feat(agent): add window recording support to now proto dvc

pacmancoder · pacmancoder · commit ba819d34012f · 2026-01-27T18:01:50.000+02:00
diff --git a/devolutions-session/Cargo.toml b/devolutions-session/Cargo.toml
@@ -59,6 +59,7 @@ optional = true
 features = [
     "Win32_Foundation",
     "Win32_System_Shutdown",
+    "Win32_UI_Accessibility",
     "Win32_UI_WindowsAndMessaging",
     "Win32_UI_Shell",
     "Win32_System_Console",
diff --git a/devolutions-session/src/dvc/mod.rs b/devolutions-session/src/dvc/mod.rs
@@ -40,5 +40,6 @@ pub mod now_message_dissector;
 pub mod process;
 pub mod rdm;
 pub mod task;
+pub mod window_monitor;
 
 mod env;
diff --git a/devolutions-session/src/dvc/process.rs b/devolutions-session/src/dvc/process.rs
@@ -92,6 +92,9 @@ pub enum ServerChannelEvent {
         session_id: u32,
         error: ExecError,
     },
+    WindowRecordingEvent {
+        message: now_proto_pdu::OwnedNowSessionWindowRecEventMsg,
+    },
 }
 
 pub struct WinApiProcessCtx {
diff --git a/devolutions-session/src/dvc/task.rs b/devolutions-session/src/dvc/task.rs
@@ -9,8 +9,9 @@ use now_proto_pdu::{
     NowExecBatchMsg, NowExecCancelRspMsg, NowExecCapsetFlags, NowExecDataMsg, NowExecDataStreamKind, NowExecMessage,
     NowExecProcessMsg, NowExecPwshMsg, NowExecResultMsg, NowExecRunMsg, NowExecStartedMsg, NowExecWinPsMsg, NowMessage,
     NowMsgBoxResponse, NowProtoError, NowProtoVersion, NowRdmMessage, NowSessionCapsetFlags, NowSessionMessage,
-    NowSessionMsgBoxReqMsg, NowSessionMsgBoxRspMsg, NowStatusError, NowSystemCapsetFlags, NowSystemMessage,
-    SetKbdLayoutOption,
+    NowSessionMsgBoxRspMsg, NowSessionWindowRecStartMsg, NowStatusError, NowSystemCapsetFlags, NowSystemMessage,
+    OwnedNowExecResultMsg, OwnedNowMessage, OwnedNowSessionMsgBoxReqMsg, OwnedNowSessionWindowRecEventMsg,
+    SetKbdLayoutOption, WindowRecStartFlags,
 };
 use tokio::select;
 use tokio::sync::mpsc::{self, Receiver, Sender};
@@ -39,6 +40,7 @@ use crate::dvc::fs::TmpFileGuard;
 use crate::dvc::io::run_dvc_io;
 use crate::dvc::process::{ExecError, ServerChannelEvent, WinApiProcess, WinApiProcessBuilder};
 use crate::dvc::rdm::RdmMessageProcessor;
+use crate::dvc::window_monitor::{WindowMonitorConfig, run_window_monitor};
 
 // One minute heartbeat interval by default
 const DEFAULT_HEARTBEAT_INTERVAL: core::time::Duration = core::time::Duration::from_secs(60);
@@ -107,8 +109,8 @@ impl Task for DvcIoTask {
 }
 
 async fn process_messages(
-    mut read_rx: Receiver<NowMessage<'static>>,
-    dvc_tx: WinapiSignaledSender<NowMessage<'static>>,
+    mut read_rx: Receiver<OwnedNowMessage>,
+    dvc_tx: WinapiSignaledSender<OwnedNowMessage>,
     mut shutdown_signal: devolutions_gateway_task::ShutdownSignal,
 ) -> anyhow::Result<()> {
     let (io_notification_tx, mut task_rx) = mpsc::channel(100);
@@ -230,6 +232,11 @@ async fn process_messages(
 
                                 handle_exec_error(&dvc_tx, session_id, error).await;
                             }
+                            ServerChannelEvent::WindowRecordingEvent { message } => {
+                                if let Err(error) = handle_window_recording_event(&dvc_tx, message).await {
+                                    error!(%error, "Failed to handle window recording event");
+                                }
+                            }
                             ServerChannelEvent::CloseChannel => {
                                 info!("Received close channel notification, shutting down...");
 
