1 /* $FreeBSD: releng/6.3/sys/netipsec/ipsec_input.c 160632 2006-07-24 23:20:59Z thompsa $ */
2 /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */
3 /*-
4 * The authors of this code are John Ioannidis (ji@tla.org),
5 * Angelos D. Keromytis (kermit@csd.uch.gr) and
6 * Niels Provos (provos@physnet.uni-hamburg.de).
7 *
8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
9 * in November 1995.
10 *
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
13 *
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
15 * and Niels Provos.
16 *
17 * Additional features in 1999 by Angelos D. Keromytis.
18 *
19 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
20 * Angelos D. Keromytis and Niels Provos.
21 * Copyright (c) 2001, Angelos D. Keromytis.
22 *
23 * Permission to use, copy, and modify this software with or without fee
24 * is hereby granted, provided that this entire notice is included in
25 * all copies of any software which is or includes a copy or
26 * modification of this software.
27 * You may use this code under the GNU public license if you so wish. Please
28 * contribute changes back to the authors under this freer than GPL license
29 * so that we may further the use of strong encryption without limitations to
30 * all.
31 *
32 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
33 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
34 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
35 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
36 * PURPOSE.
37 */
38
39 /*
40 * IPsec input processing.
41 */
42
43 #include "opt_inet.h"
44 #include "opt_inet6.h"
45 #include "opt_ipsec.h"
46 #include "opt_enc.h"
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/malloc.h>
51 #include <sys/mbuf.h>
52 #include <sys/domain.h>
53 #include <sys/protosw.h>
54 #include <sys/socket.h>
55 #include <sys/errno.h>
56 #include <sys/syslog.h>
57
58 #include <net/if.h>
59 #include <net/route.h>
60 #include <net/netisr.h>
61
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/ip.h>
65 #include <netinet/ip_var.h>
66 #include <netinet/in_var.h>
67
68 #include <netinet/ip6.h>
69 #ifdef INET6
70 #include <netinet6/ip6_var.h>
71 #endif
72 #include <netinet/in_pcb.h>
73 #ifdef INET6
74 #include <netinet/icmp6.h>
75 #endif
76
77 #include <netipsec/ipsec.h>
78 #ifdef INET6
79 #include <netipsec/ipsec6.h>
80 #endif
81 #include <netipsec/ah_var.h>
82 #include <netipsec/esp.h>
83 #include <netipsec/esp_var.h>
84 #include <netipsec/ipcomp_var.h>
85
86 #include <netipsec/key.h>
87 #include <netipsec/keydb.h>
88
89 #include <netipsec/xform.h>
90 #include <netinet6/ip6protosw.h>
91
92 #include <machine/in_cksum.h>
93 #include <machine/stdarg.h>
94
95 #define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \
96 (p) == IPPROTO_AH ? (y)++ : (z)++)
97
98 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
99
100 /*
101 * ipsec_common_input gets called when an IPsec-protected packet
102 * is received by IPv4 or IPv6. It's job is to find the right SA
103 # and call the appropriate transform. The transform callback
104 * takes care of further processing (like ingress filtering).
105 */
106 static int
107 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
108 {
109 union sockaddr_union dst_address;
110 struct secasvar *sav;
111 u_int32_t spi;
112 int error;
113
114 IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input,
115 ipcompstat.ipcomps_input);
116
117 IPSEC_ASSERT(m != NULL, ("null packet"));
118
119 if ((sproto == IPPROTO_ESP && !esp_enable) ||
120 (sproto == IPPROTO_AH && !ah_enable) ||
121 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) {
122 m_freem(m);
123 IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops,
124 ipcompstat.ipcomps_pdrops);
125 return EOPNOTSUPP;
126 }
127
128 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
129 m_freem(m);
130 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
131 ipcompstat.ipcomps_hdrops);
132 DPRINTF(("%s: packet too small\n", __func__));
133 return EINVAL;
134 }
135
136 /* Retrieve the SPI from the relevant IPsec header */
137 if (sproto == IPPROTO_ESP)
138 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
139 else if (sproto == IPPROTO_AH)
140 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
141 (caddr_t) &spi);
142 else if (sproto == IPPROTO_IPCOMP) {
143 u_int16_t cpi;
144 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
145 (caddr_t) &cpi);
146 spi = ntohl(htons(cpi));
147 }
148
149 /*
150 * Find the SA and (indirectly) call the appropriate
151 * kernel crypto routine. The resulting mbuf chain is a valid
152 * IP packet ready to go through input processing.
