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/*
* Copyright (C) 2012 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.
*/
#define LOG_TAG "ServiceUtilities"
#include <audio_utils/clock.h>
#include <binder/AppOpsManager.h>
#include <binder/IPCThreadState.h>
#include <binder/IServiceManager.h>
#include <binder/PermissionCache.h>
#include "mediautils/ServiceUtilities.h"
#include <system/audio-hal-enums.h>
#include <media/AidlConversion.h>
#include <media/AidlConversionUtil.h>
#include <android/content/AttributionSourceState.h>
#include <iterator>
#include <algorithm>
#include <pwd.h>
/* When performing permission checks we do not use permission cache for
* runtime permissions (protection level dangerous) as they may change at
* runtime. All other permissions (protection level normal and dangerous)
* can be cached as they never change. Of course all permission checked
* here are platform defined.
*/
namespace android {
using content::AttributionSourceState;
static const String16 sAndroidPermissionRecordAudio("android.permission.RECORD_AUDIO");
static const String16 sModifyPhoneState("android.permission.MODIFY_PHONE_STATE");
static const String16 sModifyAudioRouting("android.permission.MODIFY_AUDIO_ROUTING");
static String16 resolveCallingPackage(PermissionController& permissionController,
const std::optional<String16> opPackageName, uid_t uid) {
if (opPackageName.has_value() && opPackageName.value().size() > 0) {
return opPackageName.value();
}
// In some cases the calling code has no access to the package it runs under.
// For example, code using the wilhelm framework's OpenSL-ES APIs. In this
// case we will get the packages for the calling UID and pick the first one
// for attributing the app op. This will work correctly for runtime permissions
// as for legacy apps we will toggle the app op for all packages in the UID.
// The caveat is that the operation may be attributed to the wrong package and
// stats based on app ops may be slightly off.
Vector<String16> packages;
permissionController.getPackagesForUid(uid, packages);
if (packages.isEmpty()) {
ALOGE("No packages for uid %d", uid);
return String16();
}
return packages[0];
}
int32_t getOpForSource(audio_source_t source) {
switch (source) {
case AUDIO_SOURCE_HOTWORD:
return AppOpsManager::OP_RECORD_AUDIO_HOTWORD;
case AUDIO_SOURCE_REMOTE_SUBMIX:
return AppOpsManager::OP_RECORD_AUDIO_OUTPUT;
case AUDIO_SOURCE_VOICE_DOWNLINK:
return AppOpsManager::OP_RECORD_INCOMING_PHONE_AUDIO;
case AUDIO_SOURCE_DEFAULT:
default:
return AppOpsManager::OP_RECORD_AUDIO;
}
}
std::optional<AttributionSourceState> resolveAttributionSource(
const AttributionSourceState& callerAttributionSource) {
AttributionSourceState nextAttributionSource = callerAttributionSource;
if (!nextAttributionSource.packageName.has_value()) {
nextAttributionSource = AttributionSourceState(nextAttributionSource);
PermissionController permissionController;
const uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(nextAttributionSource.uid));
nextAttributionSource.packageName = VALUE_OR_FATAL(legacy2aidl_String16_string(
resolveCallingPackage(permissionController, VALUE_OR_FATAL(
aidl2legacy_string_view_String16(nextAttributionSource.packageName.value_or(""))),
uid)));
if (!nextAttributionSource.packageName.has_value()) {
return std::nullopt;
}
}
AttributionSourceState myAttributionSource;
myAttributionSource.uid = VALUE_OR_FATAL(android::legacy2aidl_uid_t_int32_t(getuid()));
myAttributionSource.pid = VALUE_OR_FATAL(android::legacy2aidl_pid_t_int32_t(getpid()));
// Create a static token for audioserver requests, which identifies the
// audioserver to the app ops system
static sp<BBinder> appOpsToken = sp<BBinder>::make();
myAttributionSource.token = appOpsToken;
myAttributionSource.next.push_back(nextAttributionSource);
return std::optional<AttributionSourceState>{myAttributionSource};
}
static bool checkRecordingInternal(const AttributionSourceState& attributionSource,
const String16& msg, bool start, audio_source_t source) {
// Okay to not track in app ops as audio server or media server is us and if
// device is rooted security model is considered compromised.
// system_server loses its RECORD_AUDIO permission when a secondary
// user is active, but it is a core system service so let it through.
