73 lines
2.4 KiB
Elixir
73 lines
2.4 KiB
Elixir
# Amethyst - An experimental Minecraft server written in Elixir.
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# Copyright (C) 2024 KodiCraft
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as
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# published by the Free Software Foundation, either version 3 of the
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# License, or (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Affero General Public License for more details.
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#
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# You should have received a copy of the GNU Affero General Public License
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# along with this program. If not, see <https://www.gnu.org/licenses/>.
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defmodule Amethyst.Server.Handshake do
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@moduledoc """
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This module contains the logic for the Handshake stage of the server.
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"""
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require Logger
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use Amethyst.Server
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alias Amethyst.Minecraft.Read
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@impl true
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def init(state) do
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state
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end
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## DESERIALIZATION
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@impl true
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# Handshake https://wiki.vg/Protocol#Handshake
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@spec deserialize(0, binary()) ::
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{:handshake, any(), any(), any(), :login | :status | :transfer}
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def deserialize(0x00, <<data::binary>>) do
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{[ver, addr, port, next], ""} = Read.start(data) |> Read.varint() |> Read.string() |> Read.ushort() |> Read.varint() |> Read.stop()
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next = case next do
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1 -> :status
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2 -> :login
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3 -> :transfer
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_ -> raise RuntimeError, "Client requested moving to an unknown state!"
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end
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{:handshake, ver, addr, port, next}
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end
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def deserialize(type, _) do
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raise RuntimeError, "Got unknown packet type #{type}!"
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end
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## SERIALIZATION
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@impl true
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def serialize(_) do
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raise RuntimeError, "No packets can be transmitted while still in the handshake stage!"
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end
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## HANDLING
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@impl true
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# Handshake https://wiki.vg/Protocol#Handshake
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@spec handle(any(), any(), any()) :: no_return()
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def handle({:handshake, 767, addr, port, next}, client, state) do
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Logger.info("Got handshake, version 767 on #{addr}:#{port}. Wants to move to #{next}")
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case next do
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:status -> Amethyst.Server.Status.serve(client, state)
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:login -> Amethyst.Server.Login.serve(client, state)
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_ -> raise RuntimeError, "Unhandled move to next mode #{next}"
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end
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end
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def handle(tuple, _, state) do
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Logger.error("Unhandled but known packet #{elem(tuple, 0)}")
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{:unhandled, state}
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end
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end
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