/
ah_input.c
1092 lines (987 loc) · 26.3 KB
/
ah_input.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
/* $NetBSD: ah_input.c,v 1.26.2.8 2002/09/17 21:23:11 nathanw Exp $ */
/* $KAME: ah_input.c,v 1.64 2001/09/04 08:43:19 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* 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 project 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 PROJECT 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 PROJECT 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.
*/
/*
* RFC1826/2402 authentication header.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ah_input.c,v 1.26.2.8 2002/09/17 21:23:11 nathanw Exp $");
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <machine/cpu.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip6.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/ip6protosw.h>
#endif
#include <netinet6/ipsec.h>
#include <netinet6/ah.h>
#include <netkey/key.h>
#include <netkey/keydb.h>
#include <netkey/key_debug.h>
#include <machine/stdarg.h>
#include <net/net_osdep.h>
/*#define IPLEN_FLIPPED*/
#ifdef INET
void
#if __STDC__
ah4_input(struct mbuf *m, ...)
#else
ah4_input(m, va_alist)
struct mbuf *m;
va_dcl
#endif
{
struct ip *ip;
struct ah *ah;
u_int32_t spi;
const struct ah_algorithm *algo;
size_t siz;
size_t siz1;
u_int8_t cksum[AH_MAXSUMSIZE];
struct secasvar *sav = NULL;
u_int16_t nxt;
size_t hlen;
int s;
int off, proto;
va_list ap;
size_t stripsiz = 0;
va_start(ap, m);
off = va_arg(ap, int);
proto = va_arg(ap, int);
va_end(ap);
#ifndef PULLDOWN_TEST
if (m->m_len < off + sizeof(struct newah)) {
m = m_pullup(m, off + sizeof(struct newah));
if (!m) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
"dropping the packet for simplicity\n"));
ipsecstat.in_inval++;
goto fail;
}
}
ip = mtod(m, struct ip *);
ah = (struct ah *)(((caddr_t)ip) + off);
#else
ip = mtod(m, struct ip *);
IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
if (ah == NULL) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
"dropping the packet for simplicity\n"));
ipsecstat.in_inval++;
goto fail;
}
#endif
nxt = ah->ah_nxt;
#ifdef _IP_VHL
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
#else
hlen = ip->ip_hl << 2;
#endif
/* find the sassoc. */
spi = ah->ah_spi;
if ((sav = key_allocsa(AF_INET,
(caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
IPPROTO_AH, spi)) == 0) {
ipseclog((LOG_WARNING,
"IPv4 AH input: no key association found for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsecstat.in_nosa++;
goto fail;
}
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah4_input called to allocate SA:%p\n", sav));
if (sav->state != SADB_SASTATE_MATURE
&& sav->state != SADB_SASTATE_DYING) {
ipseclog((LOG_DEBUG,
"IPv4 AH input: non-mature/dying SA found for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsecstat.in_badspi++;
goto fail;
}
algo = ah_algorithm_lookup(sav->alg_auth);
if (!algo) {
ipseclog((LOG_DEBUG, "IPv4 AH input: "
"unsupported authentication algorithm for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsecstat.in_badspi++;
goto fail;
}
siz = (*algo->sumsiz)(sav);
siz1 = ((siz + 3) & ~(4 - 1));
/*
* sanity checks for header, 1.
*/
{
int sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
/*
* Here, we do not do "siz1 == siz". This is because the way
* RFC240[34] section 2 is written. They do not require truncation
* to 96 bits.
* For example, Microsoft IPsec stack attaches 160 bits of
* authentication data for both hmac-md5 and hmac-sha1. For hmac-sha1,
* 32 bits of padding is attached.
*
* There are two downsides to this specification.
* They have no real harm, however, they leave us fuzzy feeling.
* - if we attach more than 96 bits of authentication data onto AH,
* we will never notice about possible modification by rogue
* intermediate nodes.
* Since extra bits in AH checksum is never used, this constitutes
* no real issue, however, it is wacky.
* - even if the peer attaches big authentication data, we will never
* notice the difference, since longer authentication data will just
* work.
*
* We may need some clarification in the spec.
