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/if_private.h> 92 #include <net/route.h> 93 #include <net/route/nhop.h> 94 #include <net/if_llatbl.h> 95 96 #include <netinet/in.h> 97 #include <netinet/in_var.h> 98 #include <netinet/in_systm.h> 99 #include <netinet/ip.h> 100 #include <netinet/in_pcb.h> 101 #include <netinet/ip_var.h> 102 #include <netinet/udp.h> 103 #include <netinet/udp_var.h> 104 105 #include <netinet6/in6_var.h> 106 #include <netinet/ip6.h> 107 #include <netinet6/in6_fib.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 VNET_DEFINE_STATIC(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 nhop_object **, int, u_int, uint32_t); 135 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 136 struct ip6_moptions *, struct ifnet **, 137 struct ifnet *, u_int); 138 static int in6_selectsrc(uint32_t, struct sockaddr_in6 *, 139 struct ip6_pktopts *, struct inpcb *, struct ucred *, 140 struct ifnet **, struct in6_addr *); 141 142 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); 143 144 static void init_policy_queue(void); 145 static int add_addrsel_policyent(struct in6_addrpolicy *); 146 static int delete_addrsel_policyent(struct in6_addrpolicy *); 147 static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *), 148 void *); 149 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); 150 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); 151 152 /* 153 * Return an IPv6 address, which is the most appropriate for a given 154 * destination and user specified options. 155 * If necessary, this function lookups the routing table and returns 156 * an entry to the caller for later use. 157 */ 158 #define REPLACE(r) do {\ 159 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 160 /* { \ 161 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 162 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)); \ 163 } */ \ 164 goto replace; \ 165 } while(0) 166 #define NEXT(r) do {\ 167 /* { \ 168 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 169 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)); \ 170 } */ \ 171 goto next; /* XXX: we can't use 'continue' here */ \ 172 } while(0) 173 #define BREAK(r) do { \ 174 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 175 goto out; /* XXX: we can't use 'break' here */ \ 176 } while(0) 177 178 static int 179 in6_selectsrc(uint32_t fibnum, struct sockaddr_in6 *dstsock, 180 struct ip6_pktopts *opts, struct inpcb *inp, struct ucred *cred, 181 struct ifnet **ifpp, struct in6_addr *srcp) 182 { 183 struct rm_priotracker in6_ifa_tracker; 184 struct in6_addr dst, tmp; 185 struct ifnet *ifp = NULL, *oifp = NULL; 186 struct in6_ifaddr *ia = NULL, *ia_best = NULL; 187 struct in6_pktinfo *pi = NULL; 188 int dst_scope = -1, best_scope = -1, best_matchlen = -1; 189 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; 190 u_int32_t odstzone; 191 int prefer_tempaddr; 192 int error; 193 struct ip6_moptions *mopts; 194 195 NET_EPOCH_ASSERT(); 196 KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__)); 197 198 dst = dstsock->sin6_addr; /* make a copy for local operation */ 199 if (ifpp) { 200 /* 201 * Save a possibly passed in ifp for in6_selectsrc. Only 202 * neighbor discovery code should use this feature, where 203 * we may know the interface but not the FIB number holding 204 * the connected subnet in case someone deleted it from the 205 * default FIB and we need to check the interface. 206 */ 207 if (*ifpp != NULL) 208 oifp = *ifpp; 209 *ifpp = NULL; 210 } 211 212 if (inp != NULL) { 213 INP_LOCK_ASSERT(inp); 214 mopts = inp->in6p_moptions; 215 } else { 216 mopts = NULL; 217 } 218 219 /* 220 * If the source address is explicitly specified by the caller, 221 * check if the requested source address is indeed a unicast address 222 * assigned to the node, and can be used as the packet's source 223 * address. If everything is okay, use the address as source. 