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/kobj.h>
31 #include <sys/zmod.h>
32
33 #include <contrib/zlib/zlib.h>
34 #include <contrib/zlib/zutil.h>
35
36 struct zchdr {
37 uint_t zch_magic;
38 uint_t zch_size;
39 };
40
41 #define ZCH_MAGIC 0x3cc13cc1
42
43 /*ARGSUSED*/
44 static void *
zfs_zcalloc(void * opaque,uint_t items,uint_t size)45 zfs_zcalloc(void *opaque, uint_t items, uint_t size)
46 {
47 size_t nbytes = sizeof (struct zchdr) + items * size;
48 struct zchdr *z = kobj_zalloc(nbytes, KM_NOWAIT|KM_TMP);
49
50 if (z == NULL)
51 return (NULL);
52
53 z->zch_magic = ZCH_MAGIC;
54 z->zch_size = nbytes;
55
56 return (z + 1);
57 }
58
59 /*ARGSUSED*/
60 static void
zfs_zcfree(void * opaque,void * ptr)61 zfs_zcfree(void *opaque, void *ptr)
62 {
63 struct zchdr *z = ((struct zchdr *)ptr) - 1;
64
65 if (z->zch_magic != ZCH_MAGIC)
66 panic("zcfree region corrupt: hdr=%p ptr=%p", (void *)z, ptr);
67
68 kobj_free(z, z->zch_size);
69 }
70
71 /*
72 * Uncompress the buffer 'src' into the buffer 'dst'. The caller must store
73 * the expected decompressed data size externally so it can be passed in.
74 * The resulting decompressed size is then returned through dstlen. This
75 * function return Z_OK on success, or another error code on failure.
76 */
77 int
z_uncompress(void * dst,size_t * dstlen,const void * src,size_t srclen)78 z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
79 {
80 z_stream zs;
81 int err;
82
83 bzero(&zs, sizeof (zs));
84 zs.next_in = (uchar_t *)src;
85 zs.avail_in = srclen;
86 zs.next_out = dst;
87 zs.avail_out = *dstlen;
88 zs.zalloc = zfs_zcalloc;
89 zs.zfree = zfs_zcfree;
90
91 /*
92 * Call inflateInit2() specifying a window size of DEF_WBITS
93 * with the 6th bit set to indicate that the compression format
94 * type (zlib or gzip) should be automatically detected.
95 */
96 if ((err = inflateInit2(&zs, DEF_WBITS | 0x20)) != Z_OK)
97 return (err);
98
99 if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
100 (void) inflateEnd(&zs);
101 return (err == Z_OK ? Z_BUF_ERROR : err);
102 }
103
104 *dstlen = zs.total_out;
105 return (inflateEnd(&zs));
106 }
107
108 int
z_compress_level(void * dst,size_t * dstlen,const void * src,size_t srclen,int level)109 z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
110 int level)
111 {
112
113 z_stream zs;
114 int err;
115
116 bzero(&zs, sizeof (zs));
117 zs.next_in = (uchar_t *)src;
118 zs.avail_in = srclen;
119 zs.next_out = dst;
120 zs.avail_out = *dstlen;
121 zs.zalloc = zfs_zcalloc;
122 zs.zfree = zfs_zcfree;
123
124 if ((err = deflateInit(&zs, level)) != Z_OK)
125 return (err);
126
127 if ((err = deflate(&zs, Z_FINISH)) != Z_STREAM_END) {
128 (void) deflateEnd(&zs);
129 return (err == Z_OK ? Z_BUF_ERROR : err);
130 }
131
132 *dstlen = zs.total_out;
133 return (deflateEnd(&zs));
134 }
135
136 int
z_compress(void * dst,size_t * dstlen,const void * src,size_t srclen)137 z_compress(void *dst, size_t *dstlen, const void *src, size_t srclen)
138 {
139 return (z_compress_level(dst, dstlen, src, srclen,
140 Z_DEFAULT_COMPRESSION));
141 }
142
143 /*
144 * Convert a zlib error code into a string error message.
145 */
146 const char *
z_strerror(int err)147 z_strerror(int err)
148 {
149 int i = Z_NEED_DICT - err;
150
151 if (i < 0 || i > Z_NEED_DICT - Z_VERSION_ERROR)
152 return ("unknown error");
153
154 return (zError(err));
155 }
156