1 | /* $NetBSD: ipsec_input.c,v 1.36 2016/06/10 13:31:44 ozaki-r Exp $ */ |
2 | /* $FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/netipsec/ipsec_input.c,v 1.2.4.2 2003/03/28 20:32:53 sam Exp $ */ |
3 | /* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt Exp $ */ |
4 | |
5 | /* |
6 | * The authors of this code are John Ioannidis (ji@tla.org), |
7 | * Angelos D. Keromytis (kermit@csd.uch.gr) and |
8 | * Niels Provos (provos@physnet.uni-hamburg.de). |
9 | * |
10 | * This code was written by John Ioannidis for BSD/OS in Athens, Greece, |
11 | * in November 1995. |
12 | * |
13 | * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, |
14 | * by Angelos D. Keromytis. |
15 | * |
16 | * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis |
17 | * and Niels Provos. |
18 | * |
19 | * Additional features in 1999 by Angelos D. Keromytis. |
20 | * |
21 | * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, |
22 | * Angelos D. Keromytis and Niels Provos. |
23 | * Copyright (c) 2001, Angelos D. Keromytis. |
24 | * |
25 | * Permission to use, copy, and modify this software with or without fee |
26 | * is hereby granted, provided that this entire notice is included in |
27 | * all copies of any software which is or includes a copy or |
28 | * modification of this software. |
29 | * You may use this code under the GNU public license if you so wish. Please |
30 | * contribute changes back to the authors under this freer than GPL license |
31 | * so that we may further the use of strong encryption without limitations to |
32 | * all. |
33 | * |
34 | * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR |
35 | * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY |
36 | * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE |
37 | * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR |
38 | * PURPOSE. |
39 | */ |
40 | |
41 | #include <sys/cdefs.h> |
42 | __KERNEL_RCSID(0, "$NetBSD: ipsec_input.c,v 1.36 2016/06/10 13:31:44 ozaki-r Exp $" ); |
43 | |
44 | /* |
45 | * IPsec input processing. |
46 | */ |
47 | |
48 | #include "opt_inet.h" |
49 | #ifdef __FreeBSD__ |
50 | #include "opt_inet6.h" |
51 | #endif |
52 | |
53 | #include <sys/param.h> |
54 | #include <sys/systm.h> |
55 | #include <sys/malloc.h> |
56 | #include <sys/mbuf.h> |
57 | #include <sys/domain.h> |
58 | #include <sys/protosw.h> |
59 | #include <sys/socket.h> |
60 | #include <sys/errno.h> |
61 | #include <sys/syslog.h> |
62 | |
63 | #include <net/if.h> |
64 | #include <net/route.h> |
65 | |
66 | #include <netinet/in.h> |
67 | #include <netinet/in_systm.h> |
68 | #include <netinet/ip.h> |
69 | #include <netinet/ip_var.h> |
70 | #include <netinet/in_var.h> |
71 | #include <netinet/in_proto.h> |
72 | |
73 | #include <netinet/ip6.h> |
74 | #ifdef INET6 |
75 | #include <netinet6/ip6_var.h> |
76 | #include <netinet6/ip6_private.h> |
77 | #include <netinet6/scope6_var.h> |
78 | #endif |
79 | #include <netinet/in_pcb.h> |
80 | #ifdef INET6 |
81 | #include <netinet/icmp6.h> |
82 | #endif |
83 | |
84 | #include <netipsec/ipsec.h> |
85 | #include <netipsec/ipsec_private.h> |
86 | #ifdef INET6 |
87 | #include <netipsec/ipsec6.h> |
88 | #endif |
89 | #include <netipsec/ah_var.h> |
90 | #include <netipsec/esp.h> |
91 | #include <netipsec/esp_var.h> |
92 | #include <netipsec/ipcomp_var.h> |
93 | |
94 | #include <netipsec/key.h> |