224 */ 225 if (opts && (pi = opts->ip6po_pktinfo) && 226 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 227 /* get the outgoing interface */ 228 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp, 229 fibnum)) 230 != 0) 231 return (error); 232 233 /* 234 * determine the appropriate zone id of the source based on 235 * the zone of the destination and the outgoing interface. 236 * If the specified address is ambiguous wrt the scope zone, 237 * the interface must be specified; otherwise, ifa_ifwithaddr() 238 * will fail matching the address. 239 */ 240 tmp = pi->ipi6_addr; 241 if (ifp) { 242 error = in6_setscope(&tmp, ifp, &odstzone); 243 if (error) 244 return (error); 245 } 246 if (cred != NULL && (error = prison_local_ip6(cred, 247 &tmp, (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) 248 return (error); 249 250 /* 251 * If IPV6_BINDANY socket option is set, we allow to specify 252 * non local addresses as source address in IPV6_PKTINFO 253 * ancillary data. 254 */ 255 if ((inp->inp_flags & INP_BINDANY) == 0) { 256 ia = in6ifa_ifwithaddr(&tmp, 0 /* XXX */, false); 257 if (ia == NULL || (ia->ia6_flags & (IN6_IFF_ANYCAST | 258 IN6_IFF_NOTREADY))) 259 return (EADDRNOTAVAIL); 260 bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp)); 261 } else 262 bcopy(&tmp, srcp, sizeof(*srcp)); 263 pi->ipi6_addr = tmp; /* XXX: this overrides pi */ 264 if (ifpp) 265 *ifpp = ifp; 266 return (0); 267 } 268 269 /* 270 * Otherwise, if the socket has already bound the source, just use it. 271 */ 272 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { 273 if (cred != NULL && 274 (error = prison_local_ip6(cred, &inp->in6p_laddr, 275 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 276 return (error); 277 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp)); 278 return (0); 279 } 280 281 /* 282 * Bypass source address selection and use the primary jail IP 283 * if requested. 284 */ 285 if (cred != NULL && !prison_saddrsel_ip6(cred, srcp)) 286 return (0); 287 288 /* 289 * If the address is not specified, choose the best one based on 290 * the outgoing interface and the destination address. 291 */ 292 /* get the outgoing interface */ 293 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp, 294 (inp != NULL) ? inp->inp_inc.inc_fibnum : fibnum)) != 0) 295 return (error); 296 297 #ifdef DIAGNOSTIC 298 if (ifp == NULL) /* this should not happen */ 299 panic("in6_selectsrc: NULL ifp"); 300 #endif 301 error = in6_setscope(&dst, ifp, &odstzone); 302 if (error) 303 return (error); 304 305 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 306 CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 307 int new_scope = -1, new_matchlen = -1; 308 struct in6_addrpolicy *new_policy = NULL; 309 u_int32_t srczone, osrczone, dstzone; 310 struct in6_addr src; 311 struct ifnet *ifp1 = ia->ia_ifp; 312 313 /* 314 * We'll never take an address that breaks the scope zone 315 * of the destination. We also skip an address if its zone 316 * does not contain the outgoing interface. 