1 /* $FreeBSD: releng/10.1/sys/netipsec/ipsec_input.c 259385 2013-12-14 04:24:32Z ae $ */
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 #include <net/vnet.h>
63
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #include <netinet/ip.h>
67 #include <netinet/ip_var.h>
68 #include <netinet/in_var.h>
69
70 #include <netinet/ip6.h>
71 #ifdef INET6
72 #include <netinet6/ip6_var.h>
73 #endif
74 #include <netinet/in_pcb.h>
75 #ifdef INET6
76 #include <netinet/icmp6.h>
77 #endif
78
79 #include <netipsec/ipsec.h>
80 #ifdef INET6
81 #include <netipsec/ipsec6.h>
82 #endif
83 #include <netipsec/ah_var.h>
84 #include <netipsec/esp.h>
85 #include <netipsec/esp_var.h>
86 #include <netipsec/ipcomp_var.h>
87
88 #include <netipsec/key.h>
89 #include <netipsec/keydb.h>
90
91 #include <netipsec/xform.h>
92 #include <netinet6/ip6protosw.h>
93
94 #include <machine/in_cksum.h>
95 #include <machine/stdarg.h>
96
97 #ifdef DEV_ENC
98 #include <net/if_enc.h>
99 #endif
100
101
102 #define IPSEC_ISTAT(proto, name) do { \
103 if ((proto) == IPPROTO_ESP) \
104 ESPSTAT_INC(esps_##name); \
105 else if ((proto) == IPPROTO_AH) \
106 AHSTAT_INC(ahs_##name); \
107 else \
108 IPCOMPSTAT_INC(ipcomps_##name); \
109 } while (0)
110
111 #ifdef INET
112 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
113 #endif
114
115 /*
116 * ipsec_common_input gets called when an IPsec-protected packet
117 * is received by IPv4 or IPv6. Its job is to find the right SA
118 * and call the appropriate transform. The transform callback
119 * takes care of further processing (like ingress filtering).
120 */
121 static int
122 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
123 {
124 union sockaddr_union dst_address;
125 struct secasvar *sav;
126 u_int32_t spi;
127 int error;
128 #ifdef INET
129 #ifdef IPSEC_NAT_T
130 struct m_tag *tag;
131 #endif
132 #endif
133
134 IPSEC_ISTAT(sproto, input);
135
136 IPSEC_ASSERT(m != NULL, ("null packet"));
137
138 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
139 sproto == IPPROTO_IPCOMP,
140 ("unexpected security protocol %u", sproto));
141
142 if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
143 (sproto == IPPROTO_AH && !V_ah_enable) ||
144 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
145 m_freem(m);
146 IPSEC_ISTAT(sproto, pdrops);
147 return EOPNOTSUPP;
148 }
149
150 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
151 m_freem(m);
152 IPSEC_ISTAT(sproto, hdrops);
153 DPRINTF(("%s: packet too small\n", __func__));
154 return EINVAL;
155 }
156
157 /* Retrieve the SPI from the relevant IPsec header */
158 if (sproto == IPPROTO_ESP)
159 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
160 else if (sproto == IPPROTO_AH)
161 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
162 (caddr_t) &spi);
163 else if (sproto == IPPROTO_IPCOMP) {
164 u_int16_t cpi;
165 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
166 (caddr_t) &cpi);
167 spi = ntohl(htons(cpi));
168 }
169
170 /*
171 * Find the SA and (indirectly) call the appropriate
172 * kernel crypto routine. The resulting mbuf chain is a valid
173 * IP packet ready to go through input processing.
