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ufs.c

/* ufs.c - Unix File System */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2004,2005,2007,2008,2009  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/err.h>
#include <grub/file.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/disk.h>
#include <grub/dl.h>
#include <grub/types.h>

#ifdef MODE_UFS2
#define GRUB_UFS_MAGIC        0x19540119
#else
#define GRUB_UFS_MAGIC        0x11954
#endif

#define GRUB_UFS_INODE        2
#define GRUB_UFS_FILETYPE_DIR 4
#define GRUB_UFS_FILETYPE_LNK 10
#define GRUB_UFS_MAX_SYMLNK_CNT     8

#define GRUB_UFS_DIRBLKS      12
#define GRUB_UFS_INDIRBLKS    3

#define GRUB_UFS_ATTR_TYPE      0160000
#define GRUB_UFS_ATTR_FILE    0100000
#define GRUB_UFS_ATTR_DIR     0040000
#define GRUB_UFS_ATTR_LNK       0120000

#define GRUB_UFS_VOLNAME_LEN  32

/* Calculate in which group the inode can be found.  */
#define UFS_BLKSZ(data) (grub_num_to_cpu32 (data->sblock.bsize, data->be))

#define INODE(data,field) data->inode.  field
#ifdef MODE_UFS2
#define INODE_ENDIAN(data,field,bits1,bits2) grub_num_to_cpu##bits2 (data->inode.field, data->be)
#else
#define INODE_ENDIAN(data,field,bits1,bits2) grub_num_to_cpu##bits1 (data->inode.field, data->be)
#endif

#define INODE_SIZE(data) INODE_ENDIAN (data,size,32,64)
#define INODE_NBLOCKS(data) INODE_ENDIAN (data,nblocks,32,64)

#define INODE_MODE(data) INODE_ENDIAN (data,mode,16,16)
#ifdef MODE_UFS2
#define INODE_BLKSZ 8
#else
#define INODE_BLKSZ 4
#endif
#ifdef MODE_UFS2
#define UFS_INODE_PER_BLOCK 2
#else
#define UFS_INODE_PER_BLOCK 4
#endif
#define INODE_DIRBLOCKS(data,blk) INODE_ENDIAN \
                                   (data,blocks.dir_blocks[blk],32,64)
#define INODE_INDIRBLOCKS(data,blk) INODE_ENDIAN \
                                     (data,blocks.indir_blocks[blk],32,64)

/* The blocks on which the superblock can be found.  */
static int sblocklist[] = { 128, 16, 0, 512, -1 };

00081 struct grub_ufs_sblock
{
  grub_uint8_t unused[16];
  /* The offset of the inodes in the cylinder group.  */
  grub_uint32_t inoblk_offs;

  grub_uint8_t unused2[4];

  /* The start of the cylinder group.  */
  grub_uint32_t cylg_offset;
  grub_uint32_t cylg_mask;

  grub_uint32_t mtime;
  grub_uint8_t unused4[12];

  /* The size of a block in bytes.  */
  grub_int32_t bsize;
  grub_uint8_t unused5[48];

  /* The size of filesystem blocks to disk blocks.  */
  grub_uint32_t log2_blksz;
  grub_uint8_t unused6[40];
  grub_uint32_t uuidhi;
  grub_uint32_t uuidlow;
  grub_uint8_t unused7[32];

  /* Inodes stored per cylinder group.  */
  grub_uint32_t ino_per_group;

  /* The frags per cylinder group.  */
  grub_uint32_t frags_per_group;

  grub_uint8_t unused8[488];

  /* Volume name for UFS2.  */
  grub_uint8_t volume_name[GRUB_UFS_VOLNAME_LEN];
  grub_uint8_t unused9[360];

  grub_uint64_t mtime2;
  grub_uint8_t unused10[292];

  /* Magic value to check if this is really a UFS filesystem.  */
  grub_uint32_t magic;
};

