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, | |
47 | const struct iovec *iov, | |
48 | unsigned long nr_segs, loff_t pos) | |
49 | { | |
38a708d7 | 50 | ssize_t rc; |
68ac1234 | 51 | struct path lower; |
237fead6 MH |
52 | struct file *file = iocb->ki_filp; |
53 | ||
54 | rc = generic_file_aio_read(iocb, iov, nr_segs, pos); | |
55 | /* | |
56 | * Even though this is a async interface, we need to wait | |
57 | * for IO to finish to update atime | |
58 | */ | |
59 | if (-EIOCBQUEUED == rc) | |
60 | rc = wait_on_sync_kiocb(iocb); | |
61 | if (rc >= 0) { | |
68ac1234 AV |
62 | lower.dentry = ecryptfs_dentry_to_lower(file->f_path.dentry); |
63 | lower.mnt = ecryptfs_dentry_to_lower_mnt(file->f_path.dentry); | |
64 | touch_atime(&lower); | |
237fead6 MH |
65 | } |
66 | return rc; | |
67 | } | |
68 | ||
69 | struct ecryptfs_getdents_callback { | |
70 | void *dirent; | |
71 | struct dentry *dentry; | |
72 | filldir_t filldir; | |
237fead6 MH |
73 | int filldir_called; |
74 | int entries_written; | |
75 | }; | |
76 | ||
7d6c7045 | 77 | /* Inspired by generic filldir in fs/readdir.c */ |
237fead6 | 78 | static int |
addd65ad MH |
79 | ecryptfs_filldir(void *dirent, const char *lower_name, int lower_namelen, |
80 | loff_t offset, u64 ino, unsigned int d_type) | |
237fead6 | 81 | { |
237fead6 MH |
82 | struct ecryptfs_getdents_callback *buf = |
83 | (struct ecryptfs_getdents_callback *)dirent; | |
a8f12864 | 84 | size_t name_size; |
addd65ad | 85 | char *name; |
237fead6 | 86 | int rc; |
237fead6 | 87 | |
237fead6 | 88 | buf->filldir_called++; |
addd65ad MH |
89 | rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size, |
90 | buf->dentry, lower_name, | |
91 | lower_namelen); | |
92 | if (rc) { | |
93 | printk(KERN_ERR "%s: Error attempting to decode and decrypt " | |
94 | "filename [%s]; rc = [%d]\n", __func__, lower_name, | |
95 | rc); | |
237fead6 MH |
96 | goto out; |
97 | } | |
addd65ad MH |
98 | rc = buf->filldir(buf->dirent, name, name_size, offset, ino, d_type); |
99 | kfree(name); | |
237fead6 MH |
100 | if (rc >= 0) |
101 | buf->entries_written++; | |
102 | out: | |
103 | return rc; | |
104 | } | |
105 | ||
106 | /** | |
107 | * ecryptfs_readdir | |
addd65ad MH |
108 | * @file: The eCryptfs directory file |
109 | * @dirent: Directory entry handle | |
237fead6 MH |
110 | * @filldir: The filldir callback function |
111 | */ | |
112 | static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir) | |
113 | { | |
114 | int rc; | |
115 | struct file *lower_file; | |
116 | struct inode *inode; | |
117 | struct ecryptfs_getdents_callback buf; | |
118 | ||
119 | lower_file = ecryptfs_file_to_lower(file); | |
120 | lower_file->f_pos = file->f_pos; | |
bd243a4b | 121 | inode = file->f_path.dentry->d_inode; |
237fead6 MH |
122 | memset(&buf, 0, sizeof(buf)); |
123 | buf.dirent = dirent; | |
bd243a4b | 124 | buf.dentry = file->f_path.dentry; |
237fead6 | 125 | buf.filldir = filldir; |
237fead6 MH |
126 | buf.filldir_called = 0; |
127 | buf.entries_written = 0; | |
237fead6 | 128 | rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf); |
237fead6 | 129 | file->f_pos = lower_file->f_pos; |
7d6c7045 MH |
130 | if (rc < 0) |
131 | goto out; | |
132 | if (buf.filldir_called && !buf.entries_written) | |
133 | goto out; | |
237fead6 | 134 | if (rc >= 0) |
7d6c7045 MH |
135 | fsstack_copy_attr_atime(inode, |
136 | lower_file->f_path.dentry->d_inode); | |
