1/* $FreeBSD: head/sys/netipsec/ipsec_input.c 249294 2013-04-09 07:11:22Z 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#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/route.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#ifdef DEV_ENC
98#include <net/if_enc.h>
99#endif
100
101
102#define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \
103 (p) == IPPROTO_AH ? (y)++ : (z)++)
104
105#ifdef INET
106static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
107#endif
108
109/*
110 * ipsec_common_input gets called when an IPsec-protected packet
111 * is received by IPv4 or IPv6. Its job is to find the right SA
112 * and call the appropriate transform. The transform callback
113 * takes care of further processing (like ingress filtering).
114 */
115static int
116ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
117{
118 union sockaddr_union dst_address;
119 struct secasvar *sav;
120 u_int32_t spi;
121 int error;
122#ifdef INET
123#ifdef IPSEC_NAT_T
124 struct m_tag *tag;
125#endif
126#endif
127
128 IPSEC_ISTAT(sproto, V_espstat.esps_input, V_ahstat.ahs_input,
129 V_ipcompstat.ipcomps_input);
130
131 IPSEC_ASSERT(m != NULL, ("null packet"));
132
133 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
134 sproto == IPPROTO_IPCOMP,
135 ("unexpected security protocol %u", sproto));
136
137 if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
138 (sproto == IPPROTO_AH && !V_ah_enable) ||
139 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
140 m_freem(m);
141 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops, V_ahstat.ahs_pdrops,
142 V_ipcompstat.ipcomps_pdrops);
143 return EOPNOTSUPP;
144 }
145
146 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
147 m_freem(m);
148 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
149 V_ipcompstat.ipcomps_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 break;
196#endif /* INET6 */
197 default:
198 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
199 m_freem(m);
200 IPSEC_ISTAT(sproto, V_espstat.esps_nopf, V_ahstat.ahs_nopf,
201 V_ipcompstat.ipcomps_nopf);
202 return EPFNOSUPPORT;
203 }
204
205 /* NB: only pass dst since key_allocsa follows RFC2401 */
206 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
207 if (sav == NULL) {
208 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
209 __func__, ipsec_address(&dst_address),
210 (u_long) ntohl(spi), sproto));
211 IPSEC_ISTAT(sproto, V_espstat.esps_notdb, V_ahstat.ahs_notdb,
212 V_ipcompstat.ipcomps_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, V_espstat.esps_noxform, V_ahstat.ahs_noxform,
222 V_ipcompstat.ipcomps_noxform);
223 KEY_FREESAV(&sav);
224 m_freem(m);
225 return ENXIO;
226 }
227
228 /*
229 * Call appropriate transform and return -- callback takes care of
230 * everything else.
231 */
232 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
233 KEY_FREESAV(&sav);
234 return error;
235}
236
237#ifdef INET
238/*
239 * Common input handler for IPv4 AH, ESP, and IPCOMP.
240 */
241int
242ipsec4_common_input(struct mbuf *m, ...)
243{
244 va_list ap;
245 int off, nxt;
246
247 va_start(ap, m);
248 off = va_arg(ap, int);
249 nxt = va_arg(ap, int);
250 va_end(ap);
251
252 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
253 AF_INET, nxt);
254}
255
256void
257ah4_input(struct mbuf *m, int off)
258{
259 ipsec4_common_input(m, off, IPPROTO_AH);
260}
261void
262ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
263{
264 if (sa->sa_family == AF_INET &&
265 sa->sa_len == sizeof(struct sockaddr_in))
266 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
267}
268
269void
270esp4_input(struct mbuf *m, int off)
271{
272 ipsec4_common_input(m, off, IPPROTO_ESP);
273}
274void
275esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
276{
277 if (sa->sa_family == AF_INET &&
278 sa->sa_len == sizeof(struct sockaddr_in))
279 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
280}
281
282void
283ipcomp4_input(struct mbuf *m, int off)
284{
285 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
286}
287
288/*
289 * IPsec input callback for INET protocols.
290 * This routine is called as the transform callback.
291 * Takes care of filtering and other sanity checks on
292 * the processed packet.
293 */
294int
295ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
296 int skip, int protoff, struct m_tag *mt)
297{
298 int prot, af, sproto;
299 struct ip *ip;
300 struct m_tag *mtag;
301 struct tdb_ident *tdbi;
302 struct secasindex *saidx;
303 int error;
304#ifdef INET6
305#ifdef notyet
306 char ip6buf[INET6_ADDRSTRLEN];
307#endif
308#endif
309
310 IPSEC_ASSERT(m != NULL, ("null mbuf"));
311 IPSEC_ASSERT(sav != NULL, ("null SA"));
312 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
313 saidx = &sav->sah->saidx;
314 af = saidx->dst.sa.sa_family;
315 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
316 sproto = saidx->proto;
317 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
318 sproto == IPPROTO_IPCOMP,
319 ("unexpected security protocol %u", sproto));
320
321 /* Sanity check */
322 if (m == NULL) {
323 DPRINTF(("%s: null mbuf", __func__));
324 IPSEC_ISTAT(sproto, V_espstat.esps_badkcr, V_ahstat.ahs_badkcr,
325 V_ipcompstat.ipcomps_badkcr);
326 KEY_FREESAV(&sav);
327 return EINVAL;
328 }
329
330 if (skip != 0) {
331 /*
332 * Fix IPv4 header
333 * XXXGL: do we need this entire block?
