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sys/bsd/netinet6/ip6_input.c
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1 /* $FreeBSD: src/sys/netinet6/ip6_input.c,v 1.11.2.10 2001/07/24 19:10:18 brooks Exp $ */ 2 /* $KAME: ip6_input.c,v 1.194 2001/05/27 13:28:35 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 66 */ 67 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/malloc.h> 72 #include <sys/mbuf.h> 73 #include <sys/domain.h> 74 #include <sys/protosw.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/errno.h> 78 #include <sys/time.h> 79 #include <sys/kernel.h> 80 #include <sys/syslog.h> 81 #include <sys/proc.h> 82 83 #include <net/if.h> 84 #include <net/if_var.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 #if INET 93 #include <netinet/ip.h> 94 #include <netinet/ip_icmp.h> 95 #endif /*INET*/ 96 #include <netinet/ip6.h> 97 #include <netinet6/in6_var.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet/in_pcb.h> 100 #include <netinet/icmp6.h> 101 #include <netinet6/in6_ifattach.h> 102 #include <netinet6/nd6.h> 103 #include <netinet6/in6_prefix.h> 104 105 #if IPSEC 106 #include <netinet6/ipsec.h> 107 #if INET6 108 #include <netinet6/ipsec6.h> 109 #endif 110 extern int ipsec_bypass; 111 #endif 112 113 #include <netinet6/ip6_fw.h> 114 115 #include <netinet6/ip6protosw.h> 116 117 /* we need it for NLOOP. */ 118 #include "loop.h" 119 #include "faith.h" 120 121 #include <net/net_osdep.h> 122 123 extern struct domain inet6domain; 124 extern struct ip6protosw inet6sw[]; 125 126 struct ip6protosw * ip6_protox[IPPROTO_MAX]; 127 static int ip6qmaxlen = IFQ_MAXLEN; 128 struct in6_ifaddr *in6_ifaddr; 129 130 extern void in6_tmpaddrtimer_funneled(void *); 131 extern void nd6_timer_funneled(void *); 132 extern void in6_rr_timer_funneled(void *); 133 134 int ip6_forward_srcrt; /* XXX */ 135 int ip6_sourcecheck; /* XXX */ 136 int ip6_sourcecheck_interval; /* XXX */ 137 const int int6intrq_present = 1; 138 139 int ip6_ours_check_algorithm; 140 int in6_init2done = 0; 141 142 143 /* firewall hooks */ 144 ip6_fw_chk_t *ip6_fw_chk_ptr; 145 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 146 int ip6_fw_enable = 1; 147 148 struct ip6stat ip6stat; 149 150 #ifdef __APPLE__ 151 struct ifqueue ip6intrq; 152 #endif 153 154 static void ip6_init2 __P((void *)); 155 static struct mbuf *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); 156 157 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); 158 #if PULLDOWN_TEST 159 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); 160 #endif 161 162 #ifdef __APPLE__ 163 void gifattach __P((void)); 164 void faithattach __P((void)); 165 void stfattach __P((void)); 166 #endif 167 168 /* 169 * IP6 initialization: fill in IP6 protocol switch table. 170 * All protocols not implemented in kernel go to raw IP6 protocol handler. 171 */ 172 void 173 ip6_init() 174 { 175 struct ip6protosw *pr; 176 int i; 177 struct timeval tv; 178 179 #if DIAGNOSTIC 180 if (sizeof(struct protosw) != sizeof(struct ip6protosw)) 181 panic("sizeof(protosw) != sizeof(ip6protosw)"); 182 #endif 183 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 184 if (pr == 0) 185 panic("ip6_init"); 186 for (i = 0; i < IPPROTO_MAX; i++) 187 ip6_protox[i] = pr; 188 for (pr = (struct ip6protosw*)inet6domain.dom_protosw; pr; pr = pr->pr_next) { 189 if(!((unsigned int)pr->pr_domain)) continue; /* If uninitialized, skip */ 190 if (pr->pr_domain->dom_family == PF_INET6 && 191 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 192 ip6_protox[pr->pr_protocol] = pr; 193 } 194 } 195 196 ip6intrq.ifq_maxlen = ip6qmaxlen; 197 #ifndef __APPLE__ 198 register_netisr(NETISR_IPV6, ip6intr); 199 #endif 200 nd6_init(); 201 frag6_init(); 202 icmp6_init(); 203 /* 204 * in many cases, random() here does NOT return random number 205 * as initialization during bootstrap time occur in fixed order. 206 */ 207 microtime(&tv); 208 ip6_flow_seq = random() ^ tv.tv_usec; 209 microtime(&tv); 210 ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 211 timeout(ip6_init2, (caddr_t)0, 2 * hz); 212 } 213 214 static void 215 ip6_init2(dummy) 216 void *dummy; 217 { 218 #ifdef __APPLE__ 219 boolean_t funnel_state; 220 funnel_state = thread_funnel_set(network_flock, TRUE); 221 #endif 222 /* 223 * to route local address of p2p link to loopback, 224 * assign loopback address first. 225 */ 226 in6_ifattach(&loif[0], NULL, NULL); 227 228 #ifdef __APPLE__ 229 /* nd6_timer_init */ 230 timeout(nd6_timer_funneled, (caddr_t)0, hz); 231 232 /* router renumbering prefix list maintenance */ 233 timeout(in6_rr_timer_funneled, (caddr_t)0, hz); 234 235 /* timer for regeneranation of temporary addresses randomize ID */ 236 timeout(in6_tmpaddrtimer_funneled, (caddr_t)0, 237 (ip6_temp_preferred_lifetime - ip6_desync_factor - 238 ip6_temp_regen_advance) * hz); 239 240 #if NGIF 241 gifattach(); 242 #endif 243 #if NFAITH 244 faithattach(); 245 #endif 246 #if NSTF 247 stfattach(); 248 #endif 249 #else 250 /* nd6_timer_init */ 251 252 callout_init(&nd6_timer_ch); 253 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); 254 255 /* router renumbering prefix list maintenance */ 256 callout_init(&in6_rr_timer_ch); 257 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); 258 259 /* timer for regeneranation of temporary addresses randomize ID */ 260 callout_reset(&in6_tmpaddrtimer_ch, 261 (ip6_temp_preferred_lifetime - ip6_desync_factor - 262 ip6_temp_regen_advance) * hz, 263 in6_tmpaddrtimer, NULL); 264 #endif 265 266 in6_init2done = 1; 267 #ifdef __APPLE__ 268 (void) thread_funnel_set(network_flock, FALSE); 269 #endif 270 } 271 272 #if __FreeBSD__ 273 /* cheat */ 274 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 275 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 276 #endif 277 278 /* 279 * IP6 input interrupt handling. Just pass the packet to ip6_input. 