lan discovery in socket_cs

Signed-off-by: fufesou <shuanglongchen@yeah.net>

libs/socket_cs/src/lib.rs

@@ -0,0 +1,12 @@
+use async_trait::async_trait;
+pub use hbb_common::ResultType;
+pub mod discovery;
+pub mod udp;
+
+const CMD_TOKEN: u8 = '\n' as u8;
+
+/// Use tower::Service may be better ?
+#[async_trait]
+pub trait Handler<Request>: Send + Sync {
+    async fn call(&self, request: Request) -> ResultType<()>;
+}