1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $ 32 */ 33 34 /*- 35 * Copyright (c) 1982, 1986, 1991, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. Neither the name of the University nor the names of its contributors 47 * may be used to endorse or promote products derived from this software 48 * without specific prior written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 * 62 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 67 68 #include "opt_inet.h" 69 #include "opt_inet6.h" 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/route/nhop.h> 93 #include <net/if_llatbl.h> 94 95 #include <netinet/in.h> 96 #include <netinet/in_var.h> 97 #include <netinet/in_systm.h> 98 #include <netinet/ip.h> 99 #include <netinet/in_pcb.h> 100 #include <netinet/ip_var.h> 101 #include <netinet/udp.h> 102 #include <netinet/udp_var.h> 103 104 #include <netinet6/in6_var.h> 105 #include <netinet/ip6.h> 106 #include <netinet6/in6_fib.h> 107 #include <netinet6/in6_pcb.h> 108 #include <netinet6/ip6_var.h> 109 #include <netinet6/scope6_var.h> 110 #include <netinet6/nd6.h> 111 112 static struct mtx addrsel_lock; 113 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF) 114 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock) 115 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock) 116 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED) 117 118 static struct sx addrsel_sxlock; 119 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock") 120 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock) 121 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock) 122 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock) 123 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock) 124 125 #define ADDR_LABEL_NOTAPP (-1) 126 VNET_DEFINE_STATIC(struct in6_addrpolicy, defaultaddrpolicy); 127 #define V_defaultaddrpolicy VNET(defaultaddrpolicy) 128 129 VNET_DEFINE(int, ip6_prefer_tempaddr) = 0; 130 131 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 132 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 133 struct nhop_object **, int, u_int, uint32_t); 134 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 135 struct ip6_moptions *, struct ifnet **, 136 struct ifnet *, u_int); 137 static int in6_selectsrc(uint32_t, struct sockaddr_in6 *, 138 struct ip6_pktopts *, struct inpcb *, struct ucred *, 139 struct ifnet **, struct in6_addr *); 140 141 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); 142 143 static void init_policy_queue(void); 144 static int add_addrsel_policyent(struct in6_addrpolicy *); 145 static int delete_addrsel_policyent(struct in6_addrpolicy *); 146 static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *), 147 void *); 148 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); 149 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); 150 151 /* 152 * Return an IPv6 address, which is the most appropriate for a given 153 * destination and user specified options. 154 * If necessary, this function lookups the routing table and returns 155 * an entry to the caller for later use. 156 */ 157 #define REPLACE(r) do {\ 158 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 159 /* { \ 160 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 161 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)); \ 162 } */ \ 163 goto replace; \ 164 } while(0) 165 #define NEXT(r) do {\ 166 /* { \ 167 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 168 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)); \ 169 } */ \ 170 goto next; /* XXX: we can't use 'continue' here */ \ 171 } while(0) 172 #define BREAK(r) do { \ 173 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 174 goto out; /* XXX: we can't use 'break' here */ \ 175 } while(0) 176 177 static int 178 in6_selectsrc(uint32_t fibnum, struct sockaddr_in6 *dstsock, 179 struct ip6_pktopts *opts, struct inpcb *inp, 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; 192 struct ip6_moptions *mopts; 193 194 NET_EPOCH_ASSERT(); 195 KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__)); 196 197 dst = dstsock->sin6_addr; /* make a copy for local operation */ 198 if (ifpp) { 199 /* 200 * Save a possibly passed in ifp for in6_selectsrc. Only 201 * neighbor discovery code should use this feature, where 202 * we may know the interface but not the FIB number holding 203 * the connected subnet in case someone deleted it from the 204 * default FIB and we need to check the interface. 