1 /* $FreeBSD$ */
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_int8_t cksum[AH_MAXSUMSIZE];
112 struct secasvar *sav = NULL;
113 u_int16_t nxt;
114 size_t hlen;
115 size_t stripsiz = 0;
116
117 #ifndef PULLDOWN_TEST
118 if (m->m_len < off + sizeof(struct newah)) {
119 m = m_pullup(m, off + sizeof(struct newah));
120 if (!m) {
121 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
122 "dropping the packet for simplicity\n"));
123 ipsecstat.in_inval++;
124 goto fail;
125 }
126 }
127
128 ip = mtod(m, struct ip *);
129 ah = (struct ah *)(((caddr_t)ip) + off);
130 #else
131 ip = mtod(m, struct ip *);
132 IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
133 if (ah == NULL) {
134 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
135 "dropping the packet for simplicity\n"));
136 ipsecstat.in_inval++;
137 goto fail;
138 }
139 #endif
140 nxt = ah->ah_nxt;
141 #ifdef _IP_VHL
142 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
143 #else
144 hlen = ip->ip_hl << 2;
145 #endif
146
147 /* find the sassoc. */
148 spi = ah->ah_spi;
149
150 if ((sav = key_allocsa(AF_INET,
151 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
152 IPPROTO_AH, spi)) == 0) {
153 ipseclog((LOG_WARNING,
154 "IPv4 AH input: no key association found for spi %u\n",
155 (u_int32_t)ntohl(spi)));
156 ipsecstat.in_nosa++;
157 goto fail;
158 }
159 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
160 printf("DP ah4_input called to allocate SA:%p\n", sav));
161 if (sav->state != SADB_SASTATE_MATURE
162 && sav->state != SADB_SASTATE_DYING) {
163 ipseclog((LOG_DEBUG,
164 "IPv4 AH input: non-mature/dying SA found for spi %u\n",
165 (u_int32_t)ntohl(spi)));
166 ipsecstat.in_badspi++;
167 goto fail;
168 }
169
170 algo = ah_algorithm_lookup(sav->alg_auth);
171 if (!algo) {
172 ipseclog((LOG_DEBUG, "IPv4 AH input: "
173 "unsupported authentication algorithm for spi %u\n",
174 (u_int32_t)ntohl(spi)));
175 ipsecstat.in_badspi++;
176 goto fail;
177 }
178
179 siz = (*algo->sumsiz)(sav);
180 siz1 = ((siz + 3) & ~(4 - 1));
181
182 /*
183 * sanity checks for header, 1.
184 */
185 {
186 int sizoff;
187
188 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
189
190 /*
191 * Here, we do not do "siz1 == siz". This is because the way
192 * RFC240[34] section 2 is written. They do not require truncation
193 * to 96 bits.
194 * For example, Microsoft IPsec stack attaches 160 bits of
195 * authentication data for both hmac-md5 and hmac-sha1. For hmac-sha1,
196 * 32 bits of padding is attached.
197 *
198 * There are two downsides to this specification.
199 * They have no real harm, however, they leave us fuzzy feeling.
200 * - if we attach more than 96 bits of authentication data onto AH,
201 * we will never notice about possible modification by rogue
202 * intermediate nodes.
203 * Since extra bits in AH checksum is never used, this constitutes
204 * no real issue, however, it is wacky.
205 * - even if the peer attaches big authentication data, we will never
206 * notice the difference, since longer authentication data will just
207 * work.
208 *
209 * We may need some clarification in the spec.
