forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathiphc.c
1174 lines (1032 loc) · 33.5 KB
/
iphc.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
/*
* Copyright 2011, Siemens AG
* written by Alexander Smirnov <[email protected]>
*/
/* Based on patches from Jon Smirl <[email protected]>
* Copyright (c) 2011 Jon Smirl <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
/* Jon's code is based on 6lowpan implementation for Contiki which is:
* Copyright (c) 2008, Swedish Institute of Computer Science.
* 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 the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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/bitops.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <net/6lowpan.h>
#include <net/ipv6.h>
/* special link-layer handling */
#include <net/mac802154.h>
#include "6lowpan_i.h"
#include "nhc.h"
/* Values of fields within the IPHC encoding first byte */
#define LOWPAN_IPHC_TF_MASK 0x18
#define LOWPAN_IPHC_TF_00 0x00
#define LOWPAN_IPHC_TF_01 0x08
#define LOWPAN_IPHC_TF_10 0x10
#define LOWPAN_IPHC_TF_11 0x18
#define LOWPAN_IPHC_NH 0x04
#define LOWPAN_IPHC_HLIM_MASK 0x03
#define LOWPAN_IPHC_HLIM_00 0x00
#define LOWPAN_IPHC_HLIM_01 0x01
#define LOWPAN_IPHC_HLIM_10 0x02
#define LOWPAN_IPHC_HLIM_11 0x03
/* Values of fields within the IPHC encoding second byte */
#define LOWPAN_IPHC_CID 0x80
#define LOWPAN_IPHC_SAC 0x40
#define LOWPAN_IPHC_SAM_MASK 0x30
#define LOWPAN_IPHC_SAM_00 0x00
#define LOWPAN_IPHC_SAM_01 0x10
#define LOWPAN_IPHC_SAM_10 0x20
#define LOWPAN_IPHC_SAM_11 0x30
#define LOWPAN_IPHC_M 0x08
#define LOWPAN_IPHC_DAC 0x04
#define LOWPAN_IPHC_DAM_MASK 0x03
#define LOWPAN_IPHC_DAM_00 0x00
#define LOWPAN_IPHC_DAM_01 0x01
#define LOWPAN_IPHC_DAM_10 0x02
#define LOWPAN_IPHC_DAM_11 0x03
/* ipv6 address based on mac
* second bit-flip (Universe/Local) is done according RFC2464
*/
#define is_addr_mac_addr_based(a, m) \
((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \
(((a)->s6_addr[9]) == (m)[1]) && \
(((a)->s6_addr[10]) == (m)[2]) && \
(((a)->s6_addr[11]) == (m)[3]) && \
(((a)->s6_addr[12]) == (m)[4]) && \
(((a)->s6_addr[13]) == (m)[5]) && \
(((a)->s6_addr[14]) == (m)[6]) && \
(((a)->s6_addr[15]) == (m)[7]))
/* check whether we can compress the IID to 16 bits,
* it's possible for unicast addresses with first 49 bits are zero only.
