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;
147 struct list_head notifier;
148 wait_queue_head_t wait;
149 spinlock_t rx_lock; /* protect single thread state machine */
152 static LIST_HEAD(isotp_notifier_list);
153 static DEFINE_SPINLOCK(isotp_notifier_lock);
154 static struct isotp_sock *isotp_busy_notifier;
156 static inline struct isotp_sock *isotp_sk(const struct sock *sk)
158 return (struct isotp_sock *)sk;
161 static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
163 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
165 struct sock *sk = &so->sk;
167 if (so->rx.state == ISOTP_WAIT_DATA) {
168 /* we did not get new data frames in time */
170 /* report 'connection timed out' */
171 sk->sk_err = ETIMEDOUT;
172 if (!sock_flag(sk, SOCK_DEAD))
176 so->rx.state = ISOTP_IDLE;
179 return HRTIMER_NORESTART;
182 static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
184 struct net_device *dev;
185 struct sk_buff *nskb;
186 struct canfd_frame *ncf;
187 struct isotp_sock *so = isotp_sk(sk);
190 nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
194 dev = dev_get_by_index(sock_net(sk), so->ifindex);
200 can_skb_reserve(nskb);
201 can_skb_prv(nskb)->ifindex = dev->ifindex;
202 can_skb_prv(nskb)->skbcnt = 0;
205 can_skb_set_owner(nskb, sk);
206 ncf = (struct canfd_frame *)nskb->data;
207 skb_put_zero(nskb, so->ll.mtu);
209 /* create & send flow control reply */
210 ncf->can_id = so->txid;
212 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
213 memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
214 ncf->len = CAN_MAX_DLEN;
216 ncf->len = ae + FC_CONTENT_SZ;
219 ncf->data[ae] = N_PCI_FC | flowstatus;
220 ncf->data[ae + 1] = so->rxfc.bs;
221 ncf->data[ae + 2] = so->rxfc.stmin;
224 ncf->data[0] = so->opt.ext_address;
226 ncf->flags = so->ll.tx_flags;
228 can_send_ret = can_send(nskb, 1);
230 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
231 __func__, ERR_PTR(can_send_ret));
235 /* reset blocksize counter */
238 /* reset last CF frame rx timestamp for rx stmin enforcement */
239 so->lastrxcf_tstamp = ktime_set(0, 0);
241 /* start rx timeout watchdog */
242 hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
246 static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
248 struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
250 BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
252 memset(addr, 0, sizeof(*addr));
253 addr->can_family = AF_CAN;
254 addr->can_ifindex = skb->dev->ifindex;
256 if (sock_queue_rcv_skb(sk, skb) < 0)
260 static u8 padlen(u8 datalen)
262 static const u8 plen[] = {
263 8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
264 12, 12, 12, 12, /* 9 - 12 */
265 16, 16, 16, 16, /* 13 - 16 */
266 20, 20, 20, 20, /* 17 - 20 */
267 24, 24, 24, 24, /* 21 - 24 */
268 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
269 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
270 48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
276 return plen[datalen];
279 /* check for length optimization and return 1/true when the check fails */
280 static int check_optimized(struct canfd_frame *cf, int start_index)
282 /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
283 * padding would start at this point. E.g. if the padding would
284 * start at cf.data[7] cf->len has to be 7 to be optimal.
285 * Note: The data[] index starts with zero.
287 if (cf->len <= CAN_MAX_DLEN)
288 return (cf->len != start_index);
290 /* This relation is also valid in the non-linear DLC range, where
291 * we need to take care of the minimal next possible CAN_DL.
292 * The correct check would be (padlen(cf->len) != padlen(start_index)).
293 * But as cf->len can only take discrete values from 12, .., 64 at this
294 * point the padlen(cf->len) is always equal to cf->len.
