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[apple/xnu.git] / bsd / netinet6 / ah_input.c
1 /* $FreeBSD: src/sys/netinet6/ah_input.c,v 1.1.2.6 2002/04/28 05:40:26 suz Exp $ */
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 <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/domain.h>
42 #include <sys/protosw.h>
43 #include <sys/socket.h>
44 #include <sys/errno.h>
45 #include <sys/time.h>
46 #include <sys/kernel.h>
47 #include <sys/syslog.h>
48
49 #include <net/if.h>
50 #include <net/route.h>
51 #include <kern/cpu_number.h>
52 #include <kern/locks.h>
53
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 #include <netinet/in_var.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_var.h>
59 #include <netinet/ip_ecn.h>
60 #include <netinet/in_pcb.h>
61 #if INET6
62 #include <netinet6/ip6_ecn.h>
63 #endif
64
65 #if INET6
66 #include <netinet/ip6.h>
67 #include <netinet6/ip6_var.h>
68 #include <netinet6/in6_pcb.h>
69 #include <netinet/icmp6.h>
70 #include <netinet6/ip6protosw.h>
71 #endif
72
73 #include <netinet6/ipsec.h>
74 #if INET6
75 #include <netinet6/ipsec6.h>
76 #endif
77 #include <netinet6/ah.h>
78 #if INET6
79 #include <netinet6/ah6.h>
80 #endif
81 #include <netkey/key.h>
82 #include <netkey/keydb.h>
83 #if IPSEC_DEBUG
84 #include <netkey/key_debug.h>
85 #else
86 #define KEYDEBUG(lev,arg)
87 #endif
88
89
90 #include <net/net_osdep.h>
91
92 #define IPLEN_FLIPPED
93
94 extern lck_mtx_t *sadb_mutex;
95 #if INET
96 extern struct protosw inetsw[];
97
98 void
99 ah4_input(struct mbuf *m, int off)
100 {
101 struct ip *ip;
102 struct ah *ah;
103 u_int32_t spi;
104 const struct ah_algorithm *algo;
105 size_t siz;
106 size_t siz1;
107 u_char *cksum;
108 struct secasvar *sav = NULL;
109 u_int16_t nxt;
110 size_t hlen;
111 int s;
112 size_t stripsiz = 0;
113
114 lck_mtx_lock(sadb_mutex);
115
116 #ifndef PULLDOWN_TEST
117 if (m->m_len < off + sizeof(struct newah)) {
118 m = m_pullup(m, off + sizeof(struct newah));
119 if (!m) {
120 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
121 "dropping the packet for simplicity\n"));
122 ipsecstat.in_inval++;
123 goto fail;
124 }
125 }
126
127 ip = mtod(m, struct ip *);
128 ah = (struct ah *)(((caddr_t)ip) + off);
129 #else
130 ip = mtod(m, struct ip *);
131 IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
132 if (ah == NULL) {
133 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
134 "dropping the packet for simplicity\n"));
135 ipsecstat.in_inval++;
136 goto fail;
137 }
138 #endif
139 nxt = ah->ah_nxt;
140 #ifdef _IP_VHL
141 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
142 #else
143 hlen = ip->ip_hl << 2;
144 #endif
145
146 /* find the sassoc. */
147 spi = ah->ah_spi;
148
149 if ((sav = key_allocsa(AF_INET,
150 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
151 IPPROTO_AH, spi)) == 0) {
152 ipseclog((LOG_WARNING,
153 "IPv4 AH input: no key association found for spi %u\n",
154 (u_int32_t)ntohl(spi)));
155 ipsecstat.in_nosa++;
156 goto fail;
157 }
158 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
159 printf("DP ah4_input called to allocate SA:%p\n", sav));
160 if (sav->state != SADB_SASTATE_MATURE
161 && sav->state != SADB_SASTATE_DYING) {
162 ipseclog((LOG_DEBUG,
163 "IPv4 AH input: non-mature/dying SA found for spi %u\n",
164 (u_int32_t)ntohl(spi)));
165 ipsecstat.in_badspi++;
166 goto fail;
167 }
168
169 algo = ah_algorithm_lookup(sav->alg_auth);
170 if (!algo) {
171 ipseclog((LOG_DEBUG, "IPv4 AH input: "
172 "unsupported authentication algorithm for spi %u\n",
173 (u_int32_t)ntohl(spi)));
174 ipsecstat.in_badspi++;
175 goto fail;
176 }
177
178 siz = (*algo->sumsiz)(sav);
179 siz1 = ((siz + 3) & ~(4 - 1));
180
181 /*
182 * sanity checks for header, 1.
