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