296 return (cf->len != padlen(start_index));
299 /* check padding and return 1/true when the check fails */
300 static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
301 int start_index, u8 content)
305 /* no RX_PADDING value => check length of optimized frame length */
306 if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
307 if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
308 return check_optimized(cf, start_index);
310 /* no valid test against empty value => ignore frame */
314 /* check datalength of correctly padded CAN frame */
315 if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
316 cf->len != padlen(cf->len))
319 /* check padding content */
320 if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
321 for (i = start_index; i < cf->len; i++)
322 if (cf->data[i] != content)
328 static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
330 struct sock *sk = &so->sk;
332 if (so->tx.state != ISOTP_WAIT_FC &&
333 so->tx.state != ISOTP_WAIT_FIRST_FC)
336 hrtimer_cancel(&so->txtimer);
338 if ((cf->len < ae + FC_CONTENT_SZ) ||
339 ((so->opt.flags & ISOTP_CHECK_PADDING) &&
340 check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
341 /* malformed PDU - report 'not a data message' */
342 sk->sk_err = EBADMSG;
343 if (!sock_flag(sk, SOCK_DEAD))
346 so->tx.state = ISOTP_IDLE;
347 wake_up_interruptible(&so->wait);
351 /* get communication parameters only from the first FC frame */
352 if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
353 so->txfc.bs = cf->data[ae + 1];
354 so->txfc.stmin = cf->data[ae + 2];
356 /* fix wrong STmin values according spec */
357 if (so->txfc.stmin > 0x7F &&
358 (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
359 so->txfc.stmin = 0x7F;
361 so->tx_gap = ktime_set(0, 0);
362 /* add transmission time for CAN frame N_As */
363 so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
364 /* add waiting time for consecutive frames N_Cs */
365 if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
366 so->tx_gap = ktime_add_ns(so->tx_gap,
368 else if (so->txfc.stmin < 0x80)
369 so->tx_gap = ktime_add_ns(so->tx_gap,
370 so->txfc.stmin * 1000000);
372 so->tx_gap = ktime_add_ns(so->tx_gap,
373 (so->txfc.stmin - 0xF0)
375 so->tx.state = ISOTP_WAIT_FC;
378 switch (cf->data[ae] & 0x0F) {
381 so->tx.state = ISOTP_SENDING;
382 /* start cyclic timer for sending CF frame */
383 hrtimer_start(&so->txtimer, so->tx_gap,
384 HRTIMER_MODE_REL_SOFT);
388 /* start timer to wait for next FC frame */
389 hrtimer_start(&so->txtimer, ktime_set(1, 0),
390 HRTIMER_MODE_REL_SOFT);
394 /* overflow on receiver side - report 'message too long' */
395 sk->sk_err = EMSGSIZE;
396 if (!sock_flag(sk, SOCK_DEAD))
401 /* stop this tx job */
402 so->tx.state = ISOTP_IDLE;
403 wake_up_interruptible(&so->wait);
408 static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
409 struct sk_buff *skb, int len)
411 struct isotp_sock *so = isotp_sk(sk);
412 struct sk_buff *nskb;
414 hrtimer_cancel(&so->rxtimer);
415 so->rx.state = ISOTP_IDLE;
417 if (!len || len > cf->len - pcilen)
420 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
421 check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
422 /* malformed PDU - report 'not a data message' */
423 sk->sk_err = EBADMSG;
424 if (!sock_flag(sk, SOCK_DEAD))
429 nskb = alloc_skb(len, gfp_any());
433 memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
435 nskb->tstamp = skb->tstamp;
436 nskb->dev = skb->dev;
437 isotp_rcv_skb(nskb, sk);
441 static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
443 struct isotp_sock *so = isotp_sk(sk);
448 hrtimer_cancel(&so->rxtimer);
449 so->rx.state = ISOTP_IDLE;
451 /* get the used sender LL_DL from the (first) CAN frame data length */
452 so->rx.ll_dl = padlen(cf->len);
454 /* the first frame has to use the entire frame up to LL_DL length */
455 if (cf->len != so->rx.ll_dl)
459 so->rx.len = (cf->data[ae] & 0x0F) << 8;
