1 /* $NetBSD: getaddrinfo.c,v 1.82 2006/03/25 12:09:40 rpaulo Exp $ */ 2 /* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 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 /* 34 * Issues to be discussed: 35 * - Thread safe-ness must be checked. 36 * - Return values. There are nonstandard return values defined and used 37 * in the source code. This is because RFC2553 is silent about which error 38 * code must be returned for which situation. 39 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2 40 * says to use inet_aton() to convert IPv4 numeric to binary (alows 41 * classful form as a result). 42 * current code - disallow classful form for IPv4 (due to use of inet_pton). 43 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is 44 * invalid. 45 * current code - SEGV on freeaddrinfo(NULL) 46 * Note: 47 * - We use getipnodebyname() just for thread-safeness. There's no intent 48 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to 49 * getipnodebyname(). 50 * - The code filters out AFs that are not supported by the kernel, 51 * when globbing NULL hostname (to loopback, or wildcard). Is it the right 52 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG 53 * in ai_flags? 54 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. 55 * (1) what should we do against numeric hostname (2) what should we do 56 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? 57 * non-loopback address configured? global address configured? 58 * - To avoid search order issue, we have a big amount of code duplicate 59 * from gethnamaddr.c and some other places. The issues that there's no 60 * lower layer function to lookup "IPv4 or IPv6" record. Calling 61 * gethostbyname2 from getaddrinfo will end up in wrong search order, as 62 * follows: 63 * - The code makes use of following calls when asked to resolver with 64 * ai_family = PF_UNSPEC: 65 * getipnodebyname(host, AF_INET6); 66 * getipnodebyname(host, AF_INET); 67 * This will result in the following queries if the node is configure to 68 * prefer /etc/hosts than DNS: 69 * lookup /etc/hosts for IPv6 address 70 * lookup DNS for IPv6 address 71 * lookup /etc/hosts for IPv4 address 72 * lookup DNS for IPv4 address 73 * which may not meet people's requirement. 74 * The right thing to happen is to have underlying layer which does 75 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos. 76 * This would result in a bit of code duplicate with _dns_ghbyname() and 77 * friends. 78 */ 79 80 #include <fcntl.h> 81 #include <sys/cdefs.h> 82 #include <sys/types.h> 83 #include <sys/stat.h> 84 #include <sys/param.h> 85 #include <sys/socket.h> 86 #include <sys/un.h> 87 #include <net/if.h> 88 #include <netinet/in.h> 89 #include <arpa/inet.h> 90 #include <arpa/nameser.h> 91 #include <assert.h> 92 #include <ctype.h> 93 #include <errno.h> 94 #include <netdb.h> 95 #include "NetdClientDispatch.h" 96 #include "resolv_cache.h" 97 #include "resolv_netid.h" 98 #include "resolv_private.h" 99 #include <stdbool.h> 100 #include <stddef.h> 101 #include <stdio.h> 102 #include <stdlib.h> 103 #include <string.h> 104 #include <strings.h> 105 #include <unistd.h> 106 107 #include <syslog.h> 108 #include <stdarg.h> 109 #include "nsswitch.h" 110 111 #ifdef ANDROID_CHANGES 112 #include <sys/system_properties.h> 113 #endif /* ANDROID_CHANGES */ 114 115 typedef union sockaddr_union { 116 struct sockaddr generic; 117 struct sockaddr_in in; 118 struct sockaddr_in6 in6; 119 } sockaddr_union; 120 121 #define SUCCESS 0 122 #define ANY 0 123 #define YES 1 124 #define NO 0 125 126 static const char in_addrany[] = { 0, 0, 0, 0 }; 127 static const char in_loopback[] = { 127, 0, 0, 1 }; 128 #ifdef INET6 129 static const char in6_addrany[] = { 130 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 131 }; 132 static const char in6_loopback[] = { 133 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 134 }; 135 #endif 136 137 // This should be synchronized to ResponseCode.h 138 static const int DnsProxyQueryResult = 222; 139 140 static const struct afd { 141 int a_af; 142 int a_addrlen; 143 int a_socklen; 144 int a_off; 145 const char *a_addrany; 146 const char *a_loopback; 147 int a_scoped; 148 } afdl [] = { 149 #ifdef INET6 150 {PF_INET6, sizeof(struct in6_addr), 151 sizeof(struct sockaddr_in6), 152 offsetof(struct sockaddr_in6, sin6_addr), 153 in6_addrany, in6_loopback, 1}, 154 #endif 155 {PF_INET, sizeof(struct in_addr), 156 sizeof(struct sockaddr_in), 157 offsetof(struct sockaddr_in, sin_addr), 158 in_addrany, in_loopback, 0}, 159 {0, 0, 0, 0, NULL, NULL, 0}, 160 }; 161 162 struct explore { 163 int e_af; 164 int e_socktype; 165 int e_protocol; 166 const char *e_protostr; 167 int e_wild; 168 #define WILD_AF(ex) ((ex)->e_wild & 0x01) 169 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) 170 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) 171 }; 172 173 static const struct explore explore[] = { 174 #if 0 175 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, 176 #endif 177 #ifdef INET6 178 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 179 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 180 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, 181 #endif 182 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 183 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 184 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, 185 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, 186 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, 187 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, 188 { -1, 0, 0, NULL, 0 }, 189 }; 190 191 #ifdef INET6 192 #define PTON_MAX 16 193 #else 194 #define PTON_MAX 4 195 #endif 196 197 static const ns_src default_dns_files[] = { 198 { NSSRC_FILES, NS_SUCCESS }, 199 { NSSRC_DNS, NS_SUCCESS }, 200 { 0, 0 } 201 }; 202 203 #define MAXPACKET (64*1024) 204 205 typedef union { 206 HEADER hdr; 207 u_char buf[MAXPACKET]; 208 } querybuf; 209 210 struct res_target { 211 struct res_target *next; 212 const char *name; /* domain name */ 213 int qclass, qtype; /* class and type of query */ 214 u_char *answer; /* buffer to put answer */ 215 int anslen; /* size of answer buffer */ 216 int n; /* result length */ 217 }; 218 219 static int str2number(const char *); 220 static int explore_fqdn(const struct addrinfo *, const char *, 221 const char *, struct addrinfo **, const struct android_net_context *); 222 static int explore_null(const struct addrinfo *, 223 const char *, struct addrinfo **); 224 static int explore_numeric(const struct addrinfo *, const char *, 225 const char *, struct addrinfo **, const char *); 226 static int explore_numeric_scope(const struct addrinfo *, const char *, 227 const char *, struct addrinfo **); 228 static int get_canonname(const struct addrinfo *, 229 struct addrinfo *, const char *); 230 static struct addrinfo *get_ai(const struct addrinfo *, 231 const struct afd *, const char *); 232 static int get_portmatch(const struct addrinfo *, const char *); 233 static int get_port(const struct addrinfo *, const char *, int); 234 static const struct afd *find_afd(int); 235 #ifdef INET6 236 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); 237 #endif 238 239 static struct addrinfo *getanswer(const querybuf *, int, const char *, int, 240 const struct addrinfo *); 241 static int _dns_getaddrinfo(void *, void *, va_list); 242 static void _sethtent(FILE **); 243 static void _endhtent(FILE **); 244 static struct addrinfo *_gethtent(FILE **, const char *, 245 const struct addrinfo *); 246 static int _files_getaddrinfo(void *, void *, va_list); 247 static int _find_src_addr(const struct sockaddr *, struct sockaddr *, unsigned , uid_t); 248 249 static int res_queryN(const char *, struct res_target *, res_state); 250 static int res_searchN(const char *, struct res_target *, res_state); 251 static int res_querydomainN(const char *, const char *, 252 struct res_target *, res_state); 253 254 static const char * const ai_errlist[] = { 255 "Success", 256 "Address family for hostname not supported", /* EAI_ADDRFAMILY */ 257 "Temporary failure in name resolution", /* EAI_AGAIN */ 258 "Invalid value for ai_flags", /* EAI_BADFLAGS */ 259 "Non-recoverable failure in name