210 */
211 if (siz1 < siz) {
212 ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
213 "(%lu, should be at least %lu): %s\n",
214 (u_long)siz1, (u_long)siz,
215 ipsec4_logpacketstr(ip, spi)));
216 ipsecstat.in_inval++;
217 goto fail;
218 }
219 if ((ah->ah_len << 2) - sizoff != siz1) {
220 ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
221 "(%d should be %lu): %s\n",
222 (ah->ah_len << 2) - sizoff, (u_long)siz1,
223 ipsec4_logpacketstr(ip, spi)));
224 ipsecstat.in_inval++;
225 goto fail;
226 }
227 if (siz1 > sizeof(cksum)) {
228 ipseclog((LOG_NOTICE, "sum length too large: %s\n",
229 ipsec4_logpacketstr(ip, spi)));
230 ipsecstat.in_inval++;
231 goto fail;
232 }
233
234 #ifndef PULLDOWN_TEST
235 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
236 m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
237 if (!m) {
238 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
239 ipsecstat.in_inval++;
240 goto fail;
241 }
242
243 ip = mtod(m, struct ip *);
244 ah = (struct ah *)(((caddr_t)ip) + off);
245 }
246 #else
247 IP6_EXTHDR_GET(ah, struct ah *, m, off,
248 sizeof(struct ah) + sizoff + siz1);
249 if (ah == NULL) {
250 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
251 ipsecstat.in_inval++;
252 goto fail;
253 }
254 #endif
255 }
256
257 /*
258 * check for sequence number.
259 */
260 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
261 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
262 ; /* okey */
263 else {
264 ipsecstat.in_ahreplay++;
265 ipseclog((LOG_WARNING,
266 "replay packet in IPv4 AH input: %s %s\n",
267 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
268 goto fail;
269 }
270 }
271
272 /*
273 * alright, it seems sane. now we are going to check the
274 * cryptographic checksum.
275 */
276
277 /*
278 * some of IP header fields are flipped to the host endian.
279 * convert them back to network endian. VERY stupid.
280 */
281 ip->ip_len = htons(ip->ip_len + hlen);
282 ip->ip_off = htons(ip->ip_off);
283 if (ah4_calccksum(m, cksum, siz1, algo, sav)) {
284 ipsecstat.in_inval++;
285 goto fail;
286 }
287 ipsecstat.in_ahhist[sav->alg_auth]++;
288 /*
289 * flip them back.
290 */
291 ip->ip_len = ntohs(ip->ip_len) - hlen;
292 ip->ip_off = ntohs(ip->ip_off);
293
294 {
295 caddr_t sumpos = NULL;
296
297 if (sav->flags & SADB_X_EXT_OLD) {
298 /* RFC 1826 */
299 sumpos = (caddr_t)(ah + 1);
300 } else {
301 /* RFC 2402 */
302 sumpos = (caddr_t)(((struct newah *)ah) + 1);
303 }
304
305 if (bcmp(sumpos, cksum, siz) != 0) {
306 ipseclog((LOG_WARNING,
307 "checksum mismatch in IPv4 AH input: %s %s\n",
308 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
309 ipsecstat.in_ahauthfail++;
310 goto fail;
311 }
312 }
313
314 m->m_flags |= M_AUTHIPHDR;
315 m->m_flags |= M_AUTHIPDGM;
316
317 #if 0
318 /*
319 * looks okey, but we need more sanity check.
320 * XXX should elaborate.
321 */
322 if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
323 struct ip *nip;
324 size_t sizoff;
325
326 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
327
328 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
329 m = m_pullup(m, off + sizeof(struct ah)
330 + sizoff + siz1 + hlen);
331 if (!m) {
332 ipseclog((LOG_DEBUG,
333 "IPv4 AH input: can't pullup\n"));
334 ipsecstat.in_inval++;
335 goto fail;
336 }
337 }
338
339 nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
340 if (nip->ip_src.s_addr != ip->ip_src.s_addr
341 || nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
342 m->m_flags &= ~M_AUTHIPHDR;
343 m->m_flags &= ~M_AUTHIPDGM;
344 }
345 }
346 #ifdef INET6
347 else if (ah->ah_nxt == IPPROTO_IPV6) {
348 m->m_flags &= ~M_AUTHIPHDR;
349 m->m_flags &= ~M_AUTHIPDGM;
350 }
351 #endif /* INET6 */
352 #endif /* 0 */
353
354 if (m->m_flags & M_AUTHIPHDR
355 && m->m_flags & M_AUTHIPDGM) {
356 #if 0
357 ipseclog((LOG_DEBUG,
358 "IPv4 AH input: authentication succeess\n"));
359 #endif
360 ipsecstat.in_ahauthsucc++;
361 } else {
362 ipseclog((LOG_WARNING,
363 "authentication failed in IPv4 AH input: %s %s\n",
364 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
365 ipsecstat.in_ahauthfail++;
366 goto fail;
367 }
368
369 /*
370 * update sequence number.
