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long2ip> <inet_pton
[edit] Last updated: Fri, 22 Jul 2011

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ip2long

(PHP 4, PHP 5)

ip2longConverts a string containing an (IPv4) Internet Protocol dotted address into a proper address

说明

int ip2long ( string $ip_address )

The function ip2long() generates an IPv4 Internet network address from its Internet standard format (dotted string) representation.

ip2long() will also work with non-complete IP addresses. Read » http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/libs/commtrf2/inet_addr.htm for more info.

参数

ip_address

A standard format address.

返回值

Returns the IPv4 address or FALSE if ip_address is invalid.

更新日志

版本 说明
5.2.10 Prior to this version, ip2long() would sometimes return a valid number even if passed an value which was not an (IPv4) Internet Protocol dotted address.
5.0.0 Prior to this version, ip2long() returned -1 on failure.

范例

Example #1 ip2long() Example

<?php
$ip 
gethostbyname('www.example.com');
$out "The following URLs are equivalent:<br />\n";
$out .= 'http://www.example.com/, http://' $ip '/, and http://' sprintf("%u"ip2long($ip)) . "/<br />\n";
echo 
$out;
?>

Example #2 Displaying an IP address

This second example shows how to print a converted address with the printf() function in both PHP 4 and PHP 5:

<?php
$ip   
gethostbyname('www.example.com');
$long ip2long($ip);

if (
$long == -|| $long === FALSE) {
    echo 
'Invalid IP, please try again';
} else {
    echo 
$ip   "\n";           // 192.0.34.166
    
echo $long "\n";           // -1073732954
    
printf("%u\n"ip2long($ip)); // 3221234342
}
?>

Example #3 IP validation

ip2long() should not be used as the sole form of IP validation. Combine it with long2ip():

<?php
// make sure IPs are valid. also converts a non-complete IP into
// a proper dotted quad as explained below.
$ip long2ip(ip2long("127.0.0.1")); // "127.0.0.1"
$ip long2ip(ip2long("10.0.0")); // "10.0.0.0"
$ip long2ip(ip2long("10.0.256")); // "10.0.1.0"
?>

注释

Note:

Because PHP's integer type is signed, and many IP addresses will result in negative integers on 32-bit architectures, you need to use the "%u" formatter of sprintf() or printf() to get the string representation of the unsigned IP address.

Note:

ip2long() will return FALSE for the IP 255.255.255.255 in PHP 5 <= 5.0.2. It was fixed in PHP 5.0.3 where it returns -1 (same as PHP 4).

参见

  • long2ip() - Converts an (IPv4) Internet network address into a string in Internet standard dotted format
  • sprintf() - Return a formatted string



long2ip> <inet_pton
[edit] Last updated: Fri, 22 Jul 2011
 
add a note add a note User Contributed Notes ip2long
bimal at sanjaal dot com 07-Jul-2011 09:08
The signed integers of PHP will produce a lot of negative values for ip2long. Here is what I did it to make sure that valid numbers enter into my database: INT(10) UNSIGNED.

<?php
# IP is: 192.168.0.224
$ip = sprintf("%u", ip2long(long2ip(ip2long($_SERVER['REMOTE_ADDR']))));

# It produces: 3232235744
?>

I can treat the $ip as string in PHP, while integer for MySQL.
The following works well - while converting back to IP, using the SQL:

SELECT INET_NTOA(3232235744) ip, INET_ATON('192.168.0.224') number;

The results are good: 192.168.0.224 and 3232235744 respectively.
anjo2 28-May-2011 04:13
In 32bits systems, you cannot convert ipv6 to long, but you can convert ip2bin and bin2ip

This function converts ipv4 and ipv6, returns false if ip is not valid

<?php
function ip2bin($ip)
{
    if(
filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false)
        return
base_convert(ip2long($ip),10,2);
    if(
filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) === false)
        return
false;
    if((
$ip_n = inet_pton($ip)) === false) return false;
   
$bits = 15; // 16 x 8 bit = 128bit (ipv6)
   
while ($bits >= 0)
    {
       
$bin = sprintf("%08b",(ord($ip_n[$bits])));
       
$ipbin = $bin.$ipbin;
       
$bits--;
    }
    return
$ipbin;
}

function
bin2ip($bin)
{
   if(
strlen($bin) <= 32) // 32bits (ipv4)
      
return long2ip(base_convert($bin,2,10));
   if(
strlen($bin) != 128)
       return
false;
  
$pad = 128 - strlen($bin);
   for (
$i = 1; $i <= $pad; $i++)
   {
      
$bin = "0".$bin;
   }
  
$bits = 0;
   while (
$bits <= 7)
   {
      
$bin_part = substr($bin,($bits*16),16);
      
$ipv6 .= dechex(bindec($bin_part)).":";
      
$bits++;
   }
   return
inet_ntop(inet_pton(substr($ipv6,0,-1)));
}
?>
hanguofeng at gmail dot com 13-Mar-2011 03:50
I've write an IPFilter class to check if a ip is in given ips.

<?php
class IPFilter
{
    private static
$_IP_TYPE_SINGLE = 'single';
    private static
$_IP_TYPE_WILDCARD = 'wildcard';
    private static
$_IP_TYPE_MASK = 'mask';
    private static
$_IP_TYPE_SECTION = 'section';
    private
$_allowed_ips = array();

    public function
__construct($allowed_ips)
    {
       
$this -> _allowed_ips = $allowed_ips;
    }

    public function
check($ip, $allowed_ips = null)
    {
       
$allowed_ips = $allowed_ips ? $allowed_ips : $this->_allowed_ips;

        foreach(
$allowed_ips as $allowed_ip)
        {
           
$type = $this -> _judge_ip_type($allowed_ip);
           
$sub_rst = call_user_func(array($this,'_sub_checker_' . $type), $allowed_ip, $ip);

            if (
$sub_rst)
            {
                return
true;
            }
        }

        return
false;
    }

    private function
_judge_ip_type($ip)
    {
        if (
strpos($ip, '*'))
        {
            return
self :: $_IP_TYPE_WILDCARD;
        }

        if (
strpos($ip, '/'))
        {
            return
self :: $_IP_TYPE_MASK;
        }

        if (
strpos($ip, '-'))
        {
            return
self :: $_IP_TYPE_SECTION;
        }

        if (
ip2long($ip))
        {
            return
self :: $_IP_TYPE_SINGLE;
        }

        return
false;
    }

    private function
_sub_checker_single($allowed_ip, $ip)
    {
        return (
ip2long($allowed_ip) == ip2long($ip));
    }

    private function
_sub_checker_wildcard($allowed_ip, $ip)
    {
       
$allowed_ip_arr = explode('.', $allowed_ip);
       
$ip_arr = explode('.', $ip);
        for(
$i = 0;$i < count($allowed_ip_arr);$i++)
        {
            if (
$allowed_ip_arr[$i] == '*')
            {
                return
true;
            }
            else
            {
                if (
false == ($allowed_ip_arr[$i] == $ip_arr[$i]))
                {
                    return
false;
                }
            }
        }
    }

    private function
_sub_checker_mask($allowed_ip, $ip)
    {
        list(
$allowed_ip_ip, $allowed_ip_mask) = explode('/', $allowed_ip);
       
$begin = (ip2long($allowed_ip_ip) &ip2long($allowed_ip_mask)) + 1;
       
$end = (ip2long($allowed_ip_ip) | (~ip2long($allowed_ip_mask))) + 1;
       
$ip = ip2long($ip);
        return (
$ip >= $begin && $ip <= $end);
    }

    private function
_sub_checker_section($allowed_ip, $ip)
    {
        list(
$begin, $end) = explode('-', $allowed_ip);
       
$begin = ip2long($begin);
       
$end = ip2long($end);
       
$ip = ip2long($ip);
        return (
$ip >= $begin && $ip <= $end);
    }
}
?>

useage:
<?php
$filter
= new IPFilter(
    array(
       
'127.0.0.1',
       
'172.0.0.*',
       
'173.0.*.*',
       
'126.1.0.0/255.255.0.0',
       
'125.0.0.1-125.0.0.9',
));
$filter -> check('126.1.0.2');
?>
ionisis dot com at TheSocialExpo dot com 20-Feb-2011 09:41
I've tried to get my comment in, but evidently it's still wider than the word wrap, even after repeated attempts to mitigate that... so i'll link to the post.

