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 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 8 kbyte to be able to test this new functionality.
90 */
91 #define MAX_MSG_LENGTH 8200
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
108 /* Flow Status given in FC frame */
109 #define ISOTP_FC_CTS 0 /* clear to send */
110 #define ISOTP_FC_WT 1 /* wait */
111 #define ISOTP_FC_OVFLW 2 /* overflow */
112
113 enum {
114 ISOTP_IDLE = 0,
115 ISOTP_WAIT_FIRST_FC,
116 ISOTP_WAIT_FC,
117 ISOTP_WAIT_DATA,
118 ISOTP_SENDING
119 };
120
121 struct tpcon {
122 unsigned int idx;
123 unsigned int len;
124 u32 state;
125 u8 bs;
126 u8 sn;
127 u8 ll_dl;
128 u8 buf[MAX_MSG_LENGTH + 1];
129 };
130
131 struct isotp_sock {
132 struct sock sk;
133 int bound;
134 int ifindex;
135 canid_t txid;
136 canid_t rxid;
137 ktime_t tx_gap;
138 ktime_t lastrxcf_tstamp;
139 struct hrtimer rxtimer, txtimer;
140 struct can_isotp_options opt;
141 struct can_isotp_fc_options rxfc, txfc;
142 struct can_isotp_ll_options ll;
143 u32 force_tx_stmin;
144 u32 force_rx_stmin;
145 struct tpcon rx, tx;
146 struct list_head notifier;
147 wait_queue_head_t wait;
148 };
149
150 static LIST_HEAD(isotp_notifier_list);
151 static DEFINE_SPINLOCK(isotp_notifier_lock);
152 static struct isotp_sock *isotp_busy_notifier;
153
isotp_sk(const struct sock * sk)154 static inline struct isotp_sock *isotp_sk(const struct sock *sk)
155 {
156 return (struct isotp_sock *)sk;
157 }
158
isotp_rx_timer_handler(struct hrtimer * hrtimer)159 static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
160 {
161 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
162 rxtimer);
163 struct sock *sk = &so->sk;
164
165 if (so->rx.state == ISOTP_WAIT_DATA) {
166 /* we did not get new data frames in time */
167
168 /* report 'connection timed out' */
169 sk->sk_err = ETIMEDOUT;
170 if (!sock_flag(sk, SOCK_DEAD))
171 sk->sk_error_report(sk);
172
173 /* reset rx state */
174 so->rx.state = ISOTP_IDLE;
175 }
176
177 return HRTIMER_NORESTART;
178 }
179
isotp_send_fc(struct sock * sk,int ae,u8 flowstatus)180 static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
181 {
182 struct net_device *dev;
183 struct sk_buff *nskb;
184 struct canfd_frame *ncf;
185 struct isotp_sock *so = isotp_sk(sk);
186 int can_send_ret;
187
188 nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
189 if (!nskb)
190 return 1;
191
192 dev = dev_get_by_index(sock_net(sk), so->ifindex);
193 if (!dev) {
194 kfree_skb(nskb);
195 return 1;
196 }
197
198 can_skb_reserve(nskb);
199 can_skb_prv(nskb)->ifindex = dev->ifindex;
200 can_skb_prv(nskb)->skbcnt = 0;
201
202 nskb->dev = dev;
203 can_skb_set_owner(nskb, sk);
204 ncf = (struct canfd_frame *)nskb->data;
205 skb_put_zero(nskb, so->ll.mtu);
206
207 /* create & send flow control reply */
208 ncf->can_id = so->txid;
209
210 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
211 memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
212 ncf->len = CAN_MAX_DLEN;
213 } else {
214 ncf->len = ae + FC_CONTENT_SZ;
215 }
216
217 ncf->data[ae] = N_PCI_FC | flowstatus;
218 ncf->data[ae + 1] = so->rxfc.bs;
219 ncf->data[ae + 2] = so->rxfc.stmin;
220
221 if (ae)
222 ncf->data[0] = so->opt.ext_address;
223
224 ncf->flags = so->ll.tx_flags;
225
226 can_send_ret = can_send(nskb, 1);
227 if (can_send_ret)
228 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
229 __func__, can_send_ret);
230
231 dev_put(dev);
232
233 /* reset blocksize counter */
234 so->rx.bs = 0;
235
236 /* reset last CF frame rx timestamp for rx stmin enforcement */
237 so->lastrxcf_tstamp = ktime_set(0, 0);
238
239 /* start rx timeout watchdog */
240 hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
241 return 0;
242 }
243
isotp_rcv_skb(struct sk_buff * skb,struct sock * sk)244 static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
245 {
246 struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
247
248 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
249
250 memset(addr, 0, sizeof(*addr));
251 addr->can_family = AF_CAN;
252 addr->can_ifindex = skb->dev->ifindex;
253
254 if (sock_queue_rcv_skb(sk, skb) < 0)
255 kfree_skb(skb);
256 }
257
padlen(u8 datalen)258 static u8 padlen(u8 datalen)
259 {
260 static const u8 plen[] = {
261 8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
262 12, 12, 12, 12, /* 9 - 12 */
263 16, 16, 16, 16, /* 13 - 16 */
264 20, 20, 20, 20, /* 17 - 20 */
265 24, 24, 24, 24, /* 21 - 24 */
266 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
267 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
268 48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
269 };
270
271 if (datalen > 48)
272 return 64;
273
274 return plen[datalen];
275 }
276
277 /* check for length optimization and return 1/true when the check fails */
check_optimized(struct canfd_frame * cf,int start_index)278 static int check_optimized(struct canfd_frame *cf, int start_index)
279 {
280 /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
281 * padding would start at this point. E.g. if the padding would
282 * start at cf.data[7] cf->len has to be 7 to be optimal.
