| 1 | /* |
| 2 | * Copyright (c) 1988, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 4. Neither the name of the University nor the names of its contributors |
| 14 | * may be used to endorse or promote products derived from this software |
| 15 | * without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | */ |
| 29 | |
| 30 | /* |
| 31 | * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
| 32 | * |
| 33 | * Permission to use, copy, modify, and distribute this software for any |
| 34 | * purpose with or without fee is hereby granted, provided that the above |
| 35 | * copyright notice and this permission notice appear in all copies, and that |
| 36 | * the name of Digital Equipment Corporation not be used in advertising or |
| 37 | * publicity pertaining to distribution of the document or software without |
| 38 | * specific, written prior permission. |
| 39 | * |
| 40 | * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
| 41 | * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES |
| 42 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT |
| 43 | * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
| 44 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
| 45 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
| 46 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
| 47 | * SOFTWARE. |
| 48 | */ |
| 49 | |
| 50 | /* |
| 51 | * Portions Copyright (c) 1996-1999 by Internet Software Consortium. |
| 52 | * |
| 53 | * Permission to use, copy, modify, and distribute this software for any |
| 54 | * purpose with or without fee is hereby granted, provided that the above |
| 55 | * copyright notice and this permission notice appear in all copies. |
| 56 | * |
| 57 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS |
| 58 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES |
| 59 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE |
| 60 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
| 61 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
| 62 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
| 63 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
| 64 | * SOFTWARE. |
| 65 | */ |
| 66 | |
| 67 | #include <assert.h> |
| 68 | #include <sys/types.h> |
| 69 | #include <sys/param.h> |
| 70 | #include <netinet/in.h> |
| 71 | #include <arpa/inet.h> |
| 72 | #include <arpa/nameser.h> |
| 73 | #include <ctype.h> |
| 74 | #include <errno.h> |
| 75 | #include <netdb.h> |
| 76 | #include <resolv.h> |
| 77 | #include <resolv/resolv-internal.h> |
| 78 | #include <resolv/resolv_context.h> |
| 79 | #include <stdio.h> |
| 80 | #include <stdlib.h> |
| 81 | #include <string.h> |
| 82 | #include <shlib-compat.h> |
| 83 | |
| 84 | #if PACKETSZ > 65536 |
| 85 | #define MAXPACKET PACKETSZ |
| 86 | #else |
| 87 | #define MAXPACKET 65536 |
| 88 | #endif |
| 89 | |
| 90 | #define QUERYSIZE (HFIXEDSZ + QFIXEDSZ + MAXCDNAME + 1) |
| 91 | |
| 92 | static int |
| 93 | __res_context_querydomain (struct resolv_context *, |
| 94 | const char *name, const char *domain, |
| 95 | int class, int type, unsigned char *answer, int anslen, |
| 96 | unsigned char **answerp, unsigned char **answerp2, int *nanswerp2, |
| 97 | int *resplen2, int *answerp2_malloced); |
| 98 | |
| 99 | /* Formulate a normal query, send, and await answer. Returned answer |
| 100 | is placed in supplied buffer ANSWER. Perform preliminary check of |
| 101 | answer, returning success only if no error is indicated and the |
