1 /* $FreeBSD: src/sys/netinet6/ip6_input.c,v 1.11.2.15 2003/01/24 05:11:35 sam Exp $ */ 2 /* $DragonFly: src/sys/netinet6/ip6_input.c,v 1.38 2008/09/24 14:26:39 sephe Exp $ */ 3 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 4 5 /* 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1982, 1986, 1988, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 67 */ 68 69 #include "opt_ip6fw.h" 70 #include "opt_inet.h" 71 #include "opt_inet6.h" 72 #include "opt_ipsec.h" 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/malloc.h> 77 #include <sys/mbuf.h> 78 #include <sys/domain.h> 79 #include <sys/protosw.h> 80 #include <sys/socket.h> 81 #include <sys/socketvar.h> 82 #include <sys/errno.h> 83 #include <sys/time.h> 84 #include <sys/kernel.h> 85 #include <sys/syslog.h> 86 #include <sys/proc.h> 87 #include <sys/priv.h> 88 89 #include <sys/thread2.h> 90 #include <sys/msgport2.h> 91 92 #include <net/if.h> 93 #include <net/if_types.h> 94 #include <net/if_dl.h> 95 #include <net/route.h> 96 #include <net/netisr.h> 97 #include <net/pfil.h> 98 99 #include <netinet/in.h> 100 #include <netinet/in_systm.h> 101 #ifdef INET 102 #include <netinet/ip.h> 103 #include <netinet/ip_icmp.h> 104 #endif /* INET */ 105 #include <netinet/ip6.h> 106 #include <netinet6/in6_var.h> 107 #include <netinet6/ip6_var.h> 108 #include <netinet/in_pcb.h> 109 #include <netinet/icmp6.h> 110 #include <netinet6/scope6_var.h> 111 #include <netinet6/in6_ifattach.h> 112 #include <netinet6/nd6.h> 113 #include <netinet6/in6_prefix.h> 114 115 #ifdef IPSEC 116 #include <netinet6/ipsec.h> 117 #ifdef INET6 118 #include <netinet6/ipsec6.h> 119 #endif 120 #endif 121 122 #ifdef FAST_IPSEC 123 #include <netproto/ipsec/ipsec.h> 124 #include <netproto/ipsec/ipsec6.h> 125 #define IPSEC 126 #endif /* FAST_IPSEC */ 127 128 #include <net/ip6fw/ip6_fw.h> 129 130 #include <netinet6/ip6protosw.h> 131 132 /* we need it for NLOOP. */ 133 #include "use_loop.h" 134 135 #include <net/net_osdep.h> 136 137 extern struct domain inet6domain; 138 extern struct ip6protosw inet6sw[]; 139 140 u_char ip6_protox[IPPROTO_MAX]; 141 struct in6_ifaddr *in6_ifaddr; 142 143 extern struct callout in6_tmpaddrtimer_ch; 144 145 int ip6_forward_srcrt; /* XXX */ 146 int ip6_sourcecheck; /* XXX */ 147 int ip6_sourcecheck_interval; /* XXX */ 148 149 int ip6_ours_check_algorithm; 150 151 struct pfil_head inet6_pfil_hook; 152 153 /* firewall hooks */ 154 ip6_fw_chk_t *ip6_fw_chk_ptr; 155 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 156 int ip6_fw_enable = 1; 157 158 struct ip6stat ip6stat; 159 160 static void ip6_init2 (void *); 161 static struct ip6aux *ip6_setdstifaddr (struct mbuf *, struct in6_ifaddr *); 162 static int ip6_hopopts_input (u_int32_t *, u_int32_t *, struct mbuf **, int *); 163 static void ip6_input(struct netmsg *msg); 164 #ifdef PULLDOWN_TEST 165 static struct mbuf *ip6_pullexthdr (struct mbuf *, size_t, int); 166 #endif 167 168 /* 169 * IP6 initialization: fill in IP6 protocol switch table. 170 * All protocols not implemented in kernel go to raw IP6 protocol handler. 171 */ 172 void 173 ip6_init(void) 174 { 175 struct ip6protosw *pr; 176 int i; 177 struct timeval tv; 178 179 #ifdef DIAGNOSTIC 180 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 181 panic("sizeof(protosw) != sizeof(ip6protosw)"); 182 #endif 183 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 184 if (pr == 0) 185 panic("ip6_init"); 186 for (i = 0; i < IPPROTO_MAX; i++) 187 ip6_protox[i] = pr - inet6sw; 188 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 189 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 190 if (pr->pr_domain->dom_family == PF_INET6 && 191 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 192 ip6_protox[pr->pr_protocol] = pr - inet6sw; 193 194 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 195 inet6_pfil_hook.ph_af = AF_INET6; 196 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) { 197 kprintf("%s: WARNING: unable to register pfil hook, " 198 "error %d\n", __func__, i); 199 } 200 201 netisr_register(NETISR_IPV6, cpu0_portfn, ip6_input, 202 NETISR_FLAG_NOTMPSAFE); 203 scope6_init(); 204 nd6_init(); 205 frag6_init(); 206 /* 207 * in many cases, random() here does NOT return random number 208 * as initialization during bootstrap time occur in fixed order. 209 */ 210 microtime(&tv); 211 ip6_flow_seq = krandom() ^ tv.tv_usec; 212 microtime(&tv); 213 ip6_desync_factor = (krandom() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 214 } 215 216 static void 217 ip6_init2(void *dummy) 218 { 219 /* nd6_timer_init */ 220 callout_init(&nd6_timer_ch); 221 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 222 223 /* router renumbering prefix list maintenance */ 224 callout_init(&in6_rr_timer_ch); 225 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 226 227 /* timer for regeneranation of temporary addresses randomize ID */ 228 callout_init(&in6_tmpaddrtimer_ch); 229 callout_reset(&in6_tmpaddrtimer_ch, 230 (ip6_temp_preferred_lifetime - ip6_desync_factor - 231 ip6_temp_regen_advance) * hz, 232 in6_tmpaddrtimer, NULL); 233 } 234 235 /* cheat */ 236 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 237 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 238 239 extern struct route_in6 ip6_forward_rt; 240 241 static 242 void 243 ip6_input(struct netmsg *msg) 244 { 245 struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet; 246 struct ip6_hdr *ip6; 247 int off = sizeof(struct ip6_hdr), nest; 248 u_int32_t plen; 249 u_int32_t rtalert = ~0; 250 int nxt, ours = 0, rh_present = 0; 251 struct ifnet *deliverifp = NULL; 252 struct in6_addr odst; 253 int srcrt = 0; 254 255 #ifdef IPSEC 256 /* 257 * should the inner packet be considered authentic? 