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/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
75 MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
76 MODULE_LICENSE("Dual BSD/GPL");
77 MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
78 MODULE_ALIAS("can-proto-6");
79
80 #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
81 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
82 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
83
84 /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
85 * take full 32 bit values (4 Gbyte). We would need some good concept to handle
86 * this between user space and kernel space. For now increase the static buffer
87 * to something about 8 kbyte to be able to test this new functionality.
88 */
89 #define MAX_MSG_LENGTH 8200
90
91 /* N_PCI type values in bits 7-4 of N_PCI bytes */
92 #define N_PCI_SF 0x00 /* single frame */
93 #define N_PCI_FF 0x10 /* first frame */
94 #define N_PCI_CF 0x20 /* consecutive frame */
95 #define N_PCI_FC 0x30 /* flow control */
96
97 #define N_PCI_SZ 1 /* size of the PCI byte #1 */
98 #define SF_PCI_SZ4 1 /* size of SingleFrame PCI including 4 bit SF_DL */
99 #define SF_PCI_SZ8 2 /* size of SingleFrame PCI including 8 bit SF_DL */
100 #define FF_PCI_SZ12 2 /* size of FirstFrame PCI including 12 bit FF_DL */
101 #define FF_PCI_SZ32 6 /* size of FirstFrame PCI including 32 bit FF_DL */
102 #define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
103
104 #define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
105
106 /* Flow Status given in FC frame */
107 #define ISOTP_FC_CTS 0 /* clear to send */
108 #define ISOTP_FC_WT 1 /* wait */
109 #define ISOTP_FC_OVFLW 2 /* overflow */
110
111 enum {
112 ISOTP_IDLE = 0,
113 ISOTP_WAIT_FIRST_FC,
114 ISOTP_WAIT_FC,
115 ISOTP_WAIT_DATA,
116 ISOTP_SENDING
117 };
118
119 struct tpcon {
120 int idx;
121 int len;
122 u8 state;
123 u8 bs;
124 u8 sn;
125 u8 ll_dl;
126 u8 buf[MAX_MSG_LENGTH + 1];
127 };
128
129 struct isotp_sock {
130 struct sock sk;
131 int bound;
132 int ifindex;
133 canid_t txid;
134 canid_t rxid;
135 ktime_t tx_gap;
136 ktime_t lastrxcf_tstamp;
137 struct hrtimer rxtimer, txtimer;
138 struct can_isotp_options opt;
139 struct can_isotp_fc_options rxfc, txfc;
140 struct can_isotp_ll_options ll;
141 u32 force_tx_stmin;
142 u32 force_rx_stmin;
143 struct tpcon rx, tx;
144 struct notifier_block notifier;
145 wait_queue_head_t wait;
146 };
147
isotp_sk(const struct sock * sk)148 static inline struct isotp_sock *isotp_sk(const struct sock *sk)
149 {
150 return (struct isotp_sock *)sk;
151 }
152
isotp_rx_timer_handler(struct hrtimer * hrtimer)153 static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
154 {
155 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
156 rxtimer);
157 struct sock *sk = &so->sk;
158
159 if (so->rx.state == ISOTP_WAIT_DATA) {
160 /* we did not get new data frames in time */
161
162 /* report 'connection timed out' */
163 sk->sk_err = ETIMEDOUT;
164 if (!sock_flag(sk, SOCK_DEAD))
165 sk->sk_error_report(sk);
166
167 /* reset rx state */
168 so->rx.state = ISOTP_IDLE;
169 }
170
171 return HRTIMER_NORESTART;
172 }
173
isotp_send_fc(struct sock * sk,int ae,u8 flowstatus)174 static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
175 {
176 struct net_device *dev;
177 struct sk_buff *nskb;
178 struct canfd_frame *ncf;
179 struct isotp_sock *so = isotp_sk(sk);
180 int can_send_ret;
181
182 nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
183 if (!nskb)
184 return 1;
185
186 dev = dev_get_by_index(sock_net(sk), so->ifindex);
187 if (!dev) {
188 kfree_skb(nskb);
189 return 1;
190 }
191
192 can_skb_reserve(nskb);
193 can_skb_prv(nskb)->ifindex = dev->ifindex;
194 can_skb_prv(nskb)->skbcnt = 0;
195
196 nskb->dev = dev;
197 can_skb_set_owner(nskb, sk);
198 ncf = (struct canfd_frame *)nskb->data;
199 skb_put(nskb, so->ll.mtu);
200
201 /* create & send flow control reply */
202 ncf->can_id = so->txid;
203
204 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
205 memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
206 ncf->len = CAN_MAX_DLEN;
207 } else {
208 ncf->len = ae + FC_CONTENT_SZ;
209 }
210
211 ncf->data[ae] = N_PCI_FC | flowstatus;
212 ncf->data[ae + 1] = so->rxfc.bs;
213 ncf->data[ae + 2] = so->rxfc.stmin;
214
215 if (ae)
216 ncf->data[0] = so->opt.ext_address;
217
218 if (so->ll.mtu == CANFD_MTU)
219 ncf->flags = so->ll.tx_flags;
220
221 can_send_ret = can_send(nskb, 1);
222 if (can_send_ret)
223 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
224 __func__, can_send_ret);
225
226 dev_put(dev);
227
228 /* reset blocksize counter */
229 so->rx.bs = 0;
230
231 /* reset last CF frame rx timestamp for rx stmin enforcement */
232 so->lastrxcf_tstamp = ktime_set(0, 0);
233
234 /* start rx timeout watchdog */
235 hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
236 return 0;
237 }
238
isotp_rcv_skb(struct sk_buff * skb,struct sock * sk)239 static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
240 {
241 struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
242
243 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
244
245 memset(addr, 0, sizeof(*addr));
246 addr->can_family = AF_CAN;
247 addr->can_ifindex = skb->dev->ifindex;
248
249 if (sock_queue_rcv_skb(sk, skb) < 0)
250 kfree_skb(skb);
251 }
252
padlen(u8 datalen)253 static u8 padlen(u8 datalen)
254 {
255 static const u8 plen[] = {
256 8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
257 12, 12, 12, 12, /* 9 - 12 */
258 16, 16, 16, 16, /* 13 - 16 */
259 20, 20, 20, 20, /* 17 - 20 */
260 24, 24, 24, 24, /* 21 - 24 */
261 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
262 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
263 48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
264 };
265
266 if (datalen > 48)
267 return 64;
268
269 return plen[datalen];
270 }
271
272 /* check for length optimization and return 1/true when the check fails */
check_optimized(struct canfd_frame * cf,int start_index)273 static int check_optimized(struct canfd_frame *cf, int start_index)
274 {
275 /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
276 * padding would start at this point. E.g. if the padding would
277 * start at cf.data[7] cf->len has to be 7 to be optimal.
