GUACAMOLE-1196: Implement support for VNC display size updates

src/common/common/display.h

@@ -28,6 +28,22 @@
 
 #include <pthread.h>
 
+/**
+ * The minimum display size (height or width) in pixels.
+ */
+#define GUAC_COMMON_DISPLAY_MIN_SIZE 200
+
+/**
+ * The maximum display size (height or width) in pixels.
+ */
+#define GUAC_COMMON_DISPLAY_MAX_SIZE 8192
+
+/**
+ * The minimum amount of time that must elapse between display size updates,
+ * in milliseconds.
+ */
+#define GUAC_COMMON_DISPLAY_UPDATE_INTERVAL 500
+
 /**
  * A list element representing a pairing of a Guacamole layer with a
  * corresponding guac_common_surface which wraps that layer. Adjacent layers
@@ -135,6 +151,19 @@ typedef struct guac_common_display {
 guac_common_display* guac_common_display_alloc(guac_client* client,
         int width, int height);
 
+/**
+ * Fits a given dimension within the allowed bounds for display sizing,
+ * adjusting the other dimension such that aspect ratio is maintained.
+ *
+ * @param a
+ *     The dimension to fit within allowed bounds.
+ *
+ * @param b
+ *     The other dimension to adjust if and only if necessary to preserve
+ *     aspect ratio.
+ */
+void guac_common_display_fit(int* a, int* b);
+
 /**
  * Frees the given display, and any associated resources, including any
  * allocated buffers/layers.
@@ -258,5 +287,7 @@ void guac_common_display_free_buffer(guac_common_display* display,
 void guac_common_display_set_lossless(guac_common_display* display,
         int lossless);
 
+
+
 #endif
 

src/common/display.c

@@ -187,6 +187,37 @@ void guac_common_display_dup(
 
 }
 
+void guac_common_display_fit(int* a, int* b) {
+
+    int a_value = *a;
+    int b_value = *b;
+
+    /* Ensure first dimension is within allowed range */
+    if (a_value < GUAC_COMMON_DISPLAY_MIN_SIZE) {
+
+        /* Adjust other dimension to maintain aspect ratio */
+        int adjusted_b = b_value * GUAC_COMMON_DISPLAY_MIN_SIZE / a_value;
+        if (adjusted_b > GUAC_COMMON_DISPLAY_MAX_SIZE)
+            adjusted_b = GUAC_COMMON_DISPLAY_MAX_SIZE;
+
+        *a = GUAC_COMMON_DISPLAY_MIN_SIZE;
+        *b = adjusted_b;
+
+    }
+    else if (a_value > GUAC_COMMON_DISPLAY_MAX_SIZE) {
+
+        /* Adjust other dimension to maintain aspect ratio */
+        int adjusted_b = b_value * GUAC_COMMON_DISPLAY_MAX_SIZE / a_value;
+        if (adjusted_b < GUAC_COMMON_DISPLAY_MIN_SIZE)
+            adjusted_b = GUAC_COMMON_DISPLAY_MIN_SIZE;
+
+        *a = GUAC_COMMON_DISPLAY_MAX_SIZE;
+        *b = adjusted_b;
+
+    }
+
+}
+
 void guac_common_display_set_lossless(guac_common_display* display,
         int lossless) {
 

src/protocols/rdp/channels/disp.c

@@ -18,6 +18,7 @@
  */
 
 #include "channels/disp.h"
+#include "common/display.h"
 #include "plugins/channels.h"
 #include "fs.h"
 #include "rdp.h"
@@ -149,56 +150,14 @@ void guac_rdp_disp_load_plugin(rdpContext* context) {
 
 }
 
-/**
- * Fits a given dimension within the allowed bounds for Display Update
- * messages, adjusting the other dimension such that aspect ratio is
- * maintained.
- *
- * @param a The dimension to fit within allowed bounds.
- *
- * @param b
- *     The other dimension to adjust if and only if necessary to preserve
- *     aspect ratio.
- */
-static void guac_rdp_disp_fit(int* a, int* b) {
-
-    int a_value = *a;
-    int b_value = *b;
-
-    /* Ensure first dimension is within allowed range */
-    if (a_value < GUAC_RDP_DISP_MIN_SIZE) {
-
-        /* Adjust other dimension to maintain aspect ratio */
-        int adjusted_b = b_value * GUAC_RDP_DISP_MIN_SIZE / a_value;
-        if (adjusted_b > GUAC_RDP_DISP_MAX_SIZE)
-            adjusted_b = GUAC_RDP_DISP_MAX_SIZE;
-
-        *a = GUAC_RDP_DISP_MIN_SIZE;
-        *b = adjusted_b;
-
-    }
-    else if (a_value > GUAC_RDP_DISP_MAX_SIZE) {
-
-        /* Adjust other dimension to maintain aspect ratio */
-        int adjusted_b = b_value * GUAC_RDP_DISP_MAX_SIZE / a_value;
-        if (adjusted_b < GUAC_RDP_DISP_MIN_SIZE)
-            adjusted_b = GUAC_RDP_DISP_MIN_SIZE;
-
-        *a = GUAC_RDP_DISP_MAX_SIZE;
-        *b = adjusted_b;
-
-    }
-
-}
-
 void guac_rdp_disp_set_size(guac_rdp_disp* disp, guac_rdp_settings* settings,
         freerdp* rdp_inst, int width, int height) {
 