258 * see comment in ah4_input(). 259 */ 260 if (m) { 261 m->m_flags &= ~M_AUTHIPHDR; 262 m->m_flags &= ~M_AUTHIPDGM; 263 } 264 #endif 265 266 /* 267 * make sure we don't have onion peering information into m_aux. 268 */ 269 ip6_delaux(m); 270 271 /* 272 * mbuf statistics 273 */ 274 if (m->m_flags & M_EXT) { 275 if (m->m_next) 276 ip6stat.ip6s_mext2m++; 277 else 278 ip6stat.ip6s_mext1++; 279 } else { 280 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 281 if (m->m_next) { 282 if (m->m_flags & M_LOOP) { 283 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 284 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 285 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 286 else 287 ip6stat.ip6s_m2m[0]++; 288 } else 289 ip6stat.ip6s_m1++; 290 #undef M2MMAX 291 } 292 293 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 294 ip6stat.ip6s_total++; 295 296 #ifndef PULLDOWN_TEST 297 /* 298 * L2 bridge code and some other code can return mbuf chain 299 * that does not conform to KAME requirement. too bad. 300 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 301 */ 302 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 303 struct mbuf *n; 304 305 n = m_getb(m->m_pkthdr.len, MB_DONTWAIT, MT_HEADER, M_PKTHDR); 306 if (n == NULL) 307 goto bad; 308 M_MOVE_PKTHDR(n, m); 309 310 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 311 n->m_len = n->m_pkthdr.len; 312 m_freem(m); 313 m = n; 314 } 315 IP6_EXTHDR_CHECK_VOIDRET(m, 0, sizeof(struct ip6_hdr)); 316 #endif 317 318 if (m->m_len < sizeof(struct ip6_hdr)) { 319 struct ifnet *inifp; 320 inifp = m->m_pkthdr.rcvif; 321 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 322 ip6stat.ip6s_toosmall++; 323 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 324 goto bad2; 325 } 326 } 327 328 ip6 = mtod(m, struct ip6_hdr *); 329 330 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 331 ip6stat.ip6s_badvers++; 332 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 333 goto bad; 334 } 335 336 /* 337 * Run through list of hooks for input packets. 338 * 339 * NB: Beware of the destination address changing 340 * (e.g. by NAT rewriting). When this happens, 341 * tell ip6_forward to do the right thing. 342 */ 343 if (pfil_has_hooks(&inet6_pfil_hook)) { 344 odst = ip6->ip6_dst; 345 if (pfil_run_hooks(&inet6_pfil_hook, &m, 346 m->m_pkthdr.rcvif, PFIL_IN)) { 347 goto bad2; 348 } 349 if (m == NULL) /* consumed by filter */ 350 goto bad2; 351 ip6 = mtod(m, struct ip6_hdr *); 352 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 353 } 354 355 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 356 357 #ifdef ALTQ 358 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 359 /* packet is dropped by traffic conditioner */ 360 return; 361 } 362 #endif 363 364 /* 365 * Check with the firewall... 366 */ 367 if (ip6_fw_enable && ip6_fw_chk_ptr) { 368 u_short port = 0; 369 /* If ipfw says divert, we have to just drop packet */ 370 /* use port as a dummy argument */ 371 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 372 m_freem(m); 373 m = NULL; 374 } 375 if (!m) 376 goto bad2; 377 } 378 379 /* 380 * Check against address spoofing/corruption. 381 */ 382 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 383 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 384 /* 385 * XXX: "badscope" is not very suitable for a multicast source. 386 */ 387 ip6stat.ip6s_badscope++; 388 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 389 goto bad; 390 } 391 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 392 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 393 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 394 ip6stat.ip6s_badscope++; 395 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 396 goto bad; 397 } 398 399 /* 400 * The following check is not documented in specs. A malicious 401 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 402 * and bypass security checks (act as if it was from 127.0.0.1 by using 403 * IPv6 src ::ffff:127.0.0.1). Be cautious. 404 * 405 * This check chokes if we are in an SIIT cloud. As none of BSDs 406 * support IPv4-less kernel compilation, we cannot support SIIT 407 * environment at all. So, it makes more sense for us to reject any 408 * malicious packets for non-SIIT environment, than try to do a 409 * partical support for SIIT environment. 410 */ 411 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 412 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 413 ip6stat.ip6s_badscope++; 414 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 415 goto bad; 416 } 417 #if 0 418 /* 419 * Reject packets with IPv4 compatible addresses (auto tunnel). 420 * 421 * The code forbids auto tunnel relay case in RFC1933 (the check is 422 * stronger than RFC1933). We may want to re-enable it if mech-xx 423 * is revised to forbid relaying case. 424 */ 425 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 426 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 427 ip6stat.ip6s_badscope++; 428 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 429 goto bad; 430 } 431 #endif 432 433 /* drop packets if interface ID portion is already filled */ 434 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 435 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 436 ip6->ip6_src.s6_addr16[1]) { 437 ip6stat.ip6s_badscope++; 438 goto bad; 439 } 440 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 441 ip6->ip6_dst.s6_addr16[1]) { 442 ip6stat.ip6s_badscope++; 443 goto bad; 444 } 445 } 446 447 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 448 ip6->ip6_src.s6_addr16[1] 449 = htons(m->m_pkthdr.rcvif->if_index); 450 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 451 ip6->ip6_dst.s6_addr16[1] 452 = htons(m->m_pkthdr.rcvif->if_index); 453 454 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 455 /* 456 * We use rt->rt_ifp to determine if the address is ours or not. 457 * If rt_ifp is lo0, the address is ours. 458 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 459 * so any address under fe80::%lo0/64 will be mistakenly considered 460 * local. The special case is supplied to handle the case properly 461 * by actually looking at interface addresses 462 * (using in6ifa_ifpwithaddr). 