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: stable/9/sys/netipsec/ipsec_output.c 264815 2014-04-23 12:05:53Z ae $
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/pfil.h>
48 #include <net/route.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 #endif
65 #include <netinet/in_pcb.h>
66 #ifdef INET6
67 #include <netinet/icmp6.h>
68 #endif
69
70 #include <netipsec/ipsec.h>
71 #ifdef INET6
72 #include <netipsec/ipsec6.h>
73 #endif
74 #include <netipsec/ah_var.h>
75 #include <netipsec/esp_var.h>
76 #include <netipsec/ipcomp_var.h>
77
78 #include <netipsec/xform.h>
79
80 #include <netipsec/key.h>
81 #include <netipsec/keydb.h>
82 #include <netipsec/key_debug.h>
83
84 #include <machine/in_cksum.h>
85
86 #ifdef IPSEC_NAT_T
87 #include <netinet/udp.h>
88 #endif
89
90 #ifdef DEV_ENC
91 #include <net/if_enc.h>
92 #endif
93
94
95 int
ipsec_process_done(struct mbuf * m,struct ipsecrequest * isr)96 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
97 {
98 struct tdb_ident *tdbi;
99 struct m_tag *mtag;
100 struct secasvar *sav;
101 struct secasindex *saidx;
102 int error;
103
104 IPSEC_ASSERT(m != NULL, ("null mbuf"));
105 IPSEC_ASSERT(isr != NULL, ("null ISR"));
106 sav = isr->sav;
107 IPSEC_ASSERT(sav != NULL, ("null SA"));
108 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
109
110 saidx = &sav->sah->saidx;
111 switch (saidx->dst.sa.sa_family) {
112 #ifdef INET
113 case AF_INET:
114 /* Fix the header length, for AH processing. */
115 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
116 break;
117 #endif /* INET */
118 #ifdef INET6
119 case AF_INET6:
120 /* Fix the header length, for AH processing. */
121 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
122 error = ENXIO;
123 goto bad;
124 }
125 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
126 /* No jumbogram support. */
127 error = ENXIO; /*?*/
128 goto bad;
129 }
130 mtod(m, struct ip6_hdr *)->ip6_plen =
131 htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
132 break;
133 #endif /* INET6 */
134 default:
135 DPRINTF(("%s: unknown protocol family %u\n", __func__,
136 saidx->dst.sa.sa_family));
137 error = ENXIO;
138 goto bad;
139 }
140
141 /*
142 * Add a record of what we've done or what needs to be done to the
143 * packet.
144 */
145 mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
146 sizeof(struct tdb_ident), M_NOWAIT);
147 if (mtag == NULL) {
148 DPRINTF(("%s: could not get packet tag\n", __func__));
149 error = ENOMEM;
150 goto bad;
151 }
152
153 tdbi = (struct tdb_ident *)(mtag + 1);
154 tdbi->dst = saidx->dst;
155 tdbi->proto = saidx->proto;
156 tdbi->spi = sav->spi;
157 m_tag_prepend(m, mtag);
158
159 /*
160 * If there's another (bundled) SA to apply, do so.
161 * Note that this puts a burden on the kernel stack size.
162 * If this is a problem we'll need to introduce a queue
163 * to set the packet on so we can unwind the stack before
164 * doing further processing.
165 */
166 if (isr->next) {
167 IPSECSTAT_INC(ips_out_bundlesa);
168 /* XXX-BZ currently only support same AF bundles. */
169 switch (saidx->dst.sa.sa_family) {
170 #ifdef INET
171 case AF_INET:
172 return ipsec4_process_packet(m, isr->next, 0, 0);
173 /* NOTREACHED */
174 #endif
175 #ifdef notyet
176 #ifdef INET6
177 case AF_INET6:
178 /* XXX */
179 ipsec6_output_trans()
180 ipsec6_output_tunnel()
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 m_addr_changed(m);
194
195 /*
196 * We're done with IPsec processing, transmit the packet using the
197 * appropriate network protocol (IP or IPv6). SPD lookup will be
198 * performed again there.
