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->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 * Now there is no reason to process the packet if it's not our own 545 * and we're not a router. 546 */ 547 if (!ip6_forwarding) { 548 ip6stat.ip6s_cantforward++; 549 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 550 goto bad; 551 } 552 553 hbhcheck: 554 /* 555 * record address information into m_aux, if we don't have one yet. 556 * note that we are unable to record it, if the address is not listed 557 * as our interface address (e.g. multicast addresses and such). 558 */ 559 if (deliverifp && !ip6_getdstifaddr(m)) { 560 struct in6_ifaddr *ia6; 561 562 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 563 if (ia6) { 564 if (!ip6_setdstifaddr(m, ia6)) { 565 /* 566 * XXX maybe we should drop the packet here, 567 * as we could not provide enough information 568 * to the upper layers. 569 */ 570 } 571 } 572 } 573 574 /* 575 * Process Hop-by-Hop options header if it's contained. 576 * m may be modified in ip6_hopopts_input(). 577 * If a JumboPayload option is included, plen will also be modified. 578 */ 579 plen = (u_int32_t)ntohs(ip6->ip6_plen); 580 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 581 struct ip6_hbh *hbh; 582 583 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 584 #if 0 /*touches NULL pointer*/ 585 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 586 #endif 587 goto bad2; /* m have already been freed */ 588 } 589 590 /* adjust pointer */ 591 ip6 = mtod(m, struct ip6_hdr *); 592 593 /* 594 * if the payload length field is 0 and the next header field 595 * indicates Hop-by-Hop Options header, then a Jumbo Payload 596 * option MUST be included. 597 */ 598 if (ip6->ip6_plen == 0 && plen == 0) { 599 /* 600 * Note that if a valid jumbo payload option is 601 * contained, ip6_hoptops_input() must set a valid 602 * (non-zero) payload length to the variable plen. 603 */ 604 ip6stat.ip6s_badoptions++; 605 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 606 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 607 icmp6_error(m, ICMP6_PARAM_PROB, 608 ICMP6_PARAMPROB_HEADER, 609 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 610 goto bad2; 611 } 612 #ifndef PULLDOWN_TEST 613 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 614 hbh = (struct ip6_hbh *)(ip6 + 1); 615 #else 616 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 617 sizeof(struct ip6_hbh)); 618 if (hbh == NULL) { 619 ip6stat.ip6s_tooshort++; 620 goto bad2; 621 } 622 #endif 623 nxt = hbh->ip6h_nxt; 624 625 /* 626 * If we are acting as a router and the packet contains a 627 * router alert option, see if we know the option value. 628 * Currently, we only support the option value for MLD, in which 629 * case we should pass the packet to the multicast routing 630 * daemon. 631 */ 632 if (rtalert != ~0 && ip6_forwarding) { 633 switch (rtalert) { 634 case IP6OPT_RTALERT_MLD: 635 ours = 1; 636 break; 637 default: 638 /* 639 * RFC2711 requires unrecognized values must be 640 * silently ignored. 641 */ 642 break; 643 } 644 } 645 } else 646 nxt = ip6->ip6_nxt; 647 648 /* 649 * Check that the amount of data in the buffers 650 * is as at least much as the IPv6 header would have us expect. 651 * Trim mbufs if longer than we expect. 652 * Drop packet if shorter than we expect. 653 */ 654 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 655 ip6stat.ip6s_tooshort++; 656 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 657 goto bad; 658 } 659 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 660 if (m->m_len == m->m_pkthdr.len) { 661 m->m_len = sizeof(struct ip6_hdr) + plen; 662 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 663 } else 664 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 665 } 666 667 /* 668 * Forward if desirable. 