From 849e416c8d972511b57b164e22db9ab5f0ade918 Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Wed, 1 Sep 2021 07:14:38 -0400
Subject: [PATCH] Fix IPv6 scope issue in legacy forwarding too

---
 .../connection/backend/LoginSessionHandler.java  | 16 +++-------------
 .../backend/VelocityServerConnection.java        | 12 +++++++++++-
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/LoginSessionHandler.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/LoginSessionHandler.java
index 9f408310f..3bf611258 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/LoginSessionHandler.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/LoginSessionHandler.java
@@ -73,10 +73,10 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
   public boolean handle(LoginPluginMessage packet) {
     MinecraftConnection mc = serverConn.ensureConnected();
     VelocityConfiguration configuration = server.getConfiguration();
-    if (configuration.getPlayerInfoForwardingMode() == PlayerInfoForwarding.MODERN && packet
-        .getChannel().equals(VelocityConstants.VELOCITY_IP_FORWARDING_CHANNEL)) {
+    if (configuration.getPlayerInfoForwardingMode() == PlayerInfoForwarding.MODERN
+        && packet.getChannel().equals(VelocityConstants.VELOCITY_IP_FORWARDING_CHANNEL)) {
       ByteBuf forwardingData = createForwardingData(configuration.getForwardingSecret(),
-          cleanRemoteAddress(serverConn.getPlayer().getRemoteAddress()),
+          serverConn.getPlayerRemoteAddressAsString(),
           serverConn.getPlayer().getGameProfile());
       LoginPluginResponse response = new LoginPluginResponse(packet.getId(), true, forwardingData);
       mc.write(response);
@@ -145,16 +145,6 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
     }
   }
 
-  private static String cleanRemoteAddress(InetSocketAddress address) {
-    String addressString = address.getAddress().getHostAddress();
-    int ipv6ScopeIdx = addressString.indexOf('%');
-    if (ipv6ScopeIdx == -1) {
-      return addressString;
-    } else {
-      return addressString.substring(0, ipv6ScopeIdx);
-    }
-  }
-
   private static ByteBuf createForwardingData(byte[] hmacSecret, String address,
       GameProfile profile) {
     ByteBuf forwarded = Unpooled.buffer(2048);
diff --git a/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/VelocityServerConnection.java b/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/VelocityServerConnection.java
index 0c2dc6005..ed5fd7c3f 100644
--- a/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/VelocityServerConnection.java
+++ b/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/VelocityServerConnection.java
@@ -113,6 +113,16 @@ public class VelocityServerConnection implements MinecraftConnectionAssociation,
     return result;
   }
 
+  String getPlayerRemoteAddressAsString() {
+    final String addr = proxyPlayer.getRemoteAddress().getAddress().getHostAddress();
+    int ipv6ScopeIdx = addr.indexOf('%');
+    if (ipv6ScopeIdx == -1) {
+      return addr;
+    } else {
+      return addr.substring(0, ipv6ScopeIdx);
+    }
+  }
+
   private String createLegacyForwardingAddress(UnaryOperator<List<Property>> propertiesTransform) {
     // BungeeCord IP forwarding is simply a special injection after the "address" in the handshake,
     // separated by \0 (the null byte). In order, you send the original host, the player's IP, their
@@ -122,7 +132,7 @@ public class VelocityServerConnection implements MinecraftConnectionAssociation,
             .orElseGet(() -> registeredServer.getServerInfo().getAddress())
             .getHostString())
         .append('\0')
-        .append(proxyPlayer.getRemoteAddress().getAddress().getHostAddress())
+        .append(getPlayerRemoteAddressAsString())
         .append('\0')
         .append(proxyPlayer.getGameProfile().getUndashedId())
         .append('\0');