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. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * - 61 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 62 * 63 * Permission to use, copy, modify, and distribute this software for any 64 * purpose with or without fee is hereby granted, provided that the above 65 * copyright notice and this permission notice appear in all copies, and that 66 * the name of Digital Equipment Corporation not be used in advertising or 67 * publicity pertaining to distribution of the document or software without 68 * specific, written prior permission. 69 * 70 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 71 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 72 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 73 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 74 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 75 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 76 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 77 * SOFTWARE. 78 * - 79 * --Copyright-- 80 */ 81 82 /* 83 * Atsushi Onoe <onoe@sm.sony.co.jp> 84 */ 85 86 #include <sys/cdefs.h> 87 __FBSDID("$FreeBSD$"); 88 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 <net/if_var.h> 98 #include <sys/sysctl.h> 99 #include <sys/ioctl.h> 100 #include <netinet6/in6_var.h> /* XXX */ 101 #endif 102 103 #include <arpa/inet.h> 104 #include <arpa/nameser.h> 105 106 #include <errno.h> 107 #include <netdb.h> 108 #include <resolv.h> 109 #include <stdio.h> 110 #include <stdlib.h> 111 #include <string.h> 112 #include <stdarg.h> 113 #include <nsswitch.h> 114 #include <unistd.h> 115 #include "un-namespace.h" 116 #include "netdb_private.h" 117 #include "res_private.h" 118 119 #ifndef MAXALIASES 120 #define MAXALIASES 10 121 #endif 122 #ifndef MAXADDRS 123 #define MAXADDRS 20 124 #endif 125 #ifndef MAXDNAME 126 #define MAXDNAME 1025 127 #endif 128 129 #ifdef INET6 130 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 131 sizeof(struct in_addr)) 132 #else 133 #define ADDRLEN(af) sizeof(struct in_addr) 134 #endif 135 136 #define MAPADDR(ab, ina) \ 137 do { \ 138 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 139 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 140 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 141 } while (0) 142 #define MAPADDRENABLED(flags) \ 143 (((flags) & AI_V4MAPPED) || \ 144 (((flags) & AI_V4MAPPED_CFG))) 145 146 union inx_addr { 147 struct in_addr in_addr; 148 #ifdef INET6 149 struct in6_addr in6_addr; 150 #endif 151 struct { 152 u_char mau_zero[10]; 153 u_char mau_one[2]; 154 struct in_addr mau_inaddr; 155 } map_addr_un; 156 #define map_zero map_addr_un.mau_zero 157 #define map_one map_addr_un.mau_one 158 #define map_inaddr map_addr_un.mau_inaddr 159 }; 160 161 struct policyqueue { 162 TAILQ_ENTRY(policyqueue) pc_entry; 163 #ifdef INET6 164 struct in6_addrpolicy pc_policy; 165 #endif 166 }; 167 TAILQ_HEAD(policyhead, policyqueue); 168 169 #define AIO_SRCFLAG_DEPRECATED 0x1 170 171 struct hp_order { 172 union { 173 struct sockaddr_storage aiou_ss; 174 struct sockaddr aiou_sa; 175 } aio_src_un; 176 #define aio_srcsa aio_src_un.aiou_sa 177 u_int32_t aio_srcflag; 178 int aio_srcscope; 179 int aio_dstscope; 180 struct policyqueue *aio_srcpolicy; 181 struct policyqueue *aio_dstpolicy; 182 union { 183 struct sockaddr_storage aiou_ss; 184 struct sockaddr aiou_sa; 185 } aio_un; 186 #define aio_sa aio_un.aiou_sa 187 int aio_matchlen; 188 char *aio_h_addr; 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 everytime called 244 * (or apropriate 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 ((long)src & ~(sizeof(struct in_addr) - 1)) { 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 ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 348 memcpy(&addrbuf, src, len); 349 src = &addrbuf; 350 } 351 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 352 