xref: /freebsd/lib/libc/inet/inet_neta.c (revision faf25f48d601ae39f5752602f3020e2e92605625)
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 $";
22 #endif
23 #include <sys/cdefs.h>
24 __FBSDID("$FreeBSD$");
25 
26 #include "port_before.h"
27 
28 #include <sys/types.h>
29 #include <sys/socket.h>
30 #include <netinet/in.h>
31 #include <arpa/inet.h>
32 
33 #include <errno.h>
34 #include <stdio.h>
35 #include <string.h>
36 
37 #include "port_after.h"
38 
39 #ifdef SPRINTF_CHAR
40 # define SPRINTF(x) strlen(sprintf/**/x)
41 #else
42 # define SPRINTF(x) ((size_t)sprintf x)
43 #endif
44 
45 /*%
46  * char *
47  * inet_neta(src, dst, size)
48  *	format an in_addr_t network number into presentation format.
49  * return:
50  *	pointer to dst, or NULL if an error occurred (check errno).
51  * note:
52  *	format of ``src'' is as for inet_network().
53  * author:
54  *	Paul Vixie (ISC), July 1996
55  */
56 char *
57 inet_neta(in_addr_t src, char *dst, size_t size)
58 {
59 	char *odst = dst;
60 	char *tp;
61 
62 	while (src & 0xffffffff) {
63 		u_char b = (src & 0xff000000) >> 24;
64 
65 		src <<= 8;
66 		if (b) {
67 			if (size < sizeof "255.")
68 				goto emsgsize;
69 			tp = dst;
70 			dst += SPRINTF((dst, "%u", b));
71 			if (src != 0L) {
72 				*dst++ = '.';
73 				*dst = '\0';
74 			}
75 			size -= (size_t)(dst - tp);
76 		}
77 	}
78 	if (dst == odst) {
79 		if (size < sizeof "0.0.0.0")
80 			goto emsgsize;
81 		strcpy(dst, "0.0.0.0");
82 	}
83 	return (odst);
84 
85  emsgsize:
86 	errno = EMSGSIZE;
87 	return (NULL);
88 }
89 
90 /*
91  * Weak aliases for applications that use certain private entry points,
92  * and fail to include <arpa/inet.h>.
93  */
94 #undef inet_neta
95 __weak_reference(__inet_neta, inet_neta);
96 
97 /*! \file */
98