1 /* $FreeBSD$ */
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/pfil.h>
60 #include <net/route.h>
61 #include <net/netisr.h>
62
63 #include <netinet/in.h>
64 #include <netinet/in_systm.h>
65 #include <netinet/ip.h>
66 #include <netinet/ip_var.h>
67 #include <netinet/in_var.h>
68
69 #include <netinet/ip6.h>
70 #ifdef INET6
71 #include <netinet6/ip6_var.h>
72 #endif
73 #include <netinet/in_pcb.h>
74 #ifdef INET6
75 #include <netinet/icmp6.h>
76 #endif
77
78 #include <netipsec/ipsec.h>
79 #ifdef INET6
80 #include <netipsec/ipsec6.h>
81 #endif
82 #include <netipsec/ah_var.h>
83 #include <netipsec/esp.h>
84 #include <netipsec/esp_var.h>
85 #include <netipsec/ipcomp_var.h>
86
87 #include <netipsec/key.h>
88 #include <netipsec/keydb.h>
89
90 #include <netipsec/xform.h>
91 #include <netinet6/ip6protosw.h>
92
93 #include <machine/in_cksum.h>
94 #include <machine/stdarg.h>
95
96 #define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \
97 (p) == IPPROTO_AH ? (y)++ : (z)++)
98
99 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
100
101 /*
102 * ipsec_common_input gets called when an IPsec-protected packet
103 * is received by IPv4 or IPv6. It's job is to find the right SA
104 * and call the appropriate transform. The transform callback
105 * takes care of further processing (like ingress filtering).
106 */
107 static int
108 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
109 {
110 union sockaddr_union dst_address;
111 struct secasvar *sav;
112 u_int32_t spi;
113 int error;
114
115 IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input,
116 ipcompstat.ipcomps_input);
117
118 IPSEC_ASSERT(m != NULL, ("null packet"));
119
120 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
121 sproto == IPPROTO_IPCOMP,
122 ("unexpected security protocol %u", sproto));
123
124 if ((sproto == IPPROTO_ESP && !esp_enable) ||
125 (sproto == IPPROTO_AH && !ah_enable) ||
126 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) {
127 m_freem(m);
128 IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops,
129 ipcompstat.ipcomps_pdrops);
130 return EOPNOTSUPP;
131 }
132
133 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
134 m_freem(m);
135 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
136 ipcompstat.ipcomps_hdrops);
137 DPRINTF(("%s: packet too small\n", __func__));
138 return EINVAL;
139 }
140
141 /* Retrieve the SPI from the relevant IPsec header */
142 if (sproto == IPPROTO_ESP)
143 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
144 else if (sproto == IPPROTO_AH)
145 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
146 (caddr_t) &spi);
147 else if (sproto == IPPROTO_IPCOMP) {
148 u_int16_t cpi;
149 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
150 (caddr_t) &cpi);
151 spi = ntohl(htons(cpi));
152 }
153
154 /*
155 * Find the SA and (indirectly) call the appropriate
156 * kernel crypto routine. The resulting mbuf chain is a valid
157 * IP packet ready to go through input processing.
158 */
159 bzero(&dst_address, sizeof (dst_address));
160 dst_address.sa.sa_family = af;
161 switch (af) {
162 #ifdef INET
163 case AF_INET:
164 dst_address.sin.sin_len = sizeof(struct sockaddr_in);
165 m_copydata(m, offsetof(struct ip, ip_dst),
166 sizeof(struct in_addr),
167 (caddr_t) &dst_address.sin.sin_addr);
168 break;
169 #endif /* INET */
170 #ifdef INET6
171 case AF_INET6:
172 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
173 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
174 sizeof(struct in6_addr),
175 (caddr_t) &dst_address.sin6.sin6_addr);
176 break;
177 #endif /* INET6 */
178 default:
179 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
180 m_freem(m);
181 IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf,
182 ipcompstat.ipcomps_nopf);
183 return EPFNOSUPPORT;
184 }
185
186 /* NB: only pass dst since key_allocsa follows RFC2401 */
187 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
188 if (sav == NULL) {
189 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
190 __func__, ipsec_address(&dst_address),
191 (u_long) ntohl(spi), sproto));
192 IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb,
193 ipcompstat.ipcomps_notdb);
194 m_freem(m);
195 return ENOENT;
196 }
197
198 if (sav->tdb_xform == NULL) {
199 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
200 __func__, ipsec_address(&dst_address),
201 (u_long) ntohl(spi), sproto));
202 IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform,
203 ipcompstat.ipcomps_noxform);
204 KEY_FREESAV(&sav);
205 m_freem(m);
206 return ENXIO;
207 }
208
209 /*
210 * Call appropriate transform and return -- callback takes care of
211 * everything else.