205 */ 206 if (*ifpp != NULL) 207 oifp = *ifpp; 208 *ifpp = NULL; 209 } 210 211 if (inp != NULL) { 212 INP_LOCK_ASSERT(inp); 213 mopts = inp->in6p_moptions; 214 } else { 215 mopts = NULL; 216 } 217 218 /* 219 * If the source address is explicitly specified by the caller, 220 * check if the requested source address is indeed a unicast address 221 * assigned to the node, and can be used as the packet's source 222 * address. If everything is okay, use the address as source. 223 */ 224 if (opts && (pi = opts->ip6po_pktinfo) && 225 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 226 /* get the outgoing interface */ 227 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp, 228 fibnum)) 229 != 0) 230 return (error); 231 232 /* 233 * determine the appropriate zone id of the source based on 234 * the zone of the destination and the outgoing interface. 235 * If the specified address is ambiguous wrt the scope zone, 236 * the interface must be specified; otherwise, ifa_ifwithaddr() 237 * will fail matching the address. 238 */ 239 tmp = pi->ipi6_addr; 240 if (ifp) { 241 error = in6_setscope(&tmp, ifp, &odstzone); 242 if (error) 243 return (error); 244 } 245 if (cred != NULL && (error = prison_local_ip6(cred, 246 &tmp, (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) 247 return (error); 248 249 /* 250 * If IPV6_BINDANY socket option is set, we allow to specify 251 * non local addresses as source address in IPV6_PKTINFO 252 * ancillary data. 253 */ 254 if ((inp->inp_flags & INP_BINDANY) == 0) { 255 ia = in6ifa_ifwithaddr(&tmp, 0 /* XXX */, false); 256 if (ia == NULL || (ia->ia6_flags & (IN6_IFF_ANYCAST | 257 IN6_IFF_NOTREADY))) 258 return (EADDRNOTAVAIL); 259 bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp)); 260 } else 261 bcopy(&tmp, srcp, sizeof(*srcp)); 262 pi->ipi6_addr = tmp; /* XXX: this overrides pi */ 263 if (ifpp) 264 *ifpp = ifp; 265 return (0); 266 } 267 268 /* 269 * Otherwise, if the socket has already bound the source, just use it. 270 */ 271 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { 272 if (cred != NULL && 273 (error = prison_local_ip6(cred, &inp->in6p_laddr, 274 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 275 return (error); 276 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp)); 277 return (0); 278 } 279 280 /* 281 * Bypass source address selection and use the primary jail IP 282 * if requested. 283 */ 284 if (cred != NULL && !prison_saddrsel_ip6(cred, srcp)) 285 return (0); 286 287 /* 288 * If the address is not specified, choose the best one based on 289 * the outgoing interface and the destination address. 290 */ 291 /* get the outgoing interface */ 292 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp, 293 (inp != NULL) ? inp->inp_inc.inc_fibnum : fibnum)) != 0) 294 return (error); 295 296 #ifdef DIAGNOSTIC 297 if (ifp == NULL) /* this should not happen */ 298 panic("in6_selectsrc: NULL ifp"); 299 #endif 300 error = in6_setscope(&dst, ifp, &odstzone); 301 if (error) 302 return (error); 303 304 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 305 CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 306 int new_scope = -1, new_matchlen = -1; 307 struct in6_addrpolicy *new_policy = NULL; 308 u_int32_t srczone, osrczone, dstzone; 309 struct in6_addr src; 310 struct ifnet *ifp1 = ia->ia_ifp; 311 312 /* 313 * We'll never take an address that breaks the scope zone 314 * of the destination. We also skip an address if its zone 315 * does not contain the outgoing interface. 