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/sdt.h> 80 #include <sys/socket.h> 81 #include <sys/socketvar.h> 82 #include <sys/errno.h> 83 #include <sys/time.h> 84 #include <sys/kernel.h> 85 #include <sys/syslog.h> 86 87 #include <net/if.h> 88 #include <net/if_var.h> 89 #include <net/if_types.h> 90 #include <net/if_dl.h> 91 #include <net/route.h> 92 #include <net/netisr.h> 93 #include <net/pfil.h> 94 #include <net/vnet.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_kdtrace.h> 98 #include <netinet/ip_var.h> 99 #include <netinet/in_systm.h> 100 #include <net/if_llatbl.h> 101 #ifdef INET 102 #include <netinet/ip.h> 103 #include <netinet/ip_icmp.h> 104 #endif /* INET */ 105 #include <netinet/ip6.h> 106 #include <netinet6/in6_var.h> 107 #include <netinet6/ip6_var.h> 108 #include <netinet/in_pcb.h> 109 #include <netinet/icmp6.h> 110 #include <netinet6/scope6_var.h> 111 #include <netinet6/in6_ifattach.h> 112 #include <netinet6/nd6.h> 113 114 #ifdef IPSEC 115 #include <netipsec/ipsec.h> 116 #include <netinet6/ip6_ipsec.h> 117 #include <netipsec/ipsec6.h> 118 #endif /* IPSEC */ 119 120 #include <netinet6/ip6protosw.h> 121 122 extern struct domain inet6domain; 123 124 u_char ip6_protox[IPPROTO_MAX]; 125 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); 126 VNET_DEFINE(struct in6_ifaddrlisthead *, in6_ifaddrhashtbl); 127 VNET_DEFINE(u_long, in6_ifaddrhmask); 128 129 static struct netisr_handler ip6_nh = { 130 .nh_name = "ip6", 131 .nh_handler = ip6_input, 132 .nh_proto = NETISR_IPV6, 133 .nh_policy = NETISR_POLICY_FLOW, 134 }; 135 136 VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch); 137 #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch) 138 139 VNET_DEFINE(struct pfil_head, inet6_pfil_hook); 140 141 VNET_PCPUSTAT_DEFINE(struct ip6stat, ip6stat); 142 VNET_PCPUSTAT_SYSINIT(ip6stat); 143 #ifdef VIMAGE 144 VNET_PCPUSTAT_SYSUNINIT(ip6stat); 145 #endif /* VIMAGE */ 146 147 struct rwlock in6_ifaddr_lock; 148 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); 149 150 static void ip6_init2(void *); 151 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 152 #ifdef PULLDOWN_TEST 153 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 154 #endif 155 156 /* 157 * IP6 initialization: fill in IP6 protocol switch table. 158 * All protocols not implemented in kernel go to raw IP6 protocol handler. 159 */ 160 void 161 ip6_init(void) 162 { 163 struct protosw *pr; 164 int i; 165 166 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 167 &V_ip6_auto_linklocal); 168 TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv); 169 TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr); 170 171 TAILQ_INIT(&V_in6_ifaddrhead); 172 V_in6_ifaddrhashtbl = hashinit(IN6ADDR_NHASH, M_IFADDR, 173 &V_in6_ifaddrhmask); 174 175 /* Initialize packet filter hooks. */ 176 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 177 V_inet6_pfil_hook.ph_af = AF_INET6; 178 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0) 179 printf("%s: WARNING: unable to register pfil hook, " 180 "error %d\n", __func__, i); 181 182 scope6_init(); 183 addrsel_policy_init(); 184 nd6_init(); 185 frag6_init(); 186 187 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 188 189 /* Skip global initialization stuff for non-default instances. */ 190 if (!IS_DEFAULT_VNET(curvnet)) 191 return; 192 193 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 194 if (pr == NULL) 195 panic("ip6_init"); 196 197 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 198 for (i = 0; i < IPPROTO_MAX; i++) 199 ip6_protox[i] = pr - inet6sw; 200 /* 201 * Cycle through IP protocols and put them into the appropriate place 202 * in ip6_protox[]. 203 */ 204 for (pr = inet6domain.dom_protosw; 205 pr < inet6domain.dom_protoswNPROTOSW; pr++) 206 if (pr->pr_domain->dom_family == PF_INET6 && 207 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 208 /* Be careful to only index valid IP protocols. */ 209 if (pr->pr_protocol < IPPROTO_MAX) 210 ip6_protox[pr->pr_protocol] = pr - inet6sw; 211 } 212 213 netisr_register(&ip6_nh); 214 } 215 216 /* 217 * The protocol to be inserted into ip6_protox[] must be already registered 218 * in inet6sw[], either statically or through pf_proto_register(). 219 */ 220 int 221 ip6proto_register(short ip6proto) 222 { 223 struct protosw *pr; 224 225 /* Sanity checks. */ 226 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX) 227 return (EPROTONOSUPPORT); 228 229 /* 230 * The protocol slot must not be occupied by another protocol 231 * already. An index pointing to IPPROTO_RAW is unused. 232 */ 233 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 234 if (pr == NULL) 235 return (EPFNOSUPPORT); 236 if (ip6_protox[ip6proto] != pr - inet6sw) /* IPPROTO_RAW */ 237 return (EEXIST); 238 239 /* 240 * Find the protocol position in inet6sw[] and set the index. 