glibc/resolv/inet_net_ntop.c

140 lines
3.2 KiB
C

/*
* Copyright (c) 1996 by Internet Software Consortium.
*
* 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "$Id$";
#endif
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#ifdef SPRINTF_CHAR
# define SPRINTF(x) strlen(sprintf/**/x)
#else
# define SPRINTF(x) ((size_t)sprintf x)
#endif
static char * inet_net_ntop_ipv4 __P((const u_char *src, int bits,
char *dst, size_t size));
/*
* char *
* inet_net_ntop(af, src, bits, dst, size)
* convert network number from network to presentation format.
* generates CIDR style result always.
* return:
* pointer to dst, or NULL if an error occurred (check errno).
* author:
* Paul Vixie (ISC), July 1996
*/
char *
inet_net_ntop(af, src, bits, dst, size)
int af;
const void *src;
int bits;
char *dst;
size_t size;
{
switch (af) {
case AF_INET:
return (inet_net_ntop_ipv4(src, bits, dst, size));
default:
__set_errno (EAFNOSUPPORT);
return (NULL);
}
}
/*
* static char *
* inet_net_ntop_ipv4(src, bits, dst, size)
* convert IPv4 network number from network to presentation format.
* generates CIDR style result always.
* return:
* pointer to dst, or NULL if an error occurred (check errno).
* note:
* network byte order assumed. this means 192.5.5.240/28 has
* 0x11110000 in its fourth octet.
* author:
* Paul Vixie (ISC), July 1996
*/
static char *
inet_net_ntop_ipv4(src, bits, dst, size)
const u_char *src;
int bits;
char *dst;
size_t size;
{
char *odst = dst;
char *t;
u_int m;
int b;
if (bits < 0 || bits > 32) {
__set_errno (EINVAL);
return (NULL);
}
if (bits == 0) {
if (size < sizeof "0")
goto emsgsize;
*dst++ = '0';
*dst = '\0';
}
/* Format whole octets. */
for (b = bits / 8; b > 0; b--) {
if (size < sizeof "255.")
goto emsgsize;
t = dst;
dst += SPRINTF((dst, "%u", *src++));
if (b > 1) {
*dst++ = '.';
*dst = '\0';
}
size -= (size_t)(dst - t);
}
/* Format partial octet. */
b = bits % 8;
if (b > 0) {
if (size < sizeof ".255")
goto emsgsize;
t = dst;
if (dst != odst)
*dst++ = '.';
m = ((1 << b) - 1) << (8 - b);
dst += SPRINTF((dst, "%u", *src & m));
size -= (size_t)(dst - t);
}
/* Format CIDR /width. */
if (size < sizeof "/32")
goto emsgsize;
dst += SPRINTF((dst, "/%u", bits));
return (odst);
emsgsize:
__set_errno (EMSGSIZE);
return (NULL);
}