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 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 66 */ 67 68 #include "opt_ip6fw.h" 69 #include "opt_inet.h" 70 #include "opt_inet6.h" 71 #include "opt_ipsec.h" 72 #include "opt_pfil_hooks.h" 73 #include "opt_random_ip_id.h" 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/malloc.h> 78 #include <sys/mbuf.h> 79 #include <sys/proc.h> 80 #include <sys/domain.h> 81 #include <sys/protosw.h> 82 #include <sys/socket.h> 83 #include <sys/socketvar.h> 84 #include <sys/errno.h> 85 #include <sys/time.h> 86 #include <sys/kernel.h> 87 #include <sys/syslog.h> 88 89 #include <net/if.h> 90 #include <net/if_types.h> 91 #include <net/if_dl.h> 92 #include <net/route.h> 93 #include <net/netisr.h> 94 #ifdef PFIL_HOOKS 95 #include <net/pfil.h> 96 #endif 97 98 #include <netinet/in.h> 99 #include <netinet/in_systm.h> 100 #ifdef INET 101 #include <netinet/ip.h> 102 #include <netinet/ip_icmp.h> 103 #endif /* INET */ 104 #include <netinet/ip6.h> 105 #include <netinet6/in6_var.h> 106 #include <netinet6/ip6_var.h> 107 #include <netinet/in_pcb.h> 108 #include <netinet/icmp6.h> 109 #include <netinet6/scope6_var.h> 110 #include <netinet6/in6_ifattach.h> 111 #include <netinet6/nd6.h> 112 #include <netinet6/in6_prefix.h> 113 114 #ifdef IPSEC 115 #include <netinet6/ipsec.h> 116 #ifdef INET6 117 #include <netinet6/ipsec6.h> 118 #endif 119 #endif 120 121 #ifdef FAST_IPSEC 122 #include <netipsec/ipsec.h> 123 #include <netipsec/ipsec6.h> 124 #define IPSEC 125 #endif /* FAST_IPSEC */ 126 127 #include <netinet6/ip6_fw.h> 128 129 #include <netinet6/ip6protosw.h> 130 131 #include <net/net_osdep.h> 132 133 extern struct domain inet6domain; 134 135 u_char ip6_protox[IPPROTO_MAX]; 136 static struct ifqueue ip6intrq; 137 static int ip6qmaxlen = IFQ_MAXLEN; 138 struct in6_ifaddr *in6_ifaddr; 139 140 extern struct callout in6_tmpaddrtimer_ch; 141 142 int ip6_forward_srcrt; /* XXX */ 143 int ip6_sourcecheck; /* XXX */ 144 int ip6_sourcecheck_interval; /* XXX */ 145 146 int ip6_ours_check_algorithm; 147 148 #ifdef PFIL_HOOKS 149 struct pfil_head inet6_pfil_hook; 150 #endif 151 152 /* firewall hooks */ 153 ip6_fw_chk_t *ip6_fw_chk_ptr; 154 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 155 int ip6_fw_enable = 1; 156 157 struct ip6stat ip6stat; 158 159 static void ip6_init2 __P((void *)); 160 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 161 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 162 #ifdef PULLDOWN_TEST 163 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 164 #endif 165 166 /* 167 * IP6 initialization: fill in IP6 protocol switch table. 168 * All protocols not implemented in kernel go to raw IP6 protocol handler. 169 */ 170 void 171 ip6_init() 172 { 173 struct ip6protosw *pr; 174 int i; 175 176 #ifdef DIAGNOSTIC 177 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 178 panic("sizeof(protosw) != sizeof(ip6protosw)"); 179 #endif 180 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 181 if (pr == 0) 182 panic("ip6_init"); 183 for (i = 0; i < IPPROTO_MAX; i++) 184 ip6_protox[i] = pr - inet6sw; 185 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 186 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 187 if (pr->pr_domain->dom_family == PF_INET6 && 188 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 189 ip6_protox[pr->pr_protocol] = pr - inet6sw; 190 #ifdef PFIL_HOOKS 191 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 192 inet6_pfil_hook.ph_af = AF_INET6; 193 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) 194 printf("%s: WARNING: unable to register pfil hook, " 195 "error %d\n", __func__, i); 196 #endif /* PFIL_HOOKS */ 197 ip6intrq.ifq_maxlen = ip6qmaxlen; 198 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 199 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0); 200 scope6_init(); 201 addrsel_policy_init(); 202 nd6_init(); 203 frag6_init(); 204 #ifndef RANDOM_IP_ID 205 ip6_flow_seq = arc4random(); 206 #endif 207 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 208 } 209 210 static void 211 ip6_init2(dummy) 212 void *dummy; 213 { 214 215 /* nd6_timer_init */ 216 callout_init(&nd6_timer_ch, 0); 217 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 218 219 /* router renumbering prefix list maintenance */ 220 callout_init(&in6_rr_timer_ch, 0); 221 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 222 223 /* timer for regeneranation of temporary addresses randomize ID */ 224 callout_init(&in6_tmpaddrtimer_ch, 0); 225 callout_reset(&in6_tmpaddrtimer_ch, 226 (ip6_temp_preferred_lifetime - ip6_desync_factor - 227 ip6_temp_regen_advance) * hz, 228 in6_tmpaddrtimer, NULL); 229 } 230 231 /* cheat */ 232 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 233 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 234 235 extern struct route_in6 ip6_forward_rt; 236 237 void 238 ip6_input(m) 239 struct mbuf *m; 240 { 241 struct ip6_hdr *ip6; 242 int off = sizeof(struct ip6_hdr), nest; 243 u_int32_t plen; 244 u_int32_t rtalert = ~0; 245 int nxt, ours = 0; 246 struct ifnet *deliverifp = NULL; 247 struct sockaddr_in6 sa6; 248 u_int32_t srczone, dstzone; 249 #ifdef PFIL_HOOKS 250 struct in6_addr odst; 251 #endif 252 int srcrt = 0; 253 254 GIANT_REQUIRED; /* XXX for now */ 255 #ifdef IPSEC 256 /* 257 * should the inner packet be considered authentic? 258 * see comment in ah4_input(). 