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 <mahalcro@us.ibm.com> 8 * Michael C. Thompsion <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/vmalloc.h> 28 #include <linux/pagemap.h> 29 #include <linux/dcache.h> 30 #include <linux/namei.h> 31 #include <linux/mount.h> 32 #include <linux/crypto.h> 33 #include <linux/fs_stack.h> 34 #include "ecryptfs_kernel.h" 35 36 static struct dentry *lock_parent(struct dentry *dentry) 37 { 38 struct dentry *dir; 39 40 dir = dget(dentry->d_parent); 41 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT); 42 return dir; 43 } 44 45 static void unlock_parent(struct dentry *dentry) 46 { 47 mutex_unlock(&(dentry->d_parent->d_inode->i_mutex)); 48 dput(dentry->d_parent); 49 } 50 51 static void unlock_dir(struct dentry *dir) 52 { 53 mutex_unlock(&dir->d_inode->i_mutex); 54 dput(dir); 55 } 56 57 /** 58 * ecryptfs_create_underlying_file 59 * @lower_dir_inode: inode of the parent in the lower fs of the new file 60 * @lower_dentry: New file's dentry in the lower fs 61 * @ecryptfs_dentry: New file's dentry in ecryptfs 62 * @mode: The mode of the new file 63 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount 64 * 65 * Creates the file in the lower file system. 66 * 67 * Returns zero on success; non-zero on error condition 68 */ 69 static int 70 ecryptfs_create_underlying_file(struct inode *lower_dir_inode, 71 struct dentry *dentry, int mode, 72 struct nameidata *nd) 73 { 74 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); 75 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); 76 struct dentry *dentry_save; 77 struct vfsmount *vfsmount_save; 78 int rc; 79 80 dentry_save = nd->dentry; 81 vfsmount_save = nd->mnt; 82 nd->dentry = lower_dentry; 83 nd->mnt = lower_mnt; 84 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd); 85 nd->dentry = dentry_save; 86 nd->mnt = vfsmount_save; 87 return rc; 88 } 89 90 /** 91 * ecryptfs_do_create 92 * @directory_inode: inode of the new file's dentry's parent in ecryptfs 93 * @ecryptfs_dentry: New file's dentry in ecryptfs 94 * @mode: The mode of the new file 95 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount 96 * 97 * Creates the underlying file and the eCryptfs inode which will link to 98 * it. It will also update the eCryptfs directory inode to mimic the 99 * stat of the lower directory inode. 100 * 101 * Returns zero on success; non-zero on error condition 102 */ 103 static int 104 ecryptfs_do_create(struct inode *directory_inode, 105 struct dentry *ecryptfs_dentry, int mode, 106 struct nameidata *nd) 107 { 108 int rc; 109 struct dentry *lower_dentry; 110 struct dentry *lower_dir_dentry; 111 112 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 113 lower_dir_dentry = lock_parent(lower_dentry); 114 if (unlikely(IS_ERR(lower_dir_dentry))) { 115 ecryptfs_printk(KERN_ERR, "Error locking directory of " 116 "dentry\n"); 117 rc = PTR_ERR(lower_dir_dentry); 118 goto out; 119 } 120 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode, 121 ecryptfs_dentry, mode, nd); 122 if (unlikely(rc)) { 123 ecryptfs_printk(KERN_ERR, 124 "Failure to create underlying file\n"); 125 goto out_lock; 126 } 127 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, 128 directory_inode->i_sb, 0); 129 if (rc) { 130 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n"); 131 goto out_lock; 132 } 133 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode); 134 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode); 135 out_lock: 136 unlock_dir(lower_dir_dentry); 137 out: 138 return rc; 139 } 140 141 /** 142 * grow_file 143 * @ecryptfs_dentry: the ecryptfs dentry 144 * @lower_file: The lower file 145 * @inode: The ecryptfs inode 146 * @lower_inode: The lower inode 147 * 148 * This is the code which will grow the file to its correct size. 149 */ 150 static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file, 151 struct inode *inode, struct inode *lower_inode) 152 { 153 int rc = 0; 154 struct file fake_file; 155 struct ecryptfs_file_info tmp_file_info; 156 157 memset(&fake_file, 0, sizeof(fake_file)); 158 fake_file.f_path.dentry = ecryptfs_dentry; 159 memset(&tmp_file_info, 0, sizeof(tmp_file_info)); 160 ecryptfs_set_file_private(&fake_file, &tmp_file_info); 161 