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      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