1 /* $FreeBSD: releng/11.0/sys/netipsec/ipsec_input.c 291292 2015-11-25 07:31:59Z ae $ */
2 /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */
3 /*-
4 * The authors of this code are John Ioannidis (ji@tla.org),
5 * Angelos D. Keromytis (kermit@csd.uch.gr) and
6 * Niels Provos (provos@physnet.uni-hamburg.de).
7 *
8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
9 * in November 1995.
10 *
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
13 *
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
15 * and Niels Provos.
16 *
17 * Additional features in 1999 by Angelos D. Keromytis.
18 *
19 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
20 * Angelos D. Keromytis and Niels Provos.
21 * Copyright (c) 2001, Angelos D. Keromytis.
22 *
23 * Permission to use, copy, and modify this software with or without fee
24 * is hereby granted, provided that this entire notice is included in
25 * all copies of any software which is or includes a copy or
26 * modification of this software.
27 * You may use this code under the GNU public license if you so wish. Please
28 * contribute changes back to the authors under this freer than GPL license
29 * so that we may further the use of strong encryption without limitations to
30 * all.
31 *
32 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
33 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
34 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
35 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
36 * PURPOSE.
37 */
38
39 /*
40 * IPsec input processing.
41 */
42
43 #include "opt_inet.h"
44 #include "opt_inet6.h"
45 #include "opt_ipsec.h"
46
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/malloc.h>
50 #include <sys/mbuf.h>
51 #include <sys/domain.h>
52 #include <sys/protosw.h>
53 #include <sys/socket.h>
54 #include <sys/errno.h>
55 #include <sys/hhook.h>
56 #include <sys/syslog.h>
57
58 #include <net/if.h>
59 #include <net/if_var.h>
60 #include <net/if_enc.h>
61 #include <net/netisr.h>
62 #include <net/vnet.h>
63
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #include <netinet/ip.h>
67 #include <netinet/ip_var.h>
68 #include <netinet/in_var.h>
69
70 #include <netinet/ip6.h>
71 #ifdef INET6
72 #include <netinet6/ip6_var.h>
73 #endif
74 #include <netinet/in_pcb.h>
75 #ifdef INET6
76 #include <netinet/icmp6.h>
77 #endif
78
79 #include <netipsec/ipsec.h>
80 #ifdef INET6
81 #include <netipsec/ipsec6.h>
82 #endif
83 #include <netipsec/ah_var.h>
84 #include <netipsec/esp.h>
85 #include <netipsec/esp_var.h>
86 #include <netipsec/ipcomp_var.h>
87
88 #include <netipsec/key.h>
89 #include <netipsec/keydb.h>
90
91 #include <netipsec/xform.h>
92 #include <netinet6/ip6protosw.h>
93
94 #include <machine/in_cksum.h>
95 #include <machine/stdarg.h>
96
97
98 #define IPSEC_ISTAT(proto, name) do { \
99 if ((proto) == IPPROTO_ESP) \
100 ESPSTAT_INC(esps_##name); \
101 else if ((proto) == IPPROTO_AH) \
102 AHSTAT_INC(ahs_##name); \
103 else \
104 IPCOMPSTAT_INC(ipcomps_##name); \
105 } while (0)
106
107 #ifdef INET
108 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
109 #endif
110
111 /*
112 * ipsec_common_input gets called when an IPsec-protected packet
113 * is received by IPv4 or IPv6. Its job is to find the right SA
114 * and call the appropriate transform. The transform callback
115 * takes care of further processing (like ingress filtering).
116 */
117 int
118 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
119 {
120 char buf[INET6_ADDRSTRLEN];
121 union sockaddr_union dst_address;
122 struct secasvar *sav;
123 u_int32_t spi;
124 int error;
125 #ifdef INET
126 #ifdef IPSEC_NAT_T
127 struct m_tag *tag;
128 #endif
129 #endif
130
131 IPSEC_ISTAT(sproto, input);
132
133 IPSEC_ASSERT(m != NULL, ("null packet"));
134
135 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
136 sproto == IPPROTO_IPCOMP,
137 ("unexpected security protocol %u", sproto));
138
139 if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
140 (sproto == IPPROTO_AH && !V_ah_enable) ||
141 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
142 m_freem(m);
143 IPSEC_ISTAT(sproto, pdrops);
144 return EOPNOTSUPP;
145 }
146
147 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
148 m_freem(m);
149 IPSEC_ISTAT(sproto, hdrops);
150 DPRINTF(("%s: packet too small\n", __func__));
151 return EINVAL;
152 }
153
154 /* Retrieve the SPI from the relevant IPsec header */
155 if (sproto == IPPROTO_ESP)
156 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
157 else if (sproto == IPPROTO_AH)
158 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
159 (caddr_t) &spi);
160 else if (sproto == IPPROTO_IPCOMP) {
161 u_int16_t cpi;
162 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
163 (caddr_t) &cpi);
164 spi = ntohl(htons(cpi));
165 }
166
167 /*
168 * Find the SA and (indirectly) call the appropriate
169 * kernel crypto routine. The resulting mbuf chain is a valid
170 * IP packet ready to go through input processing.
171 */
172 bzero(&dst_address, sizeof (dst_address));
173 dst_address.sa.sa_family = af;
174 switch (af) {
175 #ifdef INET
176 case AF_INET:
177 dst_address.sin.sin_len = sizeof(struct sockaddr_in);
178 m_copydata(m, offsetof(struct ip, ip_dst),
179 sizeof(struct in_addr),
180 (caddr_t) &dst_address.sin.sin_addr);
181 #ifdef IPSEC_NAT_T
182 /* Find the source port for NAT-T; see udp*_espdecap. */
183 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL);
184 if (tag != NULL)
185 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1];
186 #endif /* IPSEC_NAT_T */
187 break;
188 #endif /* INET */
189 #ifdef INET6
190 case AF_INET6:
191 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
192 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
193 sizeof(struct in6_addr),
194 (caddr_t) &dst_address.sin6.sin6_addr);
195 /* We keep addresses in SADB without embedded scope id */
196 if (IN6_IS_SCOPE_LINKLOCAL(&dst_address.sin6.sin6_addr)) {
197 /* XXX: sa6_recoverscope() */
198 dst_address.sin6.sin6_scope_id =
199 ntohs(dst_address.sin6.sin6_addr.s6_addr16[1]);
200 dst_address.sin6.sin6_addr.s6_addr16[1] = 0;
201 }
202 break;
203 #endif /* INET6 */
204 default:
205 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
206 m_freem(m);
207 IPSEC_ISTAT(sproto, nopf);
208 return EPFNOSUPPORT;
209 }
210
211 /* NB: only pass dst since key_allocsa follows RFC2401 */
212 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
213 if (sav == NULL) {
214 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
215 __func__, ipsec_address(&dst_address, buf, sizeof(buf)),
216 (u_long) ntohl(spi), sproto));
217 IPSEC_ISTAT(sproto, notdb);
218 m_freem(m);
219 return ENOENT;
220 }
221
222 if (sav->tdb_xform == NULL) {
223 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
224 __func__, ipsec_address(&dst_address, buf, sizeof(buf)),
225 (u_long) ntohl(spi), sproto));
226 IPSEC_ISTAT(sproto, noxform);
227 KEY_FREESAV(&sav);
228 m_freem(m);
229 return ENXIO;
230 }
231
232 /*
233 * Call appropriate transform and return -- callback takes care of
234 * everything else.
235 */
236 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
237 KEY_FREESAV(&sav);
238 return error;
239 }
240
241 #ifdef INET
242 int
243 ah4_input(struct mbuf **mp, int *offp, int proto)
244 {
245 struct mbuf *m;
246 int off;
247
248 m = *mp;
249 off = *offp;
250 *mp = NULL;
251
252 ipsec_common_input(m, off, offsetof(struct ip, ip_p),
253 AF_INET, IPPROTO_AH);
254 return (IPPROTO_DONE);
255 }
256 void
257 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
258 {
259 if (sa->sa_family == AF_INET &&
260 sa->sa_len == sizeof(struct sockaddr_in))
261 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
262 }
263
264 int
265 esp4_input(struct mbuf **mp, int *offp, int proto)
266 {
267 struct mbuf *m;
268 int off;
269
270 m = *mp;
271 off = *offp;
272 mp = NULL;
273
274 ipsec_common_input(m, off, offsetof(struct ip, ip_p),
275 AF_INET, IPPROTO_ESP);
276 return (IPPROTO_DONE);
277 }
278
279 void
280 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
281 {
282 if (sa->sa_family == AF_INET &&
283 sa->sa_len == sizeof(struct sockaddr_in))
284 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
285 }
286
287 int
288 ipcomp4_input(struct mbuf **mp, int *offp, int proto)
289 {
290 struct mbuf *m;
291 int off;
292
293 m = *mp;
294 off = *offp;
295 mp = NULL;
296
297 ipsec_common_input(m, off, offsetof(struct ip, ip_p),
298 AF_INET, IPPROTO_IPCOMP);
299 return (IPPROTO_DONE);
300 }
301
302 /*
303 * IPsec input callback for INET protocols.