317 * XXX: we should probably use sin6_scope_id here. 318 */ 319 if (in6_setscope(&dst, ifp1, &dstzone) || 320 odstzone != dstzone) { 321 continue; 322 } 323 src = ia->ia_addr.sin6_addr; 324 if (in6_setscope(&src, ifp, &osrczone) || 325 in6_setscope(&src, ifp1, &srczone) || 326 osrczone != srczone) { 327 continue; 328 } 329 330 /* avoid unusable addresses */ 331 if ((ia->ia6_flags & 332 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { 333 continue; 334 } 335 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) 336 continue; 337 338 /* If jailed only take addresses of the jail into account. */ 339 if (cred != NULL && 340 prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0) 341 continue; 342 343 /* Rule 1: Prefer same address */ 344 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { 345 ia_best = ia; 346 BREAK(1); /* there should be no better candidate */ 347 } 348 349 if (ia_best == NULL) 350 REPLACE(0); 351 352 /* Rule 2: Prefer appropriate scope */ 353 if (dst_scope < 0) 354 dst_scope = in6_addrscope(&dst); 355 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); 356 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { 357 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) 358 REPLACE(2); 359 NEXT(2); 360 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { 361 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) 362 NEXT(2); 363 REPLACE(2); 364 } 365 366 /* 367 * Rule 3: Avoid deprecated addresses. Note that the case of 368 * !ip6_use_deprecated is already rejected above. 369 */ 370 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) 371 NEXT(3); 372 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) 373 REPLACE(3); 374 375 /* Rule 4: Prefer home addresses */ 376 /* 377 * XXX: This is a TODO. We should probably merge the MIP6 378 * case above. 379 */ 380 381 /* Rule 5: Prefer outgoing interface */ 382 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) { 383 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) 384 NEXT(5); 385 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) 386 REPLACE(5); 387 } 388 389 /* 390 * Rule 6: Prefer matching label 391 * Note that best_policy should be non-NULL here. 392 */ 393 if (dst_policy == NULL) 394 dst_policy = lookup_addrsel_policy(dstsock); 395 if (dst_policy->label != ADDR_LABEL_NOTAPP) { 396 new_policy = lookup_addrsel_policy(&ia->ia_addr); 397 if (dst_policy->label == best_policy->label && 398 dst_policy->label != new_policy->label) 399 NEXT(6); 400 if (dst_policy->label != best_policy->label && 401 dst_policy->label == new_policy->label) 402 REPLACE(6); 403 } 404 405 /* 406 * Rule 7: Prefer public addresses. 407 * We allow users to reverse the logic by configuring 408 * a sysctl variable, so that privacy conscious users can 409 * always prefer temporary addresses. 410 */ 411 if (opts == NULL || 412 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { 413 prefer_tempaddr = V_ip6_prefer_tempaddr; 414 } else if (opts->ip6po_prefer_tempaddr == 415 IP6PO_TEMPADDR_NOTPREFER) { 416 prefer_tempaddr = 0; 417 } else 418 prefer_tempaddr = 1; 419 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 420 (ia->ia6_flags & IN6_IFF_TEMPORARY)) { 421 if (prefer_tempaddr) 422 REPLACE(7); 423 else 424 NEXT(7); 425 } 426 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 427 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 428 if (prefer_tempaddr) 429 NEXT(7); 430 else 431 REPLACE(7); 432 } 433 434 /* 435 * Rule 8: prefer addresses on alive interfaces. 436 * This is a KAME specific rule. 437 */ 438 if ((ia_best->ia_ifp->if_flags & IFF_UP) && 439 !(ia->ia_ifp->if_flags & IFF_UP)) 440 NEXT(8); 441 if (!(ia_best->ia_ifp->if_flags & IFF_UP) && 442 (ia->ia_ifp->if_flags & IFF_UP)) 443 REPLACE(8); 444 445 /* 446 * Rule 9: prefer address with better virtual status. 447 */ 448 if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa)) 449 REPLACE(9); 450 if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa)) 451 NEXT(9); 452 453 /* 454 * Rule 10: prefer address with `prefer_source' flag. 455 */ 456 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 && 457 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0) 458 REPLACE(10); 459 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 && 460 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0) 461 NEXT(10); 462 463 /* 464 * Rule 14: Use longest matching prefix. 