669 */ 670 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 671 /* 672 * If we are acting as a multicast router, all 673 * incoming multicast packets are passed to the 674 * kernel-level multicast forwarding function. 675 * The packet is returned (relatively) intact; if 676 * ip6_mforward() returns a non-zero value, the packet 677 * must be discarded, else it may be accepted below. 678 */ 679 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 680 ip6stat.ip6s_cantforward++; 681 goto bad; 682 } 683 if (!ours) 684 goto bad; 685 } else if (!ours) { 686 ip6_forward(m, srcrt); 687 goto bad2; 688 } 689 690 ip6 = mtod(m, struct ip6_hdr *); 691 692 /* 693 * Malicious party may be able to use IPv4 mapped addr to confuse 694 * tcp/udp stack and bypass security checks (act as if it was from 695 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 696 * 697 * For SIIT end node behavior, you may want to disable the check. 698 * However, you will become vulnerable to attacks using IPv4 mapped 699 * source. 700 */ 701 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 702 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 703 ip6stat.ip6s_badscope++; 704 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 705 goto bad; 706 } 707 708 /* 709 * Tell launch routine the next header 710 */ 711 ip6stat.ip6s_delivered++; 712 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 713 nest = 0; 714 715 rh_present = 0; 716 while (nxt != IPPROTO_DONE) { 717 struct protosw *sw6; 718 719 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 720 ip6stat.ip6s_toomanyhdr++; 721 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 722 goto bad; 723 } 724 725 /* 726 * protection against faulty packet - there should be 727 * more sanity checks in header chain processing. 728 */ 729 if (m->m_pkthdr.len < off) { 730 ip6stat.ip6s_tooshort++; 731 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 732 goto bad; 733 } 734 735 #if 0 736 /* 737 * do we need to do it for every header? yeah, other 738 * functions can play with it (like re-allocate and copy). 739 */ 740 mhist = ip6_addaux(m); 741 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 742 hist = mtod(mhist, caddr_t) + mhist->m_len; 743 bcopy(&nxt, hist, sizeof(nxt)); 744 mhist->m_len += sizeof(nxt); 745 } else { 746 ip6stat.ip6s_toomanyhdr++; 747 goto bad; 748 } 749 #endif 750 751 if (nxt == IPPROTO_ROUTING) { 752 if (rh_present++) { 753 in6_ifstat_inc(m->m_pkthdr.rcvif, 754 ifs6_in_hdrerr); 755 ip6stat.ip6s_badoptions++; 756 goto bad; 757 } 758 } 759 760 sw6 = &inet6sw[ip6_protox[nxt]]; 761 #ifdef IPSEC 762 /* 763 * enforce IPsec policy checking if we are seeing last header. 764 * note that we do not visit this with protocols with pcb layer 765 * code - like udp/tcp/raw ip. 766 */ 767 if ((sw6->pr_flags & PR_LASTHDR) && ipsec6_in_reject(m, NULL)) { 768 ipsec6stat.in_polvio++; 769 goto bad; 770 } 771 #endif 772 /* 773 * If this is a terminal header forward to the port, otherwise 774 * process synchronously for more headers. 775 */ 776 if (sw6->pr_flags & PR_LASTHDR) { 777 struct netmsg_packet *pmsg; 778 lwkt_port_t port; 779 780 port = netisr_cpuport(0); /* XXX */ 781 if ((m->m_flags & M_HASH) == 0) 782 m_sethash(m, 0); /* XXX */ 783 784 KKASSERT(port != NULL); 785 pmsg = &m->m_hdr.mh_netmsg; 786 netmsg_init(&pmsg->base, NULL, 787 &netisr_apanic_rport, 788 0, transport6_processing_handler); 789 pmsg->nm_packet = m; 790 pmsg->nm_nxt = nxt; 791 pmsg->base.lmsg.u.ms_result = off; 792 lwkt_sendmsg(port, &pmsg->base.lmsg); 793 /* done with m */ 794 nxt = IPPROTO_DONE; 795 } else { 796 nxt = sw6->pr_input(&m, &off, nxt); 797 } 798 } 799 goto bad2; 800 bad: 801 m_freem(m); 802 bad2: 803 ; 804 /* msg was embedded in the mbuf, do not reply! */ 805 } 806 807 /* 808 * We have to call the pr_input() function from the correct protocol 809 * thread. The sw6->pr_soport() request at the end of ip6_input() 810 * returns the port and we forward a netmsg to the port to execute 811 * this function. 