1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2015-2019 Yandex LLC 5 * Copyright (c) 2015-2019 Andrey V. Elsukov <ae@FreeBSD.org> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_ipstealth.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/counter.h> 37 #include <sys/errno.h> 38 #include <sys/kernel.h> 39 #include <sys/lock.h> 40 #include <sys/mbuf.h> 41 #include <sys/module.h> 42 #include <sys/rmlock.h> 43 #include <sys/rwlock.h> 44 #include <sys/socket.h> 45 #include <sys/queue.h> 46 47 #include <net/if.h> 48 #include <net/if_var.h> 49 #include <net/if_pflog.h> 50 #include <net/pfil.h> 51 #include <net/netisr.h> 52 #include <net/route.h> 53 #include <net/route/nhop.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_fib.h> 57 #include <netinet/in_var.h> 58 #include <netinet/ip.h> 59 #include <netinet/ip_var.h> 60 #include <netinet/ip_fw.h> 61 #include <netinet/ip6.h> 62 #include <netinet/icmp6.h> 63 #include <netinet/ip_icmp.h> 64 #include <netinet/tcp.h> 65 #include <netinet/udp.h> 66 #include <netinet6/in6_var.h> 67 #include <netinet6/in6_fib.h> 68 #include <netinet6/ip6_var.h> 69 #include <netinet6/ip_fw_nat64.h> 70 71 #include <netpfil/pf/pf.h> 72 #include <netpfil/ipfw/ip_fw_private.h> 73 #include <machine/in_cksum.h> 74 75 #include "ip_fw_nat64.h" 76 #include "nat64_translate.h" 77 78 79 typedef int (*nat64_output_t)(struct ifnet *, struct mbuf *, 80 struct sockaddr *, struct nat64_counters *, void *); 81 typedef int (*nat64_output_one_t)(struct mbuf *, struct nat64_counters *, 82 void *); 83 84 static struct nhop_object *nat64_find_route4(struct sockaddr_in *, 85 struct mbuf *); 86 static struct nhop_object *nat64_find_route6(struct sockaddr_in6 *, 87 struct mbuf *); 88 static int nat64_output_one(struct mbuf *, struct nat64_counters *, void *); 89 static int nat64_output(struct ifnet *, struct mbuf *, struct sockaddr *, 90 struct nat64_counters *, void *); 91 static int nat64_direct_output_one(struct mbuf *, struct nat64_counters *, 92 void *); 93 static int nat64_direct_output(struct ifnet *, struct mbuf *, 94 struct sockaddr *, struct nat64_counters *, void *); 95 96 struct nat64_methods { 97 nat64_output_t output; 98 nat64_output_one_t output_one; 99 }; 100 static const struct nat64_methods nat64_netisr = { 101 .output = nat64_output, 102 .output_one = nat64_output_one 103 }; 104 static const struct nat64_methods nat64_direct = { 105 .output = nat64_direct_output, 106 .output_one = nat64_direct_output_one 107 }; 108 109 /* These variables should be initialized explicitly on module loading */ 110 VNET_DEFINE_STATIC(const struct nat64_methods *, nat64out); 111 VNET_DEFINE_STATIC(const int *, nat64ipstealth); 112 VNET_DEFINE_STATIC(const int *, nat64ip6stealth); 113 #define V_nat64out VNET(nat64out) 114 #define V_nat64ipstealth VNET(nat64ipstealth) 115 #define V_nat64ip6stealth VNET(nat64ip6stealth) 116 117 static const int stealth_on = 1; 118 #ifndef IPSTEALTH 119 static const int stealth_off = 0; 120 #endif 121 122 void 123 nat64_set_output_method(int direct) 124 { 125 126 if (direct != 0) { 127 V_nat64out = &nat64_direct; 128 #ifdef IPSTEALTH 129 /* Honor corresponding variables, if IPSTEALTH is defined */ 130 V_nat64ipstealth = &V_ipstealth; 131 V_nat64ip6stealth = &V_ip6stealth; 132 #else 133 /* otherwise we need to decrement HLIM/TTL for direct case */ 134 V_nat64ipstealth = V_nat64ip6stealth = &stealth_off; 135 #endif 136 } else { 137 V_nat64out = &nat64_netisr; 138 /* Leave TTL/HLIM decrementing to forwarding code */ 139 V_nat64ipstealth = V_nat64ip6stealth = &stealth_on; 140 } 141 } 142 143 int 144 nat64_get_output_method(void) 145 { 146 147 return (V_nat64out == &nat64_direct ? 1: 0); 148 } 149 150 static void 151 nat64_log(struct pfloghdr *logdata, struct mbuf *m, sa_family_t family) 152 { 153 154 logdata->dir = PF_OUT; 155 logdata->af = family; 156 ipfw_bpf_mtap2(logdata, PFLOG_HDRLEN, m); 157 } 158 159 static int 160 nat64_direct_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 161 struct nat64_counters *stats, void *logdata) 162 { 163 int error; 164 165 if (logdata != NULL) 166 nat64_log(logdata, m, dst->sa_family); 167 error = (*ifp->if_output)(ifp, m, dst, NULL); 168 if (error != 0) 169 NAT64STAT_INC(stats, oerrors); 170 return (error); 171 } 172 173 static int 174 nat64_direct_output_one(struct mbuf *m, struct nat64_counters *stats, 175 void *logdata) 176 { 177 struct nhop_object *nh4 = NULL; 178 struct nhop_object *nh6 = NULL; 179 struct sockaddr_in6 dst6; 180 struct sockaddr_in dst4; 181 struct sockaddr *dst; 182 struct ip6_hdr *ip6; 183 struct ip *ip4; 184 struct ifnet *ifp; 185 int error; 186 187 ip4 = mtod(m, struct ip *); 188 error = 0; 189 switch (ip4->ip_v) { 190 case IPVERSION: 191 dst4.sin_addr = ip4->ip_dst; 192 nh4 = nat64_find_route4(&dst4, m); 193 if (nh4 == NULL) { 194 NAT64STAT_INC(stats, noroute4); 195 error = EHOSTUNREACH; 196 } else { 197 ifp = nh4->nh_ifp; 198 dst = (struct sockaddr *)&dst4; 199 } 200 break; 201 case (IPV6_VERSION >> 4): 202 ip6 = mtod(m, struct ip6_hdr *); 203 dst6.sin6_addr = ip6->ip6_dst; 204 nh6 = nat64_find_route6(&dst6, m); 205 if (nh6 == NULL) { 206 NAT64STAT_INC(stats, noroute6); 207 error = EHOSTUNREACH; 208 } else { 209 ifp = nh6->nh_ifp; 210 dst = (struct sockaddr *)&dst6; 211 } 212 break; 213 default: 214 m_freem(m); 215 NAT64STAT_INC(stats, dropped); 216 DPRINTF(DP_DROPS, "dropped due to unknown IP version"); 217 return (EAFNOSUPPORT); 218 } 219 if (error != 0) { 220 m_freem(m); 221 return (EHOSTUNREACH); 222 } 223 if (logdata != NULL) 224 nat64_log(logdata, m, dst->sa_family); 225 error = (*ifp->if_output)(ifp, m, dst, NULL); 226 if (error != 0) 227 NAT64STAT_INC(stats, oerrors); 228 return (error); 229 } 230 231 static int 232 nat64_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 233 struct nat64_counters *stats, void *logdata) 234 { 235 struct ip *ip4; 236 int ret, af; 237 238 ip4 = mtod(m, struct ip *); 239 switch (ip4->ip_v) { 240 case IPVERSION: 241 af = AF_INET; 242 ret = NETISR_IP; 243 break; 244 case (IPV6_VERSION >> 4): 245 af = AF_INET6; 246 ret = NETISR_IPV6; 247 break; 248 default: 249 m_freem(m); 250 NAT64STAT_INC(stats, dropped); 251 DPRINTF(DP_DROPS, "unknown IP version"); 252 return (EAFNOSUPPORT); 253 } 254 if (logdata != NULL) 255 nat64_log(logdata, m, af); 256 if (m->m_pkthdr.rcvif == NULL) 257 m->m_pkthdr.rcvif = V_loif; 258 ret = netisr_queue(ret, m); 259 if (ret != 0) 260 NAT64STAT_INC(stats, oerrors); 261 return (ret); 262 } 263 264 static int 265 nat64_output_one(struct mbuf *m, struct nat64_counters *stats, void *logdata) 266 { 267 268 return (nat64_output(NULL, m, NULL, stats, logdata)); 269 } 270 271 /* 272 * Check the given IPv6 prefix and length according to RFC6052: 273 * The prefixes can only have one of the following lengths: 274 * 32, 40, 48, 56, 64, or 96 (The Well-Known Prefix is 96 bits long). 