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 __FBSDID("$FreeBSD$"); 90 91 #include "namespace.h" 92 #include <sys/param.h> 93 #include <sys/socket.h> 94 #include <sys/time.h> 95 #include <sys/queue.h> 96 #include <netinet/in.h> 97 #ifdef INET6 98 #include <net/if.h> 99 #include <sys/sysctl.h> 100 #include <sys/ioctl.h> 101 #include <netinet6/in6_var.h> /* XXX */ 102 #endif 103 104 #include <arpa/inet.h> 105 #include <arpa/nameser.h> 106 107 #include <errno.h> 108 #include <netdb.h> 109 #include <resolv.h> 110 #include <stdio.h> 111 #include <stdlib.h> 112 #include <string.h> 113 #include <stdarg.h> 114 #include <nsswitch.h> 115 #include <unistd.h> 116 #include "un-namespace.h" 117 #include "netdb_private.h" 118 #include "res_private.h" 119 120 #ifndef MAXALIASES 121 #define MAXALIASES 10 122 #endif 123 #ifndef MAXADDRS 124 #define MAXADDRS 20 125 #endif 126 #ifndef MAXDNAME 127 #define MAXDNAME 1025 128 #endif 129 130 #ifdef INET6 131 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 132 sizeof(struct in_addr)) 133 #else 134 #define ADDRLEN(af) sizeof(struct in_addr) 135 #endif 136 137 #define MAPADDR(ab, ina) \ 138 do { \ 139 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 140 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 141 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 142 } while (0) 143 #define MAPADDRENABLED(flags) \ 144 (((flags) & AI_V4MAPPED) || \ 145 (((flags) & AI_V4MAPPED_CFG))) 146 147 union inx_addr { 148 struct in_addr in_addr; 149 #ifdef INET6 150 struct in6_addr in6_addr; 151 #endif 152 struct { 153 u_char mau_zero[10]; 154 u_char mau_one[2]; 155 struct in_addr mau_inaddr; 156 } map_addr_un; 157 #define map_zero map_addr_un.mau_zero 158 #define map_one map_addr_un.mau_one 159 #define map_inaddr map_addr_un.mau_inaddr 160 }; 161 162 struct policyqueue { 163 TAILQ_ENTRY(policyqueue) pc_entry; 164 #ifdef INET6 165 struct in6_addrpolicy pc_policy; 166 #endif 167 }; 168 TAILQ_HEAD(policyhead, policyqueue); 169 170 #define AIO_SRCFLAG_DEPRECATED 0x1 171 172 struct hp_order { 173 union { 174 struct sockaddr_storage aiou_ss; 175 struct sockaddr aiou_sa; 176 } aio_src_un; 177 #define aio_srcsa aio_src_un.aiou_sa 178 u_int32_t aio_srcflag; 179 int aio_srcscope; 180 int aio_dstscope; 181 struct policyqueue *aio_srcpolicy; 182 struct policyqueue *aio_dstpolicy; 183 union { 184 struct sockaddr_storage aiou_ss; 185 struct sockaddr aiou_sa; 186 } aio_un; 187 #define aio_sa aio_un.aiou_sa 188 int aio_matchlen; 189 char *aio_h_addr; 190 int aio_initial_sequence; 191 }; 192 193 static struct hostent *_hpcopy(struct hostent *, int *); 194 static struct hostent *_hpaddr(int, const char *, void *, int *); 195 #ifdef INET6 196 static struct hostent *_hpmerge(struct hostent *, struct hostent *, int *); 197 static struct hostent *_hpmapv6(struct hostent *, int *); 198 #endif 199 static struct hostent *_hpsort(struct hostent *, res_state); 200 201 #ifdef INET6 202 static struct hostent *_hpreorder(struct hostent *); 203 static int get_addrselectpolicy(struct policyhead *); 204 static void free_addrselectpolicy(struct policyhead *); 205 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 206 struct policyhead *); 207 static void set_source(struct hp_order *, struct policyhead *); 208 static int matchlen(struct sockaddr *, struct sockaddr *); 209 static int comp_dst(const void *, const void *); 210 static int gai_addr2scopetype(struct sockaddr *); 211 #endif 212 213 /* 214 * Functions defined in RFC2553 215 * getipnodebyname, getipnodebyaddr, freehostent 216 */ 217 218 struct hostent * 219 getipnodebyname(const char *name, int af, int flags, int *errp) 220 { 221 struct hostent *hp; 222 union inx_addr addrbuf; 223 res_state statp; 224 u_long options; 225 226 switch (af) { 227 case AF_INET: 228 #ifdef INET6 229 case AF_INET6: 230 #endif 231 break; 232 default: 233 *errp = NO_RECOVERY; 234 return NULL; 235 } 236 237 if (flags & AI_ADDRCONFIG) { 238 int s; 239 240 if ((s = _socket(af, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 241 return NULL; 242 /* 243 * TODO: 244 * Note that implementation dependent test for address 245 * configuration should be done every time called 246 * (or appropriate interval), 247 * because addresses will be dynamically assigned or deleted. 248 */ 249 _close(s); 250 } 251 252 #ifdef INET6 253 /* special case for literal address */ 254 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 255 if (af != AF_INET6) { 256 *errp = HOST_NOT_FOUND; 257 return NULL; 258 } 259 return _hpaddr(af, name, &addrbuf, errp); 260 } 261 #endif 262 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 263 if (af != AF_INET) { 264 if (MAPADDRENABLED(flags)) { 265 MAPADDR(&addrbuf, &addrbuf.in_addr); 266 } else { 267 *errp = HOST_NOT_FOUND; 268 return NULL; 269 } 270 } 271 return _hpaddr(af, name, &addrbuf, errp); 272 } 273 274 275 statp = __res_state(); 276 if ((statp->options & RES_INIT) == 0) { 277 if (res_ninit(statp) < 0) { 278 *errp = NETDB_INTERNAL; 279 return NULL; 280 } 281 } 282 283 options = statp->options; 284 statp->options &= ~RES_USE_INET6; 285 286 hp = gethostbyname2(name, af); 287 hp = _hpcopy(hp, errp); 288 #ifdef INET6 289 if (af == AF_INET6) 290 hp = _hpreorder(hp); 291 292 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 return _hpsort(hp, statp); 315 } 316 317 struct hostent * 318 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 319 { 320 struct hostent *hp; 321 res_state statp; 322 u_long options; 323 324 #ifdef INET6 325 struct in6_addr addrbuf; 326 #else 327 struct in_addr addrbuf; 328 #endif 329 330 switch (af) { 331 case AF_INET: 332 if (len != sizeof(struct in_addr)) { 333 *errp = NO_RECOVERY; 334 return NULL; 335 } 336 if (rounddown2((long)src, sizeof(struct in_addr))) { 337 memcpy(&addrbuf, src, len); 338 src = &addrbuf; 339 } 340 if (((struct in_addr *)src)->s_addr == 0) 341 return NULL; 342 break; 343 #ifdef INET6 344 case AF_INET6: 345 if (len != sizeof(struct in6_addr)) { 346 *errp = NO_RECOVERY; 347 return NULL; 348 } 349 if (rounddown2((long)src, sizeof(struct in6_addr) / 2)) { 350 /* XXX */ 351 memcpy(&addrbuf, src, len); 352 src = &addrbuf; 353 } 354 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 355 return NULL; 356 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 357 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 358 src = (char *)src + 359 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 360 af = AF_INET; 361 len = sizeof(struct in_addr); 362 } 363 break; 364 #endif 365 default: 366 *errp = NO_RECOVERY; 367 return NULL; 368 } 369 370 statp = __res_state(); 371 if ((statp->options & RES_INIT) == 0) { 372 if (res_ninit(statp) < 0) { 373 