1 /*
2 * Copyright (c) 2008-2016 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 /* $FreeBSD: src/sys/netinet6/esp_input.c,v 1.1.2.3 2001/07/03 11:01:50 ume Exp $ */
30 /* $KAME: esp_input.c,v 1.55 2001/03/23 08:08:47 itojun Exp $ */
31
32 /*
33 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 * 3. Neither the name of the project nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 */
60
61 #define _IP_VHL
62
63 /*
64 * RFC1827/2406 Encapsulated Security Payload.
65 */
66
67 #include <sys/param.h>
68 #include <sys/systm.h>
69 #include <sys/malloc.h>
70 #include <sys/mbuf.h>
71 #include <sys/mcache.h>
72 #include <sys/domain.h>
73 #include <sys/protosw.h>
74 #include <sys/socket.h>
75 #include <sys/errno.h>
76 #include <sys/time.h>
77 #include <sys/kernel.h>
78 #include <sys/syslog.h>
79
80 #include <net/if.h>
81 #include <net/if_ipsec.h>
82 #include <net/multi_layer_pkt_log.h>
83 #include <net/route.h>
84 #include <net/if_ports_used.h>
85 #include <kern/cpu_number.h>
86 #include <kern/locks.h>
87
88 #include <netinet/in.h>
89 #include <netinet/in_systm.h>
90 #include <netinet/ip.h>
91 #include <netinet/ip_var.h>
92 #include <netinet/in_var.h>
93 #include <netinet/ip_ecn.h>
94 #include <netinet/in_pcb.h>
95 #include <netinet/udp.h>
96 #include <netinet/tcp.h>
97 #include <netinet/in_tclass.h>
98 #include <netinet6/ip6_ecn.h>
99
100 #include <netinet/ip6.h>
101 #include <netinet6/in6_pcb.h>
102 #include <netinet6/ip6_var.h>
103 #include <netinet/icmp6.h>
104 #include <netinet6/ip6protosw.h>
105
106 #include <netinet6/ipsec.h>
107 #include <netinet6/ipsec6.h>
108 #include <netinet6/ah.h>
109 #include <netinet6/ah6.h>
110 #include <netinet6/esp.h>
111 #include <netinet6/esp6.h>
112 #include <netkey/key.h>
113 #include <netkey/keydb.h>
114 #include <netkey/key_debug.h>
115
116 #include <net/kpi_protocol.h>
117 #include <netinet/kpi_ipfilter_var.h>
118
119 #include <net/net_osdep.h>
120 #include <mach/sdt.h>
121 #include <corecrypto/cc.h>
122
123 #include <sys/kdebug.h>
124 #define DBG_LAYER_BEG NETDBG_CODE(DBG_NETIPSEC, 1)
125 #define DBG_LAYER_END NETDBG_CODE(DBG_NETIPSEC, 3)
126 #define DBG_FNC_ESPIN NETDBG_CODE(DBG_NETIPSEC, (6 << 8))
127 #define DBG_FNC_DECRYPT NETDBG_CODE(DBG_NETIPSEC, (7 << 8))
128 #define IPLEN_FLIPPED
129
130 #define ESPMAXLEN \
131 (sizeof(struct esp) < sizeof(struct newesp) \
132 ? sizeof(struct newesp) : sizeof(struct esp))
133
134 static struct ip *
esp4_input_strip_udp_encap(struct mbuf * m,int iphlen)135 esp4_input_strip_udp_encap(struct mbuf *m, int iphlen)
136 {
137 // strip the udp header that's encapsulating ESP
138 struct ip *ip;
139 u_int8_t stripsiz = (u_int8_t)sizeof(struct udphdr);
140
141 ip = mtod(m, __typeof__(ip));
142 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), iphlen);
143 m->m_data += stripsiz;
144 m->m_len -= stripsiz;
145 m->m_pkthdr.len -= stripsiz;
146 ip = mtod(m, __typeof__(ip));
147 ip->ip_len = ip->ip_len - stripsiz;
148 ip->ip_p = IPPROTO_ESP;
149 return ip;
150 }
151
152 static struct ip6_hdr *
esp6_input_strip_udp_encap(struct mbuf * m,int ip6hlen)153 esp6_input_strip_udp_encap(struct mbuf *m, int ip6hlen)
154 {
155 // strip the udp header that's encapsulating ESP
156 struct ip6_hdr *ip6;
157 u_int8_t stripsiz = (u_int8_t)sizeof(struct udphdr);
158
159 ip6 = mtod(m, __typeof__(ip6));
160 ovbcopy((caddr_t)ip6, (caddr_t)(((u_char *)ip6) + stripsiz), ip6hlen);
161 m->m_data += stripsiz;
162 m->m_len -= stripsiz;
163 m->m_pkthdr.len -= stripsiz;
164 ip6 = mtod(m, __typeof__(ip6));
165 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
166 ip6->ip6_nxt = IPPROTO_ESP;
167 return ip6;
168 }
169
170 static void
esp_input_log(struct mbuf * m,struct secasvar * sav,u_int32_t spi,u_int32_t seq)171 esp_input_log(struct mbuf *m, struct secasvar *sav, u_int32_t spi, u_int32_t seq)
172 {
173 if (net_mpklog_enabled &&
174 (sav->sah->ipsec_if->if_xflags & IFXF_MPK_LOG) == IFXF_MPK_LOG) {
175 struct tcphdr th = {};
176 u_int32_t proto_len = 0;
177 u_int8_t iphlen = 0;
178 u_int8_t proto = 0;
179
180 struct ip *inner_ip = mtod(m, struct ip *);
181 if (IP_VHL_V(inner_ip->ip_vhl) == 4) {
182 iphlen = (u_int8_t)(IP_VHL_HL(inner_ip->ip_vhl) << 2);
183 proto = inner_ip->ip_p;
184 } else if (IP_VHL_V(inner_ip->ip_vhl) == 6) {
185 struct ip6_hdr *inner_ip6 = mtod(m, struct ip6_hdr *);
186 iphlen = sizeof(struct ip6_hdr);
187 proto = inner_ip6->ip6_nxt;
188 }
189
190 if (proto == IPPROTO_TCP) {
191 if ((int)(iphlen + sizeof(th)) <= m->m_pkthdr.len) {
192 m_copydata(m, iphlen, sizeof(th), (u_int8_t *)&th);
193 }
194
195 proto_len = m->m_pkthdr.len - iphlen - (th.th_off << 2);
196 MPKL_ESP_INPUT_TCP(esp_mpkl_log_object,
197 ntohl(spi), seq,
198 ntohs(th.th_sport), ntohs(th.th_dport),
199 ntohl(th.th_seq), proto_len);
200 }
201 }
202 }
203
204 void
esp4_input(struct mbuf * m,int off)205 esp4_input(struct mbuf *m, int off)
206 {
207 (void)esp4_input_extended(m, off, NULL);
208 }
209
210 struct mbuf *
esp4_input_extended(struct mbuf * m,int off,ifnet_t interface)211 esp4_input_extended(struct mbuf *m, int off, ifnet_t interface)
212 {
213 struct ip *ip;
214 struct ip6_hdr *ip6;
215 struct esp *esp;
216 struct esptail esptail;
217 u_int32_t spi;
218 u_int32_t seq;
219 struct secasvar *sav = NULL;
220 size_t taillen;
221 u_int16_t nxt;
222 const struct esp_algorithm *algo;
223 int ivlen;
224 size_t esplen;
225 u_int8_t hlen;
226 sa_family_t ifamily;
227 struct mbuf *out_m = NULL;
228 mbuf_traffic_class_t traffic_class = 0;
229
230 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_START, 0, 0, 0, 0, 0);
231 /* sanity check for alignment. */
232 if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
233 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
234 "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
235 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
236 goto bad;
237 }
238
239 if (m->m_len < off + ESPMAXLEN) {
240 m = m_pullup(m, off + ESPMAXLEN);
241 if (!m) {
242 ipseclog((LOG_DEBUG,
243 "IPv4 ESP input: can't pullup in esp4_input\n"));
244 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
245 goto bad;
246 }
247 }
248
249 m->m_pkthdr.csum_flags &= ~CSUM_RX_FLAGS;
250
251 /* Expect 32-bit aligned data pointer on strict-align platforms */
252 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
253
254 ip = mtod(m, struct ip *);
