1 /*
2 * Copyright (c) 1996,1999 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 #include <sys/types.h>
19 #include <sys/socket.h>
20 #include <netinet/in.h>
21 #include <arpa/inet.h>
22
23 #include <errno.h>
24 #include <stdio.h>
25 #include <string.h>
26 #include <stdlib.h>
27
28 #ifdef SPRINTF_CHAR
29 # define SPRINTF(x) strlen(sprintf/**/x)
30 #else
31 # define SPRINTF(x) ((size_t)sprintf x)
32 #endif
33
34 static char * inet_net_ntop_ipv4 (const u_char *src, int bits,
35 char *dst, size_t size) __THROW;
36
37 /*
38 * char *
39 * inet_net_ntop(af, src, bits, dst, size)
40 * convert network number from network to presentation format.
41 * generates CIDR style result always.
42 * return:
43 * pointer to dst, or NULL if an error occurred (check errno).
44 * author:
45 * Paul Vixie (ISC), July 1996
46 */
47 char *
inet_net_ntop(int af,const void * src,int bits,char * dst,size_t size)48 inet_net_ntop (int af, const void *src, int bits, char *dst, size_t size)
49 {
50 switch (af) {
51 case AF_INET:
52 return (inet_net_ntop_ipv4(src, bits, dst, size));
53 default:
54 __set_errno (EAFNOSUPPORT);
55 return (NULL);
56 }
57 }
58
59 /*
60 * static char *
61 * inet_net_ntop_ipv4(src, bits, dst, size)
62 * convert IPv4 network number from network to presentation format.
63 * generates CIDR style result always.
64 * return:
65 * pointer to dst, or NULL if an error occurred (check errno).
66 * note:
67 * network byte order assumed. this means 192.5.5.240/28 has
68 * 0b11110000 in its fourth octet.
69 * author:
70 * Paul Vixie (ISC), July 1996
71 */
72 static char *
inet_net_ntop_ipv4(const u_char * src,int bits,char * dst,size_t size)73 inet_net_ntop_ipv4 (const u_char *src, int bits, char *dst, size_t size)
74 {
75 char *odst = dst;
76 char *t;
77 u_int m;
78 int b;
79
80 if (bits < 0 || bits > 32) {
81 __set_errno (EINVAL);
82 return (NULL);
83 }
84 if (bits == 0) {
85 if (size < sizeof "0")
86 goto emsgsize;
87 *dst++ = '0';
88 size--;
89 *dst = '\0';
90 }
91
92 /* Format whole octets. */
93 for (b = bits / 8; b > 0; b--) {
94 if (size < sizeof "255.")
95 goto emsgsize;
96 t = dst;
97 dst += SPRINTF((dst, "%u", *src++));
98 if (b > 1) {
99 *dst++ = '.';
100 *dst = '\0';
101 }
102 size -= (size_t)(dst - t);
103 }
104
105 /* Format partial octet. */
106 b = bits % 8;
107 if (b > 0) {
108 if (size < sizeof ".255")
109 goto emsgsize;
110 t = dst;
111 if (dst != odst)
112 *dst++ = '.';
113 m = ((1 << b) - 1) << (8 - b);
114 dst += SPRINTF((dst, "%u", *src & m));
115 size -= (size_t)(dst - t);
116 }
117
118 /* Format CIDR /width. */
119 if (size < sizeof "/32")
120 goto emsgsize;
121 dst += SPRINTF((dst, "/%u", bits));
122 return (odst);
123
124 emsgsize:
125 __set_errno (EMSGSIZE);
126 return (NULL);
127 }
128