1#ifndef _NET_ESP_H
2#define _NET_ESP_H
3
4#include <linux/crypto.h>
5#include <net/xfrm.h>
6#include <asm/scatterlist.h>
7
8#define ESP_NUM_FAST_SG		4
9
10struct esp_data
11{
12	struct scatterlist		sgbuf[ESP_NUM_FAST_SG];
13
14	/* Confidentiality */
15	struct {
16		u8			*key;		/* Key */
17		int			key_len;	/* Key length */
18		int			padlen;		/* 0..255 */
19		/* ivlen is offset from enc_data, where encrypted data start.
20		 * It is logically different of crypto_tfm_alg_ivsize(tfm).
21		 * We assume that it is either zero (no ivec), or
22		 * >= crypto_tfm_alg_ivsize(tfm). */
23		int			ivlen;
24		int			ivinitted;
25		u8			*ivec;		/* ivec buffer */
26		struct crypto_blkcipher	*tfm;		/* crypto handle */
27	} conf;
28
29	/* Integrity. It is active when icv_full_len != 0 */
30	struct {
31		u8			*key;		/* Key */
32		int			key_len;	/* Length of the key */
33		u8			*work_icv;
34		int			icv_full_len;
35		int			icv_trunc_len;
36		void			(*icv)(struct esp_data*,
37		                               struct sk_buff *skb,
38		                               int offset, int len, u8 *icv);
39		struct crypto_hash	*tfm;
40	} auth;
41};
42
43extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
44
45static inline int esp_mac_digest(struct esp_data *esp, struct sk_buff *skb,
46				 int offset, int len)
47{
48	struct hash_desc desc;
49	int err;
50
51	desc.tfm = esp->auth.tfm;
52	desc.flags = 0;
53
54	err = crypto_hash_init(&desc);
55	if (unlikely(err))
56		return err;
57	err = skb_icv_walk(skb, &desc, offset, len, crypto_hash_update);
58	if (unlikely(err))
59		return err;
60	return crypto_hash_final(&desc, esp->auth.work_icv);
61}
62
63#endif
64