Continue rewrite

apps/amethyst/lib/apps/connection_handler.ex

@@ -34,7 +34,7 @@ alias ElixirSense.Log
   def start(socket, connstate, version) do
     {:ok, spawn(fn ->
       Process.set_label("ConnectionHandler for #{inspect(socket)}")
-      loop(socket, connstate, version)
+      loop(socket, connstate, version, %{})
     end)}
   end
 
@@ -42,12 +42,12 @@ alias ElixirSense.Log
   def start_link(socket, connstate, version) do
     {:ok, spawn_link(fn ->
       Process.set_label("ConnectionHandler for #{inspect(socket)}")
-      loop(socket, connstate, version)
+      loop(socket, connstate, version, %{})
     end)}
   end
 
-  @spec loop(:gen_tcp.socket(), atom(), pos_integer()) :: no_return()
+  @spec loop(:gen_tcp.socket(), atom(), pos_integer(), map()) :: no_return()
-  defp loop(socket, connstate, version) do
+  defp loop(socket, connstate, version, state) do
     receive do
       :closed ->
         Logger.info("Connection #{inspect(socket)} closed.")
@@ -57,38 +57,45 @@ alias ElixirSense.Log
         Process.exit(self(), :normal)
       {:set_state, newstate} ->
         Logger.debug("Switching to state #{newstate} from #{connstate}")
-        loop(socket, newstate, version)
+        loop(socket, newstate, version, state)
       {:set_version, newversion} ->
         Logger.debug("Switching to version #{newversion} from #{version}")
-        loop(socket, connstate, newversion)
+        loop(socket, connstate, newversion, state)
       {:send_packet, packet} ->
         Logger.debug("Sending packet #{inspect(packet)}")
         send_packet(socket, connstate, packet, version)
-        loop(socket, connstate, version)
+        loop(socket, connstate, version, state)
       after 0 ->
         receive do
           {:packet, id, data} ->
-            handle_packet(id, data, connstate, version)
+            state = handle_packet(id, data, connstate, version, state)
-            loop(socket, connstate, version)
+            loop(socket, connstate, version, state)
         end
     end
   end
 
-  defp handle_packet(id, data, connstate, version) do
+  defp handle_packet(id, data, connstate, version, state) do
     try do
       packet = connstate.deserialize(id, version, data)
-      case connstate.handle(packet, version) do
+      case connstate.handle(packet, version, state) do
-        :ok -> :ok
+        :ok -> state
         {:error, reason} ->
           Logger.error("Error handling packet with ID #{id} in state #{connstate}: #{reason}")
-          send(self(), {:disconnect, "Error handling packet #{id}: #{reason}"})
+          send(self(), {:disconnect, "Error handling packet #{id}:\n#{reason}"})
-        _ ->
+          state
-          Logger.warn("Unknown return value from handle_packet for packet #{id} in state #{connstate}")
+        newstate ->
+          if is_map(newstate) do
+            newstate
+          else
+            Logger.warning("State change to #{newstate} is not a map! Did you forget to return :ok?")
+            state
+          end
       end
     rescue
       e ->
         Logger.error("Error handling packet with ID #{id} in state #{connstate}: #{Exception.format(:error, e, __STACKTRACE__)}")
-        send(self(), {:disconnect, "Error handling packet #{id}: #{Exception.format(:error, e, __STACKTRACE__)}"})
+        send(self(), {:disconnect, "Error handling packet #{id}:\n#{e.message}"})
+        state
     end
   end
 

apps/amethyst/lib/data.ex

@@ -135,6 +135,10 @@ defmodule Amethyst.Minecraft.Write do
       v -> bool(true) <> callback.(v)
     end
   end
+
+  def nbt(value) do
+    Amethyst.NBT.Write.write_net(value)
+  end
 end
 
