From:   Alexander Wetzel <alexander@wetzel-home.de>
To:     johannes@sipsolutions.net
Cc:     linux-wireless@vger.kernel.org,
        Alexander Wetzel <alexander@wetzel-home.de>
Subject: [PATCH 1/2] mac80211: Fix Extended Key ID auto activation
Date:   Mon, 22 Apr 2019 23:34:11 +0200
Message-Id: <20190422213412.16533-1-alexander@wetzel-home.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

Only enable Extended Key ID support for drivers which are not supporting
crypto offload and also do not support A-MPDU.

While any driver using SW crypto from mac80211 is generally able to also
support Extended Key ID these drivers are likely to mix keyIDs in
AMPDUs when rekeying.

According to IEEE 802.11-2016 "9.7.3 A-MPDU contents" this is not
allowed.

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
---
 net/mac80211/main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 5d6b93050c0b..af73f42960fa 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1051,7 +1051,11 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		}
 	}
 
-	if (!local->ops->set_key ||
+	/* Enable Extended Key IDs when driver is either allowing it or only
+	 * supporting SW crypto without A-MPDU
+	 */
+	if (!(local->ops->set_key ||
+	      ieee80211_hw_check(hw, AMPDU_AGGREGATION)) ||
 	    ieee80211_hw_check(&local->hw, EXT_KEY_ID_NATIVE))
 		wiphy_ext_feature_set(local->hw.wiphy,
 				      NL80211_EXT_FEATURE_EXT_KEY_ID);
-- 
2.21.0