*/
#define lowpan_is_iid_16_bit_compressable(a) \
((((a)->s6_addr16[4]) == 0) && \
(((a)->s6_addr[10]) == 0) && \
(((a)->s6_addr[11]) == 0xff) && \
(((a)->s6_addr[12]) == 0xfe) && \
(((a)->s6_addr[13]) == 0))
/* check whether the 112-bit gid of the multicast address is mappable to: */
/* 48 bits, FFXX::00XX:XXXX:XXXX */
#define lowpan_is_mcast_addr_compressable48(a) \
((((a)->s6_addr16[1]) == 0) && \
(((a)->s6_addr16[2]) == 0) && \
(((a)->s6_addr16[3]) == 0) && \
(((a)->s6_addr16[4]) == 0) && \
(((a)->s6_addr[10]) == 0))
/* 32 bits, FFXX::00XX:XXXX */
#define lowpan_is_mcast_addr_compressable32(a) \
((((a)->s6_addr16[1]) == 0) && \
(((a)->s6_addr16[2]) == 0) && \
(((a)->s6_addr16[3]) == 0) && \
(((a)->s6_addr16[4]) == 0) && \
(((a)->s6_addr16[5]) == 0) && \
(((a)->s6_addr[12]) == 0))
/* 8 bits, FF02::00XX */
#define lowpan_is_mcast_addr_compressable8(a) \
((((a)->s6_addr[1]) == 2) && \
(((a)->s6_addr16[1]) == 0) && \
(((a)->s6_addr16[2]) == 0) && \
(((a)->s6_addr16[3]) == 0) && \
(((a)->s6_addr16[4]) == 0) && \
(((a)->s6_addr16[5]) == 0) && \
(((a)->s6_addr16[6]) == 0) && \
(((a)->s6_addr[14]) == 0))
#define LOWPAN_IPHC_CID_DCI(cid) (cid & 0x0f)
#define LOWPAN_IPHC_CID_SCI(cid) ((cid & 0xf0) >> 4)
static inline void iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
const void *lladdr)
{
/* fe:80::XXXX:XXXX:XXXX:XXXX
* \_________________/
* hwaddr
*/
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
/* second bit-flip (Universe/Local)
* is done according RFC2464
*/
ipaddr->s6_addr[8] ^= 0x02;
}
static inline void iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr,
const void *lladdr)
{
const struct ieee802154_addr *addr = lladdr;
u8 eui64[EUI64_ADDR_LEN] = { };
switch (addr->mode) {
case IEEE802154_ADDR_LONG:
ieee802154_le64_to_be64(eui64, &addr->extended_addr);
iphc_uncompress_eui64_lladdr(ipaddr, eui64);
break;
case IEEE802154_ADDR_SHORT:
/* fe:80::ff:fe00:XXXX
* \__/
* short_addr
*
* Universe/Local bit is zero.
*/
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
ipaddr->s6_addr[11] = 0xFF;
ipaddr->s6_addr[12] = 0xFE;
ieee802154_le16_to_be16(&ipaddr->s6_addr16[7],
&addr->short_addr);
break;
default:
/* should never handled and filtered by 802154 6lowpan */
WARN_ON_ONCE(1);
break;
}
}
static struct lowpan_iphc_ctx *
lowpan_iphc_ctx_get_by_id(const struct net_device *dev, u8 id)
{
struct lowpan_iphc_ctx *ret = &lowpan_priv(dev)->ctx.table[id];
if (!lowpan_iphc_ctx_is_active(ret))
return NULL;
return ret;
}
static struct lowpan_iphc_ctx *
lowpan_iphc_ctx_get_by_addr(const struct net_device *dev,
const struct in6_addr *addr)
{
struct lowpan_iphc_ctx *table = lowpan_priv(dev)->ctx.table;
struct lowpan_iphc_ctx *ret = NULL;
struct in6_addr addr_pfx;
u8 addr_plen;
int i;
for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
/* Check if context is valid. A context that is not valid
* MUST NOT be used for compression.
*/
if (!lowpan_iphc_ctx_is_active(&table[i]) ||
!lowpan_iphc_ctx_is_compression(&table[i]))
continue;
ipv6_addr_prefix(&addr_pfx, addr, table[i].plen);
/* if prefix len < 64, the remaining bits until 64th bit is
* zero. Otherwise we use table[i]->plen.
*/
if (table[i].plen < 64)
addr_plen = 64;
else
addr_plen = table[i].plen;
if (ipv6_prefix_equal(&addr_pfx, &table[i].pfx, addr_plen)) {
/* remember first match */
if (!ret) {
ret = &table[i];
continue;
}
/* get the context with longest prefix len */
if (table[i].plen > ret->plen)
ret = &table[i];
}
}
return ret;
}
static struct lowpan_iphc_ctx *
lowpan_iphc_ctx_get_by_mcast_addr(const struct net_device *dev,
const struct in6_addr *addr)
{
struct lowpan_iphc_ctx *table = lowpan_priv(dev)->ctx.table;
struct lowpan_iphc_ctx *ret = NULL;
struct in6_addr addr_mcast, network_pfx = {};
int i;
/* init mcast address with */
memcpy(&addr_mcast, addr, sizeof(*addr));
for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
/* Check if context is valid. A context that is not valid
* MUST NOT be used for compression.
