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/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
106 static 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. It's 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 */
115 static int
116 ipsec_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 IPSEC_NAT_T
123 struct m_tag *tag;
124 #endif
125
126 IPSEC_ISTAT(sproto, V_espstat.esps_input, V_ahstat.ahs_input,
127 V_ipcompstat.ipcomps_input);
128
129 IPSEC_ASSERT(m != NULL, ("null packet"));
130
131 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
132 sproto == IPPROTO_IPCOMP,
133 ("unexpected security protocol %u", sproto));
134
135 if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
136 (sproto == IPPROTO_AH && !V_ah_enable) ||
137 (sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
138 m_freem(m);
139 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops, V_ahstat.ahs_pdrops,
140 V_ipcompstat.ipcomps_pdrops);
141 return EOPNOTSUPP;
142 }
143
144 if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
145 m_freem(m);
146 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
147 V_ipcompstat.ipcomps_hdrops);
148 DPRINTF(("%s: packet too small\n", __func__));
149 return EINVAL;
150 }
151
152 /* Retrieve the SPI from the relevant IPsec header */
153 if (sproto == IPPROTO_ESP)
154 m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
155 else if (sproto == IPPROTO_AH)
156 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
157 (caddr_t) &spi);
158 else if (sproto == IPPROTO_IPCOMP) {
159 u_int16_t cpi;
160 m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
161 (caddr_t) &cpi);
162 spi = ntohl(htons(cpi));
163 }
164
165 /*
166 * Find the SA and (indirectly) call the appropriate
167 * kernel crypto routine. The resulting mbuf chain is a valid
168 * IP packet ready to go through input processing.
169 */
170 bzero(&dst_address, sizeof (dst_address));
171 dst_address.sa.sa_family = af;
172 switch (af) {
173 #ifdef INET
174 case AF_INET:
175 dst_address.sin.sin_len = sizeof(struct sockaddr_in);
176 m_copydata(m, offsetof(struct ip, ip_dst),
177 sizeof(struct in_addr),
178 (caddr_t) &dst_address.sin.sin_addr);
179 #ifdef IPSEC_NAT_T
180 /* Find the source port for NAT-T; see udp*_espdecap. */
181 tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL);
182 if (tag != NULL)
183 dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1];
184 #endif /* IPSEC_NAT_T */
185 break;
186 #endif /* INET */
187 #ifdef INET6
188 case AF_INET6:
189 dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
190 m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
191 sizeof(struct in6_addr),
192 (caddr_t) &dst_address.sin6.sin6_addr);
193 break;
194 #endif /* INET6 */
195 default:
196 DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
197 m_freem(m);
198 IPSEC_ISTAT(sproto, V_espstat.esps_nopf, V_ahstat.ahs_nopf,
199 V_ipcompstat.ipcomps_nopf);
200 return EPFNOSUPPORT;
201 }
202
203 /* NB: only pass dst since key_allocsa follows RFC2401 */
204 sav = KEY_ALLOCSA(&dst_address, sproto, spi);
205 if (sav == NULL) {
206 DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
207 __func__, ipsec_address(&dst_address),
208 (u_long) ntohl(spi), sproto));
209 IPSEC_ISTAT(sproto, V_espstat.esps_notdb, V_ahstat.ahs_notdb,
210 V_ipcompstat.ipcomps_notdb);
211 m_freem(m);
212 return ENOENT;
213 }
214
215 if (sav->tdb_xform == NULL) {
216 DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
217 __func__, ipsec_address(&dst_address),
218 (u_long) ntohl(spi), sproto));
219 IPSEC_ISTAT(sproto, V_espstat.esps_noxform, V_ahstat.ahs_noxform,
220 V_ipcompstat.ipcomps_noxform);
221 KEY_FREESAV(&sav);
222 m_freem(m);
223 return ENXIO;
224 }
225
226 /*
227 * Call appropriate transform and return -- callback takes care of
228 * everything else.
229 */
230 error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
231 KEY_FREESAV(&sav);
232 return error;
233 }
234
235 #ifdef INET
236 /*
237 * Common input handler for IPv4 AH, ESP, and IPCOMP.
238 */
239 int
240 ipsec4_common_input(struct mbuf *m, ...)
