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 1.4 2003/06/25 03:56:04 dillon 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 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/intrq.h> 94 95 #include <netinet/in.h> 96 #include <netinet/in_systm.h> 97 #ifdef INET 98 #include <netinet/ip.h> 99 #include <netinet/ip_icmp.h> 100 #endif /* INET */ 101 #include <netinet/ip6.h> 102 #include <netinet6/in6_var.h> 103 #include <netinet6/ip6_var.h> 104 #include <netinet/in_pcb.h> 105 #include <netinet/icmp6.h> 106 #include <netinet6/in6_ifattach.h> 107 #include <netinet6/nd6.h> 108 #include <netinet6/in6_prefix.h> 109 110 #ifdef IPSEC 111 #include <netinet6/ipsec.h> 112 #ifdef INET6 113 #include <netinet6/ipsec6.h> 114 #endif 115 #endif 116 117 #ifdef FAST_IPSEC 118 #include <netipsec/ipsec.h> 119 #include <netipsec/ipsec6.h> 120 #define IPSEC 121 #endif /* FAST_IPSEC */ 122 123 #include <netinet6/ip6_fw.h> 124 125 #include <netinet6/ip6protosw.h> 126 127 /* we need it for NLOOP. */ 128 #include "loop.h" 129 130 #include <net/net_osdep.h> 131 132 extern int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **)); 133 134 extern struct domain inet6domain; 135 extern struct ip6protosw inet6sw[]; 136 137 u_char ip6_protox[IPPROTO_MAX]; 138 static int ip6qmaxlen = IFQ_MAXLEN; 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 const int int6intrq_present = 1; 147 148 int ip6_ours_check_algorithm; 149 150 151 /* 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 __P((void *)); 159 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 160 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 161 #ifdef PULLDOWN_TEST 162 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 163 #endif 164 165 166 /* 167 * IP6 initialization: fill in IP6 protocol switch table. 168 * All protocols not implemented in kernel go to raw IP6 protocol handler. 169 */ 170 void 171 ip6_init() 172 { 173 struct ip6protosw *pr; 174 int i; 175 struct timeval tv; 176 177 #ifdef DIAGNOSTIC 178 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 179 panic("sizeof(protosw) != sizeof(ip6protosw)"); 180 #endif 181 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 182 if (pr == 0) 183 panic("ip6_init"); 184 for (i = 0; i < IPPROTO_MAX; i++) 185 ip6_protox[i] = pr - inet6sw; 186 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 187 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 188 if (pr->pr_domain->dom_family == PF_INET6 && 189 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 190 ip6_protox[pr->pr_protocol] = pr - inet6sw; 191 ip6intrq.ifq_maxlen = ip6qmaxlen; 192 register_netisr(NETISR_IPV6, ip6intr); 193 nd6_init(); 194 frag6_init(); 195 /* 196 * in many cases, random() here does NOT return random number 197 * as initialization during bootstrap time occur in fixed order. 198 */ 199 microtime(&tv); 200 ip6_flow_seq = random() ^ tv.tv_usec; 201 microtime(&tv); 202 ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 203 } 204 205 static void 206 ip6_init2(dummy) 207 void *dummy; 208 { 209 210 /* 211 * to route local address of p2p link to loopback, 212 * assign loopback address first. 213 */ 214 in6_ifattach(&loif[0], NULL); 215 216 /* nd6_timer_init */ 217 callout_init(&nd6_timer_ch); 218 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 219 220 /* router renumbering prefix list maintenance */ 221 callout_init(&in6_rr_timer_ch); 222 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 223 224 /* timer for regeneranation of temporary addresses randomize ID */ 225 callout_reset(&in6_tmpaddrtimer_ch, 226 (ip6_temp_preferred_lifetime - ip6_desync_factor - 227 ip6_temp_regen_advance) * hz, 228 in6_tmpaddrtimer, NULL); 229 } 230 231 /* cheat */ 232 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 233 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 234 235 /* 236 * IP6 input interrupt handling. Just pass the packet to ip6_input. 237 */ 238 void 239 ip6intr() 240 { 241 int s; 242 struct mbuf *m; 243 244 for (;;) { 245 s = splimp(); 246 IF_DEQUEUE(&ip6intrq, m); 247 splx(s); 248 if (m == 0) 249 return; 250 ip6_input(m); 251 } 252 } 253 254 extern struct route_in6 ip6_forward_rt; 255 256 void 257 ip6_input(m) 258 struct mbuf *m; 259 { 260 struct ip6_hdr *ip6; 261 int off = sizeof(struct ip6_hdr), nest; 262 u_int32_t plen; 263 u_int32_t rtalert = ~0; 264 int nxt, ours = 0; 265 struct ifnet *deliverifp = NULL; 266 267 #ifdef IPSEC 268 /* 269 * should the inner packet be considered authentic? 270 * see comment in ah4_input(). 271 */ 272 if (m) { 273 m->m_flags &= ~M_AUTHIPHDR; 274 m->m_flags &= ~M_AUTHIPDGM; 275 } 276 #endif 277 278 /* 279 * make sure we don't have onion peering information into m_aux. 280 */ 281 ip6_delaux(m); 282 283 /* 284 * mbuf statistics 285 */ 286 if (m->m_flags & M_EXT) { 287 if (m->m_next) 288 ip6stat.ip6s_mext2m++; 289 else 290 ip6stat.ip6s_mext1++; 291 } else { 292 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 293 if (m->m_next) { 294 if (m->m_flags & M_LOOP) { 295 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 296 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 297 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 298 else 299 ip6stat.ip6s_m2m[0]++; 300 } else 301 ip6stat.ip6s_m1++; 302 #undef M2MMAX 303 } 304 305 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 