259 */ 260 if (m) { 261 m->m_flags &= ~M_AUTHIPHDR; 262 m->m_flags &= ~M_AUTHIPDGM; 263 } 264 #endif 265 266 /* 267 * make sure we don't have onion peering information into m_tag. 268 */ 269 ip6_delaux(m); 270 271 /* 272 * mbuf statistics 273 */ 274 if (m->m_flags & M_EXT) { 275 if (m->m_next) 276 ip6stat.ip6s_mext2m++; 277 else 278 ip6stat.ip6s_mext1++; 279 } else { 280 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 281 if (m->m_next) { 282 if (m->m_flags & M_LOOP) { 283 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 284 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 285 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 286 else 287 ip6stat.ip6s_m2m[0]++; 288 } else 289 ip6stat.ip6s_m1++; 290 #undef M2MMAX 291 } 292 293 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 294 ip6stat.ip6s_total++; 295 296 #ifndef PULLDOWN_TEST 297 /* 298 * L2 bridge code and some other code can return mbuf chain 299 * that does not conform to KAME requirement. too bad. 300 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 301 */ 302 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 303 struct mbuf *n; 304 305 MGETHDR(n, M_DONTWAIT, MT_HEADER); 306 if (n) 307 M_MOVE_PKTHDR(n, m); 308 if (n && n->m_pkthdr.len > MHLEN) { 309 MCLGET(n, M_DONTWAIT); 310 if ((n->m_flags & M_EXT) == 0) { 311 m_freem(n); 312 n = NULL; 313 } 314 } 315 if (n == NULL) { 316 m_freem(m); 317 return; /* ENOBUFS */ 318 } 319 320 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 321 n->m_len = n->m_pkthdr.len; 322 m_freem(m); 323 m = n; 324 } 325 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 326 #endif 327 328 if (m->m_len < sizeof(struct ip6_hdr)) { 329 struct ifnet *inifp; 330 inifp = m->m_pkthdr.rcvif; 331 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 332 ip6stat.ip6s_toosmall++; 333 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 334 return; 335 } 336 } 337 338 ip6 = mtod(m, struct ip6_hdr *); 339 340 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 341 ip6stat.ip6s_badvers++; 342 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 343 goto bad; 344 } 345 346 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 347 348 /* 349 * Check against address spoofing/corruption. 350 */ 351 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 352 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 353 /* 354 * XXX: "badscope" is not very suitable for a multicast source. 355 */ 356 ip6stat.ip6s_badscope++; 357 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 358 goto bad; 359 } 360 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 361 !(m->m_flags & M_LOOP)) { 362 /* 363 * In this case, the packet should come from the loopback 364 * interface. However, we cannot just check the if_flags, 365 * because ip6_mloopback() passes the "actual" interface 366 * as the outgoing/incoming interface. 367 */ 368 ip6stat.ip6s_badscope++; 369 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 370 goto bad; 371 } 372 373 /* 374 * The following check is not documented in specs. A malicious 375 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 376 * and bypass security checks (act as if it was from 127.0.0.1 by using 377 * IPv6 src ::ffff:127.0.0.1). Be cautious. 378 * 379 * This check chokes if we are in an SIIT cloud. As none of BSDs 380 * support IPv4-less kernel compilation, we cannot support SIIT 381 * environment at all. So, it makes more sense for us to reject any 382 * malicious packets for non-SIIT environment, than try to do a 383 * partial support for SIIT environment. 384 */ 385 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 386 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 387 ip6stat.ip6s_badscope++; 388 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 389 goto bad; 390 } 391 #if 0 392 /* 393 * Reject packets with IPv4 compatible addresses (auto tunnel). 394 * 395 * The code forbids auto tunnel relay case in RFC1933 (the check is 396 * stronger than RFC1933). We may want to re-enable it if mech-xx 397 * is revised to forbid relaying case. 398 */ 399 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 400 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 401 ip6stat.ip6s_badscope++; 402 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 403 goto bad; 404 } 405 #endif 406 407 /* 408 * Drop packets if the link ID portion is already filled. 409 * XXX: this is technically not a good behavior. But, we internally 410 * use the field to disambiguate link-local addresses, so we cannot 411 * be generous against those a bit strange addresses. 412 */ 413 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 414 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 415 ip6->ip6_src.s6_addr16[1]) { 416 ip6stat.ip6s_badscope++; 417 goto bad; 418 } 419 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 420 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 421 ip6->ip6_dst.s6_addr16[1]) { 422 ip6stat.ip6s_badscope++; 423 goto bad; 424 } 425 } 426 427 #ifdef PFIL_HOOKS 428 /* 429 * Run through list of hooks for input packets. 430 * 431 * NB: Beware of the destination address changing 432 * (e.g. by NAT rewriting). When this happens, 433 * tell ip6_forward to do the right thing. 434 */ 435 odst = ip6->ip6_dst; 436 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) 437 return; 438 if (m == NULL) /* consumed by filter */ 439 return; 440 ip6 = mtod(m, struct ip6_hdr *); 441 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 442 #endif /* PFIL_HOOKS */ 443 444 /* 445 * Check with the firewall... 