[PATCH 5.4 064/152] mac80211: fix wrong 160/80+80 MHz setting

Greg Kroah-Hartman
2020-03-03T17:54:44Z

From: Shay Bar <shay.bar@celeno.com>

[ Upstream commit 33181ea7f5a62a17fbe55f0f73428ecb5e686be8 ]

Before this patch, STA's would set new width of 160/80+80 MHz based on AP capability only.
This is wrong because STA may not support > 80MHz BW.
Fix is to verify STA has 160/80+80 MHz capability before increasing its width to > 80MHz.

The "support_80_80" and "support_160" setting is based on:
"Table 9-272 — Setting of the Supported Channel Width Set subfield and Extended NSS BW
Support subfield at a STA transmitting the VHT Capabilities Information field"
>From "Draft P802.11REVmd_D3.0.pdf"

Signed-off-by: Aviad Brikman <aviad.brikman@celeno.com>
Signed-off-by: Shay Bar <shay.bar@celeno.com>
Link: https://lore.kernel.org/r/20200210130728.23674-1-shay.bar@celeno.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/util.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 739e90555d8b9..decd46b383938 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2993,10 +2993,22 @@ bool ieee80211_chandef_vht_oper(struct ieee80211_hw *hw,
int cf0, cf1;
int ccfs0, ccfs1, ccfs2;
int ccf0, ccf1;
+ u32 vht_cap;
+ bool support_80_80 = false;
+ bool support_160 = false;

if (!oper || !htop)
return false;

+ vht_cap = hw->wiphy->bands[chandef->chan->band]->vht_cap.cap;
+ support_160 = (vht_cap & (IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK |
+ IEEE80211_VHT_CAP_EXT_NSS_BW_MASK));
+ support_80_80 = ((vht_cap &
+ IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ) ||
+ (vht_cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ &&
+ vht_cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) ||
+ ((vht_cap & IEEE80211_VHT_CAP_EXT_NSS_BW_MASK) >>
+ IEEE80211_VHT_CAP_EXT_NSS_BW_SHIFT > 1));
ccfs0 = oper->center_freq_seg0_idx;
ccfs1 = oper->center_freq_seg1_idx;
ccfs2 = (le16_to_cpu(htop->operation_mode) &
@@ -3024,10 +3036,10 @@ bool ieee80211_chandef_vht_oper(struct ieee80211_hw *hw,
unsigned int diff;

diff = abs(ccf1 - ccf0);
- if (diff == 8) {
+ if ((diff == 8) && support_160) {
new.width = NL80211_CHAN_WIDTH_160;
new.center_freq1 = cf1;
- } else if (diff > 8) {
+ } else if ((diff > 8) && support_80_80) {
new.width = NL80211_CHAN_WIDTH_80P80;
new.center_freq2 = cf1;
}
--
2.20.1