I wrote this function here to fully expand the user's ipv6 address, and then to convert it to decimal:

http://thesocialexpo.com/?a=SUBS_Blog_Display&id=12981930190593528

Note that if you don't care about it's fully expanded character representation, then wiessner's function below is probably better to just get the number.
me at iaincollins dot com 19-May-2010 10:37
I would just like to try and clear up simply that if storing IPV4 addresses in an SQL database you should use an unsigned int (4 bytes).

The easiest way to do this in PHP is to use sprintf():

<?php
 $dottedFormatAddress
= '127.0.0.1';
 
$ipv4address = sprintf("%u", ip2long($dottedFormatAddress));
?>

Primary reasons are it's compatible with database functions like MySQL's INET_ATON & INET_NTOA (which also use unsigned int's), it's efficient,  and it's the most common format used by IP lookup databases.
Mam(O)n 23-Jan-2010 11:37
Another CIDR function, but with sanity check:
<?php
function mask2prefix($mask)
{
    if ((
$long = ip2long($mask)) === false)
        return
false;
    for (
$prefix = 0; $long & 0x80000000; ++$prefix, $long <<= 1) {}
    if (
$long != 0)
        return
false;
    return
$prefix;
}
?>
joe at joeceresini dot com 25-Nov-2009 01:45
A quick method to convert a netmask (ex: 255.255.255.240) to a cidr mask (ex: /28):

<?php
function mask2cidr($mask){
 
$long = ip2long($mask);
 
$base = ip2long('255.255.255.255');
  return
32-log(($long ^ $base)+1,2);

 
/* xor-ing will give you the inverse mask,
      log base 2 of that +1 will return the number
      of bits that are off in the mask and subtracting
      from 32 gets you the cidr notation */
       
}
?>
f dot wiessner at smart-weblications dot net 07-Nov-2009 02:12
Here some working ip2long6 and long2ip6 functions - keep in mind that this needs php gmp-lib:

<?php

$ipv6
= "2001:4860:a005::68";

function
ip2long6($ipv6) {
 
$ip_n = inet_pton($ipv6);
 
$bits = 15; // 16 x 8 bit = 128bit
 
while ($bits >= 0) {
   
$bin = sprintf("%08b",(ord($ip_n[$bits])));
   
$ipv6long = $bin.$ipv6long;
   
$bits--;
  }
  return
gmp_strval(gmp_init($ipv6long,2),10);
}

function
long2ip6($ipv6long) {

 
$bin = gmp_strval(gmp_init($ipv6long,10),2);
  if (
strlen($bin) < 128) {
   
$pad = 128 - strlen($bin);
    for (
$i = 1; $i <= $pad; $i++) {
   
$bin = "0".$bin;
    }
  }
 
$bits = 0;
  while (
$bits <= 7) {
   
$bin_part = substr($bin,($bits*16),16);
   
$ipv6 .= dechex(bindec($bin_part)).":";
   
$bits++;
  }
 
// compress

 
return inet_ntop(inet_pton(substr($ipv6,0,-1)));
}

print
$ipv6long ip2long6($ipv6)."\n";
print
$ipv6 = long2ip6($ipv6long)."\n";

?>

outputs:

42541956150894553250710573749450571880
2001:4860:a005::68
david dot schueler at tel-billig dot de 27-Oct-2009 02:41
To get the network adress out of the broadcast adress and netmask just to an AND on it:

<?php
// simple example
$bcast = ip2long("192.168.178.255");
$smask = ip2long("255.255.255.0");
$nmask = $bcast & $smask;
echo
long2ip($nmask); // Will give 192.168.178.0
?>

With this example you are able to check if a given host is in your own local net or not (on linux):

<?php
/**
 * Check if a client IP is in our Server subnet
 *
 * @param string $client_ip
 * @param string $server_ip
 * @return boolean
 */
function clientInSameSubnet($client_ip=false,$server_ip=false) {
    if (!
$client_ip)
       
$client_ip = $_SERVER['REMOTE_ADDR'];
    if (!
$server_ip)
       
$server_ip = $_SERVER['SERVER_ADDR'];
   
// Extract broadcast and netmask from ifconfig
   
if (!($p = popen("ifconfig","r"))) return false;
   
$out = "";
    while(!
feof($p))
       
$out .= fread($p,1024);
   
fclose($p);
   
// This is because the php.net comment function does not
    // allow long lines.
   
$match  = "/^.*".$server_ip;
   
$match .= ".*Bcast:(\d{1,3}\.\d{1,3}i\.\d{1,3}\.\d{1,3}).*";
   
$match .= "Mask:(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})$/im";
    if (!
preg_match($match,$out,$regs))
        return
false;
   
$bcast = ip2long($regs[1]);
   
$smask = ip2long($regs[2]);
   
$ipadr = ip2long($client_ip);
   
$nmask = $bcast & $smask;
    return ((
$ipadr & $smask) == ($nmask & $smask));
}
?>
joshua_r108 at hotmail dot com 02-Aug-2009 06:30
I wrote something on the different ways to get an IP and convert it using ip2long(), the different ways to store an IP or an IP range in MySQL, and the different ways to query for the IP(s). Maybe something useful for others?

http://strictcoder.blogspot.com/2009_08_01_archive.html
Title: Query For An IP In A Database

Regards,
Joshua K Roberson
jwadhams1 at yahoo dot com 28-Jul-2009 10:41
I wanted to build on what kaputt and spinyn contributed in a way that I think is a little more intuitive (e.g., let sprintf do all the binary conversion and padding, and let substr_compare do the trimming and comparing):

<?php
function ip_in_network($ip, $net_addr, $net_mask){
    if(
$net_mask <= 0){ return false; }
       
$ip_binary_string = sprintf("%032b",ip2long($ip));
       
$net_binary_string = sprintf("%032b",ip2long($net_addr));
        return (
substr_compare($ip_binary_string,$net_binary_string,0,$net_mask) === 0);
}

ip_in_network("192.168.2.1","192.168.2.0",24); //true
ip_in_network("192.168.6.93","192.168.0.0",16); //true
ip_in_network("1.6.6.6","128.168.2.0",1); //false
?>
spinyn at gmail dot com 17-Apr-2009 02:51
Just want to add a comment to kaputt's valuable contribution to the task of matching hosts to ip ranges, efficiently.  The script works fine if the binary representation of the ip involves no leading zeros.  Unfortunately, the way decbin() seems to work, leading zeros in the binary representation of the first ip quad get dropped.  That is a serious matter if you're trying to match all possible candidates in the checklist.  In those cases the leading zeros need to be added back to get accurate matches for values in the first quad between 0-127 (or the binary equivalent, 0-01111111).

