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_fib.h> 109 #include <netinet6/in6_pcb.h> 110 #include <netinet6/ip6_var.h> 111 #include <netinet6/scope6_var.h> 112 #include <netinet6/nd6.h> 113 114 static struct mtx addrsel_lock; 115 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF) 116 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock) 117 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock) 118 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED) 119 120 static struct sx addrsel_sxlock; 121 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock") 122 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock) 123 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock) 124 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock) 125 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock) 126 127 #define ADDR_LABEL_NOTAPP (-1) 128 static VNET_DEFINE(struct in6_addrpolicy, defaultaddrpolicy); 129 #define V_defaultaddrpolicy VNET(defaultaddrpolicy) 130 131 VNET_DEFINE(int, ip6_prefer_tempaddr) = 0; 132 133 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *, 134 struct ip6_moptions *, struct route_in6 *, struct ifnet **, 135 struct rtentry **, int, u_int); 136 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *, 137 struct ip6_moptions *, struct ifnet **, 138 struct ifnet *, u_int); 139 static int in6_selectsrc(uint32_t, struct sockaddr_in6 *, 140 struct ip6_pktopts *, struct inpcb *, struct ucred *, 141 struct ifnet **, struct in6_addr *); 142 143 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *); 144 145 static void init_policy_queue(void); 146 static int add_addrsel_policyent(struct in6_addrpolicy *); 147 static int delete_addrsel_policyent(struct in6_addrpolicy *); 148 static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *), 149 void *); 150 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); 151 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *); 152 153 /* 154 * Return an IPv6 address, which is the most appropriate for a given 155 * destination and user specified options. 156 * If necessary, this function lookups the routing table and returns 157 * an entry to the caller for later use. 158 */ 159 #define REPLACE(r) do {\ 160 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 161 rule = (r); \ 162 /* { \ 163 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 164 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)); \ 165 } */ \ 166 goto replace; \ 167 } while(0) 168 #define NEXT(r) do {\ 169 /* { \ 170 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \ 171 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)); \ 172 } */ \ 173 goto next; /* XXX: we can't use 'continue' here */ \ 174 } while(0) 175 #define BREAK(r) do { \ 176 IP6STAT_INC(ip6s_sources_rule[(r)]); \ 177 rule = (r); \ 178 goto out; /* XXX: we can't use 'break' here */ \ 179 } while(0) 180 181 static int 182 in6_selectsrc(uint32_t fibnum, struct sockaddr_in6 *dstsock, 183 struct ip6_pktopts *opts, struct inpcb *inp, struct ucred *cred, 184 struct ifnet **ifpp, struct in6_addr *srcp) 185 { 186 struct rm_priotracker in6_ifa_tracker; 187 struct in6_addr dst, tmp; 188 struct ifnet *ifp = NULL, *oifp = NULL; 189 struct in6_ifaddr *ia = NULL, *ia_best = NULL; 190 struct in6_pktinfo *pi = NULL; 191 int dst_scope = -1, best_scope = -1, best_matchlen = -1; 192 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL; 193 u_int32_t odstzone; 194 int prefer_tempaddr; 195 int error, rule; 196 struct ip6_moptions *mopts; 197 198 KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__)); 199 200 dst = dstsock->sin6_addr; /* make a copy for local operation */ 201 if (ifpp) { 202 /* 203 * Save a possibly passed in ifp for in6_selectsrc. Only 204 * neighbor discovery code should use this feature, where 205 * we may know the interface but not the FIB number holding 206 * the connected subnet in case someone deleted it from the 207 * default FIB and we need to check the interface. 208 */ 209 if (*ifpp != NULL) 210 oifp = *ifpp; 211 *ifpp = NULL; 212 } 213 214 if (inp != NULL) { 215 INP_LOCK_ASSERT(inp); 216 mopts = inp->in6p_moptions; 217 } else { 218 mopts = NULL; 219 } 220 221 /* 222 * If the source address is explicitly specified by the caller, 223 * check if the requested source address is indeed a unicast address 224 * assigned to the node, and can be used as the packet's source 225 * address. If everything is okay, use the address as source. 