#!/usr/bin/env perl
use warnings;
use strict;
#
# Author: 
#
# 2011(C)
#
# Change History
# 0.1					Initial Release
# 0.2 20150109.01				Added epoport.txt file to pass ePO port
#
# Description: Reads list of server names by their host names, checks to see if
# they are alive via ping, completes an nbtstat -a and returns any lines containing
# the host name and then checks to see if ePO port is open on the alive system.
#
# Input:
#	srvlst.txt containing one hostname per line
#	epoport.txt containing ePO port
#
# Output:
#	PingResults.csv
#		Format: Hostname, IP address, Alive status (Yes|No|Unknown Host|Unreachable|Unknown status), NBTSTAT result (NUL|$hostname), ePO port status (Open|closed)

my $epoport = '';
my $socket = "";
my $hostcnt = 0;

open (my $conf, '<epoport.txt') or die "Run aborted. Cannot open the ePO port file (epoport.txt)";
while(<$conf>) { 
   my $line = $_;
   chomp($line);
   ($epoport) = split(",", $line);
};
close ($conf);
print "ePO port: $epoport\n\n";

open (IN, "<srvlst.txt") or die "Run aborted. Cannot open endpoint list file (srvlst.txt)";
open (OUT, ">PingResults.csv") or die "Run aborted. Unable to open result file (PingResults.csv)";
print OUT "Hostname,IP,Alive,NBTHost,Port $epoport\n";

print "Start to check hosts\n";

while (<IN>) { 
	my $HOST = $_;
	chomp $HOST;
	print "Checking $HOST... ";
	my $IP = '';
	my $NBTHost = '';
	my $Alive = 'No';
	my $ePOPort = 'Closed';
	my $out = "";

	++$hostcnt;

	my $PingReply = `PING -n 1 -w 1 $HOST`;
	if ($PingReply =~ /unreachable/) {
		print "unreachable\n";
		$Alive = 'Unreachable';
	} elsif ($PingReply =~ /Reply from/) {
		$Alive = 'Yes';
		print "alive ";
		my @Temp = split / /, $PingReply;
		$IP = $Temp[2];
		$IP =~ s/\[//g;
		$IP =~ s/\]//g;
		my $NBTResults = `nbtstat -a $IP | find \"UNIQUE\"`;
		while (index($NBTResults,'  ') > -1) {
			$NBTResults =~ s/  / /g;
		}
		my @NBTResults = split /\n/, $NBTResults;
	
		# We only need the first returned hostname of the NBT results (they're usually duplicates)
		my @LineTemp = split / /, $NBTResults[0];
		$NBTHost = $LineTemp[1];
		if ($NBTHost eq $HOST) {
			$NBTHost = '';
			print "unique\n";
			# Check ePO open port
			my $epoResponse = CheckPort($HOST,$epoport);
			if ($epoResponse == 1) {
				$ePOPort = "Open";
			} else {
				$ePOPort = "Closed";
			};
 		} else {
			print "Not unique\n";
			$Alive = 'Unknown status';
		}
	} elsif ($PingReply =~ /could not find host/) {
		print "unknown\n";
		$Alive = 'Unknown host';
	} else {
		print "not alive\n";
		$Alive = 'No';
	}
	print OUT "$HOST,$IP,$Alive,$NBTHost,$ePOPort\n";
}
close OUT;
close IN;
print "\nCheck completed. Checked $hostcnt hosts\n";

sub CheckPort {
	use IO::Socket::INET;
	my ($host,$port) = @_;
	my $open = eval{ $socket = new IO::Socket::INET # opens a socket
	(
	PeerAddr => $host,
	PeerPort => $port,
	Proto => getprotobyname('tcp') || 6 # tcp socket or sopcket 6(for old comps)
	)};

	if ($open) { return 1; }
	else { return 0; }
}