cosmopolitan/libc/sock/inet_ntop.c

62 lines
2.9 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/fmt/itoa.h"
#include "libc/sysv/consts/af.h"
#include "libc/sysv/errfuns.h"
/**
* Formats internet address to string.
*
* @param af can be AF_INET
* @param src is the binary-encoded address, e.g. &addr->sin_addr
* @param dst is the output string buffer
* @param size is bytes in dst, which needs 16+ for IPv4
* @return dst on success or NULL w/ errno
*/
const char *inet_ntop(int af, const void *src, char *dst, uint32_t size) {
char *p;
unsigned char *ip4;
if (src) {
if (af == AF_INET) {
if (size >= 16) {
p = dst;
ip4 = src;
p += uint64toarray_radix10(ip4[0], p);
*p++ = '.';
p += uint64toarray_radix10(ip4[1], p);
*p++ = '.';
p += uint64toarray_radix10(ip4[2], p);
*p++ = '.';
p += uint64toarray_radix10(ip4[3], p);
*p = '\0';
return dst;
} else {
enospc();
}
} else {
eafnosupport();
}
} else {
einval();
}
if (size) dst[0] = '\0';
return NULL;
}