241 {
242 va_list ap;
243 int off, nxt;
244
245 va_start(ap, m);
246 off = va_arg(ap, int);
247 nxt = va_arg(ap, int);
248 va_end(ap);
249
250 return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
251 AF_INET, nxt);
252 }
253
254 void
255 ah4_input(struct mbuf *m, int off)
256 {
257 ipsec4_common_input(m, off, IPPROTO_AH);
258 }
259 void
260 ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
261 {
262 if (sa->sa_family == AF_INET &&
263 sa->sa_len == sizeof(struct sockaddr_in))
264 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
265 }
266
267 void
268 esp4_input(struct mbuf *m, int off)
269 {
270 ipsec4_common_input(m, off, IPPROTO_ESP);
271 }
272 void
273 esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
274 {
275 if (sa->sa_family == AF_INET &&
276 sa->sa_len == sizeof(struct sockaddr_in))
277 ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
278 }
279
280 void
281 ipcomp4_input(struct mbuf *m, int off)
282 {
283 ipsec4_common_input(m, off, IPPROTO_IPCOMP);
284 }
285
286 /*
287 * IPsec input callback for INET protocols.
288 * This routine is called as the transform callback.
289 * Takes care of filtering and other sanity checks on
290 * the processed packet.
291 */
292 int
293 ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
294 int skip, int protoff, struct m_tag *mt)
295 {
296 int prot, af, sproto;
297 struct ip *ip;
298 struct m_tag *mtag;
299 struct tdb_ident *tdbi;
300 struct secasindex *saidx;
301 int error;
302 #ifdef INET6
303 #ifdef notyet
304 char ip6buf[INET6_ADDRSTRLEN];
305 #endif
306 #endif
307
308 IPSEC_ASSERT(m != NULL, ("null mbuf"));
309 IPSEC_ASSERT(sav != NULL, ("null SA"));
310 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
311 saidx = &sav->sah->saidx;
312 af = saidx->dst.sa.sa_family;
313 IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
314 sproto = saidx->proto;
315 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
316 sproto == IPPROTO_IPCOMP,
317 ("unexpected security protocol %u", sproto));
318
319 /* Sanity check */
320 if (m == NULL) {
321 DPRINTF(("%s: null mbuf", __func__));
322 IPSEC_ISTAT(sproto, V_espstat.esps_badkcr, V_ahstat.ahs_badkcr,
323 V_ipcompstat.ipcomps_badkcr);
324 KEY_FREESAV(&sav);
325 return EINVAL;
326 }
327
328 if (skip != 0) {
329 /* Fix IPv4 header */
330 if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
331 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
332 __func__, ipsec_address(&sav->sah->saidx.dst),
333 (u_long) ntohl(sav->spi)));
334 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
335 V_ipcompstat.ipcomps_hdrops);
336 error = ENOBUFS;
337 goto bad;
338 }
339
340 ip = mtod(m, struct ip *);
341 ip->ip_len = htons(m->m_pkthdr.len);
342 ip->ip_off = htons(ip->ip_off);
343 ip->ip_sum = 0;
344 ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
345 } else {
346 ip = mtod(m, struct ip *);
347 }
348 prot = ip->ip_p;
349
350 #ifdef notyet
351 /* IP-in-IP encapsulation */
352 if (prot == IPPROTO_IPIP) {
353 struct ip ipn;
354
355 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
356 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
357 V_ahstat.ahs_hdrops,
358 V_ipcompstat.ipcomps_hdrops);
359 error = EINVAL;
360 goto bad;
361 }
362 /* ipn will now contain the inner IPv4 header */
363 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
364 (caddr_t) &ipn);
365
366 /* XXX PROXY address isn't recorded in SAH */
367 /*
368 * Check that the inner source address is the same as
369 * the proxy address, if available.
