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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/readdir.c
4 *
5 * Copyright (C) 1995 Linus Torvalds
6 */
7
8#include <linux/stddef.h>
9#include <linux/kernel.h>
10#include <linux/export.h>
11#include <linux/time.h>
12#include <linux/mm.h>
13#include <linux/errno.h>
14#include <linux/stat.h>
15#include <linux/file.h>
16#include <linux/fs.h>
17#include <linux/fsnotify.h>
18#include <linux/dirent.h>
19#include <linux/security.h>
20#include <linux/syscalls.h>
21#include <linux/unistd.h>
22#include <linux/compat.h>
23#include <linux/uaccess.h>
24
25/*
26 * Some filesystems were never converted to '->iterate_shared()'
27 * and their directory iterators want the inode lock held for
28 * writing. This wrapper allows for converting from the shared
29 * semantics to the exclusive inode use.
30 */
31int wrap_directory_iterator(struct file *file,
32 struct dir_context *ctx,
33 int (*iter)(struct file *, struct dir_context *))
34{
35 struct inode *inode = file_inode(file);
36 int ret;
37
38 /*
39 * We'd love to have an 'inode_upgrade_trylock()' operation,
40 * see the comment in mmap_upgrade_trylock() in mm/memory.c.
41 *
42 * But considering this is for "filesystems that never got
43 * converted", it really doesn't matter.
44 *
45 * Also note that since we have to return with the lock held
46 * for reading, we can't use the "killable()" locking here,
47 * since we do need to get the lock even if we're dying.
48 *
49 * We could do the write part killably and then get the read
50 * lock unconditionally if it mattered, but see above on why
51 * this does the very simplistic conversion.
52 */
53 up_read(&inode->i_rwsem);
54 down_write(&inode->i_rwsem);
55
56 /*
57 * Since we dropped the inode lock, we should do the
58 * DEADDIR test again. See 'iterate_dir()' below.
59 *
60 * Note that we don't need to re-do the f_pos games,
61 * since the file must be locked wrt f_pos anyway.
62 */
63 ret = -ENOENT;
64 if (!IS_DEADDIR(inode))
65 ret = iter(file, ctx);
66
67 downgrade_write(&inode->i_rwsem);
68 return ret;
69}
70EXPORT_SYMBOL(wrap_directory_iterator);
71
72/*
73 * Note the "unsafe_put_user()" semantics: we goto a
74 * label for errors.
75 */
76#define unsafe_copy_dirent_name(_dst, _src, _len, label) do { \
77 char __user *dst = (_dst); \
78 const char *src = (_src); \
79 size_t len = (_len); \
80 unsafe_put_user(0, dst+len, label); \
81 unsafe_copy_to_user(dst, src, len, label); \
82} while (0)
83
84
85int iterate_dir(struct file *file, struct dir_context *ctx)
86{
87 struct inode *inode = file_inode(file);
88 int res = -ENOTDIR;
89
90 if (!file->f_op->iterate_shared)
91 goto out;
92
93 res = security_file_permission(file, MAY_READ);
94 if (res)
95 goto out;
96
97 res = fsnotify_file_perm(file, MAY_READ);
98 if (res)
99 goto out;
100
101 res = down_read_killable(&inode->i_rwsem);
102 if (res)
103 goto out;
104
105 res = -ENOENT;
106 if (!IS_DEADDIR(inode)) {
107 ctx->pos = file->f_pos;
108 res = file->f_op->iterate_shared(file, ctx);
109 file->f_pos = ctx->pos;
110 fsnotify_access(file);
111 file_accessed(file);
112 }
113 inode_unlock_shared(inode);
114out:
115 return res;
116}
117EXPORT_SYMBOL(iterate_dir);
118
119/*
120 * POSIX says that a dirent name cannot contain NULL or a '/'.
121 *
122 * It's not 100% clear what we should really do in this case.
123 * The filesystem is clearly corrupted, but returning a hard
124 * error means that you now don't see any of the other names
125 * either, so that isn't a perfect alternative.
