1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
/* Read a directory. Linux LFS version.
Copyright (C) 1997-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* When _DIRENT_MATCHES_DIRENT64 is defined we can alias 'readdir64' to
'readdir'. However the function signatures are not equal due
different return types, so we need to suppress {__}readdir so weak
and strong alias do not throw conflicting types errors. */
#define readdir __no_readdir_decl
#define __readdir __no___readdir_decl
#include <dirent.h>
#undef __readdir
#undef readdir
/* Read a directory entry from DIRP. No locking. */
static struct dirent64 *
__readdir64_unlocked (DIR *dirp)
{
struct dirent64 *dp;
int saved_errno = errno;
if (dirp->offset >= dirp->size)
{
/* We've emptied out our buffer. Refill it. */
size_t maxread = dirp->allocation;
ssize_t bytes;
bytes = __getdents64 (dirp->fd, dirp->data, maxread);
if (bytes <= 0)
{
/* Linux may fail with ENOENT on some file systems if the
directory inode is marked as dead (deleted). POSIX
treats this as a regular end-of-directory condition, so
do not set errno in that case, to indicate success. */
if (bytes == 0 || errno == ENOENT)
__set_errno (saved_errno);
return NULL;
}
dirp->size = (size_t) bytes;
/* Reset the offset into the buffer. */
dirp->offset = 0;
}
dp = (struct dirent64 *) &dirp->data[dirp->offset];
dirp->offset += dp->d_reclen;
dirp->filepos = dp->d_off;
return dp;
}
/* Read a directory entry from DIRP. */
struct dirent64 *
__readdir64 (DIR *dirp)
{
__libc_lock_lock (dirp->lock);
struct dirent64 *dp = __readdir64_unlocked (dirp);
__libc_lock_unlock (dirp->lock);
return dp;
}
libc_hidden_def (__readdir64)
#if _DIRENT_MATCHES_DIRENT64
strong_alias (__readdir64, __readdir)
weak_alias (__readdir64, readdir64)
weak_alias (__readdir64, readdir)
#else
/* The compat code expects the 'struct direct' with d_ino being a __ino_t
instead of __ino64_t. */
# include <shlib-compat.h>
# if IS_IN(rtld)
weak_alias (__readdir64, readdir64)
# else
versioned_symbol (libc, __readdir64, readdir64, GLIBC_2_2);
# endif
# if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2)
# include <olddirent.h>
attribute_compat_text_section
struct __old_dirent64 *
__old_readdir64 (DIR *dirp)
{
struct __old_dirent64 *dp;
int saved_errno = errno;
__libc_lock_lock (dirp->lock);
while (1)
{
errno = 0;
struct dirent64 *newdp = __readdir64_unlocked (dirp);
if (newdp == NULL)
{
if (errno == 0 && dirp->errcode != 0)
__set_errno (dirp->errcode);
else if (errno == 0)
__set_errno (saved_errno);
dp = NULL;
break;
}
/* Convert to the target layout. Use a separate struct and
memcpy to side-step aliasing issues. */
struct __old_dirent64 result;
result.d_ino = newdp->d_ino;
result.d_off = newdp->d_off;
result.d_reclen = newdp->d_reclen;
result.d_type = newdp->d_type;
/* Check for ino_t overflow. */
if (__glibc_unlikely (result.d_ino != newdp->d_ino))
{
dirp->errcode = ENAMETOOLONG;
continue;
}
/* Overwrite the fixed-sized part. */
dp = (struct __old_dirent64 *) newdp;
memcpy (dp, &result, offsetof (struct __old_dirent64, d_name));
/* Move the name. */
_Static_assert (offsetof (struct __old_dirent64, d_name)
<= offsetof (struct dirent64, d_name),
"old struct must be smaller");
if (offsetof (struct __old_dirent64, d_name)
!= offsetof (struct dirent64, d_name))
memmove (dp->d_name, newdp->d_name, strlen (newdp->d_name) + 1);
__set_errno (saved_errno);
break;
}
__libc_lock_unlock (dirp->lock);
return dp;
}
libc_hidden_def (__old_readdir64)
compat_symbol (libc, __old_readdir64, readdir64, GLIBC_2_1);
# endif /* SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2) */
#endif /* _DIRENT_MATCHES_DIRENT64 */
|