463 */ 464 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) && 465 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 466 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 467 icmp6_error(m, ICMP6_DST_UNREACH, 468 ICMP6_DST_UNREACH_ADDR, 0); 469 /* m is already freed */ 470 goto bad2; 471 } 472 473 ours = 1; 474 deliverifp = m->m_pkthdr.rcvif; 475 goto hbhcheck; 476 } 477 #endif 478 479 /* 480 * Multicast check 481 */ 482 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 483 struct in6_multi *in6m = 0; 484 485 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 486 /* 487 * See if we belong to the destination multicast group on the 488 * arrival interface. 489 */ 490 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 491 if (in6m) 492 ours = 1; 493 else if (!ip6_mrouter) { 494 ip6stat.ip6s_notmember++; 495 ip6stat.ip6s_cantforward++; 496 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 497 goto bad; 498 } 499 deliverifp = m->m_pkthdr.rcvif; 500 goto hbhcheck; 501 } 502 503 /* 504 * Unicast check 505 */ 506 switch (ip6_ours_check_algorithm) { 507 default: 508 /* 509 * XXX: I intentionally broke our indentation rule here, 510 * since this switch-case is just for measurement and 511 * therefore should soon be removed. 512 */ 513 if (ip6_forward_rt.ro_rt != NULL && 514 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) && 515 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 516 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 517 ip6stat.ip6s_forward_cachehit++; 518 else { 519 struct sockaddr_in6 *dst6; 520 521 if (ip6_forward_rt.ro_rt) { 522 /* route is down or destination is different */ 523 ip6stat.ip6s_forward_cachemiss++; 524 RTFREE(ip6_forward_rt.ro_rt); 525 ip6_forward_rt.ro_rt = 0; 526 } 527 528 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 529 dst6 = &ip6_forward_rt.ro_dst; 530 dst6->sin6_len = sizeof(struct sockaddr_in6); 531 dst6->sin6_family = AF_INET6; 532 dst6->sin6_addr = ip6->ip6_dst; 533 534 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 535 } 536 537 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 538 539 /* 540 * Accept the packet if the forwarding interface to the destination 541 * according to the routing table is the loopback interface, 542 * unless the associated route has a gateway. 543 * Note that this approach causes to accept a packet if there is a 544 * route to the loopback interface for the destination of the packet. 545 * But we think it's even useful in some situations, e.g. when using 546 * a special daemon which wants to intercept the packet. 547 * 548 * XXX: some OSes automatically make a cloned route for the destination 549 * of an outgoing packet. If the outgoing interface of the packet 550 * is a loopback one, the kernel would consider the packet to be 551 * accepted, even if we have no such address assinged on the interface. 552 * We check the cloned flag of the route entry to reject such cases, 553 * assuming that route entries for our own addresses are not made by 554 * cloning (it should be true because in6_addloop explicitly installs 555 * the host route). However, we might have to do an explicit check 556 * while it would be less efficient. Or, should we rather install a 557 * reject route for such a case? 558 */ 559 if (ip6_forward_rt.ro_rt && 560 (ip6_forward_rt.ro_rt->rt_flags & 561 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 562 #ifdef RTF_WASCLONED 563 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 564 #endif 565 #ifdef RTF_CLONED 566 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 567 #endif 568 #if 0 569 /* 570 * The check below is redundant since the comparison of 571 * the destination and the key of the rtentry has 572 * already done through looking up the routing table. 573 */ 574 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 575 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 576 #endif 577 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 578 struct in6_ifaddr *ia6 = 579 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 580 581 /* 582 * record address information into m_aux. 583 */ 584 ip6_setdstifaddr(m, ia6); 585 586 /* 587 * packets to a tentative, duplicated, or somehow invalid 588 * address must not be accepted. 589 */ 590 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 591 /* this address is ready */ 592 ours = 1; 593 deliverifp = ia6->ia_ifp; /* correct? */ 594 /* Count the packet in the ip address stats */ 595 ia6->ia_ifa.if_ipackets++; 596 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 597 goto hbhcheck; 598 } else { 599 /* address is not ready, so discard the packet. */ 600 nd6log((LOG_INFO, 601 "ip6_input: packet to an unready address %s->%s\n", 602 ip6_sprintf(&ip6->ip6_src), 603 ip6_sprintf(&ip6->ip6_dst))); 604 605 goto bad; 606 } 607 } 608 } /* XXX indentation (see above) */ 609 610 /* 611 * FAITH(Firewall Aided Internet Translator) 612 */ 613 if (ip6_keepfaith) { 614 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 615 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 616 /* XXX do we need more sanity checks? */ 617 ours = 1; 618 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 619 goto hbhcheck; 620 } 621 } 622 623 /* 624 * Now there is no reason to process the packet if it's not our own 625 * and we're not a router. 