shorewall_code/Shorewall-perl/Shorewall/Rules.pm

2093 lines
62 KiB
Perl

#
# Shorewall-perl 4.2 -- /usr/share/shorewall-perl/Shorewall/Rules.pm
#
# This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
# (c) 2007,2008 - Tom Eastep (teastep@shorewall.net)
#
# Complete documentation is available at http://shorewall.net
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of Version 2 of the GNU General Public License
# as published by the Free Software Foundation.
#
# 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# This module contains the high-level code for dealing with rules.
#
package Shorewall::Rules;
require Exporter;
use Shorewall::Config qw(:DEFAULT :internal);
use Shorewall::IPAddrs;
use Shorewall::Zones;
use Shorewall::Chains qw(:DEFAULT :internal);
use Shorewall::Actions;
use Shorewall::Policy;
use Shorewall::Proc;
use strict;
our @ISA = qw(Exporter);
our @EXPORT = qw( process_tos
setup_ecn
add_common_rules
setup_mac_lists
process_criticalhosts
process_routestopped
process_rules
generate_matrix
setup_mss
);
our @EXPORT_OK = qw( process_rule process_rule1 initialize );
our $VERSION = 4.3.0;
#
# Set to one if we find a SECTION
#
our $sectioned;
our $macro_nest_level;
our $current_param;
our @param_stack;
our $family;
#
# When splitting a line in the rules file, don't pad out the columns with '-' if the first column contains one of these
#
my %rules_commands = ( COMMENT => 0,
SECTION => 2 );
#
# Initialize globals -- we take this novel approach to globals initialization to allow
# the compiler to run multiple times in the same process. The
# initialize() function does globals initialization for this
# module and is called from an INIT block below. The function is
# also called by Shorewall::Compiler::compiler at the beginning of
# the second and subsequent calls to that function.
#
sub initialize( $ ) {
$family = shift;
$sectioned = 0;
$macro_nest_level = 0;
$current_param = '';
@param_stack = ();
}
INIT {
initialize( F_IPV4 );
}
use constant { MAX_MACRO_NEST_LEVEL => 5 };
sub process_tos() {
my $chain = $capabilities{MANGLE_FORWARD} ? 'fortos' : 'pretos';
my $stdchain = $capabilities{MANGLE_FORWARD} ? 'FORWARD' : 'PREROUTING';
my %tosoptions = ( 'minimize-delay' => 0x10 ,
'maximize-throughput' => 0x08 ,
'maximize-reliability' => 0x04 ,
'minimize-cost' => 0x02 ,
'normal-service' => 0x00 );
if ( my $fn = open_file 'tos' ) {
my $first_entry = 1;
my ( $pretosref, $outtosref );
first_entry( sub { progress_message2 "$doing $fn..."; $pretosref = ensure_chain 'mangle' , $chain; $outtosref = ensure_chain 'mangle' , 'outtos'; } );
while ( read_a_line ) {
my ($src, $dst, $proto, $sports, $ports , $tos, $mark ) = split_line 6, 7, 'tos file entry';
$first_entry = 0;
fatal_error 'A value must be supplied in the TOS column' if $tos eq '-';
if ( defined ( my $tosval = $tosoptions{"\L$tos"} ) ) {
$tos = $tosval;
} else {
my $val = numeric_value( $tos );
fatal_error "Invalid TOS value ($tos)" unless defined( $val ) && $val < 0x1f;
}
my $chainref;
my $restriction = NO_RESTRICT;
my ( $srczone , $source , $remainder );
if ( $family == F_IPV4 ) {
( $srczone , $source , $remainder ) = split( /:/, $src, 3 );
fatal_error 'Invalid SOURCE' if defined $remainder;
} elsif ( $src =~ /^(.+?):\[(.*)]\s*$/ ) {
$srczone = $1;
$source = $2;
} else {
$srczone = $src;
}
if ( $srczone eq firewall_zone ) {
$chainref = $outtosref;
$src = $source || '-';
$restriction = OUTPUT_RESTRICT;
} else {
$chainref = $pretosref;
$src =~ s/^all:?//;
}
$dst =~ s/^all:?//;
expand_rule
$chainref ,
$restriction ,
do_proto( $proto, $ports, $sports ) . do_test( $mark , 0xFF ) ,
$src ,
$dst ,
'' ,
'' ,
"-j TOS --set-tos $tos" ,
'' ,
'' ,
'';
}
unless ( $first_entry ) {
add_rule $mangle_table->{$stdchain}, "-j $chain" if $pretosref->{referenced};
add_rule $mangle_table->{OUTPUT}, "-j outtos" if $outtosref->{referenced};
}
}
}
#
# Setup ECN disabling rules
#
sub setup_ecn()
{
my %interfaces;
my @hosts;
if ( my $fn = open_file 'ecn' ) {
first_entry "$doing $fn...";
while ( read_a_line ) {
my ($interface, $hosts ) = split_line 1, 2, 'ecn file entry';
fatal_error "Unknown interface ($interface)" unless known_interface $interface;
$interfaces{$interface} = 1;
$hosts = ALLIP if $hosts eq '-';
for my $host( split_list $hosts, 'address' ) {
validate_host( $host , 1 );
push @hosts, [ $interface, $host ];
}
}
if ( @hosts ) {
my @interfaces = ( keys %interfaces );
progress_message "$doing ECN control on @interfaces...";
for my $interface ( @interfaces ) {
my $chainref = ensure_chain 'mangle', ecn_chain( $interface );
add_jump $mangle_table->{POSTROUTING} , $chainref, 0, "-p tcp -o $interface ";
add_jump $mangle_table->{OUTPUT}, $chainref, 0, "-p tcp -o $interface ";
}
for my $host ( @hosts ) {
add_rule $mangle_table->{ecn_chain $host->[0]}, join ('', '-p tcp ', match_dest_net( $host->[1] ) , ' -j ECN --ecn-tcp-remove' );
}
}
}
}
sub add_rule_pair( $$$$ ) {
my ($chainref , $predicate , $target , $level ) = @_;
log_rule( $level, $chainref, "\U$target", $predicate ) if defined $level && $level ne '';
add_rule $chainref , "${predicate}-j $target";
}
sub setup_rfc1918_filteration( $ ) {
my $listref = $_[0];
my $norfc1918ref = new_standard_chain 'norfc1918';
my $rfc1918ref = new_standard_chain 'rfc1918';
my $chainref = $norfc1918ref;
warning_message q(The 'norfc1918' option is deprecated);
log_rule $config{RFC1918_LOG_LEVEL} , $rfc1918ref , 'DROP' , '';
add_rule $rfc1918ref , '-j DROP';
$chainref = new_standard_chain 'rfc1918d' if $config{RFC1918_STRICT};
my $fn = open_file 'rfc1918';
first_entry "$doing $fn...";
while ( read_a_line ) {
require_capability 'CONNTRACK_MATCH', "The norfc1918 option" , 's';
my ( $networks, $target ) = split_line 2, 2, 'rfc1918 file';
my $s_target;
if ( $target eq 'logdrop' ) {
$target = 'rfc1918';
$s_target = 'rfc1918';
} elsif ( $target eq 'DROP' ) {
$s_target = 'DROP';
} elsif ( $target eq 'RETURN' ) {
$s_target = $config{RFC1918_STRICT} ? 'rfc1918d' : 'RETURN';
} else {
fatal_error "Invalid target ($target) for $networks";
}
for my $network ( split_list $networks, 'network' ) {
add_rule $norfc1918ref , match_source_net( $network ) . "-j $s_target";
add_rule $chainref , match_orig_dest( $network ) . "-j $target" ;
}
}
add_rule $norfc1918ref , '-j rfc1918d' if $config{RFC1918_STRICT};
for my $hostref ( @$listref ) {
my $interface = $hostref->[0];
my $ipsec = $hostref->[1];
my $policy = $capabilities{POLICY_MATCH} ? "-m policy --pol $ipsec --dir in " : '';
for my $chain ( first_chains $interface ) {
add_rule $filter_table->{$chain} , join( '', '-m state --state NEW ', match_source_net( $hostref->[2]) , "${policy}-j norfc1918" );
}
}
}
sub setup_blacklist() {
my $hosts = find_hosts_by_option 'blacklist';
my $chainref;
my ( $level, $disposition ) = @config{'BLACKLIST_LOGLEVEL', 'BLACKLIST_DISPOSITION' };
my $target = $disposition eq 'REJECT' ? 'reject' : $disposition;
if ( @$hosts ) {
$chainref = new_standard_chain 'blacklst';
if ( defined $level && $level ne '' ) {
my $logchainref = new_standard_chain 'blacklog';
log_rule_limit( $level , $logchainref , 'blacklst' , $disposition , "$globals{LOGLIMIT}" , '', 'add', '' );
add_rule $logchainref, "-j $target" ;
$target = 'blacklog';
}
}
BLACKLIST:
{
if ( my $fn = open_file 'blacklist' ) {
my $first_entry = 1;
first_entry "$doing $fn...";
while ( read_a_line ) {
if ( $first_entry ) {