183 */
184 {
185 int sizoff;
186
187 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
188
189 /*
190 * Here, we do not do "siz1 == siz". This is because the way
191 * RFC240[34] section 2 is written. They do not require truncation
192 * to 96 bits.
193 * For example, Microsoft IPsec stack attaches 160 bits of
194 * authentication data for both hmac-md5 and hmac-sha1. For hmac-sha1,
195 * 32 bits of padding is attached.
196 *
197 * There are two downsides to this specification.
198 * They have no real harm, however, they leave us fuzzy feeling.
199 * - if we attach more than 96 bits of authentication data onto AH,
200 * we will never notice about possible modification by rogue
201 * intermediate nodes.
202 * Since extra bits in AH checksum is never used, this constitutes
203 * no real issue, however, it is wacky.
204 * - even if the peer attaches big authentication data, we will never
205 * notice the difference, since longer authentication data will just
206 * work.
207 *
208 * We may need some clarification in the spec.
209 */
210 if (siz1 < siz) {
211 ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
212 "(%lu, should be at least %lu): %s\n",
213 (u_long)siz1, (u_long)siz,
214 ipsec4_logpacketstr(ip, spi)));
215 ipsecstat.in_inval++;
216 goto fail;
217 }
218 if ((ah->ah_len << 2) - sizoff != siz1) {
219 ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
220 "(%d should be %lu): %s\n",
221 (ah->ah_len << 2) - sizoff, (u_long)siz1,
222 ipsec4_logpacketstr(ip, spi)));
223 ipsecstat.in_inval++;
224 goto fail;
225 }
226
227 #ifndef PULLDOWN_TEST
228 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
229 m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
230 if (!m) {
231 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
232 ipsecstat.in_inval++;
233 goto fail;
234 }
235
236 ip = mtod(m, struct ip *);
237 ah = (struct ah *)(((caddr_t)ip) + off);
238 }
239 #else
240 IP6_EXTHDR_GET(ah, struct ah *, m, off,
241 sizeof(struct ah) + sizoff + siz1);
242 if (ah == NULL) {
243 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
244 ipsecstat.in_inval++;
245 goto fail;
246 }
247 #endif
248 }
249
250 /*
251 * check for sequence number.
252 */
253 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
254 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
255 ; /*okey*/
256 else {
257 ipsecstat.in_ahreplay++;
258 ipseclog((LOG_WARNING,
259 "replay packet in IPv4 AH input: %s %s\n",
260 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
261 goto fail;
262 }
263 }
264
265 /*
266 * alright, it seems sane. now we are going to check the
267 * cryptographic checksum.
268 */
269 cksum = _MALLOC(siz1, M_TEMP, M_NOWAIT);
270 if (!cksum) {
271 ipseclog((LOG_DEBUG, "IPv4 AH input: "
272 "couldn't alloc temporary region for cksum\n"));
273 ipsecstat.in_inval++;
274 goto fail;
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, (caddr_t)cksum, siz1, algo, sav)) {
284 FREE(cksum, M_TEMP);
285 ipsecstat.in_inval++;
286 goto fail;
287 }
288 ipsecstat.in_ahhist[sav->alg_auth]++;
289 /*
290 * flip them back.
291 */
292 ip->ip_len = ntohs(ip->ip_len) - hlen;
293 ip->ip_off = ntohs(ip->ip_off);
294
295 {
296 caddr_t sumpos = NULL;
297
298 if (sav->flags & SADB_X_EXT_OLD) {
299 /* RFC 1826 */
300 sumpos = (caddr_t)(ah + 1);
301 } else {
302 /* RFC 2402 */
303 sumpos = (caddr_t)(((struct newah *)ah) + 1);
304 }
305
306 if (bcmp(sumpos, cksum, siz) != 0) {
307 ipseclog((LOG_WARNING,
308 "checksum mismatch in IPv4 AH input: %s %s\n",
309 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
310 FREE(cksum, M_TEMP);
311 ipsecstat.in_ahauthfail++;
312 goto fail;
313 }
314 }
315
316 FREE(cksum, M_TEMP);
317
318 m->m_flags |= M_AUTHIPHDR;
319 m->m_flags |= M_AUTHIPDGM;
320
321 #if 0
322 /*
323 * looks okey, but we need more sanity check.
324 * XXX should elaborate.