ecryptfs_set_file_lower(&fake_file, lower_file); 162 rc = ecryptfs_fill_zeros(&fake_file, 1); 163 if (rc) { 164 ecryptfs_inode_to_private(inode)->crypt_stat.flags |= 165 ECRYPTFS_SECURITY_WARNING; 166 ecryptfs_printk(KERN_WARNING, "Error attempting to fill zeros " 167 "in file; rc = [%d]\n", rc); 168 goto out; 169 } 170 i_size_write(inode, 0); 171 rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode, 172 inode, ecryptfs_dentry, 173 ECRYPTFS_LOWER_I_MUTEX_NOT_HELD); 174 ecryptfs_inode_to_private(inode)->crypt_stat.flags |= ECRYPTFS_NEW_FILE; 175 out: 176 return rc; 177 } 178 179 /** 180 * ecryptfs_initialize_file 181 * 182 * Cause the file to be changed from a basic empty file to an ecryptfs 183 * file with a header and first data page. 184 * 185 * Returns zero on success 186 */ 187 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) 188 { 189 int rc = 0; 190 int lower_flags; 191 struct ecryptfs_crypt_stat *crypt_stat; 192 struct dentry *lower_dentry; 193 struct file *lower_file; 194 struct inode *inode, *lower_inode; 195 struct vfsmount *lower_mnt; 196 197 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); 198 ecryptfs_printk(KERN_DEBUG, "lower_dentry->d_name.name = [%s]\n", 199 lower_dentry->d_name.name); 200 inode = ecryptfs_dentry->d_inode; 201 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; 202 lower_flags = ((O_CREAT | O_TRUNC) & O_ACCMODE) | O_RDWR; 203 lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); 204 /* Corresponding fput() at end of this function */ 205 if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt, 206 lower_flags))) { 207 ecryptfs_printk(KERN_ERR, 208 "Error opening dentry; rc = [%i]\n", rc); 209 goto out; 210 } 211 lower_inode = lower_dentry->d_inode; 212 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { 213 ecryptfs_printk(KERN_DEBUG, "This is a directory\n"); 214 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); 215 goto out_fput; 216 } 217 crypt_stat->flags |= ECRYPTFS_NEW_FILE; 218 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n"); 219 rc = ecryptfs_new_file_context(ecryptfs_dentry); 220 if (rc) { 221 ecryptfs_printk(KERN_DEBUG, "Error creating new file " 222 "context\n"); 223 goto out_fput; 224 } 225 rc = ecryptfs_write_metadata(ecryptfs_dentry, lower_file); 226 if (rc) { 227 ecryptfs_printk(KERN_DEBUG, "Error writing headers\n"); 228 goto out_fput; 229 } 230 rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode); 231 out_fput: 232 if ((rc = ecryptfs_close_lower_file(lower_file))) 233 printk(KERN_ERR "Error closing lower_file\n"); 234 out: 235 return rc; 236 } 237 238 /** 239 * ecryptfs_create 240 * @dir: The inode of the directory in which to create the file. 241 * @dentry: The eCryptfs dentry 242 * @mode: The mode of the new file. 243 * @nd: nameidata 244 * 245 * Creates a new file. 246 * 247 * Returns zero on success; non-zero on error condition 248 */ 249 static int 250 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry, 251 int mode, struct nameidata *nd) 252 { 253 int rc; 254 255 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd); 256 if (unlikely(rc)) { 257 ecryptfs_printk(KERN_WARNING, "Failed to create file in" 258 "lower filesystem\n"); 259 goto out; 260 } 261 /* At this point, a file exists on "disk"; we need to make sure 262 * that this on disk file is prepared to be an ecryptfs file */ 263 rc = ecryptfs_initialize_file(ecryptfs_dentry); 264 out: 265 return rc; 266 } 267 268 /** 269 * ecryptfs_lookup 270 * @dir: inode 271 * @dentry: The dentry 272 * @nd: nameidata, may be NULL 273 * 274 * Find a file on disk. If the file does not exist, then we'll add it to the 275 * dentry cache and continue on to read it from the disk. 276 */ 277 static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, 278 struct nameidata *nd) 279 { 280 int rc = 0; 281 struct dentry *lower_dir_dentry; 282 struct dentry *lower_dentry; 283 struct vfsmount *lower_mnt; 284 char *encoded_name; 285 int encoded_namelen; 286 struct ecryptfs_crypt_stat *crypt_stat = NULL; 287 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 288 char *page_virt = NULL; 289 struct inode *lower_inode; 290 u64 file_size; 291 292 lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent); 293 dentry->d_op = &ecryptfs_dops; 294 if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, ".")) 