resolv/res_init.c

   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  * 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 #if defined(LIBC_SCCS) && !defined(lint)
  68 static const char sccsid[] = "@(#)res_init.c    8.1 (Berkeley) 6/7/93";
  69 static const char rcsid[] = "$BINDId: res_init.c,v 8.16 2000/05/09 07:10:12 vixie Exp $";
  70 #endif /* LIBC_SCCS and not lint */
  71
  72 #include <ctype.h>
  73 #include <netdb.h>
  74 #include <resolv.h>
  75 #include <stdio.h>
  76 #include <stdio_ext.h>
  77 #include <stdlib.h>
  78 #include <string.h>
  79 #include <unistd.h>
  80 #include <arpa/inet.h>
  81 #include <arpa/nameser.h>
  82 #include <net/if.h>
  83 #include <netinet/in.h>
  84 #include <sys/param.h>
  85 #include <sys/socket.h>
  86 #include <sys/time.h>
  87 #include <sys/types.h>
  88
  89 #include <not-cancel.h>
  90
  91 /* Options.  Should all be left alone. */
  92 #define RESOLVSORT
  93 #define RFC1535
  94 /* #undef DEBUG */
  95
  96 static void res_setoptions (res_state, const char *, const char *)
  97      internal_function;
  98
  99 #ifdef RESOLVSORT
 100 static const char sort_mask_chars[] = "/&";
 101 #define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL)
 102 static u_int32_t net_mask (struct in_addr) __THROW;
 103 #endif
 104
 105 #if !defined(isascii)   /* XXX - could be a function */
 106 # define isascii(c) (!(c & 0200))
 107 #endif
 108
 109 #ifdef _LIBC
 110 unsigned long long int __res_initstamp attribute_hidden;
 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  */
 138 int
 139 res_ninit(res_state statp) {
 140         extern int __res_vinit(res_state, int);
 141
 142         return (__res_vinit(statp, 0));
 143 }
 144 #ifdef _LIBC
 145 libc_hidden_def (__res_ninit)
 146 #endif
 147
 148 /* This function has to be reachable by res_data.c but not publically. */
 149 int
 150 __res_vinit(res_state statp, int preinit) {
 151         register FILE *fp;
 152         register char *cp, **pp;
 153         register int n;
 154         char buf[BUFSIZ];
 155         int nserv = 0;    /* number of nameserver records read from file */
 156 #ifdef _LIBC
 157         int nservall = 0; /* number of NS records read, nserv IPv4 only */
 158 #endif
 159         int haveenv = 0;
 160         int havesearch = 0;
 161 #ifdef RESOLVSORT
 162         int nsort = 0;
 163         char *net;
 164 #endif
 165 #ifndef RFC1535
 166         int dots;
 167 #endif
 168 #ifdef _LIBC
 169         statp->_u._ext.initstamp = __res_initstamp;
 170 #endif
 171
 172         if (!preinit) {
 173                 statp->retrans = RES_TIMEOUT;
 174                 statp->retry = RES_DFLRETRY;
 175                 statp->options = RES_DEFAULT;
 176                 statp->id = res_randomid();
 177         }
 178
 179         statp->nscount = 0;
 180         statp->ndots = 1;
 181         statp->pfcode = 0;
 182         statp->_vcsock = -1;
 183         statp->_flags = 0;
 184         statp->qhook = NULL;
 185         statp->rhook = NULL;
 186         statp->_u._ext.nsinit = 0;
 187         statp->_u._ext.nscount = 0;
 188 #ifdef _LIBC
 189         statp->_u._ext.nscount6 = 0;
 190         for (n = 0; n < MAXNS; n++) {
 191                 statp->_u._ext.nsaddrs[n] = NULL;
 192                 statp->_u._ext.nsmap[n] = MAXNS;
 193         }
 194 #endif
 195
 196         /* Allow user to override the local domain definition */
 197         if ((cp = getenv("LOCALDOMAIN")) != NULL) {
 198                 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 199                 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 200                 haveenv++;
 201
 202                 /*
 203                  * Set search list to be blank-separated strings
 204                  * from rest of env value.  Permits users of LOCALDOMAIN
 205                  * to still have a search list, and anyone to set the
 206                  * one that they want to use as an individual (even more
 207                  * important now that the rfc1535 stuff restricts searches)
 208                  */
 209                 cp = statp->defdname;
 210                 pp = statp->dnsrch;
 211                 *pp++ = cp;
 212                 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 213                         if (*cp == '\n')        /* silly backwards compat */
 214                                 break;
 215                         else if (*cp == ' ' || *cp == '\t') {
 216                                 *cp = 0;
 217                                 n = 1;
 218                         } else if (n) {
 219                                 *pp++ = cp;
 220                                 n = 0;
 221                                 havesearch = 1;
 222                         }
 223                 }
 224                 /* null terminate last domain if there are excess */
