1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. 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 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipfw.h" 69 #include "opt_ipsec.h" 70 #include "opt_route.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/malloc.h> 75 #include <sys/mbuf.h> 76 #include <sys/proc.h> 77 #include <sys/domain.h> 78 #include <sys/protosw.h> 79 #include <sys/socket.h> 80 #include <sys/socketvar.h> 81 #include <sys/errno.h> 82 #include <sys/time.h> 83 #include <sys/kernel.h> 84 #include <sys/syslog.h> 85 86 #include <net/if.h> 87 #include <net/if_types.h> 88 #include <net/if_dl.h> 89 #include <net/route.h> 90 #include <net/netisr.h> 91 #include <net/pfil.h> 92 #include <net/vnet.h> 93 94 #include <netinet/in.h> 95 #include <netinet/ip_var.h> 96 #include <netinet/in_systm.h> 97 #include <net/if_llatbl.h> 98 #ifdef INET 99 #include <netinet/ip.h> 100 #include <netinet/ip_icmp.h> 101 #endif /* INET */ 102 #include <netinet/ip6.h> 103 #include <netinet6/in6_var.h> 104 #include <netinet6/ip6_var.h> 105 #include <netinet/in_pcb.h> 106 #include <netinet/icmp6.h> 107 #include <netinet6/scope6_var.h> 108 #include <netinet6/in6_ifattach.h> 109 #include <netinet6/nd6.h> 110 111 #ifdef IPSEC 112 #include <netipsec/ipsec.h> 113 #include <netinet6/ip6_ipsec.h> 114 #include <netipsec/ipsec6.h> 115 #endif /* IPSEC */ 116 117 #include <netinet6/ip6protosw.h> 118 119 #ifdef FLOWTABLE 120 #include <net/flowtable.h> 121 VNET_DECLARE(int, ip6_output_flowtable_size); 122 #define V_ip6_output_flowtable_size VNET(ip6_output_flowtable_size) 123 #endif 124 125 extern struct domain inet6domain; 126 127 u_char ip6_protox[IPPROTO_MAX]; 128 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); 129 130 static struct netisr_handler ip6_nh = { 131 .nh_name = "ip6", 132 .nh_handler = ip6_input, 133 .nh_proto = NETISR_IPV6, 134 .nh_policy = NETISR_POLICY_FLOW, 135 }; 136 137 VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch); 138 #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch) 139 140 VNET_DEFINE(struct pfil_head, inet6_pfil_hook); 141 142 VNET_DEFINE(struct ip6stat, ip6stat); 143 144 struct rwlock in6_ifaddr_lock; 145 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); 146 147 static void ip6_init2(void *); 148 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); 149 static struct ip6aux *ip6_addaux(struct mbuf *); 150 static struct ip6aux *ip6_findaux(struct mbuf *m); 151 static void ip6_delaux (struct mbuf *); 152 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 153 #ifdef PULLDOWN_TEST 154 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 155 #endif 156 157 /* 158 * IP6 initialization: fill in IP6 protocol switch table. 159 * All protocols not implemented in kernel go to raw IP6 protocol handler. 160 */ 161 void 162 ip6_init(void) 163 { 164 struct ip6protosw *pr; 165 int i; 166 167 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 168 &V_ip6_auto_linklocal); 169 TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv); 170 TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr); 171 172 TAILQ_INIT(&V_in6_ifaddrhead); 173 174 /* Initialize packet filter hooks. */ 175 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 176 V_inet6_pfil_hook.ph_af = AF_INET6; 177 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0) 178 printf("%s: WARNING: unable to register pfil hook, " 179 "error %d\n", __func__, i); 180 181 scope6_init(); 182 addrsel_policy_init(); 183 nd6_init(); 184 frag6_init(); 185 186 #ifdef FLOWTABLE 187 if (TUNABLE_INT_FETCH("net.inet6.ip6.output_flowtable_size", 188 &V_ip6_output_flowtable_size)) { 189 if (V_ip6_output_flowtable_size < 256) 190 V_ip6_output_flowtable_size = 256; 191 if (!powerof2(V_ip6_output_flowtable_size)) { 192 printf("flowtable must be power of 2 size\n"); 193 V_ip6_output_flowtable_size = 2048; 194 } 195 } else { 196 /* 197 * round up to the next power of 2 198 */ 199 V_ip6_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1); 200 } 201 V_ip6_ft = flowtable_alloc("ipv6", V_ip6_output_flowtable_size, FL_IPV6|FL_PCPU); 202 #endif 203 204 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 205 206 /* Skip global initialization stuff for non-default instances. */ 207 if (!IS_DEFAULT_VNET(curvnet)) 208 return; 209 210 #ifdef DIAGNOSTIC 211 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 212 panic("sizeof(protosw) != sizeof(ip6protosw)"); 213 #endif 214 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 215 if (pr == NULL) 216 panic("ip6_init"); 217 218 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 219 for (i = 0; i < IPPROTO_MAX; i++) 220 ip6_protox[i] = pr - inet6sw; 221 /* 222 * Cycle through IP protocols and put them into the appropriate place 223 * in ip6_protox[]. 224 */ 225 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 226 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 227 if (pr->pr_domain->dom_family == PF_INET6 && 228 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 229 /* Be careful to only index valid IP protocols. */ 230 if (pr->pr_protocol < IPPROTO_MAX) 231 ip6_protox[pr->pr_protocol] = pr - inet6sw; 232 } 233 234 netisr_register(&ip6_nh); 235 } 236 237 /* 238 * The protocol to be inserted into ip6_protox[] must be already registered 239 * in inet6sw[], either statically or through pf_proto_register(). 240 */ 241 int 242 ip6proto_register(short ip6proto) 243 { 244 struct ip6protosw *pr; 245 246 /* Sanity checks. */ 247 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX) 248 return (EPROTONOSUPPORT); 249 250 /* 251 * The protocol slot must not be occupied by another protocol 252 * already. An index pointing to IPPROTO_RAW is unused. 253 */ 254 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 255 if (pr == NULL) 256 return (EPFNOSUPPORT); 257 if (ip6_protox[ip6proto] != pr - inet6sw) /* IPPROTO_RAW */ 258 return (EEXIST); 259 260 /* 261 * Find the protocol position in inet6sw[] and set the index. 