2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996-1999 by Internet Software Consortium.
5 * Permission to use, copy, modify, and 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
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 * $Id: inet_ntop.c,v 1.3.18.2 2005/11/03 23:02:22 marka Exp $
21 #include <sys/param.h>
22 #include <sys/socket.h>
23 #include <sys/systm.h>
25 #include <netinet/in.h>
28 * WARNING: Don't even consider trying to compile this on a system where
29 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
32 static char *inet_ntop4(const u_char
*src
, char *dst
, socklen_t size
);
33 static char *inet_ntop6(const u_char
*src
, char *dst
, socklen_t size
);
36 * inet_ntop(af, src, dst, size)
37 * convert a network format address to presentation format.
39 * pointer to presentation format address (`dst'), or NULL (see errno).
44 inet_ntop(int af
, const void *src
, char *dst
, socklen_t size
)
48 return (inet_ntop4(src
, dst
, size
));
50 return (inet_ntop6(src
, dst
, size
));
58 * inet_ntop4(src, dst, size)
59 * format an IPv4 address
64 * (2) takes a u_char* not an in_addr as input
69 inet_ntop4(const u_char
*src
, char *dst
, socklen_t size
)
71 static const char fmt
[] = "%u.%u.%u.%u";
72 char tmp
[sizeof "255.255.255.255"];
75 l
= ksnprintf(tmp
, sizeof(tmp
), fmt
, src
[0], src
[1], src
[2], src
[3]);
76 if (l
<= 0 || (socklen_t
) l
>= size
) {
79 strlcpy(dst
, tmp
, size
);
84 * inet_ntop6(src, dst, size)
85 * convert IPv6 binary address into presentation (printable) format
90 inet_ntop6(const u_char
*src
, char *dst
, socklen_t size
)
93 * Note that int32_t and int16_t need only be "at least" large enough
94 * to contain a value of the specified size. On some systems, like
95 * Crays, there is no such thing as an integer variable with 16 bits.
96 * Keep this in mind if you think this function should have been coded
97 * to use pointer overlays. All the world's not a VAX.
99 char tmp
[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp
;
100 struct { int base
, len
; } best
, cur
;
101 #define NS_IN6ADDRSZ 16
103 u_int words
[NS_IN6ADDRSZ
/ NS_INT16SZ
];
108 * Copy the input (bytewise) array into a wordwise array.
109 * Find the longest run of 0x00's in src[] for :: shorthanding.
111 memset(words
, '\0', sizeof words
);
112 for (i
= 0; i
< NS_IN6ADDRSZ
; i
++)
113 words
[i
/ 2] |= (src
[i
] << ((1 - (i
% 2)) << 3));
118 for (i
= 0; i
< (NS_IN6ADDRSZ
/ NS_INT16SZ
); i
++) {
121 cur
.base
= i
, cur
.len
= 1;
125 if (cur
.base
!= -1) {
126 if (best
.base
== -1 || cur
.len
> best
.len
)
132 if (cur
.base
!= -1) {
133 if (best
.base
== -1 || cur
.len
> best
.len
)
136 if (best
.base
!= -1 && best
.len
< 2)
143 for (i
= 0; i
< (NS_IN6ADDRSZ
/ NS_INT16SZ
); i
++) {
144 /* Are we inside the best run of 0x00's? */
145 if (best
.base
!= -1 && i
>= best
.base
&&
146 i
< (best
.base
+ best
.len
)) {
151 /* Are we following an initial run of 0x00s or any real hex? */
154 /* Is this address an encapsulated IPv4? */
155 if (i
== 6 && best
.base
== 0 && (best
.len
== 6 ||
156 (best
.len
== 7 && words
[7] != 0x0001) ||
157 (best
.len
== 5 && words
[5] == 0xffff))) {
158 if (!inet_ntop4(src
+12, tp
, sizeof tmp
- (tp
- tmp
)))
163 tp
+= ksprintf(tp
, "%x", words
[i
]);
165 /* Was it a trailing run of 0x00's? */
166 if (best
.base
!= -1 && (best
.base
+ best
.len
) ==
167 (NS_IN6ADDRSZ
/ NS_INT16SZ
))
172 * Check for overflow, copy, and we're done.
174 if ((socklen_t
)(tp
- tmp
) > size
) {