ResourcePacksPacketHandler.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine\network\mcpe\handler;
 
use pocketmine\lang\KnownTranslationFactory;
use pocketmine\network\mcpe\NetworkSession;
use pocketmine\network\mcpe\protocol\ProtocolInfo;
use pocketmine\network\mcpe\protocol\ResourcePackChunkDataPacket;
use pocketmine\network\mcpe\protocol\ResourcePackChunkRequestPacket;
use pocketmine\network\mcpe\protocol\ResourcePackClientResponsePacket;
use pocketmine\network\mcpe\protocol\ResourcePackDataInfoPacket;
use pocketmine\network\mcpe\protocol\ResourcePacksInfoPacket;
use pocketmine\network\mcpe\protocol\ResourcePackStackPacket;
use pocketmine\network\mcpe\protocol\types\Experiments;
use pocketmine\network\mcpe\protocol\types\resourcepacks\ResourcePackInfoEntry;
use pocketmine\network\mcpe\protocol\types\resourcepacks\ResourcePackStackEntry;
use pocketmine\network\mcpe\protocol\types\resourcepacks\ResourcePackType;
use pocketmine\resourcepacks\ResourcePack;
use function array_keys;
use function array_map;
use function ceil;
use function count;
use function implode;
use function strpos;
use function strtolower;
use function substr;
 
class ResourcePacksPacketHandler extends PacketHandler{
    private const PACK_CHUNK_SIZE = 256 * 1024; //256KB
 
    private const MAX_CONCURRENT_CHUNK_REQUESTS = 1;
 
    private array $resourcePacksById = [];
 
    private array $downloadedChunks = [];
 
    private \SplQueue $requestQueue;
 
    private int $activeRequests = 0;
 
    public function __construct(
        private NetworkSession $session,
        private array $resourcePackStack,
        private array $encryptionKeys,
        private bool $mustAccept,
        private \Closure $completionCallback
    ){
        $this->requestQueue = new \SplQueue();
        foreach($resourcePackStack as $pack){
            $this->resourcePacksById[$pack->getPackId()] = $pack;
        }
    }
 
    private function getPackById(string $id) : ?ResourcePack{
        return $this->resourcePacksById[strtolower($id)] ?? null;
    }
 
    public function setUp() : void{
        $resourcePackEntries = array_map(function(ResourcePack $pack) : ResourcePackInfoEntry{
            //TODO: more stuff
 
            return new ResourcePackInfoEntry(
                $pack->getPackId(),
                $pack->getPackVersion(),
                $pack->getPackSize(),
                $this->encryptionKeys[$pack->getPackId()] ?? "",
                "",
                $pack->getPackId(),
                false
            );
        }, $this->resourcePackStack);
        //TODO: support forcing server packs
        $this->session->sendDataPacket(ResourcePacksInfoPacket::create(
            resourcePackEntries: $resourcePackEntries,
            mustAccept: $this->mustAccept,
            hasAddons: false,
            hasScripts: false
        ));
        $this->session->getLogger()->debug("Waiting for client to accept resource packs");
    }
 
    private function disconnectWithError(string $error) : void{
        $this->session->disconnectWithError(
            reason: "Error downloading resource packs: " . $error,
            disconnectScreenMessage: KnownTranslationFactory::disconnectionScreen_resourcePack()
        );
    }
 
    public function handleResourcePackClientResponse(ResourcePackClientResponsePacket $packet) : bool{
        switch($packet->status){
            case ResourcePackClientResponsePacket::STATUS_REFUSED:
                //TODO: add lang strings for this
                $this->session->disconnect("Refused resource packs", "You must accept resource packs to join this server.", true);
                break;
            case ResourcePackClientResponsePacket::STATUS_SEND_PACKS:
                foreach($packet->packIds as $uuid){
                    //dirty hack for mojang's dirty hack for versions
                    $splitPos = strpos($uuid, "_");
                    if($splitPos !== false){
                        $uuid = substr($uuid, 0, $splitPos);
                    }
                    $pack = $this->getPackById($uuid);
 
                    if(!($pack instanceof ResourcePack)){
                        //Client requested a resource pack but we don't have it available on the server
                        $this->disconnectWithError("Unknown pack $uuid requested, available packs: " . implode(", ", array_keys($this->resourcePacksById)));
                        return false;
                    }
 
