xref: /freebsd/sys/netipsec/ipsec_output.c (revision 952364486a4b9d135e4b28f7f88a8703a74eae6f)
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/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 #include <netinet6/scope6_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 		/* XXX-BZ currently only support same AF bundles. */
169 		switch (saidx->dst.sa.sa_family) {
170 #ifdef INET
171 		case AF_INET:
172 			IPSECSTAT_INC(ips_out_bundlesa);
173 			return ipsec4_process_packet(m, isr->next);
174 			/* NOTREACHED */
175 #endif
176 #ifdef notyet
177 #ifdef INET6
178 		case AF_INET6:
179 			/* XXX */
180 			IPSEC6STAT_INC(ips_out_bundlesa);
181 			return ipsec6_process_packet(m, isr->next);
182 			/* NOTREACHED */
183 #endif /* INET6 */
184 #endif
185 		default:
186 			DPRINTF(("%s: unknown protocol family %u\n", __func__,
187 			    saidx->dst.sa.sa_family));
188 			error = ENXIO;
189 			goto bad;
190 		}
191 	}
192 	key_sa_recordxfer(sav, m);		/* record data transfer */
193 
194 	/*
195 	 * We're done with IPsec processing, transmit the packet using the
196 	 * appropriate network protocol (IP or IPv6). SPD lookup will be
197 	 * performed again there.
198 	 */
199 	switch (saidx->dst.sa.sa_family) {
200 #ifdef INET
201 	case AF_INET:
202 #ifdef IPSEC_NAT_T
203 		/*
204 		 * If NAT-T is enabled, now that all IPsec processing is done
205 		 * insert UDP encapsulation header after IP header.
206 		 */
207 		if (sav->natt_type) {
208 			struct ip *ip = mtod(m, struct ip *);
209 			const int hlen = (ip->ip_hl << 2);
210 			int size, off;
211 			struct mbuf *mi;
212 			struct udphdr *udp;
213 
214 			size = sizeof(struct udphdr);
215 			if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
216 				/*
217 				 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
218 				 * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
219 				 * ignoring possible AH mode
220 				 * non-IKE marker + non-ESP marker
221 				 * from draft-ietf-ipsec-udp-encaps-00.txt.
222 				 */
223 				size += sizeof(u_int64_t);
224 			}
225 			mi = m_makespace(m, hlen, size, &off);
226 			if (mi == NULL) {
227 				DPRINTF(("%s: m_makespace for udphdr failed\n",
228 				    __func__));
229 				error = ENOBUFS;
230 				goto bad;
231 			}
232 
233 			udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
234 			if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
235 				udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
236 			else
237 				udp->uh_sport =
238 					KEY_PORTFROMSADDR(&sav->sah->saidx.src);
239 			udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
240 			udp->uh_sum = 0;
241 			udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
242 			ip->ip_len = htons(m->m_pkthdr.len);
243 			ip->ip_p = IPPROTO_UDP;
244 
245 			if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
246 				*(u_int64_t *)(udp + 1) = 0;
247 		}
248 #endif /* IPSEC_NAT_T */
249 
250 		return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
251 #endif /* INET */
252 #ifdef INET6
253 	case AF_INET6:
254 		/*
255 		 * We don't need massage, IPv6 header fields are always in
256 		 * net endian.
257 		 */
258 		return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
259 #endif /* INET6 */
260 	}
261 	panic("ipsec_process_done");
262 bad:
263 	m_freem(m);
264 	return (error);
265 }
266 
267 static struct ipsecrequest *
268 ipsec_nextisr(
269 	struct mbuf *m,
270 	struct ipsecrequest *isr,
271 	int af,
272 	struct secasindex *saidx,
273 	int *error
274 )
275 {
276 #define	IPSEC_OSTAT(name)	do {		\
277 	if (isr->saidx.proto == IPPROTO_ESP)	\
278 		ESPSTAT_INC(esps_##name);	\
279 	else if (isr->saidx.proto == IPPROTO_AH)\
280 		AHSTAT_INC(ahs_##name);		\
281 	else					\
282 		IPCOMPSTAT_INC(ipcomps_##name);	\
283 } while (0)
284 	struct secasvar *sav;
285 
286 	IPSECREQUEST_LOCK_ASSERT(isr);
287 
288 	IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
289 		("invalid address family %u", af));
290 again:
291 	/*
292 	 * Craft SA index to search for proper SA.  Note that
293 	 * we only fillin unspecified SA peers for transport
294 	 * mode; for tunnel mode they must already be filled in.