137 | out: | |
237fead6 MH |
138 | return rc; |
139 | } | |
140 | ||
32001d6f TH |
141 | static void ecryptfs_vma_close(struct vm_area_struct *vma) |
142 | { | |
143 | filemap_write_and_wait(vma->vm_file->f_mapping); | |
144 | } | |
145 | ||
146 | static const struct vm_operations_struct ecryptfs_file_vm_ops = { | |
147 | .close = ecryptfs_vma_close, | |
148 | .fault = filemap_fault, | |
149 | }; | |
150 | ||
151 | static int ecryptfs_file_mmap(struct file *file, struct vm_area_struct *vma) | |
152 | { | |
153 | int rc; | |
154 | ||
155 | rc = generic_file_mmap(file, vma); | |
156 | if (!rc) | |
157 | vma->vm_ops = &ecryptfs_file_vm_ops; | |
158 | ||
159 | return rc; | |
160 | } | |
161 | ||
237fead6 MH |
162 | struct kmem_cache *ecryptfs_file_info_cache; |
163 | ||
e3ccaa97 TH |
164 | static int read_or_initialize_metadata(struct dentry *dentry) |
165 | { | |
166 | struct inode *inode = dentry->d_inode; | |
167 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; | |
168 | struct ecryptfs_crypt_stat *crypt_stat; | |
169 | int rc; | |
170 | ||
171 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
172 | mount_crypt_stat = &ecryptfs_superblock_to_private( | |
173 | inode->i_sb)->mount_crypt_stat; | |
174 | mutex_lock(&crypt_stat->cs_mutex); | |
175 | ||
176 | if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED && | |
177 | crypt_stat->flags & ECRYPTFS_KEY_VALID) { | |
178 | rc = 0; | |
179 | goto out; | |
180 | } | |
181 | ||
182 | rc = ecryptfs_read_metadata(dentry); | |
183 | if (!rc) | |
184 | goto out; | |
185 | ||
186 | if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) { | |
187 | crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED | |
188 | | ECRYPTFS_ENCRYPTED); | |
189 | rc = 0; | |
190 | goto out; | |
191 | } | |
192 | ||
193 | if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) && | |
194 | !i_size_read(ecryptfs_inode_to_lower(inode))) { | |
195 | rc = ecryptfs_initialize_file(dentry, inode); | |
196 | if (!rc) | |
197 | goto out; | |
198 | } | |
199 | ||
200 | rc = -EIO; | |
201 | out: | |
202 | mutex_unlock(&crypt_stat->cs_mutex); | |
203 | return rc; | |
204 | } | |
205 | ||
237fead6 MH |
206 | /** |
207 | * ecryptfs_open | |
208 | * @inode: inode speciying file to open | |
209 | * @file: Structure to return filled in | |
210 | * | |
211 | * Opens the file specified by inode. | |
212 | * | |
213 | * Returns zero on success; non-zero otherwise | |
214 | */ | |
215 | static int ecryptfs_open(struct inode *inode, struct file *file) | |
216 | { | |
217 | int rc = 0; | |
218 | struct ecryptfs_crypt_stat *crypt_stat = NULL; | |
219 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; | |
bd243a4b | 220 | struct dentry *ecryptfs_dentry = file->f_path.dentry; |
237fead6 MH |
221 | /* Private value of ecryptfs_dentry allocated in |
222 | * ecryptfs_lookup() */ | |
4aa25bcb | 223 | struct dentry *lower_dentry; |
237fead6 | 224 | struct ecryptfs_file_info *file_info; |
237fead6 | 225 | |
e77a56dd MH |
226 | mount_crypt_stat = &ecryptfs_superblock_to_private( |
227 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
228 | if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
229 | && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR) | |
230 | || (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC) | |
231 | || (file->f_flags & O_APPEND))) { | |
232 | printk(KERN_WARNING "Mount has encrypted view enabled; " | |
