xref: /freebsd/sys/netipsec/ipsec_output.c (revision 3823d5e198425b4f5e5a80267d195769d1063773)
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/if_var.h>
48 #include <net/pfil.h>
49 #include <net/route.h>
50 #include <net/vnet.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #include <netinet/ip_var.h>
56 #include <netinet/in_var.h>
57 #include <netinet/ip_ecn.h>
58 #ifdef INET6
59 #include <netinet6/ip6_ecn.h>
60 #endif
61 
62 #include <netinet/ip6.h>
63 #ifdef INET6
64 #include <netinet6/ip6_var.h>
65 #endif
66 #include <netinet/in_pcb.h>
67 #ifdef INET6
68 #include <netinet/icmp6.h>
69 #endif
70 
71 #include <netipsec/ipsec.h>
72 #ifdef INET6
73 #include <netipsec/ipsec6.h>
74 #endif
75 #include <netipsec/ah_var.h>
76 #include <netipsec/esp_var.h>
77 #include <netipsec/ipcomp_var.h>
78 
79 #include <netipsec/xform.h>
80 
81 #include <netipsec/key.h>
82 #include <netipsec/keydb.h>
83 #include <netipsec/key_debug.h>
84 
85 #include <machine/in_cksum.h>
86 
87 #ifdef IPSEC_NAT_T
88 #include <netinet/udp.h>
89 #endif
90 
91 #ifdef DEV_ENC
92 #include <net/if_enc.h>
93 #endif
94 
95 
96 int
97 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
98 {
99 	struct tdb_ident *tdbi;
100 	struct m_tag *mtag;
101 	struct secasvar *sav;
102 	struct secasindex *saidx;
103 	int error;
104 
105 	IPSEC_ASSERT(m != NULL, ("null mbuf"));
106 	IPSEC_ASSERT(isr != NULL, ("null ISR"));
107 	sav = isr->sav;
108 	IPSEC_ASSERT(sav != NULL, ("null SA"));
109 	IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
110 
111 	saidx = &sav->sah->saidx;
112 	switch (saidx->dst.sa.sa_family) {
113 #ifdef INET
114 	case AF_INET:
115 		/* Fix the header length, for AH processing. */
116 		mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
117 		break;
118 #endif /* INET */
119 #ifdef INET6
120 	case AF_INET6:
121 		/* Fix the header length, for AH processing. */
122 		if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
123 			error = ENXIO;
124 			goto bad;
125 		}
126 		if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
127 			/* No jumbogram support. */
128 			error = ENXIO;	/*?*/
129 			goto bad;
130 		}
131 		mtod(m, struct ip6_hdr *)->ip6_plen =
132 			htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
133 		break;
134 #endif /* INET6 */
135 	default:
136 		DPRINTF(("%s: unknown protocol family %u\n", __func__,
137 		    saidx->dst.sa.sa_family));
138 		error = ENXIO;
139 		goto bad;
140 	}
141 
142 	/*
143 	 * Add a record of what we've done or what needs to be done to the
144 	 * packet.
145 	 */
146 	mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
147 			sizeof(struct tdb_ident), M_NOWAIT);
148 	if (mtag == NULL) {
149 		DPRINTF(("%s: could not get packet tag\n", __func__));
150 		error = ENOMEM;
151 		goto bad;
152 	}
153 
154 	tdbi = (struct tdb_ident *)(mtag + 1);
155 	tdbi->dst = saidx->dst;
156 	tdbi->proto = saidx->proto;
157 	tdbi->spi = sav->spi;
158 	m_tag_prepend(m, mtag);
159 
160 	/*
161 	 * If there's another (bundled) SA to apply, do so.
162 	 * Note that this puts a burden on the kernel stack size.
163 	 * If this is a problem we'll need to introduce a queue
164 	 * to set the packet on so we can unwind the stack before
165 	 * doing further processing.
166 	 */
167 	if (isr->next) {
168 		IPSECSTAT_INC(ips_out_bundlesa);
169 		/* XXX-BZ currently only support same AF bundles. */
170 		switch (saidx->dst.sa.sa_family) {
171 #ifdef INET
172 		case AF_INET:
173 			return ipsec4_process_packet(m, isr->next, 0, 0);
174 			/* NOTREACHED */
175 #endif
176 #ifdef notyet
177 #ifdef INET6
178 		case AF_INET6:
179 			/* XXX */
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 		IPSECSTAT_INC(ips_out_nosa);
362 		goto bad;
363 	}
364 	sav = isr->sav;
365 	if (sav == NULL) {
366 		IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
367 			("no SA found, but required; level %u",
368 			ipsec_get_reqlevel(isr)));
369 		IPSECREQUEST_UNLOCK(isr);
370 		isr = isr->next;
371 		/*
372 		 * If isr is NULL, we found a 'use' policy w/o SA.
