name6.c revision 245225
1/* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 itojun Exp $ */ 2 3/* 4 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 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/* 32 * ++Copyright++ 1985, 1988, 1993 33 * - 34 * Copyright (c) 1985, 1988, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * - 65 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 66 * 67 * Permission to use, copy, modify, and distribute this software for any 68 * purpose with or without fee is hereby granted, provided that the above 69 * copyright notice and this permission notice appear in all copies, and that 70 * the name of Digital Equipment Corporation not be used in advertising or 71 * publicity pertaining to distribution of the document or software without 72 * specific, written prior permission. 73 * 74 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 75 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 76 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 77 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 78 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 79 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 80 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 81 * SOFTWARE. 82 * - 83 * --Copyright-- 84 */ 85 86/* 87 * Atsushi Onoe <onoe@sm.sony.co.jp> 88 */ 89 90#include <sys/cdefs.h> 91__FBSDID("$FreeBSD: head/lib/libc/net/name6.c 245225 2013-01-09 15:22:37Z ume $"); 92 93#include "namespace.h" 94#include <sys/param.h> 95#include <sys/socket.h> 96#include <sys/time.h> 97#include <sys/queue.h> 98#include <netinet/in.h> 99#ifdef INET6 100#include <net/if.h> 101#include <net/if_var.h> 102#include <sys/sysctl.h> 103#include <sys/ioctl.h> 104#include <netinet6/in6_var.h> /* XXX */ 105#endif 106 107#include <arpa/inet.h> 108#include <arpa/nameser.h> 109 110#include <errno.h> 111#include <netdb.h> 112#include <resolv.h> 113#include <stdio.h> 114#include <stdlib.h> 115#include <string.h> 116#include <stdarg.h> 117#include <nsswitch.h> 118#include <unistd.h> 119#include "un-namespace.h" 120#include "netdb_private.h" 121#include "res_private.h" 122 123#ifndef MAXALIASES 124#define MAXALIASES 10 125#endif 126#ifndef MAXADDRS 127#define MAXADDRS 20 128#endif 129#ifndef MAXDNAME 130#define MAXDNAME 1025 131#endif 132 133#ifdef INET6 134#define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 135 sizeof(struct in_addr)) 136#else 137#define ADDRLEN(af) sizeof(struct in_addr) 138#endif 139 140#define MAPADDR(ab, ina) \ 141do { \ 142 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 143 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 144 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 145} while (0) 146#define MAPADDRENABLED(flags) \ 147 (((flags) & AI_V4MAPPED) || \ 148 (((flags) & AI_V4MAPPED_CFG))) 149 150union inx_addr { 151 struct in_addr in_addr; 152#ifdef INET6 153 struct in6_addr in6_addr; 154#endif 155 struct { 156 u_char mau_zero[10]; 157 u_char mau_one[2]; 158 struct in_addr mau_inaddr; 159 } map_addr_un; 160#define map_zero map_addr_un.mau_zero 161#define map_one map_addr_un.mau_one 162#define map_inaddr map_addr_un.mau_inaddr 163}; 164 165struct policyqueue { 166 TAILQ_ENTRY(policyqueue) pc_entry; 167#ifdef INET6 168 struct in6_addrpolicy pc_policy; 169#endif 170}; 171TAILQ_HEAD(policyhead, policyqueue); 172 173#define AIO_SRCFLAG_DEPRECATED 0x1 174 175struct hp_order { 176 union { 177 struct sockaddr_storage aiou_ss; 178 