1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /* isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
4 * This implementation does not provide ISO-TP specific return values to the
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
19 * Copyright (c) 2020 Volkswagen Group Electronic Research
20 * All rights reserved.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
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.
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.
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.
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
56 #include <linux/module.h>
57 #include <linux/init.h>
58 #include <linux/interrupt.h>
59 #include <linux/spinlock.h>
60 #include <linux/hrtimer.h>
61 #include <linux/wait.h>
62 #include <linux/uio.h>
63 #include <linux/net.h>
64 #include <linux/netdevice.h>
65 #include <linux/socket.h>
66 #include <linux/if_arp.h>
67 #include <linux/skbuff.h>
68 #include <linux/can.h>
69 #include <linux/can/core.h>
70 #include <linux/can/skb.h>
71 #include <linux/can/isotp.h>
72 #include <linux/slab.h>
74 #include <net/net_namespace.h>
76 MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
77 MODULE_LICENSE("Dual BSD/GPL");
78 MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
79 MODULE_ALIAS("can-proto-6");
81 #define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
83 #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
84 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
85 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
87 /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
88 * take full 32 bit values (4 Gbyte). We would need some good concept to handle
89 * this between user space and kernel space. For now increase the static buffer
90 * to something about 8 kbyte to be able to test this new functionality.
92 #define MAX_MSG_LENGTH 8200
94 /* N_PCI type values in bits 7-4 of N_PCI bytes */
95 #define N_PCI_SF 0x00 /* single frame */
96 #define N_PCI_FF 0x10 /* first frame */
97 #define N_PCI_CF 0x20 /* consecutive frame */
98 #define N_PCI_FC 0x30 /* flow control */
100 #define N_PCI_SZ 1 /* size of the PCI byte #1 */
101 #define SF_PCI_SZ4 1 /* size of SingleFrame PCI including 4 bit SF_DL */
102 #define SF_PCI_SZ8 2 /* size of SingleFrame PCI including 8 bit SF_DL */
103 #define FF_PCI_SZ12 2 /* size of FirstFrame PCI including 12 bit FF_DL */
104 #define FF_PCI_SZ32 6 /* size of FirstFrame PCI including 32 bit FF_DL */
105 #define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
107 #define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
109 /* Flow Status given in FC frame */
110 #define ISOTP_FC_CTS 0 /* clear to send */
111 #define ISOTP_FC_WT 1 /* wait */
112 #define ISOTP_FC_OVFLW 2 /* overflow */
129 u8 buf[MAX_MSG_LENGTH + 1];
139 ktime_t lastrxcf_tstamp;
140 struct hrtimer rxtimer, txtimer;
141 struct can_isotp_options opt;
142 struct can_isotp_fc_options rxfc, txfc;
143 struct can_isotp_ll_options ll;
148 struct list_head notifier;
149 wait_queue_head_t wait;
150 spinlock_t rx_lock; /* protect single thread state machine */
153 static LIST_HEAD(isotp_notifier_list);
154 static DEFINE_SPINLOCK(isotp_notifier_lock);
155 static struct isotp_sock *isotp_busy_notifier;
157 static inline struct isotp_sock *isotp_sk(const struct sock *sk)
159 return (struct isotp_sock *)sk;
162 static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
164 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
166 struct sock *sk = &so->sk;
168 if (so->rx.state == ISOTP_WAIT_DATA) {
169 /* we did not get new data frames in time */
171 /* report 'connection timed out' */
172 sk->sk_err = ETIMEDOUT;
173 if (!sock_flag(sk, SOCK_DEAD))
177 so->rx.state = ISOTP_IDLE;
180 return HRTIMER_NORESTART;
183 static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
185 struct net_device *dev;
186 struct sk_buff *nskb;
187 struct canfd_frame *ncf;
188 struct isotp_sock *so = isotp_sk(sk);
191 nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
195 dev = dev_get_by_index(sock_net(sk), so->ifindex);
201 can_skb_reserve(nskb);
202 can_skb_prv(nskb)->ifindex = dev->ifindex;
203 can_skb_prv(nskb)->skbcnt = 0;
206 can_skb_set_owner(nskb, sk);
207 ncf = (struct canfd_frame *)nskb->data;
208 skb_put_zero(nskb, so->ll.mtu);
