1 | /* |
2 | * QEMU UUID functions |
3 | * |
4 | * Copyright 2016 Red Hat, Inc. |
5 | * |
6 | * Authors: |
7 | * Fam Zheng <famz@redhat.com> |
8 | * |
9 | * This program is free software; you can redistribute it and/or modify it |
10 | * under the terms of the GNU General Public License as published by the Free |
11 | * Software Foundation; either version 2 of the License, or (at your option) |
12 | * any later version. |
13 | * |
14 | */ |
15 | |
16 | #include "qemu/osdep.h" |
17 | #include "qemu/uuid.h" |
18 | #include "qemu/bswap.h" |
19 | |
20 | void qemu_uuid_generate(QemuUUID *uuid) |
21 | { |
22 | int i; |
23 | uint32_t tmp[4]; |
24 | |
25 | QEMU_BUILD_BUG_ON(sizeof(QemuUUID) != 16); |
26 | |
27 | for (i = 0; i < 4; ++i) { |
28 | tmp[i] = g_random_int(); |
29 | } |
30 | memcpy(uuid, tmp, sizeof(tmp)); |
31 | /* Set the two most significant bits (bits 6 and 7) of the |
32 | clock_seq_hi_and_reserved to zero and one, respectively. */ |
33 | uuid->data[8] = (uuid->data[8] & 0x3f) | 0x80; |
34 | /* Set the four most significant bits (bits 12 through 15) of the |
35 | time_hi_and_version field to the 4-bit version number. |
36 | */ |
37 | uuid->data[6] = (uuid->data[6] & 0xf) | 0x40; |
38 | } |
39 | |
40 | int qemu_uuid_is_null(const QemuUUID *uu) |
41 | { |
42 | static QemuUUID null_uuid; |
43 | return qemu_uuid_is_equal(uu, &null_uuid); |
44 | } |
45 | |
46 | int qemu_uuid_is_equal(const QemuUUID *lhv, const QemuUUID *rhv) |
47 | { |
48 | return memcmp(lhv, rhv, sizeof(QemuUUID)) == 0; |
49 | } |
50 | |
51 | void qemu_uuid_unparse(const QemuUUID *uuid, char *out) |
52 | { |
53 | const unsigned char *uu = &uuid->data[0]; |
54 | snprintf(out, UUID_FMT_LEN + 1, UUID_FMT, |
55 | uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7], |
56 | uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]); |
57 | } |
58 | |
59 | char *qemu_uuid_unparse_strdup(const QemuUUID *uuid) |
60 | { |
61 | const unsigned char *uu = &uuid->data[0]; |
62 | return g_strdup_printf(UUID_FMT, |
63 | uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], |
64 | uu[7], uu[8], uu[9], uu[10], uu[11], uu[12], |
65 | uu[13], uu[14], uu[15]); |
66 | } |
67 | |
68 | static bool qemu_uuid_is_valid(const char *str) |
69 | { |
70 | int i; |
71 | |
72 | for (i = 0; i < strlen(str); i++) { |
73 | const char c = str[i]; |
74 | if (i == 8 || i == 13 || i == 18 || i == 23) { |
75 | if (str[i] != '-') { |
76 | return false; |
77 | } |
78 | } else { |
79 | if ((c >= '0' && c <= '9') || |
80 | (c >= 'A' && c <= 'F') || |
81 | (c >= 'a' && c <= 'f')) { |
82 | continue; |
83 | } |
84 | return false; |
85 | } |
86 | } |
87 | return i == 36; |
88 | } |
89 | |
90 | int qemu_uuid_parse(const char *str, QemuUUID *uuid) |
91 | { |
92 | unsigned char *uu = &uuid->data[0]; |
93 | int ret; |
94 | |
95 | if (!qemu_uuid_is_valid(str)) { |
96 | return -1; |
97 | } |
98 | |
99 | ret = sscanf(str, UUID_FMT, &uu[0], &uu[1], &uu[2], &uu[3], |
100 | &uu[4], &uu[5], &uu[6], &uu[7], &uu[8], &uu[9], |
101 | &uu[10], &uu[11], &uu[12], &uu[13], &uu[14], |
102 | &uu[15]); |
103 | |
104 | if (ret != 16) { |
105 | return -1; |
106 | } |
107 | return 0; |
108 | } |
109 | |
110 | /* Swap from UUID format endian (BE) to the opposite or vice versa. |
111 | */ |
112 | QemuUUID qemu_uuid_bswap(QemuUUID uuid) |
113 | { |
114 | bswap32s(&uuid.fields.time_low); |
115 | bswap16s(&uuid.fields.time_mid); |
116 | bswap16s(&uuid.fields.time_high_and_version); |
117 | return uuid; |
118 | } |
119 | |