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 callout_init(&nd6_timer_ch); 209 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 210 211 in6_tmpaddrtimer_init(); 212 } 213 214 /* cheat */ 215 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 216 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 217 218 extern struct route_in6 ip6_forward_rt; 219 220 static 221 void 222 ip6_input(netmsg_t msg) 223 { 224 struct mbuf *m = msg->packet.nm_packet; 225 struct ip6_hdr *ip6; 226 int off = sizeof(struct ip6_hdr), nest; 227 u_int32_t plen; 228 u_int32_t rtalert = ~0; 229 int nxt, ours = 0, rh_present = 0; 230 struct ifnet *deliverifp = NULL; 231 struct in6_addr odst; 232 int srcrt = 0; 233 234 #ifdef IPSEC 235 /* 236 * should the inner packet be considered authentic? 237 * see comment in ah4_input(). 238 */ 239 if (m) { 240 m->m_flags &= ~M_AUTHIPHDR; 241 m->m_flags &= ~M_AUTHIPDGM; 242 } 243 #endif 244 245 /* 246 * make sure we don't have onion peering information into m_aux. 247 */ 248 ip6_delaux(m); 249 250 /* 251 * mbuf statistics 252 */ 253 if (m->m_flags & M_EXT) { 254 if (m->m_next) 255 ip6stat.ip6s_mext2m++; 256 else 257 ip6stat.ip6s_mext1++; 258 } else { 259 #define M2MMAX NELEM(ip6stat.ip6s_m2m) 260 if (m->m_next) { 261 if (m->m_flags & M_LOOP) { 262 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 263 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 264 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 265 else 266 ip6stat.ip6s_m2m[0]++; 267 } else 268 ip6stat.ip6s_m1++; 269 #undef M2MMAX 270 } 271 272 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 273 ip6stat.ip6s_total++; 274 275 #ifndef PULLDOWN_TEST 276 /* 277 * L2 bridge code and some other code can return mbuf chain 278 * that does not conform to KAME requirement. too bad. 279 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 280 */ 281 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 282 struct mbuf *n; 283 284 n = m_getb(m->m_pkthdr.len, MB_DONTWAIT, MT_HEADER, M_PKTHDR); 285 if (n == NULL) 286 goto bad; 287 M_MOVE_PKTHDR(n, m); 288 289 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 290 n->m_len = n->m_pkthdr.len; 291 m_freem(m); 292 m = n; 293 } 294 IP6_EXTHDR_CHECK_VOIDRET(m, 0, sizeof(struct ip6_hdr)); 295 #endif 296 297 if (m->m_len < sizeof(struct ip6_hdr)) { 298 struct ifnet *inifp; 299 inifp = m->m_pkthdr.rcvif; 300 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 301 ip6stat.ip6s_toosmall++; 302 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 303 goto bad2; 304 } 305 } 306 307 ip6 = mtod(m, struct ip6_hdr *); 308 309 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 310 ip6stat.ip6s_badvers++; 311 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 312 goto bad; 313 } 314 315 /* 316 * Run through list of hooks for input packets. 317 * 318 * NB: Beware of the destination address changing 319 * (e.g. by NAT rewriting). When this happens, 320 * tell ip6_forward to do the right thing. 321 */ 322 if (pfil_has_hooks(&inet6_pfil_hook)) { 323 odst = ip6->ip6_dst; 324 if (pfil_run_hooks(&inet6_pfil_hook, &m, 325 m->m_pkthdr.rcvif, PFIL_IN)) { 326 goto bad2; 327 } 328 if (m == NULL) /* consumed by filter */ 329 goto bad2; 330 ip6 = mtod(m, struct ip6_hdr *); 331 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 332 } 333 334 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 335 336 #ifdef ALTQ 337 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 338 /* packet is dropped by traffic conditioner */ 339 return; 340 } 341 #endif 342 343 /* 344 * Check with the firewall... 345 */ 346 if (ip6_fw_enable && ip6_fw_chk_ptr) { 347 u_short port = 0; 348 /* If ipfw says divert, we have to just drop packet */ 349 /* use port as a dummy argument */ 350 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 351 m_freem(m); 352 m = NULL; 353 } 354 if (!m) 355 goto bad2; 356 } 357 358 /* 359 * Check against address spoofing/corruption. 360 */ 361 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 362 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 363 /* 364 * XXX: "badscope" is not very suitable for a multicast source. 365 */ 366 ip6stat.ip6s_badscope++; 367 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 368 goto bad; 369 } 370 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 371 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 372 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 373 ip6stat.ip6s_badscope++; 374 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 375 goto bad; 376 } 377 378 /* 379 * The following check is not documented in specs. A malicious 380 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 381 * and bypass security checks (act as if it was from 127.0.0.1 by using 382 * IPv6 src ::ffff:127.0.0.1). Be cautious. 383 * 384 * This check chokes if we are in an SIIT cloud. As none of BSDs 385 * support IPv4-less kernel compilation, we cannot support SIIT 386 * environment at all. So, it makes more sense for us to reject any 387 * malicious packets for non-SIIT environment, than try to do a 388 * partical support for SIIT environment. 