#!/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. G0LGS' perl version (2007)
#
# Change path above to your location of Perl
# Usage: ./ipip.munge < encap.txt > ipip.routes
#
# Outside of this script you'll need to implement policy routing for 
# your local networks. I.e:
#/sbin/ip rule add from 44.8.0.160 table default
#/sbin/ip rule add from 44.0.0.160 to 44.0.0.8/ table main
#
# Ampr Gateway IPIP Tunnel Munge Script V1.1 for ipiproute2
# By Stewart Wilkinson (G0LGS)
# Checks the IP Subnet / Netmask are Valid

# Modified by Pontus Falk (sm0rux) <pfalk@ax25.org>

$Vers="V2.0-1 2007 Oct 02";

#$DEBUG=1;

# Usage: Gateway (encap) file on stdin, Linux route format file on stdout.
# ie: ipip_munge < encap.txt > linux-routes

# NOTE: The following should be checked/changed before using this script:
#
# 1) ${AMPR}    Set to your Local Ampr IP (for Tunnel device)
#
# 2) ${INTADDR} Set to your Internet IP Address
#               As defined in the Ampr Gateways Files.
#
# 3) ${LOCAL}   Your script to handle adding local tunnels (if any).
#
# 4) ${TUNL}    Set to correct device for your system.
#
# 5) ${IP_OP}   Additional Options for 'ip route add'
#    ${RO_OP}   or older 'route add' commands.
#               (ie mss / window settings)

# Your AMPR IP for the Tunnel Device
${AMPR}="44.8.0.160";

# Your Internet IP
${INTADDR}="70.137.68.217";

# Script to handle adding local tunnels (if any).
${LOCAL}="ipip_local";

# Tunnel Device
${TUNL}="tunl0";

# Extra Options for 'ip route add'
${IP_OP}="";

# Extra Options for old 'route add'
${RO_OP}="mss 512 window 1024";


#---------------------------------------------------------
# Nothing below should need Changing - Unless it's broken
#---------------------------------------------------------

# Check if we have 'iproute' or if we need to use 'route'
if( -x "/sbin/ip" ){
        ${iproute}=1;
        ${options} = "onlink " . ${IP_OP};

}elsif( -x "/sbin/route" ){
        ${iproute}=0;
        ${options} = ${RO_OP};

}else{
        print STDERR "ERROR:\tUnable to find 'iproute' package or 'route' command\n";
        print STDERR "\tCannot Continue - script aborted\n";
        exit 1;
}


printf "#\n# IPIP tunnel Routes - built by %s on %s", $ENV{LOGNAME}, `date`;
printf "# Created by ipip_munge %s (by G0LGS)\n#\n", $Vers;

printf "#\necho Stopping ${TUNL}\n";
printf "/sbin/ifconfig ${TUNL} down\n#\n";

printf "/bin/sleep 2\n#\n";

printf "#\necho -n 'Starting ${TUNL} '\n";
printf "/sbin/ifconfig ${TUNL} ${AMPR} txqueuelen 1000 up\n";
printf "/sbin/ip route del 44.0.0.0/8\n";

printf "#\n";

$lines=0;
while( $src = <STDIN> ){

        chomp($src);

        # Ignore any non-route lines
        if( $src !~ /^route addprivate/ ){
                next;
        }

        # Split line
        ($f1,$f2,$f3,$f4,$f5) = split( / /, $src, 5 );

        # Ignore our own entries
        if( ${f5} =~ /^${INTADDR}$/ ){
                next;
        }

        # IP Subnet / Netmask
        ($s1, $s2) = split( '\/', $f3 );
        ($n1, $n2, $n3, $n4) = split( '\.', $s1 );

        # Work around lines with Subnets:44.....
        if( $n1 =~ /subnets\:(\d*)/i ){
                $n1 = $1;
        }

        if (! defined($n1) ||  $n1 =~ /^$/ ){ $n1 ="0"; }
        if (! defined($n2) ||  $n2 =~ /^$/){ $n2 ="0"; }
        if (! defined($n3) ||  $n3 =~ /^$/){ $n3 ="0"; }
        if (! defined($n4) ||  $n4 =~ /^$/){ $n4 ="0"; }

