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 #include "opt_pfil_hooks.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/proc.h> 75 #include <sys/domain.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/kernel.h> 82 #include <sys/syslog.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 #ifdef PFIL_HOOKS 90 #include <net/pfil.h> 91 #endif 92 93 #include <netinet/in.h> 94 #include <netinet/in_systm.h> 95 #ifdef INET 96 #include <netinet/ip.h> 97 #include <netinet/ip_icmp.h> 98 #endif /* INET */ 99 #include <netinet/ip6.h> 100 #include <netinet6/in6_var.h> 101 #include <netinet6/ip6_var.h> 102 #include <netinet/in_pcb.h> 103 #include <netinet/icmp6.h> 104 #include <netinet6/scope6_var.h> 105 #include <netinet6/in6_ifattach.h> 106 #include <netinet6/nd6.h> 107 #include <netinet6/in6_prefix.h> 108 109 #ifdef IPSEC 110 #include <netinet6/ipsec.h> 111 #ifdef INET6 112 #include <netinet6/ipsec6.h> 113 #endif 114 #endif 115 116 #ifdef FAST_IPSEC 117 #include <netipsec/ipsec.h> 118 #include <netipsec/ipsec6.h> 119 #define IPSEC 120 #endif /* FAST_IPSEC */ 121 122 #include <netinet6/ip6_fw.h> 123 124 #include <netinet6/ip6protosw.h> 125 126 #include <net/net_osdep.h> 127 128 extern struct domain inet6domain; 129 130 u_char ip6_protox[IPPROTO_MAX]; 131 static struct ifqueue ip6intrq; 132 static int ip6qmaxlen = IFQ_MAXLEN; 133 struct in6_ifaddr *in6_ifaddr; 134 135 extern struct callout in6_tmpaddrtimer_ch; 136 137 int ip6_forward_srcrt; /* XXX */ 138 int ip6_sourcecheck; /* XXX */ 139 int ip6_sourcecheck_interval; /* XXX */ 140 141 int ip6_ours_check_algorithm; 142 143 #ifdef PFIL_HOOKS 144 struct pfil_head inet6_pfil_hook; 145 #endif 146 147 /* firewall hooks */ 148 ip6_fw_chk_t *ip6_fw_chk_ptr; 149 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 150 int ip6_fw_enable = 1; 151 152 struct ip6stat ip6stat; 153 154 static void ip6_init2 __P((void *)); 155 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 156 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 157 #ifdef PULLDOWN_TEST 158 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 159 #endif 160 161 /* 162 * IP6 initialization: fill in IP6 protocol switch table. 163 * All protocols not implemented in kernel go to raw IP6 protocol handler. 164 */ 165 void 166 ip6_init() 167 { 168 struct ip6protosw *pr; 169 int i; 170 171 #ifdef DIAGNOSTIC 172 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 173 panic("sizeof(protosw) != sizeof(ip6protosw)"); 174 #endif 175 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 176 if (pr == 0) 177 panic("ip6_init"); 178 for (i = 0; i < IPPROTO_MAX; i++) 179 ip6_protox[i] = pr - inet6sw; 180 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 181 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 182 if (pr->pr_domain->dom_family == PF_INET6 && 183 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 184 ip6_protox[pr->pr_protocol] = pr - inet6sw; 185 #ifdef PFIL_HOOKS 186 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 187 inet6_pfil_hook.ph_af = AF_INET6; 188 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 189 printf("%s: WARNING: unable to register pfil hook, " 190 "error %d\n", __func__, i); 191 #endif /* PFIL_HOOKS */ 192 ip6intrq.ifq_maxlen = ip6qmaxlen; 193 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 194 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 195 scope6_init(); 196 addrsel_policy_init(); 197 nd6_init(); 198 frag6_init(); 199 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 200 } 201 202 static void 203 ip6_init2(dummy) 204 void *dummy; 205 { 206 207 /* nd6_timer_init */ 208 callout_init(&nd6_timer_ch, 0); 209 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 210 211 /* router renumbering prefix list maintenance */ 212 callout_init(&in6_rr_timer_ch, 0); 213 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 214 215 /* timer for regeneranation of temporary addresses randomize ID */ 216 callout_init(&in6_tmpaddrtimer_ch, 0); 217 callout_reset(&in6_tmpaddrtimer_ch, 218 (ip6_temp_preferred_lifetime - ip6_desync_factor - 219 ip6_temp_regen_advance) * hz, 220 in6_tmpaddrtimer, NULL); 221 } 222 223 /* cheat */ 224 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 225 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 226 227 extern struct route_in6 ip6_forward_rt; 228 229 void 230 ip6_input(m) 231 struct mbuf *m; 232 { 233 struct ip6_hdr *ip6; 234 int off = sizeof(struct ip6_hdr), nest; 235 u_int32_t plen; 236 u_int32_t rtalert = ~0; 237 int nxt, ours = 0; 238 struct ifnet *deliverifp = NULL; 239 struct sockaddr_in6 sa6; 240 u_int32_t srczone, dstzone; 241 #ifdef PFIL_HOOKS 242 struct in6_addr odst; 243 #endif 244 int srcrt = 0; 245 246 GIANT_REQUIRED; /* XXX for now */ 247 #ifdef IPSEC 248 /* 249 * should the inner packet be considered authentic? 250 * see comment in ah4_input(). 