1 /* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 itojun Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 /* 34 * ++Copyright++ 1985, 1988, 1993 35 * - 36 * Copyright (c) 1985, 1988, 1993 37 * The Regents of the University of California. All rights reserved. 38 * 39 * Redistribution and use in source and binary forms, with or without 40 * modification, are permitted provided that the following conditions 41 * are met: 42 * 1. Redistributions of source code must retain the above copyright 43 * notice, this list of conditions and the following disclaimer. 44 * 2. Redistributions in binary form must reproduce the above copyright 45 * notice, this list of conditions and the following disclaimer in the 46 * documentation and/or other materials provided with the distribution. 47 * 3. Neither the name of the University nor the names of its contributors 48 * may be used to endorse or promote products derived from this software 49 * without specific prior written permission. 50 * 51 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 52 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 53 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 54 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 55 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 56 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 57 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 59 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 60 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 61 * SUCH DAMAGE. 62 * - 63 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 64 * 65 * Permission to use, copy, modify, and distribute this software for any 66 * purpose with or without fee is hereby granted, provided that the above 67 * copyright notice and this permission notice appear in all copies, and that 68 * the name of Digital Equipment Corporation not be used in advertising or 69 * publicity pertaining to distribution of the document or software without 70 * specific, written prior permission. 71 * 72 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 73 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 74 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 75 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 76 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 77 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 78 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 79 * SOFTWARE. 80 * - 81 * --Copyright-- 82 */ 83 84 /* 85 * Atsushi Onoe <onoe@sm.sony.co.jp> 86 */ 87 88 #include <sys/cdefs.h> 89 #include "namespace.h" 90 #include <sys/param.h> 91 #include <sys/socket.h> 92 #include <sys/time.h> 93 #include <sys/queue.h> 94 #include <netinet/in.h> 95 #ifdef INET6 96 #include <net/if.h> 97 #include <sys/sysctl.h> 98 #include <sys/ioctl.h> 99 #include <netinet6/in6_var.h> /* XXX */ 100 #endif 101 102 #include <arpa/inet.h> 103 #include <arpa/nameser.h> 104 105 #include <errno.h> 106 #include <netdb.h> 107 #include <resolv.h> 108 #include <stdio.h> 109 #include <stdlib.h> 110 #include <string.h> 111 #include <stdarg.h> 112 #include <nsswitch.h> 113 #include <unistd.h> 114 #include "un-namespace.h" 115 #include "netdb_private.h" 116 #include "res_private.h" 117 118 #ifndef MAXALIASES 119 #define MAXALIASES 10 120 #endif 121 #ifndef MAXADDRS 122 #define MAXADDRS 20 123 #endif 124 #ifndef MAXDNAME 125 #define MAXDNAME 1025 126 #endif 127 128 #ifdef INET6 129 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 130 sizeof(struct in_addr)) 131 #else 132 #define ADDRLEN(af) sizeof(struct in_addr) 133 #endif 134 135 #define MAPADDR(ab, ina) \ 136 do { \ 137 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 138 