Merge branch 'main' of git.colon-three.com:kodi/amethyst

lib/data.ex

@@ -18,21 +18,55 @@ defmodule Amethyst.Minecraft.Write do
   import Bitwise
 
   @moduledoc """
-  This module contains functions for writing certain Minecraft data types which are more complex
+  This module contains functions for writing Minecraft data.
-  than simple binary data.
+
+  Each function in this module takes in an input of the proper type and returns a binary
+  of the encoded data.
   """
 
-  def uuid(uuid) do
+  def uuid(uuid) when is_binary(uuid) do
     UUID.string_to_binary!(uuid)
   end
 
-  def bool(value) do
+  def bool(value) when is_boolean(value) do
     case value do
       true -> <<0x01::8>>
       false -> <<0x00::8>>
     end
   end
 
+  def byte(value) when value in -128..127 do
+    <<value::8-signed-big>>
+  end
+
+  def ubyte(value) when value in 0..255 do
+    <<value::8-unsigned-big>>
+  end
+
+  def short(value) when value in -32_768..32_767 do
+    <<value::16-signed-big>>
+  end
+
+  def ushort(value) when value in 0..65_535 do
+    <<value::16-unsigned-big>>
+  end
+
+  def int(value) when value in -2_147_483_648..2_147_483_647 do
+    <<value::32-signed-big>>
+  end
+
+  def long(value) when value in -9_223_372_036_854_775_808..9_223_372_036_854_775_807 do
+    <<value::64-signed-big>>
+  end
+
+  def float(value) when is_number(value) do
+    <<value::32-float>>
+  end
+
+  def double(value) when is_number(value) do
+    <<value::64-float>>
+  end
+
   def varint(value) when value in -2_147_483_648..2_147_483_647 do
     <<value::32-unsigned>> = <<value::32-signed>> # This is a trick to allow the arithmetic shift to act as a logical shift
     varnum("", value)
@@ -63,19 +97,44 @@ defmodule Amethyst.Minecraft.Write do
   def string(value) do
     <<varint(byte_size(value))::binary, value::binary>>
   end
+
+  def position({x, y, z}) do
+    <<x::signed-big-26, z::signed-big-26, y::signed-big-12>>
+  end
+
+  @doc """
+  Writes a list of elements with the given `callback` function. This does not
+  prefix the list with a length, remember to do that yourself if needed.
+
+     iex> Amethyst.Minecraft.Write.list([1, 2, 3, 4], &Amethyst.Minecraft.Write.byte/1)
+     <<1, 2, 3, 4>>
+  """
+  def list(list, callback) do
+    Enum.reduce(list, "", &(&2 <> callback.(&1)))
+  end
+
+  @doc """
+  Shorthand function for writing a value which may not be present. If `value` is `nil`,
+  writes `false`, otherwise writes `true` followed by the value using `callback`.
+  """
+  def option(value, callback) do
+    case value do
+      nil -> bool(false)
+      v -> bool(true) <> callback.(v)
+    end
+  end
 end
 
 defmodule Amethyst.Minecraft.Read do
   import Bitwise
 
   @moduledoc """
-  This module contains functions for reading Minecraft data. Unlike Amethyst.Minecraft.Write, this
+  This module contains functions for reading Minecraft data.
-  includes all supported data types in order to make the interface more consistent.
 
   These functions allow you to chain them into eachother, at the end they will produce a list of all the
   values they have read.
 
-  You may use the helper function Amethyst.Minecraft.Read.start/1 to start the chain with a binary buffer.
+  You may use the helper function `Amethyst.Minecraft.Read.start/1` to start the chain with a binary buffer.
   The return value of the chain is a tuple containing the list of values and the remaining binary buffer.
 
       iex> alias Amethyst.Minecraft.Read
@@ -83,9 +142,15 @@ defmodule Amethyst.Minecraft.Read do
       {[true, 999, 64], ""}
   """
 
+  @doc """
+  This function structures an input binary to be used by the functions in `Amethyst.Minecraft.Read`.
+  """
   def start(binary) do
     {[], binary, :reversed}
   end
+  @doc """
+  This function structures the result of the functions in `Amethyst.Minecraft.Read` to be used in the same order they were read.
+  """
   def stop({acc, rest, :reversed}) do
     {Enum.reverse(acc), rest}
   end
@@ -135,6 +200,9 @@ defmodule Amethyst.Minecraft.Read do
     {[data | acc], rest, :reversed}
   end
 
