1 /* $FreeBSD: src/sys/netinet6/ip6_input.c,v 1.11.2.15 2003/01/24 05:11:35 sam Exp $ */ 2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include "opt_ip6fw.h" 65 #include "opt_inet.h" 66 #include "opt_inet6.h" 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/malloc.h> 71 #include <sys/mbuf.h> 72 #include <sys/domain.h> 73 #include <sys/protosw.h> 74 #include <sys/socket.h> 75 #include <sys/socketvar.h> 76 #include <sys/errno.h> 77 #include <sys/time.h> 78 #include <sys/kernel.h> 79 #include <sys/syslog.h> 80 #include <sys/proc.h> 81 #include <sys/priv.h> 82 83 #include <net/if.h> 84 #include <net/if_types.h> 85 #include <net/if_dl.h> 86 #include <net/route.h> 87 #include <net/netisr.h> 88 #include <net/pfil.h> 89 90 #include <sys/msgport2.h> 91 #include <net/netmsg2.h> 92 #include <net/netisr2.h> 93 94 #include <netinet/in.h> 95 #include <netinet/in_systm.h> 96 #ifdef INET 97 #include <netinet/ip.h> 98 #include <netinet/ip_icmp.h> 99 #endif /* INET */ 100 #include <netinet/ip6.h> 101 #include <netinet6/in6_var.h> 102 #include <netinet6/ip6_var.h> 103 #include <netinet/in_pcb.h> 104 #include <netinet/icmp6.h> 105 #include <netinet6/scope6_var.h> 106 #include <netinet6/in6_ifattach.h> 107 #include <netinet6/nd6.h> 108 109 #include <net/ip6fw/ip6_fw.h> 110 111 #include <netinet6/ip6protosw.h> 112 113 #include <net/net_osdep.h> 114 115 extern struct domain inet6domain; 116 extern struct protosw inet6sw[]; 117 118 u_char ip6_protox[IPPROTO_MAX]; 119 struct in6_ifaddr *in6_ifaddr; 120 121 int ip6_forward_srcrt; /* XXX */ 122 int ip6_sourcecheck; /* XXX */ 123 int ip6_sourcecheck_interval; /* XXX */ 124 125 int ip6_ours_check_algorithm; 126 127 struct pfil_head inet6_pfil_hook; 128 129 /* firewall hooks */ 130 ip6_fw_chk_t *ip6_fw_chk_ptr; 131 ip6_fw_ctl_t *ip6_fw_ctl_ptr; 132 int ip6_fw_enable = 1; 133 134 struct ip6stat ip6stat; 135 136 static void ip6_init2 (void *); 137 static struct ip6aux *ip6_setdstifaddr (struct mbuf *, struct in6_ifaddr *); 138 static int ip6_hopopts_input (u_int32_t *, u_int32_t *, struct mbuf **, int *); 139 static void ip6_input(netmsg_t msg); 140 #ifdef PULLDOWN_TEST 141 static struct mbuf *ip6_pullexthdr (struct mbuf *, size_t, int); 142 #endif 143 static void transport6_processing_handler(netmsg_t netmsg); 144 145 /* 146 * IP6 initialization: fill in IP6 protocol switch table. 147 * All protocols not implemented in kernel go to raw IP6 protocol handler. 148 */ 149 void 150 ip6_init(void) 151 { 152 struct protosw *pr; 153 int i; 154 struct timeval tv; 155 156 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 157 if (pr == NULL) 158 panic("ip6_init"); 159 for (i = 0; i < IPPROTO_MAX; i++) 160 ip6_protox[i] = pr - inet6sw; 161 for (pr = inet6domain.dom_protosw; 162 pr < inet6domain.dom_protoswNPROTOSW; pr++) 163 if (pr->pr_domain->dom_family == PF_INET6 && 164 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) 165 ip6_protox[pr->pr_protocol] = pr - inet6sw; 166 167 inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 168 inet6_pfil_hook.ph_af = AF_INET6; 169 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) { 170 kprintf("%s: WARNING: unable to register pfil hook, " 171 "error %d\n", __func__, i); 172 } 173 174 netisr_register(NETISR_IPV6, ip6_input, NULL); /* XXX hashfn */ 175 scope6_init(); 176 addrsel_policy_init(); 177 nd6_init(); 178 frag6_init(); 179 /* 180 * in many cases, random() here does NOT return random number 181 * as initialization during bootstrap time occur in fixed order. 182 */ 183 microtime(&tv); 184 ip6_flow_seq = krandom() ^ tv.tv_usec; 185 microtime(&tv); 186 ip6_desync_factor = (krandom() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; 187 } 188 189 static void 190 ip6_init2(void *dummy) 191 { 192 nd6_timer_init(); 193 in6_tmpaddrtimer_init(); 194 } 195 196 /* cheat */ 197 /* This must be after route_init(), which is now SI_ORDER_THIRD */ 198 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); 199 200 extern struct route_in6 ip6_forward_rt; 201 202 static void 203 ip6_input(netmsg_t msg) 204 { 205 struct mbuf *m = msg->packet.nm_packet; 206 struct ip6_hdr *ip6; 207 int off = sizeof(struct ip6_hdr), nest; 208 u_int32_t plen; 209 u_int32_t rtalert = ~0; 210 int nxt, ours = 0, rh_present = 0; 211 struct ifnet *deliverifp = NULL; 212 struct in6_addr odst; 213 int srcrt = 0; 214 215 /* 216 * make sure we don't have onion peering information into m_aux. 217 */ 218 ip6_delaux(m); 219 220 /* 221 * mbuf statistics 222 */ 223 if (m->m_flags & M_EXT) { 224 if (m->m_next) 225 ip6stat.ip6s_mext2m++; 226 else 227 ip6stat.ip6s_mext1++; 228 } else { 229 #define M2MMAX NELEM(ip6stat.ip6s_m2m) 230 if (m->m_next) { 231 if (m->m_flags & M_LOOP) { 232 ip6stat.ip6s_m2m[loif->if_index]++; /* XXX */ 233 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) 234 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; 235 else 236 ip6stat.ip6s_m2m[0]++; 237 } else 238 ip6stat.ip6s_m1++; 239 #undef M2MMAX 240 } 241 242 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 243 ip6stat.ip6s_total++; 244 245 #ifndef PULLDOWN_TEST 246 /* 247 * L2 bridge code and some other code can return mbuf chain 248 * that does not conform to KAME requirement. too bad. 249 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 250 */ 251 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 252 struct mbuf *n; 253 254 n = m_getb(m->m_pkthdr.len, M_NOWAIT, MT_HEADER, M_PKTHDR); 255 if (n == NULL) 256 goto bad; 257 M_MOVE_PKTHDR(n, m); 258 259 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 260 n->m_len = n->m_pkthdr.len; 261 m_freem(m); 262 m = n; 263 } 264 IP6_EXTHDR_CHECK_VOIDRET(m, 0, sizeof(struct ip6_hdr)); 265 #endif 266 267 if (m->m_len < sizeof(struct ip6_hdr)) { 268 struct ifnet *inifp; 269 inifp = m->m_pkthdr.rcvif; 270 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 271 ip6stat.ip6s_toosmall++; 272 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 273 goto bad2; 274 } 275 } 276 277 ip6 = mtod(m, struct ip6_hdr *); 278 279 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 280 ip6stat.ip6s_badvers++; 281 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 282 goto bad; 283 } 284 285 /* 286 * Run through list of hooks for input packets. 287 * 288 * NB: Beware of the destination address changing 289 * (e.g. by NAT rewriting). When this happens, 290 * tell ip6_forward to do the right thing. 291 */ 292 if (pfil_has_hooks(&inet6_pfil_hook)) { 293 odst = ip6->ip6_dst; 294 if (pfil_run_hooks(&inet6_pfil_hook, &m, 295 m->m_pkthdr.rcvif, PFIL_IN)) { 296 goto bad2; 297 } 298 if (m == NULL) /* consumed by filter */ 299 goto bad2; 300 ip6 = mtod(m, struct ip6_hdr *); 301 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 302 } 303 304 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; 305 306 #ifdef ALTQ 307 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 308 /* packet is dropped by traffic conditioner */ 309 return; 310 } 311 #endif 312 313 /* 314 * Check with the firewall... 315 */ 316 if (ip6_fw_enable && ip6_fw_chk_ptr) { 317 u_short port = 0; 318 /* If ipfw says divert, we have to just drop packet */ 319 /* use port as a dummy argument */ 320 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { 321 m_freem(m); 322 m = NULL; 323 } 324 if (!m) 325 goto bad2; 326 } 327 328 /* 329 * Check against address spoofing/corruption. 330 */ 331 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 332 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 333 /* 334 * XXX: "badscope" is not very suitable for a multicast source. 335 */ 336 ip6stat.ip6s_badscope++; 337 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 338 goto bad; 339 } 340 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || 341 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && 342 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 343 ip6stat.ip6s_badscope++; 344 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 345 goto bad; 346 } 347 348 /* 349 * The following check is not documented in specs. A malicious 350 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 351 * and bypass security checks (act as if it was from 127.0.0.1 by using 352 * IPv6 src ::ffff:127.0.0.1). Be cautious. 353 * 354 * This check chokes if we are in an SIIT cloud. As none of BSDs 355 * support IPv4-less kernel compilation, we cannot support SIIT 356 * environment at all. So, it makes more sense for us to reject any 357 * malicious packets for non-SIIT environment, than try to do a 358 * partial support for SIIT environment. 359 */ 360 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 361 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 362 ip6stat.ip6s_badscope++; 363 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 364 goto bad; 365 } 366 #if 0 367 /* 368 * Reject packets with IPv4 compatible addresses (auto tunnel). 369 * 370 * The code forbids auto tunnel relay case in RFC1933 (the check is 371 * stronger than RFC1933). We may want to re-enable it if mech-xx 372 * is revised to forbid relaying case. 373 */ 374 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 375 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 376 ip6stat.ip6s_badscope++; 377 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 378 goto bad; 379 } 380 #endif 381 382 /* drop packets if interface ID portion is already filled */ 383 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { 384 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && 385 ip6->ip6_src.s6_addr16[1]) { 386 ip6stat.ip6s_badscope++; 387 goto bad; 388 } 389 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) || 390 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) && 391 ip6->ip6_dst.s6_addr16[1]) { 392 ip6stat.ip6s_badscope++; 393 goto bad; 394 } 395 } 396 397 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 398 ip6->ip6_src.s6_addr16[1] 399 = htons(m->m_pkthdr.rcvif->if_index); 400 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 401 ip6->ip6_dst.s6_addr16[1] 402 = htons(m->m_pkthdr.rcvif->if_index); 403 404 /* 405 * Multicast check 406 * 407 * WARNING! For general subnet proxying the interface hw will 408 * likely filter out the multicast solicitations, so 409 * the interface must be in promiscuous mode. 410 */ 411 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 412 ours = 1; 413 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 414 deliverifp = m->m_pkthdr.rcvif; 415 goto hbhcheck; 416 } 417 418 /* 419 * Unicast check 420 */ 421 if (ip6_forward_rt.ro_rt != NULL && 422 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) && 423 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 424 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) { 425 ip6stat.ip6s_forward_cachehit++; 426 } else { 427 struct sockaddr_in6 *dst6; 428 429 if (ip6_forward_rt.ro_rt) { 430 /* route is down or destination is different */ 431 ip6stat.ip6s_forward_cachemiss++; 432 RTFREE(ip6_forward_rt.ro_rt); 433 ip6_forward_rt.ro_rt = 0; 434 } 435 436 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); 437 dst6 = &ip6_forward_rt.ro_dst; 438 dst6->sin6_len = sizeof(struct sockaddr_in6); 439 dst6->sin6_family = AF_INET6; 440 dst6->sin6_addr = ip6->ip6_dst; 441 442 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 443 } 444 445 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) 446 447 /* 448 * Accept the packet if the forwarding interface to the destination 449 * according to the routing table is the loopback interface, 450 * unless the associated route has a gateway. 