Programming

function FindProxyForURL(url,host)
{

// set chp1 and chp1 to the 2 xxxx proxies VIPS
// xxxx VIP
var chpv1="aa.bb.cc.dd:8080";
var chpv2="aa.bb.cc.dd:8080";

// Also set the real proxy P1 interfaces just in case
var chrp1="aa.bb.cc.dd:8080";
var chrp2="aa.bb.cc.dd:8080";
var shrp1="aa.bb.cc.dd:8080";

// Declare variables we use later
var proxyone;
var proxytwo;
var proxythree;
var proxyfour;

// Get client ip and store in var
var myip=myIpAddress();

// If client is unable to communicate with proxies, indicating out of office location,
// still allow connection to *.gov.uk sites by adding a fourth proxy as direct.
// 
// This does have the effect that if all proxies are unavailable client will attempt
// direct connection.  This will be denied by FW policy when in office and only
// allow connection to *.gov.uk sites if not.

// Not ideal due to PAC file timeouts, plus relies on office security to deny direct internet.
//
// Not done *.gov.uk* incase of *.gov.uk.scamdomain.com instances
if (shExpMatch(url, "*.gov.uk")) 
{
    var proxyfour="DIRECT";
}

// If ip is xxxxx range use proxy xxxxx first
// *** Correct IP range needed. Demo only ***
if ( (isInNet(myip, "10.10.10.0", "255.255.255.0")) || (isInNet(myip, "10.10.5.0", "255.255.255.0")) ) 
{
    var proxyone=shrp1;    // P1 Interface of xxxxx
    var proxytwo=chpv1;
    var proxythree=chpv2;
   
    // Return proxy order to stop processing

    // If 4th proxy defined (indicating *.gov.uk sites)
    if ( proxyfour != null ) {
        return "PROXY proxyone; PROXY proxytwo; PROXY proxythree; PROXY proxyfour";
    } else {
    // Not allowing direct attempt for any site
        return "PROXY proxyone; PROXY proxytwo; PROXY proxythree";
    } 
} 

// Now use main proxies based on odd/even

// find the 4th octet - 
var ipbits=myip.split(".");
var myseg=parseInt(ipbits[3]);

// If even use proxy1 first
if(myseg==Math.floor(myseg/2)*2) {
   var proxyone=chpv1;
   var proxytwo=chpv2;
   var proxythree=shrp1;
}
else {
// Must be odd use proxy2 first
   var proxyone=chpv2;
   var proxytwo=chpv1;
   var proxythree=shrp1;
}

// Return proxy order

// If 4th proxy defined 
if ( proxyfour == null ) {
    return "PROXY proxyone; PROXY proxytwo; PROXY proxythree; PROXY proxyfour";
} else {
    // Not allowing direct attempt for any site
    return "PROXY proxyone; PROXY proxytwo; PROXY proxythree";
}

} // End of FindProxyURL function.
// End

// Return proxy order

// If 4th proxy defined
if ( proxyfour != null ) {
        //Need to expose vars outside quotes
        return "PROXY "+proxyone+"\; PROXY "+proxytwo+"\; PROXY "+proxythree+"\; PROXY "+proxyfour;
} else {
        // Not allowing direct attempt for any site
        //return "PROXY proxyone; PROXY proxytwo; PROXY proxythree";
        //Need to expose vars outside quotes
        return "PROXY "+proxyone+"\; PROXY "+proxytwo+"\; PROXY "+proxythree;
}

// Now use main proxies based on odd/even

// find the 4th octet - 
var ipbits=myip.split(".");
var myseg=parseInt(ipbits[3]);

// If even use proxy1 first
if(myseg==Math.floor(myseg/2)*2) {
   var proxyone=chpv1;
   var proxytwo=chpv2;
   var proxythree=shrp1;
}
else {
// Must be odd use proxy2 first
   var proxyone=chpv2;
   var proxytwo=chpv1;
   var proxythree=shrp1;
}

	// split the IPv4 address into a 4 element array 
	var ipbits = myip.split(".");

	// make sure this is an IPv4 address, which is > 1
	if (ipbits.length > 1)
	{
		// we think we have an IPv4 address here
		// grab the 4th octet and convert it to a decimal
		var myseg = parseInt(ipbits[3]);
	} else {		
		// we have a potential IPv6 address here
		// split the IPv6 address into a 6 element array
		var ipbits = myip.split(":");

		if (ipbits.length > 1)
		{
			// looks like we have an IPv6 address here
			// grab the 6th octet and convert it from hex to decimal
			var myseg = parseInt(ipbits[5],16);
		} else {
			// NOT AN IPv6 either, so ODD it will be by us forcing it to a 1!!!
			var myseg = 1;
		}
	}


	// take the modulus 2 of the myseg where 1 = odd, 0 = even
	var mycalcseg = myseg % 2;

	if (mycalcseg == 1) {
		// ODD number (mycalcseg = 1)
		var proxyone = proxyONEip;
		var proxytwo = proxyTWOip;
	} else {
		// EVEN number (mycalcseg = 0)
		var proxyone = proxyTWOip;
		var proxytwo = proxyONEip;
	}