Unify monitor processing logic.

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

- TS_UD_CS_MONITOR ([MS-RDPBCGR] 2.2.1.3.6 Client Monitor Data)
- DISPLAYCONTROL_PDU_TYPE_MONITOR_LAYOUT ([MS-RDPEDISP] 2.2.2.2)

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.

Also a large number of clarifications for the constants and protocol
requirements.

Note that this is also the first step to making resizing work with the extension GFX channel as well as an important
foundational step to enable HiDPI compatibility.

Also some misc logging updates.

3 files changed, 55 insertions, 4 deletions

diff --git a/common/ms-rdpbcgr.h b/common/ms-rdpbcgr.h
index 813dc4db..e993c270 100644
--- a/common/ms-rdpbcgr.h
+++ b/common/ms-rdpbcgr.h
@@ -83,10 +83,24 @@
 #define RDPSND_SVC_CHANNEL_NAME         "rdpsnd"
 #define RDPDR_SVC_CHANNEL_NAME          "rdpdr"
 
-/* 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
+#define CLIENT_MONITOR_DATA_MINIMUM_VIRTUAL_DESKTOP_HEIGHT 0xC8
+#define CLIENT_MONITOR_DATA_MAXIMUM_VIRTUAL_DESKTOP_WIDTH  0x7FFE
+#define CLIENT_MONITOR_DATA_MAXIMUM_VIRTUAL_DESKTOP_HEIGHT 0x7FFE
+
+/* 2.2.1.3.6.1 Monitor Definition (TS_MONITOR_DEF) */
+#define TS_MONITOR_PRIMARY 0x00000001
 
 /* Options field */
 /* NOTE: XR_ prefixed to avoid conflict with FreeRDP */
diff --git a/common/ms-rdpedisp.h b/common/ms-rdpedisp.h
index dd3d51e7..2e45b945 100644
--- a/common/ms-rdpedisp.h
+++ b/common/ms-rdpedisp.h
@@ -23,7 +23,19 @@
 #define MS_RDPEDISP_H
 
 /* Display Control Messages: Display Virtual Channel Extension (2.2.2) */
-#define DISPLAYCONTROL_PDU_TYPE_MONITOR_LAYOUT 0x00000002
-#define DISPLAYCONTROL_PDU_TYPE_CAPS           0x00000005
+#define DISPLAYCONTROL_PDU_TYPE_MONITOR_LAYOUT             0x00000002
+#define DISPLAYCONTROL_PDU_TYPE_CAPS                       0x00000005
+
+/* Display Control Monitor Layout (2.2.2.2.1) */
+#define DISPLAYCONTROL_MONITOR_PRIMARY                     0x00000001
+#define CLIENT_MONITOR_DATA_MINIMUM_VIRTUAL_MONITOR_WIDTH  0xC8
+#define CLIENT_MONITOR_DATA_MINIMUM_VIRTUAL_MONITOR_HEIGHT 0xC8
+#define CLIENT_MONITOR_DATA_MAXIMUM_VIRTUAL_MONITOR_WIDTH  0x2000
+#define CLIENT_MONITOR_DATA_MAXIMUM_VIRTUAL_MONITOR_HEIGHT 0x2000
+
+#define ORIENTATION_LANDSCAPE                              0
+#define ORIENTATION_PORTRAIT                               90
+#define ORIENTATION_LANDSCAPE_FLIPPED                      180
+#define ORIENTATION_PORTRAIT_FLIPPED                       270
 
 #endif /* MS_RDPEDISP_H */
diff --git a/common/xrdp_client_info.h b/common/xrdp_client_info.h
index f45195e8..106e47a7 100644
--- a/common/xrdp_client_info.h
+++ b/common/xrdp_client_info.h
@@ -24,12 +24,28 @@
 #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 physical_width;
+    int physical_height;
+    int orientation;
+    int desktop_scale_factor;
+    int device_scale_factor;
+
+    /* Derived setting */
     int is_primary;
 };
 
@@ -41,6 +57,15 @@ struct xrdp_keyboard_overrides
     int layout;
 };
 
+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
  *