153 */
154 bzero(&dst_address, sizeof (dst_address));
155 dst_address.sa.sa_family = af;
156 switch (af) {
157 #ifdef INET
158 case AF_INET:
159 dst_address.sin.sin_len = sizeof(struct sockaddr_in);
160 m_copydata(m, offsetof(struct ip, ip_dst),
161 sizeof(struct in_addr),
162 (caddr_t) &dst_address.sin.sin_addr);
163 break;
164 #endif /* INET */
165 #ifdef INET6
166 case AF_INET6:
167 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
168 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
169 sizeof(struct in6_addr),
170 (caddr_t) &dst_address.sin6.sin6_addr);
171 break;
172 #endif /* INET6 */
173 default:
174 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
175 m_freem(m);
176 IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf,
177 ipcompstat.ipcomps_nopf);
178 return EPFNOSUPPORT;
179 }
180
181 /* NB: only pass dst since key_allocsa follows RFC2401 */
182 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
183 if (sav == NULL) {
184 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
185 __func__, ipsec_address(&dst_address),
186 (u_long) ntohl(spi), sproto));
187 IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb,
188 ipcompstat.ipcomps_notdb);
189 m_freem(m);
190 return ENOENT;
191 }
192
193 if (sav->tdb_xform == NULL) {
194 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
195 __func__, ipsec_address(&dst_address),
196 (u_long) ntohl(spi), sproto));
197 IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform,
198 ipcompstat.ipcomps_noxform);
199 KEY_FREESAV(&sav);
200 m_freem(m);
201 return ENXIO;
202 }
203
204 /*
205 * Call appropriate transform and return -- callback takes care of
206 * everything else.
207 */
208 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
209 KEY_FREESAV(&sav);
210 return error;
211 }
212
213 #ifdef INET
214 /*
215 * Common input handler for IPv4 AH, ESP, and IPCOMP.
216 */
217 int
218 ipsec4_common_input(struct mbuf *m, ...)
219 {
220 va_list ap;
221 int off, nxt;
222
223 va_start(ap, m);
224 off = va_arg(ap, int);
225 nxt = va_arg(ap, int);
226 va_end(ap);
227
228 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
229 AF_INET, nxt);
230 }
231
232 void
233 ah4_input(struct mbuf *m, int off)
234 {
235 ipsec4_common_input(m, off, IPPROTO_AH);
236 }
237 void
238 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
239 {
240 if (sa->sa_family == AF_INET &&
241 sa->sa_len == sizeof(struct sockaddr_in))
242 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
243 }
244
245 void
246 esp4_input(struct mbuf *m, int off)
247 {
248 ipsec4_common_input(m, off, IPPROTO_ESP);
249 }
250 void
251 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
252 {
253 if (sa->sa_family == AF_INET &&
254 sa->sa_len == sizeof(struct sockaddr_in))
255 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
256 }
257
258 void
259 ipcomp4_input(struct mbuf *m, int off)
260 {
261 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
262 }
263
264 /*
265 * IPsec input callback for INET protocols.
266 * This routine is called as the transform callback.
267 * Takes care of filtering and other sanity checks on
268 * the processed packet.
