PaperMC/Spigot-API-Patches/0094-Add-legacy-ping-support-to-PaperServerListPingEvent.patch
Minecrell 16869992a8 Call PaperServerListPingEvent for legacy pings (#1057)
* Make the legacy ping handler more reliable

The Minecraft server often fails to respond to old ("legacy") pings
from old Minecraft versions using the protocol used before the switch
to Netty in Minecraft 1.7.

Due to packet fragmentation[1], we might not have all needed bytes
available when the LegacyPingHandler is called. In this case, it will
run into an error, remove the handler and continue using the modern
protocol.

This is unlikely to happen for the first two revisions of the legacy
ping protocol (used in Minecraft 1.5.x and older) since the request
consists of only one or two bytes, but happens frequently for the
last/third revision introduced in Minecraft 1.6.

It has much larger, variable packet sizes due to the inclusion of
the virtual host (the hostname/port used to connect to the server).

The solution[2] is simple: If we find more than two matching bytes,
we buffer the remaining bytes until we have enough to fully read and
respond to the request.

[1]: https://netty.io/wiki/user-guide-for-4.x.html#wiki-h3-11
[2]: https://netty.io/wiki/user-guide-for-4.x.html#wiki-h4-13

* Add legacy ping support to PaperServerListPingEvent

Add a new method to StatusClient check if the client is a legacy
client that does not support all of the features provided in the
event.
2018-03-30 13:00:01 -04:00

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1.2 KiB
Diff

From d013b9ea523646c41ecb86dbd32488d25073652b Mon Sep 17 00:00:00 2001
From: Minecrell <minecrell@minecrell.net>
Date: Wed, 11 Oct 2017 19:30:20 +0200
Subject: [PATCH] Add legacy ping support to PaperServerListPingEvent
Add a new method to StatusClient check if the client is a legacy
client that does not support all of the features provided in the
event.
diff --git a/src/main/java/com/destroystokyo/paper/network/StatusClient.java b/src/main/java/com/destroystokyo/paper/network/StatusClient.java
index 517d1523..ffda9f6a 100644
--- a/src/main/java/com/destroystokyo/paper/network/StatusClient.java
+++ b/src/main/java/com/destroystokyo/paper/network/StatusClient.java
@@ -10,4 +10,16 @@ import com.destroystokyo.paper.event.server.PaperServerListPingEvent;
*/
public interface StatusClient extends NetworkClient {
+ /**
+ * Returns whether the client is using an older version that doesn't
+ * support all of the features in {@link PaperServerListPingEvent}.
+ *
+ * <p>For Vanilla, this returns {@code true} for all clients older than 1.7.</p>
+ *
+ * @return {@code true} if the client is using legacy ping
+ */
+ default boolean isLegacy() {
+ return false;
+ }
+
}
--
2.16.2