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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/route.h>
83 #include <kern/cpu_number.h>
84 #include <kern/locks.h>
85
86 #include <netinet/in.h>
87 #include <netinet/in_systm.h>
88 #include <netinet/ip.h>
89 #include <netinet/ip_var.h>
90 #include <netinet/in_var.h>
91 #include <netinet/ip_ecn.h>
92 #include <netinet/in_pcb.h>
93 #include <netinet/udp.h>
94 #include <netinet/tcp.h>
95 #include <netinet/in_tclass.h>
96 #if INET6
97 #include <netinet6/ip6_ecn.h>
98 #endif
99
100 #if INET6
101 #include <netinet/ip6.h>
102 #include <netinet6/in6_pcb.h>
103 #include <netinet6/ip6_var.h>
104 #include <netinet/icmp6.h>
105 #include <netinet6/ip6protosw.h>
106 #endif
107
108 #include <netinet6/ipsec.h>
109 #if INET6
110 #include <netinet6/ipsec6.h>
111 #endif
112 #include <netinet6/ah.h>
113 #if INET6
114 #include <netinet6/ah6.h>
115 #endif
116 #include <netinet6/esp.h>
117 #if INET6
118 #include <netinet6/esp6.h>
119 #endif
120 #include <netkey/key.h>
121 #include <netkey/keydb.h>
122 #include <netkey/key_debug.h>
123
124 #include <net/kpi_protocol.h>
125 #include <netinet/kpi_ipfilter_var.h>
126
127 #include <net/net_osdep.h>
128 #include <mach/sdt.h>
129 #include <corecrypto/cc.h>
130
131 #include <sys/kdebug.h>
132 #define DBG_LAYER_BEG NETDBG_CODE(DBG_NETIPSEC, 1)
133 #define DBG_LAYER_END NETDBG_CODE(DBG_NETIPSEC, 3)
134 #define DBG_FNC_ESPIN NETDBG_CODE(DBG_NETIPSEC, (6 << 8))
135 #define DBG_FNC_DECRYPT NETDBG_CODE(DBG_NETIPSEC, (7 << 8))
136 #define IPLEN_FLIPPED
137
138 extern lck_mtx_t *sadb_mutex;
139
140 #if INET
141 #define ESPMAXLEN \
142 (sizeof(struct esp) < sizeof(struct newesp) \
143 ? sizeof(struct newesp) : sizeof(struct esp))
144
145 static struct ip *
146 esp4_input_strip_udp_encap(struct mbuf *m, int iphlen)
147 {
148 // strip the udp header that's encapsulating ESP
149 struct ip *ip;
150 size_t stripsiz = sizeof(struct udphdr);
151
152 ip = mtod(m, __typeof__(ip));
153 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), iphlen);
154 m->m_data += stripsiz;
155 m->m_len -= stripsiz;
156 m->m_pkthdr.len -= stripsiz;
157 ip = mtod(m, __typeof__(ip));
158 ip->ip_len = ip->ip_len - stripsiz;
159 ip->ip_p = IPPROTO_ESP;
160 return ip;
161 }
162
163 static struct ip6_hdr *
164 esp6_input_strip_udp_encap(struct mbuf *m, int ip6hlen)
165 {
166 // strip the udp header that's encapsulating ESP
167 struct ip6_hdr *ip6;
168 size_t stripsiz = sizeof(struct udphdr);
169
170 ip6 = mtod(m, __typeof__(ip6));
171 ovbcopy((caddr_t)ip6, (caddr_t)(((u_char *)ip6) + stripsiz), ip6hlen);
172 m->m_data += stripsiz;
173 m->m_len -= stripsiz;
174 m->m_pkthdr.len -= stripsiz;
175 ip6 = mtod(m, __typeof__(ip6));
176 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
177 ip6->ip6_nxt = IPPROTO_ESP;
178 return ip6;
179 }
180
181 static void
182 esp_input_log(struct mbuf *m, struct secasvar *sav, u_int32_t spi, u_int32_t seq)
183 {
184 if (net_mpklog_enabled &&
185 (sav->sah->ipsec_if->if_xflags & IFXF_MPK_LOG) == IFXF_MPK_LOG) {
186 struct tcphdr th = {};
187 size_t iphlen = 0;
188 u_int32_t proto_len = 0;
189 u_int8_t proto = 0;
190
191 struct ip *inner_ip = mtod(m, struct ip *);
192 if (IP_VHL_V(inner_ip->ip_vhl) == 4) {
193 iphlen = IP_VHL_HL(inner_ip->ip_vhl) << 2;
194 proto = inner_ip->ip_p;
195 } else if (IP_VHL_V(inner_ip->ip_vhl) == 6) {
196 struct ip6_hdr *inner_ip6 = mtod(m, struct ip6_hdr *);
197 iphlen = sizeof(struct ip6_hdr);
198 proto = inner_ip6->ip6_nxt;
199 }
200
201 if (proto == IPPROTO_TCP) {
202 if ((int)(iphlen + sizeof(th)) <= m->m_pkthdr.len) {
203 m_copydata(m, iphlen, sizeof(th), (u_int8_t *)&th);
204 }
205
206 proto_len = m->m_pkthdr.len - iphlen - (th.th_off << 2);
207 MPKL_ESP_INPUT_TCP(esp_mpkl_log_object,
208 ntohl(spi), seq,
209 ntohs(th.th_sport), ntohs(th.th_dport),
210 ntohl(th.th_seq), proto_len);
211 }
212 }
213 }
214
215 void
216 esp4_input(struct mbuf *m, int off)
217 {
218 (void)esp4_input_extended(m, off, NULL);
219 }
220
221 struct mbuf *
222 esp4_input_extended(struct mbuf *m, int off, ifnet_t interface)
223 {
224 struct ip *ip;
225 #if INET6
226 struct ip6_hdr *ip6;
227 #endif /* INET6 */
228 struct esp *esp;
229 struct esptail esptail;
230 u_int32_t spi;
231 u_int32_t seq;
232 struct secasvar *sav = NULL;
233 size_t taillen;
234 u_int16_t nxt;
235 const struct esp_algorithm *algo;
236 int ivlen;
237 size_t hlen;
238 size_t esplen;
239 sa_family_t ifamily;
240 struct mbuf *out_m = NULL;
241 mbuf_traffic_class_t traffic_class = 0;
242
243 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_START, 0, 0, 0, 0, 0);
244 /* sanity check for alignment. */
245 if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
246 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
247 "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
248 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
249 goto bad;
250 }
251
252 if (m->m_len < off + ESPMAXLEN) {
253 m = m_pullup(m, off + ESPMAXLEN);
254 if (!m) {
255 ipseclog((LOG_DEBUG,
256 "IPv4 ESP input: can't pullup in esp4_input\n"));
257 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
258 goto bad;
259 }
260 }
261
262 m->m_pkthdr.csum_flags &= ~CSUM_RX_FLAGS;
263
264 /* Expect 32-bit aligned data pointer on strict-align platforms */
265 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
266
267 ip = mtod(m, struct ip *);
268 // expect udp-encap and esp packets only
269 if (ip->ip_p != IPPROTO_ESP &&
270 !(ip->ip_p == IPPROTO_UDP && off >= sizeof(struct udphdr))) {
271 ipseclog((LOG_DEBUG,
272 "IPv4 ESP input: invalid protocol type\n"));
273 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
274 goto bad;
275 }
276 esp = (struct esp *)(void *)(((u_int8_t *)ip) + off);
