xref: /csrg-svn/lib/libc/net/res_init.c (revision 24081)
118548Sralph /*
221386Sdist  * Copyright (c) 1985 Regents of the University of California.
321386Sdist  * All rights reserved.  The Berkeley software License Agreement
421386Sdist  * specifies the terms and conditions for redistribution.
518548Sralph  */
618548Sralph 
721386Sdist #ifndef lint
8*24081Skjd static char sccsid[] = "@(#)res_init.c	5.3 (Berkeley) 07/29/85";
921386Sdist #endif not lint
1021386Sdist 
1118142Sralph #include <sys/types.h>
1218142Sralph #include <sys/socket.h>
1318142Sralph #include <netinet/in.h>
1418142Sralph #include <stdio.h>
15*24081Skjd #include <arpa/nameser.h>
16*24081Skjd #include <arpa/resolv.h>
1718142Sralph 
1818142Sralph /*
1918142Sralph  * Resolver state default settings
2018142Sralph  */
2118142Sralph struct state _res = {
2218142Sralph 	90,
2318142Sralph 	2,
2418142Sralph 	RES_RECURSE|RES_DEFNAMES,
2518142Sralph };
2618142Sralph 
2718142Sralph /*
2818142Sralph  * Read the configuration file for default settings.
2918142Sralph  * Return true if the name server address is initialized.
3018142Sralph  */
3118142Sralph res_init()
3218142Sralph {
3318142Sralph 	FILE *fp;
3418142Sralph 	char buf[BUFSIZ], *cp;
3518142Sralph 	int n;
3618142Sralph 	extern u_long inet_addr();
3718527Sralph 	extern char *index(), *getenv();
3818142Sralph 
3918142Sralph 	_res.options |= RES_INIT;
4018142Sralph 	_res.nsaddr.sin_family = AF_INET;
4118142Sralph 	_res.nsaddr.sin_addr.s_addr = INADDR_ANY;
4223871Skjd 	_res.nsaddr.sin_port = htons(NAMESERVER_PORT);
4318142Sralph 
4418142Sralph 	/* first try reading the config file */
4518142Sralph 	if ((fp = fopen(CONFFILE, "r")) != NULL) {
4618527Sralph 		if (fgets(_res.defdname, sizeof(_res.defdname), fp) == NULL)
4718142Sralph 			_res.defdname[0] = '\0';
4818142Sralph 		else if ((cp = index(_res.defdname, '\n')) != NULL)
4918142Sralph 			*cp = '\0';
5018527Sralph 		if (fgets(buf, sizeof (buf), fp) != NULL)
5118142Sralph 			_res.nsaddr.sin_addr.s_addr = inet_addr(buf);
5218142Sralph 		(void) fclose(fp);
5318142Sralph 	}
5418142Sralph 
5518527Sralph 	/* Allow user to override the local domain definition */
5618527Sralph 	if ((cp = getenv("LOCALDOMAIN")) != NULL)
5718527Sralph 		strncpy(_res.defdname, cp, sizeof(_res.defdname));
5818142Sralph }
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