/*
 * 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);
}