1 /* $FreeBSD: releng/5.1/sys/netinet6/ah_input.c 111888 2003-03-04 23:19:55Z jlemon $ */
2 /* $KAME: ah_input.c,v 1.67 2002/01/07 11:39:56 kjc Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 /*
34 * RFC1826/2402 authentication header.
35 */
36
37 #include "opt_inet.h"
38 #include "opt_inet6.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/domain.h>
45 #include <sys/protosw.h>
46 #include <sys/socket.h>
47 #include <sys/errno.h>
48 #include <sys/time.h>
49 #include <sys/syslog.h>
50
51 #include <net/if.h>
52 #include <net/route.h>
53 #include <net/netisr.h>
54 #include <machine/cpu.h>
55
56 #include <netinet/in.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/in_var.h>
59 #include <netinet/ip.h>
60 #include <netinet/ip_var.h>
61 #include <netinet/ip_ecn.h>
62 #ifdef INET6
63 #include <netinet6/ip6_ecn.h>
64 #endif
65
66 #ifdef INET6
67 #include <netinet/ip6.h>
68 #include <netinet6/ip6_var.h>
69 #include <netinet/in_pcb.h>
70 #include <netinet6/in6_pcb.h>
71 #include <netinet/icmp6.h>
72 #include <netinet6/ip6protosw.h>
73 #endif
74
75 #include <netinet6/ipsec.h>
76 #ifdef INET6
77 #include <netinet6/ipsec6.h>
78 #endif
79 #include <netinet6/ah.h>
80 #ifdef INET6
81 #include <netinet6/ah6.h>
82 #endif
83 #include <netkey/key.h>
84 #include <netkey/keydb.h>
85 #ifdef IPSEC_DEBUG
86 #include <netkey/key_debug.h>
87 #else
88 #define KEYDEBUG(lev,arg)
89 #endif
90
91 #include <machine/stdarg.h>
92
93 #include <net/net_osdep.h>
94
95 #define IPLEN_FLIPPED
96
97 #ifdef INET
98 extern struct protosw inetsw[];
99
100 void
101 ah4_input(m, off)
102 struct mbuf *m;
103 int off;
104 {
105 struct ip *ip;
106 struct ah *ah;
107 u_int32_t spi;
108 const struct ah_algorithm *algo;
109 size_t siz;
110 size_t siz1;
111 u_char *cksum;
112 struct secasvar *sav = NULL;
113 u_int16_t nxt;
114 size_t hlen;
115 int proto;
116 size_t stripsiz = 0;
117
118 #ifndef PULLDOWN_TEST
119 if (m->m_len < off + sizeof(struct newah)) {
120 m = m_pullup(m, off + sizeof(struct newah));
121 if (!m) {
122 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
123 "dropping the packet for simplicity\n"));
124 ipsecstat.in_inval++;
125 goto fail;
126 }
127 }
128
129 ip = mtod(m, struct ip *);
130 proto = ip->ip_p;
131 ah = (struct ah *)(((caddr_t)ip) + off);
132 #else
133 ip = mtod(m, struct ip *);
134 proto = ip->ip_p;
135 IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
136 if (ah == NULL) {
137 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
138 "dropping the packet for simplicity\n"));
139 ipsecstat.in_inval++;
140 goto fail;
141 }
142 #endif
143 nxt = ah->ah_nxt;
144 #ifdef _IP_VHL
145 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
146 #else
147 hlen = ip->ip_hl << 2;
148 #endif
149
150 /* find the sassoc. */
151 spi = ah->ah_spi;
152
153 if ((sav = key_allocsa(AF_INET,
154 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
155 IPPROTO_AH, spi)) == 0) {
156 ipseclog((LOG_WARNING,
157 "IPv4 AH input: no key association found for spi %u\n",
158 (u_int32_t)ntohl(spi)));
159 ipsecstat.in_nosa++;
160 goto fail;
161 }
162 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
163 printf("DP ah4_input called to allocate SA:%p\n", sav));
164 if (sav->state != SADB_SASTATE_MATURE
165 && sav->state != SADB_SASTATE_DYING) {
166 ipseclog((LOG_DEBUG,
167 "IPv4 AH input: non-mature/dying SA found for spi %u\n",
168 (u_int32_t)ntohl(spi)));
169 ipsecstat.in_badspi++;
170 goto fail;
171 }
172
173 algo = ah_algorithm_lookup(sav->alg_auth);
174 if (!algo) {
175 ipseclog((LOG_DEBUG, "IPv4 AH input: "
176 "unsupported authentication algorithm for spi %u\n",
177 (u_int32_t)ntohl(spi)));
178 ipsecstat.in_badspi++;
179 goto fail;
180 }
181
182 siz = (*algo->sumsiz)(sav);
183 siz1 = ((siz + 3) & ~(4 - 1));
184
185 /*
186 * sanity checks for header, 1.