812 */ 813 static void 814 transport6_processing_handler(netmsg_t netmsg) 815 { 816 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg; 817 struct protosw *sw6; 818 int hlen; 819 int nxt; 820 821 sw6 = &inet6sw[ip6_protox[pmsg->nm_nxt]]; 822 hlen = pmsg->base.lmsg.u.ms_result; 823 824 nxt = sw6->pr_input(&pmsg->nm_packet, &hlen, pmsg->nm_nxt); 825 KKASSERT(nxt == IPPROTO_DONE); 826 /* netmsg was embedded in the mbuf, do not reply! */ 827 } 828 829 /* 830 * set/grab in6_ifaddr correspond to IPv6 destination address. 831 * XXX backward compatibility wrapper 832 */ 833 static struct ip6aux * 834 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 835 { 836 struct ip6aux *n; 837 838 n = ip6_addaux(m); 839 if (n) 840 n->ip6a_dstia6 = ia6; 841 return n; /* NULL if failed to set */ 842 } 843 844 struct in6_ifaddr * 845 ip6_getdstifaddr(struct mbuf *m) 846 { 847 struct ip6aux *n; 848 849 n = ip6_findaux(m); 850 if (n) 851 return n->ip6a_dstia6; 852 else 853 return NULL; 854 } 855 856 /* 857 * Hop-by-Hop options header processing. If a valid jumbo payload option is 858 * included, the real payload length will be stored in plenp. 859 */ 860 static int 861 ip6_hopopts_input(u_int32_t *plenp, 862 u_int32_t *rtalertp,/* XXX: should be stored more smart way */ 863 struct mbuf **mp, 864 int *offp) 865 { 866 struct mbuf *m = *mp; 867 int off = *offp, hbhlen; 868 struct ip6_hbh *hbh; 869 870 /* validation of the length of the header */ 871 #ifndef PULLDOWN_TEST 872 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 873 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 874 hbhlen = (hbh->ip6h_len + 1) << 3; 875 876 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 877 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 878 #else 879 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 880 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 881 if (hbh == NULL) { 882 ip6stat.ip6s_tooshort++; 883 return -1; 884 } 885 hbhlen = (hbh->ip6h_len + 1) << 3; 886 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 887 hbhlen); 888 if (hbh == NULL) { 889 ip6stat.ip6s_tooshort++; 890 return -1; 891 } 892 #endif 893 off += hbhlen; 894 hbhlen -= sizeof(struct ip6_hbh); 895 896 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 897 hbhlen, rtalertp, plenp) < 0) 898 return (-1); 899 900 *offp = off; 901 *mp = m; 902 return (0); 903 } 904 905 /* 906 * Search header for all Hop-by-hop options and process each option. 907 * This function is separate from ip6_hopopts_input() in order to 908 * handle a case where the sending node itself process its hop-by-hop 909 * options header. In such a case, the function is called from ip6_output(). 910 * 911 * The function assumes that hbh header is located right after the IPv6 header 912 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 913 * opthead + hbhlen is located in continuous memory region. 