A simple and very fast function to check against CIDR.
Your previous examples are too complicated and involves a lot of functions call.
Here it is (only with arithmetic operators and call only to ip2long () and split() ):
<?php
function ipCIDRCheck ($IP, $CIDR) {
list ($net, $mask) = split ("/", $CIDR);
$ip_net = ip2long ($net);
$ip_mask = ~((1 << (32 - $mask)) - 1);
$ip_ip = ip2long ($IP);
$ip_ip_net = $ip_ip & $ip_mask;
return ($ip_ip_net == $ip_net);
}
?>
call example: <?php echo ipCheck ("192.168.1.23", "192.168.1.0/24"); ?>
Funciones de red
Tabla de contenidos
- checkdnsrr — Comprueba registros DNS correspondientes a un nombre de host de Internet dado o dirección IP
- closelog — Cerrar conexión al log del sistema
- dns_check_record — Alias de checkdnsrr
- dns_get_mx — Alias de getmxrr
- dns_get_record — Fetch DNS Resource Records associated with a hostname
- fsockopen — Abre una conexión vía sockets a Internet o a un dominio Unix
- gethostbyaddr — Obtener el nombre del host de Internet correspondiente a una dirección IP dada
- gethostbyname — Obtener la dirección IPv4 que corresponde a un nombre de host de Internet dado
- gethostbynamel — Obtener una lista de direcciones IPv4 que corresponde a un nombre de host de Internet dado
- gethostname — Obtiene el nombre de host
- getmxrr — Obtener los registros MX correspondientes a un nombre de host de Internet
- getprotobyname — Obtener el número de protocolo asociado con el nombre de protocolo
- getprotobynumber — Obtiene el nombre de protocolo asociado con un número de protocolo
- getservbyname — Obtener el número de puerto asociado con un servicio y protocolo de Internet
- getservbyport — Obtener el servicio de Internet que corresponde con el puerto y protocolo
- header_register_callback — Llamar a una función de cabecera
- header_remove — Elimina encabezados previamente establecidos
- header — Enviar encabezado sin formato HTTP
- headers_list — Devuelve una lista de encabezados de respuesta enviados (o listos para enviar)
- headers_sent — Comprueba si o donde han enviado cabeceras
- http_response_code — Obtener o establecer el código de respuesta HTTP
- inet_ntop — Convertir una dirección de internet empaquetada en una representación legible por humanos
- inet_pton — Convertir una dirección IP legible por humanos a su representación in_addr empaquetada
- ip2long — Convierte una cadena que contiene una dirección con puntos del Protocolo de Internet (IPv4) en una dirección apropiada
- long2ip — Convierte una dirección de red (IPv4) en una cadena de texto en formato con puntos estándar de internet
- net_get_interfaces — Get network interfaces
- openlog — Open connection to system logger
- pfsockopen — Abre Internet persistente o conexión de socket de dominio Unix
- setcookie — Enviar una cookie
- setrawcookie — Enviar una cookie sin codificar su valor
- socket_get_status — Alias de stream_get_meta_data
- socket_set_blocking — Alias de stream_set_blocking
- socket_set_timeout — Alias de stream_set_timeout
- syslog — Genera un mensaje log de sistema
add a note
User Contributed Notes 14 notes
claudiu at cnixs dot com ¶
17 years ago
Anton Avramov - lukav at lukav dot com ¶
7 years ago
An improved version of claudiu at cnixs dot com not using split and working with the following:
ip: 192.168.101.123, CIRD: 192.168.101.144/24
<?php
function ipCIDRCheck ($IP, $CIDR) {
list ($net, $mask) = explode ('/', $CIDR);
$ip_net = ip2long ($net);
$ip_mask = ~((1 << (32 - $mask)) - 1);
$ip_ip = ip2long ($IP);