306 ip6stat.ip6s_total++; 307 308 #ifndef PULLDOWN_TEST 309 /* 310 * L2 bridge code and some other code can return mbuf chain 311 * that does not conform to KAME requirement. too bad. 312 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 313 */ 314 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 315 struct mbuf *n; 316 317 MGETHDR(n, M_DONTWAIT, MT_HEADER); 318 if (n) 319 M_MOVE_PKTHDR(n, m); 320 if (n && n->m_pkthdr.len > MHLEN) { 321 MCLGET(n, M_DONTWAIT); 322 if ((n->m_flags & M_EXT) == 0) { 323 m_freem(n); 324 n = NULL; 325 } 326 } 327 if (n == NULL) { 328 m_freem(m); 329 return; /*ENOBUFS*/ 330 } 331 332 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 333 n->m_len = n->m_pkthdr.len; 334 m_freem(m); 335 m = n; 336 } 337 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 338 #endif 339 340 if (m->m_len < sizeof(struct ip6_hdr)) { 341 struct ifnet *inifp; 342 inifp = m->m_pkthdr.rcvif; 343 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 344 ip6stat.ip6s_toosmall++; 345 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 346 return; 347 } 348 } 349 350 ip6 = mtod(m, struct ip6_hdr *); 351 352 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 353 ip6stat.ip6s_badvers++; 354 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 355 goto bad; 356 } 357 358 /* 359 * Check if we want to allow this packet to be processed. 360 * Consider it to be bad if not. 361 */ 362 if (fr_checkp) { 363 struct mbuf *m1 = m; 364 365 if ((*fr_checkp)((struct ip *)ip6, sizeof(*ip6), 366 m->m_pkthdr.rcvif, 0, &m1) != 0) 367 return; 368 m = m1; 369 if (m == NULL) 370 return; 371 ip6 = mtod(m, struct ip6_hdr *); 372 } 373 374 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 375 376 /* 377 * Check with the firewall... 378 */ 379 if (ip6_fw_enable && ip6_fw_chk_ptr) { 380 u_short port = 0; 381 /* If ipfw says divert, we have to just drop packet */ 382 /* use port as a dummy argument */ 383 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 384 m_freem(m); 385 m = NULL; 386 } 387 if (!m) 388 return; 389 } 390 391 /* 392 * Check against address spoofing/corruption. 393 */ 394 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 395 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 396 /* 397 * XXX: "badscope" is not very suitable for a multicast source. 398 */ 399 ip6stat.ip6s_badscope++; 400 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 401 goto bad; 402 } 403 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 404 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 405 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 406 ip6stat.ip6s_badscope++; 407 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 408 goto bad; 409 } 410 411 /* 412 * The following check is not documented in specs. A malicious 413 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 414 * and bypass security checks (act as if it was from 127.0.0.1 by using 415 * IPv6 src ::ffff:127.0.0.1). Be cautious. 416 * 417 * This check chokes if we are in an SIIT cloud. As none of BSDs 418 * support IPv4-less kernel compilation, we cannot support SIIT 419 * environment at all. So, it makes more sense for us to reject any 420 * malicious packets for non-SIIT environment, than try to do a 421 * partical support for SIIT environment. 422 */ 423 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 424 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 425 ip6stat.ip6s_badscope++; 426 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 427 goto bad; 428 } 429 #if 0 430 /* 431 * Reject packets with IPv4 compatible addresses (auto tunnel). 432 * 433 * The code forbids auto tunnel relay case in RFC1933 (the check is 434 * stronger than RFC1933). We may want to re-enable it if mech-xx 435 * is revised to forbid relaying case. 436 */ 437 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 438 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 439 ip6stat.ip6s_badscope++; 440 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 441 goto bad; 442 } 443 #endif 444 445 /* drop packets if interface ID portion is already filled */ 446 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 447 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 448 ip6->ip6_src.s6_addr16[1]) { 449 ip6stat.ip6s_badscope++; 450 goto bad; 451 } 452 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 453 ip6->ip6_dst.s6_addr16[1]) { 454 ip6stat.ip6s_badscope++; 455 goto bad; 456 } 457 } 458 459 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 460 ip6->ip6_src.s6_addr16[1] 461 = htons(m->m_pkthdr.rcvif->if_index); 462 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 463 ip6->ip6_dst.s6_addr16[1] 464 = htons(m->m_pkthdr.rcvif->if_index); 465 466 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 467 /* 468 * We use rt->rt_ifp to determine if the address is ours or not. 469 * If rt_ifp is lo0, the address is ours. 470 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 471 * so any address under fe80::%lo0/64 will be mistakenly considered 472 * local. The special case is supplied to handle the case properly 473 * by actually looking at interface addresses 474 * (using in6ifa_ifpwithaddr). 475 */ 476 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 477 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 478 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 479 icmp6_error(m, ICMP6_DST_UNREACH, 480 ICMP6_DST_UNREACH_ADDR, 0); 481 /* m is already freed */ 482 return; 483 } 484 485 ours = 1; 486 deliverifp = m->m_pkthdr.rcvif; 487 goto hbhcheck; 488 } 489 #endif 490 491 /* 492 * Multicast check 493 */ 494 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 495 struct in6_multi *in6m = 0; 496 497 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 498 /* 499 * See if we belong to the destination multicast group on the 500 * arrival interface. 501 */ 502 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 503 if (in6m) 504 ours = 1; 505 else if (!ip6_mrouter) { 506 ip6stat.ip6s_notmember++; 507 ip6stat.ip6s_cantforward++; 508 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 509 goto bad; 510 } 511 deliverifp = m->m_pkthdr.rcvif; 512 goto hbhcheck; 513 } 514 515 /* 516 * Unicast check 517 */ 518 switch (ip6_ours_check_algorithm) { 519 default: 520 /* 521 * XXX: I intentionally broke our indentation rule here, 522 * since this switch-case is just for measurement and 523 * therefore should soon be removed. 524 */ 525 if (ip6_forward_rt.ro_rt != NULL && 526 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 527 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 528 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 529 ip6stat.ip6s_forward_cachehit++; 530 else { 531 struct sockaddr_in6 *dst6; 532 533 if (ip6_forward_rt.ro_rt) { 534 /* route is down or destination is different */ 535 ip6stat.ip6s_forward_cachemiss++; 536 RTFREE(ip6_forward_rt.ro_rt); 537 ip6_forward_rt.ro_rt = 0; 538 } 539 540 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 541 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 542 dst6->sin6_len = sizeof(struct sockaddr_in6); 543 dst6->sin6_family = AF_INET6; 544 dst6->sin6_addr = ip6->ip6_dst; 545 #ifdef SCOPEDROUTING 546 ip6_forward_rt.ro_dst.sin6_scope_id = 547 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 548 #endif 549 550 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 551 } 552 553 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 554 555 /* 556 * Accept the packet if the forwarding interface to the destination 557 * according to the routing table is the loopback interface, 558 * unless the associated route has a gateway. 559 * Note that this approach causes to accept a packet if there is a 560 * route to the loopback interface for the destination of the packet. 561 * But we think it's even useful in some situations, e.g. when using 562 * a special daemon which wants to intercept the packet. 563 * 564 * XXX: some OSes automatically make a cloned route for the destination 565 * of an outgoing packet. If the outgoing interface of the packet 566 * is a loopback one, the kernel would consider the packet to be 567 * accepted, even if we have no such address assinged on the interface. 568 * We check the cloned flag of the route entry to reject such cases, 569 * assuming that route entries for our own addresses are not made by 570 * cloning (it should be true because in6_addloop explicitly installs 571 * the host route). However, we might have to do an explicit check 572 * while it would be less efficient. Or, should we rather install a 573 * reject route for such a case? 574 */ 575 if (ip6_forward_rt.ro_rt && 576 (ip6_forward_rt.ro_rt->rt_flags & 577 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 578 #ifdef RTF_WASCLONED 579 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 580 #endif 581 #ifdef RTF_CLONED 582 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 583 #endif 584 #if 0 585 /* 586 * The check below is redundant since the comparison of 587 * the destination and the key of the rtentry has 588 * already done through looking up the routing table. 589 */ 590 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 591 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 592 #endif 593 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 594 struct in6_ifaddr *ia6 = 595 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 596 597 /* 598 * record address information into m_aux. 599 */ 600 (void)ip6_setdstifaddr(m, ia6); 601 602 /* 603 * packets to a tentative, duplicated, or somehow invalid 604 * address must not be accepted. 605 */ 606 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 607 /* this address is ready */ 608 ours = 1; 609 deliverifp = ia6->ia_ifp; /* correct? */ 610 /* Count the packet in the ip address stats */ 611 ia6->ia_ifa.if_ipackets++; 612 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 613 goto hbhcheck; 614 } else { 615 /* address is not ready, so discard the packet. */ 616 nd6log((LOG_INFO, 617 "ip6_input: packet to an unready address %s->%s\n", 618 ip6_sprintf(&ip6->ip6_src), 619 ip6_sprintf(&ip6->ip6_dst))); 620 621 goto bad; 622 } 623 } 624 } /* XXX indentation (see above) */ 625 626 /* 627 * FAITH(Firewall Aided Internet Translator) 628 */ 629 if (ip6_keepfaith) { 630 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 631 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 632 /* XXX do we need more sanity checks? */ 633 ours = 1; 634 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 635 goto hbhcheck; 636 } 637 } 638 639 /* 640 * Now there is no reason to process the packet if it's not our own 641 * and we're not a router. 642 */ 643 if (!ip6_forwarding) { 644 ip6stat.ip6s_cantforward++; 645 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 646 goto bad; 647 } 648 649 hbhcheck: 650 /* 651 * record address information into m_aux, if we don't have one yet. 652 * note that we are unable to record it, if the address is not listed 653 * as our interface address (e.g. multicast addresses, addresses 654 * within FAITH prefixes and such). 655 */ 656 if (deliverifp && !ip6_getdstifaddr(m)) { 657 struct in6_ifaddr *ia6; 658 659 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 660 if (ia6) { 661 if (!ip6_setdstifaddr(m, ia6)) { 662 /* 663 * XXX maybe we should drop the packet here, 664 * as we could not provide enough information 665 * to the upper layers. 666 */ 667 } 668 } 669 } 670 671 /* 672 * Process Hop-by-Hop options header if it's contained. 673 * m may be modified in ip6_hopopts_input(). 674 * If a JumboPayload option is included, plen will also be modified. 675 */ 676 plen = (u_int32_t)ntohs(ip6->ip6_plen); 677 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 678 struct ip6_hbh *hbh; 679 680 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 681 #if 0 /*touches NULL pointer*/ 682 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 683 #endif 684 return; /* m have already been freed */ 685 } 686 687 /* adjust pointer */ 688 ip6 = mtod(m, struct ip6_hdr *); 689 690 /* 691 * if the payload length field is 0 and the next header field 692 * indicates Hop-by-Hop Options header, then a Jumbo Payload 693 * option MUST be included. 694 */ 695 if (ip6->ip6_plen == 0 && plen == 0) { 696 /* 697 * Note that if a valid jumbo payload option is 698 * contained, ip6_hoptops_input() must set a valid 699 * (non-zero) payload length to the variable plen. 700 */ 701 ip6stat.ip6s_badoptions++; 702 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 703 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 704 icmp6_error(m, ICMP6_PARAM_PROB, 705 ICMP6_PARAMPROB_HEADER, 706 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 707 return; 708 } 709 #ifndef PULLDOWN_TEST 710 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 711 hbh = (struct ip6_hbh *)(ip6 + 1); 712 #else 713 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 714 sizeof(struct ip6_hbh)); 715 if (hbh == NULL) { 716 ip6stat.ip6s_tooshort++; 717 return; 718 } 719 #endif 720 nxt = hbh->ip6h_nxt; 721 722 /* 723 * accept the packet if a router alert option is included 724 * and we act as an IPv6 router. 725 */ 726 if (rtalert != ~0 && ip6_forwarding) 727 ours = 1; 728 } else 729 nxt = ip6->ip6_nxt; 730 731 /* 732 * Check that the amount of data in the buffers 733 * is as at least much as the IPv6 header would have us expect. 734 * Trim mbufs if longer than we expect. 735 * Drop packet if shorter than we expect. 736 */ 737 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 738 ip6stat.ip6s_tooshort++; 739 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 740 goto bad; 741 } 742 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 743 if (m->m_len == m->m_pkthdr.len) { 744 m->m_len = sizeof(struct ip6_hdr) + plen; 745 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 746 } else 747 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 748 } 749 750 /* 751 * Forward if desirable. 752 */ 753 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 754 /* 755 * If we are acting as a multicast router, all 756 * incoming multicast packets are passed to the 757 * kernel-level multicast forwarding function. 758 * The packet is returned (relatively) intact; if 759 * ip6_mforward() returns a non-zero value, the packet 760 * must be discarded, else it may be accepted below. 761 */ 762 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 763 ip6stat.ip6s_cantforward++; 764 m_freem(m); 765 return; 766 } 767 if (!ours) { 768 m_freem(m); 769 return; 770 } 771 } else if (!ours) { 772 ip6_forward(m, 0); 773 return; 774 } 775 776 ip6 = mtod(m, struct ip6_hdr *); 777 778 /* 779 * Malicious party may be able to use IPv4 mapped addr to confuse 780 * tcp/udp stack and bypass security checks (act as if it was from 781 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 782 * 783 * For SIIT end node behavior, you may want to disable the check. 784 * However, you will become vulnerable to attacks using IPv4 mapped 785 * source. 786 */ 787 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 788 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 789 ip6stat.ip6s_badscope++; 790 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 791 goto bad; 792 } 793 794 /* 795 * Tell launch routine the next header 796 */ 797 ip6stat.ip6s_delivered++; 798 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 799 nest = 0; 800 801 while (nxt != IPPROTO_DONE) { 802 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 803 ip6stat.ip6s_toomanyhdr++; 804 goto bad; 805 } 806 807 /* 808 * protection against faulty packet - there should be 809 * more sanity checks in header chain processing. 810 */ 811 if (m->m_pkthdr.len < off) { 812 ip6stat.ip6s_tooshort++; 813 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 814 goto bad; 815 } 816 817 #if 0 818 /* 819 * do we need to do it for every header? yeah, other 820 * functions can play with it (like re-allocate and copy). 821 */ 822 mhist = ip6_addaux(m); 823 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 824 hist = mtod(mhist, caddr_t) + mhist->m_len; 825 bcopy(&nxt, hist, sizeof(nxt)); 826 mhist->m_len += sizeof(nxt); 827 } else { 828 ip6stat.ip6s_toomanyhdr++; 829 goto bad; 830 } 831 #endif 832 833 #ifdef IPSEC 834 /* 835 * enforce IPsec policy checking if we are seeing last header. 836 * note that we do not visit this with protocols with pcb layer 837 * code - like udp/tcp/raw ip. 838 */ 839 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 840 ipsec6_in_reject(m, NULL)) { 841 ipsec6stat.in_polvio++; 842 goto bad; 843 } 844 #endif 845 846 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 847 } 848 return; 849 bad: 850 m_freem(m); 851 } 852 853 /* 854 * set/grab in6_ifaddr correspond to IPv6 destination address. 855 * XXX backward compatibility wrapper 856 */ 857 static struct ip6aux * 858 ip6_setdstifaddr(m, ia6) 859 struct mbuf *m; 860 struct in6_ifaddr *ia6; 861 { 862 struct ip6aux *n; 863 864 n = ip6_addaux(m); 865 if (n) 866 n->ip6a_dstia6 = ia6; 867 return n; /* NULL if failed to set */ 868 } 869 870 struct in6_ifaddr * 871 ip6_getdstifaddr(m) 872 struct mbuf *m; 873 { 874 struct ip6aux *n; 875 876 n = ip6_findaux(m); 877 if (n) 878 return n->ip6a_dstia6; 879 else 880 return NULL; 881 } 882 883 /* 884 * Hop-by-Hop options header processing. If a valid jumbo payload option is 885 * included, the real payload length will be stored in plenp. 886 */ 887 static int 888 ip6_hopopts_input(plenp, rtalertp, mp, offp) 889 u_int32_t *plenp; 890 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 891 struct mbuf **mp; 892 int *offp; 893 { 894 struct mbuf *m = *mp; 895 int off = *offp, hbhlen; 896 struct ip6_hbh *hbh; 897 u_int8_t *opt; 898 899 /* validation of the length of the header */ 900 #ifndef PULLDOWN_TEST 901 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 902 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 903 hbhlen = (hbh->ip6h_len + 1) << 3; 904 905 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 906 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 907 #else 908 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 909 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 910 if (hbh == NULL) { 911 ip6stat.ip6s_tooshort++; 912 return -1; 913 } 914 hbhlen = (hbh->ip6h_len + 1) << 3; 915 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 916 hbhlen); 917 if (hbh == NULL) { 918 ip6stat.ip6s_tooshort++; 919 return -1; 920 } 921 #endif 922 off += hbhlen; 923 hbhlen -= sizeof(struct ip6_hbh); 924 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 925 926 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 927 hbhlen, rtalertp, plenp) < 0) 928 return(-1); 929 930 *offp = off; 931 *mp = m; 932 return(0); 933 } 934 935 /* 936 * Search header for all Hop-by-hop options and process each option. 937 * This function is separate from ip6_hopopts_input() in order to 938 * handle a case where the sending node itself process its hop-by-hop 939 * options header. In such a case, the function is called from ip6_output(). 940 * 941 * The function assumes that hbh header is located right after the IPv6 header 942 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 943 * opthead + hbhlen is located in continuous memory region. 944 */ 945 int 946 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 947 struct mbuf *m; 948 u_int8_t *opthead; 949 int hbhlen; 950 u_int32_t *rtalertp; 951 u_int32_t *plenp; 952 { 953 struct ip6_hdr *ip6; 954 int optlen = 0; 955 u_int8_t *opt = opthead; 956 u_int16_t rtalert_val; 957 u_int32_t jumboplen; 958 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 959 960 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 961 switch (*opt) { 962 case IP6OPT_PAD1: 963 optlen = 1; 964 break; 965 case IP6OPT_PADN: 966 if (hbhlen < IP6OPT_MINLEN) { 967 ip6stat.ip6s_toosmall++; 968 goto bad; 969 } 970 optlen = *(opt + 1) + 2; 971 break; 972 case IP6OPT_RTALERT: 973 /* XXX may need check for alignment */ 974 if (hbhlen < IP6OPT_RTALERT_LEN) { 975 ip6stat.ip6s_toosmall++; 976 goto bad; 977 } 978 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 979 /* XXX stat */ 980 icmp6_error(m, ICMP6_PARAM_PROB, 981 ICMP6_PARAMPROB_HEADER, 982 erroff + opt + 1 - opthead); 983 return(-1); 984 } 985 optlen = IP6OPT_RTALERT_LEN; 986 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 987 *rtalertp = ntohs(rtalert_val); 988 break; 989 case IP6OPT_JUMBO: 990 /* XXX may need check for alignment */ 991 if (hbhlen < IP6OPT_JUMBO_LEN) { 992 ip6stat.ip6s_toosmall++; 993 goto bad; 994 } 995 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 996 /* XXX stat */ 997 icmp6_error(m, ICMP6_PARAM_PROB, 998 ICMP6_PARAMPROB_HEADER, 999 erroff + opt + 1 - opthead); 1000 return(-1); 1001 } 1002 optlen = IP6OPT_JUMBO_LEN; 1003 1004 /* 1005 * IPv6 packets that have non 0 payload length 1006 * must not contain a jumbo payload option. 1007 */ 1008 ip6 = mtod(m, struct ip6_hdr *); 1009 if (ip6->ip6_plen) { 1010 ip6stat.ip6s_badoptions++; 1011 icmp6_error(m, ICMP6_PARAM_PROB, 1012 ICMP6_PARAMPROB_HEADER, 1013 erroff + opt - opthead); 1014 return(-1); 1015 } 1016 1017 /* 1018 * We may see jumbolen in unaligned location, so 1019 * we'd need to perform bcopy(). 1020 */ 1021 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1022 jumboplen = (u_int32_t)htonl(jumboplen); 1023 1024 #if 1 1025 /* 1026 * if there are multiple jumbo payload options, 1027 * *plenp will be non-zero and the packet will be 1028 * rejected. 1029 * the behavior may need some debate in ipngwg - 1030 * multiple options does not make sense, however, 1031 * there's no explicit mention in specification. 1032 */ 1033 if (*plenp != 0) { 1034 ip6stat.ip6s_badoptions++; 1035 icmp6_error(m, ICMP6_PARAM_PROB, 1036 ICMP6_PARAMPROB_HEADER, 1037 erroff + opt + 2 - opthead); 1038 return(-1); 1039 } 1040 #endif 1041 1042 /* 1043 * jumbo payload length must be larger than 65535. 1044 */ 1045 if (jumboplen <= IPV6_MAXPACKET) { 1046 ip6stat.ip6s_badoptions++; 1047 icmp6_error(m, ICMP6_PARAM_PROB, 1048 ICMP6_PARAMPROB_HEADER, 1049 erroff + opt + 2 - opthead); 1050 return(-1); 1051 } 1052 *plenp = jumboplen; 1053 1054 break; 1055 default: /* unknown option */ 1056 if (hbhlen < IP6OPT_MINLEN) { 1057 ip6stat.ip6s_toosmall++; 1058 goto bad; 1059 } 1060 optlen = ip6_unknown_opt(opt, m, 1061 erroff + opt - opthead); 1062 if (optlen == -1) 1063 return(-1); 1064 optlen += 2; 1065 break; 1066 } 1067 } 1068 1069 return(0); 1070 1071 bad: 1072 m_freem(m); 1073 return(-1); 1074 } 1075 1076 /* 1077 * Unknown option processing. 1078 * The third argument `off' is the offset from the IPv6 header to the option, 1079 * which is necessary if the IPv6 header the and option header and IPv6 header 1080 * is not continuous in order to return an ICMPv6 error. 1081 */ 1082 int 1083 ip6_unknown_opt(optp, m, off) 1084 u_int8_t *optp; 1085 struct mbuf *m; 1086 int off; 1087 { 1088 struct ip6_hdr *ip6; 1089 1090 switch (IP6OPT_TYPE(*optp)) { 1091 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1092 return((int)*(optp + 1)); 1093 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1094 m_freem(m); 1095 return(-1); 1096 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1097 ip6stat.ip6s_badoptions++; 1098 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1099 return(-1); 1100 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1101 ip6stat.ip6s_badoptions++; 1102 ip6 = mtod(m, struct ip6_hdr *); 1103 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1104 (m->m_flags & (M_BCAST|M_MCAST))) 1105 m_freem(m); 1106 else 1107 icmp6_error(m, ICMP6_PARAM_PROB, 1108 ICMP6_PARAMPROB_OPTION, off); 1109 return(-1); 1110 } 1111 1112 m_freem(m); /* XXX: NOTREACHED */ 1113 return(-1); 1114 } 1115 1116 /* 1117 * Create the "control" list for this pcb. 1118 * The function will not modify mbuf chain at all. 1119 * 1120 * with KAME mbuf chain restriction: 1121 * The routine will be called from upper layer handlers like tcp6_input(). 1122 * Thus the routine assumes that the caller (tcp6_input) have already 1123 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1124 * very first mbuf on the mbuf chain. 1125 */ 1126 void 1127 ip6_savecontrol(in6p, mp, ip6, m) 1128 struct inpcb *in6p; 1129 struct mbuf **mp; 1130 struct ip6_hdr *ip6; 1131 struct mbuf *m; 1132 { 1133 struct thread *td = curthread; /* XXX */ 1134 int privileged = 0; 1135 int rthdr_exist = 0; 1136 1137 1138 if (suser(td) == 0) 1139 privileged++; 1140 1141 #ifdef SO_TIMESTAMP 1142 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1143 struct timeval tv; 1144 1145 microtime(&tv); 1146 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1147 SCM_TIMESTAMP, SOL_SOCKET); 1148 if (*mp) { 1149 mp = &(*mp)->m_next; 1150 } 1151 } 1152 #endif 1153 1154 /* RFC 2292 sec. 5 */ 1155 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1156 struct in6_pktinfo pi6; 1157 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1158 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1159 pi6.ipi6_addr.s6_addr16[1] = 0; 1160 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1161 ? m->m_pkthdr.rcvif->if_index 1162 : 0; 1163 *mp = sbcreatecontrol((caddr_t) &pi6, 1164 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1165 IPPROTO_IPV6); 1166 if (*mp) 1167 mp = &(*mp)->m_next; 1168 } 1169 1170 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1171 int hlim = ip6->ip6_hlim & 0xff; 1172 *mp = sbcreatecontrol((caddr_t) &hlim, 1173 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1174 if (*mp) 1175 mp = &(*mp)->m_next; 1176 } 1177 1178 /* 1179 * IPV6_HOPOPTS socket option. We require super-user privilege 1180 * for the option, but it might be too strict, since there might 1181 * be some hop-by-hop options which can be returned to normal user. 1182 * See RFC 2292 section 6. 1183 */ 1184 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { 1185 /* 1186 * Check if a hop-by-hop options header is contatined in the 1187 * received packet, and if so, store the options as ancillary 1188 * data. Note that a hop-by-hop options header must be 1189 * just after the IPv6 header, which fact is assured through 1190 * the IPv6 input processing. 1191 */ 1192 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1193 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1194 struct ip6_hbh *hbh; 1195 int hbhlen = 0; 1196 #ifdef PULLDOWN_TEST 1197 struct mbuf *ext; 1198 #endif 1199 1200 #ifndef PULLDOWN_TEST 1201 hbh = (struct ip6_hbh *)(ip6 + 1); 1202 hbhlen = (hbh->ip6h_len + 1) << 3; 1203 #else 1204 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1205 ip6->ip6_nxt); 1206 if (ext == NULL) { 1207 ip6stat.ip6s_tooshort++; 1208 return; 1209 } 1210 hbh = mtod(ext, struct ip6_hbh *); 1211 hbhlen = (hbh->ip6h_len + 1) << 3; 1212 if (hbhlen != ext->m_len) { 1213 m_freem(ext); 1214 ip6stat.ip6s_tooshort++; 1215 return; 1216 } 1217 #endif 1218 1219 /* 1220 * XXX: We copy whole the header even if a jumbo 1221 * payload option is included, which option is to 1222 * be removed before returning in the RFC 2292. 1223 * Note: this constraint is removed in 2292bis. 1224 */ 1225 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1226 IPV6_HOPOPTS, IPPROTO_IPV6); 1227 if (*mp) 1228 mp = &(*mp)->m_next; 1229 #ifdef PULLDOWN_TEST 1230 m_freem(ext); 1231 #endif 1232 } 1233 } 1234 1235 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1236 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1237 int proto, off, nxt; 1238 1239 /* 1240 * go through the header chain to see if a routing header is 1241 * contained in the packet. We need this information to store 1242 * destination options headers (if any) properly. 1243 * XXX: performance issue. We should record this info when 1244 * processing extension headers in incoming routine. 1245 * (todo) use m_aux? 1246 */ 1247 proto = IPPROTO_IPV6; 1248 off = 0; 1249 nxt = -1; 1250 while (1) { 1251 int newoff; 1252 1253 newoff = ip6_nexthdr(m, off, proto, &nxt); 1254 if (newoff < 0) 1255 break; 1256 if (newoff < off) /* invalid, check for safety */ 1257 break; 1258 if ((proto = nxt) == IPPROTO_ROUTING) { 1259 rthdr_exist = 1; 1260 break; 1261 } 1262 off = newoff; 1263 } 1264 } 1265 1266 if ((in6p->in6p_flags & 1267 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1268 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1269 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1270 1271 /* 1272 * Search for destination options headers or routing 1273 * header(s) through the header chain, and stores each 1274 * header as ancillary data. 1275 * Note that the order of the headers remains in 1276 * the chain of ancillary data. 1277 */ 1278 while (1) { /* is explicit loop prevention necessary? */ 1279 struct ip6_ext *ip6e = NULL; 1280 int elen; 1281 #ifdef PULLDOWN_TEST 1282 struct mbuf *ext = NULL; 1283 #endif 1284 1285 /* 1286 * if it is not an extension header, don't try to 1287 * pull it from the chain. 1288 */ 1289 switch (nxt) { 1290 case IPPROTO_DSTOPTS: 1291 case IPPROTO_ROUTING: 1292 case IPPROTO_HOPOPTS: 1293 case IPPROTO_AH: /* is it possible? */ 1294 break; 1295 default: 1296 goto loopend; 1297 } 1298 1299 #ifndef PULLDOWN_TEST 1300 if (off + sizeof(*ip6e) > m->m_len) 1301 goto loopend; 1302 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1303 if (nxt == IPPROTO_AH) 1304 elen = (ip6e->ip6e_len + 2) << 2; 1305 else 1306 elen = (ip6e->ip6e_len + 1) << 3; 1307 if (off + elen > m->m_len) 1308 goto loopend; 1309 #else 1310 ext = ip6_pullexthdr(m, off, nxt); 1311 if (ext == NULL) { 1312 ip6stat.ip6s_tooshort++; 1313 return; 1314 } 1315 ip6e = mtod(ext, struct ip6_ext *); 1316 if (nxt == IPPROTO_AH) 1317 elen = (ip6e->ip6e_len + 2) << 2; 1318 else 1319 elen = (ip6e->ip6e_len + 1) << 3; 1320 if (elen != ext->m_len) { 1321 m_freem(ext); 1322 ip6stat.ip6s_tooshort++; 1323 return; 1324 } 1325 #endif 1326 1327 switch (nxt) { 1328 case IPPROTO_DSTOPTS: 1329 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1330 break; 1331 1332 /* 1333 * We also require super-user privilege for 1334 * the option. 1335 * See the comments on IN6_HOPOPTS. 1336 */ 1337 if (!privileged) 1338 break; 1339 1340 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1341 IPV6_DSTOPTS, 1342 IPPROTO_IPV6); 1343 if (*mp) 1344 mp = &(*mp)->m_next; 1345 break; 1346 case IPPROTO_ROUTING: 1347 if (!in6p->in6p_flags & IN6P_RTHDR) 1348 break; 1349 1350 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1351 IPV6_RTHDR, 1352 IPPROTO_IPV6); 1353 if (*mp) 1354 mp = &(*mp)->m_next; 1355 break; 1356 case IPPROTO_HOPOPTS: 1357 case IPPROTO_AH: /* is it possible? */ 1358 break; 1359 1360 default: 1361 /* 1362 * other cases have been filtered in the above. 1363 * none will visit this case. here we supply 1364 * the code just in case (nxt overwritten or 1365 * other cases). 1366 */ 1367 #ifdef PULLDOWN_TEST 1368 m_freem(ext); 1369 #endif 1370 goto loopend; 1371 1372 } 1373 1374 /* proceed with the next header. */ 1375 off += elen; 1376 nxt = ip6e->ip6e_nxt; 1377 ip6e = NULL; 1378 #ifdef PULLDOWN_TEST 1379 m_freem(ext); 1380 ext = NULL; 1381 #endif 1382 } 1383 loopend: 1384 ; 1385 } 1386 1387 } 1388 1389 #ifdef PULLDOWN_TEST 1390 /* 1391 * pull single extension header from mbuf chain. returns single mbuf that 1392 * contains the result, or NULL on error. 1393 */ 1394 static struct mbuf * 1395 ip6_pullexthdr(m, off, nxt) 1396 struct mbuf *m; 1397 size_t off; 1398 int nxt; 1399 { 1400 struct ip6_ext ip6e; 1401 size_t elen; 1402 struct mbuf *n; 1403 1404 #ifdef DIAGNOSTIC 1405 switch (nxt) { 1406 case IPPROTO_DSTOPTS: 1407 case IPPROTO_ROUTING: 1408 case IPPROTO_HOPOPTS: 1409 case IPPROTO_AH: /* is it possible? */ 1410 break; 1411 default: 1412 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1413 } 1414 #endif 1415 1416 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1417 if (nxt == IPPROTO_AH) 1418 elen = (ip6e.ip6e_len + 2) << 2; 1419 else 1420 elen = (ip6e.ip6e_len + 1) << 3; 1421 1422 MGET(n, M_DONTWAIT, MT_DATA); 1423 if (n && elen >= MLEN) { 1424 MCLGET(n, M_DONTWAIT); 1425 if ((n->m_flags & M_EXT) == 0) { 1426 m_free(n); 1427 n = NULL; 1428 } 1429 } 1430 if (!n) 1431 return NULL; 1432 1433 n->m_len = 0; 1434 if (elen >= M_TRAILINGSPACE(n)) { 1435 m_free(n); 1436 return NULL; 1437 } 1438 1439 m_copydata(m, off, elen, mtod(n, caddr_t)); 1440 n->m_len = elen; 1441 return n; 1442 } 1443 #endif 1444 1445 /* 1446 * Get pointer to the previous header followed by the header 1447 * currently processed. 