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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);
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);
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 ecryptfs_set_dentry_lower(dentry, lower_dentry);
365 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
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);
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 if (rc)
645 goto out_lock;
646 if (target_inode)
647 fsstack_copy_attr_all(target_inode,
648 ecryptfs_inode_to_lower(target_inode));
649 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
650 if (new_dir != old_dir)
651 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
652out_lock:
653 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
654 dput(lower_new_dir_dentry);
655 dput(lower_old_dir_dentry);
656 dput(lower_new_dentry);
657 dput(lower_old_dentry);
658 return rc;
659}
660
661static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
662 size_t *bufsiz)
663{
664 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
665 char *lower_buf;
666 mm_segment_t old_fs;
667 int rc;
668
669 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
670 if (!lower_buf) {
671 rc = -ENOMEM;
672 goto out;
673 }
674 old_fs = get_fs();
675 set_fs(get_ds());
676 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
677 (char __user *)lower_buf,
678 PATH_MAX);
679 set_fs(old_fs);
680 if (rc < 0)
681 goto out;
682 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry->d_sb,
683 lower_buf, rc);
684out:
685 kfree(lower_buf);
686 return rc;
687}
688
689static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
690{
691 char *buf;
692 size_t len = PATH_MAX;
693 int rc;
694
695 rc = ecryptfs_readlink_lower(dentry, &buf, &len);
696 if (rc)
697 goto out;
698 fsstack_copy_attr_atime(dentry->d_inode,
699 ecryptfs_dentry_to_lower(dentry)->d_inode);
700 buf[len] = '\0';
701out:
702 nd_set_link(nd, buf);
703 return NULL;
704}
705
706static void
707ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
708{
709 char *buf = nd_get_link(nd);
710 if (!IS_ERR(buf)) {
711
712 kfree(buf);
713 }
714}
715
716
717
718
719
720
721
722
723
724
725
726
727static loff_t
728upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
729 loff_t upper_size)
730{
731 loff_t lower_size;
732
733 lower_size = ecryptfs_lower_header_size(crypt_stat);
734 if (upper_size != 0) {
735 loff_t num_extents;
736
737 num_extents = upper_size >> crypt_stat->extent_shift;
738 if (upper_size & ~crypt_stat->extent_mask)
739 num_extents++;
740 lower_size += (num_extents * crypt_stat->extent_size);
741 }
742 return lower_size;
743}
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761static int truncate_upper(struct dentry *dentry, struct iattr *ia,
762 struct iattr *lower_ia)
763{
764 int rc = 0;
765 struct inode *inode = dentry->d_inode;
766 struct ecryptfs_crypt_stat *crypt_stat;
767 loff_t i_size = i_size_read(inode);
768 loff_t lower_size_before_truncate;
769 loff_t lower_size_after_truncate;
770
771 if (unlikely((ia->ia_size == i_size))) {
772 lower_ia->ia_valid &= ~ATTR_SIZE;
773 return 0;
774 }
775 rc = ecryptfs_get_lower_file(dentry, inode);
776 if (rc)
777 return rc;
778 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
779
780 if (ia->ia_size > i_size) {
781 char zero[] = { 0x00 };
782
783 lower_ia->ia_valid &= ~ATTR_SIZE;
784
785
786
787
788 rc = ecryptfs_write(inode, zero,
789 (ia->ia_size - 1), 1);
790 } else {
791
792
793
794
795 size_t num_zeros = (PAGE_CACHE_SIZE
796 - (ia->ia_size & ~PAGE_CACHE_MASK));
797
798 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
799 truncate_setsize(inode, ia->ia_size);
800 lower_ia->ia_size = ia->ia_size;
801 lower_ia->ia_valid |= ATTR_SIZE;
802 goto out;
803 }
804 if (num_zeros) {
805 char *zeros_virt;
806
807 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
808 if (!zeros_virt) {
809 rc = -ENOMEM;
810 goto out;
811 }
812 rc = ecryptfs_write(inode, zeros_virt,
813 ia->ia_size, num_zeros);
814 kfree(zeros_virt);
815 if (rc) {
816 printk(KERN_ERR "Error attempting to zero out "
817 "the remainder of the end page on "
818 "reducing truncate; rc = [%d]\n", rc);
819 goto out;
820 }
821 }
822 truncate_setsize(inode, ia->ia_size);
823 rc = ecryptfs_write_inode_size_to_metadata(inode);
824 if (rc) {
825 printk(KERN_ERR "Problem with "
826 "ecryptfs_write_inode_size_to_metadata; "
827 "rc = [%d]\n", rc);
