4 * Copyright (C) 1995 Linus Torvalds
7 #include <linux/stddef.h>
8 #include <linux/kernel.h>
9 #include <linux/export.h>
10 #include <linux/time.h>
12 #include <linux/errno.h>
13 #include <linux/stat.h>
14 #include <linux/file.h>
16 #include <linux/dirent.h>
17 #include <linux/security.h>
18 #include <linux/syscalls.h>
19 #include <linux/unistd.h>
21 #include <asm/uaccess.h>
23 int iterate_dir(struct file
*file
, struct dir_context
*ctx
)
25 struct inode
*inode
= file_inode(file
);
27 if (!file
->f_op
|| !file
->f_op
->iterate
)
30 res
= security_file_permission(file
, MAY_READ
);
34 res
= mutex_lock_killable(&inode
->i_mutex
);
39 if (!IS_DEADDIR(inode
)) {
40 ctx
->pos
= file
->f_pos
;
41 res
= file
->f_op
->iterate(file
, ctx
);
42 file
->f_pos
= ctx
->pos
;
45 mutex_unlock(&inode
->i_mutex
);
49 EXPORT_SYMBOL(iterate_dir
);
52 * Traditional linux readdir() handling..
54 * "count=1" is a special case, meaning that the buffer is one
55 * dirent-structure in size and that the code can't handle more
56 * anyway. Thus the special "fillonedir()" function for that
57 * case (the low-level handlers don't need to care about this).
60 #ifdef __ARCH_WANT_OLD_READDIR
62 struct old_linux_dirent
{
64 unsigned long d_offset
;
65 unsigned short d_namlen
;
69 struct readdir_callback
{
70 struct dir_context ctx
;
71 struct old_linux_dirent __user
* dirent
;
75 static int fillonedir(void * __buf
, const char * name
, int namlen
, loff_t offset
,
76 u64 ino
, unsigned int d_type
)
78 struct readdir_callback
*buf
= (struct readdir_callback
*) __buf
;
79 struct old_linux_dirent __user
* dirent
;
85 if (sizeof(d_ino
) < sizeof(ino
) && d_ino
!= ino
) {
86 buf
->result
= -EOVERFLOW
;
91 if (!access_ok(VERIFY_WRITE
, dirent
,
92 (unsigned long)(dirent
->d_name
+ namlen
+ 1) -
93 (unsigned long)dirent
))
95 if ( __put_user(d_ino
, &dirent
->d_ino
) ||
96 __put_user(offset
, &dirent
->d_offset
) ||
97 __put_user(namlen
, &dirent
->d_namlen
) ||
98 __copy_to_user(dirent
->d_name
, name
, namlen
) ||
99 __put_user(0, dirent
->d_name
+ namlen
))
103 buf
->result
= -EFAULT
;
107 SYSCALL_DEFINE3(old_readdir
, unsigned int, fd
,
108 struct old_linux_dirent __user
*, dirent
, unsigned int, count
)
111 struct fd f
= fdget(fd
);
112 struct readdir_callback buf
= {
113 .ctx
.actor
= fillonedir
,
120 error
= iterate_dir(f
.file
, &buf
.ctx
);
128 #endif /* __ARCH_WANT_OLD_READDIR */
131 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
134 struct linux_dirent
{
137 unsigned short d_reclen
;
141 struct getdents_callback
{
142 struct dir_context ctx
;
143 struct linux_dirent __user
* current_dir
;
144 struct linux_dirent __user
* previous
;
149 static int filldir(void * __buf
, const char * name
, int namlen
, loff_t offset
,
150 u64 ino
, unsigned int d_type
)
152 struct linux_dirent __user
* dirent
;
153 struct getdents_callback
* buf
= (struct getdents_callback
*) __buf
;
155 int reclen
= ALIGN(offsetof(struct linux_dirent
, d_name
) + namlen
+ 2,
158 buf
->error
= -EINVAL
; /* only used if we fail.. */
159 if (reclen
> buf
->count
)
162 if (sizeof(d_ino
) < sizeof(ino
) && d_ino
!= ino
) {
163 buf
->error
= -EOVERFLOW
;
166 dirent
= buf
->previous
;
168 if (__put_user(offset
, &dirent
->d_off
))
171 dirent
= buf
->current_dir
;
172 if (__put_user(d_ino
, &dirent
->d_ino
))
174 if (__put_user(reclen
, &dirent
->d_reclen
))
176 if (copy_to_user(dirent
->d_name
, name
, namlen
))
178 if (__put_user(0, dirent
->d_name
+ namlen
))
180 if (__put_user(d_type
, (char __user
*) dirent
+ reclen
- 1))
182 buf
->previous
= dirent
;
183 dirent
= (void __user
*)dirent
+ reclen
;
184 buf
->current_dir
= dirent
;
185 buf
->count
-= reclen
;
188 buf
->error
= -EFAULT
;
192 SYSCALL_DEFINE3(getdents
, unsigned int, fd
,
193 struct linux_dirent __user
*, dirent
, unsigned int, count
)
196 struct linux_dirent __user
* lastdirent
;
197 struct getdents_callback buf
= {
198 .ctx
.actor
= filldir
,
200 .current_dir
= dirent
204 if (!access_ok(VERIFY_WRITE
, dirent
, count
))
211 error
= iterate_dir(f
.file
, &buf
.ctx
);
214 lastdirent
= buf
.previous
;
216 if (put_user(buf
.ctx
.pos
, &lastdirent
->d_off
))
219 error
= count
- buf
.count
;
225 struct getdents_callback64
{
226 struct dir_context ctx
;
227 struct linux_dirent64 __user
* current_dir
;
228 struct linux_dirent64 __user
* previous
;
233 static int filldir64(void * __buf
, const char * name
, int namlen
, loff_t offset
,
234 u64 ino
, unsigned int d_type
)
236 struct linux_dirent64 __user
*dirent
;
237 struct getdents_callback64
* buf
= (struct getdents_callback64
*) __buf
;
238 int reclen
= ALIGN(offsetof(struct linux_dirent64
, d_name
) + namlen
+ 1,
241 buf
->error
= -EINVAL
; /* only used if we fail.. */
242 if (reclen
> buf
->count
)
244 dirent
= buf
->previous
;
246 if (__put_user(offset
, &dirent
->d_off
))
249 dirent
= buf
->current_dir
;
250 if (__put_user(ino
, &dirent
->d_ino
))
252 if (__put_user(0, &dirent
->d_off
))
254 if (__put_user(reclen
, &dirent
->d_reclen
))
256 if (__put_user(d_type
, &dirent
->d_type
))
258 if (copy_to_user(dirent
->d_name
, name
, namlen
))
260 if (__put_user(0, dirent
->d_name
+ namlen
))
262 buf
->previous
= dirent
;
263 dirent
= (void __user
*)dirent
+ reclen
;
264 buf
->current_dir
= dirent
;
265 buf
->count
-= reclen
;
268 buf
->error
= -EFAULT
;
272 SYSCALL_DEFINE3(getdents64
, unsigned int, fd
,
273 struct linux_dirent64 __user
*, dirent
, unsigned int, count
)
276 struct linux_dirent64 __user
* lastdirent
;
277 struct getdents_callback64 buf
= {
278 .ctx
.actor
= filldir64
,
280 .current_dir
= dirent
284 if (!access_ok(VERIFY_WRITE
, dirent
, count
))
291 error
= iterate_dir(f
.file
, &buf
.ctx
);
294 lastdirent
= buf
.previous
;
296 typeof(lastdirent
->d_off
) d_off
= buf
.ctx
.pos
;
297 if (__put_user(d_off
, &lastdirent
->d_off
))
300 error
= count
- buf
.count
;
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