mac80211: allow driver access to TKIP RX P1K

When the driver wants to pre-program the TKIP
RX phase 1 key, it needs to be able to obtain
it for the peer's TA. Add API to allow it to
generate it.

The generation uses a dummy on-stack context
since it doesn't know the RX queue.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

include/net/mac80211.h

@@ -2612,6 +2612,20 @@ static inline void ieee80211_get_tkip_p1k(struct ieee80211_key_conf *keyconf,
 	ieee80211_get_tkip_p1k_iv(keyconf, iv32, p1k);
 }
 
+/**
+ * ieee80211_get_tkip_rx_p1k - get a TKIP phase 1 key for RX
+ *
+ * This function returns the TKIP phase 1 key for the given IV32
+ * and transmitter address.
+ *
+ * @keyconf: the parameter passed with the set key
+ * @ta: TA that will be used with the key
+ * @iv32: IV32 to get the P1K for
+ * @p1k: a buffer to which the key will be written, as 5 u16 values
+ */
+void ieee80211_get_tkip_rx_p1k(struct ieee80211_key_conf *keyconf,
+			       const u8 *ta, u32 iv32, u16 *p1k);
+
 /**
  * ieee80211_get_tkip_p2k - get a TKIP phase 2 key
  *

net/mac80211/tkip.c

@@ -185,6 +185,17 @@ void ieee80211_get_tkip_p1k_iv(struct ieee80211_key_conf *keyconf,
 }
 EXPORT_SYMBOL(ieee80211_get_tkip_p1k_iv);
 
+void ieee80211_get_tkip_rx_p1k(struct ieee80211_key_conf *keyconf,
+                               const u8 *ta, u32 iv32, u16 *p1k)
+{
+	const u8 *tk = &keyconf->key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
+	struct tkip_ctx ctx;
+
+	tkip_mixing_phase1(tk, &ctx, ta, iv32);
+	memcpy(p1k, ctx.p1k, sizeof(ctx.p1k));
+}
+EXPORT_SYMBOL(ieee80211_get_tkip_rx_p1k);
+
 void ieee80211_get_tkip_p2k(struct ieee80211_key_conf *keyconf,
 			    struct sk_buff *skb, u8 *p2k)
 {