unless ( @$hosts ) {
warning_message q(The entries in $fn have been ignored because there are no 'blacklist' interfaces);
close_file;
last BLACKLIST;
}
$first_entry = 0;
}
my ( $networks, $protocol, $ports ) = split_line 1, 3, 'blacklist file';
expand_rule(
$chainref ,
NO_RESTRICT ,
do_proto( $protocol , $ports, '' ) ,
$networks ,
'' ,
'' ,
'' ,
"-j $target" ,
'' ,
$disposition ,
'' );
progress_message " \"$currentline\" added to blacklist";
}
}
my $state = $config{BLACKLISTNEWONLY} ? '-m state --state NEW,INVALID ' : '';
for my $hostref ( @$hosts ) {
my $interface = $hostref->[0];
my $ipsec = $hostref->[1];
my $policy = $capabilities{POLICY_MATCH} ? "-m policy --pol $ipsec --dir in " : '';
my $network = $hostref->[2];
my $source = match_source_net $network;
for my $chain ( first_chains $interface ) {
add_rule $filter_table->{$chain} , "${source}${state}${policy}-j blacklst";
}
progress_message " Blacklisting enabled on ${interface}:${network}";
}
}
}
sub process_criticalhosts() {
my @critical = ();
my $fn = open_file 'routestopped';
first_entry "$doing $fn for critical hosts...";
while ( read_a_line ) {
my $routeback = 0;
my ($interface, $hosts, $options ) = split_line 1, 3, 'routestopped file';
fatal_error "Unknown interface ($interface)" unless known_interface $interface;
$hosts = ALLIP unless $hosts ne '-';
my @hosts;
for my $host ( split_list $hosts, 'host' ) {
validate_host $host, 1;
push @hosts, "$interface:$host";
}
unless ( $options eq '-' ) {
for my $option (split_list $options, 'option' ) {
unless ( $option eq 'routeback' || $option eq 'source' || $option eq 'dest' ) {
if ( $option eq 'critical' ) {
push @critical, @hosts;
} else {
warning_message "Unknown routestopped option ( $option ) ignored";
}
}
}
}
}
\@critical;
}
sub process_routestopped() {
my ( @allhosts, %source, %dest );
my $fn = open_file 'routestopped';
first_entry "$doing $fn...";
while ( read_a_line ) {
my $routeback = 0;
my ($interface, $hosts, $options ) = split_line 1, 3, 'routestopped file';
fatal_error "Unknown interface ($interface)" unless known_interface $interface;
$hosts = ALLIP unless $hosts && $hosts ne '-';
my @hosts;
for my $host ( split /,/, $hosts ) {
validate_host $host, 1;
push @hosts, "$interface:$host";
}
unless ( $options eq '-' ) {
for my $option (split /,/, $options ) {
if ( $option eq 'routeback' ) {
if ( $routeback ) {
warning_message "Duplicate 'routeback' option ignored";
} else {
$routeback = 1;
for my $host ( split /,/, $hosts ) {
my $source = match_source_net $host;
my $dest = match_dest_net $host;
emit "run_iptables -A FORWARD -i $interface -o $interface $source $dest -j ACCEPT";
clearrule;
}
}
} elsif ( $option eq 'source' ) {
for my $host ( split /,/, $hosts ) {
$source{"$interface:$host"} = 1;
}
} elsif ( $option eq 'dest' ) {
for my $host ( split /,/, $hosts ) {
$dest{"$interface:$host"} = 1;
}
} else {
warning_message "Unknown routestopped option ( $option ) ignored" unless $option eq 'critical';
}
}
}
push @allhosts, @hosts;
}
for my $host ( @allhosts ) {
my ( $interface, $h ) = split /:/, $host;
my $source = match_source_net $h;
my $dest = match_dest_net $h;
my $sourcei = match_source_dev $interface;
my $desti = match_dest_dev $interface;
emit "\$IPTABLES -A INPUT $sourcei $source -j ACCEPT";
emit "\$IPTABLES -A OUTPUT $desti $dest -j ACCEPT" unless $config{ADMINISABSENTMINDED};
my $matched = 0;
if ( $source{$host} ) {
emit "\$IPTABLES -A FORWARD $sourcei $source -j ACCEPT";
$matched = 1;
}
if ( $dest{$host} ) {
emit "\$IPTABLES -A FORWARD $desti $dest -j ACCEPT";
$matched = 1;
}
unless ( $matched ) {
for my $host1 ( @allhosts ) {
unless ( $host eq $host1 ) {
my ( $interface1, $h1 ) = split /:/, $host1;
my $dest1 = match_dest_net $h1;
my $desti1 = match_dest_dev $interface1;
emit "\$IPTABLES -A FORWARD $sourcei $desti1 $source $dest1 -j ACCEPT";
clearrule;
}
}
}
}
}
sub setup_mss();
sub add_common_rules() {
my $interface;
my $chainref;
my $level;
my $target;
my $rule;
my $list;
my $chain;
new_standard_chain 'dynamic';
my $state = $config{BLACKLISTNEWONLY} ? '-m state --state NEW,INVALID ' : '';
add_rule $filter_table->{$_}, "$state -j dynamic" for qw( INPUT FORWARD );
setup_mss;
if ( $config{FASTACCEPT} ) {
add_rule( $filter_table->{$_} , "-m state --state ESTABLISHED,RELATED -j ACCEPT" ) for qw( INPUT FORWARD OUTPUT );
}
my $rejectref = new_standard_chain 'reject';
$level = $config{BLACKLIST_LOGLEVEL};
add_rule_pair new_standard_chain( 'logdrop' ), ' ' , 'DROP' , $level ;
add_rule_pair new_standard_chain( 'logreject' ), ' ' , 'reject' , $level ;
for $interface ( all_interfaces ) {
ensure_chain( 'filter', $_ ) for first_chains( $interface ), output_chain( $interface );
}
run_user_exit1 'initdone';
setup_blacklist;
$list = find_hosts_by_option 'nosmurfs';
$chainref = new_standard_chain 'smurfs';
if ( $family == F_IPV4 ) {
if ( $capabilities{ADDRTYPE} ) {
add_rule $chainref , '-s 0.0.0.0 -j RETURN';
add_rule_pair $chainref, '-m addrtype --src-type BROADCAST ', 'DROP', $config{SMURF_LOG_LEVEL} ;
} else {
add_command $chainref, 'for address in $ALL_BCASTS; do';
incr_cmd_level $chainref;
log_rule( $config{SMURF_LOG_LEVEL} , $chainref, 'DROP', '-s $address ' );
add_rule $chainref, '-s $address -j DROP';
decr_cmd_level $chainref;
add_command $chainref, 'done';
}
add_rule_pair $chainref, '-s 224.0.0.0/4 ', 'DROP', $config{SMURF_LOG_LEVEL} ;
if ( $capabilities{ADDRTYPE} ) {
add_rule $rejectref , '-m addrtype --src-type BROADCAST -j DROP';
} else {
add_command $rejectref, 'for address in $ALL_BCASTS; do';
incr_cmd_level $rejectref;
add_rule $rejectref, '-d $address -j DROP';
decr_cmd_level $rejectref;
add_command $rejectref, 'done';
}
add_rule $rejectref , '-s 224.0.0.0/4 -j DROP';
} else {
my $predicate = '-s ' . IPv6_MULTICAST . ' ';
add_rule_pair $chainref , $predicate, 'DROP' , $config{SMURF_LOG_LEVEL};
add_rule $rejectref, "$predicate -j DROP";
}
if ( @$list ) {
progress_message2 'Adding Anti-smurf Rules';
for my $hostref ( @$list ) {
$interface = $hostref->[0];
my $ipsec = $hostref->[1];
my $policy = $capabilities{POLICY_MATCH} ? "-m policy --pol $ipsec --dir in " : '';
for $chain ( first_chains $interface ) {
add_rule $filter_table->{$chain} , join( '', '-m state --state NEW,INVALID ', match_source_net( $hostref->[2] ), "${policy}-j smurfs" );
}
}
}
add_rule $rejectref , '-p 2 -j DROP';
add_rule $rejectref , '-p 6 -j REJECT --reject-with tcp-reset';
if ( $capabilities{ENHANCED_REJECT} ) {
add_rule $rejectref , '-p 17 -j REJECT';
if ( $family == F_IPV4 ) {
add_rule $rejectref, '-p 1 -j REJECT --reject-with icmp-host-unreachable';
add_rule $rejectref, '-j REJECT --reject-with icmp-host-prohibited';
} else {
add_rule $rejectref, '-p 58 -j REJECT --reject-with icmp6-addr-unreachable';
add_rule $rejectref, '-j REJECT --reject-with icmp6-adm-prohibited';
}
} else {
add_rule $rejectref , '-j REJECT';
}
if ( $family == F_IPV4 ) {
$list = find_interfaces_by_option 'dhcp';
if ( @$list ) {
progress_message2 'Adding rules for DHCP';
for $interface ( @$list ) {
for $chain ( input_chain $interface, output_chain $interface ) {
add_rule $filter_table->{$chain} , '-p udp --dport 67:68 -j ACCEPT';
}
add_rule $filter_table->{forward_chain $interface} , "-p udp -o $interface --dport 67:68 -j ACCEPT" if get_interface_option( $interface, 'bridge' );
}
}
$list = find_hosts_by_option 'norfc1918';
