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1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2/* isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
3 *
4 * This implementation does not provide ISO-TP specific return values to the
5 * userspace.
6 *
7 * - RX path timeout of data reception leads to -ETIMEDOUT
8 * - RX path SN mismatch leads to -EILSEQ
9 * - RX path data reception with wrong padding leads to -EBADMSG
10 * - TX path flowcontrol reception timeout leads to -ECOMM
11 * - TX path flowcontrol reception overflow leads to -EMSGSIZE
12 * - TX path flowcontrol reception with wrong layout/padding leads to -EBADMSG
13 * - when a transfer (tx) is on the run the next write() blocks until it's done
14 * - use CAN_ISOTP_WAIT_TX_DONE flag to block the caller until the PDU is sent
15 * - as we have static buffers the check whether the PDU fits into the buffer
16 * is done at FF reception time (no support for sending 'wait frames')
17 *
18 * Copyright (c) 2020 Volkswagen Group Electronic Research
19 * All rights reserved.
20 *
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
23 * are met:
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
29 * 3. Neither the name of Volkswagen nor the names of its contributors
30 * may be used to endorse or promote products derived from this software
31 * without specific prior written permission.
32 *
33 * Alternatively, provided that this notice is retained in full, this
34 * software may be distributed under the terms of the GNU General
35 * Public License ("GPL") version 2, in which case the provisions of the
36 * GPL apply INSTEAD OF those given above.
37 *
38 * The provided data structures and external interfaces from this code
39 * are not restricted to be used by modules with a GPL compatible license.
40 *
41 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
42 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
43 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
44 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
45 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
48 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
49 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
50 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
51 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
52 * DAMAGE.
53 */
54
55#include <linux/module.h>
56#include <linux/init.h>
57#include <linux/interrupt.h>
58#include <linux/spinlock.h>
59#include <linux/hrtimer.h>
60#include <linux/wait.h>
61#include <linux/uio.h>
62#include <linux/net.h>
63#include <linux/netdevice.h>
64#include <linux/socket.h>
65#include <linux/if_arp.h>
66#include <linux/skbuff.h>
67#include <linux/can.h>
68#include <linux/can/core.h>
69#include <linux/can/skb.h>
70#include <linux/can/isotp.h>
71#include <linux/slab.h>
72#include <net/sock.h>
73#include <net/net_namespace.h>
74
75MODULE_DESCRIPTION("PF_CAN ISO 15765-2 transport protocol");
76MODULE_LICENSE("Dual BSD/GPL");
77MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
78MODULE_ALIAS("can-proto-6");
79
80#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
81
82#define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
83 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
84 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
85
86/* Since ISO 15765-2:2016 the CAN isotp protocol supports more than 4095
87 * byte per ISO PDU as the FF_DL can take full 32 bit values (4 Gbyte).
88 * We would need some good concept to handle this between user space and
89 * kernel space. For now set the static buffer to something about 8 kbyte
90 * to be able to test this new functionality.
91 */
92#define DEFAULT_MAX_PDU_SIZE 8300
93
94/* maximum PDU size before ISO 15765-2:2016 extension was 4095 */
95#define MAX_12BIT_PDU_SIZE 4095
96
97/* limit the isotp pdu size from the optional module parameter to 1MByte */
98#define MAX_PDU_SIZE (1025 * 1024U)
99
100static unsigned int max_pdu_size __read_mostly = DEFAULT_MAX_PDU_SIZE;
101module_param(max_pdu_size, uint, 0444);
102MODULE_PARM_DESC(max_pdu_size, "maximum isotp pdu size (default "
103 __stringify(DEFAULT_MAX_PDU_SIZE) ")");
104
105/* N_PCI type values in bits 7-4 of N_PCI bytes */
106#define N_PCI_SF 0x00 /* single frame */
107#define N_PCI_FF 0x10 /* first frame */
108#define N_PCI_CF 0x20 /* consecutive frame */
109#define N_PCI_FC 0x30 /* flow control */
110
111#define N_PCI_SZ 1 /* size of the PCI byte #1 */
112#define SF_PCI_SZ4 1 /* size of SingleFrame PCI including 4 bit SF_DL */
113#define SF_PCI_SZ8 2 /* size of SingleFrame PCI including 8 bit SF_DL */
114#define FF_PCI_SZ12 2 /* size of FirstFrame PCI including 12 bit FF_DL */
115#define FF_PCI_SZ32 6 /* size of FirstFrame PCI including 32 bit FF_DL */
116#define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
117
118#define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
119#define ISOTP_ALL_BC_FLAGS (CAN_ISOTP_SF_BROADCAST | CAN_ISOTP_CF_BROADCAST)
120
121/* Flow Status given in FC frame */
122#define ISOTP_FC_CTS 0 /* clear to send */
123#define ISOTP_FC_WT 1 /* wait */
124#define ISOTP_FC_OVFLW 2 /* overflow */
125
126#define ISOTP_FC_TIMEOUT 1 /* 1 sec */
127#define ISOTP_ECHO_TIMEOUT 2 /* 2 secs */
128
129enum {
130 ISOTP_IDLE = 0,
131 ISOTP_WAIT_FIRST_FC,
132 ISOTP_WAIT_FC,
133 ISOTP_WAIT_DATA,
134 ISOTP_SENDING,
135 ISOTP_SHUTDOWN,
136};
137
138struct tpcon {
139 u8 *buf;
140 unsigned int buflen;
141 unsigned int len;
142 unsigned int idx;
143 u32 state;
144 u8 bs;
145 u8 sn;
146 u8 ll_dl;
147 u8 sbuf[DEFAULT_MAX_PDU_SIZE];
148};
149
150struct isotp_sock {
151 struct sock sk;
152 int bound;
153 int ifindex;
154 canid_t txid;
155 canid_t rxid;
156 ktime_t tx_gap;
157 ktime_t lastrxcf_tstamp;
158 struct hrtimer rxtimer, txtimer, txfrtimer;
159 struct can_isotp_options opt;
160 struct can_isotp_fc_options rxfc, txfc;
161 struct can_isotp_ll_options ll;
162 u32 frame_txtime;
163 u32 force_tx_stmin;
164 u32 force_rx_stmin;
165 u32 cfecho; /* consecutive frame echo tag */
166 struct tpcon rx, tx;
167 struct list_head notifier;
168 wait_queue_head_t wait;
169 spinlock_t rx_lock; /* protect single thread state machine */
170};
171
172static LIST_HEAD(isotp_notifier_list);
173static DEFINE_SPINLOCK(isotp_notifier_lock);
174static struct isotp_sock *isotp_busy_notifier;
175
176static inline struct isotp_sock *isotp_sk(const struct sock *sk)
177{
178 return (struct isotp_sock *)sk;
179}
180
181static u32 isotp_bc_flags(struct isotp_sock *so)
182{
183 return so->opt.flags & ISOTP_ALL_BC_FLAGS;
184}
185
186static bool isotp_register_rxid(struct isotp_sock *so)
187{
188 /* no broadcast modes => register rx_id for FC frame reception */
189 return (isotp_bc_flags(so) == 0);
190}
191
192static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
193{
194 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
195 rxtimer);
196 struct sock *sk = &so->sk;
197
198 if (so->rx.state == ISOTP_WAIT_DATA) {
199 /* we did not get new data frames in time */
200
201 /* report 'connection timed out' */
202 sk->sk_err = ETIMEDOUT;
203 if (!sock_flag(sk, SOCK_DEAD))
204 sk_error_report(sk);
205
206 /* reset rx state */
207 so->rx.state = ISOTP_IDLE;
208 }
209
210 return HRTIMER_NORESTART;
211}
212
213static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
214{
215 struct net_device *dev;
216 struct sk_buff *nskb;
217 struct canfd_frame *ncf;
218 struct isotp_sock *so = isotp_sk(sk);
219 int can_send_ret;
220
221 nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
222 if (!nskb)
223 return 1;
224
225 dev = dev_get_by_index(sock_net(sk), so->ifindex);
226 if (!dev) {
227 kfree_skb(nskb);
228 return 1;
229 }
230
231 can_skb_reserve(nskb);
232 can_skb_prv(nskb)->ifindex = dev->ifindex;
233 can_skb_prv(nskb)->skbcnt = 0;
234
235 nskb->dev = dev;
236 can_skb_set_owner(nskb, sk);
237 ncf = (struct canfd_frame *)nskb->data;
238 skb_put_zero(nskb, so->ll.mtu);
239
240 /* create & send flow control reply */
241 ncf->can_id = so->txid;
242
243 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
244 memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
245 ncf->len = CAN_MAX_DLEN;
246 } else {
247 ncf->len = ae + FC_CONTENT_SZ;
248 }
249
250 ncf->data[ae] = N_PCI_FC | flowstatus;
251 ncf->data[ae + 1] = so->rxfc.bs;
252 ncf->data[ae + 2] = so->rxfc.stmin;
253
254 if (ae)
255 ncf->data[0] = so->opt.ext_address;
256
257 ncf->flags = so->ll.tx_flags;
258
259 can_send_ret = can_send(nskb, 1);
260 if (can_send_ret)
261 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
262 __func__, ERR_PTR(can_send_ret));
263
264 dev_put(dev);
265
266 /* reset blocksize counter */
267 so->rx.bs = 0;
268
269 /* reset last CF frame rx timestamp for rx stmin enforcement */
270 so->lastrxcf_tstamp = ktime_set(0, 0);
271
272 /* start rx timeout watchdog */
273 hrtimer_start(&so->rxtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
274 HRTIMER_MODE_REL_SOFT);
275 return 0;
276}
277
278static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
279{
280 struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
281
282 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
283
284 memset(addr, 0, sizeof(*addr));
285 addr->can_family = AF_CAN;
286 addr->can_ifindex = skb->dev->ifindex;
287
288 if (sock_queue_rcv_skb(sk, skb) < 0)
289 kfree_skb(skb);
290}
291
292static u8 padlen(u8 datalen)
293{
294 static const u8 plen[] = {
295 8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
296 12, 12, 12, 12, /* 9 - 12 */
297 16, 16, 16, 16, /* 13 - 16 */
298 20, 20, 20, 20, /* 17 - 20 */
299 24, 24, 24, 24, /* 21 - 24 */
300 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
301 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
302 48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
303 };
304
305 if (datalen > 48)
306 return 64;
307
308 return plen[datalen];
309}
310
311/* check for length optimization and return 1/true when the check fails */
312static int check_optimized(struct canfd_frame *cf, int start_index)
313{
314 /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
315 * padding would start at this point. E.g. if the padding would
316 * start at cf.data[7] cf->len has to be 7 to be optimal.
