1 /* $FreeBSD$ */
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 #include "opt_enc.h"
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/malloc.h>
51 #include <sys/mbuf.h>
52 #include <sys/domain.h>
53 #include <sys/protosw.h>
54 #include <sys/socket.h>
55 #include <sys/errno.h>
56 #include <sys/syslog.h>
57
58 #include <net/if.h>
59 #include <net/pfil.h>
60 #include <net/netisr.h>
61 #include <net/vnet.h>
62
63 #include <netinet/in.h>
64 #include <netinet/in_systm.h>
65 #include <netinet/ip.h>
66 #include <netinet/ip_var.h>
67 #include <netinet/in_var.h>
68
69 #include <netinet/ip6.h>
70 #ifdef INET6
71 #include <netinet6/ip6_var.h>
72 #endif
73 #include <netinet/in_pcb.h>
74 #ifdef INET6
75 #include <netinet/icmp6.h>
76 #endif
77
78 #include <netipsec/ipsec.h>
79 #ifdef INET6
80 #include <netipsec/ipsec6.h>
81 #endif
82 #include <netipsec/ah_var.h>
83 #include <netipsec/esp.h>
84 #include <netipsec/esp_var.h>
85 #include <netipsec/ipcomp_var.h>
86
87 #include <netipsec/key.h>
88 #include <netipsec/keydb.h>
89
90 #include <netipsec/xform.h>
91 #include <netinet6/ip6protosw.h>
92
93 #include <machine/in_cksum.h>
94 #include <machine/stdarg.h>
95
96 #ifdef DEV_ENC
97 #include <net/if_enc.h>
98 #endif
99
100
101 #define IPSEC_ISTAT(proto, name) do { \
102 if ((proto) == IPPROTO_ESP) \
103 ESPSTAT_INC(esps_##name); \
104 else if ((proto) == IPPROTO_AH) \
105 AHSTAT_INC(ahs_##name); \
106 else \
107 IPCOMPSTAT_INC(ipcomps_##name); \
108 } while (0)
109
110 #ifdef INET
111 static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
112 #endif
113
114 /*
115 * ipsec_common_input gets called when an IPsec-protected packet
116 * is received by IPv4 or IPv6. Its job is to find the right SA
117 * and call the appropriate transform. The transform callback
118 * takes care of further processing (like ingress filtering).
119 */
120 static int
ipsec_common_input(struct mbuf * m,int skip,int protoff,int af,int sproto)121 ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
122 {
123 union sockaddr_union dst_address;
124 struct secasvar *sav;
125 u_int32_t spi;
126 int error;
127 #ifdef INET
128 #ifdef IPSEC_NAT_T
129 struct m_tag *tag;
130 #endif
131 #endif
132
133 IPSEC_ISTAT(sproto, input);
134
135 IPSEC_ASSERT(m != NULL, ("null packet"));
136
137 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
138 sproto == IPPROTO_IPCOMP,
139 ("unexpected security protocol %u", sproto));
140
141 if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
142 (sproto == IPPROTO_AH && !V_ah_enable) ||
143 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
144 m_freem(m);
145 IPSEC_ISTAT(sproto, pdrops);
146 return EOPNOTSUPP;
147 }
148
149 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
150 m_freem(m);
151 IPSEC_ISTAT(sproto, hdrops);
152 DPRINTF(("%s: packet too small\n", __func__));
153 return EINVAL;
154 }
155
156 /* Retrieve the SPI from the relevant IPsec header */
157 if (sproto == IPPROTO_ESP)
158 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
159 else if (sproto == IPPROTO_AH)
160 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
161 (caddr_t) &spi);
162 else if (sproto == IPPROTO_IPCOMP) {
163 u_int16_t cpi;
164 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
165 (caddr_t) &cpi);
166 spi = ntohl(htons(cpi));
167 }
168
169 /*
170 * Find the SA and (indirectly) call the appropriate
171 * kernel crypto routine. The resulting mbuf chain is a valid
172 * IP packet ready to go through input processing.
