From 942908341a0ecfce5f910c05beec7378d5f71313 Mon Sep 17 00:00:00 2001
From: creeper123123321 <7974274+creeper123123321@users.noreply.github.com>
Date: Fri, 2 Jul 2021 19:45:52 -0300
Subject: [PATCH] fix fallback when using non-ipv6 compatible proxy

---
 .../com/viaversion/aas/handler/MinecraftHandler.kt  | 13 +++++++++++--
 .../kotlin/com/viaversion/aas/handler/state/Util.kt |  5 ++++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/main/kotlin/com/viaversion/aas/handler/MinecraftHandler.kt b/src/main/kotlin/com/viaversion/aas/handler/MinecraftHandler.kt
index 86ab5a8..01715f9 100644
--- a/src/main/kotlin/com/viaversion/aas/handler/MinecraftHandler.kt
+++ b/src/main/kotlin/com/viaversion/aas/handler/MinecraftHandler.kt
@@ -7,6 +7,7 @@ import com.viaversion.viaversion.exception.CancelCodecException
 import io.netty.channel.Channel
 import io.netty.channel.ChannelHandlerContext
 import io.netty.channel.SimpleChannelInboundHandler
+import io.netty.handler.proxy.ProxyConnectException
 import io.netty.handler.proxy.ProxyHandler
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -34,8 +35,10 @@ class MinecraftHandler(
     }
 
     override fun channelInactive(ctx: ChannelHandlerContext) {
-        other?.close()
-        data.state.onInactivated(this)
+        if (!failedProxy(ctx)) {
+            other?.close()
+            data.state.onInactivated(this)
+        }
         coroutineScope.cancel()
     }
 
@@ -47,7 +50,13 @@ class MinecraftHandler(
         other?.setAutoRead(ctx.channel().isWritable)
     }
 
+    private fun failedProxy(ctx: ChannelHandlerContext): Boolean {
+        // proxy connect future fails are handled in another part
+        return (ctx.channel().pipeline().get("proxy") as? ProxyHandler)?.connectFuture()?.isSuccess == false
+    }
+
     override fun exceptionCaught(ctx: ChannelHandlerContext, cause: Throwable) {
+        if (cause is ProxyConnectException && failedProxy(ctx)) return
         if (cause is CancelCodecException) return
         if (cause is ClosedChannelException) return
         mcLogger.debug("Exception: ", cause)
diff --git a/src/main/kotlin/com/viaversion/aas/handler/state/Util.kt b/src/main/kotlin/com/viaversion/aas/handler/state/Util.kt
index fff5cda..1c9faa4 100644
--- a/src/main/kotlin/com/viaversion/aas/handler/state/Util.kt
+++ b/src/main/kotlin/com/viaversion/aas/handler/state/Util.kt
@@ -16,6 +16,7 @@ import io.netty.bootstrap.Bootstrap
 import io.netty.channel.Channel
 import io.netty.channel.ChannelOption
 import io.netty.channel.socket.SocketChannel
+import io.netty.handler.proxy.ProxyHandler
 import io.netty.resolver.NoopAddressResolverGroup
 import kotlinx.coroutines.future.await
 import kotlinx.coroutines.withTimeoutOrNull
@@ -41,6 +42,7 @@ private suspend fun createBackChannel(
         .connect(socketAddr)
         .also { it.suspendAwait() }
         .channel()
+    (channel.pipeline().get("proxy") as? ProxyHandler)?.connectFuture()?.suspendAwait()
 
     mcLogger.info("+ ${handler.endRemoteAddress} -> $socketAddr")
     handler.data.backChannel = channel as SocketChannel
@@ -69,7 +71,8 @@ private suspend fun autoDetectVersion(handler: MinecraftHandler, socketAddr: Ine
 
             if (detectedProtocol != null
                 && detectedProtocol.version !in arrayOf(-1, -2)
-                && ProtocolVersion.isRegistered(detectedProtocol.version)) {
+                && ProtocolVersion.isRegistered(detectedProtocol.version)
+            ) {
                 handler.data.backServerVer = detectedProtocol.version
             } else {
                 handler.data.backServerVer = 47 // fallback 1.8