#ifdef MODE_UFS2
/* UFS inode.  */
struct grub_ufs_inode
{
  grub_uint16_t mode;
  grub_uint16_t nlinks;
  grub_uint32_t uid;
  grub_uint32_t gid;
  grub_uint32_t blocksize;
  grub_int64_t size;
  grub_int64_t nblocks;
  grub_uint64_t atime;
  grub_uint64_t mtime;
  grub_uint64_t ctime;
  grub_uint64_t create_time;
  grub_uint32_t atime_sec;
  grub_uint32_t mtime_sec;
  grub_uint32_t ctime_sec;
  grub_uint32_t create_time_sec;
  grub_uint32_t gen;
  grub_uint32_t kernel_flags;
  grub_uint32_t flags;
  grub_uint32_t extsz;
  grub_uint64_t ext[2];
  union
  {
    struct
    {
      grub_uint64_t dir_blocks[GRUB_UFS_DIRBLKS];
      grub_uint64_t indir_blocks[GRUB_UFS_INDIRBLKS];
    } blocks;
    grub_uint8_t symlink[(GRUB_UFS_DIRBLKS + GRUB_UFS_INDIRBLKS) * 8];
  };

  grub_uint8_t unused[24];
} __attribute__ ((packed));
#else
/* UFS inode.  */
00164 struct grub_ufs_inode
{
  grub_uint16_t mode;
  grub_uint16_t nlinks;
  grub_uint16_t uid;
  grub_uint16_t gid;
  grub_int64_t size;
  grub_uint64_t atime;
  grub_uint64_t mtime;
  grub_uint64_t ctime;
  union
  {
    struct
    {
      grub_uint32_t dir_blocks[GRUB_UFS_DIRBLKS];
      grub_uint32_t indir_blocks[GRUB_UFS_INDIRBLKS];
    } blocks;
    grub_uint8_t symlink[(GRUB_UFS_DIRBLKS + GRUB_UFS_INDIRBLKS) * 4];
  };
  grub_uint32_t flags;
  grub_uint32_t nblocks;
  grub_uint32_t gen;
  grub_uint32_t unused;
  grub_uint8_t pad[12];
} __attribute__ ((packed));
#endif

/* Directory entry.  */
00192 struct grub_ufs_dirent
{
  grub_uint32_t ino;
  grub_uint16_t direntlen;
  union
  {
    grub_uint16_t namelen;
    struct
    {
      grub_uint8_t filetype_bsd;
      grub_uint8_t namelen_bsd;
    };
  };
} __attribute__ ((packed));

/* Information about a "mounted" ufs filesystem.  */
00208 struct grub_ufs_data
{
  struct grub_ufs_sblock sblock;
  grub_disk_t disk;
  struct grub_ufs_inode inode;
  int ino;
  int linknest;
  int be;
};

static grub_uint32_t
grub_num_to_cpu32 (grub_uint32_t num, int be)
{
  return (be) ? grub_be_to_cpu32 (num) : grub_le_to_cpu32 (num);
}

static grub_uint16_t
grub_num_to_cpu16 (grub_uint16_t num, int be)
{
  return (be) ? grub_be_to_cpu16 (num) : grub_le_to_cpu16 (num);
}

static grub_uint64_t
grub_num_to_cpu64 (grub_uint64_t num, int be)
{
  return (be) ? grub_be_to_cpu64 (num) : grub_le_to_cpu64 (num);
}

static grub_dl_t my_mod;

/* Forward declaration.  */
static grub_err_t grub_ufs_find_file (struct grub_ufs_data *data,
                              const char *path);


static grub_disk_addr_t
grub_ufs_get_file_block (struct grub_ufs_data *data, unsigned int blk)
{
  int blksz = UFS_BLKSZ (data);
  unsigned int indirsz;
  int log2_blksz;