460 so->rx.len += cf->data[ae + 1];
462 /* Check for FF_DL escape sequence supporting 32 bit PDU length */
464 ff_pci_sz = FF_PCI_SZ12;
466 /* FF_DL = 0 => get real length from next 4 bytes */
467 so->rx.len = cf->data[ae + 2] << 24;
468 so->rx.len += cf->data[ae + 3] << 16;
469 so->rx.len += cf->data[ae + 4] << 8;
470 so->rx.len += cf->data[ae + 5];
471 ff_pci_sz = FF_PCI_SZ32;
474 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
475 off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
477 if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
480 if (so->rx.len > MAX_MSG_LENGTH) {
481 /* send FC frame with overflow status */
482 isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
486 /* copy the first received data bytes */
488 for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
489 so->rx.buf[so->rx.idx++] = cf->data[i];
491 /* initial setup for this pdu reception */
493 so->rx.state = ISOTP_WAIT_DATA;
495 /* no creation of flow control frames */
496 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
499 /* send our first FC frame */
500 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
504 static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
507 struct isotp_sock *so = isotp_sk(sk);
508 struct sk_buff *nskb;
511 if (so->rx.state != ISOTP_WAIT_DATA)
514 /* drop if timestamp gap is less than force_rx_stmin nano secs */
515 if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
516 if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
520 so->lastrxcf_tstamp = skb->tstamp;
523 hrtimer_cancel(&so->rxtimer);
525 /* CFs are never longer than the FF */
526 if (cf->len > so->rx.ll_dl)
529 /* CFs have usually the LL_DL length */
530 if (cf->len < so->rx.ll_dl) {
531 /* this is only allowed for the last CF */
532 if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
536 if ((cf->data[ae] & 0x0F) != so->rx.sn) {
537 /* wrong sn detected - report 'illegal byte sequence' */
539 if (!sock_flag(sk, SOCK_DEAD))
543 so->rx.state = ISOTP_IDLE;
549 for (i = ae + N_PCI_SZ; i < cf->len; i++) {
550 so->rx.buf[so->rx.idx++] = cf->data[i];
551 if (so->rx.idx >= so->rx.len)
555 if (so->rx.idx >= so->rx.len) {
557 so->rx.state = ISOTP_IDLE;
559 if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
560 check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
561 /* malformed PDU - report 'not a data message' */
562 sk->sk_err = EBADMSG;
563 if (!sock_flag(sk, SOCK_DEAD))
568 nskb = alloc_skb(so->rx.len, gfp_any());
572 memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
575 nskb->tstamp = skb->tstamp;
576 nskb->dev = skb->dev;
577 isotp_rcv_skb(nskb, sk);
581 /* perform blocksize handling, if enabled */
582 if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
583 /* start rx timeout watchdog */
584 hrtimer_start(&so->rxtimer, ktime_set(1, 0),
585 HRTIMER_MODE_REL_SOFT);
589 /* no creation of flow control frames */
590 if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
593 /* we reached the specified blocksize so->rxfc.bs */
594 isotp_send_fc(sk, ae, ISOTP_FC_CTS);
598 static void isotp_rcv(struct sk_buff *skb, void *data)
600 struct sock *sk = (struct sock *)data;
601 struct isotp_sock *so = isotp_sk(sk);
602 struct canfd_frame *cf;
603 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
604 u8 n_pci_type, sf_dl;
606 /* Strictly receive only frames with the configured MTU size
607 * => clear separation of CAN2.0 / CAN FD transport channels
609 if (skb->len != so->ll.mtu)
612 cf = (struct canfd_frame *)skb->data;
614 /* if enabled: check reception of my configured extended address */
615 if (ae && cf->data[0] != so->opt.rx_ext_address)
618 n_pci_type = cf->data[ae] & 0xF0;
620 /* Make sure the state changes and data structures stay consistent at
621 * CAN frame reception time. This locking is not needed in real world
622 * use cases but the inconsistency can be triggered with syzkaller.
