forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 17
/
isotp.c
1500 lines (1227 loc) · 37.7 KB
/
isotp.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
/* isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
*
* This implementation does not provide ISO-TP specific return values to the
* userspace.
*
* - RX path timeout of data reception leads to -ETIMEDOUT
* - RX path SN mismatch leads to -EILSEQ
* - RX path data reception with wrong padding leads to -EBADMSG
* - TX path flowcontrol reception timeout leads to -ECOMM
* - TX path flowcontrol reception overflow leads to -EMSGSIZE
* - TX path flowcontrol reception with wrong layout/padding leads to -EBADMSG
* - when a transfer (tx) is on the run the next write() blocks until it's done
* - use CAN_ISOTP_WAIT_TX_DONE flag to block the caller until the PDU is sent
* - as we have static buffers the check whether the PDU fits into the buffer
* is done at FF reception time (no support for sending 'wait frames')
* - take care of the tx-queue-len as traffic shaping is still on the TODO list
*
* Copyright (c) 2020 Volkswagen Group Electronic Research
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Volkswagen nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* Alternatively, provided that this notice is retained in full, this
* software may be distributed under the terms of the GNU General
* Public License ("GPL") version 2, in which case the provisions of the
* GPL apply INSTEAD OF those given above.
*
* The provided data structures and external interfaces from this code
* are not restricted to be used by modules with a GPL compatible license.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/hrtimer.h>
#include <linux/wait.h>
#include <linux/uio.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/socket.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/can.h>
#include <linux/can/core.h>
#include <linux/can/skb.h>
#include <linux/can/isotp.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/net_namespace.h>
MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Oliver Hartkopp <[email protected]>");
MODULE_ALIAS("can-proto-6");
#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
#define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
(CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
(CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
/* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
* take full 32 bit values (4 Gbyte). We would need some good concept to handle
* this between user space and kernel space. For now increase the static buffer
* to something about 8 kbyte to be able to test this new functionality.
*/
#define MAX_MSG_LENGTH 8200
/* N_PCI type values in bits 7-4 of N_PCI bytes */
#define N_PCI_SF 0x00 /* single frame */
#define N_PCI_FF 0x10 /* first frame */
#define N_PCI_CF 0x20 /* consecutive frame */
#define N_PCI_FC 0x30 /* flow control */
#define N_PCI_SZ 1 /* size of the PCI byte #1 */
#define SF_PCI_SZ4 1 /* size of SingleFrame PCI including 4 bit SF_DL */
#define SF_PCI_SZ8 2 /* size of SingleFrame PCI including 8 bit SF_DL */
#define FF_PCI_SZ12 2 /* size of FirstFrame PCI including 12 bit FF_DL */
#define FF_PCI_SZ32 6 /* size of FirstFrame PCI including 32 bit FF_DL */
#define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
#define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
/* Flow Status given in FC frame */
#define ISOTP_FC_CTS 0 /* clear to send */
#define ISOTP_FC_WT 1 /* wait */
#define ISOTP_FC_OVFLW 2 /* overflow */
enum {
ISOTP_IDLE = 0,
ISOTP_WAIT_FIRST_FC,
ISOTP_WAIT_FC,
ISOTP_WAIT_DATA,
ISOTP_SENDING
};
struct tpcon {
int idx;
int len;
u8 state;
u8 bs;
u8 sn;
u8 ll_dl;
u8 buf[MAX_MSG_LENGTH + 1];
};
struct isotp_sock {
struct sock sk;
