rename project

.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["mix.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

.gitignore

@@ -0,0 +1,24 @@
+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where 3rd-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+dough-*.tar
+

README.md

@@ -1,21 +1,21 @@
-# Edoh
+# Dough
 
 **TODO: Add description**
 
 ## Installation
 
 If [available in Hex](https://hex.pm/docs/publish), the package can be installed
-by adding `edoh` to your list of dependencies in `mix.exs`:
+by adding `dough` to your list of dependencies in `mix.exs`:
 
 ```elixir
 def deps do
   [
-    {:edoh, "~> 0.1.0"}
+    {:dough, "~> 0.1.0"}
   ]
 end
 ```
 
 Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
 and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
-be found at [https://hexdocs.pm/edoh](https://hexdocs.pm/edoh).
+be found at [https://hexdocs.pm/dough](https://hexdocs.pm/dough).
 

config/config.exs

@@ -0,0 +1,30 @@
+# This file is responsible for configuring your application
+# and its dependencies with the aid of the Mix.Config module.
+use Mix.Config
+
+# This configuration is loaded before any dependency and is restricted
+# to this project. If another project depends on this project, this
+# file won't be loaded nor affect the parent project. For this reason,
+# if you want to provide default values for your application for
+# 3rd-party users, it should be done in your "mix.exs" file.
+
+# You can configure your application as:
+#
+#     config :dough, key: :value
+#
+# and access this configuration in your application as:
+#
+#     Application.get_env(:dough, :key)
+#
+# You can also configure a 3rd-party app:
+#
+#     config :logger, level: :info
+#
+
+# It is also possible to import configuration files, relative to this
+# directory. For example, you can emulate configuration per environment
+# by uncommenting the line below and defining dev.exs, test.exs and such.
+# Configuration from the imported file will override the ones defined
+# here (which is why it is important to import them last).
+#
+#     import_config "#{Mix.env}.exs"

lib/dough.ex

@@ -0,0 +1,36 @@
+defmodule Dough do
+  @moduledoc false
+
+  use Application
+
+  import Supervisor.Spec
+  import Cachex.Spec
+
+
+  def start(_type, _args) do
+    # List all child processes to be supervised
+    children = [
+      # Starts a worker by calling: Dough.Worker.start_link(arg)
+      # {Dough.Worker, arg},
+      # Plug.Adapters.Cowboy.child_spec(:https, Dough.Router, [], port: 8331, keyfile: "priv/ssl/localhost.key", certfile: "priv/ssl/localhost.crt", otp_app: :dough)
+      worker(Cachex, [:dough, [
+        expiration: expiration(
+          default: :timer.seconds(6000),
+          interval: :timer.seconds(300),
+          lazy: true)
+      ]]),
+      
+      {Plug.Adapters.Cowboy2, scheme: :https, plug: Dough.Router, options: [
+        port: 8331,
+        otp_app: :dough,
+        keyfile: "priv/ssl/localhost.key",
+        certfile: "priv/ssl/localhost.crt"
+      ]}
+    ]
+
+    # See https://hexdocs.pm/elixir/Supervisor.html
+    # for other strategies and supported options
+    opts = [strategy: :one_for_one, name: Dough.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+end

lib/dough/context.ex

@@ -0,0 +1,26 @@
+defmodule Dough.RequestContext do
+  require Logger
+
+  
+  defstruct [:start, :close, :lookup, :cache, :ttl]
+  
+  def ctx_start(ctx) do 
+    Map.put(ctx, :start, System.monotonic_time(:milliseconds))
+  end
+  def ctx_close(ctx) do
+    Map.put(ctx, :close, System.monotonic_time(:milliseconds))
+  end
+  def ctx_lookup(ctx, dns_record) do
+    Map.put(ctx, :lookup, dns_record.qdlist |> List.first())
+  end
+  def ctx_cachehit(ctx, v) do
+    Map.put(ctx, :cache, v)
+  end
+  def ctx_ttl(ctx, ttl) do
+    Map.put(ctx, :ttl, ttl)
+  end
+
+  def ctx_log_out(ctx) do
+    Logger.info "#{ctx.lookup.type} - #{ctx.lookup.domain} - TTL #{ctx.ttl} | #{ctx.cache} - #{ctx.close - ctx.start}ms"
+  end
+end

