1 /* $FreeBSD$ */ 2 /* $KAME: name6.c,v 1.22 2000/05/01 08:19:08 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 /* 33 * ++Copyright++ 1985, 1988, 1993 34 * - 35 * Copyright (c) 1985, 1988, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * - 66 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 67 * 68 * Permission to use, copy, modify, and distribute this software for any 69 * purpose with or without fee is hereby granted, provided that the above 70 * copyright notice and this permission notice appear in all copies, and that 71 * the name of Digital Equipment Corporation not be used in advertising or 72 * publicity pertaining to distribution of the document or software without 73 * specific, written prior permission. 74 * 75 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 76 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 77 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 78 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 79 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 80 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 81 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 82 * SOFTWARE. 83 * - 84 * --Copyright-- 85 */ 86 87 /* 88 * Atsushi Onoe <onoe@sm.sony.co.jp> 89 */ 90 91 /* 92 * TODO for thread safe 93 * use mutex for _hostconf, _hostconf_init. 94 * rewrite resolvers to be thread safe 95 */ 96 97 #include <sys/param.h> 98 #include <sys/socket.h> 99 #include <sys/time.h> 100 #include <sys/queue.h> 101 #include <netinet/in.h> 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 <unistd.h> 113 114 #ifndef _PATH_HOSTS 115 #define _PATH_HOSTS "/etc/hosts" 116 #endif 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) && _mapped_addr_enabled())) 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 static struct hostent *_hpcopy(struct hostent *hp, int *errp); 161 static struct hostent *_hpaddr(int af, const char *name, void *addr, int *errp); 162 static struct hostent *_hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp); 163 #ifdef INET6 164 static struct hostent *_hpmapv6(struct hostent *hp, int *errp); 165 #endif 166 static struct hostent *_hpsort(struct hostent *hp); 167 static struct hostent *_ghbyname(const char *name, int af, int flags, int *errp); 168 static char *_hgetword(char **pp); 169 static int _mapped_addr_enabled(void); 170 171 static FILE *_files_open(int *errp); 172 static struct hostent *_files_ghbyname(const char *name, int af, int *errp); 173 static struct hostent *_files_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 174 static void _files_shent(int stayopen); 175 static void _files_ehent(void); 176 #ifdef YP 177 static struct hostent *_nis_ghbyname(const char *name, int af, int *errp); 178 static struct hostent *_nis_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 179 #endif 180 static struct hostent *_dns_ghbyname(const char *name, int af, int *errp); 181 static struct hostent *_dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 182 static void _dns_shent(int stayopen); 183 static void _dns_ehent(void); 184 #ifdef ICMPNL 185 static struct hostent *_icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 186 #endif /* ICMPNL */ 187 188 /* 189 * Select order host function. 190 */ 191 #define MAXHOSTCONF 4 192 193 #ifndef HOSTCONF 194 # define HOSTCONF "/etc/host.conf" 195 #endif /* !HOSTCONF */ 196 197 struct _hostconf { 198 struct hostent *(*byname)(const char *name, int af, int *errp); 199 struct hostent *(*byaddr)(const void *addr, int addrlen, int af, int *errp); 200 }; 201 202 /* default order */ 203 static struct _hostconf _hostconf[MAXHOSTCONF] = { 204 { _dns_ghbyname, _dns_ghbyaddr }, 205 { _files_ghbyname, _files_ghbyaddr }, 206 #ifdef ICMPNL 207 { NULL, _icmp_ghbyaddr }, 208 #endif /* ICMPNL */ 209 }; 210 211 static int _hostconf_init_done; 212 static void _hostconf_init(void); 213 214 /* 215 * Initialize hostconf structure. 216 */ 217 218 static void 219 _hostconf_init(void) 220 { 221 FILE *fp; 222 int n; 223 char *p, *line; 224 char buf[BUFSIZ]; 225 226 _hostconf_init_done = 1; 227 n = 0; 228 p = HOSTCONF; 229 if ((fp = fopen(p, "r")) == NULL) 230 return; 231 while (n < MAXHOSTCONF && fgets(buf, sizeof(buf), fp)) { 232 line = buf; 233 if ((p = _hgetword(&line)) == NULL) 234 continue; 235 do { 236 if (strcmp(p, "hosts") == 0 237 || strcmp(p, "local") == 0 238 || strcmp(p, "file") == 0 239 || strcmp(p, "files") == 0) { 240 _hostconf[n].byname = _files_ghbyname; 241 _hostconf[n].byaddr = _files_ghbyaddr; 242 n++; 243 } 244 else if (strcmp(p, "dns") == 0 245 || strcmp(p, "bind") == 0) { 246 _hostconf[n].byname = _dns_ghbyname; 247 _hostconf[n].byaddr = _dns_ghbyaddr; 248 n++; 249 } 250 #ifdef YP 251 else if (strcmp(p, "nis") == 0) { 252 _hostconf[n].byname = _nis_ghbyname; 253 _hostconf[n].byaddr = _nis_ghbyaddr; 254 n++; 255 } 256 #endif 257 #ifdef ICMPNL 258 else if (strcmp(p, "icmp") == 0) { 259 _hostconf[n].byname = NULL; 260 _hostconf[n].byaddr = _icmp_ghbyaddr; 261 n++; 262 } 263 #endif /* ICMPNL */ 264 } while ((p = _hgetword(&line)) != NULL); 265 } 266 fclose(fp); 267 if (n < 0) { 268 /* no keyword found. do not change default configuration */ 269 return; 270 } 271 for (; n < MAXHOSTCONF; n++) { 272 _hostconf[n].byname = NULL; 273 _hostconf[n].byaddr = NULL; 274 } 275 } 276 277 /* 278 * Check if kernel supports mapped address. 