1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
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/crypto.h>
33#include <linux/fs_stack.h>
34#include <asm/unaligned.h>
35#include "ecryptfs_kernel.h"
36
37static struct dentry *lock_parent(struct dentry *dentry)
38{
39 struct dentry *dir;
40
41 dir = dget_parent(dentry);
42 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
43 return dir;
44}
45
46static void unlock_dir(struct dentry *dir)
47{
48 mutex_unlock(&dir->d_inode->i_mutex);
49 dput(dir);
50}
51
52
53
54
55
56
57
58
59
60
61
62
63static int
64ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
65 struct dentry *dentry, int mode,
66 struct nameidata *nd)
67{
68 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
69 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
70 struct dentry *dentry_save;
71 struct vfsmount *vfsmount_save;
72 int rc;
73
74 dentry_save = nd->path.dentry;
75 vfsmount_save = nd->path.mnt;
76 nd->path.dentry = lower_dentry;
77 nd->path.mnt = lower_mnt;
78 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
79 nd->path.dentry = dentry_save;
80 nd->path.mnt = vfsmount_save;
81 return rc;
82}
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97static int
98ecryptfs_do_create(struct inode *directory_inode,
99 struct dentry *ecryptfs_dentry, int mode,
100 struct nameidata *nd)
101{
102 int rc;
103 struct dentry *lower_dentry;
104 struct dentry *lower_dir_dentry;
105
106 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
107 lower_dir_dentry = lock_parent(lower_dentry);
108 if (IS_ERR(lower_dir_dentry)) {
109 ecryptfs_printk(KERN_ERR, "Error locking directory of "
110 "dentry\n");
111 rc = PTR_ERR(lower_dir_dentry);
112 goto out;
113 }
114 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
115 ecryptfs_dentry, mode, nd);
116 if (rc) {
117 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
118 "rc = [%d]\n", __func__, rc);
119 goto out_lock;
120 }
121 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
122 directory_inode->i_sb, 0);
123 if (rc) {
124 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
125 goto out_lock;
126 }
127 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
128 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
129out_lock:
130 unlock_dir(lower_dir_dentry);
131out:
132 return rc;
133}
134
135
136
137
138
139
140
141static int grow_file(struct dentry *ecryptfs_dentry)
142{
143 struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
144 struct file fake_file;
145 struct ecryptfs_file_info tmp_file_info;
146 char zero_virt[] = { 0x00 };
147 int rc = 0;
148
149 memset(&fake_file, 0, sizeof(fake_file));
150 fake_file.f_path.dentry = ecryptfs_dentry;
151 memset(&tmp_file_info, 0, sizeof(tmp_file_info));
152 ecryptfs_set_file_private(&fake_file, &tmp_file_info);
153 ecryptfs_set_file_lower(
154 &fake_file,
155 ecryptfs_inode_to_private(ecryptfs_inode)->lower_file);
156 rc = ecryptfs_write(&fake_file, zero_virt, 0, 1);
157 i_size_write(ecryptfs_inode, 0);
158 rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
159 ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
160 ECRYPTFS_NEW_FILE;
161 return rc;
162}
163
164
165
166
167
168
169
170
171
172static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
173{
174 struct ecryptfs_crypt_stat *crypt_stat =
175 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
176 int rc = 0;
177
178 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
179 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
180 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
181 goto out;
182 }
183 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
184 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
185 rc = ecryptfs_new_file_context(ecryptfs_dentry);
186 if (rc) {
187 ecryptfs_printk(KERN_ERR, "Error creating new file "
188 "context; rc = [%d]\n", rc);
189 goto out;
190 }
191 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
192 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
193 if (rc) {
194 printk(KERN_ERR "%s: Error attempting to initialize "
195 "the persistent file for the dentry with name "
196 "[%s]; rc = [%d]\n", __func__,
197 ecryptfs_dentry->d_name.name, rc);
198 goto out;
199 }
200 }
201 rc = ecryptfs_write_metadata(ecryptfs_dentry);
202 if (rc) {
203 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
204 goto out;
205 }
206 rc = grow_file(ecryptfs_dentry);
207 if (rc)
208 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
