xref: /freebsd/sys/netipsec/ipsec_output.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
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 
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/hhook.h>
44 #include <sys/syslog.h>
45 
46 #include <net/if.h>
47 #include <net/if_enc.h>
48 #include <net/if_var.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 int
92 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
93 {
94 	struct tdb_ident *tdbi;
95 	struct m_tag *mtag;
96 	struct secasvar *sav;
97 	struct secasindex *saidx;
98 	int error;
99 
100 	IPSEC_ASSERT(m != NULL, ("null mbuf"));
101 	IPSEC_ASSERT(isr != NULL, ("null ISR"));
102 	IPSEC_ASSERT(isr->sp != NULL, ("NULL isr->sp"));
103 	sav = isr->sav;
104 	IPSEC_ASSERT(sav != NULL, ("null SA"));
105 	IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
106 
107 	saidx = &sav->sah->saidx;
108 	switch (saidx->dst.sa.sa_family) {
109 #ifdef INET
110 	case AF_INET:
111 		/* Fix the header length, for AH processing. */
112 		mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
113 		break;
114 #endif /* INET */
115 #ifdef INET6
116 	case AF_INET6:
117 		/* Fix the header length, for AH processing. */
118 		if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
119 			error = ENXIO;
120 			goto bad;
121 		}
122 		if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
123 			/* No jumbogram support. */
124 			error = ENXIO;	/*?*/
125 			goto bad;
126 		}
127 		mtod(m, struct ip6_hdr *)->ip6_plen =
128 			htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
129 		break;
130 #endif /* INET6 */
131 	default:
132 		DPRINTF(("%s: unknown protocol family %u\n", __func__,
133 		    saidx->dst.sa.sa_family));
134 		error = ENXIO;
135 		goto bad;
136 	}
137 
138 	/*
139 	 * Add a record of what we've done or what needs to be done to the
140 	 * packet.
141 	 */
142 	mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
143 			sizeof(struct tdb_ident), M_NOWAIT);
144 	if (mtag == NULL) {
145 		DPRINTF(("%s: could not get packet tag\n", __func__));
146 		error = ENOMEM;
147 		goto bad;
148 	}
149 
150 	tdbi = (struct tdb_ident *)(mtag + 1);
151 	tdbi->dst = saidx->dst;
152 	tdbi->proto = saidx->proto;
153 	tdbi->spi = sav->spi;
154 	m_tag_prepend(m, mtag);
155 
156 	key_sa_recordxfer(sav, m);		/* record data transfer */
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));
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 
191 	/*
192 	 * We're done with IPsec processing, transmit the packet using the
193 	 * appropriate network protocol (IP or IPv6).
194 	 */
195 	switch (saidx->dst.sa.sa_family) {
196 #ifdef INET
197 	case AF_INET:
198 #ifdef IPSEC_NAT_T
199 		/*
200 		 * If NAT-T is enabled, now that all IPsec processing is done
201 		 * insert UDP encapsulation header after IP header.
202 		 */
203 		if (sav->natt_type) {
204 			struct ip *ip = mtod(m, struct ip *);
205 			const int hlen = (ip->ip_hl << 2);
206 			int size, off;
207 			struct mbuf *mi;
208 			struct udphdr *udp;
209 
210 			size = sizeof(struct udphdr);
211 			if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
212 				/*
213 				 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
214 				 * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
215 				 * ignoring possible AH mode
216 				 * non-IKE marker + non-ESP marker
217 				 * from draft-ietf-ipsec-udp-encaps-00.txt.
