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/jail.h> 84 #include <sys/kernel.h> 85 #include <sys/rmlock.h> 86 #include <sys/sx.h> 87 88 #include <net/if.h> 89 #include <net/if_var.h> 90 #include <net/if_dl.h> 91 #include <net/route.h> 92 #include <net/if_llatbl.h> 93 #ifdef RADIX_MPATH 94 #include <net/radix_mpath.h> 95 #endif 96 97 #include <netinet/in.h> 98 #include <netinet/in_var.h> 99 #include <netinet/in_systm.h> 100 #include <netinet/ip.h> 101 #include <netinet/in_pcb.h> 102 #include <netinet/ip_var.h> 103 #include <netinet/udp.h> 104 #include <netinet/udp_var.h> 105 106 #include <netinet6/in6_var.h> 107 #include <netinet/ip6.h> 108 #include <netinet6/in6_pcb.h> 109 #include <netinet6/ip6_var.h> 110 #include <netinet6/scope6_var.h> 111 #include <netinet6/nd6.h> 112 113 static struct mtx addrsel_lock; 114 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF) 115 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock) 116 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock) 117 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED) 118 119 static struct sx addrsel_sxlock; 120 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock") 121 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock) 122 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock) 123 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock) 124 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock) 125 126 #define ADDR_LABEL_NOTAPP (-1) 127 static VNET_DEFINE(struct in6_addrpolicy, defaultaddrpolicy); 128 #define V_defaultaddrpolicy VNET(defaultaddrpolicy) 129 130 VNET_DEFINE(int, ip6_prefer_tempaddr) = 0; 131 132 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 133 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 134 struct rtentry **, int, u_int); 135 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 136 struct ip6_moptions *, struct route_in6 *ro, struct ifnet **, 137 struct ifnet *, u_int); 138 139 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); 140 141 static void init_policy_queue(void); 142 static int add_addrsel_policyent(struct in6_addrpolicy *); 143 static int delete_addrsel_policyent(struct in6_addrpolicy *); 144 static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *), 145 void *); 146 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); 147 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); 148 149 /* 150 * Return an IPv6 address, which is the most appropriate for a given 151 * destination and user specified options. 152 * If necessary, this function lookups the routing table and returns 153 * an entry to the caller for later use. 154 */ 155 #define REPLACE(r) do {\ 156 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 157 rule = (r); \ 158 /* { \ 159 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 160 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)); \ 161 } */ \ 162 goto replace; \ 163 } while(0) 164 #define NEXT(r) do {\ 165 /* { \ 166 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 167 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)); \ 168 } */ \ 169 goto next; /* XXX: we can't use 'continue' here */ \ 170 } while(0) 171 #define BREAK(r) do { \ 172 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 173 rule = (r); \ 174 goto out; /* XXX: we can't use 'break' here */ \ 175 } while(0) 176 177 int 178 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 179 struct inpcb *inp, struct route_in6 *ro, struct ucred *cred, 180 struct ifnet **ifpp, struct in6_addr *srcp) 181 { 182 struct rm_priotracker in6_ifa_tracker; 183 struct in6_addr dst, tmp; 184 struct ifnet *ifp = NULL, *oifp = NULL; 185 struct in6_ifaddr *ia = NULL, *ia_best = NULL; 186 struct in6_pktinfo *pi = NULL; 187 int dst_scope = -1, best_scope = -1, best_matchlen = -1; 188 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; 189 u_int32_t odstzone; 190 int prefer_tempaddr; 191 int error, rule; 192 struct ip6_moptions *mopts; 193 194 KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__)); 195 196 dst = dstsock->sin6_addr; /* make a copy for local operation */ 197 if (ifpp) { 198 /* 199 * Save a possibly passed in ifp for in6_selectsrc. Only 200 * neighbor discovery code should use this feature, where 201 * we may know the interface but not the FIB number holding 202 * the connected subnet in case someone deleted it from the 203 * default FIB and we need to check the interface. 