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1/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 * 02111-1307, USA.
24 */
25
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/fs_stack.h>
33#include <linux/slab.h>
34#include <linux/xattr.h>
35#include <asm/unaligned.h>
36#include "ecryptfs_kernel.h"
37
38static struct dentry *lock_parent(struct dentry *dentry)
39{
40 struct dentry *dir;
41
42 dir = dget_parent(dentry);
43 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
44 return dir;
45}
46
47static void unlock_dir(struct dentry *dir)
48{
49 inode_unlock(d_inode(dir));
50 dput(dir);
51}
52
53static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
54{
55 return ecryptfs_inode_to_lower(inode) == lower_inode;
56}
57
58static int ecryptfs_inode_set(struct inode *inode, void *opaque)
59{
60 struct inode *lower_inode = opaque;
61
62 ecryptfs_set_inode_lower(inode, lower_inode);
63 fsstack_copy_attr_all(inode, lower_inode);
64 /* i_size will be overwritten for encrypted regular files */
65 fsstack_copy_inode_size(inode, lower_inode);
66 inode->i_ino = lower_inode->i_ino;
67 inode->i_version++;
68 inode->i_mapping->a_ops = &ecryptfs_aops;
69
70 if (S_ISLNK(inode->i_mode))
71 inode->i_op = &ecryptfs_symlink_iops;
72 else if (S_ISDIR(inode->i_mode))
73 inode->i_op = &ecryptfs_dir_iops;
74 else
75 inode->i_op = &ecryptfs_main_iops;
76
77 if (S_ISDIR(inode->i_mode))
78 inode->i_fop = &ecryptfs_dir_fops;
79 else if (special_file(inode->i_mode))
80 init_special_inode(inode, inode->i_mode, inode->i_rdev);
81 else
82 inode->i_fop = &ecryptfs_main_fops;
83
84 return 0;
85}
86
87static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
88 struct super_block *sb)
89{
90 struct inode *inode;
91
92 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
93 return ERR_PTR(-EXDEV);
94 if (!igrab(lower_inode))
95 return ERR_PTR(-ESTALE);
96 inode = iget5_locked(sb, (unsigned long)lower_inode,
97 ecryptfs_inode_test, ecryptfs_inode_set,
98 lower_inode);
99 if (!inode) {
100 iput(lower_inode);
101 return ERR_PTR(-EACCES);
102 }
103 if (!(inode->i_state & I_NEW))
104 iput(lower_inode);
105
106 return inode;
107}
108
109struct inode *ecryptfs_get_inode(struct inode *lower_inode,
110 struct super_block *sb)
111{
112 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
113
114 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
115 unlock_new_inode(inode);
116
117 return inode;
118}
119
120/**
121 * ecryptfs_interpose
122 * @lower_dentry: Existing dentry in the lower filesystem
123 * @dentry: ecryptfs' dentry
124 * @sb: ecryptfs's super_block
125 *
126 * Interposes upper and lower dentries.
127 *
128 * Returns zero on success; non-zero otherwise
129 */
130static int ecryptfs_interpose(struct dentry *lower_dentry,
131 struct dentry *dentry, struct super_block *sb)
132{
133 struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
134
135 if (IS_ERR(inode))
136 return PTR_ERR(inode);
137 d_instantiate(dentry, inode);
138
139 return 0;
140}
141
142static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
143 struct inode *inode)
144{
145 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
146 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
147 struct dentry *lower_dir_dentry;
148 int rc;
149
150 dget(lower_dentry);
151 lower_dir_dentry = lock_parent(lower_dentry);
152 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
153 if (rc) {
154 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
155 goto out_unlock;
156 }
157 fsstack_copy_attr_times(dir, lower_dir_inode);
158 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
159 inode->i_ctime = dir->i_ctime;
160 d_drop(dentry);
161out_unlock:
162 unlock_dir(lower_dir_dentry);
163 dput(lower_dentry);
164 return rc;
165}
166
167/**
168 * ecryptfs_do_create
169 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
170 * @ecryptfs_dentry: New file's dentry in ecryptfs
171 * @mode: The mode of the new file
172 *
173 * Creates the underlying file and the eCryptfs inode which will link to
174 * it. It will also update the eCryptfs directory inode to mimic the
175 * stat of the lower directory inode.
176 *
177 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
178 */
179static struct inode *
180ecryptfs_do_create(struct inode *directory_inode,
181 struct dentry *ecryptfs_dentry, umode_t mode)
182{
183 int rc;
184 struct dentry *lower_dentry;
185 struct dentry *lower_dir_dentry;
186 struct inode *inode;
187
188 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
189 lower_dir_dentry = lock_parent(lower_dentry);
190 rc = vfs_create(d_inode(lower_dir_dentry), lower_dentry, mode, true);
191 if (rc) {
192 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
193 "rc = [%d]\n", __func__, rc);
194 inode = ERR_PTR(rc);
195 goto out_lock;
196 }
197 inode = __ecryptfs_get_inode(d_inode(lower_dentry),
198 directory_inode->i_sb);
199 if (IS_ERR(inode)) {
200 vfs_unlink(d_inode(lower_dir_dentry), lower_dentry, NULL);
201 goto out_lock;
202 }
203 fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry));
204 fsstack_copy_inode_size(directory_inode, d_inode(lower_dir_dentry));
205out_lock:
206 unlock_dir(lower_dir_dentry);
207 return inode;
208}
209
210/**
211 * ecryptfs_initialize_file
212 *
213 * Cause the file to be changed from a basic empty file to an ecryptfs
214 * file with a header and first data page.
215 *
216 * Returns zero on success
217 */
218int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
219 struct inode *ecryptfs_inode)
220{
221 struct ecryptfs_crypt_stat *crypt_stat =
222 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
223 int rc = 0;
224
225 if (S_ISDIR(ecryptfs_inode->i_mode)) {
226 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
227 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
228 goto out;
229 }
230 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
231 rc = ecryptfs_new_file_context(ecryptfs_inode);
232 if (rc) {
233 ecryptfs_printk(KERN_ERR, "Error creating new file "
234 "context; rc = [%d]\n", rc);
235 goto out;
236 }
237 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
238 if (rc) {
239 printk(KERN_ERR "%s: Error attempting to initialize "
240 "the lower file for the dentry with name "
241 "[%pd]; rc = [%d]\n", __func__,
242 ecryptfs_dentry, rc);
243 goto out;
244 }
245 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
246 if (rc)
247 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
248 ecryptfs_put_lower_file(ecryptfs_inode);
249out:
250 return rc;
251}
252
253/**
254 * ecryptfs_create
255 * @dir: The inode of the directory in which to create the file.
256 * @dentry: The eCryptfs dentry
257 * @mode: The mode of the new file.
258 *
259 * Creates a new file.
260 *
261 * Returns zero on success; non-zero on error condition
262 */
263static int
264ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
265 umode_t mode, bool excl)
266{
267 struct inode *ecryptfs_inode;
268 int rc;
269
270 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
271 mode);
272 if (IS_ERR(ecryptfs_inode)) {
273 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
274 "lower filesystem\n");
275 rc = PTR_ERR(ecryptfs_inode);
276 goto out;
277 }
278 /* At this point, a file exists on "disk"; we need to make sure
279 * that this on disk file is prepared to be an ecryptfs file */
280 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
281 if (rc) {
282 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
283 ecryptfs_inode);
284 iget_failed(ecryptfs_inode);
285 goto out;
286 }
287 unlock_new_inode(ecryptfs_inode);
288 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
289out:
290 return rc;
291}
292
293static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
294{
295 struct ecryptfs_crypt_stat *crypt_stat;
296 int rc;
297
298 rc = ecryptfs_get_lower_file(dentry, inode);
299 if (rc) {
300 printk(KERN_ERR "%s: Error attempting to initialize "
301 "the lower file for the dentry with name "
302 "[%pd]; rc = [%d]\n", __func__,
303 dentry, rc);
304 return rc;
305 }
306
307 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
308 /* TODO: lock for crypt_stat comparison */
309 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
310 ecryptfs_set_default_sizes(crypt_stat);
311
312 rc = ecryptfs_read_and_validate_header_region(inode);
313 ecryptfs_put_lower_file(inode);
314 if (rc) {
315 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
316 if (!rc)
317 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
318 }
319
320 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
321 return 0;
322}
323
324/**
325 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
326 */
327static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
328 struct dentry *lower_dentry)
329{
330 struct inode *inode, *lower_inode = d_inode(lower_dentry);
331 struct ecryptfs_dentry_info *dentry_info;
332 struct vfsmount *lower_mnt;
333 int rc = 0;
334
335 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
336 if (!dentry_info) {
337 printk(KERN_ERR "%s: Out of memory whilst attempting "
338 "to allocate ecryptfs_dentry_info struct\n",
339 __func__);
340 dput(lower_dentry);
341 return ERR_PTR(-ENOMEM);
342 }
343
344 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
345 fsstack_copy_attr_atime(d_inode(dentry->d_parent),
346 d_inode(lower_dentry->d_parent));
347 BUG_ON(!d_count(lower_dentry));
348
349 ecryptfs_set_dentry_private(dentry, dentry_info);
350 dentry_info->lower_path.mnt = lower_mnt;
351 dentry_info->lower_path.dentry = lower_dentry;
352
353 if (d_really_is_negative(lower_dentry)) {
354 /* We want to add because we couldn't find in lower */
355 d_add(dentry, NULL);
356 return NULL;
357 }
358 inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
359 if (IS_ERR(inode)) {
360 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
361 __func__, PTR_ERR(inode));
362 return ERR_CAST(inode);
363 }
364 if (S_ISREG(inode->i_mode)) {
365 rc = ecryptfs_i_size_read(dentry, inode);
366 if (rc) {
367 make_bad_inode(inode);
368 return ERR_PTR(rc);
369 }
370 }
371
372 if (inode->i_state & I_NEW)
373 unlock_new_inode(inode);
374 return d_splice_alias(inode, dentry);
375}
376
377/**
378 * ecryptfs_lookup
379 * @ecryptfs_dir_inode: The eCryptfs directory inode
380 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
381 * @flags: lookup flags
382 *
383 * Find a file on disk. If the file does not exist, then we'll add it to the
384 * dentry cache and continue on to read it from the disk.