218 				 */
219 				size += sizeof(u_int64_t);
220 			}
221 			mi = m_makespace(m, hlen, size, &off);
222 			if (mi == NULL) {
223 				DPRINTF(("%s: m_makespace for udphdr failed\n",
224 				    __func__));
225 				error = ENOBUFS;
226 				goto bad;
227 			}
228 
229 			udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
230 			if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
231 				udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
232 			else
233 				udp->uh_sport =
234 					KEY_PORTFROMSADDR(&sav->sah->saidx.src);
235 			udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
236 			udp->uh_sum = 0;
237 			udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
238 			ip->ip_len = htons(m->m_pkthdr.len);
239 			ip->ip_p = IPPROTO_UDP;
240 
241 			if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
242 				*(u_int64_t *)(udp + 1) = 0;
243 		}
244 #endif /* IPSEC_NAT_T */
245 
246 		return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
247 #endif /* INET */
248 #ifdef INET6
249 	case AF_INET6:
250 		/*
251 		 * We don't need massage, IPv6 header fields are always in
252 		 * net endian.
253 		 */
254 		return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
255 #endif /* INET6 */
256 	}
257 	panic("ipsec_process_done");
258 bad:
259 	m_freem(m);
260 	return (error);
261 }
262 
263 static struct ipsecrequest *
264 ipsec_nextisr(
265 	struct mbuf *m,
266 	struct ipsecrequest *isr,
267 	int af,
268 	struct secasindex *saidx,
269 	int *error
270 )
271 {
272 #define	IPSEC_OSTAT(name)	do {		\
273 	if (isr->saidx.proto == IPPROTO_ESP)	\
274 		ESPSTAT_INC(esps_##name);	\
275 	else if (isr->saidx.proto == IPPROTO_AH)\
276 		AHSTAT_INC(ahs_##name);		\
277 	else					\
278 		IPCOMPSTAT_INC(ipcomps_##name);	\
279 } while (0)
280 	struct secasvar *sav;
281 
282 	IPSECREQUEST_LOCK_ASSERT(isr);
283 
284 	IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
285 		("invalid address family %u", af));
286 again:
287 	/*
288 	 * Craft SA index to search for proper SA.  Note that
289 	 * we only fillin unspecified SA peers for transport
290 	 * mode; for tunnel mode they must already be filled in.
291 	 */
292 	*saidx = isr->saidx;
293 	if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
294 		/* Fillin unspecified SA peers only for transport mode */
295 		if (af == AF_INET) {
296 			struct sockaddr_in *sin;
297 			struct ip *ip = mtod(m, struct ip *);
298 
299 			if (saidx->src.sa.sa_len == 0) {
300 				sin = &saidx->src.sin;
301 				sin->sin_len = sizeof(*sin);
302 				sin->sin_family = AF_INET;
303 				sin->sin_port = IPSEC_PORT_ANY;
304 				sin->sin_addr = ip->ip_src;
305 			}
306 			if (saidx->dst.sa.sa_len == 0) {
307 				sin = &saidx->dst.sin;
308 				sin->sin_len = sizeof(*sin);
309 				sin->sin_family = AF_INET;
310 				sin->sin_port = IPSEC_PORT_ANY;
311 				sin->sin_addr = ip->ip_dst;
312 			}
313 		} else {
314 			struct sockaddr_in6 *sin6;
315 			struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
316 
317 			if (saidx->src.sin6.sin6_len == 0) {
318 				sin6 = (struct sockaddr_in6 *)&saidx->src;
319 				sin6->sin6_len = sizeof(*sin6);
320 				sin6->sin6_family = AF_INET6;
321 				sin6->sin6_port = IPSEC_PORT_ANY;
322 				sin6->sin6_addr = ip6->ip6_src;
323 				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
324 					/* fix scope id for comparing SPD */
325 					sin6->sin6_addr.s6_addr16[1] = 0;
326 					sin6->sin6_scope_id =
327 					    ntohs(ip6->ip6_src.s6_addr16[1]);
328 				}
329 			}
330 			if (saidx->dst.sin6.sin6_len == 0) {
331 				sin6 = (struct sockaddr_in6 *)&saidx->dst;
332 				sin6->sin6_len = sizeof(*sin6);
333 				sin6->sin6_family = AF_INET6;
334 				sin6->sin6_port = IPSEC_PORT_ANY;
335 				sin6->sin6_addr = ip6->ip6_dst;
336 				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
337 					/* fix scope id for comparing SPD */
338 					sin6->sin6_addr.s6_addr16[1] = 0;
339 					sin6->sin6_scope_id =
340 					    ntohs(ip6->ip6_dst.s6_addr16[1]);
341 				}
342 			}
343 		}
344 	}
345 
346 	/*
347 	 * Lookup SA and validate it.
