raklib/src/protocol/PacketSerializer.php

<?php
 
/*
 * This file is part of RakLib.
 * Copyright (C) 2014-2022 PocketMine Team <https://github.com/pmmp/RakLib>
 *
 * RakLib is not affiliated with Jenkins Software LLC nor RakNet.
 *
 * RakLib is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 */
 
declare(strict_types=1);
 
namespace raklib\protocol;
 
use pocketmine\utils\BinaryDataException;
use pocketmine\utils\BinaryStream;
use raklib\utils\InternetAddress;
use function assert;
use function count;
use function explode;
use function inet_ntop;
use function inet_pton;
use function strlen;
use const AF_INET6;
 
final class PacketSerializer extends BinaryStream{
 
    public function getString() : string{
        return $this->get($this->getShort());
    }
 
    public function getAddress() : InternetAddress{
        $version = $this->getByte();
        if($version === 4){
            $addr = ((~$this->getByte()) & 0xff) . "." . ((~$this->getByte()) & 0xff) . "." . ((~$this->getByte()) & 0xff) . "." . ((~$this->getByte()) & 0xff);
            $port = $this->getShort();
            return new InternetAddress($addr, $port, $version);
        }elseif($version === 6){
            //http://man7.org/linux/man-pages/man7/ipv6.7.html
            $this->getLShort(); //Family, AF_INET6
            $port = $this->getShort();
            $this->getInt(); //flow info
            $addr = inet_ntop($this->get(16));
            if($addr === false){
                throw new BinaryDataException("Failed to parse IPv6 address");
            }
            $this->getInt(); //scope ID
            return new InternetAddress($addr, $port, $version);
        }else{
            throw new BinaryDataException("Unknown IP address version $version");
        }
    }
 
    public function putString(string $v) : void{
        $this->putShort(strlen($v));
        $this->put($v);
    }
 
    public function putAddress(InternetAddress $address) : void{
        $version = $address->getVersion();
        $this->putByte($version);
        if($version === 4){
            $parts = explode(".", $address->getIp());
            assert(count($parts) === 4, "Wrong number of parts in IPv4 IP, expected 4, got " . count($parts));
            foreach($parts as $b){
                $this->putByte((~((int) $b)) & 0xff);
            }
            $this->putShort($address->getPort());
        }elseif($version === 6){
            $this->putLShort(AF_INET6);
            $this->putShort($address->getPort());
            $this->putInt(0);
            $rawIp = inet_pton($address->getIp());
            if($rawIp === false){
                throw new \InvalidArgumentException("Invalid IPv6 address could not be encoded");
            }
            $this->put($rawIp);
            $this->putInt(0);
        }else{
            throw new \InvalidArgumentException("IP version $version is not supported");
        }
    }
}