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: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $ 30 */ 31 32 /*- 33 * Copyright (c) 1982, 1986, 1991, 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 * @(#)in_pcb.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_mpath.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/lock.h> 73 #include <sys/malloc.h> 74 #include <sys/mbuf.h> 75 #include <sys/priv.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/sockio.h> 80 #include <sys/sysctl.h> 81 #include <sys/errno.h> 82 #include <sys/time.h> 83 #include <sys/kernel.h> 84 #include <sys/sx.h> 85 #include <sys/vimage.h> 86 87 #include <net/if.h> 88 #include <net/route.h> 89 #ifdef RADIX_MPATH 90 #include <net/radix_mpath.h> 91 #endif 92 93 #include <netinet/in.h> 94 #include <netinet/in_var.h> 95 #include <netinet/in_systm.h> 96 #include <netinet/ip.h> 97 #include <netinet/in_pcb.h> 98 #include <netinet/ip_var.h> 99 #include <netinet/udp.h> 100 #include <netinet/udp_var.h> 101 #include <netinet6/in6_var.h> 102 #include <netinet/ip6.h> 103 #include <netinet6/in6_pcb.h> 104 #include <netinet6/ip6_var.h> 105 #include <netinet6/scope6_var.h> 106 #include <netinet6/nd6.h> 107 108 static struct mtx addrsel_lock; 109 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF) 110 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock) 111 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock) 112 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED) 113 114 static struct sx addrsel_sxlock; 115 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock") 116 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock) 117 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock) 118 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock) 119 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock) 120 121 #define ADDR_LABEL_NOTAPP (-1) 122 struct in6_addrpolicy defaultaddrpolicy; 123 124 int ip6_prefer_tempaddr = 0; 125 126 static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *, 127 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 128 struct rtentry **, int, int)); 129 static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *, 130 struct ip6_moptions *, struct route_in6 *ro, struct ifnet **)); 131 132 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); 133 134 static void init_policy_queue(void); 135 static int add_addrsel_policyent(struct in6_addrpolicy *); 136 static int delete_addrsel_policyent(struct in6_addrpolicy *); 137 static int walk_addrsel_policy __P((int (*)(struct in6_addrpolicy *, void *), 138 void *)); 139 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); 140 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); 141 142 /* 143 * Return an IPv6 address, which is the most appropriate for a given 144 * destination and user specified options. 145 * If necessary, this function lookups the routing table and returns 146 * an entry to the caller for later use. 147 */ 148 #define REPLACE(r) do {\ 149 if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \ 150 sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 151 V_ip6stat.ip6s_sources_rule[(r)]++; \ 152 /* { \ 153 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 154 printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \ 155 } */ \ 156 goto replace; \ 157 } while(0) 158 #define NEXT(r) do {\ 159 if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \ 160 sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 161 V_ip6stat.ip6s_sources_rule[(r)]++; \ 162 /* { \ 163 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 164 printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \ 165 } */ \ 166 goto next; /* XXX: we can't use 'continue' here */ \ 167 } while(0) 168 #define BREAK(r) do { \ 169 if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \ 170 sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 171 V_ip6stat.ip6s_sources_rule[(r)]++; \ 172 goto out; /* XXX: we can't use 'break' here */ \ 173 } while(0) 174 175 struct in6_addr * 176 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 177 struct inpcb *inp, struct route_in6 *ro, struct ucred *cred, 178 struct ifnet **ifpp, int *errorp) 179 { 180 INIT_VNET_INET6(curvnet); 181 struct in6_addr dst; 182 struct ifnet *ifp = NULL; 183 struct in6_ifaddr *ia = NULL, *ia_best = NULL; 184 struct in6_pktinfo *pi = NULL; 185 int dst_scope = -1, best_scope = -1, best_matchlen = -1; 186 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; 187 u_int32_t odstzone; 188 int prefer_tempaddr; 189 struct ip6_moptions *mopts; 190 191 dst = dstsock->sin6_addr; /* make a copy for local operation */ 192 *errorp = 0; 193 if (ifpp) 194 *ifpp = NULL; 195 196 if (inp != NULL) { 197 INP_LOCK_ASSERT(inp); 198 mopts = inp->in6p_moptions; 199 } else { 200 mopts = NULL; 201 } 202 203 /* 204 * If the source address is explicitly specified by the caller, 205 * check if the requested source address is indeed a unicast address 206 * assigned to the node, and can be used as the packet's source 207 * address. If everything is okay, use the address as source. 208 */ 209 if (opts && (pi = opts->ip6po_pktinfo) && 210 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 211 struct sockaddr_in6 srcsock; 212 struct in6_ifaddr *ia6; 213 214 /* get the outgoing interface */ 215 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ifp)) 216 != 0) { 217 return (NULL); 218 } 219 220 /* 221 * determine the appropriate zone id of the source based on 222 * the zone of the destination and the outgoing interface. 223 * If the specified address is ambiguous wrt the scope zone, 224 * the interface must be specified; otherwise, ifa_ifwithaddr() 225 * will fail matching the address. 226 */ 227 bzero(&srcsock, sizeof(srcsock)); 228 srcsock.sin6_family = AF_INET6; 229 srcsock.sin6_len = sizeof(srcsock); 230 srcsock.sin6_addr = pi->ipi6_addr; 231 if (ifp) { 232 *errorp = in6_setscope(&srcsock.sin6_addr, ifp, NULL); 233 if (*errorp != 0) 234 return (NULL); 235 } 236 237 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)(&srcsock)); 238 if (ia6 == NULL || 239 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) { 240 *errorp = EADDRNOTAVAIL; 241 return (NULL); 242 } 243 pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ 244 if (ifpp) 245 *ifpp = ifp; 246 return (&ia6->ia_addr.sin6_addr); 247 } 248 249 /* 250 * Otherwise, if the socket has already bound the source, just use it. 251 */ 252 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { 253 return (&inp->in6p_laddr); 254 } 255 256 /* 257 * If the address is not specified, choose the best one based on 258 * the outgoing interface and the destination address. 259 */ 260 /* get the outgoing interface */ 261 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0) 262 return (NULL); 263 264 #ifdef DIAGNOSTIC 265 if (ifp == NULL) /* this should not happen */ 266 panic("in6_selectsrc: NULL ifp"); 267 #endif 268 *errorp = in6_setscope(&dst, ifp, &odstzone); 269 if (*errorp != 0) 270 return (NULL); 271 272 for (ia = V_in6_ifaddr; ia; ia = ia->ia_next) { 273 int new_scope = -1, new_matchlen = -1; 274 struct in6_addrpolicy *new_policy = NULL; 275 u_int32_t srczone, osrczone, dstzone; 276 struct in6_addr src; 277 struct ifnet *ifp1 = ia->ia_ifp; 278 279 /* 280 * We'll never take an address that breaks the scope zone 281 * of the destination. We also skip an address if its zone 282 * does not contain the outgoing interface. 