kernel/zmod/zmod.c

   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 }