1 /* $FreeBSD$ */ 2 /* $KAME: ip6_input.c,v 1.194 2001/05/27 13:28:35 itojun 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/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 87 #include <net/if.h> 88 #include <net/if_types.h> 89 #include <net/if_dl.h> 90 #include <net/route.h> 91 #include <net/netisr.h> 92 #include <net/intrq.h> 93 #ifdef PFIL_HOOKS 94 #include <net/pfil.h> 95 #endif 96 97 #include <netinet/in.h> 98 #include <netinet/in_systm.h> 99 #ifdef INET 100 #include <netinet/ip.h> 101 #include <netinet/ip_icmp.h> 102 #endif /*INET*/ 103 #include <netinet/ip6.h> 104 #include <netinet6/in6_var.h> 105 #include <netinet6/ip6_var.h> 106 #include <netinet/in_pcb.h> 107 #include <netinet/icmp6.h> 108 #include <netinet6/in6_ifattach.h> 109 #include <netinet6/nd6.h> 110 #include <netinet6/in6_prefix.h> 111 112 #ifdef IPSEC 113 #include <netinet6/ipsec.h> 114 #ifdef INET6 115 #include <netinet6/ipsec6.h> 116 #endif 117 #endif 118 119 #include <netinet6/ip6_fw.h> 120 121 #include <netinet6/ip6protosw.h> 122 123 #include "faith.h" 124 125 #include <net/net_osdep.h> 126 127 extern struct domain inet6domain; 128 extern struct ip6protosw inet6sw[]; 129 130 u_char ip6_protox[IPPROTO_MAX]; 131 static int ip6qmaxlen = IFQ_MAXLEN; 132 struct in6_ifaddr *in6_ifaddr; 133 134 extern struct callout in6_tmpaddrtimer_ch; 135 136 int ip6_forward_srcrt; /* XXX */ 137 int ip6_sourcecheck; /* XXX */ 138 int ip6_sourcecheck_interval; /* XXX */ 139 const int int6intrq_present = 1; 140 141 int ip6_ours_check_algorithm; 142 143 144 /* firewall hooks */ 145 ip6_fw_chk_t *ip6_fw_chk_ptr; 146 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 147 int ip6_fw_enable = 1; 148 149 struct ip6stat ip6stat; 150 151 static void ip6_init2 __P((void *)); 152 static struct mbuf *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 153 154 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 155 #ifdef PULLDOWN_TEST 156 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 157 #endif 158 159 160 /* 161 * IP6 initialization: fill in IP6 protocol switch table. 162 * All protocols not implemented in kernel go to raw IP6 protocol handler. 163 */ 164 void 165 ip6_init() 166 { 167 struct ip6protosw *pr; 168 int i; 169 struct timeval tv; 170 171 #ifdef DIAGNOSTIC 172 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 173 panic("sizeof(protosw) != sizeof(ip6protosw)"); 174 #endif 175 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 176 if (pr == 0) 177 panic("ip6_init"); 178 for (i = 0; i < IPPROTO_MAX; i++) 179 ip6_protox[i] = pr - inet6sw; 180 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 181 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 182 if (pr->pr_domain->dom_family == PF_INET6 && 183 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 184 ip6_protox[pr->pr_protocol] = pr - inet6sw; 185 ip6intrq.ifq_maxlen = ip6qmaxlen; 186 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", MTX_DEF); 187 register_netisr(NETISR_IPV6, ip6intr); 188 nd6_init(); 189 frag6_init(); 190 /* 191 * in many cases, random() here does NOT return random number 192 * as initialization during bootstrap time occur in fixed order. 193 */ 194 microtime(&tv); 195 ip6_flow_seq = random() ^ tv.tv_usec; 196 microtime(&tv); 197 ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 198 } 199 200 static void 201 ip6_init2(dummy) 202 void *dummy; 203 { 204 205 /* 206 * to route local address of p2p link to loopback, 207 * assign loopback address first. 208 */ 209 in6_ifattach(&loif[0], NULL); 210 211 /* nd6_timer_init */ 212 callout_init(&nd6_timer_ch, 0); 213 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 214 215 /* router renumbering prefix list maintenance */ 216 callout_init(&in6_rr_timer_ch, 0); 217 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 218 219 /* timer for regeneranation of temporary addresses randomize ID */ 220 callout_reset(&in6_tmpaddrtimer_ch, 221 (ip6_temp_preferred_lifetime - ip6_desync_factor - 222 ip6_temp_regen_advance) * hz, 223 in6_tmpaddrtimer, NULL); 224 } 225 226 /* cheat */ 227 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 228 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 229 230 /* 231 * IP6 input interrupt handling. Just pass the packet to ip6_input. 