Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet6/ip6_input.c
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1 /* $FreeBSD$ */ 2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 66 */ 67 68 #include "opt_ip6fw.h" 69 #include "opt_inet.h" 70 #include "opt_inet6.h" 71 #include "opt_ipsec.h" 72 73 #include <sys/param.h> 74 #include <sys/systm.h> 75 #include <sys/malloc.h> 76 #include <sys/mbuf.h> 77 #include <sys/domain.h> 78 #include <sys/protosw.h> 79 #include <sys/socket.h> 80 #include <sys/socketvar.h> 81 #include <sys/errno.h> 82 #include <sys/time.h> 83 #include <sys/kernel.h> 84 #include <sys/syslog.h> 85 #include <sys/proc.h> 86 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 94 #include <netinet/in.h> 95 #include <netinet/in_systm.h> 96 #ifdef INET 97 #include <netinet/ip.h> 98 #include <netinet/ip_icmp.h> 99 #endif /* INET */ 100 #include <netinet/ip6.h> 101 #include <netinet6/in6_var.h> 102 #include <netinet6/ip6_var.h> 103 #include <netinet/in_pcb.h> 104 #include <netinet/icmp6.h> 105 #include <netinet6/in6_ifattach.h> 106 #include <netinet6/nd6.h> 107 #include <netinet6/in6_prefix.h> 108 109 #ifdef IPSEC 110 #include <netinet6/ipsec.h> 111 #ifdef INET6 112 #include <netinet6/ipsec6.h> 113 #endif 114 #endif 115 116 #ifdef FAST_IPSEC 117 #include <netipsec/ipsec.h> 118 #include <netipsec/ipsec6.h> 119 #define IPSEC 120 #endif /* FAST_IPSEC */ 121 122 #include <netinet6/ip6_fw.h> 123 124 #include <netinet6/ip6protosw.h> 125 126 /* we need it for NLOOP. */ 127 #include "loop.h" 128 129 #include <net/net_osdep.h> 130 131 extern int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **)); 132 133 extern struct domain inet6domain; 134 extern struct ip6protosw inet6sw[]; 135 136 u_char ip6_protox[IPPROTO_MAX]; 137 static int ip6qmaxlen = IFQ_MAXLEN; 138 struct in6_ifaddr *in6_ifaddr; 139 140 extern struct callout in6_tmpaddrtimer_ch; 141 142 int ip6_forward_srcrt; /* XXX */ 143 int ip6_sourcecheck; /* XXX */ 144 int ip6_sourcecheck_interval; /* XXX */ 145 const int int6intrq_present = 1; 146 147 int ip6_ours_check_algorithm; 148 149 150 /* firewall hooks */ 151 ip6_fw_chk_t *ip6_fw_chk_ptr; 152 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 153 int ip6_fw_enable = 1; 154 155 struct ip6stat ip6stat; 156 157 static void ip6_init2 __P((void *)); 158 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 159 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 160 #ifdef PULLDOWN_TEST 161 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 162 #endif 163 164 165 /* 166 * IP6 initialization: fill in IP6 protocol switch table. 167 * All protocols not implemented in kernel go to raw IP6 protocol handler. 168 */ 169 void 170 ip6_init() 171 { 172 struct ip6protosw *pr; 173 int i; 174 struct timeval tv; 175 176 #ifdef DIAGNOSTIC 177 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 178 panic("sizeof(protosw) != sizeof(ip6protosw)"); 179 #endif 180 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 181 if (pr == 0) 182 panic("ip6_init"); 183 for (i = 0; i < IPPROTO_MAX; i++) 184 ip6_protox[i] = pr - inet6sw; 185 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 186 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 187 if (pr->pr_domain->dom_family == PF_INET6 && 188 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 189 ip6_protox[pr->pr_protocol] = pr - inet6sw; 190 ip6intrq.ifq_maxlen = ip6qmaxlen; 191 register_netisr(NETISR_IPV6, ip6intr); 192 nd6_init(); 193 frag6_init(); 194 /* 195 * in many cases, random() here does NOT return random number 196 * as initialization during bootstrap time occur in fixed order. 197 */ 198 microtime(&tv); 199 ip6_flow_seq = random() ^ tv.tv_usec; 200 microtime(&tv); 201 ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 202 } 203 204 static void 205 ip6_init2(dummy) 206 void *dummy; 207 { 208 209 /* 210 * to route local address of p2p link to loopback, 211 * assign loopback address first. 212 */ 213 in6_ifattach(&loif[0], NULL); 214 215 /* nd6_timer_init */ 216 callout_init(&nd6_timer_ch); 217 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 218 219 /* router renumbering prefix list maintenance */ 220 callout_init(&in6_rr_timer_ch); 221 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 222 223 /* timer for regeneranation of temporary addresses randomize ID */ 224 callout_reset(&in6_tmpaddrtimer_ch, 225 (ip6_temp_preferred_lifetime - ip6_desync_factor - 226 ip6_temp_regen_advance) * hz, 227 in6_tmpaddrtimer, NULL); 228 } 229 230 /* cheat */ 231 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 232 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 233 234 /* 235 * IP6 input interrupt handling. Just pass the packet to ip6_input. 