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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 return -EOVERFLOW;
85 buf->result++;
86 dirent = buf->dirent;
87 if (!access_ok(VERIFY_WRITE, dirent,
88 (unsigned long)(dirent->d_name + namlen + 1) -
89 (unsigned long)dirent))
90 goto efault;
91 if ( __put_user(d_ino, &dirent->d_ino) ||
92 __put_user(offset, &dirent->d_offset) ||
93 __put_user(namlen, &dirent->d_namlen) ||
94 __copy_to_user(dirent->d_name, name, namlen) ||
95 __put_user(0, dirent->d_name + namlen))
96 goto efault;
97 return 0;
98efault:
99 buf->result = -EFAULT;
100 return -EFAULT;
101}
102
103asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
104{
105 int error;
106 struct file * file;
107 struct readdir_callback buf;
108
109 error = -EBADF;
110 file = fget(fd);
111 if (!file)
112 goto out;
113
114 buf.result = 0;
115 buf.dirent = dirent;
116
117 error = vfs_readdir(file, fillonedir, &buf);
118 if (error >= 0)
119 error = buf.result;
120
121 fput(file);
122out:
123 return error;
124}
125
126#endif
127
128
129
130
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,
147 u64 ino, unsigned int d_type)
148{
149 struct linux_dirent __user * dirent;
150 struct getdents_callback * buf = (struct getdents_callback *) __buf;
151 unsigned long d_ino;
152 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));
153
154 buf->error = -EINVAL;
155 if (reclen > buf->count)
156 return -EINVAL;
157 d_ino = ino;
158 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
159 return -EOVERFLOW;
160 dirent = buf->previous;
161 if (dirent) {
162 if (__put_user(offset, &dirent->d_off))
163 goto efault;
164 }
165 dirent = buf->current_dir;
166 if (__put_user(d_ino, &dirent->d_ino))
167 goto efault;
168 if (__put_user(reclen, &dirent->d_reclen))
169 goto efault;
170 if (copy_to_user(dirent->d_name, name, namlen))
171 goto efault;
172 if (__put_user(0, dirent->d_name + namlen))
173 goto efault;
174 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
175 goto efault;
176 buf->previous = dirent;
177 dirent = (void __user *)dirent + reclen;
178 buf->current_dir = dirent;
179 buf->count -= reclen;
180 return 0;
181efault:
182 buf->error = -EFAULT;
183 return -EFAULT;
184}
185
186asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
187{
188 struct file * file;
189 struct linux_dirent __user * lastdirent;
190 struct getdents_callback buf;
191 int error;
192
193 error = -EFAULT;
194 if (!access_ok(VERIFY_WRITE, dirent, count))
195 goto out;
196
197 error = -EBADF;
198 file = fget(fd);
199 if (!file)
200 goto out;
201
202 buf.current_dir = dirent;
203 buf.previous = NULL;
204 buf.count = count;
205 buf.error = 0;
206
207 error = vfs_readdir(file, filldir, &buf);
208 if (error < 0)
209 goto out_putf;
210 error = buf.error;
211 lastdirent = buf.previous;
212 if (lastdirent) {
213 if (put_user(file->f_pos, &lastdirent->d_off))
214 error = -EFAULT;
215 else
216 error = count - buf.count;
217 }
218
219out_putf:
220 fput(file);
221out:
222 return error;
223}
224
225struct getdents_callback64 {
226 struct linux_dirent64 __user * current_dir;
227 struct linux_dirent64 __user * previous;
228 int count;
229 int error;
230};
231
232static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
233 u64 ino, unsigned int d_type)
234{
235 struct linux_dirent64 __user *dirent;
236 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
237 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));
238
239 buf->error = -EINVAL;
240 if (reclen > buf->count)
241 return -EINVAL;
242 dirent = buf->previous;
243 if (dirent) {
244 if (__put_user(offset, &dirent->d_off))
245 goto efault;
246 }
247 dirent = buf->current_dir;
248 if (__put_user(ino, &dirent->d_ino))
249 goto efault;
250 if (__put_user(0, &dirent->d_off))
251 goto efault;
252 if (__put_user(reclen, &dirent->d_reclen))
253 goto efault;
254 if (__put_user(d_type, &dirent->d_type))
255 goto efault;
256 if (copy_to_user(dirent->d_name, name, namlen))
257 goto efault;
258 if (__put_user(0, dirent->d_name + namlen))
259 goto efault;
260 buf->previous = dirent;
261 dirent = (void __user *)dirent + reclen;
262 buf->current_dir = dirent;
263 buf->count -= reclen;
264 return 0;
265efault:
266 buf->error = -EFAULT;
267 return -EFAULT;
268}
269
270asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
271{
272 struct file * file;
273 struct linux_dirent64 __user * lastdirent;
274 struct getdents_callback64 buf;
275 int error;
276
277 error = -EFAULT;
278 if (!access_ok(VERIFY_WRITE, dirent, count))
279 goto out;
280
281 error = -EBADF;
282 file = fget(fd);
283 if (!file)
284 goto out;
285
286 buf.current_dir = dirent;
287 buf.previous = NULL;
288 buf.count = count;
289 buf.error = 0;
290
291 error = vfs_readdir(file, filldir64, &buf);
292 if (error < 0)
293 goto out_putf;
294 error = buf.error;
295 lastdirent = buf.previous;
296 if (lastdirent) {
297 typeof(lastdirent->d_off) d_off = file->f_pos;
298 error = -EFAULT;
299 if (__put_user(d_off, &lastdirent->d_off))
300 goto out_putf;
301 error = count - buf.count;
302 }
303
304out_putf:
305 fput(file);
306out:
307 return error;
308}
309