The solution I came up with to address this issue was the following function:

<?php
function addLeadingZero($ip) {
   if ((
$result = (32 - strlen($ip))) > 0)
      return
str_repeat("0", $result).$ip;
}
?>
Anonymous 18-Feb-2009 07:43
To always get the signed 32bit representation of an ip, I found this workaround:
<?php
list(, $ip) = unpack('l',pack('l',ip2long('200.200.200.200')));
?>

In this example, $ip will be -926365496 regardless of a 32 or 64 bit system.
randolf 20-Jan-2009 09:19
Convert IP to unsigned long

<?php
//$strIP  :   IP in String-format
//$lngIP  :   IP in unsigned long

if (($lngIP=ip2long($strIP)) < 0){ $lngIP += 4294967296 ;}

                                                      
// ADD 2^32

thats all.
?>
zuzana 05-Dec-2008 10:24
mysql has built-in functions inet_aton() and inet_ntoa() to convert ip to long and vice versa. you dont need to write any custom statements.
jbezorg at gmail dot com 20-Nov-2008 10:04
Had a need to convert IPs stored in VARCAR(15) to UINT in an old PHP application. Here are my tests for converting in a MySQL database so you don't have to reinvent the wheel.

#Dotted format to INT in MySQL

SET @ip_as_string = '198.128.128.0';
SELECT
    ( SUBSTRING_INDEX( @ip_as_string, '.', 1 )<<24 ) +
    ( SUBSTRING_INDEX( SUBSTRING_INDEX( @ip_as_string, '.', 2 ), '.', -1 )<<16 ) +
    ( SUBSTRING_INDEX( SUBSTRING_INDEX( @ip_as_string, '.', -2 ), '.', 1 )<<8 ) +
    SUBSTRING_INDEX(@ip_as_string, '.', -1) `IPvINT`;

#INT to dotted format in MySQL

SET @ip_as_long = 3330310144;
SELECT
    CONCAT( @ip_as_long>>24, '.', (@ip_as_long&16711680)>>16, '.', (@ip_as_long&65280)>>8, '.' , @ip_as_long&255 ) `IPv4`;
kaputt at starnet dot md 04-Nov-2008 07:47
Hi all!

I've maded simple script that allow you filter traffic by networks, like if you want to deny 192.168.0.0/24

I used ncritten's myip2long function for this.

Sorry for such non-optimized code, but it works enough good =)

file iplist.txt:
192.168.0.0/24
172.16.0.0/16
10.0.0.0/8

<?php
########### ncritten's function myip2long

function myip2long($ip) {
   if (
is_numeric($ip)) {
       return
sprintf("%u", floatval($ip));
   } else {
       return
sprintf("%u", floatval(ip2long($ip)));
   }
}

########### function to chek ip if it in one of denyied/allowed networks =)

function ipfilter($ip) {
  
$match = 0;

### converting ip address in binary
  
$ip_addr = decbin(myip2long($ip));

### the file wich contains allowed/denyied networks
  
if (fopen("iplist.txt", "r")) {
      
$source = file("iplist.txt");

       foreach (
$source as $line) {

### exploding each network to obtaid network address and cidr
          
$network = explode("/", $line);
          
$net_addr = decbin(myip2long($network[0]));
          
$cidr = $network[1];

### and finaly cheking quantity of network bits from left to right wich is equal to cidr is equal to the same bits of ip address
          
if (substr($net_addr, 0, $cidr) == substr($ip_addr, 0, $cidr)) {
              
$match = 1;
               break;
           }
       }
   }
   return
$match;
}

### this function will return 1 if IP match to some network or 0 if will not match

### and finaly the chek will be like this

$user_ip = $_SERVER['REMOTE_ADDR'];

if (
ipfilter($user_ip) == 1)  echo "allowed!";
else echo
"deny!";

?>

Good Luck!

P.S. Sorry for my bad english =)
Teguh Iskanto - Kamprettos at yahoo 29-Aug-2008 04:53
to Anonymous @ 29-Aug-2008 10:19

If you're speaking about efficiency, there's no absolute right / wrong as it all depends on the user's needs, specs and requirements.

But from what I'm coming from , this method served me well,  I've used this to match 2 network ends of approx 2700++ something unique VRFs (Nortel Shasta) and yes, each VRF is a virtualized firewall that consists of at least 20 different network objects (some could have couple of hundreds). Not to mention that these , still have to be compared with another hundreds of contivity boxes and each box have a range of around 1-600 vpn peers (to add more complexity, each peer has around 1-50 network ranges).

So, if you do the math, the number of permutations that need to be calculated, is indeed quite complex. I could get the whole result somewhere in around 50-65 secs tops.

Had I used a php function to crunch those data the result would have been longer.
Anonymous 29-Aug-2008 12:19
@Teguh Iskanto

Hi,

Your solution requires you to store the IP addresses and masks as strings, and also to store the subnet mask being used by your hosts.  This is very inefficient.

If you stored your network addresses as unsigned Integers, and your masks as TinyInts (i.e. a value between 0 & 32), you could instead do this:

select * from networks WHERE inet_aton('10.20.251.130') between `ipnumber` AND (`ipnumber` + (POW(2,(32-`mask`)))-1);

Obviously this can be made quicker on very high load systems by storing the broadcast address in the table instead of calculating it on the fly:

select * from networks WHERE inet_aton('10.20.251.130') between `ipnumber` AND `broadcast`;

Nick
ncritten at gmail dot youknowwhat 29-Aug-2008 11:58
Hi,
Please find below a little function I wrote for handling IP addresses as unsigned integers.
This function will take an IP address or IP number in ANY FORMAT (that I can think of) and will return it's decimal unsigned equivalent, as a string.

<?php
function myip2long($ip){
    if (
is_numeric($ip)){
        return
sprintf("%u", floatval($ip));
    } else {
        return
sprintf("%u", floatval(ip2long($ip)));
    }
}
?>

Here is is in action:

<?php
$ip
['DottedQuadDec'] = "192.168.255.109";
$ip['PosIntStr']     = "3232300909";
$ip['NegIntStr']     = "-1062666387";
$ip['PosInt']        = 3232300909;
$ip['NegInt']        = -1062666387;
$ip['DottedQuadHex'] = "0xc0.0xA8.0xFF.0x6D";
$ip['DottedQuadOct'] = "0300.0250.0377.0155";
$ip['HexIntStr']     = "0xC0A8FF6D";
$ip['HexInt']        = 0xC0A8FF6D;

printf("\n% 16s : % 20s => % 11s => % 16s","Input Type","Input Value","Converted","Converted Back");
echo
"\n    ------------------------------------------------------------------";
foreach (
$ip as $type => $value){
   
$ipnum = myip2long($value);
   
printf("\n% 16s : % 20s => % 11s => % 16s",$type,$value,$ipnum,long2ip($ipnum));
}
?>
Teguh Iskanto - Kamprettos_at_yahoo 27-Aug-2008 02:40
A quick way to find which IP address belong to which network , *without* even creating a single PHP function (pure SQL)

Scenario :
- I have one table that has a list of host ip addresses
- I have another table that list all the networks' addresses
- I need to find which host belongs to which network

nodes table
+-------------+-----------------+-------+
| ip          | mask            | name  |
+-------------+-----------------+-------+
| 192.168.1.1 | 255.255.255.0   | node1 |
| 192.168.1.1 | 255.255.255.252 | node2 |
| 192.168.2.1 | 255.255.255.252 | node3 |
+-------------+-----------------+-------+

network1 table
+-------------+---------------+------+
| ipaddr      | netmask       | name |
+-------------+---------------+------+
| 192.168.1.0 | 255.255.255.0 | net1 |
| 192.168.2.0 | 255.255.255.0 | net2 |
| 192.168.3.0 | 255.255.255.0 | net3 |
| 192.168.4.0 | 255.255.255.0 | net4 |
+-------------+---------------+------+

Solution 1 - with PHP ( Long ... ) :
1. create a PHP function that will calculate and compare IP address with the network
2. extract data from the table nodes, calculate the IP with its mask using a PHP function to get the network address
3.  do the same with table network1
4. compare result 2 and result 3 , once finished put them into an array to be presented as an HTML
5. done