241 */ 242 for (pr = inet6domain.dom_protosw; 243 pr < inet6domain.dom_protoswNPROTOSW; pr++) { 244 if (pr->pr_domain->dom_family == PF_INET6 && 245 pr->pr_protocol && pr->pr_protocol == ip6proto) { 246 ip6_protox[pr->pr_protocol] = pr - inet6sw; 247 return (0); 248 } 249 } 250 return (EPROTONOSUPPORT); 251 } 252 253 int 254 ip6proto_unregister(short ip6proto) 255 { 256 struct protosw *pr; 257 258 /* Sanity checks. */ 259 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX) 260 return (EPROTONOSUPPORT); 261 262 /* Check if the protocol was indeed registered. */ 263 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 264 if (pr == NULL) 265 return (EPFNOSUPPORT); 266 if (ip6_protox[ip6proto] == pr - inet6sw) /* IPPROTO_RAW */ 267 return (ENOENT); 268 269 /* Reset the protocol slot to IPPROTO_RAW. */ 270 ip6_protox[ip6proto] = pr - inet6sw; 271 return (0); 272 } 273 274 #ifdef VIMAGE 275 void 276 ip6_destroy() 277 { 278 int i; 279 280 if ((i = pfil_head_unregister(&V_inet6_pfil_hook)) != 0) 281 printf("%s: WARNING: unable to unregister pfil hook, " 282 "error %d\n", __func__, i); 283 hashdestroy(V_in6_ifaddrhashtbl, M_IFADDR, V_in6_ifaddrhmask); 284 nd6_destroy(); 285 callout_drain(&V_in6_tmpaddrtimer_ch); 286 } 287 #endif 288 289 static int 290 ip6_init2_vnet(const void *unused __unused) 291 { 292 293 /* nd6_timer_init */ 294 callout_init(&V_nd6_timer_ch, 0); 295 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); 296 297 /* timer for regeneranation of temporary addresses randomize ID */ 298 callout_init(&V_in6_tmpaddrtimer_ch, 0); 299 callout_reset(&V_in6_tmpaddrtimer_ch, 300 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - 301 V_ip6_temp_regen_advance) * hz, 302 in6_tmpaddrtimer, curvnet); 303 304 return (0); 305 } 306 307 static void 308 ip6_init2(void *dummy) 309 { 310 311 ip6_init2_vnet(NULL); 312 } 313 314 /* cheat */ 315 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 316 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 317 318 static int 319 ip6_input_hbh(struct mbuf *m, uint32_t *plen, uint32_t *rtalert, int *off, 320 int *nxt, int *ours) 321 { 322 struct ip6_hdr *ip6; 323 struct ip6_hbh *hbh; 324 325 if (ip6_hopopts_input(plen, rtalert, &m, off)) { 326 #if 0 /*touches NULL pointer*/ 327 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 328 #endif 329 goto out; /* m have already been freed */ 330 } 331 332 /* adjust pointer */ 333 ip6 = mtod(m, struct ip6_hdr *); 334 335 /* 336 * if the payload length field is 0 and the next header field 337 * indicates Hop-by-Hop Options header, then a Jumbo Payload 338 * option MUST be included. 339 */ 340 if (ip6->ip6_plen == 0 && *plen == 0) { 341 /* 342 * Note that if a valid jumbo payload option is 343 * contained, ip6_hopopts_input() must set a valid 344 * (non-zero) payload length to the variable plen. 345 */ 346 IP6STAT_INC(ip6s_badoptions); 347 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 348 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 349 icmp6_error(m, ICMP6_PARAM_PROB, 350 ICMP6_PARAMPROB_HEADER, 351 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 352 goto out; 353 } 354 #ifndef PULLDOWN_TEST 355 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 356 hbh = (struct ip6_hbh *)(ip6 + 1); 357 #else 358 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 359 sizeof(struct ip6_hbh)); 360 if (hbh == NULL) { 361 IP6STAT_INC(ip6s_tooshort); 362 goto out; 363 } 364 #endif 365 *nxt = hbh->ip6h_nxt; 366 367 /* 368 * If we are acting as a router and the packet contains a 369 * router alert option, see if we know the option value. 370 * Currently, we only support the option value for MLD, in which 371 * case we should pass the packet to the multicast routing 372 * daemon. 373 */ 374 if (*rtalert != ~0) { 375 switch (*rtalert) { 376 case IP6OPT_RTALERT_MLD: 377 if (V_ip6_forwarding) 378 *ours = 1; 379 break; 380 default: 381 /* 382 * RFC2711 requires unrecognized values must be 383 * silently ignored. 384 */ 385 break; 386 } 387 } 388 389 return (0); 390 391 out: 392 return (1); 393 } 394 395 void 396 ip6_input(struct mbuf *m) 397 { 398 struct in6_addr odst; 399 struct ip6_hdr *ip6; 400 struct in6_ifaddr *ia; 401 u_int32_t plen; 402 u_int32_t rtalert = ~0; 403 int off = sizeof(struct ip6_hdr), nest; 404 int nxt, ours = 0; 405 int srcrt = 0; 406 407 #ifdef IPSEC 408 /* 409 * should the inner packet be considered authentic? 410 * see comment in ah4_input(). 411 * NB: m cannot be NULL when passed to the input routine 412 */ 413 414 m->m_flags &= ~M_AUTHIPHDR; 415 m->m_flags &= ~M_AUTHIPDGM; 416 417 #endif /* IPSEC */ 418 419 if (m->m_flags & M_FASTFWD_OURS) { 420 /* 421 * Firewall changed destination to local. 422 */ 423 m->m_flags &= ~M_FASTFWD_OURS; 424 ours = 1; 425 ip6 = mtod(m, struct ip6_hdr *); 426 goto hbhcheck; 427 } 428 429 /* 430 * mbuf statistics 431 */ 432 if (m->m_flags & M_EXT) { 433 if (m->m_next) 434 IP6STAT_INC(ip6s_mext2m); 435 else 436 IP6STAT_INC(ip6s_mext1); 437 } else { 438 if (m->m_next) { 439 if (m->m_flags & M_LOOP) { 440 IP6STAT_INC(ip6s_m2m[V_loif->if_index]); 441 } else if (m->m_pkthdr.rcvif->if_index < IP6S_M2MMAX) 442 IP6STAT_INC( 443 ip6s_m2m[m->m_pkthdr.rcvif->if_index]); 444 else 445 IP6STAT_INC(ip6s_m2m[0]); 446 } else 447 IP6STAT_INC(ip6s_m1); 448 } 449 450 /* drop the packet if IPv6 operation is disabled on the IF */ 451 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) 452 goto bad; 453 454 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 455 IP6STAT_INC(ip6s_total); 456 457 #ifndef PULLDOWN_TEST 458 /* 459 * L2 bridge code and some other code can return mbuf chain 460 * that does not conform to KAME requirement. too bad. 461 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 462 */ 463 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 464 struct mbuf *n; 465 466 if (m->m_pkthdr.len > MHLEN) 467 n = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 468 else 469 n = m_gethdr(M_NOWAIT, MT_DATA); 470 if (n == NULL) { 471 m_freem(m); 472 return; /* ENOBUFS */ 473 } 474 475 m_move_pkthdr(n, m); 476 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 477 n->m_len = n->m_pkthdr.len; 478 m_freem(m); 479 m = n; 480 } 481 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 482 #endif 483 484 if (m->m_len < sizeof(struct ip6_hdr)) { 485 struct ifnet *inifp; 486 inifp = m->m_pkthdr.rcvif; 487 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 488 IP6STAT_INC(ip6s_toosmall); 489 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 490 return; 491 } 492 } 493 494 ip6 = mtod(m, struct ip6_hdr *); 495 496 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 497 IP6STAT_INC(ip6s_badvers); 498 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 499 goto bad; 500 } 501 502 IP6STAT_INC(ip6s_nxthist[ip6->ip6_nxt]); 503 504 IP_PROBE(receive, NULL, NULL, ip6, m->m_pkthdr.rcvif, NULL, ip6); 505 506 /* 507 * Check against address spoofing/corruption. 508 */ 509 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 510 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 511 /* 512 * XXX: "badscope" is not very suitable for a multicast source. 513 */ 514 IP6STAT_INC(ip6s_badscope); 515 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 516 goto bad; 517 } 518 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 519 !(m->m_flags & M_LOOP)) { 520 /* 521 * In this case, the packet should come from the loopback 522 * interface. However, we cannot just check the if_flags, 523 * because ip6_mloopback() passes the "actual" interface 524 * as the outgoing/incoming interface. 525 */ 526 IP6STAT_INC(ip6s_badscope); 527 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 528 goto bad; 529 } 530 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) && 531 IPV6_ADDR_MC_SCOPE(&ip6->ip6_dst) == 0) { 532 /* 533 * RFC4291 2.7: 534 * Nodes must not originate a packet to a multicast address 535 * whose scop field contains the reserved value 0; if such 536 * a packet is received, it must be silently dropped. 537 */ 538 IP6STAT_INC(ip6s_badscope); 539 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 540 goto bad; 541 } 542 #ifdef ALTQ 543 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 544 /* packet is dropped by traffic conditioner */ 545 return; 546 } 547 #endif 548 /* 549 * The following check is not documented in specs. A malicious 550 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 551 * and bypass security checks (act as if it was from 127.0.0.1 by using 552 * IPv6 src ::ffff:127.0.0.1). Be cautious. 553 * 554 * This check chokes if we are in an SIIT cloud. As none of BSDs 555 * support IPv4-less kernel compilation, we cannot support SIIT 556 * environment at all. So, it makes more sense for us to reject any 557 * malicious packets for non-SIIT environment, than try to do a 558 * partial support for SIIT environment. 559 */ 560 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 561 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 562 IP6STAT_INC(ip6s_badscope); 563 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 564 goto bad; 565 } 566 #if 0 567 /* 568 * Reject packets with IPv4 compatible addresses (auto tunnel). 569 * 570 * The code forbids auto tunnel relay case in RFC1933 (the check is 571 * stronger than RFC1933). We may want to re-enable it if mech-xx 572 * is revised to forbid relaying case. 573 */ 574 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 575 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 576 IP6STAT_INC(ip6s_badscope); 577 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 578 goto bad; 579 } 580 #endif 581 #ifdef IPSEC 582 /* 583 * Bypass packet filtering for packets previously handled by IPsec. 584 */ 585 if (ip6_ipsec_filtertunnel(m)) 586 goto passin; 587 #endif /* IPSEC */ 588 589 /* 590 * Run through list of hooks for input packets. 591 * 592 * NB: Beware of the destination address changing 593 * (e.g. by NAT rewriting). When this happens, 594 * tell ip6_forward to do the right thing. 595 */ 596 odst = ip6->ip6_dst; 597 598 /* Jump over all PFIL processing if hooks are not active. */ 599 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 600 goto passin; 601 602 if (pfil_run_hooks(&V_inet6_pfil_hook, &m, 603 m->m_pkthdr.rcvif, PFIL_IN, NULL)) 604 return; 605 if (m == NULL) /* consumed by filter */ 606 return; 607 ip6 = mtod(m, struct ip6_hdr *); 608 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 609 610 if (m->m_flags & M_FASTFWD_OURS) { 611 m->m_flags &= ~M_FASTFWD_OURS; 612 ours = 1; 613 goto hbhcheck; 614 } 615 if ((m->m_flags & M_IP6_NEXTHOP) && 616 m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) { 617 /* 618 * Directly ship the packet on. This allows forwarding 619 * packets originally destined to us to some other directly 620 * connected host. 621 */ 622 ip6_forward(m, 1); 623 return; 624 } 625 626 passin: 627 /* 628 * Disambiguate address scope zones (if there is ambiguity). 629 * We first make sure that the original source or destination address 630 * is not in our internal form for scoped addresses. Such addresses 631 * are not necessarily invalid spec-wise, but we cannot accept them due 632 * to the usage conflict. 