xref: /netbsd-src/sys/netipsec/ipsec_output.c (revision daf6c4152fcddc27c445489775ed1f66ab4ea9a9)
1 /*	$NetBSD: ipsec_output.c,v 1.31 2011/02/10 20:42:30 drochner Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD: /repoman/r/ncvs/src/sys/netipsec/ipsec_output.c,v 1.3.2.2 2003/03/28 20:32:53 sam Exp $
29  */
30 
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: ipsec_output.c,v 1.31 2011/02/10 20:42:30 drochner Exp $");
33 
34 /*
35  * IPsec output processing.
36  */
37 #include "opt_inet.h"
38 #ifdef __FreeBSD__
39 #include "opt_inet6.h"
40 #endif
41 #include "opt_ipsec.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/mbuf.h>
46 #include <sys/domain.h>
47 #include <sys/protosw.h>
48 #include <sys/socket.h>
49 #include <sys/errno.h>
50 #include <sys/syslog.h>
51 
52 #include <net/if.h>
53 #include <net/route.h>
54 
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_var.h>
59 #include <netinet/in_var.h>
60 #include <netinet/ip_ecn.h>
61 #ifdef INET6
62 #  ifdef __FreeBSD__
63 #  include <netinet6/ip6_ecn.h>
64 #  endif
65 #endif
66 
67 #include <netinet/ip6.h>
68 #ifdef INET6
69 #include <netinet6/ip6_var.h>
70 #endif
71 #include <netinet/in_pcb.h>
72 #ifdef INET6
73 #include <netinet/icmp6.h>
74 #endif
75 #ifdef IPSEC_NAT_T
76 #include <netinet/udp.h>
77 #endif
78 
79 #include <netipsec/ipsec.h>
80 #include <netipsec/ipsec_var.h>
81 #include <netipsec/ipsec_private.h>
82 #ifdef INET6
83 #include <netipsec/ipsec6.h>
84 #endif
85 #include <netipsec/ah_var.h>
86 #include <netipsec/esp_var.h>
87 #include <netipsec/ipcomp_var.h>
88 
89 #include <netipsec/xform.h>
90 
91 #include <netipsec/key.h>
92 #include <netipsec/keydb.h>
93 #include <netipsec/key_debug.h>
94 #include <netipsec/ipsec_osdep.h>
95 
96 #include <net/net_osdep.h>		/* ovbcopy() in ipsec6_encapsulate() */
97 
98 
99 /*
100  * Add a IPSEC_OUT_DONE tag to mark that we have finished the ipsec processing
101  * It will be used by ip{,6}_output to check if we have already or not
102  * processed this packet.
103  */
104 static int
105 ipsec_register_done(struct mbuf *m, int * error)
106 {
107 	struct m_tag *mtag;
108 
109 	mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, 0, M_NOWAIT);
110 	if (mtag == NULL) {
111 		DPRINTF(("ipsec_register_done: could not get packet tag\n"));
112 		*error = ENOMEM;
113 		return -1;
114 	}
115 
116 	m_tag_prepend(m, mtag);
117 	return 0;
118 }
119 
120 static int
121 ipsec_reinject_ipstack(struct mbuf *m, int af)
122 {
123 #ifdef INET
124 	struct ip * ip;
125 #endif /* INET */
126 #if defined(INET) || defined(INET6)
127 	int rv;
128 #endif
129 
130 	switch (af) {
131 #ifdef INET
132 	case AF_INET:
133 		ip = mtod(m, struct ip *);
134 #ifdef __FreeBSD__
135 		/* FreeBSD ip_output() expects ip_len, ip_off in host endian */
136 		ip->ip_len = ntohs(ip->ip_len);
137 		ip->ip_off = ntohs(ip->ip_off);
138 #endif /* __FreeBSD_ */
139 		KERNEL_LOCK(1, NULL);
140 		rv = ip_output(m, NULL, NULL, IP_RAWOUTPUT|IP_NOIPNEWID,
141 		    (struct ip_moptions *)NULL, (struct socket *)NULL);
142 		KERNEL_UNLOCK_ONE(NULL);
143 		return rv;
144 
145 #endif /* INET */
146 #ifdef INET6
147 	case AF_INET6:
148 		/*
149 		 * We don't need massage, IPv6 header fields are always in
150 		 * net endian.
