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;
}
Fonctions réseaux
Sommaire
- checkdnsrr — Résolution DNS d'une adresse IP
- closelog — Ferme la connexion à l'historique système
- define_syslog_variables — Initialise toutes les variables relatives aux fonctions syslog
- dns_check_record — Alias de checkdnsrr
- dns_get_mx — Alias de getmxrr
- dns_get_record — Lit les données DNS associées à un hôte
- fsockopen — Ouvre une socket de connexion Internet ou Unix
- gethostbyaddr — Retourne le nom d'hôte correspondant à une IP
- gethostbyname — Retourne l'adresse IPv4 correspondant à un hôte
- gethostbynamel — Retourne la liste d'IPv4 correspondante à un hôte
- gethostname — Lit le nom de l'hôte
- getmxrr — Retourne les enregistrements MX d'un hôte
- getprotobyname — Retourne le numéro de protocole associé à un nom de protocole
- getprotobynumber — Retourne le nom de protocole associé à un numéro de protocole
- getservbyname — Retourne le numéro de port associé à un service Internet et un protocole
- getservbyport — Retourne le service Internet qui correspond au port et protocole
- header_remove — Supprime un entête HTTP
- header — Envoie un en-tête HTTP
- headers_list — Retourne la liste des en-têtes de réponse du script courant
- headers_sent — Indique si les en-têtes HTTP ont déjà été envoyés
- inet_ntop — Convertit un paquet d'adresses internet en une représentation humainement lisible
- inet_pton — Convertit une adresse IP lisible en sa représentation in_addr
- ip2long — Convertit une chaîne contenant une adresse (IPv4) IP numérique en adresse littérale
- long2ip — Convertit une adresse IP (IPv4) en adresse IP numérique
- openlog — Ouvre la connexion à l'historique système
- pfsockopen — Ouvre une socket de connexion Internet ou Unix persistante
- setcookie — Envoie un cookie
- setrawcookie — Envoie un cookie sans encoder sa valeur en URL
- 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 — Génère un message dans l'historique système
Fonctions réseaux
David GASTALDIN
21-Jun-2007 05:12
21-Jun-2007 05:12
claudiu at cnixs dot com
22-Apr-2007 11:52
22-Apr-2007 11:52
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"); ?>
dand at ddchosting.com
08-Apr-2006 11:28
08-Apr-2006 11:28
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
28-Jul-2005 04:34
28-Jul-2005 04:34
Ups. The function has a bug, though the example still works with it. Just replace the $_POST variables by the function parameters.
<?
function isIPIn($ip, $net, $mask) {
//doesn't check for the return value of ip2long
$ip = ip2long($ip);
$rede = ip2long($net);
$mask = ip2long($mask);
//AND
$res = $ip & $mask;
return ($res == $rede);
}
?>
metator at netcabo dot pt
28-Jul-2005 05:22
28-Jul-2005 05:22
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'], $_POST['mask']) ? "IP IN.": "IP OUT.";
}
?>
</BODY><HTML>
nexxer at rogers dot com
25-Feb-2005 02:16
25-Feb-2005 02:16
In Trevor Hemsley's translation of the perl range2cidr function, the
while ($end > $start)
condition should be
while ($end >= $start)
otherwise it won't work for /32s, ie if you feed range2cidr("1.2.3.4", "1.2.3.4").
-- nex
samuele at norsam dot org
25-Nov-2003 06:01
25-Nov-2003 06:01
To find if an IP is in a net/mask (very fast):
<?php
function isIPIn($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...
null at tty dot net dot ru
13-Oct-2003 01:51
13-Oct-2003 01:51
Ported Net::Netmask perl module:
http://null.pp.ru/src/php/Netmask.phps
anderson at piq dot com dot br
07-Aug-2003 07:10
07-Aug-2003 07:10
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 $iface;
}
}
}
}
03-Apr-2003 06:11
Alternative cidr_conv function - a little easier to follow
function cidr_conv($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 - $last";
}
trevor-hemsley at nospam dot dial dot pipex dot com
16-Oct-2002 08:53
16-Oct-2002 08:53
Previous example of IP range to CIDR list does not cope with ranges as well as the perl Net::Netmask range2cidrlist() function. In PHP this looks like
<?
function imask($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 $result;
}
?>
philippe-at-cyberabuse.org
13-Oct-2002 12:49
13-Oct-2002 12:49
... and this one will do the opposite (o return NULL for invalid netblocks) :
1.0.0.0 1.0.255.255 -> 1.0.0.0/16
1.0.0.0 1.3.255.255 -> 1.0.0.0/14
192.168.0.0 192.168.0.255 -> 192.168.0.0/24
function ip2cidr($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";
}
philippe-at-cyberabuse.org
15-Dec-2001 04:46
15-Dec-2001 04:46
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));
}
