1 /* $FreeBSD: src/sys/netinet6/ip6_input.c,v 1.11.2.15 2003/01/24 05:11:35 sam Exp $ */ 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. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_ip6fw.h" 65 #include "opt_inet.h" 66 #include "opt_inet6.h" 67 #include "opt_ipsec.h" 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/malloc.h> 72 #include <sys/mbuf.h> 73 #include <sys/domain.h> 74 #include <sys/protosw.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/errno.h> 78 #include <sys/time.h> 79 #include <sys/kernel.h> 80 #include <sys/syslog.h> 81 #include <sys/proc.h> 82 #include <sys/priv.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 #include <net/pfil.h> 90 91 #include <sys/thread2.h> 92 #include <sys/msgport2.h> 93 #include <net/netmsg2.h> 94 #include <net/netisr2.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_systm.h> 98 #ifdef INET 99 #include <netinet/ip.h> 100 #include <netinet/ip_icmp.h> 101 #endif /* INET */ 102 #include <netinet/ip6.h> 103 #include <netinet6/in6_var.h> 104 #include <netinet6/ip6_var.h> 105 #include <netinet/in_pcb.h> 106 #include <netinet/icmp6.h> 107 #include <netinet6/scope6_var.h> 108 #include <netinet6/in6_ifattach.h> 109 #include <netinet6/nd6.h> 110 111 #ifdef IPSEC 112 #include <netinet6/ipsec.h> 113 #ifdef INET6 114 #include <netinet6/ipsec6.h> 115 #endif 116 #endif 117 118 #ifdef FAST_IPSEC 119 #include <netproto/ipsec/ipsec.h> 120 #include <netproto/ipsec/ipsec6.h> 121 #define IPSEC 122 #endif /* FAST_IPSEC */ 123 124 #include <net/ip6fw/ip6_fw.h> 125 126 #include <netinet6/ip6protosw.h> 127 128 #include <net/net_osdep.h> 129 130 extern struct domain inet6domain; 131 extern struct protosw inet6sw[]; 132 133 u_char ip6_protox[IPPROTO_MAX]; 134 struct in6_ifaddr *in6_ifaddr; 135 136 int ip6_forward_srcrt; /* XXX */ 137 int ip6_sourcecheck; /* XXX */ 138 int ip6_sourcecheck_interval; /* XXX */ 139 140 int ip6_ours_check_algorithm; 141 142 struct pfil_head inet6_pfil_hook; 143 144 /* firewall hooks */ 145 ip6_fw_chk_t *ip6_fw_chk_ptr; 146 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 147 int ip6_fw_enable = 1; 148 149 struct ip6stat ip6stat; 150 151 static void ip6_init2 (void *); 152 static struct ip6aux *ip6_setdstifaddr (struct mbuf *, struct in6_ifaddr *); 153 static int ip6_hopopts_input (u_int32_t *, u_int32_t *, struct mbuf **, int *); 154 static void ip6_input(netmsg_t msg); 155 #ifdef PULLDOWN_TEST 156 static struct mbuf *ip6_pullexthdr (struct mbuf *, size_t, int); 157 #endif 158 static void transport6_processing_handler(netmsg_t netmsg); 159 160 /* 161 * IP6 initialization: fill in IP6 protocol switch table. 162 * All protocols not implemented in kernel go to raw IP6 protocol handler. 163 */ 164 void 165 ip6_init(void) 166 { 167 struct protosw *pr; 168 int i; 169 struct timeval tv; 170 171 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 172 if (pr == NULL) 173 panic("ip6_init"); 174 for (i = 0; i < IPPROTO_MAX; i++) 175 ip6_protox[i] = pr - inet6sw; 176 for (pr = inet6domain.dom_protosw; 177 pr < inet6domain.dom_protoswNPROTOSW; pr++) 178 if (pr->pr_domain->dom_family == PF_INET6 && 179 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 180 ip6_protox[pr->pr_protocol] = pr - inet6sw; 181 182 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 183 inet6_pfil_hook.ph_af = AF_INET6; 184 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) { 185 kprintf("%s: WARNING: unable to register pfil hook, " 186 "error %d\n", __func__, i); 187 } 188 189 netisr_register(NETISR_IPV6, ip6_input, NULL); /* XXX hashfn */ 190 scope6_init(); 191 addrsel_policy_init(); 192 nd6_init(); 193 frag6_init(); 194 /* 195 * in many cases, random() here does NOT return random number 196 * as initialization during bootstrap time occur in fixed order. 197 */ 198 microtime(&tv); 199 ip6_flow_seq = krandom() ^ tv.tv_usec; 200 microtime(&tv); 201 ip6_desync_factor = (krandom() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 202 } 203 204 static void 205 ip6_init2(void *dummy) 206 { 207 nd6_timer_init(); 208 in6_tmpaddrtimer_init(); 209 } 210 211 /* cheat */ 212 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 213 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 214 215 extern struct route_in6 ip6_forward_rt; 216 217 static void 218 ip6_input(netmsg_t msg) 219 { 220 struct mbuf *m = msg->packet.nm_packet; 221 struct ip6_hdr *ip6; 222 int off = sizeof(struct ip6_hdr), nest; 223 u_int32_t plen; 224 u_int32_t rtalert = ~0; 225 int nxt, ours = 0, rh_present = 0; 226 struct ifnet *deliverifp = NULL; 227 struct in6_addr odst; 228 int srcrt = 0; 229 230 #ifdef IPSEC 231 /* 232 * should the inner packet be considered authentic? 233 * see comment in ah4_input(). 