373 		 * Return w/o error and w/o isr so we can drop out
374 		 * and continue w/o IPsec processing.
375 		 */
376 		if (isr == NULL)
377 			return isr;
378 		IPSECREQUEST_LOCK(isr);
379 		goto again;
380 	}
381 
382 	/*
383 	 * Check system global policy controls.
384 	 */
385 	if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
386 	    (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
387 	    (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
388 		DPRINTF(("%s: IPsec outbound packet dropped due"
389 			" to policy (check your sysctls)\n", __func__));
390 		IPSEC_OSTAT(pdrops);
391 		*error = EHOSTUNREACH;
392 		goto bad;
393 	}
394 
395 	/*
396 	 * Sanity check the SA contents for the caller
397 	 * before they invoke the xform output method.
398 	 */
399 	if (sav->tdb_xform == NULL) {
400 		DPRINTF(("%s: no transform for SA\n", __func__));
401 		IPSEC_OSTAT(noxform);
402 		*error = EHOSTUNREACH;
403 		goto bad;
404 	}
405 	return isr;
406 bad:
407 	IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
408 	IPSECREQUEST_UNLOCK(isr);
409 	return NULL;
410 #undef IPSEC_OSTAT
411 }
412 
413 #ifdef INET
414 /*
415  * IPsec output logic for IPv4.
416  */
417 int
418 ipsec4_process_packet(
419 	struct mbuf *m,
420 	struct ipsecrequest *isr,
421 	int flags,
422 	int tunalready)
423 {
424 	struct secasindex saidx;
425 	struct secasvar *sav;
426 	struct ip *ip;
427 	int error, i, off;
428 
429 	IPSEC_ASSERT(m != NULL, ("null mbuf"));
430 	IPSEC_ASSERT(isr != NULL, ("null isr"));
431 
432 	IPSECREQUEST_LOCK(isr);		/* insure SA contents don't change */
433 
434 	isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
435 	if (isr == NULL) {
436 		if (error != 0)
437 			goto bad;
438 		return EJUSTRETURN;
439 	}
440 
441 	sav = isr->sav;
442 
443 #ifdef DEV_ENC
444 	if_inc_counter(encif, IFCOUNTER_OPACKETS, 1);
445 	if_inc_counter(encif, IFCOUNTER_OBYTES, m->m_pkthdr.len);
446 
447 	/* pass the mbuf to enc0 for bpf processing */
448 	ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
449 	/* pass the mbuf to enc0 for packet filtering */
450 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
451 		goto bad;
452 #endif
453 
454 	if (!tunalready) {
455 		union sockaddr_union *dst = &sav->sah->saidx.dst;
456 		int setdf;
457 
458 		/*
459 		 * Collect IP_DF state from the outer header.
