1 /*
2 * Copyright (c) 1996 by 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 DISCLAIMS
9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
15 * SOFTWARE.
16 */
17
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char orig_rcsid[] = "From Id: inet_net_ntop.c,v 8.2 1996/08/08 06:54:44 vixie Exp";
20 static const char rcsid[] = "$Id: inet_net_ntop.c,v 1.1.1.1 2003/11/19 01:51:29 kyu3 Exp $";
21 #endif
22
23 #include <sys/types.h>
24 #include <sys/socket.h>
25 #include <netinet/in.h>
26 #include <arpa/inet.h>
27
28 #include <errno.h>
29 #include <stdio.h>
30 #include <string.h>
31 #include <stdlib.h>
32
33 #ifdef SPRINTF_CHAR
34 # define SPRINTF(x) strlen(sprintf/**/x)
35 #else
36 # define SPRINTF(x) ((size_t)sprintf x)
37 #endif
38
39 static char * inet_net_ntop_ipv4 (const u_char *src, int bits,
40 char *dst, size_t size);
41
42 /*
43 * char *
44 * inet_net_ntop(af, src, bits, dst, size)
45 * convert network number from network to presentation format.
46 * generates CIDR style result always.
47 * return:
48 * pointer to dst, or NULL if an error occurred (check errno).
49 * author:
50 * Paul Vixie (ISC), July 1996
51 */
52 char *
inet_net_ntop(int af,const void * src,int bits,char * dst,size_t size)53 inet_net_ntop(
54 int af,
55 const void *src,
56 int bits,
57 char *dst,
58 size_t size
59 )
60 {
61 switch (af) {
62 case AF_INET:
63 return (inet_net_ntop_ipv4(src, bits, dst, size));
64 default:
65 errno = EAFNOSUPPORT;
66 return (NULL);
67 }
68 }
69
70 /*
71 * static char *
72 * inet_net_ntop_ipv4(src, bits, dst, size)
73 * convert IPv4 network number from network to presentation format.
74 * generates CIDR style result always.
75 * return:
76 * pointer to dst, or NULL if an error occurred (check errno).
77 * note:
78 * network byte order assumed. this means 192.5.5.240/28 has
79 * 0x11110000 in its fourth octet.
80 * author:
81 * Paul Vixie (ISC), July 1996
82 */
83 static char *
inet_net_ntop_ipv4(const u_char * src,int bits,char * dst,size_t size)84 inet_net_ntop_ipv4(
85 const u_char *src,
86 int bits,
87 char *dst,
88 size_t size
89 )
90 {
91 char *odst = dst;
92 char *t;
93 u_int m;
94 int b;
95
96 if (bits < 0 || bits > 32) {
97 errno = EINVAL;
98 return (NULL);
99 }
100 if (bits == 0) {
101 if (size < sizeof "0")
102 goto emsgsize;
103 *dst++ = '0';
104 *dst = '\0';
105 }
106
107 /* Format whole octets. */
108 for (b = bits / 8; b > 0; b--) {
109 if (size < sizeof "255.")
110 goto emsgsize;
111 t = dst;
112 dst += SPRINTF((dst, "%u", *src++));
113 if (b > 1) {
114 *dst++ = '.';
115 *dst = '\0';
116 }
117 size -= (size_t)(dst - t);
118 }
119
120 /* Format partial octet. */
121 b = bits % 8;
122 if (b > 0) {
123 if (size < sizeof ".255")
124 goto emsgsize;
125 t = dst;
126 if (dst != odst)
127 *dst++ = '.';
128 m = ((1 << b) - 1) << (8 - b);
129 dst += SPRINTF((dst, "%u", ((unsigned int)(*src & m))));
130 size -= (size_t)(dst - t);
131 }
132
133 /* Format CIDR /width. */
134 if (size < sizeof "/32")
135 goto emsgsize;
136 dst += SPRINTF((dst, "/%u", bits));
137 return (odst);
138
139 emsgsize:
140 errno = EMSGSIZE;
141 return (NULL);
142 }
143