1  /*
       2   * Copyright (C) 2015 by Philipp Marek <philipp.marek@linbit.com>
       3   *
       4   * This file may be redistributed under the terms of the
       5   * GNU Lesser General Public License.
       6   *
       7   * DRBD is a blocklevel replication solution in the Linux kernel,
       8   * upstream since 2.6.33. (See http://drbd.linbit.com/)
       9   * DRBDmanage is a configuration frontend that assists in
      10   * creating/deleting/modifying DRBD resources across multiple machines
      11   * (a DRBDmanage "cluster"); this file detects its control volume,
      12   * which is replicated (via DRBD 9) on some of the nodes.
      13   */
      14  #include <stdio.h>
      15  #include <stdlib.h>
      16  #include <unistd.h>
      17  #include <string.h>
      18  #include <errno.h>
      19  #include <ctype.h>
      20  #include <inttypes.h>
      21  #include <stddef.h>
      22  
      23  #include "bitops.h"
      24  #include "superblocks.h"
      25  
      26  struct drbdmanage_hdr {
      27  	unsigned char magic[11];
      28  	unsigned char uuid[32];
      29  	unsigned char lf;
      30  } __attribute__ ((packed));
      31  
      32  struct drbdmanage_pers {
      33  	char magic[4];
      34  	uint32_t version_le;
      35  } __attribute__ ((packed));
      36  
      37  
      38  static const char persistence_magic[4] = { '\x1a', '\xdb', '\x98', '\xa2' };
      39  
      40  
      41  static int probe_drbdmanage(blkid_probe pr,
      42  		const struct blkid_idmag *mag __attribute__((__unused__)))
      43  {
      44  	struct drbdmanage_hdr *hdr;
      45  	unsigned char *cp;
      46  	struct drbdmanage_pers *prs;
      47  
      48  	hdr = (struct drbdmanage_hdr*)
      49  		blkid_probe_get_buffer(pr, 0, sizeof(*hdr));
      50  	if (!hdr)
      51  		return errno ? -errno : 1;
      52  
      53  	for(cp=hdr->uuid; cp<&hdr->lf; cp++)
      54  		if (!isxdigit(*cp))
      55  			return 1;
      56  	if (hdr->lf != '\n')
      57  		return 1;
      58  
      59  	if (blkid_probe_strncpy_uuid(pr,
      60  				hdr->uuid, sizeof(hdr->uuid)))
      61  		return errno ? -errno : 1;
      62  
      63  	prs = (struct drbdmanage_pers*)
      64  		blkid_probe_get_buffer(pr, 0x1000, sizeof(*prs));
      65  	if (!prs)
      66  		return errno ? -errno : 1;
      67  
      68  	if (memcmp(prs->magic, persistence_magic, sizeof(prs->magic)) == 0 &&
      69  	    blkid_probe_sprintf_version(pr, "%d", be32_to_cpu(prs->version_le)) != 0)
      70  		return errno ? -errno : 1;
      71  
      72  	return 0;
      73  }
      74  
      75  
      76  const struct blkid_idinfo drbdmanage_idinfo =
      77  {
      78  	.name		= "drbdmanage_control_volume",
      79  	.usage		= BLKID_USAGE_OTHER,
      80  	.probefunc	= probe_drbdmanage,
      81  	.minsz		= 64 * 1024,
      82  	.magics		= {
      83  		{ .magic = "$DRBDmgr=q", .len = 10, .sboff = 0 },
      84  		{ NULL }
      85  	},
      86  };
      87