1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1988, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 #include "opt_route.h" 70 #include "opt_rss.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/hhook.h> 75 #include <sys/malloc.h> 76 #include <sys/mbuf.h> 77 #include <sys/proc.h> 78 #include <sys/domain.h> 79 #include <sys/protosw.h> 80 #include <sys/sdt.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/errno.h> 84 #include <sys/time.h> 85 #include <sys/kernel.h> 86 #include <sys/lock.h> 87 #include <sys/rmlock.h> 88 #include <sys/syslog.h> 89 90 #include <net/if.h> 91 #include <net/if_var.h> 92 #include <net/if_types.h> 93 #include <net/if_dl.h> 94 #include <net/route.h> 95 #include <net/netisr.h> 96 #include <net/rss_config.h> 97 #include <net/pfil.h> 98 #include <net/vnet.h> 99 100 #include <netinet/in.h> 101 #include <netinet/in_kdtrace.h> 102 #include <netinet/ip_var.h> 103 #include <netinet/in_systm.h> 104 #include <net/if_llatbl.h> 105 #ifdef INET 106 #include <netinet/ip.h> 107 #include <netinet/ip_icmp.h> 108 #endif /* INET */ 109 #include <netinet/ip6.h> 110 #include <netinet6/in6_var.h> 111 #include <netinet6/ip6_var.h> 112 #include <netinet/in_pcb.h> 113 #include <netinet/icmp6.h> 114 #include <netinet6/scope6_var.h> 115 #include <netinet6/in6_ifattach.h> 116 #include <netinet6/nd6.h> 117 #include <netinet6/in6_rss.h> 118 119 #ifdef IPSEC 120 #include <netipsec/ipsec.h> 121 #include <netinet6/ip6_ipsec.h> 122 #include <netipsec/ipsec6.h> 123 #endif /* IPSEC */ 124 125 #include <netinet6/ip6protosw.h> 126 127 extern struct domain inet6domain; 128 129 u_char ip6_protox[IPPROTO_MAX]; 130 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); 131 VNET_DEFINE(struct in6_ifaddrlisthead *, in6_ifaddrhashtbl); 132 VNET_DEFINE(u_long, in6_ifaddrhmask); 133 134 static struct netisr_handler ip6_nh = { 135 .nh_name = "ip6", 136 .nh_handler = ip6_input, 137 .nh_proto = NETISR_IPV6, 138 #ifdef RSS 139 .nh_m2cpuid = rss_soft_m2cpuid_v6, 140 .nh_policy = NETISR_POLICY_CPU, 141 .nh_dispatch = NETISR_DISPATCH_HYBRID, 142 #else 143 .nh_policy = NETISR_POLICY_FLOW, 144 #endif 145 }; 146 147 #ifdef RSS 148 static struct netisr_handler ip6_direct_nh = { 149 .nh_name = "ip6_direct", 150 .nh_handler = ip6_direct_input, 151 .nh_proto = NETISR_IPV6_DIRECT, 152 .nh_m2cpuid = rss_soft_m2cpuid_v6, 153 .nh_policy = NETISR_POLICY_CPU, 154 .nh_dispatch = NETISR_DISPATCH_HYBRID, 155 }; 156 #endif 157 158 VNET_DEFINE(struct pfil_head, inet6_pfil_hook); 159 160 VNET_PCPUSTAT_DEFINE(struct ip6stat, ip6stat); 161 VNET_PCPUSTAT_SYSINIT(ip6stat); 162 #ifdef VIMAGE 163 VNET_PCPUSTAT_SYSUNINIT(ip6stat); 164 #endif /* VIMAGE */ 165 166 struct rmlock in6_ifaddr_lock; 167 RM_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); 168 169 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); 170 #ifdef PULLDOWN_TEST 171 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); 172 #endif 173 174 /* 175 * IP6 initialization: fill in IP6 protocol switch table. 176 * All protocols not implemented in kernel go to raw IP6 protocol handler. 177 */ 178 void 179 ip6_init(void) 180 { 181 struct protosw *pr; 182 int i; 183 184 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", 185 &V_ip6_auto_linklocal); 186 TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv); 187 TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr); 188 189 TAILQ_INIT(&V_in6_ifaddrhead); 190 V_in6_ifaddrhashtbl = hashinit(IN6ADDR_NHASH, M_IFADDR, 191 &V_in6_ifaddrhmask); 192 193 /* Initialize packet filter hooks. */ 194 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF; 195 V_inet6_pfil_hook.ph_af = AF_INET6; 196 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0) 197 printf("%s: WARNING: unable to register pfil hook, " 198 "error %d\n", __func__, i); 199 200 if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET6, 201 &V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 202 HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0) 203 printf("%s: WARNING: unable to register input helper hook\n", 204 __func__); 205 if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET6, 206 &V_ipsec_hhh_out[HHOOK_IPSEC_INET6], 207 HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0) 208 printf("%s: WARNING: unable to register output helper hook\n", 209 __func__); 210 211 scope6_init(); 212 addrsel_policy_init(); 213 nd6_init(); 214 frag6_init(); 215 216 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; 217 218 /* Skip global initialization stuff for non-default instances. */ 219 #ifdef VIMAGE 220 if (!IS_DEFAULT_VNET(curvnet)) { 221 netisr_register_vnet(&ip6_nh); 222 #ifdef RSS 223 netisr_register_vnet(&ip6_direct_nh); 224 #endif 225 return; 226 } 227 #endif 228 229 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 230 if (pr == NULL) 231 panic("ip6_init"); 232 233 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ 234 for (i = 0; i < IPPROTO_MAX; i++) 235 ip6_protox[i] = pr - inet6sw; 236 /* 237 * Cycle through IP protocols and put them into the appropriate place 238 * in ip6_protox[]. 239 */ 240 for (pr = inet6domain.dom_protosw; 241 pr < inet6domain.dom_protoswNPROTOSW; pr++) 242 if (pr->pr_domain->dom_family == PF_INET6 && 243 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) { 244 /* Be careful to only index valid IP protocols. */ 245 if (pr->pr_protocol < IPPROTO_MAX) 246 ip6_protox[pr->pr_protocol] = pr - inet6sw; 247 } 248 249 netisr_register(&ip6_nh); 250 #ifdef RSS 251 netisr_register(&ip6_direct_nh); 252 #endif 253 } 254 255 /* 256 * The protocol to be inserted into ip6_protox[] must be already registered 257 * in inet6sw[], either statically or through pf_proto_register(). 258 */ 259 int 260 ip6proto_register(short ip6proto) 261 { 262 struct protosw *pr; 263 264 /* Sanity checks. */ 265 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX) 266 return (EPROTONOSUPPORT); 267 268 /* 269 * The protocol slot must not be occupied by another protocol 270 * already. An index pointing to IPPROTO_RAW is unused. 