xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copyright (C) 2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | /* |
| 19 | * Copyright (c) 1985, 1989, 1993 |
| 20 | * The Regents of the University of California. All rights reserved. |
| 21 | * |
| 22 | * Redistribution and use in source and binary forms, with or without |
| 23 | * modification, are permitted provided that the following conditions |
| 24 | * are met: |
| 25 | * 1. Redistributions of source code must retain the above copyright |
| 26 | * notice, this list of conditions and the following disclaimer. |
| 27 | * 2. Redistributions in binary form must reproduce the above copyright |
| 28 | * notice, this list of conditions and the following disclaimer in the |
| 29 | * documentation and/or other materials provided with the distribution. |
| 30 | * 4. Neither the name of the University nor the names of its contributors |
| 31 | * may be used to endorse or promote products derived from this software |
| 32 | * without specific prior written permission. |
| 33 | * |
| 34 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 35 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 36 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 37 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 38 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 39 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 40 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 41 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 42 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 43 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 44 | * SUCH DAMAGE. |
| 45 | */ |
| 46 | |
| 47 | /* |
| 48 | * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
| 49 | * |
| 50 | * Permission to use, copy, modify, and distribute this software for any |
| 51 | * purpose with or without fee is hereby granted, provided that the above |
| 52 | * copyright notice and this permission notice appear in all copies, and that |
| 53 | * the name of Digital Equipment Corporation not be used in advertising or |
| 54 | * publicity pertaining to distribution of the document or software without |
| 55 | * specific, written prior permission. |
| 56 | * |
| 57 | * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
| 58 | * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES |
| 59 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT |
| 60 | * CORPORATION 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 | /* |
| 68 | * Portions Copyright (c) 1996-1999 by Internet Software Consortium. |
| 69 | * |
| 70 | * Permission to use, copy, modify, and distribute this software for any |
| 71 | * purpose with or without fee is hereby granted, provided that the above |
| 72 | * copyright notice and this permission notice appear in all copies. |
| 73 | * |
| 74 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS |
| 75 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES |
| 76 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE |
| 77 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
| 78 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
| 79 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
| 80 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
| 81 | * SOFTWARE. |
| 82 | */ |
| 83 | |
| 84 | #if defined(LIBC_SCCS) && !defined(lint) |
| 85 | static const char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93"; |
| 86 | static const char rcsid[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixie Exp $"; |
| 87 | #endif /* LIBC_SCCS and not lint */ |
| 88 | |
| 89 | /* |
| 90 | * Send query to name server and wait for reply. |
| 91 | */ |
| 92 | |
| 93 | #include <assert.h> |
| 94 | #include <sys/types.h> |
| 95 | #include <sys/param.h> |
| 96 | #include <sys/time.h> |
| 97 | #include <sys/socket.h> |
| 98 | #include <sys/uio.h> |
| 99 | #include <sys/poll.h> |
| 100 | |
| 101 | #include <netinet/in.h> |
| 102 | #include <arpa/nameser.h> |
| 103 | #include <arpa/inet.h> |
| 104 | #include <sys/ioctl.h> |
| 105 | |
| 106 | #include <errno.h> |
| 107 | #include <fcntl.h> |
| 108 | #include <netdb.h> |
| 109 | #include <resolv.h> |
| 110 | #include <signal.h> |
| 111 | #include <stdio.h> |
| 112 | #include <stdlib.h> |
| 113 | #include <string.h> |
| 114 | #include <unistd.h> |
| 115 | #include <kernel-features.h> |
| 116 | #include <libc-internal.h> |
| 117 | |
| 118 | #if PACKETSZ > 65536 |
| 119 | #define MAXPACKET PACKETSZ |
| 120 | #else |
| 121 | #define MAXPACKET 65536 |
| 122 | #endif |
| 123 | |
| 124 | /* From ev_streams.c. */ |
| 125 | |
| 126 | static inline void |
| 127 | __attribute ((always_inline)) |
| 128 | evConsIovec(void *buf, size_t cnt, struct iovec *vec) { |
| 129 | memset(vec, 0xf5, sizeof (*vec)); |
| 130 | vec->iov_base = buf; |
| 131 | vec->iov_len = cnt; |
| 132 | } |
| 133 | |
| 134 | /* From ev_timers.c. */ |
| 135 | |
| 136 | #define BILLION 1000000000 |
| 137 | |
| 138 | static inline void |
| 139 | evConsTime(struct timespec *res, time_t sec, long nsec) { |
| 140 | res->tv_sec = sec; |
| 141 | res->tv_nsec = nsec; |
| 142 | } |
| 143 | |
| 144 | static inline void |
| 145 | evAddTime(struct timespec *res, const struct timespec *addend1, |
| 146 | const struct timespec *addend2) { |
| 147 | res->tv_sec = addend1->tv_sec + addend2->tv_sec; |
| 148 | res->tv_nsec = addend1->tv_nsec + addend2->tv_nsec; |
| 149 | if (res->tv_nsec >= BILLION) { |
| 150 | res->tv_sec++; |
| 151 | res->tv_nsec -= BILLION; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | static inline void |
| 156 | evSubTime(struct timespec *res, const struct timespec *minuend, |
| 157 | const struct timespec *subtrahend) { |
| 158 | res->tv_sec = minuend->tv_sec - subtrahend->tv_sec; |
| 159 | if (minuend->tv_nsec >= subtrahend->tv_nsec) |
| 160 | res->tv_nsec = minuend->tv_nsec - subtrahend->tv_nsec; |
| 161 | else { |
| 162 | res->tv_nsec = (BILLION |
| 163 | - subtrahend->tv_nsec + minuend->tv_nsec); |
| 164 | res->tv_sec--; |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | static int |
| 169 | evCmpTime(struct timespec a, struct timespec b) { |
| 170 | long x = a.tv_sec - b.tv_sec; |
| 171 | |
| 172 | if (x == 0L) |
| 173 | x = a.tv_nsec - b.tv_nsec; |
| 174 | return (x < 0L ? (-1) : x > 0L ? (1) : (0)); |
| 175 | } |
| 176 | |
| 177 | static void |
| 178 | evNowTime(struct timespec *res) { |
| 179 | struct timeval now; |
| 180 | |
| 181 | if (gettimeofday(&now, NULL) < 0) |
| 182 | evConsTime(res, 0, 0); |
| 183 | else |
| 184 | TIMEVAL_TO_TIMESPEC (&now, res); |
| 185 | } |
| 186 | |
| 187 | |
| 188 | /* Options. Leave them on. */ |
| 189 | /* #undef DEBUG */ |
| 190 | #include "res_debug.h" |
| 191 | |
| 192 | #define EXT(res) ((res)->_u._ext) |
| 193 | |
| 194 | /* Forward. */ |
| 195 | |
| 196 | static struct sockaddr *get_nsaddr (res_state, int); |
| 197 | static int send_vc(res_state, const u_char *, int, |
| 198 | const u_char *, int, |
| 199 | u_char **, int *, int *, int, u_char **, |
| 200 | u_char **, int *, int *, int *); |
| 201 | static int send_dg(res_state, const u_char *, int, |
| 202 | const u_char *, int, |
| 203 | u_char **, int *, int *, int, |
| 204 | int *, int *, u_char **, |
| 205 | u_char **, int *, int *, int *); |
| 206 | #ifdef DEBUG |
| 207 | static void Aerror(const res_state, FILE *, const char *, int, |