262 */ 263 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 264 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) { 265 if (pr->pr_domain->dom_family == PF_INET6 && 266 pr->pr_protocol && pr->pr_protocol == ip6proto) { 267 ip6_protox[pr->pr_protocol] = pr - inet6sw; 268 return (0); 269 } 270 } 271 return (EPROTONOSUPPORT); 272 } 273 274 int 275 ip6proto_unregister(short ip6proto) 276 { 277 struct ip6protosw *pr; 278 279 /* Sanity checks. */ 280 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX) 281 return (EPROTONOSUPPORT); 282 283 /* Check if the protocol was indeed registered. */ 284 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 285 if (pr == NULL) 286 return (EPFNOSUPPORT); 287 if (ip6_protox[ip6proto] == pr - inet6sw) /* IPPROTO_RAW */ 288 return (ENOENT); 289 290 /* Reset the protocol slot to IPPROTO_RAW. */ 291 ip6_protox[ip6proto] = pr - inet6sw; 292 return (0); 293 } 294 295 #ifdef VIMAGE 296 void 297 ip6_destroy() 298 { 299 300 nd6_destroy(); 301 callout_drain(&V_in6_tmpaddrtimer_ch); 302 } 303 #endif 304 305 static int 306 ip6_init2_vnet(const void *unused __unused) 307 { 308 309 /* nd6_timer_init */ 310 callout_init(&V_nd6_timer_ch, 0); 311 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); 312 313 /* timer for regeneranation of temporary addresses randomize ID */ 314 callout_init(&V_in6_tmpaddrtimer_ch, 0); 315 callout_reset(&V_in6_tmpaddrtimer_ch, 316 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 317 V_ip6_temp_regen_advance) * hz, 318 in6_tmpaddrtimer, curvnet); 319 320 return (0); 321 } 322 323 static void 324 ip6_init2(void *dummy) 325 { 326 327 ip6_init2_vnet(NULL); 328 } 329 330 /* cheat */ 331 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 332 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 333 334 static int 335 ip6_input_hbh(struct mbuf *m, uint32_t *plen, uint32_t *rtalert, int *off, 336 int *nxt, int *ours) 337 { 338 struct ip6_hdr *ip6; 339 struct ip6_hbh *hbh; 340 341 if (ip6_hopopts_input(plen, rtalert, &m, off)) { 342 #if 0 /*touches NULL pointer*/ 343 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 344 #endif 345 goto out; /* m have already been freed */ 346 } 347 348 /* adjust pointer */ 349 ip6 = mtod(m, struct ip6_hdr *); 350 351 /* 352 * if the payload length field is 0 and the next header field 353 * indicates Hop-by-Hop Options header, then a Jumbo Payload 354 * option MUST be included. 355 */ 356 if (ip6->ip6_plen == 0 && *plen == 0) { 357 /* 358 * Note that if a valid jumbo payload option is 359 * contained, ip6_hopopts_input() must set a valid 360 * (non-zero) payload length to the variable plen. 361 */ 362 V_ip6stat.ip6s_badoptions++; 363 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 364 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 365 icmp6_error(m, ICMP6_PARAM_PROB, 366 ICMP6_PARAMPROB_HEADER, 367 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 368 goto out; 369 } 370 #ifndef PULLDOWN_TEST 371 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 372 hbh = (struct ip6_hbh *)(ip6 + 1); 373 #else 374 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 375 sizeof(struct ip6_hbh)); 376 if (hbh == NULL) { 377 V_ip6stat.ip6s_tooshort++; 378 goto out; 379 } 380 #endif 381 *nxt = hbh->ip6h_nxt; 382 383 /* 384 * If we are acting as a router and the packet contains a 385 * router alert option, see if we know the option value. 386 * Currently, we only support the option value for MLD, in which 387 * case we should pass the packet to the multicast routing 388 * daemon. 389 */ 390 if (*rtalert != ~0) { 391 switch (*rtalert) { 392 case IP6OPT_RTALERT_MLD: 393 if (V_ip6_forwarding) 394 *ours = 1; 395 break; 396 default: 397 /* 398 * RFC2711 requires unrecognized values must be 399 * silently ignored. 400 */ 401 break; 402 } 403 } 404 405 return (0); 406 407 out: 408 return (1); 409 } 410 411 void 412 ip6_input(struct mbuf *m) 413 { 414 struct ip6_hdr *ip6; 415 int off = sizeof(struct ip6_hdr), nest; 416 u_int32_t plen; 417 u_int32_t rtalert = ~0; 418 int nxt, ours = 0; 419 struct ifnet *deliverifp = NULL, *ifp = NULL; 420 struct in6_addr odst; 421 struct route_in6 rin6; 422 int srcrt = 0; 423 struct llentry *lle = NULL; 424 struct sockaddr_in6 dst6, *dst; 425 426 bzero(&rin6, sizeof(struct route_in6)); 427 #ifdef IPSEC 428 /* 429 * should the inner packet be considered authentic? 430 * see comment in ah4_input(). 431 * NB: m cannot be NULL when passed to the input routine 432 */ 433 434 m->m_flags &= ~M_AUTHIPHDR; 435 m->m_flags &= ~M_AUTHIPDGM; 436 437 #endif /* IPSEC */ 438 439 /* 440 * make sure we don't have onion peering information into m_tag. 441 */ 442 ip6_delaux(m); 443 444 if (m->m_flags & M_FASTFWD_OURS) { 445 /* 446 * Firewall changed destination to local. 447 */ 448 m->m_flags &= ~M_FASTFWD_OURS; 449 ours = 1; 450 deliverifp = m->m_pkthdr.rcvif; 451 ip6 = mtod(m, struct ip6_hdr *); 452 goto hbhcheck; 453 } 454 455 /* 456 * mbuf statistics 457 */ 458 if (m->m_flags & M_EXT) { 459 if (m->m_next) 460 V_ip6stat.ip6s_mext2m++; 461 else 462 V_ip6stat.ip6s_mext1++; 463 } else { 464 #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) 465 if (m->m_next) { 466 if (m->m_flags & M_LOOP) { 467 V_ip6stat.ip6s_m2m[V_loif->if_index]++; 468 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 469 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 470 else 471 V_ip6stat.ip6s_m2m[0]++; 472 } else 473 V_ip6stat.ip6s_m1++; 474 #undef M2MMAX 475 } 476 477 /* drop the packet if IPv6 operation is disabled on the IF */ 478 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { 479 m_freem(m); 480 return; 481 } 482 483 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 484 V_ip6stat.ip6s_total++; 485 486 #ifndef PULLDOWN_TEST 487 /* 488 * L2 bridge code and some other code can return mbuf chain 489 * that does not conform to KAME requirement. too bad. 490 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 491 */ 492 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 493 struct mbuf *n; 494 495 MGETHDR(n, M_DONTWAIT, MT_HEADER); 496 if (n) 497 M_MOVE_PKTHDR(n, m); 498 if (n && n->m_pkthdr.len > MHLEN) { 499 MCLGET(n, M_DONTWAIT); 500 if ((n->m_flags & M_EXT) == 0) { 501 m_freem(n); 502 n = NULL; 503 } 504 } 505 if (n == NULL) { 506 m_freem(m); 507 return; /* ENOBUFS */ 508 } 509 510 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 511 n->m_len = n->m_pkthdr.len; 512 m_freem(m); 513 m = n; 514 } 515 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 516 #endif 517 518 if (m->m_len < sizeof(struct ip6_hdr)) { 519 struct ifnet *inifp; 520 inifp = m->m_pkthdr.rcvif; 521 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 522 V_ip6stat.ip6s_toosmall++; 523 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 524 return; 525 } 526 } 527 528 ip6 = mtod(m, struct ip6_hdr *); 529 530 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 531 V_ip6stat.ip6s_badvers++; 532 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 533 goto bad; 534 } 535 536 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 537 538 /* 539 * Check against address spoofing/corruption. 