/*

 * Copyright (C) 1999 by Andries Brouwer

 * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o

 * Copyright (C) 2001 by Andreas Dilger

 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>

 * Copyright (C) 2008 Karel Zak <kzak@redhat.com>

 * Copyright (C) 2013 Eric Sandeen <sandeen@redhat.com>

 * Copyright (C) 2017 Hewlett Packard Enterprise Development LP

 *

 * This file may be redistributed under the terms of the

 * GNU Lesser General Public License.

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include <errno.h>

#include <ctype.h>

#include <stdint.h>

#include "superblocks.h"

struct exfs_super_block {

  uint32_t  sb_magicnum;  /* magic number == EXFS_SB_MAGIC */

  uint32_t  sb_blocksize; /* logical block size, bytes */

  uint64_t  sb_dblocks; /* number of data blocks */

  uint64_t  sb_rblocks; /* number of realtime blocks */

  uint64_t  sb_rextents;  /* number of realtime extents */

  unsigned char sb_uuid[16];  /* file system unique id */

  uint64_t  sb_logstart;  /* starting block of log if internal */

  uint64_t  sb_rootino; /* root inode number */

  uint64_t  sb_rbmino;  /* bitmap inode for realtime extents */

  uint64_t  sb_rsumino; /* summary inode for rt bitmap */

  uint32_t  sb_rextsize;  /* realtime extent size, blocks */

  uint32_t  sb_agblocks;  /* size of an allocation group */

  uint32_t  sb_agcount; /* number of allocation groups */

  uint32_t  sb_rbmblocks; /* number of rt bitmap blocks */

  uint32_t  sb_logblocks; /* number of log blocks */

  uint16_t  sb_versionnum;  /* header version == EXFS_SB_VERSION */

  uint16_t  sb_sectsize;  /* volume sector size, bytes */

  uint16_t  sb_inodesize; /* inode size, bytes */

  uint16_t  sb_inopblock; /* inodes per block */

  char    sb_fname[12]; /* file system name */

  uint8_t   sb_blocklog;  /* log2 of sb_blocksize */

  uint8_t   sb_sectlog; /* log2 of sb_sectsize */

  uint8_t   sb_inodelog;  /* log2 of sb_inodesize */

  uint8_t   sb_inopblog;  /* log2 of sb_inopblock */

  uint8_t   sb_agblklog;  /* log2 of sb_agblocks (rounded up) */

  uint8_t   sb_rextslog;  /* log2 of sb_rextents */

  uint8_t   sb_inprogress;  /* mkfs is in progress, don't mount */

  uint8_t   sb_imax_pct;  /* max % of fs for inode space */

          /* statistics */

  uint64_t  sb_icount;  /* allocated inodes */

  uint64_t  sb_ifree; /* free inodes */

  uint64_t  sb_fdblocks;  /* free data blocks */

  uint64_t  sb_frextents; /* free realtime extents */

  /* this is not all... but enough for libblkid */

} __attribute__((packed));

#define EXFS_MIN_BLOCKSIZE_LOG  9  /* i.e. 512 bytes */

#define EXFS_MAX_BLOCKSIZE_LOG  16  /* i.e. 65536 bytes */

#define EXFS_MIN_BLOCKSIZE  (1 << EXFS_MIN_BLOCKSIZE_LOG)

#define EXFS_MAX_BLOCKSIZE  (1 << EXFS_MAX_BLOCKSIZE_LOG)

#define EXFS_MIN_SECTORSIZE_LOG 9  /* i.e. 512 bytes */

#define EXFS_MAX_SECTORSIZE_LOG 15  /* i.e. 32768 bytes */

#define EXFS_MIN_SECTORSIZE (1 << EXFS_MIN_SECTORSIZE_LOG)

#define EXFS_MAX_SECTORSIZE (1 << EXFS_MAX_SECTORSIZE_LOG)

#define EXFS_DINODE_MIN_LOG 8

#define EXFS_DINODE_MAX_LOG 11

#define EXFS_DINODE_MIN_SIZE  (1 << EXFS_DINODE_MIN_LOG)

#define EXFS_DINODE_MAX_SIZE  (1 << EXFS_DINODE_MAX_LOG)

#define EXFS_MAX_RTEXTSIZE  (1024 * 1024 * 1024)  /* 1GB */

#define EXFS_DFL_RTEXTSIZE  (64 * 1024)   /* 64kB */

#define EXFS_MIN_RTEXTSIZE  (4 * 1024)    /* 4kB */

#define EXFS_MIN_AG_BLOCKS  64

#define EXFS_MAX_DBLOCKS(s) ((uint64_t)(s)->sb_agcount * (s)->sb_agblocks)

#define EXFS_MIN_DBLOCKS(s) ((uint64_t)((s)->sb_agcount - 1) *  \

       (s)->sb_agblocks + EXFS_MIN_AG_BLOCKS)

static void sb_from_disk(const struct exfs_super_block *from,

       struct exfs_super_block *to)

