RCS_ID_C = "$Id: linkaddr.c,v 4.1 1994/09/29 23:09:02 jraja Exp $";
/*
 *      linkaddr.c - link level address parsing 
 *
 *      Copyright © 1994 AmiTCP/IP Group, 
 *                       Network Solutions Development Inc.
 *                       All rights reserved.
 *
 *      Copyright © 1991 Regents of the University of California.
 */

#if 0
static char sccsid[] = "@(#)linkaddr.c	5.2 (Berkeley) 2/24/91";
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <string.h>

/* States*/
#define NAMING	0
#define GOTONE	1
#define GOTTWO	2
#define RESET	3
/* Inputs */
#define	DIGIT	(4*0)
#define	END	(4*1)
#define DELIM	(4*2)
#define LETTER	(4*3)

void
link_addr(addr, sdl)
	register const char *addr;
	register struct sockaddr_dl *sdl;
{
	register char *cp = sdl->sdl_data;
	char *cplim = sdl->sdl_len + (char *)sdl;
	register int byte = 0, state = NAMING, new;

	bzero((char *)&sdl->sdl_family, sdl->sdl_len - 1);
	sdl->sdl_family = AF_LINK;
	do {
		state &= ~LETTER;
		if ((*addr >= '0') && (*addr <= '9')) {
			new = *addr - '0';
		} else if ((*addr >= 'a') && (*addr <= 'f')) {
			new = *addr - 'a' + 10;
		} else if ((*addr >= 'A') && (*addr <= 'F')) {
			new = *addr - 'A' + 10;
		} else if (*addr == 0) {
			state |= END;
		} else if (state == NAMING &&
			   (((*addr >= 'A') && (*addr <= 'Z')) ||
			   ((*addr >= 'a') && (*addr <= 'z'))))
			state |= LETTER;
		else
			state |= DELIM;
		addr++;
		switch (state /* | INPUT */) {
		case NAMING | DIGIT:
		case NAMING | LETTER:
			*cp++ = addr[-1]; continue;
		case NAMING | DELIM:
			state = RESET; sdl->sdl_nlen = cp - sdl->sdl_data; continue;
		case GOTTWO | DIGIT:
			*cp++ = byte; /*FALLTHROUGH*/
		case RESET | DIGIT:
			state = GOTONE; byte = new; continue;
		case GOTONE | DIGIT:
			state = GOTTWO; byte = new + (byte << 4); continue;
		default: /* | DELIM */
			state = RESET; *cp++ = byte; byte = 0; continue;
		case GOTONE | END:
		case GOTTWO | END:
			*cp++ = byte; /* FALLTHROUGH */
		case RESET | END:
			break;
		}
		break;
	} while (cp < cplim); 
	sdl->sdl_alen = cp - LLADDR(sdl);
	new = cp - (char *)sdl;
	if (new > sizeof(*sdl))
		sdl->sdl_len = new;
	return;
}