2 /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */
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).
8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
17 * Additional features in 1999 by Angelos D. Keromytis.
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.
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
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
40 * IPsec input processing.
44 #include "opt_inet6.h"
45 #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/if_var.h>
61 #include <net/route.h>
62 #include <net/netisr.h>
65 #include <netinet/in.h>
66 #include <netinet/in_systm.h>
67 #include <netinet/ip.h>
68 #include <netinet/ip_var.h>
69 #include <netinet/in_var.h>
71 #include <netinet/ip6.h>
73 #include <netinet6/ip6_var.h>
75 #include <netinet/in_pcb.h>
77 #include <netinet/icmp6.h>
80 #include <netipsec/ipsec.h>
82 #include <netipsec/ipsec6.h>
84 #include <netipsec/ah_var.h>
85 #include <netipsec/esp.h>
86 #include <netipsec/esp_var.h>
87 #include <netipsec/ipcomp_var.h>
89 #include <netipsec/key.h>
90 #include <netipsec/keydb.h>
92 #include <netipsec/xform.h>
93 #include <netinet6/ip6protosw.h>
95 #include <machine/in_cksum.h>
96 #include <machine/stdarg.h>
99 #include <net/if_enc.h>
103 #define IPSEC_ISTAT(proto, name) do { \
104 if ((proto) == IPPROTO_ESP) \
105 ESPSTAT_INC(esps_##name); \
106 else if ((proto) == IPPROTO_AH) \
107 AHSTAT_INC(ahs_##name); \
109 IPCOMPSTAT_INC(ipcomps_##name); \
113 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
117 * ipsec_common_input gets called when an IPsec-protected packet
118 * is received by IPv4 or IPv6. Its job is to find the right SA
119 * and call the appropriate transform. The transform callback
120 * takes care of further processing (like ingress filtering).
123 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
125 union sockaddr_union dst_address;
126 struct secasvar *sav;
135 IPSEC_ISTAT(sproto, input);
137 IPSEC_ASSERT(m != NULL, ("null packet"));
139 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
140 sproto == IPPROTO_IPCOMP,
141 ("unexpected security protocol %u", sproto));
143 if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
144 (sproto == IPPROTO_AH && !V_ah_enable) ||
145 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
147 IPSEC_ISTAT(sproto, pdrops);
151 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
153 IPSEC_ISTAT(sproto, hdrops);
154 DPRINTF(("%s: packet too small\n", __func__));
158 /* Retrieve the SPI from the relevant IPsec header */
159 if (sproto == IPPROTO_ESP)
160 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
161 else if (sproto == IPPROTO_AH)
162 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
164 else if (sproto == IPPROTO_IPCOMP) {
166 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
168 spi = ntohl(htons(cpi));
172 * Find the SA and (indirectly) call the appropriate
173 * kernel crypto routine. The resulting mbuf chain is a valid
174 * IP packet ready to go through input processing.
176 bzero(&dst_address, sizeof (dst_address));
177 dst_address.sa.sa_family = af;
181 dst_address.sin.sin_len = sizeof(struct sockaddr_in);
182 m_copydata(m, offsetof(struct ip, ip_dst),
183 sizeof(struct in_addr),
184 (caddr_t) &dst_address.sin.sin_addr);
186 /* Find the source port for NAT-T; see udp*_espdecap. */
187 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL);
189 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1];
190 #endif /* IPSEC_NAT_T */
195 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
196 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
197 sizeof(struct in6_addr),
198 (caddr_t) &dst_address.sin6.sin6_addr);
202 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
204 IPSEC_ISTAT(sproto, nopf);
208 /* NB: only pass dst since key_allocsa follows RFC2401 */
209 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
211 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
212 __func__, ipsec_address(&dst_address),
213 (u_long) ntohl(spi), sproto));
214 IPSEC_ISTAT(sproto, notdb);
219 if (sav->tdb_xform == NULL) {
220 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
221 __func__, ipsec_address(&dst_address),
222 (u_long) ntohl(spi), sproto));
223 IPSEC_ISTAT(sproto, noxform);
230 * Call appropriate transform and return -- callback takes care of
233 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
240 * Common input handler for IPv4 AH, ESP, and IPCOMP.
243 ipsec4_common_input(struct mbuf *m, ...)
