1 /* $FreeBSD$ */ 2 /* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 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 <stdarg.h> 113 #include <nsswitch.h> 114 #include <unistd.h> 115 116 #ifndef _PATH_HOSTS 117 #define _PATH_HOSTS "/etc/hosts" 118 #endif 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) && _mapped_addr_enabled())) 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 static struct hostent *_hpcopy(struct hostent *hp, int *errp); 163 static struct hostent *_hpaddr(int af, const char *name, void *addr, int *errp); 164 static struct hostent *_hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp); 165 #ifdef INET6 166 static struct hostent *_hpmapv6(struct hostent *hp, int *errp); 167 #endif 168 static struct hostent *_hpsort(struct hostent *hp); 169 static struct hostent *_ghbyname(const char *name, int af, int flags, int *errp); 170 static char *_hgetword(char **pp); 171 static int _mapped_addr_enabled(void); 172 173 static FILE *_files_open(int *errp); 174 static int _files_ghbyname(void *, void *, va_list); 175 static int _files_ghbyaddr(void *, void *, va_list); 176 static void _files_shent(int stayopen); 177 static void _files_ehent(void); 178 #ifdef YP 179 static int _nis_ghbyname(void *, void *, va_list); 180 static int _nis_ghbyaddr(void *, void *, va_list); 181 #endif 182 static int _dns_ghbyname(void *, void *, va_list); 183 static int _dns_ghbyaddr(void *, void *, va_list); 184 static void _dns_shent(int stayopen); 185 static void _dns_ehent(void); 186 #ifdef ICMPNL 187 static int _icmp_ghbyaddr(void *, void *, va_list); 188 #endif /* ICMPNL */ 189 190 /* Host lookup order if nsswitch.conf is broken or nonexistant */ 191 static const ns_src default_src[] = { 192 { NSSRC_FILES, NS_SUCCESS }, 193 { NSSRC_DNS, NS_SUCCESS }, 194 #ifdef ICMPNL 195 #define NSSRC_ICMP "icmp" 196 { NSSRC_ICMP, NS_SUCCESS }, 197 #endif 198 { 0 } 199 }; 200 201 /* 202 * Check if kernel supports mapped address. 203 * implementation dependent 204 */ 205 #ifdef __KAME__ 206 #include <sys/sysctl.h> 207 #endif /* __KAME__ */ 208 209 static int 210 _mapped_addr_enabled(void) 211 { 212 /* implementation dependent check */ 213 #if defined(__KAME__) && defined(IPV6CTL_MAPPED_ADDR) 214 int mib[4]; 215 size_t len; 216 int val; 217 218 mib[0] = CTL_NET; 219 mib[1] = PF_INET6; 220 mib[2] = IPPROTO_IPV6; 221 mib[3] = IPV6CTL_MAPPED_ADDR; 222 len = sizeof(val); 223 if (sysctl(mib, 4, &val, &len, 0, 0) == 0 && val != 0) 224 return 1; 225 #endif /* __KAME__ && IPV6CTL_MAPPED_ADDR */ 226 return 0; 227 } 228 229 /* 230 * Functions defined in RFC2553 231 * getipnodebyname, getipnodebyaddr, freehostent 232 */ 233 234 static struct hostent * 235 _ghbyname(const char *name, int af, int flags, int *errp) 236 { 237 struct hostent *hp; 238 int rval; 239 240 static const ns_dtab dtab[] = { 241 NS_FILES_CB(_files_ghbyname, NULL) 242 { NSSRC_DNS, _dns_ghbyname, NULL }, 243 NS_NIS_CB(_nis_ghbyname, NULL) 244 { 0 } 245 }; 246 247 if (flags & AI_ADDRCONFIG) { 248 int s; 249 250 /* 251 * TODO: 252 * Note that implementation dependent test for address 253 * configuration should be done everytime called 254 * (or apropriate interval), 255 * because addresses will be dynamically assigned or deleted. 256 */ 257 if (af == AF_UNSPEC) { 258 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 259 af = AF_INET; 260 else { 261 _close(s); 262 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) 263 af = AF_INET6; 264 else 265 _close(s); 266 } 267 268 } 269 if (af != AF_UNSPEC) { 270 if ((s = socket(af, SOCK_DGRAM, 0)) < 0) 271 return NULL; 272 _close(s); 273 } 274 } 275 276 rval = nsdispatch(&hp, dtab, NSDB_HOSTS, "ghbyname", default_src, 277 name, af, errp); 278 return (rval == NS_SUCCESS) ? hp : NULL; 279 } 280 281 /* getipnodebyname() internal routine for multiple query(PF_UNSPEC) support. */ 282 struct hostent * 283 _getipnodebyname_multi(const char *name, int af, int flags, int *errp) 284 { 285 struct hostent *hp; 286 union inx_addr addrbuf; 287 288 /* XXX: PF_UNSPEC is only supposed to be passed from getaddrinfo() */ 289 if (af != AF_INET 290 #ifdef INET6 291 && af != AF_INET6 292 #endif 293 && af != PF_UNSPEC 294 ) 295 { 296 *errp = NO_RECOVERY; 297 return NULL; 298 } 299 300 #ifdef INET6 301 /* special case for literal address */ 302 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 303 if (af != AF_INET6) { 304 *errp = HOST_NOT_FOUND; 305 return NULL; 306 } 307 return _hpaddr(af, name, &addrbuf, errp); 308 } 309 #endif 310 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 311 if (af != AF_INET) { 312 if (MAPADDRENABLED(flags)) { 313 MAPADDR(&addrbuf, &addrbuf.in_addr); 314 } else { 315 *errp = HOST_NOT_FOUND; 316 return NULL; 317 } 318 } 319 return _hpaddr(af, name, &addrbuf, errp); 320 } 321 322 *errp = HOST_NOT_FOUND; 323 hp = _ghbyname(name, af, flags, errp); 324 325 #ifdef INET6 326 if (af == AF_INET6 327 && ((flags & AI_ALL) || hp == NULL) 328 && (MAPADDRENABLED(flags))) { 329 struct hostent *hp2 = _ghbyname(name, AF_INET, flags, errp); 330 if (hp == NULL) 331 hp = _hpmapv6(hp2, errp); 332 else { 333 if (hp2 && strcmp(hp->h_name, hp2->h_name) != 