174 */
175 bzero(&dst_address, sizeof (dst_address));
176 dst_address.sa.sa_family = af;
177 switch (af) {
178 #ifdef INET
179 case AF_INET:
180 dst_address.sin.sin_len = sizeof(struct sockaddr_in);
181 m_copydata(m, offsetof(struct ip, ip_dst),
182 sizeof(struct in_addr),
183 (caddr_t) &dst_address.sin.sin_addr);
184 #ifdef IPSEC_NAT_T
185 /* Find the source port for NAT-T; see udp*_espdecap. */
186 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL);
187 if (tag != NULL)
188 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1];
189 #endif /* IPSEC_NAT_T */
190 break;
191 #endif /* INET */
192 #ifdef INET6
193 case AF_INET6:
194 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
195 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
196 sizeof(struct in6_addr),
197 (caddr_t) &dst_address.sin6.sin6_addr);
198 break;
199 #endif /* INET6 */
200 default:
201 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
202 m_freem(m);
203 IPSEC_ISTAT(sproto, nopf);
204 return EPFNOSUPPORT;
205 }
206
207 /* NB: only pass dst since key_allocsa follows RFC2401 */
208 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
209 if (sav == NULL) {
210 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
211 __func__, ipsec_address(&dst_address),
212 (u_long) ntohl(spi), sproto));
213 IPSEC_ISTAT(sproto, notdb);
214 m_freem(m);
215 return ENOENT;
216 }
217
218 if (sav->tdb_xform == NULL) {
219 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
220 __func__, ipsec_address(&dst_address),
221 (u_long) ntohl(spi), sproto));
222 IPSEC_ISTAT(sproto, noxform);
223 KEY_FREESAV(&sav);
224 m_freem(m);
225 return ENXIO;
226 }
227
228 /*
229 * Call appropriate transform and return -- callback takes care of
230 * everything else.
231 */
232 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
233 KEY_FREESAV(&sav);
234 return error;
235 }
236
237 #ifdef INET
238 /*
239 * Common input handler for IPv4 AH, ESP, and IPCOMP.
240 */
241 int
242 ipsec4_common_input(struct mbuf *m, ...)
243 {
244 va_list ap;
245 int off, nxt;
246
247 va_start(ap, m);
248 off = va_arg(ap, int);
249 nxt = va_arg(ap, int);
250 va_end(ap);
251
252 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
253 AF_INET, nxt);
254 }
255
256 void
257 ah4_input(struct mbuf *m, int off)
258 {
259 ipsec4_common_input(m, off, IPPROTO_AH);
260 }
261 void
262 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
263 {
264 if (sa->sa_family == AF_INET &&
265 sa->sa_len == sizeof(struct sockaddr_in))
266 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
267 }
268
269 void
270 esp4_input(struct mbuf *m, int off)
271 {
272 ipsec4_common_input(m, off, IPPROTO_ESP);
273 }
274 void
275 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
276 {
277 if (sa->sa_family == AF_INET &&
278 sa->sa_len == sizeof(struct sockaddr_in))
279 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
280 }
281
282 void
283 ipcomp4_input(struct mbuf *m, int off)
284 {
285 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
286 }
287
288 /*
289 * IPsec input callback for INET protocols.
290 * This routine is called as the transform callback.
291 * Takes care of filtering and other sanity checks on
292 * the processed packet.
293 */
294 int
295 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
296 int skip, int protoff, struct m_tag *mt)
297 {
298 int prot, af, sproto;
299 struct ip *ip;
300 struct m_tag *mtag;
301 struct tdb_ident *tdbi;
302 struct secasindex *saidx;
303 int error;
304 #ifdef INET6
305 #ifdef notyet
306 char ip6buf[INET6_ADDRSTRLEN];
307 #endif
308 #endif
309
310 IPSEC_ASSERT(m != NULL, ("null mbuf"));
311 IPSEC_ASSERT(sav != NULL, ("null SA"));
312 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
313 saidx = &sav->sah->saidx;
314 af = saidx->dst.sa.sa_family;
315 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
316 sproto = saidx->proto;
317 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
318 sproto == IPPROTO_IPCOMP,
319 ("unexpected security protocol %u", sproto));
320
321 /* Sanity check */
322 if (m == NULL) {
323 DPRINTF(("%s: null mbuf", __func__));
324 IPSEC_ISTAT(sproto, badkcr);
325 KEY_FREESAV(&sav);
326 return EINVAL;
327 }
328
329 if (skip != 0) {
330 /*
331 * Fix IPv4 header
332 * XXXGL: do we need this entire block?
