FiresSteamworksPatcher

BepInEx preloader patcher that makes two surgical changes to Valheim's bundled assemblies, so FiresGhettoNetworking can use the Steam networking knobs and ZDO queue sizes it ships configs for. Install it wherever FGN runs — the dedicated server and every client.

This package only does anything when both of these are true on the machine:

1. FiresGhettoNetworking is installed (a *GhettoNetwork*.dll is present anywhere under BepInEx/plugins/).
2. BepInEx loads the patcher at preload (i.e. the DLL is in BepInEx/patchers/).

If FGN isn't present, the patcher writes a single log line and touches nothing — it has no effect of its own and no config file to tune.

Need help, found a bug, want a feature? https://discord.gg/H9uKGcAujs

What it patches

Both edits are done via Cecil at preload time — BEFORE Harmony exists, BEFORE any plugin Awakes. There's no Harmony-equivalent for either patch:

• The Steamworks enum members are missing from the types Valheim ships, so no Harmony patch could surface them — you can't __instance.SomeField = … if the field doesn't exist in the loaded assembly.
• The ZDO queue cap is a const-int load (ldc.i4) inside an IL branch. Harmony can transpile that, but the transpiler IL search and re-emit is heavier than rewriting one constant at preload.

Where it helps — server and client

Earlier builds gated this patcher to dedicated servers only. As of 1.1.0 it runs anywhere FGN is installed, because both edits pull their weight on the client too:

• Dedicated server — the heavy outbound sender: it pushes ZDO updates to every peer each tick and configures a Steam socket per connection. The recv-buffer enums size its accept-from-peer receive buffers, and the SendZDOs queue cap raises its outbound ceiling during initial-sync floods.
• Client — a client receiving a high-throughput server (FGN's HyperBoost or high AutoTune tiers push well past vanilla rates) needs matching receive headroom or it bottlenecks on ingest. The recv-buffer enums are what let FGN enlarge the client's receive buffers to keep up. The SendZDOs queue cap is a smaller win client-side — a client sends comparatively little — but it's harmless and applies in the cases where a client does own and push more.

Without this patcher, FGN still runs: its recv-buffer settings simply cap at Steam's defaults instead of erroring. The patcher is what unlocks the full receive ceiling on both ends.

FGN gate

The patcher scans BepInEx/plugins/ recursively for any DLL whose name matches *GhettoNetwork*.dll. If nothing matches:

1. TargetDLLs returns an empty list, so BepInEx never loads Cecil for Steamworks / assembly_valheim.
2. Defensively, Patch() also short-circuits if it's somehow called anyway.
3. A single log line is written: FiresGhettoNetworking not detected … will not patch any assemblies.

This gate exists because the enum additions are inert without FGN reading them, and the queue-cap raise is small on its own — the win comes from pairing both with FGN's send-rate tiers. Shipping the patcher to a non-FGN install would be a no-op at best, so the gate keeps it from quietly altering other networking mods' headroom.

The gate is evaluated once per process and cached — one Directory.GetFiles(... AllDirectories) at startup, then nothing.

Installation

Install on every machine running FGN — the dedicated server and each client:

1. Install BepInEx — the BepInExPack_Valheim on Thunderstore is the standard one.
2. Install FiresGhettoNetworking — this patcher does nothing without it.
3. Install this package. The patchers/ folder from the zip drops into BepInEx/ so the DLL lands at BepInEx/patchers/<author>-FiresSteamworksPatcher/patchers/FiresSteamworksPatcher.dll. r2modman / Thunderstore Mod Manager handle this automatically.
4. Restart the game / server.

Preloader patchers have no config file — there's nothing to tune. Either FGN is present and the two patches land, or it isn't and the patcher idles.

Where to install

Compatibility

• FiresGhettoNetworking — designed for. If FGN is installed, the patcher activates; if not, it's a no-op.
• BetterNetworking / Serverside Simulations / any other networking overhaul — the FGN gate ensures we won't accidentally alter them. If you uninstall FGN to try another mod, this patcher detects it's gone and stops patching on the next launch.
• Other preloader patchers — coexists. Cecil load order is deterministic (alphabetical by patcher folder). Our edits are additive (one new enum member set, one constant rewrite) and don't conflict with anything I'm aware of.

License

MIT — see LICENSE.

Issues / questions

https://discord.gg/H9uKGcAujs

• v1.1.1 packaging fix — installs to BepInEx/patchers/ correctly

  • Fixed the Thunderstore package layout: the patcher DLL now sits inside a patchers/ folder, so mod managers install it to BepInEx/patchers/ instead of BepInEx/plugins/. The 1.1.0 package shipped the DLL at the zip root, which r2modman/Thunderstore route to plugins/ — where a preloader patcher never runs.
  • No code change: identical client + server patcher to 1.1.0, just packaged correctly.

• v1.1.0

  • The patcher now runs on clients as well as dedicated servers — anywhere FiresGhettoNetworking is installed. The previous dedicated-server-only process gate is gone; the FGN-presence check is the only remaining gate.
  • Why the client matters now: FGN's receive-buffer settings apply on the client too. A client needs matching receive headroom to keep up with a high-throughput server (HyperBoost / high AutoTune tiers push well past vanilla rates), and the patched enum members are what let FGN enlarge the client's receive buffers. Without the patcher those settings cap at Steam's defaults instead of erroring.
  • No change to what gets patched: same recv-buffer enum members and the same ZDOMan.SendZDOs queue-cap raise (10240 -> 102400) as 1.0.0.

• v1.0.0 first release

  • Adds the missing Steamworks recv-buffer enum members (RecvBufferSize / RecvBufferMessages / RecvMaxMessageSize / RecvMaxSegmentsPerPacket) to Steamworks.ESteamNetworkingConfigValue at preload time, so FGN can wire its recv-buffer config knobs without crashing on missing enum values.
  • Raises ZDOMan.SendZDOs outbound queue cap from 10240 to 102400 bytes (10x) by rewriting the constant in IL. Lets FGN's send-rate tier presets actually push more data per tick.
  • Dedicated-server gate: process name has to contain "server" (matches valheim_server.exe / valheim_server.x86_64 / user-renamed variants) or the patcher exits early and touches nothing. Both patches only affect server-side network behavior so a client install would be wasted IL rewrites and the gate keeps the impact strictly where it's intended.
  • FGN-presence gate: if no DLL matching *GhettoNetwork*.dll is found under BepInEx/plugins/, the patcher exits early. Both gates are checked in TargetDLLs (so BepInEx never even loads Cecil) and again defensively in Patch().