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MFC r274230:
[FreeBSD/stable/10.git] / sys / netipsec / ipsec_output.c
1 /*-
2  * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28
29 /*
30  * IPsec output processing.
31  */
32 #include "opt_inet.h"
33 #include "opt_inet6.h"
34 #include "opt_ipsec.h"
35 #include "opt_enc.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/mbuf.h>
40 #include <sys/domain.h>
41 #include <sys/protosw.h>
42 #include <sys/socket.h>
43 #include <sys/errno.h>
44 #include <sys/syslog.h>
45
46 #include <net/if.h>
47 #include <net/pfil.h>
48 #include <net/route.h>
49 #include <net/vnet.h>
50
51 #include <netinet/in.h>
52 #include <netinet/in_systm.h>
53 #include <netinet/ip.h>
54 #include <netinet/ip_var.h>
55 #include <netinet/in_var.h>
56 #include <netinet/ip_ecn.h>
57 #ifdef INET6
58 #include <netinet6/ip6_ecn.h>
59 #endif
60
61 #include <netinet/ip6.h>
62 #ifdef INET6
63 #include <netinet6/ip6_var.h>
64 #endif
65 #include <netinet/in_pcb.h>
66 #ifdef INET6
67 #include <netinet/icmp6.h>
68 #endif
69
70 #include <netipsec/ipsec.h>
71 #ifdef INET6
72 #include <netipsec/ipsec6.h>
73 #endif
74 #include <netipsec/ah_var.h>
75 #include <netipsec/esp_var.h>
76 #include <netipsec/ipcomp_var.h>
77
78 #include <netipsec/xform.h>
79
80 #include <netipsec/key.h>
81 #include <netipsec/keydb.h>
82 #include <netipsec/key_debug.h>
83
84 #include <machine/in_cksum.h>
85
86 #ifdef IPSEC_NAT_T
87 #include <netinet/udp.h>
88 #endif
89
90 #ifdef DEV_ENC
91 #include <net/if_enc.h>
92 #endif
93
94
95 int
96 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
97 {
98         struct tdb_ident *tdbi;
99         struct m_tag *mtag;
100         struct secasvar *sav;
101         struct secasindex *saidx;
102         int error;
103
104         IPSEC_ASSERT(m != NULL, ("null mbuf"));
105         IPSEC_ASSERT(isr != NULL, ("null ISR"));
106         sav = isr->sav;
107         IPSEC_ASSERT(sav != NULL, ("null SA"));
108         IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
109
110         saidx = &sav->sah->saidx;
111         switch (saidx->dst.sa.sa_family) {
112 #ifdef INET
113         case AF_INET:
114                 /* Fix the header length, for AH processing. */
115                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
116                 break;
117 #endif /* INET */
118 #ifdef INET6
119         case AF_INET6:
120                 /* Fix the header length, for AH processing. */
121                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
122                         error = ENXIO;
123                         goto bad;
124                 }
125                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
126                         /* No jumbogram support. */
127                         error = ENXIO;  /*?*/
128                         goto bad;
129                 }
130                 mtod(m, struct ip6_hdr *)->ip6_plen =
131                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
132                 break;
133 #endif /* INET6 */
134         default:
135                 DPRINTF(("%s: unknown protocol family %u\n", __func__,
136                     saidx->dst.sa.sa_family));
137                 error = ENXIO;
138                 goto bad;
139         }
140
141         /*
142          * Add a record of what we've done or what needs to be done to the
143          * packet.
144          */
145         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
146                         sizeof(struct tdb_ident), M_NOWAIT);
147         if (mtag == NULL) {
148                 DPRINTF(("%s: could not get packet tag\n", __func__));
149                 error = ENOMEM;
150                 goto bad;
151         }
152
153         tdbi = (struct tdb_ident *)(mtag + 1);
154         tdbi->dst = saidx->dst;
155         tdbi->proto = saidx->proto;
156         tdbi->spi = sav->spi;
157         m_tag_prepend(m, mtag);
158
159         /*
160          * If there's another (bundled) SA to apply, do so.