295 || (dentry->d_name.len == 2 296 && !strcmp(dentry->d_name.name, ".."))) { 297 d_drop(dentry); 298 goto out; 299 } 300 encoded_namelen = ecryptfs_encode_filename(crypt_stat, 301 dentry->d_name.name, 302 dentry->d_name.len, 303 &encoded_name); 304 if (encoded_namelen < 0) { 305 rc = encoded_namelen; 306 d_drop(dentry); 307 goto out; 308 } 309 ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen " 310 "= [%d]\n", encoded_name, encoded_namelen); 311 lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry, 312 encoded_namelen - 1); 313 kfree(encoded_name); 314 if (IS_ERR(lower_dentry)) { 315 ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n"); 316 rc = PTR_ERR(lower_dentry); 317 d_drop(dentry); 318 goto out; 319 } 320 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent)); 321 ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->" 322 "d_name.name = [%s]\n", lower_dentry, 323 lower_dentry->d_name.name); 324 lower_inode = lower_dentry->d_inode; 325 fsstack_copy_attr_atime(dir, lower_dir_dentry->d_inode); 326 BUG_ON(!atomic_read(&lower_dentry->d_count)); 327 ecryptfs_set_dentry_private(dentry, 328 kmem_cache_alloc(ecryptfs_dentry_info_cache, 329 GFP_KERNEL)); 330 if (!ecryptfs_dentry_to_private(dentry)) { 331 rc = -ENOMEM; 332 ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting " 333 "to allocate ecryptfs_dentry_info struct\n"); 334 goto out_dput; 335 } 336 ecryptfs_set_dentry_lower(dentry, lower_dentry); 337 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt); 338 if (!lower_dentry->d_inode) { 339 /* We want to add because we couldn't find in lower */ 340 d_add(dentry, NULL); 341 goto out; 342 } 343 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 1); 344 if (rc) { 345 ecryptfs_printk(KERN_ERR, "Error interposing\n"); 346 goto out_dput; 347 } 348 if (S_ISDIR(lower_inode->i_mode)) { 349 ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n"); 350 goto out; 351 } 352 if (S_ISLNK(lower_inode->i_mode)) { 353 ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n"); 354 goto out; 355 } 356 if (special_file(lower_inode->i_mode)) { 357 ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n"); 358 goto out; 359 } 360 if (!nd) { 361 ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave" 362 "as we *think* we are about to unlink\n"); 363 goto out; 364 } 365 /* Released in this function */ 366 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, 367 GFP_USER); 368 if (!page_virt) { 369 rc = -ENOMEM; 370 ecryptfs_printk(KERN_ERR, 371 "Cannot ecryptfs_kmalloc a page\n"); 372 goto out_dput; 373 } 374 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; 375 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) 376 ecryptfs_set_default_sizes(crypt_stat); 377 rc = ecryptfs_read_and_validate_header_region(page_virt, lower_dentry, 378 nd->mnt); 379 if (rc) { 380 rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry); 381 if (rc) { 382 printk(KERN_DEBUG "Valid metadata not found in header " 383 "region or xattr region; treating file as " 384 "unencrypted\n"); 385 rc = 0; 386 kmem_cache_free(ecryptfs_header_cache_2, page_virt); 387 goto out; 388 } 389 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; 390 } 391 mount_crypt_stat = &ecryptfs_superblock_to_private( 392 dentry->d_sb)->mount_crypt_stat; 393 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) { 394 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) 395 file_size = (crypt_stat->header_extent_size 396 + i_size_read(lower_dentry->d_inode)); 397 else 398 file_size = i_size_read(lower_dentry->d_inode); 399 } else { 400 memcpy(&file_size, page_virt, sizeof(file_size)); 401 file_size = be64_to_cpu(file_size); 402 } 403 i_size_write(dentry->d_inode, (loff_t)file_size); 404 kmem_cache_free(ecryptfs_header_cache_2, page_virt); 405 goto out; 406 407 out_dput: 408 dput(lower_dentry); 409 d_drop(dentry); 410 out: 411 return ERR_PTR(rc); 412 } 413 414 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, 415 struct dentry *new_dentry) 416 { 417 struct dentry *lower_old_dentry; 418 struct dentry *lower_new_dentry; 419 struct dentry *lower_dir_dentry; 420 u64 file_size_save; 421 