lib/libc/resolv/res_init.c

   1 /*      $NetBSD: res_init.c,v 1.26 2012/09/09 18:04:26 christos Exp $   */
   2
   3 /*
   4  * Copyright (c) 1985, 1989, 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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 /*
  37  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  38  *
  39  * Permission to use, copy, modify, and distribute this software for any
  40  * purpose with or without fee is hereby granted, provided that the above
  41  * copyright notice and this permission notice appear in all copies, and that
  42  * the name of Digital Equipment Corporation not be used in advertising or
  43  * publicity pertaining to distribution of the document or software without
  44  * specific, written prior permission.
  45  *
  46  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  47  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  48  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  49  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  50  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  51  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  52  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  53  * SOFTWARE.
  54  */
  55
  56 /*
  57  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  58  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  59  *
  60  * Permission to use, copy, modify, and distribute this software for any
  61  * purpose with or without fee is hereby granted, provided that the above
  62  * copyright notice and this permission notice appear in all copies.
  63  *
  64  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  65  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  66  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  67  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  68  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  69  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  70  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  71  */
  72
  73 #include <sys/cdefs.h>
  74 #if defined(LIBC_SCCS) && !defined(lint)
  75 #ifdef notdef
  76 static const char sccsid[] = "@(#)res_init.c    8.1 (Berkeley) 6/7/93";
  77 static const char rcsid[] = "Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp";
  78 #else
  79 __RCSID("$NetBSD: res_init.c,v 1.26 2012/09/09 18:04:26 christos Exp $");
  80 #endif
  81 #endif /* LIBC_SCCS and not lint */
  82
  83 #include "port_before.h"
  84
  85 #include "namespace.h"
  86 #include <sys/types.h>
  87 #include <sys/param.h>
  88 #include <sys/socket.h>
  89 #include <sys/stat.h>
  90 #include <sys/time.h>
  91 #ifndef __minix
  92 #include <sys/event.h>
  93 #endif /* !__minix */
  94
  95 #include <netinet/in.h>
  96 #include <arpa/inet.h>
  97 #include <arpa/nameser.h>
  98
  99 #include <ctype.h>
 100 #include <stdio.h>
 101 #include <stdlib.h>
 102 #include <string.h>
 103 #include <unistd.h>
 104 #include <fcntl.h>
 105 #include <netdb.h>
 106
 107 #define HAVE_MD5
 108 #include <md5.h>
 109
 110 #ifndef HAVE_MD5
 111 # include "../dst/md5.h"
 112 #else
 113 # ifdef SOLARIS2
 114 #  include <sys/md5.h>
 115 # endif
 116 #endif
 117 #ifndef _MD5_H_
 118 # define _MD5_H_ 1      /*%< make sure we do not include rsaref md5.h file */
 119 #endif
 120
 121 #include "port_after.h"
 122
 123 #if 0
 124 #ifdef __weak_alias
 125 __weak_alias(res_ninit,_res_ninit)
 126 __weak_alias(res_randomid,__res_randomid)
 127 __weak_alias(res_nclose,_res_nclose)
 128 __weak_alias(res_ndestroy,_res_ndestroy)
 129 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
 130 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
 131 __weak_alias(res_getservers,__res_getservers)
 132 __weak_alias(res_setservers,__res_setservers)
 133 #endif
 134 #endif
 135
 136
 137 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
 138 #include <resolv.h>
 139
 140 #include "res_private.h"
 141
 142 #define RESOLVSORT
 143 /*% Options.  Should all be left alone. */
 144 #ifndef DEBUG
 145 #define DEBUG
 146 #endif
 147
 148 #ifdef SOLARIS2
 149 #include <sys/systeminfo.h>
 150 #endif
 151
 152 static void res_setoptions(res_state, const char *, const char *);
 153
 154 #ifdef RESOLVSORT
 155 static const char sort_mask[] = "/&";
 156 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
 157 static uint32_t net_mask(struct in_addr);
 158 #endif
 159
 160 #if !defined(isascii)   /*%< XXX - could be a function */
 161 # define isascii(c) (!(c & 0200))
 162 #endif
 163
 164 static struct timespec __res_conf_time;
 165 static const struct timespec ts = { 0, 0 };
 166
 167 /*
 168  * Resolver state default settings.