255 // expect udp-encap and esp packets only
256 if (ip->ip_p != IPPROTO_ESP &&
257 !(ip->ip_p == IPPROTO_UDP && off >= sizeof(struct udphdr))) {
258 ipseclog((LOG_DEBUG,
259 "IPv4 ESP input: invalid protocol type\n"));
260 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
261 goto bad;
262 }
263 esp = (struct esp *)(void *)(((u_int8_t *)ip) + off);
264 #ifdef _IP_VHL
265 hlen = (u_int8_t)(IP_VHL_HL(ip->ip_vhl) << 2);
266 #else
267 hlen = ip->ip_hl << 2;
268 #endif
269
270 /* find the sassoc. */
271 spi = esp->esp_spi;
272
273 if ((sav = key_allocsa_extended(AF_INET,
274 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, IFSCOPE_NONE,
275 IPPROTO_ESP, spi, interface)) == 0) {
276 ipseclog((LOG_WARNING,
277 "IPv4 ESP input: no key association found for spi %u (0x%08x)\n",
278 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
279 IPSEC_STAT_INCREMENT(ipsecstat.in_nosa);
280 goto bad;
281 }
282 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
283 printf("DP esp4_input called to allocate SA:0x%llx\n",
284 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
285 if (sav->state != SADB_SASTATE_MATURE
286 && sav->state != SADB_SASTATE_DYING) {
287 ipseclog((LOG_DEBUG,
288 "IPv4 ESP input: non-mature/dying SA found for spi %u (0x%08x)\n",
289 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
290 IPSEC_STAT_INCREMENT(ipsecstat.in_badspi);
291 goto bad;
292 }
293 algo = esp_algorithm_lookup(sav->alg_enc);
294 if (!algo) {
295 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
296 "unsupported encryption algorithm for spi %u (0x%08x)\n",
297 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
298 IPSEC_STAT_INCREMENT(ipsecstat.in_badspi);
299 goto bad;
300 }
301
302 /* check if we have proper ivlen information */
303 ivlen = sav->ivlen;
304 if (ivlen < 0) {
305 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
306 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
307 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
308 goto bad;
309 }
310
311 seq = ntohl(((struct newesp *)esp)->esp_seq);
312
313 if ((sav->flags2 & SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) ==
314 SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) {
315 u_int8_t dscp = ip->ip_tos >> IPTOS_DSCP_SHIFT;
316 traffic_class = rfc4594_dscp_to_tc(dscp);
317 }
318
319 if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL &&
320 ((sav->alg_auth && sav->key_auth) || algo->finalizedecrypt))) {
321 goto noreplaycheck;
322 }
323
324 if ((sav->alg_auth == SADB_X_AALG_NULL || sav->alg_auth == SADB_AALG_NONE) &&
325 !algo->finalizedecrypt) {
326 goto noreplaycheck;
327 }
328
329 /*
330 * check for sequence number.
331 */
332 _CASSERT(MBUF_TC_MAX <= UINT8_MAX);
333 if (ipsec_chkreplay(seq, sav, (u_int8_t)traffic_class)) {
334 ; /*okey*/
335 } else {
336 IPSEC_STAT_INCREMENT(ipsecstat.in_espreplay);
337 ipseclog((LOG_WARNING,
338 "replay packet in IPv4 ESP input: seq(%u) tc(%u) %s %s\n",
339 seq, (u_int8_t)traffic_class, ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
340 goto bad;
341 }
342
343 /* Save ICV from packet for verification later */
344 size_t siz = 0;
345 unsigned char saved_icv[AH_MAXSUMSIZE] __attribute__((aligned(4)));
346 if (algo->finalizedecrypt) {
347 siz = algo->icvlen;
348 VERIFY(siz <= USHRT_MAX);
349 m_copydata(m, m->m_pkthdr.len - (u_short)siz, (u_short)siz, (caddr_t) saved_icv);
350 } else {
351 /* check ICV immediately */
352 u_char sum0[AH_MAXSUMSIZE] __attribute__((aligned(4)));
353 u_char sum[AH_MAXSUMSIZE] __attribute__((aligned(4)));
354 const struct ah_algorithm *sumalgo;
355
356 sumalgo = ah_algorithm_lookup(sav->alg_auth);
357 if (!sumalgo) {
358 goto noreplaycheck;
359 }
360 siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
361 if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
362 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
363 goto bad;
364 }
365 if (AH_MAXSUMSIZE < siz) {
366 ipseclog((LOG_DEBUG,
367 "internal error: AH_MAXSUMSIZE must be larger than %u\n",
368 (u_int32_t)siz));
369 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
370 goto bad;
371 }
372
373 m_copydata(m, m->m_pkthdr.len - (int)siz, (int)siz, (caddr_t) &sum0[0]);
374
375 if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
376 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
377 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
378 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthfail);
379 goto bad;
380 }
381
382 if (cc_cmp_safe(siz, sum0, sum)) {
383 ipseclog((LOG_WARNING, "cc_cmp fail in IPv4 ESP input: %s %s\n",
384 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
385 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthfail);
386 goto bad;
387 }
388
389 m->m_flags |= M_AUTHIPDGM;
390 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthsucc);
391
392 /*
393 * update replay window.
394 */
395 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL) {
396 if (ipsec_updatereplay(seq, sav, (u_int8_t)traffic_class)) {
397 IPSEC_STAT_INCREMENT(ipsecstat.in_espreplay);
398 goto bad;
399 }
400 }
401 }
402
403
404 /* strip off the authentication data */
405 m_adj(m, (int)-siz);
406 ip = mtod(m, struct ip *);
407 #ifdef IPLEN_FLIPPED
408 ip->ip_len = ip->ip_len - (u_short)siz;
409 #else
410 ip->ip_len = htons(ntohs(ip->ip_len) - siz);
411 #endif
412
413 noreplaycheck:
414
415 /* process main esp header. */
416 if (sav->flags & SADB_X_EXT_OLD) {
417 /* RFC 1827 */
418 esplen = sizeof(struct esp);
419 } else {
420 /* RFC 2406 */
421 if (sav->flags & SADB_X_EXT_DERIV) {
422 esplen = sizeof(struct esp);
423 } else {
424 esplen = sizeof(struct newesp);
425 }
426 }
427
428 if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
429 ipseclog((LOG_WARNING,
430 "IPv4 ESP input: packet too short\n"));
431 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
432 goto bad;
433 }
434
435 if (m->m_len < off + esplen + ivlen) {
436 m = m_pullup(m, (int)(off + esplen + ivlen));
437 if (!m) {
438 ipseclog((LOG_DEBUG,
439 "IPv4 ESP input: can't pullup in esp4_input\n"));
440 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
441 goto bad;
442 }
443 }
444
445 /*
446 * pre-compute and cache intermediate key
447 */
448 if (esp_schedule(algo, sav) != 0) {
449 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
450 goto bad;
451 }
452
453 /*
454 * decrypt the packet.