int rc; 422 423 file_size_save = i_size_read(old_dentry->d_inode); 424 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry); 425 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry); 426 dget(lower_old_dentry); 427 dget(lower_new_dentry); 428 lower_dir_dentry = lock_parent(lower_new_dentry); 429 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode, 430 lower_new_dentry); 431 if (rc || !lower_new_dentry->d_inode) 432 goto out_lock; 433 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0); 434 if (rc) 435 goto out_lock; 436 fsstack_copy_attr_times(dir, lower_new_dentry->d_inode); 437 fsstack_copy_inode_size(dir, lower_new_dentry->d_inode); 438 old_dentry->d_inode->i_nlink = 439 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink; 440 i_size_write(new_dentry->d_inode, file_size_save); 441 out_lock: 442 unlock_dir(lower_dir_dentry); 443 dput(lower_new_dentry); 444 dput(lower_old_dentry); 445 d_drop(lower_old_dentry); 446 d_drop(new_dentry); 447 d_drop(old_dentry); 448 return rc; 449 } 450 451 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry) 452 { 453 int rc = 0; 454 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); 455 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir); 456 457 lock_parent(lower_dentry); 458 rc = vfs_unlink(lower_dir_inode, lower_dentry); 459 if (rc) { 460 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc); 461 goto out_unlock; 462 } 463 fsstack_copy_attr_times(dir, lower_dir_inode); 464 dentry->d_inode->i_nlink = 465 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink; 466 dentry->d_inode->i_ctime = dir->i_ctime; 467 out_unlock: 468 unlock_parent(lower_dentry); 469 return rc; 470 } 471 472 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry, 473 const char *symname) 474 { 475 int rc; 476 struct dentry *lower_dentry; 477 struct dentry *lower_dir_dentry; 478 umode_t mode; 479 char *encoded_symname; 480 int encoded_symlen; 481 struct ecryptfs_crypt_stat *crypt_stat = NULL; 482 483 lower_dentry = ecryptfs_dentry_to_lower(dentry); 484 dget(lower_dentry); 485 lower_dir_dentry = lock_parent(lower_dentry); 486 mode = S_IALLUGO; 487 encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname, 488 strlen(symname), 489 &encoded_symname); 490 if (encoded_symlen < 0) { 491 rc = encoded_symlen; 492 goto out_lock; 493 } 494 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry, 495 encoded_symname, mode); 496 kfree(encoded_symname); 497 if (rc || !lower_dentry->d_inode) 498 goto out_lock; 499 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); 500 if (rc) 501 goto out_lock; 502 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 503 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode); 504 out_lock: 505 unlock_dir(lower_dir_dentry); 506 dput(lower_dentry); 507 if (!dentry->d_inode) 508 d_drop(dentry); 509 return rc; 510 } 511 512 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 513 { 514 int rc; 515 struct dentry *lower_dentry; 516 struct dentry *lower_dir_dentry; 517 518 lower_dentry = ecryptfs_dentry_to_lower(dentry); 519 lower_dir_dentry = lock_parent(lower_dentry); 520 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode); 521 if (rc || !lower_dentry->d_inode) 522 goto out; 523 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); 524 if (rc) 525 goto out; 526 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 527 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode); 528 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink; 529 out: 530 unlock_dir(lower_dir_dentry); 531 if (!dentry->d_inode) 532 d_drop(dentry); 533 return rc; 534 } 535 536 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry) 537 { 538 struct dentry *lower_dentry; 539 struct dentry *lower_dir_dentry; 540 int rc; 541 542 lower_dentry = ecryptfs_dentry_to_lower(dentry); 543 dget(dentry); 544 lower_dir_dentry = lock_parent(lower_dentry); 545 dget(lower_dentry); 546 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry); 547 dput(lower_dentry); 548 if (!rc) 549 d_delete(lower_dentry); 550 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 551 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink; 552 unlock_dir(lower_dir_dentry); 553 if (!rc) 554 d_drop(dentry); 555 dput(dentry); 