return NULL; 353 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 354 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 355 src = (char *)src + 356 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 357 af = AF_INET; 358 len = sizeof(struct in_addr); 359 } 360 break; 361 #endif 362 default: 363 *errp = NO_RECOVERY; 364 return NULL; 365 } 366 367 statp = __res_state(); 368 if ((statp->options & RES_INIT) == 0) { 369 if (res_ninit(statp) < 0) { 370 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 371 return NULL; 372 } 373 } 374 375 options = statp->options; 376 statp->options &= ~RES_USE_INET6; 377 378 hp = gethostbyaddr(src, len, af); 379 if (hp == NULL) 380 *errp = statp->res_h_errno; 381 382 statp->options = options; 383 return (_hpcopy(hp, errp)); 384 } 385 386 void 387 freehostent(struct hostent *ptr) 388 { 389 free(ptr); 390 } 391 392 /* 393 * Private utility functions 394 */ 395 396 /* 397 * _hpcopy: allocate and copy hostent structure 398 */ 399 static struct hostent * 400 _hpcopy(struct hostent *hp, int *errp) 401 { 402 struct hostent *nhp; 403 char *cp, **pp; 404 int size, addrsize; 405 int nalias = 0, naddr = 0; 406 int al_off; 407 int i; 408 409 if (hp == NULL) 410 return hp; 411 412 /* count size to be allocated */ 413 size = sizeof(struct hostent); 414 if (hp->h_name != NULL) 415 size += strlen(hp->h_name) + 1; 416 if ((pp = hp->h_aliases) != NULL) { 417 for (i = 0; *pp != NULL; i++, pp++) { 418 if (**pp != '\0') { 419 size += strlen(*pp) + 1; 420 nalias++; 421 } 422 } 423 } 424 /* adjust alignment */ 425 size = ALIGN(size); 426 al_off = size; 427 size += sizeof(char *) * (nalias + 1); 428 addrsize = ALIGN(hp->h_length); 429 if ((pp = hp->h_addr_list) != NULL) { 430 while (*pp++ != NULL) 431 naddr++; 432 } 433 size += addrsize * naddr; 434 size += sizeof(char *) * (naddr + 1); 435 436 /* copy */ 437 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 438 *errp = TRY_AGAIN; 439 return NULL; 440 } 441 cp = (char *)&nhp[1]; 442 if (hp->h_name != NULL) { 443 nhp->h_name = cp; 444 strcpy(cp, hp->h_name); 445 cp += strlen(cp) + 1; 446 } else 447 nhp->h_name = NULL; 448 nhp->h_aliases = (char **)((char *)nhp + al_off); 449 if ((pp = hp->h_aliases) != NULL) { 450 for (i = 0; *pp != NULL; pp++) { 451 if (**pp != '\0') { 452 nhp->h_aliases[i++] = cp; 453 strcpy(cp, *pp); 454 cp += strlen(cp) + 1; 455 } 456 } 457 } 458 nhp->h_aliases[nalias] = NULL; 459 cp = (char *)&nhp->h_aliases[nalias + 1]; 460 nhp->h_addrtype = hp->h_addrtype; 461 nhp->h_length = hp->h_length; 462 nhp->h_addr_list = (char **)cp; 463 if ((pp = hp->h_addr_list) != NULL) { 464 cp = (char *)&nhp->h_addr_list[naddr + 1]; 465 for (i = 0; *pp != NULL; pp++) { 466 nhp->h_addr_list[i++] = cp; 467 memcpy(cp, *pp, hp->h_length); 468 cp += addrsize; 469 } 470 } 471 nhp->h_addr_list[naddr] = NULL; 472 return nhp; 473 } 474 475 /* 476 * _hpaddr: construct hostent structure with one address 477 */ 478 static struct hostent * 479 _hpaddr(int af, const char *name, void *addr, int *errp) 480 { 481 struct hostent *hp, hpbuf; 482 char *addrs[2]; 483 484 hp = &hpbuf; 485 hp->h_name = (char *)name; 486 hp->h_aliases = NULL; 487 hp->h_addrtype = af; 488 hp->h_length = ADDRLEN(af); 489 hp->h_addr_list = addrs; 490 addrs[0] = (char *)addr; 491 addrs[1] = NULL; 492 return (_hpcopy(hp, errp)); 493 } 494 495 #ifdef INET6 496 /* 497 * _hpmerge: merge 2 hostent structure, arguments will be freed 498 */ 499 static struct hostent * 500 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 501 { 502 int i, j; 503 int naddr, nalias; 504 char **pp; 505 struct hostent *hp, hpbuf; 506 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 507 union inx_addr addrbuf[MAXADDRS]; 508 509 if (hp1 == NULL) 510 return _hpcopy(hp2, errp); 511 if (hp2 == NULL) 512 return _hpcopy(hp1, errp); 513 514 #define HP(i) (i == 1 ? hp1 : hp2) 515 hp = &hpbuf; 516 