[PATCH 4.9 104/172] mac80211: recalculate min channel width on VHT opmode changes

Greg Kroah-Hartman
2017-07-03T13:44:14Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit d2941df8fbd9708035d66d889ada4d3d160170ce ]

When an associated station changes its VHT operating mode this
can/will affect the bandwidth it's using, and consequently we
must recalculate the minimum bandwidth we need to use. Failure
to do so can lead to one of two scenarios:
1) we use a too high bandwidth, this is benign
2) we use a too narrow bandwidth, causing rate control and
actual PHY configuration to be out of sync, which can in
turn cause problems/crashes

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/mac80211/iface.c | 21 +++++++++++++++++++++
net/mac80211/rx.c | 9 +--------
net/mac80211/vht.c | 4 +++-
3 files changed, 25 insertions(+), 9 deletions(-)

--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -6,6 +6,7 @@
* Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
* Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
+ * Copyright (c) 2016 Intel Deutschland GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -1307,6 +1308,26 @@ static void ieee80211_iface_work(struct
} else if (ieee80211_is_action(mgmt->frame_control) &&
mgmt->u.action.category == WLAN_CATEGORY_VHT) {
switch (mgmt->u.action.u.vht_group_notif.action_code) {
+ case WLAN_VHT_ACTION_OPMODE_NOTIF: {
+ struct ieee80211_rx_status *status;
+ enum nl80211_band band;
+ u8 opmode;
+
+ status = IEEE80211_SKB_RXCB(skb);
+ band = status->band;
+ opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
+
+ mutex_lock(&local->sta_mtx);
+ sta = sta_info_get_bss(sdata, mgmt->sa);
+
+ if (sta)
+ ieee80211_vht_handle_opmode(sdata, sta,
+ opmode,
+ band);
+
+ mutex_unlock(&local->sta_mtx);
+ break;
+ }
case WLAN_VHT_ACTION_GROUPID_MGMT:
ieee80211_process_mu_groups(sdata, mgmt);
break;
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2923,17 +2923,10 @@ ieee80211_rx_h_action(struct ieee80211_r

switch (mgmt->u.action.u.vht_opmode_notif.action_code) {
case WLAN_VHT_ACTION_OPMODE_NOTIF: {
- u8 opmode;
-
/* verify opmode is present */
if (len < IEEE80211_MIN_ACTION_SIZE + 2)
goto invalid;
-
- opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
-
- ieee80211_vht_handle_opmode(rx->sdata, rx->sta,
- opmode, status->band);
- goto handled;
+ goto queue;
}
case WLAN_VHT_ACTION_GROUPID_MGMT: {
if (len < IEEE80211_MIN_ACTION_SIZE + 25)
--- a/net/mac80211/vht.c
+++ b/net/mac80211/vht.c
@@ -527,8 +527,10 @@ void ieee80211_vht_handle_opmode(struct

u32 changed = __ieee80211_vht_handle_opmode(sdata, sta, opmode, band);

- if (changed > 0)
+ if (changed > 0) {
+ ieee80211_recalc_min_chandef(sdata);
rate_control_rate_update(local, sband, sta, changed);
+ }
}

void ieee80211_get_vht_mask_from_cap(__le16 vht_cap,