199 */
200 switch (saidx->dst.sa.sa_family) {
201 #ifdef INET
202 struct ip *ip;
203 case AF_INET:
204 ip = mtod(m, struct ip *);
205 ip->ip_len = ntohs(ip->ip_len);
206 ip->ip_off = ntohs(ip->ip_off);
207
208 #ifdef IPSEC_NAT_T
209 /*
210 * If NAT-T is enabled, now that all IPsec processing is done
211 * insert UDP encapsulation header after IP header.
212 */
213 if (sav->natt_type) {
214 const int hlen = (ip->ip_hl << 2);
215 int size, off;
216 struct mbuf *mi;
217 struct udphdr *udp;
218
219 size = sizeof(struct udphdr);
220 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
221 /*
222 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
223 * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
224 * ignoring possible AH mode
225 * non-IKE marker + non-ESP marker
226 * from draft-ietf-ipsec-udp-encaps-00.txt.
227 */
228 size += sizeof(u_int64_t);
229 }
230 mi = m_makespace(m, hlen, size, &off);
231 if (mi == NULL) {
232 DPRINTF(("%s: m_makespace for udphdr failed\n",
233 __func__));
234 error = ENOBUFS;
235 goto bad;
236 }
237
238 udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
239 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
240 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
241 else
242 udp->uh_sport =
243 KEY_PORTFROMSADDR(&sav->sah->saidx.src);
244 udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
245 udp->uh_sum = 0;
246 udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
247 ip->ip_len = m->m_pkthdr.len;
248 ip->ip_p = IPPROTO_UDP;
249
250 if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
251 *(u_int64_t *)(udp + 1) = 0;
252 }
253 #endif /* IPSEC_NAT_T */
254
255 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
256 #endif /* INET */
257 #ifdef INET6
258 case AF_INET6:
259 /*
260 * We don't need massage, IPv6 header fields are always in
261 * net endian.
262 */
263 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
264 #endif /* INET6 */
265 }
266 panic("ipsec_process_done");
267 bad:
268 m_freem(m);
269 return (error);
270 }
271
272 static struct ipsecrequest *
ipsec_nextisr(struct mbuf * m,struct ipsecrequest * isr,int af,struct secasindex * saidx,int * error)273 ipsec_nextisr(
274 struct mbuf *m,
275 struct ipsecrequest *isr,
276 int af,
277 struct secasindex *saidx,
278 int *error
279 )
280 {
281 #define IPSEC_OSTAT(name) do { \
282 if (isr->saidx.proto == IPPROTO_ESP) \
283 ESPSTAT_INC(esps_##name); \
284 else if (isr->saidx.proto == IPPROTO_AH)\
285 AHSTAT_INC(ahs_##name); \
286 else \
287 IPCOMPSTAT_INC(ipcomps_##name); \
288 } while (0)
289 struct secasvar *sav;
290
291 IPSECREQUEST_LOCK_ASSERT(isr);
292
293 IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
294 ("invalid address family %u", af));
295 again:
296 /*
297 * Craft SA index to search for proper SA. Note that
298 * we only fillin unspecified SA peers for transport
299 * mode; for tunnel mode they must already be filled in.
300 */
301 *saidx = isr->saidx;
302 if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
303 /* Fillin unspecified SA peers only for transport mode */
304 if (af == AF_INET) {
305 struct sockaddr_in *sin;
306 struct ip *ip = mtod(m, struct ip *);
307
308 if (saidx->src.sa.sa_len == 0) {
309 sin = &saidx->src.sin;
310 sin->sin_len = sizeof(*sin);
311 sin->sin_family = AF_INET;
312 sin->sin_port = IPSEC_PORT_ANY;
313 sin->sin_addr = ip->ip_src;
314 }
315 if (saidx->dst.sa.sa_len == 0) {
316 sin = &saidx->dst.sin;
317 sin->sin_len = sizeof(*sin);
318 sin->sin_family = AF_INET;
319 sin->sin_port = IPSEC_PORT_ANY;
320 sin->sin_addr = ip->ip_dst;
321 }
322 } else {
323 struct sockaddr_in6 *sin6;
324 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
325
326 if (saidx->src.sin6.sin6_len == 0) {
327 sin6 = (struct sockaddr_in6 *)&saidx->src;
328 sin6->sin6_len = sizeof(*sin6);
329 sin6->sin6_family = AF_INET6;
330 sin6->sin6_port = IPSEC_PORT_ANY;
331 sin6->sin6_addr = ip6->ip6_src;
332 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
333 /* fix scope id for comparing SPD */
334 sin6->sin6_addr.s6_addr16[1] = 0;
335 sin6->sin6_scope_id =
336 ntohs(ip6->ip6_src.s6_addr16[1]);
337 }
338 }
339 if (saidx->dst.sin6.sin6_len == 0) {
340 sin6 = (struct sockaddr_in6 *)&saidx->dst;
341 sin6->sin6_len = sizeof(*sin6);
342 sin6->sin6_family = AF_INET6;
343 sin6->sin6_port = IPSEC_PORT_ANY;
344 sin6->sin6_addr = ip6->ip6_dst;
345 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
346 /* fix scope id for comparing SPD */
347 sin6->sin6_addr.s6_addr16[1] = 0;
348 sin6->sin6_scope_id =
349 ntohs(ip6->ip6_dst.s6_addr16[1]);
350 }
351 }
352 }
353 }
354
355 /*
356 * Lookup SA and validate it.