212 */
213 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
214 KEY_FREESAV(&sav);
215 return error;
216 }
217
218 #ifdef INET
219 /*
220 * Common input handler for IPv4 AH, ESP, and IPCOMP.
221 */
222 int
223 ipsec4_common_input(struct mbuf *m, ...)
224 {
225 va_list ap;
226 int off, nxt;
227
228 va_start(ap, m);
229 off = va_arg(ap, int);
230 nxt = va_arg(ap, int);
231 va_end(ap);
232
233 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
234 AF_INET, nxt);
235 }
236
237 void
238 ah4_input(struct mbuf *m, int off)
239 {
240 ipsec4_common_input(m, off, IPPROTO_AH);
241 }
242 void
243 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
244 {
245 if (sa->sa_family == AF_INET &&
246 sa->sa_len == sizeof(struct sockaddr_in))
247 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
248 }
249
250 void
251 esp4_input(struct mbuf *m, int off)
252 {
253 ipsec4_common_input(m, off, IPPROTO_ESP);
254 }
255 void
256 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
257 {
258 if (sa->sa_family == AF_INET &&
259 sa->sa_len == sizeof(struct sockaddr_in))
260 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
261 }
262
263 void
264 ipcomp4_input(struct mbuf *m, int off)
265 {
266 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
267 }
268
269 /*
270 * IPsec input callback for INET protocols.
271 * This routine is called as the transform callback.
272 * Takes care of filtering and other sanity checks on
273 * the processed packet.
274 */
275 int
276 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
277 int skip, int protoff, struct m_tag *mt)
278 {
279 int prot, af, sproto;
280 struct ip *ip;
281 struct m_tag *mtag;
282 struct tdb_ident *tdbi;
283 struct secasindex *saidx;
284 int error;
285 #ifdef INET6
286 #ifdef notyet
287 char ip6buf[INET6_ADDRSTRLEN];
288 #endif
289 #endif
290
291 IPSEC_SPLASSERT_SOFTNET(__func__);
292
293 IPSEC_ASSERT(m != NULL, ("null mbuf"));
294 IPSEC_ASSERT(sav != NULL, ("null SA"));
295 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
296 saidx = &sav->sah->saidx;
297 af = saidx->dst.sa.sa_family;
298 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
299 sproto = saidx->proto;
300 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
301 sproto == IPPROTO_IPCOMP,
302 ("unexpected security protocol %u", sproto));
303
304 /* Sanity check */
305 if (m == NULL) {
306 DPRINTF(("%s: null mbuf", __func__));
307 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
308 ipcompstat.ipcomps_badkcr);
309 KEY_FREESAV(&sav);
310 return EINVAL;
311 }
312
313 if (skip != 0) {
314 /* Fix IPv4 header */
315 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
316 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
317 __func__, ipsec_address(&sav->sah->saidx.dst),
318 (u_long) ntohl(sav->spi)));
319 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
320 ipcompstat.ipcomps_hdrops);
321 error = ENOBUFS;
322 goto bad;
323 }
324
325 ip = mtod(m, struct ip *);
326 ip->ip_len = htons(m->m_pkthdr.len);
327 ip->ip_off = htons(ip->ip_off);
328 ip->ip_sum = 0;
329 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
330 } else {
331 ip = mtod(m, struct ip *);
332 }
333 prot = ip->ip_p;
334
335 #ifdef notyet
336 /* IP-in-IP encapsulation */
337 if (prot == IPPROTO_IPIP) {
338 struct ip ipn;
339
340 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
341 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
342 ahstat.ahs_hdrops,
343 ipcompstat.ipcomps_hdrops);
344 error = EINVAL;
345 goto bad;
346 }
347 /* ipn will now contain the inner IPv4 header */
348 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
349 (caddr_t) &ipn);
350
351 /* XXX PROXY address isn't recorded in SAH */
352 /*
353 * Check that the inner source address is the same as
354 * the proxy address, if available.