389 */ 390 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 391 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 392 ip6stat.ip6s_badscope++; 393 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 394 goto bad; 395 } 396 #if 0 397 /* 398 * Reject packets with IPv4 compatible addresses (auto tunnel). 399 * 400 * The code forbids auto tunnel relay case in RFC1933 (the check is 401 * stronger than RFC1933). We may want to re-enable it if mech-xx 402 * is revised to forbid relaying case. 403 */ 404 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 405 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 406 ip6stat.ip6s_badscope++; 407 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 408 goto bad; 409 } 410 #endif 411 412 /* drop packets if interface ID portion is already filled */ 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_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 420 ip6->ip6_dst.s6_addr16[1]) { 421 ip6stat.ip6s_badscope++; 422 goto bad; 423 } 424 } 425 426 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 427 ip6->ip6_src.s6_addr16[1] 428 = htons(m->m_pkthdr.rcvif->if_index); 429 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 430 ip6->ip6_dst.s6_addr16[1] 431 = htons(m->m_pkthdr.rcvif->if_index); 432 433 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 434 /* 435 * We use rt->rt_ifp to determine if the address is ours or not. 436 * If rt_ifp is lo0, the address is ours. 437 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 438 * so any address under fe80::%lo0/64 will be mistakenly considered 439 * local. The special case is supplied to handle the case properly 440 * by actually looking at interface addresses 441 * (using in6ifa_ifpwithaddr). 442 */ 443 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) && 444 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 445 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 446 icmp6_error(m, ICMP6_DST_UNREACH, 447 ICMP6_DST_UNREACH_ADDR, 0); 448 /* m is already freed */ 449 goto bad2; 450 } 451 452 ours = 1; 453 deliverifp = m->m_pkthdr.rcvif; 454 goto hbhcheck; 455 } 456 #endif 457 458 /* 459 * Multicast check 460 * 461 * WARNING! For general subnet proxying the interface hw will 462 * likely filter out the multicast solicitations, so 463 * the interface must be in promiscuous mode. 464 */ 465 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 466 ours = 1; 467 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 468 deliverifp = m->m_pkthdr.rcvif; 469 goto hbhcheck; 470 } 471 472 /* 473 * Unicast check 474 */ 475 switch (ip6_ours_check_algorithm) { 476 default: 477 /* 478 * XXX: I intentionally broke our indentation rule here, 479 * since this switch-case is just for measurement and 480 * therefore should soon be removed. 481 */ 482 if (ip6_forward_rt.ro_rt != NULL && 483 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) && 484 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 485 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 486 ip6stat.ip6s_forward_cachehit++; 487 else { 488 struct sockaddr_in6 *dst6; 489 490 if (ip6_forward_rt.ro_rt) { 491 /* route is down or destination is different */ 492 ip6stat.ip6s_forward_cachemiss++; 493 RTFREE(ip6_forward_rt.ro_rt); 494 ip6_forward_rt.ro_rt = 0; 495 } 496 497 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 498 dst6 = &ip6_forward_rt.ro_dst; 499 dst6->sin6_len = sizeof(struct sockaddr_in6); 500 dst6->sin6_family = AF_INET6; 501 dst6->sin6_addr = ip6->ip6_dst; 502 503 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 504 } 505 506 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 507 508 /* 509 * Accept the packet if the forwarding interface to the destination 510 * according to the routing table is the loopback interface, 511 * unless the associated route has a gateway. 512 * Note that this approach causes to accept a packet if there is a 513 * route to the loopback interface for the destination of the packet. 514 * But we think it's even useful in some situations, e.g. when using 515 * a special daemon which wants to intercept the packet. 516 * 517 * XXX: some OSes automatically make a cloned route for the destination 518 * of an outgoing packet. If the outgoing interface of the packet 519 * is a loopback one, the kernel would consider the packet to be 520 * accepted, even if we have no such address assinged on the interface. 521 * We check the cloned flag of the route entry to reject such cases, 522 * assuming that route entries for our own addresses are not made by 523 * cloning (it should be true because in6_addloop explicitly installs 524 * the host route). However, we might have to do an explicit check 525 * while it would be less efficient. Or, should we rather install a 526 * reject route for such a case? 527 */ 528 if (ip6_forward_rt.ro_rt && 529 (ip6_forward_rt.ro_rt->rt_flags & 530 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 531 #ifdef RTF_WASCLONED 532 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 533 #endif 534 #ifdef RTF_CLONED 535 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 536 #endif 537 #if 0 538 /* 539 * The check below is redundant since the comparison of 540 * the destination and the key of the rtentry has 541 * already done through looking up the routing table. 