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 * - take care of the tx-queue-len as traffic shaping is still on the TODO list
18 *
19 * Copyright (c) 2020 Volkswagen Group Electronic Research
20 * All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. Neither the name of Volkswagen nor the names of its contributors
31 * may be used to endorse or promote products derived from this software
32 * without specific prior written permission.
33 *
34 * Alternatively, provided that this notice is retained in full, this
35 * software may be distributed under the terms of the GNU General
36 * Public License ("GPL") version 2, in which case the provisions of the
37 * GPL apply INSTEAD OF those given above.
38 *
39 * The provided data structures and external interfaces from this code
40 * are not restricted to be used by modules with a GPL compatible license.
41 *
42 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
43 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
44 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
45 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
46 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
47 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
48 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
49 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
50 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
51 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
52 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
53 * DAMAGE.
54 */
55
56 #include <linux/module.h>
57 #include <linux/init.h>
58 #include <linux/interrupt.h>
59 #include <linux/spinlock.h>
60 #include <linux/hrtimer.h>
61 #include <linux/wait.h>
62 #include <linux/uio.h>
63 #include <linux/net.h>
64 #include <linux/netdevice.h>
65 #include <linux/socket.h>
66 #include <linux/if_arp.h>
67 #include <linux/skbuff.h>
68 #include <linux/can.h>
69 #include <linux/can/core.h>
70 #include <linux/can/skb.h>
71 #include <linux/can/isotp.h>
72 #include <linux/slab.h>
73 #include <net/sock.h>
74 #include <net/net_namespace.h>
75
76 MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
77 MODULE_LICENSE("Dual BSD/GPL");
78 MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
79 MODULE_ALIAS("can-proto-6");
80
81 #define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
82
83 #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
84 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
85 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
86
87 /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
88 * take full 32 bit values (4 Gbyte). We would need some good concept to handle
89 * this between user space and kernel space. For now increase the static buffer
90 * to something about 8 kbyte to be able to test this new functionality.
91 */
92 #define MAX_MSG_LENGTH 8200
93
94 /* N_PCI type values in bits 7-4 of N_PCI bytes */
95 #define N_PCI_SF 0x00 /* single frame */
96 #define N_PCI_FF 0x10 /* first frame */
97 #define N_PCI_CF 0x20 /* consecutive frame */
98 #define N_PCI_FC 0x30 /* flow control */
99
100 #define N_PCI_SZ 1 /* size of the PCI byte #1 */
101 #define SF_PCI_SZ4 1 /* size of SingleFrame PCI including 4 bit SF_DL */
102 #define SF_PCI_SZ8 2 /* size of SingleFrame PCI including 8 bit SF_DL */
103 #define FF_PCI_SZ12 2 /* size of FirstFrame PCI including 12 bit FF_DL */
104 #define FF_PCI_SZ32 6 /* size of FirstFrame PCI including 32 bit FF_DL */
105 #define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
106
107 #define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
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 enum {
115 ISOTP_IDLE = 0,
116 ISOTP_WAIT_FIRST_FC,
117 ISOTP_WAIT_FC,
118 ISOTP_WAIT_DATA,
119 ISOTP_SENDING
120 };
121
122 struct tpcon {
123 unsigned int idx;
124 unsigned int len;
125 u32 state;
126 u8 bs;
127 u8 sn;
128 u8 ll_dl;
129 u8 buf[MAX_MSG_LENGTH + 1];
130 };
131
132 struct isotp_sock {
133 struct sock sk;
134 int bound;
135 int ifindex;
136 canid_t txid;
137 canid_t rxid;
138 ktime_t tx_gap;
139 ktime_t lastrxcf_tstamp;
140 struct hrtimer rxtimer, txtimer;
141 struct can_isotp_options opt;
142 struct can_isotp_fc_options rxfc, txfc;
143 struct can_isotp_ll_options ll;
144 u32 frame_txtime;
145 u32 force_tx_stmin;
146 u32 force_rx_stmin;
147 struct tpcon rx, tx;
148 struct list_head notifier;
149 wait_queue_head_t wait;
150 spinlock_t rx_lock; /* protect single thread state machine */
151 };
152
153 static LIST_HEAD(isotp_notifier_list);
154 static DEFINE_SPINLOCK(isotp_notifier_lock);
155 static struct isotp_sock *isotp_busy_notifier;
156
isotp_sk(const struct sock * sk)157 static inline struct isotp_sock *isotp_sk(const struct sock *sk)
158 {
159 return (struct isotp_sock *)sk;
160 }
161
isotp_rx_timer_handler(struct hrtimer * hrtimer)162 static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
163 {
164 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
165 rxtimer);
166 struct sock *sk = &so->sk;
167
168 if (so->rx.state == ISOTP_WAIT_DATA) {
169 /* we did not get new data frames in time */
170
171 /* report 'connection timed out' */
172 sk->sk_err = ETIMEDOUT;
173 if (!sock_flag(sk, SOCK_DEAD))
174 sk->sk_error_report(sk);
175
176 /* reset rx state */
177 so->rx.state = ISOTP_IDLE;
178 }
179
180 return HRTIMER_NORESTART;
181 }
182
isotp_send_fc(struct sock * sk,int ae,u8 flowstatus)183 static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
184 {
185 struct net_device *dev;
186 struct sk_buff *nskb;
187 struct canfd_frame *ncf;
188 struct isotp_sock *so = isotp_sk(sk);
189 int can_send_ret;
190
191 nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
192 if (!nskb)
193 return 1;
194
195 dev = dev_get_by_index(sock_net(sk), so->ifindex);
196 if (!dev) {
197 kfree_skb(nskb);
198 return 1;
199 }
200
201 can_skb_reserve(nskb);
202 can_skb_prv(nskb)->ifindex = dev->ifindex;
203 can_skb_prv(nskb)->skbcnt = 0;
204
205 nskb->dev = dev;
206 can_skb_set_owner(nskb, sk);
207 ncf = (struct canfd_frame *)nskb->data;
208 skb_put_zero(nskb, so->ll.mtu);
209
210 /* create & send flow control reply */
211 ncf->can_id = so->txid;
212
213 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
214 memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