| 208 | const struct sockaddr *); |
| 209 | static void Perror(const res_state, FILE *, const char *, int); |
| 210 | #endif |
| 211 | static int sock_eq(struct sockaddr_in6 *, struct sockaddr_in6 *); |
| 212 | |
| 213 | /* Public. */ |
| 214 | |
| 215 | /* int |
| 216 | * res_isourserver(ina) |
| 217 | * looks up "ina" in _res.ns_addr_list[] |
| 218 | * returns: |
| 219 | * 0 : not found |
| 220 | * >0 : found |
| 221 | * author: |
| 222 | * paul vixie, 29may94 |
| 223 | */ |
| 224 | int |
| 225 | res_ourserver_p(const res_state statp, const struct sockaddr_in6 *inp) |
| 226 | { |
| 227 | int ns; |
| 228 | |
| 229 | if (inp->sin6_family == AF_INET) { |
| 230 | struct sockaddr_in *in4p = (struct sockaddr_in *) inp; |
| 231 | in_port_t port = in4p->sin_port; |
| 232 | in_addr_t addr = in4p->sin_addr.s_addr; |
| 233 | |
| 234 | for (ns = 0; ns < statp->nscount; ns++) { |
| 235 | const struct sockaddr_in *srv = |
| 236 | (struct sockaddr_in *) get_nsaddr (statp, ns); |
| 237 | |
| 238 | if ((srv->sin_family == AF_INET) && |
| 239 | (srv->sin_port == port) && |
| 240 | (srv->sin_addr.s_addr == INADDR_ANY || |
| 241 | srv->sin_addr.s_addr == addr)) |
| 242 | return (1); |
| 243 | } |
| 244 | } else if (inp->sin6_family == AF_INET6) { |
| 245 | for (ns = 0; ns < statp->nscount; ns++) { |
| 246 | const struct sockaddr_in6 *srv |
| 247 | = (struct sockaddr_in6 *) get_nsaddr (statp, ns); |
| 248 | if ((srv->sin6_family == AF_INET6) && |
| 249 | (srv->sin6_port == inp->sin6_port) && |
| 250 | !(memcmp(&srv->sin6_addr, &in6addr_any, |
| 251 | sizeof (struct in6_addr)) && |
| 252 | memcmp(&srv->sin6_addr, &inp->sin6_addr, |
| 253 | sizeof (struct in6_addr)))) |
| 254 | return (1); |
| 255 | } |
| 256 | } |
| 257 | return (0); |
| 258 | } |
| 259 | |
| 260 | /* int |
| 261 | * res_nameinquery(name, type, class, buf, eom) |
| 262 | * look for (name,type,class) in the query section of packet (buf,eom) |
| 263 | * requires: |
| 264 | * buf + HFIXEDSZ <= eom |
| 265 | * returns: |
| 266 | * -1 : format error |
| 267 | * 0 : not found |
| 268 | * >0 : found |
| 269 | * author: |
| 270 | * paul vixie, 29may94 |
| 271 | */ |
| 272 | int |
| 273 | res_nameinquery(const char *name, int type, int class, |
| 274 | const u_char *buf, const u_char *eom) |
| 275 | { |
| 276 | const u_char *cp = buf + HFIXEDSZ; |
| 277 | int qdcount = ntohs(((HEADER*)buf)->qdcount); |
| 278 | |
| 279 | while (qdcount-- > 0) { |
| 280 | char tname[MAXDNAME+1]; |
| 281 | int n, ttype, tclass; |
| 282 | |
| 283 | n = dn_expand(buf, eom, cp, tname, sizeof tname); |
| 284 | if (n < 0) |
| 285 | return (-1); |
| 286 | cp += n; |
| 287 | if (cp + 2 * INT16SZ > eom) |
| 288 | return (-1); |
| 289 | NS_GET16(ttype, cp); |
| 290 | NS_GET16(tclass, cp); |
| 291 | if (ttype == type && tclass == class && |
| 292 | ns_samename(tname, name) == 1) |
| 293 | return (1); |
| 294 | } |
| 295 | return (0); |
| 296 | } |
| 297 | libresolv_hidden_def (res_nameinquery) |
| 298 | |
| 299 | /* int |
| 300 | * res_queriesmatch(buf1, eom1, buf2, eom2) |
| 301 | * is there a 1:1 mapping of (name,type,class) |
| 302 | * in (buf1,eom1) and (buf2,eom2)? |
| 303 | * returns: |
| 304 | * -1 : format error |
| 305 | * 0 : not a 1:1 mapping |
| 306 | * >0 : is a 1:1 mapping |
| 307 | * author: |
| 308 | * paul vixie, 29may94 |
| 309 | */ |
| 310 | int |
| 311 | res_queriesmatch(const u_char *buf1, const u_char *eom1, |
| 312 | const u_char *buf2, const u_char *eom2) |
| 313 | { |
| 314 | if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2) |
| 315 | return (-1); |
| 316 | |
| 317 | /* |
| 318 | * Only header section present in replies to |
| 319 | * dynamic update packets. |
| 320 | */ |
| 321 | if ((((HEADER *)buf1)->opcode == ns_o_update) && |
| 322 | (((HEADER *)buf2)->opcode == ns_o_update)) |
| 323 | return (1); |
| 324 | |
| 325 | /* Note that we initially do not convert QDCOUNT to the host byte |
| 326 | order. We can compare it with the second buffer's QDCOUNT |
| 327 | value without doing this. */ |
| 328 | int qdcount = ((HEADER*)buf1)->qdcount; |
| 329 | if (qdcount != ((HEADER*)buf2)->qdcount) |
| 330 | return (0); |
| 331 | |
| 332 | qdcount = htons (qdcount); |
| 333 | const u_char *cp = buf1 + HFIXEDSZ; |
| 334 | |
| 335 | while (qdcount-- > 0) { |
| 336 | char tname[MAXDNAME+1]; |
| 337 | int n, ttype, tclass; |
| 338 | |
| 339 | n = dn_expand(buf1, eom1, cp, tname, sizeof tname); |
| 340 | if (n < 0) |
| 341 | return (-1); |
| 342 | cp += n; |
| 343 | if (cp + 2 * INT16SZ > eom1) |
| 344 | return (-1); |
| 345 | NS_GET16(ttype, cp); |
| 346 | NS_GET16(tclass, cp); |
| 347 | if (!res_nameinquery(tname, ttype, tclass, buf2, eom2)) |
| 348 | return (0); |
| 349 | } |
| 350 | return (1); |
| 351 | } |
| 352 | libresolv_hidden_def (res_queriesmatch) |
| 353 | |
| 354 | int |
| 355 | __libc_res_nsend(res_state statp, const u_char *buf, int buflen, |
| 356 | const u_char *buf2, int buflen2, |
| 357 | u_char *ans, int anssiz, u_char **ansp, u_char **ansp2, |
| 358 | int *nansp2, int *resplen2, int *ansp2_malloced) |
| 359 | { |
| 360 | int gotsomewhere, terrno, try, v_circuit, resplen, ns, n; |
| 361 | |
| 362 | if (statp->nscount == 0) { |
| 363 | __set_errno (ESRCH); |
| 364 | return (-1); |
| 365 | } |
| 366 | |
| 367 | if (anssiz < (buf2 == NULL ? 1 : 2) * HFIXEDSZ) { |
| 368 | __set_errno (EINVAL); |
| 369 | return (-1); |
| 370 | } |
| 371 | |
| 372 | #ifdef USE_HOOKS |
| 373 | if (__glibc_unlikely (statp->qhook || statp->rhook)) { |
| 374 | if (anssiz < MAXPACKET && ansp) { |
| 375 | /* Always allocate MAXPACKET, callers expect |
| 376 | this specific size. */ |
| 377 | u_char *buf = malloc (MAXPACKET); |
| 378 | if (buf == NULL) |
| 379 | return (-1); |
| 380 | memcpy (buf, ans, HFIXEDSZ); |
| 381 | *ansp = buf; |
| 382 | ans = buf; |
| 383 | anssiz = MAXPACKET; |
| 384 | } |
| 385 | } |
| 386 | #endif |
| 387 | |
| 388 | DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY), |
| 389 | (stdout, ";; res_send()\n"), buf, buflen); |
| 390 | v_circuit = ((statp->options & RES_USEVC) |
| 391 | || buflen > PACKETSZ |
| 392 | || buflen2 > PACKETSZ); |
| 393 | gotsomewhere = 0; |
| 394 | terrno = ETIMEDOUT; |
| 395 | |
| 396 | /* |
| 397 | * If the ns_addr_list in the resolver context has changed, then |
| 398 | * invalidate our cached copy and the associated timing data. |
| 399 | */ |
| 400 | if (EXT(statp).nscount != 0) { |
| 401 | int needclose = 0; |
| 402 | |
| 403 | if (EXT(statp).nscount != statp->nscount) |
| 404 | needclose++; |
| 405 | else |
| 406 | for (ns = 0; ns < statp->nscount; ns++) { |
| 407 | if (statp->nsaddr_list[ns].sin_family != 0 |
| 408 | && !sock_eq((struct sockaddr_in6 *) |
| 409 | &statp->nsaddr_list[ns], |
| 410 | EXT(statp).nsaddrs[ns])) |
| 411 | { |
| 412 | needclose++; |
| 413 | break; |
| 414 | } |
| 415 | } |
| 416 | if (needclose) { |
| 417 | __res_iclose(statp, false); |
| 418 | EXT(statp).nscount = 0; |
| 419 | } |
| 420 | } |
| 421 | |
| 422 | /* |
| 423 | * Maybe initialize our private copy of the ns_addr_list. |
| 424 | */ |
| 425 | if (EXT(statp).nscount == 0) { |
| 426 | for (ns = 0; ns < statp->nscount; ns++) { |
| 427 | EXT(statp).nssocks[ns] = -1; |
| 428 | if (statp->nsaddr_list[ns].sin_family == 0) |
| 429 | continue; |
| 430 | if (EXT(statp).nsaddrs[ns] == NULL) |
