From f88cd790dee58a4c35df5fba80e1f558bf75cf6a Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Thu, 1 Jul 2010 10:32:27 +0200
Subject: [PATCH] new functions @eq, @ne, @not

---
 NEWS         |  1 +
 doc/ferm.pod | 14 ++++++++++++++
 src/ferm     | 16 ++++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/NEWS b/NEWS
index af21582..a9ee16d 100644
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,7 @@ v2.0.8 - not yet released
   - added automatic variable $DIRNAME
   - implement confirmation/rollback for --shell --interactive
   - added the "type" parameter to @resolve()
+  - new functions @eq, @ne, @not
 
 
 v2.0.7 - 2 Jan 2010
diff --git a/doc/ferm.pod b/doc/ferm.pod
index b9ec488..9660a96 100644
--- a/doc/ferm.pod
+++ b/doc/ferm.pod
@@ -1603,6 +1603,20 @@ hooks.
 
 There are several built-in functions which you might find useful.
 
+=head2 @eq(a,b)
+
+Tests two values for equality.  Example:
+
+    @if @eq($DOMAIN, ip6) DROP;
+
+=head2 @ne(a,b)
+
+Similar to @eq, this tests for non-equality.
+
+=head2 @not(x)
+
+Negates a boolean value.
+
 =head2 @resolve((hostname1 hostname2 ...), [type])
 
 Usually, host names are resolved by iptables.  To let ferm resolve
diff --git a/src/ferm b/src/ferm
index 26752e5..5af275f 100755
--- a/src/ferm
+++ b/src/ferm
@@ -943,6 +943,10 @@ sub negate_value($$;$) {
     return bless [ $value ], $class || 'negated';
 }
 
+sub format_bool($) {
+    return $_[0] ? 1 : 0;
+}
+
 sub resolve($\@$) {
     my ($resolver, $names, $type) = @_;
 
@@ -1090,6 +1094,18 @@ sub getvalues {
             my $resolver = new Net::DNS::Resolver;
             my @params = to_array($params[0]);
             return [resolve($resolver, @params, $type)];
+        } elsif ($token eq '@eq') {
+            my @params = get_function_params();
+            error('Usage: @eq(a, b)') unless @params == 2;
+            return format_bool($params[0] eq $params[1]);
+        } elsif ($token eq '@ne') {
+            my @params = get_function_params();
+            error('Usage: @ne(a, b)') unless @params == 2;
+            return format_bool($params[0] ne $params[1]);
+        } elsif ($token eq '@not') {
+            my @params = get_function_params();
+            error('Usage: @eq(a, b)') unless @params == 1;
+            return format_bool(not $params[0]);
         } else {
             error("unknown ferm built-in function");
         }
-- 
2.11.4.GIT