*/
if (!lowpan_iphc_ctx_is_active(&table[i]) ||
!lowpan_iphc_ctx_is_compression(&table[i]))
continue;
/* setting plen */
addr_mcast.s6_addr[3] = table[i].plen;
/* get network prefix to copy into multicast address */
ipv6_addr_prefix(&network_pfx, &table[i].pfx,
table[i].plen);
/* setting network prefix */
memcpy(&addr_mcast.s6_addr[4], &network_pfx, 8);
if (ipv6_addr_equal(addr, &addr_mcast)) {
ret = &table[i];
break;
}
}
return ret;
}
/* Uncompress address function for source and
* destination address(non-multicast).
*
* address_mode is the masked value for sam or dam value
*/
static int uncompress_addr(struct sk_buff *skb, const struct net_device *dev,
struct in6_addr *ipaddr, u8 address_mode,
const void *lladdr)
{
bool fail;
switch (address_mode) {
/* SAM and DAM are the same here */
case LOWPAN_IPHC_DAM_00:
/* for global link addresses */
fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
break;
case LOWPAN_IPHC_SAM_01:
case LOWPAN_IPHC_DAM_01:
/* fe:80::XXXX:XXXX:XXXX:XXXX */
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
break;
case LOWPAN_IPHC_SAM_10:
case LOWPAN_IPHC_DAM_10:
/* fe:80::ff:fe00:XXXX */
ipaddr->s6_addr[0] = 0xFE;
ipaddr->s6_addr[1] = 0x80;
ipaddr->s6_addr[11] = 0xFF;
ipaddr->s6_addr[12] = 0xFE;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
break;
case LOWPAN_IPHC_SAM_11:
case LOWPAN_IPHC_DAM_11:
fail = false;
switch (lowpan_priv(dev)->lltype) {
case LOWPAN_LLTYPE_IEEE802154:
iphc_uncompress_802154_lladdr(ipaddr, lladdr);
break;
default:
iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
break;
}
break;
default:
pr_debug("Invalid address mode value: 0x%x\n", address_mode);
return -EINVAL;
}
if (fail) {
pr_debug("Failed to fetch skb data\n");
return -EIO;
}
raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
ipaddr->s6_addr, 16);
return 0;
}
/* Uncompress address function for source context
* based address(non-multicast).
*/
static int uncompress_ctx_addr(struct sk_buff *skb,
const struct net_device *dev,
const struct lowpan_iphc_ctx *ctx,
struct in6_addr *ipaddr, u8 address_mode,
const void *lladdr)
{
bool fail;
switch (address_mode) {
/* SAM and DAM are the same here */
case LOWPAN_IPHC_DAM_00:
fail = false;
/* SAM_00 -> unspec address ::
* Do nothing, address is already ::
*
* DAM 00 -> reserved should never occur.
*/
break;
case LOWPAN_IPHC_SAM_01:
case LOWPAN_IPHC_DAM_01:
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
break;
case LOWPAN_IPHC_SAM_10:
case LOWPAN_IPHC_DAM_10:
ipaddr->s6_addr[11] = 0xFF;
ipaddr->s6_addr[12] = 0xFE;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
break;
case LOWPAN_IPHC_SAM_11:
case LOWPAN_IPHC_DAM_11:
fail = false;
switch (lowpan_priv(dev)->lltype) {
case LOWPAN_LLTYPE_IEEE802154:
iphc_uncompress_802154_lladdr(ipaddr, lladdr);
break;
default:
iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
break;
}
ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
break;
default:
pr_debug("Invalid sam value: 0x%x\n", address_mode);
return -EINVAL;
}
if (fail) {
pr_debug("Failed to fetch skb data\n");
return -EIO;
}
raw_dump_inline(NULL,
"Reconstructed context based ipv6 src addr is",
ipaddr->s6_addr, 16);
return 0;
}
/* Uncompress function for multicast destination address,
* when M bit is set.
*/
static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
struct in6_addr *ipaddr,
u8 address_mode)
{
bool fail;
switch (address_mode) {
case LOWPAN_IPHC_DAM_00:
/* 00: 128 bits. The full address
* is carried in-line.
*/
fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
break;
case LOWPAN_IPHC_DAM_01:
/* 01: 48 bits. The address takes
* the form ffXX::00XX:XXXX:XXXX.
*/
ipaddr->s6_addr[0] = 0xFF;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
break;
case LOWPAN_IPHC_DAM_10:
/* 10: 32 bits. The address takes
* the form ffXX::00XX:XXXX.
*/
ipaddr->s6_addr[0] = 0xFF;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
break;
case LOWPAN_IPHC_DAM_11:
/* 11: 8 bits. The address takes
* the form ff02::00XX.
*/
ipaddr->s6_addr[0] = 0xFF;
ipaddr->s6_addr[1] = 0x02;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
break;
default:
pr_debug("DAM value has a wrong value: 0x%x\n", address_mode);
return -EINVAL;
}
if (fail) {
pr_debug("Failed to fetch skb data\n");
return -EIO;
}
raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
ipaddr->s6_addr, 16);
return 0;
}
static int lowpan_uncompress_multicast_ctx_daddr(struct sk_buff *skb,
struct lowpan_iphc_ctx *ctx,
struct in6_addr *ipaddr,
u8 address_mode)
{
struct in6_addr network_pfx = {};
bool fail;
ipaddr->s6_addr[0] = 0xFF;
fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 2);
fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[12], 4);
if (fail)
return -EIO;
/* take prefix_len and network prefix from the context */
ipaddr->s6_addr[3] = ctx->plen;
/* get network prefix to copy into multicast address */
ipv6_addr_prefix(&network_pfx, &ctx->pfx, ctx->plen);
/* setting network prefix */
memcpy(&ipaddr->s6_addr[4], &network_pfx, 8);
return 0;
}
/* get the ecn values from iphc tf format and set it to ipv6hdr */
static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf)
{
/* get the two higher bits which is ecn */
u8 ecn = tf[0] & 0xc0;
/* ECN takes 0x30 in hdr->flow_lbl[0] */
hdr->flow_lbl[0] |= (ecn >> 2);
}
/* get the dscp values from iphc tf format and set it to ipv6hdr */
static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf)
{
/* DSCP is at place after ECN */
u8 dscp = tf[0] & 0x3f;
/* The four highest bits need to be set at hdr->priority */
hdr->priority |= ((dscp & 0x3c) >> 2);
/* The two lower bits is part of hdr->flow_lbl[0] */
hdr->flow_lbl[0] |= ((dscp & 0x03) << 6);
}
/* get the flow label values from iphc tf format and set it to ipv6hdr */
static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl)
{
/* flow label is always some array started with lower nibble of
* flow_lbl[0] and followed with two bytes afterwards. Inside inline
* data the flow_lbl position can be different, which will be handled
* by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit
* shifted, the different lbl pointer will handle that.
*
* The flow label will started at lower nibble of flow_lbl[0], the
* higher nibbles are part of DSCP + ECN.
*/
hdr->flow_lbl[0] |= lbl[0] & 0x0f;
memcpy(&hdr->flow_lbl[1], &lbl[1], 2);
}
/* lowpan_iphc_tf_decompress - decompress the traffic class.
* This function will return zero on success, a value lower than zero if
* failed.
