shorewall_code/Shorewall-perl/Shorewall/Interfaces.pm
2007-05-11 15:39:11 +00:00

358 lines
10 KiB
Perl

#
# Shorewall-perl 3.9 -- /usr/share/shorewall-perl/Shorewall/Interfaces.pm
#
# This program is under GPL [http://www.gnu.org/copyleft/gpl.htm]
#
# (c) 2007 - 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., 675 Mass Ave, Cambridge, MA 02139, USA
#
# This Module contains the code for processing the /etc/shorewall/interfaces
# file. It also exports 'add_group_to_zone()' which other modules call to
# alter zone membership.
#
package Shorewall::Interfaces;
require Exporter;
use Shorewall::Common;
use Shorewall::Config;
use Shorewall::IPAddrs;
use Shorewall::Zones;
use strict;
our @ISA = qw(Exporter);
our @EXPORT = qw( add_group_to_zone
validate_interfaces_file
known_interface
interface_is_optional
find_interfaces_by_option
get_interface_option
@interfaces );
our @EXPORT_OK = ();
our @VERSION = 1.00;
#
# Interface Table.
#
# @interfaces lists the interface names in the order that they appear in the interfaces file.
#
# %interfaces { <interface1> => { root => <name without trailing '+'>
# options => { <option1> = <val1> ,
# ...
# }
# zone => <zone name>
# }
# }
#
our @interfaces;
our %interfaces;
sub add_group_to_zone($$$$$)
{
my ($zone, $type, $interface, $networks, $options) = @_;
my $typeref;
my $interfaceref;
my $arrayref;
my $zoneref = $zones{$zone};
my $zonetype = $zoneref->{type};
my $ifacezone = $interfaces{$interface}{zone};
$zoneref->{interfaces}{$interface} = 1;
my @newnetworks;
my @exclusions;
my $new = \@newnetworks;
my $switched = 0;
$ifacezone = '' unless defined $ifacezone;
for my $host ( @$networks ) {
fatal_error "Invalid Host List" unless defined $host and $host ne '';
if ( substr( $host, 0, 1 ) eq '!' ) {
fatal_error "Only one exclusion allowed in a host list" if $switched;
$switched = 1;
$host = substr( $host, 1 );
$new = \@exclusions;
}
unless ( $switched ) {
if ( $type eq $zonetype ) {
fatal_error "Duplicate Host Group ($interface:$host) in zone $zone" if $ifacezone eq $zone;
$ifacezone = $zone if $host eq ALLIPv4;
}
}
push @$new, $switched ? "$interface:$host" : $host;
}
$zoneref->{options}{in_out}{routeback} = 1 if $options->{routeback};
$typeref = ( $zoneref->{hosts} || ( $zoneref->{hosts} = {} ) );
$interfaceref = ( $typeref->{$type} || ( $interfaceref = $typeref->{$type} = {} ) );
$arrayref = ( $interfaceref->{$interface} || ( $interfaceref->{$interface} = [] ) );
$zoneref->{options}{complex} = 1 if @$arrayref || ( @newnetworks > 1 ) || ( @exclusions );
my %h;
$h{options} = $options;
$h{hosts} = \@newnetworks;
$h{ipsec} = $type eq 'ipsec' ? 'ipsec' : 'none';
push @{$zoneref->{exclusions}}, @exclusions;
push @{$arrayref}, \%h;
}
#
# Return a list of networks routed out of the passed interface
#
sub get_routed_networks ( $$ ) {
my ( $interface , $error_message ) = @_;
my @networks;
if ( open IP , '-|' , "/sbin/ip route show dev $interface 2> /dev/null" ) {
while ( my $route = <IP> ) {
$route =~ s/^\s+//;
my $network = ( split /\s+/, $route )[0];
if ( $network eq 'default' ) {
fatal_error $error_message if $error_message;
warning_message "default route ignored on interface $interface";
} else {
my ( $address, $vlsm ) = split '/', $network;
$vlsm = 32 unless defined $vlsm;
push @networks, "$address/$vlsm";
}
}
close IP
}
@networks;