304 * This routine is called as the transform callback.
305 * Takes care of filtering and other sanity checks on
306 * the processed packet.
307 */
308 int
309 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip,
310 int protoff)
311 {
312 char buf[INET6_ADDRSTRLEN];
313 struct ipsec_ctx_data ctx;
314 int prot, af, sproto, isr_prot;
315 struct ip *ip;
316 struct m_tag *mtag;
317 struct tdb_ident *tdbi;
318 struct secasindex *saidx;
319 int error;
320 #ifdef INET6
321 #ifdef notyet
322 char ip6buf[INET6_ADDRSTRLEN];
323 #endif
324 #endif
325
326 IPSEC_ASSERT(m != NULL, ("null mbuf"));
327 IPSEC_ASSERT(sav != NULL, ("null SA"));
328 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
329 saidx = &sav->sah->saidx;
330 af = saidx->dst.sa.sa_family;
331 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
332 sproto = saidx->proto;
333 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
334 sproto == IPPROTO_IPCOMP,
335 ("unexpected security protocol %u", sproto));
336
337 /* Sanity check */
338 if (m == NULL) {
339 DPRINTF(("%s: null mbuf", __func__));
340 IPSEC_ISTAT(sproto, badkcr);
341 KEY_FREESAV(&sav);
342 return EINVAL;
343 }
344
345 if (skip != 0) {
346 /*
347 * Fix IPv4 header
348 * XXXGL: do we need this entire block?
349 */
350 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
351 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
352 __func__, ipsec_address(&sav->sah->saidx.dst,
353 buf, sizeof(buf)), (u_long) ntohl(sav->spi)));
354 IPSEC_ISTAT(sproto, hdrops);
355 error = ENOBUFS;
356 goto bad;
357 }
358
359 ip = mtod(m, struct ip *);
360 ip->ip_len = htons(m->m_pkthdr.len);
361 ip->ip_sum = 0;
362 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
363 } else {
364 ip = mtod(m, struct ip *);
365 }
366 prot = ip->ip_p;
367
368 IPSEC_INIT_CTX(&ctx, &m, sav, AF_INET, IPSEC_ENC_BEFORE);
369 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0)
370 goto bad;
371 ip = mtod(m, struct ip *);
372
373 /* IP-in-IP encapsulation */
374 if (prot == IPPROTO_IPIP &&
375 saidx->mode != IPSEC_MODE_TRANSPORT) {
376
377 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
378 IPSEC_ISTAT(sproto, hdrops);
379 error = EINVAL;
380 goto bad;
381 }
382 /* enc0: strip outer IPv4 header */
383 m_striphdr(m, 0, ip->ip_hl << 2);
384
385 #ifdef notyet
386 /* XXX PROXY address isn't recorded in SAH */
387 /*
388 * Check that the inner source address is the same as
389 * the proxy address, if available.
