forked from extern/shorewall_code
5ed65582ee
git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@5621 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb
400 lines
10 KiB
Perl
400 lines
10 KiB
Perl
#
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# Shorewall 3.9 -- /usr/share/shorewall/Shorewall/Nat.pm
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#
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# This program is under GPL [http://www.gnu.org/copyleft/gpl.htm]
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#
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# (c) 2007 - Tom Eastep (teastep@shorewall.net)
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#
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# Complete documentation is available at http://shorewall.net
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of Version 2 of the GNU General Public License
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# as published by the Free Software Foundation.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA
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#
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#
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package Shorewall::Nat;
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require Exporter;
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use Shorewall::Common;
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use Shorewall::Config;
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use Shorewall::Zones;
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use Shorewall::Chains;
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use Shorewall::IPAddrs;
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use strict;
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our @ISA = qw(Exporter);
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our @EXPORT = qw( setup_masq setup_nat add_addresses );
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our @EXPORT_OK = ();
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our @VERSION = 1.00;
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my @addresses_to_add;
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my %addresses_to_add;
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#
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# Handle IPSEC Options in a masq record
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#
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sub do_ipsec_options($)
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{
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my %validoptions = ( strict => NOTHING,
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next => NOTHING,
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reqid => NUMERIC,
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spi => NUMERIC,
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proto => IPSECPROTO,
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mode => IPSECMODE,
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"tunnel-src" => NETWORK,
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"tunnel-dst" => NETWORK,
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);
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my $list=$_[0];
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my $options = '-m policy';
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my $fmt;
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for my $e ( split ',' , $list ) {
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my $val = undef;
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my $invert = '';
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if ( $e =~ /([\w-]+)!=(.+)/ ) {
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$val = $2;
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$e = $1;
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$invert = '! ';
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} elsif ( $e =~ /([\w-]+)=(.+)/ ) {
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$val = $2;
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$e = $1;
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}
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$fmt = $validoptions{$e};
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fatal_error "Invalid Option ($e)" unless $fmt;
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if ( $fmt eq NOTHING ) {
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fatal_error "Option $e does not take a value" if defined $val;
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} else {
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fatal_error "Invalid value ($val) for option \"$e\"" unless $val =~ /^($fmt)$/;
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}
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$options .= $invert;
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$options .= "--$e";
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$options .= " $val" if defined $val;
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}
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$options . ' ';
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}
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#
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# Process a single rule from the the masq file
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#
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sub setup_one_masq($$$$$$)
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{
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my ($fullinterface, $networks, $addresses, $proto, $ports, $ipsec) = @_;
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my $rule = '';
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my $pre_nat;
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my $add_snat_aliases = $config{ADD_SNAT_ALIASES};
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my $destnets = '';
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my $target = '-j MASQUERADE ';
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#
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# Take care of missing ADDRESSES column
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#
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$addresses = '' unless defined $addresses;
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$addresses = '' if $addresses eq '-';
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#
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# Handle IPSEC options, if any
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#
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if ( $ipsec && $ipsec ne '-' ) {
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fatal_error "Non-empty IPSEC column requires policy match support in your kernel and iptables" unless $env{ORIGINAL_POLICY_MATCH};
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if ( $ipsec =~ /^yes$/i ) {
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$rule .= '-m policy --pol ipsec --dir out ';
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} elsif ( $ipsec =~ /^no$/i ) {
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$rule .= '-m policy --pol none --dir out ';
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} else {
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$rule .= do_ipsec_options $ipsec;
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}
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}
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#
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# Leading '+'
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#
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if ( $fullinterface =~ /^\+/ ) {
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$pre_nat = 1;
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$fullinterface =~ s/\+//;
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}
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#
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# Parse the remaining part of the INTERFACE column
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#
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if ( $fullinterface =~ /^([^:]+)::([^:]*)$/ ) {
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$add_snat_aliases = 0;
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$destnets = $2;
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$fullinterface = $1;
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} elsif ( $fullinterface =~ /^([^:]+:[^:]+):([^:]+)$/ ) {
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$destnets = $2;