542 */ 543 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 544 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 545 #endif 546 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 547 struct in6_ifaddr *ia6 = 548 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 549 550 /* 551 * record address information into m_aux. 552 */ 553 ip6_setdstifaddr(m, ia6); 554 555 /* 556 * packets to a tentative, duplicated, or somehow invalid 557 * address must not be accepted. 558 */ 559 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 560 /* this address is ready */ 561 ours = 1; 562 deliverifp = ia6->ia_ifp; /* correct? */ 563 /* Count the packet in the ip address stats */ 564 IFA_STAT_INC(&ia6->ia_ifa, ipackets, 1); 565 IFA_STAT_INC(&ia6->ia_ifa, ibytes, m->m_pkthdr.len); 566 goto hbhcheck; 567 } else { 568 /* address is not ready, so discard the packet. */ 569 nd6log((LOG_INFO, 570 "ip6_input: packet to an unready address %s->%s\n", 571 ip6_sprintf(&ip6->ip6_src), 572 ip6_sprintf(&ip6->ip6_dst))); 573 574 goto bad; 575 } 576 } 577 } /* XXX indentation (see above) */ 578 579 /* 580 * FAITH(Firewall Aided Internet Translator) 581 */ 582 if (ip6_keepfaith) { 583 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 584 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 585 /* XXX do we need more sanity checks? */ 586 ours = 1; 587 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 588 goto hbhcheck; 589 } 590 } 591 592 /* 593 * Now there is no reason to process the packet if it's not our own 594 * and we're not a router. 595 */ 596 if (!ip6_forwarding) { 597 ip6stat.ip6s_cantforward++; 598 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 599 goto bad; 600 } 601 602 hbhcheck: 603 /* 604 * record address information into m_aux, if we don't have one yet. 605 * note that we are unable to record it, if the address is not listed 606 * as our interface address (e.g. multicast addresses, addresses 607 * within FAITH prefixes and such). 608 */ 609 if (deliverifp && !ip6_getdstifaddr(m)) { 610 struct in6_ifaddr *ia6; 611 612 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 613 if (ia6) { 614 if (!ip6_setdstifaddr(m, ia6)) { 615 /* 616 * XXX maybe we should drop the packet here, 617 * as we could not provide enough information 618 * to the upper layers. 619 */ 620 } 621 } 622 } 623 624 /* 625 * Process Hop-by-Hop options header if it's contained. 626 * m may be modified in ip6_hopopts_input(). 627 * If a JumboPayload option is included, plen will also be modified. 628 */ 629 plen = (u_int32_t)ntohs(ip6->ip6_plen); 630 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 631 struct ip6_hbh *hbh; 632 633 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 634 #if 0 /*touches NULL pointer*/ 635 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 636 #endif 637 goto bad2; /* m have already been freed */ 638 } 639 640 /* adjust pointer */ 641 ip6 = mtod(m, struct ip6_hdr *); 642 643 /* 644 * if the payload length field is 0 and the next header field 645 * indicates Hop-by-Hop Options header, then a Jumbo Payload 646 * option MUST be included. 647 */ 648 if (ip6->ip6_plen == 0 && plen == 0) { 649 /* 650 * Note that if a valid jumbo payload option is 651 * contained, ip6_hoptops_input() must set a valid 652 * (non-zero) payload length to the variable plen. 653 */ 654 ip6stat.ip6s_badoptions++; 655 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 656 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 657 icmp6_error(m, ICMP6_PARAM_PROB, 658 ICMP6_PARAMPROB_HEADER, 659 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 660 goto bad2; 661 } 662 #ifndef PULLDOWN_TEST 663 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 664 hbh = (struct ip6_hbh *)(ip6 + 1); 665 #else 666 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 667 sizeof(struct ip6_hbh)); 668 if (hbh == NULL) { 669 ip6stat.ip6s_tooshort++; 670 goto bad2; 671 } 672 #endif 673 nxt = hbh->ip6h_nxt; 674 675 /* 676 * If we are acting as a router and the packet contains a 677 * router alert option, see if we know the option value. 678 * Currently, we only support the option value for MLD, in which 679 * case we should pass the packet to the multicast routing 680 * daemon. 681 */ 682 if (rtalert != ~0 && ip6_forwarding) { 683 switch (rtalert) { 684 case IP6OPT_RTALERT_MLD: 685 ours = 1; 686 break; 687 default: 688 /* 689 * RFC2711 requires unrecognized values must be 690 * silently ignored. 691 */ 692 break; 693 } 694 } 695 } else 696 nxt = ip6->ip6_nxt; 697 698 /* 699 * Check that the amount of data in the buffers 700 * is as at least much as the IPv6 header would have us expect. 701 * Trim mbufs if longer than we expect. 702 * Drop packet if shorter than we expect. 703 */ 704 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 705 ip6stat.ip6s_tooshort++; 706 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 707 goto bad; 708 } 709 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 710 if (m->m_len == m->m_pkthdr.len) { 711 m->m_len = sizeof(struct ip6_hdr) + plen; 712 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 713 } else 714 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 715 } 716 717 /* 718 * Forward if desirable. 