Support IPv6 Masquerade

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

Shorewall-core/lib.cli

@@ -25,7 +25,7 @@
 # loaded after this one and replaces some of the functions declared here.
 #
 
-SHOREWALL_CAPVERSION=40512
+SHOREWALL_CAPVERSION=40514
 
 [ -n "${g_program:=shorewall}" ]
 
@@ -2197,6 +2197,7 @@ determine_capabilities() {
     NFACCT_MATCH=
     CHECKSUM_TARGET=
     ARPTABLESJF=
+    MASQUERADE_TGT=
     AMANDA_HELPER=
     FTP_HELPER=
     FTP0_HELPER=
@@ -2228,6 +2229,7 @@ determine_capabilities() {
 	    else
 		qt $g_tool -t nat -A $chain -j SNAT --to-source 2001::1 --persistent && PERSISTENT_SNAT=Yes
 	    fi
+	    qt $g_tool -t nat -A $chain -j MASQUERADE && MASQUERADE_TGT=Yes
 	    qt $g_tool -t nat -F $chain
 	    qt $g_tool -t nat -X $chain
 	fi
@@ -2602,6 +2604,7 @@ report_capabilities_unsorted() {
     report_capability "NFAcct match" $NFACCT_MATCH
     report_capability "Checksum Target" $CHECKSUM_TARGET
     report_capability "Arptables JF" $ARPTABLESJF
+    report_capability "MASQUERADE Target" $MASQUERADE_TGT
 
     report_capability "Amanda Helper" $AMANDA_HELPER
     report_capability "FTP Helper" $FTP_HELPER
@@ -2720,6 +2723,7 @@ report_capabilities_unsorted1() {
     report_capability1 NFACCT_MATCH
     report_capability1 CHECKSUM_TARGET
     report_capability1 ARPTABLESJF
+    report_capability1 MASQUERADE_TGT
 
     report_capability1 AMANDA_HELPER
     report_capability1 FTP_HELPER

Shorewall/Perl/Shorewall/Config.pm

@@ -357,6 +357,7 @@ our %capdesc = ( NAT_ENABLED     => 'NAT',
 		 NFACCT_MATCH    => 'NFAcct Match',
 		 CHECKSUM_TARGET => 'Checksum Target',
 		 ARPTABLESJF     => 'Arptables JF',
+		 MASQUERADE_TGT  => 'MASQUERADE Target',
 		 AMANDA_HELPER   => 'Amanda Helper',
 		 FTP_HELPER      => 'FTP Helper',
 		 FTP0_HELPER     => 'FTP-0 Helper',
@@ -649,7 +650,7 @@ sub initialize( $;$$) {
 		    KLUDGEFREE              => '',
 		    STATEMATCH              => '-m state --state',
 		    VERSION                 => "4.5.13-Beta3",
-		    CAPVERSION              => 40512 ,
+		    CAPVERSION              => 40514 ,
 		  );
     #
     # From shorewall.conf file
@@ -901,6 +902,7 @@ sub initialize( $;$$) {
 	       NFACCT_MATCH => undef,
 	       CHECKSUM_TARGET => undef,
 	       ARPTABLESJF => undef,
+	       MASQUERADE_TGT => undef,
 
 	       AMANDA_HELPER => undef,
 	       FTP_HELPER => undef,
@@ -3561,6 +3563,22 @@ sub Persistent_Snat() {
     $result;
 }
 
+sub Masquerade_Tgt() {
+    have_capability( 'NAT_ENABLED' ) || return '';
+
+    my $result = '';
+    my $address = $family == F_IPV4 ? '1.2.3.4' : '2001::1';
+
+    if ( qt1( "$iptables -t nat -N $sillyname" ) ) {
+	$result = qt1( "$iptables -t nat -A $sillyname -j MASQUERADE" );
+	qt1( "$iptables -t nat -F $sillyname" );
+	qt1( "$iptables -t nat -X $sillyname" );
+
+    }
+
+    $result;
+}
+
 sub Mangle_Enabled() {
     if ( qt1( "$iptables -t mangle -L -n" ) ) {
 	system( "$iptables -t mangle -N $sillyname" ) == 0 || fatal_error "Cannot Create Mangle chain $sillyname";
@@ -4075,6 +4093,7 @@ our %detect_capability =
       MANGLE_FORWARD => \&Mangle_Forward,
       MARK => \&Mark,
       MARK_ANYWHERE => \&Mark_Anywhere,
+      MASQUERADE_TGT => \&Masquerade_Tgt,
       MULTIPORT => \&Multiport,
       NAT_ENABLED => \&Nat_Enabled,
       NETBIOS_NS_HELPER => \&Netbios_ns_Helper,