215 ncf->len = CAN_MAX_DLEN;
216 } else {
217 ncf->len = ae + FC_CONTENT_SZ;
218 }
219
220 ncf->data[ae] = N_PCI_FC | flowstatus;
221 ncf->data[ae + 1] = so->rxfc.bs;
222 ncf->data[ae + 2] = so->rxfc.stmin;
223
224 if (ae)
225 ncf->data[0] = so->opt.ext_address;
226
227 ncf->flags = so->ll.tx_flags;
228
229 can_send_ret = can_send(nskb, 1);
230 if (can_send_ret)
231 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
232 __func__, can_send_ret);
233
234 dev_put(dev);
235
236 /* reset blocksize counter */
237 so->rx.bs = 0;
238
239 /* reset last CF frame rx timestamp for rx stmin enforcement */
240 so->lastrxcf_tstamp = ktime_set(0, 0);
241
242 /* start rx timeout watchdog */
243 hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
244 return 0;
245 }
246
isotp_rcv_skb(struct sk_buff * skb,struct sock * sk)247 static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
248 {
249 struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
250
251 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
252
253 memset(addr, 0, sizeof(*addr));
254 addr->can_family = AF_CAN;
255 addr->can_ifindex = skb->dev->ifindex;
256
257 if (sock_queue_rcv_skb(sk, skb) < 0)
258 kfree_skb(skb);
259 }
260
padlen(u8 datalen)261 static u8 padlen(u8 datalen)
262 {
263 static const u8 plen[] = {
264 8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
265 12, 12, 12, 12, /* 9 - 12 */
266 16, 16, 16, 16, /* 13 - 16 */
267 20, 20, 20, 20, /* 17 - 20 */
268 24, 24, 24, 24, /* 21 - 24 */
269 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
270 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
271 48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
272 };
273
274 if (datalen > 48)
275 return 64;
276
277 return plen[datalen];
278 }
279
280 /* check for length optimization and return 1/true when the check fails */
check_optimized(struct canfd_frame * cf,int start_index)281 static int check_optimized(struct canfd_frame *cf, int start_index)
282 {
283 /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
284 * padding would start at this point. E.g. if the padding would
285 * start at cf.data[7] cf->len has to be 7 to be optimal.
286 * Note: The data[] index starts with zero.
287 */
288 if (cf->len <= CAN_MAX_DLEN)
289 return (cf->len != start_index);
290
291 /* This relation is also valid in the non-linear DLC range, where
292 * we need to take care of the minimal next possible CAN_DL.
293 * The correct check would be (padlen(cf->len) != padlen(start_index)).
294 * But as cf->len can only take discrete values from 12, .., 64 at this
295 * point the padlen(cf->len) is always equal to cf->len.
296 */
297 return (cf->len != padlen(start_index));
298 }
299
300 /* check padding and return 1/true when the check fails */
check_pad(struct isotp_sock * so,struct canfd_frame * cf,int start_index,u8 content)301 static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
302 int start_index, u8 content)
303 {
304 int i;
305
306 /* no RX_PADDING value => check length of optimized frame length */
307 if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
308 if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
309 return check_optimized(cf, start_index);
310
311 /* no valid test against empty value => ignore frame */
312 return 1;
313 }
314
315 /* check datalength of correctly padded CAN frame */
316 if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
317 cf->len != padlen(cf->len))
318 return 1;
319
320 /* check padding content */
321 if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
322 for (i = start_index; i < cf->len; i++)
323 if (cf->data[i] != content)
324 return 1;
325 }
326 return 0;
327 }
328
isotp_rcv_fc(struct isotp_sock * so,struct canfd_frame * cf,int ae)329 static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
330 {
331 struct sock *sk = &so->sk;
332
333 if (so->tx.state != ISOTP_WAIT_FC &&
334 so->tx.state != ISOTP_WAIT_FIRST_FC)
335 return 0;
336
337 hrtimer_cancel(&so->txtimer);
338
339 if ((cf->len < ae + FC_CONTENT_SZ) ||
340 ((so->opt.flags & ISOTP_CHECK_PADDING) &&
341 check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
342 /* malformed PDU - report 'not a data message' */
343 sk->sk_err = EBADMSG;
344 if (!sock_flag(sk, SOCK_DEAD))
345 sk->sk_error_report(sk);
346
347 so->tx.state = ISOTP_IDLE;
348 wake_up_interruptible(&so->wait);
349 return 1;
350 }
351
352 /* get communication parameters only from the first FC frame */
353 if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
354 so->txfc.bs = cf->data[ae + 1];
355 so->txfc.stmin = cf->data[ae + 2];
356
357 /* fix wrong STmin values according spec */
358 if (so->txfc.stmin > 0x7F &&
359 (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
360 so->txfc.stmin = 0x7F;
361
362 so->tx_gap = ktime_set(0, 0);
363 /* add transmission time for CAN frame N_As */
364 so->tx_gap = ktime_add_ns(so->tx_gap, so->frame_txtime);
365 /* add waiting time for consecutive frames N_Cs */
366 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
367 so->tx_gap = ktime_add_ns(so->tx_gap,
368 so->force_tx_stmin);
369 else if (so->txfc.stmin < 0x80)
370 so->tx_gap = ktime_add_ns(so->tx_gap,
371 so->txfc.stmin * 1000000);
372 else
373 so->tx_gap = ktime_add_ns(so->tx_gap,
374 (so->txfc.stmin - 0xF0)
375 * 100000);
376 so->tx.state = ISOTP_WAIT_FC;
377 }
378
379 switch (cf->data[ae] & 0x0F) {
380 case ISOTP_FC_CTS:
381 so->tx.bs = 0;
382 so->tx.state = ISOTP_SENDING;
383 /* start cyclic timer for sending CF frame */
384 hrtimer_start(&so->txtimer, so->tx_gap,
385 HRTIMER_MODE_REL_SOFT);
386 break;
387
388 case ISOTP_FC_WT:
389 /* start timer to wait for next FC frame */
390 hrtimer_start(&so->txtimer, ktime_set(1, 0),
391 HRTIMER_MODE_REL_SOFT);
392 break;
393
394 case ISOTP_FC_OVFLW:
395 /* overflow on receiver side - report 'message too long' */
396 sk->sk_err = EMSGSIZE;
397 if (!sock_flag(sk, SOCK_DEAD))
398 sk->sk_error_report(sk);
399 fallthrough;
400
401 default:
402 /* stop this tx job */
403 so->tx.state = ISOTP_IDLE;
404 wake_up_interruptible(&so->wait);
405 }
406 return 0;
407 }
408
isotp_rcv_sf(struct sock * sk,struct canfd_frame * cf,int pcilen,struct sk_buff * skb,int len)409 static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