209out:
210 return rc;
211}
212
213
214
215
216
217
218
219
220
221
222
223
224static int
225ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
226 int mode, struct nameidata *nd)
227{
228 int rc;
229
230
231 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
232 if (unlikely(rc)) {
233 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
234 "lower filesystem\n");
235 goto out;
236 }
237
238
239 rc = ecryptfs_initialize_file(ecryptfs_dentry);
240out:
241 return rc;
242}
243
244
245
246
247int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
248 struct dentry *lower_dentry,
249 struct inode *ecryptfs_dir_inode,
250 struct nameidata *ecryptfs_nd)
251{
252 struct dentry *lower_dir_dentry;
253 struct vfsmount *lower_mnt;
254 struct inode *lower_inode;
255 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
256 struct ecryptfs_crypt_stat *crypt_stat;
257 char *page_virt = NULL;
258 u64 file_size;
259 int rc = 0;
260
261 lower_dir_dentry = lower_dentry->d_parent;
262 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
263 ecryptfs_dentry->d_parent));
264 lower_inode = lower_dentry->d_inode;
265 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
266 BUG_ON(!atomic_read(&lower_dentry->d_count));
267 ecryptfs_set_dentry_private(ecryptfs_dentry,
268 kmem_cache_alloc(ecryptfs_dentry_info_cache,
269 GFP_KERNEL));
270 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
271 rc = -ENOMEM;
272 printk(KERN_ERR "%s: Out of memory whilst attempting "
273 "to allocate ecryptfs_dentry_info struct\n",
274 __func__);
275 goto out_dput;
276 }
277 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
278 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
279 if (!lower_dentry->d_inode) {
280
281 d_add(ecryptfs_dentry, NULL);
282 goto out;
283 }
284 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
285 ecryptfs_dir_inode->i_sb, 1);
286 if (rc) {
287 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
288 __func__, rc);
289 goto out;
290 }
291 if (S_ISDIR(lower_inode->i_mode))
292 goto out;
293 if (S_ISLNK(lower_inode->i_mode))
294 goto out;
295 if (special_file(lower_inode->i_mode))
296 goto out;
297 if (!ecryptfs_nd)
298 goto out;
299
300 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
301 if (!page_virt) {
302 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
303 __func__);
304 rc = -ENOMEM;
305 goto out;
306 }
307 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
308 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
309 if (rc) {
310 printk(KERN_ERR "%s: Error attempting to initialize "
311 "the persistent file for the dentry with name "
312 "[%s]; rc = [%d]\n", __func__,
313 ecryptfs_dentry->d_name.name, rc);
314 goto out_free_kmem;
315 }
316 }
317 crypt_stat = &ecryptfs_inode_to_private(
318 ecryptfs_dentry->d_inode)->crypt_stat;
319
320 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
321 ecryptfs_set_default_sizes(crypt_stat);
322 rc = ecryptfs_read_and_validate_header_region(page_virt,
323 ecryptfs_dentry->d_inode);
324 if (rc) {
325 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
326 ecryptfs_dentry);
327 if (rc) {
328 rc = 0;
329 goto out_free_kmem;
330 }
331 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
332 }
333 mount_crypt_stat = &ecryptfs_superblock_to_private(
334 ecryptfs_dentry->d_sb)->mount_crypt_stat;
335 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
336 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
337 file_size = (crypt_stat->num_header_bytes_at_front
338 + i_size_read(lower_dentry->d_inode));
339 else
340 file_size = i_size_read(lower_dentry->d_inode);
341 } else {
342 file_size = get_unaligned_be64(page_virt);
343 }
344 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
345out_free_kmem:
346 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
347 goto out;
348out_dput:
349 dput(lower_dentry);
350 d_drop(ecryptfs_dentry);
351out:
352 return rc;
353}
354
355
356
357
358
359
360
361
362
363
364static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
365 struct dentry *ecryptfs_dentry,
366 struct nameidata *ecryptfs_nd)
367{
368 char *encrypted_and_encoded_name = NULL;
369 size_t encrypted_and_encoded_name_size;
370 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
371 struct dentry *lower_dir_dentry, *lower_dentry;
372 int rc = 0;
373
374 ecryptfs_dentry->d_op = &ecryptfs_dops;
375 if ((ecryptfs_dentry->d_name.len == 1
376 && !strcmp(ecryptfs_dentry->d_name.name, "."))
