dnet_addr.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)dnet_addr.c	4.1	7/2/90";
#endif lint

/*
 *
 * Copyright (C) 1985 by
 * Digital Equipment Corporation, Maynard, Mass.
 *
 * This software is furnished under a license and may be used and copied
 * only  in  accordance  with  the  terms  of such  license and with the
 * inclusion of the above copyright notice. This software or  any  other
 * copies thereof may not be provided or otherwise made available to any
 * other person. No title to and ownership of  the  software  is  hereby
 * transferred.
 *
 * The information in this software is subject to change without  notice
 * and  should  not be  construed  as  a commitment by Digital Equipment
 * Corporation.
 *
 * Digital assumes no responsibility for the use or  reliability  of its
 * software on equipment which is not supplied by Digital.
 *
 *
 * Networks & Communications Software Engineering
 *
 * IDENT HISTORY:
 *
 * 1.00 10-Jul-1985
 *      DECnet-ULTRIX   V1.0
 *
 */

#include <sys/types.h>
#include <ctype.h>
#include <netdnet/dn.h>

static struct dn_naddr naddr = { sizeof(unsigned short) };

/*
 * DECnet address interpretation routine.
 * Takes an ascii node address string and
 * returns a pointer to a DECnet address structure.
 */
struct dn_naddr *dnet_addr(cp)
register char *cp;
{
	register u_int val, base, n;
	register char c;
	u_int parts[2], *pp = parts;

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 == '.') {
		/*
		 * DECnet formats:
		 *	a
		 *	a.b
		 */
		if (pp >= parts + 2)
			return (0);
		*pp++ = val, cp++;
		goto again;
	}
	/*
	 * Check for trailing characters.
	 */
	if (*cp && !isspace(*cp))
		return (0);
	*pp++ = val;
	/*
	 * Concoct the address according to
	 * the number of parts specified.
	 */
	n = pp - parts;
	switch (n) {

	case 1:				/* a -- 16 bits */
		if (parts[0] & ~0x3ff)
			return (0);
		*(unsigned short *)naddr.a_addr = parts[0];
		return (&naddr);

	case 2:				/* a.b -- 6.10 bits */
		if ((parts[0] & ~0x3f) || (parts[1] & ~0x3ff))
			return (0);
		*(unsigned short *)naddr.a_addr = (parts[0] << 10) | parts[1];
		return (&naddr);

	default:
		return (0);
	}
}