446 */ 447 if (ip6_fw_enable && ip6_fw_chk_ptr) { 448 u_short port = 0; 449 /* If ipfw says divert, we have to just drop packet */ 450 /* use port as a dummy argument */ 451 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 452 m_freem(m); 453 m = NULL; 454 } 455 if (!m) 456 return; 457 } 458 459 /* 460 * construct source and destination address structures with 461 * disambiguating their scope zones (if there is ambiguity). 462 * XXX: sin6_family and sin6_len will NOT be referred to, but we fill 463 * in these fields just in case. 464 */ 465 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_src, &srczone) || 466 in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst, &dstzone)) { 467 /* 468 * Note that these generic checks cover cases that src or 469 * dst are the loopback address and the receiving interface 470 * is not loopback. 471 */ 472 ip6stat.ip6s_badscope++; 473 goto bad; 474 } 475 476 bzero(&sa6, sizeof(sa6)); 477 sa6.sin6_family = AF_INET6; 478 sa6.sin6_len = sizeof(struct sockaddr_in6); 479 480 sa6.sin6_addr = ip6->ip6_src; 481 sa6.sin6_scope_id = srczone; 482 if (in6_embedscope(&ip6->ip6_src, &sa6, NULL, NULL)) { 483 /* XXX: should not happen */ 484 ip6stat.ip6s_badscope++; 485 goto bad; 486 } 487 488 sa6.sin6_addr = ip6->ip6_dst; 489 sa6.sin6_scope_id = dstzone; 490 if (in6_embedscope(&ip6->ip6_dst, &sa6, NULL, NULL)) { 491 /* XXX: should not happen */ 492 ip6stat.ip6s_badscope++; 493 goto bad; 494 } 495 496 /* XXX: ff01::%ifN awareness is not merged, yet. */ 497 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_src)) 498 ip6->ip6_src.s6_addr16[1] = 0; 499 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) 500 ip6->ip6_dst.s6_addr16[1] = 0; 501 502 /* 503 * Multicast check 504 */ 505 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 506 struct in6_multi *in6m = 0; 507 508 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 509 /* 510 * See if we belong to the destination multicast group on the 511 * arrival interface. 512 */ 513 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 514 if (in6m) 515 ours = 1; 516 else if (!ip6_mrouter) { 517 ip6stat.ip6s_notmember++; 518 ip6stat.ip6s_cantforward++; 519 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 520 goto bad; 521 } 522 deliverifp = m->m_pkthdr.rcvif; 523 goto hbhcheck; 524 } 525 526 /* 527 * Unicast check 528 */ 529 if (ip6_forward_rt.ro_rt != NULL && 530 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 531 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 532 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 533 ip6stat.ip6s_forward_cachehit++; 534 else { 535 struct sockaddr_in6 *dst6; 536 537 if (ip6_forward_rt.ro_rt) { 538 /* route is down or destination is different */ 539 ip6stat.ip6s_forward_cachemiss++; 540 RTFREE(ip6_forward_rt.ro_rt); 541 ip6_forward_rt.ro_rt = 0; 542 } 543 544 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 545 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 546 dst6->sin6_len = sizeof(struct sockaddr_in6); 547 dst6->sin6_family = AF_INET6; 548 dst6->sin6_addr = ip6->ip6_dst; 549 550 rtalloc((struct route *)&ip6_forward_rt); 551 } 552 553 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 554 555 /* 556 * Accept the packet if the forwarding interface to the destination 557 * according to the routing table is the loopback interface, 558 * unless the associated route has a gateway. 559 * Note that this approach causes to accept a packet if there is a 560 * route to the loopback interface for the destination of the packet. 561 * But we think it's even useful in some situations, e.g. when using 562 * a special daemon which wants to intercept the packet. 563 * 564 * XXX: some OSes automatically make a cloned route for the destination 565 * of an outgoing packet. If the outgoing interface of the packet 566 * is a loopback one, the kernel would consider the packet to be 567 * accepted, even if we have no such address assinged on the interface. 568 * We check the cloned flag of the route entry to reject such cases, 569 * assuming that route entries for our own addresses are not made by 570 * cloning (it should be true because in6_addloop explicitly installs 571 * the host route). However, we might have to do an explicit check 572 * while it would be less efficient. Or, should we rather install a 573 * reject route for such a case? 574 */ 575 if (ip6_forward_rt.ro_rt && 576 (ip6_forward_rt.ro_rt->rt_flags & 577 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 578 #ifdef RTF_WASCLONED 579 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 580 #endif 581 #ifdef RTF_CLONED 582 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 583 #endif 584 #if 0 585 /* 586 * The check below is redundant since the comparison of 587 * the destination and the key of the rtentry has 588 * already done through looking up the routing table. 589 */ 590 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 591 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 592 #endif 593 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 594 struct in6_ifaddr *ia6 = 595 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 596 597 /* 598 * record address information into m_tag. 599 */ 600 (void)ip6_setdstifaddr(m, ia6); 601 602 /* 603 * packets to a tentative, duplicated, or somehow invalid 604 * address must not be accepted. 