410 struct sk_buff *skb, int len)
411 {
412 struct isotp_sock *so = isotp_sk(sk);
413 struct sk_buff *nskb;
414
415 hrtimer_cancel(&so->rxtimer);
416 so->rx.state = ISOTP_IDLE;
417
418 if (!len || len > cf->len - pcilen)
419 return 1;
420
421 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
422 check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
423 /* malformed PDU - report 'not a data message' */
424 sk->sk_err = EBADMSG;
425 if (!sock_flag(sk, SOCK_DEAD))
426 sk->sk_error_report(sk);
427 return 1;
428 }
429
430 nskb = alloc_skb(len, gfp_any());
431 if (!nskb)
432 return 1;
433
434 memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
435
436 nskb->tstamp = skb->tstamp;
437 nskb->dev = skb->dev;
438 isotp_rcv_skb(nskb, sk);
439 return 0;
440 }
441
isotp_rcv_ff(struct sock * sk,struct canfd_frame * cf,int ae)442 static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
443 {
444 struct isotp_sock *so = isotp_sk(sk);
445 int i;
446 int off;
447 int ff_pci_sz;
448
449 hrtimer_cancel(&so->rxtimer);
450 so->rx.state = ISOTP_IDLE;
451
452 /* get the used sender LL_DL from the (first) CAN frame data length */
453 so->rx.ll_dl = padlen(cf->len);
454
455 /* the first frame has to use the entire frame up to LL_DL length */
456 if (cf->len != so->rx.ll_dl)
457 return 1;
458
459 /* get the FF_DL */
460 so->rx.len = (cf->data[ae] & 0x0F) << 8;
461 so->rx.len += cf->data[ae + 1];
462
463 /* Check for FF_DL escape sequence supporting 32 bit PDU length */
464 if (so->rx.len) {
465 ff_pci_sz = FF_PCI_SZ12;
466 } else {
467 /* FF_DL = 0 => get real length from next 4 bytes */
468 so->rx.len = cf->data[ae + 2] << 24;
469 so->rx.len += cf->data[ae + 3] << 16;
470 so->rx.len += cf->data[ae + 4] << 8;
471 so->rx.len += cf->data[ae + 5];
472 ff_pci_sz = FF_PCI_SZ32;
473 }
474
475 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
476 off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
477
478 if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
479 return 1;
480
481 if (so->rx.len > MAX_MSG_LENGTH) {
482 /* send FC frame with overflow status */
483 isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
484 return 1;
485 }
486
487 /* copy the first received data bytes */
488 so->rx.idx = 0;
489 for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
490 so->rx.buf[so->rx.idx++] = cf->data[i];
491
492 /* initial setup for this pdu reception */
493 so->rx.sn = 1;
494 so->rx.state = ISOTP_WAIT_DATA;
495
496 /* no creation of flow control frames */
497 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
498 return 0;
499
500 /* send our first FC frame */
501 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
502 return 0;
503 }
504
isotp_rcv_cf(struct sock * sk,struct canfd_frame * cf,int ae,struct sk_buff * skb)505 static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
506 struct sk_buff *skb)
507 {
508 struct isotp_sock *so = isotp_sk(sk);
509 struct sk_buff *nskb;
510 int i;
511
512 if (so->rx.state != ISOTP_WAIT_DATA)
513 return 0;
514
515 /* drop if timestamp gap is less than force_rx_stmin nano secs */
516 if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
517 if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
518 so->force_rx_stmin)
519 return 0;
520
521 so->lastrxcf_tstamp = skb->tstamp;
522 }
523
524 hrtimer_cancel(&so->rxtimer);
525
526 /* CFs are never longer than the FF */
527 if (cf->len > so->rx.ll_dl)
528 return 1;
529
530 /* CFs have usually the LL_DL length */
531 if (cf->len < so->rx.ll_dl) {
532 /* this is only allowed for the last CF */
533 if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
534 return 1;
535 }
536
537 if ((cf->data[ae] & 0x0F) != so->rx.sn) {
538 /* wrong sn detected - report 'illegal byte sequence' */
539 sk->sk_err = EILSEQ;
540 if (!sock_flag(sk, SOCK_DEAD))
541 sk->sk_error_report(sk);
542
543 /* reset rx state */
544 so->rx.state = ISOTP_IDLE;
545 return 1;
546 }
547 so->rx.sn++;
548 so->rx.sn %= 16;
549
550 for (i = ae + N_PCI_SZ; i < cf->len; i++) {
551 so->rx.buf[so->rx.idx++] = cf->data[i];
552 if (so->rx.idx >= so->rx.len)
553 break;
554 }
555
556 if (so->rx.idx >= so->rx.len) {
557 /* we are done */
558 so->rx.state = ISOTP_IDLE;
559
560 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
561 check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
562 /* malformed PDU - report 'not a data message' */
563 sk->sk_err = EBADMSG;
564 if (!sock_flag(sk, SOCK_DEAD))
565 sk->sk_error_report(sk);
566 return 1;
567 }
568
569 nskb = alloc_skb(so->rx.len, gfp_any());
570 if (!nskb)
571 return 1;
572
573 memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
574 so->rx.len);
575
576 nskb->tstamp = skb->tstamp;
577 nskb->dev = skb->dev;
578 isotp_rcv_skb(nskb, sk);
579 return 0;
580 }
581
582 /* perform blocksize handling, if enabled */
583 if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
584 /* start rx timeout watchdog */
585 hrtimer_start(&so->rxtimer, ktime_set(1, 0),
586 HRTIMER_MODE_REL_SOFT);
587 return 0;
588 }
589
590 /* no creation of flow control frames */
591 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
592 return 0;
593
594 /* we reached the specified blocksize so->rxfc.bs */
595 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
596 return 0;
597 }
598
isotp_rcv(struct sk_buff * skb,void * data)599 static void isotp_rcv(struct sk_buff *skb, void *data)
600 {
601 struct sock *sk = (struct sock *)data;
602 struct isotp_sock *so = isotp_sk(sk);
603 struct canfd_frame *cf;
604 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
605 u8 n_pci_type, sf_dl;
606
607 /* Strictly receive only frames with the configured MTU size
608 * => clear separation of CAN2.0 / CAN FD transport channels
609 */
610 if (skb->len != so->ll.mtu)
611 return;
612
613 cf = (struct canfd_frame *)skb->data;
614
615 /* if enabled: check reception of my configured extended address */
616 if (ae && cf->data[0] != so->opt.rx_ext_address)
617 return;
618
619 n_pci_type = cf->data[ae] & 0xF0;
620
621 /* Make sure the state changes and data structures stay consistent at
622 * CAN frame reception time. This locking is not needed in real world
623 * use cases but the inconsistency can be triggered with syzkaller.