280 */ 281 void 282 ip6intr(void) 283 { 284 int s; 285 struct mbuf *m; 286 287 for (;;) { 288 s = splimp(); 289 IF_DEQUEUE(&ip6intrq, m); 290 splx(s); 291 if (m == 0) 292 return; 293 ip6_input(m); 294 } 295 } 296 297 extern struct route_in6 ip6_forward_rt; 298 299 void 300 ip6_input(m) 301 struct mbuf *m; 302 { 303 struct ip6_hdr *ip6; 304 int off = sizeof(struct ip6_hdr), nest; 305 u_int32_t plen; 306 u_int32_t rtalert = ~0; 307 int nxt = 0, ours = 0; 308 struct ifnet *deliverifp = NULL; 309 310 #if IPSEC 311 /* 312 * should the inner packet be considered authentic? 313 * see comment in ah4_input(). 314 */ 315 if (m) { 316 m->m_flags &= ~M_AUTHIPHDR; 317 m->m_flags &= ~M_AUTHIPDGM; 318 } 319 #endif 320 321 /* 322 * make sure we don't have onion peering information into m_aux. 323 */ 324 ip6_delaux(m); 325 326 /* 327 * mbuf statistics 328 */ 329 if (m->m_flags & M_EXT) { 330 if (m->m_next) 331 ip6stat.ip6s_mext2m++; 332 else 333 ip6stat.ip6s_mext1++; 334 } else { 335 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) 336 if (m->m_next) { 337 if (m->m_flags & M_LOOP) { 338 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ 339 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 340 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 341 else 342 ip6stat.ip6s_m2m[0]++; 343 } else 344 ip6stat.ip6s_m1++; 345 #undef M2MMAX 346 } 347 348 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 349 ip6stat.ip6s_total++; 350 351 #ifndef PULLDOWN_TEST 352 /* 353 * L2 bridge code and some other code can return mbuf chain 354 * that does not conform to KAME requirement. too bad. 355 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 356 */ 357 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 358 struct mbuf *n; 359 360 MGETHDR(n, M_DONTWAIT, MT_HEADER); 361 if (n) 362 M_COPY_PKTHDR(n, m); 363 if (n && m->m_pkthdr.len > MHLEN) { 364 MCLGET(n, M_DONTWAIT); 365 if ((n->m_flags & M_EXT) == 0) { 366 m_freem(n); 367 n = NULL; 368 } 369 } 370 if (n == NULL) { 371 m_freem(m); 372 return; /*ENOBUFS*/ 373 } 374 375 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 376 n->m_len = m->m_pkthdr.len; 377 m_freem(m); 378 m = n; 379 } 380 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); 381 #endif 382 383 if (m->m_len < sizeof(struct ip6_hdr)) { 384 struct ifnet *inifp; 385 inifp = m->m_pkthdr.rcvif; 386 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 387 ip6stat.ip6s_toosmall++; 388 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 389 return; 390 } 391 } 392 393 ip6 = mtod(m, struct ip6_hdr *); 394 395 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 396 ip6stat.ip6s_badvers++; 397 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 398 goto bad; 399 } 400 401 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 402 403 /* 404 * Check with the firewall... 405 */ 406 if (ip6_fw_enable && ip6_fw_chk_ptr) { 407 u_short port = 0; 408 /* If ipfw says divert, we have to just drop packet */ 409 /* use port as a dummy argument */ 410 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 411 m_freem(m); 412 m = NULL; 413 } 414 if (!m) 415 return; 416 } 417 418 /* 419 * Check against address spoofing/corruption. 420 */ 421 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 422 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 423 /* 424 * XXX: "badscope" is not very suitable for a multicast source. 425 */ 426 ip6stat.ip6s_badscope++; 427 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 428 goto bad; 429 } 430 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 431 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 432 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 433 ip6stat.ip6s_badscope++; 434 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 435 goto bad; 436 } 437 438 /* 439 * The following check is not documented in specs. A malicious 440 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 441 * and bypass security checks (act as if it was from 127.0.0.1 by using 442 * IPv6 src ::ffff:127.0.0.1). Be cautious. 443 * 444 * This check chokes if we are in an SIIT cloud. As none of BSDs 445 * support IPv4-less kernel compilation, we cannot support SIIT 446 * environment at all. So, it makes more sense for us to reject any 447 * malicious packets for non-SIIT environment, than try to do a 448 * partical support for SIIT environment. 449 */ 450 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 451 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 452 ip6stat.ip6s_badscope++; 453 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 454 goto bad; 455 } 456 #if 0 457 /* 458 * Reject packets with IPv4 compatible addresses (auto tunnel). 