126 *
127 * And if you return an error, what error do you use? Several
128 * filesystems seem to have decided on EUCLEAN being the error
129 * code for EFSCORRUPTED, and that may be the error to use. Or
130 * just EIO, which is perhaps more obvious to users.
131 *
132 * In order to see the other file names in the directory, the
133 * caller might want to make this a "soft" error: skip the
134 * entry, and return the error at the end instead.
135 *
136 * Note that this should likely do a "memchr(name, 0, len)"
137 * check too, since that would be filesystem corruption as
138 * well. However, that case can't actually confuse user space,
139 * which has to do a strlen() on the name anyway to find the
140 * filename length, and the above "soft error" worry means
141 * that it's probably better left alone until we have that
142 * issue clarified.
143 *
144 * Note the PATH_MAX check - it's arbitrary but the real
145 * kernel limit on a possible path component, not NAME_MAX,
146 * which is the technical standard limit.
147 */
148static int verify_dirent_name(const char *name, int len)
149{
150 if (len <= 0 || len >= PATH_MAX)
151 return -EIO;
152 if (memchr(name, '/', len))
153 return -EIO;
154 return 0;
155}
156
157/*
158 * Traditional linux readdir() handling..
159 *
160 * "count=1" is a special case, meaning that the buffer is one
161 * dirent-structure in size and that the code can't handle more
162 * anyway. Thus the special "fillonedir()" function for that
163 * case (the low-level handlers don't need to care about this).
164 */
165
166#ifdef __ARCH_WANT_OLD_READDIR
167
168struct old_linux_dirent {
169 unsigned long d_ino;
170 unsigned long d_offset;
171 unsigned short d_namlen;
172 char d_name[];
173};
174
175struct readdir_callback {
176 struct dir_context ctx;
177 struct old_linux_dirent __user * dirent;
178 int result;
179};
180
181static bool fillonedir(struct dir_context *ctx, const char *name, int namlen,
182 loff_t offset, u64 ino, unsigned int d_type)
183{
184 struct readdir_callback *buf =
185 container_of(ctx, struct readdir_callback, ctx);
186 struct old_linux_dirent __user * dirent;
187 unsigned long d_ino;
188
189 if (buf->result)
190 return false;
191 buf->result = verify_dirent_name(name, namlen);
192 if (buf->result)
193 return false;
194 d_ino = ino;
195 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
196 buf->result = -EOVERFLOW;
197 return false;
198 }
199 buf->result++;
200 dirent = buf->dirent;
201 if (!user_write_access_begin(dirent,
202 (unsigned long)(dirent->d_name + namlen + 1) -
203 (unsigned long)dirent))
204 goto efault;
205 unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
206 unsafe_put_user(offset, &dirent->d_offset, efault_end);
207 unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
208 unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
209 user_write_access_end();
210 return true;
211efault_end:
212 user_write_access_end();
213efault:
214 buf->result = -EFAULT;
215 return false;
216}
217
218SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
219 struct old_linux_dirent __user *, dirent, unsigned int, count)
220{
221 int error;
222 CLASS(fd_pos, f)(fd);
223 struct readdir_callback buf = {
224 .ctx.actor = fillonedir,
225 .dirent = dirent
226 };
227
228 if (fd_empty(f))
229 return -EBADF;
230
231 error = iterate_dir(fd_file(f), &buf.ctx);
232 if (buf.result)
233 error = buf.result;
234
235 return error;
236}
237
238#endif /* __ARCH_WANT_OLD_READDIR */
239
240/*
241 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
242 * interface.
