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26#include <linux/file.h>
27#include <linux/vmalloc.h>
28#include <linux/pagemap.h>
29#include <linux/dcache.h>
30#include <linux/namei.h>
31#include <linux/mount.h>
32#include <linux/crypto.h>
33#include <linux/fs_stack.h>
34#include <linux/slab.h>
35#include <linux/xattr.h>
36#include <asm/unaligned.h>
37#include "ecryptfs_kernel.h"
38
39static struct dentry *lock_parent(struct dentry *dentry)
40{
41 struct dentry *dir;
42
43 dir = dget_parent(dentry);
44 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
45 return dir;
46}
47
48static void unlock_dir(struct dentry *dir)
49{
50 mutex_unlock(&dir->d_inode->i_mutex);
51 dput(dir);
52}
53
54static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
55{
56 if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode)
57 return 1;
58 return 0;
59}
60
61static int ecryptfs_inode_set(struct inode *inode, void *opaque)
62{
63 struct inode *lower_inode = opaque;
64
65 ecryptfs_set_inode_lower(inode, lower_inode);
66 fsstack_copy_attr_all(inode, lower_inode);
67
68 fsstack_copy_inode_size(inode, lower_inode);
69 inode->i_ino = lower_inode->i_ino;
70 inode->i_version++;
71 inode->i_mapping->a_ops = &ecryptfs_aops;
72 inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
73
74 if (S_ISLNK(inode->i_mode))
75 inode->i_op = &ecryptfs_symlink_iops;
76 else if (S_ISDIR(inode->i_mode))
77 inode->i_op = &ecryptfs_dir_iops;
78 else
79 inode->i_op = &ecryptfs_main_iops;
80
81 if (S_ISDIR(inode->i_mode))
82 inode->i_fop = &ecryptfs_dir_fops;
83 else if (special_file(inode->i_mode))
84 init_special_inode(inode, inode->i_mode, inode->i_rdev);
85 else
86 inode->i_fop = &ecryptfs_main_fops;
87
88 return 0;
89}
90
91static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
92 struct super_block *sb)
93{
94 struct inode *inode;
95
96 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
97 return ERR_PTR(-EXDEV);
98 if (!igrab(lower_inode))
99 return ERR_PTR(-ESTALE);
100 inode = iget5_locked(sb, (unsigned long)lower_inode,
101 ecryptfs_inode_test, ecryptfs_inode_set,
102 lower_inode);
103 if (!inode) {
104 iput(lower_inode);
105 return ERR_PTR(-EACCES);
106 }
107 if (!(inode->i_state & I_NEW))
108 iput(lower_inode);
109
110 return inode;
111}
112
113struct inode *ecryptfs_get_inode(struct inode *lower_inode,
114 struct super_block *sb)
115{
116 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
117
118 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
119 unlock_new_inode(inode);
120
121 return inode;
122}
123
124
125
126
127
128
129
130
131
132
133
134static int ecryptfs_interpose(struct dentry *lower_dentry,
135 struct dentry *dentry, struct super_block *sb)
136{
137 struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb);
138
139 if (IS_ERR(inode))
140 return PTR_ERR(inode);
141 d_instantiate(dentry, inode);
142
143 return 0;
144}
145
146static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
147 struct inode *inode)
148{
149 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
150 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
151 struct dentry *lower_dir_dentry;
152 int rc;
153
154 dget(lower_dentry);
155 lower_dir_dentry = lock_parent(lower_dentry);
156 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
157 if (rc) {
158 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
159 goto out_unlock;
160 }
161 fsstack_copy_attr_times(dir, lower_dir_inode);
162 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
163 inode->i_ctime = dir->i_ctime;
164 d_drop(dentry);
165out_unlock:
166 unlock_dir(lower_dir_dentry);
167 dput(lower_dentry);
168 return rc;
169}
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184static struct inode *
185ecryptfs_do_create(struct inode *directory_inode,
186 struct dentry *ecryptfs_dentry, umode_t mode)
187{
188 int rc;
189 struct dentry *lower_dentry;
190 struct dentry *lower_dir_dentry;
191 struct inode *inode;
192
193 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
194 lower_dir_dentry = lock_parent(lower_dentry);
195 if (IS_ERR(lower_dir_dentry)) {
196 ecryptfs_printk(KERN_ERR, "Error locking directory of "
197 "dentry\n");
198 inode = ERR_CAST(lower_dir_dentry);
199 goto out;
200 }