348 	 */
349 	*error = key_checkrequest(isr, saidx);
350 	if (*error != 0) {
351 		/*
352 		 * IPsec processing is required, but no SA found.
353 		 * I assume that key_acquire() had been called
354 		 * to get/establish the SA. Here I discard
355 		 * this packet because it is responsibility for
356 		 * upper layer to retransmit the packet.
357 		 */
358 		switch(af) {
359 		case AF_INET:
360 			IPSECSTAT_INC(ips_out_nosa);
361 			break;
362 #ifdef INET6
363 		case AF_INET6:
364 			IPSEC6STAT_INC(ips_out_nosa);
365 			break;
366 #endif
367 		}
368 		goto bad;
369 	}
370 	sav = isr->sav;
371 	if (sav == NULL) {
372 		IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
373 			("no SA found, but required; level %u",
374 			ipsec_get_reqlevel(isr)));
375 		IPSECREQUEST_UNLOCK(isr);
376 		isr = isr->next;
377 		/*
378 		 * If isr is NULL, we found a 'use' policy w/o SA.
379 		 * Return w/o error and w/o isr so we can drop out
380 		 * and continue w/o IPsec processing.
381 		 */
382 		if (isr == NULL)
383 			return isr;
384 		IPSECREQUEST_LOCK(isr);
385 		goto again;
386 	}
387 
388 	/*
389 	 * Check system global policy controls.
390 	 */
391 	if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
392 	    (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
393 	    (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
394 		DPRINTF(("%s: IPsec outbound packet dropped due"
395 			" to policy (check your sysctls)\n", __func__));
396 		IPSEC_OSTAT(pdrops);
397 		*error = EHOSTUNREACH;
398 		goto bad;
399 	}
400 
401 	/*
402 	 * Sanity check the SA contents for the caller
403 	 * before they invoke the xform output method.
404 	 */
405 	if (sav->tdb_xform == NULL) {
406 		DPRINTF(("%s: no transform for SA\n", __func__));
407 		IPSEC_OSTAT(noxform);
408 		*error = EHOSTUNREACH;
409 		goto bad;
410 	}
411 	return isr;
412 bad:
413 	IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
414 	IPSECREQUEST_UNLOCK(isr);
415 	return NULL;
416 #undef IPSEC_OSTAT
417 }
418 
419 static int
420 ipsec_encap(struct mbuf **mp, struct secasindex *saidx)
421 {
422 #ifdef INET6
423 	struct ip6_hdr *ip6;
424 #endif
425 	struct ip *ip;
426 	int setdf;
427 	uint8_t itos, proto;
428 
429 	ip = mtod(*mp, struct ip *);
430 	switch (ip->ip_v) {
431 #ifdef INET
432 	case IPVERSION:
433 		proto = IPPROTO_IPIP;
434 		/*
435 		 * Collect IP_DF state from the inner header
436 		 * and honor system-wide control of how to handle it.