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$fullinterface = $1;
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} elsif ( $fullinterface =~ /^([^:]+):$/ ) {
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$add_snat_aliases = 0;
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$fullinterface = $1;
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} elsif ( $fullinterface =~ /^([^:]+):([^:]*)$/ ) {
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my ( $one, $two ) = ( $1, $2 );
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if ( $2 =~ /\./ ) {
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$fullinterface = $one;
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$destnets = $two;
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}
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}
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#
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# Isolate and verify the interface part
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#
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( my $interface = $fullinterface ) =~ s/:.*//;
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fatal_error "Unknown interface $interface, rule \"$line\"" unless $interfaces{$interface}{root};
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my $chainref = ensure_chain('nat', $pre_nat ? snat_chain $interface : masq_chain $interface);
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#
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# If there is no source or destination then allow all addresses
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#
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$networks = ALLIPv4 unless $networks;
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$destnets = ALLIPv4 unless $destnets;
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#
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# Handle Protocol and Ports
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#
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$rule .= do_proto $proto, $ports, '';
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my $detectaddress = 0;
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#
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# Parse the ADDRESSES column
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#
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if ( $addresses ) {
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if ( $addresses =~ /^SAME:nodst:/ ) {
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$target = '-j SAME --nodst';
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$addresses =~ s/.*://;
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for my $addr ( split /,/, $addresses ) {
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$target .= "--to $addr ";
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}
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} elsif ( $addresses =~ /^SAME:nodst:/ ) {
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$target = '-j SAME ';
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$addresses =~ s/.*://;
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for my $addr ( split /,/, $addresses ) {
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$target .= "--to $addr ";
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}
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} elsif ( $addresses eq 'detect' ) {
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$target = '-j SNAT $addrlist';
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add_command( $chainref , "addresses=\$(find_interface_addresses $interface); \\" );
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add_command( $chainref , qq([ -z "\$addresses" ] && fatal_error "Unable to determine the IP address(es) of $interface"; \\) );
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add_command( $chainref , 'addrlist=; \\' );
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add_command( $chainref , 'for address in $addresses; do \\' );
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add_command( $chainref , ' addrlist="$addrlist --to-source $address \\";' );
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add_command( $chainref , 'done' );
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} else {
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my $addrlist = '';
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for my $addr ( split /,/, $addresses ) {
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if ( $addr =~ /^.*\..*\..*\./ ) {
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$target = '-j SNAT ';
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$addrlist .= "--to-source $addr ";
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} else {
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$addr =~ s/^://;
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$addrlist .= "--to-ports $addr ";
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}
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}
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$target .= $addrlist;
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}
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} else {
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$add_snat_aliases = 0;
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}
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#
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# And Generate the Rule(s)
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#
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expand_rule $chainref , POSTROUTE_RESTRICT , $rule, $networks, $destnets, '', $target, '', '' , '';
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if ( $add_snat_aliases ) {
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my ( $interface, $alias ) = split /:/, $fullinterface;
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$alias = 0 unless defined $alias;
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for my $address ( split /,/, $addresses ) {
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my ( $addrs, $port ) = split /:/, $address;
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next unless $addrs;
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for my $addr ( ip_range_explicit $addrs ) {
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unless ( $addresses_to_add{$addr} ) {
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emit "del_ip_addr $addr $interface" unless $config{RETAIN_ALIASES};
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$addresses_to_add{$addr} = 1;
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push @addresses_to_add, $addr, "$interface:$alias";
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$alias++;
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}
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}
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}
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}
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progress_message " Masq record \"$line\" $done";
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}
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#
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# Process the masq file
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#
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sub setup_masq()
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{
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open MASQ, "$ENV{TMP_DIR}/masq" or fatal_error "Unable to open stripped zones file: $!";
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while ( $line = <MASQ> ) {
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chomp $line;
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$line =~ s/\s+/ /g;
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my ($fullinterface, $networks, $addresses, $proto, $ports, $ipsec, $extra) = split /\s+/, $line;
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if ( $fullinterface eq 'COMMENT' ) {
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if ( $capabilities{COMMENTS} ) {
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( $comment = $line ) =~ s/^\s*COMMENT\s*//;
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$comment =~ s/\s*$//;
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} else {
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warning_message "COMMENT ignored -- requires comment support in iptables/Netfilter";
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}