*/
static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr,
u8 val)
{
u8 tf[4];
/* Traffic Class and Flow Label */
switch (val) {
case LOWPAN_IPHC_TF_00:
/* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */
if (lowpan_fetch_skb(skb, tf, 4))
return -EINVAL;
/* 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |ECN| DSCP | rsv | Flow Label |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
lowpan_iphc_tf_set_ecn(hdr, tf);
lowpan_iphc_tf_set_dscp(hdr, tf);
lowpan_iphc_tf_set_lbl(hdr, &tf[1]);
break;
case LOWPAN_IPHC_TF_01:
/* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */
if (lowpan_fetch_skb(skb, tf, 3))
return -EINVAL;
/* 1 2
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |ECN|rsv| Flow Label |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
lowpan_iphc_tf_set_ecn(hdr, tf);
lowpan_iphc_tf_set_lbl(hdr, &tf[0]);
break;
case LOWPAN_IPHC_TF_10:
/* ECN + DSCP (1 byte), Flow Label is elided. */
if (lowpan_fetch_skb(skb, tf, 1))
return -EINVAL;
/* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* |ECN| DSCP |
* +-+-+-+-+-+-+-+-+
*/
lowpan_iphc_tf_set_ecn(hdr, tf);
lowpan_iphc_tf_set_dscp(hdr, tf);
break;
case LOWPAN_IPHC_TF_11:
/* Traffic Class and Flow Label are elided */
break;
default:
WARN_ON_ONCE(1);
return -EINVAL;
}
return 0;
}
/* TTL uncompression values */
static const u8 lowpan_ttl_values[] = {
[LOWPAN_IPHC_HLIM_01] = 1,
[LOWPAN_IPHC_HLIM_10] = 64,
[LOWPAN_IPHC_HLIM_11] = 255,
};
int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
const void *daddr, const void *saddr)
{
struct ipv6hdr hdr = {};
struct lowpan_iphc_ctx *ci;
u8 iphc0, iphc1, cid = 0;
int err;
raw_dump_table(__func__, "raw skb data dump uncompressed",
skb->data, skb->len);
if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) ||
lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1)))
return -EINVAL;
hdr.version = 6;
/* default CID = 0, another if the CID flag is set */
if (iphc1 & LOWPAN_IPHC_CID) {
if (lowpan_fetch_skb(skb, &cid, sizeof(cid)))
return -EINVAL;
}
err = lowpan_iphc_tf_decompress(skb, &hdr,
iphc0 & LOWPAN_IPHC_TF_MASK);
if (err < 0)
return err;
/* Next Header */
if (!(iphc0 & LOWPAN_IPHC_NH)) {
/* Next header is carried inline */
if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
return -EINVAL;
pr_debug("NH flag is set, next header carried inline: %02x\n",
hdr.nexthdr);
}
/* Hop Limit */
if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) {
hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK];
} else {
if (lowpan_fetch_skb(skb, &hdr.hop_limit,
sizeof(hdr.hop_limit)))
return -EINVAL;
}
if (iphc1 & LOWPAN_IPHC_SAC) {
spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_SCI(cid));
if (!ci) {
spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
return -EINVAL;
}
pr_debug("SAC bit is set. Handle context based source address.\n");
err = uncompress_ctx_addr(skb, dev, ci, &hdr.saddr,
iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
} else {
/* Source address uncompression */
pr_debug("source address stateless compression\n");
err = uncompress_addr(skb, dev, &hdr.saddr,
iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
}
/* Check on error of previous branch */
if (err)
return -EINVAL;
switch (iphc1 & (LOWPAN_IPHC_M | LOWPAN_IPHC_DAC)) {
case LOWPAN_IPHC_M | LOWPAN_IPHC_DAC:
spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
if (!ci) {
spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
return -EINVAL;
}
/* multicast with context */
pr_debug("dest: context-based mcast compression\n");
err = lowpan_uncompress_multicast_ctx_daddr(skb, ci,
&hdr.daddr,
iphc1 & LOWPAN_IPHC_DAM_MASK);
spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
break;
case LOWPAN_IPHC_M:
/* multicast */
err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr,
iphc1 & LOWPAN_IPHC_DAM_MASK);
break;
case LOWPAN_IPHC_DAC:
spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
if (!ci) {
spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
return -EINVAL;
}
/* Destination address context based uncompression */
pr_debug("DAC bit is set. Handle context based destination address.\n");