struct sockaddr aiou_sa; 179 } aio_src_un; 180#define aio_srcsa aio_src_un.aiou_sa 181 u_int32_t aio_srcflag; 182 int aio_srcscope; 183 int aio_dstscope; 184 struct policyqueue *aio_srcpolicy; 185 struct policyqueue *aio_dstpolicy; 186 union { 187 struct sockaddr_storage aiou_ss; 188 struct sockaddr aiou_sa; 189 } aio_un; 190#define aio_sa aio_un.aiou_sa 191 int aio_matchlen; 192 char *aio_h_addr; 193}; 194 195static struct hostent *_hpcopy(struct hostent *, int *); 196static struct hostent *_hpaddr(int, const char *, void *, int *); 197#ifdef INET6 198static struct hostent *_hpmerge(struct hostent *, struct hostent *, int *); 199static struct hostent *_hpmapv6(struct hostent *, int *); 200#endif 201static struct hostent *_hpsort(struct hostent *, res_state); 202 203#ifdef ENABLE_IP6ADDRCTL 204static struct hostent *_hpreorder(struct hostent *); 205static int get_addrselectpolicy(struct policyhead *); 206static void free_addrselectpolicy(struct policyhead *); 207static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 208 struct policyhead *); 209static void set_source(struct hp_order *, struct policyhead *); 210static int matchlen(struct sockaddr *, struct sockaddr *); 211static int comp_dst(const void *, const void *); 212static int gai_addr2scopetype(struct sockaddr *); 213#endif 214 215/* 216 * Functions defined in RFC2553 217 * getipnodebyname, getipnodebyaddr, freehostent 218 */ 219 220struct hostent * 221getipnodebyname(const char *name, int af, int flags, int *errp) 222{ 223 struct hostent *hp; 224 union inx_addr addrbuf; 225 res_state statp; 226 u_long options; 227 228 switch (af) { 229 case AF_INET: 230#ifdef INET6 231 case AF_INET6: 232#endif 233 break; 234 default: 235 *errp = NO_RECOVERY; 236 return NULL; 237 } 238 239 if (flags & AI_ADDRCONFIG) { 240 int s; 241 242 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 243 return NULL; 244 /* 245 * TODO: 246 * Note that implementation dependent test for address 247 * configuration should be done everytime called 248 * (or apropriate interval), 249 * because addresses will be dynamically assigned or deleted. 250 */ 251 _close(s); 252 } 253 254#ifdef INET6 255 /* special case for literal address */ 256 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 257 if (af != AF_INET6) { 258 *errp = HOST_NOT_FOUND; 259 return NULL; 260 } 261 return _hpaddr(af, name, &addrbuf, errp); 262 } 263#endif 264 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 265 if (af != AF_INET) { 266 if (MAPADDRENABLED(flags)) { 267 MAPADDR(&addrbuf, &addrbuf.in_addr); 268 } else { 269 *errp = HOST_NOT_FOUND; 270 return NULL; 271 } 272 } 273 return _hpaddr(af, name, &addrbuf, errp); 274 } 275 276 277 statp = __res_state(); 278 if ((statp->options & RES_INIT) == 0) { 279 if (res_ninit(statp) < 0) { 280 *errp = NETDB_INTERNAL; 281 return NULL; 282 } 283 } 284 285 options = statp->options; 286 statp->options &= ~RES_USE_INET6; 287 288 hp = gethostbyname2(name, af); 289 hp = _hpcopy(hp, errp); 290 291#ifdef INET6 292 if (af == AF_INET6 && ((flags & AI_ALL) || hp == NULL) && 293 MAPADDRENABLED(flags)) { 294 struct hostent *hp2 = gethostbyname2(name, AF_INET); 295 if (hp == NULL) 296 if (hp2 == NULL) 297 *errp = statp->res_h_errno; 298 else 299 hp = _hpmapv6(hp2, errp); 300 else { 301 if (hp2 && strcmp(hp->h_name, hp2->h_name) == 0) { 302 struct hostent *hpb = hp; 303 hp = _hpmerge(hpb, hp2, errp); 304 freehostent(hpb); 305 } 306 } 307 } 308#endif 309 310 if (hp == NULL) 311 *errp = statp->res_h_errno; 312 313 statp->options = options; 314#ifdef ENABLE_IP6ADDRCTL 315 return _hpreorder(_hpsort(hp, statp)); 316#else 317 return _hpsort(hp, statp); 318#endif 319} 320 321struct hostent * 322getipnodebyaddr(const void *src, size_t len, int af, int *errp) 323{ 324 struct hostent *hp; 325 res_state statp; 326 u_long options; 327 328#ifdef INET6 329 struct in6_addr addrbuf; 330#else 331 struct in_addr addrbuf; 332#endif 333 334 switch (af) { 335 case AF_INET: 336 if (len != sizeof(struct in_addr)) { 337 *errp = NO_RECOVERY; 338 return NULL; 339 } 340 if ((long)src & ~(sizeof(struct in_addr) - 1)) { 341 memcpy(&addrbuf, src, len); 342 src = &addrbuf; 343 } 344 if (((struct in_addr *)src)->s_addr == 0) 345 return NULL; 346 break; 347#ifdef INET6 348 case AF_INET6: 349 if (len != sizeof(struct in6_addr)) { 350 *errp = NO_RECOVERY; 351 return NULL; 352 } 353 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 354 memcpy(&addrbuf, src, len); 355 src = &addrbuf; 356 } 357 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 358 return NULL; 359 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 360 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 361 src = (char *)src + 362 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 363 af = AF_INET; 364 len = sizeof(struct in_addr); 365 } 366 break; 367#endif 368 default: 369 *errp = NO_RECOVERY; 370 return NULL; 371 } 372 373 statp = __res_state(); 374 if ((statp->options & RES_INIT) == 0) { 375 if (res_ninit(statp) < 0) { 376 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 377 return NULL; 378 } 379 } 380 381 options = statp->options; 382 statp->options &= ~RES_USE_INET6; 383 384 hp = gethostbyaddr(src, len, af); 385 if (hp == NULL) 386 *errp = statp->res_h_errno; 387 388 statp->options = options; 389 return (_hpcopy(hp, errp)); 390} 391 392void 393freehostent(struct hostent *ptr) 394{ 395 free(ptr); 396} 397 398/* 399 * Private utility functions 400 */ 401 402/* 403 * _hpcopy: allocate and copy hostent structure 404 */ 405static struct hostent * 406_hpcopy(struct hostent *hp, int *errp) 407{ 408 struct hostent *nhp; 409 char *cp, **pp; 410 int size, addrsize; 411 int nalias = 0, naddr = 0; 412 int al_off; 413 int i; 414 415 if (hp == NULL) 416 return hp; 417 418 /* count size to be allocated */ 419 size = sizeof(struct hostent); 420 if (hp->h_name != NULL) 421 size += strlen(hp->h_name) + 1; 422 if ((pp = hp->h_aliases) != NULL) { 423 for (i = 0; *pp != NULL; i++, pp++) { 424 if (**pp != '\0') { 425 size += strlen(*pp) + 1; 426 nalias++; 427 } 428 } 429 } 430 /* adjust alignment */ 431 size = ALIGN(size); 432 al_off = size; 433 size += sizeof(char *) * (nalias + 1); 434 addrsize = ALIGN(hp->h_length); 435 if ((pp = hp->h_addr_list) != NULL) { 436 while (*pp++ != NULL) 437 naddr++; 438 } 439 size += addrsize * naddr; 440 size += sizeof(char *) * (naddr + 1); 441 442 /* copy */ 443 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 444 *errp = TRY_AGAIN; 445 return NULL; 446 } 447 cp = (char *)&nhp[1]; 448 if (hp->h_name != NULL) { 449 nhp->h_name = cp; 450 strcpy(cp, hp->h_name); 451 cp += strlen(cp) + 1; 452 } else 453 nhp->h_name = NULL; 454 nhp->h_aliases = (char **)((char *)nhp + al_off); 455 if ((pp = hp->h_aliases) != NULL) { 456 for (i = 0; *pp != NULL; pp++) { 457 if (**pp != '\0') { 458 nhp->h_aliases[i++] = cp; 459 strcpy(cp, *pp); 460 cp += strlen(cp) + 1; 461 } 462 } 463 } 464 nhp->h_aliases[nalias] = NULL; 