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sys/netinet6/in6_src.c
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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: releng/7.3/sys/netinet6/in6_src.c 202924 2010-01-24 14:05:56Z bz $"); 65 66 #include "opt_inet.h" 67 #include "opt_inet6.h" 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/lock.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/priv.h> 75 #include <sys/protosw.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/sockio.h> 79 #include <sys/sysctl.h> 80 #include <sys/errno.h> 81 #include <sys/time.h> 82 #include <sys/jail.h> 83 #include <sys/kernel.h> 84 #include <sys/sx.h> 85 86 #include <net/if.h> 87 #include <net/route.h> 88 89 #include <netinet/in.h> 90 #include <netinet/in_var.h> 91 #include <netinet/in_systm.h> 92 #include <netinet/ip.h> 93 #include <netinet/in_pcb.h> 94 #include <netinet/ip_var.h> 95 #include <netinet/udp.h> 96 #include <netinet/udp_var.h> 97 #include <netinet6/in6_var.h> 98 #include <netinet/ip6.h> 99 #include <netinet6/in6_pcb.h> 100 #include <netinet6/ip6_var.h> 101 #include <netinet6/scope6_var.h> 102 #include <netinet6/nd6.h> 103 104 static struct mtx addrsel_lock; 105 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF) 106 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock) 107 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock) 108 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED) 109 110 static struct sx addrsel_sxlock; 111 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock") 112 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock) 113 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock) 114 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock) 115 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock) 116 117 #define ADDR_LABEL_NOTAPP (-1) 118 struct in6_addrpolicy defaultaddrpolicy; 119 120 int ip6_prefer_tempaddr = 0; 121 122 static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *, 123 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 124 struct rtentry **, int, int)); 125 static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *, 126 struct ip6_moptions *, struct route_in6 *ro, struct ifnet **)); 127 128 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); 129 130 static void init_policy_queue(void); 131 static int add_addrsel_policyent(struct in6_addrpolicy *); 132 static int delete_addrsel_policyent(struct in6_addrpolicy *); 133 static int walk_addrsel_policy __P((int (*)(struct in6_addrpolicy *, void *), 134 void *)); 135 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); 136 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); 137 138 /* 139 * Return an IPv6 address, which is the most appropriate for a given 140 * destination and user specified options. 141 * If necessary, this function lookups the routing table and returns 142 * an entry to the caller for later use. 143 */ 144 #define REPLACE(r) do {\ 145 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ 146 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 147 ip6stat.ip6s_sources_rule[(r)]++; \ 148 /* { \ 149 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 150 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)); \ 151 } */ \ 152 goto replace; \ 153 } while(0) 154 #define NEXT(r) do {\ 155 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ 156 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 157 ip6stat.ip6s_sources_rule[(r)]++; \ 158 /* { \ 159 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 160 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)); \ 161 } */ \ 162 goto next; /* XXX: we can't use 'continue' here */ \ 163 } while(0) 164 #define BREAK(r) do { \ 165 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \ 166 