278 * Note: The data[] index starts with zero.
279 */
280 if (cf->len <= CAN_MAX_DLEN)
281 return (cf->len != start_index);
282
283 /* This relation is also valid in the non-linear DLC range, where
284 * we need to take care of the minimal next possible CAN_DL.
285 * The correct check would be (padlen(cf->len) != padlen(start_index)).
286 * But as cf->len can only take discrete values from 12, .., 64 at this
287 * point the padlen(cf->len) is always equal to cf->len.
288 */
289 return (cf->len != padlen(start_index));
290 }
291
292 /* 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)293 static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
294 int start_index, u8 content)
295 {
296 int i;
297
298 /* no RX_PADDING value => check length of optimized frame length */
299 if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
300 if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
301 return check_optimized(cf, start_index);
302
303 /* no valid test against empty value => ignore frame */
304 return 1;
305 }
306
307 /* check datalength of correctly padded CAN frame */
308 if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
309 cf->len != padlen(cf->len))
310 return 1;
311
312 /* check padding content */
313 if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
314 for (i = start_index; i < cf->len; i++)
315 if (cf->data[i] != content)
316 return 1;
317 }
318 return 0;
319 }
320
isotp_rcv_fc(struct isotp_sock * so,struct canfd_frame * cf,int ae)321 static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
322 {
323 struct sock *sk = &so->sk;
324
325 if (so->tx.state != ISOTP_WAIT_FC &&
326 so->tx.state != ISOTP_WAIT_FIRST_FC)
327 return 0;
328
329 hrtimer_cancel(&so->txtimer);
330
331 if ((cf->len < ae + FC_CONTENT_SZ) ||
332 ((so->opt.flags & ISOTP_CHECK_PADDING) &&
333 check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
334 /* malformed PDU - report 'not a data message' */
335 sk->sk_err = EBADMSG;
336 if (!sock_flag(sk, SOCK_DEAD))
337 sk->sk_error_report(sk);
338
339 so->tx.state = ISOTP_IDLE;
340 wake_up_interruptible(&so->wait);
341 return 1;
342 }
343
344 /* get communication parameters only from the first FC frame */
345 if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
346 so->txfc.bs = cf->data[ae + 1];
347 so->txfc.stmin = cf->data[ae + 2];
348
349 /* fix wrong STmin values according spec */
350 if (so->txfc.stmin > 0x7F &&
351 (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
352 so->txfc.stmin = 0x7F;
353
354 so->tx_gap = ktime_set(0, 0);
355 /* add transmission time for CAN frame N_As */
356 so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
357 /* add waiting time for consecutive frames N_Cs */
358 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
359 so->tx_gap = ktime_add_ns(so->tx_gap,
360 so->force_tx_stmin);
361 else if (so->txfc.stmin < 0x80)
362 so->tx_gap = ktime_add_ns(so->tx_gap,
363 so->txfc.stmin * 1000000);
364 else
365 so->tx_gap = ktime_add_ns(so->tx_gap,
366 (so->txfc.stmin - 0xF0)
367 * 100000);
368 so->tx.state = ISOTP_WAIT_FC;
369 }
370
371 switch (cf->data[ae] & 0x0F) {
372 case ISOTP_FC_CTS:
373 so->tx.bs = 0;
374 so->tx.state = ISOTP_SENDING;
375 /* start cyclic timer for sending CF frame */
376 hrtimer_start(&so->txtimer, so->tx_gap,
377 HRTIMER_MODE_REL_SOFT);
378 break;
379
380 case ISOTP_FC_WT:
381 /* start timer to wait for next FC frame */
382 hrtimer_start(&so->txtimer, ktime_set(1, 0),
383 HRTIMER_MODE_REL_SOFT);
384 break;
385
386 case ISOTP_FC_OVFLW:
387 /* overflow on receiver side - report 'message too long' */
388 sk->sk_err = EMSGSIZE;
389 if (!sock_flag(sk, SOCK_DEAD))
390 sk->sk_error_report(sk);
391 fallthrough;
392
393 default:
394 /* stop this tx job */
395 so->tx.state = ISOTP_IDLE;
396 wake_up_interruptible(&so->wait);
397 }
398 return 0;
399 }
400
isotp_rcv_sf(struct sock * sk,struct canfd_frame * cf,int pcilen,struct sk_buff * skb,int len)401 static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
402 struct sk_buff *skb, int len)
403 {
404 struct isotp_sock *so = isotp_sk(sk);
405 struct sk_buff *nskb;
406
407 hrtimer_cancel(&so->rxtimer);
408 so->rx.state = ISOTP_IDLE;
409
410 if (!len || len > cf->len - pcilen)
411 return 1;
412
413 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
414 check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
415 /* malformed PDU - report 'not a data message' */
416 sk->sk_err = EBADMSG;
417 if (!sock_flag(sk, SOCK_DEAD))
418 sk->sk_error_report(sk);
419 return 1;
420 }
421
422 nskb = alloc_skb(len, gfp_any());
423 if (!nskb)
424 return 1;
425
426 memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
427
428 nskb->tstamp = skb->tstamp;
429 nskb->dev = skb->dev;
430 isotp_rcv_skb(nskb, sk);
431 return 0;
432 }
433
isotp_rcv_ff(struct sock * sk,struct canfd_frame * cf,int ae)434 static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
435 {
436 struct isotp_sock *so = isotp_sk(sk);
437 int i;
438 int off;
439 int ff_pci_sz;
440
441 hrtimer_cancel(&so->rxtimer);
442 so->rx.state = ISOTP_IDLE;
443
444 /* get the used sender LL_DL from the (first) CAN frame data length */
445 so->rx.ll_dl = padlen(cf->len);
446
447 /* the first frame has to use the entire frame up to LL_DL length */
448 if (cf->len != so->rx.ll_dl)
449 return 1;
450
451 /* get the FF_DL */
452 so->rx.len = (cf->data[ae] & 0x0F) << 8;
453 so->rx.len += cf->data[ae + 1];
454
455 /* Check for FF_DL escape sequence supporting 32 bit PDU length */
456 if (so->rx.len) {
457 ff_pci_sz = FF_PCI_SZ12;
458 } else {
459 /* FF_DL = 0 => get real length from next 4 bytes */
460 so->rx.len = cf->data[ae + 2] << 24;
461 so->rx.len += cf->data[ae + 3] << 16;
462 so->rx.len += cf->data[ae + 4] << 8;
463 so->rx.len += cf->data[ae + 5];
464 ff_pci_sz = FF_PCI_SZ32;
465 }
466
467 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
468 off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
469
470 if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
471 return 1;
472
473 if (so->rx.len > MAX_MSG_LENGTH) {
474 /* send FC frame with overflow status */
475 isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
476 return 1;
477 }
478
479 /* copy the first received data bytes */
480 so->rx.idx = 0;
481 for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
482 so->rx.buf[so->rx.idx++] = cf->data[i];
483
484 /* initial setup for this pdu reception */
485 so->rx.sn = 1;
486 so->rx.state = ISOTP_WAIT_DATA;
487
488 /* no creation of flow control frames */
489 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
490 return 0;
491
492 /* send our first FC frame */
493 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
494 return 0;
495 }
496
isotp_rcv_cf(struct sock * sk,struct canfd_frame * cf,int ae,struct sk_buff * skb)497 static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
498 struct sk_buff *skb)
499 {
500 struct isotp_sock *so = isotp_sk(sk);
501 struct sk_buff *nskb;
502 int i;
503
504 if (so->rx.state != ISOTP_WAIT_DATA)
505 return 0;
506
507 /* drop if timestamp gap is less than force_rx_stmin nano secs */
508 if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
509 if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
510 so->force_rx_stmin)
511 return 0;
512
513 so->lastrxcf_tstamp = skb->tstamp;
514 }
515
516 hrtimer_cancel(&so->rxtimer);
517
518 /* CFs are never longer than the FF */
519 if (cf->len > so->rx.ll_dl)
520 return 1;
521
522 /* CFs have usually the LL_DL length */
523 if (cf->len < so->rx.ll_dl) {
524 /* this is only allowed for the last CF */
525 if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
526 return 1;
527 }
528
529 if ((cf->data[ae] & 0x0F) != so->rx.sn) {
530 /* wrong sn detected - report 'illegal byte sequence' */
531 sk->sk_err = EILSEQ;
532 if (!sock_flag(sk, SOCK_DEAD))
533 sk->sk_error_report(sk);
534
535 /* reset rx state */
536 so->rx.state = ISOTP_IDLE;
537 return 1;
538 }
539 so->rx.sn++;
540 so->rx.sn %= 16;
541
542 for (i = ae + N_PCI_SZ; i < cf->len; i++) {
543 so->rx.buf[so->rx.idx++] = cf->data[i];
544 if (so->rx.idx >= so->rx.len)
545 break;
546 }
547
548 if (so->rx.idx >= so->rx.len) {
549 /* we are done */
550 so->rx.state = ISOTP_IDLE;
551
552 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
553 check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
554 /* malformed PDU - report 'not a data message' */
555 sk->sk_err = EBADMSG;
556 if (!sock_flag(sk, SOCK_DEAD))
557 sk->sk_error_report(sk);
558 return 1;
559 }
560
561 nskb = alloc_skb(so->rx.len, gfp_any());
562 if (!nskb)
563 return 1;
564
565 memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
566 so->rx.len);
567
568 nskb->tstamp = skb->tstamp;
569 nskb->dev = skb->dev;
570 isotp_rcv_skb(nskb, sk);
571 return 0;
572 }
573
574 /* perform blocksize handling, if enabled */
575 if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
576 /* start rx timeout watchdog */
577 hrtimer_start(&so->rxtimer, ktime_set(1, 0),
578 HRTIMER_MODE_REL_SOFT);
579 return 0;
580 }
581
582 /* no creation of flow control frames */
583 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
584 return 0;
585
586 /* we reached the specified blocksize so->rxfc.bs */
587 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
588 return 0;
589 }
590
isotp_rcv(struct sk_buff * skb,void * data)591 static void isotp_rcv(struct sk_buff *skb, void *data)
592 {
593 struct sock *sk = (struct sock *)data;
594 struct isotp_sock *so = isotp_sk(sk);
595 struct canfd_frame *cf;
596 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
597 u8 n_pci_type, sf_dl;
598
599 /* Strictly receive only frames with the configured MTU size
600 * => clear separation of CAN2.0 / CAN FD transport channels
601 */
602 if (skb->len != so->ll.mtu)
603 return;
604
605 cf = (struct canfd_frame *)skb->data;
606
607 /* if enabled: check reception of my configured extended address */
608 if (ae && cf->data[0] != so->opt.rx_ext_address)
609 return;
610
611 n_pci_type = cf->data[ae] & 0xF0;
612
613 if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
614 /* check rx/tx path half duplex expectations */
615 if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
616 (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
617 return;
618 }
619
620 switch (n_pci_type) {
621 case N_PCI_FC:
622 /* tx path: flow control frame containing the FC parameters */
623 isotp_rcv_fc(so, cf, ae);
624 break;
625
626 case N_PCI_SF:
627 /* rx path: single frame
628 *
629 * As we do not have a rx.ll_dl configuration, we can only test
630 * if the CAN frames payload length matches the LL_DL == 8
631 * requirements - no matter if it's CAN 2.0 or CAN FD
632 */
633
634 /* get the SF_DL from the N_PCI byte */
635 sf_dl = cf->data[ae] & 0x0F;
636
637 if (cf->len <= CAN_MAX_DLEN) {
638 isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
639 } else {
640 if (skb->len == CANFD_MTU) {
641 /* We have a CAN FD frame and CAN_DL is greater than 8:
642 * Only frames with the SF_DL == 0 ESC value are valid.
643 *
644 * If so take care of the increased SF PCI size
645 * (SF_PCI_SZ8) to point to the message content behind
646 * the extended SF PCI info and get the real SF_DL
647 * length value from the formerly first data byte.
648 */
649 if (sf_dl == 0)
650 isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
651 cf->data[SF_PCI_SZ4 + ae]);
652 }
653 }
654 break;
655
656 case N_PCI_FF:
657 /* rx path: first frame */
658 isotp_rcv_ff(sk, cf, ae);
659 break;
660
661 case N_PCI_CF:
662 /* rx path: consecutive frame */
663 isotp_rcv_cf(sk, cf, ae, skb);
664 break;
665 }
666 }
667
isotp_fill_dataframe(struct canfd_frame * cf,struct isotp_sock * so,int ae,int off)668 static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
669 int ae, int off)
670 {
671 int pcilen = N_PCI_SZ + ae + off;
672 int space = so->tx.ll_dl - pcilen;
673 int num = min_t(int, so->tx.len - so->tx.idx, space);
674 int i;
675
676 cf->can_id = so->txid;
677 cf->len = num + pcilen;
678
679 if (num < space) {
680 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
681 /* user requested padding */
682 cf->len = padlen(cf->len);
683 memset(cf->data, so->opt.txpad_content, cf->len);
684 } else if (cf->len > CAN_MAX_DLEN) {
685 /* mandatory padding for CAN FD frames */
686 cf->len = padlen(cf->len);
687 memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
688 cf->len);
689 }
690 }
691
692 for (i = 0; i < num; i++)
693 cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
694
695 if (ae)
696 cf->data[0] = so->opt.ext_address;
697 }
698
isotp_create_fframe(struct canfd_frame * cf,struct isotp_sock * so,int ae)699 static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
700 int ae)
701 {
702 int i;
703 int ff_pci_sz;
704
705 cf->can_id = so->txid;
706 cf->len = so->tx.ll_dl;
707 if (ae)
708 cf->data[0] = so->opt.ext_address;
709
710 /* create N_PCI bytes with 12/32 bit FF_DL data length */
711 if (so->tx.len > 4095) {
712 /* use 32 bit FF_DL notation */
713 cf->data[ae] = N_PCI_FF;
714 cf->data[ae + 1] = 0;
715 cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
716 cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
717 cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
718 cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
719 ff_pci_sz = FF_PCI_SZ32;
720 } else {
721 /* use 12 bit FF_DL notation */
722 cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
723 cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
724 ff_pci_sz = FF_PCI_SZ12;
725 }
726
727 /* add first data bytes depending on ae */
728 for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
729 cf->data[i] = so->tx.buf[so->tx.idx++];
730
731 so->tx.sn = 1;
732 so->tx.state = ISOTP_WAIT_FIRST_FC;
733 }
734