// TODO(b/141210120): UserManager.DISALLOW_RECORD_AUDIO should not affect system user 0
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
if (isAudioServerOrMediaServerOrSystemServerOrRootUid(uid)) return true;
// We specify a pid and uid here as mediaserver (aka MediaRecorder or StageFrightRecorder)
// may open a record track on behalf of a client. Note that pid may be a tid.
// IMPORTANT: DON'T USE PermissionCache - RUNTIME PERMISSIONS CHANGE.
const std::optional<AttributionSourceState> resolvedAttributionSource =
resolveAttributionSource(attributionSource);
if (!resolvedAttributionSource.has_value()) {
return false;
}
const int32_t attributedOpCode = getOpForSource(source);
permission::PermissionChecker permissionChecker;
bool permitted = false;
if (start) {
permitted = (permissionChecker.checkPermissionForStartDataDeliveryFromDatasource(
sAndroidPermissionRecordAudio, resolvedAttributionSource.value(), msg,
attributedOpCode) != permission::PermissionChecker::PERMISSION_HARD_DENIED);
} else {
permitted = (permissionChecker.checkPermissionForPreflightFromDatasource(
sAndroidPermissionRecordAudio, resolvedAttributionSource.value(), msg,
attributedOpCode) != permission::PermissionChecker::PERMISSION_HARD_DENIED);
}
return permitted;
}
bool recordingAllowed(const AttributionSourceState& attributionSource, audio_source_t source) {
return checkRecordingInternal(attributionSource, String16(), /*start*/ false, source);
}
bool startRecording(const AttributionSourceState& attributionSource, const String16& msg,
audio_source_t source) {
return checkRecordingInternal(attributionSource, msg, /*start*/ true, source);
}
void finishRecording(const AttributionSourceState& attributionSource, audio_source_t source) {
// Okay to not track in app ops as audio server is us and if
// device is rooted security model is considered compromised.
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
if (isAudioServerOrMediaServerOrSystemServerOrRootUid(uid)) return;
// We specify a pid and uid here as mediaserver (aka MediaRecorder or StageFrightRecorder)
// may open a record track on behalf of a client. Note that pid may be a tid.
// IMPORTANT: DON'T USE PermissionCache - RUNTIME PERMISSIONS CHANGE.
const std::optional<AttributionSourceState> resolvedAttributionSource =
resolveAttributionSource(attributionSource);
if (!resolvedAttributionSource.has_value()) {
return;
}
const int32_t attributedOpCode = getOpForSource(source);
permission::PermissionChecker permissionChecker;
permissionChecker.finishDataDeliveryFromDatasource(attributedOpCode,
resolvedAttributionSource.value());
}
bool captureAudioOutputAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
pid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
if (isAudioServerOrRootUid(uid)) return true;
static const String16 sCaptureAudioOutput("android.permission.CAPTURE_AUDIO_OUTPUT");
bool ok = PermissionCache::checkPermission(sCaptureAudioOutput, pid, uid);
if (!ok) ALOGV("Request requires android.permission.CAPTURE_AUDIO_OUTPUT");
return ok;
}
bool captureMediaOutputAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
pid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
if (isAudioServerOrRootUid(uid)) return true;
static const String16 sCaptureMediaOutput("android.permission.CAPTURE_MEDIA_OUTPUT");
bool ok = PermissionCache::checkPermission(sCaptureMediaOutput, pid, uid);
if (!ok) ALOGE("Request requires android.permission.CAPTURE_MEDIA_OUTPUT");
return ok;
}
bool captureTunerAudioInputAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
pid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
if (isAudioServerOrRootUid(uid)) return true;
static const String16 sCaptureTunerAudioInput("android.permission.CAPTURE_TUNER_AUDIO_INPUT");
bool ok = PermissionCache::checkPermission(sCaptureTunerAudioInput, pid, uid);
if (!ok) ALOGV("Request requires android.permission.CAPTURE_TUNER_AUDIO_INPUT");
return ok;
}
bool captureVoiceCommunicationOutputAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
uid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
if (isAudioServerOrRootUid(uid)) return true;
static const String16 sCaptureVoiceCommOutput(
"android.permission.CAPTURE_VOICE_COMMUNICATION_OUTPUT");
bool ok = PermissionCache::checkPermission(sCaptureVoiceCommOutput, pid, uid);
if (!ok) ALOGE("Request requires android.permission.CAPTURE_VOICE_COMMUNICATION_OUTPUT");
return ok;
}
bool captureHotwordAllowed(const AttributionSourceState& attributionSource) {
// CAPTURE_AUDIO_HOTWORD permission implies RECORD_AUDIO permission
bool ok = recordingAllowed(attributionSource);
if (ok) {
static const String16 sCaptureHotwordAllowed("android.permission.CAPTURE_AUDIO_HOTWORD");
// Use PermissionChecker, which includes some logic for allowing the isolated
// HotwordDetectionService to hold certain permissions.