234 */ 235 if (m) { 236 m->m_flags &= ~M_AUTHIPHDR; 237 m->m_flags &= ~M_AUTHIPDGM; 238 } 239 #endif 240 241 /* 242 * make sure we don't have onion peering information into m_aux. 243 */ 244 ip6_delaux(m); 245 246 /* 247 * mbuf statistics 248 */ 249 if (m->m_flags & M_EXT) { 250 if (m->m_next) 251 ip6stat.ip6s_mext2m++; 252 else 253 ip6stat.ip6s_mext1++; 254 } else { 255 #define M2MMAX NELEM(ip6stat.ip6s_m2m) 256 if (m->m_next) { 257 if (m->m_flags & M_LOOP) { 258 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 259 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 260 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 261 else 262 ip6stat.ip6s_m2m[0]++; 263 } else 264 ip6stat.ip6s_m1++; 265 #undef M2MMAX 266 } 267 268 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 269 ip6stat.ip6s_total++; 270 271 #ifndef PULLDOWN_TEST 272 /* 273 * L2 bridge code and some other code can return mbuf chain 274 * that does not conform to KAME requirement. too bad. 275 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 276 */ 277 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 278 struct mbuf *n; 279 280 n = m_getb(m->m_pkthdr.len, M_NOWAIT, MT_HEADER, M_PKTHDR); 281 if (n == NULL) 282 goto bad; 283 M_MOVE_PKTHDR(n, m); 284 285 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 286 n->m_len = n->m_pkthdr.len; 287 m_freem(m); 288 m = n; 289 } 290 IP6_EXTHDR_CHECK_VOIDRET(m, 0, sizeof(struct ip6_hdr)); 291 #endif 292 293 if (m->m_len < sizeof(struct ip6_hdr)) { 294 struct ifnet *inifp; 295 inifp = m->m_pkthdr.rcvif; 296 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 297 ip6stat.ip6s_toosmall++; 298 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 299 goto bad2; 300 } 301 } 302 303 ip6 = mtod(m, struct ip6_hdr *); 304 305 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 306 ip6stat.ip6s_badvers++; 307 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 308 goto bad; 309 } 310 311 /* 312 * Run through list of hooks for input packets. 313 * 314 * NB: Beware of the destination address changing 315 * (e.g. by NAT rewriting). When this happens, 316 * tell ip6_forward to do the right thing. 317 */ 318 if (pfil_has_hooks(&inet6_pfil_hook)) { 319 odst = ip6->ip6_dst; 320 if (pfil_run_hooks(&inet6_pfil_hook, &m, 321 m->m_pkthdr.rcvif, PFIL_IN)) { 322 goto bad2; 323 } 324 if (m == NULL) /* consumed by filter */ 325 goto bad2; 326 ip6 = mtod(m, struct ip6_hdr *); 327 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 328 } 329 330 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 331 332 #ifdef ALTQ 333 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 334 /* packet is dropped by traffic conditioner */ 335 return; 336 } 337 #endif 338 339 /* 340 * Check with the firewall... 341 */ 342 if (ip6_fw_enable && ip6_fw_chk_ptr) { 343 u_short port = 0; 344 /* If ipfw says divert, we have to just drop packet */ 345 /* use port as a dummy argument */ 346 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 347 m_freem(m); 348 m = NULL; 349 } 350 if (!m) 351 goto bad2; 352 } 353 354 /* 355 * Check against address spoofing/corruption. 356 */ 357 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 358 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 359 /* 360 * XXX: "badscope" is not very suitable for a multicast source. 361 */ 362 ip6stat.ip6s_badscope++; 363 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 364 goto bad; 365 } 366 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 367 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 368 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 369 ip6stat.ip6s_badscope++; 370 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 371 goto bad; 372 } 373 374 /* 375 * The following check is not documented in specs. A malicious 376 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 377 * and bypass security checks (act as if it was from 127.0.0.1 by using 378 * IPv6 src ::ffff:127.0.0.1). Be cautious. 379 * 380 * This check chokes if we are in an SIIT cloud. As none of BSDs 381 * support IPv4-less kernel compilation, we cannot support SIIT 382 * environment at all. So, it makes more sense for us to reject any 383 * malicious packets for non-SIIT environment, than try to do a 384 * partial support for SIIT environment. 385 */ 386 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 387 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 388 ip6stat.ip6s_badscope++; 389 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 390 goto bad; 391 } 392 #if 0 393 /* 394 * Reject packets with IPv4 compatible addresses (auto tunnel). 395 * 396 * The code forbids auto tunnel relay case in RFC1933 (the check is 397 * stronger than RFC1933). We may want to re-enable it if mech-xx 398 * is revised to forbid relaying case. 399 */ 400 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 401 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 402 ip6stat.ip6s_badscope++; 403 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 404 goto bad; 405 } 406 #endif 407 408 /* drop packets if interface ID portion is already filled */ 409 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 410 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 411 ip6->ip6_src.s6_addr16[1]) { 412 ip6stat.ip6s_badscope++; 413 goto bad; 414 } 415 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 416 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 417 ip6->ip6_dst.s6_addr16[1]) { 418 ip6stat.ip6s_badscope++; 419 goto bad; 420 } 421 } 422 423 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 424 ip6->ip6_src.s6_addr16[1] 425 = htons(m->m_pkthdr.rcvif->if_index); 