633 * in6_setscope() then also checks and rejects the cases where src or 634 * dst are the loopback address and the receiving interface 635 * is not loopback. 636 */ 637 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 638 IP6STAT_INC(ip6s_badscope); /* XXX */ 639 goto bad; 640 } 641 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 642 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 643 IP6STAT_INC(ip6s_badscope); 644 goto bad; 645 } 646 /* 647 * Multicast check. Assume packet is for us to avoid 648 * prematurely taking locks. 649 */ 650 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 651 ours = 1; 652 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 653 goto hbhcheck; 654 } 655 /* 656 * Unicast check 657 * XXX: For now we keep link-local IPv6 addresses with embedded 658 * scope zone id, therefore we use zero zoneid here. 659 */ 660 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 661 if (ia != NULL) { 662 if (ia->ia6_flags & IN6_IFF_NOTREADY) { 663 char ip6bufs[INET6_ADDRSTRLEN]; 664 char ip6bufd[INET6_ADDRSTRLEN]; 665 /* address is not ready, so discard the packet. */ 666 nd6log((LOG_INFO, 667 "ip6_input: packet to an unready address %s->%s\n", 668 ip6_sprintf(ip6bufs, &ip6->ip6_src), 669 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 670 ifa_free(&ia->ia_ifa); 671 goto bad; 672 } 673 /* Count the packet in the ip address stats */ 674 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); 675 counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len); 676 ifa_free(&ia->ia_ifa); 677 ours = 1; 678 goto hbhcheck; 679 } 680 681 /* 682 * Now there is no reason to process the packet if it's not our own 683 * and we're not a router. 684 */ 685 if (!V_ip6_forwarding) { 686 IP6STAT_INC(ip6s_cantforward); 687 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 688 goto bad; 689 } 690 691 hbhcheck: 692 /* 693 * Process Hop-by-Hop options header if it's contained. 694 * m may be modified in ip6_hopopts_input(). 695 * If a JumboPayload option is included, plen will also be modified. 696 */ 697 plen = (u_int32_t)ntohs(ip6->ip6_plen); 698 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 699 if (ip6_input_hbh(m, &plen, &rtalert, &off, &nxt, &ours) != 0) 700 return; 701 } else 702 nxt = ip6->ip6_nxt; 703 704 /* 705 * Check that the amount of data in the buffers 706 * is as at least much as the IPv6 header would have us expect. 707 * Trim mbufs if longer than we expect. 708 * Drop packet if shorter than we expect. 709 */ 710 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 711 IP6STAT_INC(ip6s_tooshort); 712 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 713 goto bad; 714 } 715 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 716 if (m->m_len == m->m_pkthdr.len) { 717 m->m_len = sizeof(struct ip6_hdr) + plen; 718 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 719 } else 720 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 721 } 722 723 /* 724 * Forward if desirable. 725 */ 726 if (V_ip6_mrouter && 727 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 728 /* 729 * If we are acting as a multicast router, all 730 * incoming multicast packets are passed to the 731 * kernel-level multicast forwarding function. 732 * The packet is returned (relatively) intact; if 733 * ip6_mforward() returns a non-zero value, the packet 734 * must be discarded, else it may be accepted below. 735 * 736 * XXX TODO: Check hlim and multicast scope here to avoid 737 * unnecessarily calling into ip6_mforward(). 738 */ 739 if (ip6_mforward && 740 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 741 IP6STAT_INC(ip6s_cantforward); 742 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 743 goto bad; 744 } 745 } else if (!ours) { 746 ip6_forward(m, srcrt); 747 return; 748 } 749 750 ip6 = mtod(m, struct ip6_hdr *); 751 752 /* 753 * Malicious party may be able to use IPv4 mapped addr to confuse 754 * tcp/udp stack and bypass security checks (act as if it was from 755 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 756 * 757 * For SIIT end node behavior, you may want to disable the check. 758 * However, you will become vulnerable to attacks using IPv4 mapped 759 * source. 760 */ 761 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 762 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 763 IP6STAT_INC(ip6s_badscope); 764 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 765 goto bad; 766 } 767 768 /* 769 * Tell launch routine the next header 770 */ 771 IP6STAT_INC(ip6s_delivered); 772 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_deliver); 773 nest = 0; 774 775 while (nxt != IPPROTO_DONE) { 776 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 777 IP6STAT_INC(ip6s_toomanyhdr); 778 goto bad; 779 } 780 781 /* 782 * protection against faulty packet - there should be 783 * more sanity checks in header chain processing. 784 */ 785 if (m->m_pkthdr.len < off) { 786 IP6STAT_INC(ip6s_tooshort); 787 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 788 goto bad; 789 } 790 791 #ifdef IPSEC 792 /* 793 * enforce IPsec policy checking if we are seeing last header. 794 * note that we do not visit this with protocols with pcb layer 795 * code - like udp/tcp/raw ip. 796 */ 797 if (ip6_ipsec_input(m, nxt)) 798 goto bad; 799 #endif /* IPSEC */ 800 801 /* 802 * Use mbuf flags to propagate Router Alert option to 803 * ICMPv6 layer, as hop-by-hop options have been stripped. 