 169  */
 170
 171 /*%
 172  * Set up default settings.  If the configuration file exist, the values
 173  * there will have precedence.  Otherwise, the server address is set to
 174  * INADDR_ANY and the default domain name comes from the gethostname().
 175  *
 176  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
 177  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
 178  * since it was noted that INADDR_ANY actually meant ``the first interface
 179  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
 180  * it had to be "up" in order for you to reach your own name server.  It
 181  * was later decided that since the recommended practice is to always
 182  * install local static routes through 127.0.0.1 for all your network
 183  * interfaces, that we could solve this problem without a code change.
 184  *
 185  * The configuration file should always be used, since it is the only way
 186  * to specify a default domain.  If you are running a server on your local
 187  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
 188  * in the configuration file.
 189  *
 190  * Return 0 if completes successfully, -1 on error
 191  */
 192 int
 193 res_ninit(res_state statp) {
 194         return (__res_vinit(statp, 0));
 195 }
 196
 197 /*% This function has to be reachable by res_data.c but not publically. */
 198 int
 199 __res_vinit(res_state statp, int preinit) {
 200         register FILE *fp;
 201         register char *cp, **pp;
 202         register int n;
 203         char buf[BUFSIZ];
 204         int nserv = 0;    /*%< number of nameserver records read from file */
 205         int haveenv = 0;
 206         int havesearch = 0;
 207 #ifdef RESOLVSORT
 208         int nsort = 0;
 209         char *net;
 210 #endif
 211         int dots;
 212         union res_sockaddr_union u[2];
 213         int maxns = MAXNS;
 214
 215         RES_SET_H_ERRNO(statp, 0);
 216
 217         if ((statp->options & RES_INIT) != 0U)
 218                 res_ndestroy(statp);
 219
 220         if (!preinit) {
 221                 statp->retrans = RES_TIMEOUT;
 222                 statp->retry = RES_DFLRETRY;
 223                 statp->options = RES_DEFAULT;
 224         }
 225         statp->_rnd = malloc(16);
 226         res_rndinit(statp);
 227         statp->id = res_nrandomid(statp);
 228
 229         memset(u, 0, sizeof(u));
 230 #ifdef USELOOPBACK
 231         u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
 232 #else
 233         u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
 234 #endif
 235         u[nserv].sin.sin_family = AF_INET;
 236         u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
 237 #ifdef HAVE_SA_LEN
 238         u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
 239 #endif
 240         nserv++;
 241 #ifdef HAS_INET6_STRUCTS
 242 #ifdef USELOOPBACK
 243         u[nserv].sin6.sin6_addr = in6addr_loopback;
 244 #else
 245         u[nserv].sin6.sin6_addr = in6addr_any;
 246 #endif
 247         u[nserv].sin6.sin6_family = AF_INET6;
 248         u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
 249 #ifdef HAVE_SA_LEN
 250         u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
 251 #endif
 252         nserv++;
 253 #endif
 254         statp->nscount = 0;
 255         statp->ndots = 1;
 256         statp->pfcode = 0;
 257         statp->_vcsock = -1;
 258         statp->_flags = 0;
 259         statp->qhook = NULL;
 260         statp->rhook = NULL;
 261         statp->_u._ext.nscount = 0;
 262         statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
 263         if (statp->_u._ext.ext != NULL) {
 264                 memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
 265                 statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
 266                 strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
 267                 strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
 268         } else {
 269                 /*
 270                  * Historically res_init() rarely, if at all, failed.
 271                  * Examples and applications exist which do not check
 272                  * our return code.  Furthermore several applications
 273                  * simply call us to get the systems domainname.  So
 274                  * rather then immediately fail here we store the
 275                  * failure, which is returned later, in h_errno.  And
 276                  * prevent the collection of 'nameserver' information
 277                  * by setting maxns to 0.  Thus applications that fail
 278                  * to check our return code wont be able to make
 279                  * queries anyhow.