232 */ 233 void 234 ip6intr() 235 { 236 int s; 237 struct mbuf *m; 238 239 for (;;) { 240 s = splimp(); 241 IF_DEQUEUE(&ip6intrq, m); 242 splx(s); 243 if (m == 0) 244 return; 245 ip6_input(m); 246 } 247 } 248 249 extern struct route_in6 ip6_forward_rt; 250 251 void 252 ip6_input(m) 253 struct mbuf *m; 254 { 255 struct ip6_hdr *ip6; 256 int off = sizeof(struct ip6_hdr), nest; 257 u_int32_t plen; 258 u_int32_t rtalert = ~0; 259 int nxt, ours = 0; 260 struct ifnet *deliverifp = NULL; 261 #ifdef PFIL_HOOKS 262 struct packet_filter_hook *pfh; 263 struct mbuf *m0; 264 int rv; 265 #endif /* PFIL_HOOKS */ 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 by kazu 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_COPY_PKTHDR(n, m); 320 if (n && m->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) { 328 m_freem(m); 329 return; /*ENOBUFS*/ 330 } 331 332 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 333 n->m_len = m->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 #ifdef PFIL_HOOKS 359 /* 360 * Run through list of hooks for input packets. If there are any 361 * filters which require that additional packets in the flow are 362 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 363 * Note that filters must _never_ set this flag, as another filter 364 * in the list may have previously cleared it. 365 */ 366 m0 = m; 367 pfh = pfil_hook_get(PFIL_IN, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); 368 for (; pfh; pfh = pfh->pfil_link.tqe_next) 369 if (pfh->pfil_func) { 370 rv = pfh->pfil_func(ip6, sizeof(*ip6), 371 m->m_pkthdr.rcvif, 0, &m0); 372 if (rv) 373 return; 374 m = m0; 375 if (m == NULL) 376 return; 377 ip6 = mtod(m, struct ip6_hdr *); 378 } 379 #endif /* PFIL_HOOKS */ 380 381 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 382 383 /* 384 * Check with the firewall... 385 */ 386 if (ip6_fw_enable && ip6_fw_chk_ptr) { 387 u_short port = 0; 388 /* If ipfw says divert, we have to just drop packet */ 389 /* use port as a dummy argument */ 390 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 391 m_freem(m); 392 m = NULL; 393 } 394 if (!m) 395 return; 396 } 397 398 /* 399 * Check against address spoofing/corruption. 400 */ 401 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 402 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 403 /* 404 * XXX: "badscope" is not very suitable for a multicast source. 405 */ 406 ip6stat.ip6s_badscope++; 407 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 408 goto bad; 409 } 410 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 411 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 412 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 413 ip6stat.ip6s_badscope++; 414 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 415 goto bad; 416 } 417 /* 418 * The following check is not documented in specs. A malicious 419 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 420 * and bypass security checks (act as if it was from 127.0.0.1 by using 421 * IPv6 src ::ffff:127.0.0.1). Be cautious. 422 * 423 * This check chokes if we are in an SIIT cloud. As none of BSDs 424 * support IPv4-less kernel compilation, we cannot support SIIT 425 * environment at all. So, it makes more sense for us to reject any 426 * malicious packets for non-SIIT environment, than try to do a 427 * partical support for SIIT environment. 428 */ 429 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 430 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 431 ip6stat.ip6s_badscope++; 432 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 433 goto bad; 434 } 435 #if 0 436 /* 437 * Reject packets with IPv4 compatible addresses (auto tunnel). 438 * 439 * The code forbids auto tunnel relay case in RFC1933 (the check is 440 * stronger than RFC1933). We may want to re-enable it if mech-xx 441 * is revised to forbid relaying case. 442 */ 443 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 444 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 445 ip6stat.ip6s_badscope++; 446 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 447 goto bad; 448 } 449 #endif 450 451 /* drop packets if interface ID portion is already filled */ 452 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 453 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 454 ip6->ip6_src.s6_addr16[1]) { 455 ip6stat.ip6s_badscope++; 456 goto bad; 457 } 458 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 459 ip6->ip6_dst.s6_addr16[1]) { 460 ip6stat.ip6s_badscope++; 461 goto bad; 462 } 463 } 464 465 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 466 ip6->ip6_src.s6_addr16[1] 467 = htons(m->m_pkthdr.rcvif->if_index); 468 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 469 ip6->ip6_dst.s6_addr16[1] 470 = htons(m->m_pkthdr.rcvif->if_index); 471 472 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 473 /* 474 * We use rt->rt_ifp to determine if the address is ours or not. 475 * If rt_ifp is lo0, the address is ours. 476 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 477 * so any address under fe80::%lo0/64 will be mistakenly considered 478 * local. The special case is supplied to handle the case properly 479 * by actually looking at interface addresses 480 * (using in6ifa_ifpwithaddr). 481 */ 482 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 483 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 484 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 485 icmp6_error(m, ICMP6_DST_UNREACH, 486 ICMP6_DST_UNREACH_ADDR, 0); 487 /* m is already freed */ 488 return; 489 } 490 491 ours = 1; 492 deliverifp = m->m_pkthdr.rcvif; 493 goto hbhcheck; 494 } 495 #endif 496 497 /* 498 * Multicast check 499 */ 500 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 501 struct in6_multi *in6m = 0; 502 503 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 504 /* 505 * See if we belong to the destination multicast group on the 506 * arrival interface. 507 */ 508 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 509 if (in6m) 510 ours = 1; 511 else if (!ip6_mrouter) { 512 ip6stat.ip6s_notmember++; 513 ip6stat.ip6s_cantforward++; 514 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 515 goto bad; 516 } 517 deliverifp = m->m_pkthdr.rcvif; 518 goto hbhcheck; 519 } 520 521 /* 522 * Unicast check 523 */ 524 switch (ip6_ours_check_algorithm) { 525 default: 526 /* 527 * XXX: I intentionally broke our indentation rule here, 528 * since this switch-case is just for measurement and 529 * therefore should soon be removed. 530 */ 531 if (ip6_forward_rt.ro_rt != NULL && 532 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 533 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 534 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 535 ip6stat.ip6s_forward_cachehit++; 536 else { 537 struct sockaddr_in6 *dst6; 538 539 if (ip6_forward_rt.ro_rt) { 540 /* route is down or destination is different */ 541 ip6stat.ip6s_forward_cachemiss++; 542 RTFREE(ip6_forward_rt.ro_rt); 543 ip6_forward_rt.ro_rt = 0; 544 } 545 546 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 547 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 548 dst6->sin6_len = sizeof(struct sockaddr_in6); 549 dst6->sin6_family = AF_INET6; 550 dst6->sin6_addr = ip6->ip6_dst; 551 #ifdef SCOPEDROUTING 552 ip6_forward_rt.ro_dst.sin6_scope_id = 553 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 554 #endif 555 556 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 557 } 558 559 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 560 561 /* 562 * Accept the packet if the forwarding interface to the destination 563 * according to the routing table is the loopback interface, 564 * unless the associated route has a gateway. 565 * Note that this approach causes to accept a packet if there is a 566 * route to the loopback interface for the destination of the packet. 567 * But we think it's even useful in some situations, e.g. when using 568 * a special daemon which wants to intercept the packet. 569 * 570 * XXX: some OSes automatically make a cloned route for the destination 571 * of an outgoing packet. If the outgoing interface of the packet 572 * is a loopback one, the kernel would consider the packet to be 573 * accepted, even if we have no such address assinged on the interface. 574 * We check the cloned flag of the route entry to reject such cases, 575 * assuming that route entries for our own addresses are not made by 576 * cloning (it should be true because in6_addloop explicitly installs 577 * the host route). However, we might have to do an explicit check 578 * while it would be less efficient. Or, should we rather install a 579 * reject route for such a case? 580 */ 581 if (ip6_forward_rt.ro_rt && 582 (ip6_forward_rt.ro_rt->rt_flags & 583 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 584 #ifdef RTF_WASCLONED 585 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 586 #endif 587 #ifdef RTF_CLONED 588 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 589 #endif 590 #if 0 591 /* 592 * The check below is redundant since the comparison of 593 * the destination and the key of the rtentry has 594 * already done through looking up the routing table. 595 */ 596 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 597 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 598 #endif 599 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 600 struct in6_ifaddr *ia6 = 601 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 602 603 /* 604 * record address information into m_aux. 605 */ 606 (void)ip6_setdstifaddr(m, ia6); 607 608 /* 609 * packets to a tentative, duplicated, or somehow invalid 610 * address must not be accepted. 611 */ 612 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 613 /* this address is ready */ 614 ours = 1; 615 deliverifp = ia6->ia_ifp; /* correct? */ 616 /* Count the packet in the ip address stats */ 617 ia6->ia_ifa.if_ipackets++; 618 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 619 goto hbhcheck; 620 } else { 621 /* address is not ready, so discard the packet. */ 622 nd6log((LOG_INFO, 623 "ip6_input: packet to an unready address %s->%s\n", 624 ip6_sprintf(&ip6->ip6_src), 625 ip6_sprintf(&ip6->ip6_dst))); 626 627 goto bad; 628 } 629 } 630 } /* XXX indentation (see above) */ 631 632 /* 633 * FAITH(Firewall Aided Internet Translator) 634 */ 635 #if defined(NFAITH) && 0 < NFAITH 636 if (ip6_keepfaith) { 637 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 638 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 639 /* XXX do we need more sanity checks? */ 640 ours = 1; 641 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/ 642 goto hbhcheck; 643 } 644 } 645 #endif 646 647 /* 648 * Now there is no reason to process the packet if it's not our own 649 * and we're not a router. 650 */ 651 if (!ip6_forwarding) { 652 ip6stat.ip6s_cantforward++; 653 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 654 goto bad; 655 } 656 657 hbhcheck: 658 /* 659 * record address information into m_aux, if we don't have one yet. 660 * note that we are unable to record it, if the address is not listed 661 * as our interface address (e.g. multicast addresses, addresses 662 * within FAITH prefixes and such). 663 */ 664 if (deliverifp && !ip6_getdstifaddr(m)) { 665 struct in6_ifaddr *ia6; 666 667 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 668 if (ia6) { 669 if (!ip6_setdstifaddr(m, ia6)) { 670 /* 671 * XXX maybe we should drop the packet here, 672 * as we could not provide enough information 673 * to the upper layers. 674 */ 675 } 676 } 677 } 678 679 /* 680 * Process Hop-by-Hop options header if it's contained. 681 * m may be modified in ip6_hopopts_input(). 682 * If a JumboPayload option is included, plen will also be modified. 683 */ 684 plen = (u_int32_t)ntohs(ip6->ip6_plen); 685 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 686 struct ip6_hbh *hbh; 687 688 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 689 #if 0 /*touches NULL pointer*/ 690 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 691 #endif 692 return; /* m have already been freed */ 693 } 694 695 /* adjust pointer */ 696 ip6 = mtod(m, struct ip6_hdr *); 697 698 /* 699 * if the payload length field is 0 and the next header field 700 * indicates Hop-by-Hop Options header, then a Jumbo Payload 701 * option MUST be included. 702 */ 703 if (ip6->ip6_plen == 0 && plen == 0) { 704 /* 705 * Note that if a valid jumbo payload option is 706 * contained, ip6_hoptops_input() must set a valid 707 * (non-zero) payload length to the variable plen. 708 */ 709 ip6stat.ip6s_badoptions++; 710 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 711 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 712 icmp6_error(m, ICMP6_PARAM_PROB, 713 ICMP6_PARAMPROB_HEADER, 714 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 715 return; 716 } 717 #ifndef PULLDOWN_TEST 718 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 719 hbh = (struct ip6_hbh *)(ip6 + 1); 720 #else 721 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 722 sizeof(struct ip6_hbh)); 723 if (hbh == NULL) { 724 ip6stat.ip6s_tooshort++; 725 return; 726 } 727 #endif 728 nxt = hbh->ip6h_nxt; 729 730 /* 731 * accept the packet if a router alert option is included 732 * and we act as an IPv6 router. 733 */ 734 if (rtalert != ~0 && ip6_forwarding) 735 ours = 1; 736 } else 737 nxt = ip6->ip6_nxt; 738 739 /* 740 * Check that the amount of data in the buffers 741 * is as at least much as the IPv6 header would have us expect. 742 * Trim mbufs if longer than we expect. 743 * Drop packet if shorter than we expect. 744 */ 745 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 746 ip6stat.ip6s_tooshort++; 747 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 748 goto bad; 749 } 750 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 751 if (m->m_len == m->m_pkthdr.len) { 752 m->m_len = sizeof(struct ip6_hdr) + plen; 753 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 754 } else 755 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 756 } 757 758 /* 759 * Forward if desirable. 760 */ 761 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 762 /* 763 * If we are acting as a multicast router, all 764 * incoming multicast packets are passed to the 765 * kernel-level multicast forwarding function. 766 * The packet is returned (relatively) intact; if 767 * ip6_mforward() returns a non-zero value, the packet 768 * must be discarded, else it may be accepted below. 769 */ 770 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 771 ip6stat.ip6s_cantforward++; 772 m_freem(m); 773 return; 774 } 775 if (!ours) { 776 m_freem(m); 777 return; 778 } 779 } else if (!ours) { 780 ip6_forward(m, 0); 781 return; 782 } 783 784 ip6 = mtod(m, struct ip6_hdr *); 785 786 /* 787 * Malicious party may be able to use IPv4 mapped addr to confuse 788 * tcp/udp stack and bypass security checks (act as if it was from 789 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 790 * 791 * For SIIT end node behavior, you may want to disable the check. 792 * However, you will become vulnerable to attacks using IPv4 mapped 793 * source. 794 */ 795 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 796 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 797 ip6stat.ip6s_badscope++; 798 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 799 goto bad; 800 } 801 802 /* 803 * Tell launch routine the next header 804 */ 805 ip6stat.ip6s_delivered++; 806 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 807 nest = 0; 808 809 while (nxt != IPPROTO_DONE) { 810 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 811 ip6stat.ip6s_toomanyhdr++; 812 goto bad; 813 } 814 815 /* 816 * protection against faulty packet - there should be 817 * more sanity checks in header chain processing. 818 */ 819 if (m->m_pkthdr.len < off) { 820 ip6stat.ip6s_tooshort++; 821 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 822 goto bad; 823 } 824 825 #if 0 826 /* 827 * do we need to do it for every header? yeah, other 828 * functions can play with it (like re-allocate and copy). 829 */ 830 mhist = ip6_addaux(m); 831 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 832 hist = mtod(mhist, caddr_t) + mhist->m_len; 833 bcopy(&nxt, hist, sizeof(nxt)); 834 mhist->m_len += sizeof(nxt); 835 } else { 836 ip6stat.ip6s_toomanyhdr++; 837 goto bad; 838 } 839 #endif 840 841 #ifdef IPSEC 842 /* 843 * enforce IPsec policy checking if we are seeing last header. 844 * note that we do not visit this with protocols with pcb layer 845 * code - like udp/tcp/raw ip. 846 */ 847 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 848 ipsec6_in_reject(m, NULL)) { 849 ipsec6stat.in_polvio++; 850 goto bad; 851 } 852 #endif 853 854 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 855 } 856 return; 857 bad: 858 m_freem(m); 859 } 860 861 /* 862 * set/grab in6_ifaddr correspond to IPv6 destination address. 863 * XXX backward compatibility wrapper 864 */ 865 static struct mbuf * 866 ip6_setdstifaddr(m, ia6) 867 struct mbuf *m; 868 struct in6_ifaddr *ia6; 869 { 870 struct mbuf *n; 871 872 n = ip6_addaux(m); 873 if (n) 874 mtod(n, struct ip6aux *)->ip6a_dstia6 = ia6; 875 return n; /* NULL if failed to set */ 876 } 877 878 struct in6_ifaddr * 879 ip6_getdstifaddr(m) 880 struct mbuf *m; 881 { 882 struct mbuf *n; 883 884 n = ip6_findaux(m); 885 if (n) 886 return mtod(n, struct ip6aux *)->ip6a_dstia6; 887 else 888 return NULL; 889 } 890 891 /* 892 * Hop-by-Hop options header processing. If a valid jumbo payload option is 893 * included, the real payload length will be stored in plenp. 894 */ 895 static int 896 ip6_hopopts_input(plenp, rtalertp, mp, offp) 897 u_int32_t *plenp; 898 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 899 struct mbuf **mp; 900 int *offp; 901 { 902 struct mbuf *m = *mp; 903 int off = *offp, hbhlen; 904 struct ip6_hbh *hbh; 905 u_int8_t *opt; 906 907 /* validation of the length of the header */ 908 #ifndef PULLDOWN_TEST 909 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 910 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 911 hbhlen = (hbh->ip6h_len + 1) << 3; 912 913 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 914 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 915 #else 916 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 917 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 918 if (hbh == NULL) { 919 ip6stat.ip6s_tooshort++; 920 return -1; 921 } 922 hbhlen = (hbh->ip6h_len + 1) << 3; 923 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 924 hbhlen); 925 if (hbh == NULL) { 926 ip6stat.ip6s_tooshort++; 927 return -1; 928 } 929 #endif 930 off += hbhlen; 931 hbhlen -= sizeof(struct ip6_hbh); 932 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 933 934 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 935 hbhlen, rtalertp, plenp) < 0) 936 return(-1); 937 938 *offp = off; 939 *mp = m; 940 return(0); 941 } 942 943 /* 944 * Search header for all Hop-by-hop options and process each option. 945 * This function is separate from ip6_hopopts_input() in order to 946 * handle a case where the sending node itself process its hop-by-hop 947 * options header. In such a case, the function is called from ip6_output(). 948 * 949 * The function assumes that hbh header is located right after the IPv6 header 950 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 951 * opthead + hbhlen is located in continuous memory region. 952 */ 953 int 954 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 955 struct mbuf *m; 956 u_int8_t *opthead; 957 int hbhlen; 958 u_int32_t *rtalertp; 959 u_int32_t *plenp; 960 { 961 struct ip6_hdr *ip6; 962 int optlen = 0; 963 u_int8_t *opt = opthead; 964 u_int16_t rtalert_val; 965 u_int32_t jumboplen; 966 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 967 968 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 969 switch (*opt) { 970 case IP6OPT_PAD1: 971 optlen = 1; 972 break; 973 case IP6OPT_PADN: 974 if (hbhlen < IP6OPT_MINLEN) { 975 ip6stat.ip6s_toosmall++; 976 goto bad; 977 } 978 optlen = *(opt + 1) + 2; 979 break; 980 case IP6OPT_RTALERT: 981 /* XXX may need check for alignment */ 982 if (hbhlen < IP6OPT_RTALERT_LEN) { 983 ip6stat.ip6s_toosmall++; 984 goto bad; 985 } 986 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 987 /* XXX stat */ 988 icmp6_error(m, ICMP6_PARAM_PROB, 989 ICMP6_PARAMPROB_HEADER, 990 erroff + opt + 1 - opthead); 991 return(-1); 992 } 993 optlen = IP6OPT_RTALERT_LEN; 994 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 995 *rtalertp = ntohs(rtalert_val); 996 break; 997 case IP6OPT_JUMBO: 998 /* XXX may need check for alignment */ 999 if (hbhlen < IP6OPT_JUMBO_LEN) { 1000 ip6stat.ip6s_toosmall++; 1001 goto bad; 1002 } 1003 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1004 /* XXX stat */ 1005 icmp6_error(m, ICMP6_PARAM_PROB, 1006 ICMP6_PARAMPROB_HEADER, 1007 erroff + opt + 1 - opthead); 1008 return(-1); 1009 } 1010 optlen = IP6OPT_JUMBO_LEN; 1011 1012 /* 1013 * IPv6 packets that have non 0 payload length 1014 * must not contain a jumbo payload option. 