Solution 2 - With SQL ( Very Very Fast & Short ) :
1. create sql with 'inet_aton' function + table joins
2. extract the data from sql outputs
3. done

how :
SQL :
select a.name as host_name,
a.ip as host_ip,
b.name as net_name
from nodes a, network1 b
where (inet_aton(a.ip) & inet_aton(a.mask) = inet_aton(b.ipaddr) & inet_aton(b.netmask));

Results :
Voilla ...
+-----------+-------------+----------+
| host_name | host_ip     | net_name |
+-----------+-------------+----------+
| node1     | 192.168.1.1 | net1     |
| node2     | 192.168.1.1 | net1     |
| node3     | 192.168.2.1 | net2     |
+-----------+-------------+----------+

Hope this helps
sy ABC damla.net 20-Jun-2008 10:57
Yes, but for safety wrapping it up with sprintf() does not hurt on 64bits either.
Anonymous 19-Jun-2008 03:09
on 64 bits system ip2long ONLY RETURNS POSITIVE VALUES

so

<?php
echo ip2long('200.200.200.200');
?>

will output -926365496 on a 32 bits system and 3368601800  on a 64 bits system
herwin at snt dot utwente nl 04-Jun-2008 03:50
The code examples explain why printing needs a casting, but beware that also calculations are performed with signed integers. In my case, the result of (ip2long('130.89.0.1') >> 24) was supposed to be 130, but the actual result was -126
chrisp-phpnet at inventivedingo dot com 31-May-2008 02:36
I had a problem with calling this function with REMOTE_ADDR on my lighttpd web server. Turned out that IPv6 was installed on this server, so even though REMOTE_ADDR was an IPv4 address, it was being formatted using IPv6's IPv4 compatibility mode. For example, 10.0.0.1 was becoming ::ffff:10.0.0.1, which caused iplong to report the address as invalid instead of parsing it correctly.

The correct fix would of course be to update my infrastructure so that it's properly IPv6-compatible; but in the context of my particular situation, this would involve a lot of re-engineering. So in the meantime, I worked around the issue using this quick and dirty hack:

<?php
    $ip
= htmlspecialchars($_SERVER['REMOTE_ADDR']);
    if (
strpos($ip, '::') === 0) {
       
$ip = substr($ip, strrpos($ip, ':')+1);
    }
   
$host = ip2long($ip);
?>

Ugly but functional.
jpmarcotte at gmail dot com 20-May-2008 10:10
In using a combination of jbothe's code below and some of the "$mask = 0xFFFFFFFF << (32 - $bits)" type code, I ran into an error with some later calculations on a 64 bit machine.

Keep in mind that when you're analyzing numbers meant to be treated as 32 bits wide (such as IP addresses), you may want to truncate them. Without relying on other libraries, it was simple enough to follow any calculations that may end with different results on a 64 bit machine with " & 0xFFFFFFFF"

Though in many cases, it seems like it might be simpler to just use "~0 << ..." for initial shifting to create the network mask instead of "0xFFFFFFFF << ...". I don't know that it guarantees further operations to work as expected though.
lutel 09-Apr-2008 11:45
here is netMatch function which is the fastest I could wrote, I hope developers will include native function soon...

<?php
function netMatch ($CIDR,$IP) {
    list (
$net, $mask) = explode ('/', $CIDR);
    return (
ip2long ($IP) & ~((1 << (32 - $mask)) - 1) ) == ip2long ($net);
}
?>
php dot net at kenman dot net 01-Apr-2008 06:02
To nate, who advises that there is no reason to use an unsigned version of the IP in a MySQL DB:

I think it would depend on your application, but personally, I find it useful to store IP's as unsigneds since MySQL has 2 native functions, INET_ATON() and INET_NTOA(), which work the same as ip2long()/long2ip() _except_ that they generate the unsigned counterpart. So if you want, you could do:

-- IANA Class-B reserved/private
SELECT * FROM `servers`
WHERE `ip` >= INET_ATON('192.168.0.0')
AND `ip` <= INET_ATON('192.168.255.255');

In my current application, I find it easier to use the MySQL built-ins than the PHP counter-parts.

In case you're curious as to the names ATON and NTOA:

ATON = address to number aka. ip2long
NTOA = number to address aka. long2ip
johniskew at yahoo dot com 24-Mar-2008 06:14
The following function ipToHex will take an IP (v4 or v6 formatted) and if it is valid, will return a 32 byte hex string representing that address.  Requires php >= 5.2 as it uses the filter_var function.

<?php

function ipToHex($ipAddress) {
   
$hex = '';
    if(
strpos($ipAddress, ',') !== false) {
       
$splitIp = explode(',', $ipAddress);
       
$ipAddress = trim($splitIp[0]);
    }
   
$isIpV6 = false;
   
$isIpV4 = false;
    if(
filter_var($ipAddress, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) !== false) {
       
$isIpV6 = true;
    }
    else if(
filter_var($ipAddress, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false) {
       
$isIpV4 = true;
    }
    if(!
$isIpV4 && !$isIpV6) {
        return
false;
    }
   
// IPv4 format
   
if($isIpV4) {
       
$parts = explode('.', $ipAddress);
        for(
$i = 0; $i < 4; $i++) {
           
$parts[$i] = str_pad(dechex($parts[$i]), 2, '0', STR_PAD_LEFT);
        }
       
$ipAddress = '::'.$parts[0].$parts[1].':'.$parts[2].$parts[3];
       
$hex = join('', $parts);
    }
   
// IPv6 format
   
else {
       
$parts = explode(':', $ipAddress);
       
// If this is mixed IPv6/IPv4, convert end to IPv6 value
       
if(filter_var($parts[count($parts) - 1], FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false) {
           
$partsV4 = explode('.', $parts[count($parts) - 1]);
            for(
$i = 0; $i < 4; $i++) {
               
$partsV4[$i] = str_pad(dechex($partsV4[$i]), 2, '0', STR_PAD_LEFT);
            }
           
$parts[count($parts) - 1] = $partsV4[0].$partsV4[1];
           
$parts[] = $partsV4[2].$partsV4[3];
        }
       
$numMissing = 8 - count($parts);
       
$expandedParts = array();
       
$expansionDone = false;
        foreach(
$parts as $part) {
            if(!
$expansionDone && $part == '') {
                for(
$i = 0; $i <= $numMissing; $i++) {
                   
$expandedParts[] = '0000';
                }
               
$expansionDone = true;
            }
            else {
               
$expandedParts[] = $part;
            }
        }
        foreach(
$expandedParts as &$part) {
           
$part = str_pad($part, 4, '0', STR_PAD_LEFT);
        }
       
$ipAddress = join(':', $expandedParts);
       
$hex = join('', $expandedParts);
    }
   
// Validate the final IP
   
if(!filter_var($ipAddress, FILTER_VALIDATE_IP)) {
        return
false;
    }
    return
strtolower(str_pad($hex, 32, '0', STR_PAD_LEFT));
}
$ips = array(
   
'::192.168.0.2',
   
'0:0:0:0:0:0:192.168.0.2',
   
'192.168.0.2',
   
'::C0A8:2',
   
'0:0:0:0:0:0:C0A8:2'
);
$finals = array();
foreach(
$ips as $ip) {
   
$finals[] = ipToHex($ip);
}
var_dump($finals);

?>
og_sam at homail dot com 16-Mar-2008 03:15
@ samb057 at gmail dot com

This function will not return a correct bigint.

base_convert() is limited to the double type,
which usually counts 64bits and not 128 like an IPv6 address.

For example:

FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF

will __NOT__ be converted to 128^2 -1

You should use a bigint lib's multiplication function,
with decimal shifting factors defined as string constants (much faster than recalculating them every time).
Grab 8 short integers (the 16bits between the ':' with base_convert($hex,16,10)) and shift the 7 higher ones with a bigint_multiplication.