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 517 hp->h_aliases = aliases; 518 nalias = 0; 519 for (i = 1; i <= 2; i++) { 520 if ((pp = HP(i)->h_aliases) == NULL) 521 continue; 522 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 523 /* check duplicates */ 524 for (j = 0; j < nalias; j++) 525 if (strcasecmp(*pp, aliases[j]) == 0) 526 break; 527 if (j == nalias) 528 aliases[nalias++] = *pp; 529 } 530 } 531 aliases[nalias] = NULL; 532 if (hp1->h_length != hp2->h_length) { 533 hp->h_addrtype = AF_INET6; 534 hp->h_length = sizeof(struct in6_addr); 535 } else { 536 hp->h_addrtype = hp1->h_addrtype; 537 hp->h_length = hp1->h_length; 538 } 539 540 hp->h_addr_list = addrs; 541 naddr = 0; 542 for (i = 1; i <= 2; i++) { 543 if ((pp = HP(i)->h_addr_list) == NULL) 544 continue; 545 if (HP(i)->h_length == hp->h_length) { 546 while (naddr < MAXADDRS && *pp != NULL) 547 addrs[naddr++] = *pp++; 548 } else { 549 /* copy IPv4 addr as mapped IPv6 addr */ 550 while (naddr < MAXADDRS && *pp != NULL) { 551 MAPADDR(&addrbuf[naddr], *pp++); 552 addrs[naddr] = (char *)&addrbuf[naddr]; 553 naddr++; 554 } 555 } 556 } 557 addrs[naddr] = NULL; 558 return (_hpcopy(hp, errp)); 559 } 560 #endif 561 562 /* 563 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 564 */ 565 #ifdef INET6 566 static struct hostent * 567 _hpmapv6(struct hostent *hp, int *errp) 568 { 569 struct hostent hp6; 570 571 if (hp == NULL) 572 return NULL; 573 if (hp->h_addrtype == AF_INET6) 574 return _hpcopy(hp, errp); 575 576 memset(&hp6, 0, sizeof(struct hostent)); 577 hp6.h_addrtype = AF_INET6; 578 hp6.h_length = sizeof(struct in6_addr); 579 return _hpmerge(&hp6, hp, errp); 580 } 581 #endif 582 583 /* 584 * _hpsort: sort address by sortlist 585 */ 586 static struct hostent * 587 _hpsort(struct hostent *hp, res_state statp) 588 { 589 int i, j, n; 590 u_char *ap, *sp, *mp, **pp; 591 char t; 592 char order[MAXADDRS]; 593 int nsort = statp->nsort; 594 595 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 596 return hp; 597 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 598 for (j = 0; j < nsort; j++) { 599 #ifdef INET6 600 if (statp->_u._ext.ext->sort_list[j].af != 601 hp->h_addrtype) 602 continue; 603 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr; 604 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask; 605 #else 606 sp = (u_char *)&statp->sort_list[j].addr; 607 mp = (u_char *)&statp->sort_list[j].mask; 608 #endif 609 for (n = 0; n < hp->h_length; n++) { 610 if ((ap[n] & mp[n]) != sp[n]) 611 break; 612 } 613 if (n == hp->h_length) 614 break; 615 } 616 order[i] = j; 617 } 618 n = i; 619 pp = (u_char **)hp->h_addr_list; 620 for (i = 0; i < n - 1; i++) { 621 for (j = i + 1; j < n; j++) { 622 if (order[i] > order[j]) { 623 ap = pp[i]; 624 pp[i] = pp[j]; 625 pp[j] = ap; 626 t = order[i]; 627 order[i] = order[j]; 628 order[j] = t; 629 } 630 } 631 } 632 return hp; 633 } 634 635 #ifdef INET6 636 /* 637 * _hpreorder: sort address by default address selection 638 */ 639 static struct hostent * 640 _hpreorder(struct hostent *hp) 641 { 642 struct hp_order *aio; 643 int i, n; 644 char *ap; 645 struct sockaddr *sa; 646 struct policyhead policyhead; 647 648 if (hp == NULL) 649 return hp; 650 651 switch (hp->h_addrtype) { 652 case AF_INET: 653 #ifdef INET6 654 case AF_INET6: 655 #endif 656 break; 657 default: 658 free_addrselectpolicy(&policyhead); 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 } 716 717 /* perform sorting. */ 718 qsort(aio, n, sizeof(*aio), comp_dst); 719 720 /* reorder the h_addr_list. */ 721 for (i = 0; i < n; i++) 722 hp->h_addr_list[i] = aio[i].aio_h_addr; 723 724 /* cleanup and return */ 725 free(aio); 726 free_addrselectpolicy(&policyhead); 727 return hp; 728 } 729 730 static int 731 get_addrselectpolicy(struct policyhead *head) 732 { 733 #ifdef INET6 734 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 735 size_t l; 736 char *buf; 