95 | #include <netipsec/keydb.h> |
96 | |
97 | #include <netipsec/xform.h> |
98 | #include <netinet6/ip6protosw.h> |
99 | |
100 | #include <netipsec/ipsec_osdep.h> |
101 | |
102 | #include <net/net_osdep.h> |
103 | |
104 | #define IPSEC_ISTAT(p, x, y, z) \ |
105 | do { \ |
106 | switch (p) { \ |
107 | case IPPROTO_ESP: \ |
108 | ESP_STATINC(x); \ |
109 | break; \ |
110 | case IPPROTO_AH: \ |
111 | AH_STATINC(y); \ |
112 | break; \ |
113 | default: \ |
114 | IPCOMP_STATINC(z); \ |
115 | break; \ |
116 | } \ |
117 | } while (/*CONSTCOND*/0) |
118 | |
119 | /* |
120 | * ipsec_common_input gets called when an IPsec-protected packet |
121 | * is received by IPv4 or IPv6. It's job is to find the right SA |
122 | # and call the appropriate transform. The transform callback |
123 | * takes care of further processing (like ingress filtering). |
124 | */ |
125 | static int |
126 | ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto) |
127 | { |
128 | union sockaddr_union dst_address; |
129 | struct secasvar *sav; |
130 | u_int32_t spi; |
131 | u_int16_t sport; |
132 | u_int16_t dport; |
133 | int s, error; |
134 | |
135 | IPSEC_ISTAT(sproto, ESP_STAT_INPUT, AH_STAT_INPUT, |
136 | IPCOMP_STAT_INPUT); |
137 | |
138 | IPSEC_ASSERT(m != NULL, ("ipsec_common_input: null packet" )); |
139 | |
140 | if ((sproto == IPPROTO_ESP && !esp_enable) || |
141 | (sproto == IPPROTO_AH && !ah_enable) || |
142 | (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { |
143 | m_freem(m); |
144 | IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, AH_STAT_PDROPS, |
145 | IPCOMP_STAT_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, ESP_STAT_HDROPS, AH_STAT_HDROPS, |
152 | IPCOMP_STAT_HDROPS); |
153 | DPRINTF(("ipsec_common_input: packet too small\n" )); |
154 | return EINVAL; |
155 | } |
156 | |
157 | /* Retrieve the SPI from the relevant IPsec header */ |
158 | if (sproto == IPPROTO_ESP) |
159 | m_copydata(m, skip, sizeof(u_int32_t), &spi); |
160 | else if (sproto == IPPROTO_AH) |
161 | m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_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), &cpi); |
165 | spi = ntohl(htons(cpi)); |
166 | } else { |
167 | panic("ipsec_common_input called with bad protocol number :" |
168 | "%d\n" , sproto); |
169 | } |
170 | |
171 | |
172 | /* find the source port for NAT-T */ |
173 | nat_t_ports_get(m, &dport, &sport); |
174 | |
175 | /* |
176 | * Find the SA and (indirectly) call the appropriate |
177 | * kernel crypto routine. The resulting mbuf chain is a valid |
178 | * IP packet ready to go through input processing. |
179 | */ |
180 | memset(&dst_address, 0, sizeof (dst_address)); |
181 | dst_address.sa.sa_family = af; |
182 | switch (af) { |
183 | #ifdef INET |
184 | case AF_INET: |
185 | dst_address.sin.sin_len = sizeof(struct sockaddr_in); |
186 | m_copydata(m, offsetof(struct ip, ip_dst), |
187 | sizeof(struct in_addr), |
188 | &dst_address.sin.sin_addr); |
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 | &dst_address.sin6.sin6_addr); |
197 | if (sa6_recoverscope(&dst_address.sin6)) { |
198 | m_freem(m); |
199 | return EINVAL; |
200 | } |
201 | break; |
202 | #endif /* INET6 */ |
203 | default: |
204 | DPRINTF(("ipsec_common_input: unsupported protocol " |
205 | "family %u\n" , af)); |
206 | m_freem(m); |
