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 <stdint.h>
  81 #include <arpa/inet.h>
  82 #include <arpa/nameser.h>
  83 #include <net/if.h>
  84 #include <netinet/in.h>
  85 #include <sys/param.h>
  86 #include <sys/socket.h>
  87 #include <sys/time.h>
  88 #include <sys/types.h>
  89
  90 #include <not-cancel.h>
  91
  92 /* Options.  Should all be left alone. */
  93 #define RESOLVSORT
  94 #define RFC1535
  95 /* #undef DEBUG */
  96
  97 static void res_setoptions (res_state, const char *, const char *)
  98      internal_function;
  99
 100 #ifdef RESOLVSORT
 101 static const char sort_mask_chars[] = "/&";
 102 #define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL)
 103 static u_int32_t net_mask (struct in_addr) __THROW;
 104 #endif
 105
 106 #if !defined(isascii)   /* XXX - could be a function */
 107 # define isascii(c) (!(c & 0200))
 108 #endif
 109
 110 #ifdef _LIBC
 111 unsigned long long int __res_initstamp attribute_hidden;
 112 #endif
 113
 114 /*
 115  * Resolver state default settings.
 116  */
 117
 118 /*
 119  * Set up default settings.  If the configuration file exist, the values
 120  * there will have precedence.  Otherwise, the server address is set to
 121  * INADDR_ANY and the default domain name comes from the gethostname().
 122  *
 123  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
 124  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
 125  * since it was noted that INADDR_ANY actually meant ``the first interface
 126  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
 127  * it had to be "up" in order for you to reach your own name server.  It
 128  * was later decided that since the recommended practice is to always
 129  * install local static routes through 127.0.0.1 for all your network
 130  * interfaces, that we could solve this problem without a code change.
 131  *
 132  * The configuration file should always be used, since it is the only way
 133  * to specify a default domain.  If you are running a server on your local
 134  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
 135  * in the configuration file.
 136  *
 137  * Return 0 if completes successfully, -1 on error
 138  */
 139 int
 140 res_ninit(res_state statp) {
 141         extern int __res_vinit(res_state, int);
 142
 143         return (__res_vinit(statp, 0));
 144 }
 145 #ifdef _LIBC
 146 libc_hidden_def (__res_ninit)
 147 #endif
 148
 149 /* This function has to be reachable by res_data.c but not publically. */
 150 int
 151 __res_vinit(res_state statp, int preinit) {
 152         FILE *fp;
 153         char *cp, **pp;
 154         int n;
 155         char buf[BUFSIZ];
 156         int nserv = 0;    /* number of IPv4 nameservers read from file */
 157 #ifdef _LIBC
 158         int nservall = 0; /* number of (IPv4 + IPV6) nameservers read from file */
 159 #endif
 160         int haveenv = 0;
 161         int havesearch = 0;
 162 #ifdef RESOLVSORT
 163         int nsort = 0;
 164         char *net;
 165 #endif
 166 #ifndef RFC1535
 167         int dots;
 168 #endif
 169 #ifdef _LIBC
 170         statp->_u._ext.initstamp = __res_initstamp;
 171 #endif
 172
 173         if (!preinit) {
 174                 statp->retrans = RES_TIMEOUT;
 175                 statp->retry = RES_DFLRETRY;
 176                 statp->options = RES_DEFAULT;
 177                 statp->id = res_randomid();
 178         }
 179
 180         statp->nscount = 0;
 181         statp->ndots = 1;
 182         statp->pfcode = 0;
 183         statp->_vcsock = -1;
 184         statp->_flags = 0;
 185         statp->qhook = NULL;
 186         statp->rhook = NULL;
 187         statp->_u._ext.nsinit = 0;
 188         statp->_u._ext.nscount = 0;
 189 #ifdef _LIBC
 190         statp->_u._ext.nscount6 = 0;
 191         for (n = 0; n < MAXNS; n++) {
 192                 statp->_u._ext.nsaddrs[n] = NULL;
 193                 statp->_u._ext.nsmap[n] = MAXNS;
 194         }
 195 #endif
 196
 197         /* Allow user to override the local domain definition */
 198         if ((cp = getenv("LOCALDOMAIN")) != NULL) {
 199                 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 200                 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 201                 haveenv++;
 202
 203                 /*
 204                  * Set search list to be blank-separated strings
 205                  * from rest of env value.  Permits users of LOCALDOMAIN
 206                  * to still have a search list, and anyone to set the
 207                  * one that they want to use as an individual (even more
 208                  * important now that the rfc1535 stuff restricts searches)
 209                  */
 210                 cp = statp->defdname;
 211                 pp = statp->dnsrch;
 212                 *pp++ = cp;
 213                 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 214                         if (*cp == '\n')        /* silly backwards compat */
