Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
237fead6 MH |
2 | /** |
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 | ||
237fead6 MH |
22 | /** |
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; |
cc18ec3c | 36 | 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 | ||
47 | struct ecryptfs_getdents_callback { | |
5c0ba4e0 | 48 | struct dir_context ctx; |
2de5f059 | 49 | struct dir_context *caller; |
0747fdb2 | 50 | struct super_block *sb; |
237fead6 MH |
51 | int filldir_called; |
52 | int entries_written; | |
53 | }; | |
54 | ||
7d6c7045 | 55 | /* Inspired by generic filldir in fs/readdir.c */ |
237fead6 | 56 | static int |
ac7576f4 MS |
57 | ecryptfs_filldir(struct dir_context *ctx, const char *lower_name, |
58 | int lower_namelen, loff_t offset, u64 ino, unsigned int d_type) | |
237fead6 | 59 | { |
237fead6 | 60 | struct ecryptfs_getdents_callback *buf = |
ac7576f4 | 61 | container_of(ctx, struct ecryptfs_getdents_callback, ctx); |
a8f12864 | 62 | size_t name_size; |
addd65ad | 63 | char *name; |
237fead6 | 64 | int rc; |
237fead6 | 65 | |
237fead6 | 66 | buf->filldir_called++; |
addd65ad | 67 | rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size, |
0747fdb2 | 68 | buf->sb, lower_name, |
addd65ad MH |
69 | lower_namelen); |
70 | if (rc) { | |
e86281e7 TH |
71 | if (rc != -EINVAL) { |
72 | ecryptfs_printk(KERN_DEBUG, | |
73 | "%s: Error attempting to decode and decrypt filename [%s]; rc = [%d]\n", | |
74 | __func__, lower_name, rc); | |
75 | return rc; | |
76 | } | |
77 | ||
78 | /* Mask -EINVAL errors as these are most likely due a plaintext | |
79 | * filename present in the lower filesystem despite filename | |
80 | * encryption being enabled. One unavoidable example would be | |
81 | * the "lost+found" dentry in the root directory of an Ext4 | |
82 | * filesystem. | |
83 | */ | |
84 | return 0; | |
237fead6 | 85 | } |
e86281e7 | 86 | |
2de5f059 AV |
87 | buf->caller->pos = buf->ctx.pos; |
88 | rc = !dir_emit(buf->caller, name, name_size, ino, d_type); | |
addd65ad | 89 | kfree(name); |
2de5f059 | 90 | if (!rc) |
237fead6 | 91 | buf->entries_written++; |
e86281e7 | 92 | |
237fead6 MH |
93 | return rc; |
94 | } | |
95 | ||
96 | /** | |
97 | * ecryptfs_readdir | |
addd65ad | 98 | * @file: The eCryptfs directory file |
2de5f059 | 99 | * @ctx: The actor to feed the entries to |
237fead6 | 100 | */ |
2de5f059 | 101 | static int ecryptfs_readdir(struct file *file, struct dir_context *ctx) |
237fead6 MH |
102 | { |
103 | int rc; | |
104 | struct file *lower_file; | |
0747fdb2 | 105 | struct inode *inode = file_inode(file); |
2de5f059 AV |
106 | struct ecryptfs_getdents_callback buf = { |
107 | .ctx.actor = ecryptfs_filldir, | |
108 | .caller = ctx, | |
0747fdb2 | 109 | .sb = inode->i_sb, |
2de5f059 | 110 | }; |
237fead6 | 111 | lower_file = ecryptfs_file_to_lower(file); |
5c0ba4e0 | 112 | rc = iterate_dir(lower_file, &buf.ctx); |
2de5f059 | 113 | ctx->pos = buf.ctx.pos; |
7d6c7045 MH |
114 | if (rc < 0) |
115 | goto out; | |
116 | if (buf.filldir_called && !buf.entries_written) | |
117 | goto out; | |
237fead6 | 118 | if (rc >= 0) |
7d6c7045 | 119 | fsstack_copy_attr_atime(inode, |
496ad9aa | 120 | file_inode(lower_file)); |
7d6c7045 | 121 | out: |
237fead6 MH |
122 | return rc; |
123 | } | |
124 | ||
125 | struct kmem_cache *ecryptfs_file_info_cache; | |
126 | ||
e3ccaa97 TH |
127 | static int read_or_initialize_metadata(struct dentry *dentry) |
128 | { | |
2b0143b5 | 129 | struct inode *inode = d_inode(dentry); |
e3ccaa97 TH |
130 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; |
131 | struct ecryptfs_crypt_stat *crypt_stat; | |
132 | int rc; | |
133 | ||
134 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
