Difference between revisions of "Network protocol (Worms 2)"

Revision as of 16:02, 10 July 2020

The Worms 2 servers host rooms in which users can meet to then connect to each other's PCs for playing games.

Official servers

The following servers are hosted by Team17:

Server communication

The server hosting the user, room, and game lists communicates with packets in the following format:

Packet format

Session info

Several packets identify a user, room, or game with the Name and Session fields. The latter provides the following information:

Passing other or invalid combinations (protected users and rooms do not exist, only passworded games) will display a French flag with the default state or a question mark in the UI.

The Worms 2 1.0.1.1 Demo uses significantly different values compared to the full version 1.0.1.5 patch, causing said question marks to appear. However, interactions with full version users still work.

Nation / Flag

Determines which flag is displayed with the user, room, or game. Two flags are custom (Skull and Team17) and are not normally selectable. Des patch can unlock the selection of them, and adds another entry for an "invalid" country code, creating an empty flag.

Game release

Becomes 50 if CD detection failed. The CD detection consists of the following tests:

• Find CD drive, where drives A: and B: are ignored - a found drive letter is stored in the registry under HKCU\SOFTWARE\Team17SoftwareLTD\Worms2\CD. (error 2 otherwise)
• Check the CD being "Worms 2" or "WORMS2". (error 1 otherwise)
• Check if the CD has no free space to ensure it being a CD-ROM. (error 3 otherwise)
• Check if the CD stores an "autorun.inf" file. (error 4 otherwise)

Packet contents

As specified above, the Code of a packet determines the Action to take on either the server or client side and in effect which fields are used. Some codes are reused for multiple occassions, and some are unused in the 1.0.1.5 patch.

Client query packets are also used for server notices, represented by the Type column in the following table:

• Query: A client query to execute an action on the server, always getting a reply (even codes only).
• Reply: A server reply to a client query, always reporting back an Error code, 0 for success (odd codes only).
• Notice: Same as query, but coming as an out-of-bound server packet to update the state on the client, like when another user joins or creates a game.

Note that the same ID counter is incremented for users (UID), rooms (RID), and games (GID) - if a user logs in with UID 0x1000 and immediately creates a room, the RID will be 0x1001. The counter should also start at a high enough value (0x1000 seems to work fine) to not cause duplicate chat messages appearing client-side, apparently because it is also reused as an index in some packets.

1. ↑ ^{1.0 1.1} Only ever sent as a notice by the server, clients disconnect without any query and awaited reply.
2. ↑ Since the host reports its incorrectly detected NAT IP here, Worms 2 Memory Changer has to be used to inject the actual IP address into Worms 2 before creating a room.
3. ↑ Original server always reports E_FAIL in error code, even though messages were sent.

Game room communication

The players are connected via P2P using DirectPlay. This means the ports 47624 (for the lobby connection itself) and 2300 to 2400 (for each player connection) should be forwarded in any router. The fact that each player is connected to another means that the host can leave the game at any time, the remaining players can continue playing without dropping, unlike in Worms Armageddon or Worms World Party.

See also

• Selected sample logs