210 /* create & send flow control reply */
211 ncf->can_id = so->txid;
213 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
214 memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
215 ncf->len = CAN_MAX_DLEN;
217 ncf->len = ae + FC_CONTENT_SZ;
220 ncf->data[ae] = N_PCI_FC | flowstatus;
221 ncf->data[ae + 1] = so->rxfc.bs;
222 ncf->data[ae + 2] = so->rxfc.stmin;
225 ncf->data[0] = so->opt.ext_address;
227 ncf->flags = so->ll.tx_flags;
229 can_send_ret = can_send(nskb, 1);
231 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
232 __func__, ERR_PTR(can_send_ret));
236 /* reset blocksize counter */
239 /* reset last CF frame rx timestamp for rx stmin enforcement */
240 so->lastrxcf_tstamp = ktime_set(0, 0);
242 /* start rx timeout watchdog */
243 hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
247 static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
249 struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
251 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
253 memset(addr, 0, sizeof(*addr));
254 addr->can_family = AF_CAN;
255 addr->can_ifindex = skb->dev->ifindex;
257 if (sock_queue_rcv_skb(sk, skb) < 0)
261 static u8 padlen(u8 datalen)
263 static const u8 plen[] = {
264 8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
265 12, 12, 12, 12, /* 9 - 12 */
266 16, 16, 16, 16, /* 13 - 16 */
267 20, 20, 20, 20, /* 17 - 20 */
268 24, 24, 24, 24, /* 21 - 24 */
269 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
270 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
271 48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
277 return plen[datalen];
280 /* check for length optimization and return 1/true when the check fails */
281 static int check_optimized(struct canfd_frame *cf, int start_index)
283 /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
284 * padding would start at this point. E.g. if the padding would
285 * start at cf.data[7] cf->len has to be 7 to be optimal.
286 * Note: The data[] index starts with zero.
288 if (cf->len <= CAN_MAX_DLEN)
289 return (cf->len != start_index);
291 /* This relation is also valid in the non-linear DLC range, where
292 * we need to take care of the minimal next possible CAN_DL.
293 * The correct check would be (padlen(cf->len) != padlen(start_index)).
294 * But as cf->len can only take discrete values from 12, .., 64 at this
295 * point the padlen(cf->len) is always equal to cf->len.
297 return (cf->len != padlen(start_index));
300 /* check padding and return 1/true when the check fails */
301 static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
302 int start_index, u8 content)
306 /* no RX_PADDING value => check length of optimized frame length */
307 if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
308 if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
309 return check_optimized(cf, start_index);
311 /* no valid test against empty value => ignore frame */
315 /* check datalength of correctly padded CAN frame */
316 if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
317 cf->len != padlen(cf->len))
320 /* check padding content */
321 if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
322 for (i = start_index; i < cf->len; i++)
323 if (cf->data[i] != content)
329 static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
331 struct sock *sk = &so->sk;
333 if (so->tx.state != ISOTP_WAIT_FC &&
334 so->tx.state != ISOTP_WAIT_FIRST_FC)
337 hrtimer_cancel(&so->txtimer);
339 if ((cf->len < ae + FC_CONTENT_SZ) ||
340 ((so->opt.flags & ISOTP_CHECK_PADDING) &&
341 check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
342 /* malformed PDU - report 'not a data message' */
343 sk->sk_err = EBADMSG;
344 if (!sock_flag(sk, SOCK_DEAD))
347 so->tx.state = ISOTP_IDLE;
348 wake_up_interruptible(&so->wait);
352 /* get communication parameters only from the first FC frame */
353 if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
354 so->txfc.bs = cf->data[ae + 1];
355 so->txfc.stmin = cf->data[ae + 2];
357 /* fix wrong STmin values according spec */
358 if (so->txfc.stmin > 0x7F &&
359 (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
360 so->txfc.stmin = 0x7F;
362 so->tx_gap = ktime_set(0, 0);
363 /* add transmission time for CAN frame N_As */
364 so->tx_gap = ktime_add_ns(so->tx_gap, so->frame_txtime);