914 */ 915 int 916 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 917 u_int32_t *rtalertp, u_int32_t *plenp) 918 { 919 struct ip6_hdr *ip6; 920 int optlen = 0; 921 u_int8_t *opt = opthead; 922 u_int16_t rtalert_val; 923 u_int32_t jumboplen; 924 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 925 926 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 927 switch (*opt) { 928 case IP6OPT_PAD1: 929 optlen = 1; 930 break; 931 case IP6OPT_PADN: 932 if (hbhlen < IP6OPT_MINLEN) { 933 ip6stat.ip6s_toosmall++; 934 goto bad; 935 } 936 optlen = *(opt + 1) + 2; 937 break; 938 case IP6OPT_RTALERT: 939 /* XXX may need check for alignment */ 940 if (hbhlen < IP6OPT_RTALERT_LEN) { 941 ip6stat.ip6s_toosmall++; 942 goto bad; 943 } 944 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 945 /* XXX stat */ 946 icmp6_error(m, ICMP6_PARAM_PROB, 947 ICMP6_PARAMPROB_HEADER, 948 erroff + opt + 1 - opthead); 949 return (-1); 950 } 951 optlen = IP6OPT_RTALERT_LEN; 952 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 953 *rtalertp = ntohs(rtalert_val); 954 break; 955 case IP6OPT_JUMBO: 956 /* XXX may need check for alignment */ 957 if (hbhlen < IP6OPT_JUMBO_LEN) { 958 ip6stat.ip6s_toosmall++; 959 goto bad; 960 } 961 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 962 /* XXX stat */ 963 icmp6_error(m, ICMP6_PARAM_PROB, 964 ICMP6_PARAMPROB_HEADER, 965 erroff + opt + 1 - opthead); 966 return (-1); 967 } 968 optlen = IP6OPT_JUMBO_LEN; 969 970 /* 971 * IPv6 packets that have non 0 payload length 972 * must not contain a jumbo payload option. 973 */ 974 ip6 = mtod(m, struct ip6_hdr *); 975 if (ip6->ip6_plen) { 976 ip6stat.ip6s_badoptions++; 977 icmp6_error(m, ICMP6_PARAM_PROB, 978 ICMP6_PARAMPROB_HEADER, 979 erroff + opt - opthead); 980 return (-1); 981 } 982 983 /* 984 * We may see jumbolen in unaligned location, so 985 * we'd need to perform bcopy(). 986 */ 987 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 988 jumboplen = (u_int32_t)htonl(jumboplen); 989 990 #if 1 991 /* 992 * if there are multiple jumbo payload options, 993 * *plenp will be non-zero and the packet will be 994 * rejected. 995 * the behavior may need some debate in ipngwg - 996 * multiple options does not make sense, however, 997 * there's no explicit mention in specification. 998 */ 999 if (*plenp != 0) { 1000 ip6stat.ip6s_badoptions++; 1001 icmp6_error(m, ICMP6_PARAM_PROB, 1002 ICMP6_PARAMPROB_HEADER, 1003 erroff + opt + 2 - opthead); 1004 return (-1); 1005 } 1006 #endif 1007 1008 /* 1009 * jumbo payload length must be larger than 65535. 1010 */ 1011 if (jumboplen <= IPV6_MAXPACKET) { 1012 ip6stat.ip6s_badoptions++; 1013 icmp6_error(m, ICMP6_PARAM_PROB, 1014 ICMP6_PARAMPROB_HEADER, 1015 erroff + opt + 2 - opthead); 1016 return (-1); 1017 } 1018 *plenp = jumboplen; 1019 1020 break; 1021 default: /* unknown option */ 1022 if (hbhlen < IP6OPT_MINLEN) { 1023 ip6stat.ip6s_toosmall++; 1024 goto bad; 1025 } 1026 optlen = ip6_unknown_opt(opt, m, 1027 erroff + opt - opthead); 1028 if (optlen == -1) 1029 return (-1); 1030 optlen += 2; 1031 break; 1032 } 1033 } 1034 1035 return (0); 1036 1037 bad: 1038 m_freem(m); 1039 return (-1); 1040 } 1041 1042 /* 1043 * Unknown option processing. 1044 * The third argument `off' is the offset from the IPv6 header to the option, 1045 * which is necessary if the IPv6 header the and option header and IPv6 header 1046 * is not continuous in order to return an ICMPv6 error. 1047 */ 1048 int 1049 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1050 { 1051 struct ip6_hdr *ip6; 1052 1053 switch (IP6OPT_TYPE(*optp)) { 1054 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1055 return ((int)*(optp + 1)); 1056 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1057 m_freem(m); 1058 return (-1); 1059 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1060 ip6stat.ip6s_badoptions++; 1061 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1062 return (-1); 1063 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1064 ip6stat.ip6s_badoptions++; 1065 ip6 = mtod(m, struct ip6_hdr *); 1066 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1067 (m->m_flags & (M_BCAST|M_MCAST))) 1068 m_freem(m); 1069 else 1070 icmp6_error(m, ICMP6_PARAM_PROB, 1071 ICMP6_PARAMPROB_OPTION, off); 1072 return (-1); 1073 } 1074 1075 m_freem(m); /* XXX: NOTREACHED */ 1076 return (-1); 1077 } 1078 1079 /* 1080 * Create the "control" list for this pcb. 1081 * The function will not modify mbuf chain at all. 1082 * 1083 * with KAME mbuf chain restriction: 1084 * The routine will be called from upper layer handlers like tcp6_input(). 