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> | |
28 | #include <linux/mount.h> | |
29 | #include <linux/pagemap.h> | |
30 | #include <linux/security.h> | |
237fead6 | 31 | #include <linux/compat.h> |
0cc72dc7 | 32 | #include <linux/fs_stack.h> |
dda6445e | 33 | #include <linux/smp_lock.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 | { | |
50 | int rc; | |
51 | struct dentry *lower_dentry; | |
52 | struct vfsmount *lower_vfsmount; | |
53 | struct file *file = iocb->ki_filp; | |
54 | ||
55 | rc = generic_file_aio_read(iocb, iov, nr_segs, pos); | |
56 | /* | |
57 | * Even though this is a async interface, we need to wait | |
58 | * for IO to finish to update atime | |
59 | */ | |
60 | if (-EIOCBQUEUED == rc) | |
61 | rc = wait_on_sync_kiocb(iocb); | |
62 | if (rc >= 0) { | |
bd243a4b JJS |
63 | lower_dentry = ecryptfs_dentry_to_lower(file->f_path.dentry); |
64 | lower_vfsmount = ecryptfs_dentry_to_lower_mnt(file->f_path.dentry); | |
237fead6 MH |
65 | touch_atime(lower_vfsmount, lower_dentry); |
66 | } | |
67 | return rc; | |
68 | } | |
69 | ||
70 | struct ecryptfs_getdents_callback { | |
71 | void *dirent; | |
72 | struct dentry *dentry; | |
73 | filldir_t filldir; | |
237fead6 MH |
74 | int filldir_called; |
75 | int entries_written; | |
76 | }; | |
77 | ||
7d6c7045 | 78 | /* Inspired by generic filldir in fs/readdir.c */ |
237fead6 MH |
79 | static int |
80 | ecryptfs_filldir(void *dirent, const char *name, int namelen, loff_t offset, | |
81 | u64 ino, unsigned int d_type) | |
82 | { | |
83 | struct ecryptfs_crypt_stat *crypt_stat; | |
84 | struct ecryptfs_getdents_callback *buf = | |
85 | (struct ecryptfs_getdents_callback *)dirent; | |
86 | int rc; | |
87 | int decoded_length; | |
88 | char *decoded_name; | |
89 | ||
90 | crypt_stat = ecryptfs_dentry_to_private(buf->dentry)->crypt_stat; | |
91 | buf->filldir_called++; | |
92 | decoded_length = ecryptfs_decode_filename(crypt_stat, name, namelen, | |
93 | &decoded_name); | |
94 | if (decoded_length < 0) { | |
95 | rc = decoded_length; | |
96 | goto out; | |
97 | } | |
98 | rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset, | |
99 | ino, d_type); | |
100 | kfree(decoded_name); | |
101 | if (rc >= 0) | |
102 | buf->entries_written++; | |
103 | out: | |
104 | return rc; | |
105 | } | |
106 | ||
107 | /** | |
108 | * ecryptfs_readdir | |
109 | * @file: The ecryptfs file struct | |
110 | * @dirent: Directory entry | |
111 | * @filldir: The filldir callback function | |
112 | */ | |
113 | static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir) | |
114 | { | |
115 | int rc; | |
116 | struct file *lower_file; | |
117 | struct inode *inode; | |
118 | struct ecryptfs_getdents_callback buf; | |
119 | ||
120 | lower_file = ecryptfs_file_to_lower(file); | |
121 | lower_file->f_pos = file->f_pos; | |
bd243a4b | 122 | inode = file->f_path.dentry->d_inode; |
237fead6 MH |
123 | memset(&buf, 0, sizeof(buf)); |
124 | buf.dirent = dirent; | |
bd243a4b | 125 | buf.dentry = file->f_path.dentry; |
237fead6 | 126 | buf.filldir = filldir; |
237fead6 MH |
127 | buf.filldir_called = 0; |
128 | buf.entries_written = 0; | |
237fead6 | 129 | rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf); |
237fead6 | 130 | file->f_pos = lower_file->f_pos; |
7d6c7045 MH |
131 | if (rc < 0) |
132 | goto out; | |
133 | if (buf.filldir_called && !buf.entries_written) | |
134 | goto out; | |
237fead6 | 135 | if (rc >= 0) |
7d6c7045 MH |
136 | fsstack_copy_attr_atime(inode, |
137 | lower_file->f_path.dentry->d_inode); | |
138 | out: | |
237fead6 MH |
139 | return rc; |
140 | } | |
141 | ||
142 | struct kmem_cache *ecryptfs_file_info_cache; | |
143 | ||
144 | /** | |
145 | * ecryptfs_open | |
146 | * @inode: inode speciying file to open | |
147 | * @file: Structure to return filled in | |
148 | * | |
149 | * Opens the file specified by inode. | |
150 | * | |
151 | * Returns zero on success; non-zero otherwise | |
152 | */ | |
153 | static int ecryptfs_open(struct inode *inode, struct file *file) | |
154 | { | |
155 | int rc = 0; | |
156 | struct ecryptfs_crypt_stat *crypt_stat = NULL; | |
