blob: fee38e04fae4ab09440c05808e539f72133c6976 [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
Kevin Winchester85c9fe82010-08-09 17:20:22 -07007#include <linux/stddef.h>
Milind Arun Choudhary022a1692007-05-08 00:29:02 -07008#include <linux/kernel.h>
Paul Gortmaker630d9c42011-11-16 23:57:37 -05009#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/time.h>
11#include <linux/mm.h>
12#include <linux/errno.h>
13#include <linux/stat.h>
14#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#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{
Al Viro496ad9a2013-01-23 17:07:38 -050025 struct inode *inode = file_inode(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 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
Liam R. Howlettda784512007-12-06 17:39:54 -050034 res = mutex_lock_killable(&inode->i_mutex);
35 if (res)
36 goto out;
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 res = -ENOENT;
39 if (!IS_DEADDIR(inode)) {
40 res = file->f_op->readdir(file, buf, filler);
41 file_accessed(file);
42 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080043 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044out:
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 */
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;
Al Viro2903ff02012-08-28 12:52:22 -0400109 struct fd f = fdget(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 struct readdir_callback buf;
111
Al Viro2903ff02012-08-28 12:52:22 -0400112 if (!f.file)
Al Viro863ced72012-04-21 18:40:32 -0400113 return -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115 buf.result = 0;
116 buf.dirent = dirent;
117
Al Viro2903ff02012-08-28 12:52:22 -0400118 error = vfs_readdir(f.file, fillonedir, &buf);
Al Viro53c9c5c2008-08-24 07:29:52 -0400119 if (buf.result)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 error = buf.result;
121
Al Viro2903ff02012-08-28 12:52:22 -0400122 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 return error;
124}
125
126#endif /* __ARCH_WANT_OLD_READDIR */
127
128/*
129 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
130 * interface.
131 */
132struct linux_dirent {
133 unsigned long d_ino;
134 unsigned long d_off;
135 unsigned short d_reclen;
136 char d_name[1];
137};
138
139struct getdents_callback {
140 struct linux_dirent __user * current_dir;
141 struct linux_dirent __user * previous;
142 int count;
143 int error;
144};
145
146static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700147 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148{
149 struct linux_dirent __user * dirent;
150 struct getdents_callback * buf = (struct getdents_callback *) __buf;
David Howellsafefdbb2006-10-03 01:13:46 -0700151 unsigned long d_ino;
Kevin Winchester85c9fe82010-08-09 17:20:22 -0700152 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
153 sizeof(long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
155 buf->error = -EINVAL; /* only used if we fail.. */
156 if (reclen > buf->count)
157 return -EINVAL;
David Howellsafefdbb2006-10-03 01:13:46 -0700158 d_ino = ino;
Al Viro8f3f6552008-08-12 00:28:24 -0400159 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
160 buf->error = -EOVERFLOW;
David Howellsafefdbb2006-10-03 01:13:46 -0700161 return -EOVERFLOW;
Al Viro8f3f6552008-08-12 00:28:24 -0400162 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 dirent = buf->previous;
164 if (dirent) {
165 if (__put_user(offset, &dirent->d_off))
166 goto efault;
167 }
168 dirent = buf->current_dir;
David Howellsafefdbb2006-10-03 01:13:46 -0700169 if (__put_user(d_ino, &dirent->d_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 goto efault;
171 if (__put_user(reclen, &dirent->d_reclen))
172 goto efault;
173 if (copy_to_user(dirent->d_name, name, namlen))
174 goto efault;
175 if (__put_user(0, dirent->d_name + namlen))
176 goto efault;
177 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
178 goto efault;
179 buf->previous = dirent;
180 dirent = (void __user *)dirent + reclen;
181 buf->current_dir = dirent;
182 buf->count -= reclen;
183 return 0;
184efault:
185 buf->error = -EFAULT;
186 return -EFAULT;
187}
188
Heiko Carstens20f37032009-01-14 14:14:23 +0100189SYSCALL_DEFINE3(getdents, unsigned int, fd,
190 struct linux_dirent __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191{
