->rx.state = ISOTP_IDLE;
1158
1159 spin_lock(&isotp_notifier_lock);
1160 while (isotp_busy_notifier == so) {
1161 spin_unlock(&isotp_notifier_lock);
1162 schedule_timeout_uninterruptible(1);
1163 spin_lock(&isotp_notifier_lock);
1164 }
1165 list_del(&so->notifier);
1166 spin_unlock(&isotp_notifier_lock);
1167
1168 lock_sock(sk);
1169
1170 /* remove current filters & unregister */
1171 if (so->bound && isotp_register_txecho(so)) {
1172 if (so->ifindex) {
1173 struct net_device *dev;
1174
1175 dev = dev_get_by_index(net, so->ifindex);
1176 if (dev) {
1177 if (isotp_register_rxid(so))
1178 can_rx_unregister(net, dev, so->rxid,
1179 SINGLE_MASK(so->rxid),
1180 isotp_rcv, sk);
1181
1182 can_rx_unregister(net, dev, so->txid,
1183 SINGLE_MASK(so->txid),
1184 isotp_rcv_echo, sk);
1185 dev_put(dev);
1186 synchronize_rcu();
1187 }
1188 }
1189 }
1190
1191 hrtimer_cancel(&so->txfrtimer);
1192 hrtimer_cancel(&so->txtimer);
1193 hrtimer_cancel(&so->rxtimer);
1194
1195 so->ifindex = 0;
1196 so->bound = 0;
1197
1198 sock_orphan(sk);
1199 sock->sk = NULL;
1200
1201 release_sock(sk);
1202 sock_put(sk);
1203
1204 return 0;
1205}
1206
1207static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1208{
1209 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1210 struct sock *sk = sock->sk;
1211 struct isotp_sock *so = isotp_sk(sk);
1212 struct net *net = sock_net(sk);
1213 int ifindex;
1214 struct net_device *dev;
1215 canid_t tx_id = addr->can_addr.tp.tx_id;
1216 canid_t rx_id = addr->can_addr.tp.rx_id;
1217 int err = 0;
1218 int notify_enetdown = 0;
1219
1220 if (len < ISOTP_MIN_NAMELEN)
1221 return -EINVAL;
1222
1223 /* sanitize tx CAN identifier */
1224 if (tx_id & CAN_EFF_FLAG)
1225 tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1226 else
1227 tx_id &= CAN_SFF_MASK;
1228
1229 /* give feedback on wrong CAN-ID value */
1230 if (tx_id != addr->can_addr.tp.tx_id)
1231 return -EINVAL;
1232
1233 /* sanitize rx CAN identifier (if needed) */
1234 if (isotp_register_rxid(so)) {
1235 if (rx_id & CAN_EFF_FLAG)
1236 rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1237 else
1238 rx_id &= CAN_SFF_MASK;
1239
1240 /* give feedback on wrong CAN-ID value */
1241 if (rx_id != addr->can_addr.tp.rx_id)
1242 return -EINVAL;
1243 }
1244
1245 if (!addr->can_ifindex)
1246 return -ENODEV;
1247
1248 lock_sock(sk);
1249
1250 if (so->bound) {
1251 err = -EINVAL;
1252 goto out;
1253 }
1254
1255 /* ensure different CAN IDs when the rx_id is to be registered */
1256 if (isotp_register_rxid(so) && rx_id == tx_id) {
1257 err = -EADDRNOTAVAIL;
1258 goto out;
1259 }
1260
1261 dev = dev_get_by_index(net, addr->can_ifindex);
1262 if (!dev) {
1263 err = -ENODEV;
1264 goto out;
1265 }
1266 if (dev->type != ARPHRD_CAN) {
1267 dev_put(dev);
1268 err = -ENODEV;
1269 goto out;
1270 }
1271 if (dev->mtu < so->ll.mtu) {
1272 dev_put(dev);
1273 err = -EINVAL;
1274 goto out;
1275 }
1276 if (!(dev->flags & IFF_UP))
1277 notify_enetdown = 1;
1278
1279 ifindex = dev->ifindex;
1280
1281 if (isotp_register_rxid(so))
1282 can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
1283 isotp_rcv, sk, "isotp", sk);
1284
1285 if (isotp_register_txecho(so)) {
1286 /* no consecutive frame echo skb in flight */
1287 so->cfecho = 0;
1288
1289 /* register for echo skb's */
1290 can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
1291 isotp_rcv_echo, sk, "isotpe", sk);
1292 }
1293
1294 dev_put(dev);
1295