283 * XXX: we should probably use sin6_scope_id here. 284 */ 285 if (in6_setscope(&dst, ifp1, &dstzone) || 286 odstzone != dstzone) { 287 continue; 288 } 289 src = ia->ia_addr.sin6_addr; 290 if (in6_setscope(&src, ifp, &osrczone) || 291 in6_setscope(&src, ifp1, &srczone) || 292 osrczone != srczone) { 293 continue; 294 } 295 296 /* avoid unusable addresses */ 297 if ((ia->ia6_flags & 298 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { 299 continue; 300 } 301 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) 302 continue; 303 304 /* Rule 1: Prefer same address */ 305 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { 306 ia_best = ia; 307 BREAK(1); /* there should be no better candidate */ 308 } 309 310 if (ia_best == NULL) 311 REPLACE(0); 312 313 /* Rule 2: Prefer appropriate scope */ 314 if (dst_scope < 0) 315 dst_scope = in6_addrscope(&dst); 316 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); 317 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { 318 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) 319 REPLACE(2); 320 NEXT(2); 321 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { 322 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) 323 NEXT(2); 324 REPLACE(2); 325 } 326 327 /* 328 * Rule 3: Avoid deprecated addresses. Note that the case of 329 * !ip6_use_deprecated is already rejected above. 330 */ 331 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) 332 NEXT(3); 333 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) 334 REPLACE(3); 335 336 /* Rule 4: Prefer home addresses */ 337 /* 338 * XXX: This is a TODO. We should probably merge the MIP6 339 * case above. 340 */ 341 342 /* Rule 5: Prefer outgoing interface */ 343 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) 344 NEXT(5); 345 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) 346 REPLACE(5); 347 348 /* 349 * Rule 6: Prefer matching label 350 * Note that best_policy should be non-NULL here. 351 */ 352 if (dst_policy == NULL) 353 dst_policy = lookup_addrsel_policy(dstsock); 354 if (dst_policy->label != ADDR_LABEL_NOTAPP) { 355 new_policy = lookup_addrsel_policy(&ia->ia_addr); 356 if (dst_policy->label == best_policy->label && 357 dst_policy->label != new_policy->label) 358 NEXT(6); 359 if (dst_policy->label != best_policy->label && 360 dst_policy->label == new_policy->label) 361 REPLACE(6); 362 } 363 364 /* 365 * Rule 7: Prefer public addresses. 366 * We allow users to reverse the logic by configuring 367 * a sysctl variable, so that privacy conscious users can 368 * always prefer temporary addresses. 369 */ 370 if (opts == NULL || 371 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { 372 prefer_tempaddr = V_ip6_prefer_tempaddr; 373 } else if (opts->ip6po_prefer_tempaddr == 374 IP6PO_TEMPADDR_NOTPREFER) { 375 prefer_tempaddr = 0; 376 } else 377 prefer_tempaddr = 1; 378 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 379 (ia->ia6_flags & IN6_IFF_TEMPORARY)) { 380 if (prefer_tempaddr) 381 REPLACE(7); 382 else 383 NEXT(7); 384 } 385 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 386 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 387 if (prefer_tempaddr) 388 NEXT(7); 389 else 390 REPLACE(7); 391 } 392 393 /* 394 * Rule 8: prefer addresses on alive interfaces. 395 * This is a KAME specific rule. 396 */ 397 if ((ia_best->ia_ifp->if_flags & IFF_UP) && 398 !(ia->ia_ifp->if_flags & IFF_UP)) 399 NEXT(8); 400 if (!(ia_best->ia_ifp->if_flags & IFF_UP) && 401 (ia->ia_ifp->if_flags & IFF_UP)) 402 REPLACE(8); 403 404 /* 405 * Rule 14: Use longest matching prefix. 406 * Note: in the address selection draft, this rule is 407 * documented as "Rule 8". However, since it is also 408 * documented that this rule can be overridden, we assign 409 * a large number so that it is easy to assign smaller numbers 410 * to more preferred rules. 411 */ 412 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); 413 if (best_matchlen < new_matchlen) 414 REPLACE(14); 415 if (new_matchlen < best_matchlen) 416 NEXT(14); 417 418 /* Rule 15 is reserved. */ 419 420 /* 421 * Last resort: just keep the current candidate. 