1 /* $OpenBSD: ip6_input.c,v 1.39 2002/01/02 22:47:47 deraadt 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 "pf.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/domain.h> 75 #include <sys/protosw.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/errno.h> 79 #include <sys/time.h> 80 #include <sys/kernel.h> 81 #include <sys/syslog.h> 82 #include <sys/proc.h> 83 84 #include <net/if.h> 85 #include <net/if_types.h> 86 #include <net/if_dl.h> 87 #include <net/route.h> 88 #include <net/netisr.h> 89 90 #include <netinet/in.h> 91 #include <netinet/in_systm.h> 92 93 #ifdef INET 94 #include <netinet/ip.h> 95 #include <netinet/ip_icmp.h> 96 #endif /*INET*/ 97 98 #include <netinet/in_pcb.h> 99 #include <netinet6/in6_var.h> 100 #include <netinet/ip6.h> 101 #include <netinet6/ip6_var.h> 102 #include <netinet/icmp6.h> 103 #include <netinet6/in6_ifattach.h> 104 #include <netinet6/nd6.h> 105 #include <netinet6/in6_prefix.h> 106 107 #include <netinet6/ip6protosw.h> 108 109 #include "faith.h" 110 #include "gif.h" 111 #include "bpfilter.h" 112 113 #if NPF > 0 114 #include <net/pfvar.h> 115 #endif 116 117 extern struct domain inet6domain; 118 extern struct ip6protosw inet6sw[]; 119 120 u_char ip6_protox[IPPROTO_MAX]; 121 static int ip6qmaxlen = IFQ_MAXLEN; 122 struct in6_ifaddr *in6_ifaddr; 123 struct ifqueue ip6intrq; 124 125 int ip6_forward_srcrt; /* XXX */ 126 int ip6_sourcecheck; /* XXX */ 127 int ip6_sourcecheck_interval; /* XXX */ 128 129 struct ip6stat ip6stat; 130 131 static void ip6_init2 __P((void *)); 132 133 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 134 #ifdef PULLDOWN_TEST 135 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 136 #endif 137 138 /* 139 * IP6 initialization: fill in IP6 protocol switch table. 140 * All protocols not implemented in kernel go to raw IP6 protocol handler. 141 */ 142 void 143 ip6_init() 144 { 145 struct ip6protosw *pr; 146 int i; 147 148 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 149 if (pr == 0) 150 panic("ip6_init"); 151 for (i = 0; i < IPPROTO_MAX; i++) 152 ip6_protox[i] = pr - inet6sw; 153 for (pr = (struct ip6protosw *)inet6domain.dom_protosw; 154 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) 155 if (pr->pr_domain->dom_family == PF_INET6 && 156 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 157 ip6_protox[pr->pr_protocol] = pr - inet6sw; 158 ip6intrq.ifq_maxlen = ip6qmaxlen; 159 nd6_init(); 160 frag6_init(); 161 ip6_flow_seq = arc4random(); 162 ip6_init2((void *)0); 163 } 164 165 static void 166 ip6_init2(dummy) 167 void *dummy; 168 { 169 170 #if 1 171 /* 172 * to route local address of p2p link to loopback, 173 * assign loopback address first. 174 */ 175 in6_ifattach(lo0ifp, NULL); 176 #else 177 /* you MUST bring lo0 up manually, in rc script. */ 178 #endif 179 180 /* nd6_timer_init */ 181 bzero(&nd6_timer_ch, sizeof(nd6_timer_ch)); 182 timeout_set(&nd6_timer_ch, nd6_timer, NULL); 183 timeout_add(&nd6_timer_ch, hz); 184 185 /* router renumbering prefix list maintenance */ 186 bzero(&in6_rr_timer_ch, sizeof(in6_rr_timer_ch)); 187 timeout_set(&in6_rr_timer_ch, in6_rr_timer, (caddr_t)0); 188 timeout_add(&in6_rr_timer_ch, hz); 189 } 190 191 /* 192 * IP6 input interrupt handling. Just pass the packet to ip6_input. 193 */ 194 void 195 ip6intr() 196 { 197 int s; 198 struct mbuf *m; 199 200 for (;;) { 201 s = splimp(); 202 IF_DEQUEUE(&ip6intrq, m); 203 splx(s); 204 if (m == 0) 205 return; 206 ip6_input(m); 207 } 208 } 209 210 extern struct route_in6 ip6_forward_rt; 211 212 void 213 ip6_input(m) 214 struct mbuf *m; 215 { 216 struct ip6_hdr *ip6; 217 int off = sizeof(struct ip6_hdr), nest; 218 u_int32_t plen; 219 u_int32_t rtalert = ~0; 220 int nxt, ours = 0; 221 struct ifnet *deliverifp = NULL; 222 223 #if 0 /* IPSEC */ 224 /* 225 * should the inner packet be considered authentic? 226 * see comment in ah4_input(). 227 */ 228 if (m) { 229 m->m_flags &= ~M_AUTHIPHDR; 230 m->m_flags &= ~M_AUTHIPDGM; 231 } 232 #endif 233 234 /* 235 * mbuf statistics by kazu 236 */ 237 if (m->m_flags & M_EXT) { 238 if (m->m_next) 239 ip6stat.ip6s_mext2m++; 240 else 241 ip6stat.ip6s_mext1++; 242 } else { 243 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 244 if (m->m_next) { 245 if (m->m_flags & M_LOOP) { 246 ip6stat.ip6s_m2m[lo0ifp->if_index]++; /*XXX*/ 247 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 248 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 249 else 250 ip6stat.ip6s_m2m[0]++; 251 } else 252 ip6stat.ip6s_m1++; 253 #undef M2MMAX 254 } 255 256 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 257 ip6stat.ip6s_total++; 258 259 #ifndef PULLDOWN_TEST 260 /* XXX is the line really necessary? */ 261 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 262 #endif 263 264 if (m->m_len < sizeof(struct ip6_hdr)) { 265 struct ifnet *inifp; 266 inifp = m->m_pkthdr.rcvif; 267 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 