207 | IPSEC_ISTAT(sproto, ESP_STAT_NOPF, AH_STAT_NOPF, |
208 | IPCOMP_STAT_NOPF); |
209 | return EPFNOSUPPORT; |
210 | } |
211 | |
212 | s = splsoftnet(); |
213 | |
214 | /* NB: only pass dst since key_allocsa follows RFC2401 */ |
215 | sav = KEY_ALLOCSA(&dst_address, sproto, spi, sport, dport); |
216 | if (sav == NULL) { |
217 | DPRINTF(("ipsec_common_input: no key association found for" |
218 | " SA %s/%08lx/%u/%u\n" , |
219 | ipsec_address(&dst_address), |
220 | (u_long) ntohl(spi), sproto, ntohs(dport))); |
221 | IPSEC_ISTAT(sproto, ESP_STAT_NOTDB, AH_STAT_NOTDB, |
222 | IPCOMP_STAT_NOTDB); |
223 | splx(s); |
224 | m_freem(m); |
225 | return ENOENT; |
226 | } |
227 | |
228 | if (sav->tdb_xform == NULL) { |
229 | DPRINTF(("ipsec_common_input: attempted to use uninitialized" |
230 | " SA %s/%08lx/%u\n" , |
231 | ipsec_address(&dst_address), |
232 | (u_long) ntohl(spi), sproto)); |
233 | IPSEC_ISTAT(sproto, ESP_STAT_NOXFORM, AH_STAT_NOXFORM, |
234 | IPCOMP_STAT_NOXFORM); |
235 | KEY_FREESAV(&sav); |
236 | splx(s); |
237 | m_freem(m); |
238 | return ENXIO; |
239 | } |
240 | |
241 | /* |
242 | * Call appropriate transform and return -- callback takes care of |
243 | * everything else. |
244 | */ |
245 | error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff); |
246 | KEY_FREESAV(&sav); |
247 | splx(s); |
248 | return error; |
249 | } |
250 | |
251 | #ifdef INET |
252 | /* |
253 | * Common input handler for IPv4 AH, ESP, and IPCOMP. |
254 | */ |
255 | void |
256 | ipsec4_common_input(struct mbuf *m, ...) |
257 | { |
258 | va_list ap; |
259 | int off, nxt; |
260 | |
261 | va_start(ap, m); |
262 | off = va_arg(ap, int); |
263 | nxt = va_arg(ap, int); |
264 | va_end(ap); |
265 | |
266 | (void) ipsec_common_input(m, off, offsetof(struct ip, ip_p), |
267 | AF_INET, nxt); |
268 | } |
269 | |
270 | /* |
271 | * IPsec input callback for INET protocols. |
272 | * This routine is called as the transform callback. |
273 | * Takes care of filtering and other sanity checks on |
274 | * the processed packet. |
275 | */ |
276 | int |
277 | ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav, |
278 | int skip, int protoff, struct m_tag *mt) |
279 | { |
280 | int prot, af __diagused, sproto; |
281 | struct ip *ip; |
282 | struct m_tag *mtag; |
283 | struct tdb_ident *tdbi; |
284 | struct secasindex *saidx; |
285 | int error; |
286 | |
287 | IPSEC_SPLASSERT_SOFTNET("ipsec4_common_input_cb" ); |
288 | |
289 | IPSEC_ASSERT(m != NULL, ("ipsec4_common_input_cb: null mbuf" )); |
290 | IPSEC_ASSERT(sav != NULL, ("ipsec4_common_input_cb: null SA" )); |
291 | IPSEC_ASSERT(sav->sah != NULL, ("ipsec4_common_input_cb: null SAH" )); |
292 | saidx = &sav->sah->saidx; |
293 | af = saidx->dst.sa.sa_family; |
294 | IPSEC_ASSERT(af == AF_INET, ("ipsec4_common_input_cb: unexpected af %u" ,af)); |
295 | sproto = saidx->proto; |
296 | IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || |
297 | sproto == IPPROTO_IPCOMP, |
298 | ("ipsec4_common_input_cb: unexpected security protocol %u" , |
299 | sproto)); |
300 | |
301 | /* Sanity check */ |
302 | if (m == NULL) { |
303 | DPRINTF(("ipsec4_common_input_cb: null mbuf" )); |
304 | IPSEC_ISTAT(sproto, ESP_STAT_BADKCR, AH_STAT_BADKCR, |
305 | IPCOMP_STAT_BADKCR); |
306 | KEY_FREESAV(&sav); |
307 | return EINVAL; |
308 | } |
309 | |
310 | /* Fix IPv4 header */ |