 defmodule Amethyst.Minecraft.Read do
@@ -259,4 +263,7 @@ defmodule Amethyst.Minecraft.Read do
     {[value], rest, :reversed} = string({[], data, :reversed})
     {[Jason.decode!(value) | acc], rest, :reversed}
   end
+  def raw({acc, data, :reversed}) do
+    {[data | acc], "", :reversed}
+  end
 end

apps/amethyst/lib/states/configuration.ex

@@ -0,0 +1,115 @@
+# 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.ConnectionState.Configuration do
+  require Amethyst.ConnectionState.Macros
+  alias Amethyst.ConnectionState.Macros
+
+  require Logger
+
+  @moduledoc """
+  This module contains the packets and logic for the Configuration state.
+  """
+  Macros.defpacket_clientbound :cookie_request, 0x00, 767, [identifier: :string]
+  Macros.defpacket_clientbound :clientbound_plugin_message, 0x01, 767, [channel: :string, data: :raw]
+  Macros.defpacket_clientbound :disconnect, 0x02, 767, [reason: :json]
+  Macros.defpacket_clientbound :finish_configuration, 0x03, 767, []
+  Macros.defpacket_clientbound :clientbound_keep_alive, 0x04, 767, [id: :long]
+  Macros.defpacket_clientbound :ping, 0x05, 767, [id: :int]
+  Macros.defpacket_clientbound :reset_chat, 0x06, 767, []
+  Macros.defpacket_clientbound :registry_data, 0x07, 767, [
+    id: :string,
+    entries: {:array, [
+      id: :string,
+      data: {:optional, :nbt}
+    ]}
+  ]
+  Macros.defpacket_clientbound :remove_resource_pack, 0x08, 767, [
+    uuid: {:optional, :uuid}
+  ]
+  Macros.defpacket_clientbound :add_resource_pack, 0x09, 767, [
+    uuid: :uuid,
+    url: :string,
+    hash: :string,
+    forced: :bool,
+    prompt_message: {:optional, :string}
+  ]
+  Macros.defpacket_clientbound :store_cookie, 0x0A, 767, [identifier: :string, payload: :byte_array]
+  Macros.defpacket_clientbound :transfer, 0x0B, 767, [host: :string, port: :varint]
+  Macros.defpacket_clientbound :feature_flags, 0x0C, 767, [flags: {:array, [flag: :string]}]
+  Macros.defpacket_clientbound :update_tags, 0x0D, 767, [
+    tags: {:array, [
+      registry: :string,
+      tags: {:array, [
+        name: :string,
+        entries: {:array, [id: :varint]}
+      ]}
+    ]}
+  ]
+  Macros.defpacket_clientbound :clientbound_known_packs, 0x0E, 767, [
+    packs: {:array, [
+      nameshape: :string,
+      id: :string,
+      version: :string
+    ]}
+  ]
+  Macros.defpacket_clientbound :custom_report_details, 0x0F, 767, [
+    details: {:array, [
+      title: :string,
+      desctioption: :string
+    ]}
+  ]
+  Macros.defpacket_clientbound :server_links, 0x10, 767, [
+    links: {:array, [
+      is_builtin: :bool,
+      label: :string,
+      url: :string
+    ]}
+  ]
+
+  Macros.defpacket_serverbound :client_information, 0x00, 767, [
+    locale: :string,
+    view_distance: :byte,
+    chat_mode: :varint,
+    chat_colors: :bool,
+    displayed_skin_parts: :byte,
+    main_hand: :varint,
+    text_filtering: :bool,
+    allow_server_listings: :bool
+  ]
+  Macros.defpacket_serverbound :cookie_response, 0x01, 767, [
+    key: :string,
+    payload: {:optional, :byte_array}
+  ]
+  Macros.defpacket_serverbound :serverbound_plugin_message, 0x02, 767, [channel: :string, data: :raw]
+  Macros.defpacket_serverbound :acknowledge_finish_configuration, 0x03, 767, []
+  Macros.defpacket_serverbound :serverbound_keep_alive, 0x04, 767, [id: :long]
+  Macros.defpacket_serverbound :pong, 0x05, 767, [id: :int]
+  Macros.defpacket_serverbound :resource_pack_response, 0x06, 767, [uuid: :uuid, result: :varint]
+  Macros.defpacket_serverbound :serverbound_known_packs, 0x07, 767, [
+    packs: {:array, [
+      namespace: :string,
+      id: :string,
+      version: :string
+    ]}
+  ]
+
+  def disconnect(reason) do
+    %{packet_type: :disconnect, reason: %{
+      "text" => reason
+    }}
+  end
+end