459 * 460 * The code forbids auto tunnel relay case in RFC1933 (the check is 461 * stronger than RFC1933). We may want to re-enable it if mech-xx 462 * is revised to forbid relaying case. 463 */ 464 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 465 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 466 ip6stat.ip6s_badscope++; 467 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 468 goto bad; 469 } 470 #endif 471 472 /* drop packets if interface ID portion is already filled */ 473 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 474 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 475 ip6->ip6_src.s6_addr16[1]) { 476 ip6stat.ip6s_badscope++; 477 goto bad; 478 } 479 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && 480 ip6->ip6_dst.s6_addr16[1]) { 481 ip6stat.ip6s_badscope++; 482 goto bad; 483 } 484 } 485 486 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 487 ip6->ip6_src.s6_addr16[1] 488 = htons(m->m_pkthdr.rcvif->if_index); 489 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 490 ip6->ip6_dst.s6_addr16[1] 491 = htons(m->m_pkthdr.rcvif->if_index); 492 493 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ 494 /* 495 * We use rt->rt_ifp to determine if the address is ours or not. 496 * If rt_ifp is lo0, the address is ours. 497 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, 498 * so any address under fe80::%lo0/64 will be mistakenly considered 499 * local. The special case is supplied to handle the case properly 500 * by actually looking at interface addresses 501 * (using in6ifa_ifpwithaddr). 502 */ 503 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && 504 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { 505 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { 506 icmp6_error(m, ICMP6_DST_UNREACH, 507 ICMP6_DST_UNREACH_ADDR, 0); 508 /* m is already freed */ 509 return; 510 } 511 512 ours = 1; 513 deliverifp = m->m_pkthdr.rcvif; 514 goto hbhcheck; 515 } 516 #endif 517 518 /* 519 * Multicast check 520 */ 521 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 522 struct in6_multi *in6m = 0; 523 524 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 525 /* 526 * See if we belong to the destination multicast group on the 527 * arrival interface. 528 */ 529 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); 530 if (in6m) 531 ours = 1; 532 else if (!ip6_mrouter) { 533 ip6stat.ip6s_notmember++; 534 ip6stat.ip6s_cantforward++; 535 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 536 goto bad; 537 } 538 deliverifp = m->m_pkthdr.rcvif; 539 goto hbhcheck; 540 } 541 542 /* 543 * Unicast check 544 */ 545 switch (ip6_ours_check_algorithm) { 546 default: 547 /* 548 * XXX: I intentionally broke our indentation rule here, 549 * since this switch-case is just for measurement and 550 * therefore should soon be removed. 551 */ 552 if (ip6_forward_rt.ro_rt != NULL && 553 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 554 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 555 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) 556 ip6stat.ip6s_forward_cachehit++; 557 else { 558 struct sockaddr_in6 *dst6; 559 560 if (ip6_forward_rt.ro_rt) { 561 /* route is down or destination is different */ 562 ip6stat.ip6s_forward_cachemiss++; 563 rtfree(ip6_forward_rt.ro_rt); 564 ip6_forward_rt.ro_rt = 0; 565 } 566 567 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 568 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 569 dst6->sin6_len = sizeof(struct sockaddr_in6); 570 dst6->sin6_family = AF_INET6; 571 dst6->sin6_addr = ip6->ip6_dst; 572 #if SCOPEDROUTING 573 ip6_forward_rt.ro_dst.sin6_scope_id = 574 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); 575 #endif 576 577 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 578 } 579 580 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 581 582 /* 583 * Accept the packet if the forwarding interface to the destination 584 * according to the routing table is the loopback interface, 585 * unless the associated route has a gateway. 586 * Note that this approach causes to accept a packet if there is a 587 * route to the loopback interface for the destination of the packet. 588 * But we think it's even useful in some situations, e.g. when using 589 * a special daemon which wants to intercept the packet. 590 * 591 * XXX: some OSes automatically make a cloned route for the destination 592 * of an outgoing packet. If the outgoing interface of the packet 593 * is a loopback one, the kernel would consider the packet to be 594 * accepted, even if we have no such address assinged on the interface. 595 * We check the cloned flag of the route entry to reject such cases, 596 * assuming that route entries for our own addresses are not made by 597 * cloning (it should be true because in6_addloop explicitly installs 598 * the host route). However, we might have to do an explicit check 599 * while it would be less efficient. Or, should we rather install a 600 * reject route for such a case? 601 */ 602 if (ip6_forward_rt.ro_rt && 603 (ip6_forward_rt.ro_rt->rt_flags & 604 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 605 #if RTF_WASCLONED 606 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 607 #endif 608 #if RTF_CLONED 609 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 610 #endif 611 #if 0 612 /* 613 * The check below is redundant since the comparison of 614 * the destination and the key of the rtentry has 615 * already done through looking up the routing table. 616 */ 617 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 618 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 619 #endif 620 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 621 struct in6_ifaddr *ia6 = 622 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 623 624 /* 625 * record address information into m_aux. 626 */ 627 (void)ip6_setdstifaddr(m, ia6); 628 629 /* 630 * packets to a tentative, duplicated, or somehow invalid 631 * address must not be accepted. 