#!/usr/bin/perl -w

# Authors :
# GRNET Real Time Services Team
# 2004: Dimitrios Vardalis (original implementation using simph323) (email: dvardali@ccf.auth.gr)
# 2005-2006: Giorgos Kissandrakis (switched to ohphone use)
# 2006: Dimitrios Vardalis (minor improvements)

#use strict;
use Getopt::Std;
use FileHandle;
use IPC::Open2;
use vars qw($opt_p $opt_g $opt_u $opt_t $opt_h %ERRORS);
use vars qw($listenport $username $gatekeeper $timeout $output $attempts $pid);

$ERRORS{'OK'}      = 0;
$ERRORS{'WARNING'} = 1;
$ERRORS{'CRITICAL'}= 2;
$ERRORS{'UNKNOWN'} = 3;

use lib '/usr/local/libexec/nagios/' ;


my $PROGNAME = 'check_voip' ;
my $lastline;

sub print_help ();
sub print_usage ();
sub help ();
sub version ();
sub kill_process ();

$SIG{"ALRM"} = sub {
  close(Reader);
  if (defined(Writer)) {
    print Writer "X\n";
  }
  close(Writer);
  waitpid($pid, 0);
  $lastline =~ s/\n//g;
  print "VOIP UNKNOWN - Timed out trying to call after $attempts attempts and $timeout sec. ".
        " Last line: $lastline\n";
  exit $ERRORS{'UNKNOWN'};
};

unless(getopts('g:u:n:t:h:p:')) {
  print_usage();
  exit $ERRORS{'UNKNOWN'};
}

if ($opt_h){
  print_usage();
  exit $ERRORS{'OK'};
}

$timeout = 45;

if ($opt_p) {
	$listenport = $opt_p;
}
else {
	$listenport = 1720;
}

if ($opt_u) {
  $username = $opt_u;
}
else {
	print_usage();
	exit $ERRORS{'UNKNOWN'};	
}

if ($opt_g) {
  $gatekeeper = $opt_g;
}
else {
	print_usage();
	exit $ERRORS{'UNKNOWN'};	
}

if ($opt_t) { $timeout = $opt_t; }
my $test_prog = '/usr/local/bin/ohphone';
my $test_args = " --gatekeeper $gatekeeper --user $username --listenport $listenport -l";

my $test_cmd = $test_prog.$test_args;
###print "$test_cmd\n";
my $debug_file = "/var/tmp/check_voip.log";

unless (open DEBUG, ">> $debug_file ")  {
  print "VOIP WARNING - Couldn't open debug file [$debug_file] for append\n";
  exit $ERRORS{"WARNING"};
}

alarm($timeout);

while (1) {
  $attempts++;
  my $status = try_check();
  if (!$status) { 
   # print "Sleeping\n";
   sleep 3;
  }
}


sub try_check {
  $pid = open2(*Reader,*Writer,$test_cmd);
  Writer->autoflush();
  $output = '';

  while (<Reader>) {
    $output .= $_;
    $lastline = $_ ;
    if ($_ =~ /Gatekeeper set: (.*)/) { 
      print "VOIP OK - Successfully registered with gatekeeper $1.\n";
      close DEBUG;
      close(Reader);
      print Writer "X\n";
      close(Writer);
      waitpid ($pid, 0);
      exit $ERRORS{"OK"};
    }
    if ($_ =~ /(.*Could not open H.323 listener port.*)/ ) {
      close(Reader);
      print Writer "X\n";
      close(Writer);
      waitpid ($pid, 0);
      return 0;
    }
    if ($_ =~ /(.*Error registering with gatekeeper.*)/) { 
      print "VOIP CRITICAL - Unable to register with gatekeeper at IP $gatekeeper.\n";
      close DEBUG;
      close(Reader);
      print Writer "X\n";
      close(Writer);
      waitpid ($pid, 0);
      exit $ERRORS{"CRITICAL"};
    }
  }
  print "VOIP UNKNOWN - Unable to handle ohphone output.\n";
  close DEBUG;
  close(Reader);
  print Writer "X\n";
  close(Writer);
  waitpid ($pid, 0);
  exit $ERRORS{"UNKNOWN"};
}

sub print_usage () {
   print "Usage: $PROGNAME -g <Gatekeeper> -u ".
         "<Username> -t <timeout> -p <listenport>\n";
}

sub print_help () {
        print_usage();
        print '
-g, Gatekeeper to register to
-u, Username
-t, Timeout

';
}

sub help () {
  print_help();
  exit $ERRORS{'OK'};
}