151 		 */
152 		KERNEL_LOCK(1, NULL);
153 		rv = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
154 		KERNEL_UNLOCK_ONE(NULL);
155 		return rv;
156 #endif /* INET6 */
157 	}
158 
159 	panic("ipsec_reinject_ipstack : iunknown protocol family %u\n", af);
160 	return -1; /* NOTREACHED */
161 }
162 
163 int
164 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
165 {
166 	struct secasvar *sav;
167 	struct secasindex *saidx;
168 	int error;
169 #ifdef INET
170 	struct ip * ip;
171 #endif /* INET */
172 #ifdef INET6
173 	struct ip6_hdr * ip6;
174 #endif /* INET6 */
175 #ifdef IPSEC_NAT_T
176 	struct mbuf * mo;
177 	struct udphdr *udp = NULL;
178 	uint64_t * data = NULL;
179 	int hlen, roff;
180 #endif /* IPSEC_NAT_T */
181 
182 	IPSEC_SPLASSERT_SOFTNET("ipsec_process_done");
183 
184 	IPSEC_ASSERT(m != NULL, ("ipsec_process_done: null mbuf"));
185 	IPSEC_ASSERT(isr != NULL, ("ipsec_process_done: null ISR"));
186 	sav = isr->sav;
187 	IPSEC_ASSERT(sav != NULL, ("ipsec_process_done: null SA"));
188 	IPSEC_ASSERT(sav->sah != NULL, ("ipsec_process_done: null SAH"));
189 
190 	saidx = &sav->sah->saidx;
191 
192 #ifdef IPSEC_NAT_T
193 	if(sav->natt_type != 0) {
194 		ip = mtod(m, struct ip *);
195 
196 		hlen = sizeof(struct udphdr);
197 		if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
198 			hlen += sizeof(uint64_t);
199 
200 		mo = m_makespace(m, sizeof(struct ip), hlen, &roff);
201 		if (mo == NULL) {
202 			DPRINTF(("ipsec_process_done : failed to inject"
203 				 "%u byte UDP for SA %s/%08lx\n",
204 					 hlen, ipsec_address(&saidx->dst),
205 					 (u_long) ntohl(sav->spi)));
206 			error = ENOBUFS;
207 			goto bad;
208 		}
209 
210 		udp = (struct udphdr*) (mtod(mo, char*) + roff);
211 		data = (uint64_t*) (udp + 1);
212 
213 		if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
214 			*data = 0; /* NON-IKE Marker */
215 
216 		if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
217 			udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
218 		else
219 			udp->uh_sport = key_portfromsaddr(&saidx->src);
220 
221 		udp->uh_dport = key_portfromsaddr(&saidx->dst);
222 		udp->uh_sum = 0;
223 		udp->uh_ulen = htons(m->m_pkthdr.len - (ip->ip_hl << 2));
224 	}
225 #endif /* IPSEC_NAT_T */
226 
227 	switch (saidx->dst.sa.sa_family) {
228 #ifdef INET
229 	case AF_INET:
230 		/* Fix the header length, for AH processing. */
231 		ip = mtod(m, struct ip *);
232 		ip->ip_len = htons(m->m_pkthdr.len);
233 #ifdef IPSEC_NAT_T
234 		if (sav->natt_type != 0)
235 			ip->ip_p = IPPROTO_UDP;
236 #endif /* IPSEC_NAT_T */
237 		break;
238 #endif /* INET */
239 #ifdef INET6
240 	case AF_INET6:
241 		/* Fix the header length, for AH processing. */
242 		if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
243 			error = ENXIO;
244 			goto bad;
245 		}
246 		if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
247 			/* No jumbogram support. */
248 			error = ENXIO;	/*?*/
249 			goto bad;
250 		}
251 		ip6 = mtod(m, struct ip6_hdr *);
252 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
253 #ifdef IPSEC_NAT_T
254 		if (sav->natt_type != 0)
255 			ip6->ip6_nxt = IPPROTO_UDP;
256 #endif /* IPSEC_NAT_T */
257 		break;
258 #endif /* INET6 */
259 	default:
260 		DPRINTF(("ipsec_process_done: unknown protocol family %u\n",
261 		    saidx->dst.sa.sa_family));
262 		error = ENXIO;
263 		goto bad;
264 	}
265 
266 	/*
267 	 * If there's another (bundled) SA to apply, do so.