201 rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, true);
202 if (rc) {
203 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
204 "rc = [%d]\n", __func__, rc);
205 inode = ERR_PTR(rc);
206 goto out_lock;
207 }
208 inode = __ecryptfs_get_inode(lower_dentry->d_inode,
209 directory_inode->i_sb);
210 if (IS_ERR(inode)) {
211 vfs_unlink(lower_dir_dentry->d_inode, lower_dentry, NULL);
212 goto out_lock;
213 }
214 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
215 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
216out_lock:
217 unlock_dir(lower_dir_dentry);
218out:
219 return inode;
220}
221
222
223
224
225
226
227
228
229
230int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
231 struct inode *ecryptfs_inode)
232{
233 struct ecryptfs_crypt_stat *crypt_stat =
234 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
235 int rc = 0;
236
237 if (S_ISDIR(ecryptfs_inode->i_mode)) {
238 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
239 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
240 goto out;
241 }
242 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
243 rc = ecryptfs_new_file_context(ecryptfs_inode);
244 if (rc) {
245 ecryptfs_printk(KERN_ERR, "Error creating new file "
246 "context; rc = [%d]\n", rc);
247 goto out;
248 }
249 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
250 if (rc) {
251 printk(KERN_ERR "%s: Error attempting to initialize "
252 "the lower file for the dentry with name "
253 "[%s]; rc = [%d]\n", __func__,
254 ecryptfs_dentry->d_name.name, rc);
255 goto out;
256 }
257 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
258 if (rc)
259 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
260 ecryptfs_put_lower_file(ecryptfs_inode);
261out:
262 return rc;
263}
264
265
266
267
268
269
270
271
272
273
274
275static int
276ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
277 umode_t mode, bool excl)
278{
279 struct inode *ecryptfs_inode;
280 int rc;
281
282 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
283 mode);
284 if (unlikely(IS_ERR(ecryptfs_inode))) {
285 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
286 "lower filesystem\n");
287 rc = PTR_ERR(ecryptfs_inode);
288 goto out;
289 }
290
291
292 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
293 if (rc) {
294 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
295 ecryptfs_inode);
296 make_bad_inode(ecryptfs_inode);
297 unlock_new_inode(ecryptfs_inode);
298 iput(ecryptfs_inode);
299 goto out;
300 }
301 unlock_new_inode(ecryptfs_inode);
302 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
303out:
304 return rc;
305}
306
307static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
308{
309 struct ecryptfs_crypt_stat *crypt_stat;
310 int rc;
311
312 rc = ecryptfs_get_lower_file(dentry, inode);
313 if (rc) {
314 printk(KERN_ERR "%s: Error attempting to initialize "
315 "the lower file for the dentry with name "
316 "[%s]; rc = [%d]\n", __func__,
317 dentry->d_name.name, rc);
318 return rc;
319 }
320
321 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
322
323 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
324 ecryptfs_set_default_sizes(crypt_stat);
325
326 rc = ecryptfs_read_and_validate_header_region(inode);
327 ecryptfs_put_lower_file(inode);
328 if (rc) {
329 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
330 if (!rc)
331 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
332 }
333
334
335 return 0;
336}
337
338
339
340
341static int ecryptfs_lookup_interpose(struct dentry *dentry,
342 struct dentry *lower_dentry,
343 struct inode *dir_inode)
344{
345 struct inode *inode, *lower_inode = lower_dentry->d_inode;
346 struct ecryptfs_dentry_info *dentry_info;
347 struct vfsmount *lower_mnt;
348 int rc = 0;
349
350 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
351 if (!dentry_info) {
352 printk(KERN_ERR "%s: Out of memory whilst attempting "
353 "to allocate ecryptfs_dentry_info struct\n",
354 __func__);
355 dput(lower_dentry);
356 return -ENOMEM;
357 }
358
359 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
360 fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
361 BUG_ON(!d_count(lower_dentry));
362
363 ecryptfs_set_dentry_private(dentry, dentry_info);