626 */ 627 if (!ip6_forwarding) { 628 ip6stat.ip6s_cantforward++; 629 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 630 goto bad; 631 } 632 633 hbhcheck: 634 /* 635 * record address information into m_aux, if we don't have one yet. 636 * note that we are unable to record it, if the address is not listed 637 * as our interface address (e.g. multicast addresses, addresses 638 * within FAITH prefixes and such). 639 */ 640 if (deliverifp && !ip6_getdstifaddr(m)) { 641 struct in6_ifaddr *ia6; 642 643 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 644 if (ia6) { 645 if (!ip6_setdstifaddr(m, ia6)) { 646 /* 647 * XXX maybe we should drop the packet here, 648 * as we could not provide enough information 649 * to the upper layers. 650 */ 651 } 652 } 653 } 654 655 /* 656 * Process Hop-by-Hop options header if it's contained. 657 * m may be modified in ip6_hopopts_input(). 658 * If a JumboPayload option is included, plen will also be modified. 659 */ 660 plen = (u_int32_t)ntohs(ip6->ip6_plen); 661 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 662 struct ip6_hbh *hbh; 663 664 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 665 #if 0 /*touches NULL pointer*/ 666 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 667 #endif 668 goto bad2; /* m have already been freed */ 669 } 670 671 /* adjust pointer */ 672 ip6 = mtod(m, struct ip6_hdr *); 673 674 /* 675 * if the payload length field is 0 and the next header field 676 * indicates Hop-by-Hop Options header, then a Jumbo Payload 677 * option MUST be included. 678 */ 679 if (ip6->ip6_plen == 0 && plen == 0) { 680 /* 681 * Note that if a valid jumbo payload option is 682 * contained, ip6_hoptops_input() must set a valid 683 * (non-zero) payload length to the variable plen. 684 */ 685 ip6stat.ip6s_badoptions++; 686 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 687 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 688 icmp6_error(m, ICMP6_PARAM_PROB, 689 ICMP6_PARAMPROB_HEADER, 690 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 691 goto bad2; 692 } 693 #ifndef PULLDOWN_TEST 694 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 695 hbh = (struct ip6_hbh *)(ip6 + 1); 696 #else 697 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 698 sizeof(struct ip6_hbh)); 699 if (hbh == NULL) { 700 ip6stat.ip6s_tooshort++; 701 goto bad2; 702 } 703 #endif 704 nxt = hbh->ip6h_nxt; 705 706 /* 707 * If we are acting as a router and the packet contains a 708 * router alert option, see if we know the option value. 709 * Currently, we only support the option value for MLD, in which 710 * case we should pass the packet to the multicast routing 711 * daemon. 712 */ 713 if (rtalert != ~0 && ip6_forwarding) { 714 switch (rtalert) { 715 case IP6OPT_RTALERT_MLD: 716 ours = 1; 717 break; 718 default: 719 /* 720 * RFC2711 requires unrecognized values must be 721 * silently ignored. 722 */ 723 break; 724 } 725 } 726 } else 727 nxt = ip6->ip6_nxt; 728 729 /* 730 * Check that the amount of data in the buffers 731 * is as at least much as the IPv6 header would have us expect. 732 * Trim mbufs if longer than we expect. 733 * Drop packet if shorter than we expect. 734 */ 735 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 736 ip6stat.ip6s_tooshort++; 737 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 738 goto bad; 739 } 740 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 741 if (m->m_len == m->m_pkthdr.len) { 742 m->m_len = sizeof(struct ip6_hdr) + plen; 743 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 744 } else 745 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 746 } 747 748 /* 749 * Forward if desirable. 750 */ 751 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 752 /* 753 * If we are acting as a multicast router, all 754 * incoming multicast packets are passed to the 755 * kernel-level multicast forwarding function. 756 * The packet is returned (relatively) intact; if 757 * ip6_mforward() returns a non-zero value, the packet 758 * must be discarded, else it may be accepted below. 759 */ 760 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 761 ip6stat.ip6s_cantforward++; 762 goto bad; 763 } 764 if (!ours) 765 goto bad; 766 } else if (!ours) { 767 ip6_forward(m, srcrt); 768 goto bad2; 769 } 770 771 ip6 = mtod(m, struct ip6_hdr *); 772 773 /* 774 * Malicious party may be able to use IPv4 mapped addr to confuse 775 * tcp/udp stack and bypass security checks (act as if it was from 776 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 777 * 778 * For SIIT end node behavior, you may want to disable the check. 779 * However, you will become vulnerable to attacks using IPv4 mapped 780 * source. 781 */ 782 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 783 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 784 ip6stat.ip6s_badscope++; 785 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 786 goto bad; 787 } 788 789 /* 790 * Tell launch routine the next header 791 */ 792 ip6stat.ip6s_delivered++; 793 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 794 nest = 0; 795 796 rh_present = 0; 797 while (nxt != IPPROTO_DONE) { 798 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 799 ip6stat.ip6s_toomanyhdr++; 800 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 801 goto bad; 802 } 803 804 /* 805 * protection against faulty packet - there should be 806 * more sanity checks in header chain processing. 