Improve reusability of service_name and uuid components
To allow the service_name and uuid components to be reused
in constrained environments such as 'opteesp', the dependency
on sscanf (stdio.h) is removed and replaced with a portable
hex to byte and string to integer implementation. This allows
the service locator to be used in SPs.
Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I51bf7849d13568ef506c6244cab108e79b8bd09a
diff --git a/components/common/uuid/uuid.c b/components/common/uuid/uuid.c
index 7ce46c2..5d46441 100644
--- a/components/common/uuid/uuid.c
+++ b/components/common/uuid/uuid.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2020-2021, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -7,80 +7,101 @@
#include "uuid.h"
#include <string.h>
#include <ctype.h>
-#include <stdio.h>
+
+static uint8_t hex_to_nibble(char hex)
+{
+ uint8_t nibble = 0;
+
+ if (hex >= '0' && hex <= '9') {
+ nibble = hex - '0';
+ }
+ else {
+ nibble = ((hex | 0x20) - 'a') + 10;
+ }
+
+ return nibble;
+}
+
+static uint8_t hex_to_byte(const char *hex)
+{
+ /* Takes a validated input and returns the byte value */
+ uint8_t byte = hex_to_nibble(hex[0]) << 4;
+ byte |= (hex_to_nibble(hex[1]) & 0x0f);
+ return byte;
+}
size_t uuid_is_valid(const char *canonical_form)
{
- size_t valid_chars = 0;
- size_t input_len = strlen(canonical_form);
+ size_t valid_chars = 0;
+ size_t input_len = strlen(canonical_form);
- if (input_len >= UUID_CANONICAL_FORM_LEN) {
+ if (input_len >= UUID_CANONICAL_FORM_LEN) {
- size_t i;
- valid_chars = UUID_CANONICAL_FORM_LEN;
+ size_t i;
+ valid_chars = UUID_CANONICAL_FORM_LEN;
- for (i = 0; i < UUID_CANONICAL_FORM_LEN; ++i) {
+ for (i = 0; i < UUID_CANONICAL_FORM_LEN; ++i) {
- if (i == 8 || i == 13 || i == 18 || i == 23) {
- if (canonical_form[i] != '-') return 0;
- }
- else {
- if (!isxdigit(canonical_form[i])) return 0;
- }
- }
- }
+ if (i == 8 || i == 13 || i == 18 || i == 23) {
+ if (canonical_form[i] != '-') return 0;
+ }
+ else {
+ if (!isxdigit(canonical_form[i])) return 0;
+ }
+ }
+ }
- return valid_chars;
+ return valid_chars;
}
size_t uuid_parse_to_octets(const char *canonical_form, uint8_t *buf, size_t buf_size)
{
- size_t octet_index = 0;
- const char *pos;
- size_t valid_chars = uuid_is_valid(canonical_form);
+ size_t octet_index = 0;
+ const char *pos;
+ size_t valid_chars = uuid_is_valid(canonical_form);
- if ((buf_size < UUID_OCTETS_LEN) ||
- (valid_chars != UUID_CANONICAL_FORM_LEN)) {
- /* Invalid input */
- return 0;
- }
+ if ((buf_size < UUID_OCTETS_LEN) ||
+ (valid_chars != UUID_CANONICAL_FORM_LEN)) {
+ /* Invalid input */
+ return 0;
+ }
- /*
- * UUID string has been validates as having the following form:
- * xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx
- * 4 2 2 2 6
- */
- pos = &canonical_form[0];
- while (octet_index < 4) {
- sscanf(pos, "%02hhX", &buf[octet_index++]);
- pos += 2;
- }
+ /*
+ * UUID string has been validates as having the following form:
+ * xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx
+ * 4 2 2 2 6
+ */
+ pos = &canonical_form[0];
+ while (octet_index < 4) {
+ buf[octet_index++] = hex_to_byte(pos);
+ pos += 2;
+ }
- pos = &canonical_form[9];
- while (octet_index < 6) {
- sscanf(pos, "%02hhX", &buf[octet_index++]);
- pos += 2;
- }
+ pos = &canonical_form[9];
+ while (octet_index < 6) {
+ buf[octet_index++] = hex_to_byte(pos);
+ pos += 2;
+ }
- pos = &canonical_form[14];
- while (octet_index < 8) {
- sscanf(pos, "%02hhX", &buf[octet_index++]);
- pos += 2;
- }
+ pos = &canonical_form[14];
+ while (octet_index < 8) {
+ buf[octet_index++] = hex_to_byte(pos);
+ pos += 2;
+ }
- pos = &canonical_form[19];
- while (octet_index < 10) {
- sscanf(pos, "%02hhX", &buf[octet_index++]);
- pos += 2;
- }
+ pos = &canonical_form[19];
+ while (octet_index < 10) {
+ buf[octet_index++] = hex_to_byte(pos);
+ pos += 2;
+ }
- pos = &canonical_form[24];
- while (octet_index < 16) {
- sscanf(pos, "%02hhX", &buf[octet_index++]);
- pos += 2;
- }
+ pos = &canonical_form[24];
+ while (octet_index < 16) {
+ buf[octet_index++] = hex_to_byte(pos);
+ pos += 2;
+ }
- return valid_chars;
+ return valid_chars;
}
/*
@@ -91,34 +112,34 @@
*/
size_t uuid_parse_to_octets_reversed(const char *canonical_form, uint8_t *buf, size_t buf_size)
{
- size_t valid_chars;
- uint8_t standard_octets[UUID_OCTETS_LEN];
+ size_t valid_chars;
+ uint8_t standard_octets[UUID_OCTETS_LEN];
- valid_chars = uuid_parse_to_octets(canonical_form, standard_octets, sizeof(standard_octets));
+ valid_chars = uuid_parse_to_octets(canonical_form, standard_octets, sizeof(standard_octets));
- if ((valid_chars == UUID_CANONICAL_FORM_LEN) && (buf_size >= UUID_OCTETS_LEN)) {
- /* Reverse bytes in each section */
- buf[0] = standard_octets[3];
- buf[1] = standard_octets[2];
- buf[2] = standard_octets[1];
- buf[3] = standard_octets[0];
+ if ((valid_chars == UUID_CANONICAL_FORM_LEN) && (buf_size >= UUID_OCTETS_LEN)) {
+ /* Reverse bytes in each section */
+ buf[0] = standard_octets[3];
+ buf[1] = standard_octets[2];
+ buf[2] = standard_octets[1];
+ buf[3] = standard_octets[0];
- buf[4] = standard_octets[5];
- buf[5] = standard_octets[4];
+ buf[4] = standard_octets[5];
+ buf[5] = standard_octets[4];
- buf[6] = standard_octets[7];
- buf[7] = standard_octets[6];
+ buf[6] = standard_octets[7];
+ buf[7] = standard_octets[6];
- buf[8] = standard_octets[8];
- buf[9] = standard_octets[9];
+ buf[8] = standard_octets[8];
+ buf[9] = standard_octets[9];
- buf[10] = standard_octets[10];
- buf[11] = standard_octets[11];
- buf[12] = standard_octets[12];
- buf[13] = standard_octets[13];
- buf[14] = standard_octets[14];
- buf[15] = standard_octets[15];
- }
+ buf[10] = standard_octets[10];
+ buf[11] = standard_octets[11];
+ buf[12] = standard_octets[12];
+ buf[13] = standard_octets[13];
+ buf[14] = standard_octets[14];
+ buf[15] = standard_octets[15];
+ }
- return valid_chars;
+ return valid_chars;
}