| 102 | answer count is nonzero. Return the size of the response on |
| 103 | success, -1 on error. Error number is left in h_errno. |
| 104 | |
| 105 | Caller must parse answer and determine whether it answers the |
| 106 | question. */ |
| 107 | int |
| 108 | __res_context_query (struct resolv_context *ctx, const char *name, |
| 109 | int class, int type, |
| 110 | unsigned char *answer, int anslen, |
| 111 | unsigned char **answerp, unsigned char **answerp2, |
| 112 | int *nanswerp2, int *resplen2, int *answerp2_malloced) |
| 113 | { |
| 114 | struct __res_state *statp = ctx->resp; |
| 115 | HEADER *hp = (HEADER *) answer; |
| 116 | HEADER *hp2; |
| 117 | int n, use_malloc = 0; |
| 118 | |
| 119 | size_t bufsize = (type == T_QUERY_A_AND_AAAA ? 2 : 1) * QUERYSIZE; |
| 120 | u_char *buf = alloca (bufsize); |
| 121 | u_char *query1 = buf; |
| 122 | int nquery1 = -1; |
| 123 | u_char *query2 = NULL; |
| 124 | int nquery2 = 0; |
| 125 | |
| 126 | again: |
| 127 | hp->rcode = NOERROR; /* default */ |
| 128 | |
| 129 | if (type == T_QUERY_A_AND_AAAA) |
| 130 | { |
| 131 | n = __res_context_mkquery (ctx, QUERY, name, class, T_A, NULL, |
| 132 | query1, bufsize); |
| 133 | if (n > 0) |
| 134 | { |
| 135 | if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) |
| 136 | { |
| 137 | /* Use RESOLV_EDNS_BUFFER_SIZE because the receive |
| 138 | buffer can be reallocated. */ |
| 139 | n = __res_nopt (ctx, n, query1, bufsize, |
| 140 | RESOLV_EDNS_BUFFER_SIZE); |
| 141 | if (n < 0) |
| 142 | goto unspec_nomem; |
| 143 | } |
| 144 | |
| 145 | nquery1 = n; |
| 146 | /* Align the buffer. */ |
| 147 | int npad = ((nquery1 + __alignof__ (HEADER) - 1) |
| 148 | & ~(__alignof__ (HEADER) - 1)) - nquery1; |
| 149 | if (n > bufsize - npad) |
| 150 | { |
| 151 | n = -1; |
| 152 | goto unspec_nomem; |
| 153 | } |
| 154 | int nused = n + npad; |
| 155 | query2 = buf + nused; |
| 156 | n = __res_context_mkquery (ctx, QUERY, name, class, T_AAAA, |
| 157 | NULL, query2, bufsize - nused); |
| 158 | if (n > 0 |
| 159 | && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) |
| 160 | /* Use RESOLV_EDNS_BUFFER_SIZE because the receive |
| 161 | buffer can be reallocated. */ |
| 162 | n = __res_nopt (ctx, n, query2, bufsize, |
| 163 | RESOLV_EDNS_BUFFER_SIZE); |
| 164 | nquery2 = n; |
| 165 | } |
| 166 | |
| 167 | unspec_nomem:; |
| 168 | } |
| 169 | else |
| 170 | { |
| 171 | n = __res_context_mkquery (ctx, QUERY, name, class, type, NULL, |
| 172 | query1, bufsize); |
| 173 | |
| 174 | if (n > 0 |
| 175 | && (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) |
| 176 | { |
| 177 | /* Use RESOLV_EDNS_BUFFER_SIZE if the receive buffer |
| 178 | can be reallocated. */ |
| 179 | size_t advertise; |
| 180 | if (answerp == NULL) |
| 181 | advertise = anslen; |
| 182 | else |
| 183 | advertise = RESOLV_EDNS_BUFFER_SIZE; |
| 184 | n = __res_nopt (ctx, n, query1, bufsize, advertise); |
| 185 | } |
| 186 | |
| 187 | nquery1 = n; |
| 188 | } |
| 189 | |
| 190 | if (__glibc_unlikely (n <= 0) && !use_malloc) { |
| 191 | /* Retry just in case res_nmkquery failed because of too |
| 192 | short buffer. Shouldn't happen. */ |
| 193 | bufsize = (type == T_QUERY_A_AND_AAAA ? 2 : 1) * MAXPACKET; |
| 194 | buf = malloc (bufsize); |
| 195 | if (buf != NULL) { |
| 196 | query1 = buf; |
| 197 | use_malloc = 1; |
| 198 | goto again; |
| 199 | } |
| 200 | } |
| 201 | if (__glibc_unlikely (n <= 0)) { |
| 202 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
| 203 | if (use_malloc) |
| 204 | free (buf); |
| 205 | return (n); |
| 206 | } |
| 207 | assert (answerp == NULL || (void *) *answerp == (void *) answer); |
| 208 | n = __res_context_send (ctx, query1, nquery1, query2, nquery2, answer, |
| 209 | anslen, answerp, answerp2, nanswerp2, resplen2, |
| 210 | answerp2_malloced); |
| 211 | if (use_malloc) |
| 212 | free (buf); |
| 213 | if (n < 0) { |
| 214 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
| 215 | return (n); |
| 216 | } |
| 217 | |
| 218 | if (answerp != NULL) |
| 219 | /* __res_context_send might have reallocated the buffer. */ |
| 220 | hp = (HEADER *) *answerp; |
| 221 | |
| 222 | /* We simplify the following tests by assigning HP to HP2 or |
| 223 | vice versa. It is easy to verify that this is the same as |
| 224 | ignoring all tests of HP or HP2. */ |
| 225 | if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER)) |
| 226 | { |
| 227 | hp2 = hp; |
| 228 | } |
| 229 | else |
| 230 | { |
| 231 | hp2 = (HEADER *) *answerp2; |
| 232 | if (n < (int) sizeof (HEADER)) |
| 233 | { |
| 234 | hp = hp2; |
| 235 | } |
| 236 | } |
| 237 | |
| 238 | /* Make sure both hp and hp2 are defined */ |
| 239 | assert((hp != NULL) && (hp2 != NULL)); |
| 240 | |
| 241 | if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0) |
| 242 | && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) { |
| 243 | switch (hp->rcode == NOERROR ? hp2->rcode : hp->rcode) { |
| 244 | case NXDOMAIN: |
| 245 | if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0) |
| 246 | || (hp2->rcode == NOERROR |
| 247 | && ntohs (hp2->ancount) != 0)) |
| 248 | goto success; |
| 249 | RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); |
| 250 | break; |
| 251 | case SERVFAIL: |
| 252 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
| 253 | break; |
| 254 | case NOERROR: |
| 255 | if (ntohs (hp->ancount) != 0 |
| 256 | || ntohs (hp2->ancount) != 0) |
| 257 | goto success; |
| 258 | RES_SET_H_ERRNO(statp, NO_DATA); |
| 259 | break; |
| 260 | case FORMERR: |
| 261 | case NOTIMP: |
| 262 | /* Servers must not reply to AAAA queries with |
| 263 | NOTIMP etc but some of them do. */ |
| 264 | if ((hp->rcode == NOERROR && ntohs (hp->ancount) != 0) |
| 265 | || (hp2->rcode == NOERROR |
| 266 | && ntohs (hp2->ancount) != 0)) |
| 267 | goto success; |
| 268 | /* FALLTHROUGH */ |
| 269 | case REFUSED: |
| 270 | default: |
| 271 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
| 272 | break; |
| 273 | } |
| 274 | return (-1); |
| 275 | } |
| 276 | success: |
| 277 | return (n); |
| 278 | } |
| 279 | libc_hidden_def (__res_context_query) |
| 280 | |
| 281 | /* Common part of res_nquery and res_query. */ |
| 282 | static int |
| 283 | context_query_common (struct resolv_context *ctx, |
| 284 | const char *name, int class, int type, |
| 285 | unsigned char *answer, int anslen) |
| 286 | { |
| 287 | if (ctx == NULL) |
| 288 | { |
| 289 | RES_SET_H_ERRNO (&_res, NETDB_INTERNAL); |
| 290 | return -1; |
| 291 | } |
| 292 | int result = __res_context_query (ctx, name, class, type, answer, anslen, |
| 293 | NULL, NULL, NULL, NULL, NULL); |
| 294 | __resolv_context_put (ctx); |
| 295 | return result; |
| 296 | } |
| 297 | |
| 298 | int |
| 299 | ___res_nquery (res_state statp, |
| 300 | const char *name, /* Domain name. */ |
| 301 | int class, int type, /* Class and type of query. */ |
| 302 | unsigned char *answer, /* Buffer to put answer. */ |
| 303 | int anslen) /* Size of answer buffer. */ |
| 304 | { |
| 305 | return context_query_common |