173 */
174 bzero(&dst_address, sizeof (dst_address));
175 dst_address.sa.sa_family = af;
176 switch (af) {
177 #ifdef INET
178 case AF_INET:
179 dst_address.sin.sin_len = sizeof(struct sockaddr_in);
180 m_copydata(m, offsetof(struct ip, ip_dst),
181 sizeof(struct in_addr),
182 (caddr_t) &dst_address.sin.sin_addr);
183 #ifdef IPSEC_NAT_T
184 /* Find the source port for NAT-T; see udp*_espdecap. */
185 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL);
186 if (tag != NULL)
187 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1];
188 #endif /* IPSEC_NAT_T */
189 break;
190 #endif /* INET */
191 #ifdef INET6
192 case AF_INET6:
193 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
194 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
195 sizeof(struct in6_addr),
196 (caddr_t) &dst_address.sin6.sin6_addr);
197 break;
198 #endif /* INET6 */
199 default:
200 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
201 m_freem(m);
202 IPSEC_ISTAT(sproto, nopf);
203 return EPFNOSUPPORT;
204 }
205
206 /* NB: only pass dst since key_allocsa follows RFC2401 */
207 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
208 if (sav == NULL) {
209 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
210 __func__, ipsec_address(&dst_address),
211 (u_long) ntohl(spi), sproto));
212 IPSEC_ISTAT(sproto, notdb);
213 m_freem(m);
214 return ENOENT;
215 }
216
217 if (sav->tdb_xform == NULL) {
218 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
219 __func__, ipsec_address(&dst_address),
220 (u_long) ntohl(spi), sproto));
221 IPSEC_ISTAT(sproto, noxform);
222 KEY_FREESAV(&sav);
223 m_freem(m);
224 return ENXIO;
225 }
226
227 /*
228 * Call appropriate transform and return -- callback takes care of
229 * everything else.
230 */
231 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
232 KEY_FREESAV(&sav);
233 return error;
234 }
235
236 #ifdef INET
237 /*
238 * Common input handler for IPv4 AH, ESP, and IPCOMP.
239 */
240 int
ipsec4_common_input(struct mbuf * m,...)241 ipsec4_common_input(struct mbuf *m, ...)
242 {
243 va_list ap;
244 int off, nxt;
245
246 va_start(ap, m);
247 off = va_arg(ap, int);
248 nxt = va_arg(ap, int);
249 va_end(ap);
250
251 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
252 AF_INET, nxt);
253 }
254
255 void
ah4_input(struct mbuf * m,int off)256 ah4_input(struct mbuf *m, int off)
257 {
258 ipsec4_common_input(m, off, IPPROTO_AH);
259 }
260 void
ah4_ctlinput(int cmd,struct sockaddr * sa,void * v)261 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
262 {
263 if (sa->sa_family == AF_INET &&
264 sa->sa_len == sizeof(struct sockaddr_in))
265 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
266 }
267
268 void
esp4_input(struct mbuf * m,int off)269 esp4_input(struct mbuf *m, int off)
270 {
271 ipsec4_common_input(m, off, IPPROTO_ESP);
272 }
273 void
esp4_ctlinput(int cmd,struct sockaddr * sa,void * v)274 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
275 {
276 if (sa->sa_family == AF_INET &&
277 sa->sa_len == sizeof(struct sockaddr_in))
278 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
279 }
280
281 void
ipcomp4_input(struct mbuf * m,int off)282 ipcomp4_input(struct mbuf *m, int off)
283 {
284 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
285 }
286
287 /*
288 * IPsec input callback for INET protocols.
289 * This routine is called as the transform callback.
290 * Takes care of filtering and other sanity checks on
291 * the processed packet.