 215                                 break;
 216                         else if (*cp == ' ' || *cp == '\t') {
 217                                 *cp = 0;
 218                                 n = 1;
 219                         } else if (n) {
 220                                 *pp++ = cp;
 221                                 n = 0;
 222                                 havesearch = 1;
 223                         }
 224                 }
 225                 /* null terminate last domain if there are excess */
 226                 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
 227                         cp++;
 228                 *cp = '\0';
 229                 *pp++ = 0;
 230         }
 231
 232 #define MATCH(line, name) \
 233         (!strncmp(line, name, sizeof(name) - 1) && \
 234         (line[sizeof(name) - 1] == ' ' || \
 235          line[sizeof(name) - 1] == '\t'))
 236
 237         if ((fp = fopen(_PATH_RESCONF, "rce")) != NULL) {
 238             /* No threads use this stream.  */
 239             __fsetlocking (fp, FSETLOCKING_BYCALLER);
 240             /* read the config file */
 241             while (__fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
 242                 /* skip comments */
 243                 if (*buf == ';' || *buf == '#')
 244                         continue;
 245                 /* read default domain name */
 246                 if (MATCH(buf, "domain")) {
 247                     if (haveenv)        /* skip if have from environ */
 248                             continue;
 249                     cp = buf + sizeof("domain") - 1;
 250                     while (*cp == ' ' || *cp == '\t')
 251                             cp++;
 252                     if ((*cp == '\0') || (*cp == '\n'))
 253                             continue;
 254                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 255                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 256                     if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
 257                             *cp = '\0';
 258                     havesearch = 0;
 259                     continue;
 260                 }
 261                 /* set search list */
 262                 if (MATCH(buf, "search")) {
 263                     if (haveenv)        /* skip if have from environ */
 264                             continue;
 265                     cp = buf + sizeof("search") - 1;
 266                     while (*cp == ' ' || *cp == '\t')
 267                             cp++;
 268                     if ((*cp == '\0') || (*cp == '\n'))
 269                             continue;
 270                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 271                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 272                     if ((cp = strchr(statp->defdname, '\n')) != NULL)
 273                             *cp = '\0';
 274                     /*
 275                      * Set search list to be blank-separated strings
 276                      * on rest of line.
 277                      */
 278                     cp = statp->defdname;
 279                     pp = statp->dnsrch;
 280                     *pp++ = cp;
 281                     for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 282                             if (*cp == ' ' || *cp == '\t') {
 283                                     *cp = 0;
 284                                     n = 1;
 285                             } else if (n) {
 286                                     *pp++ = cp;
 287                                     n = 0;
 288                             }
 289                     }
 290                     /* null terminate last domain if there are excess */
 291                     while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 292                             cp++;
 293                     *cp = '\0';
 294                     *pp++ = 0;
 295                     havesearch = 1;
 296                     continue;
 297                 }
 298                 /* read nameservers to query */
 299 #ifdef _LIBC
 300                 if (MATCH(buf, "nameserver") && nservall < MAXNS) {
 301 #else
 302                 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
 303 #endif
 304                     struct in_addr a;
 305
 306                     cp = buf + sizeof("nameserver") - 1;
 307                     while (*cp == ' ' || *cp == '\t')
 308                         cp++;
 309                     if ((*cp != '\0') && (*cp != '\n')
 310                         && __inet_aton(cp, &a)) {
 311                         statp->nsaddr_list[nservall].sin_addr = a;
 312                         statp->nsaddr_list[nservall].sin_family = AF_INET;
 313                         statp->nsaddr_list[nservall].sin_port =
 314                                 htons(NAMESERVER_PORT);
 315                         nserv++;
 316 #ifdef _LIBC