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \ 167 ip6stat.ip6s_sources_rule[(r)]++; \ 168 goto out; /* XXX: we can't use 'break' here */ \ 169 } while(0) 170 171 int 172 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 173 struct inpcb *inp, struct route_in6 *ro, struct ucred *cred, 174 struct ifnet **ifpp, struct in6_addr *srcp) 175 { 176 struct in6_addr dst; 177 struct ifnet *ifp = NULL; 178 struct in6_ifaddr *ia = NULL, *ia_best = NULL; 179 struct in6_pktinfo *pi = NULL; 180 int dst_scope = -1, best_scope = -1, best_matchlen = -1; 181 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; 182 u_int32_t odstzone; 183 int prefer_tempaddr; 184 int error; 185 struct ip6_moptions *mopts; 186 187 KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__)); 188 189 dst = dstsock->sin6_addr; /* make a copy for local operation */ 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 ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0) 213 return (error); 214 215 /* 216 * determine the appropriate zone id of the source based on 217 * the zone of the destination and the outgoing interface. 218 * If the specified address is ambiguous wrt the scope zone, 219 * the interface must be specified; otherwise, ifa_ifwithaddr() 220 * will fail matching the address. 221 */ 222 bzero(&srcsock, sizeof(srcsock)); 223 srcsock.sin6_family = AF_INET6; 224 srcsock.sin6_len = sizeof(srcsock); 225 srcsock.sin6_addr = pi->ipi6_addr; 226 if (ifp) { 227 error = in6_setscope(&srcsock.sin6_addr, ifp, NULL); 228 if (error) 229 return (error); 230 } 231 if (cred != NULL && (error = prison_local_ip6(cred, 232 &srcsock.sin6_addr, (inp != NULL && 233 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 234 return (error); 235 236 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)(&srcsock)); 237 if (ia6 == NULL || 238 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) { 239 return (EADDRNOTAVAIL); 240 } 241 pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ 242 if (ifpp) 243 *ifpp = ifp; 244 bcopy(&ia6->ia_addr.sin6_addr, srcp, sizeof(*srcp)); 245 return (0); 246 } 247 248 /* 249 * Otherwise, if the socket has already bound the source, just use it. 250 */ 251 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { 252 if (cred != NULL && 253 (error = prison_local_ip6(cred, &inp->in6p_laddr, 254 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 255 return (error); 256 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp)); 257 return (0); 258 } 259 260 /* 261 * Bypass source address selection and use the primary jail IP 262 * if requested. 263 */ 264 if (cred != NULL && !prison_saddrsel_ip6(cred, srcp)) 265 return (0); 266 267 /* 268 * If the address is not specified, choose the best one based on 269 * the outgoing interface and the destination address. 270 */ 271 /* get the outgoing interface */ 272 if ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0) 273 return (error); 274 275 #ifdef DIAGNOSTIC 276 if (ifp == NULL) /* this should not happen */ 277 panic("in6_selectsrc: NULL ifp"); 278 #endif 279 error = in6_setscope(&dst, ifp, &odstzone); 280 if (error) 281 return (error); 282 283 for (ia = in6_ifaddr; ia; ia = ia->ia_next) { 284 int new_scope = -1, new_matchlen = -1; 285 struct in6_addrpolicy *new_policy = NULL; 286 u_int32_t srczone, osrczone, dstzone; 287 struct in6_addr src; 288 struct ifnet *ifp1 = ia->ia_ifp; 289 290 /* 291 * We'll never take an address that breaks the scope zone 292 * of the destination. We also skip an address if its zone 293 * does not contain the outgoing interface. 