Add uasync socket polling for ETCP packet reception

src/etcp_connections.c

@@ -15,6 +15,8 @@
 #include <stdlib.h>
 static void etcp_connections_read_callback(int fd, void* arg);
 
+static void etcp_connections_read_callback(int fd, void* arg);
+
 #include <time.h>
 
 // Simple debug macros to replace missing debug_config.h
@@ -262,6 +264,11 @@ struct ETCP_SOCKET* etcp_socket_add(struct UTUN_INSTANCE* instance, struct socka
     e_sock->instance = instance;
     e_sock->errorcode = 0;
     e_sock->pkt_format_errors = 0;
+    e_sock->socket_id = uasync_add_socket(instance->ua, e_sock->fd,
+                                          etcp_connections_read_callback,
+                                          NULL, NULL, e_sock);
+    printf("[SOCKET] Registered ETCP socket fd=%d with callback %p
+", e_sock->fd, etcp_connections_read_callback);
     
     // Add to instance's socket list
     e_sock->next = instance->etcp_sockets;