xref: /netbsd-src/sys/ufs/ffs/ffs_appleufs.c (revision 48fb7bfab72acd4281a53bbee5ccf3f809019e75)
1 /*	$NetBSD: ffs_appleufs.c,v 1.12 2011/11/19 22:51:31 tls 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 1.12 2011/11/19 22:51:31 tls 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  */
57 u_int16_t
58 ffs_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 /* copies o to n, validating and byteswapping along the way
77  * returns 0 if ok, EINVAL if not valid
78  */
79 int
80 ffs_appleufs_validate(const char *name, const struct appleufslabel *o,
81     struct appleufslabel *n)
82 {
83 	struct appleufslabel tmp;
84 	if (!n) n = &tmp;
85 
86 	if (o->ul_magic != be32toh(APPLEUFS_LABEL_MAGIC)) {
87 		return EINVAL;
88 	}
89 	*n = *o;
90 	n->ul_checksum = 0;
91 	n->ul_checksum = ffs_appleufs_cksum(n);
92 	if (n->ul_checksum != o->ul_checksum) {
93 #if defined(DIAGNOSTIC) || !defined(_KERNEL)
94 		printf("%s: invalid APPLE UFS checksum. found 0x%x, expecting 0x%x",
95 			name,o->ul_checksum,n->ul_checksum);
96 #endif
97 		return EINVAL;
98 	}
99 	n->ul_magic = be32toh(o->ul_magic);
100 	n->ul_version = be32toh(o->ul_version);
101 	n->ul_time = be32toh(o->ul_time);
102 	n->ul_namelen = be16toh(o->ul_namelen);
103 
104 	if (n->ul_namelen > APPLEUFS_MAX_LABEL_NAME) {
105 #if defined(DIAGNOSTIC) || !defined(_KERNEL)
106 		printf("%s: APPLE UFS label name too long, truncated.\n",
107 				name);
108 #endif
109 		n->ul_namelen = APPLEUFS_MAX_LABEL_NAME;
110 	}
111 	/* if len is max, will set ul_unused1 */
112 	n->ul_name[n->ul_namelen - 1] = '\0';
113 
114 #ifdef DEBUG
115 	printf("%s: found APPLE UFS label v%d: \"%s\"\n",
116 	    name,n->ul_version,n->ul_name);
117 #endif
118 	n->ul_uuid = be64toh(o->ul_uuid);
119 
120 	return 0;
121 }
122 
123 void
124 ffs_appleufs_set(struct appleufslabel *appleufs, const char *name, time_t t,
125     uint64_t uuid)
126 {
127 	size_t namelen;
128 	if (!name) name = "untitled";
129 	if (t == ((time_t)-1)) {
130 #if defined(_KERNEL)
131 		t = time_second;
132 #elif defined(STANDALONE)
133 		t = 0;
134 #else
135 		(void)time(&t);
136 #endif
137 	}
138 	if (uuid == 0) {
139 #if defined(_KERNEL) && !defined(STANDALONE)
140 		uuid = cprng_fast64();
141 #endif
142 	}
143 	namelen = strlen(name);
144 	if (namelen > APPLEUFS_MAX_LABEL_NAME)
145 		namelen = APPLEUFS_MAX_LABEL_NAME;
146 	memset(appleufs, 0, APPLEUFS_LABEL_SIZE);
147 	appleufs->ul_magic   = htobe32(APPLEUFS_LABEL_MAGIC);
148 	appleufs->ul_version = htobe32(APPLEUFS_LABEL_VERSION);
149 	appleufs->ul_time    = htobe32((u_int32_t)t);
150 	appleufs->ul_namelen = htobe16(namelen);
151 	strncpy(appleufs->ul_name,name,namelen);
152 	appleufs->ul_uuid    = htobe64(uuid);
153 	appleufs->ul_checksum = ffs_appleufs_cksum(appleufs);
154 }
155