294 * XXX: we should probably use sin6_scope_id here. 295 */ 296 if (in6_setscope(&dst, ifp1, &dstzone) || 297 odstzone != dstzone) { 298 continue; 299 } 300 src = ia->ia_addr.sin6_addr; 301 if (in6_setscope(&src, ifp, &osrczone) || 302 in6_setscope(&src, ifp1, &srczone) || 303 osrczone != srczone) { 304 continue; 305 } 306 307 /* avoid unusable addresses */ 308 if ((ia->ia6_flags & 309 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { 310 continue; 311 } 312 if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) 313 continue; 314 315 if (cred != NULL && 316 prison_local_ip6(cred, &ia->ia_addr.sin6_addr, 317 (inp != NULL && 318 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) 319 continue; 320 321 /* Rule 1: Prefer same address */ 322 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { 323 ia_best = ia; 324 BREAK(1); /* there should be no better candidate */ 325 } 326 327 if (ia_best == NULL) 328 REPLACE(0); 329 330 /* Rule 2: Prefer appropriate scope */ 331 if (dst_scope < 0) 332 dst_scope = in6_addrscope(&dst); 333 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); 334 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { 335 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) 336 REPLACE(2); 337 NEXT(2); 338 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { 339 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) 340 NEXT(2); 341 REPLACE(2); 342 } 343 344 /* 345 * Rule 3: Avoid deprecated addresses. Note that the case of 346 * !ip6_use_deprecated is already rejected above. 347 */ 348 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) 349 NEXT(3); 350 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) 351 REPLACE(3); 352 353 /* Rule 4: Prefer home addresses */ 354 /* 355 * XXX: This is a TODO. We should probably merge the MIP6 356 * case above. 357 */ 358 359 /* Rule 5: Prefer outgoing interface */ 360 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) 361 NEXT(5); 362 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) 363 REPLACE(5); 364 365 /* 366 * Rule 6: Prefer matching label 367 * Note that best_policy should be non-NULL here. 368 */ 369 if (dst_policy == NULL) 370 dst_policy = lookup_addrsel_policy(dstsock); 371 if (dst_policy->label != ADDR_LABEL_NOTAPP) { 372 new_policy = lookup_addrsel_policy(&ia->ia_addr); 373 if (dst_policy->label == best_policy->label && 374 dst_policy->label != new_policy->label) 375 NEXT(6); 376 if (dst_policy->label != best_policy->label && 377 dst_policy->label == new_policy->label) 378 REPLACE(6); 379 } 380 381 /* 382 * Rule 7: Prefer public addresses. 383 * We allow users to reverse the logic by configuring 384 * a sysctl variable, so that privacy conscious users can 385 * always prefer temporary addresses. 386 */ 387 if (opts == NULL || 388 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { 389 prefer_tempaddr = ip6_prefer_tempaddr; 390 } else if (opts->ip6po_prefer_tempaddr == 391 IP6PO_TEMPADDR_NOTPREFER) { 392 prefer_tempaddr = 0; 393 } else 394 prefer_tempaddr = 1; 395 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 396 (ia->ia6_flags & IN6_IFF_TEMPORARY)) { 397 if (prefer_tempaddr) 398 REPLACE(7); 399 else 400 NEXT(7); 401 } 402 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 403 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 404 if (prefer_tempaddr) 405 NEXT(7); 406 else 407 REPLACE(7); 408 } 409 410 /* 411 * Rule 8: prefer addresses on alive interfaces. 412 * This is a KAME specific rule. 413 */ 414 if ((ia_best->ia_ifp->if_flags & IFF_UP) && 415 !(ia->ia_ifp->if_flags & IFF_UP)) 416 NEXT(8); 417 if (!(ia_best->ia_ifp->if_flags & IFF_UP) && 418 (ia->ia_ifp->if_flags & IFF_UP)) 419 REPLACE(8); 420 421 /* 422 * Rule 14: Use longest matching prefix. 423 * Note: in the address selection draft, this rule is 424 * documented as "Rule 8". However, since it is also 425 * documented that this rule can be overridden, we assign 426 * a large number so that it is easy to assign smaller numbers 427 * to more preferred rules. 