187 */
188 {
189 int sizoff;
190
191 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
192
193 /*
194 * Here, we do not do "siz1 == siz". This is because the way
195 * RFC240[34] section 2 is written. They do not require truncation
196 * to 96 bits.
197 * For example, Microsoft IPsec stack attaches 160 bits of
198 * authentication data for both hmac-md5 and hmac-sha1. For hmac-sha1,
199 * 32 bits of padding is attached.
200 *
201 * There are two downsides to this specification.
202 * They have no real harm, however, they leave us fuzzy feeling.
203 * - if we attach more than 96 bits of authentication data onto AH,
204 * we will never notice about possible modification by rogue
205 * intermediate nodes.
206 * Since extra bits in AH checksum is never used, this constitutes
207 * no real issue, however, it is wacky.
208 * - even if the peer attaches big authentication data, we will never
209 * notice the difference, since longer authentication data will just
210 * work.
211 *
212 * We may need some clarification in the spec.
213 */
214 if (siz1 < siz) {
215 ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
216 "(%lu, should be at least %lu): %s\n",
217 (u_long)siz1, (u_long)siz,
218 ipsec4_logpacketstr(ip, spi)));
219 ipsecstat.in_inval++;
220 goto fail;
221 }
222 if ((ah->ah_len << 2) - sizoff != siz1) {
223 ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
224 "(%d should be %lu): %s\n",
225 (ah->ah_len << 2) - sizoff, (u_long)siz1,
226 ipsec4_logpacketstr(ip, spi)));
227 ipsecstat.in_inval++;
228 goto fail;
229 }
230
231 #ifndef PULLDOWN_TEST
232 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
233 m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
234 if (!m) {
235 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
236 ipsecstat.in_inval++;
237 goto fail;
238 }
239
240 ip = mtod(m, struct ip *);
241 ah = (struct ah *)(((caddr_t)ip) + off);
242 }
243 #else
244 IP6_EXTHDR_GET(ah, struct ah *, m, off,
245 sizeof(struct ah) + sizoff + siz1);
246 if (ah == NULL) {
247 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
248 ipsecstat.in_inval++;
249 goto fail;
250 }
251 #endif
252 }
253
254 /*
255 * check for sequence number.
256 */
257 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
258 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
259 ; /* okey */
260 else {
261 ipsecstat.in_ahreplay++;
262 ipseclog((LOG_WARNING,
263 "replay packet in IPv4 AH input: %s %s\n",
264 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
265 goto fail;
266 }
267 }
268
269 /*
270 * alright, it seems sane. now we are going to check the
271 * cryptographic checksum.
272 */
273 cksum = malloc(siz1, M_TEMP, M_NOWAIT);
274 if (!cksum) {
275 ipseclog((LOG_DEBUG, "IPv4 AH input: "
276 "couldn't alloc temporary region for cksum\n"));
277 ipsecstat.in_inval++;
278 goto fail;
279 }
280
281 /*
282 * some of IP header fields are flipped to the host endian.
