2 * Copyright (c) 1996-1999 by Internet Software Consortium.
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <netinet/in.h>
22 #include <arpa/inet.h>
30 #define NS_IN6ADDRSZ 16
37 * WARNING: Don't even consider trying to compile this on a system where
38 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
42 * inet_ntop4(src, dst, size)
43 * format an IPv4 address
48 * (2) takes a u_char* not an in_addr as input
53 inet_ntop4(src
, dst
, size
)
58 static const char fmt
[] = "%u.%u.%u.%u";
59 char tmp
[sizeof "255.255.255.255"];
62 nprinted
= snprintf(tmp
, sizeof(tmp
), fmt
, src
[0], src
[1], src
[2], src
[3]);
64 return (NULL
); /* we assume "errno" was set by "snprintf()" */
65 if ((size_t)nprinted
> size
) {
75 * inet_ntop6(src, dst, size)
76 * convert IPv6 binary address into presentation (printable) format
81 inet_ntop6(src
, dst
, size
)
87 * Note that int32_t and int16_t need only be "at least" large enough
88 * to contain a value of the specified size. On some systems, like
89 * Crays, there is no such thing as an integer variable with 16 bits.
90 * Keep this in mind if you think this function should have been coded
91 * to use pointer overlays. All the world's not a VAX.
93 char tmp
[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp
;
94 struct { int base
, len
; } best
, cur
;
95 unsigned int words
[NS_IN6ADDRSZ
/ NS_INT16SZ
];
100 * Copy the input (bytewise) array into a wordwise array.
101 * Find the longest run of 0x00's in src[] for :: shorthanding.
103 memset(words
, '\0', sizeof words
);
104 for (i
= 0; i
< NS_IN6ADDRSZ
; i
++)
105 words
[i
/ 2] |= (src
[i
] << ((1 - (i
% 2)) << 3));
108 for (i
= 0; i
< (NS_IN6ADDRSZ
/ NS_INT16SZ
); i
++) {
111 cur
.base
= i
, cur
.len
= 1;
115 if (cur
.base
!= -1) {
116 if (best
.base
== -1 || cur
.len
> best
.len
)
122 if (cur
.base
!= -1) {
123 if (best
.base
== -1 || cur
.len
> best
.len
)
126 if (best
.base
!= -1 && best
.len
< 2)
133 for (i
= 0; i
< (NS_IN6ADDRSZ
/ NS_INT16SZ
); i
++) {
134 /* Are we inside the best run of 0x00's? */
135 if (best
.base
!= -1 && i
>= best
.base
&&
136 i
< (best
.base
+ best
.len
)) {
141 /* Are we following an initial run of 0x00s or any real hex? */
144 /* Is this address an encapsulated IPv4? */
145 if (i
== 6 && best
.base
== 0 &&
146 (best
.len
== 6 || (best
.len
== 5 && words
[5] == 0xffff))) {
147 if (!inet_ntop4(src
+12, tp
, sizeof tmp
- (tp
- tmp
)))
152 tp
+= snprintf(tp
, sizeof tmp
- (tp
- tmp
), "%x", words
[i
]);
154 /* Was it a trailing run of 0x00's? */
155 if (best
.base
!= -1 && (best
.base
+ best
.len
) ==
156 (NS_IN6ADDRSZ
/ NS_INT16SZ
))
161 * Check for overflow, copy, and we're done.
163 if ((size_t)(tp
- tmp
) > size
) {
173 * inet_ntop(af, src, dst, size)
174 * convert a network format address to presentation format.
176 * pointer to presentation format address (`dst'), or NULL (see errno).
181 inet_ntop(af
, src
, dst
, size
)
189 return (inet_ntop4(src
, dst
, size
));
192 return (inet_ntop6(src
, dst
, size
));
195 errno
= EAFNOSUPPORT
;