428 */ 429 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); 430 if (best_matchlen < new_matchlen) 431 REPLACE(14); 432 if (new_matchlen < best_matchlen) 433 NEXT(14); 434 435 /* Rule 15 is reserved. */ 436 437 /* 438 * Last resort: just keep the current candidate. 439 * Or, do we need more rules? 440 */ 441 continue; 442 443 replace: 444 ia_best = ia; 445 best_scope = (new_scope >= 0 ? new_scope : 446 in6_addrscope(&ia_best->ia_addr.sin6_addr)); 447 best_policy = (new_policy ? new_policy : 448 lookup_addrsel_policy(&ia_best->ia_addr)); 449 best_matchlen = (new_matchlen >= 0 ? new_matchlen : 450 in6_matchlen(&ia_best->ia_addr.sin6_addr, 451 &dst)); 452 453 next: 454 continue; 455 456 out: 457 break; 458 } 459 460 if ((ia = ia_best) == NULL) 461 return (EADDRNOTAVAIL); 462 463 if (ifpp) 464 *ifpp = ifp; 465 466 bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp)); 467 return (0); 468 } 469 470 /* 471 * clone - meaningful only for bsdi and freebsd 472 */ 473 static int 474 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 475 struct ip6_moptions *mopts, struct route_in6 *ro, 476 struct ifnet **retifp, struct rtentry **retrt, int clone, 477 int norouteok) 478 { 479 int error = 0; 480 struct ifnet *ifp = NULL; 481 struct rtentry *rt = NULL; 482 struct sockaddr_in6 *sin6_next; 483 struct in6_pktinfo *pi = NULL; 484 struct in6_addr *dst = &dstsock->sin6_addr; 485 #if 0 486 char ip6buf[INET6_ADDRSTRLEN]; 487 488 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 489 dstsock->sin6_addr.s6_addr32[1] == 0 && 490 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 491 printf("in6_selectroute: strange destination %s\n", 492 ip6_sprintf(ip6buf, &dstsock->sin6_addr)); 493 } else { 494 printf("in6_selectroute: destination = %s%%%d\n", 495 ip6_sprintf(ip6buf, &dstsock->sin6_addr), 496 dstsock->sin6_scope_id); /* for debug */ 497 } 498 #endif 499 500 /* If the caller specify the outgoing interface explicitly, use it. */ 501 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 502 /* XXX boundary check is assumed to be already done. */ 503 ifp = ifnet_byindex(pi->ipi6_ifindex); 504 if (ifp != NULL && 505 (norouteok || retrt == NULL || 506 IN6_IS_ADDR_MULTICAST(dst))) { 507 /* 508 * we do not have to check or get the route for 509 * multicast. 510 */ 511 goto done; 512 } else 513 goto getroute; 514 } 515 516 /* 517 * If the destination address is a multicast address and the outgoing 518 * interface for the address is specified by the caller, use it. 519 */ 520 if (IN6_IS_ADDR_MULTICAST(dst) && 521 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 522 goto done; /* we do not need a route for multicast. */ 523 } 524 525 getroute: 526 /* 527 * If the next hop address for the packet is specified by the caller, 528 * use it as the gateway. 529 */ 530 if (opts && opts->ip6po_nexthop) { 531 struct route_in6 *ron; 532 533 sin6_next = satosin6(opts->ip6po_nexthop); 534 535 /* at this moment, we only support AF_INET6 next hops */ 536 if (sin6_next->sin6_family != AF_INET6) { 537 error = EAFNOSUPPORT; /* or should we proceed? */ 538 goto done; 539 } 540 541 /* 542 * If the next hop is an IPv6 address, then the node identified 543 * by that address must be a neighbor of the sending host. 544 */ 545 ron = &opts->ip6po_nextroute; 546 if ((ron->ro_rt && 547 (ron->ro_rt->rt_flags & (RTF_UP | RTF_LLINFO)) != 548 (RTF_UP | RTF_LLINFO)) || 549 !IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr, 550 &sin6_next->sin6_addr)) { 551 if (ron->ro_rt) { 552 RTFREE(ron->ro_rt); 553 ron->ro_rt = NULL; 554 } 555 *satosin6(&ron->ro_dst) = *sin6_next; 556 } 557 if (ron->ro_rt == NULL) { 558 rtalloc((struct route *)ron); /* multi path case? */ 559 if (ron->ro_rt == NULL || 560 !