#
/* names.c */

/* EMACS_MODES: c !fill */


/* Resolve a host name into an internet address.  Three name formats are
 * accepted:
 *	1) A character string host name
 *	2) An octal host number, in the form:
 *		<net>,<subnet>,<rsd>,<host>
 *	   Any of the <net>, <subnet>, and <rsd> may be left blank or left out
 *	   entirely; they default to the local net/subnet.
 *	3) A thirty-two bit hex number, preceeded by a '#', which is used
 * 	   without interpretation as the host number.
 *
 * The following routines are included in this file:
 *	resolve_name	Resolve a name as specified above
 *	gethmch		Parse a hex machine address specification
 *	getomch		Parse an octal machine address specification
 */


#define	INSZ	4
#define	TRUE	1
#define	FALSE	0

/* Format of host tables */
extern struct	mach  {
	char	*m_name;
	int	m_id;
	}	mach[];

extern struct	mchid  {
	char	m_addr[INSZ];
	int	m_type;
	}	mchid[];

extern int	nmach;

#define MYNET	022
#define MYSNET	012
#define MYRSD	0
#define MYHOST	010



resolve_name (name, paddr)

/* Resolve foreign host internet address
 * Scan table of host names and nicknames.
 * On each pass, include one more letter in comparison
 * and count no. matches.
 * When only have one match, have found host name so quit search - return TRUE
 * When more than one match, do another pass (which will include
 * one more letter in comparison).
 * When find no matches, error - cannot recognize name - return FALSE
 *
 * Arguments:
 */

char	*name;				/* name to resolve */
char	*paddr;				/* ptr. to place to return in addr */
{
	register char	*q, *p;
	register	i;
	int		j, nfnd, fnd, pass;


	if ((*name >= '0') && (*name <= '7'))
		return (getomch(name, paddr));

	if (*name == '#')
		return (gethmch(name, paddr));

	for (pass = 1; ; pass++)  {
		nfnd = 0;
		for (j = 0; j < nmach; j++) {
			p = name;
			q = mach[j].m_name;
			for (i = 0; i < pass; i++)
				if (*p++ != *q++) break;
			if (i == pass) {
				fnd = j;
				nfnd++;
				}
			}
		if (nfnd > 1) continue;
		if (nfnd == 0)
			return (FALSE);
		if (nfnd == 1)  {
			fnd = mach[fnd].m_id;
			for (i = 0; i < INSZ; i++)
				paddr[i] = mchid[fnd].m_addr[i];
			return (TRUE);
			}
		}
}

/* Parse foreign host number input as hex string */
gethmch(name, paddr)
char	*name;
register char	*paddr;
{
	register char	*tmp;
	register int	i;

	tmp = &name[1];
	for (i = 0; i < 8; i++) {
		if ((*tmp >= '0') && (*tmp <= '9'))
			*tmp++ -= '0';
		else if ((*tmp >= 'A') && (*tmp <= 'Z'))
			*tmp++ -= ('A' - 10);
		else if ((*tmp >= 'a') && (*tmp <= 'z'))
			*tmp++ -= ('a' - 10);
		else return (FALSE);
		}

	if (*tmp != 0) return (FALSE);

	tmp = &name[1];
	for (i = 0; i < INSZ; i++)
		*paddr++ = ((*tmp++ << 4) + *tmp++);

	return (TRUE);
}

/* Parse foreign host number input as octal string */
getomch(name, paddr)
char	*name;
char	*paddr;
{
	char		tmp[INSZ];
	register char	*p;
	register int	i, j;
	int		n;

	paddr[0] = MYNET;
	paddr[1] = MYSNET;
	paddr[2] = MYRSD;
	paddr[3] = MYHOST;

	p = name;
	for (i = 0; i < INSZ; i++) {
		n = 0;
		while((*p >= '0') && (*p <= '7')) {
			n = ((n << 3) + (*p++ - '0'));
			if (n > 0377) return (FALSE);
			}
		tmp[i] = n;
		if (*p == 0) break;
		if (*p == ',') p++;
		else return (FALSE);
		}

	if (i == INSZ) return (FALSE);

	for (j = 3; j >= 0; j--) {
		paddr[j] = tmp[i];
		if (--i < 0) break;
		}

	return (TRUE);
}