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 139 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 140 } while (0) 141 #define MAPADDRENABLED(flags) \ 142 (((flags) & AI_V4MAPPED) || \ 143 (((flags) & AI_V4MAPPED_CFG))) 144 145 union inx_addr { 146 struct in_addr in_addr; 147 #ifdef INET6 148 struct in6_addr in6_addr; 149 #endif 150 struct { 151 u_char mau_zero[10]; 152 u_char mau_one[2]; 153 struct in_addr mau_inaddr; 154 } map_addr_un; 155 #define map_zero map_addr_un.mau_zero 156 #define map_one map_addr_un.mau_one 157 #define map_inaddr map_addr_un.mau_inaddr 158 }; 159 160 struct policyqueue { 161 TAILQ_ENTRY(policyqueue) pc_entry; 162 #ifdef INET6 163 struct in6_addrpolicy pc_policy; 164 #endif 165 }; 166 TAILQ_HEAD(policyhead, policyqueue); 167 168 #define AIO_SRCFLAG_DEPRECATED 0x1 169 170 struct hp_order { 171 union { 172 struct sockaddr_storage aiou_ss; 173 struct sockaddr aiou_sa; 174 } aio_src_un; 175 #define aio_srcsa aio_src_un.aiou_sa 176 u_int32_t aio_srcflag; 177 int aio_srcscope; 178 int aio_dstscope; 179 struct policyqueue *aio_srcpolicy; 180 struct policyqueue *aio_dstpolicy; 181 union { 182 struct sockaddr_storage aiou_ss; 183 struct sockaddr aiou_sa; 184 } aio_un; 185 #define aio_sa aio_un.aiou_sa 186 int aio_matchlen; 187 char *aio_h_addr; 188 int aio_initial_sequence; 189 }; 190 191 static struct hostent *_hpcopy(struct hostent *, int *); 192 static struct hostent *_hpaddr(int, const char *, void *, int *); 193 #ifdef INET6 194 static struct hostent *_hpmerge(struct hostent *, struct hostent *, int *); 195 static struct hostent *_hpmapv6(struct hostent *, int *); 196 #endif 197 static struct hostent *_hpsort(struct hostent *, res_state); 198 199 #ifdef INET6 200 static struct hostent *_hpreorder(struct hostent *); 201 static int get_addrselectpolicy(struct policyhead *); 202 static void free_addrselectpolicy(struct policyhead *); 203 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 204 struct policyhead *); 205 static void set_source(struct hp_order *, struct policyhead *); 206 static int matchlen(struct sockaddr *, struct sockaddr *); 207 static int comp_dst(const void *, const void *); 208 static int gai_addr2scopetype(struct sockaddr *); 209 #endif 210 211 /* 212 * Functions defined in RFC2553 213 * getipnodebyname, getipnodebyaddr, freehostent 214 */ 215 216 struct hostent * 217 getipnodebyname(const char *name, int af, int flags, int *errp) 218 { 219 struct hostent *hp; 220 union inx_addr addrbuf; 221 res_state statp; 222 u_long options; 223 224 switch (af) { 225 case AF_INET: 226 #ifdef INET6 227 case AF_INET6: 228 #endif 229 break; 230 default: 231 *errp = NO_RECOVERY; 232 return NULL; 233 } 234 235 if (flags & AI_ADDRCONFIG) { 236 int s; 237 238 if ((s = _socket(af, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 239 return NULL; 240 /* 241 * TODO: 242 * Note that implementation dependent test for address 243 * configuration should be done every time called 244 * (or appropriate interval), 245 * because addresses will be dynamically assigned or deleted. 246 */ 247 _close(s); 248 } 249 250 #ifdef INET6 251 /* special case for literal address */ 252 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 253 if (af != AF_INET6) { 254 *errp = HOST_NOT_FOUND; 255 return NULL; 256 } 257 return _hpaddr(af, name, &addrbuf, errp); 258 } 259 #endif 260 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 261 if (af != AF_INET) { 262 if (MAPADDRENABLED(flags)) { 263 MAPADDR(&addrbuf, &addrbuf.in_addr); 264 } else { 265 *errp = HOST_NOT_FOUND; 266 return NULL; 267 } 268 } 269 return _hpaddr(af, name, &addrbuf, errp); 270 } 271 272 273 statp = __res_state(); 274 if ((statp->options & RES_INIT) == 0) { 275 