1085 * Thus the routine assumes that the caller (tcp6_input) have already 1086 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1087 * very first mbuf on the mbuf chain. 1088 */ 1089 void 1090 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6, 1091 struct mbuf *m) 1092 { 1093 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1094 struct thread *td = curthread; /* XXX */ 1095 int privileged = 0; 1096 1097 1098 if (priv_check(td, PRIV_ROOT) == 0) 1099 privileged++; 1100 1101 #ifdef SO_TIMESTAMP 1102 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1103 struct timeval tv; 1104 1105 microtime(&tv); 1106 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv), 1107 SCM_TIMESTAMP, SOL_SOCKET); 1108 if (*mp) { 1109 mp = &(*mp)->m_next; 1110 } 1111 } 1112 #endif 1113 1114 /* RFC 2292 sec. 5 */ 1115 if (in6p->in6p_flags & IN6P_PKTINFO) { 1116 struct in6_pktinfo pi6; 1117 1118 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1119 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1120 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) ? 1121 m->m_pkthdr.rcvif->if_index : 0; 1122 *mp = sbcreatecontrol((caddr_t)&pi6, sizeof(struct in6_pktinfo), 1123 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1124 if (*mp) 1125 mp = &(*mp)->m_next; 1126 } 1127 1128 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1129 int hlim = ip6->ip6_hlim & 0xff; 1130 1131 *mp = sbcreatecontrol((caddr_t)&hlim, sizeof(int), 1132 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1133 if (*mp) 1134 mp = &(*mp)->m_next; 1135 } 1136 1137 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1138 u_int32_t flowinfo; 1139 int tclass; 1140 1141 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1142 flowinfo >>= 20; 1143 1144 tclass = flowinfo & 0xff; 1145 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1146 IPV6_TCLASS, IPPROTO_IPV6); 1147 if (*mp) 1148 mp = &(*mp)->m_next; 1149 } 1150 1151 /* 1152 * IPV6_HOPOPTS socket option. We require super-user privilege 1153 * for the option, but it might be too strict, since there might 1154 * be some hop-by-hop options which can be returned to normal user. 1155 * See RFC 2292 section 6. 1156 */ 1157 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1158 /* 1159 * Check if a hop-by-hop options header is contatined in the 1160 * received packet, and if so, store the options as ancillary 1161 * data. Note that a hop-by-hop options header must be 1162 * just after the IPv6 header, which is assured through the 1163 * IPv6 input processing. 1164 */ 1165 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1166 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1167 struct ip6_hbh *hbh; 1168 int hbhlen = 0; 1169 #ifdef PULLDOWN_TEST 1170 struct mbuf *ext; 1171 #endif 1172 1173 #ifndef PULLDOWN_TEST 1174 hbh = (struct ip6_hbh *)(ip6 + 1); 1175 hbhlen = (hbh->ip6h_len + 1) << 3; 1176 #else 1177 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1178 ip6->ip6_nxt); 1179 if (ext == NULL) { 1180 ip6stat.ip6s_tooshort++; 1181 return; 1182 } 1183 hbh = mtod(ext, struct ip6_hbh *); 1184 hbhlen = (hbh->ip6h_len + 1) << 3; 1185 if (hbhlen != ext->m_len) { 1186 m_freem(ext); 1187 ip6stat.ip6s_tooshort++; 1188 return; 1189 } 1190 #endif 1191 1192 /* 1193 * XXX: We copy the whole header even if a 1194 * jumbo payload option is included, the option which 1195 * is to be removed before returning according to 1196 * RFC 2292. 