226 */ 227 if (opts && (pi = opts->ip6po_pktinfo) && 228 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 229 struct sockaddr_in6 srcsock; 230 struct in6_ifaddr *ia6; 231 232 /* get the outgoing interface */ 233 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp, 234 fibnum)) 235 != 0) 236 return (error); 237 238 /* 239 * determine the appropriate zone id of the source based on 240 * the zone of the destination and the outgoing interface. 241 * If the specified address is ambiguous wrt the scope zone, 242 * the interface must be specified; otherwise, ifa_ifwithaddr() 243 * will fail matching the address. 244 */ 245 bzero(&srcsock, sizeof(srcsock)); 246 srcsock.sin6_family = AF_INET6; 247 srcsock.sin6_len = sizeof(srcsock); 248 srcsock.sin6_addr = pi->ipi6_addr; 249 if (ifp) { 250 error = in6_setscope(&srcsock.sin6_addr, ifp, NULL); 251 if (error) 252 return (error); 253 } 254 if (cred != NULL && (error = prison_local_ip6(cred, 255 &srcsock.sin6_addr, (inp != NULL && 256 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 257 return (error); 258 259 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr( 260 (struct sockaddr *)&srcsock); 261 if (ia6 == NULL || 262 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) { 263 if (ia6 != NULL) 264 ifa_free(&ia6->ia_ifa); 265 return (EADDRNOTAVAIL); 266 } 267 pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */ 268 if (ifpp) 269 *ifpp = ifp; 270 bcopy(&ia6->ia_addr.sin6_addr, srcp, sizeof(*srcp)); 271 ifa_free(&ia6->ia_ifa); 272 return (0); 273 } 274 275 /* 276 * Otherwise, if the socket has already bound the source, just use it. 277 */ 278 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) { 279 if (cred != NULL && 280 (error = prison_local_ip6(cred, &inp->in6p_laddr, 281 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0) 282 return (error); 283 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp)); 284 return (0); 285 } 286 287 /* 288 * Bypass source address selection and use the primary jail IP 289 * if requested. 290 */ 291 if (cred != NULL && !prison_saddrsel_ip6(cred, srcp)) 292 return (0); 293 294 /* 295 * If the address is not specified, choose the best one based on 296 * the outgoing interface and the destination address. 297 */ 298 /* get the outgoing interface */ 299 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp, 300 (inp != NULL) ? inp->inp_inc.inc_fibnum : RT_DEFAULT_FIB)) != 0) 301 return (error); 302 303 #ifdef DIAGNOSTIC 304 if (ifp == NULL) /* this should not happen */ 305 panic("in6_selectsrc: NULL ifp"); 306 #endif 307 error = in6_setscope(&dst, ifp, &odstzone); 308 if (error) 309 return (error); 310 311 rule = 0; 312 IN6_IFADDR_RLOCK(&in6_ifa_tracker); 313 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { 314 int new_scope = -1, new_matchlen = -1; 315 struct in6_addrpolicy *new_policy = NULL; 316 u_int32_t srczone, osrczone, dstzone; 317 struct in6_addr src; 318 struct ifnet *ifp1 = ia->ia_ifp; 319 320 /* 321 * We'll never take an address that breaks the scope zone 322 * of the destination. We also skip an address if its zone 323 * does not contain the outgoing interface. 324 * XXX: we should probably use sin6_scope_id here. 325 */ 326 if (in6_setscope(&dst, ifp1, &dstzone) || 327 odstzone != dstzone) { 328 continue; 329 } 330 src = ia->ia_addr.sin6_addr; 331 if (in6_setscope(&src, ifp, &osrczone) || 332 in6_setscope(&src, ifp1, &srczone) || 333 osrczone != srczone) { 334 continue; 335 } 336 337 /* avoid unusable addresses */ 338 if ((ia->ia6_flags & 339 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) { 340 continue; 341 } 342 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia)) 343 continue; 344 345 /* If jailed only take addresses of the jail into account. */ 346 if (cred != NULL && 347 prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0) 348 continue; 349 350 /* Rule 1: Prefer same address */ 351 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) { 352 ia_best = ia; 353 BREAK(1); /* there should be no