GUACAMOLE-962: Merge allow misbehaving RDP servers to use OpaqueRect and PatBlt.

configure.ac

@@ -722,6 +722,21 @@ then
 
 fi
 
+# Support for receiving unannounced orders from the RDP server
+if test "x${have_freerdp2}" = "xyes"
+then
+    AC_CHECK_MEMBERS([rdpSettings.AllowUnanouncedOrdersFromServer],,
+                     [AC_MSG_WARN([
+  --------------------------------------------
+   This version of FreeRDP does not support relaxed order checks. RDP servers
+   that send orders that the client did not announce as supported (such as the
+   VirtualBox RDP server) will likely not be usable.
+
+   See: https://issues.apache.org/jira/browse/GUACAMOLE-962
+  --------------------------------------------])],
+                     [[#include <freerdp/freerdp.h>]])
+fi
+
 # Restore CPPFLAGS, removing FreeRDP-specific options needed for testing
 CPPFLAGS="$OLDCPPFLAGS"
 

src/protocols/rdp/gdi.c

@@ -18,6 +18,7 @@
  */
 
 #include "bitmap.h"
+#include "color.h"
 #include "common/display.h"
 #include "common/surface.h"
 #include "rdp.h"
@@ -139,6 +140,76 @@ BOOL guac_rdp_gdi_dstblt(rdpContext* context, const DSTBLT_ORDER* dstblt) {
 
 }
 
+BOOL guac_rdp_gdi_patblt(rdpContext* context, PATBLT_ORDER* patblt) {
+
+    /*
+     * Note that this is not a full implementation of PATBLT. This is a
+     * fallback implementation which only renders a solid block of background
+     * color using the specified ROP3 operation, ignoring whatever brush
+     * was actually specified.
+     *
+     * As libguac-client-rdp explicitly tells the server not to send PATBLT,
+     * well-behaved RDP servers will not use this operation at all, while
+     * others will at least have a fallback.
+     */
+
+    /* Get client and current layer */
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_common_surface* current_surface =
+        ((guac_rdp_client*) client->data)->current_surface;
+
+    int x = patblt->nLeftRect;
+    int y = patblt->nTopRect;
+    int w = patblt->nWidth;
+    int h = patblt->nHeight;
+
+    /*
+     * Warn that rendering is a fallback, as the server should not be sending
+     * this order.
+     */
+    guac_client_log(client, GUAC_LOG_INFO, "Using fallback PATBLT (server is ignoring "
+            "negotiated client capabilities)");
+
+    /* Render rectangle based on ROP */
+    switch (patblt->bRop) {
+
+        /* If blackness, send black rectangle */
+        case 0x00:
+            guac_common_surface_set(current_surface, x, y, w, h,
+                    0x00, 0x00, 0x00, 0xFF);
+            break;
+
+        /* If NOP, do nothing */
+        case 0xAA:
+            break;
+
+        /* If operation is just a copy, send foreground only */
+        case 0xCC:
+        case 0xF0:
+            guac_common_surface_set(current_surface, x, y, w, h,
+                    (patblt->foreColor >> 16) & 0xFF,
+                    (patblt->foreColor >> 8 ) & 0xFF,
+                    (patblt->foreColor      ) & 0xFF,
+                    0xFF);
+            break;
+
+        /* If whiteness, send white rectangle */
+        case 0xFF:
+            guac_common_surface_set(current_surface, x, y, w, h,
+                    0xFF, 0xFF, 0xFF, 0xFF);
+            break;
+
+        /* Otherwise, invert entire rect */
+        default:
+            guac_common_surface_transfer(current_surface, x, y, w, h,
+                                         GUAC_TRANSFER_BINARY_NDEST, current_surface, x, y);
+
+    }
+
+    return TRUE;
+
+}
+
 BOOL guac_rdp_gdi_scrblt(rdpContext* context, const SCRBLT_ORDER* scrblt) {
 
     guac_client* client = ((rdp_freerdp_context*) context)->client;
@@ -256,6 +327,30 @@ BOOL guac_rdp_gdi_memblt(rdpContext* context, MEMBLT_ORDER* memblt) {
 
