Obtener ip y otras yerbas desde php

<?php

/*
 * Clase diseñada originalmente para Basec0de.org
 * ----------------------------------------------
 * El objetivo de esta clase es recopilar todo tipo de información sobre un agente o usuario/visitante
 * de nuestro sitio web.
 * @ Author: <Harkonnen>
 * @ Status: Prototype
 * @ Contact: <[email protected]>
 * @ Last-Edit: 28/11/13
 * -----------------------------------------------
 * Tiene como dependencia el Trait Property
 */

interface iAgent
{
	public function denegar();
	public function internal_error();
}

class Agent implements iAgent
{
	use Property;
	
	private $ip = 0;
	private $session_id = 0;
	private $sistema = null;
	private $browser = null;
	private $location = null;
	
	public function __construct()
	{
		$browser = get_browser(null, true);
		$this->sistema = $browser['platform'];
		$this->browser = $browser['browser'];
		$this->session_id = isset($_SESSION) ? session_id() : null;
		$this->ip = $_SERVER['REMOTE_ADDR'];
		$this->location = $_SERVER['REQUEST_URI'];
	}
	
	public function denegar()
	{
		ob_start();
		header('HTTP/1.0 403 Forbidden');
		die();
	}
	
	public function internal_error()
	{
		ob_start();
		header('HTTP/1.0 503 Service Temporarily Unavailable');
		die();
	}
	
	public function set_ip($value) { ; }
	public function get_ip() { return $this->ip; }
	
	public function set_session_id($value) { ; }
	public function get_session_id() { return $this->session_id; }
			
	public function set_sistema($value) { ; }
	public function get_sistema() { return $this->sistema; }
	
	public function set_browser($value) { ; }
	public function get_browser() { return $this->browser; }
	
	public function set_location($value) { ; }
	public function get_location() { return $this->location; }
	
}

$agente = new Agent();
echo $agente->ip;
echo $agente->session_id;
echo htmlentities($agente->browser);

$agente = new Agent();
$agente->denegar();