Al Viro2903ff02012-08-28 12:52:22 -0400192 struct fd f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 struct linux_dirent __user * lastdirent;
194 struct getdents_callback buf;
195 int error;
196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 if (!access_ok(VERIFY_WRITE, dirent, count))
Al Viro863ced72012-04-21 18:40:32 -0400198 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
Al Viro2903ff02012-08-28 12:52:22 -0400200 f = fdget(fd);
201 if (!f.file)
Al Viro863ced72012-04-21 18:40:32 -0400202 return -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 buf.current_dir = dirent;
205 buf.previous = NULL;
206 buf.count = count;
207 buf.error = 0;
208
Al Viro2903ff02012-08-28 12:52:22 -0400209 error = vfs_readdir(f.file, filldir, &buf);
Al Viro53c9c5c2008-08-24 07:29:52 -0400210 if (error >= 0)
211 error = buf.error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 lastdirent = buf.previous;
213 if (lastdirent) {
Al Viro2903ff02012-08-28 12:52:22 -0400214 if (put_user(f.file->f_pos, &lastdirent->d_off))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 error = -EFAULT;
216 else
217 error = count - buf.count;
218 }
Al Viro2903ff02012-08-28 12:52:22 -0400219 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 return error;
221}
222
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223struct getdents_callback64 {
224 struct linux_dirent64 __user * current_dir;
225 struct linux_dirent64 __user * previous;
226 int count;
227 int error;
228};
229
230static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700231 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232{
233 struct linux_dirent64 __user *dirent;
234 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
Kevin Winchester85c9fe82010-08-09 17:20:22 -0700235 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
236 sizeof(u64));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 buf->error = -EINVAL; /* only used if we fail.. */
239 if (reclen > buf->count)
240 return -EINVAL;
241 dirent = buf->previous;
242 if (dirent) {
243 if (__put_user(offset, &dirent->d_off))
244 goto efault;
245 }
246 dirent = buf->current_dir;
247 if (__put_user(ino, &dirent->d_ino))
248 goto efault;
249 if (__put_user(0, &dirent->d_off))
250 goto efault;
251 if (__put_user(reclen, &dirent->d_reclen))
252 goto efault;
253 if (__put_user(d_type, &dirent->d_type))
254 goto efault;
255 if (copy_to_user(dirent->d_name, name, namlen))
256 goto efault;
257 if (__put_user(0, dirent->d_name + namlen))
258 goto efault;
259 buf->previous = dirent;
260 dirent = (void __user *)dirent + reclen;
261 buf->current_dir = dirent;
262 buf->count -= reclen;
263 return 0;
264efault:
265 buf->error = -EFAULT;
266 return -EFAULT;
267}
268
Heiko Carstens20f37032009-01-14 14:14:23 +0100269SYSCALL_DEFINE3(getdents64, unsigned int, fd,
270 struct linux_dirent64 __user *, dirent, unsigned int, count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271{
Al Viro2903ff02012-08-28 12:52:22 -0400272 struct fd f;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 struct linux_dirent64 __user * lastdirent;
274 struct getdents_callback64 buf;
275 int error;
276
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 if (!access_ok(VERIFY_WRITE, dirent, count))
Al Viro863ced72012-04-21 18:40:32 -0400278 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
Al Viro2903ff02012-08-28 12:52:22 -0400280 f = fdget(fd);
281 if (!f.file)
Al Viro863ced72012-04-21 18:40:32 -0400282 return -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284 buf.current_dir = dirent;
285 buf.previous = NULL;
286 buf.count = count;
287 buf.error = 0;
288
Al Viro2903ff02012-08-28 12:52:22 -0400289 error = vfs_readdir(f.file, filldir64, &buf);
Al Viro53c9c5c2008-08-24 07:29:52 -0400290 if (error >= 0)
291 error = buf.error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 lastdirent = buf.previous;
293 if (lastdirent) {
Al Viro2903ff02012-08-28 12:52:22 -0400294 typeof(lastdirent->d_off) d_off = f.file->f_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 if (__put_user(d_off, &lastdirent->d_off))
Al Viro53c9c5c2008-08-24 07:29:52 -0400296 error = -EFAULT;
297 else
298 error = count - buf.count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 }
Al Viro2903ff02012-08-28 12:52:22 -0400300 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 return error;
302}