451 * Note that this approach causes to accept a packet if there is a 452 * route to the loopback interface for the destination of the packet. 453 * But we think it's even useful in some situations, e.g. when using 454 * a special daemon which wants to intercept the packet. 455 * 456 * XXX: some OSes automatically make a cloned route for the destination 457 * of an outgoing packet. If the outgoing interface of the packet 458 * is a loopback one, the kernel would consider the packet to be 459 * accepted, even if we have no such address assinged on the interface. 460 * We check the cloned flag of the route entry to reject such cases, 461 * assuming that route entries for our own addresses are not made by 462 * cloning (it should be true because in6_addloop explicitly installs 463 * the host route). However, we might have to do an explicit check 464 * while it would be less efficient. Or, should we rather install a 465 * reject route for such a case? 466 */ 467 if (ip6_forward_rt.ro_rt && 468 (ip6_forward_rt.ro_rt->rt_flags & 469 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && 470 #ifdef RTF_WASCLONED 471 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && 472 #endif 473 #ifdef RTF_CLONED 474 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && 475 #endif 476 #if 0 477 /* 478 * The check below is redundant since the comparison of 479 * the destination and the key of the rtentry has 480 * already done through looking up the routing table. 481 */ 482 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, 483 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) 484 #endif 485 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { 486 struct in6_ifaddr *ia6 = 487 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; 488 489 /* 490 * record address information into m_aux. 491 */ 492 ip6_setdstifaddr(m, ia6); 493 494 /* 495 * packets to a tentative, duplicated, or somehow invalid 496 * address must not be accepted. 497 */ 498 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { 499 /* this address is ready */ 500 ours = 1; 501 deliverifp = ia6->ia_ifp; /* correct? */ 502 /* Count the packet in the ip address stats */ 503 IFA_STAT_INC(&ia6->ia_ifa, ipackets, 1); 504 IFA_STAT_INC(&ia6->ia_ifa, ibytes, m->m_pkthdr.len); 505 goto hbhcheck; 506 } else { 507 /* address is not ready, so discard the packet. */ 508 nd6log((LOG_INFO, 509 "ip6_input: packet to an unready address %s->%s\n", 510 ip6_sprintf(&ip6->ip6_src), 511 ip6_sprintf(&ip6->ip6_dst))); 512 513 goto bad; 514 } 515 } 516 517 /* 518 * Now there is no reason to process the packet if it's not our own 519 * and we're not a router. 520 */ 521 if (!ip6_forwarding) { 522 ip6stat.ip6s_cantforward++; 523 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 524 goto bad; 525 } 526 527 hbhcheck: 528 /* 529 * record address information into m_aux, if we don't have one yet. 530 * note that we are unable to record it, if the address is not listed 531 * as our interface address (e.g. multicast addresses and such). 532 */ 533 if (deliverifp && !ip6_getdstifaddr(m)) { 534 struct in6_ifaddr *ia6; 535 536 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); 537 if (ia6) { 538 if (!ip6_setdstifaddr(m, ia6)) { 539 /* 540 * XXX maybe we should drop the packet here, 541 * as we could not provide enough information 542 * to the upper layers. 543 */ 544 } 545 } 546 } 547 548 /* 549 * Process Hop-by-Hop options header if it's contained. 550 * m may be modified in ip6_hopopts_input(). 551 * If a JumboPayload option is included, plen will also be modified. 552 */ 553 plen = (u_int32_t)ntohs(ip6->ip6_plen); 554 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 555 struct ip6_hbh *hbh; 556 557 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { 558 #if 0 /*touches NULL pointer*/ 559 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 560 #endif 561 goto bad2; /* m have already been freed */ 562 } 563 564 /* adjust pointer */ 565 ip6 = mtod(m, struct ip6_hdr *); 566 567 /* 568 * if the payload length field is 0 and the next header field 569 * indicates Hop-by-Hop Options header, then a Jumbo Payload 570 * option MUST be included. 571 */ 572 if (ip6->ip6_plen == 0 && plen == 0) { 573 /* 574 * Note that if a valid jumbo payload option is 575 * contained, ip6_hoptops_input() must set a valid 576 * (non-zero) payload length to the variable plen. 577 */ 578 ip6stat.ip6s_badoptions++; 579 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 580 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 581 icmp6_error(m, ICMP6_PARAM_PROB, 582 ICMP6_PARAMPROB_HEADER, 583 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 584 goto bad2; 585 } 586 #ifndef PULLDOWN_TEST 587 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 588 hbh = (struct ip6_hbh *)(ip6 + 1); 589 #else 590 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 591 sizeof(struct ip6_hbh)); 592 if (hbh == NULL) { 593 ip6stat.ip6s_tooshort++; 594 goto bad2; 595 } 596 #endif 597 nxt = hbh->ip6h_nxt; 598 599 /* 600 * If we are acting as a router and the packet contains a 601 * router alert option, see if we know the option value. 