}
#
# Parse the interfaces file.
#
sub validate_interfaces_file()
{
use constant { SIMPLE_IF_OPTION => 1,
BINARY_IF_OPTION => 2,
ENUM_IF_OPTION => 3,
MASK_IF_OPTION => 3,
IF_OPTION_ZONEONLY => 4 };
my %validoptions = (arp_filter => BINARY_IF_OPTION,
arp_ignore => ENUM_IF_OPTION,
blacklist => SIMPLE_IF_OPTION,
detectnets => SIMPLE_IF_OPTION,
dhcp => SIMPLE_IF_OPTION,
maclist => SIMPLE_IF_OPTION,
logmartians => BINARY_IF_OPTION,
norfc1918 => SIMPLE_IF_OPTION,
nosmurfs => SIMPLE_IF_OPTION,
optional => SIMPLE_IF_OPTION,
proxyarp => BINARY_IF_OPTION,
routeback => SIMPLE_IF_OPTION + IF_OPTION_ZONEONLY,
routefilter => BINARY_IF_OPTION,
sourceroute => BINARY_IF_OPTION,
tcpflags => SIMPLE_IF_OPTION,
upnp => SIMPLE_IF_OPTION,
);
my $fn = open_file 'interfaces';
my $first_entry = 1;
while ( read_a_line ) {
if ( $first_entry ) {
progress_message2 "$doing $fn...";
$first_entry = 0;
}
my ($zone, $interface, $networks, $options ) = split_line 2, 4, 'interfaces file';
my $zoneref;
if ( $zone eq '-' ) {
$zone = '';
} else {
$zoneref = $zones{$zone};
fatal_error "Unknown zone ($zone)" unless $zoneref;
fatal_error "Firewall zone not allowed in ZONE column of interface record" if $zoneref->{type} eq 'firewall';
}
$networks = '' if $networks eq '-';
$options = '' if $options eq '-';
fatal_error "Duplicate Interface ($interface)" if $interfaces{$interface};
fatal_error "Invalid Interface Name: $interface" if $interface =~ /:|^\+$/;
my $wildcard = 0;
if ( $interface =~ /\+$/ ) {
$wildcard = 1;
$interfaces{$interface}{root} = substr( $interface, 0, -1 );
} else {
$interfaces{$interface}{root} = $interface;
}
unless ( $networks eq '' || $networks eq 'detect' ) {
for my $address ( split /,/, $networks ) {
fatal_error 'Invalid BROADCAST address' unless $address =~ /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/;
}
warning_message 'Shorewall no longer uses broadcast addresses in rule generation';
}
my $optionsref = {};
my %options;
if ( $options ) {
for my $option (split ',', $options ) {
next if $option eq '-';
( $option, my $value ) = split /=/, $option;
fatal_error "Invalid Interface option ($option)" unless my $type = $validoptions{$option};
fatal_error "The \"$option\" option may not be specified on a multi-zone interface" if $type & IF_OPTION_ZONEONLY && ! $zone;
$type &= MASK_IF_OPTION;
if ( $type == SIMPLE_IF_OPTION ) {
fatal_error "Option $option does not take a value" if defined $value;
$options{$option} = 1;
} elsif ( $type == BINARY_IF_OPTION ) {
$value = 1 unless defined $value;
fatal_error "Option value for $option must be 0 or 1" unless ( $value eq '0' || $value eq '1' );
fatal_error "The $option option may not be used with a wild-card interface name" if $wildcard;
$options{$option} = $value;
} elsif ( $type == ENUM_IF_OPTION ) {
fatal_error "The $option option may not be used with a wild-card interface name" if $wildcard;
if ( $option eq 'arp_ignore' ) {
if ( defined $value ) {
if ( $value =~ /^[1-3,8]$/ ) {
$options{arp_ignore} = $value;
} else {
fatal_error "Invalid value ($value) for arp_ignore";
}
} else {
$options{arp_ignore} = 1;
}
} else {
fatal_error "Internal Error in validate_interfaces_file";
}
}
}
$zoneref->{options}{in_out}{routeback} = 1 if $options{routeback};
}
$interfaces{$interface}{options} = $optionsref = \%options;
push @interfaces, $interface;
my @networks;
if ( $options{detectnets} ) {
fatal_error "'detectnets' not allowed with multi-zone interface" unless $zone;
fatal_error "The 'detectnets' option may not be used with a wild-card interface name" if $wildcard;
@networks = get_routed_networks( $interface, 'detectnets not allowed on interface with default route' );
fatal_error "No routes through 'detectnets' interface $interface" unless @networks || $options{optional};
} else {
@networks = @allipv4;
}
add_group_to_zone( $zone, $zoneref->{type}, $interface, \@networks, $optionsref ) if $zone && @networks;
$interfaces{$interface}{zone} = $zone; #Must follow the call to add_group_to_zone()
progress_message " Interface \"$line\" Validated";
}
}
#
# Returns true if passed interface matches an entry in /etc/shorewall/interfaces
#
# If the passed name matches a wildcard, a entry for the name is added in %interfaces to speed up validation of other references to that name.
#
sub known_interface($)
{
my $interface = $_[0];
return 1 if exists $interfaces{$interface};
for my $i ( @interfaces ) {
my $val = $interfaces{$i}{root};
next if $val eq $i;
my $len = length $val;
if ( substr( $interface, 0, $len ) eq $val ) {
#
# Cache this result for future reference
#
$interfaces{$interface} = undef;
return 1;
}
}
0;
}
#
# Return the 'optional' setting of the passed interface
#
sub interface_is_optional($) {
my $optionsref = $interfaces{$_[0]}{options};
$optionsref && $optionsref->{optional};
}
#
# Returns reference to array of interfaces with the passed option
#
sub find_interfaces_by_option( $ ) {
my $option = $_[0];
my @ints = ();
for my $interface ( @interfaces ) {
my $optionsref = $interfaces{$interface}{options};
if ( $optionsref && defined $optionsref->{$option} ) {
push @ints , $interface
}
}
\@ints;
}
#
# Return the value of an option for an interface
#
sub get_interface_option( $$ ) {
my ( $interface, $option ) = @_;
$interfaces{$interface}{options}{$option};
}
1;