243 */
244struct linux_dirent {
245 unsigned long d_ino;
246 unsigned long d_off;
247 unsigned short d_reclen;
248 char d_name[];
249};
250
251struct getdents_callback {
252 struct dir_context ctx;
253 struct linux_dirent __user * current_dir;
254 int prev_reclen;
255 int count;
256 int error;
257};
258
259static bool filldir(struct dir_context *ctx, const char *name, int namlen,
260 loff_t offset, u64 ino, unsigned int d_type)
261{
262 struct linux_dirent __user *dirent, *prev;
263 struct getdents_callback *buf =
264 container_of(ctx, struct getdents_callback, ctx);
265 unsigned long d_ino;
266 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
267 sizeof(long));
268 int prev_reclen;
269
270 buf->error = verify_dirent_name(name, namlen);
271 if (unlikely(buf->error))
272 return false;
273 buf->error = -EINVAL; /* only used if we fail.. */
274 if (reclen > buf->count)
275 return false;
276 d_ino = ino;
277 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
278 buf->error = -EOVERFLOW;
279 return false;
280 }
281 prev_reclen = buf->prev_reclen;
282 if (prev_reclen && signal_pending(current))
283 return false;
284 dirent = buf->current_dir;
285 prev = (void __user *) dirent - prev_reclen;
286 if (!user_write_access_begin(prev, reclen + prev_reclen))
287 goto efault;
288
289 /* This might be 'dirent->d_off', but if so it will get overwritten */
290 unsafe_put_user(offset, &prev->d_off, efault_end);
291 unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
292 unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
293 unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
294 unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
295 user_write_access_end();
296
297 buf->current_dir = (void __user *)dirent + reclen;
298 buf->prev_reclen = reclen;
299 buf->count -= reclen;
300 return true;
301efault_end:
302 user_write_access_end();
303efault:
304 buf->error = -EFAULT;
305 return false;
306}
307
308SYSCALL_DEFINE3(getdents, unsigned int, fd,
309 struct linux_dirent __user *, dirent, unsigned int, count)
310{
311 CLASS(fd_pos, f)(fd);
312 struct getdents_callback buf = {
313 .ctx.actor = filldir,
314 .count = count,
315 .current_dir = dirent
316 };
317 int error;
318
319 if (fd_empty(f))
320 return -EBADF;
321
322 error = iterate_dir(fd_file(f), &buf.ctx);
323 if (error >= 0)
324 error = buf.error;
325 if (buf.prev_reclen) {
326 struct linux_dirent __user * lastdirent;
327 lastdirent = (void __user *)buf.current_dir - buf.prev_reclen;
328
329 if (put_user(buf.ctx.pos, &lastdirent->d_off))
330 error = -EFAULT;
331 else
332 error = count - buf.count;
333 }
334 return error;
335}
336
337struct getdents_callback64 {
338 struct dir_context ctx;
339 struct linux_dirent64 __user * current_dir;
340 int prev_reclen;
341 int count;
342 int error;
343};
344
345static bool filldir64(struct dir_context *ctx, const char *name, int namlen,
346 loff_t offset, u64 ino, unsigned int d_type)
347{
348 struct linux_dirent64 __user *dirent, *prev;
349 struct getdents_callback64 *buf =
350 container_of(ctx, struct getdents_callback64, ctx);
351 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
352 sizeof(u64));
353 int prev_reclen;
354
355 buf->error = verify_dirent_name(name, namlen);
356 if (unlikely(buf->error))
357 return false;
358 buf->error = -EINVAL; /* only used if we fail.. */
359 if (reclen > buf->count)
360 return false;
361 prev_reclen = buf->prev_reclen;
362 if (prev_reclen && signal_pending(current))
363 return false;
364 dirent = buf->current_dir;
365 prev = (void __user *)dirent - prev_reclen;
366 if (!user_write_access_begin(prev, reclen + prev_reclen))
367 goto efault;
368
369 /* This might be 'dirent->d_off', but if so it will get overwritten */
370 unsafe_put_user(offset, &prev->d_off, efault_end);
371 unsafe_put_user(ino, &dirent->d_ino, efault_end);