719 */ 720 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 721 /* 722 * If we are acting as a multicast router, all 723 * incoming multicast packets are passed to the 724 * kernel-level multicast forwarding function. 725 * The packet is returned (relatively) intact; if 726 * ip6_mforward() returns a non-zero value, the packet 727 * must be discarded, else it may be accepted below. 728 */ 729 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 730 ip6stat.ip6s_cantforward++; 731 goto bad; 732 } 733 if (!ours) 734 goto bad; 735 } else if (!ours) { 736 ip6_forward(m, srcrt); 737 goto bad2; 738 } 739 740 ip6 = mtod(m, struct ip6_hdr *); 741 742 /* 743 * Malicious party may be able to use IPv4 mapped addr to confuse 744 * tcp/udp stack and bypass security checks (act as if it was from 745 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 746 * 747 * For SIIT end node behavior, you may want to disable the check. 748 * However, you will become vulnerable to attacks using IPv4 mapped 749 * source. 750 */ 751 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 752 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 753 ip6stat.ip6s_badscope++; 754 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 755 goto bad; 756 } 757 758 /* 759 * Tell launch routine the next header 760 */ 761 ip6stat.ip6s_delivered++; 762 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 763 nest = 0; 764 765 rh_present = 0; 766 while (nxt != IPPROTO_DONE) { 767 struct protosw *sw6; 768 769 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 770 ip6stat.ip6s_toomanyhdr++; 771 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 772 goto bad; 773 } 774 775 /* 776 * protection against faulty packet - there should be 777 * more sanity checks in header chain processing. 778 */ 779 if (m->m_pkthdr.len < off) { 780 ip6stat.ip6s_tooshort++; 781 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 782 goto bad; 783 } 784 785 #if 0 786 /* 787 * do we need to do it for every header? yeah, other 788 * functions can play with it (like re-allocate and copy). 789 */ 790 mhist = ip6_addaux(m); 791 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 792 hist = mtod(mhist, caddr_t) + mhist->m_len; 793 bcopy(&nxt, hist, sizeof(nxt)); 794 mhist->m_len += sizeof(nxt); 795 } else { 796 ip6stat.ip6s_toomanyhdr++; 797 goto bad; 798 } 799 #endif 800 801 if (nxt == IPPROTO_ROUTING) { 802 if (rh_present++) { 803 in6_ifstat_inc(m->m_pkthdr.rcvif, 804 ifs6_in_hdrerr); 805 ip6stat.ip6s_badoptions++; 806 goto bad; 807 } 808 } 809 810 sw6 = &inet6sw[ip6_protox[nxt]]; 811 #ifdef IPSEC 812 /* 813 * enforce IPsec policy checking if we are seeing last header. 814 * note that we do not visit this with protocols with pcb layer 815 * code - like udp/tcp/raw ip. 816 */ 817 if ((sw6->pr_flags & PR_LASTHDR) && ipsec6_in_reject(m, NULL)) { 818 ipsec6stat.in_polvio++; 819 goto bad; 820 } 821 #endif 822 /* 823 * If this is a terminal header forward to the port, otherwise 824 * process synchronously for more headers. 825 */ 826 if (sw6->pr_flags & PR_LASTHDR) { 827 struct netmsg_packet *pmsg; 828 lwkt_port_t port; 829 830 port = netisr_cpuport(0); /* XXX */ 831 KKASSERT(port != NULL); 832 pmsg = &m->m_hdr.mh_netmsg; 833 netmsg_init(&pmsg->base, NULL, 834 &netisr_apanic_rport, 835 0, transport6_processing_handler); 836 pmsg->nm_packet = m; 837 pmsg->nm_nxt = nxt; 838 pmsg->base.lmsg.u.ms_result = off; 839 lwkt_sendmsg(port, &pmsg->base.lmsg); 840 /* done with m */ 841 nxt = IPPROTO_DONE; 842 } else { 843 nxt = sw6->pr_input(&m, &off, nxt); 844 } 845 } 846 goto bad2; 847 bad: 848 m_freem(m); 849 bad2: 850 ; 851 /* msg was embedded in the mbuf, do not reply! */ 852 } 853 854 /* 855 * We have to call the pr_input() function from the correct protocol 856 * thread. The sw6->pr_soport() request at the end of ip6_input() 857 * returns the port and we forward a netmsg to the port to execute 858 * this function. 859 */ 860 static void 861 transport6_processing_handler(netmsg_t netmsg) 862 { 863 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg; 864 struct protosw *sw6; 865 int hlen; 866 int nxt; 867 868 sw6 = &inet6sw[ip6_protox[pmsg->nm_nxt]]; 869 hlen = pmsg->base.lmsg.u.ms_result; 870 871 nxt = sw6->pr_input(&pmsg->nm_packet, &hlen, pmsg->nm_nxt); 872 KKASSERT(nxt == IPPROTO_DONE); 873 /* netmsg was embedded in the mbuf, do not reply! */ 874 } 875 876 /* 877 * set/grab in6_ifaddr correspond to IPv6 destination address. 878 * XXX backward compatibility wrapper 879 */ 880 static struct ip6aux * 881 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 882 { 883 struct ip6aux *n; 884 885 n = ip6_addaux(m); 886 if (n) 887 n->ip6a_dstia6 = ia6; 888 return n; /* NULL if failed to set */ 889 } 890 891 struct in6_ifaddr * 892 ip6_getdstifaddr(struct mbuf *m) 893 { 894 struct ip6aux *n; 895 896 n = ip6_findaux(m); 897 if (n) 898 return n->ip6a_dstia6; 899 else 900 return NULL; 901 } 902 903 /* 904 * Hop-by-Hop options header processing. If a valid jumbo payload option is 905 * included, the real payload length will be stored in plenp. 