1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 #include <string.h> 20 #include <unistd.h> 21 #include <fcntl.h> 22 #include <ctype.h> 23 #include <sys/mount.h> 24 #include <sys/stat.h> 25 #include <errno.h> 26 #include <sys/types.h> 27 #include <sys/wait.h> 28 #include <libgen.h> 29 #include <time.h> 30 #include <sys/swap.h> 31 32 #include <linux/loop.h> 33 #include <private/android_filesystem_config.h> 34 #include <cutils/android_reboot.h> 35 #include <cutils/partition_utils.h> 36 #include <cutils/properties.h> 37 #include <logwrap/logwrap.h> 38 39 #include "mincrypt/rsa.h" 40 #include "mincrypt/sha.h" 41 #include "mincrypt/sha256.h" 42 43 #include "fs_mgr_priv.h" 44 #include "fs_mgr_priv_verity.h" 45 46 #define KEY_LOC_PROP "ro.crypto.keyfile.userdata" 47 #define KEY_IN_FOOTER "footer" 48 49 #define E2FSCK_BIN "/system/bin/e2fsck" 50 #define F2FS_FSCK_BIN "/system/bin/fsck.f2fs" 51 #define MKSWAP_BIN "/system/bin/mkswap" 52 53 #define FSCK_LOG_FILE "/dev/fscklogs/log" 54 55 #define ZRAM_CONF_DEV "/sys/block/zram0/disksize" 56 57 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a))) 58 59 /* 60 * gettime() - returns the time in seconds of the system's monotonic clock or 61 * zero on error. 62 */ 63 static time_t gettime(void) 64 { 65 struct timespec ts; 66 int ret; 67 68 ret = clock_gettime(CLOCK_MONOTONIC, &ts); 69 if (ret < 0) { 70 ERROR("clock_gettime(CLOCK_MONOTONIC) failed: %s\n", strerror(errno)); 71 return 0; 72 } 73 74 return ts.tv_sec; 75 } 76 77 static int wait_for_file(const char *filename, int timeout) 78 { 79 struct stat info; 80 time_t timeout_time = gettime() + timeout; 81 int ret = -1; 82 83 while (gettime() < timeout_time && ((ret = stat(filename, &info)) < 0)) 84 usleep(10000); 85 86 return ret; 87 } 88 89 static void check_fs(char *blk_device, char *fs_type, char *target) 90 { 91 int status; 92 int ret; 93 long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID; 94 char *tmpmnt_opts = "nomblk_io_submit,errors=remount-ro"; 95 char *e2fsck_argv[] = { 96 E2FSCK_BIN, 97 "-y", 98 blk_device 99 }; 100 101 /* Check for the types of filesystems we know how to check */ 102 if (!strcmp(fs_type, "ext2") || !strcmp(fs_type, "ext3") || !strcmp(fs_type, "ext4")) { 103 /* 104 * First try to mount and unmount the filesystem. We do this because 105 * the kernel is more efficient than e2fsck in running the journal and 106 * processing orphaned inodes, and on at least one device with a 107 * performance issue in the emmc firmware, it can take e2fsck 2.5 minutes 108 * to do what the kernel does in about a second. 109 * 110 * After mounting and unmounting the filesystem, run e2fsck, and if an 111 * error is recorded in the filesystem superblock, e2fsck will do a full 112 * check. Otherwise, it does nothing. If the kernel cannot mount the 113 * filesytsem due to an error, e2fsck is still run to do a full check 114 * fix the filesystem. 115 */ 116 ret = mount(blk_device, target, fs_type, tmpmnt_flags, tmpmnt_opts); 117 INFO("%s(): mount(%s,%s,%s)=%d\n", __func__, blk_device, target, fs_type, ret); 118 if (!ret) { 119 umount(target); 120 } 121 122 /* 123 * Some system images do not have e2fsck for licensing reasons 124 * (e.g. recent SDK system images). Detect these and skip the check. 