forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathgw.c
1336 lines (1071 loc) · 33.8 KB
/
gw.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)
/* gw.c - CAN frame Gateway/Router/Bridge with netlink interface
*
* Copyright (c) 2019 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/types.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/rculist.h>
#include <linux/net.h>
#include <linux/netdevice.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/gw.h>
#include <net/rtnetlink.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#define CAN_GW_NAME "can-gw"
MODULE_DESCRIPTION("PF_CAN netlink gateway");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Oliver Hartkopp <[email protected]>");
MODULE_ALIAS(CAN_GW_NAME);
#define CGW_MIN_HOPS 1
#define CGW_MAX_HOPS 6
#define CGW_DEFAULT_HOPS 1
static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
module_param(max_hops, uint, 0444);
MODULE_PARM_DESC(max_hops,
"maximum " CAN_GW_NAME " routing hops for CAN frames "
"(valid values: " __stringify(CGW_MIN_HOPS) "-"
__stringify(CGW_MAX_HOPS) " hops, "
"default: " __stringify(CGW_DEFAULT_HOPS) ")");
static struct notifier_block notifier;
static struct kmem_cache *cgw_cache __read_mostly;
/* structure that contains the (on-the-fly) CAN frame modifications */
struct cf_mod {
struct {
struct canfd_frame and;
struct canfd_frame or;
struct canfd_frame xor;
struct canfd_frame set;
} modframe;
struct {
u8 and;
u8 or;
u8 xor;
u8 set;
} modtype;
void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf,
struct cf_mod *mod);
/* CAN frame checksum calculation after CAN frame modifications */
struct {
struct cgw_csum_xor xor;
struct cgw_csum_crc8 crc8;
} csum;
struct {
void (*xor)(struct canfd_frame *cf,
struct cgw_csum_xor *xor);
void (*crc8)(struct canfd_frame *cf,
struct cgw_csum_crc8 *crc8);
} csumfunc;
u32 uid;
};
/* So far we just support CAN -> CAN routing and frame modifications.
*
* The internal can_can_gw structure contains data and attributes for
* a CAN -> CAN gateway job.
*/
struct can_can_gw {
struct can_filter filter;
int src_idx;
int dst_idx;
};
/* list entry for CAN gateways jobs */
struct cgw_job {
struct hlist_node list;
struct rcu_head rcu;
u32 handled_frames;
u32 dropped_frames;
u32 deleted_frames;
struct cf_mod mod;
union {
/* CAN frame data source */
struct net_device *dev;
} src;
union {
/* CAN frame data destination */
struct net_device *dev;
} dst;
union {
struct can_can_gw ccgw;
/* tbc */
};
u8 gwtype;
u8 limit_hops;
u16 flags;
};
/* modification functions that are invoked in the hot path in can_can_gw_rcv */
#define MODFUNC(func, op) static void func(struct canfd_frame *cf, \
struct cf_mod *mod) { op ; }
MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len)
MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags)
MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len)
MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags)
MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len)
MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags)
MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
MODFUNC(mod_set_len, cf->len = mod->modframe.set.len)
MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags)
MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod)
{
int i;
for (i = 0; i < CANFD_MAX_DLEN; i += 8)
*(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i);
}
static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod)
{
int i;
for (i = 0; i < CANFD_MAX_DLEN; i += 8)
*(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i);
}
static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod)
{
int i;
for (i = 0; i < CANFD_MAX_DLEN; i += 8)
*(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i);
}
static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod)
{
memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN);
}
/* retrieve valid CC DLC value and store it into 'len' */
static void mod_retrieve_ccdlc(struct canfd_frame *cf)
{
struct can_frame *ccf = (struct can_frame *)cf;
/* len8_dlc is only valid if len == CAN_MAX_DLEN */
if (ccf->len != CAN_MAX_DLEN)
return;
/* do we have a valid len8_dlc value from 9 .. 15 ? */
if (ccf->len8_dlc > CAN_MAX_DLEN && ccf->len8_dlc <= CAN_MAX_RAW_DLC)
ccf->len = ccf->len8_dlc;
}
/* convert valid CC DLC value in 'len' into struct can_frame elements */
static void mod_store_ccdlc(struct canfd_frame *cf)
{
struct can_frame *ccf = (struct can_frame *)cf;
/* clear potential leftovers */
ccf->len8_dlc = 0;
/* plain data length 0 .. 8 - that was easy */
if (ccf->len <= CAN_MAX_DLEN)
return;
/* potentially broken values are caught in can_can_gw_rcv() */
if (ccf->len > CAN_MAX_RAW_DLC)
return;
/* we have a valid dlc value from 9 .. 15 in ccf->len */
ccf->len8_dlc = ccf->len;
ccf->len = CAN_MAX_DLEN;
}
static void mod_and_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
{
mod_retrieve_ccdlc(cf);
mod_and_len(cf, mod);
mod_store_ccdlc(cf);
}
static void mod_or_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
{
mod_retrieve_ccdlc(cf);
mod_or_len(cf, mod);
mod_store_ccdlc(cf);
}
static void mod_xor_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
{
mod_retrieve_ccdlc(cf);
mod_xor_len(cf, mod);
mod_store_ccdlc(cf);
}
static void mod_set_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
{
mod_set_len(cf, mod);
mod_store_ccdlc(cf);
}
static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
{
/* Copy the struct members separately to ensure that no uninitialized
* data are copied in the 3 bytes hole of the struct. This is needed
* to make easy compares of the data in the struct cf_mod.