455 */
456 if (!algo->decrypt) {
457 panic("internal error: no decrypt function");
458 }
459 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_START, 0, 0, 0, 0, 0);
460 if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
461 /* m is already freed */
462 m = NULL;
463 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
464 ipsec_logsastr(sav)));
465 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
466 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 1, 0, 0, 0, 0);
467 goto bad;
468 }
469 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 2, 0, 0, 0, 0);
470 IPSEC_STAT_INCREMENT(ipsecstat.in_esphist[sav->alg_enc]);
471
472 m->m_flags |= M_DECRYPTED;
473
474 if (algo->finalizedecrypt) {
475 if ((*algo->finalizedecrypt)(sav, saved_icv, algo->icvlen)) {
476 ipseclog((LOG_ERR, "esp4 packet decryption ICV failure: %s\n",
477 ipsec_logsastr(sav)));
478 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthfail);
479 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 1, 0, 0, 0, 0);
480 goto bad;
481 } else {
482 m->m_flags |= M_AUTHIPDGM;
483 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthsucc);
484
485 /*
486 * update replay window.
487 */
488 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL) {
489 if (ipsec_updatereplay(seq, sav, (u_int8_t)traffic_class)) {
490 IPSEC_STAT_INCREMENT(ipsecstat.in_espreplay);
491 goto bad;
492 }
493 }
494 }
495 }
496
497 /*
498 * find the trailer of the ESP.
499 */
500 m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
501 (caddr_t)&esptail);
502 nxt = esptail.esp_nxt;
503 taillen = esptail.esp_padlen + sizeof(esptail);
504
505 if (m->m_pkthdr.len < taillen
506 || m->m_pkthdr.len - taillen < hlen) { /*?*/
507 ipseclog((LOG_WARNING,
508 "bad pad length in IPv4 ESP input: %s %s\n",
509 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
510 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
511 goto bad;
512 }
513
514 /* strip off the trailing pad area. */
515 m_adj(m, (int)-taillen);
516 ip = mtod(m, struct ip *);
517 #ifdef IPLEN_FLIPPED
518 ip->ip_len = ip->ip_len - (u_short)taillen;
519 #else
520 ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
521 #endif
522 if (ip->ip_p == IPPROTO_UDP) {
523 // offset includes the outer ip and udp header lengths.
524 if (m->m_len < off) {
525 m = m_pullup(m, off);
526 if (!m) {
527 ipseclog((LOG_DEBUG,
528 "IPv4 ESP input: invalid udp encapsulated ESP packet length \n"));
529 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
530 goto bad;
531 }
532 ip = mtod(m, struct ip *);
533 }
534
535 // check the UDP encap header to detect changes in the source port, and then strip the header
536 off -= sizeof(struct udphdr); // off no longer includes the udphdr's size
537 // if peer is behind nat and this is the latest esp packet
538 if ((sav->flags & SADB_X_EXT_NATT_DETECTED_PEER) != 0 &&
539 (sav->flags & SADB_X_EXT_OLD) == 0 &&
540 seq && sav->replay[traffic_class] &&
541 seq >= sav->replay[traffic_class]->lastseq) {
542 struct udphdr *encap_uh = (__typeof__(encap_uh))(void *)((caddr_t)ip + off);
543 if (encap_uh->uh_sport &&
544 ntohs(encap_uh->uh_sport) != sav->remote_ike_port) {
545 sav->remote_ike_port = ntohs(encap_uh->uh_sport);
546 }
547 }
548 ip = esp4_input_strip_udp_encap(m, off);
549 esp = (struct esp *)(void *)(((u_int8_t *)ip) + off);
550 }
551
552 /* was it transmitted over the IPsec tunnel SA? */
553 if (ipsec4_tunnel_validate(m, (int)(off + esplen + ivlen), nxt, sav, &ifamily)) {
554 ifaddr_t ifa;
555 struct sockaddr_storage addr;
556
557 /*
558 * strip off all the headers that precedes ESP header.
559 * IP4 xx ESP IP4' payload -> IP4' payload
560 *
561 * XXX more sanity checks
562 * XXX relationship with gif?
563 */
564 u_int8_t tos, otos;
565 u_int8_t inner_ip_proto = 0;
566 int sum;
567
568 tos = ip->ip_tos;
569 m_adj(m, (int)(off + esplen + ivlen));
570 if (ifamily == AF_INET) {
571 struct sockaddr_in *ipaddr;
572
573 if (m->m_len < sizeof(*ip)) {
574 m = m_pullup(m, sizeof(*ip));
575 if (!m) {
576 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
577 goto bad;
578 }
579 }
580 ip = mtod(m, struct ip *);
581 /* ECN consideration. */
582
583 otos = ip->ip_tos;
584 if (ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos) == 0) {
585 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
586 goto bad;
587 }
588
589 if (otos != ip->ip_tos) {
590 sum = ~ntohs(ip->ip_sum) & 0xffff;
591 sum += (~otos & 0xffff) + ip->ip_tos;
592 sum = (sum >> 16) + (sum & 0xffff);
593 sum += (sum >> 16); /* add carry */
594 ip->ip_sum = htons(~sum & 0xffff);
595 }
596
597 if (!key_checktunnelsanity(sav, AF_INET,
598 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
599 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
600 "in ESP input: %s %s\n",
601 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
602 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
603 goto bad;
604 }
605
606 inner_ip_proto = ip->ip_p;
607
608 bzero(&addr, sizeof(addr));
609 ipaddr = (__typeof__(ipaddr)) & addr;
610 ipaddr->sin_family = AF_INET;
611 ipaddr->sin_len = sizeof(*ipaddr);
612 ipaddr->sin_addr = ip->ip_dst;
613 } else if (ifamily == AF_INET6) {
614 struct sockaddr_in6 *ip6addr;
615
616 /*
617 * m_pullup is prohibited in KAME IPv6 input processing
618 * but there's no other way!
619 */
620 if (m->m_len < sizeof(*ip6)) {
621 m = m_pullup(m, sizeof(*ip6));
622 if (!m) {
623 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
624 goto bad;
625 }
626 }
627
628 /*
629 * Expect 32-bit aligned data pointer on strict-align
630 * platforms.
