root/include/net/ah.h

INCLUDED FROM

DEFINITIONS

1. ah_mac_digest

#ifndef _NET_AH_H
#define _NET_AH_H

#include <linux/crypto.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                      *work_icv;
        int                     icv_full_len;
        int                     icv_trunc_len;

        struct crypto_hash      *tfm;
};

static inline int ah_mac_digest(struct ah_data *ahp, struct sk_buff *skb,
                                u8 *auth_data)
{
        struct hash_desc desc;
        int err;

        desc.tfm = ahp->tfm;
        desc.flags = 0;

        memset(auth_data, 0, ahp->icv_trunc_len);
        err = crypto_hash_init(&desc);
        if (unlikely(err))
                goto out;
        err = skb_icv_walk(skb, &desc, 0, skb->len, crypto_hash_update);
        if (unlikely(err))
                goto out;
        err = crypto_hash_final(&desc, ahp->work_icv);

out:
        return err;
}

struct ip_auth_hdr;

static inline struct ip_auth_hdr *ip_auth_hdr(const struct sk_buff *skb)
{
        return (struct ip_auth_hdr *)skb_transport_header(skb);
}

#endif