if (res_ninit(statp) < 0) { 276 *errp = NETDB_INTERNAL; 277 return NULL; 278 } 279 } 280 281 options = statp->options; 282 statp->options &= ~RES_USE_INET6; 283 284 hp = gethostbyname2(name, af); 285 hp = _hpcopy(hp, errp); 286 #ifdef INET6 287 if (af == AF_INET6) 288 hp = _hpreorder(hp); 289 290 if (af == AF_INET6 && ((flags & AI_ALL) || hp == NULL) && 291 MAPADDRENABLED(flags)) { 292 struct hostent *hp2 = gethostbyname2(name, AF_INET); 293 if (hp == NULL) 294 if (hp2 == NULL) 295 *errp = statp->res_h_errno; 296 else 297 hp = _hpmapv6(hp2, errp); 298 else { 299 if (hp2 && strcmp(hp->h_name, hp2->h_name) == 0) { 300 struct hostent *hpb = hp; 301 hp = _hpmerge(hpb, hp2, errp); 302 freehostent(hpb); 303 } 304 } 305 } 306 #endif 307 308 if (hp == NULL) 309 *errp = statp->res_h_errno; 310 311 statp->options = options; 312 return _hpsort(hp, statp); 313 } 314 315 struct hostent * 316 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 317 { 318 struct hostent *hp; 319 res_state statp; 320 u_long options; 321 322 #ifdef INET6 323 struct in6_addr addrbuf; 324 #else 325 struct in_addr addrbuf; 326 #endif 327 328 switch (af) { 329 case AF_INET: 330 if (len != sizeof(struct in_addr)) { 331 *errp = NO_RECOVERY; 332 return NULL; 333 } 334 if (rounddown2((long)src, sizeof(struct in_addr))) { 335 memcpy(&addrbuf, src, len); 336 src = &addrbuf; 337 } 338 if (((struct in_addr *)src)->s_addr == 0) 339 return NULL; 340 break; 341 #ifdef INET6 342 case AF_INET6: 343 if (len != sizeof(struct in6_addr)) { 344 *errp = NO_RECOVERY; 345 return NULL; 346 } 347 if (rounddown2((long)src, sizeof(struct in6_addr) / 2)) { 348 /* XXX */ 349 memcpy(&addrbuf, src, len); 350 src = &addrbuf; 351 } 352 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 353 return NULL; 354 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 355 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 356 src = (char *)src + 357 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 358 af = AF_INET; 359 len = sizeof(struct in_addr); 360 } 361 break; 362 #endif 363 default: 364 *errp = NO_RECOVERY; 365 return NULL; 366 } 367 368 statp = __res_state(); 369 if ((statp->options & RES_INIT) == 0) { 370 if (res_ninit(statp) < 0) { 371 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 372 return NULL; 373 } 374 } 375 376 options = statp->options; 377 statp->options &= ~RES_USE_INET6; 378 379 hp = gethostbyaddr(src, len, af); 380 if (hp == NULL) 381 *errp = statp->res_h_errno; 382 383 statp->options = options; 384 return (_hpcopy(hp, errp)); 385 } 386 387 void 388 freehostent(struct hostent *ptr) 389 { 390 free(ptr); 391 } 392 393 /* 394 * Private utility functions 395 */ 396 397 /* 398 * _hpcopy: allocate and copy hostent structure 399 */ 400 static struct hostent * 401 _hpcopy(struct hostent *hp, int *errp) 402 { 403 struct hostent *nhp; 404 char *cp, **pp; 405 int size, addrsize; 406 int nalias = 0, naddr = 0; 407 int al_off; 408 int i; 409 410 if (hp == NULL) 411 return hp; 412 413 /* count size to be allocated */ 414 size = sizeof(struct hostent); 415 if (hp->h_name != NULL) 416 size += strlen(hp->h_name) + 1; 417 if ((pp = hp->h_aliases) != NULL) { 418 for (i = 0; *pp != NULL; i++, pp++) { 419 if (**pp != '\0') { 420 size += strlen(*pp) + 1; 421 nalias++; 422 } 423 } 424 } 425 /* adjust alignment */ 426 size = ALIGN(size); 427 al_off = size; 428 size += sizeof(char *) * (nalias + 1); 429 addrsize = ALIGN(hp->h_length); 430 if ((pp = hp->h_addr_list) != NULL) { 431 while (*pp++ != NULL) 432 naddr++; 433 } 434 size += addrsize * naddr; 435 size += sizeof(char *) * (naddr + 1); 436 437 /* copy */ 438 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 439 *errp = TRY_AGAIN; 440 return