1 /* $FreeBSD$ */ 2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_ip6fw.h" 65 #include "opt_inet.h" 66 #include "opt_inet6.h" 67 #include "opt_ipsec.h" 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/malloc.h> 72 #include <sys/mbuf.h> 73 #include <sys/proc.h> 74 #include <sys/domain.h> 75 #include <sys/protosw.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/errno.h> 79 #include <sys/time.h> 80 #include <sys/kernel.h> 81 #include <sys/syslog.h> 82 83 #include <net/if.h> 84 #include <net/if_types.h> 85 #include <net/if_dl.h> 86 #include <net/route.h> 87 #include <net/netisr.h> 88 #include <net/pfil.h> 89 90 #include <netinet/in.h> 91 #include <netinet/in_systm.h> 92 #ifdef INET 93 #include <netinet/ip.h> 94 #include <netinet/ip_icmp.h> 95 #endif /* INET */ 96 #include <netinet/ip6.h> 97 #include <netinet6/in6_var.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet/in_pcb.h> 100 #include <netinet/icmp6.h> 101 #include <netinet6/scope6_var.h> 102 #include <netinet6/in6_ifattach.h> 103 #include <netinet6/nd6.h> 104 105 #ifdef IPSEC 106 #include <netinet6/ipsec.h> 107 #ifdef INET6 108 #include <netinet6/ipsec6.h> 109 #endif 110 #endif 111 112 #ifdef FAST_IPSEC 113 #include <netipsec/ipsec.h> 114 #include <netipsec/ipsec6.h> 115 #define IPSEC 116 #endif /* FAST_IPSEC */ 117 118 #include <netinet6/ip6_fw.h> 119 120 #include <netinet6/ip6protosw.h> 121 122 #include <net/net_osdep.h> 123 124 extern struct domain inet6domain; 125 126 u_char ip6_protox[IPPROTO_MAX]; 127 static struct ifqueue ip6intrq; 128 static int ip6qmaxlen = IFQ_MAXLEN; 129 struct in6_ifaddr *in6_ifaddr; 130 131 extern struct callout in6_tmpaddrtimer_ch; 132 133 int ip6_forward_srcrt; /* XXX */ 134 int ip6_sourcecheck; /* XXX */ 135 int ip6_sourcecheck_interval; /* XXX */ 136 137 int ip6_ours_check_algorithm; 138 139 struct pfil_head inet6_pfil_hook; 140 141 /* firewall hooks */ 142 ip6_fw_chk_t *ip6_fw_chk_ptr; 143 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 144 int ip6_fw_enable = 1; 145 146 struct ip6stat ip6stat; 147 148 static void ip6_init2 __P((void *)); 149 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 150 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 151 #ifdef PULLDOWN_TEST 152 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 153 #endif 154 155 /* 156 * IP6 initialization: fill in IP6 protocol switch table. 157 * All protocols not implemented in kernel go to raw IP6 protocol handler. 158 */ 159 void 160 ip6_init() 161 { 162 struct ip6protosw *pr; 163 int i; 164 165 #ifdef DIAGNOSTIC 166 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 167 panic("sizeof(protosw) != sizeof(ip6protosw)"); 168 #endif 169 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 170 if (pr == 0) 171 panic("ip6_init"); 172 for (i = 0; i < IPPROTO_MAX; i++) 173 ip6_protox[i] = pr - inet6sw; 174 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 175 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 176 if (pr->pr_domain->dom_family == PF_INET6 && 177 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 178 ip6_protox[pr->pr_protocol] = pr - inet6sw; 179 180 /* Initialize packet filter hooks. */ 181 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 182 inet6_pfil_hook.ph_af = AF_INET6; 183 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 184 printf("%s: WARNING: unable to register pfil hook, " 185 "error %d\n", __func__, i); 186 187 ip6intrq.ifq_maxlen = ip6qmaxlen; 188 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 189 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 190 scope6_init(); 191 addrsel_policy_init(); 192 nd6_init(); 193 frag6_init(); 194 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 195 } 196 197 static void 198 ip6_init2(dummy) 199 void *dummy; 200 { 201 202 /* nd6_timer_init */ 203 callout_init(&nd6_timer_ch, 0); 204 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 205 206 /* timer for regeneranation of temporary addresses randomize ID */ 207 callout_init(&in6_tmpaddrtimer_ch, 0); 208 callout_reset(&in6_tmpaddrtimer_ch, 209 (ip6_temp_preferred_lifetime - ip6_desync_factor - 210 ip6_temp_regen_advance) * hz, 211 in6_tmpaddrtimer, NULL); 212 } 213 214 /* cheat */ 215 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 216 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 217 218 extern struct route_in6 ip6_forward_rt; 219 220 void 221 ip6_input(m) 222 struct mbuf *m; 223 { 224 struct ip6_hdr *ip6; 225 int off = sizeof(struct ip6_hdr), nest; 226 u_int32_t plen; 227 u_int32_t rtalert = ~0; 228 int nxt, ours = 0; 229 struct ifnet *deliverifp = NULL; 230 struct sockaddr_in6 sa6; 231 u_int32_t srczone, dstzone; 232 struct in6_addr odst; 233 int srcrt = 0; 234 235 GIANT_REQUIRED; /* XXX for now */ 236 #ifdef IPSEC 237 /* 238 * should the inner packet be considered authentic? 239 * see comment in ah4_input(). 