275 * Returns zero on success, otherwise EINVAL. 276 */ 277 int 278 nat64_check_prefixlen(int length) 279 { 280 281 switch (length) { 282 case 32: 283 case 40: 284 case 48: 285 case 56: 286 case 64: 287 case 96: 288 return (0); 289 } 290 return (EINVAL); 291 } 292 293 int 294 nat64_check_prefix6(const struct in6_addr *prefix, int length) 295 { 296 297 if (nat64_check_prefixlen(length) != 0) 298 return (EINVAL); 299 300 /* Well-known prefix has 96 prefix length */ 301 if (IN6_IS_ADDR_WKPFX(prefix) && length != 96) 302 return (EINVAL); 303 304 /* Bits 64 to 71 must be set to zero */ 305 if (prefix->__u6_addr.__u6_addr8[8] != 0) 306 return (EINVAL); 307 308 /* Some extra checks */ 309 if (IN6_IS_ADDR_MULTICAST(prefix) || 310 IN6_IS_ADDR_UNSPECIFIED(prefix) || 311 IN6_IS_ADDR_LOOPBACK(prefix)) 312 return (EINVAL); 313 return (0); 314 } 315 316 int 317 nat64_check_private_ip4(const struct nat64_config *cfg, in_addr_t ia) 318 { 319 320 if (cfg->flags & NAT64_ALLOW_PRIVATE) 321 return (0); 322 323 /* WKPFX must not be used to represent non-global IPv4 addresses */ 324 if (cfg->flags & NAT64_WKPFX) { 325 /* IN_PRIVATE */ 326 if ((ia & htonl(0xff000000)) == htonl(0x0a000000) || 327 (ia & htonl(0xfff00000)) == htonl(0xac100000) || 328 (ia & htonl(0xffff0000)) == htonl(0xc0a80000)) 329 return (1); 330 /* 331 * RFC 5735: 332 * 192.0.0.0/24 - reserved for IETF protocol assignments 333 * 192.88.99.0/24 - for use as 6to4 relay anycast addresses 334 * 198.18.0.0/15 - for use in benchmark tests 335 * 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24 - for use 336 * in documentation and example code 337 */ 338 if ((ia & htonl(0xffffff00)) == htonl(0xc0000000) || 339 (ia & htonl(0xffffff00)) == htonl(0xc0586300) || 340 (ia & htonl(0xfffffe00)) == htonl(0xc6120000) || 341 (ia & htonl(0xffffff00)) == htonl(0xc0000200) || 342 (ia & htonl(0xfffffe00)) == htonl(0xc6336400) || 343 (ia & htonl(0xffffff00)) == htonl(0xcb007100)) 344 return (1); 345 } 346 return (0); 347 } 348 349 /* 350 * Embed @ia IPv4 address into @ip6 IPv6 address. 351 * Place to embedding determined from prefix length @plen. 352 */ 353 void 354 nat64_embed_ip4(struct in6_addr *ip6, int plen, in_addr_t ia) 355 { 356 357 switch (plen) { 358 case 32: 359 case 96: 360 ip6->s6_addr32[plen / 32] = ia; 361 break; 362 case 40: 363 case 48: 364 case 56: 365 /* 366 * Preserve prefix bits. 367 * Since suffix bits should be zero and reserved for future 368 * use, we just overwrite the whole word, where they are. 369 */ 370 ip6->s6_addr32[1] &= 0xffffffff << (32 - plen % 32); 371 #if BYTE_ORDER == BIG_ENDIAN 372 ip6->s6_addr32[1] |= ia >> (plen % 32); 373 ip6->s6_addr32[2] = ia << (24 - plen % 32); 374 #elif BYTE_ORDER == LITTLE_ENDIAN 375 ip6->s6_addr32[1] |= ia << (plen % 32); 376 ip6->s6_addr32[2] = ia >> (24 - plen % 32); 377 #endif 378 break; 379 case 64: 380 #if BYTE_ORDER == BIG_ENDIAN 381 ip6->s6_addr32[2] = ia >> 8; 382 ip6->s6_addr32[3] = ia << 24; 383 #elif BYTE_ORDER == LITTLE_ENDIAN 384 ip6->s6_addr32[2] = ia << 8; 385 ip6->s6_addr32[3] = ia >> 24; 386 #endif 387 break; 388 default: 389 panic("Wrong plen: %d", plen); 390 }; 391 /* 392 * Bits 64 to 71 of the address are reserved for compatibility 393 * with the host identifier format defined in the IPv6 addressing 394 * architecture [RFC4291]. These bits MUST be set to zero. 395 */ 396 ip6->s6_addr8[8] = 0; 397 } 398 399 in_addr_t 400 nat64_extract_ip4(const struct in6_addr *ip6, int plen) 401 { 402 in_addr_t ia; 403 404 /* 405 * According to RFC 6052 p2.2: 406 * IPv4-embedded IPv6 addresses are composed of a variable-length 407 * prefix, the embedded IPv4 address, and a variable length suffix. 408 * The suffix bits are reserved for future extensions and SHOULD 409 * be set to zero. 410 */ 411 switch (plen) { 412 case 32: 413 if (ip6->s6_addr32[3] != 0 || ip6->s6_addr32[2] != 0) 414 goto badip6; 415 break; 416 case 40: 417 if (ip6->s6_addr32[3] != 0 || 418 (ip6->s6_addr32[2] & htonl(0xff00ffff)) != 0) 419 goto badip6; 420 break; 421 case 48: 422 if (ip6->s6_addr32[3] != 0 || 423 (ip6->s6_addr32[2] & htonl(0xff0000ff)) != 0) 424 goto badip6; 425 break; 426 case 56: 427 if (ip6->s6_addr32[3] != 0 || ip6->s6_addr8[8] != 0) 428 goto badip6; 429 break; 430 case 64: 431 if (ip6->s6_addr8[8] != 0 || 432 (ip6->s6_addr32[3] & htonl(0x00ffffff)) != 0) 433 goto badip6; 434 }; 435 switch (plen) { 436 case 32: 437 case 96: 438 ia = ip6->s6_addr32[plen / 32]; 439 break; 440 case 40: 441 case 48: 442 case 56: 443 #if BYTE_ORDER == BIG_ENDIAN 444 ia = (ip6->s6_addr32[1] << (plen % 32)) | 445 (ip6->s6_addr32[2] >> (24 - plen % 32)); 446 #elif BYTE_ORDER == LITTLE_ENDIAN 447 ia = (ip6->s6_addr32[1] >> (plen % 32)) | 448 (ip6->s6_addr32[2] << (24 - plen % 32)); 449 #endif 450 break; 451 case 64: 452 #if BYTE_ORDER == BIG_ENDIAN 453 ia = (ip6->s6_addr32[2] << 8) | (ip6->s6_addr32[3] >> 24); 454 #elif BYTE_ORDER == LITTLE_ENDIAN 455 ia = (ip6->s6_addr32[2] >> 8) | (ip6->s6_addr32[3] << 24); 456 #endif 457 break; 458 default: 459 return (0); 460 }; 461 if (nat64_check_ip4(ia) == 0) 462 return (ia); 463 464 DPRINTF(DP_GENERIC | DP_DROPS, 465 "invalid destination address: %08x", ia); 466 return (0); 467 badip6: 468 DPRINTF(DP_GENERIC | DP_DROPS, "invalid IPv4-embedded IPv6 address"); 469 return (0); 470 } 471 472 /* 473 * According to RFC 1624 the equation for incremental checksum update is: 474 * HC' = ~(~HC + ~m + m') -- [Eqn. 3] 475 * HC' = HC - ~m - m' -- [Eqn. 4] 476 * So, when we are replacing IPv4 addresses to IPv6, we 477 * can assume, that new bytes previously were zeros, and vise versa - 478 * when we replacing IPv6 addresses to IPv4, now unused bytes become 479 * zeros. The payload length in pseudo header has bigger size, but one 480 * half of it should be zero. Using the equation 4 we get: 481 * HC' = HC - (~m0 + m0') -- m0 