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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 2007 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     28 
     29 #include <sys/modctl.h>
     30 #include <sys/zmod.h>
     31 
     32 #include "zlib.h"
     33 
     34 /*
     35  * Uncompress the buffer 'src' into the buffer 'dst'.  The caller must store
     36  * the expected decompressed data size externally so it can be passed in.
     37  * The resulting decompressed size is then returned through dstlen.  This
     38  * function return Z_OK on success, or another error code on failure.
     39  */
     40 int
     41 z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
     42 {
     43 	z_stream zs;
     44 	int err;
     45 
     46 	bzero(&zs, sizeof (zs));
     47 	zs.next_in = (uchar_t *)src;
     48 	zs.avail_in = srclen;
     49 	zs.next_out = dst;
     50 	zs.avail_out = *dstlen;
     51 
     52 	if ((err = inflateInit(&zs)) != Z_OK)
     53 		return (err);
     54 
     55 	if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
     56 		(void) inflateEnd(&zs);
     57 		return (err == Z_OK ? Z_BUF_ERROR : err);
     58 	}
     59 
     60 	*dstlen = zs.total_out;
     61 	return (inflateEnd(&zs));
     62 }
     63 
     64 int
     65 z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
     66     int level)
     67 {
     68 
     69 	z_stream zs;
     70 	int err;
     71 
     72 	bzero(&zs, sizeof (zs));
     73 	zs.next_in = (uchar_t *)src;
     74 	zs.avail_in = srclen;
     75 	zs.next_out = dst;
     76 	zs.avail_out = *dstlen;
     77 
     78 	if ((err = deflateInit(&zs, level)) != Z_OK)
     79 		return (err);
     80 
     81 	if ((err = deflate(&zs, Z_FINISH)) != Z_STREAM_END) {
     82 		(void) deflateEnd(&zs);
     83 		return (err == Z_OK ? Z_BUF_ERROR : err);
     84 	}
     85 
     86 	*dstlen = zs.total_out;
     87 	return (deflateEnd(&zs));
     88 }
     89 
     90 int
     91 z_compress(void *dst, size_t *dstlen, const void *src, size_t srclen)
     92 {
     93 	return (z_compress_level(dst, dstlen, src, srclen,
     94 	    Z_DEFAULT_COMPRESSION));
     95 }
     96 
     97 /*
     98  * Convert a zlib error code into a string error message.
     99  */
    100 const char *
    101 z_strerror(int err)
    102 {
    103 	int i = Z_NEED_DICT - err;
    104 
    105 	if (i < 0 || i > Z_NEED_DICT - Z_VERSION_ERROR)
    106 		return ("unknown error");
    107 
    108 	return (zError(err));
    109 }
    110