1 /* $FreeBSD: src/lib/libc/net/name6.c,v 1.6.2.9 2002/11/02 18:54:57 ume Exp $ */ 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 <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 /* Make getipnodeby*() thread-safe in libc for use with kernel threads. */ 189 #include "libc_private.h" 190 #include "spinlock.h" 191 /* 192 * XXX: Our res_*() is not thread-safe. So, we share lock between 193 * getaddrinfo() and getipnodeby*(). Still, we cannot use 194 * getaddrinfo() and getipnodeby*() in conjunction with other 195 * functions which call res_*(). 196 */ 197 extern spinlock_t __getaddrinfo_thread_lock; 198 #define THREAD_LOCK() \ 199 if (__isthreaded) _SPINLOCK(&__getaddrinfo_thread_lock); 200 #define THREAD_UNLOCK() \ 201 if (__isthreaded) _SPINUNLOCK(&__getaddrinfo_thread_lock); 202 203 /* 204 * Select order host function. 205 */ 206 #define MAXHOSTCONF 4 207 208 #ifndef HOSTCONF 209 # define HOSTCONF "/etc/host.conf" 210 #endif /* !HOSTCONF */ 211 212 struct _hostconf { 213 struct hostent *(*byname)(const char *name, int af, int *errp); 214 struct hostent *(*byaddr)(const void *addr, int addrlen, int af, int *errp); 215 }; 216 217 /* default order */ 218 static struct _hostconf _hostconf[MAXHOSTCONF] = { 219 { _dns_ghbyname, _dns_ghbyaddr }, 220 { _files_ghbyname, _files_ghbyaddr }, 221 #ifdef ICMPNL 222 { NULL, _icmp_ghbyaddr }, 223 #endif /* ICMPNL */ 224 }; 225 226 static int _hostconf_init_done; 227 static void _hostconf_init(void); 228 229 /* 230 * Initialize hostconf structure. 231 */ 232 233 static void 234 _hostconf_init(void) 235 { 236 FILE *fp; 237 int n; 238 char *p, *line; 239 char buf[BUFSIZ]; 240 241 _hostconf_init_done = 1; 242 n = 0; 243 p = HOSTCONF; 244 if ((fp = fopen(p, "r")) == NULL) 245 return; 246 while (n < MAXHOSTCONF && fgets(buf, sizeof(buf), fp)) { 247 line = buf; 248 if ((p = _hgetword(&line)) == NULL) 249 continue; 250 do { 251 if (strcmp(p, "hosts") == 0 252 || strcmp(p, "local") == 0 253 || strcmp(p, "file") == 0 254 || strcmp(p, "files") == 0) { 255 _hostconf[n].byname = _files_ghbyname; 256 _hostconf[n].byaddr = _files_ghbyaddr; 257 n++; 258 } 259 else if (strcmp(p, "dns") == 0 260 || strcmp(p, "bind") == 0) { 261 _hostconf[n].byname = _dns_ghbyname; 262 _hostconf[n].byaddr = _dns_ghbyaddr; 263 n++; 264 } 265 #ifdef YP 266 else if (strcmp(p, "nis") == 0) { 267 _hostconf[n].byname = _nis_ghbyname; 268 _hostconf[n].byaddr = _nis_ghbyaddr; 269 n++; 270 } 271 #endif 272 #ifdef ICMPNL 273 else if (strcmp(p, "icmp") == 0) { 274 _hostconf[n].byname = NULL; 275 _hostconf[n].byaddr = _icmp_ghbyaddr; 276 n++; 277 } 278 #endif /* ICMPNL */ 279 } while ((p = _hgetword(&line)) != NULL); 280 } 281 fclose(fp); 282 if (n < 0) { 283 /* no keyword found. do not change default configuration */ 284 return; 285 } 286 for (; n < MAXHOSTCONF; n++) { 287 _hostconf[n].byname = NULL; 288 _hostconf[n].byaddr = NULL; 289 } 290 } 291 292 /* 293 * Check if kernel supports mapped address. 294 * implementation dependent 295 */ 296 #ifdef __KAME__ 297 #include <sys/sysctl.h> 298 #endif /* __KAME__ */ 299 300 static int 301 _mapped_addr_enabled(void) 302 { 303 /* implementation dependent check */ 304 #if defined(__KAME__) && defined(IPV6CTL_MAPPED_ADDR) 305 int mib[4]; 306 size_t len; 307 int val; 308 309 mib[0] = CTL_NET; 310 mib[1] = PF_INET6; 311 mib[2] = IPPROTO_IPV6; 312 mib[3] = IPV6CTL_MAPPED_ADDR; 313 len = sizeof(val); 314 if (sysctl(mib, 4, &val, &len, 0, 0) == 0 && val != 0) 315 return 1; 316 #endif /* __KAME__ && IPV6CTL_MAPPED_ADDR */ 317 return 0; 318 } 319 320 /* 321 * Functions defined in RFC2553 322 * getipnodebyname, getipnodebyaddr, freehostent 323 */ 324 325 static struct hostent * 326 _ghbyname(const char *name, int af, int flags, int *errp) 327 { 328 struct hostent *hp; 329 int i; 330 331 if (flags & AI_ADDRCONFIG) { 332 int s; 333 334 /* 335 * TODO: 336 * Note that implementation dependent test for address 337 * configuration should be done everytime called 338 * (or apropriate interval), 339 * because addresses will be dynamically assigned or deleted. 340 */ 341 if (af == AF_UNSPEC) { 342 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 343 af = AF_INET; 344 else { 345 _close(s); 346 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) 347 af = AF_INET6; 348 else 349 _close(s); 350 } 351 352 } 353 if (af != AF_UNSPEC) { 354 if ((s = socket(af, SOCK_DGRAM, 0)) < 0) 355 return NULL; 356 _close(s); 357 } 358 } 359 360 THREAD_LOCK(); 361 for (i = 0; i < MAXHOSTCONF; i++) { 362 if (_hostconf[i].byname 363 && (hp = (*_hostconf[i].byname)(name, af, errp)) != NULL) { 364 THREAD_UNLOCK(); 365 return hp; 366 } 367 } 368 THREAD_UNLOCK(); 369 370 return NULL; 371 } 372 373 /* getipnodebyname() internal routine for multiple query(PF_UNSPEC) support. */ 374 struct hostent * 375 _getipnodebyname_multi(const char *name, int af, int flags, int *errp) 376 { 377 struct hostent *hp; 378 union inx_addr addrbuf; 379 380 /* XXX: PF_UNSPEC is only supposed to be passed from getaddrinfo() */ 381 if (af != AF_INET 382 #ifdef INET6 383 && af != AF_INET6 384 #endif 385 && af != PF_UNSPEC 386 ) 387 { 388 *errp = NO_RECOVERY; 389 return NULL; 390 } 391 392 #ifdef INET6 393 /* special case for literal address */ 394 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 395 if (af != AF_INET6) { 396 *errp = HOST_NOT_FOUND; 397 return NULL; 398 } 399 return _hpaddr(af, name, &addrbuf, errp); 400 } 401 #endif 402 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 403 if (af != AF_INET) { 404 if (MAPADDRENABLED(flags)) { 405 MAPADDR(&addrbuf, &addrbuf.in_addr); 406 } else { 407 *errp = HOST_NOT_FOUND; 408 return NULL; 409 } 410 } 411 return _hpaddr(af, name, &addrbuf, errp); 412 } 413 414 if (!