370 */
371 if ((saidx->proxy.sa.sa_family == AF_INET &&
372 saidx->proxy.sin.sin_addr.s_addr !=
373 INADDR_ANY &&
374 ipn.ip_src.s_addr !=
375 saidx->proxy.sin.sin_addr.s_addr) ||
376 (saidx->proxy.sa.sa_family != AF_INET &&
377 saidx->proxy.sa.sa_family != 0)) {
378
379 DPRINTF(("%s: inner source address %s doesn't "
380 "correspond to expected proxy source %s, "
381 "SA %s/%08lx\n", __func__,
382 inet_ntoa4(ipn.ip_src),
383 ipsp_address(saidx->proxy),
384 ipsp_address(saidx->dst),
385 (u_long) ntohl(sav->spi)));
386
387 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops,
388 V_ahstat.ahs_pdrops,
389 V_ipcompstat.ipcomps_pdrops);
390 error = EACCES;
391 goto bad;
392 }
393 }
394 #ifdef INET6
395 /* IPv6-in-IP encapsulation. */
396 if (prot == IPPROTO_IPV6) {
397 struct ip6_hdr ip6n;
398
399 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
400 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
401 V_ahstat.ahs_hdrops,
402 V_ipcompstat.ipcomps_hdrops);
403 error = EINVAL;
404 goto bad;
405 }
406 /* ip6n will now contain the inner IPv6 header. */
407 m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
408 (caddr_t) &ip6n);
409
410 /*
411 * Check that the inner source address is the same as
412 * the proxy address, if available.
413 */
414 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
415 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
416 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
417 &saidx->proxy.sin6.sin6_addr)) ||
418 (saidx->proxy.sa.sa_family != AF_INET6 &&
419 saidx->proxy.sa.sa_family != 0)) {
420
421 DPRINTF(("%s: inner source address %s doesn't "
422 "correspond to expected proxy source %s, "
423 "SA %s/%08lx\n", __func__,
424 ip6_sprintf(ip6buf, &ip6n.ip6_src),
425 ipsec_address(&saidx->proxy),
426 ipsec_address(&saidx->dst),
427 (u_long) ntohl(sav->spi)));
428
429 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops,
430 V_ahstat.ahs_pdrops,
431 V_ipcompstat.ipcomps_pdrops);
432 error = EACCES;
433 goto bad;
434 }
435 }
436 #endif /* INET6 */
437 #endif /*XXX*/
438
439 /*
440 * Record what we've done to the packet (under what SA it was
441 * processed). If we've been passed an mtag, it means the packet
442 * was already processed by an ethernet/crypto combo card and
443 * thus has a tag attached with all the right information, but
444 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
445 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
446 */
447 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
448 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
449 sizeof(struct tdb_ident), M_NOWAIT);
450 if (mtag == NULL) {
451 DPRINTF(("%s: failed to get tag\n", __func__));
452 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
453 V_ahstat.ahs_hdrops, V_ipcompstat.ipcomps_hdrops);
454 error = ENOMEM;
455 goto bad;
456 }
457
458 tdbi = (struct tdb_ident *)(mtag + 1);
459 bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
460 tdbi->proto = sproto;
461 tdbi->spi = sav->spi;
462 /* Cache those two for enc(4) in xform_ipip. */
463 tdbi->alg_auth = sav->alg_auth;
464 tdbi->alg_enc = sav->alg_enc;
465
466 m_tag_prepend(m, mtag);
467 } else if (mt != NULL) {
468 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
469 /* XXX do we need to mark m_flags??? */
470 }
471
472 key_sa_recordxfer(sav, m); /* record data transfer */
473
474 #ifdef DEV_ENC
475 encif->if_ipackets++;
476 encif->if_ibytes += m->m_pkthdr.len;
477
478 /*
479 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
480 * packet later after it has been decapsulated.
481 */
482 ipsec_bpf(m, sav, AF_INET, ENC_IN|ENC_BEFORE);
483
484 if (prot != IPPROTO_IPIP)
485 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
486 return (error);
487 #endif
488
489 /*
490 * Re-dispatch via software interrupt.
