346 lines
10 KiB
C
346 lines
10 KiB
C
/*-
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* Copyright (c) 1985, 1989 Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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/*static char *sccsid = "from: @(#)res_init.c 6.15 (Berkeley) 2/24/91";*/
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static char *rcsid = "$Id: res_init.c,v 1.6 1994/10/15 07:59:01 deraadt Exp $";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.h>
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#include <resolv.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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static void res_setoptions __P((char *, char *));
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static u_int32_t net_mask __P((struct in_addr));
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/*
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* Resolver state default settings
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*/
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struct __res_state _res = {
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RES_TIMEOUT, /* retransmition time interval */
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4, /* number of times to retransmit */
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RES_DEFAULT, /* options flags */
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1, /* number of name servers */
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};
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/*
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* Set up default settings. If the configuration file exist, the values
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* there will have precedence. Otherwise, the server address is set to
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* INADDR_ANY and the default domain name comes from the gethostname().
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*
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* The configuration file should only be used if you want to redefine your
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* domain or run without a server on your machine.
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*
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* Return 0 if completes successfully, -1 on error
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*/
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res_init()
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{
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register FILE *fp;
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register char *cp, **pp, *net;
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register int n;
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char buf[BUFSIZ], buf2[BUFSIZ];
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int nserv = 0; /* number of nameserver records read from file */
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int haveenv = 0;
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int havesearch = 0;
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int nsort = 0;
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u_long mask;
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_res.nsaddr.sin_addr.s_addr = INADDR_ANY;
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_res.nsaddr.sin_family = AF_INET;
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_res.nsaddr.sin_port = htons(NAMESERVER_PORT);
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_res.nscount = 1;
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_res.ndots = 1;
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_res.pfcode = 0;
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strncpy(_res.lookups, "f", sizeof _res.lookups);
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/* Allow user to override the local domain definition */
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if ((cp = getenv("LOCALDOMAIN")) != NULL) {
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(void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
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haveenv++;
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/*
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* Set search list to be blank-separated strings
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* from rest of env value. Permits users of LOCALDOMAIN
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* to still have a search list, and anyone to set the
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* one that they want to use as an individual (even more
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* important now that the rfc1535 stuff restricts searches)
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*/
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cp = _res.defdname;
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pp = _res.dnsrch;
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*pp++ = cp;
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for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
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if (*cp == '\n') /* silly backwards compat */
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break;
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else if (*cp == ' ' || *cp == '\t') {
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*cp = 0;
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n = 1;
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} else if (n) {
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*pp++ = cp;
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n = 0;
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havesearch = 1;
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}
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}
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/* null terminate last domain if there are excess */
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while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
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cp++;
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*cp = '\0';
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*pp++ = 0;
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}
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if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
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strncpy(_res.lookups, "bf", sizeof _res.lookups);
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/* read the config file */
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while (fgets(buf, sizeof(buf), fp) != NULL) {
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/* skip comments */
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if ((*buf == ';') || (*buf == '#'))
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continue;
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/* read default domain name */
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if (!strncmp(buf, "domain", sizeof("domain") - 1)) {
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if (haveenv) /* skip if have from environ */
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continue;
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cp = buf + sizeof("domain") - 1;
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while (*cp == ' ' || *cp == '\t')
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cp++;
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if ((*cp == '\0') || (*cp == '\n'))
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continue;
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(void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
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if ((cp = strpbrk(_res.defdname, "\t\n")) != NULL)
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*cp = '\0';
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havesearch = 0;
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continue;
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}
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/* lookup types */
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if (!strncmp(buf, "lookup", sizeof("lookup") -1)) {
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char *sp = NULL;
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bzero(_res.lookups, sizeof _res.lookups);
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cp = buf + sizeof("lookup") - 1;
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for (n = 0;; cp++) {
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if (n == MAXDNSLUS)
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break;
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if ((*cp == '\0') || (*cp == '\n')) {
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if (sp) {
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if (*sp=='y' || *sp=='b' || *sp=='f')
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_res.lookups[n++] = *sp;
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sp = NULL;
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}
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break;
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} else if ((*cp == ' ') || (*cp == '\t') || (*cp == ',')) {
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if (sp) {
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if (*sp=='y' || *sp=='b' || *sp=='f')
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_res.lookups[n++] = *sp;
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sp = NULL;
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}
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} else if (sp == NULL)
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sp = cp;
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}
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continue;
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}
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/* set search list */
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if (!strncmp(buf, "search", sizeof("search") - 1)) {
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if (haveenv) /* skip if have from environ */
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continue;
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cp = buf + sizeof("search") - 1;
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while (*cp == ' ' || *cp == '\t')
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cp++;
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if ((*cp == '\0') || (*cp == '\n'))
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continue;
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(void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
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if ((cp = strchr(_res.defdname, '\n')) != NULL)
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*cp = '\0';
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/*
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* Set search list to be blank-separated strings
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* on rest of line.