372 unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
373 unsafe_put_user(d_type, &dirent->d_type, efault_end);
374 unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
375 user_write_access_end();
376
377 buf->prev_reclen = reclen;
378 buf->current_dir = (void __user *)dirent + reclen;
379 buf->count -= reclen;
380 return true;
381
382efault_end:
383 user_write_access_end();
384efault:
385 buf->error = -EFAULT;
386 return false;
387}
388
389SYSCALL_DEFINE3(getdents64, unsigned int, fd,
390 struct linux_dirent64 __user *, dirent, unsigned int, count)
391{
392 CLASS(fd_pos, f)(fd);
393 struct getdents_callback64 buf = {
394 .ctx.actor = filldir64,
395 .count = count,
396 .current_dir = dirent
397 };
398 int error;
399
400 if (fd_empty(f))
401 return -EBADF;
402
403 error = iterate_dir(fd_file(f), &buf.ctx);
404 if (error >= 0)
405 error = buf.error;
406 if (buf.prev_reclen) {
407 struct linux_dirent64 __user * lastdirent;
408 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
409
410 lastdirent = (void __user *) buf.current_dir - buf.prev_reclen;
411 if (put_user(d_off, &lastdirent->d_off))
412 error = -EFAULT;
413 else
414 error = count - buf.count;
415 }
416 return error;
417}
418
419#ifdef CONFIG_COMPAT
420struct compat_old_linux_dirent {
421 compat_ulong_t d_ino;
422 compat_ulong_t d_offset;
423 unsigned short d_namlen;
424 char d_name[];
425};
426
427struct compat_readdir_callback {
428 struct dir_context ctx;
429 struct compat_old_linux_dirent __user *dirent;
430 int result;
431};
432
433static bool compat_fillonedir(struct dir_context *ctx, const char *name,
434 int namlen, loff_t offset, u64 ino,
435 unsigned int d_type)
436{
437 struct compat_readdir_callback *buf =
438 container_of(ctx, struct compat_readdir_callback, ctx);
439 struct compat_old_linux_dirent __user *dirent;
440 compat_ulong_t d_ino;
441
442 if (buf->result)
443 return false;
444 buf->result = verify_dirent_name(name, namlen);
445 if (buf->result)
446 return false;
447 d_ino = ino;
448 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
449 buf->result = -EOVERFLOW;
450 return false;
451 }
452 buf->result++;
453 dirent = buf->dirent;
454 if (!user_write_access_begin(dirent,
455 (unsigned long)(dirent->d_name + namlen + 1) -
456 (unsigned long)dirent))
457 goto efault;
458 unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
459 unsafe_put_user(offset, &dirent->d_offset, efault_end);
460 unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
461 unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
462 user_write_access_end();
463 return true;
464efault_end:
465 user_write_access_end();
466efault:
467 buf->result = -EFAULT;
468 return false;
469}
470
471COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
472 struct compat_old_linux_dirent __user *, dirent, unsigned int, count)
473{
474 int error;
475 CLASS(fd_pos, f)(fd);
476 struct compat_readdir_callback buf = {
477 .ctx.actor = compat_fillonedir,
478 .dirent = dirent
479 };
480
481 if (fd_empty(f))
482 return -EBADF;
483
484 error = iterate_dir(fd_file(f), &buf.ctx);
485 if (buf.result)
486 error = buf.result;
487
488 return error;
489}
490
491struct compat_linux_dirent {
492 compat_ulong_t d_ino;
493 compat_ulong_t d_off;
494 unsigned short d_reclen;
495 char d_name[];
496};
497
498struct compat_getdents_callback {
499 struct dir_context ctx;
500 struct compat_linux_dirent __user *current_dir;
501 int prev_reclen;
502 int count;
503 int error;
504};
505
506static bool compat_filldir(struct dir_context *ctx, const char *name, int namlen,
507 loff_t offset, u64 ino, unsigned int d_type)
508{
509 struct compat_linux_dirent __user *dirent, *prev;
510 struct compat_getdents_callback *buf =
511 container_of(ctx, struct compat_getdents_callback, ctx);