*/
if (siz1 < siz) {
ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
"(%lu, should be at least %lu): %s\n",
(u_long)siz1, (u_long)siz,
ipsec4_logpacketstr(ip, spi)));
ipsecstat.in_inval++;
goto fail;
}
if ((ah->ah_len << 2) - sizoff != siz1) {
ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
"(%d should be %lu): %s\n",
(ah->ah_len << 2) - sizoff, (u_long)siz1,
ipsec4_logpacketstr(ip, spi)));
ipsecstat.in_inval++;
goto fail;
}
if (siz1 > sizeof(cksum)) {
ipseclog((LOG_NOTICE, "sum length too large: %s\n",
ipsec4_logpacketstr(ip, spi)));
ipsecstat.in_inval++;
goto fail;
}
#ifndef PULLDOWN_TEST
if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
if (!m) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
ipsecstat.in_inval++;
goto fail;
}
ip = mtod(m, struct ip *);
ah = (struct ah *)(((caddr_t)ip) + off);
}
#else
IP6_EXTHDR_GET(ah, struct ah *, m, off,
sizeof(struct ah) + sizoff + siz1);
if (ah == NULL) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
ipsecstat.in_inval++;
goto fail;
}
#endif
}
/*
* check for sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
; /* okey */
else {
ipsecstat.in_ahreplay++;
ipseclog((LOG_WARNING,
"replay packet in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
goto fail;
}
}
/*
* alright, it seems sane. now we are going to check the
* cryptographic checksum.
*/
{
#if 0
/*
* some of IP header fields are flipped to the host endian.
* convert them back to network endian. VERY stupid.
*/
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
#endif
if (ah4_calccksum(m, cksum, siz1, algo, sav)) {
ipsecstat.in_inval++;
goto fail;
}
ipsecstat.in_ahhist[sav->alg_auth]++;
#if 0
/*
* flip them back.
*/
ip->ip_len = ntohs(ip->ip_len);
ip->ip_off = ntohs(ip->ip_off);
#endif
}
{
caddr_t sumpos = NULL;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
sumpos = (caddr_t)(ah + 1);
} else {
/* RFC 2402 */
sumpos = (caddr_t)(((struct newah *)ah) + 1);
}
if (bcmp(sumpos, cksum, siz) != 0) {
ipseclog((LOG_WARNING,
"checksum mismatch in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
ipsecstat.in_ahauthfail++;
goto fail;
}
}
m->m_flags |= M_AUTHIPHDR;
m->m_flags |= M_AUTHIPDGM;
#if 0
/*
* looks okey, but we need more sanity check.
* XXX should elaborate.
*/
if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
struct ip *nip;
size_t sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
m = m_pullup(m, off + sizeof(struct ah)
+ sizoff + siz1 + hlen);
if (!m) {
ipseclog((LOG_DEBUG,
"IPv4 AH input: can't pullup\n"));
ipsecstat.in_inval++;
goto fail;
}
}
nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
if (nip->ip_src.s_addr != ip->ip_src.s_addr
|| nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
}
#ifdef INET6
else if (ah->ah_nxt == IPPROTO_IPV6) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
#endif /* INET6 */
#endif /* 0 */
if (m->m_flags & M_AUTHIPHDR
&& m->m_flags & M_AUTHIPDGM) {
#if 0
ipseclog((LOG_DEBUG,
"IPv4 AH input: authentication succeess\n"));
#endif
ipsecstat.in_ahauthsucc++;
} else {
ipseclog((LOG_WARNING,
"authentication failed in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
ipsecstat.in_ahauthfail++;
goto fail;
}
/*
* update sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
ipsecstat.in_ahreplay++;
goto fail;
}
}
/* was it transmitted over the IPsec tunnel SA? */
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
stripsiz = sizeof(struct ah) + siz1;
} else {
/* RFC 2402 */
stripsiz = sizeof(struct newah) + siz1;
}
if (ipsec4_tunnel_validate(ip, nxt, sav)) {
/*
* strip off all the headers that precedes AH.
* IP xx AH IP' payload -> IP' payload
*
* XXX more sanity checks
* XXX relationship with gif?
*/
u_int8_t tos;
tos = ip->ip_tos;
m_adj(m, off + stripsiz);
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m) {
ipsecstat.in_inval++;
goto fail;
}
}
ip = mtod(m, struct ip *);
/* ECN consideration. */
ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
if (!key_checktunnelsanity(sav, AF_INET,
(caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
"in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
ipsecstat.in_inval++;
goto fail;
}
#if 1
/*
* Should the inner packet be considered authentic?