NULL; 441 } 442 cp = (char *)&nhp[1]; 443 if (hp->h_name != NULL) { 444 nhp->h_name = cp; 445 strcpy(cp, hp->h_name); 446 cp += strlen(cp) + 1; 447 } else 448 nhp->h_name = NULL; 449 nhp->h_aliases = (char **)((char *)nhp + al_off); 450 if ((pp = hp->h_aliases) != NULL) { 451 for (i = 0; *pp != NULL; pp++) { 452 if (**pp != '\0') { 453 nhp->h_aliases[i++] = cp; 454 strcpy(cp, *pp); 455 cp += strlen(cp) + 1; 456 } 457 } 458 } 459 nhp->h_aliases[nalias] = NULL; 460 cp = (char *)&nhp->h_aliases[nalias + 1]; 461 nhp->h_addrtype = hp->h_addrtype; 462 nhp->h_length = hp->h_length; 463 nhp->h_addr_list = (char **)cp; 464 if ((pp = hp->h_addr_list) != NULL) { 465 cp = (char *)&nhp->h_addr_list[naddr + 1]; 466 for (i = 0; *pp != NULL; pp++) { 467 nhp->h_addr_list[i++] = cp; 468 memcpy(cp, *pp, hp->h_length); 469 cp += addrsize; 470 } 471 } 472 nhp->h_addr_list[naddr] = NULL; 473 return nhp; 474 } 475 476 /* 477 * _hpaddr: construct hostent structure with one address 478 */ 479 static struct hostent * 480 _hpaddr(int af, const char *name, void *addr, int *errp) 481 { 482 struct hostent *hp, hpbuf; 483 char *addrs[2]; 484 485 hp = &hpbuf; 486 hp->h_name = (char *)name; 487 hp->h_aliases = NULL; 488 hp->h_addrtype = af; 489 hp->h_length = ADDRLEN(af); 490 hp->h_addr_list = addrs; 491 addrs[0] = (char *)addr; 492 addrs[1] = NULL; 493 return (_hpcopy(hp, errp)); 494 } 495 496 #ifdef INET6 497 /* 498 * _hpmerge: merge 2 hostent structure, arguments will be freed 499 */ 500 static struct hostent * 501 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 502 { 503 int i, j; 504 int naddr, nalias; 505 char **pp; 506 struct hostent *hp, hpbuf; 507 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 508 union inx_addr addrbuf[MAXADDRS]; 509 510 if (hp1 == NULL) 511 return _hpcopy(hp2, errp); 512 if (hp2 == NULL) 513 return _hpcopy(hp1, errp); 514 515 #define HP(i) (i == 1 ? hp1 : hp2) 516 hp = &hpbuf; 517 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 518 hp->h_aliases = aliases; 519 nalias = 0; 520 for (i = 1; i <= 2; i++) { 521 if ((pp = HP(i)->h_aliases) == NULL) 522 continue; 523 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 524 /* check duplicates */ 525 for (j = 0; j < nalias; j++) 526 if (strcasecmp(*pp, aliases[j]) == 0) 527 break; 528 if (j == nalias) 529 aliases[nalias++] = *pp; 530 } 531 } 532 aliases[nalias] = NULL; 533 if (hp1->h_length != hp2->h_length) { 534 hp->h_addrtype = AF_INET6; 535 hp->h_length = sizeof(struct in6_addr); 536 } else { 537 hp->h_addrtype = hp1->h_addrtype; 538 hp->h_length = hp1->h_length; 539 } 540 541 hp->h_addr_list = addrs; 542 naddr = 0; 543 for (i = 1; i <= 2; i++) { 544 if ((pp = HP(i)->h_addr_list) == NULL) 545 continue; 546 if (HP(i)->h_length == hp->h_length) { 547 while (naddr < MAXADDRS && *pp != NULL) 548 addrs[naddr++] = *pp++; 549 } else { 550 /* copy IPv4 addr as mapped IPv6 addr */ 551 while (naddr < MAXADDRS && *pp != NULL) { 552 MAPADDR(&addrbuf[naddr], *pp++); 553 addrs[naddr] = (char *)&addrbuf[naddr]; 554 naddr++; 555 } 556 } 557 } 558 addrs[naddr] = NULL; 559 return (_hpcopy(hp, errp)); 560 } 561 #endif 562 563 /* 564 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 565 */ 566 #ifdef INET6 567 static struct hostent * 568 _hpmapv6(struct hostent *hp, int *errp) 569 { 570 struct hostent hp6; 571 572 if (hp == NULL) 573 return NULL; 574 if (hp->h_addrtype == AF_INET6) 575 return _hpcopy(hp, errp); 576 577 memset(&hp6, 0, sizeof(struct hostent)); 578 hp6.h_addrtype = AF_INET6; 579 hp6.h_length = sizeof(struct in6_addr); 580 return _hpmerge(&hp6, hp, errp); 581 } 582 #endif 583 584 /* 585 * _hpsort: sort address by sortlist 586 */ 587 static struct hostent * 588 _hpsort(struct