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. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 66 */ 67 68 #include "opt_ip6fw.h" 69 #include "opt_inet.h" 70 #include "opt_inet6.h" 71 #include "opt_ipsec.h" 72 73 #include <sys/param.h> 74 #include <sys/systm.h> 75 #include <sys/malloc.h> 76 #include <sys/mbuf.h> 77 #include <sys/domain.h> 78 #include <sys/protosw.h> 79 #include <sys/socket.h> 80 #include <sys/socketvar.h> 81 #include <sys/errno.h> 82 #include <sys/time.h> 83 #include <sys/kernel.h> 84 #include <sys/syslog.h> 85 #include <sys/proc.h> 86 #include <sys/priv.h> 87 88 #include <net/if.h> 89 #include <net/if_types.h> 90 #include <net/if_dl.h> 91 #include <net/route.h> 92 #include <net/netisr.h> 93 #include <net/pfil.h> 94 95 #include <sys/thread2.h> 96 #include <sys/msgport2.h> 97 #include <net/netmsg2.h> 98 #include <net/netisr2.h> 99 100 #include <netinet/in.h> 101 #include <netinet/in_systm.h> 102 #ifdef INET 103 #include <netinet/ip.h> 104 #include <netinet/ip_icmp.h> 105 #endif /* INET */ 106 #include <netinet/ip6.h> 107 #include <netinet6/in6_var.h> 108 #include <netinet6/ip6_var.h> 109 #include <netinet/in_pcb.h> 110 #include <netinet/icmp6.h> 111 #include <netinet6/scope6_var.h> 112 #include <netinet6/in6_ifattach.h> 113 #include <netinet6/nd6.h> 114 #include <netinet6/in6_prefix.h> 115 116 #ifdef IPSEC 117 #include <netinet6/ipsec.h> 118 #ifdef INET6 119 #include <netinet6/ipsec6.h> 120 #endif 121 #endif 122 123 #ifdef FAST_IPSEC 124 #include <netproto/ipsec/ipsec.h> 125 #include <netproto/ipsec/ipsec6.h> 126 #define IPSEC 127 #endif /* FAST_IPSEC */ 128 129 #include <net/ip6fw/ip6_fw.h> 130 131 #include <netinet6/ip6protosw.h> 132 133 #include <net/net_osdep.h> 134 135 extern struct domain inet6domain; 136 extern struct protosw inet6sw[]; 137 138 u_char ip6_protox[IPPROTO_MAX]; 139 struct in6_ifaddr *in6_ifaddr; 140 141 extern struct callout in6_tmpaddrtimer_ch; 142 143 int ip6_forward_srcrt; /* XXX */ 144 int ip6_sourcecheck; /* XXX */ 145 int ip6_sourcecheck_interval; /* XXX */ 146 147 int ip6_ours_check_algorithm; 148 149 struct pfil_head inet6_pfil_hook; 150 151 /* firewall hooks */ 152 ip6_fw_chk_t *ip6_fw_chk_ptr; 153 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 154 int ip6_fw_enable = 1; 155 156 struct ip6stat ip6stat; 157 158 static void ip6_init2 (void *); 159 static struct ip6aux *ip6_setdstifaddr (struct mbuf *, struct in6_ifaddr *); 160 static int ip6_hopopts_input (u_int32_t *, u_int32_t *, struct mbuf **, int *); 161 static void ip6_input(netmsg_t msg); 162 #ifdef PULLDOWN_TEST 163 static struct mbuf *ip6_pullexthdr (struct mbuf *, size_t, int); 164 #endif 165 static void transport6_processing_handler(netmsg_t netmsg); 166 167 /* 168 * IP6 initialization: fill in IP6 protocol switch table. 169 * All protocols not implemented in kernel go to raw IP6 protocol handler. 170 */ 171 void 172 ip6_init(void) 173 { 174 struct protosw *pr; 175 int i; 176 struct timeval tv; 177 178 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 179 if (pr == NULL) 180 panic("ip6_init"); 181 for (i = 0; i < IPPROTO_MAX; i++) 182 ip6_protox[i] = pr - inet6sw; 183 for (pr = inet6domain.dom_protosw; 184 pr < inet6domain.dom_protoswNPROTOSW; pr++) 185 if (pr->pr_domain->dom_family == PF_INET6 && 186 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 187 ip6_protox[pr->pr_protocol] = pr - inet6sw; 188 189 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 190 inet6_pfil_hook.ph_af = AF_INET6; 191 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) { 192 kprintf("%s: WARNING: unable to register pfil hook, " 193 "error %d\n", __func__, i); 194 } 195 196 netisr_register(NETISR_IPV6, ip6_input, NULL); /* XXX cpufn */ 197 scope6_init(); 198 addrsel_policy_init(); 199 nd6_init(); 200 frag6_init(); 201 /* 202 * in many cases, random() here does NOT return random number 203 * as initialization during bootstrap time occur in fixed order. 204 */ 205 microtime(&tv); 206 ip6_flow_seq = krandom() ^ tv.tv_usec; 207 microtime(&tv); 208 ip6_desync_factor = (krandom() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 209 } 210 211 static void 212 ip6_init2(void *dummy) 213 { 214 /* nd6_timer_init */ 215 callout_init(&nd6_timer_ch); 216 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 217 218 /* router renumbering prefix list maintenance */ 219 callout_init(&in6_rr_timer_ch); 220 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 221 222 /* timer for regeneranation of temporary addresses randomize ID */ 223 callout_init(&in6_tmpaddrtimer_ch); 224 callout_reset(&in6_tmpaddrtimer_ch, 225 (ip6_temp_preferred_lifetime - ip6_desync_factor - 226 ip6_temp_regen_advance) * hz, 227 in6_tmpaddrtimer, NULL); 228 } 229 230 /* cheat */ 231 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 232 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 233 234 extern struct route_in6 ip6_forward_rt; 235 236 static 237 void 238 ip6_input(netmsg_t msg) 239 { 240 struct mbuf *m = msg->packet.nm_packet; 241 struct ip6_hdr *ip6; 242 int off = sizeof(struct ip6_hdr), nest; 243 u_int32_t plen; 244 u_int32_t rtalert = ~0; 245 int nxt, ours = 0, rh_present = 0; 246 struct ifnet *deliverifp = NULL; 247 struct in6_addr odst; 248 int srcrt = 0; 249 250 #ifdef IPSEC 251 /* 252 * should the inner packet be considered authentic? 253 * see comment in ah4_input(). 