906 */ 907 static int 908 ip6_hopopts_input(u_int32_t *plenp, 909 u_int32_t *rtalertp,/* XXX: should be stored more smart way */ 910 struct mbuf **mp, 911 int *offp) 912 { 913 struct mbuf *m = *mp; 914 int off = *offp, hbhlen; 915 struct ip6_hbh *hbh; 916 917 /* validation of the length of the header */ 918 #ifndef PULLDOWN_TEST 919 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 920 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 921 hbhlen = (hbh->ip6h_len + 1) << 3; 922 923 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 924 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 925 #else 926 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 927 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 928 if (hbh == NULL) { 929 ip6stat.ip6s_tooshort++; 930 return -1; 931 } 932 hbhlen = (hbh->ip6h_len + 1) << 3; 933 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 934 hbhlen); 935 if (hbh == NULL) { 936 ip6stat.ip6s_tooshort++; 937 return -1; 938 } 939 #endif 940 off += hbhlen; 941 hbhlen -= sizeof(struct ip6_hbh); 942 943 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 944 hbhlen, rtalertp, plenp) < 0) 945 return (-1); 946 947 *offp = off; 948 *mp = m; 949 return (0); 950 } 951 952 /* 953 * Search header for all Hop-by-hop options and process each option. 954 * This function is separate from ip6_hopopts_input() in order to 955 * handle a case where the sending node itself process its hop-by-hop 956 * options header. In such a case, the function is called from ip6_output(). 957 * 958 * The function assumes that hbh header is located right after the IPv6 header 959 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 960 * opthead + hbhlen is located in continuous memory region. 961 */ 962 int 963 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 964 u_int32_t *rtalertp, u_int32_t *plenp) 965 { 966 struct ip6_hdr *ip6; 967 int optlen = 0; 968 u_int8_t *opt = opthead; 969 u_int16_t rtalert_val; 970 u_int32_t jumboplen; 971 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 972 973 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 974 switch (*opt) { 975 case IP6OPT_PAD1: 976 optlen = 1; 977 break; 978 case IP6OPT_PADN: 979 if (hbhlen < IP6OPT_MINLEN) { 980 ip6stat.ip6s_toosmall++; 981 goto bad; 982 } 983 optlen = *(opt + 1) + 2; 984 break; 985 case IP6OPT_RTALERT: 986 /* XXX may need check for alignment */ 987 if (hbhlen < IP6OPT_RTALERT_LEN) { 988 ip6stat.ip6s_toosmall++; 989 goto bad; 990 } 991 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 992 /* XXX stat */ 993 icmp6_error(m, ICMP6_PARAM_PROB, 994 ICMP6_PARAMPROB_HEADER, 995 erroff + opt + 1 - opthead); 996 return (-1); 997 } 998 optlen = IP6OPT_RTALERT_LEN; 999 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1000 *rtalertp = ntohs(rtalert_val); 1001 break; 1002 case IP6OPT_JUMBO: 1003 /* XXX may need check for alignment */ 1004 if (hbhlen < IP6OPT_JUMBO_LEN) { 1005 ip6stat.ip6s_toosmall++; 1006 goto bad; 1007 } 1008 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1009 /* XXX stat */ 1010 icmp6_error(m, ICMP6_PARAM_PROB, 1011 ICMP6_PARAMPROB_HEADER, 1012 erroff + opt + 1 - opthead); 1013 return (-1); 1014 } 1015 optlen = IP6OPT_JUMBO_LEN; 1016 1017 /* 1018 * IPv6 packets that have non 0 payload length 1019 * must not contain a jumbo payload option. 1020 */ 1021 ip6 = mtod(m, struct ip6_hdr *); 1022 if (ip6->ip6_plen) { 1023 ip6stat.ip6s_badoptions++; 1024 icmp6_error(m, ICMP6_PARAM_PROB, 1025 ICMP6_PARAMPROB_HEADER, 1026 erroff + opt - opthead); 1027 return (-1); 1028 } 1029 1030 /* 1031 * We may see jumbolen in unaligned location, so 1032 * we'd need to perform bcopy(). 1033 */ 1034 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1035 jumboplen = (u_int32_t)htonl(jumboplen); 1036 1037 #if 1 1038 /* 1039 * if there are multiple jumbo payload options, 1040 * *plenp will be non-zero and the packet will be 1041 * rejected. 1042 * the behavior may need some debate in ipngwg - 1043 * multiple options does not make sense, however, 1044 * there's no explicit mention in specification. 1045 */ 1046 if (*plenp != 0) { 1047 ip6stat.ip6s_badoptions++; 1048 icmp6_error(m, ICMP6_PARAM_PROB, 1049 ICMP6_PARAMPROB_HEADER, 1050 erroff + opt + 2 - opthead); 1051 return (-1); 1052 } 1053 #endif 1054 1055 /* 1056 * jumbo payload length must be larger than 65535. 1057 */ 1058 if (jumboplen <= IPV6_MAXPACKET) { 1059 ip6stat.ip6s_badoptions++; 1060 icmp6_error(m, ICMP6_PARAM_PROB, 1061 ICMP6_PARAMPROB_HEADER, 1062 erroff + opt + 2 - opthead); 1063 return (-1); 1064 } 1065 *plenp = jumboplen; 1066 1067 break; 1068 default: /* unknown option */ 1069 if (hbhlen < IP6OPT_MINLEN) { 1070 ip6stat.ip6s_toosmall++; 1071 goto bad; 1072 } 1073 optlen = ip6_unknown_opt(opt, m, 1074 erroff + opt - opthead); 1075 if (optlen == -1) 1076 return (-1); 1077 optlen += 2; 1078 break; 1079 } 1080 } 1081 1082 return (0); 1083 1084 bad: 1085 m_freem(m); 1086 return (-1); 1087 } 1088 1089 /* 1090 * Unknown option processing. 1091 * The third argument `off' is the offset from the IPv6 header to the option, 1092 * which is necessary if the IPv6 header the and option header and IPv6 header 1093 * is not continuous in order to return an ICMPv6 error. 