283 * Note: The data[] index starts with zero.
284 */
285 if (cf->len <= CAN_MAX_DLEN)
286 return (cf->len != start_index);
287
288 /* This relation is also valid in the non-linear DLC range, where
289 * we need to take care of the minimal next possible CAN_DL.
290 * The correct check would be (padlen(cf->len) != padlen(start_index)).
291 * But as cf->len can only take discrete values from 12, .., 64 at this
292 * point the padlen(cf->len) is always equal to cf->len.
293 */
294 return (cf->len != padlen(start_index));
295 }
296
297 /* 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)298 static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
299 int start_index, u8 content)
300 {
301 int i;
302
303 /* no RX_PADDING value => check length of optimized frame length */
304 if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
305 if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
306 return check_optimized(cf, start_index);
307
308 /* no valid test against empty value => ignore frame */
309 return 1;
310 }
311
312 /* check datalength of correctly padded CAN frame */
313 if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
314 cf->len != padlen(cf->len))
315 return 1;
316
317 /* check padding content */
318 if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
319 for (i = start_index; i < cf->len; i++)
320 if (cf->data[i] != content)
321 return 1;
322 }
323 return 0;
324 }
325
isotp_rcv_fc(struct isotp_sock * so,struct canfd_frame * cf,int ae)326 static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
327 {
328 struct sock *sk = &so->sk;
329
330 if (so->tx.state != ISOTP_WAIT_FC &&
331 so->tx.state != ISOTP_WAIT_FIRST_FC)
332 return 0;
333
334 hrtimer_cancel(&so->txtimer);
335
336 if ((cf->len < ae + FC_CONTENT_SZ) ||
337 ((so->opt.flags & ISOTP_CHECK_PADDING) &&
338 check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
339 /* malformed PDU - report 'not a data message' */
340 sk->sk_err = EBADMSG;
341 if (!sock_flag(sk, SOCK_DEAD))
342 sk->sk_error_report(sk);
343
344 so->tx.state = ISOTP_IDLE;
345 wake_up_interruptible(&so->wait);
346 return 1;
347 }
348
349 /* get communication parameters only from the first FC frame */
350 if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
351 so->txfc.bs = cf->data[ae + 1];
352 so->txfc.stmin = cf->data[ae + 2];
353
354 /* fix wrong STmin values according spec */
355 if (so->txfc.stmin > 0x7F &&
356 (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
357 so->txfc.stmin = 0x7F;
358
359 so->tx_gap = ktime_set(0, 0);
360 /* add transmission time for CAN frame N_As */
361 so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
362 /* add waiting time for consecutive frames N_Cs */
363 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
364 so->tx_gap = ktime_add_ns(so->tx_gap,
365 so->force_tx_stmin);
366 else if (so->txfc.stmin < 0x80)
367 so->tx_gap = ktime_add_ns(so->tx_gap,
368 so->txfc.stmin * 1000000);
369 else
370 so->tx_gap = ktime_add_ns(so->tx_gap,
371 (so->txfc.stmin - 0xF0)
372 * 100000);
373 so->tx.state = ISOTP_WAIT_FC;
374 }
375
376 switch (cf->data[ae] & 0x0F) {
377 case ISOTP_FC_CTS:
378 so->tx.bs = 0;
379 so->tx.state = ISOTP_SENDING;
380 /* start cyclic timer for sending CF frame */
381 hrtimer_start(&so->txtimer, so->tx_gap,
382 HRTIMER_MODE_REL_SOFT);
383 break;
384
385 case ISOTP_FC_WT:
386 /* start timer to wait for next FC frame */
387 hrtimer_start(&so->txtimer, ktime_set(1, 0),
388 HRTIMER_MODE_REL_SOFT);
389 break;
390
391 case ISOTP_FC_OVFLW:
392 /* overflow on receiver side - report 'message too long' */
393 sk->sk_err = EMSGSIZE;
394 if (!sock_flag(sk, SOCK_DEAD))
395 sk->sk_error_report(sk);
396 fallthrough;
397
398 default:
399 /* stop this tx job */
400 so->tx.state = ISOTP_IDLE;
401 wake_up_interruptible(&so->wait);
402 }
403 return 0;
404 }
405
isotp_rcv_sf(struct sock * sk,struct canfd_frame * cf,int pcilen,struct sk_buff * skb,int len)406 static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
407 struct sk_buff *skb, int len)
408 {
409 struct isotp_sock *so = isotp_sk(sk);
410 struct sk_buff *nskb;
411
412 hrtimer_cancel(&so->rxtimer);
413 so->rx.state = ISOTP_IDLE;
414
415 if (!len || len > cf->len - pcilen)
416 return 1;
417
418 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
419 check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
420 /* malformed PDU - report 'not a data message' */
421 sk->sk_err = EBADMSG;
422 if (!sock_flag(sk, SOCK_DEAD))
423 sk->sk_error_report(sk);
424 return 1;
425 }
426
427 nskb = alloc_skb(len, gfp_any());
428 if (!nskb)
429 return 1;
430
431 memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
432
433 nskb->tstamp = skb->tstamp;
434 nskb->dev = skb->dev;
435 isotp_rcv_skb(nskb, sk);
436 return 0;
437 }
438
isotp_rcv_ff(struct sock * sk,struct canfd_frame * cf,int ae)439 static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
440 {
441 struct isotp_sock *so = isotp_sk(sk);
442 int i;
443 int off;
444 int ff_pci_sz;
445
446 hrtimer_cancel(&so->rxtimer);
447 so->rx.state = ISOTP_IDLE;
448
449 /* get the used sender LL_DL from the (first) CAN frame data length */
450 so->rx.ll_dl = padlen(cf->len);
451
452 /* the first frame has to use the entire frame up to LL_DL length */
453 if (cf->len != so->rx.ll_dl)
454 return 1;
455
456 /* get the FF_DL */
457 so->rx.len = (cf->data[ae] & 0x0F) << 8;
458 so->rx.len += cf->data[ae + 1];
459
460 /* Check for FF_DL escape sequence supporting 32 bit PDU length */
461 if (so->rx.len) {
