blob: 7723401f8d8b58d43b780ed1d3ff1e5f38303b0d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/readdir.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
Milind Arun Choudhary022a1692007-05-08 00:29:02 -07007#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#include <linux/module.h>
9#include <linux/time.h>
10#include <linux/mm.h>
11#include <linux/errno.h>
12#include <linux/stat.h>
13#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/fs.h>
15#include <linux/dirent.h>
16#include <linux/security.h>
17#include <linux/syscalls.h>
18#include <linux/unistd.h>
19
20#include <asm/uaccess.h>
21
22int vfs_readdir(struct file *file, filldir_t filler, void *buf)
23{
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -080024 struct inode *inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 int res = -ENOTDIR;
26 if (!file->f_op || !file->f_op->readdir)
27 goto out;
28
29 res = security_file_permission(file, MAY_READ);
30 if (res)
31 goto out;
32
Liam R. Howlettda784512007-12-06 17:39:54 -050033 res = mutex_lock_killable(&inode->i_mutex);
34 if (res)
35 goto out;
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 res = -ENOENT;
38 if (!IS_DEADDIR(inode)) {
39 res = file->f_op->readdir(file, buf, filler);
40 file_accessed(file);
41 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080042 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043out:
44 return res;
45}
46
47EXPORT_SYMBOL(vfs_readdir);
48
49/*
50 * Traditional linux readdir() handling..
51 *
52 * "count=1" is a special case, meaning that the buffer is one
53 * dirent-structure in size and that the code can't handle more
54 * anyway. Thus the special "fillonedir()" function for that
55 * case (the low-level handlers don't need to care about this).
56 */
57#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
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,
David Howellsafefdbb2006-10-03 01:13:46 -070074 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -070075{
76 struct readdir_callback * buf = (struct readdir_callback *) __buf;
77 struct old_linux_dirent __user * dirent;
David Howellsafefdbb2006-10-03 01:13:46 -070078 unsigned long d_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80 if (buf->result)
81 return -EINVAL;
David Howellsafefdbb2006-10-03 01:13:46 -070082 d_ino = ino;
Al Viro8f3f6552008-08-12 00:28:24 -040083 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
84 buf->result = -EOVERFLOW;
David Howellsafefdbb2006-10-03 01:13:46 -070085 return -EOVERFLOW;
Al Viro8f3f6552008-08-12 00:28:24 -040086 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 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;
David Howellsafefdbb2006-10-03 01:13:46 -070093 if ( __put_user(d_ino, &dirent->d_ino) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 __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
Heiko Carstensd4e82042009-01-14 14:14:34 +0100105SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
106 struct old_linux_dirent __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
108 int error;
109 struct file * file;
110 struct readdir_callback buf;
111
112 error = -EBADF;
113 file = fget(fd);
114 if (!file)
115 goto out;
116
117 buf.result = 0;
118 buf.dirent = dirent;
119
120 error = vfs_readdir(file, fillonedir, &buf);
Al Viro53c9c5c2008-08-24 07:29:52 -0400121 if (buf.result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 error = buf.result;
123
124 fput(file);
125out:
126 return error;
127}
128
129#endif /* __ARCH_WANT_OLD_READDIR */
130
131/*
132 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
133 * interface.