resolution", /* EAI_FAIL */ 260 "ai_family not supported", /* EAI_FAMILY */ 261 "Memory allocation failure", /* EAI_MEMORY */ 262 "No address associated with hostname", /* EAI_NODATA */ 263 "hostname nor servname provided, or not known", /* EAI_NONAME */ 264 "servname not supported for ai_socktype", /* EAI_SERVICE */ 265 "ai_socktype not supported", /* EAI_SOCKTYPE */ 266 "System error returned in errno", /* EAI_SYSTEM */ 267 "Invalid value for hints", /* EAI_BADHINTS */ 268 "Resolved protocol is unknown", /* EAI_PROTOCOL */ 269 "Argument buffer overflow", /* EAI_OVERFLOW */ 270 "Unknown error", /* EAI_MAX */ 271 }; 272 273 /* XXX macros that make external reference is BAD. */ 274 275 #define GET_AI(ai, afd, addr) \ 276 do { \ 277 /* external reference: pai, error, and label free */ \ 278 (ai) = get_ai(pai, (afd), (addr)); \ 279 if ((ai) == NULL) { \ 280 error = EAI_MEMORY; \ 281 goto free; \ 282 } \ 283 } while (/*CONSTCOND*/0) 284 285 #define GET_PORT(ai, serv) \ 286 do { \ 287 /* external reference: error and label free */ \ 288 error = get_port((ai), (serv), 0); \ 289 if (error != 0) \ 290 goto free; \ 291 } while (/*CONSTCOND*/0) 292 293 #define GET_CANONNAME(ai, str) \ 294 do { \ 295 /* external reference: pai, error and label free */ \ 296 error = get_canonname(pai, (ai), (str)); \ 297 if (error != 0) \ 298 goto free; \ 299 } while (/*CONSTCOND*/0) 300 301 #define ERR(err) \ 302 do { \ 303 /* external reference: error, and label bad */ \ 304 error = (err); \ 305 goto bad; \ 306 /*NOTREACHED*/ \ 307 } while (/*CONSTCOND*/0) 308 309 #define MATCH_FAMILY(x, y, w) \ 310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \ 311 (y) == PF_UNSPEC))) 312 #define MATCH(x, y, w) \ 313 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) 314 315 const char * 316 gai_strerror(int ecode) 317 { 318 if (ecode < 0 || ecode > EAI_MAX) 319 ecode = EAI_MAX; 320 return ai_errlist[ecode]; 321 } 322 323 void 324 freeaddrinfo(struct addrinfo *ai) 325 { 326 struct addrinfo *next; 327 328 #if __ANDROID__ 329 if (ai == NULL) return; 330 #else 331 _DIAGASSERT(ai != NULL); 332 #endif 333 334 do { 335 next = ai->ai_next; 336 if (ai->ai_canonname) 337 free(ai->ai_canonname); 338 /* no need to free(ai->ai_addr) */ 339 free(ai); 340 ai = next; 341 } while (ai); 342 } 343 344 static int 345 str2number(const char *p) 346 { 347 char *ep; 348 unsigned long v; 349 350 assert(p != NULL); 351 352 if (*p == '\0') 353 return -1; 354 ep = NULL; 355 errno = 0; 356 v = strtoul(p, &ep, 10); 357 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) 358 return v; 359 else 360 return -1; 361 } 362 363 /* 364 * The following functions determine whether IPv4 or IPv6 connectivity is 365 * available in order to implement AI_ADDRCONFIG. 366 * 367 * Strictly speaking, AI_ADDRCONFIG should not look at whether connectivity is 368 * available, but whether addresses of the specified family are "configured 369 * on the local system". However, bionic doesn't currently support getifaddrs, 370 * so checking for connectivity is the next best thing. 371 */ 372 static int 373 _have_ipv6(unsigned mark, uid_t uid) { 374 static const struct sockaddr_in6 sin6_test = { 375 .sin6_family = AF_INET6, 376 .sin6_addr.s6_addr = { // 2000:: 377 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} 378 }; 379 sockaddr_union addr = { .in6 = sin6_test }; 380 return _find_src_addr(&addr.generic, NULL, mark, uid) == 1; 381 } 382 383 static int 384 _have_ipv4(unsigned mark, uid_t uid) { 385 static const struct sockaddr_in sin_test = { 386 .sin_family = AF_INET, 387 .sin_addr.s_addr = __constant_htonl(0x08080808L) // 8.8.8.8 388 }; 389 sockaddr_union addr = { .in = sin_test }; 390 return _find_src_addr(&addr.generic, NULL, mark, uid) == 1; 391 } 392 393 bool readBE32(FILE* fp, int32_t* result) { 394 int32_t tmp; 395 if (fread(&tmp, sizeof(tmp), 1, fp) != 1) { 396 return false; 397 } 398 *result = ntohl(tmp); 399 return true; 400 } 401 402 // Returns 0 on success, else returns on error. 403 static int 404 android_getaddrinfo_proxy( 405 const char *hostname, const char *servname, 406 const struct addrinfo *hints, struct addrinfo **res, unsigned netid) 407 { 408 int success = 0; 409 410 // Clear this at start, as we use its non-NULLness later (in the 411 // error path) to decide if we have to free up any memory we 412 // allocated in the process (before failing). 413 *res = NULL; 414 415 // Bogus things we can't serialize. Don't use the proxy. These will fail - let them. 416 if ((hostname != NULL && 417 strcspn(hostname, " \n\r\t^'\"") != strlen(hostname)) || 418 (servname != NULL && 419 strcspn(servname, " \n\r\t^'\"") != strlen(servname))) { 420 return EAI_NODATA; 421 } 422 423 FILE* proxy = android_open_proxy(); 424 if (proxy == NULL) { 425 return EAI_SYSTEM; 426 } 427 428 netid = __netdClientDispatch.netIdForResolv(netid); 429 430 // Send the request. 431 if (fprintf(proxy, "getaddrinfo %s %s %d %d %d %d %u", 432 hostname == NULL ? "^" : hostname, 433 servname == NULL ? "^" : servname, 434 hints == NULL ? -1 : hints->ai_flags, 435 hints == NULL ? -1 : hints->ai_family, 436 hints == NULL ? -1 : hints->ai_socktype, 437 hints == NULL ? -1 : hints->ai_protocol, 438 netid) < 0) { 439 goto exit; 440 } 441 // literal NULL byte at end, required by FrameworkListener 442 if (fputc(0, proxy) == EOF || 443 fflush(proxy) != 0) { 444 goto exit; 445 } 446 447 char buf[4]; 448 // read result code for gethostbyaddr 449 if (fread(buf, 1, sizeof(buf), proxy) != sizeof(buf)) { 450 goto exit; 451 } 452 453 int result_code = (int)strtol(buf, NULL, 10); 454 // verify the code itself 455 if (result_code != DnsProxyQueryResult) { 456 fread(buf, 1, sizeof(buf), proxy); 457 goto exit; 458 } 459 460 struct addrinfo* ai = NULL; 461 struct addrinfo** nextres = res; 462 while (1) { 463 int32_t have_more; 464 if (!readBE32(proxy, &have_more)) { 465 break; 466 } 467 if (have_more == 0) { 468 success = 1; 469 break; 470 } 471 472 struct addrinfo* ai = calloc(1, sizeof(struct addrinfo) + sizeof(struct sockaddr_storage)); 473 if (ai == NULL) { 474 break; 475 } 476 ai->ai_addr = (struct sockaddr*)(ai + 1); 477 478 // struct addrinfo { 479 // int ai_flags; /* AI_PASSIVE, AI_CANONNAME, AI_NUMERICHOST */ 480 // int ai_family; /* PF_xxx */ 481 // int ai_socktype; /* SOCK_xxx */ 482 // int ai_protocol; /* 0 or IPPROTO_xxx for IPv4 and IPv6 */ 483 // socklen_t ai_addrlen; /* length of ai_addr */ 484 // char *ai_canonname; /* canonical name for hostname */ 485 // struct sockaddr *ai_addr; /* binary address */ 486 // struct addrinfo *ai_next; /* next structure in linked list */ 487 // }; 488 489 // Read the struct piece by piece because we might be a 32-bit process 490 // talking to a 64-bit netd. 491 int32_t addr_len; 492 bool success = 493 readBE32(proxy, &ai->ai_flags) && 494 readBE32(proxy, &ai->ai_family) && 495 readBE32(proxy, &ai->ai_socktype) && 496 readBE32(proxy, &ai->ai_protocol) && 497 readBE32(proxy, &addr_len); 498 if (!success) { 499 break; 500 } 501 502 // Set ai_addrlen and read the ai_addr data. 503 ai->ai_addrlen = addr_len; 504 if (addr_len != 0) { 505 if ((size_t) addr_len > sizeof(struct sockaddr_storage)) { 506 // Bogus; too big. 507 break; 508 } 509 if (fread(ai->ai_addr, addr_len, 1, proxy) != 1) { 510 break; 511 } 512 } 513 514 // The string for ai_cannonname. 515 int32_t name_len; 516 if (!readBE32(proxy, &name_len)) { 517 break; 518 } 519 if (name_len != 0) { 520 ai->ai_canonname = (char*) malloc(name_len); 521 if (fread(ai->ai_canonname, name_len, 1, proxy) != 1) { 522 break; 523 } 524 if (ai->ai_canonname[name_len - 1] != '\0') { 525 // The proxy should be returning this 526 // NULL-terminated. 527 break; 528 } 529 } 530 531 *nextres = ai; 532 nextres = &ai->ai_next; 533 ai = NULL; 534 } 535 536 if (ai != NULL) { 537 // Clean up partially-built addrinfo that we never ended up 538 // attaching to the response. 539 freeaddrinfo(ai); 540 } 541 exit: 542 if (proxy != NULL) { 543 fclose(proxy); 544 } 545 546 if (success) { 547 return 0; 548 } 549 550 // Proxy failed; 551 // clean up memory we might've allocated. 