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> |
a27bb332 | 34 | #include <linux/aio.h> |
237fead6 MH |
35 | #include "ecryptfs_kernel.h" |
36 | ||
237fead6 MH |
37 | /** |
38 | * ecryptfs_read_update_atime | |
39 | * | |
40 | * generic_file_read updates the atime of upper layer inode. But, it | |
41 | * doesn't give us a chance to update the atime of the lower layer | |
42 | * inode. This function is a wrapper to generic_file_read. It | |
43 | * updates the atime of the lower level inode if generic_file_read | |
44 | * returns without any errors. This is to be used only for file reads. | |
45 | * The function to be used for directory reads is ecryptfs_read. | |
46 | */ | |
47 | static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb, | |
02797829 | 48 | struct iov_iter *to) |
237fead6 | 49 | { |
38a708d7 | 50 | ssize_t rc; |
cc18ec3c | 51 | struct path *path; |
237fead6 MH |
52 | struct file *file = iocb->ki_filp; |
53 | ||
02797829 | 54 | rc = generic_file_read_iter(iocb, to); |
237fead6 MH |
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) { | |
cc18ec3c MW |
62 | path = ecryptfs_dentry_to_lower_path(file->f_path.dentry); |
63 | touch_atime(path); | |
237fead6 MH |
64 | } |
65 | return rc; | |
66 | } | |
67 | ||
68 | struct ecryptfs_getdents_callback { | |
5c0ba4e0 | 69 | struct dir_context ctx; |
2de5f059 | 70 | struct dir_context *caller; |
0747fdb2 | 71 | struct super_block *sb; |
237fead6 MH |
72 | int filldir_called; |
73 | int entries_written; | |
74 | }; | |
75 | ||
7d6c7045 | 76 | /* Inspired by generic filldir in fs/readdir.c */ |
237fead6 | 77 | static int |
addd65ad MH |
78 | ecryptfs_filldir(void *dirent, const char *lower_name, int lower_namelen, |
79 | loff_t offset, u64 ino, unsigned int d_type) | |
237fead6 | 80 | { |
237fead6 MH |
81 | struct ecryptfs_getdents_callback *buf = |
82 | (struct ecryptfs_getdents_callback *)dirent; | |
a8f12864 | 83 | size_t name_size; |
addd65ad | 84 | char *name; |
237fead6 | 85 | int rc; |
237fead6 | 86 | |
237fead6 | 87 | buf->filldir_called++; |
addd65ad | 88 | rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size, |
0747fdb2 | 89 | buf->sb, lower_name, |
addd65ad MH |
90 | lower_namelen); |
91 | if (rc) { | |
92 | printk(KERN_ERR "%s: Error attempting to decode and decrypt " | |
93 | "filename [%s]; rc = [%d]\n", __func__, lower_name, | |
94 | rc); | |
237fead6 MH |
95 | goto out; |
96 | } | |
2de5f059 AV |
97 | buf->caller->pos = buf->ctx.pos; |
98 | rc = !dir_emit(buf->caller, name, name_size, ino, d_type); | |
addd65ad | 99 | kfree(name); |
2de5f059 | 100 | if (!rc) |
237fead6 MH |
101 | buf->entries_written++; |
102 | out: | |
103 | return rc; | |
104 | } | |
105 | ||
106 | /** | |
107 | * ecryptfs_readdir | |
addd65ad | 108 | * @file: The eCryptfs directory file |
2de5f059 | 109 | * @ctx: The actor to feed the entries to |
237fead6 | 110 | */ |
2de5f059 | 111 | static int ecryptfs_readdir(struct file *file, struct dir_context *ctx) |
237fead6 MH |
112 | { |
113 | int rc; | |
114 | struct file *lower_file; | |
0747fdb2 | 115 | struct inode *inode = file_inode(file); |
2de5f059 AV |
116 | struct ecryptfs_getdents_callback buf = { |
117 | .ctx.actor = ecryptfs_filldir, | |
118 | .caller = ctx, | |
0747fdb2 | 119 | .sb = inode->i_sb, |
2de5f059 | 120 | }; |
237fead6 | 121 | lower_file = ecryptfs_file_to_lower(file); |
2de5f059 | 122 | lower_file->f_pos = ctx->pos; |
5c0ba4e0 | 123 | rc = iterate_dir(lower_file, &buf.ctx); |
2de5f059 | 124 | ctx->pos = buf.ctx.pos; |
7d6c7045 MH |
125 | if (rc < 0) |
126 | goto out; | |
127 | if (buf.filldir_called && !buf.entries_written) | |
128 | goto out; | |
237fead6 | 129 | if (rc >= 0) |
7d6c7045 | 130 | fsstack_copy_attr_atime(inode, |
496ad9aa | 131 | file_inode(lower_file)); |
7d6c7045 | 132 | out: |
237fead6 MH |
133 | return rc; |
134 | } | |
135 | ||
136 | struct kmem_cache *ecryptfs_file_info_cache; | |
137 | ||
e3ccaa97 TH |
138 | static int read_or_initialize_metadata(struct dentry *dentry) |
139 | { | |
140 | struct inode *inode = dentry->d_inode; | |
141 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; | |
142 | struct ecryptfs_crypt_stat *crypt_stat; | |
143 | int rc; | |
144 | ||
145 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
146 | mount_crypt_stat = &ecryptfs_superblock_to_private( | |
147 | inode->i_sb)->mount_crypt_stat; | |
148 | mutex_lock(&crypt_stat->cs_mutex); | |
149 | ||
