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6
7#include <linux/stddef.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
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>
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{
25 struct inode *inode = file->f_path.dentry->d_inode;
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
34 res = mutex_lock_killable(&inode->i_mutex);
35 if (res)
36 goto out;
37
38 res = -ENOENT;
39 if (!IS_DEADDIR(inode)) {
40 res = file->f_op->readdir(file, buf, filler);
41 file_accessed(file);
42 }
43 mutex_unlock(&inode->i_mutex);
44out:
45 return res;
46}
47
48EXPORT_SYMBOL(vfs_readdir);
49
50
51
52
53
54
55
56
57
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,
74 u64 ino, unsigned int d_type)
75{
76 struct readdir_callback * buf = (struct readdir_callback *) __buf;
77 struct old_linux_dirent __user * dirent;
78 unsigned long d_ino;
79
80 if (buf->result)
81 return -EINVAL;
82 d_ino = ino;
83 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
84 buf->result = -EOVERFLOW;
85 return -EOVERFLOW;
86 }
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;
93 if ( __put_user(d_ino, &dirent->d_ino) ||
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
105SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
106 struct old_linux_dirent __user *, dirent, unsigned int, count)
107{
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);
121 if (buf.result)
122 error = buf.result;
123
124 fput(file);
125out:
126 return error;
127}
128
129#endif
130
131
132
133
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,
150 u64 ino, unsigned int d_type)
151{
152 struct linux_dirent __user * dirent;
153 struct getdents_callback * buf = (struct getdents_callback *) __buf;
154 unsigned long d_ino;
155 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
156 sizeof(long));
157
158 buf->error = -EINVAL;
159 if (reclen > buf->count)
160 return -EINVAL;
161 d_ino = ino;
162 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
163 buf->error = -EOVERFLOW;
164 return -EOVERFLOW;
165 }
166 dirent = buf->previous;
167 if (dirent) {
168 if (__put_user(offset, &dirent->d_off))
169 goto efault;
170 }
171 dirent = buf->current_dir;
172 if (__put_user(d_ino, &dirent->d_ino))
173 goto efault;
174 if (__put_user(reclen, &dirent->d_reclen))
175 goto efault;
176 if (copy_to_user(dirent->d_name, name, namlen))
177 goto efault;
178 if (__put_user(0, dirent->d_name + namlen))
179 goto efault;
180 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
181 goto efault;
182 buf->previous = dirent;
183 dirent = (void __user *)dirent + reclen;
184 buf->current_dir = dirent;
185 buf->count -= reclen;
186 return 0;
187efault:
188 buf->error = -EFAULT;
189 return -EFAULT;
190}
191
192SYSCALL_DEFINE3(getdents, unsigned int, fd,
193 struct linux_dirent __user *, dirent, unsigned int, count)
194{
195 struct file * file;
196 struct linux_dirent __user * lastdirent;
197 struct getdents_callback buf;
198 int error;
199
200 error = -EFAULT;
201 if (!access_ok(VERIFY_WRITE, dirent, count))
202 goto out;
203
204 error = -EBADF;
205 file = fget(fd);
206 if (!file)
207 goto out;
208
209 buf.current_dir = dirent;
210 buf.previous = NULL;
211 buf.count = count;
212 buf.error = 0;
213
214 error = vfs_readdir(file, filldir, &buf);
215 if (error >= 0)
216 error = buf.error;
217 lastdirent = buf.previous;
218 if (lastdirent) {
219 if (put_user(file->f_pos, &lastdirent->d_off))
220 error = -EFAULT;
221 else
222 error = count - buf.count;
223 }
224 fput(file);
225out:
226 return error;
227}
228
229struct getdents_callback64 {
230 struct linux_dirent64 __user * current_dir;
231 struct linux_dirent64 __user * previous;
232 int count;
233 int error;
234};
235
236static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
237 u64 ino, unsigned int d_type)
238{
239 struct linux_dirent64 __user *dirent;
240 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
241 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
242 sizeof(u64));
243
244 buf->error = -EINVAL;
245 if (reclen > buf->count)
246 return -EINVAL;
247 dirent = buf->previous;
248 if (dirent) {
249 if (__put_user(offset, &dirent->d_off))
250 goto efault;
251 }
252 dirent = buf->current_dir;
253 if (__put_user(ino, &dirent->d_ino))
254 goto efault;
255 if (__put_user(0, &dirent->d_off))
256 goto efault;
257 if (__put_user(reclen, &dirent->d_reclen))
258 goto efault;
259 if (__put_user(d_type, &dirent->d_type))
260 goto efault;
261 if (copy_to_user(dirent->d_name, name, namlen))
262 goto efault;
263 if (__put_user(0, dirent->d_name + namlen))
264 goto efault;
265 buf->previous = dirent;
266 dirent = (void __user *)dirent + reclen;
267 buf->current_dir = dirent;
268 buf->count -= reclen;
269 return 0;
270efault:
271 buf->error = -EFAULT;
272 return -EFAULT;
273}
274
275SYSCALL_DEFINE3(getdents64, unsigned int, fd,
276 struct linux_dirent64 __user *, dirent, unsigned int, count)
277{
278 struct file * file;
279 struct linux_dirent64 __user * lastdirent;
280 struct getdents_callback64 buf;
281 int error;
282
283 error = -EFAULT;
284 if (!access_ok(VERIFY_WRITE, dirent, count))
285 goto out;
286
287 error = -EBADF;
288 file = fget(fd);
289 if (!file)
290 goto out;
291
292 buf.current_dir = dirent;
293 buf.previous = NULL;
294 buf.count = count;
295 buf.error = 0;
296
297 error = vfs_readdir(file, filldir64, &buf);
298 if (error >= 0)
299 error = buf.error;
300 lastdirent = buf.previous;
301 if (lastdirent) {
302 typeof(lastdirent->d_off) d_off = file->f_pos;
303 if (__put_user(d_off, &lastdirent->d_off))
304 error = -EFAULT;
305 else
306 error = count - buf.count;
307 }
308 fput(file);
309out:
310 return error;
311}
312