325 */
326 if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
327 struct ip *nip;
328 size_t sizoff;
329
330 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
331
332 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
333 m = m_pullup(m, off + sizeof(struct ah)
334 + sizoff + siz1 + hlen);
335 if (!m) {
336 ipseclog((LOG_DEBUG,
337 "IPv4 AH input: can't pullup\n"));
338 ipsecstat.in_inval++;
339 goto fail;
340 }
341 }
342
343 nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
344 if (nip->ip_src.s_addr != ip->ip_src.s_addr
345 || nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
346 m->m_flags &= ~M_AUTHIPHDR;
347 m->m_flags &= ~M_AUTHIPDGM;
348 }
349 }
350 #if INET6
351 else if (ah->ah_nxt == IPPROTO_IPV6) {
352 m->m_flags &= ~M_AUTHIPHDR;
353 m->m_flags &= ~M_AUTHIPDGM;
354 }
355 #endif /*INET6*/
356 #endif /*0*/
357
358 if (m->m_flags & M_AUTHIPHDR
359 && m->m_flags & M_AUTHIPDGM) {
360 #if 0
361 ipseclog((LOG_DEBUG,
362 "IPv4 AH input: authentication succeess\n"));
363 #endif
364 ipsecstat.in_ahauthsucc++;
365 } else {
366 ipseclog((LOG_WARNING,
367 "authentication failed in IPv4 AH input: %s %s\n",
368 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
369 ipsecstat.in_ahauthfail++;
370 goto fail;
371 }
372
373 /*
374 * update sequence number.
375 */
376 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
377 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
378 ipsecstat.in_ahreplay++;
379 goto fail;
380 }
381 }
382
383 /* was it transmitted over the IPsec tunnel SA? */
384 if (sav->flags & SADB_X_EXT_OLD) {
385 /* RFC 1826 */
386 stripsiz = sizeof(struct ah) + siz1;
387 } else {
388 /* RFC 2402 */
389 stripsiz = sizeof(struct newah) + siz1;
390 }
391 if (ipsec4_tunnel_validate(m, off + stripsiz, nxt, sav)) {
392 /*
393 * strip off all the headers that precedes AH.
394 * IP xx AH IP' payload -> IP' payload
395 *
396 * XXX more sanity checks
397 * XXX relationship with gif?
398 */
399 u_int8_t tos;
400
401 tos = ip->ip_tos;
402 m_adj(m, off + stripsiz);
403 if (m->m_len < sizeof(*ip)) {
404 m = m_pullup(m, sizeof(*ip));
405 if (!m) {
406 ipsecstat.in_inval++;
407 goto fail;
408 }
409 }
410 ip = mtod(m, struct ip *);
411 /* ECN consideration. */
412 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
413 if (!key_checktunnelsanity(sav, AF_INET,
414 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
415 ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
416 "in IPv4 AH input: %s %s\n",
417 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
418 ipsecstat.in_inval++;
419 goto fail;
420 }
421
422 #if 1
423 /*
424 * Should the inner packet be considered authentic?
425 * My current answer is: NO.
426 *
427 * host1 -- gw1 === gw2 -- host2
428 * In this case, gw2 can trust the authenticity of the
429 * outer packet, but NOT inner. Packet may be altered
430 * between host1 and gw1.
431 *
432 * host1 -- gw1 === host2
433 * This case falls into the same scenario as above.
434 *
435 * host1 === host2
436 * This case is the only case when we may be able to leave
437 * M_AUTHIPHDR and M_AUTHIPDGM set.
438 * However, if host1 is wrongly configured, and allows
439 * attacker to inject some packet with src=host1 and
440 * dst=host2, you are in risk.
441 */
442 m->m_flags &= ~M_AUTHIPHDR;
443 m->m_flags &= ~M_AUTHIPDGM;
444 #endif
445
446 key_sa_recordxfer(sav, m);
447 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
448 ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
449 ipsecstat.in_nomem++;
450 goto fail;
451 }
452 lck_mtx_unlock(sadb_mutex);
453 proto_input(PF_INET, m);
454 lck_mtx_lock(sadb_mutex);
455 nxt = IPPROTO_DONE;
456 } else {
457 /*
458 * strip off AH.
459 */
460
461 ip = mtod(m, struct ip *);
462 #ifndef PULLDOWN_TEST
463 /*
464 * We do deep-copy since KAME requires that
465 * the packet is placed in a single external mbuf.