150 | if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED && | |
151 | crypt_stat->flags & ECRYPTFS_KEY_VALID) { | |
152 | rc = 0; | |
153 | goto out; | |
154 | } | |
155 | ||
156 | rc = ecryptfs_read_metadata(dentry); | |
157 | if (!rc) | |
158 | goto out; | |
159 | ||
160 | if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) { | |
161 | crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED | |
162 | | ECRYPTFS_ENCRYPTED); | |
163 | rc = 0; | |
164 | goto out; | |
165 | } | |
166 | ||
167 | if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) && | |
168 | !i_size_read(ecryptfs_inode_to_lower(inode))) { | |
169 | rc = ecryptfs_initialize_file(dentry, inode); | |
170 | if (!rc) | |
171 | goto out; | |
172 | } | |
173 | ||
174 | rc = -EIO; | |
175 | out: | |
176 | mutex_unlock(&crypt_stat->cs_mutex); | |
177 | return rc; | |
178 | } | |
179 | ||
237fead6 MH |
180 | /** |
181 | * ecryptfs_open | |
182 | * @inode: inode speciying file to open | |
183 | * @file: Structure to return filled in | |
184 | * | |
185 | * Opens the file specified by inode. | |
186 | * | |
187 | * Returns zero on success; non-zero otherwise | |
188 | */ | |
189 | static int ecryptfs_open(struct inode *inode, struct file *file) | |
190 | { | |
191 | int rc = 0; | |
192 | struct ecryptfs_crypt_stat *crypt_stat = NULL; | |
193 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; | |
bd243a4b | 194 | struct dentry *ecryptfs_dentry = file->f_path.dentry; |
237fead6 MH |
195 | /* Private value of ecryptfs_dentry allocated in |
196 | * ecryptfs_lookup() */ | |
237fead6 | 197 | struct ecryptfs_file_info *file_info; |
237fead6 | 198 | |
e77a56dd MH |
199 | mount_crypt_stat = &ecryptfs_superblock_to_private( |
200 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
201 | if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
202 | && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR) | |
203 | || (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC) | |
204 | || (file->f_flags & O_APPEND))) { | |
205 | printk(KERN_WARNING "Mount has encrypted view enabled; " | |
206 | "files may only be read\n"); | |
207 | rc = -EPERM; | |
208 | goto out; | |
209 | } | |
237fead6 | 210 | /* Released in ecryptfs_release or end of function if failure */ |
c3762229 | 211 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); |
237fead6 MH |
212 | ecryptfs_set_file_private(file, file_info); |
213 | if (!file_info) { | |
214 | ecryptfs_printk(KERN_ERR, | |
215 | "Error attempting to allocate memory\n"); | |
216 | rc = -ENOMEM; | |
217 | goto out; | |
218 | } | |
237fead6 | 219 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; |
237fead6 | 220 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 221 | if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) { |
237fead6 MH |
222 | ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n"); |
223 | /* Policy code enabled in future release */ | |
2ed92554 MH |
224 | crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED |
225 | | ECRYPTFS_ENCRYPTED); | |
237fead6 MH |
226 | } |
227 | mutex_unlock(&crypt_stat->cs_mutex); | |
3b06b3eb | 228 | rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode); |
27992890 RS |
229 | if (rc) { |
230 | printk(KERN_ERR "%s: Error attempting to initialize " | |
332ab16f | 231 | "the lower file for the dentry with name " |
27992890 RS |
232 | "[%s]; rc = [%d]\n", __func__, |
233 | ecryptfs_dentry->d_name.name, rc); | |
234 | goto out_free; | |
72b55fff | 235 | } |
0abe1169 RS |
236 | if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE) |
237 | == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) { | |
e27759d7 | 238 | rc = -EPERM; |
332ab16f | 239 | printk(KERN_WARNING "%s: Lower file is RO; eCryptfs " |
e27759d7 | 240 | "file must hence be opened RO\n", __func__); |
332ab16f | 241 | goto out_put; |
e27759d7 | 242 | } |
2ed92554 MH |
243 | ecryptfs_set_file_lower( |
244 | file, ecryptfs_inode_to_private(inode)->lower_file); | |
237fead6 MH |
245 | if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { |
246 | ecryptfs_printk(KERN_DEBUG, "This is a directory\n"); | |
2f9b12a3 | 247 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 248 | crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); |
2f9b12a3 | 249 | mutex_unlock(&crypt_stat->cs_mutex); |
237fead6 MH |
250 | rc = 0; |
251 | goto out; | |
252 | } | |
e3ccaa97 TH |