1296 /* switch to new settings */
1297 so->ifindex = ifindex;
1298 so->rxid = rx_id;
1299 so->txid = tx_id;
1300 so->bound = 1;
1301
1302out:
1303 release_sock(sk);
1304
1305 if (notify_enetdown) {
1306 sk->sk_err = ENETDOWN;
1307 if (!sock_flag(sk, SOCK_DEAD))
1308 sk_error_report(sk);
1309 }
1310
1311 return err;
1312}
1313
1314static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1315{
1316 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1317 struct sock *sk = sock->sk;
1318 struct isotp_sock *so = isotp_sk(sk);
1319
1320 if (peer)
1321 return -EOPNOTSUPP;
1322
1323 memset(addr, 0, ISOTP_MIN_NAMELEN);
1324 addr->can_family = AF_CAN;
1325 addr->can_ifindex = so->ifindex;
1326 addr->can_addr.tp.rx_id = so->rxid;
1327 addr->can_addr.tp.tx_id = so->txid;
1328
1329 return ISOTP_MIN_NAMELEN;
1330}
1331
1332static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
1333 sockptr_t optval, unsigned int optlen)
1334{
1335 struct sock *sk = sock->sk;
1336 struct isotp_sock *so = isotp_sk(sk);
1337 int ret = 0;
1338
1339 if (so->bound)
1340 return -EISCONN;
1341
1342 switch (optname) {
1343 case CAN_ISOTP_OPTS:
1344 if (optlen != sizeof(struct can_isotp_options))
1345 return -EINVAL;
1346
1347 if (copy_from_sockptr(&so->opt, optval, optlen))
1348 return -EFAULT;
1349
1350 /* no separate rx_ext_address is given => use ext_address */
1351 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1352 so->opt.rx_ext_address = so->opt.ext_address;
1353
1354 /* these broadcast flags are not allowed together */
1355 if (isotp_bc_flags(so) == ISOTP_ALL_BC_FLAGS) {
1356 /* CAN_ISOTP_SF_BROADCAST is prioritized */
1357 so->opt.flags &= ~CAN_ISOTP_CF_BROADCAST;
1358
1359 /* give user feedback on wrong config attempt */
1360 ret = -EINVAL;
1361 }
1362
1363 /* check for frame_txtime changes (0 => no changes) */
1364 if (so->opt.frame_txtime) {
1365 if (so->opt.frame_txtime == CAN_ISOTP_FRAME_TXTIME_ZERO)
1366 so->frame_txtime = 0;
1367 else
1368 so->frame_txtime = so->opt.frame_txtime;
1369 }
1370 break;
1371
1372 case CAN_ISOTP_RECV_FC:
1373 if (optlen != sizeof(struct can_isotp_fc_options))
1374 return -EINVAL;
1375
1376 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1377 return -EFAULT;
1378 break;
1379
1380 case CAN_ISOTP_TX_STMIN:
1381 if (optlen != sizeof(u32))
1382 return -EINVAL;
1383
1384 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1385 return -EFAULT;
1386 break;
1387
1388 case CAN_ISOTP_RX_STMIN:
1389 if (optlen != sizeof(u32))
1390 return -EINVAL;
1391
1392 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1393 return -EFAULT;
1394 break;
1395
1396 case CAN_ISOTP_LL_OPTS:
1397 if (optlen == sizeof(struct can_isotp_ll_options)) {
1398 struct can_isotp_ll_options ll;
1399
1400 if (copy_from_sockptr(&ll, optval, optlen))
1401 return -EFAULT;
1402
1403 /* check for correct ISO 11898-1 DLC data length */
1404 if (ll.tx_dl != padlen(ll.tx_dl))
1405 return -EINVAL;
1406
1407 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1408 return -EINVAL;
1409
1410 if (ll.mtu == CAN_MTU &&
1411 (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1412 return -EINVAL;
1413
1414 memcpy(&so->ll, &ll, sizeof(ll));
1415
1416 /* set ll_dl for tx path to similar place as for rx */
1417 so->tx.ll_dl = ll.tx_dl;
1418 } else {
1419 return -EINVAL;
1420 }
1421 break;
1422
1423 default:
1424 ret = -ENOPROTOOPT;
1425 }
1426
1427 return ret;
1428}
1429