364 dentry_info->lower_path.mnt = lower_mnt;
365 dentry_info->lower_path.dentry = lower_dentry;
366
367 if (!lower_dentry->d_inode) {
368
369 d_add(dentry, NULL);
370 return 0;
371 }
372 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
373 if (IS_ERR(inode)) {
374 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
375 __func__, PTR_ERR(inode));
376 return PTR_ERR(inode);
377 }
378 if (S_ISREG(inode->i_mode)) {
379 rc = ecryptfs_i_size_read(dentry, inode);
380 if (rc) {
381 make_bad_inode(inode);
382 return rc;
383 }
384 }
385
386 if (inode->i_state & I_NEW)
387 unlock_new_inode(inode);
388 d_add(dentry, inode);
389
390 return rc;
391}
392
393
394
395
396
397
398
399
400
401
402static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
403 struct dentry *ecryptfs_dentry,
404 unsigned int flags)
405{
406 char *encrypted_and_encoded_name = NULL;
407 size_t encrypted_and_encoded_name_size;
408 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
409 struct dentry *lower_dir_dentry, *lower_dentry;
410 int rc = 0;
411
412 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
413 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
414 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
415 lower_dir_dentry,
416 ecryptfs_dentry->d_name.len);
417 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
418 if (IS_ERR(lower_dentry)) {
419 rc = PTR_ERR(lower_dentry);
420 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
421 "[%d] on lower_dentry = [%s]\n", __func__, rc,
422 ecryptfs_dentry->d_name.name);
423 goto out;
424 }
425 if (lower_dentry->d_inode)
426 goto interpose;
427 mount_crypt_stat = &ecryptfs_superblock_to_private(
428 ecryptfs_dentry->d_sb)->mount_crypt_stat;
429 if (!(mount_crypt_stat
430 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
431 goto interpose;
432 dput(lower_dentry);
433 rc = ecryptfs_encrypt_and_encode_filename(
434 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
435 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
436 ecryptfs_dentry->d_name.len);
437 if (rc) {
438 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
439 "filename; rc = [%d]\n", __func__, rc);
440 goto out;
441 }
442 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
443 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
444 lower_dir_dentry,
445 encrypted_and_encoded_name_size);
446 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
447 if (IS_ERR(lower_dentry)) {
448 rc = PTR_ERR(lower_dentry);
449 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
450 "[%d] on lower_dentry = [%s]\n", __func__, rc,
451 encrypted_and_encoded_name);
452 goto out;
453 }
454interpose:
455 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
456 ecryptfs_dir_inode);
457out:
458 kfree(encrypted_and_encoded_name);
459 return ERR_PTR(rc);
460}
461
462static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
463 struct dentry *new_dentry)
464{
465 struct dentry *lower_old_dentry;
466 struct dentry *lower_new_dentry;
467 struct dentry *lower_dir_dentry;
468 u64 file_size_save;
469 int rc;
470
471 file_size_save = i_size_read(old_dentry->d_inode);
472 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
473 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
474 dget(lower_old_dentry);
475 dget(lower_new_dentry);
476 lower_dir_dentry = lock_parent(lower_new_dentry);
477 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
478 lower_new_dentry, NULL);
479 if (rc || !lower_new_dentry->d_inode)
480 goto out_lock;
481 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
482 if (rc)
483 goto out_lock;
484 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
485 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
486 set_nlink(old_dentry->d_inode,
487 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink);
488 i_size_write(new_dentry->d_inode, file_size_save);
489out_lock:
490 unlock_dir(lower_dir_dentry);
491 dput(lower_new_dentry);
492 dput(lower_old_dentry);
493 return rc;
494}
495
496static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
497{
498 return ecryptfs_do_unlink(dir, dentry, dentry->d_inode);
499}
500
501static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
502 const char *symname)
503{
504 int rc;
