Files
OldSliceMC/patches/server/0013-Packet-obfuscation-and-reduction.patch
2021-11-30 12:54:40 -06:00

214 lines
9.9 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Cryptite <cryptite@gmail.com>
Date: Wed, 6 Oct 2021 11:03:01 -0500
Subject: [PATCH] Packet obfuscation and reduction
Minecraft is overzealous about packet updates for Entities. In Loka's case, we want to reduce as many unnecessary
packet updates as possible. This patch is likely to be updated over and over in terms of reducing packet sends.
In summary, this patch creates the concept of a "foreignValue" of a packet's data. We treat packets in two ways:
1) The packet sent to the player itself (the normal way). This always has all of the values as usual.
2) The packet data as seen by any other (foreign) players.
This patch adds the ability to set a "foreignValue" for an entity value so as to obfuscate data received by other players.
The current packets modified/obfuscated are the following:
# Health - Foreign Players will only receive packets that say the player is "alive or dead (max health or 0 health).
# This reduces the amount of health packet updates as well which is great for players in combat.
# Air Level - Foreign players will only ever see a player as having full oxygen
# Air level packets are sent PER-TICK, and as such a player with any change in air level will only spam themselves
# with packets instead of every single player within tracking distance
# Score - Foreign players will only see a player's score as 0 and will not update due to gathering xp orbs, etc.
diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundSetEntityDataPacket.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundSetEntityDataPacket.java
index 3e17f6131bf590d7c4a16b79c1c145cb4f565bc9..e1233fa58d068448d0accef7a7f6725fcb902848 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundSetEntityDataPacket.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundSetEntityDataPacket.java
@@ -22,6 +22,13 @@ public class ClientboundSetEntityDataPacket implements Packet<ClientGamePacketLi
}
+ // Slice start
+ public ClientboundSetEntityDataPacket(int id, List<SynchedEntityData.DataItem<?>> packedItems) {
+ this.id = id;
+ this.packedItems = packedItems;
+ }
+ // Slice end
+
public ClientboundSetEntityDataPacket(FriendlyByteBuf buf) {
this.id = buf.readVarInt();
this.packedItems = SynchedEntityData.unpack(buf);
diff --git a/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java b/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
index 4df12454001f0de5f358c88d876e34c35a736c42..72c74d2369a36b14f1103aa74b096f50e7990f4d 100644
--- a/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
+++ b/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
@@ -136,6 +136,11 @@ public class SynchedEntityData {
}
public <T> void set(EntityDataAccessor<T> key, T value) {
+ //Slice start
+ set(key, value, null);
+ }
+
+ public <T> void set(EntityDataAccessor<T> key, T value, @Nullable T foreignValue) { // Slice end
SynchedEntityData.DataItem<T> datawatcher_item = this.getItem(key);
if (ObjectUtils.notEqual(value, datawatcher_item.getValue())) {
@@ -145,6 +150,11 @@ public class SynchedEntityData {
this.isDirty = true;
}
+ // Slice start
+ if (foreignValue != null && ObjectUtils.notEqual(foreignValue, datawatcher_item.getForeignValue())) {
+ datawatcher_item.setForeignValue(foreignValue);
+ }
+ // Slice end
}
// CraftBukkit start - add method from above
@@ -200,6 +210,28 @@ public class SynchedEntityData {
return list;
}
+ // Slice start
+ @Nullable
+ public List<SynchedEntityData.DataItem<?>> packForeignDirty(List<DataItem<?>> unpackedData) {
+ List<SynchedEntityData.DataItem<?>> list = null;
+
+ for (DataItem<?> dataItem : unpackedData) {
+ DataItem<?> item = itemsById.get(dataItem.accessor.getId());
+ if (item.isDirty(true)) {
+ item.setForeignDirty(false);
+
+ if (list == null) {
+ list = Lists.newArrayList();
+ }
+
+ list.add(item.copy(true));
+ }
+ }
+
+ return list;
+ }
+ // Slice end
+
@Nullable
public List<SynchedEntityData.DataItem<?>> getAll() {
List<SynchedEntityData.DataItem<?>> list = null;
@@ -313,11 +345,14 @@ public class SynchedEntityData {
final EntityDataAccessor<T> accessor;
T value;
private boolean dirty;
+ @Nullable T foreignValue = null; // Slice
+ private boolean foreignDirty; // Slice
public DataItem(EntityDataAccessor<T> data, T value) {
this.accessor = data;
this.value = value;
this.dirty = true;
+ this.foreignDirty = true; // Slice
}
public EntityDataAccessor<T> getAccessor() {
@@ -343,5 +378,34 @@ public class SynchedEntityData {
public SynchedEntityData.DataItem<T> copy() {
return new SynchedEntityData.DataItem<>(this.accessor, this.accessor.getSerializer().copy(this.value));
}
+
+ // Slice start
+ public void setForeignValue(T foreignValue) {
+ this.foreignValue = foreignValue;
+ this.foreignDirty = true;
+ }
+
+ public @Nullable T getForeignValue() {
+ return foreignValue;
+ }
+
+ public boolean isDirty(boolean foreign) {
+ if (foreign) {
+ //There must be a foreign value in order for this to be dirty, otherwise we consider this a normal
+ //value and check the normal dirty flag.
