1 /* $FreeBSD: src/sys/netipsec/ipsec_input.c,v 1.2.4.2 2003/03/28 20:32:53 sam Exp $ */
2 /* $DragonFly: src/sys/netproto/ipsec/ipsec_input.c,v 1.9 2005/06/17 19:12:23 dillon Exp $ */
3 /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */
5 * The authors of this code are John Ioannidis (ji@tla.org),
6 * Angelos D. Keromytis (kermit@csd.uch.gr) and
7 * Niels Provos (provos@physnet.uni-hamburg.de).
9 * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
12 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
13 * by Angelos D. Keromytis.
15 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
18 * Additional features in 1999 by Angelos D. Keromytis.
20 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
21 * Angelos D. Keromytis and Niels Provos.
22 * Copyright (c) 2001, Angelos D. Keromytis.
24 * Permission to use, copy, and modify this software with or without fee
25 * is hereby granted, provided that this entire notice is included in
26 * all copies of any software which is or includes a copy or
27 * modification of this software.
28 * You may use this code under the GNU public license if you so wish. Please
29 * contribute changes back to the authors under this freer than GPL license
30 * so that we may further the use of strong encryption without limitations to
33 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
34 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
35 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
36 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
41 * IPsec input processing.
45 #include "opt_inet6.h"
46 #include "opt_ipsec.h"
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/malloc.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 #include <sys/in_cksum.h>
60 #include <net/route.h>
61 #include <net/netisr.h>
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>
69 #include <netinet/ip6.h>
71 #include <netinet6/ip6_var.h>
73 #include <netinet/in_pcb.h>
75 #include <netinet/icmp6.h>
78 #include <netproto/ipsec/ipsec.h>
80 #include <netproto/ipsec/ipsec6.h>
82 #include <netproto/ipsec/ah_var.h>
83 #include <netproto/ipsec/esp.h>
84 #include <netproto/ipsec/esp_var.h>
85 #include <netproto/ipsec/ipcomp_var.h>
87 #include <netproto/ipsec/key.h>
88 #include <netproto/ipsec/keydb.h>
90 #include <netproto/ipsec/xform.h>
91 #include <netinet6/ip6protosw.h>
93 #include <machine/stdarg.h>
95 #include <net/net_osdep.h>
97 #define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \
98 (p) == IPPROTO_AH ? (y)++ : (z)++)
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).
107 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
109 union sockaddr_union dst_address;
110 struct secasvar *sav;
114 IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input,
115 ipcompstat.ipcomps_input);
117 KASSERT(m != NULL, ("ipsec_common_input: null packet"));
119 if ((sproto == IPPROTO_ESP && !esp_enable) ||
120 (sproto == IPPROTO_AH && !ah_enable) ||
121 (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) {
123 IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops,
124 ipcompstat.ipcomps_pdrops);
128 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
130 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
131 ipcompstat.ipcomps_hdrops);
132 DPRINTF(("ipsec_common_input: packet too small\n"));
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),
142 else if (sproto == IPPROTO_IPCOMP) {
144 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
146 spi = ntohl(htons(cpi));
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.
154 bzero(&dst_address, sizeof (dst_address));
155 dst_address.sa.sa_family = af;
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);
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);
174 DPRINTF(("ipsec_common_input: unsupported protocol "
177 IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf,
178 ipcompstat.ipcomps_nopf);
184 /* NB: only pass dst since key_allocsa follows RFC2401 */
185 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
187 DPRINTF(("ipsec_common_input: no key association found for"
189 ipsec_address(&dst_address),
190 (u_long) ntohl(spi), sproto));
191 IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb,
192 ipcompstat.ipcomps_notdb);
198 if (sav->tdb_xform == NULL) {
199 DPRINTF(("ipsec_common_input: attempted to use uninitialized"
201 ipsec_address(&dst_address),
202 (u_long) ntohl(spi), sproto));
203 IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform,
204 ipcompstat.ipcomps_noxform);
212 * Call appropriate transform and return -- callback takes care of
215 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
223 * Common input handler for IPv4 AH, ESP, and IPCOMP.
226 ipsec4_common_input(struct mbuf *m, ...)
232 off = __va_arg(ap, int);
233 nxt = __va_arg(ap, int);
236 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
241 * IPsec input callback for INET protocols.