624 spin_lock(&so->rx_lock);
626 if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
627 /* check rx/tx path half duplex expectations */
628 if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
629 (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
633 switch (n_pci_type) {
635 /* tx path: flow control frame containing the FC parameters */
636 isotp_rcv_fc(so, cf, ae);
640 /* rx path: single frame
642 * As we do not have a rx.ll_dl configuration, we can only test
643 * if the CAN frames payload length matches the LL_DL == 8
644 * requirements - no matter if it's CAN 2.0 or CAN FD
647 /* get the SF_DL from the N_PCI byte */
648 sf_dl = cf->data[ae] & 0x0F;
650 if (cf->len <= CAN_MAX_DLEN) {
651 isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
653 if (skb->len == CANFD_MTU) {
654 /* We have a CAN FD frame and CAN_DL is greater than 8:
655 * Only frames with the SF_DL == 0 ESC value are valid.
657 * If so take care of the increased SF PCI size
658 * (SF_PCI_SZ8) to point to the message content behind
659 * the extended SF PCI info and get the real SF_DL
660 * length value from the formerly first data byte.
663 isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
664 cf->data[SF_PCI_SZ4 + ae]);
670 /* rx path: first frame */
671 isotp_rcv_ff(sk, cf, ae);
675 /* rx path: consecutive frame */
676 isotp_rcv_cf(sk, cf, ae, skb);
681 spin_unlock(&so->rx_lock);
684 static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
687 int pcilen = N_PCI_SZ + ae + off;
688 int space = so->tx.ll_dl - pcilen;
689 int num = min_t(int, so->tx.len - so->tx.idx, space);
692 cf->can_id = so->txid;
693 cf->len = num + pcilen;
696 if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
697 /* user requested padding */
698 cf->len = padlen(cf->len);
699 memset(cf->data, so->opt.txpad_content, cf->len);
700 } else if (cf->len > CAN_MAX_DLEN) {
701 /* mandatory padding for CAN FD frames */
702 cf->len = padlen(cf->len);
703 memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
708 for (i = 0; i < num; i++)
709 cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
712 cf->data[0] = so->opt.ext_address;
715 static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
721 cf->can_id = so->txid;
722 cf->len = so->tx.ll_dl;
724 cf->data[0] = so->opt.ext_address;
726 /* create N_PCI bytes with 12/32 bit FF_DL data length */
727 if (so->tx.len > 4095) {
728 /* use 32 bit FF_DL notation */
729 cf->data[ae] = N_PCI_FF;
730 cf->data[ae + 1] = 0;
731 cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
732 cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
733 cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
734 cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
735 ff_pci_sz = FF_PCI_SZ32;
737 /* use 12 bit FF_DL notation */
738 cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
739 cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
740 ff_pci_sz = FF_PCI_SZ12;
743 /* add first data bytes depending on ae */
744 for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
745 cf->data[i] = so->tx.buf[so->tx.idx++];
748 so->tx.state = ISOTP_WAIT_FIRST_FC;
751 static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
753 struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
755 struct sock *sk = &so->sk;
757 struct net_device *dev;
758 struct canfd_frame *cf;
759 enum hrtimer_restart restart = HRTIMER_NORESTART;
761 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
