1 files changed, 49 insertions, 0 deletions
diff --git a/src/lib.c b/src/lib.c
index cc36292..ec32660 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -88,6 +88,55 @@ stp_validate_token_server (GInetAddressMask  *mask,
   return ret;
 }
 
+gboolean stp_clients_is_subset (char *superset,
+                                char *subset)
+{
+  gsize i, n;
+  gboolean ret;
+  char **supersetv, **subsetv;
+  GHashTable *superset_table = NULL;
+
+  if (!subset)
+    return TRUE;
+
+  if (!superset)
+    return FALSE;
+
+  /* Simplest case */
+  if (g_strcmp0 (superset, subset) == 0)
+    return TRUE;
+
+  subsetv = g_strsplit (subset, ",", 0);
+  supersetv = g_strsplit (superset, ",", 0);
+
+  if (sizeof(supersetv)/sizeof(supersetv[0]) <= 1 ||
+      sizeof(subsetv)/sizeof(subsetv[0]) < 1)
+    /* If there's one client in the superset, and the subset didn't match,
+     * it won't match. Same if there's less than one client in either list. */
+    goto fail;
+
+  /* Easiest way to check. Add superset clients to a table, and then check
+   * whether every subset client is in that table. */
+  superset_table = g_hash_table_new (g_str_hash, g_str_equal);
+  for (i = 0, n = sizeof(supersetv)/sizeof(supersetv[0]); i < n; i++)
+    g_hash_table_add (superset_table, supersetv[i]);
+
+  for (i = 0, n = sizeof(subsetv)/sizeof(subsetv[0]); i < n; i++)
+    if (!g_hash_table_contains (superset_table, subsetv[i]))
+      goto fail;
+
+  ret = TRUE;
+out:
+  if (superset_table)
+    g_hash_table_destroy (superset_table);
+  g_strfreev (supersetv);
+  g_strfreev (subsetv);
+  return ret;
+fail:
+  ret = FALSE;
+  goto out;
+}
+
 gboolean
 stp_on_gst_bus_message (GstBus       *bus,
                         GstMessage   *msg,