isotp_tx_timer_handler(struct hrtimer * hrtimer)735 static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
736 {
737 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
738 txtimer);
739 struct sock *sk = &so->sk;
740 struct sk_buff *skb;
741 struct net_device *dev;
742 struct canfd_frame *cf;
743 enum hrtimer_restart restart = HRTIMER_NORESTART;
744 int can_send_ret;
745 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
746
747 switch (so->tx.state) {
748 case ISOTP_WAIT_FC:
749 case ISOTP_WAIT_FIRST_FC:
750
751 /* we did not get any flow control frame in time */
752
753 /* report 'communication error on send' */
754 sk->sk_err = ECOMM;
755 if (!sock_flag(sk, SOCK_DEAD))
756 sk->sk_error_report(sk);
757
758 /* reset tx state */
759 so->tx.state = ISOTP_IDLE;
760 wake_up_interruptible(&so->wait);
761 break;
762
763 case ISOTP_SENDING:
764
765 /* push out the next segmented pdu */
766 dev = dev_get_by_index(sock_net(sk), so->ifindex);
767 if (!dev)
768 break;
769
770 isotp_tx_burst:
771 skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
772 GFP_ATOMIC);
773 if (!skb) {
774 dev_put(dev);
775 break;
776 }
777
778 can_skb_reserve(skb);
779 can_skb_prv(skb)->ifindex = dev->ifindex;
780 can_skb_prv(skb)->skbcnt = 0;
781
782 cf = (struct canfd_frame *)skb->data;
783 skb_put(skb, so->ll.mtu);
784
785 /* create consecutive frame */
786 isotp_fill_dataframe(cf, so, ae, 0);
787
788 /* place consecutive frame N_PCI in appropriate index */
789 cf->data[ae] = N_PCI_CF | so->tx.sn++;
790 so->tx.sn %= 16;
791 so->tx.bs++;
792
793 if (so->ll.mtu == CANFD_MTU)
794 cf->flags = so->ll.tx_flags;
795
796 skb->dev = dev;
797 can_skb_set_owner(skb, sk);
798
799 can_send_ret = can_send(skb, 1);
800 if (can_send_ret)
801 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
802 __func__, can_send_ret);
803
804 if (so->tx.idx >= so->tx.len) {
805 /* we are done */
806 so->tx.state = ISOTP_IDLE;
807 dev_put(dev);
808 wake_up_interruptible(&so->wait);
809 break;
810 }
811
812 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
813 /* stop and wait for FC */
814 so->tx.state = ISOTP_WAIT_FC;
815 dev_put(dev);
816 hrtimer_set_expires(&so->txtimer,
817 ktime_add(ktime_get(),
818 ktime_set(1, 0)));
819 restart = HRTIMER_RESTART;
820 break;
821 }
822
823 /* no gap between data frames needed => use burst mode */
824 if (!so->tx_gap)
825 goto isotp_tx_burst;
826
827 /* start timer to send next data frame with correct delay */
828 dev_put(dev);
829 hrtimer_set_expires(&so->txtimer,
830 ktime_add(ktime_get(), so->tx_gap));
831 restart = HRTIMER_RESTART;
832 break;
833
834 default:
835 WARN_ON_ONCE(1);
836 }
837
838 return restart;
839 }
840
isotp_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)841 static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
842 {
843 struct sock *sk = sock->sk;
844 struct isotp_sock *so = isotp_sk(sk);
845 struct sk_buff *skb;
846 struct net_device *dev;
847 struct canfd_frame *cf;
848 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
849 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
850 int off;
851 int err;
852
853 if (!so->bound)
854 return -EADDRNOTAVAIL;
855
856 /* we do not support multiple buffers - for now */
857 if (so->tx.state != ISOTP_IDLE || wq_has_sleeper(&so->wait)) {
858 if (msg->msg_flags & MSG_DONTWAIT)
859 return -EAGAIN;
860
861 /* wait for complete transmission of current pdu */
862 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
863 }
864
865 if (!size || size > MAX_MSG_LENGTH)
866 return -EINVAL;
867
868 err = memcpy_from_msg(so->tx.buf, msg, size);
869 if (err < 0)
870 return err;
871
872 dev = dev_get_by_index(sock_net(sk), so->ifindex);
873 if (!dev)
874 return -ENXIO;
875
876 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
877 msg->msg_flags & MSG_DONTWAIT, &err);
878 if (!skb) {
879 dev_put(dev);
880 return err;
881 }
882
883 can_skb_reserve(skb);
884 can_skb_prv(skb)->ifindex = dev->ifindex;
885 can_skb_prv(skb)->skbcnt = 0;
886
887 so->tx.state = ISOTP_SENDING;
888 so->tx.len = size;
889 so->tx.idx = 0;
890
891 cf = (struct canfd_frame *)skb->data;
892 skb_put(skb, so->ll.mtu);
893
894 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
895 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
896
897 /* check for single frame transmission depending on TX_DL */
898 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
899 /* The message size generally fits into a SingleFrame - good.
900 *
901 * SF_DL ESC offset optimization:
902 *
903 * When TX_DL is greater 8 but the message would still fit
904 * into a 8 byte CAN frame, we can omit the offset.
905 * This prevents a protocol caused length extension from
906 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
907 */
908 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
909 off = 0;
910
911 isotp_fill_dataframe(cf, so, ae, off);
912
913 /* place single frame N_PCI w/o length in appropriate index */
914 cf->data[ae] = N_PCI_SF;
915
916 /* place SF_DL size value depending on the SF_DL ESC offset */
917 if (off)
918 cf->data[SF_PCI_SZ4 + ae] = size;
919 else
920 cf->data[ae] |= size;
921
922 so->tx.state = ISOTP_IDLE;
923 wake_up_interruptible(&so->wait);
924
925 /* don't enable wait queue for a single frame transmission */
926 wait_tx_done = 0;
927 } else {
928 /* send first frame and wait for FC */
929
930 isotp_create_fframe(cf, so, ae);
931
932 /* start timeout for FC */
933 hrtimer_start(&so->txtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
934 }
935
936 /* send the first or only CAN frame */
937 if (so->ll.mtu == CANFD_MTU)
938 cf->flags = so->ll.tx_flags;
939
940 skb->dev = dev;
941 skb->sk = sk;
942 err = can_send(skb, 1);
943 dev_put(dev);
944 if (err) {
945 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
946 __func__, err);
947 return err;
948 }
949
950 if (wait_tx_done) {
951 /* wait for complete transmission of current pdu */
952 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
953 }
954
955 return size;
956 }
957
isotp_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)958 static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
959 int flags)
960 {
961 struct sock *sk = sock->sk;
962 struct sk_buff *skb;
963 int err = 0;
964 int noblock;
965
966 noblock = flags & MSG_DONTWAIT;
967 flags &= ~MSG_DONTWAIT;
968
969 skb = skb_recv_datagram(sk, flags, noblock, &err);
970 if (!skb)
971 return err;
972
973 if (size < skb->len)
974 msg->msg_flags |= MSG_TRUNC;
975 else
976 size = skb->len;
977
978 err = memcpy_to_msg(msg, skb->data, size);
979 if (err < 0) {
980 skb_free_datagram(sk, skb);
981 return err;
982 }
983
984 sock_recv_timestamp(msg, sk, skb);
985
986 if (msg->msg_name) {
987 msg->msg_namelen = sizeof(struct sockaddr_can);
988 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
989 }
990
991 skb_free_datagram(sk, skb);
992
993 return size;
994 }
995
isotp_release(struct socket * sock)996 static int isotp_release(struct socket *sock)
997 {
998 struct sock *sk = sock->sk;
999 struct isotp_sock *so;
1000 struct net *net;
1001
1002 if (!sk)
1003 return 0;
1004
1005 so = isotp_sk(sk);
1006 net = sock_net(sk);
1007
1008 /* wait for complete transmission of current pdu */
1009 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1010
1011 unregister_netdevice_notifier(&so->notifier);
1012
1013 lock_sock(sk);
1014
1015 hrtimer_cancel(&so->txtimer);
1016 hrtimer_cancel(&so->rxtimer);
1017
1018 /* remove current filters & unregister */
1019 if (so->bound) {
1020 if (so->ifindex) {
1021 struct net_device *dev;
1022
1023 dev = dev_get_by_index(net, so->ifindex);
1024 if (dev) {
1025 can_rx_unregister(net, dev, so->rxid,
1026 SINGLE_MASK(so->rxid),
1027 isotp_rcv, sk);
1028 dev_put(dev);
1029 }
1030 }
1031 }
1032
1033 so->ifindex = 0;
1034 so->bound = 0;
1035
1036 sock_orphan(sk);
1037 sock->sk = NULL;
1038
1039 release_sock(sk);
1040 sock_put(sk);
1041
1042 return 0;
1043 }
1044
isotp_bind(struct socket * sock,struct sockaddr * uaddr,int len)1045 static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1046 {
1047 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1048 struct sock *sk = sock->sk;
1049 struct isotp_sock *so = isotp_sk(sk);
1050 struct net *net = sock_net(sk);
1051 int ifindex;
1052 struct net_device *dev;
1053 int err = 0;
1054 int notify_enetdown = 0;
1055
1056 if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp))
1057 return -EINVAL;
1058
1059 if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)
1060 return -EADDRNOTAVAIL;
1061
1062 if ((addr->can_addr.tp.rx_id | addr->can_addr.tp.tx_id) &
1063 (CAN_ERR_FLAG | CAN_RTR_FLAG))
1064 return -EADDRNOTAVAIL;
1065
1066 if (!addr->can_ifindex)
1067 return -ENODEV;
1068
1069 lock_sock(sk);
1070
1071 if (so->bound && addr->can_ifindex == so->ifindex &&
1072 addr->can_addr.tp.rx_id == so->rxid &&
1073 addr->can_addr.tp.tx_id == so->txid)
1074 goto out;
1075
1076 dev = dev_get_by_index(net, addr->can_ifindex);
1077 if (!dev) {
1078 err = -ENODEV;
1079 goto out;
1080 }
1081 if (dev->type != ARPHRD_CAN) {
1082 dev_put(dev);
1083 err = -ENODEV;
1084 goto out;
1085 }
1086 if (dev->mtu < so->ll.mtu) {
1087 dev_put(dev);
1088 err = -EINVAL;
1089 goto out;
1090 }
1091 if (!(dev->flags & IFF_UP))
