1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1985, 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 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 * --Copyright-- 50 */ 51/* Portions Copyright (c) 1993 Carlos Leandro and Rui Salgueiro 52 * Dep. Matematica Universidade de Coimbra, Portugal, Europe 53 * 54 * Permission to use, copy, modify, and distribute this software for any 55 * purpose with or without fee is hereby granted, provided that the above 56 * copyright notice and this permission notice appear in all copies. 57 */ 58 59#if defined(LIBC_SCCS) && !defined(lint) 60static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; 61#endif /* LIBC_SCCS and not lint */ 62#include <sys/cdefs.h> 63__FBSDID("$FreeBSD$"); 64 65#include <sys/param.h> 66#include <sys/socket.h> 67#include <netinet/in.h> 68#include <arpa/inet.h> 69#include <arpa/nameser.h> 70 71#include <errno.h> 72#include <stdio.h> 73#include <stdlib.h> 74#include <netdb.h> 75#include <resolv.h> 76#include <ctype.h> 77#include <string.h> 78#include <unistd.h> 79#include <syslog.h> 80#include <stdarg.h> 81#include <nsswitch.h> 82 83#include "netdb_private.h" 84#include "res_config.h" 85 86#define BYADDR 0 87#define BYNAME 1 88 89#define MAXPACKET (64*1024) 90 91typedef union { 92 HEADER hdr; 93 u_char buf[MAXPACKET]; 94} querybuf; 95 96typedef union { 97 long al; 98 char ac; 99} align; 100 101/* 102 * Reverse the order of first four dotted entries of in. 103 * Out must contain space for at least strlen(in) characters. 104 * The result does not include any leading 0s of in. 105 */ 106static void 107ipreverse(char *in, char *out) 108{ 109 char *pos[4]; 110 int len[4]; 111 char *p, *start; 112 int i = 0; 113 int leading = 1; 114 115 /* Fill-in element positions and lengths: pos[], len[]. */ 116 start = p = in; 117 for (;;) { 118 if (*p == '.' || *p == '\0') { 119 /* Leading 0? */ 120 if (leading && p - start == 1 && *start == '0') 121 len[i] = 0; 122 else { 123 len[i] = p - start; 124 leading = 0; 125 } 126 pos[i] = start; 127 start = p + 1; 128 i++; 129 } 130 if (i == 4) 131 break; 132 if (*p == 0) { 133 for (; i < 4; i++) { 134 pos[i] = p; 135 len[i] = 0; 136 } 137 break; 138 } 139 p++; 140 } 141 142 /* Copy the entries in reverse order */ 143 p = out; 144 leading = 1; 145 for (i = 3; i >= 0; i--) { 146 memcpy(p, pos[i], len[i]); 147 if (len[i]) 148 leading = 0; 149 p += len[i]; 150 /* Need a . separator? */ 151 if (!leading && i > 0 && len[i - 1]) 152 *p++ = '.'; 153 } 154 *p = '\0'; 155} 156 157static int 158getnetanswer(querybuf *answer, int anslen, int net_i, struct netent *ne, 159 struct netent_data *ned, res_state statp) 160{ 161 162 HEADER *hp; 163 u_char *cp; 164 int n; 165 u_char *eom; 166 int type, class, ancount, qdcount, haveanswer; 167 char aux[MAXHOSTNAMELEN]; 168 char ans[MAXHOSTNAMELEN]; 169 char *in, *bp, *ep, **ap; 170 171 /* 172 * find first satisfactory answer 173 * 174 * answer --> +------------+ ( MESSAGE ) 175 * | Header | 176 * +------------+ 177 * | Question | the question for the name server 178 * +------------+ 179 * | Answer | RRs answering the question 180 * +------------+ 181 * | Authority | RRs pointing toward an authority 182 * | Additional | RRs holding additional information 183 * +------------+ 184 */ 185 eom = answer->buf + anslen; 186 hp = &answer->hdr; 187 ancount = ntohs(hp->ancount); /* #/records in the answer section */ 188 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ 189 bp = ned->netbuf; 190 ep = ned->netbuf + sizeof(ned->netbuf); 191 cp = answer->buf + HFIXEDSZ; 192 if (!qdcount) { 193 if (hp->aa) 194 RES_SET_H_ERRNO(statp, HOST_NOT_FOUND); 195 else 196 RES_SET_H_ERRNO(statp, TRY_AGAIN); 197 return (-1); 198 } 199 while (qdcount-- > 0) 200 cp += __dn_skipname(cp, eom) + QFIXEDSZ; 201 ap = ned->net_aliases; 202 *ap = NULL; 203 ne->n_aliases = ned->net_aliases; 204 haveanswer = 0; 205 while (--ancount >= 0 && cp < eom) { 206 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 207 if ((n < 0) || !res_dnok(bp)) 208 break; 209 cp += n; 210 ans[0] = '\0'; 211 (void)strncpy(&ans[0], bp, sizeof(ans) - 1); 212 ans[sizeof(ans) - 1] = '\0'; 213 GETSHORT(type, cp); 214 GETSHORT(class, cp); 215 cp += INT32SZ; /* TTL */ 216 GETSHORT(n, cp); 217 if (class == C_IN && type == T_PTR) { 218 n = dn_expand(answer->buf, eom, cp, bp, ep - bp); 219 if ((n < 0) || !res_hnok(bp)) { 220 cp += n; 221 return (-1); 222 } 223 cp += n; 224 *ap++ = bp; 225 n = strlen(bp) + 1; 226 bp += n; 227 ne->n_addrtype = (class == C_IN) ? AF_INET : AF_UNSPEC; 228 haveanswer++; 229 } 230 } 231 if (haveanswer) { 232 *ap = NULL; 233 switch (net_i) { 234 case BYADDR: 235 ne->n_name = *ne->n_aliases; 236 ne->n_net = 0L; 237 break; 238 case BYNAME: 239 in = *ne->n_aliases; 240 n = strlen(ans) + 1; 241 if (ep - bp < n) { 242 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 243 errno = ENOBUFS; 244 return (-1); 245 } 246 strlcpy(bp, ans, ep - bp); 247 ne->n_name = bp; 248 if (strlen(in) + 1 > sizeof(aux)) { 249 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 250 errno = ENOBUFS; 251 return (-1); 252 } 253 ipreverse(in, aux); 254 ne->n_net = inet_network(aux); 255 break; 256 } 257 ne->n_aliases++; 258 return (0); 259 } 260 RES_SET_H_ERRNO(statp, TRY_AGAIN); 261 return (-1); 262} 263 264int 265_dns_getnetbyaddr(void *rval, void *cb_data, va_list ap) 266{ 267 uint32_t net; 268 int net_type; 269 char *buffer; 270 size_t buflen; 271 int *errnop, *h_errnop; 272 struct netent *nptr, ne; 273 struct netent_data *ned; 274 unsigned int netbr[4]; 275 int nn, anslen, error; 276 querybuf *buf; 277 char qbuf[MAXDNAME]; 278 uint32_t net2; 279 res_state statp; 280 281 net = va_arg(ap, uint32_t); 282 net_type = va_arg(ap, int); 283 nptr = va_arg(ap, struct netent *); 284 buffer = va_arg(ap, char *); 285 buflen = va_arg(ap, size_t); 286 errnop = va_arg(ap, int *); 287 h_errnop = va_arg(ap, int *); 288 289 statp = __res_state(); 290 if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) { 291 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 292 *h_errnop = statp->res_h_errno; 293 return (NS_UNAVAIL); 294 } 295 296 if ((ned = __netent_data_init()) == NULL) { 297 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 298 *h_errnop = statp->res_h_errno; 299 return (NS_UNAVAIL); 300 } 301 302 *((struct netent **)rval) = NULL; 303 304 if (net_type != AF_INET) { 305 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 306 *h_errnop = statp->res_h_errno; 307 return (NS_UNAVAIL); 308 } 309 310 for (nn = 4, net2 = net; net2; net2 >>= 8) 311 netbr[--nn] = net2 & 0xff; 312 switch (nn) { 313 case 3: /* Class A */ 314 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]); 315 break; 316 case 2: /* Class B */ 317 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]); 318 break; 319 case 1: /* Class C */ 320 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 321 netbr[1]); 322 break; 323 case 0: /* Class D - E */ 324 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 325 netbr[1], netbr[0]); 326 break; 327 } 328 if ((buf = malloc(sizeof(*buf))) == NULL) { 329 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 330 *h_errnop = statp->res_h_errno; 331 return (NS_NOTFOUND); 