1: /*
2: * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
3: * Copyright (C) 1996-2001 Internet Software Consortium.
4: *
5: * Permission to use, copy, modify, and/or 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.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10: * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11: * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12: * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13: * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14: * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15: * PERFORMANCE OF THIS SOFTWARE.
16: */
17:
18: /*! \file */
19:
20: #if defined(LIBC_SCCS) && !defined(lint)
21: static char rcsid[] =
22: "$Id: inet_ntop.c,v 1.1.1.1 2012/05/29 12:08:38 misho Exp $";
23: #endif /* LIBC_SCCS and not lint */
24:
25: #include <config.h>
26:
27: #include <errno.h>
28: #include <stdio.h>
29: #include <string.h>
30:
31: #include <isc/net.h>
32: #include <isc/print.h>
33:
34: #include "ntp_sprintf.h" /* NTP local change, helps SunOS 4 */
35:
36: #define NS_INT16SZ 2
37: #define NS_IN6ADDRSZ 16
38:
39: /*
40: * WARNING: Don't even consider trying to compile this on a system where
41: * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
42: */
43:
44: static const char *inet_ntop4(const unsigned char *src, char *dst,
45: size_t size);
46:
47: #ifdef AF_INET6
48: static const char *inet_ntop6(const unsigned char *src, char *dst,
49: size_t size);
50: #endif
51:
52: /*! char *
53: * isc_net_ntop(af, src, dst, size)
54: * convert a network format address to presentation format.
55: * \return
56: * pointer to presentation format address (`dst'), or NULL (see errno).
57: * \author
58: * Paul Vixie, 1996.
59: */
60: const char *
61: isc_net_ntop(int af, const void *src, char *dst, size_t size)
62: {
63: switch (af) {
64: case AF_INET:
65: return (inet_ntop4(src, dst, size));
66: #ifdef AF_INET6
67: case AF_INET6:
68: return (inet_ntop6(src, dst, size));
69: #endif
70: default:
71: errno = EAFNOSUPPORT;
72: return (NULL);
73: }
74: /* NOTREACHED */
75: }
76:
77: /*! const char *
78: * inet_ntop4(src, dst, size)
79: * format an IPv4 address
80: * \return
81: * `dst' (as a const)
82: * \note
83: * (1) uses no statics
84: * \note
85: * (2) takes a unsigned char* not an in_addr as input
86: * \author
87: * Paul Vixie, 1996.
88: */
89: static const char *
90: inet_ntop4(const unsigned char *src, char *dst, size_t size)
91: {
92: static const char *fmt = "%u.%u.%u.%u";
93: char tmp[sizeof("255.255.255.255")];
94:
95: /* NTP local change to use SNPRINTF() macro for SunOS4 compat */
96: if (SNPRINTF((tmp, sizeof(tmp), fmt, src[0], src[1], src[2],
97: src[3])) >= size)
98: {
99: errno = ENOSPC;
100: return (NULL);
101: }
102: strcpy(dst, tmp);
103:
104: return (dst);
105: }
106:
107: /*! const char *
108: * isc_inet_ntop6(src, dst, size)
109: * convert IPv6 binary address into presentation (printable) format
110: * \author
111: * Paul Vixie, 1996.
112: */
113: #ifdef AF_INET6
114: static const char *
115: inet_ntop6(const unsigned char *src, char *dst, size_t size)
116: {
117: /*
118: * Note that int32_t and int16_t need only be "at least" large enough
119: * to contain a value of the specified size. On some systems, like
120: * Crays, there is no such thing as an integer variable with 16 bits.
121: * Keep this in mind if you think this function should have been coded
122: * to use pointer overlays. All the world's not a VAX.
123: */
124: char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp;
125: struct { int base, len; } best, cur;
126: unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
127: int i;
128:
129: /*
130: * Preprocess:
131: * Copy the input (bytewise) array into a wordwise array.
132: * Find the longest run of 0x00's in src[] for :: shorthanding.
133: */
134: memset(words, '\0', sizeof(words));
135: for (i = 0; i < NS_IN6ADDRSZ; i++)
136: words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
137: best.base = -1;
138: cur.base = -1;
139: for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
140: if (words[i] == 0) {
141: if (cur.base == -1)
142: cur.base = i, cur.len = 1;
143: else
144: cur.len++;
145: } else {
146: if (cur.base != -1) {
147: if (best.base == -1 || cur.len > best.len)
148: best = cur;
149: cur.base = -1;
150: }
151: }
152: }
153: if (cur.base != -1) {
154: if (best.base == -1 || cur.len > best.len)
155: best = cur;
156: }
157: if (best.base != -1 && best.len < 2)
158: best.base = -1;
159:
160: /*
161: * Format the result.
162: */
163: tp = tmp;
164: for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
165: /* Are we inside the best run of 0x00's? */
166: if (best.base != -1 && i >= best.base &&
167: i < (best.base + best.len)) {
168: if (i == best.base)
169: *tp++ = ':';
170: continue;
171: }
172: /* Are we following an initial run of 0x00s or any real hex? */
173: if (i != 0)
174: *tp++ = ':';
175: /* Is this address an encapsulated IPv4? */
176: if (i == 6 && best.base == 0 &&
177: (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
178: if (!inet_ntop4(src+12, tp,
179: sizeof(tmp) - (tp - tmp)))
180: return (NULL);
181: tp += strlen(tp);
182: break;
183: }
184: tp += SPRINTF((tp, "%x", words[i])); /* NTP local change */
185: }
186: /* Was it a trailing run of 0x00's? */
187: if (best.base != -1 && (best.base + best.len) ==
188: (NS_IN6ADDRSZ / NS_INT16SZ))
189: *tp++ = ':';
190: *tp++ = '\0';
191:
192: /*
193: * Check for overflow, copy, and we're done.
194: */
195: if ((size_t)(tp - tmp) > size) {
196: errno = ENOSPC;
197: return (NULL);
198: }
199: strcpy(dst, tmp);
200: return (dst);
201: }
202: #endif /* AF_INET6 */
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