* My current answer is: NO.
*
* host1 -- gw1 === gw2 -- host2
* In this case, gw2 can trust the authenticity of the
* outer packet, but NOT inner. Packet may be altered
* between host1 and gw1.
*
* host1 -- gw1 === host2
* This case falls into the same scenario as above.
*
* host1 === host2
* This case is the only case when we may be able to leave
* M_AUTHIPHDR and M_AUTHIPDGM set.
* However, if host1 is wrongly configured, and allows
* attacker to inject some packet with src=host1 and
* dst=host2, you are in risk.
*/
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
#endif
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
ipsecstat.in_nomem++;
goto fail;
}
s = splnet();
if (IF_QFULL(&ipintrq)) {
ipsecstat.in_inval++;
splx(s);
goto fail;
}
IF_ENQUEUE(&ipintrq, m);
m = NULL;
schednetisr(NETISR_IP); /* can be skipped but to make sure */
splx(s);
nxt = IPPROTO_DONE;
} else {
/*
* strip off AH.
*/
ip = mtod(m, struct ip *);
#ifndef PULLDOWN_TEST
/*
* We do deep-copy since KAME requires that
* the packet is placed in a single external mbuf.
*/
ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
#else
/*
* even in m_pulldown case, we need to strip off AH so that
* we can compute checksum for multiple AH correctly.
*/
if (m->m_len >= stripsiz + off) {
ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
} else {
/*
* this comes with no copy if the boundary is on
* cluster
*/
struct mbuf *n;
n = m_split(m, off, M_DONTWAIT);
if (n == NULL) {
/* m is retained by m_split */
goto fail;
}
m_adj(n, stripsiz);
m_cat(m, n);
/* m_cat does not update m_pkthdr.len */
m->m_pkthdr.len += n->m_pkthdr.len;
}
#endif
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (m == NULL) {
ipsecstat.in_inval++;
goto fail;
}
}
ip = mtod(m, struct ip *);
#ifdef IPLEN_FLIPPED
ip->ip_len = ip->ip_len - stripsiz;
#else
ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
#endif
ip->ip_p = nxt;
/* forget about IP hdr checksum, the check has already been passed */
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
ipsecstat.in_nomem++;
goto fail;
}
if (nxt != IPPROTO_DONE) {
if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
ipsec4_in_reject(m, NULL)) {
ipsecstat.in_polvio++;
goto fail;
}
(*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
} else
m_freem(m);
m = NULL;
}
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah4_input call free SA:%p\n", sav));
key_freesav(sav);
}
ipsecstat.in_success++;
return;
fail:
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah4_input call free SA:%p\n", sav));
key_freesav(sav);
}
if (m)
m_freem(m);
return;
}
/* assumes that ip header and ah header are contiguous on mbuf */
void *
ah4_ctlinput(cmd, sa, v)
int cmd;
struct sockaddr *sa;
void *v;
{
struct ip *ip = v;
struct ah *ah;
struct icmp *icp;
struct secasvar *sav;
if (sa->sa_family != AF_INET ||
sa->sa_len != sizeof(struct sockaddr_in))
return NULL;
if ((unsigned)cmd >= PRC_NCMDS)
return NULL;
if (cmd == PRC_MSGSIZE && ip_mtudisc && ip && ip->ip_v == 4) {
/*
* Check to see if we have a valid SA corresponding to
* the address in the ICMP message payload.
*/
ah = (struct ah *)((caddr_t)ip + (ip->ip_hl << 2));
if ((sav = key_allocsa(AF_INET,
(caddr_t) &ip->ip_src,
(caddr_t) &ip->ip_dst,
IPPROTO_AH, ah->ah_spi)) == NULL)
return NULL;
if (sav->state != SADB_SASTATE_MATURE &&
sav->state != SADB_SASTATE_DYING) {
key_freesav(sav);
return NULL;
}
/* XXX Further validation? */
key_freesav(sav);
/*
* Now that we've validated that we are actually communicating
* with the host indicated in the ICMP message, locate the
* ICMP header, recalculate the new MTU, and create the
* corresponding routing entry.
