/*

 * 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  	*/

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

/*

 * readdir_r -- C library extension routine

 */

#include	<sys/feature_tests.h>

#if !defined(_LP64)

#pragma weak _readdir64_r = readdir64_r

#endif

#include "lint.h"

#include "libc.h"

#include <mtlib.h>

#include <unistd.h>

#include <dirent.h>

#include <string.h>

#include <limits.h>

#include <errno.h>

#ifdef _LP64

/*

 * POSIX.1c standard version of the thread function readdir_r.

 */

int

readdir_r(DIR *dirp, dirent_t *entry, dirent_t **result)

{

	private_DIR *pdirp = (private_DIR *)dirp;

	dirent_t *dp;		/* -> directory data */

	int saveloc = 0;

	lmutex_lock(&pdirp->dd_lock);

	if (dirp->dd_size != 0) {

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

		saveloc = dirp->dd_loc;		/* save for possible EOF */

		dirp->dd_loc += (int)dp->d_reclen;

	}

	if (dirp->dd_loc >= dirp->dd_size)

		dirp->dd_loc = dirp->dd_size = 0;

	if (dirp->dd_size == 0 &&	/* refill buffer */

	    (dirp->dd_size = getdents(dirp->dd_fd,

	    (dirent_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {

		if (dirp->dd_size == 0) {	/* This means EOF */

			dirp->dd_loc = saveloc;	/* so save for telldir */

			lmutex_unlock(&pdirp->dd_lock);

			*result = NULL;

			return (0);

		}

		lmutex_unlock(&pdirp->dd_lock);

		*result = NULL;

		return (errno);		/* error */

	}

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

	(void) memcpy(entry, dp, (size_t)dp->d_reclen);

	lmutex_unlock(&pdirp->dd_lock);

	*result = entry;

	return (0);

}

#else	/* _LP64 */

/*

 * POSIX.1c standard version of the thr function readdir_r.

 * Large file version.

 */

int

readdir64_r(DIR *dirp, dirent64_t *entry, dirent64_t **result)

{

	private_DIR *pdirp = (private_DIR *)(uintptr_t)dirp;

	dirent64_t *dp64;	/* -> directory data */

	int saveloc = 0;

	lmutex_lock(&pdirp->dd_lock);

	if (dirp->dd_size != 0) {

		dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];

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

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

			dirent_t *dp32;	/* -> 32 bit directory data */

			dp32 = (dirent_t *)(&dp64->d_off);

			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));

		}

		saveloc = dirp->dd_loc;		/* save for possible EOF */

		dirp->dd_loc += (int)dp64->d_reclen;

	}

	if (dirp->dd_loc >= dirp->dd_size)

		dirp->dd_loc = dirp->dd_size = 0;

	if (dirp->dd_size == 0 &&	/* refill buffer */

	    (dirp->dd_size = getdents64(dirp->dd_fd,

	    (dirent64_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {

		if (dirp->dd_size == 0) {	/* This means EOF */

			dirp->dd_loc = saveloc;	/* so save for telldir */

			lmutex_unlock(&pdirp->dd_lock);

			*result = NULL;

			return (0);

		}

		lmutex_unlock(&pdirp->dd_lock);

		*result = NULL;

		return (errno);		/* error */

	}

	dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];

	(void) memcpy(entry, dp64, (size_t)dp64->d_reclen);

	*result = entry;

	lmutex_unlock(&pdirp->dd_lock);

	return (0);

}

/*

 * POSIX.1c standard version of the function readdir_r.

 * User gets it via static readdir_r from header file.

 */

int

__posix_readdir_r(DIR *dirp, dirent_t *entry, dirent_t **result)

{

	int error;

	dirent64_t *dp64;

	struct {

		dirent64_t dirent64;

		char chars[MAXNAMLEN];

	} buf;

	error = readdir64_r(dirp, (dirent64_t *)&buf, &dp64);

	if (error != 0 || dp64 == NULL) {

		*result = NULL;

		return (error);

	}

	if (dp64->d_ino > SIZE_MAX ||

	    (uint64_t)dp64->d_off > (uint64_t)UINT32_MAX) {

		*result = NULL;

		return (EOVERFLOW);

	}

	entry->d_ino = (ino_t)dp64->d_ino;

	entry->d_off = (off_t)dp64->d_off;

	entry->d_reclen = (unsigned short)((((char *)entry->d_name -

	    (char *)entry) + strlen(dp64->d_name) + 1 + 3) & ~3);

	(void) strcpy(entry->d_name, dp64->d_name);

	*result = entry;

	return (0);

}

/*

 * POSIX.1c Draft-6 version of the function readdir_r.

 * It was implemented by Solaris 2.3.

 */

dirent_t *

readdir_r(DIR *dirp, dirent_t *entry)

{

	int error;

	dirent_t *result;

	if ((error = __posix_readdir_r(dirp, entry, &result)) != 0)

		errno = error;

	return (result);

}

#endif	/* _LP64 */