#!/usr/bin/perl
#
# Original shell script to convert a KA9Q NOS format gateways route file 
# (usually called 'encap.txt') into a Linux routing table format for the 
# IP tunnel driver. Enhanced Perl version by OH7LZB
#
# From: Ron Atkinson <n8fow[at]amgate.cc.wayne.edu>
#
#  This script is basically the 'munge' script written by Bdale N3EUA
#  for the IPIP daemon and is modified by Ron Atkinson N8FOW. It's
#  purpose is to convert a KA9Q NOS format gateways route file
#  (usually called 'encap.txt') into a Linux routing table format
#  for the IP tunnel driver.
#
# Enhanced Perl version by Heikki Hannikainen <hessu@pspt.fi>
#
# Version history:
#
#	2.1	hessu	Thu Jul  8 19:41:18 EEST 1999
#		- Modified for /sbin/ip
#
#        Usage: 
#               eg.  munge encap.txt rc.tun-routes
#
# NOTE: Before you use this script be sure to check or change the
#       following items:
#
#     1) Change the @my_addresses list to include your gateways
#        ip address(es) (and others which you have hand-made
#        static routes for). REMOVE MINE !!
#

# Tunnel device used
$tunnel_device = "tunl0";
# Local gateway addresses (whose routes are skipped)
@my_addresses = ("193.167.178.112", "193.166.55.160", "195.148.207.30");
# route binary
$routebin = "/sbin/ip";
# tcp window to set
$window = 840;

if ($#ARGV != 1) {
	print "Usage: $0 encap.txt rc.tun-routes\n";
	exit 1;
}

open(inf, @ARGV[0]) || die "Cannot open @ARGV[0]: $!";
open(upf, ">@ARGV[1]") or die "Cannot open @ARGV[1]: $!";;

$hdr = "#\n# IP tunnel route table\n#\n#\n";
print upf $hdr;

LOOP: while ($line = <inf>) {

	@fields = ();
	@abytes = ();
	$bits = "";
	
	@fields = split(' ', $line);
	if (@fields[0] ne "route") { next LOOP; }
	
	$gw = @fields[4];
	$net = @fields[2];
	($addr, $bits) = split('/', $net);
	if (!$bits) { $bits = 32; }
	@abytes = split('\.', $addr);
	
	for ($i = 0; $i < 4; $i++) {
		if (@abytes[$i] eq "") { @abytes[$i] = "0"; }
	}
	$addr = join('.', @abytes);
	
	foreach $my (@my_addresses) {
		if ($gw eq $my) {
			print "$addr/$bits > $gw blocked, local gw\n";
			next LOOP;
		}
	}
	
	if ($addr !~ /^44\./) {
		print "$addr/$bits > $gw blocked, non-amprnet address!\n";
		next LOOP;
	}
	
	if ($gw =~ /^44\./) {
		print "$addr/$bits > $gw blocked, inside amprnet!\n";
		next LOOP;
	}
	
	if ($bits < 16) {
		print "$addr/$bits > $gw  blocked, mask smaller than 16 bits!\n";
		next LOOP;
	}
	
	print upf "$routebin route add $addr/$bits via $gw dev $tunnel_device onlink 2>/dev/null\n";
}

print upf "#\n# the end\n#\n";

close(inf);
close(upf);