 225                 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
 226                         cp++;
 227                 *cp = '\0';
 228                 *pp++ = 0;
 229         }
 230
 231 #define MATCH(line, name) \
 232         (!strncmp(line, name, sizeof(name) - 1) && \
 233         (line[sizeof(name) - 1] == ' ' || \
 234          line[sizeof(name) - 1] == '\t'))
 235
 236         if ((fp = fopen(_PATH_RESCONF, "rce")) != NULL) {
 237             /* No threads use this stream.  */
 238             __fsetlocking (fp, FSETLOCKING_BYCALLER);
 239             /* read the config file */
 240             while (fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
 241                 /* skip comments */
 242                 if (*buf == ';' || *buf == '#')
 243                         continue;
 244                 /* read default domain name */
 245                 if (MATCH(buf, "domain")) {
 246                     if (haveenv)        /* skip if have from environ */
 247                             continue;
 248                     cp = buf + sizeof("domain") - 1;
 249                     while (*cp == ' ' || *cp == '\t')
 250                             cp++;
 251                     if ((*cp == '\0') || (*cp == '\n'))
 252                             continue;
 253                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 254                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 255                     if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
 256                             *cp = '\0';
 257                     havesearch = 0;
 258                     continue;
 259                 }
 260                 /* set search list */
 261                 if (MATCH(buf, "search")) {
 262                     if (haveenv)        /* skip if have from environ */
 263                             continue;
 264                     cp = buf + sizeof("search") - 1;
 265                     while (*cp == ' ' || *cp == '\t')
 266                             cp++;
 267                     if ((*cp == '\0') || (*cp == '\n'))
 268                             continue;
 269                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 270                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 271                     if ((cp = strchr(statp->defdname, '\n')) != NULL)
 272                             *cp = '\0';
 273                     /*
 274                      * Set search list to be blank-separated strings
 275                      * on rest of line.
 276                      */
 277                     cp = statp->defdname;
 278                     pp = statp->dnsrch;
 279                     *pp++ = cp;
 280                     for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 281                             if (*cp == ' ' || *cp == '\t') {
 282                                     *cp = 0;
 283                                     n = 1;
 284                             } else if (n) {
 285                                     *pp++ = cp;
 286                                     n = 0;
 287                             }
 288                     }
 289                     /* null terminate last domain if there are excess */
 290                     while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 291                             cp++;
 292                     *cp = '\0';
 293                     *pp++ = 0;
 294                     havesearch = 1;
 295                     continue;
 296                 }
 297                 /* read nameservers to query */
 298 #ifdef _LIBC
 299                 if (MATCH(buf, "nameserver") && nservall < MAXNS) {
 300 #else
 301                 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
 302 #endif
 303                     struct in_addr a;
 304
 305                     cp = buf + sizeof("nameserver") - 1;
 306                     while (*cp == ' ' || *cp == '\t')
 307                         cp++;
 308                     if ((*cp != '\0') && (*cp != '\n')
 309                         && __inet_aton(cp, &a)) {
 310                         statp->nsaddr_list[nservall].sin_addr = a;
 311                         statp->nsaddr_list[nservall].sin_family = AF_INET;
 312                         statp->nsaddr_list[nservall].sin_port =
 313                                 htons(NAMESERVER_PORT);
 314                         nserv++;
 315 #ifdef _LIBC
 316                         nservall++;
 317                     } else {
 318                         struct in6_addr a6;
 319                         char *el;
 320
 321                         if ((el = strpbrk(cp, " \t\n")) != NULL)
 322                             *el = '\0';
 323                         if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL)