{

  to->sb_magicnum = be32_to_cpu(from->sb_magicnum);

  to->sb_blocksize = be32_to_cpu(from->sb_blocksize);

  to->sb_dblocks = be64_to_cpu(from->sb_dblocks);

  to->sb_rblocks = be64_to_cpu(from->sb_rblocks);

  to->sb_rextents = be64_to_cpu(from->sb_rextents);

  to->sb_logstart = be64_to_cpu(from->sb_logstart);

  to->sb_rootino = be64_to_cpu(from->sb_rootino);

  to->sb_rbmino = be64_to_cpu(from->sb_rbmino);

  to->sb_rsumino = be64_to_cpu(from->sb_rsumino);

  to->sb_rextsize = be32_to_cpu(from->sb_rextsize);

  to->sb_agblocks = be32_to_cpu(from->sb_agblocks);

  to->sb_agcount = be32_to_cpu(from->sb_agcount);

  to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);

  to->sb_logblocks = be32_to_cpu(from->sb_logblocks);

  to->sb_versionnum = be16_to_cpu(from->sb_versionnum);

  to->sb_sectsize = be16_to_cpu(from->sb_sectsize);

  to->sb_inodesize = be16_to_cpu(from->sb_inodesize);

  to->sb_inopblock = be16_to_cpu(from->sb_inopblock);

  to->sb_blocklog = from->sb_blocklog;

  to->sb_sectlog = from->sb_sectlog;

  to->sb_inodelog = from->sb_inodelog;

  to->sb_inopblog = from->sb_inopblog;

  to->sb_agblklog = from->sb_agblklog;

  to->sb_rextslog = from->sb_rextslog;

  to->sb_inprogress = from->sb_inprogress;

  to->sb_imax_pct = from->sb_imax_pct;

  to->sb_icount = be64_to_cpu(from->sb_icount);

  to->sb_ifree = be64_to_cpu(from->sb_ifree);

  to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);

  to->sb_frextents = be64_to_cpu(from->sb_frextents);

}

static int exfs_verify_sb(const struct exfs_super_block *ondisk)

{

  struct exfs_super_block sb, *sbp = &sb;

  /* beXX_to_cpu(), but don't convert UUID and fsname! */

  sb_from_disk(ondisk, sbp);

  /* sanity checks, we don't want to rely on magic string only */

  if (sbp->sb_agcount <= 0          ||

      sbp->sb_sectsize < EXFS_MIN_SECTORSIZE      ||

      sbp->sb_sectsize > EXFS_MAX_SECTORSIZE      ||

      sbp->sb_sectlog < EXFS_MIN_SECTORSIZE_LOG      ||

      sbp->sb_sectlog > EXFS_MAX_SECTORSIZE_LOG      ||

      sbp->sb_sectsize != (1 << sbp->sb_sectlog)      ||

      sbp->sb_blocksize < EXFS_MIN_BLOCKSIZE      ||

      sbp->sb_blocksize > EXFS_MAX_BLOCKSIZE      ||

      sbp->sb_blocklog < EXFS_MIN_BLOCKSIZE_LOG      ||

      sbp->sb_blocklog > EXFS_MAX_BLOCKSIZE_LOG      ||

      sbp->sb_blocksize != (1ULL << sbp->sb_blocklog)    ||

      sbp->sb_inodesize < EXFS_DINODE_MIN_SIZE      ||

      sbp->sb_inodesize > EXFS_DINODE_MAX_SIZE      ||

      sbp->sb_inodelog < EXFS_DINODE_MIN_LOG      ||

      sbp->sb_inodelog > EXFS_DINODE_MAX_LOG      ||

      sbp->sb_inodesize != (1 << sbp->sb_inodelog)    ||

      (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)  ||

      (sbp->sb_rextsize * sbp->sb_blocksize > EXFS_MAX_RTEXTSIZE)  ||

      (sbp->sb_rextsize * sbp->sb_blocksize < EXFS_MIN_RTEXTSIZE)  ||

      (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)  ||

      sbp->sb_dblocks == 0          ||

      sbp->sb_dblocks > EXFS_MAX_DBLOCKS(sbp)     ||

      sbp->sb_dblocks < EXFS_MIN_DBLOCKS(sbp))

    return 0;

  return 1;

}

static int probe_exfs(blkid_probe pr, const struct blkid_idmag *mag)

{

  const struct exfs_super_block *xs;

  xs = blkid_probe_get_sb(pr, mag, struct exfs_super_block);

  if (!xs)

    return errno ? -errno : 1;

  if (!exfs_verify_sb(xs))

    return 1;

  if (*xs->sb_fname != '\0')

    blkid_probe_set_label(pr, (unsigned char *) xs->sb_fname,

        sizeof(xs->sb_fname));

  blkid_probe_set_uuid(pr, xs->sb_uuid);

  blkid_probe_set_fsblocksize(pr, be32_to_cpu(xs->sb_blocksize));

  blkid_probe_set_block_size(pr, be32_to_cpu(xs->sb_blocksize));

  return 0;

}

const struct blkid_idinfo exfs_idinfo =

{

  .name   = "exfs",

  .usage    = BLKID_USAGE_FILESYSTEM,

  .probefunc  = probe_exfs,

  .magics   =

  {

    { .magic = "EXFS", .len = 4 },

    { NULL }

  }

};