268 ip6stat.ip6s_toosmall++; 269 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 270 return; 271 } 272 } 273 274 ip6 = mtod(m, struct ip6_hdr *); 275 276 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 277 ip6stat.ip6s_badvers++; 278 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 279 goto bad; 280 } 281 282 #if NPF > 0 283 /* 284 * Packet filter 285 */ 286 if (pf_test6(PF_IN, m->m_pkthdr.rcvif, &m) != PF_PASS) 287 goto bad; 288 if (m == NULL) 289 return; 290 291 ip6 = mtod(m, struct ip6_hdr *); 292 #endif 293 294 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 295 296 #ifdef ALTQ 297 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 298 /* packet is dropped by traffic conditioner */ 299 return; 300 } 301 #endif 302 303 /* 304 * Check against address spoofing/corruption. 305 */ 306 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 307 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 308 /* 309 * XXX: "badscope" is not very suitable for a multicast source. 310 */ 311 ip6stat.ip6s_badscope++; 312 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 313 goto bad; 314 } 315 /* 316 * The following check is not documented in specs. A malicious 317 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 318 * and bypass security checks (act as if it was from 127.0.0.1 by using 319 * IPv6 src ::ffff:127.0.0.1). Be cautious. 320 * 321 * This check chokes if we are in an SIIT cloud. As none of BSDs 322 * support IPv4-less kernel compilation, we cannot support SIIT 323 * environment at all. So, it makes more sense for us to reject any 324 * malicious packets for non-SIIT environment, than try to do a 325 * partical support for SIIT environment. 326 */ 327 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 328 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 329 ip6stat.ip6s_badscope++; 330 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 331 goto bad; 332 } 333 #if 0 334 /* 335 * Reject packets with IPv4 compatible addresses (auto tunnel). 336 * 337 * The code forbids auto tunnel relay case in RFC1933 (the check is 338 * stronger than RFC1933). We may want to re-enable it if mech-xx 339 * is revised to forbid relaying case. 340 */ 341 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 342 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 343 ip6stat.ip6s_badscope++; 344 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 345 goto bad; 346 } 347 #endif 348 349 if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 350 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) { 351 if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) { 352 ours = 1; 353 deliverifp = m->m_pkthdr.rcvif; 354 goto hbhcheck; 355 } else { 356 ip6stat.ip6s_badscope++; 357 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 358 goto bad; 359 } 360 } 361 362 /* drop packets if interface ID portion is already filled */ 363 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 364 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 365 ip6->ip6_src.s6_addr16[1]) { 366 ip6stat.ip6s_badscope++; 367 goto bad; 368 } 369 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 370 ip6->ip6_dst.s6_addr16[1]) { 371 ip6stat.ip6s_badscope++; 372 goto bad; 373 } 374 } 375 376 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 377 ip6->ip6_src.s6_addr16[1] 378 = htons(m->m_pkthdr.rcvif->if_index); 379 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 380 ip6->ip6_dst.s6_addr16[1] 381 = htons(m->m_pkthdr.rcvif->if_index); 382 383 /* 384 * We use rt->rt_ifp to determine if the address is ours or not. 385 * If rt_ifp is lo0, the address is ours. 386 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 387 * so any address under fe80::%lo0/64 will be mistakenly considered 388 * local. The special case is supplied to handle the case properly 389 * by actually looking at interface addresses 390 * (using in6ifa_ifpwithaddr). 391 */ 392 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 393 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 394 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 395 icmp6_error(m, ICMP6_DST_UNREACH, 396 ICMP6_DST_UNREACH_ADDR, 0); 397 /* m is already freed */ 398 return; 399 } 400 401 ours = 1; 402 deliverifp = m->m_pkthdr.rcvif; 403 goto hbhcheck; 404 } 405 406 /* 407 * Multicast check 408 */ 409 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 410 struct in6_multi *in6m = 0; 411 412 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 413 /* 414 * See if we belong to the destination multicast group on the 415 * arrival interface. 