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 374 return NULL; 375 } 376 } 377 378 options = statp->options; 379 statp->options &= ~RES_USE_INET6; 380 381 hp = gethostbyaddr(src, len, af); 382 if (hp == NULL) 383 *errp = statp->res_h_errno; 384 385 statp->options = options; 386 return (_hpcopy(hp, errp)); 387 } 388 389 void 390 freehostent(struct hostent *ptr) 391 { 392 free(ptr); 393 } 394 395 /* 396 * Private utility functions 397 */ 398 399 /* 400 * _hpcopy: allocate and copy hostent structure 401 */ 402 static struct hostent * 403 _hpcopy(struct hostent *hp, int *errp) 404 { 405 struct hostent *nhp; 406 char *cp, **pp; 407 int size, addrsize; 408 int nalias = 0, naddr = 0; 409 int al_off; 410 int i; 411 412 if (hp == NULL) 413 return hp; 414 415 /* count size to be allocated */ 416 size = sizeof(struct hostent); 417 if (hp->h_name != NULL) 418 size += strlen(hp->h_name) + 1; 419 if ((pp = hp->h_aliases) != NULL) { 420 for (i = 0; *pp != NULL; i++, pp++) { 421 if (**pp != '\0') { 422 size += strlen(*pp) + 1; 423 nalias++; 424 } 425 } 426 } 427 /* adjust alignment */ 428 size = ALIGN(size); 429 al_off = size; 430 size += sizeof(char *) * (nalias + 1); 431 addrsize = ALIGN(hp->h_length); 432 if ((pp = hp->h_addr_list) != NULL) { 433 while (*pp++ != NULL) 434 naddr++; 435 } 436 size += addrsize * naddr; 437 size += sizeof(char *) * (naddr + 1); 438 439 /* copy */ 440 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 441 *errp = TRY_AGAIN; 442 return NULL; 443 } 444 cp = (char *)&nhp[1]; 445 if (hp->h_name != NULL) { 446 nhp->h_name = cp; 447 strcpy(cp, hp->h_name); 448 cp += strlen(cp) + 1; 449 } else 450 nhp->h_name = NULL; 451 nhp->h_aliases = (char **)((char *)nhp + al_off); 452 if ((pp = hp->h_aliases) != NULL) { 453 for (i = 0; *pp != NULL; pp++) { 454 if (**pp != '\0') { 455 nhp->h_aliases[i++] = cp; 456 strcpy(cp, *pp); 457 cp += strlen(cp) + 1; 458 } 459 } 460 } 461 nhp->h_aliases[nalias] = NULL; 462 cp = (char *)&nhp->h_aliases[nalias + 1]; 463 nhp->h_addrtype = hp->h_addrtype; 464 nhp->h_length = hp->h_length; 465 nhp->h_addr_list = (char **)cp; 466 if ((pp = hp->h_addr_list) != NULL) { 467 cp = (char *)&nhp->h_addr_list[naddr + 1]; 468 for (i = 0; *pp != NULL; pp++) { 469 nhp->h_addr_list[i++] = cp; 470 memcpy(cp, *pp, hp->h_length); 471 cp += addrsize; 472 } 473 } 474 nhp->h_addr_list[naddr] = NULL; 475 return nhp; 476 } 477 478 /* 479 * _hpaddr: construct hostent structure with one address 480 */ 481 static struct hostent * 482 _hpaddr(int af, const char *name, void *addr, int *errp) 483 { 484 struct hostent *hp, hpbuf; 485 char *addrs[2]; 486 487 hp = &hpbuf; 488 hp->h_name = (char *)name; 489 hp->h_aliases = NULL; 490 hp->h_addrtype = af; 491 hp->h_length = ADDRLEN(af); 492 hp->h_addr_list = addrs; 493 addrs[0] = (char *)addr; 494 addrs[1] = NULL; 495 return (_hpcopy(hp, errp)); 496 } 497 498 #ifdef INET6 499 /* 500 * _hpmerge: merge 2 hostent structure, arguments will be freed 501 */ 502 static struct hostent * 503 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 504 { 505 int i, j; 506 int naddr, nalias; 507 char **pp; 508 struct hostent *hp, hpbuf; 509 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 510 union inx_addr addrbuf[MAXADDRS]; 511 512 if (hp1 == NULL) 513 return _hpcopy(hp2, errp); 514 if (hp2 == NULL) 515 return _hpcopy(hp1, errp); 516 517 #define HP(i) (i == 1 ? hp1 : hp2) 518 hp = &hpbuf; 519 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 520 hp->h_aliases = aliases; 521 nalias = 0; 522 for (i = 1; i <= 2; i++) { 523 if ((pp = HP(i)->h_aliases) == NULL) 524 continue; 525 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 526 /* check duplicates */ 527 for (j = 0; j < nalias; j++) 528 if (strcasecmp(*pp, aliases[j]) == 0) 529 break; 530 if (j == nalias) 531 aliases[nalias++] = *pp; 532 } 533 } 534 aliases[nalias] = NULL; 535 if (hp1->h_length != hp2->h_length) { 536 hp->h_addrtype = AF_INET6; 537 hp->h_length = sizeof(struct in6_addr); 538 } else { 539 hp->h_addrtype = hp1->h_addrtype; 540 hp->h_length = hp1->h_length; 541 } 542 543 hp->h_addr_list = addrs; 544 naddr = 0; 545 for (i = 1; i <= 2; i++) { 546 if ((pp = HP(i)->h_addr_list) == NULL) 547 continue; 548 if (HP(i)->h_length == hp->h_length) { 549 while (naddr < MAXADDRS && *pp != NULL) 550 addrs[naddr++] = *pp++; 551 } else { 552 /* copy IPv4 addr as mapped IPv6 addr */ 553 while (naddr < MAXADDRS && *pp != NULL) { 554 MAPADDR(&addrbuf[naddr], *pp++); 555 addrs[naddr] = (char *)&addrbuf[naddr]; 556 naddr++; 557 } 558 } 559 } 560 addrs[naddr] = NULL; 561 return (_hpcopy(hp, errp)); 562 } 563 #endif 564 565 /* 566 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 567 */ 568 #ifdef INET6 569 static struct hostent * 570 _hpmapv6(struct hostent *hp, int *errp) 571 { 572 struct hostent hp6; 573 574 if (hp == NULL) 575 return NULL; 576 if (hp->h_addrtype == AF_INET6) 577 return _hpcopy(hp, errp); 578 579 memset(&hp6, 0, sizeof(struct hostent)); 580 hp6.h_addrtype = AF_INET6; 581 hp6.h_length = sizeof(struct in6_addr); 582 return _hpmerge(&hp6, hp, errp); 583 } 584 #endif 585 586 /* 587 * _hpsort: sort address by sortlist 588 */ 589 static struct hostent * 590 _hpsort(struct hostent *hp, res_state statp) 591 { 592 int i, j, n; 593 u_char *ap, *sp, *mp, **pp; 594 char t; 595 char order[MAXADDRS]; 596 int nsort = statp->nsort; 597 598 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 599 return hp; 600 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 601 for (j = 0; j < nsort; j++) { 602 #ifdef INET6 603 if (statp->_u._ext.ext->sort_list[j].af != 604 hp->h_addrtype) 605 continue; 606 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr; 607 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask; 608 #else 609 sp = (u_char *)&statp->sort_list[j].addr; 610 mp = (u_char *)&statp->sort_list[j].mask; 611 #endif 612 for (n = 0; n < hp->h_length; n++) { 613 if ((ap[n] & mp[n]) != sp[n]) 614 break; 615 } 616 if (n == hp->h_length) 617 break; 618 } 619 order[i] = j; 620 } 621 n = i; 622 pp = (u_char **)hp->h_addr_list; 623 for (i = 0; i < n - 1; i++) { 624 for (j = i + 1; j < n; j++) { 625 if (order[i] > order[j]) { 626 ap = pp[i]; 627 pp[i] = pp[j]; 628 pp[j] = ap; 629 t = order[i]; 630 order[i] = order[j]; 631 order[j] = t; 632 } 633 } 634 } 635 return hp; 636 } 637 638 #ifdef INET6 639 /* 640 * _hpreorder: sort address by default address selection 641 */ 642 static struct hostent * 643 _hpreorder(struct hostent *hp) 644 { 645 struct hp_order *aio; 646 int i, n; 647 char *ap; 648 struct sockaddr *sa; 649 struct policyhead policyhead; 650 651 if (hp == NULL) 652 return hp; 653 654 switch (hp->h_addrtype) { 655 case AF_INET: 656 #ifdef INET6 657 case AF_INET6: 658 #endif 659 break; 660 default: 661 return hp; 662 } 663 664 /* count the number of addrinfo elements for sorting. */ 665 for (n = 0; hp->h_addr_list[n] != NULL; n++) 666 ; 667 668 /* 669 * If the number is small enough, we can skip the reordering process. 