#!/usr/bin/perl -w
# ping a range of hosts preiodically and record average ping times
# to in csv format to files named pinglog-yyyymmdd.csv
#
# also has capability of executing commands on host goind down / coming up
#
#
#
#
# Copyright (C) 2008  Glen Pitt-Pladdy
#
# 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
#
#


# names and hosts (or ips) to monitor
# ensure they are coma seperated
%MONITOR = (
	'Localhost' => 'localhost',
	'LocalIP' => '127.0.0.1'
);

# do some action when the host goes up / down
# ensure they are coma seperated
%HOST_UP = (
	'LocalIP' => '/bin/echo up |/usr/bin/mutt -e "set record=" -s "LocalIP UP" "root@localhost"'
);
%HOST_DOWN = (
	'LocalIP' => '/bin/echo down |/usr/bin/mutt -e "set record=" -s "LocalIP DOWN" "root@localhost"'
);

# delay between ping cycles
$DELAY = 30;
# timeout waiting for return packet
$TIMEOUT = 1;
# number of missed pings to consider as down
$COUNT = 2;
# wait between pings
$INTERVAL = 0.5;



# ping program (not using per Net::Ping as this requires root - ping is suid)
$PING = "/bin/ping -n -W $TIMEOUT -c $COUNT -i $INTERVAL";






# main loop
$startday = 0;
$targettime = $^T;
while ( 1 ) {
	$sampletime = time;
	( $sec,$min,$hour,$mday,$mon,$year ) = localtime ( $sampletime );
	++$mon;
	$year += 1900;
	$nextline = sprintf ( "%04d/%02d/%02d %02d:%02d:%02d", $year, $mon, $mday,
							$hour, $min, $sec );
	# check if we need a new file
	if ( $startday != $mday ) {
		$startday = $mday;
		if ( fileno ( LOG ) ) { close LOG; }
		$file = sprintf ( "pinglog-%04d%02d%02d.csv", $year, $mon, $mday );
		open LOG, ">>$file" or die "FATAL: can't write file \"$file\": $!\n";
		# heading
		print LOG "time";
		foreach $host (keys %MONITOR) {
			print LOG ",$host";
		}
		print LOG "\n";
	}
	# run monitoring cycle
	foreach $name (keys %MONITOR) {
		$host = $MONITOR{$name};
		open PNG, "$PING $host |" or die "FATAL: can't start $PING: $!\n";
		$last = "NULL";
		while ( defined ( $line = <PNG> ) ) { $last = $line; }
		close PNG;
		chomp $last;
		# match line
		if ( $last =~ /^rtt min\/avg\/max\/mdev = [0-9\.]+\/([0-9\.]+)\/[0-9\.]+\/[0-9\.]+ ms$/ ) {
			# good return - store data
			$nextline .= ",$1";
			# check if we are doing any action
			if ( defined ($laststatus{$name})
					and $laststatus{$name} eq 'down' ) {
				# host came up - execute HOST_UP
				if ( $HOST_UP{$name} ) { system $HOST_UP{$name}; }
			}
			$laststatus{$name} = 'up';
		} else {
			# bad return - log null
			$nextline .= ",NULL";
			# check if we are doing any action
			if ( defined ($laststatus{$name})
					and $laststatus{$name} eq 'up' ) {
				# host went down - execute HOST_DOWN
				if ( $HOST_DOWN{$name} ) { system $HOST_DOWN{$name}; }
			}
			$laststatus{$name} = 'down';
		}
	}
	print LOG "$nextline\n";
	# work out next timing
	$targettime += $DELAY;
	$delay = $targettime - time;
	if ( $delay > 0 ) { sleep $delay; }
		else { print STDERR "WARNING: required delay $delay seconds\n"; }
}