426 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 427 ip6->ip6_dst.s6_addr16[1] 428 = htons(m->m_pkthdr.rcvif->if_index); 429 430 /* 431 * Multicast check 432 * 433 * WARNING! For general subnet proxying the interface hw will 434 * likely filter out the multicast solicitations, so 435 * the interface must be in promiscuous mode. 436 */ 437 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 438 ours = 1; 439 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 440 deliverifp = m->m_pkthdr.rcvif; 441 goto hbhcheck; 442 } 443 444 /* 445 * Unicast check 446 */ 447 if (ip6_forward_rt.ro_rt != NULL && 448 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) && 449 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 450 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) { 451 ip6stat.ip6s_forward_cachehit++; 452 } else { 453 struct sockaddr_in6 *dst6; 454 455 if (ip6_forward_rt.ro_rt) { 456 /* route is down or destination is different */ 457 ip6stat.ip6s_forward_cachemiss++; 458 RTFREE(ip6_forward_rt.ro_rt); 459 ip6_forward_rt.ro_rt = 0; 460 } 461 462 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 463 dst6 = &ip6_forward_rt.ro_dst; 464 dst6->sin6_len = sizeof(struct sockaddr_in6); 465 dst6->sin6_family = AF_INET6; 466 dst6->sin6_addr = ip6->ip6_dst; 467 468 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 469 } 470 471 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 472 473 /* 474 * Accept the packet if the forwarding interface to the destination 475 * according to the routing table is the loopback interface, 476 * unless the associated route has a gateway. 477 * Note that this approach causes to accept a packet if there is a 478 * route to the loopback interface for the destination of the packet. 479 * But we think it's even useful in some situations, e.g. when using 480 * a special daemon which wants to intercept the packet. 481 * 482 * XXX: some OSes automatically make a cloned route for the destination 483 * of an outgoing packet. If the outgoing interface of the packet 484 * is a loopback one, the kernel would consider the packet to be 485 * accepted, even if we have no such address assinged on the interface. 486 * We check the cloned flag of the route entry to reject such cases, 487 * assuming that route entries for our own addresses are not made by 488 * cloning (it should be true because in6_addloop explicitly installs 489 * the host route). However, we might have to do an explicit check 490 * while it would be less efficient. Or, should we rather install a 491 * reject route for such a case? 492 */ 493 if (ip6_forward_rt.ro_rt && 494 (ip6_forward_rt.ro_rt->rt_flags & 495 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 496 #ifdef RTF_WASCLONED 497 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 498 #endif 499 #ifdef RTF_CLONED 500 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 501 #endif 502 #if 0 503 /* 504 * The check below is redundant since the comparison of 505 * the destination and the key of the rtentry has 506 * already done through looking up the routing table. 507 */ 508 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 509 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 510 #endif 511 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 512 struct in6_ifaddr *ia6 = 513 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 514 515 /* 516 * record address information into m_aux. 517 */ 518 ip6_setdstifaddr(m, ia6); 519 520 /* 521 * packets to a tentative, duplicated, or somehow invalid 522 * address must not be accepted. 523 */ 524 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 525 /* this address is ready */ 526 ours = 1; 527 deliverifp = ia6->ia_ifp; /* correct? */ 528 /* Count the packet in the ip address stats */ 529 IFA_STAT_INC(&ia6->ia_ifa, ipackets, 1); 530 IFA_STAT_INC(&ia6->ia_ifa, ibytes, m->m_pkthdr.len); 531 goto hbhcheck; 532 } else { 533 /* address is not ready, so discard the packet. */ 534 nd6log((LOG_INFO, 535 "ip6_input: packet to an unready address %s->%s\n", 536 ip6_sprintf(&ip6->ip6_src), 537 ip6_sprintf(&ip6->ip6_dst))); 538 539 goto bad; 540 } 541 } 542 543 /* 544 * FAITH (Firewall Aided Internet Translator) 545 */ 546 if (ip6_keepfaith) { 547 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 548 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 549 /* XXX do we need more sanity checks? */ 550 ours = 1; 551 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 552 goto hbhcheck; 553 } 554 } 555 556 /* 557 * Now there is no reason to process the packet if it's not our own 558 * and we're not a router. 559 */ 560 if (!ip6_forwarding) { 561 ip6stat.ip6s_cantforward++; 562 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 563 goto bad; 564 } 565 566 hbhcheck: 567 /* 568 * record address information into m_aux, if we don't have one yet. 569 * note that we are unable to record it, if the address is not listed 570 * as our interface address (e.g. multicast addresses, addresses 571 * within FAITH prefixes and such). 