note 104253 deleted from function.ip2long by danbrown

Note Submitter: php dot 1 dot haemmluk at spamgourmet dot com ---- Using the ip2bin code from above, I created two functions that can be used to check whether a given IPv4 or IPv6 IP matches an IPv4 or IPv6 netmask: <?php // Returns true if IP is in IPv4/IPv6 CIDR range // and returns false otherwise function isIPinCIDRBlock($cidr, $ip) { // Split CIDR notation list ($net, $mask) = split ("/", $cidr); // Convert to binary string value of 1s and 0s $netAsBinary = ip2bin($net); $ipAsBinary = ip2bin($ip); // Return false if netmask and ip are using different protocols if (strlen($netAsBinary) != strlen($ipAsBinary)){ return false; } // Compare the first $mask bits for($i = 0; $i < $mask; $i++){ // Return false if bits don't match if ($netAsBinary[$i] != $ipAsBinary[$i]){ return false; } } // If we got here, ip matches net return true; } // Converts IP in human readable format to binary string function ip2bin($ip){ // Handle IPv4 IP if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false){ return base_convert(ip2long($ip),10,2); } // Return false if IP is neither IPv4 nor a IPv6 IP if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) === false){ return false; } // Convert IP to binary structure and return false if this fails if(($ipAsBinStructure = inet_pton($ip)) === false) { return false; } $numOfBytes = 16; $ipAsBinaryString = ''; // Convert IP to binary string while ($numOfBytes > 0){ // Convert current byte to decimal number $currentByte = ord($ipAsBinStructure[$numOfBytes - 1]); // Convert currenty byte to string of 1 and 0 $currentByteAsBinary = sprintf("%08b", $currentByte); // Prepend to rest of IP in binary string $ipAsBinaryString = $currentByteAsBinary.$ipAsBinaryString; // Decrease byte counter $numOfBytes--; } return $ipAsBinaryString; } ?>