134 */
135struct linux_dirent {
136 unsigned long d_ino;
137 unsigned long d_off;
138 unsigned short d_reclen;
139 char d_name[1];
140};
141
142struct getdents_callback {
143 struct linux_dirent __user * current_dir;
144 struct linux_dirent __user * previous;
145 int count;
146 int error;
147};
148
149static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700150 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
152 struct linux_dirent __user * dirent;
153 struct getdents_callback * buf = (struct getdents_callback *) __buf;
David Howellsafefdbb2006-10-03 01:13:46 -0700154 unsigned long d_ino;
Milind Arun Choudhary022a1692007-05-08 00:29:02 -0700155 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157 buf->error = -EINVAL; /* only used if we fail.. */
158 if (reclen > buf->count)
159 return -EINVAL;
David Howellsafefdbb2006-10-03 01:13:46 -0700160 d_ino = ino;
Al Viro8f3f6552008-08-12 00:28:24 -0400161 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
162 buf->error = -EOVERFLOW;
David Howellsafefdbb2006-10-03 01:13:46 -0700163 return -EOVERFLOW;
Al Viro8f3f6552008-08-12 00:28:24 -0400164 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 dirent = buf->previous;
166 if (dirent) {
167 if (__put_user(offset, &dirent->d_off))
168 goto efault;
169 }
170 dirent = buf->current_dir;
David Howellsafefdbb2006-10-03 01:13:46 -0700171 if (__put_user(d_ino, &dirent->d_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 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
Heiko Carstens20f37032009-01-14 14:14:23 +0100191SYSCALL_DEFINE3(getdents, unsigned int, fd,
192 struct linux_dirent __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193{
194 struct file * file;
195 struct linux_dirent __user * lastdirent;
196 struct getdents_callback buf;
197 int error;
198
199 error = -EFAULT;
200 if (!access_ok(VERIFY_WRITE, dirent, count))
201 goto out;
202
203 error = -EBADF;
204 file = fget(fd);
205 if (!file)
206 goto out;
207
208 buf.current_dir = dirent;
209 buf.previous = NULL;
210 buf.count = count;
211 buf.error = 0;
212
213 error = vfs_readdir(file, filldir, &buf);
Al Viro53c9c5c2008-08-24 07:29:52 -0400214 if (error >= 0)
215 error = buf.error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 lastdirent = buf.previous;
217 if (lastdirent) {
218 if (put_user(file->f_pos, &lastdirent->d_off))
219 error = -EFAULT;
220 else
221 error = count - buf.count;
222 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 fput(file);
224out:
225 return error;
226}
227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228struct getdents_callback64 {
229 struct linux_dirent64 __user * current_dir;
230 struct linux_dirent64 __user * previous;
231 int count;
232 int error;
233};
234
235static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700236 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237{
238 struct linux_dirent64 __user *dirent;
239 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
Milind Arun Choudhary022a1692007-05-08 00:29:02 -0700240 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
242 buf->error = -EINVAL; /* only used if we fail.. */
243 if (reclen > buf->count)
244 return -EINVAL;
245 dirent = buf->previous;
246 if (dirent) {
247 if (__put_user(offset, &dirent->d_off))
248 goto efault;
249 }
250 dirent = buf->current_dir;
251 if (__put_user(ino, &dirent->d_ino))
252 goto efault;
253 if (__put_user(0, &dirent->d_off))
254 goto efault;
255 if (__put_user(reclen, &dirent->d_reclen))
256 goto efault;
257 if (__put_user(d_type, &dirent->d_type))
258 goto efault;
259 if (copy_to_user(dirent->d_name, name, namlen))
260 goto efault;
261 if (__put_user(0, dirent->d_name + namlen))
262 goto efault;
263 buf->previous = dirent;
264 dirent = (void __user *)dirent + reclen;
265 buf->current_dir = dirent;
266 buf->count -= reclen;
267 return 0;
268efault:
269 buf->error = -EFAULT;
270 return -EFAULT;
271}
272
Heiko Carstens20f37032009-01-14 14:14:23 +0100273SYSCALL_DEFINE3(getdents64, unsigned int, fd,
274 struct linux_dirent64 __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275{
276 struct file * file;
277 struct linux_dirent64 __user * lastdirent;
278 struct getdents_callback64 buf;
279 int error;
280
281 error = -EFAULT;
282 if (!access_ok(VERIFY_WRITE, dirent, count))
283 goto out;
284
285 error = -EBADF;
286 file = fget(fd);
287 if (!file)
288 goto out;
289
290 buf.current_dir = dirent;
291 buf.previous = NULL;
292 buf.count = count;
293 buf.error = 0;
294
295 error = vfs_readdir(file, filldir64, &buf);
Al Viro53c9c5c2008-08-24 07:29:52 -0400296 if (error >= 0)
297 error = buf.error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 lastdirent = buf.previous;
299 if (lastdirent) {
300 typeof(lastdirent->d_off) d_off = file->f_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 if (__put_user(d_off, &lastdirent->d_off))
Al Viro53c9c5c2008-08-24 07:29:52 -0400302 error = -EFAULT;
303 else
304 error = count - buf.count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 fput(file);
307out:
308 return error;
309}