Use static plugin features in libcharon to define essential dependencies

src/charon-nm/nm/nm_backend.c

@@ -167,6 +167,7 @@ void nm_backend_register()
 	static plugin_feature_t features[] = {
 		PLUGIN_CALLBACK((plugin_feature_callback_t)nm_backend_cb, NULL),
 			PLUGIN_PROVIDE(CUSTOM, "NetworkManager backend"),
+				PLUGIN_DEPENDS(CUSTOM, "libcharon"),
 	};
 	lib->plugins->add_static_features(lib->plugins, "nm-backend", features,
 									  countof(features), TRUE);

src/libcharon/daemon.c

@@ -32,7 +32,7 @@
 #include "daemon.h"
 
 #include <library.h>
-#include <plugins/plugin.h>
+#include <plugins/plugin_feature.h>
 #include <config/proposal.h>
 #include <kernel/kernel_handler.h>
 #include <processing/jobs/start_action_job.h>
@@ -213,6 +213,15 @@ METHOD(daemon_t, start, void,
 METHOD(daemon_t, initialize, bool,
 	private_daemon_t *this, char *plugins)
 {
+	static plugin_feature_t features[] = {
+		PLUGIN_PROVIDE(CUSTOM, "libcharon"),
+			PLUGIN_DEPENDS(HASHER, HASH_SHA1),
+			PLUGIN_DEPENDS(RNG, RNG_STRONG),
+			PLUGIN_DEPENDS(NONCE_GEN),
+	};
+	lib->plugins->add_static_features(lib->plugins, charon->name, features,
+									  countof(features), TRUE);
+
 	/* load plugins, further infrastructure may need it */
 	if (!lib->plugins->load(lib->plugins, NULL, plugins))
 	{