249 off = va_arg(ap, int);
250 nxt = va_arg(ap, int);
253 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
258 ah4_input(struct mbuf *m, int off)
260 ipsec4_common_input(m, off, IPPROTO_AH);
263 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
265 if (sa->sa_family == AF_INET &&
266 sa->sa_len == sizeof(struct sockaddr_in))
267 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
271 esp4_input(struct mbuf *m, int off)
273 ipsec4_common_input(m, off, IPPROTO_ESP);
276 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
278 if (sa->sa_family == AF_INET &&
279 sa->sa_len == sizeof(struct sockaddr_in))
280 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
284 ipcomp4_input(struct mbuf *m, int off)
286 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
290 * IPsec input callback for INET protocols.
291 * This routine is called as the transform callback.
292 * Takes care of filtering and other sanity checks on
293 * the processed packet.
296 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
297 int skip, int protoff, struct m_tag *mt)
299 int prot, af, sproto;
302 struct tdb_ident *tdbi;
303 struct secasindex *saidx;
307 char ip6buf[INET6_ADDRSTRLEN];
311 IPSEC_ASSERT(m != NULL, ("null mbuf"));
312 IPSEC_ASSERT(sav != NULL, ("null SA"));
313 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
314 saidx = &sav->sah->saidx;
315 af = saidx->dst.sa.sa_family;
316 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
317 sproto = saidx->proto;
318 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
319 sproto == IPPROTO_IPCOMP,
320 ("unexpected security protocol %u", sproto));
324 DPRINTF(("%s: null mbuf", __func__));
325 IPSEC_ISTAT(sproto, badkcr);
333 * XXXGL: do we need this entire block?
335 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
336 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
337 __func__, ipsec_address(&sav->sah->saidx.dst),
338 (u_long) ntohl(sav->spi)));
339 IPSEC_ISTAT(sproto, hdrops);
344 ip = mtod(m, struct ip *);
345 ip->ip_len = htons(m->m_pkthdr.len);
347 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
349 ip = mtod(m, struct ip *);
354 /* IP-in-IP encapsulation */
355 if (prot == IPPROTO_IPIP) {
358 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
359 IPSEC_ISTAT(sproto, hdrops);
363 /* ipn will now contain the inner IPv4 header */
364 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
367 /* XXX PROXY address isn't recorded in SAH */
369 * Check that the inner source address is the same as
370 * the proxy address, if available.
372 if ((saidx->proxy.sa.sa_family == AF_INET &&
373 saidx->proxy.sin.sin_addr.s_addr !=
376 saidx->proxy.sin.sin_addr.s_addr) ||
377 (saidx->proxy.sa.sa_family != AF_INET &&
378 saidx->proxy.sa.sa_family != 0)) {
380 DPRINTF(("%s: inner source address %s doesn't "
381 "correspond to expected proxy source %s, "
382 "SA %s/%08lx\n", __func__,
383 inet_ntoa4(ipn.ip_src),
384 ipsp_address(saidx->proxy),
385 ipsp_address(saidx->dst),
386 (u_long) ntohl(sav->spi)));
388 IPSEC_ISTAT(sproto, pdrops);
394 /* IPv6-in-IP encapsulation. */
395 if (prot == IPPROTO_IPV6) {
398 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
399 IPSEC_ISTAT(sproto, hdrops);
403 /* ip6n will now contain the inner IPv6 header. */
404 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
408 * Check that the inner source address is the same as
409 * the proxy address, if available.
411 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
412 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
413 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
414 &saidx->proxy.sin6.sin6_addr)) ||
415 (saidx->proxy.sa.sa_family != AF_INET6 &&
416 saidx->proxy.sa.sa_family != 0)) {
418 DPRINTF(("%s: inner source address %s doesn't "
419 "correspond to expected proxy source %s, "
420 "SA %s/%08lx\n", __func__,
421 ip6_sprintf(ip6buf, &ip6n.ip6_src),
422 ipsec_address(&saidx->proxy),
423 ipsec_address(&saidx->dst),
424 (u_long) ntohl(sav->spi)));
426 IPSEC_ISTAT(sproto, pdrops);
435 * Record what we've done to the packet (under what SA it was
436 * processed). If we've been passed an mtag, it means the packet
437 * was already processed by an ethernet/crypto combo card and
438 * thus has a tag attached with all the right information, but
439 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
440 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
442 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
443 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
444 sizeof(struct tdb_ident), M_NOWAIT);
446 DPRINTF(("%s: failed to get tag\n", __func__));
447 IPSEC_ISTAT(sproto, hdrops);
452 tdbi = (struct tdb_ident *)(mtag + 1);
453 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
454 tdbi->proto = sproto;
455 tdbi->spi = sav->spi;
456 /* Cache those two for enc(4) in xform_ipip. */
457 tdbi->alg_auth = sav->alg_auth;
458 tdbi->alg_enc = sav->alg_enc;
460 m_tag_prepend(m, mtag);
461 } else if (mt != NULL) {
462 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
463 /* XXX do we need to mark m_flags??? */
466 key_sa_recordxfer(sav, m); /* record data transfer */
469 encif->if_ipackets++;
470 encif->if_ibytes += m->m_pkthdr.len;
473 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
474 * packet later after it has been decapsulated.
