1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#include <sys/types.h>
28#include <sys/zmod.h>
29
30#include "zlib.h"
31#include "zutil.h"
32
33/*
34 * Uncompress the buffer 'src' into the buffer 'dst'.  The caller must store
35 * the expected decompressed data size externally so it can be passed in.
36 * The resulting decompressed size is then returned through dstlen.  This
37 * function return Z_OK on success, or another error code on failure.
38 */
39int
40z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
41{
42	z_stream zs;
43	int err;
44
45	bzero(&zs, sizeof (zs));
46	zs.next_in = (uchar_t *)src;
47	zs.avail_in = srclen;
48	zs.next_out = dst;
49	zs.avail_out = *dstlen;
50
51	/*
52	 * Call inflateInit2() specifying a window size of DEF_WBITS
53	 * with the 6th bit set to indicate that the compression format
54	 * type (zlib or gzip) should be automatically detected.
55	 */
56	if ((err = inflateInit2(&zs, DEF_WBITS | 0x20)) != Z_OK)
57		return (err);
58
59	if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
60		(void) inflateEnd(&zs);
61		return (err == Z_OK ? Z_BUF_ERROR : err);
62	}
63
64	*dstlen = zs.total_out;
65	return (inflateEnd(&zs));
66}
67
68int
69z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
70    int level)
71{
72
73	z_stream zs;
74	int err;
75
76	bzero(&zs, sizeof (zs));
77	zs.next_in = (uchar_t *)src;
78	zs.avail_in = srclen;
79	zs.next_out = dst;
80	zs.avail_out = *dstlen;
81
82	if ((err = deflateInit(&zs, level)) != Z_OK)
83		return (err);
84
85	if ((err = deflate(&zs, Z_FINISH)) != Z_STREAM_END) {
86		(void) deflateEnd(&zs);
87		return (err == Z_OK ? Z_BUF_ERROR : err);
88	}
89
90	*dstlen = zs.total_out;
91	return (deflateEnd(&zs));
92}
93
94int
95z_compress(void *dst, size_t *dstlen, const void *src, size_t srclen)
96{
97	return (z_compress_level(dst, dstlen, src, srclen,
98	    Z_DEFAULT_COMPRESSION));
99}
100
101/*
102 * Convert a zlib error code into a string error message.
103 */
104const char *
105z_strerror(int err)
106{
107	int i = Z_NEED_DICT - err;
108
109	if (i < 0 || i > Z_NEED_DICT - Z_VERSION_ERROR)
110		return ("unknown error");
111
112	return (zError(err));
113}
114