236 */ 237 void 238 ip6intr() 239 { 240 int s; 241 struct mbuf *m; 242 243 for (;;) { 244 s = splimp(); 245 IF_DEQUEUE(&ip6intrq, m); 246 splx(s); 247 if (m == 0) 248 return; 249 ip6_input(m); 250 } 251 } 252 253 extern struct route_in6 ip6_forward_rt; 254 255 void 256 ip6_input(m) 257 struct mbuf *m; 258 { 259 struct ip6_hdr *ip6; 260 int off = sizeof(struct ip6_hdr), nest; 261 u_int32_t plen; 262 u_int32_t rtalert = ~0; 263 int nxt, ours = 0; 264 struct ifnet *deliverifp = NULL; 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 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_MOVE_PKTHDR(n, m); 319 if (n && n->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 == NULL) { 327 m_freem(m); 328 return; /*ENOBUFS*/ 329 } 330 331 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 332 n->m_len = n->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 /* 358 * Check if we want to allow this packet to be processed. 359 * Consider it to be bad if not. 360 */ 361 if (fr_checkp) { 362 struct mbuf *m1 = m; 363 364 if ((*fr_checkp)((struct ip *)ip6, sizeof(*ip6), 365 m->m_pkthdr.rcvif, 0, &m1) != 0) 366 return; 367 m = m1; 368 if (m == NULL) 369 return; 370 ip6 = mtod(m, struct ip6_hdr *); 371 } 372 373 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 374 375 /* 376 * Check with the firewall... 377 */ 378 if (ip6_fw_enable && ip6_fw_chk_ptr) { 379 u_short port = 0; 380 /* If ipfw says divert, we have to just drop packet */ 381 /* use port as a dummy argument */ 382 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 383 m_freem(m); 384 m = NULL; 385 } 386 if (!m) 387 return; 388 } 389 390 /* 391 * Check against address spoofing/corruption. 392 */ 393 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 394 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 395 /* 396 * XXX: "badscope" is not very suitable for a multicast source. 397 */ 398 ip6stat.ip6s_badscope++; 399 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 400 goto bad; 401 } 402 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 403 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 404 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 405 ip6stat.ip6s_badscope++; 406 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 407 goto bad; 408 } 409 410 /* 411 * The following check is not documented in specs. A malicious 412 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 413 * and bypass security checks (act as if it was from 127.0.0.1 by using 414 * IPv6 src ::ffff:127.0.0.1). Be cautious. 415 * 416 * This check chokes if we are in an SIIT cloud. As none of BSDs 417 * support IPv4-less kernel compilation, we cannot support SIIT 418 * environment at all. So, it makes more sense for us to reject any 419 * malicious packets for non-SIIT environment, than try to do a 420 * partical support for SIIT environment. 421 */ 422 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 423 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 424 ip6stat.ip6s_badscope++; 425 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 426 goto bad; 427 } 428 #if 0 429 /* 430 * Reject packets with IPv4 compatible addresses (auto tunnel). 431 * 432 * The code forbids auto tunnel relay case in RFC1933 (the check is 433 * stronger than RFC1933). We may want to re-enable it if mech-xx 434 * is revised to forbid relaying case. 435 */ 436 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 437 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 438 ip6stat.ip6s_badscope++; 439 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 440 goto bad; 441 } 442 #endif 443 444 /* drop packets if interface ID portion is already filled */ 445 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 446 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 447 ip6->ip6_src.s6_addr16[1]) { 448 ip6stat.ip6s_badscope++; 449 goto bad; 450 } 451 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 452 ip6->ip6_dst.s6_addr16[1]) { 453 ip6stat.ip6s_badscope++; 454 goto bad; 455 } 456 } 457 458 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 459 ip6->ip6_src.s6_addr16[1] 460 = htons(m->m_pkthdr.rcvif->if_index); 461 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 462 ip6->ip6_dst.s6_addr16[1] 463 = htons(m->m_pkthdr.rcvif->if_index); 464 465 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 466 /* 467 * We use rt->rt_ifp to determine if the address is ours or not. 468 * If rt_ifp is lo0, the address is ours. 469 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 470 * so any address under fe80::%lo0/64 will be mistakenly considered 471 * local. The special case is supplied to handle the case properly 472 * by actually looking at interface addresses 473 * (using in6ifa_ifpwithaddr). 474 */ 475 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 476 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 477 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 478 icmp6_error(m, ICMP6_DST_UNREACH, 479 ICMP6_DST_UNREACH_ADDR, 0); 480 /* m is already freed */ 481 return; 482 } 483 484 ours = 1; 485 deliverifp = m->m_pkthdr.rcvif; 486 goto hbhcheck; 487 } 488 #endif 489 490 /* 491 * Multicast check 492 */ 493 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 494 struct in6_multi *in6m = 0; 495 496 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 497 /* 498 * See if we belong to the destination multicast group on the 499 * arrival interface. 