add drop down menu for interfaces

settings.pl

@@ -22,6 +22,61 @@
 #
 #
 
+
+sub html_escape( $ )
+{
+	my $s = $_[0];
+	$s = '' unless defined $s;
+	$s =~ s/&/&/g;
+	$s =~ s/</&lt;/g;
+	$s =~ s/>/&gt;/g;
+	$s =~ s/"/&quot;/g;
+	return $s;
+}
+
+sub network_interface_options( $ )
+{
+	my $current = $_[0];
+	my @interfaces = ();
+	my %seen = ();
+	my $html = '';
+
+	$current = '' unless defined $current;
+
+	if( opendir( my $dh, '/sys/class/net' ) )
+	{
+		foreach my $ifname ( sort readdir( $dh ) )
+		{
+			next if $ifname =~ /^\./;
+			next if $ifname =~ /[^-_\.A-Za-z0-9]/;
+			next if $seen{$ifname};
+			push( @interfaces, $ifname );
+			$seen{$ifname} = 1;
+		}
+		closedir( $dh );
+	}
+
+	# Keep special/manual values usable even if they are not real kernel interfaces.
+	foreach my $ifname ( '*', 'auto', $current )
+	{
+		next if !defined( $ifname ) || $ifname eq '';
+		next if $seen{$ifname};
+		push( @interfaces, $ifname );
+		$seen{$ifname} = 1;
+	}
+
+	foreach my $ifname ( @interfaces )
+	{
+		my $selected = ( $ifname eq $current ) ? ' SELECTED' : '';
+		my $label = $ifname;
+		$label = '* (all interfaces)' if $ifname eq '*';
+		$label = 'auto' if $ifname eq 'auto';
+		$html .= '\t\t\t\t<OPTION VALUE="' . html_escape( $ifname ) . '"' . $selected . '>' . html_escape( $label ) . '</OPTION>\n';
+	}
+
+	return $html;
+}
+
 sub handle_request()
 {
 	if( $c[1] eq 'general' )
@@ -1385,6 +1440,7 @@ EOF
 		{
 			$c = getconfigline( '4 ' . $c[2] );
 			@c = split( ' ', $c );
+			$interface_options = network_interface_options( $c[1] );
 			
 			$c[2] =~ s/\.//g;
 			eval( '$frametype_' . $c[2] . ' = " SELECTED";' );
@@ -1453,7 +1509,10 @@ TT { color:#5b4b38; }
 			<B>Network interface:</B>
 		</TD>
 		<TD ALIGN=RIGHT>
-			<INPUT NAME="interface" TYPE=TEXT SIZE=20 VALUE="$c[1]"><BR>
+			<SELECT NAME="interface">
+$interface_options			</SELECT><BR>
+			<SMALL>Manual override:</SMALL><BR>
+			<INPUT NAME="interface_manual" TYPE=TEXT SIZE=20 VALUE=""><BR>
 		</TD>
 	</TR>
 	<TR BGCOLOR="#fbf7f1">