390 */
391 if ((saidx->proxy.sa.sa_family == AF_INET &&
392 saidx->proxy.sin.sin_addr.s_addr !=
393 INADDR_ANY &&
394 ipn.ip_src.s_addr !=
395 saidx->proxy.sin.sin_addr.s_addr) ||
396 (saidx->proxy.sa.sa_family != AF_INET &&
397 saidx->proxy.sa.sa_family != 0)) {
398
399 DPRINTF(("%s: inner source address %s doesn't "
400 "correspond to expected proxy source %s, "
401 "SA %s/%08lx\n", __func__,
402 inet_ntoa4(ipn.ip_src),
403 ipsp_address(saidx->proxy),
404 ipsp_address(saidx->dst),
405 (u_long) ntohl(sav->spi)));
406
407 IPSEC_ISTAT(sproto, pdrops);
408 error = EACCES;
409 goto bad;
410 }
411 #endif /* notyet */
412 }
413 #ifdef INET6
414 /* IPv6-in-IP encapsulation. */
415 else if (prot == IPPROTO_IPV6 &&
416 saidx->mode != IPSEC_MODE_TRANSPORT) {
417
418 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
419 IPSEC_ISTAT(sproto, hdrops);
420 error = EINVAL;
421 goto bad;
422 }
423 /* enc0: strip IPv4 header, keep IPv6 header only */
424 m_striphdr(m, 0, ip->ip_hl << 2);
425 #ifdef notyet
426 /*
427 * Check that the inner source address is the same as
428 * the proxy address, if available.
429 */
430 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
431 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
432 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
433 &saidx->proxy.sin6.sin6_addr)) ||
434 (saidx->proxy.sa.sa_family != AF_INET6 &&
435 saidx->proxy.sa.sa_family != 0)) {
436
437 DPRINTF(("%s: inner source address %s doesn't "
438 "correspond to expected proxy source %s, "
439 "SA %s/%08lx\n", __func__,
440 ip6_sprintf(ip6buf, &ip6n.ip6_src),
441 ipsec_address(&saidx->proxy),
442 ipsec_address(&saidx->dst),
443 (u_long) ntohl(sav->spi)));
444
445 IPSEC_ISTAT(sproto, pdrops);
446 error = EACCES;
447 goto bad;
448 }
449 #endif /* notyet */
450 }
451 #endif /* INET6 */
452 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) {
453 /*
454 * When mode is wildcard, inner protocol is IPv6 and
455 * we have no INET6 support - drop this packet a bit later.
456 * In other cases we assume transport mode and outer
457 * header was already stripped in xform_xxx_cb.
458 */
459 prot = IPPROTO_IPIP;
460 }
461
462 /*
463 * Record what we've done to the packet (under what SA it was
464 * processed).
465 */
466 if (sproto != IPPROTO_IPCOMP) {
467 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
468 sizeof(struct tdb_ident), M_NOWAIT);
469 if (mtag == NULL) {
470 DPRINTF(("%s: failed to get tag\n", __func__));
471 IPSEC_ISTAT(sproto, hdrops);
472 error = ENOMEM;
473 goto bad;
474 }
475
476 tdbi = (struct tdb_ident *)(mtag + 1);
477 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
478 tdbi->proto = sproto;
479 tdbi->spi = sav->spi;
480 /* Cache those two for enc(4) in xform_ipip. */
481 tdbi->alg_auth = sav->alg_auth;
482 tdbi->alg_enc = sav->alg_enc;
483
484 m_tag_prepend(m, mtag);
485 }
486
487 key_sa_recordxfer(sav, m); /* record data transfer */
488
489 /*
490 * In transport mode requeue decrypted mbuf back to IPv4 protocol
491 * handler. This is necessary to correctly expose rcvif.
492 */
493 if (saidx->mode == IPSEC_MODE_TRANSPORT)
494 prot = IPPROTO_IPIP;
495 /*
496 * Re-dispatch via software interrupt.
