New Lobby Protocol

Goals

1. Be compatible with 2.3.x
2. Split ingame communication from Lobby communication
3. Let the client set the protocol while connecting
4. New efficient and extensible protocol
   1. Version command first (if none is send use the "old" Protocol)
   2. One packet for "command" and "data"
   3. Variable sized

The current implementation

Currently the Protocol is based on a fixed size Big Endian Struct, which is defined as "GAMESTRUCT" ingame.

The function NETsendGAMESTRUCT in lib/netplay/netplay.c defines it as follows:

Type	GAMESTRUCT Var	Description
uint32_t	GAMESTRUCT_VERSION
char[64]	name	game name
int32_t	desc.dwSize	size of hostname
int32_t	desc.dwFlags	Unused
char[40]	desc.host	IP Adress of the host (NOT IN USE 2.3/master!)
int32_t	desc.dwMaxPlayers	Max Players (2/4/8)
int32_t	desc.dwCurrentPlayers	Current players
int32_t	desc.dwUserFlags[0]	Unused
int32_t	desc.dwUserFlags[1]	Unused
int32_t	desc.dwUserFlags[2]	Unused
int32_t	desc.dwUserFlags[3]	Unused
char[40]	secondaryHosts[0]	Additional IP Address of the host (NOT IN USE 2.3/master!)
char[40]	secondaryHosts[1]	Additional IP Address of the host (NOT IN USE 2.3/master!)
char[159]	extra	Unused (pre 2.3.6 it size was 239 bytes)
char[40]	mapname	Name of the map hosted
char[40]	hostname	The hosts player name
char[64]	versionstring	Version as string (2.3.4/2.3 svn/netcode xxx)
char[255]	modlist	List of mods (i think "," seperated)
uint32_t	game_version_major
uint32_t	game_version_minor
uint32_t	privateGame	(bool) Private game?
uint32_t	pureGame	(bool) any mods?
uint32_t	Mods	Count of mods
uint32_t	gameId	Game ID generated at server side
uint32_t	future2	Unused
uint32_t	future3	Unused
uint32_t	future4	Unused

NETsendGAMESTRUCT is currently used for in game communication (when a client joins a game) and communications betweend the lobby server

NETRecvGAMESTRUCT translates a received struct back into a ingame "GAMESTRUCT"

My proposal for the new "Protocol"

It uses BSON as serializer ( ​http://bsonspec.org/ ) and the this format:

<unsigned integer>	length of data
<BSON>	the BSON Data

While the BSON data looks like:

--> {"method": "addGame", "params": {"description": "Fast, NTW", "maxPlayers": 8, "currentPlayers": 1}, "id": 1}
<-- {"status": 0, "result": "Welcome to Warzone! Your game is now listed in the lobby server", "id": 1}

Connecting to the Masterserver v4

1. command version

version

4

response:

connection closes on a wrong version

2. command login

--> {"method": "login", "params": {"username": "Fastdeath", "password": "mysecretpass"}, "id": 1}

response:

<-- {"status": 0, "result": {"userid": 2, "sessionid": "<long-session-id>"}, "id": 1}

or:

<-- {"status": -405, "result": "Unknown user or wrong password", "id": 1}

Creating a game

1. command addgame

--> {"method": "addGame", "params": {"description": "Fast, NTW", "maxPlayers": 8, "currentPlayers": 1}, "id": 2}

response:

<-- {"status": 0, "result": {"gameId": 1, "motd": "Welcome to Warzone! Your game is now listed in the lobby server"}, "id": 2}

or:

<-- {"status": -403, "result": "Please upgrade your Warzone to 2.3.7! See ​http://wz2100.net.", "id": 2}

or:

<-- {"status": -403, "result": "Game unreachable, failed to open a connection to port 2100.", "id": 2}

or:

<-- {"status": -403, "result": "Game name not acceptable. The game is NOT hosted, change the name of your game.", "id": 2}

Joining a game

1. command list

--> {"method": "list", "params": "", "id": 2}

response:

<-- {"status": 0, "result": {"count": 10, "list": {[GAMEDATA1, GAMEDATA2, ...}, "id": 2}

2. Player joins the game

The Game joins the host with the users-id and its session-id.

3. Host adds and checks the player: addPlayer

--> {"method": "addPlayer", "params": {"userid": 2, "sessionid": "<long-session-id>"}, "id": 3}

response:

<-- {"status": 0, "result": "ok", "id": 3}

or:

<-- {"status": -406, "result": "invalid", "id": 3}

4. Gamehost sends the GAMESTRUCT to all clients

Leaving a game

1. The game leaves the host as usual

2. Gamehost sends command delPlayer

--> {"method": "delPlayer", "params": {"userid": 2}, "id": 4}

response:

<-- {"status": 0, "result": "ok", "id": 4}

When the game starts or the hosts closes the game

Gamehost sends command delGame

--> {"method": "delGame", "params": {"userid": 2}, "id": 4}

response:

<-- {"status": 0, "result": "ok", "id": 4}

The lobbyserver should check any open games for theier responsibilty and close "lost" games when required.