317 * Note: The data[] index starts with zero.
318 */
319 if (cf->len <= CAN_MAX_DLEN)
320 return (cf->len != start_index);
321
322 /* This relation is also valid in the non-linear DLC range, where
323 * we need to take care of the minimal next possible CAN_DL.
324 * The correct check would be (padlen(cf->len) != padlen(start_index)).
325 * But as cf->len can only take discrete values from 12, .., 64 at this
326 * point the padlen(cf->len) is always equal to cf->len.
327 */
328 return (cf->len != padlen(start_index));
329}
330
331/* check padding and return 1/true when the check fails */
332static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
333 int start_index, u8 content)
334{
335 int i;
336
337 /* no RX_PADDING value => check length of optimized frame length */
338 if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
339 if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
340 return check_optimized(cf, start_index);
341
342 /* no valid test against empty value => ignore frame */
343 return 1;
344 }
345
346 /* check datalength of correctly padded CAN frame */
347 if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
348 cf->len != padlen(cf->len))
349 return 1;
350
351 /* check padding content */
352 if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
353 for (i = start_index; i < cf->len; i++)
354 if (cf->data[i] != content)
355 return 1;
356 }
357 return 0;
358}
359
360static void isotp_send_cframe(struct isotp_sock *so);
361
362static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
363{
364 struct sock *sk = &so->sk;
365
366 if (so->tx.state != ISOTP_WAIT_FC &&
367 so->tx.state != ISOTP_WAIT_FIRST_FC)
368 return 0;
369
370 hrtimer_cancel(&so->txtimer);
371
372 if ((cf->len < ae + FC_CONTENT_SZ) ||
373 ((so->opt.flags & ISOTP_CHECK_PADDING) &&
374 check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
375 /* malformed PDU - report 'not a data message' */
376 sk->sk_err = EBADMSG;
377 if (!sock_flag(sk, SOCK_DEAD))
378 sk_error_report(sk);
379
380 so->tx.state = ISOTP_IDLE;
381 wake_up_interruptible(&so->wait);
382 return 1;
383 }
384
385 /* get static/dynamic communication params from first/every FC frame */
386 if (so->tx.state == ISOTP_WAIT_FIRST_FC ||
387 so->opt.flags & CAN_ISOTP_DYN_FC_PARMS) {
388 so->txfc.bs = cf->data[ae + 1];
389 so->txfc.stmin = cf->data[ae + 2];
390
391 /* fix wrong STmin values according spec */
392 if (so->txfc.stmin > 0x7F &&
393 (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
394 so->txfc.stmin = 0x7F;
395
396 so->tx_gap = ktime_set(0, 0);
397 /* add transmission time for CAN frame N_As */
398 so->tx_gap = ktime_add_ns(so->tx_gap, so->frame_txtime);
399 /* add waiting time for consecutive frames N_Cs */
400 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
401 so->tx_gap = ktime_add_ns(so->tx_gap,
402 so->force_tx_stmin);
403 else if (so->txfc.stmin < 0x80)
404 so->tx_gap = ktime_add_ns(so->tx_gap,
405 so->txfc.stmin * 1000000);
406 else
407 so->tx_gap = ktime_add_ns(so->tx_gap,
408 (so->txfc.stmin - 0xF0)
409 * 100000);
410 so->tx.state = ISOTP_WAIT_FC;
411 }
412
413 switch (cf->data[ae] & 0x0F) {
414 case ISOTP_FC_CTS:
415 so->tx.bs = 0;
416 so->tx.state = ISOTP_SENDING;
417 /* send CF frame and enable echo timeout handling */
418 hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
419 HRTIMER_MODE_REL_SOFT);
420 isotp_send_cframe(so);
421 break;
422
423 case ISOTP_FC_WT:
424 /* start timer to wait for next FC frame */
425 hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
426 HRTIMER_MODE_REL_SOFT);
427 break;
428
429 case ISOTP_FC_OVFLW:
430 /* overflow on receiver side - report 'message too long' */
431 sk->sk_err = EMSGSIZE;
432 if (!sock_flag(sk, SOCK_DEAD))
433 sk_error_report(sk);
434 fallthrough;
435
436 default:
437 /* stop this tx job */
438 so->tx.state = ISOTP_IDLE;
439 wake_up_interruptible(&so->wait);
440 }
441 return 0;
442}
443
444static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
445 struct sk_buff *skb, int len)
446{
447 struct isotp_sock *so = isotp_sk(sk);
448 struct sk_buff *nskb;
449
450 hrtimer_cancel(&so->rxtimer);
451 so->rx.state = ISOTP_IDLE;
452
453 if (!len || len > cf->len - pcilen)
454 return 1;
455
456 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
457 check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
458 /* malformed PDU - report 'not a data message' */
459 sk->sk_err = EBADMSG;
460 if (!sock_flag(sk, SOCK_DEAD))
461 sk_error_report(sk);
462 return 1;
463 }
464
465 nskb = alloc_skb(len, gfp_any());
466 if (!nskb)
467 return 1;
468
469 memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
470
471 nskb->tstamp = skb->tstamp;
472 nskb->dev = skb->dev;
473 isotp_rcv_skb(nskb, sk);
474 return 0;
475}
476
477static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
478{
479 struct isotp_sock *so = isotp_sk(sk);
480 int i;
481 int off;
482 int ff_pci_sz;
483
484 hrtimer_cancel(&so->rxtimer);
485 so->rx.state = ISOTP_IDLE;
486
487 /* get the used sender LL_DL from the (first) CAN frame data length */
488 so->rx.ll_dl = padlen(cf->len);
489
490 /* the first frame has to use the entire frame up to LL_DL length */
491 if (cf->len != so->rx.ll_dl)
492 return 1;
493
494 /* get the FF_DL */
495 so->rx.len = (cf->data[ae] & 0x0F) << 8;
496 so->rx.len += cf->data[ae + 1];
497
498 /* Check for FF_DL escape sequence supporting 32 bit PDU length */
499 if (so->rx.len) {
500 ff_pci_sz = FF_PCI_SZ12;
501 } else {
502 /* FF_DL = 0 => get real length from next 4 bytes */
503 so->rx.len = cf->data[ae + 2] << 24;
504 so->rx.len += cf->data[ae + 3] << 16;
505 so->rx.len += cf->data[ae + 4] << 8;
506 so->rx.len += cf->data[ae + 5];
507 ff_pci_sz = FF_PCI_SZ32;
508 }
509
510 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
511 off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
512
513 if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
514 return 1;
515
516 /* PDU size > default => try max_pdu_size */
517 if (so->rx.len > so->rx.buflen && so->rx.buflen < max_pdu_size) {
518 u8 *newbuf = kmalloc(max_pdu_size, GFP_ATOMIC);
519
520 if (newbuf) {
521 so->rx.buf = newbuf;
522 so->rx.buflen = max_pdu_size;
523 }
524 }
525
526 if (so->rx.len > so->rx.buflen) {
527 /* send FC frame with overflow status */
528 isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
529 return 1;
530 }
531
532 /* copy the first received data bytes */
533 so->rx.idx = 0;
534 for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
535 so->rx.buf[so->rx.idx++] = cf->data[i];
536
537 /* initial setup for this pdu reception */
538 so->rx.sn = 1;
539 so->rx.state = ISOTP_WAIT_DATA;
540
541 /* no creation of flow control frames */
542 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
543 return 0;
544
545 /* send our first FC frame */
546 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
547 return 0;
548}
549
550static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
551 struct sk_buff *skb)
552{
553 struct isotp_sock *so = isotp_sk(sk);
554 struct sk_buff *nskb;
555 int i;
556
557 if (so->rx.state != ISOTP_WAIT_DATA)
558 return 0;
559
560 /* drop if timestamp gap is less than force_rx_stmin nano secs */
561 if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
562 if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
563 so->force_rx_stmin)
564 return 0;
565
566 so->lastrxcf_tstamp = skb->tstamp;
567 }
568
569 hrtimer_cancel(&so->rxtimer);
570
571 /* CFs are never longer than the FF */
572 if (cf->len > so->rx.ll_dl)
573 return 1;
574
575 /* CFs have usually the LL_DL length */
576 if (cf->len < so->rx.ll_dl) {
577 /* this is only allowed for the last CF */
578 if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
579 return 1;
580 }
581
582 if ((cf->data[ae] & 0x0F) != so->rx.sn) {
583 /* wrong sn detected - report 'illegal byte sequence' */
584 sk->sk_err = EILSEQ;
585 if (!sock_flag(sk, SOCK_DEAD))
586 sk_error_report(sk);
587
588 /* reset rx state */
589 so->rx.state = ISOTP_IDLE;
590 return 1;
591 }
592 so->rx.sn++;
593 so->rx.sn %= 16;
594
595 for (i = ae + N_PCI_SZ; i < cf->len; i++) {
596 so->rx.buf[so->rx.idx++] = cf->data[i];
597 if (so->rx.idx >= so->rx.len)
598 break;
599 }
600
601 if (so->rx.idx >= so->rx.len) {
602 /* we are done */
603 so->rx.state = ISOTP_IDLE;
604
605 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
606 check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
607 /* malformed PDU - report 'not a data message' */
608 sk->sk_err = EBADMSG;
609 if (!sock_flag(sk, SOCK_DEAD))
610 sk_error_report(sk);
611 return 1;
612 }
613
614 nskb = alloc_skb(so->rx.len, gfp_any());
615 if (!nskb)
616 return 1;
617
618 memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
619 so->rx.len);
620
621 nskb->tstamp = skb->tstamp;
622 nskb->dev = skb->dev;
623 isotp_rcv_skb(nskb, sk);
624 return 0;
625 }
626
627 /* perform blocksize handling, if enabled */
628 if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
629 /* start rx timeout watchdog */
630 hrtimer_start(&so->rxtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
631 HRTIMER_MODE_REL_SOFT);
632 return 0;
633 }
634
635 /* no creation of flow control frames */
636 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
637 return 0;
638
639 /* we reached the specified blocksize so->rxfc.bs */
640 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
641 return 0;
642}
643
644static void isotp_rcv(struct sk_buff *skb, void *data)
645{
646 struct sock *sk = (struct sock *)data;
647 struct isotp_sock *so = isotp_sk(sk);
648 struct canfd_frame *cf;
649 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
650 u8 n_pci_type, sf_dl;
651
652 /* Strictly receive only frames with the configured MTU size
653 * => clear separation of CAN2.0 / CAN FD transport channels
654 */
655 if (skb->len != so->ll.mtu)
656 return;
657
658 cf = (struct canfd_frame *)skb->data;
659
660 /* if enabled: check reception of my configured extended address */
661 if (ae && cf->data[0] != so->opt.rx_ext_address)
662 return;
663
664 n_pci_type = cf->data[ae] & 0xF0;
665
666 /* Make sure the state changes and data structures stay consistent at
667 * CAN frame reception time. This locking is not needed in real world
668 * use cases but the inconsistency can be triggered with syzkaller.