return (($ip_ip & $ip_mask) == ($ip_net & $ip_mask));
}
?>
Anonymous ¶
8 years ago
improved version of philippe-at-cyberabuse.org's answer:
<?php
function cidrconv($net) {
$start = strtok($net,"/");
$n = 3 - substr_count($net, ".");
if ($n > 0)
{
for ($i = $n;$i > 0; $i--)
$start .= ".0";
}
$bits1 = str_pad(decbin(ip2long($start)), 32, "0", STR_PAD_LEFT);
$net = (1 << (32 - substr(strstr($net, "/"), 1))) - 1;
$bits2 = str_pad(decbin($net), 32, "0", STR_PAD_LEFT);
$final = "";
for ($i = 0; $i < 32; $i++)
{
if ($bits1[$i] == $bits2[$i]) $final .= $bits1[$i];
if ($bits1[$i] == 1 and $bits2[$i] == 0) $final .= $bits1[$i];
if ($bits1[$i] == 0 and $bits2[$i] == 1) $final .= $bits2[$i];
}
return array($start, long2ip(bindec($final)));
}
?>
David GASTALDIN ¶
17 years ago
Here a IP-Range to CIDRs function that I wrote for the purpose of filling my Postfix client.cidr with ripe-ncc data to block spamming from useless countries. Strcmp functions are meant to work around the silly PHP string comparison which inevitably tries compare strings as numbers when possible. I'll make no comment about that fact ... bit I have to bite my tong hard :
function PlageVersCIDRs($ip_min, $ip_max) {
$cidrs = array();
$ip_min_bin = sprintf('%032b', $ip_min);
$ip_max_bin = sprintf('%032b', $ip_max);
$ip_cour_bin = $ip_min_bin;
while (strcmp($ip_cour_bin, $ip_max_bin) <= 0) {
$lng_reseau = 32;
$ip_reseau_bin = $ip_cour_bin;
while (($ip_cour_bin[$lng_reseau - 1] == '0') && (strcmp(substr_replace($ip_reseau_bin, '1', $lng_reseau - 1, 1), $ip_max_bin) <= 0)) {
$ip_reseau_bin[$lng_reseau - 1] = '1';
$lng_reseau--;
}
$cidrs[] = long2ip(bindec($ip_cour_bin)).'/'.$lng_reseau;
$ip_cour_bin = sprintf('%032b', bindec($ip_reseau_bin) + 1);
}
return $cidrs;
}
philippe-at-cyberabuse.org ¶
23 years ago
PHP miss CIDR functions.
This one will convert a CIDR like this:
0.0.0.0/16 -> 0.0.0.0 - 0.0.255.255
127.0/16 -> 127.0.0.0 - 127.0.255.255
etc...
function cidrconv($net) {
$start=strtok($net,"/");
$n=3-substr_count($net, ".");
if ($n>0) { for ($i=$n;$i>0;$i--) $start.=".0"; }
$bits1=str_pad(decbin(ip2long($start)),32,"0","STR_PAD_LEFT");
$net=pow(2,(32-substr(strstr($net,"/"),1)))-1;
$bits2=str_pad(decbin($net),32,"0","STR_PAD_LEFT");
for ($i=0;$i<32;$i++) {
if ($bits1[$i]==$bits2[$i]) $final.=$bits1[$i];
if ($bits1[$i]==1 and $bits2[$i]==0) $final.=$bits1[$i];
if ($bits1[$i]==0 and $bits2[$i]==1) $final.=$bits2[$i];
}
return $start." - ".long2ip(bindec($final));
}
-dR ¶
9 years ago
This little function might come in handy
<?php
function cidr_range( $cidr, $chkip=null )
{
// Assign IP / mask
list($ip,$mask) = explode("/",$cidr);
// Sanitize IP
$ip1 = preg_replace( '_(\d+\.\d+\.\d+\.\d+).*$_', '$1', "$ip.0.0.0" );
// Calculate range
$ip2 = long2ip( ip2long( $ip1 ) - 1 + ( 1 << ( 32 - $mask) ) );
// are we cidr range cheking?
if ( $chkip != null && ! filter_var( $chkip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) === false )
{
return ip2long( $ip1 ) <= ip2long( $chkip ) && ip2long( $ip2 ) >= ip2long( $chkip ) ? true : false;
} else {
return "$ip1 - $ip2";
}
}
var_dump( cidr_range( "127.0/16", "127.0.0.1" ) ); // bool(true)
var_dump( cidr_range( "127.0/16", "192.168.0.1" ) ); // bool(false)
var_dump( cidr_range( "192.168.0.0/24" ) ); // string(27) "192.168.0.0 - 192.168.0.255"
?>
nexxer at rogers dot com ¶
19 years ago
In Trevor Hemsley's translation of the perl range2cidr function, the
while ($end > $start)
condition should be
while ($end >= $start)
otherwise it won't work for /32s, ie if you feed range2cidr("1.2.3.4", "1.2.3.4").
