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87d2c1ff LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2011 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <errno.h> | |
23 | #include <fcntl.h> | |
24 | #include <unistd.h> | |
25 | ||
26 | #include "sd-id128.h" | |
81527be1 | 27 | |
87d2c1ff LP |
28 | #include "util.h" |
29 | #include "macro.h" | |
30 | ||
000a2c98 | 31 | _public_ char *sd_id128_to_string(sd_id128_t id, char s[33]) { |
87d2c1ff LP |
32 | unsigned n; |
33 | ||
000a2c98 LP |
34 | if (!s) |
35 | return NULL; | |
87d2c1ff LP |
36 | |
37 | for (n = 0; n < 16; n++) { | |
38 | s[n*2] = hexchar(id.bytes[n] >> 4); | |
39 | s[n*2+1] = hexchar(id.bytes[n] & 0xF); | |
40 | } | |
41 | ||
42 | s[32] = 0; | |
43 | ||
44 | return s; | |
45 | } | |
46 | ||
000a2c98 | 47 | _public_ int sd_id128_from_string(const char s[33], sd_id128_t *ret) { |
87d2c1ff LP |
48 | unsigned n; |
49 | sd_id128_t t; | |
50 | ||
000a2c98 LP |
51 | if (!s) |
52 | return -EINVAL; | |
53 | if (!ret) | |
54 | return -EINVAL; | |
87d2c1ff LP |
55 | |
56 | for (n = 0; n < 16; n++) { | |
57 | int a, b; | |
58 | ||
59 | a = unhexchar(s[n*2]); | |
60 | if (a < 0) | |
61 | return -EINVAL; | |
62 | ||
63 | b = unhexchar(s[n*2+1]); | |
64 | if (b < 0) | |
65 | return -EINVAL; | |
66 | ||
67 | t.bytes[n] = (a << 4) | b; | |
68 | } | |
69 | ||
70 | if (s[32] != 0) | |
71 | return -EINVAL; | |
72 | ||
73 | *ret = t; | |
74 | return 0; | |
75 | } | |
76 | ||
e4bac488 | 77 | static sd_id128_t make_v4_uuid(sd_id128_t id) { |
87d2c1ff LP |
78 | /* Stolen from generate_random_uuid() of drivers/char/random.c |
79 | * in the kernel sources */ | |
80 | ||
81 | /* Set UUID version to 4 --- truly random generation */ | |
82 | id.bytes[6] = (id.bytes[6] & 0x0F) | 0x40; | |
83 | ||
84 | /* Set the UUID variant to DCE */ | |
85 | id.bytes[8] = (id.bytes[8] & 0x3F) | 0x80; | |
86 | ||
87 | return id; | |
88 | } | |
89 | ||
000a2c98 | 90 | _public_ int sd_id128_get_machine(sd_id128_t *ret) { |
87d2c1ff LP |
91 | static __thread sd_id128_t saved_machine_id; |
92 | static __thread bool saved_machine_id_valid = false; | |
93 | int fd; | |
94 | char buf[32]; | |
95 | ssize_t k; | |
96 | unsigned j; | |
97 | sd_id128_t t; | |
98 | ||
000a2c98 LP |
99 | if (!ret) |
100 | return -EINVAL; | |
101 | ||
87d2c1ff LP |
102 | if (saved_machine_id_valid) { |
103 | *ret = saved_machine_id; | |
104 | return 0; | |
105 | } | |
106 | ||
107 | fd = open("/etc/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
108 | if (fd < 0) | |
109 | return -errno; | |
110 | ||
111 | k = loop_read(fd, buf, 32, false); | |
112 | close_nointr_nofail(fd); | |
113 | ||
114 | if (k < 0) | |
115 | return (int) k; | |
116 | ||
117 | if (k < 32) | |
118 | return -EIO; | |
119 | ||
120 | for (j = 0; j < 16; j++) { | |
121 | int a, b; | |
122 | ||
123 | a = unhexchar(buf[j*2]); | |
124 | b = unhexchar(buf[j*2+1]); | |
125 | ||
126 | if (a < 0 || b < 0) | |
127 | return -EIO; | |
128 | ||
129 | t.bytes[j] = a << 4 | b; | |
130 | } | |
131 | ||
132 | saved_machine_id = t; | |
133 | saved_machine_id_valid = true; | |
134 | ||
135 | *ret = t; | |
136 | return 0; | |
137 | } | |
138 | ||
000a2c98 | 139 | _public_ int sd_id128_get_boot(sd_id128_t *ret) { |
87d2c1ff LP |
140 | static __thread sd_id128_t saved_boot_id; |
141 | static __thread bool saved_boot_id_valid = false; | |
142 | int fd; | |
143 | char buf[36]; | |
144 | ssize_t k; | |
145 | unsigned j; | |
146 | sd_id128_t t; | |
147 | char *p; | |
148 | ||
000a2c98 LP |
149 | if (!ret) |
150 | return -EINVAL; | |
151 | ||
87d2c1ff LP |
152 | if (saved_boot_id_valid) { |
153 | *ret = saved_boot_id; | |
154 | return 0; | |
155 | } | |
156 | ||
157 | fd = open("/proc/sys/kernel/random/boot_id", O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
158 | if (fd < 0) | |
159 | return -errno; | |
160 | ||
161 | k = loop_read(fd, buf, 36, false); | |
162 | close_nointr_nofail(fd); | |
163 | ||
164 | if (k < 0) | |
165 | return (int) k; | |
166 | ||
167 | if (k < 36) | |
168 | return -EIO; | |
169 | ||
170 | for (j = 0, p = buf; j < 16; j++) { | |
171 | int a, b; | |
172 | ||
173 | if (*p == '-') | |
174 | p++; | |
175 | ||
176 | a = unhexchar(p[0]); | |
177 | b = unhexchar(p[1]); | |
178 | ||
179 | if (a < 0 || b < 0) | |
180 | return -EIO; | |
181 | ||
182 | t.bytes[j] = a << 4 | b; | |
183 | ||
184 | p += 2; | |
185 | } | |
186 | ||
187 | saved_boot_id = t; | |
188 | saved_boot_id_valid = true; | |
189 | ||
190 | *ret = t; | |
191 | return 0; | |
192 | } | |
193 | ||
000a2c98 | 194 | _public_ int sd_id128_randomize(sd_id128_t *ret) { |
87d2c1ff LP |
195 | int fd; |
196 | ssize_t k; | |
197 | sd_id128_t t; | |
198 | ||
000a2c98 LP |
199 | if (!ret) |
200 | return -EINVAL; | |
87d2c1ff LP |
201 | |
202 | fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
203 | if (fd < 0) | |
204 | return -errno; | |
205 | ||
206 | k = loop_read(fd, &t, 16, false); | |
207 | close_nointr_nofail(fd); | |
208 | ||
209 | if (k < 0) | |
210 | return (int) k; | |
211 | ||
212 | if (k < 16) | |
213 | return -EIO; | |
214 | ||
215 | /* Turn this into a valid v4 UUID, to be nice. Note that we | |
216 | * only guarantee this for newly generated UUIDs, not for | |
217 | * pre-existing ones.*/ | |
218 | ||
e4bac488 | 219 | *ret = make_v4_uuid(t); |
87d2c1ff LP |
220 | return 0; |
221 | } |