From 17e6944daea8130e03903ccdfbf63f111c573849 Mon Sep 17 00:00:00 2001 From: Andrew Steinborn Date: Fri, 27 Sep 2019 22:37:42 -0400 Subject: [PATCH] Clean up HandshakeSessionHandler --- .../proxy/connection/ConnectionType.java | 10 -- .../client/HandshakeSessionHandler.java | 114 ++++++++++-------- .../forge/legacy/LegacyForgeConstants.java | 2 +- 3 files changed, 64 insertions(+), 62 deletions(-) diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/ConnectionType.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/ConnectionType.java index a69768946..b6d5fc75a 100644 --- a/proxy/src/main/java/com/velocitypowered/proxy/connection/ConnectionType.java +++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/ConnectionType.java @@ -34,14 +34,4 @@ public interface ConnectionType { */ GameProfile addGameProfileTokensIfRequired(GameProfile original, PlayerInfoForwarding forwardingType); - - /** - * Tests whether the hostname is the handshake packet is valid. - * - * @param address The address to check - * @return true if valid. - */ - default boolean checkServerAddressIsValid(String address) { - return true; - } } diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java index 8b8dca861..3d0fb39c1 100644 --- a/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java +++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java @@ -28,6 +28,7 @@ import net.kyori.text.TranslatableComponent; import net.kyori.text.format.TextColor; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; +import org.checkerframework.checker.nullness.qual.Nullable; public class HandshakeSessionHandler implements MinecraftSessionHandler { @@ -62,68 +63,79 @@ public class HandshakeSessionHandler implements MinecraftSessionHandler { public boolean handle(Handshake handshake) { InitialInboundConnection ic = new InitialInboundConnection(connection, cleanVhost(handshake.getServerAddress()), handshake); - switch (handshake.getNextStatus()) { + StateRegistry nextState = getStateForProtocol(handshake.getNextStatus()); + if (nextState == null) { + LOGGER.error("{} provided invalid protocol {}", ic, handshake.getNextStatus()); + connection.close(); + } else { + connection.setState(nextState); + connection.setProtocolVersion(handshake.getProtocolVersion()); + connection.setAssociation(ic); + + switch (nextState) { + case STATUS: + connection.setSessionHandler(new StatusSessionHandler(server, connection, ic)); + break; + case LOGIN: + this.handleLogin(handshake, ic); + break; + default: + // If you get this, it's a bug in Velocity. + throw new AssertionError("getStateForProtocol provided invalid state!"); + } + } + + return true; + } + + private static @Nullable StateRegistry getStateForProtocol(int status) { + switch (status) { case StateRegistry.STATUS_ID: - connection.setState(StateRegistry.STATUS); - connection.setProtocolVersion(handshake.getProtocolVersion()); - connection.setAssociation(ic); - connection.setSessionHandler(new StatusSessionHandler(server, connection, ic)); - return true; + return StateRegistry.STATUS; case StateRegistry.LOGIN_ID: - connection.setState(StateRegistry.LOGIN); - connection.setProtocolVersion(handshake.getProtocolVersion()); - - if (!ProtocolVersion.isSupported(handshake.getProtocolVersion())) { - connection.closeWith(Disconnect - .create(TranslatableComponent.of("multiplayer.disconnect.outdated_client"))); - return true; - } - - InetAddress address = ((InetSocketAddress) connection.getRemoteAddress()).getAddress(); - if (!server.getIpAttemptLimiter().attempt(address)) { - connection.closeWith( - Disconnect.create(TextComponent.of("You are logging in too fast, try again later."))); - return true; - } - - ConnectionType type = checkForForge(handshake); - connection.setType(type); - - // Make sure legacy forwarding is not in use on this connection. - if (!type.checkServerAddressIsValid(handshake.getServerAddress())) { - connection.closeWith(Disconnect - .create(TextComponent.of("Running Velocity behind Velocity is unsupported."))); - return true; - } - - // If the proxy is configured for modern forwarding, we must deny connections from 1.12.2 - // and lower, otherwise IP information will never get forwarded. - if (server.getConfiguration().getPlayerInfoForwardingMode() == PlayerInfoForwarding.MODERN - && handshake.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_13) < 0) { - connection.closeWith(Disconnect - .create(TextComponent.of("This server is only compatible with 1.13 and above."))); - return true; - } - - connection.setAssociation(ic); - server.getEventManager().fireAndForget(new ConnectionHandshakeEvent(ic)); - connection.setSessionHandler(new LoginSessionHandler(server, connection, ic)); - return true; + return StateRegistry.LOGIN; default: - LOGGER.error("{} provided invalid protocol {}", ic, handshake.getNextStatus()); - connection.close(); - return true; + return null; } } - private ConnectionType checkForForge(Handshake handshake) { + private void handleLogin(Handshake handshake, InitialInboundConnection ic) { + if (!ProtocolVersion.isSupported(handshake.getProtocolVersion())) { + connection.closeWith(Disconnect + .create(TranslatableComponent.of("multiplayer.disconnect.outdated_client"))); + return; + } + + InetAddress address = ((InetSocketAddress) connection.getRemoteAddress()).getAddress(); + if (!server.getIpAttemptLimiter().attempt(address)) { + connection.closeWith( + Disconnect.create(TextComponent.of("You are logging in too fast, try again later."))); + return; + } + + connection.setType(getHandshakeConnectionType(handshake)); + + // If the proxy is configured for modern forwarding, we must deny connections from 1.12.2 + // and lower, otherwise IP information will never get forwarded. + if (server.getConfiguration().getPlayerInfoForwardingMode() == PlayerInfoForwarding.MODERN + && handshake.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_13) < 0) { + connection.closeWith(Disconnect + .create(TextComponent.of("This server is only compatible with 1.13 and above."))); + return; + } + + server.getEventManager().fireAndForget(new ConnectionHandshakeEvent(ic)); + connection.setSessionHandler(new LoginSessionHandler(server, connection, ic)); + } + + private ConnectionType getHandshakeConnectionType(Handshake handshake) { // Determine if we're using Forge (1.8 to 1.12, may not be the case in 1.13). if (handshake.getServerAddress().endsWith(LegacyForgeConstants.HANDSHAKE_HOSTNAME_TOKEN) && handshake.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_13) < 0) { return ConnectionTypes.LEGACY_FORGE; } else { - // For later: See if we can determine Forge 1.13+ here, else this will need to be UNDETERMINED - // until later in the cycle (most likely determinable during the LOGIN phase) + // Note for future implementation: Forge 1.13+ identifies itself using a slightly different + // hostname token. return ConnectionTypes.VANILLA; } } diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/forge/legacy/LegacyForgeConstants.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/forge/legacy/LegacyForgeConstants.java index 43e25e65c..1a932c4f0 100644 --- a/proxy/src/main/java/com/velocitypowered/proxy/connection/forge/legacy/LegacyForgeConstants.java +++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/forge/legacy/LegacyForgeConstants.java @@ -6,7 +6,7 @@ package com.velocitypowered.proxy.connection.forge.legacy; public class LegacyForgeConstants { /** - * Clients attempting to connect to 1.8+ Forge servers will have + * Clients attempting to connect to 1.8-1.12.2 Forge servers will have * this token appended to the hostname in the initial handshake * packet. */