316 * XXX: we should probably use sin6_scope_id here. 317 */ 318 if (in6_setscope(&dst, ifp1, &dstzone) || 319 odstzone != dstzone) { 320 continue; 321 } 322 src = ia->ia_addr.sin6_addr; 323 if (in6_setscope(&src, ifp, &osrczone) || 324 in6_setscope(&src, ifp1, &srczone) || 325 osrczone != srczone) { 326 continue; 327 } 328 329 /* avoid unusable addresses */ 330 if ((ia->ia6_flags & 331 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { 332 continue; 333 } 334 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) 335 continue; 336 337 /* If jailed only take addresses of the jail into account. */ 338 if (cred != NULL && 339 prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0) 340 continue; 341 342 /* Rule 1: Prefer same address */ 343 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { 344 ia_best = ia; 345 BREAK(1); /* there should be no better candidate */ 346 } 347 348 if (ia_best == NULL) 349 REPLACE(0); 350 351 /* Rule 2: Prefer appropriate scope */ 352 if (dst_scope < 0) 353 dst_scope = in6_addrscope(&dst); 354 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); 355 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { 356 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) 357 REPLACE(2); 358 NEXT(2); 359 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { 360 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) 361 NEXT(2); 362 REPLACE(2); 363 } 364 365 /* 366 * Rule 3: Avoid deprecated addresses. Note that the case of 367 * !ip6_use_deprecated is already rejected above. 368 */ 369 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) 370 NEXT(3); 371 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) 372 REPLACE(3); 373 374 /* Rule 4: Prefer home addresses */ 375 /* 376 * XXX: This is a TODO. We should probably merge the MIP6 377 * case above. 378 */ 379 380 /* Rule 5: Prefer outgoing interface */ 381 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) { 382 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) 383 NEXT(5); 384 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) 385 REPLACE(5); 386 } 387 388 /* 389 * Rule 6: Prefer matching label 390 * Note that best_policy should be non-NULL here. 391 */ 392 if (dst_policy == NULL) 393 dst_policy = lookup_addrsel_policy(dstsock); 394 if (dst_policy->label != ADDR_LABEL_NOTAPP) { 395 new_policy = lookup_addrsel_policy(&ia->ia_addr); 396 if (dst_policy->label == best_policy->label && 397 dst_policy->label != new_policy->label) 398 NEXT(6); 399 if (dst_policy->label != best_policy->label && 400 dst_policy->label == new_policy->label) 401 REPLACE(6); 402 } 403 404 /* 405 * Rule 7: Prefer public addresses. 406 * We allow users to reverse the logic by configuring 407 * a sysctl variable, so that privacy conscious users can 408 * always prefer temporary addresses. 409 */ 410 if (opts == NULL || 411 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { 412 prefer_tempaddr = V_ip6_prefer_tempaddr; 413 } else if (opts->ip6po_prefer_tempaddr == 414 IP6PO_TEMPADDR_NOTPREFER) { 415 prefer_tempaddr = 0; 416 } else 417 prefer_tempaddr = 1; 418 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 419 (ia->ia6_flags & IN6_IFF_TEMPORARY)) { 420 if (prefer_tempaddr) 421 REPLACE(7); 422 else 423 NEXT(7); 424 } 425 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 426 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 427 if (prefer_tempaddr) 428 NEXT(7); 429 else 430 REPLACE(7); 431 } 432 433 /* 434 * Rule 8: prefer addresses on alive interfaces. 435 * This is a KAME specific rule. 436 */ 437 if ((ia_best->ia_ifp->if_flags & IFF_UP) && 438 !(ia->ia_ifp->if_flags & IFF_UP)) 439 NEXT(8); 440 if (!(ia_best->ia_ifp->if_flags & IFF_UP) && 441 (ia->ia_ifp->if_flags & IFF_UP)) 442 REPLACE(8); 443 444 /* 445 * Rule 9: prefer address with better virtual status. 446 */ 447 if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa)) 448 REPLACE(9); 449 if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa)) 450 NEXT(9); 451 452 /* 453 * Rule 10: prefer address with `prefer_source' flag. 454 */ 455 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 && 456 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0) 457 REPLACE(10); 458 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 && 459 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0) 460 NEXT(10); 461 462 /* 463 * Rule 14: Use longest matching prefix. 