365 /* add waiting time for consecutive frames N_Cs */
366 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
367 so->tx_gap = ktime_add_ns(so->tx_gap,
369 else if (so->txfc.stmin < 0x80)
370 so->tx_gap = ktime_add_ns(so->tx_gap,
371 so->txfc.stmin * 1000000);
373 so->tx_gap = ktime_add_ns(so->tx_gap,
374 (so->txfc.stmin - 0xF0)
376 so->tx.state = ISOTP_WAIT_FC;
379 switch (cf->data[ae] & 0x0F) {
382 so->tx.state = ISOTP_SENDING;
383 /* start cyclic timer for sending CF frame */
384 hrtimer_start(&so->txtimer, so->tx_gap,
385 HRTIMER_MODE_REL_SOFT);
389 /* start timer to wait for next FC frame */
390 hrtimer_start(&so->txtimer, ktime_set(1, 0),
391 HRTIMER_MODE_REL_SOFT);
395 /* overflow on receiver side - report 'message too long' */
396 sk->sk_err = EMSGSIZE;
397 if (!sock_flag(sk, SOCK_DEAD))
402 /* stop this tx job */
403 so->tx.state = ISOTP_IDLE;
404 wake_up_interruptible(&so->wait);
409 static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
410 struct sk_buff *skb, int len)
412 struct isotp_sock *so = isotp_sk(sk);
413 struct sk_buff *nskb;
415 hrtimer_cancel(&so->rxtimer);
416 so->rx.state = ISOTP_IDLE;
418 if (!len || len > cf->len - pcilen)
421 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
422 check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
423 /* malformed PDU - report 'not a data message' */
424 sk->sk_err = EBADMSG;
425 if (!sock_flag(sk, SOCK_DEAD))
430 nskb = alloc_skb(len, gfp_any());
434 memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
436 nskb->tstamp = skb->tstamp;
437 nskb->dev = skb->dev;
438 isotp_rcv_skb(nskb, sk);
442 static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
444 struct isotp_sock *so = isotp_sk(sk);
449 hrtimer_cancel(&so->rxtimer);
450 so->rx.state = ISOTP_IDLE;
452 /* get the used sender LL_DL from the (first) CAN frame data length */
453 so->rx.ll_dl = padlen(cf->len);
455 /* the first frame has to use the entire frame up to LL_DL length */
456 if (cf->len != so->rx.ll_dl)
460 so->rx.len = (cf->data[ae] & 0x0F) << 8;
461 so->rx.len += cf->data[ae + 1];
463 /* Check for FF_DL escape sequence supporting 32 bit PDU length */
465 ff_pci_sz = FF_PCI_SZ12;
467 /* FF_DL = 0 => get real length from next 4 bytes */
468 so->rx.len = cf->data[ae + 2] << 24;
469 so->rx.len += cf->data[ae + 3] << 16;
470 so->rx.len += cf->data[ae + 4] << 8;
471 so->rx.len += cf->data[ae + 5];
472 ff_pci_sz = FF_PCI_SZ32;
475 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
476 off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
478 if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
481 if (so->rx.len > MAX_MSG_LENGTH) {
482 /* send FC frame with overflow status */
483 isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
487 /* copy the first received data bytes */
489 for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
490 so->rx.buf[so->rx.idx++] = cf->data[i];
492 /* initial setup for this pdu reception */
494 so->rx.state = ISOTP_WAIT_DATA;
496 /* no creation of flow control frames */
497 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
500 /* send our first FC frame */
501 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
505 static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
508 struct isotp_sock *so = isotp_sk(sk);
509 struct sk_buff *nskb;
512 if (so->rx.state != ISOTP_WAIT_DATA)
515 /* drop if timestamp gap is less than force_rx_stmin nano secs */
516 if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
517 if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
521 so->lastrxcf_tstamp = skb->tstamp;
524 hrtimer_cancel(&so->rxtimer);
526 /* CFs are never longer than the FF */
527 if (cf->len > so->rx.ll_dl)
530 /* CFs have usually the LL_DL length */
531 if (cf->len < so->rx.ll_dl) {
532 /* this is only allowed for the last CF */
533 if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
537 if ((cf->data[ae] & 0x0F) != so->rx.sn) {
538 /* wrong sn detected - report 'illegal byte sequence' */
540 if (!sock_flag(sk, SOCK_DEAD))
544 so->rx.state = ISOTP_IDLE;
550 for (i = ae + N_PCI_SZ; i < cf->len; i++) {
551 so->rx.buf[so->rx.idx++] = cf->data[i];
552 if (so->rx.idx >= so->rx.len)
556 if (so->rx.idx >= so->rx.len) {
558 so->rx.state = ISOTP_IDLE;
