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"); ?>
Funções da Network
Índice
- checkdnsrr — Checa os registros DNS correspondentes para o nome do host ou endereço IP informado
- closelog — Close connection to system logger
- dns_check_record — Sinônimo de checkdnsrr
- dns_get_mx — Sinônimo de getmxrr
- dns_get_record — Fetch DNS Resource Records associated with a hostname
- fsockopen — Abre uma conexão socket de domínio Unix ou Internet
- gethostbyaddr — Obtém nome do servidor de Internet correspondente ao endereço de IP fornecido
- gethostbyname — Obtenha o endereço IPv4 correspondente a um determinado nome de host da Internet
- gethostbynamel — Obtenha uma lista de endereços IPv4 correspondentes a um determinado nome de host da Internet
- gethostname — Gets the host name
- getmxrr — Get MX records corresponding to a given Internet host name
- getprotobyname — Get protocol number associated with protocol name
- getprotobynumber — Get protocol name associated with protocol number
- getservbyname — Get port number associated with an Internet service and protocol
- getservbyport — Get Internet service which corresponds to port and protocol
- header_register_callback — Call a header function
- header_remove — Remove cabeçalhos definidos anteriormente
- header — Send a raw HTTP header
- headers_list — Retorna uma lista de cabeçalhos de resposta enviados (ou prontos para enviar)
- headers_sent — Checks if or where headers have been sent
- http_response_code — Get or Set the HTTP response code
- inet_ntop — Converts a packed internet address to a human readable representation
- inet_pton — Converts a human readable IP address to its packed in_addr representation
- ip2long — Converts a string containing an (IPv4) Internet Protocol dotted address into a long integer
- long2ip — Converts a long integer address into a string in (IPv4) Internet standard dotted format
- net_get_interfaces — Get network interfaces
- openlog — Open connection to system logger
- pfsockopen — Open persistent Internet or Unix domain socket connection
- setcookie — Envia um cookie
- setrawcookie — Send a cookie without urlencoding the cookie value
- socket_get_status — Sinônimo de stream_get_meta_data
- socket_set_blocking — Sinônimo de stream_set_blocking
- socket_set_timeout — Sinônimo de stream_set_timeout
- syslog — Generate a system log message
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 $cidrs;
}
philippe-at-cyberabuse.org ¶
22 years ago
PHP miss CIDR functions.
This one will convert a CIDR like this:
0.0.0.0/16 -> 0.0.0.0 - 0.0.255.255
127.0/16 -> 127.0.0.0 - 127.0.255.255
etc...
function cidrconv($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 ¶
8 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 - $last";
}
samuele at norsam dot org ¶
20 years ago
To find if an IP is in a net/mask (very fast):
<?php
function isIPIn($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";
}