292 */
293 int
ipsec4_common_input_cb(struct mbuf * m,struct secasvar * sav,int skip,int protoff,struct m_tag * mt)294 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
295 int skip, int protoff, struct m_tag *mt)
296 {
297 int prot, af, sproto, isr_prot;
298 struct ip *ip;
299 struct m_tag *mtag;
300 struct tdb_ident *tdbi;
301 struct secasindex *saidx;
302 int error;
303 #ifdef INET6
304 #ifdef notyet
305 char ip6buf[INET6_ADDRSTRLEN];
306 #endif
307 #endif
308
309 IPSEC_ASSERT(m != NULL, ("null mbuf"));
310 IPSEC_ASSERT(sav != NULL, ("null SA"));
311 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
312 saidx = &sav->sah->saidx;
313 af = saidx->dst.sa.sa_family;
314 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
315 sproto = saidx->proto;
316 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
317 sproto == IPPROTO_IPCOMP,
318 ("unexpected security protocol %u", sproto));
319
320 /* Sanity check */
321 if (m == NULL) {
322 DPRINTF(("%s: null mbuf", __func__));
323 IPSEC_ISTAT(sproto, badkcr);
324 KEY_FREESAV(&sav);
325 return EINVAL;
326 }
327
328 if (skip != 0) {
329 /*
330 * Fix IPv4 header
331 * XXXGL: do we need this entire block?
332 */
333 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
334 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
335 __func__, ipsec_address(&sav->sah->saidx.dst),
336 (u_long) ntohl(sav->spi)));
337 IPSEC_ISTAT(sproto, hdrops);
338 error = ENOBUFS;
339 goto bad;
340 }
341
342 ip = mtod(m, struct ip *);
343 ip->ip_len = htons(m->m_pkthdr.len);
344 ip->ip_sum = 0;
345 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
346 } else {
347 ip = mtod(m, struct ip *);
348 }
349 prot = ip->ip_p;
350
351 #ifdef DEV_ENC
352 encif->if_ipackets++;
353 encif->if_ibytes += m->m_pkthdr.len;
354
355 /* Pass the mbuf to enc0 for bpf and pfil. */
356 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE);
357 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
358 return (error);
359 #endif /* DEV_ENC */
360
361 /* IP-in-IP encapsulation */
362 if (prot == IPPROTO_IPIP &&
363 saidx->mode != IPSEC_MODE_TRANSPORT) {
364
365 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
366 IPSEC_ISTAT(sproto, hdrops);
367 error = EINVAL;
368 goto bad;
369 }
370 /* enc0: strip outer IPv4 header */
371 m_striphdr(m, 0, ip->ip_hl << 2);
372
373 #ifdef notyet
374 /* XXX PROXY address isn't recorded in SAH */
375 /*
376 * Check that the inner source address is the same as
377 * the proxy address, if available.
378 */
379 if ((saidx->proxy.sa.sa_family == AF_INET &&
380 saidx->proxy.sin.sin_addr.s_addr !=
381 INADDR_ANY &&
382 ipn.ip_src.s_addr !=
383 saidx->proxy.sin.sin_addr.s_addr) ||
384 (saidx->proxy.sa.sa_family != AF_INET &&
385 saidx->proxy.sa.sa_family != 0)) {
386
387 DPRINTF(("%s: inner source address %s doesn't "
388 "correspond to expected proxy source %s, "
389 "SA %s/%08lx\n", __func__,
390 inet_ntoa4(ipn.ip_src),
391 ipsp_address(saidx->proxy),
392 ipsp_address(saidx->dst),
393 (u_long) ntohl(sav->spi)));
394
395 IPSEC_ISTAT(sproto, pdrops);
396 error = EACCES;
397 goto bad;
398 }
399 #endif /* notyet */
400 }
401 #ifdef INET6
402 /* IPv6-in-IP encapsulation. */
403 else if (prot == IPPROTO_IPV6 &&
404 saidx->mode != IPSEC_MODE_TRANSPORT) {
405
406 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
407 IPSEC_ISTAT(sproto, hdrops);
408 error = EINVAL;
409 goto bad;
410 }
411 /* enc0: strip IPv4 header, keep IPv6 header only */
412 m_striphdr(m, 0, ip->ip_hl << 2);
413 #ifdef notyet
414 /*
415 * Check that the inner source address is the same as
416 * the proxy address, if available.