464 * Note: in the address selection draft, this rule is 465 * documented as "Rule 8". However, since it is also 466 * documented that this rule can be overridden, we assign 467 * a large number so that it is easy to assign smaller numbers 468 * to more preferred rules. 469 */ 470 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); 471 if (best_matchlen < new_matchlen) 472 REPLACE(14); 473 if (new_matchlen < best_matchlen) 474 NEXT(14); 475 476 /* Rule 15 is reserved. */ 477 478 /* 479 * Last resort: just keep the current candidate. 480 * Or, do we need more rules? 481 */ 482 continue; 483 484 replace: 485 ia_best = ia; 486 best_scope = (new_scope >= 0 ? new_scope : 487 in6_addrscope(&ia_best->ia_addr.sin6_addr)); 488 best_policy = (new_policy ? new_policy : 489 lookup_addrsel_policy(&ia_best->ia_addr)); 490 best_matchlen = (new_matchlen >= 0 ? new_matchlen : 491 in6_matchlen(&ia_best->ia_addr.sin6_addr, 492 &dst)); 493 494 next: 495 continue; 496 497 out: 498 break; 499 } 500 501 if ((ia = ia_best) == NULL) { 502 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 503 IP6STAT_INC(ip6s_sources_none); 504 return (EADDRNOTAVAIL); 505 } 506 507 /* 508 * At this point at least one of the addresses belonged to the jail 509 * but it could still be, that we want to further restrict it, e.g. 510 * theoratically IN6_IS_ADDR_LOOPBACK. 511 * It must not be IN6_IS_ADDR_UNSPECIFIED anymore. 512 * prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should 513 * let all others previously selected pass. 514 * Use tmp to not change ::1 on lo0 to the primary jail address. 515 */ 516 tmp = ia->ia_addr.sin6_addr; 517 if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL && 518 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) { 519 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 520 IP6STAT_INC(ip6s_sources_none); 521 return (EADDRNOTAVAIL); 522 } 523 524 if (ifpp) 525 *ifpp = ifp; 526 527 bcopy(&tmp, srcp, sizeof(*srcp)); 528 if (ia->ia_ifp == ifp) 529 IP6STAT_INC(ip6s_sources_sameif[best_scope]); 530 else 531 IP6STAT_INC(ip6s_sources_otherif[best_scope]); 532 if (dst_scope == best_scope) 533 IP6STAT_INC(ip6s_sources_samescope[best_scope]); 534 else 535 IP6STAT_INC(ip6s_sources_otherscope[best_scope]); 536 if (IFA6_IS_DEPRECATED(ia)) 537 IP6STAT_INC(ip6s_sources_deprecated[best_scope]); 538 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 539 return (0); 540 } 541 542 /* 543 * Select source address based on @inp, @dstsock and @opts. 544 * Stores selected address to @srcp. If @scope_ambiguous is set, 545 * embed scope from selected outgoing interface. If @hlim pointer 546 * is provided, stores calculated hop limit there. 547 * Returns 0 on success. 548 */ 549 int 550 in6_selectsrc_socket(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 551 struct inpcb *inp, struct ucred *cred, int scope_ambiguous, 552 struct in6_addr *srcp, int *hlim) 553 { 554 struct ifnet *retifp; 555 uint32_t fibnum; 556 int error; 557 558 fibnum = inp->inp_inc.inc_fibnum; 559 retifp = NULL; 560 561 error = in6_selectsrc(fibnum, dstsock, opts, inp, cred, &retifp, srcp); 562 if (error != 0) 563 return (error); 564 565 if (hlim != NULL) 566 *hlim = in6_selecthlim(inp, retifp); 567 568 if (retifp == NULL || scope_ambiguous == 0) 569 return (0); 570 571 /* 572 * Application should provide a proper zone ID or the use of 573 * default zone IDs should be enabled. Unfortunately, some 574 * applications do not behave as it should, so we need a 575 * workaround. Even if an appropriate ID is not determined 576 * (when it's required), if we can determine the outgoing 577 * interface. determine the zone ID based on the interface. 578 */ 579 error = in6_setscope(&dstsock->sin6_addr, retifp, NULL); 580 581 return (error); 582 } 583 584 /* 585 * Select source address based on @fibnum, @dst and @scopeid. 586 * Stores selected address to @srcp. 587 * Returns 0 on success. 