Add the 'loopback' interface option

Signed-off-by: Tom Eastep <teastep@shorewall.net>

Shorewall/Perl/Shorewall/Config.pm

@@ -412,7 +412,7 @@ our %capdesc = ( NAT_ENABLED     => 'NAT',
 		 SIP0_HELPER     => 'SIP-0 Helper',
 		 SNMP_HELPER     => 'SNMP Helper',
 		 TFTP_HELPER     => 'TFTP Helper',
-		 TFTP0_HELPER     => 'TFTP-0 Helper',
+		 TFTP0_HELPER    => 'TFTP-0 Helper',
 		 #
 		 # Constants
 		 #

Shorewall/Perl/Shorewall/Misc.pm

@@ -854,7 +854,7 @@ sub add_common_rules ( $$ ) {
 
 	my $interfaceref = find_interface $interface;
 
-	unless ( $interfaceref->{physical} eq 'lo' ) {
+	unless ( $interfaceref->{physical} eq loopback_interface ) {
 	    unless ( $interfaceref->{options}{ignore} & NO_SFILTER || $interfaceref->{options}{rpfilter} ) {
 
 		my @filters = @{$interfaceref->{filter}};
@@ -1452,7 +1452,7 @@ sub handle_loopback_traffic() {
     my $rawout   = $raw_table->{OUTPUT};
     my $rulenum  = 0;
     my $loopback = loopback_zones;
-    my $loref    = known_interface('lo');
+    my $loref    = known_interface(loopback_interface);
 
     my $unmanaged;
     my $outchainref;
@@ -1463,17 +1463,17 @@ sub handle_loopback_traffic() {
 	# We have a vserver zone -- route output through a separate chain
 	#
 	$outchainref = new_standard_chain 'loopback';
-	add_ijump $filter_table->{OUTPUT}, j => $outchainref, o => 'lo';
+	add_ijump $filter_table->{OUTPUT}, j => $outchainref, o => loopback_interface;
     } else {
 	#
 	# Only the firewall -- just use the OUTPUT chain
 	#
 	if ( $unmanaged = $loref && $loref->{options}{unmanaged} ) {
-	    add_ijump( $filter_table->{INPUT},  j => 'ACCEPT', i => 'lo' );
+	    add_ijump( $filter_table->{INPUT},  j => 'ACCEPT', i => loopback_interface );
-	    add_ijump( $filter_table->{OUTPUT}, j => 'ACCEPT', o => 'lo' );
+	    add_ijump( $filter_table->{OUTPUT}, j => 'ACCEPT', o => loopback_interface );
 	} else {
 	    $outchainref = $filter_table->{OUTPUT};
-	    @rule = ( o => 'lo');
+	    @rule = ( o => loopback_interface);
 	}
     }
 
@@ -1552,7 +1552,7 @@ sub add_interface_jumps {
     our %forward_jump_added;
     my @interfaces = grep $_ ne '%vserver%', @_;
     my $dummy;
-    my $lo_jump_added = interface_zone( 'lo' ) && ! get_interface_option( 'lo', 'destonly' );
+    my $lo_jump_added = interface_zone( loopback_interface ) && ! get_interface_option( loopback_interface, 'destonly' );
     #
     # Add Nat jumps
     #
@@ -1582,7 +1582,7 @@ sub add_interface_jumps {
 	my $outputref    = $filter_table->{output_chain $interface};
 	my $interfaceref = find_interface($interface);
 
-	add_ijump $filter_table->{INPUT} , j => 'ACCEPT', i => 'lo' if $interfaceref->{physical} eq '+' && ! $lo_jump_added++;
+	add_ijump $filter_table->{INPUT} , j => 'ACCEPT', i => loopback_interface if $interfaceref->{physical} eq '+' && ! $lo_jump_added++;
 
 	if ( $interfaceref->{options}{port} ) {
 	    my $bridge = $interfaceref->{bridge};
@@ -1621,7 +1621,7 @@ sub add_interface_jumps {
 	}
     }
 
-    add_ijump $filter_table->{INPUT} , j => 'ACCEPT', i => 'lo' unless $lo_jump_added++;
+    add_ijump $filter_table->{INPUT} , j => 'ACCEPT', i => loopback_interface unless $lo_jump_added++;
 
     handle_loopback_traffic;
 }
@@ -2551,8 +2551,8 @@ EOF
 
     process_routestopped unless process_stoppedrules;
 
-    add_ijump $input,  j => 'ACCEPT', i => 'lo';
+    add_ijump $input,  j => 'ACCEPT', i => loopback_interface;
-    add_ijump $output, j => 'ACCEPT', o => 'lo' unless $config{ADMINISABSENTMINDED};
+    add_ijump $output, j => 'ACCEPT', o => loopback_interface unless $config{ADMINISABSENTMINDED};
 
     my $interfaces = find_interfaces_by_option 'dhcp';
 