465 cp = (char *)&nhp->h_aliases[nalias + 1]; 466 nhp->h_addrtype = hp->h_addrtype; 467 nhp->h_length = hp->h_length; 468 nhp->h_addr_list = (char **)cp; 469 if ((pp = hp->h_addr_list) != NULL) { 470 cp = (char *)&nhp->h_addr_list[naddr + 1]; 471 for (i = 0; *pp != NULL; pp++) { 472 nhp->h_addr_list[i++] = cp; 473 memcpy(cp, *pp, hp->h_length); 474 cp += addrsize; 475 } 476 } 477 nhp->h_addr_list[naddr] = NULL; 478 return nhp; 479} 480 481/* 482 * _hpaddr: construct hostent structure with one address 483 */ 484static struct hostent * 485_hpaddr(int af, const char *name, void *addr, int *errp) 486{ 487 struct hostent *hp, hpbuf; 488 char *addrs[2]; 489 490 hp = &hpbuf; 491 hp->h_name = (char *)name; 492 hp->h_aliases = NULL; 493 hp->h_addrtype = af; 494 hp->h_length = ADDRLEN(af); 495 hp->h_addr_list = addrs; 496 addrs[0] = (char *)addr; 497 addrs[1] = NULL; 498 return (_hpcopy(hp, errp)); 499} 500 501#ifdef INET6 502/* 503 * _hpmerge: merge 2 hostent structure, arguments will be freed 504 */ 505static struct hostent * 506_hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 507{ 508 int i, j; 509 int naddr, nalias; 510 char **pp; 511 struct hostent *hp, hpbuf; 512 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 513 union inx_addr addrbuf[MAXADDRS]; 514 515 if (hp1 == NULL) 516 return _hpcopy(hp2, errp); 517 if (hp2 == NULL) 518 return _hpcopy(hp1, errp); 519 520#define HP(i) (i == 1 ? hp1 : hp2) 521 hp = &hpbuf; 522 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 523 hp->h_aliases = aliases; 524 nalias = 0; 525 for (i = 1; i <= 2; i++) { 526 if ((pp = HP(i)->h_aliases) == NULL) 527 continue; 528 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 529 /* check duplicates */ 530 for (j = 0; j < nalias; j++) 531 if (strcasecmp(*pp, aliases[j]) == 0) 532 break; 533 if (j == nalias) 534 aliases[nalias++] = *pp; 535 } 536 } 537 aliases[nalias] = NULL; 538 if (hp1->h_length != hp2->h_length) { 539 hp->h_addrtype = AF_INET6; 540 hp->h_length = sizeof(struct in6_addr); 541 } else { 542 hp->h_addrtype = hp1->h_addrtype; 543 hp->h_length = hp1->h_length; 544 } 545 546 hp->h_addr_list = addrs; 547 naddr = 0; 548 for (i = 1; i <= 2; i++) { 549 if ((pp = HP(i)->h_addr_list) == NULL) 550 continue; 551 if (HP(i)->h_length == hp->h_length) { 552 while (naddr < MAXADDRS && *pp != NULL) 553 addrs[naddr++] = *pp++; 554 } else { 555 /* copy IPv4 addr as mapped IPv6 addr */ 556 while (naddr < MAXADDRS && *pp != NULL) { 557 MAPADDR(&addrbuf[naddr], *pp++); 558 addrs[naddr] = (char *)&addrbuf[naddr]; 559 naddr++; 560 } 561 } 562 } 563 addrs[naddr] = NULL; 564 return (_hpcopy(hp, errp)); 565} 566#endif 567 568/* 569 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 570 */ 571#ifdef INET6 572static struct hostent * 573_hpmapv6(struct hostent *hp, int *errp) 574{ 575 struct hostent hp6; 576 577 if (hp == NULL) 578 return NULL; 579 if (hp->h_addrtype == AF_INET6) 580 return _hpcopy(hp, errp); 581 582 memset(&hp6, 0, sizeof(struct hostent)); 583 hp6.h_addrtype = AF_INET6; 584 hp6.h_length = sizeof(struct in6_addr); 585 return _hpmerge(&hp6, hp, errp); 586} 587#endif 588 589/* 590 * _hpsort: sort address by sortlist 591 */ 592static struct hostent * 593_hpsort(struct hostent *hp, res_state statp) 594{ 595 int i, j, n; 596 u_char *ap, *sp, *mp, **pp; 597 char t; 598 char order[MAXADDRS]; 599 int nsort = statp->nsort; 600 601 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 602 return hp; 