605 */ 606 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 607 /* this address is ready */ 608 ours = 1; 609 deliverifp = ia6->ia_ifp; /* correct? */ 610 /* Count the packet in the ip address stats */ 611 ia6->ia_ifa.if_ipackets++; 612 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 613 goto hbhcheck; 614 } else { 615 /* address is not ready, so discard the packet. */ 616 nd6log((LOG_INFO, 617 "ip6_input: packet to an unready address %s->%s\n", 618 ip6_sprintf(&ip6->ip6_src), 619 ip6_sprintf(&ip6->ip6_dst))); 620 621 goto bad; 622 } 623 } 624 625 /* 626 * FAITH (Firewall Aided Internet Translator) 627 */ 628 if (ip6_keepfaith) { 629 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 630 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 631 /* XXX do we need more sanity checks? */ 632 ours = 1; 633 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 634 goto hbhcheck; 635 } 636 } 637 638 /* 639 * Now there is no reason to process the packet if it's not our own 640 * and we're not a router. 641 */ 642 if (!ip6_forwarding) { 643 ip6stat.ip6s_cantforward++; 644 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 645 goto bad; 646 } 647 648 hbhcheck: 649 /* 650 * record address information into m_tag, if we don't have one yet. 651 * note that we are unable to record it, if the address is not listed 652 * as our interface address (e.g. multicast addresses, addresses 653 * within FAITH prefixes and such). 654 */ 655 if (deliverifp && !ip6_getdstifaddr(m)) { 656 struct in6_ifaddr *ia6; 657 658 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 659 if (ia6) { 660 if (!ip6_setdstifaddr(m, ia6)) { 661 /* 662 * XXX maybe we should drop the packet here, 663 * as we could not provide enough information 664 * to the upper layers. 665 */ 666 } 667 } 668 } 669 670 /* 671 * Process Hop-by-Hop options header if it's contained. 672 * m may be modified in ip6_hopopts_input(). 673 * If a JumboPayload option is included, plen will also be modified. 674 */ 675 plen = (u_int32_t)ntohs(ip6->ip6_plen); 676 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 677 struct ip6_hbh *hbh; 678 679 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 680 #if 0 /*touches NULL pointer*/ 681 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 682 #endif 683 return; /* m have already been freed */ 684 } 685 686 /* adjust pointer */ 687 ip6 = mtod(m, struct ip6_hdr *); 688 689 /* 690 * if the payload length field is 0 and the next header field 691 * indicates Hop-by-Hop Options header, then a Jumbo Payload 692 * option MUST be included. 693 */ 694 if (ip6->ip6_plen == 0 && plen == 0) { 695 /* 696 * Note that if a valid jumbo payload option is 697 * contained, ip6_hopopts_input() must set a valid 698 * (non-zero) payload length to the variable plen. 699 */ 700 ip6stat.ip6s_badoptions++; 701 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 702 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 703 icmp6_error(m, ICMP6_PARAM_PROB, 704 ICMP6_PARAMPROB_HEADER, 705 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 706 return; 707 } 708 #ifndef PULLDOWN_TEST 709 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 710 hbh = (struct ip6_hbh *)(ip6 + 1); 711 #else 712 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 713 sizeof(struct ip6_hbh)); 714 if (hbh == NULL) { 715 ip6stat.ip6s_tooshort++; 716 return; 717 } 718 #endif 719 nxt = hbh->ip6h_nxt; 720 721 /* 722 * accept the packet if a router alert option is included 723 * and we act as an IPv6 router. 724 */ 725 if (rtalert != ~0 && ip6_forwarding) 726 ours = 1; 727 } else 728 nxt = ip6->ip6_nxt; 729 730 /* 731 * Check that the amount of data in the buffers 732 * is as at least much as the IPv6 header would have us expect. 733 * Trim mbufs if longer than we expect. 734 * Drop packet if shorter than we expect. 735 */ 736 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 737 ip6stat.ip6s_tooshort++; 738 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 739 goto bad; 740 } 741 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 742 if (m->m_len == m->m_pkthdr.len) { 743 m->m_len = sizeof(struct ip6_hdr) + plen; 744 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 745 } else 746 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 747 } 748 749 /* 750 * Forward if desirable. 751 */ 752 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 753 /* 754 * If we are acting as a multicast router, all 755 * incoming multicast packets are passed to the 756 * kernel-level multicast forwarding function. 757 * The packet is returned (relatively) intact; if 758 * ip6_mforward() returns a non-zero value, the packet 759 * must be discarded, else it may be accepted below. 760 */ 761 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 762 ip6stat.ip6s_cantforward++; 763 m_freem(m); 764 return; 765 } 766 if (!ours) { 767 m_freem(m); 768 return; 769 } 770 } else if (!ours) { 771 ip6_forward(m, srcrt); 772 return; 773 } 774 775 ip6 = mtod(m, struct ip6_hdr *); 776 777 /* 778 * Malicious party may be able to use IPv4 mapped addr to confuse 779 * tcp/udp stack and bypass security checks (act as if it was from 780 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 781 * 782 * For SIIT end node behavior, you may want to disable the check. 783 * However, you will become vulnerable to attacks using IPv4 mapped 784 * source. 785 */ 786 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 787 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 788 ip6stat.ip6s_badscope++; 789 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 790 goto bad; 791 } 792 793 /* 794 * Tell launch routine the next header 795 */ 796 ip6stat.ip6s_delivered++; 797 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 798 nest = 0; 799 800 while (nxt != IPPROTO_DONE) { 801 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 802 ip6stat.ip6s_toomanyhdr++; 803 goto bad; 804 } 805 806 /* 807 * protection against faulty packet - there should be 808 * more sanity checks in header chain processing. 