#ifndef _NET_ESP_H#define _NET_ESP_H #include <linux/crypto.h>#include <net/xfrm.h>#include <asm/scatterlist.h> #define ESP_NUM_FAST_SG		4 struct esp_data{	struct scatterlist		sgbuf[ESP_NUM_FAST_SG]; 	/* Confidentiality */	struct {		u8			*key;		/* Key */		int			key_len;	/* Key length */		int			padlen;		/* 0..255 */		/* ivlen is offset from enc_data, where encrypted data start.		 * It is logically different of crypto_tfm_alg_ivsize(tfm).		 * We assume that it is either zero (no ivec), or		 * >= crypto_tfm_alg_ivsize(tfm). */		int			ivlen;		int			ivinitted;		u8			*ivec;		/* ivec buffer */		struct crypto_blkcipher	*tfm;		/* crypto handle */	} conf; 	/* Integrity. It is active when icv_full_len != 0 */	struct {		u8			*key;		/* Key */		int			key_len;	/* Length of the key */		u8			*work_icv;		int			icv_full_len;		int			icv_trunc_len;		void			(*icv)(struct esp_data*,		                               struct sk_buff *skb,		                               int offset, int len, u8 *icv);		struct crypto_hash	*tfm;	} auth;}; extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len);extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); static inline int esp_mac_digest(struct esp_data *esp, struct sk_buff *skb,				 int offset, int len){	struct hash_desc desc;	int err; 	desc.tfm = esp->auth.tfm;	desc.flags = 0; 	err = crypto_hash_init(&desc);	if (unlikely(err))		return err;	err = skb_icv_walk(skb, &desc, offset, len, crypto_hash_update);	if (unlikely(err))		return err;	return crypto_hash_final(&desc, esp->auth.work_icv);} #endif