1/* 2 * Copyright (c) 1985, 1989, 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 * 3. 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) 2004 by Internet Systems Consortium, Inc. ("ISC") 52 * Portions Copyright (c) 1995-2003 by Internet Software Consortium 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 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 59 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 60 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 61 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 62 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 63 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 64 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 65 * 66 * Internet Systems Consortium, Inc. 67 * 950 Charter Street 68 * Redwood City, CA 94063 69 * <info@isc.org> 70 * http://www.isc.org/ 71 */ 72 73#if defined(LIBC_SCCS) && !defined(lint) 74static const char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93"; 75static const char rcsid[] = "$Id: res_init.c,v 1.5 2007/05/27 16:27:57 tls Exp $"; 76#endif /* LIBC_SCCS and not lint */ 77 78#include <sys/types.h> 79#include <sys/param.h> 80#include <sys/socket.h> 81#include <sys/time.h> 82 83#include <netinet/in.h> 84#include <arpa/inet.h> 85 86#include <ctype.h> 87#include <stdio.h> 88#include <stdlib.h> 89#include <string.h> 90#include <unistd.h> 91 92#include "minires/minires.h" 93#include "omapip/trace_mr.h" 94#include "arpa/nameser.h" 95 96/* Options. Should all be left alone. */ 97#define RESOLVSORT 98#define RFC1535 99#define DEBUG 100 101static void res_setoptions (res_state, const char *, const char *); 102 103#ifdef RESOLVSORT 104static const char sort_mask[] = "/&"; 105#define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL) 106static u_int32_t net_mask (struct in_addr); 107#endif 108 109#if !defined(isascii) /* XXX - could be a function */ 110# define isascii(c) (!(c & 0200)) 111#endif 112 113/* 114 * Resolver state default settings. 115 */ 116 117/* 118 * Set up default settings. If the configuration file exist, the values 119 * there will have precedence. Otherwise, the server address is set to 120 * INADDR_ANY and the default domain name comes from the gethostname(). 121 * 122 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1 123 * rather than INADDR_ANY ("0.0.0.0") as the default name server address 124 * since it was noted that INADDR_ANY actually meant ``the first interface 125 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface, 126 * it had to be "up" in order for you to reach your own name server. It 127 * was later decided that since the recommended practice is to always 128 * install local static routes through 127.0.0.1 for all your network 129 * interfaces, that we could solve this problem without a code change. 130 * 131 * The configuration file should always be used, since it is the only way 132 * to specify a default domain. If you are running a server on your local 133 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1" 134 * in the configuration file. 135 * 136 * Return 0 if completes successfully, -1 on error 137 */ 138extern int minires_vinit(res_state, int); 139 140#if defined (TRACING) 141u_int trace_mr_res_randomid(u_int); 142#endif 143 144int 145res_ninit(res_state statp) { 146 147 return (minires_vinit(statp, 0)); 148} 149 150/* This function has to be reachable by res_data.c but not publically. */ 151int 152minires_vinit(res_state statp, int preinit) { 153 register FILE *fp; 154 register char *cp, **pp; 155 register int n; 156 char buf[BUFSIZ]; 157 int nserv = 0; /* number of nameserver records read from file */ 158 int haveenv = 0; 159 int havesearch = 0; 160#ifdef RESOLVSORT 161 int nsort = 0; 162 char *net; 163#endif 164#ifndef RFC1535 165 int dots; 166#endif 167 168 if (!preinit) { 169 statp->retrans = RES_TIMEOUT; 170 statp->retry = RES_DFLRETRY; 171 statp->options = RES_DEFAULT; 172 statp->id = res_randomid(); 173#if defined (TRACING) 174 statp->id = trace_mr_res_randomid (statp -> id); 175#endif 176 } 177 178#ifdef USELOOPBACK 179 statp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1); 180#else 181 statp->nsaddr.sin_addr.s_addr = INADDR_ANY; 182#endif 