Getting list IPs from CIDR notation in PHP

Question

Is there a way (or function/class) to get the list of IP addresses from a CIDR notation?

For example, I have 73.35.143.32/27 CIDR and want to get the list of all IP\

Answer 1

Hej. I also needed this function and I edit 1 other to return me list of all IP addresses from range. This will return list of IP addresses from CIDR Notation. Enjoy it ;)

<?php 

    $ip_addr_cidr = "192.256.0.0/16";
    $ip_arr = explode('/', $ip_addr_cidr);

    $bin = '';
    for($i=1;$i<=32;$i++) {
        $bin .= $ip_arr[1] >= $i ? '1' : '0';
    }
    $ip_arr[1] = bindec($bin);

    $ip = ip2long($ip_arr[0]);
    $nm = ip2long($ip_arr[1]);
    $nw = ($ip & $nm);
    $bc = $nw | (~$nm);

    echo "Number of Hosts:    " . ($bc - $nw - 1) . "<br/>";
    echo "Host Range:         " . long2ip($nw + 1) . " -> " . long2ip($bc - 1) . "<br/>". "<br/>";

    for($zm=1;($nw + $zm)<=($bc - 1);$zm++)
        {
        echo long2ip($nw + $zm).  "<br/>";
        }

    ?>

Answer 2

Highly recommend this PHP Lib: https://github.com/S1lentium/IPTools

It can manipulate network easily with many functions.

e.g. Iterate over Network IP adresses:

$network = Network::parse('192.168.1.0/24');
foreach($network as $ip) {
    echo (string)$ip . '<br>';
}

// output:
192.168.1.0
...
192.168.1.255

Answer 3

this returns an array of ips:

function get_list_ip($ip_addr_cidr){
    $ip_arr = explode("/", $ip_addr_cidr);    
    $bin = "";

    for($i=1;$i<=32;$i++) {
        $bin .= $ip_arr[1] >= $i ? '1' : '0';
    }

    $ip_arr[1] = bindec($bin);

    $ip = ip2long($ip_arr[0]);
    $nm = $ip_arr[1];
    $nw = ($ip & $nm);
    $bc = $nw | ~$nm;
    $bc_long = ip2long(long2ip($bc));

    for($zm=1;($nw + $zm)<=($bc_long - 1);$zm++)
    {
        $ret[]=long2ip($nw + $zm);
    }
    return $ret;
}

Answer 4

Fixed version of Kosmonaft script:

function get_list_ip($ip_addr_cidr){

        $ip_arr = explode("/", $ip_addr_cidr);    
        $bin = "";

        for($i=1;$i<=32;$i++) {
            $bin .= $ip_arr[1] >= $i ? '1' : '0';
        }

        $ip_arr[1] = bindec($bin);

        $ip = ip2long($ip_arr[0]);
        $nm = $ip_arr[1];
        $nw = ($ip & $nm);
        $bc = $nw | ~$nm;
        $bc_long = ip2long(long2ip($bc));

        echo "Number of Hosts:    " . ($bc_long - $nw - 1) . "<br/>";
        echo "Host Range:         " . long2ip($nw + 1) . " -> " . long2ip($bc - 1) . "<br/>". "<br/>";

        for($zm=1;($nw + $zm)<=($bc_long - 1);$zm++)
        {
            echo long2ip($nw + $zm).  "<br/>";
        }
    }

Answer 5

I come up with a better idea

$ip_from= long2ip(ip2long($ip)& (-1<<(32-$net_mask)));
$ip_to= long2ip(ip2long($ip)| (~(-1<<(32-$net_mask))));

P.S:$ip is a ipv4 address like 60.12.34.5;$net_mask is a int net mask like 25;

it's very fast because of the bit shift operation

Answer 6

I had some problems with the previous versions, various PHP errors like undefined offset etc.

I found what I think is a better way to do it without the errors as detailed below.

This takes IPV4 CIDR notation IP addresses and can be used to get the start/end IP addresses of the CIDR range or count the total number of IP addresses in a database of IP addresses.

    $count = 0;
    $result = $sia_db_con->query("SELECT `ip_address` FROM `ip4` WHERE `ip_ban_active`='True' ORDER BY ip4.added ASC");
while ($row = $result->fetch_array()) {
    $pos = strpos($row[0], "/");
    $ip_arr = [0 => substr($row[0], 0, $pos), 1 => substr($row[0], $pos+1)];
    $start = cidr2ip($ip_arr)[0];
    $end = cidr2ip($ip_arr)[1];
    $count = $count + (ip2long($end) - ip2long($start)) + 1;
}
    unset($result, $row, $pos, $ip_arr, $start, $end, $range);

function cidr2ip($cidr) {
    $start = ip2long($cidr[0]);
    $nm = $cidr[1];
    $num = pow(2, 32 - $nm);
    $end = $start + $num - 1;
    $range = [0 => $cidr[0], 1 => long2ip($end)];
    unset($start, $nm, $num, $end);
    return $range;
}

The secret here is the way in which I create the $ip_arr variable. Rather than using PHP explode, I set the array dimensions manually for each IP address. This is of course a database version of the code and cycles through all IP addresses in the database which meet the search criteria.