572 */ 573 if (deliverifp && !ip6_getdstifaddr(m)) { 574 struct in6_ifaddr *ia6; 575 576 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 577 if (ia6) { 578 if (!ip6_setdstifaddr(m, ia6)) { 579 /* 580 * XXX maybe we should drop the packet here, 581 * as we could not provide enough information 582 * to the upper layers. 583 */ 584 } 585 } 586 } 587 588 /* 589 * Process Hop-by-Hop options header if it's contained. 590 * m may be modified in ip6_hopopts_input(). 591 * If a JumboPayload option is included, plen will also be modified. 592 */ 593 plen = (u_int32_t)ntohs(ip6->ip6_plen); 594 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 595 struct ip6_hbh *hbh; 596 597 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 598 #if 0 /*touches NULL pointer*/ 599 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 600 #endif 601 goto bad2; /* m have already been freed */ 602 } 603 604 /* adjust pointer */ 605 ip6 = mtod(m, struct ip6_hdr *); 606 607 /* 608 * if the payload length field is 0 and the next header field 609 * indicates Hop-by-Hop Options header, then a Jumbo Payload 610 * option MUST be included. 611 */ 612 if (ip6->ip6_plen == 0 && plen == 0) { 613 /* 614 * Note that if a valid jumbo payload option is 615 * contained, ip6_hoptops_input() must set a valid 616 * (non-zero) payload length to the variable plen. 617 */ 618 ip6stat.ip6s_badoptions++; 619 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 620 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 621 icmp6_error(m, ICMP6_PARAM_PROB, 622 ICMP6_PARAMPROB_HEADER, 623 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 624 goto bad2; 625 } 626 #ifndef PULLDOWN_TEST 627 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 628 hbh = (struct ip6_hbh *)(ip6 + 1); 629 #else 630 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 631 sizeof(struct ip6_hbh)); 632 if (hbh == NULL) { 633 ip6stat.ip6s_tooshort++; 634 goto bad2; 635 } 636 #endif 637 nxt = hbh->ip6h_nxt; 638 639 /* 640 * If we are acting as a router and the packet contains a 641 * router alert option, see if we know the option value. 642 * Currently, we only support the option value for MLD, in which 643 * case we should pass the packet to the multicast routing 644 * daemon. 645 */ 646 if (rtalert != ~0 && ip6_forwarding) { 647 switch (rtalert) { 648 case IP6OPT_RTALERT_MLD: 649 ours = 1; 650 break; 651 default: 652 /* 653 * RFC2711 requires unrecognized values must be 654 * silently ignored. 655 */ 656 break; 657 } 658 } 659 } else 660 nxt = ip6->ip6_nxt; 661 662 /* 663 * Check that the amount of data in the buffers 664 * is as at least much as the IPv6 header would have us expect. 665 * Trim mbufs if longer than we expect. 666 * Drop packet if shorter than we expect. 667 */ 668 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 669 ip6stat.ip6s_tooshort++; 670 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 671 goto bad; 672 } 673 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 674 if (m->m_len == m->m_pkthdr.len) { 675 m->m_len = sizeof(struct ip6_hdr) + plen; 676 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 677 } else 678 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 679 } 680 681 /* 682 * Forward if desirable. 683 */ 684 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 685 /* 686 * If we are acting as a multicast router, all 687 * incoming multicast packets are passed to the 688 * kernel-level multicast forwarding function. 689 * The packet is returned (relatively) intact; if 690 * ip6_mforward() returns a non-zero value, the packet 691 * must be discarded, else it may be accepted below. 692 */ 693 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 694 ip6stat.ip6s_cantforward++; 695 goto bad; 696 } 697 if (!ours) 698 goto bad; 699 } else if (!ours) { 700 ip6_forward(m, srcrt); 701 goto bad2; 702 } 703 704 ip6 = mtod(m, struct ip6_hdr *); 705 706 /* 707 * Malicious party may be able to use IPv4 mapped addr to confuse 708 * tcp/udp stack and bypass security checks (act as if it was from 709 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 710 * 711 * For SIIT end node behavior, you may want to disable the check. 712 * However, you will become vulnerable to attacks using IPv4 mapped 713 * source. 714 */ 715 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 716 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 717 ip6stat.ip6s_badscope++; 718 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 719 goto bad; 720 } 721 722 /* 723 * Tell launch routine the next header 724 */ 725 ip6stat.ip6s_delivered++; 726 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 727 nest = 0; 728 729 rh_present = 0; 730 while (nxt != IPPROTO_DONE) { 731 struct protosw *sw6; 732 733 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 734 ip6stat.ip6s_toomanyhdr++; 735 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 736 goto bad; 737 } 738 739 /* 740 * protection against faulty packet - there should be 741 * more sanity checks in header chain processing. 742 */ 743 if (m->m_pkthdr.len < off) { 744 ip6stat.ip6s_tooshort++; 745 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 746 goto bad; 747 } 748 749 #if 0 750 /* 751 * do we need to do it for every header? yeah, other 752 * functions can play with it (like re-allocate and copy). 