Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/readdir.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | */ | |
6 | ||
022a1692 | 7 | #include <linux/kernel.h> |
1da177e4 LT |
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> | |
1da177e4 LT |
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 | ||
22 | int vfs_readdir(struct file *file, filldir_t filler, void *buf) | |
23 | { | |
0f7fc9e4 | 24 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
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 | ||
da784511 LH |
33 | res = mutex_lock_killable(&inode->i_mutex); |
34 | if (res) | |
35 | goto out; | |
36 | ||
1da177e4 LT |
37 | res = -ENOENT; |
38 | if (!IS_DEADDIR(inode)) { | |
39 | res = file->f_op->readdir(file, buf, filler); | |
40 | file_accessed(file); | |
41 | } | |
1b1dcc1b | 42 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
43 | out: |
44 | return res; | |
45 | } | |
46 | ||
47 | EXPORT_SYMBOL(vfs_readdir); | |
48 | ||
49 | /* | |
50 | * Traditional linux readdir() handling.. | |
51 | * | |
52 | * "count=1" is a special case, meaning that the buffer is one | |
53 | * dirent-structure in size and that the code can't handle more | |
54 | * anyway. Thus the special "fillonedir()" function for that | |
55 | * case (the low-level handlers don't need to care about this). | |
56 | */ | |
57 | #define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de))) | |
1da177e4 LT |
58 | |
59 | #ifdef __ARCH_WANT_OLD_READDIR | |
60 | ||
61 | struct 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 | ||
68 | struct readdir_callback { | |
69 | struct old_linux_dirent __user * dirent; | |
70 | int result; | |
71 | }; | |
72 | ||
73 | static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset, | |
afefdbb2 | 74 | u64 ino, unsigned int d_type) |
1da177e4 LT |
75 | { |
76 | struct readdir_callback * buf = (struct readdir_callback *) __buf; | |
77 | struct old_linux_dirent __user * dirent; | |
afefdbb2 | 78 | unsigned long d_ino; |
1da177e4 LT |
79 | |
80 | if (buf->result) | |
81 | return -EINVAL; | |
afefdbb2 | 82 | d_ino = ino; |
8f3f655d AV |
83 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
84 | buf->result = -EOVERFLOW; | |
afefdbb2 | 85 | return -EOVERFLOW; |
8f3f655d | 86 | } |
1da177e4 LT |
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; | |
afefdbb2 | 93 | if ( __put_user(d_ino, &dirent->d_ino) || |
1da177e4 LT |
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; | |
100 | efault: | |
101 | buf->result = -EFAULT; | |
102 | return -EFAULT; | |
103 | } | |
104 | ||
d4e82042 HC |
105 | SYSCALL_DEFINE3(old_readdir, unsigned int, fd, |
106 | struct old_linux_dirent __user *, dirent, unsigned int, count) | |
1da177e4 LT |
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); | |
53c9c5c0 | 121 | if (buf.result) |
1da177e4 LT |
122 | error = buf.result; |
123 | ||
124 | fput(file); | |
125 | out: | |
126 | return error; | |
127 | } | |
128 | ||
129 | #endif /* __ARCH_WANT_OLD_READDIR */ | |
130 | ||
131 | /* | |
132 | * New, all-improved, singing, dancing, iBCS2-compliant getdents() | |
133 | * interface. | |
134 | */ | |
135 | struct linux_dirent { | |
136 | unsigned long d_ino; | |
137 | unsigned long d_off; | |
138 | unsigned short d_reclen; | |
139 | char d_name[1]; | |
140 | }; | |
141 | ||
142 | struct getdents_callback { | |
143 | struct linux_dirent __user * current_dir; | |
144 | struct linux_dirent __user * previous; | |
145 | int count; | |
146 | int error; | |
147 | }; | |
148 | ||
149 | static int filldir(void * __buf, const char * name, int namlen, loff_t offset, | |
afefdbb2 | 150 | u64 ino, unsigned int d_type) |
1da177e4 LT |
151 | { |
152 | struct linux_dirent __user * dirent; | |
153 | struct getdents_callback * buf = (struct getdents_callback *) __buf; | |
afefdbb2 | 154 | unsigned long d_ino; |
022a1692 | 155 | int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long)); |
1da177e4 LT |
156 | |
157 | buf->error = -EINVAL; /* only used if we fail.. */ | |
158 | if (reclen > buf->count) | |
159 | return -EINVAL; | |
afefdbb2 | 160 | d_ino = ino; |
8f3f655d AV |
161 | if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { |
162 | buf->error = -EOVERFLOW; | |
afefdbb2 | 163 | return -EOVERFLOW; |
8f3f655d | 164 | } |
1da177e4 LT |
165 | dirent = buf->previous; |
166 | if (dirent) { | |
167 | if (__put_user(offset, &dirent->d_off)) | |
168 | goto efault; | |
169 | } | |
170 | dirent = buf->current_dir; | |
afefdbb2 | 171 | if (__put_user(d_ino, &dirent->d_ino)) |
1da177e4 LT |
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; | |
186 | efault: | |
187 | buf->error = -EFAULT; | |
188 | return -EFAULT; | |
189 | } | |
190 | ||
20f37034 HC |
191 | SYSCALL_DEFINE3(getdents, unsigned int, fd, |
192 | struct linux_dirent __user *, dirent, unsigned int, count) | |
1da177e4 LT |
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); | |
53c9c5c0 AV |
214 | if (error >= 0) |
215 | error = buf.error; | |
1da177e4 LT |
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 | } | |
1da177e4 LT |
223 | fput(file); |
224 | out: | |
225 | return error; | |
226 | } | |
227 | ||
1da177e4 LT |
228 | struct getdents_callback64 { |
229 | struct linux_dirent64 __user * current_dir; | |
230 | struct linux_dirent64 __user * previous; | |
231 | int count; | |
232 | int error; | |
233 | }; | |
234 | ||
235 | static int filldir64(void * __buf, const char * name, int namlen, loff_t offset, | |
afefdbb2 | 236 | u64 ino, unsigned int d_type) |
1da177e4 LT |
237 | { |
238 | struct linux_dirent64 __user *dirent; | |
239 | struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf; | |
022a1692 | 240 | int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64)); |
1da177e4 LT |
241 | |
242 | buf->error = -EINVAL; /* only used if we fail.. */ | |
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; | |
268 | efault: | |
269 | buf->error = -EFAULT; | |
270 | return -EFAULT; | |
271 | } | |
272 | ||
20f37034 HC |
273 | SYSCALL_DEFINE3(getdents64, unsigned int, fd, |
274 | struct linux_dirent64 __user *, dirent, unsigned int, count) | |
1da177e4 LT |
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); | |
53c9c5c0 AV |
296 | if (error >= 0) |
297 | error = buf.error; | |
1da177e4 LT |
298 | lastdirent = buf.previous; |
299 | if (lastdirent) { | |
300 | typeof(lastdirent->d_off) d_off = file->f_pos; | |
1da177e4 | 301 | if (__put_user(d_off, &lastdirent->d_off)) |
53c9c5c0 AV |
302 | error = -EFAULT; |
303 | else | |
304 | error = count - buf.count; | |
1da177e4 | 305 | } |
1da177e4 LT |
306 | fput(file); |
307 | out: | |
308 | return error; | |
309 | } |