Volume.cpp revision 9092b1dbd31406f6939045fbef70a297b8dbeb62
1/* 2 * Copyright (C) 2008 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 <stdlib.h> 18#include <string.h> 19#include <dirent.h> 20#include <errno.h> 21#include <fcntl.h> 22 23#include <sys/types.h> 24#include <sys/stat.h> 25#include <sys/types.h> 26#include <sys/mman.h> 27#include <sys/mount.h> 28 29#include <linux/kdev_t.h> 30#include <linux/fs.h> 31 32#include <cutils/properties.h> 33 34#include <diskconfig/diskconfig.h> 35 36#include <private/android_filesystem_config.h> 37 38#define LOG_TAG "Vold" 39 40#include <cutils/log.h> 41 42#include "Volume.h" 43#include "VolumeManager.h" 44#include "ResponseCode.h" 45#include "Fat.h" 46#include "Process.h" 47 48extern "C" void dos_partition_dec(void const *pp, struct dos_partition *d); 49extern "C" void dos_partition_enc(void *pp, struct dos_partition *d); 50 51 52/* 53 * Secure directory - stuff that only root can see 54 */ 55const char *Volume::SECDIR = "/mnt/secure"; 56 57/* 58 * Secure staging directory - where media is mounted for preparation 59 */ 60const char *Volume::SEC_STGDIR = "/mnt/secure/staging"; 61 62/* 63 * Path to the directory on the media which contains publicly accessable 64 * asec imagefiles. This path will be obscured before the mount is 65 * exposed to non priviledged users. 66 */ 67const char *Volume::SEC_STG_SECIMGDIR = "/mnt/secure/staging/.android_secure"; 68 69/* 70 * Path to where *only* root can access asec imagefiles 71 */ 72const char *Volume::SEC_ASECDIR = "/mnt/secure/asec"; 73 74/* 75 * Path to where secure containers are mounted 76 */ 77const char *Volume::ASECDIR = "/mnt/asec"; 78 79/* 80 * Path to where OBBs are mounted 81 */ 82const char *Volume::LOOPDIR = "/mnt/obb"; 83 84static const char *stateToStr(int state) { 85 if (state == Volume::State_Init) 86 return "Initializing"; 87 else if (state == Volume::State_NoMedia) 88 return "No-Media"; 89 else if (state == Volume::State_Idle) 90 return "Idle-Unmounted"; 91 else if (state == Volume::State_Pending) 92 return "Pending"; 93 else if (state == Volume::State_Mounted) 94 return "Mounted"; 95 else if (state == Volume::State_Unmounting) 96 return "Unmounting"; 97 else if (state == Volume::State_Checking) 98 return "Checking"; 99 else if (state == Volume::State_Formatting) 100 return "Formatting"; 101 else if (state == Volume::State_Shared) 102 return "Shared-Unmounted"; 103 else if (state == Volume::State_SharedMnt) 104 return "Shared-Mounted"; 105 else 106 return "Unknown-Error"; 107} 108 109Volume::Volume(VolumeManager *vm, const char *label, const char *mount_point) { 110 mVm = vm; 111 mDebug = false; 112 mLabel = strdup(label); 113 mMountpoint = strdup(mount_point); 114 mState = Volume::State_Init; 115 mCurrentlyMountedKdev = -1; 116 mPartIdx = -1; 117} 118 119Volume::~Volume() { 120 free(mLabel); 121 free(mMountpoint); 122} 123 124void Volume::protectFromAutorunStupidity() { 125 char filename[255]; 126 127 snprintf(filename, sizeof(filename), "%s/autorun.inf", SEC_STGDIR); 128 if (!access(filename, F_OK)) { 129 SLOGW("Volume contains an autorun.inf! - removing"); 130 /* 131 * Ensure the filename is all lower-case so 132 * the process killer can find the inode. 