UDP Packet Format

The packet contains the following data:

  1. Format version number (one byte), set to 1.
  2. A list of data items. Each item has the following format:
    1. Data type number (one byte, must not be zero)
    2. Data length (one byte: N)
    3. N bytes of binary data
  3. A zero byte.

Due to UDP transmission limits, the total packet length is limited to 512 bytes.

Item Types

Type Bytes Symbol Description
1 VAR TIMESTAMP ASCII decimal timestamp, represented as number of seconds since the UNIX epoch, with fractional seconds
2 4 IPV4 Raw IP (version 4) address, in network byte order
3 16 IPV6 Raw IP (version 6) address, in network byte order (not yet supported)
4 VAR ENV Environment variable, formatted as "NAME=VALUE"
5 32 SHA SHA-256 hash of all the data in the packet up to but not including this item, plus the shared secret