602 * Currently, we only support the option value for MLD, in which 603 * case we should pass the packet to the multicast routing 604 * daemon. 605 */ 606 if (rtalert != ~0 && ip6_forwarding) { 607 switch (rtalert) { 608 case IP6OPT_RTALERT_MLD: 609 ours = 1; 610 break; 611 default: 612 /* 613 * RFC2711 requires unrecognized values must be 614 * silently ignored. 615 */ 616 break; 617 } 618 } 619 } else 620 nxt = ip6->ip6_nxt; 621 622 /* 623 * Check that the amount of data in the buffers 624 * is as at least much as the IPv6 header would have us expect. 625 * Trim mbufs if longer than we expect. 626 * Drop packet if shorter than we expect. 627 */ 628 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 629 ip6stat.ip6s_tooshort++; 630 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 631 goto bad; 632 } 633 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 634 if (m->m_len == m->m_pkthdr.len) { 635 m->m_len = sizeof(struct ip6_hdr) + plen; 636 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 637 } else 638 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 639 } 640 641 /* 642 * Forward if desirable. 643 */ 644 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 645 /* 646 * If we are acting as a multicast router, all 647 * incoming multicast packets are passed to the 648 * kernel-level multicast forwarding function. 649 * The packet is returned (relatively) intact; if 650 * ip6_mforward() returns a non-zero value, the packet 651 * must be discarded, else it may be accepted below. 652 */ 653 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 654 ip6stat.ip6s_cantforward++; 655 goto bad; 656 } 657 if (!ours) 658 goto bad; 659 } else if (!ours) { 660 ip6_forward(m, srcrt); 661 goto bad2; 662 } 663 664 ip6 = mtod(m, struct ip6_hdr *); 665 666 /* 667 * Malicious party may be able to use IPv4 mapped addr to confuse 668 * tcp/udp stack and bypass security checks (act as if it was from 669 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 670 * 671 * For SIIT end node behavior, you may want to disable the check. 672 * However, you will become vulnerable to attacks using IPv4 mapped 673 * source. 674 */ 675 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 676 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 677 ip6stat.ip6s_badscope++; 678 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 679 goto bad; 680 } 681 682 /* 683 * Tell launch routine the next header 684 */ 685 ip6stat.ip6s_delivered++; 686 in6_ifstat_inc(deliverifp, ifs6_in_deliver); 687 nest = 0; 688 689 rh_present = 0; 690 while (nxt != IPPROTO_DONE) { 691 struct protosw *sw6; 692 693 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { 694 ip6stat.ip6s_toomanyhdr++; 695 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 696 goto bad; 697 } 698 699 /* 700 * protection against faulty packet - there should be 701 * more sanity checks in header chain processing. 702 */ 703 if (m->m_pkthdr.len < off) { 704 ip6stat.ip6s_tooshort++; 705 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 706 goto bad; 707 } 708 709 #if 0 710 /* 711 * do we need to do it for every header? yeah, other 712 * functions can play with it (like re-allocate and copy). 713 */ 714 mhist = ip6_addaux(m); 715 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { 716 hist = mtod(mhist, caddr_t) + mhist->m_len; 717 bcopy(&nxt, hist, sizeof(nxt)); 718 mhist->m_len += sizeof(nxt); 719 } else { 720 ip6stat.ip6s_toomanyhdr++; 721 goto bad; 722 } 723 #endif 724 725 if (nxt == IPPROTO_ROUTING) { 726 if (rh_present++) { 727 in6_ifstat_inc(m->m_pkthdr.rcvif, 728 ifs6_in_hdrerr); 729 ip6stat.ip6s_badoptions++; 730 goto bad; 731 } 732 } 733 734 sw6 = &inet6sw[ip6_protox[nxt]]; 735 /* 736 * If this is a terminal header forward to the port, otherwise 737 * process synchronously for more headers. 738 */ 739 if (sw6->pr_flags & PR_LASTHDR) { 740 struct netmsg_packet *pmsg; 741 lwkt_port_t port; 742 743 port = netisr_cpuport(0); /* XXX */ 744 if ((m->m_flags & M_HASH) == 0) 745 m_sethash(m, 0); /* XXX */ 746 747 KKASSERT(port != NULL); 748 pmsg = &m->m_hdr.mh_netmsg; 749 netmsg_init(&pmsg->base, NULL, 750 &netisr_apanic_rport, 751 0, transport6_processing_handler); 752 pmsg->nm_packet = m; 753 pmsg->nm_nxt = nxt; 754 pmsg->base.lmsg.u.ms_result = off; 755 lwkt_sendmsg(port, &pmsg->base.lmsg); 756 /* done with m */ 757 nxt = IPPROTO_DONE; 758 } else { 759 nxt = sw6->pr_input(&m, &off, nxt); 760 } 761 } 762 goto bad2; 763 bad: 764 m_freem(m); 765 bad2: 766 ; 767 /* msg was embedded in the mbuf, do not reply! */ 768 } 769 770 /* 771 * We have to call the pr_input() function from the correct protocol 772 * thread. The sw6->pr_soport() request at the end of ip6_input() 773 * returns the port and we forward a netmsg to the port to execute 774 * this function. 