254 */ 255 if (m) { 256 m->m_flags &= ~M_AUTHIPHDR; 257 m->m_flags &= ~M_AUTHIPDGM; 258 } 259 #endif 260 261 /* 262 * make sure we don't have onion peering information into m_aux. 263 */ 264 ip6_delaux(m); 265 266 /* 267 * mbuf statistics 268 */ 269 if (m->m_flags & M_EXT) { 270 if (m->m_next) 271 ip6stat.ip6s_mext2m++; 272 else 273 ip6stat.ip6s_mext1++; 274 } else { 275 #define M2MMAX NELEM(ip6stat.ip6s_m2m) 276 if (m->m_next) { 277 if (m->m_flags & M_LOOP) { 278 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 279 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 280 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 281 else 282 ip6stat.ip6s_m2m[0]++; 283 } else 284 ip6stat.ip6s_m1++; 285 #undef M2MMAX 286 } 287 288 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 289 ip6stat.ip6s_total++; 290 291 #ifndef PULLDOWN_TEST 292 /* 293 * L2 bridge code and some other code can return mbuf chain 294 * that does not conform to KAME requirement. too bad. 295 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 296 */ 297 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 298 struct mbuf *n; 299 300 n = m_getb(m->m_pkthdr.len, MB_DONTWAIT, MT_HEADER, M_PKTHDR); 301 if (n == NULL) 302 goto bad; 303 M_MOVE_PKTHDR(n, m); 304 305 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 306 n->m_len = n->m_pkthdr.len; 307 m_freem(m); 308 m = n; 309 } 310 IP6_EXTHDR_CHECK_VOIDRET(m, 0, sizeof(struct ip6_hdr)); 311 #endif 312 313 if (m->m_len < sizeof(struct ip6_hdr)) { 314 struct ifnet *inifp; 315 inifp = m->m_pkthdr.rcvif; 316 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 317 ip6stat.ip6s_toosmall++; 318 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 319 goto bad2; 320 } 321 } 322 323 ip6 = mtod(m, struct ip6_hdr *); 324 325 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 326 ip6stat.ip6s_badvers++; 327 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 328 goto bad; 329 } 330 331 /* 332 * Run through list of hooks for input packets. 333 * 334 * NB: Beware of the destination address changing 335 * (e.g. by NAT rewriting). When this happens, 336 * tell ip6_forward to do the right thing. 337 */ 338 if (pfil_has_hooks(&inet6_pfil_hook)) { 339 odst = ip6->ip6_dst; 340 if (pfil_run_hooks(&inet6_pfil_hook, &m, 341 m->m_pkthdr.rcvif, PFIL_IN)) { 342 goto bad2; 343 } 344 if (m == NULL) /* consumed by filter */ 345 goto bad2; 346 ip6 = mtod(m, struct ip6_hdr *); 347 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 348 } 349 350 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 351 352 #ifdef ALTQ 353 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 354 /* packet is dropped by traffic conditioner */ 355 return; 356 } 357 #endif 358 359 /* 360 * Check with the firewall... 361 */ 362 if (ip6_fw_enable && ip6_fw_chk_ptr) { 363 u_short port = 0; 364 /* If ipfw says divert, we have to just drop packet */ 365 /* use port as a dummy argument */ 366 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 367 m_freem(m); 368 m = NULL; 369 } 370 if (!m) 371 goto bad2; 372 } 373 374 /* 375 * Check against address spoofing/corruption. 376 */ 377 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 378 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 379 /* 380 * XXX: "badscope" is not very suitable for a multicast source. 381 */ 382 ip6stat.ip6s_badscope++; 383 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 384 goto bad; 385 } 386 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 387 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 388 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 389 ip6stat.ip6s_badscope++; 390 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 391 goto bad; 392 } 393 394 /* 395 * The following check is not documented in specs. A malicious 396 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 397 * and bypass security checks (act as if it was from 127.0.0.1 by using 398 * IPv6 src ::ffff:127.0.0.1). Be cautious. 399 * 400 * This check chokes if we are in an SIIT cloud. As none of BSDs 401 * support IPv4-less kernel compilation, we cannot support SIIT 402 * environment at all. So, it makes more sense for us to reject any 403 * malicious packets for non-SIIT environment, than try to do a 404 * partical support for SIIT environment. 405 */ 406 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 407 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 408 ip6stat.ip6s_badscope++; 409 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 410 goto bad; 411 } 412 #if 0 413 /* 414 * Reject packets with IPv4 compatible addresses (auto tunnel). 415 * 416 * The code forbids auto tunnel relay case in RFC1933 (the check is 417 * stronger than RFC1933). We may want to re-enable it if mech-xx 418 * is revised to forbid relaying case. 419 */ 420 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 421 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 422 ip6stat.ip6s_badscope++; 423 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 424 goto bad; 425 } 426 #endif 427 428 /* drop packets if interface ID portion is already filled */ 429 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 430 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 431 ip6->ip6_src.s6_addr16[1]) { 432 ip6stat.ip6s_badscope++; 433 goto bad; 434 } 435 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 436 ip6->ip6_dst.s6_addr16[1]) { 437 ip6stat.ip6s_badscope++; 438 goto bad; 439 } 440 } 441 442 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 443 ip6->ip6_src.s6_addr16[1] 444 = htons(m->m_pkthdr.rcvif->if_index); 445 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 446 ip6->ip6_dst.s6_addr16[1] 447 = htons(m->m_pkthdr.rcvif->if_index); 448 449 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 450 /* 451 * We use rt->rt_ifp to determine if the address is ours or not. 452 * If rt_ifp is lo0, the address is ours. 453 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 454 * so any address under fe80::%lo0/64 will be mistakenly considered 455 * local. The special case is supplied to handle the case properly 456 * by actually looking at interface addresses 457 * (using in6ifa_ifpwithaddr). 