function requestBlocker()
{
/*
Version 1.0 11 Jan 2013
Author: Szczepan K
http://www.szczepan.info
me[@] szczepan [dot] info
###Description###
A PHP function which can Block unwanted Requests to reduce your Website-Traffic.
God for Spiders, Bots and annoying Clients.
*/
$dir = 'requestBlocker/'; ## Create & set directory writeable!!!!
$rules = array(
#You can add multiple Rules in a array like this one here
#Notice that large "sec definitions" (like 60*60*60) will **** up your client File
array(
//if >5 requests in 5 Seconds then Block client 15 Seconds
'requests' => 5, //5 requests
'sek' => 5, //5 requests in 5 Seconds
'blockTime' => 15 // Block client 15 Seconds
),
array(
//if >10 requests in 30 Seconds then Block client 20 Seconds
'requests' => 10, //10 requests
'sek' => 30, //10 requests in 30 Seconds
'blockTime' => 20 // Block client 20 Seconds
),
array(
//if >200 requests in 1 Hour then Block client 10 Minutes
'requests' => 200, //200 requests
'sek' => 60 * 60, //200 requests in 1 Hour
'blockTime' => 60 * 10 // Block client 10 Minutes
)
);
$time = time();
$blockIt = array();
$user = array();
#Set Unique Name for each Client-File
$user[] = isset($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : 'IP_unknown';
$user[] = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';
$user[] = strtolower(gethostbyaddr($user[0]));
# Notice that i use files because bots does not accept Sessions
$botFile = $dir . substr($user[0], 0, 8) . '_' . substr(md5(join('', $user)), 0, 5) . '.txt';
if (file_exists($botFile)) {
$file = file_get_contents($botFile);
$client = unserialize($file);
} else {
$client = array();
$client['time'][$time] = 0;
}
# Set/Unset Blocktime for blocked Clients
if (isset($client['block'])) {
foreach ($client['block'] as $ruleNr => $timestampPast) {
$left = $time - $timestampPast;
if (($left) > $rules[$ruleNr]['blockTime']) {
unset($client['block'][$ruleNr]);
continue;
}
$blockIt[] = 'Block active for Rule: ' . $ruleNr . ' - unlock in ' . ($left - $rules[$ruleNr]['blockTime']) . ' Sec.';
}
if (!empty($blockIt)) {
return $blockIt;
}
}
# log/count each access
if (!isset($client['time'][$time])) {
$client['time'][$time] = 1;
} else {
$client['time'][$time]++;
}
#check the Rules for Client
$min = array(
0
);
foreach ($rules as $ruleNr => $v) {
$i = 0;
$tr = false;
$sum[$ruleNr] = '';
$requests = $v['requests'];
$sek = $v['sek'];
foreach ($client['time'] as $timestampPast => $count) {
if (($time - $timestampPast) < $sek) {
$sum[$ruleNr] += $count;
if ($tr == false) {
#register non-use Timestamps for File
$min[] = $i;
unset($min[0]);
$tr = true;
}
}
$i++;
}
if ($sum[$ruleNr] > $requests) {
$blockIt[] = 'Limit : ' . $ruleNr . '=' . $requests . ' requests in ' . $sek . ' seconds!';
$client['block'][$ruleNr] = $time;
}
}
$min = min($min) - 1;
#drop non-use Timestamps in File
foreach ($client['time'] as $k => $v) {
if (!($min <= $i)) {
unset($client['time'][$k]);
}
}
$file = file_put_contents($botFile, serialize($client));
return $blockIt;
}
if ($t = requestBlocker()) {
echo 'dont pass here!';
print_R($t);
} else {
echo "go on!";
}