462 ff_pci_sz = FF_PCI_SZ12;
463 } else {
464 /* FF_DL = 0 => get real length from next 4 bytes */
465 so->rx.len = cf->data[ae + 2] << 24;
466 so->rx.len += cf->data[ae + 3] << 16;
467 so->rx.len += cf->data[ae + 4] << 8;
468 so->rx.len += cf->data[ae + 5];
469 ff_pci_sz = FF_PCI_SZ32;
470 }
471
472 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
473 off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
474
475 if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
476 return 1;
477
478 if (so->rx.len > MAX_MSG_LENGTH) {
479 /* send FC frame with overflow status */
480 isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
481 return 1;
482 }
483
484 /* copy the first received data bytes */
485 so->rx.idx = 0;
486 for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
487 so->rx.buf[so->rx.idx++] = cf->data[i];
488
489 /* initial setup for this pdu reception */
490 so->rx.sn = 1;
491 so->rx.state = ISOTP_WAIT_DATA;
492
493 /* no creation of flow control frames */
494 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
495 return 0;
496
497 /* send our first FC frame */
498 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
499 return 0;
500 }
501
isotp_rcv_cf(struct sock * sk,struct canfd_frame * cf,int ae,struct sk_buff * skb)502 static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
503 struct sk_buff *skb)
504 {
505 struct isotp_sock *so = isotp_sk(sk);
506 struct sk_buff *nskb;
507 int i;
508
509 if (so->rx.state != ISOTP_WAIT_DATA)
510 return 0;
511
512 /* drop if timestamp gap is less than force_rx_stmin nano secs */
513 if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
514 if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
515 so->force_rx_stmin)
516 return 0;
517
518 so->lastrxcf_tstamp = skb->tstamp;
519 }
520
521 hrtimer_cancel(&so->rxtimer);
522
523 /* CFs are never longer than the FF */
524 if (cf->len > so->rx.ll_dl)
525 return 1;
526
527 /* CFs have usually the LL_DL length */
528 if (cf->len < so->rx.ll_dl) {
529 /* this is only allowed for the last CF */
530 if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
531 return 1;
532 }
533
534 if ((cf->data[ae] & 0x0F) != so->rx.sn) {
535 /* wrong sn detected - report 'illegal byte sequence' */
536 sk->sk_err = EILSEQ;
537 if (!sock_flag(sk, SOCK_DEAD))
538 sk->sk_error_report(sk);
539
540 /* reset rx state */
541 so->rx.state = ISOTP_IDLE;
542 return 1;
543 }
544 so->rx.sn++;
545 so->rx.sn %= 16;
546
547 for (i = ae + N_PCI_SZ; i < cf->len; i++) {
548 so->rx.buf[so->rx.idx++] = cf->data[i];
549 if (so->rx.idx >= so->rx.len)
550 break;
551 }
552
553 if (so->rx.idx >= so->rx.len) {
554 /* we are done */
555 so->rx.state = ISOTP_IDLE;
556
557 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
558 check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
559 /* malformed PDU - report 'not a data message' */
560 sk->sk_err = EBADMSG;
561 if (!sock_flag(sk, SOCK_DEAD))
562 sk->sk_error_report(sk);
563 return 1;
564 }
565
566 nskb = alloc_skb(so->rx.len, gfp_any());
567 if (!nskb)
568 return 1;
569
570 memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
571 so->rx.len);
572
573 nskb->tstamp = skb->tstamp;
574 nskb->dev = skb->dev;
575 isotp_rcv_skb(nskb, sk);
576 return 0;
577 }
578
579 /* perform blocksize handling, if enabled */
580 if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
581 /* start rx timeout watchdog */
582 hrtimer_start(&so->rxtimer, ktime_set(1, 0),
583 HRTIMER_MODE_REL_SOFT);
584 return 0;
585 }
586
587 /* no creation of flow control frames */
588 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
589 return 0;
590
591 /* we reached the specified blocksize so->rxfc.bs */
592 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
593 return 0;
594 }
595
isotp_rcv(struct sk_buff * skb,void * data)596 static void isotp_rcv(struct sk_buff *skb, void *data)
597 {
598 struct sock *sk = (struct sock *)data;
599 struct isotp_sock *so = isotp_sk(sk);
600 struct canfd_frame *cf;
601 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
602 u8 n_pci_type, sf_dl;
603
604 /* Strictly receive only frames with the configured MTU size
605 * => clear separation of CAN2.0 / CAN FD transport channels
606 */
607 if (skb->len != so->ll.mtu)
608 return;
609
610 cf = (struct canfd_frame *)skb->data;
611
612 /* if enabled: check reception of my configured extended address */
613 if (ae && cf->data[0] != so->opt.rx_ext_address)
614 return;
615
616 n_pci_type = cf->data[ae] & 0xF0;
617
618 if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
619 /* check rx/tx path half duplex expectations */
620 if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
621 (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
622 return;
623 }
624
625 switch (n_pci_type) {
626 case N_PCI_FC:
627 /* tx path: flow control frame containing the FC parameters */
628 isotp_rcv_fc(so, cf, ae);
629 break;
630
631 case N_PCI_SF:
632 /* rx path: single frame
633 *
634 * As we do not have a rx.ll_dl configuration, we can only test
635 * if the CAN frames payload length matches the LL_DL == 8
636 * requirements - no matter if it's CAN 2.0 or CAN FD
637 */
638
639 /* get the SF_DL from the N_PCI byte */
640 sf_dl = cf->data[ae] & 0x0F;
641
642 if (cf->len <= CAN_MAX_DLEN) {
643 isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
644 } else {
645 if (skb->len == CANFD_MTU) {
646 /* We have a CAN FD frame and CAN_DL is greater than 8:
647 * Only frames with the SF_DL == 0 ESC value are valid.