-- nex
Anonymous ¶
21 years ago
Alternative cidr_conv function - a little easier to follow
function cidr_conv($cidr_address) {
$first = substr($cidr_address, 0, strpos($cidr_address, "/"));
$netmask = substr(strstr($cidr_address, "/"), 1);
$first_bin = str_pad(decbin(ip2long($first)), 32, "0", STR_PAD_LEFT);
$netmask_bin = str_pad(str_repeat("1", (integer)$netmask), 32, "0", STR_PAD_RIGHT);
for ($i = 0; $i < 32; $i++) {
if ($netmask_bin[$i] == "1")
$last_bin .= $first_bin[$i];
else
$last_bin .= "1";
}
$last = long2ip(bindec($last_bin));
return "$first - $last";
}
samuele at norsam dot org ¶
21 years ago
To find if an IP is in a net/mask (very fast):
<?php
function isIPIn($ip,$net,$mask) {
$lnet=ip2long($net);
$lip=ip2long($ip);
$binnet=str_pad( decbin($lnet),32,"0","STR_PAD_LEFT" );
$firstpart=substr($binnet,0,$mask);
$binip=str_pad( decbin($lip),32,"0","STR_PAD_LEFT" );
$firstip=substr($binip,0,$mask);
return(strcmp($firstpart,$firstip)==0);
}
?>
This function can be compacted, avoiding some variable settings, but the function will not be too clear to read...
Example code, used to made a kind of location service network-based:
<?php
$n = array ( "192.168.0.0/16" => "TUSCANY",
"192.168.1.0/24" => "- Florence",
"192.168.2.0/24" => "- Pisa",
"192.168.3.0/24" => "- Siena",
"192.168.64.0/21" => "- Tuscan Archipelago",
"192.168.64.0/23" => "--- Elba Island",
"192.168.66.0/24" => "--- Capraia Island",
"192.168.67.0/24" => "--- Giannutri Island");
// Normally you should use the following line
$myip = $HTTP_SERVER_VARS['REMOTE_ADDR'];
// This is first example: returns Tuscany/Pisa
$myip = "192.168.2.33";
// This is second example: returns Tuscany/T.Arch./Elba
$myip = "192.168.65.34";
echo "Your position:<br />\n";
foreach ( $n as $k=>$v ) {
list($net,$mask)=split("/",$k);
if (isIPIn($myip,$net,$mask)) {
echo $n[$k]."<br />\n"; }
}
?>
and so on...
dand at ddchosting.com ¶
18 years ago
When I was working on a project I ran into this problem with redirecting. My solution is as follows:
header("Refresh: 5; url=../main/main.php?".session_id()."");
This allowed me to pass the session_id() which is used throughout site to make sure user has loged in.
I hope this helps!
metator at netcabo dot pt ¶
19 years ago
Regarding samuele's note:
You can get faster code if you apply directly what happens in network devices, such as routers. If you AND (logic operation) the remote ip against the local netmask the result will be the network ip if the remote ip is from the local network. Example:
192.168.0.16 = 11000000.10101000.00000000.00010000
& 255.255.255.0 = 11111111.11111111.11111111.00000000
--------------------------------------------------------------
192.168.0.0 = 11000000.10101000.00000000.00000000
And now the code. My example uses a html form where you place the values you want to test:
<HTML><HEAD><TITLE>Check IP</TITLE>
</HEAD><BODY>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
Hope you find this useful.