775 */ 776 static void 777 transport6_processing_handler(netmsg_t netmsg) 778 { 779 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg; 780 struct protosw *sw6; 781 int hlen; 782 int nxt; 783 784 sw6 = &inet6sw[ip6_protox[pmsg->nm_nxt]]; 785 hlen = pmsg->base.lmsg.u.ms_result; 786 787 nxt = sw6->pr_input(&pmsg->nm_packet, &hlen, pmsg->nm_nxt); 788 KKASSERT(nxt == IPPROTO_DONE); 789 /* netmsg was embedded in the mbuf, do not reply! */ 790 } 791 792 /* 793 * set/grab in6_ifaddr correspond to IPv6 destination address. 794 * XXX backward compatibility wrapper 795 */ 796 static struct ip6aux * 797 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) 798 { 799 struct ip6aux *n; 800 801 n = ip6_addaux(m); 802 if (n) 803 n->ip6a_dstia6 = ia6; 804 return n; /* NULL if failed to set */ 805 } 806 807 struct in6_ifaddr * 808 ip6_getdstifaddr(struct mbuf *m) 809 { 810 struct ip6aux *n; 811 812 n = ip6_findaux(m); 813 if (n) 814 return n->ip6a_dstia6; 815 else 816 return NULL; 817 } 818 819 /* 820 * Hop-by-Hop options header processing. If a valid jumbo payload option is 821 * included, the real payload length will be stored in plenp. 822 */ 823 static int 824 ip6_hopopts_input(u_int32_t *plenp, 825 u_int32_t *rtalertp,/* XXX: should be stored more smart way */ 826 struct mbuf **mp, 827 int *offp) 828 { 829 struct mbuf *m = *mp; 830 int off = *offp, hbhlen; 831 struct ip6_hbh *hbh; 832 833 /* validation of the length of the header */ 834 #ifndef PULLDOWN_TEST 835 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 836 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 837 hbhlen = (hbh->ip6h_len + 1) << 3; 838 839 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 840 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 841 #else 842 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 843 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 844 if (hbh == NULL) { 845 ip6stat.ip6s_tooshort++; 846 return -1; 847 } 848 hbhlen = (hbh->ip6h_len + 1) << 3; 849 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 850 hbhlen); 851 if (hbh == NULL) { 852 ip6stat.ip6s_tooshort++; 853 return -1; 854 } 855 #endif 856 off += hbhlen; 857 hbhlen -= sizeof(struct ip6_hbh); 858 859 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 860 hbhlen, rtalertp, plenp) < 0) 861 return (-1); 862 863 *offp = off; 864 *mp = m; 865 return (0); 866 } 867 868 /* 869 * Search header for all Hop-by-hop options and process each option. 870 * This function is separate from ip6_hopopts_input() in order to 871 * handle a case where the sending node itself process its hop-by-hop 872 * options header. In such a case, the function is called from ip6_output(). 873 * 874 * The function assumes that hbh header is located right after the IPv6 header 875 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 876 * opthead + hbhlen is located in continuous memory region. 877 */ 878 int 879 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 880 u_int32_t *rtalertp, u_int32_t *plenp) 881 { 882 struct ip6_hdr *ip6; 883 int optlen = 0; 884 u_int8_t *opt = opthead; 885 u_int16_t rtalert_val; 886 u_int32_t jumboplen; 887 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 888 889 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 890 switch (*opt) { 891 case IP6OPT_PAD1: 892 optlen = 1; 893 break; 894 case IP6OPT_PADN: 895 if (hbhlen < IP6OPT_MINLEN) { 896 ip6stat.ip6s_toosmall++; 897 goto bad; 898 } 899 optlen = *(opt + 1) + 2; 900 break; 901 case IP6OPT_RTALERT: 902 /* XXX may need check for alignment */ 903 if (hbhlen < IP6OPT_RTALERT_LEN) { 904 ip6stat.ip6s_toosmall++; 905 goto bad; 906 } 907 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 908 /* XXX stat */ 909 icmp6_error(m, ICMP6_PARAM_PROB, 910 ICMP6_PARAMPROB_HEADER, 911 erroff + opt + 1 - opthead); 912 return (-1); 913 } 914 optlen = IP6OPT_RTALERT_LEN; 915 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 916 *rtalertp = ntohs(rtalert_val); 917 break; 918 case IP6OPT_JUMBO: 919 /* XXX may need check for alignment */ 920 if (hbhlen < IP6OPT_JUMBO_LEN) { 921 ip6stat.ip6s_toosmall++; 922 goto bad; 923 } 924 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 925 /* XXX stat */ 926 icmp6_error(m, ICMP6_PARAM_PROB, 927 ICMP6_PARAMPROB_HEADER, 928 erroff + opt + 1 - opthead); 929 return (-1); 930 } 931 optlen = IP6OPT_JUMBO_LEN; 932 933 /* 934 * IPv6 packets that have non 0 payload length 935 * must not contain a jumbo payload option. 936 */ 937 ip6 = mtod(m, struct ip6_hdr *); 938 if (ip6->ip6_plen) { 939 ip6stat.ip6s_badoptions++; 940 icmp6_error(m, ICMP6_PARAM_PROB, 941 ICMP6_PARAMPROB_HEADER, 942 erroff + opt - opthead); 943 return (-1); 944 } 945 946 /* 947 * We may see jumbolen in unaligned location, so 948 * we'd need to perform bcopy(). 949 */ 950 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 951 jumboplen = (u_int32_t)htonl(jumboplen); 952 953 #if 1 954 /* 955 * if there are multiple jumbo payload options, 956 * *plenp will be non-zero and the packet will be 957 * rejected. 958 * the behavior may need some debate in ipngwg - 959 * multiple options does not make sense, however, 960 * there's no explicit mention in specification. 961 */ 962 if (*plenp != 0) { 963 ip6stat.ip6s_badoptions++; 964 icmp6_error(m, ICMP6_PARAM_PROB, 965 ICMP6_PARAMPROB_HEADER, 966 erroff + opt + 2 - opthead); 967 return (-1); 968 } 969 #endif 970 971 /* 972 * jumbo payload length must be larger than 65535. 