MHF Patch Server

Patch server for the new Monster Hunter Frontier launcher.

About

The pupose of this patch server is to provide a way for MHF servers to distribute file changes to users while minimizing the amount of time spent checksumming and the amount of data transfered.

With this, it should be much easier to ensure users always get the latest translations, custom skins, game fixes, etc.

Setup

1. Either clone the repo or extract the latest release into a folder.
2. Put the files you want clients to check against inside the game/ folder.
3. Update the SignV2.PatchServer config on your Erupe server to point to the address the patch server will run on. For example: https://10.20.30.40:8081.
4. Run the executable.

When adding or modifying files inside game/, the server needs to be restarted.

How does it work

As mentioned, the way the client and the server communicate was designed in order to minimize the time clients spend checking for files before before starting the game, and the amount of data the server will need to transfer after updates.

When clients connect for the first time to the server, the exchange goes more or less like this:

1. Client connects to patch server for the first time
2. Patch server returns a list of macthing paths and versions the client must have and a 'folder version' that will be used in subsequent requests
3. Client matches the returned paths and versions against the local files, and only downloads files that do not match

When doing subsequent connections, we can use the 'folder version' to skip the client check:

1. Client connects to patch server, sending the last received 'folder version'
   • If the folder version matches the patch server's version, it returns no data and the client can log in directly
   • If the folder version does not match the patch server's version, it follows the same flow as when connecting for the first time

The main launcher implementation is also configured to only do 1 request at a time, in order to not overwhelm the server.

Important: Do notice that the patch server does not give any guarantees that the client will have the same version as the server. This means it does not stop cheaters from running custom launchers that bypass the verification. It does make it much more convenient for normal users, but that's the extent of it.

Config

Name	Default	Description
Port	8081	Port the server will run on
GameFolder	./game	Folder containing the files you want your clients to match
Force	false	Forces the client to check all files client-side. The client will still only request files that differ from the server. This is disabled by default so clients can log in faster, but it can be enabled to guarantee file consistency.