1092 notify_enetdown = 1;
1093
1094 ifindex = dev->ifindex;
1095
1096 can_rx_register(net, dev, addr->can_addr.tp.rx_id,
1097 SINGLE_MASK(addr->can_addr.tp.rx_id), isotp_rcv, sk,
1098 "isotp", sk);
1099
1100 dev_put(dev);
1101
1102 if (so->bound) {
1103 /* unregister old filter */
1104 if (so->ifindex) {
1105 dev = dev_get_by_index(net, so->ifindex);
1106 if (dev) {
1107 can_rx_unregister(net, dev, so->rxid,
1108 SINGLE_MASK(so->rxid),
1109 isotp_rcv, sk);
1110 dev_put(dev);
1111 }
1112 }
1113 }
1114
1115 /* switch to new settings */
1116 so->ifindex = ifindex;
1117 so->rxid = addr->can_addr.tp.rx_id;
1118 so->txid = addr->can_addr.tp.tx_id;
1119 so->bound = 1;
1120
1121 out:
1122 release_sock(sk);
1123
1124 if (notify_enetdown) {
1125 sk->sk_err = ENETDOWN;
1126 if (!sock_flag(sk, SOCK_DEAD))
1127 sk->sk_error_report(sk);
1128 }
1129
1130 return err;
1131 }
1132
isotp_getname(struct socket * sock,struct sockaddr * uaddr,int peer)1133 static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1134 {
1135 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1136 struct sock *sk = sock->sk;
1137 struct isotp_sock *so = isotp_sk(sk);
1138
1139 if (peer)
1140 return -EOPNOTSUPP;
1141
1142 addr->can_family = AF_CAN;
1143 addr->can_ifindex = so->ifindex;
1144 addr->can_addr.tp.rx_id = so->rxid;
1145 addr->can_addr.tp.tx_id = so->txid;
1146
1147 return sizeof(*addr);
1148 }
1149
isotp_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1150 static int isotp_setsockopt(struct socket *sock, int level, int optname,
1151 sockptr_t optval, unsigned int optlen)
1152 {
1153 struct sock *sk = sock->sk;
1154 struct isotp_sock *so = isotp_sk(sk);
1155 int ret = 0;
1156
1157 if (level != SOL_CAN_ISOTP)
1158 return -EINVAL;
1159
1160 if (so->bound)
1161 return -EISCONN;
1162
1163 switch (optname) {
1164 case CAN_ISOTP_OPTS:
1165 if (optlen != sizeof(struct can_isotp_options))
1166 return -EINVAL;
1167
1168 if (copy_from_sockptr(&so->opt, optval, optlen))
1169 return -EFAULT;
1170
1171 /* no separate rx_ext_address is given => use ext_address */
1172 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1173 so->opt.rx_ext_address = so->opt.ext_address;
1174 break;
1175
1176 case CAN_ISOTP_RECV_FC:
1177 if (optlen != sizeof(struct can_isotp_fc_options))
1178 return -EINVAL;
1179
1180 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1181 return -EFAULT;
1182 break;
1183
1184 case CAN_ISOTP_TX_STMIN:
1185 if (optlen != sizeof(u32))
1186 return -EINVAL;
1187
1188 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1189 return -EFAULT;
1190 break;
1191
1192 case CAN_ISOTP_RX_STMIN:
1193 if (optlen != sizeof(u32))
1194 return -EINVAL;
1195
1196 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1197 return -EFAULT;
1198 break;
1199
1200 case CAN_ISOTP_LL_OPTS:
1201 if (optlen == sizeof(struct can_isotp_ll_options)) {
1202 struct can_isotp_ll_options ll;
1203
1204 if (copy_from_sockptr(&ll, optval, optlen))
1205 return -EFAULT;
1206
1207 /* check for correct ISO 11898-1 DLC data length */
1208 if (ll.tx_dl != padlen(ll.tx_dl))
1209 return -EINVAL;
1210
1211 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1212 return -EINVAL;
1213
1214 if (ll.mtu == CAN_MTU && ll.tx_dl > CAN_MAX_DLEN)
1215 return -EINVAL;
1216
1217 memcpy(&so->ll, &ll, sizeof(ll));
1218
1219 /* set ll_dl for tx path to similar place as for rx */
1220 so->tx.ll_dl = ll.tx_dl;
1221 } else {
1222 return -EINVAL;
1223 }
1224 break;
1225
1226 default:
1227 ret = -ENOPROTOOPT;
1228 }
1229
1230 return ret;
1231 }
1232
isotp_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)1233 static int isotp_getsockopt(struct socket *sock, int level, int optname,
1234 char __user *optval, int __user *optlen)
1235 {
1236 struct sock *sk = sock->sk;
1237 struct isotp_sock *so = isotp_sk(sk);
1238 int len;
1239 void *val;
1240
1241 if (level != SOL_CAN_ISOTP)
1242 return -EINVAL;
1243 if (get_user(len, optlen))
1244 return -EFAULT;
1245 if (len < 0)
1246 return -EINVAL;
1247
1248 switch (optname) {
1249 case CAN_ISOTP_OPTS:
1250 len = min_t(int, len, sizeof(struct can_isotp_options));
1251 val = &so->opt;
1252 break;
1253
1254 case CAN_ISOTP_RECV_FC:
1255 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1256 val = &so->rxfc;
1257 break;
1258
1259 case CAN_ISOTP_TX_STMIN:
1260 len = min_t(int, len, sizeof(u32));
1261 val = &so->force_tx_stmin;
1262 break;
1263
1264 case CAN_ISOTP_RX_STMIN:
1265 len = min_t(int, len, sizeof(u32));
1266 val = &so->force_rx_stmin;
1267 break;
1268
1269 case CAN_ISOTP_LL_OPTS:
1270 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1271 val = &so->ll;
