grub-core/kern/partition.c

/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2004,2007  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/misc.h>
#include <grub/mm.h>
#include <grub/partition.h>
#include <grub/disk.h>
#include <grub/i18n.h>

#ifdef GRUB_UTIL
#include <grub/util/misc.h>
#endif

grub_partition_map_t grub_partition_map_list;

/*
 * Checks that disk->partition contains part.  This function assumes that the
 * start of part is relative to the start of disk->partition.  Returns 1 if
 * disk->partition is null.
 */
static int
grub_partition_check_containment (const grub_disk_t disk,
                  const grub_partition_t part)
{
  if (disk->partition == NULL)
    return 1;

  if (part->start + part->len > disk->partition->len)
    {
      char *partname;

      partname = grub_partition_get_name (disk->partition);
      grub_dprintf ("partition", "sub-partition %s%d of (%s,%s) ends after parent.\n",
            part->partmap->name, part->number + 1, disk->name, partname);
#ifdef GRUB_UTIL
      grub_util_warn (_("Discarding improperly nested partition (%s,%s,%s%d)"),
              disk->name, partname, part->partmap->name, part->number + 1);
#endif
      grub_free (partname);

      return 0;
    }

  return 1;
}

static grub_partition_t
grub_partition_map_probe (const grub_partition_map_t partmap,
              grub_disk_t disk, int partnum)
{
  grub_partition_t p = 0;

  auto int find_func (grub_disk_t d, const grub_partition_t partition);

  int find_func (grub_disk_t dsk,
         const grub_partition_t partition)
    {
      if (partnum != partition->number)
    return 0;

      if (!(grub_partition_check_containment (dsk, partition)))
    return 0;

      p = (grub_partition_t) grub_malloc (sizeof (*p));
      if (! p)
    return 1;

      grub_memcpy (p, partition, sizeof (*p));
      return 1;
    }

  partmap->iterate (disk, find_func);
  if (grub_errno)
    goto fail;

  return p;

 fail:
  grub_free (p);
  return 0;
}

grub_partition_t
grub_partition_probe (struct grub_disk *disk, const char *str)
{
  grub_partition_t part = 0;
  grub_partition_t curpart = 0;
  grub_partition_t tail;
  const char *ptr;

  part = tail = disk->partition;

  for (ptr = str; *ptr;)
    {
      grub_partition_map_t partmap;
      int num;
      const char *partname, *partname_end;

      partname = ptr;
      while (*ptr && grub_isalpha (*ptr))
    ptr++;
      partname_end = ptr;
      num = grub_strtoul (ptr, (char **) &ptr, 0) - 1;

      curpart = 0;
      /* Use the first partition map type found.  */
      FOR_PARTITION_MAPS(partmap)
      {
    if (partname_end != partname &&
        (grub_strncmp (partmap->name, partname, partname_end - partname)
         != 0 || partmap->name[partname_end - partname] != 0))
      continue;

    disk->partition = part;
    curpart = grub_partition_map_probe (partmap, disk, num);
    disk->partition = tail;
    if (curpart)
      break;

    if (grub_errno == GRUB_ERR_BAD_PART_TABLE)
      {
        /* Continue to next partition map type.  */
        grub_errno = GRUB_ERR_NONE;
        continue;
      }

    break;
      }

      if (! curpart)
    {
      while (part)
        {
          curpart = part->parent;
          grub_free (part);
          part = curpart;
        }
      return 0;
    }
      curpart->parent = part;
      part = curpart;
      if (! ptr || *ptr != ',')
    break;
      ptr++;
    }

  return part;
}

int
grub_partition_iterate (struct grub_disk *disk,
            int (*hook) (grub_disk_t disk,
                     const grub_partition_t partition))
{
  int ret = 0;

  auto int part_iterate (grub_disk_t dsk, const grub_partition_t p);

  int part_iterate (grub_disk_t dsk,
            const grub_partition_t partition)
    {
      struct grub_partition p = *partition;

      if (!(grub_partition_check_containment (dsk, partition)))
    return 0;

      p.parent = dsk->partition;
      dsk->partition = 0;
      if (hook (dsk, &p))
    {
      ret = 1;
      return 1;
    }
      if (p.start != 0)
    {
      const struct grub_partition_map *partmap;
      dsk->partition = &p;
      FOR_PARTITION_MAPS(partmap)
      {
        grub_err_t err;
        err = partmap->iterate (dsk, part_iterate);
        if (err)
          grub_errno = GRUB_ERR_NONE;
        if (ret)
          break;
      }
    }
      dsk->partition = p.parent;
      return ret;
    }

  {
    const struct grub_partition_map *partmap;
    FOR_PARTITION_MAPS(partmap)
    {
      grub_err_t err;
      err = partmap->iterate (disk, part_iterate);
      if (err)
    grub_errno = GRUB_ERR_NONE;
      if (ret)
    break;
    }
  }

  return ret;
}

char *
grub_partition_get_name (const grub_partition_t partition)
{
  char *out = 0;
  int curlen = 0;
  grub_partition_t part;
  for (part = partition; part; part = part->parent)
    {
      /* Even on 64-bit machines this buffer is enough to hold
     longest number.  */
      char buf[grub_strlen (part->partmap->name) + 25];
      int strl;
      grub_snprintf (buf, sizeof (buf), "%s%d", part->partmap->name,
             part->number + 1);
      strl = grub_strlen (buf);
      if (curlen)
    {
      out = grub_realloc (out, curlen + strl + 2);
      grub_memcpy (out + strl + 1, out, curlen);
      out[curlen + 1 + strl] = 0;
      grub_memcpy (out, buf, strl);
      out[strl] = ',';
      curlen = curlen + 1 + strl;
    }
      else
    {
      curlen = strl;
      out = grub_strdup (buf);
    }
    }
  return out;
}