+ return foreignValue == null || this.foreignDirty;
+ }
+
+ return this.dirty;
+ }
+
+ public void setForeignDirty(boolean dirty) {
+ this.foreignDirty = dirty;
+ }
+
+ public SynchedEntityData.DataItem<T> copy(boolean foreign) {
+ return new SynchedEntityData.DataItem<>(this.accessor, this.accessor.getSerializer().copy((foreign && this.foreignValue != null ? this.foreignValue : this.value)));
+ }
+ // Slice end
}
}
diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index 1c6bf5a3014beaf5f9c1c38aed4cf3225e50b8bb..6e9c5e210270647205499801b235849d20776156 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -368,7 +368,19 @@ public class ServerEntity {
SynchedEntityData datawatcher = this.entity.getEntityData();
if (datawatcher.isDirty()) {
- this.broadcastAndSend(new ClientboundSetEntityDataPacket(this.entity.getId(), datawatcher, false));
+ // Slice start
+ ClientboundSetEntityDataPacket dataPacket = new ClientboundSetEntityDataPacket(this.entity.getId(), datawatcher, false);
+ if (this.entity instanceof ServerPlayer serverPlayer) {
+ serverPlayer.connection.send(dataPacket);
+ }
+
+ //Get the packedData that the original packet has, and then determine if any of those are changed in
+ //the foreign version. If null, nothing to notify foreign trackers about.
+ List<SynchedEntityData.DataItem<?>> dirtyItems = datawatcher.packForeignDirty(dataPacket.getUnpackedData());
+ if (dirtyItems != null) {
+ this.broadcast(new ClientboundSetEntityDataPacket(this.entity.getId(), dirtyItems));
+ }
+ // Slice end
}
if (this.entity instanceof LivingEntity) {
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 78cb0786e741f8ef8611460dab64d0e2448fb6cf..587411322e75b08b7f6c2f18a22256ff9bf526ad 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -2953,7 +2953,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
if (event.isCancelled()) {
return;
}
- this.entityData.set(Entity.DATA_AIR_SUPPLY_ID, event.getAmount());
+ this.entityData.set(Entity.DATA_AIR_SUPPLY_ID, event.getAmount(), getMaxAirSupply()); // Slice
// CraftBukkit end
}
diff --git a/src/main/java/net/minecraft/world/entity/player/Player.java b/src/main/java/net/minecraft/world/entity/player/Player.java
index 51fd9bca61888861b58966a69cd1b63c742c44ca..3ed6e5d0c50c259c3df2b0cf84e2fb7ccf64def3 100644
--- a/src/main/java/net/minecraft/world/entity/player/Player.java
+++ b/src/main/java/net/minecraft/world/entity/player/Player.java
@@ -633,7 +633,7 @@ public abstract class Player extends LivingEntity {
public void increaseScore(int score) {
int j = this.getScore();
- this.entityData.set(Player.DATA_SCORE_ID, j + score);
+ this.entityData.set(Player.DATA_SCORE_ID, j + score, 0); // Slice
}
@Override
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 4ff4143f3a7cd89ef92f4b8882fa3e5addfe0f06..83495f9a7d92cd42c2f367891a0a04870a4a1577 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -2004,7 +2004,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
this.sendHealthUpdate();
}
}
- this.getHandle().getEntityData().set(LivingEntity.DATA_HEALTH_ID, (float) this.getScaledHealth());
+ this.getHandle().getEntityData().set(LivingEntity.DATA_HEALTH_ID, (float) this.getScaledHealth(), isDead() ? 0f : 20f); // Slice
this.getHandle().maxHealthCache = getMaxHealth();
}