| 306 | (__resolv_context_get_override (statp), name, class, type, answer, anslen); |
| 307 | } |
| 308 | versioned_symbol (libc, ___res_nquery, res_nquery, GLIBC_2_34); |
| 309 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_2, GLIBC_2_34) |
| 310 | compat_symbol (libresolv, ___res_nquery, __res_nquery, GLIBC_2_2); |
| 311 | #endif |
| 312 | |
| 313 | int |
| 314 | ___res_query (const char *name, int class, int type, |
| 315 | unsigned char *answer, int anslen) |
| 316 | { |
| 317 | return context_query_common |
| 318 | (__resolv_context_get (), name, class, type, answer, anslen); |
| 319 | } |
| 320 | versioned_symbol (libc, ___res_query, res_query, GLIBC_2_34); |
| 321 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_2) |
| 322 | compat_symbol (libresolv, ___res_query, res_query, GLIBC_2_0); |
| 323 | #endif |
| 324 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_2, GLIBC_2_34) |
| 325 | compat_symbol (libresolv, ___res_query, __res_query, GLIBC_2_2); |
| 326 | #endif |
| 327 | |
| 328 | /* Formulate a normal query, send, and retrieve answer in supplied |
| 329 | buffer. Return the size of the response on success, -1 on error. |
| 330 | If enabled, implement search rules until answer or unrecoverable |
| 331 | failure is detected. Error code, if any, is left in h_errno. */ |
| 332 | int |
| 333 | __res_context_search (struct resolv_context *ctx, |
| 334 | const char *name, int class, int type, |
| 335 | unsigned char *answer, int anslen, |
| 336 | unsigned char **answerp, unsigned char **answerp2, |
| 337 | int *nanswerp2, int *resplen2, int *answerp2_malloced) |
| 338 | { |
| 339 | struct __res_state *statp = ctx->resp; |
| 340 | const char *cp; |
| 341 | HEADER *hp = (HEADER *) answer; |
| 342 | char tmp[NS_MAXDNAME]; |
| 343 | u_int dots; |
| 344 | int trailing_dot, ret, saved_herrno; |
| 345 | int got_nodata = 0, got_servfail = 0, root_on_list = 0; |
| 346 | int tried_as_is = 0; |
| 347 | int searched = 0; |
| 348 | |
| 349 | __set_errno (0); |
| 350 | RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); /* True if we never query. */ |
| 351 | |
| 352 | dots = 0; |
| 353 | for (cp = name; *cp != '\0'; cp++) |
| 354 | dots += (*cp == '.'); |
| 355 | trailing_dot = 0; |
| 356 | if (cp > name && *--cp == '.') |
| 357 | trailing_dot++; |
| 358 | |
| 359 | /* If there aren't any dots, it could be a user-level alias. */ |
| 360 | if (!dots && (cp = __res_context_hostalias |
| 361 | (ctx, name, tmp, sizeof tmp))!= NULL) |
| 362 | return __res_context_query (ctx, cp, class, type, answer, |
| 363 | anslen, answerp, answerp2, |
| 364 | nanswerp2, resplen2, answerp2_malloced); |
| 365 | |
| 366 | /* |
| 367 | * If there are enough dots in the name, let's just give it a |
| 368 | * try 'as is'. The threshold can be set with the "ndots" option. |
| 369 | * Also, query 'as is', if there is a trailing dot in the name. |
| 370 | */ |
| 371 | saved_herrno = -1; |
| 372 | if (dots >= statp->ndots || trailing_dot) { |
| 373 | ret = __res_context_querydomain (ctx, name, NULL, class, type, |
| 374 | answer, anslen, answerp, |
| 375 | answerp2, nanswerp2, resplen2, |
| 376 | answerp2_malloced); |
| 377 | if (ret > 0 || trailing_dot |
| 378 | /* If the second response is valid then we use that. */ |
| 379 | || (ret == 0 && resplen2 != NULL && *resplen2 > 0)) |
| 380 | return (ret); |
| 381 | saved_herrno = h_errno; |
| 382 | tried_as_is++; |
| 383 | if (answerp && *answerp != answer) { |
| 384 | answer = *answerp; |
| 385 | anslen = MAXPACKET; |
