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 * |
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 * |
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 | |