753 */ 754 mhist = ip6_addaux(m); 755 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 756 hist = mtod(mhist, caddr_t) + mhist->m_len; 757 bcopy(&nxt, hist, sizeof(nxt)); 758 mhist->m_len += sizeof(nxt); 759 } else { 760 ip6stat.ip6s_toomanyhdr++; 761 goto bad; 762 } 763 #endif 764 765 if (nxt == IPPROTO_ROUTING) { 766 if (rh_present++) { 767 in6_ifstat_inc(m->m_pkthdr.rcvif, 768 ifs6_in_hdrerr); 769 ip6stat.ip6s_badoptions++; 770 goto bad; 771 } 772 } 773 774 sw6 = &inet6sw[ip6_protox[nxt]]; 775 #ifdef IPSEC 776 /* 777 * enforce IPsec policy checking if we are seeing last header. 778 * note that we do not visit this with protocols with pcb layer 779 * code - like udp/tcp/raw ip. 780 */ 781 if ((sw6->pr_flags & PR_LASTHDR) && ipsec6_in_reject(m, NULL)) { 782 ipsec6stat.in_polvio++; 783 goto bad; 784 } 785 #endif 786 /* 787 * If this is a terminal header forward to the port, otherwise 788 * process synchronously for more headers. 789 */ 790 if (sw6->pr_flags & PR_LASTHDR) { 791 struct netmsg_packet *pmsg; 792 lwkt_port_t port; 793 794 port = netisr_cpuport(0); /* XXX */ 795 if ((m->m_flags & M_HASH) == 0) 796 m_sethash(m, 0); /* XXX */ 797 798 KKASSERT(port != NULL); 799 pmsg = &m->m_hdr.mh_netmsg; 800 netmsg_init(&pmsg->base, NULL, 801 &netisr_apanic_rport, 802 0, transport6_processing_handler); 803 pmsg->nm_packet = m; 804 pmsg->nm_nxt = nxt; 805 pmsg->base.lmsg.u.ms_result = off; 806 lwkt_sendmsg(port, &pmsg->base.lmsg); 807 /* done with m */ 808 nxt = IPPROTO_DONE; 809 } else { 810 nxt = sw6->pr_input(&m, &off, nxt); 811 } 812 } 813 goto bad2; 814 bad: 815 m_freem(m); 816 bad2: 817 ; 818 /* msg was embedded in the mbuf, do not reply! */ 819 } 820 821 /* 822 * We have to call the pr_input() function from the correct protocol 823 * thread. The sw6->pr_soport() request at the end of ip6_input() 824 * returns the port and we forward a netmsg to the port to execute 825 * this function. 826 */ 827 static void 828 transport6_processing_handler(netmsg_t netmsg) 829 { 830 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg; 831 struct protosw *sw6; 832 int hlen; 833 int nxt; 834 835 sw6 = &inet6sw[ip6_protox[pmsg->nm_nxt]]; 836 hlen = pmsg->base.lmsg.u.ms_result; 837 838 nxt = sw6->pr_input(&pmsg->nm_packet, &hlen, pmsg->nm_nxt); 839 KKASSERT(nxt == IPPROTO_DONE); 840 /* netmsg was embedded in the mbuf, do not reply! */ 841 } 842 843 /* 844 * set/grab in6_ifaddr correspond to IPv6 destination address. 845 * XXX backward compatibility wrapper 846 */ 847 static struct ip6aux * 848 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 849 { 850 struct ip6aux *n; 851 852 n = ip6_addaux(m); 853 if (n) 854 n->ip6a_dstia6 = ia6; 855 return n; /* NULL if failed to set */ 856 } 857 858 struct in6_ifaddr * 859 ip6_getdstifaddr(struct mbuf *m) 860 { 861 struct ip6aux *n; 862 863 n = ip6_findaux(m); 864 if (n) 865 return n->ip6a_dstia6; 866 else 867 return NULL; 868 } 869 870 /* 871 * Hop-by-Hop options header processing. If a valid jumbo payload option is 872 * included, the real payload length will be stored in plenp. 873 */ 874 static int 875 ip6_hopopts_input(u_int32_t *plenp, 876 u_int32_t *rtalertp,/* XXX: should be stored more smart way */ 877 struct mbuf **mp, 878 int *offp) 879 { 880 struct mbuf *m = *mp; 881 int off = *offp, hbhlen; 882 struct ip6_hbh *hbh; 883 884 /* validation of the length of the header */ 885 #ifndef PULLDOWN_TEST 886 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 887 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 888 hbhlen = (hbh->ip6h_len + 1) << 3; 889 890 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 891 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 892 #else 893 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 894 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 895 if (hbh == NULL) { 896 ip6stat.ip6s_tooshort++; 897 return -1; 898 } 899 hbhlen = (hbh->ip6h_len + 1) << 3; 900 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 901 hbhlen); 902 if (hbh == NULL) { 903 ip6stat.ip6s_tooshort++; 904 return -1; 905 } 906 #endif 907 off += hbhlen; 908 hbhlen -= sizeof(struct ip6_hbh); 909 910 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 911 hbhlen, rtalertp, plenp) < 0) 912 return (-1); 913 914 *offp = off; 915 *mp = m; 916 return (0); 917 } 918 919 /* 920 * Search header for all Hop-by-hop options and process each option. 921 * This function is separate from ip6_hopopts_input() in order to 922 * handle a case where the sending node itself process its hop-by-hop 923 * options header. In such a case, the function is called from ip6_output(). 924 * 925 * The function assumes that hbh header is located right after the IPv6 header 926 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 927 * opthead + hbhlen is located in continuous memory region. 