1 /* Copyright (c) 1996 by Internet Software Consortium.
3 * Permission to use, copy, modify, and distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
7 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
8 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
9 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
10 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
11 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
12 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
13 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
17 #if defined(LIBC_SCCS) && !defined(lint)
18 static char rcsid
[] = "$Id$";
19 #endif /* LIBC_SCCS and not lint */
21 #include <sys/param.h>
22 #include <sys/types.h>
23 #include <sys/socket.h>
24 #include <netinet/in.h>
25 #include <arpa/inet.h>
26 #include <arpa/nameser.h>
30 #include "../conf/portability.h"
33 # define SPRINTF(x) strlen(sprintf/**/x)
35 # define SPRINTF(x) ((size_t)sprintf x)
39 * WARNING: Don't even consider trying to compile this on a system where
40 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
43 static const char *inet_ntop4
__P((const u_char
*src
, char *dst
, size_t size
));
44 static const char *inet_ntop6
__P((const u_char
*src
, char *dst
, size_t size
));
47 * inet_ntop(af, src, dst, size)
48 * convert a network format address to presentation format.
50 * pointer to presentation format address (`dst'), or NULL (see errno).
55 inet_ntop(af
, src
, dst
, size
)
63 return (inet_ntop4(src
, dst
, size
));
65 return (inet_ntop6(src
, dst
, size
));
67 __set_errno (EAFNOSUPPORT
);
74 * inet_ntop4(src, dst, size)
75 * format an IPv4 address, more or less like inet_ntoa()
80 * (2) takes a u_char* not an in_addr as input
85 inet_ntop4(src
, dst
, size
)
90 static const char fmt
[] = "%u.%u.%u.%u";
91 char tmp
[sizeof "255.255.255.255"];
93 if (SPRINTF((tmp
, fmt
, src
[0], src
[1], src
[2], src
[3])) > size
) {
102 * inet_ntop6(src, dst, size)
103 * convert IPv6 binary address into presentation (printable) format
108 inet_ntop6(src
, dst
, 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 u_int words
[IN6ADDRSZ
/ 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
< IN6ADDRSZ
; i
++)
132 words
[i
/ 2] |= (src
[i
] << ((1 - (i
% 2)) << 3));
135 for (i
= 0; i
< (IN6ADDRSZ
/ 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
< (IN6ADDRSZ
/ 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 &&
173 (best
.len
== 6 || (best
.len
== 5 && words
[5] == 0xffff))) {
174 if (!inet_ntop4(src
+12, tp
, sizeof tmp
- (tp
- tmp
)))
179 tp
+= SPRINTF((tp
, "%x", words
[i
]));
181 /* Was it a trailing run of 0x00's? */
182 if (best
.base
!= -1 && (best
.base
+ best
.len
) == (IN6ADDRSZ
/ INT16SZ
))
187 * Check for overflow, copy, and we're done.
189 if ((size_t)(tp
- tmp
) > size
) {
190 __set_errno (ENOSPC
);