271 */ 272 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 273 if (pr == NULL) 274 return (EPFNOSUPPORT); 275 if (ip6_protox[ip6proto] != pr - inet6sw) /* IPPROTO_RAW */ 276 return (EEXIST); 277 278 /* 279 * Find the protocol position in inet6sw[] and set the index. 280 */ 281 for (pr = inet6domain.dom_protosw; 282 pr < inet6domain.dom_protoswNPROTOSW; pr++) { 283 if (pr->pr_domain->dom_family == PF_INET6 && 284 pr->pr_protocol && pr->pr_protocol == ip6proto) { 285 ip6_protox[pr->pr_protocol] = pr - inet6sw; 286 return (0); 287 } 288 } 289 return (EPROTONOSUPPORT); 290 } 291 292 int 293 ip6proto_unregister(short ip6proto) 294 { 295 struct protosw *pr; 296 297 /* Sanity checks. */ 298 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX) 299 return (EPROTONOSUPPORT); 300 301 /* Check if the protocol was indeed registered. */ 302 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); 303 if (pr == NULL) 304 return (EPFNOSUPPORT); 305 if (ip6_protox[ip6proto] == pr - inet6sw) /* IPPROTO_RAW */ 306 return (ENOENT); 307 308 /* Reset the protocol slot to IPPROTO_RAW. */ 309 ip6_protox[ip6proto] = pr - inet6sw; 310 return (0); 311 } 312 313 #ifdef VIMAGE 314 static void 315 ip6_destroy(void *unused __unused) 316 { 317 int error; 318 319 #ifdef RSS 320 netisr_unregister_vnet(&ip6_direct_nh); 321 #endif 322 netisr_unregister_vnet(&ip6_nh); 323 324 if ((error = pfil_head_unregister(&V_inet6_pfil_hook)) != 0) 325 printf("%s: WARNING: unable to unregister pfil hook, " 326 "error %d\n", __func__, error); 327 error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET6]); 328 if (error != 0) { 329 printf("%s: WARNING: unable to deregister input helper hook " 330 "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET6: " 331 "error %d returned\n", __func__, error); 332 } 333 error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET6]); 334 if (error != 0) { 335 printf("%s: WARNING: unable to deregister output helper hook " 336 "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET6: " 337 "error %d returned\n", __func__, error); 338 } 339 hashdestroy(V_in6_ifaddrhashtbl, M_IFADDR, V_in6_ifaddrhmask); 340 nd6_destroy(); 341 in6_ifattach_destroy(); 342 } 343 344 VNET_SYSUNINIT(inet6, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip6_destroy, NULL); 345 #endif 346 347 static int 348 ip6_input_hbh(struct mbuf *m, uint32_t *plen, uint32_t *rtalert, int *off, 349 int *nxt, int *ours) 350 { 351 struct ip6_hdr *ip6; 352 struct ip6_hbh *hbh; 353 354 if (ip6_hopopts_input(plen, rtalert, &m, off)) { 355 #if 0 /*touches NULL pointer*/ 356 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 357 #endif 358 goto out; /* m have already been freed */ 359 } 360 361 /* adjust pointer */ 362 ip6 = mtod(m, struct ip6_hdr *); 363 364 /* 365 * if the payload length field is 0 and the next header field 366 * indicates Hop-by-Hop Options header, then a Jumbo Payload 367 * option MUST be included. 368 */ 369 if (ip6->ip6_plen == 0 && *plen == 0) { 370 /* 371 * Note that if a valid jumbo payload option is 372 * contained, ip6_hopopts_input() must set a valid 373 * (non-zero) payload length to the variable plen. 374 */ 375 IP6STAT_INC(ip6s_badoptions); 376 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 377 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 378 icmp6_error(m, ICMP6_PARAM_PROB, 379 ICMP6_PARAMPROB_HEADER, 380 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); 381 goto out; 382 } 383 #ifndef PULLDOWN_TEST 384 /* ip6_hopopts_input() ensures that mbuf is contiguous */ 385 hbh = (struct ip6_hbh *)(ip6 + 1); 386 #else 387 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 388 sizeof(struct ip6_hbh)); 389 if (hbh == NULL) { 390 IP6STAT_INC(ip6s_tooshort); 391 goto out; 392 } 393 #endif 394 *nxt = hbh->ip6h_nxt; 395 396 /* 397 * If we are acting as a router and the packet contains a 398 * router alert option, see if we know the option value. 399 * Currently, we only support the option value for MLD, in which 400 * case we should pass the packet to the multicast routing 401 * daemon. 402 */ 403 if (*rtalert != ~0) { 404 switch (*rtalert) { 405 case IP6OPT_RTALERT_MLD: 406 if (V_ip6_forwarding) 407 *ours = 1; 408 break; 409 default: 410 /* 411 * RFC2711 requires unrecognized values must be 412 * silently ignored. 413 */ 414 break; 415 } 416 } 417 418 return (0); 419 420 out: 421 return (1); 422 } 423 424 #ifdef RSS 425 /* 426 * IPv6 direct input routine. 427 * 428 * This is called when reinjecting completed fragments where 429 * all of the previous checking and book-keeping has been done. 430 */ 431 void 432 ip6_direct_input(struct mbuf *m) 433 { 434 int off, nxt; 435 int nest; 436 struct m_tag *mtag; 437 struct ip6_direct_ctx *ip6dc; 438 439 mtag = m_tag_locate(m, MTAG_ABI_IPV6, IPV6_TAG_DIRECT, NULL); 440 KASSERT(mtag != NULL, ("Reinjected packet w/o direct ctx tag!")); 441 442 ip6dc = (struct ip6_direct_ctx *)(mtag + 1); 443 nxt = ip6dc->ip6dc_nxt; 444 off = ip6dc->ip6dc_off; 445 446 nest = 0; 447 448 m_tag_delete(m, mtag); 449 450 while (nxt != IPPROTO_DONE) { 451 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 452 IP6STAT_INC(ip6s_toomanyhdr); 453 goto bad; 454 } 455 456 /* 457 * protection against faulty packet - there should be 458 * more sanity checks in header chain processing. 459 */ 460 if (m->m_pkthdr.len < off) { 461 IP6STAT_INC(ip6s_tooshort); 462 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 463 goto bad; 464 } 465 466 #ifdef IPSEC 467 /* 468 * enforce IPsec policy checking if we are seeing last header. 469 * note that we do not visit this with protocols with pcb layer 470 * code - like udp/tcp/raw ip. 471 */ 472 if (ip6_ipsec_input(m, nxt)) 473 goto bad; 474 #endif /* IPSEC */ 475 476 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 477 } 478 return; 479 bad: 480 m_freem(m); 481 } 482 #endif 483 484 void 485 ip6_input(struct mbuf *m) 486 { 487 struct in6_addr odst; 488 struct ip6_hdr *ip6; 489 struct in6_ifaddr *ia; 490 u_int32_t plen; 491 u_int32_t rtalert = ~0; 492 int off = sizeof(struct ip6_hdr), nest; 493 int nxt, ours = 0; 494 int srcrt = 0; 495 496 #ifdef IPSEC 497 /* 498 * should the inner packet be considered authentic? 499 * see comment in ah4_input(). 500 * NB: m cannot be NULL when passed to the input routine 501 */ 502 503 m->m_flags &= ~M_AUTHIPHDR; 504 m->m_flags &= ~M_AUTHIPDGM; 505 506 #endif /* IPSEC */ 507 508 if (m->m_flags & M_FASTFWD_OURS) { 509 /* 510 * Firewall changed destination to local. 511 */ 512 m->m_flags &= ~M_FASTFWD_OURS; 513 ours = 1; 514 ip6 = mtod(m, struct ip6_hdr *); 515 goto hbhcheck; 516 } 517 518 /* 519 * mbuf statistics 520 */ 521 if (m->m_flags & M_EXT) { 522 if (m->m_next) 523 IP6STAT_INC(ip6s_mext2m); 524 else 525 IP6STAT_INC(ip6s_mext1); 526 } else { 527 if (m->m_next) { 528 if (m->m_flags & M_LOOP) { 529 IP6STAT_INC(ip6s_m2m[V_loif->if_index]); 530 } else if (m->m_pkthdr.rcvif->if_index < IP6S_M2MMAX) 531 IP6STAT_INC( 532 ip6s_m2m[m->m_pkthdr.rcvif->if_index]); 533 else 534 IP6STAT_INC(ip6s_m2m[0]); 535 } else 536 IP6STAT_INC(ip6s_m1); 537 } 538 539 /* drop the packet if IPv6 operation is disabled on the IF */ 540 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) 541 goto bad; 542 543 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); 544 IP6STAT_INC(ip6s_total); 545 546 #ifndef PULLDOWN_TEST 547 /* 548 * L2 bridge code and some other code can return mbuf chain 549 * that does not conform to KAME requirement. too bad. 550 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 551 */ 552 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 553 struct mbuf *n; 554 555 if (m->m_pkthdr.len > MHLEN) 556 n = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 557 else 558 n = m_gethdr(M_NOWAIT, MT_DATA); 559 if (n == NULL) { 560 m_freem(m); 561 return; /* ENOBUFS */ 562 } 563 564 m_move_pkthdr(n, m); 565 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 566 n->m_len = n->m_pkthdr.len; 567 m_freem(m); 568 m = n; 569 } 570 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); 571 #endif 572 573 if (m->m_len < sizeof(struct ip6_hdr)) { 574 struct ifnet *inifp; 575 inifp = m->m_pkthdr.rcvif; 576 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { 577 IP6STAT_INC(ip6s_toosmall); 578 in6_ifstat_inc(inifp, ifs6_in_hdrerr); 579 return; 580 } 581 } 582 583 ip6 = mtod(m, struct ip6_hdr *); 584 585 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 586 IP6STAT_INC(ip6s_badvers); 587 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); 588 goto bad; 589 } 590 591 IP6STAT_INC(ip6s_nxthist[ip6->ip6_nxt]); 592 593 IP_PROBE(receive, NULL, NULL, ip6, m->m_pkthdr.rcvif, NULL, ip6); 594 595 /* 596 * Check against address spoofing/corruption. 597 */ 598 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || 599 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { 600 /* 601 * XXX: "badscope" is not very suitable for a multicast source. 602 */ 603 IP6STAT_INC(ip6s_badscope); 604 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 605 goto bad; 606 } 607 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && 608 !(m->m_flags & M_LOOP)) { 609 /* 610 * In this case, the packet should come from the loopback 611 * interface. However, we cannot just check the if_flags, 612 * because ip6_mloopback() passes the "actual" interface 613 * as the outgoing/incoming interface. 614 */ 615 IP6STAT_INC(ip6s_badscope); 616 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 617 goto bad; 618 } 619 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) && 620 IPV6_ADDR_MC_SCOPE(&ip6->ip6_dst) == 0) { 621 /* 622 * RFC4291 2.7: 623 * Nodes must not originate a packet to a multicast address 624 * whose scop field contains the reserved value 0; if such 625 * a packet is received, it must be silently dropped. 626 */ 627 IP6STAT_INC(ip6s_badscope); 628 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 629 goto bad; 630 } 631 #ifdef ALTQ 632 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { 633 /* packet is dropped by traffic conditioner */ 634 return; 635 } 636 #endif 637 /* 638 * The following check is not documented in specs. A malicious 639 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack 640 * and bypass security checks (act as if it was from 127.0.0.1 by using 641 * IPv6 src ::ffff:127.0.0.1). Be cautious. 642 * 643 * This check chokes if we are in an SIIT cloud. As none of BSDs 644 * support IPv4-less kernel compilation, we cannot support SIIT 645 * environment at all. So, it makes more sense for us to reject any 646 * malicious packets for non-SIIT environment, than try to do a 647 * partial support for SIIT environment. 648 */ 649 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 650 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 651 IP6STAT_INC(ip6s_badscope); 652 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 653 goto bad; 654 } 655 #if 0 656 /* 657 * Reject packets with IPv4 compatible addresses (auto tunnel). 658 * 659 * The code forbids auto tunnel relay case in RFC1933 (the check is 660 * stronger than RFC1933). We may want to re-enable it if mech-xx 661 * is revised to forbid relaying case. 662 */ 663 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || 664 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 665 IP6STAT_INC(ip6s_badscope); 666 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 667 goto bad; 668 } 669 #endif 670 #ifdef IPSEC 671 /* 672 * Bypass packet filtering for packets previously handled by IPsec. 