Unify monitor processing logic.

There are two places where monitor descriptions are passed through the
RDP protocol:

- TS_UD_CS_MONITOR
- DISPLAYCONTROL_PDU_TYPE_MONITOR_LAYOUT

The processing logic for both of them is similar enough that they should
be unified.

Also update to define the constants for the maximum and minimum desktop width/height for monitors and total area.

Note that this is also the first step to making resizing work with the extension GFX channel.

Also some misc logging updates.

common/ms-rdpbcgr.h

@@ -78,10 +78,21 @@
 /* This isn't explicitly named in MS-RDPBCGR */
 #define CHANNEL_NAME_LEN                7
 
-/* 2.2.1.3.6 Client Monitor Data - */
+/* 2.2.1.3.6 Client Monitor Data */
 /* monitorCount (4 bytes): A 32-bit, unsigned integer. The number of display */
 /* monitor definitions in the monitorDefArray field (the maximum allowed is 16). */
-#define CLIENT_MONITOR_DATA_MAXIMUM_MONITORS 16
+#define CLIENT_MONITOR_DATA_MAXIMUM_MONITORS               16
+
+/* 2.2.1.3.6 Client Monitor Data */
+/* The maximum width of the virtual desktop resulting from the union of the monitors */
+/* contained in the monitorDefArray field MUST NOT exceed 32,766 pixels. Similarly, */
+/* the maximum height of the virtual desktop resulting from the union of the monitors  */
+/* contained in the monitorDefArray field MUST NOT exceed 32,766 pixels. */
+/* The minimum permitted size of the virtual desktop is 200 x 200 pixels. */
+#define CLIENT_MONITOR_DATA_MINIMUM_VIRTUAL_DESKTOP_WIDTH  0xC8   // 200
+#define CLIENT_MONITOR_DATA_MINIMUM_VIRTUAL_DESKTOP_HEIGHT 0xC8   // 200
+#define CLIENT_MONITOR_DATA_MAXIMUM_VIRTUAL_DESKTOP_WIDTH  0x7FFE // 32766
+#define CLIENT_MONITOR_DATA_MAXIMUM_VIRTUAL_DESKTOP_HEIGHT 0x7FFE // 32766
 
 /* Options field */
 /* NOTE: XR_ prefixed to avoid conflict with FreeRDP */

common/xrdp_client_info.h

@@ -24,15 +24,42 @@
 #if !defined(XRDP_CLIENT_INFO_H)
 #define XRDP_CLIENT_INFO_H
 
+/*
+ * 2.2.1.3.6.1 Monitor Definition (TS_MONITOR_DEF)
+ * 2.2.1.3.9.1 Monitor Attributes (TS_MONITOR_ATTRIBUTES)
+ * 2.2.2.2.1 DISPLAYCONTROL_MONITOR_LAYOUT
+ */
 struct monitor_info
 {
+    /* From 2.2.1.3.6.1 Monitor Definition (TS_MONITOR_DEF) */
     int left;
     int top;
     int right;
     int bottom;
+    int flags;
+
+    /* From 2.2.2.2.1 DISPLAYCONTROL_MONITOR_LAYOUT */
+    int width;
+    int height;
+    int physical_width;
+    int physical_height;
+    int orientation;
+    int desktop_scale_factor;
+    int device_scale_factor;
+
+    /* Derived setting */
     int is_primary;
 };
 
+struct display_size_description
+{
+    int monitorCount; /* number of monitors detected (max = 16) */
+    struct monitor_info minfo[CLIENT_MONITOR_DATA_MAXIMUM_MONITORS]; /* client monitor data */
+    struct monitor_info minfo_wm[CLIENT_MONITOR_DATA_MAXIMUM_MONITORS]; /* client monitor data, non-negative values */
+    int session_width;
+    int session_height;
+};
+
 /**
  * Information about the xrdp client
  *