+  @doc """
+  Reads a varint. `read` tracks the number of bytes read and `nacc` tracks the number being read.
+  """
   def varint(tuple, read \\ 0, nacc \\ 0)
   def varint({acc, <<1::1, value::7, rest::binary>>, :reversed}, read, nacc) when read < 5 do
     varint({acc, rest, :reversed}, read + 1, nacc + (value <<< (7 * read)))
@@ -151,6 +219,9 @@ defmodule Amethyst.Minecraft.Read do
     raise RuntimeError, "Got an incomplete varint!"
   end
 
+  @doc """
+  Reads a varlong. `read` tracks the number of bytes read and `nacc` tracks the number being read.
+  """
   def varlong(tuple, read \\ 0, nacc \\ 0)
   def varlong({acc, <<1::1, value::7, rest::binary>>, :reversed}, read, nacc) when read < 10 do
     varlong({acc, rest, :reversed}, read + 1, nacc + (value <<< (7 * read)))
@@ -161,10 +232,10 @@ defmodule Amethyst.Minecraft.Read do
     {[value | acc], rest, :reversed}
   end
   def varlong(_, read, _) when read >= 10 do
-    raise RuntimeError, "Got a varint which is too big!"
+    raise RuntimeError, "Got a varlong which is too big!"
   end
   def varlong({_, ""}, _, _) do
-    raise RuntimeError, "Got an incomplete varint!"
+    raise RuntimeError, "Got an incomplete varlong!"
   end
 