460 		 */
461 		if (dst->sa.sa_family == AF_INET) {
462 			if (m->m_len < sizeof (struct ip) &&
463 			    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
464 				error = ENOBUFS;
465 				goto bad;
466 			}
467 			ip = mtod(m, struct ip *);
468 			/* Honor system-wide control of how to handle IP_DF */
469 			switch (V_ip4_ipsec_dfbit) {
470 			case 0:			/* clear in outer header */
471 			case 1:			/* set in outer header */
472 				setdf = V_ip4_ipsec_dfbit;
473 				break;
474 			default:		/* propagate to outer header */
475 				setdf = ntohs(ip->ip_off & IP_DF);
476 				break;
477 			}
478 		} else {
479 			ip = NULL;		/* keep compiler happy */
480 			setdf = 0;
481 		}
482 		/* Do the appropriate encapsulation, if necessary */
483 		if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
484 		    dst->sa.sa_family != AF_INET ||	    /* PF mismatch */
485 #if 0
486 		    (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
487 		    sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
488 #endif
489 		    (dst->sa.sa_family == AF_INET &&	    /* Proxy */
490 		     dst->sin.sin_addr.s_addr != INADDR_ANY &&
491 		     dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
492 			struct mbuf *mp;
493 
494 			/* Fix IPv4 header checksum and length */
495 			if (m->m_len < sizeof (struct ip) &&
496 			    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
497 				error = ENOBUFS;
498 				goto bad;
499 			}
500 			ip = mtod(m, struct ip *);
501 			if (ip->ip_v == IPVERSION) {
502 				ip->ip_len = htons(m->m_pkthdr.len);
503 				ip->ip_sum = 0;
504 				ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
505 			}
506 
507 			/* Encapsulate the packet */
508 			error = ipip_output(m, isr, &mp, 0, 0);
509 			if (mp == NULL && !error) {
510 				/* Should never happen. */
511 				DPRINTF(("%s: ipip_output returns no mbuf and "
512 					"no error!", __func__));
513 				error = EFAULT;
514 			}
515 			if (error) {
516 				if (mp) {
517 					/* XXX: Should never happen! */
518 					m_freem(mp);
519 				}
520 				m = NULL; /* ipip_output() already freed it */
521 				goto bad;
522 			}
523 			m = mp, mp = NULL;
524 			/*
525 			 * ipip_output clears IP_DF in the new header.  If
526 			 * we need to propagate IP_DF from the outer header,
527 			 * then we have to do it here.
528 			 *
529 			 * XXX shouldn't assume what ipip_output does.
530 			 */
531 			if (dst->sa.sa_family == AF_INET && setdf) {
532 				if (m->m_len < sizeof (struct ip) &&
533 				    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
534 					error = ENOBUFS;
535 					goto bad;
536 				}
537 				ip = mtod(m, struct ip *);
538 				ip->ip_off = ntohs(ip->ip_off);
539 				ip->ip_off |= IP_DF;
540 				ip->ip_off = htons(ip->ip_off);
541 			}
542 		}
543 	}
544 
545 #ifdef DEV_ENC
546 	/* pass the mbuf to enc0 for bpf processing */
547 	ipsec_bpf(m, sav, sav->sah->saidx.dst.sa.sa_family, ENC_OUT|ENC_AFTER);
548 	/* pass the mbuf to enc0 for packet filtering */
549 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
550 		goto bad;
551 #endif
552 
553 	/*
554 	 * Dispatch to the appropriate IPsec transform logic.  The
555 	 * packet will be returned for transmission after crypto
556 	 * processing, etc. are completed.  For encapsulation we
557 	 * bypass this call because of the explicit call done above
558 	 * (necessary to deal with IP_DF handling for IPv4).
559 	 *
560 	 * NB: m & sav are ``passed to caller'' who's reponsible for
561 	 *     for reclaiming their resources.
562 	 */
563 	if (sav->tdb_xform->xf_type != XF_IP4) {
564 		union sockaddr_union *dst = &sav->sah->saidx.dst;
565 		switch(dst->sa.sa_family) {
566 		case AF_INET:
567 			ip = mtod(m, struct ip *);
568 			i = ip->ip_hl << 2;
569 			off = offsetof(struct ip, ip_p);
570 			break;
571 #ifdef INET6
572 		case AF_INET6:
573 			i = sizeof(struct ip6_hdr);
574 			off = offsetof(struct ip6_hdr, ip6_nxt);
575 			break;
576 #endif /* INET6 */
577 		default:
578 		DPRINTF(("%s: unsupported protocol family %u\n",
579 				 __func__, dst->sa.sa_family));
580 			error = EPFNOSUPPORT;
581 			IPSECSTAT_INC(ips_out_inval);
582 			goto bad;
583 		}
584 		error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
585 	} else {
586 		error = ipsec_process_done(m, isr);
587 	}
588 	IPSECREQUEST_UNLOCK(isr);
589 	return error;
590 bad:
591 	if (isr)
592 		IPSECREQUEST_UNLOCK(isr);
593 	if (m)
594 		m_freem(m);
595 	return error;
596 }
597 #endif
598 
599 
600 #ifdef INET6
601 static int
602 in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, const struct in6_addr *ia)
603 {
604 	struct in6_addr ia2;
605 
606 	memcpy(&ia2, &sa->sin6_addr, sizeof(ia2));
607 	if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr))
608 		ia2.s6_addr16[1] = htons(sa->sin6_scope_id);
609 
610 	return IN6_ARE_ADDR_EQUAL(ia, &ia2);
611 }
612 
613 /*
614  * IPsec output logic for IPv6.
