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7#include <linux/stddef.h>
8#include <linux/kernel.h>
9#include <linux/export.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 iterate_dir(struct file *file, struct dir_context *ctx)
24{
25 struct inode *inode = file_inode(file);
26 int res = -ENOTDIR;
27 if (!file->f_op ||
28 (!file->f_op->readdir && !(file->f_mode & FMODE_KABI_ITERATE)))
29 goto out;
30
31 res = security_file_permission(file, MAY_READ);
32 if (res)
33 goto out;
34
35 res = mutex_lock_killable(&inode->i_mutex);
36 if (res)
37 goto out;
38
39 res = -ENOENT;
40 if (!IS_DEADDIR(inode)) {
41 if (file->f_mode & FMODE_KABI_ITERATE) {
42 ctx->pos = file->f_pos;
43 res = file->f_op->iterate(file, ctx);
44 file->f_pos = ctx->pos;
45 } else {
46 res = file->f_op->readdir(file, ctx, ctx->actor);
47 ctx->pos = file->f_pos;
48 }
49 file_accessed(file);
50 }
51 mutex_unlock(&inode->i_mutex);
52out:
53 return res;
54}
55EXPORT_SYMBOL(iterate_dir);
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64
65
66#ifdef __ARCH_WANT_OLD_READDIR
67
68struct old_linux_dirent {
69 unsigned long d_ino;
70 unsigned long d_offset;
71 unsigned short d_namlen;
72 char d_name[1];
73};
74
75struct readdir_callback {
76 struct dir_context ctx;
77 struct old_linux_dirent __user * dirent;
78 int result;
79};
80
81static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
82 u64 ino, unsigned int d_type)
83{
84 struct readdir_callback *buf = (struct readdir_callback *) __buf;
85 struct old_linux_dirent __user * dirent;
86 unsigned long d_ino;
87
88 if (buf->result)
89 return -EINVAL;
90 d_ino = ino;
91 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
92 buf->result = -EOVERFLOW;
93 return -EOVERFLOW;
94 }
95 buf->result++;
96 dirent = buf->dirent;
97 if (!access_ok(VERIFY_WRITE, dirent,
98 (unsigned long)(dirent->d_name + namlen + 1) -
99 (unsigned long)dirent))
100 goto efault;
101 if ( __put_user(d_ino, &dirent->d_ino) ||
102 __put_user(offset, &dirent->d_offset) ||
103 __put_user(namlen, &dirent->d_namlen) ||
104 __copy_to_user(dirent->d_name, name, namlen) ||
105 __put_user(0, dirent->d_name + namlen))
106 goto efault;
107 return 0;
108efault:
109 buf->result = -EFAULT;
110 return -EFAULT;
111}
112
113SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
114 struct old_linux_dirent __user *, dirent, unsigned int, count)
115{
116 int error;
117 struct fd f = fdget(fd);
118 struct readdir_callback buf;
119
120 if (!f.file)
121 return -EBADF;
122
123 buf.ctx.actor = fillonedir;
124 buf.result = 0;
125 buf.dirent = dirent;
126
127 error = iterate_dir(f.file, &buf.ctx);
128 if (buf.result)
129 error = buf.result;
130
131 fdput(f);
132 return error;
133}
134
135#endif
136
137
138
139
140
141struct linux_dirent {
142 unsigned long d_ino;
143 unsigned long d_off;
144 unsigned short d_reclen;
145 char d_name[1];
146};
147
148struct getdents_callback {
149 struct dir_context ctx;
150 struct linux_dirent __user * current_dir;
151 struct linux_dirent __user * previous;
152 int count;
153 int error;
154};
155
156static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
157 u64 ino, unsigned int d_type)
158{
159 struct linux_dirent __user * dirent;
160 struct getdents_callback * buf = (struct getdents_callback *) __buf;
161 unsigned long d_ino;
162 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
163 sizeof(long));
164
165 buf->error = -EINVAL;
166 if (reclen > buf->count)
167 return -EINVAL;
168 d_ino = ino;
169 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
170 buf->error = -EOVERFLOW;
171 return -EOVERFLOW;
172 }