204 */ 205 if (*ifpp != NULL) 206 oifp = *ifpp; 207 *ifpp = NULL; 208 } 209 210 if (inp != NULL) { 211 INP_LOCK_ASSERT(inp); 212 mopts = inp->in6p_moptions; 213 } else { 214 mopts = NULL; 215 } 216 217 /* 218 * If the source address is explicitly specified by the caller, 219 * check if the requested source address is indeed a unicast address 220 * assigned to the node, and can be used as the packet's source 221 * address. If everything is okay, use the address as source. 222 */ 223 if (opts && (pi = opts->ip6po_pktinfo) && 224 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 225 struct sockaddr_in6 srcsock; 226 struct in6_ifaddr *ia6; 227 228 /* get the outgoing interface */ 229 if ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp, oifp, 230 (inp != NULL) ? inp->inp_inc.inc_fibnum : RT_DEFAULT_FIB)) 231 != 0) 232 return (error); 233 234 /* 235 * determine the appropriate zone id of the source based on 236 * the zone of the destination and the outgoing interface. 237 * If the specified address is ambiguous wrt the scope zone, 238 * the interface must be specified; otherwise, ifa_ifwithaddr() 239 * will fail matching the address. 240 */ 241 bzero(&srcsock, sizeof(srcsock)); 242 srcsock.sin6_family = AF_INET6; 243 srcsock.sin6_len = sizeof(srcsock); 244 srcsock.sin6_addr = pi->ipi6_addr; 245 if (ifp) { 246 error = in6_setscope(&srcsock.sin6_addr, ifp, NULL); 247 if (error) 248 return (error); 249 } 250 if (cred != NULL && (error = prison_local_ip6(cred, 251 &srcsock.sin6_addr, (inp != NULL && 252 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 253 return (error); 254 255 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr( 256 (struct sockaddr *)&srcsock); 257 if (ia6 == NULL || 258 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) { 259 if (ia6 != NULL) 260 ifa_free(&ia6->ia_ifa); 261 return (EADDRNOTAVAIL); 262 } 263 pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ 264 if (ifpp) 265 *ifpp = ifp; 266 bcopy(&ia6->ia_addr.sin6_addr, srcp, sizeof(*srcp)); 267 ifa_free(&ia6->ia_ifa); 268 return (0); 269 } 270 271 /* 272 * Otherwise, if the socket has already bound the source, just use it. 273 */ 274 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { 275 if (cred != NULL && 276 (error = prison_local_ip6(cred, &inp->in6p_laddr, 277 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 278 return (error); 279 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp)); 280 return (0); 281 } 282 283 /* 284 * Bypass source address selection and use the primary jail IP 285 * if requested. 286 */ 287 if (cred != NULL && !prison_saddrsel_ip6(cred, srcp)) 288 return (0); 289 290 /* 291 * If the address is not specified, choose the best one based on 292 * the outgoing interface and the destination address. 293 */ 294 /* get the outgoing interface */ 295 if ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp, oifp, 296 (inp != NULL) ? inp->inp_inc.inc_fibnum : RT_DEFAULT_FIB)) != 0) 297 return (error); 298 299 #ifdef DIAGNOSTIC 300 if (ifp == NULL) /* this should not happen */ 301 panic("in6_selectsrc: NULL ifp"); 302 #endif 303 error = in6_setscope(&dst, ifp, &odstzone); 304 if (error) 305 return (error); 306 307 rule = 0; 308 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 309 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 310 int new_scope = -1, new_matchlen = -1; 311 struct in6_addrpolicy *new_policy = NULL; 312 u_int32_t srczone, osrczone, dstzone; 313 struct in6_addr src; 314 struct ifnet *ifp1 = ia->ia_ifp; 315 316 /* 317 * We'll never take an address that breaks the scope zone 318 * of the destination. We also skip an address if its zone 319 * does not contain the outgoing interface. 