| 386 | } |
| 387 | if (answerp2 && *answerp2_malloced) |
| 388 | { |
| 389 | free (*answerp2); |
| 390 | *answerp2 = NULL; |
| 391 | *nanswerp2 = 0; |
| 392 | *answerp2_malloced = 0; |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | /* |
| 397 | * We do at least one level of search if |
| 398 | * - there is no dot and RES_DEFNAME is set, or |
| 399 | * - there is at least one dot, there is no trailing dot, |
| 400 | * and RES_DNSRCH is set. |
| 401 | */ |
| 402 | if ((!dots && (statp->options & RES_DEFNAMES) != 0) || |
| 403 | (dots && !trailing_dot && (statp->options & RES_DNSRCH) != 0)) { |
| 404 | int done = 0; |
| 405 | |
| 406 | for (size_t domain_index = 0; !done; ++domain_index) { |
| 407 | const char *dname = __resolv_context_search_list |
| 408 | (ctx, domain_index); |
| 409 | if (dname == NULL) |
| 410 | break; |
| 411 | searched = 1; |
| 412 | |
| 413 | /* __res_context_querydoman concatenates name |
| 414 | with dname with a "." in between. If we |
| 415 | pass it in dname the "." we got from the |
| 416 | configured default search path, we'll end |
| 417 | up with "name..", which won't resolve. |
| 418 | OTOH, passing it "" will result in "name.", |
| 419 | which has the intended effect for both |
| 420 | possible representations of the root |
| 421 | domain. */ |
| 422 | if (dname[0] == '.') |
| 423 | dname++; |
| 424 | if (dname[0] == '\0') |
| 425 | root_on_list++; |
| 426 | |
| 427 | ret = __res_context_querydomain |
| 428 | (ctx, name, dname, class, type, |
| 429 | answer, anslen, answerp, answerp2, nanswerp2, |
| 430 | resplen2, answerp2_malloced); |
| 431 | if (ret > 0 || (ret == 0 && resplen2 != NULL |
| 432 | && *resplen2 > 0)) |
| 433 | return (ret); |
| 434 | |
| 435 | if (answerp && *answerp != answer) { |
| 436 | answer = *answerp; |
| 437 | anslen = MAXPACKET; |
| 438 | } |
| 439 | if (answerp2 && *answerp2_malloced) |
| 440 | { |
| 441 | free (*answerp2); |
| 442 | *answerp2 = NULL; |
| 443 | *nanswerp2 = 0; |
| 444 | *answerp2_malloced = 0; |
| 445 | } |
| 446 | |
| 447 | /* |
| 448 | * If no server present, give up. |
| 449 | * If name isn't found in this domain, |
| 450 | * keep trying higher domains in the search list |
| 451 | * (if that's enabled). |
| 452 | * On a NO_DATA error, keep trying, otherwise |
| 453 | * a wildcard entry of another type could keep us |
| 454 | * from finding this entry higher in the domain. |
| 455 | * If we get some other error (negative answer or |
| 456 | * server failure), then stop searching up, |
| 457 | * but try the input name below in case it's |
| 458 | * fully-qualified. |
| 459 | */ |
| 460 | if (errno == ECONNREFUSED) { |
| 461 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
| 462 | return (-1); |
| 463 | } |
| 464 | |
| 465 | switch (statp->res_h_errno) { |
| 466 | case NO_DATA: |
| 467 | got_nodata++; |
| 468 | /* FALLTHROUGH */ |
| 469 | case HOST_NOT_FOUND: |
| 470 | /* keep trying */ |
| 471 | break; |
| 472 | case TRY_AGAIN: |
| 473 | if (hp->rcode == SERVFAIL) { |
| 474 | /* try next search element, if any */ |
| 475 | got_servfail++; |
| 476 | break; |
| 477 | } |
| 478 | /* FALLTHROUGH */ |
| 479 | default: |
| 480 | /* anything else implies that we're done */ |
| 481 | done++; |
| 482 | } |
| 483 | |
| 484 | /* if we got here for some reason other than DNSRCH, |
| 485 | * we only wanted one iteration of the loop, so stop. |
| 486 | */ |
| 487 | if ((statp->options & RES_DNSRCH) == 0) |
| 488 | done++; |
| 489 | } |
| 490 | } |
| 491 | |