632 */ 633 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 634 /* this address is ready */ 635 ours = 1; 636 deliverifp = ia6->ia_ifp; /* correct? */ 637 /* Count the packet in the ip address stats */ 638 #ifndef __APPLE__ 639 640 ia6->ia_ifa.if_ipackets++; 641 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; 642 #endif 643 goto hbhcheck; 644 } else { 645 /* address is not ready, so discard the packet. */ 646 nd6log((LOG_INFO, 647 "ip6_input: packet to an unready address %s->%s\n", 648 ip6_sprintf(&ip6->ip6_src), 649 ip6_sprintf(&ip6->ip6_dst))); 650 651 goto bad; 652 } 653 } 654 } /* XXX indentation (see above) */ 655 656 /* 657 * FAITH(Firewall Aided Internet Translator) 658 */ 659 #if defined(NFAITH) && 0 < NFAITH 660 if (ip6_keepfaith) { 661 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp 662 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { 663 /* XXX do we need more sanity checks? */ 664 ours = 1; 665 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ 666 goto hbhcheck; 667 } 668 } 669 #endif 670 671 /* 672 * Now there is no reason to process the packet if it's not our own 673 * and we're not a router. 674 */ 675 if (!ip6_forwarding) { 676 ip6stat.ip6s_cantforward++; 677 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 678 goto bad; 679 } 680 681 hbhcheck: 682 /* 683 * record address information into m_aux, if we don't have one yet. 684 * note that we are unable to record it, if the address is not listed 685 * as our interface address (e.g. multicast addresses, addresses 686 * within FAITH prefixes and such). 687 */ 688 if (deliverifp && !ip6_getdstifaddr(m)) { 689 struct in6_ifaddr *ia6; 690 691 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 692 if (ia6) { 693 if (!ip6_setdstifaddr(m, ia6)) { 694 /* 695 * XXX maybe we should drop the packet here, 696 * as we could not provide enough information 697 * to the upper layers. 698 */ 699 } 700 } 701 } 702 703 /* 704 * Process Hop-by-Hop options header if it's contained. 705 * m may be modified in ip6_hopopts_input(). 706 * If a JumboPayload option is included, plen will also be modified. 707 */ 708 plen = (u_int32_t)ntohs(ip6->ip6_plen); 709 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 710 struct ip6_hbh *hbh; 711 712 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 713 #if 0 /*touches NULL pointer*/ 714 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 715 #endif 716 return; /* m have already been freed */ 717 } 718 719 /* adjust pointer */ 720 ip6 = mtod(m, struct ip6_hdr *); 721 722 /* 723 * if the payload length field is 0 and the next header field 724 * indicates Hop-by-Hop Options header, then a Jumbo Payload 725 * option MUST be included. 726 */ 727 if (ip6->ip6_plen == 0 && plen == 0) { 728 /* 729 * Note that if a valid jumbo payload option is 730 * contained, ip6_hoptops_input() must set a valid 731 * (non-zero) payload length to the variable plen. 732 */ 733 ip6stat.ip6s_badoptions++; 734 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 735 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 736 icmp6_error(m, ICMP6_PARAM_PROB, 737 ICMP6_PARAMPROB_HEADER, 738 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 739 return; 740 } 741 #ifndef PULLDOWN_TEST 742 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 743 hbh = (struct ip6_hbh *)(ip6 + 1); 744 #else 745 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 746 sizeof(struct ip6_hbh)); 747 if (hbh == NULL) { 748 ip6stat.ip6s_tooshort++; 749 return; 750 } 751 #endif 752 nxt = hbh->ip6h_nxt; 753 754 /* 755 * accept the packet if a router alert option is included 756 * and we act as an IPv6 router. 757 */ 758 if (rtalert != ~0 && ip6_forwarding) 759 ours = 1; 760 } else 761 nxt = ip6->ip6_nxt; 762 763 /* 764 * Check that the amount of data in the buffers 765 * is as at least much as the IPv6 header would have us expect. 766 * Trim mbufs if longer than we expect. 767 * Drop packet if shorter than we expect. 768 */ 769 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 770 ip6stat.ip6s_tooshort++; 771 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 772 goto bad; 773 } 774 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 775 if (m->m_len == m->m_pkthdr.len) { 776 m->m_len = sizeof(struct ip6_hdr) + plen; 777 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 778 } else 779 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 780 } 781 782 /* 783 * Forward if desirable. 784 */ 785 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 786 /* 787 * If we are acting as a multicast router, all 788 * incoming multicast packets are passed to the 789 * kernel-level multicast forwarding function. 790 * The packet is returned (relatively) intact; if 791 * ip6_mforward() returns a non-zero value, the packet 792 * must be discarded, else it may be accepted below. 793 */ 794 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 795 ip6stat.ip6s_cantforward++; 796 m_freem(m); 797 return; 798 } 799 if (!ours) { 800 m_freem(m); 801 return; 802 } 803 } else if (!ours) { 804 ip6_forward(m, 0); 805 return; 806 } 807 808 ip6 = mtod(m, struct ip6_hdr *); 809 810 /* 811 * Malicious party may be able to use IPv4 mapped addr to confuse 812 * tcp/udp stack and bypass security checks (act as if it was from 813 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 814 * 815 * For SIIT end node behavior, you may want to disable the check. 816 * However, you will become vulnerable to attacks using IPv4 mapped 817 * source. 818 */ 819 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 820 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 821 ip6stat.ip6s_badscope++; 822 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 823 goto bad; 824 } 825 826 /* 827 * Tell launch routine the next header 828 */ 829 ip6stat.ip6s_delivered++; 830 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 831 nest = 0; 832 833 while (nxt != IPPROTO_DONE) { 834 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 835 ip6stat.ip6s_toomanyhdr++; 836 goto bad; 837 } 838 839 /* 840 * protection against faulty packet - there should be 841 * more sanity checks in header chain processing. 