#
# Shorewall 5.2 -- /usr/share/shorewall/Shorewall/Tunnels.pm
#
#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#     (c) 2007-2016 - Tom Eastep (teastep@shorewall.net)
#
#       Complete documentation is available at https://shorewall.org
#
#       This program is part of Shorewall.
#
#	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, see <http://www.gnu.org/licenses/>.
#
#   This module handles the /etc/shorewall/tunnels file.
#
package Shorewall::Tunnels;
require Exporter;
use Shorewall::Config qw(:DEFAULT :internal);
use Shorewall::Zones;
use Shorewall::IPAddrs;
use Shorewall::Chains qw(:DEFAULT :internal);
use Shorewall::Rules;

use strict;

our @ISA = qw(Exporter);
our @EXPORT = qw( setup_tunnels );
our @EXPORT_OK = ( );
our $VERSION = '5.2_0';

#
# Here starts the tunnel stuff -- we really should get rid of this crap...
#
sub setup_tunnels() {

    our $fw = firewall_zone;

    sub setup_one_ipsec {
	my ($inchainref, $outchainref, $kind, $source, $dest, $gatewayzones) = @_;

	( $kind, my ( $qualifier , $remainder ) ) = split( /:/, $kind, 3 );

	my $noah = 1;

	fatal_error "Invalid IPSEC modifier ($qualifier:$remainder)" if defined $remainder;

	if ( defined $qualifier ) {
	    if ( $qualifier eq 'ah' ) {
		fatal_error ":ah not allowed with ipsecnat tunnels" if $kind eq 'ipsecnat';
		$noah = 0;
	    } else {
		fatal_error "Invalid IPSEC modifier ($qualifier)" if $qualifier ne 'noah';
	    }
	}

	my @options = have_capability( 'RAW_TABLE' ) ? state_imatch 'NEW,UNTRACKED' : state_imatch 'NEW';

	add_tunnel_rule $inchainref,  p => 50, @$source;
	add_tunnel_rule $outchainref, p => 50, @$dest;

	unless ( $noah ) {
	    add_tunnel_rule $inchainref,  p => 51, @$source;
	    add_tunnel_rule $outchainref, p => 51, @$dest;
	}

	if ( $kind eq 'ipsec' ) {
	    add_tunnel_rule $inchainref,  p => 'udp --dport 500', @$source, @options;
	    add_tunnel_rule $outchainref, p => 'udp --dport 500', @$dest,   @options;
	} else {
	    add_tunnel_rule $inchainref,  p => 'udp', @$source, multiport => '--dports 500,4500', @options;
	    add_tunnel_rule $outchainref, p => 'udp', @$dest,   multiport => '--dports 500,4500', @options;
	}

	unless ( $gatewayzones eq '-' ) {
	    for my $zone ( split_list $gatewayzones, 'zone' ) {
		my $type = zone_type( $zone );
		fatal_error "Invalid zone ($zone) for GATEWAY ZONE" if $type == FIREWALL || $type == BPORT;
		$inchainref  = ensure_rules_chain( ${zone}, ${fw} );
		$outchainref = ensure_rules_chain( ${fw}, ${zone} );

		unless ( have_ipsec ) {
		    add_tunnel_rule $inchainref,  p => 50, @$source;
		    add_tunnel_rule $outchainref, p => 50, @$dest;

		    unless ( $noah ) {
			add_tunnel_rule $inchainref,  p => 51, @$source;
			add_tunnel_rule $outchainref, p => 51, @$dest;
		    }
		}

		if ( $kind eq 'ipsec' ) {
		    add_tunnel_rule $inchainref,  p => 'udp --dport 500', @$source, @options;
		    add_tunnel_rule $outchainref, p => 'udp --dport 500', @$dest,   @options;
		} else {
		    add_tunnel_rule $inchainref,  p => 'udp', @$source, multiport => '--dports 500,4500', @options;
		    add_tunnel_rule $outchainref, p => 'udp', @$dest,   multiport => '--dports 500,4500', @options;
		}
	    }
	}
    }

    sub setup_one_other {
	my ($inchainref, $outchainref, $source, $dest , $protocol) = @_;

	add_tunnel_rule $inchainref ,  p => $protocol, @$source;
	add_tunnel_rule $outchainref , p => $protocol, @$dest;
    }

