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	Mon, 16 Jan 2012 08:02:09 -0500
Subject: Re: possible bug in sta_info.c : ieee80211_send_null_response
From: Johannes Berg <johannes@sipsolutions.net>
To: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
Cc: linux-wireless@vger.kernel.org
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Date: Mon, 16 Jan 2012 14:02:06 +0100
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On Mon, 2012-01-16 at 13:15 +0100, Marco Porsch wrote:

> ieee80211_xmit is called at the end of the function. Which then calls 
> ieee80211_set_qos_hdr.
> 
> But ieee80211_set_qos_hdr will completely overwrite the QoS header again.
> So, what is wrong here?

You, I think?


void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
                           struct sk_buff *skb)
...
                /* preserve EOSP bit */
                ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
...
                /* qos header is 2 bytes */
                *p++ = ack_policy | tid;   
                *p = ieee80211_vif_is_mesh(&sdata->vif) ?
                        (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8) :
0;


johannes