int bound;
int ifindex;
canid_t txid;
canid_t rxid;
ktime_t tx_gap;
ktime_t lastrxcf_tstamp;
struct hrtimer rxtimer, txtimer;
struct can_isotp_options opt;
struct can_isotp_fc_options rxfc, txfc;
struct can_isotp_ll_options ll;
u32 force_tx_stmin;
u32 force_rx_stmin;
struct tpcon rx, tx;
struct list_head notifier;
wait_queue_head_t wait;
};
static LIST_HEAD(isotp_notifier_list);
static DEFINE_SPINLOCK(isotp_notifier_lock);
static struct isotp_sock *isotp_busy_notifier;
static inline struct isotp_sock *isotp_sk(const struct sock *sk)
{
return (struct isotp_sock *)sk;
}
static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
{
struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
rxtimer);
struct sock *sk = &so->sk;
if (so->rx.state == ISOTP_WAIT_DATA) {
/* we did not get new data frames in time */
/* report 'connection timed out' */
sk->sk_err = ETIMEDOUT;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
/* reset rx state */
so->rx.state = ISOTP_IDLE;
}
return HRTIMER_NORESTART;
}
static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
{
struct net_device *dev;
struct sk_buff *nskb;
struct canfd_frame *ncf;
struct isotp_sock *so = isotp_sk(sk);
int can_send_ret;
nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
if (!nskb)
return 1;
dev = dev_get_by_index(sock_net(sk), so->ifindex);
if (!dev) {
kfree_skb(nskb);
return 1;
}
can_skb_reserve(nskb);
can_skb_prv(nskb)->ifindex = dev->ifindex;
can_skb_prv(nskb)->skbcnt = 0;
nskb->dev = dev;
can_skb_set_owner(nskb, sk);
ncf = (struct canfd_frame *)nskb->data;
skb_put_zero(nskb, so->ll.mtu);
/* create & send flow control reply */
ncf->can_id = so->txid;
if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
ncf->len = CAN_MAX_DLEN;
} else {
ncf->len = ae + FC_CONTENT_SZ;
}
ncf->data[ae] = N_PCI_FC | flowstatus;
ncf->data[ae + 1] = so->rxfc.bs;
ncf->data[ae + 2] = so->rxfc.stmin;
if (ae)
ncf->data[0] = so->opt.ext_address;
ncf->flags = so->ll.tx_flags;
can_send_ret = can_send(nskb, 1);
if (can_send_ret)
pr_notice_once("can-isotp: %s: can_send_ret %d\n",
__func__, can_send_ret);
dev_put(dev);
/* reset blocksize counter */
so->rx.bs = 0;
/* reset last CF frame rx timestamp for rx stmin enforcement */
so->lastrxcf_tstamp = ktime_set(0, 0);
/* start rx timeout watchdog */
hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
return 0;
}
static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
{
struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
memset(addr, 0, sizeof(*addr));
addr->can_family = AF_CAN;
addr->can_ifindex = skb->dev->ifindex;
if (sock_queue_rcv_skb(sk, skb) < 0)
kfree_skb(skb);
}
static u8 padlen(u8 datalen)
{
static const u8 plen[] = {
8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
12, 12, 12, 12, /* 9 - 12 */
16, 16, 16, 16, /* 13 - 16 */
20, 20, 20, 20, /* 17 - 20 */
24, 24, 24, 24, /* 21 - 24 */
32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
48, 48, 48, 48, 48, 48, 48, 48 /* 41 - 48 */
};
if (datalen > 48)
return 64;
return plen[datalen];
}
/* check for length optimization and return 1/true when the check fails */
static int check_optimized(struct canfd_frame *cf, int start_index)
{
/* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
* padding would start at this point. E.g. if the padding would
* start at cf.data[7] cf->len has to be 7 to be optimal.
* Note: The data[] index starts with zero.
*/
if (cf->len <= CAN_MAX_DLEN)
return (cf->len != start_index);
/* This relation is also valid in the non-linear DLC range, where
* we need to take care of the minimal next possible CAN_DL.
* The correct check would be (padlen(cf->len) != padlen(start_index)).
* But as cf->len can only take discrete values from 12, .., 64 at this
* point the padlen(cf->len) is always equal to cf->len.