615  */
616 int
617 ipsec6_process_packet(
618 	struct mbuf *m,
619  	struct ipsecrequest *isr
620     )
621 {
622 	struct secasindex saidx;
623 	struct secasvar *sav;
624 	struct ip6_hdr *ip6;
625 	int error, i, off;
626 	union sockaddr_union *dst;
627 
628 	IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf"));
629 	IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr"));
630 
631 	IPSECREQUEST_LOCK(isr);		/* insure SA contents don't change */
632 
633 	isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
634 	if (isr == NULL) {
635 		if (error != 0)
636 			goto bad;
637 		return EJUSTRETURN;
638 	}
639 
640 	sav = isr->sav;
641 	dst = &sav->sah->saidx.dst;
642 
643 #ifdef DEV_ENC
644 	if_inc_counter(encif, IFCOUNTER_OPACKETS, 1);
645 	if_inc_counter(encif, IFCOUNTER_OBYTES, m->m_pkthdr.len);
646 
647 	/* pass the mbuf to enc0 for bpf processing */
648 	ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
649 	/* pass the mbuf to enc0 for packet filtering */
650 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
651 		goto bad;
652 #endif /* DEV_ENC */
653 
654 	ip6 = mtod(m, struct ip6_hdr *); /* XXX */
655 
656 	/* Do the appropriate encapsulation, if necessary */
657 	if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
658 	    dst->sa.sa_family != AF_INET6 ||        /* PF mismatch */
659 	    ((dst->sa.sa_family == AF_INET6) &&
660 	     (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) &&
661 	     (!in6_sa_equal_addrwithscope(&dst->sin6,
662 				  &ip6->ip6_dst)))) {
663 		struct mbuf *mp;
664 
665 		/* Fix IPv6 header payload length. */
666 		if (m->m_len < sizeof(struct ip6_hdr))
667 			if ((m = m_pullup(m,sizeof(struct ip6_hdr))) == NULL) {
668 				error = ENOBUFS;
669 				goto bad;
670 			}
671 
672 		if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) {
673 			/* No jumbogram support. */
674 			error = ENXIO;   /*XXX*/
675 			goto bad;
676 		}
677 
678 		ip6 = mtod(m, struct ip6_hdr *);
679 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
680 
681 		/* Encapsulate the packet */
682 		error = ipip_output(m, isr, &mp, 0, 0);
683 		if (mp == NULL && !error) {
684 			/* Should never happen. */
685 			DPRINTF(("ipsec6_process_packet: ipip_output "
686 				 "returns no mbuf and no error!"));
687 			error = EFAULT;
688 			goto bad;
689 		}
690 
691 		if (error) {
692 			if (mp) {
693 				/* XXX: Should never happen! */
694 				m_freem(mp);
695 			}
696 			m = NULL; /* ipip_output() already freed it */
697 			goto bad;
698 		}
699 
700 		m = mp;
701 		mp = NULL;
702 	}
703 
704 #ifdef DEV_ENC
705 	ipsec_bpf(m, isr->sav, dst->sa.sa_family, ENC_OUT|ENC_AFTER);
706 	/* pass the mbuf to enc0 for packet filtering */
707 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
708 		goto bad;
709 #endif /* DEV_ENC */
710 
711 	switch(dst->sa.sa_family) {
712 #ifdef INET
713 	case AF_INET:
714 		{
715 		struct ip *ip;
716 		ip = mtod(m, struct ip *);
717 		i = ip->ip_hl << 2;
718 		off = offsetof(struct ip, ip_p);
719 		}
720 		break;
721 #endif /* AF_INET */
722 	case AF_INET6:
723 		i = sizeof(struct ip6_hdr);
724 		off = offsetof(struct ip6_hdr, ip6_nxt);
725 		break;
726 	default:
727 		DPRINTF(("%s: unsupported protocol family %u\n",
728 				 __func__, dst->sa.sa_family));
729 		error = EPFNOSUPPORT;
730 		IPSEC6STAT_INC(ips_out_inval);
731 		goto bad;
732 	}
733 	error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
734 	IPSECREQUEST_UNLOCK(isr);
735 	return error;
736 bad:
737 
738 	if (isr)
739 		IPSECREQUEST_UNLOCK(isr);
740 	if (m)
741 		m_freem(m);
742 	return error;
743 }
744 #endif /*INET6*/
745