 }
 
+BOOL guac_rdp_gdi_opaquerect(rdpContext* context, const OPAQUE_RECT_ORDER* opaque_rect) {
+
+    /* Get client data */
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+
+    UINT32 color = guac_rdp_convert_color(context, opaque_rect->color);
+
+    guac_common_surface* current_surface = ((guac_rdp_client*) client->data)->current_surface;
+
+    int x = opaque_rect->nLeftRect;
+    int y = opaque_rect->nTopRect;
+    int w = opaque_rect->nWidth;
+    int h = opaque_rect->nHeight;
+
+    guac_common_surface_set(current_surface, x, y, w, h,
+            (color >> 16) & 0xFF,
+            (color >> 8 ) & 0xFF,
+            (color      ) & 0xFF,
+            0xFF);
+
+    return TRUE;
+
+}
+
 BOOL guac_rdp_gdi_set_bounds(rdpContext* context, const rdpBounds* bounds) {
 
     guac_client* client = ((rdp_freerdp_context*) context)->client;

src/protocols/rdp/gdi.h

@@ -62,6 +62,25 @@ guac_composite_mode guac_rdp_rop3_transfer_function(guac_client* client,
  */
 BOOL guac_rdp_gdi_dstblt(rdpContext* context, const DSTBLT_ORDER* dstblt);
 
+/**
+ * Handler for the PatBlt Primary Drawing Order. A PatBlt Primary Drawing Order
+ * paints a rectangle of image data, a brush pattern, and a three-way raster
+ * operation which considers the source data, the destination, AND the brush
+ * pattern. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpegdi/bd4bf5e7-b988-45f9-8201-3b22cc9aeeb8
+ *
+ * @param context
+ *     The rdpContext associated with the current RDP session.
+ *
+ * @param patblt
+ *     The PATBLT update to handle.
+ *
+ * @return
+ *     TRUE if successful, FALSE otherwise.
+ */
+BOOL guac_rdp_gdi_patblt(rdpContext* context, PATBLT_ORDER* patblt);
+
 /**
  * Handler for the ScrBlt Primary Drawing Order. A ScrBlt Primary Drawing Order
  * paints a rectangle of image data using a raster operation which considers
@@ -98,6 +117,26 @@ BOOL guac_rdp_gdi_scrblt(rdpContext* context, const SCRBLT_ORDER* scrblt);
  */
 BOOL guac_rdp_gdi_memblt(rdpContext* context, MEMBLT_ORDER* memblt);
 
+/**
+ * Handler for the OpaqueRect Primary Drawing Order. An OpaqueRect Primary
+ * Drawing Order draws an opaque rectangle of a single solid color. Note that
+ * support for OpaqueRect cannot be claimed without also supporting PatBlt, as
+ * both use the same negotiation order number. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpegdi/1eead7aa-ac63-411a-9f8c-b1b227526877
+ *
+ * @param context
+ *     The rdpContext associated with the current RDP session.
+ *
+ * @param opaque_rect
+ *     The OPAQUE RECT update to handle.
+ *
+ * @return
+ *     TRUE if successful, FALSE otherwise.
+ */
+BOOL guac_rdp_gdi_opaquerect(rdpContext* context,
+        const OPAQUE_RECT_ORDER* opaque_rect);
+
 /**
  * Handler called prior to calling the handlers for specific updates when
  * those updates are clipped by a bounding rectangle. This is not a true RDP

src/protocols/rdp/rdp.c

@@ -179,8 +179,10 @@ BOOL rdp_freerdp_pre_connect(freerdp* instance) {
 
     rdpPrimaryUpdate* primary = instance->update->primary;
     primary->DstBlt = guac_rdp_gdi_dstblt;
+    primary->PatBlt = guac_rdp_gdi_patblt;
     primary->ScrBlt = guac_rdp_gdi_scrblt;
     primary->MemBlt = guac_rdp_gdi_memblt;
+    primary->OpaqueRect = guac_rdp_gdi_opaquerect;
 
     pointer_cache_register_callbacks(instance->update);
     glyph_cache_register_callbacks(instance->update);

src/protocols/rdp/settings.c

@@ -1356,5 +1356,10 @@ void guac_rdp_push_settings(guac_client* client,
     rdp_settings->OrderSupport[NEG_FAST_INDEX_INDEX] = !guac_settings->disable_glyph_caching;
     rdp_settings->OrderSupport[NEG_FAST_GLYPH_INDEX] = !guac_settings->disable_glyph_caching;
 
+#ifdef HAVE_RDPSETTINGS_ALLOWUNANOUNCEDORDERSFROMSERVER
+    /* Do not consider server use of unannounced orders to be a fatal error */
+    rdp_settings->AllowUnanouncedOrdersFromServer = TRUE;
+#endif
+
 }