Commit | Line | Data |
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237fead6 MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * | |
4 | * Copyright (C) 1997-2004 Erez Zadok | |
5 | * Copyright (C) 2001-2004 Stony Brook University | |
dd2a3b7a | 6 | * Copyright (C) 2004-2007 International Business Machines Corp. |
237fead6 MH |
7 | * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> |
8 | * Michael C. Thompson <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/poll.h> | |
5a0e3ad6 | 28 | #include <linux/slab.h> |
237fead6 MH |
29 | #include <linux/mount.h> |
30 | #include <linux/pagemap.h> | |
31 | #include <linux/security.h> | |
237fead6 | 32 | #include <linux/compat.h> |
0cc72dc7 | 33 | #include <linux/fs_stack.h> |
237fead6 MH |
34 | #include "ecryptfs_kernel.h" |
35 | ||
237fead6 MH |
36 | /** |
37 | * ecryptfs_read_update_atime | |
38 | * | |
39 | * generic_file_read updates the atime of upper layer inode. But, it | |
40 | * doesn't give us a chance to update the atime of the lower layer | |
41 | * inode. This function is a wrapper to generic_file_read. It | |
42 | * updates the atime of the lower level inode if generic_file_read | |
43 | * returns without any errors. This is to be used only for file reads. | |
44 | * The function to be used for directory reads is ecryptfs_read. | |
45 | */ | |
46 | static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb, | |
02797829 | 47 | struct iov_iter *to) |
237fead6 | 48 | { |
38a708d7 | 49 | ssize_t rc; |
cc18ec3c | 50 | struct path *path; |
237fead6 MH |
51 | struct file *file = iocb->ki_filp; |
52 | ||
02797829 | 53 | rc = generic_file_read_iter(iocb, to); |
237fead6 | 54 | if (rc >= 0) { |
cc18ec3c MW |
55 | path = ecryptfs_dentry_to_lower_path(file->f_path.dentry); |
56 | touch_atime(path); | |
237fead6 MH |
57 | } |
58 | return rc; | |
59 | } | |
60 | ||
61 | struct ecryptfs_getdents_callback { | |
5c0ba4e0 | 62 | struct dir_context ctx; |
2de5f059 | 63 | struct dir_context *caller; |
0747fdb2 | 64 | struct super_block *sb; |
237fead6 MH |
65 | int filldir_called; |
66 | int entries_written; | |
67 | }; | |
68 | ||
7d6c7045 | 69 | /* Inspired by generic filldir in fs/readdir.c */ |
237fead6 | 70 | static int |
ac7576f4 MS |
71 | ecryptfs_filldir(struct dir_context *ctx, const char *lower_name, |
72 | int lower_namelen, loff_t offset, u64 ino, unsigned int d_type) | |
237fead6 | 73 | { |
237fead6 | 74 | struct ecryptfs_getdents_callback *buf = |
ac7576f4 | 75 | container_of(ctx, struct ecryptfs_getdents_callback, ctx); |
a8f12864 | 76 | size_t name_size; |
addd65ad | 77 | char *name; |
237fead6 | 78 | int rc; |
237fead6 | 79 | |
237fead6 | 80 | buf->filldir_called++; |
addd65ad | 81 | rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size, |
0747fdb2 | 82 | buf->sb, lower_name, |
addd65ad MH |
83 | lower_namelen); |
84 | if (rc) { | |
85 | printk(KERN_ERR "%s: Error attempting to decode and decrypt " | |
86 | "filename [%s]; rc = [%d]\n", __func__, lower_name, | |
87 | rc); | |
237fead6 MH |
88 | goto out; |
89 | } | |
2de5f059 AV |
90 | buf->caller->pos = buf->ctx.pos; |
91 | rc = !dir_emit(buf->caller, name, name_size, ino, d_type); | |
addd65ad | 92 | kfree(name); |
2de5f059 | 93 | if (!rc) |
237fead6 MH |
94 | buf->entries_written++; |
95 | out: | |
96 | return rc; | |
97 | } | |
98 | ||
99 | /** | |
100 | * ecryptfs_readdir | |
addd65ad | 101 | * @file: The eCryptfs directory file |
2de5f059 | 102 | * @ctx: The actor to feed the entries to |
237fead6 | 103 | */ |
2de5f059 | 104 | static int ecryptfs_readdir(struct file *file, struct dir_context *ctx) |
237fead6 MH |
105 | { |
106 | int rc; | |
107 | struct file *lower_file; | |
0747fdb2 | 108 | struct inode *inode = file_inode(file); |
2de5f059 AV |
109 | struct ecryptfs_getdents_callback buf = { |
110 | .ctx.actor = ecryptfs_filldir, | |
111 | .caller = ctx, | |
0747fdb2 | 112 | .sb = inode->i_sb, |
2de5f059 | 113 | }; |
237fead6 | 114 | lower_file = ecryptfs_file_to_lower(file); |
