1 /* $FreeBSD: src/lib/libc/net/name6.c,v 1.6.2.9 2002/11/02 18:54:57 ume Exp $ */ 2 /* $DragonFly: src/lib/libc/net/name6.c,v 1.2 2003/06/17 04:26:44 dillon Exp $ */ 3 /* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 itojun Exp $ */ 4 5 /* 6 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 /* 34 * ++Copyright++ 1985, 1988, 1993 35 * - 36 * Copyright (c) 1985, 1988, 1993 37 * The Regents of the University of California. All rights reserved. 38 * 39 * Redistribution and use in source and binary forms, with or without 40 * modification, are permitted provided that the following conditions 41 * are met: 42 * 1. Redistributions of source code must retain the above copyright 43 * notice, this list of conditions and the following disclaimer. 44 * 2. Redistributions in binary form must reproduce the above copyright 45 * notice, this list of conditions and the following disclaimer in the 46 * documentation and/or other materials provided with the distribution. 47 * 3. All advertising materials mentioning features or use of this software 48 * must display the following acknowledgement: 49 * This product includes software developed by the University of 50 * California, Berkeley and its contributors. 51 * 4. Neither the name of the University nor the names of its contributors 52 * may be used to endorse or promote products derived from this software 53 * without specific prior written permission. 54 * 55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 58 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 65 * SUCH DAMAGE. 66 * - 67 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 68 * 69 * Permission to use, copy, modify, and distribute this software for any 70 * purpose with or without fee is hereby granted, provided that the above 71 * copyright notice and this permission notice appear in all copies, and that 72 * the name of Digital Equipment Corporation not be used in advertising or 73 * publicity pertaining to distribution of the document or software without 74 * specific, written prior permission. 75 * 76 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 77 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 78 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 79 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 80 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 81 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 82 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 83 * SOFTWARE. 84 * - 85 * --Copyright-- 86 */ 87 88 /* 89 * Atsushi Onoe <onoe@sm.sony.co.jp> 90 */ 91 92 /* 93 * TODO for thread safe 94 * use mutex for _hostconf, _hostconf_init. 95 * rewrite resolvers to be thread safe 96 */ 97 98 #include <sys/param.h> 99 #include <sys/socket.h> 100 #include <sys/time.h> 101 #include <sys/queue.h> 102 #include <netinet/in.h> 103 104 #include <arpa/inet.h> 105 #include <arpa/nameser.h> 106 107 #include <errno.h> 108 #include <netdb.h> 109 #include <resolv.h> 110 #include <stdio.h> 111 #include <stdlib.h> 112 #include <string.h> 113 #include <unistd.h> 114 115 #ifndef _PATH_HOSTS 116 #define _PATH_HOSTS "/etc/hosts" 117 #endif 118 119 #ifndef MAXALIASES 120 #define MAXALIASES 10 121 #endif 122 #ifndef MAXADDRS 123 #define MAXADDRS 20 124 #endif 125 #ifndef MAXDNAME 126 #define MAXDNAME 1025 127 #endif 128 129 #ifdef INET6 130 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 131 sizeof(struct in_addr)) 132 #else 133 #define ADDRLEN(af) sizeof(struct in_addr) 134 #endif 135 136 #define MAPADDR(ab, ina) \ 137 do { \ 138 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 139 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 140 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 141 } while (0) 142 #define MAPADDRENABLED(flags) \ 143 (((flags) & AI_V4MAPPED) || \ 144 (((flags) & AI_V4MAPPED_CFG) && _mapped_addr_enabled())) 145 146 union inx_addr { 147 struct in_addr in_addr; 148 #ifdef INET6 149 struct in6_addr in6_addr; 150 #endif 151 struct { 152 u_char mau_zero[10]; 153 u_char mau_one[2]; 154 struct in_addr mau_inaddr; 155 } map_addr_un; 156 #define map_zero map_addr_un.mau_zero 157 #define map_one map_addr_un.mau_one 158 #define map_inaddr map_addr_un.mau_inaddr 159 }; 160 161 static struct hostent *_hpcopy(struct hostent *hp, int *errp); 162 static struct hostent *_hpaddr(int af, const char *name, void *addr, int *errp); 163 static struct hostent *_hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp); 164 #ifdef INET6 165 static struct hostent *_hpmapv6(struct hostent *hp, int *errp); 166 #endif 167 static struct hostent *_hpsort(struct hostent *hp); 168 static struct hostent *_ghbyname(const char *name, int af, int flags, int *errp); 169 static char *_hgetword(char **pp); 170 static int _mapped_addr_enabled(void); 171 172 static FILE *_files_open(int *errp); 173 static struct hostent *_files_ghbyname(const char *name, int af, int *errp); 174 static struct hostent *_files_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 175 static void _files_shent(int stayopen); 176 static void _files_ehent(void); 177 #ifdef YP 178 static struct hostent *_nis_ghbyname(const char *name, int af, int *errp); 179 static struct hostent *_nis_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 180 #endif 181 static struct hostent *_dns_ghbyname(const char *name, int af, int *errp); 182 static struct hostent *_dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 183 static void _dns_shent(int stayopen); 184 static void _dns_ehent(void); 185 #ifdef ICMPNL 186 static struct hostent *_icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp); 187 #endif /* ICMPNL */ 188 189 /* Make getipnodeby*() thread-safe in libc for use with kernel threads. */ 190 #include "libc_private.h" 191 #include "spinlock.h" 192 /* 193 * XXX: Our res_*() is not thread-safe. So, we share lock between 194 * getaddrinfo() and getipnodeby*(). Still, we cannot use 195 * getaddrinfo() and getipnodeby*() in conjunction with other 196 * functions which call res_*(). 