NetBSD/lib/libc/net/res_init.c

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1993-03-21 12:45:37 +03:00
/*-
* Copyright (c) 1985, 1989 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)res_init.c 6.15 (Berkeley) 2/24/91";*/
static char *rcsid = "$Id: res_init.c,v 1.3 1993/08/26 00:46:17 jtc Exp $";
1993-03-21 12:45:37 +03:00
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*
* Resolver state default settings
*/
struct state _res = {
RES_TIMEOUT, /* retransmition time interval */
4, /* number of times to retransmit */
RES_DEFAULT, /* options flags */
1, /* number of name servers */
};
/*
* Set up default settings. If the configuration file exist, the values
* there will have precedence. Otherwise, the server address is set to
* INADDR_ANY and the default domain name comes from the gethostname().
*
* The configuration file should only be used if you want to redefine your
* domain or run without a server on your machine.
*
* Return 0 if completes successfully, -1 on error
*/
res_init()
{
register FILE *fp;
register char *cp, **pp;
register int n;
char buf[BUFSIZ];
int nserv = 0; /* number of nameserver records read from file */
int haveenv = 0;
int havesearch = 0;
_res.nsaddr.sin_addr.s_addr = INADDR_ANY;
_res.nsaddr.sin_family = AF_INET;
_res.nsaddr.sin_port = htons(NAMESERVER_PORT);
_res.nscount = 1;
/* Allow user to override the local domain definition */
if ((cp = getenv("LOCALDOMAIN")) != NULL) {
(void)strncpy(_res.defdname, cp, sizeof(_res.defdname));
haveenv++;
}
if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
/* read the config file */
while (fgets(buf, sizeof(buf), fp) != NULL) {
/* read default domain name */
if (!strncmp(buf, "domain", sizeof("domain") - 1)) {
if (haveenv) /* skip if have from environ */
continue;
cp = buf + sizeof("domain") - 1;
while (*cp == ' ' || *cp == '\t')
cp++;
if ((*cp == '\0') || (*cp == '\n'))
continue;
(void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
if ((cp = index(_res.defdname, '\n')) != NULL)
*cp = '\0';
havesearch = 0;
continue;
}
/* set search list */
if (!strncmp(buf, "search", sizeof("search") - 1)) {
if (haveenv) /* skip if have from environ */
continue;
cp = buf + sizeof("search") - 1;
while (*cp == ' ' || *cp == '\t')
cp++;
if ((*cp == '\0') || (*cp == '\n'))
continue;
(void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
if ((cp = index(_res.defdname, '\n')) != NULL)
*cp = '\0';
/*
* Set search list to be blank-separated strings
* on rest of line.
*/
cp = _res.defdname;
pp = _res.dnsrch;
*pp++ = cp;
for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
if (*cp == ' ' || *cp == '\t') {
*cp = 0;
n = 1;
} else if (n) {
*pp++ = cp;
n = 0;
}
}
/* null terminate last domain if there are excess */
while (*cp != '\0' && *cp != ' ' && *cp != '\t')
cp++;
*cp = '\0';
*pp++ = 0;
havesearch = 1;
continue;
}
/* read nameservers to query */
if (!strncmp(buf, "nameserver", sizeof("nameserver") - 1) &&
nserv < MAXNS) {
cp = buf + sizeof("nameserver") - 1;
while (*cp == ' ' || *cp == '\t')
cp++;
if ((*cp == '\0') || (*cp == '\n'))
continue;
if ((_res.nsaddr_list[nserv].sin_addr.s_addr =
inet_addr(cp)) == (unsigned)-1) {
_res.nsaddr_list[nserv].sin_addr.s_addr
= INADDR_ANY;
continue;
}
_res.nsaddr_list[nserv].sin_family = AF_INET;
_res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT);
nserv++;
continue;
}
}
if (nserv > 1)
_res.nscount = nserv;
(void) fclose(fp);
}
if (_res.defdname[0] == 0) {
if (gethostname(buf, sizeof(_res.defdname)) == 0 &&
(cp = index(buf, '.')))
(void)strcpy(_res.defdname, cp + 1);
}
/* find components of local domain that might be searched */
if (havesearch == 0) {
pp = _res.dnsrch;
*pp++ = _res.defdname;
for (cp = _res.defdname, n = 0; *cp; cp++)
if (*cp == '.')
n++;
cp = _res.defdname;
for (; n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH;
n--) {
cp = index(cp, '.');
*pp++ = ++cp;
}
*pp++ = 0;
}
_res.options |= RES_INIT;
return (0);
}