On Mon, 2007-10-22 at 17:35 -0700, David Miller wrote: > Your code is rotating bit 15 down by one bit and bits 0-14 up by one > bit.
Yes, a 16 bit rotate left. There was a discussion a few years ago: http://oss.sgi.com/archives/netdev/2003-10/msg00734.html >From the spec: Implementers of DDP should treat generating the checksum as an optional feature. The 16-bit DDP checksum is computed as follows: CkSum := 0 ; FOR each datagram byte starting with the byte immediately following this Checksum field REPEAT the following algorithm: CkSum := CkSum + byte; (unsigned addition) Rotate CkSum left one bit, rotating the most significant bit in least significant bit; IF, at the end, CkSum = 0 THEN CkSum := $FFFF (all ones). Reception of a datagram with CkSum equal to 0 implies that a checksum is not performed. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