_hostconf_init_done) 415 _hostconf_init(); 416 417 *errp = HOST_NOT_FOUND; 418 hp = _ghbyname(name, af, flags, errp); 419 420 #ifdef INET6 421 if (af == AF_INET6 422 && ((flags & AI_ALL) || hp == NULL) 423 && (MAPADDRENABLED(flags))) { 424 struct hostent *hp2 = _ghbyname(name, AF_INET, flags, errp); 425 if (hp == NULL) 426 hp = _hpmapv6(hp2, errp); 427 else { 428 if (hp2 && strcmp(hp->h_name, hp2->h_name) != 0) { 429 freehostent(hp2); 430 hp2 = NULL; 431 } 432 hp = _hpmerge(hp, hp2, errp); 433 } 434 } 435 #endif 436 return _hpsort(hp); 437 } 438 439 struct hostent * 440 getipnodebyname(const char *name, int af, int flags, int *errp) 441 { 442 if (af != AF_INET 443 #ifdef INET6 444 && af != AF_INET6 445 #endif 446 ) 447 { 448 *errp = NO_RECOVERY; 449 return NULL; 450 } 451 return(_getipnodebyname_multi(name, af ,flags, errp)); 452 } 453 454 struct hostent * 455 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 456 { 457 struct hostent *hp; 458 int i; 459 #ifdef INET6 460 struct in6_addr addrbuf; 461 #else 462 struct in_addr addrbuf; 463 #endif 464 465 *errp = HOST_NOT_FOUND; 466 467 switch (af) { 468 case AF_INET: 469 if (len != sizeof(struct in_addr)) { 470 *errp = NO_RECOVERY; 471 return NULL; 472 } 473 if ((long)src & ~(sizeof(struct in_addr) - 1)) { 474 memcpy(&addrbuf, src, len); 475 src = &addrbuf; 476 } 477 if (((struct in_addr *)src)->s_addr == 0) 478 return NULL; 479 break; 480 #ifdef INET6 481 case AF_INET6: 482 if (len != sizeof(struct in6_addr)) { 483 *errp = NO_RECOVERY; 484 return NULL; 485 } 486 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 487 memcpy(&addrbuf, src, len); 488 src = &addrbuf; 489 } 490 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 491 return NULL; 492 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 493 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 494 src = (char *)src + 495 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 496 af = AF_INET; 497 len = sizeof(struct in_addr); 498 } 499 break; 500 #endif 501 default: 502 *errp = NO_RECOVERY; 503 return NULL; 504 } 505 506 if (!_hostconf_init_done) 507 _hostconf_init(); 508 THREAD_LOCK(); 509 for (i = 0; i < MAXHOSTCONF; i++) { 510 if (_hostconf[i].byaddr 511 && (hp = (*_hostconf[i].byaddr)(src, len, af, errp)) != NULL) { 512 THREAD_UNLOCK(); 513 return hp; 514 } 515 } 516 THREAD_UNLOCK(); 517 518 return NULL; 519 } 520 521 void 522 freehostent(struct hostent *ptr) 523 { 524 free(ptr); 525 } 526 527 #if 0 528 529 /* XXX: should be deprecated */ 530 struct hostent * 531 getnodebyname(const char *name, int af, int flags) 532 { 533 return getipnodebyname(name, af, flags, &h_errno); 534 } 535 536 #ifdef __warn_references 537 __warn_references(getnodebyname, 538 "warning: getnodebyname() deprecated, " 539 "should use getaddrinfo() or getipnodebyname()"); 540 #endif 541 542 struct hostent * 543 getnodebyaddr(const void *src, size_t len, int af) 544 { 545 return getipnodebyaddr(src, len, af, &h_errno); 546 } 547 548 #ifdef __warn_references 549 __warn_references(getnodebyaddr, 550 "warning: getnodebyaddr() deprecated, " 551 "should use getnameinfo() or getipnodebyaddr()"); 552 #endif 553 554 #endif 555 556 /* 557 * Private utility functions 558 */ 559 560 /* 561 * _hpcopy: allocate and copy hostent structure 562 */ 563 static struct hostent * 564 _hpcopy(struct hostent *hp, int *errp) 565 { 566 struct hostent *nhp; 567 char *cp, **pp; 568 int size, addrsize; 569 int nalias = 0, naddr = 0; 570 int al_off; 571 int i; 572 573 if (hp == NULL) 574 return hp; 575 576 /* count size to be allocated */ 577 size = sizeof(struct hostent); 578 if (hp->h_name != NULL) 579 size += strlen(hp->h_name) + 1; 580 if ((pp = hp->h_aliases) != NULL) { 581 for (i = 0; *pp != NULL; i++, pp++) { 582 if (**pp != '\0') { 583 size += strlen(*pp) + 1; 584 nalias++; 585 } 586 } 587 } 588 /* adjust alignment */ 589 size = ALIGN(size); 590 al_off = size; 591 size += sizeof(char *) * (nalias + 1); 592 addrsize = ALIGN(hp->h_length); 593 if ((pp = hp->h_addr_list) != NULL) { 594 while (*pp++ != NULL) 595 naddr++; 596 } 597 size += addrsize * naddr; 598 size += sizeof(char *) * (naddr + 1); 599 600 /* copy */ 601 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 602 *errp = TRY_AGAIN; 603 return NULL; 604 } 605 cp = (char *)&nhp[1]; 606 if (hp->h_name != NULL) { 607 nhp->h_name = cp; 608 strcpy(cp, hp->h_name); 609 cp += strlen(cp) + 1; 610 } else 611 nhp->h_name = NULL; 612 nhp->h_aliases = (char **)((char *)nhp + al_off); 613 if ((pp = hp->h_aliases) != NULL) { 614 for (i = 0; *pp != NULL; pp++) { 615 if (**pp != '\0') { 616 nhp->h_aliases[i++] = cp; 617 strcpy(cp, *pp); 618 cp += strlen(cp) + 1; 619 } 620 } 621 } 622 