320 * XXX: we should probably use sin6_scope_id here. 321 */ 322 if (in6_setscope(&dst, ifp1, &dstzone) || 323 odstzone != dstzone) { 324 continue; 325 } 326 src = ia->ia_addr.sin6_addr; 327 if (in6_setscope(&src, ifp, &osrczone) || 328 in6_setscope(&src, ifp1, &srczone) || 329 osrczone != srczone) { 330 continue; 331 } 332 333 /* avoid unusable addresses */ 334 if ((ia->ia6_flags & 335 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { 336 continue; 337 } 338 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) 339 continue; 340 341 /* If jailed only take addresses of the jail into account. */ 342 if (cred != NULL && 343 prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0) 344 continue; 345 346 /* Rule 1: Prefer same address */ 347 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { 348 ia_best = ia; 349 BREAK(1); /* there should be no better candidate */ 350 } 351 352 if (ia_best == NULL) 353 REPLACE(0); 354 355 /* Rule 2: Prefer appropriate scope */ 356 if (dst_scope < 0) 357 dst_scope = in6_addrscope(&dst); 358 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); 359 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { 360 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) 361 REPLACE(2); 362 NEXT(2); 363 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { 364 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) 365 NEXT(2); 366 REPLACE(2); 367 } 368 369 /* 370 * Rule 3: Avoid deprecated addresses. Note that the case of 371 * !ip6_use_deprecated is already rejected above. 372 */ 373 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) 374 NEXT(3); 375 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) 376 REPLACE(3); 377 378 /* Rule 4: Prefer home addresses */ 379 /* 380 * XXX: This is a TODO. We should probably merge the MIP6 381 * case above. 382 */ 383 384 /* Rule 5: Prefer outgoing interface */ 385 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) { 386 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) 387 NEXT(5); 388 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) 389 REPLACE(5); 390 } 391 392 /* 393 * Rule 6: Prefer matching label 394 * Note that best_policy should be non-NULL here. 395 */ 396 if (dst_policy == NULL) 397 dst_policy = lookup_addrsel_policy(dstsock); 398 if (dst_policy->label != ADDR_LABEL_NOTAPP) { 399 new_policy = lookup_addrsel_policy(&ia->ia_addr); 400 if (dst_policy->label == best_policy->label && 401 dst_policy->label != new_policy->label) 402 NEXT(6); 403 if (dst_policy->label != best_policy->label && 404 dst_policy->label == new_policy->label) 405 REPLACE(6); 406 } 407 408 /* 409 * Rule 7: Prefer public addresses. 410 * We allow users to reverse the logic by configuring 411 * a sysctl variable, so that privacy conscious users can 412 * always prefer temporary addresses. 413 */ 414 if (opts == NULL || 415 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { 416 prefer_tempaddr = V_ip6_prefer_tempaddr; 417 } else if (opts->ip6po_prefer_tempaddr == 418 IP6PO_TEMPADDR_NOTPREFER) { 419 prefer_tempaddr = 0; 420 } else 421 prefer_tempaddr = 1; 422 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 423 (ia->ia6_flags & IN6_IFF_TEMPORARY)) { 424 if (prefer_tempaddr) 425 REPLACE(7); 426 else 427 NEXT(7); 428 } 429 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 430 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 431 if (prefer_tempaddr) 432 NEXT(7); 433 else 434 REPLACE(7); 435 } 436 437 /* 438 * Rule 8: prefer addresses on alive interfaces. 439 * This is a KAME specific rule. 440 */ 441 if ((ia_best->ia_ifp->if_flags & IFF_UP) && 442 !(ia->ia_ifp->if_flags & IFF_UP)) 443 NEXT(8); 444 if (!(ia_best->ia_ifp->if_flags & IFF_UP) && 445 (ia->ia_ifp->if_flags & IFF_UP)) 446 REPLACE(8); 447 448 /* 449 * Rule 9: prefer address with better virtual status. 450 */ 451 if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa)) 452 REPLACE(9); 453 if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa)) 454 NEXT(9); 455 456 /* 457 * Rule 10: prefer address with `prefer_source' flag. 458 */ 459 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 && 460 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0) 461 REPLACE(10); 462 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 && 463 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0) 464 NEXT(10); 465 466 /* 467 * Rule 14: Use longest matching prefix. 468 * Note: in the address selection draft, this rule is 469 * documented as "Rule 8". However, since it is also 470 * documented that this rule can be overridden, we assign 471 * a large number so that it is easy to assign smaller numbers 472 * to more preferred rules. 473 */ 474 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); 475 if (best_matchlen < new_matchlen) 476 REPLACE(14); 477 if (new_matchlen < best_matchlen) 478 NEXT(14); 479 480 /* Rule 15 is reserved. */ 481 482 /* 483 * Last resort: just keep the current candidate. 484 * Or, do we need more rules? 485 */ 486 continue; 487 488 replace: 489 ia_best = ia; 490 best_scope = (new_scope >= 0 ? new_scope : 491 in6_addrscope(&ia_best->ia_addr.sin6_addr)); 492 best_policy = (new_policy ? new_policy : 493 lookup_addrsel_policy(&ia_best->ia_addr)); 494 best_matchlen = (new_matchlen >= 0 ? new_matchlen : 495 in6_matchlen(&ia_best->ia_addr.sin6_addr, 496 &dst)); 497 498 next: 499 continue; 500 501 out: 502 break; 503 } 504 505 if ((ia = ia_best) == NULL) { 506 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 507 IP6STAT_INC(ip6s_sources_none); 508 return (EADDRNOTAVAIL); 509 } 510 511 /* 512 * At this point at least one of the addresses belonged to the jail 513 * but it could still be, that we want to further restrict it, e.g. 514 * theoratically IN6_IS_ADDR_LOOPBACK. 515 * It must not be IN6_IS_ADDR_UNSPECIFIED anymore. 516 * prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should 517 * let all others previously selected pass. 518 * Use tmp to not change ::1 on lo0 to the primary jail address. 519 */ 520 tmp = ia->ia_addr.sin6_addr; 521 if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL && 522 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) { 523 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 524 IP6STAT_INC(ip6s_sources_none); 525 return (EADDRNOTAVAIL); 526 } 527 528 if (ifpp) 529 *ifpp = ifp; 530 531 bcopy(&tmp, srcp, sizeof(*srcp)); 532 if (ia->ia_ifp == ifp) 533 IP6STAT_INC(ip6s_sources_sameif[best_scope]); 534 else 535 IP6STAT_INC(ip6s_sources_otherif[best_scope]); 536 if (dst_scope == best_scope) 537 IP6STAT_INC(ip6s_sources_samescope[best_scope]); 538 else 539 IP6STAT_INC(ip6s_sources_otherscope[best_scope]); 540 if (IFA6_IS_DEPRECATED(ia)) 541 IP6STAT_INC(ip6s_sources_deprecated[best_scope]); 542 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 543 return (0); 544 } 545 546 /* 547 * clone - meaningful only for bsdi and freebsd 548 */ 549 static int 550 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 551 struct ip6_moptions *mopts, struct route_in6 *ro, 552 struct ifnet **retifp, struct rtentry **retrt, int norouteok, u_int fibnum) 553 { 554 int error = 0; 555 struct ifnet *ifp = NULL; 556 struct rtentry *rt = NULL; 557 struct sockaddr_in6 *sin6_next; 558 struct in6_pktinfo *pi = NULL; 559 struct in6_addr *dst = &dstsock->sin6_addr; 560 uint32_t zoneid; 561 #if 0 562 char ip6buf[INET6_ADDRSTRLEN]; 563 564 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 565 dstsock->sin6_addr.s6_addr32[1] == 0 && 566 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 567 printf("in6_selectroute: strange destination %s\n", 568 ip6_sprintf(ip6buf, &dstsock->sin6_addr)); 569 } else { 570 printf("in6_selectroute: destination = %s%%%d\n", 571 ip6_sprintf(ip6buf, &dstsock->sin6_addr), 572 dstsock->sin6_scope_id); /* for debug */ 573 } 574 #endif 575 576 /* If the caller specify the outgoing interface explicitly, use it. */ 577 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 578 /* XXX boundary check is assumed to be already done. */ 579 ifp = ifnet_byindex(pi->ipi6_ifindex); 580 if (ifp != NULL && 581 (norouteok || retrt == NULL || 582 IN6_IS_ADDR_MULTICAST(dst))) { 583 /* 584 * we do not have to check or get the route for 585 * multicast. 