1 #ifndef lint 2 static char sccsid[] = "@(#)res_init.c 4.1 (Berkeley) 03/01/85"; 3 #endif 4 5 #include <sys/types.h> 6 #include <sys/socket.h> 7 #include <netinet/in.h> 8 #include <stdio.h> 9 #include <nameser.h> 10 #include <resolv.h> 11 12 /* 13 * Resolver state default settings 14 */ 15 struct state _res = { 16 90, 17 2, 18 RES_RECURSE|RES_DEFNAMES, 19 }; 20 21 /* 22 * Read the configuration file for default settings. 23 * Return true if the name server address is initialized. 24 */ 25 res_init() 26 { 27 FILE *fp; 28 char buf[BUFSIZ], *cp; 29 int n; 30 extern u_long inet_addr(); 31 extern char *index(); 32 33 _res.options |= RES_INIT; 34 _res.nsaddr.sin_family = AF_INET; 35 _res.nsaddr.sin_addr.s_addr = INADDR_ANY; 36 _res.nsaddr.sin_port = HTONS(53); /* well known port number */ 37 38 /* first try reading the config file */ 39 if ((fp = fopen(CONFFILE, "r")) != NULL) { 40 if (fgets(_res.defdname, MAXDNAME, fp) == NULL) 41 _res.defdname[0] = '\0'; 42 else if ((cp = index(_res.defdname, '\n')) != NULL) 43 *cp = '\0'; 44 if (fgets(buf, sizeof (buf), fp) != NULL) { 45 (void) fclose(fp); 46 _res.nsaddr.sin_addr.s_addr = inet_addr(buf); 47 return (1); 48 } 49 (void) fclose(fp); 50 } 51 52 /* next, try getting the address of this host */ 53 54 /* finally, try broadcast */ 55 56 return (0); 57 } 58