ipsec_output.c revision 151967 
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: head/sys/netipsec/ipsec_output.c 151967 2005-11-02 13:46:32Z andre $
27 */
28
29/*
30 * IPsec output processing.
31 */
32#include "opt_inet.h"
33#include "opt_inet6.h"
34#include "opt_ipsec.h"
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/mbuf.h>
39#include <sys/domain.h>
40#include <sys/protosw.h>
41#include <sys/socket.h>
42#include <sys/errno.h>
43#include <sys/syslog.h>
44
45#include <net/if.h>
46#include <net/route.h>
47
48#include <netinet/in.h>
49#include <netinet/in_systm.h>
50#include <netinet/ip.h>
51#include <netinet/ip_var.h>
52#include <netinet/in_var.h>
53#include <netinet/ip_ecn.h>
54#ifdef INET6
55#include <netinet6/ip6_ecn.h>
56#endif
57
58#include <netinet/ip6.h>
59#ifdef INET6
60#include <netinet6/ip6_var.h>
61#endif
62#include <netinet/in_pcb.h>
63#ifdef INET6
64#include <netinet/icmp6.h>
65#endif
66
67#include <netipsec/ipsec.h>
68#ifdef INET6
69#include <netipsec/ipsec6.h>
70#endif
71#include <netipsec/ah_var.h>
72#include <netipsec/esp_var.h>
73#include <netipsec/ipcomp_var.h>
74
75#include <netipsec/xform.h>
76
77#include <netipsec/key.h>
78#include <netipsec/keydb.h>
79#include <netipsec/key_debug.h>
80
81#include <machine/in_cksum.h>
82
83int
84ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
85{
86	struct tdb_ident *tdbi;
87	struct m_tag *mtag;
88	struct secasvar *sav;
89	struct secasindex *saidx;
90	int error;
91
92	IPSEC_SPLASSERT_SOFTNET(__func__);
93
94	IPSEC_ASSERT(m != NULL, ("null mbuf"));
95	IPSEC_ASSERT(isr != NULL, ("null ISR"));
96	sav = isr->sav;
97	IPSEC_ASSERT(sav != NULL, ("null SA"));
98	IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
99
100	saidx = &sav->sah->saidx;
101	switch (saidx->dst.sa.sa_family) {
102#ifdef INET
103	case AF_INET:
104		/* Fix the header length, for AH processing. */
105		mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
106		break;
107#endif /* INET */
108#ifdef INET6
109	case AF_INET6:
110		/* Fix the header length, for AH processing. */
111		if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
112			error = ENXIO;
113			goto bad;
114		}
115		if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
116			/* No jumbogram support. */
117			error = ENXIO;	/*?*/
118			goto bad;
119		}
120		mtod(m, struct ip6_hdr *)->ip6_plen =
121			htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
122		break;
123#endif /* INET6 */
124	default:
125		DPRINTF(("%s: unknown protocol family %u\n", __func__,
126		    saidx->dst.sa.sa_family));
127		error = ENXIO;
128		goto bad;
129	}
130
131	/*
132	 * Add a record of what we've done or what needs to be done to the
133	 * packet.
134	 */
135	mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
136			sizeof(struct tdb_ident), M_NOWAIT);
137	if (mtag == NULL) {
138		DPRINTF(("%s: could not get packet tag\n", __func__));
139		error = ENOMEM;
140		goto bad;
141	}
142
143	tdbi = (struct tdb_ident *)(mtag + 1);
144	tdbi->dst = saidx->dst;
145	tdbi->proto = saidx->proto;
146	tdbi->spi = sav->spi;
147	m_tag_prepend(m, mtag);
148
149	/*
150	 * If there's another (bundled) SA to apply, do so.
151	 * Note that this puts a burden on the kernel stack size.
152	 * If this is a problem we'll need to introduce a queue
153	 * to set the packet on so we can unwind the stack before
154	 * doing further processing.