  /* Direct.  */
  if (blk < GRUB_UFS_DIRBLKS)
    return INODE_DIRBLOCKS (data, blk);

  log2_blksz = grub_num_to_cpu32 (data->sblock.log2_blksz, data->be);

  blk -= GRUB_UFS_DIRBLKS;

  indirsz = blksz / INODE_BLKSZ;
  /* Single indirect block.  */
  if (blk < indirsz)
    {
#ifdef MODE_UFS2
      grub_uint64_t indir[blksz / sizeof (grub_uint64_t)];
#else
      grub_uint32_t indir[blksz / sizeof (grub_uint32_t)];
#endif
      grub_disk_read (data->disk, INODE_INDIRBLOCKS (data, 0) << log2_blksz,
                  0, sizeof (indir), indir);
      return indir[blk];
    }
  blk -= indirsz;

  /* Double indirect block.  */
  if (blk < indirsz * indirsz)
    {
#ifdef MODE_UFS2
      grub_uint64_t indir[blksz / sizeof (grub_uint64_t)];
#else
      grub_uint32_t indir[blksz / sizeof (grub_uint32_t)];
#endif

      grub_disk_read (data->disk, INODE_INDIRBLOCKS (data, 1) << log2_blksz,
                  0, sizeof (indir), indir);
      grub_disk_read (data->disk,
                  (indir [blk / indirsz])
                  << log2_blksz,
                  0, sizeof (indir), indir);

      return indir[blk % indirsz];
    }


  grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
            "ufs does not support triple indirect blocks");
  return 0;
}


/* Read LEN bytes from the file described by DATA starting with byte
   POS.  Return the amount of read bytes in READ.  */
static grub_ssize_t
grub_ufs_read_file (struct grub_ufs_data *data,
                void (*read_hook) (grub_disk_addr_t sector,
                               unsigned offset, unsigned length,
                               void *closure),
                void *closure,
                int pos, grub_size_t len, char *buf)
{
  int blksz = UFS_BLKSZ (data);
  int i;
  int blockcnt;

  /* Adjust len so it we can't read past the end of the file.  */
  if (len + pos > INODE_SIZE (data))
    len = INODE_SIZE (data) - pos;

  blockcnt = (len + pos + blksz - 1) / blksz;

  for (i = pos / blksz; i < blockcnt; i++)
    {
      int blknr;
      int blockoff = pos % blksz;
      int blockend = blksz;

      int skipfirst = 0;

      blknr = grub_ufs_get_file_block (data, i);
      if (grub_errno)
      return -1;

      /* Last block.  */
      if (i == blockcnt - 1)
      {
        blockend = (len + pos) % blksz;

        if (!blockend)
          blockend = blksz;
      }

      /* First block.  */
      if (i == (pos / blksz))
      {
        skipfirst = blockoff;
        blockend -= skipfirst;
      }

      /* XXX: If the block number is 0 this block is not stored on
       disk but is zero filled instead.  */
      if (blknr)
      {
        data->disk->read_hook = read_hook;
        data->disk->closure = closure;
        grub_disk_read (data->disk,
                    blknr << grub_num_to_cpu32 (data->sblock.log2_blksz,
                                          data->be),
                    skipfirst, blockend, buf);
        data->disk->read_hook = 0;
        if (grub_errno)
          return -1;
      }
      else
      grub_memset (buf, blksz - skipfirst, 0);

      buf += blksz - skipfirst;
    }

  return len;
}

/* Read inode INO from the mounted filesystem described by DATA.  This
   inode is used by default now.  */
static grub_err_t
grub_ufs_read_inode (struct grub_ufs_data *data, int ino, char *inode)
{
  struct grub_ufs_sblock *sblock = &data->sblock;

  /* Determine the group the inode is in.  */
  int group = ino / grub_num_to_cpu32 (sblock->ino_per_group, data->be);

  /* Determine the inode within the group.  */
  int grpino = ino % grub_num_to_cpu32 (sblock->ino_per_group, data->be);

  /* The first block of the group.  */
  int grpblk = group * (grub_num_to_cpu32 (sblock->frags_per_group, data->be));

#ifndef MODE_UFS2
  grpblk += grub_num_to_cpu32 (sblock->cylg_offset, data->be)
    * (group & (~grub_num_to_cpu32 (sblock->cylg_mask, data->be)));
#endif

  if (!inode)
    {
      inode = (char *) &data->inode;
      data->ino = ino;
    }

  grub_disk_read (data->disk,
              ((grub_num_to_cpu32 (sblock->inoblk_offs, data->be) + grpblk)
               << grub_num_to_cpu32 (data->sblock.log2_blksz, data->be))
              + grpino / UFS_INODE_PER_BLOCK,
              (grpino % UFS_INODE_PER_BLOCK)
              * sizeof (struct grub_ufs_inode),
              sizeof (struct grub_ufs_inode),
              inode);

  return grub_errno;
}


/* Lookup the symlink the current inode points to.  INO is the inode
   number of the directory the symlink is relative to.  */
static grub_err_t
grub_ufs_lookup_symlink (struct grub_ufs_data *data, int ino)
{
  char symlink[INODE_SIZE (data)];

  if (++data->linknest > GRUB_UFS_MAX_SYMLNK_CNT)
    return grub_error (GRUB_ERR_SYMLINK_LOOP, "too deep nesting of symlinks");

  if (INODE_NBLOCKS (data) == 0)
    grub_strcpy (symlink, (char *) INODE (data, symlink));
  else
    {
      grub_disk_read (data->disk,
                  (INODE_DIRBLOCKS (data, 0)
                   << grub_num_to_cpu32 (data->sblock.log2_blksz, 
                                   data->be)),
                  0, INODE_SIZE (data), symlink);
      symlink[INODE_SIZE (data)] = '\0';
    }

  /* The symlink is an absolute path, go back to the root inode.  */
  if (symlink[0] == '/')
    ino = GRUB_UFS_INODE;

  /* Now load in the old inode.  */
  if (grub_ufs_read_inode (data, ino, 0))
    return grub_errno;

  grub_ufs_find_file (data, symlink);
  if (grub_errno)
    grub_error (grub_errno, "cannot follow symlink `%s'", symlink);

  return grub_errno;
}


/* Find the file with the pathname PATH on the filesystem described by
   DATA.  */
static grub_err_t
grub_ufs_find_file (struct grub_ufs_data *data, const char *path)
{
  char fpath[grub_strlen (path) + 1];
  char *name = fpath;
  char *next;
  unsigned int pos = 0;
  int dirino;

  grub_strcpy (fpath, path);

  /* Skip the first slash.  */
  if (name[0] == '/')
    {
      name++;
      if (!*name)
      return 0;
    }

  /* Extract the actual part from the pathname.  */
  next = grub_strchr (name, '/');
  if (next)
    {
      next[0] = '\0';
      next++;
    }

  do
    {
      struct grub_ufs_dirent dirent;
      int namelen;

      if (grub_strlen (name) == 0)
      return GRUB_ERR_NONE;

      if (grub_ufs_read_file (data, 0, 0, pos, sizeof (dirent),
                        (char *) &dirent) < 0)
      return grub_errno;

#ifdef MODE_UFS2
      namelen = dirent.namelen_bsd;
#else
      namelen = grub_num_to_cpu16 (dirent.namelen, data->be);
#endif
      {
      char filename[namelen + 1];

      if (grub_ufs_read_file (data, 0, 0, pos + sizeof (dirent),
                        namelen, filename) < 0)
        return grub_errno;

      filename[namelen] = '\0';

      if (!grub_strcmp (name, filename))
        {
          dirino = data->ino;
          grub_ufs_read_inode (data, grub_num_to_cpu32 (dirent.ino, 
                                            data->be), 0);

          if ((INODE_MODE(data) & GRUB_UFS_ATTR_TYPE)
            == GRUB_UFS_ATTR_LNK)
            {
            grub_ufs_lookup_symlink (data, dirino);
            if (grub_errno)
              return grub_errno;
            }

          if (!next)
            return 0;

          pos = 0;

          name = next;
          next = grub_strchr (name, '/');
          if (next)
            {
            next[0] = '\0';
            next++;
            }