842 */ 843 if (m->m_pkthdr.len < off) { 844 ip6stat.ip6s_tooshort++; 845 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 846 goto bad; 847 } 848 849 #if 0 850 /* 851 * do we need to do it for every header? yeah, other 852 * functions can play with it (like re-allocate and copy). 853 */ 854 mhist = ip6_addaux(m); 855 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 856 hist = mtod(mhist, caddr_t) + mhist->m_len; 857 bcopy(&nxt, hist, sizeof(nxt)); 858 mhist->m_len += sizeof(nxt); 859 } else { 860 ip6stat.ip6s_toomanyhdr++; 861 goto bad; 862 } 863 #endif 864 865 #if IPSEC 866 /* 867 * enforce IPsec policy checking if we are seeing last header. 868 * note that we do not visit this with protocols with pcb layer 869 * code - like udp/tcp/raw ip. 870 */ 871 if ((ipsec_bypass == 0) && (ip6_protox[nxt]->pr_flags & PR_LASTHDR) != 0 && 872 ipsec6_in_reject(m, NULL)) { 873 ipsec6stat.in_polvio++; 874 goto bad; 875 } 876 #endif 877 878 nxt = (*ip6_protox[nxt]->pr_input)(&m, &off); 879 } 880 return; 881 bad: 882 m_freem(m); 883 } 884 885 /* 886 * set/grab in6_ifaddr correspond to IPv6 destination address. 887 * XXX backward compatibility wrapper 888 */ 889 static struct mbuf * 890 ip6_setdstifaddr(m, ia6) 891 struct mbuf *m; 892 struct in6_ifaddr *ia6; 893 { 894 struct mbuf *n; 895 896 n = ip6_addaux(m); 897 if (n) 898 mtod(n, struct ip6aux *)->ip6a_dstia6 = ia6; 899 return n; /* NULL if failed to set */ 900 } 901 902 struct in6_ifaddr * 903 ip6_getdstifaddr(m) 904 struct mbuf *m; 905 { 906 struct mbuf *n; 907 908 n = ip6_findaux(m); 909 if (n) 910 return mtod(n, struct ip6aux *)->ip6a_dstia6; 911 else 912 return NULL; 913 } 914 915 /* 916 * Hop-by-Hop options header processing. If a valid jumbo payload option is 917 * included, the real payload length will be stored in plenp. 918 */ 919 static int 920 ip6_hopopts_input(plenp, rtalertp, mp, offp) 921 u_int32_t *plenp; 922 u_int32_t *rtalertp; /* XXX: should be stored more smart way */ 923 struct mbuf **mp; 924 int *offp; 925 { 926 struct mbuf *m = *mp; 927 int off = *offp, hbhlen; 928 struct ip6_hbh *hbh; 929 u_int8_t *opt; 930 931 /* validation of the length of the header */ 932 #ifndef PULLDOWN_TEST 933 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 934 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 935 hbhlen = (hbh->ip6h_len + 1) << 3; 936 937 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 938 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 939 #else 940 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 941 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 942 if (hbh == NULL) { 943 ip6stat.ip6s_tooshort++; 944 return -1; 945 } 946 hbhlen = (hbh->ip6h_len + 1) << 3; 947 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 948 hbhlen); 949 if (hbh == NULL) { 950 ip6stat.ip6s_tooshort++; 951 return -1; 952 } 953 #endif 954 off += hbhlen; 955 hbhlen -= sizeof(struct ip6_hbh); 956 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); 957 958 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 959 hbhlen, rtalertp, plenp) < 0) 960 return(-1); 961 962 *offp = off; 963 *mp = m; 964 return(0); 965 } 966 967 /* 968 * Search header for all Hop-by-hop options and process each option. 969 * This function is separate from ip6_hopopts_input() in order to 970 * handle a case where the sending node itself process its hop-by-hop 971 * options header. In such a case, the function is called from ip6_output(). 972 * 973 * The function assumes that hbh header is located right after the IPv6 header 974 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 975 * opthead + hbhlen is located in continuous memory region. 976 */ 977 int 978 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) 979 struct mbuf *m; 980 u_int8_t *opthead; 981 int hbhlen; 982 u_int32_t *rtalertp; 983 u_int32_t *plenp; 984 { 985 struct ip6_hdr *ip6; 986 int optlen = 0; 987 u_int8_t *opt = opthead; 988 u_int16_t rtalert_val; 989 u_int32_t jumboplen; 990 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 991 992 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 993 switch (*opt) { 994 case IP6OPT_PAD1: 995 optlen = 1; 996 break; 997 case IP6OPT_PADN: 998 if (hbhlen < IP6OPT_MINLEN) { 999 ip6stat.ip6s_toosmall++; 1000 goto bad; 1001 } 1002 optlen = *(opt + 1) + 2; 1003 break; 1004 case IP6OPT_RTALERT: 1005 /* XXX may need check for alignment */ 1006 if (hbhlen < IP6OPT_RTALERT_LEN) { 1007 ip6stat.ip6s_toosmall++; 1008 goto bad; 1009 } 1010 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 1011 /* XXX stat */ 1012 icmp6_error(m, ICMP6_PARAM_PROB, 1013 ICMP6_PARAMPROB_HEADER, 1014 erroff + opt + 1 - opthead); 1015 return(-1); 1016 } 1017 optlen = IP6OPT_RTALERT_LEN; 1018 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1019 *rtalertp = ntohs(rtalert_val); 1020 break; 1021 case IP6OPT_JUMBO: 1022 /* XXX may need check for alignment */ 1023 if (hbhlen < IP6OPT_JUMBO_LEN) { 1024 ip6stat.ip6s_toosmall++; 1025 goto bad; 1026 } 1027 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1028 /* XXX stat */ 1029 icmp6_error(m, ICMP6_PARAM_PROB, 1030 ICMP6_PARAMPROB_HEADER, 1031 erroff + opt + 1 - opthead); 1032 return(-1); 1033 } 1034 optlen = IP6OPT_JUMBO_LEN; 1035 1036 /* 1037 * IPv6 packets that have non 0 payload length 1038 * must not contain a jumbo payload option. 