500 */ 501 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 502 if (in6m) 503 ours = 1; 504 else if (!ip6_mrouter) { 505 ip6stat.ip6s_notmember++; 506 ip6stat.ip6s_cantforward++; 507 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 508 goto bad; 509 } 510 deliverifp = m->m_pkthdr.rcvif; 511 goto hbhcheck; 512 } 513 514 /* 515 * Unicast check 516 */ 517 switch (ip6_ours_check_algorithm) { 518 default: 519 /* 520 * XXX: I intentionally broke our indentation rule here, 521 * since this switch-case is just for measurement and 522 * therefore should soon be removed. 523 */ 524 if (ip6_forward_rt.ro_rt != NULL && 525 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 526 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 527 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 528 ip6stat.ip6s_forward_cachehit++; 529 else { 530 struct sockaddr_in6 *dst6; 531 532 if (ip6_forward_rt.ro_rt) { 533 /* route is down or destination is different */ 534 ip6stat.ip6s_forward_cachemiss++; 535 RTFREE(ip6_forward_rt.ro_rt); 536 ip6_forward_rt.ro_rt = 0; 537 } 538 539 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 540 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 541 dst6->sin6_len = sizeof(struct sockaddr_in6); 542 dst6->sin6_family = AF_INET6; 543 dst6->sin6_addr = ip6->ip6_dst; 544 #ifdef SCOPEDROUTING 545 ip6_forward_rt.ro_dst.sin6_scope_id = 546 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 547 #endif 548 549 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 550 } 551 552 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 553 554 /* 555 * Accept the packet if the forwarding interface to the destination 556 * according to the routing table is the loopback interface, 557 * unless the associated route has a gateway. 558 * Note that this approach causes to accept a packet if there is a 559 * route to the loopback interface for the destination of the packet. 560 * But we think it's even useful in some situations, e.g. when using 561 * a special daemon which wants to intercept the packet. 562 * 563 * XXX: some OSes automatically make a cloned route for the destination 564 * of an outgoing packet. If the outgoing interface of the packet 565 * is a loopback one, the kernel would consider the packet to be 566 * accepted, even if we have no such address assinged on the interface. 567 * We check the cloned flag of the route entry to reject such cases, 568 * assuming that route entries for our own addresses are not made by 569 * cloning (it should be true because in6_addloop explicitly installs 570 * the host route). However, we might have to do an explicit check 571 * while it would be less efficient. Or, should we rather install a 572 * reject route for such a case? 573 */ 574 if (ip6_forward_rt.ro_rt && 575 (ip6_forward_rt.ro_rt->rt_flags & 576 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 577 #ifdef RTF_WASCLONED 578 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 579 #endif 580 #ifdef RTF_CLONED 581 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 582 #endif 583 #if 0 584 /* 585 * The check below is redundant since the comparison of 586 * the destination and the key of the rtentry has 587 * already done through looking up the routing table. 588 */ 589 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 590 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 591 #endif 592 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 593 struct in6_ifaddr *ia6 = 594 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 595 596 /* 597 * record address information into m_aux. 598 */ 599 (void)ip6_setdstifaddr(m, ia6); 600 601 /* 602 * packets to a tentative, duplicated, or somehow invalid 603 * address must not be accepted. 604 */ 605 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 606 /* this address is ready */ 607 ours = 1; 608 deliverifp = ia6->ia_ifp; /* correct? */ 609 /* Count the packet in the ip address stats */ 610 ia6->ia_ifa.if_ipackets++; 611 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 612 goto hbhcheck; 613 } else { 614 /* address is not ready, so discard the packet. */ 615 nd6log((LOG_INFO, 616 "ip6_input: packet to an unready address %s->%s\n", 617 ip6_sprintf(&ip6->ip6_src), 618 ip6_sprintf(&ip6->ip6_dst))); 619 620 goto bad; 621 } 622 } 623 } /* XXX indentation (see above) */ 624 625 /* 626 * FAITH(Firewall Aided Internet Translator) 627 */ 628 if (ip6_keepfaith) { 629 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 630 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 631 /* XXX do we need more sanity checks? */ 632 ours = 1; 633 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 634 goto hbhcheck; 635 } 636 } 637 638 /* 639 * Now there is no reason to process the packet if it's not our own 640 * and we're not a router. 641 */ 642 if (!ip6_forwarding) { 643 ip6stat.ip6s_cantforward++; 644 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 645 goto bad; 646 } 647 648 hbhcheck: 649 /* 650 * record address information into m_aux, if we don't have one yet. 651 * note that we are unable to record it, if the address is not listed 652 * as our interface address (e.g. multicast addresses, addresses 653 * within FAITH prefixes and such). 