/**
* Determin if an IP address is valid or not
*
* @date 2005-04-02
* @param string $ip IP address to test
* @return bool true = valid, false= not valid
*/
function is_ip_address($ip) {
if(is_string($ip) && ereg('^([0-9]{1,3})\.([0-9]{1,3})\.' .
'([0-9]{1,3})\.([0-9]{1,3})$',
$ip, $part)) {
if($part[1] <= 255 && $part[2] <= 255 &&
$part[3] <= 255 && $part[4] <= 255)
return true;
}
return false;
}

/**
* Determin if an IP address is valid on INTERNET or not
*
* @date 2005-04-02
* @param string $ip IP address to test
* @return bool true = valid, false= not valid
*/
function valid_internet_ip($ip) {
if(!empty($ip) && ip2long($ip)!=-1)
{
$reserved_ip = array (
array('0.0.0.0','2.255.255.255'),
array('10.0.0.0','10.255.255.255'),
array('127.0.0.0','127.255.255.255'),
array('169.254.0.0','169.254.255.255'),
array('172.16.0.0','172.31.255.255'),
array('192.0.2.0','192.0.2.255'),
array('192.168.0.0','192.168.255.255'),
array('255.255.255.0','255.255.255.255')
);

foreach ($reserved_ip as $r)
{
$min = ip2long($r[0]);
$max = ip2long($r[1]);
if((ip2long($ip) >= $min) && (ip2long($ip) <= $max)) return false;
}
return true;
}
else return false;
}

/**
* Determin if an IP address is banned in the database
*
* @date 2005-04-02
* @param string $ip IP address to test
* @return bool true = banned, false= not banned
*/
function is_ip_banned($ip) {
$longip = ip2long($ip);
if($longip != -1) {
$result = mysql_query("SELECT * FROM failedauth WHERE (".$longip." BETWEEN First_IP AND Last_IP) AND banned");
return mysql_num_rows($result) != 0;
} else {
return true;
}
}
/**
* Find the IP address of the user
*
* @date 2005-04-02
* @return string IP address
*/
function get_ip() {
if(valid_internet_ip($_SERVER['HTTP_CLIENT_IP'])) {
return $_SERVER['HTTP_CLIENT_IP'];
} elseif($_SERVER['HTTP_X_FORWARDED_FOR']!="") {
$forwarded=str_replace(",","",$_SERVER['HTTP_X_FORWARDED_FOR']);
$forwarded_array=split(" ",$forwarded);
foreach($forwarded_array as $value) {
if(valid_internet_ip($value)) {
return $value;
}
}
}
return $_SERVER['REMOTE_ADDR'];
}

/**
* Determin if a string is a FQDN
*
* @date 2005-04-02
* @param string $host Host to test
* bool $force_dot Force do in the address
* @return bool true = valid, false= not valid
*/
function check_fqdn($host, $force_dot=false) {
if(!ereg("^\[?[0-9\.]+\]?$", $host)) { // Check if domain is IP
$fqdn = explode(".", $host);
if(count($fqdn) < 2) {
return false;
}
for ($i = 0; $i < count($domain_array); $i++) {
if(!ereg("^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|([A-Za-z0-9]+))$", $fqdn[$i])) {
return false;
}
}
return true;
}
return false;
}

/**
* Find the hostname of the user from his IP address
*
* @date 2005-04-02
* @param string $ip The IP address to lookup
* @return string Hostname of the user or IP if failed to get it
*/
function get_host($ip) {
if(preg_match("|win|i",PHP_OS)) {
$runext = exec("nslookup -timeout=2 -retry=1 $ip", $output, $error); // Now works on windows
if(!$error){
$resolved = split(":",$output[3]);
if(check_fqdn($resolved[1])) {
return trim($resolved[1]);
}
}
} else {
$output = `host -W 2 $ip`;
if(ereg(".*pointer ([A-Za-z0-9.-]+)\..*",$output,$regs)) {
return $regs[1];
}
}
return $ip;
}