Half-Life

Name String "HalfLife" Enumerated Type LPI_PROTO_UDP_HL Category Gaming Priority 3 Transport UDP Source File lpi_halflife.cc

Half-Life is a popular First Person Shooter game. Although Half-Life itself is not commonly played over the Internet, modifications and spin-offs based on the Half-Life engine are, particularly CounterStrike. All these games use the same network protocol for online gameplay, which we refer to as the Half-Life protocol.

The Half-Life protocol is very similar to the Quake? protocol, due to the original Half-Life game being based on the old Quake 1 engine.

Matching Half-Life

Any payload for either direction must match the following pattern (which dates back to the original Quake engine):

Byte 1 Byte 2 Byte 3 Byte 4 0xff 0xff 0xff 0xff

Because this pattern is fairly common, we also employ payload length restrictions. If any of the following conditions are met, we will match the Half-Life protocol: