Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
a62187eb | 2 | /* |
237fead6 MH |
3 | * eCryptfs: Linux filesystem encryption layer |
4 | * | |
5 | * Copyright (C) 1997-2004 Erez Zadok | |
6 | * Copyright (C) 2001-2004 Stony Brook University | |
dd2a3b7a | 7 | * Copyright (C) 2004-2007 International Business Machines Corp. |
237fead6 MH |
8 | * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> |
9 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
237fead6 MH |
10 | */ |
11 | ||
12 | #include <linux/file.h> | |
13 | #include <linux/poll.h> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
237fead6 MH |
15 | #include <linux/mount.h> |
16 | #include <linux/pagemap.h> | |
17 | #include <linux/security.h> | |
237fead6 | 18 | #include <linux/compat.h> |
0cc72dc7 | 19 | #include <linux/fs_stack.h> |
237fead6 MH |
20 | #include "ecryptfs_kernel.h" |
21 | ||
a62187eb | 22 | /* |
237fead6 MH |
23 | * ecryptfs_read_update_atime |
24 | * | |
25 | * generic_file_read updates the atime of upper layer inode. But, it | |
26 | * doesn't give us a chance to update the atime of the lower layer | |
27 | * inode. This function is a wrapper to generic_file_read. It | |
28 | * updates the atime of the lower level inode if generic_file_read | |
29 | * returns without any errors. This is to be used only for file reads. | |
30 | * The function to be used for directory reads is ecryptfs_read. | |
31 | */ | |
32 | static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb, | |
02797829 | 33 | struct iov_iter *to) |
237fead6 | 34 | { |
38a708d7 | 35 | ssize_t rc; |
88569546 | 36 | const struct path *path; |
237fead6 MH |
37 | struct file *file = iocb->ki_filp; |
38 | ||
02797829 | 39 | rc = generic_file_read_iter(iocb, to); |
237fead6 | 40 | if (rc >= 0) { |
cc18ec3c MW |
41 | path = ecryptfs_dentry_to_lower_path(file->f_path.dentry); |
42 | touch_atime(path); | |
237fead6 MH |
43 | } |
44 | return rc; | |
45 | } | |
46 | ||
390df3b8 DH |
47 | /* |
48 | * ecryptfs_splice_read_update_atime | |
49 | * | |
2cb1e089 | 50 | * filemap_splice_read updates the atime of upper layer inode. But, it |
390df3b8 DH |
51 | * doesn't give us a chance to update the atime of the lower layer inode. This |
52 | * function is a wrapper to generic_file_read. It updates the atime of the | |
53 | * lower level inode if generic_file_read returns without any errors. This is | |
54 | * to be used only for file reads. The function to be used for directory reads | |
55 | * is ecryptfs_read. | |
56 | */ | |
57 | static ssize_t ecryptfs_splice_read_update_atime(struct file *in, loff_t *ppos, | |
58 | struct pipe_inode_info *pipe, | |
59 | size_t len, unsigned int flags) | |
60 | { | |
61 | ssize_t rc; | |
62 | const struct path *path; | |
63 | ||
2cb1e089 | 64 | rc = filemap_splice_read(in, ppos, pipe, len, flags); |
390df3b8 DH |
65 | if (rc >= 0) { |
66 | path = ecryptfs_dentry_to_lower_path(in->f_path.dentry); | |
67 | touch_atime(path); | |
68 | } | |
69 | return rc; | |
70 | } | |
71 | ||
237fead6 | 72 | struct ecryptfs_getdents_callback { |
5c0ba4e0 | 73 | struct dir_context ctx; |
2de5f059 | 74 | struct dir_context *caller; |
0747fdb2 | 75 | struct super_block *sb; |
237fead6 MH |
76 | int filldir_called; |
77 | int entries_written; | |
78 | }; | |
79 | ||
7d6c7045 | 80 | /* Inspired by generic filldir in fs/readdir.c */ |
25885a35 | 81 | static bool |
ac7576f4 MS |
82 | ecryptfs_filldir(struct dir_context *ctx, const char *lower_name, |