*/
dst->can_id = src->can_id;
dst->len = src->len;
*(u64 *)dst->data = *(u64 *)src->data;
}
static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src)
{
/* Copy the struct members separately to ensure that no uninitialized
* data are copied in the 2 bytes hole of the struct. This is needed
* to make easy compares of the data in the struct cf_mod.
*/
dst->can_id = src->can_id;
dst->flags = src->flags;
dst->len = src->len;
memcpy(dst->data, src->data, CANFD_MAX_DLEN);
}
static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r)
{
s8 dlen = CAN_MAX_DLEN;
if (r->flags & CGW_FLAGS_CAN_FD)
dlen = CANFD_MAX_DLEN;
/* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
* relative to received dlc -1 .. -8 :
* e.g. for received dlc = 8
* -1 => index = 7 (data[7])
* -3 => index = 5 (data[5])
* -8 => index = 0 (data[0])
*/
if (fr >= -dlen && fr < dlen &&
to >= -dlen && to < dlen &&
re >= -dlen && re < dlen)
return 0;
else
return -EINVAL;
}
static inline int calc_idx(int idx, int rx_len)
{
if (idx < 0)
return rx_len + idx;
else
return idx;
}
static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor)
{
int from = calc_idx(xor->from_idx, cf->len);
int to = calc_idx(xor->to_idx, cf->len);
int res = calc_idx(xor->result_idx, cf->len);
u8 val = xor->init_xor_val;
int i;
if (from < 0 || to < 0 || res < 0)
return;
if (from <= to) {
for (i = from; i <= to; i++)
val ^= cf->data[i];
} else {
for (i = from; i >= to; i--)
val ^= cf->data[i];
}
cf->data[res] = val;
}
static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor)
{
u8 val = xor->init_xor_val;
int i;
for (i = xor->from_idx; i <= xor->to_idx; i++)
val ^= cf->data[i];
cf->data[xor->result_idx] = val;
}
static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor)
{
u8 val = xor->init_xor_val;
int i;
for (i = xor->from_idx; i >= xor->to_idx; i--)
val ^= cf->data[i];
cf->data[xor->result_idx] = val;
}
static void cgw_csum_crc8_rel(struct canfd_frame *cf,
struct cgw_csum_crc8 *crc8)
{
int from = calc_idx(crc8->from_idx, cf->len);
int to = calc_idx(crc8->to_idx, cf->len);
int res = calc_idx(crc8->result_idx, cf->len);
u8 crc = crc8->init_crc_val;
int i;
if (from < 0 || to < 0 || res < 0)
return;
if (from <= to) {
for (i = crc8->from_idx; i <= crc8->to_idx; i++)
crc = crc8->crctab[crc ^ cf->data[i]];
} else {
for (i = crc8->from_idx; i >= crc8->to_idx; i--)
crc = crc8->crctab[crc ^ cf->data[i]];
}
switch (crc8->profile) {
case CGW_CRC8PRF_1U8:
crc = crc8->crctab[crc ^ crc8->profile_data[0]];
break;
case CGW_CRC8PRF_16U8:
crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
break;
case CGW_CRC8PRF_SFFID_XOR:
crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
(cf->can_id >> 8 & 0xFF)];
break;
}
cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
}
static void cgw_csum_crc8_pos(struct canfd_frame *cf,
struct cgw_csum_crc8 *crc8)
{
u8 crc = crc8->init_crc_val;
int i;
for (i = crc8->from_idx; i <= crc8->to_idx; i++)
crc = crc8->crctab[crc ^ cf->data[i]];
switch (crc8->profile) {
case CGW_CRC8PRF_1U8:
crc = crc8->crctab[crc ^ crc8->profile_data[0]];
break;
case CGW_CRC8PRF_16U8:
crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
break;
case CGW_CRC8PRF_SFFID_XOR:
crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
(cf->can_id >> 8 & 0xFF)];
break;
}
cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
}
static void cgw_csum_crc8_neg(struct canfd_frame *cf,
struct cgw_csum_crc8 *crc8)
{
u8 crc = crc8->init_crc_val;
int i;
for (i = crc8->from_idx; i >= crc8->to_idx; i--)
crc = crc8->crctab[crc ^ cf->data[i]];
switch (crc8->profile) {
case CGW_CRC8PRF_1U8:
crc = crc8->crctab[crc ^ crc8->profile_data[0]];
break;
case CGW_CRC8PRF_16U8:
crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
break;
case CGW_CRC8PRF_SFFID_XOR:
crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
(cf->can_id >> 8 & 0xFF)];
break;
}
cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
}
/* the receive & process & send function */
static void can_can_gw_rcv(struct sk_buff *skb, void *data)
{
struct cgw_job *gwj = (struct cgw_job *)data;
struct canfd_frame *cf;
struct sk_buff *nskb;
int modidx = 0;