1039 */ 1040 ip6 = mtod(m, struct ip6_hdr *); 1041 if (ip6->ip6_plen) { 1042 ip6stat.ip6s_badoptions++; 1043 icmp6_error(m, ICMP6_PARAM_PROB, 1044 ICMP6_PARAMPROB_HEADER, 1045 erroff + opt - opthead); 1046 return(-1); 1047 } 1048 1049 /* 1050 * We may see jumbolen in unaligned location, so 1051 * we'd need to perform bcopy(). 1052 */ 1053 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1054 jumboplen = (u_int32_t)htonl(jumboplen); 1055 1056 #if 1 1057 /* 1058 * if there are multiple jumbo payload options, 1059 * *plenp will be non-zero and the packet will be 1060 * rejected. 1061 * the behavior may need some debate in ipngwg - 1062 * multiple options does not make sense, however, 1063 * there's no explicit mention in specification. 1064 */ 1065 if (*plenp != 0) { 1066 ip6stat.ip6s_badoptions++; 1067 icmp6_error(m, ICMP6_PARAM_PROB, 1068 ICMP6_PARAMPROB_HEADER, 1069 erroff + opt + 2 - opthead); 1070 return(-1); 1071 } 1072 #endif 1073 1074 /* 1075 * jumbo payload length must be larger than 65535. 1076 */ 1077 if (jumboplen <= IPV6_MAXPACKET) { 1078 ip6stat.ip6s_badoptions++; 1079 icmp6_error(m, ICMP6_PARAM_PROB, 1080 ICMP6_PARAMPROB_HEADER, 1081 erroff + opt + 2 - opthead); 1082 return(-1); 1083 } 1084 *plenp = jumboplen; 1085 1086 break; 1087 default: /* unknown option */ 1088 if (hbhlen < IP6OPT_MINLEN) { 1089 ip6stat.ip6s_toosmall++; 1090 goto bad; 1091 } 1092 optlen = ip6_unknown_opt(opt, m, 1093 erroff + opt - opthead); 1094 if (optlen == -1) 1095 return(-1); 1096 optlen += 2; 1097 break; 1098 } 1099 } 1100 1101 return(0); 1102 1103 bad: 1104 m_freem(m); 1105 return(-1); 1106 } 1107 1108 /* 1109 * Unknown option processing. 1110 * The third argument `off' is the offset from the IPv6 header to the option, 1111 * which is necessary if the IPv6 header the and option header and IPv6 header 1112 * is not continuous in order to return an ICMPv6 error. 1113 */ 1114 int 1115 ip6_unknown_opt(optp, m, off) 1116 u_int8_t *optp; 1117 struct mbuf *m; 1118 int off; 1119 { 1120 struct ip6_hdr *ip6; 1121 1122 switch (IP6OPT_TYPE(*optp)) { 1123 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1124 return((int)*(optp + 1)); 1125 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1126 m_freem(m); 1127 return(-1); 1128 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1129 ip6stat.ip6s_badoptions++; 1130 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1131 return(-1); 1132 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1133 ip6stat.ip6s_badoptions++; 1134 ip6 = mtod(m, struct ip6_hdr *); 1135 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1136 (m->m_flags & (M_BCAST|M_MCAST))) 1137 m_freem(m); 1138 else 1139 icmp6_error(m, ICMP6_PARAM_PROB, 1140 ICMP6_PARAMPROB_OPTION, off); 1141 return(-1); 1142 } 1143 1144 m_freem(m); /* XXX: NOTREACHED */ 1145 return(-1); 1146 } 1147 1148 /* 1149 * Create the "control" list for this pcb. 1150 * The function will not modify mbuf chain at all. 1151 * 1152 * with KAME mbuf chain restriction: 1153 * The routine will be called from upper layer handlers like tcp6_input(). 1154 * Thus the routine assumes that the caller (tcp6_input) have already 1155 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1156 * very first mbuf on the mbuf chain. 1157 */ 1158 void 1159 ip6_savecontrol(in6p, mp, ip6, m) 1160 struct inpcb *in6p; 1161 struct mbuf **mp; 1162 struct ip6_hdr *ip6; 1163 struct mbuf *m; 1164 { 1165 struct proc *p = current_proc(); /* XXX */ 1166 int privileged = 0; 1167 int rthdr_exist = 0; 1168 1169 #ifdef __APPLE__ 1170 if (p && !suser(p->p_ucred, &p->p_acflag)) 1171 #else 1172 if (p && !suser(p)) 1173 #endif 1174 privileged++; 1175 1176 #if SO_TIMESTAMP 1177 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { 1178 struct timeval tv; 1179 1180 microtime(&tv); 1181 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1182 SCM_TIMESTAMP, SOL_SOCKET); 1183 if (*mp) { 1184 mp = &(*mp)->m_next; 1185 } 1186 } 1187 #endif 1188 1189 /* RFC 2292 sec. 5 */ 1190 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { 1191 struct in6_pktinfo pi6; 1192 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1193 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) 1194 pi6.ipi6_addr.s6_addr16[1] = 0; 1195 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) 1196 ? m->m_pkthdr.rcvif->if_index 1197 : 0; 1198 *mp = sbcreatecontrol((caddr_t) &pi6, 1199 sizeof(struct in6_pktinfo), IPV6_PKTINFO, 1200 IPPROTO_IPV6); 1201 if (*mp) 1202 mp = &(*mp)->m_next; 1203 } 1204 1205 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { 1206 int hlim = ip6->ip6_hlim & 0xff; 1207 *mp = sbcreatecontrol((caddr_t) &hlim, 1208 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); 1209 if (*mp) 1210 mp = &(*mp)->m_next; 1211 } 1212 1213 /* 1214 * IPV6_HOPOPTS socket option. We require super-user privilege 1215 * for the option, but it might be too strict, since there might 1216 * be some hop-by-hop options which can be returned to normal user. 1217 * See RFC 2292 section 6. 1218 */ 1219 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { 1220 /* 1221 * Check if a hop-by-hop options header is contatined in the 1222 * received packet, and if so, store the options as ancillary 1223 * data. Note that a hop-by-hop options header must be 1224 * just after the IPv6 header, which fact is assured through 1225 * the IPv6 input processing. 