505 struct dentry *lower_dentry;
506 struct dentry *lower_dir_dentry;
507 char *encoded_symname;
508 size_t encoded_symlen;
509 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
510
511 lower_dentry = ecryptfs_dentry_to_lower(dentry);
512 dget(lower_dentry);
513 lower_dir_dentry = lock_parent(lower_dentry);
514 mount_crypt_stat = &ecryptfs_superblock_to_private(
515 dir->i_sb)->mount_crypt_stat;
516 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
517 &encoded_symlen,
518 NULL,
519 mount_crypt_stat, symname,
520 strlen(symname));
521 if (rc)
522 goto out_lock;
523 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
524 encoded_symname);
525 kfree(encoded_symname);
526 if (rc || !lower_dentry->d_inode)
527 goto out_lock;
528 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
529 if (rc)
530 goto out_lock;
531 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
532 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
533out_lock:
534 unlock_dir(lower_dir_dentry);
535 dput(lower_dentry);
536 if (!dentry->d_inode)
537 d_drop(dentry);
538 return rc;
539}
540
541static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
542{
543 int rc;
544 struct dentry *lower_dentry;
545 struct dentry *lower_dir_dentry;
546
547 lower_dentry = ecryptfs_dentry_to_lower(dentry);
548 lower_dir_dentry = lock_parent(lower_dentry);
549 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
550 if (rc || !lower_dentry->d_inode)
551 goto out;
552 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
553 if (rc)
554 goto out;
555 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
556 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
557 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
558out:
559 unlock_dir(lower_dir_dentry);
560 if (!dentry->d_inode)
561 d_drop(dentry);
562 return rc;
563}
564
565static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
566{
567 struct dentry *lower_dentry;
568 struct dentry *lower_dir_dentry;
569 int rc;
570
571 lower_dentry = ecryptfs_dentry_to_lower(dentry);
572 dget(dentry);
573 lower_dir_dentry = lock_parent(lower_dentry);
574 dget(lower_dentry);
575 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
576 dput(lower_dentry);
577 if (!rc && dentry->d_inode)
578 clear_nlink(dentry->d_inode);
579 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
580 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
581 unlock_dir(lower_dir_dentry);
582 if (!rc)
583 d_drop(dentry);
584 dput(dentry);
585 return rc;
586}
587
588static int
589ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
590{
591 int rc;
592 struct dentry *lower_dentry;
593 struct dentry *lower_dir_dentry;
594
595 lower_dentry = ecryptfs_dentry_to_lower(dentry);
596 lower_dir_dentry = lock_parent(lower_dentry);
597 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
598 if (rc || !lower_dentry->d_inode)
599 goto out;
600 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
601 if (rc)
602 goto out;
603 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
604 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
605out:
606 unlock_dir(lower_dir_dentry);
607 if (!dentry->d_inode)
608 d_drop(dentry);
609 return rc;
610}
611
612static int
613ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
614 struct inode *new_dir, struct dentry *new_dentry)
615{
616 int rc;
617 struct dentry *lower_old_dentry;
618 struct dentry *lower_new_dentry;
619 struct dentry *lower_old_dir_dentry;
620 struct dentry *lower_new_dir_dentry;
621 struct dentry *trap = NULL;
622 struct inode *target_inode;
623
624 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
625 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
626 dget(lower_old_dentry);
627 dget(lower_new_dentry);
628 lower_old_dir_dentry = dget_parent(lower_old_dentry);
629 lower_new_dir_dentry = dget_parent(lower_new_dentry);
630 target_inode = new_dentry->d_inode;
631 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
632
633 if (trap == lower_old_dentry) {
634 rc = -EINVAL;
635 goto out_lock;
636 }
637
638 if (trap == lower_new_dentry) {
639 rc = -ENOTEMPTY;
640 goto out_lock;
641 }
642 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
643 lower_new_dir_dentry->d_inode, lower_new_dentry,
644 NULL, 0);