setup_rfc1918_filteration $list if @$list;
}
$list = find_hosts_by_option 'tcpflags';
if ( @$list ) {
my $disposition;
progress_message2 "$doing TCP Flags filtering...";
$chainref = new_standard_chain 'tcpflags';
if ( $config{TCP_FLAGS_LOG_LEVEL} ne '' ) {
my $logflagsref = new_standard_chain 'logflags';
my $savelogparms = $globals{LOGPARMS};
$globals{LOGPARMS} = "$globals{LOGPARMS}--log-ip-options ";
log_rule $config{TCP_FLAGS_LOG_LEVEL} , $logflagsref , $config{TCP_FLAGS_DISPOSITION}, '';
$globals{LOGPARMS} = $savelogparms;
if ( $config{TCP_FLAGS_DISPOSITION} eq 'REJECT' ) {
add_rule $logflagsref , '-j REJECT --reject-with tcp-reset';
} else {
add_rule $logflagsref , "-j $config{TCP_FLAGS_DISPOSITION}";
}
$disposition = 'logflags';
} else {
$disposition = $config{TCP_FLAGS_DISPOSITION};
}
add_rule $chainref , "-p tcp --tcp-flags ALL FIN,URG,PSH -j $disposition";
add_rule $chainref , "-p tcp --tcp-flags ALL NONE -j $disposition";
add_rule $chainref , "-p tcp --tcp-flags SYN,RST SYN,RST -j $disposition";
add_rule $chainref , "-p tcp --tcp-flags SYN,FIN SYN,FIN -j $disposition";
add_rule $chainref , "-p tcp --syn --sport 0 -j $disposition";
for my $hostref ( @$list ) {
my $policy = $capabilities{POLICY_MATCH} ? "-m policy --pol $hostref->[1] --dir in " : '';
for $chain ( first_chains $hostref->[0] ) {
add_rule $filter_table->{$chain} , join( '', '-p tcp ', match_source_net( $hostref->[2] ), "${policy}-j tcpflags" );
}
}
}
if ( $family == F_IPV4 ) {
$list = find_interfaces_by_option 'upnp';
if ( @$list ) {
progress_message2 '$doing UPnP';
new_nat_chain( 'UPnP' );
for $interface ( @$list ) {
add_rule $nat_table->{PREROUTING} , match_source_dev ( $interface ) . '-j UPnP';
}
}
}
setup_syn_flood_chains;
}
my %maclist_targets = ( ACCEPT => { target => 'RETURN' , mangle => 1 } ,
REJECT => { target => 'reject' , mangle => 0 } ,
DROP => { target => 'DROP' , mangle => 1 } );
sub setup_mac_lists( $ ) {
my $phase = $_[0];
my %maclist_interfaces;
my $table = $config{MACLIST_TABLE};
my $maclist_hosts = find_hosts_by_option 'maclist';
my $target = $globals{MACLIST_TARGET};
my $level = $config{MACLIST_LOG_LEVEL};
my $disposition = $config{MACLIST_DISPOSITION};
my $ttl = $config{MACLIST_TTL};
progress_message2 "$doing MAC Filtration -- Phase $phase...";
for my $hostref ( @$maclist_hosts ) {
$maclist_interfaces{ $hostref->[0] } = 1;
}
my @maclist_interfaces = ( sort keys %maclist_interfaces );
progress_message " $doing MAC Verification for @maclist_interfaces -- Phase $phase...";
if ( $phase == 1 ) {
for my $interface ( @maclist_interfaces ) {
my $chainref = new_chain $table , mac_chain $interface;
add_rule $chainref , '-s 0.0.0.0 -d 255.255.255.255 -p udp --dport 67:68 -j RETURN'
if ( $table eq 'mangle' ) && get_interface_option( $interface, 'dhcp' );
if ( $ttl ) {
my $chain1ref = new_chain $table, macrecent_target $interface;
my $chain = $chainref->{name};
add_rule $chainref, "-m recent --rcheck --seconds $ttl --name $chain -j RETURN";
add_rule $chainref, "-j $chain1ref->{name}";
add_rule $chainref, "-m recent --update --name $chain -j RETURN";
add_rule $chainref, "-m recent --set --name $chain";
}
}
my $fn = open_file 'maclist';
first_entry "$doing $fn...";
while ( read_a_line ) {
my ( $original_disposition, $interface, $mac, $addresses ) = split_line1 3, 4, 'maclist file';
if ( $original_disposition eq 'COMMENT' ) {
process_comment;
} else {
my ( $disposition, $level, $remainder) = split( /:/, $original_disposition, 3 );
fatal_error "Invalid DISPOSITION ($original_disposition)" if defined $remainder || ! $disposition;
my $targetref = $maclist_targets{$disposition};
fatal_error "Invalid DISPOSITION ($original_disposition)" if ! $targetref || ( ( $table eq 'mangle' ) && ! $targetref->{mangle} );
fatal_error "Unknown Interface ($interface)" unless known_interface( $interface );
fatal_error "No hosts on $interface have the maclist option specified" unless $maclist_interfaces{$interface};
my $chainref = $chain_table{$table}{( $ttl ? macrecent_target $interface : mac_chain $interface )};
$mac = '' unless $mac && ( $mac ne '-' );
$addresses = '' unless defined $addresses && ( $addresses ne '-' );
fatal_error "You must specify a MAC address or an IP address" unless $mac || $addresses;
$mac = mac_match $mac if $mac;
if ( $addresses ) {
for my $address ( split ',', $addresses ) {
my $source = match_source_net $address;
log_rule_limit $level, $chainref , mac_chain( $interface) , $disposition, '', '', 'add' , "${mac}${source}"
if defined $level && $level ne '';
add_rule $chainref , "${mac}${source}-j $targetref->{target}";
}
} else {
log_rule_limit $level, $chainref , mac_chain( $interface) , $disposition, '', '', 'add' , $mac
if defined $level && $level ne '';
add_rule $chainref , "$mac-j $targetref->{target}";
}
progress_message " Maclist entry \"$currentline\" $done";
}
}
clear_comment;
#
# Generate jumps from the input and forward chains
#
for my $hostref ( @$maclist_hosts ) {
my $interface = $hostref->[0];
my $ipsec = $hostref->[1];
my $policy = $capabilities{POLICY_MATCH} ? "-m policy --pol $ipsec --dir in " : '';
my $source = match_source_net $hostref->[2];
my $target = mac_chain $interface;
if ( $table eq 'filter' ) {
for my $chain ( first_chains $interface ) {
add_rule $filter_table->{$chain} , "${source}-m state --state NEW ${policy}-j $target";
}
} else {
add_rule $mangle_table->{PREROUTING}, match_source_dev( $interface ) . "${source}-m state --state NEW ${policy}-j $target";
}
}
} else {
for my $interface ( @maclist_interfaces ) {
my $chainref = $chain_table{$table}{( $ttl ? macrecent_target $interface : mac_chain $interface )};
my $chain = $chainref->{name};
if ( $level ne '' || $disposition ne 'ACCEPT' ) {
my $variable = get_interface_addresses source_port_to_bridge( $interface );
if ( $capabilities{ADDRTYPE} ) {
add_commands( $chainref,
"for address in $variable; do",
" echo \"-A $chainref->{name} -s \$address -m addrtype --dst-type BROADCAST -j RETURN\" >&3",
" echo \"-A $chainref->{name} -s \$address -d 224.0.0.0/4 -j RETURN\" >&3",
'done' );
} else {
my $bridge = source_port_to_bridge( $interface );
my $bridgeref = find_interface( $bridge );
add_commands( $chainref,
"for address in $variable; do" );
if ( $family == F_IPV4 ) {
if ( $bridgeref->{broadcasts} ) {
for my $address ( @{$bridgeref->{broadcasts}}, '255.255.255.255' ) {
add_commands( $chainref ,
" echo \"-A $chainref->{name} -s \$address -d $address -j RETURN\" >&3" );
}
} else {
my $variable1 = get_interface_bcasts $bridge;
add_commands( $chainref,
" for address1 in $variable1; do" ,
" echo \"-A $chainref->{name} -s \$address -d \$address1 -j RETURN\" >&3",
" done" );
}
add_commands( $chainref, " echo \"-A $chainref->{name} -s \$address -d 224.0.0.0/4 -j RETURN\" >&3" );
} else {
my $variable1 = get_interface_bcasts $bridge;
add_commands( $chainref,
" for address1 in $variable1; do" ,
" echo \"-A $chainref->{name} -s \$address -d \$address1 -j RETURN\" >&3",
" done" );
}
add_command( $chainref, 'done' );
}
}
run_user_exit2( 'maclog', $chainref );
log_rule_limit $level, $chainref , $chain , $disposition, '', '', 'add', '' if $level ne '';
add_rule $chainref, "-j $target";
}
}
}
sub process_rule1 ( $$$$$$$$$$$$$ );
#
# Expand a macro rule from the rules file
#
sub process_macro ( $$$$$$$$$$$$$$$ ) {