437 		 */
438 		switch (V_ip4_ipsec_dfbit) {
439 		case 0:	/* clear in outer header */
440 		case 1:	/* set in outer header */
441 			setdf = V_ip4_ipsec_dfbit;
442 			break;
443 		default:/* propagate to outer header */
444 			setdf = (ip->ip_off & ntohs(IP_DF)) != 0;
445 		}
446 		itos = ip->ip_tos;
447 		break;
448 #endif
449 #ifdef INET6
450 	case (IPV6_VERSION >> 4):
451 		proto = IPPROTO_IPV6;
452 		ip6 = mtod(*mp, struct ip6_hdr *);
453 		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
454 		setdf = V_ip4_ipsec_dfbit ? 1: 0;
455 		/* scoped address handling */
456 		in6_clearscope(&ip6->ip6_src);
457 		in6_clearscope(&ip6->ip6_dst);
458 		break;
459 #endif
460 	default:
461 		return (EAFNOSUPPORT);
462 	}
463 	switch (saidx->dst.sa.sa_family) {
464 #ifdef INET
465 	case AF_INET:
466 		if (saidx->src.sa.sa_family != AF_INET ||
467 		    saidx->src.sin.sin_addr.s_addr == INADDR_ANY ||
468 		    saidx->dst.sin.sin_addr.s_addr == INADDR_ANY)
469 			return (EINVAL);
470 		M_PREPEND(*mp, sizeof(struct ip), M_NOWAIT);
471 		if (*mp == NULL)
472 			return (ENOBUFS);
473 		ip = mtod(*mp, struct ip *);
474 		ip->ip_v = IPVERSION;
475 		ip->ip_hl = sizeof(struct ip) >> 2;
476 		ip->ip_p = proto;
477 		ip->ip_len = htons((*mp)->m_pkthdr.len);
478 		ip->ip_ttl = V_ip_defttl;
479 		ip->ip_sum = 0;
480 		ip->ip_off = setdf ? htons(IP_DF): 0;
481 		ip->ip_src = saidx->src.sin.sin_addr;
482 		ip->ip_dst = saidx->dst.sin.sin_addr;
483 		ip_ecn_ingress(V_ip4_ipsec_ecn, &ip->ip_tos, &itos);
484 		ip_fillid(ip);
485 		break;
486 #endif /* INET */
487 #ifdef INET6
488 	case AF_INET6:
489 		if (saidx->src.sa.sa_family != AF_INET6 ||
490 		    IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr) ||
491 		    IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr))
492 			return (EINVAL);
493 		M_PREPEND(*mp, sizeof(struct ip6_hdr), M_NOWAIT);
494 		if (*mp == NULL)
495 			return (ENOBUFS);
496 		ip6 = mtod(*mp, struct ip6_hdr *);
497 		ip6->ip6_flow = 0;
498 		ip6->ip6_vfc = IPV6_VERSION;
499 		ip6->ip6_hlim = V_ip6_defhlim;
500 		ip6->ip6_nxt = proto;
501 		ip6->ip6_dst = saidx->dst.sin6.sin6_addr;
502 		/* For link-local address embed scope zone id */
503 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
504 			ip6->ip6_dst.s6_addr16[1] =
505 			    htons(saidx->dst.sin6.sin6_scope_id & 0xffff);
506 		ip6->ip6_src = saidx->src.sin6.sin6_addr;
507 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
508 			ip6->ip6_src.s6_addr16[1] =
509 			    htons(saidx->src.sin6.sin6_scope_id & 0xffff);
510 		ip6->ip6_plen = htons((*mp)->m_pkthdr.len - sizeof(*ip6));
511 		ip_ecn_ingress(V_ip6_ipsec_ecn, &proto, &itos);
512 		ip6->ip6_flow |= htonl((uint32_t)proto << 20);
513 		break;
514 #endif /* INET6 */
515 	default:
516 		return (EAFNOSUPPORT);
517 	}
518 	return (0);
519 }
520 
521 #ifdef INET
522 /*
523  * IPsec output logic for IPv4.