645 if (rc)
646 goto out_lock;
647 if (target_inode)
648 fsstack_copy_attr_all(target_inode,
649 ecryptfs_inode_to_lower(target_inode));
650 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
651 if (new_dir != old_dir)
652 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
653out_lock:
654 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
655 dput(lower_new_dir_dentry);
656 dput(lower_old_dir_dentry);
657 dput(lower_new_dentry);
658 dput(lower_old_dentry);
659 return rc;
660}
661
662static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
663{
664 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
665 char *lower_buf;
666 char *buf;
667 mm_segment_t old_fs;
668 int rc;
669
670 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
671 if (!lower_buf)
672 return ERR_PTR(-ENOMEM);
673 old_fs = get_fs();
674 set_fs(get_ds());
675 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
676 (char __user *)lower_buf,
677 PATH_MAX);
678 set_fs(old_fs);
679 if (rc < 0)
680 goto out;
681 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
682 lower_buf, rc);
683out:
684 kfree(lower_buf);
685 return rc ? ERR_PTR(rc) : buf;
686}
687
688static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
689{
690 size_t len;
691 char *buf = ecryptfs_readlink_lower(dentry, &len);
692 if (IS_ERR(buf))
693 goto out;
694 fsstack_copy_attr_atime(dentry->d_inode,
695 ecryptfs_dentry_to_lower(dentry)->d_inode);
696 buf[len] = '\0';
697out:
698 nd_set_link(nd, buf);
699 return NULL;
700}
701
702
703
704
705
706
707
708
709
710
711
712
713static loff_t
714upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
715 loff_t upper_size)
716{
717 loff_t lower_size;
718
719 lower_size = ecryptfs_lower_header_size(crypt_stat);
720 if (upper_size != 0) {
721 loff_t num_extents;
722
723 num_extents = upper_size >> crypt_stat->extent_shift;
724 if (upper_size & ~crypt_stat->extent_mask)
725 num_extents++;
726 lower_size += (num_extents * crypt_stat->extent_size);
727 }
728 return lower_size;
729}
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747static int truncate_upper(struct dentry *dentry, struct iattr *ia,
748 struct iattr *lower_ia)
749{
750 int rc = 0;
751 struct inode *inode = dentry->d_inode;
752 struct ecryptfs_crypt_stat *crypt_stat;
753 loff_t i_size = i_size_read(inode);
754 loff_t lower_size_before_truncate;
755 loff_t lower_size_after_truncate;
756
757 if (unlikely((ia->ia_size == i_size))) {
758 lower_ia->ia_valid &= ~ATTR_SIZE;
759 return 0;
760 }
761 rc = ecryptfs_get_lower_file(dentry, inode);
762 if (rc)
763 return rc;
764 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
765
766 if (ia->ia_size > i_size) {
767 char zero[] = { 0x00 };
768
769 lower_ia->ia_valid &= ~ATTR_SIZE;
770
771
772
773
774 rc = ecryptfs_write(inode, zero,
775 (ia->ia_size - 1), 1);
776 } else {
777
778
779
780
781 size_t num_zeros = (PAGE_CACHE_SIZE
782 - (ia->ia_size & ~PAGE_CACHE_MASK));
783
784 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
785 truncate_setsize(inode, ia->ia_size);
786 lower_ia->ia_size = ia->ia_size;
787 lower_ia->ia_valid |= ATTR_SIZE;
788 goto out;
789 }
790 if (num_zeros) {
791 char *zeros_virt;
792
793 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
794 if (!zeros_virt) {
795 rc = -ENOMEM;
796 goto out;
797 }
798 rc = ecryptfs_write(inode, zeros_virt,
799 ia->ia_size, num_zeros);
800 kfree(zeros_virt);
801 if (rc) {
802 printk(KERN_ERR "Error attempting to zero out "
803 "the remainder of the end page on "
804 "reducing truncate; rc = [%d]\n", rc);
805 goto out;
806 }
807 }
808 truncate_setsize(inode, ia->ia_size);
809 rc = ecryptfs_write_inode_size_to_metadata(inode);
810 if (rc) {
811 printk(KERN_ERR "Problem with "
812 "ecryptfs_write_inode_size_to_metadata; "
813 "rc = [%d]\n", rc);
814 goto out;
815 }
816
817
818 lower_size_before_truncate =
819 upper_size_to_lower_size(crypt_stat, i_size);
820 lower_size_after_truncate =
821 upper_size_to_lower_size(crypt_stat, ia->ia_size);
822 if (lower_size_after_truncate < lower_size_before_truncate) {
823 lower_ia->ia_size = lower_size_after_truncate;
824 lower_ia->ia_valid |= ATTR_SIZE;
825 } else
826 lower_ia->ia_valid &= ~ATTR_SIZE;
827 }
828out:
829 ecryptfs_put_lower_file(inode);