648 *
649 * If so take care of the increased SF PCI size
650 * (SF_PCI_SZ8) to point to the message content behind
651 * the extended SF PCI info and get the real SF_DL
652 * length value from the formerly first data byte.
653 */
654 if (sf_dl == 0)
655 isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
656 cf->data[SF_PCI_SZ4 + ae]);
657 }
658 }
659 break;
660
661 case N_PCI_FF:
662 /* rx path: first frame */
663 isotp_rcv_ff(sk, cf, ae);
664 break;
665
666 case N_PCI_CF:
667 /* rx path: consecutive frame */
668 isotp_rcv_cf(sk, cf, ae, skb);
669 break;
670 }
671 }
672
isotp_fill_dataframe(struct canfd_frame * cf,struct isotp_sock * so,int ae,int off)673 static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
674 int ae, int off)
675 {
676 int pcilen = N_PCI_SZ + ae + off;
677 int space = so->tx.ll_dl - pcilen;
678 int num = min_t(int, so->tx.len - so->tx.idx, space);
679 int i;
680
681 cf->can_id = so->txid;
682 cf->len = num + pcilen;
683
684 if (num < space) {
685 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
686 /* user requested padding */
687 cf->len = padlen(cf->len);
688 memset(cf->data, so->opt.txpad_content, cf->len);
689 } else if (cf->len > CAN_MAX_DLEN) {
690 /* mandatory padding for CAN FD frames */
691 cf->len = padlen(cf->len);
692 memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
693 cf->len);
694 }
695 }
696
697 for (i = 0; i < num; i++)
698 cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
699
700 if (ae)
701 cf->data[0] = so->opt.ext_address;
702 }
703
isotp_create_fframe(struct canfd_frame * cf,struct isotp_sock * so,int ae)704 static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
705 int ae)
706 {
707 int i;
708 int ff_pci_sz;
709
710 cf->can_id = so->txid;
711 cf->len = so->tx.ll_dl;
712 if (ae)
713 cf->data[0] = so->opt.ext_address;
714
715 /* create N_PCI bytes with 12/32 bit FF_DL data length */
716 if (so->tx.len > 4095) {
717 /* use 32 bit FF_DL notation */
718 cf->data[ae] = N_PCI_FF;
719 cf->data[ae + 1] = 0;
720 cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
721 cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
722 cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
723 cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
724 ff_pci_sz = FF_PCI_SZ32;
725 } else {
726 /* use 12 bit FF_DL notation */
727 cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
728 cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
729 ff_pci_sz = FF_PCI_SZ12;
730 }
731
732 /* add first data bytes depending on ae */
733 for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
734 cf->data[i] = so->tx.buf[so->tx.idx++];
735
736 so->tx.sn = 1;
737 so->tx.state = ISOTP_WAIT_FIRST_FC;
738 }
739
isotp_tx_timer_handler(struct hrtimer * hrtimer)740 static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
741 {
742 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
743 txtimer);
744 struct sock *sk = &so->sk;
745 struct sk_buff *skb;
746 struct net_device *dev;
747 struct canfd_frame *cf;
748 enum hrtimer_restart restart = HRTIMER_NORESTART;
749 int can_send_ret;
750 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
751
752 switch (so->tx.state) {
753 case ISOTP_WAIT_FC:
754 case ISOTP_WAIT_FIRST_FC:
755
756 /* we did not get any flow control frame in time */
757
758 /* report 'communication error on send' */
759 sk->sk_err = ECOMM;
760 if (!sock_flag(sk, SOCK_DEAD))
761 sk->sk_error_report(sk);
762
763 /* reset tx state */
764 so->tx.state = ISOTP_IDLE;
765 wake_up_interruptible(&so->wait);
766 break;
767
768 case ISOTP_SENDING:
769
770 /* push out the next segmented pdu */
771 dev = dev_get_by_index(sock_net(sk), so->ifindex);
772 if (!dev)
773 break;
774
775 isotp_tx_burst:
776 skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
777 GFP_ATOMIC);
778 if (!skb) {
779 dev_put(dev);
780 break;
781 }
782
783 can_skb_reserve(skb);
784 can_skb_prv(skb)->ifindex = dev->ifindex;
785 can_skb_prv(skb)->skbcnt = 0;
786
787 cf = (struct canfd_frame *)skb->data;
788 skb_put_zero(skb, so->ll.mtu);
789
790 /* create consecutive frame */
791 isotp_fill_dataframe(cf, so, ae, 0);
792
793 /* place consecutive frame N_PCI in appropriate index */
794 cf->data[ae] = N_PCI_CF | so->tx.sn++;
795 so->tx.sn %= 16;
796 so->tx.bs++;
797
798 cf->flags = so->ll.tx_flags;
799
800 skb->dev = dev;
801 can_skb_set_owner(skb, sk);
802
803 can_send_ret = can_send(skb, 1);
804 if (can_send_ret)
805 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
806 __func__, can_send_ret);
807
808 if (so->tx.idx >= so->tx.len) {
809 /* we are done */
810 so->tx.state = ISOTP_IDLE;
811 dev_put(dev);
812 wake_up_interruptible(&so->wait);
813 break;
814 }
815
816 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
817 /* stop and wait for FC */
818 so->tx.state = ISOTP_WAIT_FC;
819 dev_put(dev);
820 hrtimer_set_expires(&so->txtimer,
821 ktime_add(ktime_get(),
822 ktime_set(1, 0)));
823 restart = HRTIMER_RESTART;
824 break;
825 }
826
827 /* no gap between data frames needed => use burst mode */
828 if (!so->tx_gap)
829 goto isotp_tx_burst;
830
831 /* start timer to send next data frame with correct delay */
832 dev_put(dev);
833 hrtimer_set_expires(&so->txtimer,
834 ktime_add(ktime_get(), so->tx_gap));
835 restart = HRTIMER_RESTART;
836 break;
837
838 default:
839 WARN_ON_ONCE(1);
840 }
841
842 return restart;
843 }
844
isotp_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)845 static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
846 {
847 struct sock *sk = sock->sk;
848 struct isotp_sock *so = isotp_sk(sk);
849 u32 old_state = so->tx.state;
850 struct sk_buff *skb;
851 struct net_device *dev;
852 struct canfd_frame *cf;
853 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
854 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
855 int off;
856 int err;
857
858 if (!so->bound)
859 return -EADDRNOTAVAIL;
860
861 /* we do not support multiple buffers - for now */
862 if (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE ||
863 wq_has_sleeper(&so->wait)) {
864 if (msg->msg_flags & MSG_DONTWAIT) {
865 err = -EAGAIN;
866 goto err_out;
867 }
868
869 /* wait for complete transmission of current pdu */
870 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
871 if (err)
872 goto err_out;
873 }
874
875 if (!size || size > MAX_MSG_LENGTH) {
876 err = -EINVAL;
877 goto err_out;
878 }
879
880 err = memcpy_from_msg(so->tx.buf, msg, size);
881 if (err < 0)
882 goto err_out;
883
884 dev = dev_get_by_index(sock_net(sk), so->ifindex);
885 if (!dev) {
886 err = -ENXIO;
887 goto err_out;
888 }
889
890 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
891 msg->msg_flags & MSG_DONTWAIT, &err);
892 if (!skb) {
893 dev_put(dev);
894 goto err_out;
895 }
896
897 can_skb_reserve(skb);
898 can_skb_prv(skb)->ifindex = dev->ifindex;
899 can_skb_prv(skb)->skbcnt = 0;
900
901 so->tx.len = size;
902 so->tx.idx = 0;
903
904 cf = (struct canfd_frame *)skb->data;
905 skb_put_zero(skb, so->ll.mtu);
906
907 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
908 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
909
910 /* check for single frame transmission depending on TX_DL */
911 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
912 /* The message size generally fits into a SingleFrame - good.
913 *
914 * SF_DL ESC offset optimization:
915 *
916 * When TX_DL is greater 8 but the message would still fit
917 * into a 8 byte CAN frame, we can omit the offset.