Shorewall/Perl/Shorewall/Zones.pm

@@ -55,6 +55,7 @@ our @EXPORT = ( qw( NOTHING
 		    find_zone
 		    firewall_zone
 		    loopback_zones
+		    loopback_interface
 		    local_zones
 		    defined_zone
 		    zone_type
@@ -219,6 +220,7 @@ our $minroot;
 our $zonemark;
 our $zonemarkincr;
 our $zonemarklimit;
+our $loopback_interface;
 
 use constant { FIREWALL => 1,
 	       IP       => 2,
@@ -329,6 +331,7 @@ sub initialize( $$ ) {
     %mapbase1 = ();
     $baseseq = 0;
     $minroot = 0;
+    $loopback_interface = '';
 
     if ( $family == F_IPV4 ) {
 	%validinterfaceoptions = (arp_filter  => BINARY_IF_OPTION,
@@ -341,6 +344,7 @@ sub initialize( $$ ) {
 				  ignore      => NUMERIC_IF_OPTION + IF_OPTION_WILDOK,
 				  maclist     => SIMPLE_IF_OPTION + IF_OPTION_HOST,
 				  logmartians => BINARY_IF_OPTION,
+				  loopback    => BINARY_IF_OPTION,
 				  nets        => IPLIST_IF_OPTION + IF_OPTION_ZONEONLY + IF_OPTION_VSERVER,
 				  norfc1918   => OBSOLETE_IF_OPTION,
 				  nosmurfs    => SIMPLE_IF_OPTION + IF_OPTION_HOST,
@@ -386,6 +390,7 @@ sub initialize( $$ ) {
 				    destonly    => SIMPLE_IF_OPTION + IF_OPTION_HOST,
 				    dhcp        => SIMPLE_IF_OPTION,
 				    ignore      => NUMERIC_IF_OPTION + IF_OPTION_WILDOK,
+				    loopback    => BINARY_IF_OPTION,
 				    maclist     => SIMPLE_IF_OPTION + IF_OPTION_HOST,
 				    nets        => IPLIST_IF_OPTION + IF_OPTION_ZONEONLY + IF_OPTION_VSERVER,
 				    nosmurfs    => SIMPLE_IF_OPTION + IF_OPTION_HOST,
@@ -1353,8 +1358,15 @@ sub process_interface( $$ ) {
 	$options{ignore} ||= 0;
     }
 
+    $options{loopback} ||= ( $physical eq 'lo' );
+
+    if ( $options{loopback} ) {
+	fatal_error "Only one 'loopback' interface is allowed" if $loopback_interface;
+	$loopback_interface = $physical;
+    }
+
     if ( $options{unmanaged} ) {
-	fatal_error "The 'lo' interface may not be unmanaged when there are vserver zones" if $physical eq 'lo' && vserver_zones;
+	fatal_error "The loopback interface ($loopback_interface) may not be unmanaged when there are vserver zones" if $options{loopback} && vserver_zones;
 
 	while ( my ( $option, $value ) = each( %options ) ) {
 	    fatal_error "The $option option may not be specified with 'unmanaged'" if $prohibitunmanaged{$option};
@@ -1382,9 +1394,9 @@ sub process_interface( $$ ) {
     if ( $zone ) {
 	fatal_error "Unmanaged interfaces may not be associated with a zone" if $options{unmanaged};
 
-	if ( $physical eq 'lo' ) {
+	if ( $options{loopback} ) {
-	    fatal_error "Only a loopback zone may be assigned to 'lo'" unless $zoneref->{type} == LOOPBACK;
+	    fatal_error "Only a loopback zone may be assigned to '$physical'" unless $zoneref->{type} == LOOPBACK;
-	    fatal_error "Invalid definition of 'lo'"                   if $bridge ne $interface;
+	    fatal_error "Invalid definition of '$physical'"                   if $bridge ne $interface;
 	    
 	    for ( qw/arp_filter
 		     arp_ignore
@@ -1406,10 +1418,10 @@ sub process_interface( $$ ) {
 		     upnpclient
 		     mss
 		    / ) {
-		fatal_error "The 'lo' interface may not specify the '$_' option" if supplied $options{$_};
+		fatal_error "The '$config{LOOPBACK}' interface may not specify the '$_' option" if supplied $options{$_};
 	    }
 	} else {
-	    fatal_error "A loopback zone may only be assigned to 'lo'" if $zoneref->{type} == LOOPBACK;
+	    fatal_error "A loopback zone may only be assigned to the loopback interface" if $zoneref->{type} == LOOPBACK;
 	}
 
 	$netsref ||= [ allip ];
@@ -1466,6 +1478,22 @@ sub validate_interfaces_file( $ ) {
     #
     fatal_error "No network interfaces defined" unless @interfaces;
 
