/*  MasqMail
    Copyright (C) 2001 Oliver Kurth

    This program 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 2 of the License, or
    (at your option) any later version.

    This program 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, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#include <glib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
#include <time.h>

#include "masqmail.h"
#include "dotlock.h"

gboolean dot_lock(gchar *lock_name, gchar *hitch_name)
{
  gboolean ok = FALSE;
  int fd;

  fd = open(hitch_name, O_WRONLY | O_CREAT | O_EXCL, 0);
  if(fd != -1){
    struct stat stat_buf;

    close(fd);
    link(hitch_name, lock_name);
    if(stat(hitch_name, &stat_buf) == 0){
      if(stat_buf.st_nlink == 2){
        unlink(hitch_name);
        ok = TRUE;
      }
      else{
        if(stat(lock_name, &stat_buf) == 0){
          if((time(NULL) - stat_buf.st_mtime) > MAX_LOCKAGE){
            /* remove lock if uncredibly old */
            unlink(lock_name);

            link(hitch_name, lock_name);
            if(stat(hitch_name, &stat_buf) == 0){
              if(stat_buf.st_nlink == 2){
                unlink(hitch_name);
                ok = TRUE;
              }
            }
          }
        }
      }
    }
    if(!ok){
      unlink(hitch_name);
    }
  }else
    logwrite(LOG_WARNING, "could not create lock file %s: %s\n",
	     lock_name, strerror(errno));

  return ok;
}

gboolean dot_unlock(gchar *lock_name)
{
  unlink(lock_name);

  return TRUE;
}