133 * Probably being paranoid here but meh. 134 */ 135 rename(filename, filename); 136 Process::killProcessesWithOpenFiles(filename, 2); 137 if (unlink(filename)) { 138 SLOGE("Failed to remove %s (%s)", filename, strerror(errno)); 139 } 140 } 141} 142 143void Volume::setDebug(bool enable) { 144 mDebug = enable; 145} 146 147dev_t Volume::getDiskDevice() { 148 return MKDEV(0, 0); 149}; 150 151dev_t Volume::getShareDevice() { 152 return getDiskDevice(); 153} 154 155void Volume::handleVolumeShared() { 156} 157 158void Volume::handleVolumeUnshared() { 159} 160 161int Volume::handleBlockEvent(NetlinkEvent *evt) { 162 errno = ENOSYS; 163 return -1; 164} 165 166void Volume::setState(int state) { 167 char msg[255]; 168 int oldState = mState; 169 170 if (oldState == state) { 171 SLOGW("Duplicate state (%d)\n", state); 172 return; 173 } 174 175 mState = state; 176 177 SLOGD("Volume %s state changing %d (%s) -> %d (%s)", mLabel, 178 oldState, stateToStr(oldState), mState, stateToStr(mState)); 179 snprintf(msg, sizeof(msg), 180 "Volume %s %s state changed from %d (%s) to %d (%s)", getLabel(), 181 getMountpoint(), oldState, stateToStr(oldState), mState, 182 stateToStr(mState)); 183 184 mVm->getBroadcaster()->sendBroadcast(ResponseCode::VolumeStateChange, 185 msg, false); 186} 187 188int Volume::createDeviceNode(const char *path, int major, int minor) { 189 mode_t mode = 0660 | S_IFBLK; 190 dev_t dev = (major << 8) | minor; 191 if (mknod(path, mode, dev) < 0) { 192 if (errno != EEXIST) { 193 return -1; 194 } 195 } 196 return 0; 197} 198 199int Volume::formatVol() { 200 201 if (getState() == Volume::State_NoMedia) { 202 errno = ENODEV; 203 return -1; 204 } else if (getState() != Volume::State_Idle) { 205 errno = EBUSY; 206 return -1; 207 } 208 209 if (isMountpointMounted(getMountpoint())) { 210 SLOGW("Volume is idle but appears to be mounted - fixing"); 211 setState(Volume::State_Mounted); 212 // mCurrentlyMountedKdev = XXX 213 errno = EBUSY; 214 return -1; 215 } 216 217 bool formatEntireDevice = (mPartIdx == -1); 218 char devicePath[255]; 219 dev_t diskNode = getDiskDevice(); 220 dev_t partNode = MKDEV(MAJOR(diskNode), (formatEntireDevice ? 1 : mPartIdx)); 221 222 setState(Volume::State_Formatting); 223 224 int ret = -1; 225 // Only initialize the MBR if we are formatting the entire device 226 if (formatEntireDevice) { 227 sprintf(devicePath, "/dev/block/vold/%d:%d", 228 MAJOR(diskNode), MINOR(diskNode)); 229 230 if (initializeMbr(devicePath)) { 231 SLOGE("Failed to initialize MBR (%s)", strerror(errno)); 232 goto err; 233 } 234 } 235 236 sprintf(devicePath, "/dev/block/vold/%d:%d", 237 MAJOR(partNode), MINOR(partNode)); 238 239 if (mDebug) { 240 SLOGI("Formatting volume %s (%s)", getLabel(), devicePath); 241 } 242 243 if (Fat::format(devicePath, 0)) { 244 SLOGE("Failed to format (%s)", strerror(errno)); 245 goto err; 246 } 247 248 ret = 0; 249 250err: 251 setState(Volume::State_Idle); 252 return ret; 253} 254 255bool Volume::isMountpointMounted(const char *path) { 256 char device[256]; 257 char mount_path[256]; 258 char rest[256]; 259 FILE *fp; 260 char line[1024]; 261 262 if (!