240 */ 241 if (m) { 242 m->m_flags &= ~M_AUTHIPHDR; 243 m->m_flags &= ~M_AUTHIPDGM; 244 } 245 #endif 246 247 /* 248 * make sure we don't have onion peering information into m_tag. 249 */ 250 ip6_delaux(m); 251 252 /* 253 * mbuf statistics 254 */ 255 if (m->m_flags & M_EXT) { 256 if (m->m_next) 257 ip6stat.ip6s_mext2m++; 258 else 259 ip6stat.ip6s_mext1++; 260 } else { 261 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 262 if (m->m_next) { 263 if (m->m_flags & M_LOOP) { 264 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 265 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 266 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 267 else 268 ip6stat.ip6s_m2m[0]++; 269 } else 270 ip6stat.ip6s_m1++; 271 #undef M2MMAX 272 } 273 274 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 275 ip6stat.ip6s_total++; 276 277 #ifndef PULLDOWN_TEST 278 /* 279 * L2 bridge code and some other code can return mbuf chain 280 * that does not conform to KAME requirement. too bad. 281 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 282 */ 283 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 284 struct mbuf *n; 285 286 MGETHDR(n, M_DONTWAIT, MT_HEADER); 287 if (n) 288 M_MOVE_PKTHDR(n, m); 289 if (n && n->m_pkthdr.len > MHLEN) { 290 MCLGET(n, M_DONTWAIT); 291 if ((n->m_flags & M_EXT) == 0) { 292 m_freem(n); 293 n = NULL; 294 } 295 } 296 if (n == NULL) { 297 m_freem(m); 298 return; /* ENOBUFS */ 299 } 300 301 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 302 n->m_len = n->m_pkthdr.len; 303 m_freem(m); 304 m = n; 305 } 306 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 307 #endif 308 309 if (m->m_len < sizeof(struct ip6_hdr)) { 310 struct ifnet *inifp; 311 inifp = m->m_pkthdr.rcvif; 312 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 313 ip6stat.ip6s_toosmall++; 314 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 315 return; 316 } 317 } 318 319 ip6 = mtod(m, struct ip6_hdr *); 320 321 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 322 ip6stat.ip6s_badvers++; 323 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 324 goto bad; 325 } 326 327 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 328 329 /* 330 * Check against address spoofing/corruption. 331 */ 332 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 333 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 334 /* 335 * XXX: "badscope" is not very suitable for a multicast source. 336 */ 337 ip6stat.ip6s_badscope++; 338 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 339 goto bad; 340 } 341 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 342 !(m->m_flags & M_LOOP)) { 343 /* 344 * In this case, the packet should come from the loopback 345 * interface. However, we cannot just check the if_flags, 346 * because ip6_mloopback() passes the "actual" interface 347 * as the outgoing/incoming interface. 348 */ 349 ip6stat.ip6s_badscope++; 350 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 351 goto bad; 352 } 353 354 #ifdef ALTQ 355 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 356 /* packet is dropped by traffic conditioner */ 357 return; 358 } 359 #endif 360 /* 361 * The following check is not documented in specs. A malicious 362 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 363 * and bypass security checks (act as if it was from 127.0.0.1 by using 364 * IPv6 src ::ffff:127.0.0.1). Be cautious. 365 * 366 * This check chokes if we are in an SIIT cloud. As none of BSDs 367 * support IPv4-less kernel compilation, we cannot support SIIT 368 * environment at all. So, it makes more sense for us to reject any 369 * malicious packets for non-SIIT environment, than try to do a 370 * partial support for SIIT environment. 371 */ 372 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 373 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 374 ip6stat.ip6s_badscope++; 375 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 376 goto bad; 377 } 378 #if 0 379 /* 380 * Reject packets with IPv4 compatible addresses (auto tunnel). 381 * 382 * The code forbids auto tunnel relay case in RFC1933 (the check is 383 * stronger than RFC1933). We may want to re-enable it if mech-xx 384 * is revised to forbid relaying case. 385 */ 386 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 387 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 388 ip6stat.ip6s_badscope++; 389 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 390 goto bad; 391 } 392 #endif 393 394 /* 395 * Drop packets if the link ID portion is already filled. 396 * XXX: this is technically not a good behavior. But, we internally 397 * use the field to disambiguate link-local addresses, so we cannot 398 * be generous against those a bit strange addresses. 399 */ 400 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 401 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 402 ip6->ip6_src.s6_addr16[1]) { 403 ip6stat.ip6s_badscope++; 404 goto bad; 405 } 406 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 407 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 408 ip6->ip6_dst.s6_addr16[1]) { 409 ip6stat.ip6s_badscope++; 410 goto bad; 411 } 412 } 413 414 /* 415 * Run through list of hooks for input packets. 416 * 417 * NB: Beware of the destination address changing 418 * (e.g. by NAT rewriting). When this happens, 419 * tell ip6_forward to do the right thing. 420 */ 421 odst = ip6->ip6_dst; 422 423 /* Jump over all PFIL processing if hooks are not active. */ 424 if (inet6_pfil_hook.ph_busy_count == -1) 425 goto passin; 426 427 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 428 return; 429 if (m == NULL) /* consumed by filter */ 430 return; 431 ip6 = mtod(m, struct ip6_hdr *); 432 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 433 434 passin: 435 /* 436 * Check with the firewall... 437 */ 438 if (ip6_fw_enable && ip6_fw_chk_ptr) { 439 u_short port = 0; 440 /* If ipfw says divert, we have to just drop packet */ 441 /* use port as a dummy argument */ 442 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 443 m_freem(m); 444 m = NULL; 445 } 446 if (!m) 447 return; 448 } 449 450 /* 451 * construct source and destination address structures with 452 * disambiguating their scope zones (if there is ambiguity). 