summaryrefslogtreecommitdiffstats
path: root/grub-core/commands/hexdump.c
blob: eaa12465bb381c5de0475175289e3e6c0e0bea7e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/* hexdump.c - command to dump the contents of a file or memory */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2007,2008,2009  Free Software Foundation, Inc.
 *
 *  GRUB is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <grub/dl.h>
#include <grub/file.h>
#include <grub/disk.h>
#include <grub/misc.h>
#include <grub/lib/hexdump.h>
#include <grub/extcmd.h>
#include <grub/i18n.h>

GRUB_MOD_LICENSE ("GPLv3+");

static const struct grub_arg_option options[] = {
  {"skip", 's', 0, N_("Skip offset bytes from the beginning of file."), 0,
   ARG_TYPE_INT},
  {"length", 'n', 0, N_("Read only LENGTH bytes."), 0, ARG_TYPE_INT},
  {0, 0, 0, 0, 0, 0}
};

static grub_err_t
grub_cmd_hexdump (grub_extcmd_context_t ctxt, int argc, char **args)
{
  struct grub_arg_list *state = ctxt->state;
  char buf[GRUB_DISK_SECTOR_SIZE * 4];
  grub_ssize_t size, length;
  grub_disk_addr_t skip;
  int namelen;

  if (argc != 1)
    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));

  namelen = grub_strlen (args[0]);
  skip = (state[0].set) ? grub_strtoull (state[0].arg, 0, 0) : 0;
  length = (state[1].set) ? grub_strtoul (state[1].arg, 0, 0) : 256;

  if (!grub_strcmp (args[0], "(mem)"))
    hexdump (skip, (char *) (grub_addr_t) skip, length);
  else if ((args[0][0] == '(') && (args[0][namelen - 1] == ')'))
    {
      grub_disk_t disk;
      grub_disk_addr_t sector;
      grub_size_t ofs;

      args[0][namelen - 1] = 0;
      disk = grub_disk_open (&args[0][1]);
      if (! disk)
        return 0;

      sector = (skip >> (GRUB_DISK_SECTOR_BITS + 2)) * 4;
      ofs = skip & (GRUB_DISK_SECTOR_SIZE * 4 - 1);
      while (length)
        {
          grub_size_t len;

          len = length;
          if (len > sizeof (buf))
            len = sizeof (buf);

          if (grub_disk_read (disk, sector, ofs, len, buf))
            break;

          hexdump (skip, buf, len);

          ofs = 0;
          skip += len;
          length -= len;
          sector += 4;
        }

      grub_disk_close (disk);
    }
  else
    {
      grub_file_t file;

      file = grub_file_open (args[0], GRUB_FILE_TYPE_HEXCAT);
      if (! file)
	return 0;

      file->offset = skip;

      while ((size = grub_file_read (file, buf, sizeof (buf))) > 0)
	{
	  unsigned long len;

	  len = ((length) && (size > length)) ? length : size;
	  hexdump (skip, buf, len);
	  skip += len;
	  if (length)
	    {
	      length -= len;
	      if (!length)
		break;
	    }
	}

      grub_file_close (file);
    }

  return 0;
}

static grub_extcmd_t cmd;

GRUB_MOD_INIT (hexdump)
{
  cmd = grub_register_extcmd ("hexdump", grub_cmd_hexdump, 0,
			      N_("[OPTIONS] FILE_OR_DEVICE"),
			      N_("Show raw contents of a file or memory."),
			      options);
}

GRUB_MOD_FINI (hexdump)
{
  grub_unregister_extcmd (cmd);
}