   def string({acc, data, :reversed}) do

lib/servers/configuration.ex

@@ -97,11 +97,11 @@ defmodule Amethyst.Server.Configuration do
   # Serverbound Known Packs https://wiki.vg/Protocol#Serverbound_Known_Packs
   def deserialize(0x07, data) do
     {[count], rest} = Read.start(data) |> Read.varint |> Read.stop
-    {packs, _} = Enum.reduce(0..count, {[], rest}, fn _, {acc, rest} ->
+    {packs, _} = Enum.reduce(1..count, {[], rest}, fn _, {acc, rest} ->
       {[namespace, id, version], rest} = Read.start(rest) |> Read.string |> Read.string |> Read.string |> Read.stop
       {[{namespace, id, version} | acc], rest}
     end)
-    {:resource_pack_stack, packs}
+    {:serverbound_known_packs, packs}
   end
   def deserialize(type, _) do
     raise RuntimeError, "Got unknown packet type #{type}!"
@@ -143,16 +143,12 @@ defmodule Amethyst.Server.Configuration do
   end
   # Remove Resource Pack https://wiki.vg/Protocol#Remove_Resource_Pack_(configuration)
   def serialize({:remove_resource_pack, id}) do
-    if id == nil do
+    Write.option(id, &Write.string/1)
-      Write.varint(0x08) <> <<0x00>>
-    else
-      Write.varint(0x08) <> <<0x01>> <> Write.string(id)
-    end
   end
   # Add Resource Pack https://wiki.vg/Protocol#Add_Resource_Pack_(configuration)
   def serialize({:add_resource_pack, id, url, hash, forced, msg}) do
     Write.varint(0x09) <> Write.string(id) <> Write.string(url) <> Write.string(hash) <>
-    if(forced, do: <<0x01>>, else: <<0x00>>) <> if(msg == nil, do: <<0x00>>, else: <<0x01>> <> Write.string(msg))
+    Write.bool(forced) <> Write.option(msg, &Write.string/1)
   end
   # Store Cookie https://wiki.vg/Protocol#Store_Cookie_(configuration)
   def serialize({:store_cookie, id, data}) do
@@ -164,7 +160,7 @@ defmodule Amethyst.Server.Configuration do
   end
   # Feature Flags https://wiki.vg/Protocol#Feature_Flags
   def serialize({:feature_flags, flags}) do
-    Write.varint(0x0C) <> Write.varint(length(flags)) <> Enum.reduce(flags, "", fn id, acc -> acc <> Write.string(id) end)
+    Write.varint(0x0C) <> Write.varint(length(flags)) <> Write.list(flags, &Write.string/1)
   end
   # Update Tags https://wiki.vg/Protocol#Update_Tags
   def serialize({:update_tags, tags}) do
@@ -174,19 +170,17 @@ defmodule Amethyst.Server.Configuration do
   # Clientbound Known Packs https://wiki.vg/Protocol#Clientbound_Known_Packs
   def serialize({:clientbound_known_packs, packs}) do
     Write.varint(0x0E) <> Write.varint(length(packs)) <>
-    Enum.reduce(packs, "", fn {namespace, id, version}, acc -> acc <> Write.string(namespace) <> Write.string(id) <> Write.string(version) end)
+    Write.list(packs, fn {namespace, id, version} -> Write.string(namespace) <> Write.string(id) <> Write.string(version) end)
   end
   # Custom Report Details https://wiki.vg/Protocol#Custom_Report_Details
   def serialize({:custom_report_details, details}) do
     Write.varint(0x0F) <> Write.varint(length(details)) <>
-    Enum.reduce(details, "", fn {id, data}, acc -> acc <> Write.string(id) <> Write.string(data) end)
+    Write.list(details, fn {id, data} -> Write.string(id) <> Write.string(data) end)
   end
   # Server Links https://wiki.vg/Protocol#Server_Links_(configuration)
   def serialize({:server_links, links}) do
     Write.varint(0x10) <> Write.varint(length(links)) <>
-    Enum.reduce(links, "", fn {label, url}, acc ->
+    Write.list(links, fn {label, url} -> serialize_link_label(label) <> Write.string(url) end)
-      acc <> serialize_link_label(label) <> Write.string(url)
-    end)
   end
   def serialize(packet) do
     raise ArgumentError, "Tried serializing unknown packet #{inspect(packet)}"
@@ -196,8 +190,10 @@ defmodule Amethyst.Server.Configuration do
     acc <> Write.string(id) <> Write.varint(length(elements)) <> serialize_elements(elements)
   end
   defp serialize_elements(elements) do
-    Enum.reduce(elements, "", fn {id, ids}, acc -> acc <> Write.string(id) <> Write.varint(length(ids)) <>
+    Write.list(elements, fn {id, ids} ->
-      Enum.reduce(ids, "", fn id, acc -> acc <> Write.varint(id) end) end)
+      Write.string(id) <> Write.varint(length(ids)) <>
+      Write.list(ids, &Write.varint/1)
+    end)
   end
   defp serialize_link_label(:bug_report) do
     <<0x01>> <> Write.varint(0x00)
@@ -235,12 +231,40 @@ defmodule Amethyst.Server.Configuration do
 
   ## HANDLING
   @impl true
+  # Client Information https://wiki.vg/Protocol#Client_Information
+  def handle({:client_information, locale, v_dist, chat_mode, chat_colors, displayed_skin_parts, main_hand, text_filtering, allow_listing}, client, state) do
+    state = state |> Keyword.put(:locale, locale) |> Keyword.put(:view_dist, v_dist) |> Keyword.put(:chat_mode, chat_mode) |>
+      Keyword.put(:chat_colors, chat_colors) |> Keyword.put(:displayed_skin_parts, displayed_skin_parts) |> Keyword.put(:main_hand, main_hand) |>
+      Keyword.put(:text_filtering, text_filtering) |> Keyword.put(:allow_listing, allow_listing)
+    # TODO: Here we should create the game handling task for this player and give it
+    # this data.
+    transmit({:clientbound_plugin_message, "minecraft:brand", Write.string("amethyst")}, client)
+    transmit({:clientbound_known_packs, [{"minecraft", "core", "1.21"}]}, client)
+    {:ok, state}
+  end
+  # Serverbound Known Packs https://wiki.vg/Protocol#Serverbound_Known_Packs
+  def handle({:serverbound_known_packs, _packs}, client, state) do
+    # L + ratio + don't care + didn't ask + finish configuration
+    # TODO: we should send registries i think? does amethyst need to deal with vanilla registries at all? god only knows
+    transmit({:finish_configuration}, client)
+    {:ok, state}
+  end
+  # Acknowledge Finish Configuration https://wiki.vg/Protocol#Acknowledge_Finish_Configuration
+  def handle({:acknowledge_finish_configuration}, client, state) do
+    # TODO: All of this stuff should obviously not be hardcoded here
+    Amethyst.Server.Play.transmit({:login,
+      0, false, ["minecraft:overworld"], 0, 16, 16, false, true, true, 0,
+      "minecraft:overworld", <<0::64>>, :spectator, nil, false, true, nil, 0, false
+    }, client)
+    Amethyst.Server.Play.serve(client, state)
+  end
   # Serverbound Plugin Message https://wiki.vg/Protocol#Serverbound_Plugin_Message_(configuration)
   def handle({:serverbound_plugin_message, channel, data}, client, state) do
     handle_plugin_message(channel, data, client, state)
   end
-  def handle(tuple, _) do
+  def handle(tuple, state) do
     Logger.error("Unhandled but known packet #{elem(tuple, 0)}")
+    {:unhandled, state}
   end
   defp handle_plugin_message("minecraft:brand", data, client, state) do
     {[brand], ""} = Read.start(data) |> Read.string |> Read.stop