556 return rc; 557 } 558 559 static int 560 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 561 { 562 int rc; 563 struct dentry *lower_dentry; 564 struct dentry *lower_dir_dentry; 565 566 lower_dentry = ecryptfs_dentry_to_lower(dentry); 567 lower_dir_dentry = lock_parent(lower_dentry); 568 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev); 569 if (rc || !lower_dentry->d_inode) 570 goto out; 571 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); 572 if (rc) 573 goto out; 574 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); 575 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode); 576 out: 577 unlock_dir(lower_dir_dentry); 578 if (!dentry->d_inode) 579 d_drop(dentry); 580 return rc; 581 } 582 583 static int 584 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry, 585 struct inode *new_dir, struct dentry *new_dentry) 586 { 587 int rc; 588 struct dentry *lower_old_dentry; 589 struct dentry *lower_new_dentry; 590 struct dentry *lower_old_dir_dentry; 591 struct dentry *lower_new_dir_dentry; 592 593 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry); 594 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry); 595 dget(lower_old_dentry); 596 dget(lower_new_dentry); 597 lower_old_dir_dentry = dget_parent(lower_old_dentry); 598 lower_new_dir_dentry = dget_parent(lower_new_dentry); 599 lock_rename(lower_old_dir_dentry, lower_new_dir_dentry); 600 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry, 601 lower_new_dir_dentry->d_inode, lower_new_dentry); 602 if (rc) 603 goto out_lock; 604 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL); 605 if (new_dir != old_dir) 606 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL); 607 out_lock: 608 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry); 609 dput(lower_new_dentry->d_parent); 610 dput(lower_old_dentry->d_parent); 611 dput(lower_new_dentry); 612 dput(lower_old_dentry); 613 return rc; 614 } 615 616 static int 617 ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz) 618 { 619 int rc; 620 struct dentry *lower_dentry; 621 char *decoded_name; 622 char *lower_buf; 623 mm_segment_t old_fs; 624 struct ecryptfs_crypt_stat *crypt_stat; 625 626 lower_dentry = ecryptfs_dentry_to_lower(dentry); 627 if (!lower_dentry->d_inode->i_op || 628 !lower_dentry->d_inode->i_op->readlink) { 629 rc = -EINVAL; 630 goto out; 631 } 632 /* Released in this function */ 633 lower_buf = kmalloc(bufsiz, GFP_KERNEL); 634 if (lower_buf == NULL) { 635 ecryptfs_printk(KERN_ERR, "Out of memory\n"); 636 rc = -ENOMEM; 637 goto out; 638 } 639 old_fs = get_fs(); 640 set_fs(get_ds()); 641 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ " 642 "lower_dentry->d_name.name = [%s]\n", 643 lower_dentry->d_name.name); 644 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry, 645 (char __user *)lower_buf, 646 bufsiz); 647 set_fs(old_fs); 648 if (rc >= 0) { 649 crypt_stat = NULL; 650 rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc, 651 &decoded_name); 652 if (rc == -ENOMEM) 653 goto out_free_lower_buf; 654 if (rc > 0) { 655 ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes " 656 "to userspace: [%*s]\n", rc, 657 decoded_name); 658 if (copy_to_user(buf, decoded_name, rc)) 659 rc = -EFAULT; 660 } 661 kfree(decoded_name); 662 fsstack_copy_attr_atime(dentry->d_inode, 663 lower_dentry->d_inode); 664 } 665 out_free_lower_buf: 666 kfree(lower_buf); 667 out: 668 return rc; 669 } 670 671 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd) 672 { 673 char *buf; 674 int len = PAGE_SIZE, rc; 675 mm_segment_t old_fs; 676 677 /* Released in ecryptfs_put_link(); only release here on error */ 678 buf = kmalloc(len, GFP_KERNEL); 679 if (!buf) { 680 rc = -ENOMEM; 681 goto out; 682 } 683 old_fs = get_fs(); 684 set_fs(get_ds()); 685 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ " 686 "dentry->d_name.name = [%s]\n", dentry->d_name.name); 687 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len); 688 buf[rc] = '\0'; 689 set_fs(old_fs); 690 if (rc < 0) 691 goto out_free; 692 rc = 0; 693 nd_set_link(nd, buf); 694 goto out; 695 out_free: 696 kfree(buf); 697 out: 698 return ERR_PTR(rc); 699 } 700 701 static void 702 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr) 703 { 704 /* Free