334 */
335 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
336 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
337 __func__, ipsec_address(&sav->sah->saidx.dst),
338 (u_long) ntohl(sav->spi)));
339 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
340 V_ipcompstat.ipcomps_hdrops);
341 error = ENOBUFS;
342 goto bad;
343 }
344
345 ip = mtod(m, struct ip *);
346 ip->ip_len = htons(m->m_pkthdr.len);
347 ip->ip_sum = 0;
348 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
349 } else {
350 ip = mtod(m, struct ip *);
351 }
352 prot = ip->ip_p;
353
354#ifdef notyet
355 /* IP-in-IP encapsulation */
356 if (prot == IPPROTO_IPIP) {
357 struct ip ipn;
358
359 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
360 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
361 V_ahstat.ahs_hdrops,
362 V_ipcompstat.ipcomps_hdrops);
363 error = EINVAL;
364 goto bad;
365 }
366 /* ipn will now contain the inner IPv4 header */
367 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
368 (caddr_t) &ipn);
369
370 /* XXX PROXY address isn't recorded in SAH */
371 /*
372 * Check that the inner source address is the same as
373 * the proxy address, if available.
374 */
375 if ((saidx->proxy.sa.sa_family == AF_INET &&
376 saidx->proxy.sin.sin_addr.s_addr !=
377 INADDR_ANY &&
378 ipn.ip_src.s_addr !=
379 saidx->proxy.sin.sin_addr.s_addr) ||
380 (saidx->proxy.sa.sa_family != AF_INET &&
381 saidx->proxy.sa.sa_family != 0)) {
382
383 DPRINTF(("%s: inner source address %s doesn't "
384 "correspond to expected proxy source %s, "
385 "SA %s/%08lx\n", __func__,
386 inet_ntoa4(ipn.ip_src),
387 ipsp_address(saidx->proxy),
388 ipsp_address(saidx->dst),
389 (u_long) ntohl(sav->spi)));
390
391 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops,
392 V_ahstat.ahs_pdrops,
393 V_ipcompstat.ipcomps_pdrops);
394 error = EACCES;
395 goto bad;
396 }
397 }
398#ifdef INET6
399 /* IPv6-in-IP encapsulation. */
400 if (prot == IPPROTO_IPV6) {
401 struct ip6_hdr ip6n;
402
403 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
404 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
405 V_ahstat.ahs_hdrops,
406 V_ipcompstat.ipcomps_hdrops);
407 error = EINVAL;
408 goto bad;
409 }
410 /* ip6n will now contain the inner IPv6 header. */
411 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
412 (caddr_t) &ip6n);
413
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, V_espstat.esps_pdrops,
434 V_ahstat.ahs_pdrops,
435 V_ipcompstat.ipcomps_pdrops);
436 error = EACCES;
437 goto bad;
438 }
439 }
440#endif /* INET6 */
441#endif /*XXX*/
442
443 /*
444 * Record what we've done to the packet (under what SA it was
445 * processed). If we've been passed an mtag, it means the packet
446 * was already processed by an ethernet/crypto combo card and
447 * thus has a tag attached with all the right information, but
448 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
449 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
450 */
451 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
452 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
453 sizeof(struct tdb_ident), M_NOWAIT);
454 if (mtag == NULL) {
455 DPRINTF(("%s: failed to get tag\n", __func__));
456 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
457 V_ahstat.ahs_hdrops, V_ipcompstat.ipcomps_hdrops);
458 error = ENOMEM;
459 goto bad;
460 }
461
462 tdbi = (struct tdb_ident *)(mtag + 1);
463 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
464 tdbi->proto = sproto;
465 tdbi->spi = sav->spi;
466 /* Cache those two for enc(4) in xform_ipip. */
467 tdbi->alg_auth = sav->alg_auth;
468 tdbi->alg_enc = sav->alg_enc;
469
470 m_tag_prepend(m, mtag);
471 } else if (mt != NULL) {
472 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
473 /* XXX do we need to mark m_flags??? */
474 }
475
476 key_sa_recordxfer(sav, m); /* record data transfer */
477
478#ifdef DEV_ENC
479 encif->if_ipackets++;
480 encif->if_ibytes += m->m_pkthdr.len;
481
482 /*
483 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
484 * packet later after it has been decapsulated.
485 */
486 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE);
487
488 if (prot != IPPROTO_IPIP)
489 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
490 return (error);
491#endif
492
493 /*
494 * Re-dispatch via software interrupt.
495 */
496 if ((error = netisr_queue_src(NETISR_IP, (uintptr_t)sav->spi, m))) {
497 IPSEC_ISTAT(sproto, V_espstat.esps_qfull, V_ahstat.ahs_qfull,
498 V_ipcompstat.ipcomps_qfull);
499
500 DPRINTF(("%s: queue full; proto %u packet dropped\n",
501 __func__, sproto));
502 return error;
503 }
504 return 0;
505bad:
506 m_freem(m);
507 return error;
508}
509
510void
511ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
512{
513 /* XXX nothing just yet */
514}
515#endif /* INET */
516
517#ifdef INET6
518/* IPv6 AH wrapper. */
519int
520ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
521{
522 int l = 0;
523 int protoff;
524 struct ip6_ext ip6e;
525
526 if (*offp < sizeof(struct ip6_hdr)) {
527 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
528 return IPPROTO_DONE;
529 } else if (*offp == sizeof(struct ip6_hdr)) {
530 protoff = offsetof(struct ip6_hdr, ip6_nxt);
531 } else {
532 /* Chase down the header chain... */
533 protoff = sizeof(struct ip6_hdr);
534
535 do {
536 protoff += l;
537 m_copydata(*mp, protoff, sizeof(ip6e),
538 (caddr_t) &ip6e);
539
540 if (ip6e.ip6e_nxt == IPPROTO_AH)
541 l = (ip6e.ip6e_len + 2) << 2;
542 else
543 l = (ip6e.ip6e_len + 1) << 3;
544 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
545 } while (protoff + l < *offp);
546
547 /* Malformed packet check */
548 if (protoff + l != *offp) {
549 DPRINTF(("%s: bad packet header chain, protoff %u, "
550 "l %u, off %u\n", __func__, protoff, l, *offp));
551 IPSEC_ISTAT(proto, V_espstat.esps_hdrops,
552 V_ahstat.ahs_hdrops,
553 V_ipcompstat.ipcomps_hdrops);
554 m_freem(*mp);
555 *mp = NULL;
556 return IPPROTO_DONE;
557 }
558 protoff += offsetof(struct ip6_ext, ip6e_nxt);
559 }
560 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
561 return IPPROTO_DONE;
562}
563
564/*
565 * IPsec input callback, called by the transform callback. Takes care of
566 * filtering and other sanity checks on the processed packet.