586 */ 587 goto done; 588 } else 589 goto getroute; 590 } 591 /* 592 * If the destination address is a multicast address and the outgoing 593 * interface for the address is specified by the caller, use it. 594 */ 595 if (IN6_IS_ADDR_MULTICAST(dst) && 596 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 597 goto done; /* we do not need a route for multicast. */ 598 } 599 /* 600 * If destination address is LLA or link- or node-local multicast, 601 * use it's embedded scope zone id to determine outgoing interface. 602 */ 603 if (IN6_IS_ADDR_MC_LINKLOCAL(dst) || 604 IN6_IS_ADDR_MC_NODELOCAL(dst)) { 605 zoneid = ntohs(in6_getscope(dst)); 606 if (zoneid > 0) { 607 ifp = in6_getlinkifnet(zoneid); 608 goto done; 609 } 610 } 611 612 getroute: 613 /* 614 * If the next hop address for the packet is specified by the caller, 615 * use it as the gateway. 616 */ 617 if (opts && opts->ip6po_nexthop) { 618 struct route_in6 *ron; 619 620 sin6_next = satosin6(opts->ip6po_nexthop); 621 if (IN6_IS_ADDR_LINKLOCAL(&sin6_next->sin6_addr)) { 622 /* 623 * Next hop is LLA, thus it should be neighbor. 624 * Determine outgoing interface by zone index. 625 */ 626 zoneid = ntohs(in6_getscope(&sin6_next->sin6_addr)); 627 if (zoneid > 0) { 628 ifp = in6_getlinkifnet(zoneid); 629 goto done; 630 } 631 } 632 ron = &opts->ip6po_nextroute; 633 /* Use a cached route if it exists and is valid. */ 634 if (ron->ro_rt != NULL && ( 635 (ron->ro_rt->rt_flags & RTF_UP) == 0 || 636 ron->ro_dst.sin6_family != AF_INET6 || 637 !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr, 638 &sin6_next->sin6_addr))) 639 RO_RTFREE(ron); 640 if (ron->ro_rt == NULL) { 641 ron->ro_dst = *sin6_next; 642 in6_rtalloc(ron, fibnum); /* multi path case? */ 643 } 644 /* 645 * The node identified by that address must be a 646 * neighbor of the sending host. 647 */ 648 if (ron->ro_rt == NULL || 649 (ron->ro_rt->rt_flags & RTF_GATEWAY) != 0) 650 error = EHOSTUNREACH; 651 goto done; 652 } 653 654 /* 655 * Use a cached route if it exists and is valid, else try to allocate 656 * a new one. Note that we should check the address family of the 657 * cached destination, in case of sharing the cache with IPv4. 658 */ 659 if (ro) { 660 if (ro->ro_rt && 661 (!(ro->ro_rt->rt_flags & RTF_UP) || 662 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 663 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 664 dst))) { 665 RTFREE(ro->ro_rt); 666 ro->ro_rt = (struct rtentry *)NULL; 667 } 668 if (ro->ro_rt == (struct rtentry *)NULL) { 669 struct sockaddr_in6 *sa6; 670 671 /* No route yet, so try to acquire one */ 672 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 673 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 674 *sa6 = *dstsock; 675 sa6->sin6_scope_id = 0; 676 677 #ifdef RADIX_MPATH 678 rtalloc_mpath_fib((struct route *)ro, 679 ntohl(sa6->sin6_addr.s6_addr32[3]), fibnum); 680 #else 681 ro->ro_rt = in6_rtalloc1((struct sockaddr *) 682 &ro->ro_dst, 0, 0UL, fibnum); 683 if (ro->ro_rt) 684 RT_UNLOCK(ro->ro_rt); 685 #endif 686 } 687 688 /* 689 * do not care about the result if we have the nexthop 690 * explicitly specified. 691 */ 692 if (opts && opts->ip6po_nexthop) 693 goto done; 694 695 if (ro->ro_rt) { 696 ifp = ro->ro_rt->rt_ifp; 697 698 if (ifp == NULL) { /* can this really happen? */ 699 RTFREE(ro->ro_rt); 700 ro->ro_rt = NULL; 701 } 702 } 703 if (ro->ro_rt == NULL) 704 error = EHOSTUNREACH; 705 rt = ro->ro_rt; 706 707 /* 708 * Check if the outgoing interface conflicts with 709 * the interface specified by ipi6_ifindex (if specified). 710 * Note that loopback interface is always okay. 711 * (this may happen when we are sending a packet to one of 712 * our own addresses.) 713 */ 714 if (ifp && opts && opts->ip6po_pktinfo && 715 opts->ip6po_pktinfo->ipi6_ifindex) { 716 if (!