1 /*	$OpenBSD: inet_neta.c,v 1.7 2005/08/06 20:30:03 espie Exp $	*/
2 
3 /*
4  * Copyright (c) 1996 by Internet Software Consortium.
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
11  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
12  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
13  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
14  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
15  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
16  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
17  * SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 #include <sys/socket.h>
22 #include <netinet/in.h>
23 #include <arpa/inet.h>
24 
25 #include <errno.h>
26 #include <stdio.h>
27 #include <string.h>
28 
29 __RCSID("$MirOS: src/lib/libc/net/inet_neta.c,v 1.2 2009/11/09 21:30:51 tg Exp $");
30 
31 /*
32  * char *
33  * inet_neta(src, dst, size)
34  *	format an in_addr_t network number into presentation format.
35  * return:
36  *	pointer to dst, or NULL if an error occurred (check errno).
37  * note:
38  *	format of ``src'' is as for inet_network().
39  * author:
40  *	Paul Vixie (ISC), July 1996
41  */
42 char *
inet_neta(in_addr_t src,char * dst,size_t size)43 inet_neta(in_addr_t src, char *dst, size_t size)
44 {
45 	char *odst = dst;
46 	char *ep;
47 	int advance;
48 
49 	if (src == 0x00000000) {
50 		if (size < sizeof "0.0.0.0")
51 			goto emsgsize;
52 		strlcpy(dst, "0.0.0.0", size);
53 		return dst;
54 	}
55 	ep = dst + size;
56 	if (ep <= dst)
57 		goto emsgsize;
58 	while (src & 0xffffffff) {
59 		u_char b = (src & 0xff000000) >> 24;
60 
61 		src <<= 8;
62 		if (b || src) {
63 			if ((size_t)(ep - dst) < sizeof("255."))
64 				goto emsgsize;
65 			advance = snprintf(dst, ep - dst, "%u", b);
66 			if (advance <= 0 || advance >= ep - dst)
67 				goto emsgsize;
68 			dst += advance;
69 			if (src != 0L) {
70 				if (dst + 1 >= ep)
71 					goto emsgsize;
72 				*dst++ = '.';
73 				*dst = '\0';
74 			}
75 		}
76 	}
77 	return (odst);
78 
79  emsgsize:
80 	errno = EMSGSIZE;
81 	return (NULL);
82 }
83