utp-wire-test-vectors.md

Utp Wire Test Vectors

This document provides a collection of test vectors for encoding and decoding uTP protocol packets

Utp Packets Encodings

This section provides test vectors for the individual protocol packets defined in uTP specification - https://www.bittorrent.org/beps/bep_0029.html.

Each packet input parameters are - (PacketHeader, List[Extension], payload)

Altough spec defines only one extension called - SelectiveAckExtension

Taking that into account, packet inputs can be simplified to - (PacketHeader, Option[SelectiveAckExtension], Payload)

Where: payload is an ByteArray

PacketHeader is object with input paramaters - (type, version, extension, connection_id, timestamp_microseconds, timestamp_difference_microseconds, wnd_size, seq_nr, ack_nr)

Option[SelectiveAckExtension] is either, bitmask of 32bits where each bit represents one packet in the send window or none value which represent lack of any extension.

SYN Packet

Input Parameters

PacketHeader = {
  type: 4
  version: 1
  extension: 0
  connection_id: 10049
  timestamp_microseconds: 3384187322
  timestamp_difference_microseconds: 0
  wnd_size: 1048576
  seq_nr: 11884
  ack_nr: 0
}

SelectiveAckExtension = none
Payload = []

Expected Output

packet = 0x41002741c9b699ba00000000001000002e6c0000

Ack Packet (no extension)

Input Parameters

PacketHeader = {
  type: 2
  version: 1
  extension: 0
  connection_id: 10049
  timestamp_microseconds: 6195294
  timestamp_difference_microseconds: 916973699
  wnd_size: 1048576
  seq_nr: 16807
  ack_nr: 11885
}

SelectiveAckExtension = none
Payload = []

Expected Output

packet = 0x21002741005e885e36a7e8830010000041a72e6d

Ack Packet (with selective ack extension)

Input Parameters

PacketHeader = {
  type: 2
  version: 1
  extension: 1
  connection_id: 10049
  timestamp_microseconds: 6195294
  timestamp_difference_microseconds: 916973699
  wnd_size: 1048576
  seq_nr: 16807
  ack_nr: 11885
}

SelectiveAckExtension = [1, 0, 0, 128] // bitmask with 0 and 31 bit set
Payload = []

Expected Output

packet = 0x21012741005e885e36a7e8830010000041a72e6d000401000080

DATA Packet

Input Parameters

PacketHeader = {
  type: 0
  version: 1
  extension: 0
  connection_id: 26237
  timestamp_microseconds: 252492495
  timestamp_difference_microseconds: 242289855
  wnd_size: 1048576
  seq_nr: 8334
  ack_nr: 16806
}

SelectiveAckExtension = none
Payload = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Expected Output

packet = 0x0100667d0f0cbacf0e710cbf00100000208e41a600010203040506070809

FIN Packet

Input Parameters

PacketHeader = {
  type: 1
  version: 1
  extension: 0
  connection_id: 19003
  timestamp_microseconds: 515227279
  timestamp_difference_microseconds: 511481041
  wnd_size: 1048576
  seq_nr: 41050
  ack_nr: 16806
}

SelectiveAckExtension = none
Payload = []

Expected Output

packet = 0x11004a3b1eb5be8f1e7c94d100100000a05a41a6

RESET Packet

Input Parameters

PacketHeader = {
  type: 3
  version: 1
  extension: 0
  connection_id: 62285
  timestamp_microseconds: 751226811
  timestamp_difference_microseconds: 0
  wnd_size: 0
  seq_nr: 55413
  ack_nr: 16807
}

SelectiveAckExtension = none
Payload = []

Expected Output

packet = 0x3100f34d2cc6cfbb0000000000000000d87541a7