2 * Copyright (C) 2004, 2005, 2007, 2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1996-2001 Internet Software Consortium.
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
20 #if defined(LIBC_SCCS) && !defined(lint)
22 "$Id: inet_ntop.c,v 1.19.128.2 2009/07/18 23:46:53 tbox Exp $";
23 #endif /* LIBC_SCCS and not lint */
32 #include <isc/print.h>
35 #define NS_IN6ADDRSZ 16
38 * WARNING: Don't even consider trying to compile this on a system where
39 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
42 static const char *inet_ntop4(const unsigned char *src
, char *dst
,
46 static const char *inet_ntop6(const unsigned char *src
, char *dst
,
51 * isc_net_ntop(af, src, dst, size)
52 * convert a network format address to presentation format.
54 * pointer to presentation format address (`dst'), or NULL (see errno).
59 isc_net_ntop(int af
, const void *src
, char *dst
, size_t size
)
63 return (inet_ntop4(src
, dst
, size
));
66 return (inet_ntop6(src
, dst
, size
));
76 * inet_ntop4(src, dst, size)
77 * format an IPv4 address
83 * (2) takes a unsigned char* not an in_addr as input
88 inet_ntop4(const unsigned char *src
, char *dst
, size_t size
)
90 static const char *fmt
= "%u.%u.%u.%u";
91 char tmp
[sizeof("255.255.255.255")];
93 if ((size_t)sprintf(tmp
, fmt
, src
[0], src
[1], src
[2], src
[3]) >= size
)
104 * isc_inet_ntop6(src, dst, size)
105 * convert IPv6 binary address into presentation (printable) format
111 inet_ntop6(const unsigned char *src
, char *dst
, size_t size
)
114 * Note that int32_t and int16_t need only be "at least" large enough
115 * to contain a value of the specified size. On some systems, like
116 * Crays, there is no such thing as an integer variable with 16 bits.
117 * Keep this in mind if you think this function should have been coded
118 * to use pointer overlays. All the world's not a VAX.
120 char tmp
[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp
;
121 struct { int base
, len
; } best
, cur
;
122 unsigned int words
[NS_IN6ADDRSZ
/ NS_INT16SZ
];
127 * Copy the input (bytewise) array into a wordwise array.
128 * Find the longest run of 0x00's in src[] for :: shorthanding.
130 memset(words
, '\0', sizeof(words
));
131 for (i
= 0; i
< NS_IN6ADDRSZ
; i
++)
132 words
[i
/ 2] |= (src
[i
] << ((1 - (i
% 2)) << 3));
135 for (i
= 0; i
< (NS_IN6ADDRSZ
/ NS_INT16SZ
); i
++) {
138 cur
.base
= i
, cur
.len
= 1;
142 if (cur
.base
!= -1) {
143 if (best
.base
== -1 || cur
.len
> best
.len
)
149 if (cur
.base
!= -1) {
150 if (best
.base
== -1 || cur
.len
> best
.len
)
153 if (best
.base
!= -1 && best
.len
< 2)
160 for (i
= 0; i
< (NS_IN6ADDRSZ
/ NS_INT16SZ
); i
++) {
161 /* Are we inside the best run of 0x00's? */
162 if (best
.base
!= -1 && i
>= best
.base
&&
163 i
< (best
.base
+ best
.len
)) {
168 /* Are we following an initial run of 0x00s or any real hex? */
171 /* Is this address an encapsulated IPv4? */
172 if (i
== 6 && best
.base
== 0 && (best
.len
== 6 ||
173 (best
.len
== 7 && words
[7] != 0x0001) ||
174 (best
.len
== 5 && words
[5] == 0xffff))) {
175 if (!inet_ntop4(src
+12, tp
,
176 sizeof(tmp
) - (tp
- tmp
)))
181 tp
+= sprintf(tp
, "%x", words
[i
]);
183 /* Was it a trailing run of 0x00's? */
184 if (best
.base
!= -1 && (best
.base
+ best
.len
) ==
185 (NS_IN6ADDRSZ
/ NS_INT16SZ
))
190 * Check for overflow, copy, and we're done.
192 if ((size_t)(tp
- tmp
) > size
) {
199 #endif /* AF_INET6 */