*/
icp = (struct icmp *)((caddr_t)ip -
offsetof(struct icmp, icmp_ip));
icmp_mtudisc(icp, ip->ip_dst);
return NULL;
}
return NULL;
}
#endif /* INET */
#ifdef INET6
int
ah6_input(mp, offp, proto)
struct mbuf **mp;
int *offp, proto;
{
struct mbuf *m = *mp;
int off = *offp;
struct ip6_hdr *ip6;
struct ah *ah;
u_int32_t spi;
const struct ah_algorithm *algo;
size_t siz;
size_t siz1;
u_int8_t cksum[AH_MAXSUMSIZE];
struct secasvar *sav = NULL;
u_int16_t nxt;
int s;
size_t stripsiz = 0;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
ah = (struct ah *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
if (ah == NULL) {
ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
ipsec6stat.in_inval++;
return IPPROTO_DONE;
}
#endif
ip6 = mtod(m, struct ip6_hdr *);
nxt = ah->ah_nxt;
/* find the sassoc. */
spi = ah->ah_spi;
if (ntohs(ip6->ip6_plen) == 0) {
ipseclog((LOG_ERR, "IPv6 AH input: "
"AH with IPv6 jumbogram is not supported.\n"));
ipsec6stat.in_inval++;
goto fail;
}
if ((sav = key_allocsa(AF_INET6,
(caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
IPPROTO_AH, spi)) == 0) {
ipseclog((LOG_WARNING,
"IPv6 AH input: no key association found for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsec6stat.in_nosa++;
goto fail;
}
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah6_input called to allocate SA:%p\n", sav));
if (sav->state != SADB_SASTATE_MATURE
&& sav->state != SADB_SASTATE_DYING) {
ipseclog((LOG_DEBUG,
"IPv6 AH input: non-mature/dying SA found for spi %u; ",
(u_int32_t)ntohl(spi)));
ipsec6stat.in_badspi++;
goto fail;
}
algo = ah_algorithm_lookup(sav->alg_auth);
if (!algo) {
ipseclog((LOG_DEBUG, "IPv6 AH input: "
"unsupported authentication algorithm for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsec6stat.in_badspi++;
goto fail;
}
siz = (*algo->sumsiz)(sav);
siz1 = ((siz + 3) & ~(4 - 1));
/*
* sanity checks for header, 1.
*/
{
int sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
/*
* Here, we do not do "siz1 == siz". See ah4_input() for complete
* description.
*/
if (siz1 < siz) {
ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
"(%lu, should be at least %lu): %s\n",
(u_long)siz1, (u_long)siz,
ipsec6_logpacketstr(ip6, spi)));
ipsec6stat.in_inval++;
goto fail;
}
if ((ah->ah_len << 2) - sizoff != siz1) {
ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
"(%d should be %lu): %s\n",
(ah->ah_len << 2) - sizoff, (u_long)siz1,
ipsec6_logpacketstr(ip6, spi)));
ipsec6stat.in_inval++;
goto fail;
}
if (siz1 > sizeof(cksum)) {
ipseclog((LOG_NOTICE, "sum length too large: %s\n",
ipsec6_logpacketstr(ip6, spi)));
ipsec6stat.in_inval++;
goto fail;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
#else
IP6_EXTHDR_GET(ah, struct ah *, m, off,
sizeof(struct ah) + sizoff + siz1);
if (ah == NULL) {
ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
ipsec6stat.in_inval++;
m = NULL;
goto fail;
}
#endif
}
/*
* check for sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
; /* okey */
else {
ipsec6stat.in_ahreplay++;
ipseclog((LOG_WARNING,
"replay packet in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi),
ipsec_logsastr(sav)));
goto fail;
}
}
/*
* alright, it seems sane. now we are going to check the
* cryptographic checksum.
*/
if (ah6_calccksum(m, cksum, siz1, algo, sav)) {
ipsec6stat.in_inval++;
goto fail;
}
ipsec6stat.in_ahhist[sav->alg_auth]++;
{
caddr_t sumpos = NULL;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
sumpos = (caddr_t)(ah + 1);
} else {
/* RFC 2402 */
sumpos = (caddr_t)(((struct newah *)ah) + 1);
}
if (bcmp(sumpos, cksum, siz) != 0) {
ipseclog((LOG_WARNING,
"checksum mismatch in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
ipsec6stat.in_ahauthfail++;
goto fail;
}
}
m->m_flags |= M_AUTHIPHDR;
m->m_flags |= M_AUTHIPDGM;
#if 0
/*
* looks okey, but we need more sanity check.