better candidate */ 354 } 355 356 if (ia_best == NULL) 357 REPLACE(0); 358 359 /* Rule 2: Prefer appropriate scope */ 360 if (dst_scope < 0) 361 dst_scope = in6_addrscope(&dst); 362 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr); 363 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) { 364 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) 365 REPLACE(2); 366 NEXT(2); 367 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) { 368 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) 369 NEXT(2); 370 REPLACE(2); 371 } 372 373 /* 374 * Rule 3: Avoid deprecated addresses. Note that the case of 375 * !ip6_use_deprecated is already rejected above. 376 */ 377 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia)) 378 NEXT(3); 379 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia)) 380 REPLACE(3); 381 382 /* Rule 4: Prefer home addresses */ 383 /* 384 * XXX: This is a TODO. We should probably merge the MIP6 385 * case above. 386 */ 387 388 /* Rule 5: Prefer outgoing interface */ 389 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) { 390 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) 391 NEXT(5); 392 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) 393 REPLACE(5); 394 } 395 396 /* 397 * Rule 6: Prefer matching label 398 * Note that best_policy should be non-NULL here. 399 */ 400 if (dst_policy == NULL) 401 dst_policy = lookup_addrsel_policy(dstsock); 402 if (dst_policy->label != ADDR_LABEL_NOTAPP) { 403 new_policy = lookup_addrsel_policy(&ia->ia_addr); 404 if (dst_policy->label == best_policy->label && 405 dst_policy->label != new_policy->label) 406 NEXT(6); 407 if (dst_policy->label != best_policy->label && 408 dst_policy->label == new_policy->label) 409 REPLACE(6); 410 } 411 412 /* 413 * Rule 7: Prefer public addresses. 414 * We allow users to reverse the logic by configuring 415 * a sysctl variable, so that privacy conscious users can 416 * always prefer temporary addresses. 417 */ 418 if (opts == NULL || 419 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) { 420 prefer_tempaddr = V_ip6_prefer_tempaddr; 421 } else if (opts->ip6po_prefer_tempaddr == 422 IP6PO_TEMPADDR_NOTPREFER) { 423 prefer_tempaddr = 0; 424 } else 425 prefer_tempaddr = 1; 426 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 427 (ia->ia6_flags & IN6_IFF_TEMPORARY)) { 428 if (prefer_tempaddr) 429 REPLACE(7); 430 else 431 NEXT(7); 432 } 433 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) && 434 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 435 if (prefer_tempaddr) 436 NEXT(7); 437 else 438 REPLACE(7); 439 } 440 441 /* 442 * Rule 8: prefer addresses on alive interfaces. 443 * This is a KAME specific rule. 444 */ 445 if ((ia_best->ia_ifp->if_flags & IFF_UP) && 446 !(ia->ia_ifp->if_flags & IFF_UP)) 447 NEXT(8); 448 if (!(ia_best->ia_ifp->if_flags & IFF_UP) && 449 (ia->ia_ifp->if_flags & IFF_UP)) 450 REPLACE(8); 451 452 /* 453 * Rule 9: prefer address with better virtual status. 454 */ 455 if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa)) 456 REPLACE(9); 457 if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa)) 458 NEXT(9); 459 460 /* 461 * Rule 10: prefer address with `prefer_source' flag. 462 */ 463 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 && 464 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0) 465 REPLACE(10); 466 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 && 467 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0) 468 NEXT(10); 469 470 /* 471 * Rule 14: Use longest matching prefix. 472 * Note: in the address selection draft, this rule is 473 * documented as "Rule 8". However, since it is also 474 * documented that this rule can be overridden, we assign 475 * a large number so that it is easy to assign smaller numbers 476 * to more preferred rules. 477 */ 478 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst); 479 if (best_matchlen < new_matchlen) 480 REPLACE(14); 481 if (new_matchlen < best_matchlen) 482 NEXT(14); 483 484 /* Rule 15 is reserved. */ 485 486 /* 487 * Last resort: just keep the current candidate. 488 * Or, do we need more rules? 