Directory Game Server Protocol

Introduction

Game Servers such as subgame2 and ASSS register their prescence on Directory Servers. This page describes the portion of the directory server protocol that game servers use.

This system uses UDP packets, most commonly over port 4991. Maximum length of the packet is only limited to the directory server software itself, so it varies from each application. The specific lengths of most fields are static, with the zone description field being the only value that varies its length.

Protocol

g2d

register game server
offset size comment
0      4    ip (leave this set to 0?)
4      2    port
6      2    player count
8      2    saving scores? (boolean)
12     4    version (set this to 134)
14     32   zone name (null terminated)
46     16   password (null terminated)
62     32   reserved (suggested to set this to 0)
92     ?    description (must be null terminated)

Notes on Priit's dirserv

Descriptions are recorded to the stats file with a max length of 490 bytes. The reserved field can be filled with any random data, as the directory server ignores this field completely.

Notes on Catid's dirserv

Validating the packet

• The length of the packet must be greater than 95/0×5F bytes. Basically this means the description can be blank but must be null terminated.
• The first 4 bytes (the IP field) must be zeroed.
• The reserved field must be zeroed.
• The name, password and description must be null terminated.
• The "save scores" field must be either 0 or 1.

Validating the zone name

• Name must be at least one character long.
• First and last characters must cannot be a space.
• No more than one space in a row.
• Only ASCII characters between ‘ ‘ [0x20] and ‘~’ [0x7E], inclusive.

Notes on zone.dat

Due to the format of zone.dat used to store your favourite zones, zone names should not begin with '#' [0x23] or contain any ',' [0x2C].

See also

• CypherJF's original document
• Hammuravi's page
• ASSS Source: src/directory.c
• Directory Client Protocol