lib/servers/play.ex

@@ -0,0 +1,79 @@
+# Amethyst - An experimental Minecraft server written in Elixir.
+# Copyright (C) 2024 KodiCraft
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+defmodule Amethyst.Server.Play do
+  @moduledoc """
+  This module contains the logic for the Play stage of the server.
+  """
+  require Logger
+  use Amethyst.Server
+
+  alias Amethyst.Minecraft.Read
+  alias Amethyst.Minecraft.Write
+
+  @impl true
+  def init(state) do
+    state
+  end
+
+  ## DESERIALIZATION
+  @impl true
+
+  def deserialize(type, _) do
+    raise RuntimeError, "Got unknown packet type #{type}!"
+  end
+
+  ## SERIALIZATION
+  @impl true
+  # Login https://wiki.vg/Protocol#Login_(play)
+  def serialize({:login, eid, hardcore, dimensions,
+    max_players, view_distance, simulation_distance,
+    reduce_debug, enable_respawn_screen, limited_crafting,
+    dim_type, dim_name, hashed_seed, gamemode, prev_gm,
+    is_debug, is_flat, death_loc, portal_cooldown, enforce_chat}) when byte_size(hashed_seed) == 8 do
+      # TODO: This is a big unreadable slab of serialization which makes bugs really hard to catch, it needs a proper rework at some point
+      Write.varint(0x2B) <>
+      Write.int(eid) <> Write.bool(hardcore) <>
+      Write.varint(length(dimensions)) <> Write.list(dimensions, &Write.string/1) <>
+      Write.varint(max_players) <> Write.varint(view_distance) <> Write.varint(simulation_distance) <> Write.bool(reduce_debug) <>
+      Write.bool(enable_respawn_screen) <>
+      Write.bool(limited_crafting) <> Write.varint(dim_type) <> Write.string(dim_name) <>
+      hashed_seed <> Write.ubyte(gamemode_id(gamemode)) <> Write.byte(gamemode_id(prev_gm)) <>
+      Write.bool(is_debug) <> Write.bool(is_flat) <>
+      if(death_loc == nil, do: <<0::big-8>>, else: <<1::big-8>> <> Write.string(elem(death_loc, 0)) <> Write.position(elem(death_loc, 1))) <>
+      Write.varint(portal_cooldown) <> Write.bool(enforce_chat)
+    end
+  def serialize(packet) do
+    raise ArgumentError, "Tried serializing unknown packet #{inspect(packet)}"
+  end
+
+  ## HANDLING
+  @impl true
+  def handle(tuple, _, state) do
+    Logger.error("Unhandled but known packet #{elem(tuple, 0)}")
+    {:unhandled, state}
+  end
+
+  defp gamemode_id(gm) do
+    case gm do
+      nil -> -1
+      :survival -> 0
+      :creative -> 1
+      :adventure -> 2
+      :spectator -> 3
+    end
+  end
+end

lib/servers/status.ex

@@ -51,7 +51,7 @@ defmodule Amethyst.Server.Status do
     Write.varint(0x00) <> Write.string(data)
   end
   def serialize({:ping_response, payload}) do
-    Write.varint(0x01) <> <<payload::64-big-signed>>
+    Write.varint(0x01) <> Write.long(payload)
   end
   def serialize(packet) do
     raise ArgumentError, "Tried serializing unknown packet #{inspect(packet)}"