/* process strictly Classic CAN or CAN FD frames */
if (gwj->flags & CGW_FLAGS_CAN_FD) {
if (!can_is_canfd_skb(skb))
return;
} else {
if (!can_is_can_skb(skb))
return;
}
/* Do not handle CAN frames routed more than 'max_hops' times.
* In general we should never catch this delimiter which is intended
* to cover a misconfiguration protection (e.g. circular CAN routes).
*
* The Controller Area Network controllers only accept CAN frames with
* correct CRCs - which are not visible in the controller registers.
* According to skbuff.h documentation the csum_start element for IP
* checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY.
* Only CAN skbs can be processed here which already have this property.
*/
#define cgw_hops(skb) ((skb)->csum_start)
BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
if (cgw_hops(skb) >= max_hops) {
/* indicate deleted frames due to misconfiguration */
gwj->deleted_frames++;
return;
}
if (!(gwj->dst.dev->flags & IFF_UP)) {
gwj->dropped_frames++;
return;
}
/* is sending the skb back to the incoming interface not allowed? */
if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex)
return;
/* clone the given skb, which has not been done in can_rcv()
*
* When there is at least one modification function activated,
* we need to copy the skb as we want to modify skb->data.
*/
if (gwj->mod.modfunc[0])
nskb = skb_copy(skb, GFP_ATOMIC);
else
nskb = skb_clone(skb, GFP_ATOMIC);
if (!nskb) {
gwj->dropped_frames++;
return;
}
/* put the incremented hop counter in the cloned skb */
cgw_hops(nskb) = cgw_hops(skb) + 1;
/* first processing of this CAN frame -> adjust to private hop limit */
if (gwj->limit_hops && cgw_hops(nskb) == 1)
cgw_hops(nskb) = max_hops - gwj->limit_hops + 1;
nskb->dev = gwj->dst.dev;
/* pointer to modifiable CAN frame */
cf = (struct canfd_frame *)nskb->data;
/* perform preprocessed modification functions if there are any */
while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
(*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
/* Has the CAN frame been modified? */
if (modidx) {
/* get available space for the processed CAN frame type */
int max_len = nskb->len - offsetof(struct canfd_frame, data);
/* dlc may have changed, make sure it fits to the CAN frame */
if (cf->len > max_len) {
/* delete frame due to misconfiguration */
gwj->deleted_frames++;
kfree_skb(nskb);
return;
}
/* check for checksum updates */
if (gwj->mod.csumfunc.crc8)
(*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
if (gwj->mod.csumfunc.xor)
(*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
}
/* clear the skb timestamp if not configured the other way */
if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
nskb->tstamp = 0;
/* send to netdevice */
if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
gwj->dropped_frames++;
else
gwj->handled_frames++;
}
static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
{
return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
gwj->ccgw.filter.can_mask, can_can_gw_rcv,
gwj, "gw", NULL);
}
static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
{
can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
}
static void cgw_job_free_rcu(struct rcu_head *rcu_head)
{
struct cgw_job *gwj = container_of(rcu_head, struct cgw_job, rcu);
kmem_cache_free(cgw_cache, gwj);
}
static int cgw_notifier(struct notifier_block *nb,
unsigned long msg, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net *net = dev_net(dev);
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
if (msg == NETDEV_UNREGISTER) {
struct cgw_job *gwj = NULL;
struct hlist_node *nx;
ASSERT_RTNL();
hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
if (gwj->src.dev == dev || gwj->dst.dev == dev) {
hlist_del(&gwj->list);
cgw_unregister_filter(net, gwj);
call_rcu(&gwj->rcu, cgw_job_free_rcu);
}
}
}
return NOTIFY_DONE;
}
static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
u32 pid, u32 seq, int flags)
{
struct rtcanmsg *rtcan;
struct nlmsghdr *nlh;
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags);
if (!nlh)
return -EMSGSIZE;
rtcan = nlmsg_data(nlh);
rtcan->can_family = AF_CAN;
rtcan->gwtype = gwj->gwtype;