491 */
492 if ((error = netisr_queue_src(NETISR_IP, (uintptr_t)sav->spi, m))) {
493 IPSEC_ISTAT(sproto, V_espstat.esps_qfull, V_ahstat.ahs_qfull,
494 V_ipcompstat.ipcomps_qfull);
495
496 DPRINTF(("%s: queue full; proto %u packet dropped\n",
497 __func__, sproto));
498 return error;
499 }
500 return 0;
501 bad:
502 m_freem(m);
503 return error;
504 }
505
506 void
507 ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
508 {
509 /* XXX nothing just yet */
510 }
511 #endif /* INET */
512
513 #ifdef INET6
514 /* IPv6 AH wrapper. */
515 int
516 ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
517 {
518 int l = 0;
519 int protoff;
520 struct ip6_ext ip6e;
521
522 if (*offp < sizeof(struct ip6_hdr)) {
523 DPRINTF(("%s: bad offset %u\n", __func__, *offp));
524 return IPPROTO_DONE;
525 } else if (*offp == sizeof(struct ip6_hdr)) {
526 protoff = offsetof(struct ip6_hdr, ip6_nxt);
527 } else {
528 /* Chase down the header chain... */
529 protoff = sizeof(struct ip6_hdr);
530
531 do {
532 protoff += l;
533 m_copydata(*mp, protoff, sizeof(ip6e),
534 (caddr_t) &ip6e);
535
536 if (ip6e.ip6e_nxt == IPPROTO_AH)
537 l = (ip6e.ip6e_len + 2) << 2;
538 else
539 l = (ip6e.ip6e_len + 1) << 3;
540 IPSEC_ASSERT(l > 0, ("l went zero or negative"));
541 } while (protoff + l < *offp);
542
543 /* Malformed packet check */
544 if (protoff + l != *offp) {
545 DPRINTF(("%s: bad packet header chain, protoff %u, "
546 "l %u, off %u\n", __func__, protoff, l, *offp));
547 IPSEC_ISTAT(proto, V_espstat.esps_hdrops,
548 V_ahstat.ahs_hdrops,
549 V_ipcompstat.ipcomps_hdrops);
550 m_freem(*mp);
551 *mp = NULL;
552 return IPPROTO_DONE;
553 }
554 protoff += offsetof(struct ip6_ext, ip6e_nxt);
555 }
556 (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
557 return IPPROTO_DONE;
558 }
559
560 /*
561 * IPsec input callback, called by the transform callback. Takes care of
562 * filtering and other sanity checks on the processed packet.
563 */
564 int
565 ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
566 struct m_tag *mt)
567 {
568 int prot, af, sproto;
569 struct ip6_hdr *ip6;
570 struct m_tag *mtag;
571 struct tdb_ident *tdbi;
572 struct secasindex *saidx;
573 int nxt;
574 u_int8_t nxt8;
575 int error, nest;
576 #ifdef notyet
577 char ip6buf[INET6_ADDRSTRLEN];
578 #endif
579
580 IPSEC_ASSERT(m != NULL, ("null mbuf"));
581 IPSEC_ASSERT(sav != NULL, ("null SA"));
582 IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
583 saidx = &sav->sah->saidx;
584 af = saidx->dst.sa.sa_family;
585 IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
586 sproto = saidx->proto;
587 IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
588 sproto == IPPROTO_IPCOMP,
589 ("unexpected security protocol %u", sproto));
590
591 /* Sanity check */
592 if (m == NULL) {
593 DPRINTF(("%s: null mbuf", __func__));
594 IPSEC_ISTAT(sproto, V_espstat.esps_badkcr, V_ahstat.ahs_badkcr,
595 V_ipcompstat.ipcomps_badkcr);
596 error = EINVAL;
597 goto bad;
598 }
599
600 /* Fix IPv6 header */
601 if (m->m_len < sizeof(struct ip6_hdr) &&
602 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
603
604 DPRINTF(("%s: processing failed for SA %s/%08lx\n",
605 __func__, ipsec_address(&sav->sah->saidx.dst),
606 (u_long) ntohl(sav->spi)));
607
608 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops, V_ahstat.ahs_hdrops,
609 V_ipcompstat.ipcomps_hdrops);
610 error = EACCES;
611 goto bad;
612 }
613
614 ip6 = mtod(m, struct ip6_hdr *);
615 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
616
617 /* Save protocol */
618 prot = 0;
619 m_copydata(m, protoff, 1, (unsigned char *) &prot);
620
621 #ifdef notyet
622 #ifdef INET
623 /* IP-in-IP encapsulation */
624 if (prot == IPPROTO_IPIP) {
625 struct ip ipn;
626
627 if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
628 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
629 V_ahstat.ahs_hdrops,
630 V_ipcompstat.ipcomps_hdrops);
631 error = EINVAL;
632 goto bad;
633 }
634 /* ipn will now contain the inner IPv4 header */
635 m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
636
637 /*
638 * Check that the inner source address is the same as
639 * the proxy address, if available.
