DedicatedQueryNetworkInterface.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\query;
 
use pocketmine\network\AdvancedNetworkInterface;
use pocketmine\network\Network;
use function preg_match;
use function socket_bind;
use function socket_close;
use function socket_create;
use function socket_last_error;
use function socket_recvfrom;
use function socket_select;
use function socket_sendto;
use function socket_set_nonblock;
use function socket_set_option;
use function socket_strerror;
use function strlen;
use function time;
use function trim;
use const AF_INET;
use const AF_INET6;
use const IPPROTO_IPV6;
use const IPV6_V6ONLY;
use const PHP_INT_MAX;
use const SOCK_DGRAM;
use const SOCKET_EADDRINUSE;
use const SOCKET_ECONNRESET;
use const SOCKET_EWOULDBLOCK;
use const SOL_UDP;
 
final class DedicatedQueryNetworkInterface implements AdvancedNetworkInterface{
    private \Socket $socket;
    private Network $network;
    private array $blockedIps = [];
    private array $rawPacketPatterns = [];
 
    public function __construct(
        private string $ip,
        private int $port,
        bool $ipV6,
        private \Logger $logger
    ){
        $socket = @socket_create($ipV6 ? AF_INET6 : AF_INET, SOCK_DGRAM, SOL_UDP);
        if($socket === false){
            throw new \RuntimeException("Failed to create socket");
        }
        if($ipV6){
            socket_set_option($socket, IPPROTO_IPV6, IPV6_V6ONLY, 1); //disable linux's cool but annoying ipv4-over-ipv6 network stack
        }
        $this->socket = $socket;
    }
 
    public function start() : void{
        if(!@socket_bind($this->socket, $this->ip, $this->port)){
            $error = socket_last_error($this->socket);
            if($error === SOCKET_EADDRINUSE){ //platform error messages aren't consistent
                throw new \RuntimeException("Failed to bind socket: Something else is already running on $this->ip $this->port", $error);
            }
            throw new \RuntimeException("Failed to bind to $this->ip $this->port: " . trim(socket_strerror($error)), $error);
        }
        socket_set_nonblock($this->socket);
        $this->logger->info("Running on $this->ip $this->port");
    }
 
    public function setName(string $name) : void{
        //NOOP
    }
 
    public function tick() : void{
        $r = [$this->socket];
        $w = null;
        $e = null;
        if(@socket_select($r, $w, $e, 0, 0) === 1){
            $address = "";
            $port = 0;
            $buffer = "";
            while(true){
                $bytes = @socket_recvfrom($this->socket, $buffer, 65535, 0, $address, $port);
                if($bytes !== false){
                    if(isset($this->blockedIps[$address]) && $this->blockedIps[$address] > time()){
                        $this->logger->debug("Dropped packet from banned address $address");
                        continue;
                    }
                    foreach($this->rawPacketPatterns as $pattern){
                        if(preg_match($pattern, $buffer) === 1){
                            $this->network->processRawPacket($this, $address, $port, $buffer);
                            break;
                        }
                    }
                }else{
                    $errno = socket_last_error($this->socket);
                    if($errno === SOCKET_EWOULDBLOCK){
                        break;
                    }
                    if($errno !== SOCKET_ECONNRESET){ //remote peer disappeared unexpectedly, this might spam like crazy so we don't log it
                        $this->logger->debug("Failed to recv (errno $errno): " . trim(socket_strerror($errno)));
                    }
                }
            }
        }
    }
 
    public function blockAddress(string $address, int $timeout = 300) : void{
        $this->blockedIps[$address] = $timeout > 0 ? time() + $timeout : PHP_INT_MAX;
    }
 
    public function unblockAddress(string $address) : void{
        unset($this->blockedIps[$address]);
    }
 
    public function setNetwork(Network $network) : void{
        $this->network = $network;
    }
 
    public function sendRawPacket(string $address, int $port, string $payload) : void{
        if(@socket_sendto($this->socket, $payload, strlen($payload), 0, $address, $port) === false){
            $errno = socket_last_error($this->socket);
            throw new \RuntimeException("Failed to send to $address $port (errno $errno): " . trim(socket_strerror($errno)), $errno);
        }
    }
 
    public function addRawPacketFilter(string $regex) : void{
        $this->rawPacketPatterns[] = $regex;
    }
 
    public function shutdown() : void{
        @socket_close($this->socket);
    }
}