269 */
270 int
271 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
272 int skip, int protoff, struct m_tag *mt)
273 {
274 int prot, af, sproto;
275 struct ip *ip;
276 struct m_tag *mtag;
277 struct tdb_ident *tdbi;
278 struct secasindex *saidx;
279 int error;
280
281 IPSEC_SPLASSERT_SOFTNET(__func__);
282
283 IPSEC_ASSERT(m != NULL, ("null mbuf"));
284 IPSEC_ASSERT(sav != NULL, ("null SA"));
285 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
286 saidx = &sav->sah->saidx;
287 af = saidx->dst.sa.sa_family;
288 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
289 sproto = saidx->proto;
290 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
291 sproto == IPPROTO_IPCOMP,
292 ("unexpected security protocol %u", sproto));
293
294 /* Sanity check */
295 if (m == NULL) {
296 DPRINTF(("%s: null mbuf", __func__));
297 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
298 ipcompstat.ipcomps_badkcr);
299 KEY_FREESAV(&sav);
300 return EINVAL;
301 }
302
303 if (skip != 0) {
304 /* Fix IPv4 header */
305 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
306 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
307 __func__, ipsec_address(&sav->sah->saidx.dst),
308 (u_long) ntohl(sav->spi)));
309 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
310 ipcompstat.ipcomps_hdrops);
311 error = ENOBUFS;
312 goto bad;
313 }
314
315 ip = mtod(m, struct ip *);
316 ip->ip_len = htons(m->m_pkthdr.len);
317 ip->ip_off = htons(ip->ip_off);
318 ip->ip_sum = 0;
319 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
320 } else {
321 ip = mtod(m, struct ip *);
322 }
323 prot = ip->ip_p;
324
325 #ifdef notyet
326 /* IP-in-IP encapsulation */
327 if (prot == IPPROTO_IPIP) {
328 struct ip ipn;
329
330 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
331 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
332 ahstat.ahs_hdrops,
333 ipcompstat.ipcomps_hdrops);
334 error = EINVAL;
335 goto bad;
336 }
337 /* ipn will now contain the inner IPv4 header */
338 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
339 (caddr_t) &ipn);
340
341 /* XXX PROXY address isn't recorded in SAH */
342 /*
343 * Check that the inner source address is the same as
344 * the proxy address, if available.
345 */
346 if ((saidx->proxy.sa.sa_family == AF_INET &&
347 saidx->proxy.sin.sin_addr.s_addr !=
348 INADDR_ANY &&
349 ipn.ip_src.s_addr !=
350 saidx->proxy.sin.sin_addr.s_addr) ||
351 (saidx->proxy.sa.sa_family != AF_INET &&
352 saidx->proxy.sa.sa_family != 0)) {
353
354 DPRINTF(("%s: inner source address %s doesn't "
355 "correspond to expected proxy source %s, "
356 "SA %s/%08lx\n", __func__,
357 inet_ntoa4(ipn.ip_src),
358 ipsp_address(saidx->proxy),
359 ipsp_address(saidx->dst),
360 (u_long) ntohl(sav->spi)));
361
362 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
363 ahstat.ahs_pdrops,
364 ipcompstat.ipcomps_pdrops);
365 error = EACCES;
366 goto bad;
367 }
368 }
369 #ifdef INET6
370 /* IPv6-in-IP encapsulation. */
371 if (prot == IPPROTO_IPV6) {
372 struct ip6_hdr ip6n;
373
374 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
375 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
376 ahstat.ahs_hdrops,
377 ipcompstat.ipcomps_hdrops);
378 error = EINVAL;
379 goto bad;
380 }
381 /* ip6n will now contain the inner IPv6 header. */
382 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
383 (caddr_t) &ip6n);
384
385 /*
386 * Check that the inner source address is the same as
387 * the proxy address, if available.