                    $this->session->sendDataPacket(ResourcePackDataInfoPacket::create(
                        $pack->getPackId(),
                        self::PACK_CHUNK_SIZE,
                        (int) ceil($pack->getPackSize() / self::PACK_CHUNK_SIZE),
                        $pack->getPackSize(),
                        $pack->getSha256(),
                        false,
                        ResourcePackType::RESOURCES //TODO: this might be an addon (not behaviour pack), needed to properly support client-side custom items
                    ));
                }
                $this->session->getLogger()->debug("Player requested download of " . count($packet->packIds) . " resource packs");
 
                break;
            case ResourcePackClientResponsePacket::STATUS_HAVE_ALL_PACKS:
                $stack = array_map(static function(ResourcePack $pack) : ResourcePackStackEntry{
                    return new ResourcePackStackEntry($pack->getPackId(), $pack->getPackVersion(), ""); //TODO: subpacks
                }, $this->resourcePackStack);
 
                //we support chemistry blocks by default, the client should already have this installed
                $stack[] = new ResourcePackStackEntry("0fba4063-dba1-4281-9b89-ff9390653530", "1.0.0", "");
 
                //we don't force here, because it doesn't have user-facing effects
                //but it does have an annoying side-effect when true: it makes
                //the client remove its own non-server-supplied resource packs.
                $this->session->sendDataPacket(ResourcePackStackPacket::create($stack, [], false, ProtocolInfo::MINECRAFT_VERSION_NETWORK, new Experiments([], false), false));
                $this->session->getLogger()->debug("Applying resource pack stack");
                break;
            case ResourcePackClientResponsePacket::STATUS_COMPLETED:
                $this->session->getLogger()->debug("Resource packs sequence completed");
                ($this->completionCallback)();
                break;
            default:
                return false;
        }
 
        return true;
    }
 
    public function handleResourcePackChunkRequest(ResourcePackChunkRequestPacket $packet) : bool{
        $pack = $this->getPackById($packet->packId);
        if(!($pack instanceof ResourcePack)){
            $this->disconnectWithError("Invalid request for chunk $packet->chunkIndex of unknown pack $packet->packId, available packs: " . implode(", ", array_keys($this->resourcePacksById)));
            return false;
        }
 
        $packId = $pack->getPackId(); //use this because case may be different
 
        if(isset($this->downloadedChunks[$packId][$packet->chunkIndex])){
            $this->disconnectWithError("Duplicate request for chunk $packet->chunkIndex of pack $packet->packId");
            return false;
        }
 
        $offset = $packet->chunkIndex * self::PACK_CHUNK_SIZE;
        if($offset < 0 || $offset >= $pack->getPackSize()){
            $this->disconnectWithError("Invalid out-of-bounds request for chunk $packet->chunkIndex of $packet->packId: offset $offset, file size " . $pack->getPackSize());
            return false;
        }
 
        if(!isset($this->downloadedChunks[$packId])){
            $this->downloadedChunks[$packId] = [$packet->chunkIndex => true];
        }else{
            $this->downloadedChunks[$packId][$packet->chunkIndex] = true;
        }
 
        $this->requestQueue->enqueue([$pack, $packet->chunkIndex]);
        $this->processChunkRequestQueue();
 
        return true;
    }
 
    private function processChunkRequestQueue() : void{
        if($this->activeRequests >= self::MAX_CONCURRENT_CHUNK_REQUESTS || $this->requestQueue->isEmpty()){
            return;
        }
        [$pack, $chunkIndex] = $this->requestQueue->dequeue();
 
        $packId = $pack->getPackId();
        $offset = $chunkIndex * self::PACK_CHUNK_SIZE;
        $chunkData = $pack->getPackChunk($offset, self::PACK_CHUNK_SIZE);
        $this->activeRequests++;
        $this->session
            ->sendDataPacketWithReceipt(ResourcePackChunkDataPacket::create($packId, $chunkIndex, $offset, $chunkData))
            ->onCompletion(
                function() : void{
                    $this->activeRequests--;
                    $this->processChunkRequestQueue();
                },
                function() : void{
                    //this may have been rejected because of a disconnection - this will do nothing in that case
                    $this->disconnectWithError("Plugin interrupted sending of resource packs");
                }
            );
    }
}