465 * Note: in the address selection draft, this rule is 466 * documented as "Rule 8". However, since it is also 467 * documented that this rule can be overridden, we assign 468 * a large number so that it is easy to assign smaller numbers 469 * to more preferred rules. 470 */ 471 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); 472 if (best_matchlen < new_matchlen) 473 REPLACE(14); 474 if (new_matchlen < best_matchlen) 475 NEXT(14); 476 477 /* Rule 15 is reserved. */ 478 479 /* 480 * Last resort: just keep the current candidate. 481 * Or, do we need more rules? 482 */ 483 continue; 484 485 replace: 486 ia_best = ia; 487 best_scope = (new_scope >= 0 ? new_scope : 488 in6_addrscope(&ia_best->ia_addr.sin6_addr)); 489 best_policy = (new_policy ? new_policy : 490 lookup_addrsel_policy(&ia_best->ia_addr)); 491 best_matchlen = (new_matchlen >= 0 ? new_matchlen : 492 in6_matchlen(&ia_best->ia_addr.sin6_addr, 493 &dst)); 494 495 next: 496 continue; 497 498 out: 499 break; 500 } 501 502 if ((ia = ia_best) == NULL) { 503 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 504 IP6STAT_INC(ip6s_sources_none); 505 return (EADDRNOTAVAIL); 506 } 507 508 /* 509 * At this point at least one of the addresses belonged to the jail 510 * but it could still be, that we want to further restrict it, e.g. 511 * theoratically IN6_IS_ADDR_LOOPBACK. 512 * It must not be IN6_IS_ADDR_UNSPECIFIED anymore. 513 * prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should 514 * let all others previously selected pass. 515 * Use tmp to not change ::1 on lo0 to the primary jail address. 516 */ 517 tmp = ia->ia_addr.sin6_addr; 518 if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL && 519 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) { 520 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 521 IP6STAT_INC(ip6s_sources_none); 522 return (EADDRNOTAVAIL); 523 } 524 525 if (ifpp) 526 *ifpp = ifp; 527 528 bcopy(&tmp, srcp, sizeof(*srcp)); 529 if (ia->ia_ifp == ifp) 530 IP6STAT_INC(ip6s_sources_sameif[best_scope]); 531 else 532 IP6STAT_INC(ip6s_sources_otherif[best_scope]); 533 if (dst_scope == best_scope) 534 IP6STAT_INC(ip6s_sources_samescope[best_scope]); 535 else 536 IP6STAT_INC(ip6s_sources_otherscope[best_scope]); 537 if (IFA6_IS_DEPRECATED(ia)) 538 IP6STAT_INC(ip6s_sources_deprecated[best_scope]); 539 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 540 return (0); 541 } 542 543 /* 544 * Select source address based on @inp, @dstsock and @opts. 545 * Stores selected address to @srcp. If @scope_ambiguous is set, 546 * embed scope from selected outgoing interface. If @hlim pointer 547 * is provided, stores calculated hop limit there. 548 * Returns 0 on success. 549 */ 550 int 551 in6_selectsrc_socket(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 552 struct inpcb *inp, struct ucred *cred, int scope_ambiguous, 553 struct in6_addr *srcp, int *hlim) 554 { 555 struct ifnet *retifp; 556 uint32_t fibnum; 557 int error; 558 559 fibnum = inp->inp_inc.inc_fibnum; 560 retifp = NULL; 561 562 error = in6_selectsrc(fibnum, dstsock, opts, inp, cred, &retifp, srcp); 563 if (error != 0) 564 return (error); 565 566 if (hlim != NULL) 567 *hlim = in6_selecthlim(inp, retifp); 568 569 if (retifp == NULL || scope_ambiguous == 0) 570 return (0); 571 572 /* 573 * Application should provide a proper zone ID or the use of 574 * default zone IDs should be enabled. Unfortunately, some 575 * applications do not behave as it should, so we need a 576 * workaround. Even if an appropriate ID is not determined 577 * (when it's required), if we can determine the outgoing 578 * interface. determine the zone ID based on the interface. 