firewall: Avoid creating a rule that permits all traffic on invalid source

The firewall engine generated rules that did not have any traffic
selectors due to an improperly initialized variable in the source.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/config/firewall/rules.pl b/config/firewall/rules.pl
index 30ad20df1d9a31ff86a08784364daf3c24e192dc..1b628df169948f7771005c4a430334ef3af572a4 100644 (file)
--- a/config/firewall/rules.pl
+++ b/config/firewall/rules.pl
@@ -401,6 +401,9 @@ sub buildrules {
                                        $source = "";
                                }
 
+                               # Make sure that $source is properly defined
+                               next unless (defined $source);
+
                                my $source_intf = @$src[1];
 
                                foreach my $dst (@destinations) {