inet_ntop.c revision 178825 
1/*
2 * Copyright (c) 1999 - 2001 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 21005 2007-06-08 01:54:35Z lha $");
37#endif
38
39#include "roken.h"
40
41/*
42 *
43 */
44
45static const char *
46inet_ntop_v4 (const void *src, char *dst, size_t size)
47{
48    const char digits[] = "0123456789";
49    int i;
50    struct in_addr *addr = (struct in_addr *)src;
51    u_long a = ntohl(addr->s_addr);
52    const char *orig_dst = dst;
53
54    if (size < INET_ADDRSTRLEN) {
55	errno = ENOSPC;
56	return NULL;
57    }
58    for (i = 0; i < 4; ++i) {
59	int n = (a >> (24 - i * 8)) & 0xFF;
60	int non_zerop = 0;
61
62	if (non_zerop || n / 100 > 0) {
63	    *dst++ = digits[n / 100];
64	    n %= 100;
65	    non_zerop = 1;
66	}
67	if (non_zerop || n / 10 > 0) {
68	    *dst++ = digits[n / 10];
69	    n %= 10;
70	    non_zerop = 1;
71	}
72	*dst++ = digits[n];
73	if (i != 3)
74	    *dst++ = '.';
75    }
76    *dst++ = '\0';
77    return orig_dst;
78}
79
80#ifdef HAVE_IPV6
81static const char *
82inet_ntop_v6 (const void *src, char *dst, size_t size)
83{
84    const char xdigits[] = "0123456789abcdef";
85    int i;
86    const struct in6_addr *addr = (struct in6_addr *)src;
87    const u_char *ptr = addr->s6_addr;
88    const char *orig_dst = dst;
89
90    if (size < INET6_ADDRSTRLEN) {
91	errno = ENOSPC;
92	return NULL;
93    }
94    for (i = 0; i < 8; ++i) {
95	int non_zerop = 0;
96
97	if (non_zerop || (ptr[0] >> 4)) {
98	    *dst++ = xdigits[ptr[0] >> 4];
99	    non_zerop = 1;
100	}
101	if (non_zerop || (ptr[0] & 0x0F)) {
102	    *dst++ = xdigits[ptr[0] & 0x0F];
103	    non_zerop = 1;
104	}
105	if (non_zerop || (ptr[1] >> 4)) {
106	    *dst++ = xdigits[ptr[1] >> 4];
107	    non_zerop = 1;
108	}
109	*dst++ = xdigits[ptr[1] & 0x0F];
110	if (i != 7)
111	    *dst++ = ':';
112	ptr += 2;
113    }
114    *dst++ = '\0';
115    return orig_dst;
116}
117#endif /* HAVE_IPV6 */
118
119const char * ROKEN_LIB_FUNCTION
120inet_ntop(int af, const void *src, char *dst, size_t size)
121{
122    switch (af) {
123    case AF_INET :
124	return inet_ntop_v4 (src, dst, size);
125#ifdef HAVE_IPV6
126    case AF_INET6 :
127	return inet_ntop_v6 (src, dst, size);
128#endif
129    default :
130	errno = EAFNOSUPPORT;
131	return NULL;
132    }
133}
134