579 */ 580 error = in6_setscope(&dstsock->sin6_addr, retifp, NULL); 581 582 return (error); 583 } 584 585 /* 586 * Select source address based on @fibnum, @dst and @scopeid. 587 * Stores selected address to @srcp. 588 * Returns 0 on success. 589 * 590 * Used by non-socket based consumers (ND code mostly) 591 */ 592 int 593 in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst, 594 uint32_t scopeid, struct ifnet *ifp, struct in6_addr *srcp, 595 int *hlim) 596 { 597 struct ifnet *retifp; 598 struct sockaddr_in6 dst_sa; 599 int error; 600 601 retifp = ifp; 602 bzero(&dst_sa, sizeof(dst_sa)); 603 dst_sa.sin6_family = AF_INET6; 604 dst_sa.sin6_len = sizeof(dst_sa); 605 dst_sa.sin6_addr = *dst; 606 dst_sa.sin6_scope_id = scopeid; 607 sa6_embedscope(&dst_sa, 0); 608 609 error = in6_selectsrc(fibnum, &dst_sa, NULL, NULL, NULL, &retifp, srcp); 610 if (hlim != NULL) 611 *hlim = in6_selecthlim(NULL, retifp); 612 613 return (error); 614 } 615 616 static struct nhop_object * 617 cache_route(uint32_t fibnum, const struct sockaddr_in6 *dst, struct route_in6 *ro, 618 uint32_t flowid) 619 { 620 /* 621 * Use a cached route if it exists and is valid, else try to allocate 622 * a new one. Note that we should check the address family of the 623 * cached destination, in case of sharing the cache with IPv4. 624 * Assumes that 'struct route_in6' is exclusively locked. 625 */ 626 if (ro->ro_nh != NULL && ( 627 !NH_IS_VALID(ro->ro_nh) || ro->ro_dst.sin6_family != AF_INET6 || 628 !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &dst->sin6_addr))) 629 RO_NHFREE(ro); 630 631 if (ro->ro_nh == NULL) { 632 ro->ro_dst = *dst; 633 634 const struct in6_addr *paddr; 635 struct in6_addr unscoped_addr; 636 uint32_t scopeid = 0; 637 if (IN6_IS_SCOPE_LINKLOCAL(&dst->sin6_addr)) { 638 in6_splitscope(&dst->sin6_addr, &unscoped_addr, &scopeid); 639 paddr = &unscoped_addr; 640 } else 641 paddr = &dst->sin6_addr; 642 ro->ro_nh = fib6_lookup(fibnum, paddr, scopeid, NHR_REF, flowid); 643 } 644 return (ro->ro_nh); 645 } 646 647 static struct nhop_object * 648 lookup_route(uint32_t fibnum, struct sockaddr_in6 *dst, struct route_in6 *ro, 649 struct ip6_pktopts *opts, uint32_t flowid) 650 { 651 struct nhop_object *nh = NULL; 652 653 /* 654 * If the next hop address for the packet is specified by the caller, 655 * use it as the gateway. 656 */ 657 if (opts && opts->ip6po_nexthop) { 658 struct route_in6 *ron = &opts->ip6po_nextroute; 659 struct sockaddr_in6 *sin6_next = satosin6(opts->ip6po_nexthop); 660 661 nh = cache_route(fibnum, sin6_next, ron, flowid); 662 663 /* 664 * The node identified by that address must be a 665 * neighbor of the sending host. 666 */ 667 if (nh != NULL && (nh->nh_flags & NHF_GATEWAY) != 0) 668 nh = NULL; 669 } else if (ro != NULL) { 670 nh = cache_route(fibnum, dst, ro, flowid); 671 if (nh == NULL) 672 return (NULL); 673 674 /* 675 * Check if the outgoing interface conflicts with 676 * the interface specified by ipi6_ifindex (if specified). 677 */ 678 struct in6_pktinfo *pi; 679 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 680 if (nh->nh_aifp->if_index != pi->ipi6_ifindex) 681 nh = NULL; 682 } 683 } 684 685 return (nh); 686 } 687 688 /* 689 * Finds outgoing nexthop or the outgoing interface for the 690 * @dstsock. 