295 	 */
296 	*saidx = isr->saidx;
297 	if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
298 		/* Fillin unspecified SA peers only for transport mode */
299 		if (af == AF_INET) {
300 			struct sockaddr_in *sin;
301 			struct ip *ip = mtod(m, struct ip *);
302 
303 			if (saidx->src.sa.sa_len == 0) {
304 				sin = &saidx->src.sin;
305 				sin->sin_len = sizeof(*sin);
306 				sin->sin_family = AF_INET;
307 				sin->sin_port = IPSEC_PORT_ANY;
308 				sin->sin_addr = ip->ip_src;
309 			}
310 			if (saidx->dst.sa.sa_len == 0) {
311 				sin = &saidx->dst.sin;
312 				sin->sin_len = sizeof(*sin);
313 				sin->sin_family = AF_INET;
314 				sin->sin_port = IPSEC_PORT_ANY;
315 				sin->sin_addr = ip->ip_dst;
316 			}
317 		} else {
318 			struct sockaddr_in6 *sin6;
319 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
320 
321 			if (saidx->src.sin6.sin6_len == 0) {
322 				sin6 = (struct sockaddr_in6 *)&saidx->src;
323 				sin6->sin6_len = sizeof(*sin6);
324 				sin6->sin6_family = AF_INET6;
325 				sin6->sin6_port = IPSEC_PORT_ANY;
326 				sin6->sin6_addr = ip6->ip6_src;
327 				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
328 					/* fix scope id for comparing SPD */
329 					sin6->sin6_addr.s6_addr16[1] = 0;
330 					sin6->sin6_scope_id =
331 					    ntohs(ip6->ip6_src.s6_addr16[1]);
332 				}
333 			}
334 			if (saidx->dst.sin6.sin6_len == 0) {
335 				sin6 = (struct sockaddr_in6 *)&saidx->dst;
336 				sin6->sin6_len = sizeof(*sin6);
337 				sin6->sin6_family = AF_INET6;
338 				sin6->sin6_port = IPSEC_PORT_ANY;
339 				sin6->sin6_addr = ip6->ip6_dst;
340 				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
341 					/* fix scope id for comparing SPD */
342 					sin6->sin6_addr.s6_addr16[1] = 0;
343 					sin6->sin6_scope_id =
344 					    ntohs(ip6->ip6_dst.s6_addr16[1]);
345 				}
346 			}
347 		}
348 	}
349 
350 	/*
351 	 * Lookup SA and validate it.
352 	 */
353 	*error = key_checkrequest(isr, saidx);
354 	if (*error != 0) {
355 		/*
356 		 * IPsec processing is required, but no SA found.
357 		 * I assume that key_acquire() had been called
358 		 * to get/establish the SA. Here I discard
359 		 * this packet because it is responsibility for
360 		 * upper layer to retransmit the packet.
361 		 */
362 		switch(af) {
363 		case AF_INET:
364 			IPSECSTAT_INC(ips_out_nosa);
365 			break;
366 #ifdef INET6
367 		case AF_INET6:
368 			IPSEC6STAT_INC(ips_out_nosa);
369 			break;
370 #endif
371 		}
372 		goto bad;
373 	}
374 	sav = isr->sav;
375 	if (sav == NULL) {
376 		IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
377 			("no SA found, but required; level %u",
378 			ipsec_get_reqlevel(isr)));
379 		IPSECREQUEST_UNLOCK(isr);
380 		isr = isr->next;
381 		/*
382 		 * If isr is NULL, we found a 'use' policy w/o SA.
383 		 * Return w/o error and w/o isr so we can drop out
384 		 * and continue w/o IPsec processing.
385 		 */
386 		if (isr == NULL)
387 			return isr;
388 		IPSECREQUEST_LOCK(isr);
389 		goto again;
390 	}
391 
392 	/*
393 	 * Check system global policy controls.
394 	 */
395 	if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
396 	    (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
397 	    (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
398 		DPRINTF(("%s: IPsec outbound packet dropped due"
399 			" to policy (check your sysctls)\n", __func__));
400 		IPSEC_OSTAT(pdrops);
401 		*error = EHOSTUNREACH;
402 		goto bad;
403 	}
404 
405 	/*
406 	 * Sanity check the SA contents for the caller
407 	 * before they invoke the xform output method.
