From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Caleb Bassham Date: Fri, 28 Sep 2018 02:32:19 -0500 Subject: [PATCH] Call player spectator target events and improve implementation Use a proper teleport for teleporting to entities in different worlds. Implementation improvements authored by Spottedleaf Validate that the target entity is valid and deny spectate requests from frozen players. Also, make sure the entity is spawned to the client before sending the camera packet. If the entity isn't spawned clientside when it receives the camera packet, then the client will not spectate the target entity. Co-authored-by: Spottedleaf diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java index 75419c866641ab654349cde6ca3fbdef701dd8d9..92139b271eb6c305787662ef8c7d221fb42296f7 100644 --- a/src/main/java/net/minecraft/server/level/ServerPlayer.java +++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java @@ -1818,14 +1818,58 @@ public class ServerPlayer extends Player implements ContainerListener { } public void setCamera(Entity entity) { + // Paper start - Add PlayerStartSpectatingEntityEvent and PlayerStopSpectatingEntity Event and improve implementation Entity entity1 = this.getCamera(); - this.camera = (Entity) (entity == null ? this : entity); - if (entity1 != this.camera) { - this.connection.send(new ClientboundSetCameraPacket(this.camera)); - this.connection.a(this.camera.getX(), this.camera.getY(), this.camera.getZ(), this.yRot, this.xRot, TeleportCause.SPECTATE); // CraftBukkit + if (entity == null) { + entity = this; } + if (entity1 == entity) return; // new spec target is the current spec target + + if (entity == this) { + com.destroystokyo.paper.event.player.PlayerStopSpectatingEntityEvent playerStopSpectatingEntityEvent = new com.destroystokyo.paper.event.player.PlayerStopSpectatingEntityEvent(this.getBukkitEntity(), entity1.getBukkitEntity()); + + if (!playerStopSpectatingEntityEvent.callEvent()) { + return; + } + } else { + com.destroystokyo.paper.event.player.PlayerStartSpectatingEntityEvent playerStartSpectatingEntityEvent = new com.destroystokyo.paper.event.player.PlayerStartSpectatingEntityEvent(this.getBukkitEntity(), entity1.getBukkitEntity(), entity.getBukkitEntity()); + + if (!playerStartSpectatingEntityEvent.callEvent()) { + return; + } + } + // Validate + if (entity != this) { + if (entity.removed || entity.shouldBeRemoved || !entity.valid || entity.level == null) { + MinecraftServer.LOGGER.info("Blocking player " + this.toString() + " from spectating invalid entity " + entity.toString()); + return; + } + if (this.isImmobile()) { + // use debug: clients might maliciously spam this + MinecraftServer.LOGGER.debug("Blocking frozen player " + this.toString() + " from spectating entity " + entity.toString()); + return; + } + } + + this.camera = entity; // only set after validating state + + if (entity != this) { + // Make sure we're in the right place + this.ejectPassengers(); // teleport can fail if we have passengers... + this.getBukkitEntity().teleport(new Location(entity.getCommandSenderWorld().getWorld(), entity.getX(), entity.getY(), entity.getZ(), this.yRot, this.xRot), TeleportCause.SPECTATE); // Correctly handle cross-world entities from api calls by using CB teleport + + // Make sure we're tracking the entity before sending + ChunkMap.TrackedEntity tracker = ((ServerLevel)entity.level).getChunkSource().chunkMap.entityMap.get(entity.getId()); + if (tracker != null) { // dumb plugins... + tracker.updatePlayer(this); + } + } else { + this.connection.teleport(this.camera.getX(), this.camera.getY(), this.camera.getZ(), this.yRot, this.xRot, TeleportCause.SPECTATE); // CraftBukkit + } + this.connection.send(new ClientboundSetCameraPacket(entity)); + // Paper end } @Override diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java index 900c9b1106a153bc386f6c3d9c11226f8ac69f86..4fd8d775790c037e82f9b0d29ed0eccf03c2dc66 100644 --- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java +++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java @@ -1353,6 +1353,7 @@ public class ServerGamePacketListenerImpl implements ServerGamePacketListener { } // CraftBukkit start - Delegate to teleport(Location) + public final void teleport(double d0, double d1, double d2, float f, float f1, PlayerTeleportEvent.TeleportCause cause) { this.a(d0, d1, d2, f, f1, cause); } // Paper - OBFHELPER public void a(double d0, double d1, double d2, float f, float f1, PlayerTeleportEvent.TeleportCause cause) { this.a(d0, d1, d2, f, f1, Collections.emptySet(), cause); }