804 */ 805 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) 806 m->m_flags |= M_RTALERT_MLD; 807 808 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 809 } 810 return; 811 bad: 812 m_freem(m); 813 } 814 815 /* 816 * Hop-by-Hop options header processing. If a valid jumbo payload option is 817 * included, the real payload length will be stored in plenp. 818 * 819 * rtalertp - XXX: should be stored more smart way 820 */ 821 static int 822 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 823 struct mbuf **mp, int *offp) 824 { 825 struct mbuf *m = *mp; 826 int off = *offp, hbhlen; 827 struct ip6_hbh *hbh; 828 829 /* validation of the length of the header */ 830 #ifndef PULLDOWN_TEST 831 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 832 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 833 hbhlen = (hbh->ip6h_len + 1) << 3; 834 835 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 836 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 837 #else 838 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 839 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 840 if (hbh == NULL) { 841 IP6STAT_INC(ip6s_tooshort); 842 return -1; 843 } 844 hbhlen = (hbh->ip6h_len + 1) << 3; 845 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 846 hbhlen); 847 if (hbh == NULL) { 848 IP6STAT_INC(ip6s_tooshort); 849 return -1; 850 } 851 #endif 852 off += hbhlen; 853 hbhlen -= sizeof(struct ip6_hbh); 854 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 855 hbhlen, rtalertp, plenp) < 0) 856 return (-1); 857 858 *offp = off; 859 *mp = m; 860 return (0); 861 } 862 863 /* 864 * Search header for all Hop-by-hop options and process each option. 865 * This function is separate from ip6_hopopts_input() in order to 866 * handle a case where the sending node itself process its hop-by-hop 867 * options header. In such a case, the function is called from ip6_output(). 868 * 869 * The function assumes that hbh header is located right after the IPv6 header 870 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 871 * opthead + hbhlen is located in contiguous memory region. 872 */ 873 int 874 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 875 u_int32_t *rtalertp, u_int32_t *plenp) 876 { 877 struct ip6_hdr *ip6; 878 int optlen = 0; 879 u_int8_t *opt = opthead; 880 u_int16_t rtalert_val; 881 u_int32_t jumboplen; 882 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 883 884 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 885 switch (*opt) { 886 case IP6OPT_PAD1: 887 optlen = 1; 888 break; 889 case IP6OPT_PADN: 890 if (hbhlen < IP6OPT_MINLEN) { 891 IP6STAT_INC(ip6s_toosmall); 892 goto bad; 893 } 894 optlen = *(opt + 1) + 2; 895 break; 896 case IP6OPT_ROUTER_ALERT: 897 /* XXX may need check for alignment */ 898 if (hbhlen < IP6OPT_RTALERT_LEN) { 899 IP6STAT_INC(ip6s_toosmall); 900 goto bad; 901 } 902 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 903 /* XXX stat */ 904 icmp6_error(m, ICMP6_PARAM_PROB, 905 ICMP6_PARAMPROB_HEADER, 906 erroff + opt + 1 - opthead); 907 return (-1); 908 } 909 optlen = IP6OPT_RTALERT_LEN; 910 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 911 *rtalertp = ntohs(rtalert_val); 912 break; 913 case IP6OPT_JUMBO: 914 /* XXX may need check for alignment */ 915 if (hbhlen < IP6OPT_JUMBO_LEN) { 916 IP6STAT_INC(ip6s_toosmall); 917 goto bad; 918 } 919 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 920 /* XXX stat */ 921 icmp6_error(m, ICMP6_PARAM_PROB, 922 ICMP6_PARAMPROB_HEADER, 923 erroff + opt + 1 - opthead); 924 return (-1); 925 } 926 optlen = IP6OPT_JUMBO_LEN; 927 928 /* 929 * IPv6 packets that have non 0 payload length 930 * must not contain a jumbo payload option. 931 */ 932 ip6 = mtod(m, struct ip6_hdr *); 933 if (ip6->ip6_plen) { 934 IP6STAT_INC(ip6s_badoptions); 935 icmp6_error(m, ICMP6_PARAM_PROB, 936 ICMP6_PARAMPROB_HEADER, 937 erroff + opt - opthead); 938 return (-1); 939 } 940 941 /* 942 * We may see jumbolen in unaligned location, so 943 * we'd need to perform bcopy(). 944 */ 945 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 946 jumboplen = (u_int32_t)htonl(jumboplen); 947 948 #if 1 949 /* 950 * if there are multiple jumbo payload options, 951 * *plenp will be non-zero and the packet will be 952 * rejected. 953 * the behavior may need some debate in ipngwg - 954 * multiple options does not make sense, however, 955 * there's no explicit mention in specification. 956 */ 957 if (*plenp != 0) { 958 IP6STAT_INC(ip6s_badoptions); 959 icmp6_error(m, ICMP6_PARAM_PROB, 960 ICMP6_PARAMPROB_HEADER, 961 erroff + opt + 2 - opthead); 962 return (-1); 963 } 964 #endif 965 966 /* 967 * jumbo payload length must be larger than 65535. 968 */ 969 if (jumboplen <= IPV6_MAXPACKET) { 970 IP6STAT_INC(ip6s_badoptions); 971 icmp6_error(m, ICMP6_PARAM_PROB, 972 ICMP6_PARAMPROB_HEADER, 973 erroff + opt + 2 - opthead); 974 return (-1); 975 } 976 *plenp = jumboplen; 977 978 break; 979 default: /* unknown option */ 980 if (hbhlen < IP6OPT_MINLEN) { 981 IP6STAT_INC(ip6s_toosmall); 982 goto bad; 983 } 984 optlen = ip6_unknown_opt(opt, m, 985 erroff + opt - opthead); 986 if (optlen == -1) 987 return (-1); 988 optlen += 2; 989 break; 990 } 991 } 992 993 return (0); 994 995 bad: 996 m_freem(m); 997 return (-1); 998 } 999 1000 /* 1001 * Unknown option processing. 