489 */ 490 continue; 491 492 replace: 493 ia_best = ia; 494 best_scope = (new_scope >= 0 ? new_scope : 495 in6_addrscope(&ia_best->ia_addr.sin6_addr)); 496 best_policy = (new_policy ? new_policy : 497 lookup_addrsel_policy(&ia_best->ia_addr)); 498 best_matchlen = (new_matchlen >= 0 ? new_matchlen : 499 in6_matchlen(&ia_best->ia_addr.sin6_addr, 500 &dst)); 501 502 next: 503 continue; 504 505 out: 506 break; 507 } 508 509 if ((ia = ia_best) == NULL) { 510 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 511 IP6STAT_INC(ip6s_sources_none); 512 return (EADDRNOTAVAIL); 513 } 514 515 /* 516 * At this point at least one of the addresses belonged to the jail 517 * but it could still be, that we want to further restrict it, e.g. 518 * theoratically IN6_IS_ADDR_LOOPBACK. 519 * It must not be IN6_IS_ADDR_UNSPECIFIED anymore. 520 * prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should 521 * let all others previously selected pass. 522 * Use tmp to not change ::1 on lo0 to the primary jail address. 523 */ 524 tmp = ia->ia_addr.sin6_addr; 525 if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL && 526 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) { 527 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 528 IP6STAT_INC(ip6s_sources_none); 529 return (EADDRNOTAVAIL); 530 } 531 532 if (ifpp) 533 *ifpp = ifp; 534 535 bcopy(&tmp, srcp, sizeof(*srcp)); 536 if (ia->ia_ifp == ifp) 537 IP6STAT_INC(ip6s_sources_sameif[best_scope]); 538 else 539 IP6STAT_INC(ip6s_sources_otherif[best_scope]); 540 if (dst_scope == best_scope) 541 IP6STAT_INC(ip6s_sources_samescope[best_scope]); 542 else 543 IP6STAT_INC(ip6s_sources_otherscope[best_scope]); 544 if (IFA6_IS_DEPRECATED(ia)) 545 IP6STAT_INC(ip6s_sources_deprecated[best_scope]); 546 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); 547 return (0); 548 } 549 550 /* 551 * Select source address based on @inp, @dstsock and @opts. 552 * Stores selected address to @srcp. If @scope_ambiguous is set, 553 * embed scope from selected outgoing interface. If @hlim pointer 554 * is provided, stores calculated hop limit there. 555 * Returns 0 on success. 556 */ 557 int 558 in6_selectsrc_socket(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 559 struct inpcb *inp, struct ucred *cred, int scope_ambiguous, 560 struct in6_addr *srcp, int *hlim) 561 { 562 struct ifnet *retifp; 563 uint32_t fibnum; 564 int error; 565 566 fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : RT_DEFAULT_FIB; 567 retifp = NULL; 568 569 error = in6_selectsrc(fibnum, dstsock, opts, inp, cred, &retifp, srcp); 570 if (error != 0) 571 return (error); 572 573 if (hlim != NULL) 574 *hlim = in6_selecthlim(inp, retifp); 575 576 if (retifp == NULL || scope_ambiguous == 0) 577 return (0); 578 579 /* 580 * Application should provide a proper zone ID or the use of 581 * default zone IDs should be enabled. Unfortunately, some 582 * applications do not behave as it should, so we need a 583 * workaround. Even if an appropriate ID is not determined 584 * (when it's required), if we can determine the outgoing 585 * interface. determine the zone ID based on the interface. 586 */ 587 error = in6_setscope(&dstsock->sin6_addr, retifp, NULL); 588 589 return (error); 590 } 591 592 /* 593 * Select source address based on @fibnum, @dst and @scopeid. 594 * Stores selected address to @srcp. 595 * Returns 0 on success. 596 * 597 * Used by non-socket based consumers (ND code mostly) 598 */ 599 int 600 in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst, 601 uint32_t scopeid, struct ifnet *ifp, struct in6_addr *srcp, 602 int *hlim) 603 { 604 struct ifnet *retifp; 605 struct sockaddr_in6 dst_sa; 606 int error; 607 608 retifp = ifp; 609 bzero(&dst_sa, sizeof(dst_sa)); 610 dst_sa.sin6_family = AF_INET6; 611 dst_sa.sin6_len = sizeof(dst_sa); 612 dst_sa.sin6_addr = *dst; 613 dst_sa.sin6_scope_id = scopeid; 614 sa6_embedscope(&dst_sa, 0); 615 616 error = in6_selectsrc(fibnum, &dst_sa, NULL, NULL, NULL, &retifp, srcp); 617 if (hlim != NULL) 618 *hlim = in6_selecthlim(NULL, retifp); 619 620 return (error); 621 } 622 623 /* 624 * clone - meaningful only for bsdi and freebsd 625 */ 626 static int 627 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 628 struct ip6_moptions *mopts, struct route_in6 *ro, 629 struct ifnet **retifp, struct rtentry **retrt, int norouteok, u_int fibnum) 