1
0
Fork 0
mirror of https://gitlab.com/sortix/sortix.git synced 2023-02-13 20:55:38 -05:00
sortix--sortix/libc/arpa/inet/inet_ntop.c

96 lines
2.8 KiB
C

/*
* Copyright (c) 2016, 2020 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* arpa/inet/inet_ntop.c
* Convert network address to string.
*/
#include <sys/socket.h>
#include <errno.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
const char* inet_ntop(int af,
const void* restrict src,
char* restrict dst,
socklen_t size)
{
if ( af == AF_INET )
{
const unsigned char* ip = (const unsigned char*) src;
int len = snprintf(dst, size, "%u.%u.%u.%u",
ip[0], ip[1], ip[2], ip[3]);
if ( len < 0 )
return NULL;
if ( size <= (size_t) len )
return errno = ENOSPC, (const char*) NULL;
return dst;
}
else if ( af == AF_INET6 )
{
// TODO: When should x:x:x:x:x:x:d.d.d.d notation be used?
const unsigned char* ip = (const unsigned char*) src;
size_t longest_zeroes_offset = 0;
size_t longest_zeroes_length = 0;
size_t current_zeroes_offset = 0;
size_t current_zeroes_length = 0;
for ( size_t i = 0; i < 8; i++ )
{
const unsigned char* data = ip + i * 2;
if ( !data[0] && !data[1] )
{
current_zeroes_length++;
if ( longest_zeroes_length < current_zeroes_length )
{
longest_zeroes_offset = current_zeroes_offset;
longest_zeroes_length = current_zeroes_length;
}
}
else
{
current_zeroes_offset = i + 1;
current_zeroes_length = 0;
}
}
char buffer[INET6_ADDRSTRLEN];
size_t offset = 0;
for ( size_t i = 0; i < 8; i++ )
{
const unsigned char* data = ip + i * 2;
if ( i == longest_zeroes_offset && 2 <= longest_zeroes_length )
{
buffer[offset++] = ':';
buffer[offset++] = ':';
i += longest_zeroes_length - 1;
}
else
{
if ( offset && buffer[offset - 1] != ':' )
buffer[offset++] = ':';
offset += snprintf(buffer + offset, sizeof(buffer) - offset,
"%x", data[0] << 8 | data[1]);
}
}
buffer[offset] = '\0';
if ( size <= (size_t) offset )
return errno = ENOSPC, (const char*) NULL;
memcpy(dst, buffer, offset + 1);
return dst;
}
else
return errno = EAFNOSUPPORT, NULL;
}