xref: /illumos-gate/usr/src/uts/common/zmod/zmod.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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/modctl.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  */
39 int
40 z_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 
68 int
69 z_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 
94 int
95 z_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  */
104 const char *
105 z_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