 324                             *el = '\0';
 325                         if ((*cp != '\0') &&
 326                             (inet_pton(AF_INET6, cp, &a6) > 0)) {
 327                             struct sockaddr_in6 *sa6;
 328
 329                             sa6 = malloc(sizeof(*sa6));
 330                             if (sa6 != NULL) {
 331                                 sa6->sin6_family = AF_INET6;
 332                                 sa6->sin6_port = htons(NAMESERVER_PORT);
 333                                 sa6->sin6_flowinfo = 0;
 334                                 sa6->sin6_addr = a6;
 335
 336                                 if (__builtin_expect (el == NULL, 1))
 337                                     sa6->sin6_scope_id = 0;
 338                                 else {
 339                                     int try_numericscope = 1;
 340                                     if (IN6_IS_ADDR_LINKLOCAL (&a6)
 341                                         || IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
 342                                         sa6->sin6_scope_id
 343                                           = if_nametoindex (el + 1);
 344                                         if (sa6->sin6_scope_id != 0)
 345                                             try_numericscope = 0;
 346                                     }
 347
 348                                     if (try_numericscope) {
 349                                         char *end;
 350                                         sa6->sin6_scope_id
 351                                           = (uint32_t) strtoul (el + 1, &end,
 352                                                                 10);
 353                                         if (*end != '\0')
 354                                             sa6->sin6_scope_id = 0;
 355                                     }
 356                                 }
 357
 358                                 statp->_u._ext.nsaddrs[nservall] = sa6;
 359                                 statp->_u._ext.nssocks[nservall] = -1;
 360                                 statp->_u._ext.nsmap[nservall] = MAXNS + 1;
 361                                 nservall++;
 362                             }
 363                         }
 364 #endif
 365                     }
 366                     continue;
 367                 }
 368 #ifdef RESOLVSORT
 369                 if (MATCH(buf, "sortlist")) {
 370                     struct in_addr a;
 371
 372                     cp = buf + sizeof("sortlist") - 1;
 373                     while (nsort < MAXRESOLVSORT) {
 374                         while (*cp == ' ' || *cp == '\t')
 375                             cp++;
 376                         if (*cp == '\0' || *cp == '\n' || *cp == ';')
 377                             break;
 378                         net = cp;
 379                         while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
 380                                isascii(*cp) && !isspace(*cp))
 381                                 cp++;
 382                         n = *cp;
 383                         *cp = 0;
 384                         if (__inet_aton(net, &a)) {
 385                             statp->sort_list[nsort].addr = a;
 386                             if (ISSORTMASK(n)) {
 387                                 *cp++ = n;
 388                                 net = cp;
 389                                 while (*cp && *cp != ';' &&
 390                                         isascii(*cp) && !isspace(*cp))
 391                                     cp++;
 392                                 n = *cp;
 393                                 *cp = 0;
 394                                 if (__inet_aton(net, &a)) {
 395                                     statp->sort_list[nsort].mask = a.s_addr;
 396                                 } else {
 397                                     statp->sort_list[nsort].mask =
 398                                         net_mask(statp->sort_list[nsort].addr);
 399                                 }
 400                             } else {
 401                                 statp->sort_list[nsort].mask =
 402                                     net_mask(statp->sort_list[nsort].addr);
 403                             }
 404                             nsort++;
 405                         }
 406                         *cp = n;
 407                     }
 408                     continue;
 409                 }
 410 #endif
 411                 if (MATCH(buf, "options")) {
 412                     res_setoptions(statp, buf + sizeof("options") - 1, "conf");
 413                     continue;
 414                 }
 415             }
 416             statp->nscount = nservall;
 417 #ifdef _LIBC
 418             if (nservall - nserv > 0) {
