mac80211: move TKIP TX IVs to public part of key struct

Some drivers/devices might want to set the IVs by
themselves (and still let mac80211 generate MMIC).

Specifically, this is needed when the device does
offloading at certain times, and the driver has
to make sure that the IVs of new tx frames (from
the host) are synchronized with IVs that were
potentially used during the offloading.

Similarly to CCMP, move the TX IVs of TKIP keys to the
public part of the key struct, and export a function
to add the IV right into the crypto header.

The public tx_pn field is defined as atomic64, so define
TKIP_PN_TO_IV16/32 helper macros to convert it to iv16/32
when needed.

Since the iv32 used for the p1k cache is taken
directly from the frame, we can safely remove
iv16/32 from being protected by tkip.txlock.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index 9951ef06323e..4aa20cef0859 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -44,13 +44,17 @@ enum ieee80211_internal_tkip_state {
 };
 
 struct tkip_ctx {
-	u32 iv32;	/* current iv32 */
-	u16 iv16;	/* current iv16 */
 	u16 p1k[5];	/* p1k cache */
 	u32 p1k_iv32;	/* iv32 for which p1k computed */
 	enum ieee80211_internal_tkip_state state;
 };
 
+struct tkip_ctx_rx {
+	struct tkip_ctx ctx;
+	u32 iv32;	/* current iv32 */
+	u16 iv16;	/* current iv16 */
+};
+
 struct ieee80211_key {
 	struct ieee80211_local *local;
 	struct ieee80211_sub_if_data *sdata;
@@ -71,7 +75,7 @@ struct ieee80211_key {
 			struct tkip_ctx tx;
 
 			/* last received RSC */
-			struct tkip_ctx rx[IEEE80211_NUM_TIDS];
+			struct tkip_ctx_rx rx[IEEE80211_NUM_TIDS];
 
 			/* number of mic failures */
 			u32 mic_failures;