560 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
561 check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
562 /* malformed PDU - report 'not a data message' */
563 sk->sk_err = EBADMSG;
564 if (!sock_flag(sk, SOCK_DEAD))
569 nskb = alloc_skb(so->rx.len, gfp_any());
573 memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
576 nskb->tstamp = skb->tstamp;
577 nskb->dev = skb->dev;
578 isotp_rcv_skb(nskb, sk);
582 /* perform blocksize handling, if enabled */
583 if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
584 /* start rx timeout watchdog */
585 hrtimer_start(&so->rxtimer, ktime_set(1, 0),
586 HRTIMER_MODE_REL_SOFT);
590 /* no creation of flow control frames */
591 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
594 /* we reached the specified blocksize so->rxfc.bs */
595 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
599 static void isotp_rcv(struct sk_buff *skb, void *data)
601 struct sock *sk = (struct sock *)data;
602 struct isotp_sock *so = isotp_sk(sk);
603 struct canfd_frame *cf;
604 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
605 u8 n_pci_type, sf_dl;
607 /* Strictly receive only frames with the configured MTU size
608 * => clear separation of CAN2.0 / CAN FD transport channels
610 if (skb->len != so->ll.mtu)
613 cf = (struct canfd_frame *)skb->data;
615 /* if enabled: check reception of my configured extended address */
616 if (ae && cf->data[0] != so->opt.rx_ext_address)
619 n_pci_type = cf->data[ae] & 0xF0;
621 /* Make sure the state changes and data structures stay consistent at
622 * CAN frame reception time. This locking is not needed in real world
623 * use cases but the inconsistency can be triggered with syzkaller.
625 spin_lock(&so->rx_lock);
627 if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
628 /* check rx/tx path half duplex expectations */
629 if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
630 (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
634 switch (n_pci_type) {
636 /* tx path: flow control frame containing the FC parameters */
637 isotp_rcv_fc(so, cf, ae);
641 /* rx path: single frame
643 * As we do not have a rx.ll_dl configuration, we can only test
644 * if the CAN frames payload length matches the LL_DL == 8
645 * requirements - no matter if it's CAN 2.0 or CAN FD
648 /* get the SF_DL from the N_PCI byte */
649 sf_dl = cf->data[ae] & 0x0F;
651 if (cf->len <= CAN_MAX_DLEN) {
652 isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
654 if (skb->len == CANFD_MTU) {
655 /* We have a CAN FD frame and CAN_DL is greater than 8:
656 * Only frames with the SF_DL == 0 ESC value are valid.
658 * If so take care of the increased SF PCI size
659 * (SF_PCI_SZ8) to point to the message content behind
660 * the extended SF PCI info and get the real SF_DL
661 * length value from the formerly first data byte.
664 isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
665 cf->data[SF_PCI_SZ4 + ae]);
671 /* rx path: first frame */
672 isotp_rcv_ff(sk, cf, ae);
676 /* rx path: consecutive frame */
677 isotp_rcv_cf(sk, cf, ae, skb);
682 spin_unlock(&so->rx_lock);
685 static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
688 int pcilen = N_PCI_SZ + ae + off;
689 int space = so->tx.ll_dl - pcilen;
690 int num = min_t(int, so->tx.len - so->tx.idx, space);
693 cf->can_id = so->txid;
694 cf->len = num + pcilen;
697 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
698 /* user requested padding */
699 cf->len = padlen(cf->len);
700 memset(cf->data, so->opt.txpad_content, cf->len);
701 } else if (cf->len > CAN_MAX_DLEN) {
702 /* mandatory padding for CAN FD frames */
703 cf->len = padlen(cf->len);
704 memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
709 for (i = 0; i < num; i++)
710 cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
713 cf->data[0] = so->opt.ext_address;
716 static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
722 cf->can_id = so->txid;
723 cf->len = so->tx.ll_dl;
725 cf->data[0] = so->opt.ext_address;
727 /* create N_PCI bytes with 12/32 bit FF_DL data length */
728 if (so->tx.len > 4095) {
729 /* use 32 bit FF_DL notation */
730 cf->data[ae] = N_PCI_FF;
731 cf->data[ae + 1] = 0;
732 cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
733 cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
