1 /*        $NetBSD: ffs_appleufs.c,v 1.15 2015/02/15 11:04:43 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 1.15 2015/02/15 11:04:43 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  */
57 u_int16_t
ffs_appleufs_cksum(const struct appleufslabel * appleufs)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 /*
77  * Copies o to n, validating and byteswapping along the way. Returns 0 if ok,
78  * EINVAL if not valid.
79  */
80 int
ffs_appleufs_validate(const char * name,const struct appleufslabel * o,struct appleufslabel * n)81 ffs_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 
117 void
ffs_appleufs_set(struct appleufslabel * appleufs,const char * name,time_t t,uint64_t uuid)118 ffs_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