524  */
525 int
526 ipsec4_process_packet(struct mbuf *m, struct ipsecrequest *isr)
527 {
528 	char sbuf[INET6_ADDRSTRLEN], dbuf[INET6_ADDRSTRLEN];
529 	struct ipsec_ctx_data ctx;
530 	union sockaddr_union *dst;
531 	struct secasindex saidx;
532 	struct secasvar *sav;
533 	struct ip *ip;
534 	int error, i, off;
535 
536 	IPSEC_ASSERT(m != NULL, ("null mbuf"));
537 	IPSEC_ASSERT(isr != NULL, ("null isr"));
538 
539 	IPSECREQUEST_LOCK(isr);		/* insure SA contents don't change */
540 
541 	isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
542 	if (isr == NULL) {
543 		if (error != 0)
544 			goto bad;
545 		return EJUSTRETURN;
546 	}
547 
548 	sav = isr->sav;
549 	if (m->m_len < sizeof(struct ip) &&
550 	    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
551 		error = ENOBUFS;
552 		goto bad;
553 	}
554 
555 	IPSEC_INIT_CTX(&ctx, &m, sav, AF_INET, IPSEC_ENC_BEFORE);
556 	if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0)
557 		goto bad;
558 
559 	ip = mtod(m, struct ip *);
560 	dst = &sav->sah->saidx.dst;
561 	/* Do the appropriate encapsulation, if necessary */
562 	if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
563 	    dst->sa.sa_family != AF_INET ||	    /* PF mismatch */
564 	    (dst->sa.sa_family == AF_INET &&	    /* Proxy */
565 	     dst->sin.sin_addr.s_addr != INADDR_ANY &&
566 	     dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
567 		/* Fix IPv4 header checksum and length */
568 		ip->ip_len = htons(m->m_pkthdr.len);
569 		ip->ip_sum = 0;
570 		ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
571 		error = ipsec_encap(&m, &sav->sah->saidx);
572 		if (error != 0) {
573 			DPRINTF(("%s: encapsulation for SA %s->%s "
574 			    "SPI 0x%08x failed with error %d\n", __func__,
575 			    ipsec_address(&sav->sah->saidx.src, sbuf,
576 				sizeof(sbuf)),
577 			    ipsec_address(&sav->sah->saidx.dst, dbuf,
578 				sizeof(dbuf)), ntohl(sav->spi), error));
579 			goto bad;
580 		}
581 	}
582 
583 	IPSEC_INIT_CTX(&ctx, &m, sav, dst->sa.sa_family, IPSEC_ENC_AFTER);
584 	if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0)
585 		goto bad;
586 
587 	/*
588 	 * Dispatch to the appropriate IPsec transform logic.  The
589 	 * packet will be returned for transmission after crypto
590 	 * processing, etc. are completed.
591 	 *
592 	 * NB: m & sav are ``passed to caller'' who's reponsible for
593 	 *     for reclaiming their resources.
594 	 */
595 	switch(dst->sa.sa_family) {
596 	case AF_INET:
597 		ip = mtod(m, struct ip *);
598 		i = ip->ip_hl << 2;
599 		off = offsetof(struct ip, ip_p);
600 		break;
601 #ifdef INET6
602 	case AF_INET6:
603 		i = sizeof(struct ip6_hdr);
604 		off = offsetof(struct ip6_hdr, ip6_nxt);
605 		break;
606 #endif /* INET6 */
607 	default:
608 		DPRINTF(("%s: unsupported protocol family %u\n",
609 		    __func__, dst->sa.sa_family));
610 		error = EPFNOSUPPORT;
611 		IPSECSTAT_INC(ips_out_inval);
612 		goto bad;
613 	}
614 	error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
615 	IPSECREQUEST_UNLOCK(isr);
616 	return (error);
617 bad:
618 	if (isr)
619 		IPSECREQUEST_UNLOCK(isr);
620 	if (m)
621 		m_freem(m);
622 	return error;
623 }
624 #endif
625 
626 
627 #ifdef INET6
628 static int
629 in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, const struct in6_addr *ia)
630 {
631 	struct in6_addr ia2;
632 
633 	memcpy(&ia2, &sa->sin6_addr, sizeof(ia2));
634 	if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr))
635 		ia2.s6_addr16[1] = htons(sa->sin6_scope_id);
636 
637 	return IN6_ARE_ADDR_EQUAL(ia, &ia2);
638 }
639 
640 /*
641  * IPsec output logic for IPv6.