5c0ba4e0 | 115 | rc = iterate_dir(lower_file, &buf.ctx); |
2de5f059 | 116 | ctx->pos = buf.ctx.pos; |
7d6c7045 MH |
117 | if (rc < 0) |
118 | goto out; | |
119 | if (buf.filldir_called && !buf.entries_written) | |
120 | goto out; | |
237fead6 | 121 | if (rc >= 0) |
7d6c7045 | 122 | fsstack_copy_attr_atime(inode, |
496ad9aa | 123 | file_inode(lower_file)); |
7d6c7045 | 124 | out: |
237fead6 MH |
125 | return rc; |
126 | } | |
127 | ||
128 | struct kmem_cache *ecryptfs_file_info_cache; | |
129 | ||
e3ccaa97 TH |
130 | static int read_or_initialize_metadata(struct dentry *dentry) |
131 | { | |
2b0143b5 | 132 | struct inode *inode = d_inode(dentry); |
e3ccaa97 TH |
133 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; |
134 | struct ecryptfs_crypt_stat *crypt_stat; | |
135 | int rc; | |
136 | ||
137 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
138 | mount_crypt_stat = &ecryptfs_superblock_to_private( | |
139 | inode->i_sb)->mount_crypt_stat; | |
140 | mutex_lock(&crypt_stat->cs_mutex); | |
141 | ||
142 | if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED && | |
143 | crypt_stat->flags & ECRYPTFS_KEY_VALID) { | |
144 | rc = 0; | |
145 | goto out; | |
146 | } | |
147 | ||
148 | rc = ecryptfs_read_metadata(dentry); | |
149 | if (!rc) | |
150 | goto out; | |
151 | ||
152 | if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) { | |
153 | crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED | |
154 | | ECRYPTFS_ENCRYPTED); | |
155 | rc = 0; | |
156 | goto out; | |
157 | } | |
158 | ||
159 | if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) && | |
160 | !i_size_read(ecryptfs_inode_to_lower(inode))) { | |
161 | rc = ecryptfs_initialize_file(dentry, inode); | |
162 | if (!rc) | |
163 | goto out; | |
164 | } | |
165 | ||
166 | rc = -EIO; | |
167 | out: | |
168 | mutex_unlock(&crypt_stat->cs_mutex); | |
169 | return rc; | |
170 | } | |
171 | ||
f0fe970d JM |
172 | static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma) |
173 | { | |
174 | struct file *lower_file = ecryptfs_file_to_lower(file); | |
175 | /* | |
176 | * Don't allow mmap on top of file systems that don't support it | |
177 | * natively. If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs | |
178 | * allows recursive mounting, this will need to be extended. | |
179 | */ | |
180 | if (!lower_file->f_op->mmap) | |
181 | return -ENODEV; | |
182 | return generic_file_mmap(file, vma); | |
183 | } | |
184 | ||
237fead6 MH |
185 | /** |
186 | * ecryptfs_open | |
40f0fd37 | 187 | * @inode: inode specifying file to open |
237fead6 MH |
188 | * @file: Structure to return filled in |
189 | * | |
190 | * Opens the file specified by inode. | |
191 | * | |
192 | * Returns zero on success; non-zero otherwise | |
193 | */ | |
194 | static int ecryptfs_open(struct inode *inode, struct file *file) | |
195 | { | |
196 | int rc = 0; | |
197 | struct ecryptfs_crypt_stat *crypt_stat = NULL; | |
bd243a4b | 198 | struct dentry *ecryptfs_dentry = file->f_path.dentry; |
237fead6 MH |
199 | /* Private value of ecryptfs_dentry allocated in |
200 | * ecryptfs_lookup() */ | |
237fead6 | 201 | struct ecryptfs_file_info *file_info; |
237fead6 MH |
202 | |
203 | /* Released in ecryptfs_release or end of function if failure */ | |
c3762229 | 204 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); |
237fead6 MH |
205 | ecryptfs_set_file_private(file, file_info); |
206 | if (!file_info) { | |
207 | ecryptfs_printk(KERN_ERR, | |
208 | "Error attempting to allocate memory\n"); | |
209 | rc = -ENOMEM; | |
210 | goto out; | |
211 | } | |
237fead6 | 212 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; |
237fead6 | 213 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 214 | if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) { |
237fead6 MH |
215 | ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n"); |
216 | /* Policy code enabled in future release */ | |
2ed92554 MH |
217 | crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED |
218 | | ECRYPTFS_ENCRYPTED); | |
237fead6 MH |
219 | } |
220 | mutex_unlock(&crypt_stat->cs_mutex); | |
3b06b3eb | 221 | rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode); |
27992890 RS |
222 | if (rc) { |
223 | printk(KERN_ERR "%s: Error attempting to initialize " | |
332ab16f | 224 | "the lower file for the dentry with name " |
9e78d14a DH |
225 | "[%pd]; rc = [%d]\n", __func__, |
226 | ecryptfs_dentry, rc); | |
27992890 | 227 | goto out_free; |
72b55fff | 228 | } |
0abe1169 RS |
229 | if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE) |
230 | == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) { | |
e27759d7 | 231 | rc = -EPERM; |
332ab16f | 232 | printk(KERN_WARNING "%s: Lower file is RO; eCryptfs " |
e27759d7 | 233 | "file must hence be opened RO\n", __func__); |
332ab16f | 234 | goto out_put; |
e27759d7 | 235 | } |
2ed92554 MH |
236 | ecryptfs_set_file_lower( |
237 | file, ecryptfs_inode_to_private(inode)->lower_file); | |
e3ccaa97 TH |
238 | rc = read_or_initialize_metadata(ecryptfs_dentry); |
239 | if (rc) | |
240 | goto out_put; | |
888d57bb JP |
241 | ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = " |
242 | "[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino, | |
243 | (unsigned long long)i_size_read(inode)); | |
237fead6 | 244 | goto out; |
332ab16f TH |
245 | out_put: |
246 | ecryptfs_put_lower_file(inode); | |
2ed92554 | 247 | out_free: |
237fead6 MH |
248 | kmem_cache_free(ecryptfs_file_info_cache, |
249 | ecryptfs_file_to_private(file)); | |
250 | out: | |
251 | return rc; | |
252 | } | |
253 | ||
6a480a78 AV |
254 | /** |
255 | * ecryptfs_dir_open | |
40f0fd37 | 256 | * @inode: inode specifying file to open |
6a480a78 AV |
257 | * @file: Structure to return filled in |
258 | * | |
259 | * Opens the file specified by inode. | |
260 | * | |
261 | * Returns zero on success; non-zero otherwise | |
262 | */ | |
263 | static int ecryptfs_dir_open(struct inode *inode, struct file *file) | |
264 | { | |
265 | struct dentry *ecryptfs_dentry = file->f_path.dentry; | |
266 | /* Private value of ecryptfs_dentry allocated in | |
267 | * ecryptfs_lookup() */ | |
268 | struct ecryptfs_file_info *file_info; | |
269 | struct file *lower_file; | |
270 | ||
271 | /* Released in ecryptfs_release or end of function if failure */ | |
272 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); | |
273 | ecryptfs_set_file_private(file, file_info); | |
274 | if (unlikely(!file_info)) { | |
275 | ecryptfs_printk(KERN_ERR, | |
276 | "Error attempting to allocate memory\n"); | |
277 | return -ENOMEM; | |
278 | } | |
279 | lower_file = dentry_open(ecryptfs_dentry_to_lower_path(ecryptfs_dentry), | |
280 | file->f_flags, current_cred()); | |
281 | if (IS_ERR(lower_file)) { | |
282 | printk(KERN_ERR "%s: Error attempting to initialize " | |
283 | "the lower file for the dentry with name " | |
284 | "[%pd]; rc = [%ld]\n", __func__, | |
285 | ecryptfs_dentry, PTR_ERR(lower_file)); | |
286 | kmem_cache_free(ecryptfs_file_info_cache, file_info); | |
287 | return PTR_ERR(lower_file); | |
288 | } | |
289 | ecryptfs_set_file_lower(file, lower_file); | |
290 | return 0; | |
291 | } | |
292 | ||
237fead6 MH |
293 | static int ecryptfs_flush(struct file *file, fl_owner_t td) |
294 | { | |
64e6651d TH |
295 | struct file *lower_file = ecryptfs_file_to_lower(file); |
296 | ||
72c2d531 | 297 | if (lower_file->f_op->flush) { |
64e6651d TH |
298 | filemap_write_and_wait(file->f_mapping); |
299 | return lower_file->f_op->flush(lower_file, td); | |
300 | } | |
301 | ||
302 | return 0; | |
237fead6 MH |
303 | } |
304 | ||
305 | static int ecryptfs_release(struct inode *inode, struct file *file) | |
306 | { | |
332ab16f | 307 | ecryptfs_put_lower_file(inode); |
2ed92554 MH |
308 | kmem_cache_free(ecryptfs_file_info_cache, |
309 | ecryptfs_file_to_private(file)); | |
310 | return 0; | |
237fead6 MH |
311 | } |
312 | ||
6a480a78 AV |
313 | static int ecryptfs_dir_release(struct inode *inode, struct file *file) |
