genmask.c revision 253468 
1/*
2 * Copyright (C) 1993-2001 by Darren Reed.
3 *
4 * See the IPFILTER.LICENCE file for details on licencing.
5 *
6 * $Id: genmask.c,v 1.7 2003/11/11 13:40:15 darrenr Exp $
7 */
8
9#include "ipf.h"
10
11
12int genmask(msk, mskp)
13char *msk;
14u_32_t *mskp;
15{
16	char *endptr = 0L;
17	int bits;
18
19	if (strchr(msk, '.') || strchr(msk, 'x') || strchr(msk, ':')) {
20		/* possibly of the form xxx.xxx.xxx.xxx
21		 * or 0xYYYYYYYY */
22#ifdef	USE_INET6
23		if (use_inet6) {
24			if (inet_pton(AF_INET6, msk, mskp) != 1)
25				return -1;
26		} else
27#endif
28		if (inet_aton(msk, (struct in_addr *)mskp) == 0)
29			return -1;
30	} else {
31		/*
32		 * set x most significant bits
33		 */
34		bits = (int)strtol(msk, &endptr, 0);
35#ifdef	USE_INET6
36		if ((*endptr != '\0') ||
37		    ((bits > 32) && !use_inet6) || (bits < 0) ||
38		    ((bits > 128) && use_inet6))
39#else
40		if (*endptr != '\0' || bits > 32 || bits < 0)
41#endif
42			return -1;
43#ifdef	USE_INET6
44		if (use_inet6)
45			fill6bits(bits, mskp);
46		else
47#endif
48		if (bits == 0)
49			*mskp = 0;
50		else
51			*mskp = htonl(0xffffffff << (32 - bits));
52	}
53	return 0;
54}
55