453 * XXX: sin6_family and sin6_len will NOT be referred to, but we fill 454 * in these fields just in case. 455 */ 456 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_src, &srczone) || 457 in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst, &dstzone)) { 458 /* 459 * Note that these generic checks cover cases that src or 460 * dst are the loopback address and the receiving interface 461 * is not loopback. 462 */ 463 ip6stat.ip6s_badscope++; 464 goto bad; 465 } 466 467 bzero(&sa6, sizeof(sa6)); 468 sa6.sin6_family = AF_INET6; 469 sa6.sin6_len = sizeof(struct sockaddr_in6); 470 471 sa6.sin6_addr = ip6->ip6_src; 472 sa6.sin6_scope_id = srczone; 473 if (in6_embedscope(&ip6->ip6_src, &sa6, NULL, NULL)) { 474 /* XXX: should not happen */ 475 ip6stat.ip6s_badscope++; 476 goto bad; 477 } 478 479 sa6.sin6_addr = ip6->ip6_dst; 480 sa6.sin6_scope_id = dstzone; 481 if (in6_embedscope(&ip6->ip6_dst, &sa6, NULL, NULL)) { 482 /* XXX: should not happen */ 483 ip6stat.ip6s_badscope++; 484 goto bad; 485 } 486 487 /* XXX: ff01::%ifN awareness is not merged, yet. */ 488 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_src)) 489 ip6->ip6_src.s6_addr16[1] = 0; 490 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) 491 ip6->ip6_dst.s6_addr16[1] = 0; 492 493 /* 494 * Multicast check 495 */ 496 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 497 struct in6_multi *in6m = 0; 498 499 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 500 /* 501 * See if we belong to the destination multicast group on the 502 * arrival interface. 503 */ 504 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 505 if (in6m) 506 ours = 1; 507 else if (!ip6_mrouter) { 508 ip6stat.ip6s_notmember++; 509 ip6stat.ip6s_cantforward++; 510 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 511 goto bad; 512 } 513 deliverifp = m->m_pkthdr.rcvif; 514 goto hbhcheck; 515 } 516 517 /* 518 * Unicast check 519 */ 520 if (ip6_forward_rt.ro_rt != NULL && 521 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 522 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 523 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 524 ip6stat.ip6s_forward_cachehit++; 525 else { 526 struct sockaddr_in6 *dst6; 527 528 if (ip6_forward_rt.ro_rt) { 529 /* route is down or destination is different */ 530 ip6stat.ip6s_forward_cachemiss++; 531 RTFREE(ip6_forward_rt.ro_rt); 532 ip6_forward_rt.ro_rt = 0; 533 } 534 535 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 536 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 537 dst6->sin6_len = sizeof(struct sockaddr_in6); 538 dst6->sin6_family = AF_INET6; 539 dst6->sin6_addr = ip6->ip6_dst; 540 541 rtalloc((struct route *)&ip6_forward_rt); 542 } 543 544 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 545 546 /* 547 * Accept the packet if the forwarding interface to the destination 548 * according to the routing table is the loopback interface, 549 * unless the associated route has a gateway. 550 * Note that this approach causes to accept a packet if there is a 551 * route to the loopback interface for the destination of the packet. 552 * But we think it's even useful in some situations, e.g. when using 553 * a special daemon which wants to intercept the packet. 554 * 555 * XXX: some OSes automatically make a cloned route for the destination 556 * of an outgoing packet. If the outgoing interface of the packet 557 * is a loopback one, the kernel would consider the packet to be 558 * accepted, even if we have no such address assinged on the interface. 559 * We check the cloned flag of the route entry to reject such cases, 560 * assuming that route entries for our own addresses are not made by 561 * cloning (it should be true because in6_addloop explicitly installs 562 * the host route). However, we might have to do an explicit check 563 * while it would be less efficient. Or, should we rather install a 564 * reject route for such a case? 565 */ 566 if (ip6_forward_rt.ro_rt && 567 (ip6_forward_rt.ro_rt->rt_flags & 568 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 569 #ifdef RTF_WASCLONED 570 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 571 #endif 572 #ifdef RTF_CLONED 573 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 574 #endif 575 #if 0 576 /* 577 * The check below is redundant since the comparison of 578 * the destination and the key of the rtentry has 579 * already done through looking up the routing table. 580 */ 581 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 582 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 583 #endif 584 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 585 struct in6_ifaddr *ia6 = 586 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 587 588 /* 589 * record address information into m_tag. 590 */ 591 (void)ip6_setdstifaddr(m, ia6); 592 593 /* 594 * packets to a tentative, duplicated, or somehow invalid 595 * address must not be accepted. 