279 * implementation dependent 280 */ 281 #ifdef __KAME__ 282 #include <sys/sysctl.h> 283 #endif /* __KAME__ */ 284 285 static int 286 _mapped_addr_enabled(void) 287 { 288 /* implementation dependent check */ 289 #if defined(__KAME__) && defined(IPV6CTL_MAPPED_ADDR) 290 int mib[4]; 291 size_t len; 292 int val; 293 294 mib[0] = CTL_NET; 295 mib[1] = PF_INET6; 296 mib[2] = IPPROTO_IPV6; 297 mib[3] = IPV6CTL_MAPPED_ADDR; 298 len = sizeof(val); 299 if (sysctl(mib, 4, &val, &len, 0, 0) == 0 && val != 0) 300 return 1; 301 #endif /* __KAME__ && IPV6CTL_MAPPED_ADDR */ 302 return 0; 303 } 304 305 /* 306 * Functions defined in RFC2553 307 * getipnodebyname, getipnodebyaddr, freehostent 308 */ 309 310 static struct hostent * 311 _ghbyname(const char *name, int af, int flags, int *errp) 312 { 313 struct hostent *hp; 314 int i; 315 316 if (flags & AI_ADDRCONFIG) { 317 int s; 318 319 /* 320 * TODO: 321 * Note that implementation dependent test for address 322 * configuration should be done everytime called 323 * (or apropriate interval), 324 * because addresses will be dynamically assigned or deleted. 325 */ 326 if (af == AF_UNSPEC) { 327 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 328 af = AF_INET; 329 else { 330 _close(s); 331 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) 332 af = AF_INET6; 333 else 334 _close(s); 335 } 336 337 } 338 if (af != AF_UNSPEC) { 339 if ((s = socket(af, SOCK_DGRAM, 0)) < 0) 340 return NULL; 341 _close(s); 342 } 343 } 344 345 for (i = 0; i < MAXHOSTCONF; i++) { 346 if (_hostconf[i].byname 347 && (hp = (*_hostconf[i].byname)(name, af, errp)) != NULL) 348 return hp; 349 } 350 351 return NULL; 352 } 353 354 /* getipnodebyname() internal routine for multiple query(PF_UNSPEC) support. */ 355 struct hostent * 356 _getipnodebyname_multi(const char *name, int af, int flags, int *errp) 357 { 358 struct hostent *hp; 359 union inx_addr addrbuf; 360 361 /* XXX: PF_UNSPEC is only supposed to be passed from getaddrinfo() */ 362 if (af != AF_INET 363 #ifdef INET6 364 && af != AF_INET6 365 #endif 366 && af != PF_UNSPEC 367 ) 368 { 369 *errp = NO_RECOVERY; 370 return NULL; 371 } 372 373 #ifdef INET6 374 /* special case for literal address */ 375 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 376 if (af != AF_INET6) { 377 *errp = HOST_NOT_FOUND; 378 return NULL; 379 } 380 return _hpaddr(af, name, &addrbuf, errp); 381 } 382 #endif 383 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 384 if (af != AF_INET) { 385 if (MAPADDRENABLED(flags)) { 386 MAPADDR(&addrbuf, &addrbuf.in_addr); 387 } else { 388 *errp = HOST_NOT_FOUND; 389 return NULL; 390 } 391 } 392 return _hpaddr(af, name, &addrbuf, errp); 393 } 394 395 if (!_hostconf_init_done) 396 _hostconf_init(); 397 398 *errp = HOST_NOT_FOUND; 399 hp = _ghbyname(name, af, flags, errp); 400 401 #ifdef INET6 402 if (af == AF_INET6 403 && ((flags & AI_ALL) || hp == NULL) 404 && (MAPADDRENABLED(flags))) { 405 struct hostent *hp2 = _ghbyname(name, AF_INET, flags, errp); 406 if (hp == NULL) 407 hp = _hpmapv6(hp2, errp); 408 else { 409 if (hp2 && strcmp(hp->h_name, hp2->h_name) != 0) { 410 freehostent(hp2); 411 hp2 = NULL; 412 } 413 hp = _hpmerge(hp, hp2, errp); 414 } 415 } 416 #endif 417 return _hpsort(hp); 418 } 419 420 struct hostent * 421 getipnodebyname(const char *name, int af, int flags, int *errp) 422 { 423 if (af != AF_INET 424 #ifdef INET6 425 && af != AF_INET6 426 #endif 427 ) 428 { 429 *errp = NO_RECOVERY; 430 return NULL; 431 } 432 return(_getipnodebyname_multi(name, af ,flags, errp)); 433 } 434 435 struct hostent * 436 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 437 { 438 struct hostent *hp; 439 int i; 440 #ifdef INET6 441 struct in6_addr addrbuf; 442 #else 443 struct in_addr addrbuf; 444 #endif 445 446 *errp = HOST_NOT_FOUND; 447 448 switch (af) { 449 case AF_INET: 450 if (len != sizeof(struct in_addr)) { 451 *errp = NO_RECOVERY; 452 return NULL; 453 } 454 if ((long)src & ~(sizeof(struct in_addr) - 1)) { 455 memcpy(&addrbuf, src, len); 456 src = &addrbuf; 457 } 458 if (((struct in_addr *)src)->s_addr == 0) 459 return NULL; 460 break; 461 #ifdef INET6 462 case AF_INET6: 463 if (len != sizeof(struct in6_addr)) { 464 *errp = NO_RECOVERY; 465 return NULL; 466 } 467 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 468 memcpy(&addrbuf, src, len); 469 src = &addrbuf; 470 } 471 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 472 return NULL; 473 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 474 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 475 src = (char *)src + 476 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 477 af = AF_INET; 478 len = sizeof(struct in_addr); 479 } 480 break; 481 #endif 482 default: 483 *errp = NO_RECOVERY; 484 return NULL; 485 } 486 487 if (!