RE: ips : padding of ahs & data segment.

["Barry Reinhold" <bbrtrebia@mediaone.net>]

Santosh,
	I was not aware of any need to pad beyond the next word (adding 0-3
bytes)when we were working on the format. I agree that you can read the
standard to imply that any 4 byte boundary would be valid and the wording
could be tightened.

>-----Original Message-----
>From: owner-ips@ece.cmu.edu [mailto:owner-ips@ece.cmu.edu]On Behalf Of
>Santosh Rao
>Sent: Tuesday, October 23, 2001 2:00 PM
>To: IPS Reflector
>Subject: ips : padding of ahs & data segment.
>
>
>All,
>
>Can somebody clarify what the below wording is supposed to imply :
>
>3.2.2.2 AHSLength
>
>The AHS is padded to an integer number of 4 byte words.
>
>3.2.4 Data Segment
>
>The Data Segment is also padded to an integer number of 4 byte words.
>
>
>Does the above imply that there are EXACTLY 0 - 3 pad bytes so as to
>align the AHS and data segment to the nearest 4 byte aligned boundary,
>or can the AHS and data segment be aligned on any integer number of 4
>byte words ??
>
>For ex :
>Assume a data segment length of 41 bytes. Does the above wording imply
>that the data segment MUST be exactly padded to a length of 44 bytes, or
>does it allow for padding to 44, 48, 52, 56... bytes ? (multiple integer
>of 4 byte words.)
>
>My interpretation is that the wording is loose and allows for the latter
>(i.e. any multiple integer of 4 byte words.)
>
>However, in order for this to work, the padding must be to the next
>highest 4 byte word boundary beyond the ahs length or data segment
>length. i.e. The pad bytes MUST range between 0 - 3 bytes.
>
>I think the wording needs to be tightened to clarify this.
>
>Comments ?
>
>Thanks,
>Santosh
>
>
>--
>##################################
>Santosh Rao
>Software Design Engineer,
>HP-UX iSCSI Driver Team,
>Hewlett Packard, Cupertino.
>email : santoshr@cup.hp.com
>Phone : 408-447-3751
>##################################