416 */ 417 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 418 if (in6m) 419 ours = 1; 420 else if (!ip6_mrouter) { 421 ip6stat.ip6s_notmember++; 422 ip6stat.ip6s_cantforward++; 423 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 424 goto bad; 425 } 426 deliverifp = m->m_pkthdr.rcvif; 427 goto hbhcheck; 428 } 429 430 /* 431 * Unicast check 432 */ 433 if (ip6_forward_rt.ro_rt != NULL && 434 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 435 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 436 &ip6_forward_rt.ro_dst.sin6_addr)) 437 ip6stat.ip6s_forward_cachehit++; 438 else { 439 if (ip6_forward_rt.ro_rt) { 440 /* route is down or destination is different */ 441 ip6stat.ip6s_forward_cachemiss++; 442 RTFREE(ip6_forward_rt.ro_rt); 443 ip6_forward_rt.ro_rt = 0; 444 } 445 446 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 447 ip6_forward_rt.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 448 ip6_forward_rt.ro_dst.sin6_family = AF_INET6; 449 ip6_forward_rt.ro_dst.sin6_addr = ip6->ip6_dst; 450 451 rtalloc((struct route *)&ip6_forward_rt); 452 } 453 454 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 455 456 /* 457 * Accept the packet if the forwarding interface to the destination 458 * according to the routing table is the loopback interface, 459 * unless the associated route has a gateway. 460 * Note that this approach causes to accept a packet if there is a 461 * route to the loopback interface for the destination of the packet. 462 * But we think it's even useful in some situations, e.g. when using 463 * a special daemon which wants to intercept the packet. 464 */ 465 if (ip6_forward_rt.ro_rt && 466 (ip6_forward_rt.ro_rt->rt_flags & 467 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 468 #if 0 469 /* 470 * The check below is redundant since the comparison of 471 * the destination and the key of the rtentry has 472 * already done through looking up the routing table. 473 */ 474 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 475 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && 476 #endif 477 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 478 struct in6_ifaddr *ia6 = 479 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 480 if (ia6->ia6_flags & IN6_IFF_ANYCAST) 481 m->m_flags |= M_ANYCAST6; 482 /* 483 * packets to a tentative, duplicated, or somehow invalid 484 * address must not be accepted. 485 */ 486 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 487 /* this address is ready */ 488 ours = 1; 489 deliverifp = ia6->ia_ifp; /* correct? */ 490 goto hbhcheck; 491 } else { 492 /* address is not ready, so discard the packet. */ 493 nd6log((LOG_INFO, 494 "ip6_input: packet to an unready address %s->%s\n", 495 ip6_sprintf(&ip6->ip6_src), 496 ip6_sprintf(&ip6->ip6_dst))); 497 498 goto bad; 499 } 500 } 501 502 /* 503 * FAITH(Firewall Aided Internet Translator) 504 */ 505 #if defined(NFAITH) && 0 < NFAITH 506 if (ip6_keepfaith) { 507 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 508 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 509 /* XXX do we need more sanity checks? */ 510 ours = 1; 511 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/ 512 goto hbhcheck; 513 } 514 } 515 #endif 516 517 #if 0 518 { 519 /* 520 * Last resort: check in6_ifaddr for incoming interface. 521 * The code is here until I update the "goto ours hack" code above 522 * working right. 523 */ 524 struct ifaddr *ifa; 525 for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; 526 ifa; 527 ifa = ifa->ifa_list.tqe_next) { 528 if (ifa->ifa_addr == NULL) 529 continue; /* just for safety */ 530 if (ifa->ifa_addr->sa_family != AF_INET6) 531 continue; 532 if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) { 533 ours = 1; 534 deliverifp = ifa->ifa_ifp; 535 goto hbhcheck; 536 } 537 } 538 } 539 #endif 540 541 /* 542 * Now there is no reason to process the packet if it's not our own 543 * and we're not a router. 544 */ 545 if (!ip6_forwarding) { 546 ip6stat.ip6s_cantforward++; 547 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 548 goto bad; 549 } 550 551 hbhcheck: 552 /* 553 * Process Hop-by-Hop options header if it's contained. 554 * m may be modified in ip6_hopopts_input(). 555 * If a JumboPayload option is included, plen will also be modified. 556 */ 557 plen = (u_int32_t)ntohs(ip6->ip6_plen); 558 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 559 struct ip6_hbh *hbh; 560 561 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 562 #if 0 /*touches NULL pointer*/ 563 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 564 #endif 565 return; /* m have already been freed */ 566 } 567 568 /* adjust pointer */ 569 ip6 = mtod(m, struct ip6_hdr *); 570 571 /* 572 * if the payload length field is 0 and the next header field 573 * indicates Hop-by-Hop Options header, then a Jumbo Payload 574 * option MUST be included. 