Update vold to prepare package sandboxes for primary volume.
Vold is updated to create package specific sandboxes for primary
volume and mount them at
"/mnt/user/<user-id>/package/<package-name>/<primary-label>".
This will later be mounted at /storage when a new process starts.
Bug: 111890351
Test: Manually verified that a package has access to "/sdcard" and
"/storage/emulated/0", both of which are just the package specific
sandboxes and the package doesn't have access to other sandboxes
and can't see other package names.
Change-Id: I72dc8ae9eb2260a298159c5de18387dad2f9de48
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index 049adc8..2b8f8d4 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -64,14 +64,19 @@
#include "model/EmulatedVolume.h"
#include "model/ObbVolume.h"
+using android::base::GetBoolProperty;
+using android::base::StringAppendF;
using android::base::StringPrintf;
using android::base::unique_fd;
static const char* kPathUserMount = "/mnt/user";
static const char* kPathVirtualDisk = "/data/misc/vold/virtual_disk";
+static const char* kIsolatedStorage = "persist.sys.isolated_storage";
static const char* kPropVirtualDisk = "persist.sys.virtual_disk";
+static const std::string kEmptyString("");
+
/* 512MiB is large enough for testing purposes */
static const unsigned int kSizeVirtualDisk = 536870912;
@@ -341,27 +346,189 @@
return success ? 0 : -1;
}
-int VolumeManager::linkPrimary(userid_t userId) {
- std::string source(mPrimary->getPath());
- if (mPrimary->getType() == android::vold::VolumeBase::Type::kEmulated) {
- source = StringPrintf("%s/%d", source.c_str(), userId);
- fs_prepare_dir(source.c_str(), 0755, AID_ROOT, AID_ROOT);
- }
+int VolumeManager::linkPrimary(userid_t userId, const std::vector<std::string>& packageNames) {
+ if (GetBoolProperty(kIsolatedStorage, false)) {
+ std::string source(StringPrintf("/mnt/runtime/write/%s", mPrimary->getLabel().c_str()));
+ bool isPrimaryEmulated =
+ (mPrimary->getType() == android::vold::VolumeBase::Type::kEmulated);
+ if (isPrimaryEmulated) {
+ StringAppendF(&source, "/%d", userId);
+ if (fs_prepare_dir(source.c_str(), 0755, AID_ROOT, AID_ROOT) != 0) {
+ PLOG(ERROR) << "fs_prepare_dir failed on " << source;
+ return -errno;
+ }
+ }
+ return mountSandboxesForPrimaryVol(source, userId, packageNames, isPrimaryEmulated);
+ } else {
+ std::string source(mPrimary->getPath());
+ if (mPrimary->getType() == android::vold::VolumeBase::Type::kEmulated) {
+ source = StringPrintf("%s/%d", source.c_str(), userId);
+ fs_prepare_dir(source.c_str(), 0755, AID_ROOT, AID_ROOT);
+ }
- std::string target(StringPrintf("/mnt/user/%d/primary", userId));
- if (TEMP_FAILURE_RETRY(unlink(target.c_str()))) {
- if (errno != ENOENT) {
- PLOG(WARNING) << "Failed to unlink " << target;
+ std::string target(StringPrintf("/mnt/user/%d/primary", userId));
+ if (TEMP_FAILURE_RETRY(unlink(target.c_str()))) {
+ if (errno != ENOENT) {
+ PLOG(WARNING) << "Failed to unlink " << target;
+ }
+ }
+ LOG(DEBUG) << "Linking " << source << " to " << target;
+ if (TEMP_FAILURE_RETRY(symlink(source.c_str(), target.c_str()))) {
+ PLOG(WARNING) << "Failed to link";
+ return -errno;
}
}
- LOG(DEBUG) << "Linking " << source << " to " << target;
