/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2013 Gary Mills
 *
 * Copyright (c) 1997, by Sun Microsystems, Inc.
 * All rights reserved.
 */

/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
/*	  All Rights Reserved	*/

/*LINTLIBRARY*/

#include	<sys/types.h>
#include	<stdio.h>
#include	<ctype.h>
#include	<userdefs.h>
#include	<users.h>
#include	<deflt.h>
#include	<limits.h>

/* Defaults file */
#define	DEFAULT_USERADD "/etc/default/useradd"

/*
 * validate string given as login name.
 */
int
valid_login(char *login, struct passwd **pptr, int *warning)
{
	struct passwd *t_pptr;
	char *ptr = login;
	int bad1char, badc, clower, len;
	char c;
	char action;

	len = 0; clower = 0; badc = 0; bad1char = 0;
	*warning = 0;
	if (!login || !*login)
		return (INVALID);

	c = *ptr;
	if (!isalpha(c))
		bad1char++;
	for (; c != '\0'; ptr++, c = *ptr) {
		len++;
		if (!isprint(c) || (c == ':') || (c == '\n'))
			return (INVALID);
		if (!isalnum(c) && c != '_' && c != '-' && c != '.')
			badc++;
		if (islower(c))
			clower++;
	}

	action = 'w';
	if (defopen(DEFAULT_USERADD) == 0) {
		char *defptr;

		if ((defptr = defread("EXCEED_TRAD=")) != NULL) {
			char let = tolower(*defptr);

			switch (let) {
			case 'w':	/* warning */
			case 'e':	/* error */
			case 's':	/* silent */
				action = let;
				break;
			}
		}
		(void) defopen((char *)NULL);
	}

	if (len > LOGNAME_MAX)
		return (LONGNAME);

	if (len > LOGNAME_MAX_TRAD) {
		if (action == 'w')
			*warning = *warning | WARN_NAME_TOO_LONG;
		else if (action == 'e')
			return (LONGNAME);
	}

	if (clower == 0)
		*warning = *warning | WARN_NO_LOWERCHAR;
	if (badc != 0)
		*warning = *warning | WARN_BAD_LOGNAME_CHAR;
	if (bad1char != 0)
		*warning = *warning | WARN_BAD_LOGNAME_FIRST;

	if ((t_pptr = getpwnam(login)) != NULL) {
		if (pptr) *pptr = t_pptr;
		return (NOTUNIQUE);
	}
	return (UNIQUE);
}