#!/usr/bin/perl -w
# a tool for parsing ISC DHCP server logs.
# outline: 
# read entries into a tree, grouped by 
#   MAC address, 
#   IP address,
#   DHCP protocol message type ( 'RELEASE' 'REQUEST' 'OFFER' 'ACK' ...)
# ...and print this out

use strict;
use CGI qw/:standard -no_xhtml/;
use Data::Dumper;
$|=1;


my $MYNAME="current dhcpd log for " . `hostname`;
my $makufa;
#my $logfile="/var/log/messages";
my $logfile="/var/log/dhcpd/current";

open MESS, $logfile or die "can't open logfile $logfile";
while (<MESS>) {
	next unless /DHCP(\w+).* (\d+\.\d+\.\d+\.\d+) .* (..:..:..:..:..:..)/;
	my($dhcptype,$ip,$mac) = ($1,$2,$3); 
	$makufa->{$mac}->{$ip}->{$dhcptype}++;
};
close MESS;
#warn "did not print anything yet";
my @arp=`/sbin/arp`;

for my $mac ( keys %{$makufa} ) {
	for my $line ( @arp ) {
		if ( $line =~ /$mac/i ) {
			$makufa->{$mac}->{'arp'} = $line;
			last;
		}
	}
}

my $count = scalar keys %{$makufa};

print header,
 start_html($MYNAME),
 p("First line:\n" , `head -n 1 $logfile | /usr/local/bin/tai64nlocal`),
 h4("Total of $count MAC addresses"),
 pre( Dumper($makufa) ),
 end_html;

warn "$MYNAME has been executed\n";
1;