497 */
498 switch (prot) {
499 case IPPROTO_IPIP:
500 isr_prot = NETISR_IP;
501 af = AF_INET;
502 break;
503 #ifdef INET6
504 case IPPROTO_IPV6:
505 isr_prot = NETISR_IPV6;
506 af = AF_INET6;
507 break;
508 #endif
509 default:
510 DPRINTF(("%s: cannot handle inner ip proto %d\n",
511 __func__, prot));
512 IPSEC_ISTAT(sproto, nopf);
513 error = EPFNOSUPPORT;
514 goto bad;
515 }
516
517 IPSEC_INIT_CTX(&ctx, &m, sav, af, IPSEC_ENC_AFTER);
518 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0)
519 goto bad;
520 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m);
521 if (error) {
522 IPSEC_ISTAT(sproto, qfull);
523 DPRINTF(("%s: queue full; proto %u packet dropped\n",
524 __func__, sproto));
525 return error;
526 }
527 return 0;
528 bad:
529 m_freem(m);
530 return error;
531 }
532
533 void
534 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
535 {
536 /* XXX nothing just yet */
537 }
538 #endif /* INET */
539
540 #ifdef INET6
541 /* IPv6 AH wrapper. */
542 int
543 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
544 {
545 int l = 0;
546 int protoff;
547 struct ip6_ext ip6e;
548
549 if (*offp < sizeof(struct ip6_hdr)) {
550 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
551 return IPPROTO_DONE;
552 } else if (*offp == sizeof(struct ip6_hdr)) {
553 protoff = offsetof(struct ip6_hdr, ip6_nxt);
554 } else {
555 /* Chase down the header chain... */
556 protoff = sizeof(struct ip6_hdr);
557
558 do {
559 protoff += l;
560 m_copydata(*mp, protoff, sizeof(ip6e),
561 (caddr_t) &ip6e);
562
563 if (ip6e.ip6e_nxt == IPPROTO_AH)
564 l = (ip6e.ip6e_len + 2) << 2;
565 else
566 l = (ip6e.ip6e_len + 1) << 3;
567 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
568 } while (protoff + l < *offp);
569
570 /* Malformed packet check */
571 if (protoff + l != *offp) {
572 DPRINTF(("%s: bad packet header chain, protoff %u, "
573 "l %u, off %u\n", __func__, protoff, l, *offp));
574 IPSEC_ISTAT(proto, hdrops);
575 m_freem(*mp);
576 *mp = NULL;
577 return IPPROTO_DONE;
578 }
579 protoff += offsetof(struct ip6_ext, ip6e_nxt);
580 }
581 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
582 return IPPROTO_DONE;
583 }
584
585 /*
586 * IPsec input callback, called by the transform callback. Takes care of
587 * filtering and other sanity checks on the processed packet.
588 */
589 int
590 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip,
591 int protoff)
592 {
593 char buf[INET6_ADDRSTRLEN];
594 struct ipsec_ctx_data ctx;
595 int prot, af, sproto;
596 struct ip6_hdr *ip6;
597 struct m_tag *mtag;
598 struct tdb_ident *tdbi;
599 struct secasindex *saidx;
600 int nxt, isr_prot;
601 u_int8_t nxt8;
602 int error, nest;
603 #ifdef notyet
604 char ip6buf[INET6_ADDRSTRLEN];
605 #endif
606
607 IPSEC_ASSERT(m != NULL, ("null mbuf"));
608 IPSEC_ASSERT(sav != NULL, ("null SA"));
609 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
610 saidx = &sav->sah->saidx;
611 af = saidx->dst.sa.sa_family;
612 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
613 sproto = saidx->proto;
614 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
615 sproto == IPPROTO_IPCOMP,
616 ("unexpected security protocol %u", sproto));
617
618 /* Sanity check */
619 if (m == NULL) {
620 DPRINTF(("%s: null mbuf", __func__));
621 IPSEC_ISTAT(sproto, badkcr);
622 error = EINVAL;
623 goto bad;
624 }
625
626 /* Fix IPv6 header */
627 if (m->m_len < sizeof(struct ip6_hdr) &&
628 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
629
630 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
631 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
632 sizeof(buf)), (u_long) ntohl(sav->spi)));
633
634 IPSEC_ISTAT(sproto, hdrops);
635 error = EACCES;
636 goto bad;
637 }
638
639 ip6 = mtod(m, struct ip6_hdr *);
640 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
641
642 IPSEC_INIT_CTX(&ctx, &m, sav, af, IPSEC_ENC_BEFORE);
643 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0)
644 goto bad;
645 /* Save protocol */
646 m_copydata(m, protoff, 1, &nxt8);
647 prot = nxt8;
648
649 /* IPv6-in-IP encapsulation */
650 if (prot == IPPROTO_IPV6 &&
651 saidx->mode != IPSEC_MODE_TRANSPORT) {
652 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
653 IPSEC_ISTAT(sproto, hdrops);
654 error = EINVAL;
655 goto bad;
656 }
657 /* ip6n will now contain the inner IPv6 header. */
658 m_striphdr(m, 0, skip);
659 skip = 0;
660 #ifdef notyet
661 /*
662 * Check that the inner source address is the same as
663 * the proxy address, if available.