155	 */
156	if (isr->next) {
157		newipsecstat.ips_out_bundlesa++;
158		return ipsec4_process_packet(m, isr->next, 0, 0);
159	}
160	key_sa_recordxfer(sav, m);		/* record data transfer */
161
162	/*
163	 * We're done with IPsec processing, transmit the packet using the
164	 * appropriate network protocol (IP or IPv6). SPD lookup will be
165	 * performed again there.
166	 */
167	switch (saidx->dst.sa.sa_family) {
168#ifdef INET
169	struct ip *ip;
170	case AF_INET:
171		ip = mtod(m, struct ip *);
172		ip->ip_len = ntohs(ip->ip_len);
173		ip->ip_off = ntohs(ip->ip_off);
174
175		return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
176#endif /* INET */
177#ifdef INET6
178	case AF_INET6:
179		/*
180		 * We don't need massage, IPv6 header fields are always in
181		 * net endian.
182		 */
183		return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
184#endif /* INET6 */
185	}
186	panic("ipsec_process_done");
187bad:
188	m_freem(m);
189	KEY_FREESAV(&sav);
190	return (error);
191}
192
193static struct ipsecrequest *
194ipsec_nextisr(
195	struct mbuf *m,
196	struct ipsecrequest *isr,
197	int af,
198	struct secasindex *saidx,
199	int *error
200)
201{
202#define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \
203			    isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++)
204	struct secasvar *sav;
205
206	IPSEC_SPLASSERT_SOFTNET(__func__);
207	IPSECREQUEST_LOCK_ASSERT(isr);
208
209	IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
210		("invalid address family %u", af));
211again:
212	/*
213	 * Craft SA index to search for proper SA.  Note that
214	 * we only fillin unspecified SA peers for transport
215	 * mode; for tunnel mode they must already be filled in.
216	 */
217	*saidx = isr->saidx;
218	if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
219		/* Fillin unspecified SA peers only for transport mode */
220		if (af == AF_INET) {
221			struct sockaddr_in *sin;
222			struct ip *ip = mtod(m, struct ip *);
223
224			if (saidx->src.sa.sa_len == 0) {
225				sin = &saidx->src.sin;
226				sin->sin_len = sizeof(*sin);
227				sin->sin_family = AF_INET;
228				sin->sin_port = IPSEC_PORT_ANY;
229				sin->sin_addr = ip->ip_src;
230			}
231			if (saidx->dst.sa.sa_len == 0) {
232				sin = &saidx->dst.sin;
233				sin->sin_len = sizeof(*sin);
234				sin->sin_family = AF_INET;
235				sin->sin_port = IPSEC_PORT_ANY;
236				sin->sin_addr = ip->ip_dst;
237			}
238		} else {
239			struct sockaddr_in6 *sin6;
240			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
241
242			if (saidx->src.sin6.sin6_len == 0) {
243				sin6 = (struct sockaddr_in6 *)&saidx->src;
244				sin6->sin6_len = sizeof(*sin6);
245				sin6->sin6_family = AF_INET6;
246				sin6->sin6_port = IPSEC_PORT_ANY;
247				sin6->sin6_addr = ip6->ip6_src;
248				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
249					/* fix scope id for comparing SPD */
250					sin6->sin6_addr.s6_addr16[1] = 0;
251					sin6->sin6_scope_id =
252					    ntohs(ip6->ip6_src.s6_addr16[1]);
253				}
254			}
255			if (saidx->dst.sin6.sin6_len == 0) {
256				sin6 = (struct sockaddr_in6 *)&saidx->dst;
257				sin6->sin6_len = sizeof(*sin6);
258				sin6->sin6_family = AF_INET6;
259				sin6->sin6_port = IPSEC_PORT_ANY;
260				sin6->sin6_addr = ip6->ip6_dst;
261				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
262					/* fix scope id for comparing SPD */
263					sin6->sin6_addr.s6_addr16[1] = 0;
264					sin6->sin6_scope_id =
265					    ntohs(ip6->ip6_dst.s6_addr16[1]);
266				}
267			}
268		}
269	}
270
271	/*
272	 * Lookup SA and validate it.
