inet_pton - PHP code example

The PHP Function Inet_Pon

The php function inet_pton converts an Internet network address from its text presentation form into its numeric binary form. The function takes as its argument a string representation of the IP address, and returns a buffer in network byte order that contains the numeric binary value of the address.

This function is used to create a human readable format for an IP address in a web application. The inet_pton() function is a very handy tool to have when developing websites that need to support both IPv4 and IPv6 addresses.

As you can see, this is a very simple function that converts an IP address from its string representation to its binary value. However, you should be aware that this function does not recognize netmask notation (e.g: “1.2.3.4/24” or “1:2::3:4/64”), and as such is not useful for database systems that require a specific datatype to store IPv6 addresses (e.g: MySQL or MariaDB).

The inet_pton() function is available on all platforms that have a functioning version of PHP. The function returns a 1 if the output is valid, and FALSE if an error occurred. When AF_INET is specified, the pAddrBuf parameter must point to a buffer large enough to hold an IN_ADDR structure. When AF_INET6 is specified, the pszAddrString parameter must point to a string representing an IPv6 address in dotted-octet notation (separated by colons). If either of these is not true, the function will return an extended error code as returned by WSAGetLastError.

inet_pton example

    public static function checkIp6(string $requestIp, string $ip): bool
    {
        $cacheKey = $requestIp.'-'.$ip.'-v6';
        if (null !== $cacheValue = self::getCacheResult($cacheKey)) {
            return $cacheValue;
        }

        if (!((\extension_loaded('sockets') && \defined('AF_INET6')) || @inet_pton('::1'))) {
            throw new \RuntimeException('Unable to check Ipv6. Check that PHP was not compiled with option "disable-ipv6".');
        }

        // Check to see if we were given a IP4 $requestIp or $ip by mistake         if (!filter_var($requestIp, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV6)) {
            return self::setCacheResult($cacheKey, false);
        }

        if (str_contains($ip, '/')) {
            [$address, $netmask] = explode('/', $ip, 2);

        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 {

$ipv6 = filter_var(
            $ip,
            \FILTER_VALIDATE_IP,
            \FILTER_FLAG_NO_PRIV_RANGE | \FILTER_FLAG_NO_RES_RANGE | \FILTER_FLAG_IPV6
        );

        if (!$ipv6) {
            return false;
        }

        // Convert IPv6 to packed format and back so we can check if there is a IPv4 representation of the IP         $packedIp = inet_pton($ipv6);
        if (!$packedIp) {
            return false;
        }

        $convertedIp = inet_ntop($packedIp);
        if (!$convertedIp) {
            return false;
        }
        $convertedIp = explode(':', $convertedIp);
        $ipv4 = array_pop($convertedIp);