/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2012-2013 The FreeBSD Foundation
 * Copyright (c) 2015-2017 Mariusz Zaborski <oshogbo@FreeBSD.org>
 * All rights reserved.
 *
 * This software was developed by Pawel Jakub Dawidek under sponsorship from
 * the FreeBSD Foundation.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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 _LIBCASPER_H_
#define _LIBCASPER_H_

#ifdef HAVE_CASPER
#define WITH_CASPER
#endif

#include <sys/types.h>
#include <sys/nv.h>

#include <stdlib.h>
#include <unistd.h>

#define CASPER_NO_UNIQ  0x00000001

#ifndef _NVLIST_T_DECLARED
#define _NVLIST_T_DECLARED
struct nvlist;

typedef struct nvlist nvlist_t;
#endif

#ifndef _CAP_CHANNEL_T_DECLARED
#define _CAP_CHANNEL_T_DECLARED
#ifdef WITH_CASPER
struct cap_channel;

typedef struct cap_channel cap_channel_t;
#define CASPER_SUPPORT  (1)
#else
struct cap_channel {
        int cch_fd;
        int cch_flags;
};
typedef struct cap_channel cap_channel_t;
#define CASPER_SUPPORT  (0)
#endif /* ! WITH_CASPER */
#endif /* ! _CAP_CHANNEL_T_DECLARED */

__BEGIN_DECLS

#ifdef WITH_CASPER
int cap_channel_flags(const cap_channel_t *chan);
#else
static inline int
cap_channel_flags(const cap_channel_t *chan)
{

        return (chan->cch_flags);
}
#endif

static inline int
channel_nvlist_flags(const cap_channel_t *chan)
{
        int flags;

        flags = 0;
        if ((cap_channel_flags(chan) & CASPER_NO_UNIQ) != 0)
                flags |= NV_FLAG_NO_UNIQUE;

        return (flags);
}

/*
 * The functions opens unrestricted communication channel to Casper.
 */
#ifdef WITH_CASPER
cap_channel_t *cap_init(void);
#else
static inline cap_channel_t *
cap_init(void)
{
        cap_channel_t *chan;

        chan = (cap_channel_t *)malloc(sizeof(*chan));
        if (chan != NULL) {
                chan->cch_fd = -1;
        }
        return (chan);
}
#endif

/*
 * The functions to communicate with service.
 */
#ifdef WITH_CASPER
cap_channel_t   *cap_service_open(const cap_channel_t *chan, const char *name);
int              cap_service_limit(const cap_channel_t *chan,
                    const char * const *names, size_t nnames);
#else
static inline cap_channel_t *
cap_service_open(const cap_channel_t *chan __unused,
    const char *name __unused)
{

        return (cap_init());
}

static inline int
cap_service_limit(const cap_channel_t *chan __unused,
    const char * const *names __unused, size_t nnames __unused)
{

        return (0);
}
#endif

/*
 * The function creates cap_channel_t based on the given socket.
 */
#ifdef WITH_CASPER
cap_channel_t *cap_wrap(int sock, int flags);
#else
static inline cap_channel_t *
cap_wrap(int sock, int flags)
{
        cap_channel_t *chan;

        chan = cap_init();
        if (chan != NULL) {
                chan->cch_fd = sock;
                chan->cch_flags = flags;
        }
        return (chan);
}
#endif

/*
 * The function returns communication socket and frees cap_channel_t.
 */
#ifdef WITH_CASPER
int     cap_unwrap(cap_channel_t *chan, int *flags);
#else
static inline int
cap_unwrap(cap_channel_t *chan)
{
        int fd;

        fd = chan->cch_fd;
        free(chan);
        return (fd);
}
#endif

/*
 * The function clones the given capability.
 */
#ifdef WITH_CASPER
cap_channel_t *cap_clone(const cap_channel_t *chan);
#else
static inline cap_channel_t *
cap_clone(const cap_channel_t *chan)
{
        cap_channel_t *newchan;

        newchan = cap_init();
        if (newchan == NULL) {
                return (NULL);
        }

        if (chan->cch_fd == -1) {
                newchan->cch_fd = -1;
        } else {
                newchan->cch_fd = dup(chan->cch_fd);
                if (newchan->cch_fd < 0) {
                        free(newchan);
                        newchan = NULL;
                }
        }
        newchan->cch_flags = chan->cch_flags;

        return (newchan);
}
#endif

/*
 * The function closes the given capability.
 */
#ifdef WITH_CASPER
void    cap_close(cap_channel_t *chan);
#else
static inline void
cap_close(cap_channel_t *chan)
{

        if (chan->cch_fd >= 0) {
                close(chan->cch_fd);
        }
        free(chan);
}
#endif

/*
 * The function returns socket descriptor associated with the given
 * cap_channel_t for use with select(2)/kqueue(2)/etc.
 */
#ifdef WITH_CASPER
int     cap_sock(const cap_channel_t *chan);
#else
#define cap_sock(chan)  (chan->cch_fd)
#endif

/*
 * The function limits the given capability.
 * It always destroys 'limits' on return.
 */
#ifdef WITH_CASPER
int     cap_limit_set(const cap_channel_t *chan, nvlist_t *limits);
#else
static inline int
cap_limit_set(const cap_channel_t *chan __unused,
    nvlist_t *limits __unused)
{

        return (0);
}
#endif

/*
 * The function returns current limits of the given capability.
 */
#ifdef WITH_CASPER
int     cap_limit_get(const cap_channel_t *chan, nvlist_t **limitsp);
#else
static inline int
cap_limit_get(const cap_channel_t *chan __unused, nvlist_t **limitsp)
{

        *limitsp = nvlist_create(channel_nvlist_flags(chan));
        return (0);
}
#endif

/*
 * Function sends nvlist over the given capability.
 */
#ifdef WITH_CASPER
int     cap_send_nvlist(const cap_channel_t *chan, const nvlist_t *nvl);
#else
#define cap_send_nvlist(chan, nvl)      (0)
#endif

/*
 * Function receives nvlist over the given capability.
 */
#ifdef WITH_CASPER
nvlist_t *cap_recv_nvlist(const cap_channel_t *chan);
#else
#define cap_recv_nvlist(chan)           (nvlist_create(chan->cch_flags))
#endif

/*
 * Function sends the given nvlist, destroys it and receives new nvlist in
 * response over the given capability.
 */
#ifdef WITH_CASPER
nvlist_t *cap_xfer_nvlist(const cap_channel_t *chan, nvlist_t *nvl);
#else
static inline nvlist_t *
cap_xfer_nvlist(const cap_channel_t *chan, nvlist_t *nvl)
{

        nvlist_destroy(nvl);
        return (nvlist_create(channel_nvlist_flags(chan)));
}
#endif

__END_DECLS

#endif  /* !_LIBCASPER_H_ */