734 cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
735 cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
736 ff_pci_sz = FF_PCI_SZ32;
738 /* use 12 bit FF_DL notation */
739 cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
740 cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
741 ff_pci_sz = FF_PCI_SZ12;
744 /* add first data bytes depending on ae */
745 for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
746 cf->data[i] = so->tx.buf[so->tx.idx++];
749 so->tx.state = ISOTP_WAIT_FIRST_FC;
752 static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
754 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
756 struct sock *sk = &so->sk;
758 struct net_device *dev;
759 struct canfd_frame *cf;
760 enum hrtimer_restart restart = HRTIMER_NORESTART;
762 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
764 switch (so->tx.state) {
766 case ISOTP_WAIT_FIRST_FC:
768 /* we did not get any flow control frame in time */
770 /* report 'communication error on send' */
772 if (!sock_flag(sk, SOCK_DEAD))
776 so->tx.state = ISOTP_IDLE;
777 wake_up_interruptible(&so->wait);
782 /* push out the next segmented pdu */
783 dev = dev_get_by_index(sock_net(sk), so->ifindex);
788 skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
795 can_skb_reserve(skb);
796 can_skb_prv(skb)->ifindex = dev->ifindex;
797 can_skb_prv(skb)->skbcnt = 0;
799 cf = (struct canfd_frame *)skb->data;
800 skb_put_zero(skb, so->ll.mtu);
802 /* create consecutive frame */
803 isotp_fill_dataframe(cf, so, ae, 0);
805 /* place consecutive frame N_PCI in appropriate index */
806 cf->data[ae] = N_PCI_CF | so->tx.sn++;
810 cf->flags = so->ll.tx_flags;
813 can_skb_set_owner(skb, sk);
815 can_send_ret = can_send(skb, 1);
817 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
818 __func__, ERR_PTR(can_send_ret));
819 if (can_send_ret == -ENOBUFS)
820 pr_notice_once("can-isotp: tx queue is full, increasing txqueuelen may prevent this error\n");
822 if (so->tx.idx >= so->tx.len) {
824 so->tx.state = ISOTP_IDLE;
826 wake_up_interruptible(&so->wait);
830 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
831 /* stop and wait for FC */
832 so->tx.state = ISOTP_WAIT_FC;
834 hrtimer_set_expires(&so->txtimer,
835 ktime_add(ktime_get(),
837 restart = HRTIMER_RESTART;
841 /* no gap between data frames needed => use burst mode */
845 /* start timer to send next data frame with correct delay */
847 hrtimer_set_expires(&so->txtimer,
848 ktime_add(ktime_get(), so->tx_gap));
849 restart = HRTIMER_RESTART;
859 static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
861 struct sock *sk = sock->sk;
862 struct isotp_sock *so = isotp_sk(sk);
863 u32 old_state = so->tx.state;
865 struct net_device *dev;
866 struct canfd_frame *cf;
867 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
868 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
874 return -EADDRNOTAVAIL;
876 /* we do not support multiple buffers - for now */
877 if (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE ||
878 wq_has_sleeper(&so->wait)) {
879 if (msg->msg_flags & MSG_DONTWAIT) {
884 /* wait for complete transmission of current pdu */
885 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
890 if (!size || size > MAX_MSG_LENGTH) {
895 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
896 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
898 /* does the given data fit into a single frame for SF_BROADCAST? */
899 if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) &&
900 (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
905 err = memcpy_from_msg(so->tx.buf, msg, size);
909 dev = dev_get_by_index(sock_net(sk), so->ifindex);
915 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
916 msg->msg_flags & MSG_DONTWAIT, &err);
922 can_skb_reserve(skb);
923 can_skb_prv(skb)->ifindex = dev->ifindex;
924 can_skb_prv(skb)->skbcnt = 0;
929 cf = (struct canfd_frame *)skb->data;
930 skb_put_zero(skb, so->ll.mtu);
932 /* check for single frame transmission depending on TX_DL */
933 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
934 /* The message size generally fits into a SingleFrame - good.
936 * SF_DL ESC offset optimization:
938 * When TX_DL is greater 8 but the message would still fit
939 * into a 8 byte CAN frame, we can omit the offset.