371 */
372 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
373 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
374 ipsecstat.in_ahreplay++;
375 goto fail;
376 }
377 }
378
379 /* was it transmitted over the IPsec tunnel SA? */
380 if (sav->flags & SADB_X_EXT_OLD) {
381 /* RFC 1826 */
382 stripsiz = sizeof(struct ah) + siz1;
383 } else {
384 /* RFC 2402 */
385 stripsiz = sizeof(struct newah) + siz1;
386 }
387 if (ipsec4_tunnel_validate(m, off + stripsiz, nxt, sav)) {
388 /*
389 * strip off all the headers that precedes AH.
390 * IP xx AH IP' payload -> IP' payload
391 *
392 * XXX more sanity checks
393 * XXX relationship with gif?
394 */
395 u_int8_t tos;
396
397 tos = ip->ip_tos;
398 m_adj(m, off + stripsiz);
399 if (m->m_len < sizeof(*ip)) {
400 m = m_pullup(m, sizeof(*ip));
401 if (!m) {
402 ipsecstat.in_inval++;
403 goto fail;
404 }
405 }
406 ip = mtod(m, struct ip *);
407 /* ECN consideration. */
408 if (!ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos)) {
409 ipsecstat.in_inval++;
410 goto fail;
411 }
412 if (!key_checktunnelsanity(sav, AF_INET,
413 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
414 ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
415 "in IPv4 AH input: %s %s\n",
416 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
417 ipsecstat.in_inval++;
418 goto fail;
419 }
420
421 #if 1
422 /*
423 * Should the inner packet be considered authentic?
424 * My current answer is: NO.
425 *
426 * host1 -- gw1 === gw2 -- host2
427 * In this case, gw2 can trust the authenticity of the
428 * outer packet, but NOT inner. Packet may be altered
429 * between host1 and gw1.
430 *
431 * host1 -- gw1 === host2
432 * This case falls into the same scenario as above.
433 *
434 * host1 === host2
435 * This case is the only case when we may be able to leave
436 * M_AUTHIPHDR and M_AUTHIPDGM set.
437 * However, if host1 is wrongly configured, and allows
438 * attacker to inject some packet with src=host1 and
439 * dst=host2, you are in risk.
440 */
441 m->m_flags &= ~M_AUTHIPHDR;
442 m->m_flags &= ~M_AUTHIPDGM;
443 #endif
444
445 key_sa_recordxfer(sav, m);
446 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
447 ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
448 ipsecstat.in_nomem++;
449 goto fail;
450 }
451
452 if (netisr_queue(NETISR_IP, m)) { /* (0) on success. */
453 ipsecstat.in_inval++;
454 m = NULL;
455 goto fail;
456 }
457 m = NULL;
458 nxt = IPPROTO_DONE;
459 } else {
460 /*
461 * strip off AH.
462 */
463
464 ip = mtod(m, struct ip *);
465 #ifndef PULLDOWN_TEST
466 /*
467 * We do deep-copy since KAME requires that
468 * the packet is placed in a single external mbuf.
469 */
470 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
471 m->m_data += stripsiz;
472 m->m_len -= stripsiz;
473 m->m_pkthdr.len -= stripsiz;
474 #else
475 /*
476 * even in m_pulldown case, we need to strip off AH so that
477 * we can compute checksum for multiple AH correctly.