251 */ 252 if (m) { 253 m->m_flags &= ~M_AUTHIPHDR; 254 m->m_flags &= ~M_AUTHIPDGM; 255 } 256 #endif 257 258 /* 259 * make sure we don't have onion peering information into m_tag. 260 */ 261 ip6_delaux(m); 262 263 /* 264 * mbuf statistics 265 */ 266 if (m->m_flags & M_EXT) { 267 if (m->m_next) 268 ip6stat.ip6s_mext2m++; 269 else 270 ip6stat.ip6s_mext1++; 271 } else { 272 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 273 if (m->m_next) { 274 if (m->m_flags & M_LOOP) { 275 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 276 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 277 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 278 else 279 ip6stat.ip6s_m2m[0]++; 280 } else 281 ip6stat.ip6s_m1++; 282 #undef M2MMAX 283 } 284 285 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 286 ip6stat.ip6s_total++; 287 288 #ifndef PULLDOWN_TEST 289 /* 290 * L2 bridge code and some other code can return mbuf chain 291 * that does not conform to KAME requirement. too bad. 292 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 293 */ 294 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 295 struct mbuf *n; 296 297 MGETHDR(n, M_DONTWAIT, MT_HEADER); 298 if (n) 299 M_MOVE_PKTHDR(n, m); 300 if (n && n->m_pkthdr.len > MHLEN) { 301 MCLGET(n, M_DONTWAIT); 302 if ((n->m_flags & M_EXT) == 0) { 303 m_freem(n); 304 n = NULL; 305 } 306 } 307 if (n == NULL) { 308 m_freem(m); 309 return; /* ENOBUFS */ 310 } 311 312 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 313 n->m_len = n->m_pkthdr.len; 314 m_freem(m); 315 m = n; 316 } 317 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 318 #endif 319 320 if (m->m_len < sizeof(struct ip6_hdr)) { 321 struct ifnet *inifp; 322 inifp = m->m_pkthdr.rcvif; 323 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 324 ip6stat.ip6s_toosmall++; 325 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 326 return; 327 } 328 } 329 330 ip6 = mtod(m, struct ip6_hdr *); 331 332 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 333 ip6stat.ip6s_badvers++; 334 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 335 goto bad; 336 } 337 338 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 339 340 /* 341 * Check against address spoofing/corruption. 342 */ 343 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 344 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 345 /* 346 * XXX: "badscope" is not very suitable for a multicast source. 347 */ 348 ip6stat.ip6s_badscope++; 349 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 350 goto bad; 351 } 352 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 353 !(m->m_flags & M_LOOP)) { 354 /* 355 * In this case, the packet should come from the loopback 356 * interface. However, we cannot just check the if_flags, 357 * because ip6_mloopback() passes the "actual" interface 358 * as the outgoing/incoming interface. 359 */ 360 ip6stat.ip6s_badscope++; 361 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 362 goto bad; 363 } 364 365 #ifdef ALTQ 366 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 367 /* packet is dropped by traffic conditioner */ 368 return; 369 } 370 #endif 371 /* 372 * The following check is not documented in specs. A malicious 373 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 374 * and bypass security checks (act as if it was from 127.0.0.1 by using 375 * IPv6 src ::ffff:127.0.0.1). Be cautious. 376 * 377 * This check chokes if we are in an SIIT cloud. As none of BSDs 378 * support IPv4-less kernel compilation, we cannot support SIIT 379 * environment at all. So, it makes more sense for us to reject any 380 * malicious packets for non-SIIT environment, than try to do a 381 * partial support for SIIT environment. 382 */ 383 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 384 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 385 ip6stat.ip6s_badscope++; 386 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 387 goto bad; 388 } 389 #if 0 390 /* 391 * Reject packets with IPv4 compatible addresses (auto tunnel). 392 * 393 * The code forbids auto tunnel relay case in RFC1933 (the check is 394 * stronger than RFC1933). We may want to re-enable it if mech-xx 395 * is revised to forbid relaying case. 396 */ 397 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 398 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 399 ip6stat.ip6s_badscope++; 400 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 401 goto bad; 402 } 403 #endif 404 405 /* 406 * Drop packets if the link ID portion is already filled. 407 * XXX: this is technically not a good behavior. But, we internally 408 * use the field to disambiguate link-local addresses, so we cannot 409 * be generous against those a bit strange addresses. 410 */ 411 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 412 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 413 ip6->ip6_src.s6_addr16[1]) { 414 ip6stat.ip6s_badscope++; 415 goto bad; 416 } 417 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 418 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 419 ip6->ip6_dst.s6_addr16[1]) { 420 ip6stat.ip6s_badscope++; 421 goto bad; 422 } 423 } 424 425 #ifdef PFIL_HOOKS 426 /* 427 * Run through list of hooks for input packets. 428 * 429 * NB: Beware of the destination address changing 430 * (e.g. by NAT rewriting). When this happens, 431 * tell ip6_forward to do the right thing. 432 */ 433 odst = ip6->ip6_dst; 434 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 435 return; 436 if (m == NULL) /* consumed by filter */ 437 return; 438 ip6 = mtod(m, struct ip6_hdr *); 439 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 440 #endif /* PFIL_HOOKS */ 441 442 /* 443 * Check with the firewall... 444 */ 445 if (ip6_fw_enable && ip6_fw_chk_ptr) { 446 u_short port = 0; 447 /* If ipfw says divert, we have to just drop packet */ 448 /* use port as a dummy argument */ 449 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 450 m_freem(m); 451 m = NULL; 452 } 453 if (!m) 454 return; 455 } 456 457 /* 458 * construct source and destination address structures with 459 * disambiguating their scope zones (if there is ambiguity). 