640 */
641 if ((saidx->proxy.sa.sa_family == AF_INET &&
642 saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
643 ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
644 (saidx->proxy.sa.sa_family != AF_INET &&
645 saidx->proxy.sa.sa_family != 0)) {
646
647 DPRINTF(("%s: inner source address %s doesn't "
648 "correspond to expected proxy source %s, "
649 "SA %s/%08lx\n", __func__,
650 inet_ntoa4(ipn.ip_src),
651 ipsec_address(&saidx->proxy),
652 ipsec_address(&saidx->dst),
653 (u_long) ntohl(sav->spi)));
654
655 IPSEC_ISTATsproto, (V_espstat.esps_pdrops,
656 V_ahstat.ahs_pdrops, V_ipcompstat.ipcomps_pdrops);
657 error = EACCES;
658 goto bad;
659 }
660 }
661 #endif /* INET */
662
663 /* IPv6-in-IP encapsulation */
664 if (prot == IPPROTO_IPV6) {
665 struct ip6_hdr ip6n;
666
667 if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
668 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
669 V_ahstat.ahs_hdrops,
670 V_ipcompstat.ipcomps_hdrops);
671 error = EINVAL;
672 goto bad;
673 }
674 /* ip6n will now contain the inner IPv6 header. */
675 m_copydata(m, skip, sizeof(struct ip6_hdr),
676 (caddr_t) &ip6n);
677
678 /*
679 * Check that the inner source address is the same as
680 * the proxy address, if available.
681 */
682 if ((saidx->proxy.sa.sa_family == AF_INET6 &&
683 !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
684 !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
685 &saidx->proxy.sin6.sin6_addr)) ||
686 (saidx->proxy.sa.sa_family != AF_INET6 &&
687 saidx->proxy.sa.sa_family != 0)) {
688
689 DPRINTF(("%s: inner source address %s doesn't "
690 "correspond to expected proxy source %s, "
691 "SA %s/%08lx\n", __func__,
692 ip6_sprintf(ip6buf, &ip6n.ip6_src),
693 ipsec_address(&saidx->proxy),
694 ipsec_address(&saidx->dst),
695 (u_long) ntohl(sav->spi)));
696
697 IPSEC_ISTAT(sproto, V_espstat.esps_pdrops,
698 V_ahstat.ahs_pdrops, V_ipcompstat.ipcomps_pdrops);
699 error = EACCES;
700 goto bad;
701 }
702 }
703 #endif /*XXX*/
704
705 /*
706 * Record what we've done to the packet (under what SA it was
707 * processed). If we've been passed an mtag, it means the packet
708 * was already processed by an ethernet/crypto combo card and
709 * thus has a tag attached with all the right information, but
710 * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
711 * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
712 */
713 if (mt == NULL && sproto != IPPROTO_IPCOMP) {
714 mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
715 sizeof(struct tdb_ident), M_NOWAIT);
716 if (mtag == NULL) {
717 DPRINTF(("%s: failed to get tag\n", __func__));
718 IPSEC_ISTAT(sproto, V_espstat.esps_hdrops,
719 V_ahstat.ahs_hdrops, V_ipcompstat.ipcomps_hdrops);
720 error = ENOMEM;
721 goto bad;
722 }
723
724 tdbi = (struct tdb_ident *)(mtag + 1);
725 bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
726 tdbi->proto = sproto;
727 tdbi->spi = sav->spi;
728 /* Cache those two for enc(4) in xform_ipip. */
729 tdbi->alg_auth = sav->alg_auth;
730 tdbi->alg_enc = sav->alg_enc;
731
732 m_tag_prepend(m, mtag);
733 } else {
734 if (mt != NULL)
735 mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
736 /* XXX do we need to mark m_flags??? */
737 }
738
739 key_sa_recordxfer(sav, m);
740
741 #ifdef DEV_ENC
742 encif->if_ipackets++;
743 encif->if_ibytes += m->m_pkthdr.len;
744
745 /*
746 * Pass the mbuf to enc0 for bpf and pfil. We will filter the IPIP
747 * packet later after it has been decapsulated.
748 */
749 ipsec_bpf(m, sav, AF_INET6, ENC_IN|ENC_BEFORE);
750
751 /* XXX-BZ does not make sense. */
752 if (prot != IPPROTO_IPIP)
753 if ((error = ipsec_filter(&m, PFIL_IN, ENC_IN|ENC_BEFORE)) != 0)
754 return (error);
755 #endif
756
757 /* Retrieve new protocol */
758 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
759
760 /*
761 * See the end of ip6_input for this logic.
