1*54fd6939SJiyong Park /*
2*54fd6939SJiyong Park * Copyright (c) 2021, Arm Limited and Contributors. All rights reserved.
3*54fd6939SJiyong Park *
4*54fd6939SJiyong Park * SPDX-License-Identifier: BSD-3-Clause
5*54fd6939SJiyong Park */
6*54fd6939SJiyong Park
7*54fd6939SJiyong Park #include <assert.h>
8*54fd6939SJiyong Park #include <errno.h>
9*54fd6939SJiyong Park #include <stdint.h>
10*54fd6939SJiyong Park #include <string.h>
11*54fd6939SJiyong Park
12*54fd6939SJiyong Park #include <common/debug.h>
13*54fd6939SJiyong Park #include <common/uuid.h>
14*54fd6939SJiyong Park
15*54fd6939SJiyong Park /* Return the hex nibble value of a char */
hex_val(char hex)16*54fd6939SJiyong Park static int8_t hex_val(char hex)
17*54fd6939SJiyong Park {
18*54fd6939SJiyong Park int8_t val = 0;
19*54fd6939SJiyong Park
20*54fd6939SJiyong Park if ((hex >= '0') && (hex <= '9')) {
21*54fd6939SJiyong Park val = (int8_t)(hex - '0');
22*54fd6939SJiyong Park } else if ((hex >= 'a') && (hex <= 'f')) {
23*54fd6939SJiyong Park val = (int8_t)(hex - 'a' + 0xa);
24*54fd6939SJiyong Park } else if ((hex >= 'A') && (hex <= 'F')) {
25*54fd6939SJiyong Park val = (int8_t)(hex - 'A' + 0xa);
26*54fd6939SJiyong Park } else {
27*54fd6939SJiyong Park val = -1;
28*54fd6939SJiyong Park }
29*54fd6939SJiyong Park
30*54fd6939SJiyong Park return val;
31*54fd6939SJiyong Park }
32*54fd6939SJiyong Park
33*54fd6939SJiyong Park /*
34*54fd6939SJiyong Park * Read hex_src_len hex characters from hex_src, convert to bytes and
35*54fd6939SJiyong Park * store in buffer pointed to by dest
36*54fd6939SJiyong Park */
read_hex(uint8_t * dest,char * hex_src,unsigned int hex_src_len)37*54fd6939SJiyong Park static int read_hex(uint8_t *dest, char *hex_src, unsigned int hex_src_len)
38*54fd6939SJiyong Park {
39*54fd6939SJiyong Park int8_t nibble;
40*54fd6939SJiyong Park uint8_t byte;
41*54fd6939SJiyong Park
42*54fd6939SJiyong Park /*
43*54fd6939SJiyong Park * The string length must be a multiple of 2 to represent an
44*54fd6939SJiyong Park * exact number of bytes.
45*54fd6939SJiyong Park */
46*54fd6939SJiyong Park assert((hex_src_len % 2U) == 0U);
47*54fd6939SJiyong Park
48*54fd6939SJiyong Park for (unsigned int i = 0U; i < (hex_src_len / 2U); i++) {
49*54fd6939SJiyong Park nibble = 0;
50*54fd6939SJiyong Park byte = 0U;
51*54fd6939SJiyong Park
52*54fd6939SJiyong Park nibble = hex_val(hex_src[2U * i]);
53*54fd6939SJiyong Park if (nibble < 0) {
54*54fd6939SJiyong Park return -1;
55*54fd6939SJiyong Park }
56*54fd6939SJiyong Park byte = (uint8_t)nibble;
57*54fd6939SJiyong Park byte <<= 4U;
58*54fd6939SJiyong Park
59*54fd6939SJiyong Park nibble = hex_val(hex_src[(2U * i) + 1U]);
60*54fd6939SJiyong Park if (nibble < 0) {
61*54fd6939SJiyong Park return -1;
62*54fd6939SJiyong Park }
63*54fd6939SJiyong Park byte |= (uint8_t)nibble;
64*54fd6939SJiyong Park
65*54fd6939SJiyong Park *dest = byte;
