/*
  Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
  2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free
  Software Foundation, Inc.

  This file is part of GNU Inetutils.

  GNU Inetutils is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or (at
  your option) any later version.

  GNU Inetutils is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see `http://www.gnu.org/licenses/'. */

/*
 * Copyright (c) 1983, 1993
 *	The 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. 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.
 */

#include <config.h>

#include <string.h>

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

/*
 * Look for an invitation on 'machine'
 */
static int
look_for_invite (CTL_RESPONSE *rp)
{
  current_state = "Checking for invitation on caller's machine";
  ctl_transact (his_machine_addr, 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);
    }
}

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

  /* the rest of msg was set up in get_names */
  msg.ctl_addr.sa_family = htons (ctl_addr.sin_family);
  memcpy (msg.ctl_addr.sa_data,
	  ((struct sockaddr *) &ctl_addr)->sa_data,
	  sizeof ((struct sockaddr *) & ctl_addr)->sa_data);

  /* 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
    {
      struct sockaddr addr;

      if (rp->addr.sa_family != AF_INET)
	p_error ("Response uses invalid network address");
      errno = 0;
      addr.sa_family = rp->addr.sa_family;
#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
      addr.sa_len = sizeof (struct sockaddr_in);
#endif
      memcpy (&addr.sa_data, &rp->addr.sa_data, sizeof (addr.sa_data));

      if (connect (sockt, &addr, sizeof (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_machine_addr, msg, DELETE, rp);
      close (sockt);
      open_sockt ();
      return (0);
    }
  p_error ("Unable to connect with initiator");

  return -1;
}