rtcan->flags = gwj->flags;
/* add statistics if available */
if (gwj->handled_frames) {
if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
goto cancel;
}
if (gwj->dropped_frames) {
if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
goto cancel;
}
if (gwj->deleted_frames) {
if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
goto cancel;
}
/* check non default settings of attributes */
if (gwj->limit_hops) {
if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0)
goto cancel;
}
if (gwj->flags & CGW_FLAGS_CAN_FD) {
struct cgw_fdframe_mod mb;
if (gwj->mod.modtype.and) {
memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.and;
if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0)
goto cancel;
}
if (gwj->mod.modtype.or) {
memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.or;
if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0)
goto cancel;
}
if (gwj->mod.modtype.xor) {
memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.xor;
if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0)
goto cancel;
}
if (gwj->mod.modtype.set) {
memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.set;
if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0)
goto cancel;
}
} else {
struct cgw_frame_mod mb;
if (gwj->mod.modtype.and) {
memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.and;
if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
goto cancel;
}
if (gwj->mod.modtype.or) {
memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.or;
if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
goto cancel;
}
if (gwj->mod.modtype.xor) {
memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.xor;
if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
goto cancel;
}
if (gwj->mod.modtype.set) {
memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
mb.modtype = gwj->mod.modtype.set;
if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
goto cancel;
}
}
if (gwj->mod.uid) {
if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0)
goto cancel;
}
if (gwj->mod.csumfunc.crc8) {
if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
&gwj->mod.csum.crc8) < 0)
goto cancel;
}
if (gwj->mod.csumfunc.xor) {
if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
&gwj->mod.csum.xor) < 0)
goto cancel;
}
if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
&gwj->ccgw.filter) < 0)
goto cancel;
}
if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
goto cancel;
if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
goto cancel;
}
nlmsg_end(skb, nlh);
return 0;
cancel:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
/* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct cgw_job *gwj = NULL;
int idx = 0;
int s_idx = cb->args[0];
rcu_read_lock();
hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
if (idx < s_idx)
goto cont;
if (cgw_put_job(skb, gwj, RTM_NEWROUTE,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0)
break;
cont:
idx++;
}
rcu_read_unlock();
cb->args[0] = idx;
return skb->len;
}
static const struct nla_policy cgw_policy[CGW_MAX + 1] = {
[CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) },
[CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) },
[CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) },
[CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) },
[CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) },
[CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) },
[CGW_SRC_IF] = { .type = NLA_U32 },
[CGW_DST_IF] = { .type = NLA_U32 },
[CGW_FILTER] = { .len = sizeof(struct can_filter) },
[CGW_LIM_HOPS] = { .type = NLA_U8 },
[CGW_MOD_UID] = { .type = NLA_U32 },
[CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) },
[CGW_FDMOD_OR] = { .len = sizeof(struct cgw_fdframe_mod) },
[CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) },
[CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) },
};
/* check for common and gwtype specific attributes */
static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
u8 gwtype, void *gwtypeattr, u8 *limhops)
{
struct nlattr *tb[CGW_MAX + 1];
struct rtcanmsg *r = nlmsg_data(nlh);
int modidx = 0;
int err = 0;