596 */ 597 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 598 /* this address is ready */ 599 ours = 1; 600 deliverifp = ia6->ia_ifp; /* correct? */ 601 /* Count the packet in the ip address stats */ 602 ia6->ia_ifa.if_ipackets++; 603 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 604 goto hbhcheck; 605 } else { 606 /* address is not ready, so discard the packet. */ 607 nd6log((LOG_INFO, 608 "ip6_input: packet to an unready address %s->%s\n", 609 ip6_sprintf(&ip6->ip6_src), 610 ip6_sprintf(&ip6->ip6_dst))); 611 612 goto bad; 613 } 614 } 615 616 /* 617 * FAITH (Firewall Aided Internet Translator) 618 */ 619 if (ip6_keepfaith) { 620 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 621 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 622 /* XXX do we need more sanity checks? */ 623 ours = 1; 624 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 625 goto hbhcheck; 626 } 627 } 628 629 /* 630 * Now there is no reason to process the packet if it's not our own 631 * and we're not a router. 632 */ 633 if (!ip6_forwarding) { 634 ip6stat.ip6s_cantforward++; 635 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 636 goto bad; 637 } 638 639 hbhcheck: 640 /* 641 * record address information into m_tag, if we don't have one yet. 642 * note that we are unable to record it, if the address is not listed 643 * as our interface address (e.g. multicast addresses, addresses 644 * within FAITH prefixes and such). 645 */ 646 if (deliverifp && !ip6_getdstifaddr(m)) { 647 struct in6_ifaddr *ia6; 648 649 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 650 if (ia6) { 651 if (!ip6_setdstifaddr(m, ia6)) { 652 /* 653 * XXX maybe we should drop the packet here, 654 * as we could not provide enough information 655 * to the upper layers. 656 */ 657 } 658 } 659 } 660 661 /* 662 * Process Hop-by-Hop options header if it's contained. 663 * m may be modified in ip6_hopopts_input(). 664 * If a JumboPayload option is included, plen will also be modified. 665 */ 666 plen = (u_int32_t)ntohs(ip6->ip6_plen); 667 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 668 struct ip6_hbh *hbh; 669 670 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 671 #if 0 /*touches NULL pointer*/ 672 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 673 #endif 674 return; /* m have already been freed */ 675 } 676 677 /* adjust pointer */ 678 ip6 = mtod(m, struct ip6_hdr *); 679 680 /* 681 * if the payload length field is 0 and the next header field 682 * indicates Hop-by-Hop Options header, then a Jumbo Payload 683 * option MUST be included. 684 */ 685 if (ip6->ip6_plen == 0 && plen == 0) { 686 /* 687 * Note that if a valid jumbo payload option is 688 * contained, ip6_hopopts_input() must set a valid 689 * (non-zero) payload length to the variable plen. 690 */ 691 ip6stat.ip6s_badoptions++; 692 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 693 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 694 icmp6_error(m, ICMP6_PARAM_PROB, 695 ICMP6_PARAMPROB_HEADER, 696 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 697 return; 698 } 699 #ifndef PULLDOWN_TEST 700 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 701 hbh = (struct ip6_hbh *)(ip6 + 1); 702 #else 703 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 704 sizeof(struct ip6_hbh)); 705 if (hbh == NULL) { 706 ip6stat.ip6s_tooshort++; 707 return; 708 } 709 #endif 710 nxt = hbh->ip6h_nxt; 711 712 /* 713 * accept the packet if a router alert option is included 714 * and we act as an IPv6 router. 715 */ 716 if (rtalert != ~0 && ip6_forwarding) 717 ours = 1; 718 } else 719 nxt = ip6->ip6_nxt; 720 721 /* 722 * Check that the amount of data in the buffers 723 * is as at least much as the IPv6 header would have us expect. 724 * Trim mbufs if longer than we expect. 725 * Drop packet if shorter than we expect. 726 */ 727 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 728 ip6stat.ip6s_tooshort++; 729 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 730 goto bad; 731 } 732 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 733 if (m->m_len == m->m_pkthdr.len) { 734 m->m_len = sizeof(struct ip6_hdr) + plen; 735 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 736 } else 737 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 738 } 739 740 /* 741 * Forward if desirable. 742 */ 743 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 744 /* 745 * If we are acting as a multicast router, all 746 * incoming multicast packets are passed to the 747 * kernel-level multicast forwarding function. 748 * The packet is returned (relatively) intact; if 749 * ip6_mforward() returns a non-zero value, the packet 750 * must be discarded, else it may be accepted below. 751 */ 752 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 753 ip6stat.ip6s_cantforward++; 754 m_freem(m); 755 return; 756 } 757 if (!ours) { 758 m_freem(m); 759 return; 760 } 761 } else if (!ours) { 762 ip6_forward(m, srcrt); 763 return; 764 } 765 766 ip6 = mtod(m, struct ip6_hdr *); 767 768 /* 769 * Malicious party may be able to use IPv4 mapped addr to confuse 770 * tcp/udp stack and bypass security checks (act as if it was from 771 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 772 * 773 * For SIIT end node behavior, you may want to disable the check. 774 * However, you will become vulnerable to attacks using IPv4 mapped 775 * source. 776 */ 777 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 778 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 779 ip6stat.ip6s_badscope++; 780 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 781 goto bad; 782 } 783 784 /* 785 * Tell launch routine the next header 786 */ 787 ip6stat.ip6s_delivered++; 788 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 789 nest = 0; 790 791 while (nxt != IPPROTO_DONE) { 792 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 793 ip6stat.ip6s_toomanyhdr++; 794 goto bad; 795 } 796 797 /* 798 * protection against faulty packet - there should be 799 * more sanity checks in header chain processing. 