Of course you can also do it with less bigint ops using 32bit integers, but then you should create them this way (additionally 'sprintf' for making an uint32 string):
$uint32= sprintf('%u',intval(base_convert($hex,16,10)));

Finally, "bigint_add" the shifted ones to the least (unshifted) significant interger string and be happy

PS: I'm working on an IPv4/6 tool class with raw (also endianness), 6/4 compatibility and validation methods,
I'll post it here as soon as it's finished and tested.
mhakopian at gmail dot com 11-Feb-2008 07:46
Just a little function to check visitor's ip if it is in given range or not (I couldn't find anywhere so i improvise):

<?php
function in_ip_range($ip_one, $ip_two=false){
    if(
$ip_two===false){
        if(
$ip_one==$_SERVER['REMOTE_ADDR']){
           
$ip=true;
        }else{
           
$ip=false;
        }
    }else{
        if(
ip2long($ip_one)<=ip2long($_SERVER['REMOTE_ADDR']) && ip2long($ip_two)>=ip2long($_SERVER['REMOTE_ADDR'])){
           
$ip=true;
        }else{
           
$ip=false;
        }
    }
    return
$ip;
}
//usage
echo in_ip_range('192.168.0.0','192.168.1.254');
?>
curda2 at hotmail dot com - Dim Works dot org 11-Feb-2008 07:01
The things that this function do is:

Structure of function:

<?php

$ip
= getenv(REMOTE_ADDR);
$numbers=explode (".",$ip);
$code=($numbers[0] * 16777216) + ($numbers[1] * 65536) + ($numbers[2] * 256) + ($numbers[3]);
//$code is the final variant

?>

that is similar to do this:

<?php

$ip
= getenv(REMOTE_ADDR);
$code=ip2long($ip);
//$code is the final variant

?>
dbemowsk 26-Jan-2008 03:41
A common way to express IP addresses and subnet masks is to use what is refered to as slash notation.  Instead of writing out:
IP = 192.168.100.2
Subnet Mask = 255.255.240.0
Writing out "192.168.100.2/20" is much shorter.

If you are looking for a way to convert a subnet mask into it's slash notation counterpart, here is a single line of code that can perform this task.

<?php
$slash_notation
= strlen(preg_replace("/0/", "", decbin(ip2long($subnet_mask))));
?>

For example...
A subnet mask of 255.255.240.0 expressed in binary looks like this:
11111111111111111111000000000000
This gives us a slash notation of 20 which is simply counting the number of 1's in the masks binary representation.

Here is a function that uses this code to return an IP address and subnet mask in slash notation.

<?php
function slash_notation($ip, $mask) {
  return
$ip."/".strlen(preg_replace("/0/", "", decbin(ip2long($mask))));
}
?>

calling slash_notation("192.168.100.2", "255.255.255.0"); will return "192.168.100.2/24".

Hope this is of use to some of you out there.
nate 18-Dec-2007 09:44
Thanks to sealbreaker for the conversion method. I'd seen <?php (ip2long($ip) & 0x7FFFFFFF) + 0x80000000 ?> before, but noticed it didn't work on all ips. You've discovered why. :)

In case anyone is wondering what sealbreaker means by obtaining an "integer value", s/he means an unsigned int, vs the signed version ip2long provides. Well, technically this conversion will sometimes give you a float since php's integer type is signed.

The good news is that long2ip will correctly handle converting these signed versions back into ips.

So, to get an unsigned version of an ip (ie, always >= 0):

<?php

$ip
= '127.0.0.1';

// may return a php int or float
$signed = substr($ip, 0, 3) > 127 ? ((ip2long($ip) & 0x7FFFFFFF) + 0x80000000) : ip2long($ip);

// will return a string version
$signed2 = sprintf('%u', ip2long($ip));

var_dump($signed, $signed2, long2ip($signed), long2ip($signed2));

?>

P.S.: If you're storing IPs in MySQL, there is NO POINT in converting to these unsigned values to place in an INT UNSIGNED column. Just use an INT SIGNED column, and directly use the result from ip2long. The only reason you should really need to force your ip2long result into its unsigned version is if you need to compare them with another source that uses unsigned (ie: some IP database lookup utils use unsigned).
sealbreaker at email dot com 03-Nov-2007 08:47
As a note : if you are using (PHP 4, PHP 5) and are looking to get the integer value of an IP address, i have found that the following works flawlessly for converting to and from IPv4 and it's integer equivalent. I must give credit elsewhere for this portion of the code (ip2long($ip) & 0x7FFFFFFF) + 0x80000000). I looked but was unable to find the comment where it was included.

$ip = "127.0.0.0"; // as an example

$integer_ip = (substr($ip, 0, 3) > 127) ? ((ip2long($ip) & 0x7FFFFFFF) + 0x80000000) : ip2long($ip);

echo $integer_ip; // integer value of IP address
echo long2ip($integer_ip); // convert to an IPv4 formatted address
-----------------------
Results are as follows:
-----------------------
2130706432
127.0.0.0
-----------------------
255.255.255.255 (converts to) 4294967295 (and back to) 255.255.255.255
209.65.0.0 (converts to) 3510697984 (and back to) 209.65.0.0
12.0.0.0 (converts to) 201326592 (and back to) 12.0.0.0
1.0.0.0 (converts to) 16777216 (and back to) 1.0.0.0
ir on ir id is at gm ai ld ot co m 21-Oct-2007 06:54
Keep in mind that storing IP addresses inside of your database as integers (rather than 15 character strings in decimal format, or 8 character strings in hex format) is hundreds of times faster.

Take the typical case of a MySQL database doing a search for an IP address on thousands (or millions!) of rows; you're either doing a string compare for each entry, or an integer equation. If you do your indexes correctly, your lookups should be literally 100x faster using an INT rather than a VARCHAR.

Also note that an integer doesn't need to be escaped when passed to a database. :)
andrew dot minerd at sellingsource dot com 21-Jul-2007 12:15
A somewhat more efficient alternative to convert the signed integer return by ip2long:

$float = ((ip2long($ip) & 0x7FFFFFFF) + 0x80000000);
one tiger one at gee mail dot comm 02-Apr-2007 02:49
I wrote a small function to validate a netmask (We have a form where the netmask of a given server is entered in, and I wanted to make sure it was valid). Hope this is useful.

<?php
// Netmask Validator //
function checkNetmask($ip) {
 if (!
ip2long($ip)) {
  return
false;
 } elseif(
strlen(decbin(ip2long($ip))) != 32 && ip2long($ip) != 0) {
  return
false;
 } elseif(
ereg('01',decbin(ip2long($ip))) || !ereg('0',decbin(ip2long($ip)))) {
  return
false;
 } else {
  return
true;
 }
}
?>
laacz at php dot net 16-Feb-2007 09:06
Just to save you some time.

Beware that octets in IP address are being treated as numbers. So, '10.0.0.11' is not equal to '10.0.0.011'. '011' is octal number (base 8), so it converts to '9'. You can even go further and see that '10.0.0.0xa' also works (equals to '10.0.0.16').

This is not PHP issue, though.
samb057 at gmail dot com 26-Dec-2006 08:37
Convert an ipv6 address to an base 10 integer

<?php
function ip2long6($ip)
    {
        if (
substr_count($ip, '::'))
            {
               
$ip = str_replace('::', str_repeat(':0000', 8 - substr_count($ip, ':')) . ':', $ip) ;
            }
           
       
$ip = explode(':', $ip) ;
       
       
$r_ip = '' ;
        foreach (
$ip as $v)
            {
               
$r_ip .= str_pad(base_convert($v, 16, 2), 16, 0, STR_PAD_LEFT) ;
            }
           
        return
base_convert($r_ip, 2, 10) ;
    }
?>
samb057 at gmail dot com 26-Dec-2006 08:20
Here's a simple IP address match checking function.