478 */
479 if (m->m_len >= stripsiz + off) {
480 ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
481 m->m_data += stripsiz;
482 m->m_len -= stripsiz;
483 m->m_pkthdr.len -= stripsiz;
484 } else {
485 /*
486 * this comes with no copy if the boundary is on
487 * cluster
488 */
489 struct mbuf *n;
490
491 n = m_split(m, off, M_DONTWAIT);
492 if (n == NULL) {
493 /* m is retained by m_split */
494 goto fail;
495 }
496 m_adj(n, stripsiz);
497 /* m_cat does not update m_pkthdr.len */
498 m->m_pkthdr.len += n->m_pkthdr.len;
499 m_cat(m, n);
500 }
501 #endif
502
503 if (m->m_len < sizeof(*ip)) {
504 m = m_pullup(m, sizeof(*ip));
505 if (m == NULL) {
506 ipsecstat.in_inval++;
507 goto fail;
508 }
509 }
510 ip = mtod(m, struct ip *);
511 #ifdef IPLEN_FLIPPED
512 ip->ip_len = ip->ip_len - stripsiz;
513 #else
514 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
515 #endif
516 ip->ip_p = nxt;
517 /* forget about IP hdr checksum, the check has already been passed */
518
519 key_sa_recordxfer(sav, m);
520 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
521 ipsecstat.in_nomem++;
522 goto fail;
523 }
524
525 if (nxt != IPPROTO_DONE) {
526 if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
527 ipsec4_in_reject(m, NULL)) {
528 ipsecstat.in_polvio++;
529 goto fail;
530 }
531 (*inetsw[ip_protox[nxt]].pr_input)(m, off);
532 } else
533 m_freem(m);
534 m = NULL;
535 }
536
537 if (sav) {
538 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
539 printf("DP ah4_input call free SA:%p\n", sav));
540 key_freesav(sav);
541 }
542 ipsecstat.in_success++;
543 return;
544
545 fail:
546 if (sav) {
547 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
548 printf("DP ah4_input call free SA:%p\n", sav));
549 key_freesav(sav);
550 }
551 if (m)
552 m_freem(m);
553 return;
554 }
555 #endif /* INET */
556
557 #ifdef INET6
558 int
559 ah6_input(mp, offp, proto)
560 struct mbuf **mp;
561 int *offp, proto;
562 {
563 struct mbuf *m = *mp;
564 int off = *offp;
565 struct ip6_hdr *ip6;
566 struct ah *ah;
567 u_int32_t spi;
568 const struct ah_algorithm *algo;
569 size_t siz;
570 size_t siz1;
571 u_int8_t cksum[AH_MAXSUMSIZE];
572 struct secasvar *sav = NULL;
573 u_int16_t nxt;
574 size_t stripsiz = 0;
575
576 #ifndef PULLDOWN_TEST
577 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
578 ah = (struct ah *)(mtod(m, caddr_t) + off);
579 #else
580 IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
581 if (ah == NULL) {
582 ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
583 ipsec6stat.in_inval++;
584 return IPPROTO_DONE;
585 }
586 #endif
587 ip6 = mtod(m, struct ip6_hdr *);
588 nxt = ah->ah_nxt;
589
590 /* find the sassoc. */
591 spi = ah->ah_spi;
592
593 if (ntohs(ip6->ip6_plen) == 0) {
594 ipseclog((LOG_ERR, "IPv6 AH input: "
595 "AH with IPv6 jumbogram is not supported.\n"));
596 ipsec6stat.in_inval++;
597 goto fail;
598 }
599
600 if ((sav = key_allocsa(AF_INET6,
601 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
602 IPPROTO_AH, spi)) == 0) {
603 ipseclog((LOG_WARNING,
604 "IPv6 AH input: no key association found for spi %u\n",
605 (u_int32_t)ntohl(spi)));
606 ipsec6stat.in_nosa++;
607 goto fail;
608 }
609 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
610 printf("DP ah6_input called to allocate SA:%p\n", sav));
611 if (sav->state != SADB_SASTATE_MATURE
612 && sav->state != SADB_SASTATE_DYING) {
613 ipseclog((LOG_DEBUG,
614 "IPv6 AH input: non-mature/dying SA found for spi %u; ",
615 (u_int32_t)ntohl(spi)));
616 ipsec6stat.in_badspi++;
617 goto fail;
618 }
619
620 algo = ah_algorithm_lookup(sav->alg_auth);
621 if (!algo) {
622 ipseclog((LOG_DEBUG, "IPv6 AH input: "
623 "unsupported authentication algorithm for spi %u\n",
624 (u_int32_t)ntohl(spi)));
625 ipsec6stat.in_badspi++;
626 goto fail;
627 }
628
629 siz = (*algo->sumsiz)(sav);
630 siz1 = ((siz + 3) & ~(4 - 1));
631
632 /*
633 * sanity checks for header, 1.
