netdev - Re: wireless vs. alignment requirements

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 25 Nov 2007 22:01:21 +0800
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Johannes Berg <johannes@...solutions.net>
Cc:	dsd@...too.org, davem@...emloft.net, netdev@...r.kernel.org,
	linux-wireless@...r.kernel.org
Subject: Re: wireless vs. alignment requirements

On Sun, Nov 25, 2007 at 02:54:24PM +0100, Johannes Berg wrote:
>
> But I do have a choice where to fix it up and I'd prefer the drivers to
> do it where necessary. For that, the warning would work because it'd
> show driver authors that they need to fix something.

Fair enough.

> Hmm. I don't think so. Take an AP for example. It gets a lot of packets
> from stations. Now, if you're not QoS capable then all is well. But i
> you are and some stations are as well then all those stations send QoS
> packets (+2 bytes). Or take an AP connected via wireless (WPS), WPS has
> +6 bytes so I get all incoming upstream traffic with such unaligned
> headers.

The question is does this actually change all the time.  Let's
say you took a random sample of a second worth of IP packets
over wireless, what proportion of them are going to have the
same hardware header length modulo 4?

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html