540 */ 541 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 542 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 543 /* 544 * XXX: "badscope" is not very suitable for a multicast source. 545 */ 546 V_ip6stat.ip6s_badscope++; 547 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 548 goto bad; 549 } 550 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 551 !(m->m_flags & M_LOOP)) { 552 /* 553 * In this case, the packet should come from the loopback 554 * interface. However, we cannot just check the if_flags, 555 * because ip6_mloopback() passes the "actual" interface 556 * as the outgoing/incoming interface. 557 */ 558 V_ip6stat.ip6s_badscope++; 559 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 560 goto bad; 561 } 562 563 #ifdef ALTQ 564 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 565 /* packet is dropped by traffic conditioner */ 566 return; 567 } 568 #endif 569 /* 570 * The following check is not documented in specs. A malicious 571 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 572 * and bypass security checks (act as if it was from 127.0.0.1 by using 573 * IPv6 src ::ffff:127.0.0.1). Be cautious. 574 * 575 * This check chokes if we are in an SIIT cloud. As none of BSDs 576 * support IPv4-less kernel compilation, we cannot support SIIT 577 * environment at all. So, it makes more sense for us to reject any 578 * malicious packets for non-SIIT environment, than try to do a 579 * partial support for SIIT environment. 580 */ 581 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 582 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 583 V_ip6stat.ip6s_badscope++; 584 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 585 goto bad; 586 } 587 #if 0 588 /* 589 * Reject packets with IPv4 compatible addresses (auto tunnel). 590 * 591 * The code forbids auto tunnel relay case in RFC1933 (the check is 592 * stronger than RFC1933). We may want to re-enable it if mech-xx 593 * is revised to forbid relaying case. 594 */ 595 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 596 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 597 V_ip6stat.ip6s_badscope++; 598 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 599 goto bad; 600 } 601 #endif 602 #ifdef IPSEC 603 /* 604 * Bypass packet filtering for packets previously handled by IPsec. 605 */ 606 if (ip6_ipsec_filtertunnel(m)) 607 goto passin; 608 #endif /* IPSEC */ 609 610 /* 611 * Run through list of hooks for input packets. 612 * 613 * NB: Beware of the destination address changing 614 * (e.g. by NAT rewriting). When this happens, 615 * tell ip6_forward to do the right thing. 616 */ 617 odst = ip6->ip6_dst; 618 619 /* Jump over all PFIL processing if hooks are not active. */ 620 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 621 goto passin; 622 623 if (pfil_run_hooks(&V_inet6_pfil_hook, &m, 624 m->m_pkthdr.rcvif, PFIL_IN, NULL)) 625 return; 626 if (m == NULL) /* consumed by filter */ 627 return; 628 ip6 = mtod(m, struct ip6_hdr *); 629 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 630 631 #ifdef IPFIREWALL_FORWARD 632 if (m->m_flags & M_FASTFWD_OURS) { 633 m->m_flags &= ~M_FASTFWD_OURS; 634 ours = 1; 635 deliverifp = m->m_pkthdr.rcvif; 636 goto hbhcheck; 637 } 638 if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) { 639 /* 640 * Directly ship the packet on. This allows forwarding 641 * packets originally destined to us to some other directly 642 * connected host. 643 */ 644 ip6_forward(m, 1); 645 goto out; 646 } 647 #endif /* IPFIREWALL_FORWARD */ 648 649 passin: 650 /* 651 * Disambiguate address scope zones (if there is ambiguity). 652 * We first make sure that the original source or destination address 653 * is not in our internal form for scoped addresses. Such addresses 654 * are not necessarily invalid spec-wise, but we cannot accept them due 655 * to the usage conflict. 656 * in6_setscope() then also checks and rejects the cases where src or 657 * dst are the loopback address and the receiving interface 658 * is not loopback. 659 */ 660 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 661 V_ip6stat.ip6s_badscope++; /* XXX */ 662 goto bad; 663 } 664 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 665 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 666 V_ip6stat.ip6s_badscope++; 667 goto bad; 668 } 669 670 /* 671 * Multicast check. Assume packet is for us to avoid 672 * prematurely taking locks. 673 */ 674 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 675 ours = 1; 676 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 677 deliverifp = m->m_pkthdr.rcvif; 678 goto hbhcheck; 679 } 680 681 /* 682 * Unicast check 683 */ 684 685 bzero(&dst6, sizeof(dst6)); 686 dst6.sin6_family = AF_INET6; 687 dst6.sin6_len = sizeof(struct sockaddr_in6); 688 dst6.sin6_addr = ip6->ip6_dst; 689 ifp = m->m_pkthdr.rcvif; 690 IF_AFDATA_LOCK(ifp); 691 lle = lla_lookup(LLTABLE6(ifp), 0, 692 (struct sockaddr *)&dst6); 693 IF_AFDATA_UNLOCK(ifp); 694 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { 695 struct ifaddr *ifa; 696 struct in6_ifaddr *ia6; 697 int bad; 698 699 bad = 1; 700 #define sa_equal(a1, a2) \ 701 (bcmp((a1), (a2), ((a1))->sin6_len) == 0) 702 IF_ADDR_RLOCK(ifp); 703 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 704 if (ifa->ifa_addr->sa_family != dst6.sin6_family) 705 continue; 706 if (sa_equal(&dst6, ifa->ifa_addr)) 707 break; 708 } 709 KASSERT(ifa != NULL, ("%s: ifa not found for lle %p", 710 __func__, lle)); 711 #undef sa_equal 712 713 ia6 = (struct in6_ifaddr *)ifa; 714 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 715 /* Count the packet in the ip address stats */ 716 ia6->ia_ifa.if_ipackets++; 717 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 718 719 /* 720 * record address information into m_tag. 721 */ 722 (void)ip6_setdstifaddr(m, ia6); 723 724 bad = 0; 725 } else { 726 char ip6bufs[INET6_ADDRSTRLEN]; 727 char ip6bufd[INET6_ADDRSTRLEN]; 728 /* address is not ready, so discard the packet. */ 729 nd6log((LOG_INFO, 730 "ip6_input: packet to an unready address %s->%s\n", 731 ip6_sprintf(ip6bufs, &ip6->ip6_src), 732 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 733 } 734 IF_ADDR_RUNLOCK(ifp); 735 LLE_RUNLOCK(lle); 736 if (bad) 737 goto bad; 738 else { 739 ours = 1; 740 deliverifp = ifp; 741 goto hbhcheck; 742 } 743 } 744 if (lle != NULL) 745 LLE_RUNLOCK(lle); 746 747 dst = &rin6.ro_dst; 748 dst->sin6_len = sizeof(struct sockaddr_in6); 749 dst->sin6_family = AF_INET6; 750 dst->sin6_addr = ip6->ip6_dst; 751 rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m)); 752 if (rin6.ro_rt) 753 RT_UNLOCK(rin6.ro_rt); 754 755 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 756 757 /* 758 * Accept the packet if the forwarding interface to the destination 759 * according to the routing table is the loopback interface, 760 * unless the associated route has a gateway. 761 * Note that this approach causes to accept a packet if there is a 762 * route to the loopback interface for the destination of the packet. 763 * But we think it's even useful in some situations, e.g. when using 764 * a special daemon which wants to intercept the packet. 765 * 766 * XXX: some OSes automatically make a cloned route for the destination 767 * of an outgoing packet. If the outgoing interface of the packet 768 * is a loopback one, the kernel would consider the packet to be 769 * accepted, even if we have no such address assinged on the interface. 770 * We check the cloned flag of the route entry to reject such cases, 771 * assuming that route entries for our own addresses are not made by 772 * cloning (it should be true because in6_addloop explicitly installs 773 * the host route). However, we might have to do an explicit check 774 * while it would be less efficient. Or, should we rather install a 775 * reject route for such a case? 776 */ 777 if (rin6.ro_rt && 778 (rin6.ro_rt->rt_flags & 779 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 780 #ifdef RTF_WASCLONED 781 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) && 782 #endif 783 #ifdef RTF_CLONED 784 !(rin6.ro_rt->rt_flags & RTF_CLONED) && 785 #endif 786 #if 0 787 /* 788 * The check below is redundant since the comparison of 789 * the destination and the key of the rtentry has 790 * already done through looking up the routing table. 791 */ 792 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 793 &rt6_key(rin6.ro_rt)->sin6_addr) 794 #endif 795 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) { 796 int free_ia6 = 0; 797 struct in6_ifaddr *ia6; 798 799 /* 800 * found the loopback route to the interface address 801 */ 802 if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) { 803 struct sockaddr_in6 dest6; 804 805 bzero(&dest6, sizeof(dest6)); 806 dest6.sin6_family = AF_INET6; 807 dest6.sin6_len = sizeof(dest6); 808 dest6.sin6_addr = ip6->ip6_dst; 809 ia6 = (struct in6_ifaddr *) 810 ifa_ifwithaddr((struct sockaddr *)&dest6); 811 if (ia6 == NULL) 812 goto bad; 813 free_ia6 = 1; 814 } 815 else 816 ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa; 817 818 /* 819 * record address information into m_tag. 820 */ 821 (void)ip6_setdstifaddr(m, ia6); 822 823 /* 824 * packets to a tentative, duplicated, or somehow invalid 825 * address must not be accepted. 826 */ 827 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 828 /* this address is ready */ 829 ours = 1; 830 deliverifp = ia6->ia_ifp; /* correct? */ 831 /* Count the packet in the ip address stats */ 832 ia6->ia_ifa.if_ipackets++; 833 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 834 if (ia6 != NULL && free_ia6 != 0) 835 ifa_free(&ia6->ia_ifa); 836 goto hbhcheck; 837 } else { 838 char ip6bufs[INET6_ADDRSTRLEN]; 839 char ip6bufd[INET6_ADDRSTRLEN]; 840 /* address is not ready, so discard the packet. */ 841 nd6log((LOG_INFO, 842 "ip6_input: packet to an unready address %s->%s\n", 843 ip6_sprintf(ip6bufs, &ip6->ip6_src), 844 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 845 846 if (ia6 != NULL && free_ia6 != 0) 847 ifa_free(&ia6->ia_ifa); 848 goto bad; 849 } 850 } 851 852 /* 853 * FAITH (Firewall Aided Internet Translator) 854 */ 855 if (V_ip6_keepfaith) { 856 if (rin6.ro_rt && rin6.ro_rt->rt_ifp && 857 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) { 858 /* XXX do we need more sanity checks? */ 859 ours = 1; 860 deliverifp = rin6.ro_rt->rt_ifp; /* faith */ 861 goto hbhcheck; 862 } 863 } 864 865 /* 866 * Now there is no reason to process the packet if it's not our own 867 * and we're not a router. 868 */ 869 if (!V_ip6_forwarding) { 870 V_ip6stat.ip6s_cantforward++; 871 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 872 goto bad; 873 } 874 875 hbhcheck: 876 /* 877 * record address information into m_tag, if we don't have one yet. 878 * note that we are unable to record it, if the address is not listed 879 * as our interface address (e.g. multicast addresses, addresses 880 * within FAITH prefixes and such). 881 */ 882 if (deliverifp && !ip6_getdstifaddr(m)) { 883 struct in6_ifaddr *ia6; 884 885 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 886 if (ia6) { 887 if (!ip6_setdstifaddr(m, ia6)) { 888 /* 889 * XXX maybe we should drop the packet here, 890 * as we could not provide enough information 891 * to the upper layers. 892 */ 893 } 894 ifa_free(&ia6->ia_ifa); 895 } 896 } 897 898 /* 899 * Process Hop-by-Hop options header if it's contained. 900 * m may be modified in ip6_hopopts_input(). 901 * If a JumboPayload option is included, plen will also be modified. 902 */ 903 plen = (u_int32_t)ntohs(ip6->ip6_plen); 904 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 905 int error; 906 907 error = ip6_input_hbh(m, &plen, &rtalert, &off, &nxt, &ours); 908 if (error != 0) 909 goto out; 910 } else 911 nxt = ip6->ip6_nxt; 912 913 /* 914 * Check that the amount of data in the buffers 915 * is as at least much as the IPv6 header would have us expect. 916 * Trim mbufs if longer than we expect. 917 * Drop packet if shorter than we expect. 