/*
 * 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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

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


/*
 *	This routine is a special case, in that it is aware of
 *	both small and large file interfaces. It must be built
 *	in the small compilation environment.
 */

#include <sys/feature_tests.h>

#define	close		_close
#define	lseek		_lseek
#define	open		_open
#if !defined(_LP64)
#define	lseek64		_lseek64
#define	open64		_open64
#endif

#include "lint.h"
#include "file64.h"
#include <mtlib.h>
#include <sys/types.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <limits.h>
#include <thread.h>
#include <synch.h>
#include "stdiom.h"
#include <errno.h>

/*
 * open UNIX file name, associate with iop
 */

FILE *
_endopen(const char *name, const char *type, FILE *iop, int largefile)
{
	int oflag, fd;
	char plus;
	rmutex_t *lk;

	if (iop == NULL)
		return (NULL);
	switch (type[0]) {
	default:
		errno = EINVAL;
		return (NULL);
	case 'r':
		oflag = O_RDONLY;
		break;
	case 'w':
		oflag = O_WRONLY | O_TRUNC | O_CREAT;
		break;
	case 'a':
		oflag = O_WRONLY | O_APPEND | O_CREAT;
		break;
	}
	/* UNIX ignores 'b' and treats text and binary the same */
	if ((plus = type[1]) == 'b')
		plus = type[2];
	if (plus == '+')
		oflag = (oflag & ~(O_RDONLY | O_WRONLY)) | O_RDWR;

	/* select small or large file open based on flag */
	if (largefile) {
		fd = open64(name, oflag, 0666);
	} else {
		fd = open(name, oflag, 0666);
	}
	if (fd < 0)
		return (NULL);

#ifdef	_LP64
	iop->_file = fd;
#else
	if (fd > UCHAR_MAX) {
		(void) close(fd);
		errno = EMFILE;
		return (NULL);
	}
	iop->_file = (unsigned char)fd; /* assume fits in unsigned char */
#endif	/*	_LP64	*/

	FLOCKFILE(lk, iop);		/* this lock may be unnecessary */

#ifdef	_LP64
	iop->_flag &= ~0377;	/* clear lower 8-bits */
	if (plus == '+')
		iop->_flag |= _IORW;
	else if (type[0] == 'r')
		iop->_flag |= _IOREAD;
	else
		iop->_flag |= _IOWRT;
#else
	if (plus == '+')
		iop->_flag = _IORW;
	else if (type[0] == 'r')
		iop->_flag = _IOREAD;
	else
		iop->_flag = _IOWRT;
#endif	/*	_LP64	*/
	FUNLOCKFILE(lk);
	if (oflag == (O_WRONLY | O_APPEND | O_CREAT)) {	/* type == "a" */
		if (lseek64(fd, (off64_t)0, SEEK_END) < (off64_t)0) {
			(void) close(fd);
			return (NULL);
		}
	}

	return (iop);
}