422 * Or, do we need more rules? 423 */ 424 continue; 425 426 replace: 427 ia_best = ia; 428 best_scope = (new_scope >= 0 ? new_scope : 429 in6_addrscope(&ia_best->ia_addr.sin6_addr)); 430 best_policy = (new_policy ? new_policy : 431 lookup_addrsel_policy(&ia_best->ia_addr)); 432 best_matchlen = (new_matchlen >= 0 ? new_matchlen : 433 in6_matchlen(&ia_best->ia_addr.sin6_addr, 434 &dst)); 435 436 next: 437 continue; 438 439 out: 440 break; 441 } 442 443 if ((ia = ia_best) == NULL) { 444 *errorp = EADDRNOTAVAIL; 445 return (NULL); 446 } 447 448 if (ifpp) 449 *ifpp = ifp; 450 451 return (&ia->ia_addr.sin6_addr); 452 } 453 454 /* 455 * clone - meaningful only for bsdi and freebsd 456 */ 457 static int 458 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 459 struct ip6_moptions *mopts, struct route_in6 *ro, 460 struct ifnet **retifp, struct rtentry **retrt, int clone, 461 int norouteok) 462 { 463 INIT_VNET_NET(curvnet); 464 INIT_VNET_INET6(curvnet); 465 int error = 0; 466 struct ifnet *ifp = NULL; 467 struct rtentry *rt = NULL; 468 struct sockaddr_in6 *sin6_next; 469 struct in6_pktinfo *pi = NULL; 470 struct in6_addr *dst = &dstsock->sin6_addr; 471 #if 0 472 char ip6buf[INET6_ADDRSTRLEN]; 473 474 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 475 dstsock->sin6_addr.s6_addr32[1] == 0 && 476 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 477 printf("in6_selectroute: strange destination %s\n", 478 ip6_sprintf(ip6buf, &dstsock->sin6_addr)); 479 } else { 480 printf("in6_selectroute: destination = %s%%%d\n", 481 ip6_sprintf(ip6buf, &dstsock->sin6_addr), 482 dstsock->sin6_scope_id); /* for debug */ 483 } 484 #endif 485 486 /* If the caller specify the outgoing interface explicitly, use it. */ 487 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 488 /* XXX boundary check is assumed to be already done. */ 489 ifp = ifnet_byindex(pi->ipi6_ifindex); 490 if (ifp != NULL && 491 (norouteok || retrt == NULL || 492 IN6_IS_ADDR_MULTICAST(dst))) { 493 /* 494 * we do not have to check or get the route for 495 * multicast. 496 */ 497 goto done; 498 } else 499 goto getroute; 500 } 501 502 /* 503 * If the destination address is a multicast address and the outgoing 504 * interface for the address is specified by the caller, use it. 505 */ 506 if (IN6_IS_ADDR_MULTICAST(dst) && 507 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 508 goto done; /* we do not need a route for multicast. */ 509 } 510 511 getroute: 512 /* 513 * If the next hop address for the packet is specified by the caller, 514 * use it as the gateway. 515 */ 516 if (opts && opts->ip6po_nexthop) { 517 struct route_in6 *ron; 518 519 sin6_next = satosin6(opts->ip6po_nexthop); 520 521 /* at this moment, we only support AF_INET6 next hops */ 522 if (sin6_next->sin6_family != AF_INET6) { 523 error = EAFNOSUPPORT; /* or should we proceed? */ 524 goto done; 525 } 526 527 /* 528 * If the next hop is an IPv6 address, then the node identified 529 * by that address must be a neighbor of the sending host. 530 */ 531 ron = &opts->ip6po_nextroute; 532 if ((ron->ro_rt && 533 (ron->ro_rt->rt_flags & (RTF_UP | RTF_LLINFO)) != 534 (RTF_UP | RTF_LLINFO)) || 535 !IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr, 536 &sin6_next->sin6_addr)) { 537 if (ron->ro_rt) { 538 RTFREE(ron->ro_rt); 539 ron->ro_rt = NULL; 540 } 541 *satosin6(&ron->ro_dst) = *sin6_next; 542 } 543 if (ron->ro_rt == NULL) { 544 rtalloc((struct route *)ron); /* multi path case? */ 545 if (ron->ro_rt == NULL || 546 !