918 */ 919 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 920 V_ip6stat.ip6s_tooshort++; 921 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 922 goto bad; 923 } 924 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 925 if (m->m_len == m->m_pkthdr.len) { 926 m->m_len = sizeof(struct ip6_hdr) + plen; 927 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 928 } else 929 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 930 } 931 932 /* 933 * Forward if desirable. 934 */ 935 if (V_ip6_mrouter && 936 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 937 /* 938 * If we are acting as a multicast router, all 939 * incoming multicast packets are passed to the 940 * kernel-level multicast forwarding function. 941 * The packet is returned (relatively) intact; if 942 * ip6_mforward() returns a non-zero value, the packet 943 * must be discarded, else it may be accepted below. 944 * 945 * XXX TODO: Check hlim and multicast scope here to avoid 946 * unnecessarily calling into ip6_mforward(). 947 */ 948 if (ip6_mforward && 949 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 950 IP6STAT_INC(ip6s_cantforward); 951 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 952 goto bad; 953 } 954 } else if (!ours) { 955 ip6_forward(m, srcrt); 956 goto out; 957 } 958 959 ip6 = mtod(m, struct ip6_hdr *); 960 961 /* 962 * Malicious party may be able to use IPv4 mapped addr to confuse 963 * tcp/udp stack and bypass security checks (act as if it was from 964 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 965 * 966 * For SIIT end node behavior, you may want to disable the check. 967 * However, you will become vulnerable to attacks using IPv4 mapped 968 * source. 969 */ 970 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 971 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 972 V_ip6stat.ip6s_badscope++; 973 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 974 goto bad; 975 } 976 977 /* 978 * Tell launch routine the next header 979 */ 980 V_ip6stat.ip6s_delivered++; 981 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 982 nest = 0; 983 984 while (nxt != IPPROTO_DONE) { 985 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 986 V_ip6stat.ip6s_toomanyhdr++; 987 goto bad; 988 } 989 990 /* 991 * protection against faulty packet - there should be 992 * more sanity checks in header chain processing. 993 */ 994 if (m->m_pkthdr.len < off) { 995 V_ip6stat.ip6s_tooshort++; 996 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 997 goto bad; 998 } 999 1000 #ifdef IPSEC 1001 /* 1002 * enforce IPsec policy checking if we are seeing last header. 1003 * note that we do not visit this with protocols with pcb layer 1004 * code - like udp/tcp/raw ip. 1005 */ 1006 if (ip6_ipsec_input(m, nxt)) 1007 goto bad; 1008 #endif /* IPSEC */ 1009 1010 /* 1011 * Use mbuf flags to propagate Router Alert option to 1012 * ICMPv6 layer, as hop-by-hop options have been stripped. 1013 */ 1014 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 1015 m->m_flags |= M_RTALERT_MLD; 1016 1017 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 1018 } 1019 goto out; 1020 bad: 1021 m_freem(m); 1022 out: 1023 if (rin6.ro_rt) 1024 RTFREE(rin6.ro_rt); 1025 } 1026 1027 /* 1028 * set/grab in6_ifaddr correspond to IPv6 destination address. 1029 * XXX backward compatibility wrapper 1030 * 1031 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag, 1032 * and then bump it when the tag is copied, and release it when the tag is 1033 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead 1034 * we just bump the ia refcount when we receive it. This should be fixed. 1035 */ 1036 static struct ip6aux * 1037 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 1038 { 1039 struct ip6aux *ip6a; 1040 1041 ip6a = ip6_addaux(m); 1042 if (ip6a) 1043 ip6a->ip6a_dstia6 = ia6; 1044 return ip6a; /* NULL if failed to set */ 1045 } 1046 1047 struct in6_ifaddr * 1048 ip6_getdstifaddr(struct mbuf *m) 1049 { 1050 struct ip6aux *ip6a; 1051 struct in6_ifaddr *ia; 1052 1053 ip6a = ip6_findaux(m); 1054 if (ip6a) { 1055 ia = ip6a->ip6a_dstia6; 1056 ifa_ref(&ia->ia_ifa); 1057 return ia; 1058 } else 1059 return NULL; 1060 } 1061 1062 /* 1063 * Hop-by-Hop options header processing. If a valid jumbo payload option is 1064 * included, the real payload length will be stored in plenp. 1065 * 1066 * rtalertp - XXX: should be stored more smart way 1067 */ 1068 static int 1069 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 1070 struct mbuf **mp, int *offp) 1071 { 1072 struct mbuf *m = *mp; 1073 int off = *offp, hbhlen; 1074 struct ip6_hbh *hbh; 1075 u_int8_t *opt; 1076 1077 /* validation of the length of the header */ 1078 #ifndef PULLDOWN_TEST 1079 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 1080 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 1081 hbhlen = (hbh->ip6h_len + 1) << 3; 1082 1083 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 1084 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 1085 #else 1086 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 1087 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 1088 if (hbh == NULL) { 1089 V_ip6stat.ip6s_tooshort++; 1090 return -1; 1091 } 1092 hbhlen = (hbh->ip6h_len + 1) << 3; 1093 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 1094 hbhlen); 1095 if (hbh == NULL) { 1096 V_ip6stat.ip6s_tooshort++; 1097 return -1; 1098 } 1099 #endif 1100 off += hbhlen; 1101 hbhlen -= sizeof(struct ip6_hbh); 1102 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 1103 1104 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 1105 hbhlen, rtalertp, plenp) < 0) 1106 return (-1); 1107 1108 *offp = off; 1109 *mp = m; 1110 return (0); 1111 } 1112 1113 /* 1114 * Search header for all Hop-by-hop options and process each option. 1115 * This function is separate from ip6_hopopts_input() in order to 1116 * handle a case where the sending node itself process its hop-by-hop 1117 * options header. In such a case, the function is called from ip6_output(). 1118 * 1119 * The function assumes that hbh header is located right after the IPv6 header 1120 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 1121 * opthead + hbhlen is located in contiguous memory region. 