 317                         nservall++;
 318                     } else {
 319                         struct in6_addr a6;
 320                         char *el;
 321
 322                         if ((el = strpbrk(cp, " \t\n")) != NULL)
 323                             *el = '\0';
 324                         if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL)
 325                             *el = '\0';
 326                         if ((*cp != '\0') &&
 327                             (__inet_pton(AF_INET6, cp, &a6) > 0)) {
 328                             struct sockaddr_in6 *sa6;
 329
 330                             sa6 = malloc(sizeof(*sa6));
 331                             if (sa6 != NULL) {
 332                                 sa6->sin6_family = AF_INET6;
 333                                 sa6->sin6_port = htons(NAMESERVER_PORT);
 334                                 sa6->sin6_flowinfo = 0;
 335                                 sa6->sin6_addr = a6;
 336
 337                                 if (__glibc_likely (el == NULL))
 338                                     sa6->sin6_scope_id = 0;
 339                                 else {
 340                                     int try_numericscope = 1;
 341                                     if (IN6_IS_ADDR_LINKLOCAL (&a6)
 342                                         || IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
 343                                         sa6->sin6_scope_id
 344                                           = __if_nametoindex (el + 1);
 345                                         if (sa6->sin6_scope_id != 0)
 346                                             try_numericscope = 0;
 347                                     }
 348
 349                                     if (try_numericscope) {
 350                                         char *end;
 351                                         sa6->sin6_scope_id
 352                                           = (uint32_t) strtoul (el + 1, &end,
 353                                                                 10);
 354                                         if (*end != '\0')
 355                                             sa6->sin6_scope_id = 0;
 356                                     }
 357                                 }
 358
 359                                 statp->_u._ext.nsaddrs[nservall] = sa6;
 360                                 statp->_u._ext.nssocks[nservall] = -1;
 361                                 statp->_u._ext.nsmap[nservall] = MAXNS + 1;
 362                                 nservall++;
 363                             }
 364                         }
 365 #endif
 366                     }
 367                     continue;
 368                 }
 369 #ifdef RESOLVSORT
 370                 if (MATCH(buf, "sortlist")) {
 371                     struct in_addr a;
 372
 373                     cp = buf + sizeof("sortlist") - 1;
 374                     while (nsort < MAXRESOLVSORT) {
 375                         while (*cp == ' ' || *cp == '\t')
 376                             cp++;
 377                         if (*cp == '\0' || *cp == '\n' || *cp == ';')
 378                             break;
 379                         net = cp;
 380                         while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
 381                                isascii(*cp) && !isspace(*cp))
 382                                 cp++;
 383                         n = *cp;
 384                         *cp = 0;
 385                         if (__inet_aton(net, &a)) {
 386                             statp->sort_list[nsort].addr = a;
 387                             if (ISSORTMASK(n)) {
 388                                 *cp++ = n;
 389                                 net = cp;
 390                                 while (*cp && *cp != ';' &&
 391                                         isascii(*cp) && !isspace(*cp))
 392                                     cp++;
 393                                 n = *cp;
 394                                 *cp = 0;
 395                                 if (__inet_aton(net, &a)) {
 396                                     statp->sort_list[nsort].mask = a.s_addr;
 397                                 } else {
 398                                     statp->sort_list[nsort].mask =
 399                                         net_mask(statp->sort_list[nsort].addr);
 400                                 }
 401                             } else {
 402                                 statp->sort_list[nsort].mask =
 403                                     net_mask(statp->sort_list[nsort].addr);
 404                             }
 405                             nsort++;
 406                         }
 407                         *cp = n;
 408                     }
 409                     continue;
 410                 }
 411 #endif
 412                 if (MATCH(buf, "options")) {