512 compat_ulong_t d_ino;
513 int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
514 namlen + 2, sizeof(compat_long_t));
515 int prev_reclen;
516
517 buf->error = verify_dirent_name(name, namlen);
518 if (unlikely(buf->error))
519 return false;
520 buf->error = -EINVAL; /* only used if we fail.. */
521 if (reclen > buf->count)
522 return false;
523 d_ino = ino;
524 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
525 buf->error = -EOVERFLOW;
526 return false;
527 }
528 prev_reclen = buf->prev_reclen;
529 if (prev_reclen && signal_pending(current))
530 return false;
531 dirent = buf->current_dir;
532 prev = (void __user *) dirent - prev_reclen;
533 if (!user_write_access_begin(prev, reclen + prev_reclen))
534 goto efault;
535
536 unsafe_put_user(offset, &prev->d_off, efault_end);
537 unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
538 unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
539 unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
540 unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
541 user_write_access_end();
542
543 buf->prev_reclen = reclen;
544 buf->current_dir = (void __user *)dirent + reclen;
545 buf->count -= reclen;
546 return true;
547efault_end:
548 user_write_access_end();
549efault:
550 buf->error = -EFAULT;
551 return false;
552}
553
554COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
555 struct compat_linux_dirent __user *, dirent, unsigned int, count)
556{
557 CLASS(fd_pos, f)(fd);
558 struct compat_getdents_callback buf = {
559 .ctx.actor = compat_filldir,
560 .current_dir = dirent,
561 .count = count
562 };
563 int error;
564
565 if (fd_empty(f))
566 return -EBADF;
567
568 error = iterate_dir(fd_file(f), &buf.ctx);
569 if (error >= 0)
570 error = buf.error;
571 if (buf.prev_reclen) {
572 struct compat_linux_dirent __user * lastdirent;
573 lastdirent = (void __user *)buf.current_dir - buf.prev_reclen;
574
575 if (put_user(buf.ctx.pos, &lastdirent->d_off))
576 error = -EFAULT;
577 else
578 error = count - buf.count;
579 }
580 return error;
581}
582#endif
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/readdir.c
4 *
5 * Copyright (C) 1995 Linus Torvalds
6 */
7
8#include <linux/stddef.h>
9#include <linux/kernel.h>
10#include <linux/export.h>
11#include <linux/time.h>
12#include <linux/mm.h>
13#include <linux/errno.h>
14#include <linux/stat.h>
15#include <linux/file.h>
16#include <linux/fs.h>
17#include <linux/fsnotify.h>
18#include <linux/dirent.h>
19#include <linux/security.h>
20#include <linux/syscalls.h>
21#include <linux/unistd.h>
22#include <linux/compat.h>
23
24#include <linux/uaccess.h>
25
26int iterate_dir(struct file *file, struct dir_context *ctx)
27{
28 struct inode *inode = file_inode(file);
29 bool shared = false;
30 int res = -ENOTDIR;
31 if (file->f_op->iterate_shared)
32 shared = true;
33 else if (!file->f_op->iterate)
34 goto out;
35
36 res = security_file_permission(file, MAY_READ);
37 if (res)
38 goto out;
39
40 if (shared)
41 res = down_read_killable(&inode->i_rwsem);
42 else
43 res = down_write_killable(&inode->i_rwsem);
44 if (res)
45 goto out;
46
47 res = -ENOENT;
48 if (!IS_DEADDIR(inode)) {
49 ctx->pos = file->f_pos;
50 if (shared)
51 res = file->f_op->iterate_shared(file, ctx);
52 else
53 res = file->f_op->iterate(file, ctx);
54 file->f_pos = ctx->pos;
55 fsnotify_access(file);
56 file_accessed(file);
57 }
58 if (shared)
59 inode_unlock_shared(inode);
60 else
61 inode_unlock(inode);
62out:
63 return res;
64}
65EXPORT_SYMBOL(iterate_dir);
66
67/*
68 * Traditional linux readdir() handling..
69 *
70 * "count=1" is a special case, meaning that the buffer is one
71 * dirent-structure in size and that the code can't handle more
72 * anyway. Thus the special "fillonedir()" function for that
73 * case (the low-level handlers don't need to care about this).