311 | if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) { |
312 | DPRINTF(("ipsec4_common_input_cb: processing failed " |
313 | "for SA %s/%08lx\n" , |
314 | ipsec_address(&sav->sah->saidx.dst), |
315 | (u_long) ntohl(sav->spi))); |
316 | IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, |
317 | IPCOMP_STAT_HDROPS); |
318 | error = ENOBUFS; |
319 | goto bad; |
320 | } |
321 | |
322 | ip = mtod(m, struct ip *); |
323 | ip->ip_len = htons(m->m_pkthdr.len); |
324 | prot = ip->ip_p; |
325 | |
326 | /* IP-in-IP encapsulation */ |
327 | if (prot == IPPROTO_IPIP) { |
328 | struct ip ipn; |
329 | |
330 | /* ipn will now contain the inner IPv4 header */ |
331 | m_copydata(m, ip->ip_hl << 2, sizeof(struct ip), &ipn); |
332 | |
333 | #ifdef notyet |
334 | /* XXX PROXY address isn't recorded in SAH */ |
335 | /* |
336 | * Check that the inner source address is the same as |
337 | * the proxy address, if available. |
338 | */ |
339 | if ((saidx->proxy.sa.sa_family == AF_INET && |
340 | saidx->proxy.sin.sin_addr.s_addr != |
341 | INADDR_ANY && |
342 | ipn.ip_src.s_addr != |
343 | saidx->proxy.sin.sin_addr.s_addr) || |
344 | (saidx->proxy.sa.sa_family != AF_INET && |
345 | saidx->proxy.sa.sa_family != 0)) { |
346 | |
347 | DPRINTF(("ipsec4_common_input_cb: inner " |
348 | "source address %s doesn't correspond to " |
349 | "expected proxy source %s, SA %s/%08lx\n" , |
350 | inet_ntoa4(ipn.ip_src), |
351 | ipsp_address(saidx->proxy), |
352 | ipsp_address(saidx->dst), |
353 | (u_long) ntohl(sav->spi))); |
354 | |
355 | IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, |
356 | AH_STAT_PDROPS, |
357 | IPCOMP_STAT_PDROPS); |
358 | error = EACCES; |
359 | goto bad; |
360 | } |
361 | #endif /*XXX*/ |
362 | } |
363 | #if INET6 |
364 | /* IPv6-in-IP encapsulation. */ |
365 | if (prot == IPPROTO_IPV6) { |
366 | struct ip6_hdr ip6n; |
367 | |
368 | /* ip6n will now contain the inner IPv6 header. */ |
369 | m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr), &ip6n); |
370 | |
371 | #ifdef notyet |
372 | /* |
373 | * Check that the inner source address is the same as |
374 | * the proxy address, if available. |
375 | */ |
376 | if ((saidx->proxy.sa.sa_family == AF_INET6 && |
377 | !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && |
378 | !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, |
379 | &saidx->proxy.sin6.sin6_addr)) || |
380 | (saidx->proxy.sa.sa_family != AF_INET6 && |
381 | saidx->proxy.sa.sa_family != 0)) { |
382 | |
383 | DPRINTF(("ipsec4_common_input_cb: inner " |
384 | "source address %s doesn't correspond to " |
385 | "expected proxy source %s, SA %s/%08lx\n" , |
386 | ip6_sprintf(&ip6n.ip6_src), |
387 | ipsec_address(&saidx->proxy), |
388 | ipsec_address(&saidx->dst), |
389 | (u_long) ntohl(sav->spi))); |
390 | |
391 | IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, |
392 | AH_STAT_PDROPS, |
393 | IPCOMP_STAT_PDROPS); |
394 | error = EACCES; |
395 | goto bad; |
396 | } |
397 | #endif /*XXX*/ |
398 | } |
399 | #endif /* INET6 */ |
400 | |
401 | /* |
402 | * Record what we've done to the packet (under what SA it was |
403 | * processed). If we've been passed an mtag, it means the packet |
404 | * was already processed by an ethernet/crypto combo card and |
405 | * thus has a tag attached with all the right information, but |
