blob: efe52e67657719963d5ac1cd22df34e7465d4234 [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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080033 mutex_lock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 res = -ENOENT;
35 if (!IS_DEADDIR(inode)) {
36 res = file->f_op->readdir(file, buf, filler);
37 file_accessed(file);
38 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080039 mutex_unlock(&inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040out:
41 return res;
42}
43
44EXPORT_SYMBOL(vfs_readdir);
45
46/*
47 * Traditional linux readdir() handling..
48 *
49 * "count=1" is a special case, meaning that the buffer is one
50 * dirent-structure in size and that the code can't handle more
51 * anyway. Thus the special "fillonedir()" function for that
52 * case (the low-level handlers don't need to care about this).
53 */
54#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56#ifdef __ARCH_WANT_OLD_READDIR
57
58struct old_linux_dirent {
59 unsigned long d_ino;
60 unsigned long d_offset;
61 unsigned short d_namlen;
62 char d_name[1];
63};
64
65struct readdir_callback {
66 struct old_linux_dirent __user * dirent;
67 int result;
68};
69
70static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -070071 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072{
73 struct readdir_callback * buf = (struct readdir_callback *) __buf;
74 struct old_linux_dirent __user * dirent;
David Howellsafefdbb2006-10-03 01:13:46 -070075 unsigned long d_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77 if (buf->result)
78 return -EINVAL;
David Howellsafefdbb2006-10-03 01:13:46 -070079 d_ino = ino;
80 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
81 return -EOVERFLOW;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 buf->result++;
83 dirent = buf->dirent;
84 if (!access_ok(VERIFY_WRITE, dirent,
85 (unsigned long)(dirent->d_name + namlen + 1) -
86 (unsigned long)dirent))
87 goto efault;
David Howellsafefdbb2006-10-03 01:13:46 -070088 if ( __put_user(d_ino, &dirent->d_ino) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 __put_user(offset, &dirent->d_offset) ||
90 __put_user(namlen, &dirent->d_namlen) ||
91 __copy_to_user(dirent->d_name, name, namlen) ||
92 __put_user(0, dirent->d_name + namlen))
93 goto efault;
94 return 0;
95efault:
96 buf->result = -EFAULT;
97 return -EFAULT;
98}
99
100asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
101{
102 int error;
103 struct file * file;
104 struct readdir_callback buf;
105
106 error = -EBADF;
107 file = fget(fd);
108 if (!file)
109 goto out;
110
111 buf.result = 0;
112 buf.dirent = dirent;
113
114 error = vfs_readdir(file, fillonedir, &buf);
115 if (error >= 0)
116 error = buf.result;
117
118 fput(file);
119out:
120 return error;
121}
122
123#endif /* __ARCH_WANT_OLD_READDIR */
124
125/*
126 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
127 * interface.
128 */
129struct linux_dirent {
130 unsigned long d_ino;
131 unsigned long d_off;
132 unsigned short d_reclen;
133 char d_name[1];
134};
135
136struct getdents_callback {
137 struct linux_dirent __user * current_dir;
138 struct linux_dirent __user * previous;
139 int count;
140 int error;
141};
142
143static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700144 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
146 struct linux_dirent __user * dirent;
147 struct getdents_callback * buf = (struct getdents_callback *) __buf;
David Howellsafefdbb2006-10-03 01:13:46 -0700148 unsigned long d_ino;
Milind Arun Choudhary022a1692007-05-08 00:29:02 -0700149 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
151 buf->error = -EINVAL; /* only used if we fail.. */
152 if (reclen > buf->count)
153 return -EINVAL;
David Howellsafefdbb2006-10-03 01:13:46 -0700154 d_ino = ino;
155 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
156 return -EOVERFLOW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 dirent = buf->previous;
158 if (dirent) {
159 if (__put_user(offset, &dirent->d_off))
160 goto efault;
161 }
162 dirent = buf->current_dir;
David Howellsafefdbb2006-10-03 01:13:46 -0700163 if (__put_user(d_ino, &dirent->d_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 goto efault;
165 if (__put_user(reclen, &dirent->d_reclen))
166 goto efault;
167 if (copy_to_user(dirent->d_name, name, namlen))
168 goto efault;
169 if (__put_user(0, dirent->d_name + namlen))
170 goto efault;
171 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
172 goto efault;
173 buf->previous = dirent;
174 dirent = (void __user *)dirent + reclen;
175 buf->current_dir = dirent;
176 buf->count -= reclen;
177 return 0;
178efault:
179 buf->error = -EFAULT;
180 return -EFAULT;
181}
182
183asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
184{
185 struct file * file;
186 struct linux_dirent __user * lastdirent;
187 struct getdents_callback buf;
188 int error;
189
190 error = -EFAULT;
191 if (!access_ok(VERIFY_WRITE, dirent, count))
192 goto out;
193
194 error = -EBADF;
195 file = fget(fd);
196 if (!file)
197 goto out;
198
199 buf.current_dir = dirent;
200 buf.previous = NULL;
201 buf.count = count;
202 buf.error = 0;
203
204 error = vfs_readdir(file, filldir, &buf);
205 if (error < 0)
206 goto out_putf;
207 error = buf.error;
208 lastdirent = buf.previous;
209 if (lastdirent) {
210 if (put_user(file->f_pos, &lastdirent->d_off))
211 error = -EFAULT;
212 else
213 error = count - buf.count;
214 }
215
216out_putf:
217 fput(file);
218out:
219 return error;
220}
221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222struct getdents_callback64 {
223 struct linux_dirent64 __user * current_dir;
224 struct linux_dirent64 __user * previous;
225 int count;
226 int error;
227};
228
229static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
David Howellsafefdbb2006-10-03 01:13:46 -0700230 u64 ino, unsigned int d_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231{
232 struct linux_dirent64 __user *dirent;
233 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
Milind Arun Choudhary022a1692007-05-08 00:29:02 -0700234 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
236 buf->error = -EINVAL; /* only used if we fail.. */
237 if (reclen > buf->count)
238 return -EINVAL;
239 dirent = buf->previous;
240 if (dirent) {
241 if (__put_user(offset, &dirent->d_off))
242 goto efault;
243 }
244 dirent = buf->current_dir;
245 if (__put_user(ino, &dirent->d_ino))
246 goto efault;
247 if (__put_user(0, &dirent->d_off))
248 goto efault;
249 if (__put_user(reclen, &dirent->d_reclen))
250 goto efault;
251 if (__put_user(d_type, &dirent->d_type))
252 goto efault;
253 if (copy_to_user(dirent->d_name, name, namlen))
254 goto efault;
255 if (__put_user(0, dirent->d_name + namlen))
256 goto efault;
257 buf->previous = dirent;
258 dirent = (void __user *)dirent + reclen;
259 buf->current_dir = dirent;
260 buf->count -= reclen;
261 return 0;
262efault:
263 buf->error = -EFAULT;
264 return -EFAULT;
265}
266
267asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
268{
269 struct file * file;
270 struct linux_dirent64 __user * lastdirent;
271 struct getdents_callback64 buf;
272 int error;
273
274 error = -EFAULT;
275 if (!access_ok(VERIFY_WRITE, dirent, count))
276 goto out;
277
278 error = -EBADF;
279 file = fget(fd);
280 if (!file)
281 goto out;
282
283 buf.current_dir = dirent;
284 buf.previous = NULL;
285 buf.count = count;
286 buf.error = 0;
287
288 error = vfs_readdir(file, filldir64, &buf);
289 if (error < 0)
290 goto out_putf;
291 error = buf.error;
292 lastdirent = buf.previous;
293 if (lastdirent) {
294 typeof(lastdirent->d_off) d_off = file->f_pos;
295 error = -EFAULT;
296 if (__put_user(d_off, &lastdirent->d_off))
297 goto out_putf;
298 error = count - buf.count;
299 }
300
301out_putf:
302 fput(file);
303out:
304 return error;
305}