PHP Socket Connection - Telnet refused to connect

Question

I wrote a small class to manage socket connections in PHP:

    #/usr/bin/php

<?php

    define('PORT', 5000);
    define('IP', '127.0.0.1');


    /**
    * SocketManager
    */
    class SocketManager {

        private $sock = null;
        public $errorcode = null;
        public $errormsg = null;
        public $client = null;

        public function initSocket($onConnect) {
            echo "Init Socket\n";
            if (!($this->sock = socket_create(AF_INET, SOCK_STREAM, 0))) {
                $this->errorcode = socket_last_error();
                $thid->errormsg = socket_strerror($errorcode);
                return;
            }
            echo "Created Socket\n";
            if (!socket_bind($this->sock, IP , PORT)) {
                $this->errorcode = socket_last_error();
                $thid->errormsg = socket_strerror($errorcode);
                return;
            }
            echo "Bind Socket\n";
            if(!socket_listen($this->sock , 10)) {
                $this->errorcode = socket_last_error();
                $thid->errormsg = socket_strerror($errorcode);
                return;
            }
            echo "Listening on " . PORT . "\n";
            while (true) {
                echo ".";
                $this->client = socket_accept($this->sock);
                if(socket_getpeername($client , $address , $port)) {
                    if (!is_null($onConnect)) {
                        call_user_func_array($onConnect,array($client,$address,$port));
                    }
                }
            }
        }

        function __construct($onConnect) {
            $this->initSocket($onConnect);
        }
    }

    function handleConnection($client,$address,$port) {
        echo "User Connected: $address\n";
    }

    $socket = new SocketManager("handleConnection");
?>

Starting this will cause the following output:

#/usr/bin/php

Init Socket
Created Socket
Bind Socket
Listening on 5000
.

Checking using netstat prints out the following:

netstat -nap | grep LISTEN

tcp        0      0 127.0.0.1:5000          0.0.0.0:*               LISTEN      32301/php

And also nmap tells me the port 5000 is opened:

nmap -p 5000 localhost

PORT     STATE SERVICE
5000/tcp open  upnp

However still if I try to connect using telnet:

telnet SERVER_IP 5000 I get:

Trying SERVER_IP...
telnet: connect to address SERVER_IP: Connection refused
telnet: Unable to connect to remote host

I also tried altering iptables to accept on the port, but it did not work, but it is possible that I just did it wrong.

Any other idea that I could try out?

• xCoder

Answer 1

You have to change:

define('IP', '127.0.0.1');

with:

define('IP', '0.0.0.0');

By using 127.0.0.1 you will be able to connect only from the server itself, since it binds to 127.0.0.1, just as netstat shows.