ip6_input.c revision 1.58
1 /* $NetBSD: ip6_input.c,v 1.58 2002/09/11 02:41:25 itojun Exp $ */ 2 /* $KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 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 <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: ip6_input.c,v 1.58 2002/09/11 02:41:25 itojun Exp $"); 70 71 #include "opt_inet.h" 72 #include "opt_ipsec.h" 73 #include "opt_pfil_hooks.h" 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/malloc.h> 78 #include <sys/mbuf.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 #include <sys/proc.h> 88 #include <sys/sysctl.h> 89 90 #include <net/if.h> 91 #include <net/if_types.h> 92 #include <net/if_dl.h> 93 #include <net/route.h> 94 #include <net/netisr.h> 95 #ifdef PFIL_HOOKS 96 #include <net/pfil.h> 97 #endif 98 99 #include <netinet/in.h> 100 #include <netinet/in_systm.h> 101 #ifdef INET 102 #include <netinet/ip.h> 103 #include <netinet/ip_icmp.h> 104 #endif /* INET */ 105 #include <netinet/ip6.h> 106 #include <netinet6/in6_var.h> 107 #include <netinet6/ip6_var.h> 108 #include <netinet6/in6_pcb.h> 109 #include <netinet/icmp6.h> 110 #include <netinet6/in6_ifattach.h> 111 #include <netinet6/nd6.h> 112 113 #ifdef IPSEC 114 #include <netinet6/ipsec.h> 115 #endif 116 117 #include <netinet6/ip6protosw.h> 118 119 /* we need it for NLOOP. */ 120 #include "loop.h" 121 #include "faith.h" 122 #include "gif.h" 123 #include "bpfilter.h" 124 125 #if NGIF > 0 126 #include <netinet6/in6_gif.h> 127 #endif 128 129 #include <net/net_osdep.h> 130 131 extern struct domain inet6domain; 132 133 u_char ip6_protox[IPPROTO_MAX]; 134 static int ip6qmaxlen = IFQ_MAXLEN; 135 struct in6_ifaddr *in6_ifaddr; 136 struct ifqueue ip6intrq; 137 138 extern struct ifnet loif[NLOOP]; 139 int ip6_forward_srcrt; /* XXX */ 140 int ip6_sourcecheck; /* XXX */ 141 int ip6_sourcecheck_interval; /* XXX */ 142 143 #ifdef PFIL_HOOKS 144 struct pfil_head inet6_pfil_hook; 145 #endif 146 147 struct ip6stat ip6stat; 148 149 static void ip6_init2 __P((void *)); 150 151 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 152 153 /* 154 * IP6 initialization: fill in IP6 protocol switch table. 155 * All protocols not implemented in kernel go to raw IP6 protocol handler. 156 */ 157 void 158 ip6_init() 159 { 160 struct ip6protosw *pr; 161 int i; 162 163 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 164 if (pr == 0) 165 panic("ip6_init"); 166 for (i = 0; i < IPPROTO_MAX; i++) 167 ip6_protox[i] = pr - inet6sw; 168 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 169 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 170 if (pr->pr_domain->dom_family == PF_INET6 && 171 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 172 ip6_protox[pr->pr_protocol] = pr - inet6sw; 173 ip6intrq.ifq_maxlen = ip6qmaxlen; 174 nd6_init(); 175 frag6_init(); 176 ip6_flow_seq = arc4random(); 177 178 ip6_init2((void *)0); 179 180 #ifdef PFIL_HOOKS 181 /* Register our Packet Filter hook. */ 182 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 183 inet6_pfil_hook.ph_af = AF_INET6; 184 i = pfil_head_register(&inet6_pfil_hook); 185 if (i != 0) 186 printf("ip6_init: WARNING: unable to register pfil hook, " 187 "error %d\n", i); 188 #endif /* PFIL_HOOKS */ 189 } 190 191 static void 192 ip6_init2(dummy) 193 void *dummy; 194 { 195 196 /* nd6_timer_init */ 197 callout_init(&nd6_timer_ch); 198 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 199 } 200 201 /* 202 * IP6 input interrupt handling. Just pass the packet to ip6_input. 203 */ 204 void 205 ip6intr() 206 { 207 int s; 208 struct mbuf *m; 209 210 for (;;) { 211 s = splnet(); 212 IF_DEQUEUE(&ip6intrq, m); 213 splx(s); 214 if (m == 0) 215 return; 216 ip6_input(m); 217 } 218 } 219 220 extern struct route_in6 ip6_forward_rt; 221 222 void 223 ip6_input(m) 224 struct mbuf *m; 225 { 226 struct ip6_hdr *ip6; 227 int off = sizeof(struct ip6_hdr), nest; 228 u_int32_t plen; 229 u_int32_t rtalert = ~0; 230 int nxt, ours = 0; 231 struct ifnet *deliverifp = NULL; 232 233 #ifdef IPSEC 234 /* 235 * should the inner packet be considered authentic? 236 * see comment in ah4_input(). 237 */ 238 m->m_flags &= ~M_AUTHIPHDR; 239 m->m_flags &= ~M_AUTHIPDGM; 240 #endif 241 242 /* 243 * mbuf statistics 244 */ 245 if (m->m_flags & M_EXT) { 246 if (m->m_next) 247 ip6stat.ip6s_mext2m++; 248 else 249 ip6stat.ip6s_mext1++; 250 } else { 251 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 252 if (m->m_next) { 253 if (m->m_flags & M_LOOP) { 254 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 255 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 256 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 257 else 258 ip6stat.ip6s_m2m[0]++; 259 } else 260 ip6stat.ip6s_m1++; 261 #undef M2MMAX 262 } 263 264 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 265 ip6stat.ip6s_total++; 266 267 #ifndef PULLDOWN_TEST 268 /* XXX is the line really necessary? */ 269 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 270 #endif 271 272 /* 273 * If the IPv6 header is not aligned, slurp it up into a new 274 * mbuf with space for link headers, in the event we forward 275 * it. OTherwise, if it is aligned, make sure the entire base 276 * IPv6 header is in the first mbuf of the chain. 