66*54fd6939SJiyong Park dest++;
67*54fd6939SJiyong Park }
68*54fd6939SJiyong Park
69*54fd6939SJiyong Park return 0;
70*54fd6939SJiyong Park }
71*54fd6939SJiyong Park
72*54fd6939SJiyong Park /* Parse UUIDs of the form aabbccdd-eeff-4099-8877-665544332211 */
read_uuid(uint8_t * dest,char * uuid)73*54fd6939SJiyong Park int read_uuid(uint8_t *dest, char *uuid)
74*54fd6939SJiyong Park {
75*54fd6939SJiyong Park int err;
76*54fd6939SJiyong Park uint8_t *dest_start = dest;
77*54fd6939SJiyong Park
78*54fd6939SJiyong Park /* Check that we have enough characters */
79*54fd6939SJiyong Park if (strnlen(uuid, UUID_STRING_LENGTH) != UUID_STRING_LENGTH) {
80*54fd6939SJiyong Park WARN("UUID string is too short\n");
81*54fd6939SJiyong Park return -EINVAL;
82*54fd6939SJiyong Park }
83*54fd6939SJiyong Park
84*54fd6939SJiyong Park /* aabbccdd */
85*54fd6939SJiyong Park err = read_hex(dest, uuid, 8);
86*54fd6939SJiyong Park uuid += 8;
87*54fd6939SJiyong Park dest += 4;
88*54fd6939SJiyong Park
89*54fd6939SJiyong Park /* Check for '-' */
90*54fd6939SJiyong Park err |= ((*uuid == '-') ? 0 : -1);
91*54fd6939SJiyong Park uuid++;
92*54fd6939SJiyong Park
93*54fd6939SJiyong Park /* eeff */
94*54fd6939SJiyong Park err |= read_hex(dest, uuid, 4);
95*54fd6939SJiyong Park uuid += 4;
96*54fd6939SJiyong Park dest += 2;
97*54fd6939SJiyong Park
98*54fd6939SJiyong Park /* Check for '-' */
99*54fd6939SJiyong Park err |= ((*uuid == '-') ? 0 : -1);
100*54fd6939SJiyong Park uuid++;
101*54fd6939SJiyong Park
102*54fd6939SJiyong Park /* 4099 */
103*54fd6939SJiyong Park err |= read_hex(dest, uuid, 4);
104*54fd6939SJiyong Park uuid += 4;
105*54fd6939SJiyong Park dest += 2;
106*54fd6939SJiyong Park
107*54fd6939SJiyong Park /* Check for '-' */
108*54fd6939SJiyong Park err |= ((*uuid == '-') ? 0 : -1);
109*54fd6939SJiyong Park uuid++;
110*54fd6939SJiyong Park
111*54fd6939SJiyong Park /* 8877 */
112*54fd6939SJiyong Park err |= read_hex(dest, uuid, 4);
113*54fd6939SJiyong Park uuid += 4;
114*54fd6939SJiyong Park dest += 2;
115*54fd6939SJiyong Park
116*54fd6939SJiyong Park /* Check for '-' */
117*54fd6939SJiyong Park err |= ((*uuid == '-') ? 0 : -1);
118*54fd6939SJiyong Park uuid++;
119*54fd6939SJiyong Park
120*54fd6939SJiyong Park /* 665544332211 */
121*54fd6939SJiyong Park err |= read_hex(dest, uuid, 12);
122*54fd6939SJiyong Park uuid += 12;
123*54fd6939SJiyong Park dest += 6;
124*54fd6939SJiyong Park
125*54fd6939SJiyong Park if (err < 0) {
126*54fd6939SJiyong Park WARN("Error parsing UUID\n");
127*54fd6939SJiyong Park /* Clear the buffer on error */
128*54fd6939SJiyong Park memset((void *)dest_start, '\0', UUID_BYTES_LENGTH * sizeof(uint8_t));
129*54fd6939SJiyong Park return -EINVAL;
130*54fd6939SJiyong Park }
131*54fd6939SJiyong Park
132*54fd6939SJiyong Park return 0;
133*54fd6939SJiyong Park }
134*54fd6939SJiyong Park
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