575 */ 576 if (ip6->ip6_plen == 0 && plen == 0) { 577 /* 578 * Note that if a valid jumbo payload option is 579 * contained, ip6_hoptops_input() must set a valid 580 * (non-zero) payload length to the variable plen. 581 */ 582 ip6stat.ip6s_badoptions++; 583 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 584 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 585 icmp6_error(m, ICMP6_PARAM_PROB, 586 ICMP6_PARAMPROB_HEADER, 587 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 588 return; 589 } 590 #ifndef PULLDOWN_TEST 591 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 592 hbh = (struct ip6_hbh *)(ip6 + 1); 593 #else 594 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 595 sizeof(struct ip6_hbh)); 596 if (hbh == NULL) { 597 ip6stat.ip6s_tooshort++; 598 return; 599 } 600 #endif 601 nxt = hbh->ip6h_nxt; 602 603 /* 604 * accept the packet if a router alert option is included 605 * and we act as an IPv6 router. 606 */ 607 if (rtalert != ~0 && ip6_forwarding) 608 ours = 1; 609 } else 610 nxt = ip6->ip6_nxt; 611 612 /* 613 * Check that the amount of data in the buffers 614 * is as at least much as the IPv6 header would have us expect. 615 * Trim mbufs if longer than we expect. 616 * Drop packet if shorter than we expect. 617 */ 618 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 619 ip6stat.ip6s_tooshort++; 620 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 621 goto bad; 622 } 623 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 624 if (m->m_len == m->m_pkthdr.len) { 625 m->m_len = sizeof(struct ip6_hdr) + plen; 626 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 627 } else 628 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 629 } 630 631 /* 632 * Forward if desirable. 633 */ 634 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 635 /* 636 * If we are acting as a multicast router, all 637 * incoming multicast packets are passed to the 638 * kernel-level multicast forwarding function. 639 * The packet is returned (relatively) intact; if 640 * ip6_mforward() returns a non-zero value, the packet 641 * must be discarded, else it may be accepted below. 642 */ 643 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 644 ip6stat.ip6s_cantforward++; 645 m_freem(m); 646 return; 647 } 648 if (!ours) { 649 m_freem(m); 650 return; 651 } 652 } else if (!ours) { 653 ip6_forward(m, 0); 654 return; 655 } 656 657 ip6 = mtod(m, struct ip6_hdr *); 658 659 /* 660 * Malicious party may be able to use IPv4 mapped addr to confuse 661 * tcp/udp stack and bypass security checks (act as if it was from 662 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 663 * 664 * For SIIT end node behavior, you may want to disable the check. 665 * However, you will become vulnerable to attacks using IPv4 mapped 666 * source. 667 */ 668 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 669 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 670 ip6stat.ip6s_badscope++; 671 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 672 goto bad; 673 } 674 675 /* 676 * Tell launch routine the next header 677 */ 678 ip6stat.ip6s_delivered++; 679 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 680 nest = 0; 681 682 while (nxt != IPPROTO_DONE) { 683 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 684 ip6stat.ip6s_toomanyhdr++; 685 goto bad; 686 } 687 688 /* 689 * protection against faulty packet - there should be 690 * more sanity checks in header chain processing. 691 */ 692 if (m->m_pkthdr.len < off) { 693 ip6stat.ip6s_tooshort++; 694 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 695 goto bad; 696 } 697 698 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 699 } 700 return; 701 bad: 702 m_freem(m); 703 } 704 705 /* 706 * Hop-by-Hop options header processing. If a valid jumbo payload option is 707 * included, the real payload length will be stored in plenp. 708 */ 709 static int 710 ip6_hopopts_input(plenp, rtalertp, mp, offp) 711 u_int32_t *plenp; 712 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 713 struct mbuf **mp; 714 int *offp; 715 { 716 struct mbuf *m = *mp; 717 int off = *offp, hbhlen; 718 struct ip6_hbh *hbh; 719 u_int8_t *opt; 720 721 /* validation of the length of the header */ 722 #ifndef PULLDOWN_TEST 723 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 724 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 725 hbhlen = (hbh->ip6h_len + 1) << 3; 726 727 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 728 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 729 #else 730 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 731 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 732 if (hbh == NULL) { 733 ip6stat.ip6s_tooshort++; 734 return -1; 735 } 736 hbhlen = (hbh->ip6h_len + 1) << 3; 737 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 738 hbhlen); 739 if (hbh == NULL) { 740 ip6stat.ip6s_tooshort++; 741 return -1; 742 } 743 #endif 744 off += hbhlen; 745 hbhlen -= sizeof(struct ip6_hbh); 746 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 747 748 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 749 hbhlen, rtalertp, plenp) < 0) 750 return(-1); 751 752 *offp = off; 753 *mp = m; 754 return(0); 755 } 756 757 /* 758 * Search header for all Hop-by-hop options and process each option. 