630 { 631 int error = 0; 632 struct ifnet *ifp = NULL; 633 struct rtentry *rt = NULL; 634 struct sockaddr_in6 *sin6_next; 635 struct in6_pktinfo *pi = NULL; 636 struct in6_addr *dst = &dstsock->sin6_addr; 637 uint32_t zoneid; 638 #if 0 639 char ip6buf[INET6_ADDRSTRLEN]; 640 641 if (dstsock->sin6_addr.s6_addr32[0] == 0 && 642 dstsock->sin6_addr.s6_addr32[1] == 0 && 643 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) { 644 printf("in6_selectroute: strange destination %s\n", 645 ip6_sprintf(ip6buf, &dstsock->sin6_addr)); 646 } else { 647 printf("in6_selectroute: destination = %s%%%d\n", 648 ip6_sprintf(ip6buf, &dstsock->sin6_addr), 649 dstsock->sin6_scope_id); /* for debug */ 650 } 651 #endif 652 653 /* If the caller specify the outgoing interface explicitly, use it. */ 654 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) { 655 /* XXX boundary check is assumed to be already done. */ 656 ifp = ifnet_byindex(pi->ipi6_ifindex); 657 if (ifp != NULL && 658 (norouteok || retrt == NULL || 659 IN6_IS_ADDR_MULTICAST(dst))) { 660 /* 661 * we do not have to check or get the route for 662 * multicast. 663 */ 664 goto done; 665 } else 666 goto getroute; 667 } 668 /* 669 * If the destination address is a multicast address and the outgoing 670 * interface for the address is specified by the caller, use it. 671 */ 672 if (IN6_IS_ADDR_MULTICAST(dst) && 673 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) { 674 goto done; /* we do not need a route for multicast. */ 675 } 676 /* 677 * If destination address is LLA or link- or node-local multicast, 678 * use it's embedded scope zone id to determine outgoing interface. 679 */ 680 if (IN6_IS_ADDR_MC_LINKLOCAL(dst) || 681 IN6_IS_ADDR_MC_NODELOCAL(dst)) { 682 zoneid = ntohs(in6_getscope(dst)); 683 if (zoneid > 0) { 684 ifp = in6_getlinkifnet(zoneid); 685 goto done; 686 } 687 } 688 689 getroute: 690 /* 691 * If the next hop address for the packet is specified by the caller, 692 * use it as the gateway. 693 */ 694 if (opts && opts->ip6po_nexthop) { 695 struct route_in6 *ron; 696 697 sin6_next = satosin6(opts->ip6po_nexthop); 698 if (IN6_IS_ADDR_LINKLOCAL(&sin6_next->sin6_addr)) { 699 /* 700 * Next hop is LLA, thus it should be neighbor. 701 * Determine outgoing interface by zone index. 702 */ 703 zoneid = ntohs(in6_getscope(&sin6_next->sin6_addr)); 704 if (zoneid > 0) { 705 ifp = in6_getlinkifnet(zoneid); 706 goto done; 707 } 708 } 709 ron = &opts->ip6po_nextroute; 710 /* Use a cached route if it exists and is valid. */ 711 if (ron->ro_rt != NULL && ( 712 (ron->ro_rt->rt_flags & RTF_UP) == 0 || 713 ron->ro_dst.sin6_family != AF_INET6 || 714 !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr, 715 &sin6_next->sin6_addr))) 716 RO_RTFREE(ron); 717 if (ron->ro_rt == NULL) { 718 ron->ro_dst = *sin6_next; 719 in6_rtalloc(ron, fibnum); /* multi path case? */ 720 } 721 /* 722 * The node identified by that address must be a 723 * neighbor of the sending host. 724 */ 725 if (ron->ro_rt == NULL || 726 (ron->ro_rt->rt_flags & RTF_GATEWAY) != 0) 727 error = EHOSTUNREACH; 728 goto done; 729 } 730 731 /* 732 * Use a cached route if it exists and is valid, else try to allocate 733 * a new one. Note that we should check the address family of the 734 * cached destination, in case of sharing the cache with IPv4. 735 */ 736 if (ro) { 737 if (ro->ro_rt && 738 (!(ro->ro_rt->rt_flags & RTF_UP) || 739 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 || 740 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 741 dst))) { 742 RTFREE(ro->ro_rt); 743 ro->ro_rt = (struct rtentry *)NULL; 744 } 745 if (ro->ro_rt == (struct rtentry *)NULL) { 746 struct sockaddr_in6 *sa6; 747 748 /* No route yet, so try to acquire one */ 749 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 750 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 751 *sa6 = *dstsock; 752 sa6->sin6_scope_id = 0; 753 754 #ifdef RADIX_MPATH 755 rtalloc_mpath_fib((struct route *)ro, 756 ntohl(sa6->sin6_addr.s6_addr32[3]), fibnum); 757 #else 758 ro->ro_rt = in6_rtalloc1((struct sockaddr *) 759 &ro->ro_dst, 0, 0UL, fibnum); 760 if (ro->ro_rt) 761 RT_UNLOCK(ro->ro_rt); 762 #endif 763 } 764 765 /* 766 * do not care about the result if we have the nexthop 767 * explicitly specified. 