233 | "files may only be read\n"); | |
234 | rc = -EPERM; | |
235 | goto out; | |
236 | } | |
237fead6 | 237 | /* Released in ecryptfs_release or end of function if failure */ |
c3762229 | 238 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); |
237fead6 MH |
239 | ecryptfs_set_file_private(file, file_info); |
240 | if (!file_info) { | |
241 | ecryptfs_printk(KERN_ERR, | |
242 | "Error attempting to allocate memory\n"); | |
243 | rc = -ENOMEM; | |
244 | goto out; | |
245 | } | |
237fead6 MH |
246 | lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); |
247 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
237fead6 | 248 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 249 | if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) { |
237fead6 MH |
250 | ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n"); |
251 | /* Policy code enabled in future release */ | |
2ed92554 MH |
252 | crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED |
253 | | ECRYPTFS_ENCRYPTED); | |
237fead6 MH |
254 | } |
255 | mutex_unlock(&crypt_stat->cs_mutex); | |
3b06b3eb | 256 | rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode); |
27992890 RS |
257 | if (rc) { |
258 | printk(KERN_ERR "%s: Error attempting to initialize " | |
332ab16f | 259 | "the lower file for the dentry with name " |
27992890 RS |
260 | "[%s]; rc = [%d]\n", __func__, |
261 | ecryptfs_dentry->d_name.name, rc); | |
262 | goto out_free; | |
72b55fff | 263 | } |
0abe1169 RS |
264 | if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE) |
265 | == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) { | |
e27759d7 | 266 | rc = -EPERM; |
332ab16f | 267 | printk(KERN_WARNING "%s: Lower file is RO; eCryptfs " |
e27759d7 | 268 | "file must hence be opened RO\n", __func__); |
332ab16f | 269 | goto out_put; |
e27759d7 | 270 | } |
2ed92554 MH |
271 | ecryptfs_set_file_lower( |
272 | file, ecryptfs_inode_to_private(inode)->lower_file); | |
237fead6 MH |
273 | if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { |
274 | ecryptfs_printk(KERN_DEBUG, "This is a directory\n"); | |
2f9b12a3 | 275 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 276 | crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); |
2f9b12a3 | 277 | mutex_unlock(&crypt_stat->cs_mutex); |
237fead6 MH |
278 | rc = 0; |
279 | goto out; | |
280 | } | |
e3ccaa97 TH |
281 | rc = read_or_initialize_metadata(ecryptfs_dentry); |
282 | if (rc) | |
283 | goto out_put; | |
888d57bb JP |
284 | ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = " |
285 | "[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino, | |
286 | (unsigned long long)i_size_read(inode)); | |
237fead6 | 287 | goto out; |
332ab16f TH |
288 | out_put: |
289 | ecryptfs_put_lower_file(inode); | |
2ed92554 | 290 | out_free: |
237fead6 MH |
291 | kmem_cache_free(ecryptfs_file_info_cache, |
292 | ecryptfs_file_to_private(file)); | |
293 | out: | |
294 | return rc; | |
295 | } | |
296 | ||
297 | static int ecryptfs_flush(struct file *file, fl_owner_t td) | |
298 | { | |
332ab16f TH |
299 | return file->f_mode & FMODE_WRITE |
300 | ? filemap_write_and_wait(file->f_mapping) : 0; | |
237fead6 MH |
301 | } |
302 | ||
303 | static int ecryptfs_release(struct inode *inode, struct file *file) | |
304 | { | |
332ab16f | 305 | ecryptfs_put_lower_file(inode); |
2ed92554 MH |
306 | kmem_cache_free(ecryptfs_file_info_cache, |