763 switch (so->tx.state) {
765 case ISOTP_WAIT_FIRST_FC:
767 /* we did not get any flow control frame in time */
769 /* report 'communication error on send' */
771 if (!sock_flag(sk, SOCK_DEAD))
775 so->tx.state = ISOTP_IDLE;
776 wake_up_interruptible(&so->wait);
781 /* push out the next segmented pdu */
782 dev = dev_get_by_index(sock_net(sk), so->ifindex);
787 skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
794 can_skb_reserve(skb);
795 can_skb_prv(skb)->ifindex = dev->ifindex;
796 can_skb_prv(skb)->skbcnt = 0;
798 cf = (struct canfd_frame *)skb->data;
799 skb_put_zero(skb, so->ll.mtu);
801 /* create consecutive frame */
802 isotp_fill_dataframe(cf, so, ae, 0);
804 /* place consecutive frame N_PCI in appropriate index */
805 cf->data[ae] = N_PCI_CF | so->tx.sn++;
809 cf->flags = so->ll.tx_flags;
812 can_skb_set_owner(skb, sk);
814 can_send_ret = can_send(skb, 1);
816 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
817 __func__, ERR_PTR(can_send_ret));
818 if (can_send_ret == -ENOBUFS)
819 pr_notice_once("can-isotp: tx queue is full, increasing txqueuelen may prevent this error\n");
821 if (so->tx.idx >= so->tx.len) {
823 so->tx.state = ISOTP_IDLE;
825 wake_up_interruptible(&so->wait);
829 if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
830 /* stop and wait for FC */
831 so->tx.state = ISOTP_WAIT_FC;
833 hrtimer_set_expires(&so->txtimer,
834 ktime_add(ktime_get(),
836 restart = HRTIMER_RESTART;
840 /* no gap between data frames needed => use burst mode */
844 /* start timer to send next data frame with correct delay */
846 hrtimer_set_expires(&so->txtimer,
847 ktime_add(ktime_get(), so->tx_gap));
848 restart = HRTIMER_RESTART;
858 static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
860 struct sock *sk = sock->sk;
861 struct isotp_sock *so = isotp_sk(sk);
862 u32 old_state = so->tx.state;
864 struct net_device *dev;
865 struct canfd_frame *cf;
866 int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
867 int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
872 return -EADDRNOTAVAIL;
874 /* we do not support multiple buffers - for now */
875 if (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE ||
876 wq_has_sleeper(&so->wait)) {
877 if (msg->msg_flags & MSG_DONTWAIT) {
882 /* wait for complete transmission of current pdu */
883 err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
888 if (!size || size > MAX_MSG_LENGTH) {
893 /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
894 off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
896 /* does the given data fit into a single frame for SF_BROADCAST? */
897 if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) &&
898 (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
903 err = memcpy_from_msg(so->tx.buf, msg, size);
907 dev = dev_get_by_index(sock_net(sk), so->ifindex);
913 skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
914 msg->msg_flags & MSG_DONTWAIT, &err);
920 can_skb_reserve(skb);
921 can_skb_prv(skb)->ifindex = dev->ifindex;
922 can_skb_prv(skb)->skbcnt = 0;
927 cf = (struct canfd_frame *)skb->data;
928 skb_put_zero(skb, so->ll.mtu);
930 /* check for single frame transmission depending on TX_DL */
931 if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
932 /* The message size generally fits into a SingleFrame - good.
934 * SF_DL ESC offset optimization:
936 * When TX_DL is greater 8 but the message would still fit
937 * into a 8 byte CAN frame, we can omit the offset.