(ron->ro_rt->rt_flags & RTF_LLINFO)) { 547 if (ron->ro_rt) { 548 RTFREE(ron->ro_rt); 549 ron->ro_rt = NULL; 550 } 551 error = EHOSTUNREACH; 552 goto done; 553 } 554 } 555 rt = ron->ro_rt; 556 ifp = rt->rt_ifp; 557 558 /* 559 * When cloning is required, try to allocate a route to the 560 * destination so that the caller can store path MTU 561 * information. 562 */ 563 if (!clone) 564 goto done; 565 } 566 567 /* 568 * Use a cached route if it exists and is valid, else try to allocate 569 * a new one. Note that we should check the address family of the 570 * cached destination, in case of sharing the cache with IPv4. 571 */ 572 if (ro) { 573 if (ro->ro_rt && 574 (!(ro->ro_rt->rt_flags & RTF_UP) || 575 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 576 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 577 dst))) { 578 RTFREE(ro->ro_rt); 579 ro->ro_rt = (struct rtentry *)NULL; 580 } 581 if (ro->ro_rt == (struct rtentry *)NULL) { 582 struct sockaddr_in6 *sa6; 583 584 /* No route yet, so try to acquire one */ 585 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 586 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 587 *sa6 = *dstsock; 588 sa6->sin6_scope_id = 0; 589 590 if (clone) { 591 #ifdef RADIX_MPATH 592 rtalloc_mpath((struct route *)ro, 593 ntohl(sa6->sin6_addr.s6_addr32[3])); 594 #else 595 rtalloc((struct route *)ro); 596 #endif 597 } else { 598 ro->ro_rt = rtalloc1(&((struct route *)ro) 599 ->ro_dst, 0, 0UL); 600 if (ro->ro_rt) 601 RT_UNLOCK(ro->ro_rt); 602 } 603 } 604 605 /* 606 * do not care about the result if we have the nexthop 607 * explicitly specified. 608 */ 609 if (opts && opts->ip6po_nexthop) 610 goto done; 611 612 if (ro->ro_rt) { 613 ifp = ro->ro_rt->rt_ifp; 614 615 if (ifp == NULL) { /* can this really happen? */ 616 RTFREE(ro->ro_rt); 617 ro->ro_rt = NULL; 618 } 619 } 620 if (ro->ro_rt == NULL) 621 error = EHOSTUNREACH; 622 rt = ro->ro_rt; 623 624 /* 625 * Check if the outgoing interface conflicts with 626 * the interface specified by ipi6_ifindex (if specified). 627 * Note that loopback interface is always okay. 628 * (this may happen when we are sending a packet to one of 629 * our own addresses.) 630 */ 631 if (ifp && opts && opts->ip6po_pktinfo && 632 opts->ip6po_pktinfo->ipi6_ifindex) { 633 if (!(ifp->if_flags & IFF_LOOPBACK) && 634 ifp->if_index != 635 opts->ip6po_pktinfo->ipi6_ifindex) { 636 error = EHOSTUNREACH; 637 goto done; 638 } 639 } 640 } 641 642 done: 643 if (ifp == NULL && rt == NULL) { 644 /* 645 * This can happen if the caller did not pass a cached route 646 * nor any other hints. We treat this case an error. 647 */ 648 error = EHOSTUNREACH; 649 } 650 if (error == EHOSTUNREACH) 651 V_ip6stat.ip6s_noroute++; 652 653 if (retifp != NULL) 654 *retifp = ifp; 655 if (retrt != NULL) 656 *retrt = rt; /* rt may be NULL */ 657 658 return (error); 659 } 660 661 static int 662 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 663 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp) 664 { 665 int error; 666 struct route_in6 sro; 667 struct rtentry *rt = NULL; 668 669 if (ro == NULL) { 670 bzero(&sro, sizeof(sro)); 671 ro = &sro; 672 } 673 674 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 675 &rt, 0, 1)) != 0) { 676 if (ro == &sro && rt && rt == sro.ro_rt) 677 RTFREE(rt); 678 return (error); 679 } 680 681 /* 682 * do not use a rejected or black hole route. 683 * XXX: this check should be done in the L2 output routine. 684 * However, if we skipped this check here, we'd see the following 685 * scenario: 686 * - install a rejected route for a scoped address prefix 687 * (like fe80::/10) 688 * - send a packet to a destination that matches the scoped prefix, 689 * with ambiguity about the scope zone. 690 * - pick the outgoing interface from the route, and disambiguate the 691 * scope zone with the interface. 692 * - ip6_output() would try to get another route with the "new" 693 * destination, which may be valid. 694 * - we'd see no error on output. 