mac80211: add option to generate CCMP IVs only for mgmt frames

Some chips can encrypt managment frames in HW, but
require generated IV in the frame. Add a key flag
that allows us to achieve this.

Signed-off-by: Marek Kwaczynski <marek.kwaczynski@tieto.com>
[use BIT(0) to fill that spot, fix indentation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1202,14 +1202,18 @@ struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev);
  *	fall back to software crypto. Note that this flag deals only with
  *	RX, if your crypto engine can't deal with TX you can also set the
  *	%IEEE80211_KEY_FLAG_SW_MGMT_TX flag to encrypt such frames in SW.
+ * @IEEE80211_KEY_FLAG_GENERATE_IV_MGMT: This flag should be set by the
+ *	driver for a CCMP key to indicate that is requires IV generation
+ *	only for managment frames (MFP).
  */
 enum ieee80211_key_flags {
-	IEEE80211_KEY_FLAG_GENERATE_IV	= 1<<1,
-	IEEE80211_KEY_FLAG_GENERATE_MMIC= 1<<2,
-	IEEE80211_KEY_FLAG_PAIRWISE	= 1<<3,
-	IEEE80211_KEY_FLAG_SW_MGMT_TX	= 1<<4,
-	IEEE80211_KEY_FLAG_PUT_IV_SPACE = 1<<5,
-	IEEE80211_KEY_FLAG_RX_MGMT	= 1<<6,
+	IEEE80211_KEY_FLAG_GENERATE_IV_MGMT	= BIT(0),
+	IEEE80211_KEY_FLAG_GENERATE_IV		= BIT(1),
+	IEEE80211_KEY_FLAG_GENERATE_MMIC	= BIT(2),
+	IEEE80211_KEY_FLAG_PAIRWISE		= BIT(3),
+	IEEE80211_KEY_FLAG_SW_MGMT_TX		= BIT(4),
+	IEEE80211_KEY_FLAG_PUT_IV_SPACE		= BIT(5),
+	IEEE80211_KEY_FLAG_RX_MGMT		= BIT(6),
 };
 
 /**

net/mac80211/wpa.c

@@ -406,7 +406,10 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 
 	if (info->control.hw_key &&
 	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
-	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
+	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
+	    !((info->control.hw_key->flags &
+	       IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
+	      ieee80211_is_mgmt(hdr->frame_control))) {
 		/*
 		 * hwaccel has no need for preallocated room for CCMP
 		 * header or MIC fields