161          * Note that this puts a burden on the kernel stack size.
162          * If this is a problem we'll need to introduce a queue
163          * to set the packet on so we can unwind the stack before
164          * doing further processing.
165          */
166         if (isr->next) {
167                 /* XXX-BZ currently only support same AF bundles. */
168                 switch (saidx->dst.sa.sa_family) {
169 #ifdef INET
170                 case AF_INET:
171                         IPSECSTAT_INC(ips_out_bundlesa);
172                         return ipsec4_process_packet(m, isr->next, 0, 0);
173                         /* NOTREACHED */
174 #endif
175 #ifdef notyet
176 #ifdef INET6
177                 case AF_INET6:
178                         /* XXX */
179                         IPSEC6STAT_INC(ips_out_bundlesa);
180                         return ipsec6_process_packet(m, isr->next);
181                         /* NOTREACHED */
182 #endif /* INET6 */
183 #endif
184                 default:
185                         DPRINTF(("%s: unknown protocol family %u\n", __func__,
186                             saidx->dst.sa.sa_family));
187                         error = ENXIO;
188                         goto bad;
189                 }
190         }
191         key_sa_recordxfer(sav, m);              /* record data transfer */
192
193         /*
194          * We're done with IPsec processing, transmit the packet using the
195          * appropriate network protocol (IP or IPv6). SPD lookup will be
196          * performed again there.
197          */
198         switch (saidx->dst.sa.sa_family) {
199 #ifdef INET
200         case AF_INET:
201 #ifdef IPSEC_NAT_T
202                 /*
203                  * If NAT-T is enabled, now that all IPsec processing is done
204                  * insert UDP encapsulation header after IP header.
205                  */
206                 if (sav->natt_type) {
207                         struct ip *ip = mtod(m, struct ip *);
208                         const int hlen = (ip->ip_hl << 2);
209                         int size, off;
210                         struct mbuf *mi;
211                         struct udphdr *udp;
212
213                         size = sizeof(struct udphdr);
214                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
215                                 /*
216                                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
217                                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
218                                  * ignoring possible AH mode
219                                  * non-IKE marker + non-ESP marker
220                                  * from draft-ietf-ipsec-udp-encaps-00.txt.
221                                  */
222                                 size += sizeof(u_int64_t);
223                         }
224                         mi = m_makespace(m, hlen, size, &off);
225                         if (mi == NULL) {
226                                 DPRINTF(("%s: m_makespace for udphdr failed\n",
227                                     __func__));
228                                 error = ENOBUFS;
229                                 goto bad;
230                         }
231
232                         udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
233                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
234                                 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
235                         else
236                                 udp->uh_sport =
237                                         KEY_PORTFROMSADDR(&sav->sah->saidx.src);
238                         udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
239                         udp->uh_sum = 0;
240                         udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
241                         ip->ip_len = htons(m->m_pkthdr.len);
242                         ip->ip_p = IPPROTO_UDP;
243
244                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
245                                 *(u_int64_t *)(udp + 1) = 0;
246                 }
247 #endif /* IPSEC_NAT_T */
248
249                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
250 #endif /* INET */
251 #ifdef INET6
252         case AF_INET6:
253                 /*
254                  * We don't need massage, IPv6 header fields are always in
255                  * net endian.
256                  */
257                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
258 #endif /* INET6 */
259         }
260         panic("ipsec_process_done");
261 bad:
262         m_freem(m);
263         return (error);
264 }
265
266 static struct ipsecrequest *
267 ipsec_nextisr(
268         struct mbuf *m,
269         struct ipsecrequest *isr,
270         int af,
271         struct secasindex *saidx,
272         int *error
273 )
274 {
275 #define IPSEC_OSTAT(name)       do {            \
276         if (isr->saidx.proto == IPPROTO_ESP)    \
277                 ESPSTAT_INC(esps_##name);       \
278         else if (isr->saidx.proto == IPPROTO_AH)\
279                 AHSTAT_INC(ahs_##name);         \
280         else                                    \
281                 IPCOMPSTAT_INC(ipcomps_##name); \
282 } while (0)
283         struct secasvar *sav;
284
285         IPSECREQUEST_LOCK_ASSERT(isr);
286
287         IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
288                 ("invalid address family %u", af));
289 again:
290         /*
291          * Craft SA index to search for proper SA.  Note that
292          * we only fillin unspecified SA peers for transport
293          * mode; for tunnel mode they must already be filled in.
294          */
295         *saidx = isr->saidx;
296         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
297                 /* Fillin unspecified SA peers only for transport mode */
298                 if (af == AF_INET) {
299                         struct sockaddr_in *sin;
300                         struct ip *ip = mtod(m, struct ip *);
301
302                         if (saidx->src.sa.sa_len == 0) {
303                                 sin = &saidx->src.sin;
304                                 sin->sin_len = sizeof(*sin);
305                                 sin->sin_family = AF_INET;
306                                 sin->sin_port = IPSEC_PORT_ANY;
307                                 sin->sin_addr = ip->ip_src;
308                         }
309                         if (saidx->dst.sa.sa_len == 0) {
310                                 sin = &saidx->dst.sin;
311                                 sin->sin_len = sizeof(*sin);
312                                 sin->sin_family = AF_INET;
313                                 sin->sin_port = IPSEC_PORT_ANY;
314                                 sin->sin_addr = ip->ip_dst;
315                         }
316                 } else {
317                         struct sockaddr_in6 *sin6;
318                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
319
320                         if (saidx->src.sin6.sin6_len == 0) {
321                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
322                                 sin6->sin6_len = sizeof(*sin6);
323                                 sin6->sin6_family = AF_INET6;
324                                 sin6->sin6_port = IPSEC_PORT_ANY;
325                                 sin6->sin6_addr = ip6->ip6_src;
326                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
327                                         /* fix scope id for comparing SPD */
328                                         sin6->sin6_addr.s6_addr16[1] = 0;
329                                         sin6->sin6_scope_id =
330                                             ntohs(ip6->ip6_src.s6_addr16[1]);
331                                 }
332                         }
333                         if (saidx->dst.sin6.sin6_len == 0) {
334                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
335                                 sin6->sin6_len = sizeof(*sin6);
336                                 sin6->sin6_family = AF_INET6;
337                                 sin6->sin6_port = IPSEC_PORT_ANY;
338                                 sin6->sin6_addr = ip6->ip6_dst;
339                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
340                                         /* fix scope id for comparing SPD */
341                                         sin6->sin6_addr.s6_addr16[1] = 0;
342                                         sin6->sin6_scope_id =
343                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
344                                 }
345                         }
346                 }
347         }
348
349         /*
350          * Lookup SA and validate it.
351          */
352         *error = key_checkrequest(isr, saidx);
353         if (*error != 0) {
354                 /*
355                  * IPsec processing is required, but no SA found.
356                  * I assume that key_acquire() had been called
357                  * to get/establish the SA. Here I discard
358                  * this packet because it is responsibility for
359                  * upper layer to retransmit the packet.
360                  */
361                 switch(af) {
362                 case AF_INET:
363                         IPSECSTAT_INC(ips_out_nosa);
364                         break;
365 #ifdef INET6
366                 case AF_INET6:
367                         IPSEC6STAT_INC(ips_out_nosa);
368                         break;
369 #endif
370                 }
371                 goto bad;
372         }
373         sav = isr->sav;
374         if (sav == NULL) {
375                 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
376                         ("no SA found, but required; level %u",
377                         ipsec_get_reqlevel(isr)));
378                 IPSECREQUEST_UNLOCK(isr);
379                 isr = isr->next;
380                 /*
381                  * If isr is NULL, we found a 'use' policy w/o SA.