is first changed word 482 * HC' = (HC - (~m0 + m0')) - (~m1 + m1') -- m1 is second changed word 483 * HC' = HC - ~m0 - m0' - ~m1 - m1' - ... = 484 * = HC - sum(~m[i] + m'[i]) 485 * 486 * The function result should be used as follows: 487 * IPv6 to IPv4: HC' = cksum_add(HC, result) 488 * IPv4 to IPv6: HC' = cksum_add(HC, ~result) 489 */ 490 static uint16_t 491 nat64_cksum_convert(struct ip6_hdr *ip6, struct ip *ip) 492 { 493 uint32_t sum; 494 uint16_t *p; 495 496 sum = ~ip->ip_src.s_addr >> 16; 497 sum += ~ip->ip_src.s_addr & 0xffff; 498 sum += ~ip->ip_dst.s_addr >> 16; 499 sum += ~ip->ip_dst.s_addr & 0xffff; 500 501 for (p = (uint16_t *)&ip6->ip6_src; 502 p < (uint16_t *)(&ip6->ip6_src + 2); p++) 503 sum += *p; 504 505 while (sum >> 16) 506 sum = (sum & 0xffff) + (sum >> 16); 507 return (sum); 508 } 509 510 static void 511 nat64_init_ip4hdr(const struct ip6_hdr *ip6, const struct ip6_frag *frag, 512 uint16_t plen, uint8_t proto, struct ip *ip) 513 { 514 515 /* assume addresses are already initialized */ 516 ip->ip_v = IPVERSION; 517 ip->ip_hl = sizeof(*ip) >> 2; 518 ip->ip_tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 519 ip->ip_len = htons(sizeof(*ip) + plen); 520 ip->ip_ttl = ip6->ip6_hlim; 521 if (*V_nat64ip6stealth == 0) 522 ip->ip_ttl -= IPV6_HLIMDEC; 523 ip->ip_sum = 0; 524 ip->ip_p = (proto == IPPROTO_ICMPV6) ? IPPROTO_ICMP: proto; 525 ip_fillid(ip); 526 if (frag != NULL) { 527 ip->ip_off = htons(ntohs(frag->ip6f_offlg) >> 3); 528 if (frag->ip6f_offlg & IP6F_MORE_FRAG) 529 ip->ip_off |= htons(IP_MF); 530 } else { 531 ip->ip_off = htons(IP_DF); 532 } 533 ip->ip_sum = in_cksum_hdr(ip); 534 } 535 536 #define FRAGSZ(mtu) ((mtu) - sizeof(struct ip6_hdr) - sizeof(struct ip6_frag)) 537 static NAT64NOINLINE int 538 nat64_fragment6(struct nat64_counters *stats, struct ip6_hdr *ip6, 539 struct mbufq *mq, struct mbuf *m, uint32_t mtu, uint16_t ip_id, 540 uint16_t ip_off) 541 { 542 struct ip6_frag ip6f; 543 struct mbuf *n; 544 uint16_t hlen, len, offset; 545 int plen; 546 547 plen = ntohs(ip6->ip6_plen); 548 hlen = sizeof(struct ip6_hdr); 549 550 /* Fragmentation isn't needed */ 551 if (ip_off == 0 && plen <= mtu - hlen) { 552 M_PREPEND(m, hlen, M_NOWAIT); 553 if (m == NULL) { 554 NAT64STAT_INC(stats, nomem); 555 return (ENOMEM); 556 } 557 bcopy(ip6, mtod(m, void *), hlen); 558 if (mbufq_enqueue(mq, m) != 0) { 559 m_freem(m); 560 NAT64STAT_INC(stats, dropped); 561 DPRINTF(DP_DROPS, "dropped due to mbufq overflow"); 562 return (ENOBUFS); 563 } 564 return (0); 565 } 566 567 hlen += sizeof(struct ip6_frag); 568 ip6f.ip6f_reserved = 0; 569 ip6f.ip6f_nxt = ip6->ip6_nxt; 570 ip6->ip6_nxt = IPPROTO_FRAGMENT; 571 if (ip_off != 0) { 572 /* 573 * We have got an IPv4 fragment. 574 * Use offset value and ip_id from original fragment. 575 */ 576 ip6f.ip6f_ident = htonl(ntohs(ip_id)); 577 offset = (ntohs(ip_off) & IP_OFFMASK) << 3; 578 NAT64STAT_INC(stats, ifrags); 579 } else { 580 /* The packet size exceeds interface MTU */ 581 ip6f.ip6f_ident = htonl(ip6_randomid()); 582 offset = 0; /* First fragment*/ 583 } 584 while (plen > 0 && m != NULL) { 585 n = NULL; 586 len = FRAGSZ(mtu) & ~7; 587 if (len > plen) 588 len = plen; 589 ip6->ip6_plen = htons(len + sizeof(ip6f)); 590 ip6f.ip6f_offlg = ntohs(offset); 591 if (len < plen || (ip_off & htons(IP_MF)) != 0) 592 ip6f.ip6f_offlg |= IP6F_MORE_FRAG; 593 offset += len; 594 plen -= len; 595 if (plen > 0) { 596 n = m_split(m, len, M_NOWAIT); 597 if (n == NULL) 598 goto fail; 599 } 600 M_PREPEND(m, hlen, M_NOWAIT); 601 if (m == NULL) 602 goto fail; 603 bcopy(ip6, mtod(m, void *), sizeof(struct ip6_hdr)); 604 bcopy(&ip6f, mtodo(m, sizeof(struct ip6_hdr)), 605 sizeof(struct ip6_frag)); 606 if (mbufq_enqueue(mq, m) != 0) 607 goto fail; 608 m = n; 609 } 610 NAT64STAT_ADD(stats, ofrags, mbufq_len(mq)); 611 return (0); 612 fail: 613 if (m != NULL) 614 m_freem(m); 615 if (n != NULL) 616 m_freem(n); 617 mbufq_drain(mq); 618 NAT64STAT_INC(stats, nomem); 619 return (ENOMEM); 620 } 621 622 static struct nhop_object * 623 nat64_find_route6(struct sockaddr_in6 *dst, struct mbuf *m) 624 { 625 struct nhop_object *nh; 626 NET_EPOCH_ASSERT(); 627 nh = fib6_lookup(M_GETFIB(m), &dst->sin6_addr, 0, 0, 0); 628 if (nh == NULL) 629 return NULL; 630 if (nh->nh_flags & (NHF_BLACKHOLE | NHF_REJECT)) 631 return NULL; 632 /* 633 * XXX: we need to use destination address with embedded scope 634 * zone id, because LLTABLE uses such form of addresses for lookup. 635 */ 636 dst->sin6_family = AF_INET6; 637 dst->sin6_len = sizeof(*dst); 638 dst->sin6_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; 639 if (IN6_IS_SCOPE_LINKLOCAL(&dst->sin6_addr)) 640 dst->sin6_addr.s6_addr16[1] = 641 htons(nh->nh_ifp->if_index & 0xffff); 642 dst->sin6_port = 0; 643 dst->sin6_scope_id = 0; 644 dst->sin6_flowinfo = 0; 645 646 return nh; 647 } 648 649 #define NAT64_ICMP6_PLEN 64 650 static NAT64NOINLINE void 651 nat64_icmp6_reflect(struct mbuf *m, uint8_t type, uint8_t code, uint32_t mtu, 652 struct nat64_counters *stats, void *logdata) 653 { 654 struct icmp6_hdr *icmp6; 655 struct ip6_hdr *ip6, *oip6; 656 struct mbuf *n; 657 int len, plen, proto; 658 659 len = 0; 660 proto = nat64_getlasthdr(m, &len); 661 if (proto < 0) { 662 DPRINTF(DP_DROPS, "mbuf isn't contigious"); 663 goto freeit; 664 } 665 /* 666 * Do not send ICMPv6 in reply to ICMPv6 errors. 667 */ 668 if (proto == IPPROTO_ICMPV6) { 669 if (m->m_len < len + sizeof(*icmp6)) { 670 DPRINTF(DP_DROPS, "mbuf isn't contigious"); 671 goto freeit; 672 } 673 icmp6 = mtodo(m, len); 674 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST || 675 icmp6->icmp6_type == ND_REDIRECT) { 676 DPRINTF(DP_DROPS, "do not send ICMPv6 in reply to " 677 "ICMPv6 errors"); 678 goto freeit; 679 } 680 /* 681 * If there are extra headers between IPv6 and ICMPv6, 682 * strip off them. 683 */ 684 if (len > sizeof(struct ip6_hdr)) { 685 /* 686 * NOTE: ipfw_chk already did m_pullup() and it is 687 * expected that data is contigious from the start 688 * of IPv6 header up to the end of ICMPv6 header. 