253 | rc = read_or_initialize_metadata(ecryptfs_dentry); |
254 | if (rc) | |
255 | goto out_put; | |
888d57bb JP |
256 | ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = " |
257 | "[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino, | |
258 | (unsigned long long)i_size_read(inode)); | |
237fead6 | 259 | goto out; |
332ab16f TH |
260 | out_put: |
261 | ecryptfs_put_lower_file(inode); | |
2ed92554 | 262 | out_free: |
237fead6 MH |
263 | kmem_cache_free(ecryptfs_file_info_cache, |
264 | ecryptfs_file_to_private(file)); | |
265 | out: | |
266 | return rc; | |
267 | } | |
268 | ||
269 | static int ecryptfs_flush(struct file *file, fl_owner_t td) | |
270 | { | |
64e6651d TH |
271 | struct file *lower_file = ecryptfs_file_to_lower(file); |
272 | ||
72c2d531 | 273 | if (lower_file->f_op->flush) { |
64e6651d TH |
274 | filemap_write_and_wait(file->f_mapping); |
275 | return lower_file->f_op->flush(lower_file, td); | |
276 | } | |
277 | ||
278 | return 0; | |
237fead6 MH |
279 | } |
280 | ||
281 | static int ecryptfs_release(struct inode *inode, struct file *file) | |
282 | { | |
332ab16f | 283 | ecryptfs_put_lower_file(inode); |
2ed92554 MH |
284 | kmem_cache_free(ecryptfs_file_info_cache, |
285 | ecryptfs_file_to_private(file)); | |
286 | return 0; | |
237fead6 MH |
287 | } |
288 | ||
289 | static int | |
02c24a82 | 290 | ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
237fead6 | 291 | { |
bc5abcf7 TH |
292 | int rc; |
293 | ||
294 | rc = filemap_write_and_wait(file->f_mapping); | |
295 | if (rc) | |
296 | return rc; | |
297 | ||
821f7494 | 298 | return vfs_fsync(ecryptfs_file_to_lower(file), datasync); |
237fead6 MH |
299 | } |
300 | ||
301 | static int ecryptfs_fasync(int fd, struct file *file, int flag) | |
302 | { | |
303 | int rc = 0; | |
304 | struct file *lower_file = NULL; | |
305 | ||
306 | lower_file = ecryptfs_file_to_lower(file); | |
72c2d531 | 307 | if (lower_file->f_op->fasync) |
237fead6 MH |
308 | rc = lower_file->f_op->fasync(fd, lower_file, flag); |
309 | return rc; | |
310 | } | |
311 | ||
c43f7b8f TH |
312 | static long |
313 | ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
314 | { | |
2000f5be | 315 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
316 | long rc = -ENOTTY; |
317 | ||
bdd35366 | 318 | if (lower_file->f_op->unlocked_ioctl) |
c43f7b8f TH |
319 | rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); |
320 | return rc; | |
321 | } | |
322 | ||
323 | #ifdef CONFIG_COMPAT | |
324 | static long | |
325 | ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
326 | { | |
2000f5be | 327 | struct file *lower_file = ecryptfs_file_to_lower(file); |
c43f7b8f TH |
328 | long rc = -ENOIOCTLCMD; |
329 | ||
72c2d531 | 330 | if (lower_file->f_op && lower_file->f_op->compat_ioctl) |
c43f7b8f TH |
331 | rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg); |
332 | return rc; | |
333 | } | |
334 | #endif | |
237fead6 MH |
335 | |
336 | const struct file_operations ecryptfs_dir_fops = { | |
2de5f059 | 337 | .iterate = ecryptfs_readdir, |
323ef68f | 338 | .read = generic_read_dir, |
c43f7b8f TH |
339 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
340 | #ifdef CONFIG_COMPAT | |
341 | .compat_ioctl = ecryptfs_compat_ioctl, | |
342 | #endif | |
237fead6 MH |
343 | .open = ecryptfs_open, |
344 | .flush = ecryptfs_flush, | |
345 | .release = ecryptfs_release, | |
346 | .fsync = ecryptfs_fsync, | |
347 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 348 | .splice_read = generic_file_splice_read, |
6038f373 | 349 | .llseek = default_llseek, |
237fead6 MH |
350 | }; |
351 | ||
352 | const struct file_operations ecryptfs_main_fops = { | |
53a2731f | 353 | .llseek = generic_file_llseek, |
02797829 AV |
354 | .read = new_sync_read, |
355 | .read_iter = ecryptfs_read_update_atime, | |
8174202b AV |
356 | .write = new_sync_write, |
357 | .write_iter = generic_file_write_iter, | |
2de5f059 | 358 | .iterate = ecryptfs_readdir, |
c43f7b8f TH |
359 | .unlocked_ioctl = ecryptfs_unlocked_ioctl, |
360 | #ifdef CONFIG_COMPAT | |
361 | .compat_ioctl = ecryptfs_compat_ioctl, | |
362 | #endif | |
821f7494 | 363 | .mmap = generic_file_mmap, |
237fead6 MH |
364 | .open = ecryptfs_open, |
365 | .flush = ecryptfs_flush, | |
366 | .release = ecryptfs_release, | |
367 | .fsync = ecryptfs_fsync, | |
368 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 369 | .splice_read = generic_file_splice_read, |
237fead6 | 370 | }; |