283 * convert them back to network endian. VERY stupid.
284 */
285 ip->ip_len = htons(ip->ip_len + hlen);
286 ip->ip_off = htons(ip->ip_off);
287 if (ah4_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
288 free(cksum, M_TEMP);
289 ipsecstat.in_inval++;
290 goto fail;
291 }
292 ipsecstat.in_ahhist[sav->alg_auth]++;
293 /*
294 * flip them back.
295 */
296 ip->ip_len = ntohs(ip->ip_len) - hlen;
297 ip->ip_off = ntohs(ip->ip_off);
298
299 {
300 caddr_t sumpos = NULL;
301
302 if (sav->flags & SADB_X_EXT_OLD) {
303 /* RFC 1826 */
304 sumpos = (caddr_t)(ah + 1);
305 } else {
306 /* RFC 2402 */
307 sumpos = (caddr_t)(((struct newah *)ah) + 1);
308 }
309
310 if (bcmp(sumpos, cksum, siz) != 0) {
311 ipseclog((LOG_WARNING,
312 "checksum mismatch in IPv4 AH input: %s %s\n",
313 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
314 free(cksum, M_TEMP);
315 ipsecstat.in_ahauthfail++;
316 goto fail;
317 }
318 }
319
320 free(cksum, M_TEMP);
321
322 m->m_flags |= M_AUTHIPHDR;
323 m->m_flags |= M_AUTHIPDGM;
324
325 #if 0
326 /*
327 * looks okey, but we need more sanity check.
328 * XXX should elaborate.
329 */
330 if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
331 struct ip *nip;
332 size_t sizoff;
333
334 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
335
336 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
337 m = m_pullup(m, off + sizeof(struct ah)
338 + sizoff + siz1 + hlen);
339 if (!m) {
340 ipseclog((LOG_DEBUG,
341 "IPv4 AH input: can't pullup\n"));
342 ipsecstat.in_inval++;
343 goto fail;
344 }
345 }
346
347 nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
348 if (nip->ip_src.s_addr != ip->ip_src.s_addr
349 || nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
350 m->m_flags &= ~M_AUTHIPHDR;
351 m->m_flags &= ~M_AUTHIPDGM;
352 }
353 }
354 #ifdef INET6
355 else if (ah->ah_nxt == IPPROTO_IPV6) {
356 m->m_flags &= ~M_AUTHIPHDR;
357 m->m_flags &= ~M_AUTHIPDGM;
358 }
359 #endif /* INET6 */
360 #endif /* 0 */
361
362 if (m->m_flags & M_AUTHIPHDR
363 && m->m_flags & M_AUTHIPDGM) {
364 #if 0
365 ipseclog((LOG_DEBUG,
366 "IPv4 AH input: authentication succeess\n"));
367 #endif
368 ipsecstat.in_ahauthsucc++;
369 } else {
370 ipseclog((LOG_WARNING,
371 "authentication failed in IPv4 AH input: %s %s\n",
372 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
373 ipsecstat.in_ahauthfail++;
374 goto fail;
375 }
376
377 /*
378 * update sequence number.
379 */
380 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
381 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
382 ipsecstat.in_ahreplay++;
383 goto fail;
384 }
385 }
386
387 /* was it transmitted over the IPsec tunnel SA? */
388 if (sav->flags & SADB_X_EXT_OLD) {
389 /* RFC 1826 */
390 stripsiz = sizeof(struct ah) + siz1;
391 } else {
392 /* RFC 2402 */
393 stripsiz = sizeof(struct newah) + siz1;
394 }
395 if (ipsec4_tunnel_validate(m, off + stripsiz, nxt, sav)) {
396 /*
397 * strip off all the headers that precedes AH.
398 * IP xx AH IP' payload -> IP' payload
399 *
400 * XXX more sanity checks
401 * XXX relationship with gif?
