Paper/patches/server/0660-Add-PlayerKickEvent-causes.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Sat, 15 May 2021 20:30:45 -0700
Subject: [PATCH] Add PlayerKickEvent causes


diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index b8ffd95bbad81521b9f91e83f63188553c09d4bd..8aaf73d24ddff65c45eeb18d573e20fb8a1439a5 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -2117,7 +2117,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
                 ServerPlayer entityplayer = (ServerPlayer) iterator.next();
 
                 if (!whitelist.isWhiteListed(entityplayer.getGameProfile()) && !this.getPlayerList().isOp(entityplayer.getGameProfile())) { // Paper - Fix kicking ops when whitelist is reloaded (MC-171420)
-                    entityplayer.connection.disconnect(org.spigotmc.SpigotConfig.whitelistMessage); // Paper - use configurable message
+                    entityplayer.connection.disconnect(org.spigotmc.SpigotConfig.whitelistMessage, org.bukkit.event.player.PlayerKickEvent.Cause.WHITELIST); // Paper - use configurable message
                 }
             }
 
diff --git a/src/main/java/net/minecraft/server/commands/BanIpCommands.java b/src/main/java/net/minecraft/server/commands/BanIpCommands.java
index 144ca9280ce2fb19b4859e2c8299349ffd19f115..9f63d38853657cb01a4be0f1f7b613b2377a33ad 100644
--- a/src/main/java/net/minecraft/server/commands/BanIpCommands.java
+++ b/src/main/java/net/minecraft/server/commands/BanIpCommands.java
@@ -62,7 +62,7 @@ public class BanIpCommands {
             }
 
             for(ServerPlayer serverPlayer : list) {
-                serverPlayer.connection.disconnect(new TranslatableComponent("multiplayer.disconnect.ip_banned"));
+                serverPlayer.connection.disconnect(new TranslatableComponent("multiplayer.disconnect.ip_banned"), org.bukkit.event.player.PlayerKickEvent.Cause.IP_BANNED); // Paper - kick event cause
             }
 
             return list.size();
diff --git a/src/main/java/net/minecraft/server/commands/BanPlayerCommands.java b/src/main/java/net/minecraft/server/commands/BanPlayerCommands.java
index c8361cd6c75df09481612eee729e23435229c6bf..b6eb53d5647600963c038cf2ef1301aba66f524d 100644
--- a/src/main/java/net/minecraft/server/commands/BanPlayerCommands.java
+++ b/src/main/java/net/minecraft/server/commands/BanPlayerCommands.java
@@ -43,7 +43,7 @@ public class BanPlayerCommands {
                 source.sendSuccess(new TranslatableComponent("commands.ban.success", ComponentUtils.getDisplayName(gameProfile), userBanListEntry.getReason()), true);
                 ServerPlayer serverPlayer = source.getServer().getPlayerList().getPlayer(gameProfile.getId());
                 if (serverPlayer != null) {
-                    serverPlayer.connection.disconnect(new TranslatableComponent("multiplayer.disconnect.banned"));
+                    serverPlayer.connection.disconnect(new TranslatableComponent("multiplayer.disconnect.banned"), org.bukkit.event.player.PlayerKickEvent.Cause.BANNED); // Paper - kick event cause
                 }
             }
         }
diff --git a/src/main/java/net/minecraft/server/commands/KickCommand.java b/src/main/java/net/minecraft/server/commands/KickCommand.java
index 708ac03d5a849bf09c49547306e4a8c5a5ef8d91..5a8df368a4a25839cd4ac9be6972da2ee4875d85 100644
--- a/src/main/java/net/minecraft/server/commands/KickCommand.java
+++ b/src/main/java/net/minecraft/server/commands/KickCommand.java
@@ -23,7 +23,7 @@ public class KickCommand {
 
     private static int kickPlayers(CommandSourceStack source, Collection<ServerPlayer> targets, Component reason) {
         for(ServerPlayer serverPlayer : targets) {
-            serverPlayer.connection.disconnect(reason);
+            serverPlayer.connection.disconnect(reason, org.bukkit.event.player.PlayerKickEvent.Cause.KICK_COMMAND); // Paper - kick event cause
             source.sendSuccess(new TranslatableComponent("commands.kick.success", serverPlayer.getDisplayName(), reason), true);
         }
 