    sub setup_pptp_client {
	my ($inchainref, $outchainref, $kind, $source, $dest ) = @_;

	add_tunnel_rule $outchainref,  p => 47, @$dest;
	add_tunnel_rule $inchainref,   p => 47, @$source;
	add_tunnel_rule $outchainref,  p => 'tcp --dport 1723', @$dest;
    }

    sub setup_pptp_server {
	my ($inchainref, $outchainref, $kind, $source, $dest ) = @_;

	add_tunnel_rule $inchainref,  p => 47, @$source;
	add_tunnel_rule $outchainref, p => 47, @$dest;
	add_tunnel_rule $inchainref,  p => 'tcp --dport 1723', @$source
	}

    sub setup_one_tinc {
	my ( $inchainref, $outchainref, $kind, $source, $dest ) = @_;

	add_tunnel_rule $inchainref,  p => 'udp --dport 655', @$source;
	add_tunnel_rule $outchainref, p => 'udp --dport 655', @$dest;
	add_tunnel_rule $inchainref,  p => 'tcp --dport 655', @$source;
	add_tunnel_rule $outchainref, p => 'tcp --dport 655', @$dest;
    }

    sub setup_one_openvpn {
	my ($inchainref, $outchainref, $kind, $source, $dest) = @_;

	my $protocol = 'udp';
	my $port     = 1194;

	( $kind, my ( $proto, $p, $remainder ) ) = split( /:/, $kind, 4 );

	fatal_error "Invalid port ($p:$remainder)" if defined $remainder;

	if ( supplied $p ) {
	    $port = $p;
	    $protocol = $proto;
	} elsif ( supplied $proto ) {
	    if ( "\L$proto" =~ /udp|tcp/ ) {
		$protocol = $proto;
	    } else {
		$port = $proto;
	    }
	}

	add_tunnel_rule $inchainref,  p => "$protocol --dport $port", @$source;
	add_tunnel_rule $outchainref, p => "$protocol --dport $port", @$dest;
    }

    sub setup_one_openvpn_client {
	my ($inchainref, $outchainref, $kind, $source, $dest) = @_;

	my $protocol = 'udp';
	my $port     = 1194;

	( $kind, my ( $proto, $p , $remainder ) ) = split( /:/, $kind, 4 );

	fatal_error "Invalid port ($p:$remainder)" if defined $remainder;

	if ( supplied $p ) {
	    $port = $p;
	    $protocol = $proto;
	} elsif ( supplied $proto ) {
	    if ( "\L$proto" =~ /udp|tcp/ ) {
		$protocol = $proto;
	    } else {
		$port = $proto;
	    }
	}

	add_tunnel_rule $inchainref,  p => "$protocol --sport $port", @$source;
	add_tunnel_rule $outchainref, p => "$protocol --dport $port", @$dest;
    }

    sub setup_one_openvpn_server {
	my ($inchainref, $outchainref, $kind, $source, $dest) = @_;

	my $protocol = 'udp';
	my $port     = 1194;

	( $kind, my ( $proto, $p , $remainder ) ) = split( /:/, $kind, 4 );

	fatal_error "Invalid port ($p:$remainder)" if defined $remainder;

	if ( supplied $p ) {
	    $port = $p;
	    $protocol = $proto;
	} elsif ( supplied $proto ) {
	    if ( "\L$proto" =~ /udp|tcp/ ) {
		$protocol = $proto;
	    } else {
		$port = $proto;
	    }
	}

	add_tunnel_rule $inchainref,  p => "$protocol --dport $port" , @$source;
	add_tunnel_rule $outchainref, p => "$protocol --sport $port",  @$dest;
    }

    sub setup_one_l2tp {
	my ($inchainref, $outchainref, $kind, $source, $dest) = @_;

	fatal_error "Unknown option ($1)" if $kind =~ /^.*?:(.*)$/;

	add_tunnel_rule $inchainref,  p => 'udp --sport 1701 --dport 1701', @$source;
	add_tunnel_rule $outchainref, p => 'udp --sport 1701 --dport 1701', @$dest;
    }

    sub setup_one_generic {
	my ($inchainref, $outchainref, $kind, $source, $dest) = @_;

	my $protocol = 'udp';
	my $port     = '--dport 5000';

