/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */

/*
 * Return the number of the slot in the utmp file
 * corresponding to the current user: try for file 0, 1, 2.
 * Returns -1 if slot not found.
 */

#include "lint.h"
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <utmpx.h>
#include <stdlib.h>
#include <pthread.h>

#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif

int
ttyslot(void)
{
        struct futmpx ubuf;
        char *p;
        int s;
        int ret = -1;
        int console = FALSE;
        char ttynm[128];
        FILE *fp;
        int cancel_state;

        /*
         * The UNIX98 Posix conformance test suite requires
         * ttyslot() to not be a cancellation point.
         */
        (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);

        if ((p = ttyname_r(0, ttynm, 128)) != NULL ||
            (p = ttyname_r(1, ttynm, 128)) != NULL ||
            (p = ttyname_r(2, ttynm, 128)) != NULL) {
                if (strncmp(p, "/dev/", 5) == 0)
                        p += 5;
                if (strcmp(p, "console") == 0)
                        console = TRUE;
                s = 0;
                if ((fp = fopen(UTMPX_FILE, "rF")) != NULL) {
                        while ((fread(&ubuf, sizeof (ubuf), 1, fp)) == 1) {
                                if ((ubuf.ut_type == INIT_PROCESS ||
                                    ubuf.ut_type == LOGIN_PROCESS ||
                                    ubuf.ut_type == USER_PROCESS) &&
                                    strncmp(p, ubuf.ut_line,
                                    sizeof (ubuf.ut_line)) == 0) {
                                        ret = s;
                                        if (!console ||
                                            strncmp(ubuf.ut_host, ":0", 2) == 0)
                                                break;
                                }
                                s++;
                        }
                        (void) fclose(fp);
                }
        }

        (void) pthread_setcancelstate(cancel_state, NULL);
        return (ret);
}