135 | mount_crypt_stat = &ecryptfs_superblock_to_private( | |
136 | inode->i_sb)->mount_crypt_stat; | |
137 | mutex_lock(&crypt_stat->cs_mutex); | |
138 | ||
139 | if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED && | |
140 | crypt_stat->flags & ECRYPTFS_KEY_VALID) { | |
141 | rc = 0; | |
142 | goto out; | |
143 | } | |
144 | ||
145 | rc = ecryptfs_read_metadata(dentry); | |
146 | if (!rc) | |
147 | goto out; | |
148 | ||
149 | if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) { | |
150 | crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED | |
151 | | ECRYPTFS_ENCRYPTED); | |
152 | rc = 0; | |
153 | goto out; | |
154 | } | |
155 | ||
156 | if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) && | |
157 | !i_size_read(ecryptfs_inode_to_lower(inode))) { | |
158 | rc = ecryptfs_initialize_file(dentry, inode); | |
159 | if (!rc) | |
160 | goto out; | |
161 | } | |
162 | ||
163 | rc = -EIO; | |
164 | out: | |
165 | mutex_unlock(&crypt_stat->cs_mutex); | |
166 | return rc; | |
167 | } | |
168 | ||
f0fe970d JM |
169 | static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma) |
170 | { | |
171 | struct file *lower_file = ecryptfs_file_to_lower(file); | |
172 | /* | |
173 | * Don't allow mmap on top of file systems that don't support it | |
174 | * natively. If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs | |
175 | * allows recursive mounting, this will need to be extended. | |
176 | */ | |
177 | if (!lower_file->f_op->mmap) | |
178 | return -ENODEV; | |
179 | return generic_file_mmap(file, vma); | |
180 | } | |
181 | ||
237fead6 MH |
182 | /** |
183 | * ecryptfs_open | |
40f0fd37 | 184 | * @inode: inode specifying file to open |
237fead6 MH |
185 | * @file: Structure to return filled in |
186 | * | |
187 | * Opens the file specified by inode. | |
188 | * | |
189 | * Returns zero on success; non-zero otherwise | |
190 | */ | |
191 | static int ecryptfs_open(struct inode *inode, struct file *file) | |
192 | { | |
193 | int rc = 0; | |
194 | struct ecryptfs_crypt_stat *crypt_stat = NULL; | |
bd243a4b | 195 | struct dentry *ecryptfs_dentry = file->f_path.dentry; |
237fead6 MH |
196 | /* Private value of ecryptfs_dentry allocated in |
197 | * ecryptfs_lookup() */ | |
237fead6 | 198 | struct ecryptfs_file_info *file_info; |
237fead6 MH |
199 | |
200 | /* Released in ecryptfs_release or end of function if failure */ | |
c3762229 | 201 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); |
237fead6 MH |
202 | ecryptfs_set_file_private(file, file_info); |
203 | if (!file_info) { | |
204 | ecryptfs_printk(KERN_ERR, | |
205 | "Error attempting to allocate memory\n"); | |
206 | rc = -ENOMEM; | |
207 | goto out; | |
208 | } | |
237fead6 | 209 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; |
237fead6 | 210 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 211 | if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) { |
237fead6 MH |
212 | ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n"); |
213 | /* Policy code enabled in future release */ | |
2ed92554 MH |
214 | crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED |
215 | | ECRYPTFS_ENCRYPTED); | |
237fead6 MH |
216 | } |
217 | mutex_unlock(&crypt_stat->cs_mutex); | |
3b06b3eb | 218 | rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode); |
27992890 RS |
219 | if (rc) { |
220 | printk(KERN_ERR "%s: Error attempting to initialize " | |
332ab16f | 221 | "the lower file for the dentry with name " |
9e78d14a DH |
222 | "[%pd]; rc = [%d]\n", __func__, |
223 | ecryptfs_dentry, rc); | |
27992890 | 224 | goto out_free; |
72b55fff | 225 | } |
0abe1169 RS |
226 | if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE) |
