/*      $OpenBSD: ip_ipsp.h,v 1.119 2002/03/14 01:27:11 millert Exp $   */
/*-
 * The authors of this code are John Ioannidis (ji@tla.org),
 * Angelos D. Keromytis (kermit@csd.uch.gr),
 * Niels Provos (provos@physnet.uni-hamburg.de) and
 * Niklas Hallqvist (niklas@appli.se).
 *
 * The original version of this code was written by John Ioannidis
 * for BSD/OS in Athens, Greece, in November 1995.
 *
 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
 * by Angelos D. Keromytis.
 *
 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
 * and Niels Provos.
 *
 * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist.
 *
 * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
 * Angelos D. Keromytis and Niels Provos.
 * Copyright (c) 1999 Niklas Hallqvist.
 * Copyright (c) 2001, Angelos D. Keromytis.
 *
 * Permission to use, copy, and modify this software with or without fee
 * is hereby granted, provided that this entire notice is included in
 * all copies of any software which is or includes a copy or
 * modification of this software.
 * You may use this code under the GNU public license if you so wish. Please
 * contribute changes back to the authors under this freer than GPL license
 * so that we may further the use of strong encryption without limitations to
 * all.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 */

#ifndef _NETIPSEC_XFORM_H_
#define _NETIPSEC_XFORM_H_

#include <sys/types.h>
#include <sys/queue.h>
#include <netinet/in.h>
#include <opencrypto/xform.h>

#define AH_HMAC_HASHLEN         12      /* 96 bits of authenticator */
#define AH_HMAC_MAXHASHLEN      (SHA2_512_HASH_LEN/2)   /* Keep this updated */
#define AH_HMAC_INITIAL_RPL     1       /* replay counter initial value */

#ifdef _KERNEL
struct secpolicy;
struct secasvar;

/*
 * Packet tag assigned on completion of IPsec processing; used
 * to speedup security policy checking for INBOUND packets.
 */
struct xform_history {
        union sockaddr_union    dst;            /* destination address */
        uint32_t                spi;            /* Security Parameters Index */
        uint8_t                 proto;          /* IPPROTO_ESP or IPPROTO_AH */
        uint8_t                 mode;           /* transport or tunnel */
};

/*
 * Opaque data structure hung off a crypto operation descriptor.
 */
struct xform_data {
        struct secpolicy        *sp;            /* security policy */
        struct secasvar         *sav;           /* related SA */
        crypto_session_t        cryptoid;       /* used crypto session */
        u_int                   idx;            /* IPsec request index */
        int                     protoff;        /* current protocol offset */
        int                     skip;           /* data offset */
        uint8_t                 nxt;            /* next protocol, e.g. IPV4 */
        struct vnet             *vnet;
};

#define XF_IP4          1       /* unused */
#define XF_AH           2       /* AH */
#define XF_ESP          3       /* ESP */
#define XF_TCPSIGNATURE 5       /* TCP MD5 Signature option, RFC 2358 */
#define XF_IPCOMP       6       /* IPCOMP */

struct xformsw {
        u_short                 xf_type;        /* xform ID */
        const char              *xf_name;       /* human-readable name */
        int     (*xf_init)(struct secasvar*, struct xformsw*);  /* setup */
        void    (*xf_cleanup)(struct secasvar*);                /* cleanup */
        int     (*xf_input)(struct mbuf*, struct secasvar*,     /* input */
                        int, int);
        int     (*xf_output)(struct mbuf*,                      /* output */
            struct secpolicy *, struct secasvar *, u_int, int, int);

        volatile u_int          xf_cntr;
        LIST_ENTRY(xformsw)     chain;
};

const struct enc_xform * enc_algorithm_lookup(int);
const struct auth_hash * auth_algorithm_lookup(int);
const struct comp_algo * comp_algorithm_lookup(int);

void xform_attach(void *);
void xform_detach(void *);
int xform_init(struct secasvar *, u_short);

struct crypto_session_params;
/* XF_AH */
int xform_ah_authsize(const struct auth_hash *);
int ah_init0(struct secasvar *, struct xformsw *,
    struct crypto_session_params *);
extern size_t ah_hdrsiz(struct secasvar *);

/* XF_ESP */
extern size_t esp_hdrsiz(struct secasvar *sav);

#endif /* _KERNEL */
#endif /* _NETIPSEC_XFORM_H_ */