173 dirent = buf->previous;
174 if (dirent) {
175 if (__put_user(offset, &dirent->d_off))
176 goto efault;
177 }
178 dirent = buf->current_dir;
179 if (__put_user(d_ino, &dirent->d_ino))
180 goto efault;
181 if (__put_user(reclen, &dirent->d_reclen))
182 goto efault;
183 if (copy_to_user(dirent->d_name, name, namlen))
184 goto efault;
185 if (__put_user(0, dirent->d_name + namlen))
186 goto efault;
187 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
188 goto efault;
189 buf->previous = dirent;
190 dirent = (void __user *)dirent + reclen;
191 buf->current_dir = dirent;
192 buf->count -= reclen;
193 return 0;
194efault:
195 buf->error = -EFAULT;
196 return -EFAULT;
197}
198
199SYSCALL_DEFINE3(getdents, unsigned int, fd,
200 struct linux_dirent __user *, dirent, unsigned int, count)
201{
202 struct fd f;
203 struct linux_dirent __user * lastdirent;
204 struct getdents_callback buf;
205 int error;
206
207 if (!access_ok(VERIFY_WRITE, dirent, count))
208 return -EFAULT;
209
210 f = fdget(fd);
211 if (!f.file)
212 return -EBADF;
213
214 buf.current_dir = dirent;
215 buf.previous = NULL;
216 buf.count = count;
217 buf.error = 0;
218 buf.ctx.actor = filldir;
219
220 error = iterate_dir(f.file, &buf.ctx);
221 if (error >= 0)
222 error = buf.error;
223 lastdirent = buf.previous;
224 if (lastdirent) {
225 if (put_user(buf.ctx.pos, &lastdirent->d_off))
226 error = -EFAULT;
227 else
228 error = count - buf.count;
229 }
230 fdput(f);
231 return error;
232}
233
234struct getdents_callback64 {
235 struct dir_context ctx;
236 struct linux_dirent64 __user * current_dir;
237 struct linux_dirent64 __user * previous;
238 int count;
239 int error;
240};
241
242static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
243 u64 ino, unsigned int d_type)
244{
245 struct linux_dirent64 __user *dirent;
246 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
247 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
248 sizeof(u64));
249
250 buf->error = -EINVAL;
251 if (reclen > buf->count)
252 return -EINVAL;
253 dirent = buf->previous;
254 if (dirent) {
255 if (__put_user(offset, &dirent->d_off))
256 goto efault;
257 }
258 dirent = buf->current_dir;
259 if (__put_user(ino, &dirent->d_ino))
260 goto efault;
261 if (__put_user(0, &dirent->d_off))
262 goto efault;
263 if (__put_user(reclen, &dirent->d_reclen))
264 goto efault;
265 if (__put_user(d_type, &dirent->d_type))
266 goto efault;
267 if (copy_to_user(dirent->d_name, name, namlen))
268 goto efault;
269 if (__put_user(0, dirent->d_name + namlen))
270 goto efault;
271 buf->previous = dirent;
272 dirent = (void __user *)dirent + reclen;
273 buf->current_dir = dirent;
274 buf->count -= reclen;
275 return 0;
276efault:
277 buf->error = -EFAULT;
278 return -EFAULT;
279}
280
281SYSCALL_DEFINE3(getdents64, unsigned int, fd,
282 struct linux_dirent64 __user *, dirent, unsigned int, count)
283{
284 struct fd f;
285 struct linux_dirent64 __user * lastdirent;
286 struct getdents_callback64 buf;
287 int error;
288
289 if (!access_ok(VERIFY_WRITE, dirent, count))
290 return -EFAULT;
291
292 f = fdget(fd);
293 if (!f.file)
294 return -EBADF;
295
296 buf.current_dir = dirent;
297 buf.previous = NULL;
298 buf.count = count;
299 buf.error = 0;
300 buf.ctx.actor = filldir64;
301
302 error = iterate_dir(f.file, &buf.ctx);
303 if (error >= 0)
304 error = buf.error;
305 lastdirent = buf.previous;
306 if (lastdirent) {
307 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
308 if (__put_user(d_off, &lastdirent->d_off))
309 error = -EFAULT;
310 else
311 error = count - buf.count;
312 }
313 fdput(f);
314 return error;
315}
316