1448 * XXX: This function supposes that 1449 * M includes all headers, 1450 * the next header field and the header length field of each header 1451 * are valid, and 1452 * the sum of each header length equals to OFF. 1453 * Because of these assumptions, this function must be called very 1454 * carefully. Moreover, it will not be used in the near future when 1455 * we develop `neater' mechanism to process extension headers. 1456 */ 1457 char * 1458 ip6_get_prevhdr(m, off) 1459 struct mbuf *m; 1460 int off; 1461 { 1462 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1463 1464 if (off == sizeof(struct ip6_hdr)) 1465 return(&ip6->ip6_nxt); 1466 else { 1467 int len, nxt; 1468 struct ip6_ext *ip6e = NULL; 1469 1470 nxt = ip6->ip6_nxt; 1471 len = sizeof(struct ip6_hdr); 1472 while (len < off) { 1473 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1474 1475 switch (nxt) { 1476 case IPPROTO_FRAGMENT: 1477 len += sizeof(struct ip6_frag); 1478 break; 1479 case IPPROTO_AH: 1480 len += (ip6e->ip6e_len + 2) << 2; 1481 break; 1482 default: 1483 len += (ip6e->ip6e_len + 1) << 3; 1484 break; 1485 } 1486 nxt = ip6e->ip6e_nxt; 1487 } 1488 if (ip6e) 1489 return(&ip6e->ip6e_nxt); 1490 else 1491 return NULL; 1492 } 1493 } 1494 1495 /* 1496 * get next header offset. m will be retained. 1497 */ 1498 int 1499 ip6_nexthdr(m, off, proto, nxtp) 1500 struct mbuf *m; 1501 int off; 1502 int proto; 1503 int *nxtp; 1504 { 1505 struct ip6_hdr ip6; 1506 struct ip6_ext ip6e; 1507 struct ip6_frag fh; 1508 1509 /* just in case */ 1510 if (m == NULL) 1511 panic("ip6_nexthdr: m == NULL"); 1512 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1513 return -1; 1514 1515 switch (proto) { 1516 case IPPROTO_IPV6: 1517 if (m->m_pkthdr.len < off + sizeof(ip6)) 1518 return -1; 1519 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1520 if (nxtp) 1521 *nxtp = ip6.ip6_nxt; 1522 off += sizeof(ip6); 1523 return off; 1524 1525 case IPPROTO_FRAGMENT: 1526 /* 1527 * terminate parsing if it is not the first fragment, 1528 * it does not make sense to parse through it. 1529 */ 1530 if (m->m_pkthdr.len < off + sizeof(fh)) 1531 return -1; 1532 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1533 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1534 return -1; 1535 if (nxtp) 1536 *nxtp = fh.ip6f_nxt; 1537 off += sizeof(struct ip6_frag); 1538 return off; 1539 1540 case IPPROTO_AH: 1541 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1542 return -1; 1543 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1544 if (nxtp) 1545 *nxtp = ip6e.ip6e_nxt; 1546 off += (ip6e.ip6e_len + 2) << 2; 1547 return off; 1548 1549 case IPPROTO_HOPOPTS: 1550 case IPPROTO_ROUTING: 1551 case IPPROTO_DSTOPTS: 1552 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1553 return -1; 1554 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1555 if (nxtp) 1556 *nxtp = ip6e.ip6e_nxt; 1557 off += (ip6e.ip6e_len + 1) << 3; 1558 return off; 1559 1560 case IPPROTO_NONE: 1561 case IPPROTO_ESP: 1562 case IPPROTO_IPCOMP: 1563 /* give up */ 1564 return -1; 1565 1566 default: 1567 return -1; 1568 } 1569 1570 return -1; 1571 } 1572 1573 /* 1574 * get offset for the last header in the chain. m will be kept untainted. 1575 */ 1576 int 1577 ip6_lasthdr(m, off, proto, nxtp) 1578 struct mbuf *m; 1579 int off; 1580 int proto; 1581 int *nxtp; 1582 { 1583 int newoff; 1584 int nxt; 1585 1586 if (!nxtp) { 1587 nxt = -1; 1588 nxtp = &nxt; 1589 } 1590 while (1) { 1591 newoff = ip6_nexthdr(m, off, proto, nxtp); 1592 if (newoff < 0) 1593 return off; 1594 else if (newoff < off) 1595 return -1; /* invalid */ 1596 else if (newoff == off) 1597 return newoff; 1598 1599 off = newoff; 1600 proto = *nxtp; 1601 } 1602 } 1603 1604 struct ip6aux * 1605 ip6_addaux(m) 1606 struct mbuf *m; 1607 { 1608 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1609 if (!tag) { 1610 tag = m_tag_get(PACKET_TAG_IPV6_INPUT, 1611 sizeof (struct ip6aux), 1612 M_NOWAIT); 1613 if (tag) 1614 m_tag_prepend(m, tag); 1615 } 1616 if (tag) 1617 bzero(tag+1, sizeof (struct ip6aux)); 1618 return tag ? (struct ip6aux*)(tag+1) : NULL; 1619 } 1620 1621 struct ip6aux * 1622 ip6_findaux(m) 1623 struct mbuf *m; 1624 { 1625 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1626 return tag ? (struct ip6aux*)(tag+1) : NULL; 1627 } 1628 1629 void 1630 ip6_delaux(m) 1631 struct mbuf *m; 1632 { 1633 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1634 if (tag) 1635 m_tag_delete(m, tag); 1636 } 1637 1638 /* 1639 * System control for IP6 1640 */ 1641 1642 u_char inet6ctlerrmap[PRC_NCMDS] = { 1643 0, 0, 0, 0, 1644 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1645 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1646 EMSGSIZE, EHOSTUNREACH, 0, 0, 1647 0, 0, 0, 0, 1648 ENOPROTOOPT 1649 }; 1650