670 */ 671 if (n <= 1) 672 return hp; 673 674 /* allocate a temporary array for sort and initialization of it. */ 675 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 676 return hp; /* give up reordering */ 677 memset(aio, 0, sizeof(*aio) * n); 678 679 /* retrieve address selection policy from the kernel */ 680 TAILQ_INIT(&policyhead); 681 if (!get_addrselectpolicy(&policyhead)) { 682 /* no policy is installed into kernel, we don't sort. */ 683 free(aio); 684 return hp; 685 } 686 687 for (i = 0; i < n; i++) { 688 ap = hp->h_addr_list[i]; 689 aio[i].aio_h_addr = ap; 690 sa = &aio[i].aio_sa; 691 switch (hp->h_addrtype) { 692 case AF_INET: 693 sa->sa_family = AF_INET; 694 sa->sa_len = sizeof(struct sockaddr_in); 695 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap, 696 sizeof(struct in_addr)); 697 break; 698 #ifdef INET6 699 case AF_INET6: 700 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) { 701 sa->sa_family = AF_INET; 702 sa->sa_len = sizeof(struct sockaddr_in); 703 memcpy(&((struct sockaddr_in *)sa)->sin_addr, 704 &ap[12], sizeof(struct in_addr)); 705 } else { 706 sa->sa_family = AF_INET6; 707 sa->sa_len = sizeof(struct sockaddr_in6); 708 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr, 709 ap, sizeof(struct in6_addr)); 710 } 711 break; 712 #endif 713 } 714 aio[i].aio_dstscope = gai_addr2scopetype(sa); 715 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead); 716 set_source(&aio[i], &policyhead); 717 aio[i].aio_initial_sequence = i; 718 } 719 720 /* perform sorting. */ 721 qsort(aio, n, sizeof(*aio), comp_dst); 722 723 /* reorder the h_addr_list. */ 724 for (i = 0; i < n; i++) 725 hp->h_addr_list[i] = aio[i].aio_h_addr; 726 727 /* cleanup and return */ 728 free(aio); 729 free_addrselectpolicy(&policyhead); 730 return hp; 731 } 732 733 static int 734 get_addrselectpolicy(struct policyhead *head) 735 { 736 #ifdef INET6 737 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 738 size_t l; 739 char *buf; 740 struct in6_addrpolicy *pol, *ep; 741 742 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) 743 return (0); 744 if ((buf = malloc(l)) == NULL) 745 return (0); 746 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 747 free(buf); 748 return (0); 749 } 750 751 ep = (struct in6_addrpolicy *)(buf + l); 752 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 753 struct policyqueue *new; 754 755 if ((new = malloc(sizeof(*new))) == NULL) { 756 free_addrselectpolicy(head); /* make the list empty */ 757 break; 758 } 759 new->pc_policy = *pol; 760 TAILQ_INSERT_TAIL(head, new, pc_entry); 761 } 762 763 free(buf); 764 return (1); 765 #else 766 return (0); 767 #endif 768 } 769 770 static void 771 free_addrselectpolicy(struct policyhead *head) 772 { 773 struct policyqueue *ent, *nent; 774 775 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 776 nent = TAILQ_NEXT(ent, pc_entry); 777 TAILQ_REMOVE(head, ent, pc_entry); 778 free(ent); 779 } 780 } 781 782 static struct policyqueue * 783 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 784 { 785 #ifdef