1430static int isotp_setsockopt(struct socket *sock, int level, int optname,
1431 sockptr_t optval, unsigned int optlen)
1432
1433{
1434 struct sock *sk = sock->sk;
1435 int ret;
1436
1437 if (level != SOL_CAN_ISOTP)
1438 return -EINVAL;
1439
1440 lock_sock(sk);
1441 ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
1442 release_sock(sk);
1443 return ret;
1444}
1445
1446static int isotp_getsockopt(struct socket *sock, int level, int optname,
1447 char __user *optval, int __user *optlen)
1448{
1449 struct sock *sk = sock->sk;
1450 struct isotp_sock *so = isotp_sk(sk);
1451 int len;
1452 void *val;
1453
1454 if (level != SOL_CAN_ISOTP)
1455 return -EINVAL;
1456 if (get_user(len, optlen))
1457 return -EFAULT;
1458 if (len < 0)
1459 return -EINVAL;
1460
1461 switch (optname) {
1462 case CAN_ISOTP_OPTS:
1463 len = min_t(int, len, sizeof(struct can_isotp_options));
1464 val = &so->opt;
1465 break;
1466
1467 case CAN_ISOTP_RECV_FC:
1468 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1469 val = &so->rxfc;
1470 break;
1471
1472 case CAN_ISOTP_TX_STMIN:
1473 len = min_t(int, len, sizeof(u32));
1474 val = &so->force_tx_stmin;
1475 break;
1476
1477 case CAN_ISOTP_RX_STMIN:
1478 len = min_t(int, len, sizeof(u32));
1479 val = &so->force_rx_stmin;
1480 break;
1481
1482 case CAN_ISOTP_LL_OPTS:
1483 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1484 val = &so->ll;
1485 break;
1486
1487 default:
1488 return -ENOPROTOOPT;
1489 }
1490
1491 if (put_user(len, optlen))
1492 return -EFAULT;
1493 if (copy_to_user(optval, val, len))
1494 return -EFAULT;
1495 return 0;
1496}
1497
1498static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1499 struct net_device *dev)
1500{
1501 struct sock *sk = &so->sk;
1502
1503 if (!net_eq(dev_net(dev), sock_net(sk)))
1504 return;
1505
1506 if (so->ifindex != dev->ifindex)
1507 return;
1508
1509 switch (msg) {
1510 case NETDEV_UNREGISTER:
1511 lock_sock(sk);
1512 /* remove current filters & unregister */
1513 if (so->bound && isotp_register_txecho(so)) {
1514 if (isotp_register_rxid(so))
1515 can_rx_unregister(dev_net(dev), dev, so->rxid,
1516 SINGLE_MASK(so->rxid),
1517 isotp_rcv, sk);
1518
1519 can_rx_unregister(dev_net(dev), dev, so->txid,
1520 SINGLE_MASK(so->txid),
1521 isotp_rcv_echo, sk);
1522 }
1523
1524 so->ifindex = 0;
1525 so->bound = 0;
1526 release_sock(sk);
1527
1528 sk->sk_err = ENODEV;
1529 if (!sock_flag(sk, SOCK_DEAD))
1530 sk_error_report(sk);
1531 break;
1532
1533 case NETDEV_DOWN:
1534 sk->sk_err = ENETDOWN;
1535 if (!sock_flag(sk, SOCK_DEAD))
1536 sk_error_report(sk);
1537 break;
1538 }
1539}
1540
1541static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1542 void *ptr)
1543{
1544 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1545
1546 if (dev->type != ARPHRD_CAN)
1547 return NOTIFY_DONE;
1548 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1549 return NOTIFY_DONE;
1550 if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1551 return NOTIFY_DONE;
1552
1553 spin_lock(&isotp_notifier_lock);
1554 list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1555 spin_unlock(&isotp_notifier_lock);
1556 isotp_notify(isotp_busy_notifier, msg, dev);
1557 spin_lock(&isotp_notifier_lock);
1558 }
1559 isotp_busy_notifier = NULL;
1560 spin_unlock(&isotp_notifier_lock);
1561 return NOTIFY_DONE;
1562}
1563
1564static int isotp_init(struct sock *sk)
1565{
1566 struct isotp_sock *so = isotp_sk(sk);
1567
1568 so->ifindex = 0;
1569 so->bound = 0;