- if (TEMP_FAILURE_RETRY(symlink(source.c_str(), target.c_str()))) {
- PLOG(WARNING) << "Failed to link";
+ return 0;
+}
+
+int VolumeManager::mountSandboxesForPrimaryVol(const std::string& primaryRoot, userid_t userId,
+ const std::vector<std::string>& packageNames, bool isPrimaryEmulated) {
+
+ std::string sandboxRoot = prepareSubDirs(primaryRoot, "Android/sandbox/",
+ 0700, AID_ROOT, AID_ROOT);
+ if (sandboxRoot.empty()) {
return -errno;
}
+
+ std::string dataRoot = prepareSubDirs(primaryRoot, "Android/data/",
+ 0700, AID_ROOT, AID_ROOT);
+ if (dataRoot.empty()) {
+ return -errno;
+ }
+
+ std::string segment = StringPrintf("%d/package/", userId);
+ std::string mntTargetRoot = prepareSubDirs("/mnt/user", segment.c_str(),
+ 0700, AID_ROOT, AID_ROOT);
+ if (mntTargetRoot.empty()) {
+ return -errno;
+ }
+
+ for (auto& packageName : packageNames) {
+ const auto& it = mAppIds.find(packageName);
+ if (it == mAppIds.end()) {
+ PLOG(ERROR) << "appId is not available for " << packageName;
+ continue;
+ }
+ appid_t appId = it->second;
+ std::string sandboxId = mSandboxIds[appId];
+ uid_t uid = multiuser_get_uid(userId, appId);
+
+ // Create [1] /mnt/runtime/write/emulated/0/Android/sandbox/<sandboxId>
+ // Create [2] /mnt/user/0/package/<packageName>/emulated/0
+ // Mount [1] at [2]
+ std::string pkgSandboxSourceDir = prepareSandboxSource(uid, sandboxId, sandboxRoot);
+ if (pkgSandboxSourceDir.empty()) {
+ return -errno;
+ }
+ std::string pkgSandboxTargetDir = prepareSandboxTarget(packageName, uid,
+ mPrimary->getLabel(), mntTargetRoot, isPrimaryEmulated);
+ if (pkgSandboxTargetDir.empty()) {
+ return -errno;
+ }
+ if (TEMP_FAILURE_RETRY(mount(pkgSandboxSourceDir.c_str(), pkgSandboxTargetDir.c_str(),
+ nullptr, MS_BIND | MS_REC | MS_SLAVE, nullptr)) == -1) {
+ PLOG(ERROR) << "Failed to mount " << pkgSandboxSourceDir << " at "
+ << pkgSandboxTargetDir;
+ return -errno;
+ }
+
+ // Create [1] /mnt/runtime/write/emulated/0/Android/data/<packageName>
+ // Create [2] /mnt/user/0/package/<packageName>/emulated/0/Android/data/<packageName>
+ // Mount [1] at [2]
+ std::string pkgDataSourceDir = preparePkgDataSource(packageName, uid, dataRoot);
+ if (pkgDataSourceDir.empty()) {
+ return -errno;
+ }
+ std::string pkgDataTargetDir = preparePkgDataTarget(packageName, uid,
+ pkgSandboxTargetDir);
+ if (pkgDataTargetDir.empty()) {
+ return -errno;
+ }
+ if (TEMP_FAILURE_RETRY(mount(pkgDataSourceDir.c_str(), pkgDataTargetDir.c_str(),
+ nullptr, MS_BIND | MS_REC | MS_SLAVE, nullptr)) == -1) {
+ PLOG(ERROR) << "Failed to mount " << pkgDataSourceDir << " at "
+ << pkgDataTargetDir;
+ return -errno;
+ }
+
+ // Create [1] /mnt/user/0/package/<packageName>/self/primary
+ // Already created [2] /mnt/user/0/package/<packageName>/emulated/0
+ // Mount [2] at [1]
+ std::string pkgPrimaryTargetDir = prepareSubDirs(
+ StringPrintf("%s/%s", mntTargetRoot.c_str(), packageName.c_str()),
+ "self/primary/", 0755, uid, uid);
+ if (pkgPrimaryTargetDir.empty()) {
+ return -errno;
+ }
+ if (TEMP_FAILURE_RETRY(mount(pkgSandboxTargetDir.c_str(), pkgPrimaryTargetDir.c_str(),
+ nullptr, MS_BIND | MS_REC | MS_SLAVE, nullptr)) == -1) {
+ PLOG(ERROR) << "Failed to mount " << pkgSandboxTargetDir << " at "
+ << pkgPrimaryTargetDir;
