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/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <error/s2n_errno.h>
#include "utils/s2n_rfc5952.h"
#include "utils/s2n_safety.h"
static uint8_t dec[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
static uint8_t hex[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
S2N_RESULT s2n_inet_ntop(int af, const void *addr, struct s2n_blob *dst)
{
const uint8_t *bytes = addr;
uint8_t *cursor = dst->data;
if (af == AF_INET) {
ENSURE(dst->size >= sizeof("111.222.333.444"), S2N_ERR_SIZE_MISMATCH);
for (int i = 0; i < 4; i++) {
if (bytes[i] / 100) {
*cursor++ = dec[bytes[i] / 100];
}
if (bytes[i] >= 10) {
*cursor++ = dec[(bytes[i] % 100) / 10];
}
*cursor++ = dec[(bytes[i] % 10)];
*cursor++ = '.';
}
*--cursor = '\0';
return S2N_RESULT_OK;
}
if (af == AF_INET6) {
ENSURE(dst->size >= sizeof("1111:2222:3333:4444:5555:6666:7777:8888"), S2N_ERR_SIZE_MISMATCH);
/* See Section 4 of RFC5952 for the rules we are going to follow here
*
* Here's the general algorithm:
*
* 1/ Treat the bytes as 8 16-bit fields
* 2/ Find the longest run of 16-bit fields.
* 3/ or if there are two or more equal length longest runs, go with the left-most run
* 4/ Make that run ::
* 5/ Print the remaining 16-bit fields in lowercase hex, no leading zeroes
*/
uint16_t octets[8] = { 0 };
int longest_run_start = 0;
int longest_run_length = 0;
int current_run_length = 0;
/* 2001:db8::1:0:0:1 */
/* Find the longest run of zeroes */
for (int i = 0; i < 8; i++) {
octets[i] = (bytes[i * 2] << 8) + bytes[(i * 2) + 1];
if (octets[i]) {
current_run_length = 0;
}
else {
current_run_length++;
}
if (current_run_length > longest_run_length) {
longest_run_length = current_run_length;
longest_run_start = (i - current_run_length) + 1;
}
}
for (int i = 0; i < 8; i++) {
if (i == longest_run_start && longest_run_length > 1) {
if (i == 0) {
*cursor++ = ':';
}
if (longest_run_length == 8) {
*cursor++ = ':';
}
i += longest_run_length - 1;
}
else {
uint8_t nibbles[4] = { (octets[i] & 0xF000) >> 12,
(octets[i] & 0x0F00) >> 8,
(octets[i] & 0x00F0) >> 4,
(octets[i] & 0x000F) };
/* Skip up to three leading zeroes */
int j;
for (j = 0; j < 3; j++) {
if (nibbles[j]) {
break;
}
}
for (; j < 4; j++) {
*cursor++ = hex[ nibbles[j] ];
}
}
*cursor++ = ':';
}
*--cursor = '\0';
return S2N_RESULT_OK;
}
BAIL(S2N_ERR_INVALID_ARGUMENT);
}
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