476 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE);
478 if (prot != IPPROTO_IPIP)
479 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
484 * Re-dispatch via software interrupt.
486 if ((error = netisr_queue_src(NETISR_IP, (uintptr_t)sav->spi, m))) {
487 IPSEC_ISTAT(sproto, qfull);
488 DPRINTF(("%s: queue full; proto %u packet dropped\n",
499 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
501 /* XXX nothing just yet */
506 /* IPv6 AH wrapper. */
508 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
514 if (*offp < sizeof(struct ip6_hdr)) {
515 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
517 } else if (*offp == sizeof(struct ip6_hdr)) {
518 protoff = offsetof(struct ip6_hdr, ip6_nxt);
520 /* Chase down the header chain... */
521 protoff = sizeof(struct ip6_hdr);
525 m_copydata(*mp, protoff, sizeof(ip6e),
528 if (ip6e.ip6e_nxt == IPPROTO_AH)
529 l = (ip6e.ip6e_len + 2) << 2;
531 l = (ip6e.ip6e_len + 1) << 3;
532 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
533 } while (protoff + l < *offp);
535 /* Malformed packet check */
536 if (protoff + l != *offp) {
537 DPRINTF(("%s: bad packet header chain, protoff %u, "
538 "l %u, off %u\n", __func__, protoff, l, *offp));
539 IPSEC_ISTAT(proto, hdrops);
544 protoff += offsetof(struct ip6_ext, ip6e_nxt);
546 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
551 * IPsec input callback, called by the transform callback. Takes care of
552 * filtering and other sanity checks on the processed packet.
555 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
558 int prot, af, sproto;
561 struct tdb_ident *tdbi;
562 struct secasindex *saidx;
567 char ip6buf[INET6_ADDRSTRLEN];
570 IPSEC_ASSERT(m != NULL, ("null mbuf"));
571 IPSEC_ASSERT(sav != NULL, ("null SA"));
572 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
573 saidx = &sav->sah->saidx;
574 af = saidx->dst.sa.sa_family;
575 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
576 sproto = saidx->proto;
577 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
578 sproto == IPPROTO_IPCOMP,
579 ("unexpected security protocol %u", sproto));
583 DPRINTF(("%s: null mbuf", __func__));
584 IPSEC_ISTAT(sproto, badkcr);
589 /* Fix IPv6 header */
590 if (m->m_len < sizeof(struct ip6_hdr) &&
591 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
593 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
594 __func__, ipsec_address(&sav->sah->saidx.dst),
595 (u_long) ntohl(sav->spi)));
597 IPSEC_ISTAT(sproto, hdrops);
602 ip6 = mtod(m, struct ip6_hdr *);
603 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
607 m_copydata(m, protoff, 1, (unsigned char *) &prot);
611 /* IP-in-IP encapsulation */
612 if (prot == IPPROTO_IPIP) {
615 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
616 IPSEC_ISTAT(sproto, hdrops);
620 /* ipn will now contain the inner IPv4 header */
621 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
624 * Check that the inner source address is the same as
625 * the proxy address, if available.