385 */
386static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
387 struct dentry *ecryptfs_dentry,
388 unsigned int flags)
389{
390 char *encrypted_and_encoded_name = NULL;
391 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
392 struct dentry *lower_dir_dentry, *lower_dentry;
393 const char *name = ecryptfs_dentry->d_name.name;
394 size_t len = ecryptfs_dentry->d_name.len;
395 struct dentry *res;
396 int rc = 0;
397
398 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
399
400 mount_crypt_stat = &ecryptfs_superblock_to_private(
401 ecryptfs_dentry->d_sb)->mount_crypt_stat;
402 if (mount_crypt_stat
403 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)) {
404 rc = ecryptfs_encrypt_and_encode_filename(
405 &encrypted_and_encoded_name, &len,
406 mount_crypt_stat, name, len);
407 if (rc) {
408 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
409 "filename; rc = [%d]\n", __func__, rc);
410 return ERR_PTR(rc);
411 }
412 name = encrypted_and_encoded_name;
413 }
414
415 lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
416 if (IS_ERR(lower_dentry)) {
417 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
418 "[%ld] on lower_dentry = [%s]\n", __func__,
419 PTR_ERR(lower_dentry),
420 name);
421 res = ERR_CAST(lower_dentry);
422 } else {
423 res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
424 }
425 kfree(encrypted_and_encoded_name);
426 return res;
427}
428
429static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
430 struct dentry *new_dentry)
431{
432 struct dentry *lower_old_dentry;
433 struct dentry *lower_new_dentry;
434 struct dentry *lower_dir_dentry;
435 u64 file_size_save;
436 int rc;
437
438 file_size_save = i_size_read(d_inode(old_dentry));
439 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
440 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
441 dget(lower_old_dentry);
442 dget(lower_new_dentry);
443 lower_dir_dentry = lock_parent(lower_new_dentry);
444 rc = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry),
445 lower_new_dentry, NULL);
446 if (rc || d_really_is_negative(lower_new_dentry))
447 goto out_lock;
448 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
449 if (rc)
450 goto out_lock;
451 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
452 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
453 set_nlink(d_inode(old_dentry),
454 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
455 i_size_write(d_inode(new_dentry), file_size_save);
456out_lock:
457 unlock_dir(lower_dir_dentry);
458 dput(lower_new_dentry);
459 dput(lower_old_dentry);
460 return rc;
461}
462
463static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
464{
465 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
466}
467
468static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
469 const char *symname)
470{
471 int rc;
472 struct dentry *lower_dentry;
473 struct dentry *lower_dir_dentry;
474 char *encoded_symname;
475 size_t encoded_symlen;
476 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
477
478 lower_dentry = ecryptfs_dentry_to_lower(dentry);
479 dget(lower_dentry);
480 lower_dir_dentry = lock_parent(lower_dentry);
481 mount_crypt_stat = &ecryptfs_superblock_to_private(
482 dir->i_sb)->mount_crypt_stat;
483 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
484 &encoded_symlen,
485 mount_crypt_stat, symname,
486 strlen(symname));
487 if (rc)
488 goto out_lock;
489 rc = vfs_symlink(d_inode(lower_dir_dentry), lower_dentry,
490 encoded_symname);
491 kfree(encoded_symname);
492 if (rc || d_really_is_negative(lower_dentry))
493 goto out_lock;
494 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
495 if (rc)
496 goto out_lock;
497 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
498 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
499out_lock:
500 unlock_dir(lower_dir_dentry);
501 dput(lower_dentry);
502 if (d_really_is_negative(dentry))
503 d_drop(dentry);
504 return rc;
505}
506
507static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
508{
509 int rc;
510 struct dentry *lower_dentry;
511 struct dentry *lower_dir_dentry;
512
513 lower_dentry = ecryptfs_dentry_to_lower(dentry);
514 lower_dir_dentry = lock_parent(lower_dentry);
515 rc = vfs_mkdir(d_inode(lower_dir_dentry), lower_dentry, mode);
516 if (rc || d_really_is_negative(lower_dentry))
517 goto out;
518 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
519 if (rc)
520 goto out;
521 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
522 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
523 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
524out:
525 unlock_dir(lower_dir_dentry);
526 if (d_really_is_negative(dentry))
527 d_drop(dentry);
528 return rc;
529}
530
531static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
532{
533 struct dentry *lower_dentry;
534 struct dentry *lower_dir_dentry;
535 int rc;
536
537 lower_dentry = ecryptfs_dentry_to_lower(dentry);
538 dget(dentry);
539 lower_dir_dentry = lock_parent(lower_dentry);
540 dget(lower_dentry);
541 rc = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry);
542 dput(lower_dentry);
543 if (!rc && d_really_is_positive(dentry))
544 clear_nlink(d_inode(dentry));
545 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
546 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
547 unlock_dir(lower_dir_dentry);
548 if (!rc)
549 d_drop(dentry);
550 dput(dentry);
551 return rc;
552}
553
554static int
555ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
556{
557 int rc;
558 struct dentry *lower_dentry;
559 struct dentry *lower_dir_dentry;
560
561 lower_dentry = ecryptfs_dentry_to_lower(dentry);
562 lower_dir_dentry = lock_parent(lower_dentry);
563 rc = vfs_mknod(d_inode(lower_dir_dentry), lower_dentry, mode, dev);
564 if (rc || d_really_is_negative(lower_dentry))
565 goto out;
566 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
567 if (rc)
568 goto out;
569 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
570 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
571out:
572 unlock_dir(lower_dir_dentry);
573 if (d_really_is_negative(dentry))
574 d_drop(dentry);
575 return rc;
576}
577
578static int
579ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
580 struct inode *new_dir, struct dentry *new_dentry,
581 unsigned int flags)
582{
583 int rc;
584 struct dentry *lower_old_dentry;
585 struct dentry *lower_new_dentry;
586 struct dentry *lower_old_dir_dentry;
587 struct dentry *lower_new_dir_dentry;
588 struct dentry *trap = NULL;
589 struct inode *target_inode;
590
591 if (flags)
592 return -EINVAL;
593
594 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
595 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
596 dget(lower_old_dentry);
597 dget(lower_new_dentry);
598 lower_old_dir_dentry = dget_parent(lower_old_dentry);
599 lower_new_dir_dentry = dget_parent(lower_new_dentry);
600 target_inode = d_inode(new_dentry);
601 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
602 /* source should not be ancestor of target */
603 if (trap == lower_old_dentry) {
604 rc = -EINVAL;
605 goto out_lock;
606 }
607 /* target should not be ancestor of source */
608 if (trap == lower_new_dentry) {
609 rc = -ENOTEMPTY;
610 goto out_lock;
611 }
612 rc = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry,
613 d_inode(lower_new_dir_dentry), lower_new_dentry,
614 NULL, 0);
615 if (rc)
616 goto out_lock;
617 if (target_inode)
618 fsstack_copy_attr_all(target_inode,
619 ecryptfs_inode_to_lower(target_inode));
620 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
621 if (new_dir != old_dir)
622 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
623out_lock:
624 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
625 dput(lower_new_dir_dentry);
626 dput(lower_old_dir_dentry);
627 dput(lower_new_dentry);
628 dput(lower_old_dentry);
629 return rc;
630}
631
632static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
633{
634 DEFINE_DELAYED_CALL(done);
635 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
636 const char *link;
637 char *buf;
638 int rc;
639
640 link = vfs_get_link(lower_dentry, &done);
641 if (IS_ERR(link))
642 return ERR_CAST(link);
643
644 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
645 link, strlen(link));
646 do_delayed_call(&done);
647 if (rc)
648 return ERR_PTR(rc);
649
650 return buf;
651}
652
653static const char *ecryptfs_get_link(struct dentry *dentry,
654 struct inode *inode,
655 struct delayed_call *done)
656{
657 size_t len;
658 char *buf;
659
660 if (!dentry)
661 return ERR_PTR(-ECHILD);
662
663 buf = ecryptfs_readlink_lower(dentry, &len);
664 if (IS_ERR(buf))
665 return buf;
666 fsstack_copy_attr_atime(d_inode(dentry),
667 d_inode(ecryptfs_dentry_to_lower(dentry)));
668 buf[len] = '\0';
669 set_delayed_call(done, kfree_link, buf);
670 return buf;
671}
672
673/**
674 * upper_size_to_lower_size
675 * @crypt_stat: Crypt_stat associated with file
676 * @upper_size: Size of the upper file
677 *
678 * Calculate the required size of the lower file based on the
679 * specified size of the upper file. This calculation is based on the
680 * number of headers in the underlying file and the extent size.
