#include<sys/types.h>
#include<netinet/in.h>

int  inet_aton(const char *cp, struct in_addr *ap)
{
    int dots = 0;
    register u_long acc = 0, addr = 0;

    do {
	register char cc = *cp;

	switch (cc) {
	case '0':
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
	    acc = acc * 10 + (cc - '0');
	    break;

	case '.':
	    if (++dots > 3) {
		return 0;
	    }
	    /* Fall through */

	case '\0':
	    if (acc > 255) {
		return 0;
	    }
	    addr = addr << 8 | acc;
	    acc = 0;
	    break;

	default:
	    return 0;
	}
    } while (*cp++) ;

    /* Normalize the address */
    if (dots < 3) {
	addr <<= 8 * (3 - dots) ;
    }

    /* Store it if requested */
    if (ap) {
	ap->s_addr = htonl(addr);
    }

    return 1;    
}