762 * IPPROTO_IPV[46] case will be processed just like other ones
763 */
764 nest = 0;
765 nxt = nxt8;
766 while (nxt != IPPROTO_DONE) {
767 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
768 V_ip6stat.ip6s_toomanyhdr++;
769 error = EINVAL;
770 goto bad;
771 }
772
773 /*
774 * Protection against faulty packet - there should be
775 * more sanity checks in header chain processing.
776 */
777 if (m->m_pkthdr.len < skip) {
778 V_ip6stat.ip6s_tooshort++;
779 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
780 error = EINVAL;
781 goto bad;
782 }
783 /*
784 * Enforce IPsec policy checking if we are seeing last header.
785 * note that we do not visit this with protocols with pcb layer
786 * code - like udp/tcp/raw ip.
787 */
788 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
789 ipsec6_in_reject(m, NULL)) {
790 error = EINVAL;
791 goto bad;
792 }
793 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
794 }
795 return 0;
796 bad:
797 if (m)
798 m_freem(m);
799 return error;
800 }
801
802 void
803 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
804 {
805 struct ip6ctlparam *ip6cp = NULL;
806 struct mbuf *m = NULL;
807 struct ip6_hdr *ip6;
808 int off;
809
810 if (sa->sa_family != AF_INET6 ||
811 sa->sa_len != sizeof(struct sockaddr_in6))
812 return;
813 if ((unsigned)cmd >= PRC_NCMDS)
814 return;
815
816 /* if the parameter is from icmp6, decode it. */
817 if (d != NULL) {
818 ip6cp = (struct ip6ctlparam *)d;
819 m = ip6cp->ip6c_m;
820 ip6 = ip6cp->ip6c_ip6;
821 off = ip6cp->ip6c_off;
822 } else {
823 m = NULL;
824 ip6 = NULL;
825 off = 0; /* calm gcc */
826 }
827
828 if (ip6 != NULL) {
829
830 struct ip6ctlparam ip6cp1;
831
832 /*
833 * Notify the error to all possible sockets via pfctlinput2.
834 * Since the upper layer information (such as protocol type,
835 * source and destination ports) is embedded in the encrypted
836 * data and might have been cut, we can't directly call
837 * an upper layer ctlinput function. However, the pcbnotify
838 * function will consider source and destination addresses
839 * as well as the flow info value, and may be able to find
840 * some PCB that should be notified.
841 * Although pfctlinput2 will call esp6_ctlinput(), there is
842 * no possibility of an infinite loop of function calls,
843 * because we don't pass the inner IPv6 header.
844 */
845 bzero(&ip6cp1, sizeof(ip6cp1));
846 ip6cp1.ip6c_src = ip6cp->ip6c_src;
847 pfctlinput2(cmd, sa, (void *)&ip6cp1);
848
849 /*
850 * Then go to special cases that need ESP header information.
851 * XXX: We assume that when ip6 is non NULL,
852 * M and OFF are valid.
853 */
854
855 if (cmd == PRC_MSGSIZE) {
856 struct secasvar *sav;
857 u_int32_t spi;
858 int valid;
859
860 /* check header length before using m_copydata */
861 if (m->m_pkthdr.len < off + sizeof (struct esp))
862 return;
863 m_copydata(m, off + offsetof(struct esp, esp_spi),
864 sizeof(u_int32_t), (caddr_t) &spi);
865 /*
866 * Check to see if we have a valid SA corresponding to
867 * the address in the ICMP message payload.
868 */
869 sav = KEY_ALLOCSA((union sockaddr_union *)sa,
870 IPPROTO_ESP, spi);
871 valid = (sav != NULL);
872 if (sav)
873 KEY_FREESAV(&sav);
874
875 /* XXX Further validation? */
876
877 /*
878 * Depending on whether the SA is "valid" and
879 * routing table size (mtudisc_{hi,lo}wat), we will:
880 * - recalcurate the new MTU and create the
881 * corresponding routing entry, or
882 * - ignore the MTU change notification.
883 */
884 icmp6_mtudisc_update(ip6cp, valid);
885 }
886 } else {
887 /* we normally notify any pcb here */
888 }
889 }
890 #endif /* INET6 */
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