466 */
467 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
468 m->m_data += stripsiz;
469 m->m_len -= stripsiz;
470 m->m_pkthdr.len -= stripsiz;
471 #else
472 /*
473 * even in m_pulldown case, we need to strip off AH so that
474 * we can compute checksum for multiple AH correctly.
475 */
476 if (m->m_len >= stripsiz + off) {
477 ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
478 m->m_data += stripsiz;
479 m->m_len -= stripsiz;
480 m->m_pkthdr.len -= stripsiz;
481 } else {
482 /*
483 * this comes with no copy if the boundary is on
484 * cluster
485 */
486 struct mbuf *n;
487
488 n = m_split(m, off, M_DONTWAIT);
489 if (n == NULL) {
490 /* m is retained by m_split */
491 goto fail;
492 }
493 m_adj(n, stripsiz);
494 /* m_cat does not update m_pkthdr.len */
495 m->m_pkthdr.len += n->m_pkthdr.len;
496 m_cat(m, n);
497 }
498 #endif
499
500 if (m->m_len < sizeof(*ip)) {
501 m = m_pullup(m, sizeof(*ip));
502 if (m == NULL) {
503 ipsecstat.in_inval++;
504 goto fail;
505 }
506 }
507 ip = mtod(m, struct ip *);
508 #ifdef IPLEN_FLIPPED
509 ip->ip_len = ip->ip_len - stripsiz;
510 #else
511 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
512 #endif
513 ip->ip_p = nxt;
514 /* forget about IP hdr checksum, the check has already been passed */
515
516 key_sa_recordxfer(sav, m);
517 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
518 ipsecstat.in_nomem++;
519 goto fail;
520 }
521
522 if (nxt != IPPROTO_DONE) {
523 if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
524 ipsec4_in_reject(m, NULL)) {
525 ipsecstat.in_polvio++;
526 goto fail;
527 }
528 lck_mtx_unlock(sadb_mutex);
529 ip_proto_dispatch_in(m, off, nxt, 0);
530 lck_mtx_lock(sadb_mutex);
531 } else
532 m_freem(m);
533 m = NULL;
534 }
535
536 if (sav) {
537 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
538 printf("DP ah4_input call free SA:%p\n", sav));
539 key_freesav(sav);
540 }
541 ipsecstat.in_success++;
542 lck_mtx_unlock(sadb_mutex);
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 lck_mtx_unlock(sadb_mutex);
552 if (m)
553 m_freem(m);
554 return;
555 }
556 #endif /* INET */
557
558 #if INET6
559 int
560 ah6_input(mp, offp)
561 struct mbuf **mp;
562 int *offp;
563 {
564 struct mbuf *m = *mp;
565 int off = *offp;
566 struct ip6_hdr *ip6;
567 struct ah *ah;
568 u_int32_t spi;
569 const struct ah_algorithm *algo;
570 size_t siz;
571 size_t siz1;
572 u_char *cksum;
573 struct secasvar *sav = NULL;
574 u_int16_t nxt;
575 int s;
576 size_t stripsiz = 0;
577
578 lck_mtx_lock(sadb_mutex);
579
580 #ifndef PULLDOWN_TEST
581 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), {lck_mtx_unlock(sadb_mutex);return IPPROTO_DONE;});
582 ah = (struct ah *)(mtod(m, caddr_t) + off);
583 #else
584 IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
585 if (ah == NULL) {
586 ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
587 ipsec6stat.in_inval++;
588 lck_mtx_unlock(sadb_mutex);
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,
667 {lck_mtx_unlock(sadb_mutex);return IPPROTO_DONE;});
668 #else
669 IP6_EXTHDR_GET(ah, struct ah *, m, off,
670 sizeof(struct ah) + sizoff + siz1);
671 if (ah == NULL) {
672 ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
673 ipsec6stat.in_inval++;
674 m = NULL;
675 goto fail;
676 }
677 #endif
678 }
679
680 /*
681 * check for sequence number.
682 */
683 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
684 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
685 ; /*okey*/
686 else {
687 ipsec6stat.in_ahreplay++;
688 ipseclog((LOG_WARNING,
689 "replay packet in IPv6 AH input: %s %s\n",
690 ipsec6_logpacketstr(ip6, spi),
691 ipsec_logsastr(sav)));
692 goto fail;
693 }
694 }
695
696 /*
697 * alright, it seems sane. now we are going to check the
698 * cryptographic checksum.
