net/mac80211: move WEP handling to ARC4 library interface

The WEP code in the mac80211 subsystem currently uses the crypto
API to access the arc4 (RC4) cipher, which is overly complicated,
and doesn't really have an upside in this particular case, since
ciphers are always synchronous and therefore always implemented in
software. Given that we have no accelerated software implementations
either, it is much more straightforward to invoke a generic library
interface directly.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

net/mac80211/tkip.c

@@ -222,7 +222,7 @@ EXPORT_SYMBOL(ieee80211_get_tkip_p2k);
  * @payload_len is the length of payload (_not_ including IV/ICV length).
  * @ta is the transmitter addresses.
  */
-int ieee80211_tkip_encrypt_data(struct crypto_cipher *tfm,
+int ieee80211_tkip_encrypt_data(struct arc4_ctx *ctx,
 				struct ieee80211_key *key,
 				struct sk_buff *skb,
 				u8 *payload, size_t payload_len)
@@ -231,7 +231,7 @@ int ieee80211_tkip_encrypt_data(struct crypto_cipher *tfm,
 
 	ieee80211_get_tkip_p2k(&key->conf, skb, rc4key);
 
-	return ieee80211_wep_encrypt_data(tfm, rc4key, 16,
+	return ieee80211_wep_encrypt_data(ctx, rc4key, 16,
 					  payload, payload_len);
 }
 
@@ -239,7 +239,7 @@ int ieee80211_tkip_encrypt_data(struct crypto_cipher *tfm,
  * beginning of the buffer containing IEEE 802.11 header payload, i.e.,
  * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the
  * length of payload, including IV, Ext. IV, MIC, ICV.  */
-int ieee80211_tkip_decrypt_data(struct crypto_cipher *tfm,
+int ieee80211_tkip_decrypt_data(struct arc4_ctx *ctx,
 				struct ieee80211_key *key,
 				u8 *payload, size_t payload_len, u8 *ta,
 				u8 *ra, int only_iv, int queue,
@@ -297,7 +297,7 @@ int ieee80211_tkip_decrypt_data(struct crypto_cipher *tfm,
 
 	tkip_mixing_phase2(tk, &rx_ctx->ctx, iv16, rc4key);
 
-	res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12);
+	res = ieee80211_wep_decrypt_data(ctx, rc4key, 16, pos, payload_len - 12);
  done:
 	if (res == TKIP_DECRYPT_OK) {
 		/*