759 * This function is separate from ip6_hopopts_input() in order to 760 * handle a case where the sending node itself process its hop-by-hop 761 * options header. In such a case, the function is called from ip6_output(). 762 */ 763 int 764 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 765 struct mbuf *m; 766 u_int8_t *opthead; 767 int hbhlen; 768 u_int32_t *rtalertp; 769 u_int32_t *plenp; 770 { 771 struct ip6_hdr *ip6; 772 int optlen = 0; 773 u_int8_t *opt = opthead; 774 u_int16_t rtalert_val; 775 u_int32_t jumboplen; 776 777 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 778 switch (*opt) { 779 case IP6OPT_PAD1: 780 optlen = 1; 781 break; 782 case IP6OPT_PADN: 783 if (hbhlen < IP6OPT_MINLEN) { 784 ip6stat.ip6s_toosmall++; 785 goto bad; 786 } 787 optlen = *(opt + 1) + 2; 788 break; 789 case IP6OPT_RTALERT: 790 /* XXX may need check for alignment */ 791 if (hbhlen < IP6OPT_RTALERT_LEN) { 792 ip6stat.ip6s_toosmall++; 793 goto bad; 794 } 795 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) 796 /* XXX: should we discard the packet? */ 797 log(LOG_ERR, "length of router alert opt is inconsitent(%d)", 798 *(opt + 1)); 799 optlen = IP6OPT_RTALERT_LEN; 800 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 801 *rtalertp = ntohs(rtalert_val); 802 break; 803 case IP6OPT_JUMBO: 804 /* XXX may need check for alignment */ 805 if (hbhlen < IP6OPT_JUMBO_LEN) { 806 ip6stat.ip6s_toosmall++; 807 goto bad; 808 } 809 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) 810 /* XXX: should we discard the packet? */ 811 log(LOG_ERR, "length of jumbopayload opt " 812 "is inconsistent(%d)\n", 813 *(opt + 1)); 814 optlen = IP6OPT_JUMBO_LEN; 815 816 /* 817 * IPv6 packets that have non 0 payload length 818 * must not contain a jumbo payload option. 819 */ 820 ip6 = mtod(m, struct ip6_hdr *); 821 if (ip6->ip6_plen) { 822 ip6stat.ip6s_badoptions++; 823 icmp6_error(m, ICMP6_PARAM_PROB, 824 ICMP6_PARAMPROB_HEADER, 825 sizeof(struct ip6_hdr) + 826 sizeof(struct ip6_hbh) + 827 opt - opthead); 828 return(-1); 829 } 830 831 /* 832 * We may see jumbolen in unaligned location, so 833 * we'd need to perform bcopy(). 834 */ 835 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 836 jumboplen = (u_int32_t)htonl(jumboplen); 837 838 #if 1 839 /* 840 * if there are multiple jumbo payload options, 841 * *plenp will be non-zero and the packet will be 842 * rejected. 843 * the behavior may need some debate in ipngwg - 844 * multiple options does not make sense, however, 845 * there's no explicit mention in specification. 846 */ 847 if (*plenp != 0) { 848 ip6stat.ip6s_badoptions++; 849 icmp6_error(m, ICMP6_PARAM_PROB, 850 ICMP6_PARAMPROB_HEADER, 851 sizeof(struct ip6_hdr) + 852 sizeof(struct ip6_hbh) + 853 opt + 2 - opthead); 854 return(-1); 855 } 856 #endif 857 858 /* 859 * jumbo payload length must be larger than 65535. 860 */ 861 if (jumboplen <= IPV6_MAXPACKET) { 862 ip6stat.ip6s_badoptions++; 863 icmp6_error(m, ICMP6_PARAM_PROB, 864 ICMP6_PARAMPROB_HEADER, 865 sizeof(struct ip6_hdr) + 866 sizeof(struct ip6_hbh) + 867 opt + 2 - opthead); 868 return(-1); 869 } 870 *plenp = jumboplen; 871 872 break; 873 default: /* unknown option */ 874 if (hbhlen < IP6OPT_MINLEN) { 875 ip6stat.ip6s_toosmall++; 876 goto bad; 877 } 878 if ((optlen = ip6_unknown_opt(opt, m, 879 sizeof(struct ip6_hdr) + 880 sizeof(struct ip6_hbh) + 881 opt - opthead)) == -1) 882 return(-1); 883 optlen += 2; 884 break; 885 } 886 } 887 888 return(0); 889 890 bad: 891 m_freem(m); 892 return(-1); 893 } 894 895 /* 896 * Unknown option processing. 897 * The third argument `off' is the offset from the IPv6 header to the option, 898 * which is necessary if the IPv6 header the and option header and IPv6 header 899 * is not continuous in order to return an ICMPv6 error. 900 */ 901 int 902 ip6_unknown_opt(optp, m, off) 903 u_int8_t *optp; 904 struct mbuf *m; 905 int off; 906 { 907 struct ip6_hdr *ip6; 908 909 switch (IP6OPT_TYPE(*optp)) { 910 case IP6OPT_TYPE_SKIP: /* ignore the option */ 911 return((int)*(optp + 1)); 912 case IP6OPT_TYPE_DISCARD: /* silently discard */ 913 m_freem(m); 914 return(-1); 915 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 916 ip6stat.ip6s_badoptions++; 917 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 918 return(-1); 919 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 920 ip6stat.ip6s_badoptions++; 921 ip6 = mtod(m, struct ip6_hdr *); 922 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 923 (m->m_flags & (M_BCAST|M_MCAST))) 924 m_freem(m); 925 else 926 icmp6_error(m, ICMP6_PARAM_PROB, 927 ICMP6_PARAMPROB_OPTION, off); 928 return(-1); 929 } 930 931 m_freem(m); /* XXX: NOTREACHED */ 932 return(-1); 933 } 934 935 /* 936 * Create the "control" list for this pcb. 937 * 938 * The routine will be called from upper layer handlers like tcp6_input(). 