/*      $NetBSD: ip_encap.h,v 1.28 2022/12/07 08:33:02 knakahara Exp $  */
/*      $KAME: ip_encap.h,v 1.7 2000/03/25 07:23:37 sumikawa Exp $      */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _NETINET_IP_ENCAP_H_
#define _NETINET_IP_ENCAP_H_

#ifdef _KERNEL

#include <sys/pslist.h>
#include <sys/psref.h>

struct encapsw {
        union {
                struct encapsw4 {
                        void    (*pr_input)     /* input to protocol (from below) */
                                (struct mbuf *, int, int, void *);
                        void    *(*pr_ctlinput)         /* control input (from below) */
                                (int, const struct sockaddr *, void *, void *);
                } _encapsw4;
                struct encapsw6 {
                        int     (*pr_input)     /* input to protocol (from below) */
                                (struct mbuf **, int *, int, void *);
                        void    *(*pr_ctlinput)         /* control input (from below) */
                                (int, const struct sockaddr *, void *, void *);
                } _encapsw6;
        } encapsw46;
};

#define encapsw4 encapsw46._encapsw4
#define encapsw6 encapsw46._encapsw6

typedef int encap_priofunc_t(struct mbuf *, int, int, void *);

struct encap_key {
        union  {
                struct sockaddr         local_u_sa;
                struct sockaddr_in      local_u_sin;
                struct sockaddr_in6     local_u_sin6;
        }       local_u;
#define local_sa        local_u.local_u_sa
#define local_sin       local_u.local_u_sin
#define local_sin6      local_u.local_u_sin6

        union  {
                struct sockaddr         remote_u_sa;
                struct sockaddr_in      remote_u_sin;
                struct sockaddr_in6     remote_u_sin6;
        }       remote_u;
#define remote_sa       remote_u.remote_u_sa
#define remote_sin      remote_u.remote_u_sin
#define remote_sin6     remote_u.remote_u_sin6

        u_int seq;
};

struct encaptab {
        struct pslist_entry chain;
        int af;
        int proto;                      /* -1: don't care, I'll check myself */
        struct sockaddr *addrpack;      /* malloc'ed, for lookup */
        struct sockaddr *src;           /* my addr */
        struct sockaddr *dst;           /* remote addr */
        encap_priofunc_t *func;
        const struct encapsw *esw;
        void *arg;
        struct encap_key key;
        u_int flag;
        struct psref_target     psref;
};

#define IP_ENCAP_ADDR_ENABLE    __BIT(0)

/* to lookup a pair of address using map */
struct sockaddr_pack {
        u_int8_t sp_len;
        u_int8_t sp_family;     /* not really used */
        /* followed by variable-length data */
};

struct ip_pack4 {
        struct sockaddr_pack p;
        struct sockaddr_in mine;
        struct sockaddr_in yours;
};
struct ip_pack6 {
        struct sockaddr_pack p;
        struct sockaddr_in6 mine;
        struct sockaddr_in6 yours;
};

void    encapinit(void);

void    encap_init(void);
void    encap4_input(struct mbuf *, int, int);
int     encap6_input(struct mbuf **, int *, int);
const struct encaptab *encap_attach_func(int, int,
        encap_priofunc_t *,
        const struct encapsw *, void *);
const struct encaptab *encap_attach_addr(int, int,
        const struct sockaddr *, const struct sockaddr *,
        encap_priofunc_t *, const struct encapsw *, void *);
void    *encap6_ctlinput(int, const struct sockaddr *, void *);
int     encap_detach(const struct encaptab *);

int     encap_lock_enter(void);
void    encap_lock_exit(void);
bool    encap_lock_held(void);

#define ENCAP_PR_WRAP_CTLINPUT(name)                            \
static void *                                                   \
name##_wrapper(int a, const struct sockaddr *b, void *c, void *d) \
{                                                               \
        void *rv;                                               \
        KERNEL_LOCK(1, NULL);                                   \
        rv = name(a, b, c, d);                                  \
        KERNEL_UNLOCK_ONE(NULL);                                \
        return rv;                                              \
}
#endif

#endif /* !_NETINET_IP_ENCAP_H_ */