197 */ 198 extern spinlock_t __getaddrinfo_thread_lock; 199 #define THREAD_LOCK() \ 200 if (__isthreaded) _SPINLOCK(&__getaddrinfo_thread_lock); 201 #define THREAD_UNLOCK() \ 202 if (__isthreaded) _SPINUNLOCK(&__getaddrinfo_thread_lock); 203 204 /* 205 * Select order host function. 206 */ 207 #define MAXHOSTCONF 4 208 209 #ifndef HOSTCONF 210 # define HOSTCONF "/etc/host.conf" 211 #endif /* !HOSTCONF */ 212 213 struct _hostconf { 214 struct hostent *(*byname)(const char *name, int af, int *errp); 215 struct hostent *(*byaddr)(const void *addr, int addrlen, int af, int *errp); 216 }; 217 218 /* default order */ 219 static struct _hostconf _hostconf[MAXHOSTCONF] = { 220 { _dns_ghbyname, _dns_ghbyaddr }, 221 { _files_ghbyname, _files_ghbyaddr }, 222 #ifdef ICMPNL 223 { NULL, _icmp_ghbyaddr }, 224 #endif /* ICMPNL */ 225 }; 226 227 static int _hostconf_init_done; 228 static void _hostconf_init(void); 229 230 /* 231 * Initialize hostconf structure. 232 */ 233 234 static void 235 _hostconf_init(void) 236 { 237 FILE *fp; 238 int n; 239 char *p, *line; 240 char buf[BUFSIZ]; 241 242 _hostconf_init_done = 1; 243 n = 0; 244 p = HOSTCONF; 245 if ((fp = fopen(p, "r")) == NULL) 246 return; 247 while (n < MAXHOSTCONF && fgets(buf, sizeof(buf), fp)) { 248 line = buf; 249 if ((p = _hgetword(&line)) == NULL) 250 continue; 251 do { 252 if (strcmp(p, "hosts") == 0 253 || strcmp(p, "local") == 0 254 || strcmp(p, "file") == 0 255 || strcmp(p, "files") == 0) { 256 _hostconf[n].byname = _files_ghbyname; 257 _hostconf[n].byaddr = _files_ghbyaddr; 258 n++; 259 } 260 else if (strcmp(p, "dns") == 0 261 || strcmp(p, "bind") == 0) { 262 _hostconf[n].byname = _dns_ghbyname; 263 _hostconf[n].byaddr = _dns_ghbyaddr; 264 n++; 265 } 266 #ifdef YP 267 else if (strcmp(p, "nis") == 0) { 268 _hostconf[n].byname = _nis_ghbyname; 269 _hostconf[n].byaddr = _nis_ghbyaddr; 270 n++; 271 } 272 #endif 273 #ifdef ICMPNL 274 else if (strcmp(p, "icmp") == 0) { 275 _hostconf[n].byname = NULL; 276 _hostconf[n].byaddr = _icmp_ghbyaddr; 277 n++; 278 } 279 #endif /* ICMPNL */ 280 } while ((p = _hgetword(&line)) != NULL); 281 } 282 fclose(fp); 283 if (n < 0) { 284 /* no keyword found. do not change default configuration */ 285 return; 286 } 287 for (; n < MAXHOSTCONF; n++) { 288 _hostconf[n].byname = NULL; 289 _hostconf[n].byaddr = NULL; 290 } 291 } 292 293 /* 294 * Check if kernel supports mapped address. 295 * implementation dependent 296 */ 297 #ifdef __KAME__ 298 #include <sys/sysctl.h> 299 #endif /* __KAME__ */ 300 301 static int 302 _mapped_addr_enabled(void) 303 { 304 /* implementation dependent check */ 305 #if defined(__KAME__) && defined(IPV6CTL_MAPPED_ADDR) 306 int mib[4]; 307 size_t len; 308 int val; 309 310 mib[0] = CTL_NET; 311 mib[1] = PF_INET6; 312 mib[2] = IPPROTO_IPV6; 313 mib[3] = IPV6CTL_MAPPED_ADDR; 314 len = sizeof(val); 315 if (sysctl(mib, 4, &val, &len, 0, 0) == 0 && val != 0) 316 return 1; 317 #endif /* __KAME__ && IPV6CTL_MAPPED_ADDR */ 318 return 0; 319 } 320 321 /* 322 * Functions defined in RFC2553 323 * getipnodebyname, getipnodebyaddr, freehostent 324 */ 325 326 static struct hostent * 327 _ghbyname(const char *name, int af, int flags, int *errp) 328 { 329 struct hostent *hp; 330 int i; 331 332 if (flags & AI_ADDRCONFIG) { 333 int s; 334 335 /* 336 * TODO: 337 * Note that implementation dependent test for address 338 * configuration should be done everytime called 339 * (or apropriate interval), 340 * because addresses will be dynamically assigned or deleted. 341 */ 342 if (af == AF_UNSPEC) { 343 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 344 af = AF_INET; 345 else { 346 _close(s); 347 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) 348 af = AF_INET6; 349 else 350 _close(s); 351 } 352 353 } 354 if (af != AF_UNSPEC) { 355 if ((s = socket(af, SOCK_DGRAM, 0)) < 0) 356 return NULL; 357 _close(s); 358 } 359 } 360 361 THREAD_LOCK(); 362 for (i = 0; i < MAXHOSTCONF; i++) { 363 if (_hostconf[i].byname 364 && (hp = (*_hostconf[i].byname)(name, af, errp)) != NULL) { 365 THREAD_UNLOCK(); 366 return hp; 367 } 368 } 369 THREAD_UNLOCK(); 370 371 return NULL; 372 } 373 374 /* getipnodebyname() internal routine for multiple query(PF_UNSPEC) support. */ 375 struct hostent * 376 _getipnodebyname_multi(const char *name, int af, int flags, int *errp) 377 { 378 struct hostent *hp; 379 union inx_addr addrbuf; 380 381 /* XXX: PF_UNSPEC is only supposed to be passed from getaddrinfo() */ 382 if (af != AF_INET 383 #ifdef INET6 384 && af != AF_INET6 385 #endif 386 && af != PF_UNSPEC 387 ) 388 { 389 *errp = NO_RECOVERY; 390 return NULL; 391 } 392 393 #ifdef INET6 394 /* special case for literal address */ 395 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 396 if (af != AF_INET6) { 397 *errp = HOST_NOT_FOUND; 398 return NULL; 399 } 400 return _hpaddr(af, name, &addrbuf, errp); 401 } 402 #endif 403 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 404 if (af != AF_INET) { 405 if (MAPADDRENABLED(flags)) { 406 MAPADDR(&addrbuf, &addrbuf.in_addr); 407 } else { 408 *errp = HOST_NOT_FOUND; 409 return NULL; 410 } 411 } 412 return _hpaddr(af, name, &addrbuf, errp); 413 } 414 415 if (!