460 * XXX: sin6_family and sin6_len will NOT be referred to, but we fill 461 * in these fields just in case. 462 */ 463 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_src, &srczone) || 464 in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst, &dstzone)) { 465 /* 466 * Note that these generic checks cover cases that src or 467 * dst are the loopback address and the receiving interface 468 * is not loopback. 469 */ 470 ip6stat.ip6s_badscope++; 471 goto bad; 472 } 473 474 bzero(&sa6, sizeof(sa6)); 475 sa6.sin6_family = AF_INET6; 476 sa6.sin6_len = sizeof(struct sockaddr_in6); 477 478 sa6.sin6_addr = ip6->ip6_src; 479 sa6.sin6_scope_id = srczone; 480 if (in6_embedscope(&ip6->ip6_src, &sa6, NULL, NULL)) { 481 /* XXX: should not happen */ 482 ip6stat.ip6s_badscope++; 483 goto bad; 484 } 485 486 sa6.sin6_addr = ip6->ip6_dst; 487 sa6.sin6_scope_id = dstzone; 488 if (in6_embedscope(&ip6->ip6_dst, &sa6, NULL, NULL)) { 489 /* XXX: should not happen */ 490 ip6stat.ip6s_badscope++; 491 goto bad; 492 } 493 494 /* XXX: ff01::%ifN awareness is not merged, yet. */ 495 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_src)) 496 ip6->ip6_src.s6_addr16[1] = 0; 497 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) 498 ip6->ip6_dst.s6_addr16[1] = 0; 499 500 /* 501 * Multicast check 502 */ 503 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 504 struct in6_multi *in6m = 0; 505 506 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 507 /* 508 * See if we belong to the destination multicast group on the 509 * arrival interface. 510 */ 511 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 512 if (in6m) 513 ours = 1; 514 else if (!ip6_mrouter) { 515 ip6stat.ip6s_notmember++; 516 ip6stat.ip6s_cantforward++; 517 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 518 goto bad; 519 } 520 deliverifp = m->m_pkthdr.rcvif; 521 goto hbhcheck; 522 } 523 524 /* 525 * Unicast check 526 */ 527 if (ip6_forward_rt.ro_rt != NULL && 528 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 529 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 530 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 531 ip6stat.ip6s_forward_cachehit++; 532 else { 533 struct sockaddr_in6 *dst6; 534 535 if (ip6_forward_rt.ro_rt) { 536 /* route is down or destination is different */ 537 ip6stat.ip6s_forward_cachemiss++; 538 RTFREE(ip6_forward_rt.ro_rt); 539 ip6_forward_rt.ro_rt = 0; 540 } 541 542 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 543 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 544 dst6->sin6_len = sizeof(struct sockaddr_in6); 545 dst6->sin6_family = AF_INET6; 546 dst6->sin6_addr = ip6->ip6_dst; 547 548 rtalloc((struct route *)&ip6_forward_rt); 549 } 550 551 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 552 553 /* 554 * Accept the packet if the forwarding interface to the destination 555 * according to the routing table is the loopback interface, 556 * unless the associated route has a gateway. 557 * Note that this approach causes to accept a packet if there is a 558 * route to the loopback interface for the destination of the packet. 559 * But we think it's even useful in some situations, e.g. when using 560 * a special daemon which wants to intercept the packet. 561 * 562 * XXX: some OSes automatically make a cloned route for the destination 563 * of an outgoing packet. If the outgoing interface of the packet 564 * is a loopback one, the kernel would consider the packet to be 565 * accepted, even if we have no such address assinged on the interface. 566 * We check the cloned flag of the route entry to reject such cases, 567 * assuming that route entries for our own addresses are not made by 568 * cloning (it should be true because in6_addloop explicitly installs 569 * the host route). However, we might have to do an explicit check 570 * while it would be less efficient. Or, should we rather install a 571 * reject route for such a case? 572 */ 573 if (ip6_forward_rt.ro_rt && 574 (ip6_forward_rt.ro_rt->rt_flags & 575 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 576 #ifdef RTF_WASCLONED 577 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 578 #endif 579 #ifdef RTF_CLONED 580 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 581 #endif 582 #if 0 583 /* 584 * The check below is redundant since the comparison of 585 * the destination and the key of the rtentry has 586 * already done through looking up the routing table. 587 */ 588 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 589 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 590 #endif 591 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 592 struct in6_ifaddr *ia6 = 593 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 594 595 /* 596 * record address information into m_tag. 597 */ 598 (void)ip6_setdstifaddr(m, ia6); 599 600 /* 601 * packets to a tentative, duplicated, or somehow invalid 602 * address must not be accepted. 