800 */ 801 if (m->m_pkthdr.len < off) { 802 ip6stat.ip6s_tooshort++; 803 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 804 goto bad; 805 } 806 807 #ifdef IPSEC 808 /* 809 * enforce IPsec policy checking if we are seeing last header. 810 * note that we do not visit this with protocols with pcb layer 811 * code - like udp/tcp/raw ip. 812 */ 813 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 814 ipsec6_in_reject(m, NULL)) { 815 ipsec6stat.in_polvio++; 816 goto bad; 817 } 818 #endif 819 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 820 } 821 return; 822 bad: 823 m_freem(m); 824 } 825 826 /* 827 * set/grab in6_ifaddr correspond to IPv6 destination address. 828 * XXX backward compatibility wrapper 829 */ 830 static struct ip6aux * 831 ip6_setdstifaddr(m, ia6) 832 struct mbuf *m; 833 struct in6_ifaddr *ia6; 834 { 835 struct ip6aux *ip6a; 836 837 ip6a = ip6_addaux(m); 838 if (ip6a) 839 ip6a->ip6a_dstia6 = ia6; 840 return ip6a; /* NULL if failed to set */ 841 } 842 843 struct in6_ifaddr * 844 ip6_getdstifaddr(m) 845 struct mbuf *m; 846 { 847 struct ip6aux *ip6a; 848 849 ip6a = ip6_findaux(m); 850 if (ip6a) 851 return ip6a->ip6a_dstia6; 852 else 853 return NULL; 854 } 855 856 /* 857 * Hop-by-Hop options header processing. If a valid jumbo payload option is 858 * included, the real payload length will be stored in plenp. 859 */ 860 static int 861 ip6_hopopts_input(plenp, rtalertp, mp, offp) 862 u_int32_t *plenp; 863 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 864 struct mbuf **mp; 865 int *offp; 866 { 867 struct mbuf *m = *mp; 868 int off = *offp, hbhlen; 869 struct ip6_hbh *hbh; 870 u_int8_t *opt; 871 872 /* validation of the length of the header */ 873 #ifndef PULLDOWN_TEST 874 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 875 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 876 hbhlen = (hbh->ip6h_len + 1) << 3; 877 878 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 879 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 880 #else 881 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 882 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 883 if (hbh == NULL) { 884 ip6stat.ip6s_tooshort++; 885 return -1; 886 } 887 hbhlen = (hbh->ip6h_len + 1) << 3; 888 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 889 hbhlen); 890 if (hbh == NULL) { 891 ip6stat.ip6s_tooshort++; 892 return -1; 893 } 894 #endif 895 off += hbhlen; 896 hbhlen -= sizeof(struct ip6_hbh); 897 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 898 899 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 900 hbhlen, rtalertp, plenp) < 0) 901 return (-1); 902 903 *offp = off; 904 *mp = m; 905 return (0); 906 } 907 908 /* 909 * Search header for all Hop-by-hop options and process each option. 910 * This function is separate from ip6_hopopts_input() in order to 911 * handle a case where the sending node itself process its hop-by-hop 912 * options header. In such a case, the function is called from ip6_output(). 913 * 914 * The function assumes that hbh header is located right after the IPv6 header 915 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 916 * opthead + hbhlen is located in continuous memory region. 917 */ 918 int 919 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 920 struct mbuf *m; 921 u_int8_t *opthead; 922 int hbhlen; 923 u_int32_t *rtalertp; 924 u_int32_t *plenp; 925 { 926 struct ip6_hdr *ip6; 927 int optlen = 0; 928 u_int8_t *opt = opthead; 929 u_int16_t rtalert_val; 930 u_int32_t jumboplen; 931 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 932 933 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 934 switch (*opt) { 935 case IP6OPT_PAD1: 936 optlen = 1; 937 break; 938 case IP6OPT_PADN: 939 if (hbhlen < IP6OPT_MINLEN) { 940 ip6stat.ip6s_toosmall++; 941 goto bad; 942 } 943 optlen = *(opt + 1) + 2; 944 break; 945 case IP6OPT_ROUTER_ALERT: 946 /* XXX may need check for alignment */ 947 if (hbhlen < IP6OPT_RTALERT_LEN) { 948 ip6stat.ip6s_toosmall++; 949 goto bad; 950 } 951 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 952 /* XXX stat */ 953 icmp6_error(m, ICMP6_PARAM_PROB, 954 ICMP6_PARAMPROB_HEADER, 955 erroff + opt + 1 - opthead); 956 return (-1); 957 } 958 optlen = IP6OPT_RTALERT_LEN; 959 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 960 *rtalertp = ntohs(rtalert_val); 961 break; 962 case IP6OPT_JUMBO: 963 /* XXX may need check for alignment */ 964 if (hbhlen < IP6OPT_JUMBO_LEN) { 965 ip6stat.ip6s_toosmall++; 966 goto bad; 967 } 968 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 969 /* XXX stat */ 970 icmp6_error(m, ICMP6_PARAM_PROB, 971 ICMP6_PARAMPROB_HEADER, 972 erroff + opt + 1 - opthead); 973 return (-1); 974 } 975 optlen = IP6OPT_JUMBO_LEN; 976 977 /* 978 * IPv6 packets that have non 0 payload length 979 * must not contain a jumbo payload option. 980 */ 981 ip6 = mtod(m, struct ip6_hdr *); 982 if (ip6->ip6_plen) { 983 ip6stat.ip6s_badoptions++; 984 icmp6_error(m, ICMP6_PARAM_PROB, 985 ICMP6_PARAMPROB_HEADER, 986 erroff + opt - opthead); 987 return (-1); 988 } 989 990 /* 991 * We may see jumbolen in unaligned location, so 992 * we'd need to perform bcopy(). 