377 || (ecryptfs_dentry->d_name.len == 2
378 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
379 goto out_d_drop;
380 }
381 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
382 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
383 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
384 lower_dir_dentry,
385 ecryptfs_dentry->d_name.len);
386 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
387 if (IS_ERR(lower_dentry)) {
388 rc = PTR_ERR(lower_dentry);
389 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
390 "lower_dentry = [%s]\n", __func__, rc,
391 ecryptfs_dentry->d_name.name);
392 goto out_d_drop;
393 }
394 if (lower_dentry->d_inode)
395 goto lookup_and_interpose;
396 mount_crypt_stat = &ecryptfs_superblock_to_private(
397 ecryptfs_dentry->d_sb)->mount_crypt_stat;
398 if (!(mount_crypt_stat
399 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
400 goto lookup_and_interpose;
401 dput(lower_dentry);
402 rc = ecryptfs_encrypt_and_encode_filename(
403 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
404 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
405 ecryptfs_dentry->d_name.len);
406 if (rc) {
407 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
408 "filename; rc = [%d]\n", __func__, rc);
409 goto out_d_drop;
410 }
411 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
412 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
413 lower_dir_dentry,
414 encrypted_and_encoded_name_size - 1);
415 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
416 if (IS_ERR(lower_dentry)) {
417 rc = PTR_ERR(lower_dentry);
418 printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
419 "lower_dentry = [%s]\n", __func__, rc,
420 encrypted_and_encoded_name);
421 goto out_d_drop;
422 }
423lookup_and_interpose:
424 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
425 ecryptfs_dir_inode,
426 ecryptfs_nd);
427 goto out;
428out_d_drop:
429 d_drop(ecryptfs_dentry);
430out:
431 kfree(encrypted_and_encoded_name);
432 return ERR_PTR(rc);
433}
434
435static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
436 struct dentry *new_dentry)
437{
438 struct dentry *lower_old_dentry;
439 struct dentry *lower_new_dentry;
440 struct dentry *lower_dir_dentry;
441 u64 file_size_save;
442 int rc;
443
444 file_size_save = i_size_read(old_dentry->d_inode);
445 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
446 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
447 dget(lower_old_dentry);
448 dget(lower_new_dentry);
449 lower_dir_dentry = lock_parent(lower_new_dentry);
450 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
451 lower_new_dentry);
452 if (rc || !lower_new_dentry->d_inode)
453 goto out_lock;
454 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
455 if (rc)
456 goto out_lock;
457 fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
458 fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
459 old_dentry->d_inode->i_nlink =
460 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
461 i_size_write(new_dentry->d_inode, file_size_save);
462out_lock:
463 unlock_dir(lower_dir_dentry);
464 dput(lower_new_dentry);
465 dput(lower_old_dentry);
466 d_drop(lower_old_dentry);
467 d_drop(new_dentry);
468 d_drop(old_dentry);
469 return rc;
470}
471
472static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
473{
474 int rc = 0;
475 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
476 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
477 struct dentry *lower_dir_dentry;
478
479 dget(lower_dentry);
480 lower_dir_dentry = lock_parent(lower_dentry);
481 rc = vfs_unlink(lower_dir_inode, lower_dentry);
482 if (rc) {
483 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
484 goto out_unlock;
485 }
486 fsstack_copy_attr_times(dir, lower_dir_inode);
487 dentry->d_inode->i_nlink =
488 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
489 dentry->d_inode->i_ctime = dir->i_ctime;
490 d_drop(dentry);
491out_unlock:
492 unlock_dir(lower_dir_dentry);
493 dput(lower_dentry);
494 return rc;
495}
496
