common/zmod/zmod.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/modctl.h>
#include <sys/zmod.h>

#include "zlib.h"
#include "zutil.h"

/*
 * Uncompress the buffer 'src' into the buffer 'dst'.  The caller must store
 * the expected decompressed data size externally so it can be passed in.
 * The resulting decompressed size is then returned through dstlen.  This
 * function return Z_OK on success, or another error code on failure.
 */
int
z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
{
    z_stream zs;
    int err;

    bzero(&zs, sizeof (zs));
    zs.next_in = (uchar_t *)src;
    zs.avail_in = srclen;
    zs.next_out = dst;
    zs.avail_out = *dstlen;

    /*
     * Call inflateInit2() specifying a window size of DEF_WBITS
     * with the 6th bit set to indicate that the compression format
     * type (zlib or gzip) should be automatically detected.
     */
    if ((err = inflateInit2(&zs, DEF_WBITS | 0x20)) != Z_OK)
        return (err);

    if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
        (void) inflateEnd(&zs);
        return (err == Z_OK ? Z_BUF_ERROR : err);
    }

    *dstlen = zs.total_out;
    return (inflateEnd(&zs));
}

int
z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
    int level)
{

    z_stream zs;
    int err;

    bzero(&zs, sizeof (zs));
    zs.next_in = (uchar_t *)src;
    zs.avail_in = srclen;
    zs.next_out = dst;
    zs.avail_out = *dstlen;

    if ((err = deflateInit(&zs, level)) != Z_OK)
        return (err);

    if ((err = deflate(&zs, Z_FINISH)) != Z_STREAM_END) {
        (void) deflateEnd(&zs);
        return (err == Z_OK ? Z_BUF_ERROR : err);
    }

    *dstlen = zs.total_out;
    return (deflateEnd(&zs));
}

int
z_compress(void *dst, size_t *dstlen, const void *src, size_t srclen)
{
    return (z_compress_level(dst, dstlen, src, srclen,
        Z_DEFAULT_COMPRESSION));
}

/*
 * Convert a zlib error code into a string error message.
 */
const char *
z_strerror(int err)
{
    int i = Z_NEED_DICT - err;

    if (i < 0 || i > Z_NEED_DICT - Z_VERSION_ERROR)
        return ("unknown error");

    return (zError(err));
}