940 * This prevents a protocol caused length extension from
941 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
943 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
946 isotp_fill_dataframe(cf, so, ae, off);
948 /* place single frame N_PCI w/o length in appropriate index */
949 cf->data[ae] = N_PCI_SF;
951 /* place SF_DL size value depending on the SF_DL ESC offset */
953 cf->data[SF_PCI_SZ4 + ae] = size;
955 cf->data[ae] |= size;
957 so->tx.state = ISOTP_IDLE;
958 wake_up_interruptible(&so->wait);
960 /* don't enable wait queue for a single frame transmission */
963 /* send first frame and wait for FC */
965 isotp_create_fframe(cf, so, ae);
967 /* start timeout for FC */
969 hrtimer_start(&so->txtimer, ktime_set(hrtimer_sec, 0),
970 HRTIMER_MODE_REL_SOFT);
973 /* send the first or only CAN frame */
974 cf->flags = so->ll.tx_flags;
978 err = can_send(skb, 1);
981 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
982 __func__, ERR_PTR(err));
984 /* no transmission -> no timeout monitoring */
986 hrtimer_cancel(&so->txtimer);
992 /* wait for complete transmission of current pdu */
993 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
995 err = sock_error(sk);
1003 /* drop this PDU and unlock a potential wait queue */
1004 old_state = ISOTP_IDLE;
1006 so->tx.state = old_state;
1007 if (so->tx.state == ISOTP_IDLE)
1008 wake_up_interruptible(&so->wait);
1013 static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1016 struct sock *sk = sock->sk;
1017 struct sk_buff *skb;
1018 struct isotp_sock *so = isotp_sk(sk);
1019 int noblock = flags & MSG_DONTWAIT;
1022 if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK | MSG_CMSG_COMPAT))
1026 return -EADDRNOTAVAIL;
1028 flags &= ~MSG_DONTWAIT;
1029 skb = skb_recv_datagram(sk, flags, noblock, &ret);
1033 if (size < skb->len)
1034 msg->msg_flags |= MSG_TRUNC;
1038 ret = memcpy_to_msg(msg, skb->data, size);
1042 sock_recv_timestamp(msg, sk, skb);
1044 if (msg->msg_name) {
1045 __sockaddr_check_size(ISOTP_MIN_NAMELEN);
1046 msg->msg_namelen = ISOTP_MIN_NAMELEN;
1047 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1050 /* set length of return value */
1051 ret = (flags & MSG_TRUNC) ? skb->len : size;
1054 skb_free_datagram(sk, skb);
1059 static int isotp_release(struct socket *sock)
1061 struct sock *sk = sock->sk;
1062 struct isotp_sock *so;
1071 /* wait for complete transmission of current pdu */
1072 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1074 spin_lock(&isotp_notifier_lock);
1075 while (isotp_busy_notifier == so) {
1076 spin_unlock(&isotp_notifier_lock);
1077 schedule_timeout_uninterruptible(1);
1078 spin_lock(&isotp_notifier_lock);
1080 list_del(&so->notifier);
1081 spin_unlock(&isotp_notifier_lock);
1085 /* remove current filters & unregister */
1086 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) {
1088 struct net_device *dev;
1090 dev = dev_get_by_index(net, so->ifindex);
1092 can_rx_unregister(net, dev, so->rxid,
1093 SINGLE_MASK(so->rxid),
1101 hrtimer_cancel(&so->txtimer);
1102 hrtimer_cancel(&so->rxtimer);
1116 static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1118 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1119 struct sock *sk = sock->sk;
1120 struct isotp_sock *so = isotp_sk(sk);
1121 struct net *net = sock_net(sk);
1123 struct net_device *dev;
1124 canid_t tx_id, rx_id;
1126 int notify_enetdown = 0;
1129 if (len < ISOTP_MIN_NAMELEN)
1132 /* sanitize tx/rx CAN identifiers */
1133 tx_id = addr->can_addr.tp.tx_id;
1134 if (tx_id & CAN_EFF_FLAG)
1135 tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1137 tx_id &= CAN_SFF_MASK;
1139 rx_id = addr->can_addr.tp.rx_id;
1140 if (rx_id & CAN_EFF_FLAG)
1141 rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
1143 rx_id &= CAN_SFF_MASK;
1145 if (!addr->can_ifindex)
1155 /* do not register frame reception for functional addressing */
1156 if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
1159 /* do not validate rx address for functional addressing */
1160 if (do_rx_reg && rx_id == tx_id) {
1161 err = -EADDRNOTAVAIL;
1165 dev = dev_get_by_index(net, addr->can_ifindex);