my ($macro, $target, $param, $source, $dest, $proto, $ports, $sports, $origdest, $rate, $user, $mark, $connlimit, $time, $wildcard ) = @_;
my $nocomment = no_comment;
my $format = 1;
macro_comment $macro;
my $macrofile = $macros{$macro};
progress_message "..Expanding Macro $macrofile...";
push_open $macrofile;
while ( read_a_line ) {
my ( $mtarget, $msource, $mdest, $mproto, $mports, $msports, $morigdest, $mrate, $muser );
if ( $format == 1 ) {
( $mtarget, $msource, $mdest, $mproto, $mports, $msports, $mrate, $muser, $morigdest ) = split_line1 1, 9, 'macro file', $macro_commands;
} else {
( $mtarget, $msource, $mdest, $mproto, $mports, $msports, $morigdest, $mrate, $muser ) = split_line1 1, 9, 'macro file', $macro_commands;
}
if ( $mtarget eq 'COMMENT' ) {
process_comment unless $nocomment;
next;
}
if ( $mtarget eq 'FORMAT' ) {
fatal_error "Invalid FORMAT ($msource)" unless $msource =~ /^[12]$/;
$format = $msource;
next;
}
fatal_error "Invalid macro file entry (too many columns)" if $morigdest ne '-' && $format == 1;
$mtarget = merge_levels $target, $mtarget;
if ( $mtarget =~ /^PARAM(:.*)?$/ ) {
fatal_error 'PARAM requires a parameter to be supplied in macro invocation' unless $param ne '';
$mtarget = substitute_param $param, $mtarget;
}
my $action = isolate_basic_target $mtarget;
fatal_error "Invalid or missing ACTION ($mtarget)" unless defined $action;
my $actiontype = $targets{$action} || find_macro( $action );
fatal_error "Invalid Action ($mtarget) in macro" unless $actiontype & ( ACTION + STANDARD + NATRULE + MACRO );
if ( $msource ) {
if ( $msource eq '-' ) {
$msource = $source || '';
} elsif ( $msource =~ s/^DEST:?// ) {
$msource = merge_macro_source_dest $msource, $dest;
} else {
$msource =~ s/^SOURCE:?//;
$msource = merge_macro_source_dest $msource, $source;
}
} else {
$msource = '';
}
if ( $mdest ) {
if ( $mdest eq '-' ) {
$mdest = $dest || '';
} elsif ( $mdest =~ s/^SOURCE:?// ) {
$mdest = merge_macro_source_dest $mdest , $source;
} else {
$mdest =~ s/DEST:?//;
$mdest = merge_macro_source_dest $mdest, $dest;
}
} else {
$mdest = '';
}
process_rule1(
$mtarget,
$msource,
$mdest,
merge_macro_column( $mproto, $proto ) ,
merge_macro_column( $mports, $ports ) ,
merge_macro_column( $msports, $sports ) ,
merge_macro_column( $morigdest, $origdest ) ,
merge_macro_column( $mrate, $rate ) ,
merge_macro_column( $muser, $user ) ,
$mark,
$connlimit,
$time,
$wildcard
);
progress_message " Rule \"$currentline\" $done";
}
pop_open;
progress_message "..End Macro $macrofile";
clear_comment unless $nocomment;
}
#
# Once a rule has been expanded via wildcards (source and/or dest zone == 'all'), it is processed by this function. If
# the target is a macro, the macro is expanded and this function is called recursively for each rule in the expansion.
#
sub process_rule1 ( $$$$$$$$$$$$$ ) {
my ( $target, $source, $dest, $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit, $time, $wildcard ) = @_;
my ( $action, $loglevel) = split_action $target;
my ( $basictarget, $param ) = get_target_param $action;
my $rule = '';
my $actionchainref;
my $optimize = $wildcard ? ( $basictarget =~ /!$/ ? 0 : $config{OPTIMIZE} ) : 0;
unless ( defined $param ) {
( $basictarget, $param ) = ( $1, $2 ) if $action =~ /^(\w+)[(](.*)[)]$/;
}
$param = '' unless defined $param;
#
# Determine the validity of the action
#
my $actiontype = $targets{$basictarget} || find_macro( $basictarget );
fatal_error "Unknown action ($action)" unless $actiontype;
if ( $actiontype == MACRO ) {
#
# process_macro() will call process_rule1() recursively for each rule in the macro body
#
fatal_error "Macro invocations nested too deeply" if ++$macro_nest_level > MAX_MACRO_NEST_LEVEL;
if ( $param ne '' ) {
push @param_stack, $current_param;
$current_param = $param;
}
process_macro( $basictarget,
$target ,
$current_param,
$source,
$dest,
$proto,
$ports,
$sports,
$origdest,
$ratelimit,
$user,
$mark,
$connlimit,
$time,
$wildcard );
$macro_nest_level--;
$current_param = pop @param_stack if $param ne '';
return;
} elsif ( $actiontype & NFQ ) {
require_capability( 'NFQUEUE_TARGET', 'NFQUEUE Rules', '' );
my $paramval = $param eq '' ? 0 : numeric_value( $param );
fatal_error "Invalid value ($param) for NFQUEUE queue number" unless defined($paramval) && $paramval <= 65535;
$action = "NFQUEUE --queue-num $paramval";
} else {
fatal_error "The $basictarget TARGET does not accept a parameter" unless $param eq '';
}
#
# We can now dispense with the postfix character
#
$action =~ s/[\+\-!]$//;
#
# Mark target as used
#
if ( $actiontype & ACTION ) {
unless ( $usedactions{$target} ) {
$usedactions{$target} = 1;
createactionchain $target;
}
}
#
# Take care of irregular syntax and targets
#
if ( $actiontype & REDIRECT ) {
my $z = $actiontype & NATONLY ? '' : firewall_zone;
if ( $dest eq '-' ) {
$dest = join( '', $z, '::' , $ports =~ /[:,]/ ? '' : $ports );
} else {
$dest = join( '', $z, '::', $dest ) unless $dest =~ /:/;
}
} elsif ( $action eq 'REJECT' ) {
$action = 'reject';
} elsif ( $action eq 'CONTINUE' ) {
$action = 'RETURN';
} elsif ( $actiontype & LOGRULE ) {
fatal_error 'LOG requires a log level' unless defined $loglevel and $loglevel ne '';
}
#
# Isolate and validate source and destination zones
#
my $sourcezone;
my $destzone;
my $sourceref;
my $destref;
my $origdstports;
if ( $source =~ /^(.+?):(.*)/ ) {
fatal_error "Missing SOURCE Qualifier ($source)" if $2 eq '';
$sourcezone = $1;
$source = $2;
} else {
$sourcezone = $source;
$source = ALLIP;
}
if ( $dest =~ /^(.*?):(.*)/ ) {
fatal_error "Missing DEST Qualifier ($dest)" if $2 eq '';
$destzone = $1;
$dest = $2;
} elsif ( $dest =~ /.*\..*\./ ) {
#
# Appears to be an address
#
$destzone = '-';
} else {
$destzone = $dest;
$dest = ALLIP;
}
fatal_error "Missing source zone" if $sourcezone eq '-' || $sourcezone =~ /^:/;
fatal_error "Unknown source zone ($sourcezone)" unless $sourceref = defined_zone( $sourcezone );
if ( $actiontype & NATONLY ) {
warning_message "Destination zone ($destzone) ignored" unless $destzone eq '-' || $destzone eq '';
} else {
fatal_error "Missing destination zone" if $destzone eq '-' || $destzone eq '';
fatal_error "Unknown destination zone ($destzone)" unless $destref = defined_zone( $destzone );
}
my $restriction = NO_RESTRICT;
if ( $sourcezone eq firewall_zone ) {
$restriction = $destzone eq firewall_zone ? ALL_RESTRICT : OUTPUT_RESTRICT;
} else {
$restriction = INPUT_RESTRICT if $destzone eq firewall_zone;
}
my ( $chain, $chainref, $policy );
#
# For compatibility with older Shorewall versions
#
$origdest = ALLIP if $origdest eq 'all';
#
# Take care of chain
#
unless ( $actiontype & NATONLY ) {
#
# Check for illegal bridge port rule
#
if ( $destref->{type} eq 'bport' ) {
unless ( $sourceref->{bridge} eq $destref->{bridge} || single_interface( $sourcezone ) eq $destref->{bridge} ) {
return 1 if $wildcard;
fatal_error "Rules with a DESTINATION Bridge Port zone must have a SOURCE zone on the same bridge";
}
}
$chain = "${sourcezone}2${destzone}";
$chainref = ensure_chain 'filter', $chain;
$policy = $chainref->{policy};
if ( $policy eq 'NONE' ) {
return 1 if $wildcard;
fatal_error "Rules may not override a NONE policy";
}
#
# Handle Optimization
#
if ( $optimize > 0 ) {
my $loglevel = $filter_table->{$chainref->{policychain}}{loglevel};
if ( $loglevel ne '' ) {
return 1 if $target eq "${policy}:$loglevel}";
} else {
return 1 if $basictarget eq $policy;