406 | * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to |
407 | * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. |
408 | */ |
409 | if (mt == NULL && sproto != IPPROTO_IPCOMP) { |
410 | mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, |
411 | sizeof(struct tdb_ident), M_NOWAIT); |
412 | if (mtag == NULL) { |
413 | DPRINTF(("ipsec4_common_input_cb: failed to get tag\n" )); |
414 | IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, |
415 | AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); |
416 | error = ENOMEM; |
417 | goto bad; |
418 | } |
419 | |
420 | tdbi = (struct tdb_ident *)(mtag + 1); |
421 | memcpy(&tdbi->dst, &saidx->dst, saidx->dst.sa.sa_len); |
422 | tdbi->proto = sproto; |
423 | tdbi->spi = sav->spi; |
424 | |
425 | m_tag_prepend(m, mtag); |
426 | } else { |
427 | if (mt != NULL) |
428 | mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; |
429 | /* XXX do we need to mark m_flags??? */ |
430 | } |
431 | |
432 | key_sa_recordxfer(sav, m); /* record data transfer */ |
433 | |
434 | if ((inetsw[ip_protox[prot]].pr_flags & PR_LASTHDR) != 0 && |
435 | ipsec4_in_reject(m, NULL)) { |
436 | error = EINVAL; |
437 | goto bad; |
438 | } |
439 | (*inetsw[ip_protox[prot]].pr_input)(m, skip, prot); |
440 | return 0; |
441 | bad: |
442 | m_freem(m); |
443 | return error; |
444 | } |
445 | #endif /* INET */ |
446 | |
447 | #ifdef INET6 |
448 | /* IPv6 AH wrapper. */ |
449 | int |
450 | ipsec6_common_input(struct mbuf **mp, int *offp, int proto) |
451 | { |
452 | int l = 0; |
453 | int protoff, nxt; |
454 | struct ip6_ext ip6e; |
455 | |
456 | if (*offp < sizeof(struct ip6_hdr)) { |
457 | DPRINTF(("ipsec6_common_input: bad offset %u\n" , *offp)); |
458 | IPSEC_ISTAT(proto, ESP_STAT_HDROPS, AH_STAT_HDROPS, |
459 | IPCOMP_STAT_HDROPS); |
460 | m_freem(*mp); |
461 | return IPPROTO_DONE; |
462 | } else if (*offp == sizeof(struct ip6_hdr)) { |
463 | protoff = offsetof(struct ip6_hdr, ip6_nxt); |
464 | } else { |
465 | /* Chase down the header chain... */ |
466 | protoff = sizeof(struct ip6_hdr); |
467 | nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; |
468 | |
469 | do { |
470 | protoff += l; |
471 | m_copydata(*mp, protoff, sizeof(ip6e), &ip6e); |
472 | |
473 | if (nxt == IPPROTO_AH) |
474 | l = (ip6e.ip6e_len + 2) << 2; |
475 | else |
476 | l = (ip6e.ip6e_len + 1) << 3; |
477 | IPSEC_ASSERT(l > 0, |
478 | ("ipsec6_common_input: l went zero or negative" )); |
479 | |
480 | nxt = ip6e.ip6e_nxt; |
481 | } while (protoff + l < *offp); |
482 | |
483 | /* Malformed packet check */ |
484 | if (protoff + l != *offp) { |
485 | DPRINTF(("ipsec6_common_input: bad packet header chain, " |
486 | "protoff %u, l %u, off %u\n" , protoff, l, *offp)); |
487 | IPSEC_ISTAT(proto, ESP_STAT_HDROPS, |
488 | AH_STAT_HDROPS, |
489 | IPCOMP_STAT_HDROPS); |
490 | m_freem(*mp); |
491 | *mp = NULL; |
492 | return IPPROTO_DONE; |
493 | } |
494 | protoff += offsetof(struct ip6_ext, ip6e_nxt); |
495 | } |
496 | (void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto); |
497 | return IPPROTO_DONE; |
498 | } |
499 | |
500 | /* |
501 | * NB: ipsec_netbsd.c has a duplicate definition of esp6_ctlinput(), |
502 | * with slightly ore recent multicast tests. These should be merged. |
503 | * For now, ifdef accordingly. |
504 | */ |
505 | #ifdef __FreeBSD__ |
506 | void |