1197 * Note: this constraint is removed in 2292bis. 1198 */ 1199 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1200 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1201 IPPROTO_IPV6); 1202 if (*mp) 1203 mp = &(*mp)->m_next; 1204 #ifdef PULLDOWN_TEST 1205 m_freem(ext); 1206 #endif 1207 } 1208 } 1209 1210 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1211 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1212 int proto, off, nxt; 1213 1214 /* 1215 * go through the header chain to see if a routing header is 1216 * contained in the packet. We need this information to store 1217 * destination options headers (if any) properly. 1218 * XXX: performance issue. We should record this info when 1219 * processing extension headers in incoming routine. 1220 * (todo) use m_aux? 1221 */ 1222 proto = IPPROTO_IPV6; 1223 off = 0; 1224 nxt = -1; 1225 while (1) { 1226 int newoff; 1227 1228 newoff = ip6_nexthdr(m, off, proto, &nxt); 1229 if (newoff < 0) 1230 break; 1231 if (newoff < off) /* invalid, check for safety */ 1232 break; 1233 if ((proto = nxt) == IPPROTO_ROUTING) 1234 break; 1235 off = newoff; 1236 } 1237 } 1238 1239 if ((in6p->in6p_flags & 1240 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1241 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1242 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1243 1244 /* 1245 * Search for destination options headers or routing 1246 * header(s) through the header chain, and stores each 1247 * header as ancillary data. 1248 * Note that the order of the headers remains in 1249 * the chain of ancillary data. 1250 */ 1251 while (1) { /* is explicit loop prevention necessary? */ 1252 struct ip6_ext *ip6e = NULL; 1253 int elen; 1254 #ifdef PULLDOWN_TEST 1255 struct mbuf *ext = NULL; 1256 #endif 1257 1258 /* 1259 * if it is not an extension header, don't try to 1260 * pull it from the chain. 1261 */ 1262 switch (nxt) { 1263 case IPPROTO_DSTOPTS: 1264 case IPPROTO_ROUTING: 1265 case IPPROTO_HOPOPTS: 1266 case IPPROTO_AH: /* is it possible? */ 1267 break; 1268 default: 1269 goto loopend; 1270 } 1271 1272 #ifndef PULLDOWN_TEST 1273 if (off + sizeof(*ip6e) > m->m_len) 1274 goto loopend; 1275 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1276 if (nxt == IPPROTO_AH) 1277 elen = (ip6e->ip6e_len + 2) << 2; 1278 else 1279 elen = (ip6e->ip6e_len + 1) << 3; 1280 if (off + elen > m->m_len) 1281 goto loopend; 1282 #else 1283 ext = ip6_pullexthdr(m, off, nxt); 1284 if (ext == NULL) { 1285 ip6stat.ip6s_tooshort++; 1286 return; 1287 } 1288 ip6e = mtod(ext, struct ip6_ext *); 1289 if (nxt == IPPROTO_AH) 1290 elen = (ip6e->ip6e_len + 2) << 2; 1291 else 1292 elen = (ip6e->ip6e_len + 1) << 3; 1293 if (elen != ext->m_len) { 1294 m_freem(ext); 1295 ip6stat.ip6s_tooshort++; 1296 return; 1297 } 1298 #endif 1299 1300 switch (nxt) { 1301 case IPPROTO_DSTOPTS: 1302 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1303 break; 1304 1305 /* 1306 * We also require super-user privilege for 1307 * the option. See comments on IN6_HOPOPTS. 1308 */ 1309 if (!privileged) 1310 break; 1311 1312 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1313 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1314 IPPROTO_IPV6); 1315 if (*mp) 1316 mp = &(*mp)->m_next; 1317 break; 1318 case IPPROTO_ROUTING: 1319 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1320 break; 1321 1322 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1323 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1324 IPPROTO_IPV6); 1325 if (*mp) 1326 mp = &(*mp)->m_next; 1327 break; 1328 case IPPROTO_HOPOPTS: 1329 case IPPROTO_AH: /* is it possible? */ 1330 break; 1331 1332 default: 1333 /* 1334 * other cases have been filtered in the above. 