634 */
635 {
636 int sizoff;
637
638 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
639
640 /*
641 * Here, we do not do "siz1 == siz". See ah4_input() for complete
642 * description.
643 */
644 if (siz1 < siz) {
645 ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
646 "(%lu, should be at least %lu): %s\n",
647 (u_long)siz1, (u_long)siz,
648 ipsec6_logpacketstr(ip6, spi)));
649 ipsec6stat.in_inval++;
650 goto fail;
651 }
652 if ((ah->ah_len << 2) - sizoff != siz1) {
653 ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
654 "(%d should be %lu): %s\n",
655 (ah->ah_len << 2) - sizoff, (u_long)siz1,
656 ipsec6_logpacketstr(ip6, spi)));
657 ipsec6stat.in_inval++;
658 goto fail;
659 }
660 if (siz1 > sizeof(cksum)) {
661 ipseclog((LOG_NOTICE, "sum length too large: %s\n",
662 ipsec6_logpacketstr(ip6, spi)));
663 ipsec6stat.in_inval++;
664 goto fail;
665 }
666
667 #ifndef PULLDOWN_TEST
668 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
669 #else
670 IP6_EXTHDR_GET(ah, struct ah *, m, off,
671 sizeof(struct ah) + sizoff + siz1);
672 if (ah == NULL) {
673 ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
674 ipsec6stat.in_inval++;
675 m = NULL;
676 goto fail;
677 }
678 #endif
679 }
680
681 /*
682 * check for sequence number.
683 */
684 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
685 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
686 ; /* okey */
687 else {
688 ipsec6stat.in_ahreplay++;
689 ipseclog((LOG_WARNING,
690 "replay packet in IPv6 AH input: %s %s\n",
691 ipsec6_logpacketstr(ip6, spi),
692 ipsec_logsastr(sav)));
693 goto fail;
694 }
695 }
696
697 /*
698 * alright, it seems sane. now we are going to check the
699 * cryptographic checksum.
700 */
701
702 if (ah6_calccksum(m, cksum, siz1, algo, sav)) {
703 ipsec6stat.in_inval++;
704 goto fail;
705 }
706 ipsec6stat.in_ahhist[sav->alg_auth]++;
707
708 {
709 caddr_t sumpos = NULL;
710
711 if (sav->flags & SADB_X_EXT_OLD) {
712 /* RFC 1826 */
713 sumpos = (caddr_t)(ah + 1);
714 } else {
715 /* RFC 2402 */
716 sumpos = (caddr_t)(((struct newah *)ah) + 1);
717 }
718
719 if (bcmp(sumpos, cksum, siz) != 0) {
720 ipseclog((LOG_WARNING,
721 "checksum mismatch in IPv6 AH input: %s %s\n",
722 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
723 ipsec6stat.in_ahauthfail++;
724 goto fail;
725 }
726 }
727
728 m->m_flags |= M_AUTHIPHDR;
729 m->m_flags |= M_AUTHIPDGM;
730
731 #if 0
732 /*
733 * looks okey, but we need more sanity check.
734 * XXX should elaborate.
