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NetBSD/lib/libc/net/inet_net_ntop.c

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/* $NetBSD: inet_net_ntop.c,v 1.19 2002/11/17 20:49:33 itojun Exp $ */
/*
* Copyright (c) 1996,1999 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static const char rcsid[] = "Id: inet_net_ntop.c,v 1.8 2001/09/27 15:08:36 marka Exp ";
#else
__RCSID("$NetBSD: inet_net_ntop.c,v 1.19 2002/11/17 20:49:33 itojun Exp $");
#endif
#endif
#include "namespace.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#ifdef __weak_alias
__weak_alias(inet_net_ntop,_inet_net_ntop)
#endif
static char * inet_net_ntop_ipv4(const u_char *, int, char *, size_t);
static char * inet_net_ntop_ipv6(const u_char *, int, char *, size_t);
/*
* 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(int af, const void *src, int bits, char *dst, size_t size)
{
_DIAGASSERT(src != NULL);
_DIAGASSERT(dst != NULL);
switch (af) {
case AF_INET:
return (inet_net_ntop_ipv4(src, bits, dst, size));
case AF_INET6:
return (inet_net_ntop_ipv6(src, bits, dst, size));
default:
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
* 0b11110000 in its fourth octet.
* author:
* Paul Vixie (ISC), July 1996
*/
static char *
inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
{
char *odst = dst;
u_int m;
int b;
char *ep;
int advance;
_DIAGASSERT(src != NULL);
_DIAGASSERT(dst != NULL);
ep = dst + size;
if (ep <= dst)
goto emsgsize;
if (bits < 0 || bits > 32) {
errno = EINVAL;
return (NULL);
}
if (bits == 0) {
if ((size_t) (ep - dst) < sizeof "0")
goto emsgsize;
*dst++ = '0';
*dst = '\0';
}
/* Format whole octets. */
for (b = bits / 8; b > 0; b--) {
if ((size_t) (ep - dst) <= sizeof "255.")
goto emsgsize;
advance = snprintf(dst, (size_t)(ep - dst), "%u", *src++);
if (advance <= 0 || advance >= ep - dst)
goto emsgsize;
dst += advance;
if (b > 1) {
if (dst + 1 >= ep)
goto emsgsize;
*dst++ = '.';
*dst = '\0';
}
}
/* Format partial octet. */
b = bits % 8;
if (b > 0) {
if ((size_t) (ep - dst) <= sizeof ".255")
goto emsgsize;
if (dst != odst) {
if (dst + 1 >= ep)
goto emsgsize;
*dst++ = '.';
}
m = ((1 << b) - 1) << (8 - b);
advance = snprintf(dst, (size_t)(ep - dst), "%u", *src & m);
if (advance <= 0 || advance >= ep - dst)
goto emsgsize;
dst += advance;
}
/* Format CIDR /width. */
if ((size_t) (ep - dst) <= sizeof "/32")
goto emsgsize;
advance = snprintf(dst, (size_t)(ep - dst), "/%u", bits);
if (advance <= 0 || advance >= ep - dst)
goto emsgsize;
dst += advance;
return (odst);
emsgsize:
errno = EMSGSIZE;
return (NULL);
}
/*
* static char *
* inet_net_ntop_ipv6(src, bits, fakebits, dst, size)
* convert IPv6 network number from network to presentation format.
* generates CIDR style result always. Picks the shortest representation
* unless the IP is really IPv4.
* always prints specified number of bits (bits).
* 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:
* Vadim Kogan (UCB), June 2001
* Original version (IPv4) by Paul Vixie (ISC), July 1996
*/
static char *
inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
{
size_t bytes;
u_int m;
int b;
int p;
int zero_s, zero_l, tmp_zero_s, tmp_zero_l;
int i;
int is_ipv4 = 0;
u_char inbuf[16];
char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
char *cp;
int words;
u_char *s;
char *ep;
int advance;
_DIAGASSERT(src != NULL);
_DIAGASSERT(dst != NULL);
if (bits < 0 || bits > 128) {
errno = EINVAL;
return (NULL);
}
cp = outbuf;
ep = outbuf + sizeof(outbuf);
if (bits == 0) {
*cp++ = ':';
*cp++ = ':';
*cp = '\0';
} else {
/* Copy src to private buffer. Zero host part. */
bytes = (bits + 7) / 8;
memcpy(inbuf, src, bytes);
memset(inbuf + bytes, 0, 16 - bytes);
b = bits % 8;
if (b != 0) {
m = ~0 << (8 - b);
inbuf[bytes-1] &= m;
}
s = inbuf;
/* how many words need to be displayed in output */
words = (bits + 15) / 16;
if (words == 1)
words = 2;
/* Find the longest substring of zero's */
zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
for (i = 0; i < (words * 2); i += 2) {
if ((s[i] | s[i+1]) == 0) {
if (tmp_zero_l == 0)
tmp_zero_s = i / 2;
tmp_zero_l++;
} else {
if (tmp_zero_l && zero_l < tmp_zero_l) {
zero_s = tmp_zero_s;
zero_l = tmp_zero_l;
tmp_zero_l = 0;
}
}
}
if (tmp_zero_l && zero_l < tmp_zero_l) {
zero_s = tmp_zero_s;
zero_l = tmp_zero_l;
}
if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
is_ipv4 = 1;
/* Format whole words. */
for (p = 0; p < words; p++) {
if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l) {
/* Time to skip some zeros */
if (p == zero_s)
*cp++ = ':';
if (p == words - 1)
*cp++ = ':';
s++;
s++;
continue;
}
if (is_ipv4 && p > 5) {
*cp++ = (p == 6) ? ':' : '.';
advance = snprintf(cp, (size_t)(ep - cp),
"%u", *s++);
if (advance <= 0 || advance >= ep - cp)
goto emsgsize;
cp += advance;
/* we can potentially drop the last octet */
if (p != 7 || bits > 120) {
*cp++ = '.';
advance = snprintf(cp,
(size_t)(ep - cp), "%u", *s++);
if (advance <= 0 || advance >= ep - cp)
goto emsgsize;
cp += advance;
}
} else {
if (cp != outbuf)
*cp++ = ':';
advance = snprintf(cp, (size_t)(ep - cp), "%x",
*s * 256 + s[1]);
if (advance <= 0 || advance >= ep - cp)
goto emsgsize;
cp += advance;
s += 2;
}
}
}
/* Format CIDR /width. */
/* LINTED */
snprintf(cp, ep - cp, "/%u", bits);
if (strlen(outbuf) + 1 > size)
goto emsgsize;
strlcpy(dst, outbuf, size);
return (dst);
emsgsize:
errno = EMSGSIZE;
return (NULL);
}
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