603 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 604 for (j = 0; j < nsort; j++) { 605#ifdef INET6 606 if (statp->_u._ext.ext->sort_list[j].af != 607 hp->h_addrtype) 608 continue; 609 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr; 610 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask; 611#else 612 sp = (u_char *)&statp->sort_list[j].addr; 613 mp = (u_char *)&statp->sort_list[j].mask; 614#endif 615 for (n = 0; n < hp->h_length; n++) { 616 if ((ap[n] & mp[n]) != sp[n]) 617 break; 618 } 619 if (n == hp->h_length) 620 break; 621 } 622 order[i] = j; 623 } 624 n = i; 625 pp = (u_char **)hp->h_addr_list; 626 for (i = 0; i < n - 1; i++) { 627 for (j = i + 1; j < n; j++) { 628 if (order[i] > order[j]) { 629 ap = pp[i]; 630 pp[i] = pp[j]; 631 pp[j] = ap; 632 t = order[i]; 633 order[i] = order[j]; 634 order[j] = t; 635 } 636 } 637 } 638 return hp; 639} 640 641#ifdef ENABLE_IP6ADDRCTL 642/* 643 * _hpreorder: sort address by default address selection 644 */ 645static struct hostent * 646_hpreorder(struct hostent *hp) 647{ 648 struct hp_order *aio; 649 int i, n; 650 char *ap; 651 struct sockaddr *sa; 652 struct policyhead policyhead; 653 654 if (hp == NULL) 655 return hp; 656 657 switch (hp->h_addrtype) { 658 case AF_INET: 659#ifdef INET6 660 case AF_INET6: 661#endif 662 break; 663 default: 664 free_addrselectpolicy(&policyhead); 665 return hp; 666 } 667 668 /* count the number of addrinfo elements for sorting. */ 669 for (n = 0; hp->h_addr_list[n] != NULL; n++) 670 ; 671 672 /* 673 * If the number is small enough, we can skip the reordering process. 674 */ 675 if (n <= 1) 676 return hp; 677 678 /* allocate a temporary array for sort and initialization of it. */ 679 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 680 return hp; /* give up reordering */ 681 memset(aio, 0, sizeof(*aio) * n); 682 683 /* retrieve address selection policy from the kernel */ 684 TAILQ_INIT(&policyhead); 685 if (!get_addrselectpolicy(&policyhead)) { 686 /* no policy is installed into kernel, we don't sort. */ 687 free(aio); 688 return hp; 689 } 690 691 for (i = 0; i < n; i++) { 692 ap = hp->h_addr_list[i]; 693 aio[i].aio_h_addr = ap; 694 sa = &aio[i].aio_sa; 695 switch (hp->h_addrtype) { 696 case AF_INET: 697 sa->sa_family = AF_INET; 698 sa->sa_len = sizeof(struct sockaddr_in); 699 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap, 700 sizeof(struct in_addr)); 701 break; 702#ifdef INET6 703 case AF_INET6: 704 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) { 705 sa->sa_family = AF_INET; 706 sa->sa_len = sizeof(struct sockaddr_in); 707 memcpy(&((struct sockaddr_in *)sa)->sin_addr, 708 &ap[12], sizeof(struct in_addr)); 709 } else { 710 sa->sa_family = AF_INET6; 711 sa->sa_len = sizeof(struct sockaddr_in6); 712 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr, 713 ap, sizeof(struct in6_addr)); 714 } 715 break; 716#endif 717 } 718 aio[i].aio_dstscope = gai_addr2scopetype(sa); 719 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead); 720 set_source(&aio[i], &policyhead); 721 } 722 723 /* perform sorting. */ 724 qsort(aio, n, sizeof(*aio), comp_dst); 725 726 /* reorder the h_addr_list. */ 727 for (i = 0; i < n; i++) 728 hp->h_addr_list[i] = aio[i].aio_h_addr; 729 730 /* cleanup and return */ 731 free(aio); 732 free_addrselectpolicy(&policyhead); 733 return hp; 734} 735 736static int 737get_addrselectpolicy(struct policyhead *head) 738{ 739#ifdef INET6 740 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 