552 if (*res) { 553 freeaddrinfo(*res); 554 *res = NULL; 555 } 556 return EAI_NODATA; 557 } 558 559 int 560 getaddrinfo(const char *hostname, const char *servname, 561 const struct addrinfo *hints, struct addrinfo **res) 562 { 563 return android_getaddrinfofornet(hostname, servname, hints, NETID_UNSET, MARK_UNSET, res); 564 } 565 566 int 567 android_getaddrinfofornet(const char *hostname, const char *servname, 568 const struct addrinfo *hints, unsigned netid, unsigned mark, struct addrinfo **res) 569 { 570 struct android_net_context netcontext = { 571 .app_netid = netid, 572 .app_mark = mark, 573 .dns_netid = netid, 574 .dns_mark = mark, 575 .uid = NET_CONTEXT_INVALID_UID, 576 }; 577 return android_getaddrinfofornetcontext(hostname, servname, hints, &netcontext, res); 578 } 579 580 int 581 android_getaddrinfofornetcontext(const char *hostname, const char *servname, 582 const struct addrinfo *hints, const struct android_net_context *netcontext, 583 struct addrinfo **res) 584 { 585 struct addrinfo sentinel; 586 struct addrinfo *cur; 587 int error = 0; 588 struct addrinfo ai; 589 struct addrinfo ai0; 590 struct addrinfo *pai; 591 const struct explore *ex; 592 593 /* hostname is allowed to be NULL */ 594 /* servname is allowed to be NULL */ 595 /* hints is allowed to be NULL */ 596 assert(res != NULL); 597 assert(netcontext != NULL); 598 memset(&sentinel, 0, sizeof(sentinel)); 599 cur = &sentinel; 600 pai = &ai; 601 pai->ai_flags = 0; 602 pai->ai_family = PF_UNSPEC; 603 pai->ai_socktype = ANY; 604 pai->ai_protocol = ANY; 605 pai->ai_addrlen = 0; 606 pai->ai_canonname = NULL; 607 pai->ai_addr = NULL; 608 pai->ai_next = NULL; 609 610 if (hostname == NULL && servname == NULL) 611 return EAI_NONAME; 612 if (hints) { 613 /* error check for hints */ 614 if (hints->ai_addrlen || hints->ai_canonname || 615 hints->ai_addr || hints->ai_next) 616 ERR(EAI_BADHINTS); /* xxx */ 617 if (hints->ai_flags & ~AI_MASK) 618 ERR(EAI_BADFLAGS); 619 switch (hints->ai_family) { 620 case PF_UNSPEC: 621 case PF_INET: 622 #ifdef INET6 623 case PF_INET6: 624 #endif 625 break; 626 default: 627 ERR(EAI_FAMILY); 628 } 629 memcpy(pai, hints, sizeof(*pai)); 630 631 /* 632 * if both socktype/protocol are specified, check if they 633 * are meaningful combination. 634 */ 635 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { 636 for (ex = explore; ex->e_af >= 0; ex++) { 637 if (pai->ai_family != ex->e_af) 638 continue; 639 if (ex->e_socktype == ANY) 640 continue; 641 if (ex->e_protocol == ANY) 642 continue; 643 if (pai->ai_socktype == ex->e_socktype 644 && pai->ai_protocol != ex->e_protocol) { 645 ERR(EAI_BADHINTS); 646 } 647 } 648 } 649 } 650 651 /* 652 * check for special cases. (1) numeric servname is disallowed if 653 * socktype/protocol are left unspecified. (2) servname is disallowed 654 * for raw and other inet{,6} sockets. 655 */ 656 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) 657 #ifdef PF_INET6 658 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) 659 #endif 660 ) { 661 ai0 = *pai; /* backup *pai */ 662 663 if (pai->ai_family == PF_UNSPEC) { 664 #ifdef PF_INET6 665 pai->ai_family = PF_INET6; 666 #else 667 pai->ai_family = PF_INET; 668 #endif 669 } 670 error = get_portmatch(pai, servname); 671 if (error) 672 ERR(error); 673 674 *pai = ai0; 675 } 676 677 ai0 = *pai; 678 679 /* NULL hostname, or numeric hostname */ 680 for (ex = explore; ex->e_af >= 0; ex++) { 681 *pai = ai0; 682 683 /* PF_UNSPEC entries are prepared for DNS queries only */ 684 if (ex->e_af == PF_UNSPEC) 685 continue; 686 687 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) 688 continue; 689 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) 690 continue; 691 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) 692 continue; 693 694 if (pai->ai_family == PF_UNSPEC) 695 pai->ai_family = ex->e_af; 696 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 697 pai->ai_socktype = ex->e_socktype; 698 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 699 pai->ai_protocol = ex->e_protocol; 700 701 if (hostname == NULL) 702 error = explore_null(pai, servname, &cur->ai_next); 703 else 704 error = explore_numeric_scope(pai, hostname, servname, 705 &cur->ai_next); 706 707 if (error) 708 goto free; 709 710 while (cur->ai_next) 711 cur = cur->ai_next; 712 } 713 714 /* 715 * XXX 716 * If numeric representation of AF1 can be interpreted as FQDN 717 * representation of AF2, we need to think again about the code below. 718 */ 719 if (sentinel.ai_next) 720 goto good; 721 722 if (hostname == NULL) 723 ERR(EAI_NODATA); 724 if (pai->ai_flags & AI_NUMERICHOST) 725 ERR(EAI_NONAME); 726 727 #if defined(__ANDROID__) 728 int gai_error = android_getaddrinfo_proxy( 729 hostname, servname, hints, res, netcontext->app_netid); 730 if (gai_error != EAI_SYSTEM) { 731 return gai_error; 732 } 733 #endif 734 735 /* 736 * hostname as alphabetical name. 737 * we would like to prefer AF_INET6 than AF_INET, so we'll make a 738 * outer loop by AFs. 739 */ 740 for (ex = explore; ex->e_af >= 0; ex++) { 741 *pai = ai0; 742 743 /* require exact match for family field */ 744 if (pai->ai_family != ex->e_af) 745 continue; 746 747 if (!MATCH(pai->ai_socktype, ex->e_socktype, 748 WILD_SOCKTYPE(ex))) { 749 continue; 750 } 751 if (!MATCH(pai->ai_protocol, ex->e_protocol, 752 WILD_PROTOCOL(ex))) { 753 continue; 754 } 755 756 if (pai->ai_socktype == ANY && ex->e_socktype != ANY) 757 pai->ai_socktype = ex->e_socktype; 758 if (pai->ai_protocol == ANY && ex->e_protocol != ANY) 759 pai->ai_protocol = ex->e_protocol; 760 761 error = explore_fqdn( 762 pai, hostname, servname, &cur->ai_next, netcontext); 763 764 while (cur && cur->ai_next) 765 cur = cur->ai_next; 766 } 767 768 /* XXX */ 769 if (sentinel.ai_next) 770 error = 0; 771 772 if (error) 773 goto free; 774 if (error == 0) { 775 if (sentinel.ai_next) { 776 good: 777 *res = sentinel.ai_next; 778 return SUCCESS; 779 } else 780 error = EAI_FAIL; 781 } 782 free: 783 bad: 784 if (sentinel.ai_next) 785 freeaddrinfo(sentinel.ai_next); 786 *res = NULL; 787 return error; 788 } 789 790 /* 791 * FQDN hostname, DNS lookup 792 */ 793 static int 794 explore_fqdn(const struct addrinfo *pai, const char *hostname, 795 const char *servname, struct addrinfo **res, 796 const struct android_net_context *netcontext) 797 { 798 struct addrinfo *result; 799 struct addrinfo *cur; 800 int error = 0; 801 static const ns_dtab dtab[] = { 802 NS_FILES_CB(_files_getaddrinfo, NULL) 803 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ 804 NS_NIS_CB(_yp_getaddrinfo, NULL) 805 { 0, 0, 0 } 806 }; 807 808 assert(pai != NULL); 809 /* hostname may be NULL */ 810 /* servname may be NULL */ 811 assert(res != NULL); 812 813 result = NULL; 814 815 /* 816 * if the servname does not match socktype/protocol, ignore it. 817 */ 818 if (get_portmatch(pai, servname) != 0) 819 return 0; 820 821 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", 822 default_dns_files, hostname, pai, netcontext)) { 823 case NS_TRYAGAIN: 824 error = EAI_AGAIN; 825 goto free; 826 case NS_UNAVAIL: 827 error = EAI_FAIL; 828 goto free; 829 case NS_NOTFOUND: 830 error = EAI_NODATA; 831 goto free; 832 case NS_SUCCESS: 833 error = 0; 834 for (cur = result; cur; cur = cur->ai_next) { 835 GET_PORT(cur, servname); 836 /* canonname should be filled already */ 837 } 838 break; 839 } 840 841 *res = result; 842 843 return 0; 844 845 free: 846 if (result) 847 freeaddrinfo(result); 848 return error; 849 } 850 851 /* 852 * hostname == NULL. 853 * passive socket -> anyaddr (0.0.0.0 or ::) 854 * non-passive socket -> localhost (127.0.0.1 or ::1) 855 */ 856 static int 857 explore_null(const struct addrinfo *pai, const char *servname, 858 struct addrinfo **res) 859 { 860 int s; 861 const struct afd *afd; 862 struct addrinfo *cur; 863 struct addrinfo sentinel; 864 int error; 865 866 assert(pai != NULL); 867 /* servname may be NULL */ 868 assert(res != NULL); 869 870 *res = NULL; 871 sentinel.ai_next = NULL; 872 cur = &sentinel; 873 874 /* 875 * filter out AFs that are not supported by the kernel 876 * XXX errno? 877 */ 878 s = socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); 879 if (s < 0) { 880 if (errno != EMFILE) 881 return 0; 882 } else 883 close(s); 884 885 /* 886 * if the servname does not match socktype/protocol, ignore it. 887 */ 888 if (get_portmatch(pai, servname) != 0) 889 return 0; 890 891 afd = find_afd(pai->ai_family); 892 if (afd == NULL) 893 return 0; 894 895 if (pai->ai_flags & AI_PASSIVE) { 896 GET_AI(cur->ai_next, afd, afd->a_addrany); 897 /* xxx meaningless? 898 * GET_CANONNAME(cur->ai_next, "anyaddr"); 899 */ 900 GET_PORT(cur->ai_next, servname); 901 } else { 902 GET_AI(cur->ai_next, afd, afd->a_loopback); 903 /* xxx meaningless? 904 * GET_CANONNAME(cur->ai_next, "localhost"); 905 */ 906 GET_PORT(cur->ai_next, servname); 907 } 908 cur = cur->ai_next; 909 910 *res = sentinel.ai_next; 911 return 0; 912 913 free: 914 if (sentinel.ai_next) 915 freeaddrinfo(sentinel.ai_next); 916 return error; 917 } 918 919 /* 920 * numeric hostname 921 */ 922 static int 923 explore_numeric(const struct addrinfo *pai, const char *hostname, 924 const char *servname, struct addrinfo **res, const char *canonname) 925 { 926 const struct afd *afd; 927 struct addrinfo *cur; 928 struct addrinfo sentinel; 929 int error; 930 char pton[PTON_MAX]; 931 932 assert(pai != NULL); 933 /* hostname may be NULL */ 934 /* servname may be NULL */ 935 assert(res != NULL); 936 937 *res = NULL; 938 sentinel.ai_next = NULL; 939 cur = &sentinel; 940 941 /* 942 * if the servname does not match socktype/protocol, ignore it. 943 */ 944 if (get_portmatch(pai, servname) != 0) 945 return 0; 946 947 afd = find_afd(pai->ai_family); 948 if (afd == NULL) 949 return 0; 950 951 switch (afd->a_af) { 952 #if 0 /*X/Open spec*/ 953 case AF_INET: 954 if (inet_aton(hostname, (struct in_addr *)pton) == 1) { 955 if (pai->ai_family == afd->a_af || 956 pai->ai_family == PF_UNSPEC /*?*/) { 957 GET_AI(cur->ai_next, afd, pton); 958 GET_PORT(cur->ai_next, servname); 959 if ((pai->ai_flags & AI_CANONNAME)) { 960 /* 961 * Set the numeric address itself as 962 * the canonical name, based on a 963 * clarification in rfc2553bis-03. 964 */ 965 GET_CANONNAME(cur->ai_next, canonname); 966 } 967 while (cur && cur->ai_next) 968 cur = cur->ai_next; 969 } else 970 ERR(EAI_FAMILY); /*xxx*/ 971 } 972 break; 973 #endif 974 default: 975 if (inet_pton(afd->a_af, hostname, pton) == 1) { 976 if (pai->ai_family == afd->a_af || 977 pai->ai_family == PF_UNSPEC /*?*/) { 978 GET_AI(cur->ai_next, afd, pton); 979 GET_PORT(cur->ai_next, servname); 980 if ((pai->ai_flags & AI_CANONNAME)) { 981 /* 982 * Set the numeric address itself as 983 * the canonical name, based on a 984 * clarification in rfc2553bis-03. 985 */ 986 GET_CANONNAME(cur->ai_next, canonname); 987 } 988 while (cur->ai_next) 989 cur = cur->ai_next; 990 } else 991 ERR(EAI_FAMILY); /*xxx*/ 992 } 993 break; 994 } 995 996 *res = sentinel.ai_next; 997 return 0; 998 999 free: 1000 bad: 1001 if (sentinel.ai_next) 1002 freeaddrinfo(sentinel.ai_next); 1003 return error; 1004 } 1005 1006 /* 1007 * numeric hostname with scope 1008 */ 1009 static int 1010 explore_numeric_scope(const struct addrinfo *pai, const char *hostname, 1011 const char *servname, struct addrinfo **res) 1012 { 1013 #if !defined(SCOPE_DELIMITER) || !defined(INET6) 1014 return explore_numeric(pai, hostname, servname, res, hostname); 1015 #else 1016 const struct afd *afd; 1017 struct addrinfo *cur; 1018 int error; 1019 char *cp, *hostname2 = NULL, *scope, *addr; 1020 struct sockaddr_in6 *sin6; 1021 1022 assert(pai != NULL); 1023 /* hostname may be NULL */ 1024 /* servname may be NULL */ 1025 assert(res != NULL); 1026 1027 /* 1028 * if the servname does not match socktype/protocol, ignore it. 1029 */ 1030 if (get_portmatch(pai, servname) != 0) 1031 return 0; 1032 1033 afd = find_afd(pai->ai_family); 1034 if (afd == NULL) 1035 return 0; 1036 1037 if (!afd->a_scoped) 1038 return explore_numeric(pai, hostname, servname, res, hostname); 1039 1040 cp = strchr(hostname, SCOPE_DELIMITER); 1041 if (cp == NULL) 1042 return explore_numeric(pai, hostname, servname, res, hostname); 1043 1044 /* 1045 * Handle special case of <scoped_address><delimiter><scope id> 1046 */ 1047 hostname2 = strdup(hostname); 1048 if (hostname2 == NULL) 1049 return EAI_MEMORY; 1050 /* terminate at the delimiter */ 1051 hostname2[cp - hostname] = '\0'; 1052 addr = hostname2; 1053 scope = cp + 1; 1054 1055 error = explore_numeric(pai, addr, servname, res, hostname); 1056 if (error == 0) { 1057 u_int32_t scopeid; 1058 1059 for (cur = *res; cur; cur = cur->ai_next) { 1060 if (cur->ai_family != AF_INET6) 1061 continue; 1062 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr; 1063 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) { 1064 free(hostname2); 1065 return(EAI_NODATA); /* XXX: is return OK? */ 1066 } 1067 sin6->sin6_scope_id = scopeid; 1068 } 1069 } 1070 1071 free(hostname2); 1072 1073 return error; 1074 #endif 1075 } 1076 1077 static int 1078 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str) 1079 { 1080 1081 assert(pai != NULL); 1082 assert(ai != NULL); 1083 assert(str != NULL); 1084 1085 if ((pai->ai_flags & AI_CANONNAME) != 0) { 1086 ai->ai_canonname = strdup(str); 1087 if (ai->ai_canonname == NULL) 1088 return EAI_MEMORY; 1089 } 1090 return 0; 1091 } 1092 1093 static struct addrinfo * 1094 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr) 1095 { 1096 char *p; 1097 struct addrinfo *ai; 1098 1099 assert(pai != NULL); 1100 assert(afd != NULL); 1101 assert(addr != NULL); 1102 1103 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) 1104 + (afd->a_socklen)); 1105 if (ai == NULL) 1106 return NULL; 1107 1108 memcpy(ai, pai, sizeof(struct addrinfo)); 1109 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); 1110 memset(ai->ai_addr, 0, (size_t)afd->a_socklen); 1111 1112 #ifdef HAVE_SA_LEN 1113 ai->ai_addr->sa_len = afd->a_socklen; 1114 #endif 1115 1116 ai->ai_addrlen = afd->a_socklen; 1117 #if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__) 1118 ai->__ai_pad0 = 0; 1119 #endif 1120 ai->ai_addr->sa_family = ai->ai_family = afd->a_af; 1121 p = (char *)(void *)(ai->ai_addr); 1122 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); 1123 return ai; 1124 } 1125 1126 static int 1127 get_portmatch(const struct addrinfo *ai, const char *servname) 1128 { 1129 1130 assert(ai != NULL); 1131 /* servname may be NULL */ 1132 1133 return get_port(ai, servname, 1); 1134 } 1135 1136 static int 1137 get_port(const struct addrinfo *ai, const char *servname, int matchonly) 1138 { 1139 const char *proto; 1140 struct servent *sp; 1141 int port; 1142 int allownumeric; 1143 1144 assert(ai != NULL); 1145 /* servname may be NULL */ 1146 1147 if (servname == NULL) 1148 return 0; 1149 switch (ai->ai_family) { 1150 case AF_INET: 1151 #ifdef AF_INET6 1152 case AF_INET6: 1153 #endif 1154 break; 1155 default: 1156 return 0; 1157 } 1158 1159 switch (ai->ai_socktype) { 1160 case SOCK_RAW: 1161 return EAI_SERVICE; 1162 case SOCK_DGRAM: 1163 case SOCK_STREAM: 1164 allownumeric = 1; 1165 break; 1166 case ANY: 1167 #if 1 /* ANDROID-SPECIFIC CHANGE TO MATCH GLIBC */ 1168 allownumeric = 1; 1169 #else 1170 allownumeric = 0; 1171 #endif 1172 break; 1173 default: 1174 return EAI_SOCKTYPE; 1175 } 1176 1177 port = str2number(servname); 1178 if (port >= 0) { 1179 if (!allownumeric) 1180 return EAI_SERVICE; 1181 if (port < 0 || port > 65535) 1182 return EAI_SERVICE; 1183 port = htons(port); 1184 } else { 1185 if (ai->ai_flags & AI_NUMERICSERV) 1186 return EAI_NONAME; 1187 1188 switch (ai->ai_socktype) { 1189 case SOCK_DGRAM: 1190 proto = "udp"; 1191 break; 1192 case SOCK_STREAM: 1193 proto = "tcp"; 1194 break; 1195 default: 1196 proto = NULL; 1197 break; 1198 } 1199 1200 if ((sp = getservbyname(servname, proto)) == NULL) 1201 return EAI_SERVICE; 1202 port = sp->s_port; 1203 } 1204 1205 if (!matchonly) { 1206 switch (ai->ai_family) { 1207 case AF_INET: 1208 ((struct sockaddr_in *)(void *) 1209 ai->ai_addr)->sin_port = port; 1210 break; 1211 #ifdef INET6 1212 case AF_INET6: 1213 ((struct sockaddr_in6 *)(void *) 1214 ai->ai_addr)->sin6_port = port; 1215 break; 1216 #endif 1217 } 1218 } 1219 1220 return 0; 1221 } 1222 1223 static const struct afd * 1224 find_afd(int af) 1225 { 1226 const struct afd *afd; 1227 1228 if (af == PF_UNSPEC) 1229 return NULL; 1230 for (afd = afdl; afd->a_af; afd++) { 1231 if (afd->a_af == af) 1232 return afd; 1233 } 1234 return NULL; 1235 } 1236 1237 #ifdef INET6 1238 /* convert a string to a scope identifier. XXX: IPv6 specific */ 1239 static int 1240 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) 1241 { 1242 u_long lscopeid; 1243 struct in6_addr *a6; 1244 char *ep; 1245 1246 assert(scope != NULL); 1247 assert(sin6 != NULL); 1248 assert(scopeid != NULL); 1249 1250 a6 = &sin6->sin6_addr; 1251 1252 /* empty scopeid portion is invalid */ 1253 if (*scope == '\0') 1254 return -1; 1255 1256 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { 1257 /* 1258 * We currently assume a one-to-one mapping between links 1259 * and interfaces, so we simply use interface indices for 1260 * like-local scopes. 1261 */ 1262 *scopeid = if_nametoindex(scope); 1263 if (*scopeid == 0) 1264 goto trynumeric; 1265 return 0; 1266 } 1267 1268 /* still unclear about literal, allow numeric only - placeholder */ 1269 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 1270 goto trynumeric; 1271 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 1272 goto trynumeric; 1273 else 1274 goto trynumeric; /* global */ 1275 1276 /* try to convert to a numeric id as a last resort */ 1277 trynumeric: 1278 errno = 0; 1279 lscopeid = strtoul(scope, &ep, 10); 1280 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); 1281 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) 1282 return 0; 1283 else 1284 return -1; 1285 } 1286 #endif 1287 1288 /* code duplicate with gethnamaddr.c */ 1289 1290 static const char AskedForGot[] = 1291 "gethostby*.getanswer: asked for \"%s\", got \"%s\""; 1292 1293 static struct addrinfo * 1294 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype, 1295 const struct addrinfo *pai) 1296 { 1297 struct addrinfo sentinel, *cur; 1298 struct addrinfo ai; 1299 const struct afd *afd; 1300 char *canonname; 1301 const HEADER *hp; 1302 const u_char *cp; 1303 int n; 1304 const u_char *eom; 1305 char *bp, *ep; 1306 int type, class, ancount, qdcount; 1307 int haveanswer, had_error; 1308 char tbuf[MAXDNAME]; 1309 int (*name_ok) (const char *); 1310 char hostbuf[8*1024]; 1311 1312 assert(answer != NULL); 1313 assert(qname != NULL); 1314 assert(pai != NULL); 1315 1316 memset(&sentinel, 0, sizeof(sentinel)); 1317 cur = &sentinel; 1318 1319 canonname = NULL; 1320 eom = answer->buf + anslen; 1321 switch (qtype) { 1322 case T_A: 1323 case T_AAAA: 1324 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ 1325 name_ok = res_hnok; 1326 break; 1327 default: 1328 return NULL; /* XXX should be abort(); */ 1329 } 1330 /* 1331 * find first satisfactory answer 1332 */ 1333 hp = &answer->hdr; 1334 ancount = ntohs(hp->ancount); 1335 qdcount = ntohs(hp->qdcount); 1336 bp = hostbuf; 1337 ep = hostbuf + sizeof hostbuf; 1338 cp = answer->buf + HFIXEDSZ; 1339 if (qdcount != 1) { 1340 h_errno = NO_RECOVERY; 1341 return (NULL); 1342 } 1343 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1344 if ((n < 0) || !(*name_ok)(bp)) { 1345 h_errno = NO_RECOVERY; 1346 return (NULL); 1347 } 1348 cp += n + QFIXEDSZ; 1349 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { 1350 /* res_send() has already verified that the query name is the 1351 * same as the one we sent; this just gets the expanded name 1352 * (i.e., with the succeeding search-domain tacked on). 1353 */ 1354 n = strlen(bp) + 1; /* for the \0 */ 1355 if (n >= MAXHOSTNAMELEN) { 1356 h_errno = NO_RECOVERY; 1357 return (NULL); 1358 } 1359 canonname = bp; 1360 bp += n; 1361 /* The qname can be abbreviated, but h_name is now absolute. */ 1362 qname = canonname; 1363 } 1364 haveanswer = 0; 1365 had_error = 0; 1366 while (ancount-- > 0 && cp < eom && !had_error) { 1367 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 1368 if ((n < 0) || !(*name_ok)(bp)) { 1369 had_error++; 1370 continue; 1371 } 1372 cp += n; /* name */ 1373 type = _getshort(cp); 1374 cp += INT16SZ; /* type */ 1375 class = _getshort(cp); 1376 cp += INT16SZ + INT32SZ; /* class, TTL */ 1377 n = _getshort(cp); 1378 cp += INT16SZ; /* len */ 1379 if (class != C_IN) { 1380 /* XXX - debug? syslog? */ 1381 cp += n; 1382 continue; /* XXX - had_error++ ? */ 1383 } 1384 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && 1385 type == T_CNAME) { 1386 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); 1387 if ((n < 0) || !(*name_ok)(tbuf)) { 1388 had_error++; 1389 continue; 1390 } 1391 cp += n; 1392 /* Get canonical name. */ 1393 n = strlen(tbuf) + 1; /* for the \0 */ 1394 if (n > ep - bp || n >= MAXHOSTNAMELEN) { 1395 had_error++; 1396 continue; 1397 } 1398 strlcpy(bp, tbuf, (size_t)(ep - bp)); 1399 canonname = bp; 1400 bp += n; 1401 continue; 1402 } 1403 if (qtype == T_ANY) { 1404 if (!(type == T_A || type == T_AAAA)) { 1405 cp += n; 1406 continue; 1407 } 1408 } else if (type != qtype) { 1409 if (type != T_KEY && type != T_SIG) 1410 syslog(LOG_NOTICE|LOG_AUTH, 1411 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", 1412 qname, p_class(C_IN), p_type(qtype), 1413 p_type(type)); 1414 cp += n; 1415 continue; /* XXX - had_error++ ? */ 1416 } 1417 switch (type) { 1418 case T_A: 1419 case T_AAAA: 1420 if (strcasecmp(canonname, bp) != 0) { 1421 syslog(LOG_NOTICE|LOG_AUTH, 1422 AskedForGot, canonname, bp); 1423 cp += n; 1424 continue; /* XXX - had_error++ ? */ 1425 } 1426 if (type == T_A && n != INADDRSZ) { 1427 cp += n; 1428 continue; 1429 } 1430 if (type == T_AAAA && n != IN6ADDRSZ) { 1431 cp += n; 1432 continue; 1433 } 1434 if (type == T_AAAA) { 1435 struct in6_addr in6; 1436 memcpy(&in6, cp, IN6ADDRSZ); 1437 if (IN6_IS_ADDR_V4MAPPED(&in6)) { 1438 cp += n; 1439 continue; 1440 } 1441 } 1442 if (!haveanswer) { 1443 int nn; 1444 1445 canonname = bp; 1446 nn = strlen(bp) + 1; /* for the \0 */ 1447 bp += nn; 1448 } 1449 1450 /* don't overwrite pai */ 1451 ai = *pai; 1452 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6; 1453 afd = find_afd(ai.ai_family); 1454 if (afd == NULL) { 1455 cp += n; 1456 continue; 1457 } 1458 cur->ai_next = get_ai(&ai, afd, (const char *)cp); 1459 if (cur->ai_next == NULL) 1460 had_error++; 1461 while (cur && cur->ai_next) 1462 cur = cur->ai_next; 1463 cp += n; 1464 break; 1465 default: 1466 abort(); 1467 } 1468 if (!had_error) 1469 haveanswer++; 1470 } 1471 if (haveanswer) { 1472 if (!canonname) 1473 (void)get_canonname(pai, sentinel.ai_next, qname); 1474 else 1475 (void)get_canonname(pai, sentinel.ai_next, canonname); 1476 h_errno = NETDB_SUCCESS; 1477 return sentinel.ai_next; 1478 } 1479 1480 h_errno = NO_RECOVERY; 1481 return NULL; 1482 } 1483 1484 struct addrinfo_sort_elem { 1485 struct addrinfo *ai; 1486 int has_src_addr; 1487 sockaddr_union src_addr; 1488 int original_order; 1489 }; 1490 1491 /*ARGSUSED*/ 1492 static int 1493 _get_scope(const struct sockaddr *addr) 1494 { 1495 if (addr->sa_family == AF_INET6) { 1496 const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr; 1497 if (IN6_IS_ADDR_MULTICAST(&addr6->sin6_addr)) { 1498 return IPV6_ADDR_MC_SCOPE(&addr6->sin6_addr); 1499 } else if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr) || 1500 IN6_IS_ADDR_LINKLOCAL(&addr6->sin6_addr)) { 1501 /* 1502 * RFC 4291 section 2.5.3 says loopback is to be treated as having 1503 * link-local scope. 1504 */ 1505 return IPV6_ADDR_SCOPE_LINKLOCAL; 1506 } else if (IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr)) { 1507 return IPV6_ADDR_SCOPE_SITELOCAL; 1508 } else { 1509 return IPV6_ADDR_SCOPE_GLOBAL; 1510 } 1511 } else if (addr->sa_family == AF_INET) { 1512 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr; 1513 unsigned long int na = ntohl(addr4->sin_addr.s_addr); 1514 1515 if (IN_LOOPBACK(na) || /* 127.0.0.0/8 */ 1516 (na & 0xffff0000) == 0xa9fe0000) { /* 169.254.0.0/16 */ 1517 return IPV6_ADDR_SCOPE_LINKLOCAL; 1518 } else { 1519 /* 1520 * RFC 6724 section 3.2. Other IPv4 addresses, including private addresses 1521 * and shared addresses (100.64.0.0/10), are assigned global scope. 1522 */ 1523 return IPV6_ADDR_SCOPE_GLOBAL; 1524 } 1525 } else { 1526 /* 1527 * This should never happen. 1528 * Return a scope with low priority as a last resort. 1529 */ 1530 return IPV6_ADDR_SCOPE_NODELOCAL; 1531 } 1532 } 1533 1534 /* These macros are modelled after the ones in <netinet/in6.h>. */ 1535 1536 /* RFC 4380, section 2.6 */ 1537 #define IN6_IS_ADDR_TEREDO(a) \ 1538 ((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == ntohl(0x20010000))) 1539 1540 /* RFC 3056, section 2. */ 1541 #define IN6_IS_ADDR_6TO4(a) \ 1542 (((a)->s6_addr[0] == 0x20) && ((a)->s6_addr[1] == 0x02)) 1543 1544 /* 6bone testing address area (3ffe::/16), deprecated in RFC 3701. */ 1545 #define IN6_IS_ADDR_6BONE(a) \ 1546 (((a)->s6_addr[0] == 0x3f) && ((a)->s6_addr[1] == 0xfe)) 1547 1548 /* 1549 * Get the label for a given IPv4/IPv6 address. 1550 * RFC 6724, section 2.1. 1551 */ 1552 1553 /*ARGSUSED*/ 1554 static int 1555 _get_label(const struct sockaddr *addr) 1556 { 1557 if (addr->sa_family == AF_INET) { 1558 return 4; 1559 } else if (addr->sa_family == AF_INET6) { 1560 const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *) addr; 1561 if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr)) { 1562 return 0; 1563 } else if (IN6_IS_ADDR_V4MAPPED(&addr6->sin6_addr)) { 1564 return 4; 1565 } else if (IN6_IS_ADDR_6TO4(&addr6->sin6_addr)) { 1566 return 2; 1567 } else if (IN6_IS_ADDR_TEREDO(&addr6->sin6_addr)) { 1568 return 5; 1569 } else if (IN6_IS_ADDR_ULA(&addr6->sin6_addr)) { 1570 return 13; 1571 } else if (IN6_IS_ADDR_V4COMPAT(&addr6->sin6_addr)) { 1572 return 3; 1573 } else if (IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr)) { 1574 return 11; 1575 } else if (IN6_IS_ADDR_6BONE(&addr6->sin6_addr)) { 1576 return 12; 1577 } else { 1578 /* All other IPv6 addresses, including global unicast addresses. */ 1579 return 1; 1580 } 1581 } else { 1582 /* 1583 * This should never happen. 1584 * Return a semi-random label as a last resort. 1585 */ 1586 return 1; 1587 } 1588 } 1589 1590 /* 1591 * Get the precedence for a given IPv4/IPv6 address. 1592 * RFC 6724, section 2.1. 1593 */ 1594 1595 /*ARGSUSED*/ 1596 static int 1597 _get_precedence(const struct sockaddr *addr) 1598 { 1599 if (addr->sa_family == AF_INET) { 1600 return 35; 1601 } else if (addr->sa_family == AF_INET6) { 1602 const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr; 1603 if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr)) { 1604 return 50; 1605 } else if (IN6_IS_ADDR_V4MAPPED(&addr6->sin6_addr)) { 1606 return 35; 1607 } else if (IN6_IS_ADDR_6TO4(&addr6->sin6_addr)) { 1608 return 30; 1609 } else if (IN6_IS_ADDR_TEREDO(&addr6->sin6_addr)) { 1610 return 5; 1611 } else if (IN6_IS_ADDR_ULA(&addr6->sin6_addr)) { 1612 return 3; 1613 } else if (IN6_IS_ADDR_V4COMPAT(&addr6->sin6_addr) || 1614 IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr) || 1615 IN6_IS_ADDR_6BONE(&addr6->sin6_addr)) { 1616 return 1; 1617 } else { 1618 /* All other IPv6 addresses, including global unicast addresses. */ 1619 return 40; 1620 } 1621 } else { 1622 return 1; 1623 } 1624 } 1625 1626 /* 1627 * Find number of matching initial bits between the two addresses a1 and a2. 1628 */ 1629 1630 /*ARGSUSED*/ 1631 static int 1632 _common_prefix_len(const struct in6_addr *a1, const struct in6_addr *a2) 1633 { 1634 const char *p1 = (const char *)a1; 1635 const char *p2 = (const char *)a2; 1636 unsigned i; 1637 1638 for (i = 0; i < sizeof(*a1); ++i) { 1639 int x, j; 1640 1641 if (p1[i] == p2[i]) { 1642 continue; 1643 } 1644 x = p1[i] ^ p2[i]; 1645 for (j = 0; j < CHAR_BIT; ++j) { 1646 if (x & (1 << (CHAR_BIT - 1))) { 1647 return i * CHAR_BIT + j; 1648 } 1649 x <<= 1; 1650 } 1651 } 1652 return sizeof(*a1) * CHAR_BIT; 1653 } 1654 1655 /* 1656 * Compare two source/destination address pairs. 1657 * RFC 6724, section 6. 1658 */ 1659 1660 /*ARGSUSED*/ 1661 static int 1662 _rfc6724_compare(const void *ptr1, const void* ptr2) 1663 { 1664 const struct addrinfo_sort_elem *a1 = (const struct addrinfo_sort_elem *)ptr1; 1665 const struct addrinfo_sort_elem *a2 = (const struct addrinfo_sort_elem *)ptr2; 1666 int scope_src1, scope_dst1, scope_match1; 1667 int scope_src2, scope_dst2, scope_match2; 1668 int label_src1, label_dst1, label_match1; 1669 int label_src2, label_dst2, label_match2; 1670 int precedence1, precedence2; 1671 int prefixlen1, prefixlen2; 1672 1673 /* Rule 1: Avoid unusable destinations. */ 1674 if (a1->has_src_addr != a2->has_src_addr) { 1675 return a2->has_src_addr - a1->has_src_addr; 1676 } 1677 1678 /* Rule 2: Prefer matching scope. */ 1679 scope_src1 = _get_scope(&a1->src_addr.generic); 1680 scope_dst1 = _get_scope(a1->ai->ai_addr); 1681 scope_match1 = (scope_src1 == scope_dst1); 1682 1683 scope_src2 = _get_scope(&a2->src_addr.generic); 1684 scope_dst2 = _get_scope(a2->ai->ai_addr); 1685 scope_match2 = (scope_src2 == scope_dst2); 1686 1687 if (scope_match1 != scope_match2) { 1688 return scope_match2 - scope_match1; 1689 } 1690 1691 /* 1692 * Rule 3: Avoid deprecated addresses. 1693 * TODO(sesse): We don't currently have a good way of finding this. 1694 */ 1695 1696 /* 1697 * Rule 4: Prefer home addresses. 1698 * TODO(sesse): We don't currently have a good way of finding this. 1699 */ 1700 1701 /* Rule 5: Prefer matching label. */ 1702 label_src1 = _get_label(&a1->src_addr.generic); 1703 label_dst1 = _get_label(a1->ai->ai_addr); 1704 label_match1 = (label_src1 == label_dst1); 1705 1706 label_src2 = _get_label(&a2->src_addr.generic); 1707 label_dst2 = _get_label(a2->ai->ai_addr); 1708 label_match2 = (label_src2 == label_dst2); 1709 1710 if (label_match1 != label_match2) { 1711 return label_match2 - label_match1; 1712 } 1713 1714 /* Rule 6: Prefer higher precedence. */ 1715 precedence1 = _get_precedence(a1->ai->ai_addr); 1716 precedence2 = _get_precedence(a2->ai->ai_addr); 1717 if (precedence1 != precedence2) { 1718 return precedence2 - precedence1; 1719 } 1720 1721 /* 1722 * Rule 7: Prefer native transport. 1723 * TODO(sesse): We don't currently have a good way of finding this. 1724 */ 1725 1726 /* Rule 8: Prefer smaller scope. */ 1727 if (scope_dst1 != scope_dst2) { 1728 return scope_dst1 - scope_dst2; 1729 } 1730 1731 /* 1732 * Rule 9: Use longest matching prefix. 1733 * We implement this for IPv6 only, as the rules in RFC 6724 don't seem 1734 * to work very well directly applied to IPv4. (glibc uses information from 1735 * the routing table for a custom IPv4 implementation here.) 1736 */ 1737 if (a1->has_src_addr && a1->ai->ai_addr->sa_family == AF_INET6 && 1738 a2->has_src_addr && a2->ai->ai_addr->sa_family == AF_INET6) { 1739 const struct sockaddr_in6 *a1_src = &a1->src_addr.in6; 1740 const struct sockaddr_in6 *a1_dst = (const struct sockaddr_in6 *)a1->ai->ai_addr; 1741 const struct sockaddr_in6 *a2_src = &a2->src_addr.in6; 1742 const struct sockaddr_in6 *a2_dst = (const struct sockaddr_in6 *)a2->ai->ai_addr; 1743 prefixlen1 = _common_prefix_len(&a1_src->sin6_addr, &a1_dst->sin6_addr); 1744 prefixlen2 = _common_prefix_len(&a2_src->sin6_addr, &a2_dst->sin6_addr); 1745 if (prefixlen1 != prefixlen2) { 1746 return prefixlen2 - prefixlen1; 1747 } 1748 } 1749 1750 /* 1751 * Rule 10: Leave the order unchanged. 1752 * We need this since qsort() is not necessarily stable. 1753 */ 1754 return a1->original_order - a2->original_order; 1755 } 1756 1757 /* 1758 * Find the source address that will be used if trying to connect to the given 1759 * address. src_addr must be large enough to hold a struct sockaddr_in6. 1760 * 1761 * Returns 1 if a source address was found, 0 if the address is unreachable, 1762 * and -1 if a fatal error occurred. If 0 or -1, the contents of src_addr are 1763 * undefined. 1764 */ 1765 1766 /*ARGSUSED*/ 1767 static int 1768 _find_src_addr(const struct sockaddr *addr, struct sockaddr *src_addr, unsigned mark, uid_t uid) 1769 { 1770 int sock; 1771 int ret; 1772 socklen_t len; 1773 1774 switch (addr->sa_family) { 1775 case AF_INET: 1776 len = sizeof(struct sockaddr_in); 1777 break; 1778 case AF_INET6: 1779 len = sizeof(struct sockaddr_in6); 1780 break; 1781 default: 1782 /* No known usable source address for non-INET families. */ 1783 return 0; 1784 } 1785 1786 sock = socket(addr->sa_family, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP); 1787 if (sock == -1) { 1788 if (errno == EAFNOSUPPORT) { 1789 return 0; 1790 } else { 1791 return -1; 1792 } 1793 } 1794 if (mark != MARK_UNSET && setsockopt(sock, SOL_SOCKET, SO_MARK, &mark, sizeof(mark)) < 0) 1795 return 0; 1796 if (uid > 0 && uid != NET_CONTEXT_INVALID_UID && fchown(sock, uid, (gid_t)-1) < 0) 1797 return 0; 1798 do { 1799 ret = __connect(sock, addr, len); 1800 } while (ret == -1 && errno == EINTR); 1801 1802 if (ret == -1) { 1803 close(sock); 1804 return 0; 1805 } 1806 1807 if (src_addr && getsockname(sock, src_addr, &len) == -1) { 1808 close(sock); 1809 return -1; 1810 } 1811 close(sock); 1812 return 1; 1813 } 1814 1815 /* 1816 * Sort the linked list starting at sentinel->ai_next in RFC6724 order. 