631 */
632 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
633
634 ip6 = mtod(m, struct ip6_hdr *);
635
636 /* ECN consideration. */
637 if (ip64_ecn_egress(ip4_ipsec_ecn, &tos, &ip6->ip6_flow) == 0) {
638 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
639 goto bad;
640 }
641
642 if (!key_checktunnelsanity(sav, AF_INET6,
643 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
644 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
645 "in ESP input: %s %s\n",
646 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
647 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
648 goto bad;
649 }
650
651 inner_ip_proto = ip6->ip6_nxt;
652
653 bzero(&addr, sizeof(addr));
654 ip6addr = (__typeof__(ip6addr)) & addr;
655 ip6addr->sin6_family = AF_INET6;
656 ip6addr->sin6_len = sizeof(*ip6addr);
657 ip6addr->sin6_addr = ip6->ip6_dst;
658 } else {
659 ipseclog((LOG_ERR, "ipsec tunnel unsupported address family "
660 "in ESP input\n"));
661 goto bad;
662 }
663
664 key_sa_recordxfer(sav, m);
665 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
666 ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
667 IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
668 goto bad;
669 }
670
671 // update the receiving interface address based on the inner address
672 ifa = ifa_ifwithaddr((struct sockaddr *)&addr);
673 if (ifa) {
674 m->m_pkthdr.rcvif = ifa->ifa_ifp;
675 IFA_REMREF(ifa);
676 }
677
678 /* Clear the csum flags, they can't be valid for the inner headers */
679 m->m_pkthdr.csum_flags = 0;
680
681 // Input via IPsec interface
682 lck_mtx_lock(sadb_mutex);
683 ifnet_t ipsec_if = sav->sah->ipsec_if;
684 if (ipsec_if != NULL) {
685 // If an interface is found, add a reference count before dropping the lock
686 ifnet_reference(ipsec_if);
687 }
688 lck_mtx_unlock(sadb_mutex);
689
690 if ((m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) == PKTF_WAKE_PKT) {
691 if (m->m_pkthdr.rcvif != NULL) {
692 if_ports_used_match_mbuf(m->m_pkthdr.rcvif, ifamily, m);
693 } else {
694 ipseclog((LOG_ERR, "no input interface for ipsec wake packet\n"));
695 }
696 }
697
698 if (ipsec_if != NULL) {
699 esp_input_log(m, sav, spi, seq);
700 ipsec_save_wake_packet(m, ntohl(spi), seq);
701
702 // Return mbuf
703 if (interface != NULL &&
704 interface == ipsec_if) {
705 out_m = m;
706 ifnet_release(ipsec_if);
707 goto done;
708 }
709
710 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
711 ifnet_release(ipsec_if);
712
713 if (inject_error == 0) {
714 m = NULL;
715 goto done;
716 } else {
717 goto bad;
718 }
719 }
720
721 if (proto_input(ifamily == AF_INET ? PF_INET : PF_INET6, m) != 0) {
722 goto bad;
723 }
724
725 nxt = IPPROTO_DONE;
726 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_END, 2, 0, 0, 0, 0);
727 } else {
728 /*
729 * strip off ESP header and IV.
730 * even in m_pulldown case, we need to strip off ESP so that
731 * we can always compute checksum for AH correctly.
732 */
733 size_t stripsiz;
734
735 stripsiz = esplen + ivlen;
736
737 ip = mtod(m, struct ip *);
738 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
739 m->m_data += stripsiz;
740 m->m_len -= stripsiz;
741 m->m_pkthdr.len -= stripsiz;
742
743 ip = mtod(m, struct ip *);
744 #ifdef IPLEN_FLIPPED
745 ip->ip_len = ip->ip_len - (u_short)stripsiz;
746 #else
747 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
748 #endif
749 ip->ip_p = (u_int8_t)nxt;
750
751 key_sa_recordxfer(sav, m);
752 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
753 IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
754 goto bad;
755 }
756
757 /*
758 * Set the csum valid flag, if we authenticated the
759 * packet, the payload shouldn't be corrupt unless
760 * it was corrupted before being signed on the other
761 * side.
762 */
763 if (nxt == IPPROTO_TCP || nxt == IPPROTO_UDP) {
764 m->m_pkthdr.csum_flags = CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
765 m->m_pkthdr.csum_data = 0xFFFF;
766 _CASSERT(offsetof(struct pkthdr, csum_data) == offsetof(struct pkthdr, csum_rx_val));
767 }
768
769 if (nxt != IPPROTO_DONE) {
770 if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
771 ipsec4_in_reject(m, NULL)) {
772 IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
773 goto bad;
774 }
775 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_END, 3, 0, 0, 0, 0);
776
777 /* translate encapsulated UDP port ? */
778 if ((sav->flags & SADB_X_EXT_NATT_MULTIPLEUSERS) != 0) {
779 struct udphdr *udp;
780
781 if (nxt != IPPROTO_UDP) { /* not UPD packet - drop it */
782 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
783 goto bad;
784 }
785
786 if (m->m_len < off + sizeof(struct udphdr)) {
787 m = m_pullup(m, off + sizeof(struct udphdr));
788 if (!m) {
789 ipseclog((LOG_DEBUG,
790 "IPv4 ESP input: can't pullup UDP header in esp4_input\n"));
791 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
792 goto bad;
793 }
794 ip = mtod(m, struct ip *);
795 }
796 udp = (struct udphdr *)(void *)(((u_int8_t *)ip) + off);
797
798 lck_mtx_lock(sadb_mutex);
799 if (sav->natt_encapsulated_src_port == 0) {
800 sav->natt_encapsulated_src_port = udp->uh_sport;
801 } else if (sav->natt_encapsulated_src_port != udp->uh_sport) { /* something wrong */
802 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
803 lck_mtx_unlock(sadb_mutex);
804 goto bad;
805 }
806 lck_mtx_unlock(sadb_mutex);
807 udp->uh_sport = htons(sav->remote_ike_port);
808 udp->uh_sum = 0;
809 }
810
811 DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
812 struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
813 struct ip *, ip, struct ip6_hdr *, NULL);
814
815 // Input via IPsec interface legacy path
816 lck_mtx_lock(sadb_mutex);
817 ifnet_t ipsec_if = sav->sah->ipsec_if;
818 if (ipsec_if != NULL) {
819 // If an interface is found, add a reference count before dropping the lock
820 ifnet_reference(ipsec_if);
821 }
822 lck_mtx_unlock(sadb_mutex);
823 if (ipsec_if != NULL) {
824 int mlen;
825 if ((mlen = m_length2(m, NULL)) < hlen) {
826 ipseclog((LOG_DEBUG,
827 "IPv4 ESP input: decrypted packet too short %d < %u\n",
828 mlen, hlen));
829 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
830 ifnet_release(ipsec_if);
831 goto bad;
832 }
833 ip->ip_len = htons(ip->ip_len + hlen);
834 ip->ip_off = htons(ip->ip_off);
835 ip->ip_sum = 0;
836 ip->ip_sum = ip_cksum_hdr_in(m, hlen);
837
838 esp_input_log(m, sav, spi, seq);
839 ipsec_save_wake_packet(m, ntohl(spi), seq);
840
841 if ((m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) == PKTF_WAKE_PKT) {
842 if_ports_used_match_mbuf(ipsec_if, PF_INET, m);
843 }
844
845 // Return mbuf
846 if (interface != NULL &&
847 interface == ipsec_if) {
848 out_m = m;
849 ifnet_release(ipsec_if);
850 goto done;
851 }
852
853 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
854 ifnet_release(ipsec_if);
855
856 if (inject_error == 0) {
857 m = NULL;
858 goto done;
859 } else {
860 goto bad;
861 }
862 }
863
864 if ((m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) == PKTF_WAKE_PKT) {
865 if_ports_used_match_mbuf(m->m_pkthdr.rcvif, PF_INET, m);
866 if (m->m_pkthdr.rcvif == NULL) {
867 ipseclog((LOG_ERR, "no input interface for ipsec wake packet\n"));
868 }
869 }
870
871 ip_proto_dispatch_in(m, off, (u_int8_t)nxt, 0);
872 } else {
873 m_freem(m);
874 }
875 m = NULL;
876 }
877
878 done:
879 if (sav) {
880 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
881 printf("DP esp4_input call free SA:0x%llx\n",
882 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
883 key_freesav(sav, KEY_SADB_UNLOCKED);
884 }
885 IPSEC_STAT_INCREMENT(ipsecstat.in_success);
886 return out_m;
887 bad:
888 if (sav) {
889 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
890 printf("DP esp4_input call free SA:0x%llx\n",
891 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
892 key_freesav(sav, KEY_SADB_UNLOCKED);
893 }
894 if (m) {
895 m_freem(m);
896 }
897 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_END, 4, 0, 0, 0, 0);
898 return out_m;
899 }
900
901 int
esp6_input(struct mbuf ** mp,int * offp,int proto)902 esp6_input(struct mbuf **mp, int *offp, int proto)
903 {
904 return esp6_input_extended(mp, offp, proto, NULL);
905 }
906
907 int
esp6_input_extended(struct mbuf ** mp,int * offp,int proto,ifnet_t interface)908 esp6_input_extended(struct mbuf **mp, int *offp, int proto, ifnet_t interface)
909 {
910 #pragma unused(proto)
911 struct mbuf *m = *mp;
912 int off = *offp;
913 struct ip *ip;
914 struct ip6_hdr *ip6;
915 struct esp *esp;
916 struct esptail esptail;
917 u_int32_t spi;
918 u_int32_t seq;
919 struct secasvar *sav = NULL;
920 u_int16_t nxt;
921 char *nproto;
922 const struct esp_algorithm *algo;
923 int ivlen;
924 size_t esplen;
925 u_int16_t taillen;
926 sa_family_t ifamily;
927 mbuf_traffic_class_t traffic_class = 0;
928
929 /* sanity check for alignment. */
930 if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
931 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
932 "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
933 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
934 goto bad;
935 }
936
937 #ifndef PULLDOWN_TEST
938 IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, {return IPPROTO_DONE;});
939 esp = (struct esp *)(void *)(mtod(m, caddr_t) + off);
940 #else
941 IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
942 if (esp == NULL) {
943 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
944 return IPPROTO_DONE;
945 }
946 #endif
947 m->m_pkthdr.csum_flags &= ~CSUM_RX_FLAGS;
948
949 /* Expect 32-bit data aligned pointer on strict-align platforms */
950 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
951
952 ip6 = mtod(m, struct ip6_hdr *);
953
954 if (ntohs(ip6->ip6_plen) == 0) {
955 ipseclog((LOG_ERR, "IPv6 ESP input: "
956 "ESP with IPv6 jumbogram is not supported.\n"));
957 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
958 goto bad;
959 }
960
961 nproto = ip6_get_prevhdr(m, off);
962 if (nproto == NULL || (*nproto != IPPROTO_ESP &&
963 !(*nproto == IPPROTO_UDP && off >= sizeof(struct udphdr)))) {
964 ipseclog((LOG_DEBUG, "IPv6 ESP input: invalid protocol type\n"));
965 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
966 goto bad;
967 }
968
969 /* find the sassoc. */
970 spi = esp->esp_spi;
971
972 if ((sav = key_allocsa_extended(AF_INET6,
973 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, interface != NULL ? interface->if_index : IFSCOPE_UNKNOWN,
974 IPPROTO_ESP, spi, interface)) == 0) {
975 ipseclog((LOG_WARNING,
976 "IPv6 ESP input: no key association found for spi %u (0x%08x) seq %u"
977 " src %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
978 " dst %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x if %s\n",
979 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi), ntohl(((struct newesp *)esp)->esp_seq),
980 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[0]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[1]),
981 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[2]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[3]),
982 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[4]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[5]),
983 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[6]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[7]),
984 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[0]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[1]),
985 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[2]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[3]),
986 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[4]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[5]),
987 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[6]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[7]),
988 ((interface != NULL) ? if_name(interface) : "NONE")));
989 IPSEC_STAT_INCREMENT(ipsec6stat.in_nosa);
990 goto bad;
991 }
992 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
993 printf("DP esp6_input called to allocate SA:0x%llx\n",
994 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
995 if (sav->state != SADB_SASTATE_MATURE
996 && sav->state != SADB_SASTATE_DYING) {
997 ipseclog((LOG_DEBUG,
998 "IPv6 ESP input: non-mature/dying SA found for spi %u (0x%08x)\n",
999 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
1000 IPSEC_STAT_INCREMENT(ipsec6stat.in_badspi);
1001 goto bad;
1002 }
1003 algo = esp_algorithm_lookup(sav->alg_enc);
1004 if (!algo) {
1005 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
1006 "unsupported encryption algorithm for spi %u (0x%08x)\n",
1007 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
1008 IPSEC_STAT_INCREMENT(ipsec6stat.in_badspi);
1009 goto bad;
1010 }
1011
1012 /* check if we have proper ivlen information */
1013 ivlen = sav->ivlen;
1014 if (ivlen < 0) {
1015 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
1016 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1017 IPSEC_STAT_INCREMENT(ipsec6stat.in_badspi);
1018 goto bad;
1019 }
1020
1021 seq = ntohl(((struct newesp *)esp)->esp_seq);
1022
1023 if ((sav->flags2 & SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) ==
1024 SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) {
1025 u_int8_t dscp = (ntohl(ip6->ip6_flow) & IP6FLOW_DSCP_MASK) >> IP6FLOW_DSCP_SHIFT;
1026 traffic_class = rfc4594_dscp_to_tc(dscp);
1027 }
1028
1029 if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL &&
1030 ((sav->alg_auth && sav->key_auth) || algo->finalizedecrypt))) {
1031 goto noreplaycheck;
1032 }
1033
1034 if ((sav->alg_auth == SADB_X_AALG_NULL || sav->alg_auth == SADB_AALG_NONE) &&
1035 !algo->finalizedecrypt) {
1036 goto noreplaycheck;
1037 }
1038
1039 /*
1040 * check for sequence number.
1041 */
1042 if (ipsec_chkreplay(seq, sav, (u_int8_t)traffic_class)) {
1043 ; /*okey*/
1044 } else {
1045 IPSEC_STAT_INCREMENT(ipsec6stat.in_espreplay);
1046 ipseclog((LOG_WARNING,
1047 "replay packet in IPv6 ESP input: seq(%u) tc(%u) %s %s\n",
1048 seq, (u_int8_t)traffic_class, ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1049 goto bad;
1050 }
1051
1052 /* Save ICV from packet for verification later */
1053 size_t siz = 0;
1054 unsigned char saved_icv[AH_MAXSUMSIZE] __attribute__((aligned(4)));
1055 if (algo->finalizedecrypt) {
1056 siz = algo->icvlen;
1057 VERIFY(siz <= UINT16_MAX);
1058 m_copydata(m, m->m_pkthdr.len - (int)siz, (int)siz, (caddr_t) saved_icv);
1059 } else {
1060 /* check ICV immediately */
1061 u_char sum0[AH_MAXSUMSIZE] __attribute__((aligned(4)));
1062 u_char sum[AH_MAXSUMSIZE] __attribute__((aligned(4)));
1063 const struct ah_algorithm *sumalgo;
1064
1065 sumalgo = ah_algorithm_lookup(sav->alg_auth);
1066 if (!sumalgo) {
1067 goto noreplaycheck;
1068 }
1069 siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
1070 if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
1071 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1072 goto bad;
1073 }
1074 if (AH_MAXSUMSIZE < siz) {
1075 ipseclog((LOG_DEBUG,
1076 "internal error: AH_MAXSUMSIZE must be larger than %u\n",
1077 (u_int32_t)siz));
1078 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1079 goto bad;
1080 }
1081
1082 m_copydata(m, m->m_pkthdr.len - (int)siz, (int)siz, (caddr_t) &sum0[0]);
1083
1084 if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
1085 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
1086 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1087 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthfail);
1088 goto bad;
1089 }
1090
1091 if (cc_cmp_safe(siz, sum0, sum)) {
1092 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
1093 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1094 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthfail);
1095 goto bad;
1096 }
1097
1098 m->m_flags |= M_AUTHIPDGM;
1099 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthsucc);
1100
1101 /*
1102 * update replay window.