669 */
670 spin_lock(&so->rx_lock);
671
672 if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
673 /* check rx/tx path half duplex expectations */
674 if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
675 (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
676 goto out_unlock;
677 }
678
679 switch (n_pci_type) {
680 case N_PCI_FC:
681 /* tx path: flow control frame containing the FC parameters */
682 isotp_rcv_fc(so, cf, ae);
683 break;
684
685 case N_PCI_SF:
686 /* rx path: single frame
687 *
688 * As we do not have a rx.ll_dl configuration, we can only test
689 * if the CAN frames payload length matches the LL_DL == 8
690 * requirements - no matter if it's CAN 2.0 or CAN FD
691 */
692
693 /* get the SF_DL from the N_PCI byte */
694 sf_dl = cf->data[ae] & 0x0F;
695
696 if (cf->len <= CAN_MAX_DLEN) {
697 isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
698 } else {
699 if (can_is_canfd_skb(skb)) {
700 /* We have a CAN FD frame and CAN_DL is greater than 8:
701 * Only frames with the SF_DL == 0 ESC value are valid.
702 *
703 * If so take care of the increased SF PCI size
704 * (SF_PCI_SZ8) to point to the message content behind
705 * the extended SF PCI info and get the real SF_DL
706 * length value from the formerly first data byte.
707 */
708 if (sf_dl == 0)
709 isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
710 cf->data[SF_PCI_SZ4 + ae]);
711 }
712 }
713 break;
714
715 case N_PCI_FF:
716 /* rx path: first frame */
717 isotp_rcv_ff(sk, cf, ae);
718 break;
719
720 case N_PCI_CF:
721 /* rx path: consecutive frame */
722 isotp_rcv_cf(sk, cf, ae, skb);
723 break;
724 }
725
726out_unlock:
727 spin_unlock(&so->rx_lock);
728}
729
730static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
731 int ae, int off)
732{
733 int pcilen = N_PCI_SZ + ae + off;
734 int space = so->tx.ll_dl - pcilen;
735 int num = min_t(int, so->tx.len - so->tx.idx, space);
736 int i;
737
738 cf->can_id = so->txid;
739 cf->len = num + pcilen;
740
741 if (num < space) {
742 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
743 /* user requested padding */
744 cf->len = padlen(cf->len);
745 memset(cf->data, so->opt.txpad_content, cf->len);
746 } else if (cf->len > CAN_MAX_DLEN) {
747 /* mandatory padding for CAN FD frames */
748 cf->len = padlen(cf->len);
749 memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
750 cf->len);
751 }
752 }
753
754 for (i = 0; i < num; i++)
755 cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
756
757 if (ae)
758 cf->data[0] = so->opt.ext_address;
759}
760
761static void isotp_send_cframe(struct isotp_sock *so)
762{
763 struct sock *sk = &so->sk;
764 struct sk_buff *skb;
765 struct net_device *dev;
766 struct canfd_frame *cf;
767 int can_send_ret;
768 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
769
770 dev = dev_get_by_index(sock_net(sk), so->ifindex);
771 if (!dev)
772 return;
773
774 skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), GFP_ATOMIC);
775 if (!skb) {
776 dev_put(dev);
777 return;
778 }
779
780 can_skb_reserve(skb);
781 can_skb_prv(skb)->ifindex = dev->ifindex;
782 can_skb_prv(skb)->skbcnt = 0;
783
784 cf = (struct canfd_frame *)skb->data;
785 skb_put_zero(skb, so->ll.mtu);
786
787 /* create consecutive frame */
788 isotp_fill_dataframe(cf, so, ae, 0);
789
790 /* place consecutive frame N_PCI in appropriate index */
791 cf->data[ae] = N_PCI_CF | so->tx.sn++;
792 so->tx.sn %= 16;
793 so->tx.bs++;
794
795 cf->flags = so->ll.tx_flags;
796
797 skb->dev = dev;
798 can_skb_set_owner(skb, sk);
799
800 /* cfecho should have been zero'ed by init/isotp_rcv_echo() */
801 if (so->cfecho)
802 pr_notice_once("can-isotp: cfecho is %08X != 0\n", so->cfecho);
803
804 /* set consecutive frame echo tag */
805 so->cfecho = *(u32 *)cf->data;
806
807 /* send frame with local echo enabled */
808 can_send_ret = can_send(skb, 1);
809 if (can_send_ret) {
810 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
811 __func__, ERR_PTR(can_send_ret));
812 if (can_send_ret == -ENOBUFS)
813 pr_notice_once("can-isotp: tx queue is full\n");
814 }
815 dev_put(dev);
816}
817
818static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
819 int ae)
820{
821 int i;
822 int ff_pci_sz;
823
824 cf->can_id = so->txid;
825 cf->len = so->tx.ll_dl;
826 if (ae)
827 cf->data[0] = so->opt.ext_address;
828
829 /* create N_PCI bytes with 12/32 bit FF_DL data length */
830 if (so->tx.len > MAX_12BIT_PDU_SIZE) {
831 /* use 32 bit FF_DL notation */
832 cf->data[ae] = N_PCI_FF;
833 cf->data[ae + 1] = 0;
834 cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
835 cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
836 cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
837 cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
838 ff_pci_sz = FF_PCI_SZ32;
839 } else {
840 /* use 12 bit FF_DL notation */
841 cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
842 cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
843 ff_pci_sz = FF_PCI_SZ12;
844 }
845
846 /* add first data bytes depending on ae */
847 for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
848 cf->data[i] = so->tx.buf[so->tx.idx++];
849
850 so->tx.sn = 1;
851}
852
853static void isotp_rcv_echo(struct sk_buff *skb, void *data)
854{
855 struct sock *sk = (struct sock *)data;
856 struct isotp_sock *so = isotp_sk(sk);
857 struct canfd_frame *cf = (struct canfd_frame *)skb->data;
858
859 /* only handle my own local echo CF/SF skb's (no FF!) */
860 if (skb->sk != sk || so->cfecho != *(u32 *)cf->data)
861 return;
862
863 /* cancel local echo timeout */
864 hrtimer_cancel(&so->txtimer);
865
866 /* local echo skb with consecutive frame has been consumed */
867 so->cfecho = 0;
868
869 if (so->tx.idx >= so->tx.len) {
870 /* we are done */
871 so->tx.state = ISOTP_IDLE;
872 wake_up_interruptible(&so->wait);
873 return;
874 }
875
876 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
877 /* stop and wait for FC with timeout */
878 so->tx.state = ISOTP_WAIT_FC;
879 hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
880 HRTIMER_MODE_REL_SOFT);
881 return;
882 }
883
884 /* no gap between data frames needed => use burst mode */
885 if (!so->tx_gap) {
886 /* enable echo timeout handling */
887 hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
888 HRTIMER_MODE_REL_SOFT);
889 isotp_send_cframe(so);
890 return;
891 }
892
893 /* start timer to send next consecutive frame with correct delay */
894 hrtimer_start(&so->txfrtimer, so->tx_gap, HRTIMER_MODE_REL_SOFT);
895}
896
897static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
898{
899 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
900 txtimer);
901 struct sock *sk = &so->sk;
902
903 /* don't handle timeouts in IDLE or SHUTDOWN state */
904 if (so->tx.state == ISOTP_IDLE || so->tx.state == ISOTP_SHUTDOWN)
905 return HRTIMER_NORESTART;
906
907 /* we did not get any flow control or echo frame in time */
908
909 /* report 'communication error on send' */
910 sk->sk_err = ECOMM;
911 if (!sock_flag(sk, SOCK_DEAD))
912 sk_error_report(sk);
913
914 /* reset tx state */
915 so->tx.state = ISOTP_IDLE;
916 wake_up_interruptible(&so->wait);
917
918 return HRTIMER_NORESTART;
919}
920
921static enum hrtimer_restart isotp_txfr_timer_handler(struct hrtimer *hrtimer)
922{
923 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
924 txfrtimer);
925
926 /* start echo timeout handling and cover below protocol error */
927 hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
928 HRTIMER_MODE_REL_SOFT);
929
930 /* cfecho should be consumed by isotp_rcv_echo() here */
931 if (so->tx.state == ISOTP_SENDING && !so->cfecho)
932 isotp_send_cframe(so);
933
934 return HRTIMER_NORESTART;
935}
936
937static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
938{
939 struct sock *sk = sock->sk;
940 struct isotp_sock *so = isotp_sk(sk);
941 struct sk_buff *skb;
942 struct net_device *dev;
943 struct canfd_frame *cf;
944 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
945 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
946 s64 hrtimer_sec = ISOTP_ECHO_TIMEOUT;
947 int off;
948 int err;
949
950 if (!so->bound || so->tx.state == ISOTP_SHUTDOWN)
951 return -EADDRNOTAVAIL;
952
953 while (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE) {
954 /* we do not support multiple buffers - for now */
955 if (msg->msg_flags & MSG_DONTWAIT)
956 return -EAGAIN;
957
958 if (so->tx.state == ISOTP_SHUTDOWN)
959 return -EADDRNOTAVAIL;
960
961 /* wait for complete transmission of current pdu */
962 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
963 if (err)
964 goto err_event_drop;
965 }
966
967 /* PDU size > default => try max_pdu_size */
968 if (size > so->tx.buflen && so->tx.buflen < max_pdu_size) {
969 u8 *newbuf = kmalloc(max_pdu_size, GFP_KERNEL);
970
971 if (newbuf) {
972 so->tx.buf = newbuf;
973 so->tx.buflen = max_pdu_size;