*/
return (cf->len != padlen(start_index));
}
/* check padding and return 1/true when the check fails */
static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
int start_index, u8 content)
{
int i;
/* no RX_PADDING value => check length of optimized frame length */
if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
return check_optimized(cf, start_index);
/* no valid test against empty value => ignore frame */
return 1;
}
/* check datalength of correctly padded CAN frame */
if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
cf->len != padlen(cf->len))
return 1;
/* check padding content */
if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
for (i = start_index; i < cf->len; i++)
if (cf->data[i] != content)
return 1;
}
return 0;
}
static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
{
struct sock *sk = &so->sk;
if (so->tx.state != ISOTP_WAIT_FC &&
so->tx.state != ISOTP_WAIT_FIRST_FC)
return 0;
hrtimer_cancel(&so->txtimer);
if ((cf->len < ae + FC_CONTENT_SZ) ||
((so->opt.flags & ISOTP_CHECK_PADDING) &&
check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
/* malformed PDU - report 'not a data message' */
sk->sk_err = EBADMSG;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
so->tx.state = ISOTP_IDLE;
wake_up_interruptible(&so->wait);
return 1;
}
/* get communication parameters only from the first FC frame */
if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
so->txfc.bs = cf->data[ae + 1];
so->txfc.stmin = cf->data[ae + 2];
/* fix wrong STmin values according spec */
if (so->txfc.stmin > 0x7F &&
(so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
so->txfc.stmin = 0x7F;
so->tx_gap = ktime_set(0, 0);
/* add transmission time for CAN frame N_As */
so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
/* add waiting time for consecutive frames N_Cs */
if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
so->tx_gap = ktime_add_ns(so->tx_gap,
so->force_tx_stmin);
else if (so->txfc.stmin < 0x80)
so->tx_gap = ktime_add_ns(so->tx_gap,
so->txfc.stmin * 1000000);
else
so->tx_gap = ktime_add_ns(so->tx_gap,
(so->txfc.stmin - 0xF0)
* 100000);
so->tx.state = ISOTP_WAIT_FC;
}
switch (cf->data[ae] & 0x0F) {
case ISOTP_FC_CTS:
so->tx.bs = 0;
so->tx.state = ISOTP_SENDING;
/* start cyclic timer for sending CF frame */
hrtimer_start(&so->txtimer, so->tx_gap,
HRTIMER_MODE_REL_SOFT);
break;
case ISOTP_FC_WT:
/* start timer to wait for next FC frame */
hrtimer_start(&so->txtimer, ktime_set(1, 0),
HRTIMER_MODE_REL_SOFT);
break;
case ISOTP_FC_OVFLW:
/* overflow on receiver side - report 'message too long' */
sk->sk_err = EMSGSIZE;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
fallthrough;
default:
/* stop this tx job */
so->tx.state = ISOTP_IDLE;
wake_up_interruptible(&so->wait);
}
return 0;
}
static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
struct sk_buff *skb, int len)
{
struct isotp_sock *so = isotp_sk(sk);
struct sk_buff *nskb;
hrtimer_cancel(&so->rxtimer);
so->rx.state = ISOTP_IDLE;
if (!len || len > cf->len - pcilen)
return 1;
if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
/* malformed PDU - report 'not a data message' */
sk->sk_err = EBADMSG;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
return 1;
}
nskb = alloc_skb(len, gfp_any());
if (!nskb)
return 1;
memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
nskb->tstamp = skb->tstamp;
nskb->dev = skb->dev;
isotp_rcv_skb(nskb, sk);
return 0;
}
static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
{
struct isotp_sock *so = isotp_sk(sk);
int i;
int off;
int ff_pci_sz;
hrtimer_cancel(&so->rxtimer);
so->rx.state = ISOTP_IDLE;
/* get the used sender LL_DL from the (first) CAN frame data length */
so->rx.ll_dl = padlen(cf->len);
/* the first frame has to use the entire frame up to LL_DL length */
if (cf->len != so->rx.ll_dl)
return 1;
/* get the FF_DL */
so->rx.len = (cf->data[ae] & 0x0F) << 8;
so->rx.len += cf->data[ae + 1];
/* Check for FF_DL escape sequence supporting 32 bit PDU length */
if (so->rx.len) {
ff_pci_sz = FF_PCI_SZ12;
} else {
/* FF_DL = 0 => get real length from next 4 bytes */
so->rx.len = cf->data[ae + 2] << 24;
so->rx.len += cf->data[ae + 3] << 16;
so->rx.len += cf->data[ae + 4] << 8;