973 */ 974 if (jumboplen <= IPV6_MAXPACKET) { 975 ip6stat.ip6s_badoptions++; 976 icmp6_error(m, ICMP6_PARAM_PROB, 977 ICMP6_PARAMPROB_HEADER, 978 erroff + opt + 2 - opthead); 979 return (-1); 980 } 981 *plenp = jumboplen; 982 983 break; 984 default: /* unknown option */ 985 if (hbhlen < IP6OPT_MINLEN) { 986 ip6stat.ip6s_toosmall++; 987 goto bad; 988 } 989 optlen = ip6_unknown_opt(opt, m, 990 erroff + opt - opthead); 991 if (optlen == -1) 992 return (-1); 993 optlen += 2; 994 break; 995 } 996 } 997 998 return (0); 999 1000 bad: 1001 m_freem(m); 1002 return (-1); 1003 } 1004 1005 /* 1006 * Unknown option processing. 1007 * The third argument `off' is the offset from the IPv6 header to the option, 1008 * which is necessary if the IPv6 header the and option header and IPv6 header 1009 * is not continuous in order to return an ICMPv6 error. 1010 */ 1011 int 1012 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1013 { 1014 struct ip6_hdr *ip6; 1015 1016 switch (IP6OPT_TYPE(*optp)) { 1017 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1018 return ((int)*(optp + 1)); 1019 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1020 m_freem(m); 1021 return (-1); 1022 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1023 ip6stat.ip6s_badoptions++; 1024 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1025 return (-1); 1026 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1027 ip6stat.ip6s_badoptions++; 1028 ip6 = mtod(m, struct ip6_hdr *); 1029 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1030 (m->m_flags & (M_BCAST|M_MCAST))) 1031 m_freem(m); 1032 else 1033 icmp6_error(m, ICMP6_PARAM_PROB, 1034 ICMP6_PARAMPROB_OPTION, off); 1035 return (-1); 1036 } 1037 1038 m_freem(m); /* XXX: NOTREACHED */ 1039 return (-1); 1040 } 1041 1042 /* 1043 * Create the "control" list for this pcb. 1044 * The function will not modify mbuf chain at all. 1045 * 1046 * with KAME mbuf chain restriction: 1047 * The routine will be called from upper layer handlers like tcp6_input(). 1048 * Thus the routine assumes that the caller (tcp6_input) have already 1049 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1050 * very first mbuf on the mbuf chain. 1051 */ 1052 void 1053 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6, 1054 struct mbuf *m) 1055 { 1056 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y)) 1057 struct thread *td = curthread; /* XXX */ 1058 int privileged = 0; 1059 1060 1061 if (priv_check(td, PRIV_ROOT) == 0) 1062 privileged++; 1063 1064 #ifdef SO_TIMESTAMP 1065 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { 1066 struct timeval tv; 1067 1068 microtime(&tv); 1069 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv), 1070 SCM_TIMESTAMP, SOL_SOCKET); 1071 if (*mp) { 1072 mp = &(*mp)->m_next; 1073 } 1074 } 1075 #endif 1076 1077 /* RFC 2292 sec. 5 */ 1078 if (in6p->in6p_flags & IN6P_PKTINFO) { 1079 struct in6_pktinfo pi6; 1080 1081 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1082 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1083 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) ? 1084 m->m_pkthdr.rcvif->if_index : 0; 1085 *mp = sbcreatecontrol((caddr_t)&pi6, sizeof(struct in6_pktinfo), 1086 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1087 if (*mp) 1088 mp = &(*mp)->m_next; 1089 } 1090 1091 if (in6p->in6p_flags & IN6P_HOPLIMIT) { 1092 int hlim = ip6->ip6_hlim & 0xff; 1093 1094 *mp = sbcreatecontrol((caddr_t)&hlim, sizeof(int), 1095 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); 1096 if (*mp) 1097 mp = &(*mp)->m_next; 1098 } 1099 1100 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) { 1101 u_int32_t flowinfo; 1102 int tclass; 1103 1104 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1105 flowinfo >>= 20; 1106 1107 tclass = flowinfo & 0xff; 1108 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass), 1109 IPV6_TCLASS, IPPROTO_IPV6); 1110 if (*mp) 1111 mp = &(*mp)->m_next; 1112 } 1113 1114 /* 1115 * IPV6_HOPOPTS socket option. We require super-user privilege 1116 * for the option, but it might be too strict, since there might 1117 * be some hop-by-hop options which can be returned to normal user. 1118 * See RFC 2292 section 6. 1119 */ 1120 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { 1121 /* 1122 * Check if a hop-by-hop options header is contatined in the 1123 * received packet, and if so, store the options as ancillary 1124 * data. Note that a hop-by-hop options header must be 1125 * just after the IPv6 header, which is assured through the 1126 * IPv6 input processing. 1127 */ 1128 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1129 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1130 struct ip6_hbh *hbh; 1131 int hbhlen = 0; 1132 #ifdef PULLDOWN_TEST 1133 struct mbuf *ext; 1134 #endif 1135 1136 #ifndef PULLDOWN_TEST 1137 hbh = (struct ip6_hbh *)(ip6 + 1); 1138 hbhlen = (hbh->ip6h_len + 1) << 3; 1139 #else 1140 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1141 ip6->ip6_nxt); 1142 if (ext == NULL) { 1143 ip6stat.ip6s_tooshort++; 1144 return; 1145 } 1146 hbh = mtod(ext, struct ip6_hbh *); 1147 hbhlen = (hbh->ip6h_len + 1) << 3; 1148 if (hbhlen != ext->m_len) { 1149 m_freem(ext); 1150 ip6stat.ip6s_tooshort++; 1151 return; 1152 } 1153 #endif 1154 1155 /* 1156 * XXX: We copy the whole header even if a 1157 * jumbo payload option is included, the option which 1158 * is to be removed before returning according to 1159 * RFC 2292. 