1094 */ 1095 int 1096 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1097 { 1098 struct ip6_hdr *ip6; 1099 1100 switch (IP6OPT_TYPE(*optp)) { 1101 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1102 return ((int)*(optp + 1)); 1103 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1104 m_freem(m); 1105 return (-1); 1106 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1107 ip6stat.ip6s_badoptions++; 1108 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1109 return (-1); 1110 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1111 ip6stat.ip6s_badoptions++; 1112 ip6 = mtod(m, struct ip6_hdr *); 1113 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1114 (m->m_flags & (M_BCAST|M_MCAST))) 1115 m_freem(m); 1116 else 1117 icmp6_error(m, ICMP6_PARAM_PROB, 1118 ICMP6_PARAMPROB_OPTION, off); 1119 return (-1); 1120 } 1121 1122 m_freem(m); /* XXX: NOTREACHED */ 1123 return (-1); 1124 } 1125 1126 /* 1127 * Create the "control" list for this pcb. 1128 * The function will not modify mbuf chain at all. 1129 * 1130 * with KAME mbuf chain restriction: 1131 * The routine will be called from upper layer handlers like tcp6_input(). 1132 * Thus the routine assumes that the caller (tcp6_input) have already 1133 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1134 * very first mbuf on the mbuf chain. 1135 */ 1136 void 1137 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6, 1138 struct mbuf *m) 1139 { 1140 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1141 struct thread *td = curthread; /* XXX */ 1142 int privileged = 0; 1143 1144 1145 if (priv_check(td, PRIV_ROOT) == 0) 1146 privileged++; 1147 1148 #ifdef SO_TIMESTAMP 1149 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1150 struct timeval tv; 1151 1152 microtime(&tv); 1153 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1154 SCM_TIMESTAMP, SOL_SOCKET); 1155 if (*mp) { 1156 mp = &(*mp)->m_next; 1157 } 1158 } 1159 #endif 1160 1161 /* RFC 2292 sec. 5 */ 1162 if (in6p->in6p_flags & IN6P_PKTINFO) { 1163 struct in6_pktinfo pi6; 1164 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1165 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1166 pi6.ipi6_addr.s6_addr16[1] = 0; 1167 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1168 ? m->m_pkthdr.rcvif->if_index 1169 : 0; 1170 *mp = sbcreatecontrol((caddr_t) &pi6, 1171 sizeof(struct in6_pktinfo), IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), 1172 IPPROTO_IPV6); 1173 if (*mp) 1174 mp = &(*mp)->m_next; 1175 } 1176 1177 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1178 int hlim = ip6->ip6_hlim & 0xff; 1179 *mp = sbcreatecontrol((caddr_t) &hlim, 1180 sizeof(int), IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1181 if (*mp) 1182 mp = &(*mp)->m_next; 1183 } 1184 1185 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1186 u_int32_t flowinfo; 1187 int tclass; 1188 1189 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1190 flowinfo >>= 20; 1191 1192 tclass = flowinfo & 0xff; 1193 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1194 IPV6_TCLASS, IPPROTO_IPV6); 1195 if (*mp) 1196 mp = &(*mp)->m_next; 1197 } 1198 1199 /* 1200 * IPV6_HOPOPTS socket option. We require super-user privilege 1201 * for the option, but it might be too strict, since there might 1202 * be some hop-by-hop options which can be returned to normal user. 1203 * See RFC 2292 section 6. 1204 */ 1205 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1206 /* 1207 * Check if a hop-by-hop options header is contatined in the 1208 * received packet, and if so, store the options as ancillary 1209 * data. Note that a hop-by-hop options header must be 1210 * just after the IPv6 header, which fact is assured through 1211 * the IPv6 input processing. 1212 */ 1213 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1214 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1215 struct ip6_hbh *hbh; 1216 int hbhlen = 0; 1217 #ifdef PULLDOWN_TEST 1218 struct mbuf *ext; 1219 #endif 1220 1221 #ifndef PULLDOWN_TEST 1222 hbh = (struct ip6_hbh *)(ip6 + 1); 1223 hbhlen = (hbh->ip6h_len + 1) << 3; 1224 #else 1225 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1226 ip6->ip6_nxt); 1227 if (ext == NULL) { 1228 ip6stat.ip6s_tooshort++; 1229 return; 1230 } 1231 hbh = mtod(ext, struct ip6_hbh *); 1232 hbhlen = (hbh->ip6h_len + 1) << 3; 1233 if (hbhlen != ext->m_len) { 1234 m_freem(ext); 1235 ip6stat.ip6s_tooshort++; 1236 return; 1237 } 1238 #endif 1239 1240 /* 1241 * XXX: We copy whole the header even if a jumbo 1242 * payload option is included, which option is to 1243 * be removed before returning in the RFC 2292. 1244 * Note: this constraint is removed in 2292bis. 1245 */ 1246 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1247 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), IPPROTO_IPV6); 1248 if (*mp) 1249 mp = &(*mp)->m_next; 1250 #ifdef PULLDOWN_TEST 1251 m_freem(ext); 1252 #endif 1253 } 1254 } 1255 1256 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1257 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1258 int proto, off, nxt; 1259 1260 /* 1261 * go through the header chain to see if a routing header is 1262 * contained in the packet. We need this information to store 1263 * destination options headers (if any) properly. 