0) { 334 freehostent(hp2); 335 hp2 = NULL; 336 } 337 hp = _hpmerge(hp, hp2, errp); 338 } 339 } 340 #endif 341 return _hpsort(hp); 342 } 343 344 struct hostent * 345 getipnodebyname(const char *name, int af, int flags, int *errp) 346 { 347 if (af != AF_INET 348 #ifdef INET6 349 && af != AF_INET6 350 #endif 351 ) 352 { 353 *errp = NO_RECOVERY; 354 return NULL; 355 } 356 return(_getipnodebyname_multi(name, af ,flags, errp)); 357 } 358 359 struct hostent * 360 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 361 { 362 struct hostent *hp; 363 int rval; 364 #ifdef INET6 365 struct in6_addr addrbuf; 366 #else 367 struct in_addr addrbuf; 368 #endif 369 370 static const ns_dtab dtab[] = { 371 NS_FILES_CB(_files_ghbyaddr, NULL) 372 { NSSRC_DNS, _dns_ghbyaddr, NULL }, 373 NS_NIS_CB(_nis_ghbyaddr, NULL) 374 #ifdef ICMPNL 375 { NSSRC_ICMP, _icmp_ghbyaddr, NULL }, 376 #endif 377 { 0 } 378 }; 379 380 *errp = HOST_NOT_FOUND; 381 382 switch (af) { 383 case AF_INET: 384 if (len != sizeof(struct in_addr)) { 385 *errp = NO_RECOVERY; 386 return NULL; 387 } 388 if ((long)src & ~(sizeof(struct in_addr) - 1)) { 389 memcpy(&addrbuf, src, len); 390 src = &addrbuf; 391 } 392 if (((struct in_addr *)src)->s_addr == 0) 393 return NULL; 394 break; 395 #ifdef INET6 396 case AF_INET6: 397 if (len != sizeof(struct in6_addr)) { 398 *errp = NO_RECOVERY; 399 return NULL; 400 } 401 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 402 memcpy(&addrbuf, src, len); 403 src = &addrbuf; 404 } 405 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 406 return NULL; 407 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 408 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 409 src = (char *)src + 410 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 411 af = AF_INET; 412 len = sizeof(struct in_addr); 413 } 414 break; 415 #endif 416 default: 417 *errp = NO_RECOVERY; 418 return NULL; 419 } 420 421 rval = nsdispatch(&hp, dtab, NSDB_HOSTS, "ghbyaddr", default_src, 422 src, len, af, errp); 423 return (rval == NS_SUCCESS) ? hp : NULL; 424 } 425 426 void 427 freehostent(struct hostent *ptr) 428 { 429 free(ptr); 430 } 431 432 #if 0 433 434 /* XXX: should be deprecated */ 435 struct hostent * 436 getnodebyname(const char *name, int af, int flags) 437 { 438 return getipnodebyname(name, af, flags, &h_errno); 439 } 440 441 #ifdef __warn_references 442 __warn_references(getnodebyname, 443 "warning: getnodebyname() deprecated, " 444 "should use getaddrinfo() or getipnodebyname()"); 445 #endif 446 447 struct hostent * 448 getnodebyaddr(const void *src, size_t len, int af) 449 { 450 return getipnodebyaddr(src, len, af, &h_errno); 451 } 452 453 #ifdef __warn_references 454 __warn_references(getnodebyaddr, 455 "warning: getnodebyaddr() deprecated, " 456 "should use getnameinfo() or getipnodebyaddr()"); 457 #endif 458 459 #endif 460 461 /* 462 * Private utility functions 463 */ 464 465 /* 466 * _hpcopy: allocate and copy hostent structure 467 */ 468 static struct hostent * 469 _hpcopy(struct hostent *hp, int *errp) 470 { 471 struct hostent *nhp; 472 char *cp, **pp; 473 int size, addrsize; 474 int nalias = 0, naddr = 0; 475 int al_off; 476 int i; 477 478 if (hp == NULL) 479 return hp; 480 481 /* count size to be allocated */ 482 size = sizeof(struct hostent); 483 if (hp->h_name != NULL) 484 size += strlen(hp->h_name) + 1; 485 if ((pp = hp->h_aliases) != NULL) { 486 for (i = 0; *pp != NULL; i++, pp++) { 487 if (**pp != '\0') { 488 size += strlen(*pp) + 1; 489 nalias++; 490 } 491 } 492 } 493 /* adjust alignment */ 494 size = ALIGN(size); 495 al_off = size; 496 size += sizeof(char *) * (nalias + 1); 497 addrsize = ALIGN(hp->h_length); 498 if ((pp = hp->h_addr_list) != NULL) { 499 while (*pp++ != NULL) 500 naddr++; 501 } 502 size += addrsize * naddr; 503 size += sizeof(char *) * (naddr + 1); 504 505 /* copy */ 506 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 507 *errp = TRY_AGAIN; 508 return NULL; 509 } 510 cp = (char *)&nhp[1]; 511 if (hp->h_name != NULL) { 512 nhp->h_name = cp; 513 strcpy(cp, hp->h_name); 514 cp += strlen(cp) + 1; 515 } else 516 nhp->h_name = NULL; 517 nhp->h_aliases = (char **)((char *)nhp + al_off); 518 if ((pp = hp->h_aliases) != NULL) { 519 for (i = 0; *pp != NULL; pp++) { 520 if (**pp != '\0') { 521 nhp->h_aliases[i++] = cp; 522 strcpy(cp, *pp); 523 cp += strlen(cp) + 1; 524 } 525 } 526 } 527 nhp->h_aliases[nalias] = NULL; 528 cp = (char *)&nhp->h_aliases[nalias + 1]; 529 nhp->h_addrtype = hp->h_addrtype; 530 nhp->h_length = hp->h_length; 531 nhp->h_addr_list = (char **)cp; 532 if ((pp = hp->h_addr_list) != NULL) { 533 cp = (char *)&nhp->h_addr_list[naddr + 1]; 534 for (i = 0; *pp != NULL; pp++) { 535 nhp->h_addr_list[i++] = cp; 536 memcpy(cp, *pp, hp->h_length); 537 cp += addrsize; 538 } 539 } 540 nhp->h_addr_list[naddr] = NULL; 541 return nhp; 542 } 543 544 /* 545 * _hpaddr: construct hostent structure with one address 546 */ 547 static struct hostent * 548 _hpaddr(int af, const char *name, void *addr, int *errp) 549 { 550 struct hostent *hp, hpbuf; 551 char *addrs[2]; 552 553 hp = &hpbuf; 554 hp->h_name = (char *)name; 555 hp->h_aliases = NULL; 556 hp->h_addrtype = af; 557 hp->h_length = ADDRLEN(af); 558 hp->h_addr_list = addrs; 559 addrs[0] = (char *)addr; 560 addrs[1] = NULL; 561 return _hpcopy(hp, errp); 562 } 563 564 /* 565 * _hpmerge: merge 2 hostent structure, arguments will be freed 566 */ 567 static struct hostent * 568 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 569 { 570 int i, j; 571 int naddr, nalias; 572 char **pp; 573 struct hostent *hp, hpbuf; 574 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 575 union inx_addr addrbuf[MAXADDRS]; 576 577 if (hp1 == NULL) 578 return hp2; 579 if (hp2 == NULL) 580 return hp1; 581 582 #define HP(i) (i == 1 ? hp1 : hp2) 583 hp = &hpbuf; 584 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 585 hp->h_aliases = aliases; 586 nalias = 0; 587 for (i = 1; i <= 2; i++) { 588 if ((pp = HP(i)->h_aliases) == NULL) 589 continue; 590 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 591 /* check duplicates */ 592 for (j = 0; j < nalias; j++) 593 if (strcasecmp(*pp, aliases[j]) == 0) 594 break; 595 if (j == nalias) 596 aliases[nalias++] = *pp; 597 } 598 } 599 aliases[nalias] = NULL; 600 #ifdef INET6 601 if (hp1->h_length != hp2->h_length) { 602 hp->h_addrtype = AF_INET6; 603 hp->h_length = sizeof(struct in6_addr); 604 } else { 605 #endif 606 hp->h_addrtype = hp1->h_addrtype; 607 hp->h_length = hp1->h_length; 608 #ifdef INET6 609 } 610 #endif 611 hp->h_addr_list = addrs; 612 naddr = 0; 613 for (i = 1; i <= 2; i++) { 614 if ((pp = HP(i)->h_addr_list) == NULL) 615 continue; 616 if (HP(i)->h_length == hp->h_length) { 617 while (naddr < MAXADDRS && *pp != NULL) 618 addrs[naddr++] = *pp++; 619 } else { 620 /* copy IPv4 addr as mapped IPv6 addr */ 621 while (naddr < MAXADDRS && *pp != NULL) { 622 MAPADDR(&addrbuf[naddr], *pp++); 623 addrs[naddr] = (char *)&addrbuf[naddr]; 624 naddr++; 625 } 626 } 627 } 628 addrs[naddr] = NULL; 629 hp = _hpcopy(hp, errp); 630 freehostent(hp1); 631 freehostent(hp2); 632 return hp; 633 } 634 635 /* 636 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 637 */ 638 #ifdef INET6 639 static struct hostent * 640 _hpmapv6(struct hostent *hp, int *errp) 641 { 642 struct hostent *hp6; 643 644 if (hp == NULL) 645 return NULL; 646 if (hp->h_addrtype == AF_INET6) 647 return hp; 648 649 /* make dummy hostent to convert IPv6 address */ 650 if ((hp6 = (struct hostent *)malloc(sizeof(struct hostent))) == NULL) { 651 *errp = TRY_AGAIN; 652 return NULL; 653 } 654 hp6->h_name = NULL; 655 hp6->h_aliases = NULL; 656 hp6->h_addrtype = AF_INET6; 657 hp6->h_length = sizeof(struct in6_addr); 658 hp6->h_addr_list = NULL; 659 return _hpmerge(hp6, hp, errp); 660 } 661 #endif 662 663 /* 664 * _hpsort: sort address by sortlist 665 */ 666 static struct hostent * 667 _hpsort(struct hostent *hp) 668 { 669 int i, j, n; 670 u_char *ap, *sp, *mp, **pp; 671 char t; 672 char order[MAXADDRS]; 673 int nsort = _res.nsort; 674 675 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 676 return hp; 677 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 678 for (j = 0; j < nsort; j++) { 679 #ifdef INET6 680 if (_res_ext.sort_list[j].af != hp->h_addrtype) 681 continue; 682 sp = (u_char *)&_res_ext.sort_list[j].addr; 683 mp = (u_char *)&_res_ext.sort_list[j].mask; 684 #else 685 sp = (u_char *)&_res.sort_list[j].addr; 686 mp = (u_char *)&_res.sort_list[j].mask; 687 #endif 688 for (n = 0; n < hp->h_length; n++) { 689 if ((ap[n] & mp[n]) != sp[n]) 690 break; 691 } 692 if (n == hp->h_length) 693 break; 694 } 695 order[i] = j; 696 } 697 n = i; 698 pp = (u_char **)hp->h_addr_list; 699 for (i = 0; i < n - 1; i++) { 700 for (j = i + 1; j < n; j++) { 701 if (order[i] > order[j]) { 702 ap = pp[i]; 703 pp[i] = pp[j]; 704 pp[j] = ap; 705 t = order[i]; 706 order[i] = order[j]; 707 order[j] = t; 708 } 709 } 710 } 711 return hp; 712 } 713 714 static char * 715 _hgetword(char **pp) 716 { 717 char c, *p, *ret; 718 const char *sp; 719 static const char sep[] = "# \t\n"; 720 721 ret = NULL; 722 for (p = *pp; (c = *p) != '\0'; p++) { 723 for (sp = sep; *sp != '\0'; sp++) { 724 if (c == *sp) 725 break; 726 } 727 if (c == '#') 728 p[1] = '\0'; /* ignore rest of line */ 729 if (ret == NULL) { 730 if (*sp == '\0') 731 ret = p; 732 } else { 733 if (*sp != '\0') { 734 *p++ = '\0'; 735 break; 736 } 737 } 738 } 739 *pp = p; 740 if (ret == NULL || *ret == '\0') 741 return NULL; 742 return ret; 743 } 744 745 /* 746 * FILES (/etc/hosts) 747 */ 748 749 static FILE * 750 _files_open(int *errp) 751 { 752 FILE *fp; 753 fp = fopen(_PATH_HOSTS, "r"); 754 if (fp == NULL) 755 *errp = NO_RECOVERY; 756 return fp; 757 } 758 759 static int 760 _files_ghbyname(void *rval, void *cb_data, va_list ap) 761 { 762 const char *name; 763 int af; 764 int *errp; 765 int match, nalias; 766 char *p, *line, *addrstr, *cname; 767 FILE *fp; 768 struct hostent *rethp, *hp, hpbuf; 769 char *aliases[MAXALIASES + 1], *addrs[2]; 770 union inx_addr addrbuf; 771 char buf[BUFSIZ]; 772 int af0; 773 774 name = va_arg(ap, const char *); 775 af = va_arg(ap, int); 776 errp = va_arg(ap, int *); 777 778 *(struct hostent **)rval = NULL; 779 780 if ((fp = _files_open(errp)) == NULL) 781 return