355 */
356 if ((saidx->proxy.sa.sa_family == AF_INET &&
357 saidx->proxy.sin.sin_addr.s_addr !=
358 INADDR_ANY &&
359 ipn.ip_src.s_addr !=
360 saidx->proxy.sin.sin_addr.s_addr) ||
361 (saidx->proxy.sa.sa_family != AF_INET &&
362 saidx->proxy.sa.sa_family != 0)) {
363
364 DPRINTF(("%s: inner source address %s doesn't "
365 "correspond to expected proxy source %s, "
366 "SA %s/%08lx\n", __func__,
367 inet_ntoa4(ipn.ip_src),
368 ipsp_address(saidx->proxy),
369 ipsp_address(saidx->dst),
370 (u_long) ntohl(sav->spi)));
371
372 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
373 ahstat.ahs_pdrops,
374 ipcompstat.ipcomps_pdrops);
375 error = EACCES;
376 goto bad;
377 }
378 }
379 #ifdef INET6
380 /* IPv6-in-IP encapsulation. */
381 if (prot == IPPROTO_IPV6) {
382 struct ip6_hdr ip6n;
383
384 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
385 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
386 ahstat.ahs_hdrops,
387 ipcompstat.ipcomps_hdrops);
388 error = EINVAL;
389 goto bad;
390 }
391 /* ip6n will now contain the inner IPv6 header. */
392 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
393 (caddr_t) &ip6n);
394
395 /*
396 * Check that the inner source address is the same as
397 * the proxy address, if available.
398 */
399 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
400 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
401 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
402 &saidx->proxy.sin6.sin6_addr)) ||
403 (saidx->proxy.sa.sa_family != AF_INET6 &&
404 saidx->proxy.sa.sa_family != 0)) {
405
406 DPRINTF(("%s: inner source address %s doesn't "
407 "correspond to expected proxy source %s, "
408 "SA %s/%08lx\n", __func__,
409 ip6_sprintf(ip6buf, &ip6n.ip6_src),
410 ipsec_address(&saidx->proxy),
411 ipsec_address(&saidx->dst),
412 (u_long) ntohl(sav->spi)));
413
414 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
415 ahstat.ahs_pdrops,
416 ipcompstat.ipcomps_pdrops);
417 error = EACCES;
418 goto bad;
419 }
420 }
421 #endif /* INET6 */
422 #endif /*XXX*/
423
424 /*
425 * Record what we've done to the packet (under what SA it was
426 * processed). If we've been passed an mtag, it means the packet
427 * was already processed by an ethernet/crypto combo card and
428 * thus has a tag attached with all the right information, but
429 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
430 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
431 */
432 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
433 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
434 sizeof(struct tdb_ident), M_NOWAIT);
435 if (mtag == NULL) {
436 DPRINTF(("%s: failed to get tag\n", __func__));
437 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
438 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
439 error = ENOMEM;
440 goto bad;
441 }
442
443 tdbi = (struct tdb_ident *)(mtag + 1);
444 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
445 tdbi->proto = sproto;
446 tdbi->spi = sav->spi;
447
448 m_tag_prepend(m, mtag);
449 } else if (mt != NULL) {
450 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
451 /* XXX do we need to mark m_flags??? */
452 }
453
454 key_sa_recordxfer(sav, m); /* record data transfer */
455
456 #ifdef DEV_ENC
457 /*
458 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
459 * packet later after it has been decapsulated.