388 */
389 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
390 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
391 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
392 &saidx->proxy.sin6.sin6_addr)) ||
393 (saidx->proxy.sa.sa_family != AF_INET6 &&
394 saidx->proxy.sa.sa_family != 0)) {
395
396 DPRINTF(("%s: inner source address %s doesn't "
397 "correspond to expected proxy source %s, "
398 "SA %s/%08lx\n", __func__,
399 ip6_sprintf(&ip6n.ip6_src),
400 ipsec_address(&saidx->proxy),
401 ipsec_address(&saidx->dst),
402 (u_long) ntohl(sav->spi)));
403
404 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
405 ahstat.ahs_pdrops,
406 ipcompstat.ipcomps_pdrops);
407 error = EACCES;
408 goto bad;
409 }
410 }
411 #endif /* INET6 */
412 #endif /*XXX*/
413
414 /*
415 * Record what we've done to the packet (under what SA it was
416 * processed). If we've been passed an mtag, it means the packet
417 * was already processed by an ethernet/crypto combo card and
418 * thus has a tag attached with all the right information, but
419 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
420 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
421 */
422 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
423 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
424 sizeof(struct tdb_ident), M_NOWAIT);
425 if (mtag == NULL) {
426 DPRINTF(("%s: failed to get tag\n", __func__));
427 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
428 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
429 error = ENOMEM;
430 goto bad;
431 }
432
433 tdbi = (struct tdb_ident *)(mtag + 1);
434 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
435 tdbi->proto = sproto;
436 tdbi->spi = sav->spi;
437
438 m_tag_prepend(m, mtag);
439 } else {
440 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
441 /* XXX do we need to mark m_flags??? */
442 }
443
444 key_sa_recordxfer(sav, m); /* record data transfer */
445
446 #ifdef DEV_ENC
447 /*
448 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
449 * packet later after it has been decapsulated.
450 */
451 ipsec_bpf(m, sav, AF_INET);
452
453 if (prot != IPPROTO_IPIP)
454 if ((error = ipsec_filter(&m, 1)) != 0)
455 return (error);
456 #endif
457
458 /*
459 * Re-dispatch via software interrupt.
460 */
461 if ((error = netisr_queue(NETISR_IP, m))) {
462 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull,
463 ipcompstat.ipcomps_qfull);
464
465 DPRINTF(("%s: queue full; proto %u packet dropped\n",
466 __func__, sproto));
467 return error;
468 }
469 return 0;
470 bad:
471 m_freem(m);
472 return error;
473 }
474
475 void
476 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
477 {
478 /* XXX nothing just yet */
479 }
480 #endif /* INET */
481
482 #ifdef INET6
483 /* IPv6 AH wrapper. */
484 int
485 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
486 {
487 int l = 0;
488 int protoff;
489 struct ip6_ext ip6e;
490
491 if (*offp < sizeof(struct ip6_hdr)) {
492 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
493 return IPPROTO_DONE;
494 } else if (*offp == sizeof(struct ip6_hdr)) {
495 protoff = offsetof(struct ip6_hdr, ip6_nxt);
496 } else {
497 /* Chase down the header chain... */
498 protoff = sizeof(struct ip6_hdr);
499
500 do {
501 protoff += l;
502 m_copydata(*mp, protoff, sizeof(ip6e),
503 (caddr_t) &ip6e);
504
505 if (ip6e.ip6e_nxt == IPPROTO_AH)
506 l = (ip6e.ip6e_len + 2) << 2;
507 else
508 l = (ip6e.ip6e_len + 1) << 3;
509 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
510 } while (protoff + l < *offp);
511
512 /* Malformed packet check */
513 if (protoff + l != *offp) {
514 DPRINTF(("%s: bad packet header chain, protoff %u, "
515 "l %u, off %u\n", __func__, protoff, l, *offp));
516 IPSEC_ISTAT(proto, espstat.esps_hdrops,
517 ahstat.ahs_hdrops,
518 ipcompstat.ipcomps_hdrops);
519 m_freem(*mp);
520 *mp = NULL;
521 return IPPROTO_DONE;
522 }
523 protoff += offsetof(struct ip6_ext, ip6e_nxt);
524 }
525 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
526 return IPPROTO_DONE;
527 }
528
529 /*
530 * IPsec input callback, called by the transform callback. Takes care of
531 * filtering and other sanity checks on the processed packet.