permission::PermissionChecker permissionChecker;
ok = (permissionChecker.checkPermissionForPreflight(
sCaptureHotwordAllowed, attributionSource, String16(),
AppOpsManager::OP_NONE) != permission::PermissionChecker::PERMISSION_HARD_DENIED);
}
if (!ok) ALOGV("android.permission.CAPTURE_AUDIO_HOTWORD");
return ok;
}
bool settingsAllowed() {
// given this is a permission check, could this be isAudioServerOrRootUid()?
if (isAudioServerUid(IPCThreadState::self()->getCallingUid())) return true;
static const String16 sAudioSettings("android.permission.MODIFY_AUDIO_SETTINGS");
// IMPORTANT: Use PermissionCache - not a runtime permission and may not change.
bool ok = PermissionCache::checkCallingPermission(sAudioSettings);
if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");
return ok;
}
bool modifyAudioRoutingAllowed() {
return modifyAudioRoutingAllowed(getCallingAttributionSource());
}
bool modifyAudioRoutingAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
pid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
if (isAudioServerUid(IPCThreadState::self()->getCallingUid())) return true;
// IMPORTANT: Use PermissionCache - not a runtime permission and may not change.
bool ok = PermissionCache::checkPermission(sModifyAudioRouting, pid, uid);
if (!ok) ALOGE("%s(): android.permission.MODIFY_AUDIO_ROUTING denied for uid %d",
__func__, uid);
return ok;
}
bool modifyDefaultAudioEffectsAllowed() {
return modifyDefaultAudioEffectsAllowed(getCallingAttributionSource());
}
bool modifyDefaultAudioEffectsAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
pid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
if (isAudioServerUid(IPCThreadState::self()->getCallingUid())) return true;
static const String16 sModifyDefaultAudioEffectsAllowed(
"android.permission.MODIFY_DEFAULT_AUDIO_EFFECTS");
// IMPORTANT: Use PermissionCache - not a runtime permission and may not change.
bool ok = PermissionCache::checkPermission(sModifyDefaultAudioEffectsAllowed, pid, uid);
ALOGE_IF(!ok, "%s(): android.permission.MODIFY_DEFAULT_AUDIO_EFFECTS denied for uid %d",
__func__, uid);
return ok;
}
bool dumpAllowed() {
static const String16 sDump("android.permission.DUMP");
// IMPORTANT: Use PermissionCache - not a runtime permission and may not change.
bool ok = PermissionCache::checkCallingPermission(sDump);
// convention is for caller to dump an error message to fd instead of logging here
//if (!ok) ALOGE("Request requires android.permission.DUMP");
return ok;
}
bool modifyPhoneStateAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
pid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
bool ok = PermissionCache::checkPermission(sModifyPhoneState, pid, uid);
ALOGE_IF(!ok, "Request requires %s", String8(sModifyPhoneState).c_str());
return ok;
}
// privileged behavior needed by Dialer, Settings, SetupWizard and CellBroadcastReceiver
bool bypassInterruptionPolicyAllowed(const AttributionSourceState& attributionSource) {
uid_t uid = VALUE_OR_FATAL(aidl2legacy_int32_t_uid_t(attributionSource.uid));
pid_t pid = VALUE_OR_FATAL(aidl2legacy_int32_t_pid_t(attributionSource.pid));
static const String16 sWriteSecureSettings("android.permission.WRITE_SECURE_SETTINGS");
bool ok = PermissionCache::checkPermission(sModifyPhoneState, pid, uid)
|| PermissionCache::checkPermission(sWriteSecureSettings, pid, uid)
|| PermissionCache::checkPermission(sModifyAudioRouting, pid, uid);
ALOGE_IF(!ok, "Request requires %s or %s",
String8(sModifyPhoneState).c_str(), String8(sWriteSecureSettings).c_str());
return ok;
}
AttributionSourceState getCallingAttributionSource() {
AttributionSourceState attributionSource = AttributionSourceState();
attributionSource.pid = VALUE_OR_FATAL(legacy2aidl_pid_t_int32_t(
IPCThreadState::self()->getCallingPid()));
attributionSource.uid = VALUE_OR_FATAL(legacy2aidl_uid_t_int32_t(
IPCThreadState::self()->getCallingUid()));
attributionSource.token = sp<BBinder>::make();
return attributionSource;