654 */ 655 if (deliverifp && !ip6_getdstifaddr(m)) { 656 struct in6_ifaddr *ia6; 657 658 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 659 if (ia6) { 660 if (!ip6_setdstifaddr(m, ia6)) { 661 /* 662 * XXX maybe we should drop the packet here, 663 * as we could not provide enough information 664 * to the upper layers. 665 */ 666 } 667 } 668 } 669 670 /* 671 * Process Hop-by-Hop options header if it's contained. 672 * m may be modified in ip6_hopopts_input(). 673 * If a JumboPayload option is included, plen will also be modified. 674 */ 675 plen = (u_int32_t)ntohs(ip6->ip6_plen); 676 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 677 struct ip6_hbh *hbh; 678 679 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 680 #if 0 /*touches NULL pointer*/ 681 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 682 #endif 683 return; /* m have already been freed */ 684 } 685 686 /* adjust pointer */ 687 ip6 = mtod(m, struct ip6_hdr *); 688 689 /* 690 * if the payload length field is 0 and the next header field 691 * indicates Hop-by-Hop Options header, then a Jumbo Payload 692 * option MUST be included. 693 */ 694 if (ip6->ip6_plen == 0 && plen == 0) { 695 /* 696 * Note that if a valid jumbo payload option is 697 * contained, ip6_hoptops_input() must set a valid 698 * (non-zero) payload length to the variable plen. 699 */ 700 ip6stat.ip6s_badoptions++; 701 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 702 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 703 icmp6_error(m, ICMP6_PARAM_PROB, 704 ICMP6_PARAMPROB_HEADER, 705 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 706 return; 707 } 708 #ifndef PULLDOWN_TEST 709 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 710 hbh = (struct ip6_hbh *)(ip6 + 1); 711 #else 712 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 713 sizeof(struct ip6_hbh)); 714 if (hbh == NULL) { 715 ip6stat.ip6s_tooshort++; 716 return; 717 } 718 #endif 719 nxt = hbh->ip6h_nxt; 720 721 /* 722 * accept the packet if a router alert option is included 723 * and we act as an IPv6 router. 724 */ 725 if (rtalert != ~0 && ip6_forwarding) 726 ours = 1; 727 } else 728 nxt = ip6->ip6_nxt; 729 730 /* 731 * Check that the amount of data in the buffers 732 * is as at least much as the IPv6 header would have us expect. 733 * Trim mbufs if longer than we expect. 734 * Drop packet if shorter than we expect. 735 */ 736 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 737 ip6stat.ip6s_tooshort++; 738 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 739 goto bad; 740 } 741 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 742 if (m->m_len == m->m_pkthdr.len) { 743 m->m_len = sizeof(struct ip6_hdr) + plen; 744 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 745 } else 746 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 747 } 748 749 /* 750 * Forward if desirable. 751 */ 752 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 753 /* 754 * If we are acting as a multicast router, all 755 * incoming multicast packets are passed to the 756 * kernel-level multicast forwarding function. 757 * The packet is returned (relatively) intact; if 758 * ip6_mforward() returns a non-zero value, the packet 759 * must be discarded, else it may be accepted below. 760 */ 761 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 762 ip6stat.ip6s_cantforward++; 763 m_freem(m); 764 return; 765 } 766 if (!ours) { 767 m_freem(m); 768 return; 769 } 770 } else if (!ours) { 771 ip6_forward(m, 0); 772 return; 773 } 774 775 ip6 = mtod(m, struct ip6_hdr *); 776 777 /* 778 * Malicious party may be able to use IPv4 mapped addr to confuse 779 * tcp/udp stack and bypass security checks (act as if it was from 780 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 781 * 782 * For SIIT end node behavior, you may want to disable the check. 783 * However, you will become vulnerable to attacks using IPv4 mapped 784 * source. 785 */ 786 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 787 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 788 ip6stat.ip6s_badscope++; 789 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 790 goto bad; 791 } 792 793 /* 794 * Tell launch routine the next header 795 */ 796 ip6stat.ip6s_delivered++; 797 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 798 nest = 0; 799 800 while (nxt != IPPROTO_DONE) { 801 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 802 ip6stat.ip6s_toomanyhdr++; 803 goto bad; 804 } 805 806 /* 807 * protection against faulty packet - there should be 808 * more sanity checks in header chain processing. 809 */ 810 if (m->m_pkthdr.len < off) { 811 ip6stat.ip6s_tooshort++; 812 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 813 goto bad; 814 } 815 816 #if 0 817 /* 818 * do we need to do it for every header? yeah, other 819 * functions can play with it (like re-allocate and copy). 820 */ 821 mhist = ip6_addaux(m); 822 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 823 hist = mtod(mhist, caddr_t) + mhist->m_len; 824 bcopy(&nxt, hist, sizeof(nxt)); 825 mhist->m_len += sizeof(nxt); 826 } else { 827 ip6stat.ip6s_toomanyhdr++; 828 goto bad; 829 } 830 #endif 831 832 #ifdef IPSEC 833 /* 834 * enforce IPsec policy checking if we are seeing last header. 