277 #ifdef _IP_VHL
278 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
279 #else
280 hlen = ip->ip_hl << 2;
281 #endif
282
283 /* find the sassoc. */
284 spi = esp->esp_spi;
285
286 if ((sav = key_allocsa_extended(AF_INET,
287 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
288 IPPROTO_ESP, spi, interface)) == 0) {
289 ipseclog((LOG_WARNING,
290 "IPv4 ESP input: no key association found for spi %u (0x%08x)\n",
291 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
292 IPSEC_STAT_INCREMENT(ipsecstat.in_nosa);
293 goto bad;
294 }
295 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
296 printf("DP esp4_input called to allocate SA:0x%llx\n",
297 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
298 if (sav->state != SADB_SASTATE_MATURE
299 && sav->state != SADB_SASTATE_DYING) {
300 ipseclog((LOG_DEBUG,
301 "IPv4 ESP input: non-mature/dying SA found for spi %u (0x%08x)\n",
302 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
303 IPSEC_STAT_INCREMENT(ipsecstat.in_badspi);
304 goto bad;
305 }
306 algo = esp_algorithm_lookup(sav->alg_enc);
307 if (!algo) {
308 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
309 "unsupported encryption algorithm for spi %u (0x%08x)\n",
310 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
311 IPSEC_STAT_INCREMENT(ipsecstat.in_badspi);
312 goto bad;
313 }
314
315 /* check if we have proper ivlen information */
316 ivlen = sav->ivlen;
317 if (ivlen < 0) {
318 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
319 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
320 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
321 goto bad;
322 }
323
324 seq = ntohl(((struct newesp *)esp)->esp_seq);
325
326 if ((sav->flags2 & SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) ==
327 SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) {
328 u_int8_t dscp = ip->ip_tos >> IPTOS_DSCP_SHIFT;
329 traffic_class = rfc4594_dscp_to_tc(dscp);
330 }
331
332 /* Save ICV from packet for verification later */
333 size_t siz = 0;
334 unsigned char saved_icv[AH_MAXSUMSIZE];
335 if (algo->finalizedecrypt) {
336 siz = algo->icvlen;
337 m_copydata(m, m->m_pkthdr.len - siz, siz, (caddr_t) saved_icv);
338 goto delay_icv;
339 }
340
341 if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL &&
342 (sav->alg_auth && sav->key_auth))) {
343 goto noreplaycheck;
344 }
345
346 if (sav->alg_auth == SADB_X_AALG_NULL ||
347 sav->alg_auth == SADB_AALG_NONE) {
348 goto noreplaycheck;
349 }
350
351 /*
352 * check for sequence number.
353 */
354 if (ipsec_chkreplay(seq, sav, traffic_class)) {
355 ; /*okey*/
356 } else {
357 IPSEC_STAT_INCREMENT(ipsecstat.in_espreplay);
358 ipseclog((LOG_WARNING,
359 "replay packet in IPv4 ESP input: %s %s\n",
360 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
361 goto bad;
362 }
363
364 /* check ICV */
365 {
366 u_char sum0[AH_MAXSUMSIZE] __attribute__((aligned(4)));
367 u_char sum[AH_MAXSUMSIZE] __attribute__((aligned(4)));
368 const struct ah_algorithm *sumalgo;
369
370 sumalgo = ah_algorithm_lookup(sav->alg_auth);
371 if (!sumalgo) {
372 goto noreplaycheck;
373 }
374 siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
375 if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
376 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
377 goto bad;
378 }
379 if (AH_MAXSUMSIZE < siz) {
380 ipseclog((LOG_DEBUG,
381 "internal error: AH_MAXSUMSIZE must be larger than %u\n",
382 (u_int32_t)siz));
383 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
384 goto bad;
385 }
386
387 m_copydata(m, m->m_pkthdr.len - siz, siz, (caddr_t) &sum0[0]);
388
389 if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
390 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
391 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
392 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthfail);
393 goto bad;
394 }
395
396 if (cc_cmp_safe(siz, sum0, sum)) {
397 ipseclog((LOG_WARNING, "cc_cmp fail in IPv4 ESP input: %s %s\n",
398 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
399 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthfail);
400 goto bad;
401 }
402
403 delay_icv:
404
405 /* strip off the authentication data */
406 m_adj(m, -siz);
407 ip = mtod(m, struct ip *);
408 #ifdef IPLEN_FLIPPED
409 ip->ip_len = ip->ip_len - siz;
410 #else
411 ip->ip_len = htons(ntohs(ip->ip_len) - siz);
412 #endif
413 m->m_flags |= M_AUTHIPDGM;
414 IPSEC_STAT_INCREMENT(ipsecstat.in_espauthsucc);
415 }
416
417 /*
418 * update sequence number.
419 */
420 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL) {
421 if (ipsec_updatereplay(seq, sav, traffic_class)) {
422 IPSEC_STAT_INCREMENT(ipsecstat.in_espreplay);
423 goto bad;
424 }
425 }
426
427 noreplaycheck:
428
429 /* process main esp header. */
430 if (sav->flags & SADB_X_EXT_OLD) {
431 /* RFC 1827 */
432 esplen = sizeof(struct esp);
433 } else {
434 /* RFC 2406 */
435 if (sav->flags & SADB_X_EXT_DERIV) {
436 esplen = sizeof(struct esp);
437 } else {
438 esplen = sizeof(struct newesp);
439 }
440 }
441
442 if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
443 ipseclog((LOG_WARNING,
444 "IPv4 ESP input: packet too short\n"));
445 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
446 goto bad;
447 }
448
449 if (m->m_len < off + esplen + ivlen) {
450 m = m_pullup(m, off + esplen + ivlen);
451 if (!m) {
452 ipseclog((LOG_DEBUG,
453 "IPv4 ESP input: can't pullup in esp4_input\n"));
454 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
455 goto bad;
456 }
457 }
458
459 /*
460 * pre-compute and cache intermediate key
461 */
462 if (esp_schedule(algo, sav) != 0) {
463 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
464 goto bad;
465 }
466
467 /*
468 * decrypt the packet.