673 */ 674 if (ip6_ipsec_filtertunnel(m)) 675 goto passin; 676 #endif /* IPSEC */ 677 678 /* 679 * Run through list of hooks for input packets. 680 * 681 * NB: Beware of the destination address changing 682 * (e.g. by NAT rewriting). When this happens, 683 * tell ip6_forward to do the right thing. 684 */ 685 odst = ip6->ip6_dst; 686 687 /* Jump over all PFIL processing if hooks are not active. */ 688 if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 689 goto passin; 690 691 if (pfil_run_hooks(&V_inet6_pfil_hook, &m, 692 m->m_pkthdr.rcvif, PFIL_IN, NULL)) 693 return; 694 if (m == NULL) /* consumed by filter */ 695 return; 696 ip6 = mtod(m, struct ip6_hdr *); 697 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); 698 699 if (m->m_flags & M_FASTFWD_OURS) { 700 m->m_flags &= ~M_FASTFWD_OURS; 701 ours = 1; 702 goto hbhcheck; 703 } 704 if ((m->m_flags & M_IP6_NEXTHOP) && 705 m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) { 706 /* 707 * Directly ship the packet on. This allows forwarding 708 * packets originally destined to us to some other directly 709 * connected host. 710 */ 711 ip6_forward(m, 1); 712 return; 713 } 714 715 passin: 716 /* 717 * Disambiguate address scope zones (if there is ambiguity). 718 * We first make sure that the original source or destination address 719 * is not in our internal form for scoped addresses. Such addresses 720 * are not necessarily invalid spec-wise, but we cannot accept them due 721 * to the usage conflict. 722 * in6_setscope() then also checks and rejects the cases where src or 723 * dst are the loopback address and the receiving interface 724 * is not loopback. 725 */ 726 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { 727 IP6STAT_INC(ip6s_badscope); /* XXX */ 728 goto bad; 729 } 730 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || 731 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { 732 IP6STAT_INC(ip6s_badscope); 733 goto bad; 734 } 735 /* 736 * Multicast check. Assume packet is for us to avoid 737 * prematurely taking locks. 738 */ 739 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 740 ours = 1; 741 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); 742 goto hbhcheck; 743 } 744 /* 745 * Unicast check 746 * XXX: For now we keep link-local IPv6 addresses with embedded 747 * scope zone id, therefore we use zero zoneid here. 748 */ 749 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */); 750 if (ia != NULL) { 751 if (ia->ia6_flags & IN6_IFF_NOTREADY) { 752 char ip6bufs[INET6_ADDRSTRLEN]; 753 char ip6bufd[INET6_ADDRSTRLEN]; 754 /* address is not ready, so discard the packet. */ 755 nd6log((LOG_INFO, 756 "ip6_input: packet to an unready address %s->%s\n", 757 ip6_sprintf(ip6bufs, &ip6->ip6_src), 758 ip6_sprintf(ip6bufd, &ip6->ip6_dst))); 759 ifa_free(&ia->ia_ifa); 760 goto bad; 761 } 762 /* Count the packet in the ip address stats */ 763 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1); 764 counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len); 765 ifa_free(&ia->ia_ifa); 766 ours = 1; 767 goto hbhcheck; 768 } 769 770 /* 771 * Now there is no reason to process the packet if it's not our own 772 * and we're not a router. 773 */ 774 if (!V_ip6_forwarding) { 775 IP6STAT_INC(ip6s_cantforward); 776 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 777 goto bad; 778 } 779 780 hbhcheck: 781 /* 782 * Process Hop-by-Hop options header if it's contained. 783 * m may be modified in ip6_hopopts_input(). 784 * If a JumboPayload option is included, plen will also be modified. 785 */ 786 plen = (u_int32_t)ntohs(ip6->ip6_plen); 787 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 788 if (ip6_input_hbh(m, &plen, &rtalert, &off, &nxt, &ours) != 0) 789 return; 790 } else 791 nxt = ip6->ip6_nxt; 792 793 /* 794 * Use mbuf flags to propagate Router Alert option to 795 * ICMPv6 layer, as hop-by-hop options have been stripped. 796 */ 797 if (rtalert != ~0) 798 m->m_flags |= M_RTALERT_MLD; 799 800 /* 801 * Check that the amount of data in the buffers 802 * is as at least much as the IPv6 header would have us expect. 803 * Trim mbufs if longer than we expect. 804 * Drop packet if shorter than we expect. 805 */ 806 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { 807 IP6STAT_INC(ip6s_tooshort); 808 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 809 goto bad; 810 } 811 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { 812 if (m->m_len == m->m_pkthdr.len) { 813 m->m_len = sizeof(struct ip6_hdr) + plen; 814 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; 815 } else 816 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); 817 } 818 819 /* 820 * Forward if desirable. 821 */ 822 if (V_ip6_mrouter && 823 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 824 /* 825 * If we are acting as a multicast router, all 826 * incoming multicast packets are passed to the 827 * kernel-level multicast forwarding function. 828 * The packet is returned (relatively) intact; if 829 * ip6_mforward() returns a non-zero value, the packet 830 * must be discarded, else it may be accepted below. 831 * 832 * XXX TODO: Check hlim and multicast scope here to avoid 833 * unnecessarily calling into ip6_mforward(). 834 */ 835 if (ip6_mforward && 836 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { 837 IP6STAT_INC(ip6s_cantforward); 838 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); 839 goto bad; 840 } 841 } else if (!ours) { 842 ip6_forward(m, srcrt); 843 return; 844 } 845 846 ip6 = mtod(m, struct ip6_hdr *); 847 848 /* 849 * Malicious party may be able to use IPv4 mapped addr to confuse 850 * tcp/udp stack and bypass security checks (act as if it was from 851 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. 852 * 853 * For SIIT end node behavior, you may want to disable the check. 854 * However, you will become vulnerable to attacks using IPv4 mapped 855 * source. 