735 */
736 if (ah->ah_nxt == IPPROTO_IPV6) {
737 struct ip6_hdr *nip6;
738 size_t sizoff;
739
740 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
741
742 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
743 + sizeof(struct ip6_hdr), IPPROTO_DONE);
744
745 nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
746 if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
747 || !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
748 m->m_flags &= ~M_AUTHIPHDR;
749 m->m_flags &= ~M_AUTHIPDGM;
750 }
751 } else if (ah->ah_nxt == IPPROTO_IPIP) {
752 m->m_flags &= ~M_AUTHIPHDR;
753 m->m_flags &= ~M_AUTHIPDGM;
754 } else if (ah->ah_nxt == IPPROTO_IP) {
755 m->m_flags &= ~M_AUTHIPHDR;
756 m->m_flags &= ~M_AUTHIPDGM;
757 }
758 #endif
759
760 if (m->m_flags & M_AUTHIPHDR
761 && m->m_flags & M_AUTHIPDGM) {
762 #if 0
763 ipseclog((LOG_DEBUG,
764 "IPv6 AH input: authentication succeess\n"));
765 #endif
766 ipsec6stat.in_ahauthsucc++;
767 } else {
768 ipseclog((LOG_WARNING,
769 "authentication failed in IPv6 AH input: %s %s\n",
770 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
771 ipsec6stat.in_ahauthfail++;
772 goto fail;
773 }
774
775 /*
776 * update sequence number.
777 */
778 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
779 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
780 ipsec6stat.in_ahreplay++;
781 goto fail;
782 }
783 }
784
785 /* was it transmitted over the IPsec tunnel SA? */
786 if (sav->flags & SADB_X_EXT_OLD) {
787 /* RFC 1826 */
788 stripsiz = sizeof(struct ah) + siz1;
789 } else {
790 /* RFC 2402 */
791 stripsiz = sizeof(struct newah) + siz1;
792 }
793 if (ipsec6_tunnel_validate(m, off + stripsiz, nxt, sav)) {
794 /*
795 * strip off all the headers that precedes AH.
796 * IP6 xx AH IP6' payload -> IP6' payload
797 *
798 * XXX more sanity checks
799 * XXX relationship with gif?
800 */
801 u_int32_t flowinfo; /* net endian */
802
803 flowinfo = ip6->ip6_flow;
804 m_adj(m, off + stripsiz);
805 if (m->m_len < sizeof(*ip6)) {
806 m = m_pullup(m, sizeof(*ip6));
807 if (!m) {
808 ipsec6stat.in_inval++;
809 goto fail;
810 }
811 }
812 ip6 = mtod(m, struct ip6_hdr *);
813 /* ECN consideration. */
814 if (!ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow)) {
815 ipsec6stat.in_inval++;
816 goto fail;
817 }
818 if (!key_checktunnelsanity(sav, AF_INET6,
819 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
820 ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
821 "in IPv6 AH input: %s %s\n",
822 ipsec6_logpacketstr(ip6, spi),
823 ipsec_logsastr(sav)));
824 ipsec6stat.in_inval++;
825 goto fail;
826 }
827
828 #if 1
829 /*
830 * should the inner packet be considered authentic?
831 * see comment in ah4_input().
832 */
833 m->m_flags &= ~M_AUTHIPHDR;
834 m->m_flags &= ~M_AUTHIPDGM;
835 #endif
836
837 key_sa_recordxfer(sav, m);
838 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
839 ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
840 ipsec6stat.in_nomem++;
841 goto fail;
842 }
843
844 if (netisr_queue(NETISR_IPV6, m)) { /* (0) on success. */
845 ipsec6stat.in_inval++;
846 m = NULL;
847 goto fail;
848 }
849 m = NULL;
850 nxt = IPPROTO_DONE;
851 } else {
852 /*
853 * strip off AH.
854 */
855 u_int8_t *prvnxtp;
856
857 /*
858 * Copy the value of the next header field of AH to the
859 * next header field of the previous header.
860 * This is necessary because AH will be stripped off below.
861 */
862 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
863 *prvnxtp = nxt;
864
865 ip6 = mtod(m, struct ip6_hdr *);
866 #ifndef PULLDOWN_TEST
867 /*
868 * We do deep-copy since KAME requires that
869 * the packet is placed in a single mbuf.
870 */
871 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
872 m->m_data += stripsiz;
873 m->m_len -= stripsiz;
874 m->m_pkthdr.len -= stripsiz;
875 #else
876 /*
877 * even in m_pulldown case, we need to strip off AH so that
878 * we can compute checksum for multiple AH correctly.