768 */ 769 if (opts && opts->ip6po_nexthop) 770 goto done; 771 772 if (ro->ro_rt) { 773 ifp = ro->ro_rt->rt_ifp; 774 775 if (ifp == NULL) { /* can this really happen? */ 776 RTFREE(ro->ro_rt); 777 ro->ro_rt = NULL; 778 } 779 } 780 if (ro->ro_rt == NULL) 781 error = EHOSTUNREACH; 782 rt = ro->ro_rt; 783 784 /* 785 * Check if the outgoing interface conflicts with 786 * the interface specified by ipi6_ifindex (if specified). 787 * Note that loopback interface is always okay. 788 * (this may happen when we are sending a packet to one of 789 * our own addresses.) 790 */ 791 if (ifp && opts && opts->ip6po_pktinfo && 792 opts->ip6po_pktinfo->ipi6_ifindex) { 793 if (!(ifp->if_flags & IFF_LOOPBACK) && 794 ifp->if_index != 795 opts->ip6po_pktinfo->ipi6_ifindex) { 796 error = EHOSTUNREACH; 797 goto done; 798 } 799 } 800 } 801 802 done: 803 if (ifp == NULL && rt == NULL) { 804 /* 805 * This can happen if the caller did not pass a cached route 806 * nor any other hints. We treat this case an error. 807 */ 808 error = EHOSTUNREACH; 809 } 810 if (error == EHOSTUNREACH) 811 IP6STAT_INC(ip6s_noroute); 812 813 if (retifp != NULL) { 814 *retifp = ifp; 815 816 /* 817 * Adjust the "outgoing" interface. If we're going to loop 818 * the packet back to ourselves, the ifp would be the loopback 819 * interface. However, we'd rather know the interface associated 820 * to the destination address (which should probably be one of 821 * our own addresses.) 822 */ 823 if (rt) { 824 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) && 825 (rt->rt_gateway->sa_family == AF_LINK)) 826 *retifp = 827 ifnet_byindex(((struct sockaddr_dl *) 828 rt->rt_gateway)->sdl_index); 829 } 830 } 831 832 if (retrt != NULL) 833 *retrt = rt; /* rt may be NULL */ 834 835 return (error); 836 } 837 838 static int 839 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 840 struct ip6_moptions *mopts, struct ifnet **retifp, 841 struct ifnet *oifp, u_int fibnum) 842 { 843 int error; 844 struct route_in6 sro; 845 struct rtentry *rt = NULL; 846 int rt_flags; 847 848 KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__)); 849 850 bzero(&sro, sizeof(sro)); 851 rt_flags = 0; 852 853 error = selectroute(dstsock, opts, mopts, &sro, retifp, &rt, 1, fibnum); 854 855 if (rt) 856 rt_flags = rt->rt_flags; 857 if (rt && rt == sro.ro_rt) 858 RTFREE(rt); 859 860 if (error != 0) { 861 /* Help ND. See oifp comment in in6_selectsrc(). */ 862 if (oifp != NULL && fibnum == RT_DEFAULT_FIB) { 863 *retifp = oifp; 864 error = 0; 865 } 866 return (error); 867 } 868 869 /* 870 * do not use a rejected or black hole route. 871 * XXX: this check should be done in the L2 output routine. 872 * However, if we skipped this check here, we'd see the following 873 * scenario: 874 * - install a rejected route for a scoped address prefix 875 * (like fe80::/10) 876 * - send a packet to a destination that matches the scoped prefix, 877 * with ambiguity about the scope zone. 878 * - pick the outgoing interface from the route, and disambiguate the 879 * scope zone with the interface. 880 * - ip6_output() would try to get another route with the "new" 881 * destination, which may be valid. 882 * - we'd see no error on output. 883 * Although this may not be very harmful, it should still be confusing. 884 * We thus reject the case here. 885 */ 886 887 if (rt_flags & (RTF_REJECT | RTF_BLACKHOLE)) { 888 error = (rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 889 return (error); 890 } 891 892 return (0); 893 } 894 895 /* 896 * Public wrapper function to selectroute(). 897 * 898 * XXX-BZ in6_selectroute() should and will grow the FIB argument. The 899 * in6_selectroute_fib() function is only there for backward compat on stable. 900 */ 901 int 902 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 903 struct ip6_moptions *mopts, struct route_in6 *ro, 904 struct ifnet **retifp, struct rtentry **retrt) 905 { 906 907 return (selectroute(dstsock, opts, mopts, ro, retifp, 908 retrt, 0, RT_DEFAULT_FIB)); 909 } 910 911 #ifndef BURN_BRIDGES 912 int 913 in6_selectroute_fib(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 914 struct ip6_moptions *mopts, struct route_in6 *ro, 915 struct ifnet **retifp, struct rtentry **retrt, u_int fibnum) 916 { 917 918 return (selectroute(dstsock, opts, mopts, ro, retifp, 919 retrt, 0, fibnum)); 920 } 921 #endif 922 923 /* 924 * Default hop limit selection. The precedence is as follows: 925 * 1. Hoplimit value specified via ioctl. 