blob: db0fad3269c0395f230c39cc0fcd6c9975f6d633 [file] [log] [blame]
Michael Halcrow237fead2006-10-04 02:16:22 -07001/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08006 * Copyright (C) 2004-2007 International Business Machines Corp.
Michael Halcrow237fead2006-10-04 02:16:22 -07007 * 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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070029#include <linux/mount.h>
30#include <linux/pagemap.h>
31#include <linux/security.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070032#include <linux/compat.h>
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -080033#include <linux/fs_stack.h>
Kent Overstreeta27bb332013-05-07 16:19:08 -070034#include <linux/aio.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070035#include "ecryptfs_kernel.h"
36
37/**
Michael Halcrow237fead2006-10-04 02:16:22 -070038 * 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 */
47static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
Al Viro02797822014-04-02 14:40:38 -040048 struct iov_iter *to)
Michael Halcrow237fead2006-10-04 02:16:22 -070049{
Edward Shishkin38a708d2010-10-30 00:11:50 +020050 ssize_t rc;
Matthew Wilcoxcc18ec32013-06-15 07:55:59 -040051 struct path *path;
Michael Halcrow237fead2006-10-04 02:16:22 -070052 struct file *file = iocb->ki_filp;
53
Al Viro02797822014-04-02 14:40:38 -040054 rc = generic_file_read_iter(iocb, to);
Michael Halcrow237fead2006-10-04 02:16:22 -070055 /*
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) {
Matthew Wilcoxcc18ec32013-06-15 07:55:59 -040062 path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);
63 touch_atime(path);
Michael Halcrow237fead2006-10-04 02:16:22 -070064 }
65 return rc;
66}
67
68struct ecryptfs_getdents_callback {
Al Viro5c0ba4e2013-05-15 13:52:59 -040069 struct dir_context ctx;
Al Viro2de5f052013-05-22 21:23:40 -040070 struct dir_context *caller;
Al Viro0747fdb2013-06-16 20:05:38 +040071 struct super_block *sb;
Michael Halcrow237fead2006-10-04 02:16:22 -070072 int filldir_called;
73 int entries_written;
74};
75
Michael Halcrow7d6c7042008-10-15 22:02:49 -070076/* Inspired by generic filldir in fs/readdir.c */
Michael Halcrow237fead2006-10-04 02:16:22 -070077static int
Michael Halcrowaddd65ad2009-01-06 14:42:00 -080078ecryptfs_filldir(void *dirent, const char *lower_name, int lower_namelen,
79 loff_t offset, u64 ino, unsigned int d_type)
Michael Halcrow237fead2006-10-04 02:16:22 -070080{
Michael Halcrow237fead2006-10-04 02:16:22 -070081 struct ecryptfs_getdents_callback *buf =
82 (struct ecryptfs_getdents_callback *)dirent;
Michael Halcrowa8f12862009-01-06 14:42:03 -080083 size_t name_size;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -080084 char *name;
Michael Halcrow237fead2006-10-04 02:16:22 -070085 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -070086
Michael Halcrow237fead2006-10-04 02:16:22 -070087 buf->filldir_called++;
Michael Halcrowaddd65ad2009-01-06 14:42:00 -080088 rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
Al Viro0747fdb2013-06-16 20:05:38 +040089 buf->sb, lower_name,
Michael Halcrowaddd65ad2009-01-06 14:42:00 -080090 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);
Michael Halcrow237fead2006-10-04 02:16:22 -070095 goto out;
96 }
Al Viro2de5f052013-05-22 21:23:40 -040097 buf->caller->pos = buf->ctx.pos;
98 rc = !dir_emit(buf->caller, name, name_size, ino, d_type);
Michael Halcrowaddd65ad2009-01-06 14:42:00 -080099 kfree(name);