so->rx.len += cf->data[ae + 5];
ff_pci_sz = FF_PCI_SZ32;
}
/* take care of a potential SF_DL ESC offset for TX_DL > 8 */
off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
return 1;
if (so->rx.len > MAX_MSG_LENGTH) {
/* send FC frame with overflow status */
isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
return 1;
}
/* copy the first received data bytes */
so->rx.idx = 0;
for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
so->rx.buf[so->rx.idx++] = cf->data[i];
/* initial setup for this pdu reception */
so->rx.sn = 1;
so->rx.state = ISOTP_WAIT_DATA;
/* no creation of flow control frames */
if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
return 0;
/* send our first FC frame */
isotp_send_fc(sk, ae, ISOTP_FC_CTS);
return 0;
}
static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
struct sk_buff *skb)
{
struct isotp_sock *so = isotp_sk(sk);
struct sk_buff *nskb;
int i;
if (so->rx.state != ISOTP_WAIT_DATA)
return 0;
/* drop if timestamp gap is less than force_rx_stmin nano secs */
if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
so->force_rx_stmin)
return 0;
so->lastrxcf_tstamp = skb->tstamp;
}
hrtimer_cancel(&so->rxtimer);
/* CFs are never longer than the FF */
if (cf->len > so->rx.ll_dl)
return 1;
/* CFs have usually the LL_DL length */
if (cf->len < so->rx.ll_dl) {
/* this is only allowed for the last CF */
if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
return 1;
}
if ((cf->data[ae] & 0x0F) != so->rx.sn) {
/* wrong sn detected - report 'illegal byte sequence' */
sk->sk_err = EILSEQ;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
/* reset rx state */
so->rx.state = ISOTP_IDLE;
return 1;
}
so->rx.sn++;
so->rx.sn %= 16;
for (i = ae + N_PCI_SZ; i < cf->len; i++) {
so->rx.buf[so->rx.idx++] = cf->data[i];
if (so->rx.idx >= so->rx.len)
break;
}
if (so->rx.idx >= so->rx.len) {
/* we are done */
so->rx.state = ISOTP_IDLE;
if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
/* malformed PDU - report 'not a data message' */
sk->sk_err = EBADMSG;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
return 1;
}
nskb = alloc_skb(so->rx.len, gfp_any());
if (!nskb)
return 1;
memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
so->rx.len);
nskb->tstamp = skb->tstamp;
nskb->dev = skb->dev;
isotp_rcv_skb(nskb, sk);
return 0;
}
/* perform blocksize handling, if enabled */
if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
/* start rx timeout watchdog */
hrtimer_start(&so->rxtimer, ktime_set(1, 0),
HRTIMER_MODE_REL_SOFT);
return 0;
}
/* no creation of flow control frames */
if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
return 0;
/* we reached the specified blocksize so->rxfc.bs */
isotp_send_fc(sk, ae, ISOTP_FC_CTS);
return 0;
}
static void isotp_rcv(struct sk_buff *skb, void *data)
{
struct sock *sk = (struct sock *)data;
struct isotp_sock *so = isotp_sk(sk);
struct canfd_frame *cf;
int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
u8 n_pci_type, sf_dl;
/* Strictly receive only frames with the configured MTU size
* => clear separation of CAN2.0 / CAN FD transport channels
*/
if (skb->len != so->ll.mtu)
return;
cf = (struct canfd_frame *)skb->data;
/* if enabled: check reception of my configured extended address */
if (ae && cf->data[0] != so->opt.rx_ext_address)
return;
n_pci_type = cf->data[ae] & 0xF0;
if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
/* check rx/tx path half duplex expectations */
if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
(so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
return;
}
switch (n_pci_type) {
case N_PCI_FC:
/* tx path: flow control frame containing the FC parameters */
isotp_rcv_fc(so, cf, ae);
break;
case N_PCI_SF:
/* rx path: single frame
*
* As we do not have a rx.ll_dl configuration, we can only test
* if the CAN frames payload length matches the LL_DL == 8
* requirements - no matter if it's CAN 2.0 or CAN FD
*/
/* get the SF_DL from the N_PCI byte */
sf_dl = cf->data[ae] & 0x0F;
if (cf->len <= CAN_MAX_DLEN) {
isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
} else {
if (skb->len == CANFD_MTU) {
/* We have a CAN FD frame and CAN_DL is greater than 8:
* Only frames with the SF_DL == 0 ESC value are valid.
