From a476f877d2a3d852cc2b2230ee2ed11b9e7eae1c Mon Sep 17 00:00:00 2001
From: h7x4 <h7x4@nani.wtf>
Date: Sun, 20 Oct 2024 01:29:48 +0200
Subject: [PATCH] systemd hardening

---
 module.nix | 40 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/module.nix b/module.nix
index 009f265..61d3542 100644
--- a/module.nix
+++ b/module.nix
@@ -97,14 +97,48 @@ in
         description = "greg-ng, an mpv based media player";
         wantedBy = [ "graphical-session.target" ];
         partOf = [ "graphical-session.target" ];
-        environment = {
-          RUST_LOG = lib.mkIf cfg.enableDebug "greg_ng=trace,mpvipc=trace";
-        };
+        environment.RUST_LOG = lib.mkIf cfg.enableDebug "greg_ng=trace,mpvipc=trace";
         serviceConfig = {
           Type = "simple";
           ExecStart = "${lib.getExe cfg.package} ${lib.cli.toGNUCommandLineShell { } cfg.settings}";
           Restart = "always";
           RestartSec = 3;
+
+          RestrictAddressFamilies = [ "AF_UNIX" "AF_INET" "AF_INET6" ];
+          AmbientCapabilities = [ "" ];
+          CapabilityBoundingSet = [ "" ];
+          DeviceAllow = [ "" ];
+          LockPersonality = true;
+          # Might work, but wouldn't bet on it with embedded lua in mpv
+          MemoryDenyWriteExecute = false;
+          NoNewPrivileges = true;
+          # MPV and mesa tries to talk directly to the GPU.
+          PrivateDevices = false;
+          PrivateMounts = true;
+          PrivateTmp = true;
+          PrivateUsers = true;
+          ProcSubset = "pid";
+          ProtectClock = true;
+          ProtectControlGroups = true;
+          # MPV wants ~/.cache
+          ProtectHome = false;
+          ProtectHostname = true;
+          ProtectKernelLogs = true;
+          ProtectKernelModules = true;
+          ProtectKernelTunables = true;
+          ProtectProc = "invisible";
+          ProtectSystem = "full";
+          RemoveIPC = true;
+          UMask = "0077";
+          RestrictNamespaces = true;
+          RestrictRealtime = true;
+          RestrictSUIDSGID = true;
+          SystemCallArchitectures = "native";
+          SystemCallFilter = [
+            "@system-service"
+            "~@privileged"
+            "~@resources"
+          ];
         };
       };
     })