#!/usr/bin/perl
#
# ishadm - Information Super Highway Administration. Unix/Linux.
#
# This checks and enables network routes to the Information Super Highway
#  to ensure maximum Internet performance. Must be run as root to update
#  the routes.
#
# 07-Nov-2004	ver 1.00
#
# USAGE: ishadm [-de]
#	ishadm		# check current config
#	ishadm -e	# enable Information Super Highway
#	ishadm -d	# disable Information Super Highway
#
# WARNING: Wear a seatbelt and obey local traffic laws.
#
# COPYRIGHT: Copyright (c) 2004 Brendan Gregg.
#
#  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.
#
#  (http://www.gnu.org/copyleft/gpl.html)
#
# 07-Nov-2004	Brendan Gregg	Created this.

$hosts = "/etc/hosts";
@Table = `netstat -r`;
$ENV{PATH} = "/usr/sbin:/usr/bin:/bin";


#
#  Check Status
#
unless (@ARGV) {
	$ok = 0;
	foreach (@Table) {
		$ok = 1 if /information-super-highway/;
	}
	if ($ok) {
		print "Information-Super-Highway is ON.\n"; 
	} else {
		print "Information-Super-Highway is OFF.\n";
	}
	exit(0);
} 

#
#  Admin
#
unless (-o "/etc/hosts" || $ARGV[0] !~ /^-[ed]$/) {
	print "ERROR2: Only root can drive the Information-Super-Highway.\n";
	exit(1);
}
open(HOSTS,"$hosts") || die "ERROR3: Can't read $hosts: $!\n";
@Hosts = <HOSTS>;
close HOSTS;

if ($ARGV[0] eq "-e") {
	### Enable 
	if (grep(/information-super-highway/,@Hosts) == 0) {
		open(HOSTS,">>$hosts") || die "ERROR4: writing $hosts: $!\n";
		print HOSTS "127.0.0.42	information-super-highway\n";
		close HOSTS;
	}
	if (grep(/information-super-highway/,@Table) == 0) {
		system("route add information-super-highway 127.0.0.1");
		print "Information-Super-Highway is now ON.\n"; 
	} else {
		print "Information-Super-Highway was already ON.\n"; 
	}
} elsif ($ARGV[0] eq "-d") {
	### Disable 
	if (grep(/information-super-highway/,@Table) == 1) {
		system("route delete information-super-highway 127.0.0.1");
		print "Information-Super-Highway is now OFF.\n"; 
	} else {
		print "Information-Super-Highway was already OFF.\n"; 
	}
	if (grep(/information-super-highway/,@Hosts) == 1) {
		open(HOSTS,">$hosts") || die "ERROR4: writing $hosts: $!\n";
		foreach $line (@Hosts) {
			print HOSTS $line 
			 unless $line =~ /information-super-highway/;
		}
		close HOSTS;
	}
} else {
	### Usage
	print STDERR "USAGE: ishadm [-de]\n";
	print STDERR "   eg,\n";
	print STDERR "      ishadm     # check status\n";
	print STDERR "      ishadm -e  # enable\n";
	print STDERR "      ishadm -d  # disable\n";
}