588 * 589 * Used by non-socket based consumers (ND code mostly) 590 */ 591 int 592 in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst, 593 uint32_t scopeid, struct ifnet *ifp, struct in6_addr *srcp, 594 int *hlim) 595 { 596 struct ifnet *retifp; 597 struct sockaddr_in6 dst_sa; 598 int error; 599 600 retifp = ifp; 601 bzero(&dst_sa, sizeof(dst_sa)); 602 dst_sa.sin6_family = AF_INET6; 603 dst_sa.sin6_len = sizeof(dst_sa); 604 dst_sa.sin6_addr = *dst; 605 dst_sa.sin6_scope_id = scopeid; 606 sa6_embedscope(&dst_sa, 0); 607 608 error = in6_selectsrc(fibnum, &dst_sa, NULL, NULL, NULL, &retifp, srcp); 609 if (hlim != NULL) 610 *hlim = in6_selecthlim(NULL, retifp); 611 612 return (error); 613 } 614 615 /* 616 * clone - meaningful only for bsdi and freebsd 617 */ 618 static int 619 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 620 struct ip6_moptions *mopts, struct route_in6 *ro, 621 struct ifnet **retifp, struct nhop_object **retnh, int norouteok, 622 u_int fibnum, uint32_t flowid) 623 { 624 int error = 0; 625 struct ifnet *ifp = NULL; 626 struct nhop_object *nh = NULL; 627 struct sockaddr_in6 *sin6_next; 628 struct in6_pktinfo *pi = NULL; 629 struct in6_addr *dst = &dstsock->sin6_addr; 630 uint32_t zoneid; 631 #if 0 632 char ip6buf[INET6_ADDRSTRLEN]; 633 634 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 635 dstsock->sin6_addr.s6_addr32[1] == 0 && 636 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 637 printf("%s: strange destination %s\n", __func__, 638 ip6_sprintf(ip6buf, &dstsock->sin6_addr)); 639 } else { 640 printf("%s: destination = %s%%%d\n", __func__, 641 ip6_sprintf(ip6buf, &dstsock->sin6_addr), 642 dstsock->sin6_scope_id); /* for debug */ 643 } 644 #endif 645 646 /* If the caller specify the outgoing interface explicitly, use it. */ 647 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 648 /* XXX boundary check is assumed to be already done. */ 649 ifp = ifnet_byindex(pi->ipi6_ifindex); 650 if (ifp != NULL && 651 (norouteok || retnh == NULL || 652 IN6_IS_ADDR_MULTICAST(dst))) { 653 /* 654 * we do not have to check or get the route for 655 * multicast. 656 */ 657 goto done; 658 } else 659 goto getroute; 660 } 661 /* 662 * If the destination address is a multicast address and the outgoing 663 * interface for the address is specified by the caller, use it. 664 */ 665 if (IN6_IS_ADDR_MULTICAST(dst) && 666 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 667 goto done; /* we do not need a route for multicast. */ 668 } 669 /* 670 * If destination address is LLA or link- or node-local multicast, 671 * use it's embedded scope zone id to determine outgoing interface. 672 */ 673 if (IN6_IS_ADDR_MC_LINKLOCAL(dst) || 674 IN6_IS_ADDR_MC_NODELOCAL(dst)) { 675 zoneid = ntohs(in6_getscope(dst)); 676 if (zoneid > 0) { 677 ifp = in6_getlinkifnet(zoneid); 678 goto done; 679 } 680 } 681 682 getroute: 683 /* 684 * If the next hop address for the packet is specified by the caller, 685 * use it as the gateway. 686 */ 687 if (opts && opts->ip6po_nexthop) { 688 struct route_in6 *ron; 689 690 sin6_next = satosin6(opts->ip6po_nexthop); 691 if (IN6_IS_ADDR_LINKLOCAL(&sin6_next->sin6_addr)) { 692 /* 693 * Next hop is LLA, thus it should be neighbor. 694 * Determine outgoing interface by zone index. 695 */ 696 zoneid = ntohs(in6_getscope(&sin6_next->sin6_addr)); 697 if (zoneid > 0) { 698 ifp = in6_getlinkifnet(zoneid); 699 goto done; 700 } 701 } 702 ron = &opts->ip6po_nextroute; 703 /* Use a cached route if it exists and is valid. */ 704 if (ron->ro_nh != NULL && ( 705 !NH_IS_VALID(ron->ro_nh) || 706 ron->ro_dst.sin6_family != AF_INET6 || 707 !