277 */ 278 if (IP6_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) { 279 struct ifnet *inifp = m->m_pkthdr.rcvif; 280 if ((m = m_copyup(m, sizeof(struct ip6_hdr), 281 (max_linkhdr + 3) & ~3)) == NULL) { 282 /* XXXJRT new stat, please */ 283 ip6stat.ip6s_toosmall++; 284 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 285 return; 286 } 287 } else if (__predict_false(m->m_len < sizeof(struct ip6_hdr))) { 288 struct ifnet *inifp = m->m_pkthdr.rcvif; 289 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 290 ip6stat.ip6s_toosmall++; 291 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 292 return; 293 } 294 } 295 296 ip6 = mtod(m, struct ip6_hdr *); 297 298 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 299 ip6stat.ip6s_badvers++; 300 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 301 goto bad; 302 } 303 304 #ifdef PFIL_HOOKS 305 /* 306 * Run through list of hooks for input packets. If there are any 307 * filters which require that additional packets in the flow are 308 * not fast-forwarded, they must clear the M_CANFASTFWD flag. 309 * Note that filters must _never_ set this flag, as another filter 310 * in the list may have previously cleared it. 311 */ 312 /* 313 * let ipfilter look at packet on the wire, 314 * not the decapsulated packet. 315 */ 316 #ifdef IPSEC 317 if (!ipsec_getnhist(m)) 318 #else 319 if (1) 320 #endif 321 { 322 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, 323 PFIL_IN) != 0) 324 return; 325 if (m == NULL) 326 return; 327 ip6 = mtod(m, struct ip6_hdr *); 328 } 329 #endif /* PFIL_HOOKS */ 330 331 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 332 333 #ifdef ALTQ 334 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 335 /* packet is dropped by traffic conditioner */ 336 return; 337 } 338 #endif 339 340 /* 341 * Check against address spoofing/corruption. 342 */ 343 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 344 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 345 /* 346 * XXX: "badscope" is not very suitable for a multicast source. 347 */ 348 ip6stat.ip6s_badscope++; 349 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 350 goto bad; 351 } 352 /* 353 * The following check is not documented in specs. A malicious 354 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 355 * and bypass security checks (act as if it was from 127.0.0.1 by using 356 * IPv6 src ::ffff:127.0.0.1). Be cautious. 357 * 358 * This check chokes if we are in an SIIT cloud. As none of BSDs 359 * support IPv4-less kernel compilation, we cannot support SIIT 360 * environment at all. So, it makes more sense for us to reject any 361 * malicious packets for non-SIIT environment, than try to do a 362 * partial support for SIIT environment. 363 */ 364 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 365 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 366 ip6stat.ip6s_badscope++; 367 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 368 goto bad; 369 } 370 #if 0 371 /* 372 * Reject packets with IPv4 compatible addresses (auto tunnel). 373 * 374 * The code forbids auto tunnel relay case in RFC1933 (the check is 375 * stronger than RFC1933). We may want to re-enable it if mech-xx 376 * is revised to forbid relaying case. 377 */ 378 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 379 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 380 ip6stat.ip6s_badscope++; 381 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 382 goto bad; 383 } 384 #endif 385 386 if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 387 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) { 388 if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) { 389 ours = 1; 390 deliverifp = m->m_pkthdr.rcvif; 391 goto hbhcheck; 392 } else { 393 ip6stat.ip6s_badscope++; 394 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 395 goto bad; 396 } 397 } 398 399 /* drop packets if interface ID portion is already filled */ 400 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 401 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 402 ip6->ip6_src.s6_addr16[1]) { 403 ip6stat.ip6s_badscope++; 404 goto bad; 405 } 406 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 407 ip6->ip6_dst.s6_addr16[1]) { 408 ip6stat.ip6s_badscope++; 409 goto bad; 410 } 411 } 412 413 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 414 ip6->ip6_src.s6_addr16[1] 415 = htons(m->m_pkthdr.rcvif->if_index); 416 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 417 ip6->ip6_dst.s6_addr16[1] 418 = htons(m->m_pkthdr.rcvif->if_index); 419 420 /* 421 * We use rt->rt_ifp to determine if the address is ours or not. 422 * If rt_ifp is lo0, the address is ours. 423 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 424 * so any address under fe80::%lo0/64 will be mistakenly considered 425 * local. The special case is supplied to handle the case properly 426 * by actually looking at interface addresses 427 * (using in6ifa_ifpwithaddr). 