summaryrefslogtreecommitdiffstats
path: root/lib/uuid/uuid.c
blob: bff912dec7d037c73c4d20e62f0eb3e75d9a0db0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 * Copyright (C) 2001 Sistina Software (UK) Limited.
 *
 * This file is released under the LGPL.
 */

#include "uuid.h"
#include "log.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>

static unsigned char _c[] =
    "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

static int _built_inverse;
static unsigned char _inverse_c[256];

int lvid_create(union lvid *lvid, struct id *vgid)
{
	memcpy(lvid->id, vgid, sizeof(*lvid->id));
	id_create(&lvid->id[1]);

	return 1;
}

int lvid_from_lvnum(union lvid *lvid, struct id *vgid, int lv_num)
{
	int i;

	memcpy(lvid->id, vgid, sizeof(*lvid->id));

	for (i = ID_LEN; i; i--) {
		lvid->id[1].uuid[i - 1] = _c[lv_num % (sizeof(_c) - 1)];
		lv_num /= sizeof(_c) - 1;
	}

	lvid->s[sizeof(lvid->s) - 1] = '\0';

	return 1;
}

int lvnum_from_lvid(union lvid *lvid)
{
	int i, lv_num = 0;
	unsigned char *c;

	for (i = 0; i < ID_LEN; i++) {
		lv_num *= sizeof(_c) - 1;
		if ((c = strchr(_c, lvid->id[1].uuid[i])))
			lv_num += (int) (c - _c);
	}

	return lv_num;
}

int id_create(struct id *id)
{
	int random, i, len = sizeof(id->uuid);

	memset(id->uuid, 0, len);
	if ((random = open("/dev/urandom", O_RDONLY)) < 0) {
		log_sys_error("open", "id_create");
		return 0;
	}

	if (read(random, id->uuid, len) != len) {
		log_sys_error("read", "id_create");
		close(random);
		return 0;
	}
	close(random);

	for (i = 0; i < len; i++)
		id->uuid[i] = _c[id->uuid[i] % (sizeof(_c) - 1)];

	return 1;
}

/*
 * The only validity check we have is that
 * the uuid just contains characters from
 * '_c'.  A checksum would have been nice :(
 */
void _build_inverse(void)
{
	char *ptr;

	if (_built_inverse)
		return;

	memset(_inverse_c, 0, sizeof(_inverse_c));

	for (ptr = _c; *ptr; ptr++)
		_inverse_c[(int) *ptr] = (char) 0x1;
}

int id_valid(struct id *id)
{
	int i;

	_build_inverse();

	for (i = 0; i < ID_LEN; i++)
		if (!_inverse_c[id->uuid[i]]) {
			log_err("UUID contains invalid character");
			return 0;
		}

	return 1;
}

int id_equal(struct id *lhs, struct id *rhs)
{
	return !memcmp(lhs->uuid, rhs->uuid, sizeof(lhs->uuid));
}

#define GROUPS (ID_LEN / 4)

int id_write_format(struct id *id, char *buffer, size_t size)
{
	int i, tot;

	static int group_size[] = { 6, 4, 4, 4, 4, 4, 6 };

	assert(ID_LEN == 32);

	/* split into groups seperated by dashes */
	if (size < (32 + 6 + 1)) {
		log_err("Couldn't write uuid, buffer too small.");
		return 0;
	}

	for (i = 0, tot = 0; i < 7; i++) {
		memcpy(buffer, id->uuid + tot, group_size[i]);
		buffer += group_size[i];
		tot += group_size[i];
		*buffer++ = '-';
	}

	*--buffer = '\0';
	return 1;
}

int id_read_format(struct id *id, char *buffer)
{
	int out = 0;

	/* just strip out any dashes */
	while (*buffer) {

		if (*buffer == '-') {
			buffer++;
			continue;
		}

		if (out >= ID_LEN) {
			log_err("Too many characters to be uuid.");
			return 0;
		}

		id->uuid[out++] = *buffer++;
	}

	if (out != ID_LEN) {
		log_err("Couldn't read uuid, incorrect number of characters.");
		return 0;
	}

	return id_valid(id);
}