357 */
358 *error = key_checkrequest(isr, saidx);
359 if (*error != 0) {
360 /*
361 * IPsec processing is required, but no SA found.
362 * I assume that key_acquire() had been called
363 * to get/establish the SA. Here I discard
364 * this packet because it is responsibility for
365 * upper layer to retransmit the packet.
366 */
367 IPSECSTAT_INC(ips_out_nosa);
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 #ifdef INET
420 /*
421 * IPsec output logic for IPv4.
422 */
423 int
ipsec4_process_packet(struct mbuf * m,struct ipsecrequest * isr,int flags,int tunalready)424 ipsec4_process_packet(
425 struct mbuf *m,
426 struct ipsecrequest *isr,
427 int flags,
428 int tunalready)
429 {
430 struct secasindex saidx;
431 struct secasvar *sav;
432 struct ip *ip;
433 int error, i, off;
434
435 IPSEC_ASSERT(m != NULL, ("null mbuf"));
436 IPSEC_ASSERT(isr != NULL, ("null isr"));
437
438 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */
439
440 isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
441 if (isr == NULL) {
442 if (error != 0)
443 goto bad;
444 return EJUSTRETURN;
445 }
446
447 sav = isr->sav;
448
449 #ifdef DEV_ENC
450 encif->if_opackets++;
451 encif->if_obytes += m->m_pkthdr.len;
452
453 /* pass the mbuf to enc0 for bpf processing */
454 ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
455 /* pass the mbuf to enc0 for packet filtering */
456 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
457 goto bad;
458 #endif
459
460 if (!tunalready) {
461 union sockaddr_union *dst = &sav->sah->saidx.dst;
462 int setdf;
463
464 /*
465 * Collect IP_DF state from the outer header.
466 */
467 if (dst->sa.sa_family == AF_INET) {
468 if (m->m_len < sizeof (struct ip) &&
469 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
470 error = ENOBUFS;
471 goto bad;
472 }
473 ip = mtod(m, struct ip *);
474 /* Honor system-wide control of how to handle IP_DF */
475 switch (V_ip4_ipsec_dfbit) {
476 case 0: /* clear in outer header */
477 case 1: /* set in outer header */
478 setdf = V_ip4_ipsec_dfbit;
479 break;
480 default: /* propagate to outer header */
481 setdf = ntohs(ip->ip_off & IP_DF);
482 break;
483 }
484 } else {
485 ip = NULL; /* keep compiler happy */
486 setdf = 0;
487 }
488 /* Do the appropriate encapsulation, if necessary */
489 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
490 dst->sa.sa_family != AF_INET || /* PF mismatch */
491 #if 0
492 (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
493 sav->tdb_xform->xf_type == XF_IP4 || /* ditto */
494 #endif
495 (dst->sa.sa_family == AF_INET && /* Proxy */
496 dst->sin.sin_addr.s_addr != INADDR_ANY &&
497 dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
498 struct mbuf *mp;
499
500 /* Fix IPv4 header checksum and length */
501 if (m->m_len < sizeof (struct ip) &&
502 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
503 error = ENOBUFS;
504 goto bad;
505 }
506 ip = mtod(m, struct ip *);
507 ip->ip_len = htons(m->m_pkthdr.len);
508 ip->ip_sum = 0;
509 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
510
511 /* Encapsulate the packet */
512 error = ipip_output(m, isr, &mp, 0, 0);
513 if (mp == NULL && !error) {
514 /* Should never happen. */
515 DPRINTF(("%s: ipip_output returns no mbuf and "
516 "no error!", __func__));
517 error = EFAULT;
518 }
519 if (error) {
520 if (mp) {
521 /* XXX: Should never happen! */
522 m_freem(mp);
523 }
524 m = NULL; /* ipip_output() already freed it */
525 goto bad;
526 }
527 m = mp, mp = NULL;
528 /*
529 * ipip_output clears IP_DF in the new header. If
530 * we need to propagate IP_DF from the outer header,
531 * then we have to do it here.