469 */
470 if (!algo->decrypt) {
471 panic("internal error: no decrypt function");
472 }
473 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_START, 0, 0, 0, 0, 0);
474 if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
475 /* m is already freed */
476 m = NULL;
477 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
478 ipsec_logsastr(sav)));
479 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
480 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 1, 0, 0, 0, 0);
481 goto bad;
482 }
483 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 2, 0, 0, 0, 0);
484 IPSEC_STAT_INCREMENT(ipsecstat.in_esphist[sav->alg_enc]);
485
486 m->m_flags |= M_DECRYPTED;
487
488 if (algo->finalizedecrypt) {
489 if ((*algo->finalizedecrypt)(sav, saved_icv, algo->icvlen)) {
490 ipseclog((LOG_ERR, "esp4 packet decryption ICV failure\n"));
491 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
492 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 1, 0, 0, 0, 0);
493 goto bad;
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, -taillen);
516 ip = mtod(m, struct ip *);
517 #ifdef IPLEN_FLIPPED
518 ip->ip_len = ip->ip_len - 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 }
533
534 // check the UDP encap header to detect changes in the source port, and then strip the header
535 off -= sizeof(struct udphdr); // off no longer includes the udphdr's size
536 // if peer is behind nat and this is the latest esp packet
537 if ((sav->flags & SADB_X_EXT_NATT_DETECTED_PEER) != 0 &&
538 (sav->flags & SADB_X_EXT_OLD) == 0 &&
539 seq && sav->replay[traffic_class] &&
540 seq >= sav->replay[traffic_class]->lastseq) {
541 struct udphdr *encap_uh = (__typeof__(encap_uh))(void *)((caddr_t)ip + off);
542 if (encap_uh->uh_sport &&
543 ntohs(encap_uh->uh_sport) != sav->remote_ike_port) {
544 sav->remote_ike_port = ntohs(encap_uh->uh_sport);
545 }
546 }
547 ip = esp4_input_strip_udp_encap(m, off);
548 esp = (struct esp *)(void *)(((u_int8_t *)ip) + off);
549 }
550
551 /* was it transmitted over the IPsec tunnel SA? */
552 if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav, &ifamily)) {
553 ifaddr_t ifa;
554 struct sockaddr_storage addr;
555
556 /*
557 * strip off all the headers that precedes ESP header.
558 * IP4 xx ESP IP4' payload -> IP4' payload
559 *
560 * XXX more sanity checks
561 * XXX relationship with gif?
562 */
563 u_int8_t tos, otos;
564 int sum;
565
566 tos = ip->ip_tos;
567 m_adj(m, off + esplen + ivlen);
568 if (ifamily == AF_INET) {
569 struct sockaddr_in *ipaddr;
570
571 if (m->m_len < sizeof(*ip)) {
572 m = m_pullup(m, sizeof(*ip));
573 if (!m) {
574 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
575 goto bad;
576 }
577 }
578 ip = mtod(m, struct ip *);
579 /* ECN consideration. */
580
581 otos = ip->ip_tos;
582 if (ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos) == 0) {
583 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
584 goto bad;
585 }
586
587 if (otos != ip->ip_tos) {
588 sum = ~ntohs(ip->ip_sum) & 0xffff;
589 sum += (~otos & 0xffff) + ip->ip_tos;
590 sum = (sum >> 16) + (sum & 0xffff);
591 sum += (sum >> 16); /* add carry */
592 ip->ip_sum = htons(~sum & 0xffff);
593 }
594
595 if (!key_checktunnelsanity(sav, AF_INET,
596 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
597 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
598 "in ESP input: %s %s\n",
599 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
600 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
601 goto bad;
602 }
603
604 bzero(&addr, sizeof(addr));
605 ipaddr = (__typeof__(ipaddr)) & addr;
606 ipaddr->sin_family = AF_INET;
607 ipaddr->sin_len = sizeof(*ipaddr);
608 ipaddr->sin_addr = ip->ip_dst;
609 #if INET6
610 } else if (ifamily == AF_INET6) {
611 struct sockaddr_in6 *ip6addr;
612
613 /*
614 * m_pullup is prohibited in KAME IPv6 input processing
615 * but there's no other way!
616 */
617 if (m->m_len < sizeof(*ip6)) {
618 m = m_pullup(m, sizeof(*ip6));
619 if (!m) {
620 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
621 goto bad;
622 }
623 }
624
625 /*
626 * Expect 32-bit aligned data pointer on strict-align
627 * platforms.
628 */
629 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
630
631 ip6 = mtod(m, struct ip6_hdr *);
632
633 /* ECN consideration. */
634 if (ip64_ecn_egress(ip4_ipsec_ecn, &tos, &ip6->ip6_flow) == 0) {
635 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
636 goto bad;
637 }
638
639 if (!key_checktunnelsanity(sav, AF_INET6,
640 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
641 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
642 "in ESP input: %s %s\n",
643 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
644 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
645 goto bad;
646 }
647
648 bzero(&addr, sizeof(addr));
649 ip6addr = (__typeof__(ip6addr)) & addr;
650 ip6addr->sin6_family = AF_INET6;
651 ip6addr->sin6_len = sizeof(*ip6addr);
652 ip6addr->sin6_addr = ip6->ip6_dst;
653 #endif /* INET6 */
654 } else {
655 ipseclog((LOG_ERR, "ipsec tunnel unsupported address family "
656 "in ESP input\n"));
657 goto bad;
658 }
659
660 key_sa_recordxfer(sav, m);
661 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
662 ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
663 IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
664 goto bad;
665 }
666
667 // update the receiving interface address based on the inner address
668 ifa = ifa_ifwithaddr((struct sockaddr *)&addr);
669 if (ifa) {
670 m->m_pkthdr.rcvif = ifa->ifa_ifp;
671 IFA_REMREF(ifa);
672 }
673
674 /* Clear the csum flags, they can't be valid for the inner headers */
675 m->m_pkthdr.csum_flags = 0;
676
677 // Input via IPsec interface
678 lck_mtx_lock(sadb_mutex);
679 ifnet_t ipsec_if = sav->sah->ipsec_if;
680 if (ipsec_if != NULL) {
681 // If an interface is found, add a reference count before dropping the lock
682 ifnet_reference(ipsec_if);
683 }
684 lck_mtx_unlock(sadb_mutex);
685 if (ipsec_if != NULL) {
686 esp_input_log(m, sav, spi, seq);
687 ipsec_save_wake_packet(m, ntohl(spi), seq);
688
689 // Return mbuf
690 if (interface != NULL &&
691 interface == ipsec_if) {
692 out_m = m;
693 ifnet_release(ipsec_if);
694 goto done;
695 }
696
697 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
698 ifnet_release(ipsec_if);
699
700 if (inject_error == 0) {
701 m = NULL;
702 goto done;
703 } else {
704 goto bad;
705 }
706 }
707
708 if (proto_input(ifamily == AF_INET ? PF_INET : PF_INET6, m) != 0) {
709 goto bad;
710 }
711
712 nxt = IPPROTO_DONE;
713 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_END, 2, 0, 0, 0, 0);
714 } else {
715 /*
716 * strip off ESP header and IV.
717 * even in m_pulldown case, we need to strip off ESP so that
718 * we can always compute checksum for AH correctly.
719 */
720 size_t stripsiz;
721
722 stripsiz = esplen + ivlen;
723
724 ip = mtod(m, struct ip *);
725 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
726 m->m_data += stripsiz;
727 m->m_len -= stripsiz;
728 m->m_pkthdr.len -= stripsiz;
729
730 ip = mtod(m, struct ip *);
731 #ifdef IPLEN_FLIPPED
732 ip->ip_len = ip->ip_len - stripsiz;
733 #else
734 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
735 #endif
736 ip->ip_p = nxt;
737
738 key_sa_recordxfer(sav, m);
739 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
740 IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
741 goto bad;
742 }
743
744 /*
745 * Set the csum valid flag, if we authenticated the
746 * packet, the payload shouldn't be corrupt unless
747 * it was corrupted before being signed on the other
748 * side.
749 */
750 if (nxt == IPPROTO_TCP || nxt == IPPROTO_UDP) {
751 m->m_pkthdr.csum_flags = CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
752 m->m_pkthdr.csum_data = 0xFFFF;
753 _CASSERT(offsetof(struct pkthdr, csum_data) == offsetof(struct pkthdr, csum_rx_val));
754 }
755
756 if (nxt != IPPROTO_DONE) {
757 if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
758 ipsec4_in_reject(m, NULL)) {
759 IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
760 goto bad;
761 }
762 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_END, 3, 0, 0, 0, 0);
763
764 /* translate encapsulated UDP port ? */
765 if ((sav->flags & SADB_X_EXT_NATT_MULTIPLEUSERS) != 0) {
766 struct udphdr *udp;
767
768 if (nxt != IPPROTO_UDP) { /* not UPD packet - drop it */
769 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
770 goto bad;
771 }
772
773 if (m->m_len < off + sizeof(struct udphdr)) {
774 m = m_pullup(m, off + sizeof(struct udphdr));
775 if (!m) {
776 ipseclog((LOG_DEBUG,
777 "IPv4 ESP input: can't pullup UDP header in esp4_input\n"));
778 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
779 goto bad;
780 }
781 ip = mtod(m, struct ip *);
782 }
783 udp = (struct udphdr *)(void *)(((u_int8_t *)ip) + off);
784
785 lck_mtx_lock(sadb_mutex);
786 if (sav->natt_encapsulated_src_port == 0) {
787 sav->natt_encapsulated_src_port = udp->uh_sport;
788 } else if (sav->natt_encapsulated_src_port != udp->uh_sport) { /* something wrong */
789 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
790 lck_mtx_unlock(sadb_mutex);
791 goto bad;
792 }
793 lck_mtx_unlock(sadb_mutex);
794 udp->uh_sport = htons(sav->remote_ike_port);
795 udp->uh_sum = 0;
796 }
797
798 DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
799 struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
800 struct ip *, ip, struct ip6_hdr *, NULL);
801
802 // Input via IPsec interface legacy path
803 lck_mtx_lock(sadb_mutex);
804 ifnet_t ipsec_if = sav->sah->ipsec_if;
805 if (ipsec_if != NULL) {
806 // If an interface is found, add a reference count before dropping the lock
807 ifnet_reference(ipsec_if);
808 }
809 lck_mtx_unlock(sadb_mutex);
810 if (ipsec_if != NULL) {
811 int mlen;
812 if ((mlen = m_length2(m, NULL)) < hlen) {
813 ipseclog((LOG_DEBUG,
814 "IPv4 ESP input: decrypted packet too short %d < %zu\n",
815 mlen, hlen));
816 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
817 ifnet_release(ipsec_if);
818 goto bad;
819 }
820 ip->ip_len = htons(ip->ip_len + hlen);
821 ip->ip_off = htons(ip->ip_off);
822 ip->ip_sum = 0;
823 ip->ip_sum = ip_cksum_hdr_in(m, hlen);
824
825 esp_input_log(m, sav, spi, seq);
826 ipsec_save_wake_packet(m, ntohl(spi), seq);
827
828 // Return mbuf
829 if (interface != NULL &&
830 interface == ipsec_if) {
831 out_m = m;
832 ifnet_release(ipsec_if);
833 goto done;
834 }
835
836 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
837 ifnet_release(ipsec_if);
838
839 if (inject_error == 0) {
840 m = NULL;
841 goto done;
842 } else {
843 goto bad;
844 }
845 }
846
847 ip_proto_dispatch_in(m, off, nxt, 0);
848 } else {
849 m_freem(m);
850 }
851 m = NULL;
852 }
853
854 done:
855 if (sav) {
856 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
857 printf("DP esp4_input call free SA:0x%llx\n",
858 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
859 key_freesav(sav, KEY_SADB_UNLOCKED);
860 }
861 IPSEC_STAT_INCREMENT(ipsecstat.in_success);
862 return out_m;
863 bad:
864 if (sav) {
865 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
866 printf("DP esp4_input call free SA:0x%llx\n",
867 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
868 key_freesav(sav, KEY_SADB_UNLOCKED);
869 }
870 if (m) {
871 m_freem(m);
872 }
873 KERNEL_DEBUG(DBG_FNC_ESPIN | DBG_FUNC_END, 4, 0, 0, 0, 0);
874 return out_m;
875 }
876 #endif /* INET */
877
878 #if INET6
879
880 int
881 esp6_input(struct mbuf **mp, int *offp, int proto)
882 {
883 return esp6_input_extended(mp, offp, proto, NULL);
884 }
885
886 int
887 esp6_input_extended(struct mbuf **mp, int *offp, int proto, ifnet_t interface)
888 {
889 #pragma unused(proto)
890 struct mbuf *m = *mp;
891 int off = *offp;
892 struct ip *ip;
893 struct ip6_hdr *ip6;
894 struct esp *esp;
895 struct esptail esptail;
896 u_int32_t spi;
897 u_int32_t seq;
898 struct secasvar *sav = NULL;
899 size_t taillen;
900 u_int16_t nxt;
901 char *nproto;
902 const struct esp_algorithm *algo;
903 int ivlen;
904 size_t esplen;
905 sa_family_t ifamily;
906 mbuf_traffic_class_t traffic_class = 0;
907
908 /* sanity check for alignment. */
909 if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
910 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
911 "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
912 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
913 goto bad;
914 }
915
916 #ifndef PULLDOWN_TEST
917 IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, {return IPPROTO_DONE;});
918 esp = (struct esp *)(void *)(mtod(m, caddr_t) + off);
919 #else
920 IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
921 if (esp == NULL) {
922 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
923 return IPPROTO_DONE;
924 }
925 #endif
926 m->m_pkthdr.csum_flags &= ~CSUM_RX_FLAGS;
927
928 /* Expect 32-bit data aligned pointer on strict-align platforms */
929 MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
930
931 ip6 = mtod(m, struct ip6_hdr *);
932
933 if (ntohs(ip6->ip6_plen) == 0) {
934 ipseclog((LOG_ERR, "IPv6 ESP input: "
935 "ESP with IPv6 jumbogram is not supported.\n"));
936 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
937 goto bad;
938 }
939
940 nproto = ip6_get_prevhdr(m, off);
941 if (nproto == NULL || (*nproto != IPPROTO_ESP &&
942 !(*nproto == IPPROTO_UDP && off >= sizeof(struct udphdr)))) {
943 ipseclog((LOG_DEBUG, "IPv6 ESP input: invalid protocol type\n"));
944 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
945 goto bad;
946 }
947
948 /* find the sassoc. */
949 spi = esp->esp_spi;
950
951 if ((sav = key_allocsa_extended(AF_INET6,
952 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
953 IPPROTO_ESP, spi, interface)) == 0) {
954 ipseclog((LOG_WARNING,
955 "IPv6 ESP input: no key association found for spi %u (0x%08x) seq %u"
956 " src %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
957 " dst %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x if %s\n",
958 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi), ntohl(((struct newesp *)esp)->esp_seq),
959 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[0]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[1]),
960 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[2]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[3]),
961 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[4]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[5]),
962 ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[6]), ntohs(ip6->ip6_src.__u6_addr.__u6_addr16[7]),
963 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[0]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[1]),
964 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[2]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[3]),
965 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[4]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[5]),
966 ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[6]), ntohs(ip6->ip6_dst.__u6_addr.__u6_addr16[7]),
967 ((interface != NULL) ? if_name(interface) : "NONE")));
968 IPSEC_STAT_INCREMENT(ipsec6stat.in_nosa);
969 goto bad;
970 }
971 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
972 printf("DP esp6_input called to allocate SA:0x%llx\n",
973 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
974 if (sav->state != SADB_SASTATE_MATURE
975 && sav->state != SADB_SASTATE_DYING) {
976 ipseclog((LOG_DEBUG,
977 "IPv6 ESP input: non-mature/dying SA found for spi %u (0x%08x)\n",
978 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
979 IPSEC_STAT_INCREMENT(ipsec6stat.in_badspi);
980 goto bad;
981 }
982 algo = esp_algorithm_lookup(sav->alg_enc);
983 if (!algo) {
984 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
985 "unsupported encryption algorithm for spi %u (0x%08x)\n",
986 (u_int32_t)ntohl(spi), (u_int32_t)ntohl(spi)));
987 IPSEC_STAT_INCREMENT(ipsec6stat.in_badspi);
988 goto bad;
989 }
990
991 /* check if we have proper ivlen information */
992 ivlen = sav->ivlen;
993 if (ivlen < 0) {
994 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
995 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
996 IPSEC_STAT_INCREMENT(ipsec6stat.in_badspi);
997 goto bad;
998 }
999
1000 seq = ntohl(((struct newesp *)esp)->esp_seq);
1001
1002 if ((sav->flags2 & SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) ==
1003 SADB_X_EXT_SA2_SEQ_PER_TRAFFIC_CLASS) {
1004 u_int8_t dscp = (ntohl(ip6->ip6_flow) & IP6FLOW_DSCP_MASK) >> IP6FLOW_DSCP_SHIFT;
1005 traffic_class = rfc4594_dscp_to_tc(dscp);
1006 }
1007
1008 /* Save ICV from packet for verification later */
1009 size_t siz = 0;
1010 unsigned char saved_icv[AH_MAXSUMSIZE];
1011 if (algo->finalizedecrypt) {
1012 siz = algo->icvlen;
1013 m_copydata(m, m->m_pkthdr.len - siz, siz, (caddr_t) saved_icv);
1014 goto delay_icv;
1015 }
1016
1017 if (!((sav->flags & SADB_X_EXT_OLD) == 0 &&
1018 sav->replay[traffic_class] != NULL &&
1019 (sav->alg_auth && sav->key_auth))) {
1020 goto noreplaycheck;
1021 }
1022
1023 if (sav->alg_auth == SADB_X_AALG_NULL ||
1024 sav->alg_auth == SADB_AALG_NONE) {
1025 goto noreplaycheck;
1026 }
1027
1028 /*
1029 * check for sequence number.
1030 */
1031 if (ipsec_chkreplay(seq, sav, traffic_class)) {
1032 ; /*okey*/
1033 } else {
1034 IPSEC_STAT_INCREMENT(ipsec6stat.in_espreplay);
1035 ipseclog((LOG_WARNING,
1036 "replay packet in IPv6 ESP input: %s %s\n",
1037 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1038 goto bad;
1039 }
1040
1041 /* check ICV */
1042 {
1043 u_char sum0[AH_MAXSUMSIZE] __attribute__((aligned(4)));
1044 u_char sum[AH_MAXSUMSIZE] __attribute__((aligned(4)));
1045 const struct ah_algorithm *sumalgo;
1046
1047 sumalgo = ah_algorithm_lookup(sav->alg_auth);
1048 if (!sumalgo) {
1049 goto noreplaycheck;
1050 }
1051 siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
1052 if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
1053 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1054 goto bad;
1055 }
1056 if (AH_MAXSUMSIZE < siz) {
1057 ipseclog((LOG_DEBUG,
1058 "internal error: AH_MAXSUMSIZE must be larger than %u\n",
1059 (u_int32_t)siz));
1060 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1061 goto bad;
1062 }
1063
1064 m_copydata(m, m->m_pkthdr.len - siz, siz, (caddr_t) &sum0[0]);
1065
1066 if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
1067 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
1068 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1069 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthfail);
1070 goto bad;
1071 }
1072
1073 if (cc_cmp_safe(siz, sum0, sum)) {
1074 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
1075 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1076 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthfail);
1077 goto bad;
1078 }
1079
1080 delay_icv:
1081
1082 /* strip off the authentication data */
1083 m_adj(m, -siz);
1084 ip6 = mtod(m, struct ip6_hdr *);
1085 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
1086
1087 m->m_flags |= M_AUTHIPDGM;
1088 IPSEC_STAT_INCREMENT(ipsec6stat.in_espauthsucc);
1089 }
1090
1091 /*
1092 * update sequence number.
1093 */
1094 if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay[traffic_class] != NULL) {
1095 if (ipsec_updatereplay(seq, sav, traffic_class)) {
1096 IPSEC_STAT_INCREMENT(ipsec6stat.in_espreplay);
1097 goto bad;
1098 }
1099 }
1100
1101 noreplaycheck:
1102
1103 /* process main esp header. */
1104 if (sav->flags & SADB_X_EXT_OLD) {
1105 /* RFC 1827 */
1106 esplen = sizeof(struct esp);
1107 } else {
1108 /* RFC 2406 */
1109 if (sav->flags & SADB_X_EXT_DERIV) {
1110 esplen = sizeof(struct esp);
1111 } else {
1112 esplen = sizeof(struct newesp);
1113 }
1114 }
1115
1116 if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
1117 ipseclog((LOG_WARNING,
1118 "IPv6 ESP input: packet too short\n"));
1119 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1120 goto bad;
1121 }
1122
1123 #ifndef PULLDOWN_TEST
1124 IP6_EXTHDR_CHECK(m, off, esplen + ivlen, return IPPROTO_DONE); /*XXX*/
1125 #else
1126 IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
1127 if (esp == NULL) {
1128 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1129 m = NULL;
1130 goto bad;
1131 }
1132 #endif
1133 ip6 = mtod(m, struct ip6_hdr *); /*set it again just in case*/
1134
1135 /*
1136 * pre-compute and cache intermediate key
1137 */
1138 if (esp_schedule(algo, sav) != 0) {
1139 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1140 goto bad;
1141 }
1142
1143 /*
1144 * decrypt the packet.
1145 */
1146 if (!algo->decrypt) {
1147 panic("internal error: no decrypt function");
1148 }
1149 if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
1150 /* m is already freed */
1151 m = NULL;
1152 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
1153 ipsec_logsastr(sav)));
1154 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1155 goto bad;
1156 }
1157 IPSEC_STAT_INCREMENT(ipsec6stat.in_esphist[sav->alg_enc]);
1158
1159 m->m_flags |= M_DECRYPTED;
1160
1161 if (algo->finalizedecrypt) {
1162 if ((*algo->finalizedecrypt)(sav, saved_icv, algo->icvlen)) {
1163 ipseclog((LOG_ERR, "esp6 packet decryption ICV failure\n"));
1164 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1165 KERNEL_DEBUG(DBG_FNC_DECRYPT | DBG_FUNC_END, 1, 0, 0, 0, 0);
1166 goto bad;
1167 }
1168 }
1169
1170 /*
1171 * find the trailer of the ESP.
1172 */
1173 m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
1174 (caddr_t)&esptail);
1175 nxt = esptail.esp_nxt;
1176 taillen = esptail.esp_padlen + sizeof(esptail);
1177
1178 if (m->m_pkthdr.len < taillen
1179 || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) { /*?*/
1180 ipseclog((LOG_WARNING,
1181 "bad pad length in IPv6 ESP input: %s %s\n",
1182 ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
1183 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1184 goto bad;
1185 }
1186
1187 /* strip off the trailing pad area. */
1188 m_adj(m, -taillen);
1189 ip6 = mtod(m, struct ip6_hdr *);
1190 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
1191
1192 if (*nproto == IPPROTO_UDP) {
1193 // offset includes the outer ip and udp header lengths.
1194 if (m->m_len < off) {
1195 m = m_pullup(m, off);
1196 if (!m) {
1197 ipseclog((LOG_DEBUG,
1198 "IPv6 ESP input: invalid udp encapsulated ESP packet length\n"));
1199 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1200 goto bad;
1201 }
1202 }
1203
1204 // check the UDP encap header to detect changes in the source port, and then strip the header
1205 off -= sizeof(struct udphdr); // off no longer includes the udphdr's size
1206 // if peer is behind nat and this is the latest esp packet
1207 if ((sav->flags & SADB_X_EXT_NATT_DETECTED_PEER) != 0 &&
1208 (sav->flags & SADB_X_EXT_OLD) == 0 &&
1209 seq && sav->replay[traffic_class] &&
1210 seq >= sav->replay[traffic_class]->lastseq) {
1211 struct udphdr *encap_uh = (__typeof__(encap_uh))(void *)((caddr_t)ip6 + off);
1212 if (encap_uh->uh_sport &&
1213 ntohs(encap_uh->uh_sport) != sav->remote_ike_port) {
1214 sav->remote_ike_port = ntohs(encap_uh->uh_sport);
1215 }
1216 }
1217 ip6 = esp6_input_strip_udp_encap(m, off);
1218 esp = (struct esp *)(void *)(((u_int8_t *)ip6) + off);
1219 }
1220
1221
1222 /* was it transmitted over the IPsec tunnel SA? */
1223 if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav, &ifamily)) {
1224 ifaddr_t ifa;
1225 struct sockaddr_storage addr;
1226
1227 /*
1228 * strip off all the headers that precedes ESP header.
1229 * IP6 xx ESP IP6' payload -> IP6' payload
1230 *
1231 * XXX more sanity checks
1232 * XXX relationship with gif?
1233 */
1234 u_int32_t flowinfo; /*net endian*/
1235 flowinfo = ip6->ip6_flow;
1236 m_adj(m, off + esplen + ivlen);
1237 if (ifamily == AF_INET6) {
1238 struct sockaddr_in6 *ip6addr;
1239
1240 if (m->m_len < sizeof(*ip6)) {
1241 #ifndef PULLDOWN_TEST
1242 /*
1243 * m_pullup is prohibited in KAME IPv6 input processing
1244 * but there's no other way!
1245 */
1246 #else
1247 /* okay to pullup in m_pulldown style */
1248 #endif
1249 m = m_pullup(m, sizeof(*ip6));
1250 if (!m) {
1251 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1252 goto bad;
1253 }
1254 }
1255 ip6 = mtod(m, struct ip6_hdr *);
1256 /* ECN consideration. */
1257 if (ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow) == 0) {
1258 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1259 goto bad;
1260 }
1261 if (!key_checktunnelsanity(sav, AF_INET6,
1262 (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
1263 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
1264 "in IPv6 ESP input: %s %s\n",
1265 ipsec6_logpacketstr(ip6, spi),
1266 ipsec_logsastr(sav)));
1267 IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1268 goto bad;
1269 }
1270
1271 bzero(&addr, sizeof(addr));
1272 ip6addr = (__typeof__(ip6addr)) & addr;
1273 ip6addr->sin6_family = AF_INET6;
1274 ip6addr->sin6_len = sizeof(*ip6addr);
1275 ip6addr->sin6_addr = ip6->ip6_dst;
1276 } else if (ifamily == AF_INET) {
1277 struct sockaddr_in *ipaddr;
1278
1279 if (m->m_len < sizeof(*ip)) {
1280 m = m_pullup(m, sizeof(*ip));
1281 if (!m) {
1282 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1283 goto bad;
1284 }
1285 }
1286
1287 u_int8_t otos;
1288 int sum;
1289
1290 ip = mtod(m, struct ip *);
1291 otos = ip->ip_tos;
1292 /* ECN consideration. */
1293 if (ip46_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip->ip_tos) == 0) {
1294 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1295 goto bad;
1296 }
1297
1298 if (otos != ip->ip_tos) {
1299 sum = ~ntohs(ip->ip_sum) & 0xffff;
1300 sum += (~otos & 0xffff) + ip->ip_tos;
1301 sum = (sum >> 16) + (sum & 0xffff);
1302 sum += (sum >> 16); /* add carry */
1303 ip->ip_sum = htons(~sum & 0xffff);
1304 }
1305
1306 if (!key_checktunnelsanity(sav, AF_INET,
1307 (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
1308 ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
1309 "in ESP input: %s %s\n",
1310 ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
1311 IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1312 goto bad;
1313 }
1314
1315 bzero(&addr, sizeof(addr));
1316 ipaddr = (__typeof__(ipaddr)) & addr;
1317 ipaddr->sin_family = AF_INET;
1318 ipaddr->sin_len = sizeof(*ipaddr);
1319 ipaddr->sin_addr = ip->ip_dst;
1320 }
1321
1322 key_sa_recordxfer(sav, m);
1323 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
1324 ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
1325 IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
1326 goto bad;
1327 }
1328
1329 // update the receiving interface address based on the inner address
1330 ifa = ifa_ifwithaddr((struct sockaddr *)&addr);
1331 if (ifa) {
1332 m->m_pkthdr.rcvif = ifa->ifa_ifp;
1333 IFA_REMREF(ifa);
1334 }
1335
1336 // Input via IPsec interface
1337 lck_mtx_lock(sadb_mutex);
1338 ifnet_t ipsec_if = sav->sah->ipsec_if;
1339 if (ipsec_if != NULL) {
1340 // If an interface is found, add a reference count before dropping the lock
1341 ifnet_reference(ipsec_if);
1342 }
1343 lck_mtx_unlock(sadb_mutex);
1344 if (ipsec_if != NULL) {
1345 esp_input_log(m, sav, spi, seq);
1346 ipsec_save_wake_packet(m, ntohl(spi), seq);
1347
1348 // Return mbuf
1349 if (interface != NULL &&
1350 interface == ipsec_if) {
1351 ifnet_release(ipsec_if);
1352 goto done;
1353 }
1354
1355 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
1356 ifnet_release(ipsec_if);
1357
1358 if (inject_error == 0) {
1359 m = NULL;
1360 nxt = IPPROTO_DONE;
1361 goto done;
1362 } else {
1363 goto bad;
1364 }
1365 }
1366
1367 if (proto_input(ifamily == AF_INET ? PF_INET : PF_INET6, m) != 0) {
1368 goto bad;
1369 }
1370 nxt = IPPROTO_DONE;
1371 } else {
1372 /*
1373 * strip off ESP header and IV.
1374 * even in m_pulldown case, we need to strip off ESP so that
1375 * we can always compute checksum for AH correctly.
1376 */
1377 size_t stripsiz;
1378 char *prvnxtp;
1379
1380 /*
1381 * Set the next header field of the previous header correctly.
1382 */
1383 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
1384 *prvnxtp = nxt;
1385
1386 stripsiz = esplen + ivlen;
1387
1388 ip6 = mtod(m, struct ip6_hdr *);
1389 if (m->m_len >= stripsiz + off) {
1390 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
1391 m->m_data += stripsiz;
1392 m->m_len -= stripsiz;
1393 m->m_pkthdr.len -= stripsiz;
1394 } else {
1395 /*
1396 * this comes with no copy if the boundary is on
1397 * cluster
1398 */
1399 struct mbuf *n;
1400
1401 n = m_split(m, off, M_DONTWAIT);
1402 if (n == NULL) {
1403 /* m is retained by m_split */
1404 goto bad;
1405 }
1406 m_adj(n, stripsiz);
1407 /* m_cat does not update m_pkthdr.len */
1408 m->m_pkthdr.len += n->m_pkthdr.len;
1409 m_cat(m, n);
1410 }
1411
1412 #ifndef PULLDOWN_TEST
1413 /*
1414 * KAME requires that the packet to be contiguous on the
1415 * mbuf. We need to make that sure.
1416 * this kind of code should be avoided.
1417 * XXX other conditions to avoid running this part?
1418 */
1419 if (m->m_len != m->m_pkthdr.len) {
1420 struct mbuf *n = NULL;
1421 int maxlen;
1422
1423 MGETHDR(n, M_DONTWAIT, MT_HEADER); /* MAC-OK */
1424 maxlen = MHLEN;
1425 if (n) {
1426 M_COPY_PKTHDR(n, m);
1427 }
1428 if (n && m->m_pkthdr.len > maxlen) {
1429 MCLGET(n, M_DONTWAIT);
1430 maxlen = MCLBYTES;
1431 if ((n->m_flags & M_EXT) == 0) {
1432 m_free(n);
1433 n = NULL;
1434 }
1435 }
1436 if (!n) {
1437 printf("esp6_input: mbuf allocation failed\n");
1438 goto bad;
1439 }
1440
1441 if (m->m_pkthdr.len <= maxlen) {
1442 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
1443 n->m_len = m->m_pkthdr.len;
1444 n->m_pkthdr.len = m->m_pkthdr.len;
1445 n->m_next = NULL;
1446 m_freem(m);
1447 } else {
1448 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
1449 n->m_len = maxlen;
1450 n->m_pkthdr.len = m->m_pkthdr.len;
1451 n->m_next = m;
1452 m_adj(m, maxlen);
1453 m->m_flags &= ~M_PKTHDR;
1454 }
1455 m = n;
1456 }
1457 #endif
1458 ip6 = mtod(m, struct ip6_hdr *);
1459 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
1460
1461 key_sa_recordxfer(sav, m);
1462 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
1463 IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
1464 goto bad;
1465 }
1466
1467 /*
1468 * Set the csum valid flag, if we authenticated the
1469 * packet, the payload shouldn't be corrupt unless
1470 * it was corrupted before being signed on the other
1471 * side.