273	 */
274	*error = key_checkrequest(isr, saidx);
275	if (*error != 0) {
276		/*
277		 * IPsec processing is required, but no SA found.
278		 * I assume that key_acquire() had been called
279		 * to get/establish the SA. Here I discard
280		 * this packet because it is responsibility for
281		 * upper layer to retransmit the packet.
282		 */
283		newipsecstat.ips_out_nosa++;
284		goto bad;
285	}
286	sav = isr->sav;
287	if (sav == NULL) {		/* XXX valid return */
288		IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
289			("no SA found, but required; level %u",
290			ipsec_get_reqlevel(isr)));
291		IPSECREQUEST_UNLOCK(isr);
292		isr = isr->next;
293		if (isr == NULL) {
294			/*XXXstatistic??*/
295			*error = EINVAL;		/*XXX*/
296			return isr;
297		}
298		IPSECREQUEST_LOCK(isr);
299		goto again;
300	}
301
302	/*
303	 * Check system global policy controls.
304	 */
305	if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
306	    (isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
307	    (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
308		DPRINTF(("%s: IPsec outbound packet dropped due"
309			" to policy (check your sysctls)\n", __func__));
310		IPSEC_OSTAT(espstat.esps_pdrops, ahstat.ahs_pdrops,
311		    ipcompstat.ipcomps_pdrops);
312		*error = EHOSTUNREACH;
313		goto bad;
314	}
315
316	/*
317	 * Sanity check the SA contents for the caller
318	 * before they invoke the xform output method.
319	 */
320	if (sav->tdb_xform == NULL) {
321		DPRINTF(("%s: no transform for SA\n", __func__));
322		IPSEC_OSTAT(espstat.esps_noxform, ahstat.ahs_noxform,
323		    ipcompstat.ipcomps_noxform);
324		*error = EHOSTUNREACH;
325		goto bad;
326	}
327	return isr;
328bad:
329	IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
330	IPSECREQUEST_UNLOCK(isr);
331	return NULL;
332#undef IPSEC_OSTAT
333}
334
335#ifdef INET
336/*
337 * IPsec output logic for IPv4.
338 */
339int
340ipsec4_process_packet(
341	struct mbuf *m,
342	struct ipsecrequest *isr,
343	int flags,
344	int tunalready)
345{
346	struct secasindex saidx;
347	struct secasvar *sav;
348	struct ip *ip;
349	int error, i, off;
350
351	IPSEC_ASSERT(m != NULL, ("null mbuf"));
352	IPSEC_ASSERT(isr != NULL, ("null isr"));
353
354	IPSECREQUEST_LOCK(isr);		/* insure SA contents don't change */
355
356	isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
357	if (isr == NULL)
358		goto bad;
359
360	sav = isr->sav;
361	if (!tunalready) {
362		union sockaddr_union *dst = &sav->sah->saidx.dst;
363		int setdf;
364
365		/*
366		 * Collect IP_DF state from the outer header.
