1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC 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.
*/
/*! \file */
#if defined(LIBC_SCCS) && !defined(lint)
static char rcsid[] =
"$Id: inet_ntop.c,v 1.7 2019/12/17 01:46:34 sthen Exp $";
#endif /* LIBC_SCCS and not lint */
#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <isc/net.h>
#include <isc/print.h>
#include <isc/string.h>
#include <isc/util.h>
#define NS_INT16SZ 2
#define NS_IN6ADDRSZ 16
/*
* WARNING: Don't even consider trying to compile this on a system where
* sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
*/
static const char *inet_ntop4(const unsigned char *src, char *dst,
size_t size);
#ifdef AF_INET6
static const char *inet_ntop6(const unsigned char *src, char *dst,
size_t size);
#endif
/*! char *
* isc_net_ntop(af, src, dst, size)
* convert a network format address to presentation format.
* \return
* pointer to presentation format address (`dst'), or NULL (see errno).
* \author
* Paul Vixie, 1996.
*/
const char *
isc_net_ntop(int af, const void *src, char *dst, size_t size)
{
switch (af) {
case AF_INET:
return (inet_ntop4(src, dst, size));
#ifdef AF_INET6
case AF_INET6:
return (inet_ntop6(src, dst, size));
#endif
default:
errno = EAFNOSUPPORT;
return (NULL);
}
/* NOTREACHED */
}
/*! const char *
* inet_ntop4(src, dst, size)
* format an IPv4 address
* \return
* `dst' (as a const)
* \note
* (1) uses no statics
* \note
* (2) takes a unsigned char* not an in_addr as input
* \author
* Paul Vixie, 1996.
*/
static const char *
inet_ntop4(const unsigned char *src, char *dst, size_t size)
{
static const char *fmt = "%u.%u.%u.%u";
char tmp[sizeof("255.255.255.255")];
int n;
n = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]);
if (n < 0 || (size_t)n >= size) {
errno = ENOSPC;
return (NULL);
}
strlcpy(dst, tmp, size);
return (dst);
}
/*! const char *
* isc_inet_ntop6(src, dst, size)
* convert IPv6 binary address into presentation (printable) format
* \author
* Paul Vixie, 1996.
*/
#ifdef AF_INET6
static const char *
inet_ntop6(const unsigned char *src, char *dst, size_t size)
{
/*
* Note that int32_t and int16_t need only be "at least" large enough
* to contain a value of the specified size. On some systems, like
* Crays, there is no such thing as an integer variable with 16 bits.
* Keep this in mind if you think this function should have been coded
* to use pointer overlays. All the world's not a VAX.
*/
char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp;
struct { int base, len; } best, cur;
unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
int i;
/*
* Preprocess:
* Copy the input (bytewise) array into a wordwise array.
* Find the longest run of 0x00's in src[] for :: shorthanding.
*/
memset(words, '\0', sizeof(words));
for (i = 0; i < NS_IN6ADDRSZ; i++)
words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
best.base = -1;
best.len = 0; /* silence compiler */
cur.base = -1;
cur.len = 0; /* silence compiler */
for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
if (words[i] == 0) {
if (cur.base == -1)
cur.base = i, cur.len = 1;
else
cur.len++;
} else {
if (cur.base != -1) {
if (best.base == -1 || cur.len > best.len)
best = cur;
cur.base = -1;
}
}
}
if (cur.base != -1) {
if (best.base == -1 || cur.len > best.len)
best = cur;
}
if (best.base != -1 && best.len < 2)
best.base = -1;
/*
* Format the result.
*/
tp = tmp;
for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
/* Are we inside the best run of 0x00's? */
if (best.base != -1 && i >= best.base &&
i < (best.base + best.len)) {
if (i == best.base)
*tp++ = ':';
continue;
}
/* Are we following an initial run of 0x00s or any real hex? */
if (i != 0)
*tp++ = ':';
/* Is this address an encapsulated IPv4? */
if (i == 6 && best.base == 0 && (best.len == 6 ||
(best.len == 7 && words[7] != 0x0001) ||
(best.len == 5 && words[5] == 0xffff))) {
if (!inet_ntop4(src+12, tp,
sizeof(tmp) - (tp - tmp)))
return (NULL);
tp += strlen(tp);
break;
}
INSIST((size_t)(tp - tmp) < sizeof(tmp));
tp += snprintf(tp, sizeof(tmp) - (tp - tmp), "%x", words[i]);
}
/* Was it a trailing run of 0x00's? */
if (best.base != -1 && (best.base + best.len) ==
(NS_IN6ADDRSZ / NS_INT16SZ))
*tp++ = ':';
*tp++ = '\0';
/*
* Check for overflow, copy, and we're done.
*/
if ((size_t)(tp - tmp) > size) {
errno = ENOSPC;
return (NULL);
}
strlcpy(dst, tmp, size);
return (dst);
}
#endif /* AF_INET6 */
|
