mbed-os/connectivity/libraries/nanostack-libservice/source/libip4string/ip4tos.c

75 lines
2.2 KiB
C

/*
* Copyright (c) 2014-2018, Pelion and affiliates.
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License 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 <stdio.h>
#include <string.h>
#include "common_functions.h"
#include "ip4string.h"
static void ipv4_itoa(char *string, uint8_t byte);
/**
* Print binary IPv4 address to a string.
* String must contain enough room for full address, 16 bytes exact.
* \param addr IPv4 address.
* \p buffer to write string to.
*/
uint_fast8_t ip4tos(const void *ip4addr, char *p)
{
uint_fast8_t outputPos = 0;
const uint8_t *byteArray = ip4addr;
for (uint_fast8_t component = 0; component < 4; ++component) {
//Convert the byte to string
ipv4_itoa(&p[outputPos], byteArray[component]);
//Move outputPos to the end of the string
while (p[outputPos] != '\0') {
outputPos += 1;
}
//Append a dot if this is not the last digit
if (component < 3) {
p[outputPos++] = '.';
}
}
// Return length of generated string, excluding the terminating null character
return outputPos;
}
static void ipv4_itoa(char *string, uint8_t byte)
{
char *baseString = string;
//Write the digits to the buffer from the least significant to the most
// This is the incorrect order but we will swap later
do {
*string++ = '0' + byte % 10;
byte /= 10;
} while (byte);
//We put the final \0, then go back one step on the last digit for the swap
*string-- = '\0';
//We now swap the digits
while (baseString < string) {
uint8_t tmp = *string;
*string-- = *baseString;
*baseString++ = tmp;
}
}