checking a valid ip address

[graziano]

Hello

I am using this to check an ip address string ..

<?php

$ip="120.120.126.126";
if ( ereg ('([0-9]{1,3}+\\.)+([0-9]{1,3}+\\.)+([0-9]{1,3}+\\.)+([0-9]{1,3})', $ip) )
{
echo  "ok";
}
else   {
echo  "invalid ip";
}
?>

But it's not working ...(it's reporting invalid ip instead of ok) ; anyone can help to find why it's not working ?

Thank you

[graziano]

this works fine

if (ereg ('^([0-9]+\\.)+([0-9]{1,3})+(\\.)+([0-9]{1,3})+(\\.)+[0-9]{1,3}$', $ip) )

however I cannot understand why the {1,3} are ignored (1231.123123123.1231.1233 is accepted)

[hand]

<?
$ip = "255.255.255.255";
$exp   = explode('.',$ip);
if ($exp[0]<=255 && $exp[1]<=255 && $exp[2]<=255 && ($exp[3]<=255 || strpos($exp[3],'0/'))
  && preg_match("!^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.(([0-9]{1,3}))$!",$ip)) {
      echo  "ok";
} else {
      echo  "$ip is an invalid ip";
}

// or if you also want to check ranges like 192.168.0.0/32

$ip = "255.255.255.255";
$exp   = explode('.',$ip);
if ($exp[0]<=255 && $exp[1]<=255 && $exp[2]<=255 && ($exp[3]<=255 || strpos($exp[3],'0/'))
  && preg_match("!^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.(([0-9]{1,3})|(0/32)|(0/16)|(0/8))$!",$ip)) {
      echo  "ok";
} else {
      echo  "$ip is an invalid ip or ip range";
}
?>

Another function to convert ip-address to ip-integer or ip-integer to ip-address

function ipconvert($ip) {
	$seper = "@";
	$exp   = explode('.',$ip);
	if ($exp[0]<=255 && $exp[1]<=255 && $exp[2]<=255 && ($exp[3]<=255 || strpos($exp[3],'0/')) && preg_match("!^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.(([0-9]{1,3})|(0/32)|(0/16)|(0/8))$!",$ip)) {
               	switch ($exp[3]) {
			case "0/32":
				$res  = $exp[0]*pow(256,3) + $exp[1]*pow(256,2) + $exp[2]*256;
				$resb = $res + 255*pow(256,0);
				$resb = $seper . $resb;
				break;
			case "0/16":
				$res  = $exp[0]*pow(256,3) + $exp[1]*pow(256,2);
				$resb = $res + 255*pow(256,0) + 255*pow(256,1);
				$resb = $seper . $resb;
				break;
			case "0/8":
				$res  = $exp[0]*pow(256,3);
				$resb = $res + 255*pow(256,0) + 255*pow(256,1) + 255*pow(256,2);
				$resb = $seper . $resb;
				break;
			default:
				$res  = $exp[0] * pow(256,3) + $exp[1] * pow(256,2) + $exp[2] * 256 + $exp[3];
			}
	} else {
		$exp = explode($seper,$ip);
		if ($exp[0] <= (pow(256,4)-1) && preg_match("!^([0-9]{1,10})$!",$exp[0])) {
    			$ip0 = intval(( $exp[0]                                                       )/pow(256,3));
    			$ip1 = intval(( $exp[0] - $ip0*pow(256,3)                                     )/pow(256,2));
   			$ip2 = intval(( $exp[0] - $ip0*pow(256,3) - $ip1*pow(256,2)                   )/pow(256,1));
    			$ip3 = intval(( $exp[0] - $ip0*pow(256,3) - $ip1*pow(256,2) - $ip2*pow(256,1) )%pow(256,1));
               		switch ($exp[1] - $exp[0]) {
			case (pow(256,1) - 1):
				$res = "$ip0.$ip1.$ip2.0/32";
				break;
			case (pow(256,2) - 1):
				$res = "$ip0.$ip1.$ip2.0/16";
				break;
			case (pow(256,3) - 1):
				$res = "$ip0.$ip1.$ip2.0/8";
				break;
			default:
				$res = "$ip0.$ip1.$ip2.$ip3";
			}
		}
	}
	return "${res}${resb}";
}