(fp = fopen("/proc/mounts", "r"))) { 263 SLOGE("Error opening /proc/mounts (%s)", strerror(errno)); 264 return false; 265 } 266 267 while(fgets(line, sizeof(line), fp)) { 268 line[strlen(line)-1] = '\0'; 269 sscanf(line, "%255s %255s %255s\n", device, mount_path, rest); 270 if (!strcmp(mount_path, path)) { 271 fclose(fp); 272 return true; 273 } 274 275 } 276 277 fclose(fp); 278 return false; 279} 280 281int Volume::mountVol() { 282 dev_t deviceNodes[4]; 283 int n, i, rc = 0; 284 char errmsg[255]; 285 286 if (getState() == Volume::State_NoMedia) { 287 snprintf(errmsg, sizeof(errmsg), 288 "Volume %s %s mount failed - no media", 289 getLabel(), getMountpoint()); 290 mVm->getBroadcaster()->sendBroadcast( 291 ResponseCode::VolumeMountFailedNoMedia, 292 errmsg, false); 293 errno = ENODEV; 294 return -1; 295 } else if (getState() != Volume::State_Idle) { 296 errno = EBUSY; 297 return -1; 298 } 299 300 if (isMountpointMounted(getMountpoint())) { 301 SLOGW("Volume is idle but appears to be mounted - fixing"); 302 setState(Volume::State_Mounted); 303 // mCurrentlyMountedKdev = XXX 304 return 0; 305 } 306 307 n = getDeviceNodes((dev_t *) &deviceNodes, 4); 308 if (!n) { 309 SLOGE("Failed to get device nodes (%s)\n", strerror(errno)); 310 return -1; 311 } 312 313 for (i = 0; i < n; i++) { 314 char devicePath[255]; 315 316 sprintf(devicePath, "/dev/block/vold/%d:%d", MAJOR(deviceNodes[i]), 317 MINOR(deviceNodes[i])); 318 319 SLOGI("%s being considered for volume %s\n", devicePath, getLabel()); 320 321 errno = 0; 322 setState(Volume::State_Checking); 323 324 if (Fat::check(devicePath)) { 325 if (errno == ENODATA) { 326 SLOGW("%s does not contain a FAT filesystem\n", devicePath); 327 continue; 328 } 329 errno = EIO; 330 /* Badness - abort the mount */ 331 SLOGE("%s failed FS checks (%s)", devicePath, strerror(errno)); 332 setState(Volume::State_Idle); 333 return -1; 334 } 335 336 /* 337 * Mount the device on our internal staging mountpoint so we can 338 * muck with it before exposing it to non priviledged users. 339 */ 340 errno = 0; 341 int gid; 342 343 if (!strcmp(getMountpoint(), "/mnt/sdcard")) { 344 // Special case the primary SD card. 345 // For this we grant write access to the SDCARD_RW group. 346 gid = AID_SDCARD_RW; 347 } else { 348 // For secondary external storage we keep things locked up. 349 gid = AID_MEDIA_RW; 350 } 351 if (Fat::doMount(devicePath, "/mnt/secure/staging", false, false, false, 352 AID_SYSTEM, gid, 0702, true)) { 353 SLOGE("%s failed to mount via VFAT (%s)\n", devicePath, strerror(errno)); 354 continue; 355 } 356 357 SLOGI("Device %s, target %s mounted @ /mnt/secure/staging", devicePath, getMountpoint()); 358 359 protectFromAutorunStupidity(); 360 361 if (createBindMounts()) { 362 SLOGE("Failed to create bindmounts (%s)", strerror(errno)); 363 umount("/mnt/secure/staging"); 364 setState(Volume::State_Idle); 365 return -1; 366 } 367 368 /* 369 * Now that the bindmount trickery is done, atomically move the 370 * whole subtree to expose it to non priviledged users. 371 */ 372 if (doMoveMount("/mnt/secure/staging", getMountpoint(), false)) { 373 SLOGE("Failed to move mount (%s)", strerror(errno)); 374 umount("/mnt/secure/staging"); 375 setState(Volume::State_Idle); 376 return -1; 377 } 378 setState(Volume::State_Mounted); 379 mCurrentlyMountedKdev = deviceNodes[i]; 380 return 0; 381 } 382 383 SLOGE("Volume %s found no suitable devices for mounting :(\n", getLabel()); 384 setState(Volume::State_Idle); 385 386 return -1; 387} 388 389int Volume::createBindMounts() { 390 unsigned long flags; 391 392 /* 393 * Rename old /android_secure -> /.android_secure 394 */ 395 if (!access("/mnt/secure/staging/android_secure", R_OK | X_OK) && 396 access(SEC_STG_SECIMGDIR, R_OK | X_OK)) { 397 if (rename("/mnt/secure/staging/android_secure", SEC_STG_SECIMGDIR)) { 398 SLOGE("Failed