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 50797b32b71b2c8a73f34313021457b27fc90660..7ad1b8b836d692b1168609e96e4eb72e037be4c9 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -318,7 +318,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         if (this.clientIsFloating && !this.player.isSleeping() && !this.player.isPassenger()) {
             if (++this.aboveGroundTickCount > 80) {
                 ServerGamePacketListenerImpl.LOGGER.warn("{} was kicked for floating too long!", this.player.getName().getString());
-                this.disconnect(com.destroystokyo.paper.PaperConfig.flyingKickPlayerMessage); // Paper - use configurable kick message
+                this.disconnect(com.destroystokyo.paper.PaperConfig.flyingKickPlayerMessage, org.bukkit.event.player.PlayerKickEvent.Cause.FLYING_PLAYER); // Paper - use configurable kick message & kick event cause
                 return;
             }
         } else {
@@ -337,7 +337,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
             if (this.clientVehicleIsFloating && this.player.getRootVehicle().getControllingPassenger() == this.player) {
                 if (++this.aboveGroundVehicleTickCount > 80) {
                     ServerGamePacketListenerImpl.LOGGER.warn("{} was kicked for floating a vehicle too long!", this.player.getName().getString());
-                    this.disconnect(com.destroystokyo.paper.PaperConfig.flyingKickVehicleMessage); // Paper - use configurable kick message
+                    this.disconnect(com.destroystokyo.paper.PaperConfig.flyingKickVehicleMessage, org.bukkit.event.player.PlayerKickEvent.Cause.FLYING_VEHICLE); // Paper - use configurable kick message & kick event cause
                     return;
                 }
             } else {
@@ -359,7 +359,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         if (this.keepAlivePending) {
             if (!this.processedDisconnect && elapsedTime >= KEEPALIVE_LIMIT) { // check keepalive limit, don't fire if already disconnected
                 ServerGamePacketListenerImpl.LOGGER.warn("{} was kicked due to keepalive timeout!", this.player.getScoreboardName()); // more info
-                this.disconnect(new TranslatableComponent("disconnect.timeout", new Object[0]));
+                this.disconnect(new TranslatableComponent("disconnect.timeout", new Object[0]), org.bukkit.event.player.PlayerKickEvent.Cause.TIMEOUT); // Paper - kick event cause
             }
         } else {
             if (elapsedTime >= 15000L) { // 15 seconds
@@ -389,7 +389,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
 
         if (this.player.getLastActionTime() > 0L && this.server.getPlayerIdleTimeout() > 0 && Util.getMillis() - this.player.getLastActionTime() > (long) (this.server.getPlayerIdleTimeout() * 1000 * 60)) {
             this.player.resetLastActionTime(); // CraftBukkit - SPIGOT-854
-            this.disconnect(new TranslatableComponent("multiplayer.disconnect.idling"));
+            this.disconnect(new TranslatableComponent("multiplayer.disconnect.idling"), org.bukkit.event.player.PlayerKickEvent.Cause.IDLING); // Paper - kick event cause
         }
 
     }
@@ -414,14 +414,22 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
 
     public void disconnect(String s) {
         // Paper start
-        this.disconnect(PaperAdventure.LEGACY_SECTION_UXRC.deserialize(s));
+        this.disconnect(PaperAdventure.LEGACY_SECTION_UXRC.deserialize(s), org.bukkit.event.player.PlayerKickEvent.Cause.UNKNOWN);
+    }
+
+    public void disconnect(String s, PlayerKickEvent.Cause cause) {
+        this.disconnect(PaperAdventure.LEGACY_SECTION_UXRC.deserialize(s), cause);
     }
 
     public void disconnect(final Component reason) {
-        this.disconnect(PaperAdventure.asAdventure(reason));
+        this.disconnect(PaperAdventure.asAdventure(reason), org.bukkit.event.player.PlayerKickEvent.Cause.UNKNOWN);
+    }
+
+    public void disconnect(final Component reason, PlayerKickEvent.Cause cause) {
+        this.disconnect(PaperAdventure.asAdventure(reason), cause);
     }
 