74 */
75
76#ifdef __ARCH_WANT_OLD_READDIR
77
78struct old_linux_dirent {
79 unsigned long d_ino;
80 unsigned long d_offset;
81 unsigned short d_namlen;
82 char d_name[1];
83};
84
85struct readdir_callback {
86 struct dir_context ctx;
87 struct old_linux_dirent __user * dirent;
88 int result;
89};
90
91static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
92 loff_t offset, u64 ino, unsigned int d_type)
93{
94 struct readdir_callback *buf =
95 container_of(ctx, struct readdir_callback, ctx);
96 struct old_linux_dirent __user * dirent;
97 unsigned long d_ino;
98
99 if (buf->result)
100 return -EINVAL;
101 d_ino = ino;
102 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
103 buf->result = -EOVERFLOW;
104 return -EOVERFLOW;
105 }
106 buf->result++;
107 dirent = buf->dirent;
108 if (!access_ok(VERIFY_WRITE, dirent,
109 (unsigned long)(dirent->d_name + namlen + 1) -
110 (unsigned long)dirent))
111 goto efault;
112 if ( __put_user(d_ino, &dirent->d_ino) ||
113 __put_user(offset, &dirent->d_offset) ||
114 __put_user(namlen, &dirent->d_namlen) ||
115 __copy_to_user(dirent->d_name, name, namlen) ||
116 __put_user(0, dirent->d_name + namlen))
117 goto efault;
118 return 0;
119efault:
120 buf->result = -EFAULT;
121 return -EFAULT;
122}
123
124SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
125 struct old_linux_dirent __user *, dirent, unsigned int, count)
126{
127 int error;
128 struct fd f = fdget_pos(fd);
129 struct readdir_callback buf = {
130 .ctx.actor = fillonedir,
131 .dirent = dirent
132 };
133
134 if (!f.file)
135 return -EBADF;
136
137 error = iterate_dir(f.file, &buf.ctx);
138 if (buf.result)
139 error = buf.result;
140
141 fdput_pos(f);
142 return error;
143}
144
145#endif /* __ARCH_WANT_OLD_READDIR */
146
147/*
148 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
149 * interface.
150 */
151struct linux_dirent {
152 unsigned long d_ino;
153 unsigned long d_off;
154 unsigned short d_reclen;
155 char d_name[1];
156};
157
158struct getdents_callback {
159 struct dir_context ctx;
160 struct linux_dirent __user * current_dir;
161 struct linux_dirent __user * previous;
162 int count;
163 int error;
164};
165
166static int filldir(struct dir_context *ctx, const char *name, int namlen,
167 loff_t offset, u64 ino, unsigned int d_type)
168{
169 struct linux_dirent __user * dirent;
170 struct getdents_callback *buf =
171 container_of(ctx, struct getdents_callback, ctx);
172 unsigned long d_ino;
173 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
174 sizeof(long));
175
176 buf->error = -EINVAL; /* only used if we fail.. */
177 if (reclen > buf->count)
178 return -EINVAL;
179 d_ino = ino;
180 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
181 buf->error = -EOVERFLOW;
182 return -EOVERFLOW;
183 }
184 dirent = buf->previous;
185 if (dirent) {
186 if (signal_pending(current))
187 return -EINTR;
188 if (__put_user(offset, &dirent->d_off))
189 goto efault;
190 }
191 dirent = buf->current_dir;
192 if (__put_user(d_ino, &dirent->d_ino))
193 goto efault;
194 if (__put_user(reclen, &dirent->d_reclen))
195 goto efault;
196 if (copy_to_user(dirent->d_name, name, namlen))
197 goto efault;
198 if (__put_user(0, dirent->d_name + namlen))
199 goto efault;
200 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
201 goto efault;
202 buf->previous = dirent;
203 dirent = (void __user *)dirent + reclen;
204 buf->current_dir = dirent;
205 buf->count -= reclen;
206 return 0;
207efault:
208 buf->error = -EFAULT;
209 return -EFAULT;
210}
211
212SYSCALL_DEFINE3(getdents, unsigned int, fd,
213 struct linux_dirent __user *, dirent, unsigned int, count)
214{
215 struct fd f;
216 struct linux_dirent __user * lastdirent;
217 struct getdents_callback buf = {
218 .ctx.actor = filldir,
219 .count = count,
220 .current_dir = dirent
221 };
222 int error;
223
224 if (!access_ok(VERIFY_WRITE, dirent, count))
225 return -EFAULT;
226
227 f = fdget_pos(fd);
228 if (!f.file)
229 return -EBADF;
230
231 error = iterate_dir(f.file, &buf.ctx);
232 if (error >= 0)
233 error = buf.error;
234 lastdirent = buf.previous;
235 if (lastdirent) {
236 if (put_user(buf.ctx.pos, &lastdirent->d_off))
237 error = -EFAULT;
238 else
239 error = count - buf.count;
240 }
241 fdput_pos(f);
242 return error;
243}
244
245struct getdents_callback64 {
246 struct dir_context ctx;
247 struct linux_dirent64 __user * current_dir;
248 struct linux_dirent64 __user * previous;
249 int count;
250 int error;
251};
252
253static int filldir64(struct dir_context *ctx, const char *name, int namlen,
254 loff_t offset, u64 ino, unsigned int d_type)
255{
256 struct linux_dirent64 __user *dirent;
257 struct getdents_callback64 *buf =
258 container_of(ctx, struct getdents_callback64, ctx);
259 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
260 sizeof(u64));
261
262 buf->error = -EINVAL; /* only used if we fail.. */
263 if (reclen > buf->count)
264 return -EINVAL;
265 dirent = buf->previous;
266 if (dirent) {
267 if (signal_pending(current))
268 return -EINTR;
269 if (__put_user(offset, &dirent->d_off))
270 goto efault;
271 }
272 dirent = buf->current_dir;
273 if (__put_user(ino, &dirent->d_ino))
274 goto efault;
275 if (__put_user(0, &dirent->d_off))
276 goto efault;
277 if (__put_user(reclen, &dirent->d_reclen))
278 goto efault;
279 if (__put_user(d_type, &dirent->d_type))
280 goto efault;
281 if (copy_to_user(dirent->d_name, name, namlen))
282 goto efault;
283 if (__put_user(0, dirent->d_name + namlen))
284 goto efault;
285 buf->previous = dirent;
286 dirent = (void __user *)dirent + reclen;
287 buf->current_dir = dirent;
288 buf->count -= reclen;
289 return 0;
290efault:
291 buf->error = -EFAULT;
292 return -EFAULT;
293}
294
295int ksys_getdents64(unsigned int fd, struct linux_dirent64 __user *dirent,
296 unsigned int count)
297{
298 struct fd f;
299 struct linux_dirent64 __user * lastdirent;
300 struct getdents_callback64 buf = {
301 .ctx.actor = filldir64,
302 .count = count,
303 .current_dir = dirent
304 };
305 int error;
306
307 if (!access_ok(VERIFY_WRITE, dirent, count))
308 return -EFAULT;
309
310 f = fdget_pos(fd);
311 if (!f.file)
312 return -EBADF;
313
314 error = iterate_dir(f.file, &buf.ctx);
315 if (error >= 0)
316 error = buf.error;
317 lastdirent = buf.previous;
318 if (lastdirent) {
319 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
320 if (__put_user(d_off, &lastdirent->d_off))
321 error = -EFAULT;
322 else
323 error = count - buf.count;
324 }
325 fdput_pos(f);
326 return error;
327}
328
329
330SYSCALL_DEFINE3(getdents64, unsigned int, fd,
331 struct linux_dirent64 __user *, dirent, unsigned int, count)
332{
333 return ksys_getdents64(fd, dirent, count);
334}
335
336#ifdef CONFIG_COMPAT
337struct compat_old_linux_dirent {
338 compat_ulong_t d_ino;
339 compat_ulong_t d_offset;
340 unsigned short d_namlen;
341 char d_name[1];
342};
343
344struct compat_readdir_callback {
345 struct dir_context ctx;
346 struct compat_old_linux_dirent __user *dirent;
347 int result;
348};
349
350static int compat_fillonedir(struct dir_context *ctx, const char *name,
351 int namlen, loff_t offset, u64 ino,
352 unsigned int d_type)
353{
354 struct compat_readdir_callback *buf =
355 container_of(ctx, struct compat_readdir_callback, ctx);
356 struct compat_old_linux_dirent __user *dirent;
357 compat_ulong_t d_ino;
358
359 if (buf->result)