624 */
625 spin_lock(&so->rx_lock);
626
627 if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
628 /* check rx/tx path half duplex expectations */
629 if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
630 (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
631 goto out_unlock;
632 }
633
634 switch (n_pci_type) {
635 case N_PCI_FC:
636 /* tx path: flow control frame containing the FC parameters */
637 isotp_rcv_fc(so, cf, ae);
638 break;
639
640 case N_PCI_SF:
641 /* rx path: single frame
642 *
643 * As we do not have a rx.ll_dl configuration, we can only test
644 * if the CAN frames payload length matches the LL_DL == 8
645 * requirements - no matter if it's CAN 2.0 or CAN FD
646 */
647
648 /* get the SF_DL from the N_PCI byte */
649 sf_dl = cf->data[ae] & 0x0F;
650
651 if (cf->len <= CAN_MAX_DLEN) {
652 isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
653 } else {
654 if (skb->len == CANFD_MTU) {
655 /* We have a CAN FD frame and CAN_DL is greater than 8:
656 * Only frames with the SF_DL == 0 ESC value are valid.
657 *
658 * If so take care of the increased SF PCI size
659 * (SF_PCI_SZ8) to point to the message content behind
660 * the extended SF PCI info and get the real SF_DL
661 * length value from the formerly first data byte.
662 */
663 if (sf_dl == 0)
664 isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
665 cf->data[SF_PCI_SZ4 + ae]);
666 }
667 }
668 break;
669
670 case N_PCI_FF:
671 /* rx path: first frame */
672 isotp_rcv_ff(sk, cf, ae);
673 break;
674
675 case N_PCI_CF:
676 /* rx path: consecutive frame */
677 isotp_rcv_cf(sk, cf, ae, skb);
678 break;
679 }
680
681 out_unlock:
682 spin_unlock(&so->rx_lock);
683 }
684
isotp_fill_dataframe(struct canfd_frame * cf,struct isotp_sock * so,int ae,int off)685 static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
686 int ae, int off)
687 {
688 int pcilen = N_PCI_SZ + ae + off;
689 int space = so->tx.ll_dl - pcilen;
690 int num = min_t(int, so->tx.len - so->tx.idx, space);
691 int i;
692
693 cf->can_id = so->txid;
694 cf->len = num + pcilen;
695
696 if (num < space) {
697 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
698 /* user requested padding */
699 cf->len = padlen(cf->len);
700 memset(cf->data, so->opt.txpad_content, cf->len);
701 } else if (cf->len > CAN_MAX_DLEN) {
702 /* mandatory padding for CAN FD frames */
703 cf->len = padlen(cf->len);
704 memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
705 cf->len);
706 }
707 }
708
709 for (i = 0; i < num; i++)
710 cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
711
712 if (ae)
713 cf->data[0] = so->opt.ext_address;
714 }
715
isotp_create_fframe(struct canfd_frame * cf,struct isotp_sock * so,int ae)716 static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
717 int ae)
718 {
719 int i;
720 int ff_pci_sz;
721
722 cf->can_id = so->txid;
723 cf->len = so->tx.ll_dl;
724 if (ae)
725 cf->data[0] = so->opt.ext_address;
726
727 /* create N_PCI bytes with 12/32 bit FF_DL data length */
728 if (so->tx.len > 4095) {
729 /* use 32 bit FF_DL notation */
730 cf->data[ae] = N_PCI_FF;
731 cf->data[ae + 1] = 0;
732 cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
733 cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
734 cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
735 cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
736 ff_pci_sz = FF_PCI_SZ32;
737 } else {
738 /* use 12 bit FF_DL notation */
739 cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
740 cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
741 ff_pci_sz = FF_PCI_SZ12;
742 }
743
744 /* add first data bytes depending on ae */
745 for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
746 cf->data[i] = so->tx.buf[so->tx.idx++];
747
748 so->tx.sn = 1;
749 so->tx.state = ISOTP_WAIT_FIRST_FC;
750 }
751
isotp_tx_timer_handler(struct hrtimer * hrtimer)752 static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
753 {
754 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
755 txtimer);
756 struct sock *sk = &so->sk;
757 struct sk_buff *skb;
758 struct net_device *dev;
759 struct canfd_frame *cf;
760 enum hrtimer_restart restart = HRTIMER_NORESTART;
761 int can_send_ret;
762 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
763
764 switch (so->tx.state) {
765 case ISOTP_WAIT_FC:
766 case ISOTP_WAIT_FIRST_FC:
767
768 /* we did not get any flow control frame in time */
769