/* initialize modification & checksum data space */
memset(mod, 0, sizeof(*mod));
err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb,
CGW_MAX, cgw_policy, NULL);
if (err < 0)
return err;
if (tb[CGW_LIM_HOPS]) {
*limhops = nla_get_u8(tb[CGW_LIM_HOPS]);
if (*limhops < 1 || *limhops > max_hops)
return -EINVAL;
}
/* check for AND/OR/XOR/SET modifications */
if (r->flags & CGW_FLAGS_CAN_FD) {
struct cgw_fdframe_mod mb;
if (tb[CGW_FDMOD_AND]) {
nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN);
canfdframecpy(&mod->modframe.and, &mb.cf);
mod->modtype.and = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_and_id;
if (mb.modtype & CGW_MOD_LEN)
mod->modfunc[modidx++] = mod_and_len;
if (mb.modtype & CGW_MOD_FLAGS)
mod->modfunc[modidx++] = mod_and_flags;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_and_fddata;
}
if (tb[CGW_FDMOD_OR]) {
nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN);
canfdframecpy(&mod->modframe.or, &mb.cf);
mod->modtype.or = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_or_id;
if (mb.modtype & CGW_MOD_LEN)
mod->modfunc[modidx++] = mod_or_len;
if (mb.modtype & CGW_MOD_FLAGS)
mod->modfunc[modidx++] = mod_or_flags;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_or_fddata;
}
if (tb[CGW_FDMOD_XOR]) {
nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN);
canfdframecpy(&mod->modframe.xor, &mb.cf);
mod->modtype.xor = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_xor_id;
if (mb.modtype & CGW_MOD_LEN)
mod->modfunc[modidx++] = mod_xor_len;
if (mb.modtype & CGW_MOD_FLAGS)
mod->modfunc[modidx++] = mod_xor_flags;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_xor_fddata;
}
if (tb[CGW_FDMOD_SET]) {
nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN);
canfdframecpy(&mod->modframe.set, &mb.cf);
mod->modtype.set = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_set_id;
if (mb.modtype & CGW_MOD_LEN)
mod->modfunc[modidx++] = mod_set_len;
if (mb.modtype & CGW_MOD_FLAGS)
mod->modfunc[modidx++] = mod_set_flags;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_set_fddata;
}
} else {
struct cgw_frame_mod mb;
if (tb[CGW_MOD_AND]) {
nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.and, &mb.cf);
mod->modtype.and = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_and_id;
if (mb.modtype & CGW_MOD_DLC)
mod->modfunc[modidx++] = mod_and_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_and_data;
}
if (tb[CGW_MOD_OR]) {
nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.or, &mb.cf);
mod->modtype.or = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_or_id;
if (mb.modtype & CGW_MOD_DLC)
mod->modfunc[modidx++] = mod_or_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_or_data;
}
if (tb[CGW_MOD_XOR]) {
nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.xor, &mb.cf);
mod->modtype.xor = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_xor_id;
if (mb.modtype & CGW_MOD_DLC)
mod->modfunc[modidx++] = mod_xor_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_xor_data;
}
if (tb[CGW_MOD_SET]) {
nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.set, &mb.cf);
mod->modtype.set = mb.modtype;
if (mb.modtype & CGW_MOD_ID)
mod->modfunc[modidx++] = mod_set_id;
if (mb.modtype & CGW_MOD_DLC)
mod->modfunc[modidx++] = mod_set_ccdlc;
if (mb.modtype & CGW_MOD_DATA)
mod->modfunc[modidx++] = mod_set_data;
}
}
/* check for checksum operations after CAN frame modifications */
if (modidx) {
if (tb[CGW_CS_CRC8]) {
struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]);
err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
c->result_idx, r);
if (err)
return err;
nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
CGW_CS_CRC8_LEN);
/* select dedicated processing function to reduce
* runtime operations in receive hot path.
*/
if (c->from_idx < 0 || c->to_idx < 0 ||
c->result_idx < 0)
mod->csumfunc.crc8 = cgw_csum_crc8_rel;
else if (c->from_idx <= c->to_idx)
mod->csumfunc.crc8 = cgw_csum_crc8_pos;
else
mod->csumfunc.crc8 = cgw_csum_crc8_neg;
}
if (tb[CGW_CS_XOR]) {
struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]);
err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
c->result_idx, r);
if (err)