Rename client_info hostname to client_name

This name better matches the name from [MS-RDPBCGR]. Also, the size
of the UTF-8 buffer allocated for the client name is not large
enough for some of the names which could potentially be passed across
in UTF-16 from the client.

common/xrdp_client_info.h

@@ -146,7 +146,7 @@ struct xrdp_client_info
     int op2; /* use smaller bitmap header in bitmap cache */
     int desktop_cache;
     int use_compact_packets; /* rdp5 smaller packets */
-    char hostname[32];
+    char client_name[INFO_CLIENT_NAME_BYTES_UTF8];
     int build;
     int keylayout;
     char username[INFO_CLIENT_MAX_CB_LEN];

common/xrdp_constants.h

@@ -51,8 +51,20 @@
  */
 #define MAX_PEER_DESCSTRLEN (46 + 2 + 1 + 5)
 
-#define INFO_CLIENT_NAME_BYTES  32
+/*
+ * Number of bytes used to send a client name in the client core data
+ * ([MS-RDPBCGR] 2.2.1.3.2). This is 15 characters plus a terminator in
+ * UTF-16
+ */
+#define INFO_CLIENT_NAME_BYTES_UTF16  ((15 + 1) * 2)
 
+/*
+ * Number of bytes needed to store the client name as UTF-8. It is assumed
+ * that the 15 Unicode characters in the name all occupy BMP codepoints
+ * between U+0800 and U+FFFF. These codepoints all need three octets
+ * in UTF-8
+ */
+#define INFO_CLIENT_NAME_BYTES_UTF8 ((3 * 15) + 1)
 /**
  * Maximum length of a string including the mandatory null terminator
  * [MS-RDPBCGR] TS_INFO_PACKET(2.2.1.11.1.1)