GUAC-1164: Add setting for specifying the resize method, if any.

src/protocols/rdp/rdp.c

@@ -170,15 +170,17 @@ static int __guac_receive_channel_data(freerdp* rdp_inst, int channelId,
 static void guac_rdp_channel_connected(rdpContext* context,
         ChannelConnectedEventArgs* e) {
 
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+    guac_rdp_settings* settings = rdp_client->settings;
+
+    if (settings->resize_method == GUAC_RESIZE_DISPLAY_UPDATE) {
 #ifdef HAVE_RDPSETTINGS_SUPPORTDISPLAYCONTROL
         /* Store reference to the display update plugin once it's connected */
         if (strcmp(e->name, DISP_DVC_CHANNEL_NAME) == 0) {
 
             DispClientContext* disp = (DispClientContext*) e->pInterface;
 
-        guac_client* client = ((rdp_freerdp_context*) context)->client;
-        guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
-
             /* Init module with current display size */
             guac_rdp_disp_set_size(rdp_client->disp, rdp_client->settings,
                     context->instance, guac_rdp_get_width(context->instance),
@@ -191,6 +193,7 @@ static void guac_rdp_channel_connected(rdpContext* context,
 
         }
 #endif
+    }
 
 }
 #endif

src/protocols/rdp/rdp_disp.c

@@ -169,19 +169,18 @@ void guac_rdp_disp_update_size(guac_rdp_disp* disp,
 
     disp->last_request = now;
 
-    if (1) {
+    if (settings->resize_method == GUAC_RESIZE_RECONNECT) {
+
         /* Update settings with new dimensions */
         settings->width = width;
         settings->height = height;
 
         /* Signal reconnect */
         disp->reconnect_needed = 1;
-#ifdef HAVE_FREERDP_DISPLAY_UPDATE_SUPPORT
-        disp->disp = NULL;
-#endif
-        return;
+
     }
 
+    else if (settings->resize_method == GUAC_RESIZE_DISPLAY_UPDATE) {
 #ifdef HAVE_FREERDP_DISPLAY_UPDATE_SUPPORT
         DISPLAY_CONTROL_MONITOR_LAYOUT monitors[1] = {{
             .Flags  = 0x1, /* DISPLAYCONTROL_MONITOR_PRIMARY */
@@ -200,6 +199,7 @@ void guac_rdp_disp_update_size(guac_rdp_disp* disp,
         if (disp->disp != NULL)
             disp->disp->SendMonitorLayout(disp->disp, 1, monitors);
 #endif
+    }
 
 }
 

src/protocols/rdp/rdp_settings.c

@@ -92,6 +92,7 @@ const char* GUAC_RDP_CLIENT_ARGS[] = {
     "recording-path",
     "recording-name",
     "create-recording-path",
+    "resize-method",
 
     NULL
 };
@@ -360,6 +361,12 @@ enum RDP_ARGS_IDX {
     IDX_RECORDING_NAME,
     IDX_CREATE_RECORDING_PATH,
 
+    /**
+     * The method to use to apply screen size changes requested by the user.
+     * Valid values are blank, "display-update", and "reconnect".
+     */
+    IDX_RESIZE_METHOD,
+
     RDP_ARGS_COUNT
 };
 
@@ -696,6 +703,31 @@ guac_rdp_settings* guac_rdp_parse_args(guac_user* user,
         guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,
                 IDX_CREATE_RECORDING_PATH, 0);
 
+    /* No resize method */
+    if (strcmp(argv[IDX_RESIZE_METHOD], "") == 0) {
+        guac_user_log(user, GUAC_LOG_INFO, "Resize method: none");
+        settings->resize_method = GUAC_RESIZE_NONE;
+    }
+
+    /* Resize method: "reconnect" */
+    else if (strcmp(argv[IDX_RESIZE_METHOD], "reconnect") == 0) {
+        guac_user_log(user, GUAC_LOG_INFO, "Resize method: reconnect");
+        settings->resize_method = GUAC_RESIZE_RECONNECT;
+    }
+
+    /* Resize method: "display-update" */
+    else if (strcmp(argv[IDX_RESIZE_METHOD], "display-update") == 0) {
+        guac_user_log(user, GUAC_LOG_INFO, "Resize method: display-update");
+        settings->resize_method = GUAC_RESIZE_DISPLAY_UPDATE;
+    }
+
+    /* Default to no resize method if invalid */
+    else {
+        guac_user_log(user, GUAC_LOG_INFO, "Resize method \"%s\" invalid. ",
+                "Defaulting to no resize method.", argv[IDX_RESIZE_METHOD]);
+        settings->resize_method = GUAC_RESIZE_NONE;
+    }
+
     /* Success */
     return settings;
 

src/protocols/rdp/rdp_settings.h

@@ -88,6 +88,32 @@ typedef enum guac_rdp_security {
 
 } guac_rdp_security;
 
+/**
+ * All supported combinations screen resize methods.
+ */
+typedef enum guac_rdp_resize_method {
+
+    /**
+     * Dynamic resizing of the display will not be attempted.
+     */
+    GUAC_RESIZE_NONE,
+
+    /**
+     * Dynamic resizing will be attempted through sending requests along the
+     * Display Update channel. This will only work with recent versions of
+     * Windows and relatively-recent versions of FreeRDP.
+     */
+    GUAC_RESIZE_DISPLAY_UPDATE,
+
+    /**
+     * Guacamole will automatically disconnect and reconnect to the RDP server
+     * whenever the screen size changes, requesting the new size during
+     * reconnect.
+     */
+    GUAC_RESIZE_RECONNECT
+
+} guac_rdp_resize_method;
+
 /**
  * All settings supported by the Guacamole RDP client.
  */
@@ -350,6 +376,11 @@ typedef struct guac_rdp_settings {
      */
     int create_recording_path;
 
+    /**
+     * The method to apply when the user's display changes size.
+     */
+    guac_rdp_resize_method resize_method;
+
 } guac_rdp_settings;
 
 /**