417 */
418 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
419 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
420 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
421 &saidx->proxy.sin6.sin6_addr)) ||
422 (saidx->proxy.sa.sa_family != AF_INET6 &&
423 saidx->proxy.sa.sa_family != 0)) {
424
425 DPRINTF(("%s: inner source address %s doesn't "
426 "correspond to expected proxy source %s, "
427 "SA %s/%08lx\n", __func__,
428 ip6_sprintf(ip6buf, &ip6n.ip6_src),
429 ipsec_address(&saidx->proxy),
430 ipsec_address(&saidx->dst),
431 (u_long) ntohl(sav->spi)));
432
433 IPSEC_ISTAT(sproto, pdrops);
434 error = EACCES;
435 goto bad;
436 }
437 #endif /* notyet */
438 }
439 #endif /* INET6 */
440 else if (prot != IPPROTO_IPV6 && saidx->mode == IPSEC_MODE_ANY) {
441 /*
442 * When mode is wildcard, inner protocol is IPv6 and
443 * we have no INET6 support - drop this packet a bit later.
444 * In other cases we assume transport mode and outer
445 * header was already stripped in xform_xxx_cb.
446 */
447 prot = IPPROTO_IPIP;
448 }
449
450 /*
451 * Record what we've done to the packet (under what SA it was
452 * processed). If we've been passed an mtag, it means the packet
453 * was already processed by an ethernet/crypto combo card and
454 * thus has a tag attached with all the right information, but
455 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
456 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
457 */
458 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
459 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
460 sizeof(struct tdb_ident), M_NOWAIT);
461 if (mtag == NULL) {
462 DPRINTF(("%s: failed to get tag\n", __func__));
463 IPSEC_ISTAT(sproto, hdrops);
464 error = ENOMEM;
465 goto bad;
466 }
467
468 tdbi = (struct tdb_ident *)(mtag + 1);
469 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
470 tdbi->proto = sproto;
471 tdbi->spi = sav->spi;
472 /* Cache those two for enc(4) in xform_ipip. */
473 tdbi->alg_auth = sav->alg_auth;
474 tdbi->alg_enc = sav->alg_enc;
475
476 m_tag_prepend(m, mtag);
477 } else if (mt != NULL) {
478 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
479 /* XXX do we need to mark m_flags??? */
480 }
481
482 key_sa_recordxfer(sav, m); /* record data transfer */
483
484 /*
485 * In transport mode requeue decrypted mbuf back to IPv4 protocol
486 * handler. This is necessary to correctly expose rcvif.
487 */
488 if (saidx->mode == IPSEC_MODE_TRANSPORT)
489 prot = IPPROTO_IPIP;
490 #ifdef DEV_ENC
491 /*
492 * Pass the mbuf to enc0 for bpf and pfil.
493 */
494 if (prot == IPPROTO_IPIP)
495 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER);
496 #ifdef INET6
497 if (prot == IPPROTO_IPV6)
498 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER);
499 #endif
500
501 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0)
502 return (error);
503 #endif /* DEV_ENC */
504
505 /*
506 * Re-dispatch via software interrupt.
507 */
508
509 switch (prot) {
510 case IPPROTO_IPIP:
511 isr_prot = NETISR_IP;
512 break;
513 #ifdef INET6
514 case IPPROTO_IPV6:
515 isr_prot = NETISR_IPV6;
516 break;
517 #endif
518 default:
519 DPRINTF(("%s: cannot handle inner ip proto %d\n",
520 __func__, prot));
521 IPSEC_ISTAT(sproto, nopf);
522 error = EPFNOSUPPORT;
523 goto bad;
524 }
525
526 error = netisr_queue_src(isr_prot, (uintptr_t)sav->spi, m);
527 if (error) {
528 IPSEC_ISTAT(sproto, qfull);
529 DPRINTF(("%s: queue full; proto %u packet dropped\n",
530 __func__, sproto));
531 return error;
532 }
533 return 0;
534 bad:
535 m_freem(m);
536 return error;
537 }
538
539 void
ipsec4_common_ctlinput(int cmd,struct sockaddr * sa,void * v,int proto)540 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
541 {
542 /* XXX nothing just yet */
543 }
544 #endif /* INET */
545