1160 * Note: this constraint is removed in 2292bis. 1161 */ 1162 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1163 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1164 IPPROTO_IPV6); 1165 if (*mp) 1166 mp = &(*mp)->m_next; 1167 #ifdef PULLDOWN_TEST 1168 m_freem(ext); 1169 #endif 1170 } 1171 } 1172 1173 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ 1174 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1175 int proto, off, nxt; 1176 1177 /* 1178 * go through the header chain to see if a routing header is 1179 * contained in the packet. We need this information to store 1180 * destination options headers (if any) properly. 1181 * XXX: performance issue. We should record this info when 1182 * processing extension headers in incoming routine. 1183 * (todo) use m_aux? 1184 */ 1185 proto = IPPROTO_IPV6; 1186 off = 0; 1187 nxt = -1; 1188 while (1) { 1189 int newoff; 1190 1191 newoff = ip6_nexthdr(m, off, proto, &nxt); 1192 if (newoff < 0) 1193 break; 1194 if (newoff < off) /* invalid, check for safety */ 1195 break; 1196 if ((proto = nxt) == IPPROTO_ROUTING) 1197 break; 1198 off = newoff; 1199 } 1200 } 1201 1202 if ((in6p->in6p_flags & 1203 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { 1204 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1205 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1206 1207 /* 1208 * Search for destination options headers or routing 1209 * header(s) through the header chain, and stores each 1210 * header as ancillary data. 1211 * Note that the order of the headers remains in 1212 * the chain of ancillary data. 1213 */ 1214 while (1) { /* is explicit loop prevention necessary? */ 1215 struct ip6_ext *ip6e = NULL; 1216 int elen; 1217 #ifdef PULLDOWN_TEST 1218 struct mbuf *ext = NULL; 1219 #endif 1220 1221 /* 1222 * if it is not an extension header, don't try to 1223 * pull it from the chain. 1224 */ 1225 switch (nxt) { 1226 case IPPROTO_DSTOPTS: 1227 case IPPROTO_ROUTING: 1228 case IPPROTO_HOPOPTS: 1229 case IPPROTO_AH: /* is it possible? */ 1230 break; 1231 default: 1232 goto loopend; 1233 } 1234 1235 #ifndef PULLDOWN_TEST 1236 if (off + sizeof(*ip6e) > m->m_len) 1237 goto loopend; 1238 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1239 if (nxt == IPPROTO_AH) 1240 elen = (ip6e->ip6e_len + 2) << 2; 1241 else 1242 elen = (ip6e->ip6e_len + 1) << 3; 1243 if (off + elen > m->m_len) 1244 goto loopend; 1245 #else 1246 ext = ip6_pullexthdr(m, off, nxt); 1247 if (ext == NULL) { 1248 ip6stat.ip6s_tooshort++; 1249 return; 1250 } 1251 ip6e = mtod(ext, struct ip6_ext *); 1252 if (nxt == IPPROTO_AH) 1253 elen = (ip6e->ip6e_len + 2) << 2; 1254 else 1255 elen = (ip6e->ip6e_len + 1) << 3; 1256 if (elen != ext->m_len) { 1257 m_freem(ext); 1258 ip6stat.ip6s_tooshort++; 1259 return; 1260 } 1261 #endif 1262 1263 switch (nxt) { 1264 case IPPROTO_DSTOPTS: 1265 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) 1266 break; 1267 1268 /* 1269 * We also require super-user privilege for 1270 * the option. See comments on IN6_HOPOPTS. 1271 */ 1272 if (!privileged) 1273 break; 1274 1275 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1276 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1277 IPPROTO_IPV6); 1278 if (*mp) 1279 mp = &(*mp)->m_next; 1280 break; 1281 case IPPROTO_ROUTING: 1282 if (!(in6p->in6p_flags & IN6P_RTHDR)) 1283 break; 1284 1285 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1286 IS2292(IPV6_2292RTHDR, IPV6_RTHDR), 1287 IPPROTO_IPV6); 1288 if (*mp) 1289 mp = &(*mp)->m_next; 1290 break; 1291 case IPPROTO_HOPOPTS: 1292 case IPPROTO_AH: /* is it possible? */ 1293 break; 1294 1295 default: 1296 /* 1297 * other cases have been filtered in the above. 1298 * none will visit this case. here we supply 1299 * the code just in case (nxt overwritten or 1300 * other cases). 1301 */ 1302 #ifdef PULLDOWN_TEST 1303 m_freem(ext); 1304 #endif 1305 goto loopend; 1306 1307 } 1308 1309 /* proceed with the next header. */ 1310 off += elen; 1311 nxt = ip6e->ip6e_nxt; 1312 ip6e = NULL; 1313 #ifdef PULLDOWN_TEST 1314 m_freem(ext); 1315 ext = NULL; 1316 #endif 1317 } 1318 loopend: 1319 ; 1320 } 1321 #undef IS2292 1322 } 1323 1324 void 1325 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) 1326 { 1327 struct socket *so; 1328 struct mbuf *m_mtu; 1329 struct ip6_mtuinfo mtuctl; 1330 1331 so = in6p->inp_socket; 1332 1333 if (mtu == NULL) 1334 return; 1335 1336 #ifdef DIAGNOSTIC 1337 if (so == NULL) /* I believe this is impossible */ 1338 panic("ip6_notify_pmtu: socket is NULL"); 1339 #endif 1340 1341 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ 1342 mtuctl.ip6m_mtu = *mtu; 1343 mtuctl.ip6m_addr = *dst; 1344 1345 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1346 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1347 return; 1348 1349 lwkt_gettoken(&so->so_rcv.ssb_token); 1350 if (sbappendaddr(&so->so_rcv.sb, (struct sockaddr *)dst, NULL, m_mtu) 1351 == 0) { 1352 m_freem(m_mtu); 1353 /* XXX: should count statistics */ 1354 } else { 1355 sorwakeup(so); 1356 } 1357 lwkt_reltoken(&so->so_rcv.ssb_token); 1358 } 1359 1360 #ifdef PULLDOWN_TEST 1361 /* 1362 * pull single extension header from mbuf chain. returns single mbuf that 1363 * contains the result, or NULL on error. 