          if ((INODE_MODE(data) & GRUB_UFS_ATTR_TYPE) != GRUB_UFS_ATTR_DIR)
            return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");

          continue;
        }
      }

      pos += grub_num_to_cpu16 (dirent.direntlen, data->be);
    } while (pos < INODE_SIZE (data));

  grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
  return grub_errno;
}


/* Mount the filesystem on the disk DISK.  */
static struct grub_ufs_data *
grub_ufs_mount (grub_disk_t disk)
{
  struct grub_ufs_data *data;
  int *sblklist = sblocklist;

  data = grub_malloc (sizeof (struct grub_ufs_data));
  if (!data)
    return 0;

  data->disk = disk;
  data->linknest = 0;
  /* Find a UFS sblock.  */
  while (*sblklist != -1)
    {
      grub_disk_read (disk, *sblklist, 0, sizeof (struct grub_ufs_sblock),
                  &data->sblock);
      if (grub_errno)
      goto fail;

      if (grub_le_to_cpu32 (data->sblock.magic) == GRUB_UFS_MAGIC)
      {
        data->be = 0;
        return data;
      }
      else if (grub_be_to_cpu32 (data->sblock.magic) == GRUB_UFS_MAGIC)
      {
        data->be = 1;
        return data;
      }
      sblklist++;
    }

 fail:

  if (grub_errno == GRUB_ERR_NONE || grub_errno == GRUB_ERR_OUT_OF_RANGE)
    {
#ifdef MODE_UFS2
      grub_error (GRUB_ERR_BAD_FS, "not an ufs2 filesystem");
#else
      grub_error (GRUB_ERR_BAD_FS, "not an ufs1 filesystem");
#endif
    }

  grub_free (data);

  return 0;
}


static grub_err_t
grub_ufs_dir (grub_device_t device, const char *path,
             int (*hook) (const char *filename,
                      const struct grub_dirhook_info *info,
                      void *closure),
            void *closure)
{
  struct grub_ufs_data *data;
  struct grub_ufs_sblock *sblock;
  unsigned int pos = 0;

  data = grub_ufs_mount (device->disk);
  if (!data)
    return grub_errno;

  grub_ufs_read_inode (data, GRUB_UFS_INODE, 0);
  if (grub_errno)
    return grub_errno;

  sblock = &data->sblock;

  if (!path || path[0] != '/')
    {
      grub_error (GRUB_ERR_BAD_FILENAME, "bad filename");
      return grub_errno;
    }

  grub_ufs_find_file (data, path);
  if (grub_errno)
    goto fail;

  if ((INODE_MODE (data) & GRUB_UFS_ATTR_TYPE) != GRUB_UFS_ATTR_DIR)
    {
      grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
      goto fail;
    }

  while (pos < INODE_SIZE (data))
    {
      struct grub_ufs_dirent dirent;
      int namelen;

      if (grub_ufs_read_file (data, 0, 0, pos, sizeof (dirent),
                        (char *) &dirent) < 0)
      break;

#ifdef MODE_UFS2
      namelen = dirent.namelen_bsd;
#else
      namelen = grub_num_to_cpu16 (dirent.namelen, data->be);
#endif

      {
      char filename[namelen + 1];
      struct grub_dirhook_info info;
      struct grub_ufs_inode inode;

      grub_memset (&info, 0, sizeof (info));

      if (grub_ufs_read_file (data, 0, 0, pos + sizeof (dirent),
                        namelen, filename) < 0)
        break;

      filename[namelen] = '\0';
      grub_ufs_read_inode (data, dirent.ino, (char *) &inode);

      info.dir = ((grub_num_to_cpu16 (inode.mode, data->be) &
                 GRUB_UFS_ATTR_TYPE)
                == GRUB_UFS_ATTR_DIR);
      info.mtime = grub_num_to_cpu64 (inode.mtime, data->be);
      info.mtimeset = 1;

