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 /*
31 * seekdir -- C library extension routine
32 */
33
34 #include <sys/feature_tests.h>
35
36 #if !defined(_LP64)
37 #pragma weak _seekdir64 = seekdir64
38 #endif
39 #pragma weak _seekdir = seekdir
40
41 #include "lint.h"
42 #include "libc.h"
43 #include <mtlib.h>
44 #include <dirent.h>
45 #include <fcntl.h>
46 #include <unistd.h>
47
48 #ifdef _LP64
49
50 void
seekdir(DIR * dirp,long loc)51 seekdir(DIR *dirp, long loc)
52 {
53 private_DIR *pdirp = (private_DIR *)dirp;
54 dirent_t *dp;
55 off_t off = 0;
56
57 lmutex_lock(&pdirp->dd_lock);
58 if (lseek(dirp->dd_fd, 0, SEEK_CUR) != 0) {
59 dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
60 off = dp->d_off;
61 }
62 if (off != loc) {
63 dirp->dd_loc = 0;
64 (void) lseek(dirp->dd_fd, loc, SEEK_SET);
65 dirp->dd_size = 0;
66
67 /*
68 * Save seek offset in d_off field, in case telldir
69 * follows seekdir with no intervening call to readdir
70 */
71 ((dirent_t *)(uintptr_t)&dirp->dd_buf[0])->d_off = loc;
72 }
73 lmutex_unlock(&pdirp->dd_lock);
74 }
75
76 #else /* _LP64 */
77
78 /*
79 * Note: Instead of making this function static, we reduce it to local
80 * scope in the mapfile. That allows the linker to prevent it from
81 * appearing in the .SUNW_dynsymsort section.
82 */
83 void
seekdir64(DIR * dirp,off64_t loc)84 seekdir64(DIR *dirp, off64_t loc)
85 {
86 private_DIR *pdirp = (private_DIR *)(uintptr_t)dirp;
87 dirent64_t *dp64;
88 off64_t off = 0;
89
90 lmutex_lock(&pdirp->dd_lock);
91 if (lseek64(dirp->dd_fd, 0, SEEK_CUR) != 0) {
92 dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
93 /* was converted by readdir and needs to be reversed */
94 if (dp64->d_ino == (ino64_t)-1) {
95 dirent_t *dp32;
96
97 dp32 = (dirent_t *)((uintptr_t)dp64 + sizeof (ino64_t));
98 dp64->d_ino = (ino64_t)dp32->d_ino;
99 dp64->d_off = (off64_t)dp32->d_off;
100 dp64->d_reclen = (unsigned short)(dp32->d_reclen +
101 ((char *)&dp64->d_off - (char *)dp64));
102 }
103 off = dp64->d_off;
104 }
105 if (off != loc) {
106 dirp->dd_loc = 0;
107 (void) lseek64(dirp->dd_fd, loc, SEEK_SET);
108 dirp->dd_size = 0;
109
110 /*
111 * Save seek offset in d_off field, in case telldir
112 * follows seekdir with no intervening call to readdir
113 */
114 ((dirent64_t *)(uintptr_t)&dirp->dd_buf[0])->d_off = loc;
115 }
116 lmutex_unlock(&pdirp->dd_lock);
117 }
118
119 void
seekdir(DIR * dirp,long loc)120 seekdir(DIR *dirp, long loc)
121 {
122 seekdir64(dirp, (off64_t)(uint32_t)loc);
123 }
124
125 #endif /* _LP64 */
126