nhp->h_aliases[nalias] = NULL; 623 cp = (char *)&nhp->h_aliases[nalias + 1]; 624 nhp->h_addrtype = hp->h_addrtype; 625 nhp->h_length = hp->h_length; 626 nhp->h_addr_list = (char **)cp; 627 if ((pp = hp->h_addr_list) != NULL) { 628 cp = (char *)&nhp->h_addr_list[naddr + 1]; 629 for (i = 0; *pp != NULL; pp++) { 630 nhp->h_addr_list[i++] = cp; 631 memcpy(cp, *pp, hp->h_length); 632 cp += addrsize; 633 } 634 } 635 nhp->h_addr_list[naddr] = NULL; 636 return nhp; 637 } 638 639 /* 640 * _hpaddr: construct hostent structure with one address 641 */ 642 static struct hostent * 643 _hpaddr(int af, const char *name, void *addr, int *errp) 644 { 645 struct hostent *hp, hpbuf; 646 char *addrs[2]; 647 648 hp = &hpbuf; 649 hp->h_name = (char *)name; 650 hp->h_aliases = NULL; 651 hp->h_addrtype = af; 652 hp->h_length = ADDRLEN(af); 653 hp->h_addr_list = addrs; 654 addrs[0] = (char *)addr; 655 addrs[1] = NULL; 656 return _hpcopy(hp, errp); 657 } 658 659 /* 660 * _hpmerge: merge 2 hostent structure, arguments will be freed 661 */ 662 static struct hostent * 663 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 664 { 665 int i, j; 666 int naddr, nalias; 667 char **pp; 668 struct hostent *hp, hpbuf; 669 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 670 union inx_addr addrbuf[MAXADDRS]; 671 672 if (hp1 == NULL) 673 return hp2; 674 if (hp2 == NULL) 675 return hp1; 676 677 #define HP(i) (i == 1 ? hp1 : hp2) 678 hp = &hpbuf; 679 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 680 hp->h_aliases = aliases; 681 nalias = 0; 682 for (i = 1; i <= 2; i++) { 683 if ((pp = HP(i)->h_aliases) == NULL) 684 continue; 685 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 686 /* check duplicates */ 687 for (j = 0; j < nalias; j++) 688 if (strcasecmp(*pp, aliases[j]) == 0) 689 break; 690 if (j == nalias) 691 aliases[nalias++] = *pp; 692 } 693 } 694 aliases[nalias] = NULL; 695 #ifdef INET6 696 if (hp1->h_length != hp2->h_length) { 697 hp->h_addrtype = AF_INET6; 698 hp->h_length = sizeof(struct in6_addr); 699 } else { 700 #endif 701 hp->h_addrtype = hp1->h_addrtype; 702 hp->h_length = hp1->h_length; 703 #ifdef INET6 704 } 705 #endif 706 hp->h_addr_list = addrs; 707 naddr = 0; 708 for (i = 1; i <= 2; i++) { 709 if ((pp = HP(i)->h_addr_list) == NULL) 710 continue; 711 if (HP(i)->h_length == hp->h_length) { 712 while (naddr < MAXADDRS && *pp != NULL) 713 addrs[naddr++] = *pp++; 714 } else { 715 /* copy IPv4 addr as mapped IPv6 addr */ 716 while (naddr < MAXADDRS && *pp != NULL) { 717 MAPADDR(&addrbuf[naddr], *pp++); 718 addrs[naddr] = (char *)&addrbuf[naddr]; 719 naddr++; 720 } 721 } 722 } 723 addrs[naddr] = NULL; 724 hp = _hpcopy(hp, errp); 725 freehostent(hp1); 726 freehostent(hp2); 727 return hp; 728 } 729 730 /* 731 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 732 */ 733 #ifdef INET6 734 static struct hostent * 735 _hpmapv6(struct hostent *hp, int *errp) 736 { 737 struct hostent *hp6; 738 739 if (hp == NULL) 740 return NULL; 741 if (hp->h_addrtype == AF_INET6) 742 return hp; 743 744 /* make dummy hostent to convert IPv6 address */ 745 if ((hp6 = (struct hostent *)malloc(sizeof(struct hostent))) == NULL) { 746 *errp = TRY_AGAIN; 747 return NULL; 748 } 749 hp6->h_name = NULL; 750 hp6->h_aliases = NULL; 751 hp6->h_addrtype = AF_INET6; 752 hp6->h_length = sizeof(struct in6_addr); 753 hp6->h_addr_list = NULL; 754 return _hpmerge(hp6, hp, errp); 755 } 756 #endif 757 758 /* 759 * _hpsort: sort address by sortlist 760 */ 761 static struct hostent * 762 _hpsort(struct hostent *hp) 763 { 764 int i, j, n; 765 u_char *ap, *sp, *mp, **pp; 766 char t; 767 char order[MAXADDRS]; 768 int nsort = _res.nsort; 769 770 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 771 return hp; 772 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 773 for (j = 0; j < nsort; j++) { 774 #ifdef INET6 775 if (_res_ext.sort_list[j].af != hp->h_addrtype) 776 continue; 777 sp = (u_char *)&_res_ext.sort_list[j].addr; 778 mp = (u_char *)&_res_ext.sort_list[j].mask; 779 #else 780 sp = (u_char *)&_res.sort_list[j].addr; 781 mp = (u_char *)&_res.sort_list[j].mask; 782 #endif 783 for (n = 0; n < hp->h_length; n++) { 784 if ((ap[n] & mp[n]) != sp[n]) 785 break; 786 } 787 if (n == hp->h_length) 788 break; 789 } 790 order[i] = j; 791 } 792 n = i; 793 pp = (u_char **)hp->h_addr_list; 794 for (i = 0; i < n - 1; i++) { 795 for (j = i + 1; j < n; j++) { 796 if (order[i] > order[j]) { 797 ap = pp[i]; 798 pp[i] = pp[j]; 799 pp[j] = ap; 800 t = order[i]; 801 order[i] = order[j]; 802 order[j] = t; 803 } 804 } 805 } 806 return hp; 807 } 808 809 static char * 810 _hgetword(char **pp) 811 { 812 char c, *p, *ret; 813 const char *sp; 814 static const char sep[] = "# \t\n"; 815 816 ret = NULL; 817 for (p = *pp; (c = *p) != '\0'; p++) { 818 for (sp = sep; *sp != '\0'; sp++) { 819 if (c == *sp) 820 break; 821 } 822 if (c == '#') 823 p[1] = '\0'; /* ignore rest of line */ 824 if (ret == NULL) { 825 if (*sp == '\0') 826 ret = p; 827 } else { 828 if (*sp != '\0') { 829 *p++ = '\0'; 830 break; 831 } 832 } 833 } 834 *pp = p; 835 if (ret == NULL || *ret == '\0') 836 return NULL; 837 return ret; 838 } 839 840 /* 841 * FILES (/etc/hosts) 842 */ 843 844 static FILE * 845 _files_open(int *errp) 846 { 847 FILE *fp; 848 fp = fopen(_PATH_HOSTS, "r"); 849 if (fp == NULL) 850 *errp = NO_RECOVERY; 851 return fp; 852 } 853 854 static struct hostent * 855 _files_ghbyname(const char *name, int af, int *errp) 856 { 857 int match, nalias; 858 char *p, *line, *addrstr, *cname; 859 FILE *fp; 860 struct hostent *rethp, *hp, hpbuf; 861 char *aliases[MAXALIASES + 1], *addrs[2]; 862 union inx_addr addrbuf; 863 char buf[BUFSIZ]; 864 int af0 = af; 865 866 if ((fp = _files_open(errp)) == NULL) 867 return NULL; 868 rethp = hp = NULL; 869 870 while (fgets(buf, sizeof(buf), fp)) { 871 line = buf; 872 if ((addrstr = _hgetword(&line)) == NULL 873 || (cname = _hgetword(&line)) == NULL) 874 continue; 875 match = (strcasecmp(cname, name) == 0); 876 nalias = 0; 877 while ((p = _hgetword(&line)) != NULL) { 878 if (!match) 879 match = (strcasecmp(p, name) == 0); 880 if (nalias < MAXALIASES) 881 aliases[nalias++] = p; 882 } 883 if (!match) 884 continue; 885 switch (af0) { 886 case AF_INET: 887 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 888 != 1) { 889 *errp = NO_DATA; /* name found */ 890 continue; 891 } 892 af = af0; 893 break; 894 #ifdef INET6 895 case AF_INET6: 896 if (inet_pton(af, addrstr, &addrbuf) != 1) { 897 *errp = NO_DATA; /* name found */ 898 continue; 899 } 900 af = af0; 901 break; 902 #endif 903 case AF_UNSPEC: 904 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 905 == 1) { 906 af = AF_INET; 907 break; 908 } 909 #ifdef INET6 910 if (inet_pton(AF_INET6, addrstr, &addrbuf) == 1) { 911 af = AF_INET6; 912 break; 913 } 914 #endif 915 *errp = NO_DATA; /* name found */ 916 continue; 917 /* NOTREACHED */ 918 } 919 hp = &hpbuf; 920 hp->h_name = cname; 921 hp->h_aliases = aliases; 922 aliases[nalias] = NULL; 923 hp->h_addrtype = af; 924 hp->h_length = ADDRLEN(af); 925 hp->h_addr_list = addrs; 926 addrs[0] = (char *)&addrbuf; 927 addrs[1] = NULL; 928 hp = _hpcopy(hp, errp); 929 rethp = _hpmerge(rethp, hp, errp); 930 } 931 fclose(fp); 932 return rethp; 933 } 934 935 static struct hostent * 936 _files_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 937 { 938 int nalias; 939 char *p, *line; 940 FILE *fp; 941 struct hostent *hp, hpbuf; 942 char *aliases[MAXALIASES + 1], *addrs[2]; 943 union inx_addr addrbuf; 944 char buf[BUFSIZ]; 945 946 if ((fp = _files_open(errp)) == NULL) 947 return NULL; 948 hp = NULL; 949 while (fgets(buf, sizeof(buf), fp)) { 950 line = buf; 951 if ((p = _hgetword(&line)) == NULL 952 || (af == AF_INET 953 ? inet_aton(p, (struct in_addr *)&addrbuf) 954 : inet_pton(af, p, &addrbuf)) != 1 955 || memcmp(addr, &addrbuf, addrlen) != 0 956 || (p = _hgetword(&line)) == NULL) 957 continue; 958 hp = &hpbuf; 959 hp->h_name = p; 960 hp->h_aliases = aliases; 961 nalias = 0; 962 while ((p = _hgetword(&line)) != NULL) { 963 if (nalias < MAXALIASES) 964 aliases[nalias++] = p; 965 } 966 aliases[nalias] = NULL; 967 hp->h_addrtype = af; 968 hp->h_length = addrlen; 969 hp->h_addr_list = addrs; 970 addrs[0] = (char *)&addrbuf; 971 addrs[1] = NULL; 972 hp = _hpcopy(hp, errp); 973 break; 974 } 975 fclose(fp); 976 return hp; 977 } 978 979 #ifdef YP 980 /* 981 * NIS 982 * 983 * XXX actually a hack, these are INET4 specific. 984 */ 985 static struct hostent * 986 _nis_ghbyname(const char *name, int af, int *errp) 987 { 988 struct hostent *hp = NULL; 989 990 if (af == AF_UNSPEC) 991 af = AF_INET; 992 if (af == AF_INET) { 993 hp = _gethostbynisname(name, af); 994 if (hp != NULL) 995 hp = _hpcopy(hp, errp); 996 } 997 return (hp); 998 999 } 1000 1001 static struct hostent * 1002 _nis_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1003 { 1004 struct hostent *hp = NULL; 1005 1006 if (af == AF_INET) { 1007 hp = _gethostbynisaddr(addr, addrlen, af); 1008 if (hp != NULL) 1009 hp = _hpcopy(hp, errp); 1010 } 1011 return (hp); 1012 } 1013 #endif 1014 1015 struct __res_type_list { 1016 SLIST_ENTRY(__res_type_list) rtl_entry; 1017 int rtl_type; 1018 }; 1019 1020 #define MAXPACKET (64*1024) 1021 1022 typedef union { 1023 HEADER hdr; 1024 u_char buf[MAXPACKET]; 1025 } querybuf; 1026 1027 static struct hostent *getanswer __P((const querybuf *, int, const char *, 1028 int, struct hostent *, int *)); 1029 1030 /* 1031 * we don't need to take care about sorting, nor IPv4 mapped address here. 1032 */ 1033 static struct hostent * 1034 getanswer(answer, anslen, qname, qtype, template, errp) 1035 const querybuf *answer; 1036 int anslen; 1037 const char *qname; 1038 int qtype; 1039 struct hostent *template; 1040 int *errp; 1041 { 1042 register const HEADER *hp; 1043 register const u_char *cp; 1044 register int n; 1045 const u_char *eom, *erdata; 1046 char *bp, **ap, **hap, *obp; 1047 int type, class, buflen, ancount, qdcount; 1048 int haveanswer, had_error; 1049 char tbuf[MAXDNAME]; 1050 const char *tname; 1051 int (*name_ok) __P((const char *)); 1052 static char *h_addr_ptrs[MAXADDRS + 1]; 1053 static char *host_aliases[MAXALIASES]; 1054 static char hostbuf[8*1024]; 1055 1056 #define BOUNDED_INCR(x) \ 1057 do { \ 1058 cp += x; \ 1059 if (cp > eom) { \ 1060 *errp = NO_RECOVERY; \ 1061 return (NULL); \ 1062 } \ 1063 } while (0) 1064 1065 #define BOUNDS_CHECK(ptr, count) \ 1066 do { \ 1067 if ((ptr) + (count) > eom) { \ 1068 *errp = NO_RECOVERY; \ 1069 return (NULL); \ 1070 } \ 1071 } while (0) 1072 1073 /* XXX do {} while (0) cannot be put here */ 1074 #define DNS_ASSERT(x) \ 1075 { \ 1076 if (!