1002 * The third argument `off' is the offset from the IPv6 header to the option, 1003 * which is necessary if the IPv6 header the and option header and IPv6 header 1004 * is not contiguous in order to return an ICMPv6 error. 1005 */ 1006 int 1007 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1008 { 1009 struct ip6_hdr *ip6; 1010 1011 switch (IP6OPT_TYPE(*optp)) { 1012 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1013 return ((int)*(optp + 1)); 1014 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1015 m_freem(m); 1016 return (-1); 1017 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1018 IP6STAT_INC(ip6s_badoptions); 1019 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1020 return (-1); 1021 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1022 IP6STAT_INC(ip6s_badoptions); 1023 ip6 = mtod(m, struct ip6_hdr *); 1024 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1025 (m->m_flags & (M_BCAST|M_MCAST))) 1026 m_freem(m); 1027 else 1028 icmp6_error(m, ICMP6_PARAM_PROB, 1029 ICMP6_PARAMPROB_OPTION, off); 1030 return (-1); 1031 } 1032 1033 m_freem(m); /* XXX: NOTREACHED */ 1034 return (-1); 1035 } 1036 1037 /* 1038 * Create the "control" list for this pcb. 1039 * These functions will not modify mbuf chain at all. 1040 * 1041 * With KAME mbuf chain restriction: 1042 * The routine will be called from upper layer handlers like tcp6_input(). 1043 * Thus the routine assumes that the caller (tcp6_input) have already 1044 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1045 * very first mbuf on the mbuf chain. 1046 * 1047 * ip6_savecontrol_v4 will handle those options that are possible to be 1048 * set on a v4-mapped socket. 1049 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1050 * options and handle the v6-only ones itself. 1051 */ 1052 struct mbuf ** 1053 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1054 int *v4only) 1055 { 1056 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1057 1058 #ifdef SO_TIMESTAMP 1059 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1060 struct timeval tv; 1061 1062 microtime(&tv); 1063 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1064 SCM_TIMESTAMP, SOL_SOCKET); 1065 if (*mp) 1066 mp = &(*mp)->m_next; 1067 } 1068 #endif 1069 1070 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1071 /* RFC 2292 sec. 5 */ 1072 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1073 struct in6_pktinfo pi6; 1074 1075 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1076 #ifdef INET 1077 struct ip *ip; 1078 1079 ip = mtod(m, struct ip *); 1080 pi6.ipi6_addr.s6_addr32[0] = 0; 1081 pi6.ipi6_addr.s6_addr32[1] = 0; 1082 pi6.ipi6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP; 1083 pi6.ipi6_addr.s6_addr32[3] = ip->ip_dst.s_addr; 1084 #else 1085 /* We won't hit this code */ 1086 bzero(&pi6.ipi6_addr, sizeof(struct in6_addr)); 1087 #endif 1088 } else { 1089 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1090 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1091 } 1092 pi6.ipi6_ifindex = 1093 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1094 1095 *mp = sbcreatecontrol((caddr_t) &pi6, 1096 sizeof(struct in6_pktinfo), 1097 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1098 if (*mp) 1099 mp = &(*mp)->m_next; 1100 } 1101 1102 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1103 int hlim; 1104 1105 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1106 #ifdef INET 1107 struct ip *ip; 1108 1109 ip = mtod(m, struct ip *); 1110 hlim = ip->ip_ttl; 1111 #else 1112 /* We won't hit this code */ 1113 hlim = 0; 1114 #endif 1115 } else { 1116 hlim = ip6->ip6_hlim & 0xff; 1117 } 1118 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1119 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1120 IPPROTO_IPV6); 1121 if (*mp) 1122 mp = &(*mp)->m_next; 1123 } 1124 1125 if ((inp->inp_flags & IN6P_TCLASS) != 0) { 1126 int tclass; 1127 1128 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1129 #ifdef INET 1130 struct ip *ip; 1131 1132 ip = mtod(m, struct ip *); 1133 tclass = ip->ip_tos; 1134 #else 1135 /* We won't hit this code */ 1136 tclass = 0; 1137 #endif 1138 } else { 1139 u_int32_t flowinfo; 1140 1141 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1142 flowinfo >>= 20; 1143 tclass = flowinfo & 0xff; 1144 } 1145 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(int), 1146 IPV6_TCLASS, IPPROTO_IPV6); 1147 if (*mp) 1148 mp = &(*mp)->m_next; 1149 } 1150 1151 if (v4only != NULL) { 1152 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1153 *v4only = 1; 1154 } else { 1155 *v4only = 0; 1156 } 1157 } 1158 1159 return (mp); 1160 } 1161 1162 void 1163 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1164 { 1165 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1166 int v4only = 0; 1167 1168 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1169 if (v4only) 1170 return; 1171 1172 /* 1173 * IPV6_HOPOPTS socket option. Recall that we required super-user 1174 * privilege for the option (see ip6_ctloutput), but it might be too 1175 * strict, since there might be some hop-by-hop options which can be 1176 * returned to normal user. 1177 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1178 */ 1179 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1180 /* 1181 * Check if a hop-by-hop options header is contatined in the 1182 * received packet, and if so, store the options as ancillary 1183 * data. Note that a hop-by-hop options header must be 1184 * just after the IPv6 header, which is assured through the 1185 * IPv6 input processing. 