F5 Cookie encoding

After some trial and error, I got the following and it seems to be working...

 

 

I will appreciate any comments/corrections!

 

 

$nodePort is in format: XXXX

 

$nodeIP is in format: XXX.XXX.XXX.XXX

 

 

 

Encode the Port for F5

 

set a $nodePort

 

set b [expr {[expr {($a) & 0xff00}] >> 8}]

 

set c [expr {[expr {($a) & 0x00ff}] << 8}]

 

set encodedPort [expr {$b+$c}]

 

if { $::DebugFlag } {log LOCAL0. "nodePort: $a, b: $b, c: $c, encodedPort: $encodedPort" }

 

 

Encode the IP for F5

 

set ip [split $nodeIP "."]

 

set a [getfield $ip " " 1]

 

set b [getfield $ip " " 2]

 

set c [getfield $ip " " 3]

 

set d [getfield $ip " " 4]

 

 

set b1 [expr {$b << 8}]

 

set c1 [expr {$c << 12}]

 

set d1 [expr {$d << 24}]

 

 

if { $::DebugFlag } {log LOCAL0. "a: $a, b1: $b1, c1: $c1, d1: $d1"}

 

 

set encodedIP [expr {$a + [expr {$b << 8}] + [expr {$c << 16}] + [expr {$d << 24}]}]

 

if { $::DebugFlag } {log LOCAL0. "nodeIP: $nodeIP, a: $a, b: $b, c: $c, d: $d, and encodedIP=$encodedIP" }

 

 

set encodedIPPort "$encodedIP.$encodedPort.0000"

 

if { $::DebugFlag } {log LOCAL0. "F5 encodedIP and Port: $encodedIPPort"}