xref: /csrg-svn/lib/libc/net/inet_network.c (revision 42626)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #if defined(LIBC_SCCS) && !defined(lint)
9 static char sccsid[] = "@(#)inet_network.c	5.6 (Berkeley) 06/01/90";
10 #endif /* LIBC_SCCS and not lint */
11 
12 #include <sys/types.h>
13 #include <netinet/in.h>
14 #include <ctype.h>
15 
16 /*
17  * Internet network address interpretation routine.
18  * The library routines call this routine to interpret
19  * network numbers.
20  */
21 u_long
22 inet_network(cp)
23 	register char *cp;
24 {
25 	register u_long val, base, n;
26 	register char c;
27 	u_long parts[4], *pp = parts;
28 	register int i;
29 
30 again:
31 	val = 0; base = 10;
32 	if (*cp == '0')
33 		base = 8, cp++;
34 	if (*cp == 'x' || *cp == 'X')
35 		base = 16, cp++;
36 	while (c = *cp) {
37 		if (isdigit(c)) {
38 			val = (val * base) + (c - '0');
39 			cp++;
40 			continue;
41 		}
42 		if (base == 16 && isxdigit(c)) {
43 			val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A'));
44 			cp++;
45 			continue;
46 		}
47 		break;
48 	}
49 	if (*cp == '.') {
50 		if (pp >= parts + 4)
51 			return (INADDR_NONE);
52 		*pp++ = val, cp++;
53 		goto again;
54 	}
55 	if (*cp && !isspace(*cp))
56 		return (INADDR_NONE);
57 	*pp++ = val;
58 	n = pp - parts;
59 	if (n > 4)
60 		return (INADDR_NONE);
61 	for (val = 0, i = 0; i < n; i++) {
62 		val <<= 8;
63 		val |= parts[i] & 0xff;
64 	}
65 	return (val);
66 }
67