*
* If so take care of the increased SF PCI size
* (SF_PCI_SZ8) to point to the message content behind
* the extended SF PCI info and get the real SF_DL
* length value from the formerly first data byte.
*/
if (sf_dl == 0)
isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
cf->data[SF_PCI_SZ4 + ae]);
}
}
break;
case N_PCI_FF:
/* rx path: first frame */
isotp_rcv_ff(sk, cf, ae);
break;
case N_PCI_CF:
/* rx path: consecutive frame */
isotp_rcv_cf(sk, cf, ae, skb);
break;
}
}
static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
int ae, int off)
{
int pcilen = N_PCI_SZ + ae + off;
int space = so->tx.ll_dl - pcilen;
int num = min_t(int, so->tx.len - so->tx.idx, space);
int i;
cf->can_id = so->txid;
cf->len = num + pcilen;
if (num < space) {
if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
/* user requested padding */
cf->len = padlen(cf->len);
memset(cf->data, so->opt.txpad_content, cf->len);
} else if (cf->len > CAN_MAX_DLEN) {
/* mandatory padding for CAN FD frames */
cf->len = padlen(cf->len);
memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
cf->len);
}
}
for (i = 0; i < num; i++)
cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
if (ae)
cf->data[0] = so->opt.ext_address;
}
static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
int ae)
{
int i;
int ff_pci_sz;
cf->can_id = so->txid;
cf->len = so->tx.ll_dl;
if (ae)
cf->data[0] = so->opt.ext_address;
/* create N_PCI bytes with 12/32 bit FF_DL data length */
if (so->tx.len > 4095) {
/* use 32 bit FF_DL notation */
cf->data[ae] = N_PCI_FF;
cf->data[ae + 1] = 0;
cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
ff_pci_sz = FF_PCI_SZ32;
} else {
/* use 12 bit FF_DL notation */
cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
ff_pci_sz = FF_PCI_SZ12;
}
/* add first data bytes depending on ae */
for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
cf->data[i] = so->tx.buf[so->tx.idx++];
so->tx.sn = 1;
so->tx.state = ISOTP_WAIT_FIRST_FC;
}
static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
{
struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
txtimer);
struct sock *sk = &so->sk;
struct sk_buff *skb;
struct net_device *dev;
struct canfd_frame *cf;
enum hrtimer_restart restart = HRTIMER_NORESTART;
int can_send_ret;
int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
switch (so->tx.state) {
case ISOTP_WAIT_FC:
case ISOTP_WAIT_FIRST_FC:
/* we did not get any flow control frame in time */
/* report 'communication error on send' */
sk->sk_err = ECOMM;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
/* reset tx state */
so->tx.state = ISOTP_IDLE;
wake_up_interruptible(&so->wait);
break;
case ISOTP_SENDING:
/* push out the next segmented pdu */
dev = dev_get_by_index(sock_net(sk), so->ifindex);
if (!dev)
break;
isotp_tx_burst:
skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
GFP_ATOMIC);
if (!skb) {
dev_put(dev);
break;
}
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
cf = (struct canfd_frame *)skb->data;
skb_put_zero(skb, so->ll.mtu);
/* create consecutive frame */
isotp_fill_dataframe(cf, so, ae, 0);
/* place consecutive frame N_PCI in appropriate index */
cf->data[ae] = N_PCI_CF | so->tx.sn++;
so->tx.sn %= 16;
so->tx.bs++;
cf->flags = so->ll.tx_flags;
skb->dev = dev;
can_skb_set_owner(skb, sk);
can_send_ret = can_send(skb, 1);
if (can_send_ret)
pr_notice_once("can-isotp: %s: can_send_ret %d\n",
__func__, can_send_ret);
if (so->tx.idx >= so->tx.len) {
/* we are done */
so->tx.state = ISOTP_IDLE;
dev_put(dev);
wake_up_interruptible(&so->wait);
break;
}
if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
/* stop and wait for FC */
so->tx.state = ISOTP_WAIT_FC;
dev_put(dev);
hrtimer_set_expires(&so->txtimer,
ktime_add(ktime_get(),
ktime_set(1, 0)));
restart = HRTIMER_RESTART;
break;
}
/* no gap between data frames needed => use burst mode */
