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*/
37 static void *
38 zfs_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*/
47 static void
48 zfs_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  */
60 int
61 z_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 
91 int
92 z_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 
119 int
120 z_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  */
129 const char *
130 z_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