Al Viro2de5f052013-05-22 21:23:40 -0400100 if (!rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700101 buf->entries_written++;
102out:
103 return rc;
104}
105
106/**
107 * ecryptfs_readdir
Michael Halcrowaddd65ad2009-01-06 14:42:00 -0800108 * @file: The eCryptfs directory file
Al Viro2de5f052013-05-22 21:23:40 -0400109 * @ctx: The actor to feed the entries to
Michael Halcrow237fead2006-10-04 02:16:22 -0700110 */
Al Viro2de5f052013-05-22 21:23:40 -0400111static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
Michael Halcrow237fead2006-10-04 02:16:22 -0700112{
113 int rc;
114 struct file *lower_file;
Al Viro0747fdb2013-06-16 20:05:38 +0400115 struct inode *inode = file_inode(file);
Al Viro2de5f052013-05-22 21:23:40 -0400116 struct ecryptfs_getdents_callback buf = {
117 .ctx.actor = ecryptfs_filldir,
118 .caller = ctx,
Al Viro0747fdb2013-06-16 20:05:38 +0400119 .sb = inode->i_sb,
Al Viro2de5f052013-05-22 21:23:40 -0400120 };
Michael Halcrow237fead2006-10-04 02:16:22 -0700121 lower_file = ecryptfs_file_to_lower(file);
Al Viro2de5f052013-05-22 21:23:40 -0400122 lower_file->f_pos = ctx->pos;
Al Viro5c0ba4e2013-05-15 13:52:59 -0400123 rc = iterate_dir(lower_file, &buf.ctx);
Al Viro2de5f052013-05-22 21:23:40 -0400124 ctx->pos = buf.ctx.pos;
Michael Halcrow7d6c7042008-10-15 22:02:49 -0700125 if (rc < 0)
126 goto out;
127 if (buf.filldir_called && !buf.entries_written)
128 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700129 if (rc >= 0)
Michael Halcrow7d6c7042008-10-15 22:02:49 -0700130 fsstack_copy_attr_atime(inode,
Al Viro496ad9a2013-01-23 17:07:38 -0500131 file_inode(lower_file));
Michael Halcrow7d6c7042008-10-15 22:02:49 -0700132out:
Michael Halcrow237fead2006-10-04 02:16:22 -0700133 return rc;
134}
135
136struct kmem_cache *ecryptfs_file_info_cache;
137
Tyler Hickse3ccaa92012-06-20 23:50:59 -0700138static 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;
175out:
176 mutex_unlock(&crypt_stat->cs_mutex);
177 return rc;
178}
179
Michael Halcrow237fead2006-10-04 02:16:22 -0700180/**
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 */
189static 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;
Josef "Jeff" Sipekbd243a42006-12-08 02:36:48 -0800194 struct dentry *ecryptfs_dentry = file->f_path.dentry;
Michael Halcrow237fead2006-10-04 02:16:22 -0700195 /* Private value of ecryptfs_dentry allocated in
196 * ecryptfs_lookup() */
Michael Halcrow237fead2006-10-04 02:16:22 -0700197 struct ecryptfs_file_info *file_info;
Michael Halcrow237fead2006-10-04 02:16:22 -0700198
Michael Halcrowe77a56d2007-02-12 00:53:47 -0800199 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 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700210 /* Released in ecryptfs_release or end of function if failure */
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800211 file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700212 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 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700219 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
Michael Halcrow237fead2006-10-04 02:16:22 -0700220 mutex_lock(&crypt_stat->cs_mutex);
Michael Halcrowe2bd99e2007-02-12 00:53:49 -0800221 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
Michael Halcrow237fead2006-10-04 02:16:22 -0700222 ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
223 /* Policy code enabled in future release */
Michael Halcrow2ed92552007-10-16 01:28:10 -0700224 crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