681 *
682 * Returns Calculated size of the lower file.
683 */
684static loff_t
685upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
686 loff_t upper_size)
687{
688 loff_t lower_size;
689
690 lower_size = ecryptfs_lower_header_size(crypt_stat);
691 if (upper_size != 0) {
692 loff_t num_extents;
693
694 num_extents = upper_size >> crypt_stat->extent_shift;
695 if (upper_size & ~crypt_stat->extent_mask)
696 num_extents++;
697 lower_size += (num_extents * crypt_stat->extent_size);
698 }
699 return lower_size;
700}
701
702/**
703 * truncate_upper
704 * @dentry: The ecryptfs layer dentry
705 * @ia: Address of the ecryptfs inode's attributes
706 * @lower_ia: Address of the lower inode's attributes
707 *
708 * Function to handle truncations modifying the size of the file. Note
709 * that the file sizes are interpolated. When expanding, we are simply
710 * writing strings of 0's out. When truncating, we truncate the upper
711 * inode and update the lower_ia according to the page index
712 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
713 * the caller must use lower_ia in a call to notify_change() to perform
714 * the truncation of the lower inode.
715 *
716 * Returns zero on success; non-zero otherwise
717 */
718static int truncate_upper(struct dentry *dentry, struct iattr *ia,
719 struct iattr *lower_ia)
720{
721 int rc = 0;
722 struct inode *inode = d_inode(dentry);
723 struct ecryptfs_crypt_stat *crypt_stat;
724 loff_t i_size = i_size_read(inode);
725 loff_t lower_size_before_truncate;
726 loff_t lower_size_after_truncate;
727
728 if (unlikely((ia->ia_size == i_size))) {
729 lower_ia->ia_valid &= ~ATTR_SIZE;
730 return 0;
731 }
732 rc = ecryptfs_get_lower_file(dentry, inode);
733 if (rc)
734 return rc;
735 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
736 /* Switch on growing or shrinking file */
737 if (ia->ia_size > i_size) {
738 char zero[] = { 0x00 };
739
740 lower_ia->ia_valid &= ~ATTR_SIZE;
741 /* Write a single 0 at the last position of the file;
742 * this triggers code that will fill in 0's throughout
743 * the intermediate portion of the previous end of the
744 * file and the new and of the file */
745 rc = ecryptfs_write(inode, zero,
746 (ia->ia_size - 1), 1);
747 } else { /* ia->ia_size < i_size_read(inode) */
748 /* We're chopping off all the pages down to the page
749 * in which ia->ia_size is located. Fill in the end of
750 * that page from (ia->ia_size & ~PAGE_MASK) to
751 * PAGE_SIZE with zeros. */
752 size_t num_zeros = (PAGE_SIZE
753 - (ia->ia_size & ~PAGE_MASK));
754
755 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
756 truncate_setsize(inode, ia->ia_size);
757 lower_ia->ia_size = ia->ia_size;
758 lower_ia->ia_valid |= ATTR_SIZE;
759 goto out;
760 }
761 if (num_zeros) {
762 char *zeros_virt;
763
764 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
765 if (!zeros_virt) {
766 rc = -ENOMEM;
767 goto out;
768 }
769 rc = ecryptfs_write(inode, zeros_virt,
770 ia->ia_size, num_zeros);
771 kfree(zeros_virt);
772 if (rc) {
773 printk(KERN_ERR "Error attempting to zero out "
774 "the remainder of the end page on "
775 "reducing truncate; rc = [%d]\n", rc);
776 goto out;
777 }
778 }
779 truncate_setsize(inode, ia->ia_size);
780 rc = ecryptfs_write_inode_size_to_metadata(inode);
781 if (rc) {
782 printk(KERN_ERR "Problem with "
783 "ecryptfs_write_inode_size_to_metadata; "
784 "rc = [%d]\n", rc);
785 goto out;
786 }
787 /* We are reducing the size of the ecryptfs file, and need to
788 * know if we need to reduce the size of the lower file. */
789 lower_size_before_truncate =
790 upper_size_to_lower_size(crypt_stat, i_size);
791 lower_size_after_truncate =
792 upper_size_to_lower_size(crypt_stat, ia->ia_size);
793 if (lower_size_after_truncate < lower_size_before_truncate) {
794 lower_ia->ia_size = lower_size_after_truncate;
795 lower_ia->ia_valid |= ATTR_SIZE;
796 } else
797 lower_ia->ia_valid &= ~ATTR_SIZE;
798 }
799out:
800 ecryptfs_put_lower_file(inode);
801 return rc;
802}
803
804static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
805{
806 struct ecryptfs_crypt_stat *crypt_stat;
807 loff_t lower_oldsize, lower_newsize;
808
809 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
810 lower_oldsize = upper_size_to_lower_size(crypt_stat,
811 i_size_read(inode));
812 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
813 if (lower_newsize > lower_oldsize) {
814 /*
815 * The eCryptfs inode and the new *lower* size are mixed here
816 * because we may not have the lower i_mutex held and/or it may
817 * not be appropriate to call inode_newsize_ok() with inodes
818 * from other filesystems.
819 */
820 return inode_newsize_ok(inode, lower_newsize);
821 }
822
823 return 0;
824}
825
826/**
827 * ecryptfs_truncate
828 * @dentry: The ecryptfs layer dentry
829 * @new_length: The length to expand the file to
830 *
831 * Simple function that handles the truncation of an eCryptfs inode and
832 * its corresponding lower inode.
833 *
834 * Returns zero on success; non-zero otherwise
835 */
836int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
837{
838 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
839 struct iattr lower_ia = { .ia_valid = 0 };
840 int rc;
841
842 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
843 if (rc)
844 return rc;
845
846 rc = truncate_upper(dentry, &ia, &lower_ia);
847 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
848 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
849
850 inode_lock(d_inode(lower_dentry));
851 rc = notify_change(lower_dentry, &lower_ia, NULL);
852 inode_unlock(d_inode(lower_dentry));
853 }
854 return rc;
855}
856
857static int
858ecryptfs_permission(struct inode *inode, int mask)
859{
860 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
861}
862
863/**
864 * ecryptfs_setattr
865 * @dentry: dentry handle to the inode to modify
866 * @ia: Structure with flags of what to change and values
867 *
868 * Updates the metadata of an inode. If the update is to the size
869 * i.e. truncation, then ecryptfs_truncate will handle the size modification
870 * of both the ecryptfs inode and the lower inode.
871 *
872 * All other metadata changes will be passed right to the lower filesystem,
873 * and we will just update our inode to look like the lower.
874 */
875static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
876{
877 int rc = 0;
878 struct dentry *lower_dentry;
879 struct iattr lower_ia;
880 struct inode *inode;
881 struct inode *lower_inode;
882 struct ecryptfs_crypt_stat *crypt_stat;
883
884 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
885 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
886 rc = ecryptfs_init_crypt_stat(crypt_stat);
887 if (rc)
888 return rc;
889 }
890 inode = d_inode(dentry);
891 lower_inode = ecryptfs_inode_to_lower(inode);
892 lower_dentry = ecryptfs_dentry_to_lower(dentry);
893 mutex_lock(&crypt_stat->cs_mutex);
894 if (d_is_dir(dentry))
895 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
896 else if (d_is_reg(dentry)
897 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
898 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
899 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
900
901 mount_crypt_stat = &ecryptfs_superblock_to_private(
902 dentry->d_sb)->mount_crypt_stat;
903 rc = ecryptfs_get_lower_file(dentry, inode);
904 if (rc) {
905 mutex_unlock(&crypt_stat->cs_mutex);
906 goto out;
907 }
908 rc = ecryptfs_read_metadata(dentry);
909 ecryptfs_put_lower_file(inode);
910 if (rc) {
911 if (!(mount_crypt_stat->flags
912 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
913 rc = -EIO;
914 printk(KERN_WARNING "Either the lower file "
915 "is not in a valid eCryptfs format, "
916 "or the key could not be retrieved. "
917 "Plaintext passthrough mode is not "
918 "enabled; returning -EIO\n");
919 mutex_unlock(&crypt_stat->cs_mutex);
920 goto out;
921 }
922 rc = 0;
923 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
924 | ECRYPTFS_ENCRYPTED);
925 }
926 }
927 mutex_unlock(&crypt_stat->cs_mutex);
928
929 rc = setattr_prepare(dentry, ia);
930 if (rc)
931 goto out;
932 if (ia->ia_valid & ATTR_SIZE) {
933 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
934 if (rc)
935 goto out;
936 }
937
938 memcpy(&lower_ia, ia, sizeof(lower_ia));
939 if (ia->ia_valid & ATTR_FILE)
940 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
941 if (ia->ia_valid & ATTR_SIZE) {
942 rc = truncate_upper(dentry, ia, &lower_ia);
943 if (rc < 0)
944 goto out;
945 }
946
947 /*
948 * mode change is for clearing setuid/setgid bits. Allow lower fs
949 * to interpret this in its own way.
