Subject: Re: [PATCH] mac80211: partially fix skb->cb use
From: Johannes Berg <johannes@sipsolutions.net>
To: Luis Carlos Cobo <luisca@cozybit.com>
Cc: linux-wireless <linux-wireless@vger.kernel.org>
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Date: Tue, 29 Jul 2008 13:51:28 +0200
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On Tue, 2008-07-29 at 13:42 +0200, Luis Carlos Cobo wrote:

> One of the options I was thinking about when implemented that was to do
> the forwarding in what was once equivalent to ieee80211_data_to_8023()
> function. Then we do not have to do 802.11->802.3->802.11 series of
> conversions, and we would send the frames to be forwarded directly to
> the master device, speeding up things a bit.

That sounds sane to me, then you don't need the cb at all, do you? Can
just send it to the master dev with skb->do_not_encrypt set, right?

In fact, looking at the code, there seems to be a bug with promisc, are
you sure it's allowed to netif_rx/dev_queue_xmit the same frame?

> I think the most elegant solution would be to add a rx handler to be run
> before ieee80211_data_to_8023() dealing with forwarding and sending
> frames directly to the master device.=20

That sounds reasonable.

> Would it make sense to deal there
> too with the forwarding for APs and VLAN interfaces done in
> ieee80211_deliver_skb?

I don't think so. AP mode doesn't really forward MPDUs but MSDUs, which
should make a difference when encryption is enabled.

johannes

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