output/plugin: Load internal plugins

This commit adds an interface for loading plugins that are internal to
Suricata. These are always loaded and are in a modified format from
external pliguns.

src/suricata.c

@@ -2555,6 +2555,7 @@ int PostConfLoadedSetup(SCInstance *suri)
     FeatureTrackingRegister(); /* must occur prior to output mod registration */
     RegisterAllModules();
 #ifdef HAVE_PLUGINS
+    SCInternalLoad();
     SCPluginsLoad(suri->capture_plugin_name, suri->capture_plugin_args);
 #endif
     AppLayerHtpNeedFileInspection();

src/util-plugin.c

@@ -85,6 +85,13 @@ static void InitPlugin(char *path)
     }
 }
 
+/**
+ * \brief Load internal plugins
+ */
+void SCInternalLoad(void)
+{
+}
+
 void SCPluginsLoad(const char *capture_plugin_name, const char *capture_plugin_args)
 {
     ConfNode *conf = ConfGetNode("plugins");

src/util-plugin.h

@@ -20,6 +20,7 @@
 
 #include "suricata-plugin.h"
 
+void SCInternalLoad(void);
 void SCPluginsLoad(const char *capture_plugin_name, const char *capture_plugin_args);
 SCPluginFileType *SCPluginFindFileType(const char *name);
 SCCapturePlugin *SCPluginFindCaptureByName(const char *name);