856 */ 857 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || 858 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { 859 IP6STAT_INC(ip6s_badscope); 860 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 861 goto bad; 862 } 863 864 /* 865 * Tell launch routine the next header 866 */ 867 IP6STAT_INC(ip6s_delivered); 868 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_deliver); 869 nest = 0; 870 871 while (nxt != IPPROTO_DONE) { 872 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { 873 IP6STAT_INC(ip6s_toomanyhdr); 874 goto bad; 875 } 876 877 /* 878 * protection against faulty packet - there should be 879 * more sanity checks in header chain processing. 880 */ 881 if (m->m_pkthdr.len < off) { 882 IP6STAT_INC(ip6s_tooshort); 883 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 884 goto bad; 885 } 886 887 #ifdef IPSEC 888 /* 889 * enforce IPsec policy checking if we are seeing last header. 890 * note that we do not visit this with protocols with pcb layer 891 * code - like udp/tcp/raw ip. 892 */ 893 if (ip6_ipsec_input(m, nxt)) 894 goto bad; 895 #endif /* IPSEC */ 896 897 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); 898 } 899 return; 900 bad: 901 m_freem(m); 902 } 903 904 /* 905 * Hop-by-Hop options header processing. If a valid jumbo payload option is 906 * included, the real payload length will be stored in plenp. 907 * 908 * rtalertp - XXX: should be stored more smart way 909 */ 910 static int 911 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, 912 struct mbuf **mp, int *offp) 913 { 914 struct mbuf *m = *mp; 915 int off = *offp, hbhlen; 916 struct ip6_hbh *hbh; 917 918 /* validation of the length of the header */ 919 #ifndef PULLDOWN_TEST 920 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); 921 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 922 hbhlen = (hbh->ip6h_len + 1) << 3; 923 924 IP6_EXTHDR_CHECK(m, off, hbhlen, -1); 925 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); 926 #else 927 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, 928 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); 929 if (hbh == NULL) { 930 IP6STAT_INC(ip6s_tooshort); 931 return -1; 932 } 933 hbhlen = (hbh->ip6h_len + 1) << 3; 934 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), 935 hbhlen); 936 if (hbh == NULL) { 937 IP6STAT_INC(ip6s_tooshort); 938 return -1; 939 } 940 #endif 941 off += hbhlen; 942 hbhlen -= sizeof(struct ip6_hbh); 943 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), 944 hbhlen, rtalertp, plenp) < 0) 945 return (-1); 946 947 *offp = off; 948 *mp = m; 949 return (0); 950 } 951 952 /* 953 * Search header for all Hop-by-hop options and process each option. 954 * This function is separate from ip6_hopopts_input() in order to 955 * handle a case where the sending node itself process its hop-by-hop 956 * options header. In such a case, the function is called from ip6_output(). 957 * 958 * The function assumes that hbh header is located right after the IPv6 header 959 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to 960 * opthead + hbhlen is located in contiguous memory region. 961 */ 962 int 963 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, 964 u_int32_t *rtalertp, u_int32_t *plenp) 965 { 966 struct ip6_hdr *ip6; 967 int optlen = 0; 968 u_int8_t *opt = opthead; 969 u_int16_t rtalert_val; 970 u_int32_t jumboplen; 971 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); 972 973 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { 974 switch (*opt) { 975 case IP6OPT_PAD1: 976 optlen = 1; 977 break; 978 case IP6OPT_PADN: 979 if (hbhlen < IP6OPT_MINLEN) { 980 IP6STAT_INC(ip6s_toosmall); 981 goto bad; 982 } 983 optlen = *(opt + 1) + 2; 984 break; 985 case IP6OPT_ROUTER_ALERT: 986 /* XXX may need check for alignment */ 987 if (hbhlen < IP6OPT_RTALERT_LEN) { 988 IP6STAT_INC(ip6s_toosmall); 989 goto bad; 990 } 991 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { 992 /* XXX stat */ 993 icmp6_error(m, ICMP6_PARAM_PROB, 994 ICMP6_PARAMPROB_HEADER, 995 erroff + opt + 1 - opthead); 996 return (-1); 997 } 998 optlen = IP6OPT_RTALERT_LEN; 999 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); 1000 *rtalertp = ntohs(rtalert_val); 1001 break; 1002 case IP6OPT_JUMBO: 1003 /* XXX may need check for alignment */ 1004 if (hbhlen < IP6OPT_JUMBO_LEN) { 1005 IP6STAT_INC(ip6s_toosmall); 1006 goto bad; 1007 } 1008 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { 1009 /* XXX stat */ 1010 icmp6_error(m, ICMP6_PARAM_PROB, 1011 ICMP6_PARAMPROB_HEADER, 1012 erroff + opt + 1 - opthead); 1013 return (-1); 1014 } 1015 optlen = IP6OPT_JUMBO_LEN; 1016 1017 /* 1018 * IPv6 packets that have non 0 payload length 1019 * must not contain a jumbo payload option. 1020 */ 1021 ip6 = mtod(m, struct ip6_hdr *); 1022 if (ip6->ip6_plen) { 1023 IP6STAT_INC(ip6s_badoptions); 1024 icmp6_error(m, ICMP6_PARAM_PROB, 1025 ICMP6_PARAMPROB_HEADER, 1026 erroff + opt - opthead); 1027 return (-1); 1028 } 1029 1030 /* 1031 * We may see jumbolen in unaligned location, so 1032 * we'd need to perform bcopy(). 1033 */ 1034 bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); 1035 jumboplen = (u_int32_t)htonl(jumboplen); 1036 1037 #if 1 1038 /* 1039 * if there are multiple jumbo payload options, 1040 * *plenp will be non-zero and the packet will be 1041 * rejected. 1042 * the behavior may need some debate in ipngwg - 1043 * multiple options does not make sense, however, 1044 * there's no explicit mention in specification. 1045 */ 1046 if (*plenp != 0) { 1047 IP6STAT_INC(ip6s_badoptions); 1048 icmp6_error(m, ICMP6_PARAM_PROB, 1049 ICMP6_PARAMPROB_HEADER, 1050 erroff + opt + 2 - opthead); 1051 return (-1); 1052 } 1053 #endif 1054 1055 /* 1056 * jumbo payload length must be larger than 65535. 