567 */
568int
569ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
570 struct m_tag *mt)
571{
572 int prot, af, sproto;
573 struct ip6_hdr *ip6;
574 struct m_tag *mtag;
575 struct tdb_ident *tdbi;
576 struct secasindex *saidx;
577 int nxt;
578 u_int8_t nxt8;
579 int error, nest;
580#ifdef notyet
581 char ip6buf[INET6_ADDRSTRLEN];
582#endif
583
584 IPSEC_ASSERT(m != NULL, ("null mbuf"));
585 IPSEC_ASSERT(sav != NULL, ("null SA"));
586 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
587 saidx = &sav->sah->saidx;
588 af = saidx->dst.sa.sa_family;
589 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
590 sproto = saidx->proto;
591 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
592 sproto == IPPROTO_IPCOMP,
593 ("unexpected security protocol %u", sproto));
594
595 /* Sanity check */
596 if (m == NULL) {
597 DPRINTF(("%s: null mbuf", __func__));
598 IPSEC_ISTAT(sproto, V_espstat.esps_badkcr, V_ahstat.ahs_badkcr,
599 V_ipcompstat.ipcomps_badkcr);
600 error = EINVAL;
601 goto bad;
602 }
603
604 /* Fix IPv6 header */
605 if (m->m_len < sizeof(struct ip6_hdr) &&
606 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
607
608 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
609 __func__, ipsec_address(&sav->sah->saidx.dst),
610 (u_long) ntohl(sav->spi)));
611
612 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
613 V_ipcompstat.ipcomps_hdrops);
614 error = EACCES;
615 goto bad;
616 }
617
618 ip6 = mtod(m, struct ip6_hdr *);
619 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
620
621 /* Save protocol */
622 m_copydata(m, protoff, 1, (unsigned char *) &prot);
623
624#ifdef notyet
625#ifdef INET
626 /* IP-in-IP encapsulation */
627 if (prot == IPPROTO_IPIP) {
628 struct ip ipn;
629
630 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
631 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
632 V_ahstat.ahs_hdrops,
633 V_ipcompstat.ipcomps_hdrops);
634 error = EINVAL;
635 goto bad;
636 }
637 /* ipn will now contain the inner IPv4 header */
638 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
639
640 /*
641 * Check that the inner source address is the same as
642 * the proxy address, if available.
643 */
644 if ((saidx->proxy.sa.sa_family == AF_INET &&
645 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
646 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
647 (saidx->proxy.sa.sa_family != AF_INET &&
648 saidx->proxy.sa.sa_family != 0)) {
649
650 DPRINTF(("%s: inner source address %s doesn't "
651 "correspond to expected proxy source %s, "
652 "SA %s/%08lx\n", __func__,
653 inet_ntoa4(ipn.ip_src),
654 ipsec_address(&saidx->proxy),
655 ipsec_address(&saidx->dst),
656 (u_long) ntohl(sav->spi)));
657
658 IPSEC_ISTATsproto, (V_espstat.esps_pdrops,
659 V_ahstat.ahs_pdrops, V_ipcompstat.ipcomps_pdrops);
660 error = EACCES;
661 goto bad;
662 }
663 }
664#endif /* INET */
665
666 /* IPv6-in-IP encapsulation */
667 if (prot == IPPROTO_IPV6) {
668 struct ip6_hdr ip6n;
669
670 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
671 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
672 V_ahstat.ahs_hdrops,
673 V_ipcompstat.ipcomps_hdrops);
674 error = EINVAL;
675 goto bad;
676 }
677 /* ip6n will now contain the inner IPv6 header. */
678 m_copydata(m, skip, sizeof(struct ip6_hdr),
679 (caddr_t) &ip6n);
680
681 /*
682 * Check that the inner source address is the same as
683 * the proxy address, if available.