(x)) { \ 1077 cp += n; \ 1078 continue; \ 1079 } \ 1080 } 1081 1082 /* XXX do {} while (0) cannot be put here */ 1083 #define DNS_FATAL(x) \ 1084 { \ 1085 if (!(x)) { \ 1086 had_error++; \ 1087 continue; \ 1088 } \ 1089 } 1090 1091 tname = qname; 1092 template->h_name = NULL; 1093 eom = answer->buf + anslen; 1094 switch (qtype) { 1095 case T_A: 1096 case T_AAAA: 1097 name_ok = res_hnok; 1098 break; 1099 case T_PTR: 1100 name_ok = res_dnok; 1101 break; 1102 default: 1103 return (NULL); /* XXX should be abort(); */ 1104 } 1105 /* 1106 * find first satisfactory answer 1107 */ 1108 hp = &answer->hdr; 1109 ancount = ntohs(hp->ancount); 1110 qdcount = ntohs(hp->qdcount); 1111 bp = hostbuf; 1112 buflen = sizeof hostbuf; 1113 cp = answer->buf; 1114 BOUNDED_INCR(HFIXEDSZ); 1115 if (qdcount != 1) { 1116 *errp = NO_RECOVERY; 1117 return (NULL); 1118 } 1119 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1120 if ((n < 0) || !(*name_ok)(bp)) { 1121 *errp = NO_RECOVERY; 1122 return (NULL); 1123 } 1124 BOUNDED_INCR(n + QFIXEDSZ); 1125 if (qtype == T_A || qtype == T_AAAA) { 1126 /* res_send() has already verified that the query name is the 1127 * same as the one we sent; this just gets the expanded name 1128 * (i.e., with the succeeding search-domain tacked on). 1129 */ 1130 n = strlen(bp) + 1; /* for the \0 */ 1131 if (n >= MAXHOSTNAMELEN) { 1132 *errp = NO_RECOVERY; 1133 return (NULL); 1134 } 1135 template->h_name = bp; 1136 bp += n; 1137 buflen -= n; 1138 /* The qname can be abbreviated, but h_name is now absolute. */ 1139 qname = template->h_name; 1140 } 1141 ap = host_aliases; 1142 *ap = NULL; 1143 template->h_aliases = host_aliases; 1144 hap = h_addr_ptrs; 1145 *hap = NULL; 1146 template->h_addr_list = h_addr_ptrs; 1147 haveanswer = 0; 1148 had_error = 0; 1149 while (ancount-- > 0 && cp < eom && !had_error) { 1150 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1151 DNS_FATAL(n >= 0); 1152 DNS_FATAL((*name_ok)(bp)); 1153 cp += n; /* name */ 1154 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 1155 type = _getshort(cp); 1156 cp += INT16SZ; /* type */ 1157 class = _getshort(cp); 1158 cp += INT16SZ + INT32SZ; /* class, TTL */ 1159 n = _getshort(cp); 1160 cp += INT16SZ; /* len */ 1161 BOUNDS_CHECK(cp, n); 1162 erdata = cp + n; 1163 DNS_ASSERT(class == C_IN); 1164 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 1165 if (ap >= &host_aliases[MAXALIASES-1]) 1166 continue; 1167 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1168 DNS_FATAL(n >= 0); 1169 DNS_FATAL((*name_ok)(tbuf)); 1170 cp += n; 1171 if (cp != erdata) { 1172 *errp = NO_RECOVERY; 1173 return (NULL); 1174 } 1175 /* Store alias. */ 1176 *ap++ = bp; 1177 n = strlen(bp) + 1; /* for the \0 */ 1178 DNS_FATAL(n < MAXHOSTNAMELEN); 1179 bp += n; 1180 buflen -= n; 1181 /* Get canonical name. */ 1182 n = strlen(tbuf) + 1; /* for the \0 */ 1183 DNS_FATAL(n <= buflen); 1184 DNS_FATAL(n < MAXHOSTNAMELEN); 1185 strcpy(bp, tbuf); 1186 template->h_name = bp; 1187 bp += n; 1188 buflen -= n; 1189 continue; 1190 } 1191 if (qtype == T_PTR && type == T_CNAME) { 1192 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1193 if (n < 0 || !res_dnok(tbuf)) { 1194 had_error++; 1195 continue; 1196 } 1197 cp += n; 1198 if (cp != erdata) { 1199 *errp = NO_RECOVERY; 1200 return (NULL); 1201 } 1202 /* Get canonical name. */ 1203 n = strlen(tbuf) + 1; /* for the \0 */ 1204 if (n > buflen || n >= MAXHOSTNAMELEN) { 1205 had_error++; 1206 continue; 1207 } 1208 strcpy(bp, tbuf); 1209 tname = bp; 1210 bp += n; 1211 buflen -= n; 1212 continue; 1213 } 1214 DNS_ASSERT(type == qtype); 1215 switch (type) { 1216 case T_PTR: 1217 DNS_ASSERT(strcasecmp(tname, bp) == 0); 1218 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1219 DNS_FATAL(n >= 0); 1220 DNS_FATAL(res_hnok(bp)); 1221 #if MULTI_PTRS_ARE_ALIASES 1222 cp += n; 1223 if (cp != erdata) { 1224 *errp = NO_RECOVERY; 1225 return (NULL); 1226 } 1227 if (!haveanswer) 1228 template->h_name = bp; 1229 else if (ap < &host_aliases[MAXALIASES-1]) 1230 *ap++ = bp; 1231 else 1232 n = -1; 1233 if (n != -1) { 1234 n = strlen(bp) + 1; /* for the \0 */ 1235 if (n >= MAXHOSTNAMELEN) { 1236 had_error++; 1237 break; 1238 } 1239 bp += n; 1240 buflen -= n; 1241 } 1242 break; 1243 #else 1244 template->h_name = bp; 1245 *errp = NETDB_SUCCESS; 1246 return (template); 1247 #endif 1248 case T_A: 1249 case T_AAAA: 1250 DNS_ASSERT(strcasecmp(template->h_name, bp) == 0); 1251 DNS_ASSERT(n == template->h_length); 1252 if (!haveanswer) { 1253 register int nn; 1254 1255 template->h_name = bp; 1256 nn = strlen(bp) + 1; /* for the \0 */ 1257 bp += nn; 1258 buflen -= nn; 1259 } 1260 obp = bp; /* ALIGN rounds up */ 1261 bp = (char *)ALIGN(bp); 1262 buflen -= (bp - obp); 1263 1264 DNS_FATAL(bp + n < &hostbuf[sizeof hostbuf]); 1265 DNS_ASSERT(hap < &h_addr_ptrs[MAXADDRS-1]); 1266 #ifdef FILTER_V4MAPPED 1267 if (type == T_AAAA) { 1268 struct in6_addr in6; 1269 memcpy(&in6, cp, sizeof(in6)); 1270 DNS_ASSERT(IN6_IS_ADDR_V4MAPPED(&in6) == 0); 1271 } 1272 #endif 1273 