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/*
* Copyright (C) 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <android-base/result.h>
#include <functional>
#include <optional>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "apex_constants.h"
#include "apex_file.h"
namespace android {
namespace apex {
using ApexFileRef = std::reference_wrapper<const android::apex::ApexFile>;
// This class serves as a ApexFile repository for all apexes on device. It also
// provides information about the ApexFiles it hosts, such as which are
// pre-installed and which are data. Such information can be used, for example,
// to verify validity of an apex before trying to mount it.
//
// It's expected to have a single instance of this class in a process that
// mounts apexes (e.g. apexd, otapreopt_chroot).
class ApexFileRepository final {
public:
// c-tors and d-tor are exposed for testing.
explicit ApexFileRepository(
const std::string& decompression_dir = kApexDecompressedDir)
: decompression_dir_(decompression_dir){};
explicit ApexFileRepository(
bool enforce_multi_install_partition,
const std::vector<std::string>& multi_install_select_prop_prefixes)
: multi_install_select_prop_prefixes_(multi_install_select_prop_prefixes),
enforce_multi_install_partition_(enforce_multi_install_partition){};
~ApexFileRepository() {
pre_installed_store_.clear();
data_store_.clear();
};
// Returns a singletone instance of this class.
static ApexFileRepository& GetInstance();
// Populate instance by collecting pre-installed apex files from the given
// |prebuilt_dirs|.
// Note: this call is **not thread safe** and is expected to be performed in a
// single thread during initialization of apexd. After initialization is
// finished, all queries to the instance are thread safe.
android::base::Result<void> AddPreInstalledApex(
const std::vector<std::string>& prebuilt_dirs);
// Populate instance by collecting host-provided apex files via
// |metadata_partition|. Host can provide its apexes to a VM instance via the
// virtual disk image which has partitions: (see
// /packages/modules/Virtualization/microdroid for the details)
// - metadata partition(/dev/block/vd*1) should be accessed by
// setting the system property apexd.payload_metadata.prop. On microdroid,
// this is /dev/block/by-name/payload-metadata.
// - each subsequence partition(/dev/block/vd*{2,3,..}) represents an APEX
// archive.
// It will fail if there is more than one apex with the same name in
// pre-installed and block apexes. Note: this call is **not thread safe** and
// is expected to be performed in a single thread during initialization of
// apexd. After initialization is finished, all queries to the instance are
// thread safe.
// This will return the number of block apexes that were added.
android::base::Result<int> AddBlockApex(
const std::string& metadata_partition);
// Populate instance by collecting data apex files from the given |data_dir|.
// Note: this call is **not thread safe** and is expected to be performed in a
// single thread during initialization of apexd. After initialization is
// finished, all queries to the instance are thread safe.
android::base::Result<void> AddDataApex(const std::string& data_dir);
// Returns trusted public key for an apex with the given |name|.
android::base::Result<const std::string> GetPublicKey(
const std::string& name) const;
// Returns path to the pre-installed version of an apex with the given |name|.
android::base::Result<const std::string> GetPreinstalledPath(
const std::string& name) const;
// Returns path to the data version of an apex with the given |name|.
android::base::Result<const std::string> GetDataPath(
const std::string& name) const;
// Returns root digest of an apex with the given |path| for block apexes.
std::optional<std::string> GetBlockApexRootDigest(
const std::string& path) const;
// Returns timestamp to be used for the block apex of the given |path|.
std::optional<int64_t> GetBlockApexLastUpdateSeconds(
const std::string& path) const;
// Checks whether there is a pre-installed version of an apex with the given
// |name|.
bool HasPreInstalledVersion(const std::string& name) const;
// Checks whether there is a data version of an apex with the given |name|.
bool HasDataVersion(const std::string& name) const;
// Checks if given |apex| is pre-installed.
bool IsPreInstalledApex(const ApexFile& apex) const;
// Checks if given |apex| is decompressed from a pre-installed APEX
bool IsDecompressedApex(const ApexFile& apex) const;
// Checks if given |apex| is loaded from block device.
bool IsBlockApex(const ApexFile& apex) const;
// Returns reference to all pre-installed APEX on device
std::vector<ApexFileRef> GetPreInstalledApexFiles() const;
// Returns reference to all data APEX on device
std::vector<ApexFileRef> GetDataApexFiles() const;
// Group all ApexFiles on device by their package name
std::unordered_map<std::string, std::vector<ApexFileRef>> AllApexFilesByName()
const;
// Returns a pre-installed version of apex with the given name. Caller is
// expected to check if there is a pre-installed apex with the given name
// using |HasPreinstalledVersion| function.
ApexFileRef GetPreInstalledApex(const std::string& name) const;
// Returns a data version of apex with the given name. Caller is
// expected to check if there is a data apex with the given name
// using |HasDataVersion| function.
ApexFileRef GetDataApex(const std::string& name) const;
// Clears ApexFileRepostiry.
// Only use in tests.
void Reset(const std::string& decompression_dir = kApexDecompressedDir) {
pre_installed_store_.clear();
data_store_.clear();
block_apex_overrides_.clear();
decompression_dir_ = decompression_dir;
block_disk_path_.reset();
}
private:
// Non-copyable && non-moveable.
ApexFileRepository(const ApexFileRepository&) = delete;
ApexFileRepository& operator=(const ApexFileRepository&) = delete;
ApexFileRepository& operator=(ApexFileRepository&&) = delete;
ApexFileRepository(ApexFileRepository&&) = delete;
// Scans apexes in the given directory and adds collected data into
// |pre_installed_store_|.
android::base::Result<void> ScanBuiltInDir(const std::string& dir);
std::unordered_map<std::string, ApexFile> pre_installed_store_, data_store_;
// Multi-installed APEX name -> all encountered public keys for this APEX.
std::unordered_map<std::string, std::unordered_set<std::string>>
multi_install_public_keys_;
// Prefixes used when looking for multi-installed APEX sysprops.
// Order matters: the first non-empty prop value is returned.
std::vector<std::string> multi_install_select_prop_prefixes_ = {
// Check persist props first, to allow users to override bootconfig.
kMultiApexSelectPersistPrefix,
kMultiApexSelectBootconfigPrefix,
};
// Allows multi-install APEXes outside of expected partitions.
// Only set false in tests.
bool enforce_multi_install_partition_ = true;
// Decompression directory which will be used to determine if apex is
// decompressed or not
std::string decompression_dir_;
// Disk path where block apexes are read from. AddBlockApex() sets this.
std::optional<std::string> block_disk_path_;
// Information from the metadata for block apexes, overriding the file data.
struct BlockApexOverride {
// Root digest for the APEX. When specified in block apex config, it
// should be used/checked when activating the apex to avoid
// TOCTOU(time-of-check to time-of-use).
std::optional<std::string> block_apex_root_digest;
// The last update time of the APEX.
std::optional<int64_t> last_update_seconds;
};
// Use "path" as key instead of APEX name because there can be multiple
// versions of sharedlibs APEXes.
std::unordered_map<std::string, BlockApexOverride> block_apex_overrides_;
};
} // namespace apex
} // namespace android
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