~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/ecryptfs/file.c

Version: ~ [ linux-5.10-rc5 ] ~ [ linux-5.9.10 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.79 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.159 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.208 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.245 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.245 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /**
  2  * eCryptfs: Linux filesystem encryption layer
  3  *
  4  * Copyright (C) 1997-2004 Erez Zadok
  5  * Copyright (C) 2001-2004 Stony Brook University
  6  * Copyright (C) 2004-2007 International Business Machines Corp.
  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/slab.h>
 29 #include <linux/mount.h>
 30 #include <linux/pagemap.h>
 31 #include <linux/security.h>
 32 #include <linux/compat.h>
 33 #include <linux/fs_stack.h>
 34 #include "ecryptfs_kernel.h"
 35 
 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                                 struct iov_iter *to)
 48 {
 49         ssize_t rc;
 50         struct path *path;
 51         struct file *file = iocb->ki_filp;
 52 
 53         rc = generic_file_read_iter(iocb, to);
 54         if (rc >= 0) {
 55                 path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);
 56                 touch_atime(path);
 57         }
 58         return rc;
 59 }
 60 
 61 struct ecryptfs_getdents_callback {
 62         struct dir_context ctx;
 63         struct dir_context *caller;
 64         struct super_block *sb;
 65         int filldir_called;
 66         int entries_written;
 67 };
 68 
 69 /* Inspired by generic filldir in fs/readdir.c */
 70 static int
 71 ecryptfs_filldir(struct dir_context *ctx, const char *lower_name,
 72                  int lower_namelen, loff_t offset, u64 ino, unsigned int d_type)
 73 {
 74         struct ecryptfs_getdents_callback *buf =
 75                 container_of(ctx, struct ecryptfs_getdents_callback, ctx);
 76         size_t name_size;
 77         char *name;
 78         int rc;
 79 
 80         buf->filldir_called++;
 81         rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
 82                                                   buf->sb, lower_name,
 83                                                   lower_namelen);
 84         if (rc) {
 85                 printk(KERN_ERR "%s: Error attempting to decode and decrypt "
 86                        "filename [%s]; rc = [%d]\n", __func__, lower_name,
 87                        rc);
 88                 goto out;
 89         }
 90         buf->caller->pos = buf->ctx.pos;
 91         rc = !dir_emit(buf->caller, name, name_size, ino, d_type);
 92         kfree(name);
 93         if (!rc)
 94                 buf->entries_written++;
 95 out:
 96         return rc;
 97 }
 98 
 99 /**
100  * ecryptfs_readdir
101  * @file: The eCryptfs directory file
102  * @ctx: The actor to feed the entries to
103  */
104 static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
105 {
106         int rc;
107         struct file *lower_file;
108         struct inode *inode = file_inode(file);
109         struct ecryptfs_getdents_callback buf = {
110                 .ctx.actor = ecryptfs_filldir,
111                 .caller = ctx,
112                 .sb = inode->i_sb,
113         };
114         lower_file = ecryptfs_file_to_lower(file);
115         rc = iterate_dir(lower_file, &buf.ctx);
116         ctx->pos = buf.ctx.pos;
117         if (rc < 0)
118                 goto out;
119         if (buf.filldir_called && !buf.entries_written)
120                 goto out;
121         if (rc >= 0)
122                 fsstack_copy_attr_atime(inode,
123                                         file_inode(lower_file));
124 out:
125         return rc;
126 }
127 
128 struct kmem_cache *ecryptfs_file_info_cache;
129 
130 static int read_or_initialize_metadata(struct dentry *dentry)
131 {
132         struct inode *inode = d_inode(dentry);
133         struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
134         struct ecryptfs_crypt_stat *crypt_stat;
135         int rc;
136 
137         crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
138         mount_crypt_stat = &ecryptfs_superblock_to_private(
139                                                 inode->i_sb)->mount_crypt_stat;
140         mutex_lock(&crypt_stat->cs_mutex);
141 
142         if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED &&
143             crypt_stat->flags & ECRYPTFS_KEY_VALID) {
144                 rc = 0;
145                 goto out;
146         }
147 
148         rc = ecryptfs_read_metadata(dentry);
149         if (!rc)
150                 goto out;
151 
152         if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) {
153                 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
154                                        | ECRYPTFS_ENCRYPTED);
155                 rc = 0;
156                 goto out;
157         }
158 
159         if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) &&
160             !i_size_read(ecryptfs_inode_to_lower(inode))) {
161                 rc = ecryptfs_initialize_file(dentry, inode);
162                 if (!rc)
163                         goto out;
164         }
165 
166         rc = -EIO;
167 out:
168         mutex_unlock(&crypt_stat->cs_mutex);
169         return rc;
170 }
171 
172 static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma)
173 {
174         struct file *lower_file = ecryptfs_file_to_lower(file);
175         /*
176          * Don't allow mmap on top of file systems that don't support it
177          * natively.  If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs
178          * allows recursive mounting, this will need to be extended.
179          */
180         if (!lower_file->f_op->mmap)
181                 return -ENODEV;
182         return generic_file_mmap(file, vma);
183 }
184 
185 /**
186  * ecryptfs_open
187  * @inode: inode specifying file to open
188  * @file: Structure to return filled in
189  *
190  * Opens the file specified by inode.
191  *
192  * Returns zero on success; non-zero otherwise
193  */
194 static int ecryptfs_open(struct inode *inode, struct file *file)
195 {
196         int rc = 0;
197         struct ecryptfs_crypt_stat *crypt_stat = NULL;
198         struct dentry *ecryptfs_dentry = file->f_path.dentry;
199         /* Private value of ecryptfs_dentry allocated in
200          * ecryptfs_lookup() */
201         struct ecryptfs_file_info *file_info;
202 
203         /* Released in ecryptfs_release or end of function if failure */
204         file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
205         ecryptfs_set_file_private(file, file_info);
206         if (!file_info) {
207                 ecryptfs_printk(KERN_ERR,
208                                 "Error attempting to allocate memory\n");
209                 rc = -ENOMEM;
210                 goto out;
211         }
212         crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
213         mutex_lock(&crypt_stat->cs_mutex);
214         if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
215                 ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
216                 /* Policy code enabled in future release */
217                 crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
218                                       | ECRYPTFS_ENCRYPTED);
219         }
220         mutex_unlock(&crypt_stat->cs_mutex);
221         rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode);
222         if (rc) {
223                 printk(KERN_ERR "%s: Error attempting to initialize "
224                         "the lower file for the dentry with name "
225                         "[%pd]; rc = [%d]\n", __func__,
226                         ecryptfs_dentry, rc);
227                 goto out_free;
228         }
229         if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE)
230             == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) {
231                 rc = -EPERM;
232                 printk(KERN_WARNING "%s: Lower file is RO; eCryptfs "
233                        "file must hence be opened RO\n", __func__);
234                 goto out_put;
235         }
236         ecryptfs_set_file_lower(
237                 file, ecryptfs_inode_to_private(inode)->lower_file);
238         rc = read_or_initialize_metadata(ecryptfs_dentry);
239         if (rc)
240                 goto out_put;
241         ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = "
242                         "[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino,
243                         (unsigned long long)i_size_read(inode));
244         goto out;
245 out_put:
246         ecryptfs_put_lower_file(inode);
247 out_free:
248         kmem_cache_free(ecryptfs_file_info_cache,
249                         ecryptfs_file_to_private(file));
250 out:
251         return rc;
252 }
253 
254 /**
255  * ecryptfs_dir_open
256  * @inode: inode specifying file to open
257  * @file: Structure to return filled in
258  *
259  * Opens the file specified by inode.
