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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 mutex_unlock(&inode->i_mutex);
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(void * __buf, const char * name, int namlen, loff_t offset,
78 u64 ino, unsigned int d_type)
79{
80 struct readdir_callback *buf = (struct readdir_callback *) __buf;
81 struct old_linux_dirent __user * dirent;
82 unsigned long d_ino;
83
84 if (buf->result)
85 return -EINVAL;
86 d_ino = ino;
87 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
88 buf->result = -EOVERFLOW;
89 return -EOVERFLOW;
90 }
91 buf->result++;
92 dirent = buf->dirent;
93 if (!access_ok(VERIFY_WRITE, dirent,
94 (unsigned long)(dirent->d_name + namlen + 1) -
95 (unsigned long)dirent))
96 goto efault;
97 if ( __put_user(d_ino, &dirent->d_ino) ||
98 __put_user(offset, &dirent->d_offset) ||
99 __put_user(namlen, &dirent->d_namlen) ||
100 __copy_to_user(dirent->d_name, name, namlen) ||
101 __put_user(0, dirent->d_name + namlen))
102 goto efault;
103 return 0;
104efault:
105 buf->result = -EFAULT;
106 return -EFAULT;
107}
108
109SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
110 struct old_linux_dirent __user *, dirent, unsigned int, count)
111{
112 int error;
113 struct fd f = fdget(fd);
114 struct readdir_callback buf = {
115 .ctx.actor = fillonedir,
116 .dirent = dirent
117 };
118
119 if (!f.file)
120 return -EBADF;
121
122 error = iterate_dir(f.file, &buf.ctx);
123 if (buf.result)
124 error = buf.result;
125
126 fdput(f);
127 return error;
128}
129
130#endif
131
132
133
134
135
136struct linux_dirent {
137 unsigned long d_ino;
138 unsigned long d_off;
139 unsigned short d_reclen;
140 char d_name[1];
141};
142
143struct getdents_callback {
144 struct dir_context ctx;
145 struct linux_dirent __user * current_dir;
146 struct linux_dirent __user * previous;
147 int count;
148 int error;
149};
150
151static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
152 u64 ino, unsigned int d_type)
153{
154 struct linux_dirent __user * dirent;
155 struct getdents_callback * buf = (struct getdents_callback *) __buf;
156 unsigned long d_ino;
157 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
158 sizeof(long));
159
160 buf->error = -EINVAL;
161 if (reclen > buf->count)
162 return -EINVAL;
163 d_ino = ino;
164 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
165 buf->error = -EOVERFLOW;
166 return -EOVERFLOW;
167 }
168 dirent = buf->previous;
169 if (dirent) {
170 if (__put_user(offset, &dirent->d_off))
171 goto efault;
172 }
173 dirent = buf->current_dir;
174 if (__put_user(d_ino, &dirent->d_ino))
175 goto efault;
176 if (__put_user(reclen, &dirent->d_reclen))
177 goto efault;
178 if (copy_to_user(dirent->d_name, name, namlen))
179 goto efault;
180 if (__put_user(0, dirent->d_name + namlen))
181 goto efault;
182 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
183 goto efault;
184 buf->previous = dirent;
185 dirent = (void __user *)dirent + reclen;
186 buf->current_dir = dirent;
187 buf->count -= reclen;
188 return 0;
189efault:
190 buf->error = -EFAULT;
191 return -EFAULT;
192}
193
194SYSCALL_DEFINE3(getdents, unsigned int, fd,
195 struct linux_dirent __user *, dirent, unsigned int, count)
196{
197 struct fd f;
198 struct linux_dirent __user * lastdirent;
199 struct getdents_callback buf = {
200 .ctx.actor = filldir,
201 .count = count,
202 .current_dir = dirent
203 };
204 int error;
205
206 if (!access_ok(VERIFY_WRITE, dirent, count))
207 return -EFAULT;
208
209 f = fdget(fd);
210 if (!f.file)
211 return -EBADF;
212
213 error = iterate_dir(f.file, &buf.ctx);
214 if (error >= 0)
215 error = buf.error;
216 lastdirent = buf.previous;
217 if (lastdirent) {
218 if (put_user(buf.ctx.pos, &lastdirent->d_off))
219 error = -EFAULT;
220 else
221 error = count - buf.count;
222 }
223 fdput(f);
224 return error;
225}
226
227struct getdents_callback64 {
228 struct dir_context ctx;
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(offsetof(struct linux_dirent64, d_name) + namlen + 1,
241 sizeof(u64));
242
243 buf->error = -EINVAL;
244 if (reclen > buf->count)
245 return -EINVAL;
246 dirent = buf->previous;
247 if (dirent) {
248 if (__put_user(offset, &dirent->d_off))
249 goto efault;
250 }
251 dirent = buf->current_dir;
252 if (__put_user(ino, &dirent->d_ino))
253 goto efault;
254 if (__put_user(0, &dirent->d_off))
255 goto efault;
256 if (__put_user(reclen, &dirent->d_reclen))
257 goto efault;
258 if (__put_user(d_type, &dirent->d_type))
259 goto efault;
260 if (copy_to_user(dirent->d_name, name, namlen))
261 goto efault;
262 if (__put_user(0, dirent->d_name + namlen))
263 goto efault;
264 buf->previous = dirent;
265 dirent = (void __user *)dirent + reclen;
266 buf->current_dir = dirent;
267 buf->count -= reclen;
268 return 0;
269efault:
270 buf->error = -EFAULT;
271 return -EFAULT;
272}
273
274SYSCALL_DEFINE3(getdents64, unsigned int, fd,
275 struct linux_dirent64 __user *, dirent, unsigned int, count)
276{
277 struct fd f;
278 struct linux_dirent64 __user * lastdirent;
279 struct getdents_callback64 buf = {
280 .ctx.actor = filldir64,
281 .count = count,
282 .current_dir = dirent
283 };
284 int error;
285
286 if (!access_ok(VERIFY_WRITE, dirent, count))
287 return -EFAULT;
288
289 f = fdget(fd);
290 if (!f.file)
291 return -EBADF;
292
293 error = iterate_dir(f.file, &buf.ctx);
294 if (error >= 0)
295 error = buf.error;
296 lastdirent = buf.previous;
297 if (lastdirent) {
298 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
299 if (__put_user(d_off, &lastdirent->d_off))
300 error = -EFAULT;
301 else
302 error = count - buf.count;
303 }
304 fdput(f);
305 return error;
306}
307