382                  * Return w/o error and w/o isr so we can drop out
383                  * and continue w/o IPsec processing.
384                  */
385                 if (isr == NULL)
386                         return isr;
387                 IPSECREQUEST_LOCK(isr);
388                 goto again;
389         }
390
391         /*
392          * Check system global policy controls.
393          */
394         if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
395             (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
396             (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
397                 DPRINTF(("%s: IPsec outbound packet dropped due"
398                         " to policy (check your sysctls)\n", __func__));
399                 IPSEC_OSTAT(pdrops);
400                 *error = EHOSTUNREACH;
401                 goto bad;
402         }
403
404         /*
405          * Sanity check the SA contents for the caller
406          * before they invoke the xform output method.
407          */
408         if (sav->tdb_xform == NULL) {
409                 DPRINTF(("%s: no transform for SA\n", __func__));
410                 IPSEC_OSTAT(noxform);
411                 *error = EHOSTUNREACH;
412                 goto bad;
413         }
414         return isr;
415 bad:
416         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
417         IPSECREQUEST_UNLOCK(isr);
418         return NULL;
419 #undef IPSEC_OSTAT
420 }
421
422 #ifdef INET
423 /*
424  * IPsec output logic for IPv4.
425  */
426 int
427 ipsec4_process_packet(
428         struct mbuf *m,
429         struct ipsecrequest *isr,
430         int flags,
431         int tunalready)
432 {
433         struct secasindex saidx;
434         struct secasvar *sav;
435         struct ip *ip;
436         int error, i, off;
437
438         IPSEC_ASSERT(m != NULL, ("null mbuf"));
439         IPSEC_ASSERT(isr != NULL, ("null isr"));
440
441         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
442
443         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
444         if (isr == NULL) {
445                 if (error != 0)
446                         goto bad;
447                 return EJUSTRETURN;
448         }
449
450         sav = isr->sav;
451
452 #ifdef DEV_ENC
453         encif->if_opackets++;
454         encif->if_obytes += m->m_pkthdr.len;
455
456         /* pass the mbuf to enc0 for bpf processing */
457         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
458         /* pass the mbuf to enc0 for packet filtering */
459         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
460                 goto bad;
461 #endif
462
463         if (!tunalready) {
464                 union sockaddr_union *dst = &sav->sah->saidx.dst;
465                 int setdf;
466
467                 /*
468                  * Collect IP_DF state from the outer header.
469                  */
470                 if (dst->sa.sa_family == AF_INET) {
471                         if (m->m_len < sizeof (struct ip) &&
472                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
473                                 error = ENOBUFS;
474                                 goto bad;
475                         }
476                         ip = mtod(m, struct ip *);
477                         /* Honor system-wide control of how to handle IP_DF */
478                         switch (V_ip4_ipsec_dfbit) {
479                         case 0:                 /* clear in outer header */
480                         case 1:                 /* set in outer header */
481                                 setdf = V_ip4_ipsec_dfbit;
482                                 break;
483                         default:                /* propagate to outer header */
484                                 setdf = ntohs(ip->ip_off & IP_DF);
485                                 break;
486                         }
487                 } else {
488                         ip = NULL;              /* keep compiler happy */
489                         setdf = 0;
490                 }
491                 /* Do the appropriate encapsulation, if necessary */
492                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
493                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
494 #if 0
495                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
496                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
497 #endif
498                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
499                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
500                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
501                         struct mbuf *mp;
502
503                         /* Fix IPv4 header checksum and length */
504                         if (m->m_len < sizeof (struct ip) &&
505                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
506                                 error = ENOBUFS;
507                                 goto bad;
508                         }
509                         ip = mtod(m, struct ip *);
510                         if (ip->ip_v == IPVERSION) {
511                                 ip->ip_len = htons(m->m_pkthdr.len);
512                                 ip->ip_sum = 0;
513                                 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
514                         }
515
516                         /* Encapsulate the packet */
517                         error = ipip_output(m, isr, &mp, 0, 0);
518                         if (mp == NULL && !error) {
519                                 /* Should never happen. */
520                                 DPRINTF(("%s: ipip_output returns no mbuf and "
521                                         "no error!", __func__));
522                                 error = EFAULT;
523                         }
524                         if (error) {
525                                 if (mp) {
526                                         /* XXX: Should never happen! */
527                                         m_freem(mp);
528                                 }
529                                 m = NULL; /* ipip_output() already freed it */
530                                 goto bad;
531                         }
532                         m = mp, mp = NULL;
533                         /*
534                          * ipip_output clears IP_DF in the new header.  If
535                          * we need to propagate IP_DF from the outer header,
536                          * then we have to do it here.
537                          *
538                          * XXX shouldn't assume what ipip_output does.
539                          */
540                         if (dst->sa.sa_family == AF_INET && setdf) {
541                                 if (m->m_len < sizeof (struct ip) &&
542                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
543                                         error = ENOBUFS;
544                                         goto bad;
545                                 }
546                                 ip = mtod(m, struct ip *);
547                                 ip->ip_off = ntohs(ip->ip_off);
548                                 ip->ip_off |= IP_DF;
549                                 ip->ip_off = htons(ip->ip_off);
550                         }
551                 }
552         }
553
554 #ifdef DEV_ENC
555         /* pass the mbuf to enc0 for bpf processing */
556         ipsec_bpf(m, sav, sav->sah->saidx.dst.sa.sa_family, ENC_OUT|ENC_AFTER);
557         /* pass the mbuf to enc0 for packet filtering */
558         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
559                 goto bad;
560 #endif
561
562         /*
563          * Dispatch to the appropriate IPsec transform logic.  The
564          * packet will be returned for transmission after crypto
565          * processing, etc. are completed.  For encapsulation we
566          * bypass this call because of the explicit call done above
567          * (necessary to deal with IP_DF handling for IPv4).
568          *
569          * NB: m & sav are ``passed to caller'' who's reponsible for
570          *     for reclaiming their resources.
571          */
572         if (sav->tdb_xform->xf_type != XF_IP4) {
573                 union sockaddr_union *dst = &sav->sah->saidx.dst;
574                 switch(dst->sa.sa_family) {
575                 case AF_INET:
576                         ip = mtod(m, struct ip *);
577                         i = ip->ip_hl << 2;
578                         off = offsetof(struct ip, ip_p);
579                         break;
580 #ifdef INET6
581                 case AF_INET6:
582                         i = sizeof(struct ip6_hdr);
583                         off = offsetof(struct ip6_hdr, ip6_nxt);
584                         break;
585 #endif /* INET6 */
586                 default:
587                 DPRINTF(("%s: unsupported protocol family %u\n",
588                                  __func__, dst->sa.sa_family));
589                         error = EPFNOSUPPORT;
590                         IPSECSTAT_INC(ips_out_inval);
591                         goto bad;
592                 }
593                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
594         } else {
595                 error = ipsec_process_done(m, isr);
596         }
597         IPSECREQUEST_UNLOCK(isr);
598         return error;
599 bad:
600         if (isr)
601                 IPSECREQUEST_UNLOCK(isr);
602         if (m)
603                 m_freem(m);
604         return error;
605 }
606 #endif
607
608
609 #ifdef INET6
610 static int
611 in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, const struct in6_addr *ia)
612 {
613         struct in6_addr ia2;
614
615         memcpy(&ia2, &sa->sin6_addr, sizeof(ia2));
616         if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr))
617                 ia2.s6_addr16[1] = htons(sa->sin6_scope_id);
618
619         return IN6_ARE_ADDR_EQUAL(ia, &ia2);
620 }
621
622 /*
623  * IPsec output logic for IPv6.