770 /* report 'communication error on send' */
771 sk->sk_err = ECOMM;
772 if (!sock_flag(sk, SOCK_DEAD))
773 sk->sk_error_report(sk);
774
775 /* reset tx state */
776 so->tx.state = ISOTP_IDLE;
777 wake_up_interruptible(&so->wait);
778 break;
779
780 case ISOTP_SENDING:
781
782 /* push out the next segmented pdu */
783 dev = dev_get_by_index(sock_net(sk), so->ifindex);
784 if (!dev)
785 break;
786
787 isotp_tx_burst:
788 skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
789 GFP_ATOMIC);
790 if (!skb) {
791 dev_put(dev);
792 break;
793 }
794
795 can_skb_reserve(skb);
796 can_skb_prv(skb)->ifindex = dev->ifindex;
797 can_skb_prv(skb)->skbcnt = 0;
798
799 cf = (struct canfd_frame *)skb->data;
800 skb_put_zero(skb, so->ll.mtu);
801
802 /* create consecutive frame */
803 isotp_fill_dataframe(cf, so, ae, 0);
804
805 /* place consecutive frame N_PCI in appropriate index */
806 cf->data[ae] = N_PCI_CF | so->tx.sn++;
807 so->tx.sn %= 16;
808 so->tx.bs++;
809
810 cf->flags = so->ll.tx_flags;
811
812 skb->dev = dev;
813 can_skb_set_owner(skb, sk);
814
815 can_send_ret = can_send(skb, 1);
816 if (can_send_ret)
817 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
818 __func__, can_send_ret);
819
820 if (so->tx.idx >= so->tx.len) {
821 /* we are done */
822 so->tx.state = ISOTP_IDLE;
823 dev_put(dev);
824 wake_up_interruptible(&so->wait);
825 break;
826 }
827
828 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
829 /* stop and wait for FC */
830 so->tx.state = ISOTP_WAIT_FC;
831 dev_put(dev);
832 hrtimer_set_expires(&so->txtimer,
833 ktime_add(ktime_get(),
834 ktime_set(1, 0)));
835 restart = HRTIMER_RESTART;
836 break;
837 }
838
839 /* no gap between data frames needed => use burst mode */
840 if (!so->tx_gap)
841 goto isotp_tx_burst;
842
843 /* start timer to send next data frame with correct delay */
844 dev_put(dev);
845 hrtimer_set_expires(&so->txtimer,
846 ktime_add(ktime_get(), so->tx_gap));
847 restart = HRTIMER_RESTART;
848 break;
849
850 default:
851 WARN_ON_ONCE(1);
852 }
853
854 return restart;
855 }
856
isotp_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)857 static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
858 {
859 struct sock *sk = sock->sk;
860 struct isotp_sock *so = isotp_sk(sk);
861 u32 old_state = so->tx.state;
862 struct sk_buff *skb;
863 struct net_device *dev;
864 struct canfd_frame *cf;
865 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
866 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
867 s64 hrtimer_sec = 0;
868 int off;
869 int err;
870
871 if (!so->bound)
872 return -EADDRNOTAVAIL;
873
874 /* we do not support multiple buffers - for now */
875 if (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE ||
876 wq_has_sleeper(&so->wait)) {
877 if (msg->msg_flags & MSG_DONTWAIT) {
878 err = -EAGAIN;
879 goto err_out;
880 }
881
882 /* wait for complete transmission of current pdu */
883 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
884 if (err)
885 goto err_out;
886 }
887
888 if (!size || size > MAX_MSG_LENGTH) {
889 err = -EINVAL;
890 goto err_out_drop;
891 }
892
893 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
894 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
895
896 /* does the given data fit into a single frame for SF_BROADCAST? */
897 if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) &&
898 (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
899 err = -EINVAL;
900 goto err_out_drop;
901 }
902
903 err = memcpy_from_msg(so->tx.buf, msg, size);
904 if (err < 0)
905 goto err_out_drop;
906
907 dev = dev_get_by_index(sock_net(sk), so->ifindex);
908 if (!dev) {
909 err = -ENXIO;
910 goto err_out_drop;
911 }
912
913 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
914 msg->msg_flags & MSG_DONTWAIT, &err);
915 if (!skb) {
916 dev_put(dev);
917 goto err_out_drop;
918 }
919
920 can_skb_reserve(skb);
921 can_skb_prv(skb)->ifindex = dev->ifindex;
922 can_skb_prv(skb)->skbcnt = 0;
923
924 so->tx.len = size;
925 so->tx.idx = 0;
926
927 cf = (struct canfd_frame *)skb->data;
928 skb_put_zero(skb, so->ll.mtu);
929
930 /* check for single frame transmission depending on TX_DL */
931 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
932 /* The message size generally fits into a SingleFrame - good.
933 *
934 * SF_DL ESC offset optimization:
935 *
936 * When TX_DL is greater 8 but the message would still fit
937 * into a 8 byte CAN frame, we can omit the offset.