hostent *hp, res_state statp) 589 { 590 int i, j, n; 591 u_char *ap, *sp, *mp, **pp; 592 char t; 593 char order[MAXADDRS]; 594 int nsort = statp->nsort; 595 596 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 597 return hp; 598 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 599 for (j = 0; j < nsort; j++) { 600 #ifdef INET6 601 if (statp->_u._ext.ext->sort_list[j].af != 602 hp->h_addrtype) 603 continue; 604 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr; 605 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask; 606 #else 607 sp = (u_char *)&statp->sort_list[j].addr; 608 mp = (u_char *)&statp->sort_list[j].mask; 609 #endif 610 for (n = 0; n < hp->h_length; n++) { 611 if ((ap[n] & mp[n]) != sp[n]) 612 break; 613 } 614 if (n == hp->h_length) 615 break; 616 } 617 order[i] = j; 618 } 619 n = i; 620 pp = (u_char **)hp->h_addr_list; 621 for (i = 0; i < n - 1; i++) { 622 for (j = i + 1; j < n; j++) { 623 if (order[i] > order[j]) { 624 ap = pp[i]; 625 pp[i] = pp[j]; 626 pp[j] = ap; 627 t = order[i]; 628 order[i] = order[j]; 629 order[j] = t; 630 } 631 } 632 } 633 return hp; 634 } 635 636 #ifdef INET6 637 /* 638 * _hpreorder: sort address by default address selection 639 */ 640 static struct hostent * 641 _hpreorder(struct hostent *hp) 642 { 643 struct hp_order *aio; 644 int i, n; 645 char *ap; 646 struct sockaddr *sa; 647 struct policyhead policyhead; 648 649 if (hp == NULL) 650 return hp; 651 652 switch (hp->h_addrtype) { 653 case AF_INET: 654 #ifdef INET6 655 case AF_INET6: 656 #endif 657 break; 658 default: 659 return hp; 660 } 661 662 /* count the number of addrinfo elements for sorting. */ 663 for (n = 0; hp->h_addr_list[n] != NULL; n++) 664 ; 665 666 /* 667 * If the number is small enough, we can skip the reordering process. 668 */ 669 if (n <= 1) 670 return hp; 671 672 /* allocate a temporary array for sort and initialization of it. */ 673 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 674 return hp; /* give up reordering */ 675 memset(aio, 0, sizeof(*aio) * n); 676 677 /* retrieve address selection policy from the kernel */ 678 TAILQ_INIT(&policyhead); 679 if (!get_addrselectpolicy(&policyhead)) { 680 /* no policy is installed into kernel, we don't sort. */ 681 free(aio); 682 return hp; 683 } 684 685 for (i = 0; i < n; i++) { 686 ap = hp->h_addr_list[i]; 687 aio[i].aio_h_addr = ap; 688 sa = &aio[i].aio_sa; 689 switch (hp->h_addrtype) { 690 case AF_INET: 691 sa->sa_family = AF_INET; 692 sa->sa_len = sizeof(struct sockaddr_in); 693 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap, 694 sizeof(struct in_addr)); 695 break; 696 #ifdef INET6 697 case AF_INET6: 698 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) { 699 sa->sa_family = AF_INET; 700 sa->sa_len = sizeof(struct sockaddr_in); 701 memcpy(&((struct sockaddr_in *)sa)->sin_addr, 702 &ap[12], sizeof(struct in_addr)); 703 } else { 704 sa->sa_family = AF_INET6; 705 sa->sa_len = sizeof(struct sockaddr_in6); 706 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr, 707 ap, sizeof(struct in6_addr)); 708 } 709 break; 710 #endif 711 } 712 aio[i].aio_dstscope = gai_addr2scopetype(sa); 713 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead); 714 set_source(&aio[i], &policyhead); 715 aio[i].aio_initial_sequence = i; 716 } 717 718 /* perform sorting. */ 719 qsort(aio, n, sizeof(*aio), comp_dst); 720 721 /* reorder the h_addr_list. */ 722 for (i = 0; i < n; i++) 723 hp->h_addr_list[i] = aio[i].aio_h_addr; 724 725 /* cleanup and return */ 726 free(aio); 727 free_addrselectpolicy(&policyhead); 728 return hp; 729 } 730 731 static int 732 get_addrselectpolicy(struct policyhead *head) 733 { 734 #ifdef INET6 735 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 