695 * Although this may not be very harmful, it should still be confusing. 696 * We thus reject the case here. 697 */ 698 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) { 699 int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 700 701 if (ro == &sro && rt && rt == sro.ro_rt) 702 RTFREE(rt); 703 return (flags); 704 } 705 706 /* 707 * Adjust the "outgoing" interface. If we're going to loop the packet 708 * back to ourselves, the ifp would be the loopback interface. 709 * However, we'd rather know the interface associated to the 710 * destination address (which should probably be one of our own 711 * addresses.) 712 */ 713 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 714 *retifp = rt->rt_ifa->ifa_ifp; 715 716 if (ro == &sro && rt && rt == sro.ro_rt) 717 RTFREE(rt); 718 return (0); 719 } 720 721 /* 722 * clone - meaningful only for bsdi and freebsd 723 */ 724 int 725 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 726 struct ip6_moptions *mopts, struct route_in6 *ro, 727 struct ifnet **retifp, struct rtentry **retrt, int clone) 728 { 729 730 return (selectroute(dstsock, opts, mopts, ro, retifp, 731 retrt, clone, 0)); 732 } 733 734 /* 735 * Default hop limit selection. The precedence is as follows: 736 * 1. Hoplimit value specified via ioctl. 737 * 2. (If the outgoing interface is detected) the current 738 * hop limit of the interface specified by router advertisement. 739 * 3. The system default hoplimit. 740 */ 741 int 742 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) 743 { 744 INIT_VNET_INET6(curvnet); 745 746 if (in6p && in6p->in6p_hops >= 0) 747 return (in6p->in6p_hops); 748 else if (ifp) 749 return (ND_IFINFO(ifp)->chlim); 750 else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) { 751 struct route_in6 ro6; 752 struct ifnet *lifp; 753 754 bzero(&ro6, sizeof(ro6)); 755 ro6.ro_dst.sin6_family = AF_INET6; 756 ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 757 ro6.ro_dst.sin6_addr = in6p->in6p_faddr; 758 rtalloc((struct route *)&ro6); 759 if (ro6.ro_rt) { 760 lifp = ro6.ro_rt->rt_ifp; 761 RTFREE(ro6.ro_rt); 762 if (lifp) 763 return (ND_IFINFO(lifp)->chlim); 764 } else 765 return (V_ip6_defhlim); 766 } 767 return (V_ip6_defhlim); 768 } 769 770 /* 771 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 772 * share this function by all *bsd*... 773 */ 774 int 775 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred) 776 { 777 INIT_VNET_INET(curvnet); 778 struct socket *so = inp->inp_socket; 779 u_int16_t lport = 0, first, last, *lastport; 780 int count, error = 0, wild = 0, dorandom; 781 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 782 783 INP_INFO_WLOCK_ASSERT(pcbinfo); 784 INP_WLOCK_ASSERT(inp); 785 786 /* XXX: this is redundant when called from in6_pcbbind */ 787 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 788 wild = INPLOOKUP_WILDCARD; 789 790 inp->inp_flags |= INP_ANONPORT; 791 792 if (inp->inp_flags & INP_HIGHPORT) { 793 first = V_ipport_hifirstauto; /* sysctl */ 794 last = V_ipport_hilastauto; 795 lastport = &pcbinfo->ipi_lasthi; 796 } else if (inp->inp_flags & INP_LOWPORT) { 797 error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0); 798 if (error) 799 return error; 800 first = V_ipport_lowfirstauto; /* 1023 */ 801 last = V_ipport_lowlastauto; /* 600 */ 802 lastport = &pcbinfo->ipi_lastlow; 803 } else { 804 first = V_ipport_firstauto; /* sysctl */ 805 last = V_ipport_lastauto; 806 lastport = &pcbinfo->ipi_lastport; 807 } 808 809 /* 810 * For UDP, use random port allocation as long as the user 811 * allows it. For TCP (and as of yet unknown) connections, 812 * use random port allocation only if the user allows it AND 813 * ipport_tick() allows it. 814 */ 815 if (V_ipport_randomized && 816 (!V_ipport_stoprandom || pcbinfo == &V_udbinfo)) 817 dorandom = 1; 818 else 819 dorandom = 0; 820 /* 821 * It makes no sense to do random port allocation if 822 * we have the only port available. 