1364 */ 1365 static struct mbuf * 1366 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1367 { 1368 struct ip6_ext ip6e; 1369 size_t elen; 1370 struct mbuf *n; 1371 1372 #ifdef DIAGNOSTIC 1373 switch (nxt) { 1374 case IPPROTO_DSTOPTS: 1375 case IPPROTO_ROUTING: 1376 case IPPROTO_HOPOPTS: 1377 case IPPROTO_AH: /* is it possible? */ 1378 break; 1379 default: 1380 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1381 } 1382 #endif 1383 1384 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1385 if (nxt == IPPROTO_AH) 1386 elen = (ip6e.ip6e_len + 2) << 2; 1387 else 1388 elen = (ip6e.ip6e_len + 1) << 3; 1389 1390 n = m_getb(elen, M_NOWAIT, MT_DATA, 0); 1391 if (n == NULL) 1392 return NULL; 1393 n->m_len = 0; 1394 1395 if (elen >= M_TRAILINGSPACE(n)) { 1396 m_free(n); 1397 return NULL; 1398 } 1399 1400 m_copydata(m, off, elen, mtod(n, caddr_t)); 1401 n->m_len = elen; 1402 return n; 1403 } 1404 #endif 1405 1406 /* 1407 * Get pointer to the previous header followed by the header 1408 * currently processed. 1409 * XXX: This function supposes that 1410 * M includes all headers, 1411 * the next header field and the header length field of each header 1412 * are valid, and 1413 * the sum of each header length equals to OFF. 1414 * Because of these assumptions, this function must be called very 1415 * carefully. Moreover, it will not be used in the near future when 1416 * we develop `neater' mechanism to process extension headers. 1417 */ 1418 char * 1419 ip6_get_prevhdr(struct mbuf *m, int off) 1420 { 1421 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1422 1423 if (off == sizeof(struct ip6_hdr)) 1424 return (&ip6->ip6_nxt); 1425 else { 1426 int len, nxt; 1427 struct ip6_ext *ip6e = NULL; 1428 1429 nxt = ip6->ip6_nxt; 1430 len = sizeof(struct ip6_hdr); 1431 while (len < off) { 1432 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1433 1434 switch (nxt) { 1435 case IPPROTO_FRAGMENT: 1436 len += sizeof(struct ip6_frag); 1437 break; 1438 case IPPROTO_AH: 1439 len += (ip6e->ip6e_len + 2) << 2; 1440 break; 1441 default: 1442 len += (ip6e->ip6e_len + 1) << 3; 1443 break; 1444 } 1445 nxt = ip6e->ip6e_nxt; 1446 } 1447 if (ip6e) 1448 return (&ip6e->ip6e_nxt); 1449 else 1450 return NULL; 1451 } 1452 } 1453 1454 /* 1455 * get next header offset. m will be retained. 1456 */ 1457 int 1458 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) 1459 { 1460 struct ip6_hdr ip6; 1461 struct ip6_ext ip6e; 1462 struct ip6_frag fh; 1463 1464 /* just in case */ 1465 if (m == NULL) 1466 panic("ip6_nexthdr: m == NULL"); 1467 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1468 return -1; 1469 1470 switch (proto) { 1471 case IPPROTO_IPV6: 1472 if (m->m_pkthdr.len < off + sizeof(ip6)) 1473 return -1; 1474 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1475 if (nxtp) 1476 *nxtp = ip6.ip6_nxt; 1477 off += sizeof(ip6); 1478 return off; 1479 1480 case IPPROTO_FRAGMENT: 1481 /* 1482 * terminate parsing if it is not the first fragment, 1483 * it does not make sense to parse through it. 1484 */ 1485 if (m->m_pkthdr.len < off + sizeof(fh)) 1486 return -1; 1487 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1488 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1489 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1490 return -1; 1491 if (nxtp) 1492 *nxtp = fh.ip6f_nxt; 1493 off += sizeof(struct ip6_frag); 1494 return off; 1495 1496 case IPPROTO_AH: 1497 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1498 return -1; 1499 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1500 if (nxtp) 1501 *nxtp = ip6e.ip6e_nxt; 1502 off += (ip6e.ip6e_len + 2) << 2; 1503 return off; 1504 1505 case IPPROTO_HOPOPTS: 1506 case IPPROTO_ROUTING: 1507 case IPPROTO_DSTOPTS: 1508 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1509 return -1; 1510 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1511 if (nxtp) 1512 *nxtp = ip6e.ip6e_nxt; 1513 off += (ip6e.ip6e_len + 1) << 3; 1514 return off; 1515 1516 case IPPROTO_NONE: 1517 case IPPROTO_ESP: 1518 case IPPROTO_IPCOMP: 1519 /* give up */ 1520 return -1; 1521 1522 default: 1523 return -1; 1524 } 1525 1526 return -1; 1527 } 1528 1529 /* 1530 * get offset for the last header in the chain. m will be kept untainted. 1531 */ 1532 int 1533 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) 1534 { 1535 int newoff; 1536 int nxt; 1537 1538 if (!nxtp) { 1539 nxt = -1; 1540 nxtp = &nxt; 1541 } 1542 while (1) { 1543 newoff = ip6_nexthdr(m, off, proto, nxtp); 1544 if (newoff < 0) 1545 return off; 1546 else if (newoff < off) 1547 return -1; /* invalid */ 1548 else if (newoff == off) 1549 return newoff; 1550 1551 off = newoff; 1552 proto = *nxtp; 1553 } 1554 } 1555 1556 struct ip6aux * 1557 ip6_addaux(struct mbuf *m) 1558 { 1559 struct m_tag *mtag; 1560 1561 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1562 if (!mtag) { 1563 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), 1564 M_NOWAIT); 1565 if (mtag) 1566 m_tag_prepend(m, mtag); 1567 } 1568 if (mtag) 1569 bzero(m_tag_data(mtag), sizeof(struct ip6aux)); 1570 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1571 } 1572 1573 struct ip6aux * 1574 ip6_findaux(struct mbuf *m) 1575 { 1576 struct m_tag *mtag; 1577 1578 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1579 return mtag ? (struct ip6aux *)m_tag_data(mtag) : NULL; 1580 } 1581 1582 void 1583 ip6_delaux(struct mbuf *m) 1584 { 1585 struct m_tag *mtag; 1586 1587 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); 1588 if (mtag) 1589 m_tag_delete(m, mtag); 1590 } 1591 1592 /* 1593 * System control for IP6 1594 */ 1595 1596 u_char inet6ctlerrmap[PRC_NCMDS] = { 1597 0, 0, 0, 0, 1598 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1599 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1600 EMSGSIZE, EHOSTUNREACH, 0, 0, 1601 0, 0, 0, 0, 1602 ENOPROTOOPT 1603 }; 1604