83 | int lower_namelen, loff_t offset, u64 ino, unsigned int d_type) | |
237fead6 | 84 | { |
237fead6 | 85 | struct ecryptfs_getdents_callback *buf = |
ac7576f4 | 86 | container_of(ctx, struct ecryptfs_getdents_callback, ctx); |
a8f12864 | 87 | size_t name_size; |
addd65ad | 88 | char *name; |
25885a35 AV |
89 | int err; |
90 | bool res; | |
237fead6 | 91 | |
237fead6 | 92 | buf->filldir_called++; |
25885a35 AV |
93 | err = ecryptfs_decode_and_decrypt_filename(&name, &name_size, |
94 | buf->sb, lower_name, | |
95 | lower_namelen); | |
96 | if (err) { | |
97 | if (err != -EINVAL) { | |
e86281e7 TH |
98 | ecryptfs_printk(KERN_DEBUG, |
99 | "%s: Error attempting to decode and decrypt filename [%s]; rc = [%d]\n", | |
25885a35 AV |
100 | __func__, lower_name, err); |
101 | return false; | |
e86281e7 TH |
102 | } |
103 | ||
104 | /* Mask -EINVAL errors as these are most likely due a plaintext | |
105 | * filename present in the lower filesystem despite filename | |
106 | * encryption being enabled. One unavoidable example would be | |
107 | * the "lost+found" dentry in the root directory of an Ext4 | |
108 | * filesystem. | |
109 | */ | |
25885a35 | 110 | return true; |
237fead6 | 111 | } |
e86281e7 | 112 | |
2de5f059 | 113 | buf->caller->pos = buf->ctx.pos; |
25885a35 | 114 | res = dir_emit(buf->caller, name, name_size, ino, d_type); |
addd65ad | 115 | kfree(name); |
25885a35 | 116 | if (res) |
237fead6 | 117 | buf->entries_written++; |
25885a35 | 118 | return res; |
237fead6 MH |
119 | } |
120 | ||
121 | /** | |
122 | * ecryptfs_readdir | |
addd65ad | 123 | * @file: The eCryptfs directory file |
2de5f059 | 124 | * @ctx: The actor to feed the entries to |
237fead6 | 125 | */ |
2de5f059 | 126 | static int ecryptfs_readdir(struct file *file, struct dir_context *ctx) |
237fead6 MH |
127 | { |
128 | int rc; | |
129 | struct file *lower_file; | |
0747fdb2 | 130 | struct inode *inode = file_inode(file); |
2de5f059 AV |
131 | struct ecryptfs_getdents_callback buf = { |
132 | .ctx.actor = ecryptfs_filldir, | |
133 | .caller = ctx, | |
0747fdb2 | 134 | .sb = inode->i_sb, |
2de5f059 | 135 | }; |
237fead6 | 136 | lower_file = ecryptfs_file_to_lower(file); |
5c0ba4e0 | 137 | rc = iterate_dir(lower_file, &buf.ctx); |
2de5f059 | 138 | ctx->pos = buf.ctx.pos; |
25885a35 AV |
139 | if (rc >= 0 && (buf.entries_written || !buf.filldir_called)) |
140 | fsstack_copy_attr_atime(inode, file_inode(lower_file)); | |
237fead6 MH |
141 | return rc; |
142 | } | |
143 | ||
144 | struct kmem_cache *ecryptfs_file_info_cache; | |
145 | ||
e3ccaa97 TH |
146 | static int read_or_initialize_metadata(struct dentry *dentry) |
147 | { | |
2b0143b5 | 148 | struct inode *inode = d_inode(dentry); |
e3ccaa97 TH |
149 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; |
150 | struct ecryptfs_crypt_stat *crypt_stat; | |
151 | int rc; | |
152 | ||
153 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
154 | mount_crypt_stat = &ecryptfs_superblock_to_private( | |
155 | inode->i_sb)->mount_crypt_stat; | |
156 | mutex_lock(&crypt_stat->cs_mutex); | |
157 | ||
158 | if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED && | |
159 | crypt_stat->flags & ECRYPTFS_KEY_VALID) { | |
160 | rc = 0; | |
161 | goto out; | |
162 | } | |
163 | ||
164 | rc = ecryptfs_read_metadata(dentry); | |
165 | if (!rc) | |
166 | goto out; | |
167 | ||
168 | if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) { | |
169 | crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED | |
170 | | ECRYPTFS_ENCRYPTED); | |
171 | rc = 0; | |