807 */ 808 if (m->m_pkthdr.len < off) { 809 ip6stat.ip6s_tooshort++; 810 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 811 goto bad; 812 } 813 814 #if 0 815 /* 816 * do we need to do it for every header? yeah, other 817 * functions can play with it (like re-allocate and copy). 818 */ 819 mhist = ip6_addaux(m); 820 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 821 hist = mtod(mhist, caddr_t) + mhist->m_len; 822 bcopy(&nxt, hist, sizeof(nxt)); 823 mhist->m_len += sizeof(nxt); 824 } else { 825 ip6stat.ip6s_toomanyhdr++; 826 goto bad; 827 } 828 #endif 829 830 if (nxt == IPPROTO_ROUTING) { 831 if (rh_present++) { 832 in6_ifstat_inc(m->m_pkthdr.rcvif, 833 ifs6_in_hdrerr); 834 ip6stat.ip6s_badoptions++; 835 goto bad; 836 } 837 } 838 839 #ifdef IPSEC 840 /* 841 * enforce IPsec policy checking if we are seeing last header. 842 * note that we do not visit this with protocols with pcb layer 843 * code - like udp/tcp/raw ip. 844 */ 845 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) && 846 ipsec6_in_reject(m, NULL)) { 847 ipsec6stat.in_polvio++; 848 goto bad; 849 } 850 #endif 851 852 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 853 } 854 goto bad2; 855 bad: 856 m_freem(m); 857 bad2: 858 ; 859 /* msg was embedded in the mbuf, do not reply! */ 860 } 861 862 /* 863 * set/grab in6_ifaddr correspond to IPv6 destination address. 864 * XXX backward compatibility wrapper 865 */ 866 static struct ip6aux * 867 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 868 { 869 struct ip6aux *n; 870 871 n = ip6_addaux(m); 872 if (n) 873 n->ip6a_dstia6 = ia6; 874 return n; /* NULL if failed to set */ 875 } 876 877 struct in6_ifaddr * 878 ip6_getdstifaddr(struct mbuf *m) 879 { 880 struct ip6aux *n; 881 882 n = ip6_findaux(m); 883 if (n) 884 return n->ip6a_dstia6; 885 else 886 return NULL; 887 } 888 889 /* 890 * Hop-by-Hop options header processing. If a valid jumbo payload option is 891 * included, the real payload length will be stored in plenp. 892 */ 893 static int 894 ip6_hopopts_input(u_int32_t *plenp, 895 u_int32_t *rtalertp,/* XXX: should be stored more smart way */ 896 struct mbuf **mp, 897 int *offp) 898 { 899 struct mbuf *m = *mp; 900 int off = *offp, hbhlen; 901 struct ip6_hbh *hbh; 902 u_int8_t *opt; 903 904 /* validation of the length of the header */ 905 #ifndef PULLDOWN_TEST 906 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 907 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 908 hbhlen = (hbh->ip6h_len + 1) << 3; 909 910 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 911 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 912 #else 913 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 914 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 915 if (hbh == NULL) { 916 ip6stat.ip6s_tooshort++; 917 return -1; 918 } 919 hbhlen = (hbh->ip6h_len + 1) << 3; 920 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 921 hbhlen); 922 if (hbh == NULL) { 923 ip6stat.ip6s_tooshort++; 924 return -1; 925 } 926 #endif 927 off += hbhlen; 928 hbhlen -= sizeof(struct ip6_hbh); 929 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 930 931 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 932 hbhlen, rtalertp, plenp) < 0) 933 return (-1); 934 935 *offp = off; 936 *mp = m; 937 return (0); 938 } 939 940 /* 941 * Search header for all Hop-by-hop options and process each option. 942 * This function is separate from ip6_hopopts_input() in order to 943 * handle a case where the sending node itself process its hop-by-hop 944 * options header. In such a case, the function is called from ip6_output(). 945 * 946 * The function assumes that hbh header is located right after the IPv6 header 947 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 948 * opthead + hbhlen is located in continuous memory region. 949 */ 950 int 951 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 952 u_int32_t *rtalertp, u_int32_t *plenp) 953 { 954 struct ip6_hdr *ip6; 955 int optlen = 0; 956 u_int8_t *opt = opthead; 957 u_int16_t rtalert_val; 958 u_int32_t jumboplen; 959 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 960 961 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 962 switch (*opt) { 963 case IP6OPT_PAD1: 964 optlen = 1; 965 break; 966 case IP6OPT_PADN: 967 if (hbhlen < IP6OPT_MINLEN) { 968 ip6stat.ip6s_toosmall++; 969 goto bad; 970 } 971 optlen = *(opt + 1) + 2; 972 break; 973 case IP6OPT_RTALERT: 974 /* XXX may need check for alignment */ 975 if (hbhlen < IP6OPT_RTALERT_LEN) { 976 ip6stat.ip6s_toosmall++; 977 goto bad; 978 } 979 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 980 /* XXX stat */ 981 icmp6_error(m, ICMP6_PARAM_PROB, 982 ICMP6_PARAMPROB_HEADER, 983 erroff + opt + 1 - opthead); 984 return (-1); 985 } 986 optlen = IP6OPT_RTALERT_LEN; 987 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 988 *rtalertp = ntohs(rtalert_val); 989 break; 990 case IP6OPT_JUMBO: 991 /* XXX may need check for alignment */ 992 if (hbhlen < IP6OPT_JUMBO_LEN) { 993 ip6stat.ip6s_toosmall++; 994 goto bad; 995 } 996 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 997 /* XXX stat */ 998 icmp6_error(m, ICMP6_PARAM_PROB, 999 ICMP6_PARAMPROB_HEADER, 1000 erroff + opt + 1 - opthead); 1001 return (-1); 1002 } 1003 optlen = IP6OPT_JUMBO_LEN; 1004 1005 /* 1006 * IPv6 packets that have non 0 payload length 1007 * must not contain a jumbo payload option. 1008 */ 1009 ip6 = mtod(m, struct ip6_hdr *); 1010 if (ip6->ip6_plen) { 1011 ip6stat.ip6s_badoptions++; 1012 icmp6_error(m, ICMP6_PARAM_PROB, 1013 ICMP6_PARAMPROB_HEADER, 1014 erroff + opt - opthead); 1015 return (-1); 1016 } 1017 1018 /* 1019 * We may see jumbolen in unaligned location, so 1020 * we'd need to perform bcopy(). 