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7#include <linux/kernel.h>
8#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>
14#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{
24 struct inode *inode = file->f_path.dentry->d_inode;
25 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
33 res = mutex_lock_killable(&inode->i_mutex);
34 if (res)
35 goto out;
36
37 res = -ENOENT;
38 if (!IS_DEADDIR(inode)) {
39 res = file->f_op->readdir(file, buf, filler);
40 file_accessed(file);
41 }
42 mutex_unlock(&inode->i_mutex);
43out:
44 return res;
45}
46
47EXPORT_SYMBOL(vfs_readdir);
48
49
50
51
52
53
54
55
56
57#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
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(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));
156
157 buf->error = -EINVAL;
158 if (reclen > buf->count)
159 return -EINVAL;
160 d_ino = ino;
161 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
162 buf->error = -EOVERFLOW;
163 return -EOVERFLOW;
164 }
165 dirent = buf->previous;
166 if (dirent) {
167 if (__put_user(offset, &dirent->d_off))
168 goto efault;
169 }
170 dirent = buf->current_dir;
171 if (__put_user(d_ino, &dirent->d_ino))
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
191SYSCALL_DEFINE3(getdents, unsigned int, fd,
192 struct linux_dirent __user *, dirent, unsigned int, count)
193{
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);
214 if (error >= 0)
215 error = buf.error;
216 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 }
223 fput(file);
224out:
225 return error;
226}
227
228struct 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,
236 u64 ino, unsigned int d_type)
237{
238 struct linux_dirent64 __user *dirent;
239 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
240 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));
241
242 buf->error = -EINVAL;
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
273SYSCALL_DEFINE3(getdents64, unsigned int, fd,
274 struct linux_dirent64 __user *, dirent, unsigned int, count)
275{
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);
296 if (error >= 0)
297 error = buf.error;
298 lastdirent = buf.previous;
299 if (lastdirent) {
300 typeof(lastdirent->d_off) d_off = file->f_pos;
301 if (__put_user(d_off, &lastdirent->d_off))
302 error = -EFAULT;
303 else
304 error = count - buf.count;
305 }
306 fput(file);
307out:
308 return error;
309}
310
