limine/common/lib/guid.c

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#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <lib/guid.h>
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#include <lib/misc.h>
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bool is_valid_guid(const char *s) {
for (size_t i = 0; ; i++) {
switch (i) {
case 8:
case 13:
case 18:
case 23:
if (s[i] != '-')
return false;
break;
case 36:
return s[i] == 0;
default:
if (digit_to_int(s[i]) == -1)
return false;
break;
}
}
}
static void guid_convert_le_cluster(uint8_t *dest, const char *s, int len) {
size_t p = 0;
for (int i = len - 1; i >= 0; i--) {
int val = digit_to_int(s[i]);
i % 2 ? (dest[p] = val) : (dest[p++] |= val << 4);
}
}
static void guid_convert_be_cluster(uint8_t *dest, const char *s, int len) {
size_t p = 0;
for (int i = 0; i < len; i++) {
int val = digit_to_int(s[i]);
i % 2 ? (dest[p++] |= val) : (dest[p] = val << 4);
}
}
bool string_to_guid_be(struct guid *guid, const char *s) {
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if (!is_valid_guid(s))
return false;
guid_convert_be_cluster((uint8_t *)guid + 0, s + 0, 8);
guid_convert_be_cluster((uint8_t *)guid + 4, s + 9, 4);
guid_convert_be_cluster((uint8_t *)guid + 6, s + 14, 4);
guid_convert_be_cluster((uint8_t *)guid + 8, s + 19, 4);
guid_convert_be_cluster((uint8_t *)guid + 10, s + 24, 12);
return true;
}
bool string_to_guid_mixed(struct guid *guid, const char *s) {
if (!is_valid_guid(s))
return false;
guid_convert_le_cluster((uint8_t *)guid + 0, s + 0, 8);
guid_convert_le_cluster((uint8_t *)guid + 4, s + 9, 4);
guid_convert_le_cluster((uint8_t *)guid + 6, s + 14, 4);
guid_convert_be_cluster((uint8_t *)guid + 8, s + 19, 4);
guid_convert_be_cluster((uint8_t *)guid + 10, s + 24, 12);
return true;
}