 280                  */
 281                 RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
 282                 maxns = 0;
 283         }
 284 #ifdef RESOLVSORT
 285         statp->nsort = 0;
 286 #endif
 287         res_setservers(statp, u, nserv);
 288
 289 #ifdef  SOLARIS2
 290         /*
 291          * The old libresolv derived the defaultdomain from NIS/NIS+.
 292          * We want to keep this behaviour
 293          */
 294         {
 295                 char buf[sizeof(statp->defdname)], *cp;
 296                 int ret;
 297
 298                 if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
 299                         (unsigned int)ret <= sizeof(buf)) {
 300                         if (buf[0] == '+')
 301                                 buf[0] = '.';
 302                         cp = strchr(buf, '.');
 303                         cp = (cp == NULL) ? buf : (cp + 1);
 304                         (void)strlcpy(statp->defdname, cp,
 305                             sizeof(statp->defdname));
 306                 }
 307         }
 308 #endif  /* SOLARIS2 */
 309
 310         /* Allow user to override the local domain definition */
 311         if ((cp = getenv("LOCALDOMAIN")) != NULL) {
 312                 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 313                 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 314                 haveenv++;
 315
 316                 /*
 317                  * Set search list to be blank-separated strings
 318                  * from rest of env value.  Permits users of LOCALDOMAIN
 319                  * to still have a search list, and anyone to set the
 320                  * one that they want to use as an individual (even more
 321                  * important now that the rfc1535 stuff restricts searches)
 322                  */
 323                 cp = statp->defdname;
 324                 pp = statp->dnsrch;
 325                 *pp++ = cp;
 326                 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 327                         if (*cp == '\n')        /*%< silly backwards compat */
 328                                 break;
 329                         else if (*cp == ' ' || *cp == '\t') {
 330                                 *cp = 0;
 331                                 n = 1;
 332                         } else if (n) {
 333                                 *pp++ = cp;
 334                                 n = 0;
 335                                 havesearch = 1;
 336                         }
 337                 }
 338                 /* null terminate last domain if there are excess */
 339                 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
 340                         cp++;
 341                 *cp = '\0';
 342                 *pp++ = 0;
 343         }
 344
 345 #define MATCH(line, name) \
 346         (!strncmp(line, name, sizeof(name) - 1) && \
 347         (line[sizeof(name) - 1] == ' ' || \
 348          line[sizeof(name) - 1] == '\t'))
 349
 350         nserv = 0;
 351         if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
 352             struct stat st;
 353 #ifndef __minix
 354             struct kevent kc;
 355 #endif /* !__minix */
 356
 357             /* read the config file */
 358             while (fgets(buf, (int)sizeof(buf), fp) != NULL) {
 359                 /* skip comments */
 360                 if (*buf == ';' || *buf == '#')
 361                         continue;
 362                 /* read default domain name */
 363                 if (MATCH(buf, "domain")) {
 364                     if (haveenv)        /*%< skip if have from environ */
 365                             continue;
 366                     cp = buf + sizeof("domain") - 1;
 367                     while (*cp == ' ' || *cp == '\t')
 368                             cp++;
 369                     if ((*cp == '\0') || (*cp == '\n'))
 370                             continue;
 371                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 372                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 373                     if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
 374                             *cp = '\0';
 375                     havesearch = 0;
 376                     continue;
 377                 }
 378                 /* set search list */
 379                 if (MATCH(buf, "search")) {
 380                     if (haveenv)        /*%< skip if have from environ */
 381                             continue;
 382                     cp = buf + sizeof("search") - 1;
 383                     while (*cp == ' ' || *cp == '\t')
 384                             cp++;
 385                     if ((*cp == '\0') || (*cp == '\n'))
 386                             continue;
 387                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 388                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 389                     if ((cp = strchr(statp->defdname, '\n')) != NULL)
 390                             *cp = '\0';
 391                     /*
 392                      * Set search list to be blank-separated strings
 393                      * on rest of line.
