os2_ip4tos.c

00001 /*
00002  * Copyright (c) 2014-2018 ARM Limited. All rights reserved.
00003  * SPDX-License-Identifier: Apache-2.0
00004  * Licensed under the Apache License, Version 2.0 (the License); you may
00005  * not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  * http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00012  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include "mbed_version.h"
00017 
00018 #if MBED_MAJOR_VERSION == 2
00019 
00020 #include <stdio.h>
00021 #include <string.h>
00022 #include "common_functions.h"
00023 #include "ip4string.h"
00024 
00025 static void ipv4_itoa(char *string, uint8_t byte);
00026 
00027 /**
00028  * Print binary IPv4 address to a string.
00029  * String must contain enough room for full address, 16 bytes exact.
00030  * \param addr IPv4 address.
00031  * \p buffer to write string to.
00032  */
00033 uint_fast8_t ip4tos(const void *ip4addr, char *p)
00034 {
00035     uint_fast8_t outputPos = 0;
00036     const uint8_t *byteArray = ip4addr;
00037 
00038     for (uint_fast8_t component = 0; component < 4; ++component) {
00039         //Convert the byte to string
00040         ipv4_itoa(&p[outputPos], byteArray[component]);
00041 
00042         //Move outputPos to the end of the string
00043         while (p[outputPos] != '\0') {
00044             outputPos += 1;
00045         }
00046 
00047         //Append a dot if this is not the last digit
00048         if (component < 3) {
00049             p[outputPos++] = '.';
00050         }
00051     }
00052 
00053     // Return length of generated string, excluding the terminating null character
00054     return outputPos;
00055 }
00056 
00057 static void ipv4_itoa(char *string, uint8_t byte)
00058 {
00059     char *baseString = string;
00060 
00061     //Write the digits to the buffer from the least significant to the most
00062     //  This is the incorrect order but we will swap later
00063     do {
00064         *string++ = '0' + byte % 10;
00065         byte /= 10;
00066     } while (byte);
00067 
00068     //We put the final \0, then go back one step on the last digit for the swap
00069     *string-- = '\0';
00070 
00071     //We now swap the digits
00072     while (baseString < string) {
00073         uint8_t tmp = *string;
00074         *string-- = *baseString;
00075         *baseString++ = tmp;
00076     }
00077 }
00078 #endif