507 | esp6_ctlinput(int cmd, struct sockaddr *sa, void *d) |
508 | { |
509 | if (sa->sa_family != AF_INET6 || |
510 | sa->sa_len != sizeof(struct sockaddr_in6)) |
511 | return; |
512 | if ((unsigned)cmd >= PRC_NCMDS) |
513 | return; |
514 | |
515 | /* if the parameter is from icmp6, decode it. */ |
516 | if (d != NULL) { |
517 | struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; |
518 | struct mbuf *m = ip6cp->ip6c_m; |
519 | int off = ip6cp->ip6c_off; |
520 | |
521 | struct ip6ctlparam ip6cp1; |
522 | |
523 | /* |
524 | * Notify the error to all possible sockets via pfctlinput2. |
525 | * Since the upper layer information (such as protocol type, |
526 | * source and destination ports) is embedded in the encrypted |
527 | * data and might have been cut, we can't directly call |
528 | * an upper layer ctlinput function. However, the pcbnotify |
529 | * function will consider source and destination addresses |
530 | * as well as the flow info value, and may be able to find |
531 | * some PCB that should be notified. |
532 | * Although pfctlinput2 will call esp6_ctlinput(), there is |
533 | * no possibility of an infinite loop of function calls, |
534 | * because we don't pass the inner IPv6 header. |
535 | */ |
536 | memset(&ip6cp1, 0, sizeof(ip6cp1)); |
537 | ip6cp1.ip6c_src = ip6cp->ip6c_src; |
538 | pfctlinput2(cmd, sa, &ip6cp1); |
539 | |
540 | /* |
541 | * Then go to special cases that need ESP header information. |
542 | * XXX: We assume that when ip6 is non NULL, |
543 | * M and OFF are valid. |
544 | */ |
545 | |
546 | if (cmd == PRC_MSGSIZE) { |
547 | struct secasvar *sav; |
548 | u_int32_t spi; |
549 | int valid; |
550 | |
551 | /* check header length before using m_copydata */ |
552 | if (m->m_pkthdr.len < off + sizeof (struct esp)) |
553 | return; |
554 | m_copydata(m, off + offsetof(struct esp, esp_spi), |
555 | sizeof(u_int32_t), &spi); |
556 | /* |
557 | * Check to see if we have a valid SA corresponding to |
558 | * the address in the ICMP message payload. |
559 | */ |
560 | sav = KEY_ALLOCSA((union sockaddr_union *)sa, |
561 | IPPROTO_ESP, spi); |
562 | valid = (sav != NULL); |
563 | if (sav) |
564 | KEY_FREESAV(&sav); |
565 | |
566 | /* XXX Further validation? */ |
567 | |
568 | /* |
569 | * Depending on whether the SA is "valid" and |
570 | * routing table size (mtudisc_{hi,lo}wat), we will: |
571 | * - recalcurate the new MTU and create the |
572 | * corresponding routing entry, or |
573 | * - ignore the MTU change notification. |
574 | */ |
575 | icmp6_mtudisc_update(ip6cp, valid); |
576 | } |
577 | } else { |
578 | /* we normally notify any pcb here */ |
579 | } |
580 | } |
581 | #endif /* __FreeBSD__ */ |
582 | |
583 | extern const struct ip6protosw inet6sw[]; |
584 | extern u_char ip6_protox[]; |
585 | |
586 | /* |
587 | * IPsec input callback, called by the transform callback. Takes care of |
588 | * filtering and other sanity checks on the processed packet. |
589 | */ |
590 | int |
591 | ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff, |
592 | struct m_tag *mt) |
593 | { |
594 | int af __diagused, sproto; |
595 | struct ip6_hdr *ip6; |
596 | struct m_tag *mtag; |
597 | struct tdb_ident *tdbi; |
598 | struct secasindex *saidx; |
599 | int nxt; |
600 | u_int8_t prot, nxt8; |
601 | int error, nest; |
602 | |