NS_UNAVAIL; 782 rethp = hp = NULL; 783 784 af0 = af; 785 while (fgets(buf, sizeof(buf), fp)) { 786 line = buf; 787 if ((addrstr = _hgetword(&line)) == NULL 788 || (cname = _hgetword(&line)) == NULL) 789 continue; 790 match = (strcasecmp(cname, name) == 0); 791 nalias = 0; 792 while ((p = _hgetword(&line)) != NULL) { 793 if (!match) 794 match = (strcasecmp(p, name) == 0); 795 if (nalias < MAXALIASES) 796 aliases[nalias++] = p; 797 } 798 if (!match) 799 continue; 800 switch (af0) { 801 case AF_INET: 802 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 803 != 1) { 804 *errp = NO_DATA; /* name found */ 805 continue; 806 } 807 af = af0; 808 break; 809 #ifdef INET6 810 case AF_INET6: 811 if (inet_pton(af, addrstr, &addrbuf) != 1) { 812 *errp = NO_DATA; /* name found */ 813 continue; 814 } 815 af = af0; 816 break; 817 #endif 818 case AF_UNSPEC: 819 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 820 == 1) { 821 af = AF_INET; 822 break; 823 } 824 #ifdef INET6 825 if (inet_pton(AF_INET6, addrstr, &addrbuf) == 1) { 826 af = AF_INET6; 827 break; 828 } 829 #endif 830 *errp = NO_DATA; /* name found */ 831 continue; 832 /* NOTREACHED */ 833 } 834 hp = &hpbuf; 835 hp->h_name = cname; 836 hp->h_aliases = aliases; 837 aliases[nalias] = NULL; 838 hp->h_addrtype = af; 839 hp->h_length = ADDRLEN(af); 840 hp->h_addr_list = addrs; 841 addrs[0] = (char *)&addrbuf; 842 addrs[1] = NULL; 843 hp = _hpcopy(hp, errp); 844 rethp = _hpmerge(rethp, hp, errp); 845 } 846 fclose(fp); 847 *(struct hostent **)rval = rethp; 848 return (rethp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 849 } 850 851 static int 852 _files_ghbyaddr(void *rval, void *cb_data, va_list ap) 853 { 854 const void *addr; 855 int addrlen; 856 int af; 857 int *errp; 858 int nalias; 859 char *p, *line; 860 FILE *fp; 861 struct hostent *hp, hpbuf; 862 char *aliases[MAXALIASES + 1], *addrs[2]; 863 union inx_addr addrbuf; 864 char buf[BUFSIZ]; 865 866 addr = va_arg(ap, const void *); 867 addrlen = va_arg(ap, int); 868 af = va_arg(ap, int); 869 errp = va_arg(ap, int *); 870 871 *(struct hostent**)rval = NULL; 872 873 if ((fp = _files_open(errp)) == NULL) 874 return NS_UNAVAIL; 875 hp = NULL; 876 while (fgets(buf, sizeof(buf), fp)) { 877 line = buf; 878 if ((p = _hgetword(&line)) == NULL 879 || (af == AF_INET 880 ? inet_aton(p, (struct in_addr *)&addrbuf) 881 : inet_pton(af, p, &addrbuf)) != 1 882 || memcmp(addr, &addrbuf, addrlen) != 0 883 || (p = _hgetword(&line)) == NULL) 884 continue; 885 hp = &hpbuf; 886 hp->h_name = p; 887 hp->h_aliases = aliases; 888 nalias = 0; 889 while ((p = _hgetword(&line)) != NULL) { 890 if (nalias < MAXALIASES) 891 aliases[nalias++] = p; 892 } 893 aliases[nalias] = NULL; 894 hp->h_addrtype = af; 895 hp->h_length = addrlen; 896 hp->h_addr_list = addrs; 897 addrs[0] = (char *)&addrbuf; 898 addrs[1] = NULL; 899 hp = _hpcopy(hp, errp); 900 break; 901 } 902 fclose(fp); 903 *(struct hostent **)rval = hp; 904 return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 905 } 906 907 #ifdef YP 908 /* 909 * NIS 910 * 911 * XXX actually a hack, these are INET4 specific. 912 */ 913 static int 914 _nis_ghbyname(void *rval, void *cb_data, va_list ap) 915 { 916 const char *name; 917 int af; 918 int *errp; 919 struct hostent *hp = NULL; 920 921 name = va_arg(ap, const char *); 922 af = va_arg(ap, int); 923 errp = va_arg(ap, int *); 924 925 if (af == AF_UNSPEC) 926 af = AF_INET; 927 if (af == AF_INET) { 928 hp = _gethostbynisname(name, af); 929 if (hp != NULL) 930 hp = _hpcopy(hp, errp); 931 } 932 933 *(struct hostent **)rval = hp; 934 return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 935 936 } 937 938 static int 939 _nis_ghbyaddr(void *rval, void *cb_data, va_list ap) 940 { 941 const void *addr; 942 int addrlen; 943 int af; 944 int *errp; 945 struct hostent *hp = NULL; 946 947 addr = va_arg(ap, const void *); 948 addrlen = va_arg(ap, int); 949 af = va_arg(ap, int); 950 951 if (af == AF_INET) { 952 hp = _gethostbynisaddr(addr, addrlen, af); 953 if (hp != NULL) 954 hp = _hpcopy(hp, errp); 955 } 956 *(struct hostent **)rval = hp; 957 return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND; 958 } 959 #endif 960 961 struct __res_type_list { 962 SLIST_ENTRY(__res_type_list) rtl_entry; 963 int rtl_type; 964 }; 965 966 #if PACKETSZ > 1024 967 #define MAXPACKET PACKETSZ 968 #else 969 #define MAXPACKET 1024 970 #endif 971 972 typedef union { 973 HEADER hdr; 974 u_char buf[MAXPACKET]; 975 } querybuf; 976 977 static struct hostent *getanswer __P((const querybuf *, int, const char *, 978 int, struct hostent *, int *)); 979 980 /* 981 * we don't need to take care about sorting, nor IPv4 mapped address here. 982 */ 983 static struct hostent * 984 getanswer(answer, anslen, qname, qtype, template, errp) 985 const querybuf *answer; 986 int anslen; 987 const char *qname; 988 int qtype; 989 struct hostent *template; 990 int *errp; 991 { 992 register const HEADER *hp; 993 register const u_char *cp; 994 register int n; 995 const u_char *eom, *erdata; 996 char *bp, **ap, **hap; 997 int type, class, buflen, ancount, qdcount; 998 int haveanswer, had_error; 999 char tbuf[MAXDNAME]; 1000 const char *tname; 1001 int (*name_ok) __P((const char *)); 1002 static char *h_addr_ptrs[MAXADDRS + 1]; 1003 static char *host_aliases[MAXALIASES]; 1004 static char hostbuf[8*1024]; 1005 1006 #define BOUNDED_INCR(x) \ 1007 do { \ 1008 cp += x; \ 1009 if (cp > eom) { \ 1010 *errp = NO_RECOVERY; \ 1011 return (NULL); \ 1012 } \ 1013 } while (0) 1014 1015 #define BOUNDS_CHECK(ptr, count) \ 1016 do { \ 1017 if ((ptr) + (count) > eom) { \ 1018 *errp = NO_RECOVERY; \ 1019 return (NULL); \ 1020 } \ 1021 } while (0) 1022 1023 /* XXX do {} while (0) cannot be put here */ 1024 #define DNS_ASSERT(x) \ 1025 { \ 1026 if (!