627 if ((saidx->proxy.sa.sa_family == AF_INET &&
628 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
629 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
630 (saidx->proxy.sa.sa_family != AF_INET &&
631 saidx->proxy.sa.sa_family != 0)) {
633 DPRINTF(("%s: inner source address %s doesn't "
634 "correspond to expected proxy source %s, "
635 "SA %s/%08lx\n", __func__,
636 inet_ntoa4(ipn.ip_src),
637 ipsec_address(&saidx->proxy),
638 ipsec_address(&saidx->dst),
639 (u_long) ntohl(sav->spi)));
641 IPSEC_ISTAT(sproto, pdrops);
648 /* IPv6-in-IP encapsulation */
649 if (prot == IPPROTO_IPV6) {
652 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
653 IPSEC_ISTAT(sproto, hdrops);
657 /* ip6n will now contain the inner IPv6 header. */
658 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(("%s: inner source address %s doesn't "
673 "correspond to expected proxy source %s, "
674 "SA %s/%08lx\n", __func__,
675 ip6_sprintf(ip6buf, &ip6n.ip6_src),
676 ipsec_address(&saidx->proxy),
677 ipsec_address(&saidx->dst),
678 (u_long) ntohl(sav->spi)));
680 IPSEC_ISTAT(sproto, pdrops);
688 * Record what we've done to the packet (under what SA it was
689 * processed). If we've been passed an mtag, it means the packet
690 * was already processed by an ethernet/crypto combo card and
691 * thus has a tag attached with all the right information, but
692 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
693 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
695 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
696 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
697 sizeof(struct tdb_ident), M_NOWAIT);
699 DPRINTF(("%s: failed to get tag\n", __func__));
700 IPSEC_ISTAT(sproto, hdrops);
705 tdbi = (struct tdb_ident *)(mtag + 1);
706 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
707 tdbi->proto = sproto;
708 tdbi->spi = sav->spi;
709 /* Cache those two for enc(4) in xform_ipip. */
710 tdbi->alg_auth = sav->alg_auth;
711 tdbi->alg_enc = sav->alg_enc;
713 m_tag_prepend(m, mtag);
716 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
717 /* XXX do we need to mark m_flags??? */
720 key_sa_recordxfer(sav, m);
723 encif->if_ipackets++;
724 encif->if_ibytes += m->m_pkthdr.len;
727 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
728 * packet later after it has been decapsulated.
730 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE);
732 /* XXX-BZ does not make sense. */
733 if (prot != IPPROTO_IPIP)
734 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
738 /* Retrieve new protocol */
739 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
742 * See the end of ip6_input for this logic.
743 * IPPROTO_IPV[46] case will be processed just like other ones
747 while (nxt != IPPROTO_DONE) {
748 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
749 IP6STAT_INC(ip6s_toomanyhdr);
755 * Protection against faulty packet - there should be
756 * more sanity checks in header chain processing.
758 if (m->m_pkthdr.len < skip) {
759 IP6STAT_INC(ip6s_tooshort);
760 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
765 * Enforce IPsec policy checking if we are seeing last header.
766 * note that we do not visit this with protocols with pcb layer
767 * code - like udp/tcp/raw ip.
769 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
770 ipsec6_in_reject(m, NULL)) {
774 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
784 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
786 struct ip6ctlparam *ip6cp = NULL;
787 struct mbuf *m = NULL;
791 if (sa->sa_family != AF_INET6 ||
792 sa->sa_len != sizeof(struct sockaddr_in6))
794 if ((unsigned)cmd >= PRC_NCMDS)
797 /* if the parameter is from icmp6, decode it. */
799 ip6cp = (struct ip6ctlparam *)d;
801 ip6 = ip6cp->ip6c_ip6;
802 off = ip6cp->ip6c_off;
806 off = 0; /* calm gcc */
811 struct ip6ctlparam ip6cp1;
814 * Notify the error to all possible sockets via pfctlinput2.
815 * Since the upper layer information (such as protocol type,
816 * source and destination ports) is embedded in the encrypted
817 * data and might have been cut, we can't directly call
818 * an upper layer ctlinput function. However, the pcbnotify
819 * function will consider source and destination addresses
820 * as well as the flow info value, and may be able to find
821 * some PCB that should be notified.
822 * Although pfctlinput2 will call esp6_ctlinput(), there is
823 * no possibility of an infinite loop of function calls,
824 * because we don't pass the inner IPv6 header.
826 bzero(&ip6cp1, sizeof(ip6cp1));
827 ip6cp1.ip6c_src = ip6cp->ip6c_src;
828 pfctlinput2(cmd, sa, (void *)&ip6cp1);
831 * Then go to special cases that need ESP header information.
832 * XXX: We assume that when ip6 is non NULL,
833 * M and OFF are valid.
836 if (cmd == PRC_MSGSIZE) {
837 struct secasvar *sav;
841 /* check header length before using m_copydata */
842 if (m->m_pkthdr.len < off + sizeof (struct esp))
844 m_copydata(m, off + offsetof(struct esp, esp_spi),
845 sizeof(u_int32_t), (caddr_t) &spi);
847 * Check to see if we have a valid SA corresponding to
848 * the address in the ICMP message payload.
850 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
852 valid = (sav != NULL);
856 /* XXX Further validation? */
859 * Depending on whether the SA is "valid" and
860 * routing table size (mtudisc_{hi,lo}wat), we will:
861 * - recalcurate the new MTU and create the
862 * corresponding routing entry, or
863 * - ignore the MTU change notification.
865 icmp6_mtudisc_update(ip6cp, valid);
868 /* we normally notify any pcb here */