1170 if (dev->type != ARPHRD_CAN) {
1175 if (dev->mtu < so->ll.mtu) {
1180 if (!(dev->flags & IFF_UP))
1181 notify_enetdown = 1;
1183 ifindex = dev->ifindex;
1186 can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
1187 isotp_rcv, sk, "isotp", sk);
1191 /* switch to new settings */
1192 so->ifindex = ifindex;
1200 if (notify_enetdown) {
1201 sk->sk_err = ENETDOWN;
1202 if (!sock_flag(sk, SOCK_DEAD))
1203 sk_error_report(sk);
1209 static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1211 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1212 struct sock *sk = sock->sk;
1213 struct isotp_sock *so = isotp_sk(sk);
1218 memset(addr, 0, ISOTP_MIN_NAMELEN);
1219 addr->can_family = AF_CAN;
1220 addr->can_ifindex = so->ifindex;
1221 addr->can_addr.tp.rx_id = so->rxid;
1222 addr->can_addr.tp.tx_id = so->txid;
1224 return ISOTP_MIN_NAMELEN;
1227 static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
1228 sockptr_t optval, unsigned int optlen)
1230 struct sock *sk = sock->sk;
1231 struct isotp_sock *so = isotp_sk(sk);
1238 case CAN_ISOTP_OPTS:
1239 if (optlen != sizeof(struct can_isotp_options))
1242 if (copy_from_sockptr(&so->opt, optval, optlen))
1245 /* no separate rx_ext_address is given => use ext_address */
1246 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1247 so->opt.rx_ext_address = so->opt.ext_address;
1249 /* check for frame_txtime changes (0 => no changes) */
1250 if (so->opt.frame_txtime) {
1251 if (so->opt.frame_txtime == CAN_ISOTP_FRAME_TXTIME_ZERO)
1252 so->frame_txtime = 0;
1254 so->frame_txtime = so->opt.frame_txtime;
1258 case CAN_ISOTP_RECV_FC:
1259 if (optlen != sizeof(struct can_isotp_fc_options))
1262 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1266 case CAN_ISOTP_TX_STMIN:
1267 if (optlen != sizeof(u32))
1270 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1274 case CAN_ISOTP_RX_STMIN:
1275 if (optlen != sizeof(u32))
1278 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1282 case CAN_ISOTP_LL_OPTS:
1283 if (optlen == sizeof(struct can_isotp_ll_options)) {
1284 struct can_isotp_ll_options ll;
1286 if (copy_from_sockptr(&ll, optval, optlen))
1289 /* check for correct ISO 11898-1 DLC data length */
1290 if (ll.tx_dl != padlen(ll.tx_dl))
1293 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1296 if (ll.mtu == CAN_MTU &&
1297 (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1300 memcpy(&so->ll, &ll, sizeof(ll));
1302 /* set ll_dl for tx path to similar place as for rx */
1303 so->tx.ll_dl = ll.tx_dl;
1316 static int isotp_setsockopt(struct socket *sock, int level, int optname,
1317 sockptr_t optval, unsigned int optlen)
1320 struct sock *sk = sock->sk;
1323 if (level != SOL_CAN_ISOTP)
1327 ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
1332 static int isotp_getsockopt(struct socket *sock, int level, int optname,
1333 char __user *optval, int __user *optlen)
1335 struct sock *sk = sock->sk;
1336 struct isotp_sock *so = isotp_sk(sk);
1340 if (level != SOL_CAN_ISOTP)
1342 if (get_user(len, optlen))
1348 case CAN_ISOTP_OPTS:
1349 len = min_t(int, len, sizeof(struct can_isotp_options));
1353 case CAN_ISOTP_RECV_FC:
1354 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1358 case CAN_ISOTP_TX_STMIN:
1359 len = min_t(int, len, sizeof(u32));
1360 val = &so->force_tx_stmin;
1363 case CAN_ISOTP_RX_STMIN:
1364 len = min_t(int, len, sizeof(u32));
1365 val = &so->force_rx_stmin;
1368 case CAN_ISOTP_LL_OPTS:
1369 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1374 return -ENOPROTOOPT;
1377 if (put_user(len, optlen))
1379 if (copy_to_user(optval, val, len))
1384 static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1385 struct net_device *dev)
1387 struct sock *sk = &so->sk;
1389 if (!net_eq(dev_net(dev), sock_net(sk)))
1392 if (so->ifindex != dev->ifindex)
1396 case NETDEV_UNREGISTER:
1398 /* remove current filters & unregister */
1399 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))
1400 can_rx_unregister(dev_net(dev), dev, so->rxid,
1401 SINGLE_MASK(so->rxid),
1408 sk->sk_err = ENODEV;
1409 if (!sock_flag(sk, SOCK_DEAD))