428 */ 429 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 430 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 431 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 432 icmp6_error(m, ICMP6_DST_UNREACH, 433 ICMP6_DST_UNREACH_ADDR, 0); 434 /* m is already freed */ 435 return; 436 } 437 438 ours = 1; 439 deliverifp = m->m_pkthdr.rcvif; 440 goto hbhcheck; 441 } 442 443 /* 444 * Multicast check 445 */ 446 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 447 struct in6_multi *in6m = 0; 448 449 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 450 /* 451 * See if we belong to the destination multicast group on the 452 * arrival interface. 453 */ 454 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 455 if (in6m) 456 ours = 1; 457 else if (!ip6_mrouter) { 458 ip6stat.ip6s_notmember++; 459 ip6stat.ip6s_cantforward++; 460 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 461 goto bad; 462 } 463 deliverifp = m->m_pkthdr.rcvif; 464 goto hbhcheck; 465 } 466 467 /* 468 * Unicast check 469 */ 470 if (ip6_forward_rt.ro_rt != NULL && 471 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 472 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 473 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 474 ip6stat.ip6s_forward_cachehit++; 475 else { 476 struct sockaddr_in6 *dst6; 477 478 if (ip6_forward_rt.ro_rt) { 479 /* route is down or destination is different */ 480 ip6stat.ip6s_forward_cachemiss++; 481 RTFREE(ip6_forward_rt.ro_rt); 482 ip6_forward_rt.ro_rt = 0; 483 } 484 485 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 486 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 487 dst6->sin6_len = sizeof(struct sockaddr_in6); 488 dst6->sin6_family = AF_INET6; 489 dst6->sin6_addr = ip6->ip6_dst; 490 491 rtalloc((struct route *)&ip6_forward_rt); 492 } 493 494 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 495 496 /* 497 * Accept the packet if the forwarding interface to the destination 498 * according to the routing table is the loopback interface, 499 * unless the associated route has a gateway. 500 * Note that this approach causes to accept a packet if there is a 501 * route to the loopback interface for the destination of the packet. 502 * But we think it's even useful in some situations, e.g. when using 503 * a special daemon which wants to intercept the packet. 504 */ 505 if (ip6_forward_rt.ro_rt && 506 (ip6_forward_rt.ro_rt->rt_flags & 507 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 508 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 509 #if 0 510 /* 511 * The check below is redundant since the comparison of 512 * the destination and the key of the rtentry has 513 * already done through looking up the routing table. 514 */ 515 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 516 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && 517 #endif 518 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 519 struct in6_ifaddr *ia6 = 520 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 521 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 522 m->m_flags |= M_ANYCAST6; 523 /* 524 * packets to a tentative, duplicated, or somehow invalid 525 * address must not be accepted. 526 */ 527 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 528 /* this address is ready */ 529 ours = 1; 530 deliverifp = ia6->ia_ifp; /* correct? */ 531 goto hbhcheck; 532 } else { 533 /* address is not ready, so discard the packet. */ 534 nd6log((LOG_INFO, 535 "ip6_input: packet to an unready address %s->%s\n", 536 ip6_sprintf(&ip6->ip6_src), 537 ip6_sprintf(&ip6->ip6_dst))); 538 539 goto bad; 540 } 541 } 542 543 /* 544 * FAITH (Firewall Aided Internet Translator) 545 */ 546 #if defined(NFAITH) && 0 < NFAITH 547 if (ip6_keepfaith) { 548 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 549 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 550 /* XXX do we need more sanity checks? */ 551 ours = 1; 552 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 553 goto hbhcheck; 554 } 555 } 556 #endif 557 558 #if 0 559 { 560 /* 561 * Last resort: check in6_ifaddr for incoming interface. 562 * The code is here until I update the "goto ours hack" code above 563 * working right. 564 */ 565 struct ifaddr *ifa; 566 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 567 ifa; 568 ifa = ifa->ifa_list.tqe_next) { 569 if (ifa->ifa_addr == NULL) 570 continue; /* just for safety */ 571 if (ifa->ifa_addr->sa_family != AF_INET6) 572 continue; 573 if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) { 574 ours = 1; 575 deliverifp = ifa->ifa_ifp; 576 goto hbhcheck; 577 } 578 } 579 } 580 #endif 581 582 /* 583 * Now there is no reason to process the packet if it's not our own 584 * and we're not a router. 585 */ 586 if (!ip6_forwarding) { 587 ip6stat.ip6s_cantforward++; 588 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 589 goto bad; 590 } 591 592 hbhcheck: 593 /* 594 * Process Hop-by-Hop options header if it's contained. 595 * m may be modified in ip6_hopopts_input(). 596 * If a JumboPayload option is included, plen will also be modified. 597 */ 598 plen = (u_int32_t)ntohs(ip6->ip6_plen); 599 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 600 struct ip6_hbh *hbh; 601 602 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 603 #if 0 /*touches NULL pointer*/ 604 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 605 #endif 606 return; /* m have already been freed */ 607 } 608 609 /* adjust pointer */ 610 ip6 = mtod(m, struct ip6_hdr *); 611 612 /* 613 * if the payload length field is 0 and the next header field 614 * indicates Hop-by-Hop Options header, then a Jumbo Payload 615 * option MUST be included. 