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 * University Copyright- Copyright (c) 1982, 1986, 1988
32 * The Regents of the University of California
33 * All Rights Reserved
34 *
35 * University Acknowledgment- Portions of this document are derived from
36 * software developed by the University of California, Berkeley, and its
37 * contributors.
38 */
39
40 #pragma ident "%Z%%M% %I% %E% SMI"
41
42 /*
43 * readdir -- C library extension routine
44 */
45
46 #include <sys/feature_tests.h>
47
48 #if !defined(_LP64)
49 #pragma weak _readdir64 = readdir64
50 #endif
51 #pragma weak _readdir = readdir
52
53 #include "lint.h"
54 #include <dirent.h>
55 #include <limits.h>
56 #include <errno.h>
57 #include "libc.h"
58
59 #ifdef _LP64
60
61 dirent_t *
readdir(DIR * dirp)62 readdir(DIR *dirp)
63 {
64 dirent_t *dp; /* -> directory data */
65 int saveloc = 0;
66
67 if (dirp->dd_size != 0) {
68 dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
69 saveloc = dirp->dd_loc; /* save for possible EOF */
70 dirp->dd_loc += (int)dp->d_reclen;
71 }
72 if (dirp->dd_loc >= dirp->dd_size)
73 dirp->dd_loc = dirp->dd_size = 0;
74
75 if (dirp->dd_size == 0 && /* refill buffer */
76 (dirp->dd_size = getdents(dirp->dd_fd,
77 (dirent_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
78 if (dirp->dd_size == 0) /* This means EOF */
79 dirp->dd_loc = saveloc; /* so save for telldir */
80 return (NULL); /* error or EOF */
81 }
82
83 return ((dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc]);
84 }
85
86 #else /* _LP64 */
87
88 /*
89 * Welcome to the complicated world of large files on a small system.
90 */
91
92 dirent64_t *
readdir64(DIR * dirp)93 readdir64(DIR *dirp)
94 {
95 dirent64_t *dp64; /* -> directory data */
96 int saveloc = 0;
97
98 if (dirp->dd_size != 0) {
99 dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
100 /* was converted by readdir and needs to be reversed */
101 if (dp64->d_ino == (ino64_t)-1) {
102 dirent_t *dp32;
103
104 dp32 = (dirent_t *)(&dp64->d_off);
105 dp64->d_ino = (ino64_t)dp32->d_ino;
106 dp64->d_off = (off64_t)dp32->d_off;
107 dp64->d_reclen = (unsigned short)(dp32->d_reclen +
108 ((char *)&dp64->d_off - (char *)dp64));
109 }
110 saveloc = dirp->dd_loc; /* save for possible EOF */
111 dirp->dd_loc += (int)dp64->d_reclen;
112 }
113 if (dirp->dd_loc >= dirp->dd_size)
114 dirp->dd_loc = dirp->dd_size = 0;
115
116 if (dirp->dd_size == 0 && /* refill buffer */
117 (dirp->dd_size = getdents64(dirp->dd_fd,
118 (dirent64_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
119 if (dirp->dd_size == 0) /* This means EOF */
120 dirp->dd_loc = saveloc; /* so save for telldir */
121 return (NULL); /* error or EOF */
122 }
123
124 dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
125 return (dp64);
126 }
127
128 /*
129 * readdir now does translation of dirent64 entries into dirent entries.
130 * We rely on the fact that dirents are smaller than dirent64s and we
131 * reuse the space accordingly.
132 */
133 dirent_t *
readdir(DIR * dirp)134 readdir(DIR *dirp)
135 {
136 dirent64_t *dp64; /* -> directory data */
137 dirent_t *dp32; /* -> directory data */
138
139 if ((dp64 = readdir64(dirp)) == NULL)
140 return (NULL);
141
142 /*
143 * Make sure that the offset fits in 32 bits.
144 */
145 if (((off_t)dp64->d_off != dp64->d_off &&
146 (uint64_t)dp64->d_off > (uint64_t)UINT32_MAX) ||
147 dp64->d_ino > SIZE_MAX) {
148 errno = EOVERFLOW;
149 return (NULL);
150 }
151
152 dp32 = (dirent_t *)(&dp64->d_off);
153 dp32->d_off = (off_t)dp64->d_off;
154 dp32->d_ino = (ino_t)dp64->d_ino;
155 dp32->d_reclen = (unsigned short)(dp64->d_reclen -
156 ((char *)&dp64->d_off - (char *)dp64));
157 dp64->d_ino = (ino64_t)-1; /* flag as converted for readdir64 */
158 /* d_name d_reclen should not move */
159 return (dp32);
160 }
161 #endif /* _LP64 */
162