#ifndef _NET_AH_H#define _NET_AH_H #include <net/xfrm.h> /* This is the maximum truncated ICV length that we know of. */#define MAX_AH_AUTH_LEN	12 struct ah_data{	u8			*key;	int			key_len;	u8			*work_icv;	int			icv_full_len;	int			icv_trunc_len; 	void			(*icv)(struct ah_data*,	                               struct sk_buff *skb, u8 *icv); 	struct crypto_tfm	*tfm;}; static inline voidah_hmac_digest(struct ah_data *ahp, struct sk_buff *skb, u8 *auth_data){	struct crypto_tfm *tfm = ahp->tfm; 	memset(auth_data, 0, ahp->icv_trunc_len);	crypto_hmac_init(tfm, ahp->key, &ahp->key_len);	skb_icv_walk(skb, tfm, 0, skb->len, crypto_hmac_update);	crypto_hmac_final(tfm, ahp->key, &ahp->key_len, ahp->work_icv);	memcpy(auth_data, ahp->work_icv, ahp->icv_trunc_len);} #endif