 394                      */
 395                     cp = statp->defdname;
 396                     pp = statp->dnsrch;
 397                     *pp++ = cp;
 398                     for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 399                             if (*cp == ' ' || *cp == '\t') {
 400                                     *cp = 0;
 401                                     n = 1;
 402                             } else if (n) {
 403                                     *pp++ = cp;
 404                                     n = 0;
 405                             }
 406                     }
 407                     /* null terminate last domain if there are excess */
 408                     while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 409                             cp++;
 410                     *cp = '\0';
 411                     *pp++ = 0;
 412                     havesearch = 1;
 413                     continue;
 414                 }
 415                 /* read nameservers to query */
 416                 if (MATCH(buf, "nameserver") && nserv < maxns) {
 417                     struct addrinfo hints, *ai;
 418                     char sbuf[NI_MAXSERV];
 419                     const size_t minsiz =
 420                         sizeof(statp->_u._ext.ext->nsaddrs[0]);
 421
 422                     cp = buf + sizeof("nameserver") - 1;
 423                     while (*cp == ' ' || *cp == '\t')
 424                         cp++;
 425                     cp[strcspn(cp, ";# \t\n")] = '\0';
 426                     if ((*cp != '\0') && (*cp != '\n')) {
 427                         memset(&hints, 0, sizeof(hints));
 428                         hints.ai_family = PF_UNSPEC;
 429                         hints.ai_socktype = SOCK_DGRAM; /*dummy*/
 430                         hints.ai_flags = AI_NUMERICHOST;
 431                         sprintf(sbuf, "%u", NAMESERVER_PORT);
 432                         if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
 433                             ai->ai_addrlen <= minsiz) {
 434                             if (statp->_u._ext.ext != NULL) {
 435                                 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
 436                                     ai->ai_addr, ai->ai_addrlen);
 437                             }
 438                             if (ai->ai_addrlen <=
 439                                 sizeof(statp->nsaddr_list[nserv])) {
 440                                 memcpy(&statp->nsaddr_list[nserv],
 441                                     ai->ai_addr, ai->ai_addrlen);
 442                             } else
 443                                 statp->nsaddr_list[nserv].sin_family = 0;
 444                             freeaddrinfo(ai);
 445                             nserv++;
 446                         }
 447                     }
 448                     continue;
 449                 }
 450 #ifdef RESOLVSORT
 451                 if (MATCH(buf, "sortlist")) {
 452                     struct in_addr a;
 453
 454                     cp = buf + sizeof("sortlist") - 1;
 455                     while (nsort < MAXRESOLVSORT) {
 456                         while (*cp == ' ' || *cp == '\t')
 457                             cp++;
 458                         if (*cp == '\0' || *cp == '\n' || *cp == ';')
 459                             break;
 460                         net = cp;
 461                         while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
 462                                isascii(*cp) && !isspace((unsigned char)*cp))
 463                                 cp++;
 464                         n = *cp;
 465                         *cp = 0;
 466                         if (inet_aton(net, &a)) {
 467                             statp->sort_list[nsort].addr = a;
 468                             if (ISSORTMASK(n)) {
 469                                 *cp++ = n;
 470                                 net = cp;
 471                                 while (*cp && *cp != ';' &&
 472                                         isascii(*cp) &&
 473                                         !isspace((unsigned char)*cp))
 474                                     cp++;
 475                                 n = *cp;
 476                                 *cp = 0;
 477                                 if (inet_aton(net, &a)) {