1186 */ 1187 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1188 struct ip6_hbh *hbh; 1189 int hbhlen = 0; 1190 #ifdef PULLDOWN_TEST 1191 struct mbuf *ext; 1192 #endif 1193 1194 #ifndef PULLDOWN_TEST 1195 hbh = (struct ip6_hbh *)(ip6 + 1); 1196 hbhlen = (hbh->ip6h_len + 1) << 3; 1197 #else 1198 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1199 ip6->ip6_nxt); 1200 if (ext == NULL) { 1201 IP6STAT_INC(ip6s_tooshort); 1202 return; 1203 } 1204 hbh = mtod(ext, struct ip6_hbh *); 1205 hbhlen = (hbh->ip6h_len + 1) << 3; 1206 if (hbhlen != ext->m_len) { 1207 m_freem(ext); 1208 IP6STAT_INC(ip6s_tooshort); 1209 return; 1210 } 1211 #endif 1212 1213 /* 1214 * XXX: We copy the whole header even if a 1215 * jumbo payload option is included, the option which 1216 * is to be removed before returning according to 1217 * RFC2292. 1218 * Note: this constraint is removed in RFC3542 1219 */ 1220 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1221 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1222 IPPROTO_IPV6); 1223 if (*mp) 1224 mp = &(*mp)->m_next; 1225 #ifdef PULLDOWN_TEST 1226 m_freem(ext); 1227 #endif 1228 } 1229 } 1230 1231 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1232 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1233 1234 /* 1235 * Search for destination options headers or routing 1236 * header(s) through the header chain, and stores each 1237 * header as ancillary data. 1238 * Note that the order of the headers remains in 1239 * the chain of ancillary data. 1240 */ 1241 while (1) { /* is explicit loop prevention necessary? */ 1242 struct ip6_ext *ip6e = NULL; 1243 int elen; 1244 #ifdef PULLDOWN_TEST 1245 struct mbuf *ext = NULL; 1246 #endif 1247 1248 /* 1249 * if it is not an extension header, don't try to 1250 * pull it from the chain. 1251 */ 1252 switch (nxt) { 1253 case IPPROTO_DSTOPTS: 1254 case IPPROTO_ROUTING: 1255 case IPPROTO_HOPOPTS: 1256 case IPPROTO_AH: /* is it possible? */ 1257 break; 1258 default: 1259 goto loopend; 1260 } 1261 1262 #ifndef PULLDOWN_TEST 1263 if (off + sizeof(*ip6e) > m->m_len) 1264 goto loopend; 1265 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1266 if (nxt == IPPROTO_AH) 1267 elen = (ip6e->ip6e_len + 2) << 2; 1268 else 1269 elen = (ip6e->ip6e_len + 1) << 3; 1270 if (off + elen > m->m_len) 1271 goto loopend; 1272 #else 1273 ext = ip6_pullexthdr(m, off, nxt); 1274 if (ext == NULL) { 1275 IP6STAT_INC(ip6s_tooshort); 1276 return; 1277 } 1278 ip6e = mtod(ext, struct ip6_ext *); 1279 if (nxt == IPPROTO_AH) 1280 elen = (ip6e->ip6e_len + 2) << 2; 1281 else 1282 elen = (ip6e->ip6e_len + 1) << 3; 1283 if (elen != ext->m_len) { 1284 m_freem(ext); 1285 IP6STAT_INC(ip6s_tooshort); 1286 return; 1287 } 1288 #endif 1289 1290 switch (nxt) { 1291 case IPPROTO_DSTOPTS: 1292 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1293 break; 1294 1295 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1296 IS2292(in6p, 1297 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1298 IPPROTO_IPV6); 1299 if (*mp) 1300 mp = &(*mp)->m_next; 1301 break; 1302 case IPPROTO_ROUTING: 1303 if (!(in6p->inp_flags & IN6P_RTHDR)) 1304 break; 1305 1306 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1307 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1308 IPPROTO_IPV6); 1309 if (*mp) 1310 mp = &(*mp)->m_next; 1311 break; 1312 case IPPROTO_HOPOPTS: 1313 case IPPROTO_AH: /* is it possible? */ 1314 break; 1315 1316 default: 1317 /* 1318 * other cases have been filtered in the above. 1319 * none will visit this case. here we supply 1320 * the code just in case (nxt overwritten or 1321 * other cases). 1322 */ 1323 #ifdef PULLDOWN_TEST 1324 m_freem(ext); 1325 #endif 1326 goto loopend; 1327 1328 } 1329 1330 /* proceed with the next header. */ 1331 off += elen; 1332 nxt = ip6e->ip6e_nxt; 1333 ip6e = NULL; 1334 #ifdef PULLDOWN_TEST 1335 m_freem(ext); 1336 ext = NULL; 1337 #endif 1338 } 1339 loopend: 1340 ; 1341 } 1342 } 1343 #undef IS2292 1344 1345 void 1346 ip6_notify_pmtu(struct inpcb *inp, struct sockaddr_in6 *dst, u_int32_t mtu) 1347 { 1348 struct socket *so; 1349 struct mbuf *m_mtu; 1350 struct ip6_mtuinfo mtuctl; 1351 1352 KASSERT(inp != NULL, ("%s: inp == NULL", __func__)); 1353 /* 1354 * Notify the error by sending IPV6_PATHMTU ancillary data if 1355 * application wanted to know the MTU value. 1356 * NOTE: we notify disconnected sockets, because some udp 1357 * applications keep sending sockets disconnected. 1358 * NOTE: our implementation doesn't notify connected sockets that has 1359 * foreign address that is different than given destination addresses 1360 * (this is permitted by RFC 3542). 1361 */ 1362 if ((inp->inp_flags & IN6P_MTU) == 0 || ( 1363 !