IP address resolving class HostnameResolver { // Resolve hostname -> IP address function resolveHostname ($hostname) { // If sql_patches is not at least 0.7.0, abort here and return the hostname (gethostbyname() may return something unwanted) if (!isExtensionInstalledAndNewer('sql_patches', '0.7.0')) { // Abort here return $hostname; } // END - if // Prepare hostname, look for the ':port' part $hostArray = explode(':', $hostname, 2); $hostname = strtolower($hostArray[0]); // Is the hostname an IP address? if (preg_match('/(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])/', $hostname, $matches)) { // Then we don't need to look it up //* DEBUG: */ logDebugMessage(__METHOD__, __LINE__, sprintf("Hostname %s is an IP address. No need to lookup.", $hostname)); return $hostname; } // END - if // Log entry //* DEBUG: */ logDebugMessage(__METHOD__, __LINE__, sprintf("Begin lookup: %s", $hostname)); $ret = '0.0.0.0'; // Search for hostname in cache $result = SQL_QUERY_ESC("SELECT `ip` FROM `{?_MYSQL_PREFIX?}_dns_cache` WHERE `hostname`='%s' LIMIT 1", array($hostname), __METHOD__, __LINE__); // Does an entry exist? if (SQL_NUMROWS($result) == 1) { // Then load the hostname list($ip) = SQL_FETCHROW($result); // Count cache hit incrementStatsEntry('dns_cache_hits'); // Set fetched IP number as return value $ret = $ip; //* DEBUG: */ logDebugMessage(__METHOD__, __LINE__, sprintf("Cache used: %s->%s", $hostname, $ip)); } else { // Get IP address $ip = gethostbyname($hostname); // Count lookup hit incrementStatsEntry('dns_lookup_hits'); // Is it an IP address? if (($ip != $hostname) && (preg_match('/(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])/', $ip, $matches))) { // Seems to be an IP! Now check deeper... if (($matches[0] == $ip) && ($matches[1] >= 0) && ($matches[1] <= 255) && ($matches[2] >= 0) && ($matches[2] <= 255) && ($matches[3] >= 0) && ($matches[3] <= 255) && ($matches[4] > 0) && ($matches[4] < 255)) { // We also cache IP addresses SQL_QUERY_ESC("INSERT INTO `{?_MYSQL_PREFIX?}_dns_cache` (`ip`, `hostname`, `added`) VALUES('%s', '%s', NOW())", array($ip, $hostname), __METHOD__, __LINE__); // Set return value to $ip //* DEBUG: */ logDebugMessage(__METHOD__, __LINE__, sprintf("IP detected, cache entry written: %s->%s", $hostname, $ip)); } else { // Network address or broadcast address found //* DEBUG: */ logDebugMessage(__METHOD__, __LINE__, sprintf("IP %s is possibly a network or broadcast address.", $ip)); } } elseif ($ip == $hostname) { // Nothing found, maybe invalid! //* DEBUG: */ logDebugMessage(__METHOD__, __LINE__, sprintf("Cannot lookup: %s", $hostname)); } else { // Put entry in DB SQL_QUERY_ESC("INSERT INTO `{?_MYSQL_PREFIX?}_dns_cache` (`ip`, `hostname`, `added`) VALUES('%s', '%s', NOW())", array($ip, $hostname), __METHOD__, __LINE__); // Set return value to $ip $ret = $ip; //* DEBUG: */ logDebugMessage(__METHOD__, __LINE__, sprintf("Lookup successfull, cache entry written: %s->%s", $hostname, $ip)); } } // Free result SQL_FREERESULT($result); // Return IP number (let's hope it! return $ret; } // Purge old entries function purgeEntries() { // SQL for cleaning up SQL_QUERY('DELETE LOW_PRIORITY FROM `{?_MYSQL_PREFIX?}_dns_cache` WHERE UNIX_TIMESTAMP(`added`) < (UNIX_TIMESTAMP() - {?dns_cache_timeout?})', __METHOD__, __LINE__); } } // [EOF] ?>