268 	 * Note that this puts a burden on the kernel stack size.
269 	 * If this is a problem we'll need to introduce a queue
270 	 * to set the packet on so we can unwind the stack before
271 	 * doing further processing.
272 	 */
273 	if (isr->next) {
274 		IPSEC_STATINC(IPSEC_STAT_OUT_BUNDLESA);
275 		switch ( saidx->dst.sa.sa_family ) {
276 #ifdef INET
277 		case AF_INET:
278 			return ipsec4_process_packet(m, isr->next, 0,0);
279 #endif /* INET */
280 #ifdef INET6
281 		case AF_INET6:
282 			return ipsec6_process_packet(m,isr->next);
283 #endif /* INET6 */
284 		default :
285 			DPRINTF(("ipsec_process_done: unknown protocol family %u\n",
286 			       saidx->dst.sa.sa_family));
287 			error = ENXIO;
288 			goto bad;
289 		}
290 	}
291 
292 	/*
293 	 * We're done with IPsec processing,
294 	 * mark that we have already processed the packet
295 	 * transmit it packet using the appropriate network protocol (IP or IPv6).
296 	 */
297 
298 	if (ipsec_register_done(m, &error) < 0)
299 		goto bad;
300 
301 	return ipsec_reinject_ipstack(m, saidx->dst.sa.sa_family);
302 bad:
303 	m_freem(m);
304 	KEY_FREESAV(&sav);
305 	return (error);
306 }
307 
308 /*
309  * ipsec_nextisr can return :
310  * - isr == NULL and error != 0 => something is bad : the packet must be
311  *   discarded
312  * - isr == NULL and error == 0 => no more rules to apply, ipsec processing
313  *   is done, reinject it in ip stack
314  * - isr != NULL (error == 0) => we need to apply one rule to the packet
315  */
316 static struct ipsecrequest *
317 ipsec_nextisr(
318 	struct mbuf *m,
319 	struct ipsecrequest *isr,
320 	int af,
321 	struct secasindex *saidx,
322 	int *error
323 )
324 {
325 #define	IPSEC_OSTAT(x, y, z)						\
326 do {									\
327 	switch (isr->saidx.proto) {					\
328 	case IPPROTO_ESP:						\
329 		ESP_STATINC(x);						\
330 		break;							\
331 	case IPPROTO_AH:						\
332 		AH_STATINC(y);						\
333 		break;							\
334 	default:							\
335 		IPCOMP_STATINC(z);					\
336 		break;							\
337 	}								\
338 } while (/*CONSTCOND*/0)
339 
340 	struct secasvar *sav;
341 
342 	IPSEC_SPLASSERT_SOFTNET("ipsec_nextisr");
343 	IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
344 		("ipsec_nextisr: invalid address family %u", af));
345 again:
346 	/*
347 	 * Craft SA index to search for proper SA.  Note that
348 	 * we only fillin unspecified SA peers for transport
349 	 * mode; for tunnel mode they must already be filled in.
