Logo Search packages:      
Sourcecode: netkit-ntalk version File versions  Download package

look_up.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the University of
 *    California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * From: @(#)look_up.c  5.7 (Berkeley) 3/1/91
 */
char lu_rcsid[] = 
  "$Id: look_up.c,v 1.6 1998/11/27 10:55:58 dholland Exp $";

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <errno.h>
#include "talk.h"

static int look_for_invite(CTL_RESPONSE *rp);

/*
 * See if the local daemon has an invitation for us.
 */
int
check_local(void)
{
      CTL_RESPONSE response;
      register CTL_RESPONSE *rp = &response;

      /* must be initiating a talk */
      if (!look_for_invite(rp))
            return 0;
      /*
       * There was an invitation waiting for us, 
       * so connect with the other (hopefully waiting) party 
       */
      current_state = "Waiting to connect with caller";
      do {
            if (rp->addr.ta_family != AF_INET)
                  p_error("Response uses invalid network address");
            errno = 0;
            if (connect(sockt,
                (struct sockaddr *)&rp->addr, sizeof (rp->addr)) != -1)
                  return 1;
      } while (errno == EINTR);
      if (errno == ECONNREFUSED) {
            /*
             * The caller gave up, but his invitation somehow
             * was not cleared. Clear it and initiate an 
             * invitation. (We know there are no newer invitations,
             * the talkd works LIFO.)
             */
            ctl_transact(HIS_DAEMON, msg, DELETE, rp);
            close(sockt);
            open_sockt();
            return 0;
      }
      p_error("Unable to connect with initiator");
      /*NOTREACHED*/
      return 0;
}

/*
 * Look for an invitation on 'machine'
 */
static int
look_for_invite(CTL_RESPONSE *rp)
{
/*    struct in_addr machine_addr; */

      current_state = "Checking for invitation on caller's machine";
      ctl_transact(HIS_DAEMON, msg, LOOK_UP, rp);
      /* the switch is for later options, such as multiple invitations */
      switch (rp->answer) {

      case SUCCESS:
            msg.id_num = htonl(rp->id_num);
            return (1);

      default:
            /* there wasn't an invitation waiting for us */
            return (0);
      }
}

Generated by  Doxygen 1.6.0   Back to index