225 | ECRYPTFS_ENCRYPTED);
Michael Halcrow237fead2006-10-04 02:16:22 -0700226 }
227 mutex_unlock(&crypt_stat->cs_mutex);
Tyler Hicks3b06b3e2011-05-24 03:49:02 -0500228 rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode);
Roberto Sassu27992892010-11-03 11:11:28 +0100229 if (rc) {
230 printk(KERN_ERR "%s: Error attempting to initialize "
Tyler Hicks332ab162011-04-14 15:35:11 -0500231 "the lower file for the dentry with name "
Roberto Sassu27992892010-11-03 11:11:28 +0100232 "[%s]; rc = [%d]\n", __func__,
233 ecryptfs_dentry->d_name.name, rc);
234 goto out_free;
Michael Halcrow72b55ff2008-07-23 21:30:07 -0700235 }
Roberto Sassu0abe1162010-11-03 11:11:34 +0100236 if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE)
237 == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) {
Erez Zadoke27759d2009-12-03 13:35:27 -0500238 rc = -EPERM;
Tyler Hicks332ab162011-04-14 15:35:11 -0500239 printk(KERN_WARNING "%s: Lower file is RO; eCryptfs "
Erez Zadoke27759d2009-12-03 13:35:27 -0500240 "file must hence be opened RO\n", __func__);
Tyler Hicks332ab162011-04-14 15:35:11 -0500241 goto out_put;
Erez Zadoke27759d2009-12-03 13:35:27 -0500242 }
Michael Halcrow2ed92552007-10-16 01:28:10 -0700243 ecryptfs_set_file_lower(
244 file, ecryptfs_inode_to_private(inode)->lower_file);
Michael Halcrow237fead2006-10-04 02:16:22 -0700245 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
246 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
Michael Halcrow2f9b12a2008-04-29 00:59:52 -0700247 mutex_lock(&crypt_stat->cs_mutex);
Michael Halcrowe2bd99e2007-02-12 00:53:49 -0800248 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
Michael Halcrow2f9b12a2008-04-29 00:59:52 -0700249 mutex_unlock(&crypt_stat->cs_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -0700250 rc = 0;
251 goto out;
252 }
Tyler Hickse3ccaa92012-06-20 23:50:59 -0700253 rc = read_or_initialize_metadata(ecryptfs_dentry);
254 if (rc)
255 goto out_put;
Joe Perches888d57b2010-11-10 15:46:16 -0800256 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));
Michael Halcrow237fead2006-10-04 02:16:22 -0700259 goto out;
Tyler Hicks332ab162011-04-14 15:35:11 -0500260out_put:
261 ecryptfs_put_lower_file(inode);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700262out_free:
Michael Halcrow237fead2006-10-04 02:16:22 -0700263 kmem_cache_free(ecryptfs_file_info_cache,
264 ecryptfs_file_to_private(file));
265out:
266 return rc;
267}
268
269static int ecryptfs_flush(struct file *file, fl_owner_t td)
270{
Tyler Hicks64e66512012-09-12 18:38:00 -0700271 struct file *lower_file = ecryptfs_file_to_lower(file);
272
Al Viro72c2d532013-09-22 16:27:52 -0400273 if (lower_file->f_op->flush) {
Tyler Hicks64e66512012-09-12 18:38:00 -0700274 filemap_write_and_wait(file->f_mapping);
275 return lower_file->f_op->flush(lower_file, td);
276 }
277
278 return 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700279}
280
281static int ecryptfs_release(struct inode *inode, struct file *file)
282{
Tyler Hicks332ab162011-04-14 15:35:11 -0500283 ecryptfs_put_lower_file(inode);
Michael Halcrow2ed92552007-10-16 01:28:10 -0700284 kmem_cache_free(ecryptfs_file_info_cache,
285 ecryptfs_file_to_private(file));
286 return 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700287}
288
289static int
Josef Bacik02c24a82011-07-16 20:44:56 -0400290ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
Michael Halcrow237fead2006-10-04 02:16:22 -0700291{
