phroxyp/proxy.php

<?php

// PROXY
// Config
$serv = 'google.com'; // TODO External file
$port = 80;
$root = '';
$localRoot = '';

// Functions
function str_replace_once($search, $replace, $subject) { // TODO Credit
    $pos = strpos($subject, $search);
    if ($pos === false) {
        return $subject;
    }

    return substr($subject, 0, $pos) . $replace . substr($subject, $pos + strlen($search));
}

if (!function_exists('getallheaders')) { // TODO Credit
    function getallheaders() {
        if (!is_array($_SERVER)) {
            return array();
        }

        $headers = array();
        foreach ($_SERVER as $name => $value) {
            if (substr($name, 0, 5) == 'HTTP_') {
                $headers[str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5)))))] = $value;
            }
        }
        return $headers;
    }
}

// Target determination
$metd = $_SERVER['REQUEST_METHOD'];
$reqp = $_SERVER['REQUEST_URI'];
$reqp = str_replace_once($localRoot, '', $reqp); // TODO Reliable method

// Preparing request headers
$reqHeds = "$metd $root$reqp HTTP/1.1\r\n";
$reqHeds .= "Host: $serv:$port\r\n";

// Converting client request headers to server request headers
$reqsHedsC = getallheaders();
foreach ($reqsHedsC as $name => $content) {
    if ($name != 'Host' && $name != 'Connection') { // TODO More analysis
        $reqHeds .= "$name: $content\r\n";
    }
}

if ($metd == 'POST') { // TODO Other with data methods
    if (isset($_POST['payload'])) {
        $postData = stripslashes($_POST['payload']);
        $reqHeds .= "Content-Length: ".strlen($postData)."\r\n";
        $reqHeds .= "Connection: Close\r\n";
        $reqHeds .= "\r\n" . $postData;
    } else {
        $postinfo = '';
        foreach ($_POST as $key => $value) {
            $postinfo .= $key . '=' . urlencode($value) . '&';
        }
        $postinfo = rtrim($postinfo, '&');
        $reqHeds .= "\r\n" . $postinfo;
    }
} else {
    $reqHeds .= "Connection: Close\r\n\r\n";
}


$fp = fsockopen($serv, $port, $errno, $errstr, 30);
if (!$fp) { // TODO ErrorCode, ErrorDocument
    echo "Couldn't connect to server\n<br/>$errstr ($errno)<br />\n";
} else {
    // Sending request
    fwrite($fp, $reqHeds);
    $resBuf = '';
    while ($get = fgets($fp, 128)) {
        // Getting response
        if ($resBuf === True) { // If headers sent
            echo $get;
        } else {
            $resBuf .= $get;
            if ($sepPos = strrpos($resBuf, "\r\n\r\n")) { // Headers have been retrieved
                $resHeds = explode("\r\n", substr($resBuf, 0, $sepPos));
                foreach ($resHeds as $resHed) { // Setting headers
                    header($resHed);
                    if (substr($resHed, 0, 4) == 'HTTP') { // FastCGI fix when using ErrorDocument
                        header('Status: ' . substr($resHed, 9));
                    }
                }
                echo substr($resBuf, $sepPos + 4); // Sending the rest (usually empty)
                $resBuf = True; // Setting mode to automatically redirect
            }
        }
    }
    fclose($fp);
}
?>