to rename legacy asec dir (%s)", strerror(errno)); 399 } 400 } 401 402 /* 403 * Ensure that /android_secure exists and is a directory 404 */ 405 if (access(SEC_STG_SECIMGDIR, R_OK | X_OK)) { 406 if (errno == ENOENT) { 407 if (mkdir(SEC_STG_SECIMGDIR, 0777)) { 408 SLOGE("Failed to create %s (%s)", SEC_STG_SECIMGDIR, strerror(errno)); 409 return -1; 410 } 411 } else { 412 SLOGE("Failed to access %s (%s)", SEC_STG_SECIMGDIR, strerror(errno)); 413 return -1; 414 } 415 } else { 416 struct stat sbuf; 417 418 if (stat(SEC_STG_SECIMGDIR, &sbuf)) { 419 SLOGE("Failed to stat %s (%s)", SEC_STG_SECIMGDIR, strerror(errno)); 420 return -1; 421 } 422 if (!S_ISDIR(sbuf.st_mode)) { 423 SLOGE("%s is not a directory", SEC_STG_SECIMGDIR); 424 errno = ENOTDIR; 425 return -1; 426 } 427 } 428 429 /* 430 * Bind mount /mnt/secure/staging/android_secure -> /mnt/secure/asec so we'll 431 * have a root only accessable mountpoint for it. 432 */ 433 if (mount(SEC_STG_SECIMGDIR, SEC_ASECDIR, "", MS_BIND, NULL)) { 434 SLOGE("Failed to bind mount points %s -> %s (%s)", 435 SEC_STG_SECIMGDIR, SEC_ASECDIR, strerror(errno)); 436 return -1; 437 } 438 439 /* 440 * Mount a read-only, zero-sized tmpfs on <mountpoint>/android_secure to 441 * obscure the underlying directory from everybody - sneaky eh? ;) 442 */ 443 if (mount("tmpfs", SEC_STG_SECIMGDIR, "tmpfs", MS_RDONLY, "size=0,mode=000,uid=0,gid=0")) { 444 SLOGE("Failed to obscure %s (%s)", SEC_STG_SECIMGDIR, strerror(errno)); 445 umount("/mnt/asec_secure"); 446 return -1; 447 } 448 449 return 0; 450} 451 452int Volume::doMoveMount(const char *src, const char *dst, bool force) { 453 unsigned int flags = MS_MOVE; 454 int retries = 5; 455 456 while(retries--) { 457 if (!mount(src, dst, "", flags, NULL)) { 458 if (mDebug) { 459 SLOGD("Moved mount %s -> %s sucessfully", src, dst); 460 } 461 return 0; 462 } else if (errno != EBUSY) { 463 SLOGE("Failed to move mount %s -> %s (%s)", src, dst, strerror(errno)); 464 return -1; 465 } 466 int action = 0; 467 468 if (force) { 469 if (retries == 1) { 470 action = 2; // SIGKILL 471 } else if (retries == 2) { 472 action = 1; // SIGHUP 473 } 474 } 475 SLOGW("Failed to move %s -> %s (%s, retries %d, action %d)", 476 src, dst, strerror(errno), retries, action); 477 Process::killProcessesWithOpenFiles(src, action); 478 usleep(1000*250); 479 } 480 481 errno = EBUSY; 482 SLOGE("Giving up on move %s -> %s (%s)", src, dst, strerror(errno)); 483 return -1; 484} 485 486int Volume::doUnmount(const char *path, bool force) { 487 int retries = 10; 488 489 if (mDebug) { 490 SLOGD("Unmounting {%s}, force = %d", path, force); 491 } 492 493 while (retries--) { 494 if (!umount(path) || errno == EINVAL || errno == ENOENT) { 495 SLOGI("%s sucessfully unmounted", path); 496 return 0; 497 } 498 499 int action = 0; 500 501 if (force) { 502 if (retries == 1) { 503 action = 2; // SIGKILL 504 } else if (retries == 2) { 505 action = 1; // SIGHUP 506 } 507 } 508 509 SLOGW("Failed to unmount %s (%s, retries %d, action %d)", 510 path, strerror(errno), retries, action); 511 512 Process::killProcessesWithOpenFiles(path, action); 513 usleep(1000*1000); 514 } 515 errno = EBUSY; 516 SLOGE("Giving up on unmount %s (%s)", path, strerror(errno)); 517 return -1; 518} 519 520int Volume::unmountVol(bool force) { 521 int i, rc; 522 523 if (getState() != Volume::State_Mounted) { 524 SLOGE("Volume %s unmount request when