809 */ 810 if (m->m_pkthdr.len < off) { 811 ip6stat.ip6s_tooshort++; 812 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 813 goto bad; 814 } 815 816 #ifdef IPSEC 817 /* 818 * enforce IPsec policy checking if we are seeing last header. 819 * note that we do not visit this with protocols with pcb layer 820 * code - like udp/tcp/raw ip. 821 */ 822 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 823 ipsec6_in_reject(m, NULL)) { 824 ipsec6stat.in_polvio++; 825 goto bad; 826 } 827 #endif 828 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 829 } 830 return; 831 bad: 832 m_freem(m); 833 } 834 835 /* 836 * set/grab in6_ifaddr correspond to IPv6 destination address. 837 * XXX backward compatibility wrapper 838 */ 839 static struct ip6aux * 840 ip6_setdstifaddr(m, ia6) 841 struct mbuf *m; 842 struct in6_ifaddr *ia6; 843 { 844 struct ip6aux *ip6a; 845 846 ip6a = ip6_addaux(m); 847 if (ip6a) 848 ip6a->ip6a_dstia6 = ia6; 849 return ip6a; /* NULL if failed to set */ 850 } 851 852 struct in6_ifaddr * 853 ip6_getdstifaddr(m) 854 struct mbuf *m; 855 { 856 struct ip6aux *ip6a; 857 858 ip6a = ip6_findaux(m); 859 if (ip6a) 860 return ip6a->ip6a_dstia6; 861 else 862 return NULL; 863 } 864 865 /* 866 * Hop-by-Hop options header processing. If a valid jumbo payload option is 867 * included, the real payload length will be stored in plenp. 868 */ 869 static int 870 ip6_hopopts_input(plenp, rtalertp, mp, offp) 871 u_int32_t *plenp; 872 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 873 struct mbuf **mp; 874 int *offp; 875 { 876 struct mbuf *m = *mp; 877 int off = *offp, hbhlen; 878 struct ip6_hbh *hbh; 879 u_int8_t *opt; 880 881 /* validation of the length of the header */ 882 #ifndef PULLDOWN_TEST 883 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 884 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 885 hbhlen = (hbh->ip6h_len + 1) << 3; 886 887 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 888 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 889 #else 890 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 891 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 892 if (hbh == NULL) { 893 ip6stat.ip6s_tooshort++; 894 return -1; 895 } 896 hbhlen = (hbh->ip6h_len + 1) << 3; 897 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 898 hbhlen); 899 if (hbh == NULL) { 900 ip6stat.ip6s_tooshort++; 901 return -1; 902 } 903 #endif 904 off += hbhlen; 905 hbhlen -= sizeof(struct ip6_hbh); 906 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 907 908 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 909 hbhlen, rtalertp, plenp) < 0) 910 return (-1); 911 912 *offp = off; 913 *mp = m; 914 return (0); 915 } 916 917 /* 918 * Search header for all Hop-by-hop options and process each option. 919 * This function is separate from ip6_hopopts_input() in order to 920 * handle a case where the sending node itself process its hop-by-hop 921 * options header. In such a case, the function is called from ip6_output(). 922 * 923 * The function assumes that hbh header is located right after the IPv6 header 924 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 925 * opthead + hbhlen is located in continuous memory region. 926 */ 927 int 928 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 929 struct mbuf *m; 930 u_int8_t *opthead; 931 int hbhlen; 932 u_int32_t *rtalertp; 933 u_int32_t *plenp; 934 { 935 struct ip6_hdr *ip6; 936 int optlen = 0; 937 u_int8_t *opt = opthead; 938 u_int16_t rtalert_val; 939 u_int32_t jumboplen; 940 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 941 942 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 943 switch (*opt) { 944 case IP6OPT_PAD1: 945 optlen = 1; 946 break; 947 case IP6OPT_PADN: 948 if (hbhlen < IP6OPT_MINLEN) { 949 ip6stat.ip6s_toosmall++; 950 goto bad; 951 } 952 optlen = *(opt + 1) + 2; 953 break; 954 case IP6OPT_ROUTER_ALERT: 955 /* XXX may need check for alignment */ 956 if (hbhlen < IP6OPT_RTALERT_LEN) { 957 ip6stat.ip6s_toosmall++; 958 goto bad; 959 } 960 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 961 /* XXX stat */ 962 icmp6_error(m, ICMP6_PARAM_PROB, 963 ICMP6_PARAMPROB_HEADER, 964 erroff + opt + 1 - opthead); 965 return (-1); 966 } 967 optlen = IP6OPT_RTALERT_LEN; 968 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 969 *rtalertp = ntohs(rtalert_val); 970 break; 971 case IP6OPT_JUMBO: 972 /* XXX may need check for alignment */ 973 if (hbhlen < IP6OPT_JUMBO_LEN) { 974 ip6stat.ip6s_toosmall++; 975 goto bad; 976 } 977 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 978 /* XXX stat */ 979 icmp6_error(m, ICMP6_PARAM_PROB, 980 ICMP6_PARAMPROB_HEADER, 981 erroff + opt + 1 - opthead); 982 return (-1); 983 } 984 optlen = IP6OPT_JUMBO_LEN; 985 986 /* 987 * IPv6 packets that have non 0 payload length 988 * must not contain a jumbo payload option. 989 */ 990 ip6 = mtod(m, struct ip6_hdr *); 991 if (ip6->ip6_plen) { 992 ip6stat.ip6s_badoptions++; 993 icmp6_error(m, ICMP6_PARAM_PROB, 994 ICMP6_PARAMPROB_HEADER, 995 erroff + opt - opthead); 996 return (-1); 997 } 998 999 /* 1000 * We may see jumbolen in unaligned location, so 1001 * we'd need to perform bcopy(). 1002 */ 1003 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1004 jumboplen = (u_int32_t)htonl(jumboplen); 1005 1006 #if 1 1007 /* 1008 * if there are multiple jumbo payload options, 1009 * *plenp will be non-zero and the packet will be 1010 * rejected. 