699 */
700 cksum = _MALLOC(siz1, M_TEMP, M_NOWAIT);
701 if (!cksum) {
702 ipseclog((LOG_DEBUG, "IPv6 AH input: "
703 "couldn't alloc temporary region for cksum\n"));
704 ipsec6stat.in_inval++;
705 goto fail;
706 }
707
708 if (ah6_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
709 FREE(cksum, M_TEMP);
710 ipsec6stat.in_inval++;
711 goto fail;
712 }
713 ipsec6stat.in_ahhist[sav->alg_auth]++;
714
715 {
716 caddr_t sumpos = NULL;
717
718 if (sav->flags & SADB_X_EXT_OLD) {
719 /* RFC 1826 */
720 sumpos = (caddr_t)(ah + 1);
721 } else {
722 /* RFC 2402 */
723 sumpos = (caddr_t)(((struct newah *)ah) + 1);
724 }
725
726 if (bcmp(sumpos, cksum, siz) != 0) {
727 ipseclog((LOG_WARNING,
728 "checksum mismatch in IPv6 AH input: %s %s\n",
729 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
730 FREE(cksum, M_TEMP);
731 ipsec6stat.in_ahauthfail++;
732 goto fail;
733 }
734 }
735
736 FREE(cksum, M_TEMP);
737
738 m->m_flags |= M_AUTHIPHDR;
739 m->m_flags |= M_AUTHIPDGM;
740
741 #if 0
742 /*
743 * looks okey, but we need more sanity check.
744 * XXX should elaborate.
745 */
746 if (ah->ah_nxt == IPPROTO_IPV6) {
747 struct ip6_hdr *nip6;
748 size_t sizoff;
749
750 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
751
752 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
753 + sizeof(struct ip6_hdr),
754 {lck_mtx_unlock(sadb_mutex);return IPPROTO_DONE;});
755
756 nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
757 if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
758 || !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
759 m->m_flags &= ~M_AUTHIPHDR;
760 m->m_flags &= ~M_AUTHIPDGM;
761 }
762 } else if (ah->ah_nxt == IPPROTO_IPIP) {
763 m->m_flags &= ~M_AUTHIPHDR;
764 m->m_flags &= ~M_AUTHIPDGM;
765 } else if (ah->ah_nxt == IPPROTO_IP) {
766 m->m_flags &= ~M_AUTHIPHDR;
767 m->m_flags &= ~M_AUTHIPDGM;
768 }
769 #endif
770
771 if (m->m_flags & M_AUTHIPHDR
772 && m->m_flags & M_AUTHIPDGM) {
773 #if 0
774 ipseclog((LOG_DEBUG,
775 "IPv6 AH input: authentication succeess\n"));
776 #endif
777 ipsec6stat.in_ahauthsucc++;
778 } else {
779 ipseclog((LOG_WARNING,
780 "authentication failed in IPv6 AH input: %s %s\n",
781 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
782 ipsec6stat.in_ahauthfail++;
783 goto fail;
784 }
785
786 /*
787 * update sequence number.
788 */
789 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
790 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
791 ipsec6stat.in_ahreplay++;
792 goto fail;
793 }
794 }
795
796 /* was it transmitted over the IPsec tunnel SA? */
797 if (sav->flags & SADB_X_EXT_OLD) {
798 /* RFC 1826 */
799 stripsiz = sizeof(struct ah) + siz1;
800 } else {
801 /* RFC 2402 */
802 stripsiz = sizeof(struct newah) + siz1;
803 }
804 if (ipsec6_tunnel_validate(m, off + stripsiz, nxt, sav)) {
805 /*
806 * strip off all the headers that precedes AH.
807 * IP6 xx AH IP6' payload -> IP6' payload
808 *
809 * XXX more sanity checks
810 * XXX relationship with gif?
811 */
812 u_int32_t flowinfo; /*net endian*/
813
814 flowinfo = ip6->ip6_flow;
815 m_adj(m, off + stripsiz);
816 if (m->m_len < sizeof(*ip6)) {
817 /*
818 * m_pullup is prohibited in KAME IPv6 input processing
819 * but there's no other way!
820 */
821 m = m_pullup(m, sizeof(*ip6));
822 if (!m) {
823 ipsec6stat.in_inval++;
824 goto fail;
825 }
826 }
827 ip6 = mtod(m, struct ip6_hdr *);
828 /* ECN consideration. */
829 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
830 if (!key_checktunnelsanity(sav, AF_INET6,
831 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
832 ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
833 "in IPv6 AH input: %s %s\n",
834 ipsec6_logpacketstr(ip6, spi),
835 ipsec_logsastr(sav)));
836 ipsec6stat.in_inval++;
837 goto fail;
838 }
839
840 #if 1
841 /*
842 * should the inner packet be considered authentic?