err = uncompress_ctx_addr(skb, dev, ci, &hdr.daddr,
iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
break;
default:
err = uncompress_addr(skb, dev, &hdr.daddr,
iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
pr_debug("dest: stateless compression mode %d dest %pI6c\n",
iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr);
break;
}
if (err)
return -EINVAL;
/* Next header data uncompression */
if (iphc0 & LOWPAN_IPHC_NH) {
err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
if (err < 0)
return err;
} else {
err = skb_cow(skb, sizeof(hdr));
if (unlikely(err))
return err;
}
switch (lowpan_priv(dev)->lltype) {
case LOWPAN_LLTYPE_IEEE802154:
if (lowpan_802154_cb(skb)->d_size)
hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size -
sizeof(struct ipv6hdr));
else
hdr.payload_len = htons(skb->len);
break;
default:
hdr.payload_len = htons(skb->len);
break;
}
pr_debug("skb headroom size = %d, data length = %d\n",
skb_headroom(skb), skb->len);
pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
"nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
hdr.hop_limit, &hdr.daddr);
skb_push(skb, sizeof(hdr));
skb_reset_network_header(skb);
skb_copy_to_linear_data(skb, &hdr, sizeof(hdr));
raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr));
return 0;
}
EXPORT_SYMBOL_GPL(lowpan_header_decompress);
static const u8 lowpan_iphc_dam_to_sam_value[] = {
[LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00,
[LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01,
[LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10,
[LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11,
};
static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct in6_addr *ipaddr,
const struct lowpan_iphc_ctx *ctx,
const unsigned char *lladdr, bool sam)
{
struct in6_addr tmp = {};
u8 dam;
/* check for SAM/DAM = 11 */
memcpy(&tmp.s6_addr[8], lladdr, 8);
/* second bit-flip (Universe/Local) is done according RFC2464 */
tmp.s6_addr[8] ^= 0x02;
/* context information are always used */
ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
if (ipv6_addr_equal(&tmp, ipaddr)) {
dam = LOWPAN_IPHC_DAM_11;
goto out;
}
memset(&tmp, 0, sizeof(tmp));
/* check for SAM/DAM = 10 */
tmp.s6_addr[11] = 0xFF;
tmp.s6_addr[12] = 0xFE;
memcpy(&tmp.s6_addr[14], &ipaddr->s6_addr[14], 2);
/* context information are always used */
ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
if (ipv6_addr_equal(&tmp, ipaddr)) {
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[14], 2);
dam = LOWPAN_IPHC_DAM_10;
goto out;
}
memset(&tmp, 0, sizeof(tmp));
/* check for SAM/DAM = 01, should always match */
memcpy(&tmp.s6_addr[8], &ipaddr->s6_addr[8], 8);
/* context information are always used */
ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
if (ipv6_addr_equal(&tmp, ipaddr)) {
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[8], 8);
dam = LOWPAN_IPHC_DAM_01;
goto out;
}
WARN_ONCE(1, "context found but no address mode matched\n");
return LOWPAN_IPHC_DAM_00;
out:
if (sam)
return lowpan_iphc_dam_to_sam_value[dam];
else
return dam;
}
static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr,
const unsigned char *lladdr, bool sam)
{
u8 dam = LOWPAN_IPHC_DAM_00;
if (is_addr_mac_addr_based(ipaddr, lladdr)) {
dam = LOWPAN_IPHC_DAM_11; /* 0-bits */
pr_debug("address compression 0 bits\n");
} else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
/* compress IID to 16 bits xxxx::XXXX */
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
dam = LOWPAN_IPHC_DAM_10; /* 16-bits */
raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
*hc_ptr - 2, 2);
} else {
/* do not compress IID => xxxx::IID */
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
dam = LOWPAN_IPHC_DAM_01; /* 64-bits */
raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
*hc_ptr - 8, 8);
}
if (sam)
return lowpan_iphc_dam_to_sam_value[dam];
else
return dam;
}
/* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */
static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr)
{
u8 dscp, ecn;
/* hdr->priority contains the higher bits of dscp, lower are part of
* flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr.