532 *
533 * XXX shouldn't assume what ipip_output does.
534 */
535 if (dst->sa.sa_family == AF_INET && setdf) {
536 if (m->m_len < sizeof (struct ip) &&
537 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
538 error = ENOBUFS;
539 goto bad;
540 }
541 ip = mtod(m, struct ip *);
542 ip->ip_off = ntohs(ip->ip_off);
543 ip->ip_off |= IP_DF;
544 ip->ip_off = htons(ip->ip_off);
545 }
546 }
547 }
548
549 #ifdef DEV_ENC
550 /* pass the mbuf to enc0 for bpf processing */
551 ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER);
552 /* pass the mbuf to enc0 for packet filtering */
553 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
554 goto bad;
555 #endif
556
557 /*
558 * Dispatch to the appropriate IPsec transform logic. The
559 * packet will be returned for transmission after crypto
560 * processing, etc. are completed. For encapsulation we
561 * bypass this call because of the explicit call done above
562 * (necessary to deal with IP_DF handling for IPv4).
563 *
564 * NB: m & sav are ``passed to caller'' who's reponsible for
565 * for reclaiming their resources.
566 */
567 if (sav->tdb_xform->xf_type != XF_IP4) {
568 ip = mtod(m, struct ip *);
569 i = ip->ip_hl << 2;
570 off = offsetof(struct ip, ip_p);
571 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
572 } else {
573 error = ipsec_process_done(m, isr);
574 }
575 IPSECREQUEST_UNLOCK(isr);
576 return error;
577 bad:
578 if (isr)
579 IPSECREQUEST_UNLOCK(isr);
580 if (m)
581 m_freem(m);
582 return error;
583 }
584 #endif
585
586 #ifdef INET6
587 /*
588 * Chop IP6 header from the payload.
589 */
590 static struct mbuf *
ipsec6_splithdr(struct mbuf * m)591 ipsec6_splithdr(struct mbuf *m)
592 {
593 struct mbuf *mh;
594 struct ip6_hdr *ip6;
595 int hlen;
596
597 IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
598 ("first mbuf too short, len %u", m->m_len));
599 ip6 = mtod(m, struct ip6_hdr *);
600 hlen = sizeof(struct ip6_hdr);
601 if (m->m_len > hlen) {
602 MGETHDR(mh, M_DONTWAIT, MT_DATA);
603 if (!mh) {
604 m_freem(m);
605 return NULL;
606 }
607 M_MOVE_PKTHDR(mh, m);
608 MH_ALIGN(mh, hlen);
609 m->m_len -= hlen;
610 m->m_data += hlen;
611 mh->m_next = m;
612 m = mh;
613 m->m_len = hlen;
614 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
615 } else if (m->m_len < hlen) {
616 m = m_pullup(m, hlen);
617 if (!m)
618 return NULL;
619 }
620 return m;
621 }
622
623 /*
624 * IPsec output logic for IPv6, transport mode.