938 * This prevents a protocol caused length extension from
939 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
941 if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
944 isotp_fill_dataframe(cf, so, ae, off);
946 /* place single frame N_PCI w/o length in appropriate index */
947 cf->data[ae] = N_PCI_SF;
949 /* place SF_DL size value depending on the SF_DL ESC offset */
951 cf->data[SF_PCI_SZ4 + ae] = size;
953 cf->data[ae] |= size;
955 so->tx.state = ISOTP_IDLE;
956 wake_up_interruptible(&so->wait);
958 /* don't enable wait queue for a single frame transmission */
961 /* send first frame and wait for FC */
963 isotp_create_fframe(cf, so, ae);
965 /* start timeout for FC */
966 hrtimer_start(&so->txtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
969 /* send the first or only CAN frame */
970 cf->flags = so->ll.tx_flags;
974 err = can_send(skb, 1);
977 pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
978 __func__, ERR_PTR(err));
983 /* wait for complete transmission of current pdu */
984 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
993 /* drop this PDU and unlock a potential wait queue */
994 old_state = ISOTP_IDLE;
996 so->tx.state = old_state;
997 if (so->tx.state == ISOTP_IDLE)
998 wake_up_interruptible(&so->wait);
1003 static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1006 struct sock *sk = sock->sk;
1007 struct sk_buff *skb;
1011 noblock = flags & MSG_DONTWAIT;
1012 flags &= ~MSG_DONTWAIT;
1014 skb = skb_recv_datagram(sk, flags, noblock, &err);
1018 if (size < skb->len)
1019 msg->msg_flags |= MSG_TRUNC;
1023 err = memcpy_to_msg(msg, skb->data, size);
1025 skb_free_datagram(sk, skb);
1029 sock_recv_timestamp(msg, sk, skb);
1031 if (msg->msg_name) {
1032 __sockaddr_check_size(ISOTP_MIN_NAMELEN);
1033 msg->msg_namelen = ISOTP_MIN_NAMELEN;
1034 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1037 skb_free_datagram(sk, skb);
1042 static int isotp_release(struct socket *sock)
1044 struct sock *sk = sock->sk;
1045 struct isotp_sock *so;
1054 /* wait for complete transmission of current pdu */
1055 wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
1057 spin_lock(&isotp_notifier_lock);
1058 while (isotp_busy_notifier == so) {
1059 spin_unlock(&isotp_notifier_lock);
1060 schedule_timeout_uninterruptible(1);
1061 spin_lock(&isotp_notifier_lock);
1063 list_del(&so->notifier);
1064 spin_unlock(&isotp_notifier_lock);
1068 /* remove current filters & unregister */
1069 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) {
1071 struct net_device *dev;
1073 dev = dev_get_by_index(net, so->ifindex);
1075 can_rx_unregister(net, dev, so->rxid,
1076 SINGLE_MASK(so->rxid),
1084 hrtimer_cancel(&so->txtimer);
1085 hrtimer_cancel(&so->rxtimer);
1099 static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
1101 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1102 struct sock *sk = sock->sk;
1103 struct isotp_sock *so = isotp_sk(sk);
1104 struct net *net = sock_net(sk);
1106 struct net_device *dev;
1108 int notify_enetdown = 0;
1111 if (len < ISOTP_MIN_NAMELEN)
1114 if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
1115 return -EADDRNOTAVAIL;
1117 if (!addr->can_ifindex)
1122 /* do not register frame reception for functional addressing */
1123 if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
1126 /* do not validate rx address for functional addressing */
1128 if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id) {
1129 err = -EADDRNOTAVAIL;
1133 if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
1134 err = -EADDRNOTAVAIL;
1139 if (so->bound && addr->can_ifindex == so->ifindex &&
1140 addr->can_addr.tp.rx_id == so->rxid &&
1141 addr->can_addr.tp.tx_id == so->txid)
1144 dev = dev_get_by_index(net, addr->can_ifindex);
1149 if (dev->type != ARPHRD_CAN) {
1154 if (dev->mtu < so->ll.mtu) {
1159 if (!(dev->flags & IFF_UP))
1160 notify_enetdown = 1;
