tests: Allow unit tests to run as root.

The unit tests did not allow users to run them as root because
ovs-vswitchd would destroy all of the existing 'system' datapaths.
This patch prevents ovs-vswitchd from registering 'system'
datapaths when running unit tests preventing the issue.

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/dpif.c b/lib/dpif.c
index cc6e805f..5f5417b7 100644
--- a/lib/dpif.c
+++ b/lib/dpif.c
@@ -68,6 +68,7 @@ struct registered_dpif_class {
     int refcount;
 };
 static struct shash dpif_classes = SHASH_INITIALIZER(&dpif_classes);
+static struct sset dpif_blacklist = SSET_INITIALIZER(&dpif_blacklist);
 
 /* Rate limit for individual messages going to or from the datapath, output at
  * DBG level.  This is very high because, if these are enabled, it is because
@@ -108,6 +109,12 @@ dp_register_provider(const struct dpif_class *new_class)
 {
     struct registered_dpif_class *registered_class;
 
+    if (sset_contains(&dpif_blacklist, new_class->type)) {
+        VLOG_DBG("attempted to register blacklisted provider: %s",
+                 new_class->type);
+        return EINVAL;
+    }
+
     if (shash_find(&dpif_classes, new_class->type)) {
         VLOG_WARN("attempted to register duplicate datapath provider: %s",
                   new_class->type);
@@ -151,6 +158,14 @@ dp_unregister_provider(const char *type)
     return 0;
 }
 
+/* Blacklists a provider.  Causes future calls of dp_register_provider() with
+ * a dpif_class which implements 'type' to fail. */
+void
+dp_blacklist_provider(const char *type)
+{
+    sset_add(&dpif_blacklist, type);
+}
+
 /* Clears 'types' and enumerates the types of all currently registered datapath
  * providers into it.  The caller must first initialize the sset. */
 void