/*	inet_addr.c	4.5	82/11/14	*/#include <sys/types.h>#include <ctype.h>#include <netinet/in.h>/* * Internet address interpretation routine. * All the network library routines call this * routine to interpret entries in the data bases * which are expected to be an address. * The value returned is in network order. */u_longinet_addr(cp)	register char *cp;{	register u_long val, base, n;	register char c;	u_long parts[4], *pp = parts;	/* avoid null pointer de-reference on mips */	if (cp == 0)		return(-1);again:	/*	 * Collect number up to ``.''.	 * Values are specified as for C:	 * 0x=hex, 0=octal, other=decimal.	 */	val = 0; base = 10;	if (*cp == '0')		base = 8, cp++;	if (*cp == 'x' || *cp == 'X')		base = 16, cp++;	while (c = *cp) {		if (isdigit(c)) {			val = (val * base) + (c - '0');			cp++;			continue;		}		if (base == 16 && isxdigit(c)) {			val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A'));			cp++;			continue;		}		break;	}	if (*cp == '.') {		/*		 * Internet format:		 *	a.b.c.d		 *	a.b.c	(with c treated as 16-bits)		 *	a.b	(with b treated as 24 bits)		 */		if (pp >= parts + 4)			return (-1);		*pp++ = val, cp++;		goto again;	}	/*	 * Check for trailing characters.	 */	if (*cp && !isspace(*cp))		return (-1);	*pp++ = val;	/*	 * Concoct the address according to	 * the number of parts specified.	 */	n = pp - parts;	switch (n) {	case 1:				/* a -- 32 bits */		val = parts[0];		break;	case 2:				/* a.b -- 8.24 bits */		val = (parts[0] << 24) | (parts[1] & 0xffffff);		break;	case 3:				/* a.b.c -- 8.8.16 bits */		val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) |			(parts[2] & 0xffff);		break;	case 4:				/* a.b.c.d -- 8.8.8.8 bits */		val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) |		      ((parts[2] & 0xff) << 8) | (parts[3] & 0xff);		break;	default:		return (-1);	}	val = htonl(val);	return (val);}