mac80211: aead api to reduce redundancy

Currently, the aes_ccm.c and aes_gcm.c are almost line by line copy of
each other. This patch reduce code redundancy by moving the code in these
two files to crypto/aead_api.c to make it a higher level aead api. The
file aes_ccm.c and aes_gcm.c are removed and all the functions there are
now implemented in their headers using the newly added aead api.

Signed-off-by: Xiang Gao <qasdfgtyuiop@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/aes_ccm.h b/net/mac80211/aes_ccm.h
index fcd3254..e9b7ca0 100644
--- a/net/mac80211/aes_ccm.h
+++ b/net/mac80211/aes_ccm.h
@@ -10,19 +10,39 @@
 #ifndef AES_CCM_H
 #define AES_CCM_H
 
-#include <linux/crypto.h>
+#include "aead_api.h"
 
 #define CCM_AAD_LEN	32
 
-struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
-						    size_t key_len,
-						    size_t mic_len);
-int ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
-			      u8 *data, size_t data_len, u8 *mic,
-			      size_t mic_len);
-int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
-			      u8 *data, size_t data_len, u8 *mic,
-			      size_t mic_len);
-void ieee80211_aes_key_free(struct crypto_aead *tfm);
+static inline struct crypto_aead *
+ieee80211_aes_key_setup_encrypt(const u8 key[], size_t key_len, size_t mic_len)
+{
+	return aead_key_setup_encrypt("ccm(aes)", key, key_len, mic_len);
+}
+
+static inline int
+ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm,
+			  u8 *b_0, u8 *aad, u8 *data,
+			  size_t data_len, u8 *mic)
+{
+	return aead_encrypt(tfm, b_0, aad + 2,
+			    be16_to_cpup((__be16 *)aad),
+			    data, data_len, mic);
+}
+
+static inline int
+ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm,
+			  u8 *b_0, u8 *aad, u8 *data,
+			  size_t data_len, u8 *mic)
+{
+	return aead_decrypt(tfm, b_0, aad + 2,
+			    be16_to_cpup((__be16 *)aad),
+			    data, data_len, mic);
+}
+
+static inline void ieee80211_aes_key_free(struct crypto_aead *tfm)
+{
+	return aead_key_free(tfm);
+}
 
 #endif /* AES_CCM_H */