125 */ 126 if (access(E2FSCK_BIN, X_OK)) { 127 INFO("Not running %s on %s (executable not in system image)\n", 128 E2FSCK_BIN, blk_device); 129 } else { 130 INFO("Running %s on %s\n", E2FSCK_BIN, blk_device); 131 132 ret = android_fork_execvp_ext(ARRAY_SIZE(e2fsck_argv), e2fsck_argv, 133 &status, true, LOG_KLOG | LOG_FILE, 134 true, FSCK_LOG_FILE); 135 136 if (ret < 0) { 137 /* No need to check for error in fork, we can't really handle it now */ 138 ERROR("Failed trying to run %s\n", E2FSCK_BIN); 139 } 140 } 141 } else if (!strcmp(fs_type, "f2fs")) { 142 char *f2fs_fsck_argv[] = { 143 F2FS_FSCK_BIN, 144 blk_device 145 }; 146 INFO("Running %s on %s\n", F2FS_FSCK_BIN, blk_device); 147 148 ret = android_fork_execvp_ext(ARRAY_SIZE(f2fs_fsck_argv), f2fs_fsck_argv, 149 &status, true, LOG_KLOG | LOG_FILE, 150 true, FSCK_LOG_FILE); 151 if (ret < 0) { 152 /* No need to check for error in fork, we can't really handle it now */ 153 ERROR("Failed trying to run %s\n", F2FS_FSCK_BIN); 154 } 155 } 156 157 return; 158 } 159 160 static void remove_trailing_slashes(char *n) 161 { 162 int len; 163 164 len = strlen(n) - 1; 165 while ((*(n + len) == '/') && len) { 166 *(n + len) = '\0'; 167 len--; 168 } 169 } 170 171 /* 172 * Mark the given block device as read-only, using the BLKROSET ioctl. 173 * Return 0 on success, and -1 on error. 174 */ 175 static void fs_set_blk_ro(const char *blockdev) 176 { 177 int fd; 178 int ON = 1; 179 180 fd = open(blockdev, O_RDONLY); 181 if (fd < 0) { 182 // should never happen 183 return; 184 } 185 186 ioctl(fd, BLKROSET, &ON); 187 close(fd); 188 } 189 190 /* 191 * __mount(): wrapper around the mount() system call which also 192 * sets the underlying block device to read-only if the mount is read-only. 193 * See "man 2 mount" for return values. 194 */ 195 static int __mount(const char *source, const char *target, const struct fstab_rec *rec) 196 { 197 unsigned long mountflags = rec->flags; 198 int ret; 199 int save_errno; 200 201 /* We need this because sometimes we have legacy symlinks 202 * that are lingering around and need cleaning up. 203 */ 204 struct stat info; 205 if (!lstat(target, &info)) 206 if ((info.st_mode & S_IFMT) == S_IFLNK) 207 unlink(target); 208 mkdir(target, 0755); 209 ret = mount(source, target, rec->fs_type, mountflags, rec->fs_options); 210 save_errno = errno; 211 INFO("%s(source=%s,target=%s,type=%s)=%d\n", __func__, source, target, rec->fs_type, ret); 212 if ((ret == 0) && (mountflags & MS_RDONLY) != 0) { 213 fs_set_blk_ro(source); 214 } 215 errno = save_errno; 216 return ret; 217 } 218 219 static int fs_match(char *in1, char *in2) 220 { 221 char *n1; 222 char *n2; 223 int ret; 224 225 n1 = strdup(in1); 226 n2 = strdup(in2); 227 228 remove_trailing_slashes(n1); 229 remove_trailing_slashes(n2); 230 231 ret = !strcmp(n1, n2); 232 233 free(n1); 234 free(n2); 235 236 return ret; 237 } 238 239 static int device_is_debuggable() { 240 int ret = -1; 241 char value[PROP_VALUE_MAX]; 242 ret = __system_property_get("ro.debuggable", value); 243 if (ret < 0) 244 return ret; 245 return strcmp(value, "1") ? 0 : 1; 246 } 247 248 /* 249 * Tries to mount any of the consecutive fstab entries that match 250 * the mountpoint of the one given by fstab->recs[start_idx]. 251 * 252 * end_idx: On return, will be the last rec that was looked at. 253 * attempted_idx: On return, will indicate which fstab rec 254 * succeeded. In case of failure, it will be the start_idx. 255 * Returns 256 * -1 on failure with errno set to match the 1st mount failure. 257 * 0 on success. 258 */ 259 static int mount_with_alternatives(struct fstab *fstab, int start_idx, int *end_idx, int *attempted_idx) 260 { 261 int i; 262 int mount_errno = 0; 263 int mounted = 0; 264 265 if (!end_idx || !attempted_idx || start_idx >= fstab->num_entries) { 266 errno = EINVAL; 267 if (end_idx) *end_idx = start_idx; 268 if (attempted_idx) *end_idx = start_idx; 269 return -1; 270 } 271 272 /* Hunt down an fstab entry for the same mount point that might succeed */ 273 for (i = start_idx; 274 /* We required that fstab entries for the same mountpoint be consecutive */ 275 i < fstab->num_entries && !strcmp(fstab->recs[start_idx].mount_point, fstab->recs[i].mount_point); 276 i++) { 277 /* 278 * Don't try to mount/encrypt the same mount point again. 279 * Deal with alternate entries for the same point which are required to be all following 280 * each other. 281 */ 282 if (mounted) { 283 ERROR("%s(): skipping fstab dup mountpoint=%s rec[%d].fs_type=%s already mounted as %s.\n", __func__, 284 fstab->recs[i].mount_point, i, fstab->recs[i].fs_type, fstab->recs[*attempted_idx].fs_type); 285 continue; 286 } 287 288 if (fstab->recs[i].fs_mgr_flags & MF_CHECK) { 289 check_fs(fstab->recs[i].blk_device, fstab->recs[i].fs_type, 290 fstab->recs[i].mount_point); 291 } 292 if (!__mount(fstab->recs[i].blk_device, fstab->recs[i].mount_point, &fstab->recs[i])) { 293 *attempted_idx = i; 294 mounted = 1; 295 if (i != start_idx) { 296 ERROR("%s(): Mounted %s on %s with fs_type=%s instead of %s\n", __func__, 297 fstab->recs[i].blk_device, fstab->recs[i].mount_point, fstab->recs[i].fs_type, 298 fstab->recs[start_idx].fs_type); 299 } 300 } else { 301 /* back up errno for crypto decisions */ 302 mount_errno = errno; 303 } 304 } 305 306 /* Adjust i for the case where it was still withing the recs[] */ 307 if (i < fstab->num_entries) --i; 308 309 *end_idx = i; 310 if (!mounted) { 311 *attempted_idx = start_idx; 312 errno = mount_errno; 313 return -1; 314 } 315 return 0; 316 } 317 318 /* When multiple fstab records share the same mount_point, it will 319 * try to mount each one in turn, and ignore any duplicates after a 320 * first successful mount. 321 * Returns -1 on error, and FS_MGR_MNTALL_* otherwise. 322 */ 323 int fs_mgr_mount_all(struct fstab *fstab) 324 { 325 int i = 0; 326 int encryptable = FS_MGR_MNTALL_DEV_NOT_ENCRYPTED; 327 int error_count = 0; 328 int mret = -1; 329 int mount_errno = 0; 330 int attempted_idx = -1; 331 332 if (!fstab) { 333 return -1; 334 } 335 336 for (i = 0; i < fstab->num_entries; i++) { 337 /* Don't mount entries that are managed by vold */ 338 if (fstab->recs[i].fs_mgr_flags & (MF_VOLDMANAGED | MF_RECOVERYONLY)) { 339 continue; 340 } 341 342 /* Skip swap and raw partition entries such as boot, recovery, etc */ 343 if (!strcmp(fstab->recs[i].fs_type, "swap") || 344 !strcmp(fstab->recs[i].fs_type, "emmc") || 345 !strcmp(fstab->recs[i].fs_type, "mtd")) { 346 continue; 347 } 348 349 if (fstab->recs[i].fs_mgr_flags & MF_WAIT) { 350 wait_for_file(fstab->recs[i].blk_device, WAIT_TIMEOUT); 351 } 352 353 if ((fstab->recs[i].fs_mgr_flags & MF_VERIFY) && 354 !device_is_debuggable()) { 355 if (fs_mgr_setup_verity(&fstab->recs[i]) < 0) { 356 ERROR("Could not set up verified partition, skipping!\n"); 357 continue; 358 } 359 } 360 int last_idx_inspected; 361 mret = mount_with_alternatives(fstab, i, &last_idx_inspected, &attempted_idx); 362 i = last_idx_inspected; 363 mount_errno = errno; 364 365 /* Deal with encryptability. */ 366 if (!mret) { 367 /* If this is encryptable, need to trigger encryption */ 368 if ((fstab->recs[attempted_idx].fs_mgr_flags & MF_FORCECRYPT)) { 369 if (umount(fstab->recs[attempted_idx].mount_point) == 0) { 370 if (encryptable == FS_MGR_MNTALL_DEV_NOT_ENCRYPTED) { 371 ERROR("Will try to encrypt %s %s\n", fstab->recs[attempted_idx].mount_point, 372 fstab->recs[attempted_idx].fs_type); 373 encryptable = FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION; 374 } else { 375 ERROR("Only one encryptable/encrypted partition supported\n"); 376 encryptable = FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED; 377 } 378 } else { 379 INFO("Could not umount %s - allow continue unencrypted\n", 380 fstab->recs[attempted_idx].mount_point); 381 continue; 382 } 383 } 384 /* Success! Go get the next one */ 385 continue; 386 } 387 388 /* mount(2) returned an error, check if it's encryptable and deal with it */ 389 if (mret && mount_errno != EBUSY && mount_errno != EACCES && 390 fs_mgr_is_encryptable(&fstab->recs[attempted_idx])) { 391 if(partition_wiped(fstab->recs[attempted_idx].blk_device)) { 392 ERROR("%s(): %s is wiped and %s %s is encryptable. Suggest recovery...\n", __func__, 393 fstab->recs[attempted_idx].blk_device, fstab->recs[attempted_idx].mount_point, 394 fstab->recs[attempted_idx].fs_type); 395 encryptable = FS_MGR_MNTALL_DEV_NEEDS_RECOVERY; 396 continue; 397 } else { 398 /* Need to mount a tmpfs at this mountpoint for now, and set 399 * properties that vold will query later for decrypting 400 */ 401 ERROR("%s(): possibly an encryptable blkdev %s for mount %s type %s )\n", __func__, 402 fstab->recs[attempted_idx].blk_device, fstab->recs[attempted_idx].mount_point, 403 fstab->recs[attempted_idx].fs_type); 404 if (fs_mgr_do_tmpfs_mount(fstab->recs[attempted_idx].mount_point) < 0) { 405 ++error_count; 406 continue; 407 } 408 } 409 encryptable = FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED; 410 } else { 411 ERROR("Failed to mount an un-encryptable or wiped partition on" 412 "%s at %s options: %s error: %s\n", 413 fstab->recs[attempted_idx].blk_device, fstab->recs[attempted_idx].mount_point, 414 fstab->recs[attempted_idx].fs_options, strerror(mount_errno)); 415 ++error_count; 416 continue; 417 } 418 } 419 420 if (error_count) { 421 return -1; 422 } else { 423 return encryptable; 424 } 425 } 426 427 /* If tmp_mount_point is non-null, mount the filesystem there. This is for the 428 * tmp mount we do to check the user password 429 * If multiple fstab entries are to be mounted on "n_name", it will try to mount each one 430 * in turn, and stop on 1st success, or no more match. 