xref: /original-bsd/lib/libc/net/inet_network.c (revision ad93c43e)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that this notice is preserved and that due credit is given
7  * to the University of California at Berkeley. The name of the University
8  * may not be used to endorse or promote products derived from this
9  * software without specific prior written permission. This software
10  * is provided ``as is'' without express or implied warranty.
11  */
12 
13 #if defined(LIBC_SCCS) && !defined(lint)
14 static char sccsid[] = "@(#)inet_network.c	5.4 (Berkeley) 03/07/88";
15 #endif /* LIBC_SCCS and not lint */
16 
17 #include <sys/types.h>
18 #include <netinet/in.h>
19 #include <ctype.h>
20 
21 /*
22  * Internet network address interpretation routine.
23  * The library routines call this routine to interpret
24  * network numbers.
25  */
26 u_long
27 inet_network(cp)
28 	register char *cp;
29 {
30 	register u_long val, base, n;
31 	register char c;
32 	u_long parts[4], *pp = parts;
33 	register int i;
34 
35 again:
36 	val = 0; base = 10;
37 	if (*cp == '0')
38 		base = 8, cp++;
39 	if (*cp == 'x' || *cp == 'X')
40 		base = 16, cp++;
41 	while (c = *cp) {
42 		if (isdigit(c)) {
43 			val = (val * base) + (c - '0');
44 			cp++;
45 			continue;
46 		}
47 		if (base == 16 && isxdigit(c)) {
48 			val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A'));
49 			cp++;
50 			continue;
51 		}
52 		break;
53 	}
54 	if (*cp == '.') {
55 		if (pp >= parts + 4)
56 			return (INADDR_NONE);
57 		*pp++ = val, cp++;
58 		goto again;
59 	}
60 	if (*cp && !isspace(*cp))
61 		return (INADDR_NONE);
62 	*pp++ = val;
63 	n = pp - parts;
64 	if (n > 4)
65 		return (INADDR_NONE);
66 	for (val = 0, i = 0; i < n; i++) {
67 		val <<= 8;
68 		val |= parts[i] & 0xff;
69 	}
70 	return (val);
71 }
72