737 struct in6_addrpolicy *pol, *ep; 738 739 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 740 return (0); 741 if ((buf = malloc(l)) == NULL) 742 return (0); 743 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 744 free(buf); 745 return (0); 746 } 747 748 ep = (struct in6_addrpolicy *)(buf + l); 749 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 750 struct policyqueue *new; 751 752 if ((new = malloc(sizeof(*new))) == NULL) { 753 free_addrselectpolicy(head); /* make the list empty */ 754 break; 755 } 756 new->pc_policy = *pol; 757 TAILQ_INSERT_TAIL(head, new, pc_entry); 758 } 759 760 free(buf); 761 return (1); 762 #else 763 return (0); 764 #endif 765 } 766 767 static void 768 free_addrselectpolicy(struct policyhead *head) 769 { 770 struct policyqueue *ent, *nent; 771 772 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 773 nent = TAILQ_NEXT(ent, pc_entry); 774 TAILQ_REMOVE(head, ent, pc_entry); 775 free(ent); 776 } 777 } 778 779 static struct policyqueue * 780 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 781 { 782 #ifdef INET6 783 struct policyqueue *ent, *bestent = NULL; 784 struct in6_addrpolicy *pol; 785 int matchlen, bestmatchlen = -1; 786 u_char *mp, *ep, *k, *p, m; 787 struct sockaddr_in6 key; 788 789 switch(addr->sa_family) { 790 case AF_INET6: 791 key = *(struct sockaddr_in6 *)addr; 792 break; 793 case AF_INET: 794 /* convert the address into IPv4-mapped IPv6 address. */ 795 memset(&key, 0, sizeof(key)); 796 key.sin6_family = AF_INET6; 797 key.sin6_len = sizeof(key); 798 key.sin6_addr.s6_addr[10] = 0xff; 799 key.sin6_addr.s6_addr[11] = 0xff; 800 memcpy(&key.sin6_addr.s6_addr[12], 801 &((struct sockaddr_in *)addr)->sin_addr, 4); 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 < addrlen * 8) { 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 return(-1); 1051 } 1052 1053 /* 1054 * Copy from scope.c. 1055 * XXX: we should standardize the functions and link them as standard 1056 * library. 1057 */ 1058 static int 1059 gai_addr2scopetype(struct sockaddr *sa) 1060 { 1061 #ifdef INET6 1062 struct sockaddr_in6 *sa6; 1063 #endif 1064 struct sockaddr_in *sa4; 1065 1066 switch(sa->sa_family) { 1067 #ifdef INET6 1068 case AF_INET6: 1069 sa6 = (struct sockaddr_in6 *)sa; 1070 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1071 /* just use the scope field of the multicast address */ 1072 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1073 } 1074 /* 1075 * Unicast addresses: map scope type to corresponding scope 1076 * value defined for multcast addresses. 1077 * XXX: hardcoded scope type values are bad... 1078 */ 1079 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1080 return(1); /* node local scope */ 1081 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1082 return(2); /* link-local scope */ 1083 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1084 return(5); /* site-local scope */ 1085 return(14); /* global scope */ 1086 break; 1087 #endif 1088 case AF_INET: 1089 /* 1090 * IPv4 pseudo scoping according to RFC 3484. 1091 */ 1092 sa4 = (struct sockaddr_in *)sa; 1093 /* IPv4 autoconfiguration addresses have link-local scope. */ 1094 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1095 ((u_char *)&sa4->sin_addr)[1] == 254) 1096 return(2); 1097 /* Private addresses have site-local scope. */ 1098 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1099 (((u_char *)&sa4->sin_addr)[0] == 172 && 1100 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1101 (((u_char *)&sa4->sin_addr)[0] == 192 && 1102 ((u_char *)&sa4->sin_addr)[1] == 168)) 1103 return(14); /* XXX: It should be 5 unless NAT */ 1104 /* Loopback addresses have link-local scope. */ 1105 if (((u_char *)&sa4->sin_addr)[0] == 127) 1106 return(2); 1107 return(14); 1108 break; 1109 default: 1110 errno = EAFNOSUPPORT; /* is this a good error? */ 1111 return(-1); 1112 } 1113 } 1114 #endif 1115