172 | goto out; | |
173 | } | |
174 | ||
175 | if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) && | |
176 | !i_size_read(ecryptfs_inode_to_lower(inode))) { | |
177 | rc = ecryptfs_initialize_file(dentry, inode); | |
178 | if (!rc) | |
179 | goto out; | |
180 | } | |
181 | ||
182 | rc = -EIO; | |
183 | out: | |
184 | mutex_unlock(&crypt_stat->cs_mutex); | |
185 | return rc; | |
186 | } | |
187 | ||
f0fe970d JM |
188 | static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma) |
189 | { | |
190 | struct file *lower_file = ecryptfs_file_to_lower(file); | |
191 | /* | |
192 | * Don't allow mmap on top of file systems that don't support it | |
193 | * natively. If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs | |
194 | * allows recursive mounting, this will need to be extended. | |
195 | */ | |
196 | if (!lower_file->f_op->mmap) | |
197 | return -ENODEV; | |
198 | return generic_file_mmap(file, vma); | |
199 | } | |
200 | ||
237fead6 MH |
201 | /** |
202 | * ecryptfs_open | |
40f0fd37 | 203 | * @inode: inode specifying file to open |
237fead6 MH |
204 | * @file: Structure to return filled in |
205 | * | |
206 | * Opens the file specified by inode. | |
207 | * | |
208 | * Returns zero on success; non-zero otherwise | |
209 | */ | |
210 | static int ecryptfs_open(struct inode *inode, struct file *file) | |
211 | { | |
212 | int rc = 0; | |
213 | struct ecryptfs_crypt_stat *crypt_stat = NULL; | |
bd243a4b | 214 | struct dentry *ecryptfs_dentry = file->f_path.dentry; |
237fead6 MH |
215 | /* Private value of ecryptfs_dentry allocated in |
216 | * ecryptfs_lookup() */ | |
237fead6 | 217 | struct ecryptfs_file_info *file_info; |
237fead6 MH |
218 | |
219 | /* Released in ecryptfs_release or end of function if failure */ | |
c3762229 | 220 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); |
237fead6 MH |
221 | ecryptfs_set_file_private(file, file_info); |
222 | if (!file_info) { | |
223 | ecryptfs_printk(KERN_ERR, | |
224 | "Error attempting to allocate memory\n"); | |
225 | rc = -ENOMEM; | |
226 | goto out; | |
227 | } | |
237fead6 | 228 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; |
237fead6 | 229 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 230 | if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) { |
237fead6 MH |
231 | ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n"); |
232 | /* Policy code enabled in future release */ | |
2ed92554 MH |
233 | crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED |
234 | | ECRYPTFS_ENCRYPTED); | |
237fead6 MH |
235 | } |
236 | mutex_unlock(&crypt_stat->cs_mutex); | |
3b06b3eb | 237 | rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode); |
27992890 RS |
238 | if (rc) { |
239 | printk(KERN_ERR "%s: Error attempting to initialize " | |
332ab16f | 240 | "the lower file for the dentry with name " |
9e78d14a DH |
241 | "[%pd]; rc = [%d]\n", __func__, |
242 | ecryptfs_dentry, rc); | |
27992890 | 243 | goto out_free; |
72b55fff | 244 | } |
0abe1169 RS |
245 | if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE) |
246 | == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) { | |
e27759d7 | 247 | rc = -EPERM; |
332ab16f | 248 | printk(KERN_WARNING "%s: Lower file is RO; eCryptfs " |
e27759d7 | 249 | "file must hence be opened RO\n", __func__); |
332ab16f | 250 | goto out_put; |
e27759d7 | 251 | } |
2ed92554 MH |
252 | ecryptfs_set_file_lower( |
253 | file, ecryptfs_inode_to_private(inode)->lower_file); | |
e3ccaa97 TH |
