Miscellany

function check_flood() {        $ip = ip2long($addr = $_SERVER['HTTP_X_FORWARDED_FOR']);        if (!$ip or ($ip == -1) or (($ip >> 24) == 10) or (($ip >> 20) == -0x53f) or (($ip >> 16) == -0x3f58))                $ip = ip2long($addr = $_SERVER['REMOTE_ADDR']);        #debug("Checking for flood. addr=$addr ip=$ip");        mysql_query("delete from blocked where last<now() - interval count+3600 second");        mysql_query("delete from requests where time<now() - interval 5 minute");        mysql_query(mkquery("update blocked set count=count+1 where ip=%d", $ip));        $cnt = mysql_affected_rows();        if ($cnt > 0) {                header("HTTP/1.0 403 Flood detected.");                exit;        }        mysql_query(mkquery("insert into requests (ip) values(%d)", $ip));        $rqcnt = mysql_fetch_row(mysql_query(mkquery('select count(*),count(if(time>now()-interval 1 minute,1,NULL)),min(time) from requests where ip=%d', $ip)));        #debug("$addr = $ip had $rqcnt[0]/$rqcnt[1] requests in the last 60 seconds/since $rqcnt[2], blocked cnt $cnt.");        if ($rqcnt[0] > 60 || $rqcnt[1] > 25) {                dolog("Flood detected ($rqcnt[0] from $addr), blocking.");                mysql_query(mkquery('insert into blocked (first,ip,count) values("%s",%d,%d)', $rqcnt[2],$ip,$rqcnt[0]));                header("HTTP/1.0 403 Flood detected.");                exit;        }}