333 */
334 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
335 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
336 __func__, ipsec_address(&sav->sah->saidx.dst),
337 (u_long) ntohl(sav->spi)));
338 IPSEC_ISTAT(sproto, hdrops);
339 error = ENOBUFS;
340 goto bad;
341 }
342
343 ip = mtod(m, struct ip *);
344 ip->ip_len = htons(m->m_pkthdr.len);
345 ip->ip_sum = 0;
346 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
347 } else {
348 ip = mtod(m, struct ip *);
349 }
350 prot = ip->ip_p;
351
352 #ifdef notyet
353 /* IP-in-IP encapsulation */
354 if (prot == IPPROTO_IPIP) {
355 struct ip ipn;
356
357 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
358 IPSEC_ISTAT(sproto, hdrops);
359 error = EINVAL;
360 goto bad;
361 }
362 /* ipn will now contain the inner IPv4 header */
363 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
364 (caddr_t) &ipn);
365
366 /* XXX PROXY address isn't recorded in SAH */
367 /*
368 * Check that the inner source address is the same as
369 * the proxy address, if available.
370 */
371 if ((saidx->proxy.sa.sa_family == AF_INET &&
372 saidx->proxy.sin.sin_addr.s_addr !=
373 INADDR_ANY &&
374 ipn.ip_src.s_addr !=
375 saidx->proxy.sin.sin_addr.s_addr) ||
376 (saidx->proxy.sa.sa_family != AF_INET &&
377 saidx->proxy.sa.sa_family != 0)) {
378
379 DPRINTF(("%s: inner source address %s doesn't "
380 "correspond to expected proxy source %s, "
381 "SA %s/%08lx\n", __func__,
382 inet_ntoa4(ipn.ip_src),
383 ipsp_address(saidx->proxy),
384 ipsp_address(saidx->dst),
385 (u_long) ntohl(sav->spi)));
386
387 IPSEC_ISTAT(sproto, pdrops);
388 error = EACCES;
389 goto bad;
390 }
391 }
392 #ifdef INET6
393 /* IPv6-in-IP encapsulation. */
394 if (prot == IPPROTO_IPV6) {
395 struct ip6_hdr ip6n;
396
397 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
398 IPSEC_ISTAT(sproto, hdrops);
399 error = EINVAL;
400 goto bad;
401 }
402 /* ip6n will now contain the inner IPv6 header. */
403 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
404 (caddr_t) &ip6n);
405
406 /*
407 * Check that the inner source address is the same as
408 * the proxy address, if available.
409 */
410 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
411 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
412 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
413 &saidx->proxy.sin6.sin6_addr)) ||
414 (saidx->proxy.sa.sa_family != AF_INET6 &&
415 saidx->proxy.sa.sa_family != 0)) {
416
417 DPRINTF(("%s: inner source address %s doesn't "
418 "correspond to expected proxy source %s, "
419 "SA %s/%08lx\n", __func__,
420 ip6_sprintf(ip6buf, &ip6n.ip6_src),
421 ipsec_address(&saidx->proxy),
422 ipsec_address(&saidx->dst),
423 (u_long) ntohl(sav->spi)));
424
425 IPSEC_ISTAT(sproto, pdrops);
426 error = EACCES;
427 goto bad;
428 }
429 }
430 #endif /* INET6 */
431 #endif /*XXX*/
432
433 /*
434 * Record what we've done to the packet (under what SA it was
435 * processed). If we've been passed an mtag, it means the packet
436 * was already processed by an ethernet/crypto combo card and
437 * thus has a tag attached with all the right information, but
438 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
439 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
440 */
441 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
442 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
443 sizeof(struct tdb_ident), M_NOWAIT);
444 if (mtag == NULL) {
445 DPRINTF(("%s: failed to get tag\n", __func__));
446 IPSEC_ISTAT(sproto, hdrops);
447 error = ENOMEM;
448 goto bad;
449 }
450
451 tdbi = (struct tdb_ident *)(mtag + 1);
452 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
453 tdbi->proto = sproto;
454 tdbi->spi = sav->spi;
455 /* Cache those two for enc(4) in xform_ipip. */
456 tdbi->alg_auth = sav->alg_auth;
457 tdbi->alg_enc = sav->alg_enc;
458
459 m_tag_prepend(m, mtag);
460 } else if (mt != NULL) {
461 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
462 /* XXX do we need to mark m_flags??? */
463 }
464
465 key_sa_recordxfer(sav, m); /* record data transfer */
466
467 #ifdef DEV_ENC
468 encif->if_ipackets++;
469 encif->if_ibytes += m->m_pkthdr.len;
470
471 /*
472 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
473 * packet later after it has been decapsulated.