1057 */ 1058 if (jumboplen <= IPV6_MAXPACKET) { 1059 IP6STAT_INC(ip6s_badoptions); 1060 icmp6_error(m, ICMP6_PARAM_PROB, 1061 ICMP6_PARAMPROB_HEADER, 1062 erroff + opt + 2 - opthead); 1063 return (-1); 1064 } 1065 *plenp = jumboplen; 1066 1067 break; 1068 default: /* unknown option */ 1069 if (hbhlen < IP6OPT_MINLEN) { 1070 IP6STAT_INC(ip6s_toosmall); 1071 goto bad; 1072 } 1073 optlen = ip6_unknown_opt(opt, m, 1074 erroff + opt - opthead); 1075 if (optlen == -1) 1076 return (-1); 1077 optlen += 2; 1078 break; 1079 } 1080 } 1081 1082 return (0); 1083 1084 bad: 1085 m_freem(m); 1086 return (-1); 1087 } 1088 1089 /* 1090 * Unknown option processing. 1091 * The third argument `off' is the offset from the IPv6 header to the option, 1092 * which is necessary if the IPv6 header the and option header and IPv6 header 1093 * is not contiguous in order to return an ICMPv6 error. 1094 */ 1095 int 1096 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) 1097 { 1098 struct ip6_hdr *ip6; 1099 1100 switch (IP6OPT_TYPE(*optp)) { 1101 case IP6OPT_TYPE_SKIP: /* ignore the option */ 1102 return ((int)*(optp + 1)); 1103 case IP6OPT_TYPE_DISCARD: /* silently discard */ 1104 m_freem(m); 1105 return (-1); 1106 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ 1107 IP6STAT_INC(ip6s_badoptions); 1108 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); 1109 return (-1); 1110 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ 1111 IP6STAT_INC(ip6s_badoptions); 1112 ip6 = mtod(m, struct ip6_hdr *); 1113 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 1114 (m->m_flags & (M_BCAST|M_MCAST))) 1115 m_freem(m); 1116 else 1117 icmp6_error(m, ICMP6_PARAM_PROB, 1118 ICMP6_PARAMPROB_OPTION, off); 1119 return (-1); 1120 } 1121 1122 m_freem(m); /* XXX: NOTREACHED */ 1123 return (-1); 1124 } 1125 1126 /* 1127 * Create the "control" list for this pcb. 1128 * These functions will not modify mbuf chain at all. 1129 * 1130 * With KAME mbuf chain restriction: 1131 * The routine will be called from upper layer handlers like tcp6_input(). 1132 * Thus the routine assumes that the caller (tcp6_input) have already 1133 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the 1134 * very first mbuf on the mbuf chain. 1135 * 1136 * ip6_savecontrol_v4 will handle those options that are possible to be 1137 * set on a v4-mapped socket. 1138 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those 1139 * options and handle the v6-only ones itself. 1140 */ 1141 struct mbuf ** 1142 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, 1143 int *v4only) 1144 { 1145 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1146 1147 #ifdef SO_TIMESTAMP 1148 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { 1149 struct timeval tv; 1150 1151 microtime(&tv); 1152 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), 1153 SCM_TIMESTAMP, SOL_SOCKET); 1154 if (*mp) 1155 mp = &(*mp)->m_next; 1156 } 1157 #endif 1158 1159 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) 1160 /* RFC 2292 sec. 5 */ 1161 if ((inp->inp_flags & IN6P_PKTINFO) != 0) { 1162 struct in6_pktinfo pi6; 1163 1164 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1165 #ifdef INET 1166 struct ip *ip; 1167 1168 ip = mtod(m, struct ip *); 1169 pi6.ipi6_addr.s6_addr32[0] = 0; 1170 pi6.ipi6_addr.s6_addr32[1] = 0; 1171 pi6.ipi6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP; 1172 pi6.ipi6_addr.s6_addr32[3] = ip->ip_dst.s_addr; 1173 #else 1174 /* We won't hit this code */ 1175 bzero(&pi6.ipi6_addr, sizeof(struct in6_addr)); 1176 #endif 1177 } else { 1178 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); 1179 in6_clearscope(&pi6.ipi6_addr); /* XXX */ 1180 } 1181 pi6.ipi6_ifindex = 1182 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; 1183 1184 *mp = sbcreatecontrol((caddr_t) &pi6, 1185 sizeof(struct in6_pktinfo), 1186 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); 1187 if (*mp) 1188 mp = &(*mp)->m_next; 1189 } 1190 1191 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { 1192 int hlim; 1193 1194 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1195 #ifdef INET 1196 struct ip *ip; 1197 1198 ip = mtod(m, struct ip *); 1199 hlim = ip->ip_ttl; 1200 #else 1201 /* We won't hit this code */ 1202 hlim = 0; 1203 #endif 1204 } else { 1205 hlim = ip6->ip6_hlim & 0xff; 1206 } 1207 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), 1208 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), 1209 IPPROTO_IPV6); 1210 if (*mp) 1211 mp = &(*mp)->m_next; 1212 } 1213 1214 if ((inp->inp_flags & IN6P_TCLASS) != 0) { 1215 int tclass; 1216 1217 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1218 #ifdef INET 1219 struct ip *ip; 1220 1221 ip = mtod(m, struct ip *); 1222 tclass = ip->ip_tos; 1223 #else 1224 /* We won't hit this code */ 1225 tclass = 0; 1226 #endif 1227 } else { 1228 u_int32_t flowinfo; 1229 1230 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); 1231 flowinfo >>= 20; 1232 tclass = flowinfo & 0xff; 1233 } 1234 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(int), 1235 IPV6_TCLASS, IPPROTO_IPV6); 1236 if (*mp) 1237 mp = &(*mp)->m_next; 1238 } 1239 1240 if (v4only != NULL) { 1241 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { 1242 *v4only = 1; 1243 } else { 1244 *v4only = 0; 1245 } 1246 } 1247 1248 return (mp); 1249 } 1250 1251 void 1252 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) 1253 { 1254 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1255 int v4only = 0; 1256 1257 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); 1258 if (v4only) 1259 return; 1260 1261 /* 1262 * IPV6_HOPOPTS socket option. Recall that we required super-user 1263 * privilege for the option (see ip6_ctloutput), but it might be too 1264 * strict, since there might be some hop-by-hop options which can be 1265 * returned to normal user. 1266 * See also RFC 2292 section 6 (or RFC 3542 section 8). 