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
|
/*
* Copyright (c) 2021-2022, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <errno.h>
#include <stdint.h>
#include <string.h>
#include <common/debug.h>
#include <common/uuid.h>
/* Return the hex nibble value of a char */
static int8_t hex_val(char hex)
{
int8_t val = 0;
if ((hex >= '0') && (hex <= '9')) {
val = (int8_t)(hex - '0');
} else if ((hex >= 'a') && (hex <= 'f')) {
val = (int8_t)(hex - 'a' + 0xa);
} else if ((hex >= 'A') && (hex <= 'F')) {
val = (int8_t)(hex - 'A' + 0xa);
} else {
val = -1;
}
return val;
}
/*
* Read hex_src_len hex characters from hex_src, convert to bytes and
* store in buffer pointed to by dest
*/
static int read_hex(uint8_t *dest, char *hex_src, unsigned int hex_src_len)
{
int8_t nibble;
uint8_t byte;
/*
* The string length must be a multiple of 2 to represent an
* exact number of bytes.
*/
assert((hex_src_len % 2U) == 0U);
for (unsigned int i = 0U; i < (hex_src_len / 2U); i++) {
nibble = 0;
byte = 0U;
nibble = hex_val(hex_src[2U * i]);
if (nibble < 0) {
return -1;
}
byte = (uint8_t)nibble;
byte <<= 4U;
nibble = hex_val(hex_src[(2U * i) + 1U]);
if (nibble < 0) {
return -1;
}
byte |= (uint8_t)nibble;
*dest = byte;
dest++;
}
return 0;
}
/* Parse UUIDs of the form aabbccdd-eeff-4099-8877-665544332211 */
int read_uuid(uint8_t *dest, char *uuid)
{
int err;
uint8_t *dest_start = dest;
/* Check that we have enough characters */
if (strnlen(uuid, UUID_STRING_LENGTH) != UUID_STRING_LENGTH) {
WARN("UUID string is too short\n");
return -EINVAL;
}
/* aabbccdd */
err = read_hex(dest, uuid, 8);
uuid += 8;
dest += 4;
/* Check for '-' */
err |= ((*uuid == '-') ? 0 : -1);
uuid++;
/* eeff */
err |= read_hex(dest, uuid, 4);
uuid += 4;
dest += 2;
/* Check for '-' */
err |= ((*uuid == '-') ? 0 : -1);
uuid++;
/* 4099 */
err |= read_hex(dest, uuid, 4);
uuid += 4;
dest += 2;
/* Check for '-' */
err |= ((*uuid == '-') ? 0 : -1);
uuid++;
/* 8877 */
err |= read_hex(dest, uuid, 4);
uuid += 4;
dest += 2;
/* Check for '-' */
err |= ((*uuid == '-') ? 0 : -1);
uuid++;
/* 665544332211 */
err |= read_hex(dest, uuid, 12);
uuid += 12;
dest += 6;
if (err < 0) {
WARN("Error parsing UUID\n");
/* Clear the buffer on error */
memset((void *)dest_start, '\0', UUID_BYTES_LENGTH * sizeof(uint8_t));
return -EINVAL;
}
return 0;
}
/*
* Helper function to check if 2 UUIDs match.
*/
bool uuid_match(uint32_t *uuid1, uint32_t *uuid2)
{
return !memcmp(uuid1, uuid2, sizeof(uint32_t) * 4);
}
/*
* Helper function to copy from one UUID struct to another.
*/
void copy_uuid(uint32_t *to_uuid, uint32_t *from_uuid)
{
to_uuid[0] = from_uuid[0];
to_uuid[1] = from_uuid[1];
to_uuid[2] = from_uuid[2];
to_uuid[3] = from_uuid[3];
}
bool is_null_uuid(uint32_t *uuid)
{
return (uuid[0] == 0 && uuid[1] == 0 &&
uuid[2] == 0 && uuid[3] == 0);
}
|
