| /* |
| * 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 <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 { |
| |
| 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 String16& opPackageName, uid_t uid) { |
| if (opPackageName.size() > 0) { |
| return opPackageName; |
| } |
| // 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 opPackageName; // empty string |
| } |
| return packages[0]; |
| } |
| |
| static bool checkRecordingInternal(const String16& opPackageName, pid_t pid, |
| uid_t uid, bool start) { |
| // 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 |
| 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. |
| PermissionController permissionController; |
| const bool ok = permissionController.checkPermission(sAndroidPermissionRecordAudio, pid, uid); |
| if (!ok) { |
| ALOGE("Request requires %s", String8(sAndroidPermissionRecordAudio).c_str()); |
| return false; |
| } |
| |
| String16 resolvedOpPackageName = resolveCallingPackage( |
| permissionController, opPackageName, uid); |
| if (resolvedOpPackageName.size() == 0) { |
| return false; |
| } |
| |
| AppOpsManager appOps; |
| const int32_t op = appOps.permissionToOpCode(sAndroidPermissionRecordAudio); |
| if (start) { |
| if (appOps.startOpNoThrow(op, uid, resolvedOpPackageName, /*startIfModeDefault*/ false) |
| != AppOpsManager::MODE_ALLOWED) { |
| ALOGE("Request denied by app op: %d", op); |
| return false; |
| } |
| } else { |
| if (appOps.checkOp(op, uid, resolvedOpPackageName) != AppOpsManager::MODE_ALLOWED) { |
| ALOGE("Request denied by app op: %d", op); |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| bool recordingAllowed(const String16& opPackageName, pid_t pid, uid_t uid) { |
| return checkRecordingInternal(opPackageName, pid, uid, /*start*/ false); |
| } |
| |
| bool startRecording(const String16& opPackageName, pid_t pid, uid_t uid) { |
| return checkRecordingInternal(opPackageName, pid, uid, /*start*/ true); |
| } |
| |
| void finishRecording(const String16& opPackageName, uid_t uid) { |
| // Okay to not track in app ops as audio server is us and if |
| // device is rooted security model is considered compromised. |
| if (isAudioServerOrRootUid(uid)) return; |
| |
| PermissionController permissionController; |
| String16 resolvedOpPackageName = resolveCallingPackage( |
| permissionController, opPackageName, uid); |
| if (resolvedOpPackageName.size() == 0) { |
| return; |
| } |
| |
| AppOpsManager appOps; |
| const int32_t op = appOps.permissionToOpCode(sAndroidPermissionRecordAudio); |
| appOps.finishOp(op, uid, resolvedOpPackageName); |
| } |
| |
| bool captureAudioOutputAllowed(pid_t pid, uid_t uid) { |
| 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(pid_t pid, uid_t uid) { |
| 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 captureVoiceCommunicationOutputAllowed(pid_t pid, uid_t uid) { |
| 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 String16& opPackageName, pid_t pid, uid_t uid) { |
| // CAPTURE_AUDIO_HOTWORD permission implies RECORD_AUDIO permission |
| bool ok = recordingAllowed(opPackageName, pid, uid); |
| |
| if (ok) { |
| static const String16 sCaptureHotwordAllowed("android.permission.CAPTURE_AUDIO_HOTWORD"); |
| // IMPORTANT: Use PermissionCache - not a runtime permission and may not change. |
| ok = PermissionCache::checkPermission(sCaptureHotwordAllowed, pid, uid); |
| } |
| 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( |
| IPCThreadState::self()->getCallingPid(), IPCThreadState::self()->getCallingUid()); |
| } |
| |
| bool modifyAudioRoutingAllowed(pid_t pid, uid_t uid) { |
| 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( |
| IPCThreadState::self()->getCallingPid(), IPCThreadState::self()->getCallingUid()); |
| } |
| |
| bool modifyDefaultAudioEffectsAllowed(pid_t pid, uid_t uid) { |
| 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(pid_t pid, uid_t uid) { |
| 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(pid_t pid, uid_t uid) { |
| 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; |
| } |
| |
| 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::retreivePackageManager() { |
| 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 = retreivePackageManager(); |
| if (mPackageManager == nullptr) { |
| ALOGW("%s: Playback capture is denied as package manager is not reachable", __func__); |
| return std::nullopt; |
| } |
| } |
| |
| std::vector<std::string> packageNames; |
| auto status = mPackageManager->getNamesForUids({(int32_t)uid}, &packageNames); |
| if (!status.isOk()) { |
| ALOGW("%s: Playback capture is denied for uid %u as the package names could not be " |
| "retrieved from the package manager: %s", __func__, uid, status.toString8().c_str()); |
| return std::nullopt; |
| } |
| if (packageNames.empty()) { |
| ALOGW("%s: Playback capture for uid %u is denied as no package name could be retrieved " |
| "from the package manager: %s", __func__, uid, status.toString8().c_str()); |
| return std::nullopt; |
| } |
| std::vector<bool> isAllowed; |
| 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 |
