GUACAMOLE-1231: Implement basic support for restoring minimized RAIL …

…windows.

src/protocols/rdp/channels/rail.c

@@ -26,27 +26,15 @@
 #include <freerdp/event.h>
 #include <freerdp/freerdp.h>
 #include <freerdp/rail.h>
+#include <freerdp/window.h>
 #include <guacamole/client.h>
+#include <guacamole/mem.h>
 #include <winpr/wtypes.h>
 #include <winpr/wtsapi.h>
 
 #include <stddef.h>
 #include <string.h>
 
-#ifdef FREERDP_RAIL_CALLBACKS_REQUIRE_CONST
-/**
- * FreeRDP 2.0.0-rc4 and newer requires the final argument for all RAIL
- * callbacks to be const.
- */
-#define RAIL_CONST const
-#else
-/**
- * FreeRDP 2.0.0-rc3 and older requires the final argument for all RAIL
- * callbacks to NOT be const.
- */
-#define RAIL_CONST
-#endif
-
 /**
  * Completes initialization of the RemoteApp session, responding to the server
  * handshake, sending client status and system parameters, and executing the
@@ -86,6 +74,7 @@ static UINT guac_rdp_rail_complete_handshake(RailClientContext* rail) {
     };
 
     /* Send client handshake response */
+    guac_client_log(client, GUAC_LOG_DEBUG, "Sending RAIL handshake.");
     pthread_mutex_lock(&(rdp_client->message_lock));
     status = rail->ClientHandshake(rail, &handshake);
     pthread_mutex_unlock(&(rdp_client->message_lock));
@@ -94,10 +83,13 @@ static UINT guac_rdp_rail_complete_handshake(RailClientContext* rail) {
         return status;
 
     RAIL_CLIENT_STATUS_ORDER client_status = {
-        .flags = 0x00
+        .flags =
+                TS_RAIL_CLIENTSTATUS_ALLOWLOCALMOVESIZE
+              | TS_RAIL_CLIENTSTATUS_APPBAR_REMOTING_SUPPORTED
     };
 
     /* Send client status */
+    guac_client_log(client, GUAC_LOG_DEBUG, "Sending RAIL client status.");
     pthread_mutex_lock(&(rdp_client->message_lock));
     status = rail->ClientInformation(rail, &client_status);
     pthread_mutex_unlock(&(rdp_client->message_lock));
@@ -135,8 +127,7 @@ static UINT guac_rdp_rail_complete_handshake(RailClientContext* rail) {
         },
 
         .params =
-              SPI_MASK_SET_DRAG_FULL_WINDOWS
-            | SPI_MASK_SET_HIGH_CONTRAST
+              SPI_MASK_SET_HIGH_CONTRAST
             | SPI_MASK_SET_KEYBOARD_CUES
             | SPI_MASK_SET_KEYBOARD_PREF
             | SPI_MASK_SET_MOUSE_BUTTON_SWAP
@@ -145,6 +136,7 @@ static UINT guac_rdp_rail_complete_handshake(RailClientContext* rail) {
     };
 
     /* Send client system parameters */
+    guac_client_log(client, GUAC_LOG_DEBUG, "Sending RAIL client system parameters.");
     pthread_mutex_lock(&(rdp_client->message_lock));
     status = rail->ClientSystemParam(rail, &sysparam);
     pthread_mutex_unlock(&(rdp_client->message_lock));
@@ -160,6 +152,7 @@ static UINT guac_rdp_rail_complete_handshake(RailClientContext* rail) {
     };
 
     /* Execute desired RemoteApp command */
+    guac_client_log(client, GUAC_LOG_DEBUG, "Executing remote application.");
     pthread_mutex_lock(&(rdp_client->message_lock));
     status = rail->ClientExecute(rail, &exec);
     pthread_mutex_unlock(&(rdp_client->message_lock));
@@ -189,6 +182,8 @@ static UINT guac_rdp_rail_complete_handshake(RailClientContext* rail) {
  */
 static UINT guac_rdp_rail_handshake(RailClientContext* rail,
         RAIL_CONST RAIL_HANDSHAKE_ORDER* handshake) {
+    guac_client* client = (guac_client*) rail->custom;
+    guac_client_log(client, GUAC_LOG_TRACE, "RAIL handshake callback.");
     return guac_rdp_rail_complete_handshake(rail);
 }
 
@@ -213,9 +208,63 @@ static UINT guac_rdp_rail_handshake(RailClientContext* rail,
  */
 static UINT guac_rdp_rail_handshake_ex(RailClientContext* rail,
         RAIL_CONST RAIL_HANDSHAKE_EX_ORDER* handshake_ex) {
+    guac_client* client = (guac_client*) rail->custom;
+    guac_client_log(client, GUAC_LOG_TRACE, "RAIL handshake ex callback.");
     return guac_rdp_rail_complete_handshake(rail);
 }
 