242 * This routine is called as the transform callback.
243 * Takes care of filtering and other sanity checks on
244 * the processed packet.
247 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
248 int skip, int protoff, struct m_tag *mt)
250 int prot, af, sproto;
253 struct tdb_ident *tdbi;
254 struct secasindex *saidx;
257 KASSERT(m != NULL, ("ipsec4_common_input_cb: null mbuf"));
258 KASSERT(sav != NULL, ("ipsec4_common_input_cb: null SA"));
259 KASSERT(sav->sah != NULL, ("ipsec4_common_input_cb: null SAH"));
260 saidx = &sav->sah->saidx;
261 af = saidx->dst.sa.sa_family;
262 KASSERT(af == AF_INET, ("ipsec4_common_input_cb: unexpected af %u",af));
263 sproto = saidx->proto;
264 KASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
265 sproto == IPPROTO_IPCOMP,
266 ("ipsec4_common_input_cb: unexpected security protocol %u",
271 DPRINTF(("ipsec4_common_input_cb: null mbuf"));
272 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
273 ipcompstat.ipcomps_badkcr);
279 /* Fix IPv4 header */
280 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
281 DPRINTF(("ipsec4_common_input_cb: processing failed "
283 ipsec_address(&sav->sah->saidx.dst),
284 (u_long) ntohl(sav->spi)));
285 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
286 ipcompstat.ipcomps_hdrops);
291 ip = mtod(m, struct ip *);
292 ip->ip_len = htons(m->m_pkthdr.len);
293 ip->ip_off = htons(ip->ip_off);
295 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
297 ip = mtod(m, struct ip *);
301 /* IP-in-IP encapsulation */
302 if (prot == IPPROTO_IPIP) {
305 /* ipn will now contain the inner IPv4 header */
306 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
310 /* XXX PROXY address isn't recorded in SAH */
312 * Check that the inner source address is the same as
313 * the proxy address, if available.
315 if ((saidx->proxy.sa.sa_family == AF_INET &&
316 saidx->proxy.sin.sin_addr.s_addr !=
319 saidx->proxy.sin.sin_addr.s_addr) ||
320 (saidx->proxy.sa.sa_family != AF_INET &&
321 saidx->proxy.sa.sa_family != 0)) {
323 DPRINTF(("ipsec4_common_input_cb: inner "
324 "source address %s doesn't correspond to "
325 "expected proxy source %s, SA %s/%08lx\n",
326 inet_ntoa4(ipn.ip_src),
327 ipsp_address(saidx->proxy),
328 ipsp_address(saidx->dst),
329 (u_long) ntohl(sav->spi)));
331 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
333 ipcompstat.ipcomps_pdrops);
340 /* IPv6-in-IP encapsulation. */
341 if (prot == IPPROTO_IPV6) {
344 /* ip6n will now contain the inner IPv6 header. */
345 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
350 * Check that the inner source address is the same as
351 * the proxy address, if available.
353 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
354 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
355 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
356 &saidx->proxy.sin6.sin6_addr)) ||
357 (saidx->proxy.sa.sa_family != AF_INET6 &&
358 saidx->proxy.sa.sa_family != 0)) {
360 DPRINTF(("ipsec4_common_input_cb: inner "
361 "source address %s doesn't correspond to "
362 "expected proxy source %s, SA %s/%08lx\n",
363 ip6_sprintf(&ip6n.ip6_src),
364 ipsec_address(&saidx->proxy),
365 ipsec_address(&saidx->dst),
366 (u_long) ntohl(sav->spi)));
368 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
370 ipcompstat.ipcomps_pdrops);
379 * Record what we've done to the packet (under what SA it was
380 * processed). If we've been passed an mtag, it means the packet
381 * was already processed by an ethernet/crypto combo card and
382 * thus has a tag attached with all the right information, but
383 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
384 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
386 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
387 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
388 sizeof(struct tdb_ident), M_NOWAIT);
390 DPRINTF(("ipsec4_common_input_cb: failed to get tag\n"));
391 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
392 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
397 tdbi = (struct tdb_ident *)m_tag_data(mtag);
398 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
399 tdbi->proto = sproto;
400 tdbi->spi = sav->spi;
402 m_tag_prepend(m, mtag);
404 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
405 /* XXX do we need to mark m_flags??? */
408 key_sa_recordxfer(sav, m); /* record data transfer */
411 * Re-dispatch via software interrupt.