664 */
665 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
666 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
667 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
668 &saidx->proxy.sin6.sin6_addr)) ||
669 (saidx->proxy.sa.sa_family != AF_INET6 &&
670 saidx->proxy.sa.sa_family != 0)) {
671
672 DPRINTF(("%s: inner source address %s doesn't "
673 "correspond to expected proxy source %s, "
674 "SA %s/%08lx\n", __func__,
675 ip6_sprintf(ip6buf, &ip6n.ip6_src),
676 ipsec_address(&saidx->proxy),
677 ipsec_address(&saidx->dst),
678 (u_long) ntohl(sav->spi)));
679
680 IPSEC_ISTAT(sproto, pdrops);
681 error = EACCES;
682 goto bad;
683 }
684 #endif /* notyet */
685 }
686 #ifdef INET
687 /* IP-in-IP encapsulation */
688 else if (prot == IPPROTO_IPIP &&
689 saidx->mode != IPSEC_MODE_TRANSPORT) {
690 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
691 IPSEC_ISTAT(sproto, hdrops);
692 error = EINVAL;
693 goto bad;
694 }
695 /* ipn will now contain the inner IPv4 header */
696 m_striphdr(m, 0, skip);
697 skip = 0;
698 #ifdef notyet
699 /*
700 * Check that the inner source address is the same as
701 * the proxy address, if available.
702 */
703 if ((saidx->proxy.sa.sa_family == AF_INET &&
704 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
705 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
706 (saidx->proxy.sa.sa_family != AF_INET &&
707 saidx->proxy.sa.sa_family != 0)) {
708
709 DPRINTF(("%s: inner source address %s doesn't "
710 "correspond to expected proxy source %s, "
711 "SA %s/%08lx\n", __func__,
712 inet_ntoa4(ipn.ip_src),
713 ipsec_address(&saidx->proxy),
714 ipsec_address(&saidx->dst),
715 (u_long) ntohl(sav->spi)));
716
717 IPSEC_ISTAT(sproto, pdrops);
718 error = EACCES;
719 goto bad;
720 }
721 #endif /* notyet */
722 }
723 #endif /* INET */
724 else {
725 prot = IPPROTO_IPV6; /* for correct BPF processing */
726 }
727
728 /*
729 * Record what we've done to the packet (under what SA it was
730 * processed).
731 */
732 if (sproto != IPPROTO_IPCOMP) {
733 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
734 sizeof(struct tdb_ident), M_NOWAIT);
735 if (mtag == NULL) {
736 DPRINTF(("%s: failed to get tag\n", __func__));
737 IPSEC_ISTAT(sproto, hdrops);
738 error = ENOMEM;
739 goto bad;
740 }
741
742 tdbi = (struct tdb_ident *)(mtag + 1);
743 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
744 tdbi->proto = sproto;
745 tdbi->spi = sav->spi;
746 /* Cache those two for enc(4) in xform_ipip. */
747 tdbi->alg_auth = sav->alg_auth;
748 tdbi->alg_enc = sav->alg_enc;
749
750 m_tag_prepend(m, mtag);
751 }
752
753 key_sa_recordxfer(sav, m);
754
755
756 #ifdef INET
757 if (prot == IPPROTO_IPIP)
758 af = AF_INET;
759 else
760 #endif
761 af = AF_INET6;
762 IPSEC_INIT_CTX(&ctx, &m, sav, af, IPSEC_ENC_AFTER);
763 if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_IN)) != 0)
764 goto bad;
765 if (skip == 0) {
766 /*
767 * We stripped outer IPv6 header.
768 * Now we should requeue decrypted packet via netisr.
769 */
770 switch (prot) {
771 #ifdef INET
772 case IPPROTO_IPIP:
773 isr_prot = NETISR_IP;
774 break;
775 #endif
776 case IPPROTO_IPV6:
777 isr_prot = NETISR_IPV6;
778 break;
779 default:
780 DPRINTF(("%s: cannot handle inner ip proto %d\n",
781 __func__, prot));
782 IPSEC_ISTAT(sproto, nopf);
783 error = EPFNOSUPPORT;
784 goto bad;
785 }
786 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m);
787 if (error) {
788 IPSEC_ISTAT(sproto, qfull);
789 DPRINTF(("%s: queue full; proto %u packet dropped\n",
790 __func__, sproto));
791 }
792 return (error);
793 }
794 /*
795 * See the end of ip6_input for this logic.
