[MAC80211]: remove HW_KEY_IDX_INVALID

This patch makes the mac80211/driver interface rely only on the
IEEE80211_TXCTL_DO_NOT_ENCRYPT flag to signal to the driver whether
a frame should be encrypted or not, since mac80211 internally no
longer relies on HW_KEY_IDX_INVALID either this removes it, changes
the key index to be a u8 in all places and makes the full range of
the value available to drivers.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 20 insertions, 17 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 950a4827507f..652dced0f3ec 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -164,7 +164,6 @@ struct ieee80211_low_level_stats {
 /* Transmit control fields. This data structure is passed to low-level driver
  * with each TX frame. The low-level driver is responsible for configuring
  * the hardware to use given values (depending on what is supported). */
-#define HW_KEY_IDX_INVALID -1
 
 struct ieee80211_tx_control {
         int tx_rate; /* Transmit rate, given as the hw specific value for the
@@ -197,13 +196,13 @@ struct ieee80211_tx_control {
                                                   * long retry value */
         u32 flags;                             /* tx control flags defined
                                                 * above */
+        u8 key_idx;             /* keyidx from hw->set_key(), undefined if
+                                 * IEEE80211_TXCTL_DO_NOT_ENCRYPT is set */
         u8 retry_limit;         /* 1 = only first attempt, 2 = one retry, ..
                                  * This could be used when set_retry_limit
                                  * is not implemented by the driver */
         u8 power_level;         /* per-packet transmit power level, in dBm */
         u8 antenna_sel_tx;      /* 0 = default/diversity, 1 = Ant0, 2 = Ant1 */
-        s8 key_idx;             /* HW_KEY_IDX_INVALID = do not encrypt,
-                                 * other values: keyidx from hw->set_key() */
         u8 icv_len;             /* length of the ICV/MIC field in octets */
         u8 iv_len;              /* length of the IV field in octets */
         u8 tkip_key[16];        /* generated phase2/phase1 key for hw TKIP */
@@ -467,8 +466,7 @@ enum ieee80211_key_flags {
  *
  * @hw_key_idx: To be set by the driver, this is the key index the driver
  *      wants to be given when a frame is transmitted and needs to be
- *      encrypted in hardware. It defaults to %HW_KEY_IDX_INVALID which
- *      the driver may not use.
+ *      encrypted in hardware.
  * @alg: The key algorithm.
  * @flags: key flags, see &enum ieee80211_key_flags.
  * @keyidx: the key index (0-3)
@@ -476,8 +474,8 @@ enum ieee80211_key_flags {
  * @key: key material
  */
 struct ieee80211_key_conf {
-        int hw_key_idx;
         ieee80211_key_alg alg;
+        u8 hw_key_idx;
         u8 flags;
         s8 keyidx;
         u8 keylen;
@@ -686,9 +684,10 @@ struct ieee80211_ops {
          * selected by the low-level driver.
          *
          * Return 0 if the key is now in use, -EOPNOTSUPP or -ENOSPC if it
-         * couldn't be added; if you return 0 then hw_key_idx must be
-         * assigned to something other than HW_KEY_IDX_INVALID. When the cmd
-         * is DISABLE_KEY then it must succeed.
+         * couldn't be added; if you return 0 then hw_key_idx must be assigned
+         * to the hardware key index, you are free to use the full u8 range.
+         *
+         * When the cmd is DISABLE_KEY then it must succeed.
          *
          * Note that it is permissible to not decrypt a frame even if a key
          * for it has been uploaded to hardware, the stack will not make any
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index b10e33deb63e..dd6fc4aa3ff5 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -73,8 +73,6 @@ static void ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
                                        key->sdata->dev->dev_addr, addr,
                                        &key->conf);
 
-        WARN_ON(!ret && (key->conf.hw_key_idx == HW_KEY_IDX_INVALID));
-
         if (!ret)
                 key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
 
@@ -109,7 +107,6 @@ static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
                        key->conf.keyidx, MAC_ARG(addr), ret);
 
         key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
-        key->conf.hw_key_idx = HW_KEY_IDX_INVALID;
 }
 
 struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
@@ -132,7 +129,6 @@ struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
          * Default to software encryption; we'll later upload the
          * key to the hardware if possible.
          */
-        key->conf.hw_key_idx = HW_KEY_IDX_INVALID;
         key->conf.flags = 0;
         key->flags = 0;
 
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index e2ae1e1fcc7b..3d57e6d80f6d 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -430,8 +430,6 @@ ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
 {
         struct ieee80211_key *key;
 
-        tx->u.tx.control->key_idx = HW_KEY_IDX_INVALID;
-
         if (unlikely(tx->u.tx.control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT))
                 tx->key = NULL;
         else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
@@ -442,8 +440,10 @@ ieee80211_tx_h_select_key(struct ieee80211_txrx_data *tx)
                  !(tx->sdata->eapol && ieee80211_is_eapol(tx->skb))) {
                 I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
                 return TXRX_DROP;
-        } else
+        } else {
                 tx->key = NULL;
+                tx->u.tx.control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+        }
 
         if (tx->key) {
                 tx->key->tx_rx_count++;
@@ -724,6 +724,15 @@ ieee80211_tx_h_misc(struct ieee80211_txrx_data *tx)
                 }
         }
 
+        /*
+         * Tell hardware to not encrypt when we had sw crypto.
+         * Because we use the same flag to internally indicate that
+         * no (software) encryption should be done, we have to set it
+         * after all crypto handlers.
+         */
+        if (tx->key && !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
+                tx->u.tx.control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+
         return TXRX_CONTINUE;
 }
 
@@ -833,7 +842,6 @@ __ieee80211_parse_tx_radiotap(
          */
 
         control->retry_limit = 1; /* no retry */
-        control->key_idx = HW_KEY_IDX_INVALID;
         control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
                             IEEE80211_TXCTL_USE_CTS_PROTECT);
         control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT |