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Date: Tue, 26 Apr 2005 22:38:42 -0700
From: Tim Kientzle <kientzle@freebsd.org>
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To: Jose M Rodriguez <josemi@freebsd.jazztel.es>
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cc: Sam Leffler <sam@errno.com>
cc: freebsd-current@freebsd.org
cc: Marcel Moolenaar <marcel@xcllnt.net>
Subject: Re: rigth crc32 implementation
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Jose M Rodriguez wrote:
> El Miércoles, 27 de Abril de 2005 00:19, Marcel Moolenaar escribió:
>>On Tue, Apr 26, 2005 at 01:01:32PM -0700, Sam Leffler wrote:
>>
>>>Note also there is CRC32 code of this sort in WEP and TKIP crypto
>>>modules in the net80211 support.
>>
>>Given the seperation of crc32() into crc32_raw() and crc32(), with
>>either crc32() only or otherwise both functions inlined, are there
>>any obstacles preventing the 802.11 code from using the ones in
>>src/sys/libkern?
> 
> at last, sys/dev/if_sbni have another implementation of what seems to be 
> a crc32 alg.

Be a little careful, please.  There are very many
different, incompatible "32-bit CRCs."  There are
just a few popular ones, so you can often combine
functions, but not always.

Any CRC implementation should clearly document
the generating polynomial and the preconditioning
and postconditioning assumptions.

Tim Kientzle