1021 */ 1022 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1023 jumboplen = (u_int32_t)htonl(jumboplen); 1024 1025 #if 1 1026 /* 1027 * if there are multiple jumbo payload options, 1028 * *plenp will be non-zero and the packet will be 1029 * rejected. 1030 * the behavior may need some debate in ipngwg - 1031 * multiple options does not make sense, however, 1032 * there's no explicit mention in specification. 1033 */ 1034 if (*plenp != 0) { 1035 ip6stat.ip6s_badoptions++; 1036 icmp6_error(m, ICMP6_PARAM_PROB, 1037 ICMP6_PARAMPROB_HEADER, 1038 erroff + opt + 2 - opthead); 1039 return (-1); 1040 } 1041 #endif 1042 1043 /* 1044 * jumbo payload length must be larger than 65535. 1045 */ 1046 if (jumboplen <= IPV6_MAXPACKET) { 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 *plenp = jumboplen; 1054 1055 break; 1056 default: /* unknown option */ 1057 if (hbhlen < IP6OPT_MINLEN) { 1058 ip6stat.ip6s_toosmall++; 1059 goto bad; 1060 } 1061 optlen = ip6_unknown_opt(opt, m, 1062 erroff + opt - opthead); 1063 if (optlen == -1) 1064 return (-1); 1065 optlen += 2; 1066 break; 1067 } 1068 } 1069 1070 return (0); 1071 1072 bad: 1073 m_freem(m); 1074 return (-1); 1075 } 1076 1077 /* 1078 * Unknown option processing. 1079 * The third argument `off' is the offset from the IPv6 header to the option, 1080 * which is necessary if the IPv6 header the and option header and IPv6 header 1081 * is not continuous in order to return an ICMPv6 error. 1082 */ 1083 int 1084 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1085 { 1086 struct ip6_hdr *ip6; 1087 1088 switch (IP6OPT_TYPE(*optp)) { 1089 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1090 return ((int)*(optp + 1)); 1091 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1092 m_freem(m); 1093 return (-1); 1094 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1095 ip6stat.ip6s_badoptions++; 1096 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1097 return (-1); 1098 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1099 ip6stat.ip6s_badoptions++; 1100 ip6 = mtod(m, struct ip6_hdr *); 1101 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1102 (m->m_flags & (M_BCAST|M_MCAST))) 1103 m_freem(m); 1104 else 1105 icmp6_error(m, ICMP6_PARAM_PROB, 1106 ICMP6_PARAMPROB_OPTION, off); 1107 return (-1); 1108 } 1109 1110 m_freem(m); /* XXX: NOTREACHED */ 1111 return (-1); 1112 } 1113 1114 /* 1115 * Create the "control" list for this pcb. 1116 * The function will not modify mbuf chain at all. 1117 * 1118 * with KAME mbuf chain restriction: 1119 * The routine will be called from upper layer handlers like tcp6_input(). 1120 * Thus the routine assumes that the caller (tcp6_input) have already 1121 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1122 * very first mbuf on the mbuf chain. 1123 */ 1124 void 1125 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6, 1126 struct mbuf *m) 1127 { 1128 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1129 struct thread *td = curthread; /* XXX */ 1130 int privileged = 0; 1131 int rthdr_exist = 0; 1132 1133 1134 if (priv_check(td, PRIV_ROOT) == 0) 1135 privileged++; 1136 1137 #ifdef SO_TIMESTAMP 1138 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1139 struct timeval tv; 1140 1141 microtime(&tv); 1142 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1143 SCM_TIMESTAMP, SOL_SOCKET); 1144 if (*mp) { 1145 mp = &(*mp)->m_next; 1146 } 1147 } 1148 #endif 1149 1150 /* RFC 2292 sec. 5 */ 1151 if (in6p->in6p_flags & IN6P_PKTINFO) { 1152 struct in6_pktinfo pi6; 1153 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1154 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1155 pi6.ipi6_addr.s6_addr16[1] = 0; 1156 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1157 ? m->m_pkthdr.rcvif->if_index 1158 : 0; 1159 *mp = sbcreatecontrol((caddr_t) &pi6, 1160 sizeof(struct in6_pktinfo), IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), 1161 IPPROTO_IPV6); 1162 if (*mp) 1163 mp = &(*mp)->m_next; 1164 } 1165 1166 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1167 int hlim = ip6->ip6_hlim & 0xff; 1168 *mp = sbcreatecontrol((caddr_t) &hlim, 1169 sizeof(int), IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1170 if (*mp) 1171 mp = &(*mp)->m_next; 1172 } 1173 1174 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1175 u_int32_t flowinfo; 1176 int tclass; 1177 1178 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1179 flowinfo >>= 20; 1180 1181 tclass = flowinfo & 0xff; 1182 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1183 IPV6_TCLASS, IPPROTO_IPV6); 1184 if (*mp) 1185 mp = &(*mp)->m_next; 1186 } 1187 1188 /* 1189 * IPV6_HOPOPTS socket option. We require super-user privilege 1190 * for the option, but it might be too strict, since there might 1191 * be some hop-by-hop options which can be returned to normal user. 1192 * See RFC 2292 section 6. 1193 */ 1194 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1195 /* 1196 * Check if a hop-by-hop options header is contatined in the 1197 * received packet, and if so, store the options as ancillary 1198 * data. Note that a hop-by-hop options header must be 1199 * just after the IPv6 header, which fact is assured through 1200 * the IPv6 input processing. 1201 */ 1202 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1203 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1204 struct ip6_hbh *hbh; 1205 int hbhlen = 0; 1206 #ifdef PULLDOWN_TEST 1207 struct mbuf *ext; 1208 #endif 1209 1210 #ifndef PULLDOWN_TEST 1211 hbh = (struct ip6_hbh *)(ip6 + 1); 1212 hbhlen = (hbh->ip6h_len + 1) << 3; 1213 #else 1214 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1215 ip6->ip6_nxt); 1216 if (ext == NULL) { 1217 ip6stat.ip6s_tooshort++; 1218 return; 1219 } 1220 hbh = mtod(ext, struct ip6_hbh *); 1221 hbhlen = (hbh->ip6h_len + 1) << 3; 1222 if (hbhlen != ext->m_len) { 1223 m_freem(ext); 1224 ip6stat.ip6s_tooshort++; 1225 return; 1226 } 1227 #endif 1228 1229 /* 1230 * XXX: We copy whole the header even if a jumbo 1231 * payload option is included, which option is to 1232 * be removed before returning in the RFC 2292. 