*/
dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6);
/* ECN is at the two lower bits from first nibble of flow_lbl[0] */
ecn = (hdr->flow_lbl[0] & 0x30);
/* for pretty debug output, also shift ecn to get the ecn value */
pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp);
/* ECN is at 0x30 now, shift it to have ECN + DCSP */
return (ecn << 2) | dscp;
}
/* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */
static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr)
{
return ((!(hdr->flow_lbl[0] & 0x0f)) &&
!hdr->flow_lbl[1] && !hdr->flow_lbl[2]);
}
/* lowpan_iphc_tf_compress - compress the traffic class which is set by
* ipv6hdr. Return the corresponding format identifier which is used.
*/
static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr)
{
/* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */
u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val;
/* printout the traffic class in hc format */
pr_debug("tc 0x%02x\n", tc);
if (lowpan_iphc_is_flow_lbl_zero(hdr)) {
if (!tc) {
/* 11: Traffic Class and Flow Label are elided. */
val = LOWPAN_IPHC_TF_11;
} else {
/* 10: ECN + DSCP (1 byte), Flow Label is elided.
*
* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* |ECN| DSCP |
* +-+-+-+-+-+-+-+-+
*/
lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc));
val = LOWPAN_IPHC_TF_10;
}
} else {
/* check if dscp is zero, it's after the first two bit */
if (!(tc & 0x3f)) {
/* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
*
* 1 2
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |ECN|rsv| Flow Label |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
memcpy(&tf[0], &hdr->flow_lbl[0], 3);
/* zero the highest 4-bits, contains DCSP + ECN */
tf[0] &= ~0xf0;
/* set ECN */
tf[0] |= (tc & 0xc0);
lowpan_push_hc_data(hc_ptr, tf, 3);
val = LOWPAN_IPHC_TF_01;
} else {
/* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
*
* 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |ECN| DSCP | rsv | Flow Label |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
memcpy(&tf[0], &tc, sizeof(tc));
/* highest nibble of flow_lbl[0] is part of DSCP + ECN
* which will be the 4-bit pad and will be filled with
* zeros afterwards.
*/
memcpy(&tf[1], &hdr->flow_lbl[0], 3);
/* zero the 4-bit pad, which is reserved */
tf[1] &= ~0xf0;
lowpan_push_hc_data(hc_ptr, tf, 4);
val = LOWPAN_IPHC_TF_00;
}
}
return val;
}
static u8 lowpan_iphc_mcast_ctx_addr_compress(u8 **hc_ptr,
const struct lowpan_iphc_ctx *ctx,
const struct in6_addr *ipaddr)
{
u8 data[6];
/* flags/scope, reserved (RIID) */
memcpy(data, &ipaddr->s6_addr[1], 2);
/* group ID */
memcpy(&data[1], &ipaddr->s6_addr[11], 4);
lowpan_push_hc_data(hc_ptr, data, 6);
return LOWPAN_IPHC_DAM_00;
}
static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr,
const struct in6_addr *ipaddr)
{
u8 val;
if (lowpan_is_mcast_addr_compressable8(ipaddr)) {
pr_debug("compressed to 1 octet\n");
/* use last byte */
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1);
val = LOWPAN_IPHC_DAM_11;
} else if (lowpan_is_mcast_addr_compressable32(ipaddr)) {
pr_debug("compressed to 4 octets\n");
/* second byte + the last three */
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3);
val = LOWPAN_IPHC_DAM_10;
} else if (lowpan_is_mcast_addr_compressable48(ipaddr)) {
pr_debug("compressed to 6 octets\n");
/* second byte + the last five */
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5);
val = LOWPAN_IPHC_DAM_01;
} else {
pr_debug("using full address\n");
lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16);
val = LOWPAN_IPHC_DAM_00;
}
return val;
}
int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
const void *daddr, const void *saddr)
{
u8 iphc0, iphc1, *hc_ptr, cid = 0;
struct ipv6hdr *hdr;
u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {};
struct lowpan_iphc_ctx *dci, *sci, dci_entry, sci_entry;
int ret, ipv6_daddr_type, ipv6_saddr_type;