_hostconf_init_done) 488 _hostconf_init(); 489 for (i = 0; i < MAXHOSTCONF; i++) { 490 if (_hostconf[i].byaddr 491 && (hp = (*_hostconf[i].byaddr)(src, len, af, errp)) != NULL) 492 return hp; 493 } 494 495 return NULL; 496 } 497 498 void 499 freehostent(struct hostent *ptr) 500 { 501 free(ptr); 502 } 503 504 #if 0 505 506 /* XXX: should be deprecated */ 507 struct hostent * 508 getnodebyname(const char *name, int af, int flags) 509 { 510 return getipnodebyname(name, af, flags, &h_errno); 511 } 512 513 #ifdef __warn_references 514 __warn_references(getnodebyname, 515 "warning: getnodebyname() deprecated, " 516 "should use getaddrinfo() or getipnodebyname()"); 517 #endif 518 519 struct hostent * 520 getnodebyaddr(const void *src, size_t len, int af) 521 { 522 return getipnodebyaddr(src, len, af, &h_errno); 523 } 524 525 #ifdef __warn_references 526 __warn_references(getnodebyaddr, 527 "warning: getnodebyaddr() deprecated, " 528 "should use getnameinfo() or getipnodebyaddr()"); 529 #endif 530 531 #endif 532 533 /* 534 * Private utility functions 535 */ 536 537 /* 538 * _hpcopy: allocate and copy hostent structure 539 */ 540 static struct hostent * 541 _hpcopy(struct hostent *hp, int *errp) 542 { 543 struct hostent *nhp; 544 char *cp, **pp; 545 int size, addrsize; 546 int nalias = 0, naddr = 0; 547 int al_off; 548 int i; 549 550 if (hp == NULL) 551 return hp; 552 553 /* count size to be allocated */ 554 size = sizeof(struct hostent); 555 if (hp->h_name != NULL && *hp->h_name != '\0') 556 size += strlen(hp->h_name) + 1; 557 if ((pp = hp->h_aliases) != NULL) { 558 for (i = 0; *pp != NULL; i++, pp++) { 559 if (**pp != '\0') { 560 size += strlen(*pp) + 1; 561 nalias++; 562 } 563 } 564 } 565 /* adjust alignment */ 566 size = ALIGN(size); 567 al_off = size; 568 size += sizeof(char *) * (nalias + 1); 569 addrsize = ALIGN(hp->h_length); 570 if ((pp = hp->h_addr_list) != NULL) { 571 while (*pp++ != NULL) 572 naddr++; 573 } 574 size += addrsize * naddr; 575 size += sizeof(char *) * (naddr + 1); 576 577 /* copy */ 578 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 579 *errp = TRY_AGAIN; 580 return NULL; 581 } 582 cp = (char *)&nhp[1]; 583 if (hp->h_name != NULL && *hp->h_name != '\0') { 584 nhp->h_name = cp; 585 strcpy(cp, hp->h_name); 586 cp += strlen(cp) + 1; 587 } else 588 nhp->h_name = NULL; 589 nhp->h_aliases = (char **)((char *)nhp + al_off); 590 if ((pp = hp->h_aliases) != NULL) { 591 for (i = 0; *pp != NULL; pp++) { 592 if (**pp != '\0') { 593 nhp->h_aliases[i++] = cp; 594 strcpy(cp, *pp); 595 cp += strlen(cp) + 1; 596 } 597 } 598 } 599 nhp->h_aliases[nalias] = NULL; 600 cp = (char *)&nhp->h_aliases[nalias + 1]; 601 nhp->h_addrtype = hp->h_addrtype; 602 nhp->h_length = hp->h_length; 603 nhp->h_addr_list = (char **)cp; 604 if ((pp = hp->h_addr_list) != NULL) { 605 cp = (char *)&nhp->h_addr_list[naddr + 1]; 606 for (i = 0; *pp != NULL; pp++) { 607 nhp->h_addr_list[i++] = cp; 608 memcpy(cp, *pp, hp->h_length); 609 cp += addrsize; 610 } 611 } 612 nhp->h_addr_list[naddr] = NULL; 613 return nhp; 614 } 615 616 /* 617 * _hpaddr: construct hostent structure with one address 618 */ 619 static struct hostent * 620 _hpaddr(int af, const char *name, void *addr, int *errp) 621 { 622 struct hostent *hp, hpbuf; 623 char *addrs[2]; 624 625 hp = &hpbuf; 626 hp->h_name = (char *)name; 627 hp->h_aliases = NULL; 628 hp->h_addrtype = af; 629 hp->h_length = ADDRLEN(af); 630 hp->h_addr_list = addrs; 631 addrs[0] = (char *)addr; 632 addrs[1] = NULL; 633 return _hpcopy(hp, errp); 634 } 635 636 /* 637 * _hpmerge: merge 2 hostent structure, arguments will be freed 638 */ 639 static struct hostent * 640 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 641 { 642 int i, j; 643 int naddr, nalias; 644 char **pp; 645 struct hostent *hp, hpbuf; 646 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 647 union inx_addr addrbuf[MAXADDRS]; 648 649 if (hp1 == NULL) 650 return hp2; 651 if (hp2 == NULL) 652 return hp1; 653 654 #define HP(i) (i == 1 ? hp1 : hp2) 655 hp = &hpbuf; 656 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 657 hp->h_aliases = aliases; 658 nalias = 0; 659 for (i = 1; i <= 2; i++) { 660 if ((pp = HP(i)->h_aliases) == NULL) 661 continue; 662 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 663 /* check duplicates */ 664 for (j = 0; j < nalias; j++) 665 if (strcasecmp(*pp, aliases[j]) == 0) 666 break; 667 if (j == nalias) 668 aliases[nalias++] = *pp; 669 } 670 } 671 aliases[nalias] = NULL; 672 #ifdef INET6 673 if (hp1->h_length != hp2->h_length) { 674 hp->h_addrtype = AF_INET6; 675 hp->h_length = sizeof(struct in6_addr); 676 } else { 677 #endif 678 hp->h_addrtype = hp1->h_addrtype; 679 hp->h_length = hp1->h_length; 680 #ifdef INET6 681 } 682 #endif 683 hp->h_addr_list = addrs; 684 naddr = 0; 685 for (i = 1; i <= 2; i++) { 686 if ((pp = HP(i)->h_addr_list) == NULL) 687 continue; 688 if (HP(i)->h_length == hp->h_length) { 689 while (naddr < MAXADDRS && *pp != NULL) 690 addrs[naddr++] = *pp++; 691 } else { 692 /* copy IPv4 addr as mapped IPv6 addr */ 693 while (naddr < MAXADDRS && *pp != NULL) { 694 MAPADDR(&addrbuf[naddr], *pp++); 695 addrs[naddr] = (char *)&addrbuf[naddr]; 696 naddr++; 697 } 698 } 699 } 700 addrs[naddr] = NULL; 701 hp = _hpcopy(hp, errp); 702 freehostent(hp1); 703 freehostent(hp2); 704 return hp; 705 } 706 707 /* 708 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 709 */ 710 #ifdef INET6 711 static struct hostent * 712 _hpmapv6(struct hostent *hp, int *errp) 713 { 714 struct hostent *hp6; 715 716 if (hp == NULL) 717 return NULL; 718 if (hp->h_addrtype == AF_INET6) 719 return hp; 720 721 /* make dummy hostent to convert IPv6 address */ 722 if ((hp6 = (struct hostent *)malloc(sizeof(struct hostent))) == NULL) { 723 *errp = TRY_AGAIN; 724 return NULL; 725 } 726 hp6->h_name = NULL; 727 hp6->h_aliases = NULL; 728 hp6->h_addrtype = AF_INET6; 729 hp6->h_length = sizeof(struct in6_addr); 730 hp6->h_addr_list = NULL; 731 return _hpmerge(hp6, hp, errp); 732 } 733 #endif 734 735 /* 736 * _hpsort: sort address by sortlist 737 */ 738 static struct hostent * 739 _hpsort(struct hostent *hp) 740 { 741 int i, j, n; 742 u_char *ap, *sp, *mp, **pp; 743 char t; 744 char order[MAXADDRS]; 745 int nsort = _res.nsort; 746 747 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 748 return hp; 749 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 750 for (j = 0; j < nsort; j++) { 751 #ifdef INET6 752 if (_res_ext.sort_list[j].af != hp->h_addrtype) 753 continue; 754 sp = (u_char *)&_res_ext.sort_list[j].addr; 755 mp = (u_char *)&_res_ext.sort_list[j].mask; 756 #else 757 sp = (u_char *)&_res.sort_list[j].addr; 758 mp = (u_char *)&_res.sort_list[j].mask; 759 #endif 760 for (n = 0; n < hp->h_length; n++) { 761 if ((ap[n] & mp[n]) != sp[n]) 762 break; 763 } 764 if (n == hp->h_length) 765 break; 766 } 767 order[i] = j; 768 } 769 n = i; 770 pp = (u_char **)hp->h_addr_list; 771 for (i = 0; i < n - 1; i++) { 772 for (j = i + 1; j < n; j++) { 773 if (order[i] > order[j]) { 774 ap = pp[i]; 775 pp[i] = pp[j]; 776 pp[j] = ap; 777 t = order[i]; 778 order[i] = order[j]; 779 order[j] = t; 780 } 781 } 782 } 783 return hp; 784 } 785 786 static char * 787 _hgetword(char **pp) 788 { 789 char c, *p, *ret; 790 const char *sp; 791 static const char sep[] = "# \t\n"; 792 793 ret = NULL; 794 for (p = *pp; (c = *p) != '\0'; p++) { 795 for (sp = sep; *sp != '\0'; sp++) { 796 if (c == *sp) 797 break; 798 } 799 if (c == '#') 800 p[1] = '\0'; /* ignore rest of line */ 801 if (ret == NULL) { 802 if (*sp == '\0') 803 ret = p; 804 } else { 805 if (*sp != '\0') { 806 *p++ = '\0'; 807 break; 808 } 809 } 810 } 811 *pp = p; 812 if (ret == NULL || *ret == '\0') 813 return NULL; 814 return ret; 815 } 816 817 /* 818 * FILES (/etc/hosts) 819 */ 820 821 static FILE * 822 _files_open(int *errp) 823 { 824 FILE *fp; 825 fp = fopen(_PATH_HOSTS, "r"); 826 if (fp == NULL) 827 *errp = NO_RECOVERY; 828 return fp; 829 } 830 831 static struct hostent * 832 _files_ghbyname(const char *name, int af, int *errp) 833 { 834 int match, nalias; 835 char *p, *line, *addrstr, *cname; 836 FILE *fp; 837 struct hostent *rethp, *hp, hpbuf; 838 char *aliases[MAXALIASES + 1], *addrs[2]; 839 union inx_addr addrbuf; 840 char buf[BUFSIZ]; 841 int af0 = af; 842 843 if ((fp = _files_open(errp)) == NULL) 844 return NULL; 845 rethp = hp = NULL; 846 847 while (fgets(buf, sizeof(buf), fp)) { 848 line = buf; 849 if ((addrstr = _hgetword(&line)) == NULL 850 || (cname = _hgetword(&line)) == NULL) 851 continue; 852 match = (strcasecmp(cname, name) == 0); 853 nalias = 0; 854 while ((p = _hgetword(&line)) != NULL) { 855 if (!match) 856 match = (strcasecmp(p, name) == 0); 857 if (nalias < MAXALIASES) 858 aliases[nalias++] = p; 859 } 860 if (!match) 861 continue; 862 switch (af0) { 863 case AF_INET: 864 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 865 != 1) { 866 *errp = NO_DATA; /* name found */ 867 continue; 868 } 869 af = af0; 870 break; 871 #ifdef INET6 872 case AF_INET6: 873 if (inet_pton(af, addrstr, &addrbuf) != 1) { 874 *errp = NO_DATA; /* name found */ 875 continue; 876 } 877 af = af0; 878 break; 879 #endif 880 case AF_UNSPEC: 881 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 882 == 1) { 883 af = AF_INET; 884 break; 885 } 886 #ifdef INET6 887 if (inet_pton(AF_INET6, addrstr, &addrbuf) == 1) { 888 af = AF_INET6; 889 break; 890 } 891 #endif 892 *errp = NO_DATA; /* name found */ 893 continue; 894 /* NOTREACHED */ 895 } 896 hp = &hpbuf; 897 hp->h_name = cname; 898 hp->h_aliases = aliases; 899 aliases[nalias] = NULL; 900 hp->h_addrtype = af; 901 hp->h_length = ADDRLEN(af); 902 hp->h_addr_list = addrs; 903 addrs[0] = (char *)&addrbuf; 904 addrs[1] = NULL; 905 hp = _hpcopy(hp, errp); 906 rethp = _hpmerge(rethp, hp, errp); 907 } 908 fclose(fp); 909 return rethp; 910 } 911 912 static struct hostent * 913 _files_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 914 { 915 int nalias; 916 char *p, *line; 917 FILE *fp; 918 struct hostent *hp, hpbuf; 919 char *aliases[MAXALIASES + 1], *addrs[2]; 920 union inx_addr addrbuf; 921 char buf[BUFSIZ]; 922 923 if ((fp = _files_open(errp)) == NULL) 924 return NULL; 925 hp = NULL; 926 while (fgets(buf, sizeof(buf), fp)) { 927 line = buf; 928 if ((p = _hgetword(&line)) == NULL 929 || (af == AF_INET 930 ? inet_aton(p, (struct in_addr *)&addrbuf) 931 : inet_pton(af, p, &addrbuf)) != 1 932 || memcmp(addr, &addrbuf, addrlen) != 0 933 || (p = _hgetword(&line)) == NULL) 934 continue; 935 hp = &hpbuf; 936 hp->h_name = p; 937 hp->h_aliases = aliases; 938 nalias = 0; 939 while ((p = _hgetword(&line)) != NULL) { 940 if (nalias < MAXALIASES) 941 aliases[nalias++] = p; 942 } 943 aliases[nalias] = NULL; 944 hp->h_addrtype = af; 945 hp->h_length = addrlen; 946 hp->h_addr_list = addrs; 947 addrs[0] = (char *)&addrbuf; 948 addrs[1] = NULL; 949 hp = _hpcopy(hp, errp); 950 break; 951 } 952 fclose(fp); 953 return hp; 954 } 955 956 #ifdef YP 957 /* 958 * NIS 959 * 960 * XXX actually a hack, these are INET4 specific. 