616 */ 617 if (ip6->ip6_plen == 0 && plen == 0) { 618 /* 619 * Note that if a valid jumbo payload option is 620 * contained, ip6_hoptops_input() must set a valid 621 * (non-zero) payload length to the variable plen. 622 */ 623 ip6stat.ip6s_badoptions++; 624 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 625 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 626 icmp6_error(m, ICMP6_PARAM_PROB, 627 ICMP6_PARAMPROB_HEADER, 628 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 629 return; 630 } 631 #ifndef PULLDOWN_TEST 632 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 633 hbh = (struct ip6_hbh *)(ip6 + 1); 634 #else 635 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 636 sizeof(struct ip6_hbh)); 637 if (hbh == NULL) { 638 ip6stat.ip6s_tooshort++; 639 return; 640 } 641 #endif 642 KASSERT(IP6_HDR_ALIGNED_P(hbh)); 643 nxt = hbh->ip6h_nxt; 644 645 /* 646 * accept the packet if a router alert option is included 647 * and we act as an IPv6 router. 648 */ 649 if (rtalert != ~0 && ip6_forwarding) 650 ours = 1; 651 } else 652 nxt = ip6->ip6_nxt; 653 654 /* 655 * Check that the amount of data in the buffers 656 * is as at least much as the IPv6 header would have us expect. 657 * Trim mbufs if longer than we expect. 658 * Drop packet if shorter than we expect. 659 */ 660 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 661 ip6stat.ip6s_tooshort++; 662 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 663 goto bad; 664 } 665 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 666 if (m->m_len == m->m_pkthdr.len) { 667 m->m_len = sizeof(struct ip6_hdr) + plen; 668 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 669 } else 670 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 671 } 672 673 /* 674 * Forward if desirable. 675 */ 676 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 677 /* 678 * If we are acting as a multicast router, all 679 * incoming multicast packets are passed to the 680 * kernel-level multicast forwarding function. 681 * The packet is returned (relatively) intact; if 682 * ip6_mforward() returns a non-zero value, the packet 683 * must be discarded, else it may be accepted below. 684 */ 685 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 686 ip6stat.ip6s_cantforward++; 687 m_freem(m); 688 return; 689 } 690 if (!ours) { 691 m_freem(m); 692 return; 693 } 694 } else if (!ours) { 695 ip6_forward(m, 0); 696 return; 697 } 698 699 ip6 = mtod(m, struct ip6_hdr *); 700 701 /* 702 * Malicious party may be able to use IPv4 mapped addr to confuse 703 * tcp/udp stack and bypass security checks (act as if it was from 704 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 705 * 706 * For SIIT end node behavior, you may want to disable the check. 707 * However, you will become vulnerable to attacks using IPv4 mapped 708 * source. 709 */ 710 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 711 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 712 ip6stat.ip6s_badscope++; 713 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 714 goto bad; 715 } 716 717 /* 718 * Tell launch routine the next header 719 */ 720 #ifdef IFA_STATS 721 if (deliverifp != NULL) { 722 struct in6_ifaddr *ia6; 723 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 724 if (ia6) 725 ia6->ia_ifa.ifa_data.ifad_inbytes += m->m_pkthdr.len; 726 } 727 #endif 728 ip6stat.ip6s_delivered++; 729 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 730 nest = 0; 731 732 while (nxt != IPPROTO_DONE) { 733 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 734 ip6stat.ip6s_toomanyhdr++; 735 goto bad; 736 } 737 738 /* 739 * protection against faulty packet - there should be 740 * more sanity checks in header chain processing. 741 */ 742 if (m->m_pkthdr.len < off) { 743 ip6stat.ip6s_tooshort++; 744 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 745 goto bad; 746 } 747 748 #ifdef IPSEC 749 /* 750 * enforce IPsec policy checking if we are seeing last header. 751 * note that we do not visit this with protocols with pcb layer 752 * code - like udp/tcp/raw ip. 753 */ 754 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && 755 ipsec6_in_reject(m, NULL)) { 756 ipsec6stat.in_polvio++; 757 goto bad; 758 } 759 #endif 760 761 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 762 } 763 return; 764 bad: 765 m_freem(m); 766 } 767 768 /* 769 * Hop-by-Hop options header processing. If a valid jumbo payload option is 770 * included, the real payload length will be stored in plenp. 