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