689 */ 690 bcopy(mtod(m, caddr_t), 691 mtodo(m, len - sizeof(struct ip6_hdr)), 692 sizeof(struct ip6_hdr)); 693 m_adj(m, len - sizeof(struct ip6_hdr)); 694 } 695 } 696 /* 697 if (icmp6_ratelimit(&ip6->ip6_src, type, code)) 698 goto freeit; 699 */ 700 ip6 = mtod(m, struct ip6_hdr *); 701 switch (type) { 702 case ICMP6_DST_UNREACH: 703 case ICMP6_PACKET_TOO_BIG: 704 case ICMP6_TIME_EXCEEDED: 705 case ICMP6_PARAM_PROB: 706 break; 707 default: 708 goto freeit; 709 } 710 /* Calculate length of ICMPv6 payload */ 711 len = (m->m_pkthdr.len > NAT64_ICMP6_PLEN) ? NAT64_ICMP6_PLEN: 712 m->m_pkthdr.len; 713 714 /* Create new ICMPv6 datagram */ 715 plen = len + sizeof(struct icmp6_hdr); 716 n = m_get2(sizeof(struct ip6_hdr) + plen + max_hdr, M_NOWAIT, 717 MT_HEADER, M_PKTHDR); 718 if (n == NULL) { 719 NAT64STAT_INC(stats, nomem); 720 m_freem(m); 721 return; 722 } 723 /* 724 * Move pkthdr from original mbuf. We should have initialized some 725 * fields, because we can reinject this mbuf to netisr and it will 726 * go trough input path (it requires at least rcvif should be set). 727 * Also do M_ALIGN() to reduce chances of need to allocate new mbuf 728 * in the chain, when we will do M_PREPEND() or make some type of 729 * tunneling. 730 */ 731 m_move_pkthdr(n, m); 732 M_ALIGN(n, sizeof(struct ip6_hdr) + plen + max_hdr); 733 734 n->m_len = n->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 735 oip6 = mtod(n, struct ip6_hdr *); 736 /* 737 * Make IPv6 source address selection for reflected datagram. 738 * nat64_check_ip6() doesn't allow scoped addresses, therefore 739 * we use zero scopeid. 740 */ 741 if (in6_selectsrc_addr(M_GETFIB(n), &ip6->ip6_src, 0, 742 n->m_pkthdr.rcvif, &oip6->ip6_src, NULL) != 0) { 743 /* 744 * Failed to find proper source address, drop the packet. 745 */ 746 m_freem(n); 747 goto freeit; 748 } 749 oip6->ip6_dst = ip6->ip6_src; 750 oip6->ip6_nxt = IPPROTO_ICMPV6; 751 oip6->ip6_flow = 0; 752 oip6->ip6_vfc |= IPV6_VERSION; 753 oip6->ip6_hlim = V_ip6_defhlim; 754 oip6->ip6_plen = htons(plen); 755 756 icmp6 = mtodo(n, sizeof(struct ip6_hdr)); 757 icmp6->icmp6_cksum = 0; 758 icmp6->icmp6_type = type; 759 icmp6->icmp6_code = code; 760 icmp6->icmp6_mtu = htonl(mtu); 761 762 m_copydata(m, 0, len, mtodo(n, sizeof(struct ip6_hdr) + 763 sizeof(struct icmp6_hdr))); 764 icmp6->icmp6_cksum = in6_cksum(n, IPPROTO_ICMPV6, 765 sizeof(struct ip6_hdr), plen); 766 m_freem(m); 767 V_nat64out->output_one(n, stats, logdata); 768 return; 769 freeit: 770 NAT64STAT_INC(stats, dropped); 771 m_freem(m); 772 } 773 774 static struct nhop_object * 775 nat64_find_route4(struct sockaddr_in *dst, struct mbuf *m) 776 { 777 struct nhop_object *nh; 778 779 NET_EPOCH_ASSERT(); 780 nh = fib4_lookup(M_GETFIB(m), dst->sin_addr, 0, 0, 0); 781 if (nh == NULL) 782 return NULL; 783 if (nh->nh_flags & (NHF_BLACKHOLE | NHF_BROADCAST | NHF_REJECT)) 784 return NULL; 785 786 dst->sin_family = AF_INET; 787 dst->sin_len = sizeof(*dst); 788 dst->sin_addr = IA_SIN(nh->nh_ifa)->sin_addr; 789 dst->sin_port = 0; 790 return nh; 791 } 792 793 #define NAT64_ICMP_PLEN 64 794 static NAT64NOINLINE void 795 nat64_icmp_reflect(struct mbuf *m, uint8_t type, 796 uint8_t code, uint16_t mtu, struct nat64_counters *stats, void *logdata) 797 { 798 struct icmp *icmp; 799 struct ip *ip, *oip; 800 struct mbuf *n; 801 int len, plen; 802 803 ip = mtod(m, struct ip *); 804 /* Do not send ICMP error if packet is not the first fragment */ 805 if (ip->ip_off & ~ntohs(IP_MF|IP_DF)) { 806 DPRINTF(DP_DROPS, "not first fragment"); 807 goto freeit; 808 } 809 /* Do not send ICMP in reply to ICMP errors */ 810 if (ip->ip_p == IPPROTO_ICMP) { 811 if (m->m_len < (ip->ip_hl << 2)) { 812 DPRINTF(DP_DROPS, "mbuf isn't contigious"); 813 goto freeit; 814 } 815 icmp = mtodo(m, ip->ip_hl << 2); 816 if (!ICMP_INFOTYPE(icmp->icmp_type)) { 817 DPRINTF(DP_DROPS, "do not send ICMP in reply to " 818 "ICMP errors"); 819 goto freeit; 820 } 821 } 822 switch (type) { 823 case ICMP_UNREACH: 824 case ICMP_TIMXCEED: 825 case ICMP_PARAMPROB: 826 break; 827 default: 828 goto freeit; 829 } 830 /* Calculate length of ICMP payload */ 831 len = (m->m_pkthdr.len > NAT64_ICMP_PLEN) ? (ip->ip_hl << 2) + 8: 832 m->m_pkthdr.len; 833 834 /* Create new ICMPv4 datagram */ 835 plen = len + sizeof(struct icmphdr) + sizeof(uint32_t); 836 n = m_get2(sizeof(struct ip) + plen + max_hdr, M_NOWAIT, 837 MT_HEADER, M_PKTHDR); 838 if (n == NULL) { 839 NAT64STAT_INC(stats, nomem); 840 m_freem(m); 841 return; 842 } 843 m_move_pkthdr(n, m); 844 M_ALIGN(n, sizeof(struct ip) + plen + max_hdr); 845 846 n->m_len = n->m_pkthdr.len = sizeof(struct ip) + plen; 847 oip = mtod(n, struct ip *); 848 oip->ip_v = IPVERSION; 849 oip->ip_hl = sizeof(struct ip) >> 2; 850 oip->ip_tos = 0; 851 oip->ip_len = htons(n->m_pkthdr.len); 852 oip->ip_ttl = V_ip_defttl; 853 oip->ip_p = IPPROTO_ICMP; 854 ip_fillid(oip); 855 oip->ip_off = htons(IP_DF); 856 oip->ip_src = ip->ip_dst; 857 oip->ip_dst = ip->ip_src; 858 oip->ip_sum = 0; 859 oip->ip_sum = in_cksum_hdr(oip); 860 861 icmp = mtodo(n, sizeof(struct ip)); 862 icmp->icmp_type = type; 863 icmp->icmp_code = code; 864 icmp->icmp_cksum = 0; 865 icmp->icmp_pmvoid = 0; 866 icmp->icmp_nextmtu = htons(mtu); 867 m_copydata(m, 0, len, mtodo(n, sizeof(struct ip) + 868 sizeof(struct icmphdr) + sizeof(uint32_t))); 869 icmp->icmp_cksum = in_cksum_skip(n, sizeof(struct ip) + plen, 870 sizeof(struct ip)); 871 m_freem(m); 872 V_nat64out->output_one(n, stats, logdata); 873 return; 874 freeit: 875 NAT64STAT_INC(stats, dropped); 876 m_freem(m); 877 } 878 879 /* Translate ICMP echo request/reply into ICMPv6 */ 880 static void 881 nat64_icmp_handle_echo(struct ip6_hdr *ip6, struct icmp6_hdr *icmp6, 882 uint16_t id, uint8_t type) 883 { 884 uint16_t old; 885 886 old = *(uint16_t *)icmp6; /* save type+code in one word */ 887 icmp6->icmp6_type = type; 888 /* Reflect ICMPv6 -> ICMPv4 type translation in the cksum */ 889 icmp6->icmp6_cksum = cksum_adjust(icmp6->icmp6_cksum, 890 old, *(uint16_t *)icmp6); 891 if (id != 0) { 892 old = icmp6->icmp6_id; 893 icmp6->icmp6_id = id; 894 /* Reflect ICMP id translation in the cksum */ 895 icmp6->icmp6_cksum = cksum_adjust(icmp6->icmp6_cksum, 896 old, id); 897 } 898 /* Reflect IPv6 pseudo header in the cksum */ 899 icmp6->icmp6_cksum = ~in6_cksum_pseudo(ip6, ntohs(ip6->ip6_plen), 900 IPPROTO_ICMPV6, ~icmp6->icmp6_cksum); 901 } 902 903 static NAT64NOINLINE struct mbuf * 904 nat64_icmp_translate(struct mbuf *m, struct ip6_hdr *ip6, uint16_t icmpid, 905 int offset, struct nat64_config *cfg) 906 { 907 struct ip ip; 908 struct icmp *icmp; 909 struct tcphdr *tcp; 910 struct udphdr *udp; 911 struct ip6_hdr *eip6; 