183 statp->nsaddr.sin_family = AF_INET; 184 statp->nsaddr.sin_port = htons(NAMESERVER_PORT); 185 statp->nscount = 1; 186 statp->ndots = 1; 187 statp->pfcode = 0; 188 statp->_sock = -1; 189 statp->_flags = 0; 190 statp->qhook = NULL; 191 statp->rhook = NULL; 192 193 /* Allow user to override the local domain definition */ 194 if ((cp = getenv("LOCALDOMAIN")) != NULL) { 195 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); 196 statp->defdname[sizeof(statp->defdname) - 1] = '\0'; 197 haveenv++; 198 199 /* 200 * Set search list to be blank-separated strings 201 * from rest of env value. Permits users of LOCALDOMAIN 202 * to still have a search list, and anyone to set the 203 * one that they want to use as an individual (even more 204 * important now that the rfc1535 stuff restricts searches) 205 */ 206 cp = statp->defdname; 207 pp = statp->dnsrch; 208 *pp++ = cp; 209 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) { 210 if (*cp == '\n') /* silly backwards compat */ 211 break; 212 else if (*cp == ' ' || *cp == '\t') { 213 *cp = 0; 214 n = 1; 215 } else if (n) { 216 *pp++ = cp; 217 n = 0; 218 havesearch = 1; 219 } 220 } 221 /* null terminate last domain if there are excess */ 222 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n') 223 cp++; 224 *cp = '\0'; 225 *pp++ = 0; 226 } 227 228#define MATCH(line, name) \ 229 (!strncmp(line, name, sizeof(name) - 1) && \ 230 (line[sizeof(name) - 1] == ' ' || \ 231 line[sizeof(name) - 1] == '\t')) 232 233 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) { 234 /* read the config file */ 235 while (fgets(buf, sizeof(buf), fp) != NULL) { 236 /* skip comments */ 237 if (*buf == ';' || *buf == '#') 238 continue; 239 /* read default domain name */ 240 if (MATCH(buf, "domain")) { 241 if (haveenv) /* skip if have from environ */ 242 continue; 243 cp = buf + sizeof("domain") - 1; 244 while (*cp == ' ' || *cp == '\t') 245 cp++; 246 if ((*cp == '\0') || (*cp == '\n')) 247 continue; 248 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); 249 statp->defdname[sizeof(statp->defdname) - 1] = '\0'; 250 if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL) 251 *cp = '\0'; 252 havesearch = 0; 253 continue; 254 } 255 /* set search list */ 256 if (MATCH(buf, "search")) { 257 if (haveenv) /* skip if have from environ */ 258 continue; 259 cp = buf + sizeof("search") - 1; 260 while (*cp == ' ' || *cp == '\t') 261 cp++; 262 if ((*cp == '\0') || (*cp == '\n')) 263 continue; 264 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); 265 statp->defdname[sizeof(statp->defdname) - 1] = '\0'; 266 if ((cp = strchr(statp->defdname, '\n')) != NULL) 267 *cp = '\0'; 268 /* 269 * Set search list to be blank-separated strings 270 * on rest of line. 271 */ 272 cp = statp->defdname; 273 pp = statp->dnsrch; 274 *pp++ = cp; 275 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) { 276 if (*cp == ' ' || *cp == '\t') { 277 *cp = 0; 278 n = 1; 279 } else if (n) { 280 *pp++ = cp; 281 n = 0; 282 } 283 } 284 /* null terminate last domain if there are excess */ 285 while (*cp != '\0' && *cp != ' ' && *cp != '\t') 286 cp++; 287 *cp = '\0'; 288 *pp++ = 0; 289 havesearch = 1; 290 continue; 291 } 292 /* read nameservers to query */ 293 if (MATCH(buf, "nameserver") && nserv < MAXNS) { 294 struct in_addr a; 295 296 cp = buf + sizeof("nameserver") - 1; 297 while (*cp == ' ' || *cp == '\t') 298 cp++; 299 if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) { 300 statp->nsaddr_list[nserv].sin_addr = a; 301 statp->nsaddr_list[nserv].sin_family = AF_INET; 302 statp->nsaddr_list[nserv].sin_port = 303 htons(NAMESERVER_PORT); 304 nserv++; 305 } 306 continue; 307 } 308#ifdef RESOLVSORT 309 if (MATCH(buf, "sortlist")) { 310 struct in_addr a; 311 312 cp = buf + sizeof("sortlist") - 1; 313 while (nsort < MAXRESOLVSORT) { 314 while (*cp == ' ' || *cp == '\t') 315 cp++; 316 if (*cp == '\0' || *cp == '\n' || *cp == ';') 317 break; 318 net = cp; 319 while (*cp && !ISSORTMASK(*cp) && *cp != ';' && 320 !isspace((unsigned char)*cp)) 321 cp++; 322 n = *cp; 323 *cp = 0; 324 if (inet_aton(net, &a)) { 325 statp->sort_list[nsort].addr = a; 326 if (ISSORTMASK(n)) { 327 *cp++ = n; 328 net = cp; 329 while (*cp && *cp != ';' && 330 !isspace((unsigned