227 | == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) { | |
e27759d7 | 228 | rc = -EPERM; |
332ab16f | 229 | printk(KERN_WARNING "%s: Lower file is RO; eCryptfs " |
e27759d7 | 230 | "file must hence be opened RO\n", __func__); |
332ab16f | 231 | goto out_put; |
e27759d7 | 232 | } |
2ed92554 MH |
233 | ecryptfs_set_file_lower( |
234 | file, ecryptfs_inode_to_private(inode)->lower_file); | |
e3ccaa97 TH |
235 | rc = read_or_initialize_metadata(ecryptfs_dentry); |
236 | if (rc) | |
237 | goto out_put; | |
888d57bb JP |
238 | ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = " |
239 | "[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino, | |
240 | (unsigned long long)i_size_read(inode)); | |
237fead6 | 241 | goto out; |
332ab16f TH |
242 | out_put: |
243 | ecryptfs_put_lower_file(inode); | |
2ed92554 | 244 | out_free: |
237fead6 MH |
245 | kmem_cache_free(ecryptfs_file_info_cache, |
246 | ecryptfs_file_to_private(file)); | |
247 | out: | |
248 | return rc; | |
249 | } | |
250 | ||
6a480a78 AV |
251 | /** |
252 | * ecryptfs_dir_open | |
40f0fd37 | 253 | * @inode: inode specifying file to open |
6a480a78 AV |
254 | * @file: Structure to return filled in |
255 | * | |
256 | * Opens the file specified by inode. | |
257 | * | |
258 | * Returns zero on success; non-zero otherwise | |
259 | */ | |
260 | static int ecryptfs_dir_open(struct inode *inode, struct file *file) | |
261 | { | |
262 | struct dentry *ecryptfs_dentry = file->f_path.dentry; | |
263 | /* Private value of ecryptfs_dentry allocated in | |
264 | * ecryptfs_lookup() */ | |
265 | struct ecryptfs_file_info *file_info; | |
266 | struct file *lower_file; | |
267 | ||
268 | /* Released in ecryptfs_release or end of function if failure */ | |
269 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); | |
270 | ecryptfs_set_file_private(file, file_info); | |
271 | if (unlikely(!file_info)) { | |
272 | ecryptfs_printk(KERN_ERR, | |
273 | "Error attempting to allocate memory\n"); | |
274 | return -ENOMEM; | |
275 | } | |
276 | lower_file = dentry_open(ecryptfs_dentry_to_lower_path(ecryptfs_dentry), | |
277 | file->f_flags, current_cred()); | |
278 | if (IS_ERR(lower_file)) { | |
279 | printk(KERN_ERR "%s: Error attempting to initialize " | |
280 | "the lower file for the dentry with name " | |
281 | "[%pd]; rc = [%ld]\n", __func__, | |
282 | ecryptfs_dentry, PTR_ERR(lower_file)); | |
283 | kmem_cache_free(ecryptfs_file_info_cache, file_info); | |
284 | return PTR_ERR(lower_file); | |
285 | } | |
286 | ecryptfs_set_file_lower(file, lower_file); | |
287 | return 0; | |
288 | } | |
289 | ||
237fead6 MH |
290 | static int ecryptfs_flush(struct file *file, fl_owner_t td) |
291 | { | |
64e6651d TH |
292 | struct file *lower_file = ecryptfs_file_to_lower(file); |
293 | ||
72c2d531 | 294 | if (lower_file->f_op->flush) { |
64e6651d TH |
295 | filemap_write_and_wait(file->f_mapping); |
296 | return lower_file->f_op->flush(lower_file, td); | |
297 | } | |
298 | ||
299 | return 0; | |
237fead6 MH |
300 | } |
301 | ||
302 | static int ecryptfs_release(struct inode *inode, struct file *file) | |
303 | { | |
332ab16f | 304 | ecryptfs_put_lower_file(inode); |
2ed92554 MH |
305 | kmem_cache_free(ecryptfs_file_info_cache, |
306 | ecryptfs_file_to_private(file)); | |
307 | return 0; | |
237fead6 MH |
308 | } |
309 | ||
6a480a78 AV |
310 | static int ecryptfs_dir_release(struct inode *inode, struct file *file) |
311 | { | |
312 | fput(ecryptfs_file_to_lower(file)); | |
313 | kmem_cache_free(ecryptfs_file_info_cache, | |
314 | ecryptfs_file_to_private(file)); | |
315 | return 0; | |
316 | } | |
317 | ||
318 | static loff_t ecryptfs_dir_llseek(struct file *file, loff_t offset, int whence) | |
319 | { | |
320 | return vfs_llseek(ecryptfs_file_to_lower(file), offset, whence); | |
321 | } | |
322 | ||
237fead6 | 323 | static int |
02c24a82 | 324 | ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
237fead6 | 325 | { |
bc5abcf7 TH |
326 | int rc; |
327 | ||
6d4b5124 | 328 | rc = file_write_and_wait(file); |
bc5abcf7 TH |
329 | if (rc) |
330 | return rc; | |
331 | ||
821f7494 | 332 | return vfs_fsync(ecryptfs_file_to_lower(file), datasync); |
237fead6 MH |
333 | } |
334 | ||
335 | static int ecryptfs_fasync(int fd, struct file *file, int flag) | |
336 | { | |
337 | int rc = 0; | |
338 | struct file *lower_file = NULL; | |
339 | ||
340 | lower_file = ecryptfs_file_to_lower(file); | |
72c2d531 | 341 | if (lower_file->f_op->fasync) |
237fead6 MH |
342 | rc = lower_file->f_op->fasync(fd, lower_file, flag); |
343 | return rc; | |
344 | } | |
345 | ||
c43f7b8f TH |
346 | static long |
347 | ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
348 | { | |
2000f5be | 349 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
350 | long rc = -ENOTTY; |
351 | ||
6d65261a TH |
352 | if (!lower_file->f_op->unlocked_ioctl) |
353 | return rc; | |
354 | ||
355 | switch (cmd) { | |
356 | case FITRIM: | |
357 | case FS_IOC_GETFLAGS: | |
358 | case FS_IOC_SETFLAGS: | |
359 | case FS_IOC_GETVERSION: | |
360 | case FS_IOC_SETVERSION: | |
c43f7b8f | 361 | rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); |
6d65261a TH |
362 | fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); |
363 | ||
364 | return rc; | |
365 | default: | |
366 | return rc; | |
367 | } | |
c43f7b8f TH |
368 | } |
369 | ||
370 | #ifdef CONFIG_COMPAT | |
371 | static long | |
372 | ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
373 | { | |
2000f5be | 374 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
375 | long rc = -ENOIOCTLCMD; |
376 | ||
6d65261a TH |
377 | if (!lower_file->f_op->compat_ioctl) |
378 | return rc; | |
379 | ||
380 | switch (cmd) { | |
6d65261a TH |
381 | case FS_IOC32_GETFLAGS: |
382 | case FS_IOC32_SETFLAGS: | |
383 | case FS_IOC32_GETVERSION: | |
384 | case FS_IOC32_SETVERSION: | |
c43f7b8f | 385 | rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg); |
6d65261a TH |
386 | fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); |
387 | ||
388 | return rc; | |
389 | default: | |
390 | return rc; | |
391 | } | |
c43f7b8f TH |
392 | } |
393 | #endif | |
237fead6 MH |
394 | |
395 | const struct file_operations ecryptfs_dir_fops = { | |
51a16a9c | 396 | .iterate_shared = ecryptfs_readdir, |
323ef68f | 397 | .read = generic_read_dir, |
c43f7b8f TH |
398 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
399 | #ifdef CONFIG_COMPAT | |
400 | .compat_ioctl = ecryptfs_compat_ioctl, | |
401 | #endif | |
6a480a78 AV |
402 | .open = ecryptfs_dir_open, |
403 | .release = ecryptfs_dir_release, | |
237fead6 | 404 | .fsync = ecryptfs_fsync, |
6a480a78 | 405 | .llseek = ecryptfs_dir_llseek, |
237fead6 MH |
406 | }; |
407 | ||
408 | const struct file_operations ecryptfs_main_fops = { | |
53a2731f | 409 | .llseek = generic_file_llseek, |
02797829 | 410 | .read_iter = ecryptfs_read_update_atime, |
8174202b | 411 | .write_iter = generic_file_write_iter, |
c43f7b8f TH |
412 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
413 | #ifdef CONFIG_COMPAT | |
414 | .compat_ioctl = ecryptfs_compat_ioctl, | |
415 | #endif | |
f0fe970d | 416 | .mmap = ecryptfs_mmap, |
237fead6 MH |
417 | .open = ecryptfs_open, |
418 | .flush = ecryptfs_flush, | |
419 | .release = ecryptfs_release, | |
420 | .fsync = ecryptfs_fsync, | |
421 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 422 | .splice_read = generic_file_splice_read, |
237fead6 | 423 | }; |