928 */ 929 int 930 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 931 u_int32_t *rtalertp, 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_RTALERT: 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(u_int8_t *optp, struct mbuf *m, int off) 1064 { 1065 struct ip6_hdr *ip6; 1066 1067 switch (IP6OPT_TYPE(*optp)) { 1068 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1069 return ((int)*(optp + 1)); 1070 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1071 m_freem(m); 1072 return (-1); 1073 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1074 ip6stat.ip6s_badoptions++; 1075 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1076 return (-1); 1077 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1078 ip6stat.ip6s_badoptions++; 1079 ip6 = mtod(m, struct ip6_hdr *); 1080 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1081 (m->m_flags & (M_BCAST|M_MCAST))) 1082 m_freem(m); 1083 else 1084 icmp6_error(m, ICMP6_PARAM_PROB, 1085 ICMP6_PARAMPROB_OPTION, off); 1086 return (-1); 1087 } 1088 1089 m_freem(m); /* XXX: NOTREACHED */ 1090 return (-1); 1091 } 1092 1093 /* 1094 * Create the "control" list for this pcb. 1095 * The function will not modify mbuf chain at all. 1096 * 1097 * with KAME mbuf chain restriction: 1098 * The routine will be called from upper layer handlers like tcp6_input(). 1099 * Thus the routine assumes that the caller (tcp6_input) have already 1100 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1101 * very first mbuf on the mbuf chain. 1102 */ 1103 void 1104 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6, 1105 struct mbuf *m) 1106 { 1107 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1108 struct thread *td = curthread; /* XXX */ 1109 int privileged = 0; 1110 1111 1112 if (priv_check(td, PRIV_ROOT) == 0) 1113 privileged++; 1114 1115 #ifdef SO_TIMESTAMP 1116 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1117 struct timeval tv; 1118 1119 microtime(&tv); 1120 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv), 1121 SCM_TIMESTAMP, SOL_SOCKET); 1122 if (*mp) { 1123 mp = &(*mp)->m_next; 1124 } 1125 } 1126 #endif 1127 1128 /* RFC 2292 sec. 5 */ 1129 if (in6p->in6p_flags & IN6P_PKTINFO) { 1130 struct in6_pktinfo pi6; 1131 1132 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1133 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1134 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) ? 1135 m->m_pkthdr.rcvif->if_index : 0; 1136 *mp = sbcreatecontrol((caddr_t)&pi6, sizeof(struct in6_pktinfo), 1137 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1138 if (*mp) 1139 mp = &(*mp)->m_next; 1140 } 1141 1142 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1143 int hlim = ip6->ip6_hlim & 0xff; 1144 1145 *mp = sbcreatecontrol((caddr_t)&hlim, sizeof(int), 1146 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1147 if (*mp) 1148 mp = &(*mp)->m_next; 1149 } 1150 1151 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1152 u_int32_t flowinfo; 1153 int tclass; 1154 1155 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1156 flowinfo >>= 20; 1157 1158 tclass = flowinfo & 0xff; 1159 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1160 IPV6_TCLASS, IPPROTO_IPV6); 1161 if (*mp) 1162 mp = &(*mp)->m_next; 1163 } 1164 1165 /* 1166 * IPV6_HOPOPTS socket option. We require super-user privilege 1167 * for the option, but it might be too strict, since there might 1168 * be some hop-by-hop options which can be returned to normal user. 1169 * See RFC 2292 section 6. 1170 */ 1171 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1172 /* 1173 * Check if a hop-by-hop options header is contatined in the 1174 * received packet, and if so, store the options as ancillary 1175 * data. Note that a hop-by-hop options header must be 1176 * just after the IPv6 header, which is assured through the 1177 * IPv6 input processing. 1178 */ 1179 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1180 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1181 struct ip6_hbh *hbh; 1182 int hbhlen = 0; 1183 #ifdef PULLDOWN_TEST 1184 struct mbuf *ext; 1185 #endif 1186 1187 #ifndef PULLDOWN_TEST 1188 hbh = (struct ip6_hbh *)(ip6 + 1); 1189 hbhlen = (hbh->ip6h_len + 1) << 3; 1190 #else 1191 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1192 ip6->ip6_nxt); 1193 if (ext == NULL) { 1194 ip6stat.ip6s_tooshort++; 1195 return; 1196 } 1197 hbh = mtod(ext, struct ip6_hbh *); 1198 hbhlen = (hbh->ip6h_len + 1) << 3; 1199 if (hbhlen != ext->m_len) { 1200 m_freem(ext); 1201 ip6stat.ip6s_tooshort++; 1202 return; 1203 } 1204 #endif 1205 1206 /* 1207 * XXX: We copy the whole header even if a 1208 * jumbo payload option is included, the option which 1209 * is to be removed before returning according to 1210 * RFC 2292. 1211 * Note: this constraint is removed in 2292bis. 1212 */ 1213 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1214 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1215 IPPROTO_IPV6); 1216 if (*mp) 1217 mp = &(*mp)->m_next; 1218 #ifdef PULLDOWN_TEST 1219 m_freem(ext); 1220 #endif 1221 } 1222 } 1223 1224 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1225 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1226 int proto, off, nxt; 1227 1228 /* 1229 * go through the header chain to see if a routing header is 1230 * contained in the packet. We need this information to store 1231 * destination options headers (if any) properly. 1232 * XXX: performance issue. We should record this info when 1233 * processing extension headers in incoming routine. 