Shorewall/Perl/Shorewall/Nat.pm

@@ -172,7 +172,7 @@ sub process_one_masq1( $$$$$$$$$$ )
 	#
 	if ( $addresses ne '-' ) {
 	    if ( $addresses eq 'random' ) {
-		fatal_error 'Invalid IPv6 address (random)' if $family == F_IPV6;
+		require_capability( 'MASQUERADE_TGT', 'Masquerade rules', '') if $family == F_IPV6;
 		$randomize = '--random ';
 	    } else {
 		$addresses =~ s/:persistent$// and $persistent = ' --persistent ';
@@ -194,9 +194,11 @@ sub process_one_masq1( $$$$$$$$$$ )
 			$detectaddress = 1;
 		    }
 		} elsif ( $addresses eq 'NONAT' ) {
+		    fatal_error "'persistent' may not be specified with 'NONAT'" if $persistent;
+		    fatal_error "'random' may not be specified with 'NONAT'"     if $randomize;
 		    $target = 'RETURN';
 		    $add_snat_aliases = 0;
-		} else {
+		} elsif ( $addresses ) {
 		    my $addrlist = '';
 		    my @addrs = split_list $addresses, 'address';
 
@@ -305,13 +307,15 @@ sub process_one_masq1( $$$$$$$$$$ )
 		    }
 
 		    $target .= $addrlist;
+		} else {
+		    require_capability( 'MASQUERADE_TGT', 'Masquerade rules', '' )  if $family == F_IPV6;
 		}
 	    }
 
 	    $target .= $randomize;
 	    $target .= $persistent;
 	} else {
-	    fatal_error "IPv6 does does not support MASQUERADE -- you must use SNAT" if $family == F_IPV6;
+	    require_capability( 'MASQUERADE_TGT', 'Masquerade rules', '' )  if $family == F_IPV6;
 	    $add_snat_aliases = 0;
 	}
 	#
@@ -373,11 +377,9 @@ sub process_one_masq( )
 #
 sub setup_masq()
 {
-    my $name = $family == F_IPV4 ? 'masq' : 'snat';
+    if ( my $fn = open_file( 'masq', 1, 1 ) ) {
 
-    if ( my $fn = open_file( $name, 1, 1 ) ) {
+	first_entry( sub { progress_message2 "$doing $fn..."; require_capability 'NAT_ENABLED' , "a non-empty masq file" , 's'; } );
-
-	first_entry( sub { progress_message2 "$doing $fn..."; require_capability 'NAT_ENABLED' , "a non-empty $name file" , 's'; } );
 
 	process_one_masq while read_a_line( NORMAL_READ );
     }

Shorewall6/configfiles/masq

@@ -1,10 +1,10 @@
 #
-# Shorewall6 version 4 - SNAT file
+# Shorewall6 version 4 - MASQUERADE/SNAT file
 #
-# For information about entries in this file, type "man shorewall6-snat"
+# For information about entries in this file, type "man shorewall6-masq"
 #
 # The manpage is also online at
-# http://www.shorewall.net/manpages6/shorewall6-snat.html
+# http://www.shorewall.net/manpages6/shorewall6-masq.html
 #
 ########################################################################################################################
 #INTERFACE	SOURCE			ADDRESS			PROTO	PORT(S)	IPSEC	MARK	USER/	SWITCH	ORIGINAL

Shorewall6/manpages/shorewall6-masq.xml

@@ -3,20 +3,20 @@
 "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
 <refentry>
   <refmeta>
-    <refentrytitle>shorewall6-snat</refentrytitle>
+    <refentrytitle>shorewall6-masq</refentrytitle>
 
     <manvolnum>5</manvolnum>
   </refmeta>
 
   <refnamediv>
-    <refname>snat</refname>
+    <refname>masq</refname>
 
-    <refpurpose>Shorewall6 SNAT definition file</refpurpose>
+    <refpurpose>Shorewall6 Masquerade/SNAT definition file</refpurpose>
   </refnamediv>
 
   <refsynopsisdiv>
     <cmdsynopsis>
-      <command>/etc/shorewall6/snat</command>
+      <command>/etc/shorewall6/masq</command>
     </cmdsynopsis>
   </refsynopsisdiv>
 
@@ -26,11 +26,6 @@
     <para>Use this file to define Source NAT (SNAT). Requires Shorewall 4.5.14
     or later.</para>
 
-    <note>
-      <para>Unlike with IPv4, Netfilter does not support the MASQUERADE target
-      with IPv6.</para>
-    </note>
-
     <warning>
       <para>The entries in this file are order-sensitive. The first entry that
       matches a particular connection will be the one that is used.</para>
@@ -117,27 +112,32 @@
       </varlistentry>
 
       <varlistentry>
-        <term><emphasis role="bold">ADDRESS</emphasis> -
+        <term><emphasis role="bold">ADDRESS</emphasis> (Optional) - [<emphasis
-        {<emphasis>address-or-address-range</emphasis>[,<emphasis>address-or-address-range</emphasis>]...][:<emphasis>lowport</emphasis><emphasis
+        role="bold">-</emphasis>|<emphasis
+        role="bold">NONAT</emphasis>|[<emphasis>address-or-address-range</emphasis>[,<emphasis>address-or-address-range</emphasis>]...][:<emphasis>lowport</emphasis><emphasis
         role="bold">-</emphasis><emphasis>highport</emphasis>][<emphasis
-        role="bold">:random</emphasis>][:persistent]|}</term>
+        role="bold">:random</emphasis>][:persistent]|<emphasis
+        role="bold">detect</emphasis>|<emphasis
+        role="bold">random</emphasis>]</term>
 
         <listitem>
-          <para>The address specified here will be used as the source address.
+          <para>If you do not specify an address or address range,
-          If you simply wish to use the IPv6 address of the
+          masquerading will be performed. This requires <firstterm>Masquerade
-          <replaceable>interface</replaceable> in the first column, enter the
+          Target</firstterm> support in your kernel and ip6tables.</para>
-          name of that interface preceded by an apersand ('&amp;') - e.g.,
+
-          &amp;sit1.</para>
+          <para>If you specify an address here, SNAT will be used and this
+          will be the source address.</para>
 
           <para>You may also specify a range of up to 256 IP addresses if you
           want the SNAT address to be assigned from that range in a
           round-robin fashion by connection. The range is specified by
           <emphasis>first.ip.in.range</emphasis>-<emphasis>last.ip.in.range</emphasis>.
-          The address or address range may be optionally followed by a port
+          You may follow the port range with<emphasis
-          range. When this is done, you must enclose the IPv6 address(es) in
+          role="bold">:random</emphasis> in which case assignment of ports
-          square brackets. You may follow the port range with<emphasis
+          from the list will be random. <emphasis
-          role="bold"> :random</emphasis> in which case assignment of ports
+          role="bold">random</emphasis> may also be specified by itself in
-          from the range will be random.</para>
+          this column in which case random local port assignments are made for
+          the outgoing connections.</para>
 
           <para>Example:
           [2001:470:a:227::2]-[2001:470:a:227::10]:1000-1010</para>
@@ -148,9 +148,6 @@
           address range is specified and causes a client to be given the same
           source/destination IP pair.</para>
 
-          <para>Finally, you may also specify a comma-separated list of ranges
-          and/or addresses in this column.</para>
-
           <para>This column may not contain DNS Names.</para>
 
           <para>Normally, Netfilter will attempt to retain the source port
@@ -502,7 +499,7 @@
           <para>Your entry in the file will be:</para>
 
           <programlisting>        #INTERFACE   SOURCE                  ADDRESS
-        eth0         2001:470:b:787::0/64    &amp;eth0</programlisting>
+        eth0         2001:470:b:787::0/64    -</programlisting>
         </listitem>
       </varlistentry>
     </variablelist>
@@ -511,6 +508,6 @@
   <refsect1>
     <title>FILES</title>
 
-    <para>/etc/shorewall6/snat</para>
+    <para>/etc/shorewall6/masq</para>
   </refsect1>
 </refentry>