546 #ifdef INET6
547 /* IPv6 AH wrapper. */
548 int
ipsec6_common_input(struct mbuf ** mp,int * offp,int proto)549 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
550 {
551 int l = 0;
552 int protoff;
553 struct ip6_ext ip6e;
554
555 if (*offp < sizeof(struct ip6_hdr)) {
556 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
557 return IPPROTO_DONE;
558 } else if (*offp == sizeof(struct ip6_hdr)) {
559 protoff = offsetof(struct ip6_hdr, ip6_nxt);
560 } else {
561 /* Chase down the header chain... */
562 protoff = sizeof(struct ip6_hdr);
563
564 do {
565 protoff += l;
566 m_copydata(*mp, protoff, sizeof(ip6e),
567 (caddr_t) &ip6e);
568
569 if (ip6e.ip6e_nxt == IPPROTO_AH)
570 l = (ip6e.ip6e_len + 2) << 2;
571 else
572 l = (ip6e.ip6e_len + 1) << 3;
573 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
574 } while (protoff + l < *offp);
575
576 /* Malformed packet check */
577 if (protoff + l != *offp) {
578 DPRINTF(("%s: bad packet header chain, protoff %u, "
579 "l %u, off %u\n", __func__, protoff, l, *offp));
580 IPSEC_ISTAT(proto, hdrops);
581 m_freem(*mp);
582 *mp = NULL;
583 return IPPROTO_DONE;
584 }
585 protoff += offsetof(struct ip6_ext, ip6e_nxt);
586 }
587 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
588 return IPPROTO_DONE;
589 }
590
591 /*
592 * IPsec input callback, called by the transform callback. Takes care of
593 * filtering and other sanity checks on the processed packet.
594 */
595 int
ipsec6_common_input_cb(struct mbuf * m,struct secasvar * sav,int skip,int protoff,struct m_tag * mt)596 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
597 struct m_tag *mt)
598 {
599 int prot, af, sproto;
600 struct ip6_hdr *ip6;
601 struct m_tag *mtag;
602 struct tdb_ident *tdbi;
603 struct secasindex *saidx;
604 int nxt;
605 u_int8_t nxt8;
606 int error, nest;
607 #ifdef notyet
608 char ip6buf[INET6_ADDRSTRLEN];
609 #endif
610
611 IPSEC_ASSERT(m != NULL, ("null mbuf"));
612 IPSEC_ASSERT(sav != NULL, ("null SA"));
613 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
614 saidx = &sav->sah->saidx;
615 af = saidx->dst.sa.sa_family;
616 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
617 sproto = saidx->proto;
618 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
619 sproto == IPPROTO_IPCOMP,
620 ("unexpected security protocol %u", sproto));
621
622 /* Sanity check */
623 if (m == NULL) {
624 DPRINTF(("%s: null mbuf", __func__));
625 IPSEC_ISTAT(sproto, badkcr);
626 error = EINVAL;
627 goto bad;
628 }
629
630 /* Fix IPv6 header */
631 if (m->m_len < sizeof(struct ip6_hdr) &&
632 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
633
634 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
635 __func__, ipsec_address(&sav->sah->saidx.dst),
636 (u_long) ntohl(sav->spi)));
637
638 IPSEC_ISTAT(sproto, hdrops);
639 error = EACCES;
640 goto bad;
641 }
642
643 ip6 = mtod(m, struct ip6_hdr *);
644 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
645
646 /* Save protocol */
647 m_copydata(m, protoff, 1, &nxt8);
648 prot = nxt8;
649
650 #ifdef DEV_ENC
651 encif->if_ipackets++;
652 encif->if_ibytes += m->m_pkthdr.len;
653
654 /* Pass the mbuf to enc0 for bpf and pfil. */
655 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE);
656 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
657 return (error);
658 #endif /* DEV_ENC */
659
660 /* IPv6-in-IP encapsulation */
661 if (prot == IPPROTO_IPV6 &&
662 saidx->mode != IPSEC_MODE_TRANSPORT) {
663 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
664 IPSEC_ISTAT(sproto, hdrops);
665 error = EINVAL;
666 goto bad;
667 }
668 /* ip6n will now contain the inner IPv6 header. */
669 m_striphdr(m, 0, skip);
670 skip = 0;
671 #ifdef notyet
672 /*
673 * Check that the inner source address is the same as
674 * the proxy address, if available.