974 }
975 }
976
977 if (!size || size > so->tx.buflen) {
978 err = -EINVAL;
979 goto err_out_drop;
980 }
981
982 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
983 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
984
985 /* does the given data fit into a single frame for SF_BROADCAST? */
986 if ((isotp_bc_flags(so) == CAN_ISOTP_SF_BROADCAST) &&
987 (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
988 err = -EINVAL;
989 goto err_out_drop;
990 }
991
992 err = memcpy_from_msg(so->tx.buf, msg, size);
993 if (err < 0)
994 goto err_out_drop;
995
996 dev = dev_get_by_index(sock_net(sk), so->ifindex);
997 if (!dev) {
998 err = -ENXIO;
999 goto err_out_drop;
1000 }
1001
1002 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
1003 msg->msg_flags & MSG_DONTWAIT, &err);
1004 if (!skb) {
1005 dev_put(dev);
1006 goto err_out_drop;
1007 }
1008
1009 can_skb_reserve(skb);
1010 can_skb_prv(skb)->ifindex = dev->ifindex;
1011 can_skb_prv(skb)->skbcnt = 0;
1012
1013 so->tx.len = size;
1014 so->tx.idx = 0;
1015
1016 cf = (struct canfd_frame *)skb->data;
1017 skb_put_zero(skb, so->ll.mtu);
1018
1019 /* cfecho should have been zero'ed by init / former isotp_rcv_echo() */
1020 if (so->cfecho)
1021 pr_notice_once("can-isotp: uninit cfecho %08X\n", so->cfecho);
1022
1023 /* check for single frame transmission depending on TX_DL */
1024 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
1025 /* The message size generally fits into a SingleFrame - good.
1026 *
1027 * SF_DL ESC offset optimization:
1028 *
1029 * When TX_DL is greater 8 but the message would still fit
1030 * into a 8 byte CAN frame, we can omit the offset.
1031 * This prevents a protocol caused length extension from
1032 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
1033 */
1034 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
1035 off = 0;
1036
1037 isotp_fill_dataframe(cf, so, ae, off);
1038
1039 /* place single frame N_PCI w/o length in appropriate index */
1040 cf->data[ae] = N_PCI_SF;
1041
1042 /* place SF_DL size value depending on the SF_DL ESC offset */
1043 if (off)
1044 cf->data[SF_PCI_SZ4 + ae] = size;
1045 else
1046 cf->data[ae] |= size;
1047
1048 /* set CF echo tag for isotp_rcv_echo() (SF-mode) */
1049 so->cfecho = *(u32 *)cf->data;
1050 } else {
1051 /* send first frame */
1052
1053 isotp_create_fframe(cf, so, ae);
1054
1055 if (isotp_bc_flags(so) == CAN_ISOTP_CF_BROADCAST) {
1056 /* set timer for FC-less operation (STmin = 0) */
1057 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
1058 so->tx_gap = ktime_set(0, so->force_tx_stmin);
1059 else
1060 so->tx_gap = ktime_set(0, so->frame_txtime);
1061
1062 /* disable wait for FCs due to activated block size */
1063 so->txfc.bs = 0;
1064
1065 /* set CF echo tag for isotp_rcv_echo() (CF-mode) */
1066 so->cfecho = *(u32 *)cf->data;
1067 } else {
1068 /* standard flow control check */
1069 so->tx.state = ISOTP_WAIT_FIRST_FC;
1070
1071 /* start timeout for FC */
1072 hrtimer_sec = ISOTP_FC_TIMEOUT;
1073
1074 /* no CF echo tag for isotp_rcv_echo() (FF-mode) */
1075 so->cfecho = 0;
1076 }
1077 }
1078
1079 hrtimer_start(&so->txtimer, ktime_set(hrtimer_sec, 0),
1080 HRTIMER_MODE_REL_SOFT);
1081
1082 /* send the first or only CAN frame */
1083 cf->flags = so->ll.tx_flags;
1084
1085 skb->dev = dev;
1086 skb->sk = sk;
1087 err = can_send(skb, 1);
1088 dev_put(dev);
1089 if (err) {
1090 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
1091 __func__, ERR_PTR(err));
1092
1093 /* no transmission -> no timeout monitoring */
1094 hrtimer_cancel(&so->txtimer);
1095
1096 /* reset consecutive frame echo tag */
1097 so->cfecho = 0;
1098
1099 goto err_out_drop;
1100 }
1101
1102 if (wait_tx_done) {
1103 /* wait for complete transmission of current pdu */
1104 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1105 if (err)
1106 goto err_event_drop;
1107
1108 err = sock_error(sk);
1109 if (err)
1110 return err;
1111 }
1112
1113 return size;
1114
1115err_event_drop:
1116 /* got signal: force tx state machine to be idle */
1117 so->tx.state = ISOTP_IDLE;
1118 hrtimer_cancel(&so->txfrtimer);
1119 hrtimer_cancel(&so->txtimer);
1120err_out_drop:
1121 /* drop this PDU and unlock a potential wait queue */
1122 so->tx.state = ISOTP_IDLE;
1123 wake_up_interruptible(&so->wait);
1124
1125 return err;
1126}
1127
1128static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1129 int flags)
1130{
1131 struct sock *sk = sock->sk;
1132 struct sk_buff *skb;
1133 struct isotp_sock *so = isotp_sk(sk);
1134 int ret = 0;
1135
1136 if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK | MSG_CMSG_COMPAT))
1137 return -EINVAL;
1138
1139 if (!so->bound)
1140 return -EADDRNOTAVAIL;
1141
1142 skb = skb_recv_datagram(sk, flags, &ret);
1143 if (!skb)
1144 return ret;
1145
1146 if (size < skb->len)
1147 msg->msg_flags |= MSG_TRUNC;
1148 else
1149 size = skb->len;
1150
1151 ret = memcpy_to_msg(msg, skb->data, size);
1152 if (ret < 0)
1153 goto out_err;
1154
1155 sock_recv_cmsgs(msg, sk, skb);
1156
1157 if (msg->msg_name) {
1158 __sockaddr_check_size(ISOTP_MIN_NAMELEN);
1159 msg->msg_namelen = ISOTP_MIN_NAMELEN;
1160 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1161 }
1162
1163 /* set length of return value */
1164 ret = (flags & MSG_TRUNC) ? skb->len : size;
1165
1166out_err:
1167 skb_free_datagram(sk, skb);
1168
1169 return ret;
1170}
1171
1172static int isotp_release(struct socket *sock)
1173{
1174 struct sock *sk = sock->sk;
1175 struct isotp_sock *so;
1176 struct net *net;
1177
1178 if (!sk)
1179 return 0;
1180
1181 so = isotp_sk(sk);
1182 net = sock_net(sk);
1183
1184 /* wait for complete transmission of current pdu */
1185 while (wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE) == 0 &&
1186 cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SHUTDOWN) != ISOTP_IDLE)
1187 ;
1188
1189 /* force state machines to be idle also when a signal occurred */
1190 so->tx.state = ISOTP_SHUTDOWN;
1191 so->rx.state = ISOTP_IDLE;
1192
1193 spin_lock(&isotp_notifier_lock);
1194 while (isotp_busy_notifier == so) {
1195 spin_unlock(&isotp_notifier_lock);
1196 schedule_timeout_uninterruptible(1);
1197 spin_lock(&isotp_notifier_lock);
1198 }
1199 list_del(&so->notifier);
1200 spin_unlock(&isotp_notifier_lock);
1201
1202 lock_sock(sk);
1203
1204 /* remove current filters & unregister */
1205 if (so->bound) {
1206 if (so->ifindex) {
1207 struct net_device *dev;
1208
1209 dev = dev_get_by_index(net, so->ifindex);
1210 if (dev) {
1211 if (isotp_register_rxid(so))
1212 can_rx_unregister(net, dev, so->rxid,
1213 SINGLE_MASK(so->rxid),
1214 isotp_rcv, sk);
1215
1216 can_rx_unregister(net, dev, so->txid,
1217 SINGLE_MASK(so->txid),
1218 isotp_rcv_echo, sk);
1219 dev_put(dev);
1220 synchronize_rcu();
1221 }
1222 }
1223 }
1224
1225 hrtimer_cancel(&so->txfrtimer);
1226 hrtimer_cancel(&so->txtimer);
1227 hrtimer_cancel(&so->rxtimer);
1228
1229 so->ifindex = 0;
1230 so->bound = 0;
1231
1232 if (so->rx.buf != so->rx.sbuf)
1233 kfree(so->rx.buf);
1234
1235 if (so->tx.buf != so->tx.sbuf)
1236 kfree(so->tx.buf);
1237
1238 sock_orphan(sk);
1239 sock->sk = NULL;
1240
1241 release_sock(sk);
1242 sock_put(sk);
1243
1244 return 0;
1245}
1246
1247static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1248{
1249 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1250 struct sock *sk = sock->sk;
1251 struct isotp_sock *so = isotp_sk(sk);
1252 struct net *net = sock_net(sk);
1253 int ifindex;
1254 struct net_device *dev;
1255 canid_t tx_id = addr->can_addr.tp.tx_id;
1256 canid_t rx_id = addr->can_addr.tp.rx_id;
1257 int err = 0;
1258 int notify_enetdown = 0;
1259
1260 if (len < ISOTP_MIN_NAMELEN)
1261 return -EINVAL;
1262
1263 if (addr->can_family != AF_CAN)
1264 return -EINVAL;
1265
1266 /* sanitize tx CAN identifier */
1267 if (tx_id & CAN_EFF_FLAG)
1268 tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1269 else
1270 tx_id &= CAN_SFF_MASK;
1271
1272 /* give feedback on wrong CAN-ID value */
1273 if (tx_id != addr->can_addr.tp.tx_id)
1274 return -EINVAL;
1275
1276 /* sanitize rx CAN identifier (if needed) */
1277 if (isotp_register_rxid(so)) {
1278 if (rx_id & CAN_EFF_FLAG)
1279 rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1280 else
1281 rx_id &= CAN_SFF_MASK;
1282
1283 /* give feedback on wrong CAN-ID value */
1284 if (rx_id != addr->can_addr.tp.rx_id)
1285 return -EINVAL;
1286 }
1287
1288 if (!addr->can_ifindex)
1289 return -ENODEV;
1290
1291 lock_sock(sk);
1292
1293 if (so->bound) {
1294 err = -EINVAL;
1295 goto out;
1296 }
1297
1298 /* ensure different CAN IDs when the rx_id is to be registered */
1299 if (isotp_register_rxid(so) && rx_id == tx_id) {
1300 err = -EADDRNOTAVAIL;
1301 goto out;
1302 }
1303
1304 dev = dev_get_by_index(net, addr->can_ifindex);
1305 if (!dev) {
1306 err = -ENODEV;
1307 goto out;
1308 }
1309 if (dev->type != ARPHRD_CAN) {