1570
1571 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1572 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1573 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1574 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1575 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1576 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1577 so->frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1578 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1579 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1580 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1581 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1582 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1583 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1584
1585 /* set ll_dl for tx path to similar place as for rx */
1586 so->tx.ll_dl = so->ll.tx_dl;
1587
1588 so->rx.state = ISOTP_IDLE;
1589 so->tx.state = ISOTP_IDLE;
1590
1591 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1592 so->rxtimer.function = isotp_rx_timer_handler;
1593 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1594 so->txtimer.function = isotp_tx_timer_handler;
1595 hrtimer_init(&so->txfrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1596 so->txfrtimer.function = isotp_txfr_timer_handler;
1597
1598 init_waitqueue_head(&so->wait);
1599 spin_lock_init(&so->rx_lock);
1600
1601 spin_lock(&isotp_notifier_lock);
1602 list_add_tail(&so->notifier, &isotp_notifier_list);
1603 spin_unlock(&isotp_notifier_lock);
1604
1605 return 0;
1606}
1607
1608static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1609 unsigned long arg)
1610{
1611 /* no ioctls for socket layer -> hand it down to NIC layer */
1612 return -ENOIOCTLCMD;
1613}
1614
1615static const struct proto_ops isotp_ops = {
1616 .family = PF_CAN,
1617 .release = isotp_release,
1618 .bind = isotp_bind,
1619 .connect = sock_no_connect,
1620 .socketpair = sock_no_socketpair,
1621 .accept = sock_no_accept,
1622 .getname = isotp_getname,
1623 .poll = datagram_poll,
1624 .ioctl = isotp_sock_no_ioctlcmd,
1625 .gettstamp = sock_gettstamp,
1626 .listen = sock_no_listen,
1627 .shutdown = sock_no_shutdown,
1628 .setsockopt = isotp_setsockopt,
1629 .getsockopt = isotp_getsockopt,
1630 .sendmsg = isotp_sendmsg,
1631 .recvmsg = isotp_recvmsg,
1632 .mmap = sock_no_mmap,
1633 .sendpage = sock_no_sendpage,
1634};
1635
1636static struct proto isotp_proto __read_mostly = {
1637 .name = "CAN_ISOTP",
1638 .owner = THIS_MODULE,
1639 .obj_size = sizeof(struct isotp_sock),
1640 .init = isotp_init,
1641};
1642
1643static const struct can_proto isotp_can_proto = {
1644 .type = SOCK_DGRAM,
1645 .protocol = CAN_ISOTP,
1646 .ops = &isotp_ops,
1647 .prot = &isotp_proto,
1648};
1649
1650static struct notifier_block canisotp_notifier = {
1651 .notifier_call = isotp_notifier
1652};
1653
1654static __init int isotp_module_init(void)
1655{
1656 int err;
1657
1658 pr_info("can: isotp protocol\n");
1659
1660 err = can_proto_register(&isotp_can_proto);
1661 if (err < 0)
1662 pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
1663 else
1664 register_netdevice_notifier(&canisotp_notifier);
1665
1666 return err;
1667}
1668
1669static __exit void isotp_module_exit(void)
1670{
1671 can_proto_unregister(&isotp_can_proto);
1672 unregister_netdevice_notifier(&canisotp_notifier);
1673}
1674
1675module_init(isotp_module_init);
1676module_exit(isotp_module_exit);