xref: /freebsd/lib/libc/inet/inet_neta.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: ISC
3  *
4  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5  * Copyright (c) 1996,1999 by Internet Software Consortium.
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #if defined(LIBC_SCCS) && !defined(lint)
21 static const char rcsid[] = "$Id: inet_neta.c,v 1.3 2005/04/27 04:56:20 sra Exp $";
22 #endif
23 #include "port_before.h"
24 
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <netinet/in.h>
28 #include <arpa/inet.h>
29 
30 #include <errno.h>
31 #include <stdio.h>
32 #include <string.h>
33 
34 #include "port_after.h"
35 
36 #ifdef SPRINTF_CHAR
37 # define SPRINTF(x) strlen(sprintf/**/x)
38 #else
39 # define SPRINTF(x) ((size_t)sprintf x)
40 #endif
41 
42 /*%
43  * char *
44  * inet_neta(src, dst, size)
45  *	format an in_addr_t network number into presentation format.
46  * return:
47  *	pointer to dst, or NULL if an error occurred (check errno).
48  * note:
49  *	format of ``src'' is as for inet_network().
50  * author:
51  *	Paul Vixie (ISC), July 1996
52  */
53 char *
54 inet_neta(in_addr_t src, char *dst, size_t size)
55 {
56 	char *odst = dst;
57 	char *tp;
58 
59 	while (src & 0xffffffff) {
60 		u_char b = (src & 0xff000000) >> 24;
61 
62 		src <<= 8;
63 		if (b) {
64 			if (size < sizeof "255.")
65 				goto emsgsize;
66 			tp = dst;
67 			dst += SPRINTF((dst, "%u", b));
68 			if (src != 0L) {
69 				*dst++ = '.';
70 				*dst = '\0';
71 			}
72 			size -= (size_t)(dst - tp);
73 		}
74 	}
75 	if (dst == odst) {
76 		if (size < sizeof "0.0.0.0")
77 			goto emsgsize;
78 		strcpy(dst, "0.0.0.0");
79 	}
80 	return (odst);
81 
82  emsgsize:
83 	errno = EMSGSIZE;
84 	return (NULL);
85 }
86 
87 /*
88  * Weak aliases for applications that use certain private entry points,
89  * and fail to include <arpa/inet.h>.
90  */
91 #undef inet_neta
92 __weak_reference(__inet_neta, inet_neta);
93 
94 /*! \file */
95