From 6602dc655ed012b7604a315153e7e205eacf6416 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Thu, 15 Jul 2021 16:00:58 -0700
Subject: [PATCH] Catch desynced block breaks (#6193)

---
 .../server/Add-PlayerKickEvent-causes.patch   |  9 ++++++++
 ...t-allow-digging-into-unloaded-chunks.patch | 22 ++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/patches/server/Add-PlayerKickEvent-causes.patch b/patches/server/Add-PlayerKickEvent-causes.patch
index 273a708bd1..4d855ee296 100644
--- a/patches/server/Add-PlayerKickEvent-causes.patch
+++ b/patches/server/Add-PlayerKickEvent-causes.patch
@@ -209,6 +209,15 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
                              return;
                          }
                      }
+@@ -0,0 +0,0 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
+                 double blockDistanceSquared = this.player.distanceToSqr(blockposition.getX() + 0.5D, blockposition.getY() + 0.5D + 1.5D, blockposition.getZ() + 0.5D); // Copied from ServerPlayerGameMode#handleBlockBreakAction
+                 if (blockDistanceSquared > 40 * 40) {
+                     LOGGER.warn("{} tried to break a block {} square blocks away from their position", this.player.getScoreboardName(), blockDistanceSquared);
+-                    this.disconnect("Invalid block break distance");
++                    this.disconnect("Invalid block break distance", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION);
+                     return;
+                 }
+                 if (this.player.level.getChunkIfLoadedImmediately(blockposition.getX() >> 4, blockposition.getZ() >> 4) == null) {
 @@ -0,0 +0,0 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel());
          if (packet.getAction() == ServerboundResourcePackPacket.Action.DECLINED && this.server.isResourcePackRequired()) {
diff --git a/patches/server/Don-t-allow-digging-into-unloaded-chunks.patch b/patches/server/Don-t-allow-digging-into-unloaded-chunks.patch
index 49c3037f92..27d585d19f 100644
--- a/patches/server/Don-t-allow-digging-into-unloaded-chunks.patch
+++ b/patches/server/Don-t-allow-digging-into-unloaded-chunks.patch
@@ -34,6 +34,18 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
              if (iblockdata.isAir()) {
                  this.level.destroyBlockProgress(this.player.getId(), this.destroyPos, -1);
                  this.lastSentState = -1;
+@@ -0,0 +0,0 @@ public class ServerPlayerGameMode {
+         double d1 = this.player.getY() - ((double) pos.getY() + 0.5D) + 1.5D;
+         double d2 = this.player.getZ() - ((double) pos.getZ() + 0.5D);
+         double d3 = d0 * d0 + d1 * d1 + d2 * d2;
++        // Paper start
++        this.handleBlockBreakAction(pos, action, direction, worldHeight, d3);
++    }
++    public void handleBlockBreakAction(BlockPos pos, ServerboundPlayerActionPacket.Action action, Direction direction, int worldHeight, double d3) {
++        // Paper end
+ 
+         if (d3 > 36.0D) {
+             this.player.connection.send(new ClientboundBlockBreakAckPacket(pos, this.level.getBlockState(pos), action, false, "too far"));
 @@ -0,0 +0,0 @@ public class ServerPlayerGameMode {
                  this.player.connection.send(new ClientboundBlockBreakAckPacket(pos, this.level.getBlockState(pos), action, true, "stopped destroying"));
              } else if (action == ServerboundPlayerActionPacket.Action.ABORT_DESTROY_BLOCK) {
@@ -58,11 +70,19 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
              case START_DESTROY_BLOCK:
              case ABORT_DESTROY_BLOCK:
              case STOP_DESTROY_BLOCK:
+-                this.player.gameMode.handleBlockBreakAction(blockposition, packetplayinblockdig_enumplayerdigtype, packet.getDirection(), this.player.level.getMaxBuildHeight());
 +                // Paper start - Don't allow digging in unloaded chunks
++                double blockDistanceSquared = this.player.distanceToSqr(blockposition.getX() + 0.5D, blockposition.getY() + 0.5D + 1.5D, blockposition.getZ() + 0.5D); // Copied from ServerPlayerGameMode#handleBlockBreakAction
++                if (blockDistanceSquared > 40 * 40) {
++                    LOGGER.warn("{} tried to break a block {} square blocks away from their position", this.player.getScoreboardName(), blockDistanceSquared);
++                    this.disconnect("Invalid block break distance");
++                    return;
++                }
 +                if (this.player.level.getChunkIfLoadedImmediately(blockposition.getX() >> 4, blockposition.getZ() >> 4) == null) {
 +                    return;
 +                }
++                this.player.gameMode.handleBlockBreakAction(blockposition, packetplayinblockdig_enumplayerdigtype, packet.getDirection(), this.player.level.getMaxBuildHeight(), blockDistanceSquared);
 +                // Paper end - Don't allow digging in unloaded chunks
-                 this.player.gameMode.handleBlockBreakAction(blockposition, packetplayinblockdig_enumplayerdigtype, packet.getDirection(), this.player.level.getMaxBuildHeight());
                  return;
              default:
+                 throw new IllegalArgumentException("Invalid player action");