497static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
498 const char *symname)
499{
500 int rc;
501 struct dentry *lower_dentry;
502 struct dentry *lower_dir_dentry;
503 char *encoded_symname;
504 size_t encoded_symlen;
505 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
506
507 lower_dentry = ecryptfs_dentry_to_lower(dentry);
508 dget(lower_dentry);
509 lower_dir_dentry = lock_parent(lower_dentry);
510 mount_crypt_stat = &ecryptfs_superblock_to_private(
511 dir->i_sb)->mount_crypt_stat;
512 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
513 &encoded_symlen,
514 NULL,
515 mount_crypt_stat, symname,
516 strlen(symname));
517 if (rc)
518 goto out_lock;
519 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
520 encoded_symname);
521 kfree(encoded_symname);
522 if (rc || !lower_dentry->d_inode)
523 goto out_lock;
524 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
525 if (rc)
526 goto out_lock;
527 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
528 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
529out_lock:
530 unlock_dir(lower_dir_dentry);
531 dput(lower_dentry);
532 if (!dentry->d_inode)
533 d_drop(dentry);
534 return rc;
535}
536
537static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
538{
539 int rc;
540 struct dentry *lower_dentry;
541 struct dentry *lower_dir_dentry;
542
543 lower_dentry = ecryptfs_dentry_to_lower(dentry);
544 lower_dir_dentry = lock_parent(lower_dentry);
545 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
546 if (rc || !lower_dentry->d_inode)
547 goto out;
548 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
549 if (rc)
550 goto out;
551 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
552 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
553 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
554out:
555 unlock_dir(lower_dir_dentry);
556 if (!dentry->d_inode)
557 d_drop(dentry);
558 return rc;
559}
560
561static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
562{
563 struct dentry *lower_dentry;
564 struct dentry *lower_dir_dentry;
565 int rc;
566
567 lower_dentry = ecryptfs_dentry_to_lower(dentry);
568 dget(dentry);
569 lower_dir_dentry = lock_parent(lower_dentry);
570 dget(lower_dentry);
571 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
572 dput(lower_dentry);
573 if (!rc)
574 d_delete(lower_dentry);
575 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
576 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
577 unlock_dir(lower_dir_dentry);
578 if (!rc)
579 d_drop(dentry);
580 dput(dentry);
581 return rc;
582}
583
584static int
585ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
586{
587 int rc;
588 struct dentry *lower_dentry;
589 struct dentry *lower_dir_dentry;
590
591 lower_dentry = ecryptfs_dentry_to_lower(dentry);
592 lower_dir_dentry = lock_parent(lower_dentry);
593 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
594 if (rc || !lower_dentry->d_inode)
595 goto out;
596 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
597 if (rc)
598 goto out;
599 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
600 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
601out:
602 unlock_dir(lower_dir_dentry);
603 if (!dentry->d_inode)
604 d_drop(dentry);
605 return rc;
606}
607
608static int
609ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
610 struct inode *new_dir, struct dentry *new_dentry)
611{
612 int rc;
613 struct dentry *lower_old_dentry;
614 struct dentry *lower_new_dentry;
615 struct dentry *lower_old_dir_dentry;
616 struct dentry *lower_new_dir_dentry;
617
618 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
619 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
620 dget(lower_old_dentry);
621 dget(lower_new_dentry);
622 lower_old_dir_dentry = dget_parent(lower_old_dentry);
623 lower_new_dir_dentry = dget_parent(lower_new_dentry);
624 lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
625 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
626 lower_new_dir_dentry->d_inode, lower_new_dentry);
627 if (rc)
628 goto out_lock;
629 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL);
630 if (new_dir != old_dir)
631 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL);
632out_lock:
633 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
634 dput(lower_new_dentry->d_parent);
635 dput(lower_old_dentry->d_parent);
636 dput(lower_new_dentry);
637 dput(lower_old_dentry);
638 return rc;
639}
640
641static int
642ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
643{
644 char *lower_buf;
645 size_t lower_bufsiz;
646 struct dentry *lower_dentry;
647 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
648 char *plaintext_name;
649 size_t plaintext_name_size;
650 mm_segment_t old_fs;
651 int rc;
652
653 lower_dentry = ecryptfs_dentry_to_lower(dentry);
654 if (!lower_dentry->d_inode->i_op->readlink) {
655 rc = -EINVAL;
656 goto out;
657 }
658 mount_crypt_stat = &ecryptfs_superblock_to_private(
659 dentry->d_sb)->mount_crypt_stat;
660
661
662
663
664 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
665 lower_bufsiz = PATH_MAX;
666 else
667 lower_bufsiz = bufsiz;
668
669 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
670 if (lower_buf == NULL) {
671 printk(KERN_ERR "%s: Out of memory whilst attempting to "
672 "kmalloc [%zd] bytes\n", __func__, lower_bufsiz);
673 rc = -ENOMEM;
674 goto out;
675 }
676 old_fs = get_fs();
677 set_fs(get_ds());
678 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
679 (char __user *)lower_buf,
680 lower_bufsiz);
681 set_fs(old_fs);
682 if (rc >= 0) {
683 rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
684 &plaintext_name_size,
685 dentry, lower_buf,
686 rc);
687 if (rc) {
688 printk(KERN_ERR "%s: Error attempting to decode and "
689 "decrypt filename; rc = [%d]\n", __func__,
690 rc);
691 goto out_free_lower_buf;
692 }
693
694 rc = copy_to_user(buf, plaintext_name,
695 min((size_t) bufsiz, plaintext_name_size));
696 if (rc)
697 rc = -EFAULT;
698 else
699 rc = plaintext_name_size;
700 kfree(plaintext_name);
701 fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
702 }
703out_free_lower_buf:
704 kfree(lower_buf);
705out:
706 return rc;
707}
708
709static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
710{
711 char *buf;
712 int len = PAGE_SIZE, rc;
713 mm_segment_t old_fs;
714
715
716 buf = kmalloc(len, GFP_KERNEL);
717 if (!buf) {
718 rc = -ENOMEM;
719 goto out;
720 }
721 old_fs = get_fs();
722 set_fs(get_ds());
723 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
724 set_fs(old_fs);
725 if (rc < 0)
726 goto out_free;
727 else
728 buf[rc] = '\0';
729 rc = 0;
730 nd_set_link(nd, buf);
731 goto out;
732out_free:
733 kfree(buf);
734out:
735 return ERR_PTR(rc);
736}
737
738static void
739ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
740{
741
742 kfree(nd_get_link(nd));
743}
744
745
746
747
748
749
750
751
752
753
754
755
756static loff_t
757upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
758 loff_t upper_size)
759{
760 loff_t lower_size;
761
762 lower_size = crypt_stat->num_header_bytes_at_front;
763 if (upper_size != 0) {
764 loff_t num_extents;
765
766 num_extents = upper_size >> crypt_stat->extent_shift;
767 if (upper_size & ~crypt_stat->extent_mask)
768 num_extents++;
769 lower_size += (num_extents * crypt_stat->extent_size);
770 }
771 return lower_size;
772}
773
774
775
776
777
778
779
780
781
782
783
784
785
786int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
787{
788 int rc = 0;
789 struct inode *inode = dentry->d_inode;
790 struct dentry *lower_dentry;
791 struct file fake_ecryptfs_file;
792 struct ecryptfs_crypt_stat *crypt_stat;
793 loff_t i_size = i_size_read(inode);
794 loff_t lower_size_before_truncate;
795 loff_t lower_size_after_truncate;
796
797 if (unlikely((new_length == i_size)))
798 goto out;
799 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
800
801
802
803 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
804 fake_ecryptfs_file.f_path.dentry = dentry;
805
806 ecryptfs_set_file_private(&fake_ecryptfs_file,
807 kmem_cache_alloc(ecryptfs_file_info_cache,
808 GFP_KERNEL));