IP to check: <input type="text" name="ip"> <br>
Local network ip: <input type="text" name="net"> <br>
Local netmask: <input type="text" name="mask"> <br>
<input type="submit" name="check" value="Check it!">
</form>
<?php
/**
* @param string $ip IP to check in dotted decimal format
* @param string $net Network IP in dotted decimal format
* @param string $mask Netmask in dotted decimal format
* @returns true if the ip belongs to the network, false otherwise
**/
function isIPIn($ip, $net, $mask) {
//doesn't check for the return value of ip2long
$ip = ip2long($_POST['ip']);
$rede = ip2long($_POST['net']);
$mask = ip2long($_POST['mask']);
//AND
$res = $ip & $mask;
return ($res == $rede);
}
if (isset($_POST['check'])) {
echo isIPIn($_POST['ip'], $_POST['net'], $_POST['mask']) ? "IP IN.": "IP OUT.";
}
?>
</BODY><HTML>
anderson at piq dot com dot br ¶
21 years ago
If you want to get the interface of an IP, based on the local route table, use this.
function GetIfaceforIP($user_ip)
{
$route = "/bin/netstat -rn";
exec($route, $aoutput);
foreach($aoutput as $key => $line)
{
if($key > 1)
{
$line = ereg_replace("[[:space:]]+",",",$line);
list($network, $gateway, $mask, $flags, $mss, $window, $irtt, $iface) = explode(",", $line)
if((ip2long($user_ip) & ip2long($mask)) == ip2long($network))
{
return $iface;
}
}
}
}
trevor-hemsley at nospam dot dial dot pipex dot com ¶
22 years ago
Previous example of IP range to CIDR list does not cope with ranges as well as the perl Net::Netmask range2cidrlist() function. In PHP this looks like
<?
function imask($this)
{
// use base_convert not dechex because dechex is broken and returns 0x80000000 instead of 0xffffffff
return base_convert((pow(2,32) - pow(2, (32-$this)))), 10, 16);
}
function imaxblock($ibase, $tbit)
{
while ($tbit > 0)
{
$im = hexdec(imask($tbit-1));
$imand = $ibase & $im;
if ($imand != $ibase)
{
break;
}
$tbit--;
}
return $tbit;
}
function range2cidrlist($istart, $iend)
{
// this function returns an array of cidr lists that map the range given
$s = explode(".", $istart);
// PHP ip2long does not handle leading zeros on IP addresses! 172.016 comes back as 172.14, seems to be treated as octal!
$start = "";
$dot = "";
while (list($key,$val) = each($s))
{
$start = sprintf("%s%s%d",$start,$dot,$val);
$dot = ".";
}
$end = "";
$dot = "";
$e = explode(".",$iend);
while (list($key,$val) = each($e))
{
$end = sprintf("%s%s%d",$end,$dot,$val);
$dot = ".";
}
$start = ip2long($start);
$end = ip2long($end);
$result = array();
while ($end > $start)
{
$maxsize = imaxblock($start,32);
$x = log($end - $start + 1)/log(2);
$maxdiff = floor(32 - floor($x));
$ip = long2ip($start);
if ($maxsize < $maxdiff)
{
$maxsize = $maxdiff;
}
array_push($result,"$ip/$maxsize");
$start += pow(2, (32-$maxsize));
}
return $result;
}
?>
philippe-at-cyberabuse.org ¶
22 years ago
... and this one will do the opposite (o return NULL for invalid netblocks) :
1.0.0.0 1.0.255.255 -> 1.0.0.0/16
1.0.0.0 1.3.255.255 -> 1.0.0.0/14
192.168.0.0 192.168.0.255 -> 192.168.0.0/24
function ip2cidr($ip_start,$ip_end) {
if(long2ip(ip2long($ip_start))!=$ip_start or long2ip(ip2long($ip_end))!=$ip_end) return NULL;
$ipl_start=(int)ip2long($ip_start);
$ipl_end=(int)ip2long($ip_end);
if($ipl_start>0 && $ipl_end<0) $delta=($ipl_end+4294967296)-$ipl_start;
else $delta=$ipl_end-$ipl_start;
$netmask=str_pad(decbin($delta),32,"0","STR_PAD_LEFT");
if(ip2long($ip_start)==0 && substr_count($netmask,"1")==32) return "0.0.0.0/0";
if($delta<0 or ($delta>0 && $delta%2==0)) return NULL;
for($mask=0;$mask<32;$mask++) if($netmask[$mask]==1) break;
if(substr_count($netmask,"0")!=$mask) return NULL;
return "$ip_start/$mask";
}