431 */ 432 int fs_mgr_do_mount(struct fstab *fstab, char *n_name, char *n_blk_device, 433 char *tmp_mount_point) 434 { 435 int i = 0; 436 int ret = FS_MGR_DOMNT_FAILED; 437 int mount_errors = 0; 438 int first_mount_errno = 0; 439 char *m; 440 441 if (!fstab) { 442 return ret; 443 } 444 445 for (i = 0; i < fstab->num_entries; i++) { 446 if (!fs_match(fstab->recs[i].mount_point, n_name)) { 447 continue; 448 } 449 450 /* We found our match */ 451 /* If this swap or a raw partition, report an error */ 452 if (!strcmp(fstab->recs[i].fs_type, "swap") || 453 !strcmp(fstab->recs[i].fs_type, "emmc") || 454 !strcmp(fstab->recs[i].fs_type, "mtd")) { 455 ERROR("Cannot mount filesystem of type %s on %s\n", 456 fstab->recs[i].fs_type, n_blk_device); 457 goto out; 458 } 459 460 /* First check the filesystem if requested */ 461 if (fstab->recs[i].fs_mgr_flags & MF_WAIT) { 462 wait_for_file(n_blk_device, WAIT_TIMEOUT); 463 } 464 465 if (fstab->recs[i].fs_mgr_flags & MF_CHECK) { 466 check_fs(n_blk_device, fstab->recs[i].fs_type, 467 fstab->recs[i].mount_point); 468 } 469 470 if ((fstab->recs[i].fs_mgr_flags & MF_VERIFY) && 471 !device_is_debuggable()) { 472 if (fs_mgr_setup_verity(&fstab->recs[i]) < 0) { 473 ERROR("Could not set up verified partition, skipping!\n"); 474 continue; 475 } 476 } 477 478 /* Now mount it where requested */ 479 if (tmp_mount_point) { 480 m = tmp_mount_point; 481 } else { 482 m = fstab->recs[i].mount_point; 483 } 484 if (__mount(n_blk_device, m, &fstab->recs[i])) { 485 if (!first_mount_errno) first_mount_errno = errno; 486 mount_errors++; 487 continue; 488 } else { 489 ret = 0; 490 goto out; 491 } 492 } 493 if (mount_errors) { 494 ERROR("Cannot mount filesystem on %s at %s. error: %s\n", 495 n_blk_device, m, strerror(first_mount_errno)); 496 if (first_mount_errno == EBUSY) { 497 ret = FS_MGR_DOMNT_BUSY; 498 } else { 499 ret = FS_MGR_DOMNT_FAILED; 500 } 501 } else { 502 /* We didn't find a match, say so and return an error */ 503 ERROR("Cannot find mount point %s in fstab\n", fstab->recs[i].mount_point); 504 } 505 506 out: 507 return ret; 508 } 509 510 /* 511 * mount a tmpfs filesystem at the given point. 512 * return 0 on success, non-zero on failure. 513 */ 514 int fs_mgr_do_tmpfs_mount(char *n_name) 515 { 516 int ret; 517 518 ret = mount("tmpfs", n_name, "tmpfs", 519 MS_NOATIME | MS_NOSUID | MS_NODEV, CRYPTO_TMPFS_OPTIONS); 520 if (ret < 0) { 521 ERROR("Cannot mount tmpfs filesystem at %s\n", n_name); 522 return -1; 523 } 524 525 /* Success */ 526 return 0; 527 } 528 529 int fs_mgr_unmount_all(struct fstab *fstab) 530 { 531 int i = 0; 532 int ret = 0; 533 534 if (!fstab) { 535 return -1; 536 } 537 538 while (fstab->recs[i].blk_device) { 539 if (umount(fstab->recs[i].mount_point)) { 540 ERROR("Cannot unmount filesystem at %s\n", fstab->recs[i].mount_point); 541 ret = -1; 542 } 543 i++; 544 } 545 546 return ret; 547 } 548 549 /* This must be called after mount_all, because the mkswap command needs to be 550 * available. 