/* * 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 #include #include #include #include #include "mediautils/ServiceUtilities.h" #include #include #include #include #include #include #include /* 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 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 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 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 appOpsToken = sp::make(); myAttributionSource.token = appOpsToken; myAttributionSource.next.push_back(nextAttributionSource); return std::optional{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 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 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::make(); return attributionSource; } void purgePermissionCache() { PermissionCache::purgeCache(); } status_t checkIMemory(const sp& iMemory) { if (iMemory == 0) { ALOGE("%s check failed: NULL IMemory pointer", __FUNCTION__); return BAD_VALUE; } sp 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 MediaPackageManager::retrievePackageManager() { const sp sm = defaultServiceManager(); if (sm == nullptr) { ALOGW("%s: failed to retrieve defaultServiceManager", __func__); return nullptr; } sp packageManager = sm->checkService(String16(nativePackageManagerName)); if (packageManager == nullptr) { ALOGW("%s: failed to retrieve native package manager", __func__); return nullptr; } return interface_cast(packageManager); } std::optional 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. Vector str16PackageNames; PermissionController{}.getPackagesForUid(uid, str16PackageNames); std::vector 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 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(uidCache)) { dprintf(fd, "%*s- uid=%5u, allowPlaybackCapture=%s, packageName=%s\n", spaces + 2, "", std::get(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 sm = defaultServiceManager(); sp package_mgr; if (sm.get() == nullptr) { ALOGE("%s: Cannot find service manager", __func__); } else { sp binder = sm->getService(String16("package_native")); if (binder.get() == nullptr) { ALOGE("%s: Cannot find package_native", __func__); } else { package_mgr = interface_cast(binder); } } // find package name std::string pkg; if (package_mgr != nullptr) { std::vector 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