460 */
461 ipsec_bpf(m, sav, AF_INET);
462
463 if (prot != IPPROTO_IPIP)
464 if ((error = ipsec_filter(&m, PFIL_IN)) != 0)
465 return (error);
466 #endif
467
468 /*
469 * Re-dispatch via software interrupt.
470 */
471 if ((error = netisr_queue(NETISR_IP, m))) {
472 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull,
473 ipcompstat.ipcomps_qfull);
474
475 DPRINTF(("%s: queue full; proto %u packet dropped\n",
476 __func__, sproto));
477 return error;
478 }
479 return 0;
480 bad:
481 m_freem(m);
482 return error;
483 }
484
485 void
486 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
487 {
488 /* XXX nothing just yet */
489 }
490 #endif /* INET */
491
492 #ifdef INET6
493 /* IPv6 AH wrapper. */
494 int
495 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
496 {
497 int l = 0;
498 int protoff;
499 struct ip6_ext ip6e;
500
501 if (*offp < sizeof(struct ip6_hdr)) {
502 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
503 return IPPROTO_DONE;
504 } else if (*offp == sizeof(struct ip6_hdr)) {
505 protoff = offsetof(struct ip6_hdr, ip6_nxt);
506 } else {
507 /* Chase down the header chain... */
508 protoff = sizeof(struct ip6_hdr);
509
510 do {
511 protoff += l;
512 m_copydata(*mp, protoff, sizeof(ip6e),
513 (caddr_t) &ip6e);
514
515 if (ip6e.ip6e_nxt == IPPROTO_AH)
516 l = (ip6e.ip6e_len + 2) << 2;
517 else
518 l = (ip6e.ip6e_len + 1) << 3;
519 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
520 } while (protoff + l < *offp);
521
522 /* Malformed packet check */
523 if (protoff + l != *offp) {
524 DPRINTF(("%s: bad packet header chain, protoff %u, "
525 "l %u, off %u\n", __func__, protoff, l, *offp));
526 IPSEC_ISTAT(proto, espstat.esps_hdrops,
527 ahstat.ahs_hdrops,
528 ipcompstat.ipcomps_hdrops);
529 m_freem(*mp);
530 *mp = NULL;
531 return IPPROTO_DONE;
532 }
533 protoff += offsetof(struct ip6_ext, ip6e_nxt);
534 }
535 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
536 return IPPROTO_DONE;
537 }
538
539 /*
540 * IPsec input callback, called by the transform callback. Takes care of
541 * filtering and other sanity checks on the processed packet.
542 */
543 int
544 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
545 struct m_tag *mt)
546 {
547 int prot, af, sproto;
548 struct ip6_hdr *ip6;
549 struct m_tag *mtag;
550 struct tdb_ident *tdbi;
551 struct secasindex *saidx;
552 int nxt;
553 u_int8_t nxt8;
554 int error, nest;
555 #ifdef notyet
556 char ip6buf[INET6_ADDRSTRLEN];
557 #endif
558
559 IPSEC_ASSERT(m != NULL, ("null mbuf"));
560 IPSEC_ASSERT(sav != NULL, ("null SA"));
561 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
562 saidx = &sav->sah->saidx;
563 af = saidx->dst.sa.sa_family;
564 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
565 sproto = saidx->proto;
566 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
567 sproto == IPPROTO_IPCOMP,
568 ("unexpected security protocol %u", sproto));
569
570 /* Sanity check */
571 if (m == NULL) {
572 DPRINTF(("%s: null mbuf", __func__));
573 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
574 ipcompstat.ipcomps_badkcr);
575 error = EINVAL;
576 goto bad;
577 }
578
579 /* Fix IPv6 header */
580 if (m->m_len < sizeof(struct ip6_hdr) &&
581 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
582
583 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
584 __func__, ipsec_address(&sav->sah->saidx.dst),
585 (u_long) ntohl(sav->spi)));
586
587 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
588 ipcompstat.ipcomps_hdrops);
589 error = EACCES;
590 goto bad;
591 }
592
593 ip6 = mtod(m, struct ip6_hdr *);
594 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
595
596 /* Save protocol */
597 m_copydata(m, protoff, 1, (unsigned char *) &prot);
598
599 #ifdef notyet
600 #ifdef INET
601 /* IP-in-IP encapsulation */
602 if (prot == IPPROTO_IPIP) {
603 struct ip ipn;
604
605 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
606 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
607 ahstat.ahs_hdrops,
608 ipcompstat.ipcomps_hdrops);
609 error = EINVAL;
610 goto bad;
611 }
612 /* ipn will now contain the inner IPv4 header */
613 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
614
615 /*
616 * Check that the inner source address is the same as
617 * the proxy address, if available.