1226 */ 1227 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1228 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1229 struct ip6_hbh *hbh; 1230 int hbhlen = 0; 1231 #if PULLDOWN_TEST 1232 struct mbuf *ext; 1233 #endif 1234 1235 #ifndef PULLDOWN_TEST 1236 hbh = (struct ip6_hbh *)(ip6 + 1); 1237 hbhlen = (hbh->ip6h_len + 1) << 3; 1238 #else 1239 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1240 ip6->ip6_nxt); 1241 if (ext == NULL) { 1242 ip6stat.ip6s_tooshort++; 1243 return; 1244 } 1245 hbh = mtod(ext, struct ip6_hbh *); 1246 hbhlen = (hbh->ip6h_len + 1) << 3; 1247 if (hbhlen != ext->m_len) { 1248 m_freem(ext); 1249 ip6stat.ip6s_tooshort++; 1250 return; 1251 } 1252 #endif 1253 1254 /* 1255 * XXX: We copy whole the header even if a jumbo 1256 * payload option is included, which option is to 1257 * be removed before returning in the RFC 2292. 1258 * Note: this constraint is removed in 2292bis. 1259 */ 1260 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1261 IPV6_HOPOPTS, IPPROTO_IPV6); 1262 if (*mp) 1263 mp = &(*mp)->m_next; 1264 #if PULLDOWN_TEST 1265 m_freem(ext); 1266 #endif 1267 } 1268 } 1269 1270 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1271 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1272 int proto, off, nxt; 1273 1274 /* 1275 * go through the header chain to see if a routing header is 1276 * contained in the packet. We need this information to store 1277 * destination options headers (if any) properly. 1278 * XXX: performance issue. We should record this info when 1279 * processing extension headers in incoming routine. 1280 * (todo) use m_aux? 1281 */ 1282 proto = IPPROTO_IPV6; 1283 off = 0; 1284 nxt = -1; 1285 while (1) { 1286 int newoff; 1287 1288 newoff = ip6_nexthdr(m, off, proto, &nxt); 1289 if (newoff < 0) 1290 break; 1291 if (newoff < off) /* invalid, check for safety */ 1292 break; 1293 if ((proto = nxt) == IPPROTO_ROUTING) { 1294 rthdr_exist = 1; 1295 break; 1296 } 1297 off = newoff; 1298 } 1299 } 1300 1301 if ((in6p->in6p_flags & 1302 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1303 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1304 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1305 1306 /* 1307 * Search for destination options headers or routing 1308 * header(s) through the header chain, and stores each 1309 * header as ancillary data. 1310 * Note that the order of the headers remains in 1311 * the chain of ancillary data. 1312 */ 1313 while (1) { /* is explicit loop prevention necessary? */ 1314 struct ip6_ext *ip6e = NULL; 1315 int elen; 1316 #if PULLDOWN_TEST 1317 struct mbuf *ext = NULL; 1318 #endif 1319 1320 /* 1321 * if it is not an extension header, don't try to 1322 * pull it from the chain. 1323 */ 1324 switch (nxt) { 1325 case IPPROTO_DSTOPTS: 1326 case IPPROTO_ROUTING: 1327 case IPPROTO_HOPOPTS: 1328 case IPPROTO_AH: /* is it possible? */ 1329 break; 1330 default: 1331 goto loopend; 1332 } 1333 1334 #ifndef PULLDOWN_TEST 1335 if (off + sizeof(*ip6e) > m->m_len) 1336 goto loopend; 1337 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1338 if (nxt == IPPROTO_AH) 1339 elen = (ip6e->ip6e_len + 2) << 2; 1340 else 1341 elen = (ip6e->ip6e_len + 1) << 3; 1342 if (off + elen > m->m_len) 1343 goto loopend; 1344 #else 1345 ext = ip6_pullexthdr(m, off, nxt); 1346 if (ext == NULL) { 1347 ip6stat.ip6s_tooshort++; 1348 return; 1349 } 1350 ip6e = mtod(ext, struct ip6_ext *); 1351 if (nxt == IPPROTO_AH) 1352 elen = (ip6e->ip6e_len + 2) << 2; 1353 else 1354 elen = (ip6e->ip6e_len + 1) << 3; 1355 if (elen != ext->m_len) { 1356 m_freem(ext); 1357 ip6stat.ip6s_tooshort++; 1358 return; 1359 } 1360 #endif 1361 1362 switch (nxt) { 1363 case IPPROTO_DSTOPTS: 1364 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1365 break; 1366 1367 /* 1368 * We also require super-user privilege for 1369 * the option. 1370 * See the comments on IN6_HOPOPTS. 1371 */ 1372 if (!privileged) 1373 break; 1374 1375 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1376 IPV6_DSTOPTS, 1377 IPPROTO_IPV6); 1378 if (*mp) 1379 mp = &(*mp)->m_next; 1380 break; 1381 case IPPROTO_ROUTING: 1382 if (!in6p->in6p_flags & IN6P_RTHDR) 1383 break; 1384 1385 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1386 IPV6_RTHDR, 1387 IPPROTO_IPV6); 1388 if (*mp) 1389 mp = &(*mp)->m_next; 1390 break; 1391 case IPPROTO_HOPOPTS: 1392 case IPPROTO_AH: /* is it possible? */ 1393 break; 1394 1395 default: 1396 /* 1397 * other cases have been filtered in the above. 1398 * none will visit this case. here we supply 1399 * the code just in case (nxt overwritten or 1400 * other cases). 1401 */ 1402 #if PULLDOWN_TEST 1403 m_freem(ext); 1404 #endif 1405 goto loopend; 1406 1407 } 1408 1409 /* proceed with the next header. */ 1410 off += elen; 1411 nxt = ip6e->ip6e_nxt; 1412 ip6e = NULL; 1413 #if PULLDOWN_TEST 1414 m_freem(ext); 1415 ext = NULL; 1416 #endif 1417 } 1418 loopend: 1419 ; 1420 } 1421 1422 } 1423 1424 #if PULLDOWN_TEST 1425 /* 1426 * pull single extension header from mbuf chain. returns single mbuf that 1427 * contains the result, or NULL on error. 1428 */ 1429 static struct mbuf * 1430 ip6_pullexthdr(m, off, nxt) 1431 struct mbuf *m; 1432 size_t off; 1433 int nxt; 1434 { 1435 struct ip6_ext ip6e; 1436 size_t elen; 1437 struct mbuf *n; 1438 1439 #if DIAGNOSTIC 1440 switch (nxt) { 1441 case IPPROTO_DSTOPTS: 1442 case IPPROTO_ROUTING: 1443 case IPPROTO_HOPOPTS: 1444 case IPPROTO_AH: /* is it possible? */ 1445 break; 1446 default: 1447 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1448 } 1449 #endif 1450 1451 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1452 if (nxt == IPPROTO_AH) 1453 elen = (ip6e.ip6e_len + 2) << 2; 1454 else 1455 elen = (ip6e.ip6e_len + 1) << 3; 1456 1457 MGET(n, M_DONTWAIT, MT_DATA); 1458 if (n && elen >= MLEN) { 1459 MCLGET(n, M_DONTWAIT); 1460 if ((n->m_flags & M_EXT) == 0) { 1461 m_free(n); 1462 n = NULL; 1463 } 1464 } 1465 if (!n) 1466 return NULL; 1467 1468 n->m_len = 0; 1469 if (elen >= M_TRAILINGSPACE(n)) { 1470 m_free(n); 1471 return NULL; 1472 } 1473 1474 m_copydata(m, off, elen, mtod(n, caddr_t)); 1475 n->m_len = elen; 1476 return n; 1477 } 1478 #endif 1479 1480 /* 1481 * Get pointer to the previous header followed by the header 1482 * currently processed. 