(ron->ro_rt->rt_flags & RTF_LLINFO)) { 561 if (ron->ro_rt) { 562 RTFREE(ron->ro_rt); 563 ron->ro_rt = NULL; 564 } 565 error = EHOSTUNREACH; 566 goto done; 567 } 568 } 569 rt = ron->ro_rt; 570 ifp = rt->rt_ifp; 571 572 /* 573 * When cloning is required, try to allocate a route to the 574 * destination so that the caller can store path MTU 575 * information. 576 */ 577 if (!clone) 578 goto done; 579 } 580 581 /* 582 * Use a cached route if it exists and is valid, else try to allocate 583 * a new one. Note that we should check the address family of the 584 * cached destination, in case of sharing the cache with IPv4. 585 */ 586 if (ro) { 587 if (ro->ro_rt && 588 (!(ro->ro_rt->rt_flags & RTF_UP) || 589 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 590 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 591 dst))) { 592 RTFREE(ro->ro_rt); 593 ro->ro_rt = (struct rtentry *)NULL; 594 } 595 if (ro->ro_rt == (struct rtentry *)NULL) { 596 struct sockaddr_in6 *sa6; 597 598 /* No route yet, so try to acquire one */ 599 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 600 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 601 *sa6 = *dstsock; 602 sa6->sin6_scope_id = 0; 603 604 if (clone) { 605 rtalloc((struct route *)ro); 606 } else { 607 ro->ro_rt = rtalloc1(&((struct route *)ro) 608 ->ro_dst, 0, 0UL); 609 if (ro->ro_rt) 610 RT_UNLOCK(ro->ro_rt); 611 } 612 } 613 614 /* 615 * do not care about the result if we have the nexthop 616 * explicitly specified. 617 */ 618 if (opts && opts->ip6po_nexthop) 619 goto done; 620 621 if (ro->ro_rt) { 622 ifp = ro->ro_rt->rt_ifp; 623 624 if (ifp == NULL) { /* can this really happen? */ 625 RTFREE(ro->ro_rt); 626 ro->ro_rt = NULL; 627 } 628 } 629 if (ro->ro_rt == NULL) 630 error = EHOSTUNREACH; 631 rt = ro->ro_rt; 632 633 /* 634 * Check if the outgoing interface conflicts with 635 * the interface specified by ipi6_ifindex (if specified). 636 * Note that loopback interface is always okay. 637 * (this may happen when we are sending a packet to one of 638 * our own addresses.) 639 */ 640 if (ifp && opts && opts->ip6po_pktinfo && 641 opts->ip6po_pktinfo->ipi6_ifindex) { 642 if (!(ifp->if_flags & IFF_LOOPBACK) && 643 ifp->if_index != 644 opts->ip6po_pktinfo->ipi6_ifindex) { 645 error = EHOSTUNREACH; 646 goto done; 647 } 648 } 649 } 650 651 done: 652 if (ifp == NULL && rt == NULL) { 653 /* 654 * This can happen if the caller did not pass a cached route 655 * nor any other hints. We treat this case an error. 656 */ 657 error = EHOSTUNREACH; 658 } 659 if (error == EHOSTUNREACH) 660 ip6stat.ip6s_noroute++; 661 662 if (retifp != NULL) 663 *retifp = ifp; 664 if (retrt != NULL) 665 *retrt = rt; /* rt may be NULL */ 666 667 return (error); 668 } 669 670 static int 671 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 672 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp) 673 { 674 int error; 675 struct route_in6 sro; 676 struct rtentry *rt = NULL; 677 678 if (ro == NULL) { 679 bzero(&sro, sizeof(sro)); 680 ro = &sro; 681 } 682 683 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 684 &rt, 0, 1)) != 0) { 685 if (ro == &sro && rt && rt == sro.ro_rt) 686 RTFREE(rt); 687 return (error); 688 } 689 690 /* 691 * do not use a rejected or black hole route. 692 * XXX: this check should be done in the L2 output routine. 693 * However, if we skipped this check here, we'd see the following 694 * scenario: 695 * - install a rejected route for a scoped address prefix 696 * (like fe80::/10) 697 * - send a packet to a destination that matches the scoped prefix, 698 * with ambiguity about the scope zone. 699 * - pick the outgoing interface from the route, and disambiguate the 700 * scope zone with the interface. 701 * - ip6_output() would try to get another route with the "new" 702 * destination, which may be valid. 703 * - we'd see no error on output. 