684 */
685 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
686 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
687 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
688 &saidx->proxy.sin6.sin6_addr)) ||
689 (saidx->proxy.sa.sa_family != AF_INET6 &&
690 saidx->proxy.sa.sa_family != 0)) {
691
692 DPRINTF(("%s: inner source address %s doesn't "
693 "correspond to expected proxy source %s, "
694 "SA %s/%08lx\n", __func__,
695 ip6_sprintf(ip6buf, &ip6n.ip6_src),
696 ipsec_address(&saidx->proxy),
697 ipsec_address(&saidx->dst),
698 (u_long) ntohl(sav->spi)));
699
700 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops,
701 V_ahstat.ahs_pdrops, V_ipcompstat.ipcomps_pdrops);
702 error = EACCES;
703 goto bad;
704 }
705 }
706#endif /*XXX*/
707
708 /*
709 * Record what we've done to the packet (under what SA it was
710 * processed). If we've been passed an mtag, it means the packet
711 * was already processed by an ethernet/crypto combo card and
712 * thus has a tag attached with all the right information, but
713 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
714 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
715 */
716 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
717 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
718 sizeof(struct tdb_ident), M_NOWAIT);
719 if (mtag == NULL) {
720 DPRINTF(("%s: failed to get tag\n", __func__));
721 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
722 V_ahstat.ahs_hdrops, V_ipcompstat.ipcomps_hdrops);
723 error = ENOMEM;
724 goto bad;
725 }
726
727 tdbi = (struct tdb_ident *)(mtag + 1);
728 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
729 tdbi->proto = sproto;
730 tdbi->spi = sav->spi;
731 /* Cache those two for enc(4) in xform_ipip. */
732 tdbi->alg_auth = sav->alg_auth;
733 tdbi->alg_enc = sav->alg_enc;
734
735 m_tag_prepend(m, mtag);
736 } else {
737 if (mt != NULL)
738 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
739 /* XXX do we need to mark m_flags??? */
740 }
741
742 key_sa_recordxfer(sav, m);
743
744#ifdef DEV_ENC
745 encif->if_ipackets++;
746 encif->if_ibytes += m->m_pkthdr.len;
747
748 /*
749 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
750 * packet later after it has been decapsulated.
751 */
752 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE);
753
754 /* XXX-BZ does not make sense. */
755 if (prot != IPPROTO_IPIP)
756 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
757 return (error);
758#endif
759
760 /* Retrieve new protocol */
761 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
762
763 /*
764 * See the end of ip6_input for this logic.
765 * IPPROTO_IPV[46] case will be processed just like other ones
766 */
767 nest = 0;
768 nxt = nxt8;
769 while (nxt != IPPROTO_DONE) {
770 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
771 IP6STAT_INC(ip6s_toomanyhdr);
772 error = EINVAL;
773 goto bad;
774 }
775
776 /*
777 * Protection against faulty packet - there should be
778 * more sanity checks in header chain processing.
779 */
780 if (m->m_pkthdr.len < skip) {
781 IP6STAT_INC(ip6s_tooshort);
782 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
783 error = EINVAL;
784 goto bad;
785 }
786 /*
787 * Enforce IPsec policy checking if we are seeing last header.
788 * note that we do not visit this with protocols with pcb layer
789 * code - like udp/tcp/raw ip.
790 */
791 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
792 ipsec6_in_reject(m, NULL)) {
793 error = EINVAL;
794 goto bad;
795 }
796 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
797 }
798 return 0;
799bad:
800 if (m)
801 m_freem(m);
802 return error;
803}
804
805void
806esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
807{
808 struct ip6ctlparam *ip6cp = NULL;
809 struct mbuf *m = NULL;
810 struct ip6_hdr *ip6;
811 int off;
812
813 if (sa->sa_family != AF_INET6 ||
814 sa->sa_len != sizeof(struct sockaddr_in6))
815 return;
816 if ((unsigned)cmd >= PRC_NCMDS)
817 return;
818
819 /* if the parameter is from icmp6, decode it. */
820 if (d != NULL) {
821 ip6cp = (struct ip6ctlparam *)d;
822 m = ip6cp->ip6c_m;
823 ip6 = ip6cp->ip6c_ip6;
824 off = ip6cp->ip6c_off;
825 } else {
826 m = NULL;
827 ip6 = NULL;
828 off = 0; /* calm gcc */
829 }
830
831 if (ip6 != NULL) {
832
833 struct ip6ctlparam ip6cp1;
834
835 /*
836 * Notify the error to all possible sockets via pfctlinput2.
837 * Since the upper layer information (such as protocol type,
838 * source and destination ports) is embedded in the encrypted
839 * data and might have been cut, we can't directly call
840 * an upper layer ctlinput function. However, the pcbnotify
841 * function will consider source and destination addresses
842 * as well as the flow info value, and may be able to find
843 * some PCB that should be notified.
844 * Although pfctlinput2 will call esp6_ctlinput(), there is
845 * no possibility of an infinite loop of function calls,
846 * because we don't pass the inner IPv6 header.
847 */
848 bzero(&ip6cp1, sizeof(ip6cp1));
849 ip6cp1.ip6c_src = ip6cp->ip6c_src;
850 pfctlinput2(cmd, sa, (void *)&ip6cp1);
851
852 /*
853 * Then go to special cases that need ESP header information.
854 * XXX: We assume that when ip6 is non NULL,
855 * M and OFF are valid.
856 */
857
858 if (cmd == PRC_MSGSIZE) {
859 struct secasvar *sav;
860 u_int32_t spi;
861 int valid;
862
863 /* check header length before using m_copydata */
864 if (m->m_pkthdr.len < off + sizeof (struct esp))
865 return;
866 m_copydata(m, off + offsetof(struct esp, esp_spi),
867 sizeof(u_int32_t), (caddr_t) &spi);
868 /*
869 * Check to see if we have a valid SA corresponding to
870 * the address in the ICMP message payload.
871 */
872 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
873 IPPROTO_ESP, spi);
874 valid = (sav != NULL);
875 if (sav)
876 KEY_FREESAV(&sav);
877
878 /* XXX Further validation? */
879
880 /*
881 * Depending on whether the SA is "valid" and
882 * routing table size (mtudisc_{hi,lo}wat), we will:
883 * - recalcurate the new MTU and create the
884 * corresponding routing entry, or
885 * - ignore the MTU change notification.