809 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
810 rc = -ENOMEM;
811 goto out;
812 }
813 lower_dentry = ecryptfs_dentry_to_lower(dentry);
814 ecryptfs_set_file_lower(
815 &fake_ecryptfs_file,
816 ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
817
818 if (new_length > i_size) {
819 char zero[] = { 0x00 };
820
821
822
823
824
825 rc = ecryptfs_write(&fake_ecryptfs_file, zero,
826 (new_length - 1), 1);
827 } else {
828
829
830
831
832 size_t num_zeros = (PAGE_CACHE_SIZE
833 - (new_length & ~PAGE_CACHE_MASK));
834
835 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
836 rc = vmtruncate(inode, new_length);
837 if (rc)
838 goto out_free;
839 rc = vmtruncate(lower_dentry->d_inode, new_length);
840 goto out_free;
841 }
842 if (num_zeros) {
843 char *zeros_virt;
844
845 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
846 if (!zeros_virt) {
847 rc = -ENOMEM;
848 goto out_free;
849 }
850 rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
851 new_length, num_zeros);
852 kfree(zeros_virt);
853 if (rc) {
854 printk(KERN_ERR "Error attempting to zero out "
855 "the remainder of the end page on "
856 "reducing truncate; rc = [%d]\n", rc);
857 goto out_free;
858 }
859 }
860 vmtruncate(inode, new_length);
861 rc = ecryptfs_write_inode_size_to_metadata(inode);
862 if (rc) {
863 printk(KERN_ERR "Problem with "
864 "ecryptfs_write_inode_size_to_metadata; "
865 "rc = [%d]\n", rc);
866 goto out_free;
867 }
868
869
870 lower_size_before_truncate =
871 upper_size_to_lower_size(crypt_stat, i_size);
872 lower_size_after_truncate =
873 upper_size_to_lower_size(crypt_stat, new_length);
874 if (lower_size_after_truncate < lower_size_before_truncate)
875 vmtruncate(lower_dentry->d_inode,
876 lower_size_after_truncate);
877 }
878out_free:
879 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
880 kmem_cache_free(ecryptfs_file_info_cache,
881 ecryptfs_file_to_private(&fake_ecryptfs_file));
882out:
883 return rc;
884}
885
886static int
887ecryptfs_permission(struct inode *inode, int mask)
888{
889 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
890}
891
892
893
894
895
896
897
898
899
900
901
902
903
904static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
905{
906 int rc = 0;
907 struct dentry *lower_dentry;
908 struct inode *inode;
909 struct inode *lower_inode;
910 struct ecryptfs_crypt_stat *crypt_stat;
911
912 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
913 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
914 ecryptfs_init_crypt_stat(crypt_stat);
915 inode = dentry->d_inode;
916 lower_inode = ecryptfs_inode_to_lower(inode);
917 lower_dentry = ecryptfs_dentry_to_lower(dentry);
918 mutex_lock(&crypt_stat->cs_mutex);
919 if (S_ISDIR(dentry->d_inode->i_mode))
920 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
921 else if (S_ISREG(dentry->d_inode->i_mode)
922 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
923 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
924 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
925
926 mount_crypt_stat = &ecryptfs_superblock_to_private(
927 dentry->d_sb)->mount_crypt_stat;
928 rc = ecryptfs_read_metadata(dentry);
929 if (rc) {
930 if (!(mount_crypt_stat->flags
931 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
932 rc = -EIO;
933 printk(KERN_WARNING "Either the lower file "
934 "is not in a valid eCryptfs format, "
935 "or the key could not be retrieved. "
936 "Plaintext passthrough mode is not "
937 "enabled; returning -EIO\n");
938 mutex_unlock(&crypt_stat->cs_mutex);
939 goto out;
940 }
941 rc = 0;
942 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
943 }
944 }
945 mutex_unlock(&crypt_stat->cs_mutex);
946 if (ia->ia_valid & ATTR_SIZE) {
947 ecryptfs_printk(KERN_DEBUG,
948 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
949 ia->ia_valid, ATTR_SIZE);
950 rc = ecryptfs_truncate(dentry, ia->ia_size);
951
952 ia->ia_valid &= ~ATTR_SIZE;
953 ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
954 ia->ia_valid);
955 if (rc < 0)
956 goto out;
957 }
958
959
960
961
962