1472 */
1473 if (nxt == IPPROTO_TCP || nxt == IPPROTO_UDP) {
1474 m->m_pkthdr.csum_flags = CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1475 m->m_pkthdr.csum_data = 0xFFFF;
1476 _CASSERT(offsetof(struct pkthdr, csum_data) == offsetof(struct pkthdr, csum_rx_val));
1477 }
1478
1479 // Input via IPsec interface
1480 lck_mtx_lock(sadb_mutex);
1481 ifnet_t ipsec_if = sav->sah->ipsec_if;
1482 if (ipsec_if != NULL) {
1483 // If an interface is found, add a reference count before dropping the lock
1484 ifnet_reference(ipsec_if);
1485 }
1486 lck_mtx_unlock(sadb_mutex);
1487 if (ipsec_if != NULL) {
1488 esp_input_log(m, sav, spi, seq);
1489 ipsec_save_wake_packet(m, ntohl(spi), seq);
1490
1491 // Return mbuf
1492 if (interface != NULL &&
1493 interface == ipsec_if) {
1494 ifnet_release(ipsec_if);
1495 goto done;
1496 }
1497
1498 errno_t inject_error = ipsec_inject_inbound_packet(ipsec_if, m);
1499 ifnet_release(ipsec_if);
1500
1501 if (inject_error == 0) {
1502 m = NULL;
1503 nxt = IPPROTO_DONE;
1504 goto done;
1505 } else {
1506 goto bad;
1507 }
1508 }
1509 }
1510
1511 done:
1512 *offp = off;
1513 *mp = m;
1514 if (sav) {
1515 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1516 printf("DP esp6_input call free SA:0x%llx\n",
1517 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
1518 key_freesav(sav, KEY_SADB_UNLOCKED);
1519 }
1520 IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
1521 return nxt;
1522
1523 bad:
1524 if (sav) {
1525 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1526 printf("DP esp6_input call free SA:0x%llx\n",
1527 (uint64_t)VM_KERNEL_ADDRPERM(sav)));
1528 key_freesav(sav, KEY_SADB_UNLOCKED);
1529 }
1530 if (m) {
1531 m_freem(m);
1532 }
1533 if (interface != NULL) {
1534 *mp = NULL;
1535 }
1536 return IPPROTO_DONE;
1537 }
1538
1539 void
1540 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d, __unused struct ifnet *ifp)
1541 {
1542 const struct newesp *espp;
1543 struct newesp esp;
1544 struct ip6ctlparam *ip6cp = NULL, ip6cp1;
1545 struct secasvar *sav;
1546 struct ip6_hdr *ip6;
1547 struct mbuf *m;
1548 int off = 0;
1549 struct sockaddr_in6 *sa6_src, *sa6_dst;
1550
1551 if (sa->sa_family != AF_INET6 ||
1552 sa->sa_len != sizeof(struct sockaddr_in6)) {
1553 return;
1554 }
1555 if ((unsigned)cmd >= PRC_NCMDS) {
1556 return;
1557 }
1558
1559 /* if the parameter is from icmp6, decode it. */
1560 if (d != NULL) {
1561 ip6cp = (struct ip6ctlparam *)d;
1562 m = ip6cp->ip6c_m;
1563 ip6 = ip6cp->ip6c_ip6;
1564 off = ip6cp->ip6c_off;
1565 } else {
1566 m = NULL;
1567 ip6 = NULL;
1568 }
1569
1570 if (ip6) {
1571 /*
1572 * Notify the error to all possible sockets via pfctlinput2.
1573 * Since the upper layer information (such as protocol type,
1574 * source and destination ports) is embedded in the encrypted
1575 * data and might have been cut, we can't directly call
1576 * an upper layer ctlinput function. However, the pcbnotify
1577 * function will consider source and destination addresses
1578 * as well as the flow info value, and may be able to find
1579 * some PCB that should be notified.
1580 * Although pfctlinput2 will call esp6_ctlinput(), there is
1581 * no possibility of an infinite loop of function calls,
1582 * because we don't pass the inner IPv6 header.
1583 */
1584 bzero(&ip6cp1, sizeof(ip6cp1));
1585 ip6cp1.ip6c_src = ip6cp->ip6c_src;
1586 pfctlinput2(cmd, sa, (void *)&ip6cp1);
1587
1588 /*
1589 * Then go to special cases that need ESP header information.
1590 * XXX: We assume that when ip6 is non NULL,
1591 * M and OFF are valid.
1592 */
1593
1594 /* check if we can safely examine src and dst ports */
1595 if (m->m_pkthdr.len < off + sizeof(esp)) {
1596 return;
1597 }
1598
1599 if (m->m_len < off + sizeof(esp)) {
1600 /*
1601 * this should be rare case,
1602 * so we compromise on this copy...
1603 */
1604 m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
1605 espp = &esp;
1606 } else {
1607 espp = (struct newesp*)(void *)(mtod(m, caddr_t) + off);
1608 }
1609
1610 if (cmd == PRC_MSGSIZE) {
1611 int valid = 0;
1612
1613 /*
1614 * Check to see if we have a valid SA corresponding to
1615 * the address in the ICMP message payload.
1616 */
1617 sa6_src = ip6cp->ip6c_src;
1618 sa6_dst = (struct sockaddr_in6 *)(void *)sa;
1619 sav = key_allocsa(AF_INET6,
1620 (caddr_t)&sa6_src->sin6_addr,
1621 (caddr_t)&sa6_dst->sin6_addr,
1622 IPPROTO_ESP, espp->esp_spi);
1623 if (sav) {
1624 if (sav->state == SADB_SASTATE_MATURE ||
1625 sav->state == SADB_SASTATE_DYING) {
1626 valid++;
1627 }
1628 key_freesav(sav, KEY_SADB_UNLOCKED);
1629 }
1630
1631 /* XXX Further validation? */
1632
1633 /*
1634 * Depending on the value of "valid" and routing table
1635 * size (mtudisc_{hi,lo}wat), we will:
1636 * - recalcurate the new MTU and create the
1637 * corresponding routing entry, or
1638 * - ignore the MTU change notification.
1639 */
1640 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1641 }
1642 } else {
1643 /* we normally notify any pcb here */
1644 }
1645 }
1646 #endif /* INET6 */