}
}
#
# Mark the chain as referenced and add appropriate rules from earlier sections.
#
$chainref = ensure_filter_chain $chain, 1;
}
#
# Generate Fixed part of the rule
#
$rule = join( '', do_proto($proto, $ports, $sports), do_ratelimit( $ratelimit, $basictarget ) , do_user( $user ) , do_test( $mark , 0xFF ) , do_connlimit( $connlimit ), do_time( $time ) );
unless ( $section eq 'NEW' ) {
fatal_error "Entries in the $section SECTION of the rules file not permitted with FASTACCEPT=Yes" if $config{FASTACCEPT};
fatal_error "$basictarget rules are not allowed in the $section SECTION" if $actiontype & ( NATRULE | NONAT );
$rule .= "-m state --state $section "
}
#
# Generate NAT rule(s), if any
#
if ( $actiontype & NATRULE ) {
my ( $server, $serverport );
my $randomize = $dest =~ s/:random$// ? '--random ' : '';
require_capability( 'NAT_ENABLED' , "$basictarget rules", '' );
#
# Isolate server port
#
if ( $dest =~ /^(.*)(:(.+))$/ ) {
#
# Server IP and Port
#
$server = $1; # May be empty
$serverport = $3; # Not Empty due to RE
$origdstports = $ports;
if ( $serverport =~ /^(\d+)-(\d+)$/ ) {
#
# Server Port Range
#
fatal_error "Invalid port range ($serverport)" unless $1 < $2;
my @ports = ( $1, $2 );
$_ = validate_port( proto_name( $proto ), $_) for ( @ports );
( $ports = $serverport ) =~ tr/-/:/;
} else {
$serverport = $ports = validate_port( proto_name( $proto ), $serverport );
}
} elsif ( $dest eq ':' ) {
#
# Rule with no server IP or port ( zone:: )
#
$server = $serverport = '';
} else {
#
# Simple server IP address (may be empty or "-")
#
$server = $dest;
$serverport = '';
}
#
# Generate the target
#
my $target = '';
if ( $actiontype & REDIRECT ) {
fatal_error "A server IP address may not be specified in a REDIRECT rule" if $server;
$target = '-j REDIRECT ';
$target .= "--to-port $serverport " if $serverport;
if ( $origdest eq '' || $origdest eq '-' ) {
$origdest = ALLIP;
} elsif ( $origdest eq 'detect' ) {
if ( $config{DETECT_DNAT_IPADDRS} && $sourcezone ne firewall_zone ) {
my $interfacesref = $sourceref->{interfaces};
my @interfaces = keys %$interfacesref;
$origdest = @interfaces ? "detect:@interfaces" : ALLIP;
} else {
$origdest = ALLIP;
}
}
} else {
fatal_error "A server must be specified in the DEST column in $action rules" if $server eq '';
if ( $server =~ /^(.+)-(.+)$/ ) {
validate_range( $1, $2 );
} else {
$server = validate_address $server, 1;
}
if ( $action eq 'SAME' ) {
fatal_error 'Port mapping not allowed in SAME rules' if $serverport;
fatal_error 'SAME not allowed with SOURCE=$FW' if $sourcezone eq firewall_zone;
fatal_error "':random' is not supported by the SAME target" if $randomize;
warning_message 'Netfilter support for SAME is being dropped in early 2008';
$target = '-j SAME ';
for my $serv ( split /,/, $server ) {
$target .= "--to $serv ";
}
} elsif ( $action eq 'DNAT' ) {
$target = '-j DNAT ';
$serverport = ":$serverport" if $serverport;
for my $serv ( split /,/, $server ) {
$target .= "--to-destination ${serv}${serverport} ";
}
}
unless ( $origdest && $origdest ne '-' && $origdest ne 'detect' ) {
if ( $config{DETECT_DNAT_IPADDRS} && $sourcezone ne firewall_zone ) {
my $interfacesref = $sourceref->{interfaces};
my @interfaces = keys %$interfacesref;
$origdest = @interfaces ? "detect:@interfaces" : ALLIP;
} else {
$origdest = ALLIP;
}
}
}
$target .= $randomize;
#
# And generate the nat table rule(s)
#
expand_rule ( ensure_chain ('nat' , $sourceref->{type} eq 'firewall' ? 'OUTPUT' : dnat_chain $sourcezone ),
PREROUTE_RESTRICT ,
$rule ,
$source ,
$origdest ,
'' ,
'' ,
$target ,
$loglevel ,
$action ,
$serverport ? do_proto( $proto, '', '' ) : '' );
#
# After NAT:
# - the destination port will be the server port ($ports) -- we did that above
# - the destination IP will be the server IP ($dest)
# - there will be no log level (we log NAT rules in the nat table rather than in the filter table).
# - the target will be ACCEPT.
#
unless ( $actiontype & NATONLY ) {
$rule = join( '', do_proto( $proto, $ports, $sports ), do_ratelimit( $ratelimit, 'ACCEPT' ), do_user $user , do_test( $mark , 0xFF ) );
$loglevel = '';
$dest = $server;
$action = 'ACCEPT';
}
} elsif ( $actiontype & NONAT ) {
#
# NONAT or ACCEPT+ -- May not specify a destination interface
#
fatal_error "Invalid DEST ($dest) in $action rule" if $dest =~ /:/;
$origdest = '' unless $origdest and $origdest ne '-';
if ( $origdest eq 'detect' ) {
my $interfacesref = $sourceref->{interfaces};
my $interfaces = "@$interfacesref";
$origdest = $interfaces ? "detect:$interfaces" : ALLIP;
}
expand_rule( ensure_chain ('nat' , $sourceref->{type} eq 'firewall' ? 'OUTPUT' : dnat_chain $sourcezone) ,
PREROUTE_RESTRICT ,
$rule ,
$source ,
$dest ,
$origdest ,
'',
'-j RETURN ' ,
$loglevel ,
$action ,
'' );
}
#
# Add filter table rule, unless this is a NATONLY rule type
#
unless ( $actiontype & NATONLY ) {
if ( $actiontype & ACTION ) {
$action = (find_logactionchain $target)->{name};
$loglevel = '';
}
unless ( $origdest eq '-' ) {
require_capability( 'CONNTRACK_MATCH', 'ORIGINAL DEST in a non-NAT rule', 's' ) unless $actiontype & NATRULE;
} else {
$origdest = '';
}
expand_rule( ensure_chain( 'filter', $chain ) ,
$restriction ,
$rule ,
$source ,
$dest ,
$origdest ,
$origdstports ,
"-j $action " ,
$loglevel ,
$action ,
'' );