408 	 */
409 	if (sav->tdb_xform == NULL) {
410 		DPRINTF(("%s: no transform for SA\n", __func__));
411 		IPSEC_OSTAT(noxform);
412 		*error = EHOSTUNREACH;
413 		goto bad;
414 	}
415 	return isr;
416 bad:
417 	IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
418 	IPSECREQUEST_UNLOCK(isr);
419 	return NULL;
420 #undef IPSEC_OSTAT
421 }
422 
423 static int
424 ipsec_encap(struct mbuf **mp, struct secasindex *saidx)
425 {
426 #ifdef INET6
427 	struct ip6_hdr *ip6;
428 #endif
429 	struct ip *ip;
430 	int setdf;
431 	uint8_t itos, proto;
432 
433 	ip = mtod(*mp, struct ip *);
434 	switch (ip->ip_v) {
435 #ifdef INET
436 	case IPVERSION:
437 		proto = IPPROTO_IPIP;
438 		/*
439 		 * Collect IP_DF state from the inner header
440 		 * and honor system-wide control of how to handle it.
441 		 */
442 		switch (V_ip4_ipsec_dfbit) {
443 		case 0:	/* clear in outer header */
444 		case 1:	/* set in outer header */
445 			setdf = V_ip4_ipsec_dfbit;
446 			break;
447 		default:/* propagate to outer header */
448 			setdf = (ip->ip_off & ntohs(IP_DF)) != 0;
449 		}
450 		itos = ip->ip_tos;
451 		break;
452 #endif
453 #ifdef INET6
454 	case (IPV6_VERSION >> 4):
455 		proto = IPPROTO_IPV6;
456 		ip6 = mtod(*mp, struct ip6_hdr *);
457 		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
458 		setdf = V_ip4_ipsec_dfbit ? 1: 0;
459 		/* scoped address handling */
460 		in6_clearscope(&ip6->ip6_src);
461 		in6_clearscope(&ip6->ip6_dst);
462 		break;
463 #endif
464 	default:
465 		return (EAFNOSUPPORT);
466 	}
467 	switch (saidx->dst.sa.sa_family) {
468 #ifdef INET
469 	case AF_INET:
470 		if (saidx->src.sa.sa_family != AF_INET ||
471 		    saidx->src.sin.sin_addr.s_addr == INADDR_ANY ||
472 		    saidx->dst.sin.sin_addr.s_addr == INADDR_ANY)
473 			return (EINVAL);
474 		M_PREPEND(*mp, sizeof(struct ip), M_NOWAIT);
475 		if (*mp == NULL)
476 			return (ENOBUFS);
477 		ip = mtod(*mp, struct ip *);
478 		ip->ip_v = IPVERSION;
479 		ip->ip_hl = sizeof(struct ip) >> 2;
480 		ip->ip_p = proto;
481 		ip->ip_len = htons((*mp)->m_pkthdr.len);
482 		ip->ip_ttl = V_ip_defttl;
483 		ip->ip_sum = 0;
484 		ip->ip_off = setdf ? htons(IP_DF): 0;
485 		ip->ip_src = saidx->src.sin.sin_addr;
486 		ip->ip_dst = saidx->dst.sin.sin_addr;
487 		ip_ecn_ingress(V_ip4_ipsec_ecn, &ip->ip_tos, &itos);
488 		ip_fillid(ip);
489 		break;
490 #endif /* INET */
491 #ifdef INET6
492 	case AF_INET6:
493 		if (saidx->src.sa.sa_family != AF_INET6 ||
494 		    IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr) ||
495 		    IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr))
496 			return (EINVAL);
497 		M_PREPEND(*mp, sizeof(struct ip6_hdr), M_NOWAIT);
498 		if (*mp == NULL)
499 			return (ENOBUFS);
500 		ip6 = mtod(*mp, struct ip6_hdr *);
501 		ip6->ip6_flow = 0;
502 		ip6->ip6_vfc = IPV6_VERSION;
503 		ip6->ip6_hlim = V_ip6_defhlim;
504 		ip6->ip6_nxt = proto;
505 		ip6->ip6_dst = saidx->dst.sin6.sin6_addr;
506 		/* For link-local address embed scope zone id */
507 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
508 			ip6->ip6_dst.s6_addr16[1] =
509 			    htons(saidx->dst.sin6.sin6_scope_id & 0xffff);
510 		ip6->ip6_src = saidx->src.sin6.sin6_addr;
511 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
512 			ip6->ip6_src.s6_addr16[1] =
513 			    htons(saidx->src.sin6.sin6_scope_id & 0xffff);
514 		ip6->ip6_plen = htons((*mp)->m_pkthdr.len - sizeof(*ip6));
515 		ip_ecn_ingress(V_ip6_ipsec_ecn, &proto, &itos);
516 		ip6->ip6_flow |= htonl((uint32_t)proto << 20);
517 		break;
518 #endif /* INET6 */
519 	default:
520 		return (EAFNOSUPPORT);
521 	}
522 	return (0);
523 }
524 
525 #ifdef INET
526 /*
527  * IPsec output logic for IPv4.