963 if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
964 ia->ia_valid &= ~ATTR_MODE;
965
966 mutex_lock(&lower_dentry->d_inode->i_mutex);
967 rc = notify_change(lower_dentry, ia);
968 mutex_unlock(&lower_dentry->d_inode->i_mutex);
969out:
970 fsstack_copy_attr_all(inode, lower_inode, NULL);
971 return rc;
972}
973
974int
975ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
976 size_t size, int flags)
977{
978 int rc = 0;
979 struct dentry *lower_dentry;
980
981 lower_dentry = ecryptfs_dentry_to_lower(dentry);
982 if (!lower_dentry->d_inode->i_op->setxattr) {
983 rc = -ENOSYS;
984 goto out;
985 }
986 mutex_lock(&lower_dentry->d_inode->i_mutex);
987 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
988 size, flags);
989 mutex_unlock(&lower_dentry->d_inode->i_mutex);
990out:
991 return rc;
992}
993
994ssize_t
995ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
996 void *value, size_t size)
997{
998 int rc = 0;
999
1000 if (!lower_dentry->d_inode->i_op->getxattr) {
1001 rc = -ENOSYS;
1002 goto out;
1003 }
1004 mutex_lock(&lower_dentry->d_inode->i_mutex);
1005 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1006 size);
1007 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1008out:
1009 return rc;
1010}
1011
1012static ssize_t
1013ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1014 size_t size)
1015{
1016 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1017 value, size);
1018}
1019
1020static ssize_t
1021ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1022{
1023 int rc = 0;
1024 struct dentry *lower_dentry;
1025
1026 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1027 if (!lower_dentry->d_inode->i_op->listxattr) {
1028 rc = -ENOSYS;
1029 goto out;
1030 }
1031 mutex_lock(&lower_dentry->d_inode->i_mutex);
1032 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1033 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1034out:
1035 return rc;
1036}
1037
1038static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1039{
1040 int rc = 0;
1041 struct dentry *lower_dentry;
1042
1043 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1044 if (!lower_dentry->d_inode->i_op->removexattr) {
1045 rc = -ENOSYS;
1046 goto out;
1047 }
1048 mutex_lock(&lower_dentry->d_inode->i_mutex);
1049 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1050 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1051out:
1052 return rc;
1053}
1054
1055int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1056{
1057 if ((ecryptfs_inode_to_lower(inode)
1058 == (struct inode *)candidate_lower_inode))
1059 return 1;
1060 else
1061 return 0;
1062}
1063
1064int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1065{
1066 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1067 return 0;
1068}
1069
1070const struct inode_operations ecryptfs_symlink_iops = {
1071 .readlink = ecryptfs_readlink,
1072 .follow_link = ecryptfs_follow_link,
1073 .put_link = ecryptfs_put_link,
1074 .permission = ecryptfs_permission,
1075 .setattr = ecryptfs_setattr,
1076 .setxattr = ecryptfs_setxattr,
1077 .getxattr = ecryptfs_getxattr,
1078 .listxattr = ecryptfs_listxattr,
1079 .removexattr = ecryptfs_removexattr
1080};
1081
1082const struct inode_operations ecryptfs_dir_iops = {
1083 .create = ecryptfs_create,
1084 .lookup = ecryptfs_lookup,
1085 .link = ecryptfs_link,
1086 .unlink = ecryptfs_unlink,
1087 .symlink = ecryptfs_symlink,
1088 .mkdir = ecryptfs_mkdir,
1089 .rmdir = ecryptfs_rmdir,
1090 .mknod = ecryptfs_mknod,
1091 .rename = ecryptfs_rename,
1092 .permission = ecryptfs_permission,
1093 .setattr = ecryptfs_setattr,
1094 .setxattr = ecryptfs_setxattr,
1095 .getxattr = ecryptfs_getxattr,
1096 .listxattr = ecryptfs_listxattr,
1097 .removexattr = ecryptfs_removexattr
1098};
1099
1100const struct inode_operations ecryptfs_main_iops = {
1101 .permission = ecryptfs_permission,
1102 .setattr = ecryptfs_setattr,
1103 .setxattr = ecryptfs_setxattr,
1104 .getxattr = ecryptfs_getxattr,
1105 .listxattr = ecryptfs_listxattr,
1106 .removexattr = ecryptfs_removexattr
1107};
1108