993 */ 994 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 995 jumboplen = (u_int32_t)htonl(jumboplen); 996 997 #if 1 998 /* 999 * if there are multiple jumbo payload options, 1000 * *plenp will be non-zero and the packet will be 1001 * rejected. 1002 * the behavior may need some debate in ipngwg - 1003 * multiple options does not make sense, however, 1004 * there's no explicit mention in specification. 1005 */ 1006 if (*plenp != 0) { 1007 ip6stat.ip6s_badoptions++; 1008 icmp6_error(m, ICMP6_PARAM_PROB, 1009 ICMP6_PARAMPROB_HEADER, 1010 erroff + opt + 2 - opthead); 1011 return (-1); 1012 } 1013 #endif 1014 1015 /* 1016 * jumbo payload length must be larger than 65535. 1017 */ 1018 if (jumboplen <= IPV6_MAXPACKET) { 1019 ip6stat.ip6s_badoptions++; 1020 icmp6_error(m, ICMP6_PARAM_PROB, 1021 ICMP6_PARAMPROB_HEADER, 1022 erroff + opt + 2 - opthead); 1023 return (-1); 1024 } 1025 *plenp = jumboplen; 1026 1027 break; 1028 default: /* unknown option */ 1029 if (hbhlen < IP6OPT_MINLEN) { 1030 ip6stat.ip6s_toosmall++; 1031 goto bad; 1032 } 1033 optlen = ip6_unknown_opt(opt, m, 1034 erroff + opt - opthead); 1035 if (optlen == -1) 1036 return (-1); 1037 optlen += 2; 1038 break; 1039 } 1040 } 1041 1042 return (0); 1043 1044 bad: 1045 m_freem(m); 1046 return (-1); 1047 } 1048 1049 /* 1050 * Unknown option processing. 1051 * The third argument `off' is the offset from the IPv6 header to the option, 1052 * which is necessary if the IPv6 header the and option header and IPv6 header 1053 * is not continuous in order to return an ICMPv6 error. 1054 */ 1055 int 1056 ip6_unknown_opt(optp, m, off) 1057 u_int8_t *optp; 1058 struct mbuf *m; 1059 int off; 1060 { 1061 struct ip6_hdr *ip6; 1062 1063 switch (IP6OPT_TYPE(*optp)) { 1064 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1065 return ((int)*(optp + 1)); 1066 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1067 m_freem(m); 1068 return (-1); 1069 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1070 ip6stat.ip6s_badoptions++; 1071 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1072 return (-1); 1073 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1074 ip6stat.ip6s_badoptions++; 1075 ip6 = mtod(m, struct ip6_hdr *); 1076 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1077 (m->m_flags & (M_BCAST|M_MCAST))) 1078 m_freem(m); 1079 else 1080 icmp6_error(m, ICMP6_PARAM_PROB, 1081 ICMP6_PARAMPROB_OPTION, off); 1082 return (-1); 1083 } 1084 1085 m_freem(m); /* XXX: NOTREACHED */ 1086 return (-1); 1087 } 1088 1089 /* 1090 * Create the "control" list for this pcb. 1091 * The function will not modify mbuf chain at all. 1092 * 1093 * with KAME mbuf chain restriction: 1094 * The routine will be called from upper layer handlers like tcp6_input(). 1095 * Thus the routine assumes that the caller (tcp6_input) have already 1096 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1097 * very first mbuf on the mbuf chain. 1098 */ 1099 void 1100 ip6_savecontrol(in6p, m, mp) 1101 struct inpcb *in6p; 1102 struct mbuf *m, **mp; 1103 { 1104 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1105 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1106 1107 #ifdef SO_TIMESTAMP 1108 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1109 struct timeval tv; 1110 1111 microtime(&tv); 1112 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1113 SCM_TIMESTAMP, SOL_SOCKET); 1114 if (*mp) 1115 mp = &(*mp)->m_next; 1116 } 1117 #endif 1118 1119 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1120 return; 1121 1122 /* RFC 2292 sec. 5 */ 1123 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1124 struct in6_pktinfo pi6; 1125 1126 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1127 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1128 pi6.ipi6_ifindex = 1129 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1130 1131 *mp = sbcreatecontrol((caddr_t) &pi6, 1132 sizeof(struct in6_pktinfo), 1133 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1134 if (*mp) 1135 mp = &(*mp)->m_next; 1136 } 1137 1138 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1139 int hlim = ip6->ip6_hlim & 0xff; 1140 1141 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1142 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1143 if (*mp) 1144 mp = &(*mp)->m_next; 1145 } 1146 1147 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1148 u_int32_t flowinfo; 1149 int tclass; 1150 1151 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1152 flowinfo >>= 20; 1153 1154 tclass = flowinfo & 0xff; 1155 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1156 IPV6_TCLASS, IPPROTO_IPV6); 1157 if (*mp) 1158 mp = &(*mp)->m_next; 1159 } 1160 1161 /* 1162 * IPV6_HOPOPTS socket option. Recall that we required super-user 1163 * privilege for the option (see ip6_ctloutput), but it might be too 1164 * strict, since there might be some hop-by-hop options which can be 1165 * returned to normal user. 1166 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1167 */ 1168 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1169 /* 1170 * Check if a hop-by-hop options header is contatined in the 1171 * received packet, and if so, store the options as ancillary 1172 * data. Note that a hop-by-hop options header must be 1173 * just after the IPv6 header, which is assured through the 1174 * IPv6 input processing. 