_hostconf_init_done) 416 _hostconf_init(); 417 418 *errp = HOST_NOT_FOUND; 419 hp = _ghbyname(name, af, flags, errp); 420 421 #ifdef INET6 422 if (af == AF_INET6 423 && ((flags & AI_ALL) || hp == NULL) 424 && (MAPADDRENABLED(flags))) { 425 struct hostent *hp2 = _ghbyname(name, AF_INET, flags, errp); 426 if (hp == NULL) 427 hp = _hpmapv6(hp2, errp); 428 else { 429 if (hp2 && strcmp(hp->h_name, hp2->h_name) != 0) { 430 freehostent(hp2); 431 hp2 = NULL; 432 } 433 hp = _hpmerge(hp, hp2, errp); 434 } 435 } 436 #endif 437 return _hpsort(hp); 438 } 439 440 struct hostent * 441 getipnodebyname(const char *name, int af, int flags, int *errp) 442 { 443 if (af != AF_INET 444 #ifdef INET6 445 && af != AF_INET6 446 #endif 447 ) 448 { 449 *errp = NO_RECOVERY; 450 return NULL; 451 } 452 return(_getipnodebyname_multi(name, af ,flags, errp)); 453 } 454 455 struct hostent * 456 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 457 { 458 struct hostent *hp; 459 int i; 460 #ifdef INET6 461 struct in6_addr addrbuf; 462 #else 463 struct in_addr addrbuf; 464 #endif 465 466 *errp = HOST_NOT_FOUND; 467 468 switch (af) { 469 case AF_INET: 470 if (len != sizeof(struct in_addr)) { 471 *errp = NO_RECOVERY; 472 return NULL; 473 } 474 if ((long)src & ~(sizeof(struct in_addr) - 1)) { 475 memcpy(&addrbuf, src, len); 476 src = &addrbuf; 477 } 478 if (((struct in_addr *)src)->s_addr == 0) 479 return NULL; 480 break; 481 #ifdef INET6 482 case AF_INET6: 483 if (len != sizeof(struct in6_addr)) { 484 *errp = NO_RECOVERY; 485 return NULL; 486 } 487 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 488 memcpy(&addrbuf, src, len); 489 src = &addrbuf; 490 } 491 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 492 return NULL; 493 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 494 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 495 src = (char *)src + 496 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 497 af = AF_INET; 498 len = sizeof(struct in_addr); 499 } 500 break; 501 #endif 502 default: 503 *errp = NO_RECOVERY; 504 return NULL; 505 } 506 507 if (!_hostconf_init_done) 508 _hostconf_init(); 509 THREAD_LOCK(); 510 for (i = 0; i < MAXHOSTCONF; i++) { 511 if (_hostconf[i].byaddr 512 && (hp = (*_hostconf[i].byaddr)(src, len, af, errp)) != NULL) { 513 THREAD_UNLOCK(); 514 return hp; 515 } 516 } 517 THREAD_UNLOCK(); 518 519 return NULL; 520 } 521 522 void 523 freehostent(struct hostent *ptr) 524 { 525 free(ptr); 526 } 527 528 #if 0 529 530 /* XXX: should be deprecated */ 531 struct hostent * 532 getnodebyname(const char *name, int af, int flags) 533 { 534 return getipnodebyname(name, af, flags, &h_errno); 535 } 536 537 #ifdef __warn_references 538 __warn_references(getnodebyname, 539 "warning: getnodebyname() deprecated, " 540 "should use getaddrinfo() or getipnodebyname()"); 541 #endif 542 543 struct hostent * 544 getnodebyaddr(const void *src, size_t len, int af) 545 { 546 return getipnodebyaddr(src, len, af, &h_errno); 547 } 548 549 #ifdef __warn_references 550 __warn_references(getnodebyaddr, 551 "warning: getnodebyaddr() deprecated, " 552 "should use getnameinfo() or getipnodebyaddr()"); 553 #endif 554 555 #endif 556 557 /* 558 * Private utility functions 559 */ 560 561 /* 562 * _hpcopy: allocate and copy hostent structure 563 */ 564 static struct hostent * 565 _hpcopy(struct hostent *hp, int *errp) 566 { 567 struct hostent *nhp; 568 char *cp, **pp; 569 int size, addrsize; 570 int nalias = 0, naddr = 0; 571 int al_off; 572 int i; 573 574 if (hp == NULL) 575 return hp; 576 577 /* count size to be allocated */ 578 size = sizeof(struct hostent); 579 if (hp->h_name != NULL) 580 size += strlen(hp->h_name) + 1; 581 if ((pp = hp->h_aliases) != NULL) { 582 for (i = 0; *pp != NULL; i++, pp++) { 583 if (**pp != '\0') { 584 size += strlen(*pp) + 1; 585 nalias++; 586 } 587 } 588 } 589 /* adjust alignment */ 590 size = ALIGN(size); 591 al_off = size; 592 size += sizeof(char *) * (nalias + 1); 593 addrsize = ALIGN(hp->h_length); 594 if ((pp = hp->h_addr_list) != NULL) { 595 while (*pp++ != NULL) 596 naddr++; 597 } 598 size += addrsize * naddr; 599 size += sizeof(char *) * (naddr + 1); 600 601 /* copy */ 602 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 603 *errp = TRY_AGAIN; 604 return NULL; 605 } 606 cp = (char *)&nhp[1]; 607 if (hp->h_name != NULL) { 608 nhp->h_name = cp; 609 strcpy(cp, hp->h_name); 610 cp += strlen(cp) + 1; 611 } else 612 nhp->h_name = NULL; 613 nhp->h_aliases = (char **)((char *)nhp + al_off); 614 if ((pp = hp->h_aliases) != NULL) { 615 for (i = 0; *pp != NULL; pp++) { 616 if (**pp != '\0') { 617 nhp->h_aliases[i++] = cp; 618 strcpy(cp, *pp); 619 cp += strlen(cp) + 1; 620 } 621 } 622 } 623 nhp->h_aliases[nalias] = NULL; 624 cp = (char *)&nhp->h_aliases[nalias + 1]; 625 nhp->h_addrtype = hp->h_addrtype; 626 nhp->h_length = hp->h_length; 627 nhp->h_addr_list = (char **)cp; 628 if ((pp = hp->h_addr_list) != NULL) { 629 cp = (char *)&nhp->h_addr_list[naddr + 1]; 630 for (i = 0; *pp != NULL; pp++) { 631 nhp->h_addr_list[i++] = cp; 632 memcpy(cp, *pp, hp->h_length); 633 cp += addrsize; 634 } 635 } 636 nhp->h_addr_list[naddr] = NULL; 637 return nhp; 638 } 639 640 /* 641 * _hpaddr: construct hostent structure with one address 642 */ 643 static struct hostent * 644 _hpaddr(int af, const char *name, void *addr, int *errp) 645 { 646 struct hostent *hp, hpbuf; 647 char *addrs[2]; 648 649 hp = &hpbuf; 650 hp->h_name = (char *)name; 651 hp->h_aliases = NULL; 652 hp->h_addrtype = af; 653 hp->h_length = ADDRLEN(af); 654 hp->h_addr_list = addrs; 655 addrs[0] = (char *)addr; 656 addrs[1] = NULL; 657 return _hpcopy(hp, errp); 658 } 659 660 /* 661 * _hpmerge: merge 2 hostent structure, arguments will be freed 662 */ 663 static struct hostent * 664 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 665 { 666 int i, j; 667 int naddr, nalias; 668 char **pp; 669 struct hostent *hp, hpbuf; 670 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 671 union inx_addr addrbuf[MAXADDRS]; 672 673 if (hp1 == NULL) 674 return hp2; 675 if (hp2 == NULL) 676 return hp1; 677 678 #define HP(i) (i == 1 ? hp1 : hp2) 679 hp = &hpbuf; 680 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 681 hp->h_aliases = aliases; 682 nalias = 0; 683 for (i = 1; i <= 2; i++) { 684 if ((pp = HP(i)->h_aliases) == NULL) 685 continue; 686 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 687 /* check duplicates */ 688 for (j = 0; j < nalias; j++) 689 if (strcasecmp(*pp, aliases[j]) == 0) 690 break; 691 if (j == nalias) 692 aliases[nalias++] = *pp; 693 } 694 } 695 aliases[nalias] = NULL; 696 #ifdef INET6 697 if (hp1->h_length != hp2->h_length) { 698 hp->h_addrtype = AF_INET6; 699 hp->h_length = sizeof(struct in6_addr); 700 } else { 701 #endif 702 hp->h_addrtype = hp1->h_addrtype; 703 hp->h_length = hp1->h_length; 704 #ifdef INET6 705 } 706 #endif 707 hp->h_addr_list = addrs; 708 naddr = 0; 709 for (i = 1; i <= 2; i++) { 710 if ((pp = HP(i)->h_addr_list) == NULL) 711 continue; 712 if (HP(i)->h_length == hp->h_length) { 713 while (naddr < MAXADDRS && *pp != NULL) 714 addrs[naddr++] = *pp++; 715 } else { 716 /* copy IPv4 addr as mapped IPv6 addr */ 717 while (naddr < MAXADDRS && *pp != NULL) { 718 MAPADDR(&addrbuf[naddr], *pp++); 719 addrs[naddr] = (char *)&addrbuf[naddr]; 720 naddr++; 721 } 722 } 723 } 724 addrs[naddr] = NULL; 725 hp = _hpcopy(hp, errp); 726 freehostent(hp1); 727 freehostent(hp2); 728 return hp; 729 } 730 731 /* 732 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 733 */ 734 #ifdef INET6 735 static struct hostent * 736 _hpmapv6(struct hostent *hp, int *errp) 737 { 738 struct hostent *hp6; 739 740 if (hp == NULL) 741 return NULL; 742 if (hp->h_addrtype == AF_INET6) 743 return hp; 744 745 /* make dummy hostent to convert IPv6 address */ 746 if ((hp6 = (struct hostent *)malloc(sizeof(struct hostent))) == NULL) { 747 *errp = TRY_AGAIN; 748 return NULL; 749 } 750 hp6->h_name = NULL; 751 hp6->h_aliases = NULL; 752 hp6->h_addrtype = AF_INET6; 753 hp6->h_length = sizeof(struct in6_addr); 754 hp6->h_addr_list = NULL; 755 return _hpmerge(hp6, hp, errp); 756 } 757 #endif 758 759 /* 760 * _hpsort: sort address by sortlist 761 */ 762 static struct hostent * 763 _hpsort(struct hostent *hp) 764 { 765 int i, j, n; 766 u_char *ap, *sp, *mp, **pp; 767 char t; 768 char order[MAXADDRS]; 769 int nsort = _res.nsort; 770 771 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 772 return hp; 773 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 774 for (j = 0; j < nsort; j++) { 775 #ifdef INET6 776 if (_res_ext.sort_list[j].af != hp->h_addrtype) 777 continue; 778 sp = (u_char *)&_res_ext.sort_list[j].addr; 779 mp = (u_char *)&_res_ext.sort_list[j].mask; 780 #else 781 sp = (u_char *)&_res.sort_list[j].addr; 782 mp = (u_char *)&_res.sort_list[j].mask; 783 #endif 784 for (n = 0; n < hp->h_length; n++) { 785 if ((ap[n] & mp[n]) != sp[n]) 786 break; 787 } 788 if (n == hp->h_length) 789 break; 790 } 791 order[i] = j; 792 } 793 n = i; 794 pp = (u_char **)hp->h_addr_list; 795 for (i = 0; i < n - 1; i++) { 796 for (j = i + 1; j < n; j++) { 797 if (order[i] > order[j]) { 798 ap = pp[i]; 799 pp[i] = pp[j]; 800 pp[j] = ap; 801 t = order[i]; 802 order[i] = order[j]; 803 order[j] = t; 804 } 805 } 806 } 807 return hp; 808 } 809 810 static char * 811 _hgetword(char **pp) 812 { 813 char c, *p, *ret; 814 const char *sp; 815 static const char sep[] = "# \t\n"; 816 817 ret = NULL; 818 for (p = *pp; (c = *p) != '\0'; p++) { 819 for (sp = sep; *sp != '\0'; sp++) { 820 if (c == *sp) 821 break; 822 } 823 if (c == '#') 824 p[1] = '\0'; /* ignore rest of line */ 825 if (ret == NULL) { 826 if (*sp == '\0') 827 ret = p; 828 } else { 829 if (*sp != '\0') { 830 *p++ = '\0'; 831 break; 832 } 833 } 834 } 835 *pp = p; 836 if (ret == NULL || *ret == '\0') 837 return NULL; 838 return ret; 839 } 840 841 /* 842 * FILES (/etc/hosts) 843 */ 844 845 static FILE * 846 _files_open(int *errp) 847 { 848 FILE *fp; 849 fp = fopen(_PATH_HOSTS, "r"); 850 if (fp == NULL) 851 *errp = NO_RECOVERY; 852 return fp; 853 } 854 855 static struct hostent * 856 _files_ghbyname(const char *name, int af, int *errp) 857 { 858 int match, nalias; 859 char *p, *line, *addrstr, *cname; 860 FILE *fp; 861 struct hostent *rethp, *hp, hpbuf; 862 char *aliases[MAXALIASES + 1], *addrs[2]; 863 union inx_addr addrbuf; 864 char buf[BUFSIZ]; 865 int af0 = af; 866 867 if ((fp = _files_open(errp)) == NULL) 868 return NULL; 869 rethp = hp = NULL; 870 871 while (fgets(buf, sizeof(buf), fp)) { 872 line = buf; 873 if ((addrstr = _hgetword(&line)) == NULL 874 || (cname = _hgetword(&line)) == NULL) 875 continue; 876 match = (strcasecmp(cname, name) == 0); 877 nalias = 0; 878 while ((p = _hgetword(&line)) != NULL) { 879 if (!match) 880 match = (strcasecmp(p, name) == 0); 881 if (nalias < MAXALIASES) 882 aliases[nalias++] = p; 883 } 884 if (!match) 885 continue; 886 switch (af0) { 887 case AF_INET: 888 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 889 != 1) { 890 *errp = NO_DATA; /* name found */ 891 continue; 892 } 893 af = af0; 894 break; 895 #ifdef INET6 896 case AF_INET6: 897 if (inet_pton(af, addrstr, &addrbuf) != 1) { 898 *errp = NO_DATA; /* name found */ 899 continue; 900 } 901 af = af0; 902 break; 903 #endif 904 case AF_UNSPEC: 905 if (inet_aton(addrstr, (struct in_addr *)&addrbuf) 906 == 1) { 907 af = AF_INET; 908 break; 909 } 910 #ifdef INET6 911 if (inet_pton(AF_INET6, addrstr, &addrbuf) == 1) { 912 af = AF_INET6; 913 break; 914 } 915 #endif 916 *errp = NO_DATA; /* name found */ 917 continue; 918 /* NOTREACHED */ 919 } 920 hp = &hpbuf; 921 hp->h_name = cname; 922 hp->h_aliases = aliases; 923 aliases[nalias] = NULL; 924 hp->h_addrtype = af; 925 hp->h_length = ADDRLEN(af); 926 hp->h_addr_list = addrs; 927 addrs[0] = (char *)&addrbuf; 928 addrs[1] = NULL; 929 hp = _hpcopy(hp, errp); 930 rethp = _hpmerge(rethp, hp, errp); 931 } 932 fclose(fp); 933 return rethp; 934 } 935 936 static struct hostent * 937 _files_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 938 { 939 int nalias; 940 char *p, *line; 941 FILE *fp; 942 struct hostent *hp, hpbuf; 943 char *aliases[MAXALIASES + 1], *addrs[2]; 944 union inx_addr addrbuf; 945 char buf[BUFSIZ]; 946 947 if ((fp = _files_open(errp)) == NULL) 948 return NULL; 949 hp = NULL; 950 while (fgets(buf, sizeof(buf), fp)) { 951 line = buf; 952 if ((p = _hgetword(&line)) == NULL 953 || (af == AF_INET 954 ? inet_aton(p, (struct in_addr *)&addrbuf) 955 : inet_pton(af, p, &addrbuf)) != 1 956 || memcmp(addr, &addrbuf, addrlen) != 0 957 || (p = _hgetword(&line)) == NULL) 958 continue; 959 hp = &hpbuf; 960 hp->h_name = p; 961 hp->h_aliases = aliases; 962 nalias = 0; 963 while ((p = _hgetword(&line)) != NULL) { 964 if (nalias < MAXALIASES) 965 aliases[nalias++] = p; 966 } 967 aliases[nalias] = NULL; 968 hp->h_addrtype = af; 969 hp->h_length = addrlen; 970 hp->h_addr_list = addrs; 971 addrs[0] = (char *)&addrbuf; 972 addrs[1] = NULL; 973 hp = _hpcopy(hp, errp); 974 break; 975 } 976 fclose(fp); 977 return hp; 978 } 979 980 #ifdef YP 981 /* 982 * NIS 983 * 984 * XXX actually a hack, these are INET4 specific. 985 */ 986 static struct hostent * 987 _nis_ghbyname(const char *name, int af, int *errp) 988 { 989 struct hostent *hp = NULL; 990 991 if (af == AF_UNSPEC) 992 af = AF_INET; 993 if (af == AF_INET) { 994 hp = _gethostbynisname(name, af); 995 if (hp != NULL) 996 hp = _hpcopy(hp, errp); 997 } 998 return (hp); 999 1000 } 1001 1002 static struct hostent * 1003 _nis_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1004 { 1005 struct hostent *hp = NULL; 1006 1007 if (af == AF_INET) { 1008 hp = _gethostbynisaddr(addr, addrlen, af); 1009 if (hp != NULL) 1010 hp = _hpcopy(hp, errp); 1011 } 1012 return (hp); 1013 } 1014 #endif 1015 1016 struct __res_type_list { 1017 SLIST_ENTRY(__res_type_list) rtl_entry; 1018 int rtl_type; 1019 }; 1020 1021 #define MAXPACKET (64*1024) 1022 1023 typedef union { 1024 HEADER hdr; 1025 u_char buf[MAXPACKET]; 1026 } querybuf; 1027 1028 static struct hostent *getanswer __P((const querybuf *, int, const char *, 1029 int, struct hostent *, int *)); 1030 1031 /* 1032 * we don't need to take care about sorting, nor IPv4 mapped address here. 1033 */ 1034 static struct hostent * 1035 getanswer(answer, anslen, qname, qtype, template, errp) 1036 const querybuf *answer; 1037 int anslen; 1038 const char *qname; 1039 int qtype; 1040 struct hostent *template; 1041 int *errp; 1042 { 1043 register const HEADER *hp; 1044 register const u_char *cp; 1045 register int n; 1046 const u_char *eom, *erdata; 1047 char *bp, **ap, **hap, *obp; 1048 int type, class, buflen, ancount, qdcount; 1049 int haveanswer, had_error; 1050 char tbuf[MAXDNAME]; 1051 const char *tname; 1052 int (*name_ok) __P((const char *)); 1053 static char *h_addr_ptrs[MAXADDRS + 1]; 1054 static char *host_aliases[MAXALIASES]; 1055 static char hostbuf[8*1024]; 1056 1057 #define BOUNDED_INCR(x) \ 1058 do { \ 1059 cp += x; \ 1060 if (cp > eom) { \ 1061 *errp = NO_RECOVERY; \ 1062 return (NULL); \ 1063 } \ 1064 } while (0) 1065 1066 #define BOUNDS_CHECK(ptr, count) \ 1067 do { \ 1068 if ((ptr) + (count) > eom) { \ 1069 *errp = NO_RECOVERY; \ 1070 return (NULL); \ 1071 } \ 1072 } while (0) 1073 1074 /* XXX do {} while (0) cannot be put here */ 1075 #define DNS_ASSERT(x) \ 1076 { \ 1077 if (!(x)) { \ 1078 cp += n; \ 1079 continue; \ 1080 } \ 1081 } 1082 1083 /* XXX do {} while (0) cannot be put here */ 1084 #define DNS_FATAL(x) \ 1085 { \ 1086 if (!(x)) { \ 1087 had_error++; \ 1088 continue; \ 1089 } \ 1090 } 1091 1092 tname = qname; 1093 template->h_name = NULL; 1094 eom = answer->buf + anslen; 1095 switch (qtype) { 1096 case T_A: 1097 case T_AAAA: 1098 name_ok = res_hnok; 1099 break; 1100 case T_PTR: 1101 name_ok = res_dnok; 1102 break; 1103 default: 1104 return (NULL); /* XXX should be abort(); */ 1105 } 1106 /* 1107 * find first satisfactory answer 1108 */ 1109 hp = &answer->hdr; 1110 ancount = ntohs(hp->ancount); 1111 qdcount = ntohs(hp->qdcount); 1112 bp = hostbuf; 1113 buflen = sizeof hostbuf; 1114 cp = answer->buf; 1115 BOUNDED_INCR(HFIXEDSZ); 1116 if (qdcount != 1) { 1117 *errp = NO_RECOVERY; 1118 return (NULL); 1119 } 1120 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1121 if ((n < 0) || !(*name_ok)(bp)) { 1122 *errp = NO_RECOVERY; 1123 return (NULL); 1124 } 1125 BOUNDED_INCR(n + QFIXEDSZ); 1126 if (qtype == T_A || qtype == T_AAAA) { 1127 /* res_send() has already verified that the query name is the 1128 * same as the one we sent; this just gets the expanded name 1129 * (i.e., with the succeeding search-domain tacked on). 1130 */ 1131 n = strlen(bp) + 1; /* for the \0 */ 1132 if (n >= MAXHOSTNAMELEN) { 1133 *errp = NO_RECOVERY; 1134 return (NULL); 1135 } 1136 template->h_name = bp; 1137 bp += n; 1138 buflen -= n; 1139 /* The qname can be abbreviated, but h_name is now absolute. */ 1140 qname = template->h_name; 1141 } 1142 ap = host_aliases; 1143 *ap = NULL; 1144 template->h_aliases = host_aliases; 1145 hap = h_addr_ptrs; 1146 *hap = NULL; 1147 template->h_addr_list = h_addr_ptrs; 1148 haveanswer = 0; 1149 had_error = 0; 1150 while (ancount-- > 0 && cp < eom && !had_error) { 1151 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1152 DNS_FATAL(n >= 0); 1153 DNS_FATAL((*name_ok)(bp)); 1154 cp += n; /* name */ 1155 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); 1156 type = _getshort(cp); 1157 cp += INT16SZ; /* type */ 1158 class = _getshort(cp); 1159 cp += INT16SZ + INT32SZ; /* class, TTL */ 1160 n = _getshort(cp); 1161 cp += INT16SZ; /* len */ 1162 BOUNDS_CHECK(cp, n); 1163 erdata = cp + n; 1164 DNS_ASSERT(class == C_IN); 1165 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { 1166 if (ap >= &host_aliases[MAXALIASES-1]) 1167 continue; 1168 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1169 DNS_FATAL(n >= 0); 1170 DNS_FATAL((*name_ok)(tbuf)); 1171 cp += n; 1172 if (cp != erdata) { 1173 *errp = NO_RECOVERY; 1174 return (NULL); 1175 } 1176 /* Store alias. */ 1177 *ap++ = bp; 1178 n = strlen(bp) + 1; /* for the \0 */ 1179 DNS_FATAL(n < MAXHOSTNAMELEN); 1180 bp += n; 1181 buflen -= n; 1182 /* Get canonical name. */ 1183 n = strlen(tbuf) + 1; /* for the \0 */ 1184 DNS_FATAL(n <= buflen); 1185 DNS_FATAL(n < MAXHOSTNAMELEN); 1186 strcpy(bp, tbuf); 1187 template->h_name = bp; 1188 