367		 */
368		if (dst->sa.sa_family == AF_INET) {
369			if (m->m_len < sizeof (struct ip) &&
370			    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
371				error = ENOBUFS;
372				goto bad;
373			}
374			ip = mtod(m, struct ip *);
375			/* Honor system-wide control of how to handle IP_DF */
376			switch (ip4_ipsec_dfbit) {
377			case 0:			/* clear in outer header */
378			case 1:			/* set in outer header */
379				setdf = ip4_ipsec_dfbit;
380				break;
381			default:		/* propagate to outer header */
382				setdf = ntohs(ip->ip_off & IP_DF);
383				break;
384			}
385		} else {
386			ip = NULL;		/* keep compiler happy */
387			setdf = 0;
388		}
389		/* Do the appropriate encapsulation, if necessary */
390		if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
391		    dst->sa.sa_family != AF_INET ||	    /* PF mismatch */
392#if 0
393		    (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
394		    sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
395#endif
396		    (dst->sa.sa_family == AF_INET &&	    /* Proxy */
397		     dst->sin.sin_addr.s_addr != INADDR_ANY &&
398		     dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
399			struct mbuf *mp;
400
401			/* Fix IPv4 header checksum and length */
402			if (m->m_len < sizeof (struct ip) &&
403			    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
404				error = ENOBUFS;
405				goto bad;
406			}
407			ip = mtod(m, struct ip *);
408			ip->ip_len = htons(m->m_pkthdr.len);
409			ip->ip_sum = 0;
410#ifdef _IP_VHL
411			if (ip->ip_vhl == IP_VHL_BORING)
412				ip->ip_sum = in_cksum_hdr(ip);
413			else
414				ip->ip_sum = in_cksum(m,
415					_IP_VHL_HL(ip->ip_vhl) << 2);
416#else
417			ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
418#endif
419
420			/* Encapsulate the packet */
421			error = ipip_output(m, isr, &mp, 0, 0);
422			if (mp == NULL && !error) {
423				/* Should never happen. */
424				DPRINTF(("%s: ipip_output returns no mbuf and "
425					"no error!", __func__));
426				error = EFAULT;
427			}
428			if (error) {
429				if (mp) {
430					/* XXX: Should never happen! */
431					m_freem(mp);
432				}
433				m = NULL; /* ipip_output() already freed it */
434				goto bad;
435			}
436			m = mp, mp = NULL;
437			/*
438			 * ipip_output clears IP_DF in the new header.  If
439			 * we need to propagate IP_DF from the outer header,
440			 * then we have to do it here.
441			 *
442			 * XXX shouldn't assume what ipip_output does.
443			 */
444			if (dst->sa.sa_family == AF_INET && setdf) {
445				if (m->m_len < sizeof (struct ip) &&
446				    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
447					error = ENOBUFS;
448					goto bad;
449				}
450				ip = mtod(m, struct ip *);
451				ip->ip_off = ntohs(ip->ip_off);
452				ip->ip_off |= IP_DF;
453				ip->ip_off = htons(ip->ip_off);
454			}
455		}
456	}
457
458	/*
459	 * Dispatch to the appropriate IPsec transform logic.  The
460	 * packet will be returned for transmission after crypto
461	 * processing, etc. are completed.  For encapsulation we
462	 * bypass this call because of the explicit call done above
463	 * (necessary to deal with IP_DF handling for IPv4).
464	 *
465	 * NB: m & sav are ``passed to caller'' who's reponsible for
466	 *     for reclaiming their resources.
467	 */
468	if (sav->tdb_xform->xf_type != XF_IP4) {
469		ip = mtod(m, struct ip *);
470		i = ip->ip_hl << 2;
471		off = offsetof(struct ip, ip_p);
472		error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
473	} else {
474		error = ipsec_process_done(m, isr);
475	}
476	IPSECREQUEST_UNLOCK(isr);
477	return error;
478bad:
479	if (isr)
480		IPSECREQUEST_UNLOCK(isr);
481	if (m)
482		m_freem(m);
483	return error;
484}
485#endif
486
487#ifdef INET6
488/*
489 * Chop IP6 header from the payload.
490 */
491static struct mbuf *
492ipsec6_splithdr(struct mbuf *m)
493{
494	struct mbuf *mh;
495	struct ip6_hdr *ip6;
496	int hlen;
497
498	IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
499		("first mbuf too short, len %u", m->m_len));
500	ip6 = mtod(m, struct ip6_hdr *);
501	hlen = sizeof(struct ip6_hdr);
502	if (m->m_len > hlen) {
503		MGETHDR(mh, M_DONTWAIT, MT_DATA);
504		if (!mh) {
505			m_freem(m);
506			return NULL;
507		}
508		M_MOVE_PKTHDR(mh, m);
509		MH_ALIGN(mh, hlen);
510		m->m_len -= hlen;
511		m->m_data += hlen;
512		mh->m_next = m;
513		m = mh;
514		m->m_len = hlen;
515		bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
516	} else if (m->m_len < hlen) {
517		m = m_pullup(m, hlen);
518		if (!m)
519			return NULL;
520	}
521	return m;
522}
523
524/*
525 * IPsec output logic for IPv6, transport mode.