1233 * Note: this constraint is removed in 2292bis. 1234 */ 1235 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1236 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), IPPROTO_IPV6); 1237 if (*mp) 1238 mp = &(*mp)->m_next; 1239 #ifdef PULLDOWN_TEST 1240 m_freem(ext); 1241 #endif 1242 } 1243 } 1244 1245 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1246 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1247 int proto, off, nxt; 1248 1249 /* 1250 * go through the header chain to see if a routing header is 1251 * contained in the packet. We need this information to store 1252 * destination options headers (if any) properly. 1253 * XXX: performance issue. We should record this info when 1254 * processing extension headers in incoming routine. 1255 * (todo) use m_aux? 1256 */ 1257 proto = IPPROTO_IPV6; 1258 off = 0; 1259 nxt = -1; 1260 while (1) { 1261 int newoff; 1262 1263 newoff = ip6_nexthdr(m, off, proto, &nxt); 1264 if (newoff < 0) 1265 break; 1266 if (newoff < off) /* invalid, check for safety */ 1267 break; 1268 if ((proto = nxt) == IPPROTO_ROUTING) { 1269 rthdr_exist = 1; 1270 break; 1271 } 1272 off = newoff; 1273 } 1274 } 1275 1276 if ((in6p->in6p_flags & 1277 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1278 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1279 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1280 1281 /* 1282 * Search for destination options headers or routing 1283 * header(s) through the header chain, and stores each 1284 * header as ancillary data. 1285 * Note that the order of the headers remains in 1286 * the chain of ancillary data. 1287 */ 1288 while (1) { /* is explicit loop prevention necessary? */ 1289 struct ip6_ext *ip6e = NULL; 1290 int elen; 1291 #ifdef PULLDOWN_TEST 1292 struct mbuf *ext = NULL; 1293 #endif 1294 1295 /* 1296 * if it is not an extension header, don't try to 1297 * pull it from the chain. 1298 */ 1299 switch (nxt) { 1300 case IPPROTO_DSTOPTS: 1301 case IPPROTO_ROUTING: 1302 case IPPROTO_HOPOPTS: 1303 case IPPROTO_AH: /* is it possible? */ 1304 break; 1305 default: 1306 goto loopend; 1307 } 1308 1309 #ifndef PULLDOWN_TEST 1310 if (off + sizeof(*ip6e) > m->m_len) 1311 goto loopend; 1312 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1313 if (nxt == IPPROTO_AH) 1314 elen = (ip6e->ip6e_len + 2) << 2; 1315 else 1316 elen = (ip6e->ip6e_len + 1) << 3; 1317 if (off + elen > m->m_len) 1318 goto loopend; 1319 #else 1320 ext = ip6_pullexthdr(m, off, nxt); 1321 if (ext == NULL) { 1322 ip6stat.ip6s_tooshort++; 1323 return; 1324 } 1325 ip6e = mtod(ext, struct ip6_ext *); 1326 if (nxt == IPPROTO_AH) 1327 elen = (ip6e->ip6e_len + 2) << 2; 1328 else 1329 elen = (ip6e->ip6e_len + 1) << 3; 1330 if (elen != ext->m_len) { 1331 m_freem(ext); 1332 ip6stat.ip6s_tooshort++; 1333 return; 1334 } 1335 #endif 1336 1337 switch (nxt) { 1338 case IPPROTO_DSTOPTS: 1339 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1340 break; 1341 1342 /* 1343 * We also require super-user privilege for 1344 * the option. 1345 * See the comments on IN6_HOPOPTS. 1346 */ 1347 if (!privileged) 1348 break; 1349 1350 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1351 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1352 IPPROTO_IPV6); 1353 if (*mp) 1354 mp = &(*mp)->m_next; 1355 break; 1356 case IPPROTO_ROUTING: 1357 if (!in6p->in6p_flags & IN6P_RTHDR) 1358 break; 1359 1360 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1361 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1362 IPPROTO_IPV6); 1363 if (*mp) 1364 mp = &(*mp)->m_next; 1365 break; 1366 case IPPROTO_HOPOPTS: 1367 case IPPROTO_AH: /* is it possible? */ 1368 break; 1369 1370 default: 1371 /* 1372 * other cases have been filtered in the above. 1373 * none will visit this case. here we supply 1374 * the code just in case (nxt overwritten or 1375 * other cases). 1376 */ 1377 #ifdef PULLDOWN_TEST 1378 m_freem(ext); 1379 #endif 1380 goto loopend; 1381 1382 } 1383 1384 /* proceed with the next header. */ 1385 off += elen; 1386 nxt = ip6e->ip6e_nxt; 1387 ip6e = NULL; 1388 #ifdef PULLDOWN_TEST 1389 m_freem(ext); 1390 ext = NULL; 1391 #endif 1392 } 1393 loopend: 1394 ; 1395 } 1396 #undef IS2292 1397 } 1398 1399 void 1400 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1401 { 1402 struct socket *so; 1403 struct mbuf *m_mtu; 1404 struct ip6_mtuinfo mtuctl; 1405 1406 so = in6p->inp_socket; 1407 1408 if (mtu == NULL) 1409 return; 1410 1411 #ifdef DIAGNOSTIC 1412 if (so == NULL) /* I believe this is impossible */ 1413 panic("ip6_notify_pmtu: socket is NULL"); 1414 #endif 1415 1416 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1417 mtuctl.ip6m_mtu = *mtu; 1418 mtuctl.ip6m_addr = *dst; 1419 1420 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1421 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1422 return; 1423 1424 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1425 == 0) { 1426 m_freem(m_mtu); 1427 /* XXX: should count statistics */ 1428 } else 1429 sorwakeup(so); 1430 1431 return; 1432 } 1433 1434 #ifdef PULLDOWN_TEST 1435 /* 1436 * pull single extension header from mbuf chain. returns single mbuf that 1437 * contains the result, or NULL on error. 