603 | IPSEC_ASSERT(m != NULL, ("ipsec6_common_input_cb: null mbuf" )); |
604 | IPSEC_ASSERT(sav != NULL, ("ipsec6_common_input_cb: null SA" )); |
605 | IPSEC_ASSERT(sav->sah != NULL, ("ipsec6_common_input_cb: null SAH" )); |
606 | saidx = &sav->sah->saidx; |
607 | af = saidx->dst.sa.sa_family; |
608 | IPSEC_ASSERT(af == AF_INET6, |
609 | ("ipsec6_common_input_cb: unexpected af %u" , af)); |
610 | sproto = saidx->proto; |
611 | IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH || |
612 | sproto == IPPROTO_IPCOMP, |
613 | ("ipsec6_common_input_cb: unexpected security protocol %u" , |
614 | sproto)); |
615 | |
616 | /* Sanity check */ |
617 | if (m == NULL) { |
618 | DPRINTF(("ipsec6_common_input_cb: null mbuf" )); |
619 | IPSEC_ISTAT(sproto, ESP_STAT_BADKCR, AH_STAT_BADKCR, |
620 | IPCOMP_STAT_BADKCR); |
621 | error = EINVAL; |
622 | goto bad; |
623 | } |
624 | |
625 | /* Fix IPv6 header */ |
626 | if (m->m_len < sizeof(struct ip6_hdr) && |
627 | (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { |
628 | |
629 | DPRINTF(("ipsec6_common_input_cb: processing failed " |
630 | "for SA %s/%08lx\n" , ipsec_address(&sav->sah->saidx.dst), |
631 | (u_long) ntohl(sav->spi))); |
632 | |
633 | IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, AH_STAT_HDROPS, |
634 | IPCOMP_STAT_HDROPS); |
635 | error = EACCES; |
636 | goto bad; |
637 | } |
638 | |
639 | ip6 = mtod(m, struct ip6_hdr *); |
640 | ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); |
641 | |
642 | /* Save protocol */ |
643 | m_copydata(m, protoff, 1, &prot); |
644 | |
645 | #ifdef INET |
646 | /* IP-in-IP encapsulation */ |
647 | if (prot == IPPROTO_IPIP) { |
648 | struct ip ipn; |
649 | |
650 | /* ipn will now contain the inner IPv4 header */ |
651 | m_copydata(m, skip, sizeof(struct ip), &ipn); |
652 | |
653 | #ifdef notyet |
654 | /* |
655 | * Check that the inner source address is the same as |
656 | * the proxy address, if available. |
657 | */ |
658 | if ((saidx->proxy.sa.sa_family == AF_INET && |
659 | saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY && |
660 | ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) || |
661 | (saidx->proxy.sa.sa_family != AF_INET && |
662 | saidx->proxy.sa.sa_family != 0)) { |
663 | |
664 | DPRINTF(("ipsec6_common_input_cb: inner " |
665 | "source address %s doesn't correspond to " |
666 | "expected proxy source %s, SA %s/%08lx\n" , |
667 | inet_ntoa4(ipn.ip_src), |
668 | ipsec_address(&saidx->proxy), |
669 | ipsec_address(&saidx->dst), |
670 | (u_long) ntohl(sav->spi))); |
671 | |
672 | IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, |
673 | AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); |
674 | error = EACCES; |
675 | goto bad; |
676 | } |
677 | #endif /*XXX*/ |
678 | } |
679 | #endif /* INET */ |
680 | |
681 | /* IPv6-in-IP encapsulation */ |
682 | if (prot == IPPROTO_IPV6) { |
683 | struct ip6_hdr ip6n; |
684 | |
685 | /* ip6n will now contain the inner IPv6 header. */ |
686 | m_copydata(m, skip, sizeof(struct ip6_hdr), &ip6n); |
687 | |
688 | #ifdef notyet |
689 | /* |
690 | * Check that the inner source address is the same as |
691 | * the proxy address, if available. |
692 | */ |
693 | if ((saidx->proxy.sa.sa_family == AF_INET6 && |
694 | !IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) && |
695 | !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, |