886 */
887 icmp6_mtudisc_update(ip6cp, valid);
888 }
889 } else {
890 /* we normally notify any pcb here */
891 }
892}
893#endif /* INET6 */
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/route.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#ifdef DEV_ENC
98#include <net/if_enc.h>
99#endif
100
101
102#define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \
103 (p) == IPPROTO_AH ? (y)++ : (z)++)
104
105#ifdef INET
106static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
107#endif
108
109/*
110 * ipsec_common_input gets called when an IPsec-protected packet
111 * is received by IPv4 or IPv6. Its job is to find the right SA
112 * and call the appropriate transform. The transform callback
113 * takes care of further processing (like ingress filtering).
114 */
115static int
116ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
117{
118 union sockaddr_union dst_address;
119 struct secasvar *sav;
120 u_int32_t spi;
121 int error;
122#ifdef INET
123#ifdef IPSEC_NAT_T
124 struct m_tag *tag;
125#endif
126#endif
127
128 IPSEC_ISTAT(sproto, V_espstat.esps_input, V_ahstat.ahs_input,
129 V_ipcompstat.ipcomps_input);
130
131 IPSEC_ASSERT(m != NULL, ("null packet"));
132
133 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
134 sproto == IPPROTO_IPCOMP,
135 ("unexpected security protocol %u", sproto));
136
137 if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
138 (sproto == IPPROTO_AH && !V_ah_enable) ||
139 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
140 m_freem(m);
141 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops, V_ahstat.ahs_pdrops,
142 V_ipcompstat.ipcomps_pdrops);
143 return EOPNOTSUPP;
144 }
145
146 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
147 m_freem(m);
148 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
149 V_ipcompstat.ipcomps_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 break;
196#endif /* INET6 */
197 default:
198 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
199 m_freem(m);
200 IPSEC_ISTAT(sproto, V_espstat.esps_nopf, V_ahstat.ahs_nopf,
201 V_ipcompstat.ipcomps_nopf);
202 return EPFNOSUPPORT;
203 }
204
205 /* NB: only pass dst since key_allocsa follows RFC2401 */
206 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
207 if (sav == NULL) {
208 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
209 __func__, ipsec_address(&dst_address),
210 (u_long) ntohl(spi), sproto));
211 IPSEC_ISTAT(sproto, V_espstat.esps_notdb, V_ahstat.ahs_notdb,
212 V_ipcompstat.ipcomps_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, V_espstat.esps_noxform, V_ahstat.ahs_noxform,
222 V_ipcompstat.ipcomps_noxform);
223 KEY_FREESAV(&sav);
224 m_freem(m);
225 return ENXIO;
226 }
227
228 /*
229 * Call appropriate transform and return -- callback takes care of
230 * everything else.
231 */
232 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
233 KEY_FREESAV(&sav);
234 return error;
235}
236
237#ifdef INET
238/*
239 * Common input handler for IPv4 AH, ESP, and IPCOMP.
240 */
241int
242ipsec4_common_input(struct mbuf *m, ...)
243{
244 va_list ap;
245 int off, nxt;
246
247 va_start(ap, m);
248 off = va_arg(ap, int);
249 nxt = va_arg(ap, int);
250 va_end(ap);
251
252 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
253 AF_INET, nxt);
254}
255
256void
257ah4_input(struct mbuf *m, int off)
258{
259 ipsec4_common_input(m, off, IPPROTO_AH);
260}
261void
262ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
263{
264 if (sa->sa_family == AF_INET &&
265 sa->sa_len == sizeof(struct sockaddr_in))
266 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
267}
268
269void
270esp4_input(struct mbuf *m, int off)
271{
272 ipsec4_common_input(m, off, IPPROTO_ESP);
273}
274void
275esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
276{
277 if (sa->sa_family == AF_INET &&
278 sa->sa_len == sizeof(struct sockaddr_in))
279 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
280}
281
282void
283ipcomp4_input(struct mbuf *m, int off)
284{
285 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
286}
287
288/*
289 * IPsec input callback for INET protocols.
290 * This routine is called as the transform callback.
291 * Takes care of filtering and other sanity checks on
292 * the processed packet.
293 */
294int
295ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
296 int skip, int protoff, struct m_tag *mt)
297{
298 int prot, af, sproto;
299 struct ip *ip;
300 struct m_tag *mtag;
301 struct tdb_ident *tdbi;
302 struct secasindex *saidx;
303 int error;
304#ifdef INET6
305#ifdef notyet
306 char ip6buf[INET6_ADDRSTRLEN];
307#endif
308#endif
309
310 IPSEC_ASSERT(m != NULL, ("null mbuf"));
311 IPSEC_ASSERT(sav != NULL, ("null SA"));
312 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
313 saidx = &sav->sah->saidx;
314 af = saidx->dst.sa.sa_family;
315 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
316 sproto = saidx->proto;
317 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
318 sproto == IPPROTO_IPCOMP,
319 ("unexpected security protocol %u", sproto));
320
321 /* Sanity check */
322 if (m == NULL) {
323 DPRINTF(("%s: null mbuf", __func__));
324 IPSEC_ISTAT(sproto, V_espstat.esps_badkcr, V_ahstat.ahs_badkcr,
325 V_ipcompstat.ipcomps_badkcr);
326 KEY_FREESAV(&sav);
327 return EINVAL;
328 }
329
330 if (skip != 0) {
331 /*
332 * Fix IPv4 header
333 * XXXGL: do we need this entire block?