691 * Return 0 on success and stores the lookup result in @retnh and @retifp 692 */ 693 static int 694 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 695 struct ip6_moptions *mopts, struct route_in6 *ro, 696 struct ifnet **retifp, struct nhop_object **retnh, int norouteok, 697 u_int fibnum, uint32_t flowid) 698 { 699 int error = 0; 700 struct ifnet *ifp = NULL; 701 struct in6_pktinfo *pi = NULL; 702 struct in6_addr *dst = &dstsock->sin6_addr; 703 704 /* If the caller specify the outgoing interface explicitly, use it. */ 705 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 706 /* XXX boundary check is assumed to be already done. */ 707 ifp = ifnet_byindex(pi->ipi6_ifindex); 708 if (ifp != NULL && (norouteok || IN6_IS_ADDR_MULTICAST(dst))) { 709 /* 710 * we do not have to check or get the route for 711 * multicast. 712 */ 713 goto done; 714 } else 715 goto getroute; 716 } 717 /* 718 * If the destination address is a multicast address and the outgoing 719 * interface for the address is specified by the caller, use it. 720 */ 721 if (IN6_IS_ADDR_MULTICAST(dst) && 722 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 723 goto done; /* we do not need a route for multicast. */ 724 } 725 /* 726 * If destination address is LLA or link- or node-local multicast, 727 * use it's embedded scope zone id to determine outgoing interface. 728 */ 729 if (IN6_IS_ADDR_MC_LINKLOCAL(dst) || 730 IN6_IS_ADDR_MC_NODELOCAL(dst)) { 731 uint32_t zoneid = ntohs(in6_getscope(dst)); 732 if (zoneid > 0) { 733 ifp = in6_getlinkifnet(zoneid); 734 goto done; 735 } 736 } 737 738 getroute:; 739 struct nhop_object *nh = lookup_route(fibnum, dstsock, ro, opts, flowid); 740 if (nh != NULL) { 741 *retifp = nh->nh_aifp; 742 error = 0; 743 } else { 744 *retifp = NULL; 745 IP6STAT_INC(ip6s_noroute); 746 error = EHOSTUNREACH; 747 } 748 *retnh = nh; 749 return (error); 750 751 done: 752 if (ifp == NULL) { 753 /* 754 * This can happen if the caller did not pass a cached route 755 * nor any other hints. We treat this case an error. 756 */ 757 error = EHOSTUNREACH; 758 } 759 if (error == EHOSTUNREACH) 760 IP6STAT_INC(ip6s_noroute); 761 762 *retifp = ifp; 763 *retnh = NULL; 764 765 return (error); 766 } 767 768 static int 769 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 770 struct ip6_moptions *mopts, struct ifnet **retifp, 771 struct ifnet *oifp, u_int fibnum) 772 { 773 int error; 774 struct route_in6 sro; 775 struct nhop_object *nh = NULL; 776 uint16_t nh_flags; 777 778 KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__)); 779 780 bzero(&sro, sizeof(sro)); 781 nh_flags = 0; 782 783 error = selectroute(dstsock, opts, mopts, &sro, retifp, &nh, 1, fibnum, 0); 784 785 if (nh != NULL) 786 nh_flags = nh->nh_flags; 787 if (nh != NULL && nh == sro.ro_nh) 788 NH_FREE(nh); 789 790 if (error != 0) { 791 /* Help ND. See oifp comment in in6_selectsrc(). */ 792 if (oifp != NULL && fibnum == RT_DEFAULT_FIB) { 793 *retifp = oifp; 794 error = 0; 795 } 796 return (error); 797 } 798 799 /* 800 * do not use a rejected or black hole route. 801 * XXX: this check should be done in the L2 output routine. 802 * However, if we skipped this check here, we'd see the following 803 * scenario: 804 * - install a rejected route for a scoped address prefix 805 * (like fe80::/10) 806 * - send a packet to a destination that matches the scoped prefix, 807 * with ambiguity about the scope zone. 808 * - pick the outgoing interface from the route, and disambiguate the 809 * scope zone with the interface. 810 * - ip6_output() would try to get another route with the "new" 811 * destination, which may be valid. 812 * - we'd see no error on output. 813 * Although this may not be very harmful, it should still be confusing. 