1175 */ 1176 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1177 struct ip6_hbh *hbh; 1178 int hbhlen = 0; 1179 #ifdef PULLDOWN_TEST 1180 struct mbuf *ext; 1181 #endif 1182 1183 #ifndef PULLDOWN_TEST 1184 hbh = (struct ip6_hbh *)(ip6 + 1); 1185 hbhlen = (hbh->ip6h_len + 1) << 3; 1186 #else 1187 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1188 ip6->ip6_nxt); 1189 if (ext == NULL) { 1190 ip6stat.ip6s_tooshort++; 1191 return; 1192 } 1193 hbh = mtod(ext, struct ip6_hbh *); 1194 hbhlen = (hbh->ip6h_len + 1) << 3; 1195 if (hbhlen != ext->m_len) { 1196 m_freem(ext); 1197 ip6stat.ip6s_tooshort++; 1198 return; 1199 } 1200 #endif 1201 1202 /* 1203 * XXX: We copy the whole header even if a 1204 * jumbo payload option is included, the option which 1205 * is to be removed before returning according to 1206 * RFC2292. 1207 * Note: this constraint is removed in 2292bis. 1208 */ 1209 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1210 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1211 IPPROTO_IPV6); 1212 if (*mp) 1213 mp = &(*mp)->m_next; 1214 #ifdef PULLDOWN_TEST 1215 m_freem(ext); 1216 #endif 1217 } 1218 } 1219 1220 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1221 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1222 1223 /* 1224 * Search for destination options headers or routing 1225 * header(s) through the header chain, and stores each 1226 * header as ancillary data. 1227 * Note that the order of the headers remains in 1228 * the chain of ancillary data. 1229 */ 1230 while (1) { /* is explicit loop prevention necessary? */ 1231 struct ip6_ext *ip6e = NULL; 1232 int elen; 1233 #ifdef PULLDOWN_TEST 1234 struct mbuf *ext = NULL; 1235 #endif 1236 1237 /* 1238 * if it is not an extension header, don't try to 1239 * pull it from the chain. 1240 */ 1241 switch (nxt) { 1242 case IPPROTO_DSTOPTS: 1243 case IPPROTO_ROUTING: 1244 case IPPROTO_HOPOPTS: 1245 case IPPROTO_AH: /* is it possible? */ 1246 break; 1247 default: 1248 goto loopend; 1249 } 1250 1251 #ifndef PULLDOWN_TEST 1252 if (off + sizeof(*ip6e) > m->m_len) 1253 goto loopend; 1254 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1255 if (nxt == IPPROTO_AH) 1256 elen = (ip6e->ip6e_len + 2) << 2; 1257 else 1258 elen = (ip6e->ip6e_len + 1) << 3; 1259 if (off + elen > m->m_len) 1260 goto loopend; 1261 #else 1262 ext = ip6_pullexthdr(m, off, nxt); 1263 if (ext == NULL) { 1264 ip6stat.ip6s_tooshort++; 1265 return; 1266 } 1267 ip6e = mtod(ext, struct ip6_ext *); 1268 if (nxt == IPPROTO_AH) 1269 elen = (ip6e->ip6e_len + 2) << 2; 1270 else 1271 elen = (ip6e->ip6e_len + 1) << 3; 1272 if (elen != ext->m_len) { 1273 m_freem(ext); 1274 ip6stat.ip6s_tooshort++; 1275 return; 1276 } 1277 #endif 1278 1279 switch (nxt) { 1280 case IPPROTO_DSTOPTS: 1281 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1282 break; 1283 1284 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1285 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1286 IPPROTO_IPV6); 1287 if (*mp) 1288 mp = &(*mp)->m_next; 1289 break; 1290 case IPPROTO_ROUTING: 1291 if (!in6p->in6p_flags & IN6P_RTHDR) 1292 break; 1293 1294 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1295 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1296 IPPROTO_IPV6); 1297 if (*mp) 1298 mp = &(*mp)->m_next; 1299 break; 1300 case IPPROTO_HOPOPTS: 1301 case IPPROTO_AH: /* is it possible? */ 1302 break; 1303 1304 default: 1305 /* 1306 * other cases have been filtered in the above. 1307 * none will visit this case. here we supply 1308 * the code just in case (nxt overwritten or 1309 * other cases). 1310 */ 1311 #ifdef PULLDOWN_TEST 1312 m_freem(ext); 1313 #endif 1314 goto loopend; 1315 1316 } 1317 1318 /* proceed with the next header. */ 1319 off += elen; 1320 nxt = ip6e->ip6e_nxt; 1321 ip6e = NULL; 1322 #ifdef PULLDOWN_TEST 1323 m_freem(ext); 1324 ext = NULL; 1325 #endif 1326 } 1327 loopend: 1328 ; 1329 } 1330 1331 #undef IS2292 1332 } 1333 1334 void 1335 ip6_notify_pmtu(in6p, dst, mtu) 1336 struct inpcb *in6p; 1337 struct sockaddr_in6 *dst; 1338 u_int32_t *mtu; 1339 { 1340 struct socket *so; 1341 struct mbuf *m_mtu; 1342 struct ip6_mtuinfo mtuctl; 1343 1344 so = in6p->inp_socket; 1345 1346 if (mtu == NULL) 1347 return; 1348 1349 #ifdef DIAGNOSTIC 1350 if (so == NULL) /* I believe this is impossible */ 1351 panic("ip6_notify_pmtu: socket is NULL"); 1352 #endif 1353 1354 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1355 mtuctl.ip6m_mtu = *mtu; 1356 mtuctl.ip6m_addr = *dst; 1357 in6_recoverscope(&mtuctl.ip6m_addr, &mtuctl.ip6m_addr.sin6_addr, NULL); 1358 1359 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1360 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1361 return; 1362 1363 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1364 == 0) { 1365 m_freem(m_mtu); 1366 /* XXX: should count statistics */ 1367 } else 1368 sorwakeup(so); 1369 1370 return; 1371 } 1372 1373 #ifdef PULLDOWN_TEST 1374 /* 1375 * pull single extension header from mbuf chain. returns single mbuf that 1376 * contains the result, or NULL on error. 1377 */ 1378 static struct mbuf * 1379 ip6_pullexthdr(m, off, nxt) 1380 struct mbuf *m; 1381 size_t off; 1382 int nxt; 1383 { 1384 struct ip6_ext ip6e; 1385 size_t elen; 1386 struct mbuf *n; 1387 1388 #ifdef DIAGNOSTIC 1389 switch (nxt) { 1390 case IPPROTO_DSTOPTS: 1391 case IPPROTO_ROUTING: 1392 case IPPROTO_HOPOPTS: 1393 case IPPROTO_AH: /* is it possible? */ 1394 break; 1395 default: 1396 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1397 } 1398 #endif 1399 1400 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1401 if (nxt == IPPROTO_AH) 1402 elen = (ip6e.ip6e_len + 2) << 2; 1403 else 1404 elen = (ip6e.ip6e_len + 1) << 3; 1405 1406 MGET(n, M_DONTWAIT, MT_DATA); 1407 if (n && elen >= MLEN) { 1408 MCLGET(n, M_DONTWAIT); 1409 if ((n->m_flags & M_EXT) == 0) { 1410 m_free(n); 1411 n = NULL; 1412 } 1413 } 1414 if (!n) 1415 return NULL; 1416 1417 n->m_len = 0; 1418 if (elen >= M_TRAILINGSPACE(n)) { 1419 m_free(n); 1420 return NULL; 1421 } 1422 1423 m_copydata(m, off, elen, mtod(n, caddr_t)); 1424 n->m_len = elen; 1425 return n; 1426 } 1427 #endif 1428 1429 /* 1430 * Get pointer to the previous header followed by the header 1431 * currently processed. 