+/**
+ * A callback function that is executed when an update for a RAIL window is
+ * received from the RDP server.
+ *
+ * @param context
+ *     A pointer to the rdpContext structure used by FreeRDP to handle the
+ *     window update.
+ *
+ * @param orderInfo
+ *     A pointer to the data structure that contains information about what
+ *     window was updated what updates were performed.
+ *
+ * @param windowState
+ *     A pointer to the data structure that contains details of the updates
+ *     to the window, as indicated by flags in the orderInfo field.
+ *
+ * @return
+ *     TRUE if the client-side processing of the updates as successful; otherwise
+ *     FALSE. This implementation always returns TRUE.
+ */
+static BOOL guac_rdp_rail_window_update(rdpContext* context,
+        RAIL_CONST WINDOW_ORDER_INFO* orderInfo,
+        RAIL_CONST WINDOW_STATE_ORDER* windowState) {
+
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+
+    guac_client_log(client, GUAC_LOG_TRACE, "RAIL window update callback: %d", orderInfo->fieldFlags);
+
+    UINT32 fieldFlags = orderInfo->fieldFlags;
+
+    /* If the flag for window visibilty is set, check visibility. */
+    if (fieldFlags & WINDOW_ORDER_FIELD_SHOW) {
+        guac_client_log(client, GUAC_LOG_TRACE, "RAIL window visibility change: %d", windowState->showState);
+
+        /* State is either hidden or minimized - send restore command. */
+        if (windowState->showState == GUAC_RDP_RAIL_WINDOW_STATE_HIDDEN
+            || windowState->showState == GUAC_RDP_RAIL_WINDOW_STATE_MINIMIZED) {
+
+            guac_client_log(client, GUAC_LOG_DEBUG, "RAIL window minimized, sending restore command.");
+
+            RAIL_SYSCOMMAND_ORDER syscommand;
+            syscommand.windowId = orderInfo->windowId;
+            syscommand.command = SC_RESTORE;
+            rdp_client->rail_interface->ClientSystemCommand(rdp_client->rail_interface, &syscommand);
+        }
+    }
+
+    return true;
+
+}
+
 /**
  * Callback which associates handlers specific to Guacamole with the
  * RailClientContext instance allocated by FreeRDP to deal with received
@@ -238,6 +287,7 @@ static void guac_rdp_rail_channel_connected(rdpContext* context,
         ChannelConnectedEventArgs* args) {
 
     guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
 
     /* Ignore connection event if it's not for the RAIL channel */
     if (strcmp(args->name, RAIL_SVC_CHANNEL_NAME) != 0)
@@ -246,12 +296,14 @@ static void guac_rdp_rail_channel_connected(rdpContext* context,
     /* The structure pointed to by pInterface is guaranteed to be a
      * RailClientContext if the channel is RAIL */
     RailClientContext* rail = (RailClientContext*) args->pInterface;
+    rdp_client->rail_interface = rail;
 
     /* Init FreeRDP RAIL context, ensuring the guac_client can be accessed from
      * within any RAIL-specific callbacks */
     rail->custom = client;
     rail->ServerHandshake = guac_rdp_rail_handshake;
     rail->ServerHandshakeEx = guac_rdp_rail_handshake_ex;
+    context->update->window->WindowUpdate = guac_rdp_rail_window_update;
 
     guac_client_log(client, GUAC_LOG_DEBUG, "RAIL (RemoteApp) channel "
             "connected.");
@@ -280,4 +332,3 @@ void guac_rdp_rail_load_plugin(rdpContext* context) {
             "registered. Awaiting channel connection.");
 
 }
-

src/protocols/rdp/channels/rail.h

@@ -20,7 +20,34 @@
 #ifndef GUAC_RDP_CHANNELS_RAIL_H
 #define GUAC_RDP_CHANNELS_RAIL_H
 
+#include "config.h"
+
 #include <freerdp/freerdp.h>
+#include <freerdp/window.h>
+
+#ifdef FREERDP_RAIL_CALLBACKS_REQUIRE_CONST
+/**
+ * FreeRDP 2.0.0-rc4 and newer requires the final argument for all RAIL
+ * callbacks to be const.
+ */
+#define RAIL_CONST const
+#else
+/**
+ * FreeRDP 2.0.0-rc3 and older requires the final argument for all RAIL
+ * callbacks to NOT be const.
+ */
+#define RAIL_CONST
+#endif
+
+/**
+ * The RAIL window state that indicates a hidden window.
+ */
+#define GUAC_RDP_RAIL_WINDOW_STATE_HIDDEN 0x00
+
+/**
+ * The RAIL window state that indicates a visible but minimized window.
+ */
+#define GUAC_RDP_RAIL_WINDOW_STATE_MINIMIZED 0x02
 
 /**
  * Initializes RemoteApp support for RDP and handling of the RAIL channel. If

src/protocols/rdp/client.c

@@ -22,6 +22,7 @@
 #include "channels/cliprdr.h"
 #include "channels/disp.h"
 #include "channels/pipe-svc.h"
+#include "channels/rail.h"
 #include "config.h"
 #include "fs.h"
 #include "log.h"

src/protocols/rdp/rdp.h

@@ -42,6 +42,7 @@
 
 #include <freerdp/codec/color.h>
 #include <freerdp/freerdp.h>
+#include <freerdp/client/rail.h>
 #include <guacamole/audio.h>
 #include <guacamole/client.h>
 #include <guacamole/recording.h>
@@ -196,6 +197,12 @@ typedef struct guac_rdp_client {
      */
     pthread_mutex_t message_lock;
 
+    /**
+     * A pointer to the RAIL interface provided by the RDP client when rail is
+     * in use.
+     */
+    RailClientContext* rail_interface;
+
 } guac_rdp_client;
 
 /**