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1364 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &dst->sin6_addr))) 1365 return; 1366 1367 mtuctl.ip6m_mtu = mtu; 1368 mtuctl.ip6m_addr = *dst; 1369 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1370 return; 1371 1372 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1373 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1374 return; 1375 1376 so = inp->inp_socket; 1377 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1378 == 0) { 1379 m_freem(m_mtu); 1380 /* XXX: should count statistics */ 1381 } else 1382 sorwakeup(so); 1383 } 1384 1385 #ifdef PULLDOWN_TEST 1386 /* 1387 * pull single extension header from mbuf chain. returns single mbuf that 1388 * contains the result, or NULL on error. 1389 */ 1390 static struct mbuf * 1391 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1392 { 1393 struct ip6_ext ip6e; 1394 size_t elen; 1395 struct mbuf *n; 1396 1397 #ifdef DIAGNOSTIC 1398 switch (nxt) { 1399 case IPPROTO_DSTOPTS: 1400 case IPPROTO_ROUTING: 1401 case IPPROTO_HOPOPTS: 1402 case IPPROTO_AH: /* is it possible? */ 1403 break; 1404 default: 1405 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1406 } 1407 #endif 1408 1409 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1410 if (nxt == IPPROTO_AH) 1411 elen = (ip6e.ip6e_len + 2) << 2; 1412 else 1413 elen = (ip6e.ip6e_len + 1) << 3; 1414 1415 if (elen > MLEN) 1416 n = m_getcl(M_NOWAIT, MT_DATA, 0); 1417 else 1418 n = m_get(M_NOWAIT, MT_DATA); 1419 if (n == NULL) 1420 return NULL; 1421 1422 m_copydata(m, off, elen, mtod(n, caddr_t)); 1423 n->m_len = elen; 1424 return n; 1425 } 1426 #endif 1427 1428 /* 1429 * Get pointer to the previous header followed by the header 1430 * currently processed. 1431 * XXX: This function supposes that 1432 * M includes all headers, 1433 * the next header field and the header length field of each header 1434 * are valid, and 1435 * the sum of each header length equals to OFF. 1436 * Because of these assumptions, this function must be called very 1437 * carefully. Moreover, it will not be used in the near future when 1438 * we develop `neater' mechanism to process extension headers. 1439 */ 1440 char * 1441 ip6_get_prevhdr(struct mbuf *m, int off) 1442 { 1443 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1444 1445 if (off == sizeof(struct ip6_hdr)) 1446 return (&ip6->ip6_nxt); 1447 else { 1448 int len, nxt; 1449 struct ip6_ext *ip6e = NULL; 1450 1451 nxt = ip6->ip6_nxt; 1452 len = sizeof(struct ip6_hdr); 1453 while (len < off) { 1454 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1455 1456 switch (nxt) { 1457 case IPPROTO_FRAGMENT: 1458 len += sizeof(struct ip6_frag); 1459 break; 1460 case IPPROTO_AH: 1461 len += (ip6e->ip6e_len + 2) << 2; 1462 break; 1463 default: 1464 len += (ip6e->ip6e_len + 1) << 3; 1465 break; 1466 } 1467 nxt = ip6e->ip6e_nxt; 1468 } 1469 if (ip6e) 1470 return (&ip6e->ip6e_nxt); 1471 else 1472 return NULL; 1473 } 1474 } 1475 1476 /* 1477 * get next header offset. m will be retained. 1478 */ 1479 int 1480 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1481 { 1482 struct ip6_hdr ip6; 1483 struct ip6_ext ip6e; 1484 struct ip6_frag fh; 1485 1486 /* just in case */ 1487 if (m == NULL) 1488 panic("ip6_nexthdr: m == NULL"); 1489 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1490 return -1; 1491 1492 switch (proto) { 1493 case IPPROTO_IPV6: 1494 if (m->m_pkthdr.len < off + sizeof(ip6)) 1495 return -1; 1496 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1497 if (nxtp) 1498 *nxtp = ip6.ip6_nxt; 1499 off += sizeof(ip6); 1500 return off; 1501 1502 case IPPROTO_FRAGMENT: 1503 /* 1504 * terminate parsing if it is not the first fragment, 1505 * it does not make sense to parse through it. 1506 */ 1507 if (m->m_pkthdr.len < off + sizeof(fh)) 1508 return -1; 1509 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1510 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1511 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1512 return -1; 1513 if (nxtp) 1514 *nxtp = fh.ip6f_nxt; 1515 off += sizeof(struct ip6_frag); 1516 return off; 1517 1518 case IPPROTO_AH: 1519 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1520 return -1; 1521 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1522 if (nxtp) 1523 *nxtp = ip6e.ip6e_nxt; 1524 off += (ip6e.ip6e_len + 2) << 2; 1525 return off; 1526 1527 case IPPROTO_HOPOPTS: 1528 case IPPROTO_ROUTING: 1529 case IPPROTO_DSTOPTS: 1530 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1531 return -1; 1532 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1533 if (nxtp) 1534 *nxtp = ip6e.ip6e_nxt; 1535 off += (ip6e.ip6e_len + 1) << 3; 1536 return off; 1537 1538 case IPPROTO_NONE: 1539 case IPPROTO_ESP: 1540 case IPPROTO_IPCOMP: 1541 /* give up */ 1542 return -1; 1543 1544 default: 1545 return -1; 1546 } 1547 1548 return -1; 1549 } 1550 1551 /* 1552 * get offset for the last header in the chain. m will be kept untainted. 1553 */ 1554 int 1555 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1556 { 1557 int newoff; 1558 int nxt; 1559 1560 if (!nxtp) { 1561 nxt = -1; 1562 nxtp = &nxt; 1563 } 1564 while (1) { 1565 newoff = ip6_nexthdr(m, off, proto, nxtp); 1566 if (newoff < 0) 1567 return off; 1568 else if (newoff < off) 1569 return -1; /* invalid */ 1570 else if (newoff == off) 1571 return newoff; 1572 1573 off = newoff; 1574 proto = *nxtp; 1575 } 1576 } 1577 1578 /* 1579 * System control for IP6 1580 */ 1581 1582 u_char inet6ctlerrmap[PRC_NCMDS] = { 1583 0, 0, 0, 0, 1584 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1585 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1586 EMSGSIZE, EHOSTUNREACH, 0, 0, 1587 0, 0, 0, 0, 1588 ENOPROTOOPT 1589 }; 1590