823 */ 824 if (first == last) 825 dorandom = 0; 826 /* Make sure to not include UDP packets in the count. */ 827 if (pcbinfo != &V_udbinfo) 828 V_ipport_tcpallocs++; 829 830 /* 831 * Instead of having two loops further down counting up or down 832 * make sure that first is always <= last and go with only one 833 * code path implementing all logic. 834 */ 835 if (first > last) { 836 u_int16_t aux; 837 838 aux = first; 839 first = last; 840 last = aux; 841 } 842 843 if (dorandom) 844 *lastport = first + (arc4random() % (last - first)); 845 846 count = last - first; 847 848 do { 849 if (count-- < 0) { /* completely used? */ 850 /* Undo an address bind that may have occurred. */ 851 inp->in6p_laddr = in6addr_any; 852 return (EADDRNOTAVAIL); 853 } 854 ++*lastport; 855 if (*lastport < first || *lastport > last) 856 *lastport = first; 857 lport = htons(*lastport); 858 } while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, 859 lport, wild, cred)); 860 861 inp->inp_lport = lport; 862 if (in_pcbinshash(inp) != 0) { 863 inp->in6p_laddr = in6addr_any; 864 inp->inp_lport = 0; 865 return (EAGAIN); 866 } 867 868 return (0); 869 } 870 871 void 872 addrsel_policy_init(void) 873 { 874 ADDRSEL_LOCK_INIT(); 875 ADDRSEL_SXLOCK_INIT(); 876 INIT_VNET_INET6(curvnet); 877 878 init_policy_queue(); 879 880 /* initialize the "last resort" policy */ 881 bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy)); 882 V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; 883 } 884 885 static struct in6_addrpolicy * 886 lookup_addrsel_policy(struct sockaddr_in6 *key) 887 { 888 INIT_VNET_INET6(curvnet); 889 struct in6_addrpolicy *match = NULL; 890 891 ADDRSEL_LOCK(); 892 match = match_addrsel_policy(key); 893 894 if (match == NULL) 895 match = &V_defaultaddrpolicy; 896 else 897 match->use++; 898 ADDRSEL_UNLOCK(); 899 900 return (match); 901 } 902 903 /* 904 * Subroutines to manage the address selection policy table via sysctl. 905 */ 906 struct walkarg { 907 struct sysctl_req *w_req; 908 }; 909 910 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); 911 SYSCTL_DECL(_net_inet6_ip6); 912 SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, 913 CTLFLAG_RD, in6_src_sysctl, ""); 914 915 static int 916 in6_src_sysctl(SYSCTL_HANDLER_ARGS) 917 { 918 struct walkarg w; 919 920 if (req->newptr) 921 return EPERM; 922 923 bzero(&w, sizeof(w)); 924 w.w_req = req; 925 926 return (walk_addrsel_policy(dump_addrsel_policyent, &w)); 927 } 928 929 int 930 in6_src_ioctl(u_long cmd, caddr_t data) 931 { 932 int i; 933 struct in6_addrpolicy ent0; 934 935 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) 936 return (EOPNOTSUPP); /* check for safety */ 937 938 ent0 = *(struct in6_addrpolicy *)data; 939 940 if (ent0.label == ADDR_LABEL_NOTAPP) 941 return (EINVAL); 942 /* check if the prefix mask is consecutive. */ 943 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) 944 return (EINVAL); 945 /* clear trailing garbages (if any) of the prefix address. */ 946 for (i = 0; i < 4; i++) { 947 ent0.addr.sin6_addr.s6_addr32[i] &= 948 ent0.addrmask.sin6_addr.s6_addr32[i]; 949 } 950 ent0.use = 0; 951 952 switch (cmd) { 953 case SIOCAADDRCTL_POLICY: 954 return (add_addrsel_policyent(&ent0)); 955 case SIOCDADDRCTL_POLICY: 956 return (delete_addrsel_policyent(&ent0)); 957 } 958 959 return (0); /* XXX: compromise compilers */ 960 } 961 962 /* 963 * The followings are implementation of the policy table using a 964 * simple tail queue. 965 * XXX such details should be hidden. 966 * XXX implementation using binary tree should be more efficient. 