926 * 2. (If the outgoing interface is detected) the current 927 * hop limit of the interface specified by router advertisement. 928 * 3. The system default hoplimit. 929 */ 930 int 931 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp) 932 { 933 934 if (in6p && in6p->in6p_hops >= 0) 935 return (in6p->in6p_hops); 936 else if (ifp) 937 return (ND_IFINFO(ifp)->chlim); 938 else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) { 939 struct nhop6_basic nh6; 940 struct in6_addr dst; 941 uint32_t fibnum, scopeid; 942 int hlim; 943 944 fibnum = in6p->inp_inc.inc_fibnum; 945 in6_splitscope(&in6p->in6p_faddr, &dst, &scopeid); 946 if (fib6_lookup_nh_basic(fibnum, &dst, scopeid, 0, 0, &nh6)==0){ 947 hlim = ND_IFINFO(nh6.nh_ifp)->chlim; 948 return (hlim); 949 } 950 } 951 return (V_ip6_defhlim); 952 } 953 954 /* 955 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 956 * share this function by all *bsd*... 957 */ 958 int 959 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred) 960 { 961 struct socket *so = inp->inp_socket; 962 u_int16_t lport = 0; 963 int error, lookupflags = 0; 964 #ifdef INVARIANTS 965 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 966 #endif 967 968 INP_WLOCK_ASSERT(inp); 969 INP_HASH_WLOCK_ASSERT(pcbinfo); 970 971 error = prison_local_ip6(cred, laddr, 972 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)); 973 if (error) 974 return(error); 975 976 /* XXX: this is redundant when called from in6_pcbbind */ 977 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 978 lookupflags = INPLOOKUP_WILDCARD; 979 980 inp->inp_flags |= INP_ANONPORT; 981 982 error = in_pcb_lport(inp, NULL, &lport, cred, lookupflags); 983 if (error != 0) 984 return (error); 985 986 inp->inp_lport = lport; 987 if (in_pcbinshash(inp) != 0) { 988 inp->in6p_laddr = in6addr_any; 989 inp->inp_lport = 0; 990 return (EAGAIN); 991 } 992 993 return (0); 994 } 995 996 void 997 addrsel_policy_init(void) 998 { 999 1000 init_policy_queue(); 1001 1002 /* initialize the "last resort" policy */ 1003 bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy)); 1004 V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; 1005 1006 if (!IS_DEFAULT_VNET(curvnet)) 1007 return; 1008 1009 ADDRSEL_LOCK_INIT(); 1010 ADDRSEL_SXLOCK_INIT(); 1011 } 1012 1013 static struct in6_addrpolicy * 1014 lookup_addrsel_policy(struct sockaddr_in6 *key) 1015 { 1016 struct in6_addrpolicy *match = NULL; 1017 1018 ADDRSEL_LOCK(); 1019 match = match_addrsel_policy(key); 1020 1021 if (match == NULL) 1022 match = &V_defaultaddrpolicy; 1023 else 1024 match->use++; 1025 ADDRSEL_UNLOCK(); 1026 1027 return (match); 1028 } 1029 1030 /* 1031 * Subroutines to manage the address selection policy table via sysctl. 1032 */ 1033 struct walkarg { 1034 struct sysctl_req *w_req; 1035 }; 1036 1037 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); 1038 SYSCTL_DECL(_net_inet6_ip6); 1039 static SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, 1040 CTLFLAG_RD, in6_src_sysctl, ""); 1041 1042 static int 1043 in6_src_sysctl(SYSCTL_HANDLER_ARGS) 1044 { 1045 struct walkarg w; 1046 1047 if (req->newptr) 1048 return EPERM; 1049 1050 bzero(&w, sizeof(w)); 1051 w.w_req = req; 1052 1053 return (walk_addrsel_policy(dump_addrsel_policyent, &w)); 1054 } 1055 1056 int 1057 in6_src_ioctl(u_long cmd, caddr_t data) 1058 { 1059 struct in6_addrpolicy ent0; 1060 1061 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) 1062 return (EOPNOTSUPP); /* check for safety */ 1063 1064 ent0 = *(struct in6_addrpolicy *)data; 1065 1066 if (ent0.label == ADDR_LABEL_NOTAPP) 1067 return (EINVAL); 1068 /* check if the prefix mask is consecutive. */ 1069 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) 1070 return (EINVAL); 1071 /* clear trailing garbages (if any) of the prefix address. */ 1072 IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr); 1073 ent0.use = 0; 1074 1075 switch (cmd) { 1076 case SIOCAADDRCTL_POLICY: 1077 return (add_addrsel_policyent(&ent0)); 1078 case SIOCDADDRCTL_POLICY: 1079 return (delete_addrsel_policyent(&ent0)); 1080 } 1081 1082 return (0); /* XXX: compromise compilers */ 1083 } 1084 1085 /* 1086 * The followings are implementation of the policy table using a 1087 * simple tail queue. 