-    public void disconnect(net.kyori.adventure.text.Component reason) {
+    public void disconnect(net.kyori.adventure.text.Component reason, org.bukkit.event.player.PlayerKickEvent.Cause cause) {
         // Paper end
         // CraftBukkit start - fire PlayerKickEvent
         if (this.processedDisconnect) {
@@ -429,7 +437,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         }
         net.kyori.adventure.text.Component leaveMessage = net.kyori.adventure.text.Component.translatable("multiplayer.player.left", net.kyori.adventure.text.format.NamedTextColor.YELLOW, this.player.getBukkitEntity().displayName()); // Paper - Adventure
 
-        PlayerKickEvent event = new PlayerKickEvent(this.player.getBukkitEntity(), reason, leaveMessage); // Paper - Adventure
+        PlayerKickEvent event = new PlayerKickEvent(this.player.getBukkitEntity(), reason, leaveMessage, cause); // Paper - Adventure & kick event reason
 
         if (this.cserver.getServer().isRunning()) {
             this.cserver.getPluginManager().callEvent(event);
@@ -506,7 +514,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
     public void handleMoveVehicle(ServerboundMoveVehiclePacket packet) {
         PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel());
         if (ServerGamePacketListenerImpl.containsInvalidValues(packet.getX(), packet.getY(), packet.getZ(), packet.getYRot(), packet.getXRot())) {
-            this.disconnect(new TranslatableComponent("multiplayer.disconnect.invalid_vehicle_movement"));
+            this.disconnect(new TranslatableComponent("multiplayer.disconnect.invalid_vehicle_movement"), org.bukkit.event.player.PlayerKickEvent.Cause.INVALID_VEHICLE_MOVEMENT); // Paper - kick event cause
         } else {
             Entity entity = this.player.getRootVehicle();
 
@@ -752,13 +760,13 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         // PlayerConnectionUtils.ensureMainThread(packetplayintabcomplete, this, this.player.getWorldServer()); // Paper - run this async
         // CraftBukkit start
         if (this.chatSpamTickCount.addAndGet(com.destroystokyo.paper.PaperConfig.tabSpamIncrement) > com.destroystokyo.paper.PaperConfig.tabSpamLimit && !this.server.getPlayerList().isOp(this.player.getGameProfile())) { // Paper start - split and make configurable
-            server.scheduleOnMain(() -> this.disconnect(new TranslatableComponent("disconnect.spam", new Object[0]))); // Paper
+            server.scheduleOnMain(() -> this.disconnect(new TranslatableComponent("disconnect.spam", new Object[0]), org.bukkit.event.player.PlayerKickEvent.Cause.SPAM)); // Paper - kick event cause
             return;
         }
         // Paper start
         String str = packet.getCommand(); int index = -1;
         if (str.length() > 64 && ((index = str.indexOf(' ')) == -1 || index >= 64)) {
-            server.scheduleOnMain(() -> this.disconnect(new TranslatableComponent("disconnect.spam", new Object[0]))); // Paper
+            server.scheduleOnMain(() -> this.disconnect(new TranslatableComponent("disconnect.spam", new Object[0]), org.bukkit.event.player.PlayerKickEvent.Cause.SPAM)); // Paper - kick event cause
             return;
         }
         // Paper end
@@ -910,7 +918,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         // Paper start - validate pick item position
         if (!(packet.getSlot() >= 0 && packet.getSlot() < this.player.getInventory().items.size())) {
             ServerGamePacketListenerImpl.LOGGER.warn("{} tried to set an invalid carried item", this.player.getName().getString());
-            this.disconnect("Invalid hotbar selection (Hacking?)");
+            this.disconnect("Invalid hotbar selection (Hacking?)", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION); // Paper - kick event cause
             return;
         }
         this.player.getInventory().pickSlot(packet.getSlot()); // Paper - Diff above if changed
@@ -1075,7 +1083,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                 int byteLength = testString.getBytes(java.nio.charset.StandardCharsets.UTF_8).length;
                 if (byteLength > 256 * 4) {
                     ServerGamePacketListenerImpl.LOGGER.warn(this.player.getScoreboardName() + " tried to send a book with with a page too large!");
-                    server.scheduleOnMain(() -> this.disconnect("Book too large!"));
+                    server.scheduleOnMain(() -> this.disconnect("Book too large!", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION)); // Paper - kick event cause
                     return;
                 }
                 byteTotal += byteLength;
@@ -1098,14 +1106,14 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
 