835 * note that we do not visit this with protocols with pcb layer 836 * code - like udp/tcp/raw ip. 837 */ 838 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 839 ipsec6_in_reject(m, NULL)) { 840 ipsec6stat.in_polvio++; 841 goto bad; 842 } 843 #endif 844 845 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 846 } 847 return; 848 bad: 849 m_freem(m); 850 } 851 852 /* 853 * set/grab in6_ifaddr correspond to IPv6 destination address. 854 * XXX backward compatibility wrapper 855 */ 856 static struct ip6aux * 857 ip6_setdstifaddr(m, ia6) 858 struct mbuf *m; 859 struct in6_ifaddr *ia6; 860 { 861 struct ip6aux *n; 862 863 n = ip6_addaux(m); 864 if (n) 865 n->ip6a_dstia6 = ia6; 866 return n; /* NULL if failed to set */ 867 } 868 869 struct in6_ifaddr * 870 ip6_getdstifaddr(m) 871 struct mbuf *m; 872 { 873 struct ip6aux *n; 874 875 n = ip6_findaux(m); 876 if (n) 877 return n->ip6a_dstia6; 878 else 879 return NULL; 880 } 881 882 /* 883 * Hop-by-Hop options header processing. If a valid jumbo payload option is 884 * included, the real payload length will be stored in plenp. 885 */ 886 static int 887 ip6_hopopts_input(plenp, rtalertp, mp, offp) 888 u_int32_t *plenp; 889 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 890 struct mbuf **mp; 891 int *offp; 892 { 893 struct mbuf *m = *mp; 894 int off = *offp, hbhlen; 895 struct ip6_hbh *hbh; 896 u_int8_t *opt; 897 898 /* validation of the length of the header */ 899 #ifndef PULLDOWN_TEST 900 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 901 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 902 hbhlen = (hbh->ip6h_len + 1) << 3; 903 904 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 905 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 906 #else 907 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 908 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 909 if (hbh == NULL) { 910 ip6stat.ip6s_tooshort++; 911 return -1; 912 } 913 hbhlen = (hbh->ip6h_len + 1) << 3; 914 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 915 hbhlen); 916 if (hbh == NULL) { 917 ip6stat.ip6s_tooshort++; 918 return -1; 919 } 920 #endif 921 off += hbhlen; 922 hbhlen -= sizeof(struct ip6_hbh); 923 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 924 925 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 926 hbhlen, rtalertp, plenp) < 0) 927 return(-1); 928 929 *offp = off; 930 *mp = m; 931 return(0); 932 } 933 934 /* 935 * Search header for all Hop-by-hop options and process each option. 936 * This function is separate from ip6_hopopts_input() in order to 937 * handle a case where the sending node itself process its hop-by-hop 938 * options header. In such a case, the function is called from ip6_output(). 939 * 940 * The function assumes that hbh header is located right after the IPv6 header 941 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 942 * opthead + hbhlen is located in continuous memory region. 943 */ 944 int 945 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 946 struct mbuf *m; 947 u_int8_t *opthead; 948 int hbhlen; 949 u_int32_t *rtalertp; 950 u_int32_t *plenp; 951 { 952 struct ip6_hdr *ip6; 953 int optlen = 0; 954 u_int8_t *opt = opthead; 955 u_int16_t rtalert_val; 956 u_int32_t jumboplen; 957 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 958 959 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 960 switch (*opt) { 961 case IP6OPT_PAD1: 962 optlen = 1; 963 break; 964 case IP6OPT_PADN: 965 if (hbhlen < IP6OPT_MINLEN) { 966 ip6stat.ip6s_toosmall++; 967 goto bad; 968 } 969 optlen = *(opt + 1) + 2; 970 break; 971 case IP6OPT_RTALERT: 972 /* XXX may need check for alignment */ 973 if (hbhlen < IP6OPT_RTALERT_LEN) { 974 ip6stat.ip6s_toosmall++; 975 goto bad; 976 } 977 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 978 /* XXX stat */ 979 icmp6_error(m, ICMP6_PARAM_PROB, 980 ICMP6_PARAMPROB_HEADER, 981 erroff + opt + 1 - opthead); 982 return(-1); 983 } 984 optlen = IP6OPT_RTALERT_LEN; 985 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 986 *rtalertp = ntohs(rtalert_val); 987 break; 988 case IP6OPT_JUMBO: 989 /* XXX may need check for alignment */ 990 if (hbhlen < IP6OPT_JUMBO_LEN) { 991 ip6stat.ip6s_toosmall++; 992 goto bad; 993 } 994 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 995 /* XXX stat */ 996 icmp6_error(m, ICMP6_PARAM_PROB, 997 ICMP6_PARAMPROB_HEADER, 998 erroff + opt + 1 - opthead); 999 return(-1); 1000 } 1001 optlen = IP6OPT_JUMBO_LEN; 1002 1003 /* 1004 * IPv6 packets that have non 0 payload length 1005 * must not contain a jumbo payload option. 1006 */ 1007 ip6 = mtod(m, struct ip6_hdr *); 1008 if (ip6->ip6_plen) { 1009 ip6stat.ip6s_badoptions++; 1010 icmp6_error(m, ICMP6_PARAM_PROB, 1011 ICMP6_PARAMPROB_HEADER, 1012 erroff + opt - opthead); 1013 return(-1); 1014 } 1015 1016 /* 1017 * We may see jumbolen in unaligned location, so 1018 * we'd need to perform bcopy(). 1019 */ 1020 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1021 jumboplen = (u_int32_t)htonl(jumboplen); 1022 1023 #if 1 1024 /* 1025 * if there are multiple jumbo payload options, 1026 * *plenp will be non-zero and the packet will be 1027 * rejected. 