642  */
643 int
644 ipsec6_process_packet(struct mbuf *m, struct ipsecrequest *isr)
645 {
646 	char sbuf[INET6_ADDRSTRLEN], dbuf[INET6_ADDRSTRLEN];
647 	struct ipsec_ctx_data ctx;
648 	struct secasindex saidx;
649 	struct secasvar *sav;
650 	struct ip6_hdr *ip6;
651 	int error, i, off;
652 	union sockaddr_union *dst;
653 
654 	IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf"));
655 	IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr"));
656 
657 	IPSECREQUEST_LOCK(isr);		/* insure SA contents don't change */
658 
659 	isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
660 	if (isr == NULL) {
661 		if (error != 0)
662 			goto bad;
663 		return EJUSTRETURN;
664 	}
665 	sav = isr->sav;
666 	dst = &sav->sah->saidx.dst;
667 
668 	IPSEC_INIT_CTX(&ctx, &m, sav, AF_INET6, IPSEC_ENC_BEFORE);
669 	if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0)
670 		goto bad;
671 
672 	ip6 = mtod(m, struct ip6_hdr *);
673 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
674 
675 	/* Do the appropriate encapsulation, if necessary */
676 	if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
677 	    dst->sa.sa_family != AF_INET6 ||        /* PF mismatch */
678 	    ((dst->sa.sa_family == AF_INET6) &&
679 	     (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) &&
680 	     (!in6_sa_equal_addrwithscope(&dst->sin6,
681 				  &ip6->ip6_dst)))) {
682 		if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) {
683 			/* No jumbogram support. */
684 			error = ENXIO;   /*XXX*/
685 			goto bad;
686 		}
687 		error = ipsec_encap(&m, &sav->sah->saidx);
688 		if (error != 0) {
689 			DPRINTF(("%s: encapsulation for SA %s->%s "
690 			    "SPI 0x%08x failed with error %d\n", __func__,
691 			    ipsec_address(&sav->sah->saidx.src, sbuf,
692 				sizeof(sbuf)),
693 			    ipsec_address(&sav->sah->saidx.dst, dbuf,
694 				sizeof(dbuf)), ntohl(sav->spi), error));
695 			goto bad;
696 		}
697 	}
698 
699 	IPSEC_INIT_CTX(&ctx, &m, sav, dst->sa.sa_family, IPSEC_ENC_AFTER);
700 	if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0)
701 		goto bad;
702 
703 	switch(dst->sa.sa_family) {
704 #ifdef INET
705 	case AF_INET:
706 		{
707 		struct ip *ip;
708 		ip = mtod(m, struct ip *);
709 		i = ip->ip_hl << 2;
710 		off = offsetof(struct ip, ip_p);
711 		}
712 		break;
713 #endif /* AF_INET */
714 	case AF_INET6:
715 		i = sizeof(struct ip6_hdr);
716 		off = offsetof(struct ip6_hdr, ip6_nxt);
717 		break;
718 	default:
719 		DPRINTF(("%s: unsupported protocol family %u\n",
720 				 __func__, dst->sa.sa_family));
721 		error = EPFNOSUPPORT;
722 		goto bad;
723 	}
724 	error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
725 	IPSECREQUEST_UNLOCK(isr);
726 	return error;
727 bad:
728 	IPSEC6STAT_INC(ips_out_inval);
729 	if (isr)
730 		IPSECREQUEST_UNLOCK(isr);
731 	if (m)
732 		m_freem(m);
733 	return error;
734 }
735 #endif /*INET6*/
736