        if (! defined($s2) ||  $s2 =~ /^$/){ $s2 ="32"; }

        if( &CheckNetMask() == 1 ){

                # Good IP / NM
                if( ${iproute} ){
                        if( $s2 == "32" ){
                                printf "echo %s\n", ${f5} if $DEBUG;
                                printf "/sbin/ip route add %s.%s.%s.%s via %s dev %s %s\n", $n1, $n2, $n3, $n4, $f5, ${TUNL}, ${options};
                        }else{
                                printf "echo %s\n", ${f5} if $DEBUG;
                                printf "/sbin/ip route add %s.%s.%s.%s/%s via %s dev %s %s\n", $n1, $n2, $n3, $n4, $s2, $f5, ${TUNL}, ${options};
                        }
                }else{
                        if( $s2 == "32" ){
                                printf "echo %s\n", ${f5} if $DEBUG;
                                printf "/sbin/route add -host %s.%s.%s.%s gw %s dev %s %s\n", $n1, $n2, $n3, $n4, $f5, ${TUNL}, ${options};
                        }else{
                                printf "echo %s\n", ${f5} if $DEBUG;
                                printf "/sbin/route add -net %s.%s.%s.%s/%s gw %s dev %s %s\n", $n1, $n2, $n3, $n4, $s2, $f5, ${TUNL}, ${options};
                        }
                }

        }else{
                # Broken IP / NM
                printf "# Invalid Netmask: ";
                if( ${iproute} ){
                        if( $s2 == "32" ){
                                printf "/sbin/ip route add %s.%s.%s.%s via %s dev %s %s\n", $n1, $n2, $n3, $n4, $f5, ${TUNL}, ${options};
                        }else{
                                printf "/sbin/ip route add %s.%s.%s.%s/%s via %s dev %s %s\n", $n1, $n2, $n3, $n4, $s2, $f5, ${TUNL}, ${options};
                        }
                }else{
                        if( $s2 == "32" ){
                                printf "/sbin/route add -host %s.%s.%s.%s gw %s dev %s %s\n", $n1, $n2, $n3, $n4, $f5, ${TUNL}, ${options};
                        }else{
                                printf "/sbin/route add -net %s.%s.%s.%s/%s gw %s dev %s %s\n", $n1, $n2, $n3, $n4, $s2, $f5, ${TUNL}, ${options};
                        }
                }
        }

        $lines++;
        if( ! ($lines % 25) ){
                printf "echo -n '.'\n";
        }

}

# Add Local Routes
if( -f ${LOCAL} ){
        if( open(LOCAL, "< ${LOCAL}" ) ) {
                while( $L = <LOCAL> ){
                        printf $L;
                }
                close(LOCAL);
        }
}else{
        printf "#\n#No Local Routes Found\n";
}

printf "#\n# default the rest of amprnet via mirrorshades.ucsd.edu\n#\n";

if( ${iproute} ) {
        printf "/sbin/ip route add 44.0.0.0/8 via 169.228.66.251 dev %s %s\n", ${TUNL}, ${options};
}else{
        printf "/sbin/route add -net 44.0.0.0/8 gw 169.228.66.251 dev %s %s\n", ${TUNL}, ${options};
}

printf "\necho -e '\\nDone'\n# The End\n#\n";
exit;

sub CheckNetMask
{
        my($ret) = 0;

        # Calculate Netmask
        $NM = 0xFFFFFFFF;
        if( $s2 < 32 ){
                $NM = $NM << (32 - $s2);
        }

        # Convert Address to Full 32 Bit Value
        $AD =( ( ( ( ($n1 << 8) + $n2) << 8) + $n3) << 8) +$n4;

        # Check the Mask
        if( ($AD & $NM) == $AD ){
                $ret = 1;
        }

        return $ret;
}