402 */
403 u_int8_t tos;
404
405 tos = ip->ip_tos;
406 m_adj(m, off + stripsiz);
407 if (m->m_len < sizeof(*ip)) {
408 m = m_pullup(m, sizeof(*ip));
409 if (!m) {
410 ipsecstat.in_inval++;
411 goto fail;
412 }
413 }
414 ip = mtod(m, struct ip *);
415 /* ECN consideration. */
416 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
417 if (!key_checktunnelsanity(sav, AF_INET,
418 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
419 ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
420 "in IPv4 AH input: %s %s\n",
421 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
422 ipsecstat.in_inval++;
423 goto fail;
424 }
425
426 #if 1
427 /*
428 * Should the inner packet be considered authentic?
429 * My current answer is: NO.
430 *
431 * host1 -- gw1 === gw2 -- host2
432 * In this case, gw2 can trust the authenticity of the
433 * outer packet, but NOT inner. Packet may be altered
434 * between host1 and gw1.
435 *
436 * host1 -- gw1 === host2
437 * This case falls into the same scenario as above.
438 *
439 * host1 === host2
440 * This case is the only case when we may be able to leave
441 * M_AUTHIPHDR and M_AUTHIPDGM set.
442 * However, if host1 is wrongly configured, and allows
443 * attacker to inject some packet with src=host1 and
444 * dst=host2, you are in risk.
445 */
446 m->m_flags &= ~M_AUTHIPHDR;
447 m->m_flags &= ~M_AUTHIPDGM;
448 #endif
449
450 key_sa_recordxfer(sav, m);
451 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
452 ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
453 ipsecstat.in_nomem++;
454 goto fail;
455 }
456
457 if (! netisr_queue(NETISR_IP, m)) {
458 ipsecstat.in_inval++;
459 m = NULL;
460 goto fail;
461 }
462 m = NULL;
463 nxt = IPPROTO_DONE;
464 } else {
465 /*
466 * strip off AH.
467 */
468
469 ip = mtod(m, struct ip *);
470 #ifndef PULLDOWN_TEST
471 /*
472 * We do deep-copy since KAME requires that
473 * the packet is placed in a single external mbuf.
474 */
475 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
476 m->m_data += stripsiz;
477 m->m_len -= stripsiz;
478 m->m_pkthdr.len -= stripsiz;
479 #else
480 /*
481 * even in m_pulldown case, we need to strip off AH so that
482 * we can compute checksum for multiple AH correctly.
483 */
484 if (m->m_len >= stripsiz + off) {
485 ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
486 m->m_data += stripsiz;
487 m->m_len -= stripsiz;
488 m->m_pkthdr.len -= stripsiz;
489 } else {
490 /*
491 * this comes with no copy if the boundary is on
492 * cluster
493 */
494 struct mbuf *n;
495
496 n = m_split(m, off, M_DONTWAIT);
497 if (n == NULL) {
498 /* m is retained by m_split */
499 goto fail;
500 }
501 m_adj(n, stripsiz);
502 m_cat(m, n);
503 /* m_cat does not update m_pkthdr.len */
504 m->m_pkthdr.len += n->m_pkthdr.len;
505 }
506 #endif
507
508 if (m->m_len < sizeof(*ip)) {
509 m = m_pullup(m, sizeof(*ip));
510 if (m == NULL) {
511 ipsecstat.in_inval++;
512 goto fail;
513 }
514 }
515 ip = mtod(m, struct ip *);
516 #ifdef IPLEN_FLIPPED
517 ip->ip_len = ip->ip_len - stripsiz;
518 #else
519 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
520 #endif
521 ip->ip_p = nxt;