It takes 3 arguments: ip address to check (after ip2long), ip address to check against (after ip2long), and mask to check against (integer 0-32).

Just make sure you perform ip2long on the ip addresses before inputting them to the function.

<?php
function match_ip($check_ip, $match_ip, $match_mask = 32)
    {
        for (
$i = 0 ; $i < $match_mask ; $i++)
            {
               
$n = pow(2, 31 - $i) ;
                if ((
$n & $check_ip) != ($n & $match_ip))
                    {
                        return
FALSE ;
                    }
            }
           
        return
TRUE ;
    }
?>

I've been looking for a function like this for a while, i hope it helps someone.
Ian B 24-Dec-2006 12:22
NOTE: ip2long() should NOT be used for CIDR calculation.
Instead, you should use something like the following:

<?php
       
/* get the base and the bits from the ban in the database */
       
list($base, $bits) = explode('/', $CIDR);

       
/* now split it up into it's classes */
       
list($a, $b, $c, $d) = explode('.', $base);

       
/* now do some bit shfiting/switching to convert to ints */
       
$i = ($a << 24) + ($b << 16) + ($c << 8) + $d;
       
$mask = $bits == 0 ? 0 : (~0 << (32 - $bits));

       
/* here's our lowest int */
       
$low = $i & $mask;

       
/* here's our highest int */
       
$high = $i | (~$mask & 0xFFFFFFFF);

       
/* now split the ip were checking against up into classes */
       
list($a, $b, $c, $d) = explode('.', $iptocheck);

       
/* now convert the ip we're checking against to an int */
       
$check = ($a << 24) + ($b << 16) + ($c << 8) + $d;

       
/* if the ip is within the range, including
      highest/lowest values, then it's witin the CIDR range */
       
if ($check >= $low && $check <= $high)
            return
1;
       else
            return
0;
?>

This means that you should check to see if the IP
address is of the correct format each time.
jgwright 25-Oct-2006 07:13
Here is a modified version of the code posted by legetz81 (AT) yahoo (dot) com. It handles the shorter, and more common, notation: "189.128/11".

<?php

$ip_addr_cidr
= "192.168.37.215/27";
cidr($ip_addr_cidr);

function
cidr($ip_addr_cidr) {

$ip_arr = explode('/', $ip_addr_cidr);

$dotcount = substr_count($ip_arr[0], ".");
$padding = str_repeat(".0", 3 - $dotcount);
$ip_arr[0].=$padding;

$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 - $nw - 1) . "\n";
echo
"Host Range:        " . long2ip($nw + 1) . " -> " . long2ip($bc - 1)  . "\n";

/*
This will produce:
Number of Hosts:    30
Host Range:        192.168.37.193 -> 192.168.37.222
*/

}

?>
dh06 at biztechwiz dot com 24-Oct-2006 04:59
I made one tiny change to Stephane's routine below when I had problems with spaces in an IP range.  I moved the trim function before the ip2long call.

Thanks Stephane!

Dirk.

<?php
function netMatch($network, $ip) {

  
$network=trim($network);
  
$ip = trim($ip);

  
$d = strpos($network,"-");
   if (
$d===false) {
      
$ip_arr = explode('/', $network);
 
       if (!
preg_match("@\d*\.\d*\.\d*\.\d*@",$ip_arr[0],$matches)){
          
$ip_arr[0].=".0";    // Alternate form 194.1.4/24
      
}

      
$network_long = ip2long($ip_arr[0]);
      
$x = ip2long($ip_arr[1]);
         
      
$mask = long2ip($x) == $ip_arr[1] ? $x : (0xffffffff << (32 - $ip_arr[1]));
      
$ip_long = ip2long($ip);
 
       return (
$ip_long & $mask) == ($network_long & $mask);
   }
   else {
      
$from = ip2long(trim(substr($network,0,$d)));
      
$to = ip2long(trim(substr($network,$d+1)));

      
$ip = ip2long($ip);
       return (
$ip>=$from and $ip<=$to);
   }
}
?>
stephane at deluca dot biz 01-Oct-2006 08:40
I propose a new function to match an IP against a network.
You can define the network in two different manner, most suited for handling data grabed from WHOIS records:
- 202.1.192.0-202.1.192.255: a range of IPs
- 200.36.161.0/24: a range of IP by using net masking
- 200.36.161/24: a shorten syntax similar to the above.

Sdl

<?php
function netMatch($network, $ip) {

   
$network=trim($network);
   
$ip = trim($ip);

   
$d = strpos($network,"-");
    if (
$d===false) {
       
$ip_arr = explode('/', $network);
   
        if (!
preg_match("@\d*\.\d*\.\d*\.\d*@",$ip_arr[0],$matches)){
           
$ip_arr[0].=".0";    // Alternate form 194.1.4/24
       
}

       
$network_long = ip2long($ip_arr[0]);
       
$x = ip2long($ip_arr[1]);
           
       
$mask = long2ip($x) == $ip_arr[1] ? $x : (0xffffffff << (32 - $ip_arr[1]));
       
$ip_long = ip2long($ip);
   
        return (
$ip_long & $mask) == ($network_long & $mask);
    }
    else {
       
$from = trim(ip2long(substr($network,0,$d)));
       
$to = trim(ip2long(substr($network,$d+1)));

       
$ip = ip2long($ip);
        return (
$ip>=$from and $ip<=$to);
    }
}
?>
legetz81 (AT) yahoo (dot) com 30-Mar-2006 02:15
Here is a script that will calculate host range and number of hosts with a given ip address CIDR notation (modified code which was posted by phl AT cyways.com):

<?php
$ip_addr_cidr
= "192.168.37.215/27";
$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 - $nw - 1) . "\n";
echo
"Host Range:         " . long2ip($nw + 1) . " -> " . long2ip($bc - 1)  . "\n";
?>

This will produce:
Number of Hosts:    30
Host Range:         192.168.37.193 -> 192.168.37.222
01-Sep-2005 07:47
<?php
# m.ozarek
#
# Check if given mask is correct. You can check the short format mask
# like 8,16,24 or long format like 255.255.255.0
#

function isIpMask($mask){
   
   
$format = '';
    if(
preg_match("/[0-9]++\.[0-9]++\.[0-9]++\.[0-9]++/",$mask)){
       
$format = "long";
    }else{
        if(
$mask<=30){
           
$format = "short";
        }else{
            return
false;
        }
    }
    switch(
$format){
        case
long;
           
$mask = decbin(ip2long($mask));
        break;
        case
short:
           
$tmp = $mask;
            for(
$i=0; $i < $mask ;$i++){
               
$tmp.= 1;
            }
            for(
$j=0; $j < (32 - $mask);$j++){
               
$tmp.= 0;
            }
           
$mask = $tmp;
        break;
    }
    if(
strlen($mask) <= 32){
        for(
$i=0;$i<=32 ;$i++){
           
$bit = substr($mask,$i,1);
            if((
$bit - substr($mask,$i+1,1)) < 0){
                return
false;
            }
        }
    }
    return
true;
}
# EXAMPLE
# isIpMask("255.255.255.0") -> return true
# isIpMask("24") -> return true
# isIpMask("5.5.5.5") -> return false
?>

[EDIT BY danbrown AT php DOT net:  Contains a fix provided by (greg AT netops DOT gvtc DOT com) on 19-Dec-2005.]
ken at expitrans dot com 31-Aug-2005 10:31
Below is a merged form of all various notes, and a better (and correct) network matching function.

