inet_ntop.c revision 55682 
1/*
2 * Copyright (c) 1999 Kungliga Tekniska H�gskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifdef HAVE_CONFIG_H
35#include <config.h>
36RCSID("$Id: inet_ntop.c,v 1.3 1999/12/02 16:58:47 joda Exp $");
37#endif
38
39#include <errno.h>
40#ifdef HAVE_SYS_TYPES_H
41#include <sys/types.h>
42#endif
43#ifdef HAVE_SYS_SOCKET_H
44#include <sys/socket.h>
45#endif
46#ifdef HAVE_NETINET_IN_H
47#include <netinet/in.h>
48#endif
49#ifdef HAVE_NETINET_IN6_H
50#include <netinet/in6.h>
51#endif
52#ifdef HAVE_NETINET6_IN6_H
53#include <netinet6/in6.h>
54#endif
55
56#include <roken.h>
57
58/*
59 *
60 */
61
62static const char *
63inet_ntop_v4 (const void *src, char *dst, size_t size)
64{
65    const char digits[] = "0123456789";
66    int i;
67    struct in_addr *addr = (struct in_addr *)src;
68    u_long a = ntohl(addr->s_addr);
69    const char *orig_dst = dst;
70
71    if (size < INET_ADDRSTRLEN) {
72	errno = ENOSPC;
73	return NULL;
74    }
75    for (i = 0; i < 4; ++i) {
76	int n = (a >> (24 - i * 8)) & 0xFF;
77	int non_zerop = 0;
78
79	if (non_zerop || n / 100 > 0) {
80	    *dst++ = digits[n / 100];
81	    n %= 100;
82	    non_zerop = 1;
83	}
84	if (non_zerop || n / 10 > 0) {
85	    *dst++ = digits[n / 10];
86	    n %= 10;
87	    non_zerop = 1;
88	}
89	*dst++ = digits[n];
90	if (i != 3)
91	    *dst++ = '.';
92    }
93    *dst++ = '\0';
94    return orig_dst;
95}
96
97#ifdef HAVE_IPV6
98static const char *
99inet_ntop_v6 (const void *src, char *dst, size_t size)
100{
101    const char xdigits[] = "0123456789abcdef";
102    int i;
103    const struct in6_addr *addr = (struct in6_addr *)src;
104    const u_char *ptr = addr->s6_addr;
105    const char *orig_dst = dst;
106
107    if (size < INET6_ADDRSTRLEN) {
108	errno = ENOSPC;
109	return NULL;
110    }
111    for (i = 0; i < 8; ++i) {
112	int non_zerop = 1;
113
114	if (non_zerop || (ptr[0] >> 4)) {
115	    *dst++ = xdigits[ptr[0] >> 4];
116	    non_zerop = 1;
117	}
118	if (non_zerop || (ptr[0] & 0x0F)) {
119	    *dst++ = xdigits[ptr[0] & 0x0F];
120	    non_zerop = 1;
121	}
122	if (non_zerop || (ptr[1] >> 4)) {
123	    *dst++ = xdigits[ptr[1] >> 4];
124	    non_zerop = 1;
125	}
126	if (non_zerop || (ptr[1] & 0x0F)) {
127	    *dst++ = xdigits[ptr[1] & 0x0F];
128	    non_zerop = 1;
129	}
130	if (i != 7)
131	    *dst++ = ':';
132	ptr += 2;
133    }
134    *dst++ = '\0';
135    return orig_dst;
136}
137#endif /* HAVE_IPV6 */
138
139const char *
140inet_ntop(int af, const void *src, char *dst, size_t size)
141{
142    switch (af) {
143    case AF_INET :
144	return inet_ntop_v4 (src, dst, size);
145#ifdef HAVE_IPV6
146    case AF_INET6 :
147	return inet_ntop_v6 (src, dst, size);
148#endif
149    default :
150	errno = EAFNOSUPPORT;
151	return NULL;
152    }
153}
154