linux/include/net/esp.h
David S. Miller e4bec827fe [IPSEC] esp: Defer output IV initialization to first use.
First of all, if the xfrm_state only gets used for input
packets this entropy is a complete waste.

Secondly, it is often the case that a configuration loads
many rules (perhaps even dynamically) and they don't all
necessarily ever get used.

This get_random_bytes() call was showing up in the profiles
for xfrm_state inserts which is how I noticed this.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22 15:17:35 -07:00

66 lines
1.7 KiB
C

#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