* Added a new PermissionManager, remove ridiculous cyclic dependencies of Permissions on Server
Aside from all the other ridiculous design problems with the permission system, the biggest problems are its API. This is, once again, a result of poor API design copied from Bukkit.
This pull request removes all permission-related functionality from `PluginManager` and moves it to the `pocketmine\permission\PermissionManager` class.
As can be observed from the removed code in the diff, the permissions system was previously entirely dependent on the Server, because it needed to get the PluginManager for registering permissions. This is utterly ridiculous. This refactor isolates _most_ permission-related functionality within the `permission` namespace.
As mentioned above, this stupid API is a direct result of copying from Bukkit. If you look at the API documentation for Bukkit for `PluginManager` you will see that the methods I'm deprecating here are also in there.
## Changes
- Added a new `PermissionManager` class. This can be accessed via its singleton `getInstance()` static method.
- Deprecated the following `PluginManager` methods - these will be removed no later than 4.0.0:
- `getPermission()`
- `addPermission()`
- `removePermission()`
- `getDefaultPermissions()`
- `recalculatePermissionDefaults()`
- `subscribeToPermission()`
- `unsubscribeFromPermission()`
- `getPermissionSubscriptions()`
- `subscribeToDefaultPerms()`
- `unsubscribeFromDefaultPerms()`
- `getDefaultPermSubscriptions()`
- `getPermissions()`
- Added `Internet::getIP()`, `Internet::getURL()`, `Internet::postURL()`, and `Internet::simpleCurl()`.
- Deprecated the corresponding functions in `Utils`. Updating to the new functions is as simple as replacing `Utils` with `Internet`, since this doesn't break backwards compatibility.
The deprecations should be catered for by plugin developers. These deprecated redirects will be removed no later than 4.0.0.
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.