| 492 | /* |
| 493 | * If the query has not already been tried as is then try it |
| 494 | * unless RES_NOTLDQUERY is set and there were no dots. |
| 495 | */ |
| 496 | if ((dots || !searched || (statp->options & RES_NOTLDQUERY) == 0) |
| 497 | && !(tried_as_is || root_on_list)) { |
| 498 | ret = __res_context_querydomain |
| 499 | (ctx, name, NULL, class, type, |
| 500 | answer, anslen, answerp, answerp2, nanswerp2, |
| 501 | resplen2, answerp2_malloced); |
| 502 | if (ret > 0 || (ret == 0 && resplen2 != NULL |
| 503 | && *resplen2 > 0)) |
| 504 | return (ret); |
| 505 | } |
| 506 | |
| 507 | /* if we got here, we didn't satisfy the search. |
| 508 | * if we did an initial full query, return that query's H_ERRNO |
| 509 | * (note that we wouldn't be here if that query had succeeded). |
| 510 | * else if we ever got a nodata, send that back as the reason. |
| 511 | * else send back meaningless H_ERRNO, that being the one from |
| 512 | * the last DNSRCH we did. |
| 513 | */ |
| 514 | if (answerp2 && *answerp2_malloced) |
| 515 | { |
| 516 | free (*answerp2); |
| 517 | *answerp2 = NULL; |
| 518 | *nanswerp2 = 0; |
| 519 | *answerp2_malloced = 0; |
| 520 | } |
| 521 | if (saved_herrno != -1) |
| 522 | RES_SET_H_ERRNO(statp, saved_herrno); |
| 523 | else if (got_nodata) |
| 524 | RES_SET_H_ERRNO(statp, NO_DATA); |
| 525 | else if (got_servfail) |
| 526 | RES_SET_H_ERRNO(statp, TRY_AGAIN); |
| 527 | return (-1); |
| 528 | } |
| 529 | libc_hidden_def (__res_context_search) |
| 530 | |
| 531 | /* Common part of res_nsearch and res_search. */ |
| 532 | static int |
| 533 | context_search_common (struct resolv_context *ctx, |
| 534 | const char *name, int class, int type, |
| 535 | unsigned char *answer, int anslen) |
| 536 | { |
| 537 | if (ctx == NULL) |
| 538 | { |
| 539 | RES_SET_H_ERRNO (&_res, NETDB_INTERNAL); |
| 540 | return -1; |
| 541 | } |
| 542 | int result = __res_context_search (ctx, name, class, type, answer, anslen, |
| 543 | NULL, NULL, NULL, NULL, NULL); |
| 544 | __resolv_context_put (ctx); |
| 545 | return result; |
| 546 | } |
| 547 | |
| 548 | int |
| 549 | ___res_nsearch (res_state statp, |
| 550 | const char *name, /* Domain name. */ |
| 551 | int class, int type, /* Class and type of query. */ |
| 552 | unsigned char *answer, /* Buffer to put answer. */ |
| 553 | int anslen) /* Size of answer. */ |
| 554 | { |
| 555 | return context_search_common |
| 556 | (__resolv_context_get_override (statp), name, class, type, answer, anslen); |
| 557 | } |
| 558 | versioned_symbol (libc, ___res_nsearch, res_nsearch, GLIBC_2_34); |
| 559 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_2, GLIBC_2_34) |
| 560 | compat_symbol (libresolv, ___res_nsearch, __res_nsearch, GLIBC_2_2); |
| 561 | #endif |
| 562 | |
| 563 | int |
| 564 | ___res_search (const char *name, int class, int type, |
| 565 | unsigned char *answer, int anslen) |
| 566 | { |
| 567 | return context_search_common |
| 568 | (__resolv_context_get (), name, class, type, answer, anslen); |
| 569 | } |
| 570 | versioned_symbol (libc, ___res_search, res_search, GLIBC_2_34); |
| 571 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_2) |
| 572 | compat_symbol (libresolv, ___res_search, res_search, GLIBC_2_0); |
| 573 | #endif |
| 574 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_2, GLIBC_2_34) |
| 575 | compat_symbol (libresolv, ___res_search, __res_search, GLIBC_2_2); |
| 576 | #endif |
| 577 | |
| 578 | /* Perform a call on res_query on the concatenation of name and |