918 * This prevents a protocol caused length extension from
919 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
920 */
921 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
922 off = 0;
923
924 isotp_fill_dataframe(cf, so, ae, off);
925
926 /* place single frame N_PCI w/o length in appropriate index */
927 cf->data[ae] = N_PCI_SF;
928
929 /* place SF_DL size value depending on the SF_DL ESC offset */
930 if (off)
931 cf->data[SF_PCI_SZ4 + ae] = size;
932 else
933 cf->data[ae] |= size;
934
935 so->tx.state = ISOTP_IDLE;
936 wake_up_interruptible(&so->wait);
937
938 /* don't enable wait queue for a single frame transmission */
939 wait_tx_done = 0;
940 } else {
941 /* send first frame and wait for FC */
942
943 isotp_create_fframe(cf, so, ae);
944
945 /* start timeout for FC */
946 hrtimer_start(&so->txtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
947 }
948
949 /* send the first or only CAN frame */
950 cf->flags = so->ll.tx_flags;
951
952 skb->dev = dev;
953 skb->sk = sk;
954 err = can_send(skb, 1);
955 dev_put(dev);
956 if (err) {
957 pr_notice_once("can-isotp: %s: can_send_ret %d\n",
958 __func__, err);
959 goto err_out;
960 }
961
962 if (wait_tx_done) {
963 /* wait for complete transmission of current pdu */
964 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
965
966 if (sk->sk_err)
967 return -sk->sk_err;
968 }
969
970 return size;
971
972 err_out:
973 so->tx.state = old_state;
974 if (so->tx.state == ISOTP_IDLE)
975 wake_up_interruptible(&so->wait);
976
977 return err;
978 }
979
isotp_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)980 static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
981 int flags)
982 {
983 struct sock *sk = sock->sk;
984 struct sk_buff *skb;
985 int err = 0;
986 int noblock;
987
988 noblock = flags & MSG_DONTWAIT;
989 flags &= ~MSG_DONTWAIT;
990
991 skb = skb_recv_datagram(sk, flags, noblock, &err);
992 if (!skb)
993 return err;
994
995 if (size < skb->len)
996 msg->msg_flags |= MSG_TRUNC;
997 else
998 size = skb->len;
999
1000 err = memcpy_to_msg(msg, skb->data, size);
1001 if (err < 0) {
1002 skb_free_datagram(sk, skb);
1003 return err;
1004 }
1005
1006 sock_recv_timestamp(msg, sk, skb);
1007
1008 if (msg->msg_name) {
1009 __sockaddr_check_size(ISOTP_MIN_NAMELEN);
1010 msg->msg_namelen = ISOTP_MIN_NAMELEN;
1011 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1012 }
1013
1014 skb_free_datagram(sk, skb);
1015
1016 return size;
1017 }
1018
isotp_release(struct socket * sock)1019 static int isotp_release(struct socket *sock)
1020 {
1021 struct sock *sk = sock->sk;
1022 struct isotp_sock *so;
1023 struct net *net;
1024
1025 if (!sk)
1026 return 0;
1027
1028 so = isotp_sk(sk);
1029 net = sock_net(sk);
1030
1031 /* wait for complete transmission of current pdu */
1032 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1033
1034 spin_lock(&isotp_notifier_lock);
1035 while (isotp_busy_notifier == so) {
1036 spin_unlock(&isotp_notifier_lock);
1037 schedule_timeout_uninterruptible(1);
1038 spin_lock(&isotp_notifier_lock);
1039 }
1040 list_del(&so->notifier);
1041 spin_unlock(&isotp_notifier_lock);
1042
1043 lock_sock(sk);
1044
1045 /* remove current filters & unregister */
1046 if (so->bound) {
1047 if (so->ifindex) {
1048 struct net_device *dev;
1049
1050 dev = dev_get_by_index(net, so->ifindex);
1051 if (dev) {
1052 can_rx_unregister(net, dev, so->rxid,
1053 SINGLE_MASK(so->rxid),
1054 isotp_rcv, sk);
1055 dev_put(dev);
1056 synchronize_rcu();
1057 }
1058 }
1059 }
1060
1061 hrtimer_cancel(&so->txtimer);
1062 hrtimer_cancel(&so->rxtimer);
1063
1064 so->ifindex = 0;
1065 so->bound = 0;
1066
1067 sock_orphan(sk);
1068 sock->sk = NULL;
1069
1070 release_sock(sk);
1071 sock_put(sk);
1072
1073 return 0;
1074 }
1075
isotp_bind(struct socket * sock,struct sockaddr * uaddr,int len)1076 static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1077 {
1078 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1079 struct sock *sk = sock->sk;
1080 struct isotp_sock *so = isotp_sk(sk);
1081 struct net *net = sock_net(sk);
1082 int ifindex;
1083 struct net_device *dev;
1084 int err = 0;
1085 int notify_enetdown = 0;
1086
1087 if (len < ISOTP_MIN_NAMELEN)
1088 return -EINVAL;
1089
1090 if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)
1091 return -EADDRNOTAVAIL;
1092
1093 if ((addr->can_addr.tp.rx_id | addr->can_addr.tp.tx_id) &
1094 (CAN_ERR_FLAG | CAN_RTR_FLAG))
1095 return -EADDRNOTAVAIL;
1096
1097 if (!addr->can_ifindex)
1098 return -ENODEV;
1099
1100 lock_sock(sk);
1101
1102 if (so->bound && addr->can_ifindex == so->ifindex &&
1103 addr->can_addr.tp.rx_id == so->rxid &&
1104 addr->can_addr.tp.tx_id == so->txid)
1105 goto out;
1106
1107 dev = dev_get_by_index(net, addr->can_ifindex);
1108 if (!dev) {
1109 err = -ENODEV;
1110 goto out;
1111 }
1112 if (dev->type != ARPHRD_CAN) {
1113 dev_put(dev);
1114 err = -ENODEV;
1115 goto out;
1116 }
1117 if (dev->mtu < so->ll.mtu) {
1118 dev_put(dev);
1119 err = -EINVAL;
1120 goto out;
1121 }
1122 if (!(dev->flags & IFF_UP))
1123 notify_enetdown = 1;