950 */
951 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
952 lower_ia.ia_valid &= ~ATTR_MODE;
953
954 inode_lock(d_inode(lower_dentry));
955 rc = notify_change(lower_dentry, &lower_ia, NULL);
956 inode_unlock(d_inode(lower_dentry));
957out:
958 fsstack_copy_attr_all(inode, lower_inode);
959 return rc;
960}
961
962static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
963 struct kstat *stat)
964{
965 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
966 int rc = 0;
967
968 mount_crypt_stat = &ecryptfs_superblock_to_private(
969 dentry->d_sb)->mount_crypt_stat;
970 generic_fillattr(d_inode(dentry), stat);
971 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
972 char *target;
973 size_t targetsiz;
974
975 target = ecryptfs_readlink_lower(dentry, &targetsiz);
976 if (!IS_ERR(target)) {
977 kfree(target);
978 stat->size = targetsiz;
979 } else {
980 rc = PTR_ERR(target);
981 }
982 }
983 return rc;
984}
985
986static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
987 struct kstat *stat)
988{
989 struct kstat lower_stat;
990 int rc;
991
992 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
993 if (!rc) {
994 fsstack_copy_attr_all(d_inode(dentry),
995 ecryptfs_inode_to_lower(d_inode(dentry)));
996 generic_fillattr(d_inode(dentry), stat);
997 stat->blocks = lower_stat.blocks;
998 }
999 return rc;
1000}
1001
1002int
1003ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
1004 const char *name, const void *value,
1005 size_t size, int flags)
1006{
1007 int rc;
1008 struct dentry *lower_dentry;
1009
1010 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1011 if (!(d_inode(lower_dentry)->i_opflags & IOP_XATTR)) {
1012 rc = -EOPNOTSUPP;
1013 goto out;
1014 }
1015 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1016 if (!rc && inode)
1017 fsstack_copy_attr_all(inode, d_inode(lower_dentry));
1018out:
1019 return rc;
1020}
1021
1022ssize_t
1023ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
1024 const char *name, void *value, size_t size)
1025{
1026 int rc;
1027
1028 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1029 rc = -EOPNOTSUPP;
1030 goto out;
1031 }
1032 inode_lock(lower_inode);
1033 rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
1034 inode_unlock(lower_inode);
1035out:
1036 return rc;
1037}
1038
1039static ssize_t
1040ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
1041 const char *name, void *value, size_t size)
1042{
1043 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
1044 ecryptfs_inode_to_lower(inode),
1045 name, value, size);
1046}
1047
1048static ssize_t
1049ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1050{
1051 int rc = 0;
1052 struct dentry *lower_dentry;
1053
1054 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1055 if (!d_inode(lower_dentry)->i_op->listxattr) {
1056 rc = -EOPNOTSUPP;
1057 goto out;
1058 }
1059 inode_lock(d_inode(lower_dentry));
1060 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1061 inode_unlock(d_inode(lower_dentry));
1062out:
1063 return rc;
1064}
1065
1066static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
1067 const char *name)
1068{
1069 int rc;
1070 struct dentry *lower_dentry;
1071 struct inode *lower_inode;
1072
1073 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1074 lower_inode = ecryptfs_inode_to_lower(inode);
1075 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1076 rc = -EOPNOTSUPP;
1077 goto out;
1078 }
1079 inode_lock(lower_inode);
1080 rc = __vfs_removexattr(lower_dentry, name);
1081 inode_unlock(lower_inode);
1082out:
1083 return rc;
1084}
1085
1086const struct inode_operations ecryptfs_symlink_iops = {
1087 .get_link = ecryptfs_get_link,
1088 .permission = ecryptfs_permission,
1089 .setattr = ecryptfs_setattr,
1090 .getattr = ecryptfs_getattr_link,
1091 .listxattr = ecryptfs_listxattr,
1092};
1093
1094const struct inode_operations ecryptfs_dir_iops = {
1095 .create = ecryptfs_create,
1096 .lookup = ecryptfs_lookup,
1097 .link = ecryptfs_link,
1098 .unlink = ecryptfs_unlink,
1099 .symlink = ecryptfs_symlink,
1100 .mkdir = ecryptfs_mkdir,
1101 .rmdir = ecryptfs_rmdir,
1102 .mknod = ecryptfs_mknod,
1103 .rename = ecryptfs_rename,
1104 .permission = ecryptfs_permission,
1105 .setattr = ecryptfs_setattr,
1106 .listxattr = ecryptfs_listxattr,
1107};
1108
1109const struct inode_operations ecryptfs_main_iops = {
1110 .permission = ecryptfs_permission,
1111 .setattr = ecryptfs_setattr,
1112 .getattr = ecryptfs_getattr,
1113 .listxattr = ecryptfs_listxattr,
1114};
1115
1116static int ecryptfs_xattr_get(const struct xattr_handler *handler,
1117 struct dentry *dentry, struct inode *inode,
1118 const char *name, void *buffer, size_t size)
1119{
1120 return ecryptfs_getxattr(dentry, inode, name, buffer, size);
1121}
1122
1123static int ecryptfs_xattr_set(const struct xattr_handler *handler,
1124 struct dentry *dentry, struct inode *inode,
1125 const char *name, const void *value, size_t size,
1126 int flags)
1127{
1128 if (value)
1129 return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
1130 else {
1131 BUG_ON(flags != XATTR_REPLACE);
1132 return ecryptfs_removexattr(dentry, inode, name);
1133 }
1134}
1135
1136const struct xattr_handler ecryptfs_xattr_handler = {
1137 .prefix = "", /* match anything */
1138 .get = ecryptfs_xattr_get,
1139 .set = ecryptfs_xattr_set,
1140};
1141
1142const struct xattr_handler *ecryptfs_xattr_handlers[] = {
1143 &ecryptfs_xattr_handler,
1144 NULL
1145};
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * eCryptfs: Linux filesystem encryption layer
4 *
5 * Copyright (C) 1997-2004 Erez Zadok
6 * Copyright (C) 2001-2004 Stony Brook University
7 * Copyright (C) 2004-2007 International Business Machines Corp.
8 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
9 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 */
11
12#include <linux/file.h>
13#include <linux/vmalloc.h>
14#include <linux/pagemap.h>
15#include <linux/dcache.h>
16#include <linux/namei.h>
17#include <linux/mount.h>
18#include <linux/fs_stack.h>
19#include <linux/slab.h>
20#include <linux/xattr.h>
21#include <linux/posix_acl.h>
22#include <linux/posix_acl_xattr.h>
23#include <linux/fileattr.h>
24#include <linux/unaligned.h>
25#include "ecryptfs_kernel.h"
26
27static int lock_parent(struct dentry *dentry,
28 struct dentry **lower_dentry,
29 struct inode **lower_dir)
30{
31 struct dentry *lower_dir_dentry;
32
33 lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
34 *lower_dir = d_inode(lower_dir_dentry);
35 *lower_dentry = ecryptfs_dentry_to_lower(dentry);
36
37 inode_lock_nested(*lower_dir, I_MUTEX_PARENT);
38 return (*lower_dentry)->d_parent == lower_dir_dentry ? 0 : -EINVAL;
39}
40
41static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
42{
43 return ecryptfs_inode_to_lower(inode) == lower_inode;
44}
45
46static int ecryptfs_inode_set(struct inode *inode, void *opaque)
47{
48 struct inode *lower_inode = opaque;
49
50 ecryptfs_set_inode_lower(inode, lower_inode);
51 fsstack_copy_attr_all(inode, lower_inode);
52 /* i_size will be overwritten for encrypted regular files */
53 fsstack_copy_inode_size(inode, lower_inode);
54 inode->i_ino = lower_inode->i_ino;
55 inode->i_mapping->a_ops = &ecryptfs_aops;
56
57 if (S_ISLNK(inode->i_mode))
58 inode->i_op = &ecryptfs_symlink_iops;
59 else if (S_ISDIR(inode->i_mode))
60 inode->i_op = &ecryptfs_dir_iops;
61 else
62 inode->i_op = &ecryptfs_main_iops;
63
64 if (S_ISDIR(inode->i_mode))
65 inode->i_fop = &ecryptfs_dir_fops;
66 else if (special_file(inode->i_mode))
67 init_special_inode(inode, inode->i_mode, inode->i_rdev);
68 else
69 inode->i_fop = &ecryptfs_main_fops;
70
71 return 0;
72}
73
74static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
75 struct super_block *sb)
76{
77 struct inode *inode;
78
79 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
80 return ERR_PTR(-EXDEV);
81
82 /* Reject dealing with casefold directories. */
83 if (IS_CASEFOLDED(lower_inode)) {
84 pr_err_ratelimited("%s: Can't handle casefolded directory.\n",
85 __func__);
86 return ERR_PTR(-EREMOTE);
87 }
88
89 if (!igrab(lower_inode))
90 return ERR_PTR(-ESTALE);
91 inode = iget5_locked(sb, (unsigned long)lower_inode,
92 ecryptfs_inode_test, ecryptfs_inode_set,
93 lower_inode);
94 if (!inode) {
95 iput(lower_inode);
96 return ERR_PTR(-EACCES);
97 }
98 if (!(inode->i_state & I_NEW))
99 iput(lower_inode);
100
101 return inode;
102}
103
104struct inode *ecryptfs_get_inode(struct inode *lower_inode,
105 struct super_block *sb)
106{
107 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
108
109 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
110 unlock_new_inode(inode);
111
112 return inode;
113}
114
115/**
116 * ecryptfs_interpose
117 * @lower_dentry: Existing dentry in the lower filesystem
118 * @dentry: ecryptfs' dentry
119 * @sb: ecryptfs's super_block
120 *
121 * Interposes upper and lower dentries.