814 * We thus reject the case here. 815 */ 816 817 if (nh_flags & (NHF_REJECT | NHF_BLACKHOLE)) { 818 error = (nh_flags & NHF_HOST ? EHOSTUNREACH : ENETUNREACH); 819 return (error); 820 } 821 822 return (0); 823 } 824 825 /* Public wrapper function to selectroute(). */ 826 int 827 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 828 struct ip6_moptions *mopts, struct route_in6 *ro, 829 struct ifnet **retifp, struct nhop_object **retnh, u_int fibnum, uint32_t flowid) 830 { 831 MPASS(retifp != NULL); 832 MPASS(retnh != NULL); 833 834 return (selectroute(dstsock, opts, mopts, ro, retifp, 835 retnh, 0, fibnum, flowid)); 836 } 837 838 /* 839 * Default hop limit selection. The precedence is as follows: 840 * 1. Hoplimit value specified via ioctl. 841 * 2. (If the outgoing interface is detected) the current 842 * hop limit of the interface specified by router advertisement. 843 * 3. The system default hoplimit. 844 */ 845 int 846 in6_selecthlim(struct inpcb *inp, struct ifnet *ifp) 847 { 848 849 if (inp && inp->in6p_hops >= 0) 850 return (inp->in6p_hops); 851 else if (ifp) 852 return (ND_IFINFO(ifp)->chlim); 853 else if (inp && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) { 854 struct nhop_object *nh; 855 struct in6_addr dst; 856 uint32_t fibnum, scopeid; 857 int hlim; 858 859 fibnum = inp->inp_inc.inc_fibnum; 860 in6_splitscope(&inp->in6p_faddr, &dst, &scopeid); 861 nh = fib6_lookup(fibnum, &dst, scopeid, 0, 0); 862 if (nh != NULL) { 863 hlim = ND_IFINFO(nh->nh_ifp)->chlim; 864 return (hlim); 865 } 866 } 867 return (V_ip6_defhlim); 868 } 869 870 void 871 addrsel_policy_init(void) 872 { 873 874 init_policy_queue(); 875 876 /* initialize the "last resort" policy */ 877 bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy)); 878 V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; 879 880 if (!IS_DEFAULT_VNET(curvnet)) 881 return; 882 883 ADDRSEL_LOCK_INIT(); 884 ADDRSEL_SXLOCK_INIT(); 885 } 886 887 static struct in6_addrpolicy * 888 lookup_addrsel_policy(struct sockaddr_in6 *key) 889 { 890 struct in6_addrpolicy *match = NULL; 891 892 ADDRSEL_LOCK(); 893 match = match_addrsel_policy(key); 894 895 if (match == NULL) 896 match = &V_defaultaddrpolicy; 897 else 898 match->use++; 899 ADDRSEL_UNLOCK(); 900 901 return (match); 902 } 903 904 /* 905 * Subroutines to manage the address selection policy table via sysctl. 906 */ 907 struct walkarg { 908 struct sysctl_req *w_req; 909 }; 910 911 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); 912 SYSCTL_DECL(_net_inet6_ip6); 913 static SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, 914 CTLFLAG_RD | CTLFLAG_MPSAFE, in6_src_sysctl, 915 ""); 916 917 static int 918 in6_src_sysctl(SYSCTL_HANDLER_ARGS) 919 { 920 struct walkarg w; 921 922 if (req->newptr) 923 return EPERM; 924 925 bzero(&w, sizeof(w)); 926 w.w_req = req; 927 928 return (walk_addrsel_policy(dump_addrsel_policyent, &w)); 929 } 930 931 int 932 in6_src_ioctl(u_long cmd, caddr_t data) 933 { 934 struct in6_addrpolicy ent0; 935 936 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) 937 return (EOPNOTSUPP); /* check for safety */ 938 939 ent0 = *(struct in6_addrpolicy *)data; 940 941 if (ent0.label == ADDR_LABEL_NOTAPP) 942 return (EINVAL); 943 /* check if the prefix mask is consecutive. */ 944 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) 945 return (EINVAL); 946 /* clear trailing garbages (if any) of the prefix address. */ 947 IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr); 948 ent0.use = 0; 949 950 switch (cmd) { 951 case SIOCAADDRCTL_POLICY: 952 return (add_addrsel_policyent(&ent0)); 953 case SIOCDADDRCTL_POLICY: 954 return (delete_addrsel_policyent(&ent0)); 955 } 956 957 return (0); /* XXX: compromise compilers */ 958 } 959 960 /* 961 * The followings are implementation of the policy table using a 962 * simple tail queue. 963 * XXX such details should be hidden. 964 * XXX implementation using binary tree should be more efficient. 