 478                                     statp->sort_list[nsort].mask = a.s_addr;
 479                                 } else {
 480                                     statp->sort_list[nsort].mask =
 481                                         net_mask(statp->sort_list[nsort].addr);
 482                                 }
 483                             } else {
 484                                 statp->sort_list[nsort].mask =
 485                                     net_mask(statp->sort_list[nsort].addr);
 486                             }
 487                             nsort++;
 488                         }
 489                         *cp = n;
 490                     }
 491                     continue;
 492                 }
 493 #endif
 494                 if (MATCH(buf, "options")) {
 495                     res_setoptions(statp, buf + sizeof("options") - 1, "conf");
 496                     continue;
 497                 }
 498             }
 499             if (nserv > 0)
 500                 statp->nscount = nserv;
 501 #ifdef RESOLVSORT
 502             statp->nsort = nsort;
 503 #endif
 504             statp->_u._ext.ext->resfd = dup(fileno(fp));
 505             (void) fclose(fp);
 506             if (fstat(statp->_u._ext.ext->resfd, &st) != -1)
 507                     __res_conf_time = statp->_u._ext.ext->res_conf_time =
 508                         st.st_mtimespec;
 509 #ifndef __minix
 510             statp->_u._ext.ext->kq = kqueue1(O_CLOEXEC);
 511             EV_SET(&kc, statp->_u._ext.ext->resfd, EVFILT_VNODE,
 512                 EV_ADD|EV_ENABLE|EV_CLEAR, NOTE_DELETE|NOTE_WRITE| NOTE_EXTEND|
 513                 NOTE_ATTRIB|NOTE_LINK|NOTE_RENAME|NOTE_REVOKE, 0, 0);
 514             (void)kevent(statp->_u._ext.ext->kq, &kc, 1, NULL, 0, &ts);
 515 #else /* __minix */
 516         statp->_u._ext.ext->kq = -1;
 517 #endif /* !__minix */
 518         } else {
 519             statp->_u._ext.ext->kq = -1;
 520             statp->_u._ext.ext->resfd = -1;
 521         }
 522 /*
 523  * Last chance to get a nameserver.  This should not normally
 524  * be necessary
 525  */
 526 #ifdef NO_RESOLV_CONF
 527         if(nserv == 0)
 528                 nserv = get_nameservers(statp);
 529 #endif
 530
 531         if (statp->defdname[0] == 0 &&
 532             gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
 533             (cp = strchr(buf, '.')) != NULL)
 534                 strcpy(statp->defdname, cp + 1);
 535
 536         /* find components of local domain that might be searched */
 537         if (havesearch == 0) {
 538                 pp = statp->dnsrch;
 539                 *pp++ = statp->defdname;
 540                 *pp = NULL;
 541
 542                 dots = 0;
 543                 for (cp = statp->defdname; *cp; cp++)
 544                         dots += (*cp == '.');
 545
 546                 cp = statp->defdname;
 547                 while (pp < statp->dnsrch + MAXDFLSRCH) {
 548                         if (dots < LOCALDOMAINPARTS)
 549                                 break;
 550                         cp = strchr(cp, '.') + 1;    /*%< we know there is one */
 551                         *pp++ = cp;
 552                         dots--;
 553                 }
 554                 *pp = NULL;
 555 #ifdef DEBUG
 556                 if (statp->options & RES_DEBUG) {
 557                         printf(";; res_init()... default dnsrch list:\n");
 558                         for (pp = statp->dnsrch; *pp; pp++)
 559                                 printf(";;\t%s\n", *pp);
 560                         printf(";;\t..END..\n");
 561                 }
 562 #endif
 563         }
 564
 565         if ((cp = getenv("RES_OPTIONS")) != NULL)
 566                 res_setoptions(statp, cp, "env");
 567         statp->options |= RES_INIT;
 568         return (statp->res_h_errno);
 569 }
 570
 571 int
 572 res_check(res_state statp, struct timespec *mtime)
 573 {
 574 #ifdef __minix
 575         /*
 576          * XXX: No update on change.
 577          */
 578         return 0;
 579 #else /* !__minix */
 580         /*
 581          * If the times are equal, then we check if there
 582          * was a kevent related to resolv.conf and reload.
 583          * If the times are not equal, then we don't bother
 584          * to check the kevent, because another thread already
 585          * did, loaded and changed the time.
