/*
 * Copyright (c) 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/lib/libc/gen/getlogin.c,v 1.4.2.1 2001/03/05 09:06:50 obrien Exp $
 *
 * @(#)getlogin.c       8.1 (Berkeley) 6/4/93
 */

#include <sys/param.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "namespace.h"
#include <pthread.h>
#include "un-namespace.h"

#include "libc_private.h"

#define THREAD_LOCK()   if (__isthreaded) _pthread_mutex_lock(&logname_mutex)
#define THREAD_UNLOCK() if (__isthreaded) _pthread_mutex_unlock(&logname_mutex)

extern int              _getlogin(char *, size_t);
 
int                     _logname_valid;         /* known to setlogin() */
static pthread_mutex_t  logname_mutex = PTHREAD_MUTEX_INITIALIZER;

static char *
getlogin_basic(int *status)
{
        static char logname[MAXLOGNAME];

        if (_logname_valid == 0) {
                if (_getlogin(logname, sizeof(logname)) < 0) {
                        *status = errno;
                        return (NULL);
                }
                _logname_valid = 1;
        }
        *status = 0;
        return (*logname ? logname : NULL);
}

char *
getlogin(void)
{
        char    *result;
        int     status;

        THREAD_LOCK();
        result = getlogin_basic(&status);
        THREAD_UNLOCK();
        return (result);
}

int
getlogin_r(char *logname, size_t namelen)
{
        char    *result;
        size_t  len;
        int     status;
        
        THREAD_LOCK();
        result = getlogin_basic(&status);
        if (status == 0) {
                if ((len = strlen(result) + 1) > namelen)
                        status = ERANGE;
                else
                        strncpy(logname, result, len);
        }
        THREAD_UNLOCK();
        return (status);
}