912 struct mbuf *n; 913 uint32_t mtu; 914 int len, hlen, plen; 915 uint8_t type, code; 916 917 if (m->m_len < offset + ICMP_MINLEN) 918 m = m_pullup(m, offset + ICMP_MINLEN); 919 if (m == NULL) { 920 NAT64STAT_INC(&cfg->stats, nomem); 921 return (m); 922 } 923 mtu = 0; 924 icmp = mtodo(m, offset); 925 /* RFC 7915 p4.2 */ 926 switch (icmp->icmp_type) { 927 case ICMP_ECHOREPLY: 928 type = ICMP6_ECHO_REPLY; 929 code = 0; 930 break; 931 case ICMP_UNREACH: 932 type = ICMP6_DST_UNREACH; 933 switch (icmp->icmp_code) { 934 case ICMP_UNREACH_NET: 935 case ICMP_UNREACH_HOST: 936 case ICMP_UNREACH_SRCFAIL: 937 case ICMP_UNREACH_NET_UNKNOWN: 938 case ICMP_UNREACH_HOST_UNKNOWN: 939 case ICMP_UNREACH_TOSNET: 940 case ICMP_UNREACH_TOSHOST: 941 code = ICMP6_DST_UNREACH_NOROUTE; 942 break; 943 case ICMP_UNREACH_PROTOCOL: 944 type = ICMP6_PARAM_PROB; 945 code = ICMP6_PARAMPROB_NEXTHEADER; 946 break; 947 case ICMP_UNREACH_PORT: 948 code = ICMP6_DST_UNREACH_NOPORT; 949 break; 950 case ICMP_UNREACH_NEEDFRAG: 951 type = ICMP6_PACKET_TOO_BIG; 952 code = 0; 953 /* XXX: needs an additional look */ 954 mtu = max(IPV6_MMTU, ntohs(icmp->icmp_nextmtu) + 20); 955 break; 956 case ICMP_UNREACH_NET_PROHIB: 957 case ICMP_UNREACH_HOST_PROHIB: 958 case ICMP_UNREACH_FILTER_PROHIB: 959 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 960 code = ICMP6_DST_UNREACH_ADMIN; 961 break; 962 default: 963 DPRINTF(DP_DROPS, "Unsupported ICMP type %d, code %d", 964 icmp->icmp_type, icmp->icmp_code); 965 goto freeit; 966 } 967 break; 968 case ICMP_TIMXCEED: 969 type = ICMP6_TIME_EXCEEDED; 970 code = icmp->icmp_code; 971 break; 972 case ICMP_ECHO: 973 type = ICMP6_ECHO_REQUEST; 974 code = 0; 975 break; 976 case ICMP_PARAMPROB: 977 type = ICMP6_PARAM_PROB; 978 switch (icmp->icmp_code) { 979 case ICMP_PARAMPROB_ERRATPTR: 980 case ICMP_PARAMPROB_LENGTH: 981 code = ICMP6_PARAMPROB_HEADER; 982 switch (icmp->icmp_pptr) { 983 case 0: /* Version/IHL */ 984 case 1: /* Type Of Service */ 985 mtu = icmp->icmp_pptr; 986 break; 987 case 2: /* Total Length */ 988 case 3: mtu = 4; /* Payload Length */ 989 break; 990 case 8: /* Time to Live */ 991 mtu = 7; /* Hop Limit */ 992 break; 993 case 9: /* Protocol */ 994 mtu = 6; /* Next Header */ 995 break; 996 case 12: /* Source address */ 997 case 13: 998 case 14: 999 case 15: 1000 mtu = 8; 1001 break; 1002 case 16: /* Destination address */ 1003 case 17: 1004 case 18: 1005 case 19: 1006 mtu = 24; 1007 break; 1008 default: /* Silently drop */ 1009 DPRINTF(DP_DROPS, "Unsupported ICMP type %d," 1010 " code %d, pptr %d", icmp->icmp_type, 1011 icmp->icmp_code, icmp->icmp_pptr); 1012 goto freeit; 1013 } 1014 break; 1015 default: 1016 DPRINTF(DP_DROPS, "Unsupported ICMP type %d," 1017 " code %d, pptr %d", icmp->icmp_type, 1018 icmp->icmp_code, icmp->icmp_pptr); 1019 goto freeit; 1020 } 1021 break; 1022 default: 1023 DPRINTF(DP_DROPS, "Unsupported ICMP type %d, code %d", 1024 icmp->icmp_type, icmp->icmp_code); 1025 goto freeit; 1026 } 1027 /* 1028 * For echo request/reply we can use original payload, 1029 * but we need adjust icmp_cksum, because ICMPv6 cksum covers 1030 * IPv6 pseudo header and ICMPv6 types differs from ICMPv4. 1031 */ 1032 if (type == ICMP6_ECHO_REQUEST || type == ICMP6_ECHO_REPLY) { 1033 nat64_icmp_handle_echo(ip6, ICMP6(icmp), icmpid, type); 1034 return (m); 1035 } 1036 /* 1037 * For other types of ICMP messages we need to translate inner 1038 * IPv4 header to IPv6 header. 1039 * Assume ICMP src is the same as payload dst 1040 * E.g. we have ( GWsrc1 , NATIP1 ) in outer header 1041 * and ( NATIP1, Hostdst1 ) in ICMP copy header. 1042 * In that case, we already have map for NATIP1 and GWsrc1. 1043 * The only thing we need is to copy IPv6 map prefix to 1044 * Hostdst1. 1045 */ 1046 hlen = offset + ICMP_MINLEN; 1047 if (m->m_pkthdr.len < hlen + sizeof(struct ip) + ICMP_MINLEN) { 1048 DPRINTF(DP_DROPS, "Message is too short %d", 1049 m->m_pkthdr.len); 1050 goto freeit; 1051 } 1052 m_copydata(m, hlen, sizeof(struct ip), (char *)&ip); 1053 if (ip.ip_v != IPVERSION) { 1054 DPRINTF(DP_DROPS, "Wrong IP version %d", ip.ip_v); 1055 goto freeit; 1056 } 1057 hlen += ip.ip_hl << 2; /* Skip inner IP header */ 1058 if (nat64_check_ip4(ip.ip_src.s_addr) != 0 || 1059 nat64_check_ip4(ip.ip_dst.s_addr) != 0 || 1060 nat64_check_private_ip4(cfg, ip.ip_src.s_addr) != 0 || 1061 nat64_check_private_ip4(cfg, ip.ip_dst.s_addr) != 0) { 1062 DPRINTF(DP_DROPS, "IP addresses checks failed %04x -> %04x", 1063 ntohl(ip.ip_src.s_addr), ntohl(ip.ip_dst.s_addr)); 1064 goto freeit; 1065 } 1066 if (m->m_pkthdr.len < hlen + ICMP_MINLEN) { 1067 DPRINTF(DP_DROPS, "Message is too short %d", 1068 m->m_pkthdr.len); 1069 goto freeit; 1070 } 1071 #if 0 1072 /* 1073 * Check that inner source matches the outer destination. 1074 * XXX: We need some method to convert IPv4 into IPv6 address here, 1075 * and compare IPv6 addresses. 1076 */ 1077 if (ip.ip_src.s_addr != nat64_get_ip4(&ip6->ip6_dst)) { 1078 DPRINTF(DP_GENERIC, "Inner source doesn't match destination ", 1079 "%04x vs %04x", ip.ip_src.s_addr, 1080 nat64_get_ip4(&ip6->ip6_dst)); 1081 goto freeit; 1082 } 1083 #endif 1084 /* 1085 * Create new mbuf for ICMPv6 datagram. 1086 * NOTE: len is data length just after inner IP header. 1087 */ 1088 len = m->m_pkthdr.len - hlen; 1089 if (sizeof(struct ip6_hdr) + 1090 sizeof(struct icmp6_hdr) + len > NAT64_ICMP6_PLEN) 1091 len = NAT64_ICMP6_PLEN - sizeof(struct icmp6_hdr) - 1092 sizeof(struct ip6_hdr); 1093 plen = sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr) + len; 1094 n = m_get2(offset + plen + max_hdr, M_NOWAIT, MT_HEADER, M_PKTHDR); 1095 if (n == NULL) { 1096 NAT64STAT_INC(&cfg->stats, nomem); 1097 m_freem(m); 1098 return (NULL); 1099 } 1100 m_move_pkthdr(n, m); 1101 M_ALIGN(n, offset + plen + max_hdr); 1102 n->m_len = n->m_pkthdr.len = offset + plen; 1103 /* Adjust ip6_plen in outer header */ 1104 ip6->ip6_plen = htons(plen); 1105 /* Construct new inner IPv6 header */ 1106 eip6 = mtodo(n, offset + sizeof(struct icmp6_hdr)); 1107 eip6->ip6_src = ip6->ip6_dst; 1108 1109 /* Use the same prefix that we have in outer header */ 1110 eip6->ip6_dst = ip6->ip6_src; 1111 MPASS(cfg->flags & NAT64_PLATPFX); 1112 nat64_embed_ip4(&eip6->ip6_dst, cfg->plat_plen, ip.ip_dst.s_addr); 1113 1114 eip6->ip6_flow = htonl(ip.ip_tos << 20); 1115 eip6->ip6_vfc |= IPV6_VERSION; 1116 eip6->ip6_hlim = ip.ip_ttl; 1117 eip6->ip6_plen = htons(ntohs(ip.ip_len) - (ip.ip_hl << 2)); 1118 eip6->ip6_nxt = (ip.ip_p == IPPROTO_ICMP) ? IPPROTO_ICMPV6: ip.ip_p; 1119 m_copydata(m, hlen, len, (char *)(eip6 + 1)); 1120 /* 1121 * We need to translate source port in the inner ULP header, 1122 * and adjust ULP checksum. 