	if ( $kind =~ /.*:.*:.*/ ) {
	    ( $kind, $protocol, $port) = split /:/, $kind;
	    $port = "--dport $port";
	} else {
	    $port = '';
	    ( $kind, $protocol ) = split /:/ , $kind if $kind =~ /.*:.*/;
	}

	add_tunnel_rule $inchainref,  p => "$protocol $port", @$source;
	add_tunnel_rule $outchainref, p => "$protocol $port", @$dest;
    }

    sub setup_one_tunnel($$$$) {
	my ( $kind , $zone, $gateways, $gatewayzones ) = @_;

	my $zonetype = zone_type( $zone );

	fatal_error "Invalid tunnel ZONE ($zone)" if $zonetype & ( FIREWALL | BPORT );

	my $inchainref  = ensure_rules_chain( ${zone}, ${fw}   );
	my $outchainref = ensure_rules_chain( ${fw},   ${zone} );

	$gateways = ALLIP if $gateways eq '-';

	my ( $net, $excl ) = handle_network_list( $gateways , 'src' );
	( $net, $excl )    = handle_network_list( $gateways , 'dst' );

	fatal_error "Exclusion is not allowed in the GATEWAYS column" if $excl;

	for my $gateway ( split_list $gateways, 'GATEWAYS' ) {
	    my @source = imatch_source_net $gateway;
	    my @dest   = imatch_dest_net   $gateway;

	    my %tunneltypes = ( 'ipsec'         => { function => \&setup_one_ipsec ,         params   => [ $kind, \@source, \@dest , $gatewayzones ] } ,
				'ipsecnat'      => { function => \&setup_one_ipsec ,         params   => [ $kind, \@source, \@dest , $gatewayzones ] } ,
				'ipip'          => { function => \&setup_one_other,          params   => [ \@source, \@dest , 4 ] } ,
				'gre'           => { function => \&setup_one_other,          params   => [ \@source, \@dest , 47 ] } ,
				'6to4'          => { function => \&setup_one_other,          params   => [ \@source, \@dest , 41 ] } ,
				'6in4'          => { function => \&setup_one_other,          params   => [ \@source, \@dest , 41 ] } ,
				'pptpclient'    => { function => \&setup_pptp_client,        params   => [ $kind, \@source, \@dest ] } ,
				'pptpserver'    => { function => \&setup_pptp_server,        params   => [ $kind, \@source, \@dest ] } ,
				'tinc'          => { function => \&setup_one_tinc,           params   => [ $kind, \@source, \@dest ] } ,
				'openvpn'       => { function => \&setup_one_openvpn,        params   => [ $kind, \@source, \@dest ] } ,
				'openvpnclient' => { function => \&setup_one_openvpn_client, params   => [ $kind, \@source, \@dest ] } ,
				'openvpnserver' => { function => \&setup_one_openvpn_server, params   => [ $kind, \@source, \@dest ] } ,
				'l2tp'          => { function => \&setup_one_l2tp ,          params   => [ $kind, \@source, \@dest ] } ,
				'generic'       => { function => \&setup_one_generic ,       params   => [ $kind, \@source, \@dest ] } ,
			      );

	    $kind = "\L$kind";

	    (my $type) = split /:/, $kind;

	    my $tunnelref = $tunneltypes{ $type };

	    fatal_error "Tunnels of type $type are not supported" unless $tunnelref;

	    $tunnelref->{function}->( $inchainref, $outchainref, @{$tunnelref->{params}} );
	}

	progress_message "   Tunnel \"$currentline\" $done";
    }

    #
    # Setup_Tunnels() Starts Here
    #
    if ( my $fn = open_file( 'tunnels', 1, 1 ) ) {

	first_entry "$doing $fn...";

	while ( read_a_line( NORMAL_READ ) ) {

	    my ( $kind, $zone, $gateway, $gatewayzones ) =
		split_line1( 'tunnels file',
			     { type => 0, zone => 1, gateway => 2, gateways => 2, gateway_zone => 3 , gateway_zones => 3 },
			     {},
			     4 );

	    fatal_error 'TYPE must be specified' if $kind eq '-';

	    fatal_error 'ZONE must be specified' if $zone eq '-';
	    setup_one_tunnel $kind, $zone, $gateway, $gatewayzones;
	}
    }
}

1;
