initial commit

modules/gre-tunnel/default.nix

@@ -0,0 +1,89 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.clerie.gre-tunnel;
+
+  generateInterfaceUnit = isIPv6: (name: tunnel:
+    nameValuePair "gre-tunnel-${name}" {
+        description = "GRE Tunnel - ${name}";
+        requires = [ "network-online.target" ];
+        after = [ "network.target" "network-online.target" ];
+        wantedBy = [ "multi-user.target" ];
+        environment.DEVICE = name;
+        path = with pkgs; [ iproute ];
+
+        serviceConfig = {
+          Type = "oneshot";
+          RemainAfterExit = true;
+        };
+
+        script = ''
+          ${tunnel.preSetup}
+          ip${optionalString isIPv6 " -6"} tunnel add ${name} mode ${optionalString isIPv6 "ip6"}gre remote ${tunnel.remote} local ${tunnel.local}
+          ip link set ${name} up
+          ip${optionalString isIPv6 " -6"} a add ${tunnel.address} dev ${name}
+          ${tunnel.postSetup}
+        '';
+
+        postStop = ''
+          ip link set ${name} down
+          ip tunnel del ${name}
+          ${tunnel.postShutdown}
+        '';
+      });
+
+  checkOpts = { config, ... }@moduleAttrs: {
+    options = {
+      remote = mkOption {
+        type = types.str;
+        description = "Address of reciever.";
+      };
+      local = mkOption {
+        type = types.str;
+        description = "Address our packets originate from.";
+      };
+      address = mkOption {
+        type = types.str;
+        description = "Our address in this tunnel.";
+      };
+      preSetup = mkOption {
+        type = types.str;
+        default = "";
+        description = "Commands called at the start of the interface setup.";
+      };
+      postSetup = mkOption {
+        type = types.str;
+        default = "";
+        description = "Commands called at the end of the interface setup.";
+      };
+      postShutdown = mkOption {
+        type = types.str;
+        default = "";
+        description = "Commands called after shutting down the interface.";
+      };
+    };
+  };
+
+in {
+  options = {
+    clerie.gre-tunnel = {
+      enable = mkEnableOption "Declarative Policy-Routing";
+      ipv6 = mkOption {
+        type = with types; attrsOf (submodule checkOpts);
+        default = {};
+      };
+      ipv4 = mkOption {
+        type = with types; attrsOf (submodule checkOpts);
+        default = {};
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services =
+    (mapAttrs' (generateInterfaceUnit false) cfg.ipv4)
+    // (mapAttrs' (generateInterfaceUnit true) cfg.ipv6);
+  };
+}