704 * Although this may not be very harmful, it should still be confusing. 705 * We thus reject the case here. 706 */ 707 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) { 708 int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 709 710 if (ro == &sro && rt && rt == sro.ro_rt) 711 RTFREE(rt); 712 return (flags); 713 } 714 715 /* 716 * Adjust the "outgoing" interface. If we're going to loop the packet 717 * back to ourselves, the ifp would be the loopback interface. 718 * However, we'd rather know the interface associated to the 719 * destination address (which should probably be one of our own 720 * addresses.) 721 */ 722 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp) 723 *retifp = rt->rt_ifa->ifa_ifp; 724 725 if (ro == &sro && rt && rt == sro.ro_rt) 726 RTFREE(rt); 727 return (0); 728 } 729 730 /* 731 * clone - meaningful only for bsdi and freebsd 732 */ 733 int 734 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 735 struct ip6_moptions *mopts, struct route_in6 *ro, 736 struct ifnet **retifp, struct rtentry **retrt, int clone) 737 { 738 739 return (selectroute(dstsock, opts, mopts, ro, retifp, 740 retrt, clone, 0)); 741 } 742 743 /* 744 * Default hop limit selection. The precedence is as follows: 745 * 1. Hoplimit value specified via ioctl. 746 * 2. (If the outgoing interface is detected) the current 747 * hop limit of the interface specified by router advertisement. 748 * 3. The system default hoplimit. 749 */ 750 int 751 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 752 { 753 754 if (in6p && in6p->in6p_hops >= 0) 755 return (in6p->in6p_hops); 756 else if (ifp) 757 return (ND_IFINFO(ifp)->chlim); 758 else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) { 759 struct route_in6 ro6; 760 struct ifnet *lifp; 761 762 bzero(&ro6, sizeof(ro6)); 763 ro6.ro_dst.sin6_family = AF_INET6; 764 ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 765 ro6.ro_dst.sin6_addr = in6p->in6p_faddr; 766 rtalloc((struct route *)&ro6); 767 if (ro6.ro_rt) { 768 lifp = ro6.ro_rt->rt_ifp; 769 RTFREE(ro6.ro_rt); 770 if (lifp) 771 return (ND_IFINFO(lifp)->chlim); 772 } else 773 return (ip6_defhlim); 774 } 775 return (ip6_defhlim); 776 } 777 778 /* 779 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 780 * share this function by all *bsd*... 781 */ 782 int 783 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred) 784 { 785 struct socket *so = inp->inp_socket; 786 u_int16_t lport = 0, first, last, *lastport; 787 int count, error, wild = 0, dorandom; 788 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 789 790 INP_INFO_WLOCK_ASSERT(pcbinfo); 791 INP_WLOCK_ASSERT(inp); 792 793 error = prison_local_ip6(cred, laddr, 794 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)); 795 if (error) 796 return(error); 797 798 /* XXX: this is redundant when called from in6_pcbbind */ 799 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 800 wild = INPLOOKUP_WILDCARD; 801 802 inp->inp_flags |= INP_ANONPORT; 803 804 if (inp->inp_flags & INP_HIGHPORT) { 805 first = ipport_hifirstauto; /* sysctl */ 806 last = ipport_hilastauto; 807 lastport = &pcbinfo->ipi_lasthi; 808 } else if (inp->inp_flags & INP_LOWPORT) { 809 error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0); 810 if (error) 811 return error; 812 first = ipport_lowfirstauto; /* 1023 */ 813 last = ipport_lowlastauto; /* 600 */ 814 lastport = &pcbinfo->ipi_lastlow; 815 } else { 816 first = ipport_firstauto; /* sysctl */ 817 last = ipport_lastauto; 818 lastport = &pcbinfo->ipi_lastport; 819 } 820 821 /* 822 * For UDP, use random port allocation as long as the user 823 * allows it. For TCP (and as of yet unknown) connections, 824 * use random port allocation only if the user allows it AND 825 * ipport_tick() allows it. 826 */ 827 if (ipport_randomized && 828 (!ipport_stoprandom || pcbinfo == &udbinfo)) 829 dorandom = 1; 830 else 831 dorandom = 0; 832 /* 833 * It makes no sense to do random port allocation if 834 * we have the only port available. 