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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/fsnotify.h>
17#include <linux/dirent.h>
18#include <linux/security.h>
19#include <linux/syscalls.h>
20#include <linux/unistd.h>
21
22#include <asm/uaccess.h>
23
24int iterate_dir(struct file *file, struct dir_context *ctx)
25{
26 struct inode *inode = file_inode(file);
27 int res = -ENOTDIR;
28 if (!file->f_op->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 ctx->pos = file->f_pos;
42 res = file->f_op->iterate(file, ctx);
43 file->f_pos = ctx->pos;
44 fsnotify_access(file);
45 file_accessed(file);
46 }
47 inode_unlock(inode);
48out:
49 return res;
50}
51EXPORT_SYMBOL(iterate_dir);
52
53
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60
61
62#ifdef __ARCH_WANT_OLD_READDIR
63
64struct old_linux_dirent {
65 unsigned long d_ino;
66 unsigned long d_offset;
67 unsigned short d_namlen;
68 char d_name[1];
69};
70
71struct readdir_callback {
72 struct dir_context ctx;
73 struct old_linux_dirent __user * dirent;
74 int result;
75};
76
77static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
78 loff_t offset, u64 ino, unsigned int d_type)
79{
80 struct readdir_callback *buf =
81 container_of(ctx, struct readdir_callback, ctx);
82 struct old_linux_dirent __user * dirent;
83 unsigned long d_ino;
84
85 if (buf->result)
86 return -EINVAL;
87 d_ino = ino;
88 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
89 buf->result = -EOVERFLOW;
90 return -EOVERFLOW;
91 }
92 buf->result++;
93 dirent = buf->dirent;
94 if (!access_ok(VERIFY_WRITE, dirent,
95 (unsigned long)(dirent->d_name + namlen + 1) -
96 (unsigned long)dirent))
97 goto efault;
98 if ( __put_user(d_ino, &dirent->d_ino) ||
99 __put_user(offset, &dirent->d_offset) ||
100 __put_user(namlen, &dirent->d_namlen) ||
101 __copy_to_user(dirent->d_name, name, namlen) ||
102 __put_user(0, dirent->d_name + namlen))
103 goto efault;
104 return 0;
105efault:
106 buf->result = -EFAULT;
107 return -EFAULT;
108}
109
110SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
111 struct old_linux_dirent __user *, dirent, unsigned int, count)
112{
113 int error;
114 struct fd f = fdget(fd);
115 struct readdir_callback buf = {
116 .ctx.actor = fillonedir,
117 .dirent = dirent
118 };
119
120 if (!f.file)
121 return -EBADF;
122
123 error = iterate_dir(f.file, &buf.ctx);
124 if (buf.result)
125 error = buf.result;
126
127 fdput(f);
128 return error;
129}
130
131#endif
132
133
134
135
136
137struct linux_dirent {
138 unsigned long d_ino;
139 unsigned long d_off;
140 unsigned short d_reclen;
141 char d_name[1];
142};
143
144struct getdents_callback {
145 struct dir_context ctx;
146 struct linux_dirent __user * current_dir;
147 struct linux_dirent __user * previous;
148 int count;
149 int error;
150};
151
152static int filldir(struct dir_context *ctx, const char *name, int namlen,
153 loff_t offset, u64 ino, unsigned int d_type)
154{
155 struct linux_dirent __user * dirent;
156 struct getdents_callback *buf =
157 container_of(ctx, struct getdents_callback, ctx);
158 unsigned long d_ino;
159 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
160 sizeof(long));
161
162 buf->error = -EINVAL;
163 if (reclen > buf->count)
164 return -EINVAL;
165 d_ino = ino;
166 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
167 buf->error = -EOVERFLOW;
168 return -EOVERFLOW;
169 }
170 dirent = buf->previous;
171 if (dirent) {
