#!/usr/local/bin/perl
# (C) H.Ichikawa,2002/03/12
# alive.pl (check if service is alive)
# version 0.03 (2002/03/15)
#
use IO::Socket;
use IO::Select;

########### user code ############
sub comment
{
	my $msg=shift @_;
	# we assume $msg is not tainted!
        system("perl ./ircnotice.pl \"$msg\"");
#	print "$msg\n";
}

############ don't change after this ##########

if($#ARGV<2){
	print "usage: perl alive.pl ALWAYS|ERR server service\n";
	exit();
}

$mode=$ARGV[0];
$server=$ARGV[1];
$service=$ARGV[2];

undef $port;
$convert{"imap"}=143;
$convert{"pop"}=110;
$convert{"smtp"}=25;
$port=$convert{$service};

unless(defined $port){
	comment("invalid argument: $server:$service");
	print "INVALID ARGUMENT\n";
	exit();
}

#main
$sock= IO::Socket::INET->new(PeerAddr => $server,
	PeerPort => $port,
	Proto    => 'tcp',
	Timeout  => 3);

unless(defined $sock){
	comment("$server:$service is down? (cannot connect)");
	print "REFUSED\n";
	undef $sock;
	exit();
}

$myselect = IO::Select->new();
$myselect->add($sock);

sleep(5);

unless( $myselect->can_read(3) ){
	comment("$server:$service is down? (response timeout)");
	print "NORES\n";
	$sock->close();
	undef $sock;
	exit();
}

$sock->recv($data,100);

$check="ERR";
if($service eq "imap"){ $check="OK" if($data =~ m/^\*\ OK/ ) };
if($service eq "pop"){ $check="OK" if($data =~ m/^\+OK\ / ) };
if($service eq "smtp"){ $check="OK" if($data =~ m/^220\ / ) };

$bye="";
$bye="a logout\r\n" if($service eq "imap");
$bye="quit\r\n" if($service eq "pop");
$bye="quit\r\n" if($service eq "smtp");

$sock->send($bye);
$sock->close();
undef $sock;

if($check eq "OK"){
	comment("$server:$service is OK") if($mode =~ /^always$/i);
	print "OK\n"
}else{
	comment("$server:$service is down? (error message)");
	print "ERR\n"
}
exit();

#EOF