618 */
619 if ((saidx->proxy.sa.sa_family == AF_INET &&
620 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
621 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
622 (saidx->proxy.sa.sa_family != AF_INET &&
623 saidx->proxy.sa.sa_family != 0)) {
624
625 DPRINTF(("%s: inner source address %s doesn't "
626 "correspond to expected proxy source %s, "
627 "SA %s/%08lx\n", __func__,
628 inet_ntoa4(ipn.ip_src),
629 ipsec_address(&saidx->proxy),
630 ipsec_address(&saidx->dst),
631 (u_long) ntohl(sav->spi)));
632
633 IPSEC_ISTATsproto, (espstat.esps_pdrops,
634 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
635 error = EACCES;
636 goto bad;
637 }
638 }
639 #endif /* INET */
640
641 /* IPv6-in-IP encapsulation */
642 if (prot == IPPROTO_IPV6) {
643 struct ip6_hdr ip6n;
644
645 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
646 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
647 ahstat.ahs_hdrops,
648 ipcompstat.ipcomps_hdrops);
649 error = EINVAL;
650 goto bad;
651 }
652 /* ip6n will now contain the inner IPv6 header. */
653 m_copydata(m, skip, sizeof(struct ip6_hdr),
654 (caddr_t) &ip6n);
655
656 /*
657 * Check that the inner source address is the same as
658 * the proxy address, if available.
659 */
660 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
661 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
662 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
663 &saidx->proxy.sin6.sin6_addr)) ||
664 (saidx->proxy.sa.sa_family != AF_INET6 &&
665 saidx->proxy.sa.sa_family != 0)) {
666
667 DPRINTF(("%s: inner source address %s doesn't "
668 "correspond to expected proxy source %s, "
669 "SA %s/%08lx\n", __func__,
670 ip6_sprintf(ip6buf, &ip6n.ip6_src),
671 ipsec_address(&saidx->proxy),
672 ipsec_address(&saidx->dst),
673 (u_long) ntohl(sav->spi)));
674
675 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
676 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
677 error = EACCES;
678 goto bad;
679 }
680 }
681 #endif /*XXX*/
682
683 /*
684 * Record what we've done to the packet (under what SA it was
685 * processed). If we've been passed an mtag, it means the packet
686 * was already processed by an ethernet/crypto combo card and
687 * thus has a tag attached with all the right information, but
688 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
689 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
690 */
691 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
692 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
693 sizeof(struct tdb_ident), M_NOWAIT);
694 if (mtag == NULL) {
695 DPRINTF(("%s: failed to get tag\n", __func__));
696 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
697 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
698 error = ENOMEM;
699 goto bad;
700 }
701
702 tdbi = (struct tdb_ident *)(mtag + 1);
703 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
704 tdbi->proto = sproto;
705 tdbi->spi = sav->spi;
706
707 m_tag_prepend(m, mtag);
708 } else {
709 if (mt != NULL)
710 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
711 /* XXX do we need to mark m_flags??? */
712 }
713
714 key_sa_recordxfer(sav, m);
715
716 /* Retrieve new protocol */
717 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
718
719 /*
720 * See the end of ip6_input for this logic.