1310 dev_put(dev);
1311 err = -ENODEV;
1312 goto out;
1313 }
1314 if (dev->mtu < so->ll.mtu) {
1315 dev_put(dev);
1316 err = -EINVAL;
1317 goto out;
1318 }
1319 if (!(dev->flags & IFF_UP))
1320 notify_enetdown = 1;
1321
1322 ifindex = dev->ifindex;
1323
1324 if (isotp_register_rxid(so))
1325 can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
1326 isotp_rcv, sk, "isotp", sk);
1327
1328 /* no consecutive frame echo skb in flight */
1329 so->cfecho = 0;
1330
1331 /* register for echo skb's */
1332 can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
1333 isotp_rcv_echo, sk, "isotpe", sk);
1334
1335 dev_put(dev);
1336
1337 /* switch to new settings */
1338 so->ifindex = ifindex;
1339 so->rxid = rx_id;
1340 so->txid = tx_id;
1341 so->bound = 1;
1342
1343out:
1344 release_sock(sk);
1345
1346 if (notify_enetdown) {
1347 sk->sk_err = ENETDOWN;
1348 if (!sock_flag(sk, SOCK_DEAD))
1349 sk_error_report(sk);
1350 }
1351
1352 return err;
1353}
1354
1355static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1356{
1357 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1358 struct sock *sk = sock->sk;
1359 struct isotp_sock *so = isotp_sk(sk);
1360
1361 if (peer)
1362 return -EOPNOTSUPP;
1363
1364 memset(addr, 0, ISOTP_MIN_NAMELEN);
1365 addr->can_family = AF_CAN;
1366 addr->can_ifindex = so->ifindex;
1367 addr->can_addr.tp.rx_id = so->rxid;
1368 addr->can_addr.tp.tx_id = so->txid;
1369
1370 return ISOTP_MIN_NAMELEN;
1371}
1372
1373static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
1374 sockptr_t optval, unsigned int optlen)
1375{
1376 struct sock *sk = sock->sk;
1377 struct isotp_sock *so = isotp_sk(sk);
1378 int ret = 0;
1379
1380 if (so->bound)
1381 return -EISCONN;
1382
1383 switch (optname) {
1384 case CAN_ISOTP_OPTS:
1385 if (optlen != sizeof(struct can_isotp_options))
1386 return -EINVAL;
1387
1388 if (copy_from_sockptr(&so->opt, optval, optlen))
1389 return -EFAULT;
1390
1391 /* no separate rx_ext_address is given => use ext_address */
1392 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1393 so->opt.rx_ext_address = so->opt.ext_address;
1394
1395 /* these broadcast flags are not allowed together */
1396 if (isotp_bc_flags(so) == ISOTP_ALL_BC_FLAGS) {
1397 /* CAN_ISOTP_SF_BROADCAST is prioritized */
1398 so->opt.flags &= ~CAN_ISOTP_CF_BROADCAST;
1399
1400 /* give user feedback on wrong config attempt */
1401 ret = -EINVAL;
1402 }
1403
1404 /* check for frame_txtime changes (0 => no changes) */
1405 if (so->opt.frame_txtime) {
1406 if (so->opt.frame_txtime == CAN_ISOTP_FRAME_TXTIME_ZERO)
1407 so->frame_txtime = 0;
1408 else
1409 so->frame_txtime = so->opt.frame_txtime;
1410 }
1411 break;
1412
1413 case CAN_ISOTP_RECV_FC:
1414 if (optlen != sizeof(struct can_isotp_fc_options))
1415 return -EINVAL;
1416
1417 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1418 return -EFAULT;
1419 break;
1420
1421 case CAN_ISOTP_TX_STMIN:
1422 if (optlen != sizeof(u32))
1423 return -EINVAL;
1424
1425 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1426 return -EFAULT;
1427 break;
1428
1429 case CAN_ISOTP_RX_STMIN:
1430 if (optlen != sizeof(u32))
1431 return -EINVAL;
1432
1433 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1434 return -EFAULT;
1435 break;
1436
1437 case CAN_ISOTP_LL_OPTS:
1438 if (optlen == sizeof(struct can_isotp_ll_options)) {
1439 struct can_isotp_ll_options ll;
1440
1441 if (copy_from_sockptr(&ll, optval, optlen))
1442 return -EFAULT;
1443
1444 /* check for correct ISO 11898-1 DLC data length */
1445 if (ll.tx_dl != padlen(ll.tx_dl))
1446 return -EINVAL;
1447
1448 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1449 return -EINVAL;
1450
1451 if (ll.mtu == CAN_MTU &&
1452 (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1453 return -EINVAL;
1454
1455 memcpy(&so->ll, &ll, sizeof(ll));
1456
1457 /* set ll_dl for tx path to similar place as for rx */
1458 so->tx.ll_dl = ll.tx_dl;
1459 } else {
1460 return -EINVAL;
1461 }
1462 break;
1463
1464 default:
1465 ret = -ENOPROTOOPT;
1466 }
1467
1468 return ret;
1469}
1470
1471static int isotp_setsockopt(struct socket *sock, int level, int optname,
1472 sockptr_t optval, unsigned int optlen)
1473
1474{
1475 struct sock *sk = sock->sk;
1476 int ret;
1477
1478 if (level != SOL_CAN_ISOTP)
1479 return -EINVAL;
1480
1481 lock_sock(sk);
1482 ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
1483 release_sock(sk);
1484 return ret;
1485}
1486
1487static int isotp_getsockopt(struct socket *sock, int level, int optname,
1488 char __user *optval, int __user *optlen)
1489{
1490 struct sock *sk = sock->sk;
1491 struct isotp_sock *so = isotp_sk(sk);
1492 int len;
1493 void *val;
1494
1495 if (level != SOL_CAN_ISOTP)
1496 return -EINVAL;
1497 if (get_user(len, optlen))
1498 return -EFAULT;
1499 if (len < 0)
1500 return -EINVAL;
1501
1502 switch (optname) {
1503 case CAN_ISOTP_OPTS:
1504 len = min_t(int, len, sizeof(struct can_isotp_options));
1505 val = &so->opt;
1506 break;
1507
1508 case CAN_ISOTP_RECV_FC:
1509 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1510 val = &so->rxfc;
1511 break;
1512
1513 case CAN_ISOTP_TX_STMIN:
1514 len = min_t(int, len, sizeof(u32));
1515 val = &so->force_tx_stmin;
1516 break;
1517
1518 case CAN_ISOTP_RX_STMIN:
1519 len = min_t(int, len, sizeof(u32));
1520 val = &so->force_rx_stmin;
1521 break;
1522
1523 case CAN_ISOTP_LL_OPTS:
1524 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1525 val = &so->ll;
1526 break;
1527
1528 default:
1529 return -ENOPROTOOPT;
1530 }
1531
1532 if (put_user(len, optlen))
1533 return -EFAULT;
1534 if (copy_to_user(optval, val, len))
1535 return -EFAULT;
1536 return 0;
1537}
1538
1539static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1540 struct net_device *dev)
1541{
1542 struct sock *sk = &so->sk;
1543
1544 if (!net_eq(dev_net(dev), sock_net(sk)))
1545 return;
1546
1547 if (so->ifindex != dev->ifindex)
1548 return;
1549
1550 switch (msg) {
1551 case NETDEV_UNREGISTER:
1552 lock_sock(sk);
1553 /* remove current filters & unregister */
1554 if (so->bound) {
1555 if (isotp_register_rxid(so))
1556 can_rx_unregister(dev_net(dev), dev, so->rxid,
1557 SINGLE_MASK(so->rxid),
1558 isotp_rcv, sk);
1559
1560 can_rx_unregister(dev_net(dev), dev, so->txid,
1561 SINGLE_MASK(so->txid),
1562 isotp_rcv_echo, sk);
1563 }
1564
1565 so->ifindex = 0;
1566 so->bound = 0;
1567 release_sock(sk);
1568
1569 sk->sk_err = ENODEV;
1570 if (!sock_flag(sk, SOCK_DEAD))
1571 sk_error_report(sk);
1572 break;
1573
1574 case NETDEV_DOWN:
1575 sk->sk_err = ENETDOWN;
1576 if (!sock_flag(sk, SOCK_DEAD))
1577 sk_error_report(sk);
1578 break;
1579 }
1580}
1581
1582static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1583 void *ptr)
1584{
1585 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1586
1587 if (dev->type != ARPHRD_CAN)
1588 return NOTIFY_DONE;
1589 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1590 return NOTIFY_DONE;
1591 if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1592 return NOTIFY_DONE;
1593
1594 spin_lock(&isotp_notifier_lock);
1595 list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1596 spin_unlock(&isotp_notifier_lock);
1597 isotp_notify(isotp_busy_notifier, msg, dev);
1598 spin_lock(&isotp_notifier_lock);
1599 }
1600 isotp_busy_notifier = NULL;
1601 spin_unlock(&isotp_notifier_lock);
1602 return NOTIFY_DONE;
1603}
1604
1605static int isotp_init(struct sock *sk)
1606{
1607 struct isotp_sock *so = isotp_sk(sk);
1608
1609 so->ifindex = 0;
1610 so->bound = 0;
1611
1612 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1613 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1614 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1615 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1616 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1617 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1618 so->frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1619 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1620 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1621 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1622 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1623 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1624 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1625
1626 /* set ll_dl for tx path to similar place as for rx */
1627 so->tx.ll_dl = so->ll.tx_dl;
1628
1629 so->rx.state = ISOTP_IDLE;
1630 so->tx.state = ISOTP_IDLE;
1631
1632 so->rx.buf = so->rx.sbuf;
1633 so->tx.buf = so->tx.sbuf;
1634 so->rx.buflen = ARRAY_SIZE(so->rx.sbuf);
1635 so->tx.buflen = ARRAY_SIZE(so->tx.sbuf);
1636
1637 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1638 so->rxtimer.function = isotp_rx_timer_handler;
1639 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1640 so->txtimer.function = isotp_tx_timer_handler;