     /* Fit width within bounds, adjusting height to maintain aspect ratio */
-    guac_rdp_disp_fit(&width, &height);
+    guac_common_display_fit(&width, &height);
 
     /* Fit height within bounds, adjusting width to maintain aspect ratio */
-    guac_rdp_disp_fit(&height, &width);
+    guac_common_display_fit(&height, &width);
 
     /* Width must be even */
     if (width % 2 == 1)
@@ -226,7 +185,7 @@ void guac_rdp_disp_update_size(guac_rdp_disp* disp,
     guac_timestamp now = guac_timestamp_current();
 
     /* Limit display update frequency */
-    if (now - disp->last_request <= GUAC_RDP_DISP_UPDATE_INTERVAL)
+    if (now - disp->last_request <= GUAC_COMMON_DISPLAY_UPDATE_INTERVAL)
         return;
 
     /* Do NOT send requests unless the size will change */

src/protocols/rdp/channels/disp.h

@@ -27,22 +27,6 @@
 #include <guacamole/client.h>
 #include <guacamole/timestamp.h>
 
-/**
- * The minimum value for width or height, in pixels.
- */
-#define GUAC_RDP_DISP_MIN_SIZE 200
-
-/**
- * The maximum value for width or height, in pixels.
- */
-#define GUAC_RDP_DISP_MAX_SIZE 8192
-
-/**
- * The minimum amount of time that must elapse between display size updates,
- * in milliseconds.
- */
-#define GUAC_RDP_DISP_UPDATE_INTERVAL 500
-
 /**
  * Display size update module.
  */

src/protocols/vnc/client.c

@@ -111,6 +111,9 @@ int guac_client_init(guac_client* client) {
     pthread_mutex_init(&vnc_client->tls_lock, NULL);
 #endif
 
+    /* Initialize the message lock. */
+    pthread_mutex_init(&(vnc_client->message_lock), NULL);
+
     /* Init clipboard */
     vnc_client->clipboard = guac_common_clipboard_alloc();
 
@@ -209,6 +212,9 @@ int guac_vnc_client_free_handler(guac_client* client) {
     pthread_mutex_destroy(&(vnc_client->tls_lock));
 #endif
 
+    /* Clean up the message lock. */
+    pthread_mutex_destroy(&(vnc_client->message_lock));
+
     /* Free generic data struct */
     guac_mem_free(client->data);
 

src/protocols/vnc/display.c

@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include "client.h"
+#include "display.h"
 #include "common/iconv.h"
 #include "common/surface.h"
 #include "vnc.h"
@@ -30,6 +31,7 @@
 #include <guacamole/mem.h>
 #include <guacamole/protocol.h>
 #include <guacamole/socket.h>
+#include <guacamole/timestamp.h>
 #include <rfb/rfbclient.h>
 #include <rfb/rfbproto.h>
 
@@ -153,6 +155,140 @@ void guac_vnc_copyrect(rfbClient* client, int src_x, int src_y, int w, int h, in
 