938 * This prevents a protocol caused length extension from
939 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
940 */
941 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
942 off = 0;
943
944 isotp_fill_dataframe(cf, so, ae, off);
945
946 /* place single frame N_PCI w/o length in appropriate index */
947 cf->data[ae] = N_PCI_SF;
948
949 /* place SF_DL size value depending on the SF_DL ESC offset */
950 if (off)
951 cf->data[SF_PCI_SZ4 + ae] = size;
952 else
953 cf->data[ae] |= size;
954
955 so->tx.state = ISOTP_IDLE;
956 wake_up_interruptible(&so->wait);
957
958 /* don't enable wait queue for a single frame transmission */
959 wait_tx_done = 0;
960 } else {
961 /* send first frame and wait for FC */
962
963 isotp_create_fframe(cf, so, ae);
964
965 /* start timeout for FC */
966 hrtimer_sec = 1;
967 hrtimer_start(&so->txtimer, ktime_set(hrtimer_sec, 0),
968 HRTIMER_MODE_REL_SOFT);
969 }
970
971 /* send the first or only CAN frame */
972 cf->flags = so->ll.tx_flags;
973
974 skb->dev = dev;
975 skb->sk = sk;
976 err = can_send(skb, 1);
977 dev_put(dev);
978 if (err) {
979 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
980 __func__, err);
981
982 /* no transmission -> no timeout monitoring */
983 if (hrtimer_sec)
984 hrtimer_cancel(&so->txtimer);
985
986 goto err_out_drop;
987 }
988
989 if (wait_tx_done) {
990 /* wait for complete transmission of current pdu */
991 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
992
993 err = sock_error(sk);
994 if (err)
995 return err;
996 }
997
998 return size;
999
1000 err_out_drop:
1001 /* drop this PDU and unlock a potential wait queue */
1002 old_state = ISOTP_IDLE;
1003 err_out:
1004 so->tx.state = old_state;
1005 if (so->tx.state == ISOTP_IDLE)
1006 wake_up_interruptible(&so->wait);
1007
1008 return err;
1009 }
1010
isotp_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)1011 static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1012 int flags)
1013 {
1014 struct sock *sk = sock->sk;
1015 struct sk_buff *skb;
1016 struct isotp_sock *so = isotp_sk(sk);
1017 int noblock = flags & MSG_DONTWAIT;
1018 int ret = 0;
1019
1020 if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK | MSG_CMSG_COMPAT))
1021 return -EINVAL;
1022
1023 if (!so->bound)
1024 return -EADDRNOTAVAIL;
1025
1026 flags &= ~MSG_DONTWAIT;
1027 skb = skb_recv_datagram(sk, flags, noblock, &ret);
1028 if (!skb)
1029 return ret;
1030
1031 if (size < skb->len)
1032 msg->msg_flags |= MSG_TRUNC;
1033 else
1034 size = skb->len;
1035
1036 ret = memcpy_to_msg(msg, skb->data, size);
1037 if (ret < 0)
1038 goto out_err;
1039
1040 sock_recv_timestamp(msg, sk, skb);
1041
1042 if (msg->msg_name) {
1043 __sockaddr_check_size(ISOTP_MIN_NAMELEN);
1044 msg->msg_namelen = ISOTP_MIN_NAMELEN;
1045 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1046 }
1047
1048 /* set length of return value */
1049 ret = (flags & MSG_TRUNC) ? skb->len : size;
1050
1051 out_err:
1052 skb_free_datagram(sk, skb);
1053
1054 return ret;
1055 }
1056
isotp_release(struct socket * sock)1057 static int isotp_release(struct socket *sock)
1058 {
1059 struct sock *sk = sock->sk;
1060 struct isotp_sock *so;
1061 struct net *net;
1062
1063 if (!sk)
1064 return 0;
1065
1066 so = isotp_sk(sk);
1067 net = sock_net(sk);
1068
1069 /* wait for complete transmission of current pdu */
1070 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1071
1072 spin_lock(&isotp_notifier_lock);
1073 while (isotp_busy_notifier == so) {
1074 spin_unlock(&isotp_notifier_lock);
1075 schedule_timeout_uninterruptible(1);
1076 spin_lock(&isotp_notifier_lock);
1077 }
1078 list_del(&so->notifier);
1079 spin_unlock(&isotp_notifier_lock);
1080
1081 lock_sock(sk);
1082
1083 /* remove current filters & unregister */
1084 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) {
1085 if (so->ifindex) {
1086 struct net_device *dev;
1087
1088 dev = dev_get_by_index(net, so->ifindex);
1089 if (dev) {
1090 can_rx_unregister(net, dev, so->rxid,
1091 SINGLE_MASK(so->rxid),
1092 isotp_rcv, sk);
1093 dev_put(dev);
1094 synchronize_rcu();
1095 }
1096 }
1097 }
1098
1099 hrtimer_cancel(&so->txtimer);
1100 hrtimer_cancel(&so->rxtimer);
1101
1102 so->ifindex = 0;
1103 so->bound = 0;
1104
1105 sock_orphan(sk);
1106 sock->sk = NULL;
1107
1108 release_sock(sk);
1109 sock_put(sk);
1110
1111 return 0;
1112 }
1113
isotp_bind(struct socket * sock,struct sockaddr * uaddr,int len)1114 static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1115 {
1116 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1117 struct sock *sk = sock->sk;
1118 struct isotp_sock *so = isotp_sk(sk);
1119 struct net *net = sock_net(sk);
1120 int ifindex;
1121 struct net_device *dev;
1122 canid_t tx_id, rx_id;
1123 int err = 0;
1124 int notify_enetdown = 0;
1125 int do_rx_reg = 1;
1126
1127 if (len < ISOTP_MIN_NAMELEN)
1128 return -EINVAL;
1129
1130 /* sanitize tx/rx CAN identifiers */
1131 tx_id = addr->can_addr.tp.tx_id;
1132 if (tx_id & CAN_EFF_FLAG)
1133 tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1134 else
1135 tx_id &= CAN_SFF_MASK;
1136
1137 rx_id = addr->can_addr.tp.rx_id;
1138 if (rx_id & CAN_EFF_FLAG)
1139 rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1140 else
1141 rx_id &= CAN_SFF_MASK;
1142
1143 if (!addr->can_ifindex)
1144 return -ENODEV;
1145
1146 lock_sock(sk);
1147
1148 if (so->bound) {
1149 err = -EINVAL;
1150 goto out;
1151 }
1152
1153 /* do not register frame reception for functional addressing */
1154 if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
1155 do_rx_reg = 0;
1156
1157 /* do not validate rx address for functional addressing */
1158 if (do_rx_reg && rx_id == tx_id) {
1159 err = -EADDRNOTAVAIL;