* XXX should elaborate.
*/
if (ah->ah_nxt == IPPROTO_IPV6) {
struct ip6_hdr *nip6;
size_t sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
+ sizeof(struct ip6_hdr), IPPROTO_DONE);
nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
|| !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
} else if (ah->ah_nxt == IPPROTO_IPIP) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
} else if (ah->ah_nxt == IPPROTO_IP) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
#endif
if (m->m_flags & M_AUTHIPHDR
&& m->m_flags & M_AUTHIPDGM) {
#if 0
ipseclog((LOG_DEBUG,
"IPv6 AH input: authentication succeess\n"));
#endif
ipsec6stat.in_ahauthsucc++;
} else {
ipseclog((LOG_WARNING,
"authentication failed in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
ipsec6stat.in_ahauthfail++;
goto fail;
}
/*
* update sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
ipsec6stat.in_ahreplay++;
goto fail;
}
}
/* was it transmitted over the IPsec tunnel SA? */
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
stripsiz = sizeof(struct ah) + siz1;
} else {
/* RFC 2402 */
stripsiz = sizeof(struct newah) + siz1;
}
if (ipsec6_tunnel_validate(ip6, nxt, sav)) {
/*
* strip off all the headers that precedes AH.
* IP6 xx AH IP6' payload -> IP6' payload
*
* XXX more sanity checks
* XXX relationship with gif?
*/
u_int32_t flowinfo; /* net endian */
flowinfo = ip6->ip6_flow;
m_adj(m, off + stripsiz);
if (m->m_len < sizeof(*ip6)) {
/*
* m_pullup is prohibited in KAME IPv6 input processing
* but there's no other way!
*/
m = m_pullup(m, sizeof(*ip6));
if (!m) {
ipsec6stat.in_inval++;
goto fail;
}
}
ip6 = mtod(m, struct ip6_hdr *);
/* ECN consideration. */
ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
if (!key_checktunnelsanity(sav, AF_INET6,
(caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
"in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi),
ipsec_logsastr(sav)));
ipsec6stat.in_inval++;
goto fail;
}
#if 1
/*
* should the inner packet be considered authentic?
* see comment in ah4_input().
*/
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
#endif
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
ipsec6stat.in_nomem++;
goto fail;
}
s = splnet();
if (IF_QFULL(&ip6intrq)) {
ipsec6stat.in_inval++;
splx(s);
goto fail;
}
IF_ENQUEUE(&ip6intrq, m);
m = NULL;
schednetisr(NETISR_IPV6); /* can be skipped but to make sure */
splx(s);
nxt = IPPROTO_DONE;
} else {
/*
* strip off AH.
*/
u_int8_t *prvnxtp;
/*
* Copy the value of the next header field of AH to the
* next header field of the previous header.
* This is necessary because AH will be stripped off below.
*/
prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
*prvnxtp = nxt;
ip6 = mtod(m, struct ip6_hdr *);
#ifndef PULLDOWN_TEST
/*
* We do deep-copy since KAME requires that
* the packet is placed in a single mbuf.
*/
ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
#else
/*
* even in m_pulldown case, we need to strip off AH so that
* we can compute checksum for multiple AH correctly.
*/
if (m->m_len >= stripsiz + off) {
ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
} else {
/*
* this comes with no copy if the boundary is on
* cluster
*/
struct mbuf *n;
n = m_split(m, off, M_DONTWAIT);
if (n == NULL) {
/* m is retained by m_split */
goto fail;
}
m_adj(n, stripsiz);
m_cat(m, n);
/* m_cat does not update m_pkthdr.len */
m->m_pkthdr.len += n->m_pkthdr.len;
}
#endif
ip6 = mtod(m, struct ip6_hdr *);
/* XXX jumbogram */
ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
ipsec6stat.in_nomem++;
goto fail;
}
}
*offp = off;
*mp = m;
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah6_input call free SA:%p\n", sav));
key_freesav(sav);
}
ipsec6stat.in_success++;
return nxt;
fail:
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah6_input call free SA:%p\n", sav));
key_freesav(sav);
}
if (m)
m_freem(m);
return IPPROTO_DONE;