522 /* forget about IP hdr checksum, the check has already been passed */
523
524 key_sa_recordxfer(sav, m);
525 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
526 ipsecstat.in_nomem++;
527 goto fail;
528 }
529
530 if (nxt != IPPROTO_DONE) {
531 if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
532 ipsec4_in_reject(m, NULL)) {
533 ipsecstat.in_polvio++;
534 goto fail;
535 }
536 (*inetsw[ip_protox[nxt]].pr_input)(m, off);
537 } else
538 m_freem(m);
539 m = NULL;
540 }
541
542 if (sav) {
543 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
544 printf("DP ah4_input call free SA:%p\n", sav));
545 key_freesav(sav);
546 }
547 ipsecstat.in_success++;
548 return;
549
550 fail:
551 if (sav) {
552 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
553 printf("DP ah4_input call free SA:%p\n", sav));
554 key_freesav(sav);
555 }
556 if (m)
557 m_freem(m);
558 return;
559 }
560 #endif /* INET */
561
562 #ifdef INET6
563 int
564 ah6_input(mp, offp, proto)
565 struct mbuf **mp;
566 int *offp, proto;
567 {
568 struct mbuf *m = *mp;
569 int off = *offp;
570 struct ip6_hdr *ip6;
571 struct ah *ah;
572 u_int32_t spi;
573 const struct ah_algorithm *algo;
574 size_t siz;
575 size_t siz1;
576 u_char *cksum;
577 struct secasvar *sav = NULL;
578 u_int16_t nxt;
579 size_t stripsiz = 0;
580
581 #ifndef PULLDOWN_TEST
582 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
583 ah = (struct ah *)(mtod(m, caddr_t) + off);
584 #else
585 IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
586 if (ah == NULL) {
587 ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
588 ipsec6stat.in_inval++;
589 return IPPROTO_DONE;
590 }
591 #endif
592 ip6 = mtod(m, struct ip6_hdr *);
593 nxt = ah->ah_nxt;
594
595 /* find the sassoc. */
596 spi = ah->ah_spi;
597
598 if (ntohs(ip6->ip6_plen) == 0) {
599 ipseclog((LOG_ERR, "IPv6 AH input: "
600 "AH with IPv6 jumbogram is not supported.\n"));
601 ipsec6stat.in_inval++;
602 goto fail;
603 }
604
605 if ((sav = key_allocsa(AF_INET6,
606 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
607 IPPROTO_AH, spi)) == 0) {
608 ipseclog((LOG_WARNING,
609 "IPv6 AH input: no key association found for spi %u\n",
610 (u_int32_t)ntohl(spi)));
611 ipsec6stat.in_nosa++;
612 goto fail;
613 }
614 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
615 printf("DP ah6_input called to allocate SA:%p\n", sav));
616 if (sav->state != SADB_SASTATE_MATURE
617 && sav->state != SADB_SASTATE_DYING) {
618 ipseclog((LOG_DEBUG,
619 "IPv6 AH input: non-mature/dying SA found for spi %u; ",
620 (u_int32_t)ntohl(spi)));
621 ipsec6stat.in_badspi++;
622 goto fail;
623 }
624
625 algo = ah_algorithm_lookup(sav->alg_auth);
626 if (!algo) {
627 ipseclog((LOG_DEBUG, "IPv6 AH input: "
628 "unsupported authentication algorithm for spi %u\n",
629 (u_int32_t)ntohl(spi)));
630 ipsec6stat.in_badspi++;
631 goto fail;
632 }
633
634 siz = (*algo->sumsiz)(sav);
635 siz1 = ((siz + 3) & ~(4 - 1));
636
637 /*
638 * sanity checks for header, 1.
639 */
640 {
641 int sizoff;
642
643 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
644
645 /*
646 * Here, we do not do "siz1 == siz". See ah4_input() for complete
647 * description.