1438 */ 1439 static struct mbuf * 1440 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1441 { 1442 struct ip6_ext ip6e; 1443 size_t elen; 1444 struct mbuf *n; 1445 1446 #ifdef DIAGNOSTIC 1447 switch (nxt) { 1448 case IPPROTO_DSTOPTS: 1449 case IPPROTO_ROUTING: 1450 case IPPROTO_HOPOPTS: 1451 case IPPROTO_AH: /* is it possible? */ 1452 break; 1453 default: 1454 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1455 } 1456 #endif 1457 1458 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1459 if (nxt == IPPROTO_AH) 1460 elen = (ip6e.ip6e_len + 2) << 2; 1461 else 1462 elen = (ip6e.ip6e_len + 1) << 3; 1463 1464 n = m_getb(elen, MB_DONTWAIT, MT_DATA, 0); 1465 if (n == NULL) 1466 return NULL; 1467 n->m_len = 0; 1468 1469 if (elen >= M_TRAILINGSPACE(n)) { 1470 m_free(n); 1471 return NULL; 1472 } 1473 1474 m_copydata(m, off, elen, mtod(n, caddr_t)); 1475 n->m_len = elen; 1476 return n; 1477 } 1478 #endif 1479 1480 /* 1481 * Get pointer to the previous header followed by the header 1482 * currently processed. 1483 * XXX: This function supposes that 1484 * M includes all headers, 1485 * the next header field and the header length field of each header 1486 * are valid, and 1487 * the sum of each header length equals to OFF. 1488 * Because of these assumptions, this function must be called very 1489 * carefully. Moreover, it will not be used in the near future when 1490 * we develop `neater' mechanism to process extension headers. 1491 */ 1492 char * 1493 ip6_get_prevhdr(struct mbuf *m, int off) 1494 { 1495 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1496 1497 if (off == sizeof(struct ip6_hdr)) 1498 return (&ip6->ip6_nxt); 1499 else { 1500 int len, nxt; 1501 struct ip6_ext *ip6e = NULL; 1502 1503 nxt = ip6->ip6_nxt; 1504 len = sizeof(struct ip6_hdr); 1505 while (len < off) { 1506 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1507 1508 switch (nxt) { 1509 case IPPROTO_FRAGMENT: 1510 len += sizeof(struct ip6_frag); 1511 break; 1512 case IPPROTO_AH: 1513 len += (ip6e->ip6e_len + 2) << 2; 1514 break; 1515 default: 1516 len += (ip6e->ip6e_len + 1) << 3; 1517 break; 1518 } 1519 nxt = ip6e->ip6e_nxt; 1520 } 1521 if (ip6e) 1522 return (&ip6e->ip6e_nxt); 1523 else 1524 return NULL; 1525 } 1526 } 1527 1528 /* 1529 * get next header offset. m will be retained. 1530 */ 1531 int 1532 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1533 { 1534 struct ip6_hdr ip6; 1535 struct ip6_ext ip6e; 1536 struct ip6_frag fh; 1537 1538 /* just in case */ 1539 if (m == NULL) 1540 panic("ip6_nexthdr: m == NULL"); 1541 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1542 return -1; 1543 1544 switch (proto) { 1545 case IPPROTO_IPV6: 1546 if (m->m_pkthdr.len < off + sizeof(ip6)) 1547 return -1; 1548 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1549 if (nxtp) 1550 *nxtp = ip6.ip6_nxt; 1551 off += sizeof(ip6); 1552 return off; 1553 1554 case IPPROTO_FRAGMENT: 1555 /* 1556 * terminate parsing if it is not the first fragment, 1557 * it does not make sense to parse through it. 1558 */ 1559 if (m->m_pkthdr.len < off + sizeof(fh)) 1560 return -1; 1561 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1562 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1563 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1564 return -1; 1565 if (nxtp) 1566 *nxtp = fh.ip6f_nxt; 1567 off += sizeof(struct ip6_frag); 1568 return off; 1569 1570 case IPPROTO_AH: 1571 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1572 return -1; 1573 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1574 if (nxtp) 1575 *nxtp = ip6e.ip6e_nxt; 1576 off += (ip6e.ip6e_len + 2) << 2; 1577 return off; 1578 1579 case IPPROTO_HOPOPTS: 1580 case IPPROTO_ROUTING: 1581 case IPPROTO_DSTOPTS: 1582 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1583 return -1; 1584 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1585 if (nxtp) 1586 *nxtp = ip6e.ip6e_nxt; 1587 off += (ip6e.ip6e_len + 1) << 3; 1588 return off; 1589 1590 case IPPROTO_NONE: 1591 case IPPROTO_ESP: 1592 case IPPROTO_IPCOMP: 1593 /* give up */ 1594 return -1; 1595 1596 default: 1597 return -1; 1598 } 1599 1600 return -1; 1601 } 1602 1603 /* 1604 * get offset for the last header in the chain. m will be kept untainted. 1605 */ 1606 int 1607 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1608 { 1609 int newoff; 1610 int nxt; 1611 1612 if (!nxtp) { 1613 nxt = -1; 1614 nxtp = &nxt; 1615 } 1616 while (1) { 1617 newoff = ip6_nexthdr(m, off, proto, nxtp); 1618 if (newoff < 0) 1619 return off; 1620 else if (newoff < off) 1621 return -1; /* invalid */ 1622 else if (newoff == off) 1623 return newoff; 1624 1625 off = newoff; 1626 proto = *nxtp; 1627 } 1628 } 1629 1630 struct ip6aux * 1631 ip6_addaux(struct mbuf *m) 1632 { 1633 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1634 if (!tag) { 1635 tag = m_tag_get(PACKET_TAG_IPV6_INPUT, 1636 sizeof (struct ip6aux), 1637 MB_DONTWAIT); 1638 if (tag) 1639 m_tag_prepend(m, tag); 1640 } 1641 if (tag) 1642 bzero(m_tag_data(tag), sizeof (struct ip6aux)); 1643 return tag ? (struct ip6aux *)m_tag_data(tag) : NULL; 1644 } 1645 1646 struct ip6aux * 1647 ip6_findaux(struct mbuf *m) 1648 { 1649 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1650 return tag ? (struct ip6aux*)(tag+1) : NULL; 1651 } 1652 1653 void 1654 ip6_delaux(struct mbuf *m) 1655 { 1656 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1657 if (tag) 1658 m_tag_delete(m, tag); 1659 } 1660 1661 /* 1662 * System control for IP6 1663 */ 1664 1665 u_char inet6ctlerrmap[PRC_NCMDS] = { 1666 0, 0, 0, 0, 1667 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1668 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1669 EMSGSIZE, EHOSTUNREACH, 0, 0, 1670 0, 0, 0, 0, 1671 ENOPROTOOPT 1672 }; 1673