+    #
+    # Define the loopback interface if it hasn't been already
+    #
+    unless ( $loopback_interface ) {
+	$interfaces{lo} = { name             => 'lo',
+			    bridge           => 'lo',
+			    nets             => 0,
+			    number           => $nextinum++,
+			    root             => 'lo',
+			    broadcasts       => undef,
+			    options          => { unmanaged => 1, loopback => 1 , ignore => 1 },
+			    zone             => '',
+			    physical         => 'lo' };
+	push @interfaces, $loopback_interface = 'lo';
+    }
+
     if ( vserver_zones ) {
 	#
 	# While the user thinks that vservers are associated with a particular interface, they really are not.
@@ -1481,7 +1509,7 @@ sub validate_interfaces_file( $ ) {
 				    broadcasts => undef ,
 				    options    => {} ,
 				    zone       => '',
-				    physical   => 'lo',
+				    physical   => $loopback_interface,
 				  };
 
 	push @interfaces, $interface;
@@ -1543,6 +1571,13 @@ sub known_interface($)
     $physical{$interface} || 0;
 }
 
+# 
+# Return the loopback interface physical name
+#
+sub loopback_interface() {
+    $loopback_interface;
+}
+
 #
 # Return interface number
 #
@@ -1589,7 +1624,7 @@ sub managed_interfaces() {
 # Return a list of unmanaged interfaces (skip 'lo' since it is implicitly unmanaged when there are no loopback zones).
 #
 sub unmanaged_interfaces() {
-    grep ( $interfaces{$_}{options}{unmanaged} && $_ ne 'lo', @interfaces );
+    grep ( $interfaces{$_}{options}{unmanaged} && ! $interfaces{$_}{options}{loopback}, @interfaces );
 }
 
 #
@@ -1989,10 +2024,10 @@ sub process_host( ) {
 	fatal_error "Unknown interface ($interface)" unless ($interfaceref = $interfaces{$interface}) && $interfaceref->{root};
 	fatal_error "Unmanaged interfaces may not be associated with a zone" if $interfaceref->{unmanaged};
 
-	if ( $interfaceref->{name} eq 'lo' ) {
+	if ( $interfaceref->{physical} eq $loopback_interface ) {
-	    fatal_error "Only a loopback zone may be associated with the loopback interface (lo)" if $type != LOOPBACK;
+	    fatal_error "Only a loopback zone may be associated with the loopback interface ($loopback_interface)" if $type != LOOPBACK;
 	} else {
-	    fatal_error "Loopback zones may only be associated with the loopback interface (lo)" if $type == LOOPBACK;
+	    fatal_error "Loopback zones may only be associated with the loopback interface ($loopback_interface)" if $type == LOOPBACK;
 	}
     } else {
 	fatal_error "Invalid HOST(S) column contents: $hosts"

Shorewall/manpages/shorewall-interfaces.xml

@@ -213,7 +213,7 @@ loc     eth2            -</programlisting>
                 changed; the value assigned to the setting will be the value
                 specified (if any) or 1 if no value is given.</para>
 
-                <para></para>
+                <para/>
 
                 <note>
                   <para>This option does not work with a wild-card
@@ -247,7 +247,7 @@ loc     eth2            -</programlisting>
 
                 <para>8 - do not reply for all local addresses</para>
 
-                <para></para>
+                <para/>
 
                 <note>
                   <para>This option does not work with a wild-card
@@ -255,7 +255,7 @@ loc     eth2            -</programlisting>
                   the INTERFACE column.</para>
                 </note>
 
-                <para></para>
+                <para/>
 
                 <warning>
                   <para>Do not specify <emphasis
@@ -382,6 +382,17 @@ loc     eth2            -</programlisting>
               </listitem>
             </varlistentry>
 
+            <varlistentry>
+              <term>loopback</term>
+
+              <listitem>
+                <para>Added in Shorewall 4.6.6. Designates the interface as
+                the loopback interface. This option is assumed if the
+                interface's physical name is 'lo'. Only one interface man have
+                the <option>loopback</option> option specified.</para>
+              </listitem>
+            </varlistentry>
+
             <varlistentry>
               <term><emphasis
               role="bold">logmartians[={0|1}]</emphasis></term>
@@ -414,7 +425,7 @@ loc     eth2            -</programlisting>
         1
         teastep@lists:~$ </programlisting>
 
-                <para></para>
+                <para/>
 
                 <note>
                   <para>This option does not work with a wild-card

Shorewall6/manpages/shorewall6-interfaces.xml

@@ -323,6 +323,17 @@ loc     eth2            -</programlisting>
               </listitem>
             </varlistentry>
 
+            <varlistentry>
+              <term>loopback</term>
+
+              <listitem>
+                <para>Added in Shorewall 4.6.6. Designates the interface as
+                the loopback interface. This option is assumed if the
+                interface's physical name is 'lo'. Only one interface man have
+                the <option>loopback</option> option specified.</para>
+              </listitem>
+            </varlistentry>
+
             <varlistentry>
               <term><emphasis
               role="bold">mss</emphasis>=<emphasis>number</emphasis></term>