736 size_t l; 737 char *buf; 738 struct in6_addrpolicy *pol, *ep; 739 740 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) 741 return (0); 742 if ((buf = malloc(l)) == NULL) 743 return (0); 744 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 745 free(buf); 746 return (0); 747 } 748 749 ep = (struct in6_addrpolicy *)(buf + l); 750 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 751 struct policyqueue *new; 752 753 if ((new = malloc(sizeof(*new))) == NULL) { 754 free_addrselectpolicy(head); /* make the list empty */ 755 break; 756 } 757 new->pc_policy = *pol; 758 TAILQ_INSERT_TAIL(head, new, pc_entry); 759 } 760 761 free(buf); 762 return (1); 763 #else 764 return (0); 765 #endif 766 } 767 768 static void 769 free_addrselectpolicy(struct policyhead *head) 770 { 771 struct policyqueue *ent, *nent; 772 773 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 774 nent = TAILQ_NEXT(ent, pc_entry); 775 TAILQ_REMOVE(head, ent, pc_entry); 776 free(ent); 777 } 778 } 779 780 static struct policyqueue * 781 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 782 { 783 #ifdef INET6 784 struct policyqueue *ent, *bestent = NULL; 785 struct in6_addrpolicy *pol; 786 int matchlen, bestmatchlen = -1; 787 u_char *mp, *ep, *k, *p, m; 788 struct sockaddr_in6 key; 789 790 switch(addr->sa_family) { 791 case AF_INET6: 792 key = *(struct sockaddr_in6 *)addr; 793 break; 794 case AF_INET: 795 /* convert the address into IPv4-mapped IPv6 address. */ 796 memset(&key, 0, sizeof(key)); 797 key.sin6_family = AF_INET6; 798 key.sin6_len = sizeof(key); 799 _map_v4v6_address( 800 (char *)&((struct sockaddr_in *)addr)->sin_addr, 801 (char *)&key.sin6_addr); 802 break; 803 default: 804 return(NULL); 805 } 806 807 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 808 pol = &ent->pc_policy; 809 matchlen = 0; 810 811 mp = (u_char *)&pol->addrmask.sin6_addr; 812 ep = mp + 16; /* XXX: scope field? */ 813 k = (u_char *)&key.sin6_addr; 814 p = (u_char *)&pol->addr.sin6_addr; 815 for (; mp < ep && *mp; mp++, k++, p++) { 816 m = *mp; 817 if ((*k & m) != *p) 818 goto next; /* not match */ 819 if (m == 0xff) /* short cut for a typical case */ 820 matchlen += 8; 821 else { 822 while (m >= 0x80) { 823 matchlen++; 824 m <<= 1; 825 } 826 } 827 } 828 829 /* matched. check if this is better than the current best. */ 830 if (matchlen > bestmatchlen) { 831 bestent = ent; 832 bestmatchlen = matchlen; 833 } 834 835 next: 836 continue; 837 } 838 839 return(bestent); 840 #else 841 return(NULL); 842 #endif 843 844 } 845 846 static void 847 set_source(struct hp_order *aio, struct policyhead *ph) 848 { 849 struct sockaddr_storage ss = aio->aio_un.aiou_ss; 850 socklen_t srclen; 851 int s; 852 853 /* set unspec ("no source is available"), just in case */ 854 aio->aio_srcsa.sa_family = AF_UNSPEC; 855 aio->aio_srcscope = -1; 856 857 switch(ss.ss_family) { 858 case AF_INET: 859 ((struct sockaddr_in *)&ss)->sin_port = htons(1); 860 break; 861 #ifdef INET6 862 case AF_INET6: 863 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1); 864 break; 865 #endif 866 default: /* ignore unsupported AFs explicitly */ 867 return; 868 } 869 870 /* open a socket to get the source address for the given dst */ 871 if ((s = _socket(ss.ss_family, SOCK_DGRAM | SOCK_CLOEXEC, 872 IPPROTO_UDP)) < 0) 873 return; /* give up */ 874 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0) 875 goto cleanup; 876 srclen = ss.ss_len; 877 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 878 aio->aio_srcsa.sa_family = AF_UNSPEC; 879 goto cleanup; 880 } 881 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 882 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 883 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss); 