Posted to tcl by kbk at Thu Oct 22 16:00:48 GMT 2009view pretty

proc inet_cksum8_kbk {data} {
    set sum 0
    binary scan $data cu* x
    if {[llength $x] & 1} {
	lappend x 0
    }
    foreach {v w} $x {
	set sum [expr {$sum + ($v << 8) + $w}]
	set sum [expr {($sum & 0xffff) | ($sum >> 16)}]
    }
    return $sum
}