}
void purgePermissionCache() {
PermissionCache::purgeCache();
}
status_t checkIMemory(const sp<IMemory>& iMemory)
{
if (iMemory == 0) {
ALOGE("%s check failed: NULL IMemory pointer", __FUNCTION__);
return BAD_VALUE;
}
sp<IMemoryHeap> heap = iMemory->getMemory();
if (heap == 0) {
ALOGE("%s check failed: NULL heap pointer", __FUNCTION__);
return BAD_VALUE;
}
off_t size = lseek(heap->getHeapID(), 0, SEEK_END);
lseek(heap->getHeapID(), 0, SEEK_SET);
if (iMemory->unsecurePointer() == NULL || size < (off_t)iMemory->size()) {
ALOGE("%s check failed: pointer %p size %zu fd size %u",
__FUNCTION__, iMemory->unsecurePointer(), iMemory->size(), (uint32_t)size);
return BAD_VALUE;
}
return NO_ERROR;
}
sp<content::pm::IPackageManagerNative> MediaPackageManager::retrievePackageManager() {
const sp<IServiceManager> sm = defaultServiceManager();
if (sm == nullptr) {
ALOGW("%s: failed to retrieve defaultServiceManager", __func__);
return nullptr;
}
sp<IBinder> packageManager = sm->checkService(String16(nativePackageManagerName));
if (packageManager == nullptr) {
ALOGW("%s: failed to retrieve native package manager", __func__);
return nullptr;
}
return interface_cast<content::pm::IPackageManagerNative>(packageManager);
}
std::optional<bool> MediaPackageManager::doIsAllowed(uid_t uid) {
if (mPackageManager == nullptr) {
/** Can not fetch package manager at construction it may not yet be registered. */
mPackageManager = retrievePackageManager();
if (mPackageManager == nullptr) {
ALOGW("%s: Playback capture is denied as package manager is not reachable", __func__);
return std::nullopt;
}
}
// Retrieve package names for the UID and transform to a std::vector<std::string>.
Vector<String16> str16PackageNames;
PermissionController{}.getPackagesForUid(uid, str16PackageNames);
std::vector<std::string> packageNames;
for (const auto& str16PackageName : str16PackageNames) {
packageNames.emplace_back(String8(str16PackageName).string());
}
if (packageNames.empty()) {
ALOGW("%s: Playback capture for uid %u is denied as no package name could be retrieved "
"from the package manager.", __func__, uid);
return std::nullopt;
}
std::vector<bool> isAllowed;
auto status = mPackageManager->isAudioPlaybackCaptureAllowed(packageNames, &isAllowed);
if (!status.isOk()) {
ALOGW("%s: Playback capture is denied for uid %u as the manifest property could not be "
"retrieved from the package manager: %s", __func__, uid, status.toString8().c_str());
return std::nullopt;
}
if (packageNames.size() != isAllowed.size()) {
ALOGW("%s: Playback capture is denied for uid %u as the package manager returned incoherent"
" response size: %zu != %zu", __func__, uid, packageNames.size(), isAllowed.size());
return std::nullopt;
}
// Zip together packageNames and isAllowed for debug logs
Packages& packages = mDebugLog[uid];
packages.resize(packageNames.size()); // Reuse all objects
std::transform(begin(packageNames), end(packageNames), begin(isAllowed),
begin(packages), [] (auto& name, bool isAllowed) -> Package {
return {std::move(name), isAllowed};
});
// Only allow playback record if all packages in this UID allow it
bool playbackCaptureAllowed = std::all_of(begin(isAllowed), end(isAllowed),
[](bool b) { return b; });
return playbackCaptureAllowed;
}
void MediaPackageManager::dump(int fd, int spaces) const {
dprintf(fd, "%*sAllow playback capture log:\n", spaces, "");
if (mPackageManager == nullptr) {
dprintf(fd, "%*sNo package manager\n", spaces + 2, "");
}
dprintf(fd, "%*sPackage manager errors: %u\n", spaces + 2, "", mPackageManagerErrors);
for (const auto& uidCache : mDebugLog) {
for (const auto& package : std::get<Packages>(uidCache)) {
dprintf(fd, "%*s- uid=%5u, allowPlaybackCapture=%s, packageName=%s\n", spaces + 2, "",
std::get<const uid_t>(uidCache),
package.playbackCaptureAllowed ? "true " : "false",
package.name.c_str());
}
}
}
// How long we hold info before we re-fetch it (24 hours) if we found it previously.
