Fix stale client rejection and terminal cursor mode

tests/integration_smoke.rs

@@ -8,8 +8,8 @@ use dosh::auth::{build_bootstrap, load_or_create_server_secret};
 use dosh::config::load_server_config;
 use dosh::crypto;
 use dosh::protocol::{
-    self, AttachOk, BootstrapAttachRequest, CLIENT_TO_SERVER, Frame, Input, PacketKind, Resize,
-    ResumeRequest, SERVER_TO_CLIENT,
+    self, AttachOk, AttachReject, BootstrapAttachRequest, CLIENT_TO_SERVER, Frame, Input,
+    PacketKind, Resize, ResumeRequest, SERVER_TO_CLIENT,
 };
 
 fn free_udp_port() -> u16 {
@@ -176,6 +176,45 @@ fn collect_frame_text(socket: &UdpSocket, key: &[u8; 32], millis: u64) -> String
     text
 }
 
+#[test]
+fn unknown_live_client_gets_reject() {
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config(&dir, port);
+    let mut server = start_server(&dir, &config);
+    let socket = std::net::UdpSocket::bind("127.0.0.1:0").unwrap();
+    socket
+        .set_read_timeout(Some(Duration::from_secs(2)))
+        .unwrap();
+    let client_id = crypto::random_16();
+    let key = crypto::random_32();
+    let packet = protocol::encode_encrypted(
+        PacketKind::Ping,
+        client_id,
+        1,
+        0,
+        &key,
+        CLIENT_TO_SERVER,
+        b"",
+    )
+    .unwrap();
+
+    socket
+        .send_to(&packet, format!("127.0.0.1:{port}"))
+        .unwrap();
+    let mut buf = [0u8; 65535];
+    let (n, _) = socket.recv_from(&mut buf).unwrap();
+    let packet = protocol::decode(&buf[..n]).unwrap();
+    let reject: AttachReject = protocol::from_body(&packet.body).unwrap();
+
+    let _ = server.kill();
+    let _ = server.wait();
+
+    assert_eq!(packet.header.kind, PacketKind::AttachReject);
+    assert_eq!(packet.header.conn_id, client_id);
+    assert_eq!(reject.reason, "unknown client");
+}
+
 #[test]
 fn local_attach_only_smoke() {
     let dir = tempfile::tempdir().unwrap();