961 */ 962 static struct hostent * 963 _nis_ghbyname(const char *name, int af, int *errp) 964 { 965 struct hostent *hp = NULL; 966 967 if (af == AF_UNSPEC) 968 af = AF_INET; 969 if (af == AF_INET) { 970 hp = _gethostbynisname(name, af); 971 if (hp != NULL) 972 hp = _hpcopy(hp, errp); 973 } 974 return (hp); 975 976 } 977 978 static struct hostent * 979 _nis_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 980 { 981 struct hostent *hp = NULL; 982 983 if (af == AF_INET) { 984 hp = _gethostbynisaddr(addr, addrlen, af); 985 if (hp != NULL) 986 hp = _hpcopy(hp, errp); 987 } 988 return (hp); 989 } 990 #endif 991 992 struct __res_type_list { 993 SLIST_ENTRY(__res_type_list) rtl_entry; 994 int rtl_type; 995 }; 996 997 #if PACKETSZ > 1024 998 #define MAXPACKET PACKETSZ 999 #else 1000 #define MAXPACKET 1024 1001 #endif 1002 1003 typedef union { 1004 HEADER hdr; 1005 u_char buf[MAXPACKET]; 1006 } querybuf; 1007 1008 static struct hostent *getanswer __P((const querybuf *, int, const char *, 1009 int, struct hostent *, int *)); 1010 1011 /* 1012 * we don't need to take care about sorting, nor IPv4 mapped address here. 1013 */ 1014 static struct hostent * 1015 getanswer(answer, anslen, qname, qtype, template, errp) 1016 const querybuf *answer; 1017 int anslen; 1018 const char *qname; 1019 int qtype; 1020 struct hostent *template; 1021 int *errp; 1022 { 1023 register const HEADER *hp; 1024 register const u_char *cp; 1025 register int n; 1026 const u_char *eom, *erdata; 1027 char *bp, **ap, **hap; 1028 int type, class, buflen, ancount, qdcount; 1029 int haveanswer, had_error; 1030 char tbuf[MAXDNAME]; 1031 const char *tname; 1032 int (*name_ok) __P((const char *)); 1033 static char *h_addr_ptrs[MAXADDRS + 1]; 1034 static char *host_aliases[MAXALIASES]; 1035 static char hostbuf[8*1024]; 1036 1037 #define BOUNDED_INCR(x) \ 1038 do { \ 1039 cp += x; \ 1040 if (cp > eom) { \ 1041 *errp = NO_RECOVERY; \ 1042 return (NULL); \ 1043 } \ 1044 } while (0) 1045 1046 #define BOUNDS_CHECK(ptr, count) \ 1047 do { \ 1048 if ((ptr) + (count) > eom) { \ 1049 *errp = NO_RECOVERY; \ 1050 return (NULL); \ 1051 } \ 1052 } while (0) 1053 1054 #define DNS_ASSERT(x) \ 1055 do { \ 1056 if (!(x)) { \ 1057 cp += n; \ 1058 continue; \ 1059 } \ 1060 } while (0) 1061 1062 #define DNS_FATAL(x) \ 1063 do { \ 1064 if (!(x)) { \ 1065 had_error++; \ 1066 continue; \ 1067 } \ 1068 } while (0) 1069 1070 tname = qname; 1071 template->h_name = NULL; 1072 eom = answer->buf + anslen; 1073 switch (qtype) { 1074 case T_A: 1075 case T_AAAA: 1076 name_ok = res_hnok; 1077 break; 1078 case T_PTR: 1079 name_ok = res_dnok; 1080 break; 1081 default: 1082 return (NULL); /* XXX should be abort(); */ 1083 } 1084 /* 1085 * find first satisfactory answer 1086 */ 1087 hp = &answer->hdr; 1088 ancount = ntohs(hp->ancount); 1089 qdcount = ntohs(hp->qdcount); 1090 bp = hostbuf; 1091 buflen = sizeof hostbuf; 1092 cp = answer->buf; 1093 BOUNDED_INCR(HFIXEDSZ); 1094 if (qdcount != 1) { 1095 *errp = NO_RECOVERY; 1096 return (NULL); 1097 } 1098 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1099 if ((n < 0) || !(*name_ok)(bp)) { 1100 *errp = NO_RECOVERY; 1101 return (NULL); 1102 } 1103 BOUNDED_INCR(n + QFIXEDSZ); 1104 if (qtype == T_A || qtype == T_AAAA) { 1105 /* res_send() has already verified that the query name is the 1106 * same as the one we sent; this just gets the expanded name 1107 * (i.e., with the succeeding search-domain tacked on). 1108 */ 1109 n = strlen(bp) + 1; /* for the \0 */ 1110 if (n >= MAXHOSTNAMELEN) { 1111 *errp = NO_RECOVERY; 1112 return (NULL); 1113 } 1114 template->h_name = bp; 1115 bp += n; 1116 buflen -= n; 1117 /* The qname can be abbreviated, but h_name is now absolute. */ 1118 qname = template->h_name; 1119 } 1120 ap = host_aliases; 1121 *ap = NULL; 1122 template->h_aliases = host_aliases; 1123 hap = h_addr_ptrs; 1124 *hap = NULL; 1125 template->h_addr_list = h_addr_ptrs; 1126 haveanswer = 0; 1127 had_error = 0; 1128 while (ancount-- > 0 && cp < eom && !had_error) { 1129 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1130 DNS_FATAL(n >= 0); 1131 DNS_FATAL((*name_ok)(bp)); 1132 cp += n; /* name */ 1133 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 1134 type = _getshort(cp); 1135 cp += INT16SZ; /* type */ 1136 class = _getshort(cp); 1137 cp += INT16SZ + INT32SZ; /* class, TTL */ 1138 n = _getshort(cp); 1139 cp += INT16SZ; /* len */ 1140 BOUNDS_CHECK(cp, n); 1141 erdata = cp + n; 1142 DNS_ASSERT(class == C_IN); 1143 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 1144 if (ap >= &host_aliases[MAXALIASES-1]) 1145 continue; 1146 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1147 DNS_FATAL(n >= 0); 1148 DNS_FATAL((*name_ok)(tbuf)); 1149 cp += n; 1150 if (cp != erdata) { 1151 *errp = NO_RECOVERY; 1152 return (NULL); 1153 } 1154 /* Store alias. */ 1155 *ap++ = bp; 1156 n = strlen(bp) + 1; /* for the \0 */ 1157 DNS_FATAL(n < MAXHOSTNAMELEN); 1158 bp += n; 1159 buflen -= n; 1160 /* Get canonical name. */ 1161 n = strlen(tbuf) + 1; /* for the \0 */ 1162 DNS_FATAL(n <= buflen); 1163 DNS_FATAL(n < MAXHOSTNAMELEN); 1164 strcpy(bp, tbuf); 1165 template->h_name = bp; 1166 bp += n; 1167 buflen -= n; 1168 continue; 1169 } 1170 if (qtype == T_PTR && type == T_CNAME) { 1171 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1172 if (n < 0 || !res_dnok(tbuf)) { 1173 had_error++; 1174 continue; 1175 } 1176 cp += n; 1177 if (cp != erdata) { 1178 *errp = NO_RECOVERY; 1179 return (NULL); 1180 } 1181 /* Get canonical name. */ 1182 n = strlen(tbuf) + 