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