1011 * the behavior may need some debate in ipngwg - 1012 * multiple options does not make sense, however, 1013 * there's no explicit mention in specification. 1014 */ 1015 if (*plenp != 0) { 1016 ip6stat.ip6s_badoptions++; 1017 icmp6_error(m, ICMP6_PARAM_PROB, 1018 ICMP6_PARAMPROB_HEADER, 1019 erroff + opt + 2 - opthead); 1020 return (-1); 1021 } 1022 #endif 1023 1024 /* 1025 * jumbo payload length must be larger than 65535. 1026 */ 1027 if (jumboplen <= IPV6_MAXPACKET) { 1028 ip6stat.ip6s_badoptions++; 1029 icmp6_error(m, ICMP6_PARAM_PROB, 1030 ICMP6_PARAMPROB_HEADER, 1031 erroff + opt + 2 - opthead); 1032 return (-1); 1033 } 1034 *plenp = jumboplen; 1035 1036 break; 1037 default: /* unknown option */ 1038 if (hbhlen < IP6OPT_MINLEN) { 1039 ip6stat.ip6s_toosmall++; 1040 goto bad; 1041 } 1042 optlen = ip6_unknown_opt(opt, m, 1043 erroff + opt - opthead); 1044 if (optlen == -1) 1045 return (-1); 1046 optlen += 2; 1047 break; 1048 } 1049 } 1050 1051 return (0); 1052 1053 bad: 1054 m_freem(m); 1055 return (-1); 1056 } 1057 1058 /* 1059 * Unknown option processing. 1060 * The third argument `off' is the offset from the IPv6 header to the option, 1061 * which is necessary if the IPv6 header the and option header and IPv6 header 1062 * is not continuous in order to return an ICMPv6 error. 1063 */ 1064 int 1065 ip6_unknown_opt(optp, m, off) 1066 u_int8_t *optp; 1067 struct mbuf *m; 1068 int off; 1069 { 1070 struct ip6_hdr *ip6; 1071 1072 switch (IP6OPT_TYPE(*optp)) { 1073 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1074 return ((int)*(optp + 1)); 1075 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1076 m_freem(m); 1077 return (-1); 1078 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1079 ip6stat.ip6s_badoptions++; 1080 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1081 return (-1); 1082 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1083 ip6stat.ip6s_badoptions++; 1084 ip6 = mtod(m, struct ip6_hdr *); 1085 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1086 (m->m_flags & (M_BCAST|M_MCAST))) 1087 m_freem(m); 1088 else 1089 icmp6_error(m, ICMP6_PARAM_PROB, 1090 ICMP6_PARAMPROB_OPTION, off); 1091 return (-1); 1092 } 1093 1094 m_freem(m); /* XXX: NOTREACHED */ 1095 return (-1); 1096 } 1097 1098 /* 1099 * Create the "control" list for this pcb. 1100 * The function will not modify mbuf chain at all. 1101 * 1102 * with KAME mbuf chain restriction: 1103 * The routine will be called from upper layer handlers like tcp6_input(). 1104 * Thus the routine assumes that the caller (tcp6_input) have already 1105 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1106 * very first mbuf on the mbuf chain. 1107 */ 1108 void 1109 ip6_savecontrol(in6p, m, mp) 1110 struct inpcb *in6p; 1111 struct mbuf *m, **mp; 1112 { 1113 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1114 struct thread *td = curthread; /* XXX */ 1115 int privileged = 0; 1116 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1117 1118 if (td && !suser(td)) 1119 privileged++; 1120 1121 #ifdef SO_TIMESTAMP 1122 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1123 struct timeval tv; 1124 1125 microtime(&tv); 1126 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1127 SCM_TIMESTAMP, SOL_SOCKET); 1128 if (*mp) 1129 mp = &(*mp)->m_next; 1130 } 1131 #endif 1132 1133 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) 1134 return; 1135 1136 /* RFC 2292 sec. 5 */ 1137 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1138 struct in6_pktinfo pi6; 1139 1140 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1141 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1142 pi6.ipi6_ifindex = 1143 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1144 1145 *mp = sbcreatecontrol((caddr_t) &pi6, 1146 sizeof(struct in6_pktinfo), 1147 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1148 if (*mp) 1149 mp = &(*mp)->m_next; 1150 } 1151 1152 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1153 int hlim = ip6->ip6_hlim & 0xff; 1154 1155 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1156 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1157 if (*mp) 1158 mp = &(*mp)->m_next; 1159 } 1160 1161 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1162 u_int32_t flowinfo; 1163 int tclass; 1164 1165 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1166 flowinfo >>= 20; 1167 1168 tclass = flowinfo & 0xff; 1169 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1170 IPV6_TCLASS, IPPROTO_IPV6); 1171 if (*mp) 1172 mp = &(*mp)->m_next; 1173 } 1174 1175 /* 1176 * IPV6_HOPOPTS socket option. We require super-user privilege 1177 * for the option, but it might be too strict, since there might 1178 * be some hop-by-hop options which can be returned to normal user. 1179 * See RFC 2292 section 6. 1180 */ 1181 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1182 #ifdef DIAGNOSTIC 1183 if (!privileged) 1184 panic("IN6P_HOPOPTS is set for unprivileged socket"); 1185 #endif 1186 /* 1187 * Check if a hop-by-hop options header is contatined in the 1188 * received packet, and if so, store the options as ancillary 1189 * data. Note that a hop-by-hop options header must be 1190 * just after the IPv6 header, which is assured through the 1191 * IPv6 input processing. 