}
}
#
# Process a Record in the rules file
#
# Deals with the ugliness of wildcard zones ('all' in SOURCE and/or DEST column).
#
sub process_rule ( $$$$$$$$$$$$ ) {
my ( $target, $source, $dest, $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit , $time ) = @_;
my $intrazone = 0;
my $includesrcfw = 1;
my $includedstfw = 1;
my $thisline = $currentline;
#
# Section Names are optional so once we get to an actual rule, we need to be sure that
# we close off any missing sections.
#
unless ( $sectioned ) {
finish_section 'ESTABLISHED,RELATED';
$sections{$section = 'NEW'} = 1;
$sectioned = 1;
}
#
# Handle Wildcards
#
if ( $source =~ /^all[-+]/ ) {
if ( $source eq 'all+' ) {
$source = 'all';
$intrazone = 1;
} elsif ( ( $source eq 'all+-' ) || ( $source eq 'all-+' ) ) {
$source = 'all';
$intrazone = 1;
$includesrcfw = 0;
} elsif ( $source eq 'all-' ) {
$source = 'all';
$includesrcfw = 0;
} else {
fatal_error "Invalid SOURCE ($source)";
}
}
if ( $dest =~ /^all[-+]/ ) {
if ( $dest eq 'all+' ) {
$dest = 'all';
$intrazone = 1;
} elsif ( ( $dest eq 'all+-' ) || ( $dest eq 'all-+' ) ) {
$dest = 'all';
$intrazone = 1;
$includedstfw = 0;
} elsif ( $dest eq 'all-' ) {
$dest = 'all';
$includedstfw = 0;
} else {
fatal_error "Invalid DEST ($dest)";
}
}
my $action = isolate_basic_target $target;
fatal_error "Invalid or missing ACTION ($target)" unless defined $action;
if ( $source eq 'all' ) {
for my $zone ( all_zones ) {
if ( $includesrcfw || ( zone_type( $zone ) ne 'firewall' ) ) {
if ( $dest eq 'all' ) {
for my $zone1 ( all_zones ) {
if ( $includedstfw || ( zone_type( $zone1 ) ne 'firewall' ) ) {
if ( $intrazone || ( $zone ne $zone1 ) ) {
process_rule1 $target, $zone, $zone1 , $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit, $time, 1;
}
}
}
} else {
my $destzone = (split( /:/, $dest, 2 ) )[0];
$destzone = firewall_zone unless defined_zone( $destzone ); # We do this to allow 'REDIRECT all ...'; process_rule1 will catch the case where the dest zone is invalid
if ( $intrazone || ( $zone ne $destzone ) ) {
process_rule1 $target, $zone, $dest , $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit, $time, 1;
}
}
}
}
} elsif ( $dest eq 'all' ) {
for my $zone ( all_zones ) {
my $sourcezone = ( split( /:/, $source, 2 ) )[0];
if ( ( $includedstfw || ( zone_type( $zone ) ne 'firewall') ) && ( ( $sourcezone ne $zone ) || $intrazone) ) {
process_rule1 $target, $source, $zone , $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit, $time, 1;
}
}
} else {
process_rule1 $target, $source, $dest, $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit, $time, 0;
}
progress_message " Rule \"$thisline\" $done";
}
#
# Process the Rules File
#
sub process_rules() {
my $fn = open_file 'rules';
first_entry "$doing $fn...";
while ( read_a_line ) {
my ( $target, $source, $dest, $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit, $time ) = split_line1 1, 12, 'rules file', \%rules_commands;
if ( $target eq 'COMMENT' ) {
process_comment;
} elsif ( $target eq 'SECTION' ) {
#
# read_a_line has already verified that there are exactly two tokens on the line
#
fatal_error "Invalid SECTION ($source)" unless defined $sections{$source};
fatal_error "Duplicate or out of order SECTION $source" if $sections{$source};
$sectioned = 1;
$sections{$source} = 1;
if ( $source eq 'RELATED' ) {
$sections{ESTABLISHED} = 1;
finish_section 'ESTABLISHED';
} elsif ( $source eq 'NEW' ) {
@sections{'ESTABLISHED','RELATED'} = ( 1, 1 );
finish_section ( ( $section eq 'RELATED' ) ? 'RELATED' : 'ESTABLISHED,RELATED' );
}
$section = $source;
} else {
if ( "\L$source" =~ /^none(:.*)?$/ || "\L$dest" =~ /^none(:.*)?$/ ) {
progress_message "Rule \"$currentline\" ignored."
} else {
process_rule $target, $source, $dest, $proto, $ports, $sports, $origdest, $ratelimit, $user, $mark, $connlimit, $time;
}
}
}
clear_comment;
$section = 'DONE';
}
#
# Add jumps from the builtin chains to the interface-chains that are used by this configuration
#
sub add_interface_jumps {
#
# Add Nat jumps
#
for my $interface ( @_ ) {
addnatjump 'POSTROUTING' , snat_chain( $interface ), match_dest_dev( $interface );
}
addnatjump 'PREROUTING' , 'nat_in' , '';
addnatjump 'POSTROUTING' , 'nat_out' , '';
addnatjump 'PREROUTING', 'dnat', '';
for my $interface ( @_ ) {
addnatjump 'PREROUTING' , input_chain( $interface ) , match_source_dev( $interface );
addnatjump 'POSTROUTING' , output_chain( $interface ) , match_dest_dev( $interface );
addnatjump 'POSTROUTING' , masq_chain( $interface ) , match_dest_dev( $interface );
}
#
# Add the jumps to the interface chains from filter FORWARD, INPUT, OUTPUT
#
for my $interface ( @_ ) {
add_jump( $filter_table->{FORWARD} , forward_chain $interface , 0, match_source_dev( $interface ) ) if use_forward_chain $interface;
add_jump( $filter_table->{INPUT} , input_chain $interface , 0, match_source_dev( $interface ) ) if use_input_chain $interface;
if ( use_output_chain $interface ) {
add_jump $filter_table->{OUTPUT} , output_chain $interface , 0, match_dest_dev( $interface ) unless get_interface_option( $interface, 'port' );
}
}
#
# Loopback
#
my $fw = firewall_zone;
my $chainref = $filter_table->{"${fw}2${fw}"};
add_rule $filter_table->{OUTPUT} , "-o lo -j " . ($chainref->{referenced} ? "$chainref->{name}" : 'ACCEPT' );
add_rule $filter_table->{INPUT} , '-i lo -j ACCEPT';
}
# Generate the rules matrix.
#
# Stealing a comment from the Burroughs B6700 MCP Operating System source, generate_matrix makes a sow's ear out of a silk purse.
#
# The biggest disadvantage of the zone-policy-rule model used by Shorewall is that it doesn't scale well as the number of zones increases (Order N**2 where N = number of zones).
# A major goal of the rewrite of the compiler in Perl was to restrict those scaling effects to this function and the rules that it generates.
#
# The function traverses the full "source-zone by destination-zone" matrix and generates the rules necessary to direct traffic through the right set of filter-table rules.
#
sub generate_matrix() {
#
# Helper functions for generate_matrix()
#-----------------------------------------
#
# Return the target for rules from $zone to $zone1.
#
sub rules_target( $$ ) {
my ( $zone, $zone1 ) = @_;
my $chain = "${zone}2${zone1}";
my $chainref = $filter_table->{$chain};
return $chain if $chainref && $chainref->{referenced};
return 'ACCEPT' if $zone eq $zone1;
fatal_error "Internal Error in rules_target()" unless $chainref;
if ( $chainref->{policy} ne 'CONTINUE' ) {
my $policyref = $filter_table->{$chainref->{policychain}};
return $policyref->{name} if $policyref;
fatal_error "No policy defined for zone $zone to zone $zone1";
}
'';
}
#
# Insert the passed exclusions at the front of the passed chain.
#
sub insert_exclusions( $$ ) {
my ( $chainref, $exclusionsref ) = @_;
my $num = 1;
for my $host ( @{$exclusionsref} ) {
my ( $interface, $net ) = split /:/, $host;
insert_rule $chainref , $num++, join( '', match_dest_dev $interface , match_dest_net( $net ), '-j RETURN' );
}
}
#
# Add the passed exclusions at the end of the passed chain.
#
sub add_exclusions ( $$ ) {
my ( $chainref, $exclusionsref ) = @_;
for my $host ( @{$exclusionsref} ) {
my ( $interface, $net ) = split /:/, $host;
add_rule $chainref , join( '', match_dest_dev $interface, match_dest_net( $net ), '-j RETURN' );
}
}
#
# Set a breakpoint in this function if you want to step through generate_matrix().
#
sub start_matrix() {
progress_message2 'Generating Rule Matrix...';
}
#
# G e n e r a t e _ M a t r i x ( ) S t a r t s H e r e
#
start_matrix;
my $exclusion_seq = 1;
my %chain_exclusions;
my %policy_exclusions;
my @interfaces = ( all_interfaces );
my $preroutingref = ensure_chain 'nat', 'dnat';
my $fw = firewall_zone;
my @zones = non_firewall_zones;
my $interface_jumps_added = 0;
#
# Special processing for complex configurations
#
for my $zone ( @zones ) {
my $zoneref = find_zone( $zone );
next if @zones <= 2 && ! $zoneref->{options}{complex};
my $exclusions = $zoneref->{exclusions};
my $frwd_ref = new_standard_chain zone_forward_chain( $zone );
if ( @$exclusions ) {
my $in_ref = new_standard_chain zone_input_chain $zone;
my $out_ref = new_standard_chain zone_output_chain $zone;
add_rule ensure_filter_chain( "${zone}2${zone}", 1 ) , '-j ACCEPT' if rules_target( $zone, $zone ) eq 'ACCEPT';
for my $host ( @$exclusions ) {
my ( $interface, $net ) = split /:/, $host;
my $rule = match_source_dev( $interface ) . match_source_net( $net ) . '-j RETURN';
add_rule $frwd_ref , $rule;
add_rule $in_ref , $rule;
add_rule $out_ref , match_dest_dev( $interface ) . match_dest_net( $net ) . '-j RETURN';
}
}
if ( $capabilities{POLICY_MATCH} ) {
my $type = $zoneref->{type};
my $source_ref = ( $zoneref->{hosts}{ipsec} ) || {};
for my $interface ( sort { interface_number( $a ) <=> interface_number( $b ) } keys %$source_ref ) {
my $sourcechainref;
my $interfacematch = '';
if ( use_forward_chain( $interface ) ) {
$sourcechainref = $filter_table->{forward_chain $interface};
} else {
$sourcechainref = $filter_table->{FORWARD};
$interfacematch = match_source_dev $interface;
move_rules( $filter_table->{forward_chain $interface} , $frwd_ref );
}
my $arrayref = $source_ref->{$interface};
for my $hostref ( @{$arrayref} ) {
my $ipsec_match = match_ipsec_in $zone , $hostref;
for my $net ( @{$hostref->{hosts}} ) {
add_jump(
$sourcechainref,
$frwd_ref,
1,
join( '', $interfacematch , match_source_net( $net ), $ipsec_match )
);
}
}
}
}
}
#
# Main source-zone matrix-generation loop
#
for my $zone ( @zones ) {
my $zoneref = find_zone( $zone );
my $source_hosts_ref = $zoneref->{hosts};
my $chain1 = rules_target firewall_zone , $zone;
my $chain2 = rules_target $zone, firewall_zone;
my $chain3 = rules_target $zone, $zone;
my $complex = $zoneref->{options}{complex} || 0;
my $type = $zoneref->{type};
my $exclusions = $zoneref->{exclusions};
my $frwd_ref = $filter_table->{zone_forward_chain $zone};
my $chain = 0;
my $dnatref = ensure_chain 'nat' , dnat_chain( $zone );
my $nested = $zoneref->{options}{nested};
if ( @$exclusions ) {
insert_exclusions $dnatref, $exclusions if $dnatref->{referenced};
}
if ( $nested ) {
#
# This is a sub-zone. We need to determine if
#
# a) A parent zone defines DNAT/REDIRECT rules; and
# b) The current zone has a CONTINUE policy to some other zone.
#
# If a) but not b), then we must avoid sending packets from this
# zone through the DNAT/REDIRECT chain for the parent.
#
my $parenthasnat = 0;
for my $parent ( @{$zoneref->{parents}} ) {
my $ref = $nat_table->{dnat_chain $parent} || {};
$parenthasnat = 1, last if $ref->{referenced};
}
if ( $parenthasnat ) {
for my $zone1 ( all_zones ) {
if ( $filter_table->{"${zone}2${zone1}"}->{policy} eq 'CONTINUE' ) {
#
# This zone has a continue policy to another zone. We must
# send packets from this zone through the parent's DNAT/REDIRECT chain.
#
$nested = 0;
last;
}
}
} else {
#
# No parent has DNAT so there is nothing to worry about. Don't bother to generate needless RETURN rules in the 'dnat' chain.
#
$nested = 0;
}
}
#
# Take care of PREROUTING, INPUT and OUTPUT jumps
#
for my $typeref ( values %$source_hosts_ref ) {
for my $interface ( sort { interface_number( $a ) <=> interface_number( $b ) } keys %$typeref ) {
my $arrayref = $typeref->{$interface};
if ( $interface eq '+' ) {
#
# Insert the interface-specific jumps before this one which is not interface-specific
#
add_interface_jumps(@interfaces) unless $interface_jumps_added++;
}
for my $hostref ( @$arrayref ) {
my $ipsec_in_match = match_ipsec_in $zone , $hostref;
my $ipsec_out_match = match_ipsec_out $zone , $hostref;
for my $net ( @{$hostref->{hosts}} ) {
my $dest = match_dest_net $net;
if ( $chain1 ) {
my $nextchain;
my $outputref;
my $interfacematch = '';
if ( use_output_chain $interface ) {
$outputref = $filter_table->{output_chain $interface};
} else {
$outputref = $filter_table->{OUTPUT};
$interfacematch = match_dest_dev $interface;
}
if ( @$exclusions ) {
my $output = zone_output_chain $zone;
add_jump $outputref , $output, 0, join( '', $interfacematch, $dest, $ipsec_out_match );
add_jump $filter_table->{$output} , $chain1, 0;
$nextchain = $output;
} else {
add_jump $outputref , $chain1, 0, join( '', $interfacematch, $dest, $ipsec_out_match );
$nextchain = $chain1;
}
add_jump( $outputref , $nextchain, 0, join('', $interfacematch, '-d 255.255.255.255 ' , $ipsec_out_match ) )
if $hostref->{options}{broadcast};
move_rules( $filter_table->{output_chain $interface} , $filter_table->{$nextchain} ) unless use_output_chain $interface;
}
clearrule;
next if $hostref->{options}{destonly};
my $source = match_source_net $net;
if ( $dnatref->{referenced} ) {
#
# There are DNAT/REDIRECT rules with this zone as the source.
# Add a jump from this source network to this zone's DNAT/REDIRECT chain
#
add_jump $preroutingref, $dnatref, 0, join( '', match_source_dev( $interface), $source, $ipsec_in_match );
}
#
# If this zone has parents with DNAT/REDIRECT rules and there are no CONTINUE polcies with this zone as the source
# then add a RETURN jump for this source network.
#
add_rule $preroutingref, join( '', match_source_dev( $interface), $source, $ipsec_in_match, '-j RETURN' ) if $nested;
my $inputchainref;
my $interfacematch = '';
if ( use_input_chain $interface ) {
$inputchainref = $filter_table->{input_chain $interface};
} else {
$inputchainref = $filter_table->{INPUT};
$interfacematch = match_source_dev $interface;
}
if ( $chain2 ) {
my $nextchain;
if ( @$exclusions ) {
my $input = zone_input_chain $zone;
add_jump $inputchainref, $input, 0, join( '', $interfacematch, $source, $ipsec_in_match );
add_jump $filter_table->{ $input } , $chain2, 0;
$nextchain = $input;
} else {
add_jump $inputchainref, $chain2, 0, join( '', $interfacematch, $source, $ipsec_in_match );
$nextchain = $chain2;
}
move_rules( $filter_table->{input_chain $interface} , $filter_table->{$nextchain} ) unless use_input_chain $interface;
}
if ( $frwd_ref && $hostref->{ipsec} ne 'ipsec' ) {
if ( use_forward_chain $interface ) {
add_jump $filter_table->{forward_chain $interface} , $frwd_ref, 0, join( '', $source, $ipsec_in_match );
} else {
add_jump $filter_table->{FORWARD} , $frwd_ref, 0, join( '', match_source_dev( $interface ) , $source, $ipsec_in_match );
move_rules ( $filter_table->{forward_chain $interface} , $frwd_ref );
}
}
}
}
}
}
#
# F O R W A R D I N G
#
my @dest_zones;
my $last_chain = '';
if ( $config{OPTIMIZE} > 0 ) {
my @temp_zones;
ZONE1:
for my $zone1 ( @zones ) {
my $zone1ref = find_zone( $zone1 );
my $policy = $filter_table->{"${zone}2${zone1}"}->{policy};
next if $policy eq 'NONE';
my $chain = rules_target $zone, $zone1;
next unless $chain;
if ( $zone eq $zone1 ) {
next if ( scalar ( keys( %{ $zoneref->{interfaces}} ) ) < 2 ) && ! ( $zoneref->{options}{in_out}{routeback} || @$exclusions );
}
if ( $zone1ref->{type} eq 'bport' ) {
next unless $zoneref->{bridge} eq $zone1ref->{bridge};
}
if ( $chain =~ /2all$/ ) {
if ( $chain ne $last_chain ) {
$last_chain = $chain;
push @dest_zones, @temp_zones;
@temp_zones = ( $zone1 );
} elsif ( $policy eq 'ACCEPT' ) {
push @temp_zones , $zone1;
} else {
$last_chain = $chain;
@temp_zones = ( $zone1 );
}
} else {
push @dest_zones, @temp_zones, $zone1;
@temp_zones = ();
$last_chain = '';
}
}
if ( $last_chain && @temp_zones == 1 ) {
push @dest_zones, @temp_zones;
$last_chain = '';
}
} else {
@dest_zones = @zones ;