624  */
625 int
626 ipsec6_process_packet(
627         struct mbuf *m,
628         struct ipsecrequest *isr
629     )
630 {
631         struct secasindex saidx;
632         struct secasvar *sav;
633         struct ip6_hdr *ip6;
634         int error, i, off;
635         union sockaddr_union *dst;
636
637         IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf"));
638         IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr"));
639
640         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
641
642         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
643         if (isr == NULL) {
644                 if (error != 0)
645                         goto bad;
646                 return EJUSTRETURN;
647         }
648
649         sav = isr->sav;
650         dst = &sav->sah->saidx.dst;
651
652         ip6 = mtod(m, struct ip6_hdr *);
653         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
654 #ifdef DEV_ENC
655         encif->if_opackets++;
656         encif->if_obytes += m->m_pkthdr.len;
657
658         /* pass the mbuf to enc0 for bpf processing */
659         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
660         /* pass the mbuf to enc0 for packet filtering */
661         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
662                 goto bad;
663 #endif /* DEV_ENC */
664
665         /* Do the appropriate encapsulation, if necessary */
666         if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
667             dst->sa.sa_family != AF_INET6 ||        /* PF mismatch */
668             ((dst->sa.sa_family == AF_INET6) &&
669              (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) &&
670              (!in6_sa_equal_addrwithscope(&dst->sin6,
671                                   &ip6->ip6_dst)))) {
672                 struct mbuf *mp;
673
674                 /* Fix IPv6 header payload length. */
675                 if (m->m_len < sizeof(struct ip6_hdr))
676                         if ((m = m_pullup(m,sizeof(struct ip6_hdr))) == NULL) {
677                                 error = ENOBUFS;
678                                 goto bad;
679                         }
680
681                 if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) {
682                         /* No jumbogram support. */
683                         error = ENXIO;   /*XXX*/
684                         goto bad;
685                 }
686
687                 /* Encapsulate the packet */
688                 error = ipip_output(m, isr, &mp, 0, 0);
689                 if (mp == NULL && !error) {
690                         /* Should never happen. */
691                         DPRINTF(("ipsec6_process_packet: ipip_output "
692                                  "returns no mbuf and no error!"));
693                         error = EFAULT;
694                         goto bad;
695                 }
696
697                 if (error) {
698                         if (mp) {
699                                 /* XXX: Should never happen! */
700                                 m_freem(mp);
701                         }
702                         m = NULL; /* ipip_output() already freed it */
703                         goto bad;
704                 }
705
706                 m = mp;
707                 mp = NULL;
708         }
709
710 #ifdef DEV_ENC
711         ipsec_bpf(m, isr->sav, dst->sa.sa_family, ENC_OUT|ENC_AFTER);
712         /* pass the mbuf to enc0 for packet filtering */
713         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
714                 goto bad;
715 #endif /* DEV_ENC */
716
717         switch(dst->sa.sa_family) {
718 #ifdef INET
719         case AF_INET:
720                 {
721                 struct ip *ip;
722                 ip = mtod(m, struct ip *);
723                 i = ip->ip_hl << 2;
724                 off = offsetof(struct ip, ip_p);
725                 }
726                 break;
727 #endif /* AF_INET */
728         case AF_INET6:
729                 i = sizeof(struct ip6_hdr);
730                 off = offsetof(struct ip6_hdr, ip6_nxt);
731                 break;
732         default:
733                 DPRINTF(("%s: unsupported protocol family %u\n",
734                                  __func__, dst->sa.sa_family));
735                 error = EPFNOSUPPORT;
736                 IPSEC6STAT_INC(ips_out_inval);
737                 goto bad;
738         }
739         error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
740         IPSECREQUEST_UNLOCK(isr);
741         return error;
742 bad:
743
744         if (isr)
745                 IPSECREQUEST_UNLOCK(isr);
746         if (m)
747                 m_freem(m);
748         return error;
749 }
750 #endif /*INET6*/