603 */ 604 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 605 /* this address is ready */ 606 ours = 1; 607 deliverifp = ia6->ia_ifp; /* correct? */ 608 /* Count the packet in the ip address stats */ 609 ia6->ia_ifa.if_ipackets++; 610 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 611 goto hbhcheck; 612 } else { 613 /* address is not ready, so discard the packet. */ 614 nd6log((LOG_INFO, 615 "ip6_input: packet to an unready address %s->%s\n", 616 ip6_sprintf(&ip6->ip6_src), 617 ip6_sprintf(&ip6->ip6_dst))); 618 619 goto bad; 620 } 621 } 622 623 /* 624 * FAITH (Firewall Aided Internet Translator) 625 */ 626 if (ip6_keepfaith) { 627 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 628 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 629 /* XXX do we need more sanity checks? */ 630 ours = 1; 631 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 632 goto hbhcheck; 633 } 634 } 635 636 /* 637 * Now there is no reason to process the packet if it's not our own 638 * and we're not a router. 639 */ 640 if (!ip6_forwarding) { 641 ip6stat.ip6s_cantforward++; 642 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 643 goto bad; 644 } 645 646 hbhcheck: 647 /* 648 * record address information into m_tag, if we don't have one yet. 649 * note that we are unable to record it, if the address is not listed 650 * as our interface address (e.g. multicast addresses, addresses 651 * within FAITH prefixes and such). 652 */ 653 if (deliverifp && !ip6_getdstifaddr(m)) { 654 struct in6_ifaddr *ia6; 655 656 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 657 if (ia6) { 658 if (!ip6_setdstifaddr(m, ia6)) { 659 /* 660 * XXX maybe we should drop the packet here, 661 * as we could not provide enough information 662 * to the upper layers. 663 */ 664 } 665 } 666 } 667 668 /* 669 * Process Hop-by-Hop options header if it's contained. 670 * m may be modified in ip6_hopopts_input(). 671 * If a JumboPayload option is included, plen will also be modified. 672 */ 673 plen = (u_int32_t)ntohs(ip6->ip6_plen); 674 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 675 struct ip6_hbh *hbh; 676 677 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 678 #if 0 /*touches NULL pointer*/ 679 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 680 #endif 681 return; /* m have already been freed */ 682 } 683 684 /* adjust pointer */ 685 ip6 = mtod(m, struct ip6_hdr *); 686 687 /* 688 * if the payload length field is 0 and the next header field 689 * indicates Hop-by-Hop Options header, then a Jumbo Payload 690 * option MUST be included. 691 */ 692 if (ip6->ip6_plen == 0 && plen == 0) { 693 /* 694 * Note that if a valid jumbo payload option is 695 * contained, ip6_hopopts_input() must set a valid 696 * (non-zero) payload length to the variable plen. 697 */ 698 ip6stat.ip6s_badoptions++; 699 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 700 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 701 icmp6_error(m, ICMP6_PARAM_PROB, 702 ICMP6_PARAMPROB_HEADER, 703 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 704 return; 705 } 706 #ifndef PULLDOWN_TEST 707 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 708 hbh = (struct ip6_hbh *)(ip6 + 1); 709 #else 710 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 711 sizeof(struct ip6_hbh)); 712 if (hbh == NULL) { 713 ip6stat.ip6s_tooshort++; 714 return; 715 } 716 #endif 717 nxt = hbh->ip6h_nxt; 718 719 /* 720 * accept the packet if a router alert option is included 721 * and we act as an IPv6 router. 722 */ 723 if (rtalert != ~0 && ip6_forwarding) 724 ours = 1; 725 } else 726 nxt = ip6->ip6_nxt; 727 728 /* 729 * Check that the amount of data in the buffers 730 * is as at least much as the IPv6 header would have us expect. 731 * Trim mbufs if longer than we expect. 732 * Drop packet if shorter than we expect. 733 */ 734 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 735 ip6stat.ip6s_tooshort++; 736 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 737 goto bad; 738 } 739 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 740 if (m->m_len == m->m_pkthdr.len) { 741 m->m_len = sizeof(struct ip6_hdr) + plen; 742 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 743 } else 744 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 745 } 746 747 /* 748 * Forward if desirable. 749 */ 750 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 751 /* 752 * If we are acting as a multicast router, all 753 * incoming multicast packets are passed to the 754 * kernel-level multicast forwarding function. 755 * The packet is returned (relatively) intact; if 756 * ip6_mforward() returns a non-zero value, the packet 757 * must be discarded, else it may be accepted below. 758 */ 759 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 760 ip6stat.ip6s_cantforward++; 761 m_freem(m); 762 return; 763 } 764 if (!ours) { 765 m_freem(m); 766 return; 767 } 768 } else if (!ours) { 769 ip6_forward(m, srcrt); 770 return; 771 } 772 773 ip6 = mtod(m, struct ip6_hdr *); 774 775 /* 776 * Malicious party may be able to use IPv4 mapped addr to confuse 777 * tcp/udp stack and bypass security checks (act as if it was from 778 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 779 * 780 * For SIIT end node behavior, you may want to disable the check. 781 * However, you will become vulnerable to attacks using IPv4 mapped 782 * source. 783 */ 784 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 785 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 786 ip6stat.ip6s_badscope++; 787 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 788 goto bad; 789 } 790 791 /* 792 * Tell launch routine the next header 793 */ 794 ip6stat.ip6s_delivered++; 795 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 796 nest = 0; 797 798 while (nxt != IPPROTO_DONE) { 799 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 800 ip6stat.ip6s_toomanyhdr++; 801 goto bad; 802 } 803 804 /* 805 * protection against faulty packet - there should be 806 * more sanity checks in header chain processing. 