551 */ 552 int fs_mgr_swapon_all(struct fstab *fstab) 553 { 554 int i = 0; 555 int flags = 0; 556 int err = 0; 557 int ret = 0; 558 int status; 559 char *mkswap_argv[2] = { 560 MKSWAP_BIN, 561 NULL 562 }; 563 564 if (!fstab) { 565 return -1; 566 } 567 568 for (i = 0; i < fstab->num_entries; i++) { 569 /* Skip non-swap entries */ 570 if (strcmp(fstab->recs[i].fs_type, "swap")) { 571 continue; 572 } 573 574 if (fstab->recs[i].zram_size > 0) { 575 /* A zram_size was specified, so we need to configure the 576 * device. There is no point in having multiple zram devices 577 * on a system (all the memory comes from the same pool) so 578 * we can assume the device number is 0. 579 */ 580 FILE *zram_fp; 581 582 zram_fp = fopen(ZRAM_CONF_DEV, "r+"); 583 if (zram_fp == NULL) { 584 ERROR("Unable to open zram conf device %s\n", ZRAM_CONF_DEV); 585 ret = -1; 586 continue; 587 } 588 fprintf(zram_fp, "%d\n", fstab->recs[i].zram_size); 589 fclose(zram_fp); 590 } 591 592 if (fstab->recs[i].fs_mgr_flags & MF_WAIT) { 593 wait_for_file(fstab->recs[i].blk_device, WAIT_TIMEOUT); 594 } 595 596 /* Initialize the swap area */ 597 mkswap_argv[1] = fstab->recs[i].blk_device; 598 err = android_fork_execvp_ext(ARRAY_SIZE(mkswap_argv), mkswap_argv, 599 &status, true, LOG_KLOG, false, NULL); 600 if (err) { 601 ERROR("mkswap failed for %s\n", fstab->recs[i].blk_device); 602 ret = -1; 603 continue; 604 } 605 606 /* If -1, then no priority was specified in fstab, so don't set 607 * SWAP_FLAG_PREFER or encode the priority */ 608 if (fstab->recs[i].swap_prio >= 0) { 609 flags = (fstab->recs[i].swap_prio << SWAP_FLAG_PRIO_SHIFT) & 610 SWAP_FLAG_PRIO_MASK; 611 flags |= SWAP_FLAG_PREFER; 612 } else { 613 flags = 0; 614 } 615 err = swapon(fstab->recs[i].blk_device, flags); 616 if (err) { 617 ERROR("swapon failed for %s\n", fstab->recs[i].blk_device); 618 ret = -1; 619 } 620 } 621 622 return ret; 623 } 624 625 /* 626 * key_loc must be at least PROPERTY_VALUE_MAX bytes long 627 * 628 * real_blk_device must be at least PROPERTY_VALUE_MAX bytes long 629 */ 630 int fs_mgr_get_crypt_info(struct fstab *fstab, char *key_loc, char *real_blk_device, int size) 631 { 632 int i = 0; 633 634 if (!fstab) { 635 return -1; 636 } 637 /* Initialize return values to null strings */ 638 if (key_loc) { 639 *key_loc = '\0'; 640 } 641 if (real_blk_device) { 642 *real_blk_device = '\0'; 643 } 644 645 /* Look for the encryptable partition to find the data */ 646 for (i = 0; i < fstab->num_entries; i++) { 647 /* Don't deal with vold managed enryptable partitions here */ 648 if (fstab->recs[i].fs_mgr_flags & MF_VOLDMANAGED) { 649 continue; 650 } 651 if (!(fstab->recs[i].fs_mgr_flags & (MF_CRYPT | MF_FORCECRYPT))) { 652 continue; 653 } 654 655 /* We found a match */ 656 if (key_loc) { 657 strlcpy(key_loc, fstab->recs[i].key_loc, size); 658 } 659 if (real_blk_device) { 660 strlcpy(real_blk_device, fstab->recs[i].blk_device, size); 661 } 662 break; 663 } 664 665 return 0; 666 } 667
