xref: /illumos-gate/usr/src/lib/libresolv2/common/inet/inet_neta.c (revision 45ede40b2394db7967e59f19288fae9b62efd4aa)
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1996,1999 by Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: inet_neta.c,v 1.3 2005/04/27 04:56:20 sra Exp $";
20 #endif
21 
22 #include "port_before.h"
23 
24 #include <sys/types.h>
25 #include <sys/socket.h>
26 #include <netinet/in.h>
27 #include <arpa/inet.h>
28 
29 #include <errno.h>
30 #include <stdio.h>
31 #include <string.h>
32 
33 #include "port_after.h"
34 
35 #ifdef SPRINTF_CHAR
36 # define SPRINTF(x) strlen(sprintf/**/x)
37 #else
38 # define SPRINTF(x) ((size_t)sprintf x)
39 #endif
40 
41 /*%
42  * char *
43  * inet_neta(src, dst, size)
44  *	format a u_long network number into presentation format.
45  * return:
46  *	pointer to dst, or NULL if an error occurred (check errno).
47  * note:
48  *	format of ``src'' is as for inet_network().
49  * author:
50  *	Paul Vixie (ISC), July 1996
51  */
52 char *
53 inet_neta(src, dst, size)
54 	u_long src;
55 	char *dst;
56 	size_t size;
57 {
58 	char *odst = dst;
59 	char *tp;
60 
61 	while (src & 0xffffffff) {
62 		u_char b = (src & 0xff000000) >> 24;
63 
64 		src <<= 8;
65 		if (b) {
66 			if (size < sizeof "255.")
67 				goto emsgsize;
68 			tp = dst;
69 			dst += SPRINTF((dst, "%u", b));
70 			if (src != 0L) {
71 				*dst++ = '.';
72 				*dst = '\0';
73 			}
74 			size -= (size_t)(dst - tp);
75 		}
76 	}
77 	if (dst == odst) {
78 		if (size < sizeof "0.0.0.0")
79 			goto emsgsize;
80 		strcpy(dst, "0.0.0.0");
81 	}
82 	return (odst);
83 
84  emsgsize:
85 	errno = EMSGSIZE;
86 	return (NULL);
87 }
88 
89 /*! \file */
90