grub-core/commands/testload.c

/* testload.c - load the same file in multiple ways */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2003,2005,2006,2007,2009,2010  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/mm.h>
#include <grub/err.h>
#include <grub/env.h>
#include <grub/misc.h>
#include <grub/file.h>
#include <grub/disk.h>
#include <grub/term.h>
#include <grub/loader.h>
#include <grub/command.h>
#include <grub/i18n.h>

GRUB_MOD_LICENSE ("GPLv3+");

static grub_err_t
grub_cmd_testload (struct grub_command *cmd __attribute__ ((unused)),
           int argc, char *argv[])
{
  grub_file_t file;
  char *buf;
  grub_size_t size;
  grub_off_t pos;
  auto void NESTED_FUNC_ATTR read_func (grub_disk_addr_t sector, unsigned offset, unsigned len);

  void NESTED_FUNC_ATTR read_func (grub_disk_addr_t sector __attribute__ ((unused)),
          unsigned offset __attribute__ ((unused)),
          unsigned len __attribute__ ((unused)))
    {
      grub_xputs (".");
      grub_refresh ();
    }

  if (argc < 1)
    return grub_error (GRUB_ERR_BAD_ARGUMENT, "no file specified");

  file = grub_file_open (argv[0]);
  if (! file)
    return grub_errno;

  size = grub_file_size (file) & ~(GRUB_DISK_SECTOR_SIZE - 1);
  if (size == 0)
    {
      grub_file_close (file);
      return GRUB_ERR_NONE;
    }

  buf = grub_malloc (size);
  if (! buf)
    goto fail;

  grub_printf ("Reading %s sequentially", argv[0]);
  file->read_hook = read_func;
  if (grub_file_read (file, buf, size) != (grub_ssize_t) size)
    goto fail;
  grub_printf (" Done.\n");

  /* Read sequentially again.  */
  grub_printf ("Reading %s sequentially again", argv[0]);
  grub_file_seek (file, 0);

  for (pos = 0; pos < size; pos += GRUB_DISK_SECTOR_SIZE)
    {
      char sector[GRUB_DISK_SECTOR_SIZE];

      if (grub_file_read (file, sector, GRUB_DISK_SECTOR_SIZE)
      != GRUB_DISK_SECTOR_SIZE)
    goto fail;

      if (grub_memcmp (sector, buf + pos, GRUB_DISK_SECTOR_SIZE) != 0)
    {
      grub_printf ("\nDiffers in %lld\n", (unsigned long long) pos);
      goto fail;
    }
    }
  grub_printf (" Done.\n");

  /* Read backwards and compare.  */
  grub_printf ("Reading %s backwards", argv[0]);
  pos = size;
  while (pos > 0)
    {
      char sector[GRUB_DISK_SECTOR_SIZE];

      pos -= GRUB_DISK_SECTOR_SIZE;

      grub_file_seek (file, pos);

      if (grub_file_read (file, sector, GRUB_DISK_SECTOR_SIZE)
      != GRUB_DISK_SECTOR_SIZE)
    goto fail;

      if (grub_memcmp (sector, buf + pos, GRUB_DISK_SECTOR_SIZE) != 0)
    {
      int i;

      grub_printf ("\nDiffers in %lld\n", (unsigned long long) pos);

      for (i = 0; i < GRUB_DISK_SECTOR_SIZE; i++)
        {
          grub_printf ("%02x ", buf[pos + i]);
          if ((i & 15) == 15)
        grub_printf ("\n");
        }

      if (i)
        grub_refresh ();

      goto fail;
    }
    }
  grub_printf (" Done.\n");

  return GRUB_ERR_NONE;

 fail:

  grub_file_close (file);
  grub_free (buf);

  if (!grub_errno)
    grub_error (GRUB_ERR_IO, "bad read");
  return grub_errno;
}

static grub_command_t cmd;

GRUB_MOD_INIT(testload)
{
  cmd =
    grub_register_command ("testload", grub_cmd_testload,
               N_("FILE"),
               N_("Load the same file in multiple ways."));
}

GRUB_MOD_FINI(testload)
{
  grub_unregister_command (cmd);
}