474 */
475 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE);
476
477 if (prot != IPPROTO_IPIP)
478 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
479 return (error);
480 #endif
481
482 /*
483 * Re-dispatch via software interrupt.
484 */
485 if ((error = netisr_queue_src(NETISR_IP, (uintptr_t)sav->spi, m))) {
486 IPSEC_ISTAT(sproto, qfull);
487 DPRINTF(("%s: queue full; proto %u packet dropped\n",
488 __func__, sproto));
489 return error;
490 }
491 return 0;
492 bad:
493 m_freem(m);
494 return error;
495 }
496
497 void
498 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
499 {
500 /* XXX nothing just yet */
501 }
502 #endif /* INET */
503
504 #ifdef INET6
505 /* IPv6 AH wrapper. */
506 int
507 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
508 {
509 int l = 0;
510 int protoff;
511 struct ip6_ext ip6e;
512
513 if (*offp < sizeof(struct ip6_hdr)) {
514 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
515 return IPPROTO_DONE;
516 } else if (*offp == sizeof(struct ip6_hdr)) {
517 protoff = offsetof(struct ip6_hdr, ip6_nxt);
518 } else {
519 /* Chase down the header chain... */
520 protoff = sizeof(struct ip6_hdr);
521
522 do {
523 protoff += l;
524 m_copydata(*mp, protoff, sizeof(ip6e),
525 (caddr_t) &ip6e);
526
527 if (ip6e.ip6e_nxt == IPPROTO_AH)
528 l = (ip6e.ip6e_len + 2) << 2;
529 else
530 l = (ip6e.ip6e_len + 1) << 3;
531 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
532 } while (protoff + l < *offp);
533
534 /* Malformed packet check */
535 if (protoff + l != *offp) {
536 DPRINTF(("%s: bad packet header chain, protoff %u, "
537 "l %u, off %u\n", __func__, protoff, l, *offp));
538 IPSEC_ISTAT(proto, hdrops);
539 m_freem(*mp);
540 *mp = NULL;
541 return IPPROTO_DONE;
542 }
543 protoff += offsetof(struct ip6_ext, ip6e_nxt);
544 }
545 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
546 return IPPROTO_DONE;
547 }
548
549 /*
550 * IPsec input callback, called by the transform callback. Takes care of
551 * filtering and other sanity checks on the processed packet.
552 */
553 int
554 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
555 struct m_tag *mt)
556 {
557 int prot, af, sproto;
558 struct ip6_hdr *ip6;
559 struct m_tag *mtag;
560 struct tdb_ident *tdbi;
561 struct secasindex *saidx;
562 int nxt;
563 u_int8_t nxt8;
564 int error, nest;
565 #ifdef notyet
566 char ip6buf[INET6_ADDRSTRLEN];
567 #endif
568
569 IPSEC_ASSERT(m != NULL, ("null mbuf"));
570 IPSEC_ASSERT(sav != NULL, ("null SA"));
571 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
572 saidx = &sav->sah->saidx;
573 af = saidx->dst.sa.sa_family;
574 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
575 sproto = saidx->proto;
576 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
577 sproto == IPPROTO_IPCOMP,
578 ("unexpected security protocol %u", sproto));
579
580 /* Sanity check */
581 if (m == NULL) {
582 DPRINTF(("%s: null mbuf", __func__));
583 IPSEC_ISTAT(sproto, badkcr);
584 error = EINVAL;
585 goto bad;
586 }
587
588 /* Fix IPv6 header */
589 if (m->m_len < sizeof(struct ip6_hdr) &&
590 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
591
592 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
593 __func__, ipsec_address(&sav->sah->saidx.dst),
594 (u_long) ntohl(sav->spi)));
595
596 IPSEC_ISTAT(sproto, hdrops);
597 error = EACCES;
598 goto bad;
599 }
600
601 ip6 = mtod(m, struct ip6_hdr *);
602 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
603
604 /* Save protocol */
605 prot = 0;
606 m_copydata(m, protoff, 1, (unsigned char *) &prot);
607
608 #ifdef notyet
609 #ifdef INET
610 /* IP-in-IP encapsulation */
611 if (prot == IPPROTO_IPIP) {
612 struct ip ipn;
613
614 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
615 IPSEC_ISTAT(sproto, hdrops);
616 error = EINVAL;
617 goto bad;
618 }
619 /* ipn will now contain the inner IPv4 header */
620 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
621
622 /*
623 * Check that the inner source address is the same as
624 * the proxy address, if available.