(x)) { \ 1027 cp += n; \ 1028 continue; \ 1029 } \ 1030 } 1031 1032 /* XXX do {} while (0) cannot be put here */ 1033 #define DNS_FATAL(x) \ 1034 { \ 1035 if (!(x)) { \ 1036 had_error++; \ 1037 continue; \ 1038 } \ 1039 } 1040 1041 tname = qname; 1042 template->h_name = NULL; 1043 eom = answer->buf + anslen; 1044 switch (qtype) { 1045 case T_A: 1046 case T_AAAA: 1047 name_ok = res_hnok; 1048 break; 1049 case T_PTR: 1050 name_ok = res_dnok; 1051 break; 1052 default: 1053 return (NULL); /* XXX should be abort(); */ 1054 } 1055 /* 1056 * find first satisfactory answer 1057 */ 1058 hp = &answer->hdr; 1059 ancount = ntohs(hp->ancount); 1060 qdcount = ntohs(hp->qdcount); 1061 bp = hostbuf; 1062 buflen = sizeof hostbuf; 1063 cp = answer->buf; 1064 BOUNDED_INCR(HFIXEDSZ); 1065 if (qdcount != 1) { 1066 *errp = NO_RECOVERY; 1067 return (NULL); 1068 } 1069 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1070 if ((n < 0) || !(*name_ok)(bp)) { 1071 *errp = NO_RECOVERY; 1072 return (NULL); 1073 } 1074 BOUNDED_INCR(n + QFIXEDSZ); 1075 if (qtype == T_A || qtype == T_AAAA) { 1076 /* res_send() has already verified that the query name is the 1077 * same as the one we sent; this just gets the expanded name 1078 * (i.e., with the succeeding search-domain tacked on). 1079 */ 1080 n = strlen(bp) + 1; /* for the \0 */ 1081 if (n >= MAXHOSTNAMELEN) { 1082 *errp = NO_RECOVERY; 1083 return (NULL); 1084 } 1085 template->h_name = bp; 1086 bp += n; 1087 buflen -= n; 1088 /* The qname can be abbreviated, but h_name is now absolute. */ 1089 qname = template->h_name; 1090 } 1091 ap = host_aliases; 1092 *ap = NULL; 1093 template->h_aliases = host_aliases; 1094 hap = h_addr_ptrs; 1095 *hap = NULL; 1096 template->h_addr_list = h_addr_ptrs; 1097 haveanswer = 0; 1098 had_error = 0; 1099 while (ancount-- > 0 && cp < eom && !had_error) { 1100 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1101 DNS_FATAL(n >= 0); 1102 DNS_FATAL((*name_ok)(bp)); 1103 cp += n; /* name */ 1104 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 1105 type = _getshort(cp); 1106 cp += INT16SZ; /* type */ 1107 class = _getshort(cp); 1108 cp += INT16SZ + INT32SZ; /* class, TTL */ 1109 n = _getshort(cp); 1110 cp += INT16SZ; /* len */ 1111 BOUNDS_CHECK(cp, n); 1112 erdata = cp + n; 1113 DNS_ASSERT(class == C_IN); 1114 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 1115 if (ap >= &host_aliases[MAXALIASES-1]) 1116 continue; 1117 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1118 DNS_FATAL(n >= 0); 1119 DNS_FATAL((*name_ok)(tbuf)); 1120 cp += n; 1121 if (cp != erdata) { 1122 *errp = NO_RECOVERY; 1123 return (NULL); 1124 } 1125 /* Store alias. */ 1126 *ap++ = bp; 1127 n = strlen(bp) + 1; /* for the \0 */ 1128 DNS_FATAL(n < MAXHOSTNAMELEN); 1129 bp += n; 1130 buflen -= n; 1131 /* Get canonical name. */ 1132 n = strlen(tbuf) + 1; /* for the \0 */ 1133 DNS_FATAL(n <= buflen); 1134 DNS_FATAL(n < MAXHOSTNAMELEN); 1135 strcpy(bp, tbuf); 1136 template->h_name = bp; 1137 bp += n; 1138 buflen -= n; 1139 continue; 1140 } 1141 if (qtype == T_PTR && type == T_CNAME) { 1142 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1143 if (n < 0 || !res_dnok(tbuf)) { 1144 had_error++; 1145 continue; 1146 } 1147 cp += n; 1148 if (cp != erdata) { 1149 *errp = NO_RECOVERY; 1150 return (NULL); 1151 } 1152 /* Get canonical name. */ 1153 n = strlen(tbuf) + 1; /* for the \0 */ 1154 if (n > buflen || n >= MAXHOSTNAMELEN) { 1155 had_error++; 1156 continue; 1157 } 1158 strcpy(bp, tbuf); 1159 tname = bp; 1160 bp += n; 1161 buflen -= n; 1162 continue; 1163 } 1164 DNS_ASSERT(type == qtype); 1165 switch (type) { 1166 case T_PTR: 1167 DNS_ASSERT(strcasecmp(tname, bp) == 0); 1168 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1169 DNS_FATAL(n >= 0); 1170 DNS_FATAL(res_hnok(bp)); 1171 #if MULTI_PTRS_ARE_ALIASES 1172 cp += n; 1173 if (cp != erdata) { 1174 *errp = NO_RECOVERY; 1175 return (NULL); 1176 } 1177 if (!haveanswer) 1178 template->h_name = bp; 1179 else if (ap < &host_aliases[MAXALIASES-1]) 1180 *ap++ = bp; 1181 else 1182 n = -1; 1183 if (n != -1) { 1184 n = strlen(bp) + 1; /* for the \0 */ 1185 if (n >= MAXHOSTNAMELEN) { 1186 had_error++; 1187 break; 1188 } 1189 bp += n; 1190 buflen -= n; 1191 } 1192 break; 1193 #else 1194 template->h_name = bp; 1195 *errp = NETDB_SUCCESS; 1196 return (template); 1197 #endif 1198 case T_A: 1199 case T_AAAA: 1200 DNS_ASSERT(strcasecmp(template->h_name, bp) == 0); 1201 DNS_ASSERT(n == template->h_length); 1202 if (!haveanswer) { 1203 register int nn; 1204 