796 * IPPROTO_IPV[46] case will be processed just like other ones
797 */
798 nest = 0;
799 nxt = nxt8;
800 while (nxt != IPPROTO_DONE) {
801 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
802 IP6STAT_INC(ip6s_toomanyhdr);
803 error = EINVAL;
804 goto bad;
805 }
806
807 /*
808 * Protection against faulty packet - there should be
809 * more sanity checks in header chain processing.
810 */
811 if (m->m_pkthdr.len < skip) {
812 IP6STAT_INC(ip6s_tooshort);
813 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
814 error = EINVAL;
815 goto bad;
816 }
817 /*
818 * Enforce IPsec policy checking if we are seeing last header.
819 * note that we do not visit this with protocols with pcb layer
820 * code - like udp/tcp/raw ip.
821 */
822 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
823 ipsec6_in_reject(m, NULL)) {
824 error = EINVAL;
825 goto bad;
826 }
827 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
828 }
829 return 0;
830 bad:
831 if (m)
832 m_freem(m);
833 return error;
834 }
835
836 void
837 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
838 {
839 struct ip6ctlparam *ip6cp = NULL;
840 struct mbuf *m = NULL;
841 struct ip6_hdr *ip6;
842 int off;
843
844 if (sa->sa_family != AF_INET6 ||
845 sa->sa_len != sizeof(struct sockaddr_in6))
846 return;
847 if ((unsigned)cmd >= PRC_NCMDS)
848 return;
849
850 /* if the parameter is from icmp6, decode it. */
851 if (d != NULL) {
852 ip6cp = (struct ip6ctlparam *)d;
853 m = ip6cp->ip6c_m;
854 ip6 = ip6cp->ip6c_ip6;
855 off = ip6cp->ip6c_off;
856 } else {
857 m = NULL;
858 ip6 = NULL;
859 off = 0; /* calm gcc */
860 }
861
862 if (ip6 != NULL) {
863
864 struct ip6ctlparam ip6cp1;
865
866 /*
867 * Notify the error to all possible sockets via pfctlinput2.
868 * Since the upper layer information (such as protocol type,
869 * source and destination ports) is embedded in the encrypted
870 * data and might have been cut, we can't directly call
871 * an upper layer ctlinput function. However, the pcbnotify
872 * function will consider source and destination addresses
873 * as well as the flow info value, and may be able to find
874 * some PCB that should be notified.
875 * Although pfctlinput2 will call esp6_ctlinput(), there is
876 * no possibility of an infinite loop of function calls,
877 * because we don't pass the inner IPv6 header.
878 */
879 bzero(&ip6cp1, sizeof(ip6cp1));
880 ip6cp1.ip6c_src = ip6cp->ip6c_src;
881 pfctlinput2(cmd, sa, (void *)&ip6cp1);
882
883 /*
884 * Then go to special cases that need ESP header information.
885 * XXX: We assume that when ip6 is non NULL,
886 * M and OFF are valid.
887 */
888
889 if (cmd == PRC_MSGSIZE) {
890 struct secasvar *sav;
891 u_int32_t spi;
892 int valid;
893
894 /* check header length before using m_copydata */
895 if (m->m_pkthdr.len < off + sizeof (struct esp))
896 return;
897 m_copydata(m, off + offsetof(struct esp, esp_spi),
898 sizeof(u_int32_t), (caddr_t) &spi);
899 /*
900 * Check to see if we have a valid SA corresponding to
901 * the address in the ICMP message payload.
902 */
903 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
904 IPPROTO_ESP, spi);
905 valid = (sav != NULL);
906 if (sav)
907 KEY_FREESAV(&sav);
908
909 /* XXX Further validation? */
910
911 /*
912 * Depending on whether the SA is "valid" and
913 * routing table size (mtudisc_{hi,lo}wat), we will:
914 * - recalcurate the new MTU and create the
915 * corresponding routing entry, or
916 * - ignore the MTU change notification.
917 */
918 icmp6_mtudisc_update(ip6cp, valid);
919 }
920 } else {
921 /* we normally notify any pcb here */
922 }
923 }
924 #endif /* INET6 */
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