334 */
335 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
336 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
337 __func__, ipsec_address(&sav->sah->saidx.dst),
338 (u_long) ntohl(sav->spi)));
339 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
340 V_ipcompstat.ipcomps_hdrops);
341 error = ENOBUFS;
342 goto bad;
343 }
344
345 ip = mtod(m, struct ip *);
346 ip->ip_len = htons(m->m_pkthdr.len);
347 ip->ip_sum = 0;
348 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
349 } else {
350 ip = mtod(m, struct ip *);
351 }
352 prot = ip->ip_p;
353
354#ifdef notyet
355 /* IP-in-IP encapsulation */
356 if (prot == IPPROTO_IPIP) {
357 struct ip ipn;
358
359 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
360 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
361 V_ahstat.ahs_hdrops,
362 V_ipcompstat.ipcomps_hdrops);
363 error = EINVAL;
364 goto bad;
365 }
366 /* ipn will now contain the inner IPv4 header */
367 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
368 (caddr_t) &ipn);
369
370 /* XXX PROXY address isn't recorded in SAH */
371 /*
372 * Check that the inner source address is the same as
373 * the proxy address, if available.
374 */
375 if ((saidx->proxy.sa.sa_family == AF_INET &&
376 saidx->proxy.sin.sin_addr.s_addr !=
377 INADDR_ANY &&
378 ipn.ip_src.s_addr !=
379 saidx->proxy.sin.sin_addr.s_addr) ||
380 (saidx->proxy.sa.sa_family != AF_INET &&
381 saidx->proxy.sa.sa_family != 0)) {
382
383 DPRINTF(("%s: inner source address %s doesn't "
384 "correspond to expected proxy source %s, "
385 "SA %s/%08lx\n", __func__,
386 inet_ntoa4(ipn.ip_src),
387 ipsp_address(saidx->proxy),
388 ipsp_address(saidx->dst),
389 (u_long) ntohl(sav->spi)));
390
391 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops,
392 V_ahstat.ahs_pdrops,
393 V_ipcompstat.ipcomps_pdrops);
394 error = EACCES;
395 goto bad;
396 }
397 }
398#ifdef INET6
399 /* IPv6-in-IP encapsulation. */
400 if (prot == IPPROTO_IPV6) {
401 struct ip6_hdr ip6n;
402
403 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
404 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
405 V_ahstat.ahs_hdrops,
406 V_ipcompstat.ipcomps_hdrops);
407 error = EINVAL;
408 goto bad;
409 }
410 /* ip6n will now contain the inner IPv6 header. */
411 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
412 (caddr_t) &ip6n);
413
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, V_espstat.esps_pdrops,
434 V_ahstat.ahs_pdrops,
435 V_ipcompstat.ipcomps_pdrops);
436 error = EACCES;
437 goto bad;
438 }
439 }
440#endif /* INET6 */
441#endif /*XXX*/
442
443 /*
444 * Record what we've done to the packet (under what SA it was
445 * processed). If we've been passed an mtag, it means the packet
446 * was already processed by an ethernet/crypto combo card and
447 * thus has a tag attached with all the right information, but
448 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
449 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
450 */
451 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
452 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
453 sizeof(struct tdb_ident), M_NOWAIT);
454 if (mtag == NULL) {
455 DPRINTF(("%s: failed to get tag\n", __func__));
456 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
457 V_ahstat.ahs_hdrops, V_ipcompstat.ipcomps_hdrops);
458 error = ENOMEM;
459 goto bad;
460 }
461
462 tdbi = (struct tdb_ident *)(mtag + 1);
463 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
464 tdbi->proto = sproto;
465 tdbi->spi = sav->spi;
466 /* Cache those two for enc(4) in xform_ipip. */
467 tdbi->alg_auth = sav->alg_auth;
468 tdbi->alg_enc = sav->alg_enc;
469
470 m_tag_prepend(m, mtag);
471 } else if (mt != NULL) {
472 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
473 /* XXX do we need to mark m_flags??? */
474 }
475
476 key_sa_recordxfer(sav, m); /* record data transfer */
477
478#ifdef DEV_ENC
479 encif->if_ipackets++;
480 encif->if_ibytes += m->m_pkthdr.len;
481
482 /*
483 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
484 * packet later after it has been decapsulated.
485 */
486 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE);
487
488 if (prot != IPPROTO_IPIP)
489 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
490 return (error);
491#endif
492
493 /*
494 * Re-dispatch via software interrupt.
495 */
496 if ((error = netisr_queue_src(NETISR_IP, (uintptr_t)sav->spi, m))) {
497 IPSEC_ISTAT(sproto, V_espstat.esps_qfull, V_ahstat.ahs_qfull,
498 V_ipcompstat.ipcomps_qfull);
499
500 DPRINTF(("%s: queue full; proto %u packet dropped\n",
501 __func__, sproto));
502 return error;
503 }
504 return 0;
505bad:
506 m_freem(m);
507 return error;
508}
509
510void
511ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
512{
513 /* XXX nothing just yet */
514}
515#endif /* INET */
516
517#ifdef INET6
518/* IPv6 AH wrapper. */
519int
520ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
521{
522 int l = 0;
523 int protoff;
524 struct ip6_ext ip6e;
525
526 if (*offp < sizeof(struct ip6_hdr)) {
527 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
528 return IPPROTO_DONE;
529 } else if (*offp == sizeof(struct ip6_hdr)) {
530 protoff = offsetof(struct ip6_hdr, ip6_nxt);
531 } else {
532 /* Chase down the header chain... */
533 protoff = sizeof(struct ip6_hdr);
534
535 do {
536 protoff += l;
537 m_copydata(*mp, protoff, sizeof(ip6e),
538 (caddr_t) &ip6e);
539
540 if (ip6e.ip6e_nxt == IPPROTO_AH)
541 l = (ip6e.ip6e_len + 2) << 2;
542 else
543 l = (ip6e.ip6e_len + 1) << 3;
544 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
545 } while (protoff + l < *offp);
546
547 /* Malformed packet check */
548 if (protoff + l != *offp) {
549 DPRINTF(("%s: bad packet header chain, protoff %u, "
550 "l %u, off %u\n", __func__, protoff, l, *offp));
551 IPSEC_ISTAT(proto, V_espstat.esps_hdrops,
552 V_ahstat.ahs_hdrops,
553 V_ipcompstat.ipcomps_hdrops);
554 m_freem(*mp);
555 *mp = NULL;
556 return IPPROTO_DONE;
557 }
558 protoff += offsetof(struct ip6_ext, ip6e_nxt);
559 }
560 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
561 return IPPROTO_DONE;
562}
563
564/*
565 * IPsec input callback, called by the transform callback. Takes care of
566 * filtering and other sanity checks on the processed packet.