675 */
676 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
677 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
678 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
679 &saidx->proxy.sin6.sin6_addr)) ||
680 (saidx->proxy.sa.sa_family != AF_INET6 &&
681 saidx->proxy.sa.sa_family != 0)) {
682
683 DPRINTF(("%s: inner source address %s doesn't "
684 "correspond to expected proxy source %s, "
685 "SA %s/%08lx\n", __func__,
686 ip6_sprintf(ip6buf, &ip6n.ip6_src),
687 ipsec_address(&saidx->proxy),
688 ipsec_address(&saidx->dst),
689 (u_long) ntohl(sav->spi)));
690
691 IPSEC_ISTAT(sproto, pdrops);
692 error = EACCES;
693 goto bad;
694 }
695 #endif /* notyet */
696 }
697 #ifdef INET
698 /* IP-in-IP encapsulation */
699 else if (prot == IPPROTO_IPIP &&
700 saidx->mode != IPSEC_MODE_TRANSPORT) {
701 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
702 IPSEC_ISTAT(sproto, hdrops);
703 error = EINVAL;
704 goto bad;
705 }
706 /* ipn will now contain the inner IPv4 header */
707 m_striphdr(m, 0, skip);
708 skip = 0;
709 #ifdef notyet
710 /*
711 * Check that the inner source address is the same as
712 * the proxy address, if available.
713 */
714 if ((saidx->proxy.sa.sa_family == AF_INET &&
715 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
716 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
717 (saidx->proxy.sa.sa_family != AF_INET &&
718 saidx->proxy.sa.sa_family != 0)) {
719
720 DPRINTF(("%s: inner source address %s doesn't "
721 "correspond to expected proxy source %s, "
722 "SA %s/%08lx\n", __func__,
723 inet_ntoa4(ipn.ip_src),
724 ipsec_address(&saidx->proxy),
725 ipsec_address(&saidx->dst),
726 (u_long) ntohl(sav->spi)));
727
728 IPSEC_ISTAT(sproto, pdrops);
729 error = EACCES;
730 goto bad;
731 }
732 #endif /* notyet */
733 }
734 #endif /* INET */
735 else {
736 prot = IPPROTO_IPV6; /* for correct BPF processing */
737 }
738
739 /*
740 * Record what we've done to the packet (under what SA it was
741 * processed). If we've been passed an mtag, it means the packet
742 * was already processed by an ethernet/crypto combo card and
743 * thus has a tag attached with all the right information, but
744 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
745 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
746 */
747 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
748 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
749 sizeof(struct tdb_ident), M_NOWAIT);
750 if (mtag == NULL) {
751 DPRINTF(("%s: failed to get tag\n", __func__));
752 IPSEC_ISTAT(sproto, hdrops);
753 error = ENOMEM;
754 goto bad;
755 }
756
757 tdbi = (struct tdb_ident *)(mtag + 1);
758 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
759 tdbi->proto = sproto;
760 tdbi->spi = sav->spi;
761 /* Cache those two for enc(4) in xform_ipip. */
762 tdbi->alg_auth = sav->alg_auth;
763 tdbi->alg_enc = sav->alg_enc;
764
765 m_tag_prepend(m, mtag);
766 } else {
767 if (mt != NULL)
768 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
769 /* XXX do we need to mark m_flags??? */
770 }
771
772 key_sa_recordxfer(sav, m);
773
774 #ifdef DEV_ENC
775 /*
776 * Pass the mbuf to enc0 for bpf and pfil.
777 */
778 #ifdef INET
779 if (prot == IPPROTO_IPIP)
780 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_AFTER);
781 #endif
782 if (prot == IPPROTO_IPV6)
783 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_AFTER);
784
785 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_AFTER)) != 0)
786 return (error);
787 #endif /* DEV_ENC */
788 /*
789 * See the end of ip6_input for this logic.
