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/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 extern struct ip6protosw inet6sw[]; 128 129 u_char ip6_protox[IPPROTO_MAX]; 130 static int ip6qmaxlen = IFQ_MAXLEN; 131 struct in6_ifaddr *in6_ifaddr; 132 133 extern struct callout in6_tmpaddrtimer_ch; 134 135 int ip6_forward_srcrt; /* XXX */ 136 int ip6_sourcecheck; /* XXX */ 137 int ip6_sourcecheck_interval; /* XXX */ 138 139 int ip6_ours_check_algorithm; 140 141 142 /* firewall hooks */ 143 ip6_fw_chk_t *ip6_fw_chk_ptr; 144 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 145 int ip6_fw_enable = 1; 146 147 struct ip6stat ip6stat; 148 149 static void ip6_init2 __P((void *)); 150 static struct mbuf *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 151 152 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 153 #ifdef PULLDOWN_TEST 154 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 155 #endif 156 157 158 /* 159 * IP6 initialization: fill in IP6 protocol switch table. 160 * All protocols not implemented in kernel go to raw IP6 protocol handler. 161 */ 162 void 163 ip6_init() 164 { 165 struct ip6protosw *pr; 166 int i; 167 struct timeval tv; 168 169 #ifdef DIAGNOSTIC 170 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 171 panic("sizeof(protosw) != sizeof(ip6protosw)"); 172 #endif 173 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 174 if (pr == 0) 175 panic("ip6_init"); 176 for (i = 0; i < IPPROTO_MAX; i++) 177 ip6_protox[i] = pr - inet6sw; 178 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 179 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 180 if (pr->pr_domain->dom_family == PF_INET6 && 181 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 182 ip6_protox[pr->pr_protocol] = pr - inet6sw; 183 ip6intrq.ifq_maxlen = ip6qmaxlen; 184 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", MTX_DEF); 185 ip6intrq_present = 1; 186 register_netisr(NETISR_IPV6, ip6intr); 187 nd6_init(); 188 frag6_init(); 189 /* 190 * in many cases, random() here does NOT return random number 191 * as initialization during bootstrap time occur in fixed order. 192 */ 193 microtime(&tv); 194 ip6_flow_seq = random() ^ tv.tv_usec; 195 microtime(&tv); 196 ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 197 } 198 199 static void 200 ip6_init2(dummy) 201 void *dummy; 202 { 203 204 /* 205 * to route local address of p2p link to loopback, 206 * assign loopback address first. 207 */ 208 in6_ifattach(&loif[0], NULL); 209 210 /* nd6_timer_init */ 211 callout_init(&nd6_timer_ch, 0); 212 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 213 214 /* router renumbering prefix list maintenance */ 215 callout_init(&in6_rr_timer_ch, 0); 216 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 217 218 /* timer for regeneranation of temporary addresses randomize ID */ 219 callout_reset(&in6_tmpaddrtimer_ch, 220 (ip6_temp_preferred_lifetime - ip6_desync_factor - 221 ip6_temp_regen_advance) * hz, 222 in6_tmpaddrtimer, NULL); 223 } 224 225 /* cheat */ 226 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 227 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 228 229 /* 230 * IP6 input interrupt handling. Just pass the packet to ip6_input. 231 */ 232 void 233 ip6intr() 234 { 235 int s; 236 struct mbuf *m; 237 238 for (;;) { 239 s = splimp(); 240 IF_DEQUEUE(&ip6intrq, m); 241 splx(s); 242 if (m == 0) 243 return; 244 ip6_input(m); 245 } 246 } 247 248 extern struct route_in6 ip6_forward_rt; 249 250 void 251 ip6_input(m) 252 struct mbuf *m; 253 { 254 struct ip6_hdr *ip6; 255 int off = sizeof(struct ip6_hdr), nest; 256 u_int32_t plen; 257 u_int32_t rtalert = ~0; 258 int nxt, ours = 0; 259 struct ifnet *deliverifp = NULL; 260 #ifdef PFIL_HOOKS 261 struct packet_filter_hook *pfh; 262 struct mbuf *m0; 263 int rv; 264 #endif /* PFIL_HOOKS */ 265 266 #ifdef IPSEC 267 /* 268 * should the inner packet be considered authentic? 269 * see comment in ah4_input(). 270 */ 271 if (m) { 272 m->m_flags &= ~M_AUTHIPHDR; 273 m->m_flags &= ~M_AUTHIPDGM; 274 } 275 #endif 276 277 /* 278 * make sure we don't have onion peering information into m_aux. 279 */ 280 ip6_delaux(m); 281 282 /* 283 * mbuf statistics by kazu 284 */ 285 if (m->m_flags & M_EXT) { 286 if (m->m_next) 287 ip6stat.ip6s_mext2m++; 288 else 289 ip6stat.ip6s_mext1++; 290 } else { 291 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 292 if (m->m_next) { 293 if (m->m_flags & M_LOOP) { 294 ip6stat.ip6s_m2m[loif[0].if_index]++; /*XXX*/ 295 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 296 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 297 else 298 ip6stat.ip6s_m2m[0]++; 299 } else 300 ip6stat.ip6s_m1++; 301 #undef M2MMAX 302 } 303 304 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 305 ip6stat.ip6s_total++; 306 307 #ifndef PULLDOWN_TEST 308 /* 309 * L2 bridge code and some other code can return mbuf chain 310 * that does not conform to KAME requirement. too bad. 311 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 312 */ 313 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 314 struct mbuf *n; 315 316 MGETHDR(n, M_DONTWAIT, MT_HEADER); 317 if (n) 318 M_COPY_PKTHDR(n, m); 319 if (n && m->m_pkthdr.len > MHLEN) { 320 MCLGET(n, M_DONTWAIT); 321 if ((n->m_flags & M_EXT) == 0) { 322 m_freem(n); 323 n = NULL; 324 } 325 } 326 if (!n) { 327 