567 */
568int
569ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
570 struct m_tag *mt)
571{
572 int prot, af, sproto;
573 struct ip6_hdr *ip6;
574 struct m_tag *mtag;
575 struct tdb_ident *tdbi;
576 struct secasindex *saidx;
577 int nxt;
578 u_int8_t nxt8;
579 int error, nest;
580#ifdef notyet
581 char ip6buf[INET6_ADDRSTRLEN];
582#endif
583
584 IPSEC_ASSERT(m != NULL, ("null mbuf"));
585 IPSEC_ASSERT(sav != NULL, ("null SA"));
586 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
587 saidx = &sav->sah->saidx;
588 af = saidx->dst.sa.sa_family;
589 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
590 sproto = saidx->proto;
591 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
592 sproto == IPPROTO_IPCOMP,
593 ("unexpected security protocol %u", sproto));
594
595 /* Sanity check */
596 if (m == NULL) {
597 DPRINTF(("%s: null mbuf", __func__));
598 IPSEC_ISTAT(sproto, V_espstat.esps_badkcr, V_ahstat.ahs_badkcr,
599 V_ipcompstat.ipcomps_badkcr);
600 error = EINVAL;
601 goto bad;
602 }
603
604 /* Fix IPv6 header */
605 if (m->m_len < sizeof(struct ip6_hdr) &&
606 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
607
608 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
609 __func__, ipsec_address(&sav->sah->saidx.dst),
610 (u_long) ntohl(sav->spi)));
611
612 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
613 V_ipcompstat.ipcomps_hdrops);
614 error = EACCES;
615 goto bad;
616 }
617
618 ip6 = mtod(m, struct ip6_hdr *);
619 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
620
621 /* Save protocol */
622 m_copydata(m, protoff, 1, (unsigned char *) &prot);
623
624#ifdef notyet
625#ifdef INET
626 /* IP-in-IP encapsulation */
627 if (prot == IPPROTO_IPIP) {
628 struct ip ipn;
629
630 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
631 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
632 V_ahstat.ahs_hdrops,
633 V_ipcompstat.ipcomps_hdrops);
634 error = EINVAL;
635 goto bad;
636 }
637 /* ipn will now contain the inner IPv4 header */
638 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
639
640 /*
641 * Check that the inner source address is the same as
642 * the proxy address, if available.
643 */
644 if ((saidx->proxy.sa.sa_family == AF_INET &&
645 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
646 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
647 (saidx->proxy.sa.sa_family != AF_INET &&
648 saidx->proxy.sa.sa_family != 0)) {
649
650 DPRINTF(("%s: inner source address %s doesn't "
651 "correspond to expected proxy source %s, "
652 "SA %s/%08lx\n", __func__,
653 inet_ntoa4(ipn.ip_src),
654 ipsec_address(&saidx->proxy),
655 ipsec_address(&saidx->dst),
656 (u_long) ntohl(sav->spi)));
657
658 IPSEC_ISTATsproto, (V_espstat.esps_pdrops,
659 V_ahstat.ahs_pdrops, V_ipcompstat.ipcomps_pdrops);
660 error = EACCES;
661 goto bad;
662 }
663 }
664#endif /* INET */
665
666 /* IPv6-in-IP encapsulation */
667 if (prot == IPPROTO_IPV6) {
668 struct ip6_hdr ip6n;
669
670 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
671 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
672 V_ahstat.ahs_hdrops,
673 V_ipcompstat.ipcomps_hdrops);
674 error = EINVAL;
675 goto bad;
676 }
677 /* ip6n will now contain the inner IPv6 header. */
678 m_copydata(m, skip, sizeof(struct ip6_hdr),
679 (caddr_t) &ip6n);
680
681 /*
682 * Check that the inner source address is the same as
683 * the proxy address, if available.
