#!/usr/bin/perl

###	
###	CHECKPORT.PL
###	(c) 2003 Software Poetry, Inc.
###	http://www.softwarepoetry.com/webob
###
###	Verify that a server is alive by opening a port and, for some protocols,
###	looking for a success string. Note the USE statements below for
###	required modules ... use "perl -MCPAN '-e install Net::POP3'" or similar
###	if any are missing.
###
###	Usage: perl checkport.pl host timeout protocol [port]
###	       host = name or ip of server 
###		   timeout = timeout in seconds 
###		   protocol = tcp/ftp/pop3/smtp (tcp == just open a socket) 
###		   port = port number (optional if protocol is not tcp)
###
###	License: This software is provided as-is with NO WARRANTY WHATSOEVER.
###	Software Poetry makes no claims as to its fitness for any purpose.
###	This file and any derivatives or translations of it may be freely
###	copied and redistributed so long as the original license and copyright
###	notices are included and not altered.
###

use strict;
use IO::Socket::INET;
use Net::FTP;
use Net::POP3;
use Net::SMTP;

# +-------------------------------------------------------------------------
# | Entrypoint
# +-------------------------------------------------------------------------

if (($#ARGV < 2) || (($#ARGV < 3) && @ARGV[0] eq 'tcp'))
	{
	print "Usage: checkport.pl host timeout protocol [port]\n";
	print "       host = name or ip of server\n";
	print "       timeout = timeout in seconds\n";
	print "       protocol = tcp/ftp/pop3/smtp (tcp == just open a socket)\n";
	print "       port = port number (optional if protocol is not tcp\n";
	exit(1);
	}

my $szHost = @ARGV[0];
my $csecTimeout = @ARGV[1];
my $szProto = @ARGV[2];
my $nPort;
my $fConnectedOK;

if ($#ARGV >= 3)
	{ $nPort = @ARGV[3]; }
else
	{ $nPort = 0; }

$fConnectedOK = 0;

if ($szProto eq 'tcp')
	{
	my $sock = IO::Socket::INET->new(PeerAddr => $szHost,
									 PeerPort => $nPort,
									 Timeout => $csecTimeout);

	if ($sock)
		{
		$fConnectedOK = 1;
		$sock->shutdown(2);
		}

	}
elsif ($szProto eq 'ftp')
	{
	my $ftp = Net::FTP->new($szHost, 
							Timeout => $csecTimeout,
							Port => (($nPort == 0) ? 21 : $nPort));

	if ($ftp)
		{
		$fConnectedOK = 1;
		$ftp->quit;
		}
	}
elsif ($szProto eq 'pop3')
	{
	my $pop3 = Net::POP3->new($szHost,
							  Timeout => $csecTimeout,
							  Port => (($nPort == 0) ? 110 : $nPort));

	if ($pop3)
		{
		$fConnectedOK = 1;
		$pop3->quit;
		}
	}
elsif ($szProto eq 'smtp')
	{
	my $smtp = Net::SMTP->new($szHost,
							  Timeout => $csecTimeout,
							  Port => (($nPort == 0) ? 25 : $nPort));

	if ($smtp)
		{
		$fConnectedOK = 1;
		$smtp->quit;
		}
	}
else
	{
	print "unknown protocol $szProto\n";
	exit(2);
	}

if (!$fConnectedOK)
	{
	print "connect failed\n";
	exit(3);
	}

print "connected ok\n";
exit(0);