254 | rc = read_or_initialize_metadata(ecryptfs_dentry); |
255 | if (rc) | |
256 | goto out_put; | |
888d57bb JP |
257 | ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = " |
258 | "[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino, | |
259 | (unsigned long long)i_size_read(inode)); | |
237fead6 | 260 | goto out; |
332ab16f TH |
261 | out_put: |
262 | ecryptfs_put_lower_file(inode); | |
2ed92554 | 263 | out_free: |
237fead6 MH |
264 | kmem_cache_free(ecryptfs_file_info_cache, |
265 | ecryptfs_file_to_private(file)); | |
266 | out: | |
267 | return rc; | |
268 | } | |
269 | ||
6a480a78 AV |
270 | /** |
271 | * ecryptfs_dir_open | |
40f0fd37 | 272 | * @inode: inode specifying file to open |
6a480a78 AV |
273 | * @file: Structure to return filled in |
274 | * | |
275 | * Opens the file specified by inode. | |
276 | * | |
277 | * Returns zero on success; non-zero otherwise | |
278 | */ | |
279 | static int ecryptfs_dir_open(struct inode *inode, struct file *file) | |
280 | { | |
281 | struct dentry *ecryptfs_dentry = file->f_path.dentry; | |
282 | /* Private value of ecryptfs_dentry allocated in | |
283 | * ecryptfs_lookup() */ | |
284 | struct ecryptfs_file_info *file_info; | |
285 | struct file *lower_file; | |
286 | ||
287 | /* Released in ecryptfs_release or end of function if failure */ | |
288 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); | |
289 | ecryptfs_set_file_private(file, file_info); | |
290 | if (unlikely(!file_info)) { | |
291 | ecryptfs_printk(KERN_ERR, | |
292 | "Error attempting to allocate memory\n"); | |
293 | return -ENOMEM; | |
294 | } | |
295 | lower_file = dentry_open(ecryptfs_dentry_to_lower_path(ecryptfs_dentry), | |
296 | file->f_flags, current_cred()); | |
297 | if (IS_ERR(lower_file)) { | |
298 | printk(KERN_ERR "%s: Error attempting to initialize " | |
299 | "the lower file for the dentry with name " | |
300 | "[%pd]; rc = [%ld]\n", __func__, | |
301 | ecryptfs_dentry, PTR_ERR(lower_file)); | |
302 | kmem_cache_free(ecryptfs_file_info_cache, file_info); | |
303 | return PTR_ERR(lower_file); | |
304 | } | |
305 | ecryptfs_set_file_lower(file, lower_file); | |
306 | return 0; | |
307 | } | |
308 | ||
237fead6 MH |
309 | static int ecryptfs_flush(struct file *file, fl_owner_t td) |
310 | { | |
64e6651d TH |
311 | struct file *lower_file = ecryptfs_file_to_lower(file); |
312 | ||
72c2d531 | 313 | if (lower_file->f_op->flush) { |
64e6651d TH |
314 | filemap_write_and_wait(file->f_mapping); |
315 | return lower_file->f_op->flush(lower_file, td); | |
316 | } | |
317 | ||
318 | return 0; | |
237fead6 MH |
319 | } |
320 | ||
321 | static int ecryptfs_release(struct inode *inode, struct file *file) | |
322 | { | |
332ab16f | 323 | ecryptfs_put_lower_file(inode); |
2ed92554 MH |
324 | kmem_cache_free(ecryptfs_file_info_cache, |
325 | ecryptfs_file_to_private(file)); | |
326 | return 0; | |
237fead6 MH |
327 | } |
328 | ||
6a480a78 AV |
329 | static int ecryptfs_dir_release(struct inode *inode, struct file *file) |
330 | { | |
331 | fput(ecryptfs_file_to_lower(file)); | |
332 | kmem_cache_free(ecryptfs_file_info_cache, | |
333 | ecryptfs_file_to_private(file)); | |
334 | return 0; | |
335 | } | |
336 | ||
337 | static loff_t ecryptfs_dir_llseek(struct file *file, loff_t offset, int whence) | |
338 | { | |
339 | return vfs_llseek(ecryptfs_file_to_lower(file), offset, whence); | |
340 | } | |
341 | ||
237fead6 | 342 | static int |
02c24a82 | 343 | ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
237fead6 | 344 | { |