884 #ifdef INET6 885 if (ss.ss_family == AF_INET6) { 886 struct in6_ifreq ifr6; 887 u_int32_t flags6; 888 889 memset(&ifr6, 0, sizeof(ifr6)); 890 memcpy(&ifr6.ifr_addr, &ss, ss.ss_len); 891 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 892 flags6 = ifr6.ifr_ifru.ifru_flags6; 893 if ((flags6 & IN6_IFF_DEPRECATED)) 894 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 895 } 896 } 897 #endif 898 899 cleanup: 900 _close(s); 901 return; 902 } 903 904 static int 905 matchlen(struct sockaddr *src, struct sockaddr *dst) 906 { 907 int match = 0; 908 u_char *s, *d; 909 u_char *lim, r; 910 int addrlen; 911 912 switch (src->sa_family) { 913 #ifdef INET6 914 case AF_INET6: 915 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 916 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 917 addrlen = sizeof(struct in6_addr); 918 lim = s + addrlen; 919 break; 920 #endif 921 case AF_INET: 922 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 923 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 924 addrlen = sizeof(struct in_addr); 925 lim = s + addrlen; 926 break; 927 default: 928 return(0); 929 } 930 931 while (s < lim) 932 if ((r = (*d++ ^ *s++)) != 0) { 933 while ((r & 0x80) == 0) { 934 match++; 935 r <<= 1; 936 } 937 break; 938 } else 939 match += 8; 940 return(match); 941 } 942 943 static int 944 comp_dst(const void *arg1, const void *arg2) 945 { 946 const struct hp_order *dst1 = arg1, *dst2 = arg2; 947 948 /* 949 * Rule 1: Avoid unusable destinations. 950 * XXX: we currently do not consider if an appropriate route exists. 951 */ 952 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 953 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 954 return(-1); 955 } 956 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 957 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 958 return(1); 959 } 960 961 /* Rule 2: Prefer matching scope. */ 962 if (dst1->aio_dstscope == dst1->aio_srcscope && 963 dst2->aio_dstscope != dst2->aio_srcscope) { 964 return(-1); 965 } 966 if (dst1->aio_dstscope != dst1->aio_srcscope && 967 dst2->aio_dstscope == dst2->aio_srcscope) { 968 return(1); 969 } 970 971 /* Rule 3: Avoid deprecated addresses. */ 972 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 973 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 974 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 975 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 976 return(-1); 977 } 978 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 979 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 980 return(1); 981 } 982 } 983 984 /* Rule 4: Prefer home addresses. */ 985 /* XXX: not implemented yet */ 986 987 /* Rule 5: Prefer matching label. */ 988 #ifdef INET6 989 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 990 dst1->aio_srcpolicy->pc_policy.label == 991 dst1->aio_dstpolicy->pc_policy.label && 992 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 993 dst2->aio_srcpolicy->pc_policy.label != 994 dst2->aio_dstpolicy->pc_policy.label)) { 995 return(-1); 996 } 997 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 998 dst2->aio_srcpolicy->pc_policy.label == 999 dst2->aio_dstpolicy->pc_policy.label && 1000 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1001 dst1->aio_srcpolicy->pc_policy.label != 1002 dst1->aio_dstpolicy->pc_policy.label)) { 1003 return(1); 1004 } 1005 #endif 1006 1007 /* Rule 6: Prefer higher precedence. */ 1008 #ifdef INET6 1009 if (dst1->aio_dstpolicy && 1010 (dst2->aio_dstpolicy == NULL || 1011 dst1->aio_dstpolicy->pc_policy.preced > 1012 dst2->aio_dstpolicy->pc_policy.preced)) { 1013 return(-1); 1014 } 1015 if (dst2->aio_dstpolicy && 1016 (dst1->aio_dstpolicy == NULL || 1017 dst2->aio_dstpolicy->pc_policy.preced > 1018 dst1->aio_dstpolicy->pc_policy.preced)) { 1019 return(1); 1020 } 1021 #endif 1022 1023 /* Rule 7: Prefer native transport. */ 1024 /* XXX: not implemented yet */ 1025 1026 /* Rule 8: Prefer smaller scope. */ 1027 if (dst1->aio_dstscope >= 0 && 1028 dst1->aio_dstscope < dst2->aio_dstscope) { 1029 return(-1); 1030 } 1031 if (dst2->aio_dstscope >= 0 && 1032 dst2->aio_dstscope < dst1->aio_dstscope) { 1033 return(1); 1034 } 1035 1036 /* 1037 * Rule 9: Use longest matching prefix. 