771 */ 772 static int 773 ip6_hopopts_input(plenp, rtalertp, mp, offp) 774 u_int32_t *plenp; 775 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 776 struct mbuf **mp; 777 int *offp; 778 { 779 struct mbuf *m = *mp; 780 int off = *offp, hbhlen; 781 struct ip6_hbh *hbh; 782 u_int8_t *opt; 783 784 /* validation of the length of the header */ 785 #ifndef PULLDOWN_TEST 786 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 787 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 788 hbhlen = (hbh->ip6h_len + 1) << 3; 789 790 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 791 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 792 #else 793 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 794 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 795 if (hbh == NULL) { 796 ip6stat.ip6s_tooshort++; 797 return -1; 798 } 799 hbhlen = (hbh->ip6h_len + 1) << 3; 800 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 801 hbhlen); 802 if (hbh == NULL) { 803 ip6stat.ip6s_tooshort++; 804 return -1; 805 } 806 #endif 807 KASSERT(IP6_HDR_ALIGNED_P(hbh)); 808 off += hbhlen; 809 hbhlen -= sizeof(struct ip6_hbh); 810 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 811 812 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 813 hbhlen, rtalertp, plenp) < 0) 814 return (-1); 815 816 *offp = off; 817 *mp = m; 818 return (0); 819 } 820 821 /* 822 * Search header for all Hop-by-hop options and process each option. 823 * This function is separate from ip6_hopopts_input() in order to 824 * handle a case where the sending node itself process its hop-by-hop 825 * options header. In such a case, the function is called from ip6_output(). 826 * 827 * The function assumes that hbh header is located right after the IPv6 header 828 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 829 * opthead + hbhlen is located in continuous memory region. 830 */ 831 int 832 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 833 struct mbuf *m; 834 u_int8_t *opthead; 835 int hbhlen; 836 u_int32_t *rtalertp; 837 u_int32_t *plenp; 838 { 839 struct ip6_hdr *ip6; 840 int optlen = 0; 841 u_int8_t *opt = opthead; 842 u_int16_t rtalert_val; 843 u_int32_t jumboplen; 844 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 845 846 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 847 switch (*opt) { 848 case IP6OPT_PAD1: 849 optlen = 1; 850 break; 851 case IP6OPT_PADN: 852 if (hbhlen < IP6OPT_MINLEN) { 853 ip6stat.ip6s_toosmall++; 854 goto bad; 855 } 856 optlen = *(opt + 1) + 2; 857 break; 858 case IP6OPT_RTALERT: 859 /* XXX may need check for alignment */ 860 if (hbhlen < IP6OPT_RTALERT_LEN) { 861 ip6stat.ip6s_toosmall++; 862 goto bad; 863 } 864 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 865 /* XXX stat */ 866 icmp6_error(m, ICMP6_PARAM_PROB, 867 ICMP6_PARAMPROB_HEADER, 868 erroff + opt + 1 - opthead); 869 return (-1); 870 } 871 optlen = IP6OPT_RTALERT_LEN; 872 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 873 *rtalertp = ntohs(rtalert_val); 874 break; 875 case IP6OPT_JUMBO: 876 /* XXX may need check for alignment */ 877 if (hbhlen < IP6OPT_JUMBO_LEN) { 878 ip6stat.ip6s_toosmall++; 879 goto bad; 880 } 881 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 882 /* XXX stat */ 883 icmp6_error(m, ICMP6_PARAM_PROB, 884 ICMP6_PARAMPROB_HEADER, 885 erroff + opt + 1 - opthead); 886 return (-1); 887 } 888 optlen = IP6OPT_JUMBO_LEN; 889 890 /* 891 * IPv6 packets that have non 0 payload length 892 * must not contain a jumbo payload option. 893 */ 894 ip6 = mtod(m, struct ip6_hdr *); 895 if (ip6->ip6_plen) { 896 ip6stat.ip6s_badoptions++; 897 icmp6_error(m, ICMP6_PARAM_PROB, 898 ICMP6_PARAMPROB_HEADER, 899 erroff + opt - opthead); 900 return (-1); 901 } 902 903 /* 904 * We may see jumbolen in unaligned location, so 905 * we'd need to perform bcopy(). 906 */ 907 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 908 jumboplen = (u_int32_t)htonl(jumboplen); 909 910 #if 1 911 /* 912 * if there are multiple jumbo payload options, 913 * *plenp will be non-zero and the packet will be 914 * rejected. 915 * the behavior may need some debate in ipngwg - 916 * multiple options does not make sense, however, 917 * there's no explicit mention in specification. 918 */ 919 if (*plenp != 0) { 920 ip6stat.ip6s_badoptions++; 921 icmp6_error(m, ICMP6_PARAM_PROB, 922 ICMP6_PARAMPROB_HEADER, 923 erroff + opt + 2 - opthead); 924 return (-1); 925 } 926 #endif 927 928 /* 929 * jumbo payload length must be larger than 65535. 930 */ 931 if (jumboplen <= IPV6_MAXPACKET) { 932 ip6stat.ip6s_badoptions++; 933 icmp6_error(m, ICMP6_PARAM_PROB, 934 ICMP6_PARAMPROB_HEADER, 935 erroff + opt + 2 - opthead); 936 return (-1); 937 } 938 *plenp = jumboplen; 939 940 break; 941 default: /* unknown option */ 942 if (hbhlen < IP6OPT_MINLEN) { 943 ip6stat.ip6s_toosmall++; 944 goto bad; 945 } 946 optlen = ip6_unknown_opt(opt, m, 947 erroff + opt - opthead); 948 if (optlen == -1) 949 return (-1); 950 optlen += 2; 951 break; 952 } 953 } 954 955 return (0); 956 957 bad: 958 m_freem(m); 959 return (-1); 960 } 961 962 /* 963 * Unknown option processing. 964 * The third argument `off' is the offset from the IPv6 header to the option, 965 * which is necessary if the IPv6 header the and option header and IPv6 header 966 * is not continuous in order to return an ICMPv6 error. 