 413                     res_setoptions(statp, buf + sizeof("options") - 1, "conf");
 414                     continue;
 415                 }
 416             }
 417             statp->nscount = nservall;
 418 #ifdef _LIBC
 419             if (nservall - nserv > 0) {
 420                 statp->_u._ext.nscount6 = nservall - nserv;
 421                 /* We try IPv6 servers again.  */
 422                 statp->ipv6_unavail = false;
 423             }
 424 #endif
 425 #ifdef RESOLVSORT
 426             statp->nsort = nsort;
 427 #endif
 428             (void) fclose(fp);
 429         }
 430         if (__builtin_expect(statp->nscount == 0, 0)) {
 431             statp->nsaddr.sin_addr = __inet_makeaddr(IN_LOOPBACKNET, 1);
 432             statp->nsaddr.sin_family = AF_INET;
 433             statp->nsaddr.sin_port = htons(NAMESERVER_PORT);
 434             statp->nscount = 1;
 435         }
 436         if (statp->defdname[0] == 0 &&
 437             __gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
 438             (cp = strchr(buf, '.')) != NULL)
 439                 strcpy(statp->defdname, cp + 1);
 440
 441         /* find components of local domain that might be searched */
 442         if (havesearch == 0) {
 443                 pp = statp->dnsrch;
 444                 *pp++ = statp->defdname;
 445                 *pp = NULL;
 446
 447 #ifndef RFC1535
 448                 dots = 0;
 449                 for (cp = statp->defdname; *cp; cp++)
 450                         dots += (*cp == '.');
 451
 452                 cp = statp->defdname;
 453                 while (pp < statp->dnsrch + MAXDFLSRCH) {
 454                         if (dots < LOCALDOMAINPARTS)
 455                                 break;
 456                         cp = __rawmemchr(cp, '.') + 1;    /* we know there is one */
 457                         *pp++ = cp;
 458                         dots--;
 459                 }
 460                 *pp = NULL;
 461 #ifdef DEBUG
 462                 if (statp->options & RES_DEBUG) {
 463                         printf(";; res_init()... default dnsrch list:\n");
 464                         for (pp = statp->dnsrch; *pp; pp++)
 465                                 printf(";;\t%s\n", *pp);
 466                         printf(";;\t..END..\n");
 467                 }
 468 #endif
 469 #endif /* !RFC1535 */
 470         }
 471
 472         if ((cp = getenv("RES_OPTIONS")) != NULL)
 473                 res_setoptions(statp, cp, "env");
 474         statp->options |= RES_INIT;
 475         return (0);
 476 }
 477
 478 static void
 479 internal_function
 480 res_setoptions(res_state statp, const char *options, const char *source) {
 481         const char *cp = options;
 482         int i;
 483
 484 #ifdef DEBUG
 485         if (statp->options & RES_DEBUG)
 486                 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
 487                        options, source);
 488 #endif
 489         while (*cp) {
 490                 /* skip leading and inner runs of spaces */
 491                 while (*cp == ' ' || *cp == '\t')
 492                         cp++;
 493                 /* search for and process individual options */
 494                 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
 495                         i = atoi(cp + sizeof("ndots:") - 1);
 496                         if (i <= RES_MAXNDOTS)
 497                                 statp->ndots = i;
 498                         else
 499                                 statp->ndots = RES_MAXNDOTS;
 500 #ifdef DEBUG
 501                         if (statp->options & RES_DEBUG)
 502                                 printf(";;\tndots=%d\n", statp->ndots);
 503 #endif
 504                 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
 505                         i = atoi(cp + sizeof("timeout:") - 1);
 506                         if (i <= RES_MAXRETRANS)
 507                                 statp->retrans = i;
 508                         else
 509                                 statp->retrans = RES_MAXRETRANS;
 510                 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
 511                         i = atoi(cp + sizeof("attempts:") - 1);
 512                         if (i <= RES_MAXRETRY)
 513                                 statp->retry = i;
 514                         else
 515                                 statp->retry = RES_MAXRETRY;
 516                 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
 517 #ifdef DEBUG
 518                         if (!(statp->options & RES_DEBUG)) {
 519                                 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
 520                                        options, source);
 521                                 statp->options |= RES_DEBUG;
 522                         }
 523                         printf(";;\tdebug\n");
 524 #endif
 525                 } else {
 526                   static const struct
 527                   {
