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 2007 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Portions Copyright 2022 Mikhail Zakharov <zmey20000@yahoo.com>
29 */
30
31 #include <contrib/zlib/zlib.h>
32 #include <contrib/zlib/zutil.h>
33
34 static void *
zfs_zcalloc(void * opaque __unused,uint_t items,uint_t size)35 zfs_zcalloc(void *opaque __unused, uint_t items, uint_t size)
36 {
37
38 return (calloc(items, size));
39 }
40
41 static void
zfs_zcfree(void * opaque __unused,void * ptr)42 zfs_zcfree(void *opaque __unused, void *ptr)
43 {
44 free(ptr);
45 }
46
47 /*
48 * Uncompress the buffer 'src' into the buffer 'dst'. The caller must store
49 * the expected decompressed data size externally so it can be passed in.
50 * The resulting decompressed size is then returned through dstlen. This
51 * function return Z_OK on success, or another error code on failure.
52 */
53 static inline int
z_uncompress(void * dst,size_t * dstlen,const void * src,size_t srclen)54 z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
55 {
56 z_stream zs;
57 int err;
58
59 bzero(&zs, sizeof (zs));
60 zs.next_in = (unsigned char *)src;
61 zs.avail_in = srclen;
62 zs.next_out = dst;
63 zs.avail_out = *dstlen;
64 zs.zalloc = zfs_zcalloc;
65 zs.zfree = zfs_zcfree;
66
67 /*
68 * Call inflateInit2() specifying a window size of DEF_WBITS
69 * with the 6th bit set to indicate that the compression format
70 * type (zlib or gzip) should be automatically detected.
71 */
72 if ((err = inflateInit2(&zs, DEF_WBITS | 0x20)) != Z_OK)
73 return (err);
74
75 if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
76 (void) inflateEnd(&zs);
77 return (err == Z_OK ? Z_BUF_ERROR : err);
78 }
79
80 *dstlen = zs.total_out;
81 return (inflateEnd(&zs));
82 }
83
84 static int
gzip_decompress(void * s_start,void * d_start,size_t s_len,size_t d_len,int n __unused)85 gzip_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len,
86 int n __unused)
87 {
88 size_t dstlen = d_len;
89
90 ASSERT(d_len >= s_len);
91
92 if (z_uncompress(d_start, &dstlen, s_start, s_len) != Z_OK)
93 return (-1);
94
95 return (0);
96 }
97