648 */
649 if (siz1 < siz) {
650 ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
651 "(%lu, should be at least %lu): %s\n",
652 (u_long)siz1, (u_long)siz,
653 ipsec6_logpacketstr(ip6, spi)));
654 ipsec6stat.in_inval++;
655 goto fail;
656 }
657 if ((ah->ah_len << 2) - sizoff != siz1) {
658 ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
659 "(%d should be %lu): %s\n",
660 (ah->ah_len << 2) - sizoff, (u_long)siz1,
661 ipsec6_logpacketstr(ip6, spi)));
662 ipsec6stat.in_inval++;
663 goto fail;
664 }
665 #ifndef PULLDOWN_TEST
666 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
667 #else
668 IP6_EXTHDR_GET(ah, struct ah *, m, off,
669 sizeof(struct ah) + sizoff + siz1);
670 if (ah == NULL) {
671 ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
672 ipsec6stat.in_inval++;
673 m = NULL;
674 goto fail;
675 }
676 #endif
677 }
678
679 /*
680 * check for sequence number.
681 */
682 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
683 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
684 ; /* okey */
685 else {
686 ipsec6stat.in_ahreplay++;
687 ipseclog((LOG_WARNING,
688 "replay packet in IPv6 AH input: %s %s\n",
689 ipsec6_logpacketstr(ip6, spi),
690 ipsec_logsastr(sav)));
691 goto fail;
692 }
693 }
694
695 /*
696 * alright, it seems sane. now we are going to check the
697 * cryptographic checksum.
698 */
699 cksum = malloc(siz1, M_TEMP, M_NOWAIT);
700 if (!cksum) {
701 ipseclog((LOG_DEBUG, "IPv6 AH input: "
702 "couldn't alloc temporary region for cksum\n"));
703 ipsec6stat.in_inval++;
704 goto fail;
705 }
706
707 if (ah6_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
708 free(cksum, M_TEMP);
709 ipsec6stat.in_inval++;
710 goto fail;
711 }
712 ipsec6stat.in_ahhist[sav->alg_auth]++;
713
714 {
715 caddr_t sumpos = NULL;
716
717 if (sav->flags & SADB_X_EXT_OLD) {
718 /* RFC 1826 */
719 sumpos = (caddr_t)(ah + 1);
720 } else {
721 /* RFC 2402 */
722 sumpos = (caddr_t)(((struct newah *)ah) + 1);
723 }
724
725 if (bcmp(sumpos, cksum, siz) != 0) {
726 ipseclog((LOG_WARNING,
727 "checksum mismatch in IPv6 AH input: %s %s\n",
728 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
729 free(cksum, M_TEMP);
730 ipsec6stat.in_ahauthfail++;
731 goto fail;
732 }
733 }
734
735 free(cksum, M_TEMP);
736
737 m->m_flags |= M_AUTHIPHDR;
738 m->m_flags |= M_AUTHIPDGM;
739
740 #if 0
741 /*
742 * looks okey, but we need more sanity check.
743 * XXX should elaborate.
744 */
745 if (ah->ah_nxt == IPPROTO_IPV6) {
746 struct ip6_hdr *nip6;
747 size_t sizoff;
748
749 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
750
751 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
752 + sizeof(struct ip6_hdr), IPPROTO_DONE);
753
754 nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
755 if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
756 || !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
757 m->m_flags &= ~M_AUTHIPHDR;
758 m->m_flags &= ~M_AUTHIPDGM;
759 }
760 } else if (ah->ah_nxt == IPPROTO_IPIP) {
761 m->m_flags &= ~M_AUTHIPHDR;
762 m->m_flags &= ~M_AUTHIPDGM;
763 } else if (ah->ah_nxt == IPPROTO_IP) {
764 m->m_flags &= ~M_AUTHIPHDR;
765 m->m_flags &= ~M_AUTHIPDGM;
766 }
767 #endif
768
769 if (m->m_flags & M_AUTHIPHDR
770 && m->m_flags & M_AUTHIPDGM) {
771 #if 0
772 ipseclog((LOG_DEBUG,
773 "IPv6 AH input: authentication succeess\n"));
774 #endif
775 ipsec6stat.in_ahauthsucc++;
776 } else {
777 ipseclog((LOG_WARNING,
778 "authentication failed in IPv6 AH input: %s %s\n",
779 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
780 ipsec6stat.in_ahauthfail++;
781 goto fail;
782 }
783
784 /*
785 * update sequence number.