INET6 786 struct policyqueue *ent, *bestent = NULL; 787 struct in6_addrpolicy *pol; 788 int matchlen, bestmatchlen = -1; 789 u_char *mp, *ep, *k, *p, m; 790 struct sockaddr_in6 key; 791 792 switch(addr->sa_family) { 793 case AF_INET6: 794 key = *(struct sockaddr_in6 *)addr; 795 break; 796 case AF_INET: 797 /* convert the address into IPv4-mapped IPv6 address. */ 798 memset(&key, 0, sizeof(key)); 799 key.sin6_family = AF_INET6; 800 key.sin6_len = sizeof(key); 801 _map_v4v6_address( 802 (char *)&((struct sockaddr_in *)addr)->sin_addr, 803 (char *)&key.sin6_addr); 804 break; 805 default: 806 return(NULL); 807 } 808 809 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 810 pol = &ent->pc_policy; 811 matchlen = 0; 812 813 mp = (u_char *)&pol->addrmask.sin6_addr; 814 ep = mp + 16; /* XXX: scope field? */ 815 k = (u_char *)&key.sin6_addr; 816 p = (u_char *)&pol->addr.sin6_addr; 817 for (; mp < ep && *mp; mp++, k++, p++) { 818 m = *mp; 819 if ((*k & m) != *p) 820 goto next; /* not match */ 821 if (m == 0xff) /* short cut for a typical case */ 822 matchlen += 8; 823 else { 824 while (m >= 0x80) { 825 matchlen++; 826 m <<= 1; 827 } 828 } 829 } 830 831 /* matched. check if this is better than the current best. */ 832 if (matchlen > bestmatchlen) { 833 bestent = ent; 834 bestmatchlen = matchlen; 835 } 836 837 next: 838 continue; 839 } 840 841 return(bestent); 842 #else 843 return(NULL); 844 #endif 845 846 } 847 848 static void 849 set_source(struct hp_order *aio, struct policyhead *ph) 850 { 851 struct sockaddr_storage ss = aio->aio_un.aiou_ss; 852 socklen_t srclen; 853 int s; 854 855 /* set unspec ("no source is available"), just in case */ 856 aio->aio_srcsa.sa_family = AF_UNSPEC; 857 aio->aio_srcscope = -1; 858 859 switch(ss.ss_family) { 860 case AF_INET: 861 ((struct sockaddr_in *)&ss)->sin_port = htons(1); 862 break; 863 #ifdef INET6 864 case AF_INET6: 865 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1); 866 break; 867 #endif 868 default: /* ignore unsupported AFs explicitly */ 869 return; 870 } 871 872 /* open a socket to get the source address for the given dst */ 873 if ((s = _socket(ss.ss_family, SOCK_DGRAM | SOCK_CLOEXEC, 874 IPPROTO_UDP)) < 0) 875 return; /* give up */ 876 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0) 877 goto cleanup; 878 srclen = ss.ss_len; 879 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 880 aio->aio_srcsa.sa_family = AF_UNSPEC; 881 goto cleanup; 882 } 883 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 884 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 885 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss); 886 #ifdef INET6 887 if (ss.ss_family == AF_INET6) { 888 struct in6_ifreq ifr6; 889 u_int32_t flags6; 890 891 memset(&ifr6, 0, sizeof(ifr6)); 892 memcpy(&ifr6.ifr_addr, &ss, ss.ss_len); 893 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 894 flags6 = ifr6.ifr_ifru.ifru_flags6; 895 if ((flags6 & IN6_IFF_DEPRECATED)) 896 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 897 } 898 } 899 #endif 900 901 cleanup: 902 _close(s); 903 return; 904 } 905 906 static int 907 matchlen(struct sockaddr *src, struct sockaddr *dst) 908 { 909 int match = 0; 910 u_char *s, *d; 911 u_char *lim, r; 912 int addrlen; 913 914 switch (src->sa_family) { 915 #ifdef INET6 916 case AF_INET6: 917 