static constexpr nsecs_t INFO_EXPIRATION_NS = 24 * 60 * 60 * NANOS_PER_SECOND;
// Maximum info records we retain before clearing everything.
static constexpr size_t INFO_CACHE_MAX = 1000;
// The original code is from MediaMetricsService.cpp.
mediautils::UidInfo::Info mediautils::UidInfo::getInfo(uid_t uid)
{
const nsecs_t now = systemTime(SYSTEM_TIME_REALTIME);
struct mediautils::UidInfo::Info info;
{
std::lock_guard _l(mLock);
auto it = mInfoMap.find(uid);
if (it != mInfoMap.end()) {
info = it->second;
ALOGV("%s: uid %d expiration %lld now %lld",
__func__, uid, (long long)info.expirationNs, (long long)now);
if (info.expirationNs <= now) {
// purge the stale entry and fall into re-fetching
ALOGV("%s: entry for uid %d expired, now %lld",
__func__, uid, (long long)now);
mInfoMap.erase(it);
info.uid = (uid_t)-1; // this is always fully overwritten
}
}
}
// if we did not find it in our map, look it up
if (info.uid == (uid_t)(-1)) {
sp<IServiceManager> sm = defaultServiceManager();
sp<content::pm::IPackageManagerNative> package_mgr;
if (sm.get() == nullptr) {
ALOGE("%s: Cannot find service manager", __func__);
} else {
sp<IBinder> binder = sm->getService(String16("package_native"));
if (binder.get() == nullptr) {
ALOGE("%s: Cannot find package_native", __func__);
} else {
package_mgr = interface_cast<content::pm::IPackageManagerNative>(binder);
}
}
// find package name
std::string pkg;
if (package_mgr != nullptr) {
std::vector<std::string> names;
binder::Status status = package_mgr->getNamesForUids({(int)uid}, &names);
if (!status.isOk()) {
ALOGE("%s: getNamesForUids failed: %s",
__func__, status.exceptionMessage().c_str());
} else {
if (!names[0].empty()) {
pkg = names[0].c_str();
}
}
}
if (pkg.empty()) {
struct passwd pw{}, *result;
char buf[8192]; // extra buffer space - should exceed what is
// required in struct passwd_pw (tested),
// and even then this is only used in backup
// when the package manager is unavailable.
if (getpwuid_r(uid, &pw, buf, sizeof(buf), &result) == 0
&& result != nullptr
&& result->pw_name != nullptr) {
pkg = result->pw_name;
}
}
// strip any leading "shared:" strings that came back
if (pkg.compare(0, 7, "shared:") == 0) {
pkg.erase(0, 7);
}
// determine how pkg was installed and the versionCode
std::string installer;
int64_t versionCode = 0;
bool notFound = false;
if (pkg.empty()) {
pkg = std::to_string(uid); // not found
notFound = true;
} else if (strchr(pkg.c_str(), '.') == nullptr) {
// not of form 'com.whatever...'; assume internal
// so we don't need to look it up in package manager.
} else if (strncmp(pkg.c_str(), "android.", 8) == 0) {
// android.* packages are assumed fine
} else if (package_mgr.get() != nullptr) {
String16 pkgName16(pkg.c_str());
binder::Status status = package_mgr->getInstallerForPackage(pkgName16, &installer);
if (!status.isOk()) {
ALOGE("%s: getInstallerForPackage failed: %s",
__func__, status.exceptionMessage().c_str());
}
// skip if we didn't get an installer
if (status.isOk()) {
status = package_mgr->getVersionCodeForPackage(pkgName16, &versionCode);
if (!status.isOk()) {
ALOGE("%s: getVersionCodeForPackage failed: %s",
__func__, status.exceptionMessage().c_str());
}
}
ALOGV("%s: package '%s' installed by '%s' versioncode %lld",
__func__, pkg.c_str(), installer.c_str(), (long long)versionCode);
}
// add it to the map, to save a subsequent lookup
std::lock_guard _l(mLock);
// first clear if we have too many cached elements. This would be rare.
if (mInfoMap.size() >= INFO_CACHE_MAX) mInfoMap.clear();
// always overwrite
info.uid = uid;
info.package = std::move(pkg);
info.installer = std::move(installer);
info.versionCode = versionCode;
info.expirationNs = now + (notFound ? 0 : INFO_EXPIRATION_NS);
ALOGV("%s: adding uid %d package '%s' expirationNs: %lld",
__func__, uid, info.package.c_str(), (long long)info.expirationNs);
mInfoMap[uid] = info;
}
return info;
}
} // namespace android