--- loncom/lonnet/perl/londns.pm	2007/03/28 00:12:59	1.1
+++ loncom/lonnet/perl/londns.pm	2017/11/30 14:33:35	1.4
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # A debugging harness.
 #
-# $Id: londns.pm,v 1.1 2007/03/28 00:12:59 albertel Exp $
+# $Id: londns.pm,v 1.4 2017/11/30 14:33:35 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -36,13 +36,16 @@ use Apache::lonnet;
 
 sub serve_file {
     my ($r,$file,$type)=@_;
-    open(my $config,"<$Apache::lonnet::perlvar{'lonTabDir'}/$file");
-    my $file = join('',<$config>);
-    $r->content_type($type);
-    $r->send_http_header;
-    return OK if $r->header_only;
-    $r->print($file);
-    return OK;
+    if (open(my $config,"<","$Apache::lonnet::perlvar{'lonTabDir'}/$file")) {
+        my $contents = join('',<$config>);
+        $r->content_type($type);
+        $r->send_http_header;
+        return OK if $r->header_only;
+        $r->print($contents);
+        return OK;
+    } else {
+        return FORBIDDEN;
+    }
 }
 
 sub handler {
@@ -53,6 +56,9 @@ sub handler {
 	return &serve_file($r,'dns_hosts.tab','loncapa/hosts');
     } elsif ($command eq 'domain') {
 	return &serve_file($r,'dns_domain.tab','loncapa/domain');
+    } elsif ($command eq 'checksums') {
+        my $version = (split('/',$r->uri))[4];
+        return &serve_file($r,"dns_checksums/$version.tab",'loncapa/versions');
     }
     return FORBIDDEN;
 }