1028 * the behavior may need some debate in ipngwg - 1029 * multiple options does not make sense, however, 1030 * there's no explicit mention in specification. 1031 */ 1032 if (*plenp != 0) { 1033 ip6stat.ip6s_badoptions++; 1034 icmp6_error(m, ICMP6_PARAM_PROB, 1035 ICMP6_PARAMPROB_HEADER, 1036 erroff + opt + 2 - opthead); 1037 return(-1); 1038 } 1039 #endif 1040 1041 /* 1042 * jumbo payload length must be larger than 65535. 1043 */ 1044 if (jumboplen <= IPV6_MAXPACKET) { 1045 ip6stat.ip6s_badoptions++; 1046 icmp6_error(m, ICMP6_PARAM_PROB, 1047 ICMP6_PARAMPROB_HEADER, 1048 erroff + opt + 2 - opthead); 1049 return(-1); 1050 } 1051 *plenp = jumboplen; 1052 1053 break; 1054 default: /* unknown option */ 1055 if (hbhlen < IP6OPT_MINLEN) { 1056 ip6stat.ip6s_toosmall++; 1057 goto bad; 1058 } 1059 optlen = ip6_unknown_opt(opt, m, 1060 erroff + opt - opthead); 1061 if (optlen == -1) 1062 return(-1); 1063 optlen += 2; 1064 break; 1065 } 1066 } 1067 1068 return(0); 1069 1070 bad: 1071 m_freem(m); 1072 return(-1); 1073 } 1074 1075 /* 1076 * Unknown option processing. 1077 * The third argument `off' is the offset from the IPv6 header to the option, 1078 * which is necessary if the IPv6 header the and option header and IPv6 header 1079 * is not continuous in order to return an ICMPv6 error. 1080 */ 1081 int 1082 ip6_unknown_opt(optp, m, off) 1083 u_int8_t *optp; 1084 struct mbuf *m; 1085 int off; 1086 { 1087 struct ip6_hdr *ip6; 1088 1089 switch (IP6OPT_TYPE(*optp)) { 1090 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1091 return((int)*(optp + 1)); 1092 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1093 m_freem(m); 1094 return(-1); 1095 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1096 ip6stat.ip6s_badoptions++; 1097 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1098 return(-1); 1099 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1100 ip6stat.ip6s_badoptions++; 1101 ip6 = mtod(m, struct ip6_hdr *); 1102 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1103 (m->m_flags & (M_BCAST|M_MCAST))) 1104 m_freem(m); 1105 else 1106 icmp6_error(m, ICMP6_PARAM_PROB, 1107 ICMP6_PARAMPROB_OPTION, off); 1108 return(-1); 1109 } 1110 1111 m_freem(m); /* XXX: NOTREACHED */ 1112 return(-1); 1113 } 1114 1115 /* 1116 * Create the "control" list for this pcb. 1117 * The function will not modify mbuf chain at all. 1118 * 1119 * with KAME mbuf chain restriction: 1120 * The routine will be called from upper layer handlers like tcp6_input(). 1121 * Thus the routine assumes that the caller (tcp6_input) have already 1122 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1123 * very first mbuf on the mbuf chain. 1124 */ 1125 void 1126 ip6_savecontrol(in6p, mp, ip6, m) 1127 struct inpcb *in6p; 1128 struct mbuf **mp; 1129 struct ip6_hdr *ip6; 1130 struct mbuf *m; 1131 { 1132 int rthdr_exist = 0; 1133 1134 #ifdef SO_TIMESTAMP 1135 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1136 struct timeval tv; 1137 1138 microtime(&tv); 1139 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1140 SCM_TIMESTAMP, SOL_SOCKET); 1141 if (*mp) { 1142 mp = &(*mp)->m_next; 1143 } 1144 } 1145 #endif 1146 1147 /* RFC 2292 sec. 5 */ 1148 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1149 struct in6_pktinfo pi6; 1150 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1151 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1152 pi6.ipi6_addr.s6_addr16[1] = 0; 1153 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1154 ? m->m_pkthdr.rcvif->if_index 1155 : 0; 1156 *mp = sbcreatecontrol((caddr_t) &pi6, 1157 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1158 IPPROTO_IPV6); 1159 if (*mp) 1160 mp = &(*mp)->m_next; 1161 } 1162 1163 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1164 int hlim = ip6->ip6_hlim & 0xff; 1165 *mp = sbcreatecontrol((caddr_t) &hlim, 1166 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1167 if (*mp) 1168 mp = &(*mp)->m_next; 1169 } 1170 1171 /* 1172 * IPV6_HOPOPTS socket option. Recall that we required super-user 1173 * privilege for the option (see ip6_ctloutput), but it might be too 1174 * strict, since there might be some hop-by-hop options which can be 1175 * returned to normal user. 1176 * See also RFC 2292 section 6. 1177 */ 1178 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) { 1179 /* 1180 * Check if a hop-by-hop options header is contatined in the 1181 * received packet, and if so, store the options as ancillary 1182 * data. Note that a hop-by-hop options header must be 1183 * just after the IPv6 header, which fact is assured through 1184 * the IPv6 input processing. 1185 */ 1186 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1187 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1188 struct ip6_hbh *hbh; 1189 int hbhlen = 0; 1190 #ifdef PULLDOWN_TEST 1191 struct mbuf *ext; 1192 #endif 1193 1194 #ifndef PULLDOWN_TEST 1195 hbh = (struct ip6_hbh *)(ip6 + 1); 1196 hbhlen = (hbh->ip6h_len + 1) << 3; 1197 #else 1198 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1199 ip6->ip6_nxt); 1200 if (ext == NULL) { 1201 ip6stat.ip6s_tooshort++; 1202 return; 1203 } 1204 hbh = mtod(ext, struct ip6_hbh *); 1205 hbhlen = (hbh->ip6h_len + 1) << 3; 1206 if (hbhlen != ext->m_len) { 1207 m_freem(ext); 1208 ip6stat.ip6s_tooshort++; 1209 return; 1210 } 1211 #endif 1212 1213 /* 1214 * XXX: We copy whole the header even if a jumbo 1215 * payload option is included, which option is to 1216 * be removed before returning in the RFC 2292. 