wp_validate_redirect( string $location, string $default = '' )
Validates a URL for use in a redirect.
Description
Checks whether the $location is using an allowed host, if it has an absolute path. A plugin can therefore set or remove allowed host(s) to or from the list.
If the host is not allowed, then the redirect is to $default supplied
Parameters
- $location
-
(Required) The redirect to validate
- $default
-
(Optional) The value to return if $location is not allowed
Default value: ''
Return
(string) redirect-sanitized URL
Source
File: wp-includes/pluggable.php
function wp_validate_redirect($location, $default = '') {
$location = wp_sanitize_redirect( trim( $location, " \t\n\r\0\x08\x0B" ) );
// browsers will assume 'http' is your protocol, and will obey a redirect to a URL starting with '//'
if ( substr($location, 0, 2) == '//' )
$location = 'http:' . $location;
// In php 5 parse_url may fail if the URL query part contains http://, bug https://core.trac.wordpress.org/ticket/38143
$test = ( $cut = strpos($location, '?') ) ? substr( $location, 0, $cut ) : $location;
// @-operator is used to prevent possible warnings in PHP < 5.3.3.
$lp = @parse_url($test);
// Give up if malformed URL
if ( false === $lp )
return $default;
// Allow only http and https schemes. No data:, etc.
if ( isset($lp['scheme']) && !('http' == $lp['scheme'] || 'https' == $lp['scheme']) )
return $default;
if ( ! isset( $lp['host'] ) && ! empty( $lp['path'] ) && '/' !== $lp['path'][0] ) {
$path = '';
if ( ! empty( $_SERVER['REQUEST_URI'] ) ) {
$path = dirname( parse_url( 'http://placeholder' . $_SERVER['REQUEST_URI'], PHP_URL_PATH ) . '?' );
}
$location = '/' . ltrim( $path . '/', '/' ) . $location;
}
// Reject if certain components are set but host is not. This catches urls like https:host.com for which parse_url does not set the host field.
if ( ! isset( $lp['host'] ) && ( isset( $lp['scheme'] ) || isset( $lp['user'] ) || isset( $lp['pass'] ) || isset( $lp['port'] ) ) ) {
return $default;
}
// Reject malformed components parse_url() can return on odd inputs.
foreach ( array( 'user', 'pass', 'host' ) as $component ) {
if ( isset( $lp[ $component ] ) && strpbrk( $lp[ $component ], ':/?#@' ) ) {
return $default;
}
}
$wpp = parse_url(home_url());
/**
* Filters the whitelist of hosts to redirect to.
*
* @since WP-2.3.0
*
* @param array $hosts An array of allowed hosts.
* @param bool|string $host The parsed host; empty if not isset.
*/
$allowed_hosts = (array) apply_filters( 'allowed_redirect_hosts', array($wpp['host']), isset($lp['host']) ? $lp['host'] : '' );
if ( isset($lp['host']) && ( !in_array($lp['host'], $allowed_hosts) && $lp['host'] != strtolower($wpp['host'])) )
$location = $default;
return $location;
}
Changelog
Version | Description |
---|---|
WP-2.8.1 | Introduced. |