1160 goto out;
1161 }
1162
1163 dev = dev_get_by_index(net, addr->can_ifindex);
1164 if (!dev) {
1165 err = -ENODEV;
1166 goto out;
1167 }
1168 if (dev->type != ARPHRD_CAN) {
1169 dev_put(dev);
1170 err = -ENODEV;
1171 goto out;
1172 }
1173 if (dev->mtu < so->ll.mtu) {
1174 dev_put(dev);
1175 err = -EINVAL;
1176 goto out;
1177 }
1178 if (!(dev->flags & IFF_UP))
1179 notify_enetdown = 1;
1180
1181 ifindex = dev->ifindex;
1182
1183 if (do_rx_reg)
1184 can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
1185 isotp_rcv, sk, "isotp", sk);
1186
1187 dev_put(dev);
1188
1189 /* switch to new settings */
1190 so->ifindex = ifindex;
1191 so->rxid = rx_id;
1192 so->txid = tx_id;
1193 so->bound = 1;
1194
1195 out:
1196 release_sock(sk);
1197
1198 if (notify_enetdown) {
1199 sk->sk_err = ENETDOWN;
1200 if (!sock_flag(sk, SOCK_DEAD))
1201 sk->sk_error_report(sk);
1202 }
1203
1204 return err;
1205 }
1206
isotp_getname(struct socket * sock,struct sockaddr * uaddr,int peer)1207 static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
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
1213 if (peer)
1214 return -EOPNOTSUPP;
1215
1216 memset(addr, 0, ISOTP_MIN_NAMELEN);
1217 addr->can_family = AF_CAN;
1218 addr->can_ifindex = so->ifindex;
1219 addr->can_addr.tp.rx_id = so->rxid;
1220 addr->can_addr.tp.tx_id = so->txid;
1221
1222 return ISOTP_MIN_NAMELEN;
1223 }
1224
isotp_setsockopt_locked(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1225 static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
1226 sockptr_t optval, unsigned int optlen)
1227 {
1228 struct sock *sk = sock->sk;
1229 struct isotp_sock *so = isotp_sk(sk);
1230 int ret = 0;
1231
1232 if (so->bound)
1233 return -EISCONN;
1234
1235 switch (optname) {
1236 case CAN_ISOTP_OPTS:
1237 if (optlen != sizeof(struct can_isotp_options))
1238 return -EINVAL;
1239
1240 if (copy_from_sockptr(&so->opt, optval, optlen))
1241 return -EFAULT;
1242
1243 /* no separate rx_ext_address is given => use ext_address */
1244 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1245 so->opt.rx_ext_address = so->opt.ext_address;
1246
1247 /* check for frame_txtime changes (0 => no changes) */
1248 if (so->opt.frame_txtime) {
1249 if (so->opt.frame_txtime == CAN_ISOTP_FRAME_TXTIME_ZERO)
1250 so->frame_txtime = 0;
1251 else
1252 so->frame_txtime = so->opt.frame_txtime;
1253 }
1254 break;
1255
1256 case CAN_ISOTP_RECV_FC:
1257 if (optlen != sizeof(struct can_isotp_fc_options))
1258 return -EINVAL;
1259
1260 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1261 return -EFAULT;
1262 break;
1263
1264 case CAN_ISOTP_TX_STMIN:
1265 if (optlen != sizeof(u32))
1266 return -EINVAL;
1267
1268 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1269 return -EFAULT;
1270 break;
1271
1272 case CAN_ISOTP_RX_STMIN:
1273 if (optlen != sizeof(u32))
1274 return -EINVAL;
1275
1276 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1277 return -EFAULT;
1278 break;
1279
1280 case CAN_ISOTP_LL_OPTS:
1281 if (optlen == sizeof(struct can_isotp_ll_options)) {
1282 struct can_isotp_ll_options ll;
1283
1284 if (copy_from_sockptr(&ll, optval, optlen))
1285 return -EFAULT;
1286
1287 /* check for correct ISO 11898-1 DLC data length */
1288 if (ll.tx_dl != padlen(ll.tx_dl))
1289 return -EINVAL;
1290
1291 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1292 return -EINVAL;
1293
1294 if (ll.mtu == CAN_MTU &&
1295 (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1296 return -EINVAL;
1297
1298 memcpy(&so->ll, &ll, sizeof(ll));
1299
1300 /* set ll_dl for tx path to similar place as for rx */
1301 so->tx.ll_dl = ll.tx_dl;
1302 } else {
1303 return -EINVAL;
1304 }
1305 break;
1306
1307 default:
1308 ret = -ENOPROTOOPT;
1309 }
1310
1311 return ret;
1312 }
1313
isotp_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1314 static int isotp_setsockopt(struct socket *sock, int level, int optname,
1315 sockptr_t optval, unsigned int optlen)
1316
1317 {
1318 struct sock *sk = sock->sk;
1319 int ret;
1320
1321 if (level != SOL_CAN_ISOTP)
1322 return -EINVAL;
1323
1324 lock_sock(sk);
1325 ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
1326 release_sock(sk);
1327 return ret;
1328 }
1329
isotp_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)1330 static int isotp_getsockopt(struct socket *sock, int level, int optname,
1331 char __user *optval, int __user *optlen)
1332 {
1333 struct sock *sk = sock->sk;
1334 struct isotp_sock *so = isotp_sk(sk);
1335 int len;
1336 void *val;
1337
1338 if (level != SOL_CAN_ISOTP)
1339 return -EINVAL;
1340 if (get_user(len, optlen))
1341 return -EFAULT;
1342 if (len < 0)
1343 return -EINVAL;
1344
1345 switch (optname) {
1346 case CAN_ISOTP_OPTS:
1347 len = min_t(int, len, sizeof(struct can_isotp_options));
1348 val = &so->opt;
1349 break;
1350
1351 case CAN_ISOTP_RECV_FC:
1352 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1353 val = &so->rxfc;
1354 break;
1355
1356 case CAN_ISOTP_TX_STMIN:
1357 len = min_t(int, len, sizeof(u32));
1358 val = &so->force_tx_stmin;
1359 break;
1360
1361 case CAN_ISOTP_RX_STMIN:
1362 len = min_t(int, len, sizeof(u32));
1363 val = &so->force_rx_stmin;
1364 break;
1365
1366 case CAN_ISOTP_LL_OPTS:
1367 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1368 val = &so->ll;
1369 break;
1370
1371 default:
1372 return -ENOPROTOOPT;
1373 }
1374
1375 if (put_user(len, optlen))
1376 return -EFAULT;
1377 if (copy_to_user(optval, val, len))
1378 return -EFAULT;
1379 return 0;
1380 }
1381
isotp_notify(struct isotp_sock * so,unsigned long msg,struct net_device * dev)1382 static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1383 struct net_device *dev)
1384 {
1385 struct sock *sk = &so->sk;