967 */ 968 int 969 ip6_unknown_opt(optp, m, off) 970 u_int8_t *optp; 971 struct mbuf *m; 972 int off; 973 { 974 struct ip6_hdr *ip6; 975 976 switch (IP6OPT_TYPE(*optp)) { 977 case IP6OPT_TYPE_SKIP: /* ignore the option */ 978 return ((int)*(optp + 1)); 979 case IP6OPT_TYPE_DISCARD: /* silently discard */ 980 m_freem(m); 981 return (-1); 982 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 983 ip6stat.ip6s_badoptions++; 984 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 985 return (-1); 986 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 987 ip6stat.ip6s_badoptions++; 988 ip6 = mtod(m, struct ip6_hdr *); 989 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 990 (m->m_flags & (M_BCAST|M_MCAST))) 991 m_freem(m); 992 else 993 icmp6_error(m, ICMP6_PARAM_PROB, 994 ICMP6_PARAMPROB_OPTION, off); 995 return (-1); 996 } 997 998 m_freem(m); /* XXX: NOTREACHED */ 999 return (-1); 1000 } 1001 1002 /* 1003 * Create the "control" list for this pcb. 1004 * 1005 * The routine will be called from upper layer handlers like tcp6_input(). 1006 * Thus the routine assumes that the caller (tcp6_input) have already 1007 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1008 * very first mbuf on the mbuf chain. 1009 * We may want to add some infinite loop prevention or sanity checks for safety. 1010 * (This applies only when you are using KAME mbuf chain restriction, i.e. 1011 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 1012 */ 1013 void 1014 ip6_savecontrol(in6p, mp, ip6, m) 1015 struct in6pcb *in6p; 1016 struct mbuf **mp; 1017 struct ip6_hdr *ip6; 1018 struct mbuf *m; 1019 { 1020 struct proc *p = curproc; /* XXX */ 1021 int privileged; 1022 1023 privileged = 0; 1024 if (p && !suser(p->p_ucred, &p->p_acflag)) 1025 privileged++; 1026 1027 #ifdef SO_TIMESTAMP 1028 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1029 struct timeval tv; 1030 1031 microtime(&tv); 1032 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1033 SCM_TIMESTAMP, SOL_SOCKET); 1034 if (*mp) 1035 mp = &(*mp)->m_next; 1036 } 1037 #endif 1038 if (in6p->in6p_flags & IN6P_RECVDSTADDR) { 1039 *mp = sbcreatecontrol((caddr_t) &ip6->ip6_dst, 1040 sizeof(struct in6_addr), IPV6_RECVDSTADDR, 1041 IPPROTO_IPV6); 1042 if (*mp) 1043 mp = &(*mp)->m_next; 1044 } 1045 1046 #ifdef noyet 1047 /* options were tossed above */ 1048 if (in6p->in6p_flags & IN6P_RECVOPTS) 1049 /* broken */ 1050 /* ip6_srcroute doesn't do what we want here, need to fix */ 1051 if (in6p->in6p_flags & IPV6P_RECVRETOPTS) 1052 /* broken */ 1053 #endif 1054 1055 /* RFC 2292 sec. 5 */ 1056 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1057 struct in6_pktinfo pi6; 1058 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1059 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1060 pi6.ipi6_addr.s6_addr16[1] = 0; 1061 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1062 ? m->m_pkthdr.rcvif->if_index 1063 : 0; 1064 *mp = sbcreatecontrol((caddr_t) &pi6, 1065 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1066 IPPROTO_IPV6); 1067 if (*mp) 1068 mp = &(*mp)->m_next; 1069 } 1070 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1071 int hlim = ip6->ip6_hlim & 0xff; 1072 *mp = sbcreatecontrol((caddr_t) &hlim, 1073 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1074 if (*mp) 1075 mp = &(*mp)->m_next; 1076 } 1077 /* IN6P_NEXTHOP - for outgoing packet only */ 1078 1079 /* 1080 * IPV6_HOPOPTS socket option. We require super-user privilege 1081 * for the option, but it might be too strict, since there might 1082 * be some hop-by-hop options which can be returned to normal user. 1083 * See RFC 2292 section 6. 1084 */ 1085 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { 1086 /* 1087 * Check if a hop-by-hop options header is contatined in the 1088 * received packet, and if so, store the options as ancillary 1089 * data. Note that a hop-by-hop options header must be 1090 * just after the IPv6 header, which fact is assured through 1091 * the IPv6 input processing. 1092 */ 1093 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1094 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1095 struct ip6_hbh *hbh; 1096 int hbhlen; 1097 1098 #ifndef PULLDOWN_TEST 1099 hbh = (struct ip6_hbh *)(ip6 + 1); 1100 hbhlen = (hbh->ip6h_len + 1) << 3; 1101 #else 1102 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 1103 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 1104 if (hbh == NULL) { 1105 ip6stat.ip6s_tooshort++; 1106 return; 1107 } 1108 hbhlen = (hbh->ip6h_len + 1) << 3; 1109 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 1110 sizeof(struct ip6_hdr), hbhlen); 1111 if (hbh == NULL) { 1112 ip6stat.ip6s_tooshort++; 1113 return; 1114 } 1115 #endif 1116 1117 /* 1118 * XXX: We copy whole the header even if a jumbo 1119 * payload option is included, which option is to 1120 * be removed before returning in the RFC 2292. 1121 * But it's too painful operation... 