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CommitLineData
1da177e4
LT
1/*
2 * linux/fs/readdir.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
85c9fe8f 7#include <linux/stddef.h>
022a1692 8#include <linux/kernel.h>
630d9c47 9#include <linux/export.h>
1da177e4
LT
10#include <linux/time.h>
11#include <linux/mm.h>
12#include <linux/errno.h>
13#include <linux/stat.h>
14#include <linux/file.h>
1da177e4
LT
15#include <linux/fs.h>
16#include <linux/dirent.h>
17#include <linux/security.h>
18#include <linux/syscalls.h>
19#include <linux/unistd.h>
20
21#include <asm/uaccess.h>
22
23int vfs_readdir(struct file *file, filldir_t filler, void *buf)
24{
0f7fc9e4 25 struct inode *inode = file->f_path.dentry->d_inode;
1da177e4
LT
26 int res = -ENOTDIR;
27 if (!file->f_op || !file->f_op->readdir)
28 goto out;
29
30 res = security_file_permission(file, MAY_READ);
31 if (res)
32 goto out;
33
da784511
LH
34 res = mutex_lock_killable(&inode->i_mutex);
35 if (res)
36 goto out;
37
1da177e4
LT
38 res = -ENOENT;
39 if (!IS_DEADDIR(inode)) {
40 res = file->f_op->readdir(file, buf, filler);
41 file_accessed(file);
42 }
1b1dcc1b 43 mutex_unlock(&inode->i_mutex);
1da177e4
LT
44out:
45 return res;
46}
47
48EXPORT_SYMBOL(vfs_readdir);
49
50/*
51 * Traditional linux readdir() handling..
52 *
53 * "count=1" is a special case, meaning that the buffer is one
54 * dirent-structure in size and that the code can't handle more
55 * anyway. Thus the special "fillonedir()" function for that
56 * case (the low-level handlers don't need to care about this).
57 */
1da177e4
LT
58
59#ifdef __ARCH_WANT_OLD_READDIR
60
61struct old_linux_dirent {
62 unsigned long d_ino;
63 unsigned long d_offset;
64 unsigned short d_namlen;
65 char d_name[1];
66};
67
68struct readdir_callback {
69 struct old_linux_dirent __user * dirent;
70 int result;
71};
72
73static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2 74 u64 ino, unsigned int d_type)
1da177e4
LT
75{
76 struct readdir_callback * buf = (struct readdir_callback *) __buf;
77 struct old_linux_dirent __user * dirent;
afefdbb2 78 unsigned long d_ino;
1da177e4
LT
79
80 if (buf->result)
81 return -EINVAL;
afefdbb2 82 d_ino = ino;
8f3f655d
AV
83 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
84 buf->result = -EOVERFLOW;
afefdbb2 85 return -EOVERFLOW;
8f3f655d 86 }
1da177e4
LT
87 buf->result++;
88 dirent = buf->dirent;
89 if (!access_ok(VERIFY_WRITE, dirent,
90 (unsigned long)(dirent->d_name + namlen + 1) -
91 (unsigned long)dirent))
92 goto efault;
afefdbb2 93 if ( __put_user(d_ino, &dirent->d_ino) ||
1da177e4
LT
94 __put_user(offset, &dirent->d_offset) ||
95 __put_user(namlen, &dirent->d_namlen) ||
96 __copy_to_user(dirent->d_name, name, namlen) ||
97 __put_user(0, dirent->d_name + namlen))
98 goto efault;
99 return 0;
100efault:
101 buf->result = -EFAULT;
102 return -EFAULT;
103}
104
d4e82042
HC
105SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
106 struct old_linux_dirent __user *, dirent, unsigned int, count)
1da177e4
LT
107{
108 int error;
109 struct file * file;
110 struct readdir_callback buf;
863ced7f 111 int fput_needed;
1da177e4 112
863ced7f 113 file = fget_light(fd, &fput_needed);
1da177e4 114 if (!file)
863ced7f 115 return -EBADF;
1da177e4
LT
116
117 buf.result = 0;
118 buf.dirent = dirent;
119
120 error = vfs_readdir(file, fillonedir, &buf);
53c9c5c0 121 if (buf.result)
1da177e4
LT
122 error = buf.result;
123
863ced7f 124 fput_light(file, fput_needed);
1da177e4
LT
125 return error;
126}
127
128#endif /* __ARCH_WANT_OLD_READDIR */
129
130/*
131 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
132 * interface.
133 */
134struct linux_dirent {
135 unsigned long d_ino;
136 unsigned long d_off;
137 unsigned short d_reclen;
138 char d_name[1];
139};
140
141struct getdents_callback {
142 struct linux_dirent __user * current_dir;
143 struct linux_dirent __user * previous;
144 int count;
145 int error;
146};
147
148static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2 149 u64 ino, unsigned int d_type)
1da177e4
LT
150{
151 struct linux_dirent __user * dirent;
152 struct getdents_callback * buf = (struct getdents_callback *) __buf;
afefdbb2 153 unsigned long d_ino;
85c9fe8f
KW
154 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
155 sizeof(long));
1da177e4
LT
156
157 buf->error = -EINVAL; /* only used if we fail.. */
158 if (reclen > buf->count)
159 return -EINVAL;
afefdbb2 160 d_ino = ino;
8f3f655d
AV
161 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
162 buf->error = -EOVERFLOW;
afefdbb2 163 return -EOVERFLOW;
8f3f655d 164 }
1da177e4
LT
165 dirent = buf->previous;
166 if (dirent) {
167 if (__put_user(offset, &dirent->d_off))
168 goto efault;
169 }
170 dirent = buf->current_dir;
afefdbb2 171 if (__put_user(d_ino, &dirent->d_ino))
1da177e4
LT
172 goto efault;
173 if (__put_user(reclen, &dirent->d_reclen))
174 goto efault;
175 if (copy_to_user(dirent->d_name, name, namlen))
176 goto efault;
177 if (__put_user(0, dirent->d_name + namlen))
178 goto efault;
179 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
180 goto efault;
181 buf->previous = dirent;
182 dirent = (void __user *)dirent + reclen;
183 buf->current_dir = dirent;
184 buf->count -= reclen;
185 return 0;
186efault:
187 buf->error = -EFAULT;
188 return -EFAULT;
189}
190
20f37034
HC
191SYSCALL_DEFINE3(getdents, unsigned int, fd,
192 struct linux_dirent __user *, dirent, unsigned int, count)
1da177e4
LT
193{
194 struct file * file;
195 struct linux_dirent __user * lastdirent;
196 struct getdents_callback buf;
863ced7f 197 int fput_needed;
1da177e4
LT
198 int error;
199
1da177e4 200 if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f 201 return -EFAULT;
1da177e4 202
863ced7f 203 file = fget_light(fd, &fput_needed);
1da177e4 204 if (!file)
863ced7f 205 return -EBADF;
1da177e4
LT
206
207 buf.current_dir = dirent;
208 buf.previous = NULL;
209 buf.count = count;
210 buf.error = 0;
211
212 error = vfs_readdir(file, filldir, &buf);
53c9c5c0
AV
213 if (error >= 0)
214 error = buf.error;
1da177e4
LT
215 lastdirent = buf.previous;
216 if (lastdirent) {
217 if (put_user(file->f_pos, &lastdirent->d_off))
218 error = -EFAULT;
219 else
220 error = count - buf.count;
221 }
863ced7f 222 fput_light(file, fput_needed);
1da177e4
LT
223 return error;
224}
225
1da177e4
LT
226struct getdents_callback64 {
227 struct linux_dirent64 __user * current_dir;
228 struct linux_dirent64 __user * previous;
229 int count;
230 int error;
231};
232
233static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
afefdbb2 234 u64 ino, unsigned int d_type)
1da177e4
LT
235{
236 struct linux_dirent64 __user *dirent;
237 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
85c9fe8f
KW
238 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
239 sizeof(u64));
1da177e4
LT
240
241 buf->error = -EINVAL; /* only used if we fail.. */
242 if (reclen > buf->count)
243 return -EINVAL;
244 dirent = buf->previous;
245 if (dirent) {
246 if (__put_user(offset, &dirent->d_off))
247 goto efault;
248 }
249 dirent = buf->current_dir;
250 if (__put_user(ino, &dirent->d_ino))
251 goto efault;
252 if (__put_user(0, &dirent->d_off))
253 goto efault;
254 if (__put_user(reclen, &dirent->d_reclen))
255 goto efault;
256 if (__put_user(d_type, &dirent->d_type))
257 goto efault;
258 if (copy_to_user(dirent->d_name, name, namlen))
259 goto efault;
260 if (__put_user(0, dirent->d_name + namlen))
261 goto efault;
262 buf->previous = dirent;
263 dirent = (void __user *)dirent + reclen;
264 buf->current_dir = dirent;
265 buf->count -= reclen;
266 return 0;
267efault:
268 buf->error = -EFAULT;
269 return -EFAULT;
270}
271
20f37034
HC
272SYSCALL_DEFINE3(getdents64, unsigned int, fd,
273 struct linux_dirent64 __user *, dirent, unsigned int, count)
1da177e4
LT
274{
275 struct file * file;
276 struct linux_dirent64 __user * lastdirent;
277 struct getdents_callback64 buf;
863ced7f 278 int fput_needed;
1da177e4
LT
279 int error;
280
1da177e4 281 if (!access_ok(VERIFY_WRITE, dirent, count))
863ced7f 282 return -EFAULT;
1da177e4 283
863ced7f 284 file = fget_light(fd, &fput_needed);
1da177e4 285 if (!file)
863ced7f 286 return -EBADF;
1da177e4
LT
287
288 buf.current_dir = dirent;
289 buf.previous = NULL;
290 buf.count = count;
291 buf.error = 0;
292
293 error = vfs_readdir(file, filldir64, &buf);
53c9c5c0
AV
294 if (error >= 0)
295 error = buf.error;
1da177e4
LT
296 lastdirent = buf.previous;
297 if (lastdirent) {
298 typeof(lastdirent->d_off) d_off = file->f_pos;
1da177e4 299 if (__put_user(d_off, &lastdirent->d_off))
53c9c5c0
AV
300 error = -EFAULT;
301 else
302 error = count - buf.count;
1da177e4 303 }
863ced7f 304 fput_light(file, fput_needed);
1da177e4
LT
305 return error;
306}