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 918 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 919 addrlen = sizeof(struct in6_addr); 920 lim = s + addrlen; 921 break; 922 #endif 923 case AF_INET: 924 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 925 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 926 addrlen = sizeof(struct in_addr); 927 lim = s + addrlen; 928 break; 929 default: 930 return(0); 931 } 932 933 while (s < lim) 934 if ((r = (*d++ ^ *s++)) != 0) { 935 while ((r & 0x80) == 0) { 936 match++; 937 r <<= 1; 938 } 939 break; 940 } else 941 match += 8; 942 return(match); 943 } 944 945 static int 946 comp_dst(const void *arg1, const void *arg2) 947 { 948 const struct hp_order *dst1 = arg1, *dst2 = arg2; 949 950 /* 951 * Rule 1: Avoid unusable destinations. 952 * XXX: we currently do not consider if an appropriate route exists. 953 */ 954 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 955 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 956 return(-1); 957 } 958 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 959 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 960 return(1); 961 } 962 963 /* Rule 2: Prefer matching scope. */ 964 if (dst1->aio_dstscope == dst1->aio_srcscope && 965 dst2->aio_dstscope != dst2->aio_srcscope) { 966 return(-1); 967 } 968 if (dst1->aio_dstscope != dst1->aio_srcscope && 969 dst2->aio_dstscope == dst2->aio_srcscope) { 970 return(1); 971 } 972 973 /* Rule 3: Avoid deprecated addresses. */ 974 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 975 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 976 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 977 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 978 return(-1); 979 } 980 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 981 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 982 return(1); 983 } 984 } 985 986 /* Rule 4: Prefer home addresses. */ 987 /* XXX: not implemented yet */ 988 989 /* Rule 5: Prefer matching label. */ 990 #ifdef INET6 991 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 992 dst1->aio_srcpolicy->pc_policy.label == 993 dst1->aio_dstpolicy->pc_policy.label && 994 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 995 dst2->aio_srcpolicy->pc_policy.label != 996 dst2->aio_dstpolicy->pc_policy.label)) { 997 return(-1); 998 } 999 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 1000 dst2->aio_srcpolicy->pc_policy.label == 1001 dst2->aio_dstpolicy->pc_policy.label && 1002 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1003 dst1->aio_srcpolicy->pc_policy.label != 1004 dst1->aio_dstpolicy->pc_policy.label)) { 1005 return(1); 1006 } 1007 #endif 1008 1009 /* Rule 6: Prefer higher precedence. */ 1010 #ifdef INET6 1011 if (dst1->aio_dstpolicy && 1012 (dst2->aio_dstpolicy == NULL || 1013 dst1->aio_dstpolicy->pc_policy.preced > 1014 dst2->aio_dstpolicy->pc_policy.preced)) { 1015 return(-1); 1016 } 1017 if (dst2->aio_dstpolicy && 1018 (dst1->aio_dstpolicy == NULL || 1019 dst2->aio_dstpolicy->pc_policy.preced > 1020 dst1->aio_dstpolicy->pc_policy.preced)) { 1021 return(1); 1022 } 1023 #endif 1024 1025 /* Rule 7: Prefer native transport. */ 1026 /* XXX: not implemented yet */ 1027 1028 /* Rule 8: Prefer smaller scope. */ 1029 if (dst1->aio_dstscope >= 0 && 1030 dst1->aio_dstscope < dst2->aio_dstscope) { 1031 return(-1); 1032 } 1033 if (dst2->aio_dstscope >= 0 && 1034 dst2->aio_dstscope < dst1->aio_dstscope) { 1035 return(1); 1036 } 1037 1038 /* 1039 * Rule 9: Use longest matching prefix. 