625 */
626 int
ipsec6_output_trans(struct ipsec_output_state * state,u_char * nexthdrp,struct mbuf * mprev,struct secpolicy * sp,int flags,int * tun)627 ipsec6_output_trans(
628 struct ipsec_output_state *state,
629 u_char *nexthdrp,
630 struct mbuf *mprev,
631 struct secpolicy *sp,
632 int flags,
633 int *tun)
634 {
635 struct ipsecrequest *isr;
636 struct secasindex saidx;
637 int error = 0;
638 struct mbuf *m;
639
640 IPSEC_ASSERT(state != NULL, ("null state"));
641 IPSEC_ASSERT(state->m != NULL, ("null m"));
642 IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
643 IPSEC_ASSERT(mprev != NULL, ("null mprev"));
644 IPSEC_ASSERT(sp != NULL, ("null sp"));
645 IPSEC_ASSERT(tun != NULL, ("null tun"));
646
647 KEYDEBUG(KEYDEBUG_IPSEC_DATA,
648 printf("%s: applied SP\n", __func__);
649 kdebug_secpolicy(sp));
650
651 isr = sp->req;
652 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
653 /* the rest will be handled by ipsec6_output_tunnel() */
654 *tun = 1; /* need tunnel-mode processing */
655 return 0;
656 }
657
658 *tun = 0;
659 m = state->m;
660
661 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */
662 isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
663 if (isr == NULL) {
664 if (error != 0) {
665 #ifdef notdef
666 /* XXX should notification be done for all errors ? */
667 /*
668 * Notify the fact that the packet is discarded
669 * to ourselves. I believe this is better than
670 * just silently discarding. (jinmei@kame.net)
671 * XXX: should we restrict the error to TCP packets?
672 * XXX: should we directly notify sockets via
673 * pfctlinputs?
674 */
675 icmp6_error(m, ICMP6_DST_UNREACH,
676 ICMP6_DST_UNREACH_ADMIN, 0);
677 m = NULL; /* NB: icmp6_error frees mbuf */
678 #endif
679 goto bad;
680 }
681 return EJUSTRETURN;
682 }
683
684 error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
685 sizeof (struct ip6_hdr),
686 offsetof(struct ip6_hdr,
687 ip6_nxt));
688 IPSECREQUEST_UNLOCK(isr);
689 return error;
690 bad:
691 if (isr)
692 IPSECREQUEST_UNLOCK(isr);
693 if (m)
694 m_freem(m);
695 state->m = NULL;
696 return error;
697 }
698
699 static int
ipsec6_encapsulate(struct mbuf * m,struct secasvar * sav)700 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
701 {
702 struct ip6_hdr *oip6;
703 struct ip6_hdr *ip6;
704 size_t plen;
705
706 /* can't tunnel between different AFs */
707 if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
708 sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
709 m_freem(m);
710 return EINVAL;
711 }
712 IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr),
713 ("mbuf wrong size; len %u", m->m_len));
714
715
716 /*
717 * grow the mbuf to accomodate the new IPv6 header.
718 */
719 plen = m->m_pkthdr.len;
720 if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
721 struct mbuf *n;
722 MGET(n, M_DONTWAIT, MT_DATA);
723 if (!n) {
724 m_freem(m);
725 return ENOBUFS;
726 }
727 n->m_len = sizeof(struct ip6_hdr);
728 n->m_next = m->m_next;
729 m->m_next = n;
730 m->m_pkthdr.len += sizeof(struct ip6_hdr);
731 oip6 = mtod(n, struct ip6_hdr *);
732 } else {
733 m->m_next->m_len += sizeof(struct ip6_hdr);
734 m->m_next->m_data -= sizeof(struct ip6_hdr);
735 m->m_pkthdr.len += sizeof(struct ip6_hdr);
736 oip6 = mtod(m->m_next, struct ip6_hdr *);
737 }
738 ip6 = mtod(m, struct ip6_hdr *);
739 bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
740
741 /* Fake link-local scope-class addresses */
742 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
743 oip6->ip6_src.s6_addr16[1] = 0;
744 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
745 oip6->ip6_dst.s6_addr16[1] = 0;
746
747 /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
748 /* ECN consideration. */
749 ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
750 if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
751 ip6->ip6_plen = htons(plen);
752 else {
753 /* ip6->ip6_plen will be updated in ip6_output() */
754 }
755 ip6->ip6_nxt = IPPROTO_IPV6;
756 ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr;
757 ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr;
758 ip6->ip6_hlim = IPV6_DEFHLIM;
759
760 /* XXX Should ip6_src be updated later ? */
761
762 return 0;
763 }
764
765 /*
766 * IPsec output logic for IPv6, tunnel mode.