1386
1387 if (!net_eq(dev_net(dev), sock_net(sk)))
1388 return;
1389
1390 if (so->ifindex != dev->ifindex)
1391 return;
1392
1393 switch (msg) {
1394 case NETDEV_UNREGISTER:
1395 lock_sock(sk);
1396 /* remove current filters & unregister */
1397 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))
1398 can_rx_unregister(dev_net(dev), dev, so->rxid,
1399 SINGLE_MASK(so->rxid),
1400 isotp_rcv, sk);
1401
1402 so->ifindex = 0;
1403 so->bound = 0;
1404 release_sock(sk);
1405
1406 sk->sk_err = ENODEV;
1407 if (!sock_flag(sk, SOCK_DEAD))
1408 sk->sk_error_report(sk);
1409 break;
1410
1411 case NETDEV_DOWN:
1412 sk->sk_err = ENETDOWN;
1413 if (!sock_flag(sk, SOCK_DEAD))
1414 sk->sk_error_report(sk);
1415 break;
1416 }
1417 }
1418
isotp_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)1419 static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1420 void *ptr)
1421 {
1422 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1423
1424 if (dev->type != ARPHRD_CAN)
1425 return NOTIFY_DONE;
1426 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1427 return NOTIFY_DONE;
1428 if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1429 return NOTIFY_DONE;
1430
1431 spin_lock(&isotp_notifier_lock);
1432 list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1433 spin_unlock(&isotp_notifier_lock);
1434 isotp_notify(isotp_busy_notifier, msg, dev);
1435 spin_lock(&isotp_notifier_lock);
1436 }
1437 isotp_busy_notifier = NULL;
1438 spin_unlock(&isotp_notifier_lock);
1439 return NOTIFY_DONE;
1440 }
1441
isotp_init(struct sock * sk)1442 static int isotp_init(struct sock *sk)
1443 {
1444 struct isotp_sock *so = isotp_sk(sk);
1445
1446 so->ifindex = 0;
1447 so->bound = 0;
1448
1449 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1450 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1451 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1452 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1453 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1454 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1455 so->frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1456 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1457 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1458 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1459 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1460 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1461 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1462
1463 /* set ll_dl for tx path to similar place as for rx */
1464 so->tx.ll_dl = so->ll.tx_dl;
1465
1466 so->rx.state = ISOTP_IDLE;
1467 so->tx.state = ISOTP_IDLE;
1468
1469 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1470 so->rxtimer.function = isotp_rx_timer_handler;
1471 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1472 so->txtimer.function = isotp_tx_timer_handler;
1473
1474 init_waitqueue_head(&so->wait);
1475 spin_lock_init(&so->rx_lock);
1476
1477 spin_lock(&isotp_notifier_lock);
1478 list_add_tail(&so->notifier, &isotp_notifier_list);
1479 spin_unlock(&isotp_notifier_lock);
1480
1481 return 0;
1482 }
1483
isotp_poll(struct file * file,struct socket * sock,poll_table * wait)1484 static __poll_t isotp_poll(struct file *file, struct socket *sock, poll_table *wait)
1485 {
1486 struct sock *sk = sock->sk;
1487 struct isotp_sock *so = isotp_sk(sk);
1488
1489 __poll_t mask = datagram_poll(file, sock, wait);
1490 poll_wait(file, &so->wait, wait);
1491
1492 /* Check for false positives due to TX state */
1493 if ((mask & EPOLLWRNORM) && (so->tx.state != ISOTP_IDLE))
1494 mask &= ~(EPOLLOUT | EPOLLWRNORM);
1495
1496 return mask;
1497 }
1498
isotp_sock_no_ioctlcmd(struct socket * sock,unsigned int cmd,unsigned long arg)1499 static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1500 unsigned long arg)
1501 {
1502 /* no ioctls for socket layer -> hand it down to NIC layer */
1503 return -ENOIOCTLCMD;
1504 }
1505
1506 static const struct proto_ops isotp_ops = {
1507 .family = PF_CAN,
1508 .release = isotp_release,
1509 .bind = isotp_bind,
1510 .connect = sock_no_connect,
1511 .socketpair = sock_no_socketpair,
1512 .accept = sock_no_accept,
1513 .getname = isotp_getname,
1514 .poll = isotp_poll,
1515 .ioctl = isotp_sock_no_ioctlcmd,
1516 .gettstamp = sock_gettstamp,
1517 .listen = sock_no_listen,
1518 .shutdown = sock_no_shutdown,
1519 .setsockopt = isotp_setsockopt,
1520 .getsockopt = isotp_getsockopt,
1521 .sendmsg = isotp_sendmsg,
1522 .recvmsg = isotp_recvmsg,
1523 .mmap = sock_no_mmap,
1524 .sendpage = sock_no_sendpage,
1525 };
1526
1527 static struct proto isotp_proto __read_mostly = {
1528 .name = "CAN_ISOTP",
1529 .owner = THIS_MODULE,
1530 .obj_size = sizeof(struct isotp_sock),
1531 .init = isotp_init,
1532 };
1533
1534 static const struct can_proto isotp_can_proto = {
1535 .type = SOCK_DGRAM,
1536 .protocol = CAN_ISOTP,
1537 .ops = &isotp_ops,
1538 .prot = &isotp_proto,
1539 };
1540
1541 static struct notifier_block canisotp_notifier = {
1542 .notifier_call = isotp_notifier
1543 };
1544
isotp_module_init(void)1545 static __init int isotp_module_init(void)
1546 {
1547 int err;
1548
1549 pr_info("can: isotp protocol\n");
1550
1551 err = can_proto_register(&isotp_can_proto);
1552 if (err < 0)
1553 pr_err("can: registration of isotp protocol failed\n");
1554 else
1555 register_netdevice_notifier(&canisotp_notifier);
1556
1557 return err;
1558 }
1559
isotp_module_exit(void)1560 static __exit void isotp_module_exit(void)
1561 {
1562 can_proto_unregister(&isotp_can_proto);
1563 unregister_netdevice_notifier(&canisotp_notifier);
1564 }
1565
1566 module_init(isotp_module_init);
1567 module_exit(isotp_module_exit);
1568