1122 */ 1123 int 1124 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 1125 u_int32_t *rtalertp, u_int32_t *plenp) 1126 { 1127 struct ip6_hdr *ip6; 1128 int optlen = 0; 1129 u_int8_t *opt = opthead; 1130 u_int16_t rtalert_val; 1131 u_int32_t jumboplen; 1132 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 1133 1134 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 1135 switch (*opt) { 1136 case IP6OPT_PAD1: 1137 optlen = 1; 1138 break; 1139 case IP6OPT_PADN: 1140 if (hbhlen < IP6OPT_MINLEN) { 1141 V_ip6stat.ip6s_toosmall++; 1142 goto bad; 1143 } 1144 optlen = *(opt + 1) + 2; 1145 break; 1146 case IP6OPT_ROUTER_ALERT: 1147 /* XXX may need check for alignment */ 1148 if (hbhlen < IP6OPT_RTALERT_LEN) { 1149 V_ip6stat.ip6s_toosmall++; 1150 goto bad; 1151 } 1152 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 1153 /* XXX stat */ 1154 icmp6_error(m, ICMP6_PARAM_PROB, 1155 ICMP6_PARAMPROB_HEADER, 1156 erroff + opt + 1 - opthead); 1157 return (-1); 1158 } 1159 optlen = IP6OPT_RTALERT_LEN; 1160 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1161 *rtalertp = ntohs(rtalert_val); 1162 break; 1163 case IP6OPT_JUMBO: 1164 /* XXX may need check for alignment */ 1165 if (hbhlen < IP6OPT_JUMBO_LEN) { 1166 V_ip6stat.ip6s_toosmall++; 1167 goto bad; 1168 } 1169 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1170 /* XXX stat */ 1171 icmp6_error(m, ICMP6_PARAM_PROB, 1172 ICMP6_PARAMPROB_HEADER, 1173 erroff + opt + 1 - opthead); 1174 return (-1); 1175 } 1176 optlen = IP6OPT_JUMBO_LEN; 1177 1178 /* 1179 * IPv6 packets that have non 0 payload length 1180 * must not contain a jumbo payload option. 1181 */ 1182 ip6 = mtod(m, struct ip6_hdr *); 1183 if (ip6->ip6_plen) { 1184 V_ip6stat.ip6s_badoptions++; 1185 icmp6_error(m, ICMP6_PARAM_PROB, 1186 ICMP6_PARAMPROB_HEADER, 1187 erroff + opt - opthead); 1188 return (-1); 1189 } 1190 1191 /* 1192 * We may see jumbolen in unaligned location, so 1193 * we'd need to perform bcopy(). 1194 */ 1195 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1196 jumboplen = (u_int32_t)htonl(jumboplen); 1197 1198 #if 1 1199 /* 1200 * if there are multiple jumbo payload options, 1201 * *plenp will be non-zero and the packet will be 1202 * rejected. 1203 * the behavior may need some debate in ipngwg - 1204 * multiple options does not make sense, however, 1205 * there's no explicit mention in specification. 1206 */ 1207 if (*plenp != 0) { 1208 V_ip6stat.ip6s_badoptions++; 1209 icmp6_error(m, ICMP6_PARAM_PROB, 1210 ICMP6_PARAMPROB_HEADER, 1211 erroff + opt + 2 - opthead); 1212 return (-1); 1213 } 1214 #endif 1215 1216 /* 1217 * jumbo payload length must be larger than 65535. 1218 */ 1219 if (jumboplen <= IPV6_MAXPACKET) { 1220 V_ip6stat.ip6s_badoptions++; 1221 icmp6_error(m, ICMP6_PARAM_PROB, 1222 ICMP6_PARAMPROB_HEADER, 1223 erroff + opt + 2 - opthead); 1224 return (-1); 1225 } 1226 *plenp = jumboplen; 1227 1228 break; 1229 default: /* unknown option */ 1230 if (hbhlen < IP6OPT_MINLEN) { 1231 V_ip6stat.ip6s_toosmall++; 1232 goto bad; 1233 } 1234 optlen = ip6_unknown_opt(opt, m, 1235 erroff + opt - opthead); 1236 if (optlen == -1) 1237 return (-1); 1238 optlen += 2; 1239 break; 1240 } 1241 } 1242 1243 return (0); 1244 1245 bad: 1246 m_freem(m); 1247 return (-1); 1248 } 1249 1250 /* 1251 * Unknown option processing. 1252 * The third argument `off' is the offset from the IPv6 header to the option, 1253 * which is necessary if the IPv6 header the and option header and IPv6 header 1254 * is not contiguous in order to return an ICMPv6 error. 1255 */ 1256 int 1257 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1258 { 1259 struct ip6_hdr *ip6; 1260 1261 switch (IP6OPT_TYPE(*optp)) { 1262 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1263 return ((int)*(optp + 1)); 1264 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1265 m_freem(m); 1266 return (-1); 1267 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1268 V_ip6stat.ip6s_badoptions++; 1269 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1270 return (-1); 1271 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1272 V_ip6stat.ip6s_badoptions++; 1273 ip6 = mtod(m, struct ip6_hdr *); 1274 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1275 (m->m_flags & (M_BCAST|M_MCAST))) 1276 m_freem(m); 1277 else 1278 icmp6_error(m, ICMP6_PARAM_PROB, 1279 ICMP6_PARAMPROB_OPTION, off); 1280 return (-1); 1281 } 1282 1283 m_freem(m); /* XXX: NOTREACHED */ 1284 return (-1); 1285 } 1286 1287 /* 1288 * Create the "control" list for this pcb. 1289 * These functions will not modify mbuf chain at all. 1290 * 1291 * With KAME mbuf chain restriction: 1292 * The routine will be called from upper layer handlers like tcp6_input(). 1293 * Thus the routine assumes that the caller (tcp6_input) have already 1294 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1295 * very first mbuf on the mbuf chain. 1296 * 1297 * ip6_savecontrol_v4 will handle those options that are possible to be 1298 * set on a v4-mapped socket. 1299 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1300 * options and handle the v6-only ones itself. 1301 */ 1302 struct mbuf ** 1303 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1304 int *v4only) 1305 { 1306 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1307 1308 #ifdef SO_TIMESTAMP 1309 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1310 struct timeval tv; 1311 1312 microtime(&tv); 1313 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1314 SCM_TIMESTAMP, SOL_SOCKET); 1315 if (*mp) 1316 mp = &(*mp)->m_next; 1317 } 1318 #endif 1319 1320 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1321 if (v4only != NULL) 1322 *v4only = 1; 1323 return (mp); 1324 } 1325 1326 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1327 /* RFC 2292 sec. 5 */ 1328 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1329 struct in6_pktinfo pi6; 1330 1331 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1332 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1333 pi6.ipi6_ifindex = 1334 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1335 1336 *mp = sbcreatecontrol((caddr_t) &pi6, 1337 sizeof(struct in6_pktinfo), 1338 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1339 if (*mp) 1340 mp = &(*mp)->m_next; 1341 } 1342 1343 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1344 int hlim = ip6->ip6_hlim & 0xff; 1345 1346 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1347 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1348 IPPROTO_IPV6); 1349 if (*mp) 1350 mp = &(*mp)->m_next; 1351 } 1352 1353 if (v4only != NULL) 1354 *v4only = 0; 1355 return (mp); 1356 } 1357 1358 void 1359 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1360 { 1361 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1362 int v4only = 0; 1363 1364 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1365 if (v4only) 1366 return; 1367 1368 if ((in6p->inp_flags & IN6P_TCLASS) != 0) { 1369 u_int32_t flowinfo; 1370 int tclass; 1371 1372 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1373 flowinfo >>= 20; 1374 1375 tclass = flowinfo & 0xff; 1376 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1377 IPV6_TCLASS, IPPROTO_IPV6); 1378 if (*mp) 1379 mp = &(*mp)->m_next; 1380 } 1381 1382 /* 1383 * IPV6_HOPOPTS socket option. Recall that we required super-user 1384 * privilege for the option (see ip6_ctloutput), but it might be too 1385 * strict, since there might be some hop-by-hop options which can be 1386 * returned to normal user. 1387 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1388 */ 1389 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1390 /* 1391 * Check if a hop-by-hop options header is contatined in the 1392 * received packet, and if so, store the options as ancillary 1393 * data. Note that a hop-by-hop options header must be 1394 * just after the IPv6 header, which is assured through the 1395 * IPv6 input processing. 1396 */ 1397 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1398 struct ip6_hbh *hbh; 1399 int hbhlen = 0; 1400 #ifdef PULLDOWN_TEST 1401 struct mbuf *ext; 1402 #endif 1403 1404 #ifndef PULLDOWN_TEST 1405 hbh = (struct ip6_hbh *)(ip6 + 1); 1406 hbhlen = (hbh->ip6h_len + 1) << 3; 1407 #else 1408 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1409 ip6->ip6_nxt); 1410 if (ext == NULL) { 1411 V_ip6stat.ip6s_tooshort++; 1412 return; 1413 } 1414 hbh = mtod(ext, struct ip6_hbh *); 1415 hbhlen = (hbh->ip6h_len + 1) << 3; 1416 if (hbhlen != ext->m_len) { 1417 m_freem(ext); 1418 V_ip6stat.ip6s_tooshort++; 1419 return; 1420 } 1421 #endif 1422 1423 /* 1424 * XXX: We copy the whole header even if a 1425 * jumbo payload option is included, the option which 1426 * is to be removed before returning according to 1427 * RFC2292. 1428 * Note: this constraint is removed in RFC3542 1429 */ 1430 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1431 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1432 IPPROTO_IPV6); 1433 if (*mp) 1434 mp = &(*mp)->m_next; 1435 #ifdef PULLDOWN_TEST 1436 m_freem(ext); 1437 #endif 1438 } 1439 } 1440 1441 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1442 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1443 1444 /* 1445 * Search for destination options headers or routing 1446 * header(s) through the header chain, and stores each 1447 * header as ancillary data. 1448 * Note that the order of the headers remains in 1449 * the chain of ancillary data. 1450 */ 1451 while (1) { /* is explicit loop prevention necessary? */ 1452 struct ip6_ext *ip6e = NULL; 1453 int elen; 1454 #ifdef PULLDOWN_TEST 1455 struct mbuf *ext = NULL; 1456 #endif 1457 1458 /* 1459 * if it is not an extension header, don't try to 1460 * pull it from the chain. 1461 */ 1462 switch (nxt) { 1463 case IPPROTO_DSTOPTS: 1464 case IPPROTO_ROUTING: 1465 case IPPROTO_HOPOPTS: 1466 case IPPROTO_AH: /* is it possible? */ 1467 break; 1468 default: 1469 goto loopend; 1470 } 1471 1472 #ifndef PULLDOWN_TEST 1473 if (off + sizeof(*ip6e) > m->m_len) 1474 goto loopend; 1475 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1476 if (nxt == IPPROTO_AH) 1477 elen = (ip6e->ip6e_len + 2) << 2; 1478 else 1479 elen = (ip6e->ip6e_len + 1) << 3; 1480 if (off + elen > m->m_len) 1481 goto loopend; 1482 #else 1483 ext = ip6_pullexthdr(m, off, nxt); 1484 if (ext == NULL) { 1485 V_ip6stat.ip6s_tooshort++; 1486 return; 1487 } 1488 ip6e = mtod(ext, struct ip6_ext *); 1489 if (nxt == IPPROTO_AH) 1490 elen = (ip6e->ip6e_len + 2) << 2; 1491 else 1492 elen = (ip6e->ip6e_len + 1) << 3; 1493 if (elen != ext->m_len) { 1494 m_freem(ext); 1495 V_ip6stat.ip6s_tooshort++; 1496 return; 1497 } 1498 #endif 1499 1500 switch (nxt) { 1501 case IPPROTO_DSTOPTS: 1502 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1503 break; 1504 1505 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1506 IS2292(in6p, 1507 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1508 IPPROTO_IPV6); 1509 if (*mp) 1510 mp = &(*mp)->m_next; 1511 break; 1512 case IPPROTO_ROUTING: 1513 if (!(in6p->inp_flags & IN6P_RTHDR)) 1514 break; 1515 1516 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1517 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1518 IPPROTO_IPV6); 1519 if (*mp) 1520 mp = &(*mp)->m_next; 1521 break; 1522 case IPPROTO_HOPOPTS: 1523 case IPPROTO_AH: /* is it possible? */ 1524 break; 1525 1526 default: 1527 /* 1528 * other cases have been filtered in the above. 1529 * none will visit this case. here we supply 1530 * the code just in case (nxt overwritten or 1531 * other cases). 1532 */ 1533 #ifdef PULLDOWN_TEST 1534 m_freem(ext); 1535 #endif 1536 goto loopend; 1537 1538 } 1539 1540 /* proceed with the next header. */ 1541 off += elen; 1542 nxt = ip6e->ip6e_nxt; 1543 ip6e = NULL; 1544 #ifdef PULLDOWN_TEST 1545 m_freem(ext); 1546 ext = NULL; 1547 #endif 1548 } 1549 loopend: 1550 ; 1551 } 1552 } 1553 #undef IS2292 1554 1555 void 1556 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1557 { 1558 struct socket *so; 1559 struct mbuf *m_mtu; 1560 struct ip6_mtuinfo mtuctl; 1561 1562 so = in6p->inp_socket; 1563 1564 if (mtu == NULL) 1565 return; 1566 1567 #ifdef DIAGNOSTIC 1568 if (so == NULL) /* I believe this is impossible */ 1569 panic("ip6_notify_pmtu: socket is NULL"); 1570 #endif 1571 1572 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1573 mtuctl.ip6m_mtu = *mtu; 1574 mtuctl.ip6m_addr = *dst; 1575 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1576 return; 1577 1578 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1579 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1580 return; 1581 1582 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1583 == 0) { 1584 m_freem(m_mtu); 1585 /* XXX: should count statistics */ 1586 } else 1587 sorwakeup(so); 1588 1589 return; 1590 } 1591 1592 #ifdef PULLDOWN_TEST 1593 /* 1594 * pull single extension header from mbuf chain. returns single mbuf that 1595 * contains the result, or NULL on error. 