830 return rc;
831}
832
833static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
834{
835 struct ecryptfs_crypt_stat *crypt_stat;
836 loff_t lower_oldsize, lower_newsize;
837
838 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
839 lower_oldsize = upper_size_to_lower_size(crypt_stat,
840 i_size_read(inode));
841 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
842 if (lower_newsize > lower_oldsize) {
843
844
845
846
847
848
849 return inode_newsize_ok(inode, lower_newsize);
850 }
851
852 return 0;
853}
854
855
856
857
858
859
860
861
862
863
864
865int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
866{
867 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
868 struct iattr lower_ia = { .ia_valid = 0 };
869 int rc;
870
871 rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
872 if (rc)
873 return rc;
874
875 rc = truncate_upper(dentry, &ia, &lower_ia);
876 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
877 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
878
879 mutex_lock(&lower_dentry->d_inode->i_mutex);
880 rc = notify_change(lower_dentry, &lower_ia, NULL);
881 mutex_unlock(&lower_dentry->d_inode->i_mutex);
882 }
883 return rc;
884}
885
886static int
887ecryptfs_permission(struct inode *inode, int mask)
888{
889 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
890}
891
892
893
894
895
896
897
898
899
900
901
902
903
904static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
905{
906 int rc = 0;
907 struct dentry *lower_dentry;
908 struct iattr lower_ia;
909 struct inode *inode;
910 struct inode *lower_inode;
911 struct ecryptfs_crypt_stat *crypt_stat;
912
913 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
914 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
915 ecryptfs_init_crypt_stat(crypt_stat);
916 inode = dentry->d_inode;
917 lower_inode = ecryptfs_inode_to_lower(inode);
918 lower_dentry = ecryptfs_dentry_to_lower(dentry);
919 mutex_lock(&crypt_stat->cs_mutex);
920 if (S_ISDIR(dentry->d_inode->i_mode))
921 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
922 else if (S_ISREG(dentry->d_inode->i_mode)
923 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
924 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
925 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
926
927 mount_crypt_stat = &ecryptfs_superblock_to_private(
928 dentry->d_sb)->mount_crypt_stat;
929 rc = ecryptfs_get_lower_file(dentry, inode);
930 if (rc) {
931 mutex_unlock(&crypt_stat->cs_mutex);
932 goto out;
933 }
934 rc = ecryptfs_read_metadata(dentry);
935 ecryptfs_put_lower_file(inode);
936 if (rc) {
937 if (!(mount_crypt_stat->flags
938 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
939 rc = -EIO;
940 printk(KERN_WARNING "Either the lower file "
941 "is not in a valid eCryptfs format, "
942 "or the key could not be retrieved. "
943 "Plaintext passthrough mode is not "
944 "enabled; returning -EIO\n");
945 mutex_unlock(&crypt_stat->cs_mutex);
946 goto out;
947 }
948 rc = 0;
949 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
950 | ECRYPTFS_ENCRYPTED);
951 }
952 }
953 mutex_unlock(&crypt_stat->cs_mutex);
954
955 rc = inode_change_ok(inode, ia);
956 if (rc)
957 goto out;
958 if (ia->ia_valid & ATTR_SIZE) {
959 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
960 if (rc)
961 goto out;
962 }
963
964 memcpy(&lower_ia, ia, sizeof(lower_ia));
965 if (ia->ia_valid & ATTR_FILE)
966 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
967 if (ia->ia_valid & ATTR_SIZE) {
968 rc = truncate_upper(dentry, ia, &lower_ia);
969 if (rc < 0)
970 goto out;
971 }
972
973
974
975
976
977 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
978 lower_ia.ia_valid &= ~ATTR_MODE;
979
980 mutex_lock(&lower_dentry->d_inode->i_mutex);
981 rc = notify_change(lower_dentry, &lower_ia, NULL);
982 mutex_unlock(&lower_dentry->d_inode->i_mutex);
983out:
984 fsstack_copy_attr_all(inode, lower_inode);
985 return rc;
986}
987
988static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
989 struct kstat *stat)
990{
991 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
992 int rc = 0;
993
994 mount_crypt_stat = &ecryptfs_superblock_to_private(
995 dentry->d_sb)->mount_crypt_stat;
