Add support for allowlists

allowlists/.gitignore

@@ -0,0 +1,6 @@
+# Ignore everything in this directory
+*
+# Except this file
+!.gitignore
+# ... And some others
+!/allowlist.domains.example

allowlists/allowlist.domains.example

@@ -0,0 +1,8 @@
+# Omit these domains from the blocklist.
+#
+# Must be in a file called *.domains in this directory.
+# Comments are allowed. One domain per line.
+#
+# Examples:
+# domain1.example.com
+# domain2.example.com

make-block.pl

@@ -23,6 +23,7 @@ use FindBin qw//;
 my %domains;
 my $dupes = 0;
 my $skip = 0;
+my $removed_allowed = 0;
 sub add_domain_list {
     my $file = shift;
     foreach my $line (&read_stripped($file)) {
@@ -82,6 +83,7 @@ MAIN: {
 
     my @domain_lists = glob "$workdir/lists/*.domains";
     my @hosts_lists = glob "$workdir/lists/*.hosts";
+    my @allow_lists = glob "$workdir/allowlists/*.domains";
 
     foreach my $listfile (@domain_lists) {
         &add_domain_list($listfile);
@@ -90,6 +92,16 @@ MAIN: {
         &add_host_file($hostfile);
     }
 
+    # Apply allowlists
+    my @allow_domains;
+    foreach my $allowlist (@allow_lists) {
+        push @allow_domains, &read_stripped($allowlist);
+    }
+    my $before = %domains;
+    delete %domains{@allow_domains};
+    # Count number removed
+    $removed_allowed = $before - %domains;
+
     my $written = 0;
     my $fho = \*STDOUT;
     if (defined $out && length $out) {
@@ -109,5 +121,6 @@ MAIN: {
     printf STDERR " - %d .domains files\n", (scalar @domain_lists);
     printf STDERR " - %d .hosts files\n", (scalar @hosts_lists);
     printf STDERR "(%d duplicates)\n", $dupes if $dupes;
+    printf STDERR "(%d domains removed via allowlist)\n", $removed_allowed if $removed_allowed;
     printf STDERR "(%d skipped)\n", $skip if $skip;
 }