332 } 333 anslen = res_nquery(statp, qbuf, C_IN, T_PTR, (u_char *)buf, 334 sizeof(*buf)); 335 if (anslen < 0) { 336 free(buf); 337#ifdef DEBUG 338 if (statp->options & RES_DEBUG) 339 printf("res_nsearch failed\n"); 340#endif 341 *h_errnop = statp->res_h_errno; 342 return (NS_UNAVAIL); 343 } else if (anslen > sizeof(*buf)) { 344 free(buf); 345#ifdef DEBUG 346 if (statp->options & RES_DEBUG) 347 printf("res_nsearch static buffer too small\n"); 348#endif 349 *h_errnop = statp->res_h_errno; 350 return (NS_UNAVAIL); 351 } 352 error = getnetanswer(buf, anslen, BYADDR, &ne, ned, statp); 353 free(buf); 354 if (error == 0) { 355 /* Strip trailing zeros */ 356 while ((net & 0xff) == 0 && net != 0) 357 net >>= 8; 358 ne.n_net = net; 359 if (__copy_netent(&ne, nptr, buffer, buflen) != 0) { 360 *errnop = errno; 361 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 362 *h_errnop = statp->res_h_errno; 363 return (NS_RETURN); 364 } 365 *((struct netent **)rval) = nptr; 366 return (NS_SUCCESS); 367 } 368 *h_errnop = statp->res_h_errno; 369 return (NS_NOTFOUND); 370} 371 372int 373_dns_getnetbyname(void *rval, void *cb_data, va_list ap) 374{ 375 const char *net; 376 char *buffer; 377 size_t buflen; 378 int *errnop, *h_errnop; 379 struct netent *nptr, ne; 380 struct netent_data *ned; 381 int anslen, error; 382 querybuf *buf; 383 char qbuf[MAXDNAME]; 384 res_state statp; 385 386 net = va_arg(ap, const char *); 387 nptr = va_arg(ap, struct netent *); 388 buffer = va_arg(ap, char *); 389 buflen = va_arg(ap, size_t); 390 errnop = va_arg(ap, int *); 391 h_errnop = va_arg(ap, int *); 392 393 statp = __res_state(); 394 if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) { 395 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 396 *h_errnop = statp->res_h_errno; 397 return (NS_UNAVAIL); 398 } 399 if ((ned = __netent_data_init()) == NULL) { 400 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 401 *h_errnop = statp->res_h_errno; 402 return (NS_UNAVAIL); 403 } 404 if ((buf = malloc(sizeof(*buf))) == NULL) { 405 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 406 *h_errnop = statp->res_h_errno; 407 return (NS_NOTFOUND); 408 } 409 410 *((struct netent **)rval) = NULL; 411 412 strncpy(qbuf, net, sizeof(qbuf) - 1); 413 qbuf[sizeof(qbuf) - 1] = '\0'; 414 anslen = res_nsearch(statp, qbuf, C_IN, T_PTR, (u_char *)buf, 415 sizeof(*buf)); 416 if (anslen < 0) { 417 free(buf); 418#ifdef DEBUG 419 if (statp->options & RES_DEBUG) 420 printf("res_nsearch failed\n"); 421#endif 422 return (NS_UNAVAIL); 423 } else if (anslen > sizeof(*buf)) { 424 free(buf); 425#ifdef DEBUG 426 if (statp->options & RES_DEBUG) 427 printf("res_search static buffer too small\n"); 428#endif 429 return (NS_UNAVAIL); 430 } 431 error = getnetanswer(buf, anslen, BYNAME, &ne, ned, statp); 432 free(buf); 433 if (error != 0) { 434 *h_errnop = statp->res_h_errno; 435 return (NS_NOTFOUND); 436 } 437 if (__copy_netent(&ne, nptr, buffer, buflen) != 0) { 438 *errnop = errno; 439 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 440 *h_errnop = statp->res_h_errno; 441 return (NS_RETURN); 442 } 443 *((struct netent **)rval) = nptr; 444 return (NS_SUCCESS); 445} 446 447void 448_setnetdnsent(int stayopen) 449{ 450 res_state statp; 451 452 statp = __res_state(); 453 if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) 454 return; 455 if (stayopen) 456 statp->options |= RES_STAYOPEN | RES_USEVC; 457} 458 459void 460_endnetdnsent(void) 461{ 462 res_state statp; 463 464 statp = __res_state(); 465 statp->options &= ~(RES_STAYOPEN | RES_USEVC); 466 res_nclose(statp); 467} 468