1641 hrtimer_init(&so->txfrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1642 so->txfrtimer.function = isotp_txfr_timer_handler;
1643
1644 init_waitqueue_head(&so->wait);
1645 spin_lock_init(&so->rx_lock);
1646
1647 spin_lock(&isotp_notifier_lock);
1648 list_add_tail(&so->notifier, &isotp_notifier_list);
1649 spin_unlock(&isotp_notifier_lock);
1650
1651 return 0;
1652}
1653
1654static __poll_t isotp_poll(struct file *file, struct socket *sock, poll_table *wait)
1655{
1656 struct sock *sk = sock->sk;
1657 struct isotp_sock *so = isotp_sk(sk);
1658
1659 __poll_t mask = datagram_poll(file, sock, wait);
1660 poll_wait(file, &so->wait, wait);
1661
1662 /* Check for false positives due to TX state */
1663 if ((mask & EPOLLWRNORM) && (so->tx.state != ISOTP_IDLE))
1664 mask &= ~(EPOLLOUT | EPOLLWRNORM);
1665
1666 return mask;
1667}
1668
1669static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1670 unsigned long arg)
1671{
1672 /* no ioctls for socket layer -> hand it down to NIC layer */
1673 return -ENOIOCTLCMD;
1674}
1675
1676static const struct proto_ops isotp_ops = {
1677 .family = PF_CAN,
1678 .release = isotp_release,
1679 .bind = isotp_bind,
1680 .connect = sock_no_connect,
1681 .socketpair = sock_no_socketpair,
1682 .accept = sock_no_accept,
1683 .getname = isotp_getname,
1684 .poll = isotp_poll,
1685 .ioctl = isotp_sock_no_ioctlcmd,
1686 .gettstamp = sock_gettstamp,
1687 .listen = sock_no_listen,
1688 .shutdown = sock_no_shutdown,
1689 .setsockopt = isotp_setsockopt,
1690 .getsockopt = isotp_getsockopt,
1691 .sendmsg = isotp_sendmsg,
1692 .recvmsg = isotp_recvmsg,
1693 .mmap = sock_no_mmap,
1694};
1695
1696static struct proto isotp_proto __read_mostly = {
1697 .name = "CAN_ISOTP",
1698 .owner = THIS_MODULE,
1699 .obj_size = sizeof(struct isotp_sock),
1700 .init = isotp_init,
1701};
1702
1703static const struct can_proto isotp_can_proto = {
1704 .type = SOCK_DGRAM,
1705 .protocol = CAN_ISOTP,
1706 .ops = &isotp_ops,
1707 .prot = &isotp_proto,
1708};
1709
1710static struct notifier_block canisotp_notifier = {
1711 .notifier_call = isotp_notifier
1712};
1713
1714static __init int isotp_module_init(void)
1715{
1716 int err;
1717
1718 max_pdu_size = max_t(unsigned int, max_pdu_size, MAX_12BIT_PDU_SIZE);
1719 max_pdu_size = min_t(unsigned int, max_pdu_size, MAX_PDU_SIZE);
1720
1721 pr_info("can: isotp protocol (max_pdu_size %d)\n", max_pdu_size);
1722
1723 err = can_proto_register(&isotp_can_proto);
1724 if (err < 0)
1725 pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
1726 else
1727 register_netdevice_notifier(&canisotp_notifier);
1728
1729 return err;
1730}
1731
1732static __exit void isotp_module_exit(void)
1733{
1734 can_proto_unregister(&isotp_can_proto);
1735 unregister_netdevice_notifier(&canisotp_notifier);
1736}
1737
1738module_init(isotp_module_init);
1739module_exit(isotp_module_exit);
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
75MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
76MODULE_LICENSE("Dual BSD/GPL");
77MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
78MODULE_ALIAS("can-proto-6");
79
80#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
81
82#define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
83 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
84 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
85
86/* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
87 * take full 32 bit values (4 Gbyte). We would need some good concept to handle
88 * this between user space and kernel space. For now increase the static buffer
89 * to something about 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
113enum {
114 ISOTP_IDLE = 0,
115 ISOTP_WAIT_FIRST_FC,
116 ISOTP_WAIT_FC,
117 ISOTP_WAIT_DATA,
118 ISOTP_SENDING
119};
120
121struct tpcon {
122 int idx;
123 int len;
124 u32 state;
125 u8 bs;
126 u8 sn;
127 u8 ll_dl;
128 u8 buf[MAX_MSG_LENGTH + 1];
129};
130
131struct 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
150static LIST_HEAD(isotp_notifier_list);
151static DEFINE_SPINLOCK(isotp_notifier_lock);
152static struct isotp_sock *isotp_busy_notifier;
153
154static inline struct isotp_sock *isotp_sk(const struct sock *sk)
155{
156 return (struct isotp_sock *)sk;
157}
158
159static 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_error_report(sk);
172
173 /* reset rx state */
174 so->rx.state = ISOTP_IDLE;
175 }
176
177 return HRTIMER_NORESTART;
178}
179
180static 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 %pe\n",
229 __func__, ERR_PTR(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
244static 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
258static 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 */
278static 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 */
298static 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
326static 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_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_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
406static 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_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
439static 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
502static 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_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_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
596static 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
673static 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
704static 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
740static 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_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
775isotp_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 %pe\n",
806 __func__, ERR_PTR(can_send_ret));
807 if (can_send_ret == -ENOBUFS)
808 pr_notice_once("can-isotp: tx queue is full, increasing txqueuelen may prevent this error\n");
809 }
810 if (so->tx.idx >= so->tx.len) {
811 /* we are done */
812 so->tx.state = ISOTP_IDLE;
813 dev_put(dev);
814 wake_up_interruptible(&so->wait);
815 break;
816 }
817
818 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
819 /* stop and wait for FC */
820 so->tx.state = ISOTP_WAIT_FC;
821 dev_put(dev);
822 hrtimer_set_expires(&so->txtimer,
823 ktime_add(ktime_get(),
824 ktime_set(1, 0)));
825 restart = HRTIMER_RESTART;
826 break;
827 }
828
829 /* no gap between data frames needed => use burst mode */
830 if (!so->tx_gap)
831 goto isotp_tx_burst;
832
833 /* start timer to send next data frame with correct delay */
834 dev_put(dev);
835 hrtimer_set_expires(&so->txtimer,
836 ktime_add(ktime_get(), so->tx_gap));
837 restart = HRTIMER_RESTART;
838 break;
839
840 default:
841 WARN_ON_ONCE(1);
842 }
843
844 return restart;
845}
846
847static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
848{
849 struct sock *sk = sock->sk;
850 struct isotp_sock *so = isotp_sk(sk);
851 u32 old_state = so->tx.state;
852 struct sk_buff *skb;
853 struct net_device *dev;
854 struct canfd_frame *cf;
855 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
856 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
857 int off;
858 int err;
859
860 if (!so->bound)
861 return -EADDRNOTAVAIL;
862
863 /* we do not support multiple buffers - for now */
864 if (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE ||
865 wq_has_sleeper(&so->wait)) {
866 if (msg->msg_flags & MSG_DONTWAIT) {
867 err = -EAGAIN;
868 goto err_out;
869 }
870
871 /* wait for complete transmission of current pdu */
872 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
873 if (err)
874 goto err_out;
875 }
876
877 if (!size || size > MAX_MSG_LENGTH) {
878 err = -EINVAL;
879 goto err_out;
880 }
881
882 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
883 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
884
885 /* does the given data fit into a single frame for SF_BROADCAST? */
886 if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) &&
887 (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
888 err = -EINVAL;
889 goto err_out;
890 }
891
892 err = memcpy_from_msg(so->tx.buf, msg, size);
893 if (err < 0)
894 goto err_out;
895
896 dev = dev_get_by_index(sock_net(sk), so->ifindex);
897 if (!dev) {
898 err = -ENXIO;
899 goto err_out;
900 }
901
902 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
903 msg->msg_flags & MSG_DONTWAIT, &err);
904 if (!skb) {
905 dev_put(dev);
906 goto err_out;
907 }
908
909 can_skb_reserve(skb);
910 can_skb_prv(skb)->ifindex = dev->ifindex;
911 can_skb_prv(skb)->skbcnt = 0;
912
913 so->tx.len = size;
914 so->tx.idx = 0;
915
916 cf = (struct canfd_frame *)skb->data;
917 skb_put_zero(skb, so->ll.mtu);
918
919 /* check for single frame transmission depending on TX_DL */
920 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
921 /* The message size generally fits into a SingleFrame - good.