1122 */ 1123 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1124 IPV6_HOPOPTS, IPPROTO_IPV6); 1125 if (*mp) 1126 mp = &(*mp)->m_next; 1127 } 1128 } 1129 1130 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1131 if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) { 1132 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1133 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);; 1134 1135 /* 1136 * Search for destination options headers or routing 1137 * header(s) through the header chain, and stores each 1138 * header as ancillary data. 1139 * Note that the order of the headers remains in 1140 * the chain of ancillary data. 1141 */ 1142 while (1) { /* is explicit loop prevention necessary? */ 1143 struct ip6_ext *ip6e; 1144 int elen; 1145 1146 #ifndef PULLDOWN_TEST 1147 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1148 if (nxt == IPPROTO_AH) 1149 elen = (ip6e->ip6e_len + 2) << 2; 1150 else 1151 elen = (ip6e->ip6e_len + 1) << 3; 1152 #else 1153 IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, 1154 sizeof(struct ip6_ext)); 1155 if (ip6e == NULL) { 1156 ip6stat.ip6s_tooshort++; 1157 return; 1158 } 1159 if (nxt == IPPROTO_AH) 1160 elen = (ip6e->ip6e_len + 2) << 2; 1161 else 1162 elen = (ip6e->ip6e_len + 1) << 3; 1163 IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, elen); 1164 if (ip6e == NULL) { 1165 ip6stat.ip6s_tooshort++; 1166 return; 1167 } 1168 #endif 1169 KASSERT(IP6_HDR_ALIGNED_P(ip6e)); 1170 1171 switch (nxt) { 1172 case IPPROTO_DSTOPTS: 1173 if (!in6p->in6p_flags & IN6P_DSTOPTS) 1174 break; 1175 1176 /* 1177 * We also require super-user privilege for 1178 * the option. 1179 * See the comments on IN6_HOPOPTS. 1180 */ 1181 if (!privileged) 1182 break; 1183 1184 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1185 IPV6_DSTOPTS, 1186 IPPROTO_IPV6); 1187 if (*mp) 1188 mp = &(*mp)->m_next; 1189 break; 1190 1191 case IPPROTO_ROUTING: 1192 if (!in6p->in6p_flags & IN6P_RTHDR) 1193 break; 1194 1195 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1196 IPV6_RTHDR, 1197 IPPROTO_IPV6); 1198 if (*mp) 1199 mp = &(*mp)->m_next; 1200 break; 1201 1202 case IPPROTO_UDP: 1203 case IPPROTO_TCP: 1204 case IPPROTO_ICMPV6: 1205 default: 1206 /* 1207 * stop search if we encounter an upper 1208 * layer protocol headers. 1209 */ 1210 goto loopend; 1211 1212 case IPPROTO_HOPOPTS: 1213 case IPPROTO_AH: /* is it possible? */ 1214 break; 1215 } 1216 1217 /* proceed with the next header. */ 1218 off += elen; 1219 nxt = ip6e->ip6e_nxt; 1220 } 1221 loopend: 1222 ; 1223 } 1224 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1225 /* to be done */ 1226 } 1227 if ((in6p->in6p_flags & IN6P_DSTOPTS) && privileged) { 1228 /* to be done */ 1229 } 1230 /* IN6P_RTHDR - to be done */ 1231 1232 } 1233 1234 /* 1235 * Get pointer to the previous header followed by the header 1236 * currently processed. 1237 * XXX: This function supposes that 1238 * M includes all headers, 1239 * the next header field and the header length field of each header 1240 * are valid, and 1241 * the sum of each header length equals to OFF. 1242 * Because of these assumptions, this function must be called very 1243 * carefully. Moreover, it will not be used in the near future when 1244 * we develop `neater' mechanism to process extension headers. 1245 */ 1246 u_int8_t * 1247 ip6_get_prevhdr(m, off) 1248 struct mbuf *m; 1249 int off; 1250 { 1251 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1252 1253 if (off == sizeof(struct ip6_hdr)) 1254 return (&ip6->ip6_nxt); 1255 else { 1256 int len, nxt; 1257 struct ip6_ext *ip6e = NULL; 1258 1259 nxt = ip6->ip6_nxt; 1260 len = sizeof(struct ip6_hdr); 1261 while (len < off) { 1262 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1263 1264 switch (nxt) { 1265 case IPPROTO_FRAGMENT: 1266 len += sizeof(struct ip6_frag); 1267 break; 1268 case IPPROTO_AH: 1269 len += (ip6e->ip6e_len + 2) << 2; 1270 break; 1271 default: 1272 len += (ip6e->ip6e_len + 1) << 3; 1273 break; 1274 } 1275 nxt = ip6e->ip6e_nxt; 1276 } 1277 if (ip6e) 1278 return (&ip6e->ip6e_nxt); 1279 else 1280 return NULL; 1281 } 1282 } 1283 1284 /* 1285 * get next header offset. m will be retained. 1286 */ 1287 int 1288 ip6_nexthdr(m, off, proto, nxtp) 1289 struct mbuf *m; 1290 int off; 1291 int proto; 1292 int *nxtp; 1293 { 1294 struct ip6_hdr ip6; 1295 struct ip6_ext ip6e; 1296 struct ip6_frag fh; 1297 1298 /* just in case */ 1299 if (m == NULL) 1300 panic("ip6_nexthdr: m == NULL"); 1301 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1302 return -1; 1303 1304 switch (proto) { 1305 case IPPROTO_IPV6: 1306 if (m->m_pkthdr.len < off + sizeof(ip6)) 1307 return -1; 1308 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1309 if (nxtp) 1310 *nxtp = ip6.ip6_nxt; 1311 off += sizeof(ip6); 1312 return off; 1313 1314 case IPPROTO_FRAGMENT: 1315 /* 1316 * terminate parsing if it is not the first fragment, 1317 * it does not make sense to parse through it. 1318 */ 1319 if (m->m_pkthdr.len < off + sizeof(fh)) 1320 return -1; 1321 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1322 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1323 return -1; 1324 if (nxtp) 1325 *nxtp = fh.ip6f_nxt; 1326 off += sizeof(struct ip6_frag); 1327 return off; 1328 1329 case IPPROTO_AH: 1330 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1331 return -1; 1332 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1333 if (nxtp) 1334 *nxtp = ip6e.ip6e_nxt; 1335 off += (ip6e.ip6e_len + 2) << 2; 1336 if (m->m_pkthdr.len < off) 1337 return -1; 1338 return off; 1339 1340 case IPPROTO_HOPOPTS: 1341 case IPPROTO_ROUTING: 1342 case IPPROTO_DSTOPTS: 1343 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1344 return -1; 1345 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1346 if (nxtp) 1347 *nxtp = ip6e.ip6e_nxt; 1348 off += (ip6e.ip6e_len + 1) << 3; 1349 if (m->m_pkthdr.len < off) 1350 return -1; 1351 return off; 1352 1353 case IPPROTO_NONE: 1354 case IPPROTO_ESP: 1355 case IPPROTO_IPCOMP: 1356 /* give up */ 1357 return -1; 1358 1359 default: 1360 return -1; 1361 } 1362 1363 return -1; 1364 } 1365 1366 /* 1367 * get offset for the last header in the chain. m will be kept untainted. 