1123 */ 1124 switch (ip.ip_p) { 1125 case IPPROTO_TCP: 1126 if (len < offsetof(struct tcphdr, th_sum)) 1127 break; 1128 tcp = TCP(eip6 + 1); 1129 if (icmpid != 0) { 1130 tcp->th_sum = cksum_adjust(tcp->th_sum, 1131 tcp->th_sport, icmpid); 1132 tcp->th_sport = icmpid; 1133 } 1134 tcp->th_sum = cksum_add(tcp->th_sum, 1135 ~nat64_cksum_convert(eip6, &ip)); 1136 break; 1137 case IPPROTO_UDP: 1138 if (len < offsetof(struct udphdr, uh_sum)) 1139 break; 1140 udp = UDP(eip6 + 1); 1141 if (icmpid != 0) { 1142 udp->uh_sum = cksum_adjust(udp->uh_sum, 1143 udp->uh_sport, icmpid); 1144 udp->uh_sport = icmpid; 1145 } 1146 udp->uh_sum = cksum_add(udp->uh_sum, 1147 ~nat64_cksum_convert(eip6, &ip)); 1148 break; 1149 case IPPROTO_ICMP: 1150 /* 1151 * Check if this is an ICMP error message for echo request 1152 * that we sent. I.e. ULP in the data containing invoking 1153 * packet is IPPROTO_ICMP and its type is ICMP_ECHO. 1154 */ 1155 icmp = (struct icmp *)(eip6 + 1); 1156 if (icmp->icmp_type != ICMP_ECHO) { 1157 m_freem(n); 1158 goto freeit; 1159 } 1160 /* 1161 * For our client this original datagram should looks 1162 * like it was ICMPv6 datagram with type ICMP6_ECHO_REQUEST. 1163 * Thus we need adjust icmp_cksum and convert type from 1164 * ICMP_ECHO to ICMP6_ECHO_REQUEST. 1165 */ 1166 nat64_icmp_handle_echo(eip6, ICMP6(icmp), icmpid, 1167 ICMP6_ECHO_REQUEST); 1168 } 1169 m_freem(m); 1170 /* Convert ICMPv4 into ICMPv6 header */ 1171 icmp = mtodo(n, offset); 1172 ICMP6(icmp)->icmp6_type = type; 1173 ICMP6(icmp)->icmp6_code = code; 1174 ICMP6(icmp)->icmp6_mtu = htonl(mtu); 1175 ICMP6(icmp)->icmp6_cksum = 0; 1176 ICMP6(icmp)->icmp6_cksum = cksum_add( 1177 ~in6_cksum_pseudo(ip6, plen, IPPROTO_ICMPV6, 0), 1178 in_cksum_skip(n, n->m_pkthdr.len, offset)); 1179 return (n); 1180 freeit: 1181 m_freem(m); 1182 NAT64STAT_INC(&cfg->stats, dropped); 1183 return (NULL); 1184 } 1185 1186 int 1187 nat64_getlasthdr(struct mbuf *m, int *offset) 1188 { 1189 struct ip6_hdr *ip6; 1190 struct ip6_hbh *hbh; 1191 int proto, hlen; 1192 1193 if (offset != NULL) 1194 hlen = *offset; 1195 else 1196 hlen = 0; 1197 1198 if (m->m_len < hlen + sizeof(*ip6)) 1199 return (-1); 1200 1201 ip6 = mtodo(m, hlen); 1202 hlen += sizeof(*ip6); 1203 proto = ip6->ip6_nxt; 1204 /* Skip extension headers */ 1205 while (proto == IPPROTO_HOPOPTS || proto == IPPROTO_ROUTING || 1206 proto == IPPROTO_DSTOPTS) { 1207 hbh = mtodo(m, hlen); 1208 /* 1209 * We expect mbuf has contigious data up to 1210 * upper level header. 1211 */ 1212 if (m->m_len < hlen) 1213 return (-1); 1214 /* 1215 * We doesn't support Jumbo payload option, 1216 * so return error. 1217 */ 1218 if (proto == IPPROTO_HOPOPTS && ip6->ip6_plen == 0) 1219 return (-1); 1220 proto = hbh->ip6h_nxt; 1221 hlen += (hbh->ip6h_len + 1) << 3; 1222 } 1223 if (offset != NULL) 1224 *offset = hlen; 1225 return (proto); 1226 } 1227 1228 int 1229 nat64_do_handle_ip4(struct mbuf *m, struct in6_addr *saddr, 1230 struct in6_addr *daddr, uint16_t lport, struct nat64_config *cfg, 1231 void *logdata) 1232 { 1233 struct nhop_object *nh; 1234 struct ip6_hdr ip6; 1235 struct sockaddr_in6 dst; 1236 struct ip *ip; 1237 struct mbufq mq; 1238 uint16_t ip_id, ip_off; 1239 uint16_t *csum; 1240 int plen, hlen; 1241 uint8_t proto; 1242 1243 ip = mtod(m, struct ip*); 1244 1245 if (*V_nat64ipstealth == 0 && ip->ip_ttl <= IPTTLDEC) { 1246 nat64_icmp_reflect(m, ICMP_TIMXCEED, 1247 ICMP_TIMXCEED_INTRANS, 0, &cfg->stats, logdata); 1248 return (NAT64RETURN); 1249 } 1250 1251 ip6.ip6_dst = *daddr; 1252 ip6.ip6_src = *saddr; 1253 1254 hlen = ip->ip_hl << 2; 1255 plen = ntohs(ip->ip_len) - hlen; 1256 proto = ip->ip_p; 1257 1258 /* Save ip_id and ip_off, both are in network byte order */ 1259 ip_id = ip->ip_id; 1260 ip_off = ip->ip_off & htons(IP_OFFMASK | IP_MF); 1261 1262 /* Fragment length must be multiple of 8 octets */ 1263 if ((ip->ip_off & htons(IP_MF)) != 0 && (plen & 0x7) != 0) { 1264 nat64_icmp_reflect(m, ICMP_PARAMPROB, 1265 ICMP_PARAMPROB_LENGTH, 0, &cfg->stats, logdata); 1266 return (NAT64RETURN); 1267 } 1268 /* Fragmented ICMP is unsupported */ 1269 if (proto == IPPROTO_ICMP && ip_off != 0) { 1270 DPRINTF(DP_DROPS, "dropped due to fragmented ICMP"); 1271 NAT64STAT_INC(&cfg->stats, dropped); 1272 return (NAT64MFREE); 1273 } 1274 1275 dst.sin6_addr = ip6.ip6_dst; 1276 nh = nat64_find_route6(&dst, m); 1277 if (nh == NULL) { 1278 NAT64STAT_INC(&cfg->stats, noroute6); 1279 nat64_icmp_reflect(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 1280 &cfg->stats, logdata); 1281 return (NAT64RETURN); 1282 } 1283 if (nh->nh_mtu < plen + sizeof(ip6) && 1284 (ip->ip_off & htons(IP_DF)) != 0) { 1285 nat64_icmp_reflect(m, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 1286 FRAGSZ(nh->nh_mtu) + sizeof(struct ip), &cfg->stats, logdata); 1287 return (NAT64RETURN); 1288 } 1289 1290 ip6.ip6_flow = htonl(ip->ip_tos << 20); 1291 ip6.ip6_vfc |= IPV6_VERSION; 1292 ip6.ip6_hlim = ip->ip_ttl; 1293 if (*V_nat64ipstealth == 0) 1294 ip6.ip6_hlim -= IPTTLDEC; 1295 ip6.ip6_plen = htons(plen); 1296 ip6.ip6_nxt = (proto == IPPROTO_ICMP) ? IPPROTO_ICMPV6: proto; 1297 /* Convert checksums. */ 1298 switch (proto) { 1299 case IPPROTO_TCP: 1300 csum = &TCP(mtodo(m, hlen))->th_sum; 1301 if (lport != 0) { 1302 struct tcphdr *tcp = TCP(mtodo(m, hlen)); 1303 *csum = cksum_adjust(*csum, tcp->th_dport, lport); 1304 tcp->th_dport = lport; 1305 } 1306 *csum = cksum_add(*csum, ~nat64_cksum_convert(&ip6, ip)); 1307 break; 1308 case IPPROTO_UDP: 1309 csum = &UDP(mtodo(m, hlen))->uh_sum; 1310 if (lport != 0) { 1311 struct udphdr *udp = UDP(mtodo(m, hlen)); 1312 *csum = cksum_adjust(*csum, udp->uh_dport, lport); 1313 udp->uh_dport = lport; 1314 } 1315 *csum = cksum_add(*csum, ~nat64_cksum_convert(&ip6, ip)); 1316 break; 1317 case IPPROTO_ICMP: 1318 m = nat64_icmp_translate(m, &ip6, lport, hlen, cfg); 1319 if (m == NULL) /* stats already accounted */ 1320 return (NAT64RETURN); 1321 } 1322 1323 m_adj(m, hlen); 1324 mbufq_init(&mq, 255); 1325 nat64_fragment6(&cfg->stats, &ip6, &mq, m, nh->nh_mtu, ip_id, ip_off); 