939 * Thus the routine assumes that the caller (tcp6_input) have already 940 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 941 * very first mbuf on the mbuf chain. 942 * We may want to add some infinite loop prevention or sanity checks for safety. 943 * (This applies only when you are using KAME mbuf chain restriction, i.e. 944 * you are using IP6_EXTHDR_CHECK() not m_pulldown()) 945 */ 946 void 947 ip6_savecontrol(in6p, mp, ip6, m) 948 struct inpcb *in6p; 949 struct mbuf **mp; 950 struct ip6_hdr *ip6; 951 struct mbuf *m; 952 { 953 # define in6p_flags inp_flags 954 int privileged = 0; 955 956 if ((in6p->inp_socket->so_state & SS_PRIV) != 0) 957 privileged++; 958 959 #ifdef SO_TIMESTAMP 960 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 961 struct timeval tv; 962 963 microtime(&tv); 964 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 965 SCM_TIMESTAMP, SOL_SOCKET); 966 if (*mp) 967 mp = &(*mp)->m_next; 968 } 969 #endif 970 if (in6p->in6p_flags & IN6P_RECVDSTADDR) { 971 *mp = sbcreatecontrol((caddr_t) &ip6->ip6_dst, 972 sizeof(struct in6_addr), IPV6_RECVDSTADDR, 973 IPPROTO_IPV6); 974 if (*mp) 975 mp = &(*mp)->m_next; 976 } 977 978 #ifdef noyet 979 /* options were tossed above */ 980 if (in6p->in6p_flags & IN6P_RECVOPTS) 981 /* broken */ 982 /* ip6_srcroute doesn't do what we want here, need to fix */ 983 if (in6p->in6p_flags & IPV6P_RECVRETOPTS) 984 /* broken */ 985 #endif 986 987 /* RFC 2292 sec. 5 */ 988 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 989 struct in6_pktinfo pi6; 990 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 991 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 992 pi6.ipi6_addr.s6_addr16[1] = 0; 993 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 994 ? m->m_pkthdr.rcvif->if_index 995 : 0; 996 *mp = sbcreatecontrol((caddr_t) &pi6, 997 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 998 IPPROTO_IPV6); 999 if (*mp) 1000 mp = &(*mp)->m_next; 1001 } 1002 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1003 int hlim = ip6->ip6_hlim & 0xff; 1004 *mp = sbcreatecontrol((caddr_t) &hlim, 1005 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1006 if (*mp) 1007 mp = &(*mp)->m_next; 1008 } 1009 /* IN6P_NEXTHOP - for outgoing packet only */ 1010 1011 /* 1012 * IPV6_HOPOPTS socket option. We require super-user privilege 1013 * for the option, but it might be too strict, since there might 1014 * be some hop-by-hop options which can be returned to normal user. 1015 * See RFC 2292 section 6. 1016 */ 1017 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { 1018 /* 1019 * Check if a hop-by-hop options header is contatined in the 1020 * received packet, and if so, store the options as ancillary 1021 * data. Note that a hop-by-hop options header must be 1022 * just after the IPv6 header, which fact is assured through 1023 * the IPv6 input processing. 1024 */ 1025 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1026 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1027 struct ip6_hbh *hbh; 1028 int hbhlen; 1029 #ifdef PULLDOWN_TEST 1030 struct mbuf *ext; 1031 #endif 1032 1033 #ifndef PULLDOWN_TEST 1034 hbh = (struct ip6_hbh *)(ip6 + 1); 1035 hbhlen = (hbh->ip6h_len + 1) << 3; 1036 #else 1037 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1038 ip6->ip6_nxt); 1039 if (ext == NULL) { 1040 ip6stat.ip6s_tooshort++; 1041 return; 1042 } 1043 hbh = mtod(ext, struct ip6_hbh *); 1044 hbhlen = (hbh->ip6h_len + 1) << 3; 1045 if (hbhlen != ext->m_len) { 1046 m_freem(ext); 1047 ip6stat.ip6s_tooshort++; 1048 return; 1049 } 1050 #endif 1051 1052 /* 1053 * XXX: We copy whole the header even if a jumbo 1054 * payload option is included, which option is to 1055 * be removed before returning in the RFC 2292. 1056 * But it's too painful operation... 1057 */ 1058 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1059 IPV6_HOPOPTS, IPPROTO_IPV6); 1060 if (*mp) 1061 mp = &(*mp)->m_next; 1062 #ifdef PULLDOWN_TEST 1063 m_freem(ext); 1064 #endif 1065 } 1066 } 1067 1068 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1069 if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) { 1070 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1071 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1072 1073 /* 1074 * Search for destination options headers or routing 1075 * header(s) through the header chain, and stores each 1076 * header as ancillary data. 1077 * Note that the order of the headers remains in 1078 * the chain of ancillary data. 1079 */ 1080 while (1) { /* is explicit loop prevention necessary? */ 1081 struct ip6_ext *ip6e = NULL; 1082 int elen; 1083 #ifdef PULLDOWN_TEST 1084 struct mbuf *ext = NULL; 1085 #endif 1086 1087 /* 1088 * if it is not an extension header, don't try to 1089 * pull it from the chain. 