828 goto out;
829 }
830
831
832 lower_size_before_truncate =
833 upper_size_to_lower_size(crypt_stat, i_size);
834 lower_size_after_truncate =
835 upper_size_to_lower_size(crypt_stat, ia->ia_size);
836 if (lower_size_after_truncate < lower_size_before_truncate) {
837 lower_ia->ia_size = lower_size_after_truncate;
838 lower_ia->ia_valid |= ATTR_SIZE;
839 } else
840 lower_ia->ia_valid &= ~ATTR_SIZE;
841 }
842out:
843 ecryptfs_put_lower_file(inode);
844 return rc;
845}
846
847static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
848{
849 struct ecryptfs_crypt_stat *crypt_stat;
850 loff_t lower_oldsize, lower_newsize;
851
852 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
853 lower_oldsize = upper_size_to_lower_size(crypt_stat,
854 i_size_read(inode));
855 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
856 if (lower_newsize > lower_oldsize) {
857
858
859
860
861
862
863 return inode_newsize_ok(inode, lower_newsize);
864 }
865
866 return 0;
867}
868
869
870
871
872
873
874
875
876
877
878
879int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
880{
881 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
882 struct iattr lower_ia = { .ia_valid = 0 };
883 int rc;
884
885 rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
886 if (rc)
887 return rc;
888
889 rc = truncate_upper(dentry, &ia, &lower_ia);
890 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
891 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
892
893 mutex_lock(&lower_dentry->d_inode->i_mutex);
894 rc = notify_change(lower_dentry, &lower_ia);
895 mutex_unlock(&lower_dentry->d_inode->i_mutex);
896 }
897 return rc;
898}
899
900static int
901ecryptfs_permission(struct inode *inode, int mask)
902{
903 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
904}
905
906
907
908
909
910
911
912
913
914
915
916
917
918static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
919{
920 int rc = 0;
921 struct dentry *lower_dentry;
922 struct iattr lower_ia;
923 struct inode *inode;
924 struct inode *lower_inode;
925 struct ecryptfs_crypt_stat *crypt_stat;
926
927 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
928 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
929 ecryptfs_init_crypt_stat(crypt_stat);
930 inode = dentry->d_inode;
931 lower_inode = ecryptfs_inode_to_lower(inode);
932 lower_dentry = ecryptfs_dentry_to_lower(dentry);
933 mutex_lock(&crypt_stat->cs_mutex);
934 if (S_ISDIR(dentry->d_inode->i_mode))
935 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
936 else if (S_ISREG(dentry->d_inode->i_mode)
937 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
938 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
939 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
940
941 mount_crypt_stat = &ecryptfs_superblock_to_private(
942 dentry->d_sb)->mount_crypt_stat;
943 rc = ecryptfs_get_lower_file(dentry, inode);
944 if (rc) {
945 mutex_unlock(&crypt_stat->cs_mutex);
946 goto out;
947 }
948 rc = ecryptfs_read_metadata(dentry);
949 ecryptfs_put_lower_file(inode);
950 if (rc) {
951 if (!(mount_crypt_stat->flags
952 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
953 rc = -EIO;
954 printk(KERN_WARNING "Either the lower file "
955 "is not in a valid eCryptfs format, "
956 "or the key could not be retrieved. "
957 "Plaintext passthrough mode is not "
958 "enabled; returning -EIO\n");
959 mutex_unlock(&crypt_stat->cs_mutex);
960 goto out;
961 }
962 rc = 0;
963 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
964 | ECRYPTFS_ENCRYPTED);
965 }
966 }
967 mutex_unlock(&crypt_stat->cs_mutex);
968
969 rc = inode_change_ok(inode, ia);
970 if (rc)
971 goto out;
972 if (ia->ia_valid & ATTR_SIZE) {
973 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
974 if (rc)
975 goto out;
976 }
977
978 memcpy(&lower_ia, ia, sizeof(lower_ia));
979 if (ia->ia_valid & ATTR_FILE)
980 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
981 if (ia->ia_valid & ATTR_SIZE) {
982 rc = truncate_upper(dentry, ia, &lower_ia);
983 if (rc < 0)
984 goto out;
985 }
986
987
988
989
990
991 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
992 lower_ia.ia_valid &= ~ATTR_MODE;
993
994 mutex_lock(&lower_dentry->d_inode->i_mutex);
995 rc = notify_change(lower_dentry, &lower_ia);
996 mutex_unlock(&lower_dentry->d_inode->i_mutex);
997out:
998 fsstack_copy_attr_all(inode, lower_inode);
999 return rc;
1000}
1001
1002static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