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*/
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cp = _res.defdname;
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pp = _res.dnsrch;
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*pp++ = cp;
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for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
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if (*cp == ' ' || *cp == '\t') {
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*cp = 0;
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n = 1;
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} else if (n) {
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*pp++ = cp;
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n = 0;
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}
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}
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/* null terminate last domain if there are excess */
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while (*cp != '\0' && *cp != ' ' && *cp != '\t')
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cp++;
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*cp = '\0';
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*pp++ = 0;
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havesearch = 1;
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continue;
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}
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/* read nameservers to query */
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if (!strncmp(buf, "nameserver", sizeof("nameserver") - 1) &&
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nserv < MAXNS) {
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struct in_addr a;
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cp = buf + sizeof("nameserver") - 1;
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while (*cp == ' ' || *cp == '\t')
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cp++;
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if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
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_res.nsaddr_list[nserv].sin_addr = a;
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_res.nsaddr_list[nserv].sin_family = AF_INET;
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_res.nsaddr_list[nserv].sin_port =
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htons(NAMESERVER_PORT);
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nserv++;
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}
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continue;
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}
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if (!strncmp(buf, "sortlist", sizeof("sortlist") - 1)) {
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struct in_addr a;
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cp = buf + sizeof("sortlist") - 1;
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while (*cp == ' ' || *cp == '\t')
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cp++;
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while (sscanf(cp,"%[0-9./]s", buf2) && nsort < MAXRESOLVSORT) {
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if (net = strchr(buf2, '/'))
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*net = '\0';
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if (inet_aton(buf2, &a)) {
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_res.sort_list[nsort].addr = a;
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if (net && inet_aton(net+1, &a)) {
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_res.sort_list[nsort].mask = a.s_addr;
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} else {
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_res.sort_list[nsort].mask =
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net_mask(_res.sort_list[nsort].addr);
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}
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nsort++;
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}
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if (net)
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*net = '/';
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cp += strlen(buf2);
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while (*cp == ' ' || *cp == '\t')
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cp++;
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}
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continue;
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}
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if (!strncmp(buf, "options", sizeof("options") -1)) {
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res_setoptions(buf + sizeof("options") - 1, "conf");
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continue;
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}
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}
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if (nserv > 1)
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_res.nscount = nserv;
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_res.nsort = nsort;
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(void) fclose(fp);
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}
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if (_res.defdname[0] == 0) {
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if (gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
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(cp = strchr(buf, '.')))
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(void)strcpy(_res.defdname, cp + 1);
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}
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/* find components of local domain that might be searched */
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if (havesearch == 0) {
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pp = _res.dnsrch;
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*pp++ = _res.defdname;
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*pp = NULL;
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}
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if ((cp = getenv("RES_OPTIONS")) != NULL)
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res_setoptions(cp, "env");
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_res.options |= RES_INIT;
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return (0);
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}
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static void
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res_setoptions(options, source)
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char *options, *source;
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{
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char *cp = options;
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int i;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG) {
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printf(";; res_setoptions(\"%s\", \"%s\")...\n",
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options, source);
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}
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#endif
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while (*cp) {
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/* skip leading and inner runs of spaces */
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while (*cp == ' ' || *cp == '\t')
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cp++;
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/* search for and process individual options */
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if (!strncmp(cp, "ndots:", sizeof("ndots:")-1)) {
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i = atoi(cp + sizeof("ndots:") - 1);
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if (i <= RES_MAXNDOTS)
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_res.ndots = i;
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else
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_res.ndots = RES_MAXNDOTS;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG) {
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printf(";;\tndots=%d\n", _res.ndots);
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}
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#endif
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} else if (!strncmp(cp, "debug", sizeof("debug")-1)) {
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#ifdef DEBUG
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if (!(_res.options & RES_DEBUG)) {
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printf(";; res_setoptions(\"%s\", \"%s\")..\n",
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options, source);
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_res.options |= RES_DEBUG;
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}
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printf(";;\tdebug\n");
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#endif
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} else {
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/* XXX - print a warning here? */
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}
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/* skip to next run of spaces */
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while (*cp && *cp != ' ' && *cp != '\t')
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cp++;
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}
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}
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static u_int32_t
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net_mask(in) /* XXX - should really use system's version of this */
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struct in_addr in;
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{
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register u_int32_t i = ntohl(in.s_addr);
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if (IN_CLASSA(i))
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return (htonl(IN_CLASSA_NET));
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if (IN_CLASSB(i))
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return (htonl(IN_CLASSB_NET));
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return (htonl(IN_CLASSC_NET));
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}
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