1090 */ 1091 switch (nxt) { 1092 case IPPROTO_DSTOPTS: 1093 case IPPROTO_ROUTING: 1094 case IPPROTO_HOPOPTS: 1095 case IPPROTO_AH: /* is it possible? */ 1096 break; 1097 default: 1098 goto loopend; 1099 } 1100 1101 #ifndef PULLDOWN_TEST 1102 if (off + sizeof(*ip6e) > m->m_len) 1103 goto loopend; 1104 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1105 if (nxt == IPPROTO_AH) 1106 elen = (ip6e->ip6e_len + 2) << 2; 1107 else 1108 elen = (ip6e->ip6e_len + 1) << 3; 1109 if (off + elen > m->m_len) 1110 goto loopend; 1111 #else 1112 ext = ip6_pullexthdr(m, off, nxt); 1113 if (ext == NULL) { 1114 ip6stat.ip6s_tooshort++; 1115 return; 1116 } 1117 ip6e = mtod(ext, struct ip6_ext *); 1118 if (nxt == IPPROTO_AH) 1119 elen = (ip6e->ip6e_len + 2) << 2; 1120 else 1121 elen = (ip6e->ip6e_len + 1) << 3; 1122 if (elen != ext->m_len) { 1123 m_freem(ext); 1124 ip6stat.ip6s_tooshort++; 1125 return; 1126 } 1127 #endif 1128 1129 switch (nxt) { 1130 case IPPROTO_DSTOPTS: 1131 if (!in6p->in6p_flags & IN6P_DSTOPTS) 1132 break; 1133 1134 /* 1135 * We also require super-user privilege for 1136 * the option. 1137 * See the comments on IN6_HOPOPTS. 1138 */ 1139 if (!privileged) 1140 break; 1141 1142 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1143 IPV6_DSTOPTS, 1144 IPPROTO_IPV6); 1145 if (*mp) 1146 mp = &(*mp)->m_next; 1147 break; 1148 1149 case IPPROTO_ROUTING: 1150 if (!in6p->in6p_flags & IN6P_RTHDR) 1151 break; 1152 1153 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1154 IPV6_RTHDR, 1155 IPPROTO_IPV6); 1156 if (*mp) 1157 mp = &(*mp)->m_next; 1158 break; 1159 1160 case IPPROTO_HOPOPTS: 1161 case IPPROTO_AH: /* is it possible? */ 1162 break; 1163 1164 default: 1165 /* 1166 * other cases have been filtered in the above. 1167 * none will visit this case. here we supply 1168 * the code just in case (nxt overwritten or 1169 * other cases). 1170 */ 1171 #ifdef PULLDOWN_TEST 1172 m_freem(ext); 1173 #endif 1174 goto loopend; 1175 1176 } 1177 1178 /* proceed with the next header. */ 1179 off += elen; 1180 nxt = ip6e->ip6e_nxt; 1181 ip6e = NULL; 1182 #ifdef PULLDOWN_TEST 1183 m_freem(ext); 1184 ext = NULL; 1185 #endif 1186 } 1187 loopend: 1188 ; 1189 } 1190 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1191 /* to be done */ 1192 } 1193 if ((in6p->in6p_flags & IN6P_DSTOPTS) && privileged) { 1194 /* to be done */ 1195 } 1196 /* IN6P_RTHDR - to be done */ 1197 # undef in6p_flags 1198 } 1199 1200 #ifdef PULLDOWN_TEST 1201 /* 1202 * pull single extension header from mbuf chain. returns single mbuf that 1203 * contains the result, or NULL on error. 1204 */ 1205 static struct mbuf * 1206 ip6_pullexthdr(m, off, nxt) 1207 struct mbuf *m; 1208 size_t off; 1209 int nxt; 1210 { 1211 struct ip6_ext ip6e; 1212 size_t elen; 1213 struct mbuf *n; 1214 1215 #ifdef DIAGNOSTIC 1216 switch (nxt) { 1217 case IPPROTO_DSTOPTS: 1218 case IPPROTO_ROUTING: 1219 case IPPROTO_HOPOPTS: 1220 case IPPROTO_AH: /* is it possible? */ 1221 break; 1222 default: 1223 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1224 } 1225 #endif 1226 1227 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1228 if (nxt == IPPROTO_AH) 1229 elen = (ip6e.ip6e_len + 2) << 2; 1230 else 1231 elen = (ip6e.ip6e_len + 1) << 3; 1232 1233 MGET(n, M_DONTWAIT, MT_DATA); 1234 if (n && elen >= MLEN) { 1235 MCLGET(n, M_DONTWAIT); 1236 if ((n->m_flags & M_EXT) == 0) { 1237 m_free(n); 1238 n = NULL; 1239 } 1240 } 1241 if (!n) 1242 return NULL; 1243 1244 n->m_len = 0; 1245 if (elen >= M_TRAILINGSPACE(n)) { 1246 m_free(n); 1247 return NULL; 1248 } 1249 1250 m_copydata(m, off, elen, mtod(n, caddr_t)); 1251 n->m_len = elen; 1252 return n; 1253 } 1254 #endif 1255 1256 /* 1257 * Get pointer to the previous header followed by the header 1258 * currently processed. 1259 * XXX: This function supposes that 1260 * M includes all headers, 1261 * the next header field and the header length field of each header 1262 * are valid, and 1263 * the sum of each header length equals to OFF. 1264 * Because of these assumptions, this function must be called very 1265 * carefully. Moreover, it will not be used in the near future when 1266 * we develop `neater' mechanism to process extension headers. 1267 */ 1268 char * 1269 ip6_get_prevhdr(m, off) 1270 struct mbuf *m; 1271 int off; 1272 { 1273 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1274 1275 if (off == sizeof(struct ip6_hdr)) 1276 return(&ip6->ip6_nxt); 1277 else { 1278 int len, nxt; 1279 struct ip6_ext *ip6e = NULL; 1280 1281 nxt = ip6->ip6_nxt; 1282 len = sizeof(struct ip6_hdr); 1283 while (len < off) { 1284 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1285 1286 switch (nxt) { 1287 case IPPROTO_FRAGMENT: 1288 len += sizeof(struct ip6_frag); 1289 break; 1290 case IPPROTO_AH: 1291 len += (ip6e->ip6e_len + 2) << 2; 1292 break; 1293 default: 1294 len += (ip6e->ip6e_len + 1) << 3; 1295 break; 1296 } 1297 nxt = ip6e->ip6e_nxt; 1298 } 1299 if (ip6e) 1300 return(&ip6e->ip6e_nxt); 1301 else 1302 return NULL; 1303 } 1304 } 1305 1306 /* 1307 * get next header offset. m will be retained. 