1; /* for the \0 */ 1183 if (n > buflen || n >= MAXHOSTNAMELEN) { 1184 had_error++; 1185 continue; 1186 } 1187 strcpy(bp, tbuf); 1188 tname = bp; 1189 bp += n; 1190 buflen -= n; 1191 continue; 1192 } 1193 DNS_ASSERT(type == qtype); 1194 switch (type) { 1195 case T_PTR: 1196 DNS_ASSERT(strcasecmp(tname, bp) == 0); 1197 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1198 DNS_FATAL(n >= 0); 1199 DNS_FATAL(res_hnok(bp)); 1200 #if MULTI_PTRS_ARE_ALIASES 1201 cp += n; 1202 if (cp != erdata) { 1203 *errp = NO_RECOVERY; 1204 return (NULL); 1205 } 1206 if (!haveanswer) 1207 template->h_name = bp; 1208 else if (ap < &host_aliases[MAXALIASES-1]) 1209 *ap++ = bp; 1210 else 1211 n = -1; 1212 if (n != -1) { 1213 n = strlen(bp) + 1; /* for the \0 */ 1214 if (n >= MAXHOSTNAMELEN) { 1215 had_error++; 1216 break; 1217 } 1218 bp += n; 1219 buflen -= n; 1220 } 1221 break; 1222 #else 1223 template->h_name = bp; 1224 *errp = NETDB_SUCCESS; 1225 return (template); 1226 #endif 1227 case T_A: 1228 case T_AAAA: 1229 DNS_ASSERT(strcasecmp(template->h_name, bp) == 0); 1230 DNS_ASSERT(n == template->h_length); 1231 if (!haveanswer) { 1232 register int nn; 1233 1234 template->h_name = bp; 1235 nn = strlen(bp) + 1; /* for the \0 */ 1236 bp += nn; 1237 buflen -= nn; 1238 } 1239 bp = (char *)ALIGN(bp); 1240 1241 DNS_FATAL(bp + n < &hostbuf[sizeof hostbuf]); 1242 DNS_ASSERT(hap < &h_addr_ptrs[MAXADDRS-1]); 1243 #ifdef FILTER_V4MAPPED 1244 if (type == T_AAAA) { 1245 struct in6_addr in6; 1246 memcpy(&in6, cp, sizeof(in6)); 1247 DNS_ASSERT(IN6_IS_ADDR_V4MAPPED(&in6) == 0); 1248 } 1249 #endif 1250 bcopy(cp, *hap++ = bp, n); 1251 bp += n; 1252 buflen -= n; 1253 cp += n; 1254 if (cp != erdata) { 1255 *errp = NO_RECOVERY; 1256 return (NULL); 1257 } 1258 break; 1259 default: 1260 abort(); 1261 } 1262 if (!had_error) 1263 haveanswer++; 1264 } 1265 if (haveanswer) { 1266 *ap = NULL; 1267 *hap = NULL; 1268 if (!template->h_name) { 1269 n = strlen(qname) + 1; /* for the \0 */ 1270 if (n > buflen || n >= MAXHOSTNAMELEN) 1271 goto no_recovery; 1272 strcpy(bp, qname); 1273 template->h_name = bp; 1274 bp += n; 1275 buflen -= n; 1276 } 1277 *errp = NETDB_SUCCESS; 1278 return (template); 1279 } 1280 no_recovery: 1281 *errp = NO_RECOVERY; 1282 return (NULL); 1283 1284 #undef BOUNDED_INCR 1285 #undef BOUNDS_CHECK 1286 #undef DNS_ASSERT 1287 #undef DNS_FATAL 1288 } 1289 1290 /* res_search() variant with multiple query support. */ 1291 static struct hostent * 1292 _res_search_multi(name, rtl, errp) 1293 const char *name; /* domain name */ 1294 struct __res_type_list *rtl; /* list of query types */ 1295 int *errp; 1296 { 1297 const char *cp, * const *domain; 1298 struct hostent *hp0 = NULL, *hp; 1299 struct hostent hpbuf; 1300 u_int dots; 1301 int trailing_dot, ret, saved_herrno; 1302 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1303 struct __res_type_list *rtl0 = rtl; 1304 querybuf buf; 1305 1306 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1307 *errp = NETDB_INTERNAL; 1308 return (NULL); 1309 } 1310 dots = 0; 1311 for (cp = name; *cp; cp++) 1312 dots += (*cp == '.'); 1313 trailing_dot = 0; 1314 if (cp > name && *--cp == '.') 1315 trailing_dot++; 1316 1317 /* If there aren't any dots, it could be a user-level alias */ 1318 if (!dots && (cp = hostalias(name)) != NULL) { 1319 for(rtl = rtl0; rtl != NULL; 1320 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1321 ret = res_query(cp, C_IN, rtl->rtl_type, buf.buf, 1322 sizeof(buf.buf)); 1323 if (ret > 0) { 1324 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1325 ? AF_INET6 : AF_INET; 1326 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1327 hp = getanswer(&buf, ret, name, rtl->rtl_type, 1328 &hpbuf, errp); 1329 hp = _hpcopy(&hpbuf, errp); 1330 hp0 = _hpmerge(hp0, hp, errp); 1331 } 1332 } 1333 return (hp0); 1334 } 1335 1336 /* 1337 * If there are dots in the name already, let's just give it a try 1338 * 'as is'. The threshold can be set with the "ndots" option. 1339 */ 1340 saved_herrno = -1; 1341 if (dots >= _res.ndots) { 1342 for(rtl = rtl0; rtl != NULL; 1343 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1344 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1345 buf.buf, sizeof(buf.buf)); 1346 if (ret > 0) { 1347 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1348 ? AF_INET6 : AF_INET; 1349 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1350 hp = getanswer(&buf, ret, name, rtl->rtl_type, 1351 &hpbuf, errp); 1352 hp = _hpcopy(&hpbuf, errp); 1353 hp0 = _hpmerge(hp0, hp, errp); 1354 } 1355 } 1356 if (hp0 != NULL) 1357 return (hp0); 1358 saved_herrno = *errp; 1359 tried_as_is++; 1360 } 1361 1362 /* 1363 * We do at least one level of search if 1364 * - there is no dot and RES_DEFNAME is set, or 1365 * - there is at least one dot, there is no trailing dot, 1366 * and RES_DNSRCH is set. 1367 */ 1368 if ((!dots && (_res.options & RES_DEFNAMES)) || 1369 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1370 int done = 0; 1371 1372 for (domain = (const char * const *)_res.dnsrch; 1373 *domain && !done; 1374 domain++) { 1375 1376 for(rtl = rtl0; rtl != NULL; 1377 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1378 ret = res_querydomain(name, *domain, C_IN, 1379 rtl->rtl_type, 1380 buf.buf, sizeof(buf.buf)); 1381 if (ret > 0) { 1382 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1383 ? AF_INET6 : AF_INET; 1384 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1385 hp = getanswer(&buf, ret, name, 1386 rtl->rtl_type, &hpbuf, errp); 1387 hp = _hpcopy(&hpbuf, errp); 1388 hp0 = _hpmerge(hp0, hp, errp); 1389 } 1390 } 1391 if (hp0 != NULL) 1392 return (hp0); 1393 1394 /* 1395 * If no server present, give up. 1396 * If name isn't found in this domain, 1397 * keep trying higher domains in the search list 1398 * (if that's enabled). 