1/*	$NetBSD: ffs_appleufs.c,v 1.14 2015/02/14 08:07:39 maxv Exp $	*/
2
3/*
4 * Copyright (c) 2002 Darrin B. Jewell
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__KERNEL_RCSID(0, "$NetBSD: ffs_appleufs.c,v 1.14 2015/02/14 08:07:39 maxv Exp $");
30
31#include <sys/param.h>
32#include <sys/time.h>
33#if defined(_KERNEL)
34#include <sys/kernel.h>
35#include <sys/systm.h>
36#include <sys/cprng.h>
37#endif
38
39#include <ufs/ufs/dinode.h>
40#include <ufs/ufs/ufs_bswap.h>
41#include <ufs/ffs/fs.h>
42#include <ufs/ffs/ffs_extern.h>
43
44#if !defined(_KERNEL) && !defined(STANDALONE)
45#include <stddef.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <string.h>
49#include <errno.h>
50#include <assert.h>
51#define KASSERT(x) assert(x)
52#endif
53
54/*
55 * This is the same calculation as in_cksum.
56 */
57u_int16_t
58ffs_appleufs_cksum(const struct appleufslabel *appleufs)
59{
60	const u_int16_t *p = (const u_int16_t *)appleufs;
61	int len = APPLEUFS_LABEL_SIZE; /* sizeof(struct appleufslabel) */
62	long res = 0;
63	while (len > 1)  {
64		res += *p++;
65		len -= 2;
66	}
67#if 0 /* APPLEUFS_LABEL_SIZE is guaranteed to be even */
68	if (len == 1)
69		res += htobe16(*(u_char *)p<<8);
70#endif
71	res = (res >> 16) + (res & 0xffff);
72	res += (res >> 16);
73	return (~res);
74}
75
76/*
77 * Copies o to n, validating and byteswapping along the way. Returns 0 if ok,
78 * EINVAL if not valid.
79 */
80int
81ffs_appleufs_validate(const char *name, const struct appleufslabel *o,
82    struct appleufslabel *n)
83{
84	struct appleufslabel tmp;
85
86	if (!n)
87		n = &tmp;
88	if (o->ul_magic != be32toh(APPLEUFS_LABEL_MAGIC))
89		return EINVAL;
90
91	*n = *o;
92	n->ul_checksum = 0;
93	n->ul_checksum = ffs_appleufs_cksum(n);
94	n->ul_magic = be32toh(o->ul_magic);
95	n->ul_version = be32toh(o->ul_version);
96	n->ul_time = be32toh(o->ul_time);
97	n->ul_namelen = be16toh(o->ul_namelen);
98
99	if (n->ul_checksum != o->ul_checksum)
100		return EINVAL;
101	if (n->ul_namelen == 0)
102		return EINVAL;
103	if (n->ul_namelen > APPLEUFS_MAX_LABEL_NAME)
104		n->ul_namelen = APPLEUFS_MAX_LABEL_NAME;
105
106	n->ul_name[n->ul_namelen - 1] = '\0';
107
108#ifdef DEBUG
109	printf("%s: found APPLE UFS label v%d: \"%s\"\n", name,
110	    n->ul_version, n->ul_name);
111#endif
112	n->ul_uuid = be64toh(o->ul_uuid);
113
114	return 0;
115}
116
117void
118ffs_appleufs_set(struct appleufslabel *appleufs, const char *name, time_t t,
119    uint64_t uuid)
120{
121	size_t namelen;
122
123	if (!name)
124		name = "untitled";
125	if (t == ((time_t)-1)) {
126#if defined(_KERNEL)
127		t = time_second;
128#elif defined(STANDALONE)
129		t = 0;
130#else
131		(void)time(&t);
132#endif
133	}
134	if (uuid == 0) {
135#if defined(_KERNEL) && !defined(STANDALONE)
136		uuid = cprng_fast64();
137#endif
138	}
139	namelen = strlen(name);
140	if (namelen > APPLEUFS_MAX_LABEL_NAME)
141		namelen = APPLEUFS_MAX_LABEL_NAME;
142	memset(appleufs, 0, APPLEUFS_LABEL_SIZE);
143	appleufs->ul_magic   = htobe32(APPLEUFS_LABEL_MAGIC);
144	appleufs->ul_version = htobe32(APPLEUFS_LABEL_VERSION);
145	appleufs->ul_time    = htobe32((u_int32_t)t);
146	appleufs->ul_namelen = htobe16(namelen);
147	strncpy(appleufs->ul_name, name, namelen);
148	appleufs->ul_uuid    = htobe64(uuid);
149	appleufs->ul_checksum = ffs_appleufs_cksum(appleufs);
150}
151