m_freem(m); 328 return; /*ENOBUFS*/ 329 } 330 331 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 332 n->m_len = m->m_pkthdr.len; 333 m_freem(m); 334 m = n; 335 } 336 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 337 #endif 338 339 if (m->m_len < sizeof(struct ip6_hdr)) { 340 struct ifnet *inifp; 341 inifp = m->m_pkthdr.rcvif; 342 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 343 ip6stat.ip6s_toosmall++; 344 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 345 return; 346 } 347 } 348 349 ip6 = mtod(m, struct ip6_hdr *); 350 351 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 352 ip6stat.ip6s_badvers++; 353 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 354 goto bad; 355 } 356 357 #ifdef PFIL_HOOKS 358 /* 359 * Run through list of hooks for input packets. If there are any 360 * filters which require that additional packets in the flow are 361 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 362 * Note that filters must _never_ set this flag, as another filter 363 * in the list may have previously cleared it. 364 */ 365 m0 = m; 366 pfh = pfil_hook_get(PFIL_IN, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); 367 for (; pfh; pfh = pfh->pfil_link.tqe_next) 368 if (pfh->pfil_func) { 369 rv = pfh->pfil_func(ip6, sizeof(*ip6), 370 m->m_pkthdr.rcvif, 0, &m0); 371 if (rv) 372 return; 373 m = m0; 374 if (m == NULL) 375 return; 376 ip6 = mtod(m, struct ip6_hdr *); 377 } 378 #endif /* PFIL_HOOKS */ 379 380 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 381 382 /* 383 * Check with the firewall... 384 */ 385 if (ip6_fw_enable && ip6_fw_chk_ptr) { 386 u_short port = 0; 387 /* If ipfw says divert, we have to just drop packet */ 388 /* use port as a dummy argument */ 389 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 390 m_freem(m); 391 m = NULL; 392 } 393 if (!m) 394 return; 395 } 396 397 /* 398 * Check against address spoofing/corruption. 399 */ 400 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 401 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 402 /* 403 * XXX: "badscope" is not very suitable for a multicast source. 404 */ 405 ip6stat.ip6s_badscope++; 406 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 407 goto bad; 408 } 409 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 410 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 411 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 412 ip6stat.ip6s_badscope++; 413 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 414 goto bad; 415 } 416 /* 417 * The following check is not documented in specs. A malicious 418 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 419 * and bypass security checks (act as if it was from 127.0.0.1 by using 420 * IPv6 src ::ffff:127.0.0.1). Be cautious. 421 * 422 * This check chokes if we are in an SIIT cloud. As none of BSDs 423 * support IPv4-less kernel compilation, we cannot support SIIT 424 * environment at all. So, it makes more sense for us to reject any 425 * malicious packets for non-SIIT environment, than try to do a 426 * partical support for SIIT environment. 427 */ 428 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 429 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 430 ip6stat.ip6s_badscope++; 431 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 432 goto bad; 433 } 434 #if 0 435 /* 436 * Reject packets with IPv4 compatible addresses (auto tunnel). 437 * 438 * The code forbids auto tunnel relay case in RFC1933 (the check is 439 * stronger than RFC1933). We may want to re-enable it if mech-xx 440 * is revised to forbid relaying case. 441 */ 442 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 443 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 444 ip6stat.ip6s_badscope++; 445 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 446 goto bad; 447 } 448 #endif 449 450 /* drop packets if interface ID portion is already filled */ 451 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 452 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 453 ip6->ip6_src.s6_addr16[1]) { 454 ip6stat.ip6s_badscope++; 455 goto bad; 456 } 457 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 458 ip6->ip6_dst.s6_addr16[1]) { 459 ip6stat.ip6s_badscope++; 460 goto bad; 461 } 462 } 463 464 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 465 ip6->ip6_src.s6_addr16[1] 466 = htons(m->m_pkthdr.rcvif->if_index); 467 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 468 ip6->ip6_dst.s6_addr16[1] 469 = htons(m->m_pkthdr.rcvif->if_index); 470 471 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 472 /* 473 * We use rt->rt_ifp to determine if the address is ours or not. 474 * If rt_ifp is lo0, the address is ours. 475 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 476 * so any address under fe80::%lo0/64 will be mistakenly considered 477 * local. The special case is supplied to handle the case properly 478 * by actually looking at interface addresses 479 * (using in6ifa_ifpwithaddr). 480 */ 481 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 482 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 483 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 484 icmp6_error(m, ICMP6_DST_UNREACH, 485 ICMP6_DST_UNREACH_ADDR, 0); 486 /* m is already freed */ 487 return; 488 } 489 490 ours = 1; 491 deliverifp = m->m_pkthdr.rcvif; 492 goto hbhcheck; 493 } 494 #endif 495 496 /* 497 * Multicast check 498 */ 499 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 500 struct in6_multi *in6m = 0; 501 502 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 503 /* 504 * See if we belong to the destination multicast group on the 505 * arrival interface. 506 */ 507 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 508 if (in6m) 509 ours = 1; 510 else if (!ip6_mrouter) { 511 ip6stat.ip6s_notmember++; 512 ip6stat.ip6s_cantforward++; 513 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 514 goto bad; 515 } 516 deliverifp = m->m_pkthdr.rcvif; 517 goto hbhcheck; 518 } 519 520 /* 521 * Unicast check 522 */ 523 switch (ip6_ours_check_algorithm) { 524 default: 525 /* 526 * XXX: I intentionally broke our indentation rule here, 527 * since this switch-case is just for measurement and 528 * therefore should soon be removed. 529 */ 530 if (ip6_forward_rt.ro_rt != NULL && 531 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 532 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 533 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 534 ip6stat.ip6s_forward_cachehit++; 535 else { 536 struct sockaddr_in6 *dst6; 537 538 if (ip6_forward_rt.ro_rt) { 539 /* route is down or destination is different */ 540 ip6stat.ip6s_forward_cachemiss++; 541 RTFREE(ip6_forward_rt.ro_rt); 542 ip6_forward_rt.ro_rt = 0; 543 } 544 545 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 546 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 547 dst6->sin6_len = sizeof(struct sockaddr_in6); 548 dst6->sin6_family = AF_INET6; 549 dst6->sin6_addr = ip6->ip6_dst; 550 #ifdef SCOPEDROUTING 551 ip6_forward_rt.ro_dst.sin6_scope_id = 552 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 553 #endif 554 555 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 556 } 557 558 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 559 560 /* 561 * Accept the packet if the forwarding interface to the destination 562 * according to the routing table is the loopback interface, 563 * unless the associated route has a gateway. 564 * Note that this approach causes to accept a packet if there is a 565 * route to the loopback interface for the destination of the packet. 566 * But we think it's even useful in some situations, e.g. when using 567 * a special daemon which wants to intercept the packet. 568 * 569 * XXX: some OSes automatically make a cloned route for the destination 570 * of an outgoing packet. If the outgoing interface of the packet 571 * is a loopback one, the kernel would consider the packet to be 572 * accepted, even if we have no such address assinged on the interface. 573 * We check the cloned flag of the route entry to reject such cases, 574 * assuming that route entries for our own addresses are not made by 575 * cloning (it should be true because in6_addloop explicitly installs 576 * the host route). However, we might have to do an explicit check 577 * while it would be less efficient. Or, should we rather install a 578 * reject route for such a case? 579 */ 580 if (ip6_forward_rt.ro_rt && 581 (ip6_forward_rt.ro_rt->rt_flags & 582 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 583 #ifdef RTF_WASCLONED 584 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 585 #endif 586 #ifdef RTF_CLONED 587 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 588 #endif 589 #if 0 590 /* 591 * The check below is redundant since the comparison of 592 * the destination and the key of the rtentry has 593 * already done through looking up the routing table. 594 */ 595 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 596 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 597 #endif 598 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 599 struct in6_ifaddr *ia6 = 600 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 601 602 /* 603 * record address information into m_aux. 604 */ 605 (void)ip6_setdstifaddr(m, ia6); 606 607 /* 608 * packets to a tentative, duplicated, or somehow invalid 609 * address must not be accepted. 610 */ 611 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 612 /* this address is ready */ 613 ours = 1; 614 deliverifp = ia6->ia_ifp; /* correct? */ 615 /* Count the packet in the ip address stats */ 616 ia6->ia_ifa.if_ipackets++; 617 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 618 goto hbhcheck; 619 } else { 620 /* address is not ready, so discard the packet. */ 621 nd6log((LOG_INFO, 622 "ip6_input: packet to an unready address %s->%s\n", 623 ip6_sprintf(&ip6->ip6_src), 624 ip6_sprintf(&ip6->ip6_dst))); 625 626 goto bad; 627 } 628 } 629 } /* XXX indentation (see above) */ 630 631 /* 632 * FAITH(Firewall Aided Internet Translator) 633 */ 634 if (ip6_keepfaith) { 635 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 636 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 637 /* XXX do we need more sanity checks? */ 638 ours = 1; 639 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/ 640 goto hbhcheck; 641 } 642 } 643 644 /* 645 * Now there is no reason to process the packet if it's not our own 646 * and we're not a router. 647 */ 648 if (!ip6_forwarding) { 649 ip6stat.ip6s_cantforward++; 650 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 651 goto bad; 652 } 653 654 hbhcheck: 655 /* 656 * record address information into m_aux, if we don't have one yet. 657 * note that we are unable to record it, if the address is not listed 658 * as our interface address (e.g. multicast addresses, addresses 659 * within FAITH prefixes and such). 660 */ 661 if (deliverifp && !ip6_getdstifaddr(m)) { 662 struct in6_ifaddr *ia6; 663 664 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 665 if (ia6) { 666 if (!ip6_setdstifaddr(m, ia6)) { 667 /* 668 * XXX maybe we should drop the packet here, 669 * as we could not provide enough information 670 * to the upper layers. 671 */ 672 } 673 } 674 } 675 676 /* 677 * Process Hop-by-Hop options header if it's contained. 678 * m may be modified in ip6_hopopts_input(). 679 * If a JumboPayload option is included, plen will also be modified. 680 */ 681 plen = (u_int32_t)ntohs(ip6->ip6_plen); 682 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 683 struct ip6_hbh *hbh; 684 685 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 686 #if 0 /*touches NULL pointer*/ 687 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 688 #endif 689 return; /* m have already been freed */ 690 } 691 692 /* adjust pointer */ 693 ip6 = mtod(m, struct ip6_hdr *); 694 695 /* 696 * if the payload length field is 0 and the next header field 697 * indicates Hop-by-Hop Options header, then a Jumbo Payload 698 * option MUST be included. 699 */ 700 if (ip6->ip6_plen == 0 && plen == 0) { 701 /* 702 * Note that if a valid jumbo payload option is 703 * contained, ip6_hoptops_input() must set a valid 704 * (non-zero) payload length to the variable plen. 705 */ 706 ip6stat.ip6s_badoptions++; 707 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 708 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 709 icmp6_error(m, ICMP6_PARAM_PROB, 710 ICMP6_PARAMPROB_HEADER, 711 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 712 return; 713 } 714 #ifndef PULLDOWN_TEST 715 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 716 hbh = (struct ip6_hbh *)(ip6 + 1); 717 #else 718 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 719 sizeof(struct ip6_hbh)); 720 if (hbh == NULL) { 721 ip6stat.ip6s_tooshort++; 722 return; 723 } 724 #endif 725 nxt = hbh->ip6h_nxt; 726 727 /* 728 * accept the packet if a router alert option is included 729 * and we act as an IPv6 router. 730 */ 731 if (rtalert != ~0 && ip6_forwarding) 732 ours = 1; 733 } else 734 nxt = ip6->ip6_nxt; 735 736 /* 737 * Check that the amount of data in the buffers 738 * is as at least much as the IPv6 header would have us expect. 739 * Trim mbufs if longer than we expect. 740 * Drop packet if shorter than we expect. 741 */ 742 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 743 ip6stat.ip6s_tooshort++; 744 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 745 goto bad; 746 } 747 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 748 if (m->m_len == m->m_pkthdr.len) { 749 m->m_len = sizeof(struct ip6_hdr) + plen; 750 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 751 } else 752 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 753 } 754 755 /* 756 * Forward if desirable. 757 */ 758 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 759 /* 760 * If we are acting as a multicast router, all 761 * incoming multicast packets are passed to the 762 * kernel-level multicast forwarding function. 763 * The packet is returned (relatively) intact; if 764 * ip6_mforward() returns a non-zero value, the packet 765 * must be discarded, else it may be accepted below. 766 */ 767 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 768 ip6stat.ip6s_cantforward++; 769 m_freem(m); 770 return; 771 } 772 if (!ours) { 773 m_freem(m); 774 return; 775 } 776 } else if (!ours) { 777 ip6_forward(m, 0); 778 return; 779 } 780 781 ip6 = mtod(m, struct ip6_hdr *); 782 783 /* 784 * Malicious party may be able to use IPv4 mapped addr to confuse 785 * tcp/udp stack and bypass security checks (act as if it was from 786 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 787 * 788 * For SIIT end node behavior, you may want to disable the check. 789 * However, you will become vulnerable to attacks using IPv4 mapped 790 * source. 791 */ 792 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 793 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 794 ip6stat.ip6s_badscope++; 795 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 796 goto bad; 797 } 798 799 /* 800 * Tell launch routine the next header 801 */ 802 ip6stat.ip6s_delivered++; 803 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 804 nest = 0; 805 806 while (nxt != IPPROTO_DONE) { 807 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 808 ip6stat.ip6s_toomanyhdr++; 809 goto bad; 810 } 811 812 /* 813 * protection against faulty packet - there should be 814 * more sanity checks in header chain processing. 815 */ 816 if (m->m_pkthdr.len < off) { 817 ip6stat.ip6s_tooshort++; 818 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 819 goto bad; 820 } 821 822 #if 0 823 /* 824 * do we need to do it for every header? yeah, other 825 * functions can play with it (like re-allocate and copy). 826 */ 827 mhist = ip6_addaux(m); 828 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 829 hist = mtod(mhist, caddr_t) + mhist->m_len; 830 bcopy(&nxt, hist, sizeof(nxt)); 831 mhist->m_len += sizeof(nxt); 832 } else { 833 ip6stat.ip6s_toomanyhdr++; 834 goto bad; 835 } 836 #endif 837 838 #ifdef IPSEC 839 /* 840 * enforce IPsec policy checking if we are seeing last header. 841 * note that we do not visit this with protocols with pcb layer 842 * code - like udp/tcp/raw ip. 843 */ 844 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 845 ipsec6_in_reject(m, NULL)) { 846 ipsec6stat.in_polvio++; 847 goto bad; 848 } 849 #endif 850 851 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 852 } 853 return; 854 bad: 855 m_freem(m); 856 } 857 858 /* 859 * set/grab in6_ifaddr correspond to IPv6 destination address. 860 * XXX backward compatibility wrapper 861 */ 862 static struct mbuf * 863 ip6_setdstifaddr(m, ia6) 864 struct mbuf *m; 865 struct in6_ifaddr *ia6; 866 { 867 struct mbuf *n; 868 869 n = ip6_addaux(m); 870 if (n) 871 mtod(n, struct ip6aux *)->ip6a_dstia6 = ia6; 872 return n; /* NULL if failed to set */ 873 } 874 875 struct in6_ifaddr * 876 ip6_getdstifaddr(m) 877 struct mbuf *m; 878 { 879 struct mbuf *n; 880 881 n = ip6_findaux(m); 882 if (n) 883 return mtod(n, struct ip6aux *)->ip6a_dstia6; 884 else 885 return NULL; 886 } 887 888 /* 889 * Hop-by-Hop options header processing. If a valid jumbo payload option is 890 * included, the real payload length will be stored in plenp. 891 */ 892 static int 893 ip6_hopopts_input(plenp, rtalertp, mp, offp) 894 u_int32_t *plenp; 895 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 896 struct mbuf **mp; 897 int *offp; 898 { 899 struct mbuf *m = *mp; 900 int off = *offp, hbhlen; 901 struct ip6_hbh *hbh; 902 u_int8_t *opt; 903 904 /* validation of the length of the header */ 905 #ifndef PULLDOWN_TEST 906 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 907 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 908 hbhlen = (hbh->ip6h_len + 1) << 3; 909 910 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 911 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 912 #else 913 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 914 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 915 if (hbh == NULL) { 916 ip6stat.ip6s_tooshort++; 917 return -1; 918 } 919 hbhlen = (hbh->ip6h_len + 1) << 3; 920 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 921 hbhlen); 922 if (hbh == NULL) { 923 ip6stat.ip6s_tooshort++; 924 return -1; 925 } 926 #endif 927 off += hbhlen; 928 hbhlen -= sizeof(struct ip6_hbh); 929 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 930 931 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 932 hbhlen, rtalertp, plenp) < 0) 933 return(-1); 934 935 *offp = off; 936 *mp = m; 937 return(0); 938 } 939 940 /* 941 * Search header for all Hop-by-hop options and process each option. 942 * This function is separate from ip6_hopopts_input() in order to 943 * handle a case where the sending node itself process its hop-by-hop 944 * options header. In such a case, the function is called from ip6_output(). 945 * 946 * The function assumes that hbh header is located right after the IPv6 header 947 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 948 * opthead + hbhlen is located in continuous memory region. 949 */ 950 int 951 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 952 struct mbuf *m; 953 u_int8_t *opthead; 954 int hbhlen; 955 u_int32_t *rtalertp; 956 u_int32_t *plenp; 957 { 958 struct ip6_hdr *ip6; 959 int optlen = 0; 960 u_int8_t *opt = opthead; 961 u_int16_t rtalert_val; 962 u_int32_t jumboplen; 963 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 964 965 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 966 switch (*opt) { 967 case IP6OPT_PAD1: 968 optlen = 1; 969 break; 970 case IP6OPT_PADN: 971 if (hbhlen < IP6OPT_MINLEN) { 972 ip6stat.ip6s_toosmall++; 973 goto bad; 974 } 975 optlen = *(opt + 1) + 2; 976 break; 977 case IP6OPT_RTALERT: 978 /* XXX may need check for alignment */ 979 if (hbhlen < IP6OPT_RTALERT_LEN) { 980 ip6stat.ip6s_toosmall++; 981 goto bad; 982 } 983 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 984 /* XXX stat */ 985 icmp6_error(m, ICMP6_PARAM_PROB, 986 ICMP6_PARAMPROB_HEADER, 987 erroff + opt + 1 - opthead); 988 return(-1); 989 } 990 optlen = IP6OPT_RTALERT_LEN; 991 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 992 *rtalertp = ntohs(rtalert_val); 993 break; 994 case IP6OPT_JUMBO: 995 /* XXX may need check for alignment */ 996 if (hbhlen < IP6OPT_JUMBO_LEN) { 997 ip6stat.ip6s_toosmall++; 998 goto bad; 999 } 1000 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1001 /* XXX stat */ 1002 icmp6_error(m, ICMP6_PARAM_PROB, 1003 ICMP6_PARAMPROB_HEADER, 1004 erroff + opt + 1 - opthead); 1005 return(-1); 1006 } 1007 optlen = IP6OPT_JUMBO_LEN; 1008 1009 /* 1010 * IPv6 packets that have non 0 payload length 1011 * must not contain a jumbo payload option. 1012 */ 1013 ip6 = mtod(m, struct ip6_hdr *); 1014 if (ip6->ip6_plen) { 1015 ip6stat.ip6s_badoptions++; 1016 icmp6_error(m, ICMP6_PARAM_PROB, 1017 ICMP6_PARAMPROB_HEADER, 1018 erroff + opt - opthead); 1019 return(-1); 1020 } 1021 1022 /* 1023 * We may see jumbolen in unaligned location, so 1024 * we'd need to perform bcopy(). 1025 */ 1026 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1027 jumboplen = (u_int32_t)htonl(jumboplen); 1028 1029 #if 1 1030 /* 1031 * if there are multiple jumbo payload options, 1032 * *plenp will be non-zero and the packet will be 1033 * rejected. 1034 * the behavior may need some debate in ipngwg - 1035 * multiple options does not make sense, however, 1036 * there's no explicit mention in specification. 1037 */ 1038 if (*plenp != 0) { 1039 ip6stat.ip6s_badoptions++; 1040 icmp6_error(m, ICMP6_PARAM_PROB, 1041 ICMP6_PARAMPROB_HEADER, 1042 erroff + opt + 2 - opthead); 1043 return(-1); 1044 } 1045 #endif 1046 1047 /* 1048 * jumbo payload length must be larger than 65535. 1049 */ 1050 if (jumboplen <= IPV6_MAXPACKET) { 1051 ip6stat.ip6s_badoptions++; 1052 icmp6_error(m, ICMP6_PARAM_PROB, 1053 ICMP6_PARAMPROB_HEADER, 1054 erroff + opt + 2 - opthead); 1055 return(-1); 1056 } 1057 *plenp = jumboplen; 1058 1059 break; 1060 default: /* unknown option */ 1061 if (hbhlen < IP6OPT_MINLEN) { 1062 ip6stat.ip6s_toosmall++; 1063 goto bad; 1064 } 1065 optlen = ip6_unknown_opt(opt, m, 1066 erroff + opt - opthead); 1067 if (optlen == -1) 1068 return(-1); 1069 optlen += 2; 1070 break; 1071 } 1072 } 1073 1074 return(0); 1075 1076 bad: 1077 m_freem(m); 1078 return(-1); 1079 } 1080 1081 /* 1082 * Unknown option processing. 1083 * The third argument `off' is the offset from the IPv6 header to the option, 1084 * which is necessary if the IPv6 header the and option header and IPv6 header 1085 * is not continuous in order to return an ICMPv6 error. 1086 */ 1087 int 1088 ip6_unknown_opt(optp, m, off) 1089 u_int8_t *optp; 1090 struct mbuf *m; 1091 int off; 1092 { 1093 struct ip6_hdr *ip6; 1094 1095 switch (IP6OPT_TYPE(*optp)) { 1096 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1097 return((int)*(optp + 1)); 1098 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1099 m_freem(m); 1100 return(-1); 1101 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1102 ip6stat.ip6s_badoptions++; 1103 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1104 return(-1); 1105 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1106 ip6stat.ip6s_badoptions++; 1107 ip6 = mtod(m, struct ip6_hdr *); 1108 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1109 (m->m_flags & (M_BCAST|M_MCAST))) 1110 m_freem(m); 1111 else 1112 icmp6_error(m, ICMP6_PARAM_PROB, 1113 ICMP6_PARAMPROB_OPTION, off); 1114 return(-1); 1115 } 1116 1117 m_freem(m); /* XXX: NOTREACHED */ 1118 return(-1); 1119 } 1120 1121 /* 1122 * Create the "control" list for this pcb. 1123 * The function will not modify mbuf chain at all. 1124 * 1125 * with KAME mbuf chain restriction: 1126 * The routine will be called from upper layer handlers like tcp6_input(). 1127 * Thus the routine assumes that the caller (tcp6_input) have already 1128 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1129 * very first mbuf on the mbuf chain. 1130 */ 1131 void 1132 ip6_savecontrol(in6p, mp, ip6, m) 1133 struct inpcb *in6p; 1134 struct mbuf **mp; 1135 struct ip6_hdr *ip6; 1136 struct mbuf *m; 1137 { 1138 struct proc *p = curproc; /* XXX */ 1139 int privileged = 0; 1140 int rthdr_exist = 0; 1141 1142 1143 if (p && !suser(p)) 1144 privileged++; 1145 1146 #ifdef SO_TIMESTAMP 1147 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1148 struct timeval tv; 1149 1150 microtime(&tv); 1151 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1152 SCM_TIMESTAMP, SOL_SOCKET); 1153 if (*mp) { 1154 mp = &(*mp)->m_next; 1155 } 1156 } 1157 #endif 1158 1159 /* RFC 2292 sec. 5 */ 1160 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1161 struct in6_pktinfo pi6; 1162 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1163 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1164 pi6.ipi6_addr.s6_addr16[1] = 0; 1165 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1166 ? m->m_pkthdr.rcvif->if_index 1167 : 0; 1168 *mp = sbcreatecontrol((caddr_t) &pi6, 1169 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1170 IPPROTO_IPV6); 1171 if (*mp) 1172 mp = &(*mp)->m_next; 1173 } 1174 1175 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1176 int hlim = ip6->ip6_hlim & 0xff; 1177 *mp = sbcreatecontrol((caddr_t) &hlim, 1178 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1179 if (*mp) 1180 mp = &(*mp)->m_next; 1181 } 1182 1183 /* 1184 * IPV6_HOPOPTS socket option. We require super-user privilege 1185 * for the option, but it might be too strict, since there might 1186 * be some hop-by-hop options which can be returned to normal user. 1187 * See RFC 2292 section 6. 1188 */ 1189 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { 1190 /* 1191 * Check if a hop-by-hop options header is contatined in the 1192 * received packet, and if so, store the options as ancillary 1193 * data. Note that a hop-by-hop options header must be 1194 * just after the IPv6 header, which fact is assured through 1195 * the IPv6 input processing. 1196 */ 1197 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1198 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1199 struct ip6_hbh *hbh; 1200 int hbhlen = 0; 1201 #ifdef PULLDOWN_TEST 1202 struct mbuf *ext; 1203 #endif 1204 1205 #ifndef PULLDOWN_TEST 1206 hbh = (struct ip6_hbh *)(ip6 + 1); 1207 hbhlen = (hbh->ip6h_len + 1) << 3; 1208 #else 1209 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1210 ip6->ip6_nxt); 1211 if (ext == NULL) { 1212 ip6stat.ip6s_tooshort++; 1213 return; 1214 } 1215 hbh = mtod(ext, struct ip6_hbh *); 1216 hbhlen = (hbh->ip6h_len + 1) << 3; 1217 if (hbhlen != ext->m_len) { 1218 m_freem(ext); 1219 ip6stat.ip6s_tooshort++; 1220 return; 1221 } 1222 #endif 1223 1224 /* 1225 * XXX: We copy whole the header even if a jumbo 1226 * payload option is included, which option is to 1227 * be removed before returning in the RFC 2292. 1228 * Note: this constraint is removed in 2292bis. 1229 */ 1230 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1231 IPV6_HOPOPTS, IPPROTO_IPV6); 1232 if (*mp) 1233 mp = &(*mp)->m_next; 1234 #ifdef PULLDOWN_TEST 1235 m_freem(ext); 1236 #endif 1237 } 1238 } 1239 1240 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1241 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1242 int proto, off, nxt; 1243 1244 /* 1245 * go through the header chain to see if a routing header is 1246 * contained in the packet. We need this information to store 1247 * destination options headers (if any) properly. 1248 * XXX: performance issue. We should record this info when 1249 * processing extension headers in incoming routine. 1250 * (todo) use m_aux? 1251 */ 1252 proto = IPPROTO_IPV6; 1253 off = 0; 1254 nxt = -1; 1255 while (1) { 1256 int newoff; 1257 1258 newoff = ip6_nexthdr(m, off, proto, &nxt); 1259 if (newoff < 0) 1260 break; 1261 if (newoff < off) /* invalid, check for safety */ 1262 break; 1263 if ((proto = nxt) == IPPROTO_ROUTING) { 1264 rthdr_exist = 1; 1265 break; 1266 } 1267 off = newoff; 1268 } 1269 } 1270 1271 if ((in6p->in6p_flags & 1272 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1273 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1274 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1275 1276 /* 1277 * Search for destination options headers or routing 1278 * header(s) through the header chain, and stores each 1279 * header as ancillary data. 1280 * Note that the order of the headers remains in 1281 * the chain of ancillary data. 1282 */ 1283 while (1) { /* is explicit loop prevention necessary? */ 1284 struct ip6_ext *ip6e = NULL; 1285 int elen; 1286 #ifdef PULLDOWN_TEST 1287 struct mbuf *ext = NULL; 1288 #endif 1289 1290 /* 1291 * if it is not an extension header, don't try to 1292 * pull it from the chain. 1293 */ 1294 switch (nxt) { 1295 case IPPROTO_DSTOPTS: 1296 case IPPROTO_ROUTING: 1297 case IPPROTO_HOPOPTS: 1298 case IPPROTO_AH: /* is it possible? */ 1299 break; 1300 default: 1301 goto loopend; 1302 } 1303 1304 #ifndef PULLDOWN_TEST 1305 if (off + sizeof(*ip6e) > m->m_len) 1306 goto loopend; 1307 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1308 if (nxt == IPPROTO_AH) 1309 elen = (ip6e->ip6e_len + 2) << 2; 1310 else 1311 elen = (ip6e->ip6e_len + 1) << 3; 1312 if (off + elen > m->m_len) 1313 goto loopend; 1314 #else 1315 ext = ip6_pullexthdr(m, off, nxt); 1316 if (ext == NULL) { 1317 ip6stat.ip6s_tooshort++; 1318 return; 1319 } 1320 ip6e = mtod(ext, struct ip6_ext *); 1321 if (nxt == IPPROTO_AH) 1322 elen = (ip6e->ip6e_len + 2) << 2; 1323 else 1324 elen = (ip6e->ip6e_len + 1) << 3; 1325 if (elen != ext->m_len) { 1326 m_freem(ext); 1327 ip6stat.ip6s_tooshort++; 1328 return; 1329 } 1330 #endif 1331 1332 switch (nxt) { 1333 case IPPROTO_DSTOPTS: 1334 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1335 break; 1336 1337 /* 1338 * We also require super-user privilege for 1339 * the option. 1340 * See the comments on IN6_HOPOPTS. 1341 */ 1342 if (!privileged) 1343 break; 1344 1345 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1346 IPV6_DSTOPTS, 1347 IPPROTO_IPV6); 1348 if (*mp) 1349 mp = &(*mp)->m_next; 1350 break; 1351 case IPPROTO_ROUTING: 1352 if (!in6p->in6p_flags & IN6P_RTHDR) 1353 break; 1354 1355 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1356 IPV6_RTHDR, 1357 IPPROTO_IPV6); 1358 if (*mp) 1359 mp = &(*mp)->m_next; 1360 break; 1361 case IPPROTO_HOPOPTS: 1362 case IPPROTO_AH: /* is it possible? */ 1363 break; 1364 1365 default: 1366 /* 1367 * other cases have been filtered in the above. 1368 * none will visit this case. here we supply 1369 * the code just in case (nxt overwritten or 1370 * other cases). 1371 */ 1372 #ifdef PULLDOWN_TEST 1373 m_freem(ext); 1374 #endif 1375 goto loopend; 1376 1377 } 1378 1379 /* proceed with the next header. */ 1380 off += elen; 1381 nxt = ip6e->ip6e_nxt; 1382 ip6e = NULL; 1383 #ifdef PULLDOWN_TEST 1384 m_freem(ext); 1385 ext = NULL; 1386 #endif 1387 } 1388 loopend: 1389 ; 1390 } 1391 1392 } 1393 1394 #ifdef PULLDOWN_TEST 1395 /* 1396 * pull single extension header from mbuf chain. returns single mbuf that 1397 * contains the result, or NULL on error. 1398 */ 1399 static struct mbuf * 1400 ip6_pullexthdr(m, off, nxt) 1401 struct mbuf *m; 1402 size_t off; 1403 int nxt; 1404 { 1405 struct ip6_ext ip6e; 1406 size_t elen; 1407 struct mbuf *n; 1408 1409 #ifdef DIAGNOSTIC 1410 switch (nxt) { 1411 case IPPROTO_DSTOPTS: 1412 case IPPROTO_ROUTING: 1413 case IPPROTO_HOPOPTS: 1414 case IPPROTO_AH: /* is it possible? */ 1415 break; 1416 default: 1417 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1418 } 1419 #endif 1420 1421 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1422 if (nxt == IPPROTO_AH) 1423 elen = (ip6e.ip6e_len + 2) << 2; 1424 else 1425 elen = (ip6e.ip6e_len + 1) << 3; 1426 1427 MGET(n, M_DONTWAIT, MT_DATA); 1428 if (n && elen >= MLEN) { 1429 MCLGET(n, M_DONTWAIT); 1430 if ((n->m_flags & M_EXT) == 0) { 1431 m_free(n); 1432 n = NULL; 1433 } 1434 } 1435 if (!n) 1436 return NULL; 1437 1438 n->m_len = 0; 1439 if (elen >= M_TRAILINGSPACE(n)) { 1440 m_free(n); 1441 return NULL; 1442 } 1443 1444 m_copydata(m, off, elen, mtod(n, caddr_t)); 1445 n->m_len = elen; 1446 return n; 1447 } 1448 #endif 1449 1450 /* 1451 * Get pointer to the previous header followed by the header 1452 * currently processed. 1453 * XXX: This function supposes that 1454 * M includes all headers, 1455 * the next header field and the header length field of each header 1456 * are valid, and 1457 * the sum of each header length equals to OFF. 1458 * Because of these assumptions, this function must be called very 1459 * carefully. Moreover, it will not be used in the near future when 1460 * we develop `neater' mechanism to process extension headers. 1461 */ 1462 char * 1463 ip6_get_prevhdr(m, off) 1464 struct mbuf *m; 1465 int off; 1466 { 1467 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1468 1469 if (off == sizeof(struct ip6_hdr)) 1470 return(&ip6->ip6_nxt); 1471 else { 1472 int len, nxt; 1473 struct ip6_ext *ip6e = NULL; 1474 1475 nxt = ip6->ip6_nxt; 1476 len = sizeof(struct ip6_hdr); 1477 while (len < off) { 1478 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1479 1480 switch (nxt) { 1481 case IPPROTO_FRAGMENT: 1482 len += sizeof(struct ip6_frag); 1483 break; 1484 case IPPROTO_AH: 1485 len += (ip6e->ip6e_len + 2) << 2; 1486 break; 1487 default: 1488 len += (ip6e->ip6e_len + 1) << 3; 1489 break; 1490 } 1491 nxt = ip6e->ip6e_nxt; 1492 } 1493 if (ip6e) 1494 return(&ip6e->ip6e_nxt); 1495 else 1496 return NULL; 1497 } 1498 } 1499 1500 /* 1501 * get next header offset. m will be retained. 1502 */ 1503 int 1504 ip6_nexthdr(m, off, proto, nxtp) 1505 struct mbuf *m; 1506 int off; 1507 int proto; 1508 int *nxtp; 1509 { 1510 struct ip6_hdr ip6; 1511 struct ip6_ext ip6e; 1512 struct ip6_frag fh; 1513 1514 /* just in case */ 1515 if (m == NULL) 1516 panic("ip6_nexthdr: m == NULL"); 1517 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1518 return -1; 1519 1520 switch (proto) { 1521 case IPPROTO_IPV6: 1522 if (m->m_pkthdr.len < off + sizeof(ip6)) 1523 return -1; 1524 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1525 if (nxtp) 1526 *nxtp = ip6.ip6_nxt; 1527 off += sizeof(ip6); 1528 return off; 1529 1530 case IPPROTO_FRAGMENT: 1531 /* 1532 * terminate parsing if it is not the first fragment, 1533 * it does not make sense to parse through it. 1534 */ 1535 if (m->m_pkthdr.len < off + sizeof(fh)) 1536 return -1; 1537 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1538 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1539 return -1; 1540 if (nxtp) 1541 *nxtp = fh.ip6f_nxt; 1542 off += sizeof(struct ip6_frag); 1543 return off; 1544 1545 case IPPROTO_AH: 1546 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1547 return -1; 1548 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1549 if (nxtp) 1550 *nxtp = ip6e.ip6e_nxt; 1551 off += (ip6e.ip6e_len + 2) << 2; 1552 return off; 1553 1554 case IPPROTO_HOPOPTS: 1555 case IPPROTO_ROUTING: 1556 case IPPROTO_DSTOPTS: 1557 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1558 return -1; 1559 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1560 if (nxtp) 1561 *nxtp = ip6e.ip6e_nxt; 1562 off += (ip6e.ip6e_len + 1) << 3; 1563 return off; 1564 1565 case IPPROTO_NONE: 1566 case IPPROTO_ESP: 1567 case IPPROTO_IPCOMP: 1568 /* give up */ 1569 return -1; 1570 1571 default: 1572 return -1; 1573 } 1574 1575 return -1; 1576 } 1577 1578 /* 1579 * get offset for the last header in the chain. m will be kept untainted. 1580 */ 1581 int 1582 ip6_lasthdr(m, off, proto, nxtp) 1583 struct mbuf *m; 1584 int off; 1585 int proto; 1586 int *nxtp; 1587 { 1588 int newoff; 1589 int nxt; 1590 1591 if (!nxtp) { 1592 nxt = -1; 1593 nxtp = &nxt; 1594 } 1595 while (1) { 1596 newoff = ip6_nexthdr(m, off, proto, nxtp); 1597 if (newoff < 0) 1598 return off; 1599 else if (newoff < off) 1600 return -1; /* invalid */ 1601 else if (newoff == off) 1602 return newoff; 1603 1604 off = newoff; 1605 proto = *nxtp; 1606 } 1607 } 1608 1609 struct mbuf * 1610 ip6_addaux(m) 1611 struct mbuf *m; 1612 { 1613 struct mbuf *n; 1614 1615 #ifdef DIAGNOSTIC 1616 if (sizeof(struct ip6aux) > MHLEN) 1617 panic("assumption failed on sizeof(ip6aux)"); 1618 #endif 1619 n = m_aux_find(m, AF_INET6, -1); 1620 if (n) { 1621 if (n->m_len < sizeof(struct ip6aux)) { 1622 printf("conflicting use of ip6aux"); 1623 return NULL; 1624 } 1625 } else { 1626 n = m_aux_add(m, AF_INET6, -1); 1627 n->m_len = sizeof(struct ip6aux); 1628 bzero(mtod(n, caddr_t), n->m_len); 1629 } 1630 return n; 1631 } 1632 1633 struct mbuf * 1634 ip6_findaux(m) 1635 struct mbuf *m; 1636 { 1637 struct mbuf *n; 1638 1639 n = m_aux_find(m, AF_INET6, -1); 1640 if (n && n->m_len < sizeof(struct ip6aux)) { 1641 printf("conflicting use of ip6aux"); 1642 n = NULL; 1643 } 1644 return n; 1645 } 1646 1647 void 1648 ip6_delaux(m) 1649 struct mbuf *m; 1650 { 1651 struct mbuf *n; 1652 1653 n = m_aux_find(m, AF_INET6, -1); 1654 if (n) 1655 m_aux_delete(m, n); 1656 } 1657 1658 /* 1659 * System control for IP6 1660 */ 1661 1662 u_char inet6ctlerrmap[PRC_NCMDS] = { 1663 0, 0, 0, 0, 1664 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1665 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1666 EMSGSIZE, EHOSTUNREACH, 0, 0, 1667 0, 0, 0, 0, 1668 ENOPROTOOPT 1669 }; 1670