350 	 */
351 	*saidx = isr->saidx;
352 	if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
353 		/* Fillin unspecified SA peers only for transport mode */
354 		if (af == AF_INET) {
355 			struct sockaddr_in *sin;
356 			struct ip *ip = mtod(m, struct ip *);
357 
358 			if (saidx->src.sa.sa_len == 0) {
359 				sin = &saidx->src.sin;
360 				sin->sin_len = sizeof(*sin);
361 				sin->sin_family = AF_INET;
362 				sin->sin_port = IPSEC_PORT_ANY;
363 				sin->sin_addr = ip->ip_src;
364 			}
365 			if (saidx->dst.sa.sa_len == 0) {
366 				sin = &saidx->dst.sin;
367 				sin->sin_len = sizeof(*sin);
368 				sin->sin_family = AF_INET;
369 				sin->sin_port = IPSEC_PORT_ANY;
370 				sin->sin_addr = ip->ip_dst;
371 			}
372 		} else {
373 			struct sockaddr_in6 *sin6;
374 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
375 
376 			if (saidx->src.sin6.sin6_len == 0) {
377 				sin6 = (struct sockaddr_in6 *)&saidx->src;
378 				sin6->sin6_len = sizeof(*sin6);
379 				sin6->sin6_family = AF_INET6;
380 				sin6->sin6_port = IPSEC_PORT_ANY;
381 				sin6->sin6_addr = ip6->ip6_src;
382 				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
383 					/* fix scope id for comparing SPD */
384 					sin6->sin6_addr.s6_addr16[1] = 0;
385 					sin6->sin6_scope_id =
386 					    ntohs(ip6->ip6_src.s6_addr16[1]);
387 				}
388 			}
389 			if (saidx->dst.sin6.sin6_len == 0) {
390 				sin6 = (struct sockaddr_in6 *)&saidx->dst;
391 				sin6->sin6_len = sizeof(*sin6);
392 				sin6->sin6_family = AF_INET6;
393 				sin6->sin6_port = IPSEC_PORT_ANY;
394 				sin6->sin6_addr = ip6->ip6_dst;
395 				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
396 					/* fix scope id for comparing SPD */
397 					sin6->sin6_addr.s6_addr16[1] = 0;
398 					sin6->sin6_scope_id =
399 					    ntohs(ip6->ip6_dst.s6_addr16[1]);
400 				}
401 			}
402 		}
403 	}
404 
405 	/*
406 	 * Lookup SA and validate it.
407 	 */
408 	*error = key_checkrequest(isr, saidx);
409 	if (*error != 0) {
410 		/*
411 		 * IPsec processing is required, but no SA found.
412 		 * I assume that key_acquire() had been called
413 		 * to get/establish the SA. Here I discard
414 		 * this packet because it is responsibility for
415 		 * upper layer to retransmit the packet.
416 		 */
417 		IPSEC_STATINC(IPSEC_STAT_OUT_NOSA);
418 		goto bad;
419 	}
420 	sav = isr->sav;
421 	/* sav may be NULL here if we have an USE rule */
422 	if (sav == NULL) {
423 		IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
424 			("ipsec_nextisr: no SA found, but required; level %u",
425 			ipsec_get_reqlevel(isr)));
426 		isr = isr->next;
427 		/*
428 		 * No more rules to apply, return NULL isr and no error
429 		 * It can happen when the last rules are USE rules
430 		 * */
431 		if (isr == NULL) {
432 			*error = 0;
433 			return isr;
434 		}
435 		goto again;
436 	}
437 
438 	/*
439 	 * Check system global policy controls.
440 	 */
441 	if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
442 	    (isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
443 	    (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
444 		DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due"
445 			" to policy (check your sysctls)\n"));
446 		IPSEC_OSTAT(ESP_STAT_PDROPS, AH_STAT_PDROPS,
447 		    IPCOMP_STAT_PDROPS);
448 		*error = EHOSTUNREACH;
449 		goto bad;
450 	}
451 
452 	/*
453 	 * Sanity check the SA contents for the caller
454 	 * before they invoke the xform output method.
455 	 */
456 	if (sav->tdb_xform == NULL) {
457 		DPRINTF(("ipsec_nextisr: no transform for SA\n"));
458 		IPSEC_OSTAT(ESP_STAT_NOXFORM, AH_STAT_NOXFORM,
459 		    IPCOMP_STAT_NOXFORM);
460 		*error = EHOSTUNREACH;
461 		goto bad;
462 	}
463 	return isr;
464 bad:
465 	IPSEC_ASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code"));
466 	return NULL;
467 #undef IPSEC_OSTAT
468 }
469 
470 #ifdef INET
471 /*
472  * IPsec output logic for IPv4.