1264 * XXX: performance issue. We should record this info when 1265 * processing extension headers in incoming routine. 1266 * (todo) use m_aux? 1267 */ 1268 proto = IPPROTO_IPV6; 1269 off = 0; 1270 nxt = -1; 1271 while (1) { 1272 int newoff; 1273 1274 newoff = ip6_nexthdr(m, off, proto, &nxt); 1275 if (newoff < 0) 1276 break; 1277 if (newoff < off) /* invalid, check for safety */ 1278 break; 1279 if ((proto = nxt) == IPPROTO_ROUTING) 1280 break; 1281 off = newoff; 1282 } 1283 } 1284 1285 if ((in6p->in6p_flags & 1286 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1287 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1288 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1289 1290 /* 1291 * Search for destination options headers or routing 1292 * header(s) through the header chain, and stores each 1293 * header as ancillary data. 1294 * Note that the order of the headers remains in 1295 * the chain of ancillary data. 1296 */ 1297 while (1) { /* is explicit loop prevention necessary? */ 1298 struct ip6_ext *ip6e = NULL; 1299 int elen; 1300 #ifdef PULLDOWN_TEST 1301 struct mbuf *ext = NULL; 1302 #endif 1303 1304 /* 1305 * if it is not an extension header, don't try to 1306 * pull it from the chain. 1307 */ 1308 switch (nxt) { 1309 case IPPROTO_DSTOPTS: 1310 case IPPROTO_ROUTING: 1311 case IPPROTO_HOPOPTS: 1312 case IPPROTO_AH: /* is it possible? */ 1313 break; 1314 default: 1315 goto loopend; 1316 } 1317 1318 #ifndef PULLDOWN_TEST 1319 if (off + sizeof(*ip6e) > m->m_len) 1320 goto loopend; 1321 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1322 if (nxt == IPPROTO_AH) 1323 elen = (ip6e->ip6e_len + 2) << 2; 1324 else 1325 elen = (ip6e->ip6e_len + 1) << 3; 1326 if (off + elen > m->m_len) 1327 goto loopend; 1328 #else 1329 ext = ip6_pullexthdr(m, off, nxt); 1330 if (ext == NULL) { 1331 ip6stat.ip6s_tooshort++; 1332 return; 1333 } 1334 ip6e = mtod(ext, struct ip6_ext *); 1335 if (nxt == IPPROTO_AH) 1336 elen = (ip6e->ip6e_len + 2) << 2; 1337 else 1338 elen = (ip6e->ip6e_len + 1) << 3; 1339 if (elen != ext->m_len) { 1340 m_freem(ext); 1341 ip6stat.ip6s_tooshort++; 1342 return; 1343 } 1344 #endif 1345 1346 switch (nxt) { 1347 case IPPROTO_DSTOPTS: 1348 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1349 break; 1350 1351 /* 1352 * We also require super-user privilege for 1353 * the option. 1354 * See the comments on IN6_HOPOPTS. 1355 */ 1356 if (!privileged) 1357 break; 1358 1359 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1360 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1361 IPPROTO_IPV6); 1362 if (*mp) 1363 mp = &(*mp)->m_next; 1364 break; 1365 case IPPROTO_ROUTING: 1366 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1367 break; 1368 1369 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1370 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1371 IPPROTO_IPV6); 1372 if (*mp) 1373 mp = &(*mp)->m_next; 1374 break; 1375 case IPPROTO_HOPOPTS: 1376 case IPPROTO_AH: /* is it possible? */ 1377 break; 1378 1379 default: 1380 /* 1381 * other cases have been filtered in the above. 1382 * none will visit this case. here we supply 1383 * the code just in case (nxt overwritten or 1384 * other cases). 1385 */ 1386 #ifdef PULLDOWN_TEST 1387 m_freem(ext); 1388 #endif 1389 goto loopend; 1390 1391 } 1392 1393 /* proceed with the next header. */ 1394 off += elen; 1395 nxt = ip6e->ip6e_nxt; 1396 ip6e = NULL; 1397 #ifdef PULLDOWN_TEST 1398 m_freem(ext); 1399 ext = NULL; 1400 #endif 1401 } 1402 loopend: 1403 ; 1404 } 1405 #undef IS2292 1406 } 1407 1408 void 1409 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1410 { 1411 struct socket *so; 1412 struct mbuf *m_mtu; 1413 struct ip6_mtuinfo mtuctl; 1414 1415 so = in6p->inp_socket; 1416 1417 if (mtu == NULL) 1418 return; 1419 1420 #ifdef DIAGNOSTIC 1421 if (so == NULL) /* I believe this is impossible */ 1422 panic("ip6_notify_pmtu: socket is NULL"); 1423 #endif 1424 1425 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1426 mtuctl.ip6m_mtu = *mtu; 1427 mtuctl.ip6m_addr = *dst; 1428 1429 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1430 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1431 return; 1432 1433 lwkt_gettoken(&so->so_rcv.ssb_token); 1434 if (sbappendaddr(&so->so_rcv.sb, (struct sockaddr *)dst, NULL, m_mtu) 1435 == 0) { 1436 m_freem(m_mtu); 1437 /* XXX: should count statistics */ 1438 } else { 1439 sorwakeup(so); 1440 } 1441 lwkt_reltoken(&so->so_rcv.ssb_token); 1442 } 1443 1444 #ifdef PULLDOWN_TEST 1445 /* 1446 * pull single extension header from mbuf chain. returns single mbuf that 1447 * contains the result, or NULL on error. 1448 */ 1449 static struct mbuf * 1450 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1451 { 1452 struct ip6_ext ip6e; 1453 size_t elen; 1454 struct mbuf *n; 1455 1456 #ifdef DIAGNOSTIC 1457 switch (nxt) { 1458 case IPPROTO_DSTOPTS: 1459 case IPPROTO_ROUTING: 1460 case IPPROTO_HOPOPTS: 1461 case IPPROTO_AH: /* is it possible? */ 1462 break; 1463 default: 1464 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1465 } 1466 #endif 1467 1468 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1469 if (nxt == IPPROTO_AH) 1470 elen = (ip6e.ip6e_len + 2) << 2; 1471 else 1472 elen = (ip6e.ip6e_len + 1) << 3; 1473 1474 n = m_getb(elen, MB_DONTWAIT, MT_DATA, 0); 1475 if (n == NULL) 1476 return NULL; 1477 n->m_len = 0; 1478 1479 if (elen >= M_TRAILINGSPACE(n)) { 1480 m_free(n); 1481 return NULL; 1482 } 1483 1484 m_copydata(m, off, elen, mtod(n, caddr_t)); 1485 n->m_len = elen; 1486 return n; 1487 } 1488 #endif 1489 1490 /* 1491 * Get pointer to the previous header followed by the header 1492 * currently processed. 