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
52 void
seekdir(DIR * dirp,long loc)53 seekdir(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 */
85 void
seekdir64(DIR * dirp,off64_t loc)86 seekdir64(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
121 void
seekdir(DIR * dirp,long loc)122 seekdir(DIR *dirp, long loc)
123 {
124 seekdir64(dirp, (off64_t)(uint32_t)loc);
125 }
126
127 #endif /* _LP64 */
128