532 */
533 int
534 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
535 struct m_tag *mt)
536 {
537 int prot, af, sproto;
538 struct ip6_hdr *ip6;
539 struct m_tag *mtag;
540 struct tdb_ident *tdbi;
541 struct secasindex *saidx;
542 int nxt;
543 u_int8_t nxt8;
544 int error, nest;
545
546 IPSEC_ASSERT(m != NULL, ("null mbuf"));
547 IPSEC_ASSERT(sav != NULL, ("null SA"));
548 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
549 saidx = &sav->sah->saidx;
550 af = saidx->dst.sa.sa_family;
551 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
552 sproto = saidx->proto;
553 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
554 sproto == IPPROTO_IPCOMP,
555 ("unexpected security protocol %u", sproto));
556
557 /* Sanity check */
558 if (m == NULL) {
559 DPRINTF(("%s: null mbuf", __func__));
560 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
561 ipcompstat.ipcomps_badkcr);
562 error = EINVAL;
563 goto bad;
564 }
565
566 /* Fix IPv6 header */
567 if (m->m_len < sizeof(struct ip6_hdr) &&
568 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
569
570 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
571 __func__, ipsec_address(&sav->sah->saidx.dst),
572 (u_long) ntohl(sav->spi)));
573
574 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
575 ipcompstat.ipcomps_hdrops);
576 error = EACCES;
577 goto bad;
578 }
579
580 ip6 = mtod(m, struct ip6_hdr *);
581 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
582
583 /* Save protocol */
584 m_copydata(m, protoff, 1, (unsigned char *) &prot);
585
586 #ifdef notyet
587 #ifdef INET
588 /* IP-in-IP encapsulation */
589 if (prot == IPPROTO_IPIP) {
590 struct ip ipn;
591
592 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
593 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
594 ahstat.ahs_hdrops,
595 ipcompstat.ipcomps_hdrops);
596 error = EINVAL;
597 goto bad;
598 }
599 /* ipn will now contain the inner IPv4 header */
600 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
601
602 /*
603 * Check that the inner source address is the same as
604 * the proxy address, if available.
605 */
606 if ((saidx->proxy.sa.sa_family == AF_INET &&
607 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
608 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
609 (saidx->proxy.sa.sa_family != AF_INET &&
610 saidx->proxy.sa.sa_family != 0)) {
611
612 DPRINTF(("%s: inner source address %s doesn't "
613 "correspond to expected proxy source %s, "
614 "SA %s/%08lx\n", __func__,
615 inet_ntoa4(ipn.ip_src),
616 ipsec_address(&saidx->proxy),
617 ipsec_address(&saidx->dst),
618 (u_long) ntohl(sav->spi)));
619
620 IPSEC_ISTATsproto, (espstat.esps_pdrops,
621 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
622 error = EACCES;
623 goto bad;
624 }
625 }
626 #endif /* INET */
627
628 /* IPv6-in-IP encapsulation */
629 if (prot == IPPROTO_IPV6) {
630 struct ip6_hdr ip6n;
631
632 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
633 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
634 ahstat.ahs_hdrops,
635 ipcompstat.ipcomps_hdrops);
636 error = EINVAL;
637 goto bad;
638 }
639 /* ip6n will now contain the inner IPv6 header. */
640 m_copydata(m, skip, sizeof(struct ip6_hdr),
641 (caddr_t) &ip6n);
642
643 /*
644 * Check that the inner source address is the same as
645 * the proxy address, if available.
646 */
647 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
648 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
649 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
650 &saidx->proxy.sin6.sin6_addr)) ||
651 (saidx->proxy.sa.sa_family != AF_INET6 &&
652 saidx->proxy.sa.sa_family != 0)) {
653
654 DPRINTF(("%s: inner source address %s doesn't "
655 "correspond to expected proxy source %s, "
656 "SA %s/%08lx\n", __func__,
657 ip6_sprintf(&ip6n.ip6_src),
658 ipsec_address(&saidx->proxy),
659 ipsec_address(&saidx->dst),
660 (u_long) ntohl(sav->spi)));
661
662 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
663 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
664 error = EACCES;
665 goto bad;
666 }
667 }
668 #endif /*XXX*/
669
670 /*
671 * Record what we've done to the packet (under what SA it was
672 * processed). If we've been passed an mtag, it means the packet
673 * was already processed by an ethernet/crypto combo card and
674 * thus has a tag attached with all the right information, but
675 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
676 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
677 */
678 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
679 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
680 sizeof(struct tdb_ident), M_NOWAIT);
681 if (mtag == NULL) {
682 DPRINTF(("%s: failed to get tag\n", __func__));
683 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
684 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
685 error = ENOMEM;
686 goto bad;
687 }
688
689 tdbi = (struct tdb_ident *)(mtag + 1);
690 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
691 tdbi->proto = sproto;
692 tdbi->spi = sav->spi;
693
694 m_tag_prepend(m, mtag);
695 } else {
696 if (mt != NULL)
697 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
698 /* XXX do we need to mark m_flags??? */
699 }
700
701 key_sa_recordxfer(sav, m);
702
703 /* Retrieve new protocol */
704 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
705
706 /*
707 * See the end of ip6_input for this logic.