835 */ 836 if (first == last) 837 dorandom = 0; 838 /* Make sure to not include UDP packets in the count. */ 839 if (pcbinfo != &udbinfo) 840 ipport_tcpallocs++; 841 842 /* 843 * Instead of having two loops further down counting up or down 844 * make sure that first is always <= last and go with only one 845 * code path implementing all logic. 846 */ 847 if (first > last) { 848 u_int16_t aux; 849 850 aux = first; 851 first = last; 852 last = aux; 853 } 854 855 if (dorandom) 856 *lastport = first + (arc4random() % (last - first)); 857 858 count = last - first; 859 860 do { 861 if (count-- < 0) { /* completely used? */ 862 /* Undo an address bind that may have occurred. */ 863 inp->in6p_laddr = in6addr_any; 864 return (EADDRNOTAVAIL); 865 } 866 ++*lastport; 867 if (*lastport < first || *lastport > last) 868 *lastport = first; 869 lport = htons(*lastport); 870 } while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, 871 lport, wild, cred)); 872 873 inp->inp_lport = lport; 874 if (in_pcbinshash(inp) != 0) { 875 inp->in6p_laddr = in6addr_any; 876 inp->inp_lport = 0; 877 return (EAGAIN); 878 } 879 880 return (0); 881 } 882 883 void 884 addrsel_policy_init(void) 885 { 886 ADDRSEL_LOCK_INIT(); 887 ADDRSEL_SXLOCK_INIT(); 888 889 init_policy_queue(); 890 891 /* initialize the "last resort" policy */ 892 bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy)); 893 defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; 894 } 895 896 static struct in6_addrpolicy * 897 lookup_addrsel_policy(struct sockaddr_in6 *key) 898 { 899 struct in6_addrpolicy *match = NULL; 900 901 ADDRSEL_LOCK(); 902 match = match_addrsel_policy(key); 903 904 if (match == NULL) 905 match = &defaultaddrpolicy; 906 else 907 match->use++; 908 ADDRSEL_UNLOCK(); 909 910 return (match); 911 } 912 913 /* 914 * Subroutines to manage the address selection policy table via sysctl. 915 */ 916 struct walkarg { 917 struct sysctl_req *w_req; 918 }; 919 920 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); 921 SYSCTL_DECL(_net_inet6_ip6); 922 SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, 923 CTLFLAG_RD, in6_src_sysctl, ""); 924 925 static int 926 in6_src_sysctl(SYSCTL_HANDLER_ARGS) 927 { 928 struct walkarg w; 929 930 if (req->newptr) 931 return EPERM; 932 933 bzero(&w, sizeof(w)); 934 w.w_req = req; 935 936 return (walk_addrsel_policy(dump_addrsel_policyent, &w)); 937 } 938 939 int 940 in6_src_ioctl(u_long cmd, caddr_t data) 941 { 942 int i; 943 struct in6_addrpolicy ent0; 944 945 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) 946 return (EOPNOTSUPP); /* check for safety */ 947 948 ent0 = *(struct in6_addrpolicy *)data; 949 950 if (ent0.label == ADDR_LABEL_NOTAPP) 951 return (EINVAL); 952 /* check if the prefix mask is consecutive. */ 953 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) 954 return (EINVAL); 955 /* clear trailing garbages (if any) of the prefix address. */ 956 for (i = 0; i < 4; i++) { 957 ent0.addr.sin6_addr.s6_addr32[i] &= 958 ent0.addrmask.sin6_addr.s6_addr32[i]; 959 } 960 ent0.use = 0; 961 962 switch (cmd) { 963 case SIOCAADDRCTL_POLICY: 964 return (add_addrsel_policyent(&ent0)); 965 case SIOCDADDRCTL_POLICY: 966 return (delete_addrsel_policyent(&ent0)); 967 } 968 969 return (0); /* XXX: compromise compilers */ 970 } 971 972 /* 973 * The followings are implementation of the policy table using a 974 * simple tail queue. 975 * XXX such details should be hidden. 976 * XXX implementation using binary tree should be more efficient. 977 */ 978 struct addrsel_policyent { 979 TAILQ_ENTRY(addrsel_policyent) ape_entry; 980 struct in6_addrpolicy ape_policy; 981 }; 982 983 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); 984 985 struct addrsel_policyhead addrsel_policytab; 986 987 static void 988 init_policy_queue(void) 989 { 990 991 TAILQ_INIT(&addrsel_policytab); 992 } 993 994 static int 995 add_addrsel_policyent(struct in6_addrpolicy *newpolicy) 996 { 997 struct addrsel_policyent *new, *pol; 998 999 MALLOC(new, struct addrsel_policyent *, sizeof(*new), M_IFADDR, 1000 M_WAITOK); 1001 ADDRSEL_XLOCK(); 1002 ADDRSEL_LOCK(); 1003 1004 /* duplication check */ 1005 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { 1006 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, 1007 &pol->ape_policy.addr.sin6_addr) && 1008 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, 1009 &pol->ape_policy.addrmask.sin6_addr)) { 1010 ADDRSEL_UNLOCK(); 1011 ADDRSEL_XUNLOCK(); 1012 FREE(new, M_IFADDR); 1013 return (EEXIST); /* or override it? */ 1014 } 1015 } 1016 1017 bzero(new, sizeof(*new)); 1018 1019 /* XXX: should validate entry */ 1020 new->ape_policy = *newpolicy; 1021 1022 TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry); 1023 ADDRSEL_UNLOCK(); 1024 ADDRSEL_XUNLOCK(); 1025 1026 return (0); 1027 } 1028 1029 static int 1030 delete_addrsel_policyent(struct in6_addrpolicy *key) 1031 { 1032 struct addrsel_policyent *pol; 1033 1034 ADDRSEL_XLOCK(); 1035 ADDRSEL_LOCK(); 1036 1037 /* search for the entry in the table */ 1038 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { 1039 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, 1040 &pol->ape_policy.addr.sin6_addr) && 1041 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, 1042 &pol->ape_policy.addrmask.sin6_addr)) { 1043 break; 1044 } 1045 } 1046 if (pol == NULL) { 1047 ADDRSEL_UNLOCK(); 1048 ADDRSEL_XUNLOCK(); 1049 return (ESRCH); 1050 } 1051 1052 TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry); 1053 ADDRSEL_UNLOCK(); 1054 ADDRSEL_XUNLOCK(); 1055 1056 return (0); 1057 } 1058 1059 static int 1060 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), 1061 void *w) 1062 { 1063 struct addrsel_policyent *pol; 1064 int error = 0; 1065 1066 ADDRSEL_SLOCK(); 1067 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) { 1068 if ((error = (*callback)(&pol->ape_policy, w)) != 0) { 1069 ADDRSEL_SUNLOCK(); 1070 return (error); 1071 } 1072 } 1073 ADDRSEL_SUNLOCK(); 1074 return (error); 1075 } 1076 1077 static int 1078 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) 1079 { 1080 int error = 0; 1081 struct walkarg *w = arg; 1082 1083 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); 1084 1085 return (error); 1086 } 1087 1088 static struct in6_addrpolicy * 1089 match_addrsel_policy(struct sockaddr_in6 *key) 1090 { 1091 struct addrsel_policyent *pent; 1092 struct in6_addrpolicy *bestpol = NULL, *pol; 1093 int matchlen, bestmatchlen = -1; 1094 u_char *mp, *ep, *k, *p, m; 1095 1096 TAILQ_FOREACH(pent, &addrsel_policytab, ape_entry) { 1097 matchlen = 0; 1098 1099 pol = &pent->ape_policy; 1100 mp = (u_char *)&pol->addrmask.sin6_addr; 1101 ep = mp + 16; /* XXX: scope field? */ 1102 k = (u_char *)&key->sin6_addr; 1103 p = (u_char *)&pol->addr.sin6_addr; 1104 for (; mp < ep && *mp; mp++, k++, p++) { 1105 m = *mp; 1106 if ((*k & m) != *p) 1107 goto next; /* not match */ 1108 if (m == 0xff) /* short cut for a typical case */ 1109 matchlen += 8; 1110 else { 1111 while (m >= 0x80) { 1112 matchlen++; 1113 m <<= 1; 1114 } 1115 } 1116 } 1117 1118 /* matched. check if this is better than the current best. */ 1119 if (bestpol == NULL || 1120 matchlen > bestmatchlen) { 1121 bestpol = pol; 1122 bestmatchlen = matchlen; 1123 } 1124 1125 next: 1126 continue; 1127 } 1128 1129 return (bestpol); 1130 }
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