             if (byteTotal > byteAllowed) {
                 ServerGamePacketListenerImpl.LOGGER.warn(this.player.getScoreboardName() + " tried to send too large of a book. Book Size: " + byteTotal + " - Allowed:  "+ byteAllowed + " - Pages: " + pageList.size());
-                server.scheduleOnMain(() -> this.disconnect("Book too large!"));
+                server.scheduleOnMain(() -> this.disconnect("Book too large!", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION)); // Paper - kick event cause
                 return;
             }
         }
         // Paper end
         // CraftBukkit start
         if (this.lastBookTick + 20 > MinecraftServer.currentTick) {
-            this.disconnect("Book edited too quickly!");
+            this.disconnect("Book edited too quickly!", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION); // Paper - kick event cause
             return;
         }
         this.lastBookTick = MinecraftServer.currentTick;
@@ -1229,7 +1237,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
     public void handleMovePlayer(ServerboundMovePlayerPacket packet) {
         PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel());
         if (ServerGamePacketListenerImpl.containsInvalidValues(packet.getX(0.0D), packet.getY(0.0D), packet.getZ(0.0D), packet.getYRot(0.0F), packet.getXRot(0.0F))) {
-            this.disconnect(new TranslatableComponent("multiplayer.disconnect.invalid_player_movement"));
+            this.disconnect(new TranslatableComponent("multiplayer.disconnect.invalid_player_movement"), org.bukkit.event.player.PlayerKickEvent.Cause.INVALID_PLAYER_MOVEMENT); // Paper - kick event cause
         } else {
             ServerLevel worldserver = this.player.getLevel();
 
@@ -1656,7 +1664,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                         this.dropCount++;
                         if (this.dropCount >= 20) {
                             ServerGamePacketListenerImpl.LOGGER.warn(this.player.getScoreboardName() + " dropped their items too quickly!");
-                            this.disconnect("You dropped your items too quickly (Hacking?)");
+                            this.disconnect("You dropped your items too quickly (Hacking?)", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION); // Paper - kick event cause
                             return;
                         }
                     }
@@ -1875,7 +1883,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         PacketUtils.ensureRunningOnSameThread(packet, this, this.player.getLevel());
         if (packet.getAction() == ServerboundResourcePackPacket.Action.DECLINED && this.server.isResourcePackRequired()) {
             ServerGamePacketListenerImpl.LOGGER.info("Disconnecting {} due to resource pack rejection", this.player.getName());
-            this.disconnect(new TranslatableComponent("multiplayer.requiredTexturePrompt.disconnect"));
+            this.disconnect(new TranslatableComponent("multiplayer.requiredTexturePrompt.disconnect"), org.bukkit.event.player.PlayerKickEvent.Cause.RESOURCE_PACK_REJECTION); // Paper - add cause
         }
         // Paper start
         PlayerResourcePackStatusEvent.Status packStatus = PlayerResourcePackStatusEvent.Status.values()[packet.action.ordinal()];
@@ -1980,7 +1988,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
             this.player.resetLastActionTime();
         } else {
             ServerGamePacketListenerImpl.LOGGER.warn("{} tried to set an invalid carried item", this.player.getName().getString());
-            this.disconnect("Invalid hotbar selection (Hacking?)"); // CraftBukkit
+            this.disconnect("Invalid hotbar selection (Hacking?)", org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_ACTION); // CraftBukkit // Paper - kick event cause
         }
     }
 