+ return -errno;
+ }
+ }
return 0;
}
+std::string VolumeManager::prepareSubDirs(const std::string& pathPrefix,
+ const std::string& subDirs, mode_t mode, uid_t uid, gid_t gid) {
+ std::string path(pathPrefix);
+ std::vector<std::string> subDirList = android::base::Split(subDirs, "/");
+ for (size_t i = 0; i < subDirList.size(); ++i) {
+ std::string subDir = subDirList[i];
+ if (subDir.empty()) {
+ continue;
+ }
+ StringAppendF(&path, "/%s", subDir.c_str());
+ if (fs_prepare_dir(path.c_str(), mode, uid, gid) != 0) {
+ PLOG(ERROR) << "fs_prepare_dir failed on " << path;
+ return kEmptyString;
+ }
+ }
+ return path;
+}
+
+std::string VolumeManager::prepareSandboxSource(uid_t uid, const std::string& sandboxId,
+ const std::string& sandboxRootDir) {
+ std::string sandboxSourceDir = StringPrintf("%s/%s",
+ sandboxRootDir.c_str(), sandboxId.c_str());
+ if (fs_prepare_dir(sandboxSourceDir.c_str(), 0755, uid, uid) != 0) {
+ PLOG(ERROR) << "fs_prepare_dir failed on " << sandboxSourceDir;
+ return kEmptyString;
+ }
+ return sandboxSourceDir;
+}
+
+std::string VolumeManager::prepareSandboxTarget(const std::string& packageName, uid_t uid,
+ const std::string& volumeLabel, const std::string& mntTargetRootDir,
+ bool isUserDependent) {
+ std::string segment;
+ if (isUserDependent) {
+ segment = StringPrintf("%s/%s/%d/",
+ packageName.c_str(), volumeLabel.c_str(), multiuser_get_user_id(uid));
+ } else {
+ segment = StringPrintf("%s/%s/",
+ packageName.c_str(), volumeLabel.c_str());
+ }
+ return prepareSubDirs(mntTargetRootDir, segment.c_str(), 0755, uid, uid);
+}
+
+std::string VolumeManager::preparePkgDataSource(const std::string& packageName, uid_t uid,
+ const std::string& dataRootDir) {
+ std::string dataSourceDir = StringPrintf("%s/%s", dataRootDir.c_str(), packageName.c_str());
+ if (fs_prepare_dir(dataSourceDir.c_str(), 0755, uid, uid) != 0) {
+ PLOG(ERROR) << "fs_prepare_dir failed on " << dataSourceDir;
+ return kEmptyString;
+ }
+ return dataSourceDir;
+}
+
+std::string VolumeManager::preparePkgDataTarget(const std::string& packageName, uid_t uid,
+ const std::string& pkgSandboxDir) {
+ std::string segment = StringPrintf("Android/data/%s/", packageName.c_str());
+ return prepareSubDirs(pkgSandboxDir, segment.c_str(), 0755, uid, uid);
+}
+
int VolumeManager::onUserAdded(userid_t userId, int userSerialNumber) {
mAddedUsers[userId] = userSerialNumber;
return 0;
@@ -382,7 +549,7 @@
mStartedUsers.insert(userId);
mUserPackages[userId] = packageNames;
if (mPrimary) {
- linkPrimary(userId);
+ linkPrimary(userId, packageNames);
}
return 0;
}
@@ -425,7 +592,7 @@
int VolumeManager::setPrimary(const std::shared_ptr<android::vold::VolumeBase>& vol) {
mPrimary = vol;
for (userid_t userId : mStartedUsers) {
- linkPrimary(userId);
+ linkPrimary(userId, mUserPackages[userId]);
}
return 0;
}
@@ -458,6 +625,11 @@
}
int VolumeManager::remountUid(uid_t uid, const std::string& mode) {
+ // If the isolated storage is enabled, return -1 since in the isolated storage world, there
+ // are no longer any runtime storage permissions, so this shouldn't be called anymore.
+ if (GetBoolProperty(kIsolatedStorage, false)) {
+ return -1;
+ }
LOG(DEBUG) << "Remounting " << uid << " as mode " << mode;
DIR* dir;