control_server: node subscription protocol with output queue, push notifications on routing changes

src/control_server.h

@@ -19,6 +19,8 @@ extern "C" {
 /* Forward declarations */
 struct UTUN_INSTANCE;
 struct UASYNC;
+struct NODEINFO_Q;
+struct ll_queue;
 
 /* Forward declaration */
 struct control_server;
@@ -36,9 +38,10 @@ struct control_client {
     
     /* Selected connection */
     uint64_t selected_peer_id;          /* 0 = none selected */
-    
-    /* Client state */
-//    uint8_t connected;
+
+    struct ll_queue* output_queue;      /* Output queue for async sends */
+    uint8_t subscribed_nodes;           /* 1 = subscribed to node updates */
+    uint8_t write_registered;           /* 1 = write events registered in uasync */
 };
 
 /* Control server state */
@@ -113,6 +116,9 @@ void control_server_process_updates(struct control_server* server);
  */
 uint32_t control_server_get_client_count(const struct control_server* server);
 
+void control_server_notify_node_change(struct control_server* server, struct NODEINFO_Q* node);
+void control_server_notify_node_removed(struct control_server* server, uint64_t node_id);
+
 #ifdef __cplusplus
 }
 #endif