BSD 4_3_Net_2 release

[unix-history] / usr / src / kerberosIV / krb / get_krbhst.c

/*
* $Source: /usr/src/kerberosIV/krb/RCS/get_krbhst.c,v $
* $Author: kfall $
*
* Copyright 1985, 1986, 1987, 1988 by the Massachusetts Institute
* of Technology.
*
* For copying and distribution information, please see the file
* <mit-copyright.h>.
*/

#ifndef lint
static char *rcsid_get_krbhst_c =
"$Header: /usr/src/kerberosIV/krb/RCS/get_krbhst.c,v 4.9 90/06/25 20:55:54 kfall Exp $";
#endif /* lint */

#include <mit-copyright.h>
#include <stdio.h>
#include <des.h>
#include <krb.h>
#include <strings.h>

/*
* Given a Kerberos realm, find a host on which the Kerberos authenti-
* cation server can be found.
*
* krb_get_krbhst takes a pointer to be filled in, a pointer to the name
* of the realm for which a server is desired, and an integer, n, and
* returns (in h) the nth entry from the configuration file (KRB_CONF,
* defined in "krb.h") associated with the specified realm.
*
* On end-of-file, krb_get_krbhst returns KFAILURE.  If n=1 and the
* configuration file does not exist, krb_get_krbhst will return KRB_HOST
* (also defined in "krb.h").  If all goes well, the routine returnes
* KSUCCESS.
*
* The KRB_CONF file contains the name of the local realm in the first
* line (not used by this routine), followed by lines indicating realm/host
* entries.  The words "admin server" following the hostname indicate that 
* the host provides an administrative database server.
*
* For example:
*
*      ATHENA.MIT.EDU
*      ATHENA.MIT.EDU kerberos-1.mit.edu admin server
*      ATHENA.MIT.EDU kerberos-2.mit.edu
*      LCS.MIT.EDU kerberos.lcs.mit.edu admin server
*
* This is a temporary hack to allow us to find the nearest system running
* kerberos.  In the long run, this functionality will be provided by a
* nameserver.
*/

krb_get_krbhst(h,r,n)
   char *h;
   char *r;
   int n;
{
   FILE *cnffile;
   char tr[REALM_SZ];
   char linebuf[BUFSIZ];
   register int i;

   if ((cnffile = fopen(KRB_CONF,"r")) == NULL) {
       if (n==1) {
           (void) strcpy(h,KRB_HOST);
           return(KSUCCESS);
       }
       else
           return(KFAILURE);
   }
   if (fscanf(cnffile,"%s",tr) == EOF)
       return(KFAILURE);
   /* run through the file, looking for the nth server for this realm */
   for (i = 1; i <= n;) {
       if (fgets(linebuf, BUFSIZ, cnffile) == NULL) {
           (void) fclose(cnffile);
           return(KFAILURE);
       }
       if (sscanf(linebuf, "%s %s", tr, h) != 2)
           continue;
       if (!strcmp(tr,r))
           i++;
   }
   (void) fclose(cnffile);
   return(KSUCCESS);
}