/*      $NetBSD: apfs.c,v 1.1 2019/12/27 11:15:06 tkusumi Exp $ */
/*
* Copyright (c) 2019 Conrad Meyer <[email protected]>.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: apfs.c,v 1.1 2019/12/27 11:15:06 tkusumi Exp $");

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "fstyp.h"

/*
* This really detects the container format, which might be best supported by
* geom_part or a special GEOM class.
*
* https://developer.apple.com/support/downloads/Apple-File-System-Reference.pdf
*/

#define NX_CKSUM_SZ             8

typedef uint64_t nx_oid_t;

typedef uint64_t nx_xid_t;

struct nx_obj {
       uint8_t         o_cksum[NX_CKSUM_SZ];   /* Fletcher 64 */
       nx_oid_t        o_oid;
       nx_xid_t        o_xid;
       uint32_t        o_type;
       uint32_t        o_subtype;
};

/* nx_obj::o_oid */
#define OID_NX_SUPERBLOCK       1

/* nx_obj::o_type: */
#define OBJECT_TYPE_MASK                0x0000ffff
#define OBJECT_TYPE_NX_SUPERBLOCK       0x00000001
#define OBJECT_TYPE_FLAGS_MASK          0xffff0000
#define OBJ_STORAGETYPE_MASK            0xc0000000
#define OBJECT_TYPE_FLAGS_DEFINED_MASK  0xf8000000
#define OBJ_STORAGE_VIRTUAL             0x00000000
#define OBJ_STORAGE_EPHEMERAL           0x80000000
#define OBJ_STORAGE_PHYSICAL            0x40000000
#define OBJ_NOHEADER                    0x20000000
#define OBJ_ENCRYPTED                   0x10000000
#define OBJ_NONPERSISTENT               0x08000000

struct nx_superblock {
       struct nx_obj   nx_o;
       char            nx_magic[4];
       /* ... other stuff that doesn't matter */
};

int
fstyp_apfs(FILE *fp, char *label, size_t size)
{
       struct nx_superblock *csb;
       int retval;

       retval = 1;
       csb = read_buf(fp, 0, sizeof(*csb));
       if (csb == NULL)
               goto fail;

       /* Ideally, checksum the SB here. */
       if (strncmp(csb->nx_magic, "NXSB", 4) != 0 ||
           csb->nx_o.o_oid != OID_NX_SUPERBLOCK ||
           (csb->nx_o.o_type & OBJECT_TYPE_MASK) != OBJECT_TYPE_NX_SUPERBLOCK)
               goto fail;

       retval = 0;

       /* No label support yet. */

fail:
       free(csb);
       return (retval);
}