@@ -1996,7 +2004,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
 
         for (int i = 0; i < s.length(); ++i) {
             if (!SharedConstants.isAllowedChatCharacter(s.charAt(i))) {
-                this.disconnect(new TranslatableComponent("multiplayer.disconnect.illegal_characters"));
+                this.disconnect(new TranslatableComponent("multiplayer.disconnect.illegal_characters"), org.bukkit.event.player.PlayerKickEvent.Cause.ILLEGAL_CHARACTERS); // Paper - add cause
                 return;
             }
         }
@@ -2069,7 +2077,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                     Waitable waitable = new Waitable() {
                         @Override
                         protected Object evaluate() {
-                            ServerGamePacketListenerImpl.this.disconnect(new TranslatableComponent("disconnect.spam"));
+                            ServerGamePacketListenerImpl.this.disconnect(new TranslatableComponent("disconnect.spam"), org.bukkit.event.player.PlayerKickEvent.Cause.SPAM); // Paper - kick event cause
                             return null;
                         }
                     };
@@ -2084,7 +2092,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                         throw new RuntimeException(e);
                     }
                 } else {
-                    this.disconnect(new TranslatableComponent("disconnect.spam"));
+                    this.disconnect(new TranslatableComponent("disconnect.spam"), org.bukkit.event.player.PlayerKickEvent.Cause.SPAM); // Paper - kick event cause
                 }
                 // CraftBukkit end
             }
@@ -2357,7 +2365,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         // Spigot Start
         if ( entity == this.player && !this.player.isSpectator() )
         {
-            this.disconnect( "Cannot interact with self!" );
+            this.disconnect( "Cannot interact with self!", org.bukkit.event.player.PlayerKickEvent.Cause.SELF_INTERACTION ); // Paper - add cause
             return;
         }
         // Spigot End
@@ -2452,7 +2460,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                             }
                             // CraftBukkit end
                         } else {
-                            ServerGamePacketListenerImpl.this.disconnect(new TranslatableComponent("multiplayer.disconnect.invalid_entity_attacked"));
+                            ServerGamePacketListenerImpl.this.disconnect(new TranslatableComponent("multiplayer.disconnect.invalid_entity_attacked"),  org.bukkit.event.player.PlayerKickEvent.Cause.INVALID_ENTITY_ATTACKED); // Paper - add cause
                             ServerGamePacketListenerImpl.LOGGER.warn("Player {} tried to attack an invalid entity", ServerGamePacketListenerImpl.this.player.getName().getString());
                         }
                     }
@@ -2858,7 +2866,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         // Paper start
         if (!org.bukkit.Bukkit.isPrimaryThread()) {
             if (recipeSpamPackets.addAndGet(com.destroystokyo.paper.PaperConfig.autoRecipeIncrement) > com.destroystokyo.paper.PaperConfig.autoRecipeLimit) {
-                server.scheduleOnMain(() -> this.disconnect(new TranslatableComponent("disconnect.spam", new Object[0]))); // Paper
+                server.scheduleOnMain(() -> this.disconnect(new TranslatableComponent("disconnect.spam", new Object[0]), org.bukkit.event.player.PlayerKickEvent.Cause.SPAM)); // Paper - kick event cause
                 return;
             }
         }
@@ -3046,7 +3054,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
         } else if (!this.isSingleplayerOwner()) {
             // Paper start - This needs to be handled on the main thread for plugins
             server.submit(() -> {
-            this.disconnect(new TranslatableComponent("disconnect.timeout"));
+            this.disconnect(new TranslatableComponent("disconnect.timeout"), org.bukkit.event.player.PlayerKickEvent.Cause.TIMEOUT); // Paper - kick event cause
             });
             // Paper end
         }
@@ -3092,7 +3100,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                 }
             } catch (Exception ex) {
                 ServerGamePacketListenerImpl.LOGGER.error("Couldn\'t register custom payload", ex);
-                this.disconnect("Invalid payload REGISTER!");
+                this.disconnect("Invalid payload REGISTER!", org.bukkit.event.player.PlayerKickEvent.Cause.INVALID_PAYLOAD); // Paper - kick event cause
             }
         } else if (packet.identifier.equals(CUSTOM_UNREGISTER)) {
             try {
@@ -3102,7 +3110,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                 }
             } catch (Exception ex) {
                 ServerGamePacketListenerImpl.LOGGER.error("Couldn\'t unregister custom payload", ex);
-                this.disconnect("Invalid payload UNREGISTER!");
+                this.disconnect("Invalid payload UNREGISTER!", org.bukkit.event.player.PlayerKickEvent.Cause.INVALID_PAYLOAD); // Paper - kick event cause
             }
         } else {
             try {
@@ -3120,7 +3128,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
                 this.cserver.getMessenger().dispatchIncomingMessage(this.player.getBukkitEntity(), packet.identifier.toString(), data);
             } catch (Exception ex) {
                 ServerGamePacketListenerImpl.LOGGER.error("Couldn\'t dispatch custom payload", ex);
-                this.disconnect("Invalid custom payload!");
+                this.disconnect("Invalid custom payload!", org.bukkit.event.player.PlayerKickEvent.Cause.INVALID_PAYLOAD); // Paper - kick event cause
             }
         }
 