526 */
527int
528ipsec6_output_trans(
529	struct ipsec_output_state *state,
530	u_char *nexthdrp,
531	struct mbuf *mprev,
532	struct secpolicy *sp,
533	int flags,
534	int *tun)
535{
536	struct ipsecrequest *isr;
537	struct secasindex saidx;
538	int error = 0;
539	struct mbuf *m;
540
541	IPSEC_ASSERT(state != NULL, ("null state"));
542	IPSEC_ASSERT(state->m != NULL, ("null m"));
543	IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
544	IPSEC_ASSERT(mprev != NULL, ("null mprev"));
545	IPSEC_ASSERT(sp != NULL, ("null sp"));
546	IPSEC_ASSERT(tun != NULL, ("null tun"));
547
548	KEYDEBUG(KEYDEBUG_IPSEC_DATA,
549		printf("%s: applyed SP\n", __func__);
550		kdebug_secpolicy(sp));
551
552	isr = sp->req;
553	if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
554		/* the rest will be handled by ipsec6_output_tunnel() */
555		*tun = 1;		/* need tunnel-mode processing */
556		return 0;
557	}
558
559	*tun = 0;
560	m = state->m;
561
562	isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
563	if (isr == NULL) {
564#ifdef notdef
565		/* XXX should notification be done for all errors ? */
566		/*
567		 * Notify the fact that the packet is discarded
568		 * to ourselves. I believe this is better than
569		 * just silently discarding. (jinmei@kame.net)
570		 * XXX: should we restrict the error to TCP packets?
571		 * XXX: should we directly notify sockets via
572		 *      pfctlinputs?
573		 */
574		icmp6_error(m, ICMP6_DST_UNREACH,
575			    ICMP6_DST_UNREACH_ADMIN, 0);
576		m = NULL;	/* NB: icmp6_error frees mbuf */
577#endif
578		goto bad;
579	}
580
581	return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
582		sizeof (struct ip6_hdr),
583		offsetof(struct ip6_hdr, ip6_nxt));
584bad:
585	if (m)
586		m_freem(m);
587	state->m = NULL;
588	return error;
589}
590
591static int
592ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
593{
594	struct ip6_hdr *oip6;
595	struct ip6_hdr *ip6;
596	size_t plen;
597
598	/* can't tunnel between different AFs */
599	if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
600	    sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
601		m_freem(m);
602		return EINVAL;
603	}
604	IPSEC_ASSERT(m->m_len != sizeof (struct ip6_hdr),
605		("mbuf wrong size; len %u", m->m_len));
606
607
608	/*
609	 * grow the mbuf to accomodate the new IPv6 header.
610	 */
611	plen = m->m_pkthdr.len;
612	if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
613		struct mbuf *n;
614		MGET(n, M_DONTWAIT, MT_DATA);
615		if (!n) {
616			m_freem(m);
617			return ENOBUFS;
618		}
619		n->m_len = sizeof(struct ip6_hdr);
620		n->m_next = m->m_next;
621		m->m_next = n;
622		m->m_pkthdr.len += sizeof(struct ip6_hdr);
623		oip6 = mtod(n, struct ip6_hdr *);
624	} else {
625		m->m_next->m_len += sizeof(struct ip6_hdr);
626		m->m_next->m_data -= sizeof(struct ip6_hdr);
627		m->m_pkthdr.len += sizeof(struct ip6_hdr);
628		oip6 = mtod(m->m_next, struct ip6_hdr *);
629	}
630	ip6 = mtod(m, struct ip6_hdr *);
631	bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
632
633	/* Fake link-local scope-class addresses */
634	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
635		oip6->ip6_src.s6_addr16[1] = 0;
636	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
637		oip6->ip6_dst.s6_addr16[1] = 0;
638
639	/* construct new IPv6 header. see RFC 2401 5.1.2.2 */
640	/* ECN consideration. */
641	ip6_ecn_ingress(ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
642	if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
643		ip6->ip6_plen = htons(plen);
644	else {
645		/* ip6->ip6_plen will be updated in ip6_output() */
646	}
647	ip6->ip6_nxt = IPPROTO_IPV6;
648	sav->sah->saidx.src.sin6.sin6_addr = ip6->ip6_src;
649	sav->sah->saidx.dst.sin6.sin6_addr = ip6->ip6_dst;
650	ip6->ip6_hlim = IPV6_DEFHLIM;
651
652	/* XXX Should ip6_src be updated later ? */
653
654	return 0;
655}
656
657/*
658 * IPsec output logic for IPv6, tunnel mode.
