/*

 * Copyright (C) 2020 Western Digital Corporation or its affiliates.

 *

 * This file may be redistributed under the terms of the

 * GNU Lesser General Public License

 */

#include <stddef.h>

#include <string.h>

#include "superblocks.h"

#include "crc32.h"

#define ZONEFS_MAGIC    "SFOZ" /* 0x5a4f4653 'Z' 'O' 'F' 'S' */

#define ZONEFS_MAGIC_SIZE 4

#define ZONEFS_MAGIC_OFST 0

#define ZONEFS_UUID_SIZE  16

#define ZONEFS_LABEL_SIZE 32

#define ZONEFS_SB_OFST    0

#define ZONEFS_BLOCK_SIZE 4096U

/* All in little-endian */

struct zonefs_super {

  /* Magic number */

  int32_t   s_magic;

  /* Checksum */

  int32_t   s_crc;

  /* Volume label */

  char    s_label[ZONEFS_LABEL_SIZE];

  /* 128-bit uuid */

  uint8_t   s_uuid[ZONEFS_UUID_SIZE];

  /* Features */

  int64_t   s_features;

  /* UID/GID to use for files */

  int32_t   s_uid;

  int32_t   s_gid;

  /* File permissions */

  int32_t   s_perm;

  /* Padding to 4096 bytes */

  uint8_t   s_reserved[4020];

} __attribute__ ((packed));

static int zonefs_verify_csum(blkid_probe pr, const struct zonefs_super *sb)

{

  uint32_t expected = le32_to_cpu(sb->s_crc);

  uint32_t crc = ul_crc32_exclude_offset(

      ~0LL, (unsigned char *) sb, sizeof(*sb),

           offsetof(__typeof__(*sb), s_crc), sizeof(sb->s_crc), 0);

  return blkid_probe_verify_csum(pr, crc, expected);

}

static int probe_zonefs(blkid_probe pr,

    const struct blkid_idmag *mag  __attribute__((__unused__)))

{

  const struct zonefs_super *sb;

  sb = (struct zonefs_super *)

    blkid_probe_get_buffer(pr, ZONEFS_SB_OFST,

               sizeof(struct zonefs_super));

  if (!sb)

    return errno ? -errno : 1;

  if (!zonefs_verify_csum(pr, sb))

    return 1;

  if (sb->s_label[0])

    blkid_probe_set_label(pr, (unsigned char *) sb->s_label,

              sizeof(sb->s_label));

  blkid_probe_set_uuid(pr, sb->s_uuid);

  blkid_probe_set_fsblocksize(pr, ZONEFS_BLOCK_SIZE);

  blkid_probe_set_block_size(pr, ZONEFS_BLOCK_SIZE);

  return 0;

}

const struct blkid_idinfo zonefs_idinfo =

{

  .name           = "zonefs",

  .usage          = BLKID_USAGE_FILESYSTEM,

  .probefunc      = probe_zonefs,

  .magics         =

        {

    {

      .magic = (char *)ZONEFS_MAGIC,

      .len = ZONEFS_MAGIC_SIZE,

      .kboff = ZONEFS_SB_OFST,

      .sboff = ZONEFS_MAGIC_OFST,

    },

    { NULL }

  }

};