1596 */ 1597 static struct mbuf * 1598 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1599 { 1600 struct ip6_ext ip6e; 1601 size_t elen; 1602 struct mbuf *n; 1603 1604 #ifdef DIAGNOSTIC 1605 switch (nxt) { 1606 case IPPROTO_DSTOPTS: 1607 case IPPROTO_ROUTING: 1608 case IPPROTO_HOPOPTS: 1609 case IPPROTO_AH: /* is it possible? */ 1610 break; 1611 default: 1612 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1613 } 1614 #endif 1615 1616 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1617 if (nxt == IPPROTO_AH) 1618 elen = (ip6e.ip6e_len + 2) << 2; 1619 else 1620 elen = (ip6e.ip6e_len + 1) << 3; 1621 1622 MGET(n, M_DONTWAIT, MT_DATA); 1623 if (n && elen >= MLEN) { 1624 MCLGET(n, M_DONTWAIT); 1625 if ((n->m_flags & M_EXT) == 0) { 1626 m_free(n); 1627 n = NULL; 1628 } 1629 } 1630 if (!n) 1631 return NULL; 1632 1633 n->m_len = 0; 1634 if (elen >= M_TRAILINGSPACE(n)) { 1635 m_free(n); 1636 return NULL; 1637 } 1638 1639 m_copydata(m, off, elen, mtod(n, caddr_t)); 1640 n->m_len = elen; 1641 return n; 1642 } 1643 #endif 1644 1645 /* 1646 * Get pointer to the previous header followed by the header 1647 * currently processed. 1648 * XXX: This function supposes that 1649 * M includes all headers, 1650 * the next header field and the header length field of each header 1651 * are valid, and 1652 * the sum of each header length equals to OFF. 1653 * Because of these assumptions, this function must be called very 1654 * carefully. Moreover, it will not be used in the near future when 1655 * we develop `neater' mechanism to process extension headers. 1656 */ 1657 char * 1658 ip6_get_prevhdr(struct mbuf *m, int off) 1659 { 1660 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1661 1662 if (off == sizeof(struct ip6_hdr)) 1663 return (&ip6->ip6_nxt); 1664 else { 1665 int len, nxt; 1666 struct ip6_ext *ip6e = NULL; 1667 1668 nxt = ip6->ip6_nxt; 1669 len = sizeof(struct ip6_hdr); 1670 while (len < off) { 1671 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1672 1673 switch (nxt) { 1674 case IPPROTO_FRAGMENT: 1675 len += sizeof(struct ip6_frag); 1676 break; 1677 case IPPROTO_AH: 1678 len += (ip6e->ip6e_len + 2) << 2; 1679 break; 1680 default: 1681 len += (ip6e->ip6e_len + 1) << 3; 1682 break; 1683 } 1684 nxt = ip6e->ip6e_nxt; 1685 } 1686 if (ip6e) 1687 return (&ip6e->ip6e_nxt); 1688 else 1689 return NULL; 1690 } 1691 } 1692 1693 /* 1694 * get next header offset. m will be retained. 1695 */ 1696 int 1697 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1698 { 1699 struct ip6_hdr ip6; 1700 struct ip6_ext ip6e; 1701 struct ip6_frag fh; 1702 1703 /* just in case */ 1704 if (m == NULL) 1705 panic("ip6_nexthdr: m == NULL"); 1706 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1707 return -1; 1708 1709 switch (proto) { 1710 case IPPROTO_IPV6: 1711 if (m->m_pkthdr.len < off + sizeof(ip6)) 1712 return -1; 1713 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1714 if (nxtp) 1715 *nxtp = ip6.ip6_nxt; 1716 off += sizeof(ip6); 1717 return off; 1718 1719 case IPPROTO_FRAGMENT: 1720 /* 1721 * terminate parsing if it is not the first fragment, 1722 * it does not make sense to parse through it. 1723 */ 1724 if (m->m_pkthdr.len < off + sizeof(fh)) 1725 return -1; 1726 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1727 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1728 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1729 return -1; 1730 if (nxtp) 1731 *nxtp = fh.ip6f_nxt; 1732 off += sizeof(struct ip6_frag); 1733 return off; 1734 1735 case IPPROTO_AH: 1736 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1737 return -1; 1738 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1739 if (nxtp) 1740 *nxtp = ip6e.ip6e_nxt; 1741 off += (ip6e.ip6e_len + 2) << 2; 1742 return off; 1743 1744 case IPPROTO_HOPOPTS: 1745 case IPPROTO_ROUTING: 1746 case IPPROTO_DSTOPTS: 1747 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1748 return -1; 1749 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1750 if (nxtp) 1751 *nxtp = ip6e.ip6e_nxt; 1752 off += (ip6e.ip6e_len + 1) << 3; 1753 return off; 1754 1755 case IPPROTO_NONE: 1756 case IPPROTO_ESP: 1757 case IPPROTO_IPCOMP: 1758 /* give up */ 1759 return -1; 1760 1761 default: 1762 return -1; 1763 } 1764 1765 return -1; 1766 } 1767 1768 /* 1769 * get offset for the last header in the chain. m will be kept untainted. 1770 */ 1771 int 1772 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1773 { 1774 int newoff; 1775 int nxt; 1776 1777 if (!nxtp) { 1778 nxt = -1; 1779 nxtp = &nxt; 1780 } 1781 while (1) { 1782 newoff = ip6_nexthdr(m, off, proto, nxtp); 1783 if (newoff < 0) 1784 return off; 1785 else if (newoff < off) 1786 return -1; /* invalid */ 1787 else if (newoff == off) 1788 return newoff; 1789 1790 off = newoff; 1791 proto = *nxtp; 1792 } 1793 } 1794 1795 static struct ip6aux * 1796 ip6_addaux(struct mbuf *m) 1797 { 1798 struct m_tag *mtag; 1799 1800 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1801 if (!mtag) { 1802 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1803 M_NOWAIT); 1804 if (mtag) { 1805 m_tag_prepend(m, mtag); 1806 bzero(mtag + 1, sizeof(struct ip6aux)); 1807 } 1808 } 1809 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1810 } 1811 1812 static struct ip6aux * 1813 ip6_findaux(struct mbuf *m) 1814 { 1815 struct m_tag *mtag; 1816 1817 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1818 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1819 } 1820 1821 static void 1822 ip6_delaux(struct mbuf *m) 1823 { 1824 struct m_tag *mtag; 1825 1826 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1827 if (mtag) 1828 m_tag_delete(m, mtag); 1829 } 1830 1831 /* 1832 * System control for IP6 1833 */ 1834 1835 u_char inet6ctlerrmap[PRC_NCMDS] = { 1836 0, 0, 0, 0, 1837 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1838 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1839 EMSGSIZE, EHOSTUNREACH, 0, 0, 1840 0, 0, 0, 0, 1841 ENOPROTOOPT 1842 }; 1843