967 */ 968 struct addrsel_policyent { 969 TAILQ_ENTRY(addrsel_policyent) ape_entry; 970 struct in6_addrpolicy ape_policy; 971 }; 972 973 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); 974 975 struct addrsel_policyhead addrsel_policytab; 976 977 static void 978 init_policy_queue(void) 979 { 980 INIT_VNET_INET6(curvnet); 981 982 TAILQ_INIT(&V_addrsel_policytab); 983 } 984 985 static int 986 add_addrsel_policyent(struct in6_addrpolicy *newpolicy) 987 { 988 INIT_VNET_INET6(curvnet); 989 struct addrsel_policyent *new, *pol; 990 991 new = malloc(sizeof(*new), M_IFADDR, 992 M_WAITOK); 993 ADDRSEL_XLOCK(); 994 ADDRSEL_LOCK(); 995 996 /* duplication check */ 997 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 998 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, 999 &pol->ape_policy.addr.sin6_addr) && 1000 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, 1001 &pol->ape_policy.addrmask.sin6_addr)) { 1002 ADDRSEL_UNLOCK(); 1003 ADDRSEL_XUNLOCK(); 1004 free(new, M_IFADDR); 1005 return (EEXIST); /* or override it? */ 1006 } 1007 } 1008 1009 bzero(new, sizeof(*new)); 1010 1011 /* XXX: should validate entry */ 1012 new->ape_policy = *newpolicy; 1013 1014 TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry); 1015 ADDRSEL_UNLOCK(); 1016 ADDRSEL_XUNLOCK(); 1017 1018 return (0); 1019 } 1020 1021 static int 1022 delete_addrsel_policyent(struct in6_addrpolicy *key) 1023 { 1024 INIT_VNET_INET6(curvnet); 1025 struct addrsel_policyent *pol; 1026 1027 ADDRSEL_XLOCK(); 1028 ADDRSEL_LOCK(); 1029 1030 /* search for the entry in the table */ 1031 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1032 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, 1033 &pol->ape_policy.addr.sin6_addr) && 1034 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, 1035 &pol->ape_policy.addrmask.sin6_addr)) { 1036 break; 1037 } 1038 } 1039 if (pol == NULL) { 1040 ADDRSEL_UNLOCK(); 1041 ADDRSEL_XUNLOCK(); 1042 return (ESRCH); 1043 } 1044 1045 TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry); 1046 ADDRSEL_UNLOCK(); 1047 ADDRSEL_XUNLOCK(); 1048 1049 return (0); 1050 } 1051 1052 static int 1053 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), 1054 void *w) 1055 { 1056 INIT_VNET_INET6(curvnet); 1057 struct addrsel_policyent *pol; 1058 int error = 0; 1059 1060 ADDRSEL_SLOCK(); 1061 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1062 if ((error = (*callback)(&pol->ape_policy, w)) != 0) { 1063 ADDRSEL_SUNLOCK(); 1064 return (error); 1065 } 1066 } 1067 ADDRSEL_SUNLOCK(); 1068 return (error); 1069 } 1070 1071 static int 1072 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) 1073 { 1074 int error = 0; 1075 struct walkarg *w = arg; 1076 1077 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); 1078 1079 return (error); 1080 } 1081 1082 static struct in6_addrpolicy * 1083 match_addrsel_policy(struct sockaddr_in6 *key) 1084 { 1085 INIT_VNET_INET6(curvnet); 1086 struct addrsel_policyent *pent; 1087 struct in6_addrpolicy *bestpol = NULL, *pol; 1088 int matchlen, bestmatchlen = -1; 1089 u_char *mp, *ep, *k, *p, m; 1090 1091 TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) { 1092 matchlen = 0; 1093 1094 pol = &pent->ape_policy; 1095 mp = (u_char *)&pol->addrmask.sin6_addr; 1096 ep = mp + 16; /* XXX: scope field? */ 1097 k = (u_char *)&key->sin6_addr; 1098 p = (u_char *)&pol->addr.sin6_addr; 1099 for (; mp < ep && *mp; mp++, k++, p++) { 1100 m = *mp; 1101 if ((*k & m) != *p) 1102 goto next; /* not match */ 1103 if (m == 0xff) /* short cut for a typical case */ 1104 matchlen += 8; 1105 else { 1106 while (m >= 0x80) { 1107 matchlen++; 1108 m <<= 1; 1109 } 1110 } 1111 } 1112 1113 /* matched. check if this is better than the current best. */ 1114 if (bestpol == NULL || 1115 matchlen > bestmatchlen) { 1116 bestpol = pol; 1117 bestmatchlen = matchlen; 1118 } 1119 1120 next: 1121 continue; 1122 } 1123 1124 return (bestpol); 1125 } 1126