528  */
529 int
530 ipsec4_process_packet(struct mbuf *m, struct ipsecrequest *isr)
531 {
532 	char sbuf[INET6_ADDRSTRLEN], dbuf[INET6_ADDRSTRLEN];
533 	union sockaddr_union *dst;
534 	struct secasindex saidx;
535 	struct secasvar *sav;
536 	struct ip *ip;
537 	int error, i, off;
538 
539 	IPSEC_ASSERT(m != NULL, ("null mbuf"));
540 	IPSEC_ASSERT(isr != NULL, ("null isr"));
541 
542 	IPSECREQUEST_LOCK(isr);		/* insure SA contents don't change */
543 
544 	isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
545 	if (isr == NULL) {
546 		if (error != 0)
547 			goto bad;
548 		return EJUSTRETURN;
549 	}
550 
551 	sav = isr->sav;
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 	dst = &sav->sah->saidx.dst;
559 #ifdef DEV_ENC
560 	if_inc_counter(encif, IFCOUNTER_OPACKETS, 1);
561 	if_inc_counter(encif, IFCOUNTER_OBYTES, m->m_pkthdr.len);
562 
563 	/* pass the mbuf to enc0 for bpf processing */
564 	ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
565 	/* pass the mbuf to enc0 for packet filtering */
566 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
567 		goto bad;
568 #endif
569 	/* Do the appropriate encapsulation, if necessary */
570 	if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
571 	    dst->sa.sa_family != AF_INET ||	    /* PF mismatch */
572 	    (dst->sa.sa_family == AF_INET &&	    /* Proxy */
573 	     dst->sin.sin_addr.s_addr != INADDR_ANY &&
574 	     dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
575 		/* Fix IPv4 header checksum and length */
576 		ip->ip_len = htons(m->m_pkthdr.len);
577 		ip->ip_sum = 0;
578 		ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
579 		error = ipsec_encap(&m, &sav->sah->saidx);
580 		if (error != 0) {
581 			DPRINTF(("%s: encapsulation for SA %s->%s "
582 			    "SPI 0x%08x failed with error %d\n", __func__,
583 			    ipsec_address(&sav->sah->saidx.src, sbuf,
584 				sizeof(sbuf)),
585 			    ipsec_address(&sav->sah->saidx.dst, dbuf,
586 				sizeof(dbuf)), ntohl(sav->spi), error));
587 			goto bad;
588 		}
589 	}
590 #ifdef DEV_ENC
591 	/* pass the mbuf to enc0 for bpf processing */
592 	ipsec_bpf(m, sav, sav->sah->saidx.dst.sa.sa_family, ENC_OUT|ENC_AFTER);
593 	/* pass the mbuf to enc0 for packet filtering */
594 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
595 		goto bad;
596 #endif
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.
602 	 *
603 	 * NB: m & sav are ``passed to caller'' who's reponsible for
604 	 *     for reclaiming their resources.
605 	 */
606 	switch(dst->sa.sa_family) {
607 	case AF_INET:
608 		ip = mtod(m, struct ip *);
609 		i = ip->ip_hl << 2;
610 		off = offsetof(struct ip, ip_p);
611 		break;
612 #ifdef INET6
613 	case AF_INET6:
614 		i = sizeof(struct ip6_hdr);
615 		off = offsetof(struct ip6_hdr, ip6_nxt);
616 		break;
617 #endif /* INET6 */
618 	default:
619 		DPRINTF(("%s: unsupported protocol family %u\n",
620 		    __func__, dst->sa.sa_family));
621 		error = EPFNOSUPPORT;
622 		IPSECSTAT_INC(ips_out_inval);
623 		goto bad;
624 	}
625 	error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
626 	IPSECREQUEST_UNLOCK(isr);
627 	return (error);
628 bad:
629 	if (isr)
630 		IPSECREQUEST_UNLOCK(isr);
631 	if (m)
632 		m_freem(m);
633 	return error;
634 }
635 #endif
636 
637 
638 #ifdef INET6
639 static int
640 in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, const struct in6_addr *ia)
641 {
642 	struct in6_addr ia2;
643 
644 	memcpy(&ia2, &sa->sin6_addr, sizeof(ia2));
645 	if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr))
646 		ia2.s6_addr16[1] = htons(sa->sin6_scope_id);
647 
648 	return IN6_ARE_ADDR_EQUAL(ia, &ia2);
649 }
650 
651 /*
652  * IPsec output logic for IPv6.