lib/dough/dohplug.ex

@@ -0,0 +1,82 @@
+defmodule Dough.DoHPlug do
+  import Socket.Datagram, only: [send!: 3, recv!: 1]
+  import Plug.Conn
+  import Dough.TTL
+  import Dough.RequestContext
+
+  require Logger
+  require DNS
+
+  def init(options), do: options
+
+  def call(conn, _opts) do
+
+    ctx = %Dough.RequestContext{} |> ctx_start()
+
+    dns_message = case parse_doh(conn) do
+      {:ok, msg} -> msg
+      {:error, _} ->
+        Logger.error conn.method
+        raise Dough.NotAllowed, ""
+    end
+
+    {cache_hit, ttl, dns_resp} = fetch_dns(dns_message)
+
+    decoded = DNS.Record.decode(dns_message)
+
+    ctx = ctx_lookup(ctx, decoded)
+          |> ctx_cachehit(cache_hit)
+          |> ctx_ttl(ttl)
+          |> ctx_close()
+
+    Dough.RequestContext.ctx_log_out(ctx)
+
+    conn
+    # support for [RFC5861] / cache control extensions
+    |> put_resp_header("cache-control", "max-age=#{ttl}, stale-while-revalidate=#{ttl * 2}, stale-if-error=#{ttl * 10}")
+    |> put_resp_header("content-type", content_type(conn))
+    |> send_resp(200, dns_resp)
+  end
+
+  def content_type(conn) do
+    case List.keyfind(conn.req_headers, "accept", 0) do
+      {"accept", accept} -> accept
+      nil -> "application/dns-message"
+    end
+  end
+
+  def fetch_dns(dns_message) do
+    case ttlcache_lookup(dns_message) do
+      nil ->
+        resp = handoff_dns(dns_message)
+        ttl = ttl_extract(resp)
+        ttlcache_set(dns_message, resp, ttl)
+
+        {:miss, ttl, resp}
+      result ->
+        ttl = ttl_extract(result)
+        {:hit, ttl, result}
+    end
+
+  end
+
+  def parse_doh(conn) do
+    conn = fetch_query_params conn
+    case conn.method do
+      "GET" -> {:ok, Base.url_decode64!(conn.query_params["dns"], padding: false, ignore: :whitespace)}
+      "POST" ->
+        {:ok, body, _conn} = read_body(conn)
+        {:ok, body}
+      _ -> {:error, nil}
+    end
+  end
+
+  def handoff_dns(dns_message) do
+    client = Socket.UDP.open!
+    send!(client, dns_message, {"8.8.8.8", 53})
+    {data, _server} = recv!(client)
+    data
+  end
+
+end
+

lib/dough/exceptions.ex

@@ -0,0 +1,13 @@
+defmodule Dough.NotAllowed do
+  defexception [plug_status: 405, message: "Method Not Allowed"]
+end
+
+defmodule Dough.ServerError do
+  defexception [plug_status: 500, message: "Server Error"]
+end
+
+defimpl Plug.Exception, for: [Dough.NotAllowed, Dough.ServerError] do
+  def status(exc) do 
+    exc.plug_status 
+  end
+end

lib/dough/router.ex

@@ -0,0 +1,18 @@
+defmodule Dough.Router do
+  use Plug.Router
+  use Plug.ErrorHandler
+
+  if Mix.env == :dev do
+    use Plug.Debugger
+  end
+
+  require Logger
+
+  plug :match
+  plug :dispatch
+
+  get "/", do: send_resp(conn, 200, "")
+  match "/dns-query", to: Dough.DoHPlug
+  match _, do: send_resp(conn, 404, "oopsie") 
+
+end

lib/dough/ttlcache.ex

@@ -0,0 +1,42 @@
+defmodule Dough.TTL do
+
+  require Logger
+
+  def ttlcache_lookup(dns_message) do
+    case Cachex.get(:dough, _hashify_dns(dns_message)) do
+      {:ok, nil} -> nil
+      {:ok, value} -> value
+      {:error, :nocache} -> raise Dough.ServerError, message: "Cache failure"
+    end
+  end
+
+  def ttlcache_set(dns_message, dns_result, ttl) do
+    Cachex.put(:dough, _hashify_dns(dns_message), dns_result, ttl: :timer.seconds(ttl))
+    dns_result
+  end
+
+  def ttl_extract(dns_result) do
+    decoded = DNS.Record.decode(dns_result)
+    answers = {decoded.anlist |> List.first(), decoded.nslist |> List.first()}
+
+    case answers do
+      {nil, nss} ->
+        # {:dns_rr, 'd.akamai.net', :soa, :in, 0, 901, {'n0d.akamai.net', 'hostmaster.akamai.com', 1534350643, 1000, 1000, 1000, 1800}, :undefined, [], false}.
+        nss
+        |> elem(6)
+        # {'n0d.akamai.net', 'hostmaster.akamai.com', 1534350643, 1000, 1000, 1000, 1800}
+        |> elem(6)
+
+      {ans, nil} ->
+        ans.ttl
+      {ans, _} ->
+        ans.ttl
+    end
+  end
+
+  def _hashify_dns(dns_message) do
+    :crypto.hash(:sha256, dns_message)
+    |> Base.encode16
+  end
+
+end

mix.exs

@@ -0,0 +1,31 @@
+defmodule Dough.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :dough,
+      version: "0.1.0",
+      elixir: "~> 1.6",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger, :cowboy, :plug, :dns, :cachex],
+      mod: {Dough, []}
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      {:cowboy, "~> 2.4.0"},
+      {:plug, "~> 1.5"},
+      {:dns, "~> 2.1.0"},
+      {:cachex, "~> 3.0.3"}
+    ]
+  end
+end