807 */ 808 if (m->m_pkthdr.len < off) { 809 ip6stat.ip6s_tooshort++; 810 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 811 goto bad; 812 } 813 814 #ifdef IPSEC 815 /* 816 * enforce IPsec policy checking if we are seeing last header. 817 * note that we do not visit this with protocols with pcb layer 818 * code - like udp/tcp/raw ip. 819 */ 820 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 821 ipsec6_in_reject(m, NULL)) { 822 ipsec6stat.in_polvio++; 823 goto bad; 824 } 825 #endif 826 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 827 } 828 return; 829 bad: 830 m_freem(m); 831 } 832 833 /* 834 * set/grab in6_ifaddr correspond to IPv6 destination address. 835 * XXX backward compatibility wrapper 836 */ 837 static struct ip6aux * 838 ip6_setdstifaddr(m, ia6) 839 struct mbuf *m; 840 struct in6_ifaddr *ia6; 841 { 842 struct ip6aux *ip6a; 843 844 ip6a = ip6_addaux(m); 845 if (ip6a) 846 ip6a->ip6a_dstia6 = ia6; 847 return ip6a; /* NULL if failed to set */ 848 } 849 850 struct in6_ifaddr * 851 ip6_getdstifaddr(m) 852 struct mbuf *m; 853 { 854 struct ip6aux *ip6a; 855 856 ip6a = ip6_findaux(m); 857 if (ip6a) 858 return ip6a->ip6a_dstia6; 859 else 860 return NULL; 861 } 862 863 /* 864 * Hop-by-Hop options header processing. If a valid jumbo payload option is 865 * included, the real payload length will be stored in plenp. 866 */ 867 static int 868 ip6_hopopts_input(plenp, rtalertp, mp, offp) 869 u_int32_t *plenp; 870 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 871 struct mbuf **mp; 872 int *offp; 873 { 874 struct mbuf *m = *mp; 875 int off = *offp, hbhlen; 876 struct ip6_hbh *hbh; 877 u_int8_t *opt; 878 879 /* validation of the length of the header */ 880 #ifndef PULLDOWN_TEST 881 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 882 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 883 hbhlen = (hbh->ip6h_len + 1) << 3; 884 885 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 886 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 887 #else 888 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 889 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 890 if (hbh == NULL) { 891 ip6stat.ip6s_tooshort++; 892 return -1; 893 } 894 hbhlen = (hbh->ip6h_len + 1) << 3; 895 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 896 hbhlen); 897 if (hbh == NULL) { 898 ip6stat.ip6s_tooshort++; 899 return -1; 900 } 901 #endif 902 off += hbhlen; 903 hbhlen -= sizeof(struct ip6_hbh); 904 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 905 906 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 907 hbhlen, rtalertp, plenp) < 0) 908 return (-1); 909 910 *offp = off; 911 *mp = m; 912 return (0); 913 } 914 915 /* 916 * Search header for all Hop-by-hop options and process each option. 917 * This function is separate from ip6_hopopts_input() in order to 918 * handle a case where the sending node itself process its hop-by-hop 919 * options header. In such a case, the function is called from ip6_output(). 920 * 921 * The function assumes that hbh header is located right after the IPv6 header 922 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 923 * opthead + hbhlen is located in continuous memory region. 924 */ 925 int 926 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 927 struct mbuf *m; 928 u_int8_t *opthead; 929 int hbhlen; 930 u_int32_t *rtalertp; 931 u_int32_t *plenp; 932 { 933 struct ip6_hdr *ip6; 934 int optlen = 0; 935 u_int8_t *opt = opthead; 936 u_int16_t rtalert_val; 937 u_int32_t jumboplen; 938 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 939 940 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 941 switch (*opt) { 942 case IP6OPT_PAD1: 943 optlen = 1; 944 break; 945 case IP6OPT_PADN: 946 if (hbhlen < IP6OPT_MINLEN) { 947 ip6stat.ip6s_toosmall++; 948 goto bad; 949 } 950 optlen = *(opt + 1) + 2; 951 break; 952 case IP6OPT_ROUTER_ALERT: 953 /* XXX may need check for alignment */ 954 if (hbhlen < IP6OPT_RTALERT_LEN) { 955 ip6stat.ip6s_toosmall++; 956 goto bad; 957 } 958 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 959 /* XXX stat */ 960 icmp6_error(m, ICMP6_PARAM_PROB, 961 ICMP6_PARAMPROB_HEADER, 962 erroff + opt + 1 - opthead); 963 return (-1); 964 } 965 optlen = IP6OPT_RTALERT_LEN; 966 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 967 *rtalertp = ntohs(rtalert_val); 968 break; 969 case IP6OPT_JUMBO: 970 /* XXX may need check for alignment */ 971 if (hbhlen < IP6OPT_JUMBO_LEN) { 972 ip6stat.ip6s_toosmall++; 973 goto bad; 974 } 975 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 976 /* XXX stat */ 977 icmp6_error(m, ICMP6_PARAM_PROB, 978 ICMP6_PARAMPROB_HEADER, 979 erroff + opt + 1 - opthead); 980 return (-1); 981 } 982 optlen = IP6OPT_JUMBO_LEN; 983 984 /* 985 * IPv6 packets that have non 0 payload length 986 * must not contain a jumbo payload option. 987 */ 988 ip6 = mtod(m, struct ip6_hdr *); 989 if (ip6->ip6_plen) { 990 ip6stat.ip6s_badoptions++; 991 icmp6_error(m, ICMP6_PARAM_PROB, 992 ICMP6_PARAMPROB_HEADER, 993 erroff + opt - opthead); 994 return (-1); 995 } 996 997 /* 998 * We may see jumbolen in unaligned location, so 999 * we'd need to perform bcopy(). 1000 */ 1001 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1002 jumboplen = (u_int32_t)htonl(jumboplen); 1003 1004 #if 1 1005 /* 1006 * if there are multiple jumbo payload options, 1007 * *plenp will be non-zero and the packet will be 1008 * rejected. 