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/cmn_err.h>
29#include <sys/systm.h>
30#include <sys/kmem.h>
31#include <sys/zmod.h>
32
33#include <contrib/zlib/zlib.h>
34#include <contrib/zlib/zutil.h>
35
36/*ARGSUSED*/
37static void *
38zfs_zcalloc(void *opaque, uint_t items, uint_t size)
39{
40	void *ptr;
41
42	ptr = malloc((size_t)items * size, M_SOLARIS, M_NOWAIT);
43	return ptr;
44}
45
46/*ARGSUSED*/
47static void
48zfs_zcfree(void *opaque, void *ptr)
49{
50
51	free(ptr, M_SOLARIS);
52}
53
54/*
55 * Uncompress the buffer 'src' into the buffer 'dst'.  The caller must store
56 * the expected decompressed data size externally so it can be passed in.
57 * The resulting decompressed size is then returned through dstlen.  This
58 * function return Z_OK on success, or another error code on failure.
59 */
60int
61z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
62{
63	z_stream zs;
64	int err;
65
66	bzero(&zs, sizeof (zs));
67	zs.next_in = (uchar_t *)src;
68	zs.avail_in = srclen;
69	zs.next_out = dst;
70	zs.avail_out = *dstlen;
71	zs.zalloc = zfs_zcalloc;
72	zs.zfree = zfs_zcfree;
73
74	/*
75	 * Call inflateInit2() specifying a window size of DEF_WBITS
76	 * with the 6th bit set to indicate that the compression format
77	 * type (zlib or gzip) should be automatically detected.
78	 */
79	if ((err = inflateInit2(&zs, DEF_WBITS | 0x20)) != Z_OK)
80		return (err);
81
82	if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
83		(void) inflateEnd(&zs);
84		return (err == Z_OK ? Z_BUF_ERROR : err);
85	}
86
87	*dstlen = zs.total_out;
88	return (inflateEnd(&zs));
89}
90
91int
92z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
93    int level)
94{
95
96	z_stream zs;
97	int err;
98
99	bzero(&zs, sizeof (zs));
100	zs.next_in = (uchar_t *)src;
101	zs.avail_in = srclen;
102	zs.next_out = dst;
103	zs.avail_out = *dstlen;
104	zs.zalloc = zfs_zcalloc;
105	zs.zfree = zfs_zcfree;
106
107	if ((err = deflateInit(&zs, level)) != Z_OK)
108		return (err);
109
110	if ((err = deflate(&zs, Z_FINISH)) != Z_STREAM_END) {
111		(void) deflateEnd(&zs);
112		return (err == Z_OK ? Z_BUF_ERROR : err);
113	}
114
115	*dstlen = zs.total_out;
116	return (deflateEnd(&zs));
117}
118
119int
120z_compress(void *dst, size_t *dstlen, const void *src, size_t srclen)
121{
122	return (z_compress_level(dst, dstlen, src, srclen,
123	    Z_DEFAULT_COMPRESSION));
124}
125
126/*
127 * Convert a zlib error code into a string error message.
128 */
129const char *
130z_strerror(int err)
131{
132	int i = Z_NEED_DICT - err;
133
134	if (i < 0 || i > Z_NEED_DICT - Z_VERSION_ERROR)
135		return ("unknown error");
136
137	return (zError(err));
138}
139