1 /* $FreeBSD$ */ 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 #include "opt_pfil_hooks.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/proc.h> 79 #include <sys/domain.h> 80 #include <sys/protosw.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/errno.h> 84 #include <sys/time.h> 85 #include <sys/kernel.h> 86 #include <sys/syslog.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 #ifdef PFIL_HOOKS 95 #include <net/pfil.h> 96 #endif 97 98 #include <netinet/in.h> 99 #include <netinet/in_systm.h> 100 #ifdef INET 101 #include <netinet/ip.h> 102 #include <netinet/ip_icmp.h> 103 #endif /* INET */ 104 #include <netinet/ip6.h> 105 #include <netinet6/in6_var.h> 106 #include <netinet6/ip6_var.h> 107 #include <netinet/in_pcb.h> 108 #include <netinet/icmp6.h> 109 #include <netinet6/in6_ifattach.h> 110 #include <netinet6/nd6.h> 111 #include <netinet6/in6_prefix.h> 112 113 #ifdef IPSEC 114 #include <netinet6/ipsec.h> 115 #ifdef INET6 116 #include <netinet6/ipsec6.h> 117 #endif 118 #endif 119 120 #include <netinet6/ip6_fw.h> 121 122 #include <netinet6/ip6protosw.h> 123 124 #include <net/net_osdep.h> 125 126 extern struct domain inet6domain; 127 128 u_char ip6_protox[IPPROTO_MAX]; 129 static int ip6qmaxlen = IFQ_MAXLEN; 130 struct in6_ifaddr *in6_ifaddr; 131 132 extern struct callout in6_tmpaddrtimer_ch; 133 134 int ip6_forward_srcrt; /* XXX */ 135 int ip6_sourcecheck; /* XXX */ 136 int ip6_sourcecheck_interval; /* XXX */ 137 138 int ip6_ours_check_algorithm; 139 140 141 /* firewall hooks */ 142 ip6_fw_chk_t *ip6_fw_chk_ptr; 143 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 144 int ip6_fw_enable = 1; 145 146 struct ip6stat ip6stat; 147 148 static void ip6_init2 __P((void *)); 149 static struct mbuf *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 150 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 151 #ifdef PULLDOWN_TEST 152 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 153 #endif 154 155 156 /* 157 * IP6 initialization: fill in IP6 protocol switch table. 158 * All protocols not implemented in kernel go to raw IP6 protocol handler. 159 */ 160 void 161 ip6_init() 162 { 163 struct ip6protosw *pr; 164 int i; 165 struct timeval tv; 166 167 #ifdef DIAGNOSTIC 168 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 169 panic("sizeof(protosw) != sizeof(ip6protosw)"); 170 #endif 171 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 172 if (pr == 0) 173 panic("ip6_init"); 174 for (i = 0; i < IPPROTO_MAX; i++) 175 ip6_protox[i] = pr - inet6sw; 176 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 177 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 178 if (pr->pr_domain->dom_family == PF_INET6 && 179 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 180 ip6_protox[pr->pr_protocol] = pr - inet6sw; 181 ip6intrq.ifq_maxlen = ip6qmaxlen; 182 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); 183 ip6intrq_present = 1; 184 register_netisr(NETISR_IPV6, ip6intr); 185 nd6_init(); 186 frag6_init(); 187 /* 188 * in many cases, random() here does NOT return random number 189 * as initialization during bootstrap time occur in fixed order. 190 */ 191 microtime(&tv); 192 ip6_flow_seq = random() ^ tv.tv_usec; 193 microtime(&tv); 194 ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 195 } 196 197 static void 198 ip6_init2(dummy) 199 void *dummy; 200 { 201 202 /* 203 * to route local address of p2p link to loopback, 204 * assign loopback address first. 205 */ 206 in6_ifattach(&loif[0], NULL); 207 208 /* nd6_timer_init */ 209 callout_init(&nd6_timer_ch, 0); 210 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 211 212 /* router renumbering prefix list maintenance */ 213 callout_init(&in6_rr_timer_ch, 0); 214 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 215 216 /* timer for regeneranation of temporary addresses randomize ID */ 217 callout_reset(&in6_tmpaddrtimer_ch, 218 (ip6_temp_preferred_lifetime - ip6_desync_factor - 219 ip6_temp_regen_advance) * hz, 220 in6_tmpaddrtimer, NULL); 221 } 222 223 /* cheat */ 224 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 225 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 226 227 /* 228 * IP6 input interrupt handling. Just pass the packet to ip6_input. 229 */ 230 void 231 ip6intr() 232 { 233 int s; 234 struct mbuf *m; 235 236 for (;;) { 237 s = splimp(); 238 IF_DEQUEUE(&ip6intrq, m); 239 splx(s); 240 if (m == 0) 241 return; 242 ip6_input(m); 243 } 244 } 245 246 extern struct route_in6 ip6_forward_rt; 247 248 void 249 ip6_input(m) 250 struct mbuf *m; 251 { 252 struct ip6_hdr *ip6; 253 int off = sizeof(struct ip6_hdr), nest; 254 u_int32_t plen; 255 u_int32_t rtalert = ~0; 256 int nxt, ours = 0; 257 struct ifnet *deliverifp = NULL; 258 #ifdef PFIL_HOOKS 259 struct packet_filter_hook *pfh; 260 struct mbuf *m0; 261 int rv; 262 #endif /* PFIL_HOOKS */ 263 264 #ifdef IPSEC 265 /* 266 * should the inner packet be considered authentic? 267 * see comment in ah4_input(). 268 */ 269 if (m) { 270 m->m_flags &= ~M_AUTHIPHDR; 271 m->m_flags &= ~M_AUTHIPDGM; 272 } 273 #endif 274 275 /* 276 * make sure we don't have onion peering information into m_aux. 277 */ 278 ip6_delaux(m); 279 280 /* 281 * mbuf statistics 282 */ 283 if (m->m_flags & M_EXT) { 284 if (m->m_next) 285 ip6stat.ip6s_mext2m++; 286 else 287 ip6stat.ip6s_mext1++; 288 } else { 289 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 290 if (m->m_next) { 291 if (m->m_flags & M_LOOP) { 292 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 293 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 294 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 295 else 296 ip6stat.ip6s_m2m[0]++; 297 } else 298 ip6stat.ip6s_m1++; 299 #undef M2MMAX 300 } 301 302 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 303 ip6stat.ip6s_total++; 304 305 #ifndef PULLDOWN_TEST 306 /* 307 * L2 bridge code and some other code can return mbuf chain 308 * that does not conform to KAME requirement. too bad. 309 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 310 */ 311 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 312 struct mbuf *n; 313 314 MGETHDR(n, M_DONTWAIT, MT_HEADER); 315 if (n) 316 M_COPY_PKTHDR(n, m); 317 if (n && m->m_pkthdr.len > MHLEN) { 318 MCLGET(n, M_DONTWAIT); 319 if ((n->m_flags & M_EXT) == 0) { 320 m_freem(n); 321 n = NULL; 322 } 323 } 324 if (n == NULL) { 325 m_freem(m); 326 return; /*ENOBUFS*/ 327 } 328 329 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 330 n->m_len = m->m_pkthdr.len; 331 m_freem(m); 332 m = n; 333 } 334 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 335 #endif 336 337 if (m->m_len < sizeof(struct ip6_hdr)) { 338 struct ifnet *inifp; 339 inifp = m->m_pkthdr.rcvif; 340 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 341 ip6stat.ip6s_toosmall++; 342 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 343 return; 344 } 345 } 346 347 ip6 = mtod(m, struct ip6_hdr *); 348 349 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 350 ip6stat.ip6s_badvers++; 351 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 352 goto bad; 353 } 354 355 #ifdef PFIL_HOOKS 356 /* 357 * Run through list of hooks for input packets. If there are any 358 * filters which require that additional packets in the flow are 359 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 360 * Note that filters must _never_ set this flag, as another filter 361 * in the list may have previously cleared it. 362 */ 363 m0 = m; 364 pfh = pfil_hook_get(PFIL_IN, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); 365 for (; pfh; pfh = pfh->pfil_link.tqe_next) 366 if (pfh->pfil_func) { 367 rv = pfh->pfil_func(ip6, sizeof(*ip6), 368 m->m_pkthdr.rcvif, 0, &m0); 369 if (rv) 370 return; 371 m = m0; 372 if (m == NULL) 373 return; 374 ip6 = mtod(m, struct ip6_hdr *); 375 } 376 #endif /* PFIL_HOOKS */ 377 378 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 379 380 /* 381 * Check with the firewall... 382 */ 383 if (ip6_fw_enable && ip6_fw_chk_ptr) { 384 u_short port = 0; 385 /* If ipfw says divert, we have to just drop packet */ 386 /* use port as a dummy argument */ 387 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 388 m_freem(m); 389 m = NULL; 390 } 391 if (!m) 392 return; 393 } 394 395 /* 396 * Check against address spoofing/corruption. 397 */ 398 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 399 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 400 /* 401 * XXX: "badscope" is not very suitable for a multicast source. 402 */ 403 ip6stat.ip6s_badscope++; 404 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 405 goto bad; 406 } 407 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 408 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 409 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 410 ip6stat.ip6s_badscope++; 411 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 412 goto bad; 413 } 414 415 /* 416 * The following check is not documented in specs. A malicious 417 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 418 * and bypass security checks (act as if it was from 127.0.0.1 by using 419 * IPv6 src ::ffff:127.0.0.1). Be cautious. 420 * 421 * This check chokes if we are in an SIIT cloud. As none of BSDs 422 * support IPv4-less kernel compilation, we cannot support SIIT 423 * environment at all. So, it makes more sense for us to reject any 424 * malicious packets for non-SIIT environment, than try to do a 425 * partical support for SIIT environment. 426 */ 427 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 428 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 429 ip6stat.ip6s_badscope++; 430 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 431 goto bad; 432 } 433 #if 0 434 /* 435 * Reject packets with IPv4 compatible addresses (auto tunnel). 436 * 437 * The code forbids auto tunnel relay case in RFC1933 (the check is 438 * stronger than RFC1933). We may want to re-enable it if mech-xx 439 * is revised to forbid relaying case. 440 */ 441 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 442 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 443 ip6stat.ip6s_badscope++; 444 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 445 goto bad; 446 } 447 #endif 448 449 /* drop packets if interface ID portion is already filled */ 450 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 451 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 452 ip6->ip6_src.s6_addr16[1]) { 453 ip6stat.ip6s_badscope++; 454 goto bad; 455 } 456 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 457 ip6->ip6_dst.s6_addr16[1]) { 458 ip6stat.ip6s_badscope++; 459 goto bad; 460 } 461 } 462 463 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 464 ip6->ip6_src.s6_addr16[1] 465 = htons(m->m_pkthdr.rcvif->if_index); 466 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 467 ip6->ip6_dst.s6_addr16[1] 468 = htons(m->m_pkthdr.rcvif->if_index); 469 470 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 471 /* 472 * We use rt->rt_ifp to determine if the address is ours or not. 473 * If rt_ifp is lo0, the address is ours. 474 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 475 * so any address under fe80::%lo0/64 will be mistakenly considered 476 * local. The special case is supplied to handle the case properly 477 * by actually looking at interface addresses 478 * (using in6ifa_ifpwithaddr). 