157 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; | |
bd243a4b | 158 | struct dentry *ecryptfs_dentry = file->f_path.dentry; |
237fead6 MH |
159 | /* Private value of ecryptfs_dentry allocated in |
160 | * ecryptfs_lookup() */ | |
161 | struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); | |
237fead6 | 162 | struct ecryptfs_file_info *file_info; |
237fead6 | 163 | |
e77a56dd MH |
164 | mount_crypt_stat = &ecryptfs_superblock_to_private( |
165 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
166 | if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
167 | && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR) | |
168 | || (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC) | |
169 | || (file->f_flags & O_APPEND))) { | |
170 | printk(KERN_WARNING "Mount has encrypted view enabled; " | |
171 | "files may only be read\n"); | |
172 | rc = -EPERM; | |
173 | goto out; | |
174 | } | |
237fead6 | 175 | /* Released in ecryptfs_release or end of function if failure */ |
c3762229 | 176 | file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL); |
237fead6 MH |
177 | ecryptfs_set_file_private(file, file_info); |
178 | if (!file_info) { | |
179 | ecryptfs_printk(KERN_ERR, | |
180 | "Error attempting to allocate memory\n"); | |
181 | rc = -ENOMEM; | |
182 | goto out; | |
183 | } | |
237fead6 MH |
184 | lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); |
185 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
237fead6 | 186 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 187 | if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) { |
237fead6 MH |
188 | ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n"); |
189 | /* Policy code enabled in future release */ | |
2ed92554 MH |
190 | crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED |
191 | | ECRYPTFS_ENCRYPTED); | |
237fead6 MH |
192 | } |
193 | mutex_unlock(&crypt_stat->cs_mutex); | |
746f1e55 MH |
194 | if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY) |
195 | && !(file->f_flags & O_RDONLY)) { | |
196 | rc = -EPERM; | |
197 | printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs " | |
198 | "file must hence be opened RO\n", __func__); | |
199 | goto out; | |
200 | } | |
72b55fff | 201 | if (!ecryptfs_inode_to_private(inode)->lower_file) { |
72b55fff MH |
202 | rc = ecryptfs_init_persistent_file(ecryptfs_dentry); |
203 | if (rc) { | |
204 | printk(KERN_ERR "%s: Error attempting to initialize " | |
205 | "the persistent file for the dentry with name " | |
206 | "[%s]; rc = [%d]\n", __func__, | |
207 | ecryptfs_dentry->d_name.name, rc); | |
208 | goto out; | |
209 | } | |
210 | } | |
2ed92554 MH |
211 | ecryptfs_set_file_lower( |
212 | file, ecryptfs_inode_to_private(inode)->lower_file); | |
237fead6 MH |
213 | if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { |
214 | ecryptfs_printk(KERN_DEBUG, "This is a directory\n"); | |
2f9b12a3 | 215 | mutex_lock(&crypt_stat->cs_mutex); |
e2bd99ec | 216 | crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); |
2f9b12a3 | 217 | mutex_unlock(&crypt_stat->cs_mutex); |
237fead6 MH |
218 | rc = 0; |
219 | goto out; | |
220 | } | |
221 | mutex_lock(&crypt_stat->cs_mutex); | |
e2bd99ec MH |
222 | if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED) |
223 | || !(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { | |
d7cdc5fe | 224 | rc = ecryptfs_read_metadata(ecryptfs_dentry); |
237fead6 MH |
225 | if (rc) { |
226 | ecryptfs_printk(KERN_DEBUG, | |
227 | "Valid headers not found\n"); | |
228 | if (!(mount_crypt_stat->flags | |
229 | & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) { | |
230 | rc = -EIO; | |
25bd8174 | 231 | printk(KERN_WARNING "Either the lower file " |
237fead6 | 232 | "is not in a valid eCryptfs format, " |
25bd8174 MH |
233 | "or the key could not be retrieved. " |
234 | "Plaintext passthrough mode is not " | |
237fead6 MH |
235 | "enabled; returning -EIO\n"); |
236 | mutex_unlock(&crypt_stat->cs_mutex); | |
2ed92554 | 237 | goto out_free; |
237fead6 | 238 | } |
237fead6 | 239 | rc = 0; |
e2bd99ec | 240 | crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); |
237fead6 MH |
241 | mutex_unlock(&crypt_stat->cs_mutex); |
242 | goto out; | |
243 | } | |
244 | } | |
245 | mutex_unlock(&crypt_stat->cs_mutex); | |
246 | ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] " | |
247 | "size: [0x%.16x]\n", inode, inode->i_ino, | |
248 | i_size_read(inode)); | |
237fead6 | 249 | goto out; |
2ed92554 | 250 | out_free: |
237fead6 MH |
251 | kmem_cache_free(ecryptfs_file_info_cache, |
252 | ecryptfs_file_to_private(file)); | |
253 | out: | |
254 | return rc; | |
255 | } | |
256 | ||
257 | static int ecryptfs_flush(struct file *file, fl_owner_t td) | |
258 | { | |
259 | int rc = 0; | |
260 | struct file *lower_file = NULL; | |
261 | ||
262 | lower_file = ecryptfs_file_to_lower(file); | |
263 | if (lower_file->f_op && lower_file->f_op->flush) | |
264 | rc = lower_file->f_op->flush(lower_file, td); | |
265 | return rc; | |
266 | } | |
267 | ||
268 | static int ecryptfs_release(struct inode *inode, struct file *file) | |
269 | { | |
2ed92554 MH |
270 | kmem_cache_free(ecryptfs_file_info_cache, |
271 | ecryptfs_file_to_private(file)); | |
272 | return 0; | |
237fead6 MH |
273 | } |
274 | ||
275 | static int | |
276 | ecryptfs_fsync(struct file *file, struct dentry *dentry, int datasync) | |
277 | { | |
278 | struct file *lower_file = ecryptfs_file_to_lower(file); | |
279 | struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); | |
280 | struct inode *lower_inode = lower_dentry->d_inode; | |
281 | int rc = -EINVAL; | |
282 | ||
283 | if (lower_inode->i_fop->fsync) { | |
284 | mutex_lock(&lower_inode->i_mutex); | |
285 | rc = lower_inode->i_fop->fsync(lower_file, lower_dentry, | |
286 | datasync); | |
287 | mutex_unlock(&lower_inode->i_mutex); | |
288 | } | |
289 | return rc; | |
290 | } | |
291 | ||
292 | static int ecryptfs_fasync(int fd, struct file *file, int flag) | |
293 | { | |
294 | int rc = 0; | |
295 | struct file *lower_file = NULL; | |
296 | ||
dda6445e | 297 | lock_kernel(); |
237fead6 MH |
298 | lower_file = ecryptfs_file_to_lower(file); |
299 | if (lower_file->f_op && lower_file->f_op->fasync) | |
300 | rc = lower_file->f_op->fasync(fd, lower_file, flag); | |
dda6445e | 301 | unlock_kernel(); |
237fead6 MH |
302 | return rc; |
303 | } | |
304 | ||
237fead6 MH |
305 | static int ecryptfs_ioctl(struct inode *inode, struct file *file, |
306 | unsigned int cmd, unsigned long arg); | |
307 | ||
308 | const struct file_operations ecryptfs_dir_fops = { | |
309 | .readdir = ecryptfs_readdir, | |
310 | .ioctl = ecryptfs_ioctl, | |
311 | .mmap = generic_file_mmap, | |
312 | .open = ecryptfs_open, | |
313 | .flush = ecryptfs_flush, | |
314 | .release = ecryptfs_release, | |
315 | .fsync = ecryptfs_fsync, | |
316 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 317 | .splice_read = generic_file_splice_read, |
237fead6 MH |
318 | }; |
319 | ||
320 | const struct file_operations ecryptfs_main_fops = { | |
53a2731f | 321 | .llseek = generic_file_llseek, |
237fead6 MH |
322 | .read = do_sync_read, |
323 | .aio_read = ecryptfs_read_update_atime, | |
324 | .write = do_sync_write, | |
325 | .aio_write = generic_file_aio_write, | |
326 | .readdir = ecryptfs_readdir, | |
327 | .ioctl = ecryptfs_ioctl, | |
328 | .mmap = generic_file_mmap, | |
329 | .open = ecryptfs_open, | |
330 | .flush = ecryptfs_flush, | |
331 | .release = ecryptfs_release, | |
332 | .fsync = ecryptfs_fsync, | |
333 | .fasync = ecryptfs_fasync, | |
e9f6a99c | 334 | .splice_read = generic_file_splice_read, |
237fead6 MH |
335 | }; |
336 | ||
337 | static int | |
338 | ecryptfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
339 | unsigned long arg) | |
340 | { | |
341 | int rc = 0; | |
342 | struct file *lower_file = NULL; | |
343 | ||
344 | if (ecryptfs_file_to_private(file)) | |
345 | lower_file = ecryptfs_file_to_lower(file); | |
346 | if (lower_file && lower_file->f_op && lower_file->f_op->ioctl) | |
347 | rc = lower_file->f_op->ioctl(ecryptfs_inode_to_lower(inode), | |
348 | lower_file, cmd, arg); | |
349 | else | |
350 | rc = -ENOTTY; | |
351 | return rc; | |
352 | } |