1267 */ 1268 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { 1269 /* 1270 * Check if a hop-by-hop options header is contatined in the 1271 * received packet, and if so, store the options as ancillary 1272 * data. Note that a hop-by-hop options header must be 1273 * just after the IPv6 header, which is assured through the 1274 * IPv6 input processing. 1275 */ 1276 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { 1277 struct ip6_hbh *hbh; 1278 int hbhlen = 0; 1279 #ifdef PULLDOWN_TEST 1280 struct mbuf *ext; 1281 #endif 1282 1283 #ifndef PULLDOWN_TEST 1284 hbh = (struct ip6_hbh *)(ip6 + 1); 1285 hbhlen = (hbh->ip6h_len + 1) << 3; 1286 #else 1287 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), 1288 ip6->ip6_nxt); 1289 if (ext == NULL) { 1290 IP6STAT_INC(ip6s_tooshort); 1291 return; 1292 } 1293 hbh = mtod(ext, struct ip6_hbh *); 1294 hbhlen = (hbh->ip6h_len + 1) << 3; 1295 if (hbhlen != ext->m_len) { 1296 m_freem(ext); 1297 IP6STAT_INC(ip6s_tooshort); 1298 return; 1299 } 1300 #endif 1301 1302 /* 1303 * XXX: We copy the whole header even if a 1304 * jumbo payload option is included, the option which 1305 * is to be removed before returning according to 1306 * RFC2292. 1307 * Note: this constraint is removed in RFC3542 1308 */ 1309 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, 1310 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), 1311 IPPROTO_IPV6); 1312 if (*mp) 1313 mp = &(*mp)->m_next; 1314 #ifdef PULLDOWN_TEST 1315 m_freem(ext); 1316 #endif 1317 } 1318 } 1319 1320 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 1321 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); 1322 1323 /* 1324 * Search for destination options headers or routing 1325 * header(s) through the header chain, and stores each 1326 * header as ancillary data. 1327 * Note that the order of the headers remains in 1328 * the chain of ancillary data. 1329 */ 1330 while (1) { /* is explicit loop prevention necessary? */ 1331 struct ip6_ext *ip6e = NULL; 1332 int elen; 1333 #ifdef PULLDOWN_TEST 1334 struct mbuf *ext = NULL; 1335 #endif 1336 1337 /* 1338 * if it is not an extension header, don't try to 1339 * pull it from the chain. 1340 */ 1341 switch (nxt) { 1342 case IPPROTO_DSTOPTS: 1343 case IPPROTO_ROUTING: 1344 case IPPROTO_HOPOPTS: 1345 case IPPROTO_AH: /* is it possible? */ 1346 break; 1347 default: 1348 goto loopend; 1349 } 1350 1351 #ifndef PULLDOWN_TEST 1352 if (off + sizeof(*ip6e) > m->m_len) 1353 goto loopend; 1354 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); 1355 if (nxt == IPPROTO_AH) 1356 elen = (ip6e->ip6e_len + 2) << 2; 1357 else 1358 elen = (ip6e->ip6e_len + 1) << 3; 1359 if (off + elen > m->m_len) 1360 goto loopend; 1361 #else 1362 ext = ip6_pullexthdr(m, off, nxt); 1363 if (ext == NULL) { 1364 IP6STAT_INC(ip6s_tooshort); 1365 return; 1366 } 1367 ip6e = mtod(ext, struct ip6_ext *); 1368 if (nxt == IPPROTO_AH) 1369 elen = (ip6e->ip6e_len + 2) << 2; 1370 else 1371 elen = (ip6e->ip6e_len + 1) << 3; 1372 if (elen != ext->m_len) { 1373 m_freem(ext); 1374 IP6STAT_INC(ip6s_tooshort); 1375 return; 1376 } 1377 #endif 1378 1379 switch (nxt) { 1380 case IPPROTO_DSTOPTS: 1381 if (!(in6p->inp_flags & IN6P_DSTOPTS)) 1382 break; 1383 1384 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1385 IS2292(in6p, 1386 IPV6_2292DSTOPTS, IPV6_DSTOPTS), 1387 IPPROTO_IPV6); 1388 if (*mp) 1389 mp = &(*mp)->m_next; 1390 break; 1391 case IPPROTO_ROUTING: 1392 if (!(in6p->inp_flags & IN6P_RTHDR)) 1393 break; 1394 1395 *mp = sbcreatecontrol((caddr_t)ip6e, elen, 1396 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR), 1397 IPPROTO_IPV6); 1398 if (*mp) 1399 mp = &(*mp)->m_next; 1400 break; 1401 case IPPROTO_HOPOPTS: 1402 case IPPROTO_AH: /* is it possible? */ 1403 break; 1404 1405 default: 1406 /* 1407 * other cases have been filtered in the above. 1408 * none will visit this case. here we supply 1409 * the code just in case (nxt overwritten or 1410 * other cases). 1411 */ 1412 #ifdef PULLDOWN_TEST 1413 m_freem(ext); 1414 #endif 1415 goto loopend; 1416 1417 } 1418 1419 /* proceed with the next header. */ 1420 off += elen; 1421 nxt = ip6e->ip6e_nxt; 1422 ip6e = NULL; 1423 #ifdef PULLDOWN_TEST 1424 m_freem(ext); 1425 ext = NULL; 1426 #endif 1427 } 1428 loopend: 1429 ; 1430 } 1431 1432 if (in6p->inp_flags2 & INP_RECVFLOWID) { 1433 uint32_t flowid, flow_type; 1434 1435 flowid = m->m_pkthdr.flowid; 1436 flow_type = M_HASHTYPE_GET(m); 1437 1438 /* 1439 * XXX should handle the failure of one or the 1440 * other - don't populate both? 1441 */ 1442 *mp = sbcreatecontrol((caddr_t) &flowid, 1443 sizeof(uint32_t), IPV6_FLOWID, IPPROTO_IPV6); 1444 if (*mp) 1445 mp = &(*mp)->m_next; 1446 *mp = sbcreatecontrol((caddr_t) &flow_type, 1447 sizeof(uint32_t), IPV6_FLOWTYPE, IPPROTO_IPV6); 1448 if (*mp) 1449 mp = &(*mp)->m_next; 1450 } 1451 1452 #ifdef RSS 1453 if (in6p->inp_flags2 & INP_RECVRSSBUCKETID) { 1454 uint32_t flowid, flow_type; 1455 uint32_t rss_bucketid; 1456 1457 flowid = m->m_pkthdr.flowid; 1458 flow_type = M_HASHTYPE_GET(m); 1459 1460 if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) { 1461 *mp = sbcreatecontrol((caddr_t) &rss_bucketid, 1462 sizeof(uint32_t), IPV6_RSSBUCKETID, IPPROTO_IPV6); 1463 if (*mp) 1464 mp = &(*mp)->m_next; 1465 } 1466 } 1467 #endif 1468 1469 } 1470 #undef IS2292 1471 1472 void 1473 ip6_notify_pmtu(struct inpcb *inp, struct sockaddr_in6 *dst, u_int32_t mtu) 1474 { 1475 struct socket *so; 1476 struct mbuf *m_mtu; 1477 struct ip6_mtuinfo mtuctl; 1478 1479 KASSERT(inp != NULL, ("%s: inp == NULL", __func__)); 1480 /* 1481 * Notify the error by sending IPV6_PATHMTU ancillary data if 1482 * application wanted to know the MTU value. 1483 * NOTE: we notify disconnected sockets, because some udp 1484 * applications keep sending sockets disconnected. 1485 * NOTE: our implementation doesn't notify connected sockets that has 1486 * foreign address that is different than given destination addresses 1487 * (this is permitted by RFC 3542). 