the char* */ 705 kfree(nd_get_link(nd)); 706 } 707 708 /** 709 * upper_size_to_lower_size 710 * @crypt_stat: Crypt_stat associated with file 711 * @upper_size: Size of the upper file 712 * 713 * Calculate the requried size of the lower file based on the 714 * specified size of the upper file. This calculation is based on the 715 * number of headers in the underlying file and the extent size. 716 * 717 * Returns Calculated size of the lower file. 718 */ 719 static loff_t 720 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat, 721 loff_t upper_size) 722 { 723 loff_t lower_size; 724 725 lower_size = ( crypt_stat->header_extent_size 726 * crypt_stat->num_header_extents_at_front ); 727 if (upper_size != 0) { 728 loff_t num_extents; 729 730 num_extents = upper_size >> crypt_stat->extent_shift; 731 if (upper_size & ~crypt_stat->extent_mask) 732 num_extents++; 733 lower_size += (num_extents * crypt_stat->extent_size); 734 } 735 return lower_size; 736 } 737 738 /** 739 * ecryptfs_truncate 740 * @dentry: The ecryptfs layer dentry 741 * @new_length: The length to expand the file to 742 * 743 * Function to handle truncations modifying the size of the file. Note 744 * that the file sizes are interpolated. When expanding, we are simply 745 * writing strings of 0's out. When truncating, we need to modify the 746 * underlying file size according to the page index interpolations. 747 * 748 * Returns zero on success; non-zero otherwise 749 */ 750 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) 751 { 752 int rc = 0; 753 struct inode *inode = dentry->d_inode; 754 struct dentry *lower_dentry; 755 struct vfsmount *lower_mnt; 756 struct file fake_ecryptfs_file, *lower_file = NULL; 757 struct ecryptfs_crypt_stat *crypt_stat; 758 loff_t i_size = i_size_read(inode); 759 loff_t lower_size_before_truncate; 760 loff_t lower_size_after_truncate; 761 762 if (unlikely((new_length == i_size))) 763 goto out; 764 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; 765 /* Set up a fake ecryptfs file, this is used to interface with 766 * the file in the underlying filesystem so that the 767 * truncation has an effect there as well. */ 768 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file)); 769 fake_ecryptfs_file.f_path.dentry = dentry; 770 /* Released at out_free: label */ 771 ecryptfs_set_file_private(&fake_ecryptfs_file, 772 kmem_cache_alloc(ecryptfs_file_info_cache, 773 GFP_KERNEL)); 774 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) { 775 rc = -ENOMEM; 776 goto out; 777 } 778 lower_dentry = ecryptfs_dentry_to_lower(dentry); 779 /* This dget & mntget is released through fput at out_fput: */ 780 lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); 781 if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt, 782 O_RDWR))) { 783 ecryptfs_printk(KERN_ERR, 784 "Error opening dentry; rc = [%i]\n", rc); 785 goto out_free; 786 } 787 ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file); 788 /* Switch on growing or shrinking file */ 789 if (new_length > i_size) { 790 rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length); 791 if (rc) { 792 ecryptfs_printk(KERN_ERR, 793 "Problem with fill_zeros\n"); 794 goto out_fput; 795 } 796 i_size_write(inode, new_length); 797 rc = ecryptfs_write_inode_size_to_metadata( 798 lower_file, lower_dentry->d_inode, inode, dentry, 799 ECRYPTFS_LOWER_I_MUTEX_NOT_HELD); 800 if (rc) { 801 printk(KERN_ERR "Problem with " 802 "ecryptfs_write_inode_size_to_metadata; " 803 "rc = [%d]\n", rc); 804 goto out_fput; 805 } 806 } else { /* new_length < i_size_read(inode) */ 807 pgoff_t index = 0; 808 int end_pos_in_page = -1; 809 810 if (new_length != 0) { 811 index = ((new_length - 1) >> PAGE_CACHE_SHIFT); 812 end_pos_in_page = ((new_length - 1) & ~PAGE_CACHE_MASK); 813 } 814 if (end_pos_in_page != (PAGE_CACHE_SIZE - 1)) { 815 if ((rc = ecryptfs_write_zeros(&fake_ecryptfs_file, 816 index, 817 (end_pos_in_page + 1), 818 ((PAGE_CACHE_SIZE - 1) 819 - end_pos_in_page)))) { 820 printk(KERN_ERR "Error attempting to zero out " 821 "the remainder of the end page on " 822 "reducing truncate; rc = [%d]\n", rc); 823 goto out_fput; 824 } 825 } 826 vmtruncate(inode, new_length); 827 rc = ecryptfs_write_inode_size_to_metadata( 828 