659 */
660int
661ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
662{
663	struct ip6_hdr *ip6;
664	struct ipsecrequest *isr;
665	struct secasindex saidx;
666	int error;
667	struct sockaddr_in6* dst6;
668	struct mbuf *m;
669
670	IPSEC_ASSERT(state != NULL, ("null state"));
671	IPSEC_ASSERT(state->m != NULL, ("null m"));
672	IPSEC_ASSERT(sp != NULL, ("null sp"));
673
674	KEYDEBUG(KEYDEBUG_IPSEC_DATA,
675		printf("%s: applyed SP\n", __func__);
676		kdebug_secpolicy(sp));
677
678	m = state->m;
679	/*
680	 * transport mode ipsec (before the 1st tunnel mode) is already
681	 * processed by ipsec6_output_trans().
682	 */
683	for (isr = sp->req; isr; isr = isr->next) {
684		if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
685			break;
686	}
687	isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
688	if (isr == NULL)
689		goto bad;
690
691	/*
692	 * There may be the case that SA status will be changed when
693	 * we are refering to one. So calling splsoftnet().
694	 */
695	if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
696		/*
697		 * build IPsec tunnel.
698		 */
699		/* XXX should be processed with other familiy */
700		if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
701			ipseclog((LOG_ERR, "%s: family mismatched between "
702			    "inner and outer, spi=%u\n", __func__,
703			    ntohl(isr->sav->spi)));
704			newipsecstat.ips_out_inval++;
705			error = EAFNOSUPPORT;
706			goto bad;
707		}
708
709		m = ipsec6_splithdr(m);
710		if (!m) {
711			newipsecstat.ips_out_nomem++;
712			error = ENOMEM;
713			goto bad;
714		}
715		error = ipsec6_encapsulate(m, isr->sav);
716		if (error) {
717			m = NULL;
718			goto bad;
719		}
720		ip6 = mtod(m, struct ip6_hdr *);
721
722		state->ro = &isr->sav->sah->sa_route;
723		state->dst = (struct sockaddr *)&state->ro->ro_dst;
724		dst6 = (struct sockaddr_in6 *)state->dst;
725		if (state->ro->ro_rt
726		 && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
727		  || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
728			RTFREE(state->ro->ro_rt);
729			state->ro->ro_rt = NULL;
730		}
731		if (state->ro->ro_rt == 0) {
732			bzero(dst6, sizeof(*dst6));
733			dst6->sin6_family = AF_INET6;
734			dst6->sin6_len = sizeof(*dst6);
735			dst6->sin6_addr = ip6->ip6_dst;
736			rtalloc(state->ro);
737		}
738		if (state->ro->ro_rt == 0) {
739			ip6stat.ip6s_noroute++;
740			newipsecstat.ips_out_noroute++;
741			error = EHOSTUNREACH;
742			goto bad;
743		}
744
745		/* adjust state->dst if tunnel endpoint is offlink */
746		if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) {
747			state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
748			dst6 = (struct sockaddr_in6 *)state->dst;
749		}
750	}
751
752	m = ipsec6_splithdr(m);
753	if (!m) {
754		newipsecstat.ips_out_nomem++;
755		error = ENOMEM;
756		goto bad;
757	}
758	ip6 = mtod(m, struct ip6_hdr *);
759	return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
760		sizeof (struct ip6_hdr),
761		offsetof(struct ip6_hdr, ip6_nxt));
762bad:
763	if (m)
764		m_freem(m);
765	state->m = NULL;
766	return error;
767}
768#endif /*INET6*/
769