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 1.3 2003/08/07 21:17:37 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>
59 #include <net/route.h>
60 #include <net/netisr.h>
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>
68 #include <netinet/ip6.h>
70 #include <netinet6/ip6_var.h>
72 #include <netinet/in_pcb.h>
74 #include <netinet/icmp6.h>
84 #include "ipcomp_var.h"
90 #include <netinet6/ip6protosw.h>
92 #include <machine/in_cksum.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 SPLASSERT(net, "ipsec4_common_input_cb");
259 KASSERT(m != NULL, ("ipsec4_common_input_cb: null mbuf"));
260 KASSERT(sav != NULL, ("ipsec4_common_input_cb: null SA"));
261 KASSERT(sav->sah != NULL, ("ipsec4_common_input_cb: null SAH"));
262 saidx = &sav->sah->saidx;
263 af = saidx->dst.sa.sa_family;
264 KASSERT(af == AF_INET, ("ipsec4_common_input_cb: unexpected af %u",af));
265 sproto = saidx->proto;
266 KASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
267 sproto == IPPROTO_IPCOMP,
268 ("ipsec4_common_input_cb: unexpected security protocol %u",
273 DPRINTF(("ipsec4_common_input_cb: null mbuf"));
274 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
275 ipcompstat.ipcomps_badkcr);
281 /* Fix IPv4 header */
282 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
283 DPRINTF(("ipsec4_common_input_cb: processing failed "
285 ipsec_address(&sav->sah->saidx.dst),
286 (u_long) ntohl(sav->spi)));
287 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
288 ipcompstat.ipcomps_hdrops);
293 ip = mtod(m, struct ip *);
294 ip->ip_len = htons(m->m_pkthdr.len);
295 ip->ip_off = htons(ip->ip_off);
297 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
299 ip = mtod(m, struct ip *);
303 /* IP-in-IP encapsulation */
304 if (prot == IPPROTO_IPIP) {
307 /* ipn will now contain the inner IPv4 header */
308 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
312 /* XXX PROXY address isn't recorded in SAH */
314 * Check that the inner source address is the same as
315 * the proxy address, if available.
317 if ((saidx->proxy.sa.sa_family == AF_INET &&
318 saidx->proxy.sin.sin_addr.s_addr !=
321 saidx->proxy.sin.sin_addr.s_addr) ||
322 (saidx->proxy.sa.sa_family != AF_INET &&
323 saidx->proxy.sa.sa_family != 0)) {
325 DPRINTF(("ipsec4_common_input_cb: inner "
326 "source address %s doesn't correspond to "
327 "expected proxy source %s, SA %s/%08lx\n",
328 inet_ntoa4(ipn.ip_src),
329 ipsp_address(saidx->proxy),
330 ipsp_address(saidx->dst),
331 (u_long) ntohl(sav->spi)));
333 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
335 ipcompstat.ipcomps_pdrops);
342 /* IPv6-in-IP encapsulation. */
343 if (prot == IPPROTO_IPV6) {
346 /* ip6n will now contain the inner IPv6 header. */
347 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
352 * Check that the inner source address is the same as
353 * the proxy address, if available.
355 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
356 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
357 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
358 &saidx->proxy.sin6.sin6_addr)) ||
359 (saidx->proxy.sa.sa_family != AF_INET6 &&
360 saidx->proxy.sa.sa_family != 0)) {
362 DPRINTF(("ipsec4_common_input_cb: inner "
363 "source address %s doesn't correspond to "
364 "expected proxy source %s, SA %s/%08lx\n",
365 ip6_sprintf(&ip6n.ip6_src),
366 ipsec_address(&saidx->proxy),
367 ipsec_address(&saidx->dst),
368 (u_long) ntohl(sav->spi)));
370 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
372 ipcompstat.ipcomps_pdrops);
381 * Record what we've done to the packet (under what SA it was
382 * processed). If we've been passed an mtag, it means the packet
383 * was already processed by an ethernet/crypto combo card and
384 * thus has a tag attached with all the right information, but
385 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
386 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
388 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
389 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
390 sizeof(struct tdb_ident), M_NOWAIT);
392 DPRINTF(("ipsec4_common_input_cb: failed to get tag\n"));
393 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
394 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
399 tdbi = (struct tdb_ident *)(mtag + 1);
400 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
401 tdbi->proto = sproto;
402 tdbi->spi = sav->spi;
404 m_tag_prepend(m, mtag);
406 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
407 /* XXX do we need to mark m_flags??? */
410 key_sa_recordxfer(sav, m); /* record data transfer */
413 * Re-dispatch via software interrupt.
