/*

 * Copyright (C) 2015 by Philipp Marek <philipp.marek@linbit.com>

 *

 * This file may be redistributed under the terms of the

 * GNU Lesser General Public License.

 *

 * DRBD is a blocklevel replication solution in the Linux kernel,

 * upstream since 2.6.33. (See http://drbd.linbit.com/)

 * DRBDmanage is a configuration frontend that assists in

 * creating/deleting/modifying DRBD resources across multiple machines

 * (a DRBDmanage "cluster"); this file detects its control volume,

 * which is replicated (via DRBD 9) on some of the nodes.

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include <errno.h>

#include <ctype.h>

#include <inttypes.h>

#include <stddef.h>

#include "bitops.h"

#include "superblocks.h"

struct drbdmanage_hdr {

  unsigned char magic[11];

  unsigned char uuid[32];

  unsigned char lf;

} __attribute__ ((packed));

struct drbdmanage_pers {

  char magic[4];

  uint32_t version_le;

} __attribute__ ((packed));

static const char persistence_magic[4] = { '\x1a', '\xdb', '\x98', '\xa2' };

static int probe_drbdmanage(blkid_probe pr,

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

{

  struct drbdmanage_hdr *hdr;

  unsigned char *cp;

  struct drbdmanage_pers *prs;

  hdr = (struct drbdmanage_hdr*)

    blkid_probe_get_buffer(pr, 0, sizeof(*hdr));

  if (!hdr)

    return errno ? -errno : 1;

  for(cp=hdr->uuid; cp<&hdr->lf; cp++)

    if (!isxdigit(*cp))

      return 1;

  if (hdr->lf != '\n')

    return 1;

  if (blkid_probe_strncpy_uuid(pr,

        hdr->uuid, sizeof(hdr->uuid)))

    return errno ? -errno : 1;

  prs = (struct drbdmanage_pers*)

    blkid_probe_get_buffer(pr, 0x1000, sizeof(*prs));

  if (!prs)

    return errno ? -errno : 1;

  if (memcmp(prs->magic, persistence_magic, sizeof(prs->magic)) == 0 &&

      blkid_probe_sprintf_version(pr, "%"PRIu32, be32_to_cpu(prs->version_le)) != 0)

    return errno ? -errno : 1;

  return 0;

}

const struct blkid_idinfo drbdmanage_idinfo =

{

  .name   = "drbdmanage_control_volume",

  .usage    = BLKID_USAGE_OTHER,

  .probefunc  = probe_drbdmanage,

  .minsz    = 64 * 1024,

  .magics   = {

    { .magic = "$DRBDmgr=q", .len = 10, .sboff = 0 },

    { NULL }

  },

};