1192 */ 1193 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1194 struct ip6_hbh *hbh; 1195 int hbhlen = 0; 1196 #ifdef PULLDOWN_TEST 1197 struct mbuf *ext; 1198 #endif 1199 1200 #ifndef PULLDOWN_TEST 1201 hbh = (struct ip6_hbh *)(ip6 + 1); 1202 hbhlen = (hbh->ip6h_len + 1) << 3; 1203 #else 1204 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1205 ip6->ip6_nxt); 1206 if (ext == NULL) { 1207 ip6stat.ip6s_tooshort++; 1208 return; 1209 } 1210 hbh = mtod(ext, struct ip6_hbh *); 1211 hbhlen = (hbh->ip6h_len + 1) << 3; 1212 if (hbhlen != ext->m_len) { 1213 m_freem(ext); 1214 ip6stat.ip6s_tooshort++; 1215 return; 1216 } 1217 #endif 1218 1219 /* 1220 * XXX: We copy the whole header even if a 1221 * jumbo payload option is included, the option which 1222 * is to be removed before returning according to 1223 * RFC2292. 1224 * Note: this constraint is removed in 2292bis. 1225 */ 1226 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1227 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1228 IPPROTO_IPV6); 1229 if (*mp) 1230 mp = &(*mp)->m_next; 1231 #ifdef PULLDOWN_TEST 1232 m_freem(ext); 1233 #endif 1234 } 1235 } 1236 1237 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1238 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1239 1240 /* 1241 * Search for destination options headers or routing 1242 * header(s) through the header chain, and stores each 1243 * header as ancillary data. 1244 * Note that the order of the headers remains in 1245 * the chain of ancillary data. 1246 */ 1247 while (1) { /* is explicit loop prevention necessary? */ 1248 struct ip6_ext *ip6e = NULL; 1249 int elen; 1250 #ifdef PULLDOWN_TEST 1251 struct mbuf *ext = NULL; 1252 #endif 1253 1254 /* 1255 * if it is not an extension header, don't try to 1256 * pull it from the chain. 1257 */ 1258 switch (nxt) { 1259 case IPPROTO_DSTOPTS: 1260 case IPPROTO_ROUTING: 1261 case IPPROTO_HOPOPTS: 1262 case IPPROTO_AH: /* is it possible? */ 1263 break; 1264 default: 1265 goto loopend; 1266 } 1267 1268 #ifndef PULLDOWN_TEST 1269 if (off + sizeof(*ip6e) > m->m_len) 1270 goto loopend; 1271 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1272 if (nxt == IPPROTO_AH) 1273 elen = (ip6e->ip6e_len + 2) << 2; 1274 else 1275 elen = (ip6e->ip6e_len + 1) << 3; 1276 if (off + elen > m->m_len) 1277 goto loopend; 1278 #else 1279 ext = ip6_pullexthdr(m, off, nxt); 1280 if (ext == NULL) { 1281 ip6stat.ip6s_tooshort++; 1282 return; 1283 } 1284 ip6e = mtod(ext, struct ip6_ext *); 1285 if (nxt == IPPROTO_AH) 1286 elen = (ip6e->ip6e_len + 2) << 2; 1287 else 1288 elen = (ip6e->ip6e_len + 1) << 3; 1289 if (elen != ext->m_len) { 1290 m_freem(ext); 1291 ip6stat.ip6s_tooshort++; 1292 return; 1293 } 1294 #endif 1295 1296 switch (nxt) { 1297 case IPPROTO_DSTOPTS: 1298 if (!(in6p->in6p_flags & IN6P_DSTOPTS)) 1299 break; 1300 1301 /* 1302 * We also require super-user privilege for 1303 * the option. See comments on IN6_HOPOPTS. 1304 */ 1305 if (!privileged) 1306 break; 1307 1308 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1309 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1310 IPPROTO_IPV6); 1311 if (*mp) 1312 mp = &(*mp)->m_next; 1313 break; 1314 case IPPROTO_ROUTING: 1315 if (!in6p->in6p_flags & IN6P_RTHDR) 1316 break; 1317 1318 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1319 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1320 IPPROTO_IPV6); 1321 if (*mp) 1322 mp = &(*mp)->m_next; 1323 break; 1324 case IPPROTO_HOPOPTS: 1325 case IPPROTO_AH: /* is it possible? */ 1326 break; 1327 1328 default: 1329 /* 1330 * other cases have been filtered in the above. 1331 * none will visit this case. here we supply 1332 * the code just in case (nxt overwritten or 1333 * other cases). 1334 */ 1335 #ifdef PULLDOWN_TEST 1336 m_freem(ext); 1337 #endif 1338 goto loopend; 1339 1340 } 1341 1342 /* proceed with the next header. */ 1343 off += elen; 1344 nxt = ip6e->ip6e_nxt; 1345 ip6e = NULL; 1346 #ifdef PULLDOWN_TEST 1347 m_freem(ext); 1348 ext = NULL; 1349 #endif 1350 } 1351 loopend: 1352 ; 1353 } 1354 1355 #undef IS2292 1356 } 1357 1358 void 1359 ip6_notify_pmtu(in6p, dst, mtu) 1360 struct inpcb *in6p; 1361 struct sockaddr_in6 *dst; 1362 u_int32_t *mtu; 1363 { 1364 struct socket *so; 1365 struct mbuf *m_mtu; 1366 struct ip6_mtuinfo mtuctl; 1367 1368 so = in6p->inp_socket; 1369 1370 if (mtu == NULL) 1371 return; 1372 1373 #ifdef DIAGNOSTIC 1374 if (so == NULL) /* I believe this is impossible */ 1375 panic("ip6_notify_pmtu: socket is NULL"); 1376 #endif 1377 1378 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1379 mtuctl.ip6m_mtu = *mtu; 1380 mtuctl.ip6m_addr = *dst; 1381 in6_recoverscope(&mtuctl.ip6m_addr, &mtuctl.ip6m_addr.sin6_addr, NULL); 1382 1383 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1384 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1385 return; 1386 1387 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1388 == 0) { 1389 m_freem(m_mtu); 1390 /* XXX: should count statistics */ 1391 } else 1392 sorwakeup(so); 1393 1394 return; 1395 } 1396 1397 #ifdef PULLDOWN_TEST 1398 /* 1399 * pull single extension header from mbuf chain. returns single mbuf that 1400 * contains the result, or NULL on error. 