360 return -EINVAL;
361 d_ino = ino;
362 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
363 buf->result = -EOVERFLOW;
364 return -EOVERFLOW;
365 }
366 buf->result++;
367 dirent = buf->dirent;
368 if (!access_ok(VERIFY_WRITE, dirent,
369 (unsigned long)(dirent->d_name + namlen + 1) -
370 (unsigned long)dirent))
371 goto efault;
372 if ( __put_user(d_ino, &dirent->d_ino) ||
373 __put_user(offset, &dirent->d_offset) ||
374 __put_user(namlen, &dirent->d_namlen) ||
375 __copy_to_user(dirent->d_name, name, namlen) ||
376 __put_user(0, dirent->d_name + namlen))
377 goto efault;
378 return 0;
379efault:
380 buf->result = -EFAULT;
381 return -EFAULT;
382}
383
384COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
385 struct compat_old_linux_dirent __user *, dirent, unsigned int, count)
386{
387 int error;
388 struct fd f = fdget_pos(fd);
389 struct compat_readdir_callback buf = {
390 .ctx.actor = compat_fillonedir,
391 .dirent = dirent
392 };
393
394 if (!f.file)
395 return -EBADF;
396
397 error = iterate_dir(f.file, &buf.ctx);
398 if (buf.result)
399 error = buf.result;
400
401 fdput_pos(f);
402 return error;
403}
404
405struct compat_linux_dirent {
406 compat_ulong_t d_ino;
407 compat_ulong_t d_off;
408 unsigned short d_reclen;
409 char d_name[1];
410};
411
412struct compat_getdents_callback {
413 struct dir_context ctx;
414 struct compat_linux_dirent __user *current_dir;
415 struct compat_linux_dirent __user *previous;
416 int count;
417 int error;
418};
419
420static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,
421 loff_t offset, u64 ino, unsigned int d_type)
422{
423 struct compat_linux_dirent __user * dirent;
424 struct compat_getdents_callback *buf =
425 container_of(ctx, struct compat_getdents_callback, ctx);
426 compat_ulong_t d_ino;
427 int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
428 namlen + 2, sizeof(compat_long_t));
429
430 buf->error = -EINVAL; /* only used if we fail.. */
431 if (reclen > buf->count)
432 return -EINVAL;
433 d_ino = ino;
434 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
435 buf->error = -EOVERFLOW;
436 return -EOVERFLOW;
437 }
438 dirent = buf->previous;
439 if (dirent) {
440 if (signal_pending(current))
441 return -EINTR;
442 if (__put_user(offset, &dirent->d_off))
443 goto efault;
444 }
445 dirent = buf->current_dir;
446 if (__put_user(d_ino, &dirent->d_ino))
447 goto efault;
448 if (__put_user(reclen, &dirent->d_reclen))
449 goto efault;
450 if (copy_to_user(dirent->d_name, name, namlen))
451 goto efault;
452 if (__put_user(0, dirent->d_name + namlen))
453 goto efault;
454 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
455 goto efault;
456 buf->previous = dirent;
457 dirent = (void __user *)dirent + reclen;
458 buf->current_dir = dirent;
459 buf->count -= reclen;
460 return 0;
461efault:
462 buf->error = -EFAULT;
463 return -EFAULT;
464}
465
466COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
467 struct compat_linux_dirent __user *, dirent, unsigned int, count)
468{
469 struct fd f;
470 struct compat_linux_dirent __user * lastdirent;
471 struct compat_getdents_callback buf = {
472 .ctx.actor = compat_filldir,
473 .current_dir = dirent,
474 .count = count
475 };
476 int error;
477
478 if (!access_ok(VERIFY_WRITE, dirent, count))
479 return -EFAULT;
480
481 f = fdget_pos(fd);
482 if (!f.file)
483 return -EBADF;
484
485 error = iterate_dir(f.file, &buf.ctx);
486 if (error >= 0)
487 error = buf.error;
488 lastdirent = buf.previous;
489 if (lastdirent) {
490 if (put_user(buf.ctx.pos, &lastdirent->d_off))
491 error = -EFAULT;
492 else
493 error = count - buf.count;
494 }
495 fdput_pos(f);
496 return error;
497}
498#endif