| 431 | EXT(statp).nsaddrs[ns] = |
| 432 | malloc(sizeof (struct sockaddr_in6)); |
| 433 | if (EXT(statp).nsaddrs[ns] != NULL) |
| 434 | memset (mempcpy(EXT(statp).nsaddrs[ns], |
| 435 | &statp->nsaddr_list[ns], |
| 436 | sizeof (struct sockaddr_in)), |
| 437 | '\0', |
| 438 | sizeof (struct sockaddr_in6) |
| 439 | - sizeof (struct sockaddr_in)); |
| 440 | } |
| 441 | EXT(statp).nscount = statp->nscount; |
| 442 | } |
| 443 | |
| 444 | /* |
| 445 | * Some resolvers want to even out the load on their nameservers. |
| 446 | * Note that RES_BLAST overrides RES_ROTATE. |
| 447 | */ |
| 448 | if (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0) && |
| 449 | (statp->options & RES_BLAST) == 0) { |
| 450 | struct sockaddr_in ina; |
| 451 | struct sockaddr_in6 *inp; |
| 452 | int lastns = statp->nscount - 1; |
| 453 | int fd; |
| 454 | |
| 455 | inp = EXT(statp).nsaddrs[0]; |
| 456 | ina = statp->nsaddr_list[0]; |
| 457 | fd = EXT(statp).nssocks[0]; |
| 458 | for (ns = 0; ns < lastns; ns++) { |
| 459 | EXT(statp).nsaddrs[ns] = EXT(statp).nsaddrs[ns + 1]; |
| 460 | statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1]; |
| 461 | EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1]; |
| 462 | } |
| 463 | EXT(statp).nsaddrs[lastns] = inp; |
| 464 | statp->nsaddr_list[lastns] = ina; |
| 465 | EXT(statp).nssocks[lastns] = fd; |
| 466 | } |
| 467 | |
| 468 | /* |
| 469 | * Send request, RETRY times, or until successful. |
| 470 | */ |
| 471 | for (try = 0; try < statp->retry; try++) { |
| 472 | for (ns = 0; ns < statp->nscount; ns++) |
| 473 | { |
| 474 | #ifdef DEBUG |
| 475 | char tmpbuf[40]; |
| 476 | #endif |
| 477 | #if defined USE_HOOKS || defined DEBUG |
| 478 | struct sockaddr *nsap = get_nsaddr (statp, ns); |
| 479 | #endif |
| 480 | |
| 481 | same_ns: |
| 482 | #ifdef USE_HOOKS |
| 483 | if (__glibc_unlikely (statp->qhook != NULL)) { |
| 484 | int done = 0, loops = 0; |
| 485 | |
| 486 | do { |
| 487 | res_sendhookact act; |
| 488 | |
| 489 | struct sockaddr_in *nsap4; |
| 490 | nsap4 = (struct sockaddr_in *) nsap; |
| 491 | act = (*statp->qhook)(&nsap4, &buf, &buflen, |
| 492 | ans, anssiz, &resplen); |
| 493 | nsap = (struct sockaddr_in6 *) nsap4; |
| 494 | switch (act) { |
| 495 | case res_goahead: |
| 496 | done = 1; |
| 497 | break; |
| 498 | case res_nextns: |
| 499 | __res_iclose(statp, false); |
| 500 | goto next_ns; |
| 501 | case res_done: |
| 502 | return (resplen); |
| 503 | case res_modified: |
| 504 | /* give the hook another try */ |
| 505 | if (++loops < 42) /*doug adams*/ |
| 506 | break; |
| 507 | /*FALLTHROUGH*/ |
| 508 | case res_error: |
| 509 | /*FALLTHROUGH*/ |
| 510 | default: |
| 511 | return (-1); |
| 512 | } |
| 513 | } while (!done); |
| 514 | } |
| 515 | #endif |
| 516 | |
| 517 | Dprint(statp->options & RES_DEBUG, |
| 518 | (stdout, ";; Querying server (# %d) address = %s\n", |
| 519 | ns + 1, inet_ntop(nsap->sa_family, |
| 520 | (nsap->sa_family == AF_INET6 |
| 521 | ? (void *) &((struct sockaddr_in6 *) nsap)->sin6_addr |
| 522 | : (void *) &((struct sockaddr_in *) nsap)->sin_addr), |
| 523 | tmpbuf, sizeof (tmpbuf)))); |
| 524 | |
| 525 | if (__glibc_unlikely (v_circuit)) { |
| 526 | /* Use VC; at most one attempt per server. */ |
| 527 | try = statp->retry; |
| 528 | n = send_vc(statp, buf, buflen, buf2, buflen2, |
| 529 | &ans, &anssiz, &terrno, |
| 530 | ns, ansp, ansp2, nansp2, resplen2, |
| 531 | ansp2_malloced); |
| 532 | if (n < 0) |
| 533 | return (-1); |
| 534 | if (n == 0 && (buf2 == NULL || *resplen2 == 0)) |
| 535 | goto next_ns; |
| 536 | } else { |
| 537 | /* Use datagrams. */ |
| 538 | n = send_dg(statp, buf, buflen, buf2, buflen2, |
| 539 | &ans, &anssiz, &terrno, |
| 540 | ns, &v_circuit, &gotsomewhere, ansp, |
| 541 | ansp2, nansp2, resplen2, ansp2_malloced); |
| 542 | if (n < 0) |
| 543 | return (-1); |
| 544 | if (n == 0 && (buf2 == NULL || *resplen2 == 0)) |
| 545 | goto next_ns; |
| 546 | if (v_circuit) |
| 547 | // XXX Check whether both requests failed or |
| 548 | // XXX whether one has been answered successfully |
| 549 | goto same_ns; |
| 550 | } |
| 551 | |
| 552 | resplen = n; |
| 553 | |
| 554 | Dprint((statp->options & RES_DEBUG) || |
| 555 | ((statp->pfcode & RES_PRF_REPLY) && |
| 556 | (statp->pfcode & RES_PRF_HEAD1)), |
| 557 | (stdout, ";; got answer:\n")); |
| 558 | |
| 559 | DprintQ((statp->options & RES_DEBUG) || |
| 560 | (statp->pfcode & RES_PRF_REPLY), |
| 561 | (stdout, "%s", ""), |
| 562 | ans, (resplen > anssiz) ? anssiz : resplen); |
| 563 | if (buf2 != NULL) { |
| 564 | DprintQ((statp->options & RES_DEBUG) || |
| 565 | (statp->pfcode & RES_PRF_REPLY), |
| 566 | (stdout, "%s", ""), |
| 567 | *ansp2, (*resplen2 > *nansp2) ? *nansp2 : *resplen2); |
| 568 | } |
| 569 | |
| 570 | /* |
| 571 | * If we have temporarily opened a virtual circuit, |
| 572 | * or if we haven't been asked to keep a socket open, |
| 573 | * close the socket. |
| 574 | */ |
| 575 | if ((v_circuit && (statp->options & RES_USEVC) == 0) || |
| 576 | (statp->options & RES_STAYOPEN) == 0) { |
| 577 | __res_iclose(statp, false); |
| 578 | } |
| 579 | #ifdef USE_HOOKS |
| 580 | if (__glibc_unlikely (statp->rhook)) { |
| 581 | int done = 0, loops = 0; |
| 582 | |
| 583 | do { |
| 584 | res_sendhookact act; |
| 585 | |
| 586 | act = (*statp->rhook)((struct sockaddr_in *) |
| 587 | nsap, buf, buflen, |
| 588 | ans, anssiz, &resplen); |
| 589 | switch (act) { |
| 590 | case res_goahead: |
| 591 | case res_done: |
| 592 | done = 1; |
| 593 | break; |
| 594 | case res_nextns: |
| 595 | __res_iclose(statp, false); |
| 596 | goto next_ns; |
| 597 | case res_modified: |
| 598 | /* give the hook another try */ |
| 599 | if (++loops < 42) /*doug adams*/ |
| 600 | break; |
| 601 | /*FALLTHROUGH*/ |
| 602 | case res_error: |
| 603 | /*FALLTHROUGH*/ |
| 604 | default: |
| 605 | return (-1); |
| 606 | } |
| 607 | } while (!done); |
| 608 | |
| 609 | } |
| 610 | #endif |
| 611 | return (resplen); |
| 612 | next_ns: ; |
| 613 | } /*foreach ns*/ |
| 614 | } /*foreach retry*/ |
| 615 | __res_iclose(statp, false); |
| 616 | if (!v_circuit) { |
| 617 | if (!gotsomewhere) |
| 618 | __set_errno (ECONNREFUSED); /* no nameservers found */ |
| 619 | else |
| 620 | __set_errno (ETIMEDOUT); /* no answer obtained */ |
| 621 | } else |
| 622 | __set_errno (terrno); |
| 623 | return (-1); |
| 624 | } |
| 625 | |
| 626 | int |
| 627 | res_nsend(res_state statp, |
| 628 | const u_char *buf, int buflen, u_char *ans, int anssiz) |
| 629 | { |
| 630 | return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz, |
| 631 | NULL, NULL, NULL, NULL, NULL); |
| 632 | } |
| 633 | libresolv_hidden_def (res_nsend) |
| 634 | |
| 635 | /* Private */ |
| 636 | |
| 637 | static struct sockaddr * |
| 638 | get_nsaddr (res_state statp, int n) |
| 639 | { |
| 640 | |
| 641 | if (statp->nsaddr_list[n].sin_family == 0 && EXT(statp).nsaddrs[n] != NULL) |
| 642 | /* EXT(statp).nsaddrs[n] holds an address that is larger than |
| 643 | struct sockaddr, and user code did not update |
| 644 | statp->nsaddr_list[n]. */ |
| 645 | return (struct sockaddr *) EXT(statp).nsaddrs[n]; |
| 646 | else |
| 647 | /* User code updated statp->nsaddr_list[n], or statp->nsaddr_list[n] |
| 648 | has the same content as EXT(statp).nsaddrs[n]. */ |
| 649 | return (struct sockaddr *) (void *) &statp->nsaddr_list[n]; |
| 650 | } |
| 651 | |
| 652 | /* The send_vc function is responsible for sending a DNS query over TCP |
| 653 | to the nameserver numbered NS from the res_state STATP i.e. |
| 654 | EXT(statp).nssocks[ns]. The function supports sending both IPv4 and |
| 655 | IPv6 queries at the same serially on the same socket. |
| 656 | |
| 657 | Please note that for TCP there is no way to disable sending both |
| 658 | queries, unlike UDP, which honours RES_SNGLKUP and RES_SNGLKUPREOP |
| 659 | and sends the queries serially and waits for the result after each |
| 660 | sent query. This implemetnation should be corrected to honour these |
| 661 | options. |
| 662 | |
| 663 | Please also note that for TCP we send both queries over the same |
| 664 | socket one after another. This technically violates best practice |
| 665 | since the server is allowed to read the first query, respond, and |
| 666 | then close the socket (to service another client). If the server |
| 667 | does this, then the remaining second query in the socket data buffer |
| 668 | will cause the server to send the client an RST which will arrive |
| 669 | asynchronously and the client's OS will likely tear down the socket |
| 670 | receive buffer resulting in a potentially short read and lost |
| 671 | response data. This will force the client to retry the query again, |
| 672 | and this process may repeat until all servers and connection resets |
| 673 | are exhausted and then the query will fail. It's not known if this |
| 674 | happens with any frequency in real DNS server implementations. This |
| 675 | implementation should be corrected to use two sockets by default for |
| 676 | parallel queries. |
| 677 | |
| 678 | The query stored in BUF of BUFLEN length is sent first followed by |
| 679 | the query stored in BUF2 of BUFLEN2 length. Queries are sent |
| 680 | serially on the same socket. |
| 681 | |
| 682 | Answers to the query are stored firstly in *ANSP up to a max of |
| 683 | *ANSSIZP bytes. If more than *ANSSIZP bytes are needed and ANSCP |
| 684 | is non-NULL (to indicate that modifying the answer buffer is allowed) |
| 685 | then malloc is used to allocate a new response buffer and ANSCP and |
| 686 | ANSP will both point to the new buffer. If more than *ANSSIZP bytes |
| 687 | are needed but ANSCP is NULL, then as much of the response as |
| 688 | possible is read into the buffer, but the results will be truncated. |
| 689 | When truncation happens because of a small answer buffer the DNS |
| 690 | packets header field TC will bet set to 1, indicating a truncated |
| 691 | message and the rest of the socket data will be read and discarded. |
| 692 | |
| 693 | Answers to the query are stored secondly in *ANSP2 up to a max of |
| 694 | *ANSSIZP2 bytes, with the actual response length stored in |
| 695 | *RESPLEN2. If more than *ANSSIZP bytes are needed and ANSP2 |
| 696 | is non-NULL (required for a second query) then malloc is used to |
| 697 | allocate a new response buffer, *ANSSIZP2 is set to the new buffer |
| 698 | size and *ANSP2_MALLOCED is set to 1. |
| 699 | |
| 700 | The ANSP2_MALLOCED argument will eventually be removed as the |
| 701 | change in buffer pointer can be used to detect the buffer has |
| 702 | changed and that the caller should use free on the new buffer. |
| 703 | |
| 704 | Note that the answers may arrive in any order from the server and |
| 705 | therefore the first and second answer buffers may not correspond to |
| 706 | the first and second queries. |
| 707 | |
| 708 | It is not supported to call this function with a non-NULL ANSP2 |
| 709 | but a NULL ANSCP. Put another way, you can call send_vc with a |
| 710 | single unmodifiable buffer or two modifiable buffers, but no other |
| 711 | combination is supported. |
| 712 | |
| 713 | It is the caller's responsibility to free the malloc allocated |
| 714 | buffers by detecting that the pointers have changed from their |
| 715 | original values i.e. *ANSCP or *ANSP2 has changed. |
| 716 | |
| 717 | If errors are encountered then *TERRNO is set to an appropriate |
| 718 | errno value and a zero result is returned for a recoverable error, |
| 719 | and a less-than zero result is returned for a non-recoverable error. |
| 720 | |
| 721 | If no errors are encountered then *TERRNO is left unmodified and |
| 722 | a the length of the first response in bytes is returned. */ |
| 723 | static int |
| 724 | send_vc(res_state statp, |
| 725 | const u_char *buf, int buflen, const u_char *buf2, int buflen2, |
| 726 | u_char **ansp, int *anssizp, |
| 727 | int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2, |
| 728 | int *resplen2, int *ansp2_malloced) |
| 729 | { |
| 730 | const HEADER *hp = (HEADER *) buf; |
| 731 | const HEADER *hp2 = (HEADER *) buf2; |
| 732 | HEADER *anhp = (HEADER *) *ansp; |
| 733 | struct sockaddr *nsap = get_nsaddr (statp, ns); |
| 734 | int truncating, connreset, n; |
| 735 | /* On some architectures compiler might emit a warning indicating |
| 736 | 'resplen' may be used uninitialized. However if buf2 == NULL |
| 737 | then this code won't be executed; if buf2 != NULL, then first |
| 738 | time round the loop recvresp1 and recvresp2 will be 0 so this |
| 739 | code won't be executed but "thisresplenp = &resplen;" followed |
| 740 | by "*thisresplenp = rlen;" will be executed so that subsequent |
| 741 | times round the loop resplen has been initialized. So this is |
| 742 | a false-positive. |
| 743 | */ |
| 744 | DIAG_PUSH_NEEDS_COMMENT; |
| 745 | DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized"); |
| 746 | int resplen; |
| 747 | DIAG_POP_NEEDS_COMMENT; |
| 748 | struct iovec iov[4]; |
| 749 | u_short len; |
| 750 | u_short len2; |
| 751 | u_char *cp; |
| 752 | |
| 753 | if (resplen2 != NULL) |
| 754 | *resplen2 = 0; |
| 755 | connreset = 0; |
| 756 | same_ns: |
| 757 | truncating = 0; |
| 758 | |
| 759 | /* Are we still talking to whom we want to talk to? */ |
| 760 | if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) { |
| 761 | struct sockaddr_in6 peer; |
| 762 | socklen_t size = sizeof peer; |
| 763 | |
| 764 | if (getpeername(statp->_vcsock, |
| 765 | (struct sockaddr *)&peer, &size) < 0 || |
| 766 | !sock_eq(&peer, (struct sockaddr_in6 *) nsap)) { |
| 767 | __res_iclose(statp, false); |
| 768 | statp->_flags &= ~RES_F_VC; |
| 769 | } |
| 770 | } |
| 771 | |
| 772 | if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) { |
| 773 | if (statp->_vcsock >= 0) |
| 774 | __res_iclose(statp, false); |
| 775 | |
| 776 | statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM, 0); |
| 777 | if (statp->_vcsock < 0) { |
| 778 | *terrno = errno; |
| 779 | Perror(statp, stderr, "socket(vc)", errno); |
| 780 | return (-1); |
| 781 | } |
| 782 | __set_errno (0); |
| 783 | if (connect(statp->_vcsock, nsap, |
| 784 | nsap->sa_family == AF_INET |
| 785 | ? sizeof (struct sockaddr_in) |
| 786 | : sizeof (struct sockaddr_in6)) < 0) { |
| 787 | *terrno = errno; |
| 788 | Aerror(statp, stderr, "connect/vc", errno, nsap); |
| 789 | __res_iclose(statp, false); |
| 790 | return (0); |
| 791 | } |
| 792 | statp->_flags |= RES_F_VC; |
| 793 | } |
| 794 | |
| 795 | /* |
| 796 | * Send length & message |
| 797 | */ |
| 798 | len = htons ((u_short) buflen); |
| 799 | evConsIovec(&len, INT16SZ, &iov[0]); |
| 800 | evConsIovec((void*)buf, buflen, &iov[1]); |