bp += n; 1189 buflen -= n; 1190 continue; 1191 } 1192 if (qtype == T_PTR && type == T_CNAME) { 1193 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1194 if (n < 0 || !res_dnok(tbuf)) { 1195 had_error++; 1196 continue; 1197 } 1198 cp += n; 1199 if (cp != erdata) { 1200 *errp = NO_RECOVERY; 1201 return (NULL); 1202 } 1203 /* Get canonical name. */ 1204 n = strlen(tbuf) + 1; /* for the \0 */ 1205 if (n > buflen || n >= MAXHOSTNAMELEN) { 1206 had_error++; 1207 continue; 1208 } 1209 strcpy(bp, tbuf); 1210 tname = bp; 1211 bp += n; 1212 buflen -= n; 1213 continue; 1214 } 1215 DNS_ASSERT(type == qtype); 1216 switch (type) { 1217 case T_PTR: 1218 DNS_ASSERT(strcasecmp(tname, bp) == 0); 1219 n = dn_expand(answer->buf, eom, cp, bp, buflen); 1220 DNS_FATAL(n >= 0); 1221 DNS_FATAL(res_hnok(bp)); 1222 #if MULTI_PTRS_ARE_ALIASES 1223 cp += n; 1224 if (cp != erdata) { 1225 *errp = NO_RECOVERY; 1226 return (NULL); 1227 } 1228 if (!haveanswer) 1229 template->h_name = bp; 1230 else if (ap < &host_aliases[MAXALIASES-1]) 1231 *ap++ = bp; 1232 else 1233 n = -1; 1234 if (n != -1) { 1235 n = strlen(bp) + 1; /* for the \0 */ 1236 if (n >= MAXHOSTNAMELEN) { 1237 had_error++; 1238 break; 1239 } 1240 bp += n; 1241 buflen -= n; 1242 } 1243 break; 1244 #else 1245 template->h_name = bp; 1246 *errp = NETDB_SUCCESS; 1247 return (template); 1248 #endif 1249 case T_A: 1250 case T_AAAA: 1251 DNS_ASSERT(strcasecmp(template->h_name, bp) == 0); 1252 DNS_ASSERT(n == template->h_length); 1253 if (!haveanswer) { 1254 register int nn; 1255 1256 template->h_name = bp; 1257 nn = strlen(bp) + 1; /* for the \0 */ 1258 bp += nn; 1259 buflen -= nn; 1260 } 1261 obp = bp; /* ALIGN rounds up */ 1262 bp = (char *)ALIGN(bp); 1263 buflen -= (bp - obp); 1264 1265 DNS_FATAL(bp + n < &hostbuf[sizeof hostbuf]); 1266 DNS_ASSERT(hap < &h_addr_ptrs[MAXADDRS-1]); 1267 #ifdef FILTER_V4MAPPED 1268 if (type == T_AAAA) { 1269 struct in6_addr in6; 1270 memcpy(&in6, cp, sizeof(in6)); 1271 DNS_ASSERT(IN6_IS_ADDR_V4MAPPED(&in6) == 0); 1272 } 1273 #endif 1274 bcopy(cp, *hap++ = bp, n); 1275 bp += n; 1276 buflen -= n; 1277 cp += n; 1278 if (cp != erdata) { 1279 *errp = NO_RECOVERY; 1280 return (NULL); 1281 } 1282 break; 1283 default: 1284 abort(); 1285 } 1286 if (!had_error) 1287 haveanswer++; 1288 } 1289 if (haveanswer) { 1290 *ap = NULL; 1291 *hap = NULL; 1292 if (!template->h_name) { 1293 n = strlen(qname) + 1; /* for the \0 */ 1294 if (n > buflen || n >= MAXHOSTNAMELEN) 1295 goto no_recovery; 1296 strcpy(bp, qname); 1297 template->h_name = bp; 1298 bp += n; 1299 buflen -= n; 1300 } 1301 *errp = NETDB_SUCCESS; 1302 return (template); 1303 } 1304 no_recovery: 1305 *errp = NO_RECOVERY; 1306 return (NULL); 1307 1308 #undef BOUNDED_INCR 1309 #undef BOUNDS_CHECK 1310 #undef DNS_ASSERT 1311 #undef DNS_FATAL 1312 } 1313 1314 /* res_search() variant with multiple query support. */ 1315 static struct hostent * 1316 _res_search_multi(name, rtl, errp) 1317 const char *name; /* domain name */ 1318 struct __res_type_list *rtl; /* list of query types */ 1319 int *errp; 1320 { 1321 const char *cp, * const *domain; 1322 struct hostent *hp0 = NULL, *hp; 1323 struct hostent hpbuf; 1324 u_int dots; 1325 int trailing_dot, ret, saved_herrno; 1326 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 1327 struct __res_type_list *rtl0 = rtl; 1328 querybuf *buf; 1329 1330 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 1331 *errp = NETDB_INTERNAL; 1332 return (NULL); 1333 } 1334 dots = 0; 1335 for (cp = name; *cp; cp++) 1336 dots += (*cp == '.'); 1337 trailing_dot = 0; 1338 if (cp > name && *--cp == '.') 1339 trailing_dot++; 1340 1341 buf = malloc(sizeof(*buf)); 1342 if (buf == NULL) { 1343 *errp = NETDB_INTERNAL; 1344 return NULL; 1345 } 1346 1347 /* If there aren't any dots, it could be a user-level alias */ 1348 if (!dots && (cp = hostalias(name)) != NULL) { 1349 for(rtl = rtl0; rtl != NULL; 1350 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1351 ret = res_query(cp, C_IN, rtl->rtl_type, buf->buf, 1352 sizeof(buf->buf)); 1353 if (ret > 0 && ret < sizeof(buf->buf)) { 1354 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1355 ? AF_INET6 : AF_INET; 1356 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1357 hp = getanswer(buf, ret, name, rtl->rtl_type, 1358 &hpbuf, errp); 1359 if (!hp) 1360 continue; 1361 hp = _hpcopy(&hpbuf, errp); 1362 hp0 = _hpmerge(hp0, hp, errp); 1363 } 1364 } 1365 free(buf); 1366 return (hp0); 1367 } 1368 1369 /* 1370 * If there are dots in the name already, let's just give it a try 1371 * 'as is'. The threshold can be set with the "ndots" option. 1372 */ 1373 saved_herrno = -1; 1374 if (dots >= _res.ndots) { 1375 for(rtl = rtl0; rtl != NULL; 1376 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1377 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1378 buf->buf, sizeof(buf->buf)); 1379 if (ret > 0 && ret < sizeof(buf->buf)) { 1380 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1381 ? AF_INET6 : AF_INET; 1382 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1383 hp = getanswer(buf, ret, name, rtl->rtl_type, 1384 &hpbuf, errp); 1385 if (!hp) 1386 continue; 1387 hp = _hpcopy(&hpbuf, errp); 1388 hp0 = _hpmerge(hp0, hp, errp); 1389 } 1390 } 1391 if (hp0 != NULL) { 1392 free(buf); 1393 return (hp0); 1394 } 1395 saved_herrno = *errp; 1396 tried_as_is++; 1397 } 1398 1399 /* 1400 * We do at least one level of search if 1401 * - there is no dot and RES_DEFNAME is set, or 1402 * - there is at least one dot, there is no trailing dot, 1403 * and RES_DNSRCH is set. 1404 */ 1405 if ((!dots && (_res.options & RES_DEFNAMES)) || 1406 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { 1407 int done = 0; 1408 1409 for (domain = (const char * const *)_res.dnsrch; 1410 *domain && !done; 1411 domain++) { 1412 1413 for(rtl = rtl0; rtl != NULL; 1414 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1415 ret = res_querydomain(name, *domain, C_IN, 1416 rtl->rtl_type, 1417 buf->buf, sizeof(buf->buf)); 1418 if (ret > 0 && ret < sizeof(buf->buf)) { 1419 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1420 ? AF_INET6 : AF_INET; 1421 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1422 hp = getanswer(buf, ret, name, 1423 rtl->rtl_type, &hpbuf, errp); 1424 if (!hp) 1425 continue; 1426 hp = _hpcopy(&hpbuf, errp); 1427 hp0 = _hpmerge(hp0, hp, errp); 1428 } 1429 } 1430 if (hp0 != NULL) { 1431 free(buf); 1432 return (hp0); 1433 } 1434 1435 /* 1436 * If no server present, give up. 1437 * If name isn't found in this domain, 1438 * keep trying higher domains in the search list 1439 * (if that's enabled). 