458 */ 459 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) && 460 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 461 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 462 icmp6_error(m, ICMP6_DST_UNREACH, 463 ICMP6_DST_UNREACH_ADDR, 0); 464 /* m is already freed */ 465 goto bad2; 466 } 467 468 ours = 1; 469 deliverifp = m->m_pkthdr.rcvif; 470 goto hbhcheck; 471 } 472 #endif 473 474 /* 475 * Multicast check 476 */ 477 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 478 struct in6_multi *in6m = NULL; 479 480 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 481 /* 482 * See if we belong to the destination multicast group on the 483 * arrival interface. 484 */ 485 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 486 if (in6m) 487 ours = 1; 488 else if (!ip6_mrouter) { 489 ip6stat.ip6s_notmember++; 490 ip6stat.ip6s_cantforward++; 491 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 492 goto bad; 493 } 494 deliverifp = m->m_pkthdr.rcvif; 495 goto hbhcheck; 496 } 497 498 /* 499 * Unicast check 500 */ 501 switch (ip6_ours_check_algorithm) { 502 default: 503 /* 504 * XXX: I intentionally broke our indentation rule here, 505 * since this switch-case is just for measurement and 506 * therefore should soon be removed. 507 */ 508 if (ip6_forward_rt.ro_rt != NULL && 509 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) && 510 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 511 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 512 ip6stat.ip6s_forward_cachehit++; 513 else { 514 struct sockaddr_in6 *dst6; 515 516 if (ip6_forward_rt.ro_rt) { 517 /* route is down or destination is different */ 518 ip6stat.ip6s_forward_cachemiss++; 519 RTFREE(ip6_forward_rt.ro_rt); 520 ip6_forward_rt.ro_rt = 0; 521 } 522 523 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 524 dst6 = &ip6_forward_rt.ro_dst; 525 dst6->sin6_len = sizeof(struct sockaddr_in6); 526 dst6->sin6_family = AF_INET6; 527 dst6->sin6_addr = ip6->ip6_dst; 528 529 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 530 } 531 532 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 533 534 /* 535 * Accept the packet if the forwarding interface to the destination 536 * according to the routing table is the loopback interface, 537 * unless the associated route has a gateway. 538 * Note that this approach causes to accept a packet if there is a 539 * route to the loopback interface for the destination of the packet. 540 * But we think it's even useful in some situations, e.g. when using 541 * a special daemon which wants to intercept the packet. 542 * 543 * XXX: some OSes automatically make a cloned route for the destination 544 * of an outgoing packet. If the outgoing interface of the packet 545 * is a loopback one, the kernel would consider the packet to be 546 * accepted, even if we have no such address assinged on the interface. 547 * We check the cloned flag of the route entry to reject such cases, 548 * assuming that route entries for our own addresses are not made by 549 * cloning (it should be true because in6_addloop explicitly installs 550 * the host route). However, we might have to do an explicit check 551 * while it would be less efficient. Or, should we rather install a 552 * reject route for such a case? 553 */ 554 if (ip6_forward_rt.ro_rt && 555 (ip6_forward_rt.ro_rt->rt_flags & 556 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 557 #ifdef RTF_WASCLONED 558 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 559 #endif 560 #ifdef RTF_CLONED 561 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 562 #endif 563 #if 0 564 /* 565 * The check below is redundant since the comparison of 566 * the destination and the key of the rtentry has 567 * already done through looking up the routing table. 568 */ 569 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 570 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 571 #endif 572 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 573 struct in6_ifaddr *ia6 = 574 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 575 576 /* 577 * record address information into m_aux. 578 */ 579 ip6_setdstifaddr(m, ia6); 580 581 /* 582 * packets to a tentative, duplicated, or somehow invalid 583 * address must not be accepted. 584 */ 585 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 586 /* this address is ready */ 587 ours = 1; 588 deliverifp = ia6->ia_ifp; /* correct? */ 589 /* Count the packet in the ip address stats */ 590 IFA_STAT_INC(&ia6->ia_ifa, ipackets, 1); 591 IFA_STAT_INC(&ia6->ia_ifa, ibytes, m->m_pkthdr.len); 592 goto hbhcheck; 593 } else { 594 /* address is not ready, so discard the packet. */ 595 nd6log((LOG_INFO, 596 "ip6_input: packet to an unready address %s->%s\n", 597 ip6_sprintf(&ip6->ip6_src), 598 ip6_sprintf(&ip6->ip6_dst))); 599 600 goto bad; 601 } 602 } 603 } /* XXX indentation (see above) */ 604 605 /* 606 * FAITH(Firewall Aided Internet Translator) 607 */ 608 if (ip6_keepfaith) { 609 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 610 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 611 /* XXX do we need more sanity checks? */ 612 ours = 1; 613 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 614 goto hbhcheck; 615 } 616 } 617 618 /* 619 * Now there is no reason to process the packet if it's not our own 620 * and we're not a router. 621 */ 622 if (!ip6_forwarding) { 623 ip6stat.ip6s_cantforward++; 624 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 625 goto bad; 626 } 627 628 hbhcheck: 629 /* 630 * record address information into m_aux, if we don't have one yet. 631 * note that we are unable to record it, if the address is not listed 632 * as our interface address (e.g. multicast addresses, addresses 633 * within FAITH prefixes and such). 634 */ 635 if (deliverifp && !ip6_getdstifaddr(m)) { 636 struct in6_ifaddr *ia6; 637 638 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 639 if (ia6) { 640 if (!ip6_setdstifaddr(m, ia6)) { 641 /* 642 * XXX maybe we should drop the packet here, 643 * as we could not provide enough information 644 * to the upper layers. 645 */ 646 } 647 } 648 } 649 650 /* 651 * Process Hop-by-Hop options header if it's contained. 652 * m may be modified in ip6_hopopts_input(). 653 * If a JumboPayload option is included, plen will also be modified. 654 */ 655 plen = (u_int32_t)ntohs(ip6->ip6_plen); 656 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 657 struct ip6_hbh *hbh; 658 659 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 660 #if 0 /*touches NULL pointer*/ 661 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 662 #endif 663 goto bad2; /* m have already been freed */ 664 } 665 666 /* adjust pointer */ 667 ip6 = mtod(m, struct ip6_hdr *); 668 669 /* 670 * if the payload length field is 0 and the next header field 671 * indicates Hop-by-Hop Options header, then a Jumbo Payload 672 * option MUST be included. 673 */ 674 if (ip6->ip6_plen == 0 && plen == 0) { 675 /* 676 * Note that if a valid jumbo payload option is 677 * contained, ip6_hoptops_input() must set a valid 678 * (non-zero) payload length to the variable plen. 679 */ 680 ip6stat.ip6s_badoptions++; 681 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 682 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 683 icmp6_error(m, ICMP6_PARAM_PROB, 684 ICMP6_PARAMPROB_HEADER, 685 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 686 goto bad2; 687 } 688 #ifndef PULLDOWN_TEST 689 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 690 hbh = (struct ip6_hbh *)(ip6 + 1); 691 #else 692 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 693 sizeof(struct ip6_hbh)); 694 if (hbh == NULL) { 695 ip6stat.ip6s_tooshort++; 696 goto bad2; 697 } 698 #endif 699 nxt = hbh->ip6h_nxt; 700 701 /* 702 * If we are acting as a router and the packet contains a 703 * router alert option, see if we know the option value. 704 * Currently, we only support the option value for MLD, in which 705 * case we should pass the packet to the multicast routing 706 * daemon. 707 */ 708 if (rtalert != ~0 && ip6_forwarding) { 709 switch (rtalert) { 710 case IP6OPT_RTALERT_MLD: 711 ours = 1; 712 break; 713 default: 714 /* 715 * RFC2711 requires unrecognized values must be 716 * silently ignored. 717 */ 718 break; 719 } 720 } 721 } else 722 nxt = ip6->ip6_nxt; 723 724 /* 725 * Check that the amount of data in the buffers 726 * is as at least much as the IPv6 header would have us expect. 727 * Trim mbufs if longer than we expect. 728 * Drop packet if shorter than we expect. 729 */ 730 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 731 ip6stat.ip6s_tooshort++; 732 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 733 goto bad; 734 } 735 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 736 if (m->m_len == m->m_pkthdr.len) { 737 m->m_len = sizeof(struct ip6_hdr) + plen; 738 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 739 } else 740 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 741 } 742 743 /* 744 * Forward if desirable. 745 */ 746 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 747 /* 748 * If we are acting as a multicast router, all 749 * incoming multicast packets are passed to the 750 * kernel-level multicast forwarding function. 751 * The packet is returned (relatively) intact; if 752 * ip6_mforward() returns a non-zero value, the packet 753 * must be discarded, else it may be accepted below. 754 */ 755 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 756 ip6stat.ip6s_cantforward++; 757 goto bad; 758 } 759 if (!ours) 760 goto bad; 761 } else if (!ours) { 762 ip6_forward(m, srcrt); 763 goto bad2; 764 } 765 766 ip6 = mtod(m, struct ip6_hdr *); 767 768 /* 769 * Malicious party may be able to use IPv4 mapped addr to confuse 770 * tcp/udp stack and bypass security checks (act as if it was from 771 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 772 * 773 * For SIIT end node behavior, you may want to disable the check. 774 * However, you will become vulnerable to attacks using IPv4 mapped 775 * source. 776 */ 777 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 778 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 779 ip6stat.ip6s_badscope++; 780 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 781 goto bad; 782 } 783 784 /* 785 * Tell launch routine the next header 786 */ 787 ip6stat.ip6s_delivered++; 788 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 789 nest = 0; 790 791 rh_present = 0; 792 while (nxt != IPPROTO_DONE) { 793 struct protosw *sw6; 794 795 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 796 ip6stat.ip6s_toomanyhdr++; 797 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 798 goto bad; 799 } 800 801 /* 802 * protection against faulty packet - there should be 803 * more sanity checks in header chain processing. 804 */ 805 if (m->m_pkthdr.len < off) { 806 ip6stat.ip6s_tooshort++; 807 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 808 goto bad; 809 } 810 811 #if 0 812 /* 813 * do we need to do it for every header? yeah, other 814 * functions can play with it (like re-allocate and copy). 815 */ 816 mhist = ip6_addaux(m); 817 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 818 hist = mtod(mhist, caddr_t) + mhist->m_len; 819 bcopy(&nxt, hist, sizeof(nxt)); 820 mhist->m_len += sizeof(nxt); 821 } else { 822 ip6stat.ip6s_toomanyhdr++; 823 goto bad; 824 } 825 #endif 826 827 if (nxt == IPPROTO_ROUTING) { 828 if (rh_present++) { 829 in6_ifstat_inc(m->m_pkthdr.rcvif, 830 ifs6_in_hdrerr); 831 ip6stat.ip6s_badoptions++; 832 goto bad; 833 } 834 } 835 836 sw6 = &inet6sw[ip6_protox[nxt]]; 837 #ifdef IPSEC 838 /* 839 * enforce IPsec policy checking if we are seeing last header. 840 * note that we do not visit this with protocols with pcb layer 841 * code - like udp/tcp/raw ip. 842 */ 843 if ((sw6->pr_flags & PR_LASTHDR) && ipsec6_in_reject(m, NULL)) { 844 ipsec6stat.in_polvio++; 845 goto bad; 846 } 847 #endif 848 /* 849 * If this is a terminal header forward to the port, otherwise 850 * process synchronously for more headers. 851 */ 852 if (sw6->pr_flags & PR_LASTHDR) { 853 struct netmsg_packet *pmsg; 854 lwkt_port_t port; 855 856 port = netisr_cpuport(0); /* XXX */ 857 KKASSERT(port != NULL); 858 pmsg = &m->m_hdr.mh_netmsg; 859 netmsg_init(&pmsg->base, NULL, 860 &netisr_apanic_rport, 861 0, transport6_processing_handler); 862 pmsg->nm_packet = m; 863 pmsg->nm_nxt = nxt; 864 pmsg->base.lmsg.u.ms_result = off; 865 lwkt_sendmsg(port, &pmsg->base.lmsg); 866 /* done with m */ 867 nxt = IPPROTO_DONE; 868 } else { 869 nxt = sw6->pr_input(&m, &off, nxt); 870 } 871 } 872 goto bad2; 873 bad: 874 m_freem(m); 875 bad2: 876 ; 877 /* msg was embedded in the mbuf, do not reply! */ 878 } 879 880 /* 881 * We have to call the pr_input() function from the correct protocol 882 * thread. The sw6->pr_soport() request at the end of ip6_input() 883 * returns the port and we forward a netmsg to the port to execute 884 * this function. 885 */ 886 static void 887 transport6_processing_handler(netmsg_t netmsg) 888 { 889 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg; 890 struct protosw *sw6; 891 int hlen; 892 int nxt; 893 894 sw6 = &inet6sw[ip6_protox[pmsg->nm_nxt]]; 895 hlen = pmsg->base.lmsg.u.ms_result; 896 897 nxt = sw6->pr_input(&pmsg->nm_packet, &hlen, pmsg->nm_nxt); 898 KKASSERT(nxt == IPPROTO_DONE); 899 /* netmsg was embedded in the mbuf, do not reply! */ 900 } 901 902 /* 903 * set/grab in6_ifaddr correspond to IPv6 destination address. 904 * XXX backward compatibility wrapper 905 */ 906 static struct ip6aux * 907 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 908 { 909 struct ip6aux *n; 910 911 n = ip6_addaux(m); 912 if (n) 913 n->ip6a_dstia6 = ia6; 914 return n; /* NULL if failed to set */ 915 } 916 917 struct in6_ifaddr * 918 ip6_getdstifaddr(struct mbuf *m) 919 { 920 struct ip6aux *n; 921 922 n = ip6_findaux(m); 923 if (n) 924 return n->ip6a_dstia6; 925 else 926 return NULL; 927 } 928 929 /* 930 * Hop-by-Hop options header processing. If a valid jumbo payload option is 931 * included, the real payload length will be stored in plenp. 932 */ 933 static int 934 ip6_hopopts_input(u_int32_t *plenp, 935 u_int32_t *rtalertp,/* XXX: should be stored more smart way */ 936 struct mbuf **mp, 937 int *offp) 938 { 939 struct mbuf *m = *mp; 940 int off = *offp, hbhlen; 941 struct ip6_hbh *hbh; 942 943 /* validation of the length of the header */ 944 #ifndef PULLDOWN_TEST 945 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 946 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 947 hbhlen = (hbh->ip6h_len + 1) << 3; 948 949 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 950 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 951 #else 952 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 953 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 954 if (hbh == NULL) { 955 ip6stat.ip6s_tooshort++; 956 return -1; 957 } 958 hbhlen = (hbh->ip6h_len + 1) << 3; 959 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 960 hbhlen); 961 if (hbh == NULL) { 962 ip6stat.ip6s_tooshort++; 963 return -1; 964 } 965 #endif 966 off += hbhlen; 967 hbhlen -= sizeof(struct ip6_hbh); 968 969 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 970 hbhlen, rtalertp, plenp) < 0) 971 return (-1); 972 973 *offp = off; 974 *mp = m; 975 return (0); 976 } 977 978 /* 979 * Search header for all Hop-by-hop options and process each option. 980 * This function is separate from ip6_hopopts_input() in order to 981 * handle a case where the sending node itself process its hop-by-hop 982 * options header. In such a case, the function is called from ip6_output(). 983 * 984 * The function assumes that hbh header is located right after the IPv6 header 985 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 986 * opthead + hbhlen is located in continuous memory region. 987 */ 988 int 989 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 990 u_int32_t *rtalertp, u_int32_t *plenp) 991 { 992 struct ip6_hdr *ip6; 993 int optlen = 0; 994 u_int8_t *opt = opthead; 995 u_int16_t rtalert_val; 996 u_int32_t jumboplen; 997 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 998 999 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 1000 switch (*opt) { 1001 case IP6OPT_PAD1: 1002 optlen = 1; 1003 break; 1004 case IP6OPT_PADN: 1005 if (hbhlen < IP6OPT_MINLEN) { 1006 ip6stat.ip6s_toosmall++; 1007 goto bad; 1008 } 1009 optlen = *(opt + 1) + 2; 1010 break; 1011 case IP6OPT_RTALERT: 1012 /* XXX may need check for alignment */ 1013 if (hbhlen < IP6OPT_RTALERT_LEN) { 1014 ip6stat.ip6s_toosmall++; 1015 goto bad; 1016 } 1017 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 1018 /* XXX stat */ 1019 icmp6_error(m, ICMP6_PARAM_PROB, 1020 ICMP6_PARAMPROB_HEADER, 1021 erroff + opt + 1 - opthead); 1022 return (-1); 1023 } 1024 optlen = IP6OPT_RTALERT_LEN; 1025 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1026 *rtalertp = ntohs(rtalert_val); 1027 break; 1028 case IP6OPT_JUMBO: 1029 /* XXX may need check for alignment */ 1030 if (hbhlen < IP6OPT_JUMBO_LEN) { 1031 ip6stat.ip6s_toosmall++; 1032 goto bad; 1033 } 1034 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1035 /* XXX stat */ 1036 icmp6_error(m, ICMP6_PARAM_PROB, 1037 ICMP6_PARAMPROB_HEADER, 1038 erroff + opt + 1 - opthead); 1039 return (-1); 1040 } 1041 optlen = IP6OPT_JUMBO_LEN; 1042 1043 /* 1044 * IPv6 packets that have non 0 payload length 1045 * must not contain a jumbo payload option. 