if (!so->tx_gap)
goto isotp_tx_burst;
/* start timer to send next data frame with correct delay */
dev_put(dev);
hrtimer_set_expires(&so->txtimer,
ktime_add(ktime_get(), so->tx_gap));
restart = HRTIMER_RESTART;
break;
default:
WARN_ON_ONCE(1);
}
return restart;
}
static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
{
struct sock *sk = sock->sk;
struct isotp_sock *so = isotp_sk(sk);
struct sk_buff *skb;
struct net_device *dev;
struct canfd_frame *cf;
int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
int off;
int err;
if (!so->bound)
return -EADDRNOTAVAIL;
/* we do not support multiple buffers - for now */
if (so->tx.state != ISOTP_IDLE || wq_has_sleeper(&so->wait)) {
if (msg->msg_flags & MSG_DONTWAIT)
return -EAGAIN;
/* wait for complete transmission of current pdu */
wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
}
if (!size || size > MAX_MSG_LENGTH)
return -EINVAL;
/* take care of a potential SF_DL ESC offset for TX_DL > 8 */
off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
/* does the given data fit into a single frame for SF_BROADCAST? */
if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) &&
(size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off))
return -EINVAL;
err = memcpy_from_msg(so->tx.buf, msg, size);
if (err < 0)
return err;
dev = dev_get_by_index(sock_net(sk), so->ifindex);
if (!dev)
return -ENXIO;
skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
msg->msg_flags & MSG_DONTWAIT, &err);
if (!skb) {
dev_put(dev);
return err;
}
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
so->tx.state = ISOTP_SENDING;
so->tx.len = size;
so->tx.idx = 0;
cf = (struct canfd_frame *)skb->data;
skb_put_zero(skb, so->ll.mtu);
/* check for single frame transmission depending on TX_DL */
if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
/* The message size generally fits into a SingleFrame - good.
*
* SF_DL ESC offset optimization:
*
* When TX_DL is greater 8 but the message would still fit
* into a 8 byte CAN frame, we can omit the offset.
* This prevents a protocol caused length extension from
* CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
*/
if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
off = 0;
isotp_fill_dataframe(cf, so, ae, off);
/* place single frame N_PCI w/o length in appropriate index */
cf->data[ae] = N_PCI_SF;
/* place SF_DL size value depending on the SF_DL ESC offset */
if (off)
cf->data[SF_PCI_SZ4 + ae] = size;
else
cf->data[ae] |= size;
so->tx.state = ISOTP_IDLE;
wake_up_interruptible(&so->wait);
/* don't enable wait queue for a single frame transmission */
wait_tx_done = 0;
} else {
/* send first frame and wait for FC */
isotp_create_fframe(cf, so, ae);
/* start timeout for FC */
hrtimer_start(&so->txtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
}
/* send the first or only CAN frame */
cf->flags = so->ll.tx_flags;
skb->dev = dev;
skb->sk = sk;
err = can_send(skb, 1);
dev_put(dev);
if (err) {
pr_notice_once("can-isotp: %s: can_send_ret %d\n",
__func__, err);
return err;
}
if (wait_tx_done) {
/* wait for complete transmission of current pdu */
wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
}
return size;
}
static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
int flags)
{
struct sock *sk = sock->sk;
struct sk_buff *skb;
int err = 0;
int noblock;
noblock = flags & MSG_DONTWAIT;
flags &= ~MSG_DONTWAIT;
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb)
return err;
if (size < skb->len)
msg->msg_flags |= MSG_TRUNC;
else
size = skb->len;
err = memcpy_to_msg(msg, skb->data, size);
if (err < 0) {
skb_free_datagram(sk, skb);
return err;
}
sock_recv_timestamp(msg, sk, skb);
if (msg->msg_name) {
__sockaddr_check_size(ISOTP_MIN_NAMELEN);
msg->msg_namelen = ISOTP_MIN_NAMELEN;
memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
}
skb_free_datagram(sk, skb);