 528                     char str[22];
 529                     uint8_t len;
 530                     uint8_t clear;
 531                     unsigned long int flag;
 532                   } options[] = {
 533 #define STRnLEN(str) str, sizeof (str) - 1
 534                     { STRnLEN ("inet6"), 0, RES_USE_INET6 },
 535                     { STRnLEN ("ip6-bytestring"), 0, RES_USEBSTRING },
 536                     { STRnLEN ("no-ip6-dotint"), 0, RES_NOIP6DOTINT },
 537                     { STRnLEN ("ip6-dotint"), 1, ~RES_NOIP6DOTINT },
 538                     { STRnLEN ("rotate"), 0, RES_ROTATE },
 539                     { STRnLEN ("no-check-names"), 0, RES_NOCHECKNAME },
 540                     { STRnLEN ("edns0"), 0, RES_USE_EDNS0 },
 541                     { STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP },
 542                     { STRnLEN ("single-request"), 0, RES_SNGLKUP },
 543                     { STRnLEN ("no_tld_query"), 0, RES_NOTLDQUERY },
 544                     { STRnLEN ("no-tld-query"), 0, RES_NOTLDQUERY },
 545                     { STRnLEN ("use-vc"), 0, RES_USEVC }
 546                   };
 547 #define noptions (sizeof (options) / sizeof (options[0]))
 548                   int i;
 549                   for (i = 0; i < noptions; ++i)
 550                     if (strncmp (cp, options[i].str, options[i].len) == 0)
 551                       {
 552                         if (options[i].clear)
 553                           statp->options &= options[i].flag;
 554                         else
 555                           statp->options |= options[i].flag;
 556                         break;
 557                       }
 558                   if (i == noptions) {
 559                     /* XXX - print a warning here? */
 560                   }
 561                 }
 562                 /* skip to next run of spaces */
 563                 while (*cp && *cp != ' ' && *cp != '\t')
 564                         cp++;
 565         }
 566 }
 567
 568 #ifdef RESOLVSORT
 569 /* XXX - should really support CIDR which means explicit masks always. */
 570 static u_int32_t
 571 net_mask(in)            /* XXX - should really use system's version of this */
 572         struct in_addr in;
 573 {
 574         u_int32_t i = ntohl(in.s_addr);
 575
 576         if (IN_CLASSA(i))
 577                 return (htonl(IN_CLASSA_NET));
 578         else if (IN_CLASSB(i))
 579                 return (htonl(IN_CLASSB_NET));
 580         return (htonl(IN_CLASSC_NET));
 581 }
 582 #endif
 583
 584 u_int
 585 res_randomid(void) {
 586         return 0xffff & __getpid();
 587 }
 588 #ifdef _LIBC
 589 libc_hidden_def (__res_randomid)
 590 #endif
 591
 592
 593 /*
 594  * This routine is for closing the socket if a virtual circuit is used and
 595  * the program wants to close it.  This provides support for endhostent()
 596  * which expects to close the socket.
 597  *
 598  * This routine is not expected to be user visible.
 599  */
 600 void
 601 __res_iclose(res_state statp, bool free_addr) {
 602         int ns;
 603
 604         if (statp->_vcsock >= 0) {
 605                 close_not_cancel_no_status(statp->_vcsock);
 606                 statp->_vcsock = -1;
 607                 statp->_flags &= ~(RES_F_VC | RES_F_CONN);
 608         }
 609 #ifdef _LIBC
 610         for (ns = 0; ns < MAXNS; ns++)
 611 #else
 612         for (ns = 0; ns < statp->_u._ext.nscount; ns++)
 613 #endif
 614                 if (statp->_u._ext.nsaddrs[ns]) {
 615                         if (statp->_u._ext.nssocks[ns] != -1) {
 616                                 close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
 617                                 statp->_u._ext.nssocks[ns] = -1;
 618                         }
 619                         if (free_addr) {
 620                                 free (statp->_u._ext.nsaddrs[ns]);
 621                                 statp->_u._ext.nsaddrs[ns] = NULL;
 622                         }
 623                 }
 624         if (free_addr)
 625                 statp->_u._ext.nsinit = 0;
 626 }
 627 libc_hidden_def (__res_iclose)
 628
 629 void
 630 res_nclose(res_state statp)
 631 {
 632   __res_iclose (statp, true);
 633 }
 634 #ifdef _LIBC
 635 libc_hidden_def (__res_nclose)
 636 #endif
 637
 638 #ifdef _LIBC
 639 # ifdef _LIBC_REENTRANT
 640 /* This is called when a thread is exiting to free resources held in _res.  */
 641 static void __attribute__ ((section ("__libc_thread_freeres_fn")))
 642 res_thread_freeres (void)
 643 {
 644   if (_res.nscount == 0)
 645     /* Never called res_ninit.  */
 646     return;
 647
 648   __res_iclose (&_res, true);           /* Close any VC sockets.  */
 649
 650   /* Make sure we do a full re-initialization the next time.  */
 651   _res.options = 0;
 652 }
 653 text_set_element (__libc_thread_subfreeres, res_thread_freeres);
 654 text_set_element (__libc_subfreeres, res_thread_freeres);
 655 # endif
 656 #endif