NetworkSession and some SessionHandlers hold cyclic refs to each other, stopping them getting destroyed. Unfortunately, these also reference the player, stopping that getting destroyed too.
The cycle garbage collector will deal with this, but it's best to get rid of the cyclic refs for immediate collection.
I considered renaming sendDataPacket() to dataPacket() to reduce the BC breaks, but the parameter set has changed, which might cause astonishing behaviour, so it's better to break it in a loud way. Also, this has a clearer name.
- 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
This also has the happy side effect of removing a cyclic dependency between Config and Server. There's only the dependency on MainLogger left to get rid of now.
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.
This consolidates the Player entity construction and makes it more organized and consistent. There is of course a lot more work to do apart from this on player construction.
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.
DataPacketSendEvent and DataPacketReceiveEvent will no longer capture BatchPackets
In most places strings are now used instead of DataPackets, to remove limitations on what data can be sent to a network interface
Removed CraftingManager's cyclic dependency on Server
There is a lot more work to do aside from this, but this commit is intended to clean up what is necessary to fix the handling of BatchPacket.