653  */
654 int
655 ipsec6_process_packet(struct mbuf *m, struct ipsecrequest *isr)
656 {
657 	char sbuf[INET6_ADDRSTRLEN], dbuf[INET6_ADDRSTRLEN];
658 	struct secasindex saidx;
659 	struct secasvar *sav;
660 	struct ip6_hdr *ip6;
661 	int error, i, off;
662 	union sockaddr_union *dst;
663 
664 	IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf"));
665 	IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr"));
666 
667 	IPSECREQUEST_LOCK(isr);		/* insure SA contents don't change */
668 
669 	isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
670 	if (isr == NULL) {
671 		if (error != 0)
672 			goto bad;
673 		return EJUSTRETURN;
674 	}
675 	sav = isr->sav;
676 	dst = &sav->sah->saidx.dst;
677 
678 	ip6 = mtod(m, struct ip6_hdr *);
679 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
680 #ifdef DEV_ENC
681 	if_inc_counter(encif, IFCOUNTER_OPACKETS, 1);
682 	if_inc_counter(encif, IFCOUNTER_OBYTES, m->m_pkthdr.len);
683 
684 	/* pass the mbuf to enc0 for bpf processing */
685 	ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
686 	/* pass the mbuf to enc0 for packet filtering */
687 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
688 		goto bad;
689 #endif /* DEV_ENC */
690 
691 	/* Do the appropriate encapsulation, if necessary */
692 	if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
693 	    dst->sa.sa_family != AF_INET6 ||        /* PF mismatch */
694 	    ((dst->sa.sa_family == AF_INET6) &&
695 	     (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) &&
696 	     (!in6_sa_equal_addrwithscope(&dst->sin6,
697 				  &ip6->ip6_dst)))) {
698 		if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) {
699 			/* No jumbogram support. */
700 			error = ENXIO;   /*XXX*/
701 			goto bad;
702 		}
703 		error = ipsec_encap(&m, &sav->sah->saidx);
704 		if (error != 0) {
705 			DPRINTF(("%s: encapsulation for SA %s->%s "
706 			    "SPI 0x%08x failed with error %d\n", __func__,
707 			    ipsec_address(&sav->sah->saidx.src, sbuf,
708 				sizeof(sbuf)),
709 			    ipsec_address(&sav->sah->saidx.dst, dbuf,
710 				sizeof(dbuf)), ntohl(sav->spi), error));
711 			goto bad;
712 		}
713 	}
714 
715 #ifdef DEV_ENC
716 	ipsec_bpf(m, isr->sav, dst->sa.sa_family, ENC_OUT|ENC_AFTER);
717 	/* pass the mbuf to enc0 for packet filtering */
718 	if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
719 		goto bad;
720 #endif /* DEV_ENC */
721 
722 	switch(dst->sa.sa_family) {
723 #ifdef INET
724 	case AF_INET:
725 		{
726 		struct ip *ip;
727 		ip = mtod(m, struct ip *);
728 		i = ip->ip_hl << 2;
729 		off = offsetof(struct ip, ip_p);
730 		}
731 		break;
732 #endif /* AF_INET */
733 	case AF_INET6:
734 		i = sizeof(struct ip6_hdr);
735 		off = offsetof(struct ip6_hdr, ip6_nxt);
736 		break;
737 	default:
738 		DPRINTF(("%s: unsupported protocol family %u\n",
739 				 __func__, dst->sa.sa_family));
740 		error = EPFNOSUPPORT;
741 		IPSEC6STAT_INC(ips_out_inval);
742 		goto bad;
743 	}
744 	error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
745 	IPSECREQUEST_UNLOCK(isr);
746 	return error;
747 bad:
748 
749 	if (isr)
750 		IPSECREQUEST_UNLOCK(isr);
751 	if (m)
752 		m_freem(m);
753 	return error;
754 }
755 #endif /*INET6*/
756