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