1103 */
1104 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL) {
1105 if (ipsec_updatereplay(seq, sav, (u_int8_t)traffic_class)) {
1106 IPSEC_STAT_INCREMENT(ipsec6stat.in_espreplay);
1107 goto bad;
1108 }
1109 }
1110 }
1111
1112 /* strip off the authentication data */
1113 m_adj(m, (int)-siz);
1114 ip6 = mtod(m, struct ip6_hdr *);
1115 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - (u_int16_t)siz);
1116
1117 noreplaycheck:
1118
1119 /* process main esp header. */
1120 if (sav->flags & SADB_X_EXT_OLD) {
1121 /* RFC 1827 */
1122 esplen = sizeof(struct esp);
1123 } else {
1124 /* RFC 2406 */
1125 if (sav->flags & SADB_X_EXT_DERIV) {
1126 esplen = sizeof(struct esp);
1127 } else {
1128 esplen = sizeof(struct newesp);
1129 }
1130 }
1131
1132 if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
1133 ipseclog((LOG_WARNING,
1134 "IPv6 ESP input: packet too short\n"));
1135 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1136 goto bad;
1137 }
1138
1139 #ifndef PULLDOWN_TEST
1140 IP6_EXTHDR_CHECK(m, off, (int)(esplen + ivlen), return IPPROTO_DONE); /*XXX*/
1141 #else
1142 IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
1143 if (esp == NULL) {
1144 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1145 m = NULL;
1146 goto bad;
1147 }
1148 #endif
1149 ip6 = mtod(m, struct ip6_hdr *); /*set it again just in case*/
1150
1151 /*
1152 * pre-compute and cache intermediate key
1153 */
1154 if (esp_schedule(algo, sav) != 0) {
1155 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1156 goto bad;
1157 }
1158
1159 /*
1160 * decrypt the packet.
1161 */
1162 if (!algo->decrypt) {
1163 panic("internal error: no decrypt function");
1164 }
1165 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_START, 0, 0, 0, 0, 0);
1166 if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
1167 /* m is already freed */
1168 m = NULL;
1169 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
1170 ipsec_logsastr(sav)));
1171 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1172 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 1, 0, 0, 0, 0);
1173 goto bad;
1174 }
1175 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 2, 0, 0, 0, 0);
1176 IPSEC_STAT_INCREMENT(ipsec6stat.in_esphist[sav->alg_enc]);
1177
1178 m->m_flags |= M_DECRYPTED;
1179
1180 if (algo->finalizedecrypt) {
1181 if ((*algo->finalizedecrypt)(sav, saved_icv, algo->icvlen)) {
1182 ipseclog((LOG_ERR, "esp6 packet decryption ICV failure: %s\n",
1183 ipsec_logsastr(sav)));
1184 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthfail);
1185 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 1, 0, 0, 0, 0);
1186 goto bad;
1187 } else {
1188 m->m_flags |= M_AUTHIPDGM;
1189 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthsucc);
1190
1191 /*
1192 * update replay window.
1193 */
1194 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL) {
1195 if (ipsec_updatereplay(seq, sav, (u_int8_t)traffic_class)) {
1196 IPSEC_STAT_INCREMENT(ipsec6stat.in_espreplay);
1197 goto bad;
1198 }
1199 }
1200 }
1201 }
1202
1203 /*
1204 * find the trailer of the ESP.
1205 */
1206 m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
1207 (caddr_t)&esptail);
1208 nxt = esptail.esp_nxt;
1209 taillen = esptail.esp_padlen + sizeof(esptail);
1210
1211 if (m->m_pkthdr.len < taillen
1212 || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) { /*?*/
1213 ipseclog((LOG_WARNING,
1214 "bad pad length in IPv6 ESP input: %s %s\n",
1215 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1216 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1217 goto bad;
1218 }
1219
1220 /* strip off the trailing pad area. */
1221 m_adj(m, -taillen);
1222 ip6 = mtod(m, struct ip6_hdr *);
1223 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
1224
1225 if (*nproto == IPPROTO_UDP) {
1226 // offset includes the outer ip and udp header lengths.
1227 if (m->m_len < off) {
1228 m = m_pullup(m, off);
1229 if (!m) {
1230 ipseclog((LOG_DEBUG,
1231 "IPv6 ESP input: invalid udp encapsulated ESP packet length\n"));
1232 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1233 goto bad;
1234 }
1235 ip6 = mtod(m, struct ip6_hdr *);
1236 }
1237
1238 // check the UDP encap header to detect changes in the source port, and then strip the header
1239 off -= sizeof(struct udphdr); // off no longer includes the udphdr's size
1240 // if peer is behind nat and this is the latest esp packet
1241 if ((sav->flags & SADB_X_EXT_NATT_DETECTED_PEER) != 0 &&
1242 (sav->flags & SADB_X_EXT_OLD) == 0 &&
1243 seq && sav->replay[traffic_class] &&
1244 seq >= sav->replay[traffic_class]->lastseq) {
1245 struct udphdr *encap_uh = (__typeof__(encap_uh))(void *)((caddr_t)ip6 + off);
1246 if (encap_uh->uh_sport &&
1247 ntohs(encap_uh->uh_sport) != sav->remote_ike_port) {
1248 sav->remote_ike_port = ntohs(encap_uh->uh_sport);
1249 }
1250 }
1251 ip6 = esp6_input_strip_udp_encap(m, off);
1252 esp = (struct esp *)(void *)(((u_int8_t *)ip6) + off);
1253 }
1254
1255
1256 /* was it transmitted over the IPsec tunnel SA? */
1257 if (ipsec6_tunnel_validate(m, (int)(off + esplen + ivlen), nxt, sav, &ifamily)) {
1258 ifaddr_t ifa;
1259 struct sockaddr_storage addr;
1260 u_int8_t inner_ip_proto = 0;
1261
1262 /*
1263 * strip off all the headers that precedes ESP header.
1264 * IP6 xx ESP IP6' payload -> IP6' payload
1265 *
1266 * XXX more sanity checks
1267 * XXX relationship with gif?
1268 */
1269 u_int32_t flowinfo; /*net endian*/
1270 flowinfo = ip6->ip6_flow;
1271 m_adj(m, (int)(off + esplen + ivlen));
1272 if (ifamily == AF_INET6) {
1273 struct sockaddr_in6 *ip6addr;
1274
1275 if (m->m_len < sizeof(*ip6)) {
1276 #ifndef PULLDOWN_TEST
1277 /*
1278 * m_pullup is prohibited in KAME IPv6 input processing
1279 * but there's no other way!