1399 * On a NO_DATA error, keep trying, otherwise 1400 * a wildcard entry of another type could keep us 1401 * from finding this entry higher in the domain. 1402 * If we get some other error (negative answer or 1403 * server failure), then stop searching up, 1404 * but try the input name below in case it's 1405 * fully-qualified. 1406 */ 1407 if (errno == ECONNREFUSED) { 1408 *errp = TRY_AGAIN; 1409 return (NULL); 1410 } 1411 1412 switch (*errp) { 1413 case NO_DATA: 1414 got_nodata++; 1415 /* FALLTHROUGH */ 1416 case HOST_NOT_FOUND: 1417 /* keep trying */ 1418 break; 1419 case TRY_AGAIN: 1420 if (buf.hdr.rcode == SERVFAIL) { 1421 /* try next search element, if any */ 1422 got_servfail++; 1423 break; 1424 } 1425 /* FALLTHROUGH */ 1426 default: 1427 /* anything else implies that we're done */ 1428 done++; 1429 } 1430 1431 /* if we got here for some reason other than DNSRCH, 1432 * we only wanted one iteration of the loop, so stop. 1433 */ 1434 if (!(_res.options & RES_DNSRCH)) 1435 done++; 1436 } 1437 } 1438 1439 /* 1440 * If we have not already tried the name "as is", do that now. 1441 * note that we do this regardless of how many dots were in the 1442 * name or whether it ends with a dot unless NOTLDQUERY is set. 1443 */ 1444 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 1445 for(rtl = rtl0; rtl != NULL; 1446 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1447 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1448 buf.buf, sizeof(buf.buf)); 1449 if (ret > 0) { 1450 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1451 ? AF_INET6 : AF_INET; 1452 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1453 hp = getanswer(&buf, ret, name, rtl->rtl_type, 1454 &hpbuf, errp); 1455 hp = _hpcopy(&hpbuf, errp); 1456 hp0 = _hpmerge(hp0, hp, errp); 1457 } 1458 } 1459 if (hp0 != NULL) 1460 return (hp0); 1461 } 1462 1463 /* if we got here, we didn't satisfy the search. 1464 * if we did an initial full query, return that query's h_errno 1465 * (note that we wouldn't be here if that query had succeeded). 1466 * else if we ever got a nodata, send that back as the reason. 1467 * else send back meaningless h_errno, that being the one from 1468 * the last DNSRCH we did. 1469 */ 1470 if (saved_herrno != -1) 1471 *errp = saved_herrno; 1472 else if (got_nodata) 1473 *errp = NO_DATA; 1474 else if (got_servfail) 1475 *errp = TRY_AGAIN; 1476 return (NULL); 1477 } 1478 1479 static struct hostent * 1480 _dns_ghbyname(const char *name, int af, int *errp) 1481 { 1482 struct __res_type_list *rtl, rtl4; 1483 #ifdef INET6 1484 struct __res_type_list rtl6; 1485 #endif 1486 1487 #ifdef INET6 1488 switch (af) { 1489 case AF_UNSPEC: 1490 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1491 SLIST_NEXT(&rtl6, rtl_entry) = &rtl4; rtl6.rtl_type = T_AAAA; 1492 rtl = &rtl6; 1493 break; 1494 case AF_INET6: 1495 SLIST_NEXT(&rtl6, rtl_entry) = NULL; rtl6.rtl_type = T_AAAA; 1496 rtl = &rtl6; 1497 break; 1498 case AF_INET: 1499 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1500 rtl = &rtl4; 1501 break; 1502 } 1503 #else 1504 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1505 rtl = &rtl4; 1506 #endif 1507 return(_res_search_multi(name, rtl, errp)); 1508 } 1509 1510 static struct hostent * 1511 _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1512 { 1513 int n; 1514 struct hostent *hp; 1515 u_char c, *cp; 1516 char *bp; 1517 struct hostent hbuf; 1518 int na; 1519 #ifdef INET6 1520 static const char hex[] = "0123456789abcdef"; 1521 #endif 1522 querybuf buf; 1523 char qbuf[MAXDNAME+1]; 1524 char *hlist[2]; 1525 1526 #ifdef INET6 1527 /* XXX */ 1528 if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr)) 1529 return NULL; 1530 #endif 1531 1532 if ((_res.options & RES_INIT) == 0) { 1533 if (res_init() < 0) { 1534 *errp = h_errno; 1535 return NULL; 1536 } 1537 } 1538 memset(&hbuf, 0, sizeof(hbuf)); 1539 hbuf.h_name = NULL; 1540 hbuf.h_addrtype = af; 1541 hbuf.h_length = addrlen; 1542 na = 0; 1543 1544 /* XXX assumes that MAXDNAME is big enough */ 1545 n = 0; 1546 bp = qbuf; 1547 cp = (u_char *)addr+addrlen-1; 1548 switch (af) { 1549 #ifdef INET6 1550 case AF_INET6: 1551 for (; n < addrlen; n++, cp--) { 1552 c = *cp; 1553 *bp++ = hex[c & 0xf]; 1554 *bp++ = '.'; 1555 *bp++ = hex[c >> 4]; 1556 *bp++ = '.'; 1557 } 1558 strcpy(bp, "ip6.int"); 1559 break; 1560 #endif 1561 default: 1562 for (; n < addrlen; n++, cp--) { 1563 c = *cp; 1564 if (c >= 100) 1565 *bp++ = '0' + c / 100; 1566 if (c >= 10) 1567 *bp++ = '0' + (c % 100) / 10; 1568 *bp++ = '0' + c % 10; 1569 *bp++ = '.'; 1570 } 1571 strcpy(bp, "in-addr.arpa"); 1572 break; 1573 } 1574 1575 n = res_query(qbuf, C_IN, T_PTR, buf.buf, sizeof buf.buf); 1576 if (n < 0) { 1577 *errp = h_errno; 1578 return NULL; 1579 } 1580 hp = getanswer(&buf, n, qbuf, T_PTR, &hbuf, errp); 1581 hbuf.h_addrtype = af; 1582 hbuf.h_length = addrlen; 