1432 * XXX: This function supposes that 1433 * M includes all headers, 1434 * the next header field and the header length field of each header 1435 * are valid, and 1436 * the sum of each header length equals to OFF. 1437 * Because of these assumptions, this function must be called very 1438 * carefully. Moreover, it will not be used in the near future when 1439 * we develop `neater' mechanism to process extension headers. 1440 */ 1441 char * 1442 ip6_get_prevhdr(m, off) 1443 struct mbuf *m; 1444 int off; 1445 { 1446 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1447 1448 if (off == sizeof(struct ip6_hdr)) 1449 return (&ip6->ip6_nxt); 1450 else { 1451 int len, nxt; 1452 struct ip6_ext *ip6e = NULL; 1453 1454 nxt = ip6->ip6_nxt; 1455 len = sizeof(struct ip6_hdr); 1456 while (len < off) { 1457 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1458 1459 switch (nxt) { 1460 case IPPROTO_FRAGMENT: 1461 len += sizeof(struct ip6_frag); 1462 break; 1463 case IPPROTO_AH: 1464 len += (ip6e->ip6e_len + 2) << 2; 1465 break; 1466 default: 1467 len += (ip6e->ip6e_len + 1) << 3; 1468 break; 1469 } 1470 nxt = ip6e->ip6e_nxt; 1471 } 1472 if (ip6e) 1473 return (&ip6e->ip6e_nxt); 1474 else 1475 return NULL; 1476 } 1477 } 1478 1479 /* 1480 * get next header offset. m will be retained. 1481 */ 1482 int 1483 ip6_nexthdr(m, off, proto, nxtp) 1484 struct mbuf *m; 1485 int off; 1486 int proto; 1487 int *nxtp; 1488 { 1489 struct ip6_hdr ip6; 1490 struct ip6_ext ip6e; 1491 struct ip6_frag fh; 1492 1493 /* just in case */ 1494 if (m == NULL) 1495 panic("ip6_nexthdr: m == NULL"); 1496 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1497 return -1; 1498 1499 switch (proto) { 1500 case IPPROTO_IPV6: 1501 if (m->m_pkthdr.len < off + sizeof(ip6)) 1502 return -1; 1503 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1504 if (nxtp) 1505 *nxtp = ip6.ip6_nxt; 1506 off += sizeof(ip6); 1507 return off; 1508 1509 case IPPROTO_FRAGMENT: 1510 /* 1511 * terminate parsing if it is not the first fragment, 1512 * it does not make sense to parse through it. 1513 */ 1514 if (m->m_pkthdr.len < off + sizeof(fh)) 1515 return -1; 1516 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1517 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1518 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1519 return -1; 1520 if (nxtp) 1521 *nxtp = fh.ip6f_nxt; 1522 off += sizeof(struct ip6_frag); 1523 return off; 1524 1525 case IPPROTO_AH: 1526 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1527 return -1; 1528 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1529 if (nxtp) 1530 *nxtp = ip6e.ip6e_nxt; 1531 off += (ip6e.ip6e_len + 2) << 2; 1532 return off; 1533 1534 case IPPROTO_HOPOPTS: 1535 case IPPROTO_ROUTING: 1536 case IPPROTO_DSTOPTS: 1537 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1538 return -1; 1539 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1540 if (nxtp) 1541 *nxtp = ip6e.ip6e_nxt; 1542 off += (ip6e.ip6e_len + 1) << 3; 1543 return off; 1544 1545 case IPPROTO_NONE: 1546 case IPPROTO_ESP: 1547 case IPPROTO_IPCOMP: 1548 /* give up */ 1549 return -1; 1550 1551 default: 1552 return -1; 1553 } 1554 1555 return -1; 1556 } 1557 1558 /* 1559 * get offset for the last header in the chain. m will be kept untainted. 1560 */ 1561 int 1562 ip6_lasthdr(m, off, proto, nxtp) 1563 struct mbuf *m; 1564 int off; 1565 int proto; 1566 int *nxtp; 1567 { 1568 int newoff; 1569 int nxt; 1570 1571 if (!nxtp) { 1572 nxt = -1; 1573 nxtp = &nxt; 1574 } 1575 while (1) { 1576 newoff = ip6_nexthdr(m, off, proto, nxtp); 1577 if (newoff < 0) 1578 return off; 1579 else if (newoff < off) 1580 return -1; /* invalid */ 1581 else if (newoff == off) 1582 return newoff; 1583 1584 off = newoff; 1585 proto = *nxtp; 1586 } 1587 } 1588 1589 struct ip6aux * 1590 ip6_addaux(m) 1591 struct mbuf *m; 1592 { 1593 struct m_tag *mtag; 1594 1595 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1596 if (!mtag) { 1597 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1598 M_NOWAIT); 1599 if (mtag) { 1600 m_tag_prepend(m, mtag); 1601 bzero(mtag + 1, sizeof(struct ip6aux)); 1602 } 1603 } 1604 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1605 } 1606 1607 struct ip6aux * 1608 ip6_findaux(m) 1609 struct mbuf *m; 1610 { 1611 struct m_tag *mtag; 1612 1613 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1614 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1615 } 1616 1617 void 1618 ip6_delaux(m) 1619 struct mbuf *m; 1620 { 1621 struct m_tag *mtag; 1622 1623 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1624 if (mtag) 1625 m_tag_delete(m, mtag); 1626 } 1627 1628 /* 1629 * System control for IP6 1630 */ 1631 1632 u_char inet6ctlerrmap[PRC_NCMDS] = { 1633 0, 0, 0, 0, 1634 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1635 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1636 EMSGSIZE, EHOSTUNREACH, 0, 0, 1637 0, 0, 0, 0, 1638 ENOPROTOOPT 1639 }; 1640