922 *
923 * SF_DL ESC offset optimization:
924 *
925 * When TX_DL is greater 8 but the message would still fit
926 * into a 8 byte CAN frame, we can omit the offset.
927 * This prevents a protocol caused length extension from
928 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
929 */
930 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
931 off = 0;
932
933 isotp_fill_dataframe(cf, so, ae, off);
934
935 /* place single frame N_PCI w/o length in appropriate index */
936 cf->data[ae] = N_PCI_SF;
937
938 /* place SF_DL size value depending on the SF_DL ESC offset */
939 if (off)
940 cf->data[SF_PCI_SZ4 + ae] = size;
941 else
942 cf->data[ae] |= size;
943
944 so->tx.state = ISOTP_IDLE;
945 wake_up_interruptible(&so->wait);
946
947 /* don't enable wait queue for a single frame transmission */
948 wait_tx_done = 0;
949 } else {
950 /* send first frame and wait for FC */
951
952 isotp_create_fframe(cf, so, ae);
953
954 /* start timeout for FC */
955 hrtimer_start(&so->txtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
956 }
957
958 /* send the first or only CAN frame */
959 cf->flags = so->ll.tx_flags;
960
961 skb->dev = dev;
962 skb->sk = sk;
963 err = can_send(skb, 1);
964 dev_put(dev);
965 if (err) {
966 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
967 __func__, ERR_PTR(err));
968 goto err_out;
969 }
970
971 if (wait_tx_done) {
972 /* wait for complete transmission of current pdu */
973 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
974
975 if (sk->sk_err)
976 return -sk->sk_err;
977 }
978
979 return size;
980
981err_out:
982 so->tx.state = old_state;
983 if (so->tx.state == ISOTP_IDLE)
984 wake_up_interruptible(&so->wait);
985
986 return err;
987}
988
989static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
990 int flags)
991{
992 struct sock *sk = sock->sk;
993 struct sk_buff *skb;
994 int err = 0;
995 int noblock;
996
997 noblock = flags & MSG_DONTWAIT;
998 flags &= ~MSG_DONTWAIT;
999
1000 skb = skb_recv_datagram(sk, flags, noblock, &err);
1001 if (!skb)
1002 return err;
1003
1004 if (size < skb->len)
1005 msg->msg_flags |= MSG_TRUNC;
1006 else
1007 size = skb->len;
1008
1009 err = memcpy_to_msg(msg, skb->data, size);
1010 if (err < 0) {
1011 skb_free_datagram(sk, skb);
1012 return err;
1013 }
1014
1015 sock_recv_timestamp(msg, sk, skb);
1016
1017 if (msg->msg_name) {
1018 __sockaddr_check_size(ISOTP_MIN_NAMELEN);
1019 msg->msg_namelen = ISOTP_MIN_NAMELEN;
1020 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1021 }
1022
1023 skb_free_datagram(sk, skb);
1024
1025 return size;
1026}
1027
1028static int isotp_release(struct socket *sock)
1029{
1030 struct sock *sk = sock->sk;
1031 struct isotp_sock *so;
1032 struct net *net;
1033
1034 if (!sk)
1035 return 0;
1036
1037 so = isotp_sk(sk);
1038 net = sock_net(sk);
1039
1040 /* wait for complete transmission of current pdu */
1041 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1042
1043 spin_lock(&isotp_notifier_lock);
1044 while (isotp_busy_notifier == so) {
1045 spin_unlock(&isotp_notifier_lock);
1046 schedule_timeout_uninterruptible(1);
1047 spin_lock(&isotp_notifier_lock);
1048 }
1049 list_del(&so->notifier);
1050 spin_unlock(&isotp_notifier_lock);
1051
1052 lock_sock(sk);
1053
1054 /* remove current filters & unregister */
1055 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) {
1056 if (so->ifindex) {
1057 struct net_device *dev;
1058
1059 dev = dev_get_by_index(net, so->ifindex);
1060 if (dev) {
1061 can_rx_unregister(net, dev, so->rxid,
1062 SINGLE_MASK(so->rxid),
1063 isotp_rcv, sk);
1064 dev_put(dev);
1065 synchronize_rcu();
1066 }
1067 }
1068 }
1069
1070 hrtimer_cancel(&so->txtimer);
1071 hrtimer_cancel(&so->rxtimer);
1072
1073 so->ifindex = 0;
1074 so->bound = 0;
1075
1076 sock_orphan(sk);
1077 sock->sk = NULL;
1078
1079 release_sock(sk);
1080 sock_put(sk);
1081
1082 return 0;
1083}
1084
1085static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1086{
1087 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1088 struct sock *sk = sock->sk;
1089 struct isotp_sock *so = isotp_sk(sk);
1090 struct net *net = sock_net(sk);
1091 int ifindex;
1092 struct net_device *dev;
1093 int err = 0;
1094 int notify_enetdown = 0;
1095 int do_rx_reg = 1;
1096
1097 if (len < ISOTP_MIN_NAMELEN)
1098 return -EINVAL;
1099
1100 if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
1101 return -EADDRNOTAVAIL;
1102
1103 if (!addr->can_ifindex)
1104 return -ENODEV;
1105
1106 lock_sock(sk);
1107
1108 /* do not register frame reception for functional addressing */
1109 if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
1110 do_rx_reg = 0;
1111
1112 /* do not validate rx address for functional addressing */
1113 if (do_rx_reg) {
1114 if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id) {
1115 err = -EADDRNOTAVAIL;
1116 goto out;
1117 }
1118
1119 if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
1120 err = -EADDRNOTAVAIL;
1121 goto out;
1122 }
1123 }
1124
1125 if (so->bound && addr->can_ifindex == so->ifindex &&
1126 addr->can_addr.tp.rx_id == so->rxid &&
1127 addr->can_addr.tp.tx_id == so->txid)
1128 goto out;
1129
1130 dev = dev_get_by_index(net, addr->can_ifindex);
1131 if (!dev) {
1132 err = -ENODEV;
1133 goto out;
1134 }
1135 if (dev->type != ARPHRD_CAN) {
1136 dev_put(dev);
1137 err = -ENODEV;
1138 goto out;
1139 }
1140 if (dev->mtu < so->ll.mtu) {
1141 dev_put(dev);
1142 err = -EINVAL;
1143 goto out;
1144 }
1145 if (!(dev->flags & IFF_UP))
1146 notify_enetdown = 1;
1147
1148 ifindex = dev->ifindex;
1149
1150 if (do_rx_reg)
1151 can_rx_register(net, dev, addr->can_addr.tp.rx_id,
1152 SINGLE_MASK(addr->can_addr.tp.rx_id),
1153 isotp_rcv, sk, "isotp", sk);
1154
1155 dev_put(dev);
1156
1157 if (so->bound && do_rx_reg) {
1158 /* unregister old filter */
1159 if (so->ifindex) {
1160 dev = dev_get_by_index(net, so->ifindex);
1161 if (dev) {
1162 can_rx_unregister(net, dev, so->rxid,
1163 SINGLE_MASK(so->rxid),
1164 isotp_rcv, sk);
1165 dev_put(dev);
1166 }
1167 }
1168 }
1169
1170 /* switch to new settings */
1171 so->ifindex = ifindex;
1172 so->rxid = addr->can_addr.tp.rx_id;
1173 so->txid = addr->can_addr.tp.tx_id;
1174 so->bound = 1;
1175
1176out:
1177 release_sock(sk);
1178
1179 if (notify_enetdown) {
1180 sk->sk_err = ENETDOWN;
1181 if (!sock_flag(sk, SOCK_DEAD))
1182 sk_error_report(sk);
1183 }
1184
1185 return err;
1186}
1187
1188static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1189{
1190 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1191 struct sock *sk = sock->sk;
1192 struct isotp_sock *so = isotp_sk(sk);
1193
1194 if (peer)
1195 return -EOPNOTSUPP;
1196
1197 memset(addr, 0, ISOTP_MIN_NAMELEN);
1198 addr->can_family = AF_CAN;
1199 addr->can_ifindex = so->ifindex;
1200 addr->can_addr.tp.rx_id = so->rxid;
1201 addr->can_addr.tp.tx_id = so->txid;
1202
1203 return ISOTP_MIN_NAMELEN;
1204}
1205
1206static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
1207 sockptr_t optval, unsigned int optlen)
1208{
1209 struct sock *sk = sock->sk;
1210 struct isotp_sock *so = isotp_sk(sk);
1211 int ret = 0;
1212
1213 if (so->bound)
1214 return -EISCONN;
1215
1216 switch (optname) {
1217 case CAN_ISOTP_OPTS:
1218 if (optlen != sizeof(struct can_isotp_options))
1219 return -EINVAL;
1220
1221 if (copy_from_sockptr(&so->opt, optval, optlen))
1222 return -EFAULT;
1223
1224 /* no separate rx_ext_address is given => use ext_address */
1225 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1226 so->opt.rx_ext_address = so->opt.ext_address;
1227 break;
1228
1229 case CAN_ISOTP_RECV_FC:
1230 if (optlen != sizeof(struct can_isotp_fc_options))
1231 return -EINVAL;
1232
1233 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1234 return -EFAULT;