684 */
685 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
686 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
687 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
688 &saidx->proxy.sin6.sin6_addr)) ||
689 (saidx->proxy.sa.sa_family != AF_INET6 &&
690 saidx->proxy.sa.sa_family != 0)) {
691
692 DPRINTF(("%s: inner source address %s doesn't "
693 "correspond to expected proxy source %s, "
694 "SA %s/%08lx\n", __func__,
695 ip6_sprintf(ip6buf, &ip6n.ip6_src),
696 ipsec_address(&saidx->proxy),
697 ipsec_address(&saidx->dst),
698 (u_long) ntohl(sav->spi)));
699
700 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops,
701 V_ahstat.ahs_pdrops, V_ipcompstat.ipcomps_pdrops);
702 error = EACCES;
703 goto bad;
704 }
705 }
706#endif /*XXX*/
707
708 /*
709 * Record what we've done to the packet (under what SA it was
710 * processed). If we've been passed an mtag, it means the packet
711 * was already processed by an ethernet/crypto combo card and
712 * thus has a tag attached with all the right information, but
713 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
714 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
715 */
716 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
717 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
718 sizeof(struct tdb_ident), M_NOWAIT);
719 if (mtag == NULL) {
720 DPRINTF(("%s: failed to get tag\n", __func__));
721 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
722 V_ahstat.ahs_hdrops, V_ipcompstat.ipcomps_hdrops);
723 error = ENOMEM;
724 goto bad;
725 }
726
727 tdbi = (struct tdb_ident *)(mtag + 1);
728 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
729 tdbi->proto = sproto;
730 tdbi->spi = sav->spi;
731 /* Cache those two for enc(4) in xform_ipip. */
732 tdbi->alg_auth = sav->alg_auth;
733 tdbi->alg_enc = sav->alg_enc;
734
735 m_tag_prepend(m, mtag);
736 } else {
737 if (mt != NULL)
738 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
739 /* XXX do we need to mark m_flags??? */
740 }
741
742 key_sa_recordxfer(sav, m);
743
744#ifdef DEV_ENC
745 encif->if_ipackets++;
746 encif->if_ibytes += m->m_pkthdr.len;
747
748 /*
749 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
750 * packet later after it has been decapsulated.
751 */
752 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE);
753
754 /* XXX-BZ does not make sense. */
755 if (prot != IPPROTO_IPIP)
756 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
757 return (error);
758#endif
759
760 /* Retrieve new protocol */
761 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
762
763 /*
764 * See the end of ip6_input for this logic.
765 * IPPROTO_IPV[46] case will be processed just like other ones
766 */
767 nest = 0;
768 nxt = nxt8;
769 while (nxt != IPPROTO_DONE) {
770 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
771 IP6STAT_INC(ip6s_toomanyhdr);
772 error = EINVAL;
773 goto bad;
774 }
775
776 /*
777 * Protection against faulty packet - there should be
778 * more sanity checks in header chain processing.
779 */
780 if (m->m_pkthdr.len < skip) {
781 IP6STAT_INC(ip6s_tooshort);
782 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
783 error = EINVAL;
784 goto bad;
785 }
786 /*
787 * Enforce IPsec policy checking if we are seeing last header.
788 * note that we do not visit this with protocols with pcb layer
789 * code - like udp/tcp/raw ip.
790 */
791 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
792 ipsec6_in_reject(m, NULL)) {
793 error = EINVAL;
794 goto bad;
795 }
796 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
797 }
798 return 0;
799bad:
800 if (m)
801 m_freem(m);
802 return error;
803}
804
805void
806esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
807{
808 struct ip6ctlparam *ip6cp = NULL;
809 struct mbuf *m = NULL;
810 struct ip6_hdr *ip6;
811 int off;
812
813 if (sa->sa_family != AF_INET6 ||
814 sa->sa_len != sizeof(struct sockaddr_in6))
815 return;
816 if ((unsigned)cmd >= PRC_NCMDS)
817 return;
818
819 /* if the parameter is from icmp6, decode it. */
820 if (d != NULL) {
821 ip6cp = (struct ip6ctlparam *)d;
822 m = ip6cp->ip6c_m;
823 ip6 = ip6cp->ip6c_ip6;
824 off = ip6cp->ip6c_off;
825 } else {
826 m = NULL;
827 ip6 = NULL;
828 off = 0; /* calm gcc */
829 }
830
831 if (ip6 != NULL) {
832
833 struct ip6ctlparam ip6cp1;
834
835 /*
836 * Notify the error to all possible sockets via pfctlinput2.
837 * Since the upper layer information (such as protocol type,
838 * source and destination ports) is embedded in the encrypted
839 * data and might have been cut, we can't directly call
840 * an upper layer ctlinput function. However, the pcbnotify
841 * function will consider source and destination addresses
842 * as well as the flow info value, and may be able to find
843 * some PCB that should be notified.
844 * Although pfctlinput2 will call esp6_ctlinput(), there is
845 * no possibility of an infinite loop of function calls,
846 * because we don't pass the inner IPv6 header.
847 */
848 bzero(&ip6cp1, sizeof(ip6cp1));
849 ip6cp1.ip6c_src = ip6cp->ip6c_src;
850 pfctlinput2(cmd, sa, (void *)&ip6cp1);
851
852 /*
853 * Then go to special cases that need ESP header information.
854 * XXX: We assume that when ip6 is non NULL,
855 * M and OFF are valid.
856 */
857
858 if (cmd == PRC_MSGSIZE) {
859 struct secasvar *sav;
860 u_int32_t spi;
861 int valid;
862
863 /* check header length before using m_copydata */
864 if (m->m_pkthdr.len < off + sizeof (struct esp))
865 return;
866 m_copydata(m, off + offsetof(struct esp, esp_spi),
867 sizeof(u_int32_t), (caddr_t) &spi);
868 /*
869 * Check to see if we have a valid SA corresponding to
870 * the address in the ICMP message payload.
871 */
872 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
873 IPPROTO_ESP, spi);
874 valid = (sav != NULL);
875 if (sav)
876 KEY_FREESAV(&sav);
877
878 /* XXX Further validation? */
879
880 /*
881 * Depending on whether the SA is "valid" and
882 * routing table size (mtudisc_{hi,lo}wat), we will:
883 * - recalcurate the new MTU and create the
884 * corresponding routing entry, or
885 * - ignore the MTU change notification.
886 */
887 icmp6_mtudisc_update(ip6cp, valid);
888 }
889 } else {
890 /* we normally notify any pcb here */
891 }
892}
893#endif /* INET6 */