From ec32733dab8bb0b1ae906c01dfe216b787cd7d07 Mon Sep 17 00:00:00 2001
From: Mario Fetka <mario.fetka@gmail.com>
Date: Thu, 21 May 2026 17:11:06 +0200
Subject: [PATCH] add drop down menu for interfaces with IPX active

---
 settings.pl | 108 ++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 97 insertions(+), 11 deletions(-)

diff --git a/settings.pl b/settings.pl
index 6cb83f2..63977a9 100644
--- a/settings.pl
+++ b/settings.pl
@@ -34,6 +34,95 @@ sub html_escape( $ )
 	return $s;
 }
 
+sub kernel_network_interfaces()
+{
+	my %interfaces = ();
+
+	if( opendir( my $dh, '/sys/class/net' ) )
+	{
+		foreach my $ifname ( readdir( $dh ) )
+		{
+			next if $ifname =~ /^\./;
+			next if $ifname =~ /[^-_\.A-Za-z0-9]/;
+			$interfaces{$ifname} = 1;
+		}
+		closedir( $dh );
+	}
+
+	return %interfaces;
+}
+
+sub ipx_enabled_interfaces()
+{
+	my %ipx_interfaces = ();
+
+	# Modern Linux IPX procfs format:
+	# Network    Node_Address   Primary  Device          Frame_Type
+	# AC100B98   000000000001   Yes      Internal        None
+	# 00000022   508140F6AC45   No       enp46s0u1u3u3   802.2
+	if( open( my $fh, '<', '/proc/net/ipx/interface' ) )
+	{
+		while( my $line = <$fh> )
+		{
+			chomp( $line );
+			$line =~ s/^\s+//;
+			$line =~ s/\s+$//;
+
+			next if $line eq '';
+			next if $line =~ /^Network\s+Node_Address\s+Primary\s+Device\s+Frame_Type/i;
+
+			my @fields = split( /\s+/, $line );
+
+			# Device is the fourth column.  Do not scan all tokens, otherwise
+			# Network/Node/Frame_Type values can accidentally be treated as names.
+			next if scalar( @fields ) < 5;
+
+			my $dev = $fields[3];
+			next if ! defined( $dev );
+			next if $dev eq '';
+			next if lc( $dev ) eq 'internal';
+			next if $dev =~ /[^-_\.A-Za-z0-9]/;
+
+			# Only show real Linux network interfaces.
+			next if ! -e '/sys/class/net/' . $dev;
+
+			$ipx_interfaces{$dev} = 1;
+		}
+
+		close( $fh );
+	}
+
+	# Fallback for older distributions/tools, if present.  This parser is kept
+	# deliberately conservative and still verifies /sys/class/net/<device>.
+	if( open( my $fh, '<', '/proc/net/ipx_interfaces' ) )
+	{
+		while( my $line = <$fh> )
+		{
+			chomp( $line );
+			$line =~ s/^\s+//;
+			$line =~ s/\s+$//;
+
+			next if $line eq '';
+			next if $line =~ /^(Network|Net|Address|Node|Interface|Device)\b/i;
+
+			foreach my $dev ( split( /\s+/, $line ) )
+			{
+				next if ! defined( $dev );
+				next if $dev eq '';
+				next if lc( $dev ) eq 'internal';
+				next if $dev =~ /[^-_\.A-Za-z0-9]/;
+				next if ! -e '/sys/class/net/' . $dev;
+
+				$ipx_interfaces{$dev} = 1;
+			}
+		}
+
+		close( $fh );
+	}
+
+	return sort keys %ipx_interfaces;
+}
+
 sub network_interface_options( $ )
 {
 	my $current = $_[0];
@@ -43,17 +132,14 @@ sub network_interface_options( $ )
 
 	$current = '' unless defined $current;
 
-	if( opendir( my $dh, '/sys/class/net' ) )
+	# Only show interfaces where IPX is currently active.  The current value is
+	# still preserved below, so an existing config entry is not lost if the
+	# interface is temporarily down or IPX is not loaded at display time.
+	foreach my $ifname ( ipx_enabled_interfaces() )
 	{
-		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 );
+		next if $seen{$ifname};
+		push( @interfaces, $ifname );
+		$seen{$ifname} = 1;
 	}
 
 	# Keep special/manual values usable even if they are not real kernel interfaces.
@@ -69,7 +155,7 @@ sub network_interface_options( $ )
 	{
 		my $selected = ( $ifname eq $current ) ? ' SELECTED' : '';
 		my $label = $ifname;
-		$label = '* (all interfaces)' if $ifname eq '*';
+		$label = '* (all IPX 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';
 	}