1280 */
1281 #else
1282 /* okay to pullup in m_pulldown style */
1283 #endif
1284 m = m_pullup(m, sizeof(*ip6));
1285 if (!m) {
1286 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1287 goto bad;
1288 }
1289 }
1290 ip6 = mtod(m, struct ip6_hdr *);
1291 /* ECN consideration. */
1292 if (ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow) == 0) {
1293 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1294 goto bad;
1295 }
1296 if (!key_checktunnelsanity(sav, AF_INET6,
1297 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
1298 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
1299 "in IPv6 ESP input: %s %s\n",
1300 ipsec6_logpacketstr(ip6, spi),
1301 ipsec_logsastr(sav)));
1302 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1303 goto bad;
1304 }
1305
1306 inner_ip_proto = ip6->ip6_nxt;
1307
1308 bzero(&addr, sizeof(addr));
1309 ip6addr = (__typeof__(ip6addr)) & addr;
1310 ip6addr->sin6_family = AF_INET6;
1311 ip6addr->sin6_len = sizeof(*ip6addr);
1312 ip6addr->sin6_addr = ip6->ip6_dst;
1313 } else if (ifamily == AF_INET) {
1314 struct sockaddr_in *ipaddr;
1315
1316 if (m->m_len < sizeof(*ip)) {
1317 m = m_pullup(m, sizeof(*ip));
1318 if (!m) {
1319 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1320 goto bad;
1321 }
1322 }
1323
1324 u_int8_t otos;
1325 int sum;
1326
1327 ip = mtod(m, struct ip *);
1328 otos = ip->ip_tos;
1329 /* ECN consideration. */
1330 if (ip46_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip->ip_tos) == 0) {
1331 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1332 goto bad;
1333 }
1334
1335 if (otos != ip->ip_tos) {
1336 sum = ~ntohs(ip->ip_sum) & 0xffff;
1337 sum += (~otos & 0xffff) + ip->ip_tos;
1338 sum = (sum >> 16) + (sum & 0xffff);
1339 sum += (sum >> 16); /* add carry */
1340 ip->ip_sum = htons(~sum & 0xffff);
1341 }
1342
1343 if (!key_checktunnelsanity(sav, AF_INET,
1344 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
1345 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
1346 "in ESP input: %s %s\n",
1347 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
1348 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1349 goto bad;
1350 }
1351
1352 inner_ip_proto = ip->ip_p;
1353
1354 bzero(&addr, sizeof(addr));
1355 ipaddr = (__typeof__(ipaddr)) & addr;
1356 ipaddr->sin_family = AF_INET;
1357 ipaddr->sin_len = sizeof(*ipaddr);
1358 ipaddr->sin_addr = ip->ip_dst;
1359 }
1360
1361 key_sa_recordxfer(sav, m);
1362 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
1363 ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
1364 IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
1365 goto bad;
1366 }
1367
1368 // update the receiving interface address based on the inner address
1369 ifa = ifa_ifwithaddr((struct sockaddr *)&addr);
1370 if (ifa) {
1371 m->m_pkthdr.rcvif = ifa->ifa_ifp;
1372 IFA_REMREF(ifa);
1373 }
1374
1375 // Input via IPsec interface
1376 lck_mtx_lock(sadb_mutex);
1377 ifnet_t ipsec_if = sav->sah->ipsec_if;
1378 if (ipsec_if != NULL) {
1379 // If an interface is found, add a reference count before dropping the lock
1380 ifnet_reference(ipsec_if);
1381 }
1382 lck_mtx_unlock(sadb_mutex);
1383
1384 if ((m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) == PKTF_WAKE_PKT) {
1385 if_ports_used_match_mbuf(m->m_pkthdr.rcvif, ifamily, m);
1386 if (m->m_pkthdr.rcvif == NULL) {
1387 ipseclog((LOG_ERR, "no input interface for ipsec wake packet\n"));
1388 }
1389 }
1390
1391 if (ipsec_if != NULL) {
1392 esp_input_log(m, sav, spi, seq);
1393 ipsec_save_wake_packet(m, ntohl(spi), seq);
1394
1395 // Return mbuf
1396 if (interface != NULL &&
1397 interface == ipsec_if) {
1398 ifnet_release(ipsec_if);
1399 goto done;
1400 }
1401
1402 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
1403 ifnet_release(ipsec_if);
1404
1405 if (inject_error == 0) {
1406 m = NULL;
1407 nxt = IPPROTO_DONE;
1408 goto done;
1409 } else {
1410 goto bad;
1411 }
1412 }
1413
1414 if (proto_input(ifamily == AF_INET ? PF_INET : PF_INET6, m) != 0) {
1415 goto bad;
1416 }
1417 nxt = IPPROTO_DONE;
1418 } else {
1419 /*
1420 * strip off ESP header and IV.
1421 * even in m_pulldown case, we need to strip off ESP so that
1422 * we can always compute checksum for AH correctly.
1423 */
1424 u_int16_t stripsiz;
1425 char *prvnxtp;
1426
1427 /*
1428 * Set the next header field of the previous header correctly.
1429 */
1430 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
1431 *prvnxtp = (u_int8_t)nxt;
1432
1433 VERIFY(esplen + ivlen <= UINT16_MAX);
1434 stripsiz = (u_int16_t)(esplen + ivlen);
1435
1436 ip6 = mtod(m, struct ip6_hdr *);
1437 if (m->m_len >= stripsiz + off) {
1438 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
1439 m->m_data += stripsiz;
1440 m->m_len -= stripsiz;
1441 m->m_pkthdr.len -= stripsiz;
1442 } else {
1443 /*
1444 * this comes with no copy if the boundary is on
1445 * cluster
1446 */
1447 struct mbuf *n;
1448
1449 n = m_split(m, off, M_DONTWAIT);
1450 if (n == NULL) {
1451 /* m is retained by m_split */
1452 goto bad;
1453 }
1454 m_adj(n, stripsiz);
1455 /* m_cat does not update m_pkthdr.len */
1456 m->m_pkthdr.len += n->m_pkthdr.len;
1457 m_cat(m, n);
1458 }
1459
1460 #ifndef PULLDOWN_TEST
1461 /*
1462 * KAME requires that the packet to be contiguous on the
1463 * mbuf. We need to make that sure.
1464 * this kind of code should be avoided.
1465 * XXX other conditions to avoid running this part?
1466 */
1467 if (m->m_len != m->m_pkthdr.len) {
1468 struct mbuf *n = NULL;
1469 int maxlen;
1470
1471 MGETHDR(n, M_DONTWAIT, MT_HEADER); /* MAC-OK */
1472 maxlen = MHLEN;
1473 if (n) {
1474 M_COPY_PKTHDR(n, m);
1475 }
1476 if (n && m->m_pkthdr.len > maxlen) {
1477 MCLGET(n, M_DONTWAIT);
1478 maxlen = MCLBYTES;
1479 if ((n->m_flags & M_EXT) == 0) {
1480 m_free(n);
1481 n = NULL;
1482 }
1483 }
1484 if (!n) {
1485 printf("esp6_input: mbuf allocation failed\n");
1486 goto bad;
1487 }
1488
1489 if (m->m_pkthdr.len <= maxlen) {
1490 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
1491 n->m_len = m->m_pkthdr.len;
1492 n->m_pkthdr.len = m->m_pkthdr.len;
1493 n->m_next = NULL;
1494 m_freem(m);
1495 } else {
1496 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
1497 n->m_len = maxlen;
1498 n->m_pkthdr.len = m->m_pkthdr.len;
1499 n->m_next = m;
1500 m_adj(m, maxlen);
1501 m->m_flags &= ~M_PKTHDR;
1502 }
1503 m = n;
1504 }
1505 #endif
1506 ip6 = mtod(m, struct ip6_hdr *);
1507 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
1508
1509 key_sa_recordxfer(sav, m);
1510 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
1511 IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
1512 goto bad;
1513 }
1514
1515 /*
1516 * Set the csum valid flag, if we authenticated the
1517 * packet, the payload shouldn't be corrupt unless
1518 * it was corrupted before being signed on the other
1519 * side.
