#!/usr/bin/perl -Tw
#####################################################
#
# Copyright (C) 2001, Jon Hart <jhart@ccs.neu.edu>
# 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
#################################
#
# A makeshift config file generator for dhcpd.
# Reads a file containing MAC's and creates valid
# host sections for a dhcpd.conf file, and then combines
# this with a base config file.  The result is a complete
# config file for dhcpd.
#
# Jon Hart (jhart@ccs.neu.edu)
#   or
# (warchild@spoofed.org)
# April 26th, 2001
######################################################
use strict;
$ENV{'PATH'} = "/usr/bin:/bin";
# holds the PID of dhcpd 
my $DHCPD_PID =  "`cat /var/run/dhcpd.pid`";
# how dhcpd is started.
my $DHCPD_PATH = "/usr/sbin/dhcpd";
my $DHCPD_CMD = "$DHCPD_PATH -q -cf /var/adm/dhcpd.conf de0";
# where the dhcpd config will live.
# we will write to this later.
my $DHCP_CONFIG = "/var/adm/dhcpd.conf";
# a base config file that'll be merged with the leases
# to ultimately form the final config file.
# we won't write to this, only read from it.
my $DHCP_CONFIG_BASE = "/var/adm/dhcpd.conf.base";
# flat text file to hold name/email/MAC pairs.
# just a flat text file to be edited by hand.
my $DHCP_CONFIG_LEASES = "/var/adm/dhcp.leases";
# how many hosts get added to the config file
my $hostnum;
# the final file we will write to.
open(FINAL, "> $DHCP_CONFIG");
	open(BASE, "$DHCP_CONFIG_BASE");
	while(<BASE>) { print FINAL; }
	close(BASE);
	# create host entries for the registered MAC's
	open(LEASES, "$DHCP_CONFIG_LEASES");
	while (<LEASES>) {
		my $record = $_;
		if ( /^#/ ) { next; }
		chomp;	
		$hostnum++;
		# rather than generate hostnames by hand,
		# simply count how man registered MAC's we've
		# had and hack together a name.
		# The name will look like "CCSWireless1"
		my $hostname = "CCSWireless".$hostnum;
		my ($mac, $email, $name) = split(/,/, $record);
		print FINAL "host $hostname { hardware ethernet $mac; }\n";
	}
	print "Wrote $hostnum hosts to the config file.\n";
close(LEASES);
close(FINAL);
# big deal, we wrote a config file.
# Now let dhcpd know whats up.
if ( -f "/var/run/dhcpd.pid" ) { 
	my $try = system("kill -9 $DHCPD_PID");
	if ( $try != 0 ) { print "Could not kill dhcpd:  $?\n"; }
	elsif ( $try == 0 ) { print "Killed dhcpd.\n"; } 
}
if ( -x "$DHCPD_PATH" ) {
	my $try = system("$DHCPD_CMD");
	if ( $try !=0 ) { print "Could not start dhcpd:  $?\n"; }
	elsif ($try == 0 ) { print "Started dhcpd.\n"; }
}