lower_file, lower_dentry->d_inode, inode, dentry, 829 ECRYPTFS_LOWER_I_MUTEX_NOT_HELD); 830 if (rc) { 831 printk(KERN_ERR "Problem with " 832 "ecryptfs_write_inode_size_to_metadata; " 833 "rc = [%d]\n", rc); 834 goto out_fput; 835 } 836 /* We are reducing the size of the ecryptfs file, and need to 837 * know if we need to reduce the size of the lower file. */ 838 lower_size_before_truncate = 839 upper_size_to_lower_size(crypt_stat, i_size); 840 lower_size_after_truncate = 841 upper_size_to_lower_size(crypt_stat, new_length); 842 if (lower_size_after_truncate < lower_size_before_truncate) 843 vmtruncate(lower_dentry->d_inode, 844 lower_size_after_truncate); 845 } 846 /* Update the access times */ 847 lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime 848 = CURRENT_TIME; 849 mark_inode_dirty_sync(inode); 850 out_fput: 851 if ((rc = ecryptfs_close_lower_file(lower_file))) 852 printk(KERN_ERR "Error closing lower_file\n"); 853 out_free: 854 if (ecryptfs_file_to_private(&fake_ecryptfs_file)) 855 kmem_cache_free(ecryptfs_file_info_cache, 856 ecryptfs_file_to_private(&fake_ecryptfs_file)); 857 out: 858 return rc; 859 } 860 861 static int 862 ecryptfs_permission(struct inode *inode, int mask, struct nameidata *nd) 863 { 864 int rc; 865 866 if (nd) { 867 struct vfsmount *vfsmnt_save = nd->mnt; 868 struct dentry *dentry_save = nd->dentry; 869 870 nd->mnt = ecryptfs_dentry_to_lower_mnt(nd->dentry); 871 nd->dentry = ecryptfs_dentry_to_lower(nd->dentry); 872 rc = permission(ecryptfs_inode_to_lower(inode), mask, nd); 873 nd->mnt = vfsmnt_save; 874 nd->dentry = dentry_save; 875 } else 876 rc = permission(ecryptfs_inode_to_lower(inode), mask, NULL); 877 return rc; 878 } 879 880 /** 881 * ecryptfs_setattr 882 * @dentry: dentry handle to the inode to modify 883 * @ia: Structure with flags of what to change and values 884 * 885 * Updates the metadata of an inode. If the update is to the size 886 * i.e. truncation, then ecryptfs_truncate will handle the size modification 887 * of both the ecryptfs inode and the lower inode. 888 * 889 * All other metadata changes will be passed right to the lower filesystem, 890 * and we will just update our inode to look like the lower. 891 */ 892 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) 893 { 894 int rc = 0; 895 struct dentry *lower_dentry; 896 struct inode *inode; 897 struct inode *lower_inode; 898 struct ecryptfs_crypt_stat *crypt_stat; 899 900 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; 901 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) 902 ecryptfs_init_crypt_stat(crypt_stat); 903 inode = dentry->d_inode; 904 lower_inode = ecryptfs_inode_to_lower(inode); 905 lower_dentry = ecryptfs_dentry_to_lower(dentry); 906 mutex_lock(&crypt_stat->cs_mutex); 907 if (S_ISDIR(dentry->d_inode->i_mode)) 908 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); 909 else if (S_ISREG(dentry->d_inode->i_mode) 910 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED) 911 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) { 912 struct vfsmount *lower_mnt; 913 struct file *lower_file = NULL; 914 struct ecryptfs_mount_crypt_stat *mount_crypt_stat; 915 int lower_flags; 916 917 lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); 918 lower_flags = O_RDONLY; 919 if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, 920 lower_mnt, lower_flags))) { 921 printk(KERN_ERR 922 "Error opening lower file; rc = [%d]\n", rc); 923 mutex_unlock(&crypt_stat->cs_mutex); 924 goto out; 925 } 926 mount_crypt_stat = &ecryptfs_superblock_to_private( 927 dentry->d_sb)->mount_crypt_stat; 928 if ((rc = ecryptfs_read_metadata(dentry, lower_file))) { 929 if (!