1493 * XXX: This function supposes that 1494 * M includes all headers, 1495 * the next header field and the header length field of each header 1496 * are valid, and 1497 * the sum of each header length equals to OFF. 1498 * Because of these assumptions, this function must be called very 1499 * carefully. Moreover, it will not be used in the near future when 1500 * we develop `neater' mechanism to process extension headers. 1501 */ 1502 char * 1503 ip6_get_prevhdr(struct mbuf *m, int off) 1504 { 1505 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1506 1507 if (off == sizeof(struct ip6_hdr)) 1508 return (&ip6->ip6_nxt); 1509 else { 1510 int len, nxt; 1511 struct ip6_ext *ip6e = NULL; 1512 1513 nxt = ip6->ip6_nxt; 1514 len = sizeof(struct ip6_hdr); 1515 while (len < off) { 1516 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1517 1518 switch (nxt) { 1519 case IPPROTO_FRAGMENT: 1520 len += sizeof(struct ip6_frag); 1521 break; 1522 case IPPROTO_AH: 1523 len += (ip6e->ip6e_len + 2) << 2; 1524 break; 1525 default: 1526 len += (ip6e->ip6e_len + 1) << 3; 1527 break; 1528 } 1529 nxt = ip6e->ip6e_nxt; 1530 } 1531 if (ip6e) 1532 return (&ip6e->ip6e_nxt); 1533 else 1534 return NULL; 1535 } 1536 } 1537 1538 /* 1539 * get next header offset. m will be retained. 1540 */ 1541 int 1542 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1543 { 1544 struct ip6_hdr ip6; 1545 struct ip6_ext ip6e; 1546 struct ip6_frag fh; 1547 1548 /* just in case */ 1549 if (m == NULL) 1550 panic("ip6_nexthdr: m == NULL"); 1551 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1552 return -1; 1553 1554 switch (proto) { 1555 case IPPROTO_IPV6: 1556 if (m->m_pkthdr.len < off + sizeof(ip6)) 1557 return -1; 1558 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1559 if (nxtp) 1560 *nxtp = ip6.ip6_nxt; 1561 off += sizeof(ip6); 1562 return off; 1563 1564 case IPPROTO_FRAGMENT: 1565 /* 1566 * terminate parsing if it is not the first fragment, 1567 * it does not make sense to parse through it. 1568 */ 1569 if (m->m_pkthdr.len < off + sizeof(fh)) 1570 return -1; 1571 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1572 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1573 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1574 return -1; 1575 if (nxtp) 1576 *nxtp = fh.ip6f_nxt; 1577 off += sizeof(struct ip6_frag); 1578 return off; 1579 1580 case IPPROTO_AH: 1581 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1582 return -1; 1583 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1584 if (nxtp) 1585 *nxtp = ip6e.ip6e_nxt; 1586 off += (ip6e.ip6e_len + 2) << 2; 1587 return off; 1588 1589 case IPPROTO_HOPOPTS: 1590 case IPPROTO_ROUTING: 1591 case IPPROTO_DSTOPTS: 1592 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1593 return -1; 1594 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1595 if (nxtp) 1596 *nxtp = ip6e.ip6e_nxt; 1597 off += (ip6e.ip6e_len + 1) << 3; 1598 return off; 1599 1600 case IPPROTO_NONE: 1601 case IPPROTO_ESP: 1602 case IPPROTO_IPCOMP: 1603 /* give up */ 1604 return -1; 1605 1606 default: 1607 return -1; 1608 } 1609 1610 return -1; 1611 } 1612 1613 /* 1614 * get offset for the last header in the chain. m will be kept untainted. 1615 */ 1616 int 1617 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1618 { 1619 int newoff; 1620 int nxt; 1621 1622 if (!nxtp) { 1623 nxt = -1; 1624 nxtp = &nxt; 1625 } 1626 while (1) { 1627 newoff = ip6_nexthdr(m, off, proto, nxtp); 1628 if (newoff < 0) 1629 return off; 1630 else if (newoff < off) 1631 return -1; /* invalid */ 1632 else if (newoff == off) 1633 return newoff; 1634 1635 off = newoff; 1636 proto = *nxtp; 1637 } 1638 } 1639 1640 struct ip6aux * 1641 ip6_addaux(struct mbuf *m) 1642 { 1643 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1644 if (!tag) { 1645 tag = m_tag_get(PACKET_TAG_IPV6_INPUT, 1646 sizeof (struct ip6aux), 1647 MB_DONTWAIT); 1648 if (tag) 1649 m_tag_prepend(m, tag); 1650 } 1651 if (tag) 1652 bzero(m_tag_data(tag), sizeof (struct ip6aux)); 1653 return tag ? (struct ip6aux *)m_tag_data(tag) : NULL; 1654 } 1655 1656 struct ip6aux * 1657 ip6_findaux(struct mbuf *m) 1658 { 1659 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1660 return tag ? (struct ip6aux*)(tag+1) : NULL; 1661 } 1662 1663 void 1664 ip6_delaux(struct mbuf *m) 1665 { 1666 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1667 if (tag) 1668 m_tag_delete(m, tag); 1669 } 1670 1671 /* 1672 * System control for IP6 1673 */ 1674 1675 u_char inet6ctlerrmap[PRC_NCMDS] = { 1676 0, 0, 0, 0, 1677 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1678 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1679 EMSGSIZE, EHOSTUNREACH, 0, 0, 1680 0, 0, 0, 0, 1681 ENOPROTOOPT 1682 }; 1683