- Separated player handling and creation from network interfaces
- Rewire disconnects to make them not be recursive
- Batching now uses sessions instead of players
- Fixed DisconnectPacket getting sent to players who disconnect of their own accord
Currently this can be used to attack the server by spamming requests for the same chunks forever. This commit prevents that by disconnecting the client if a chunk is requested more than 1 time. It is not necessary to allow more than 1 request per chunk, since RakNet should ensure that these are always delivered correctly.
This introduces several new session handlers, splitting up session handling into several new states:
- Login: Only allows handling the LoginPacket. This is the only time LoginPacket can be sent, and it'll be discarded when sent at any other time.
- Resource packs: Handles only the resource packs sequence (downloading packs and such). This is the only time ResourcePackClientResponse and ResourcePackChunkRequest will be handled.
- Pre-spawn: Only chunk radius requests are accepted during this state.
SimpleNetworkHandler handles all the "rest" of the logic that hasn't yet been separated out into their own dedicated handlers. There's also a NullNetworkHandler which discards all packets while it's active.
This solves a large number of issues with the security of the login sequence. It solves a range of possible DoS attacks and crashes, while also allowing great code simplification and cleanup.
all the things we cared about in here don't exist anymore, so there's no sense in the handler still existing. It can be restored when we want to use the things it still does.