 586          */
 587         if (timespeccmp(&statp->_u._ext.ext->res_conf_time,
 588             &__res_conf_time, ==)) {
 589                 struct kevent ke;
 590                 if (statp->_u._ext.ext->kq == -1)
 591                         goto out;
 592
 593                 switch (kevent(statp->_u._ext.ext->kq, NULL, 0, &ke, 1, &ts)) {
 594                 case 0:
 595                 case -1:
 596 out:
 597                         if (mtime)
 598                                 *mtime = __res_conf_time;
 599                         return 0;
 600                 default:
 601                         break;
 602                 }
 603         }
 604         (void)__res_vinit(statp, 0);
 605         if (mtime)
 606                 *mtime = __res_conf_time;
 607         return 1;
 608 #endif /* !__minix */
 609 }
 610
 611 static void
 612 res_setoptions(res_state statp, const char *options, const char *source)
 613 {
 614         const char *cp = options;
 615         int i;
 616         size_t j;
 617         struct __res_state_ext *ext = statp->_u._ext.ext;
 618
 619 #ifdef DEBUG
 620         if (statp->options & RES_DEBUG)
 621                 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
 622                        options, source);
 623 #endif
 624         while (*cp) {
 625                 /* skip leading and inner runs of spaces */
 626                 while (*cp == ' ' || *cp == '\t')
 627                         cp++;
 628                 /* search for and process individual options */
 629                 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
 630                         i = atoi(cp + sizeof("ndots:") - 1);
 631                         if (i <= RES_MAXNDOTS)
 632                                 statp->ndots = i;
 633                         else
 634                                 statp->ndots = RES_MAXNDOTS;
 635 #ifdef DEBUG
 636                         if (statp->options & RES_DEBUG)
 637                                 printf(";;\tndots=%d\n", statp->ndots);
 638 #endif
 639                 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
 640                         i = atoi(cp + sizeof("timeout:") - 1);
 641                         if (i <= RES_MAXRETRANS)
 642                                 statp->retrans = i;
 643                         else
 644                                 statp->retrans = RES_MAXRETRANS;
 645 #ifdef DEBUG
 646                         if (statp->options & RES_DEBUG)
 647                                 printf(";;\ttimeout=%d\n", statp->retrans);
 648 #endif
 649 #ifdef  SOLARIS2
 650                 } else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
 651                         /*
 652                          * For backward compatibility, 'retrans' is
 653                          * supported as an alias for 'timeout', though
 654                          * without an imposed maximum.
 655                          */
 656                         statp->retrans = atoi(cp + sizeof("retrans:") - 1);
 657                 } else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
 658                         /*
 659                          * For backward compatibility, 'retry' is
 660                          * supported as an alias for 'attempts', though
 661                          * without an imposed maximum.
 662                          */
 663                         statp->retry = atoi(cp + sizeof("retry:") - 1);
 664 #endif  /* SOLARIS2 */
 665                 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
 666                         i = atoi(cp + sizeof("attempts:") - 1);
 667                         if (i <= RES_MAXRETRY)
 668                                 statp->retry = i;
 669                         else
 670                                 statp->retry = RES_MAXRETRY;
 671 #ifdef DEBUG
 672                         if (statp->options & RES_DEBUG)
 673                                 printf(";;\tattempts=%d\n", statp->retry);
 674 #endif
 675                 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
 676 #ifdef DEBUG
 677                         if (!(statp->options & RES_DEBUG)) {
 678                                 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
 679                                        options, source);
 680                                 statp->options |= RES_DEBUG;
 681                         }
 682                         printf(";;\tdebug\n");
 683 #endif
 684                 } else if (!strncmp(cp, "no_tld_query",
 685                                     sizeof("no_tld_query") - 1) ||
 686                            !strncmp(cp, "no-tld-query",
 687                                     sizeof("no-tld-query") - 1)) {
 688                         statp->options |= RES_NOTLDQUERY;
 689                 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
