Add hans: tunnel IPv4 over ICMP

pkgs/tools/networking/hans/default.nix

@@ -0,0 +1,40 @@
+{ stdenv, fetchFromGitHub, nettools }:
+
+let version = "0.4.4"; in
+stdenv.mkDerivation rec {
+  name = "hans-${version}";
+
+  src = fetchFromGitHub {
+    sha256 = "1xskffmmdmg1whlrl5wpkv9z29vh0igrbmsz0b45s9v0761a7kis";
+    rev = "v${version}";
+    repo = "hans";
+    owner = "friedrich";
+  };
+
+  meta = with stdenv.lib; {
+    inherit version;
+    description = "Tunnel IPv4 over ICMP";
+    longDescription = ''
+      Hans makes it possible to tunnel IPv4 through ICMP echo packets, so you
+      could call it a ping tunnel. This can be useful when you find yourself in
+      the situation that your Internet access is firewalled, but pings are
+      allowed.
+    '';
+    homepage = http://code.gerade.org/hans/;
+    license = with licenses; gpl3Plus;
+    platforms = with platforms; linux;
+    maintainers = with maintainers; [ nckx ];
+  };
+
+  buildInputs = [ nettools ];
+
+  postPatch = ''
+    substituteInPlace src/tun.cpp --replace "/sbin/" "/${nettools}/bin/"
+  '';
+
+  enableParallelBuilding = true;
+
+  installPhase = ''
+    install -D -m0755 hans $out/bin/hans
+  '';
+}

pkgs/top-level/all-packages.nix

@@ -1618,6 +1618,8 @@ let
 
   pxz = callPackage ../tools/compression/pxz { };
 
+  hans = callPackage ../tools/networking/hans { };
+
   haproxy = callPackage ../tools/networking/haproxy { };
 
   haveged = callPackage ../tools/security/haveged { };