| 579 | domain. */ |
| 580 | static int |
| 581 | __res_context_querydomain (struct resolv_context *ctx, |
| 582 | const char *name, const char *domain, |
| 583 | int class, int type, |
| 584 | unsigned char *answer, int anslen, |
| 585 | unsigned char **answerp, unsigned char **answerp2, |
| 586 | int *nanswerp2, int *resplen2, |
| 587 | int *answerp2_malloced) |
| 588 | { |
| 589 | struct __res_state *statp = ctx->resp; |
| 590 | char nbuf[MAXDNAME]; |
| 591 | const char *longname = nbuf; |
| 592 | size_t n, d; |
| 593 | |
| 594 | if (domain == NULL) { |
| 595 | n = strlen(name); |
| 596 | |
| 597 | /* Decrement N prior to checking it against MAXDNAME |
| 598 | so that we detect a wrap to SIZE_MAX and return |
| 599 | a reasonable error. */ |
| 600 | n--; |
| 601 | if (n >= MAXDNAME - 1) { |
| 602 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
| 603 | return (-1); |
| 604 | } |
| 605 | longname = name; |
| 606 | } else { |
| 607 | n = strlen(name); |
| 608 | d = strlen(domain); |
| 609 | if (n + d + 1 >= MAXDNAME) { |
| 610 | RES_SET_H_ERRNO(statp, NO_RECOVERY); |
| 611 | return (-1); |
| 612 | } |
| 613 | sprintf(nbuf, "%s.%s" , name, domain); |
| 614 | } |
| 615 | return __res_context_query (ctx, longname, class, type, answer, |
| 616 | anslen, answerp, answerp2, nanswerp2, |
| 617 | resplen2, answerp2_malloced); |
| 618 | } |
| 619 | |
| 620 | /* Common part of res_nquerydomain and res_querydomain. */ |
| 621 | static int |
| 622 | context_querydomain_common (struct resolv_context *ctx, |
| 623 | const char *name, const char *domain, |
| 624 | int class, int type, |
| 625 | unsigned char *answer, int anslen) |
| 626 | { |
| 627 | if (ctx == NULL) |
| 628 | { |
| 629 | RES_SET_H_ERRNO (&_res, NETDB_INTERNAL); |
| 630 | return -1; |
| 631 | } |
| 632 | int result = __res_context_querydomain (ctx, name, domain, class, type, |
| 633 | answer, anslen, |
| 634 | NULL, NULL, NULL, NULL, NULL); |
| 635 | __resolv_context_put (ctx); |
| 636 | return result; |
| 637 | } |
| 638 | |
| 639 | int |
| 640 | ___res_nquerydomain (res_state statp, |
| 641 | const char *name, |
| 642 | const char *domain, |
| 643 | int class, int type, /* Class and type of query. */ |
| 644 | unsigned char *answer, /* Buffer to put answer. */ |
| 645 | int anslen) /* Size of answer. */ |
| 646 | { |
| 647 | return context_querydomain_common |
| 648 | (__resolv_context_get_override (statp), |
| 649 | name, domain, class, type, answer, anslen); |
| 650 | } |
| 651 | versioned_symbol (libc, ___res_nquerydomain, res_nquerydomain, GLIBC_2_34); |
| 652 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_2, GLIBC_2_34) |
| 653 | compat_symbol (libresolv, ___res_nquerydomain, __res_nquerydomain, GLIBC_2_2); |
| 654 | #endif |
| 655 | |
| 656 | int |
| 657 | ___res_querydomain (const char *name, const char *domain, int class, int type, |
| 658 | unsigned char *answer, int anslen) |
| 659 | { |
| 660 | return context_querydomain_common |
| 661 | (__resolv_context_get (), name, domain, class, type, answer, anslen); |
| 662 | } |
| 663 | versioned_symbol (libc, ___res_querydomain, res_querydomain, GLIBC_2_34); |
| 664 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_2) |
| 665 | compat_symbol (libresolv, ___res_querydomain, res_querydomain, GLIBC_2_0); |
| 666 | #endif |
| 667 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_2, GLIBC_2_34) |
| 668 | compat_symbol (libresolv, ___res_querydomain, __res_querydomain, GLIBC_2_2); |
| 669 | #endif |
| 670 | |