1326 while ((m = mbufq_dequeue(&mq)) != NULL) { 1327 if (V_nat64out->output(nh->nh_ifp, m, (struct sockaddr *)&dst, 1328 &cfg->stats, logdata) != 0) 1329 break; 1330 NAT64STAT_INC(&cfg->stats, opcnt46); 1331 } 1332 mbufq_drain(&mq); 1333 return (NAT64RETURN); 1334 } 1335 1336 int 1337 nat64_handle_icmp6(struct mbuf *m, int hlen, uint32_t aaddr, uint16_t aport, 1338 struct nat64_config *cfg, void *logdata) 1339 { 1340 struct ip ip; 1341 struct icmp6_hdr *icmp6; 1342 struct ip6_frag *ip6f; 1343 struct ip6_hdr *ip6, *ip6i; 1344 uint32_t mtu; 1345 int plen, proto; 1346 uint8_t type, code; 1347 1348 if (hlen == 0) { 1349 ip6 = mtod(m, struct ip6_hdr *); 1350 if (nat64_check_ip6(&ip6->ip6_src) != 0 || 1351 nat64_check_ip6(&ip6->ip6_dst) != 0) 1352 return (NAT64SKIP); 1353 1354 proto = nat64_getlasthdr(m, &hlen); 1355 if (proto != IPPROTO_ICMPV6) { 1356 DPRINTF(DP_DROPS, 1357 "dropped due to mbuf isn't contigious"); 1358 NAT64STAT_INC(&cfg->stats, dropped); 1359 return (NAT64MFREE); 1360 } 1361 } 1362 1363 /* 1364 * Translate ICMPv6 type and code to ICMPv4 (RFC7915). 1365 * NOTE: ICMPv6 echo handled by nat64_do_handle_ip6(). 1366 */ 1367 icmp6 = mtodo(m, hlen); 1368 mtu = 0; 1369 switch (icmp6->icmp6_type) { 1370 case ICMP6_DST_UNREACH: 1371 type = ICMP_UNREACH; 1372 switch (icmp6->icmp6_code) { 1373 case ICMP6_DST_UNREACH_NOROUTE: 1374 case ICMP6_DST_UNREACH_BEYONDSCOPE: 1375 case ICMP6_DST_UNREACH_ADDR: 1376 code = ICMP_UNREACH_HOST; 1377 break; 1378 case ICMP6_DST_UNREACH_ADMIN: 1379 code = ICMP_UNREACH_HOST_PROHIB; 1380 break; 1381 case ICMP6_DST_UNREACH_NOPORT: 1382 code = ICMP_UNREACH_PORT; 1383 break; 1384 default: 1385 DPRINTF(DP_DROPS, "Unsupported ICMPv6 type %d," 1386 " code %d", icmp6->icmp6_type, 1387 icmp6->icmp6_code); 1388 NAT64STAT_INC(&cfg->stats, dropped); 1389 return (NAT64MFREE); 1390 } 1391 break; 1392 case ICMP6_PACKET_TOO_BIG: 1393 type = ICMP_UNREACH; 1394 code = ICMP_UNREACH_NEEDFRAG; 1395 mtu = ntohl(icmp6->icmp6_mtu); 1396 if (mtu < IPV6_MMTU) { 1397 DPRINTF(DP_DROPS, "Wrong MTU %d in ICMPv6 type %d," 1398 " code %d", mtu, icmp6->icmp6_type, 1399 icmp6->icmp6_code); 1400 NAT64STAT_INC(&cfg->stats, dropped); 1401 return (NAT64MFREE); 1402 } 1403 /* 1404 * Adjust MTU to reflect difference between 1405 * IPv6 an IPv4 headers. 1406 */ 1407 mtu -= sizeof(struct ip6_hdr) - sizeof(struct ip); 1408 break; 1409 case ICMP6_TIME_EXCEEDED: 1410 type = ICMP_TIMXCEED; 1411 code = icmp6->icmp6_code; 1412 break; 1413 case ICMP6_PARAM_PROB: 1414 switch (icmp6->icmp6_code) { 1415 case ICMP6_PARAMPROB_HEADER: 1416 type = ICMP_PARAMPROB; 1417 code = ICMP_PARAMPROB_ERRATPTR; 1418 mtu = ntohl(icmp6->icmp6_pptr); 1419 switch (mtu) { 1420 case 0: /* Version/Traffic Class */ 1421 case 1: /* Traffic Class/Flow Label */ 1422 break; 1423 case 4: /* Payload Length */ 1424 case 5: 1425 mtu = 2; 1426 break; 1427 case 6: /* Next Header */ 1428 mtu = 9; 1429 break; 1430 case 7: /* Hop Limit */ 1431 mtu = 8; 1432 break; 1433 default: 1434 if (mtu >= 8 && mtu <= 23) { 1435 mtu = 12; /* Source address */ 1436 break; 1437 } 1438 if (mtu >= 24 && mtu <= 39) { 1439 mtu = 16; /* Destination address */ 1440 break; 1441 } 1442 DPRINTF(DP_DROPS, "Unsupported ICMPv6 type %d," 1443 " code %d, pptr %d", icmp6->icmp6_type, 1444 icmp6->icmp6_code, mtu); 1445 NAT64STAT_INC(&cfg->stats, dropped); 1446 return (NAT64MFREE); 1447 } 1448 case ICMP6_PARAMPROB_NEXTHEADER: 1449 type = ICMP_UNREACH; 1450 code = ICMP_UNREACH_PROTOCOL; 1451 break; 1452 default: 1453 DPRINTF(DP_DROPS, "Unsupported ICMPv6 type %d," 1454 " code %d, pptr %d", icmp6->icmp6_type, 1455 icmp6->icmp6_code, ntohl(icmp6->icmp6_pptr)); 1456 NAT64STAT_INC(&cfg->stats, dropped); 1457 return (NAT64MFREE); 1458 } 1459 break; 1460 default: 1461 DPRINTF(DP_DROPS, "Unsupported ICMPv6 type %d, code %d", 1462 icmp6->icmp6_type, icmp6->icmp6_code); 1463 NAT64STAT_INC(&cfg->stats, dropped); 1464 return (NAT64MFREE); 1465 } 1466 1467 hlen += sizeof(struct icmp6_hdr); 1468 if (m->m_pkthdr.len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) { 1469 NAT64STAT_INC(&cfg->stats, dropped); 1470 DPRINTF(DP_DROPS, "Message is too short %d", 1471 m->m_pkthdr.len); 1472 return (NAT64MFREE); 1473 } 1474 /* 1475 * We need at least ICMP_MINLEN bytes of original datagram payload 1476 * to generate ICMP message. It is nice that ICMP_MINLEN is equal 1477 * to sizeof(struct ip6_frag). So, if embedded datagram had a fragment 1478 * header we will not have to do m_pullup() again. 1479 * 1480 * What we have here: 1481 * Outer header: (IPv6iGW, v4mapPRefix+v4exthost) 1482 * Inner header: (v4mapPRefix+v4host, IPv6iHost) [sport, dport] 1483 * We need to translate it to: 1484 * 1485 * Outer header: (alias_host, v4exthost) 1486 * Inner header: (v4exthost, alias_host) [sport, alias_port] 1487 * 1488 * Assume caller function has checked if v4mapPRefix+v4host 1489 * matches configured prefix. 1490 * The only two things we should be provided with are mapping between 1491 * IPv6iHost <> alias_host and between dport and alias_port. 1492 */ 1493 if (m->m_len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) 1494 m = m_pullup(m, hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN); 1495 if (m == NULL) { 1496 NAT64STAT_INC(&cfg->stats, nomem); 1497 return (NAT64RETURN); 1498 } 1499 ip6 = mtod(m, struct ip6_hdr *); 1500 ip6i = mtodo(m, hlen); 1501 ip6f = NULL; 1502 proto = ip6i->ip6_nxt; 1503 plen = ntohs(ip6i->ip6_plen); 1504 hlen += sizeof(struct ip6_hdr); 1505 if (proto == IPPROTO_FRAGMENT) { 1506 if (m->m_pkthdr.len < hlen + sizeof(struct ip6_frag) + 1507 ICMP_MINLEN) 1508 goto fail; 1509 ip6f = mtodo(m, hlen); 1510 proto = ip6f->ip6f_nxt; 1511 plen -= sizeof(struct ip6_frag); 1512 hlen += sizeof(struct ip6_frag); 1513 /* Ajust MTU to reflect frag header size */ 1514 if (type == ICMP_UNREACH && code == ICMP_UNREACH_NEEDFRAG) 1515 mtu -= sizeof(struct ip6_frag); 1516 } 1517 if (proto != IPPROTO_TCP && proto != IPPROTO_UDP) { 1518 DPRINTF(DP_DROPS, "Unsupported proto %d in the inner header", 1519 proto); 1520 goto fail; 1521 } 1522 if (nat64_check_ip6(&ip6i->ip6_src) != 0 || 1523 nat64_check_ip6(&ip6i->ip6_dst) != 0) { 1524 DPRINTF(DP_DROPS, "Inner addresses do not passes the check"); 1525 goto fail; 1526 } 1527 /* Check if outer dst is the same as inner src */ 1528 if (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &ip6i->ip6_src)) { 1529 DPRINTF(DP_DROPS, "Inner src doesn't match outer dst"); 1530 goto fail; 1531 } 1532 1533 /* Now we need to make a fake IPv4 packet to generate ICMP message */ 1534 ip.ip_dst.s_addr = aaddr; 1535 ip.ip_src.s_addr = nat64_extract_ip4(&ip6i->ip6_src, cfg->plat_plen); 1536 if (ip.ip_src.s_addr == 0) 1537 goto fail; 1538 /* XXX: Make fake ulp header */ 1539 if (V_nat64out == &nat64_direct) /* init_ip4hdr will decrement it */ 1540 ip6i->ip6_hlim += IPV6_HLIMDEC; 1541 nat64_init_ip4hdr(ip6i, ip6f, plen, proto, &ip); 1542 m_adj(m, hlen - sizeof(struct ip)); 1543 bcopy(&ip, mtod(m, void *), sizeof(ip)); 1544 nat64_icmp_reflect(m, type, code, (uint16_t)mtu, &cfg->stats, 1545 logdata); 1546 return (NAT64RETURN); 1547 fail: 1548 /* 1549 * We must call m_freem() because mbuf pointer could be 1550 * changed with m_pullup(). 1551 */ 1552 m_freem(m); 1553 NAT64STAT_INC(&cfg->stats, dropped); 1554 return (NAT64RETURN); 1555 } 1556 1557 int 1558 nat64_do_handle_ip6(struct mbuf *m, uint32_t aaddr, uint16_t aport, 1559 struct nat64_config *cfg, void *logdata) 1560 { 1561 struct ip ip; 1562 struct nhop_object *nh; 1563 struct sockaddr_in dst; 1564 struct ip6_frag *frag; 1565 struct ip6_hdr *ip6; 1566 struct icmp6_hdr *icmp6; 1567 uint16_t *csum; 1568 int plen, hlen, proto; 1569 1570 /* 1571 * XXX: we expect ipfw_chk() did m_pullup() up to upper level 1572 * protocol's headers. Also we skip some checks, that ip6_input(), 1573 * ip6_forward(), ip6_fastfwd() and ipfw_chk() already did. 1574 */ 1575 ip6 = mtod(m, struct ip6_hdr *); 1576 if (nat64_check_ip6(&ip6->ip6_src) != 0 || 1577 nat64_check_ip6(&ip6->ip6_dst) != 0) { 1578 return (NAT64SKIP); 1579 } 1580 1581 /* Starting from this point we must not return zero */ 1582 ip.ip_src.s_addr = aaddr; 1583 if (nat64_check_ip4(ip.ip_src.s_addr) != 0) { 1584 DPRINTF(DP_GENERIC | DP_DROPS, "invalid source address: %08x", 1585 ip.ip_src.s_addr); 1586 NAT64STAT_INC(&cfg->stats, dropped); 1587 return (NAT64MFREE); 1588 } 1589 1590 ip.ip_dst.s_addr = nat64_extract_ip4(&ip6->ip6_dst, cfg->plat_plen); 1591 if (ip.ip_dst.s_addr == 0) { 1592 NAT64STAT_INC(&cfg->stats, dropped); 1593 return (NAT64MFREE); 1594 } 1595 1596 if (*V_nat64ip6stealth == 0 && ip6->ip6_hlim <= IPV6_HLIMDEC) { 1597 nat64_icmp6_reflect(m, ICMP6_TIME_EXCEEDED, 1598 ICMP6_TIME_EXCEED_TRANSIT, 0, &cfg->stats, logdata); 1599 return (NAT64RETURN); 1600 } 1601 1602 hlen = 0; 1603 plen = ntohs(ip6->ip6_plen); 1604 proto = nat64_getlasthdr(m, &hlen); 1605 if (proto < 0) { 1606 DPRINTF(DP_DROPS, "dropped due to mbuf isn't contigious"); 1607 NAT64STAT_INC(&cfg->stats, dropped); 1608 return (NAT64MFREE); 1609 } 1610 frag = NULL; 1611 if (proto == IPPROTO_FRAGMENT) { 1612 /* ipfw_chk should m_pullup up to frag header */ 1613 if (m->m_len < hlen + sizeof(*frag)) { 1614 DPRINTF(DP_DROPS, 1615 "dropped due to mbuf isn't contigious"); 1616 NAT64STAT_INC(&cfg->stats, dropped); 1617 return (NAT64MFREE); 1618 } 1619 frag = mtodo(m, hlen); 1620 proto = frag->ip6f_nxt; 1621 hlen += sizeof(*frag); 1622 /* Fragmented ICMPv6 is unsupported */ 1623 if (proto == IPPROTO_ICMPV6) { 1624 DPRINTF(DP_DROPS, "dropped due to fragmented ICMPv6"); 1625 NAT64STAT_INC(&cfg->stats, dropped); 1626 return (NAT64MFREE); 1627 } 1628 /* Fragment length must be multiple of 8 octets */ 1629 if ((frag->ip6f_offlg & IP6F_MORE_FRAG) != 0 && 1630 ((plen + sizeof(struct ip6_hdr) - hlen) & 0x7) != 0) { 1631 nat64_icmp6_reflect(m, ICMP6_PARAM_PROB, 1632 ICMP6_PARAMPROB_HEADER, 1633 offsetof(struct ip6_hdr, ip6_plen), &cfg->stats, 1634 logdata); 1635 return (NAT64RETURN); 1636 } 1637 } 1638 plen -= hlen - sizeof(struct ip6_hdr); 1639 if (plen < 0 || m->m_pkthdr.len < plen + hlen) { 1640 DPRINTF(DP_DROPS, "plen %d, pkthdr.len %d, hlen %d", 1641 plen, m->m_pkthdr.len, hlen); 1642 NAT64STAT_INC(&cfg->stats, dropped); 1643 return (NAT64MFREE); 1644 } 1645 1646 icmp6 = NULL; /* Make gcc happy */ 1647 if (proto == IPPROTO_ICMPV6) { 1648 icmp6 = mtodo(m, hlen); 1649 if (icmp6->icmp6_type != ICMP6_ECHO_REQUEST && 1650 icmp6->icmp6_type != ICMP6_ECHO_REPLY) 1651 return (nat64_handle_icmp6(m, hlen, aaddr, aport, 1652 cfg, logdata)); 1653 } 1654 dst.sin_addr.s_addr = ip.ip_dst.s_addr; 1655 nh = nat64_find_route4(&dst, m); 1656 if (nh == NULL) { 1657 NAT64STAT_INC(&cfg->stats, noroute4); 1658 nat64_icmp6_reflect(m, ICMP6_DST_UNREACH, 1659 ICMP6_DST_UNREACH_NOROUTE, 0, &cfg->stats, logdata); 1660 return (NAT64RETURN); 1661 } 1662 if (nh->nh_mtu < plen + sizeof(ip)) { 1663 nat64_icmp6_reflect(m, ICMP6_PACKET_TOO_BIG, 0, nh->nh_mtu, 1664 &cfg->stats, logdata); 1665 return (NAT64RETURN); 1666 } 1667 nat64_init_ip4hdr(ip6, frag, plen, proto, &ip); 1668 /* Convert checksums. */ 1669 switch (proto) { 1670 case IPPROTO_TCP: 1671 csum = &TCP(mtodo(m, hlen))->th_sum; 1672 if (aport != 0) { 1673 struct tcphdr *tcp = TCP(mtodo(m, hlen)); 1674 *csum = cksum_adjust(*csum, tcp->th_sport, aport); 1675 tcp->th_sport = aport; 1676 } 1677 *csum = cksum_add(*csum, nat64_cksum_convert(ip6, &ip)); 1678 break; 1679 case IPPROTO_UDP: 1680 csum = &UDP(mtodo(m, hlen))->uh_sum; 1681 if (aport != 0) { 1682 struct udphdr *udp = UDP(mtodo(m, hlen)); 1683 *csum = cksum_adjust(*csum, udp->uh_sport, aport); 1684 udp->uh_sport = aport; 1685 } 1686 *csum = cksum_add(*csum, nat64_cksum_convert(ip6, &ip)); 1687 break; 1688 case IPPROTO_ICMPV6: 1689 /* Checksum in ICMPv6 covers pseudo header */ 1690 csum = &icmp6->icmp6_cksum; 1691 *csum = cksum_add(*csum, in6_cksum_pseudo(ip6, plen, 1692 IPPROTO_ICMPV6, 0)); 1693 /* Convert ICMPv6 types to ICMP */ 1694 proto = *(uint16_t *)icmp6; /* save old word for cksum_adjust */ 1695 if (icmp6->icmp6_type == ICMP6_ECHO_REQUEST) 1696 icmp6->icmp6_type = ICMP_ECHO; 1697 else /* ICMP6_ECHO_REPLY */ 1698 icmp6->icmp6_type = ICMP_ECHOREPLY; 1699 *csum = cksum_adjust(*csum, (uint16_t)proto, 1700 *(uint16_t *)icmp6); 1701 if (aport != 0) { 1702 uint16_t old_id = icmp6->icmp6_id; 1703 icmp6->icmp6_id = aport; 1704 *csum = cksum_adjust(*csum, old_id, aport); 1705 } 1706 break; 1707 }; 1708 1709 m_adj(m, hlen - sizeof(ip)); 1710 bcopy(&ip, mtod(m, void *), sizeof(ip)); 1711 if (V_nat64out->output(nh->nh_ifp, m, (struct sockaddr *)&dst, 1712 &cfg->stats, logdata) == 0) 1713 NAT64STAT_INC(&cfg->stats, opcnt64); 1714 return (NAT64RETURN); 1715 } 1716 1717