1009 * the behavior may need some debate in ipngwg - 1010 * multiple options does not make sense, however, 1011 * there's no explicit mention in specification. 1012 */ 1013 if (*plenp != 0) { 1014 ip6stat.ip6s_badoptions++; 1015 icmp6_error(m, ICMP6_PARAM_PROB, 1016 ICMP6_PARAMPROB_HEADER, 1017 erroff + opt + 2 - opthead); 1018 return (-1); 1019 } 1020 #endif 1021 1022 /* 1023 * jumbo payload length must be larger than 65535. 1024 */ 1025 if (jumboplen <= IPV6_MAXPACKET) { 1026 ip6stat.ip6s_badoptions++; 1027 icmp6_error(m, ICMP6_PARAM_PROB, 1028 ICMP6_PARAMPROB_HEADER, 1029 erroff + opt + 2 - opthead); 1030 return (-1); 1031 } 1032 *plenp = jumboplen; 1033 1034 break; 1035 default: /* unknown option */ 1036 if (hbhlen < IP6OPT_MINLEN) { 1037 ip6stat.ip6s_toosmall++; 1038 goto bad; 1039 } 1040 optlen = ip6_unknown_opt(opt, m, 1041 erroff + opt - opthead); 1042 if (optlen == -1) 1043 return (-1); 1044 optlen += 2; 1045 break; 1046 } 1047 } 1048 1049 return (0); 1050 1051 bad: 1052 m_freem(m); 1053 return (-1); 1054 } 1055 1056 /* 1057 * Unknown option processing. 1058 * The third argument `off' is the offset from the IPv6 header to the option, 1059 * which is necessary if the IPv6 header the and option header and IPv6 header 1060 * is not continuous in order to return an ICMPv6 error. 1061 */ 1062 int 1063 ip6_unknown_opt(optp, m, off) 1064 u_int8_t *optp; 1065 struct mbuf *m; 1066 int off; 1067 { 1068 struct ip6_hdr *ip6; 1069 1070 switch (IP6OPT_TYPE(*optp)) { 1071 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1072 return ((int)*(optp + 1)); 1073 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1074 m_freem(m); 1075 return (-1); 1076 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1077 ip6stat.ip6s_badoptions++; 1078 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1079 return (-1); 1080 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1081 ip6stat.ip6s_badoptions++; 1082 ip6 = mtod(m, struct ip6_hdr *); 1083 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1084 (m->m_flags & (M_BCAST|M_MCAST))) 1085 m_freem(m); 1086 else 1087 icmp6_error(m, ICMP6_PARAM_PROB, 1088 ICMP6_PARAMPROB_OPTION, off); 1089 return (-1); 1090 } 1091 1092 m_freem(m); /* XXX: NOTREACHED */ 1093 return (-1); 1094 } 1095 1096 /* 1097 * Create the "control" list for this pcb. 1098 * The function will not modify mbuf chain at all. 1099 * 1100 * with KAME mbuf chain restriction: 1101 * The routine will be called from upper layer handlers like tcp6_input(). 1102 * Thus the routine assumes that the caller (tcp6_input) have already 1103 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1104 * very first mbuf on the mbuf chain. 1105 */ 1106 void 1107 ip6_savecontrol(in6p, m, mp) 1108 struct inpcb *in6p; 1109 struct mbuf *m, **mp; 1110 { 1111 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1112 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1113 1114 #ifdef SO_TIMESTAMP 1115 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1116 struct timeval tv; 1117 1118 microtime(&tv); 1119 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1120 SCM_TIMESTAMP, SOL_SOCKET); 1121 if (*mp) 1122 mp = &(*mp)->m_next; 1123 } 1124 #endif 1125 1126 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1127 return; 1128 1129 /* RFC 2292 sec. 5 */ 1130 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1131 struct in6_pktinfo pi6; 1132 1133 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1134 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1135 pi6.ipi6_ifindex = 1136 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1137 1138 *mp = sbcreatecontrol((caddr_t) &pi6, 1139 sizeof(struct in6_pktinfo), 1140 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1141 if (*mp) 1142 mp = &(*mp)->m_next; 1143 } 1144 1145 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1146 int hlim = ip6->ip6_hlim & 0xff; 1147 1148 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1149 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1150 if (*mp) 1151 mp = &(*mp)->m_next; 1152 } 1153 1154 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1155 u_int32_t flowinfo; 1156 int tclass; 1157 1158 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1159 flowinfo >>= 20; 1160 1161 tclass = flowinfo & 0xff; 1162 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1163 IPV6_TCLASS, IPPROTO_IPV6); 1164 if (*mp) 1165 mp = &(*mp)->m_next; 1166 } 1167 1168 /* 1169 * IPV6_HOPOPTS socket option. Recall that we required super-user 1170 * privilege for the option (see ip6_ctloutput), but it might be too 1171 * strict, since there might be some hop-by-hop options which can be 1172 * returned to normal user. 1173 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1174 */ 1175 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1176 /* 1177 * Check if a hop-by-hop options header is contatined in the 1178 * received packet, and if so, store the options as ancillary 1179 * data. Note that a hop-by-hop options header must be 1180 * just after the IPv6 header, which is assured through the 1181 * IPv6 input processing. 1182 */ 1183 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1184 struct ip6_hbh *hbh; 1185 int hbhlen = 0; 1186 #ifdef PULLDOWN_TEST 1187 struct mbuf *ext; 1188 #endif 1189 1190 #ifndef PULLDOWN_TEST 1191 hbh = (struct ip6_hbh *)(ip6 + 1); 1192 hbhlen = (hbh->ip6h_len + 1) << 3; 1193 #else 1194 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1195 ip6->ip6_nxt); 1196 if (ext == NULL) { 1197 ip6stat.ip6s_tooshort++; 1198 return; 1199 } 1200 hbh = mtod(ext, struct ip6_hbh *); 1201 hbhlen = (hbh->ip6h_len + 1) << 3; 1202 if (hbhlen != ext->m_len) { 1203 m_freem(ext); 1204 ip6stat.ip6s_tooshort++; 1205 return; 1206 } 1207 #endif 1208 1209 /* 1210 * XXX: We copy the whole header even if a 1211 * jumbo payload option is included, the option which 1212 * is to be removed before returning according to 1213 * RFC2292. 1214 * Note: this constraint is removed in 2292bis. 1215 */ 1216 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1217 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1218 IPPROTO_IPV6); 1219 if (*mp) 1220 mp = &(*mp)->m_next; 1221 #ifdef PULLDOWN_TEST 1222 m_freem(ext); 1223 #endif 1224 } 1225 } 1226 1227 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1228 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1229 1230 /* 1231 * Search for destination options headers or routing 1232 * header(s) through the header chain, and stores each 1233 * header as ancillary data. 1234 * Note that the order of the headers remains in 1235 * the chain of ancillary data. 1236 */ 1237 while (1) { /* is explicit loop prevention necessary? */ 1238 struct ip6_ext *ip6e = NULL; 1239 int elen; 1240 #ifdef PULLDOWN_TEST 1241 struct mbuf *ext = NULL; 1242 #endif 1243 1244 /* 1245 * if it is not an extension header, don't try to 1246 * pull it from the chain. 1247 */ 1248 switch (nxt) { 1249 case IPPROTO_DSTOPTS: 1250 case IPPROTO_ROUTING: 1251 case IPPROTO_HOPOPTS: 1252 case IPPROTO_AH: /* is it possible? */ 1253 break; 1254 default: 1255 goto loopend; 1256 } 1257 1258 #ifndef PULLDOWN_TEST 1259 if (off + sizeof(*ip6e) > m->m_len) 1260 goto loopend; 1261 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1262 if (nxt == IPPROTO_AH) 1263 elen = (ip6e->ip6e_len + 2) << 2; 1264 else 1265 elen = (ip6e->ip6e_len + 1) << 3; 1266 if (off + elen > m->m_len) 1267 goto loopend; 1268 #else 1269 ext = ip6_pullexthdr(m, off, nxt); 1270 if (ext == NULL) { 1271 ip6stat.ip6s_tooshort++; 1272 return; 1273 } 1274 ip6e = mtod(ext, struct ip6_ext *); 1275 if (nxt == IPPROTO_AH) 1276 elen = (ip6e->ip6e_len + 2) << 2; 1277 else 1278 elen = (ip6e->ip6e_len + 1) << 3; 1279 if (elen != ext->m_len) { 1280 m_freem(ext); 1281 ip6stat.ip6s_tooshort++; 1282 return; 1283 } 1284 #endif 1285 1286 switch (nxt) { 1287 case IPPROTO_DSTOPTS: 1288 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1289 break; 1290 1291 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1292 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1293 IPPROTO_IPV6); 1294 if (*mp) 1295 mp = &(*mp)->m_next; 1296 break; 1297 case IPPROTO_ROUTING: 1298 if (!in6p->in6p_flags & IN6P_RTHDR) 1299 break; 1300 1301 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1302 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1303 IPPROTO_IPV6); 1304 if (*mp) 1305 mp = &(*mp)->m_next; 1306 break; 1307 case IPPROTO_HOPOPTS: 1308 case IPPROTO_AH: /* is it possible? */ 1309 break; 1310 1311 default: 1312 /* 1313 * other cases have been filtered in the above. 1314 * none will visit this case. here we supply 1315 * the code just in case (nxt overwritten or 1316 * other cases). 1317 */ 1318 #ifdef PULLDOWN_TEST 1319 m_freem(ext); 1320 #endif 1321 goto loopend; 1322 1323 } 1324 1325 /* proceed with the next header. */ 1326 off += elen; 1327 nxt = ip6e->ip6e_nxt; 1328 ip6e = NULL; 1329 #ifdef PULLDOWN_TEST 1330 m_freem(ext); 1331 ext = NULL; 1332 #endif 1333 } 1334 loopend: 1335 ; 1336 } 1337 1338 #undef IS2292 1339 } 1340 1341 void 1342 ip6_notify_pmtu(in6p, dst, mtu) 1343 struct inpcb *in6p; 1344 struct sockaddr_in6 *dst; 1345 u_int32_t *mtu; 1346 { 1347 struct socket *so; 1348 struct mbuf *m_mtu; 1349 struct ip6_mtuinfo mtuctl; 1350 1351 so = in6p->inp_socket; 1352 1353 if (mtu == NULL) 1354 return; 1355 1356 #ifdef DIAGNOSTIC 1357 if (so == NULL) /* I believe this is impossible */ 1358 panic("ip6_notify_pmtu: socket is NULL"); 1359 #endif 1360 1361 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1362 mtuctl.ip6m_mtu = *mtu; 1363 mtuctl.ip6m_addr = *dst; 1364 in6_recoverscope(&mtuctl.ip6m_addr, &mtuctl.ip6m_addr.sin6_addr, NULL); 1365 1366 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1367 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1368 return; 1369 1370 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1371 == 0) { 1372 m_freem(m_mtu); 1373 /* XXX: should count statistics */ 1374 } else 1375 sorwakeup(so); 1376 1377 return; 1378 } 1379 1380 #ifdef PULLDOWN_TEST 1381 /* 1382 * pull single extension header from mbuf chain. returns single mbuf that 1383 * contains the result, or NULL on error. 1384 */ 1385 static struct mbuf * 1386 ip6_pullexthdr(m, off, nxt) 1387 struct mbuf *m; 1388 size_t off; 1389 int nxt; 1390 { 1391 struct ip6_ext ip6e; 1392 size_t elen; 1393 struct mbuf *n; 1394 1395 #ifdef DIAGNOSTIC 1396 switch (nxt) { 1397 case IPPROTO_DSTOPTS: 1398 case IPPROTO_ROUTING: 1399 case IPPROTO_HOPOPTS: 1400 case IPPROTO_AH: /* is it possible? */ 1401 break; 1402 default: 1403 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1404 } 1405 #endif 1406 1407 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1408 if (nxt == IPPROTO_AH) 1409 elen = (ip6e.ip6e_len + 2) << 2; 1410 else 1411 elen = (ip6e.ip6e_len + 1) << 3; 1412 1413 MGET(n, M_DONTWAIT, MT_DATA); 1414 if (n && elen >= MLEN) { 1415 MCLGET(n, M_DONTWAIT); 1416 if ((n->m_flags & M_EXT) == 0) { 1417 m_free(n); 1418 n = NULL; 1419 } 1420 } 1421 if (!n) 1422 return NULL; 1423 1424 n->m_len = 0; 1425 if (elen >= M_TRAILINGSPACE(n)) { 1426 m_free(n); 1427 return NULL; 1428 } 1429 1430 m_copydata(m, off, elen, mtod(n, caddr_t)); 1431 n->m_len = elen; 1432 return n; 1433 } 1434 #endif 1435 1436 /* 1437 * Get pointer to the previous header followed by the header 1438 * currently processed. 