473  */
474 int
475 ipsec4_process_packet(
476     struct mbuf *m,
477     struct ipsecrequest *isr,
478     int flags,
479     int tunalready
480 )
481 {
482 	struct secasindex saidx;
483 	struct secasvar *sav;
484 	struct ip *ip;
485 	int s, error, i, off;
486 
487 	IPSEC_ASSERT(m != NULL, ("ipsec4_process_packet: null mbuf"));
488 	IPSEC_ASSERT(isr != NULL, ("ipsec4_process_packet: null isr"));
489 
490 	s = splsoftnet();			/* insure SA contents don't change */
491 
492 	isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
493 	if (isr == NULL) {
494 		if (error != 0) {
495 			goto bad;
496 		} else {
497 			if (ipsec_register_done(m, &error) < 0)
498 				goto bad;
499 
500 			splx(s);
501 			return ipsec_reinject_ipstack(m, AF_INET);
502 		}
503 	}
504 
505 	sav = isr->sav;
506 	if (!tunalready) {
507 		union sockaddr_union *dst = &sav->sah->saidx.dst;
508 		int setdf;
509 
510 		/*
511 		 * Collect IP_DF state from the outer header.
512 		 */
513 		if (dst->sa.sa_family == AF_INET) {
514 			if (m->m_len < sizeof (struct ip) &&
515 			    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
516 				error = ENOBUFS;
517 				goto bad;
518 			}
519 			ip = mtod(m, struct ip *);
520 			/* Honor system-wide control of how to handle IP_DF */
521 			switch (ip4_ipsec_dfbit) {
522 			case 0:			/* clear in outer header */
523 			case 1:			/* set in outer header */
524 				setdf = ip4_ipsec_dfbit;
525 				break;
526 			default:		/* propagate to outer header */
527 				setdf = ip->ip_off;
528 #ifndef __FreeBSD__
529 		/* On FreeBSD, ip_off and ip_len assumed in host endian. */
530 				setdf = ntohs(setdf);
531 #endif
532 				setdf = htons(setdf & IP_DF);
533 				break;
534 			}
535 		} else {
536 			ip = NULL;		/* keep compiler happy */
537 			setdf = 0;
538 		}
539 		/* Do the appropriate encapsulation, if necessary */
540 		if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
541 		    dst->sa.sa_family != AF_INET ||	    /* PF mismatch */
542 #if 0
543 		    (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
544 		    sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
545 #endif
546 		    (dst->sa.sa_family == AF_INET &&	    /* Proxy */
547 		     dst->sin.sin_addr.s_addr != INADDR_ANY &&
548 		     dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
549 			struct mbuf *mp;
550 
551 			/* Fix IPv4 header checksum and length */
552 			if (m->m_len < sizeof (struct ip) &&
553 			    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
554 				error = ENOBUFS;
555 				goto bad;
556 			}
557 			ip = mtod(m, struct ip *);
558 			ip->ip_len = htons(m->m_pkthdr.len);
559 			ip->ip_sum = 0;
560 			ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
561 
562 			/* Encapsulate the packet */
563 			error = ipip_output(m, isr, &mp, 0, 0);
564 			if (mp == NULL && !error) {
565 				/* Should never happen. */
566 				DPRINTF(("ipsec4_process_packet: ipip_output "
567 					"returns no mbuf and no error!"));
568 				error = EFAULT;
569 			}
570 			if (error) {
571 				if (mp) {
572 					/* XXX: Should never happen! */
573 					m_freem(mp);
574 				}
575 				m = NULL; /* ipip_output() already freed it */
576 				goto bad;
577 			}
578 			m = mp, mp = NULL;
579 			/*
580 			 * ipip_output clears IP_DF in the new header.  If
581 			 * we need to propagate IP_DF from the outer header,
582 			 * then we have to do it here.
583 			 *
584 			 * XXX shouldn't assume what ipip_output does.