122 *
123 * Returns zero on success; non-zero otherwise
124 */
125static int ecryptfs_interpose(struct dentry *lower_dentry,
126 struct dentry *dentry, struct super_block *sb)
127{
128 struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
129
130 if (IS_ERR(inode))
131 return PTR_ERR(inode);
132 d_instantiate(dentry, inode);
133
134 return 0;
135}
136
137static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
138 struct inode *inode)
139{
140 struct dentry *lower_dentry;
141 struct inode *lower_dir;
142 int rc;
143
144 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
145 dget(lower_dentry); // don't even try to make the lower negative
146 if (!rc) {
147 if (d_unhashed(lower_dentry))
148 rc = -EINVAL;
149 else
150 rc = vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry,
151 NULL);
152 }
153 if (rc) {
154 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
155 goto out_unlock;
156 }
157 fsstack_copy_attr_times(dir, lower_dir);
158 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
159 inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
160out_unlock:
161 dput(lower_dentry);
162 inode_unlock(lower_dir);
163 if (!rc)
164 d_drop(dentry);
165 return rc;
166}
167
168/**
169 * ecryptfs_do_create
170 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
171 * @ecryptfs_dentry: New file's dentry in ecryptfs
172 * @mode: The mode of the new file
173 *
174 * Creates the underlying file and the eCryptfs inode which will link to
175 * it. It will also update the eCryptfs directory inode to mimic the
176 * stat of the lower directory inode.
177 *
178 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
179 */
180static struct inode *
181ecryptfs_do_create(struct inode *directory_inode,
182 struct dentry *ecryptfs_dentry, umode_t mode)
183{
184 int rc;
185 struct dentry *lower_dentry;
186 struct inode *lower_dir;
187 struct inode *inode;
188
189 rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
190 if (!rc)
191 rc = vfs_create(&nop_mnt_idmap, lower_dir,
192 lower_dentry, mode, true);
193 if (rc) {
194 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
195 "rc = [%d]\n", __func__, rc);
196 inode = ERR_PTR(rc);
197 goto out_lock;
198 }
199 inode = __ecryptfs_get_inode(d_inode(lower_dentry),
200 directory_inode->i_sb);
201 if (IS_ERR(inode)) {
202 vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry, NULL);
203 goto out_lock;
204 }
205 fsstack_copy_attr_times(directory_inode, lower_dir);
206 fsstack_copy_inode_size(directory_inode, lower_dir);
207out_lock:
208 inode_unlock(lower_dir);
209 return inode;
210}
211
212/*
213 * ecryptfs_initialize_file
214 *
215 * Cause the file to be changed from a basic empty file to an ecryptfs
216 * file with a header and first data page.
217 *
218 * Returns zero on success
219 */
220int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
221 struct inode *ecryptfs_inode)
222{
223 struct ecryptfs_crypt_stat *crypt_stat =
224 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
225 int rc = 0;
226
227 if (S_ISDIR(ecryptfs_inode->i_mode)) {
228 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
229 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
230 goto out;
231 }
232 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
233 rc = ecryptfs_new_file_context(ecryptfs_inode);
234 if (rc) {
235 ecryptfs_printk(KERN_ERR, "Error creating new file "
236 "context; rc = [%d]\n", rc);
237 goto out;
238 }
239 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
240 if (rc) {
241 printk(KERN_ERR "%s: Error attempting to initialize "
242 "the lower file for the dentry with name "
243 "[%pd]; rc = [%d]\n", __func__,
244 ecryptfs_dentry, rc);
245 goto out;
246 }
247 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
248 if (rc)
249 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
250 ecryptfs_put_lower_file(ecryptfs_inode);
251out:
252 return rc;
253}
254
255/*
256 * ecryptfs_create
257 * @mode: The mode of the new file.
258 *
259 * Creates a new file.
260 *
261 * Returns zero on success; non-zero on error condition
262 */
263static int
264ecryptfs_create(struct mnt_idmap *idmap,
265 struct inode *directory_inode, struct dentry *ecryptfs_dentry,
266 umode_t mode, bool excl)
267{
268 struct inode *ecryptfs_inode;
269 int rc;
270
271 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
272 mode);
273 if (IS_ERR(ecryptfs_inode)) {
274 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
275 "lower filesystem\n");
276 rc = PTR_ERR(ecryptfs_inode);
277 goto out;
278 }
279 /* At this point, a file exists on "disk"; we need to make sure
280 * that this on disk file is prepared to be an ecryptfs file */
281 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
282 if (rc) {
283 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
284 ecryptfs_inode);
285 iget_failed(ecryptfs_inode);
286 goto out;
287 }
288 d_instantiate_new(ecryptfs_dentry, ecryptfs_inode);
289out:
290 return rc;
291}
292
293static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
294{
295 struct ecryptfs_crypt_stat *crypt_stat;
296 int rc;
297
298 rc = ecryptfs_get_lower_file(dentry, inode);
299 if (rc) {
300 printk(KERN_ERR "%s: Error attempting to initialize "
301 "the lower file for the dentry with name "
302 "[%pd]; rc = [%d]\n", __func__,
303 dentry, rc);
304 return rc;
305 }
306
307 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
308 /* TODO: lock for crypt_stat comparison */
309 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
310 ecryptfs_set_default_sizes(crypt_stat);
311
312 rc = ecryptfs_read_and_validate_header_region(inode);
313 ecryptfs_put_lower_file(inode);
314 if (rc) {
315 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
316 if (!rc)
317 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
318 }
319
320 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
321 return 0;
322}
323
324/*
325 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
326 */
327static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
328 struct dentry *lower_dentry)
329{
330 const struct path *path = ecryptfs_dentry_to_lower_path(dentry->d_parent);
331 struct inode *inode, *lower_inode;
332 struct ecryptfs_dentry_info *dentry_info;
333 int rc = 0;
334
335 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
336 if (!dentry_info) {
337 dput(lower_dentry);
338 return ERR_PTR(-ENOMEM);
339 }
340
341 fsstack_copy_attr_atime(d_inode(dentry->d_parent),
342 d_inode(path->dentry));
343 BUG_ON(!d_count(lower_dentry));
344
345 ecryptfs_set_dentry_private(dentry, dentry_info);
346 dentry_info->lower_path.mnt = mntget(path->mnt);
347 dentry_info->lower_path.dentry = lower_dentry;
348
349 /*
350 * negative dentry can go positive under us here - its parent is not
351 * locked. That's OK and that could happen just as we return from
352 * ecryptfs_lookup() anyway. Just need to be careful and fetch
353 * ->d_inode only once - it's not stable here.
354 */
355 lower_inode = READ_ONCE(lower_dentry->d_inode);
356
357 if (!lower_inode) {
358 /* We want to add because we couldn't find in lower */
359 d_add(dentry, NULL);
360 return NULL;
361 }
362 inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
363 if (IS_ERR(inode)) {
364 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
365 __func__, PTR_ERR(inode));
366 return ERR_CAST(inode);
367 }
368 if (S_ISREG(inode->i_mode)) {
369 rc = ecryptfs_i_size_read(dentry, inode);
370 if (rc) {
371 make_bad_inode(inode);
372 return ERR_PTR(rc);
373 }
374 }
375
376 if (inode->i_state & I_NEW)
377 unlock_new_inode(inode);
378 return d_splice_alias(inode, dentry);
379}
380
381/**
382 * ecryptfs_lookup
383 * @ecryptfs_dir_inode: The eCryptfs directory inode
384 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
385 * @flags: lookup flags
386 *
387 * Find a file on disk. If the file does not exist, then we'll add it to the
388 * dentry cache and continue on to read it from the disk.