1205 template->h_name = bp; 1206 nn = strlen(bp) + 1; /* for the \0 */ 1207 bp += nn; 1208 buflen -= nn; 1209 } 1210 bp = (char *)ALIGN(bp); 1211 1212 DNS_FATAL(bp + n < &hostbuf[sizeof hostbuf]); 1213 DNS_ASSERT(hap < &h_addr_ptrs[MAXADDRS-1]); 1214 #ifdef FILTER_V4MAPPED 1215 if (type == T_AAAA) { 1216 struct in6_addr in6; 1217 memcpy(&in6, cp, sizeof(in6)); 1218 DNS_ASSERT(IN6_IS_ADDR_V4MAPPED(&in6) == 0); 1219 } 1220 #endif 1221 bcopy(cp, *hap++ = bp, n); 1222 bp += n; 1223 buflen -= n; 1224 cp += n; 1225 if (cp != erdata) { 1226 *errp = NO_RECOVERY; 1227 return (NULL); 1228 } 1229 break; 1230 default: 1231 abort(); 1232 } 1233 if (!had_error) 1234 haveanswer++; 1235 } 1236 if (haveanswer) { 1237 *ap = NULL; 1238 *hap = NULL; 1239 if (!template->h_name) { 1240 n = strlen(qname) + 1; /* for the \0 */ 1241 if (n > buflen || n >= MAXHOSTNAMELEN) 1242 goto no_recovery; 1243 strcpy(bp, qname); 1244 template->h_name = bp; 1245 bp += n; 1246 buflen -= n; 1247 } 1248 *errp = NETDB_SUCCESS; 1249 return (template); 1250 } 1251 no_recovery: 1252 *errp = NO_RECOVERY; 1253 return (NULL); 1254 1255 #undef BOUNDED_INCR 1256 #undef BOUNDS_CHECK 1257 #undef DNS_ASSERT 1258 #undef DNS_FATAL 1259 } 1260 1261 /* res_search() variant with multiple query support. */ 1262 static struct hostent * 1263 _res_search_multi(name, rtl, errp) 1264 const char *name; /* domain name */ 1265 struct __res_type_list *rtl; /* list of query types */ 1266 int *errp; 1267 { 1268 const char *cp, * const *domain; 1269 struct hostent *hp0 = NULL, *hp; 1270 struct hostent hpbuf; 1271 u_int dots; 1272 int trailing_dot, ret, saved_herrno; 1273 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1274 struct __res_type_list *rtl0 = rtl; 1275 querybuf buf; 1276 1277 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1278 *errp = NETDB_INTERNAL; 1279 return (NULL); 1280 } 1281 dots = 0; 1282 for (cp = name; *cp; cp++) 1283 dots += (*cp == '.'); 1284 trailing_dot = 0; 1285 if (cp > name && *--cp == '.') 1286 trailing_dot++; 1287 1288 /* If there aren't any dots, it could be a user-level alias */ 1289 if (!dots && (cp = hostalias(name)) != NULL) { 1290 for(rtl = rtl0; rtl != NULL; 1291 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1292 ret = res_query(cp, C_IN, rtl->rtl_type, buf.buf, 1293 sizeof(buf.buf)); 1294 if (ret > 0) { 1295 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1296 ? AF_INET6 : AF_INET; 1297 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1298 hp = getanswer(&buf, ret, name, rtl->rtl_type, 1299 &hpbuf, errp); 1300 if (!hp) 1301 continue; 1302 hp = _hpcopy(&hpbuf, errp); 1303 hp0 = _hpmerge(hp0, hp, errp); 1304 } 1305 } 1306 return (hp0); 1307 } 1308 1309 /* 1310 * If there are dots in the name already, let's just give it a try 1311 * 'as is'. The threshold can be set with the "ndots" option. 1312 */ 1313 saved_herrno = -1; 1314 if (dots >= _res.ndots) { 1315 for(rtl = rtl0; rtl != NULL; 1316 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1317 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1318 buf.buf, sizeof(buf.buf)); 1319 if (ret > 0) { 1320 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1321 ? AF_INET6 : AF_INET; 1322 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1323 hp = getanswer(&buf, ret, name, rtl->rtl_type, 1324 &hpbuf, errp); 1325 if (!hp) 1326 continue; 1327 hp = _hpcopy(&hpbuf, errp); 1328 hp0 = _hpmerge(hp0, hp, errp); 1329 } 1330 } 1331 if (hp0 != NULL) 1332 return (hp0); 1333 saved_herrno = *errp; 1334 tried_as_is++; 1335 } 1336 1337 /* 1338 * We do at least one level of search if 1339 * - there is no dot and RES_DEFNAME is set, or 1340 * - there is at least one dot, there is no trailing dot, 1341 * and RES_DNSRCH is set. 1342 */ 1343 if ((!dots && (_res.options & RES_DEFNAMES)) || 1344 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1345 int done = 0; 1346 1347 for (domain = (const char * const *)_res.dnsrch; 1348 *domain && !done; 1349 domain++) { 1350 1351 for(rtl = rtl0; rtl != NULL; 1352 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1353 ret = res_querydomain(name, *domain, C_IN, 1354 rtl->rtl_type, 1355 buf.buf, sizeof(buf.buf)); 1356 if (ret > 0) { 1357 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1358 ? AF_INET6 : AF_INET; 1359 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1360 hp = getanswer(&buf, ret, name, 1361 rtl->rtl_type, &hpbuf, errp); 1362 if (!hp) 1363 continue; 1364 hp = _hpcopy(&hpbuf, errp); 1365 hp0 = _hpmerge(hp0, hp, errp); 1366 } 1367 } 1368 if (hp0 != NULL) 1369 return (hp0); 1370 1371 /* 1372 * If no server present, give up. 1373 * If name isn't found in this domain, 1374 * keep trying higher domains in the search list 1375 * (if that's enabled). 1376 * On a NO_DATA error, keep trying, otherwise 1377 * a wildcard entry of another type could keep us 1378 * from finding this entry higher in the domain. 1379 * If we get some other error (negative answer or 1380 * server failure), then stop searching up, 1381 * but try the input name below in case it's 1382 * fully-qualified. 