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr, 708 &sin6_next->sin6_addr))) 709 RO_NHFREE(ron); 710 if (ron->ro_nh == NULL) { 711 ron->ro_dst = *sin6_next; 712 /* 713 * sin6_next is not link-local OR scopeid is 0, 714 * no need to clear scope 715 */ 716 ron->ro_nh = fib6_lookup(fibnum, 717 &sin6_next->sin6_addr, 0, NHR_REF, flowid); 718 } 719 /* 720 * The node identified by that address must be a 721 * neighbor of the sending host. 722 */ 723 if (ron->ro_nh == NULL || 724 (ron->ro_nh->nh_flags & NHF_GATEWAY) != 0) 725 error = EHOSTUNREACH; 726 else { 727 nh = ron->ro_nh; 728 ifp = nh->nh_ifp; 729 } 730 goto done; 731 } 732 733 /* 734 * Use a cached route if it exists and is valid, else try to allocate 735 * a new one. Note that we should check the address family of the 736 * cached destination, in case of sharing the cache with IPv4. 737 */ 738 if (ro) { 739 if (ro->ro_nh && 740 (!NH_IS_VALID(ro->ro_nh) || 741 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 742 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 743 dst))) { 744 RO_NHFREE(ro); 745 } 746 if (ro->ro_nh == (struct nhop_object *)NULL) { 747 struct sockaddr_in6 *sa6; 748 749 /* No route yet, so try to acquire one */ 750 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 751 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 752 *sa6 = *dstsock; 753 sa6->sin6_scope_id = 0; 754 755 /* 756 * Currently dst has scopeid embedded iff it is LL. 757 * New routing API accepts scopeid as a separate argument. 758 * Convert dst before/after doing lookup 759 */ 760 uint32_t scopeid = 0; 761 if (IN6_IS_SCOPE_LINKLOCAL(&sa6->sin6_addr)) { 762 /* Unwrap in6_getscope() and in6_clearscope() */ 763 scopeid = ntohs(sa6->sin6_addr.s6_addr16[1]); 764 sa6->sin6_addr.s6_addr16[1] = 0; 765 } 766 767 ro->ro_nh = fib6_lookup(fibnum, 768 &sa6->sin6_addr, scopeid, NHR_REF, flowid); 769 770 if (IN6_IS_SCOPE_LINKLOCAL(&sa6->sin6_addr)) 771 sa6->sin6_addr.s6_addr16[1] = htons(scopeid); 772 } 773 774 /* 775 * do not care about the result if we have the nexthop 776 * explicitly specified. 777 */ 778 if (opts && opts->ip6po_nexthop) 779 goto done; 780 781 if (ro->ro_nh) 782 ifp = ro->ro_nh->nh_ifp; 783 else 784 error = EHOSTUNREACH; 785 nh = ro->ro_nh; 786 787 /* 788 * Check if the outgoing interface conflicts with 789 * the interface specified by ipi6_ifindex (if specified). 790 * Note that loopback interface is always okay. 791 * (this may happen when we are sending a packet to one of 792 * our own addresses.) 793 */ 794 if (ifp && opts && opts->ip6po_pktinfo && 795 opts->ip6po_pktinfo->ipi6_ifindex) { 796 if (!(ifp->if_flags & IFF_LOOPBACK) && 797 ifp->if_index != 798 opts->ip6po_pktinfo->ipi6_ifindex) { 799 error = EHOSTUNREACH; 800 goto done; 801 } 802 } 803 } 804 805 done: 806 if (ifp == NULL && nh == NULL) { 807 /* 808 * This can happen if the caller did not pass a cached route 809 * nor any other hints. We treat this case an error. 810 */ 811 error = EHOSTUNREACH; 812 } 813 if (error == EHOSTUNREACH) 814 IP6STAT_INC(ip6s_noroute); 815 816 if (retifp != NULL) { 817 if (nh != NULL) 818 *retifp = nh->nh_aifp; 819 else 820 *retifp = ifp; 821 } 822 823 if (retnh != NULL) 824 *retnh = nh; /* nh may be NULL */ 825 826 return (error); 827 } 828 829 static int 830 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 831 struct ip6_moptions *mopts, struct ifnet **retifp, 832 struct ifnet *oifp, u_int fibnum) 833 { 834 int error; 835 struct route_in6 sro; 836 struct nhop_object *nh = NULL; 837 uint16_t nh_flags; 838 839 KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__)); 840 841 bzero(&sro, sizeof(sro)); 842 nh_flags = 0; 843 844 error = selectroute(dstsock, opts, mopts, &sro, retifp, &nh, 1, fibnum, 0); 845 846 if (nh != NULL) 847 nh_flags = nh->nh_flags; 848 if (nh != NULL && nh == sro.ro_nh) 849 NH_FREE(nh); 850 851 if (error != 0) { 852 /* Help ND. See oifp comment in in6_selectsrc(). */ 853 if (oifp != NULL && fibnum == RT_DEFAULT_FIB) { 854 *retifp = oifp; 855 error = 0; 856 } 857 return (error); 858 } 859 860 /* 861 * do not use a rejected or black hole route. 862 * XXX: this check should be done in the L2 output routine. 863 * However, if we skipped this check here, we'd see the following 864 * scenario: 865 * - install a rejected route for a scoped address prefix 866 * (like fe80::/10) 867 * - send a packet to a destination that matches the scoped prefix, 868 * with ambiguity about the scope zone. 869 * - pick the outgoing interface from the route, and disambiguate the 870 * scope zone with the interface. 