char)*cp)) 331 cp++; 332 n = *cp; 333 *cp = 0; 334 if (inet_aton(net, &a)) { 335 statp->sort_list[nsort].mask = a.s_addr; 336 } else { 337 statp->sort_list[nsort].mask = 338 net_mask(statp->sort_list[nsort].addr); 339 } 340 } else { 341 statp->sort_list[nsort].mask = 342 net_mask(statp->sort_list[nsort].addr); 343 } 344 nsort++; 345 } 346 *cp = n; 347 } 348 continue; 349 } 350#endif 351 if (MATCH(buf, "options")) { 352 res_setoptions(statp, buf + sizeof("options") - 1, "conf"); 353 continue; 354 } 355 } 356 if (nserv > 1) 357 statp->nscount = nserv; 358#ifdef RESOLVSORT 359 statp->nsort = nsort; 360#endif 361 (void) fclose(fp); 362 } 363 if (statp->defdname[0] == 0 && 364 gethostname(buf, sizeof(statp->defdname) - 1) == 0 && 365 (cp = strchr(buf, '.')) != NULL) 366 strcpy(statp->defdname, cp + 1); 367 368 /* find components of local domain that might be searched */ 369 if (havesearch == 0) { 370 pp = statp->dnsrch; 371 *pp++ = statp->defdname; 372 *pp = NULL; 373 374#ifndef RFC1535 375 dots = 0; 376 for (cp = statp->defdname; *cp; cp++) 377 dots += (*cp == '.'); 378 379 cp = statp->defdname; 380 while (pp < statp->dnsrch + MAXDFLSRCH) { 381 if (dots < LOCALDOMAINPARTS) 382 break; 383 cp = strchr(cp, '.') + 1; /* we know there is one */ 384 *pp++ = cp; 385 dots--; 386 } 387 *pp = NULL; 388#ifdef DEBUG 389 if (statp->options & RES_DEBUG) { 390 printf(";; res_init()... default dnsrch list:\n"); 391 for (pp = statp->dnsrch; *pp; pp++) 392 printf(";;\t%s\n", *pp); 393 printf(";;\t..END..\n"); 394 } 395#endif 396#endif /* !RFC1535 */ 397 } 398 399 if ((cp = getenv("RES_OPTIONS")) != NULL) 400 res_setoptions(statp, cp, "env"); 401 statp->options |= RES_INIT; 402 return (0); 403} 404 405static void 406res_setoptions(res_state statp, const char *options, const char *source) { 407 const char *cp = options; 408 int i; 409 410#ifdef DEBUG 411 if (statp->options & RES_DEBUG) 412 printf(";; res_setoptions(\"%s\", \"%s\")...\n", 413 options, source); 414#endif 415 while (*cp) { 416 /* skip leading and inner runs of spaces */ 417 while (*cp == ' ' || *cp == '\t') 418 cp++; 419 /* search for and process individual options */ 420 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) { 421 i = atoi(cp + sizeof("ndots:") - 1); 422 if (i <= RES_MAXNDOTS) 423 statp->ndots = i; 424 else 425 statp->ndots = RES_MAXNDOTS; 426#ifdef DEBUG 427 if (statp->options & RES_DEBUG) 428 printf(";;\tndots=%d\n", statp->ndots); 429#endif 430 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) { 431 i = atoi(cp + sizeof("timeout:") - 1); 432 if (i <= RES_MAXRETRANS) 433 statp->retrans = i; 434 else 435 statp->retrans = RES_MAXRETRANS; 436 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){ 437 i = atoi(cp + sizeof("attempts:") - 1); 438 if (i <= RES_MAXRETRY) 439 statp->retry = i; 440 else 441 statp->retry = RES_MAXRETRY; 442 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) { 443#ifdef DEBUG 444 if (!(statp->options & RES_DEBUG)) { 445 printf(";; res_setoptions(\"%s\", \"%s\")..\n", 446 options, source); 447 statp->options |= RES_DEBUG; 448 } 449 printf(";;\tdebug\n"); 450#endif 451 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) { 452 statp->options |= RES_USE_INET6; 453 } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) { 454 statp->options |= RES_ROTATE; 455 } else if (!strncmp(cp, "no-check-names", 456 sizeof("no-check-names") - 1)) { 457 statp->options |= RES_NOCHECKNAME; 458 } else { 459 /* XXX - print a warning here? */ 460 } 461 /* skip to next run of spaces */ 462 while (*cp && *cp != ' ' && *cp != '\t') 463 cp++; 464 } 465} 466 467#ifdef RESOLVSORT 468/* XXX - should really support CIDR which means explicit masks always. */ 469static u_int32_t 470net_mask(in) /* XXX - should really use system's version of this */ 471 struct in_addr in; 472{ 473 register u_int32_t i = ntohl(in.s_addr); 474 475 if (IN_CLASSA(i)) 476 return (htonl(IN_CLASSA_NET)); 477 else if (IN_CLASSB(i)) 478 return (htonl(IN_CLASSB_NET)); 479 return (htonl(IN_CLASSC_NET)); 480} 481#endif 482 483u_int 484res_randomid(void) { 485 struct timeval now; 486 487 gettimeofday(&now, NULL); 488 return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid())); 489} 490