1217 * Note: this constraint is removed in 2292bis. 1218 */ 1219 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1220 IPV6_HOPOPTS, IPPROTO_IPV6); 1221 if (*mp) 1222 mp = &(*mp)->m_next; 1223 #ifdef PULLDOWN_TEST 1224 m_freem(ext); 1225 #endif 1226 } 1227 } 1228 1229 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1230 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1231 int proto, off, nxt; 1232 1233 /* 1234 * go through the header chain to see if a routing header is 1235 * contained in the packet. We need this information to store 1236 * destination options headers (if any) properly. 1237 * XXX: performance issue. We should record this info when 1238 * processing extension headers in incoming routine. 1239 * (todo) use m_aux? 1240 */ 1241 proto = IPPROTO_IPV6; 1242 off = 0; 1243 nxt = -1; 1244 while (1) { 1245 int newoff; 1246 1247 newoff = ip6_nexthdr(m, off, proto, &nxt); 1248 if (newoff < 0) 1249 break; 1250 if (newoff < off) /* invalid, check for safety */ 1251 break; 1252 if ((proto = nxt) == IPPROTO_ROUTING) { 1253 rthdr_exist = 1; 1254 break; 1255 } 1256 off = newoff; 1257 } 1258 } 1259 1260 if ((in6p->in6p_flags & 1261 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1262 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1263 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1264 1265 /* 1266 * Search for destination options headers or routing 1267 * header(s) through the header chain, and stores each 1268 * header as ancillary data. 1269 * Note that the order of the headers remains in 1270 * the chain of ancillary data. 1271 */ 1272 while (1) { /* is explicit loop prevention necessary? */ 1273 struct ip6_ext *ip6e = NULL; 1274 int elen; 1275 #ifdef PULLDOWN_TEST 1276 struct mbuf *ext = NULL; 1277 #endif 1278 1279 /* 1280 * if it is not an extension header, don't try to 1281 * pull it from the chain. 1282 */ 1283 switch (nxt) { 1284 case IPPROTO_DSTOPTS: 1285 case IPPROTO_ROUTING: 1286 case IPPROTO_HOPOPTS: 1287 case IPPROTO_AH: /* is it possible? */ 1288 break; 1289 default: 1290 goto loopend; 1291 } 1292 1293 #ifndef PULLDOWN_TEST 1294 if (off + sizeof(*ip6e) > m->m_len) 1295 goto loopend; 1296 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1297 if (nxt == IPPROTO_AH) 1298 elen = (ip6e->ip6e_len + 2) << 2; 1299 else 1300 elen = (ip6e->ip6e_len + 1) << 3; 1301 if (off + elen > m->m_len) 1302 goto loopend; 1303 #else 1304 ext = ip6_pullexthdr(m, off, nxt); 1305 if (ext == NULL) { 1306 ip6stat.ip6s_tooshort++; 1307 return; 1308 } 1309 ip6e = mtod(ext, struct ip6_ext *); 1310 if (nxt == IPPROTO_AH) 1311 elen = (ip6e->ip6e_len + 2) << 2; 1312 else 1313 elen = (ip6e->ip6e_len + 1) << 3; 1314 if (elen != ext->m_len) { 1315 m_freem(ext); 1316 ip6stat.ip6s_tooshort++; 1317 return; 1318 } 1319 #endif 1320 1321 switch (nxt) { 1322 case IPPROTO_DSTOPTS: 1323 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1324 break; 1325 1326 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1327 IPV6_DSTOPTS, 1328 IPPROTO_IPV6); 1329 if (*mp) 1330 mp = &(*mp)->m_next; 1331 break; 1332 case IPPROTO_ROUTING: 1333 if (!in6p->in6p_flags & IN6P_RTHDR) 1334 break; 1335 1336 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1337 IPV6_RTHDR, 1338 IPPROTO_IPV6); 1339 if (*mp) 1340 mp = &(*mp)->m_next; 1341 break; 1342 case IPPROTO_HOPOPTS: 1343 case IPPROTO_AH: /* is it possible? */ 1344 break; 1345 1346 default: 1347 /* 1348 * other cases have been filtered in the above. 1349 * none will visit this case. here we supply 1350 * the code just in case (nxt overwritten or 1351 * other cases). 1352 */ 1353 #ifdef PULLDOWN_TEST 1354 m_freem(ext); 1355 #endif 1356 goto loopend; 1357 1358 } 1359 1360 /* proceed with the next header. */ 1361 off += elen; 1362 nxt = ip6e->ip6e_nxt; 1363 ip6e = NULL; 1364 #ifdef PULLDOWN_TEST 1365 m_freem(ext); 1366 ext = NULL; 1367 #endif 1368 } 1369 loopend: 1370 ; 1371 } 1372 1373 } 1374 1375 #ifdef PULLDOWN_TEST 1376 /* 1377 * pull single extension header from mbuf chain. returns single mbuf that 1378 * contains the result, or NULL on error. 1379 */ 1380 static struct mbuf * 1381 ip6_pullexthdr(m, off, nxt) 1382 struct mbuf *m; 1383 size_t off; 1384 int nxt; 1385 { 1386 struct ip6_ext ip6e; 1387 size_t elen; 1388 struct mbuf *n; 1389 1390 #ifdef DIAGNOSTIC 1391 switch (nxt) { 1392 case IPPROTO_DSTOPTS: 1393 case IPPROTO_ROUTING: 1394 case IPPROTO_HOPOPTS: 1395 case IPPROTO_AH: /* is it possible? */ 1396 break; 1397 default: 1398 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1399 } 1400 #endif 1401 1402 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1403 if (nxt == IPPROTO_AH) 1404 elen = (ip6e.ip6e_len + 2) << 2; 1405 else 1406 elen = (ip6e.ip6e_len + 1) << 3; 1407 1408 MGET(n, M_DONTWAIT, MT_DATA); 1409 if (n && elen >= MLEN) { 1410 MCLGET(n, M_DONTWAIT); 1411 if ((n->m_flags & M_EXT) == 0) { 1412 m_free(n); 1413 n = NULL; 1414 } 1415 } 1416 if (!n) 1417 return NULL; 1418 1419 n->m_len = 0; 1420 if (elen >= M_TRAILINGSPACE(n)) { 1421 m_free(n); 1422 return NULL; 1423 } 1424 1425 m_copydata(m, off, elen, mtod(n, caddr_t)); 1426 n->m_len = elen; 1427 return n; 1428 } 1429 #endif 1430 1431 /* 1432 * Get pointer to the previous header followed by the header 1433 * currently processed. 