1410 sk_error_report(sk);
1414 sk->sk_err = ENETDOWN;
1415 if (!sock_flag(sk, SOCK_DEAD))
1416 sk_error_report(sk);
1421 static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1424 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1426 if (dev->type != ARPHRD_CAN)
1428 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1430 if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1433 spin_lock(&isotp_notifier_lock);
1434 list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1435 spin_unlock(&isotp_notifier_lock);
1436 isotp_notify(isotp_busy_notifier, msg, dev);
1437 spin_lock(&isotp_notifier_lock);
1439 isotp_busy_notifier = NULL;
1440 spin_unlock(&isotp_notifier_lock);
1444 static int isotp_init(struct sock *sk)
1446 struct isotp_sock *so = isotp_sk(sk);
1451 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1452 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1453 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1454 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1455 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1456 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1457 so->frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1458 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1459 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1460 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1461 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1462 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1463 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1465 /* set ll_dl for tx path to similar place as for rx */
1466 so->tx.ll_dl = so->ll.tx_dl;
1468 so->rx.state = ISOTP_IDLE;
1469 so->tx.state = ISOTP_IDLE;
1471 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1472 so->rxtimer.function = isotp_rx_timer_handler;
1473 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1474 so->txtimer.function = isotp_tx_timer_handler;
1476 init_waitqueue_head(&so->wait);
1477 spin_lock_init(&so->rx_lock);
1479 spin_lock(&isotp_notifier_lock);
1480 list_add_tail(&so->notifier, &isotp_notifier_list);
1481 spin_unlock(&isotp_notifier_lock);
1486 static __poll_t isotp_poll(struct file *file, struct socket *sock, poll_table *wait)
1488 struct sock *sk = sock->sk;
1489 struct isotp_sock *so = isotp_sk(sk);
1491 __poll_t mask = datagram_poll(file, sock, wait);
1492 poll_wait(file, &so->wait, wait);
1494 /* Check for false positives due to TX state */
1495 if ((mask & EPOLLWRNORM) && (so->tx.state != ISOTP_IDLE))
1496 mask &= ~(EPOLLOUT | EPOLLWRNORM);
1501 static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1504 /* no ioctls for socket layer -> hand it down to NIC layer */
1505 return -ENOIOCTLCMD;
1508 static const struct proto_ops isotp_ops = {
1510 .release = isotp_release,
1512 .connect = sock_no_connect,
1513 .socketpair = sock_no_socketpair,
1514 .accept = sock_no_accept,
1515 .getname = isotp_getname,
1517 .ioctl = isotp_sock_no_ioctlcmd,
1518 .gettstamp = sock_gettstamp,
1519 .listen = sock_no_listen,
1520 .shutdown = sock_no_shutdown,
1521 .setsockopt = isotp_setsockopt,
1522 .getsockopt = isotp_getsockopt,
1523 .sendmsg = isotp_sendmsg,
1524 .recvmsg = isotp_recvmsg,
1525 .mmap = sock_no_mmap,
1526 .sendpage = sock_no_sendpage,
1529 static struct proto isotp_proto __read_mostly = {
1530 .name = "CAN_ISOTP",
1531 .owner = THIS_MODULE,
1532 .obj_size = sizeof(struct isotp_sock),
1536 static const struct can_proto isotp_can_proto = {
1538 .protocol = CAN_ISOTP,
1540 .prot = &isotp_proto,
1543 static struct notifier_block canisotp_notifier = {
1544 .notifier_call = isotp_notifier
1547 static __init int isotp_module_init(void)
1551 pr_info("can: isotp protocol\n");
1553 err = can_proto_register(&isotp_can_proto);
1555 pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
1557 register_netdevice_notifier(&canisotp_notifier);
1562 static __exit void isotp_module_exit(void)
1564 can_proto_unregister(&isotp_can_proto);
1565 unregister_netdevice_notifier(&canisotp_notifier);
1568 module_init(isotp_module_init);
1569 module_exit(isotp_module_exit);