(mount_crypt_stat->flags 930 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) { 931 rc = -EIO; 932 printk(KERN_WARNING "Attempt to read file that " 933 "is not in a valid eCryptfs format, " 934 "and plaintext passthrough mode is not " 935 "enabled; returning -EIO\n"); 936 937 mutex_unlock(&crypt_stat->cs_mutex); 938 fput(lower_file); 939 goto out; 940 } 941 rc = 0; 942 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); 943 mutex_unlock(&crypt_stat->cs_mutex); 944 fput(lower_file); 945 goto out; 946 } 947 fput(lower_file); 948 } 949 mutex_unlock(&crypt_stat->cs_mutex); 950 if (ia->ia_valid & ATTR_SIZE) { 951 ecryptfs_printk(KERN_DEBUG, 952 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n", 953 ia->ia_valid, ATTR_SIZE); 954 rc = ecryptfs_truncate(dentry, ia->ia_size); 955 /* ecryptfs_truncate handles resizing of the lower file */ 956 ia->ia_valid &= ~ATTR_SIZE; 957 ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n", 958 ia->ia_valid); 959 if (rc < 0) 960 goto out; 961 } 962 rc = notify_change(lower_dentry, ia); 963 out: 964 fsstack_copy_attr_all(inode, lower_inode, NULL); 965 return rc; 966 } 967 968 int 969 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value, 970 size_t size, int flags) 971 { 972 int rc = 0; 973 struct dentry *lower_dentry; 974 975 lower_dentry = ecryptfs_dentry_to_lower(dentry); 976 if (!lower_dentry->d_inode->i_op->setxattr) { 977 rc = -ENOSYS; 978 goto out; 979 } 980 mutex_lock(&lower_dentry->d_inode->i_mutex); 981 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value, 982 size, flags); 983 mutex_unlock(&lower_dentry->d_inode->i_mutex); 984 out: 985 return rc; 986 } 987 988 ssize_t 989 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value, 990 size_t size) 991 { 992 int rc = 0; 993 struct dentry *lower_dentry; 994 995 lower_dentry = ecryptfs_dentry_to_lower(dentry); 996 if (!lower_dentry->d_inode->i_op->getxattr) { 997 rc = -ENOSYS; 998 goto out; 999 } 1000 mutex_lock(&lower_dentry->d_inode->i_mutex); 1001 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value, 1002 size); 1003 mutex_unlock(&lower_dentry->d_inode->i_mutex); 1004 out: 1005 return rc; 1006 } 1007 1008 static ssize_t 1009 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size) 1010 { 1011 int rc = 0; 1012 struct dentry *lower_dentry; 1013 1014 lower_dentry = ecryptfs_dentry_to_lower(dentry); 1015 if (!lower_dentry->d_inode->i_op->listxattr) { 1016 rc = -ENOSYS; 1017 goto out; 1018 } 1019 mutex_lock(&lower_dentry->d_inode->i_mutex); 1020 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size); 1021 mutex_unlock(&lower_dentry->d_inode->i_mutex); 1022 out: 1023 return rc; 1024 } 1025 1026 static int ecryptfs_removexattr(struct dentry *dentry, const char *name) 1027 { 1028 int rc = 0; 1029 struct dentry *lower_dentry; 1030 1031 lower_dentry = ecryptfs_dentry_to_lower(dentry); 1032 if (!lower_dentry->d_inode->i_op->removexattr) { 1033 rc = -ENOSYS; 1034 goto out; 1035 } 1036 mutex_lock(&lower_dentry->d_inode->i_mutex); 1037 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name); 1038 mutex_unlock(&lower_dentry->d_inode->i_mutex); 1039 out: 1040 return rc; 1041 } 1042 1043 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode) 1044 { 1045 if ((ecryptfs_inode_to_lower(inode) 1046 == (struct inode *)candidate_lower_inode)) 1047 return 1; 1048 else 1049 return 0; 1050 } 1051 1052 int ecryptfs_inode_set(struct inode *inode, void *lower_inode) 1053 { 1054 ecryptfs_init_inode(inode, (struct inode *)lower_inode); 1055 return 0; 1056 } 1057 1058 const struct inode_operations ecryptfs_symlink_iops = { 1059 .readlink = ecryptfs_readlink, 1060 .follow_link = ecryptfs_follow_link, 1061 .put_link = ecryptfs_put_link, 1062 .permission = ecryptfs_permission, 1063 .setattr = ecryptfs_setattr, 1064 .setxattr = ecryptfs_setxattr, 1065 .getxattr = ecryptfs_getxattr, 1066 .listxattr = ecryptfs_listxattr, 1067 .removexattr = ecryptfs_removexattr 1068 }; 1069 1070 const struct inode_operations ecryptfs_dir_iops = { 1071 .create = ecryptfs_create, 1072 .lookup = ecryptfs_lookup, 1073 .link = ecryptfs_link, 1074 .unlink = ecryptfs_unlink, 1075 .symlink = ecryptfs_symlink, 1076 .mkdir = ecryptfs_mkdir, 1077 .rmdir = ecryptfs_rmdir, 1078 .mknod = ecryptfs_mknod, 1079 .rename = ecryptfs_rename, 1080 .permission = ecryptfs_permission, 1081 .setattr = ecryptfs_setattr, 1082 .setxattr = ecryptfs_setxattr, 1083 .getxattr = ecryptfs_getxattr, 1084 .listxattr = ecryptfs_listxattr, 1085 .removexattr = ecryptfs_removexattr 1086 }; 1087 1088 const struct inode_operations ecryptfs_main_iops = { 1089 .permission = ecryptfs_permission, 1090 .setattr = ecryptfs_setattr, 1091 .setxattr = ecryptfs_setxattr, 1092 .getxattr = ecryptfs_getxattr, 1093 .listxattr = ecryptfs_listxattr, 1094 .removexattr = ecryptfs_removexattr 1095 }; 1096