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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2011 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include "sd-id128.h"
#include "util.h"
#include "macro.h"
_public_ char *sd_id128_to_string(sd_id128_t id, char s[33]) {
unsigned n;
if (!s)
return NULL;
for (n = 0; n < 16; n++) {
s[n*2] = hexchar(id.bytes[n] >> 4);
s[n*2+1] = hexchar(id.bytes[n] & 0xF);
}
s[32] = 0;
return s;
}
_public_ int sd_id128_from_string(const char s[33], sd_id128_t *ret) {
unsigned n;
sd_id128_t t;
if (!s)
return -EINVAL;
if (!ret)
return -EINVAL;
for (n = 0; n < 16; n++) {
int a, b;
a = unhexchar(s[n*2]);
if (a < 0)
return -EINVAL;
b = unhexchar(s[n*2+1]);
if (b < 0)
return -EINVAL;
t.bytes[n] = (a << 4) | b;
}
if (s[32] != 0)
return -EINVAL;
*ret = t;
return 0;
}
_public_ sd_id128_t sd_id128_make_v4_uuid(sd_id128_t id) {
/* Stolen from generate_random_uuid() of drivers/char/random.c
* in the kernel sources */
/* Set UUID version to 4 --- truly random generation */
id.bytes[6] = (id.bytes[6] & 0x0F) | 0x40;
/* Set the UUID variant to DCE */
id.bytes[8] = (id.bytes[8] & 0x3F) | 0x80;
return id;
}
_public_ int sd_id128_get_machine(sd_id128_t *ret) {
static __thread sd_id128_t saved_machine_id;
static __thread bool saved_machine_id_valid = false;
int fd;
char buf[32];
ssize_t k;
unsigned j;
sd_id128_t t;
if (!ret)
return -EINVAL;
if (saved_machine_id_valid) {
*ret = saved_machine_id;
return 0;
}
fd = open("/etc/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0)
return -errno;
k = loop_read(fd, buf, 32, false);
close_nointr_nofail(fd);
if (k < 0)
return (int) k;
if (k < 32)
return -EIO;
for (j = 0; j < 16; j++) {
int a, b;
a = unhexchar(buf[j*2]);
b = unhexchar(buf[j*2+1]);
if (a < 0 || b < 0)
return -EIO;
t.bytes[j] = a << 4 | b;
}
saved_machine_id = t;
saved_machine_id_valid = true;
*ret = t;
return 0;
}
_public_ int sd_id128_get_boot(sd_id128_t *ret) {
static __thread sd_id128_t saved_boot_id;
static __thread bool saved_boot_id_valid = false;
int fd;
char buf[36];
ssize_t k;
unsigned j;
sd_id128_t t;
char *p;
if (!ret)
return -EINVAL;
if (saved_boot_id_valid) {
*ret = saved_boot_id;
return 0;
}
fd = open("/proc/sys/kernel/random/boot_id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0)
return -errno;
k = loop_read(fd, buf, 36, false);
close_nointr_nofail(fd);
if (k < 0)
return (int) k;
if (k < 36)
return -EIO;
for (j = 0, p = buf; j < 16; j++) {
int a, b;
if (*p == '-')
p++;
a = unhexchar(p[0]);
b = unhexchar(p[1]);
if (a < 0 || b < 0)
return -EIO;
t.bytes[j] = a << 4 | b;
p += 2;
}
saved_boot_id = t;
saved_boot_id_valid = true;
*ret = t;
return 0;
}
_public_ int sd_id128_randomize(sd_id128_t *ret) {
int fd;
ssize_t k;
sd_id128_t t;
if (!ret)
return -EINVAL;
fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0)
return -errno;
k = loop_read(fd, &t, 16, false);
close_nointr_nofail(fd);
if (k < 0)
return (int) k;
if (k < 16)
return -EIO;
/* Turn this into a valid v4 UUID, to be nice. Note that we
* only guarantee this for newly generated UUIDs, not for
* pre-existing ones.*/
*ret = sd_id128_make_v4_uuid(t);
return 0;
}
|