1401 */ 1402 static struct mbuf * 1403 ip6_pullexthdr(m, off, nxt) 1404 struct mbuf *m; 1405 size_t off; 1406 int nxt; 1407 { 1408 struct ip6_ext ip6e; 1409 size_t elen; 1410 struct mbuf *n; 1411 1412 #ifdef DIAGNOSTIC 1413 switch (nxt) { 1414 case IPPROTO_DSTOPTS: 1415 case IPPROTO_ROUTING: 1416 case IPPROTO_HOPOPTS: 1417 case IPPROTO_AH: /* is it possible? */ 1418 break; 1419 default: 1420 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1421 } 1422 #endif 1423 1424 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1425 if (nxt == IPPROTO_AH) 1426 elen = (ip6e.ip6e_len + 2) << 2; 1427 else 1428 elen = (ip6e.ip6e_len + 1) << 3; 1429 1430 MGET(n, M_DONTWAIT, MT_DATA); 1431 if (n && elen >= MLEN) { 1432 MCLGET(n, M_DONTWAIT); 1433 if ((n->m_flags & M_EXT) == 0) { 1434 m_free(n); 1435 n = NULL; 1436 } 1437 } 1438 if (!n) 1439 return NULL; 1440 1441 n->m_len = 0; 1442 if (elen >= M_TRAILINGSPACE(n)) { 1443 m_free(n); 1444 return NULL; 1445 } 1446 1447 m_copydata(m, off, elen, mtod(n, caddr_t)); 1448 n->m_len = elen; 1449 return n; 1450 } 1451 #endif 1452 1453 /* 1454 * Get pointer to the previous header followed by the header 1455 * currently processed. 1456 * XXX: This function supposes that 1457 * M includes all headers, 1458 * the next header field and the header length field of each header 1459 * are valid, and 1460 * the sum of each header length equals to OFF. 1461 * Because of these assumptions, this function must be called very 1462 * carefully. Moreover, it will not be used in the near future when 1463 * we develop `neater' mechanism to process extension headers. 1464 */ 1465 char * 1466 ip6_get_prevhdr(m, off) 1467 struct mbuf *m; 1468 int off; 1469 { 1470 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1471 1472 if (off == sizeof(struct ip6_hdr)) 1473 return (&ip6->ip6_nxt); 1474 else { 1475 int len, nxt; 1476 struct ip6_ext *ip6e = NULL; 1477 1478 nxt = ip6->ip6_nxt; 1479 len = sizeof(struct ip6_hdr); 1480 while (len < off) { 1481 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1482 1483 switch (nxt) { 1484 case IPPROTO_FRAGMENT: 1485 len += sizeof(struct ip6_frag); 1486 break; 1487 case IPPROTO_AH: 1488 len += (ip6e->ip6e_len + 2) << 2; 1489 break; 1490 default: 1491 len += (ip6e->ip6e_len + 1) << 3; 1492 break; 1493 } 1494 nxt = ip6e->ip6e_nxt; 1495 } 1496 if (ip6e) 1497 return (&ip6e->ip6e_nxt); 1498 else 1499 return NULL; 1500 } 1501 } 1502 1503 /* 1504 * get next header offset. m will be retained. 1505 */ 1506 int 1507 ip6_nexthdr(m, off, proto, nxtp) 1508 struct mbuf *m; 1509 int off; 1510 int proto; 1511 int *nxtp; 1512 { 1513 struct ip6_hdr ip6; 1514 struct ip6_ext ip6e; 1515 struct ip6_frag fh; 1516 1517 /* just in case */ 1518 if (m == NULL) 1519 panic("ip6_nexthdr: m == NULL"); 1520 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1521 return -1; 1522 1523 switch (proto) { 1524 case IPPROTO_IPV6: 1525 if (m->m_pkthdr.len < off + sizeof(ip6)) 1526 return -1; 1527 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1528 if (nxtp) 1529 *nxtp = ip6.ip6_nxt; 1530 off += sizeof(ip6); 1531 return off; 1532 1533 case IPPROTO_FRAGMENT: 1534 /* 1535 * terminate parsing if it is not the first fragment, 1536 * it does not make sense to parse through it. 1537 */ 1538 if (m->m_pkthdr.len < off + sizeof(fh)) 1539 return -1; 1540 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1541 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1542 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1543 return -1; 1544 if (nxtp) 1545 *nxtp = fh.ip6f_nxt; 1546 off += sizeof(struct ip6_frag); 1547 return off; 1548 1549 case IPPROTO_AH: 1550 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1551 return -1; 1552 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1553 if (nxtp) 1554 *nxtp = ip6e.ip6e_nxt; 1555 off += (ip6e.ip6e_len + 2) << 2; 1556 return off; 1557 1558 case IPPROTO_HOPOPTS: 1559 case IPPROTO_ROUTING: 1560 case IPPROTO_DSTOPTS: 1561 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1562 return -1; 1563 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1564 if (nxtp) 1565 *nxtp = ip6e.ip6e_nxt; 1566 off += (ip6e.ip6e_len + 1) << 3; 1567 return off; 1568 1569 case IPPROTO_NONE: 1570 case IPPROTO_ESP: 1571 case IPPROTO_IPCOMP: 1572 /* give up */ 1573 return -1; 1574 1575 default: 1576 return -1; 1577 } 1578 1579 return -1; 1580 } 1581 1582 /* 1583 * get offset for the last header in the chain. m will be kept untainted. 1584 */ 1585 int 1586 ip6_lasthdr(m, off, proto, nxtp) 1587 struct mbuf *m; 1588 int off; 1589 int proto; 1590 int *nxtp; 1591 { 1592 int newoff; 1593 int nxt; 1594 1595 if (!nxtp) { 1596 nxt = -1; 1597 nxtp = &nxt; 1598 } 1599 while (1) { 1600 newoff = ip6_nexthdr(m, off, proto, nxtp); 1601 if (newoff < 0) 1602 return off; 1603 else if (newoff < off) 1604 return -1; /* invalid */ 1605 else if (newoff == off) 1606 return newoff; 1607 1608 off = newoff; 1609 proto = *nxtp; 1610 } 1611 } 1612 1613 struct ip6aux * 1614 ip6_addaux(m) 1615 struct mbuf *m; 1616 { 1617 struct m_tag *mtag; 1618 1619 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1620 if (!mtag) { 1621 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1622 M_NOWAIT); 1623 if (mtag) { 1624 m_tag_prepend(m, mtag); 1625 bzero(mtag + 1, sizeof(struct ip6aux)); 1626 } 1627 } 1628 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1629 } 1630 1631 struct ip6aux * 1632 ip6_findaux(m) 1633 struct mbuf *m; 1634 { 1635 struct m_tag *mtag; 1636 1637 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1638 return mtag ? (struct ip6aux *)(mtag + 1) : NULL; 1639 } 1640 1641 void 1642 ip6_delaux(m) 1643 struct mbuf *m; 1644 { 1645 struct m_tag *mtag; 1646 1647 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1648 if (mtag) 1649 m_tag_delete(m, mtag); 1650 } 1651 1652 /* 1653 * System control for IP6 1654 */ 1655 1656 u_char inet6ctlerrmap[PRC_NCMDS] = { 1657 0, 0, 0, 0, 1658 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1659 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1660 EMSGSIZE, EHOSTUNREACH, 0, 0, 1661 0, 0, 0, 0, 1662 ENOPROTOOPT 1663 }; 1664