871 * - ip6_output() would try to get another route with the "new" 872 * destination, which may be valid. 873 * - we'd see no error on output. 874 * Although this may not be very harmful, it should still be confusing. 875 * We thus reject the case here. 876 */ 877 878 if (nh_flags & (NHF_REJECT | NHF_BLACKHOLE)) { 879 error = (nh_flags & NHF_HOST ? EHOSTUNREACH : ENETUNREACH); 880 return (error); 881 } 882 883 return (0); 884 } 885 886 /* Public wrapper function to selectroute(). */ 887 int 888 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 889 struct ip6_moptions *mopts, struct route_in6 *ro, 890 struct ifnet **retifp, struct nhop_object **retnh, u_int fibnum, uint32_t flowid) 891 { 892 893 return (selectroute(dstsock, opts, mopts, ro, retifp, 894 retnh, 0, fibnum, flowid)); 895 } 896 897 /* 898 * Default hop limit selection. The precedence is as follows: 899 * 1. Hoplimit value specified via ioctl. 900 * 2. (If the outgoing interface is detected) the current 901 * hop limit of the interface specified by router advertisement. 902 * 3. The system default hoplimit. 903 */ 904 int 905 in6_selecthlim(struct inpcb *inp, struct ifnet *ifp) 906 { 907 908 if (inp && inp->in6p_hops >= 0) 909 return (inp->in6p_hops); 910 else if (ifp) 911 return (ND_IFINFO(ifp)->chlim); 912 else if (inp && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) { 913 struct nhop_object *nh; 914 struct in6_addr dst; 915 uint32_t fibnum, scopeid; 916 int hlim; 917 918 fibnum = inp->inp_inc.inc_fibnum; 919 in6_splitscope(&inp->in6p_faddr, &dst, &scopeid); 920 nh = fib6_lookup(fibnum, &dst, scopeid, 0, 0); 921 if (nh != NULL) { 922 hlim = ND_IFINFO(nh->nh_ifp)->chlim; 923 return (hlim); 924 } 925 } 926 return (V_ip6_defhlim); 927 } 928 929 void 930 addrsel_policy_init(void) 931 { 932 933 init_policy_queue(); 934 935 /* initialize the "last resort" policy */ 936 bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy)); 937 V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; 938 939 if (!IS_DEFAULT_VNET(curvnet)) 940 return; 941 942 ADDRSEL_LOCK_INIT(); 943 ADDRSEL_SXLOCK_INIT(); 944 } 945 946 static struct in6_addrpolicy * 947 lookup_addrsel_policy(struct sockaddr_in6 *key) 948 { 949 struct in6_addrpolicy *match = NULL; 950 951 ADDRSEL_LOCK(); 952 match = match_addrsel_policy(key); 953 954 if (match == NULL) 955 match = &V_defaultaddrpolicy; 956 else 957 match->use++; 958 ADDRSEL_UNLOCK(); 959 960 return (match); 961 } 962 963 /* 964 * Subroutines to manage the address selection policy table via sysctl. 965 */ 966 struct walkarg { 967 struct sysctl_req *w_req; 968 }; 969 970 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); 971 SYSCTL_DECL(_net_inet6_ip6); 972 static SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, 973 CTLFLAG_RD | CTLFLAG_MPSAFE, in6_src_sysctl, 974 ""); 975 976 static int 977 in6_src_sysctl(SYSCTL_HANDLER_ARGS) 978 { 979 struct walkarg w; 980 981 if (req->newptr) 982 return EPERM; 983 984 bzero(&w, sizeof(w)); 985 w.w_req = req; 986 987 return (walk_addrsel_policy(dump_addrsel_policyent, &w)); 988 } 989 990 int 991 in6_src_ioctl(u_long cmd, caddr_t data) 992 { 993 struct in6_addrpolicy ent0; 994 995 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) 996 return (EOPNOTSUPP); /* check for safety */ 997 998 ent0 = *(struct in6_addrpolicy *)data; 999 1000 if (ent0.label == ADDR_LABEL_NOTAPP) 1001 return (EINVAL); 1002 /* check if the prefix mask is consecutive. */ 1003 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) 1004 return (EINVAL); 1005 /* clear trailing garbages (if any) of the prefix address. */ 1006 IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr); 1007 ent0.use = 0; 1008 1009 switch (cmd) { 1010 case SIOCAADDRCTL_POLICY: 1011 return (add_addrsel_policyent(&ent0)); 1012 case SIOCDADDRCTL_POLICY: 1013 return (delete_addrsel_policyent(&ent0)); 1014 } 1015 1016 return (0); /* XXX: compromise compilers */ 1017 } 1018 1019 /* 1020 * The followings are implementation of the policy table using a 1021 * simple tail queue. 