/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NET_ESP_H
#define _NET_ESP_H

#include <linux/skbuff.h>

struct ip_esp_hdr;
struct xfrm_state;

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

static inline void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
{
        /* Fill padding... */
        if (tfclen) {
                memset(tail, 0, tfclen);
                tail += tfclen;
        }
        do {
                int i;
                for (i = 0; i < plen - 2; i++)
                        tail[i] = i + 1;
        } while (0);
        tail[plen - 2] = plen - 2;
        tail[plen - 1] = proto;
}

struct esp_info {
        struct  ip_esp_hdr *esph;
        __be64  seqno;
        int     tfclen;
        int     tailen;
        int     plen;
        int     clen;
        int     len;
        int     nfrags;
        __u8    proto;
        bool    inplace;
};

int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp_input_done2(struct sk_buff *skb, int err);
int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp6_input_done2(struct sk_buff *skb, int err);
#endif