2.2.8.1.1.1.2 Share Data Header (TS_SHAREDATAHEADER)

The TS_SHAREDATAHEADER header is a T.128 header ([T128] section 8.3) that MUST be present in all Data PDUs. A definitive list of all Data PDUs is given in the description of the pduType2 field.

shareControlHeader (6 bytes): Share Control Header (section 2.2.8.1.1.1.1) containing information about the packet. The PDUVersion subfield of the pduType field of the Share Control Header MUST be set to TS_PROTOCOL_VERSION (0x1).

shareID (4 bytes): A 32-bit, unsigned integer. Share identifier for the packet (see [T128] section 8.4.2 for more information about share IDs).

pad1 (1 byte): An 8-bit, unsigned integer. Padding. Values in this field MUST be ignored.

streamID (1 byte): An 8-bit, unsigned integer. The stream identifier for the packet.

Value	Meaning
STREAM_UNDEFINED 0x00	Undefined stream priority. This value might be used in the Server Synchronize PDU (section 2.2.1.19) due to a server-side RDP bug. It MUST NOT be used in conjunction with any other PDUs.
STREAM_LOW 0x01	Low-priority stream.
STREAM_MED 0x02	Medium-priority stream.
STREAM_HI 0x04	High-priority stream.

uncompressedLength (2 bytes): A 16-bit, unsigned integer. The uncompressed length of the packet in bytes.

pduType2 (1 byte): An 8-bit, unsigned integer. The type of Data PDU.

Value	Meaning
PDUTYPE2_UPDATE 0x02	Graphics Update PDU (section 2.2.9.1.1.3)
PDUTYPE2_CONTROL 0x14	Control PDU (section 2.2.1.15.1)
PDUTYPE2_POINTER 0x1B	Pointer Update PDU (section 2.2.9.1.1.4)
PDUTYPE2_INPUT 0x1C	Input Event PDU (section 2.2.8.1.1.3)
PDUTYPE2_SYNCHRONIZE 0x1F	Synchronize PDU (section 2.2.1.14.1)
PDUTYPE2_REFRESH_RECT 0x21	Refresh Rect PDU (section 2.2.11.2.1)
PDUTYPE2_PLAY_SOUND 0x22	Play Sound PDU (section 2.2.9.1.1.5.1)
PDUTYPE2_SUPPRESS_OUTPUT 0x23	Suppress Output PDU (section 2.2.11.3.1)
PDUTYPE2_SHUTDOWN_REQUEST 0x24	Shutdown Request PDU (section 2.2.2.1.1)
PDUTYPE2_SHUTDOWN_DENIED 0x25	Shutdown Request Denied PDU (section 2.2.2.2.1)
PDUTYPE2_SAVE_SESSION_INFO 0x26	Save Session Info PDU (section 2.2.10.1.1)
PDUTYPE2_FONTLIST 0x27	Font List PDU (section 2.2.1.18.1)
PDUTYPE2_FONTMAP 0x28	Font Map PDU (section 2.2.1.22.1)
PDUTYPE2_SET_KEYBOARD_INDICATORS 0x29	Set Keyboard Indicators PDU (section 2.2.8.2.1.1)
PDUTYPE2_BITMAPCACHE_PERSISTENT_LIST 0x2B	Persistent Key List PDU (section 2.2.1.17.1)
PDUTYPE2_BITMAPCACHE_ERROR_PDU 0x2C	Bitmap Cache Error PDU ([MS-RDPEGDI] section 2.2.2.3.1)
PDUTYPE2_SET_KEYBOARD_IME_STATUS 0x2D	Set Keyboard IME Status PDU (section 2.2.8.2.2.1)
PDUTYPE2_OFFSCRCACHE_ERROR_PDU 0x2E	Offscreen Bitmap Cache Error PDU ([MS-RDPEGDI] section 2.2.2.3.2)
PDUTYPE2_SET_ERROR_INFO_PDU 0x2F	Set Error Info PDU (section 2.2.5.1.1)
PDUTYPE2_DRAWNINEGRID_ERROR_PDU 0x30	DrawNineGrid Cache Error PDU ([MS-RDPEGDI] section 2.2.2.3.3)
PDUTYPE2_DRAWGDIPLUS_ERROR_PDU 0x31	GDI+ Error PDU ([MS-RDPEGDI] section 2.2.2.3.4)
PDUTYPE2_ARC_STATUS_PDU 0x32	Auto-Reconnect Status PDU (section 2.2.4.1.1)
PDUTYPE2_STATUS_INFO_PDU 0x36	Status Info PDU (section 2.2.5.2)
PDUTYPE2_MONITOR_LAYOUT_PDU 0x37	Monitor Layout PDU (section 2.2.12.1)

compressedType (1 byte): An 8-bit, unsigned integer. The compression type and flags specifying the data following the Share Data Header (section 2.2.8.1.1.1.2).

Flag	Meaning
CompressionTypeMask 0x0F	Indicates the package which was used for compression. See the table which follows for a list of compression packages.
PACKET_COMPRESSED 0x20	The payload data is compressed. This flag is equivalent to MPPC bit C (for more information see [RFC2118] section 3.1).
PACKET_AT_FRONT 0x40	The decompressed packet MUST be placed at the beginning of the history buffer. This flag is equivalent to MPPC bit B (for more information see [RFC2118] section 3.1).
PACKET_FLUSHED 0x80	The decompressor MUST reinitialize the history buffer (by filling it with zeros) and reset the HistoryOffset to zero. After it has been reinitialized, the entire history buffer is immediately regarded as valid. This flag is equivalent to MPPC bit A (for more information see [RFC2118] section 3.1). If the PACKET_COMPRESSED (0x20) flag is also present, then the PACKET_FLUSHED flag MUST be processed first.

Instructions specifying how to set the compression flags can be found in section 3.1.8.2.1.

Possible compression types are as follows.

Value	Meaning
PACKET_COMPR_TYPE_8K 0x0	RDP 4.0 bulk compression (section 3.1.8.4.1).
PACKET_COMPR_TYPE_64K 0x1	RDP 5.0 bulk compression (section 3.1.8.4.2).
PACKET_COMPR_TYPE_RDP6 0x2	RDP 6.0 bulk compression ([MS-RDPEGDI] section 3.1.8.1).
PACKET_COMPR_TYPE_RDP61 0x3	RDP 6.1 bulk compression ([MS-RDPEGDI] section 3.1.8.2).

Instructions specifying how to compress a data stream are listed in section 3.1.8.2, while decompression of a data stream is described in section 3.1.8.3.

compressedLength (2 bytes): A 16-bit, unsigned integer. The compressed length of the packet in bytes.