| 801 | int niov = 2; |
| 802 | ssize_t explen = INT16SZ + buflen; |
| 803 | if (buf2 != NULL) { |
| 804 | len2 = htons ((u_short) buflen2); |
| 805 | evConsIovec(&len2, INT16SZ, &iov[2]); |
| 806 | evConsIovec((void*)buf2, buflen2, &iov[3]); |
| 807 | niov = 4; |
| 808 | explen += INT16SZ + buflen2; |
| 809 | } |
| 810 | if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, niov)) != explen) { |
| 811 | *terrno = errno; |
| 812 | Perror(statp, stderr, "write failed", errno); |
| 813 | __res_iclose(statp, false); |
| 814 | return (0); |
| 815 | } |
| 816 | /* |
| 817 | * Receive length & response |
| 818 | */ |
| 819 | int recvresp1 = 0; |
| 820 | /* Skip the second response if there is no second query. |
| 821 | To do that we mark the second response as received. */ |
| 822 | int recvresp2 = buf2 == NULL; |
| 823 | uint16_t rlen16; |
| 824 | read_len: |
| 825 | cp = (u_char *)&rlen16; |
| 826 | len = sizeof(rlen16); |
| 827 | while ((n = TEMP_FAILURE_RETRY (read(statp->_vcsock, cp, |
| 828 | (int)len))) > 0) { |
| 829 | cp += n; |
| 830 | if ((len -= n) <= 0) |
| 831 | break; |
| 832 | } |
| 833 | if (n <= 0) { |
| 834 | *terrno = errno; |
| 835 | Perror(statp, stderr, "read failed", errno); |
| 836 | __res_iclose(statp, false); |
| 837 | /* |
| 838 | * A long running process might get its TCP |
| 839 | * connection reset if the remote server was |
| 840 | * restarted. Requery the server instead of |
| 841 | * trying a new one. When there is only one |
| 842 | * server, this means that a query might work |
| 843 | * instead of failing. We only allow one reset |
| 844 | * per query to prevent looping. |
| 845 | */ |
| 846 | if (*terrno == ECONNRESET && !connreset) { |
| 847 | connreset = 1; |
| 848 | goto same_ns; |
| 849 | } |
| 850 | return (0); |
| 851 | } |
| 852 | int rlen = ntohs (rlen16); |
| 853 | |
| 854 | int *thisanssizp; |
| 855 | u_char **thisansp; |
| 856 | int *thisresplenp; |
| 857 | if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { |
| 858 | /* We have not received any responses |
| 859 | yet or we only have one response to |
| 860 | receive. */ |
| 861 | thisanssizp = anssizp; |
| 862 | thisansp = anscp ?: ansp; |
| 863 | assert (anscp != NULL || ansp2 == NULL); |
| 864 | thisresplenp = &resplen; |
| 865 | } else { |
| 866 | thisanssizp = anssizp2; |
| 867 | thisansp = ansp2; |
| 868 | thisresplenp = resplen2; |
| 869 | } |
| 870 | anhp = (HEADER *) *thisansp; |
| 871 | |
| 872 | *thisresplenp = rlen; |
| 873 | /* Is the answer buffer too small? */ |
| 874 | if (*thisanssizp < rlen) { |
| 875 | /* If the current buffer is not the the static |
| 876 | user-supplied buffer then we can reallocate |
| 877 | it. */ |
| 878 | if (thisansp != NULL && thisansp != ansp) { |
| 879 | /* Always allocate MAXPACKET, callers expect |
| 880 | this specific size. */ |
| 881 | u_char *newp = malloc (MAXPACKET); |
| 882 | if (newp == NULL) { |
| 883 | *terrno = ENOMEM; |
| 884 | __res_iclose(statp, false); |
| 885 | return (0); |
| 886 | } |
| 887 | *thisanssizp = MAXPACKET; |
| 888 | *thisansp = newp; |
| 889 | if (thisansp == ansp2) |
| 890 | *ansp2_malloced = 1; |
| 891 | anhp = (HEADER *) newp; |
| 892 | /* A uint16_t can't be larger than MAXPACKET |
| 893 | thus it's safe to allocate MAXPACKET but |
| 894 | read RLEN bytes instead. */ |
| 895 | len = rlen; |
| 896 | } else { |
| 897 | Dprint(statp->options & RES_DEBUG, |
| 898 | (stdout, ";; response truncated\n") |
| 899 | ); |
| 900 | truncating = 1; |
| 901 | len = *thisanssizp; |
| 902 | } |
| 903 | } else |
| 904 | len = rlen; |
| 905 | |
| 906 | if (__glibc_unlikely (len < HFIXEDSZ)) { |
| 907 | /* |
| 908 | * Undersized message. |
| 909 | */ |
| 910 | Dprint(statp->options & RES_DEBUG, |
| 911 | (stdout, ";; undersized: %d\n", len)); |
| 912 | *terrno = EMSGSIZE; |
| 913 | __res_iclose(statp, false); |
| 914 | return (0); |
| 915 | } |
| 916 | |
| 917 | cp = *thisansp; |
| 918 | while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){ |
| 919 | cp += n; |
| 920 | len -= n; |
| 921 | } |
| 922 | if (__glibc_unlikely (n <= 0)) { |
| 923 | *terrno = errno; |
| 924 | Perror(statp, stderr, "read(vc)", errno); |
| 925 | __res_iclose(statp, false); |
| 926 | return (0); |
| 927 | } |
| 928 | if (__glibc_unlikely (truncating)) { |
| 929 | /* |
| 930 | * Flush rest of answer so connection stays in synch. |
| 931 | */ |
| 932 | anhp->tc = 1; |
| 933 | len = rlen - *thisanssizp; |
| 934 | while (len != 0) { |
| 935 | char junk[PACKETSZ]; |
| 936 | |
| 937 | n = read(statp->_vcsock, junk, |
| 938 | (len > sizeof junk) ? sizeof junk : len); |
| 939 | if (n > 0) |
| 940 | len -= n; |
| 941 | else |
| 942 | break; |
| 943 | } |
| 944 | } |
| 945 | /* |
| 946 | * If the calling application has bailed out of |
| 947 | * a previous call and failed to arrange to have |
| 948 | * the circuit closed or the server has got |
| 949 | * itself confused, then drop the packet and |
| 950 | * wait for the correct one. |
| 951 | */ |
| 952 | if ((recvresp1 || hp->id != anhp->id) |
| 953 | && (recvresp2 || hp2->id != anhp->id)) { |
| 954 | DprintQ((statp->options & RES_DEBUG) || |
| 955 | (statp->pfcode & RES_PRF_REPLY), |
| 956 | (stdout, ";; old answer (unexpected):\n"), |
| 957 | *thisansp, |
| 958 | (rlen > *thisanssizp) ? *thisanssizp: rlen); |
| 959 | goto read_len; |
| 960 | } |
| 961 | |
| 962 | /* Mark which reply we received. */ |
| 963 | if (recvresp1 == 0 && hp->id == anhp->id) |
| 964 | recvresp1 = 1; |
| 965 | else |
| 966 | recvresp2 = 1; |
| 967 | /* Repeat waiting if we have a second answer to arrive. */ |
| 968 | if ((recvresp1 & recvresp2) == 0) |
| 969 | goto read_len; |
| 970 | |
| 971 | /* |
| 972 | * All is well, or the error is fatal. Signal that the |
| 973 | * next nameserver ought not be tried. |
| 974 | */ |
| 975 | return resplen; |
| 976 | } |
| 977 | |
| 978 | static int |
| 979 | reopen (res_state statp, int *terrno, int ns) |
| 980 | { |
| 981 | if (EXT(statp).nssocks[ns] == -1) { |
| 982 | struct sockaddr *nsap = get_nsaddr (statp, ns); |
| 983 | socklen_t slen; |
| 984 | |
| 985 | /* only try IPv6 if IPv6 NS and if not failed before */ |
| 986 | if (nsap->sa_family == AF_INET6 && !statp->ipv6_unavail) { |
| 987 | EXT(statp).nssocks[ns] |
| 988 | = socket(PF_INET6, SOCK_DGRAM|SOCK_NONBLOCK, 0); |
| 989 | if (EXT(statp).nssocks[ns] < 0) |
| 990 | statp->ipv6_unavail = errno == EAFNOSUPPORT; |
| 991 | slen = sizeof (struct sockaddr_in6); |
| 992 | } else if (nsap->sa_family == AF_INET) { |
| 993 | EXT(statp).nssocks[ns] |
| 994 | = socket(PF_INET, SOCK_DGRAM|SOCK_NONBLOCK, 0); |
| 995 | slen = sizeof (struct sockaddr_in); |
| 996 | } |
| 997 | if (EXT(statp).nssocks[ns] < 0) { |
| 998 | *terrno = errno; |
| 999 | Perror(statp, stderr, "socket(dg)", errno); |
| 1000 | return (-1); |
| 1001 | } |
| 1002 | |
| 1003 | /* |
| 1004 | * On a 4.3BSD+ machine (client and server, |
| 1005 | * actually), sending to a nameserver datagram |
| 1006 | * port with no nameserver will cause an |
| 1007 | * ICMP port unreachable message to be returned. |
| 1008 | * If our datagram socket is "connected" to the |
| 1009 | * server, we get an ECONNREFUSED error on the next |
| 1010 | * socket operation, and select returns if the |
| 1011 | * error message is received. We can thus detect |
| 1012 | * the absence of a nameserver without timing out. |
| 1013 | */ |
| 1014 | if (connect(EXT(statp).nssocks[ns], nsap, slen) < 0) { |
| 1015 | Aerror(statp, stderr, "connect(dg)", errno, nsap); |
| 1016 | __res_iclose(statp, false); |
| 1017 | return (0); |
| 1018 | } |
| 1019 | } |
| 1020 | |
| 1021 | return 1; |
| 1022 | } |
| 1023 | |
| 1024 | /* The send_dg function is responsible for sending a DNS query over UDP |
| 1025 | to the nameserver numbered NS from the res_state STATP i.e. |
| 1026 | EXT(statp).nssocks[ns]. The function supports IPv4 and IPv6 queries |
| 1027 | along with the ability to send the query in parallel for both stacks |
| 1028 | (default) or serially (RES_SINGLKUP). It also supports serial lookup |
| 1029 | with a close and reopen of the socket used to talk to the server |
| 1030 | (RES_SNGLKUPREOP) to work around broken name servers. |
| 1031 | |
| 1032 | The query stored in BUF of BUFLEN length is sent first followed by |
| 1033 | the query stored in BUF2 of BUFLEN2 length. Queries are sent |
| 1034 | in parallel (default) or serially (RES_SINGLKUP or RES_SNGLKUPREOP). |
| 1035 | |
| 1036 | Answers to the query are stored firstly in *ANSP up to a max of |
| 1037 | *ANSSIZP bytes. If more than *ANSSIZP bytes are needed and ANSCP |
| 1038 | is non-NULL (to indicate that modifying the answer buffer is allowed) |
| 1039 | then malloc is used to allocate a new response buffer and ANSCP and |
| 1040 | ANSP will both point to the new buffer. If more than *ANSSIZP bytes |
| 1041 | are needed but ANSCP is NULL, then as much of the response as |
| 1042 | possible is read into the buffer, but the results will be truncated. |
| 1043 | When truncation happens because of a small answer buffer the DNS |
| 1044 | packets header field TC will bet set to 1, indicating a truncated |
| 1045 | message, while the rest of the UDP packet is discarded. |
| 1046 | |
| 1047 | Answers to the query are stored secondly in *ANSP2 up to a max of |
| 1048 | *ANSSIZP2 bytes, with the actual response length stored in |
| 1049 | *RESPLEN2. If more than *ANSSIZP bytes are needed and ANSP2 |
| 1050 | is non-NULL (required for a second query) then malloc is used to |
| 1051 | allocate a new response buffer, *ANSSIZP2 is set to the new buffer |
| 1052 | size and *ANSP2_MALLOCED is set to 1. |
| 1053 | |
| 1054 | The ANSP2_MALLOCED argument will eventually be removed as the |
| 1055 | change in buffer pointer can be used to detect the buffer has |
| 1056 | changed and that the caller should use free on the new buffer. |
| 1057 | |
| 1058 | Note that the answers may arrive in any order from the server and |
| 1059 | therefore the first and second answer buffers may not correspond to |
| 1060 | the first and second queries. |
| 1061 | |
| 1062 | It is not supported to call this function with a non-NULL ANSP2 |
| 1063 | but a NULL ANSCP. Put another way, you can call send_vc with a |
| 1064 | single unmodifiable buffer or two modifiable buffers, but no other |
| 1065 | combination is supported. |
| 1066 | |
| 1067 | It is the caller's responsibility to free the malloc allocated |
| 1068 | buffers by detecting that the pointers have changed from their |
| 1069 | original values i.e. *ANSCP or *ANSP2 has changed. |
| 1070 | |
| 1071 | If an answer is truncated because of UDP datagram DNS limits then |
| 1072 | *V_CIRCUIT is set to 1 and the return value non-zero to indicate to |
| 1073 | the caller to retry with TCP. The value *GOTSOMEWHERE is set to 1 |
| 1074 | if any progress was made reading a response from the nameserver and |
| 1075 | is used by the caller to distinguish between ECONNREFUSED and |
| 1076 | ETIMEDOUT (the latter if *GOTSOMEWHERE is 1). |
| 1077 | |
| 1078 | If errors are encountered then *TERRNO is set to an appropriate |
| 1079 | errno value and a zero result is returned for a recoverable error, |
| 1080 | and a less-than zero result is returned for a non-recoverable error. |
| 1081 | |
| 1082 | If no errors are encountered then *TERRNO is left unmodified and |
| 1083 | a the length of the first response in bytes is returned. */ |
| 1084 | static int |
| 1085 | send_dg(res_state statp, |
| 1086 | const u_char *buf, int buflen, const u_char *buf2, int buflen2, |
| 1087 | u_char **ansp, int *anssizp, |
| 1088 | int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp, |
| 1089 | u_char **ansp2, int *anssizp2, int *resplen2, int *ansp2_malloced) |
| 1090 | { |
| 1091 | const HEADER *hp = (HEADER *) buf; |
| 1092 | const HEADER *hp2 = (HEADER *) buf2; |
| 1093 | struct timespec now, timeout, finish; |
| 1094 | struct pollfd pfd[1]; |
| 1095 | int ptimeout; |
| 1096 | struct sockaddr_in6 from; |
| 1097 | int resplen = 0; |
| 1098 | int n; |
| 1099 | |
| 1100 | /* |
| 1101 | * Compute time for the total operation. |
| 1102 | */ |
| 1103 | int seconds = (statp->retrans << ns); |
| 1104 | if (ns > 0) |
| 1105 | seconds /= statp->nscount; |
| 1106 | if (seconds <= 0) |
| 1107 | seconds = 1; |
| 1108 | bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0; |
| 1109 | bool single_request = (((statp->options & RES_SNGLKUP) != 0) |
| 1110 | | single_request_reopen); |
| 1111 | int save_gotsomewhere = *gotsomewhere; |
| 1112 | |
| 1113 | int retval; |
| 1114 | retry_reopen: |
| 1115 | retval = reopen (statp, terrno, ns); |
| 1116 | if (retval <= 0) |
| 1117 | return retval; |
| 1118 | retry: |
| 1119 | evNowTime(&now); |
| 1120 | evConsTime(&timeout, seconds, 0); |
| 1121 | evAddTime(&finish, &now, &timeout); |
| 1122 | int need_recompute = 0; |
| 1123 | int nwritten = 0; |
| 1124 | int recvresp1 = 0; |
| 1125 | /* Skip the second response if there is no second query. |
| 1126 | To do that we mark the second response as received. */ |
| 1127 | int recvresp2 = buf2 == NULL; |
| 1128 | pfd[0].fd = EXT(statp).nssocks[ns]; |
| 1129 | pfd[0].events = POLLOUT; |
| 1130 | if (resplen2 != NULL) |
| 1131 | *resplen2 = 0; |
| 1132 | wait: |
| 1133 | if (need_recompute) { |
| 1134 | recompute_resend: |
| 1135 | evNowTime(&now); |
| 1136 | if (evCmpTime(finish, now) <= 0) { |
| 1137 | poll_err_out: |
| 1138 | Perror(statp, stderr, "poll", errno); |
| 1139 | err_out: |
| 1140 | __res_iclose(statp, false); |
| 1141 | return (0); |
| 1142 | } |
| 1143 | evSubTime(&timeout, &finish, &now); |
| 1144 | need_recompute = 0; |
| 1145 | } |
| 1146 | /* Convert struct timespec in milliseconds. */ |
| 1147 | ptimeout = timeout.tv_sec * 1000 + timeout.tv_nsec / 1000000; |
| 1148 | |
| 1149 | n = 0; |
| 1150 | if (nwritten == 0) |
| 1151 | n = __poll (pfd, 1, 0); |
| 1152 | if (__glibc_unlikely (n == 0)) { |
| 1153 | n = __poll (pfd, 1, ptimeout); |
| 1154 | need_recompute = 1; |
| 1155 | } |
| 1156 | if (n == 0) { |
| 1157 | Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n")); |
| 1158 | if (resplen > 1 && (recvresp1 || (buf2 != NULL && recvresp2))) |
| 1159 | { |
| 1160 | /* There are quite a few broken name servers out |
| 1161 | there which don't handle two outstanding |
| 1162 | requests from the same source. There are also |
| 1163 | broken firewall settings. If we time out after |
| 1164 | having received one answer switch to the mode |
| 1165 | where we send the second request only once we |
| 1166 | have received the first answer. */ |
| 1167 | if (!single_request) |
| 1168 | { |
| 1169 | statp->options |= RES_SNGLKUP; |