1234 * (todo) use m_aux? 1235 */ 1236 proto = IPPROTO_IPV6; 1237 off = 0; 1238 nxt = -1; 1239 while (1) { 1240 int newoff; 1241 1242 newoff = ip6_nexthdr(m, off, proto, &nxt); 1243 if (newoff < 0) 1244 break; 1245 if (newoff < off) /* invalid, check for safety */ 1246 break; 1247 if ((proto = nxt) == IPPROTO_ROUTING) 1248 break; 1249 off = newoff; 1250 } 1251 } 1252 1253 if ((in6p->in6p_flags & 1254 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1255 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1256 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1257 1258 /* 1259 * Search for destination options headers or routing 1260 * header(s) through the header chain, and stores each 1261 * header as ancillary data. 1262 * Note that the order of the headers remains in 1263 * the chain of ancillary data. 1264 */ 1265 while (1) { /* is explicit loop prevention necessary? */ 1266 struct ip6_ext *ip6e = NULL; 1267 int elen; 1268 #ifdef PULLDOWN_TEST 1269 struct mbuf *ext = NULL; 1270 #endif 1271 1272 /* 1273 * if it is not an extension header, don't try to 1274 * pull it from the chain. 1275 */ 1276 switch (nxt) { 1277 case IPPROTO_DSTOPTS: 1278 case IPPROTO_ROUTING: 1279 case IPPROTO_HOPOPTS: 1280 case IPPROTO_AH: /* is it possible? */ 1281 break; 1282 default: 1283 goto loopend; 1284 } 1285 1286 #ifndef PULLDOWN_TEST 1287 if (off + sizeof(*ip6e) > m->m_len) 1288 goto loopend; 1289 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1290 if (nxt == IPPROTO_AH) 1291 elen = (ip6e->ip6e_len + 2) << 2; 1292 else 1293 elen = (ip6e->ip6e_len + 1) << 3; 1294 if (off + elen > m->m_len) 1295 goto loopend; 1296 #else 1297 ext = ip6_pullexthdr(m, off, nxt); 1298 if (ext == NULL) { 1299 ip6stat.ip6s_tooshort++; 1300 return; 1301 } 1302 ip6e = mtod(ext, struct ip6_ext *); 1303 if (nxt == IPPROTO_AH) 1304 elen = (ip6e->ip6e_len + 2) << 2; 1305 else 1306 elen = (ip6e->ip6e_len + 1) << 3; 1307 if (elen != ext->m_len) { 1308 m_freem(ext); 1309 ip6stat.ip6s_tooshort++; 1310 return; 1311 } 1312 #endif 1313 1314 switch (nxt) { 1315 case IPPROTO_DSTOPTS: 1316 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1317 break; 1318 1319 /* 1320 * We also require super-user privilege for 1321 * the option. See comments on IN6_HOPOPTS. 1322 */ 1323 if (!privileged) 1324 break; 1325 1326 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1327 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1328 IPPROTO_IPV6); 1329 if (*mp) 1330 mp = &(*mp)->m_next; 1331 break; 1332 case IPPROTO_ROUTING: 1333 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1334 break; 1335 1336 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1337 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1338 IPPROTO_IPV6); 1339 if (*mp) 1340 mp = &(*mp)->m_next; 1341 break; 1342 case IPPROTO_HOPOPTS: 1343 case IPPROTO_AH: /* is it possible? */ 1344 break; 1345 1346 default: 1347 /* 1348 * other cases have been filtered in the above. 1349 * none will visit this case. here we supply 1350 * the code just in case (nxt overwritten or 1351 * other cases). 1352 */ 1353 #ifdef PULLDOWN_TEST 1354 m_freem(ext); 1355 #endif 1356 goto loopend; 1357 1358 } 1359 1360 /* proceed with the next header. */ 1361 off += elen; 1362 nxt = ip6e->ip6e_nxt; 1363 ip6e = NULL; 1364 #ifdef PULLDOWN_TEST 1365 m_freem(ext); 1366 ext = NULL; 1367 #endif 1368 } 1369 loopend: 1370 ; 1371 } 1372 #undef IS2292 1373 } 1374 1375 void 1376 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1377 { 1378 struct socket *so; 1379 struct mbuf *m_mtu; 1380 struct ip6_mtuinfo mtuctl; 1381 1382 so = in6p->inp_socket; 1383 1384 if (mtu == NULL) 1385 return; 1386 1387 #ifdef DIAGNOSTIC 1388 if (so == NULL) /* I believe this is impossible */ 1389 panic("ip6_notify_pmtu: socket is NULL"); 1390 #endif 1391 1392 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1393 mtuctl.ip6m_mtu = *mtu; 1394 mtuctl.ip6m_addr = *dst; 1395 1396 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1397 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1398 return; 1399 1400 lwkt_gettoken(&so->so_rcv.ssb_token); 1401 if (sbappendaddr(&so->so_rcv.sb, (struct sockaddr *)dst, NULL, m_mtu) 1402 == 0) { 1403 m_freem(m_mtu); 1404 /* XXX: should count statistics */ 1405 } else { 1406 sorwakeup(so); 1407 } 1408 lwkt_reltoken(&so->so_rcv.ssb_token); 1409 } 1410 1411 #ifdef PULLDOWN_TEST 1412 /* 1413 * pull single extension header from mbuf chain. returns single mbuf that 1414 * contains the result, or NULL on error. 1415 */ 1416 static struct mbuf * 1417 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1418 { 1419 struct ip6_ext ip6e; 1420 size_t elen; 1421 struct mbuf *n; 1422 1423 #ifdef DIAGNOSTIC 1424 switch (nxt) { 1425 case IPPROTO_DSTOPTS: 1426 case IPPROTO_ROUTING: 1427 case IPPROTO_HOPOPTS: 1428 case IPPROTO_AH: /* is it possible? */ 1429 break; 1430 default: 1431 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1432 } 1433 #endif 1434 1435 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1436 if (nxt == IPPROTO_AH) 1437 elen = (ip6e.ip6e_len + 2) << 2; 1438 else 1439 elen = (ip6e.ip6e_len + 1) << 3; 1440 1441 n = m_getb(elen, M_NOWAIT, MT_DATA, 0); 1442 if (n == NULL) 1443 return NULL; 1444 n->m_len = 0; 1445 1446 if (elen >= M_TRAILINGSPACE(n)) { 1447 m_free(n); 1448 return NULL; 1449 } 1450 1451 m_copydata(m, off, elen, mtod(n, caddr_t)); 1452 n->m_len = elen; 1453 return n; 1454 } 1455 #endif 1456 1457 /* 1458 * Get pointer to the previous header followed by the header 1459 * currently processed. 