source: branches/samba-3.3.x/source/lib/replace/inet_ntop.c

Last change on this file was 206, checked in by Herwig Bauernfeind, 16 years ago

Import Samba 3.3 branch at 3.0.0 level (psmedley's port)

File size: 4.9 KB
Line 
1/*
2 * Copyright (C) 1996-2001 Internet Software Consortium.
3 *
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.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
9 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
10 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
11 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
13 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
14 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
15 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18
19#include "replace.h"
20#include "system/network.h"
21
22#define NS_INT16SZ 2
23#define NS_IN6ADDRSZ 16
24
25/*
26 * WARNING: Don't even consider trying to compile this on a system where
27 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
28 */
29
30static const char *inet_ntop4(const unsigned char *src, char *dst,
31 socklen_t size);
32
33#ifdef AF_INET6
34static const char *inet_ntop6(const unsigned char *src, char *dst,
35 socklen_t size);
36#endif
37
38/* char *
39 * isc_net_ntop(af, src, dst, size)
40 * convert a network format address to presentation format.
41 * return:
42 * pointer to presentation format address (`dst'), or NULL (see errno).
43 * author:
44 * Paul Vixie, 1996.
45 */
46const char *
47rep_inet_ntop(int af, const void *src, char *dst, socklen_t size)
48{
49 switch (af) {
50 case AF_INET:
51 return (inet_ntop4(src, dst, size));
52#ifdef AF_INET6
53 case AF_INET6:
54 return (inet_ntop6(src, dst, size));
55#endif
56 default:
57 errno = EAFNOSUPPORT;
58 return (NULL);
59 }
60 /* NOTREACHED */
61}
62
63/* const char *
64 * inet_ntop4(src, dst, size)
65 * format an IPv4 address
66 * return:
67 * `dst' (as a const)
68 * notes:
69 * (1) uses no statics
70 * (2) takes a unsigned char* not an in_addr as input
71 * author:
72 * Paul Vixie, 1996.
73 */
74static const char *
75inet_ntop4(const unsigned char *src, char *dst, socklen_t size)
76{
77 static const char *fmt = "%u.%u.%u.%u";
78 char tmp[sizeof "255.255.255.255"];
79 size_t len;
80
81 len = snprintf(tmp, sizeof tmp, fmt, src[0], src[1], src[2], src[3]);
82 if (len >= size) {
83 errno = ENOSPC;
84 return (NULL);
85 }
86 memcpy(dst, tmp, len + 1);
87
88 return (dst);
89}
90
91/* const char *
92 * isc_inet_ntop6(src, dst, size)
93 * convert IPv6 binary address into presentation (printable) format
94 * author:
95 * Paul Vixie, 1996.
96 */
97#ifdef AF_INET6
98static const char *
99inet_ntop6(const unsigned char *src, char *dst, socklen_t size)
100{
101 /*
102 * Note that int32_t and int16_t need only be "at least" large enough
103 * to contain a value of the specified size. On some systems, like
104 * Crays, there is no such thing as an integer variable with 16 bits.
105 * Keep this in mind if you think this function should have been coded
106 * to use pointer overlays. All the world's not a VAX.
107 */
108 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
109 struct { int base, len; } best, cur;
110 unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
111 int i, inc;
112
113 /*
114 * Preprocess:
115 * Copy the input (bytewise) array into a wordwise array.
116 * Find the longest run of 0x00's in src[] for :: shorthanding.
117 */
118 memset(words, '\0', sizeof words);
119 for (i = 0; i < NS_IN6ADDRSZ; i++)
120 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
121 best.base = -1;
122 best.len = 0;
123 cur.base = -1;
124 cur.len = 0;
125 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
126 if (words[i] == 0) {
127 if (cur.base == -1)
128 cur.base = i, cur.len = 1;
129 else
130 cur.len++;
131 } else {
132 if (cur.base != -1) {
133 if (best.base == -1 || cur.len > best.len)
134 best = cur;
135 cur.base = -1;
136 }
137 }
138 }
139 if (cur.base != -1) {
140 if (best.base == -1 || cur.len > best.len)
141 best = cur;
142 }
143 if (best.base != -1 && best.len < 2)
144 best.base = -1;
145
146 /*
147 * Format the result.
148 */
149 tp = tmp;
150 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
151 /* Are we inside the best run of 0x00's? */
152 if (best.base != -1 && i >= best.base &&
153 i < (best.base + best.len)) {
154 if (i == best.base)
155 *tp++ = ':';
156 continue;
157 }
158 /* Are we following an initial run of 0x00s or any real hex? */
159 if (i != 0)
160 *tp++ = ':';
161 /* Is this address an encapsulated IPv4? */
162 if (i == 6 && best.base == 0 &&
163 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
164 if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
165 return (NULL);
166 tp += strlen(tp);
167 break;
168 }
169 inc = snprintf(tp, 5, "%x", words[i]);
170 if (inc >= 5) {
171 abort();
172 }
173 tp += inc;
174 }
175 /* Was it a trailing run of 0x00's? */
176 if (best.base != -1 && (best.base + best.len) ==
177 (NS_IN6ADDRSZ / NS_INT16SZ))
178 *tp++ = ':';
179 *tp++ = '\0';
180
181 /*
182 * Check for overflow, copy, and we're done.
183 */
184 if ((size_t)(tp - tmp) > size) {
185 errno = ENOSPC;
186 return (NULL);
187 }
188 memcpy(dst, tmp, tp - tmp);
189 return (dst);
190}
191#endif /* AF_INET6 */
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