| 1170 | single_request = true; |
| 1171 | *gotsomewhere = save_gotsomewhere; |
| 1172 | goto retry; |
| 1173 | } |
| 1174 | else if (!single_request_reopen) |
| 1175 | { |
| 1176 | statp->options |= RES_SNGLKUPREOP; |
| 1177 | single_request_reopen = true; |
| 1178 | *gotsomewhere = save_gotsomewhere; |
| 1179 | __res_iclose (statp, false); |
| 1180 | goto retry_reopen; |
| 1181 | } |
| 1182 | |
| 1183 | *resplen2 = 1; |
| 1184 | return resplen; |
| 1185 | } |
| 1186 | |
| 1187 | *gotsomewhere = 1; |
| 1188 | return (0); |
| 1189 | } |
| 1190 | if (n < 0) { |
| 1191 | if (errno == EINTR) |
| 1192 | goto recompute_resend; |
| 1193 | |
| 1194 | goto poll_err_out; |
| 1195 | } |
| 1196 | __set_errno (0); |
| 1197 | if (pfd[0].revents & POLLOUT) { |
| 1198 | #ifndef __ASSUME_SENDMMSG |
| 1199 | static int have_sendmmsg; |
| 1200 | #else |
| 1201 | # define have_sendmmsg 1 |
| 1202 | #endif |
| 1203 | if (have_sendmmsg >= 0 && nwritten == 0 && buf2 != NULL |
| 1204 | && !single_request) |
| 1205 | { |
| 1206 | struct iovec iov[2]; |
| 1207 | struct mmsghdr reqs[2]; |
| 1208 | reqs[0].msg_hdr.msg_name = NULL; |
| 1209 | reqs[0].msg_hdr.msg_namelen = 0; |
| 1210 | reqs[0].msg_hdr.msg_iov = &iov[0]; |
| 1211 | reqs[0].msg_hdr.msg_iovlen = 1; |
| 1212 | iov[0].iov_base = (void *) buf; |
| 1213 | iov[0].iov_len = buflen; |
| 1214 | reqs[0].msg_hdr.msg_control = NULL; |
| 1215 | reqs[0].msg_hdr.msg_controllen = 0; |
| 1216 | |
| 1217 | reqs[1].msg_hdr.msg_name = NULL; |
| 1218 | reqs[1].msg_hdr.msg_namelen = 0; |
| 1219 | reqs[1].msg_hdr.msg_iov = &iov[1]; |
| 1220 | reqs[1].msg_hdr.msg_iovlen = 1; |
| 1221 | iov[1].iov_base = (void *) buf2; |
| 1222 | iov[1].iov_len = buflen2; |
| 1223 | reqs[1].msg_hdr.msg_control = NULL; |
| 1224 | reqs[1].msg_hdr.msg_controllen = 0; |
| 1225 | |
| 1226 | int ndg = __sendmmsg (pfd[0].fd, reqs, 2, MSG_NOSIGNAL); |
| 1227 | if (__glibc_likely (ndg == 2)) |
| 1228 | { |
| 1229 | if (reqs[0].msg_len != buflen |
| 1230 | || reqs[1].msg_len != buflen2) |
| 1231 | goto fail_sendmmsg; |
| 1232 | |
| 1233 | pfd[0].events = POLLIN; |
| 1234 | nwritten += 2; |
| 1235 | } |
| 1236 | else if (ndg == 1 && reqs[0].msg_len == buflen) |
| 1237 | goto just_one; |
| 1238 | else if (ndg < 0 && (errno == EINTR || errno == EAGAIN)) |
| 1239 | goto recompute_resend; |
| 1240 | else |
| 1241 | { |
| 1242 | #ifndef __ASSUME_SENDMMSG |
| 1243 | if (__glibc_unlikely (have_sendmmsg == 0)) |
| 1244 | { |
| 1245 | if (ndg < 0 && errno == ENOSYS) |
| 1246 | { |
| 1247 | have_sendmmsg = -1; |
| 1248 | goto try_send; |
| 1249 | } |
| 1250 | have_sendmmsg = 1; |
| 1251 | } |
| 1252 | #endif |
| 1253 | |
| 1254 | fail_sendmmsg: |
| 1255 | Perror(statp, stderr, "sendmmsg", errno); |
| 1256 | goto err_out; |
| 1257 | } |
| 1258 | } |
| 1259 | else |
| 1260 | { |
| 1261 | ssize_t sr; |
| 1262 | #ifndef __ASSUME_SENDMMSG |
| 1263 | try_send: |
| 1264 | #endif |
| 1265 | if (nwritten != 0) |
| 1266 | sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL); |
| 1267 | else |
| 1268 | sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL); |
| 1269 | |
| 1270 | if (sr != (nwritten != 0 ? buflen2 : buflen)) { |
| 1271 | if (errno == EINTR || errno == EAGAIN) |
| 1272 | goto recompute_resend; |
| 1273 | Perror(statp, stderr, "send", errno); |
| 1274 | goto err_out; |
| 1275 | } |
| 1276 | just_one: |
| 1277 | if (nwritten != 0 || buf2 == NULL || single_request) |
| 1278 | pfd[0].events = POLLIN; |
| 1279 | else |
| 1280 | pfd[0].events = POLLIN | POLLOUT; |
| 1281 | ++nwritten; |
| 1282 | } |
| 1283 | goto wait; |
| 1284 | } else if (pfd[0].revents & POLLIN) { |
| 1285 | int *thisanssizp; |
| 1286 | u_char **thisansp; |
| 1287 | int *thisresplenp; |
| 1288 | |
| 1289 | if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { |
| 1290 | /* We have not received any responses |
| 1291 | yet or we only have one response to |
| 1292 | receive. */ |
| 1293 | thisanssizp = anssizp; |
| 1294 | thisansp = anscp ?: ansp; |
| 1295 | assert (anscp != NULL || ansp2 == NULL); |
| 1296 | thisresplenp = &resplen; |
| 1297 | } else { |
| 1298 | thisanssizp = anssizp2; |
| 1299 | thisansp = ansp2; |
| 1300 | thisresplenp = resplen2; |
| 1301 | } |
| 1302 | |
| 1303 | if (*thisanssizp < MAXPACKET |
| 1304 | /* If the current buffer is not the the static |
| 1305 | user-supplied buffer then we can reallocate |
| 1306 | it. */ |
| 1307 | && (thisansp != NULL && thisansp != ansp) |
| 1308 | #ifdef FIONREAD |
| 1309 | /* Is the size too small? */ |
| 1310 | && (ioctl (pfd[0].fd, FIONREAD, thisresplenp) < 0 |
| 1311 | || *thisanssizp < *thisresplenp) |
| 1312 | #endif |
| 1313 | ) { |
| 1314 | /* Always allocate MAXPACKET, callers expect |
| 1315 | this specific size. */ |
| 1316 | u_char *newp = malloc (MAXPACKET); |
| 1317 | if (newp != NULL) { |
| 1318 | *thisanssizp = MAXPACKET; |
| 1319 | *thisansp = newp; |
| 1320 | if (thisansp == ansp2) |
| 1321 | *ansp2_malloced = 1; |
| 1322 | } |
| 1323 | } |
| 1324 | /* We could end up with truncation if anscp was NULL |
| 1325 | (not allowed to change caller's buffer) and the |
| 1326 | response buffer size is too small. This isn't a |
| 1327 | reliable way to detect truncation because the ioctl |
| 1328 | may be an inaccurate report of the UDP message size. |
| 1329 | Therefore we use this only to issue debug output. |
| 1330 | To do truncation accurately with UDP we need |
| 1331 | MSG_TRUNC which is only available on Linux. We |
| 1332 | can abstract out the Linux-specific feature in the |
| 1333 | future to detect truncation. */ |
| 1334 | if (__glibc_unlikely (*thisanssizp < *thisresplenp)) { |
| 1335 | Dprint(statp->options & RES_DEBUG, |
| 1336 | (stdout, ";; response may be truncated (UDP)\n") |
| 1337 | ); |
| 1338 | } |
| 1339 | |
| 1340 | HEADER *anhp = (HEADER *) *thisansp; |
| 1341 | socklen_t fromlen = sizeof(struct sockaddr_in6); |
| 1342 | assert (sizeof(from) <= fromlen); |
| 1343 | *thisresplenp = recvfrom(pfd[0].fd, (char*)*thisansp, |
| 1344 | *thisanssizp, 0, |
| 1345 | (struct sockaddr *)&from, &fromlen); |
| 1346 | if (__glibc_unlikely (*thisresplenp <= 0)) { |
| 1347 | if (errno == EINTR || errno == EAGAIN) { |
| 1348 | need_recompute = 1; |
| 1349 | goto wait; |
| 1350 | } |
| 1351 | Perror(statp, stderr, "recvfrom", errno); |
| 1352 | goto err_out; |
| 1353 | } |
| 1354 | *gotsomewhere = 1; |
| 1355 | if (__glibc_unlikely (*thisresplenp < HFIXEDSZ)) { |
| 1356 | /* |
| 1357 | * Undersized message. |
| 1358 | */ |
| 1359 | Dprint(statp->options & RES_DEBUG, |
| 1360 | (stdout, ";; undersized: %d\n", |
| 1361 | *thisresplenp)); |
| 1362 | *terrno = EMSGSIZE; |
| 1363 | goto err_out; |
| 1364 | } |
| 1365 | if ((recvresp1 || hp->id != anhp->id) |
| 1366 | && (recvresp2 || hp2->id != anhp->id)) { |
| 1367 | /* |
| 1368 | * response from old query, ignore it. |
| 1369 | * XXX - potential security hazard could |
| 1370 | * be detected here. |
| 1371 | */ |
| 1372 | DprintQ((statp->options & RES_DEBUG) || |
| 1373 | (statp->pfcode & RES_PRF_REPLY), |
| 1374 | (stdout, ";; old answer:\n"), |
| 1375 | *thisansp, |
| 1376 | (*thisresplenp > *thisanssizp) |
| 1377 | ? *thisanssizp : *thisresplenp); |
| 1378 | goto wait; |
| 1379 | } |
| 1380 | if (!(statp->options & RES_INSECURE1) && |
| 1381 | !res_ourserver_p(statp, &from)) { |
| 1382 | /* |