1460 * XXX: This function supposes that 1461 * M includes all headers, 1462 * the next header field and the header length field of each header 1463 * are valid, and 1464 * the sum of each header length equals to OFF. 1465 * Because of these assumptions, this function must be called very 1466 * carefully. Moreover, it will not be used in the near future when 1467 * we develop `neater' mechanism to process extension headers. 1468 */ 1469 char * 1470 ip6_get_prevhdr(struct mbuf *m, int off) 1471 { 1472 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1473 1474 if (off == sizeof(struct ip6_hdr)) 1475 return (&ip6->ip6_nxt); 1476 else { 1477 int len, nxt; 1478 struct ip6_ext *ip6e = NULL; 1479 1480 nxt = ip6->ip6_nxt; 1481 len = sizeof(struct ip6_hdr); 1482 while (len < off) { 1483 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1484 1485 switch (nxt) { 1486 case IPPROTO_FRAGMENT: 1487 len += sizeof(struct ip6_frag); 1488 break; 1489 case IPPROTO_AH: 1490 len += (ip6e->ip6e_len + 2) << 2; 1491 break; 1492 default: 1493 len += (ip6e->ip6e_len + 1) << 3; 1494 break; 1495 } 1496 nxt = ip6e->ip6e_nxt; 1497 } 1498 if (ip6e) 1499 return (&ip6e->ip6e_nxt); 1500 else 1501 return NULL; 1502 } 1503 } 1504 1505 /* 1506 * get next header offset. m will be retained. 1507 */ 1508 int 1509 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1510 { 1511 struct ip6_hdr ip6; 1512 struct ip6_ext ip6e; 1513 struct ip6_frag fh; 1514 1515 /* just in case */ 1516 if (m == NULL) 1517 panic("ip6_nexthdr: m == NULL"); 1518 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1519 return -1; 1520 1521 switch (proto) { 1522 case IPPROTO_IPV6: 1523 if (m->m_pkthdr.len < off + sizeof(ip6)) 1524 return -1; 1525 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1526 if (nxtp) 1527 *nxtp = ip6.ip6_nxt; 1528 off += sizeof(ip6); 1529 return off; 1530 1531 case IPPROTO_FRAGMENT: 1532 /* 1533 * terminate parsing if it is not the first fragment, 1534 * it does not make sense to parse through it. 1535 */ 1536 if (m->m_pkthdr.len < off + sizeof(fh)) 1537 return -1; 1538 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1539 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1540 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1541 return -1; 1542 if (nxtp) 1543 *nxtp = fh.ip6f_nxt; 1544 off += sizeof(struct ip6_frag); 1545 return off; 1546 1547 case IPPROTO_AH: 1548 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1549 return -1; 1550 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1551 if (nxtp) 1552 *nxtp = ip6e.ip6e_nxt; 1553 off += (ip6e.ip6e_len + 2) << 2; 1554 return off; 1555 1556 case IPPROTO_HOPOPTS: 1557 case IPPROTO_ROUTING: 1558 case IPPROTO_DSTOPTS: 1559 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1560 return -1; 1561 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1562 if (nxtp) 1563 *nxtp = ip6e.ip6e_nxt; 1564 off += (ip6e.ip6e_len + 1) << 3; 1565 return off; 1566 1567 case IPPROTO_NONE: 1568 case IPPROTO_ESP: 1569 case IPPROTO_IPCOMP: 1570 /* give up */ 1571 return -1; 1572 1573 default: 1574 return -1; 1575 } 1576 1577 return -1; 1578 } 1579 1580 /* 1581 * get offset for the last header in the chain. m will be kept untainted. 1582 */ 1583 int 1584 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1585 { 1586 int newoff; 1587 int nxt; 1588 1589 if (!nxtp) { 1590 nxt = -1; 1591 nxtp = &nxt; 1592 } 1593 while (1) { 1594 newoff = ip6_nexthdr(m, off, proto, nxtp); 1595 if (newoff < 0) 1596 return off; 1597 else if (newoff < off) 1598 return -1; /* invalid */ 1599 else if (newoff == off) 1600 return newoff; 1601 1602 off = newoff; 1603 proto = *nxtp; 1604 } 1605 } 1606 1607 struct ip6aux * 1608 ip6_addaux(struct mbuf *m) 1609 { 1610 struct m_tag *mtag; 1611 1612 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1613 if (!mtag) { 1614 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1615 M_NOWAIT); 1616 if (mtag) 1617 m_tag_prepend(m, mtag); 1618 } 1619 if (mtag) 1620 bzero(m_tag_data(mtag), sizeof(struct ip6aux)); 1621 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1622 } 1623 1624 struct ip6aux * 1625 ip6_findaux(struct mbuf *m) 1626 { 1627 struct m_tag *mtag; 1628 1629 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1630 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1631 } 1632 1633 void 1634 ip6_delaux(struct mbuf *m) 1635 { 1636 struct m_tag *mtag; 1637 1638 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1639 if (mtag) 1640 m_tag_delete(m, mtag); 1641 } 1642 1643 /* 1644 * System control for IP6 1645 */ 1646 1647 u_char inet6ctlerrmap[PRC_NCMDS] = { 1648 0, 0, 0, 0, 1649 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1650 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1651 EMSGSIZE, EHOSTUNREACH, 0, 0, 1652 0, 0, 0, 0, 1653 ENOPROTOOPT 1654 }; 1655