 419                 statp->_u._ext.nscount6 = nservall - nserv;
 420                 /* We try IPv6 servers again.  */
 421                 statp->ipv6_unavail = false;
 422             }
 423 #endif
 424 #ifdef RESOLVSORT
 425             statp->nsort = nsort;
 426 #endif
 427             (void) fclose(fp);
 428         }
 429         if (__builtin_expect(statp->nscount == 0, 0)) {
 430             statp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
 431             statp->nsaddr.sin_family = AF_INET;
 432             statp->nsaddr.sin_port = htons(NAMESERVER_PORT);
 433             statp->nscount = 1;
 434         }
 435         if (statp->defdname[0] == 0 &&
 436             __gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
 437             (cp = strchr(buf, '.')) != NULL)
 438                 strcpy(statp->defdname, cp + 1);
 439
 440         /* find components of local domain that might be searched */
 441         if (havesearch == 0) {
 442                 pp = statp->dnsrch;
 443                 *pp++ = statp->defdname;
 444                 *pp = NULL;
 445
 446 #ifndef RFC1535
 447                 dots = 0;
 448                 for (cp = statp->defdname; *cp; cp++)
 449                         dots += (*cp == '.');
 450
 451                 cp = statp->defdname;
 452                 while (pp < statp->dnsrch + MAXDFLSRCH) {
 453                         if (dots < LOCALDOMAINPARTS)
 454                                 break;
 455                         cp = __rawmemchr(cp, '.') + 1;    /* we know there is one */
 456                         *pp++ = cp;
 457                         dots--;
 458                 }
 459                 *pp = NULL;
 460 #ifdef DEBUG
 461                 if (statp->options & RES_DEBUG) {
 462                         printf(";; res_init()... default dnsrch list:\n");
 463                         for (pp = statp->dnsrch; *pp; pp++)
 464                                 printf(";;\t%s\n", *pp);
 465                         printf(";;\t..END..\n");
 466                 }
 467 #endif
 468 #endif /* !RFC1535 */
 469         }
 470
 471         if ((cp = getenv("RES_OPTIONS")) != NULL)
 472                 res_setoptions(statp, cp, "env");
 473         statp->options |= RES_INIT;
 474         return (0);
 475 }
 476
 477 static void
 478 internal_function
 479 res_setoptions(res_state statp, const char *options, const char *source) {
 480         const char *cp = options;
 481         int i;
 482
 483 #ifdef DEBUG
 484         if (statp->options & RES_DEBUG)
 485                 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
 486                        options, source);
 487 #endif
 488         while (*cp) {
 489                 /* skip leading and inner runs of spaces */
 490                 while (*cp == ' ' || *cp == '\t')
 491                         cp++;
 492                 /* search for and process individual options */
 493                 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
 494                         i = atoi(cp + sizeof("ndots:") - 1);
 495                         if (i <= RES_MAXNDOTS)
 496                                 statp->ndots = i;
 497                         else
 498                                 statp->ndots = RES_MAXNDOTS;
 499 #ifdef DEBUG
 500                         if (statp->options & RES_DEBUG)
 501                                 printf(";;\tndots=%d\n", statp->ndots);
 502 #endif
 503                 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
 504                         i = atoi(cp + sizeof("timeout:") - 1);
 505                         if (i <= RES_MAXRETRANS)
 506                                 statp->retrans = i;
 507                         else
 508                                 statp->retrans = RES_MAXRETRANS;
 509                 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
 510                         i = atoi(cp + sizeof("attempts:") - 1);
 511                         if (i <= RES_MAXRETRY)
 512                                 statp->retry = i;
 513                         else
 514                                 statp->retry = RES_MAXRETRY;
 515                 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
 516 #ifdef DEBUG
 517                         if (!(statp->options & RES_DEBUG)) {
 518                                 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
 519                                        options, source);
 520                                 statp->options |= RES_DEBUG;
 521                         }
 522                         printf(";;\tdebug\n");
 523 #endif
 524                 } else {
 525                   static const struct
 526                   {
 527                     char str[22];
 528                     uint8_t len;
 529                     uint8_t clear;
