mirror of
https://we.phorge.it/source/phorge.git
synced 2024-11-09 16:32:39 +01:00
123831b53f
Summary: The question mark in `@param type? $foo Desc` is a custom notation not consistently applied across the codebase and not necessarily obvious to the reader (because custom and not mentioned in https://github.com/php-fig/fig-standards/blob/master/proposed/phpdoc.md ). Instead, explicitly state "optional" in the parameter description for clarity. Closes T15925. Test Plan: Run PHPStan, see no `PHPDoc @param has invalid value (type? [...]` style output anymore. Reviewers: O1 Blessed Committers, valerio.bozzolan Reviewed By: O1 Blessed Committers, valerio.bozzolan Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno Maniphest Tasks: T15925 Differential Revision: https://we.phorge.it/D25797
77 lines
2.6 KiB
PHP
77 lines
2.6 KiB
PHP
<?php
|
|
|
|
/**
|
|
* Parse the "X_FORWARDED_FOR" HTTP header to determine the original client
|
|
* address.
|
|
*
|
|
* @param int $layers (optional) Number of devices to trust.
|
|
* @return void
|
|
*/
|
|
function preamble_trust_x_forwarded_for_header($layers = 1) {
|
|
if (!is_int($layers) || ($layers < 1)) {
|
|
echo
|
|
'preamble_trust_x_forwarded_for_header(<layers>): '.
|
|
'"layers" parameter must an integer larger than 0.'."\n";
|
|
echo "\n";
|
|
exit(1);
|
|
}
|
|
|
|
if (!isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
|
|
return;
|
|
}
|
|
|
|
$forwarded_for = $_SERVER['HTTP_X_FORWARDED_FOR'];
|
|
if (!strlen($forwarded_for)) {
|
|
return;
|
|
}
|
|
|
|
$address = preamble_get_x_forwarded_for_address($forwarded_for, $layers);
|
|
|
|
$_SERVER['REMOTE_ADDR'] = $address;
|
|
}
|
|
|
|
function preamble_get_x_forwarded_for_address($raw_header, $layers) {
|
|
// The raw header may be a list of IPs, like "1.2.3.4, 4.5.6.7", if the
|
|
// request the load balancer received also had this header. In particular,
|
|
// this happens routinely with requests received through a CDN, but can also
|
|
// happen illegitimately if the client just makes up an "X-Forwarded-For"
|
|
// header full of lies.
|
|
|
|
// We can only trust the N elements at the end of the list which correspond
|
|
// to network-adjacent devices we control. Usually, we're behind a single
|
|
// load balancer and "N" is 1, so we want to take the last element in the
|
|
// list.
|
|
|
|
// In some cases, "N" may be more than 1, if the network is configured so
|
|
// that that requests are routed through multiple layers of load balancers
|
|
// and proxies. In this case, we want to take the Nth-to-last element of
|
|
// the list.
|
|
|
|
$addresses = explode(',', $raw_header);
|
|
|
|
// If we have more than one trustworthy device on the network path, discard
|
|
// corresponding elements from the list. For example, if we have 7 devices,
|
|
// we want to discard the last 6 elements of the list.
|
|
|
|
// The final device address does not appear in the list, since devices do
|
|
// not append their own addresses to "X-Forwarded-For".
|
|
|
|
$discard_addresses = ($layers - 1);
|
|
|
|
// However, we don't want to throw away all of the addresses. Some requests
|
|
// may originate from within the network, and may thus not have as many
|
|
// addresses as we expect. If we have fewer addresses than trustworthy
|
|
// devices, discard all but one address.
|
|
|
|
$max_discard = (count($addresses) - 1);
|
|
|
|
$discard_count = min($discard_addresses, $max_discard);
|
|
if ($discard_count) {
|
|
$addresses = array_slice($addresses, 0, -$discard_count);
|
|
}
|
|
|
|
$original_address = end($addresses);
|
|
$original_address = trim($original_address);
|
|
|
|
return $original_address;
|
|
}
|