Add noexport bit to prevent some (Windows) from URL export.

sql/database-create.sql

@@ -1884,6 +1884,7 @@ CREATE TABLE `images` (
   `metadata_url` tinytext,
   `imagefile_url` tinytext,
   `logfileid` varchar(40) default NULL,
+  `noexport` tinyint(1) NOT NULL default '0',
   PRIMARY KEY  (`imageid`),
   UNIQUE KEY `pid` (`pid`,`imagename`),
   KEY `gid` (`gid`),

sql/updates/4/360

+#
+# Add noexport flag to images.
+#
+use strict;
+use libdb;
+
+my $impotent = 0;
+
+sub DoUpdate($$$)
+{
+    my ($dbhandle, $dbname, $version) = @_;
+
+    if (!DBSlotExists("images", "noexport")) {
+	DBQueryFatal("alter table images add  ".
+		     " `noexport` tinyint(1) NOT NULL default '0'");
+    }
+    return 0;
+}
+
+# Local Variables:
+# mode:perl
+# End:

utils/spewimage.in

 #!/usr/bin/perl -wT
 #
-# Copyright (c) 2000-2007 University of Utah and the Flux Group.
+# Copyright (c) 2000-2013 University of Utah and the Flux Group.
 # 
 # {{{EMULAB-LICENSE
 # 
@@ -190,6 +190,16 @@ sub SpewImage()
 #
 sub VerifyImage()
 {
+    #
+    # Some images are not allowed to be exported.
+    #
+    if ($image->noexport()) {
+	if ($debug) {
+	    print STDERR "Not allowed to export this image!\n";
+	}
+	return 1;
+    }
+    
     #
     # The current user needs to be able to read the image file and must
     # have provided proper access key.