 530                     unsigned long int flag;
 531                   } options[] = {
 532 #define STRnLEN(str) str, sizeof (str) - 1
 533                     { STRnLEN ("inet6"), 0, RES_USE_INET6 },
 534                     { STRnLEN ("ip6-bytestring"), 0, RES_USEBSTRING },
 535                     { STRnLEN ("no-ip6-dotint"), 0, RES_NOIP6DOTINT },
 536                     { STRnLEN ("ip6-dotint"), 1, ~RES_NOIP6DOTINT },
 537                     { STRnLEN ("rotate"), 0, RES_ROTATE },
 538                     { STRnLEN ("no-check-names"), 0, RES_NOCHECKNAME },
 539                     { STRnLEN ("edns0"), 0, RES_USE_EDNS0 },
 540                     { STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP },
 541                     { STRnLEN ("single-request"), 0, RES_SNGLKUP },
 542                     { STRnLEN ("no_tld_query"), 0, RES_NOTLDQUERY },
 543                     { STRnLEN ("no-tld-query"), 0, RES_NOTLDQUERY },
 544                     { STRnLEN ("use-vc"), 0, RES_USEVC }
 545                   };
 546 #define noptions (sizeof (options) / sizeof (options[0]))
 547                   int i;
 548                   for (i = 0; i < noptions; ++i)
 549                     if (strncmp (cp, options[i].str, options[i].len) == 0)
 550                       {
 551                         if (options[i].clear)
 552                           statp->options &= options[i].flag;
 553                         else
 554                           statp->options |= options[i].flag;
 555                         break;
 556                       }
 557                   if (i == noptions) {
 558                     /* XXX - print a warning here? */
 559                   }
 560                 }
 561                 /* skip to next run of spaces */
 562                 while (*cp && *cp != ' ' && *cp != '\t')
 563                         cp++;
 564         }
 565 }
 566
 567 #ifdef RESOLVSORT
 568 /* XXX - should really support CIDR which means explicit masks always. */
 569 static u_int32_t
 570 net_mask(in)            /* XXX - should really use system's version of this */
 571         struct in_addr in;
 572 {
 573         register u_int32_t i = ntohl(in.s_addr);
 574
 575         if (IN_CLASSA(i))
 576                 return (htonl(IN_CLASSA_NET));
 577         else if (IN_CLASSB(i))
 578                 return (htonl(IN_CLASSB_NET));
 579         return (htonl(IN_CLASSC_NET));
 580 }
 581 #endif
 582
 583 u_int
 584 res_randomid(void) {
 585         return 0xffff & __getpid();
 586 }
 587 #ifdef _LIBC
 588 libc_hidden_def (__res_randomid)
 589 #endif
 590
 591
 592 /*
 593  * This routine is for closing the socket if a virtual circuit is used and
 594  * the program wants to close it.  This provides support for endhostent()
 595  * which expects to close the socket.
 596  *
 597  * This routine is not expected to be user visible.
 598  */
 599 void
 600 __res_iclose(res_state statp, bool free_addr) {
 601         int ns;
 602
 603         if (statp->_vcsock >= 0) {
 604                 close_not_cancel_no_status(statp->_vcsock);
 605                 statp->_vcsock = -1;
 606                 statp->_flags &= ~(RES_F_VC | RES_F_CONN);
 607         }
 608 #ifdef _LIBC
 609         for (ns = 0; ns < MAXNS; ns++)
 610 #else
 611         for (ns = 0; ns < statp->_u._ext.nscount; ns++)
 612 #endif
 613                 if (statp->_u._ext.nsaddrs[ns]) {
 614                         if (statp->_u._ext.nssocks[ns] != -1) {
 615                                 close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
 616                                 statp->_u._ext.nssocks[ns] = -1;
 617                         }
 618                         if (free_addr) {
 619                                 free (statp->_u._ext.nsaddrs[ns]);
 620                                 statp->_u._ext.nsaddrs[ns] = NULL;
 621                         }
 622                 }
 623         statp->_u._ext.nsinit = 0;
 624 }
 625 libc_hidden_def (__res_iclose)
 626
 627 void
 628 res_nclose(res_state statp)
 629 {
 630   __res_iclose (statp, true);
 631 }
 632 #ifdef _LIBC
 633 libc_hidden_def (__res_nclose)
 634 #endif
 635
 636 #ifdef _LIBC
 637 # ifdef _LIBC_REENTRANT
 638 /* This is called when a thread is exiting to free resources held in _res.  */
 639 static void __attribute__ ((section ("__libc_thread_freeres_fn")))
 640 res_thread_freeres (void)
 641 {
 642   if (_res.nscount == 0)
 643     /* Never called res_ninit.  */
 644     return;
 645
 646   __res_iclose (&_res, true);           /* Close any VC sockets.  */
 647
 648   /* Make sure we do a full re-initialization the next time.  */
 649   _res.options = 0;
 650 }
 651 text_set_element (__libc_thread_subfreeres, res_thread_freeres);
 652 text_set_element (__libc_subfreeres, res_thread_freeres);
 653 # endif
 654 #endif