1583 hbuf.h_addr_list = hlist; 1584 hlist[0] = (char *)addr; 1585 hlist[1] = NULL; 1586 return _hpcopy(&hbuf, errp); 1587 } 1588 1589 static void 1590 _dns_shent(int stayopen) 1591 { 1592 if ((_res.options & RES_INIT) == 0) { 1593 if (res_init() < 0) 1594 return; 1595 } 1596 if (stayopen) 1597 _res.options |= RES_STAYOPEN | RES_USEVC; 1598 } 1599 1600 static void 1601 _dns_ehent(void) 1602 { 1603 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 1604 res_close(); 1605 } 1606 1607 #ifdef ICMPNL 1608 1609 /* 1610 * experimental: 1611 * draft-ietf-ipngwg-icmp-namelookups-02.txt 1612 * ifindex is assumed to be encoded in addr. 1613 */ 1614 #include <sys/uio.h> 1615 #include <netinet/ip6.h> 1616 #include <netinet/icmp6.h> 1617 1618 struct _icmp_host_cache { 1619 struct _icmp_host_cache *hc_next; 1620 int hc_ifindex; 1621 struct in6_addr hc_addr; 1622 char *hc_name; 1623 }; 1624 1625 static char * 1626 _icmp_fqdn_query(const struct in6_addr *addr, int ifindex) 1627 { 1628 int s; 1629 struct icmp6_filter filter; 1630 struct msghdr msg; 1631 struct cmsghdr *cmsg; 1632 struct in6_pktinfo *pkt; 1633 char cbuf[256]; 1634 char buf[1024]; 1635 int cc; 1636 struct icmp6_fqdn_query *fq; 1637 struct icmp6_fqdn_reply *fr; 1638 struct _icmp_host_cache *hc; 1639 struct sockaddr_in6 sin6; 1640 struct iovec iov; 1641 fd_set s_fds, fds; 1642 struct timeval tout; 1643 int len; 1644 char *name; 1645 static int pid; 1646 static struct _icmp_host_cache *hc_head; 1647 1648 for (hc = hc_head; hc; hc = hc->hc_next) { 1649 if (hc->hc_ifindex == ifindex 1650 && IN6_ARE_ADDR_EQUAL(&hc->hc_addr, addr)) 1651 return hc->hc_name; 1652 } 1653 1654 if (pid == 0) 1655 pid = getpid(); 1656 1657 ICMP6_FILTER_SETBLOCKALL(&filter); 1658 ICMP6_FILTER_SETPASS(ICMP6_FQDN_REPLY, &filter); 1659 1660 FD_ZERO(&s_fds); 1661 tout.tv_sec = 0; 1662 tout.tv_usec = 200000; /*XXX: 200ms*/ 1663 1664 fq = (struct icmp6_fqdn_query *)buf; 1665 fq->icmp6_fqdn_type = ICMP6_FQDN_QUERY; 1666 fq->icmp6_fqdn_code = 0; 1667 fq->icmp6_fqdn_cksum = 0; 1668 fq->icmp6_fqdn_id = (u_short)pid; 1669 fq->icmp6_fqdn_unused = 0; 1670 fq->icmp6_fqdn_cookie[0] = 0; 1671 fq->icmp6_fqdn_cookie[1] = 0; 1672 1673 memset(&sin6, 0, sizeof(sin6)); 1674 sin6.sin6_family = AF_INET6; 1675 sin6.sin6_addr = *addr; 1676 1677 memset(&msg, 0, sizeof(msg)); 1678 msg.msg_name = (caddr_t)&sin6; 1679 msg.msg_namelen = sizeof(sin6); 1680 msg.msg_iov = &iov; 1681 msg.msg_iovlen = 1; 1682 msg.msg_control = NULL; 1683 msg.msg_controllen = 0; 1684 iov.iov_base = (caddr_t)buf; 1685 iov.iov_len = sizeof(struct icmp6_fqdn_query); 1686 1687 if (ifindex) { 1688 msg.msg_control = cbuf; 1689 msg.msg_controllen = sizeof(cbuf); 1690 cmsg = CMSG_FIRSTHDR(&msg); 1691 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 1692 cmsg->cmsg_level = IPPROTO_IPV6; 1693 cmsg->cmsg_type = IPV6_PKTINFO; 1694 pkt = (struct in6_pktinfo *)&cmsg[1]; 1695 memset(&pkt->ipi6_addr, 0, sizeof(struct in6_addr)); 1696 pkt->ipi6_ifindex = ifindex; 1697 cmsg = CMSG_NXTHDR(&msg, cmsg); 1698 msg.msg_controllen = (char *)cmsg - cbuf; 1699 } 1700 1701 if ((s = socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) 1702 return NULL; 1703 (void)setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, 1704 (char *)&filter, sizeof(filter)); 1705 cc = sendmsg(s, &msg, 0); 1706 if (cc < 0) { 1707 _close(s); 1708 return NULL; 1709 } 1710 FD_SET(s, &s_fds); 1711 for (;;) { 1712 fds = s_fds; 1713 if (select(s + 1, &fds, NULL, NULL, &tout) <= 0) { 1714 _close(s); 1715 return NULL; 1716 } 1717 len = sizeof(sin6); 1718 cc = recvfrom(s, buf, sizeof(buf), 0, 1719 (struct sockaddr *)&sin6, &len); 1720 if (cc <= 0) { 1721 _close(s); 1722 return NULL; 1723 } 1724 if (cc < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) 1725 continue; 1726 if (!IN6_ARE_ADDR_EQUAL(addr, &sin6.sin6_addr)) 1727 continue; 1728 fr = (struct icmp6_fqdn_reply *)(buf + sizeof(struct ip6_hdr)); 1729 if (fr->icmp6_fqdn_type == ICMP6_FQDN_REPLY) 1730 break; 1731 } 1732 _close(s); 1733 if (fr->icmp6_fqdn_cookie[1] != 0) { 1734 /* rfc1788 type */ 1735 name = buf + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 4; 1736 len = (buf + cc) - name; 1737 } else { 1738 len = fr->icmp6_fqdn_namelen; 1739 name = fr->icmp6_fqdn_name; 1740 } 1741 if (len <= 0) 1742 return NULL; 1743 name[len] = 0; 1744 1745 if ((hc = (struct _icmp_host_cache *)malloc(sizeof(*hc))) == NULL) 1746 return NULL; 1747 /* XXX: limit number of cached entries */ 1748 hc->hc_ifindex = ifindex; 1749 hc->hc_addr = *addr; 1750 hc->hc_name = strdup(name); 1751 hc->hc_next = hc_head; 1752 hc_head = hc; 1753 return hc->hc_name; 1754 } 1755 1756 static struct hostent * 1757 _icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1758 { 1759 char *hname; 1760 int ifindex; 1761 struct in6_addr addr6; 1762 1763 if (af != AF_INET6) { 1764 /* 1765 * Note: rfc1788 defines Who Are You for IPv4, 1766 * but no one implements it. 1767 */ 1768 return NULL; 1769 } 1770 1771 memcpy(&addr6, addr, addrlen); 1772 ifindex = (addr6.s6_addr[2] << 8) | addr6.s6_addr[3]; 1773 addr6.s6_addr[2] = addr6.s6_addr[3] = 0; 1774 1775 if (!IN6_IS_ADDR_LINKLOCAL(&addr6)) 1776 return NULL; /*XXX*/ 1777 1778 if ((hname = _icmp_fqdn_query(&addr6, ifindex)) == NULL) 1779 return NULL; 1780 return _hpaddr(af, hname, &addr6, errp); 1781 } 1782 #endif /* ICMPNL */ 1783