389 */
390static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
391 struct dentry *ecryptfs_dentry,
392 unsigned int flags)
393{
394 char *encrypted_and_encoded_name = NULL;
395 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
396 struct dentry *lower_dir_dentry, *lower_dentry;
397 const char *name = ecryptfs_dentry->d_name.name;
398 size_t len = ecryptfs_dentry->d_name.len;
399 struct dentry *res;
400 int rc = 0;
401
402 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
403
404 mount_crypt_stat = &ecryptfs_superblock_to_private(
405 ecryptfs_dentry->d_sb)->mount_crypt_stat;
406 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
407 rc = ecryptfs_encrypt_and_encode_filename(
408 &encrypted_and_encoded_name, &len,
409 mount_crypt_stat, name, len);
410 if (rc) {
411 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
412 "filename; rc = [%d]\n", __func__, rc);
413 return ERR_PTR(rc);
414 }
415 name = encrypted_and_encoded_name;
416 }
417
418 lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
419 if (IS_ERR(lower_dentry)) {
420 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
421 "[%ld] on lower_dentry = [%s]\n", __func__,
422 PTR_ERR(lower_dentry),
423 name);
424 res = ERR_CAST(lower_dentry);
425 } else {
426 res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
427 }
428 kfree(encrypted_and_encoded_name);
429 return res;
430}
431
432static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
433 struct dentry *new_dentry)
434{
435 struct dentry *lower_old_dentry;
436 struct dentry *lower_new_dentry;
437 struct inode *lower_dir;
438 u64 file_size_save;
439 int rc;
440
441 file_size_save = i_size_read(d_inode(old_dentry));
442 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
443 rc = lock_parent(new_dentry, &lower_new_dentry, &lower_dir);
444 if (!rc)
445 rc = vfs_link(lower_old_dentry, &nop_mnt_idmap, lower_dir,
446 lower_new_dentry, NULL);
447 if (rc || d_really_is_negative(lower_new_dentry))
448 goto out_lock;
449 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
450 if (rc)
451 goto out_lock;
452 fsstack_copy_attr_times(dir, lower_dir);
453 fsstack_copy_inode_size(dir, lower_dir);
454 set_nlink(d_inode(old_dentry),
455 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
456 i_size_write(d_inode(new_dentry), file_size_save);
457out_lock:
458 inode_unlock(lower_dir);
459 return rc;
460}
461
462static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
463{
464 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
465}
466
467static int ecryptfs_symlink(struct mnt_idmap *idmap,
468 struct inode *dir, struct dentry *dentry,
469 const char *symname)
470{
471 int rc;
472 struct dentry *lower_dentry;
473 struct inode *lower_dir;
474 char *encoded_symname;
475 size_t encoded_symlen;
476 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
477
478 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
479 if (rc)
480 goto out_lock;
481 mount_crypt_stat = &ecryptfs_superblock_to_private(
482 dir->i_sb)->mount_crypt_stat;
483 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
484 &encoded_symlen,
485 mount_crypt_stat, symname,
486 strlen(symname));
487 if (rc)
488 goto out_lock;
489 rc = vfs_symlink(&nop_mnt_idmap, lower_dir, lower_dentry,
490 encoded_symname);
491 kfree(encoded_symname);
492 if (rc || d_really_is_negative(lower_dentry))
493 goto out_lock;
494 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
495 if (rc)
496 goto out_lock;
497 fsstack_copy_attr_times(dir, lower_dir);
498 fsstack_copy_inode_size(dir, lower_dir);
499out_lock:
500 inode_unlock(lower_dir);
501 if (d_really_is_negative(dentry))
502 d_drop(dentry);
503 return rc;
504}
505
506static int ecryptfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
507 struct dentry *dentry, umode_t mode)
508{
509 int rc;
510 struct dentry *lower_dentry;
511 struct inode *lower_dir;
512
513 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
514 if (!rc)
515 rc = vfs_mkdir(&nop_mnt_idmap, lower_dir,
516 lower_dentry, mode);
517 if (rc || d_really_is_negative(lower_dentry))
518 goto out;
519 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
520 if (rc)
521 goto out;
522 fsstack_copy_attr_times(dir, lower_dir);
523 fsstack_copy_inode_size(dir, lower_dir);
524 set_nlink(dir, lower_dir->i_nlink);
525out:
526 inode_unlock(lower_dir);
527 if (d_really_is_negative(dentry))
528 d_drop(dentry);
529 return rc;
530}
531
532static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
533{
534 struct dentry *lower_dentry;
535 struct inode *lower_dir;
536 int rc;
537
538 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
539 dget(lower_dentry); // don't even try to make the lower negative
540 if (!rc) {
541 if (d_unhashed(lower_dentry))
542 rc = -EINVAL;
543 else
544 rc = vfs_rmdir(&nop_mnt_idmap, lower_dir, lower_dentry);
545 }
546 if (!rc) {
547 clear_nlink(d_inode(dentry));
548 fsstack_copy_attr_times(dir, lower_dir);
549 set_nlink(dir, lower_dir->i_nlink);
550 }
551 dput(lower_dentry);
552 inode_unlock(lower_dir);
553 if (!rc)
554 d_drop(dentry);
555 return rc;
556}
557
558static int
559ecryptfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
560 struct dentry *dentry, umode_t mode, dev_t dev)
561{
562 int rc;
563 struct dentry *lower_dentry;
564 struct inode *lower_dir;
565
566 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
567 if (!rc)
568 rc = vfs_mknod(&nop_mnt_idmap, lower_dir,
569 lower_dentry, mode, dev);
570 if (rc || d_really_is_negative(lower_dentry))
571 goto out;
572 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
573 if (rc)
574 goto out;
575 fsstack_copy_attr_times(dir, lower_dir);
576 fsstack_copy_inode_size(dir, lower_dir);
577out:
578 inode_unlock(lower_dir);
579 if (d_really_is_negative(dentry))
580 d_drop(dentry);
581 return rc;
582}
583
584static int
585ecryptfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
586 struct dentry *old_dentry, struct inode *new_dir,
587 struct dentry *new_dentry, unsigned int flags)
588{
589 int rc;
590 struct dentry *lower_old_dentry;
591 struct dentry *lower_new_dentry;
592 struct dentry *lower_old_dir_dentry;
593 struct dentry *lower_new_dir_dentry;
594 struct dentry *trap;
595 struct inode *target_inode;
596 struct renamedata rd = {};
597
598 if (flags)
599 return -EINVAL;
600
601 lower_old_dir_dentry = ecryptfs_dentry_to_lower(old_dentry->d_parent);
602 lower_new_dir_dentry = ecryptfs_dentry_to_lower(new_dentry->d_parent);
603
604 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
605 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
606
607 target_inode = d_inode(new_dentry);
608
609 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
610 if (IS_ERR(trap))
611 return PTR_ERR(trap);
612 dget(lower_new_dentry);
613 rc = -EINVAL;
614 if (lower_old_dentry->d_parent != lower_old_dir_dentry)
615 goto out_lock;
616 if (lower_new_dentry->d_parent != lower_new_dir_dentry)
617 goto out_lock;
618 if (d_unhashed(lower_old_dentry) || d_unhashed(lower_new_dentry))
619 goto out_lock;
620 /* source should not be ancestor of target */
621 if (trap == lower_old_dentry)
622 goto out_lock;
623 /* target should not be ancestor of source */
624 if (trap == lower_new_dentry) {
625 rc = -ENOTEMPTY;
626 goto out_lock;
627 }
628
629 rd.old_mnt_idmap = &nop_mnt_idmap;
630 rd.old_dir = d_inode(lower_old_dir_dentry);
631 rd.old_dentry = lower_old_dentry;
632 rd.new_mnt_idmap = &nop_mnt_idmap;
633 rd.new_dir = d_inode(lower_new_dir_dentry);
634 rd.new_dentry = lower_new_dentry;
635 rc = vfs_rename(&rd);
636 if (rc)
637 goto out_lock;
638 if (target_inode)
639 fsstack_copy_attr_all(target_inode,
640 ecryptfs_inode_to_lower(target_inode));
641 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
642 if (new_dir != old_dir)
643 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
644out_lock:
645 dput(lower_new_dentry);
646 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
647 return rc;
648}
649
650static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
651{
652 DEFINE_DELAYED_CALL(done);
653 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
654 const char *link;
655 char *buf;
656 int rc;
657
658 link = vfs_get_link(lower_dentry, &done);
659 if (IS_ERR(link))
660 return ERR_CAST(link);
661
662 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
663 link, strlen(link));
664 do_delayed_call(&done);
665 if (rc)
666 return ERR_PTR(rc);
667
668 return buf;
669}
670
671static const char *ecryptfs_get_link(struct dentry *dentry,
672 struct inode *inode,
673 struct delayed_call *done)
674{
675 size_t len;
676 char *buf;
677
678 if (!dentry)
679 return ERR_PTR(-ECHILD);
680
681 buf = ecryptfs_readlink_lower(dentry, &len);
682 if (IS_ERR(buf))
683 return buf;
684 fsstack_copy_attr_atime(d_inode(dentry),
685 d_inode(ecryptfs_dentry_to_lower(dentry)));
686 buf[len] = '\0';
687 set_delayed_call(done, kfree_link, buf);
688 return buf;
689}
690
691/**
692 * upper_size_to_lower_size
693 * @crypt_stat: Crypt_stat associated with file
694 * @upper_size: Size of the upper file
695 *
696 * Calculate the required size of the lower file based on the
697 * specified size of the upper file. This calculation is based on the
698 * number of headers in the underlying file and the extent size.