996 generic_fillattr(dentry->d_inode, stat);
997 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
998 char *target;
999 size_t targetsiz;
1000
1001 target = ecryptfs_readlink_lower(dentry, &targetsiz);
1002 if (!IS_ERR(target)) {
1003 kfree(target);
1004 stat->size = targetsiz;
1005 } else {
1006 rc = PTR_ERR(target);
1007 }
1008 }
1009 return rc;
1010}
1011
1012static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1013 struct kstat *stat)
1014{
1015 struct kstat lower_stat;
1016 int rc;
1017
1018 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
1019 if (!rc) {
1020 fsstack_copy_attr_all(dentry->d_inode,
1021 ecryptfs_inode_to_lower(dentry->d_inode));
1022 generic_fillattr(dentry->d_inode, stat);
1023 stat->blocks = lower_stat.blocks;
1024 }
1025 return rc;
1026}
1027
1028int
1029ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1030 size_t size, int flags)
1031{
1032 int rc = 0;
1033 struct dentry *lower_dentry;
1034
1035 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1036 if (!lower_dentry->d_inode->i_op->setxattr) {
1037 rc = -EOPNOTSUPP;
1038 goto out;
1039 }
1040
1041 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1042 if (!rc)
1043 fsstack_copy_attr_all(dentry->d_inode, lower_dentry->d_inode);
1044out:
1045 return rc;
1046}
1047
1048ssize_t
1049ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1050 void *value, size_t size)
1051{
1052 int rc = 0;
1053
1054 if (!lower_dentry->d_inode->i_op->getxattr) {
1055 rc = -EOPNOTSUPP;
1056 goto out;
1057 }
1058 mutex_lock(&lower_dentry->d_inode->i_mutex);
1059 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1060 size);
1061 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1062out:
1063 return rc;
1064}
1065
1066static ssize_t
1067ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1068 size_t size)
1069{
1070 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1071 value, size);
1072}
1073
1074static ssize_t
1075ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1076{
1077 int rc = 0;
1078 struct dentry *lower_dentry;
1079
1080 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1081 if (!lower_dentry->d_inode->i_op->listxattr) {
1082 rc = -EOPNOTSUPP;
1083 goto out;
1084 }
1085 mutex_lock(&lower_dentry->d_inode->i_mutex);
1086 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1087 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1088out:
1089 return rc;
1090}
1091
1092static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1093{
1094 int rc = 0;
1095 struct dentry *lower_dentry;
1096
1097 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1098 if (!lower_dentry->d_inode->i_op->removexattr) {
1099 rc = -EOPNOTSUPP;
1100 goto out;
1101 }
1102 mutex_lock(&lower_dentry->d_inode->i_mutex);
1103 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1104 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1105out:
1106 return rc;
1107}
1108
1109const struct inode_operations ecryptfs_symlink_iops = {
1110 .readlink = generic_readlink,
1111 .follow_link = ecryptfs_follow_link,
1112 .put_link = kfree_put_link,
1113 .permission = ecryptfs_permission,
1114 .setattr = ecryptfs_setattr,
1115 .getattr = ecryptfs_getattr_link,
1116 .setxattr = ecryptfs_setxattr,
1117 .getxattr = ecryptfs_getxattr,
1118 .listxattr = ecryptfs_listxattr,
1119 .removexattr = ecryptfs_removexattr
1120};
1121
1122const struct inode_operations ecryptfs_dir_iops = {
1123 .create = ecryptfs_create,
1124 .lookup = ecryptfs_lookup,
1125 .link = ecryptfs_link,
1126 .unlink = ecryptfs_unlink,
1127 .symlink = ecryptfs_symlink,
1128 .mkdir = ecryptfs_mkdir,
1129 .rmdir = ecryptfs_rmdir,
1130 .mknod = ecryptfs_mknod,
1131 .rename = ecryptfs_rename,
1132 .permission = ecryptfs_permission,
1133 .setattr = ecryptfs_setattr,
1134 .setxattr = ecryptfs_setxattr,
1135 .getxattr = ecryptfs_getxattr,
1136 .listxattr = ecryptfs_listxattr,
1137 .removexattr = ecryptfs_removexattr
1138};
1139
1140const struct inode_operations ecryptfs_main_iops = {
1141 .permission = ecryptfs_permission,
1142 .setattr = ecryptfs_setattr,
1143 .getattr = ecryptfs_getattr,
1144 .setxattr = ecryptfs_setxattr,
1145 .getxattr = ecryptfs_getxattr,
1146 .listxattr = ecryptfs_listxattr,
1147 .removexattr = ecryptfs_removexattr
1148};
1149