314 | { | |
315 | fput(ecryptfs_file_to_lower(file)); | |
316 | kmem_cache_free(ecryptfs_file_info_cache, | |
317 | ecryptfs_file_to_private(file)); | |
318 | return 0; | |
319 | } | |
320 | ||
321 | static loff_t ecryptfs_dir_llseek(struct file *file, loff_t offset, int whence) | |
322 | { | |
323 | return vfs_llseek(ecryptfs_file_to_lower(file), offset, whence); | |
324 | } | |
325 | ||
237fead6 | 326 | static int |
02c24a82 | 327 | ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
237fead6 | 328 | { |
bc5abcf7 TH |
329 | int rc; |
330 | ||
331 | rc = filemap_write_and_wait(file->f_mapping); | |
332 | if (rc) | |
333 | return rc; | |
334 | ||
821f7494 | 335 | return vfs_fsync(ecryptfs_file_to_lower(file), datasync); |
237fead6 MH |
336 | } |
337 | ||
338 | static int ecryptfs_fasync(int fd, struct file *file, int flag) | |
339 | { | |
340 | int rc = 0; | |
341 | struct file *lower_file = NULL; | |
342 | ||
343 | lower_file = ecryptfs_file_to_lower(file); | |
72c2d531 | 344 | if (lower_file->f_op->fasync) |
237fead6 MH |
345 | rc = lower_file->f_op->fasync(fd, lower_file, flag); |
346 | return rc; | |
347 | } | |
348 | ||
c43f7b8f TH |
349 | static long |
350 | ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
351 | { | |
2000f5be | 352 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
353 | long rc = -ENOTTY; |
354 | ||
6d65261a TH |
355 | if (!lower_file->f_op->unlocked_ioctl) |
356 | return rc; | |
357 | ||
358 | switch (cmd) { | |
359 | case FITRIM: | |
360 | case FS_IOC_GETFLAGS: | |
361 | case FS_IOC_SETFLAGS: | |
362 | case FS_IOC_GETVERSION: | |
363 | case FS_IOC_SETVERSION: | |
c43f7b8f | 364 | rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); |
6d65261a TH |
365 | fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); |
366 | ||
367 | return rc; | |
368 | default: | |
369 | return rc; | |
370 | } | |
c43f7b8f TH |
371 | } |
372 | ||
373 | #ifdef CONFIG_COMPAT | |
374 | static long | |
375 | ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
376 | { | |
2000f5be | 377 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
378 | long rc = -ENOIOCTLCMD; |
379 | ||
6d65261a TH |
380 | if (!lower_file->f_op->compat_ioctl) |
381 | return rc; | |
382 | ||
383 | switch (cmd) { | |
6d65261a TH |
384 | case FS_IOC32_GETFLAGS: |
385 | case FS_IOC32_SETFLAGS: | |
386 | case FS_IOC32_GETVERSION: | |
387 | case FS_IOC32_SETVERSION: | |
c43f7b8f | 388 | rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg); |
6d65261a TH |
389 | fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); |
390 | ||
391 | return rc; | |
392 | default: | |
393 | return rc; | |
394 | } | |
c43f7b8f TH |
395 | } |
396 | #endif | |
237fead6 MH |
397 | |
398 | const struct file_operations ecryptfs_dir_fops = { | |
51a16a9c | 399 | .iterate_shared = ecryptfs_readdir, |
323ef68f | 400 | .read = generic_read_dir, |
c43f7b8f TH |
401 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
402 | #ifdef CONFIG_COMPAT | |
403 | .compat_ioctl = ecryptfs_compat_ioctl, | |
404 | #endif | |
6a480a78 AV |
405 | .open = ecryptfs_dir_open, |
406 | .release = ecryptfs_dir_release, | |
237fead6 | 407 | .fsync = ecryptfs_fsync, |
6a480a78 | 408 | .llseek = ecryptfs_dir_llseek, |
237fead6 MH |
409 | }; |
410 | ||
411 | const struct file_operations ecryptfs_main_fops = { | |
53a2731f | 412 | .llseek = generic_file_llseek, |
02797829 | 413 | .read_iter = ecryptfs_read_update_atime, |
8174202b | 414 | .write_iter = generic_file_write_iter, |
c43f7b8f TH |
415 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
416 | #ifdef CONFIG_COMPAT | |
417 | .compat_ioctl = ecryptfs_compat_ioctl, | |
418 | #endif | |
f0fe970d | 419 | .mmap = ecryptfs_mmap, |
237fead6 MH |
420 | .open = ecryptfs_open, |
421 | .flush = ecryptfs_flush, | |
422 | .release = ecryptfs_release, | |
423 | .fsync = ecryptfs_fsync, | |
424 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 425 | .splice_read = generic_file_splice_read, |
237fead6 | 426 | }; |