Tyler Hicksbc5abcf2013-06-04 10:24:56 -0700292 int rc;
293
294 rc = filemap_write_and_wait(file->f_mapping);
295 if (rc)
296 return rc;
297
Tyler Hicks821f7492012-07-03 16:50:57 -0700298 return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
Michael Halcrow237fead2006-10-04 02:16:22 -0700299}
300
301static 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);
Al Viro72c2d532013-09-22 16:27:52 -0400307 if (lower_file->f_op->fasync)
Michael Halcrow237fead2006-10-04 02:16:22 -0700308 rc = lower_file->f_op->fasync(fd, lower_file, flag);
309 return rc;
310}
311
Tyler Hicksc43f7b82009-11-03 11:45:11 -0600312static long
313ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
314{
Tyler Hicks2000f5b2013-11-13 10:09:42 -0800315 struct file *lower_file = ecryptfs_file_to_lower(file);
Tyler Hicksc43f7b82009-11-03 11:45:11 -0600316 long rc = -ENOTTY;
317
Al Virobdd35362013-11-09 22:19:48 -0500318 if (lower_file->f_op->unlocked_ioctl)
Tyler Hicksc43f7b82009-11-03 11:45:11 -0600319 rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
320 return rc;
321}
322
323#ifdef CONFIG_COMPAT
324static long
325ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
326{
Tyler Hicks2000f5b2013-11-13 10:09:42 -0800327 struct file *lower_file = ecryptfs_file_to_lower(file);
Tyler Hicksc43f7b82009-11-03 11:45:11 -0600328 long rc = -ENOIOCTLCMD;
329
Al Viro72c2d532013-09-22 16:27:52 -0400330 if (lower_file->f_op && lower_file->f_op->compat_ioctl)
Tyler Hicksc43f7b82009-11-03 11:45:11 -0600331 rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
332 return rc;
333}
334#endif
Michael Halcrow237fead2006-10-04 02:16:22 -0700335
336const struct file_operations ecryptfs_dir_fops = {
Al Viro2de5f052013-05-22 21:23:40 -0400337 .iterate = ecryptfs_readdir,
Andy Whitcroft323ef682011-02-16 04:49:59 +0000338 .read = generic_read_dir,
Tyler Hicksc43f7b82009-11-03 11:45:11 -0600339 .unlocked_ioctl = ecryptfs_unlocked_ioctl,
340#ifdef CONFIG_COMPAT
341 .compat_ioctl = ecryptfs_compat_ioctl,
342#endif
Michael Halcrow237fead2006-10-04 02:16:22 -0700343 .open = ecryptfs_open,
344 .flush = ecryptfs_flush,
345 .release = ecryptfs_release,
346 .fsync = ecryptfs_fsync,
347 .fasync = ecryptfs_fasync,
Michael Halcrowe9f6a992007-10-16 01:28:04 -0700348 .splice_read = generic_file_splice_read,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200349 .llseek = default_llseek,
Michael Halcrow237fead2006-10-04 02:16:22 -0700350};
351
352const struct file_operations ecryptfs_main_fops = {
Michael Halcrow53a27312007-05-23 13:58:15 -0700353 .llseek = generic_file_llseek,
Al Viro02797822014-04-02 14:40:38 -0400354 .read = new_sync_read,
355 .read_iter = ecryptfs_read_update_atime,
Al Viro81742022014-04-03 03:17:43 -0400356 .write = new_sync_write,
357 .write_iter = generic_file_write_iter,
Al Viro2de5f052013-05-22 21:23:40 -0400358 .iterate = ecryptfs_readdir,
Tyler Hicksc43f7b82009-11-03 11:45:11 -0600359 .unlocked_ioctl = ecryptfs_unlocked_ioctl,
360#ifdef CONFIG_COMPAT
361 .compat_ioctl = ecryptfs_compat_ioctl,
362#endif
Tyler Hicks821f7492012-07-03 16:50:57 -0700363 .mmap = generic_file_mmap,
Michael Halcrow237fead2006-10-04 02:16:22 -0700364 .open = ecryptfs_open,
365 .flush = ecryptfs_flush,
366 .release = ecryptfs_release,
367 .fsync = ecryptfs_fsync,
368 .fasync = ecryptfs_fasync,
Michael Halcrowe9f6a992007-10-16 01:28:04 -0700369 .splice_read = generic_file_splice_read,
Michael Halcrow237fead2006-10-04 02:16:22 -0700370};