--- loncom/lonnet/perl/lonnet.pm	2007/10/01 21:06:04	1.915
+++ loncom/lonnet/perl/lonnet.pm	2007/10/01 21:52:57	1.916
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.915 2007/10/01 21:06:04 albertel Exp $
+# $Id: lonnet.pm,v 1.916 2007/10/01 21:52:57 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -397,6 +397,34 @@ sub transfer_profile_to_env {
     }
 }
 
+# ---------------------------------------------------- Check for valid session 
+sub check_for_valid_session {
+    my ($r) = @_;
+    my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
+    my $lonid=$cookies{'lonID'};
+    return undef if (!$lonid);
+
+    my $handle=&LONCAPA::clean_handle($lonid->value);
+    my $lonidsdir=$r->dir_config('lonIDsDir');
+    return undef if (!-e "$lonidsdir/$handle.id");
+
+    open(my $idf,'+<',"$lonidsdir/$handle.id");
+    return undef if (!$idf);
+
+    flock($idf,LOCK_SH);
+    my %disk_env;
+    if (!tie(%disk_env,'GDBM_File',"$lonidsdir/$handle.id",
+	    &GDBM_READER(),0640)) {
+	return undef;	
+    }
+
+    if (!defined($disk_env{'user.name'})
+	|| !defined($disk_env{'user.domain'})) {
+	return undef;
+    }
+    return $handle;
+}
+
 sub timed_flock {
     my ($file,$lock_type) = @_;
     my $failed=0;