1046 */ 1047 ip6 = mtod(m, struct ip6_hdr *); 1048 if (ip6->ip6_plen) { 1049 ip6stat.ip6s_badoptions++; 1050 icmp6_error(m, ICMP6_PARAM_PROB, 1051 ICMP6_PARAMPROB_HEADER, 1052 erroff + opt - opthead); 1053 return (-1); 1054 } 1055 1056 /* 1057 * We may see jumbolen in unaligned location, so 1058 * we'd need to perform bcopy(). 1059 */ 1060 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1061 jumboplen = (u_int32_t)htonl(jumboplen); 1062 1063 #if 1 1064 /* 1065 * if there are multiple jumbo payload options, 1066 * *plenp will be non-zero and the packet will be 1067 * rejected. 1068 * the behavior may need some debate in ipngwg - 1069 * multiple options does not make sense, however, 1070 * there's no explicit mention in specification. 1071 */ 1072 if (*plenp != 0) { 1073 ip6stat.ip6s_badoptions++; 1074 icmp6_error(m, ICMP6_PARAM_PROB, 1075 ICMP6_PARAMPROB_HEADER, 1076 erroff + opt + 2 - opthead); 1077 return (-1); 1078 } 1079 #endif 1080 1081 /* 1082 * jumbo payload length must be larger than 65535. 1083 */ 1084 if (jumboplen <= IPV6_MAXPACKET) { 1085 ip6stat.ip6s_badoptions++; 1086 icmp6_error(m, ICMP6_PARAM_PROB, 1087 ICMP6_PARAMPROB_HEADER, 1088 erroff + opt + 2 - opthead); 1089 return (-1); 1090 } 1091 *plenp = jumboplen; 1092 1093 break; 1094 default: /* unknown option */ 1095 if (hbhlen < IP6OPT_MINLEN) { 1096 ip6stat.ip6s_toosmall++; 1097 goto bad; 1098 } 1099 optlen = ip6_unknown_opt(opt, m, 1100 erroff + opt - opthead); 1101 if (optlen == -1) 1102 return (-1); 1103 optlen += 2; 1104 break; 1105 } 1106 } 1107 1108 return (0); 1109 1110 bad: 1111 m_freem(m); 1112 return (-1); 1113 } 1114 1115 /* 1116 * Unknown option processing. 1117 * The third argument `off' is the offset from the IPv6 header to the option, 1118 * which is necessary if the IPv6 header the and option header and IPv6 header 1119 * is not continuous in order to return an ICMPv6 error. 1120 */ 1121 int 1122 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1123 { 1124 struct ip6_hdr *ip6; 1125 1126 switch (IP6OPT_TYPE(*optp)) { 1127 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1128 return ((int)*(optp + 1)); 1129 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1130 m_freem(m); 1131 return (-1); 1132 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1133 ip6stat.ip6s_badoptions++; 1134 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1135 return (-1); 1136 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1137 ip6stat.ip6s_badoptions++; 1138 ip6 = mtod(m, struct ip6_hdr *); 1139 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1140 (m->m_flags & (M_BCAST|M_MCAST))) 1141 m_freem(m); 1142 else 1143 icmp6_error(m, ICMP6_PARAM_PROB, 1144 ICMP6_PARAMPROB_OPTION, off); 1145 return (-1); 1146 } 1147 1148 m_freem(m); /* XXX: NOTREACHED */ 1149 return (-1); 1150 } 1151 1152 /* 1153 * Create the "control" list for this pcb. 1154 * The function will not modify mbuf chain at all. 1155 * 1156 * with KAME mbuf chain restriction: 1157 * The routine will be called from upper layer handlers like tcp6_input(). 1158 * Thus the routine assumes that the caller (tcp6_input) have already 1159 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1160 * very first mbuf on the mbuf chain. 1161 */ 1162 void 1163 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6, 1164 struct mbuf *m) 1165 { 1166 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1167 struct thread *td = curthread; /* XXX */ 1168 int privileged = 0; 1169 1170 1171 if (priv_check(td, PRIV_ROOT) == 0) 1172 privileged++; 1173 1174 #ifdef SO_TIMESTAMP 1175 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1176 struct timeval tv; 1177 1178 microtime(&tv); 1179 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1180 SCM_TIMESTAMP, SOL_SOCKET); 1181 if (*mp) { 1182 mp = &(*mp)->m_next; 1183 } 1184 } 1185 #endif 1186 1187 /* RFC 2292 sec. 5 */ 1188 if (in6p->in6p_flags & IN6P_PKTINFO) { 1189 struct in6_pktinfo pi6; 1190 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1191 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1192 pi6.ipi6_addr.s6_addr16[1] = 0; 1193 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1194 ? m->m_pkthdr.rcvif->if_index 1195 : 0; 1196 *mp = sbcreatecontrol((caddr_t) &pi6, 1197 sizeof(struct in6_pktinfo), IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), 1198 IPPROTO_IPV6); 1199 if (*mp) 1200 mp = &(*mp)->m_next; 1201 } 1202 1203 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1204 int hlim = ip6->ip6_hlim & 0xff; 1205 *mp = sbcreatecontrol((caddr_t) &hlim, 1206 sizeof(int), IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1207 if (*mp) 1208 mp = &(*mp)->m_next; 1209 } 1210 1211 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1212 u_int32_t flowinfo; 1213 int tclass; 1214 1215 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1216 flowinfo >>= 20; 1217 1218 tclass = flowinfo & 0xff; 1219 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1220 IPV6_TCLASS, IPPROTO_IPV6); 1221 if (*mp) 1222 mp = &(*mp)->m_next; 1223 } 1224 1225 /* 1226 * IPV6_HOPOPTS socket option. We require super-user privilege 1227 * for the option, but it might be too strict, since there might 1228 * be some hop-by-hop options which can be returned to normal user. 1229 * See RFC 2292 section 6. 1230 */ 1231 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1232 /* 1233 * Check if a hop-by-hop options header is contatined in the 1234 * received packet, and if so, store the options as ancillary 1235 * data. Note that a hop-by-hop options header must be 1236 * just after the IPv6 header, which fact is assured through 1237 * the IPv6 input processing. 1238 */ 1239 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1240 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1241 struct ip6_hbh *hbh; 1242 int hbhlen = 0; 1243 #ifdef PULLDOWN_TEST 1244 struct mbuf *ext; 1245 #endif 1246 1247 #ifndef PULLDOWN_TEST 1248 hbh = (struct ip6_hbh *)(ip6 + 1); 1249 hbhlen = (hbh->ip6h_len + 1) << 3; 1250 #else 1251 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1252 ip6->ip6_nxt); 1253 if (ext == NULL) { 1254 ip6stat.ip6s_tooshort++; 1255 return; 1256 } 1257 hbh = mtod(ext, struct ip6_hbh *); 1258 hbhlen = (hbh->ip6h_len + 1) << 3; 1259 if (hbhlen != ext->m_len) { 1260 m_freem(ext); 1261 ip6stat.ip6s_tooshort++; 1262 return; 1263 } 1264 #endif 1265 1266 /* 1267 * XXX: We copy whole the header even if a jumbo 1268 * payload option is included, which option is to 1269 * be removed before returning in the RFC 2292. 1270 * Note: this constraint is removed in 2292bis. 1271 */ 1272 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1273 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), IPPROTO_IPV6); 1274 if (*mp) 1275 mp = &(*mp)->m_next; 1276 #ifdef PULLDOWN_TEST 1277 m_freem(ext); 1278 #endif 1279 } 1280 } 1281 1282 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1283 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1284 int proto, off, nxt; 1285 1286 /* 1287 * go through the header chain to see if a routing header is 1288 * contained in the packet. We need this information to store 1289 * destination options headers (if any) properly. 1290 * XXX: performance issue. We should record this info when 1291 * processing extension headers in incoming routine. 1292 * (todo) use m_aux? 1293 */ 1294 proto = IPPROTO_IPV6; 1295 off = 0; 1296 nxt = -1; 1297 while (1) { 1298 int newoff; 1299 1300 newoff = ip6_nexthdr(m, off, proto, &nxt); 1301 if (newoff < 0) 1302 break; 1303 if (newoff < off) /* invalid, check for safety */ 1304 break; 1305 if ((proto = nxt) == IPPROTO_ROUTING) 1306 break; 1307 off = newoff; 1308 } 1309 } 1310 1311 if ((in6p->in6p_flags & 1312 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1313 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1314 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1315 1316 /* 1317 * Search for destination options headers or routing 1318 * header(s) through the header chain, and stores each 1319 * header as ancillary data. 1320 * Note that the order of the headers remains in 1321 * the chain of ancillary data. 1322 */ 1323 while (1) { /* is explicit loop prevention necessary? */ 1324 struct ip6_ext *ip6e = NULL; 1325 int elen; 1326 #ifdef PULLDOWN_TEST 1327 struct mbuf *ext = NULL; 1328 #endif 1329 1330 /* 1331 * if it is not an extension header, don't try to 1332 * pull it from the chain. 1333 */ 1334 switch (nxt) { 1335 case IPPROTO_DSTOPTS: 1336 case IPPROTO_ROUTING: 1337 case IPPROTO_HOPOPTS: 1338 case IPPROTO_AH: /* is it possible? */ 1339 break; 1340 default: 1341 goto loopend; 1342 } 1343 1344 #ifndef PULLDOWN_TEST 1345 if (off + sizeof(*ip6e) > m->m_len) 1346 goto loopend; 1347 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1348 if (nxt == IPPROTO_AH) 1349 elen = (ip6e->ip6e_len + 2) << 2; 1350 else 1351 elen = (ip6e->ip6e_len + 1) << 3; 1352 if (off + elen > m->m_len) 1353 goto loopend; 1354 #else 1355 ext = ip6_pullexthdr(m, off, nxt); 1356 if (ext == NULL) { 1357 ip6stat.ip6s_tooshort++; 1358 return; 1359 } 1360 ip6e = mtod(ext, struct ip6_ext *); 1361 if (nxt == IPPROTO_AH) 1362 elen = (ip6e->ip6e_len + 2) << 2; 1363 else 1364 elen = (ip6e->ip6e_len + 1) << 3; 1365 if (elen != ext->m_len) { 1366 m_freem(ext); 1367 ip6stat.ip6s_tooshort++; 1368 return; 1369 } 1370 #endif 1371 1372 switch (nxt) { 1373 case IPPROTO_DSTOPTS: 1374 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1375 break; 1376 1377 /* 1378 * We also require super-user privilege for 1379 * the option. 1380 * See the comments on IN6_HOPOPTS. 1381 */ 1382 if (!privileged) 1383 break; 1384 1385 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1386 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1387 IPPROTO_IPV6); 1388 if (*mp) 1389 mp = &(*mp)->m_next; 1390 break; 1391 case IPPROTO_ROUTING: 1392 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1393 break; 1394 1395 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1396 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1397 IPPROTO_IPV6); 1398 if (*mp) 1399 mp = &(*mp)->m_next; 1400 break; 1401 case IPPROTO_HOPOPTS: 1402 case IPPROTO_AH: /* is it possible? */ 1403 break; 1404 1405 default: 1406 /* 1407 * other cases have been filtered in the above. 1408 * none will visit this case. here we supply 1409 * the code just in case (nxt overwritten or 1410 * other cases). 1411 */ 1412 #ifdef PULLDOWN_TEST 1413 m_freem(ext); 1414 #endif 1415 goto loopend; 1416 1417 } 1418 1419 /* proceed with the next header. */ 1420 off += elen; 1421 nxt = ip6e->ip6e_nxt; 1422 ip6e = NULL; 1423 #ifdef PULLDOWN_TEST 1424 m_freem(ext); 1425 ext = NULL; 1426 #endif 1427 } 1428 loopend: 1429 ; 1430 } 1431 #undef IS2292 1432 } 1433 1434 void 1435 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1436 { 1437 struct socket *so; 1438 struct mbuf *m_mtu; 1439 struct ip6_mtuinfo mtuctl; 1440 1441 so = in6p->inp_socket; 1442 1443 if (mtu == NULL) 1444 return; 1445 1446 #ifdef DIAGNOSTIC 1447 if (so == NULL) /* I believe this is impossible */ 1448 panic("ip6_notify_pmtu: socket is NULL"); 1449 #endif 1450 1451 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1452 mtuctl.ip6m_mtu = *mtu; 1453 mtuctl.ip6m_addr = *dst; 1454 1455 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1456 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1457 return; 1458 1459 lwkt_gettoken(&so->so_rcv.ssb_token); 1460 if (sbappendaddr(&so->so_rcv.sb, (struct sockaddr *)dst, NULL, m_mtu) 1461 == 0) { 1462 m_freem(m_mtu); 1463 /* XXX: should count statistics */ 1464 } else { 1465 sorwakeup(so); 1466 } 1467 lwkt_reltoken(&so->so_rcv.ssb_token); 1468 } 1469 1470 #ifdef PULLDOWN_TEST 1471 /* 1472 * pull single extension header from mbuf chain. returns single mbuf that 1473 * contains the result, or NULL on error. 