415 if (!IF_HANDOFF(&ipintrq, m, NULL)) {
416 IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull,
417 ipcompstat.ipcomps_qfull);
419 DPRINTF(("ipsec4_common_input_cb: queue full; "
420 "proto %u packet dropped\n", sproto));
423 schednetisr(NETISR_IP);
432 /* IPv6 AH wrapper. */
434 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
440 if (*offp < sizeof(struct ip6_hdr)) {
441 DPRINTF(("ipsec6_common_input: bad offset %u\n", *offp));
443 } else if (*offp == sizeof(struct ip6_hdr)) {
444 protoff = offsetof(struct ip6_hdr, ip6_nxt);
446 /* Chase down the header chain... */
447 protoff = sizeof(struct ip6_hdr);
451 m_copydata(*mp, protoff, sizeof(ip6e),
454 if (ip6e.ip6e_nxt == IPPROTO_AH)
455 l = (ip6e.ip6e_len + 2) << 2;
457 l = (ip6e.ip6e_len + 1) << 3;
458 KASSERT(l > 0, ("ah6_input: l went zero or negative"));
459 } while (protoff + l < *offp);
461 /* Malformed packet check */
462 if (protoff + l != *offp) {
463 DPRINTF(("ipsec6_common_input: bad packet header chain, "
464 "protoff %u, l %u, off %u\n", protoff, l, *offp));
465 IPSEC_ISTAT(proto, espstat.esps_hdrops,
467 ipcompstat.ipcomps_hdrops);
472 protoff += offsetof(struct ip6_ext, ip6e_nxt);
474 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
479 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
481 if (sa->sa_family != AF_INET6 ||
482 sa->sa_len != sizeof(struct sockaddr_in6))
484 if ((unsigned)cmd >= PRC_NCMDS)
487 /* if the parameter is from icmp6, decode it. */
489 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d;
490 struct mbuf *m = ip6cp->ip6c_m;
491 int off = ip6cp->ip6c_off;
493 struct ip6ctlparam ip6cp1;
496 * Notify the error to all possible sockets via pfctlinput2.
497 * Since the upper layer information (such as protocol type,
498 * source and destination ports) is embedded in the encrypted
499 * data and might have been cut, we can't directly call
500 * an upper layer ctlinput function. However, the pcbnotify
501 * function will consider source and destination addresses
502 * as well as the flow info value, and may be able to find
503 * some PCB that should be notified.
504 * Although pfctlinput2 will call esp6_ctlinput(), there is
505 * no possibility of an infinite loop of function calls,
506 * because we don't pass the inner IPv6 header.
508 bzero(&ip6cp1, sizeof(ip6cp1));
509 ip6cp1.ip6c_src = ip6cp->ip6c_src;
510 pfctlinput2(cmd, sa, (void *)&ip6cp1);
513 * Then go to special cases that need ESP header information.
514 * XXX: We assume that when ip6 is non NULL,
515 * M and OFF are valid.
518 if (cmd == PRC_MSGSIZE) {
519 struct secasvar *sav;
523 /* check header length before using m_copydata */
524 if (m->m_pkthdr.len < off + sizeof (struct esp))
526 m_copydata(m, off + offsetof(struct esp, esp_spi),
527 sizeof(u_int32_t), (caddr_t) &spi);
529 * Check to see if we have a valid SA corresponding to
530 * the address in the ICMP message payload.
532 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
534 valid = (sav != NULL);
538 /* XXX Further validation? */
541 * Depending on whether the SA is "valid" and
542 * routing table size (mtudisc_{hi,lo}wat), we will:
543 * - recalcurate the new MTU and create the
544 * corresponding routing entry, or
545 * - ignore the MTU change notification.
547 icmp6_mtudisc_update(ip6cp, valid);
550 /* we normally notify any pcb here */
554 extern struct ip6protosw inet6sw[];
555 extern u_char ip6_protox[];
558 * IPsec input callback, called by the transform callback. Takes care of
559 * filtering and other sanity checks on the processed packet.