741 size_t l; 742 char *buf; 743 struct in6_addrpolicy *pol, *ep; 744 745 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 746 return (0); 747 if ((buf = malloc(l)) == NULL) 748 return (0); 749 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 750 free(buf); 751 return (0); 752 } 753 754 ep = (struct in6_addrpolicy *)(buf + l); 755 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 756 struct policyqueue *new; 757 758 if ((new = malloc(sizeof(*new))) == NULL) { 759 free_addrselectpolicy(head); /* make the list empty */ 760 break; 761 } 762 new->pc_policy = *pol; 763 TAILQ_INSERT_TAIL(head, new, pc_entry); 764 } 765 766 free(buf); 767 return (1); 768#else 769 return (0); 770#endif 771} 772 773static void 774free_addrselectpolicy(struct policyhead *head) 775{ 776 struct policyqueue *ent, *nent; 777 778 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 779 nent = TAILQ_NEXT(ent, pc_entry); 780 TAILQ_REMOVE(head, ent, pc_entry); 781 free(ent); 782 } 783} 784 785static struct policyqueue * 786match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 787{ 788#ifdef INET6 789 struct policyqueue *ent, *bestent = NULL; 790 struct in6_addrpolicy *pol; 791 int matchlen, bestmatchlen = -1; 792 u_char *mp, *ep, *k, *p, m; 793 struct sockaddr_in6 key; 794 795 switch(addr->sa_family) { 796 case AF_INET6: 797 key = *(struct sockaddr_in6 *)addr; 798 break; 799 case AF_INET: 800 /* convert the address into IPv4-mapped IPv6 address. */ 801 memset(&key, 0, sizeof(key)); 802 key.sin6_family = AF_INET6; 803 key.sin6_len = sizeof(key); 804 key.sin6_addr.s6_addr[10] = 0xff; 805 key.sin6_addr.s6_addr[11] = 0xff; 806 memcpy(&key.sin6_addr.s6_addr[12], 807 &((struct sockaddr_in *)addr)->sin_addr, 4); 808 break; 809 default: 810 return(NULL); 811 } 812 813 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 814 pol = &ent->pc_policy; 815 matchlen = 0; 816 817 mp = (u_char *)&pol->addrmask.sin6_addr; 818 ep = mp + 16; /* XXX: scope field? */ 819 k = (u_char *)&key.sin6_addr; 820 p = (u_char *)&pol->addr.sin6_addr; 821 for (; mp < ep && *mp; mp++, k++, p++) { 822 m = *mp; 823 if ((*k & m) != *p) 824 goto next; /* not match */ 825 if (m == 0xff) /* short cut for a typical case */ 826 matchlen += 8; 827 else { 828 while (m >= 0x80) { 829 matchlen++; 830 m <<= 1; 831 } 832 } 833 } 834 835 /* matched. check if this is better than the current best. */ 836 if (matchlen > bestmatchlen) { 837 bestent = ent; 838 bestmatchlen = matchlen; 839 } 840 841 next: 842 continue; 843 } 844 845 return(bestent); 846#else 847 return(NULL); 848#endif 849 850} 851 852static void 853set_source(struct hp_order *aio, struct policyhead *ph) 854{ 855 struct sockaddr_storage ss = aio->aio_un.aiou_ss; 856 socklen_t srclen; 857 int s; 858 859 /* set unspec ("no source is available"), just in case */ 860 aio->aio_srcsa.sa_family = AF_UNSPEC; 861 aio->aio_srcscope = -1; 862 863 switch(ss.ss_family) { 864 case AF_INET: 865 ((struct sockaddr_in *)&ss)->sin_port = htons(1); 866 break; 867#ifdef INET6 868 case AF_INET6: 869 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1); 870 break; 871#endif 872 default: /* ignore unsupported AFs explicitly */ 873 return; 874 } 875 876 /* open a socket to get the source address for the given dst */ 877 if ((s = _socket(ss.ss_family, SOCK_DGRAM, IPPROTO_UDP)) < 0) 878 return; /* give up */ 879 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0) 880 goto cleanup; 881 srclen = ss.ss_len; 