apps/amethyst/lib/states/handhsake.ex

@@ -31,7 +31,7 @@ defmodule Amethyst.ConnectionState.Handshake do
     next: :varint
   ]
 
-  def handle(%{packet_type: :handshake, version: 767, address: address, port: port, next: next}, 0) do
+  def handle(%{packet_type: :handshake, version: 767, address: address, port: port, next: next}, 0, _state) do
     Logger.debug("Received handshake for #{address}:#{port} with version 767")
     case next do
       1 ->

apps/amethyst/lib/states/login.ex

@@ -23,7 +23,7 @@ defmodule Amethyst.ConnectionState.Login do
   @moduledoc """
   This module contains the packets and logic for the Login state.
   """
-  Macros.defpacket_clientbound :disconnect, 0x00, 767, [reason: :json]
+  Macros.defpacket_clientbound :disconnect, 0x00, 767, [reason: :nbt]
   Macros.defpacket_clientbound :encryption_request, 0x01, 767, [
     server_id: :string,
     public_key: :byte_array,
@@ -60,10 +60,33 @@ defmodule Amethyst.ConnectionState.Login do
   Macros.defpacket_serverbound :login_acknowledged, 0x03, 767, []
   Macros.defpacket_serverbound :cookie_response, 0x04, 767, [identifier: :string, payload: {:optional, :byte_array}]
 
+  def handle(%{packet_type: :login_start, name: name, player_uuid: player_uuid}, 767, state) do
+    Logger.debug("Received login start for #{name} with UUID #{player_uuid}")
+    if Application.fetch_env!(:amethyst, :encryption) do
+      raise RuntimeError, "Encryption is not currently supported"
+    else
+      send(self(), {:send_packet, %{
+        packet_type: :login_success,
+        uuid: player_uuid,
+        username: name,
+        properties: [],
+        strict_error_handling: false
+      }})
+      :ok
+    end
+  end
+
+  def handle(%{packet_type: :login_acknowledged}, 767, _state) do
+    Logger.debug("Received login acknowledged")
+    send(self(), {:set_state, Amethyst.ConnectionState.Configuration})
+    :ok
+  end
+
   def disconnect(reason) do
-    %{packet_type: :disconnect, reason: %{
+    %{packet_type: :disconnect, reason:
-      "text" => "You have been disconnected:\n#{reason}",
+      {:compound, %{
-      "color" => "red"
+        "text" => {:string, reason}
       }}
+    }
   end
 end

apps/amethyst/lib/states/status.ex

@@ -29,7 +29,7 @@ defmodule Amethyst.ConnectionState.Status do
   Macros.defpacket_serverbound :status_request, 0x00, 767, []
   Macros.defpacket_serverbound :ping_request, 0x01, 767, [payload: :long]
 
-  def handle(%{packet_type: :status_request}, 767) do
+  def handle(%{packet_type: :status_request}, 767, _state) do
     Logger.debug("Received status request")
     send(self(), {:send_packet, %{
       packet_type: :status_response,
@@ -45,7 +45,7 @@ defmodule Amethyst.ConnectionState.Status do
     :ok
   end
 
-  def handle(%{packet_type: :ping_request, payload: payload}, 767) do
+  def handle(%{packet_type: :ping_request, payload: payload}, 767, _state) do
     Logger.debug("Received ping request")
     send(self(), {:send_packet, %{
       packet_type: :pong_response,