 }
 
+/**
+ * This function does the actual work of sending the message to the RFB/VNC
+ * server to request the resize, and then makes sure that the client frame
+ * buffer is updated, as well.
+ *
+ * @param client
+ *     The remote frame buffer client that is triggering the resize
+ *     request.
+ *
+ * @param width
+ *     The updated width of the screen.
+ *
+ * @param height
+ *     The updated height of the screen.
+ *
+ * @return
+ *     TRUE if the screen update was sent to the server, otherwise false. Note
+ *     that a successful send of the resize message to the server does NOT mean
+ *     that the server has any obligation to resize the display - it only
+ *     indicates that the VNC library has successfully sent the request.
+ */
+static rfbBool guac_vnc_send_desktop_size(rfbClient* client, int width, int height) {
+
+    /* Get the Guacamole client data */
+    guac_client* gc = rfbClientGetClientData(client, GUAC_VNC_CLIENT_KEY);
+
+    /* Don't send an update if the sreen appears to be uninitialized. */
+    if (client->screen.width == 0 || client->screen.height == 0) {
+        guac_client_log(gc, GUAC_LOG_ERROR, "Screen has not been initialized, cannot send resize.");
+        return FALSE;
+    }
+
+    /* Don't send an update if the requested dimensions are identical to current dimensions. */
+    if (client->screen.width == rfbClientSwap16IfLE(width) && client->screen.height == rfbClientSwap16IfLE(height)) {
+        guac_client_log(gc, GUAC_LOG_WARNING, "Screen size has not changed, not sending update.");
+        return FALSE;
+    }
+
+    /**
+     * Note: The RFB protocol requires two message types to be sent during a
+     * resize request - the first for the desktop size (total size of all
+     * monitors), and then a message for each screen that is attached to the 
+     * remote server. Both libvncclient and Guacamole only support a single
+     * screen, so we send the desktop resize and screen resize with (nearly)
+     * identical data, but if one or both of these components is updated in the
+     * future to support multiple screens, this will need to be re-worked.
+     */
+
+    /* Set up the messages. */
+    rfbSetDesktopSizeMsg size_msg;
+    rfbExtDesktopScreen new_screen;
+
+    /* Configure the desktop size update message. */
+    size_msg.type = rfbSetDesktopSize;
+    size_msg.width = rfbClientSwap16IfLE(width);
+    size_msg.height = rfbClientSwap16IfLE(height);
+    size_msg.numberOfScreens = 1;
+
+    /* Configure the screen update message. */
+    new_screen.id = client->screen.id;
+    new_screen.x = client->screen.x;
+    new_screen.y = client->screen.y;
+    new_screen.flags = client->screen.flags;
+    new_screen.width = rfbClientSwap16IfLE(width);
+    new_screen.height = rfbClientSwap16IfLE(height);
+
+    /* Stop updates while the resize is in progress. */
+    client->requestedResize = TRUE;
+
+    /* Send the resize messages to the remote server. */
+    if (!WriteToRFBServer(client, (char *)&size_msg, sz_rfbSetDesktopSizeMsg)
+        || !WriteToRFBServer(client, (char *)&new_screen, sz_rfbExtDesktopScreen)) {
+
+        guac_client_log(gc, GUAC_LOG_ERROR, "Failed to send new desktop and screen size to the VNC server.");
+        return FALSE;
+
+    }
+
+    /* Update the client frame buffer with the requested size. */
+    client->screen.width = rfbClientSwap16IfLE(width);
+    client->screen.height = rfbClientSwap16IfLE(height);
+
+    /* Request a full screen update. */
+    client->requestedResize = FALSE;
+    if (!SendFramebufferUpdateRequest(client, 0, 0, width, height, FALSE)) {
+        guac_client_log(gc, GUAC_LOG_WARNING, "Failed to request a full screen update.");
+    }
+
+    /* Update should be successful. */
+    return TRUE;
+}
+
+void* guac_vnc_display_set_owner_size(guac_user* owner, void* data) {
+
+    /* Pull RFB clients from provided data. */
+    rfbClient* rfb_client = (rfbClient*) data;
+
+    guac_user_log(owner, GUAC_LOG_DEBUG, "Sending VNC display size for owner's display.");
+
+    /* Set the display size. */
+    guac_vnc_display_set_size(rfb_client, owner->info.optimal_width, owner->info.optimal_height);
+
+    /* Always return NULL. */
+    return NULL;
+
+}
+
+void guac_vnc_display_set_size(rfbClient* client, int width, int height) {
+
+    /* Get the VNC client */
+    guac_client* gc = rfbClientGetClientData(client, GUAC_VNC_CLIENT_KEY);
+    guac_vnc_client* vnc_client = (guac_vnc_client*) gc->data;
+
+    /* Fit width within bounds, adjusting height to maintain aspect ratio */
+    guac_common_display_fit(&width, &height);
+
+    /* Fit height within bounds, adjusting width to maintain aspect ratio */
+    guac_common_display_fit(&height, &width);
+
+    /* Acquire the lock for sending messages to server. */
+    pthread_mutex_lock(&(vnc_client->message_lock));
+
+    /* Send the display size update. */
+    guac_client_log(gc, GUAC_LOG_TRACE, "Setting VNC display size.");
+    if (guac_vnc_send_desktop_size(client, width, height))
+        guac_client_log(gc, GUAC_LOG_TRACE, "Successfully sent desktop size message.");
+    else
+        guac_client_log(gc, GUAC_LOG_TRACE, "Failed to send desktop size message.");
+
+    /* Release the lock. */
+    pthread_mutex_unlock(&(vnc_client->message_lock));
+
+}
+
 void guac_vnc_set_pixel_format(rfbClient* client, int color_depth) {
     client->format.trueColour = 1;
     switch(color_depth) {
@@ -205,4 +341,3 @@ rfbBool guac_vnc_malloc_framebuffer(rfbClient* rfb_client) {
     /* Use original, wrapped proc */
     return vnc_client->rfb_MallocFrameBuffer(rfb_client);
 }
-