bcopy(cp, *hap++ = bp, n); 1274 bp += n; 1275 buflen -= n; 1276 cp += n; 1277 if (cp != erdata) { 1278 *errp = NO_RECOVERY; 1279 return (NULL); 1280 } 1281 break; 1282 default: 1283 abort(); 1284 } 1285 if (!had_error) 1286 haveanswer++; 1287 } 1288 if (haveanswer) { 1289 *ap = NULL; 1290 *hap = NULL; 1291 if (!template->h_name) { 1292 n = strlen(qname) + 1; /* for the \0 */ 1293 if (n > buflen || n >= MAXHOSTNAMELEN) 1294 goto no_recovery; 1295 strcpy(bp, qname); 1296 template->h_name = bp; 1297 bp += n; 1298 buflen -= n; 1299 } 1300 *errp = NETDB_SUCCESS; 1301 return (template); 1302 } 1303 no_recovery: 1304 *errp = NO_RECOVERY; 1305 return (NULL); 1306 1307 #undef BOUNDED_INCR 1308 #undef BOUNDS_CHECK 1309 #undef DNS_ASSERT 1310 #undef DNS_FATAL 1311 } 1312 1313 /* res_search() variant with multiple query support. */ 1314 static struct hostent * 1315 _res_search_multi(name, rtl, errp) 1316 const char *name; /* domain name */ 1317 struct __res_type_list *rtl; /* list of query types */ 1318 int *errp; 1319 { 1320 const char *cp, * const *domain; 1321 struct hostent *hp0 = NULL, *hp; 1322 struct hostent hpbuf; 1323 u_int dots; 1324 int trailing_dot, ret, saved_herrno; 1325 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1326 struct __res_type_list *rtl0 = rtl; 1327 querybuf *buf; 1328 1329 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1330 *errp = NETDB_INTERNAL; 1331 return (NULL); 1332 } 1333 dots = 0; 1334 for (cp = name; *cp; cp++) 1335 dots += (*cp == '.'); 1336 trailing_dot = 0; 1337 if (cp > name && *--cp == '.') 1338 trailing_dot++; 1339 1340 buf = malloc(sizeof(*buf)); 1341 if (buf == NULL) { 1342 *errp = NETDB_INTERNAL; 1343 return NULL; 1344 } 1345 1346 /* If there aren't any dots, it could be a user-level alias */ 1347 if (!dots && (cp = hostalias(name)) != NULL) { 1348 for(rtl = rtl0; rtl != NULL; 1349 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1350 ret = res_query(cp, C_IN, rtl->rtl_type, buf->buf, 1351 sizeof(buf->buf)); 1352 if (ret > 0 && ret < sizeof(buf->buf)) { 1353 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1354 ? AF_INET6 : AF_INET; 1355 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1356 hp = getanswer(buf, ret, name, rtl->rtl_type, 1357 &hpbuf, errp); 1358 if (!hp) 1359 continue; 1360 hp = _hpcopy(&hpbuf, errp); 1361 hp0 = _hpmerge(hp0, hp, errp); 1362 } 1363 } 1364 free(buf); 1365 return (hp0); 1366 } 1367 1368 /* 1369 * If there are dots in the name already, let's just give it a try 1370 * 'as is'. The threshold can be set with the "ndots" option. 1371 */ 1372 saved_herrno = -1; 1373 if (dots >= _res.ndots) { 1374 for(rtl = rtl0; rtl != NULL; 1375 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1376 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1377 buf->buf, sizeof(buf->buf)); 1378 if (ret > 0 && ret < sizeof(buf->buf)) { 1379 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1380 ? AF_INET6 : AF_INET; 1381 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1382 hp = getanswer(buf, ret, name, rtl->rtl_type, 1383 &hpbuf, errp); 1384 if (!hp) 1385 continue; 1386 hp = _hpcopy(&hpbuf, errp); 1387 hp0 = _hpmerge(hp0, hp, errp); 1388 } 1389 } 1390 if (hp0 != NULL) { 1391 free(buf); 1392 return (hp0); 1393 } 1394 saved_herrno = *errp; 1395 tried_as_is++; 1396 } 1397 1398 /* 1399 * We do at least one level of search if 1400 * - there is no dot and RES_DEFNAME is set, or 1401 * - there is at least one dot, there is no trailing dot, 1402 * and RES_DNSRCH is set. 1403 */ 1404 if ((!dots && (_res.options & RES_DEFNAMES)) || 1405 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1406 int done = 0; 1407 1408 for (domain = (const char * const *)_res.dnsrch; 1409 *domain && !done; 1410 domain++) { 1411 1412 for(rtl = rtl0; rtl != NULL; 1413 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1414 ret = res_querydomain(name, *domain, C_IN, 1415 rtl->rtl_type, 1416 buf->buf, sizeof(buf->buf)); 1417 if (ret > 0 && ret < sizeof(buf->buf)) { 1418 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1419 ? AF_INET6 : AF_INET; 1420 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1421 hp = getanswer(buf, ret, name, 1422 rtl->rtl_type, &hpbuf, errp); 1423 if (!hp) 1424 continue; 1425 hp = _hpcopy(&hpbuf, errp); 1426 hp0 = _hpmerge(hp0, hp, errp); 1427 } 1428 } 1429 if (hp0 != NULL) { 1430 free(buf); 1431 return (hp0); 1432 } 1433 1434 /* 1435 * If no server present, give up. 1436 * If name isn't found in this domain, 1437 * keep trying higher domains in the search list 1438 * (if that's enabled). 1439 * On a NO_DATA error, keep trying, otherwise 1440 * a wildcard entry of another type could keep us 1441 * from finding this entry higher in the domain. 1442 * If we get some other error (negative answer or 1443 * server failure), then stop searching up, 1444 * but try the input name below in case it's 1445 * fully-qualified. 1446 */ 1447 if (errno == ECONNREFUSED) { 1448 free(buf); 1449 *errp = TRY_AGAIN; 1450 return (NULL); 1451 } 1452 1453 switch (*errp) { 1454 case NO_DATA: 1455 got_nodata++; 1456 /* FALLTHROUGH */ 1457 case HOST_NOT_FOUND: 1458 /* keep trying */ 1459 break; 1460 case TRY_AGAIN: 1461 if (buf->hdr.rcode == SERVFAIL) { 1462 /* try next search element, if any */ 1463 got_servfail++; 1464 break; 1465 } 1466 /* FALLTHROUGH */ 1467 default: 1468 /* anything else implies that we're done */ 1469 done++; 1470 } 1471 1472 /* if we got here for some reason other than DNSRCH, 1473 * we only wanted one iteration of the loop, so stop. 1474 */ 1475 if (!(_res.options & RES_DNSRCH)) 1476 done++; 1477 } 1478 } 1479 1480 /* 1481 * If we have not already tried the name "as is", do that now. 1482 * note that we do this regardless of how many dots were in the 1483 * name or whether it ends with a dot unless NOTLDQUERY is set. 1484 */ 1485 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 1486 for(rtl = rtl0; rtl != NULL; 1487 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1488 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1489 buf->buf, sizeof(buf->buf)); 1490 if (ret > 0 && ret < sizeof(buf->buf)) { 1491 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1492 ? AF_INET6 : AF_INET; 1493 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1494 hp = getanswer(buf, ret, name, rtl->rtl_type, 1495 &hpbuf, errp); 1496 if (!hp) 1497 continue; 1498 hp = _hpcopy(&hpbuf, errp); 1499 hp0 = _hpmerge(hp0, hp, errp); 1500 } 1501 } 1502 if (hp0 != NULL) { 1503 free(buf); 1504 return (hp0); 1505 } 1506 } 1507 1508 free(buf); 1509 1510 /* if we got here, we didn't satisfy the search. 1511 * if we did an initial full query, return that query's h_errno 1512 * (note that we wouldn't be here if that query had succeeded). 1513 * else if we ever got a nodata, send that back as the reason. 1514 * else send back meaningless h_errno, that being the one from 1515 * the last DNSRCH we did. 1516 */ 1517 if (saved_herrno != -1) 1518 *errp = saved_herrno; 1519 else if (got_nodata) 1520 *errp = NO_DATA; 1521 else if (got_servfail) 1522 *errp = TRY_AGAIN; 1523 return (NULL); 1524 } 1525 1526 static struct hostent * 1527 _dns_ghbyname(const char *name, int af, int *errp) 1528 { 1529 struct __res_type_list *rtl, rtl4; 1530 #ifdef INET6 1531 struct __res_type_list rtl6; 1532 #endif 1533 1534 #ifdef INET6 1535 switch (af) { 1536 case AF_UNSPEC: 1537 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1538 SLIST_NEXT(&rtl6, rtl_entry) = &rtl4; rtl6.rtl_type = T_AAAA; 1539 rtl = &rtl6; 1540 break; 1541 case AF_INET6: 1542 SLIST_NEXT(&rtl6, rtl_entry) = NULL; rtl6.rtl_type = T_AAAA; 1543 rtl = &rtl6; 1544 break; 1545 case AF_INET: 1546 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1547 rtl = &rtl4; 1548 break; 1549 } 1550 #else 1551 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1552 rtl = &rtl4; 1553 #endif 1554 return(_res_search_multi(name, rtl, errp)); 1555 } 1556 1557 static struct hostent * 1558 _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1559 { 1560 int n; 1561 struct hostent *hp; 1562 u_char c, *cp; 1563 char *bp; 1564 struct hostent hbuf; 1565 int na; 1566 #ifdef INET6 1567 static const char hex[] = "0123456789abcdef"; 1568 #endif 1569 querybuf *buf; 1570 char qbuf[MAXDNAME+1]; 1571 char *hlist[2]; 1572 char *tld6[] = { "ip6.arpa", "ip6.int", NULL }; 1573 char *tld4[] = { "in-addr.arpa", NULL }; 1574 char **tld; 1575 1576 #ifdef INET6 1577 /* XXX */ 1578 if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr)) 1579 return NULL; 1580 #endif 1581 1582 switch (af) { 1583 #ifdef INET6 1584 case AF_INET6: 1585 tld = tld6; 1586 break; 1587 #endif 1588 case AF_INET: 1589 tld = tld4; 1590 break; 1591 default: 1592 return NULL; 1593 } 1594 1595 if ((_res.options & RES_INIT) == 0) { 1596 if (res_init() < 0) { 1597 *errp = h_errno; 1598 return NULL; 1599 } 1600 } 1601 memset(&hbuf, 0, sizeof(hbuf)); 1602 hbuf.h_name = NULL; 1603 hbuf.h_addrtype = af; 1604 hbuf.h_length = addrlen; 1605 na = 0; 1606 1607 buf = malloc(sizeof(*buf)); 1608 if (buf == NULL) { 1609 *errp = NETDB_INTERNAL; 1610 return NULL; 1611 } 1612 for (/* nothing */; *tld; tld++) { 1613 /* 1614 * XXX assumes that MAXDNAME is big enough - error checks 1615 * has been made by callers 1616 */ 1617 n = 0; 1618 bp = qbuf; 1619 cp = (u_char *)addr+addrlen-1; 1620 switch (af) { 1621 #ifdef INET6 1622 case AF_INET6: 1623 for (; n < addrlen; n++, cp--) { 1624 c = *cp; 1625 *bp++ = hex[c & 0xf]; 1626 *bp++ = '.'; 1627 *bp++ = hex[c >> 4]; 1628 *bp++ = '.'; 1629 } 1630 strcpy(bp, *tld); 1631 break; 1632 #endif 1633 case AF_INET: 1634 for (; n < addrlen; n++, cp--) { 1635 c = *cp; 1636 if (c >= 100) 1637 *bp++ = '0' + c / 100; 1638 if (c >= 10) 1639 *bp++ = '0' + (c % 100) / 10; 1640 *bp++ = '0' + c % 10; 1641 *bp++ = '.'; 1642 } 1643 strcpy(bp, *tld); 1644 break; 1645 } 1646 1647 n = res_query(qbuf, C_IN, T_PTR, buf->buf, sizeof buf->buf); 1648 if (n < 0) { 1649 *errp = h_errno; 1650 continue; 1651 } else if (n > sizeof(buf->buf)) { 1652 *errp = NETDB_INTERNAL; 1653 #if 0 1654 errno = ERANGE; /* XXX is it OK to set errno here? */ 1655 #endif 1656 continue; 1657 } 1658 hp = getanswer(buf, n, qbuf, T_PTR, &hbuf, errp); 1659 if (!hp) 1660 continue; 1661 free(buf); 1662 hbuf.h_addrtype = af; 1663 hbuf.h_length = addrlen; 1664 hbuf.h_addr_list = hlist; 1665 hlist[0] = (char *)addr; 1666 hlist[1] = NULL; 1667 return _hpcopy(&hbuf, errp); 1668 } 1669 free(buf); 1670 return NULL; 1671 } 1672 1673 static void 1674 _dns_shent(int stayopen) 1675 { 1676 if ((_res.options & RES_INIT) == 0) { 1677 if (res_init() < 0) 1678 return; 1679 } 1680 if (stayopen) 1681 _res.options |= RES_STAYOPEN | RES_USEVC; 1682 } 1683 1684 static void 1685 _dns_ehent(void) 1686 { 1687 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 1688 res_close(); 1689 } 1690 1691 #ifdef ICMPNL 1692 1693 /* 1694 * experimental: 1695 * draft-ietf-ipngwg-icmp-namelookups-02.txt 1696 * ifindex is assumed to be encoded in addr. 1697 */ 1698 #include <sys/uio.h> 1699 #include <netinet/ip6.h> 1700 #include <netinet/icmp6.h> 1701 1702 struct _icmp_host_cache { 1703 struct _icmp_host_cache *hc_next; 1704 int hc_ifindex; 1705 struct in6_addr hc_addr; 1706 char *hc_name; 1707 }; 1708 1709 static char * 1710 _icmp_fqdn_query(const struct in6_addr *addr, int ifindex) 1711 { 1712 int s; 1713 struct icmp6_filter filter; 1714 struct msghdr msg; 1715 struct cmsghdr *cmsg; 1716 struct in6_pktinfo *pkt; 1717 char cbuf[256]; 1718 char buf[1024]; 1719 int cc; 1720 struct icmp6_fqdn_query *fq; 1721 struct icmp6_fqdn_reply *fr; 1722 struct _icmp_host_cache *hc; 1723 struct sockaddr_in6 sin6; 1724 struct iovec iov; 1725 fd_set s_fds, fds; 1726 struct timeval tout; 1727 int len; 1728 char *name; 1729 static int pid; 1730 static struct _icmp_host_cache *hc_head; 1731 1732 for (hc = hc_head; hc; hc = hc->hc_next) { 1733 if (hc->hc_ifindex == ifindex 1734 && IN6_ARE_ADDR_EQUAL(&hc->hc_addr, addr)) 1735 return hc->hc_name; 1736 } 1737 1738 if (pid == 0) 1739 pid = getpid(); 1740 1741 ICMP6_FILTER_SETBLOCKALL(&filter); 1742 ICMP6_FILTER_SETPASS(ICMP6_FQDN_REPLY, &filter); 1743 1744 FD_ZERO(&s_fds); 1745 tout.tv_sec = 0; 1746 tout.tv_usec = 200000; /*XXX: 200ms*/ 1747 1748 fq = (struct icmp6_fqdn_query *)buf; 1749 fq->icmp6_fqdn_type = ICMP6_FQDN_QUERY; 1750 fq->icmp6_fqdn_code = 0; 1751 fq->icmp6_fqdn_cksum = 0; 1752 fq->icmp6_fqdn_id = (u_short)pid; 1753 fq->icmp6_fqdn_unused = 0; 1754 fq->icmp6_fqdn_cookie[0] = 0; 1755 fq->icmp6_fqdn_cookie[1] = 0; 1756 1757 memset(&sin6, 0, sizeof(sin6)); 1758 sin6.sin6_family = AF_INET6; 1759 sin6.sin6_addr = *addr; 1760 1761 memset(&msg, 0, sizeof(msg)); 1762 msg.msg_name = (caddr_t)&sin6; 1763 msg.msg_namelen = sizeof(sin6); 1764 msg.msg_iov = &iov; 1765 msg.msg_iovlen = 1; 1766 msg.msg_control = NULL; 1767 msg.msg_controllen = 0; 1768 iov.iov_base = (caddr_t)buf; 1769 iov.iov_len = sizeof(struct icmp6_fqdn_query); 1770 1771 if (ifindex) { 1772 msg.msg_control = cbuf; 1773 msg.msg_controllen = sizeof(cbuf); 1774 cmsg = CMSG_FIRSTHDR(&msg); 1775 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 1776 cmsg->cmsg_level = IPPROTO_IPV6; 1777 cmsg->cmsg_type = IPV6_PKTINFO; 1778 pkt = (struct in6_pktinfo *)&cmsg[1]; 1779 memset(&pkt->ipi6_addr, 0, sizeof(struct in6_addr)); 1780 pkt->ipi6_ifindex = ifindex; 1781 cmsg = CMSG_NXTHDR(&msg, cmsg); 1782 msg.msg_controllen = (char *)cmsg - cbuf; 1783 } 1784 1785 if ((s = socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) 1786 return NULL; 1787 (void)setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, 1788 (char *)&filter, sizeof(filter)); 1789 cc = sendmsg(s, &msg, 0); 1790 if (cc < 0) { 1791 _close(s); 1792 return NULL; 1793 } 1794 FD_SET(s, &s_fds); 1795 for (;;) { 1796 fds = s_fds; 1797 if (select(s + 1, &fds, NULL, NULL, &tout) <= 0) { 1798 _close(s); 1799 return NULL; 1800 } 1801 len = sizeof(sin6); 1802 cc = recvfrom(s, buf, sizeof(buf), 0, 1803 (struct sockaddr *)&sin6, &len); 1804 if (cc <= 0) { 1805 _close(s); 1806 return NULL; 1807 } 1808 if (cc < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) 1809 continue; 1810 if (!IN6_ARE_ADDR_EQUAL(addr, &sin6.sin6_addr)) 1811 continue; 1812 fr = (struct icmp6_fqdn_reply *)(buf + sizeof(struct ip6_hdr)); 1813 if (fr->icmp6_fqdn_type == ICMP6_FQDN_REPLY) 1814 break; 1815 } 1816 _close(s); 1817 if (fr->icmp6_fqdn_cookie[1] != 0) { 1818 /* rfc1788 type */ 1819 name = buf + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 4; 1820 len = (buf + cc) - name; 1821 } else { 1822 len = fr->icmp6_fqdn_namelen; 1823 name = fr->icmp6_fqdn_name; 1824 } 1825 if (len <= 0) 1826 return NULL; 1827 name[len] = 0; 1828 1829 if ((hc = (struct _icmp_host_cache *)malloc(sizeof(*hc))) == NULL) 1830 return NULL; 1831 /* XXX: limit number of cached entries */ 1832 hc->hc_ifindex = ifindex; 1833 hc->hc_addr = *addr; 1834 hc->hc_name = strdup(name); 1835 hc->hc_next = hc_head; 1836 hc_head = hc; 1837 return hc->hc_name; 1838 } 1839 1840 static struct hostent * 1841 _icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1842 { 1843 char *hname; 1844 int ifindex; 1845 struct in6_addr addr6; 1846 1847 if (af != AF_INET6) { 1848 /* 1849 * Note: rfc1788 defines Who Are You for IPv4, 1850 * but no one implements it. 1851 */ 1852 return NULL; 1853 } 1854 1855 memcpy(&addr6, addr, addrlen); 1856 ifindex = (addr6.s6_addr[2] << 8) | addr6.s6_addr[3]; 1857 addr6.s6_addr[2] = addr6.s6_addr[3] = 0; 1858 1859 if (!IN6_IS_ADDR_LINKLOCAL(&addr6)) 1860 return NULL; /*XXX*/ 1861 1862 if ((hname = _icmp_fqdn_query(&addr6, ifindex)) == NULL) 1863 return NULL; 1864 return _hpaddr(af, hname, &addr6, errp); 1865 } 1866 #endif /* ICMPNL */ 1867