mix.lock

@@ -0,0 +1,12 @@
+%{
+  "cachex": {:hex, :cachex, "3.0.3", "4e2d3e05814a5738f5ff3903151d5c25636d72a3527251b753f501ad9c657967", [:mix], [{:eternal, "~> 1.2", [hex: :eternal, repo: "hexpm", optional: false]}, {:unsafe, "~> 1.0", [hex: :unsafe, repo: "hexpm", optional: false]}], "hexpm"},
+  "cowboy": {:hex, :cowboy, "2.4.0", "f1b72fabe9c8a5fc64ac5ac85fb65474d64733d1df52a26fad5d4ba3d9f70a9f", [:rebar3], [{:cowlib, "~> 2.3.0", [hex: :cowlib, repo: "hexpm", optional: false]}, {:ranch, "~> 1.5.0", [hex: :ranch, repo: "hexpm", optional: false]}], "hexpm"},
+  "cowlib": {:hex, :cowlib, "2.3.0", "bbd58ef537904e4f7c1dd62e6aa8bc831c8183ce4efa9bd1150164fe15be4caa", [:rebar3], [], "hexpm"},
+  "dns": {:hex, :dns, "2.1.0", "4777fe07ae3060c1d5d75024f05c26d7e11fa701d48a6edb9fc305d24cd12c8c", [:mix], [{:socket, "~> 0.3.13", [hex: :socket, repo: "hexpm", optional: false]}], "hexpm"},
+  "eternal": {:hex, :eternal, "1.2.0", "e2a6b6ce3b8c248f7dc31451aefca57e3bdf0e48d73ae5043229380a67614c41", [:mix], [], "hexpm"},
+  "mime": {:hex, :mime, "1.3.0", "5e8d45a39e95c650900d03f897fbf99ae04f60ab1daa4a34c7a20a5151b7a5fe", [:mix], [], "hexpm"},
+  "plug": {:hex, :plug, "1.6.2", "e06a7bd2bb6de5145da0dd950070110dce88045351224bd98e84edfdaaf5ffee", [:mix], [{:cowboy, "~> 1.0.1 or ~> 1.1 or ~> 2.4", [hex: :cowboy, repo: "hexpm", optional: true]}, {:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}], "hexpm"},
+  "ranch": {:hex, :ranch, "1.5.0", "f04166f456790fee2ac1aa05a02745cc75783c2bfb26d39faf6aefc9a3d3a58a", [:rebar3], [], "hexpm"},
+  "socket": {:hex, :socket, "0.3.13", "98a2ab20ce17f95fb512c5cadddba32b57273e0d2dba2d2e5f976c5969d0c632", [:mix], [], "hexpm"},
+  "unsafe": {:hex, :unsafe, "1.0.0", "7c21742cd05380c7875546b023481d3a26f52df8e5dfedcb9f958f322baae305", [:mix], [], "hexpm"},
+}

priv/ssl/localhost.crt

@@ -0,0 +1,18 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

priv/ssl/localhost.key

@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----
+MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQC5FPP/hFyhe4KZ
+ZxLyegl7PHyph2TaxJx+Thmd9hNn9XPrq7G5R6N9My7Z/Woa0FMjJ/yGmbDfNsSH
+4Rxa5Dn0pGdcNftp+oYV4zZbu7PNbV64X9yys1puNEl5hJVm3AmsVIp2GHddVVzt
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+Tj06/FzjAgMBAAECggEAYNrONVEXCIqR9aUzDSFABPXKZw0rgjCRlKdaUIeN8EFK
+wHHBN6x9qe82/WzYMeADIcqzI90Z6jXG8zSimg4FJjlCvcaiIvuvX5TfxXGczkwF
+3YaNABdLo5BJQwZXCNTtWvmC2/pBvN4HG4ao9spleDXNJae4GCxD4glV1C8GZ+1+
+4vakqKsUwU9LqQBC7JwrnDFwlLSutGE7yqpblzZeyO3ByzK8aKfktkZXurfshumk
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+KzfEeLg9ERGFQf73fhod1oCkaSjqw/SgnwY2+3kGwQKBgQDgfTcySZNpGCJRm5jH
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+ygz5YWvZgJk+i54X7AICZf/v521omjBTLHaKMKo0Pm6dXRCG4408lgNkxQKBgHJy
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+3TWHIW00Tru3hpyNBWV/qaSdhh5WwAg8pK6Cz0a/aKhGu7yVG5F97+2IbjSHTp0S
+oEscfD3G2xBTZCHftNQ4hhopoV+t6OJqZZLoZRiPAoGBANZd2Xj8SCENVjVQS8+r
+CoMwZb8lpisdUh1aqpyL7KokvWA2/c6/cEd5A0I+1o63T7N7YUJv+CV3qBeC0u10
+OIYkn98uzjBMekTYJs/RSDV8nRu766x5KiGqezftH8fMeIMn/fJ9XEIAk9aSMT+F
+KjzV3G0y/iLykshNL+vDW3Ou
+-----END PRIVATE KEY-----

test/dough_tests.exs

@@ -0,0 +1,8 @@
+defmodule DoughTest do
+  use ExUnit.Case
+  doctest Dough
+
+  test "greets the world" do
+    assert Dough.hello() == :world
+  end
+end

test/test_helper.exs

@@ -0,0 +1 @@
+ExUnit.start()