843 * see comment in ah4_input().
844 */
845 m->m_flags &= ~M_AUTHIPHDR;
846 m->m_flags &= ~M_AUTHIPDGM;
847 #endif
848
849 key_sa_recordxfer(sav, m);
850 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
851 ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
852 ipsec6stat.in_nomem++;
853 goto fail;
854 }
855 lck_mtx_unlock(sadb_mutex);
856 proto_input(PF_INET6, m);
857 lck_mtx_lock(sadb_mutex);
858 nxt = IPPROTO_DONE;
859 } else {
860 /*
861 * strip off AH.
862 */
863 char *prvnxtp;
864
865 /*
866 * Copy the value of the next header field of AH to the
867 * next header field of the previous header.
868 * This is necessary because AH will be stripped off below.
869 */
870 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
871 *prvnxtp = nxt;
872
873 ip6 = mtod(m, struct ip6_hdr *);
874 #ifndef PULLDOWN_TEST
875 /*
876 * We do deep-copy since KAME requires that
877 * the packet is placed in a single mbuf.
878 */
879 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
880 m->m_data += stripsiz;
881 m->m_len -= stripsiz;
882 m->m_pkthdr.len -= stripsiz;
883 #else
884 /*
885 * even in m_pulldown case, we need to strip off AH so that
886 * we can compute checksum for multiple AH correctly.
887 */
888 if (m->m_len >= stripsiz + off) {
889 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
890 m->m_data += stripsiz;
891 m->m_len -= stripsiz;
892 m->m_pkthdr.len -= stripsiz;
893 } else {
894 /*
895 * this comes with no copy if the boundary is on
896 * cluster
897 */
898 struct mbuf *n;
899
900 n = m_split(m, off, M_DONTWAIT);
901 if (n == NULL) {
902 /* m is retained by m_split */
903 goto fail;
904 }
905 m_adj(n, stripsiz);
906 /* m_cat does not update m_pkthdr.len */
907 m->m_pkthdr.len += n->m_pkthdr.len;
908 m_cat(m, n);
909 }
910 #endif
911 ip6 = mtod(m, struct ip6_hdr *);
912 /* XXX jumbogram */
913 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
914
915 key_sa_recordxfer(sav, m);
916 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
917 ipsec6stat.in_nomem++;
918 goto fail;
919 }
920 }
921
922 *offp = off;
923 *mp = m;
924
925 if (sav) {
926 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
927 printf("DP ah6_input call free SA:%p\n", sav));
928 key_freesav(sav);
929 }
930 ipsec6stat.in_success++;
931 lck_mtx_unlock(sadb_mutex);
932 return nxt;
933
934 fail:
935 if (sav) {
936 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
937 printf("DP ah6_input call free SA:%p\n", sav));
938 key_freesav(sav);
939 }
940 lck_mtx_unlock(sadb_mutex);
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 }
977
978 if (ip6) {
979 /*
980 * XXX: We assume that when ip6 is non NULL,
981 * M and OFF are valid.
982 */
983
984 /* check if we can safely examine src and dst ports */
985 if (m->m_pkthdr.len < off + sizeof(ah))
986 return;
987
988 if (m->m_len < off + sizeof(ah)) {
989 /*
990 * this should be rare case,
991 * so we compromise on this copy...
992 */
993 m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
994 ahp = &ah;
995 } else
996 ahp = (struct newah *)(mtod(m, caddr_t) + off);
997
998 if (cmd == PRC_MSGSIZE) {
999 int valid = 0;
1000
1001 /*
1002 * Check to see if we have a valid SA corresponding to
1003 * the address in the ICMP message payload.
1004 */
1005 sa6_src = ip6cp->ip6c_src;
1006 sa6_dst = (struct sockaddr_in6 *)sa;
1007 lck_mtx_lock(sadb_mutex);
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 lck_mtx_unlock(sadb_mutex);
1019
1020 /* XXX Further validation? */
1021
1022 /*
1023 * Depending on the value of "valid" and routing table
1024 * size (mtudisc_{hi,lo}wat), we will:
1025 * - recalcurate the new MTU and create the
1026 * corresponding routing entry, or
1027 * - ignore the MTU change notification.
1028 */
1029 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1030 }
1031
1032 /* we normally notify single pcb here */
1033 } else {
1034 /* we normally notify any pcb here */
1035 }
1036 }
1037 #endif /* INET6 */
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