1335 * none will visit this case. here we supply 1336 * the code just in case (nxt overwritten or 1337 * other cases). 1338 */ 1339 #ifdef PULLDOWN_TEST 1340 m_freem(ext); 1341 #endif 1342 goto loopend; 1343 1344 } 1345 1346 /* proceed with the next header. */ 1347 off += elen; 1348 nxt = ip6e->ip6e_nxt; 1349 ip6e = NULL; 1350 #ifdef PULLDOWN_TEST 1351 m_freem(ext); 1352 ext = NULL; 1353 #endif 1354 } 1355 loopend: 1356 ; 1357 } 1358 #undef IS2292 1359 } 1360 1361 void 1362 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1363 { 1364 struct socket *so; 1365 struct mbuf *m_mtu; 1366 struct ip6_mtuinfo mtuctl; 1367 1368 so = in6p->inp_socket; 1369 1370 if (mtu == NULL) 1371 return; 1372 1373 #ifdef DIAGNOSTIC 1374 if (so == NULL) /* I believe this is impossible */ 1375 panic("ip6_notify_pmtu: socket is NULL"); 1376 #endif 1377 1378 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1379 mtuctl.ip6m_mtu = *mtu; 1380 mtuctl.ip6m_addr = *dst; 1381 1382 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1383 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1384 return; 1385 1386 lwkt_gettoken(&so->so_rcv.ssb_token); 1387 if (sbappendaddr(&so->so_rcv.sb, (struct sockaddr *)dst, NULL, m_mtu) 1388 == 0) { 1389 m_freem(m_mtu); 1390 /* XXX: should count statistics */ 1391 } else { 1392 sorwakeup(so); 1393 } 1394 lwkt_reltoken(&so->so_rcv.ssb_token); 1395 } 1396 1397 #ifdef PULLDOWN_TEST 1398 /* 1399 * pull single extension header from mbuf chain. returns single mbuf that 1400 * contains the result, or NULL on error. 1401 */ 1402 static struct mbuf * 1403 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1404 { 1405 struct ip6_ext ip6e; 1406 size_t elen; 1407 struct mbuf *n; 1408 1409 #ifdef DIAGNOSTIC 1410 switch (nxt) { 1411 case IPPROTO_DSTOPTS: 1412 case IPPROTO_ROUTING: 1413 case IPPROTO_HOPOPTS: 1414 case IPPROTO_AH: /* is it possible? */ 1415 break; 1416 default: 1417 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1418 } 1419 #endif 1420 1421 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1422 if (nxt == IPPROTO_AH) 1423 elen = (ip6e.ip6e_len + 2) << 2; 1424 else 1425 elen = (ip6e.ip6e_len + 1) << 3; 1426 1427 n = m_getb(elen, M_NOWAIT, MT_DATA, 0); 1428 if (n == NULL) 1429 return NULL; 1430 n->m_len = 0; 1431 1432 if (elen >= M_TRAILINGSPACE(n)) { 1433 m_free(n); 1434 return NULL; 1435 } 1436 1437 m_copydata(m, off, elen, mtod(n, caddr_t)); 1438 n->m_len = elen; 1439 return n; 1440 } 1441 #endif 1442 1443 /* 1444 * Get pointer to the previous header followed by the header 1445 * currently processed. 1446 * XXX: This function supposes that 1447 * M includes all headers, 1448 * the next header field and the header length field of each header 1449 * are valid, and 1450 * the sum of each header length equals to OFF. 1451 * Because of these assumptions, this function must be called very 1452 * carefully. Moreover, it will not be used in the near future when 1453 * we develop `neater' mechanism to process extension headers. 1454 */ 1455 char * 1456 ip6_get_prevhdr(struct mbuf *m, int off) 1457 { 1458 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1459 1460 if (off == sizeof(struct ip6_hdr)) 1461 return (&ip6->ip6_nxt); 1462 else { 1463 int len, nxt; 1464 struct ip6_ext *ip6e = NULL; 1465 1466 nxt = ip6->ip6_nxt; 1467 len = sizeof(struct ip6_hdr); 1468 while (len < off) { 1469 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1470 1471 switch (nxt) { 1472 case IPPROTO_FRAGMENT: 1473 len += sizeof(struct ip6_frag); 1474 break; 1475 case IPPROTO_AH: 1476 len += (ip6e->ip6e_len + 2) << 2; 1477 break; 1478 default: 1479 len += (ip6e->ip6e_len + 1) << 3; 1480 break; 1481 } 1482 nxt = ip6e->ip6e_nxt; 1483 } 1484 if (ip6e) 1485 return (&ip6e->ip6e_nxt); 1486 else 1487 return NULL; 1488 } 1489 } 1490 1491 /* 1492 * get next header offset. m will be retained. 