function rDNS($ip_addr)
{
global $config;
if ($config['cache']['enabled'] && ($host = cache::get('rdns_' . $ip_addr))) {
return $host;
}
if (!$config['dns_system']) {
$host = gethostbyaddr($ip_addr);
} else {
$resp = shell_exec_error('host -W 1 ' . $ip_addr);
if (preg_match('/domain name pointer ([^\\s]+)$/', $resp, $m)) {
$host = $m[1];
} else {
$host = $ip_addr;
}
}
$isip = filter_var($host, FILTER_VALIDATE_IP);
if ($config['fcrdns'] && !$isip && DNS($host) != $ip_addr) {
$host = $ip_addr;
}
if ($config['cache']['enabled']) {
cache::set('rdns_' . $ip_addr, $host);
}
return $host;
}
function checkDNSBL()
{
global $config;
if (isIPv6()) {
return;
}
// No IPv6 support yet.
if (!isset($_SERVER['REMOTE_ADDR'])) {
return;
}
// Fix your web server configuration
if (in_array($_SERVER['REMOTE_ADDR'], $config['dnsbl_exceptions'])) {
return;
}
$ipaddr = ReverseIPOctets($_SERVER['REMOTE_ADDR']);
foreach ($config['dnsbl'] as $blacklist) {
if (!is_array($blacklist)) {
$blacklist = array($blacklist);
}
if (($lookup = str_replace('%', $ipaddr, $blacklist[0])) == $blacklist[0]) {
$lookup = $ipaddr . '.' . $blacklist[0];
}
if (!($ip = DNS($lookup))) {
continue;
}
// not in list
$blacklist_name = isset($blacklist[2]) ? $blacklist[2] : $blacklist[0];
if (!isset($blacklist[1])) {
// If you're listed at all, you're blocked.
error(sprintf($config['error']['dnsbl'], $blacklist_name));
} elseif (is_array($blacklist[1])) {
foreach ($blacklist[1] as $octet) {
if ($ip == $octet || $ip == '127.0.0.' . $octet) {
error(sprintf($config['error']['dnsbl'], $blacklist_name));
}
}
} elseif (is_callable($blacklist[1])) {
if ($blacklist[1]($ip)) {
error(sprintf($config['error']['dnsbl'], $blacklist_name));
}
} else {
if ($ip == $blacklist[1] || $ip == '127.0.0.' . $blacklist[1]) {
error(sprintf($config['error']['dnsbl'], $blacklist_name));
}
}
}
}
