/*-
 * Copyright 2013 Alexander Peslyak
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#include <errno.h>
#include <stdlib.h>

#include "crypto_scrypt.h"
#include "runtime.h"

#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
#define MAP_ANON MAP_ANONYMOUS
#endif

void *
alloc_region(escrypt_region_t *region, size_t size)
{
    uint8_t *base, *aligned;
#if defined(MAP_ANON) && defined(HAVE_MMAP)
    if ((base = (uint8_t *) mmap(NULL, size, PROT_READ | PROT_WRITE,
#ifdef MAP_NOCORE
                                 MAP_ANON | MAP_PRIVATE | MAP_NOCORE,
#else
                                 MAP_ANON | MAP_PRIVATE,
#endif
                                 -1, 0)) == MAP_FAILED)
        base = NULL; /* LCOV_EXCL_LINE */
    aligned  = base;
#elif defined(HAVE_POSIX_MEMALIGN)
    if ((errno = posix_memalign((void **) &base, 64, size)) != 0) {
        base = NULL;
    }
    aligned = base;
#else
    base = aligned = NULL;
    if (size + 63 < size)
        errno = ENOMEM;
    else if ((base = (uint8_t *) malloc(size + 63)) != NULL) {
        aligned = base + 63;
        aligned -= (uintptr_t) aligned & 63;
    }
#endif
    region->base    = base;
    region->aligned = aligned;
    region->size    = base ? size : 0;

    return aligned;
}

static inline void
init_region(escrypt_region_t *region)
{
    region->base = region->aligned = NULL;
    region->size                   = 0;
}

int
free_region(escrypt_region_t *region)
{
    if (region->base) {
#if defined(MAP_ANON) && defined(HAVE_MMAP)
        if (munmap(region->base, region->size)) {
            return -1; /* LCOV_EXCL_LINE */
        }
#else
        free(region->base);
#endif
    }
    init_region(region);

    return 0;
}

int
escrypt_init_local(escrypt_local_t *local)
{
    init_region(local);

    return 0;
}

int
escrypt_free_local(escrypt_local_t *local)
{
    return free_region(local);
}