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 5d7d1372e012ce609073eecea83232b085c6c404..ee139c746328fcff67b1ee75629dbee0dd547fed 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -719,7 +719,7 @@ public abstract class PlayerList {
         while (iterator.hasNext()) {
             entityplayer = (ServerPlayer) iterator.next();
             this.save(entityplayer); // CraftBukkit - Force the player's inventory to be saved
-            entityplayer.connection.disconnect(new TranslatableComponent("multiplayer.disconnect.duplicate_login", new Object[0]));
+            entityplayer.connection.disconnect(new TranslatableComponent("multiplayer.disconnect.duplicate_login", new Object[0]), org.bukkit.event.player.PlayerKickEvent.Cause.DUPLICATE_LOGIN); // Paper - kick event cause
         }
 
         // Instead of kicking then returning, we need to store the kick reason
@@ -1350,8 +1350,8 @@ public abstract class PlayerList {
         // Paper end
         // CraftBukkit start - disconnect safely
         for (ServerPlayer player : this.players) {
-            if (isRestarting) player.connection.disconnect(org.spigotmc.SpigotConfig.restartMessage); else // Paper
-            player.connection.disconnect(this.server.server.shutdownMessage()); // CraftBukkit - add custom shutdown message // Paper - Adventure
+            if (isRestarting) player.connection.disconnect(org.spigotmc.SpigotConfig.restartMessage, org.bukkit.event.player.PlayerKickEvent.Cause.UNKNOWN); else // Paper - kick event cause (cause is never used here)
+            player.connection.disconnect(this.server.server.shutdownMessage(), org.bukkit.event.player.PlayerKickEvent.Cause.UNKNOWN); // CraftBukkit - add custom shutdown message // Paper - Adventure & KickEventCause (cause is never used here)
         }
         // CraftBukkit end
 
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index f623aad54714449d0c2793d68adbf8cfb1f640a2..f23dbb48e051d69ecae408080a30a1ebe8c32a2b 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -509,16 +509,21 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         org.spigotmc.AsyncCatcher.catchOp("player kick"); // Spigot
         if (this.getHandle().connection == null) return;
 
-        this.getHandle().connection.disconnect(message == null ? "" : message);
+        this.getHandle().connection.disconnect(message == null ? "" : message, org.bukkit.event.player.PlayerKickEvent.Cause.PLUGIN); // Paper - kick event cause
     }
 
     // Paper start
     @Override
     public void kick(final net.kyori.adventure.text.Component message) {
+        kick(message, org.bukkit.event.player.PlayerKickEvent.Cause.PLUGIN);
+    }
+
+    @Override
+    public void kick(net.kyori.adventure.text.Component message, org.bukkit.event.player.PlayerKickEvent.Cause cause) {
         org.spigotmc.AsyncCatcher.catchOp("player kick");
         final ServerGamePacketListenerImpl connection = this.getHandle().connection;
         if (connection != null) {
-            connection.disconnect(message == null ? net.kyori.adventure.text.Component.empty() : message);
+            connection.disconnect(message == null ? net.kyori.adventure.text.Component.empty() : message, cause);
         }
     }
 
diff --git a/src/main/java/org/spigotmc/RestartCommand.java b/src/main/java/org/spigotmc/RestartCommand.java
index 92d97a5810a379b427a99b4c63fb9844d823a84f..160115bf8a153ff981ba308599d22c4c08026fb6 100644
--- a/src/main/java/org/spigotmc/RestartCommand.java
+++ b/src/main/java/org/spigotmc/RestartCommand.java
@@ -74,7 +74,7 @@ public class RestartCommand extends Command
             // Kick all players
             for ( ServerPlayer p : com.google.common.collect.ImmutableList.copyOf( MinecraftServer.getServer().getPlayerList().players ) )
             {
-                p.connection.disconnect(SpigotConfig.restartMessage);
+                p.connection.disconnect(SpigotConfig.restartMessage, org.bukkit.event.player.PlayerKickEvent.Cause.RESTART_COMMAND); // Paper - kick event reason (cause is never used))
             }
             // Give the socket a chance to send the packets
             try