307 | ecryptfs_file_to_private(file)); | |
308 | return 0; | |
237fead6 MH |
309 | } |
310 | ||
311 | static int | |
02c24a82 | 312 | ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
237fead6 | 313 | { |
57db4e8d TL |
314 | int rc = 0; |
315 | ||
02c24a82 | 316 | rc = generic_file_fsync(file, start, end, datasync); |
57db4e8d TL |
317 | if (rc) |
318 | goto out; | |
02c24a82 JB |
319 | rc = vfs_fsync_range(ecryptfs_file_to_lower(file), start, end, |
320 | datasync); | |
57db4e8d TL |
321 | out: |
322 | return rc; | |
237fead6 MH |
323 | } |
324 | ||
325 | static int ecryptfs_fasync(int fd, struct file *file, int flag) | |
326 | { | |
327 | int rc = 0; | |
328 | struct file *lower_file = NULL; | |
329 | ||
330 | lower_file = ecryptfs_file_to_lower(file); | |
331 | if (lower_file->f_op && lower_file->f_op->fasync) | |
332 | rc = lower_file->f_op->fasync(fd, lower_file, flag); | |
333 | return rc; | |
334 | } | |
335 | ||
c43f7b8f TH |
336 | static long |
337 | ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
338 | { | |
339 | struct file *lower_file = NULL; | |
340 | long rc = -ENOTTY; | |
341 | ||
342 | if (ecryptfs_file_to_private(file)) | |
343 | lower_file = ecryptfs_file_to_lower(file); | |
344 | if (lower_file && lower_file->f_op && lower_file->f_op->unlocked_ioctl) | |
345 | rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); | |
346 | return rc; | |
347 | } | |
348 | ||
349 | #ifdef CONFIG_COMPAT | |
350 | static long | |
351 | ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
352 | { | |
353 | struct file *lower_file = NULL; | |
354 | long rc = -ENOIOCTLCMD; | |
355 | ||
356 | if (ecryptfs_file_to_private(file)) | |
357 | lower_file = ecryptfs_file_to_lower(file); | |
358 | if (lower_file && lower_file->f_op && lower_file->f_op->compat_ioctl) | |
359 | rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg); | |
360 | return rc; | |
361 | } | |
362 | #endif | |
237fead6 MH |
363 | |
364 | const struct file_operations ecryptfs_dir_fops = { | |
365 | .readdir = ecryptfs_readdir, | |
323ef68f | 366 | .read = generic_read_dir, |
c43f7b8f TH |
367 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
368 | #ifdef CONFIG_COMPAT | |
369 | .compat_ioctl = ecryptfs_compat_ioctl, | |
370 | #endif | |
237fead6 MH |
371 | .open = ecryptfs_open, |
372 | .flush = ecryptfs_flush, | |
373 | .release = ecryptfs_release, | |
374 | .fsync = ecryptfs_fsync, | |
375 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 376 | .splice_read = generic_file_splice_read, |
6038f373 | 377 | .llseek = default_llseek, |
237fead6 MH |
378 | }; |
379 | ||
380 | const struct file_operations ecryptfs_main_fops = { | |
53a2731f | 381 | .llseek = generic_file_llseek, |
237fead6 MH |
382 | .read = do_sync_read, |
383 | .aio_read = ecryptfs_read_update_atime, | |
384 | .write = do_sync_write, | |
385 | .aio_write = generic_file_aio_write, | |
386 | .readdir = ecryptfs_readdir, | |
c43f7b8f TH |
387 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
388 | #ifdef CONFIG_COMPAT | |
389 | .compat_ioctl = ecryptfs_compat_ioctl, | |
390 | #endif | |
32001d6f | 391 | .mmap = ecryptfs_file_mmap, |
237fead6 MH |
392 | .open = ecryptfs_open, |
393 | .flush = ecryptfs_flush, | |
394 | .release = ecryptfs_release, | |
395 | .fsync = ecryptfs_fsync, | |
396 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 397 | .splice_read = generic_file_splice_read, |
237fead6 | 398 | }; |