bc5abcf7 TH |
345 | int rc; |
346 | ||
6d4b5124 | 347 | rc = file_write_and_wait(file); |
bc5abcf7 TH |
348 | if (rc) |
349 | return rc; | |
350 | ||
821f7494 | 351 | return vfs_fsync(ecryptfs_file_to_lower(file), datasync); |
237fead6 MH |
352 | } |
353 | ||
354 | static int ecryptfs_fasync(int fd, struct file *file, int flag) | |
355 | { | |
356 | int rc = 0; | |
357 | struct file *lower_file = NULL; | |
358 | ||
359 | lower_file = ecryptfs_file_to_lower(file); | |
72c2d531 | 360 | if (lower_file->f_op->fasync) |
237fead6 MH |
361 | rc = lower_file->f_op->fasync(fd, lower_file, flag); |
362 | return rc; | |
363 | } | |
364 | ||
c43f7b8f TH |
365 | static long |
366 | ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
367 | { | |
2000f5be | 368 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
369 | long rc = -ENOTTY; |
370 | ||
6d65261a TH |
371 | if (!lower_file->f_op->unlocked_ioctl) |
372 | return rc; | |
373 | ||
374 | switch (cmd) { | |
375 | case FITRIM: | |
376 | case FS_IOC_GETFLAGS: | |
377 | case FS_IOC_SETFLAGS: | |
378 | case FS_IOC_GETVERSION: | |
379 | case FS_IOC_SETVERSION: | |
c43f7b8f | 380 | rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); |
6d65261a TH |
381 | fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); |
382 | ||
383 | return rc; | |
384 | default: | |
385 | return rc; | |
386 | } | |
c43f7b8f TH |
387 | } |
388 | ||
389 | #ifdef CONFIG_COMPAT | |
390 | static long | |
391 | ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
392 | { | |
2000f5be | 393 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
394 | long rc = -ENOIOCTLCMD; |
395 | ||
6d65261a TH |
396 | if (!lower_file->f_op->compat_ioctl) |
397 | return rc; | |
398 | ||
399 | switch (cmd) { | |
314999dc | 400 | case FITRIM: |
6d65261a TH |
401 | case FS_IOC32_GETFLAGS: |
402 | case FS_IOC32_SETFLAGS: | |
403 | case FS_IOC32_GETVERSION: | |
404 | case FS_IOC32_SETVERSION: | |
c43f7b8f | 405 | rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg); |
6d65261a TH |
406 | fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); |
407 | ||
408 | return rc; | |
409 | default: | |
410 | return rc; | |
411 | } | |
c43f7b8f TH |
412 | } |
413 | #endif | |
237fead6 MH |
414 | |
415 | const struct file_operations ecryptfs_dir_fops = { | |
51a16a9c | 416 | .iterate_shared = ecryptfs_readdir, |
323ef68f | 417 | .read = generic_read_dir, |
c43f7b8f TH |
418 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
419 | #ifdef CONFIG_COMPAT | |
420 | .compat_ioctl = ecryptfs_compat_ioctl, | |
421 | #endif | |
6a480a78 AV |
422 | .open = ecryptfs_dir_open, |
423 | .release = ecryptfs_dir_release, | |
237fead6 | 424 | .fsync = ecryptfs_fsync, |
6a480a78 | 425 | .llseek = ecryptfs_dir_llseek, |
237fead6 MH |
426 | }; |
427 | ||
428 | const struct file_operations ecryptfs_main_fops = { | |
53a2731f | 429 | .llseek = generic_file_llseek, |
02797829 | 430 | .read_iter = ecryptfs_read_update_atime, |
8174202b | 431 | .write_iter = generic_file_write_iter, |
c43f7b8f TH |
432 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
433 | #ifdef CONFIG_COMPAT | |
434 | .compat_ioctl = ecryptfs_compat_ioctl, | |
435 | #endif | |
f0fe970d | 436 | .mmap = ecryptfs_mmap, |
237fead6 MH |
437 | .open = ecryptfs_open, |
438 | .flush = ecryptfs_flush, | |
439 | .release = ecryptfs_release, | |
440 | .fsync = ecryptfs_fsync, | |
441 | .fasync = ecryptfs_fasync, | |
390df3b8 | 442 | .splice_read = ecryptfs_splice_read_update_atime, |
237fead6 | 443 | }; |