1124
1125 ifindex = dev->ifindex;
1126
1127 can_rx_register(net, dev, addr->can_addr.tp.rx_id,
1128 SINGLE_MASK(addr->can_addr.tp.rx_id), isotp_rcv, sk,
1129 "isotp", sk);
1130
1131 dev_put(dev);
1132
1133 if (so->bound) {
1134 /* unregister old filter */
1135 if (so->ifindex) {
1136 dev = dev_get_by_index(net, so->ifindex);
1137 if (dev) {
1138 can_rx_unregister(net, dev, so->rxid,
1139 SINGLE_MASK(so->rxid),
1140 isotp_rcv, sk);
1141 dev_put(dev);
1142 }
1143 }
1144 }
1145
1146 /* switch to new settings */
1147 so->ifindex = ifindex;
1148 so->rxid = addr->can_addr.tp.rx_id;
1149 so->txid = addr->can_addr.tp.tx_id;
1150 so->bound = 1;
1151
1152 out:
1153 release_sock(sk);
1154
1155 if (notify_enetdown) {
1156 sk->sk_err = ENETDOWN;
1157 if (!sock_flag(sk, SOCK_DEAD))
1158 sk->sk_error_report(sk);
1159 }
1160
1161 return err;
1162 }
1163
isotp_getname(struct socket * sock,struct sockaddr * uaddr,int peer)1164 static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1165 {
1166 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1167 struct sock *sk = sock->sk;
1168 struct isotp_sock *so = isotp_sk(sk);
1169
1170 if (peer)
1171 return -EOPNOTSUPP;
1172
1173 memset(addr, 0, ISOTP_MIN_NAMELEN);
1174 addr->can_family = AF_CAN;
1175 addr->can_ifindex = so->ifindex;
1176 addr->can_addr.tp.rx_id = so->rxid;
1177 addr->can_addr.tp.tx_id = so->txid;
1178
1179 return ISOTP_MIN_NAMELEN;
1180 }
1181
isotp_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1182 static int isotp_setsockopt(struct socket *sock, int level, int optname,
1183 sockptr_t optval, unsigned int optlen)
1184 {
1185 struct sock *sk = sock->sk;
1186 struct isotp_sock *so = isotp_sk(sk);
1187 int ret = 0;
1188
1189 if (level != SOL_CAN_ISOTP)
1190 return -EINVAL;
1191
1192 if (so->bound)
1193 return -EISCONN;
1194
1195 switch (optname) {
1196 case CAN_ISOTP_OPTS:
1197 if (optlen != sizeof(struct can_isotp_options))
1198 return -EINVAL;
1199
1200 if (copy_from_sockptr(&so->opt, optval, optlen))
1201 return -EFAULT;
1202
1203 /* no separate rx_ext_address is given => use ext_address */
1204 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1205 so->opt.rx_ext_address = so->opt.ext_address;
1206 break;
1207
1208 case CAN_ISOTP_RECV_FC:
1209 if (optlen != sizeof(struct can_isotp_fc_options))
1210 return -EINVAL;
1211
1212 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1213 return -EFAULT;
1214 break;
1215
1216 case CAN_ISOTP_TX_STMIN:
1217 if (optlen != sizeof(u32))
1218 return -EINVAL;
1219
1220 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1221 return -EFAULT;
1222 break;
1223
1224 case CAN_ISOTP_RX_STMIN:
1225 if (optlen != sizeof(u32))
1226 return -EINVAL;
1227
1228 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1229 return -EFAULT;
1230 break;
1231
1232 case CAN_ISOTP_LL_OPTS:
1233 if (optlen == sizeof(struct can_isotp_ll_options)) {
1234 struct can_isotp_ll_options ll;
1235
1236 if (copy_from_sockptr(&ll, optval, optlen))
1237 return -EFAULT;
1238
1239 /* check for correct ISO 11898-1 DLC data length */
1240 if (ll.tx_dl != padlen(ll.tx_dl))
1241 return -EINVAL;
1242
1243 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1244 return -EINVAL;
1245
1246 if (ll.mtu == CAN_MTU &&
1247 (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1248 return -EINVAL;
1249
1250 memcpy(&so->ll, &ll, sizeof(ll));
1251
1252 /* set ll_dl for tx path to similar place as for rx */
1253 so->tx.ll_dl = ll.tx_dl;
1254 } else {
1255 return -EINVAL;
1256 }
1257 break;
1258
1259 default:
1260 ret = -ENOPROTOOPT;
1261 }
1262
1263 return ret;
1264 }
1265
isotp_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)1266 static int isotp_getsockopt(struct socket *sock, int level, int optname,
1267 char __user *optval, int __user *optlen)
1268 {
1269 struct sock *sk = sock->sk;
1270 struct isotp_sock *so = isotp_sk(sk);
1271 int len;
1272 void *val;
1273
1274 if (level != SOL_CAN_ISOTP)
1275 return -EINVAL;
1276 if (get_user(len, optlen))
1277 return -EFAULT;
1278 if (len < 0)
1279 return -EINVAL;
1280
1281 switch (optname) {
1282 case CAN_ISOTP_OPTS:
1283 len = min_t(int, len, sizeof(struct can_isotp_options));
1284 val = &so->opt;
1285 break;
1286
1287 case CAN_ISOTP_RECV_FC:
1288 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1289 val = &so->rxfc;
1290 break;
1291
1292 case CAN_ISOTP_TX_STMIN:
1293 len = min_t(int, len, sizeof(u32));
1294 val = &so->force_tx_stmin;
1295 break;
1296
1297 case CAN_ISOTP_RX_STMIN:
1298 len = min_t(int, len, sizeof(u32));
1299 val = &so->force_rx_stmin;
1300 break;
1301
1302 case CAN_ISOTP_LL_OPTS:
1303 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1304 val = &so->ll;
1305 break;
1306
1307 default:
1308 return -ENOPROTOOPT;
1309 }
1310
1311 if (put_user(len, optlen))
1312 return -EFAULT;
1313 if (copy_to_user(optval, val, len))
1314 return -EFAULT;
1315 return 0;
1316 }
1317
isotp_notify(struct isotp_sock * so,unsigned long msg,struct net_device * dev)1318 static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1319 struct net_device *dev)