1015 */ 1016 ip6 = mtod(m, struct ip6_hdr *); 1017 if (ip6->ip6_plen) { 1018 ip6stat.ip6s_badoptions++; 1019 icmp6_error(m, ICMP6_PARAM_PROB, 1020 ICMP6_PARAMPROB_HEADER, 1021 erroff + opt - opthead); 1022 return(-1); 1023 } 1024 1025 /* 1026 * We may see jumbolen in unaligned location, so 1027 * we'd need to perform bcopy(). 1028 */ 1029 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1030 jumboplen = (u_int32_t)htonl(jumboplen); 1031 1032 #if 1 1033 /* 1034 * if there are multiple jumbo payload options, 1035 * *plenp will be non-zero and the packet will be 1036 * rejected. 1037 * the behavior may need some debate in ipngwg - 1038 * multiple options does not make sense, however, 1039 * there's no explicit mention in specification. 1040 */ 1041 if (*plenp != 0) { 1042 ip6stat.ip6s_badoptions++; 1043 icmp6_error(m, ICMP6_PARAM_PROB, 1044 ICMP6_PARAMPROB_HEADER, 1045 erroff + opt + 2 - opthead); 1046 return(-1); 1047 } 1048 #endif 1049 1050 /* 1051 * jumbo payload length must be larger than 65535. 1052 */ 1053 if (jumboplen <= IPV6_MAXPACKET) { 1054 ip6stat.ip6s_badoptions++; 1055 icmp6_error(m, ICMP6_PARAM_PROB, 1056 ICMP6_PARAMPROB_HEADER, 1057 erroff + opt + 2 - opthead); 1058 return(-1); 1059 } 1060 *plenp = jumboplen; 1061 1062 break; 1063 default: /* unknown option */ 1064 if (hbhlen < IP6OPT_MINLEN) { 1065 ip6stat.ip6s_toosmall++; 1066 goto bad; 1067 } 1068 optlen = ip6_unknown_opt(opt, m, 1069 erroff + opt - opthead); 1070 if (optlen == -1) 1071 return(-1); 1072 optlen += 2; 1073 break; 1074 } 1075 } 1076 1077 return(0); 1078 1079 bad: 1080 m_freem(m); 1081 return(-1); 1082 } 1083 1084 /* 1085 * Unknown option processing. 1086 * The third argument `off' is the offset from the IPv6 header to the option, 1087 * which is necessary if the IPv6 header the and option header and IPv6 header 1088 * is not continuous in order to return an ICMPv6 error. 1089 */ 1090 int 1091 ip6_unknown_opt(optp, m, off) 1092 u_int8_t *optp; 1093 struct mbuf *m; 1094 int off; 1095 { 1096 struct ip6_hdr *ip6; 1097 1098 switch (IP6OPT_TYPE(*optp)) { 1099 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1100 return((int)*(optp + 1)); 1101 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1102 m_freem(m); 1103 return(-1); 1104 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1105 ip6stat.ip6s_badoptions++; 1106 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1107 return(-1); 1108 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1109 ip6stat.ip6s_badoptions++; 1110 ip6 = mtod(m, struct ip6_hdr *); 1111 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1112 (m->m_flags & (M_BCAST|M_MCAST))) 1113 m_freem(m); 1114 else 1115 icmp6_error(m, ICMP6_PARAM_PROB, 1116 ICMP6_PARAMPROB_OPTION, off); 1117 return(-1); 1118 } 1119 1120 m_freem(m); /* XXX: NOTREACHED */ 1121 return(-1); 1122 } 1123 1124 /* 1125 * Create the "control" list for this pcb. 1126 * The function will not modify mbuf chain at all. 1127 * 1128 * with KAME mbuf chain restriction: 1129 * The routine will be called from upper layer handlers like tcp6_input(). 1130 * Thus the routine assumes that the caller (tcp6_input) have already 1131 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1132 * very first mbuf on the mbuf chain. 1133 */ 1134 void 1135 ip6_savecontrol(in6p, mp, ip6, m) 1136 struct inpcb *in6p; 1137 struct mbuf **mp; 1138 struct ip6_hdr *ip6; 1139 struct mbuf *m; 1140 { 1141 struct proc *p = curproc; /* XXX */ 1142 int privileged = 0; 1143 int rthdr_exist = 0; 1144 1145 1146 if (p && !suser(p)) 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