699 *
700 * Returns Calculated size of the lower file.
701 */
702static loff_t
703upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
704 loff_t upper_size)
705{
706 loff_t lower_size;
707
708 lower_size = ecryptfs_lower_header_size(crypt_stat);
709 if (upper_size != 0) {
710 loff_t num_extents;
711
712 num_extents = upper_size >> crypt_stat->extent_shift;
713 if (upper_size & ~crypt_stat->extent_mask)
714 num_extents++;
715 lower_size += (num_extents * crypt_stat->extent_size);
716 }
717 return lower_size;
718}
719
720/**
721 * truncate_upper
722 * @dentry: The ecryptfs layer dentry
723 * @ia: Address of the ecryptfs inode's attributes
724 * @lower_ia: Address of the lower inode's attributes
725 *
726 * Function to handle truncations modifying the size of the file. Note
727 * that the file sizes are interpolated. When expanding, we are simply
728 * writing strings of 0's out. When truncating, we truncate the upper
729 * inode and update the lower_ia according to the page index
730 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
731 * the caller must use lower_ia in a call to notify_change() to perform
732 * the truncation of the lower inode.
733 *
734 * Returns zero on success; non-zero otherwise
735 */
736static int truncate_upper(struct dentry *dentry, struct iattr *ia,
737 struct iattr *lower_ia)
738{
739 int rc = 0;
740 struct inode *inode = d_inode(dentry);
741 struct ecryptfs_crypt_stat *crypt_stat;
742 loff_t i_size = i_size_read(inode);
743 loff_t lower_size_before_truncate;
744 loff_t lower_size_after_truncate;
745
746 if (unlikely((ia->ia_size == i_size))) {
747 lower_ia->ia_valid &= ~ATTR_SIZE;
748 return 0;
749 }
750 rc = ecryptfs_get_lower_file(dentry, inode);
751 if (rc)
752 return rc;
753 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
754 /* Switch on growing or shrinking file */
755 if (ia->ia_size > i_size) {
756 char zero[] = { 0x00 };
757
758 lower_ia->ia_valid &= ~ATTR_SIZE;
759 /* Write a single 0 at the last position of the file;
760 * this triggers code that will fill in 0's throughout
761 * the intermediate portion of the previous end of the
762 * file and the new and of the file */
763 rc = ecryptfs_write(inode, zero,
764 (ia->ia_size - 1), 1);
765 } else { /* ia->ia_size < i_size_read(inode) */
766 /* We're chopping off all the pages down to the page
767 * in which ia->ia_size is located. Fill in the end of
768 * that page from (ia->ia_size & ~PAGE_MASK) to
769 * PAGE_SIZE with zeros. */
770 size_t num_zeros = (PAGE_SIZE
771 - (ia->ia_size & ~PAGE_MASK));
772
773 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
774 truncate_setsize(inode, ia->ia_size);
775 lower_ia->ia_size = ia->ia_size;
776 lower_ia->ia_valid |= ATTR_SIZE;
777 goto out;
778 }
779 if (num_zeros) {
780 char *zeros_virt;
781
782 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
783 if (!zeros_virt) {
784 rc = -ENOMEM;
785 goto out;
786 }
787 rc = ecryptfs_write(inode, zeros_virt,
788 ia->ia_size, num_zeros);
789 kfree(zeros_virt);
790 if (rc) {
791 printk(KERN_ERR "Error attempting to zero out "
792 "the remainder of the end page on "
793 "reducing truncate; rc = [%d]\n", rc);
794 goto out;
795 }
796 }
797 truncate_setsize(inode, ia->ia_size);
798 rc = ecryptfs_write_inode_size_to_metadata(inode);
799 if (rc) {
800 printk(KERN_ERR "Problem with "
801 "ecryptfs_write_inode_size_to_metadata; "
802 "rc = [%d]\n", rc);
803 goto out;
804 }
805 /* We are reducing the size of the ecryptfs file, and need to
806 * know if we need to reduce the size of the lower file. */
807 lower_size_before_truncate =
808 upper_size_to_lower_size(crypt_stat, i_size);
809 lower_size_after_truncate =
810 upper_size_to_lower_size(crypt_stat, ia->ia_size);
811 if (lower_size_after_truncate < lower_size_before_truncate) {
812 lower_ia->ia_size = lower_size_after_truncate;
813 lower_ia->ia_valid |= ATTR_SIZE;
814 } else
815 lower_ia->ia_valid &= ~ATTR_SIZE;
816 }
817out:
818 ecryptfs_put_lower_file(inode);
819 return rc;
820}
821
822static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
823{
824 struct ecryptfs_crypt_stat *crypt_stat;
825 loff_t lower_oldsize, lower_newsize;
826
827 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
828 lower_oldsize = upper_size_to_lower_size(crypt_stat,
829 i_size_read(inode));
830 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
831 if (lower_newsize > lower_oldsize) {
832 /*
833 * The eCryptfs inode and the new *lower* size are mixed here
834 * because we may not have the lower i_mutex held and/or it may
835 * not be appropriate to call inode_newsize_ok() with inodes
836 * from other filesystems.
837 */
838 return inode_newsize_ok(inode, lower_newsize);
839 }
840
841 return 0;
842}
843
844/**
845 * ecryptfs_truncate
846 * @dentry: The ecryptfs layer dentry
847 * @new_length: The length to expand the file to
848 *
849 * Simple function that handles the truncation of an eCryptfs inode and
850 * its corresponding lower inode.
851 *
852 * Returns zero on success; non-zero otherwise
853 */
854int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
855{
856 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
857 struct iattr lower_ia = { .ia_valid = 0 };
858 int rc;
859
860 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
861 if (rc)
862 return rc;
863
864 rc = truncate_upper(dentry, &ia, &lower_ia);
865 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
866 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
867
868 inode_lock(d_inode(lower_dentry));
869 rc = notify_change(&nop_mnt_idmap, lower_dentry,
870 &lower_ia, NULL);
871 inode_unlock(d_inode(lower_dentry));
872 }
873 return rc;
874}
875
876static int
877ecryptfs_permission(struct mnt_idmap *idmap, struct inode *inode,
878 int mask)
879{
880 return inode_permission(&nop_mnt_idmap,
881 ecryptfs_inode_to_lower(inode), mask);
882}
883
884/**
885 * ecryptfs_setattr
886 * @idmap: idmap of the target mount
887 * @dentry: dentry handle to the inode to modify
888 * @ia: Structure with flags of what to change and values
889 *
890 * Updates the metadata of an inode. If the update is to the size
891 * i.e. truncation, then ecryptfs_truncate will handle the size modification
892 * of both the ecryptfs inode and the lower inode.
893 *
894 * All other metadata changes will be passed right to the lower filesystem,
895 * and we will just update our inode to look like the lower.
896 */
897static int ecryptfs_setattr(struct mnt_idmap *idmap,
898 struct dentry *dentry, struct iattr *ia)
899{
900 int rc = 0;
901 struct dentry *lower_dentry;
902 struct iattr lower_ia;
903 struct inode *inode;
904 struct inode *lower_inode;
905 struct ecryptfs_crypt_stat *crypt_stat;
906
907 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
908 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
909 rc = ecryptfs_init_crypt_stat(crypt_stat);
910 if (rc)
911 return rc;
912 }
913 inode = d_inode(dentry);
914 lower_inode = ecryptfs_inode_to_lower(inode);
915 lower_dentry = ecryptfs_dentry_to_lower(dentry);
916 mutex_lock(&crypt_stat->cs_mutex);
917 if (d_is_dir(dentry))
918 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
919 else if (d_is_reg(dentry)
920 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
921 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
922 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
923
924 mount_crypt_stat = &ecryptfs_superblock_to_private(
925 dentry->d_sb)->mount_crypt_stat;
926 rc = ecryptfs_get_lower_file(dentry, inode);
927 if (rc) {
928 mutex_unlock(&crypt_stat->cs_mutex);
929 goto out;
930 }
931 rc = ecryptfs_read_metadata(dentry);
932 ecryptfs_put_lower_file(inode);
933 if (rc) {
934 if (!(mount_crypt_stat->flags
935 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
936 rc = -EIO;
937 printk(KERN_WARNING "Either the lower file "
938 "is not in a valid eCryptfs format, "
939 "or the key could not be retrieved. "
940 "Plaintext passthrough mode is not "
941 "enabled; returning -EIO\n");
942 mutex_unlock(&crypt_stat->cs_mutex);
943 goto out;
944 }
945 rc = 0;
946 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
947 | ECRYPTFS_ENCRYPTED);
948 }
949 }
950 mutex_unlock(&crypt_stat->cs_mutex);
951
952 rc = setattr_prepare(&nop_mnt_idmap, dentry, ia);
953 if (rc)
954 goto out;
955 if (ia->ia_valid & ATTR_SIZE) {
956 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
957 if (rc)
958 goto out;
959 }
960
961 memcpy(&lower_ia, ia, sizeof(lower_ia));
962 if (ia->ia_valid & ATTR_FILE)
963 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
964 if (ia->ia_valid & ATTR_SIZE) {
965 rc = truncate_upper(dentry, ia, &lower_ia);
966 if (rc < 0)
967 goto out;
968 }
969
970 /*
971 * mode change is for clearing setuid/setgid bits. Allow lower fs
972 * to interpret this in its own way.