1038 * We compare the match length in a same AF only. 1039 */ 1040 if (dst1->aio_sa.sa_family == dst2->aio_sa.sa_family) { 1041 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1042 return(-1); 1043 } 1044 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1045 return(1); 1046 } 1047 } 1048 1049 /* Rule 10: Otherwise, leave the order unchanged. */ 1050 1051 /* 1052 * Note that qsort is unstable; so, we can't return zero and 1053 * expect the order to be unchanged. 1054 * That also means we can't depend on the current position of 1055 * dst2 being after dst1. We must enforce the initial order 1056 * with an explicit compare on the original position. 1057 * The qsort specification requires that "When the same objects 1058 * (consisting of width bytes, irrespective of their current 1059 * positions in the array) are passed more than once to the 1060 * comparison function, the results shall be consistent with one 1061 * another." 1062 * In other words, If A < B, then we must also return B > A. 1063 */ 1064 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1065 return(1); 1066 1067 return(-1); 1068 } 1069 1070 /* 1071 * Copy from scope.c. 1072 * XXX: we should standardize the functions and link them as standard 1073 * library. 1074 */ 1075 static int 1076 gai_addr2scopetype(struct sockaddr *sa) 1077 { 1078 #ifdef INET6 1079 struct sockaddr_in6 *sa6; 1080 #endif 1081 struct sockaddr_in *sa4; 1082 1083 switch(sa->sa_family) { 1084 #ifdef INET6 1085 case AF_INET6: 1086 sa6 = (struct sockaddr_in6 *)sa; 1087 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1088 /* just use the scope field of the multicast address */ 1089 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1090 } 1091 /* 1092 * Unicast addresses: map scope type to corresponding scope 1093 * value defined for multcast addresses. 1094 * XXX: hardcoded scope type values are bad... 1095 */ 1096 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1097 return(1); /* node local scope */ 1098 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1099 return(2); /* link-local scope */ 1100 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1101 return(5); /* site-local scope */ 1102 return(14); /* global scope */ 1103 break; 1104 #endif 1105 case AF_INET: 1106 /* 1107 * IPv4 pseudo scoping according to RFC 3484. 1108 */ 1109 sa4 = (struct sockaddr_in *)sa; 1110 /* IPv4 autoconfiguration addresses have link-local scope. */ 1111 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1112 ((u_char *)&sa4->sin_addr)[1] == 254) 1113 return(2); 1114 /* Private addresses have site-local scope. */ 1115 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1116 (((u_char *)&sa4->sin_addr)[0] == 172 && 1117 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1118 (((u_char *)&sa4->sin_addr)[0] == 192 && 1119 ((u_char *)&sa4->sin_addr)[1] == 168)) 1120 return(14); /* XXX: It should be 5 unless NAT */ 1121 /* Loopback addresses have link-local scope. */ 1122 if (((u_char *)&sa4->sin_addr)[0] == 127) 1123 return(2); 1124 return(14); 1125 break; 1126 default: 1127 errno = EAFNOSUPPORT; /* is this a good error? */ 1128 return(-1); 1129 } 1130 } 1131 #endif 1132