882 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 883 aio->aio_srcsa.sa_family = AF_UNSPEC; 884 goto cleanup; 885 } 886 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 887 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 888 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss); 889#ifdef INET6 890 if (ss.ss_family == AF_INET6) { 891 struct in6_ifreq ifr6; 892 u_int32_t flags6; 893 894 memset(&ifr6, 0, sizeof(ifr6)); 895 memcpy(&ifr6.ifr_addr, &ss, ss.ss_len); 896 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 897 flags6 = ifr6.ifr_ifru.ifru_flags6; 898 if ((flags6 & IN6_IFF_DEPRECATED)) 899 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 900 } 901 } 902#endif 903 904 cleanup: 905 _close(s); 906 return; 907} 908 909static int 910matchlen(struct sockaddr *src, struct sockaddr *dst) 911{ 912 int match = 0; 913 u_char *s, *d; 914 u_char *lim, r; 915 int addrlen; 916 917 switch (src->sa_family) { 918#ifdef INET6 919 case AF_INET6: 920 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 921 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 922 addrlen = sizeof(struct in6_addr); 923 lim = s + addrlen; 924 break; 925#endif 926 case AF_INET: 927 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 928 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 929 addrlen = sizeof(struct in_addr); 930 lim = s + addrlen; 931 break; 932 default: 933 return(0); 934 } 935 936 while (s < lim) 937 if ((r = (*d++ ^ *s++)) != 0) { 938 while (r < addrlen * 8) { 939 match++; 940 r <<= 1; 941 } 942 break; 943 } else 944 match += 8; 945 return(match); 946} 947 948static int 949comp_dst(const void *arg1, const void *arg2) 950{ 951 const struct hp_order *dst1 = arg1, *dst2 = arg2; 952 953 /* 954 * Rule 1: Avoid unusable destinations. 955 * XXX: we currently do not consider if an appropriate route exists. 956 */ 957 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 958 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 959 return(-1); 960 } 961 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 962 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 963 return(1); 964 } 965 966 /* Rule 2: Prefer matching scope. */ 967 if (dst1->aio_dstscope == dst1->aio_srcscope && 968 dst2->aio_dstscope != dst2->aio_srcscope) { 969 return(-1); 970 } 971 if (dst1->aio_dstscope != dst1->aio_srcscope && 972 dst2->aio_dstscope == dst2->aio_srcscope) { 973 return(1); 974 } 975 976 /* Rule 3: Avoid deprecated addresses. */ 977 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 978 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 979 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 980 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 981 return(-1); 982 } 983 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 984 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 985 return(1); 986 } 987 } 988 989 /* Rule 4: Prefer home addresses. */ 990 /* XXX: not implemented yet */ 991 992 /* Rule 5: Prefer matching label. */ 993#ifdef INET6 994 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 995 dst1->aio_srcpolicy->pc_policy.label == 996 dst1->aio_dstpolicy->pc_policy.label && 997 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 998 dst2->aio_srcpolicy->pc_policy.label != 999 dst2->aio_dstpolicy->pc_policy.label)) { 1000 return(-1); 1001 } 1002 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 1003 dst2->aio_srcpolicy->pc_policy.label == 1004 dst2->aio_dstpolicy->pc_policy.label && 1005 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1006 dst1->aio_srcpolicy->pc_policy.label != 1007 dst1->aio_dstpolicy->pc_policy.label)) { 1008 return(1); 1009 } 1010#endif 1011 1012 /* Rule 6: Prefer higher precedence. */ 1013#ifdef INET6 1014 if (dst1->aio_dstpolicy && 1015 (dst2->aio_dstpolicy == NULL || 1016 dst1->aio_dstpolicy->pc_policy.preced > 1017 dst2->aio_dstpolicy->pc_policy.preced)) { 1018 return(-1); 1019 } 1020 if (dst2->aio_dstpolicy && 1021 (dst1->aio_dstpolicy == NULL || 1022 dst2->aio_dstpolicy->pc_policy.preced > 1023 dst1->aio_dstpolicy->pc_policy.preced)) { 1024 return(1); 1025 } 1026#endif 1027 1028 /* Rule 7: Prefer native transport. */ 1029 /* XXX: not implemented yet */ 1030 1031 /* Rule 8: Prefer smaller scope. */ 1032 if (dst1->aio_dstscope >= 0 && 1033 dst1->aio_dstscope < dst2->aio_dstscope) { 1034 return(-1); 1035 } 1036 if (dst2->aio_dstscope >= 0 && 1037 dst2->aio_dstscope < dst1->aio_dstscope) { 1038 return(1); 1039 } 1040 1041 /* 1042 * Rule 9: Use longest matching prefix. 1043 * We compare the match length in a same AF only. 1044 */ 1045 if (dst1->aio_sa.sa_family == dst2->aio_sa.sa_family) { 1046 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1047 return(-1); 1048 } 1049 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1050 return(1); 1051 } 1052 } 1053 1054 /* Rule 10: Otherwise, leave the order unchanged. */ 1055 return(-1); 1056} 1057 1058/* 1059 * Copy from scope.c. 1060 * XXX: we should standardize the functions and link them as standard 1061 * library. 1062 */ 1063static int 1064gai_addr2scopetype(struct sockaddr *sa) 1065{ 1066#ifdef INET6 1067 struct sockaddr_in6 *sa6; 1068#endif 1069 struct sockaddr_in *sa4; 1070 1071 switch(sa->sa_family) { 1072#ifdef INET6 1073 case AF_INET6: 1074 sa6 = (struct sockaddr_in6 *)sa; 1075 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1076 /* just use the scope field of the multicast address */ 1077 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1078 } 1079 /* 1080 * Unicast addresses: map scope type to corresponding scope 1081 * value defined for multcast addresses. 1082 * XXX: hardcoded scope type values are bad... 1083 */ 1084 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1085 return(1); /* node local scope */ 1086 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1087 return(2); /* link-local scope */ 1088 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1089 return(5); /* site-local scope */ 1090 return(14); /* global scope */ 1091 break; 1092#endif 1093 case AF_INET: 1094 /* 1095 * IPv4 pseudo scoping according to RFC 3484. 1096 */ 1097 sa4 = (struct sockaddr_in *)sa; 1098 /* IPv4 autoconfiguration addresses have link-local scope. */ 1099 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1100 ((u_char *)&sa4->sin_addr)[1] == 254) 1101 return(2); 1102 /* Private addresses have site-local scope. */ 1103 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1104 (((u_char *)&sa4->sin_addr)[0] == 172 && 1105 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1106 (((u_char *)&sa4->sin_addr)[0] == 192 && 1107 ((u_char *)&sa4->sin_addr)[1] == 168)) 1108 return(14); /* XXX: It should be 5 unless NAT */ 1109 /* Loopback addresses have link-local scope. */ 1110 if (((u_char *)&sa4->sin_addr)[0] == 127) 1111 return(2); 1112 return(14); 1113 break; 1114 default: 1115 errno = EAFNOSUPPORT; /* is this a good error? */ 1116 return(-1); 1117 } 1118} 1119#endif 1120