172 if (__put_user(offset, &dirent->d_off))
173 goto efault;
174 }
175 dirent = buf->current_dir;
176 if (__put_user(d_ino, &dirent->d_ino))
177 goto efault;
178 if (__put_user(reclen, &dirent->d_reclen))
179 goto efault;
180 if (copy_to_user(dirent->d_name, name, namlen))
181 goto efault;
182 if (__put_user(0, dirent->d_name + namlen))
183 goto efault;
184 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
185 goto efault;
186 buf->previous = dirent;
187 dirent = (void __user *)dirent + reclen;
188 buf->current_dir = dirent;
189 buf->count -= reclen;
190 return 0;
191efault:
192 buf->error = -EFAULT;
193 return -EFAULT;
194}
195
196SYSCALL_DEFINE3(getdents, unsigned int, fd,
197 struct linux_dirent __user *, dirent, unsigned int, count)
198{
199 struct fd f;
200 struct linux_dirent __user * lastdirent;
201 struct getdents_callback buf = {
202 .ctx.actor = filldir,
203 .count = count,
204 .current_dir = dirent
205 };
206 int error;
207
208 if (!access_ok(VERIFY_WRITE, dirent, count))
209 return -EFAULT;
210
211 f = fdget(fd);
212 if (!f.file)
213 return -EBADF;
214
215 error = iterate_dir(f.file, &buf.ctx);
216 if (error >= 0)
217 error = buf.error;
218 lastdirent = buf.previous;
219 if (lastdirent) {
220 if (put_user(buf.ctx.pos, &lastdirent->d_off))
221 error = -EFAULT;
222 else
223 error = count - buf.count;
224 }
225 fdput(f);
226 return error;
227}
228
229struct getdents_callback64 {
230 struct dir_context ctx;
231 struct linux_dirent64 __user * current_dir;
232 struct linux_dirent64 __user * previous;
233 int count;
234 int error;
235};
236
237static int filldir64(struct dir_context *ctx, const char *name, int namlen,
238 loff_t offset, u64 ino, unsigned int d_type)
239{
240 struct linux_dirent64 __user *dirent;
241 struct getdents_callback64 *buf =
242 container_of(ctx, struct getdents_callback64, ctx);
243 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
244 sizeof(u64));
245
246 buf->error = -EINVAL;
247 if (reclen > buf->count)
248 return -EINVAL;
249 dirent = buf->previous;
250 if (dirent) {
251 if (__put_user(offset, &dirent->d_off))
252 goto efault;
253 }
254 dirent = buf->current_dir;
255 if (__put_user(ino, &dirent->d_ino))
256 goto efault;
257 if (__put_user(0, &dirent->d_off))
258 goto efault;
259 if (__put_user(reclen, &dirent->d_reclen))
260 goto efault;
261 if (__put_user(d_type, &dirent->d_type))
262 goto efault;
263 if (copy_to_user(dirent->d_name, name, namlen))
264 goto efault;
265 if (__put_user(0, dirent->d_name + namlen))
266 goto efault;
267 buf->previous = dirent;
268 dirent = (void __user *)dirent + reclen;
269 buf->current_dir = dirent;
270 buf->count -= reclen;
271 return 0;
272efault:
273 buf->error = -EFAULT;
274 return -EFAULT;
275}
276
277SYSCALL_DEFINE3(getdents64, unsigned int, fd,
278 struct linux_dirent64 __user *, dirent, unsigned int, count)
279{
280 struct fd f;
281 struct linux_dirent64 __user * lastdirent;
282 struct getdents_callback64 buf = {
283 .ctx.actor = filldir64,
284 .count = count,
285 .current_dir = dirent
286 };
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 error = iterate_dir(f.file, &buf.ctx);
297 if (error >= 0)
298 error = buf.error;
299 lastdirent = buf.previous;
300 if (lastdirent) {
301 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
302 if (__put_user(d_off, &lastdirent->d_off))
303 error = -EFAULT;
304 else
305 error = count - buf.count;
306 }
307 fdput(f);
308 return error;
309}
310