1272 break;
1273
1274 default:
1275 return -ENOPROTOOPT;
1276 }
1277
1278 if (put_user(len, optlen))
1279 return -EFAULT;
1280 if (copy_to_user(optval, val, len))
1281 return -EFAULT;
1282 return 0;
1283 }
1284
isotp_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)1285 static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1286 void *ptr)
1287 {
1288 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1289 struct isotp_sock *so = container_of(nb, struct isotp_sock, notifier);
1290 struct sock *sk = &so->sk;
1291
1292 if (!net_eq(dev_net(dev), sock_net(sk)))
1293 return NOTIFY_DONE;
1294
1295 if (dev->type != ARPHRD_CAN)
1296 return NOTIFY_DONE;
1297
1298 if (so->ifindex != dev->ifindex)
1299 return NOTIFY_DONE;
1300
1301 switch (msg) {
1302 case NETDEV_UNREGISTER:
1303 lock_sock(sk);
1304 /* remove current filters & unregister */
1305 if (so->bound)
1306 can_rx_unregister(dev_net(dev), dev, so->rxid,
1307 SINGLE_MASK(so->rxid),
1308 isotp_rcv, sk);
1309
1310 so->ifindex = 0;
1311 so->bound = 0;
1312 release_sock(sk);
1313
1314 sk->sk_err = ENODEV;
1315 if (!sock_flag(sk, SOCK_DEAD))
1316 sk->sk_error_report(sk);
1317 break;
1318
1319 case NETDEV_DOWN:
1320 sk->sk_err = ENETDOWN;
1321 if (!sock_flag(sk, SOCK_DEAD))
1322 sk->sk_error_report(sk);
1323 break;
1324 }
1325
1326 return NOTIFY_DONE;
1327 }
1328
isotp_init(struct sock * sk)1329 static int isotp_init(struct sock *sk)
1330 {
1331 struct isotp_sock *so = isotp_sk(sk);
1332
1333 so->ifindex = 0;
1334 so->bound = 0;
1335
1336 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1337 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1338 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1339 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1340 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1341 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1342 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1343 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1344 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1345 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1346 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1347 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1348
1349 /* set ll_dl for tx path to similar place as for rx */
1350 so->tx.ll_dl = so->ll.tx_dl;
1351
1352 so->rx.state = ISOTP_IDLE;
1353 so->tx.state = ISOTP_IDLE;
1354
1355 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1356 so->rxtimer.function = isotp_rx_timer_handler;
1357 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1358 so->txtimer.function = isotp_tx_timer_handler;
1359
1360 init_waitqueue_head(&so->wait);
1361
1362 so->notifier.notifier_call = isotp_notifier;
1363 register_netdevice_notifier(&so->notifier);
1364
1365 return 0;
1366 }
1367
isotp_sock_no_ioctlcmd(struct socket * sock,unsigned int cmd,unsigned long arg)1368 static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1369 unsigned long arg)
1370 {
1371 /* no ioctls for socket layer -> hand it down to NIC layer */
1372 return -ENOIOCTLCMD;
1373 }
1374
1375 static const struct proto_ops isotp_ops = {
1376 .family = PF_CAN,
1377 .release = isotp_release,
1378 .bind = isotp_bind,
1379 .connect = sock_no_connect,
1380 .socketpair = sock_no_socketpair,
1381 .accept = sock_no_accept,
1382 .getname = isotp_getname,
1383 .poll = datagram_poll,
1384 .ioctl = isotp_sock_no_ioctlcmd,
1385 .gettstamp = sock_gettstamp,
1386 .listen = sock_no_listen,
1387 .shutdown = sock_no_shutdown,
1388 .setsockopt = isotp_setsockopt,
1389 .getsockopt = isotp_getsockopt,
1390 .sendmsg = isotp_sendmsg,
1391 .recvmsg = isotp_recvmsg,
1392 .mmap = sock_no_mmap,
1393 .sendpage = sock_no_sendpage,
1394 };
1395
1396 static struct proto isotp_proto __read_mostly = {
1397 .name = "CAN_ISOTP",
1398 .owner = THIS_MODULE,
1399 .obj_size = sizeof(struct isotp_sock),
1400 .init = isotp_init,
1401 };
1402
1403 static const struct can_proto isotp_can_proto = {
1404 .type = SOCK_DGRAM,
1405 .protocol = CAN_ISOTP,
1406 .ops = &isotp_ops,
1407 .prot = &isotp_proto,
1408 };
1409
isotp_module_init(void)1410 static __init int isotp_module_init(void)
1411 {
1412 int err;
1413
1414 pr_info("can: isotp protocol\n");
1415
1416 err = can_proto_register(&isotp_can_proto);
1417 if (err < 0)
1418 pr_err("can: registration of isotp protocol failed\n");
1419
1420 return err;
1421 }
1422
isotp_module_exit(void)1423 static __exit void isotp_module_exit(void)
1424 {
1425 can_proto_unregister(&isotp_can_proto);
1426 }
1427
1428 module_init(isotp_module_init);
1429 module_exit(isotp_module_exit);
1430
