[RESOLVED] Check if valid IP Address

[Slyke]

Don't worry... figured it out!

function checkIPAddress($ipAddressCheck, $networkAddress, $subnetMask)
{
  $subnetBin=(pow(2,32)-1)-(pow(2,32-$subnetMask)-1);
  $firstIP=ip2long($networkAddress) & ($subnetBin);
  $NetworkLength=pow(2,32-$subnetMask)-1;
  $longIPAddressCheck = ip2long($ipAddressCheck);

  if ($longIPAddressCheck > $firstIP && $longIPAddressCheck < ($firstIP + $NetworkLength))
  {
    return "true";
  }
  else
  {
    return "false";
  }

}

[Slyke]

This is for longhand or shorthand subnet masks.

function checkIPAddress($ipAddressCheck, $networkAddress, $subnetMask)
{
  $shorthandSubnet=convertSubnetToShorthand($subnetMask); //Remove this line if you want $subnetMask to take shorthand subnet inputs (eg $subnetMask="8"; for /8 (255.0.0.0)
  $subnetBin=(pow(2,32)-1)-(pow(2,32-$shorthandSubnet)-1);
  $firstIP=ip2long($networkAddress) & ($subnetBin);
  $NetworkLength=pow(2,32-$shorthandSubnet)-1;
  $longIPAddressCheck = ip2long($ipAddressCheck);

  if ($longIPAddressCheck > $firstIP && $longIPAddressCheck < ($firstIP + $NetworkLength))
  {
    return "true";
  }
  else
  {
    return "false";
  }

}

function convertSubnetToShorthand($subnetMask)
{

  $subnetOctets=explode(".", $subnetMask, 4);
  $reconcatinateSubnetMaskCount="";

  for ($octetIndex = 0; $octetIndex <= 3; $octetIndex++)
  {
    $subnetBinaryIndex[$octetIndex]=decbin($subnetOctets[$octetIndex]);
    $reconcatinateSubnetMaskCount=$reconcatinateSubnetMaskCount . $subnetBinaryIndex[$octetIndex];
  }
  
  return substr_count($reconcatinateSubnetMaskCount, "1");

}