1488 */ 1489 if ((inp->inp_flags & IN6P_MTU) == 0 || ( 1490 !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && 1491 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &dst->sin6_addr))) 1492 return; 1493 1494 mtuctl.ip6m_mtu = mtu; 1495 mtuctl.ip6m_addr = *dst; 1496 if (sa6_recoverscope(&mtuctl.ip6m_addr)) 1497 return; 1498 1499 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), 1500 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) 1501 return; 1502 1503 so = inp->inp_socket; 1504 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) 1505 == 0) { 1506 m_freem(m_mtu); 1507 /* XXX: should count statistics */ 1508 } else 1509 sorwakeup(so); 1510 } 1511 1512 #ifdef PULLDOWN_TEST 1513 /* 1514 * pull single extension header from mbuf chain. returns single mbuf that 1515 * contains the result, or NULL on error. 1516 */ 1517 static struct mbuf * 1518 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) 1519 { 1520 struct ip6_ext ip6e; 1521 size_t elen; 1522 struct mbuf *n; 1523 1524 #ifdef DIAGNOSTIC 1525 switch (nxt) { 1526 case IPPROTO_DSTOPTS: 1527 case IPPROTO_ROUTING: 1528 case IPPROTO_HOPOPTS: 1529 case IPPROTO_AH: /* is it possible? */ 1530 break; 1531 default: 1532 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); 1533 } 1534 #endif 1535 1536 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1537 if (nxt == IPPROTO_AH) 1538 elen = (ip6e.ip6e_len + 2) << 2; 1539 else 1540 elen = (ip6e.ip6e_len + 1) << 3; 1541 1542 if (elen > MLEN) 1543 n = m_getcl(M_NOWAIT, MT_DATA, 0); 1544 else 1545 n = m_get(M_NOWAIT, MT_DATA); 1546 if (n == NULL) 1547 return NULL; 1548 1549 m_copydata(m, off, elen, mtod(n, caddr_t)); 1550 n->m_len = elen; 1551 return n; 1552 } 1553 #endif 1554 1555 /* 1556 * Get pointer to the previous header followed by the header 1557 * currently processed. 1558 * XXX: This function supposes that 1559 * M includes all headers, 1560 * the next header field and the header length field of each header 1561 * are valid, and 1562 * the sum of each header length equals to OFF. 1563 * Because of these assumptions, this function must be called very 1564 * carefully. Moreover, it will not be used in the near future when 1565 * we develop `neater' mechanism to process extension headers. 1566 */ 1567 char * 1568 ip6_get_prevhdr(const struct mbuf *m, int off) 1569 { 1570 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1571 1572 if (off == sizeof(struct ip6_hdr)) 1573 return (&ip6->ip6_nxt); 1574 else { 1575 int len, nxt; 1576 struct ip6_ext *ip6e = NULL; 1577 1578 nxt = ip6->ip6_nxt; 1579 len = sizeof(struct ip6_hdr); 1580 while (len < off) { 1581 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); 1582 1583 switch (nxt) { 1584 case IPPROTO_FRAGMENT: 1585 len += sizeof(struct ip6_frag); 1586 break; 1587 case IPPROTO_AH: 1588 len += (ip6e->ip6e_len + 2) << 2; 1589 break; 1590 default: 1591 len += (ip6e->ip6e_len + 1) << 3; 1592 break; 1593 } 1594 nxt = ip6e->ip6e_nxt; 1595 } 1596 if (ip6e) 1597 return (&ip6e->ip6e_nxt); 1598 else 1599 return NULL; 1600 } 1601 } 1602 1603 /* 1604 * get next header offset. m will be retained. 1605 */ 1606 int 1607 ip6_nexthdr(const struct mbuf *m, int off, int proto, int *nxtp) 1608 { 1609 struct ip6_hdr ip6; 1610 struct ip6_ext ip6e; 1611 struct ip6_frag fh; 1612 1613 /* just in case */ 1614 if (m == NULL) 1615 panic("ip6_nexthdr: m == NULL"); 1616 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) 1617 return -1; 1618 1619 switch (proto) { 1620 case IPPROTO_IPV6: 1621 if (m->m_pkthdr.len < off + sizeof(ip6)) 1622 return -1; 1623 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); 1624 if (nxtp) 1625 *nxtp = ip6.ip6_nxt; 1626 off += sizeof(ip6); 1627 return off; 1628 1629 case IPPROTO_FRAGMENT: 1630 /* 1631 * terminate parsing if it is not the first fragment, 1632 * it does not make sense to parse through it. 1633 */ 1634 if (m->m_pkthdr.len < off + sizeof(fh)) 1635 return -1; 1636 m_copydata(m, off, sizeof(fh), (caddr_t)&fh); 1637 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ 1638 if (fh.ip6f_offlg & IP6F_OFF_MASK) 1639 return -1; 1640 if (nxtp) 1641 *nxtp = fh.ip6f_nxt; 1642 off += sizeof(struct ip6_frag); 1643 return off; 1644 1645 case IPPROTO_AH: 1646 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1647 return -1; 1648 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1649 if (nxtp) 1650 *nxtp = ip6e.ip6e_nxt; 1651 off += (ip6e.ip6e_len + 2) << 2; 1652 return off; 1653 1654 case IPPROTO_HOPOPTS: 1655 case IPPROTO_ROUTING: 1656 case IPPROTO_DSTOPTS: 1657 if (m->m_pkthdr.len < off + sizeof(ip6e)) 1658 return -1; 1659 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); 1660 if (nxtp) 1661 *nxtp = ip6e.ip6e_nxt; 1662 off += (ip6e.ip6e_len + 1) << 3; 1663 return off; 1664 1665 case IPPROTO_NONE: 1666 case IPPROTO_ESP: 1667 case IPPROTO_IPCOMP: 1668 /* give up */ 1669 return -1; 1670 1671 default: 1672 return -1; 1673 } 1674 1675 /* NOTREACHED */ 1676 } 1677 1678 /* 1679 * get offset for the last header in the chain. m will be kept untainted. 1680 */ 1681 int 1682 ip6_lasthdr(const struct mbuf *m, int off, int proto, int *nxtp) 1683 { 1684 int newoff; 1685 int nxt; 1686 1687 if (!nxtp) { 1688 nxt = -1; 1689 nxtp = &nxt; 1690 } 1691 while (1) { 1692 newoff = ip6_nexthdr(m, off, proto, nxtp); 1693 if (newoff < 0) 1694 return off; 1695 else if (newoff < off) 1696 return -1; /* invalid */ 1697 else if (newoff == off) 1698 return newoff; 1699 1700 off = newoff; 1701 proto = *nxtp; 1702 } 1703 } 1704 1705 /* 1706 * System control for IP6 1707 */ 1708 1709 u_char inet6ctlerrmap[PRC_NCMDS] = { 1710 0, 0, 0, 0, 1711 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, 1712 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 1713 EMSGSIZE, EHOSTUNREACH, 0, 0, 1714 0, 0, 0, 0, 1715 ENOPROTOOPT 1716 }; 1717