1817 * Will leave the list unchanged if an error occurs. 1818 */ 1819 1820 /*ARGSUSED*/ 1821 static void 1822 _rfc6724_sort(struct addrinfo *list_sentinel, unsigned mark, uid_t uid) 1823 { 1824 struct addrinfo *cur; 1825 int nelem = 0, i; 1826 struct addrinfo_sort_elem *elems; 1827 1828 cur = list_sentinel->ai_next; 1829 while (cur) { 1830 ++nelem; 1831 cur = cur->ai_next; 1832 } 1833 1834 elems = (struct addrinfo_sort_elem *)malloc(nelem * sizeof(struct addrinfo_sort_elem)); 1835 if (elems == NULL) { 1836 goto error; 1837 } 1838 1839 /* 1840 * Convert the linked list to an array that also contains the candidate 1841 * source address for each destination address. 1842 */ 1843 for (i = 0, cur = list_sentinel->ai_next; i < nelem; ++i, cur = cur->ai_next) { 1844 int has_src_addr; 1845 assert(cur != NULL); 1846 elems[i].ai = cur; 1847 elems[i].original_order = i; 1848 1849 has_src_addr = _find_src_addr(cur->ai_addr, &elems[i].src_addr.generic, mark, uid); 1850 if (has_src_addr == -1) { 1851 goto error; 1852 } 1853 elems[i].has_src_addr = has_src_addr; 1854 } 1855 1856 /* Sort the addresses, and rearrange the linked list so it matches the sorted order. */ 1857 qsort((void *)elems, nelem, sizeof(struct addrinfo_sort_elem), _rfc6724_compare); 1858 1859 list_sentinel->ai_next = elems[0].ai; 1860 for (i = 0; i < nelem - 1; ++i) { 1861 elems[i].ai->ai_next = elems[i + 1].ai; 1862 } 1863 elems[nelem - 1].ai->ai_next = NULL; 1864 1865 error: 1866 free(elems); 1867 } 1868 1869 /*ARGSUSED*/ 1870 static int 1871 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) 1872 { 1873 struct addrinfo *ai; 1874 querybuf *buf, *buf2; 1875 const char *name; 1876 const struct addrinfo *pai; 1877 struct addrinfo sentinel, *cur; 1878 struct res_target q, q2; 1879 res_state res; 1880 const struct android_net_context *netcontext; 1881 1882 name = va_arg(ap, char *); 1883 pai = va_arg(ap, const struct addrinfo *); 1884 netcontext = va_arg(ap, const struct android_net_context *); 1885 //fprintf(stderr, "_dns_getaddrinfo() name = '%s'\n", name); 1886 1887 memset(&q, 0, sizeof(q)); 1888 memset(&q2, 0, sizeof(q2)); 1889 memset(&sentinel, 0, sizeof(sentinel)); 1890 cur = &sentinel; 1891 1892 buf = malloc(sizeof(*buf)); 1893 if (buf == NULL) { 1894 h_errno = NETDB_INTERNAL; 1895 return NS_NOTFOUND; 1896 } 1897 buf2 = malloc(sizeof(*buf2)); 1898 if (buf2 == NULL) { 1899 free(buf); 1900 h_errno = NETDB_INTERNAL; 1901 return NS_NOTFOUND; 1902 } 1903 1904 switch (pai->ai_family) { 1905 case AF_UNSPEC: 1906 /* prefer IPv6 */ 1907 q.name = name; 1908 q.qclass = C_IN; 1909 q.answer = buf->buf; 1910 q.anslen = sizeof(buf->buf); 1911 int query_ipv6 = 1, query_ipv4 = 1; 1912 if (pai->ai_flags & AI_ADDRCONFIG) { 1913 query_ipv6 = _have_ipv6(netcontext->app_mark, netcontext->uid); 1914 query_ipv4 = _have_ipv4(netcontext->app_mark, netcontext->uid); 1915 } 1916 if (query_ipv6) { 1917 q.qtype = T_AAAA; 1918 if (query_ipv4) { 1919 q.next = &q2; 1920 q2.name = name; 1921 q2.qclass = C_IN; 1922 q2.qtype = T_A; 1923 q2.answer = buf2->buf; 1924 q2.anslen = sizeof(buf2->buf); 1925 } 1926 } else if (query_ipv4) { 1927 q.qtype = T_A; 1928 } else { 1929 free(buf); 1930 free(buf2); 1931 return NS_NOTFOUND; 1932 } 1933 break; 1934 case AF_INET: 1935 q.name = name; 1936 q.qclass = C_IN; 1937 q.qtype = T_A; 1938 q.answer = buf->buf; 1939 q.anslen = sizeof(buf->buf); 1940 break; 1941 case AF_INET6: 1942 q.name = name; 1943 q.qclass = C_IN; 1944 q.qtype = T_AAAA; 1945 q.answer = buf->buf; 1946 q.anslen = sizeof(buf->buf); 1947 break; 1948 default: 1949 free(buf); 1950 free(buf2); 1951 return NS_UNAVAIL; 1952 } 1953 1954 res = __res_get_state(); 1955 if (res == NULL) { 1956 free(buf); 1957 free(buf2); 1958 return NS_NOTFOUND; 1959 } 1960 1961 /* this just sets our netid val in the thread private data so we don't have to 1962 * modify the api's all the way down to res_send.c's res_nsend. We could 1963 * fully populate the thread private data here, but if we get down there 1964 * and have a cache hit that would be wasted, so we do the rest there on miss 1965 */ 1966 res_setnetid(res, netcontext->dns_netid); 1967 res_setmark(res, netcontext->dns_mark); 1968 if (res_searchN(name, &q, res) < 0) { 1969 __res_put_state(res); 1970 free(buf); 1971 free(buf2); 1972 return NS_NOTFOUND; 1973 } 1974 ai = getanswer(buf, q.n, q.name, q.qtype, pai); 1975 if (ai) { 1976 cur->ai_next = ai; 1977 while (cur && cur->ai_next) 1978 cur = cur->ai_next; 1979 } 1980 if (q.next) { 1981 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); 1982 if (ai) 1983 cur->ai_next = ai; 1984 } 1985 free(buf); 1986 free(buf2); 1987 if (sentinel.ai_next == NULL) { 1988 __res_put_state(res); 1989 switch (h_errno) { 1990 case HOST_NOT_FOUND: 1991 return NS_NOTFOUND; 1992 case TRY_AGAIN: 1993 return NS_TRYAGAIN; 1994 default: 1995 return NS_UNAVAIL; 1996 } 1997 } 1998 1999 _rfc6724_sort(&sentinel, netcontext->app_mark, netcontext->uid); 2000 2001 __res_put_state(res); 2002 2003 *((struct addrinfo **)rv) = sentinel.ai_next; 2004 return NS_SUCCESS; 2005 } 2006 2007 static void 2008 _sethtent(FILE **hostf) 2009 { 2010 2011 if (!*hostf) 2012 *hostf = fopen(_PATH_HOSTS, "re"); 2013 else 2014 rewind(*hostf); 2015 } 2016 2017 static void 2018 _endhtent(FILE **hostf) 2019 { 2020 2021 if (*hostf) { 2022 (void) fclose(*hostf); 2023 *hostf = NULL; 2024 } 2025 } 2026 2027 static struct addrinfo * 2028 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai) 2029 { 2030 char *p; 2031 char *cp, *tname, *cname; 2032 struct addrinfo hints, *res0, *res; 2033 int error; 2034 const char *addr; 2035 char hostbuf[8*1024]; 2036 2037 // fprintf(stderr, "_gethtent() name = '%s'\n", name); 2038 assert(name != NULL); 2039 assert(pai != NULL); 2040 2041 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re"))) 2042 return (NULL); 2043 again: 2044 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf))) 2045 return (NULL); 2046 if (*p == '#') 2047 goto again; 2048 if (!(cp = strpbrk(p, "#\n"))) 2049 goto again; 2050 *cp = '\0'; 2051 if (!(cp = strpbrk(p, " \t"))) 2052 goto again; 2053 *cp++ = '\0'; 2054 addr = p; 2055 /* if this is not something we're looking for, skip it. */ 2056 cname = NULL; 2057 while (cp && *cp) { 2058 if (*cp == ' ' || *cp == '\t') { 2059 cp++; 2060 continue; 2061 } 2062 if (!cname) 2063 cname = cp; 2064 tname = cp; 2065 if ((cp = strpbrk(cp, " \t")) != NULL) 2066 *cp++ = '\0'; 2067 // fprintf(stderr, "\ttname = '%s'", tname); 2068 if (strcasecmp(name, tname) == 0) 2069 goto found; 2070 } 2071 goto again; 2072 2073 found: 2074 hints = *pai; 2075 hints.ai_flags = AI_NUMERICHOST; 2076 error = getaddrinfo(addr, NULL, &hints, &res0); 2077 if (error) 2078 goto again; 2079 for (res = res0; res; res = res->ai_next) { 2080 /* cover it up */ 2081 res->ai_flags = pai->ai_flags; 2082 2083 if (pai->ai_flags & AI_CANONNAME) { 2084 if (get_canonname(pai, res, cname) != 0) { 2085 freeaddrinfo(res0); 2086 goto again; 2087 } 2088 } 2089 } 2090 return res0; 2091 } 2092 2093 /*ARGSUSED*/ 2094 static int 2095 _files_getaddrinfo(void *rv, void *cb_data, va_list ap) 2096 { 2097 const char *name; 2098 const struct addrinfo *pai; 2099 struct addrinfo sentinel, *cur; 2100 struct addrinfo *p; 2101 FILE *hostf = NULL; 2102 2103 name = va_arg(ap, char *); 2104 pai = va_arg(ap, struct addrinfo *); 2105 2106 // fprintf(stderr, "_files_getaddrinfo() name = '%s'\n", name); 2107 memset(&sentinel, 0, sizeof(sentinel)); 2108 cur = &sentinel; 2109 2110 _sethtent(&hostf); 2111 while ((p = _gethtent(&hostf, name, pai)) != NULL) { 2112 cur->ai_next = p; 2113 while (cur && cur->ai_next) 2114 cur = cur->ai_next; 2115 } 2116 _endhtent(&hostf); 2117 2118 *((struct addrinfo **)rv) = sentinel.ai_next; 2119 if (sentinel.ai_next == NULL) 2120 return NS_NOTFOUND; 2121 return NS_SUCCESS; 2122 } 2123 2124 /* resolver logic */ 2125 2126 /* 2127 * Formulate a normal query, send, and await answer. 2128 * Returned answer is placed in supplied buffer "answer". 2129 * Perform preliminary check of answer, returning success only 2130 * if no error is indicated and the answer count is nonzero. 2131 * Return the size of the response on success, -1 on error. 2132 * Error number is left in h_errno. 2133 * 2134 * Caller must parse answer and determine whether it answers the question. 2135 */ 2136 static int 2137 res_queryN(const char *name, /* domain name */ struct res_target *target, 2138 res_state res) 2139 { 2140 u_char buf[MAXPACKET]; 2141 HEADER *hp; 2142 int n; 2143 struct res_target *t; 2144 int rcode; 2145 int ancount; 2146 2147 assert(name != NULL); 2148 /* XXX: target may be NULL??? */ 2149 2150 rcode = NOERROR; 2151 ancount = 0; 2152 2153 for (t = target; t; t = t->next) { 2154 int class, type; 2155 u_char *answer; 2156 int anslen; 2157 2158 hp = (HEADER *)(void *)t->answer; 2159 hp->rcode = NOERROR; /* default */ 2160 2161 /* make it easier... */ 2162 class = t->qclass; 2163 type = t->qtype; 2164 answer = t->answer; 2165 anslen = t->anslen; 2166 #ifdef DEBUG 2167 if (res->options & RES_DEBUG) 2168 printf(";; res_nquery(%s, %d, %d)\n", name, class, type); 2169 #endif 2170 2171 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL, 2172 buf, sizeof(buf)); 2173 #ifdef RES_USE_EDNS0 2174 if (n > 0 && (res->options & RES_USE_EDNS0) != 0) 2175 n = res_nopt(res, n, buf, sizeof(buf), anslen); 2176 #endif 2177 if (n <= 0) { 2178 #ifdef DEBUG 2179 if (res->options & RES_DEBUG) 2180 printf(";; res_nquery: mkquery failed\n"); 2181 #endif 2182 h_errno = NO_RECOVERY; 2183 return n; 2184 } 2185 n = res_nsend(res, buf, n, answer, anslen); 2186 #if 0 2187 if (n < 0) { 2188 #ifdef DEBUG 2189 if (res->options & RES_DEBUG) 2190 printf(";; res_query: send error\n"); 2191 #endif 2192 h_errno = TRY_AGAIN; 2193 return n; 2194 } 2195 #endif 2196 2197 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { 2198 rcode = hp->rcode; /* record most recent error */ 2199 #ifdef DEBUG 2200 if (res->options & RES_DEBUG) 2201 printf(";; rcode = %u, ancount=%u\n", hp->rcode, 2202 ntohs(hp->ancount)); 2203 #endif 2204 continue; 2205 } 2206 2207 ancount += ntohs(hp->ancount); 2208 2209 t->n = n; 2210 } 2211 2212 if (ancount == 0) { 2213 switch (rcode) { 2214 case NXDOMAIN: 2215 h_errno = HOST_NOT_FOUND; 2216 break; 2217 case SERVFAIL: 2218 h_errno = TRY_AGAIN; 2219 break; 2220 case NOERROR: 2221 h_errno = NO_DATA; 2222 break; 2223 case FORMERR: 2224 case NOTIMP: 2225 case REFUSED: 2226 default: 2227 h_errno = NO_RECOVERY; 2228 break; 2229 } 2230 return -1; 2231 } 2232 return ancount; 2233 } 2234 2235 /* 2236 * Formulate a normal query, send, and retrieve answer in supplied buffer. 2237 * Return the size of the response on success, -1 on error. 2238 * If enabled, implement search rules until answer or unrecoverable failure 2239 * is detected. Error code, if any, is left in h_errno. 2240 */ 2241 static int 2242 res_searchN(const char *name, struct res_target *target, res_state res) 2243 { 2244 const char *cp, * const *domain; 2245 HEADER *hp; 2246 u_int dots; 2247 int trailing_dot, ret, saved_herrno; 2248 int got_nodata = 0, got_servfail = 0, tried_as_is = 0; 2249 2250 assert(name != NULL); 2251 assert(target != NULL); 2252 2253 hp = (HEADER *)(void *)target->answer; /*XXX*/ 2254 2255 errno = 0; 2256 h_errno = HOST_NOT_FOUND; /* default, if we never query */ 2257 dots = 0; 2258 for (cp = name; *cp; cp++) 2259 dots += (*cp == '.'); 2260 trailing_dot = 0; 2261 if (cp > name && *--cp == '.') 2262 trailing_dot++; 2263 2264 2265 //fprintf(stderr, "res_searchN() name = '%s'\n", name); 2266 2267 /* 2268 * if there aren't any dots, it could be a user-level alias 2269 */ 2270 if (!dots && (cp = __hostalias(name)) != NULL) { 2271 ret = res_queryN(cp, target, res); 2272 return ret; 2273 } 2274 2275 /* 2276 * If there are dots in the name already, let's just give it a try 2277 * 'as is'. The threshold can be set with the "ndots" option. 2278 */ 2279 saved_herrno = -1; 2280 if (dots >= res->ndots) { 2281 ret = res_querydomainN(name, NULL, target, res); 2282 if (ret > 0) 2283 return (ret); 2284 saved_herrno = h_errno; 2285 tried_as_is++; 2286 } 2287 2288 /* 2289 * We do at least one level of search if 2290 * - there is no dot and RES_DEFNAME is set, or 2291 * - there is at least one dot, there is no trailing dot, 2292 * and RES_DNSRCH is set. 2293 */ 2294 if ((!dots && (res->options & RES_DEFNAMES)) || 2295 (dots && !trailing_dot && (res->options & RES_DNSRCH))) { 2296 int done = 0; 2297 2298 /* Unfortunately we need to set stuff up before 2299 * the domain stuff is tried. Will have a better 2300 * fix after thread pools are used. 2301 */ 2302 _resolv_populate_res_for_net(res); 2303 2304 for (domain = (const char * const *)res->dnsrch; 2305 *domain && !done; 2306 domain++) { 2307 2308 ret = res_querydomainN(name, *domain, target, res); 2309 if (ret > 0) 2310 return ret; 2311 2312 /* 2313 * If no server present, give up. 2314 * If name isn't found in this domain, 2315 * keep trying higher domains in the search list 2316 * (if that's enabled). 2317 * On a NO_DATA error, keep trying, otherwise 2318 * a wildcard entry of another type could keep us 2319 * from finding this entry higher in the domain. 2320 * If we get some other error (negative answer or 2321 * server failure), then stop searching up, 2322 * but try the input name below in case it's 2323 * fully-qualified. 2324 */ 2325 if (errno == ECONNREFUSED) { 2326 h_errno = TRY_AGAIN; 2327 return -1; 2328 } 2329 2330 switch (h_errno) { 2331 case NO_DATA: 2332 got_nodata++; 2333 /* FALLTHROUGH */ 2334 case HOST_NOT_FOUND: 2335 /* keep trying */ 2336 break; 2337 case TRY_AGAIN: 2338 if (hp->rcode == SERVFAIL) { 2339 /* try next search element, if any */ 2340 got_servfail++; 2341 break; 2342 } 2343 /* FALLTHROUGH */ 2344 default: 2345 /* anything else implies that we're done */ 2346 done++; 2347 } 2348 /* 2349 * if we got here for some reason other than DNSRCH, 2350 * we only wanted one iteration of the loop, so stop. 2351 */ 2352 if (!(res->options & RES_DNSRCH)) 2353 done++; 2354 } 2355 } 2356 2357 /* 2358 * if we have not already tried the name "as is", do that now. 2359 * note that we do this regardless of how many dots were in the 2360 * name or whether it ends with a dot. 2361 */ 2362 if (!tried_as_is) { 2363 ret = res_querydomainN(name, NULL, target, res); 2364 if (ret > 0) 2365 return ret; 2366 } 2367 2368 /* 2369 * if we got here, we didn't satisfy the search. 2370 * if we did an initial full query, return that query's h_errno 2371 * (note that we wouldn't be here if that query had succeeded). 2372 * else if we ever got a nodata, send that back as the reason. 2373 * else send back meaningless h_errno, that being the one from 2374 * the last DNSRCH we did. 2375 */ 2376 if (saved_herrno != -1) 2377 h_errno = saved_herrno; 2378 else if (got_nodata) 2379 h_errno = NO_DATA; 2380 else if (got_servfail) 2381 h_errno = TRY_AGAIN; 2382 return -1; 2383 } 2384 2385 /* 2386 * Perform a call on res_query on the concatenation of name and domain, 2387 * removing a trailing dot from name if domain is NULL. 2388 */ 2389 static int 2390 res_querydomainN(const char *name, const char *domain, 2391 struct res_target *target, res_state res) 2392 { 2393 char nbuf[MAXDNAME]; 2394 const char *longname = nbuf; 2395 size_t n, d; 2396 2397 assert(name != NULL); 2398 /* XXX: target may be NULL??? */ 2399 2400 #ifdef DEBUG 2401 if (res->options & RES_DEBUG) 2402 printf(";; res_querydomain(%s, %s)\n", 2403 name, domain?domain:"<Nil>"); 2404 #endif 2405 if (domain == NULL) { 2406 /* 2407 * Check for trailing '.'; 2408 * copy without '.' if present. 2409 */ 2410 n = strlen(name); 2411 if (n + 1 > sizeof(nbuf)) { 2412 h_errno = NO_RECOVERY; 2413 return -1; 2414 } 2415 if (n > 0 && name[--n] == '.') { 2416 strncpy(nbuf, name, n); 2417 nbuf[n] = '\0'; 2418 } else 2419 longname = name; 2420 } else { 2421 n = strlen(name); 2422 d = strlen(domain); 2423 if (n + 1 + d + 1 > sizeof(nbuf)) { 2424 h_errno = NO_RECOVERY; 2425 return -1; 2426 } 2427 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); 2428 } 2429 return res_queryN(longname, target, res); 2430 } 2431
