1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1988 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"
31
32/*
33 * seekdir -- C library extension routine
34 */
35
36#include	<sys/feature_tests.h>
37
38#if !defined(_LP64)
39#pragma weak _seekdir64 = seekdir64
40#endif
41#pragma weak _seekdir = seekdir
42
43#include "lint.h"
44#include "libc.h"
45#include <mtlib.h>
46#include <dirent.h>
47#include <fcntl.h>
48#include <unistd.h>
49
50#ifdef _LP64
51
52void
53seekdir(DIR *dirp, long loc)
54{
55	private_DIR	*pdirp = (private_DIR *)dirp;
56	dirent_t	*dp;
57	off_t		off = 0;
58
59	lmutex_lock(&pdirp->dd_lock);
60	if (lseek(dirp->dd_fd, 0, SEEK_CUR) != 0) {
61		dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
62		off = dp->d_off;
63	}
64	if (off != loc) {
65		dirp->dd_loc = 0;
66		(void) lseek(dirp->dd_fd, loc, SEEK_SET);
67		dirp->dd_size = 0;
68
69		/*
70		 * Save seek offset in d_off field, in case telldir
71		 * follows seekdir with no intervening call to readdir
72		 */
73		((dirent_t *)(uintptr_t)&dirp->dd_buf[0])->d_off = loc;
74	}
75	lmutex_unlock(&pdirp->dd_lock);
76}
77
78#else	/* _LP64 */
79
80/*
81 * Note: Instead of making this function static, we reduce it to local
82 * scope in the mapfile. That allows the linker to prevent it from
83 * appearing in the .SUNW_dynsymsort section.
84 */
85void
86seekdir64(DIR *dirp, off64_t loc)
87{
88	private_DIR	*pdirp = (private_DIR *)(uintptr_t)dirp;
89	dirent64_t	*dp64;
90	off64_t		off = 0;
91
92	lmutex_lock(&pdirp->dd_lock);
93	if (lseek64(dirp->dd_fd, 0, SEEK_CUR) != 0) {
94		dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
95		/* was converted by readdir and needs to be reversed */
96		if (dp64->d_ino == (ino64_t)-1) {
97			dirent_t *dp32;
98
99			dp32 = (dirent_t *)((uintptr_t)dp64 + sizeof (ino64_t));
100			dp64->d_ino = (ino64_t)dp32->d_ino;
101			dp64->d_off = (off64_t)dp32->d_off;
102			dp64->d_reclen = (unsigned short)(dp32->d_reclen +
103			    ((char *)&dp64->d_off - (char *)dp64));
104		}
105		off = dp64->d_off;
106	}
107	if (off != loc) {
108		dirp->dd_loc = 0;
109		(void) lseek64(dirp->dd_fd, loc, SEEK_SET);
110		dirp->dd_size = 0;
111
112		/*
113		 * Save seek offset in d_off field, in case telldir
114		 * follows seekdir with no intervening call to readdir
115		 */
116		((dirent64_t *)(uintptr_t)&dirp->dd_buf[0])->d_off = loc;
117	}
118	lmutex_unlock(&pdirp->dd_lock);
119}
120
121void
122seekdir(DIR *dirp, long loc)
123{
124	seekdir64(dirp, (off64_t)(uint32_t)loc);
125}
126
127#endif	/* _LP64 */
128