1 /* 2 * Copyright (c) 1985 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 */ 6 7 #ifndef lint 8 static char sccsid[] = "@(#)res_init.c 5.4 (Berkeley) 07/31/85"; 9 #endif not lint 10 11 #include <sys/types.h> 12 #include <sys/socket.h> 13 #include <netinet/in.h> 14 #include <stdio.h> 15 #include <arpa/nameser.h> 16 #include <arpa/resolv.h> 17 18 /* 19 * Resolver configuration file. Contains the address of the 20 * inital name server to query and the default domain for 21 * non fully qualified domain names. 22 */ 23 24 #ifdef CONFFILE 25 char *conffile = CONFFILE; 26 #else 27 char *conffile = "/usr/local/lib/resolv.conf"; 28 #endif 29 30 /* 31 * Resolver state default settings 32 */ 33 struct state _res = { 34 90, 35 2, 36 RES_RECURSE|RES_DEFNAMES, 37 }; 38 39 /* 40 * Read the configuration file for default settings. 41 * Return true if the name server address is initialized. 42 */ 43 res_init() 44 { 45 FILE *fp; 46 char buf[BUFSIZ], *cp; 47 int n; 48 extern u_long inet_addr(); 49 extern char *index(), *getenv(); 50 51 _res.options |= RES_INIT; 52 _res.nsaddr.sin_family = AF_INET; 53 _res.nsaddr.sin_addr.s_addr = INADDR_ANY; 54 _res.nsaddr.sin_port = htons(NAMESERVER_PORT); 55 56 /* first try reading the config file */ 57 if ((fp = fopen(conffile, "r")) != NULL) { 58 if (fgets(_res.defdname, sizeof(_res.defdname), fp) == NULL) 59 _res.defdname[0] = '\0'; 60 else if ((cp = index(_res.defdname, '\n')) != NULL) 61 *cp = '\0'; 62 if (fgets(buf, sizeof (buf), fp) != NULL) 63 _res.nsaddr.sin_addr.s_addr = inet_addr(buf); 64 (void) fclose(fp); 65 } 66 67 /* Allow user to override the local domain definition */ 68 if ((cp = getenv("LOCALDOMAIN")) != NULL) 69 strncpy(_res.defdname, cp, sizeof(_res.defdname)); 70 } 71