| 1383 | * response from wrong server? ignore it. |
| 1384 | * XXX - potential security hazard could |
| 1385 | * be detected here. |
| 1386 | */ |
| 1387 | DprintQ((statp->options & RES_DEBUG) || |
| 1388 | (statp->pfcode & RES_PRF_REPLY), |
| 1389 | (stdout, ";; not our server:\n"), |
| 1390 | *thisansp, |
| 1391 | (*thisresplenp > *thisanssizp) |
| 1392 | ? *thisanssizp : *thisresplenp); |
| 1393 | goto wait; |
| 1394 | } |
| 1395 | #ifdef RES_USE_EDNS0 |
| 1396 | if (anhp->rcode == FORMERR |
| 1397 | && (statp->options & RES_USE_EDNS0) != 0U) { |
| 1398 | /* |
| 1399 | * Do not retry if the server does not understand |
| 1400 | * EDNS0. The case has to be captured here, as |
| 1401 | * FORMERR packet do not carry query section, hence |
| 1402 | * res_queriesmatch() returns 0. |
| 1403 | */ |
| 1404 | DprintQ(statp->options & RES_DEBUG, |
| 1405 | (stdout, |
| 1406 | "server rejected query with EDNS0:\n"), |
| 1407 | *thisansp, |
| 1408 | (*thisresplenp > *thisanssizp) |
| 1409 | ? *thisanssizp : *thisresplenp); |
| 1410 | /* record the error */ |
| 1411 | statp->_flags |= RES_F_EDNS0ERR; |
| 1412 | goto err_out; |
| 1413 | } |
| 1414 | #endif |
| 1415 | if (!(statp->options & RES_INSECURE2) |
| 1416 | && (recvresp1 || !res_queriesmatch(buf, buf + buflen, |
| 1417 | *thisansp, |
| 1418 | *thisansp |
| 1419 | + *thisanssizp)) |
| 1420 | && (recvresp2 || !res_queriesmatch(buf2, buf2 + buflen2, |
| 1421 | *thisansp, |
| 1422 | *thisansp |
| 1423 | + *thisanssizp))) { |
| 1424 | /* |
| 1425 | * response contains wrong query? ignore it. |
| 1426 | * XXX - potential security hazard could |
| 1427 | * be detected here. |
| 1428 | */ |
| 1429 | DprintQ((statp->options & RES_DEBUG) || |
| 1430 | (statp->pfcode & RES_PRF_REPLY), |
| 1431 | (stdout, ";; wrong query name:\n"), |
| 1432 | *thisansp, |
| 1433 | (*thisresplenp > *thisanssizp) |
| 1434 | ? *thisanssizp : *thisresplenp); |
| 1435 | goto wait; |
| 1436 | } |
| 1437 | if (anhp->rcode == SERVFAIL || |
| 1438 | anhp->rcode == NOTIMP || |
| 1439 | anhp->rcode == REFUSED) { |
| 1440 | DprintQ(statp->options & RES_DEBUG, |
| 1441 | (stdout, "server rejected query:\n"), |
| 1442 | *thisansp, |
| 1443 | (*thisresplenp > *thisanssizp) |
| 1444 | ? *thisanssizp : *thisresplenp); |
| 1445 | |
| 1446 | next_ns: |
| 1447 | if (recvresp1 || (buf2 != NULL && recvresp2)) { |
| 1448 | *resplen2 = 0; |
| 1449 | return resplen; |
| 1450 | } |
| 1451 | if (buf2 != NULL) |
| 1452 | { |
| 1453 | /* No data from the first reply. */ |
| 1454 | resplen = 0; |
| 1455 | /* We are waiting for a possible second reply. */ |
| 1456 | if (hp->id == anhp->id) |
| 1457 | recvresp1 = 1; |
| 1458 | else |
| 1459 | recvresp2 = 1; |
| 1460 | |
| 1461 | goto wait; |
| 1462 | } |
| 1463 | |
| 1464 | __res_iclose(statp, false); |
| 1465 | /* don't retry if called from dig */ |
| 1466 | if (!statp->pfcode) |
| 1467 | return (0); |
| 1468 | } |
| 1469 | if (anhp->rcode == NOERROR && anhp->ancount == 0 |
| 1470 | && anhp->aa == 0 && anhp->ra == 0 && anhp->arcount == 0) { |
| 1471 | DprintQ(statp->options & RES_DEBUG, |
| 1472 | (stdout, "referred query:\n"), |
| 1473 | *thisansp, |
| 1474 | (*thisresplenp > *thisanssizp) |
| 1475 | ? *thisanssizp : *thisresplenp); |
| 1476 | goto next_ns; |
| 1477 | } |
| 1478 | if (!(statp->options & RES_IGNTC) && anhp->tc) { |
| 1479 | /* |
| 1480 | * To get the rest of answer, |
| 1481 | * use TCP with same server. |
| 1482 | */ |
| 1483 | Dprint(statp->options & RES_DEBUG, |
| 1484 | (stdout, ";; truncated answer\n")); |
| 1485 | *v_circuit = 1; |
| 1486 | __res_iclose(statp, false); |
| 1487 | // XXX if we have received one reply we could |
| 1488 | // XXX use it and not repeat it over TCP... |
| 1489 | return (1); |
| 1490 | } |
| 1491 | /* Mark which reply we received. */ |
| 1492 | if (recvresp1 == 0 && hp->id == anhp->id) |
| 1493 | recvresp1 = 1; |
| 1494 | else |
| 1495 | recvresp2 = 1; |
| 1496 | /* Repeat waiting if we have a second answer to arrive. */ |
| 1497 | if ((recvresp1 & recvresp2) == 0) { |
| 1498 | if (single_request) { |
| 1499 | pfd[0].events = POLLOUT; |
| 1500 | if (single_request_reopen) { |
| 1501 | __res_iclose (statp, false); |
| 1502 | retval = reopen (statp, terrno, ns); |
| 1503 | if (retval <= 0) |
| 1504 | return retval; |
| 1505 | pfd[0].fd = EXT(statp).nssocks[ns]; |
| 1506 | } |
| 1507 | } |
| 1508 | goto wait; |
| 1509 | } |
| 1510 | /* |
| 1511 | * All is well, or the error is fatal. Signal that the |
| 1512 | * next nameserver ought not be tried. |
| 1513 | */ |
| 1514 | return (resplen); |
| 1515 | } else if (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL)) { |
| 1516 | /* Something went wrong. We can stop trying. */ |
| 1517 | goto err_out; |
| 1518 | } |
| 1519 | else { |
| 1520 | /* poll should not have returned > 0 in this case. */ |
| 1521 | abort (); |
| 1522 | } |
| 1523 | } |
| 1524 | |
| 1525 | #ifdef DEBUG |
| 1526 | static void |
| 1527 | Aerror(const res_state statp, FILE *file, const char *string, int error, |
| 1528 | const struct sockaddr *address) |
| 1529 | { |
| 1530 | int save = errno; |
| 1531 | |
| 1532 | if ((statp->options & RES_DEBUG) != 0) { |
| 1533 | char tmp[sizeof "xxxx.xxxx.xxxx.255.255.255.255"]; |
| 1534 | |
| 1535 | fprintf(file, "res_send: %s ([%s].%u): %s\n", |
| 1536 | string, |
| 1537 | (address->sa_family == AF_INET |
| 1538 | ? inet_ntop(address->sa_family, |
| 1539 | &((const struct sockaddr_in *) address)->sin_addr, |
| 1540 | tmp, sizeof tmp) |
| 1541 | : inet_ntop(address->sa_family, |
| 1542 | &((const struct sockaddr_in6 *) address)->sin6_addr, |
| 1543 | tmp, sizeof tmp)), |
| 1544 | (address->sa_family == AF_INET |
| 1545 | ? ntohs(((struct sockaddr_in *) address)->sin_port) |
| 1546 | : address->sa_family == AF_INET6 |
| 1547 | ? ntohs(((struct sockaddr_in6 *) address)->sin6_port) |
| 1548 | : 0), |
| 1549 | strerror(error)); |
| 1550 | } |
| 1551 | __set_errno (save); |
| 1552 | } |
| 1553 | |
| 1554 | static void |
| 1555 | Perror(const res_state statp, FILE *file, const char *string, int error) { |
| 1556 | int save = errno; |
| 1557 | |
| 1558 | if ((statp->options & RES_DEBUG) != 0) |
| 1559 | fprintf(file, "res_send: %s: %s\n", |
| 1560 | string, strerror(error)); |
| 1561 | __set_errno (save); |
| 1562 | } |
| 1563 | #endif |
| 1564 | |
| 1565 | static int |
| 1566 | sock_eq(struct sockaddr_in6 *a1, struct sockaddr_in6 *a2) { |
| 1567 | if (a1->sin6_family == a2->sin6_family) { |
| 1568 | if (a1->sin6_family == AF_INET) |
| 1569 | return ((((struct sockaddr_in *)a1)->sin_port == |
| 1570 | ((struct sockaddr_in *)a2)->sin_port) && |
| 1571 | (((struct sockaddr_in *)a1)->sin_addr.s_addr == |
| 1572 | ((struct sockaddr_in *)a2)->sin_addr.s_addr)); |
| 1573 | else |
| 1574 | return ((a1->sin6_port == a2->sin6_port) && |
| 1575 | !memcmp(&a1->sin6_addr, &a2->sin6_addr, |
| 1576 | sizeof (struct in6_addr))); |
| 1577 | } |
| 1578 | if (a1->sin6_family == AF_INET) { |
| 1579 | struct sockaddr_in6 *sap = a1; |
| 1580 | a1 = a2; |
| 1581 | a2 = sap; |
| 1582 | } /* assumes that AF_INET and AF_INET6 are the only possibilities */ |
| 1583 | return ((a1->sin6_port == ((struct sockaddr_in *)a2)->sin_port) && |
| 1584 | IN6_IS_ADDR_V4MAPPED(&a1->sin6_addr) && |
| 1585 | (a1->sin6_addr.s6_addr32[3] == |
| 1586 | ((struct sockaddr_in *)a2)->sin_addr.s_addr)); |
| 1587 | } |