      if (hook (filename, &info, closure))
        break;
      }

      pos += grub_num_to_cpu16 (dirent.direntlen, data->be);
    }

 fail:
  grub_free (data);

  return grub_errno;
}


/* Open a file named NAME and initialize FILE.  */
static grub_err_t
grub_ufs_open (struct grub_file *file, const char *name)
{
  struct grub_ufs_data *data;
  data = grub_ufs_mount (file->device->disk);
  if (!data)
    return grub_errno;

  grub_ufs_read_inode (data, 2, 0);
  if (grub_errno)
    {
      grub_free (data);
      return grub_errno;
    }

  if (!name || name[0] != '/')
    {
      grub_error (GRUB_ERR_BAD_FILENAME, "bad filename");
      return grub_errno;
    }

  grub_ufs_find_file (data, name);
  if (grub_errno)
    {
      grub_free (data);
      return grub_errno;
    }

  file->data = data;
  file->size = INODE_SIZE (data);

  return GRUB_ERR_NONE;
}


static grub_ssize_t
grub_ufs_read (grub_file_t file, char *buf, grub_size_t len)
{
  struct grub_ufs_data *data =
    (struct grub_ufs_data *) file->data;

  return grub_ufs_read_file (data, file->read_hook, file->closure,
                       file->offset, len, buf);
}


static grub_err_t
grub_ufs_close (grub_file_t file)
{
  grub_free (file->data);

  return GRUB_ERR_NONE;
}


#ifdef MODE_UFS2
static grub_err_t
grub_ufs_label (grub_device_t device, char **label)
{
  struct grub_ufs_data *data = 0;

  grub_dl_ref (my_mod);

  *label = 0;

  data = grub_ufs_mount (device->disk);
  if (data)
    *label = grub_strdup ((char *) data->sblock.volume_name);

  grub_dl_unref (my_mod);

  grub_free (data);

  return grub_errno;
}
#endif

static grub_err_t
grub_ufs_uuid (grub_device_t device, char **uuid)
{
  struct grub_ufs_data *data;
  grub_disk_t disk = device->disk;

  grub_dl_ref (my_mod);

  data = grub_ufs_mount (disk);
  if (data && (data->sblock.uuidhi != 0 || data->sblock.uuidlow != 0))
    *uuid = grub_xasprintf ("%08x%08x",
                     (unsigned) grub_le_to_cpu32 (data->sblock.uuidhi),
                     (unsigned) grub_le_to_cpu32 (data->sblock.uuidlow));
  else
    *uuid = NULL;

  grub_dl_unref (my_mod);

  grub_free (data);

  return grub_errno;
}


/* Get mtime.  */
static grub_err_t
grub_ufs_mtime (grub_device_t device, grub_int32_t *tm)
{
  struct grub_ufs_data *data = 0;

  grub_dl_ref (my_mod);

  data = grub_ufs_mount (device->disk);
  if (!data)
    *tm = 0;
  else
#ifdef MODE_UFS2
    *tm = grub_num_to_cpu64 (data->sblock.mtime2, data->be);
#else
    *tm = grub_num_to_cpu32 (data->sblock.mtime, data->be);
#endif

  grub_dl_unref (my_mod);

  grub_free (data);

  return grub_errno;
}

#ifdef MODE_UFS2
struct grub_fs grub_ufs2_fs =
{
    .name = "ufs2",
    .dir = grub_ufs_dir,
    .open = grub_ufs_open,
    .read = grub_ufs_read,
    .close = grub_ufs_close,
    .label = grub_ufs_label,
    .uuid = grub_ufs_uuid,
    .mtime = grub_ufs_mtime,
    .next = 0
};
#else
struct grub_fs grub_ufs_fs =
{
    .name = "ufs1",
    .dir = grub_ufs_dir,
    .open = grub_ufs_open,
    .read = grub_ufs_read,
    .close = grub_ufs_close,
    .uuid = grub_ufs_uuid,
    .mtime = grub_ufs_mtime,
    .next = 0
};
#endif

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