@@ -266,7 +273,8 @@ fn default_server_caps() -> NowChannelCapsetMsg {
             NowSessionCapsetFlags::LOCK
                 | NowSessionCapsetFlags::LOGOFF
                 | NowSessionCapsetFlags::MSGBOX
-                | NowSessionCapsetFlags::SET_KBD_LAYOUT,
+                | NowSessionCapsetFlags::SET_KBD_LAYOUT
+                | NowSessionCapsetFlags::WINDOW_RECORDING,
         )
         .with_exec_capset(
             NowExecCapsetFlags::STYLE_RUN
@@ -285,18 +293,22 @@ enum ProcessMessageAction {
 }
 
 struct MessageProcessor {
-    dvc_tx: WinapiSignaledSender<NowMessage<'static>>,
+    dvc_tx: WinapiSignaledSender<OwnedNowMessage>,
     io_notification_tx: Sender<ServerChannelEvent>,
     #[allow(dead_code)] // Not yet used.
     capabilities: NowChannelCapsetMsg,
     sessions: HashMap<u32, WinApiProcess>,
     rdm_handler: RdmMessageProcessor,
+    /// Shutdown signal sender for window monitoring task.
+    window_monitor_shutdown_tx: Option<tokio::sync::oneshot::Sender<()>>,
+    /// Handle for the window monitor task.
+    window_monitor_handle: Option<tokio::task::JoinHandle<()>>,
 }
 
 impl MessageProcessor {
     pub(crate) fn new(
         capabilities: NowChannelCapsetMsg,
-        dvc_tx: WinapiSignaledSender<NowMessage<'static>>,
+        dvc_tx: WinapiSignaledSender<OwnedNowMessage>,
         io_notification_tx: Sender<ServerChannelEvent>,
     ) -> Self {
         let rdm_handler = RdmMessageProcessor::new(dvc_tx.clone());
@@ -306,6 +318,8 @@ impl MessageProcessor {
             capabilities,
             sessions: HashMap::new(),
             rdm_handler,
+            window_monitor_shutdown_tx: None,
+            window_monitor_handle: None,
         }
     }
 
@@ -330,10 +344,7 @@ impl MessageProcessor {
         Ok(())
     }
 
-    pub(crate) async fn process_message(
-        &mut self,
-        message: NowMessage<'static>,
-    ) -> anyhow::Result<ProcessMessageAction> {
+    pub(crate) async fn process_message(&mut self, message: OwnedNowMessage) -> anyhow::Result<ProcessMessageAction> {
         match message {
             NowMessage::Channel(NowChannelMessage::Capset(client_caps)) => {
                 return Ok(ProcessMessageAction::Restart(client_caps));
@@ -470,6 +481,14 @@ impl MessageProcessor {
                     error!(%error, "Failed to set keyboard layout");
                 }
             }
+            NowMessage::Session(NowSessionMessage::WindowRecStart(start_msg)) => {
+                if let Err(error) = self.start_window_recording(start_msg).await {
+                    error!(%error, "Failed to start window recording");
+                }
+            }
+            NowMessage::Session(NowSessionMessage::WindowRecStop(_stop_msg)) => {
+                self.stop_window_recording().await;
+            }
             NowMessage::System(NowSystemMessage::Shutdown(shutdown_msg)) => {
                 let mut current_process_token =
                     Process::current_process().token(TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY)?;
@@ -773,6 +792,56 @@ impl MessageProcessor {
 
         self.sessions.clear();
     }
+
+    async fn start_window_recording(&mut self, start_msg: NowSessionWindowRecStartMsg) -> anyhow::Result<()> {
+        // Stop any existing window recording first.
+        self.stop_window_recording().await;
+
+        info!("Starting window recording");
+
+        let track_title_changes = start_msg.flags.contains(WindowRecStartFlags::TRACK_TITLE_CHANGE);
+
+        // Create shutdown channel for window monitor.
+        let (shutdown_tx, shutdown_rx) = tokio::sync::oneshot::channel();
+
+        // Store shutdown sender so we can stop monitoring later.
+        self.window_monitor_shutdown_tx = Some(shutdown_tx);
+
+        // Spawn window monitor task.
+        let event_tx = self.io_notification_tx.clone();
+        let poll_interval = start_msg.poll_interval;
+        let window_monitor_handle = tokio::task::spawn(async move {
+            let mut config = WindowMonitorConfig::new(event_tx, track_title_changes, shutdown_rx);
+
+            // Only set custom poll interval if specified (non-zero).
+            if poll_interval > 0 {
+                config = config.with_poll_interval_ms(u64::from(poll_interval));
+            }
+
+            if let Err(error) = run_window_monitor(config).await {
+                error!(%error, "Window monitor failed");
+            }
+        });
+
+        self.window_monitor_handle = Some(window_monitor_handle);
+
+        Ok(())
+    }
+
+    async fn stop_window_recording(&mut self) {
+        if let Some(shutdown_tx) = self.window_monitor_shutdown_tx.take() {
+            info!("Stopping window recording");
+            // Send shutdown signal (ignore errors if receiver was already dropped).
+            let _ = shutdown_tx.send(());
+
+            // Wait for the task to finish.
+            if let Some(handle) = self.window_monitor_handle.take()
+                && let Err(error) = handle.await
+            {
+                error!(%error, "Window monitor task panicked");
+            }
+        }
+    }
 }
 