1474 */ 1475 static struct mbuf * 1476 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1477 { 1478 struct ip6_ext ip6e; 1479 size_t elen; 1480 struct mbuf *n; 1481 1482 #ifdef DIAGNOSTIC 1483 switch (nxt) { 1484 case IPPROTO_DSTOPTS: 1485 case IPPROTO_ROUTING: 1486 case IPPROTO_HOPOPTS: 1487 case IPPROTO_AH: /* is it possible? */ 1488 break; 1489 default: 1490 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1491 } 1492 #endif 1493 1494 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1495 if (nxt == IPPROTO_AH) 1496 elen = (ip6e.ip6e_len + 2) << 2; 1497 else 1498 elen = (ip6e.ip6e_len + 1) << 3; 1499 1500 n = m_getb(elen, MB_DONTWAIT, MT_DATA, 0); 1501 if (n == NULL) 1502 return NULL; 1503 n->m_len = 0; 1504 1505 if (elen >= M_TRAILINGSPACE(n)) { 1506 m_free(n); 1507 return NULL; 1508 } 1509 1510 m_copydata(m, off, elen, mtod(n, caddr_t)); 1511 n->m_len = elen; 1512 return n; 1513 } 1514 #endif 1515 1516 /* 1517 * Get pointer to the previous header followed by the header 1518 * currently processed. 1519 * XXX: This function supposes that 1520 * M includes all headers, 1521 * the next header field and the header length field of each header 1522 * are valid, and 1523 * the sum of each header length equals to OFF. 1524 * Because of these assumptions, this function must be called very 1525 * carefully. Moreover, it will not be used in the near future when 1526 * we develop `neater' mechanism to process extension headers. 1527 */ 1528 char * 1529 ip6_get_prevhdr(struct mbuf *m, int off) 1530 { 1531 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1532 1533 if (off == sizeof(struct ip6_hdr)) 1534 return (&ip6->ip6_nxt); 1535 else { 1536 int len, nxt; 1537 struct ip6_ext *ip6e = NULL; 1538 1539 nxt = ip6->ip6_nxt; 1540 len = sizeof(struct ip6_hdr); 1541 while (len < off) { 1542 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1543 1544 switch (nxt) { 1545 case IPPROTO_FRAGMENT: 1546 len += sizeof(struct ip6_frag); 1547 break; 1548 case IPPROTO_AH: 1549 len += (ip6e->ip6e_len + 2) << 2; 1550 break; 1551 default: 1552 len += (ip6e->ip6e_len + 1) << 3; 1553 break; 1554 } 1555 nxt = ip6e->ip6e_nxt; 1556 } 1557 if (ip6e) 1558 return (&ip6e->ip6e_nxt); 1559 else 1560 return NULL; 1561 } 1562 } 1563 1564 /* 1565 * get next header offset. m will be retained. 1566 */ 1567 int 1568 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1569 { 1570 struct ip6_hdr ip6; 1571 struct ip6_ext ip6e; 1572 struct ip6_frag fh; 1573 1574 /* just in case */ 1575 if (m == NULL) 1576 panic("ip6_nexthdr: m == NULL"); 1577 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1578 return -1; 1579 1580 switch (proto) { 1581 case IPPROTO_IPV6: 1582 if (m->m_pkthdr.len < off + sizeof(ip6)) 1583 return -1; 1584 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1585 if (nxtp) 1586 *nxtp = ip6.ip6_nxt; 1587 off += sizeof(ip6); 1588 return off; 1589 1590 case IPPROTO_FRAGMENT: 1591 /* 1592 * terminate parsing if it is not the first fragment, 1593 * it does not make sense to parse through it. 1594 */ 1595 if (m->m_pkthdr.len < off + sizeof(fh)) 1596 return -1; 1597 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1598 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1599 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1600 return -1; 1601 if (nxtp) 1602 *nxtp = fh.ip6f_nxt; 1603 off += sizeof(struct ip6_frag); 1604 return off; 1605 1606 case IPPROTO_AH: 1607 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1608 return -1; 1609 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1610 if (nxtp) 1611 *nxtp = ip6e.ip6e_nxt; 1612 off += (ip6e.ip6e_len + 2) << 2; 1613 return off; 1614 1615 case IPPROTO_HOPOPTS: 1616 case IPPROTO_ROUTING: 1617 case IPPROTO_DSTOPTS: 1618 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1619 return -1; 1620 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1621 if (nxtp) 1622 *nxtp = ip6e.ip6e_nxt; 1623 off += (ip6e.ip6e_len + 1) << 3; 1624 return off; 1625 1626 case IPPROTO_NONE: 1627 case IPPROTO_ESP: 1628 case IPPROTO_IPCOMP: 1629 /* give up */ 1630 return -1; 1631 1632 default: 1633 return -1; 1634 } 1635 1636 return -1; 1637 } 1638 1639 /* 1640 * get offset for the last header in the chain. m will be kept untainted. 1641 */ 1642 int 1643 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1644 { 1645 int newoff; 1646 int nxt; 1647 1648 if (!nxtp) { 1649 nxt = -1; 1650 nxtp = &nxt; 1651 } 1652 while (1) { 1653 newoff = ip6_nexthdr(m, off, proto, nxtp); 1654 if (newoff < 0) 1655 return off; 1656 else if (newoff < off) 1657 return -1; /* invalid */ 1658 else if (newoff == off) 1659 return newoff; 1660 1661 off = newoff; 1662 proto = *nxtp; 1663 } 1664 } 1665 1666 struct ip6aux * 1667 ip6_addaux(struct mbuf *m) 1668 { 1669 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1670 if (!tag) { 1671 tag = m_tag_get(PACKET_TAG_IPV6_INPUT, 1672 sizeof (struct ip6aux), 1673 MB_DONTWAIT); 1674 if (tag) 1675 m_tag_prepend(m, tag); 1676 } 1677 if (tag) 1678 bzero(m_tag_data(tag), sizeof (struct ip6aux)); 1679 return tag ? (struct ip6aux *)m_tag_data(tag) : NULL; 1680 } 1681 1682 struct ip6aux * 1683 ip6_findaux(struct mbuf *m) 1684 { 1685 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1686 return tag ? (struct ip6aux*)(tag+1) : NULL; 1687 } 1688 1689 void 1690 ip6_delaux(struct mbuf *m) 1691 { 1692 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1693 if (tag) 1694 m_tag_delete(m, tag); 1695 } 1696 1697 /* 1698 * System control for IP6 1699 */ 1700 1701 u_char inet6ctlerrmap[PRC_NCMDS] = { 1702 0, 0, 0, 0, 1703 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1704 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1705 EMSGSIZE, EHOSTUNREACH, 0, 0, 1706 0, 0, 0, 0, 1707 ENOPROTOOPT 1708 }; 1709