1439 * XXX: This function supposes that 1440 * M includes all headers, 1441 * the next header field and the header length field of each header 1442 * are valid, and 1443 * the sum of each header length equals to OFF. 1444 * Because of these assumptions, this function must be called very 1445 * carefully. Moreover, it will not be used in the near future when 1446 * we develop `neater' mechanism to process extension headers. 1447 */ 1448 char * 1449 ip6_get_prevhdr(m, off) 1450 struct mbuf *m; 1451 int off; 1452 { 1453 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1454 1455 if (off == sizeof(struct ip6_hdr)) 1456 return (&ip6->ip6_nxt); 1457 else { 1458 int len, nxt; 1459 struct ip6_ext *ip6e = NULL; 1460 1461 nxt = ip6->ip6_nxt; 1462 len = sizeof(struct ip6_hdr); 1463 while (len < off) { 1464 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1465 1466 switch (nxt) { 1467 case IPPROTO_FRAGMENT: 1468 len += sizeof(struct ip6_frag); 1469 break; 1470 case IPPROTO_AH: 1471 len += (ip6e->ip6e_len + 2) << 2; 1472 break; 1473 default: 1474 len += (ip6e->ip6e_len + 1) << 3; 1475 break; 1476 } 1477 nxt = ip6e->ip6e_nxt; 1478 } 1479 if (ip6e) 1480 return (&ip6e->ip6e_nxt); 1481 else 1482 return NULL; 1483 } 1484 } 1485 1486 /* 1487 * get next header offset. m will be retained. 1488 */ 1489 int 1490 ip6_nexthdr(m, off, proto, nxtp) 1491 struct mbuf *m; 1492 int off; 1493 int proto; 1494 int *nxtp; 1495 { 1496 struct ip6_hdr ip6; 1497 struct ip6_ext ip6e; 1498 struct ip6_frag fh; 1499 1500 /* just in case */ 1501 if (m == NULL) 1502 panic("ip6_nexthdr: m == NULL"); 1503 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1504 return -1; 1505 1506 switch (proto) { 1507 case IPPROTO_IPV6: 1508 if (m->m_pkthdr.len < off + sizeof(ip6)) 1509 return -1; 1510 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1511 if (nxtp) 1512 *nxtp = ip6.ip6_nxt; 1513 off += sizeof(ip6); 1514 return off; 1515 1516 case IPPROTO_FRAGMENT: 1517 /* 1518 * terminate parsing if it is not the first fragment, 1519 * it does not make sense to parse through it. 1520 */ 1521 if (m->m_pkthdr.len < off + sizeof(fh)) 1522 return -1; 1523 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1524 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1525 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1526 return -1; 1527 if (nxtp) 1528 *nxtp = fh.ip6f_nxt; 1529 off += sizeof(struct ip6_frag); 1530 return off; 1531 1532 case IPPROTO_AH: 1533 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1534 return -1; 1535 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1536 if (nxtp) 1537 *nxtp = ip6e.ip6e_nxt; 1538 off += (ip6e.ip6e_len + 2) << 2; 1539 return off; 1540 1541 case IPPROTO_HOPOPTS: 1542 case IPPROTO_ROUTING: 1543 case IPPROTO_DSTOPTS: 1544 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1545 return -1; 1546 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1547 if (nxtp) 1548 *nxtp = ip6e.ip6e_nxt; 1549 off += (ip6e.ip6e_len + 1) << 3; 1550 return off; 1551 1552 case IPPROTO_NONE: 1553 case IPPROTO_ESP: 1554 case IPPROTO_IPCOMP: 1555 /* give up */ 1556 return -1; 1557 1558 default: 1559 return -1; 1560 } 1561 1562 return -1; 1563 } 1564 1565 /* 1566 * get offset for the last header in the chain. m will be kept untainted. 1567 */ 1568 int 1569 ip6_lasthdr(m, off, proto, nxtp) 1570 struct mbuf *m; 1571 int off; 1572 int proto; 1573 int *nxtp; 1574 { 1575 int newoff; 1576 int nxt; 1577 1578 if (!nxtp) { 1579 nxt = -1; 1580 nxtp = &nxt; 1581 } 1582 while (1) { 1583 newoff = ip6_nexthdr(m, off, proto, nxtp); 1584 if (newoff < 0) 1585 return off; 1586 else if (newoff < off) 1587 return -1; /* invalid */ 1588 else if (newoff == off) 1589 return newoff; 1590 1591 off = newoff; 1592 proto = *nxtp; 1593 } 1594 } 1595 1596 struct ip6aux * 1597 ip6_addaux(m) 1598 struct mbuf *m; 1599 { 1600 struct m_tag *mtag; 1601 1602 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1603 if (!mtag) { 1604 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1605 M_NOWAIT); 1606 if (mtag) { 1607 m_tag_prepend(m, mtag); 1608 bzero(mtag + 1, sizeof(struct ip6aux)); 1609 } 1610 } 1611 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1612 } 1613 1614 struct ip6aux * 1615 ip6_findaux(m) 1616 struct mbuf *m; 1617 { 1618 struct m_tag *mtag; 1619 1620 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1621 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1622 } 1623 1624 void 1625 ip6_delaux(m) 1626 struct mbuf *m; 1627 { 1628 struct m_tag *mtag; 1629 1630 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1631 if (mtag) 1632 m_tag_delete(m, mtag); 1633 } 1634 1635 /* 1636 * System control for IP6 1637 */ 1638 1639 u_char inet6ctlerrmap[PRC_NCMDS] = { 1640 0, 0, 0, 0, 1641 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1642 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1643 EMSGSIZE, EHOSTUNREACH, 0, 0, 1644 0, 0, 0, 0, 1645 ENOPROTOOPT 1646 }; 1647