1520 */
1521 if (nxt == IPPROTO_TCP || nxt == IPPROTO_UDP) {
1522 m->m_pkthdr.csum_flags = CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1523 m->m_pkthdr.csum_data = 0xFFFF;
1524 _CASSERT(offsetof(struct pkthdr, csum_data) == offsetof(struct pkthdr, csum_rx_val));
1525 }
1526
1527 // Input via IPsec interface
1528 lck_mtx_lock(sadb_mutex);
1529 ifnet_t ipsec_if = sav->sah->ipsec_if;
1530 if (ipsec_if != NULL) {
1531 // If an interface is found, add a reference count before dropping the lock
1532 ifnet_reference(ipsec_if);
1533 }
1534 lck_mtx_unlock(sadb_mutex);
1535 if (ipsec_if != NULL) {
1536 esp_input_log(m, sav, spi, seq);
1537 ipsec_save_wake_packet(m, ntohl(spi), seq);
1538
1539 if ((m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) == PKTF_WAKE_PKT) {
1540 if_ports_used_match_mbuf(ipsec_if, PF_INET6, m);
1541 }
1542
1543 // Return mbuf
1544 if (interface != NULL &&
1545 interface == ipsec_if) {
1546 ifnet_release(ipsec_if);
1547 goto done;
1548 }
1549
1550 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
1551 ifnet_release(ipsec_if);
1552
1553 if (inject_error == 0) {
1554 m = NULL;
1555 nxt = IPPROTO_DONE;
1556 goto done;
1557 } else {
1558 goto bad;
1559 }
1560 } else {
1561 if ((m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) == PKTF_WAKE_PKT) {
1562 if_ports_used_match_mbuf(m->m_pkthdr.rcvif, PF_INET, m);
1563 if (m->m_pkthdr.rcvif == NULL) {
1564 ipseclog((LOG_ERR, "no input interface for ipsec wake packet\n"));
1565 }
1566 }
1567 }
1568 }
1569
1570 done:
1571 *offp = off;
1572 *mp = m;
1573 if (sav) {
1574 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1575 printf("DP esp6_input call free SA:0x%llx\n",
1576 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
1577 key_freesav(sav, KEY_SADB_UNLOCKED);
1578 }
1579 IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
1580 return nxt;
1581
1582 bad:
1583 if (sav) {
1584 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1585 printf("DP esp6_input call free SA:0x%llx\n",
1586 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
1587 key_freesav(sav, KEY_SADB_UNLOCKED);
1588 }
1589 if (m) {
1590 m_freem(m);
1591 }
1592 if (interface != NULL) {
1593 *mp = NULL;
1594 }
1595 return IPPROTO_DONE;
1596 }
1597
1598 void
esp6_ctlinput(int cmd,struct sockaddr * sa,void * d,__unused struct ifnet * ifp)1599 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d, __unused struct ifnet *ifp)
1600 {
1601 const struct newesp *espp;
1602 struct newesp esp;
1603 struct ip6ctlparam *ip6cp = NULL, ip6cp1;
1604 struct secasvar *sav;
1605 struct ip6_hdr *ip6;
1606 struct mbuf *m;
1607 int off = 0;
1608 struct sockaddr_in6 *sa6_src, *sa6_dst;
1609
1610 if (sa->sa_family != AF_INET6 ||
1611 sa->sa_len != sizeof(struct sockaddr_in6)) {
1612 return;
1613 }
1614 if ((unsigned)cmd >= PRC_NCMDS) {
1615 return;
1616 }
1617
1618 /* if the parameter is from icmp6, decode it. */
1619 if (d != NULL) {
1620 ip6cp = (struct ip6ctlparam *)d;
1621 m = ip6cp->ip6c_m;
1622 ip6 = ip6cp->ip6c_ip6;
1623 off = ip6cp->ip6c_off;
1624 } else {
1625 m = NULL;
1626 ip6 = NULL;
1627 }
1628
1629 if (ip6) {
1630 /*
1631 * Notify the error to all possible sockets via pfctlinput2.
1632 * Since the upper layer information (such as protocol type,
1633 * source and destination ports) is embedded in the encrypted
1634 * data and might have been cut, we can't directly call
1635 * an upper layer ctlinput function. However, the pcbnotify
1636 * function will consider source and destination addresses
1637 * as well as the flow info value, and may be able to find
1638 * some PCB that should be notified.
1639 * Although pfctlinput2 will call esp6_ctlinput(), there is
1640 * no possibility of an infinite loop of function calls,
1641 * because we don't pass the inner IPv6 header.
1642 */
1643 bzero(&ip6cp1, sizeof(ip6cp1));
1644 ip6cp1.ip6c_src = ip6cp->ip6c_src;
1645 pfctlinput2(cmd, sa, (void *)&ip6cp1);
1646
1647 /*
1648 * Then go to special cases that need ESP header information.
1649 * XXX: We assume that when ip6 is non NULL,
1650 * M and OFF are valid.
1651 */
1652
1653 /* check if we can safely examine src and dst ports */
1654 if (m->m_pkthdr.len < off + sizeof(esp)) {
1655 return;
1656 }
1657
1658 if (m->m_len < off + sizeof(esp)) {
1659 /*
1660 * this should be rare case,
1661 * so we compromise on this copy...
1662 */
1663 m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
1664 espp = &esp;
1665 } else {
1666 espp = (struct newesp*)(void *)(mtod(m, caddr_t) + off);
1667 }
1668
1669 if (cmd == PRC_MSGSIZE) {
1670 int valid = 0;
1671
1672 /*
1673 * Check to see if we have a valid SA corresponding to
1674 * the address in the ICMP message payload.
1675 */
1676 sa6_src = ip6cp->ip6c_src;
1677 sa6_dst = (struct sockaddr_in6 *)(void *)sa;
1678 sav = key_allocsa(AF_INET6,
1679 (caddr_t)&sa6_src->sin6_addr,
1680 (caddr_t)&sa6_dst->sin6_addr,
1681 sa6_dst->sin6_scope_id,
1682 IPPROTO_ESP, espp->esp_spi);
1683 if (sav) {
1684 if (sav->state == SADB_SASTATE_MATURE ||
1685 sav->state == SADB_SASTATE_DYING) {
1686 valid++;
1687 }
1688 key_freesav(sav, KEY_SADB_UNLOCKED);
1689 }
1690
1691 /* XXX Further validation? */
1692
1693 /*
1694 * Depending on the value of "valid" and routing table
1695 * size (mtudisc_{hi,lo}wat), we will:
1696 * - recalcurate the new MTU and create the
1697 * corresponding routing entry, or
1698 * - ignore the MTU change notification.
1699 */
1700 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1701 }
1702 } else {
1703 /* we normally notify any pcb here */
1704 }
1705 }
1706