1368 */ 1369 int 1370 ip6_lasthdr(m, off, proto, nxtp) 1371 struct mbuf *m; 1372 int off; 1373 int proto; 1374 int *nxtp; 1375 { 1376 int newoff; 1377 int nxt; 1378 1379 if (!nxtp) { 1380 nxt = -1; 1381 nxtp = &nxt; 1382 } 1383 while (1) { 1384 newoff = ip6_nexthdr(m, off, proto, nxtp); 1385 if (newoff < 0) 1386 return off; 1387 else if (newoff < off) 1388 return -1; /* invalid */ 1389 else if (newoff == off) 1390 return newoff; 1391 1392 off = newoff; 1393 proto = *nxtp; 1394 } 1395 } 1396 1397 /* 1398 * System control for IP6 1399 */ 1400 1401 u_char inet6ctlerrmap[PRC_NCMDS] = { 1402 0, 0, 0, 0, 1403 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1404 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1405 EMSGSIZE, EHOSTUNREACH, 0, 0, 1406 0, 0, 0, 0, 1407 ENOPROTOOPT 1408 }; 1409 1410 int 1411 ip6_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1412 int *name; 1413 u_int namelen; 1414 void *oldp; 1415 size_t *oldlenp; 1416 void *newp; 1417 size_t newlen; 1418 { 1419 int old, error; 1420 1421 /* All sysctl names at this level are terminal. */ 1422 if (namelen != 1) 1423 return ENOTDIR; 1424 1425 switch (name[0]) { 1426 1427 case IPV6CTL_FORWARDING: 1428 return sysctl_int(oldp, oldlenp, newp, newlen, 1429 &ip6_forwarding); 1430 case IPV6CTL_SENDREDIRECTS: 1431 return sysctl_int(oldp, oldlenp, newp, newlen, 1432 &ip6_sendredirects); 1433 case IPV6CTL_DEFHLIM: 1434 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_defhlim); 1435 case IPV6CTL_MAXFRAGPACKETS: 1436 return sysctl_int(oldp, oldlenp, newp, newlen, 1437 &ip6_maxfragpackets); 1438 case IPV6CTL_ACCEPT_RTADV: 1439 return sysctl_int(oldp, oldlenp, newp, newlen, 1440 &ip6_accept_rtadv); 1441 case IPV6CTL_KEEPFAITH: 1442 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_keepfaith); 1443 case IPV6CTL_LOG_INTERVAL: 1444 return sysctl_int(oldp, oldlenp, newp, newlen, 1445 &ip6_log_interval); 1446 case IPV6CTL_HDRNESTLIMIT: 1447 return sysctl_int(oldp, oldlenp, newp, newlen, 1448 &ip6_hdrnestlimit); 1449 case IPV6CTL_DAD_COUNT: 1450 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_dad_count); 1451 case IPV6CTL_AUTO_FLOWLABEL: 1452 return sysctl_int(oldp, oldlenp, newp, newlen, 1453 &ip6_auto_flowlabel); 1454 case IPV6CTL_DEFMCASTHLIM: 1455 return sysctl_int(oldp, oldlenp, newp, newlen, 1456 &ip6_defmcasthlim); 1457 #if NGIF > 0 1458 case IPV6CTL_GIF_HLIM: 1459 return sysctl_int(oldp, oldlenp, newp, newlen, 1460 &ip6_gif_hlim); 1461 #endif 1462 case IPV6CTL_KAME_VERSION: 1463 return sysctl_rdstring(oldp, oldlenp, newp, __KAME_VERSION); 1464 case IPV6CTL_USE_DEPRECATED: 1465 return sysctl_int(oldp, oldlenp, newp, newlen, 1466 &ip6_use_deprecated); 1467 case IPV6CTL_RR_PRUNE: 1468 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_rr_prune); 1469 case IPV6CTL_V6ONLY: 1470 #ifdef INET6_BINDV6ONLY 1471 return sysctl_rdint(oldp, oldlenp, newp, ip6_v6only); 1472 #else 1473 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_v6only); 1474 #endif 1475 case IPV6CTL_ANONPORTMIN: 1476 old = ip6_anonportmin; 1477 error = sysctl_int(oldp, oldlenp, newp, newlen, 1478 &ip6_anonportmin); 1479 if (ip6_anonportmin >= ip6_anonportmax || ip6_anonportmin < 0 || 1480 ip6_anonportmin > 65535 1481 #ifndef IPNOPRIVPORTS 1482 || ip6_anonportmin < IPV6PORT_RESERVED 1483 #endif 1484 ) { 1485 ip6_anonportmin = old; 1486 return (EINVAL); 1487 } 1488 return (error); 1489 case IPV6CTL_ANONPORTMAX: 1490 old = ip6_anonportmax; 1491 error = sysctl_int(oldp, oldlenp, newp, newlen, 1492 &ip6_anonportmax); 1493 if (ip6_anonportmin >= ip6_anonportmax || ip6_anonportmax < 0 || 1494 ip6_anonportmax > 65535 1495 #ifndef IPNOPRIVPORTS 1496 || ip6_anonportmax < IPV6PORT_RESERVED 1497 #endif 1498 ) { 1499 ip6_anonportmax = old; 1500 return (EINVAL); 1501 } 1502 return (error); 1503 #ifndef IPNOPRIVPORTS 1504 case IPV6CTL_LOWPORTMIN: 1505 old = ip6_lowportmin; 1506 error = sysctl_int(oldp, oldlenp, newp, newlen, 1507 &ip6_lowportmin); 1508 if (ip6_lowportmin >= ip6_lowportmax || 1509 ip6_lowportmin > IPV6PORT_RESERVEDMAX || 1510 ip6_lowportmin < IPV6PORT_RESERVEDMIN) { 1511 ip6_lowportmin = old; 1512 return (EINVAL); 1513 } 1514 return (error); 1515 case IPV6CTL_LOWPORTMAX: 1516 old = ip6_lowportmax; 1517 error = sysctl_int(oldp, oldlenp, newp, newlen, 1518 &ip6_lowportmax); 1519 if (ip6_lowportmin >= ip6_lowportmax || 1520 ip6_lowportmax > IPV6PORT_RESERVEDMAX || 1521 ip6_lowportmax < IPV6PORT_RESERVEDMIN) { 1522 ip6_lowportmax = old; 1523 return (EINVAL); 1524 } 1525 return (error); 1526 #endif 1527 case IPV6CTL_MAXFRAGS: 1528 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_maxfrags); 1529 default: 1530 return EOPNOTSUPP; 1531 } 1532 /* NOTREACHED */ 1533 } 1534
Indexes created Mon Sep 22 05:09:51 GMT 2025