1483 * XXX: This function supposes that 1484 * M includes all headers, 1485 * the next header field and the header length field of each header 1486 * are valid, and 1487 * the sum of each header length equals to OFF. 1488 * Because of these assumptions, this function must be called very 1489 * carefully. Moreover, it will not be used in the near future when 1490 * we develop `neater' mechanism to process extension headers. 1491 */ 1492 char * 1493 ip6_get_prevhdr(m, off) 1494 struct mbuf *m; 1495 int off; 1496 { 1497 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1498 1499 if (off == sizeof(struct ip6_hdr)) 1500 return(&ip6->ip6_nxt); 1501 else { 1502 int len, nxt; 1503 struct ip6_ext *ip6e = NULL; 1504 1505 nxt = ip6->ip6_nxt; 1506 len = sizeof(struct ip6_hdr); 1507 while (len < off) { 1508 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1509 1510 switch (nxt) { 1511 case IPPROTO_FRAGMENT: 1512 len += sizeof(struct ip6_frag); 1513 break; 1514 case IPPROTO_AH: 1515 len += (ip6e->ip6e_len + 2) << 2; 1516 break; 1517 default: 1518 len += (ip6e->ip6e_len + 1) << 3; 1519 break; 1520 } 1521 nxt = ip6e->ip6e_nxt; 1522 } 1523 if (ip6e) 1524 return(&ip6e->ip6e_nxt); 1525 else 1526 return NULL; 1527 } 1528 } 1529 1530 /* 1531 * get next header offset. m will be retained. 1532 */ 1533 int 1534 ip6_nexthdr(m, off, proto, nxtp) 1535 struct mbuf *m; 1536 int off; 1537 int proto; 1538 int *nxtp; 1539 { 1540 struct ip6_hdr ip6; 1541 struct ip6_ext ip6e; 1542 struct ip6_frag fh; 1543 1544 /* just in case */ 1545 if (m == NULL) 1546 panic("ip6_nexthdr: m == NULL"); 1547 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1548 return -1; 1549 1550 switch (proto) { 1551 case IPPROTO_IPV6: 1552 if (m->m_pkthdr.len < off + sizeof(ip6)) 1553 return -1; 1554 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1555 if (nxtp) 1556 *nxtp = ip6.ip6_nxt; 1557 off += sizeof(ip6); 1558 return off; 1559 1560 case IPPROTO_FRAGMENT: 1561 /* 1562 * terminate parsing if it is not the first fragment, 1563 * it does not make sense to parse through it. 1564 */ 1565 if (m->m_pkthdr.len < off + sizeof(fh)) 1566 return -1; 1567 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1568 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) 1569 return -1; 1570 if (nxtp) 1571 *nxtp = fh.ip6f_nxt; 1572 off += sizeof(struct ip6_frag); 1573 return off; 1574 1575 case IPPROTO_AH: 1576 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1577 return -1; 1578 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1579 if (nxtp) 1580 *nxtp = ip6e.ip6e_nxt; 1581 off += (ip6e.ip6e_len + 2) << 2; 1582 return off; 1583 1584 case IPPROTO_HOPOPTS: 1585 case IPPROTO_ROUTING: 1586 case IPPROTO_DSTOPTS: 1587 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1588 return -1; 1589 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1590 if (nxtp) 1591 *nxtp = ip6e.ip6e_nxt; 1592 off += (ip6e.ip6e_len + 1) << 3; 1593 return off; 1594 1595 case IPPROTO_NONE: 1596 case IPPROTO_ESP: 1597 case IPPROTO_IPCOMP: 1598 /* give up */ 1599 return -1; 1600 1601 default: 1602 return -1; 1603 } 1604 1605 return -1; 1606 } 1607 1608 /* 1609 * get offset for the last header in the chain. m will be kept untainted. 1610 */ 1611 int 1612 ip6_lasthdr(m, off, proto, nxtp) 1613 struct mbuf *m; 1614 int off; 1615 int proto; 1616 int *nxtp; 1617 { 1618 int newoff; 1619 int nxt; 1620 1621 if (!nxtp) { 1622 nxt = -1; 1623 nxtp = &nxt; 1624 } 1625 while (1) { 1626 newoff = ip6_nexthdr(m, off, proto, nxtp); 1627 if (newoff < 0) 1628 return off; 1629 else if (newoff < off) 1630 return -1; /* invalid */ 1631 else if (newoff == off) 1632 return newoff; 1633 1634 off = newoff; 1635 proto = *nxtp; 1636 } 1637 } 1638 1639 struct mbuf * 1640 ip6_addaux(m) 1641 struct mbuf *m; 1642 { 1643 struct mbuf *n; 1644 1645 #if DIAGNOSTIC 1646 if (sizeof(struct ip6aux) > MHLEN) 1647 panic("assumption failed on sizeof(ip6aux)"); 1648 #endif 1649 n = m_aux_find(m, AF_INET6, -1); 1650 if (n) { 1651 if (n->m_len < sizeof(struct ip6aux)) { 1652 printf("conflicting use of ip6aux"); 1653 return NULL; 1654 } 1655 } else { 1656 n = m_aux_add(m, AF_INET6, -1); 1657 if (n) { 1658 n->m_len = sizeof(struct ip6aux); 1659 bzero(mtod(n, caddr_t), n->m_len); 1660 } 1661 } 1662 return n; 1663 } 1664 1665 struct mbuf * 1666 ip6_findaux(m) 1667 struct mbuf *m; 1668 { 1669 struct mbuf *n; 1670 1671 n = m_aux_find(m, AF_INET6, -1); 1672 if (n && n->m_len < sizeof(struct ip6aux)) { 1673 printf("conflicting use of ip6aux"); 1674 n = NULL; 1675 } 1676 return n; 1677 } 1678 1679 void 1680 ip6_delaux(m) 1681 struct mbuf *m; 1682 { 1683 struct mbuf *n; 1684 1685 n = m_aux_find(m, AF_INET6, -1); 1686 if (n) 1687 m_aux_delete(m, n); 1688 } 1689 1690 /* 1691 * System control for IP6 1692 */ 1693 1694 u_char inet6ctlerrmap[PRC_NCMDS] = { 1695 0, 0, 0, 0, 1696 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1697 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1698 EMSGSIZE, EHOSTUNREACH, 0, 0, 1699 0, 0, 0, 0, 1700 ENOPROTOOPT 1701 };
Cache object: 35943471aa1c1017c0bafe18b824ad6e
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