uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/modules/services/mail/opendkim.nix

@@ -0,0 +1,167 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.opendkim;
+
+  defaultSock = "local:/run/opendkim/opendkim.sock";
+
+  keyFile = "${cfg.keyPath}/${cfg.selector}.private";
+
+  args = [ "-f" "-l"
+           "-p" cfg.socket
+           "-d" cfg.domains
+           "-k" keyFile
+           "-s" cfg.selector
+         ] ++ optionals (cfg.configFile != null) [ "-x" cfg.configFile ];
+
+in {
+  imports = [
+    (mkRenamedOptionModule [ "services" "opendkim" "keyFile" ] [ "services" "opendkim" "keyPath" ])
+  ];
+
+  ###### interface
+
+  options = {
+
+    services.opendkim = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether to enable the OpenDKIM sender authentication system.";
+      };
+
+      socket = mkOption {
+        type = types.str;
+        default = defaultSock;
+        description = "Socket which is used for communication with OpenDKIM.";
+      };
+
+      user = mkOption {
+        type = types.str;
+        default = "opendkim";
+        description = "User for the daemon.";
+      };
+
+      group = mkOption {
+        type = types.str;
+        default = "opendkim";
+        description = "Group for the daemon.";
+      };
+
+      domains = mkOption {
+        type = types.str;
+        default = "csl:${config.networking.hostName}";
+        defaultText = literalExpression ''"csl:''${config.networking.hostName}"'';
+        example = "csl:example.com,mydomain.net";
+        description = ''
+          Local domains set (see <literal>opendkim(8)</literal> for more information on datasets).
+          Messages from them are signed, not verified.
+        '';
+      };
+
+      keyPath = mkOption {
+        type = types.path;
+        description = ''
+          The path that opendkim should put its generated private keys into.
+          The DNS settings will be found in this directory with the name selector.txt.
+        '';
+        default = "/var/lib/opendkim/keys";
+      };
+
+      selector = mkOption {
+        type = types.str;
+        description = "Selector to use when signing.";
+      };
+
+      configFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        description = "Additional opendkim configuration.";
+      };
+
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    users.users = optionalAttrs (cfg.user == "opendkim") {
+      opendkim = {
+        group = cfg.group;
+        uid = config.ids.uids.opendkim;
+      };
+    };
+
+    users.groups = optionalAttrs (cfg.group == "opendkim") {
+      opendkim.gid = config.ids.gids.opendkim;
+    };
+
+    environment.systemPackages = [ pkgs.opendkim ];
+
+    systemd.tmpfiles.rules = [
+      "d '${cfg.keyPath}' - ${cfg.user} ${cfg.group} - -"
+    ];
+
+    systemd.services.opendkim = {
+      description = "OpenDKIM signing and verification daemon";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+
+      preStart = ''
+        cd "${cfg.keyPath}"
+        if ! test -f ${cfg.selector}.private; then
+          ${pkgs.opendkim}/bin/opendkim-genkey -s ${cfg.selector} -d all-domains-generic-key
+          echo "Generated OpenDKIM key! Please update your DNS settings:\n"
+          echo "-------------------------------------------------------------"
+          cat ${cfg.selector}.txt
+          echo "-------------------------------------------------------------"
+        fi
+      '';
+
+      serviceConfig = {
+        ExecStart = "${pkgs.opendkim}/bin/opendkim ${escapeShellArgs args}";
+        User = cfg.user;
+        Group = cfg.group;
+        RuntimeDirectory = optional (cfg.socket == defaultSock) "opendkim";
+        StateDirectory = "opendkim";
+        StateDirectoryMode = "0700";
+        ReadWritePaths = [ cfg.keyPath ];
+
+        AmbientCapabilities = [];
+        CapabilityBoundingSet = "";
+        DevicePolicy = "closed";
+        LockPersonality = true;
+        MemoryDenyWriteExecute = true;
+        NoNewPrivileges = true;
+        PrivateDevices = true;
+        PrivateMounts = true;
+        PrivateTmp = true;
+        PrivateUsers = true;
+        ProtectClock = true;
+        ProtectControlGroups = true;
+        ProtectHome = true;
+        ProtectHostname = true;
+        ProtectKernelLogs = true;
+        ProtectKernelModules = true;
+        ProtectKernelTunables = true;
+        ProtectSystem = "strict";
+        RemoveIPC = true;
+        RestrictAddressFamilies = [ "AF_INET" "AF_INET6 AF_UNIX" ];
+        RestrictNamespaces = true;
+        RestrictRealtime = true;
+        RestrictSUIDSGID = true;
+        SystemCallArchitectures = "native";
+        SystemCallFilter = [ "@system-service" "~@privileged @resources" ];
+        UMask = "0077";
+      };
+    };
+
+  };
+}