965 */ 966 struct addrsel_policyent { 967 TAILQ_ENTRY(addrsel_policyent) ape_entry; 968 struct in6_addrpolicy ape_policy; 969 }; 970 971 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); 972 973 VNET_DEFINE_STATIC(struct addrsel_policyhead, addrsel_policytab); 974 #define V_addrsel_policytab VNET(addrsel_policytab) 975 976 static void 977 init_policy_queue(void) 978 { 979 980 TAILQ_INIT(&V_addrsel_policytab); 981 } 982 983 static int 984 add_addrsel_policyent(struct in6_addrpolicy *newpolicy) 985 { 986 struct addrsel_policyent *new, *pol; 987 988 new = malloc(sizeof(*new), M_IFADDR, 989 M_WAITOK); 990 ADDRSEL_XLOCK(); 991 ADDRSEL_LOCK(); 992 993 /* duplication check */ 994 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 995 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, 996 &pol->ape_policy.addr.sin6_addr) && 997 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, 998 &pol->ape_policy.addrmask.sin6_addr)) { 999 ADDRSEL_UNLOCK(); 1000 ADDRSEL_XUNLOCK(); 1001 free(new, M_IFADDR); 1002 return (EEXIST); /* or override it? */ 1003 } 1004 } 1005 1006 bzero(new, sizeof(*new)); 1007 1008 /* XXX: should validate entry */ 1009 new->ape_policy = *newpolicy; 1010 1011 TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry); 1012 ADDRSEL_UNLOCK(); 1013 ADDRSEL_XUNLOCK(); 1014 1015 return (0); 1016 } 1017 1018 static int 1019 delete_addrsel_policyent(struct in6_addrpolicy *key) 1020 { 1021 struct addrsel_policyent *pol; 1022 1023 ADDRSEL_XLOCK(); 1024 ADDRSEL_LOCK(); 1025 1026 /* search for the entry in the table */ 1027 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1028 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, 1029 &pol->ape_policy.addr.sin6_addr) && 1030 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, 1031 &pol->ape_policy.addrmask.sin6_addr)) { 1032 break; 1033 } 1034 } 1035 if (pol == NULL) { 1036 ADDRSEL_UNLOCK(); 1037 ADDRSEL_XUNLOCK(); 1038 return (ESRCH); 1039 } 1040 1041 TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry); 1042 ADDRSEL_UNLOCK(); 1043 ADDRSEL_XUNLOCK(); 1044 free(pol, M_IFADDR); 1045 1046 return (0); 1047 } 1048 1049 static int 1050 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w) 1051 { 1052 struct addrsel_policyent *pol; 1053 int error = 0; 1054 1055 ADDRSEL_SLOCK(); 1056 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1057 if ((error = (*callback)(&pol->ape_policy, w)) != 0) { 1058 ADDRSEL_SUNLOCK(); 1059 return (error); 1060 } 1061 } 1062 ADDRSEL_SUNLOCK(); 1063 return (error); 1064 } 1065 1066 static int 1067 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) 1068 { 1069 int error = 0; 1070 struct walkarg *w = arg; 1071 1072 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); 1073 1074 return (error); 1075 } 1076 1077 static struct in6_addrpolicy * 1078 match_addrsel_policy(struct sockaddr_in6 *key) 1079 { 1080 struct addrsel_policyent *pent; 1081 struct in6_addrpolicy *bestpol = NULL, *pol; 1082 int matchlen, bestmatchlen = -1; 1083 u_char *mp, *ep, *k, *p, m; 1084 1085 TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) { 1086 matchlen = 0; 1087 1088 pol = &pent->ape_policy; 1089 mp = (u_char *)&pol->addrmask.sin6_addr; 1090 ep = mp + 16; /* XXX: scope field? */ 1091 k = (u_char *)&key->sin6_addr; 1092 p = (u_char *)&pol->addr.sin6_addr; 1093 for (; mp < ep && *mp; mp++, k++, p++) { 1094 m = *mp; 1095 if ((*k & m) != *p) 1096 goto next; /* not match */ 1097 if (m == 0xff) /* short cut for a typical case */ 1098 matchlen += 8; 1099 else { 1100 while (m >= 0x80) { 1101 matchlen++; 1102 m <<= 1; 1103 } 1104 } 1105 } 1106 1107 /* matched. check if this is better than the current best. */ 1108 if (bestpol == NULL || 1109 matchlen > bestmatchlen) { 1110 bestpol = pol; 1111 bestmatchlen = matchlen; 1112 } 1113 1114 next: 1115 continue; 1116 } 1117 1118 return (bestpol); 1119 } 1120