562 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
565 int prot, af, sproto;
568 struct tdb_ident *tdbi;
569 struct secasindex *saidx;
574 KASSERT(m != NULL, ("ipsec6_common_input_cb: null mbuf"));
575 KASSERT(sav != NULL, ("ipsec6_common_input_cb: null SA"));
576 KASSERT(sav->sah != NULL, ("ipsec6_common_input_cb: null SAH"));
577 saidx = &sav->sah->saidx;
578 af = saidx->dst.sa.sa_family;
579 KASSERT(af == AF_INET6,
580 ("ipsec6_common_input_cb: unexpected af %u", af));
581 sproto = saidx->proto;
582 KASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
583 sproto == IPPROTO_IPCOMP,
584 ("ipsec6_common_input_cb: unexpected security protocol %u",
589 DPRINTF(("ipsec4_common_input_cb: null mbuf"));
590 IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
591 ipcompstat.ipcomps_badkcr);
596 /* Fix IPv6 header */
597 if (m->m_len < sizeof(struct ip6_hdr) &&
598 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
600 DPRINTF(("ipsec_common_input_cb: processing failed "
601 "for SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst),
602 (u_long) ntohl(sav->spi)));
604 IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
605 ipcompstat.ipcomps_hdrops);
610 ip6 = mtod(m, struct ip6_hdr *);
611 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
614 m_copydata(m, protoff, 1, (unsigned char *) &prot);
617 /* IP-in-IP encapsulation */
618 if (prot == IPPROTO_IPIP) {
621 /* ipn will now contain the inner IPv4 header */
622 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
626 * Check that the inner source address is the same as
627 * the proxy address, if available.
629 if ((saidx->proxy.sa.sa_family == AF_INET &&
630 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
631 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
632 (saidx->proxy.sa.sa_family != AF_INET &&
633 saidx->proxy.sa.sa_family != 0)) {
635 DPRINTF(("ipsec_common_input_cb: inner "
636 "source address %s doesn't correspond to "
637 "expected proxy source %s, SA %s/%08lx\n",
638 inet_ntoa4(ipn.ip_src),
639 ipsec_address(&saidx->proxy),
640 ipsec_address(&saidx->dst),
641 (u_long) ntohl(sav->spi)));
643 IPSEC_ISTATsproto, (espstat.esps_pdrops,
644 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
652 /* IPv6-in-IP encapsulation */
653 if (prot == IPPROTO_IPV6) {
656 /* ip6n will now contain the inner IPv6 header. */
657 m_copydata(m, skip, sizeof(struct ip6_hdr),
662 * Check that the inner source address is the same as
663 * the proxy address, if available.
665 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
666 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
667 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
668 &saidx->proxy.sin6.sin6_addr)) ||
669 (saidx->proxy.sa.sa_family != AF_INET6 &&
670 saidx->proxy.sa.sa_family != 0)) {
672 DPRINTF(("ipsec_common_input_cb: inner "
673 "source address %s doesn't correspond to "
674 "expected proxy source %s, SA %s/%08lx\n",
675 ip6_sprintf(&ip6n.ip6_src),
676 ipsec_address(&saidx->proxy),
677 ipsec_address(&saidx->dst),
678 (u_long) ntohl(sav->spi)));
680 IPSEC_ISTAT(sproto, espstat.esps_pdrops,
681 ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
689 * Record what we've done to the packet (under what SA it was
690 * processed). If we've been passed an mtag, it means the packet
691 * was already processed by an ethernet/crypto combo card and
692 * thus has a tag attached with all the right information, but
693 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
694 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
696 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
697 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
698 sizeof(struct tdb_ident), M_NOWAIT);
700 DPRINTF(("ipsec_common_input_cb: failed to "
702 IPSEC_ISTAT(sproto, espstat.esps_hdrops,
703 ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
708 tdbi = (struct tdb_ident *)(mtag + 1);
709 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
710 tdbi->proto = sproto;
711 tdbi->spi = sav->spi;
713 m_tag_prepend(m, mtag);
715 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
716 /* XXX do we need to mark m_flags??? */
719 key_sa_recordxfer(sav, m);
721 /* Retrieve new protocol */
722 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
725 * See the end of ip6_input for this logic.
726 * IPPROTO_IPV[46] case will be processed just like other ones
730 while (nxt != IPPROTO_DONE) {
731 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
732 ip6stat.ip6s_toomanyhdr++;
738 * Protection against faulty packet - there should be
739 * more sanity checks in header chain processing.
741 if (m->m_pkthdr.len < skip) {
742 ip6stat.ip6s_tooshort++;
743 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
748 * Enforce IPsec policy checking if we are seeing last header.
749 * note that we do not visit this with protocols with pcb layer
750 * code - like udp/tcp/raw ip.
752 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
753 ipsec6_in_reject(m, NULL)) {
757 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);