625 */
626 if ((saidx->proxy.sa.sa_family == AF_INET &&
627 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
628 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
629 (saidx->proxy.sa.sa_family != AF_INET &&
630 saidx->proxy.sa.sa_family != 0)) {
631
632 DPRINTF(("%s: inner source address %s doesn't "
633 "correspond to expected proxy source %s, "
634 "SA %s/%08lx\n", __func__,
635 inet_ntoa4(ipn.ip_src),
636 ipsec_address(&saidx->proxy),
637 ipsec_address(&saidx->dst),
638 (u_long) ntohl(sav->spi)));
639
640 IPSEC_ISTAT(sproto, pdrops);
641 error = EACCES;
642 goto bad;
643 }
644 }
645 #endif /* INET */
646
647 /* IPv6-in-IP encapsulation */
648 if (prot == IPPROTO_IPV6) {
649 struct ip6_hdr ip6n;
650
651 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
652 IPSEC_ISTAT(sproto, hdrops);
653 error = EINVAL;
654 goto bad;
655 }
656 /* ip6n will now contain the inner IPv6 header. */
657 m_copydata(m, skip, sizeof(struct ip6_hdr),
658 (caddr_t) &ip6n);
659
660 /*
661 * Check that the inner source address is the same as
662 * the proxy address, if available.
663 */
664 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
665 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
666 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
667 &saidx->proxy.sin6.sin6_addr)) ||
668 (saidx->proxy.sa.sa_family != AF_INET6 &&
669 saidx->proxy.sa.sa_family != 0)) {
670
671 DPRINTF(("%s: inner source address %s doesn't "
672 "correspond to expected proxy source %s, "
673 "SA %s/%08lx\n", __func__,
674 ip6_sprintf(ip6buf, &ip6n.ip6_src),
675 ipsec_address(&saidx->proxy),
676 ipsec_address(&saidx->dst),
677 (u_long) ntohl(sav->spi)));
678
679 IPSEC_ISTAT(sproto, pdrops);
680 error = EACCES;
681 goto bad;
682 }
683 }
684 #endif /*XXX*/
685
686 /*
687 * Record what we've done to the packet (under what SA it was
688 * processed). If we've been passed an mtag, it means the packet
689 * was already processed by an ethernet/crypto combo card and
690 * thus has a tag attached with all the right information, but
691 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
692 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
693 */
694 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
695 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
696 sizeof(struct tdb_ident), M_NOWAIT);
697 if (mtag == NULL) {
698 DPRINTF(("%s: failed to get tag\n", __func__));
699 IPSEC_ISTAT(sproto, hdrops);
700 error = ENOMEM;
701 goto bad;
702 }
703
704 tdbi = (struct tdb_ident *)(mtag + 1);
705 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
706 tdbi->proto = sproto;
707 tdbi->spi = sav->spi;
708 /* Cache those two for enc(4) in xform_ipip. */
709 tdbi->alg_auth = sav->alg_auth;
710 tdbi->alg_enc = sav->alg_enc;
711
712 m_tag_prepend(m, mtag);
713 } else {
714 if (mt != NULL)
715 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
716 /* XXX do we need to mark m_flags??? */
717 }
718
719 key_sa_recordxfer(sav, m);
720
721 #ifdef DEV_ENC
722 encif->if_ipackets++;
723 encif->if_ibytes += m->m_pkthdr.len;
724
725 /*
726 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
727 * packet later after it has been decapsulated.
728 */
729 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE);
730
731 /* XXX-BZ does not make sense. */
732 if (prot != IPPROTO_IPIP)
733 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
734 return (error);
735 #endif
736
737 /* Retrieve new protocol */
738 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
739
740 /*
741 * See the end of ip6_input for this logic.