(ifp->if_flags & IFF_LOOPBACK) && 717 ifp->if_index != 718 opts->ip6po_pktinfo->ipi6_ifindex) { 719 error = EHOSTUNREACH; 720 goto done; 721 } 722 } 723 } 724 725 done: 726 if (ifp == NULL && rt == NULL) { 727 /* 728 * This can happen if the caller did not pass a cached route 729 * nor any other hints. We treat this case an error. 730 */ 731 error = EHOSTUNREACH; 732 } 733 if (error == EHOSTUNREACH) 734 IP6STAT_INC(ip6s_noroute); 735 736 if (retifp != NULL) { 737 *retifp = ifp; 738 739 /* 740 * Adjust the "outgoing" interface. If we're going to loop 741 * the packet back to ourselves, the ifp would be the loopback 742 * interface. However, we'd rather know the interface associated 743 * to the destination address (which should probably be one of 744 * our own addresses.) 745 */ 746 if (rt) { 747 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) && 748 (rt->rt_gateway->sa_family == AF_LINK)) 749 *retifp = 750 ifnet_byindex(((struct sockaddr_dl *) 751 rt->rt_gateway)->sdl_index); 752 } 753 } 754 755 if (retrt != NULL) 756 *retrt = rt; /* rt may be NULL */ 757 758 return (error); 759 } 760 761 static int 762 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 763 struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp, 764 struct ifnet *oifp, u_int fibnum) 765 { 766 int error; 767 struct route_in6 sro; 768 struct rtentry *rt = NULL; 769 770 KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__)); 771 772 if (ro == NULL) { 773 bzero(&sro, sizeof(sro)); 774 ro = &sro; 775 } 776 777 if ((error = selectroute(dstsock, opts, mopts, ro, retifp, 778 &rt, 1, fibnum)) != 0) { 779 if (ro == &sro && rt && rt == sro.ro_rt) 780 RTFREE(rt); 781 /* Help ND. See oifp comment in in6_selectsrc(). */ 782 if (oifp != NULL && fibnum == RT_DEFAULT_FIB) { 783 *retifp = oifp; 784 error = 0; 785 } 786 return (error); 787 } 788 789 /* 790 * do not use a rejected or black hole route. 791 * XXX: this check should be done in the L2 output routine. 792 * However, if we skipped this check here, we'd see the following 793 * scenario: 794 * - install a rejected route for a scoped address prefix 795 * (like fe80::/10) 796 * - send a packet to a destination that matches the scoped prefix, 797 * with ambiguity about the scope zone. 798 * - pick the outgoing interface from the route, and disambiguate the 799 * scope zone with the interface. 800 * - ip6_output() would try to get another route with the "new" 801 * destination, which may be valid. 802 * - we'd see no error on output. 803 * Although this may not be very harmful, it should still be confusing. 804 * We thus reject the case here. 805 */ 806 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) { 807 int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 808 809 if (ro == &sro && rt && rt == sro.ro_rt) 810 RTFREE(rt); 811 return (flags); 812 } 813 814 if (ro == &sro && rt && rt == sro.ro_rt) 815 RTFREE(rt); 816 return (0); 817 } 818 819 /* 820 * Public wrapper function to selectroute(). 821 * 822 * XXX-BZ in6_selectroute() should and will grow the FIB argument. The 823 * in6_selectroute_fib() function is only there for backward compat on stable. 824 */ 825 int 826 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 827 struct ip6_moptions *mopts, struct route_in6 *ro, 828 struct ifnet **retifp, struct rtentry **retrt) 829 { 830 831 return (selectroute(dstsock, opts, mopts, ro, retifp, 832 retrt, 0, RT_DEFAULT_FIB)); 833 } 834 835 #ifndef BURN_BRIDGES 836 int 837 in6_selectroute_fib(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 838 struct ip6_moptions *mopts, struct route_in6 *ro, 839 struct ifnet **retifp, struct rtentry **retrt, u_int fibnum) 840 { 841 842 return (selectroute(dstsock, opts, mopts, ro, retifp, 843 retrt, 0, fibnum)); 844 } 845 #endif 846 847 /* 848 * Default hop limit selection. The precedence is as follows: 849 * 1. Hoplimit value specified via ioctl. 850 * 2. (If the outgoing interface is detected) the current 851 * hop limit of the interface specified by router advertisement. 852 * 3. The system default hoplimit. 853 */ 854 int 855 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 856 { 857 858 if (in6p && in6p->in6p_hops >= 0) 859 return (in6p->in6p_hops); 860 else if (ifp) 861 return (ND_IFINFO(ifp)->chlim); 862 else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) { 863 struct route_in6 ro6; 864 struct ifnet *lifp; 865 866 bzero(&ro6, sizeof(ro6)); 867 ro6.ro_dst.sin6_family = AF_INET6; 868 ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 869 ro6.ro_dst.sin6_addr = in6p->in6p_faddr; 870 in6_rtalloc(&ro6, in6p->inp_inc.inc_fibnum); 871 if (ro6.ro_rt) { 872 lifp = ro6.ro_rt->rt_ifp; 873 RTFREE(ro6.ro_rt); 874 if (lifp) 875 return (ND_IFINFO(lifp)->chlim); 876 } 877 } 878 return (V_ip6_defhlim); 879 } 880 881 /* 882 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 883 * share this function by all *bsd*... 884 */ 885 int 886 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred) 887 { 888 struct socket *so = inp->inp_socket; 889 u_int16_t lport = 0; 890 int error, lookupflags = 0; 891 #ifdef INVARIANTS 892 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 893 #endif 894 895 INP_WLOCK_ASSERT(inp); 896 INP_HASH_WLOCK_ASSERT(pcbinfo); 897 898 error = prison_local_ip6(cred, laddr, 899 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)); 900 if (error) 901 return(error); 902 903 /* XXX: this is redundant when called from in6_pcbbind */ 904 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 905 lookupflags = INPLOOKUP_WILDCARD; 906 907 inp->inp_flags |= INP_ANONPORT; 908 909 error = in_pcb_lport(inp, NULL, &lport, cred, lookupflags); 910 if (error != 0) 911 return (error); 912 913 inp->inp_lport = lport; 914 if (in_pcbinshash(inp) != 0) { 915 inp->in6p_laddr = in6addr_any; 916 inp->inp_lport = 0; 917 return (EAGAIN); 918 } 919 920 return (0); 921 } 922 923 void 924 addrsel_policy_init(void) 925 { 926 927 init_policy_queue(); 928 929 /* initialize the "last resort" policy */ 930 bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy)); 931 V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; 932 933 if (!IS_DEFAULT_VNET(curvnet)) 934 return; 935 936 ADDRSEL_LOCK_INIT(); 937 ADDRSEL_SXLOCK_INIT(); 938 } 939 940 static struct in6_addrpolicy * 941 lookup_addrsel_policy(struct sockaddr_in6 *key) 942 { 943 struct in6_addrpolicy *match = NULL; 944 945 ADDRSEL_LOCK(); 946 match = match_addrsel_policy(key); 947 948 if (match == NULL) 949 match = &V_defaultaddrpolicy; 950 else 951 match->use++; 952 ADDRSEL_UNLOCK(); 953 954 return (match); 955 } 956 957 /* 958 * Subroutines to manage the address selection policy table via sysctl. 959 */ 960 struct walkarg { 961 struct sysctl_req *w_req; 962 }; 963 964 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); 965 SYSCTL_DECL(_net_inet6_ip6); 966 static SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, 967 CTLFLAG_RD, in6_src_sysctl, ""); 968 969 static int 970 in6_src_sysctl(SYSCTL_HANDLER_ARGS) 971 { 972 struct walkarg w; 973 974 if (req->newptr) 975 return EPERM; 976 977 bzero(&w, sizeof(w)); 978 w.w_req = req; 979 980 return (walk_addrsel_policy(dump_addrsel_policyent, &w)); 981 } 982 983 int 984 in6_src_ioctl(u_long cmd, caddr_t data) 985 { 986 struct in6_addrpolicy ent0; 987 988 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) 989 return (EOPNOTSUPP); /* check for safety */ 990 991 ent0 = *(struct in6_addrpolicy *)data; 992 993 if (ent0.label == ADDR_LABEL_NOTAPP) 994 return (EINVAL); 995 /* check if the prefix mask is consecutive. */ 996 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) 997 return (EINVAL); 998 /* clear trailing garbages (if any) of the prefix address. */ 999 IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr); 1000 ent0.use = 0; 1001 1002 switch (cmd) { 1003 case SIOCAADDRCTL_POLICY: 1004 return (add_addrsel_policyent(&ent0)); 1005 case SIOCDADDRCTL_POLICY: 1006 return (delete_addrsel_policyent(&ent0)); 1007 } 1008 1009 return (0); /* XXX: compromise compilers */ 1010 } 1011 1012 /* 1013 * The followings are implementation of the policy table using a 1014 * simple tail queue. 