1308 */ 1309 int 1310 ip6_nexthdr(m, off, proto, nxtp) 1311 struct mbuf *m; 1312 int off; 1313 int proto; 1314 int *nxtp; 1315 { 1316 struct ip6_hdr ip6; 1317 struct ip6_ext ip6e; 1318 struct ip6_frag fh; 1319 1320 /* just in case */ 1321 if (m == NULL) 1322 panic("ip6_nexthdr: m == NULL"); 1323 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1324 return -1; 1325 1326 switch (proto) { 1327 case IPPROTO_IPV6: 1328 if (m->m_pkthdr.len < off + sizeof(ip6)) 1329 return -1; 1330 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1331 if (nxtp) 1332 *nxtp = ip6.ip6_nxt; 1333 off += sizeof(ip6); 1334 return off; 1335 1336 case IPPROTO_FRAGMENT: 1337 /* 1338 * terminate parsing if it is not the first fragment, 1339 * it does not make sense to parse through it. 1340 */ 1341 if (m->m_pkthdr.len < off + sizeof(fh)) 1342 return -1; 1343 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1344 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1345 return -1; 1346 if (nxtp) 1347 *nxtp = fh.ip6f_nxt; 1348 off += sizeof(struct ip6_frag); 1349 return off; 1350 1351 case IPPROTO_AH: 1352 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1353 return -1; 1354 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1355 if (nxtp) 1356 *nxtp = ip6e.ip6e_nxt; 1357 off += (ip6e.ip6e_len + 2) << 2; 1358 if (m->m_pkthdr.len < off) 1359 return -1; 1360 return off; 1361 1362 case IPPROTO_HOPOPTS: 1363 case IPPROTO_ROUTING: 1364 case IPPROTO_DSTOPTS: 1365 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1366 return -1; 1367 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1368 if (nxtp) 1369 *nxtp = ip6e.ip6e_nxt; 1370 off += (ip6e.ip6e_len + 1) << 3; 1371 if (m->m_pkthdr.len < off) 1372 return -1; 1373 return off; 1374 1375 case IPPROTO_NONE: 1376 case IPPROTO_ESP: 1377 case IPPROTO_IPCOMP: 1378 /* give up */ 1379 return -1; 1380 1381 default: 1382 return -1; 1383 } 1384 1385 return -1; 1386 } 1387 1388 /* 1389 * get offset for the last header in the chain. m will be kept untainted. 1390 */ 1391 int 1392 ip6_lasthdr(m, off, proto, nxtp) 1393 struct mbuf *m; 1394 int off; 1395 int proto; 1396 int *nxtp; 1397 { 1398 int newoff; 1399 int nxt; 1400 1401 if (!nxtp) { 1402 nxt = -1; 1403 nxtp = &nxt; 1404 } 1405 while (1) { 1406 newoff = ip6_nexthdr(m, off, proto, nxtp); 1407 if (newoff < 0) 1408 return off; 1409 else if (newoff < off) 1410 return -1; /* invalid */ 1411 else if (newoff == off) 1412 return newoff; 1413 1414 off = newoff; 1415 proto = *nxtp; 1416 } 1417 } 1418 1419 /* 1420 * System control for IP6 1421 */ 1422 1423 u_char inet6ctlerrmap[PRC_NCMDS] = { 1424 0, 0, 0, 0, 1425 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1426 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1427 EMSGSIZE, EHOSTUNREACH, 0, 0, 1428 0, 0, 0, 0, 1429 ENOPROTOOPT 1430 }; 1431 1432 #include <uvm/uvm_extern.h> 1433 #include <sys/sysctl.h> 1434 1435 int 1436 ip6_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 1437 int *name; 1438 u_int namelen; 1439 void *oldp; 1440 size_t *oldlenp; 1441 void *newp; 1442 size_t newlen; 1443 { 1444 /* All sysctl names at this level are terminal. */ 1445 if (namelen != 1) 1446 return ENOTDIR; 1447 1448 switch (name[0]) { 1449 1450 case IPV6CTL_FORWARDING: 1451 return sysctl_int(oldp, oldlenp, newp, newlen, 1452 &ip6_forwarding); 1453 case IPV6CTL_SENDREDIRECTS: 1454 return sysctl_int(oldp, oldlenp, newp, newlen, 1455 &ip6_sendredirects); 1456 case IPV6CTL_DEFHLIM: 1457 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_defhlim); 1458 case IPV6CTL_MAXFRAGPACKETS: 1459 return sysctl_int(oldp, oldlenp, newp, newlen, 1460 &ip6_maxfragpackets); 1461 case IPV6CTL_ACCEPT_RTADV: 1462 return sysctl_int(oldp, oldlenp, newp, newlen, 1463 &ip6_accept_rtadv); 1464 case IPV6CTL_KEEPFAITH: 1465 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_keepfaith); 1466 case IPV6CTL_LOG_INTERVAL: 1467 return sysctl_int(oldp, oldlenp, newp, newlen, 1468 &ip6_log_interval); 1469 case IPV6CTL_HDRNESTLIMIT: 1470 return sysctl_int(oldp, oldlenp, newp, newlen, 1471 &ip6_hdrnestlimit); 1472 case IPV6CTL_DAD_COUNT: 1473 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_dad_count); 1474 case IPV6CTL_AUTO_FLOWLABEL: 1475 return sysctl_int(oldp, oldlenp, newp, newlen, 1476 &ip6_auto_flowlabel); 1477 case IPV6CTL_DEFMCASTHLIM: 1478 return sysctl_int(oldp, oldlenp, newp, newlen, 1479 &ip6_defmcasthlim); 1480 case IPV6CTL_KAME_VERSION: 1481 return sysctl_rdstring(oldp, oldlenp, newp, __KAME_VERSION); 1482 case IPV6CTL_USE_DEPRECATED: 1483 return sysctl_int(oldp, oldlenp, newp, newlen, 1484 &ip6_use_deprecated); 1485 case IPV6CTL_RR_PRUNE: 1486 return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_rr_prune); 1487 default: 1488 return EOPNOTSUPP; 1489 } 1490 /* NOTREACHED */ 1491 } 1492