/*

 * 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  	*/

/*

 * seekdir -- C library extension routine

 */

#include	<sys/feature_tests.h>

#if !defined(_LP64)

#pragma weak seekdir64 = _seekdir64

#endif

#pragma weak seekdir = _seekdir

#include	"synonyms.h"

#include	<mtlib.h>

#include	<sys/types.h>

#include	<fcntl.h>

#include	<unistd.h>

#include	<stdio.h>

#include	<dirent.h>

#include	<thread.h>

#include	<synch.h>

extern mutex_t	_dirent_lock;

#ifdef _LP64

void

seekdir(DIR *dirp, long loc)

{

	struct dirent	*dp;

	off_t		off = 0;

	lmutex_lock(&_dirent_lock);

	if (lseek(dirp->dd_fd, 0, SEEK_CUR) != 0) {

		dp = (struct dirent *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];

		off = dp->d_off;

	}

	if (off != loc) {

		dirp->dd_loc = 0;

		(void) lseek(dirp->dd_fd, loc, SEEK_SET);

		dirp->dd_size = 0;

		/*

		 * Save seek offset in d_off field, in case telldir

		 * follows seekdir with no intervening call to readdir

		 */

		((struct dirent *)(uintptr_t)&dirp->dd_buf[0])->d_off = loc;

	}

	lmutex_unlock(&_dirent_lock);

}

#else	/* _LP64 */

static void

seekdir64(DIR *dirp, off64_t loc)

{

	struct dirent64	*dp64;

	off64_t		off = 0;

	lmutex_lock(&_dirent_lock);

	if (lseek64(dirp->dd_fd, 0, SEEK_CUR) != 0) {

		dp64 = (struct dirent64 *)

			(uintptr_t)&dirp->dd_buf[dirp->dd_loc];

		/* was converted by readdir and needs to be reversed */

		if (dp64->d_ino == (ino64_t)-1) {

			struct dirent	*dp32;

			dp32 = (struct dirent *)

			    ((uintptr_t)dp64 + sizeof (ino64_t));

			dp64->d_ino = (ino64_t)dp32->d_ino;

			dp64->d_off = (off64_t)dp32->d_off;

			dp64->d_reclen = (unsigned short)(dp32->d_reclen +

				((char *)&dp64->d_off - (char *)dp64));

		}

		off = dp64->d_off;

	}

	if (off != loc) {

		dirp->dd_loc = 0;

		(void) lseek64(dirp->dd_fd, loc, SEEK_SET);

		dirp->dd_size = 0;

		/*

		 * Save seek offset in d_off field, in case telldir

		 * follows seekdir with no intervening call to readdir

		 */

		((struct dirent64 *)(uintptr_t)&dirp->dd_buf[0])->d_off = loc;

	}

	lmutex_unlock(&_dirent_lock);

}

void

seekdir(DIR *dirp, long loc)

{

	seekdir64(dirp, (off64_t)loc);

}

#endif	/* _LP64 */