[graziano]

Originally posted by hand

<?
$ip = "255.255.255.255";
$exp   = explode('.',$ip);
if ($exp[0]<=255 && $exp[1]<=255 && $exp[2]<=255 && ($exp[3]<=255 || strpos($exp[3],'0/'))
  && preg_match("!^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.(([0-9]{1,3}))$!",$ip)) {
      echo  "ok";
} else {
      echo  "$ip is an invalid ip";
}

// or if you also want to check ranges like 192.168.0.0/32

$ip = "255.255.255.255";
$exp   = explode('.',$ip);
if ($exp[0]<=255 && $exp[1]<=255 && $exp[2]<=255 && ($exp[3]<=255 || strpos($exp[3],'0/'))
  && preg_match("!^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.(([0-9]{1,3})|(0/32)|(0/16)|(0/8))$!",$ip)) {
      echo  "ok";
} else {
      echo  "$ip is an invalid ip or ip range";
}
?>

Another function to convert ip-address to ip-integer or ip-integer to ip-address

function ipconvert($ip) {
	$seper = "@";
	$exp   = explode('.',$ip);
	if ($exp[0]<=255 && $exp[1]<=255 && $exp[2]<=255 && ($exp[3]<=255 || strpos($exp[3],'0/')) && preg_match("!^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.(([0-9]{1,3})|(0/32)|(0/16)|(0/8))$!",$ip)) {
               	switch ($exp[3]) {
			case "0/32":
				$res  = $exp[0]*pow(256,3) + $exp[1]*pow(256,2) + $exp[2]*256;
				$resb = $res + 255*pow(256,0);
				$resb = $seper . $resb;
				break;
			case "0/16":
				$res  = $exp[0]*pow(256,3) + $exp[1]*pow(256,2);
				$resb = $res + 255*pow(256,0) + 255*pow(256,1);
				$resb = $seper . $resb;
				break;
			case "0/8":
				$res  = $exp[0]*pow(256,3);
				$resb = $res + 255*pow(256,0) + 255*pow(256,1) + 255*pow(256,2);
				$resb = $seper . $resb;
				break;
			default:
				$res  = $exp[0] * pow(256,3) + $exp[1] * pow(256,2) + $exp[2] * 256 + $exp[3];
			}
	} else {
		$exp = explode($seper,$ip);
		if ($exp[0] <= (pow(256,4)-1) && preg_match("!^([0-9]{1,10})$!",$exp[0])) {
    			$ip0 = intval(( $exp[0]                                                       )/pow(256,3));
    			$ip1 = intval(( $exp[0] - $ip0*pow(256,3)                                     )/pow(256,2));
   			$ip2 = intval(( $exp[0] - $ip0*pow(256,3) - $ip1*pow(256,2)                   )/pow(256,1));
    			$ip3 = intval(( $exp[0] - $ip0*pow(256,3) - $ip1*pow(256,2) - $ip2*pow(256,1) )%pow(256,1));
               		switch ($exp[1] - $exp[0]) {
			case (pow(256,1) - 1):
				$res = "$ip0.$ip1.$ip2.0/32";
				break;
			case (pow(256,2) - 1):
				$res = "$ip0.$ip1.$ip2.0/16";
				break;
			case (pow(256,3) - 1):
				$res = "$ip0.$ip1.$ip2.0/8";
				break;
			default:
				$res = "$ip0.$ip1.$ip2.$ip3";
			}
		}
	}
	return "${res}${resb}";
}

[/B]

Great , thank you!

[MtPHP]

I think this would be easiest way...

<?php
$ip = $_SERVER['REMOTE_ADDR'];
$reqip = "ip.ip.ip.ip";
if($ip!=reqip)
{
echo "You jerk that's not the IP you need to view this damn page!";
} else {
echo "Hmmmm... Your using the right IP. I guess you can enter then!";
}
?>

P.S. No offense, but I think my echos are better than yours! lol!

[id10t]

I agree with the guy above. Lots easier to do it that way, just get the IP from the variable. Of course, if you want to check that it is a valid ip, you will need to check it against the series of allowed IPs, etc. Also, don't forget that while an IP may be valid, it may not be valid for certain uses - like the reserved non-routable addresses(10., etc), the packet radio email gateways (44. class A), etc.