Refactor ipv6 parsing
Introduce new variables to make it more readable. Clarify the calculations a bit.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 3c9d613..012c536 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -2571,7 +2571,7 @@
static int x509_inet_pton_ipv6(const char *src, void *dst)
{
const unsigned char *character = (const unsigned char *) src;
- int num_groups = 0, num_digits, zero_group_start = -1;
+ int nonzero_groups = 0, num_digits, zero_group_start = -1;
uint16_t addr[8];
do {
/* note: allows excess leading 0's, e.g. 1:0002:3:... */
@@ -2581,16 +2581,19 @@
;
}
if (num_digits != 0) {
- addr[num_groups++] = MBEDTLS_IS_BIG_ENDIAN ? group : (group << 8) | (group >> 8);
+ addr[nonzero_groups++] = MBEDTLS_IS_BIG_ENDIAN ? group :
+ (group << 8) | (group >> 8);
if (*character == '\0') {
break;
- } else if (*character == '.' && (num_groups != 0 || zero_group_start != -1) &&
- (num_groups < 7) &&
+ } else if (*character == '.' && (nonzero_groups != 0 ||
+ zero_group_start != -1) &&
+ (nonzero_groups < 7) &&
/* walk back to prior ':', then parse as IPv4-mapped */
(*--character == ':' || *--character == ':' ||
*--character == ':' || *--character == ':') &&
- x509_inet_pton_ipv4((const char *) ++character, addr + --num_groups) == 0) {
- num_groups += 2;
+ x509_inet_pton_ipv4((const char *) ++character,
+ addr + --nonzero_groups) == 0) {
+ nonzero_groups += 2;
character = (const unsigned char *) "";
break;
} else if (*character != ':') {
@@ -2598,7 +2601,8 @@
}
} else {
if (zero_group_start != -1 || *character != ':' ||
- ((zero_group_start = num_groups) == 0 && *++character != ':')) {
+ ((zero_group_start = nonzero_groups) == 0 &&
+ *++character != ':')) {
return -1;
}
if (character[1] == '\0') {
@@ -2607,21 +2611,23 @@
}
}
++character;
- } while (num_groups < 8);
- if ((zero_group_start != -1 ? num_groups > 6 : num_groups != 8) || *character != '\0') {
+ } while (nonzero_groups < 8);
+ if ((zero_group_start != -1 ? nonzero_groups > 6 : nonzero_groups != 8) ||
+ *character != '\0') {
return -1;
}
if (zero_group_start != -1) {
- int num_zero_groups = 0;
- num_groups -= zero_group_start;
- num_zero_groups = 8 - num_groups - zero_group_start;
- if (num_groups) {
- memmove(addr + zero_group_start + num_zero_groups,
+ int zero_groups = 8 - nonzero_groups;
+ int groups_after_zero = nonzero_groups - zero_group_start;
+
+ /* Move the non-zero part to after the zeroes */
+ if (groups_after_zero) {
+ memmove(addr + zero_group_start + zero_groups,
addr + zero_group_start,
- num_groups * sizeof(*addr));
+ groups_after_zero * sizeof(*addr));
}
- memset(addr + zero_group_start, 0, num_zero_groups * sizeof(*addr));
+ memset(addr + zero_group_start, 0, zero_groups * sizeof(*addr));
}
memcpy(dst, addr, sizeof(addr));
return 0;