arch/all-pc/boot/grub2-aros/grub-core/fs/zfs/zfs_lzjb.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 1999,2000,2001,2002,2003,2004,2009  Free Software Foundation, Inc.
   4  *  Copyright 2007 Sun Microsystems, Inc.
   5  *
   6  *  GRUB is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/err.h>
  21 #include <grub/file.h>
  22 #include <grub/mm.h>
  23 #include <grub/misc.h>
  24 #include <grub/disk.h>
  25 #include <grub/dl.h>
  26 #include <grub/types.h>
  27 #include <grub/zfs/zfs.h>
  28 #include <grub/zfs/zio.h>
  29 #include <grub/zfs/dnode.h>
  30 #include <grub/zfs/uberblock_impl.h>
  31 #include <grub/zfs/vdev_impl.h>
  32 #include <grub/zfs/zio_checksum.h>
  33 #include <grub/zfs/zap_impl.h>
  34 #include <grub/zfs/zap_leaf.h>
  35 #include <grub/zfs/zfs_znode.h>
  36 #include <grub/zfs/dmu.h>
  37 #include <grub/zfs/dmu_objset.h>
  38 #include <grub/zfs/dsl_dir.h>
  39 #include <grub/zfs/dsl_dataset.h>
  40
  41 #define MATCH_BITS      6
  42 #define MATCH_MIN       3
  43 #define OFFSET_MASK     ((1 << (16 - MATCH_BITS)) - 1)
  44
  45 /*
  46  * Decompression Entry - lzjb
  47  */
  48 #ifndef NBBY
  49 #define NBBY    8
  50 #endif
  51
  52 grub_err_t
  53 lzjb_decompress (void *s_start, void *d_start, grub_size_t s_len,
  54                  grub_size_t d_len);
  55
  56 grub_err_t
  57 lzjb_decompress (void *s_start, void *d_start, grub_size_t s_len,
  58                  grub_size_t d_len)
  59 {
  60   grub_uint8_t *src = s_start;
  61   grub_uint8_t *dst = d_start;
  62   grub_uint8_t *d_end = (grub_uint8_t *) d_start + d_len;
  63   grub_uint8_t *s_end = (grub_uint8_t *) s_start + s_len;
  64   grub_uint8_t *cpy, copymap = 0;
  65   int copymask = 1 << (NBBY - 1);
  66
  67   while (dst < d_end && src < s_end)
  68     {
  69       if ((copymask <<= 1) == (1 << NBBY))
  70         {
  71           copymask = 1;
  72           copymap = *src++;
  73         }
  74       if (src >= s_end)
  75         return grub_error (GRUB_ERR_BAD_FS, "lzjb decompression failed");
  76       if (copymap & copymask)
  77         {
  78           int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
  79           int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
  80           src += 2;
  81           cpy = dst - offset;
  82           if (src > s_end || cpy < (grub_uint8_t *) d_start)
  83             return grub_error (GRUB_ERR_BAD_FS, "lzjb decompression failed");
  84           while (--mlen >= 0 && dst < d_end)
  85             *dst++ = *cpy++;
  86         }
  87       else
  88         *dst++ = *src++;
  89     }
  90   if (dst < d_end)
  91     return grub_error (GRUB_ERR_BAD_FS, "lzjb decompression failed");
  92   return GRUB_ERR_NONE;
  93 }