xref: /freebsd/usr.sbin/fstyp/apfs.c (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
1 /*
2  * Copyright (c) 2019 Conrad Meyer <cem@FreeBSD.org>.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <assert.h>
30 #include <err.h>
31 #include <errno.h>
32 #include <stdbool.h>
33 #include <stdint.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include "fstyp.h"
39 
40 /*
41  * This really detects the container format, which might be best supported by
42  * geom_part or a special GEOM class.
43  *
44  * https://developer.apple.com/support/downloads/Apple-File-System-Reference.pdf
45  */
46 
47 #define	NX_CKSUM_SZ		8
48 
49 typedef uint64_t nx_oid_t;
50 
51 typedef uint64_t nx_xid_t;
52 
53 struct nx_obj {
54 	uint8_t		o_cksum[NX_CKSUM_SZ];	/* Fletcher 64 */
55 	nx_oid_t	o_oid;
56 	nx_xid_t	o_xid;
57 	uint32_t	o_type;
58 	uint32_t	o_subtype;
59 };
60 
61 /* nx_obj::o_oid */
62 #define	OID_NX_SUPERBLOCK	1
63 
64 /* nx_obj::o_type: */
65 #define	OBJECT_TYPE_MASK		0x0000ffff
66 #define	OBJECT_TYPE_NX_SUPERBLOCK	0x00000001
67 #define	OBJECT_TYPE_FLAGS_MASK		0xffff0000
68 #define	OBJ_STORAGETYPE_MASK		0xc0000000
69 #define	OBJECT_TYPE_FLAGS_DEFINED_MASK	0xf8000000
70 #define	OBJ_STORAGE_VIRTUAL		0x00000000
71 #define	OBJ_STORAGE_EPHEMERAL		0x80000000
72 #define	OBJ_STORAGE_PHYSICAL		0x40000000
73 #define	OBJ_NOHEADER			0x20000000
74 #define	OBJ_ENCRYPTED			0x10000000
75 #define	OBJ_NONPERSISTENT		0x08000000
76 
77 struct nx_superblock {
78 	struct nx_obj	nx_o;
79 	char		nx_magic[4];
80 	/* ... other stuff that doesn't matter */
81 };
82 
83 int
84 fstyp_apfs(FILE *fp, char *label, size_t size)
85 {
86 	struct nx_superblock *csb;
87 	int retval;
88 
89 	retval = 1;
90 	csb = read_buf(fp, 0, sizeof(*csb));
91 	if (csb == NULL)
92 		goto fail;
93 
94 	/* Ideally, checksum the SB here. */
95 	if (strncmp(csb->nx_magic, "NXSB", 4) != 0 ||
96 	    csb->nx_o.o_oid != OID_NX_SUPERBLOCK ||
97 	    (csb->nx_o.o_type & OBJECT_TYPE_MASK) != OBJECT_TYPE_NX_SUPERBLOCK)
98 		goto fail;
99 
100 	retval = 0;
101 
102 	/* No label support yet. */
103 	(void)size;
104 	(void)label;
105 
106 fail:
107 	free(csb);
108 	return (retval);
109 }
110