1434 * XXX: This function supposes that 1435 * M includes all headers, 1436 * the next header field and the header length field of each header 1437 * are valid, and 1438 * the sum of each header length equals to OFF. 1439 * Because of these assumptions, this function must be called very 1440 * carefully. Moreover, it will not be used in the near future when 1441 * we develop `neater' mechanism to process extension headers. 1442 */ 1443 char * 1444 ip6_get_prevhdr(m, off) 1445 struct mbuf *m; 1446 int off; 1447 { 1448 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1449 1450 if (off == sizeof(struct ip6_hdr)) 1451 return(&ip6->ip6_nxt); 1452 else { 1453 int len, nxt; 1454 struct ip6_ext *ip6e = NULL; 1455 1456 nxt = ip6->ip6_nxt; 1457 len = sizeof(struct ip6_hdr); 1458 while (len < off) { 1459 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1460 1461 switch (nxt) { 1462 case IPPROTO_FRAGMENT: 1463 len += sizeof(struct ip6_frag); 1464 break; 1465 case IPPROTO_AH: 1466 len += (ip6e->ip6e_len + 2) << 2; 1467 break; 1468 default: 1469 len += (ip6e->ip6e_len + 1) << 3; 1470 break; 1471 } 1472 nxt = ip6e->ip6e_nxt; 1473 } 1474 if (ip6e) 1475 return(&ip6e->ip6e_nxt); 1476 else 1477 return NULL; 1478 } 1479 } 1480 1481 /* 1482 * get next header offset. m will be retained. 1483 */ 1484 int 1485 ip6_nexthdr(m, off, proto, nxtp) 1486 struct mbuf *m; 1487 int off; 1488 int proto; 1489 int *nxtp; 1490 { 1491 struct ip6_hdr ip6; 1492 struct ip6_ext ip6e; 1493 struct ip6_frag fh; 1494 1495 /* just in case */ 1496 if (m == NULL) 1497 panic("ip6_nexthdr: m == NULL"); 1498 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1499 return -1; 1500 1501 switch (proto) { 1502 case IPPROTO_IPV6: 1503 if (m->m_pkthdr.len < off + sizeof(ip6)) 1504 return -1; 1505 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1506 if (nxtp) 1507 *nxtp = ip6.ip6_nxt; 1508 off += sizeof(ip6); 1509 return off; 1510 1511 case IPPROTO_FRAGMENT: 1512 /* 1513 * terminate parsing if it is not the first fragment, 1514 * it does not make sense to parse through it. 1515 */ 1516 if (m->m_pkthdr.len < off + sizeof(fh)) 1517 return -1; 1518 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1519 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1520 return -1; 1521 if (nxtp) 1522 *nxtp = fh.ip6f_nxt; 1523 off += sizeof(struct ip6_frag); 1524 return off; 1525 1526 case IPPROTO_AH: 1527 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1528 return -1; 1529 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1530 if (nxtp) 1531 *nxtp = ip6e.ip6e_nxt; 1532 off += (ip6e.ip6e_len + 2) << 2; 1533 return off; 1534 1535 case IPPROTO_HOPOPTS: 1536 case IPPROTO_ROUTING: 1537 case IPPROTO_DSTOPTS: 1538 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1539 return -1; 1540 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1541 if (nxtp) 1542 *nxtp = ip6e.ip6e_nxt; 1543 off += (ip6e.ip6e_len + 1) << 3; 1544 return off; 1545 1546 case IPPROTO_NONE: 1547 case IPPROTO_ESP: 1548 case IPPROTO_IPCOMP: 1549 /* give up */ 1550 return -1; 1551 1552 default: 1553 return -1; 1554 } 1555 1556 return -1; 1557 } 1558 1559 /* 1560 * get offset for the last header in the chain. m will be kept untainted. 1561 */ 1562 int 1563 ip6_lasthdr(m, off, proto, nxtp) 1564 struct mbuf *m; 1565 int off; 1566 int proto; 1567 int *nxtp; 1568 { 1569 int newoff; 1570 int nxt; 1571 1572 if (!nxtp) { 1573 nxt = -1; 1574 nxtp = &nxt; 1575 } 1576 while (1) { 1577 newoff = ip6_nexthdr(m, off, proto, nxtp); 1578 if (newoff < 0) 1579 return off; 1580 else if (newoff < off) 1581 return -1; /* invalid */ 1582 else if (newoff == off) 1583 return newoff; 1584 1585 off = newoff; 1586 proto = *nxtp; 1587 } 1588 } 1589 1590 struct ip6aux * 1591 ip6_addaux(m) 1592 struct mbuf *m; 1593 { 1594 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1595 if (!tag) { 1596 tag = m_tag_get(PACKET_TAG_IPV6_INPUT, 1597 sizeof (struct ip6aux), 1598 M_NOWAIT); 1599 if (tag) 1600 m_tag_prepend(m, tag); 1601 } 1602 if (tag) 1603 bzero(tag+1, sizeof (struct ip6aux)); 1604 return tag ? (struct ip6aux*)(tag+1) : NULL; 1605 } 1606 1607 struct ip6aux * 1608 ip6_findaux(m) 1609 struct mbuf *m; 1610 { 1611 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1612 return tag ? (struct ip6aux*)(tag+1) : NULL; 1613 } 1614 1615 void 1616 ip6_delaux(m) 1617 struct mbuf *m; 1618 { 1619 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1620 if (tag) 1621 m_tag_delete(m, tag); 1622 } 1623 1624 /* 1625 * System control for IP6 1626 */ 1627 1628 u_char inet6ctlerrmap[PRC_NCMDS] = { 1629 0, 0, 0, 0, 1630 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1631 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1632 EMSGSIZE, EHOSTUNREACH, 0, 0, 1633 0, 0, 0, 0, 1634 ENOPROTOOPT 1635 };
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