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 | #if defined(LIBC_SCCS) && !defined(lint) |
19 | static const char rcsid[] = "$BINDId: inet_net_ntop.c,v 1.6 1999/01/08 19:23:42 vixie Exp $" ; |
20 | #endif |
21 | |
22 | #include <sys/types.h> |
23 | #include <sys/socket.h> |
24 | #include <netinet/in.h> |
25 | #include <arpa/inet.h> |
26 | |
27 | #include <errno.h> |
28 | #include <stdio.h> |
29 | #include <string.h> |
30 | #include <stdlib.h> |
31 | |
32 | #ifdef SPRINTF_CHAR |
33 | # define SPRINTF(x) strlen(sprintf/**/x) |
34 | #else |
35 | # define SPRINTF(x) ((size_t)sprintf x) |
36 | #endif |
37 | |
38 | static char * inet_net_ntop_ipv4 (const u_char *src, int bits, |
39 | char *dst, size_t size) __THROW; |
40 | |
41 | /* |
42 | * char * |
43 | * inet_net_ntop(af, src, bits, dst, size) |
44 | * convert network number from network to presentation format. |
45 | * generates CIDR style result always. |
46 | * return: |
47 | * pointer to dst, or NULL if an error occurred (check errno). |
48 | * author: |
49 | * Paul Vixie (ISC), July 1996 |
50 | */ |
51 | char * |
52 | inet_net_ntop (int af, const void *src, int bits, char *dst, size_t size) |
53 | { |
54 | switch (af) { |
55 | case AF_INET: |
56 | return (inet_net_ntop_ipv4(src, bits, dst, size)); |
57 | default: |
58 | __set_errno (EAFNOSUPPORT); |
59 | return (NULL); |
60 | } |
61 | } |
62 | |
63 | /* |
64 | * static char * |
65 | * inet_net_ntop_ipv4(src, bits, dst, size) |
66 | * convert IPv4 network number from network to presentation format. |
67 | * generates CIDR style result always. |
68 | * return: |
69 | * pointer to dst, or NULL if an error occurred (check errno). |
70 | * note: |
71 | * network byte order assumed. this means 192.5.5.240/28 has |
72 | * 0b11110000 in its fourth octet. |
73 | * author: |
74 | * Paul Vixie (ISC), July 1996 |
75 | */ |
76 | static char * |
77 | inet_net_ntop_ipv4 (const u_char *src, int bits, char *dst, size_t size) |
78 | { |
79 | char *odst = dst; |
80 | char *t; |
81 | u_int m; |
82 | int b; |
83 | |
84 | if (bits < 0 || bits > 32) { |
85 | __set_errno (EINVAL); |
86 | return (NULL); |
87 | } |
88 | if (bits == 0) { |
89 | if (size < sizeof "0" ) |
90 | goto emsgsize; |
91 | *dst++ = '0'; |
92 | size--; |
93 | *dst = '\0'; |
94 | } |
95 | |
96 | /* Format whole octets. */ |
97 | for (b = bits / 8; b > 0; b--) { |
98 | if (size < sizeof "255." ) |
99 | goto emsgsize; |
100 | t = dst; |
101 | dst += SPRINTF((dst, "%u" , *src++)); |
102 | if (b > 1) { |
103 | *dst++ = '.'; |
104 | *dst = '\0'; |
105 | } |
106 | size -= (size_t)(dst - t); |
107 | } |
108 | |
109 | /* Format partial octet. */ |
110 | b = bits % 8; |
111 | if (b > 0) { |
112 | if (size < sizeof ".255" ) |
113 | goto emsgsize; |
114 | t = dst; |
115 | if (dst != odst) |
116 | *dst++ = '.'; |
117 | m = ((1 << b) - 1) << (8 - b); |
118 | dst += SPRINTF((dst, "%u" , *src & m)); |
119 | size -= (size_t)(dst - t); |
120 | } |
121 | |
122 | /* Format CIDR /width. */ |
123 | if (size < sizeof "/32" ) |
124 | goto emsgsize; |
125 | dst += SPRINTF((dst, "/%u" , bits)); |
126 | return (odst); |
127 | |
128 | emsgsize: |
129 | __set_errno (EMSGSIZE); |
130 | return (NULL); |
131 | } |
132 | |