1493 */ 1494 int 1495 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1496 { 1497 struct ip6_hdr ip6; 1498 struct ip6_ext ip6e; 1499 struct ip6_frag fh; 1500 1501 /* just in case */ 1502 if (m == NULL) 1503 panic("ip6_nexthdr: m == NULL"); 1504 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1505 return -1; 1506 1507 switch (proto) { 1508 case IPPROTO_IPV6: 1509 if (m->m_pkthdr.len < off + sizeof(ip6)) 1510 return -1; 1511 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1512 if (nxtp) 1513 *nxtp = ip6.ip6_nxt; 1514 off += sizeof(ip6); 1515 return off; 1516 1517 case IPPROTO_FRAGMENT: 1518 /* 1519 * terminate parsing if it is not the first fragment, 1520 * it does not make sense to parse through it. 1521 */ 1522 if (m->m_pkthdr.len < off + sizeof(fh)) 1523 return -1; 1524 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1525 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1526 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1527 return -1; 1528 if (nxtp) 1529 *nxtp = fh.ip6f_nxt; 1530 off += sizeof(struct ip6_frag); 1531 return off; 1532 1533 case IPPROTO_AH: 1534 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1535 return -1; 1536 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1537 if (nxtp) 1538 *nxtp = ip6e.ip6e_nxt; 1539 off += (ip6e.ip6e_len + 2) << 2; 1540 return off; 1541 1542 case IPPROTO_HOPOPTS: 1543 case IPPROTO_ROUTING: 1544 case IPPROTO_DSTOPTS: 1545 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1546 return -1; 1547 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1548 if (nxtp) 1549 *nxtp = ip6e.ip6e_nxt; 1550 off += (ip6e.ip6e_len + 1) << 3; 1551 return off; 1552 1553 case IPPROTO_NONE: 1554 case IPPROTO_ESP: 1555 case IPPROTO_IPCOMP: 1556 /* give up */ 1557 return -1; 1558 1559 default: 1560 return -1; 1561 } 1562 1563 return -1; 1564 } 1565 1566 /* 1567 * get offset for the last header in the chain. m will be kept untainted. 1568 */ 1569 int 1570 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1571 { 1572 int newoff; 1573 int nxt; 1574 1575 if (!nxtp) { 1576 nxt = -1; 1577 nxtp = &nxt; 1578 } 1579 while (1) { 1580 newoff = ip6_nexthdr(m, off, proto, nxtp); 1581 if (newoff < 0) 1582 return off; 1583 else if (newoff < off) 1584 return -1; /* invalid */ 1585 else if (newoff == off) 1586 return newoff; 1587 1588 off = newoff; 1589 proto = *nxtp; 1590 } 1591 } 1592 1593 struct ip6aux * 1594 ip6_addaux(struct mbuf *m) 1595 { 1596 struct m_tag *mtag; 1597 1598 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1599 if (!mtag) { 1600 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1601 M_NOWAIT); 1602 if (mtag) 1603 m_tag_prepend(m, mtag); 1604 } 1605 if (mtag) 1606 bzero(m_tag_data(mtag), sizeof(struct ip6aux)); 1607 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1608 } 1609 1610 struct ip6aux * 1611 ip6_findaux(struct mbuf *m) 1612 { 1613 struct m_tag *mtag; 1614 1615 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1616 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1617 } 1618 1619 void 1620 ip6_delaux(struct mbuf *m) 1621 { 1622 struct m_tag *mtag; 1623 1624 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1625 if (mtag) 1626 m_tag_delete(m, mtag); 1627 } 1628 1629 /* 1630 * System control for IP6 1631 */ 1632 1633 u_char inet6ctlerrmap[PRC_NCMDS] = { 1634 0, 0, 0, 0, 1635 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1636 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1637 EMSGSIZE, EHOSTUNREACH, 0, 0, 1638 0, 0, 0, 0, 1639 ENOPROTOOPT 1640 }; 1641