1040 * We compare the match length in a same AF only. 1041 */ 1042 if (dst1->aio_sa.sa_family == dst2->aio_sa.sa_family) { 1043 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1044 return(-1); 1045 } 1046 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1047 return(1); 1048 } 1049 } 1050 1051 /* Rule 10: Otherwise, leave the order unchanged. */ 1052 1053 /* 1054 * Note that qsort is unstable; so, we can't return zero and 1055 * expect the order to be unchanged. 1056 * That also means we can't depend on the current position of 1057 * dst2 being after dst1. We must enforce the initial order 1058 * with an explicit compare on the original position. 1059 * The qsort specification requires that "When the same objects 1060 * (consisting of width bytes, irrespective of their current 1061 * positions in the array) are passed more than once to the 1062 * comparison function, the results shall be consistent with one 1063 * another." 1064 * In other words, If A < B, then we must also return B > A. 1065 */ 1066 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1067 return(1); 1068 1069 return(-1); 1070 } 1071 1072 /* 1073 * Copy from scope.c. 1074 * XXX: we should standardize the functions and link them as standard 1075 * library. 1076 */ 1077 static int 1078 gai_addr2scopetype(struct sockaddr *sa) 1079 { 1080 #ifdef INET6 1081 struct sockaddr_in6 *sa6; 1082 #endif 1083 struct sockaddr_in *sa4; 1084 1085 switch(sa->sa_family) { 1086 #ifdef INET6 1087 case AF_INET6: 1088 sa6 = (struct sockaddr_in6 *)sa; 1089 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1090 /* just use the scope field of the multicast address */ 1091 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1092 } 1093 /* 1094 * Unicast addresses: map scope type to corresponding scope 1095 * value defined for multcast addresses. 1096 * XXX: hardcoded scope type values are bad... 1097 */ 1098 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1099 return(1); /* node local scope */ 1100 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1101 return(2); /* link-local scope */ 1102 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1103 return(5); /* site-local scope */ 1104 return(14); /* global scope */ 1105 break; 1106 #endif 1107 case AF_INET: 1108 /* 1109 * IPv4 pseudo scoping according to RFC 3484. 1110 */ 1111 sa4 = (struct sockaddr_in *)sa; 1112 /* IPv4 autoconfiguration addresses have link-local scope. */ 1113 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1114 ((u_char *)&sa4->sin_addr)[1] == 254) 1115 return(2); 1116 /* Private addresses have site-local scope. */ 1117 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1118 (((u_char *)&sa4->sin_addr)[0] == 172 && 1119 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1120 (((u_char *)&sa4->sin_addr)[0] == 192 && 1121 ((u_char *)&sa4->sin_addr)[1] == 168)) 1122 return(14); /* XXX: It should be 5 unless NAT */ 1123 /* Loopback addresses have link-local scope. */ 1124 if (((u_char *)&sa4->sin_addr)[0] == 127) 1125 return(2); 1126 return(14); 1127 break; 1128 default: 1129 errno = EAFNOSUPPORT; /* is this a good error? */ 1130 return(-1); 1131 } 1132 } 1133 #endif 1134