696 | &saidx->proxy.sin6.sin6_addr)) || |
697 | (saidx->proxy.sa.sa_family != AF_INET6 && |
698 | saidx->proxy.sa.sa_family != 0)) { |
699 | |
700 | DPRINTF(("ipsec6_common_input_cb: inner " |
701 | "source address %s doesn't correspond to " |
702 | "expected proxy source %s, SA %s/%08lx\n" , |
703 | ip6_sprintf(&ip6n.ip6_src), |
704 | ipsec_address(&saidx->proxy), |
705 | ipsec_address(&saidx->dst), |
706 | (u_long) ntohl(sav->spi))); |
707 | |
708 | IPSEC_ISTAT(sproto, ESP_STAT_PDROPS, |
709 | AH_STAT_PDROPS, IPCOMP_STAT_PDROPS); |
710 | error = EACCES; |
711 | goto bad; |
712 | } |
713 | #endif /*XXX*/ |
714 | } |
715 | |
716 | /* |
717 | * Record what we've done to the packet (under what SA it was |
718 | * processed). If we've been passed an mtag, it means the packet |
719 | * was already processed by an ethernet/crypto combo card and |
720 | * thus has a tag attached with all the right information, but |
721 | * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to |
722 | * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. |
723 | */ |
724 | if (mt == NULL && sproto != IPPROTO_IPCOMP) { |
725 | mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, |
726 | sizeof(struct tdb_ident), M_NOWAIT); |
727 | if (mtag == NULL) { |
728 | DPRINTF(("ipsec_common_input_cb: failed to " |
729 | "get tag\n" )); |
730 | IPSEC_ISTAT(sproto, ESP_STAT_HDROPS, |
731 | AH_STAT_HDROPS, IPCOMP_STAT_HDROPS); |
732 | error = ENOMEM; |
733 | goto bad; |
734 | } |
735 | |
736 | tdbi = (struct tdb_ident *)(mtag + 1); |
737 | memcpy(&tdbi->dst, &saidx->dst, sizeof(union sockaddr_union)); |
738 | tdbi->proto = sproto; |
739 | tdbi->spi = sav->spi; |
740 | |
741 | m_tag_prepend(m, mtag); |
742 | } else { |
743 | if (mt != NULL) |
744 | mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; |
745 | /* XXX do we need to mark m_flags??? */ |
746 | } |
747 | |
748 | key_sa_recordxfer(sav, m); |
749 | |
750 | /* Retrieve new protocol */ |
751 | m_copydata(m, protoff, sizeof(u_int8_t), &nxt8); |
752 | |
753 | /* |
754 | * See the end of ip6_input for this logic. |
755 | * IPPROTO_IPV[46] case will be processed just like other ones |
756 | */ |
757 | nest = 0; |
758 | nxt = nxt8; |
759 | while (nxt != IPPROTO_DONE) { |
760 | if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { |
761 | IP6_STATINC(IP6_STAT_TOOMANYHDR); |
762 | error = EINVAL; |
763 | goto bad; |
764 | } |
765 | |
766 | /* |
767 | * Protection against faulty packet - there should be |
768 | * more sanity checks in header chain processing. |
769 | */ |
770 | if (m->m_pkthdr.len < skip) { |
771 | IP6_STATINC(IP6_STAT_TOOSHORT); |
772 | in6_ifstat_inc(m_get_rcvif_NOMPSAFE(m), |
773 | ifs6_in_truncated); |
774 | error = EINVAL; |
775 | goto bad; |
776 | } |
777 | /* |
778 | * Enforce IPsec policy checking if we are seeing last header. |
779 | * note that we do not visit this with protocols with pcb layer |
780 | * code - like udp/tcp/raw ip. |
781 | */ |
782 | if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && |
783 | ipsec6_in_reject(m, NULL)) { |
784 | error = EINVAL; |
785 | goto bad; |
786 | } |
787 | nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt); |
788 | } |
789 | return 0; |
790 | bad: |
791 | if (m) |
792 | m_freem(m); |
793 | return error; |
794 | } |
795 | #endif /* INET6 */ |
796 | |