1383 */ 1384 if (errno == ECONNREFUSED) { 1385 *errp = TRY_AGAIN; 1386 return (NULL); 1387 } 1388 1389 switch (*errp) { 1390 case NO_DATA: 1391 got_nodata++; 1392 /* FALLTHROUGH */ 1393 case HOST_NOT_FOUND: 1394 /* keep trying */ 1395 break; 1396 case TRY_AGAIN: 1397 if (buf.hdr.rcode == SERVFAIL) { 1398 /* try next search element, if any */ 1399 got_servfail++; 1400 break; 1401 } 1402 /* FALLTHROUGH */ 1403 default: 1404 /* anything else implies that we're done */ 1405 done++; 1406 } 1407 1408 /* if we got here for some reason other than DNSRCH, 1409 * we only wanted one iteration of the loop, so stop. 1410 */ 1411 if (!(_res.options & RES_DNSRCH)) 1412 done++; 1413 } 1414 } 1415 1416 /* 1417 * If we have not already tried the name "as is", do that now. 1418 * note that we do this regardless of how many dots were in the 1419 * name or whether it ends with a dot unless NOTLDQUERY is set. 1420 */ 1421 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 1422 for(rtl = rtl0; rtl != NULL; 1423 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1424 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1425 buf.buf, sizeof(buf.buf)); 1426 if (ret > 0) { 1427 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1428 ? AF_INET6 : AF_INET; 1429 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1430 hp = getanswer(&buf, ret, name, rtl->rtl_type, 1431 &hpbuf, errp); 1432 if (!hp) 1433 continue; 1434 hp = _hpcopy(&hpbuf, errp); 1435 hp0 = _hpmerge(hp0, hp, errp); 1436 } 1437 } 1438 if (hp0 != NULL) 1439 return (hp0); 1440 } 1441 1442 /* if we got here, we didn't satisfy the search. 1443 * if we did an initial full query, return that query's h_errno 1444 * (note that we wouldn't be here if that query had succeeded). 1445 * else if we ever got a nodata, send that back as the reason. 1446 * else send back meaningless h_errno, that being the one from 1447 * the last DNSRCH we did. 1448 */ 1449 if (saved_herrno != -1) 1450 *errp = saved_herrno; 1451 else if (got_nodata) 1452 *errp = NO_DATA; 1453 else if (got_servfail) 1454 *errp = TRY_AGAIN; 1455 return (NULL); 1456 } 1457 1458 static int 1459 _dns_ghbyname(void *rval, void *cb_data, va_list ap) 1460 { 1461 const char *name; 1462 int af; 1463 int *errp; 1464 struct __res_type_list *rtl, rtl4; 1465 #ifdef INET6 1466 struct __res_type_list rtl6; 1467 #endif 1468 1469 name = va_arg(ap, const char *); 1470 af = va_arg(ap, int); 1471 errp = va_arg(ap, int *); 1472 1473 #ifdef INET6 1474 switch (af) { 1475 case AF_UNSPEC: 1476 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1477 SLIST_NEXT(&rtl6, rtl_entry) = &rtl4; rtl6.rtl_type = T_AAAA; 1478 rtl = &rtl6; 1479 break; 1480 case AF_INET6: 1481 SLIST_NEXT(&rtl6, rtl_entry) = NULL; rtl6.rtl_type = T_AAAA; 1482 rtl = &rtl6; 1483 break; 1484 case AF_INET: 1485 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1486 rtl = &rtl4; 1487 break; 1488 } 1489 #else 1490 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1491 rtl = &rtl4; 1492 #endif 1493 *(struct hostent **)rval = _res_search_multi(name, rtl, errp); 1494 return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND; 1495 } 1496 1497 static int 1498 _dns_ghbyaddr(void *rval, void *cb_data, va_list ap) 1499 { 1500 const void *addr; 1501 int addrlen; 1502 int af; 1503 int *errp; 1504 int n; 1505 struct hostent *hp; 1506 u_char c, *cp; 1507 char *bp; 1508 struct hostent hbuf; 1509 int na; 1510 #ifdef INET6 1511 static const char hex[] = "0123456789abcdef"; 1512 #endif 1513 querybuf buf; 1514 char qbuf[MAXDNAME+1]; 1515 char *hlist[2]; 1516 1517 addr = va_arg(ap, const void *); 1518 addrlen = va_arg(ap, int); 1519 af = va_arg(ap, int); 1520 errp = va_arg(ap, int *); 1521 1522 *(struct hostent **)rval = NULL; 1523 1524 #ifdef INET6 1525 /* XXX */ 1526 if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr)) 1527 return NS_NOTFOUND; 1528 #endif 1529 1530 if ((_res.options & RES_INIT) == 0) { 1531 if (res_init() < 0) { 1532 *errp = h_errno; 1533 return NS_UNAVAIL; 1534 } 1535 } 1536 memset(&hbuf, 0, sizeof(hbuf)); 1537 hbuf.h_name = NULL; 1538 hbuf.h_addrtype = af; 1539 hbuf.h_length = addrlen; 1540 na = 0; 1541 1542 /* XXX assumes that MAXDNAME is big enough */ 1543 n = 0; 1544 bp = qbuf; 1545 cp = (u_char *)addr+addrlen-1; 1546 switch (af) { 1547 #ifdef INET6 1548 case AF_INET6: 1549 for (; n < addrlen; n++, cp--) { 1550 c = *cp; 1551 *bp++ = hex[c & 0xf]; 1552 *bp++ = '.'; 1553 *bp++ = hex[c >> 4]; 1554 *bp++ = '.'; 1555 } 1556 strcpy(bp, "ip6.int"); 1557 break; 1558 #endif 1559 default: 1560 for (; n < addrlen; n++, cp--) { 1561 c = *cp; 1562 if (c >= 100) 1563 *bp++ = '0' + c / 100; 1564 if (c >= 10) 1565 *bp++ = '0' + (c % 100) / 10; 1566 *bp++ = '0' + c % 10; 1567 *bp++ = '.'; 1568 } 1569 strcpy(bp, "in-addr.arpa"); 1570 break; 1571 } 1572 1573 n = res_query(qbuf, C_IN, T_PTR, buf.buf, sizeof buf.buf); 1574 if (n < 0) { 1575 *errp = h_errno; 1576 return NS_UNAVAIL; 1577 } 1578 hp = getanswer(&buf, n, qbuf, T_PTR, &hbuf, errp); 1579 if (!hp) 1580 return NS_NOTFOUND; 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 *(struct hostent **)rval = _hpcopy(&hbuf, errp); 1587 return NS_SUCCESS; 1588 } 1589 1590 static void 1591 _dns_shent(int stayopen) 1592 { 1593 if ((_res.options & RES_INIT) == 0) { 1594 if (res_init() < 0) 1595 return; 1596 } 1597 if (stayopen) 1598 _res.options |= RES_STAYOPEN | RES_USEVC; 1599 } 1600 1601 static void 1602 _dns_ehent(void) 1603 { 1604 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 1605 res_close(); 1606 } 1607 1608 #ifdef ICMPNL 1609 1610 /* 1611 * experimental: 1612 * draft-ietf-ipngwg-icmp-namelookups-02.txt 1613 * ifindex is assumed to be encoded in addr. 1614 */ 1615 #include <sys/uio.h> 1616 #include <netinet/ip6.h> 1617 #include <netinet/icmp6.h> 1618 1619 struct _icmp_host_cache { 1620 struct _icmp_host_cache *hc_next; 1621 int hc_ifindex; 1622 struct in6_addr hc_addr; 1623 char *hc_name; 1624 }; 1625 1626 static char * 1627 _icmp_fqdn_query(const struct in6_addr *addr, int ifindex) 1628 { 1629 int s; 1630 struct icmp6_filter filter; 1631 struct msghdr msg; 1632 struct cmsghdr *cmsg; 1633 struct in6_pktinfo *pkt; 1634 char cbuf[256]; 1635 char buf[1024]; 1636 int cc; 1637 struct icmp6_fqdn_query *fq; 1638 struct icmp6_fqdn_reply *fr; 1639 struct _icmp_host_cache *hc; 1640 struct sockaddr_in6 sin6; 1641 struct iovec iov; 1642 fd_set s_fds, fds; 1643 struct timeval tout; 1644 int len; 1645 char *name; 1646 static int pid; 1647 static struct _icmp_host_cache *hc_head; 1648 1649 for (hc = hc_head; hc; hc = hc->hc_next) { 1650 if (hc->hc_ifindex == ifindex 1651 && IN6_ARE_ADDR_EQUAL(&hc->hc_addr, addr)) 1652 return hc->hc_name; 1653 } 1654 1655 if (pid == 0) 1656 pid = getpid(); 1657 1658 ICMP6_FILTER_SETBLOCKALL(&filter); 1659 ICMP6_FILTER_SETPASS(ICMP6_FQDN_REPLY, &filter); 1660 1661 FD_ZERO(&s_fds); 1662 tout.tv_sec = 0; 1663 tout.tv_usec = 200000; /*XXX: 200ms*/ 1664 1665 fq = (struct icmp6_fqdn_query *)buf; 1666 fq->icmp6_fqdn_type = ICMP6_FQDN_QUERY; 1667 fq->icmp6_fqdn_code = 0; 1668 fq->icmp6_fqdn_cksum = 0; 1669 fq->icmp6_fqdn_id = (u_short)pid; 1670 fq->icmp6_fqdn_unused = 0; 1671 fq->icmp6_fqdn_cookie[0] = 0; 1672 fq->icmp6_fqdn_cookie[1] = 0; 1673 1674 memset(&sin6, 0, sizeof(sin6)); 1675 sin6.sin6_family = AF_INET6; 1676 sin6.sin6_addr = *addr; 1677 1678 memset(&msg, 0, sizeof(msg)); 1679 msg.msg_name = (caddr_t)&sin6; 1680 msg.msg_namelen = sizeof(sin6); 1681 msg.msg_iov = &iov; 1682 msg.msg_iovlen = 1; 1683 msg.msg_control = NULL; 1684 msg.msg_controllen = 0; 1685 iov.iov_base = (caddr_t)buf; 1686 iov.iov_len = sizeof(struct icmp6_fqdn_query); 1687 1688 if (ifindex) { 1689 msg.msg_control = cbuf; 1690 msg.msg_controllen = sizeof(cbuf); 1691 cmsg = CMSG_FIRSTHDR(&msg); 1692 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 1693 cmsg->cmsg_level = IPPROTO_IPV6; 1694 cmsg->cmsg_type = IPV6_PKTINFO; 1695 pkt = (struct in6_pktinfo *)&cmsg[1]; 1696 memset(&pkt->ipi6_addr, 0, sizeof(struct in6_addr)); 1697 pkt->ipi6_ifindex = ifindex; 1698 cmsg = CMSG_NXTHDR(&msg, cmsg); 1699 msg.msg_controllen = (char *)cmsg - cbuf; 1700 } 1701 1702 if ((s = socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) 1703 return NULL; 1704 (void)setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, 1705 (char *)&filter, sizeof(filter)); 1706 cc = sendmsg(s, &msg, 0); 1707 if (cc < 0) { 1708 _close(s); 1709 return NULL; 1710 } 1711 FD_SET(s, &s_fds); 1712 for (;;) { 1713 fds = s_fds; 1714 if (select(s + 1, &fds, NULL, NULL, &tout) <= 0) { 1715 _close(s); 1716 return NULL; 1717 } 1718 len = sizeof(sin6); 1719 cc = recvfrom(s, buf, sizeof(buf), 0, 1720 (struct sockaddr *)&sin6, &len); 1721 if (cc <= 0) { 1722 _close(s); 1723 return NULL; 1724 } 1725 if (cc < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) 1726 continue; 1727 if (!IN6_ARE_ADDR_EQUAL(addr, &sin6.sin6_addr)) 1728 continue; 1729 fr = (struct icmp6_fqdn_reply *)(buf + sizeof(struct ip6_hdr)); 1730 if (fr->icmp6_fqdn_type == ICMP6_FQDN_REPLY) 1731 break; 1732 } 1733 _close(s); 1734 if (fr->icmp6_fqdn_cookie[1] != 0) { 1735 /* rfc1788 type */ 1736 name = buf + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 4; 1737 len = (buf + cc) - name; 1738 } else { 1739 len = fr->icmp6_fqdn_namelen; 1740 name = fr->icmp6_fqdn_name; 1741 } 1742 if (len <= 0) 1743 return NULL; 1744 name[len] = 0; 1745 1746 if ((hc = (struct _icmp_host_cache *)malloc(sizeof(*hc))) == NULL) 1747 return NULL; 1748 /* XXX: limit number of cached entries */ 1749 hc->hc_ifindex = ifindex; 1750 hc->hc_addr = *addr; 1751 hc->hc_name = strdup(name); 1752 hc->hc_next = hc_head; 1753 hc_head = hc; 1754 return hc->hc_name; 1755 } 1756 1757 static struct hostent * 1758 _icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1759 { 1760 char *hname; 1761 int ifindex; 1762 struct in6_addr addr6; 1763 1764 if (af != AF_INET6) { 1765 /* 1766 * Note: rfc1788 defines Who Are You for IPv4, 1767 * but no one implements it. 1768 */ 1769 return NULL; 1770 } 1771 1772 memcpy(&addr6, addr, addrlen); 1773 ifindex = (addr6.s6_addr[2] << 8) | addr6.s6_addr[3]; 1774 addr6.s6_addr[2] = addr6.s6_addr[3] = 0; 1775 1776 if (!IN6_IS_ADDR_LINKLOCAL(&addr6)) 1777 return NULL; /*XXX*/ 1778 1779 if ((hname = _icmp_fqdn_query(&addr6, ifindex)) == NULL) 1780 return NULL; 1781 return _hpaddr(af, hname, &addr6, errp); 1782 } 1783 #endif /* ICMPNL */ 1784