Directory Game Server Protocol

Introduction

Game Server's 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 relies on the UDP protocol, port 4991. Max length of the packet is only limited to the directory server software itself (so it varies from each application). However, the specific lengths of fields are pretty much final, the zone description should be the only length that varies.

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)

32 byte reserved field (speculation)

CypherJF has confirmed garbage in this field does not affect the directory server writen by PriitK.

However as of Catids Distributed Directory Server build 4, these 32 bytes must be zeroed. Catid has also stated that this field should be zeroed in a converstation with CypherJF.

It is possible this field was intended for future protocol expansion by VIE.

Notes on PriitK's dirserv

Descriptions are recorded to the stats file with a max length of 490 bytes.

Notes on Catid's dirserv

The following are restrictions were found in Catid's directory server by CypherJF.

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 name, password and description must be null terminated.
• The "save scores" field must be either 0 or 1.

Validating the zone name

• len(name) > 0.
• No leading spaces.
• No more than 1 space in a row.
• Any character between ‘ ‘ and ‘~’.
• No trailing spaces.

See also

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