<?php

function net_match($network, $ip) {
     
// determines if a network in the form of 192.168.17.1/16 or
      // 127.0.0.1/255.255.255.255 or 10.0.0.1 matches a given ip
     
$ip_arr = explode('/', $network);
     
$network_long = ip2long($ip_arr[0]);

     
$x = ip2long($ip_arr[1]);
     
$mask long2ip($x) == $ip_arr[1] ? $x : 0xffffffff << (32 - $ip_arr[1]);
     
$ip_long = ip2long($ip);

     
// echo ">".$ip_arr[1]."> ".decbin($mask)."\n";
     
return ($ip_long & $mask) == ($network_long & $mask);
}

echo
net_match('192.168.17.1/16', '192.168.15.1')."\n"; // returns true
echo net_match('127.0.0.1/255.255.255.255', '127.0.0.2')."\n"; // returns false
echo net_match('10.0.0.1', '10.0.0.1')."\n"; // returns true

?>
tristram at ccteam dot ru 26-Jul-2005 01:33
<?php
if (!function_exists("ip2long"))
{
function
ip2long($ip)
{
 
$ip = explode(".",$ip);
 if (!
is_numeric(join(NULL,$ip)) or count($ip) != 4) {return false;}
 else {return
$ip[3]+256*$ip[2]+256*256*$ip[1]+256*256*256*$ip[0];}
}
}
?>
cam at wecreate dot com 20-Jul-2005 04:37
A simple function to compare two IP addresses against a netmask. Useful if you're locking down a web app with an IP address, but can't force the IPs to be exactly the same.

<?php
function ipcompare ($ip1, $ip2, $mask) {
   
$masked1 = ip2long($ip1) & ip2long($mask); // bitwise AND of $ip1 with the mask
   
$masked2 = ip2long($ip2) & ip2long($mask); // bitwise AND of $ip2 with the mask
     
if ($masked1 == $masked2) return true;
      else return
false;
}
?>

Examples:

<?php
  ipcompare
("192.168.1.63","192.168.1.65","255.255.255.0") // true
 
ipcompare("192.168.1.63","192.168.1.65","255.255.255.192") // false
?>
Paragina Silviu 12-Jul-2005 03:41
Note: ip2long and long2ip do not function as the c linux functions inet_addr and inet_ntoa. They store the long in reverse byte order (little endian vs big endian i guess).
For example you send 10.0.0.1 to inet_ntoa you take the long from the result and you pass it to long2ip  you get 1.0.0.10. You won't run into this issue unless you use a database both from c linux programs and php scripts.

My first idea was to reverse the long, but unfortunatley the long was stored as unsigned and i got a lot of problems doing calculations with it (some operations would work well others not; probably it was stored as float i do not know for sure...)

So my solution was

<?php
function str_rev_ip($str)
{
   
$ar=explode(".",$str);
    return
"$ar[3].$ar[2].$ar[1].$ar[0]";
}
?>

and i take the result from inet_ntoa and parse it as str_rev_ip(long2ip($var))
tomlove at gmail dot com 03-Jul-2005 11:09
A quick and efficient way to compare two IPs with a given mask:

<?php
function ipmatch ($ip1, $ip2, $mask) {
  if ((
ip2long($ip1) & ~(pow(2, 32-$mask)-1)) == (ip2long($ip2) & ~(pow(2, 32-$mask)-1))) return true;
  else return
false;
}
?>

Here's an application of it that selects the best IP given the choice of a (possibly private or invalid) forwarded address or a (possibly proxy) apparent address:

<?php
$a
= $_SERVER['HTTP_X_FORWARDED_FOR'];
if (
$a == '' || ipmatch($a, "10.0.0.0", 8) || ipmatch($a, "172.16.0.0", 12) || ipmatch($a, "192.168.0.0", 16) || ipmatch($a, "255.255.255.255", 32)) $ip = $_SERVER['REMOTE_ADDR'];
else
$ip = $a;
?>

Or use it to ban people:

<?php
$banned_ip
= '135.23.12.3';
if (
ipmatch($ip, $banned_ip, 32)) die('BANNED!');
?>

The bitwise comparison the function uses can be done in SQL to do ban matches right in your database.
lawpoop at gmail dot com 06-Apr-2005 10:29
Here is a function that tells you if an ip address is in a CIDR range. However, the CIDR argument can be an array of CIDRs. This was created from other matchCIDR functions in the user notes.

<?php
function matchCIDR($addr, $cidr) {

       
// $addr should be an ip address in the format '0.0.0.0'
        // $cidr should be a string in the format '100/8'
        //      or an array where each element is in the above format

       
$output = false;

        if (
is_array($cidr) ) {

                foreach (
$cidr as $cidrlet ) {
                        if (
matchCIDR( $addr, $cidrlet) ) {
                               
$output = true;
                        }
                }

        } else {

                list(
$ip, $mask) = explode('/', $cidr);

               
$mask = 0xffffffff << (32 - $mask);

               
$output = ((ip2long($addr) & $mask) == (ip2long($ip) & $mask));

        }

        return
$output;
}
?>
mailNO at SPAMdapuzz dot com 13-Feb-2005 07:05
a little function to make a range in this form:
0.0.0.1/0.0.0.255          ==> 0.0.0.1/255
0.0.0.1/255.255.255.255    ==> 0.0.0.1/255.255.255.255

<?php
$primo
= "62.4.32.0";
$ultimo = "62.4.63.255";
echo
do_range($primo,$ultimo); //Example

function do_range($primo,$ultimo) {
list(
$a,$b,$c,$d)=explode(".",$primo);
list(
$e,$f,$g,$h)=explode(".",$ultimo);
if (
$a !== $e) return "$primo/$ultimo";
else {
    if (
$b !== $f) return "$primo/$f.$g.$h";
    else{
        if (
$c !== $g) return "$primo/$g.$h";
        else {
            if (
$d !== $h) return "$primo/$h";
            else return -
1; //error
           
}
        }
    }
}
?>
Please write me if you have any suggestion
frank at vista dot com 27-Jan-2005 01:43
remixing mediator's function further:
<?php
function matchCIDR($addr, $cidr) {
  list(
$ip, $mask) = explode('/', $cidr);
  return (
ip2long($addr) >> (32 - $mask) == ip2long($ip) >> (32 - mask));
}
?>
01-Dec-2004 02:06
I re-wrote the functions from jbothe at hotmail dot com as a little exercise in OO and added a couple of extra functions.

<?php

 
//--------------
// IPv4 class
class ipv4
{
  var
$address;
  var
$netbits;

  
//--------------
  // Create new class
 
function ipv4($address,$netbits)
  {
   
$this->address = $address;
   
$this->netbits = $netbits;
  }

  
//--------------
  // Return the IP address
 
function address() { return ($this->address); }

  
//--------------
  // Return the netbits
 
function netbits() { return ($this->netbits); }

  
//--------------
  // Return the netmask
 
function netmask()
  {
    return (
long2ip(ip2long("255.255.255.255")
           << (
32-$this->netbits)));
  }

  
//--------------
  // Return the network that the address sits in
 
function network()
  {
    return (
long2ip((ip2long($this->address))
           & (
ip2long($this->netmask()))));
  }

  
//--------------
  // Return the broadcast that the address sits in
 
function broadcast()
  {
    return (
long2ip(ip2long($this->network())
           | (~(
ip2long($this->netmask())))));
  }

  
//--------------
  // Return the inverse mask of the netmask
 
function inverse()
  {
    return (
long2ip(~(ip2long("255.255.255.255")
           << (
32-$this->netbits))));
  }

}

 
$ip = new ipv4("192.168.2.1",24);
  print
"Address: $ip->address()\n";
  print
"Netbits: $ip->netbits()\n";
  print
"Netmask: $ip->netmask()\n";
  print
"Inverse: $ip->inverse()\n";
  print
"Network: $ip->network()\n";
  print
"Broadcast: $ip->broadcast()\n";
?>
daevid at daevid dot com 12-Nov-2004 03:30
This seems obvious in hindsight, but since nobody else posted it, it had me and two others scratching our heads. Thought I'd save someone else the trouble...

In mySQL, you can use the INET_ATON() function, but to save queries, you could use this function. However, the catch is that PHP returns negative values, so you have to use it like this:

$LongIP = sprintf('%u', ip2long($dotted_name));
DivineHawk 30-Oct-2004 07:38
For PHP5 I had to replace:
$mask_long= pow(2,32)-pow(2,(32-$ip_arr[1]));

-with-

$mask_long = 0xffffffff << (32 - $ip_arr[1]);

in dzver's IP_Match Function below.
mediator 02-Jun-2004 10:50
Another function for matching $_SERVER['REMOTE_ADDR'] against CIDR.
<?php
function matchCIDR($addr, $cidr) {
    list(
$ip, $mask) = explode('/', $cidr);
   
$mask = 0xffffffff << (32 - $mask);
    return ((
ip2long($addr) & $mask) == (ip2long($ip) & $mask));
}
?>
dzver 15-Apr-2004 12:12
Mix of rbsmith's function and pasted above url:

<?php
// returns 1 if $ip is part of $network

function IP_Match($network, $ip) {
   
$ip_arr = explode("/",$network);
   
$network_long=ip2long($ip_arr[0]);

   
$mask_long= pow(2,32)-pow(2,(32-$ip_arr[1]));
   
$ip_long=ip2long($ip);
 
    if ((
$ip_long & $mask_long) == $network_long) {
        return
1;
    } else {
        return
0;
    }
}

// usage

$network="200.100.50.0/23";
$ip="200.100.51.55";
$ip2="200.100.52.2";

echo
IP_Match($network, $ip); //prints 1
echo IP_Match($network, $ip2); //prints 0
?>
jbothe at hotmail dot com 27-Nov-2003 07:01
The following script will print out subnet statistics when you supply the IP Address and Subnet Mask. Usefull to calculate the broadcast address and network address as well as the number of hosts and the range of IP addresses in the subnet.

#!/usr/local/bin/php
<?php
   $ip_addr
= "172.14.1.57";
  
$subnet_mask = "255.255.255.0";

  
$ip = ip2long($ip_addr);
  
$nm = ip2long($subnet_mask);
  
$nw = ($ip & $nm);
  
$bc = $nw | (~$nm);

   echo
"IP Address:         " . long2ip($ip) . "\n";
   echo
"Subnet Mask:        " . long2ip($nm) . "\n";
   echo
"Network Address:    " . long2ip($nw) . "\n";
   echo
"Broadcast Address:  " . long2ip($bc) . "\n";
   echo
"Number of Hosts:    " . ($bc - $nw - 1) . "\n";
   echo
"Host Range:         " . long2ip($nw + 1) . " -> " . long2ip($bc - 1)  . "\n";
?>

Produces the output:

IP Address:         172.14.1.57
Subnet Mask:        255.255.255.0
Network Address:    172.14.1.0
Broadcast Address:  172.14.1.255
Number of Hosts:    254
Host Range:         172.14.1.1 -> 172.14.1.254
daevid at daevid dot com 14-Oct-2003 04:23
<?php
function CalculateIPRange($iprange)
{
   
// Daevid Vincent [daevid@daevid.com] 10.13.03
    //  This function will return an array of either a negative error code
    //  or all possible IP addresses in the given range.
    //  format is NNN.NNN.NNN.NNN - NNN.NNN.NNN.NNN  (spaces are okay)

   
$temp = preg_split("/-/",$iprange, -1, PREG_SPLIT_NO_EMPTY);
   
$QRange1 = $temp[0];
   
$QRange2 = $temp[1];

    if (
$QRange2 == "") return array($QRange1); //special case, they didn't put a second quad parameter

    //basic error handling to see if it is generally a valid IP in the form N.N.N.N
   
if ( preg_match("/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/",$QRange1) != 1 ) return array(-1);
    if (
preg_match("/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/",$QRange2) != 1 ) return array(-1);

   
$quad1 = explode(".",$QRange1);
   
$quad2 = explode(".",$QRange2);

   
reset ($quad1);
    while (list (
$key, $val) = each ($quad1))
    {
        
$quad1[$key] = intval($val);
         if (
$quad1[$key] < 0 || $quad1[$key] > 255) return array(-2);
    }
   
reset ($quad2);
    while (list (
$key, $val) = each ($quad2))
    {
        
$quad2[$key] = intval($val);
         if (
$quad2[$key] < 0 || $quad2[$key] > 255) return array(-2);
    }

   
$startIP_long = sprintf("%u",ip2long($QRange1));
   
$endIP_long = sprintf("%u",ip2long($QRange2));
   
$difference = $endIP_long - $startIP_long;
   
//echo "startIP_long = ".$startIP_long." and endIP_long = ".$endIP_long." difference = ".$difference."<BR>";

   
$ip = array();
   
$k = 0;
    for (
$i = $startIP_long; $i <= $endIP_long; $i++)
    {
       
$temp = long2ip($i);
       
       
//this is a total hack. there must be a better way.
       
$thisQuad = explode(".",$temp);
        if (
$thisQuad[3] > 0 && $thisQuad[3] < 255)
           
$ip[$k++] = $temp;
    }

    return
$ip;
}
//CalculateIPRange()
?>
anderson at piq dot com dot br 07-Aug-2003 05:02
If you want to get the interface of an IP, based on the local route table, use this.

<?php
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;
            }
        }
    }
}
?>
rbsmith 02-Jun-2003 01:29
Yet another word on IP_Match here is the complete functions
as described by php-net at dreams4net dot com on 08-Aug-2002 09:31

<?php
# determine if an IP address is within
# a particular network with mask
function IP_Match($network, $mask, $ip) {
   
$ip_long=ip2long($ip);
   
$network_long=ip2long($network);
   
$mask_long=ip2long($mask);
   
    if ((
$ip_long & $mask_long) == $network_long) {
        return
true;
    } else {
        return
false;
    }
}
?>

Thank you, it is simple, fast, and best of all works!
phl AT cyways.com 22-Oct-2001 11:36
Here's a function I whipped up today to deduce some important network information given a hostname (or its IP address) and its subnet mask:

<?php
function find_net($host,$mask) {
  
### Function to determine network characteristics
   ### $host = IP address or hostname of target host (string)
   ### $mask = Subnet mask of host in dotted decimal (string)
   ### returns array with
   ###   "cidr"      => host and mask in CIDR notation
   ###   "network"   => network address
   ###   "broadcast" => broadcast address
   ###
   ### Example: find_net("192.168.37.215","255.255.255.224")
   ### returns:
   ###    "cidr"      => 192.168.37.215/27
   ###    "network"   => 192.168.37.192
   ###    "broadcast" => 192.168.37.223
   ###

  
$bits=strpos(decbin(ip2long($mask)),"0");
  
$net["cidr"]=gethostbyname($host)."/".$bits;

  
$net["network"]=long2ip(bindec(decbin(ip2long(gethostbyname($host))) & decbin(ip2long($mask))));

  
$binhost=str_pad(decbin(ip2long(gethostbyname($host))),32,"0",STR_PAD_LEFT);
  
$binmask=str_pad(decbin(ip2long($mask)),32,"0",STR_PAD_LEFT);
   for (
$i=0; $i<32; $i++) {
      if (
substr($binhost,$i,1)=="1" || substr($binmask,$i,1)=="0") {
        
$broadcast.="1";
      }  else {
        
$broadcast.="0";
      }
   }
  
$net["broadcast"]=long2ip(bindec($broadcast));

   return
$net;
}
?>

 
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