413 if (netisr_queue(NETISR_IP, m)) {
414 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull,
415 ipcompstat.ipcomps_qfull);
417 DPRINTF(("ipsec4_common_input_cb: queue full; "
418 "proto %u packet dropped\n", sproto));
429 /* IPv6 AH wrapper. */
431 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
437 if (*offp < sizeof(struct ip6_hdr)) {
438 DPRINTF(("ipsec6_common_input: bad offset %u\n", *offp));
440 } else if (*offp == sizeof(struct ip6_hdr)) {
441 protoff = offsetof(struct ip6_hdr, ip6_nxt);
443 /* Chase down the header chain... */
444 protoff = sizeof(struct ip6_hdr);
448 m_copydata(*mp, protoff, sizeof(ip6e),
451 if (ip6e.ip6e_nxt == IPPROTO_AH)
452 l = (ip6e.ip6e_len + 2) << 2;
454 l = (ip6e.ip6e_len + 1) << 3;
455 KASSERT(l > 0, ("ah6_input: l went zero or negative"));
456 } while (protoff + l < *offp);
458 /* Malformed packet check */
459 if (protoff + l != *offp) {
460 DPRINTF(("ipsec6_common_input: bad packet header chain, "
461 "protoff %u, l %u, off %u\n", protoff, l, *offp));
462 IPSEC_ISTAT(proto, espstat.esps_hdrops,
464 ipcompstat.ipcomps_hdrops);
469 protoff += offsetof(struct ip6_ext, ip6e_nxt);
471 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
476 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
478 if (sa->sa_family != AF_INET6 ||
479 sa->sa_len != sizeof(struct sockaddr_in6))
481 if ((unsigned)cmd >= PRC_NCMDS)
484 /* if the parameter is from icmp6, decode it. */
486 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d;
487 struct mbuf *m = ip6cp->ip6c_m;
488 int off = ip6cp->ip6c_off;
490 struct ip6ctlparam ip6cp1;
493 * Notify the error to all possible sockets via pfctlinput2.
494 * Since the upper layer information (such as protocol type,
495 * source and destination ports) is embedded in the encrypted
496 * data and might have been cut, we can't directly call
497 * an upper layer ctlinput function. However, the pcbnotify
498 * function will consider source and destination addresses
499 * as well as the flow info value, and may be able to find
500 * some PCB that should be notified.
501 * Although pfctlinput2 will call esp6_ctlinput(), there is
502 * no possibility of an infinite loop of function calls,
503 * because we don't pass the inner IPv6 header.
505 bzero(&ip6cp1, sizeof(ip6cp1));
506 ip6cp1.ip6c_src = ip6cp->ip6c_src;
507 pfctlinput2(cmd, sa, (void *)&ip6cp1);
510 * Then go to special cases that need ESP header information.
511 * XXX: We assume that when ip6 is non NULL,
512 * M and OFF are valid.
515 if (cmd == PRC_MSGSIZE) {
516 struct secasvar *sav;
520 /* check header length before using m_copydata */
521 if (m->m_pkthdr.len < off + sizeof (struct esp))
523 m_copydata(m, off + offsetof(struct esp, esp_spi),
524 sizeof(u_int32_t), (caddr_t) &spi);
526 * Check to see if we have a valid SA corresponding to
527 * the address in the ICMP message payload.
529 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
531 valid = (sav != NULL);
535 /* XXX Further validation? */
538 * Depending on whether the SA is "valid" and
539 * routing table size (mtudisc_{hi,lo}wat), we will:
540 * - recalcurate the new MTU and create the
541 * corresponding routing entry, or
542 * - ignore the MTU change notification.
544 icmp6_mtudisc_update(ip6cp, valid);
547 /* we normally notify any pcb here */
551 extern struct ip6protosw inet6sw[];
552 extern u_char ip6_protox[];
555 * IPsec input callback, called by the transform callback. Takes care of
556 * filtering and other sanity checks on the processed packet.