786 */
787 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
788 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
789 ipsec6stat.in_ahreplay++;
790 goto fail;
791 }
792 }
793
794 /* was it transmitted over the IPsec tunnel SA? */
795 if (sav->flags & SADB_X_EXT_OLD) {
796 /* RFC 1826 */
797 stripsiz = sizeof(struct ah) + siz1;
798 } else {
799 /* RFC 2402 */
800 stripsiz = sizeof(struct newah) + siz1;
801 }
802 if (ipsec6_tunnel_validate(m, off + stripsiz, nxt, sav)) {
803 /*
804 * strip off all the headers that precedes AH.
805 * IP6 xx AH IP6' payload -> IP6' payload
806 *
807 * XXX more sanity checks
808 * XXX relationship with gif?
809 */
810 u_int32_t flowinfo; /* net endian */
811
812 flowinfo = ip6->ip6_flow;
813 m_adj(m, off + stripsiz);
814 if (m->m_len < sizeof(*ip6)) {
815 /*
816 * m_pullup is prohibited in KAME IPv6 input processing
817 * but there's no other way!
818 */
819 m = m_pullup(m, sizeof(*ip6));
820 if (!m) {
821 ipsec6stat.in_inval++;
822 goto fail;
823 }
824 }
825 ip6 = mtod(m, struct ip6_hdr *);
826 /* ECN consideration. */
827 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
828 if (!key_checktunnelsanity(sav, AF_INET6,
829 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
830 ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
831 "in IPv6 AH input: %s %s\n",
832 ipsec6_logpacketstr(ip6, spi),
833 ipsec_logsastr(sav)));
834 ipsec6stat.in_inval++;
835 goto fail;
836 }
837
838 #if 1
839 /*
840 * should the inner packet be considered authentic?
841 * see comment in ah4_input().
842 */
843 m->m_flags &= ~M_AUTHIPHDR;
844 m->m_flags &= ~M_AUTHIPDGM;
845 #endif
846
847 key_sa_recordxfer(sav, m);
848 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
849 ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
850 ipsec6stat.in_nomem++;
851 goto fail;
852 }
853
854 if (! netisr_queue(NETISR_IPV6, m)) {
855 ipsec6stat.in_inval++;
856 m = NULL;
857 goto fail;
858 }
859 m = NULL;
860 nxt = IPPROTO_DONE;
861 } else {
862 /*
863 * strip off AH.
864 */
865 char *prvnxtp;
866
867 /*
868 * Copy the value of the next header field of AH to the
869 * next header field of the previous header.
870 * This is necessary because AH will be stripped off below.
871 */
872 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
873 *prvnxtp = nxt;
874
875 ip6 = mtod(m, struct ip6_hdr *);
876 #ifndef PULLDOWN_TEST
877 /*
878 * We do deep-copy since KAME requires that
879 * the packet is placed in a single mbuf.
880 */
881 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
882 m->m_data += stripsiz;
883 m->m_len -= stripsiz;
884 m->m_pkthdr.len -= stripsiz;
885 #else
886 /*
887 * even in m_pulldown case, we need to strip off AH so that
888 * we can compute checksum for multiple AH correctly.