}
#
# Here it is -- THE BIG UGLY!!!!!!!!!!!!
#
# We now loop through the destination zones creating jumps to the rules chain for each source/dest combination.
# @dest_zones is the list of destination zones that we need to handle from this source zone
#
ZONE1:
for my $zone1 ( @dest_zones ) {
my $zone1ref = find_zone( $zone1 );
my $policy = $filter_table->{"${zone}2${zone1}"}->{policy};
next if $policy eq 'NONE';
my $chain = rules_target $zone, $zone1;
next unless $chain; # CONTINUE policy with no rules
my $num_ifaces = 0;
if ( $zone eq $zone1 ) {
next ZONE1 if ( $num_ifaces = scalar( keys ( %{$zoneref->{interfaces}} ) ) ) < 2 && ! ( $zoneref->{options}{in_out}{routeback} || @$exclusions );
}
if ( $zone1ref->{type} eq 'bport' ) {
next ZONE1 unless $zoneref->{bridge} eq $zone1ref->{bridge};
}
my $chainref = $filter_table->{$chain};
my $exclusions1 = $zone1ref->{exclusions};
my $dest_hosts_ref = $zone1ref->{hosts};
if ( @$exclusions1 ) {
if ( $chain eq "all2$zone1" ) {
unless ( $chain_exclusions{$chain} ) {
$chain_exclusions{$chain} = 1;
insert_exclusions $chainref , $exclusions1;
}
} elsif ( $chain =~ /2all$/ ) {
my $chain1 = $policy_exclusions{"${chain}_${zone1}"};
unless ( $chain1 ) {
$chain1 = newexclusionchain;
$policy_exclusions{"${chain}_${zone1}"} = $chain1;
my $chain1ref = ensure_filter_chain $chain1, 0;
add_exclusions $chain1ref, $exclusions1;
add_jump $chain1ref, $chain, 0;
}
$chain = $chain1;
} else {
fatal_error "Fatal Error in generate_matrix()" if $chain eq 'ACCEPT';
insert_exclusions $chainref , $exclusions1;
}
}
if ( $frwd_ref ) {
for my $typeref ( values %$dest_hosts_ref ) {
for my $interface ( sort { interface_number( $a ) <=> interface_number( $b ) } keys %$typeref ) {
my $arrayref = $typeref->{$interface};
for my $hostref ( @$arrayref ) {
next if $hostref->{options}{sourceonly};
if ( $zone ne $zone1 || $num_ifaces > 1 || $hostref->{options}{routeback} ) {
my $ipsec_out_match = match_ipsec_out $zone1 , $hostref;
for my $net ( @{$hostref->{hosts}} ) {
add_jump $frwd_ref, $chain, 0, join( '', match_dest_dev( $interface) , match_dest_net($net), $ipsec_out_match );
}
}
}
}
}
} else {
for my $typeref ( values %$source_hosts_ref ) {
for my $interface ( keys %$typeref ) {
my $arrayref = $typeref->{$interface};
my $chain3ref;
my $match_source_dev = '';
if ( use_forward_chain $interface ) {
$chain3ref = $filter_table->{forward_chain $interface};
} else {
$chain3ref = $filter_table->{FORWARD};
$match_source_dev = match_source_dev $interface;
}
for my $hostref ( @$arrayref ) {
next if $hostref->{options}{destonly};
for my $net ( @{$hostref->{hosts}} ) {
for my $type1ref ( values %$dest_hosts_ref ) {
for my $interface1 ( keys %$type1ref ) {
my $array1ref = $type1ref->{$interface1};
for my $host1ref ( @$array1ref ) {
next if $host1ref->{options}{sourceonly};
my $ipsec_out_match = match_ipsec_out $zone1 , $host1ref;
for my $net1 ( @{$host1ref->{hosts}} ) {
unless ( $interface eq $interface1 && $net eq $net1 && ! $host1ref->{options}{routeback} ) {
#
# We defer evaluation of the source net match to accomodate systems without $capabilities{KLUDEFREE};
#
add_jump(
$chain3ref ,
$chain ,
0,
join( '',
$match_source_dev,
match_dest_dev($interface1),
match_source_net($net),
match_dest_net($net1),
$ipsec_out_match )
);
}
}
}
}
}
}
}
}
}
}
#
# E N D F O R W A R D I N G
#
# Now add an unconditional jump to the last unique policy-only chain determined above, if any
#
add_jump $frwd_ref , $last_chain, 1 if $last_chain;
}
}
add_interface_jumps @interfaces unless $interface_jumps_added;
my %builtins = ( mangle => [ qw/PREROUTING INPUT FORWARD POSTROUTING/ ] ,
nat=> [ qw/PREROUTING OUTPUT POSTROUTING/ ] ,
filter=> [ qw/INPUT FORWARD OUTPUT/ ] );
complete_standard_chain $filter_table->{INPUT} , 'all' , firewall_zone , 'DROP';
complete_standard_chain $filter_table->{OUTPUT} , firewall_zone , 'all', 'REJECT';
complete_standard_chain $filter_table->{FORWARD} , 'all' , 'all', 'REJECT';
if ( $config{LOGALLNEW} ) {
for my $table qw/mangle nat filter/ {
for my $chain ( @{$builtins{$table}} ) {
log_rule_limit
$config{LOGALLNEW} ,
$chain_table{$table}{$chain} ,
$table ,
$chain ,
'' ,
'' ,
'insert' ,
'-m state --state NEW ';
}
}
}
}
sub setup_mss( ) {
my $clampmss = $config{CLAMPMSS};
my $option;
my $match = '';
my $chainref = $filter_table->{FORWARD};
if ( $clampmss ) {
if ( "\L$clampmss" eq 'yes' ) {
$option = '--clamp-mss-to-pmtu';
} else {
$match = "-m tcpmss --mss $clampmss: " if $capabilities{TCPMSS_MATCH};
$option = "--set-mss $clampmss";
}
$match .= '-m policy --pol none --dir out ' if $capabilities{POLICY_MATCH};
}
my $interfaces = find_interfaces_by_option( 'mss' );
if ( @$interfaces ) {
#
# Since we will need multiple rules, we create a separate chain
#
$chainref = new_chain 'filter', 'settcpmss';
#
# Send all forwarded SYN packets to the 'settcpmss' chain
#
add_rule $filter_table->{FORWARD} , "-p tcp --tcp-flags SYN,RST SYN -j settcpmss";
my $in_match = '';
my $out_match = '';
if ( $capabilities{POLICY_MATCH} ) {
$in_match = '-m policy --pol none --dir in ';
$out_match = '-m policy --pol none --dir out ';
}
for ( @$interfaces ) {
my $mss = get_interface_option( $_, 'mss' );
my $mssmatch = $capabilities{TCPMSS_MATCH} ? "-m tcpmss --mss $mss: " : '';
add_rule $chainref, "-o $_ -p tcp --tcp-flags SYN,RST SYN ${mssmatch}${out_match}-j TCPMSS --set-mss $mss";
add_rule $chainref, "-o $_ -j RETURN" if $clampmss;
add_rule $chainref, "-i $_ -p tcp --tcp-flags SYN,RST SYN ${mssmatch}${in_match}-j TCPMSS --set-mss $mss";
add_rule $chainref, "-i $_ -j RETURN" if $clampmss;
}
}
add_rule $chainref , "-p tcp --tcp-flags SYN,RST SYN ${match}-j TCPMSS $option" if $clampmss;
}
1;