742 * IPPROTO_IPV[46] case will be processed just like other ones
743 */
744 nest = 0;
745 nxt = nxt8;
746 while (nxt != IPPROTO_DONE) {
747 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
748 IP6STAT_INC(ip6s_toomanyhdr);
749 error = EINVAL;
750 goto bad;
751 }
752
753 /*
754 * Protection against faulty packet - there should be
755 * more sanity checks in header chain processing.
756 */
757 if (m->m_pkthdr.len < skip) {
758 IP6STAT_INC(ip6s_tooshort);
759 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
760 error = EINVAL;
761 goto bad;
762 }
763 /*
764 * Enforce IPsec policy checking if we are seeing last header.
765 * note that we do not visit this with protocols with pcb layer
766 * code - like udp/tcp/raw ip.
767 */
768 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
769 ipsec6_in_reject(m, NULL)) {
770 error = EINVAL;
771 goto bad;
772 }
773 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
774 }
775 return 0;
776 bad:
777 if (m)
778 m_freem(m);
779 return error;
780 }
781
782 void
783 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
784 {
785 struct ip6ctlparam *ip6cp = NULL;
786 struct mbuf *m = NULL;
787 struct ip6_hdr *ip6;
788 int off;
789
790 if (sa->sa_family != AF_INET6 ||
791 sa->sa_len != sizeof(struct sockaddr_in6))
792 return;
793 if ((unsigned)cmd >= PRC_NCMDS)
794 return;
795
796 /* if the parameter is from icmp6, decode it. */
797 if (d != NULL) {
798 ip6cp = (struct ip6ctlparam *)d;
799 m = ip6cp->ip6c_m;
800 ip6 = ip6cp->ip6c_ip6;
801 off = ip6cp->ip6c_off;
802 } else {
803 m = NULL;
804 ip6 = NULL;
805 off = 0; /* calm gcc */
806 }
807
808 if (ip6 != NULL) {
809
810 struct ip6ctlparam ip6cp1;
811
812 /*
813 * Notify the error to all possible sockets via pfctlinput2.
814 * Since the upper layer information (such as protocol type,
815 * source and destination ports) is embedded in the encrypted
816 * data and might have been cut, we can't directly call
817 * an upper layer ctlinput function. However, the pcbnotify
818 * function will consider source and destination addresses
819 * as well as the flow info value, and may be able to find
820 * some PCB that should be notified.
821 * Although pfctlinput2 will call esp6_ctlinput(), there is
822 * no possibility of an infinite loop of function calls,
823 * because we don't pass the inner IPv6 header.
824 */
825 bzero(&ip6cp1, sizeof(ip6cp1));
826 ip6cp1.ip6c_src = ip6cp->ip6c_src;
827 pfctlinput2(cmd, sa, (void *)&ip6cp1);
828
829 /*
830 * Then go to special cases that need ESP header information.
831 * XXX: We assume that when ip6 is non NULL,
832 * M and OFF are valid.
833 */
834
835 if (cmd == PRC_MSGSIZE) {
836 struct secasvar *sav;
837 u_int32_t spi;
838 int valid;
839
840 /* check header length before using m_copydata */
841 if (m->m_pkthdr.len < off + sizeof (struct esp))
842 return;
843 m_copydata(m, off + offsetof(struct esp, esp_spi),
844 sizeof(u_int32_t), (caddr_t) &spi);
845 /*
846 * Check to see if we have a valid SA corresponding to
847 * the address in the ICMP message payload.
848 */
849 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
850 IPPROTO_ESP, spi);
851 valid = (sav != NULL);
852 if (sav)
853 KEY_FREESAV(&sav);
854
855 /* XXX Further validation? */
856
857 /*
858 * Depending on whether the SA is "valid" and
859 * routing table size (mtudisc_{hi,lo}wat), we will:
860 * - recalcurate the new MTU and create the
861 * corresponding routing entry, or
862 * - ignore the MTU change notification.
863 */
864 icmp6_mtudisc_update(ip6cp, valid);
865 }
866 } else {
867 /* we normally notify any pcb here */
868 }
869 }
870 #endif /* INET6 */
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