not mounted", getLabel()); 525 errno = EINVAL; 526 return -1; 527 } 528 529 setState(Volume::State_Unmounting); 530 usleep(1000 * 1000); // Give the framework some time to react 531 532 /* 533 * First move the mountpoint back to our internal staging point 534 * so nobody else can muck with it while we work. 535 */ 536 if (doMoveMount(getMountpoint(), SEC_STGDIR, force)) { 537 SLOGE("Failed to move mount %s => %s (%s)", getMountpoint(), SEC_STGDIR, strerror(errno)); 538 setState(Volume::State_Mounted); 539 return -1; 540 } 541 542 protectFromAutorunStupidity(); 543 544 /* 545 * Unmount the tmpfs which was obscuring the asec image directory 546 * from non root users 547 */ 548 549 if (doUnmount(Volume::SEC_STG_SECIMGDIR, force)) { 550 SLOGE("Failed to unmount tmpfs on %s (%s)", SEC_STG_SECIMGDIR, strerror(errno)); 551 goto fail_republish; 552 } 553 554 /* 555 * Remove the bindmount we were using to keep a reference to 556 * the previously obscured directory. 557 */ 558 559 if (doUnmount(Volume::SEC_ASECDIR, force)) { 560 SLOGE("Failed to remove bindmount on %s (%s)", SEC_ASECDIR, strerror(errno)); 561 goto fail_remount_tmpfs; 562 } 563 564 /* 565 * Finally, unmount the actual block device from the staging dir 566 */ 567 if (doUnmount(Volume::SEC_STGDIR, force)) { 568 SLOGE("Failed to unmount %s (%s)", SEC_STGDIR, strerror(errno)); 569 goto fail_recreate_bindmount; 570 } 571 572 SLOGI("%s unmounted sucessfully", getMountpoint()); 573 574 setState(Volume::State_Idle); 575 mCurrentlyMountedKdev = -1; 576 return 0; 577 578 /* 579 * Failure handling - try to restore everything back the way it was 580 */ 581fail_recreate_bindmount: 582 if (mount(SEC_STG_SECIMGDIR, SEC_ASECDIR, "", MS_BIND, NULL)) { 583 SLOGE("Failed to restore bindmount after failure! - Storage will appear offline!"); 584 goto out_nomedia; 585 } 586fail_remount_tmpfs: 587 if (mount("tmpfs", SEC_STG_SECIMGDIR, "tmpfs", MS_RDONLY, "size=0,mode=0,uid=0,gid=0")) { 588 SLOGE("Failed to restore tmpfs after failure! - Storage will appear offline!"); 589 goto out_nomedia; 590 } 591fail_republish: 592 if (doMoveMount(SEC_STGDIR, getMountpoint(), force)) { 593 SLOGE("Failed to republish mount after failure! - Storage will appear offline!"); 594 goto out_nomedia; 595 } 596 597 setState(Volume::State_Mounted); 598 return -1; 599 600out_nomedia: 601 setState(Volume::State_NoMedia); 602 return -1; 603} 604int Volume::initializeMbr(const char *deviceNode) { 605 struct disk_info dinfo; 606 607 memset(&dinfo, 0, sizeof(dinfo)); 608 609 if (!(dinfo.part_lst = (struct part_info *) malloc(MAX_NUM_PARTS * sizeof(struct part_info)))) { 610 SLOGE("Failed to malloc prt_lst"); 611 return -1; 612 } 613 614 memset(dinfo.part_lst, 0, MAX_NUM_PARTS * sizeof(struct part_info)); 615 dinfo.device = strdup(deviceNode); 616 dinfo.scheme = PART_SCHEME_MBR; 617 dinfo.sect_size = 512; 618 dinfo.skip_lba = 2048; 619 dinfo.num_lba = 0; 620 dinfo.num_parts = 1; 621 622 struct part_info *pinfo = &dinfo.part_lst[0]; 623 624 pinfo->name = strdup("android_sdcard"); 625 pinfo->flags |= PART_ACTIVE_FLAG; 626 pinfo->type = PC_PART_TYPE_FAT32; 627 pinfo->len_kb = -1; 628 629 int rc = apply_disk_config(&dinfo, 0); 630 631 if (rc) { 632 SLOGE("Failed to apply disk configuration (%d)", rc); 633 goto out; 634 } 635 636 out: 637 free(pinfo->name); 638 free(dinfo.device); 639 free(dinfo.part_lst); 640 641 return rc; 642} 643