Real-world IP v4 Check

<cfset sLocal = StructNew() />
<cfparam name="ip" default="">

<cfset objIP = createObject("java","coldfusion.util.IPAddressUtils") />

<h3>Enter a ip (or not :) ). Try 0.1.1.1, 0.0.0.0, 255.255.255.255, 192.168.0.0, 127.0.0.1, etc.</h3>
<h3>Currently <cfdump var="ip = #ip#"/></h3>

<cfform action="#cgi.SCRIPT_NAME#" format="html" method="post" name="myform">

    <p>username: <cfinput name="ip" value="#ip#" required="true" validate="NOBLANKS" ></p>
    <p><input type="submit"></p>

</cfform>

<cfif len(trim(ip))>
<cfset myIP = trim(ip) />

<p>Check using isIP UDF: <cfdump var="#isIP(myIP)#" /></p>

<p>Check using validIPAddress: <cfdump var="#validIpAddress(myIP)#" /></p>

<p>Check using Internal CF:
    <ul>
        <li>validateIPAdress: <cfdump var = "#objIp.validateIPAdress(myIP)#"></li>
        <li>validateIPv4Address: <cfdump var = "#objIp.validateIPv4Address(myIP)#"></li>
        <li>validateIPv6Address: <cfdump var = "#objIp.validateIPv6Address(myIP)#"></li>
    </ul>
</p>

<p>Using Joseph's UDF: <cfdump var="#isIPV4(myIP)#" /></p>

</cfif>



<cfscript>
/**
* Returns TRUE if the string is a valid IP address.
*
* @param string      String to be checked.
* @return Returns a boolean.
* @author Nathan Dintenfass (nathan@changemedia.com)
* @version 1, July 17, 2001
*/
function isIP(ip){
    var ii = 1;
    //make sure it is a '.' delimited list 4 long
    if(listlen(ip,".") is not 4) return false;

    //make sure each item is a number between 1 and 255
    for(ii = 1;ii lte 4;ii = ii + 1){
        if(not isnumeric(listgetat(ip,ii,".")) OR listgetat(ip,ii,".") GT 255 OR listgetat(ip,ii,".") LT 0)    return false;
    }
    //check for the special cases of 255.255.255.255 or 0.0.0.0, which is not really valid
    if(ip is "255.255.255.255" OR IP is "0.0.0.0") return false;
    return true;
}
</cfscript>

<cffunction name="validIpAddress" access="public" output="false" returntype="boolean" hint="returns T/F based on private rules for valid Ip address">
   <cfargument name="theIpAddress" type="string" required="false" default="" hint=""/>
      <cfset var pattern="^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)">
      <cfset var pattern2 = "^(10)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)">
      <cfset var pattern3 = "^(172)\.(1[6-9]|2[0-9]|3[0-1])\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)">
      <cfset var pattern4 = "^(192)\.(168)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)">

      <cfif !REFindNoCase(pattern,arguments.theIpAddress)>
         <cfreturn false />
      </cfif>

      <cfif !len(trim(arguments.theIpAddress))>
         <cfreturn false />
      </cfif>
      <cfif arguments.theIpAddress eq "0.0.0.0" or arguments.theIpAddress eq "127.0.0.1" or arguments.theIpAddress eq "255.255.255.255">
         <cfreturn false />
      </cfif>

      <cfif REFindNoCase(pattern2,arguments.theIpAddress)>
         <cfreturn false />
      </cfif>

      <cfif REFindNoCase(pattern3,arguments.theIpAddress)>
         <cfreturn false />
      </cfif>

      <cfif REFindNoCase(pattern4,arguments.theIpAddress)>
         <cfreturn false />
      </cfif>

   <cfreturn true />
</cffunction>

<!--- Written by Joseph Lamoree. Modified by Sami Hoda. --->
<cffunction name="isIPV4" returntype="boolean" access="public" output="false">
    <cfargument name="ip" type="string" required="true"/>

    <cfset var ba = arrayNew(1)/>
    <cfset var b = ""/>

    <cfif reFind("[^0-9\.]", trim(arguments.ip)) gt 0>
        <cfreturn false/>
    </cfif>

    <cfset ba = listToArray(trim(arguments.ip), ".")/>
    <!--- Should have four bytes --->
    <cfif not arrayLen(ba) eq 4>
        <cfreturn false/>
    </cfif>

    <!--- First and last bytes should be non-zero --->
    <cfif val(ba[1]) eq 0 or val(ba[4]) eq 0>
        <cfreturn false/>
    </cfif>

    <!--- Not all bytes should be 255 --->
    <cfif (val(ba[1]) eq 255) AND (val(ba[2]) eq 255) AND (val(ba[3]) eq 255) AND (val(ba[4]) eq 255) >
        <cfreturn false/>
    </cfif>

    <cfloop array="#ba#" index="b">
        <!--- No bytes should have leading zeros --->
        <cfif len(b) gt 1 and left(b, 1) eq 0>
            <cfreturn false/>
        </cfif>
        <!--- No bytes should be greater than 255 --->
        <cfif val(b) gt 255>
            <cfreturn false/>
        </cfif>
    </cfloop>

    <cfreturn true/>
</cffunction>