1162 ifindex = dev->ifindex;
1165 can_rx_register(net, dev, addr->can_addr.tp.rx_id,
1166 SINGLE_MASK(addr->can_addr.tp.rx_id),
1167 isotp_rcv, sk, "isotp", sk);
1171 if (so->bound && do_rx_reg) {
1172 /* unregister old filter */
1174 dev = dev_get_by_index(net, so->ifindex);
1176 can_rx_unregister(net, dev, so->rxid,
1177 SINGLE_MASK(so->rxid),
1184 /* switch to new settings */
1185 so->ifindex = ifindex;
1186 so->rxid = addr->can_addr.tp.rx_id;
1187 so->txid = addr->can_addr.tp.tx_id;
1193 if (notify_enetdown) {
1194 sk->sk_err = ENETDOWN;
1195 if (!sock_flag(sk, SOCK_DEAD))
1196 sk_error_report(sk);
1202 static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
1204 struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1205 struct sock *sk = sock->sk;
1206 struct isotp_sock *so = isotp_sk(sk);
1211 memset(addr, 0, ISOTP_MIN_NAMELEN);
1212 addr->can_family = AF_CAN;
1213 addr->can_ifindex = so->ifindex;
1214 addr->can_addr.tp.rx_id = so->rxid;
1215 addr->can_addr.tp.tx_id = so->txid;
1217 return ISOTP_MIN_NAMELEN;
1220 static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
1221 sockptr_t optval, unsigned int optlen)
1223 struct sock *sk = sock->sk;
1224 struct isotp_sock *so = isotp_sk(sk);
1231 case CAN_ISOTP_OPTS:
1232 if (optlen != sizeof(struct can_isotp_options))
1235 if (copy_from_sockptr(&so->opt, optval, optlen))
1238 /* no separate rx_ext_address is given => use ext_address */
1239 if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
1240 so->opt.rx_ext_address = so->opt.ext_address;
1243 case CAN_ISOTP_RECV_FC:
1244 if (optlen != sizeof(struct can_isotp_fc_options))
1247 if (copy_from_sockptr(&so->rxfc, optval, optlen))
1251 case CAN_ISOTP_TX_STMIN:
1252 if (optlen != sizeof(u32))
1255 if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
1259 case CAN_ISOTP_RX_STMIN:
1260 if (optlen != sizeof(u32))
1263 if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
1267 case CAN_ISOTP_LL_OPTS:
1268 if (optlen == sizeof(struct can_isotp_ll_options)) {
1269 struct can_isotp_ll_options ll;
1271 if (copy_from_sockptr(&ll, optval, optlen))
1274 /* check for correct ISO 11898-1 DLC data length */
1275 if (ll.tx_dl != padlen(ll.tx_dl))
1278 if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
1281 if (ll.mtu == CAN_MTU &&
1282 (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
1285 memcpy(&so->ll, &ll, sizeof(ll));
1287 /* set ll_dl for tx path to similar place as for rx */
1288 so->tx.ll_dl = ll.tx_dl;
1301 static int isotp_setsockopt(struct socket *sock, int level, int optname,
1302 sockptr_t optval, unsigned int optlen)
1305 struct sock *sk = sock->sk;
1308 if (level != SOL_CAN_ISOTP)
1312 ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
1317 static int isotp_getsockopt(struct socket *sock, int level, int optname,
1318 char __user *optval, int __user *optlen)
1320 struct sock *sk = sock->sk;
1321 struct isotp_sock *so = isotp_sk(sk);
1325 if (level != SOL_CAN_ISOTP)
1327 if (get_user(len, optlen))
1333 case CAN_ISOTP_OPTS:
1334 len = min_t(int, len, sizeof(struct can_isotp_options));
1338 case CAN_ISOTP_RECV_FC:
1339 len = min_t(int, len, sizeof(struct can_isotp_fc_options));
1343 case CAN_ISOTP_TX_STMIN:
1344 len = min_t(int, len, sizeof(u32));
1345 val = &so->force_tx_stmin;
1348 case CAN_ISOTP_RX_STMIN:
1349 len = min_t(int, len, sizeof(u32));
1350 val = &so->force_rx_stmin;
1353 case CAN_ISOTP_LL_OPTS:
1354 len = min_t(int, len, sizeof(struct can_isotp_ll_options));
1359 return -ENOPROTOOPT;
1362 if (put_user(len, optlen))
1364 if (copy_to_user(optval, val, len))
1369 static void isotp_notify(struct isotp_sock *so, unsigned long msg,
1370 struct net_device *dev)
1372 struct sock *sk = &so->sk;
1374 if (!net_eq(dev_net(dev), sock_net(sk)))
1377 if (so->ifindex != dev->ifindex)
1381 case NETDEV_UNREGISTER:
1383 /* remove current filters & unregister */