479 */ 480 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 481 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 482 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 483 icmp6_error(m, ICMP6_DST_UNREACH, 484 ICMP6_DST_UNREACH_ADDR, 0); 485 /* m is already freed */ 486 return; 487 } 488 489 ours = 1; 490 deliverifp = m->m_pkthdr.rcvif; 491 goto hbhcheck; 492 } 493 #endif 494 495 /* 496 * Multicast check 497 */ 498 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 499 struct in6_multi *in6m = 0; 500 501 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 502 /* 503 * See if we belong to the destination multicast group on the 504 * arrival interface. 505 */ 506 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 507 if (in6m) 508 ours = 1; 509 else if (!ip6_mrouter) { 510 ip6stat.ip6s_notmember++; 511 ip6stat.ip6s_cantforward++; 512 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 513 goto bad; 514 } 515 deliverifp = m->m_pkthdr.rcvif; 516 goto hbhcheck; 517 } 518 519 /* 520 * Unicast check 521 */ 522 switch (ip6_ours_check_algorithm) { 523 default: 524 /* 525 * XXX: I intentionally broke our indentation rule here, 526 * since this switch-case is just for measurement and 527 * therefore should soon be removed. 528 */ 529 if (ip6_forward_rt.ro_rt != NULL && 530 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 531 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 532 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 533 ip6stat.ip6s_forward_cachehit++; 534 else { 535 struct sockaddr_in6 *dst6; 536 537 if (ip6_forward_rt.ro_rt) { 538 /* route is down or destination is different */ 539 ip6stat.ip6s_forward_cachemiss++; 540 RTFREE(ip6_forward_rt.ro_rt); 541 ip6_forward_rt.ro_rt = 0; 542 } 543 544 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 545 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 546 dst6->sin6_len = sizeof(struct sockaddr_in6); 547 dst6->sin6_family = AF_INET6; 548 dst6->sin6_addr = ip6->ip6_dst; 549 #ifdef SCOPEDROUTING 550 ip6_forward_rt.ro_dst.sin6_scope_id = 551 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 552 #endif 553 554 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 555 } 556 557 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 558 559 /* 560 * Accept the packet if the forwarding interface to the destination 561 * according to the routing table is the loopback interface, 562 * unless the associated route has a gateway. 563 * Note that this approach causes to accept a packet if there is a 564 * route to the loopback interface for the destination of the packet. 565 * But we think it's even useful in some situations, e.g. when using 566 * a special daemon which wants to intercept the packet. 567 * 568 * XXX: some OSes automatically make a cloned route for the destination 569 * of an outgoing packet. If the outgoing interface of the packet 570 * is a loopback one, the kernel would consider the packet to be 571 * accepted, even if we have no such address assinged on the interface. 572 * We check the cloned flag of the route entry to reject such cases, 573 * assuming that route entries for our own addresses are not made by 574 * cloning (it should be true because in6_addloop explicitly installs 575 * the host route). However, we might have to do an explicit check 576 * while it would be less efficient. Or, should we rather install a 577 * reject route for such a case? 578 */ 579 if (ip6_forward_rt.ro_rt && 580 (ip6_forward_rt.ro_rt->rt_flags & 581 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 582 #ifdef RTF_WASCLONED 583 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 584 #endif 585 #ifdef RTF_CLONED 586 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 587 #endif 588 #if 0 589 /* 590 * The check below is redundant since the comparison of 591 * the destination and the key of the rtentry has 592 * already done through looking up the routing table. 593 */ 594 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 595 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 596 #endif 597 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 598 struct in6_ifaddr *ia6 = 599 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 600 601 /* 602 * record address information into m_aux. 603 */ 604 (void)ip6_setdstifaddr(m, ia6); 605 606 /* 607 * packets to a tentative, duplicated, or somehow invalid 608 * address must not be accepted. 609 */ 610 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 611 /* this address is ready */ 612 ours = 1; 613 deliverifp = ia6->ia_ifp; /* correct? */ 614 /* Count the packet in the ip address stats */ 615 ia6->ia_ifa.if_ipackets++; 616 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 617 goto hbhcheck; 618 } else { 619 /* address is not ready, so discard the packet. */ 620 nd6log((LOG_INFO, 621 "ip6_input: packet to an unready address %s->%s\n", 622 ip6_sprintf(&ip6->ip6_src), 623 ip6_sprintf(&ip6->ip6_dst))); 624 625 goto bad; 626 } 627 } 628 } /* XXX indentation (see above) */ 629 630 /* 631 * FAITH(Firewall Aided Internet Translator) 632 */ 633 if (ip6_keepfaith) { 634 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 635 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 636 /* XXX do we need more sanity checks? */ 637 ours = 1; 638 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 639 goto hbhcheck; 640 } 641 } 642 643 /* 644 * Now there is no reason to process the packet if it's not our own 645 * and we're not a router. 646 */ 647 if (!ip6_forwarding) { 648 ip6stat.ip6s_cantforward++; 649 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 650 goto bad; 651 } 652 653 hbhcheck: 654 /* 655 * record address information into m_aux, if we don't have one yet. 656 * note that we are unable to record it, if the address is not listed 657 * as our interface address (e.g. multicast addresses, addresses 658 * within FAITH prefixes and such). 659 */ 660 if (deliverifp && !ip6_getdstifaddr(m)) { 661 struct in6_ifaddr *ia6; 662 663 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 664 if (ia6) { 665 if (!ip6_setdstifaddr(m, ia6)) { 666 /* 667 * XXX maybe we should drop the packet here, 668 * as we could not provide enough information 669 * to the upper layers. 670 */ 671 } 672 } 673 } 674 675 /* 676 * Process Hop-by-Hop options header if it's contained. 677 * m may be modified in ip6_hopopts_input(). 678 * If a JumboPayload option is included, plen will also be modified. 679 */ 680 plen = (u_int32_t)ntohs(ip6->ip6_plen); 681 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 682 struct ip6_hbh *hbh; 683 684 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 685 #if 0 /*touches NULL pointer*/ 686 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 687 #endif 688 return; /* m have already been freed */ 689 } 690 691 /* adjust pointer */ 692 ip6 = mtod(m, struct ip6_hdr *); 693 694 /* 695 * if the payload length field is 0 and the next header field 696 * indicates Hop-by-Hop Options header, then a Jumbo Payload 697 * option MUST be included. 698 */ 699 if (ip6->ip6_plen == 0 && plen == 0) { 700 /* 701 * Note that if a valid jumbo payload option is 702 * contained, ip6_hoptops_input() must set a valid 703 * (non-zero) payload length to the variable plen. 704 */ 705 ip6stat.ip6s_badoptions++; 706 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 707 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 708 icmp6_error(m, ICMP6_PARAM_PROB, 709 ICMP6_PARAMPROB_HEADER, 710 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 711 return; 712 } 713 #ifndef PULLDOWN_TEST 714 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 715 hbh = (struct ip6_hbh *)(ip6 + 1); 716 #else 717 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 718 sizeof(struct ip6_hbh)); 719 if (hbh == NULL) { 720 ip6stat.ip6s_tooshort++; 721 return; 722 } 723 #endif 724 nxt = hbh->ip6h_nxt; 725 726 /* 727 * accept the packet if a router alert option is included 728 * and we act as an IPv6 router. 729 */ 730 if (rtalert != ~0 && ip6_forwarding) 731 ours = 1; 732 } else 733 nxt = ip6->ip6_nxt; 734 735 /* 736 * Check that the amount of data in the buffers 737 * is as at least much as the IPv6 header would have us expect. 738 * Trim mbufs if longer than we expect. 739 * Drop packet if shorter than we expect. 740 */ 741 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 742 ip6stat.ip6s_tooshort++; 743 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 744 goto bad; 745 } 746 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 747 if (m->m_len == m->m_pkthdr.len) { 748 m->m_len = sizeof(struct ip6_hdr) + plen; 749 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 750 } else 751 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 752 } 753 754 /* 755 * Forward if desirable. 756 */ 757 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 758 /* 759 * If we are acting as a multicast router, all 760 * incoming multicast packets are passed to the 761 * kernel-level multicast forwarding function. 762 * The packet is returned (relatively) intact; if 763 * ip6_mforward() returns a non-zero value, the packet 764 * must be discarded, else it may be accepted below. 765 */ 766 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 767 ip6stat.ip6s_cantforward++; 768 m_freem(m); 769 return; 770 } 771 if (!ours) { 772 m_freem(m); 773 return; 774 } 775 } else if (!ours) { 776 ip6_forward(m, 0); 777 return; 778 } 779 780 ip6 = mtod(m, struct ip6_hdr *); 781 782 /* 783 * Malicious party may be able to use IPv4 mapped addr to confuse 784 * tcp/udp stack and bypass security checks (act as if it was from 785 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 786 * 787 * For SIIT end node behavior, you may want to disable the check. 788 * However, you will become vulnerable to attacks using IPv4 mapped 789 * source. 790 */ 791 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 792 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 793 ip6stat.ip6s_badscope++; 794 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 795 goto bad; 796 } 797 798 /* 799 * Tell launch routine the next header 800 */ 801 ip6stat.ip6s_delivered++; 802 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 803 nest = 0; 804 805 while (nxt != IPPROTO_DONE) { 806 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 807 ip6stat.ip6s_toomanyhdr++; 808 goto bad; 809 } 810 811 /* 812 * protection against faulty packet - there should be 813 * more sanity checks in header chain processing. 814 */ 815 if (m->m_pkthdr.len < off) { 816 ip6stat.ip6s_tooshort++; 817 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 818 goto bad; 819 } 820 821 #if 0 822 /* 823 * do we need to do it for every header? yeah, other 824 * functions can play with it (like re-allocate and copy). 825 */ 826 mhist = ip6_addaux(m); 827 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 828 hist = mtod(mhist, caddr_t) + mhist->m_len; 829 bcopy(&nxt, hist, sizeof(nxt)); 830 mhist->m_len += sizeof(nxt); 831 } else { 832 ip6stat.ip6s_toomanyhdr++; 833 goto bad; 834 } 835 #endif 836 837 #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 ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 844 ipsec6_in_reject(m, NULL)) { 845 ipsec6stat.in_polvio++; 846 goto bad; 847 } 848 #endif 849 850 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 851 } 852 return; 853 bad: 854 m_freem(m); 855 } 856 857 /* 858 * set/grab in6_ifaddr correspond to IPv6 destination address. 859 * XXX backward compatibility wrapper 860 */ 861 static struct mbuf * 862 ip6_setdstifaddr(m, ia6) 863 struct mbuf *m; 864 struct in6_ifaddr *ia6; 865 { 866 struct mbuf *n; 867 868 n = ip6_addaux(m); 869 if (n) 870 mtod(n, struct ip6aux *)->ip6a_dstia6 = ia6; 871 return n; /* NULL if failed to set */ 872 } 873 874 struct in6_ifaddr * 875 ip6_getdstifaddr(m) 876 struct mbuf *m; 877 { 878 struct mbuf *n; 879 880 n = ip6_findaux(m); 881 if (n) 882 return mtod(n, struct ip6aux *)->ip6a_dstia6; 883 else 884 return NULL; 885 } 886 887 /* 888 * Hop-by-Hop options header processing. If a valid jumbo payload option is 889 * included, the real payload length will be stored in plenp. 890 */ 891 static int 892 ip6_hopopts_input(plenp, rtalertp, mp, offp) 893 u_int32_t *plenp; 894 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 895 struct mbuf **mp; 896 int *offp; 897 { 898 struct mbuf *m = *mp; 899 int off = *offp, hbhlen; 900 struct ip6_hbh *hbh; 901 u_int8_t *opt; 902 903 /* validation of the length of the header */ 904 #ifndef PULLDOWN_TEST 905 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 906 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 907 hbhlen = (hbh->ip6h_len + 1) << 3; 908 909 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 910 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 911 #else 912 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 913 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 914 if (hbh == NULL) { 915 ip6stat.ip6s_tooshort++; 916 return -1; 917 } 918 hbhlen = (hbh->ip6h_len + 1) << 3; 919 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 920 hbhlen); 921 if (hbh == NULL) { 922 ip6stat.ip6s_tooshort++; 923 return -1; 924 } 925 #endif 926 off += hbhlen; 927 hbhlen -= sizeof(struct ip6_hbh); 928 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 929 930 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 931 hbhlen, rtalertp, plenp) < 0) 932 return(-1); 933 934 *offp = off; 935 *mp = m; 936 return(0); 937 } 938 939 /* 940 * Search header for all Hop-by-hop options and process each option. 941 * This function is separate from ip6_hopopts_input() in order to 942 * handle a case where the sending node itself process its hop-by-hop 943 * options header. In such a case, the function is called from ip6_output(). 944 * 945 * The function assumes that hbh header is located right after the IPv6 header 946 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 947 * opthead + hbhlen is located in continuous memory region. 948 */ 949 int 950 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 951 struct mbuf *m; 952 u_int8_t *opthead; 953 int hbhlen; 954 u_int32_t *rtalertp; 955 u_int32_t *plenp; 956 { 957 struct ip6_hdr *ip6; 958 int optlen = 0; 959 u_int8_t *opt = opthead; 960 u_int16_t rtalert_val; 961 u_int32_t jumboplen; 962 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 963 964 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 965 switch (*opt) { 966 case IP6OPT_PAD1: 967 optlen = 1; 968 break; 969 case IP6OPT_PADN: 970 if (hbhlen < IP6OPT_MINLEN) { 971 ip6stat.ip6s_toosmall++; 972 goto bad; 973 } 974 optlen = *(opt + 1) + 2; 975 break; 976 case IP6OPT_RTALERT: 977 /* XXX may need check for alignment */ 978 if (hbhlen < IP6OPT_RTALERT_LEN) { 979 ip6stat.ip6s_toosmall++; 980 goto bad; 981 } 982 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 983 /* XXX stat */ 984 icmp6_error(m, ICMP6_PARAM_PROB, 985 ICMP6_PARAMPROB_HEADER, 986 erroff + opt + 1 - opthead); 987 return(-1); 988 } 989 optlen = IP6OPT_RTALERT_LEN; 990 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 991 *rtalertp = ntohs(rtalert_val); 992 break; 993 case IP6OPT_JUMBO: 994 /* XXX may need check for alignment */ 995 if (hbhlen < IP6OPT_JUMBO_LEN) { 996 ip6stat.ip6s_toosmall++; 997 goto bad; 998 } 999 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1000 /* XXX stat */ 1001 icmp6_error(m, ICMP6_PARAM_PROB, 1002 ICMP6_PARAMPROB_HEADER, 1003 erroff + opt + 1 - opthead); 1004 return(-1); 1005 } 1006 optlen = IP6OPT_JUMBO_LEN; 1007 1008 /* 1009 * IPv6 packets that have non 0 payload length 1010 * must not contain a jumbo payload option. 1011 */ 1012 ip6 = mtod(m, struct ip6_hdr *); 1013 if (ip6->ip6_plen) { 1014 ip6stat.ip6s_badoptions++; 1015 icmp6_error(m, ICMP6_PARAM_PROB, 1016 ICMP6_PARAMPROB_HEADER, 1017 erroff + opt - opthead); 1018 return(-1); 1019 } 1020 1021 /* 1022 * We may see jumbolen in unaligned location, so 1023 * we'd need to perform bcopy(). 1024 */ 1025 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1026 jumboplen = (u_int32_t)htonl(jumboplen); 1027 1028 #if 1 1029 /* 1030 * if there are multiple jumbo payload options, 1031 * *plenp will be non-zero and the packet will be 1032 * rejected. 1033 * the behavior may need some debate in ipngwg - 1034 * multiple options does not make sense, however, 1035 * there's no explicit mention in specification. 1036 */ 1037 if (*plenp != 0) { 1038 ip6stat.ip6s_badoptions++; 1039 icmp6_error(m, ICMP6_PARAM_PROB, 1040 ICMP6_PARAMPROB_HEADER, 1041 erroff + opt + 2 - opthead); 1042 return(-1); 1043 } 1044 #endif 1045 1046 /* 1047 * jumbo payload length must be larger than 65535. 1048 */ 1049 if (jumboplen <= IPV6_MAXPACKET) { 1050 ip6stat.ip6s_badoptions++; 1051 icmp6_error(m, ICMP6_PARAM_PROB, 1052 ICMP6_PARAMPROB_HEADER, 1053 erroff + opt + 2 - opthead); 1054 return(-1); 1055 } 1056 *plenp = jumboplen; 1057 1058 break; 1059 default: /* unknown option */ 1060 if (hbhlen < IP6OPT_MINLEN) { 1061 ip6stat.ip6s_toosmall++; 1062 goto bad; 1063 } 1064 optlen = ip6_unknown_opt(opt, m, 1065 erroff + opt - opthead); 1066 if (optlen == -1) 1067 return(-1); 1068 optlen += 2; 1069 break; 1070 } 1071 } 1072 1073 return(0); 1074 1075 bad: 1076 m_freem(m); 1077 return(-1); 1078 } 1079 1080 /* 1081 * Unknown option processing. 1082 * The third argument `off' is the offset from the IPv6 header to the option, 1083 * which is necessary if the IPv6 header the and option header and IPv6 header 1084 * is not continuous in order to return an ICMPv6 error. 1085 */ 1086 int 1087 ip6_unknown_opt(optp, m, off) 1088 u_int8_t *optp; 1089 struct mbuf *m; 1090 int off; 1091 { 1092 struct ip6_hdr *ip6; 1093 1094 switch (IP6OPT_TYPE(*optp)) { 1095 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1096 return((int)*(optp + 1)); 1097 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1098 m_freem(m); 1099 return(-1); 1100 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1101 ip6stat.ip6s_badoptions++; 1102 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1103 return(-1); 1104 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1105 ip6stat.ip6s_badoptions++; 1106 ip6 = mtod(m, struct ip6_hdr *); 1107 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1108 (m->m_flags & (M_BCAST|M_MCAST))) 1109 m_freem(m); 1110 else 1111 icmp6_error(m, ICMP6_PARAM_PROB, 1112 ICMP6_PARAMPROB_OPTION, off); 1113 return(-1); 1114 } 1115 1116 m_freem(m); /* XXX: NOTREACHED */ 1117 return(-1); 1118 } 1119 1120 /* 1121 * Create the "control" list for this pcb. 1122 * The function will not modify mbuf chain at all. 1123 * 1124 * with KAME mbuf chain restriction: 1125 * The routine will be called from upper layer handlers like tcp6_input(). 1126 * Thus the routine assumes that the caller (tcp6_input) have already 1127 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1128 * very first mbuf on the mbuf chain. 1129 */ 1130 void 1131 ip6_savecontrol(in6p, mp, ip6, m) 1132 struct inpcb *in6p; 1133 struct mbuf **mp; 1134 struct ip6_hdr *ip6; 1135 struct mbuf *m; 1136 { 1137 #if __FreeBSD__ >= 5 1138 struct thread *td = curthread; /* XXX */ 1139 #else 1140 struct proc *td = curproc; /* XXX */ 1141 #endif 1142 int privileged = 0; 1143 int rthdr_exist = 0; 1144 1145 1146 if (td && !suser(td)) 1147 privileged++; 1148 1149 #ifdef SO_TIMESTAMP 1150 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1151 struct timeval tv; 1152 1153 microtime(&tv); 1154 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1155 SCM_TIMESTAMP, SOL_SOCKET); 1156 if (*mp) { 1157 mp = &(*mp)->m_next; 1158 } 1159 } 1160 #endif 1161 1162 /* RFC 2292 sec. 5 */ 1163 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1164 struct in6_pktinfo pi6; 1165 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1166 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1167 pi6.ipi6_addr.s6_addr16[1] = 0; 1168 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1169 ? m->m_pkthdr.rcvif->if_index 1170 : 0; 1171 *mp = sbcreatecontrol((caddr_t) &pi6, 1172 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1173 IPPROTO_IPV6); 1174 if (*mp) 1175 mp = &(*mp)->m_next; 1176 } 1177 1178 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1179 int hlim = ip6->ip6_hlim & 0xff; 1180 *mp = sbcreatecontrol((caddr_t) &hlim, 1181 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1182 if (*mp) 1183 mp = &(*mp)->m_next; 1184 } 1185 1186 /* 1187 * IPV6_HOPOPTS socket option. We require super-user privilege 1188 * for the option, but it might be too strict, since there might 1189 * be some hop-by-hop options which can be returned to normal user. 1190 * See RFC 2292 section 6. 1191 */ 1192 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { 1193 /* 1194 * Check if a hop-by-hop options header is contatined in the 1195 * received packet, and if so, store the options as ancillary 1196 * data. Note that a hop-by-hop options header must be 1197 * just after the IPv6 header, which fact is assured through 1198 * the IPv6 input processing. 1199 */ 1200 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1201 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1202 struct ip6_hbh *hbh; 1203 int hbhlen = 0; 1204 #ifdef PULLDOWN_TEST 1205 struct mbuf *ext; 1206 #endif 1207 1208 #ifndef PULLDOWN_TEST 1209 hbh = (struct ip6_hbh *)(ip6 + 1); 1210 hbhlen = (hbh->ip6h_len + 1) << 3; 1211 #else 1212 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1213 ip6->ip6_nxt); 1214 if (ext == NULL) { 1215 ip6stat.ip6s_tooshort++; 1216 return; 1217 } 1218 hbh = mtod(ext, struct ip6_hbh *); 1219 hbhlen = (hbh->ip6h_len + 1) << 3; 1220 if (hbhlen != ext->m_len) { 1221 m_freem(ext); 1222 ip6stat.ip6s_tooshort++; 1223 return; 1224 } 1225 #endif 1226 1227 /* 1228 * XXX: We copy whole the header even if a jumbo 1229 * payload option is included, which option is to 1230 * be removed before returning in the RFC 2292. 1231 * Note: this constraint is removed in 2292bis. 1232 */ 1233 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1234 IPV6_HOPOPTS, IPPROTO_IPV6); 1235 if (*mp) 1236 mp = &(*mp)->m_next; 1237 #ifdef PULLDOWN_TEST 1238 m_freem(ext); 1239 #endif 1240 } 1241 } 1242 1243 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1244 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1245 int proto, off, nxt; 1246 1247 /* 1248 * go through the header chain to see if a routing header is 1249 * contained in the packet. We need this information to store 1250 * destination options headers (if any) properly. 1251 * XXX: performance issue. We should record this info when 1252 * processing extension headers in incoming routine. 1253 * (todo) use m_aux? 1254 */ 1255 proto = IPPROTO_IPV6; 1256 off = 0; 1257 nxt = -1; 1258 while (1) { 1259 int newoff; 1260 1261 newoff = ip6_nexthdr(m, off, proto, &nxt); 1262 if (newoff < 0) 1263 break; 1264 if (newoff < off) /* invalid, check for safety */ 1265 break; 1266 if ((proto = nxt) == IPPROTO_ROUTING) { 1267 rthdr_exist = 1; 1268 break; 1269 } 1270 off = newoff; 1271 } 1272 } 1273 1274 if ((in6p->in6p_flags & 1275 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1276 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1277 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1278 1279 /* 1280 * Search for destination options headers or routing 1281 * header(s) through the header chain, and stores each 1282 * header as ancillary data. 1283 * Note that the order of the headers remains in 1284 * the chain of ancillary data. 1285 */ 1286 while (1) { /* is explicit loop prevention necessary? */ 1287 struct ip6_ext *ip6e = NULL; 1288 int elen; 1289 #ifdef PULLDOWN_TEST 1290 struct mbuf *ext = NULL; 1291 #endif 1292 1293 /* 1294 * if it is not an extension header, don't try to 1295 * pull it from the chain. 1296 */ 1297 switch (nxt) { 1298 case IPPROTO_DSTOPTS: 1299 case IPPROTO_ROUTING: 1300 case IPPROTO_HOPOPTS: 1301 case IPPROTO_AH: /* is it possible? */ 1302 break; 1303 default: 1304 goto loopend; 1305 } 1306 1307 #ifndef PULLDOWN_TEST 1308 if (off + sizeof(*ip6e) > m->m_len) 1309 goto loopend; 1310 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1311 if (nxt == IPPROTO_AH) 1312 elen = (ip6e->ip6e_len + 2) << 2; 1313 else 1314 elen = (ip6e->ip6e_len + 1) << 3; 1315 if (off + elen > m->m_len) 1316 goto loopend; 1317 #else 1318 ext = ip6_pullexthdr(m, off, nxt); 1319 if (ext == NULL) { 1320 ip6stat.ip6s_tooshort++; 1321 return; 1322 } 1323 ip6e = mtod(ext, struct ip6_ext *); 1324 if (nxt == IPPROTO_AH) 1325 elen = (ip6e->ip6e_len + 2) << 2; 1326 else 1327 elen = (ip6e->ip6e_len + 1) << 3; 1328 if (elen != ext->m_len) { 1329 m_freem(ext); 1330 ip6stat.ip6s_tooshort++; 1331 return; 1332 } 1333 #endif 1334 1335 switch (nxt) { 1336 case IPPROTO_DSTOPTS: 1337 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1338 break; 1339 1340 /* 1341 * We also require super-user privilege for 1342 * the option. 1343 * See the comments on IN6_HOPOPTS. 1344 */ 1345 if (!privileged) 1346 break; 1347 1348 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1349 IPV6_DSTOPTS, 1350 IPPROTO_IPV6); 1351 if (*mp) 1352 mp = &(*mp)->m_next; 1353 break; 1354 case IPPROTO_ROUTING: 1355 if (!in6p->in6p_flags & IN6P_RTHDR) 1356 break; 1357 1358 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1359 IPV6_RTHDR, 1360 IPPROTO_IPV6); 1361 if (*mp) 1362 mp = &(*mp)->m_next; 1363 break; 1364 case IPPROTO_HOPOPTS: 1365 case IPPROTO_AH: /* is it possible? */ 1366 break; 1367 1368 default: 1369 /* 1370 * other cases have been filtered in the above. 1371 * none will visit this case. here we supply 1372 * the code just in case (nxt overwritten or 1373 * other cases). 1374 */ 1375 #ifdef PULLDOWN_TEST 1376 m_freem(ext); 1377 #endif 1378 goto loopend; 1379 1380 } 1381 1382 /* proceed with the next header. */ 1383 off += elen; 1384 nxt = ip6e->ip6e_nxt; 1385 ip6e = NULL; 1386 #ifdef PULLDOWN_TEST 1387 m_freem(ext); 1388 ext = NULL; 1389 #endif 1390 } 1391 loopend: 1392 ; 1393 } 1394 1395 } 1396 1397 #ifdef PULLDOWN_TEST 1398 /* 1399 * pull single extension header from mbuf chain. returns single mbuf that 1400 * contains the result, or NULL on error. 1401 */ 1402 static struct mbuf * 1403 ip6_pullexthdr(m, off, nxt) 1404 struct mbuf *m; 1405 size_t off; 1406 int nxt; 1407 { 1408 struct ip6_ext ip6e; 1409 size_t elen; 1410 struct mbuf *n; 1411 1412 #ifdef DIAGNOSTIC 1413 switch (nxt) { 1414 case IPPROTO_DSTOPTS: 1415 case IPPROTO_ROUTING: 1416 case IPPROTO_HOPOPTS: 1417 case IPPROTO_AH: /* is it possible? */ 1418 break; 1419 default: 1420 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1421 } 1422 #endif 1423 1424 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1425 if (nxt == IPPROTO_AH) 1426 elen = (ip6e.ip6e_len + 2) << 2; 1427 else 1428 elen = (ip6e.ip6e_len + 1) << 3; 1429 1430 MGET(n, M_DONTWAIT, MT_DATA); 1431 if (n && elen >= MLEN) { 1432 MCLGET(n, M_DONTWAIT); 1433 if ((n->m_flags & M_EXT) == 0) { 1434 m_free(n); 1435 n = NULL; 1436 } 1437 } 1438 if (!n) 1439 return NULL; 1440 1441 n->m_len = 0; 1442 if (elen >= M_TRAILINGSPACE(n)) { 1443 m_free(n); 1444 return NULL; 1445 } 1446 1447 m_copydata(m, off, elen, mtod(n, caddr_t)); 1448 n->m_len = elen; 1449 return n; 1450 } 1451 #endif 1452 1453 /* 1454 * Get pointer to the previous header followed by the header 1455 * currently processed. 1456 * XXX: This function supposes that 1457 * M includes all headers, 1458 * the next header field and the header length field of each header 1459 * are valid, and 1460 * the sum of each header length equals to OFF. 1461 * Because of these assumptions, this function must be called very 1462 * carefully. Moreover, it will not be used in the near future when 1463 * we develop `neater' mechanism to process extension headers. 1464 */ 1465 char * 1466 ip6_get_prevhdr(m, off) 1467 struct mbuf *m; 1468 int off; 1469 { 1470 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1471 1472 if (off == sizeof(struct ip6_hdr)) 1473 return(&ip6->ip6_nxt); 1474 else { 1475 int len, nxt; 1476 struct ip6_ext *ip6e = NULL; 1477 1478 nxt = ip6->ip6_nxt; 1479 len = sizeof(struct ip6_hdr); 1480 while (len < off) { 1481 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1482 1483 switch (nxt) { 1484 case IPPROTO_FRAGMENT: 1485 len += sizeof(struct ip6_frag); 1486 break; 1487 case IPPROTO_AH: 1488 len += (ip6e->ip6e_len + 2) << 2; 1489 break; 1490 default: 1491 len += (ip6e->ip6e_len + 1) << 3; 1492 break; 1493 } 1494 nxt = ip6e->ip6e_nxt; 1495 } 1496 if (ip6e) 1497 return(&ip6e->ip6e_nxt); 1498 else 1499 return NULL; 1500 } 1501 } 1502 1503 /* 1504 * get next header offset. m will be retained. 1505 */ 1506 int 1507 ip6_nexthdr(m, off, proto, nxtp) 1508 struct mbuf *m; 1509 int off; 1510 int proto; 1511 int *nxtp; 1512 { 1513 struct ip6_hdr ip6; 1514 struct ip6_ext ip6e; 1515 struct ip6_frag fh; 1516 1517 /* just in case */ 1518 if (m == NULL) 1519 panic("ip6_nexthdr: m == NULL"); 1520 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1521 return -1; 1522 1523 switch (proto) { 1524 case IPPROTO_IPV6: 1525 if (m->m_pkthdr.len < off + sizeof(ip6)) 1526 return -1; 1527 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1528 if (nxtp) 1529 *nxtp = ip6.ip6_nxt; 1530 off += sizeof(ip6); 1531 return off; 1532 1533 case IPPROTO_FRAGMENT: 1534 /* 1535 * terminate parsing if it is not the first fragment, 1536 * it does not make sense to parse through it. 1537 */ 1538 if (m->m_pkthdr.len < off + sizeof(fh)) 1539 return -1; 1540 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1541 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1542 return -1; 1543 if (nxtp) 1544 *nxtp = fh.ip6f_nxt; 1545 off += sizeof(struct ip6_frag); 1546 return off; 1547 1548 case IPPROTO_AH: 1549 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1550 return -1; 1551 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1552 if (nxtp) 1553 *nxtp = ip6e.ip6e_nxt; 1554 off += (ip6e.ip6e_len + 2) << 2; 1555 return off; 1556 1557 case IPPROTO_HOPOPTS: 1558 case IPPROTO_ROUTING: 1559 case IPPROTO_DSTOPTS: 1560 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1561 return -1; 1562 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1563 if (nxtp) 1564 *nxtp = ip6e.ip6e_nxt; 1565 off += (ip6e.ip6e_len + 1) << 3; 1566 return off; 1567 1568 case IPPROTO_NONE: 1569 case IPPROTO_ESP: 1570 case IPPROTO_IPCOMP: 1571 /* give up */ 1572 return -1; 1573 1574 default: 1575 return -1; 1576 } 1577 1578 return -1; 1579 } 1580 1581 /* 1582 * get offset for the last header in the chain. m will be kept untainted. 1583 */ 1584 int 1585 ip6_lasthdr(m, off, proto, nxtp) 1586 struct mbuf *m; 1587 int off; 1588 int proto; 1589 int *nxtp; 1590 { 1591 int newoff; 1592 int nxt; 1593 1594 if (!nxtp) { 1595 nxt = -1; 1596 nxtp = &nxt; 1597 } 1598 while (1) { 1599 newoff = ip6_nexthdr(m, off, proto, nxtp); 1600 if (newoff < 0) 1601 return off; 1602 else if (newoff < off) 1603 return -1; /* invalid */ 1604 else if (newoff == off) 1605 return newoff; 1606 1607 off = newoff; 1608 proto = *nxtp; 1609 } 1610 } 1611 1612 struct mbuf * 1613 ip6_addaux(m) 1614 struct mbuf *m; 1615 { 1616 struct mbuf *n; 1617 1618 #ifdef DIAGNOSTIC 1619 if (sizeof(struct ip6aux) > MHLEN) 1620 panic("assumption failed on sizeof(ip6aux)"); 1621 #endif 1622 n = m_aux_find(m, AF_INET6, -1); 1623 if (n) { 1624 if (n->m_len < sizeof(struct ip6aux)) { 1625 printf("conflicting use of ip6aux"); 1626 return NULL; 1627 } 1628 } else { 1629 n = m_aux_add(m, AF_INET6, -1); 1630 n->m_len = sizeof(struct ip6aux); 1631 bzero(mtod(n, caddr_t), n->m_len); 1632 } 1633 return n; 1634 } 1635 1636 struct mbuf * 1637 ip6_findaux(m) 1638 struct mbuf *m; 1639 { 1640 struct mbuf *n; 1641 1642 n = m_aux_find(m, AF_INET6, -1); 1643 if (n && n->m_len < sizeof(struct ip6aux)) { 1644 printf("conflicting use of ip6aux"); 1645 n = NULL; 1646 } 1647 return n; 1648 } 1649 1650 void 1651 ip6_delaux(m) 1652 struct mbuf *m; 1653 { 1654 struct mbuf *n; 1655 1656 n = m_aux_find(m, AF_INET6, -1); 1657 if (n) 1658 m_aux_delete(m, n); 1659 } 1660 1661 /* 1662 * System control for IP6 1663 */ 1664 1665 u_char inet6ctlerrmap[PRC_NCMDS] = { 1666 0, 0, 0, 0, 1667 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1668 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1669 EMSGSIZE, EHOSTUNREACH, 0, 0, 1670 0, 0, 0, 0, 1671 ENOPROTOOPT 1672 }; 1673