 690                         statp->options |= RES_USE_INET6;
 691                 } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
 692                         statp->options |= RES_ROTATE;
 693                 } else if (!strncmp(cp, "no-check-names",
 694                                     sizeof("no-check-names") - 1)) {
 695                         statp->options |= RES_NOCHECKNAME;
 696                 } else if (!strncmp(cp, "check-names",
 697                                     sizeof("check-names") - 1)) {
 698                         statp->options &= ~RES_NOCHECKNAME;
 699                 }
 700 #ifdef RES_USE_EDNS0
 701                 else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
 702                         statp->options |= RES_USE_EDNS0;
 703                 }
 704 #endif
 705                 else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
 706                         statp->options |= RES_USE_DNAME;
 707                 }
 708                 else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
 709                         if (ext == NULL)
 710                                 goto skip;
 711                         cp += sizeof("nibble:") - 1;
 712                         j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
 713                         strncpy(ext->nsuffix, cp, j);
 714                         ext->nsuffix[j] = '\0';
 715                 }
 716                 else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
 717                         if (ext == NULL)
 718                                 goto skip;
 719                         cp += sizeof("nibble2:") - 1;
 720                         j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
 721                         strncpy(ext->nsuffix2, cp, j);
 722                         ext->nsuffix2[j] = '\0';
 723                 }
 724                 else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
 725                         cp += sizeof("v6revmode:") - 1;
 726                         /* "nibble" and "bitstring" used to be valid */
 727                         if (!strncmp(cp, "single", sizeof("single") - 1)) {
 728                                 statp->options |= RES_NO_NIBBLE2;
 729                         } else if (!strncmp(cp, "both", sizeof("both") - 1)) {
 730                                 statp->options &=
 731                                          ~RES_NO_NIBBLE2;
 732                         }
 733                 }
 734                 else {
 735                         /* XXX - print a warning here? */
 736                 }
 737    skip:
 738                 /* skip to next run of spaces */
 739                 while (*cp && *cp != ' ' && *cp != '\t')
 740                         cp++;
 741         }
 742 }
 743
 744 #ifdef RESOLVSORT
 745 /* XXX - should really support CIDR which means explicit masks always. */
 746 static uint32_t
 747 net_mask(struct in_addr in) /*!< XXX - should really use system's version of this  */
 748 {
 749         register uint32_t i = ntohl(in.s_addr);
 750
 751         if (IN_CLASSA(i))
 752                 return (htonl(IN_CLASSA_NET));
 753         else if (IN_CLASSB(i))
 754                 return (htonl(IN_CLASSB_NET));
 755         return (htonl(IN_CLASSC_NET));
 756 }
 757 #endif
 758
 759 static u_char srnd[16];
 760
 761 void
 762 res_rndinit(res_state statp)
 763 {
 764         struct timeval now;
 765         uint32_t u32;
 766         uint16_t u16;
 767         u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
 768
 769         gettimeofday(&now, NULL);
 770         u32 = (uint32_t)now.tv_sec;
 771         memcpy(rnd, &u32, 4);
 772         u32 = now.tv_usec;
 773         memcpy(rnd + 4, &u32, 4);
 774         u32 += (uint32_t)now.tv_sec;
 775         memcpy(rnd + 8, &u32, 4);
 776         u16 = getpid();
 777         memcpy(rnd + 12, &u16, 2);
 778 }
 779
 780 u_int
 781 res_nrandomid(res_state statp)
 782 {
 783         struct timeval now;
 784         uint16_t u16;
 785         MD5_CTX ctx;
 786         u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
 787
 788         gettimeofday(&now, NULL);
 789         u16 = (uint16_t) (now.tv_sec ^ now.tv_usec);
 790         memcpy(rnd + 14, &u16, 2);
 791 #ifndef HAVE_MD5
 792         MD5_Init(&ctx);
 793         MD5_Update(&ctx, rnd, 16);
 794         MD5_Final(rnd, &ctx);
 795 #else
 796         MD5Init(&ctx);
 797         MD5Update(&ctx, rnd, 16);
 798         MD5Final(rnd, &ctx);
 799 #endif
 800         memcpy(&u16, rnd + 14, 2);
 801         return ((u_int) u16);
 802 }
 803
 804 /*%
 805  * This routine is for closing the socket if a virtual circuit is used and
 806  * the program wants to close it.  This provides support for endhostent()
 807  * which expects to close the socket.
 808  *
 809  * This routine is not expected to be user visible.
 810  */
 811 void
 812 res_nclose(res_state statp)
 813 {
 814         int ns;
 815
 816         if (statp->_vcsock >= 0) {
 817                 (void) close(statp->_vcsock);
 818                 statp->_vcsock = -1;
 819                 statp->_flags &= ~(RES_F_VC | RES_F_CONN);
 820         }
 821         for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
 822                 if (statp->_u._ext.nssocks[ns] != -1) {
 823                         (void) close(statp->_u._ext.nssocks[ns]);
 824                         statp->_u._ext.nssocks[ns] = -1;
 825                 }
 826         }
 827 }
 828
 829 void
 830 res_ndestroy(res_state statp)
 831 {
 832         res_nclose(statp);
 833         if (statp->_u._ext.ext != NULL) {
 834                 if (statp->_u._ext.ext->kq != -1)
 835                         (void)close(statp->_u._ext.ext->kq);
 836                 if (statp->_u._ext.ext->resfd != -1)
 837                         (void)close(statp->_u._ext.ext->resfd);
 838                 free(statp->_u._ext.ext);
 839                 statp->_u._ext.ext = NULL;
 840         }
 841         if (statp->_rnd != NULL) {
 842                 free(statp->_rnd);
 843                 statp->_rnd = NULL;
 844         }
 845         statp->options &= ~RES_INIT;
 846 }
 847
 848 const char *
 849 res_get_nibblesuffix(res_state statp)
 850 {
 851         if (statp->_u._ext.ext)
 852                 return (statp->_u._ext.ext->nsuffix);
 853         return ("ip6.arpa");
 854 }
 855
 856 const char *
 857 res_get_nibblesuffix2(res_state statp)
 858 {
 859         if (statp->_u._ext.ext)
 860                 return (statp->_u._ext.ext->nsuffix2);
 861         return ("ip6.int");
 862 }
 863
 864 void
 865 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt)
 866 {
 867         int i, nserv;
 868         size_t size;
 869
 870         /* close open servers */
 871         res_nclose(statp);
 872
 873         /* cause rtt times to be forgotten */
 874         statp->_u._ext.nscount = 0;
 875
 876         nserv = 0;
 877         for (i = 0; i < cnt && nserv < MAXNS; i++) {
 878                 switch (set->sin.sin_family) {
 879                 case AF_INET:
 880                         size = sizeof(set->sin);
 881                         if (statp->_u._ext.ext)
 882                                 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
 883                                         &set->sin, size);
 884                         if (size <= sizeof(statp->nsaddr_list[nserv]))
 885                                 memcpy(&statp->nsaddr_list[nserv],
 886                                         &set->sin, size);
 887                         else
 888                                 statp->nsaddr_list[nserv].sin_family = 0;
 889                         nserv++;
 890                         break;
 891
 892 #ifdef HAS_INET6_STRUCTS
 893                 case AF_INET6:
 894                         size = sizeof(set->sin6);
 895                         if (statp->_u._ext.ext)
 896                                 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
 897                                         &set->sin6, size);
 898                         if (size <= sizeof(statp->nsaddr_list[nserv]))
 899                                 memcpy(&statp->nsaddr_list[nserv],
 900                                         &set->sin6, size);
 901                         else
 902                                 statp->nsaddr_list[nserv].sin_family = 0;
 903                         nserv++;
 904                         break;
 905 #endif
 906
 907                 default:
 908                         break;
 909                 }
 910                 set++;
 911         }
 912         statp->nscount = nserv;
 913
 914 }
 915
 916 int
 917 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt)
 918 {
 919         int i;
 920         size_t size;
 921         uint16_t family;
 922
 923         for (i = 0; i < statp->nscount && i < cnt; i++) {
 924                 if (statp->_u._ext.ext)
 925                         family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
 926                 else
 927                         family = statp->nsaddr_list[i].sin_family;
 928
 929                 switch (family) {
 930                 case AF_INET:
 931                         size = sizeof(set->sin);
 932                         if (statp->_u._ext.ext)
 933                                 memcpy(&set->sin,
 934                                        &statp->_u._ext.ext->nsaddrs[i],
 935                                        size);
 936                         else
 937                                 memcpy(&set->sin, &statp->nsaddr_list[i],
 938                                        size);
 939                         break;
 940
 941 #ifdef HAS_INET6_STRUCTS
 942                 case AF_INET6:
 943                         size = sizeof(set->sin6);
 944                         if (statp->_u._ext.ext)
 945                                 memcpy(&set->sin6,
 946                                        &statp->_u._ext.ext->nsaddrs[i],
 947                                        size);
 948                         else
 949                                 memcpy(&set->sin6, &statp->nsaddr_list[i],
 950                                        size);
 951                         break;
 952 #endif
 953
 954                 default:
 955                         set->sin.sin_family = 0;
 956                         break;
 957                 }
 958                 set++;
 959         }
 960         return (statp->nscount);
 961 }
 962
 963 /*! \file */