2017-06-08 11:01:01

by Grumbach, Emmanuel

[permalink] [raw]
Subject: [PATCH] mac80211: don't look at the PM bit of BAR frames

When a peer sends a BAR frame with PM bit clear, we should
not modify its PM state as madated by the spec in
802.11-20012 10.2.1.2.

Signed-off-by: Emmanuel Grumbach <[email protected]>
---
net/mac80211/rx.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index e48724a6725e..bb1e4bbf55e2 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1558,12 +1558,16 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
*/
if (!ieee80211_hw_check(&sta->local->hw, AP_LINK_PS) &&
!ieee80211_has_morefrags(hdr->frame_control) &&
+ !ieee80211_is_back_req(hdr->frame_control) &&
!(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
(rx->sdata->vif.type == NL80211_IFTYPE_AP ||
rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
- /* PM bit is only checked in frames where it isn't reserved,
+ /*
+ * PM bit is only checked in frames where it isn't reserved,
* in AP mode it's reserved in non-bufferable management frames
* (cf. IEEE 802.11-2012 8.2.4.1.7 Power Management field)
+ * BAR frames should be ignored as specified in
+ * IEEE 802.11-2012 10.2.1.2.
*/
(!ieee80211_is_mgmt(hdr->frame_control) ||
ieee80211_is_bufferable_mmpdu(hdr->frame_control))) {
--
2.9.3


2017-06-21 05:59:56

by Grumbach, Emmanuel

[permalink] [raw]
Subject: RE: [PATCH] mac80211: don't look at the PM bit of BAR frames

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2017-06-20 21:58:08

by Igor Mitsyanko

[permalink] [raw]
Subject: Re: [PATCH] mac80211: don't look at the PM bit of BAR frames

On 06/08/2017 04:00 AM, Emmanuel Grumbach wrote:
> When a peer sends a BAR frame with PM bit clear, we should
> not modify its PM state as madated by the spec in
> 802.11-20012 10.2.1.2.
>
> Signed-off-by: Emmanuel Grumbach <[email protected]>
> ---
> net/mac80211/rx.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index e48724a6725e..bb1e4bbf55e2 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -1558,12 +1558,16 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
> */
> if (!ieee80211_hw_check(&sta->local->hw, AP_LINK_PS) &&
> !ieee80211_has_morefrags(hdr->frame_control) &&
> + !ieee80211_is_back_req(hdr->frame_control) &&

BTW latest spec also notes that PSPOLL frame has PM bit reserved too,
because it may not result in ACK frame from AP.

> !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
> (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
> rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
> - /* PM bit is only checked in frames where it isn't reserved,
> + /*
> + * PM bit is only checked in frames where it isn't reserved,
> * in AP mode it's reserved in non-bufferable management frames
> * (cf. IEEE 802.11-2012 8.2.4.1.7 Power Management field)
> + * BAR frames should be ignored as specified in
> + * IEEE 802.11-2012 10.2.1.2.

Comment placement is a little confusing IMO. Maybe move
ieee80211_is_back_req() check to this position?

> */
> (!ieee80211_is_mgmt(hdr->frame_control) ||
> ieee80211_is_bufferable_mmpdu(hdr->frame_control))) {
>