ReSkate/Server/README-linux.md

ReSkate dedicated server on Linux

Native x86_64 build. Same lobby protocol as ReSkateServer.exe; needs no game install. Self-update is disabled on Linux (V1) — update by replacing the binary.

Requirements

• 64-bit Linux (tested: CachyOS/Arch, Ubuntu 22.04+ should work).
• cmake >= 3.24, g++ >= 12 (C++20), libssl-dev (OpenSSL), libcurl headers optional (not needed for V1).
• Steamworks SDK redist beside the binary: libsteam_api.so + steamclient.so (Valve proprietary, not in this repo). Anonymous game-server login, same as Windows.

Where the Steam .so files come from

Same split as Windows (steam_api64.dll + steamclient64.dll/tier0_s64.dll/vstdlib_s64.dll): the release ZIP is expected to ship them; this repo never vendors Valve binaries (see External/README.md, External/manifest.json).

• libsteam_api.so: from the Steamworks SDK redistributable_bin/linux64/ (official download via partner.steamgames.com; any recent 1.x works — the server tries SteamGameServerNetworkingSockets_SteamAPI_v013 then v012, and uses stable flat exports SteamGameServer015/SteamNetworkingUtils004). It is generic; the app is selected at runtime via SteamAppId=3354750.
• steamclient.so (+ tier0/vstdlib if present): not in the SDK. Get it from SteamCMD or a Steam client install, e.g.:

  steamcmd +@sSteamCmdForcePlatformType linux +login anonymous +app_update 1007 +quit
  # then copy steamapps/common/Steamworks\ SDK\ Redist/linux64/steamclient.so
  # next to ReSkateServer (same folder as libsteam_api.so)
  

  or copy/symlink an existing client copy (~/.steam/steam/linux64/steamclient.so, Valve also documents ~/.steam/sdk64/steamclient.so — the server looks there, so ln -s <folder>/steamclient.so ~/.steam/sdk64/steamclient.so works). The server dlopens libsteam_api.so, which in turn loads steamclient.so; either adjacent or LD_LIBRARY_PATH works.

Arch/CachyOS:

sudo pacman -S base-devel cmake openssl

Ubuntu/Debian:

sudo apt install build-essential cmake libssl-dev

Build

cmake --preset linux-x64
cmake --build --preset linux-release -j$(nproc)
./build/linux/ReSkateServer

Binary: build/linux/ReSkateServer (ELF, OUTPUT_NAME ReSkateServer).

Portable tests:

cmake --preset linux-x64 -DDINGOSDK_BUILD_MULTIPLAYER_TESTS=ON
cmake --build --preset linux-release -j$(nproc)
ctest --test-dir build/linux --output-on-failure

Expected: 8 passed (multiplayer_parties, server_activity, server_speed_check, server_config, word_filter, multiplayer_bandwidth, multiplayer_lanes, multiplayer_prediction). Windows-only tests (voice, lobbies, UI) stay WIN32-gated.

Run

1. Put ReSkateServer in its own folder, then fetch the Steam libs (shipped as setup-linux-server-libs.sh beside the binary):

   ./setup-linux-server-libs.sh    # uses the folder it sits in; or --server-dir DIR
   

   Or do it by hand, see below.
2. First run writes ReSkateServer.json; edit name + admins, restart.
3. Optional: world-layers.json for time-of-day / world layers. Normal server runs only read this file (world_layer_scan::read, JSON only) and work on Linux — verified. Get it by either:
   • Windows export once: ReSkateServer.exe --export-world-layers "<Skate folder>" world-layers.json, then copy to the Linux folder; or
   • copy from a Windows player's cache %LOCALAPPDATA%\ReSkate\cache\<build>\world-layers.json (same game build; the server tells admins this path in layer-sync errors). Without it every player keeps their own layers; with it + world_layer_sync the server forces them.
4. No ports need opening (Steam relay). Optional UDP 27015-27016 (port, query_port) for browser ping + faster joins.

Without libsteam_api.so the server exits 1 with: Cannot load .../libsteam_api.so. Put libsteam_api.so (Steamworks SDK) next to the server.

Full command list: Server/README.txt (same on Linux; binary name differs).

systemd

See contrib/reskate-server.service. Install:

sudo cp contrib/reskate-server.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now reskate-server

Notes / limits (V1)

• auto_update / update command: updates_enabled()==false on Linux. check_for_update reports “self-update is not supported on Linux”.
• --export-world-layers on Linux: the reader works, the scanner needs the Windows game (Data/layout.toc + CAS) and oo2core_9_win64.dll (Oodle). Oodle blocks throw Oodle CAS data is only supported on Windows (caught, exit 1, no crash). Export on Windows, copy the JSON over — no game needed on the server itself.
• content_cache dir: %LOCALAPPDATA% on Windows, $XDG_CACHE_HOME/~/.cache on Linux.
• Crypto interop verified: OpenSSL PKCS5_PBKDF2_HMAC(SHA256, 100k) + HMAC-SHA256 matches Windows BCrypt (checked against Python hashlib).