1015 * XXX such details should be hidden. 1016 * XXX implementation using binary tree should be more efficient. 1017 */ 1018 struct addrsel_policyent { 1019 TAILQ_ENTRY(addrsel_policyent) ape_entry; 1020 struct in6_addrpolicy ape_policy; 1021 }; 1022 1023 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); 1024 1025 static VNET_DEFINE(struct addrsel_policyhead, addrsel_policytab); 1026 #define V_addrsel_policytab VNET(addrsel_policytab) 1027 1028 static void 1029 init_policy_queue(void) 1030 { 1031 1032 TAILQ_INIT(&V_addrsel_policytab); 1033 } 1034 1035 static int 1036 add_addrsel_policyent(struct in6_addrpolicy *newpolicy) 1037 { 1038 struct addrsel_policyent *new, *pol; 1039 1040 new = malloc(sizeof(*new), M_IFADDR, 1041 M_WAITOK); 1042 ADDRSEL_XLOCK(); 1043 ADDRSEL_LOCK(); 1044 1045 /* duplication check */ 1046 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1047 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, 1048 &pol->ape_policy.addr.sin6_addr) && 1049 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, 1050 &pol->ape_policy.addrmask.sin6_addr)) { 1051 ADDRSEL_UNLOCK(); 1052 ADDRSEL_XUNLOCK(); 1053 free(new, M_IFADDR); 1054 return (EEXIST); /* or override it? */ 1055 } 1056 } 1057 1058 bzero(new, sizeof(*new)); 1059 1060 /* XXX: should validate entry */ 1061 new->ape_policy = *newpolicy; 1062 1063 TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry); 1064 ADDRSEL_UNLOCK(); 1065 ADDRSEL_XUNLOCK(); 1066 1067 return (0); 1068 } 1069 1070 static int 1071 delete_addrsel_policyent(struct in6_addrpolicy *key) 1072 { 1073 struct addrsel_policyent *pol; 1074 1075 ADDRSEL_XLOCK(); 1076 ADDRSEL_LOCK(); 1077 1078 /* search for the entry in the table */ 1079 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1080 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, 1081 &pol->ape_policy.addr.sin6_addr) && 1082 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, 1083 &pol->ape_policy.addrmask.sin6_addr)) { 1084 break; 1085 } 1086 } 1087 if (pol == NULL) { 1088 ADDRSEL_UNLOCK(); 1089 ADDRSEL_XUNLOCK(); 1090 return (ESRCH); 1091 } 1092 1093 TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry); 1094 ADDRSEL_UNLOCK(); 1095 ADDRSEL_XUNLOCK(); 1096 free(pol, M_IFADDR); 1097 1098 return (0); 1099 } 1100 1101 static int 1102 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w) 1103 { 1104 struct addrsel_policyent *pol; 1105 int error = 0; 1106 1107 ADDRSEL_SLOCK(); 1108 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1109 if ((error = (*callback)(&pol->ape_policy, w)) != 0) { 1110 ADDRSEL_SUNLOCK(); 1111 return (error); 1112 } 1113 } 1114 ADDRSEL_SUNLOCK(); 1115 return (error); 1116 } 1117 1118 static int 1119 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) 1120 { 1121 int error = 0; 1122 struct walkarg *w = arg; 1123 1124 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); 1125 1126 return (error); 1127 } 1128 1129 static struct in6_addrpolicy * 1130 match_addrsel_policy(struct sockaddr_in6 *key) 1131 { 1132 struct addrsel_policyent *pent; 1133 struct in6_addrpolicy *bestpol = NULL, *pol; 1134 int matchlen, bestmatchlen = -1; 1135 u_char *mp, *ep, *k, *p, m; 1136 1137 TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) { 1138 matchlen = 0; 1139 1140 pol = &pent->ape_policy; 1141 mp = (u_char *)&pol->addrmask.sin6_addr; 1142 ep = mp + 16; /* XXX: scope field? */ 1143 k = (u_char *)&key->sin6_addr; 1144 p = (u_char *)&pol->addr.sin6_addr; 1145 for (; mp < ep && *mp; mp++, k++, p++) { 1146 m = *mp; 1147 if ((*k & m) != *p) 1148 goto next; /* not match */ 1149 if (m == 0xff) /* short cut for a typical case */ 1150 matchlen += 8; 1151 else { 1152 while (m >= 0x80) { 1153 matchlen++; 1154 m <<= 1; 1155 } 1156 } 1157 } 1158 1159 /* matched. check if this is better than the current best. */ 1160 if (bestpol == NULL || 1161 matchlen > bestmatchlen) { 1162 bestpol = pol; 1163 bestmatchlen = matchlen; 1164 } 1165 1166 next: 1167 continue; 1168 } 1169 1170 return (bestpol); 1171 } 1172