767 */
768 int
ipsec6_output_tunnel(struct ipsec_output_state * state,struct secpolicy * sp,int flags)769 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
770 {
771 struct ip6_hdr *ip6;
772 struct ipsecrequest *isr;
773 struct secasindex saidx;
774 int error;
775 struct sockaddr_in6 *dst6;
776 struct mbuf *m;
777
778 IPSEC_ASSERT(state != NULL, ("null state"));
779 IPSEC_ASSERT(state->m != NULL, ("null m"));
780 IPSEC_ASSERT(sp != NULL, ("null sp"));
781
782 KEYDEBUG(KEYDEBUG_IPSEC_DATA,
783 printf("%s: applied SP\n", __func__);
784 kdebug_secpolicy(sp));
785
786 m = state->m;
787 /*
788 * transport mode ipsec (before the 1st tunnel mode) is already
789 * processed by ipsec6_output_trans().
790 */
791 for (isr = sp->req; isr; isr = isr->next) {
792 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
793 break;
794 }
795
796 IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */
797 isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
798 if (isr == NULL) {
799 if (error != 0)
800 goto bad;
801 return EJUSTRETURN;
802 }
803
804 #ifdef DEV_ENC
805 encif->if_opackets++;
806 encif->if_obytes += m->m_pkthdr.len;
807
808 /* pass the mbuf to enc0 for bpf processing */
809 ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
810 /* pass the mbuf to enc0 for packet filtering */
811 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
812 goto bad;
813 #endif
814
815 /*
816 * There may be the case that SA status will be changed when
817 * we are refering to one. So calling splsoftnet().
818 */
819 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
820 /*
821 * build IPsec tunnel.
822 */
823 /* XXX should be processed with other familiy */
824 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
825 ipseclog((LOG_ERR, "%s: family mismatched between "
826 "inner and outer, spi=%u\n", __func__,
827 ntohl(isr->sav->spi)));
828 IPSEC6STAT_INC(ips_out_inval);
829 error = EAFNOSUPPORT;
830 goto bad;
831 }
832
833 m = ipsec6_splithdr(m);
834 if (!m) {
835 IPSEC6STAT_INC(ips_out_nomem);
836 error = ENOMEM;
837 goto bad;
838 }
839 error = ipsec6_encapsulate(m, isr->sav);
840 if (error) {
841 m = NULL;
842 goto bad;
843 }
844 ip6 = mtod(m, struct ip6_hdr *);
845
846 state->ro =
847 (struct route *)&isr->sav->sah->route_cache.sin6_route;
848 state->dst = (struct sockaddr *)&state->ro->ro_dst;
849 dst6 = (struct sockaddr_in6 *)state->dst;
850 if (state->ro->ro_rt
851 && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
852 || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
853 RTFREE(state->ro->ro_rt);
854 state->ro->ro_rt = NULL;
855 }
856 if (state->ro->ro_rt == NULL) {
857 bzero(dst6, sizeof(*dst6));
858 dst6->sin6_family = AF_INET6;
859 dst6->sin6_len = sizeof(*dst6);
860 dst6->sin6_addr = ip6->ip6_dst;
861 rtalloc_ign_fib(state->ro, 0UL, M_GETFIB(m));
862 }
863 if (state->ro->ro_rt == NULL) {
864 IP6STAT_INC(ip6s_noroute);
865 IPSEC6STAT_INC(ips_out_noroute);
866 error = EHOSTUNREACH;
867 goto bad;
868 }
869
870 /* adjust state->dst if tunnel endpoint is offlink */
871 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY)
872 state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
873 }
874
875 m = ipsec6_splithdr(m);
876 if (!m) {
877 IPSEC6STAT_INC(ips_out_nomem);
878 error = ENOMEM;
879 goto bad;
880 }
881 ip6 = mtod(m, struct ip6_hdr *);
882
883 #ifdef DEV_ENC
884 /* pass the mbuf to enc0 for bpf processing */
885 ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER);
886 /* pass the mbuf to enc0 for packet filtering */
887 if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
888 goto bad;
889 #endif
890
891 error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
892 sizeof (struct ip6_hdr),
893 offsetof(struct ip6_hdr, ip6_nxt));
894 IPSECREQUEST_UNLOCK(isr);
895 return error;
896 bad:
897 if (isr)
898 IPSECREQUEST_UNLOCK(isr);
899 if (m)
900 m_freem(m);
901 state->m = NULL;
902 return error;
903 }
904 #endif /*INET6*/
905