1384 if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))
1385 can_rx_unregister(dev_net(dev), dev, so->rxid,
1386 SINGLE_MASK(so->rxid),
1393 sk->sk_err = ENODEV;
1394 if (!sock_flag(sk, SOCK_DEAD))
1395 sk_error_report(sk);
1399 sk->sk_err = ENETDOWN;
1400 if (!sock_flag(sk, SOCK_DEAD))
1401 sk_error_report(sk);
1406 static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
1409 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1411 if (dev->type != ARPHRD_CAN)
1413 if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
1415 if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
1418 spin_lock(&isotp_notifier_lock);
1419 list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
1420 spin_unlock(&isotp_notifier_lock);
1421 isotp_notify(isotp_busy_notifier, msg, dev);
1422 spin_lock(&isotp_notifier_lock);
1424 isotp_busy_notifier = NULL;
1425 spin_unlock(&isotp_notifier_lock);
1429 static int isotp_init(struct sock *sk)
1431 struct isotp_sock *so = isotp_sk(sk);
1436 so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
1437 so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1438 so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
1439 so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1440 so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
1441 so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
1442 so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
1443 so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
1444 so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
1445 so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
1446 so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
1447 so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
1449 /* set ll_dl for tx path to similar place as for rx */
1450 so->tx.ll_dl = so->ll.tx_dl;
1452 so->rx.state = ISOTP_IDLE;
1453 so->tx.state = ISOTP_IDLE;
1455 hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1456 so->rxtimer.function = isotp_rx_timer_handler;
1457 hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1458 so->txtimer.function = isotp_tx_timer_handler;
1460 init_waitqueue_head(&so->wait);
1461 spin_lock_init(&so->rx_lock);
1463 spin_lock(&isotp_notifier_lock);
1464 list_add_tail(&so->notifier, &isotp_notifier_list);
1465 spin_unlock(&isotp_notifier_lock);
1470 static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
1473 /* no ioctls for socket layer -> hand it down to NIC layer */
1474 return -ENOIOCTLCMD;
1477 static const struct proto_ops isotp_ops = {
1479 .release = isotp_release,
1481 .connect = sock_no_connect,
1482 .socketpair = sock_no_socketpair,
1483 .accept = sock_no_accept,
1484 .getname = isotp_getname,
1485 .poll = datagram_poll,
1486 .ioctl = isotp_sock_no_ioctlcmd,
1487 .gettstamp = sock_gettstamp,
1488 .listen = sock_no_listen,
1489 .shutdown = sock_no_shutdown,
1490 .setsockopt = isotp_setsockopt,
1491 .getsockopt = isotp_getsockopt,
1492 .sendmsg = isotp_sendmsg,
1493 .recvmsg = isotp_recvmsg,
1494 .mmap = sock_no_mmap,
1495 .sendpage = sock_no_sendpage,
1498 static struct proto isotp_proto __read_mostly = {
1499 .name = "CAN_ISOTP",
1500 .owner = THIS_MODULE,
1501 .obj_size = sizeof(struct isotp_sock),
1505 static const struct can_proto isotp_can_proto = {
1507 .protocol = CAN_ISOTP,
1509 .prot = &isotp_proto,
1512 static struct notifier_block canisotp_notifier = {
1513 .notifier_call = isotp_notifier
1516 static __init int isotp_module_init(void)
1520 pr_info("can: isotp protocol\n");
1522 err = can_proto_register(&isotp_can_proto);
1524 pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
1526 register_netdevice_notifier(&canisotp_notifier);
1531 static __exit void isotp_module_exit(void)
1533 can_proto_unregister(&isotp_can_proto);
1534 unregister_netdevice_notifier(&canisotp_notifier);
1537 module_init(isotp_module_init);
1538 module_exit(isotp_module_exit);