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} else {
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fatal_error "Invalid masq file entry: \"$line\"" if $extra;
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setup_one_masq $fullinterface, $networks, $addresses, $proto, $ports, $ipsec;
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}
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}
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close MASQ;
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$comment = '';
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}
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#
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# Validate the ALL INTERFACES or LOCAL column in the NAT file
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#
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sub validate_nat_column( $$ ) {
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my $ref = $_[1];
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my $val = $$ref;
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if ( defined $val ) {
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unless ( ( $val = "\L$val" ) eq 'yes' ) {
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if ( ( $val eq 'no' ) || ( $val eq '-' ) ) {
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$$ref = '';
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} else {
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fatal_error "Invalid value ($val) for $_[0] in NAT entry \"$line\"";
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}
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}
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} else {
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$$ref = '';
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}
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}
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#
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# Process a record from the NAT file
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#
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sub do_one_nat( $$$$$ )
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{
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my ( $external, $interface, $internal, $allints, $localnat ) = @_;
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sub add_nat_rule( $$ ) {
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add_rule ensure_chain( 'nat', $_[0] ) , $_[1];
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}
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my $add_ip_aliases = $config{ADD_IP_ALIASES};
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my $policyin = '';
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my $policyout = '';
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if ( $capabilities{POLICY_MATCH} ) {
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$policyin = ' -m policy --pol none --dir in';
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$policyout = '-m policy --pol none --dir out';
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}
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fatal_error "Invalid nat file entry \"$line\""
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unless defined $interface and defined $internal;
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if ( $add_ip_aliases ) {
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if ( $interface =~ s/:$// ) {
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$add_ip_aliases = '';
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} else {
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my ( $iface , undef ) = split /:/, $interface;
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emit "del_ip_addr $external $iface" unless $config{RETAIN_ALIASES};
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}
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} else {
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$interface =~ s/:$//;
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}
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validate_nat_column 'ALL INTERFACES', \$allints;
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validate_nat_column 'LOCAL' , \$localnat;
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if ( $allints ) {
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add_nat_rule 'nat_in' , "-d $external $policyin -j DNAT --to-destination $internal";
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add_nat_rule 'nat_out' , "-s $internal $policyout -j SNAT --to-source $external";
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} else {
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add_nat_rule input_chain( $interface ) , "-d $external $policyin -j DNAT --to-destination $internal";
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add_nat_rule output_chain( $interface ) , "-s $internal $policyout -j SNAT --to-source $external";
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}
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add_nat_rule 'OUTPUT' , "-d $external$policyout -j DNAT --to-destination $internal " if $localnat;
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if ( $add_ip_aliases ) {
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unless ( $addresses_to_add{$external} ) {
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$addresses_to_add{$external} = 1;
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push @addresses_to_add, "$external $interface";
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}
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}
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progress_message " NAT entry \"$line\" $done";
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}
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#
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# Process NAT file
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#
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sub setup_nat() {
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open NAT, "$ENV{TMP_DIR}/nat" or fatal_error "Unable to open stripped nat file: $!";
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while ( $line = <NAT> ) {
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chomp $line;
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$line =~ s/\s+/ /g;
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my ( $external, $interface, $internal, $allints, $localnat, $extra ) = split /\s+/, $line;
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if ( $external eq 'COMMENT' ) {
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if ( $capabilities{COMMENTS} ) {
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( $comment = $line ) =~ s/^\s*COMMENT\s*//;
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$comment =~ s/\s*$//;
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} else {
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warning_message "COMMENT ignored -- requires comment support in iptables/Netfilter";
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}
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} else {
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fatal_error "Invalid nat file entry: \"$line\"" if $extra;
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do_one_nat $external, $interface, $internal, $allints, $localnat;
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}
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}
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close NAT;
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$comment = '';
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}
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sub add_addresses () {
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if ( @addresses_to_add ) {
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my $arg = '';
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while ( @addresses_to_add ) {
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my $addr = shift @addresses_to_add;
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my $interface = shift @addresses_to_add;
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$arg = "$arg $addr $interface";
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}
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emit "add_ip_aliases $arg";
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}
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}
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1;
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