1088 * XXX such details should be hidden. 1089 * XXX implementation using binary tree should be more efficient. 1090 */ 1091 struct addrsel_policyent { 1092 TAILQ_ENTRY(addrsel_policyent) ape_entry; 1093 struct in6_addrpolicy ape_policy; 1094 }; 1095 1096 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); 1097 1098 static VNET_DEFINE(struct addrsel_policyhead, addrsel_policytab); 1099 #define V_addrsel_policytab VNET(addrsel_policytab) 1100 1101 static void 1102 init_policy_queue(void) 1103 { 1104 1105 TAILQ_INIT(&V_addrsel_policytab); 1106 } 1107 1108 static int 1109 add_addrsel_policyent(struct in6_addrpolicy *newpolicy) 1110 { 1111 struct addrsel_policyent *new, *pol; 1112 1113 new = malloc(sizeof(*new), M_IFADDR, 1114 M_WAITOK); 1115 ADDRSEL_XLOCK(); 1116 ADDRSEL_LOCK(); 1117 1118 /* duplication check */ 1119 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1120 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr, 1121 &pol->ape_policy.addr.sin6_addr) && 1122 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr, 1123 &pol->ape_policy.addrmask.sin6_addr)) { 1124 ADDRSEL_UNLOCK(); 1125 ADDRSEL_XUNLOCK(); 1126 free(new, M_IFADDR); 1127 return (EEXIST); /* or override it? */ 1128 } 1129 } 1130 1131 bzero(new, sizeof(*new)); 1132 1133 /* XXX: should validate entry */ 1134 new->ape_policy = *newpolicy; 1135 1136 TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry); 1137 ADDRSEL_UNLOCK(); 1138 ADDRSEL_XUNLOCK(); 1139 1140 return (0); 1141 } 1142 1143 static int 1144 delete_addrsel_policyent(struct in6_addrpolicy *key) 1145 { 1146 struct addrsel_policyent *pol; 1147 1148 ADDRSEL_XLOCK(); 1149 ADDRSEL_LOCK(); 1150 1151 /* search for the entry in the table */ 1152 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1153 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr, 1154 &pol->ape_policy.addr.sin6_addr) && 1155 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr, 1156 &pol->ape_policy.addrmask.sin6_addr)) { 1157 break; 1158 } 1159 } 1160 if (pol == NULL) { 1161 ADDRSEL_UNLOCK(); 1162 ADDRSEL_XUNLOCK(); 1163 return (ESRCH); 1164 } 1165 1166 TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry); 1167 ADDRSEL_UNLOCK(); 1168 ADDRSEL_XUNLOCK(); 1169 free(pol, M_IFADDR); 1170 1171 return (0); 1172 } 1173 1174 static int 1175 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w) 1176 { 1177 struct addrsel_policyent *pol; 1178 int error = 0; 1179 1180 ADDRSEL_SLOCK(); 1181 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) { 1182 if ((error = (*callback)(&pol->ape_policy, w)) != 0) { 1183 ADDRSEL_SUNLOCK(); 1184 return (error); 1185 } 1186 } 1187 ADDRSEL_SUNLOCK(); 1188 return (error); 1189 } 1190 1191 static int 1192 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) 1193 { 1194 int error = 0; 1195 struct walkarg *w = arg; 1196 1197 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); 1198 1199 return (error); 1200 } 1201 1202 static struct in6_addrpolicy * 1203 match_addrsel_policy(struct sockaddr_in6 *key) 1204 { 1205 struct addrsel_policyent *pent; 1206 struct in6_addrpolicy *bestpol = NULL, *pol; 1207 int matchlen, bestmatchlen = -1; 1208 u_char *mp, *ep, *k, *p, m; 1209 1210 TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) { 1211 matchlen = 0; 1212 1213 pol = &pent->ape_policy; 1214 mp = (u_char *)&pol->addrmask.sin6_addr; 1215 ep = mp + 16; /* XXX: scope field? */ 1216 k = (u_char *)&key->sin6_addr; 1217 p = (u_char *)&pol->addr.sin6_addr; 1218 for (; mp < ep && *mp; mp++, k++, p++) { 1219 m = *mp; 1220 if ((*k & m) != *p) 1221 goto next; /* not match */ 1222 if (m == 0xff) /* short cut for a typical case */ 1223 matchlen += 8; 1224 else { 1225 while (m >= 0x80) { 1226 matchlen++; 1227 m <<= 1; 1228 } 1229 } 1230 } 1231 1232 /* matched. check if this is better than the current best. */ 1233 if (bestpol == NULL || 1234 matchlen > bestmatchlen) { 1235 bestpol = pol; 1236 bestmatchlen = matchlen; 1237 } 1238 1239 next: 1240 continue; 1241 } 1242 1243 return (bestpol); 1244 } 1245