mix.exs

@@ -7,14 +7,21 @@ defmodule Amethyst.MixProject do
       version: "0.1.0",
       elixir: "~> 1.17",
       start_permanent: Mix.env() == :prod,
-      deps: deps()
+      deps: deps(),
+    
+      name: "Amethyst",
+      source_url: "https://git.colon-three.com/kodi/amethyst",
+      docs: [
+        main: "readme",
+        extras: ["README.md", "LICENSE.md"]
+      ]
     ]
   end
 
   # Run "mix help compile.app" to learn about applications.
   def application do
     [
-      extra_applications: [:logger],
+      extra_applications: [:logger, :public_key],
       mod: {Amethyst.Application, []}
     ]
   end
@@ -23,7 +30,8 @@ defmodule Amethyst.MixProject do
   defp deps do
     [
       {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
-      {:uuid, "~> 1.1"}
+      {:uuid, "~> 1.1"},
+      {:ex_doc, "~> 0.22", only: :dev, runtime: false}
     ]
   end
 end

mix.lock

@@ -1,7 +1,13 @@
 %{
   "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
   "credo": {:hex, :credo, "1.7.7", "771445037228f763f9b2afd612b6aa2fd8e28432a95dbbc60d8e03ce71ba4446", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "8bc87496c9aaacdc3f90f01b7b0582467b69b4bd2441fe8aae3109d843cc2f2e"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.41", "ab34711c9dc6212dda44fcd20ecb87ac3f3fce6f0ca2f28d4a00e4154f8cd599", [:mix], [], "hexpm", "a81a04c7e34b6617c2792e291b5a2e57ab316365c2644ddc553bb9ed863ebefa"},
+  "ex_doc": {:hex, :ex_doc, "0.34.2", "13eedf3844ccdce25cfd837b99bea9ad92c4e511233199440488d217c92571e8", [:mix], [{:earmark_parser, "~> 1.4.39", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "5ce5f16b41208a50106afed3de6a2ed34f4acfd65715b82a0b84b49d995f95c1"},
   "file_system": {:hex, :file_system, "1.0.0", "b689cc7dcee665f774de94b5a832e578bd7963c8e637ef940cd44327db7de2cd", [:mix], [], "hexpm", "6752092d66aec5a10e662aefeed8ddb9531d79db0bc145bb8c40325ca1d8536d"},
   "jason": {:hex, :jason, "1.4.3", "d3f984eeb96fe53b85d20e0b049f03e57d075b5acda3ac8d465c969a2536c17b", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "9a90e868927f7c777689baa16d86f4d0e086d968db5c05d917ccff6d443e58a3"},
+  "makeup": {:hex, :makeup, "1.1.2", "9ba8837913bdf757787e71c1581c21f9d2455f4dd04cfca785c70bbfff1a76a3", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cce1566b81fbcbd21eca8ffe808f33b221f9eee2cbc7a1706fc3da9ff18e6cac"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.16.2", "627e84b8e8bf22e60a2579dad15067c755531fea049ae26ef1020cad58fe9578", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "41193978704763f6bbe6cc2758b84909e62984c7752b3784bd3c218bb341706b"},
+  "makeup_erlang": {:hex, :makeup_erlang, "1.0.1", "c7f58c120b2b5aa5fd80d540a89fdf866ed42f1f3994e4fe189abebeab610839", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "8a89a1eeccc2d798d6ea15496a6e4870b75e014d1af514b1b71fa33134f57814"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.4.0", "51f9b613ea62cfa97b25ccc2c1b4216e81df970acd8e16e8d1bdc58fef21370d", [:mix], [], "hexpm", "9c565862810fb383e9838c1dd2d7d2c437b3d13b267414ba6af33e50d2d1cf28"},
   "uuid": {:hex, :uuid, "1.1.8", "e22fc04499de0de3ed1116b770c7737779f226ceefa0badb3592e64d5cfb4eb9", [:mix], [], "hexpm", "c790593b4c3b601f5dc2378baae7efaf5b3d73c4c6456ba85759905be792f2ac"},
 }