889 */
890 if (m->m_len >= stripsiz + off) {
891 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
892 m->m_data += stripsiz;
893 m->m_len -= stripsiz;
894 m->m_pkthdr.len -= stripsiz;
895 } else {
896 /*
897 * this comes with no copy if the boundary is on
898 * cluster
899 */
900 struct mbuf *n;
901
902 n = m_split(m, off, M_DONTWAIT);
903 if (n == NULL) {
904 /* m is retained by m_split */
905 goto fail;
906 }
907 m_adj(n, stripsiz);
908 m_cat(m, n);
909 /* m_cat does not update m_pkthdr.len */
910 m->m_pkthdr.len += n->m_pkthdr.len;
911 }
912 #endif
913 ip6 = mtod(m, struct ip6_hdr *);
914 /* XXX jumbogram */
915 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
916
917 key_sa_recordxfer(sav, m);
918 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
919 ipsec6stat.in_nomem++;
920 goto fail;
921 }
922 }
923
924 *offp = off;
925 *mp = m;
926
927 if (sav) {
928 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
929 printf("DP ah6_input call free SA:%p\n", sav));
930 key_freesav(sav);
931 }
932 ipsec6stat.in_success++;
933 return nxt;
934
935 fail:
936 if (sav) {
937 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
938 printf("DP ah6_input call free SA:%p\n", sav));
939 key_freesav(sav);
940 }
941 if (m)
942 m_freem(m);
943 return IPPROTO_DONE;
944 }
945
946 void
947 ah6_ctlinput(cmd, sa, d)
948 int cmd;
949 struct sockaddr *sa;
950 void *d;
951 {
952 const struct newah *ahp;
953 struct newah ah;
954 struct secasvar *sav;
955 struct ip6_hdr *ip6;
956 struct mbuf *m;
957 struct ip6ctlparam *ip6cp = NULL;
958 int off;
959 struct sockaddr_in6 *sa6_src, *sa6_dst;
960
961 if (sa->sa_family != AF_INET6 ||
962 sa->sa_len != sizeof(struct sockaddr_in6))
963 return;
964 if ((unsigned)cmd >= PRC_NCMDS)
965 return;
966
967 /* if the parameter is from icmp6, decode it. */
968 if (d != NULL) {
969 ip6cp = (struct ip6ctlparam *)d;
970 m = ip6cp->ip6c_m;
971 ip6 = ip6cp->ip6c_ip6;
972 off = ip6cp->ip6c_off;
973 } else {
974 m = NULL;
975 ip6 = NULL;
976 off = 0; /* calm gcc */
977 }
978
979 if (ip6) {
980 /*
981 * XXX: We assume that when ip6 is non NULL,
982 * M and OFF are valid.
983 */
984
985 /* check if we can safely examine src and dst ports */
986 if (m->m_pkthdr.len < off + sizeof(ah))
987 return;
988
989 if (m->m_len < off + sizeof(ah)) {
990 /*
991 * this should be rare case,
992 * so we compromise on this copy...
993 */
994 m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
995 ahp = &ah;
996 } else
997 ahp = (struct newah *)(mtod(m, caddr_t) + off);
998
999 if (cmd == PRC_MSGSIZE) {
1000 int valid = 0;
1001
1002 /*
1003 * Check to see if we have a valid SA corresponding to
1004 * the address in the ICMP message payload.
1005 */
1006 sa6_src = ip6cp->ip6c_src;
1007 sa6_dst = (struct sockaddr_in6 *)sa;
1008 sav = key_allocsa(AF_INET6,
1009 (caddr_t)&sa6_src->sin6_addr,
1010 (caddr_t)&sa6_dst->sin6_addr,
1011 IPPROTO_AH, ahp->ah_spi);
1012 if (sav) {
1013 if (sav->state == SADB_SASTATE_MATURE ||
1014 sav->state == SADB_SASTATE_DYING)
1015 valid++;
1016 key_freesav(sav);
1017 }
1018
1019 /* XXX Further validation? */
1020
1021 /*
1022 * Depending on the value of "valid" and routing table
1023 * size (mtudisc_{hi,lo}wat), we will:
1024 * - recalcurate the new MTU and create the
1025 * corresponding routing entry, or
1026 * - ignore the MTU change notification.
1027 */
1028 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1029 }
1030
1031 /* we normally notify single pcb here */
1032 } else {
1033 /* we normally notify any pcb here */
1034 }
1035 }
1036 #endif /* INET6 */
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