WordPress Version: 6.1
/**
* Returns an anonymized IPv4 or IPv6 address.
*
* @since 4.9.6 Abstracted from `WP_Community_Events::get_unsafe_client_ip()`.
*
* @param string $ip_addr The IPv4 or IPv6 address to be anonymized.
* @param bool $ipv6_fallback Optional. Whether to return the original IPv6 address if the needed functions
* to anonymize it are not present. Default false, return `::` (unspecified address).
* @return string The anonymized IP address.
*/
function wp_privacy_anonymize_ip($ip_addr, $ipv6_fallback = false)
{
if (empty($ip_addr)) {
return '0.0.0.0';
}
// Detect what kind of IP address this is.
$ip_prefix = '';
$is_ipv6 = substr_count($ip_addr, ':') > 1;
$is_ipv4 = 3 === substr_count($ip_addr, '.');
if ($is_ipv6 && $is_ipv4) {
// IPv6 compatibility mode, temporarily strip the IPv6 part, and treat it like IPv4.
$ip_prefix = '::ffff:';
$ip_addr = preg_replace('/^\[?[0-9a-f:]*:/i', '', $ip_addr);
$ip_addr = str_replace(']', '', $ip_addr);
$is_ipv6 = false;
}
if ($is_ipv6) {
// IPv6 addresses will always be enclosed in [] if there's a port.
$left_bracket = strpos($ip_addr, '[');
$right_bracket = strpos($ip_addr, ']');
$percent = strpos($ip_addr, '%');
$netmask = 'ffff:ffff:ffff:ffff:0000:0000:0000:0000';
// Strip the port (and [] from IPv6 addresses), if they exist.
if (false !== $left_bracket && false !== $right_bracket) {
$ip_addr = substr($ip_addr, $left_bracket + 1, $right_bracket - $left_bracket - 1);
} elseif (false !== $left_bracket || false !== $right_bracket) {
// The IP has one bracket, but not both, so it's malformed.
return '::';
}
// Strip the reachability scope.
if (false !== $percent) {
$ip_addr = substr($ip_addr, 0, $percent);
}
// No invalid characters should be left.
if (preg_match('/[^0-9a-f:]/i', $ip_addr)) {
return '::';
}
// Partially anonymize the IP by reducing it to the corresponding network ID.
if (function_exists('inet_pton') && function_exists('inet_ntop')) {
$ip_addr = inet_ntop(inet_pton($ip_addr) & inet_pton($netmask));
if (false === $ip_addr) {
return '::';
}
} elseif (!$ipv6_fallback) {
return '::';
}
} elseif ($is_ipv4) {
// Strip any port and partially anonymize the IP.
$last_octet_position = strrpos($ip_addr, '.');
$ip_addr = substr($ip_addr, 0, $last_octet_position) . '.0';
} else {
return '0.0.0.0';
}
// Restore the IPv6 prefix to compatibility mode addresses.
return $ip_prefix . $ip_addr;
}