move resolver.h to /usr/include

[unix-history] / usr / src / lib / libc / net / res_init.c

/*
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)res_init.c  6.4 (Berkeley) %G%";
#endif LIBC_SCCS and not lint

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <arpa/nameser.h>
#include <resolv.h>

/*
* Resolver configuration file. Contains the address of the
* inital name server to query and the default domain for
* non fully qualified domain names.
*/

#ifdef CONFFILE
char    *conffile = CONFFILE;
#else
char    *conffile = "/etc/resolv.conf";
#endif

/*
* Resolver state default settings
*/

#ifndef RES_TIMEOUT
#define RES_TIMEOUT 10
#endif

struct state _res = {
   RES_TIMEOUT,                 /* retransmition time interval */
   4,                           /* number of times to retransmit */
   RES_RECURSE|RES_DEFNAMES,    /* 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;
   char buf[BUFSIZ], *cp;
   extern u_long inet_addr();
   extern char *index();
   extern char *strcpy(), *strncpy();
#ifdef DEBUG
   extern char *getenv();
#endif DEBUG
   int n = 0;    /* number of nameserver records read from file */

   _res.nsaddr.sin_addr.s_addr = INADDR_ANY;
   _res.nsaddr.sin_family = AF_INET;
   _res.nsaddr.sin_port = htons(NAMESERVER_PORT);
   _res.nscount = 1;
   _res.defdname[0] = '\0';

   if ((fp = fopen(conffile, "r")) != NULL) {
       /* read the config file */
       while (fgets(buf, sizeof(buf), fp) != NULL) {
           /* read default domain name */
           if (!strncmp(buf, "domain", sizeof("domain") - 1)) {
               cp = buf + sizeof("domain") - 1;
               while (*cp == ' ' || *cp == '\t')
                   cp++;
               if (*cp == '\0')
                   continue;
               (void)strncpy(_res.defdname, cp, sizeof(_res.defdname));
               _res.defdname[sizeof(_res.defdname) - 1] = '\0';
               if ((cp = index(_res.defdname, '\n')) != NULL)
                   *cp = '\0';
               continue;
           }
           /* read nameservers to query */
           if (!strncmp(buf, "nameserver", 
              sizeof("nameserver") - 1) && (n < MAXNS)) {
               cp = buf + sizeof("nameserver") - 1;
               while (*cp == ' ' || *cp == '\t')
                   cp++;
               if (*cp == '\0')
                   continue;
               _res.nsaddr_list[n].sin_addr.s_addr = inet_addr(cp);
               if (_res.nsaddr_list[n].sin_addr.s_addr == (unsigned)-1) 
                   _res.nsaddr_list[n].sin_addr.s_addr = INADDR_ANY;
               _res.nsaddr_list[n].sin_family = AF_INET;
               _res.nsaddr_list[n].sin_port = htons(NAMESERVER_PORT);
               if ( ++n >= MAXNS) { 
                   n = MAXNS;
#ifdef DEBUG
                   if ( _res.options & RES_DEBUG )
                       printf("MAXNS reached, reading resolv.conf\n");
#endif DEBUG
               }
               continue;
           }
       }
       if ( n > 1 ) 
           _res.nscount = n;
       (void) fclose(fp);
   }
   if (_res.defdname[0] == 0) {
       if (gethostname(buf, sizeof(_res.defdname)) == 0 &&
          (cp = index(buf, '.')))
            (void)strcpy(_res.defdname, cp + 1);
   }

#ifdef DEBUG
   /* Allow user to override the local domain definition */
   if ((cp = getenv("LOCALDOMAIN")) != NULL)
       (void)strncpy(_res.defdname, cp, sizeof(_res.defdname));
#endif DEBUG
   _res.options |= RES_INIT;
   return(0);
}