 fn append_ps_args(args: &mut Vec<String>, msg: &NowExecWinPsMsg<'_>) {
@@ -859,7 +928,7 @@ fn append_pwsh_args(args: &mut Vec<String>, msg: &NowExecPwshMsg<'_>) {
     }
 }
 
-fn show_message_box<'a>(request: &NowSessionMsgBoxReqMsg<'static>) -> NowSessionMsgBoxRspMsg<'a> {
+fn show_message_box<'a>(request: &OwnedNowSessionMsgBoxReqMsg) -> NowSessionMsgBoxRspMsg<'a> {
     info!("Processing message box request `{}`", request.request_id());
 
     let title = WideString::from(request.title().unwrap_or("Devolutions Session"));
@@ -913,10 +982,7 @@ fn show_message_box<'a>(request: &NowSessionMsgBoxReqMsg<'static>) -> NowSession
     NowSessionMsgBoxRspMsg::new_success(request.request_id(), NowMsgBoxResponse::new(message_box_response))
 }
 
-async fn process_msg_box_req(
-    request: NowSessionMsgBoxReqMsg<'static>,
-    dvc_tx: WinapiSignaledSender<NowMessage<'static>>,
-) {
+async fn process_msg_box_req(request: OwnedNowSessionMsgBoxReqMsg, dvc_tx: WinapiSignaledSender<OwnedNowMessage>) {
     let response = show_message_box(&request).into_owned();
 
     if !request.is_response_expected() {
@@ -928,7 +994,7 @@ async fn process_msg_box_req(
     }
 }
 
-fn make_status_error_failsafe(session_id: u32, error: NowStatusError) -> NowExecResultMsg<'static> {
+fn make_status_error_failsafe(session_id: u32, error: NowStatusError) -> OwnedNowExecResultMsg {
     NowExecResultMsg::new_error(session_id, error)
         .unwrap_or_else(|error| {
             warn!(%error, "Now status error message do not fit into NOW-PROTO error message; sending error without message");
@@ -937,7 +1003,7 @@ fn make_status_error_failsafe(session_id: u32, error: NowStatusError) -> NowExec
         })
 }
 
-fn make_generic_error_failsafe(session_id: u32, code: u32, message: String) -> NowExecResultMsg<'static> {
+fn make_generic_error_failsafe(session_id: u32, code: u32, message: String) -> OwnedNowExecResultMsg {
     let error = NowStatusError::new_generic(code);
 
     error
@@ -950,7 +1016,16 @@ fn make_generic_error_failsafe(session_id: u32, code: u32, message: String) -> N
         })
 }
 
-async fn handle_exec_error(dvc_tx: &WinapiSignaledSender<NowMessage<'static>>, session_id: u32, error: ExecError) {
+async fn handle_window_recording_event(
+    dvc_tx: &WinapiSignaledSender<OwnedNowMessage>,
+    message: OwnedNowSessionWindowRecEventMsg,
+) -> anyhow::Result<()> {
+    dvc_tx.send(NowMessage::from(message.into_owned())).await?;
+
+    Ok(())
+}
+
+async fn handle_exec_error(dvc_tx: &WinapiSignaledSender<OwnedNowMessage>, session_id: u32, error: ExecError) {
     let msg = match error {
         ExecError::NowStatus(status) => {
             warn!(%session_id, %status, "Process execution failed with NOW-PROTO error");
diff --git a/devolutions-session/src/dvc/window_monitor.rs b/devolutions-session/src/dvc/window_monitor.rs

Original file line number	Diff line number	Diff line change
`@@ -92,6 +92,9 @@ pub enum ServerChannelEvent {`
`92`	`92`	`session_id: u32,`
`93`	`93`	`error: ExecError,`
`94`	`94`	`},`
	`95`	`+ WindowRecordingEvent {`
	`96`	`+ message: now_proto_pdu::OwnedNowSessionWindowRecEventMsg,`
	`97`	`+ },`
`95`	`98`	`}`
`96`	`99`
`97`	`100`	`pub struct WinApiProcessCtx {`