585 			 */
586 			if (dst->sa.sa_family == AF_INET && setdf) {
587 				if (m->m_len < sizeof (struct ip) &&
588 				    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
589 					error = ENOBUFS;
590 					goto bad;
591 				}
592 				ip = mtod(m, struct ip *);
593 				ip->ip_off |= IP_OFF_CONVERT(IP_DF);
594 			}
595 		}
596 	}
597 
598 	/*
599 	 * Dispatch to the appropriate IPsec transform logic.  The
600 	 * packet will be returned for transmission after crypto
601 	 * processing, etc. are completed.  For encapsulation we
602 	 * bypass this call because of the explicit call done above
603 	 * (necessary to deal with IP_DF handling for IPv4).
604 	 *
605 	 * NB: m & sav are ``passed to caller'' who's reponsible for
606 	 *     for reclaiming their resources.
607 	 */
608 	if (sav->tdb_xform->xf_type != XF_IP4) {
609 		ip = mtod(m, struct ip *);
610 		i = ip->ip_hl << 2;
611 		off = offsetof(struct ip, ip_p);
612 		error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
613 	} else {
614 		error = ipsec_process_done(m, isr);
615 	}
616 	splx(s);
617 	return error;
618 bad:
619 	splx(s);
620 	if (m)
621 		m_freem(m);
622 	return error;
623 }
624 #endif
625 
626 #ifdef INET6
627 int
628 ipsec6_process_packet(
629 	struct mbuf *m,
630  	struct ipsecrequest *isr
631     )
632 {
633 	struct secasindex saidx;
634 	struct secasvar *sav;
635 	struct ip6_hdr *ip6;
636 	int s, error, i, off;
637 
638 	IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf"));
639 	IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr"));
640 
641 	s = splsoftnet();   /* insure SA contents don't change */
642 	isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
643 	if (isr == NULL) {
644 		if (error != 0) {
645 			// XXX Should we send a notification ?
646 			goto bad;
647 		} else {
648 			if (ipsec_register_done(m, &error) < 0)
649 				goto bad;
650 
651 			splx(s);
652 			return ipsec_reinject_ipstack(m, AF_INET6);
653 		}
654 	}
655 
656 	sav = isr->sav;
657 	if (sav->tdb_xform->xf_type != XF_IP4) {
658 		i = sizeof(struct ip6_hdr);
659 		off = offsetof(struct ip6_hdr, ip6_nxt);
660 		error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
661        } else {
662 		union sockaddr_union *dst = &sav->sah->saidx.dst;
663 
664         ip6 = mtod(m, struct ip6_hdr *);
665 
666 		/* Do the appropriate encapsulation, if necessary */
667 		if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
668                dst->sa.sa_family != AF_INET6 ||        /* PF mismatch */
669             ((dst->sa.sa_family == AF_INET6) &&
670                 (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) &&
671                 (!IN6_ARE_ADDR_EQUAL(&dst->sin6.sin6_addr,
672                 &ip6->ip6_dst)))
673             )
674 		{
675 			struct mbuf *mp;
676             /* Fix IPv6 header payload length. */
677             if (m->m_len < sizeof(struct ip6_hdr))
678                 if ((m = m_pullup(m,sizeof(struct ip6_hdr))) == NULL)
679                    return ENOBUFS;
680 
681             if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) {
682                 /* No jumbogram support. */
683                 m_freem(m);
684                 return ENXIO;   /*XXX*/
685             }
686             ip6 = mtod(m, struct ip6_hdr *);
687             ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
688 
689 			/* Encapsulate the packet */
690 			error = ipip_output(m, isr, &mp, 0, 0);
691 			if (mp == NULL && !error) {
692 				/* Should never happen. */
693 				DPRINTF(("ipsec6_process_packet: ipip_output "
694 						 "returns no mbuf and no error!"));
695 				 error = EFAULT;
696 			}
697 
698 			if (error) {
699 				if (mp) {
700 					/* XXX: Should never happen! */
701 					m_freem(mp);
702 				}
703 				m = NULL; /* ipip_output() already freed it */
704 				goto bad;
705 			}
706 
707 			m = mp;
708 			mp = NULL;
709 		}
710 
711 		error = ipsec_process_done(m,isr);
712 		}
713 		splx(s);
714 		return error;
715 bad:
716 	splx(s);
717 	if (m)
718 		m_freem(m);
719 	return error;
720 }
721 #endif /*INET6*/
722