879 */
880 if (m->m_len >= stripsiz + off) {
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 * this comes with no copy if the boundary is on
888 * cluster
889 */
890 struct mbuf *n;
891
892 n = m_split(m, off, M_DONTWAIT);
893 if (n == NULL) {
894 /* m is retained by m_split */
895 goto fail;
896 }
897 m_adj(n, stripsiz);
898 /* m_cat does not update m_pkthdr.len */
899 m->m_pkthdr.len += n->m_pkthdr.len;
900 m_cat(m, n);
901 }
902 #endif
903 ip6 = mtod(m, struct ip6_hdr *);
904 /* XXX jumbogram */
905 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
906
907 key_sa_recordxfer(sav, m);
908 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
909 ipsec6stat.in_nomem++;
910 goto fail;
911 }
912 }
913
914 *offp = off;
915 *mp = m;
916
917 if (sav) {
918 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
919 printf("DP ah6_input call free SA:%p\n", sav));
920 key_freesav(sav);
921 }
922 ipsec6stat.in_success++;
923 return nxt;
924
925 fail:
926 if (sav) {
927 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
928 printf("DP ah6_input call free SA:%p\n", sav));
929 key_freesav(sav);
930 }
931 if (m)
932 m_freem(m);
933 return IPPROTO_DONE;
934 }
935
936 void
937 ah6_ctlinput(cmd, sa, d)
938 int cmd;
939 struct sockaddr *sa;
940 void *d;
941 {
942 const struct newah *ahp;
943 struct newah ah;
944 struct secasvar *sav;
945 struct ip6_hdr *ip6;
946 struct mbuf *m;
947 struct ip6ctlparam *ip6cp = NULL;
948 int off;
949 struct sockaddr_in6 *sa6_src, *sa6_dst;
950
951 if (sa->sa_family != AF_INET6 ||
952 sa->sa_len != sizeof(struct sockaddr_in6))
953 return;
954 if ((unsigned)cmd >= PRC_NCMDS)
955 return;
956
957 /* if the parameter is from icmp6, decode it. */
958 if (d != NULL) {
959 ip6cp = (struct ip6ctlparam *)d;
960 m = ip6cp->ip6c_m;
961 ip6 = ip6cp->ip6c_ip6;
962 off = ip6cp->ip6c_off;
963 } else {
964 m = NULL;
965 ip6 = NULL;
966 off = 0; /* calm gcc */
967 }
968
969 if (ip6) {
970 /*
971 * XXX: We assume that when ip6 is non NULL,
972 * M and OFF are valid.
973 */
974
975 /* check if we can safely examine src and dst ports */
976 if (m->m_pkthdr.len < off + sizeof(ah))
977 return;
978
979 if (m->m_len < off + sizeof(ah)) {
980 /*
981 * this should be rare case,
982 * so we compromise on this copy...
983 */
984 m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
985 ahp = &ah;
986 } else
987 ahp = (struct newah *)(mtod(m, caddr_t) + off);
988
989 if (cmd == PRC_MSGSIZE) {
990 int valid = 0;
991
992 /*
993 * Check to see if we have a valid SA corresponding to
994 * the address in the ICMP message payload.
995 */
996 sa6_src = ip6cp->ip6c_src;
997 sa6_dst = (struct sockaddr_in6 *)sa;
998 sav = key_allocsa(AF_INET6,
999 (caddr_t)&sa6_src->sin6_addr,
1000 (caddr_t)&sa6_dst->sin6_addr,
1001 IPPROTO_AH, ahp->ah_spi);
1002 if (sav) {
1003 if (sav->state == SADB_SASTATE_MATURE ||
1004 sav->state == SADB_SASTATE_DYING)
1005 valid++;
1006 key_freesav(sav);
1007 }
1008
1009 /* XXX Further validation? */
1010
1011 /*
1012 * Depending on the value of "valid" and routing table
1013 * size (mtudisc_{hi,lo}wat), we will:
1014 * - recalcurate the new MTU and create the
1015 * corresponding routing entry, or
1016 * - ignore the MTU change notification.
1017 */
1018 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1019 }
1020
1021 /* we normally notify single pcb here */
1022 } else {
1023 /* we normally notify any pcb here */
1024 }
1025 }
1026 #endif /* INET6 */
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