1320 {
1321 struct sock *sk = &so->sk;
1322
1323 if (!net_eq(dev_net(dev), sock_net(sk)))
1324 return;
1325
1326 if (so->ifindex != dev->ifindex)
1327 return;
1328
1329 switch (msg) {
1330 case NETDEV_UNREGISTER:
1331 lock_sock(sk);
1332 /* remove current filters & unregister */
1333 if (so->bound)
1334 can_rx_unregister(dev_net(dev), dev, so->rxid,
1335 SINGLE_MASK(so->rxid),
1336 isotp_rcv, sk);
1337
1338 so->ifindex = 0;
1339 so->bound = 0;
1340 release_sock(sk);
1341
1342 sk->sk_err = ENODEV;
1343 if (!sock_flag(sk, SOCK_DEAD))
1344 sk->sk_error_report(sk);
1345 break;
1346
1347 case NETDEV_DOWN:
1348 sk->sk_err = ENETDOWN;
1349 if (!sock_flag(sk, SOCK_DEAD))
1350 sk->sk_error_report(sk);
1351 break;
1352 }
1353 }
1354
isotp_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)1355 static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1356 void *ptr)
1357 {
1358 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1359
1360 if (dev->type != ARPHRD_CAN)
1361 return NOTIFY_DONE;
1362 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1363 return NOTIFY_DONE;
1364 if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1365 return NOTIFY_DONE;
1366
1367 spin_lock(&isotp_notifier_lock);
1368 list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1369 spin_unlock(&isotp_notifier_lock);
1370 isotp_notify(isotp_busy_notifier, msg, dev);
1371 spin_lock(&isotp_notifier_lock);
1372 }
1373 isotp_busy_notifier = NULL;
1374 spin_unlock(&isotp_notifier_lock);
1375 return NOTIFY_DONE;
1376 }
1377
isotp_init(struct sock * sk)1378 static int isotp_init(struct sock *sk)
1379 {
1380 struct isotp_sock *so = isotp_sk(sk);
1381
1382 so->ifindex = 0;
1383 so->bound = 0;
1384
1385 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1386 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1387 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1388 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1389 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1390 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1391 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1392 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1393 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1394 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1395 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1396 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1397
1398 /* set ll_dl for tx path to similar place as for rx */
1399 so->tx.ll_dl = so->ll.tx_dl;
1400
1401 so->rx.state = ISOTP_IDLE;
1402 so->tx.state = ISOTP_IDLE;
1403
1404 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1405 so->rxtimer.function = isotp_rx_timer_handler;
1406 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1407 so->txtimer.function = isotp_tx_timer_handler;
1408
1409 init_waitqueue_head(&so->wait);
1410
1411 spin_lock(&isotp_notifier_lock);
1412 list_add_tail(&so->notifier, &isotp_notifier_list);
1413 spin_unlock(&isotp_notifier_lock);
1414
1415 return 0;
1416 }
1417
isotp_sock_no_ioctlcmd(struct socket * sock,unsigned int cmd,unsigned long arg)1418 static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1419 unsigned long arg)
1420 {
1421 /* no ioctls for socket layer -> hand it down to NIC layer */
1422 return -ENOIOCTLCMD;
1423 }
1424
1425 static const struct proto_ops isotp_ops = {
1426 .family = PF_CAN,
1427 .release = isotp_release,
1428 .bind = isotp_bind,
1429 .connect = sock_no_connect,
1430 .socketpair = sock_no_socketpair,
1431 .accept = sock_no_accept,
1432 .getname = isotp_getname,
1433 .poll = datagram_poll,
1434 .ioctl = isotp_sock_no_ioctlcmd,
1435 .gettstamp = sock_gettstamp,
1436 .listen = sock_no_listen,
1437 .shutdown = sock_no_shutdown,
1438 .setsockopt = isotp_setsockopt,
1439 .getsockopt = isotp_getsockopt,
1440 .sendmsg = isotp_sendmsg,
1441 .recvmsg = isotp_recvmsg,
1442 .mmap = sock_no_mmap,
1443 .sendpage = sock_no_sendpage,
1444 };
1445
1446 static struct proto isotp_proto __read_mostly = {
1447 .name = "CAN_ISOTP",
1448 .owner = THIS_MODULE,
1449 .obj_size = sizeof(struct isotp_sock),
1450 .init = isotp_init,
1451 };
1452
1453 static const struct can_proto isotp_can_proto = {
1454 .type = SOCK_DGRAM,
1455 .protocol = CAN_ISOTP,
1456 .ops = &isotp_ops,
1457 .prot = &isotp_proto,
1458 };
1459
1460 static struct notifier_block canisotp_notifier = {
1461 .notifier_call = isotp_notifier
1462 };
1463
isotp_module_init(void)1464 static __init int isotp_module_init(void)
1465 {
1466 int err;
1467
1468 pr_info("can: isotp protocol\n");
1469
1470 err = can_proto_register(&isotp_can_proto);
1471 if (err < 0)
1472 pr_err("can: registration of isotp protocol failed\n");
1473 else
1474 register_netdevice_notifier(&canisotp_notifier);
1475
1476 return err;
1477 }
1478
isotp_module_exit(void)1479 static __exit void isotp_module_exit(void)
1480 {
1481 can_proto_unregister(&isotp_can_proto);
1482 unregister_netdevice_notifier(&canisotp_notifier);
1483 }
1484
1485 module_init(isotp_module_init);
1486 module_exit(isotp_module_exit);
1487