1235 break;
1236
1237 case CAN_ISOTP_TX_STMIN:
1238 if (optlen != sizeof(u32))
1239 return -EINVAL;
1240
1241 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1242 return -EFAULT;
1243 break;
1244
1245 case CAN_ISOTP_RX_STMIN:
1246 if (optlen != sizeof(u32))
1247 return -EINVAL;
1248
1249 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1250 return -EFAULT;
1251 break;
1252
1253 case CAN_ISOTP_LL_OPTS:
1254 if (optlen == sizeof(struct can_isotp_ll_options)) {
1255 struct can_isotp_ll_options ll;
1256
1257 if (copy_from_sockptr(&ll, optval, optlen))
1258 return -EFAULT;
1259
1260 /* check for correct ISO 11898-1 DLC data length */
1261 if (ll.tx_dl != padlen(ll.tx_dl))
1262 return -EINVAL;
1263
1264 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1265 return -EINVAL;
1266
1267 if (ll.mtu == CAN_MTU &&
1268 (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1269 return -EINVAL;
1270
1271 memcpy(&so->ll, &ll, sizeof(ll));
1272
1273 /* set ll_dl for tx path to similar place as for rx */
1274 so->tx.ll_dl = ll.tx_dl;
1275 } else {
1276 return -EINVAL;
1277 }
1278 break;
1279
1280 default:
1281 ret = -ENOPROTOOPT;
1282 }
1283
1284 return ret;
1285}
1286
1287static int isotp_setsockopt(struct socket *sock, int level, int optname,
1288 sockptr_t optval, unsigned int optlen)
1289
1290{
1291 struct sock *sk = sock->sk;
1292 int ret;
1293
1294 if (level != SOL_CAN_ISOTP)
1295 return -EINVAL;
1296
1297 lock_sock(sk);
1298 ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
1299 release_sock(sk);
1300 return ret;
1301}
1302
1303static int isotp_getsockopt(struct socket *sock, int level, int optname,
1304 char __user *optval, int __user *optlen)
1305{
1306 struct sock *sk = sock->sk;
1307 struct isotp_sock *so = isotp_sk(sk);
1308 int len;
1309 void *val;
1310
1311 if (level != SOL_CAN_ISOTP)
1312 return -EINVAL;
1313 if (get_user(len, optlen))
1314 return -EFAULT;
1315 if (len < 0)
1316 return -EINVAL;
1317
1318 switch (optname) {
1319 case CAN_ISOTP_OPTS:
1320 len = min_t(int, len, sizeof(struct can_isotp_options));
1321 val = &so->opt;
1322 break;
1323
1324 case CAN_ISOTP_RECV_FC:
1325 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1326 val = &so->rxfc;
1327 break;
1328
1329 case CAN_ISOTP_TX_STMIN:
1330 len = min_t(int, len, sizeof(u32));
1331 val = &so->force_tx_stmin;
1332 break;
1333
1334 case CAN_ISOTP_RX_STMIN:
1335 len = min_t(int, len, sizeof(u32));
1336 val = &so->force_rx_stmin;
1337 break;
1338
1339 case CAN_ISOTP_LL_OPTS:
1340 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1341 val = &so->ll;
1342 break;
1343
1344 default:
1345 return -ENOPROTOOPT;
1346 }
1347
1348 if (put_user(len, optlen))
1349 return -EFAULT;
1350 if (copy_to_user(optval, val, len))
1351 return -EFAULT;
1352 return 0;
1353}
1354
1355static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1356 struct net_device *dev)
1357{
1358 struct sock *sk = &so->sk;
1359
1360 if (!net_eq(dev_net(dev), sock_net(sk)))
1361 return;
1362
1363 if (so->ifindex != dev->ifindex)
1364 return;
1365
1366 switch (msg) {
1367 case NETDEV_UNREGISTER:
1368 lock_sock(sk);
1369 /* remove current filters & unregister */
1370 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))
1371 can_rx_unregister(dev_net(dev), dev, so->rxid,
1372 SINGLE_MASK(so->rxid),
1373 isotp_rcv, sk);
1374
1375 so->ifindex = 0;
1376 so->bound = 0;
1377 release_sock(sk);
1378
1379 sk->sk_err = ENODEV;
1380 if (!sock_flag(sk, SOCK_DEAD))
1381 sk_error_report(sk);
1382 break;
1383
1384 case NETDEV_DOWN:
1385 sk->sk_err = ENETDOWN;
1386 if (!sock_flag(sk, SOCK_DEAD))
1387 sk_error_report(sk);
1388 break;
1389 }
1390}
1391
1392static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1393 void *ptr)
1394{
1395 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1396
1397 if (dev->type != ARPHRD_CAN)
1398 return NOTIFY_DONE;
1399 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1400 return NOTIFY_DONE;
1401 if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1402 return NOTIFY_DONE;
1403
1404 spin_lock(&isotp_notifier_lock);
1405 list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1406 spin_unlock(&isotp_notifier_lock);
1407 isotp_notify(isotp_busy_notifier, msg, dev);
1408 spin_lock(&isotp_notifier_lock);
1409 }
1410 isotp_busy_notifier = NULL;
1411 spin_unlock(&isotp_notifier_lock);
1412 return NOTIFY_DONE;
1413}
1414
1415static int isotp_init(struct sock *sk)
1416{
1417 struct isotp_sock *so = isotp_sk(sk);
1418
1419 so->ifindex = 0;
1420 so->bound = 0;
1421
1422 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1423 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1424 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1425 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1426 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1427 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1428 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1429 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1430 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1431 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1432 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1433 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1434
1435 /* set ll_dl for tx path to similar place as for rx */
1436 so->tx.ll_dl = so->ll.tx_dl;
1437
1438 so->rx.state = ISOTP_IDLE;
1439 so->tx.state = ISOTP_IDLE;
1440
1441 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1442 so->rxtimer.function = isotp_rx_timer_handler;
1443 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1444 so->txtimer.function = isotp_tx_timer_handler;
1445
1446 init_waitqueue_head(&so->wait);
1447
1448 spin_lock(&isotp_notifier_lock);
1449 list_add_tail(&so->notifier, &isotp_notifier_list);
1450 spin_unlock(&isotp_notifier_lock);
1451
1452 return 0;
1453}
1454
1455static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1456 unsigned long arg)
1457{
1458 /* no ioctls for socket layer -> hand it down to NIC layer */
1459 return -ENOIOCTLCMD;
1460}
1461
1462static const struct proto_ops isotp_ops = {
1463 .family = PF_CAN,
1464 .release = isotp_release,
1465 .bind = isotp_bind,
1466 .connect = sock_no_connect,
1467 .socketpair = sock_no_socketpair,
1468 .accept = sock_no_accept,
1469 .getname = isotp_getname,
1470 .poll = datagram_poll,
1471 .ioctl = isotp_sock_no_ioctlcmd,
1472 .gettstamp = sock_gettstamp,
1473 .listen = sock_no_listen,
1474 .shutdown = sock_no_shutdown,
1475 .setsockopt = isotp_setsockopt,
1476 .getsockopt = isotp_getsockopt,
1477 .sendmsg = isotp_sendmsg,
1478 .recvmsg = isotp_recvmsg,
1479 .mmap = sock_no_mmap,
1480 .sendpage = sock_no_sendpage,
1481};
1482
1483static struct proto isotp_proto __read_mostly = {
1484 .name = "CAN_ISOTP",
1485 .owner = THIS_MODULE,
1486 .obj_size = sizeof(struct isotp_sock),
1487 .init = isotp_init,
1488};
1489
1490static const struct can_proto isotp_can_proto = {
1491 .type = SOCK_DGRAM,
1492 .protocol = CAN_ISOTP,
1493 .ops = &isotp_ops,
1494 .prot = &isotp_proto,
1495};
1496
1497static struct notifier_block canisotp_notifier = {
1498 .notifier_call = isotp_notifier
1499};
1500
1501static __init int isotp_module_init(void)
1502{
1503 int err;
1504
1505 pr_info("can: isotp protocol\n");
1506
1507 err = can_proto_register(&isotp_can_proto);
1508 if (err < 0)
1509 pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
1510 else
1511 register_netdevice_notifier(&canisotp_notifier);
1512
1513 return err;
1514}
1515
1516static __exit void isotp_module_exit(void)
1517{
1518 can_proto_unregister(&isotp_can_proto);
1519 unregister_netdevice_notifier(&canisotp_notifier);
1520}
1521
1522module_init(isotp_module_init);
1523module_exit(isotp_module_exit);