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
qemu_uuid_generate(QemuUUID * uuid)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
qemu_uuid_is_null(const QemuUUID * uu)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
qemu_uuid_is_equal(const QemuUUID * lhv,const QemuUUID * rhv)46 int qemu_uuid_is_equal(const QemuUUID *lhv, const QemuUUID *rhv)
47 {
48 return memcmp(lhv, rhv, sizeof(QemuUUID)) == 0;
49 }
50
qemu_uuid_unparse(const QemuUUID * uuid,char * out)51 void qemu_uuid_unparse(const QemuUUID *uuid, char *out)
52 {
53 const unsigned char *uu = &uuid->data[0];
54 snprintf(out, UUID_STR_LEN, 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
qemu_uuid_unparse_strdup(const QemuUUID * uuid)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
qemu_uuid_is_valid(const char * str)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
qemu_uuid_parse(const char * str,QemuUUID * uuid)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 */
qemu_uuid_bswap(QemuUUID uuid)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
120 /* djb2 hash algorithm */
qemu_uuid_hash(const void * uuid)121 uint32_t qemu_uuid_hash(const void *uuid)
122 {
123 QemuUUID *qid = (QemuUUID *) uuid;
124 uint32_t h = 5381;
125 int i;
126
127 for (i = 0; i < ARRAY_SIZE(qid->data); i++) {
128 h = (h << 5) + h + qid->data[i];
129 }
130
131 return h;
132 }
133