xref: /freebsd/crypto/heimdal/lib/roken/inet_ntop.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright (c) 1999 - 2001 Kungliga Tekniska Högskolan
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 #include <config.h>
35 
36 #include "roken.h"
37 
38 /*
39  *
40  */
41 
42 static const char *
43 inet_ntop_v4 (const void *src, char *dst, size_t size)
44 {
45     const char digits[] = "0123456789";
46     int i;
47     struct in_addr *addr = (struct in_addr *)src;
48     u_long a = ntohl(addr->s_addr);
49     const char *orig_dst = dst;
50 
51     if (size < INET_ADDRSTRLEN) {
52 	errno = ENOSPC;
53 	return NULL;
54     }
55     for (i = 0; i < 4; ++i) {
56 	int n = (a >> (24 - i * 8)) & 0xFF;
57 	int non_zerop = 0;
58 
59 	if (non_zerop || n / 100 > 0) {
60 	    *dst++ = digits[n / 100];
61 	    n %= 100;
62 	    non_zerop = 1;
63 	}
64 	if (non_zerop || n / 10 > 0) {
65 	    *dst++ = digits[n / 10];
66 	    n %= 10;
67 	    non_zerop = 1;
68 	}
69 	*dst++ = digits[n];
70 	if (i != 3)
71 	    *dst++ = '.';
72     }
73     *dst++ = '\0';
74     return orig_dst;
75 }
76 
77 #ifdef HAVE_IPV6
78 static const char *
79 inet_ntop_v6 (const void *src, char *dst, size_t size)
80 {
81     const char xdigits[] = "0123456789abcdef";
82     int i;
83     const struct in6_addr *addr = (struct in6_addr *)src;
84     const u_char *ptr = addr->s6_addr;
85     const char *orig_dst = dst;
86     int compressed = 0;
87 
88     if (size < INET6_ADDRSTRLEN) {
89 	errno = ENOSPC;
90 	return NULL;
91     }
92     for (i = 0; i < 8; ++i) {
93 	int non_zerop = 0;
94 
95         if (compressed == 0 &&
96             ptr[0] == 0 && ptr[1] == 0 &&
97             i <= 5 &&
98             ptr[2] == 0 && ptr[3] == 0 &&
99             ptr[4] == 0 && ptr[5] == 0) {
100 
101             compressed = 1;
102 
103             if (i == 0)
104                 *dst++ = ':';
105             *dst++ = ':';
106 
107             for (ptr += 6, i += 3;
108                  i < 8 && ptr[0] == 0 && ptr[1] == 0;
109                  ++i, ptr += 2);
110 
111             if (i >= 8)
112                 break;
113         }
114 
115 	if (non_zerop || (ptr[0] >> 4)) {
116 	    *dst++ = xdigits[ptr[0] >> 4];
117 	    non_zerop = 1;
118 	}
119 	if (non_zerop || (ptr[0] & 0x0F)) {
120 	    *dst++ = xdigits[ptr[0] & 0x0F];
121 	    non_zerop = 1;
122 	}
123 	if (non_zerop || (ptr[1] >> 4)) {
124 	    *dst++ = xdigits[ptr[1] >> 4];
125 	    non_zerop = 1;
126 	}
127 	*dst++ = xdigits[ptr[1] & 0x0F];
128 	if (i != 7)
129 	    *dst++ = ':';
130 	ptr += 2;
131     }
132     *dst++ = '\0';
133     return orig_dst;
134 }
135 #endif /* HAVE_IPV6 */
136 
137 ROKEN_LIB_FUNCTION const char * ROKEN_LIB_CALL
138 inet_ntop(int af, const void *src, char *dst, size_t size)
139 {
140     switch (af) {
141     case AF_INET :
142 	return inet_ntop_v4 (src, dst, size);
143 #ifdef HAVE_IPV6
144     case AF_INET6 :
145 	return inet_ntop_v6 (src, dst, size);
146 #endif
147     default :
148 	errno = EAFNOSUPPORT;
149 	return NULL;
150     }
151 }
152