Question

<?php

$host = 'www.yourtargeturl.com';
$service_uri = '/detect_referal.php';
$vars ='additional_option1=yes&additional_option2=un';

$header = "Host: $host\r\n";
$header .= "User-Agent: PHP Script\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Referer: http://www.google.com/search?hl=en&q=jigh&btnG=Google+Search \r\n";
$header .= "Content-Length: ".strlen($vars)."\r\n";
$header .= "Connection: close\r\n\r\n";

$fp = fsockopen("".$host,80, $errno, $errstr);

if (!$fp) {
  echo "$errstr ($errno)<br/>\n";
  echo $fp;
} else {
fputs($fp, "POST $service_uri  HTTP/1.1\r\n");
fputs($fp, $header.$vars);
fwrite($fp, $out);

while (!feof($fp)) {
echo fgets($fp, 128);
}
fclose($fp);
}
?>

This is changing the $_SERVER['HTTP_REFERER']. How can I change $_SERVER['REMOTE_ADDR']. What code should I append in $header?

Answer 1

You can’t do that. The IP address is determined at the beginning of the TCP connection, not in the HTTP headers. (It is possible to spoof [though not remotely like that], but then you won’t get the response back.)