1003 struct kstat *stat)
1004{
1005 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1006 int rc = 0;
1007
1008 mount_crypt_stat = &ecryptfs_superblock_to_private(
1009 dentry->d_sb)->mount_crypt_stat;
1010 generic_fillattr(dentry->d_inode, stat);
1011 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1012 char *target;
1013 size_t targetsiz;
1014
1015 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
1016 if (!rc) {
1017 kfree(target);
1018 stat->size = targetsiz;
1019 }
1020 }
1021 return rc;
1022}
1023
1024static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1025 struct kstat *stat)
1026{
1027 struct kstat lower_stat;
1028 int rc;
1029
1030 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
1031 if (!rc) {
1032 fsstack_copy_attr_all(dentry->d_inode,
1033 ecryptfs_inode_to_lower(dentry->d_inode));
1034 generic_fillattr(dentry->d_inode, stat);
1035 stat->blocks = lower_stat.blocks;
1036 }
1037 return rc;
1038}
1039
1040int
1041ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1042 size_t size, int flags)
1043{
1044 int rc = 0;
1045 struct dentry *lower_dentry;
1046
1047 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1048 if (!lower_dentry->d_inode->i_op->setxattr) {
1049 rc = -EOPNOTSUPP;
1050 goto out;
1051 }
1052
1053 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1054 if (!rc)
1055 fsstack_copy_attr_all(dentry->d_inode, lower_dentry->d_inode);
1056out:
1057 return rc;
1058}
1059
1060ssize_t
1061ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1062 void *value, size_t size)
1063{
1064 int rc = 0;
1065
1066 if (!lower_dentry->d_inode->i_op->getxattr) {
1067 rc = -EOPNOTSUPP;
1068 goto out;
1069 }
1070 mutex_lock(&lower_dentry->d_inode->i_mutex);
1071 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1072 size);
1073 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1074out:
1075 return rc;
1076}
1077
1078static ssize_t
1079ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1080 size_t size)
1081{
1082 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1083 value, size);
1084}
1085
1086static ssize_t
1087ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1088{
1089 int rc = 0;
1090 struct dentry *lower_dentry;
1091
1092 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1093 if (!lower_dentry->d_inode->i_op->listxattr) {
1094 rc = -EOPNOTSUPP;
1095 goto out;
1096 }
1097 mutex_lock(&lower_dentry->d_inode->i_mutex);
1098 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1099 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1100out:
1101 return rc;
1102}
1103
1104static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1105{
1106 int rc = 0;
1107 struct dentry *lower_dentry;
1108
1109 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1110 if (!lower_dentry->d_inode->i_op->removexattr) {
1111 rc = -EOPNOTSUPP;
1112 goto out;
1113 }
1114 mutex_lock(&lower_dentry->d_inode->i_mutex);
1115 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1116 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1117out:
1118 return rc;
1119}
1120
1121const struct inode_operations ecryptfs_symlink_iops = {
1122 .readlink = generic_readlink,
1123 .follow_link = ecryptfs_follow_link,
1124 .put_link = ecryptfs_put_link,
1125 .permission = ecryptfs_permission,
1126 .setattr = ecryptfs_setattr,
1127 .getattr = ecryptfs_getattr_link,
1128 .setxattr = ecryptfs_setxattr,
1129 .getxattr = ecryptfs_getxattr,
1130 .listxattr = ecryptfs_listxattr,
1131 .removexattr = ecryptfs_removexattr
1132};
1133
1134const struct inode_operations ecryptfs_dir_iops = {
1135 .create = ecryptfs_create,
1136 .lookup = ecryptfs_lookup,
1137 .link = ecryptfs_link,
1138 .unlink = ecryptfs_unlink,
1139 .symlink = ecryptfs_symlink,
1140 .mkdir = ecryptfs_mkdir,
1141 .rmdir = ecryptfs_rmdir,
1142 .mknod = ecryptfs_mknod,
1143 .rename = ecryptfs_rename,
1144 .permission = ecryptfs_permission,
1145 .setattr = ecryptfs_setattr,
1146 .setxattr = ecryptfs_setxattr,
1147 .getxattr = ecryptfs_getxattr,
1148 .listxattr = ecryptfs_listxattr,
1149 .removexattr = ecryptfs_removexattr
1150};
1151
1152const struct inode_operations ecryptfs_main_iops = {
1153 .permission = ecryptfs_permission,
1154 .setattr = ecryptfs_setattr,
1155 .getattr = ecryptfs_getattr,
1156 .setxattr = ecryptfs_setxattr,
1157 .getxattr = ecryptfs_getxattr,
1158 .listxattr = ecryptfs_listxattr,
1159 .removexattr = ecryptfs_removexattr
1160};
1161