1022 * XXX such details should be hidden. 1023 * XXX implementation using binary tree should be more efficient. 1024 */ 1025 struct addrsel_policyent { 1026 TAILQ_ENTRY(addrsel_policyent) ape_entry; 1027 struct in6_addrpolicy ape_policy; 1028 }; 1029 1030 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); 1031 1032 VNET_DEFINE_STATIC(struct addrsel_policyhead, addrsel_policytab); 1033 #define V_addrsel_policytab VNET(addrsel_policytab) 1034 1035 static void 1036 init_policy_queue(void) 1037 { 1038 1039 TAILQ_INIT(&V_addrsel_policytab); 1040 } 1041 1042 static int 1043 add_addrsel_policyent(struct in6_addrpolicy *newpolicy) 1044 { 1045 struct addrsel_policyent *new, *pol; 1046 1047 new = malloc(sizeof(*new), M_IFADDR, 1048 M_WAITOK); 1049 ADDRSEL_XLOCK(); 1050 ADDRSEL_LOCK(); 1051 1052 /* duplication check */ 1053 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1054 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, 1055 &pol->ape_policy.addr.sin6_addr) && 1056 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, 1057 &pol->ape_policy.addrmask.sin6_addr)) { 1058 ADDRSEL_UNLOCK(); 1059 ADDRSEL_XUNLOCK(); 1060 free(new, M_IFADDR); 1061 return (EEXIST); /* or override it? */ 1062 } 1063 } 1064 1065 bzero(new, sizeof(*new)); 1066 1067 /* XXX: should validate entry */ 1068 new->ape_policy = *newpolicy; 1069 1070 TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry); 1071 ADDRSEL_UNLOCK(); 1072 ADDRSEL_XUNLOCK(); 1073 1074 return (0); 1075 } 1076 1077 static int 1078 delete_addrsel_policyent(struct in6_addrpolicy *key) 1079 { 1080 struct addrsel_policyent *pol; 1081 1082 ADDRSEL_XLOCK(); 1083 ADDRSEL_LOCK(); 1084 1085 /* search for the entry in the table */ 1086 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1087 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, 1088 &pol->ape_policy.addr.sin6_addr) && 1089 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, 1090 &pol->ape_policy.addrmask.sin6_addr)) { 1091 break; 1092 } 1093 } 1094 if (pol == NULL) { 1095 ADDRSEL_UNLOCK(); 1096 ADDRSEL_XUNLOCK(); 1097 return (ESRCH); 1098 } 1099 1100 TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry); 1101 ADDRSEL_UNLOCK(); 1102 ADDRSEL_XUNLOCK(); 1103 free(pol, M_IFADDR); 1104 1105 return (0); 1106 } 1107 1108 static int 1109 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w) 1110 { 1111 struct addrsel_policyent *pol; 1112 int error = 0; 1113 1114 ADDRSEL_SLOCK(); 1115 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1116 if ((error = (*callback)(&pol->ape_policy, w)) != 0) { 1117 ADDRSEL_SUNLOCK(); 1118 return (error); 1119 } 1120 } 1121 ADDRSEL_SUNLOCK(); 1122 return (error); 1123 } 1124 1125 static int 1126 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) 1127 { 1128 int error = 0; 1129 struct walkarg *w = arg; 1130 1131 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); 1132 1133 return (error); 1134 } 1135 1136 static struct in6_addrpolicy * 1137 match_addrsel_policy(struct sockaddr_in6 *key) 1138 { 1139 struct addrsel_policyent *pent; 1140 struct in6_addrpolicy *bestpol = NULL, *pol; 1141 int matchlen, bestmatchlen = -1; 1142 u_char *mp, *ep, *k, *p, m; 1143 1144 TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) { 1145 matchlen = 0; 1146 1147 pol = &pent->ape_policy; 1148 mp = (u_char *)&pol->addrmask.sin6_addr; 1149 ep = mp + 16; /* XXX: scope field? */ 1150 k = (u_char *)&key->sin6_addr; 1151 p = (u_char *)&pol->addr.sin6_addr; 1152 for (; mp < ep && *mp; mp++, k++, p++) { 1153 m = *mp; 1154 if ((*k & m) != *p) 1155 goto next; /* not match */ 1156 if (m == 0xff) /* short cut for a typical case */ 1157 matchlen += 8; 1158 else { 1159 while (m >= 0x80) { 1160 matchlen++; 1161 m <<= 1; 1162 } 1163 } 1164 } 1165 1166 /* matched. check if this is better than the current best. */ 1167 if (bestpol == NULL || 1168 matchlen > bestmatchlen) { 1169 bestpol = pol; 1170 bestmatchlen = matchlen; 1171 } 1172 1173 next: 1174 continue; 1175 } 1176 1177 return (bestpol); 1178 } 1179