mac80211: Simplify Extended Key ID API

1) Drop IEEE80211_HW_EXT_KEY_ID_NATIVE and let drivers directly set
   the NL80211_EXT_FEATURE_EXT_KEY_ID flag.

2) Drop IEEE80211_HW_NO_AMPDU_KEYBORDER_SUPPORT and simply assume all
   drivers are unable to handle A-MPDU key borders.

The new Extended Key ID API now requires all mac80211 drivers to set
NL80211_EXT_FEATURE_EXT_KEY_ID when they implement set_key() and can
handle Extended Key ID. For drivers not providing set_key() mac80211
itself enables Extended Key ID support, using the internal SW crypto
services.

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Link: https://lore.kernel.org/r/20190629195015.19680-2-alexander@wetzel-home.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

4 files changed, 14 insertions, 32 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index fbe1c29e3349..58941893a13f 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2268,12 +2268,6 @@ struct ieee80211_txq {
  * @IEEE80211_HW_SUPPORTS_ONLY_HE_MULTI_BSSID: Hardware supports multi BSSID
  *      only for HE APs. Applies if @IEEE80211_HW_SUPPORTS_MULTI_BSSID is set.
  *
- * @IEEE80211_HW_EXT_KEY_ID_NATIVE: Driver and hardware are supporting Extended
- *      Key ID and can handle two unicast keys per station for Rx and Tx.
- *
- * @IEEE80211_HW_NO_AMPDU_KEYBORDER_SUPPORT: The card/driver can't handle
- *      active Tx A-MPDU sessions with Extended Key IDs during rekey.
- *
  * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
  */
 enum ieee80211_hw_flags {
@@ -2325,8 +2319,6 @@ enum ieee80211_hw_flags {
         IEEE80211_HW_TX_STATUS_NO_AMPDU_LEN,
         IEEE80211_HW_SUPPORTS_MULTI_BSSID,
         IEEE80211_HW_SUPPORTS_ONLY_HE_MULTI_BSSID,
-        IEEE80211_HW_EXT_KEY_ID_NATIVE,
-        IEEE80211_HW_NO_AMPDU_KEYBORDER_SUPPORT,
 
         /* keep last, obviously */
         NUM_IEEE80211_HW_FLAGS
diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index 2e7f75938c51..47435f57e086 100644
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -271,8 +271,6 @@ static const char *hw_flag_names[] = {
         FLAG(TX_STATUS_NO_AMPDU_LEN),
         FLAG(SUPPORTS_MULTI_BSSID),
         FLAG(SUPPORTS_ONLY_HE_MULTI_BSSID),
-        FLAG(EXT_KEY_ID_NATIVE),
-        FLAG(NO_AMPDU_KEYBORDER_SUPPORT),
 #undef FLAG
 };
 
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index dd60f6428049..92c3affb0eb0 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -270,8 +270,7 @@ int ieee80211_set_tx_key(struct ieee80211_key *key)
 
         sta->ptk_idx = key->conf.keyidx;
 
-        if (ieee80211_hw_check(&local->hw, NO_AMPDU_KEYBORDER_SUPPORT))
-                clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
+        clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
         ieee80211_check_fast_xmit(sta);
 
         return 0;
@@ -289,16 +288,15 @@ static void ieee80211_pairwise_rekey(struct ieee80211_key *old,
         if (new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX) {
                 /* Extended Key ID key install, initial one or rekey */
 
-                if (sta->ptk_idx != INVALID_PTK_KEYIDX &&
-                    ieee80211_hw_check(&local->hw,
-                                       NO_AMPDU_KEYBORDER_SUPPORT)) {
+                if (sta->ptk_idx != INVALID_PTK_KEYIDX) {
                         /* Aggregation Sessions with Extended Key ID must not
                          * mix MPDUs with different keyIDs within one A-MPDU.
-                         * Tear down any running Tx aggregation and all new
-                         * Rx/Tx aggregation request during rekey if the driver
-                         * asks us to do so. (Blocking Tx only would be
-                         * sufficient but WLAN_STA_BLOCK_BA gets the job done
-                         * for the few ms we need it.)
+                         * Tear down running Tx aggregation sessions and block
+                         * new Rx/Tx aggregation requests during rekey to
+                         * ensure there are no A-MPDUs for the driver to
+                         * aggregate. (Blocking Tx only would be sufficient but
+                         * WLAN_STA_BLOCK_BA gets the job done for the few ms
+                         * we need it.)
                          */
                         set_sta_flag(sta, WLAN_STA_BLOCK_BA);
                         mutex_lock(&sta->ampdu_mlme.mtx);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 4c2702f128f3..29b9d57df1a3 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1048,21 +1048,15 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
                 }
         }
 
-        /* Enable Extended Key IDs when driver allowed it, or when it
-         * supports neither HW crypto nor A-MPDUs
+        /* Mac80211 and therefore all drivers using SW crypto only
+         * are able to handle PTK rekeys and Extended Key ID.
          */
-        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);
-
-        /* Mac80211 and therefore all cards only using SW crypto are able to
-         * handle PTK rekeys correctly
-         */
-        if (!local->ops->set_key)
+        if (!local->ops->set_key) {
                 wiphy_ext_feature_set(local->hw.wiphy,
                                       NL80211_EXT_FEATURE_CAN_REPLACE_PTK0);
+                wiphy_ext_feature_set(local->hw.wiphy,
+                                      NL80211_EXT_FEATURE_EXT_KEY_ID);
+        }
 
         /*
          * Calculate scan IE length -- we need this to alloc