790 * IPPROTO_IPV[46] case will be processed just like other ones
791 */
792 nest = 0;
793 nxt = nxt8;
794 while (nxt != IPPROTO_DONE) {
795 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
796 IP6STAT_INC(ip6s_toomanyhdr);
797 error = EINVAL;
798 goto bad;
799 }
800
801 /*
802 * Protection against faulty packet - there should be
803 * more sanity checks in header chain processing.
804 */
805 if (m->m_pkthdr.len < skip) {
806 IP6STAT_INC(ip6s_tooshort);
807 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
808 error = EINVAL;
809 goto bad;
810 }
811 /*
812 * Enforce IPsec policy checking if we are seeing last header.
813 * note that we do not visit this with protocols with pcb layer
814 * code - like udp/tcp/raw ip.
815 */
816 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
817 ipsec6_in_reject(m, NULL)) {
818 error = EINVAL;
819 goto bad;
820 }
821 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
822 }
823 return 0;
824 bad:
825 if (m)
826 m_freem(m);
827 return error;
828 }
829
830 void
esp6_ctlinput(int cmd,struct sockaddr * sa,void * d)831 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
832 {
833 struct ip6ctlparam *ip6cp = NULL;
834 struct mbuf *m = NULL;
835 struct ip6_hdr *ip6;
836 int off;
837
838 if (sa->sa_family != AF_INET6 ||
839 sa->sa_len != sizeof(struct sockaddr_in6))
840 return;
841 if ((unsigned)cmd >= PRC_NCMDS)
842 return;
843
844 /* if the parameter is from icmp6, decode it. */
845 if (d != NULL) {
846 ip6cp = (struct ip6ctlparam *)d;
847 m = ip6cp->ip6c_m;
848 ip6 = ip6cp->ip6c_ip6;
849 off = ip6cp->ip6c_off;
850 } else {
851 m = NULL;
852 ip6 = NULL;
853 off = 0; /* calm gcc */
854 }
855
856 if (ip6 != NULL) {
857
858 struct ip6ctlparam ip6cp1;
859
860 /*
861 * Notify the error to all possible sockets via pfctlinput2.
862 * Since the upper layer information (such as protocol type,
863 * source and destination ports) is embedded in the encrypted
864 * data and might have been cut, we can't directly call
865 * an upper layer ctlinput function. However, the pcbnotify
866 * function will consider source and destination addresses
867 * as well as the flow info value, and may be able to find
868 * some PCB that should be notified.
869 * Although pfctlinput2 will call esp6_ctlinput(), there is
870 * no possibility of an infinite loop of function calls,
871 * because we don't pass the inner IPv6 header.
872 */
873 bzero(&ip6cp1, sizeof(ip6cp1));
874 ip6cp1.ip6c_src = ip6cp->ip6c_src;
875 pfctlinput2(cmd, sa, (void *)&ip6cp1);
876
877 /*
878 * Then go to special cases that need ESP header information.
879 * XXX: We assume that when ip6 is non NULL,
880 * M and OFF are valid.
881 */
882
883 if (cmd == PRC_MSGSIZE) {
884 struct secasvar *sav;
885 u_int32_t spi;
886 int valid;
887
888 /* check header length before using m_copydata */
889 if (m->m_pkthdr.len < off + sizeof (struct esp))
890 return;
891 m_copydata(m, off + offsetof(struct esp, esp_spi),
892 sizeof(u_int32_t), (caddr_t) &spi);
893 /*
894 * Check to see if we have a valid SA corresponding to
895 * the address in the ICMP message payload.
896 */
897 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
898 IPPROTO_ESP, spi);
899 valid = (sav != NULL);
900 if (sav)
901 KEY_FREESAV(&sav);
902
903 /* XXX Further validation? */
904
905 /*
906 * Depending on whether the SA is "valid" and
907 * routing table size (mtudisc_{hi,lo}wat), we will:
908 * - recalcurate the new MTU and create the
909 * corresponding routing entry, or
910 * - ignore the MTU change notification.
911 */
912 icmp6_mtudisc_update(ip6cp, valid);
913 }
914 } else {
915 /* we normally notify any pcb here */
916 }
917 }
918 #endif /* INET6 */
919