973 */
974 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
975 lower_ia.ia_valid &= ~ATTR_MODE;
976
977 inode_lock(d_inode(lower_dentry));
978 rc = notify_change(&nop_mnt_idmap, lower_dentry, &lower_ia, NULL);
979 inode_unlock(d_inode(lower_dentry));
980out:
981 fsstack_copy_attr_all(inode, lower_inode);
982 return rc;
983}
984
985static int ecryptfs_getattr_link(struct mnt_idmap *idmap,
986 const struct path *path, struct kstat *stat,
987 u32 request_mask, unsigned int flags)
988{
989 struct dentry *dentry = path->dentry;
990 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
991 int rc = 0;
992
993 mount_crypt_stat = &ecryptfs_superblock_to_private(
994 dentry->d_sb)->mount_crypt_stat;
995 generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
996 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
997 char *target;
998 size_t targetsiz;
999
1000 target = ecryptfs_readlink_lower(dentry, &targetsiz);
1001 if (!IS_ERR(target)) {
1002 kfree(target);
1003 stat->size = targetsiz;
1004 } else {
1005 rc = PTR_ERR(target);
1006 }
1007 }
1008 return rc;
1009}
1010
1011static int ecryptfs_getattr(struct mnt_idmap *idmap,
1012 const struct path *path, struct kstat *stat,
1013 u32 request_mask, unsigned int flags)
1014{
1015 struct dentry *dentry = path->dentry;
1016 struct kstat lower_stat;
1017 int rc;
1018
1019 rc = vfs_getattr_nosec(ecryptfs_dentry_to_lower_path(dentry),
1020 &lower_stat, request_mask, flags);
1021 if (!rc) {
1022 fsstack_copy_attr_all(d_inode(dentry),
1023 ecryptfs_inode_to_lower(d_inode(dentry)));
1024 generic_fillattr(&nop_mnt_idmap, request_mask,
1025 d_inode(dentry), stat);
1026 stat->blocks = lower_stat.blocks;
1027 }
1028 return rc;
1029}
1030
1031int
1032ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
1033 const char *name, const void *value,
1034 size_t size, int flags)
1035{
1036 int rc;
1037 struct dentry *lower_dentry;
1038 struct inode *lower_inode;
1039
1040 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1041 lower_inode = d_inode(lower_dentry);
1042 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1043 rc = -EOPNOTSUPP;
1044 goto out;
1045 }
1046 inode_lock(lower_inode);
1047 rc = __vfs_setxattr_locked(&nop_mnt_idmap, lower_dentry, name, value, size, flags, NULL);
1048 inode_unlock(lower_inode);
1049 if (!rc && inode)
1050 fsstack_copy_attr_all(inode, lower_inode);
1051out:
1052 return rc;
1053}
1054
1055ssize_t
1056ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
1057 const char *name, void *value, size_t size)
1058{
1059 int rc;
1060
1061 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1062 rc = -EOPNOTSUPP;
1063 goto out;
1064 }
1065 inode_lock(lower_inode);
1066 rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
1067 inode_unlock(lower_inode);
1068out:
1069 return rc;
1070}
1071
1072static ssize_t
1073ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
1074 const char *name, void *value, size_t size)
1075{
1076 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
1077 ecryptfs_inode_to_lower(inode),
1078 name, value, size);
1079}
1080
1081static ssize_t
1082ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1083{
1084 int rc = 0;
1085 struct dentry *lower_dentry;
1086
1087 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1088 if (!d_inode(lower_dentry)->i_op->listxattr) {
1089 rc = -EOPNOTSUPP;
1090 goto out;
1091 }
1092 inode_lock(d_inode(lower_dentry));
1093 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1094 inode_unlock(d_inode(lower_dentry));
1095out:
1096 return rc;
1097}
1098
1099static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
1100 const char *name)
1101{
1102 int rc;
1103 struct dentry *lower_dentry;
1104 struct inode *lower_inode;
1105
1106 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1107 lower_inode = ecryptfs_inode_to_lower(inode);
1108 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1109 rc = -EOPNOTSUPP;
1110 goto out;
1111 }
1112 inode_lock(lower_inode);
1113 rc = __vfs_removexattr(&nop_mnt_idmap, lower_dentry, name);
1114 inode_unlock(lower_inode);
1115out:
1116 return rc;
1117}
1118
1119static int ecryptfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
1120{
1121 return vfs_fileattr_get(ecryptfs_dentry_to_lower(dentry), fa);
1122}
1123
1124static int ecryptfs_fileattr_set(struct mnt_idmap *idmap,
1125 struct dentry *dentry, struct fileattr *fa)
1126{
1127 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
1128 int rc;
1129
1130 rc = vfs_fileattr_set(&nop_mnt_idmap, lower_dentry, fa);
1131 fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
1132
1133 return rc;
1134}
1135
1136static struct posix_acl *ecryptfs_get_acl(struct mnt_idmap *idmap,
1137 struct dentry *dentry, int type)
1138{
1139 return vfs_get_acl(idmap, ecryptfs_dentry_to_lower(dentry),
1140 posix_acl_xattr_name(type));
1141}
1142
1143static int ecryptfs_set_acl(struct mnt_idmap *idmap,
1144 struct dentry *dentry, struct posix_acl *acl,
1145 int type)
1146{
1147 int rc;
1148 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
1149 struct inode *lower_inode = d_inode(lower_dentry);
1150
1151 rc = vfs_set_acl(&nop_mnt_idmap, lower_dentry,
1152 posix_acl_xattr_name(type), acl);
1153 if (!rc)
1154 fsstack_copy_attr_all(d_inode(dentry), lower_inode);
1155 return rc;
1156}
1157
1158const struct inode_operations ecryptfs_symlink_iops = {
1159 .get_link = ecryptfs_get_link,
1160 .permission = ecryptfs_permission,
1161 .setattr = ecryptfs_setattr,
1162 .getattr = ecryptfs_getattr_link,
1163 .listxattr = ecryptfs_listxattr,
1164};
1165
1166const struct inode_operations ecryptfs_dir_iops = {
1167 .create = ecryptfs_create,
1168 .lookup = ecryptfs_lookup,
1169 .link = ecryptfs_link,
1170 .unlink = ecryptfs_unlink,
1171 .symlink = ecryptfs_symlink,
1172 .mkdir = ecryptfs_mkdir,
1173 .rmdir = ecryptfs_rmdir,
1174 .mknod = ecryptfs_mknod,
1175 .rename = ecryptfs_rename,
1176 .permission = ecryptfs_permission,
1177 .setattr = ecryptfs_setattr,
1178 .listxattr = ecryptfs_listxattr,
1179 .fileattr_get = ecryptfs_fileattr_get,
1180 .fileattr_set = ecryptfs_fileattr_set,
1181 .get_acl = ecryptfs_get_acl,
1182 .set_acl = ecryptfs_set_acl,
1183};
1184
1185const struct inode_operations ecryptfs_main_iops = {
1186 .permission = ecryptfs_permission,
1187 .setattr = ecryptfs_setattr,
1188 .getattr = ecryptfs_getattr,
1189 .listxattr = ecryptfs_listxattr,
1190 .fileattr_get = ecryptfs_fileattr_get,
1191 .fileattr_set = ecryptfs_fileattr_set,
1192 .get_acl = ecryptfs_get_acl,
1193 .set_acl = ecryptfs_set_acl,
1194};
1195
1196static int ecryptfs_xattr_get(const struct xattr_handler *handler,
1197 struct dentry *dentry, struct inode *inode,
1198 const char *name, void *buffer, size_t size)
1199{
1200 return ecryptfs_getxattr(dentry, inode, name, buffer, size);
1201}
1202
1203static int ecryptfs_xattr_set(const struct xattr_handler *handler,
1204 struct mnt_idmap *idmap,
1205 struct dentry *dentry, struct inode *inode,
1206 const char *name, const void *value, size_t size,
1207 int flags)
1208{
1209 if (value)
1210 return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
1211 else {
1212 BUG_ON(flags != XATTR_REPLACE);
1213 return ecryptfs_removexattr(dentry, inode, name);
1214 }
1215}
1216
1217static const struct xattr_handler ecryptfs_xattr_handler = {
1218 .prefix = "", /* match anything */
1219 .get = ecryptfs_xattr_get,
1220 .set = ecryptfs_xattr_set,
1221};
1222
1223const struct xattr_handler * const ecryptfs_xattr_handlers[] = {
1224 &ecryptfs_xattr_handler,
1225 NULL
1226};