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>

pkgs/tools/security/fwknop/default.nix

@@ -0,0 +1,72 @@
+{ lib, stdenv, fetchFromGitHub, fetchpatch, autoreconfHook
+, libpcap, texinfo
+, iptables
+, gnupgSupport ? true, gnupg, gpgme # Increases dependencies!
+, wgetSupport ? true, wget
+, buildServer ? true
+, buildClient ? true }:
+
+stdenv.mkDerivation rec {
+  pname = "fwknop";
+  version = "2.6.10";
+
+  src = fetchFromGitHub {
+    owner = "mrash";
+    repo = pname;
+    rev = version;
+    sha256 = "05kvqhmxj9p2y835w75f3jvhr38bb96cd58mvfd7xil9dhmhn9ra";
+  };
+
+  patches = [
+    # Pull patch pending upstream inclusion for -fno-common tollchains:
+    #   https://github.com/mrash/fwknop/pull/319
+    (fetchpatch {
+      name = "fno-common.patch";
+      url = "https://github.com/mrash/fwknop/commit/a8214fd58bc46d23b64b3a55db023c7f5a5ea6af.patch";
+      sha256 = "0cp1350q66n455hpd3rdydb9anx66bcirza5gyyyy5232zgg58bi";
+    })
+  ];
+
+  nativeBuildInputs = [ autoreconfHook ];
+  buildInputs = [ libpcap texinfo ]
+    ++ lib.optionals gnupgSupport [ gnupg gpgme.dev ]
+    ++ lib.optionals wgetSupport [ wget ];
+
+  configureFlags = [
+    "--sysconfdir=/etc"
+    "--localstatedir=/run"
+    "--with-iptables=${iptables}/sbin/iptables"
+    (lib.enableFeature buildServer "server")
+    (lib.enableFeature buildClient "client")
+    (lib.withFeatureAs wgetSupport "wget" "${wget}/bin/wget")
+  ] ++ lib.optionalString gnupgSupport [
+    "--with-gpgme"
+    "--with-gpgme-prefix=${gpgme.dev}"
+    "--with-gpg=${gnupg}"
+  ];
+
+  # Temporary hack to copy the example configuration files into the nix-store,
+  # this'll probably be helpful until there's a NixOS module for that (feel free
+  # to ping me (@primeos) if you want to help).
+  preInstall = ''
+    substituteInPlace Makefile --replace\
+      "sysconfdir = /etc"\
+      "sysconfdir = $out/etc"
+    substituteInPlace server/Makefile --replace\
+      "wknopddir = /etc/fwknop"\
+      "wknopddir = $out/etc/fwknop"
+  '';
+
+  meta = with lib; {
+    description =
+      "Single Packet Authorization (and Port Knocking) server/client";
+    longDescription = ''
+      fwknop stands for the "FireWall KNock OPerator", and implements an
+      authorization scheme called Single Packet Authorization (SPA).
+    '';
+    homepage = "https://www.cipherdyne.org/fwknop/";
+    license = licenses.gpl2Plus;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [ primeos ];
+  };
+}