1440 * On a NO_DATA error, keep trying, otherwise 1441 * a wildcard entry of another type could keep us 1442 * from finding this entry higher in the domain. 1443 * If we get some other error (negative answer or 1444 * server failure), then stop searching up, 1445 * but try the input name below in case it's 1446 * fully-qualified. 1447 */ 1448 if (errno == ECONNREFUSED) { 1449 free(buf); 1450 *errp = TRY_AGAIN; 1451 return (NULL); 1452 } 1453 1454 switch (*errp) { 1455 case NO_DATA: 1456 got_nodata++; 1457 /* FALLTHROUGH */ 1458 case HOST_NOT_FOUND: 1459 /* keep trying */ 1460 break; 1461 case TRY_AGAIN: 1462 if (buf->hdr.rcode == SERVFAIL) { 1463 /* try next search element, if any */ 1464 got_servfail++; 1465 break; 1466 } 1467 /* FALLTHROUGH */ 1468 default: 1469 /* anything else implies that we're done */ 1470 done++; 1471 } 1472 1473 /* if we got here for some reason other than DNSRCH, 1474 * we only wanted one iteration of the loop, so stop. 1475 */ 1476 if (!(_res.options & RES_DNSRCH)) 1477 done++; 1478 } 1479 } 1480 1481 /* 1482 * If we have not already tried the name "as is", do that now. 1483 * note that we do this regardless of how many dots were in the 1484 * name or whether it ends with a dot unless NOTLDQUERY is set. 1485 */ 1486 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { 1487 for(rtl = rtl0; rtl != NULL; 1488 rtl = SLIST_NEXT(rtl, rtl_entry)) { 1489 ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type, 1490 buf->buf, sizeof(buf->buf)); 1491 if (ret > 0 && ret < sizeof(buf->buf)) { 1492 hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA) 1493 ? AF_INET6 : AF_INET; 1494 hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype); 1495 hp = getanswer(buf, ret, name, rtl->rtl_type, 1496 &hpbuf, errp); 1497 if (!hp) 1498 continue; 1499 hp = _hpcopy(&hpbuf, errp); 1500 hp0 = _hpmerge(hp0, hp, errp); 1501 } 1502 } 1503 if (hp0 != NULL) { 1504 free(buf); 1505 return (hp0); 1506 } 1507 } 1508 1509 free(buf); 1510 1511 /* if we got here, we didn't satisfy the search. 1512 * if we did an initial full query, return that query's h_errno 1513 * (note that we wouldn't be here if that query had succeeded). 1514 * else if we ever got a nodata, send that back as the reason. 1515 * else send back meaningless h_errno, that being the one from 1516 * the last DNSRCH we did. 1517 */ 1518 if (saved_herrno != -1) 1519 *errp = saved_herrno; 1520 else if (got_nodata) 1521 *errp = NO_DATA; 1522 else if (got_servfail) 1523 *errp = TRY_AGAIN; 1524 return (NULL); 1525 } 1526 1527 static struct hostent * 1528 _dns_ghbyname(const char *name, int af, int *errp) 1529 { 1530 struct __res_type_list *rtl, rtl4; 1531 #ifdef INET6 1532 struct __res_type_list rtl6; 1533 #endif 1534 1535 #ifdef INET6 1536 switch (af) { 1537 case AF_UNSPEC: 1538 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1539 SLIST_NEXT(&rtl6, rtl_entry) = &rtl4; rtl6.rtl_type = T_AAAA; 1540 rtl = &rtl6; 1541 break; 1542 case AF_INET6: 1543 SLIST_NEXT(&rtl6, rtl_entry) = NULL; rtl6.rtl_type = T_AAAA; 1544 rtl = &rtl6; 1545 break; 1546 case AF_INET: 1547 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1548 rtl = &rtl4; 1549 break; 1550 } 1551 #else 1552 SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A; 1553 rtl = &rtl4; 1554 #endif 1555 return(_res_search_multi(name, rtl, errp)); 1556 } 1557 1558 static struct hostent * 1559 _dns_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1560 { 1561 int n; 1562 struct hostent *hp; 1563 u_char c, *cp; 1564 char *bp; 1565 struct hostent hbuf; 1566 int na; 1567 #ifdef INET6 1568 static const char hex[] = "0123456789abcdef"; 1569 #endif 1570 querybuf *buf; 1571 char qbuf[MAXDNAME+1]; 1572 char *hlist[2]; 1573 char *tld6[] = { "ip6.arpa", "ip6.int", NULL }; 1574 char *tld4[] = { "in-addr.arpa", NULL }; 1575 char **tld; 1576 1577 #ifdef INET6 1578 /* XXX */ 1579 if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr)) 1580 return NULL; 1581 #endif 1582 1583 switch (af) { 1584 #ifdef INET6 1585 case AF_INET6: 1586 tld = tld6; 1587 break; 1588 #endif 1589 case AF_INET: 1590 tld = tld4; 1591 break; 1592 default: 1593 return NULL; 1594 } 1595 1596 if ((_res.options & RES_INIT) == 0) { 1597 if (res_init() < 0) { 1598 *errp = h_errno; 1599 return NULL; 1600 } 1601 } 1602 memset(&hbuf, 0, sizeof(hbuf)); 1603 hbuf.h_name = NULL; 1604 hbuf.h_addrtype = af; 1605 hbuf.h_length = addrlen; 1606 na = 0; 1607 1608 buf = malloc(sizeof(*buf)); 1609 if (buf == NULL) { 1610 *errp = NETDB_INTERNAL; 1611 return NULL; 1612 } 1613 for (/* nothing */; *tld; tld++) { 1614 /* 1615 * XXX assumes that MAXDNAME is big enough - error checks 1616 * has been made by callers 1617 */ 1618 n = 0; 1619 bp = qbuf; 1620 cp = (u_char *)addr+addrlen-1; 1621 switch (af) { 1622 #ifdef INET6 1623 case AF_INET6: 1624 for (; n < addrlen; n++, cp--) { 1625 c = *cp; 1626 *bp++ = hex[c & 0xf]; 1627 *bp++ = '.'; 1628 *bp++ = hex[c >> 4]; 1629 *bp++ = '.'; 1630 } 1631 strcpy(bp, *tld); 1632 break; 1633 #endif 1634 case AF_INET: 1635 for (; n < addrlen; n++, cp--) { 1636 c = *cp; 1637 if (c >= 100) 1638 *bp++ = '0' + c / 100; 1639 if (c >= 10) 1640 *bp++ = '0' + (c % 100) / 10; 1641 *bp++ = '0' + c % 10; 1642 *bp++ = '.'; 1643 } 1644 strcpy(bp, *tld); 1645 break; 1646 } 1647 1648 n = res_query(qbuf, C_IN, T_PTR, buf->buf, sizeof buf->buf); 1649 if (n < 0) { 1650 *errp = h_errno; 1651 continue; 1652 } else if (n > sizeof(buf->buf)) { 1653 *errp = NETDB_INTERNAL; 1654 #if 0 1655 errno = ERANGE; /* XXX is it OK to set errno here? */ 1656 #endif 1657 continue; 1658 } 1659 hp = getanswer(buf, n, qbuf, T_PTR, &hbuf, errp); 1660 if (!hp) 1661 continue; 1662 free(buf); 1663 hbuf.h_addrtype = af; 1664 hbuf.h_length = addrlen; 1665 hbuf.h_addr_list = hlist; 1666 hlist[0] = (char *)addr; 1667 hlist[1] = NULL; 1668 return _hpcopy(&hbuf, errp); 1669 } 1670 free(buf); 1671 return NULL; 1672 } 1673 1674 static void 1675 _dns_shent(int stayopen) 1676 { 1677 if ((_res.options & RES_INIT) == 0) { 1678 if (res_init() < 0) 1679 return; 1680 } 1681 if (stayopen) 1682 _res.options |= RES_STAYOPEN | RES_USEVC; 1683 } 1684 1685 static void 1686 _dns_ehent(void) 1687 { 1688 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 1689 res_close(); 1690 } 1691 1692 #ifdef ICMPNL 1693 1694 /* 1695 * experimental: 1696 * draft-ietf-ipngwg-icmp-namelookups-02.txt 1697 * ifindex is assumed to be encoded in addr. 1698 */ 1699 #include <sys/uio.h> 1700 #include <netinet/ip6.h> 1701 #include <netinet/icmp6.h> 1702 1703 struct _icmp_host_cache { 1704 struct _icmp_host_cache *hc_next; 1705 int hc_ifindex; 1706 struct in6_addr hc_addr; 1707 char *hc_name; 1708 }; 1709 1710 static char * 1711 _icmp_fqdn_query(const struct in6_addr *addr, int ifindex) 1712 { 1713 int s; 1714 struct icmp6_filter filter; 1715 struct msghdr msg; 1716 struct cmsghdr *cmsg; 1717 struct in6_pktinfo *pkt; 1718 char cbuf[256]; 1719 char buf[1024]; 1720 int cc; 1721 struct icmp6_fqdn_query *fq; 1722 struct icmp6_fqdn_reply *fr; 1723 struct _icmp_host_cache *hc; 1724 struct sockaddr_in6 sin6; 1725 struct iovec iov; 1726 fd_set s_fds, fds; 1727 struct timeval tout; 1728 int len; 1729 char *name; 1730 static int pid; 1731 static struct _icmp_host_cache *hc_head; 1732 1733 for (hc = hc_head; hc; hc = hc->hc_next) { 1734 if (hc->hc_ifindex == ifindex 1735 && IN6_ARE_ADDR_EQUAL(&hc->hc_addr, addr)) 1736 return hc->hc_name; 1737 } 1738 1739 if (pid == 0) 1740 pid = getpid(); 1741 1742 ICMP6_FILTER_SETBLOCKALL(&filter); 1743 ICMP6_FILTER_SETPASS(ICMP6_FQDN_REPLY, &filter); 1744 1745 FD_ZERO(&s_fds); 1746 tout.tv_sec = 0; 1747 tout.tv_usec = 200000; /*XXX: 200ms*/ 1748 1749 fq = (struct icmp6_fqdn_query *)buf; 1750 fq->icmp6_fqdn_type = ICMP6_FQDN_QUERY; 1751 fq->icmp6_fqdn_code = 0; 1752 fq->icmp6_fqdn_cksum = 0; 1753 fq->icmp6_fqdn_id = (u_short)pid; 1754 fq->icmp6_fqdn_unused = 0; 1755 fq->icmp6_fqdn_cookie[0] = 0; 1756 fq->icmp6_fqdn_cookie[1] = 0; 1757 1758 memset(&sin6, 0, sizeof(sin6)); 1759 sin6.sin6_family = AF_INET6; 1760 sin6.sin6_addr = *addr; 1761 1762 memset(&msg, 0, sizeof(msg)); 1763 msg.msg_name = (caddr_t)&sin6; 1764 msg.msg_namelen = sizeof(sin6); 1765 msg.msg_iov = &iov; 1766 msg.msg_iovlen = 1; 1767 msg.msg_control = NULL; 1768 msg.msg_controllen = 0; 1769 iov.iov_base = (caddr_t)buf; 1770 iov.iov_len = sizeof(struct icmp6_fqdn_query); 1771 1772 if (ifindex) { 1773 msg.msg_control = cbuf; 1774 msg.msg_controllen = sizeof(cbuf); 1775 cmsg = CMSG_FIRSTHDR(&msg); 1776 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 1777 cmsg->cmsg_level = IPPROTO_IPV6; 1778 cmsg->cmsg_type = IPV6_PKTINFO; 1779 pkt = (struct in6_pktinfo *)&cmsg[1]; 1780 memset(&pkt->ipi6_addr, 0, sizeof(struct in6_addr)); 1781 pkt->ipi6_ifindex = ifindex; 1782 cmsg = CMSG_NXTHDR(&msg, cmsg); 1783 msg.msg_controllen = (char *)cmsg - cbuf; 1784 } 1785 1786 if ((s = socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) 1787 return NULL; 1788 (void)setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, 1789 (char *)&filter, sizeof(filter)); 1790 cc = sendmsg(s, &msg, 0); 1791 if (cc < 0) { 1792 _close(s); 1793 return NULL; 1794 } 1795 FD_SET(s, &s_fds); 1796 for (;;) { 1797 fds = s_fds; 1798 if (select(s + 1, &fds, NULL, NULL, &tout) <= 0) { 1799 _close(s); 1800 return NULL; 1801 } 1802 len = sizeof(sin6); 1803 cc = recvfrom(s, buf, sizeof(buf), 0, 1804 (struct sockaddr *)&sin6, &len); 1805 if (cc <= 0) { 1806 _close(s); 1807 return NULL; 1808 } 1809 if (cc < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) 1810 continue; 1811 if (!IN6_ARE_ADDR_EQUAL(addr, &sin6.sin6_addr)) 1812 continue; 1813 fr = (struct icmp6_fqdn_reply *)(buf + sizeof(struct ip6_hdr)); 1814 if (fr->icmp6_fqdn_type == ICMP6_FQDN_REPLY) 1815 break; 1816 } 1817 _close(s); 1818 if (fr->icmp6_fqdn_cookie[1] != 0) { 1819 /* rfc1788 type */ 1820 name = buf + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 4; 1821 len = (buf + cc) - name; 1822 } else { 1823 len = fr->icmp6_fqdn_namelen; 1824 name = fr->icmp6_fqdn_name; 1825 } 1826 if (len <= 0) 1827 return NULL; 1828 name[len] = 0; 1829 1830 if ((hc = (struct _icmp_host_cache *)malloc(sizeof(*hc))) == NULL) 1831 return NULL; 1832 /* XXX: limit number of cached entries */ 1833 hc->hc_ifindex = ifindex; 1834 hc->hc_addr = *addr; 1835 hc->hc_name = strdup(name); 1836 hc->hc_next = hc_head; 1837 hc_head = hc; 1838 return hc->hc_name; 1839 } 1840 1841 static struct hostent * 1842 _icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp) 1843 { 1844 char *hname; 1845 int ifindex; 1846 struct in6_addr addr6; 1847 1848 if (af != AF_INET6) { 1849 /* 1850 * Note: rfc1788 defines Who Are You for IPv4, 1851 * but no one implements it. 1852 */ 1853 return NULL; 1854 } 1855 1856 memcpy(&addr6, addr, addrlen); 1857 ifindex = (addr6.s6_addr[2] << 8) | addr6.s6_addr[3]; 1858 addr6.s6_addr[2] = addr6.s6_addr[3] = 0; 1859 1860 if (!IN6_IS_ADDR_LINKLOCAL(&addr6)) 1861 return NULL; /*XXX*/ 1862 1863 if ((hname = _icmp_fqdn_query(&addr6, ifindex)) == NULL) 1864 return NULL; 1865 return _hpaddr(af, hname, &addr6, errp); 1866 } 1867 #endif /* ICMPNL */ 1868