708 * IPPROTO_IPV[46] case will be processed just like other ones
709 */
710 nest = 0;
711 nxt = nxt8;
712 while (nxt != IPPROTO_DONE) {
713 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
714 ip6stat.ip6s_toomanyhdr++;
715 error = EINVAL;
716 goto bad;
717 }
718
719 /*
720 * Protection against faulty packet - there should be
721 * more sanity checks in header chain processing.
722 */
723 if (m->m_pkthdr.len < skip) {
724 ip6stat.ip6s_tooshort++;
725 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
726 error = EINVAL;
727 goto bad;
728 }
729 /*
730 * Enforce IPsec policy checking if we are seeing last header.
731 * note that we do not visit this with protocols with pcb layer
732 * code - like udp/tcp/raw ip.
733 */
734 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
735 ipsec6_in_reject(m, NULL)) {
736 error = EINVAL;
737 goto bad;
738 }
739 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
740 }
741 return 0;
742 bad:
743 if (m)
744 m_freem(m);
745 return error;
746 }
747
748 void
749 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
750 {
751 if (sa->sa_family != AF_INET6 ||
752 sa->sa_len != sizeof(struct sockaddr_in6))
753 return;
754 if ((unsigned)cmd >= PRC_NCMDS)
755 return;
756
757 /* if the parameter is from icmp6, decode it. */
758 if (d != NULL) {
759 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d;
760 struct mbuf *m = ip6cp->ip6c_m;
761 int off = ip6cp->ip6c_off;
762
763 struct ip6ctlparam ip6cp1;
764
765 /*
766 * Notify the error to all possible sockets via pfctlinput2.
767 * Since the upper layer information (such as protocol type,
768 * source and destination ports) is embedded in the encrypted
769 * data and might have been cut, we can't directly call
770 * an upper layer ctlinput function. However, the pcbnotify
771 * function will consider source and destination addresses
772 * as well as the flow info value, and may be able to find
773 * some PCB that should be notified.
774 * Although pfctlinput2 will call esp6_ctlinput(), there is
775 * no possibility of an infinite loop of function calls,
776 * because we don't pass the inner IPv6 header.
777 */
778 bzero(&ip6cp1, sizeof(ip6cp1));
779 ip6cp1.ip6c_src = ip6cp->ip6c_src;
780 pfctlinput2(cmd, sa, (void *)&ip6cp1);
781
782 /*
783 * Then go to special cases that need ESP header information.
784 * XXX: We assume that when ip6 is non NULL,
785 * M and OFF are valid.
786 */
787
788 if (cmd == PRC_MSGSIZE) {
789 struct secasvar *sav;
790 u_int32_t spi;
791 int valid;
792
793 /* check header length before using m_copydata */
794 if (m->m_pkthdr.len < off + sizeof (struct esp))
795 return;
796 m_copydata(m, off + offsetof(struct esp, esp_spi),
797 sizeof(u_int32_t), (caddr_t) &spi);
798 /*
799 * Check to see if we have a valid SA corresponding to
800 * the address in the ICMP message payload.
801 */
802 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
803 IPPROTO_ESP, spi);
804 valid = (sav != NULL);
805 if (sav)
806 KEY_FREESAV(&sav);
807
808 /* XXX Further validation? */
809
810 /*
811 * Depending on whether the SA is "valid" and
812 * routing table size (mtudisc_{hi,lo}wat), we will:
813 * - recalcurate the new MTU and create the
814 * corresponding routing entry, or
815 * - ignore the MTU change notification.
816 */
817 icmp6_mtudisc_update(ip6cp, valid);
818 }
819 } else {
820 /* we normally notify any pcb here */
821 }
822 }
823 #endif /* INET6 */
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