559 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
562 int prot, af, sproto;
565 struct tdb_ident *tdbi;
566 struct secasindex *saidx;
571 KASSERT(m != NULL, ("ipsec6_common_input_cb: null mbuf"));
572 KASSERT(sav != NULL, ("ipsec6_common_input_cb: null SA"));
573 KASSERT(sav->sah != NULL, ("ipsec6_common_input_cb: null SAH"));
574 saidx = &sav->sah->saidx;
575 af = saidx->dst.sa.sa_family;
576 KASSERT(af == AF_INET6,
577 ("ipsec6_common_input_cb: unexpected af %u", af));
578 sproto = saidx->proto;
579 KASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
580 sproto == IPPROTO_IPCOMP,
581 ("ipsec6_common_input_cb: unexpected security protocol %u",
586 DPRINTF(("ipsec4_common_input_cb: null mbuf"));
587 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
588 ipcompstat.ipcomps_badkcr);
593 /* Fix IPv6 header */
594 if (m->m_len < sizeof(struct ip6_hdr) &&
595 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
597 DPRINTF(("ipsec_common_input_cb: processing failed "
598 "for SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst),
599 (u_long) ntohl(sav->spi)));
601 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
602 ipcompstat.ipcomps_hdrops);
607 ip6 = mtod(m, struct ip6_hdr *);
608 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
611 m_copydata(m, protoff, 1, (unsigned char *) &prot);
614 /* IP-in-IP encapsulation */
615 if (prot == IPPROTO_IPIP) {
618 /* ipn will now contain the inner IPv4 header */
619 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
623 * Check that the inner source address is the same as
624 * the proxy address, if available.
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)) {
632 DPRINTF(("ipsec_common_input_cb: inner "
633 "source address %s doesn't correspond to "
634 "expected proxy source %s, SA %s/%08lx\n",
635 inet_ntoa4(ipn.ip_src),
636 ipsec_address(&saidx->proxy),
637 ipsec_address(&saidx->dst),
638 (u_long) ntohl(sav->spi)));
640 IPSEC_ISTATsproto, (espstat.esps_pdrops,
641 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
649 /* IPv6-in-IP encapsulation */
650 if (prot == IPPROTO_IPV6) {
653 /* ip6n will now contain the inner IPv6 header. */
654 m_copydata(m, skip, sizeof(struct ip6_hdr),
659 * Check that the inner source address is the same as
660 * the proxy address, if available.
662 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
663 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
664 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
665 &saidx->proxy.sin6.sin6_addr)) ||
666 (saidx->proxy.sa.sa_family != AF_INET6 &&
667 saidx->proxy.sa.sa_family != 0)) {
669 DPRINTF(("ipsec_common_input_cb: inner "
670 "source address %s doesn't correspond to "
671 "expected proxy source %s, SA %s/%08lx\n",
672 ip6_sprintf(&ip6n.ip6_src),
673 ipsec_address(&saidx->proxy),
674 ipsec_address(&saidx->dst),
675 (u_long) ntohl(sav->spi)));
677 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
678 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
686 * Record what we've done to the packet (under what SA it was
687 * processed). If we've been passed an mtag, it means the packet
688 * was already processed by an ethernet/crypto combo card and
689 * thus has a tag attached with all the right information, but
690 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
691 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
693 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
694 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
695 sizeof(struct tdb_ident), M_NOWAIT);
697 DPRINTF(("ipsec_common_input_cb: failed to "
699 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
700 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
705 tdbi = (struct tdb_ident *)m_tag_data(mtag);
706 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
707 tdbi->proto = sproto;
708 tdbi->spi = sav->spi;
710 m_tag_prepend(m, mtag);
712 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
713 /* XXX do we need to mark m_flags??? */
716 key_sa_recordxfer(sav, m);
718 /* Retrieve new protocol */
719 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
722 * See the end of ip6_input for this logic.
723 * IPPROTO_IPV[46] case will be processed just like other ones
727 while (nxt != IPPROTO_DONE) {
728 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
729 ip6stat.ip6s_toomanyhdr++;
735 * Protection against faulty packet - there should be
736 * more sanity checks in header chain processing.
738 if (m->m_pkthdr.len < skip) {
739 ip6stat.ip6s_tooshort++;
740 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
745 * Enforce IPsec policy checking if we are seeing last header.
746 * note that we do not visit this with protocols with pcb layer
747 * code - like udp/tcp/raw ip.
749 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
750 ipsec6_in_reject(m, NULL)) {
754 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);