721 * IPPROTO_IPV[46] case will be processed just like other ones
722 */
723 nest = 0;
724 nxt = nxt8;
725 while (nxt != IPPROTO_DONE) {
726 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
727 ip6stat.ip6s_toomanyhdr++;
728 error = EINVAL;
729 goto bad;
730 }
731
732 /*
733 * Protection against faulty packet - there should be
734 * more sanity checks in header chain processing.
735 */
736 if (m->m_pkthdr.len < skip) {
737 ip6stat.ip6s_tooshort++;
738 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
739 error = EINVAL;
740 goto bad;
741 }
742 /*
743 * Enforce IPsec policy checking if we are seeing last header.
744 * note that we do not visit this with protocols with pcb layer
745 * code - like udp/tcp/raw ip.
746 */
747 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
748 ipsec6_in_reject(m, NULL)) {
749 error = EINVAL;
750 goto bad;
751 }
752 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
753 }
754 return 0;
755 bad:
756 if (m)
757 m_freem(m);
758 return error;
759 }
760
761 void
762 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
763 {
764 struct ip6ctlparam *ip6cp = NULL;
765 struct mbuf *m = NULL;
766 struct ip6_hdr *ip6;
767 int off;
768
769 if (sa->sa_family != AF_INET6 ||
770 sa->sa_len != sizeof(struct sockaddr_in6))
771 return;
772 if ((unsigned)cmd >= PRC_NCMDS)
773 return;
774
775 /* if the parameter is from icmp6, decode it. */
776 if (d != NULL) {
777 ip6cp = (struct ip6ctlparam *)d;
778 m = ip6cp->ip6c_m;
779 ip6 = ip6cp->ip6c_ip6;
780 off = ip6cp->ip6c_off;
781 } else {
782 m = NULL;
783 ip6 = NULL;
784 off = 0; /* calm gcc */
785 }
786
787 if (ip6 != NULL) {
788
789 struct ip6ctlparam ip6cp1;
790
791 /*
792 * Notify the error to all possible sockets via pfctlinput2.
793 * Since the upper layer information (such as protocol type,
794 * source and destination ports) is embedded in the encrypted
795 * data and might have been cut, we can't directly call
796 * an upper layer ctlinput function. However, the pcbnotify
797 * function will consider source and destination addresses
798 * as well as the flow info value, and may be able to find
799 * some PCB that should be notified.
800 * Although pfctlinput2 will call esp6_ctlinput(), there is
801 * no possibility of an infinite loop of function calls,
802 * because we don't pass the inner IPv6 header.
803 */
804 bzero(&ip6cp1, sizeof(ip6cp1));
805 ip6cp1.ip6c_src = ip6cp->ip6c_src;
806 pfctlinput2(cmd, sa, (void *)&ip6cp1);
807
808 /*
809 * Then go to special cases that need ESP header information.
810 * XXX: We assume that when ip6 is non NULL,
811 * M and OFF are valid.
812 */
813
814 if (cmd == PRC_MSGSIZE) {
815 struct secasvar *sav;
816 u_int32_t spi;
817 int valid;
818
819 /* check header length before using m_copydata */
820 if (m->m_pkthdr.len < off + sizeof (struct esp))
821 return;
822 m_copydata(m, off + offsetof(struct esp, esp_spi),
823 sizeof(u_int32_t), (caddr_t) &spi);
824 /*
825 * Check to see if we have a valid SA corresponding to
826 * the address in the ICMP message payload.
827 */
828 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
829 IPPROTO_ESP, spi);
830 valid = (sav != NULL);
831 if (sav)
832 KEY_FREESAV(&sav);
833
834 /* XXX Further validation? */
835
836 /*
837 * Depending on whether the SA is "valid" and
838 * routing table size (mtudisc_{hi,lo}wat), we will:
839 * - recalcurate the new MTU and create the
840 * corresponding routing entry, or
841 * - ignore the MTU change notification.
842 */
843 icmp6_mtudisc_update(ip6cp, valid);
844 }
845 } else {
846 /* we normally notify any pcb here */
847 }
848 }
849 #endif /* INET6 */
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