260  *
261  * Returns zero on success; non-zero otherwise
262  */
263 static int ecryptfs_dir_open(struct inode *inode, struct file *file)
264 {
265         struct dentry *ecryptfs_dentry = file->f_path.dentry;
266         /* Private value of ecryptfs_dentry allocated in
267          * ecryptfs_lookup() */
268         struct ecryptfs_file_info *file_info;
269         struct file *lower_file;
270 
271         /* Released in ecryptfs_release or end of function if failure */
272         file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
273         ecryptfs_set_file_private(file, file_info);
274         if (unlikely(!file_info)) {
275                 ecryptfs_printk(KERN_ERR,
276                                 "Error attempting to allocate memory\n");
277                 return -ENOMEM;
278         }
279         lower_file = dentry_open(ecryptfs_dentry_to_lower_path(ecryptfs_dentry),
280                                  file->f_flags, current_cred());
281         if (IS_ERR(lower_file)) {
282                 printk(KERN_ERR "%s: Error attempting to initialize "
283                         "the lower file for the dentry with name "
284                         "[%pd]; rc = [%ld]\n", __func__,
285                         ecryptfs_dentry, PTR_ERR(lower_file));
286                 kmem_cache_free(ecryptfs_file_info_cache, file_info);
287                 return PTR_ERR(lower_file);
288         }
289         ecryptfs_set_file_lower(file, lower_file);
290         return 0;
291 }
292 
293 static int ecryptfs_flush(struct file *file, fl_owner_t td)
294 {
295         struct file *lower_file = ecryptfs_file_to_lower(file);
296 
297         if (lower_file->f_op->flush) {
298                 filemap_write_and_wait(file->f_mapping);
299                 return lower_file->f_op->flush(lower_file, td);
300         }
301 
302         return 0;
303 }
304 
305 static int ecryptfs_release(struct inode *inode, struct file *file)
306 {
307         ecryptfs_put_lower_file(inode);
308         kmem_cache_free(ecryptfs_file_info_cache,
309                         ecryptfs_file_to_private(file));
310         return 0;
311 }
312 
313 static int ecryptfs_dir_release(struct inode *inode, struct file *file)
314 {
315         fput(ecryptfs_file_to_lower(file));
316         kmem_cache_free(ecryptfs_file_info_cache,
317                         ecryptfs_file_to_private(file));
318         return 0;
319 }
320 
321 static loff_t ecryptfs_dir_llseek(struct file *file, loff_t offset, int whence)
322 {
323         return vfs_llseek(ecryptfs_file_to_lower(file), offset, whence);
324 }
325 
326 static int
327 ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
328 {
329         int rc;
330 
331         rc = filemap_write_and_wait(file->f_mapping);
332         if (rc)
333                 return rc;
334 
335         return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
336 }
337 
338 static int ecryptfs_fasync(int fd, struct file *file, int flag)
339 {
340         int rc = 0;
341         struct file *lower_file = NULL;
342 
343         lower_file = ecryptfs_file_to_lower(file);
344         if (lower_file->f_op->fasync)
345                 rc = lower_file->f_op->fasync(fd, lower_file, flag);
346         return rc;
347 }
348 
349 static long
350 ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
351 {
352         struct file *lower_file = ecryptfs_file_to_lower(file);
353         long rc = -ENOTTY;
354 
355         if (!lower_file->f_op->unlocked_ioctl)
356                 return rc;
357 
358         switch (cmd) {
359         case FITRIM:
360         case FS_IOC_GETFLAGS:
361         case FS_IOC_SETFLAGS:
362         case FS_IOC_GETVERSION:
363         case FS_IOC_SETVERSION:
364                 rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
365                 fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
366 
367                 return rc;
368         default:
369                 return rc;
370         }
371 }
372 
373 #ifdef CONFIG_COMPAT
374 static long
375 ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
376 {
377         struct file *lower_file = ecryptfs_file_to_lower(file);
378         long rc = -ENOIOCTLCMD;
379 
380         if (!lower_file->f_op->compat_ioctl)
381                 return rc;
382 
383         switch (cmd) {
384         case FS_IOC32_GETFLAGS:
385         case FS_IOC32_SETFLAGS:
386         case FS_IOC32_GETVERSION:
387         case FS_IOC32_SETVERSION:
388                 rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
389                 fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
390 
391                 return rc;
392         default:
393                 return rc;
394         }
395 }
396 #endif
397 
398 const struct file_operations ecryptfs_dir_fops = {
399         .iterate_shared = ecryptfs_readdir,
400         .read = generic_read_dir,
401         .unlocked_ioctl = ecryptfs_unlocked_ioctl,
402 #ifdef CONFIG_COMPAT
403         .compat_ioctl = ecryptfs_compat_ioctl,
404 #endif
405         .open = ecryptfs_dir_open,
406         .release = ecryptfs_dir_release,
407         .fsync = ecryptfs_fsync,
408         .llseek = ecryptfs_dir_llseek,
409 };
410 
411 const struct file_operations ecryptfs_main_fops = {
412         .llseek = generic_file_llseek,
413         .read_iter = ecryptfs_read_update_atime,
414         .write_iter = generic_file_write_iter,
415         .unlocked_ioctl = ecryptfs_unlocked_ioctl,
416 #ifdef CONFIG_COMPAT
417         .compat_ioctl = ecryptfs_compat_ioctl,
418 #endif
419         .mmap = ecryptfs_mmap,
420         .open = ecryptfs_open,
421         .flush = ecryptfs_flush,
422         .release = ecryptfs_release,
423         .fsync = ecryptfs_fsync,
424         .fasync = ecryptfs_fasync,
425         .splice_read = generic_file_splice_read,
426 };
427 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp