| /* |
| * Copyright (C) 2005 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 "ServiceManager" |
| |
| #include <binder/IServiceManager.h> |
| |
| #include <android/os/BnServiceCallback.h> |
| #include <android/os/IServiceManager.h> |
| #include <binder/IPCThreadState.h> |
| #include <binder/Parcel.h> |
| #include <utils/Log.h> |
| #include <utils/String8.h> |
| #include <utils/SystemClock.h> |
| |
| #ifndef __ANDROID_VNDK__ |
| #include <binder/IPermissionController.h> |
| #endif |
| |
| #ifdef __ANDROID__ |
| #include <cutils/properties.h> |
| #endif |
| |
| #include "Static.h" |
| |
| #include <unistd.h> |
| |
| namespace android { |
| |
| using AidlServiceManager = android::os::IServiceManager; |
| using android::binder::Status; |
| |
| // libbinder's IServiceManager.h can't rely on the values generated by AIDL |
| // because many places use its headers via include_dirs (meaning, without |
| // declaring the dependency in the build system). So, for now, we can just check |
| // the values here. |
| static_assert(AidlServiceManager::DUMP_FLAG_PRIORITY_CRITICAL == IServiceManager::DUMP_FLAG_PRIORITY_CRITICAL); |
| static_assert(AidlServiceManager::DUMP_FLAG_PRIORITY_HIGH == IServiceManager::DUMP_FLAG_PRIORITY_HIGH); |
| static_assert(AidlServiceManager::DUMP_FLAG_PRIORITY_NORMAL == IServiceManager::DUMP_FLAG_PRIORITY_NORMAL); |
| static_assert(AidlServiceManager::DUMP_FLAG_PRIORITY_DEFAULT == IServiceManager::DUMP_FLAG_PRIORITY_DEFAULT); |
| static_assert(AidlServiceManager::DUMP_FLAG_PRIORITY_ALL == IServiceManager::DUMP_FLAG_PRIORITY_ALL); |
| static_assert(AidlServiceManager::DUMP_FLAG_PROTO == IServiceManager::DUMP_FLAG_PROTO); |
| |
| const String16& IServiceManager::getInterfaceDescriptor() const { |
| return AidlServiceManager::descriptor; |
| } |
| IServiceManager::IServiceManager() {} |
| IServiceManager::~IServiceManager() {} |
| |
| // From the old libbinder IServiceManager interface to IServiceManager. |
| class ServiceManagerShim : public IServiceManager |
| { |
| public: |
| explicit ServiceManagerShim (const sp<AidlServiceManager>& impl); |
| |
| sp<IBinder> getService(const String16& name) const override; |
| sp<IBinder> checkService(const String16& name) const override; |
| status_t addService(const String16& name, const sp<IBinder>& service, |
| bool allowIsolated, int dumpsysPriority) override; |
| Vector<String16> listServices(int dumpsysPriority) override; |
| sp<IBinder> waitForService(const String16& name16) override; |
| bool isDeclared(const String16& name) override; |
| |
| // for legacy ABI |
| const String16& getInterfaceDescriptor() const override { |
| return mTheRealServiceManager->getInterfaceDescriptor(); |
| } |
| IBinder* onAsBinder() override { |
| return IInterface::asBinder(mTheRealServiceManager).get(); |
| } |
| private: |
| sp<AidlServiceManager> mTheRealServiceManager; |
| }; |
| |
| [[clang::no_destroy]] static std::once_flag gSmOnce; |
| [[clang::no_destroy]] static sp<IServiceManager> gDefaultServiceManager; |
| |
| sp<IServiceManager> defaultServiceManager() |
| { |
| std::call_once(gSmOnce, []() { |
| sp<AidlServiceManager> sm = nullptr; |
| while (sm == nullptr) { |
| sm = interface_cast<AidlServiceManager>(ProcessState::self()->getContextObject(nullptr)); |
| if (sm == nullptr) { |
| ALOGE("Waiting 1s on context object on %s.", ProcessState::self()->getDriverName().c_str()); |
| sleep(1); |
| } |
| } |
| |
| gDefaultServiceManager = new ServiceManagerShim(sm); |
| }); |
| |
| return gDefaultServiceManager; |
| } |
| |
| void setDefaultServiceManager(const sp<IServiceManager>& sm) { |
| bool called = false; |
| std::call_once(gSmOnce, [&]() { |
| gDefaultServiceManager = sm; |
| called = true; |
| }); |
| |
| if (!called) { |
| LOG_ALWAYS_FATAL("setDefaultServiceManager() called after defaultServiceManager()."); |
| } |
| } |
| |
| #if !defined(__ANDROID_VNDK__) && defined(__ANDROID__) |
| // IPermissionController is not accessible to vendors |
| |
| bool checkCallingPermission(const String16& permission) |
| { |
| return checkCallingPermission(permission, nullptr, nullptr); |
| } |
| |
| static String16 _permission("permission"); |
| |
| |
| bool checkCallingPermission(const String16& permission, int32_t* outPid, int32_t* outUid) |
| { |
| IPCThreadState* ipcState = IPCThreadState::self(); |
| pid_t pid = ipcState->getCallingPid(); |
| uid_t uid = ipcState->getCallingUid(); |
| if (outPid) *outPid = pid; |
| if (outUid) *outUid = uid; |
| return checkPermission(permission, pid, uid); |
| } |
| |
| bool checkPermission(const String16& permission, pid_t pid, uid_t uid) |
| { |
| static Mutex gPermissionControllerLock; |
| static sp<IPermissionController> gPermissionController; |
| |
| sp<IPermissionController> pc; |
| gPermissionControllerLock.lock(); |
| pc = gPermissionController; |
| gPermissionControllerLock.unlock(); |
| |
| int64_t startTime = 0; |
| |
| while (true) { |
| if (pc != nullptr) { |
| bool res = pc->checkPermission(permission, pid, uid); |
| if (res) { |
| if (startTime != 0) { |
| ALOGI("Check passed after %d seconds for %s from uid=%d pid=%d", |
| (int)((uptimeMillis()-startTime)/1000), |
| String8(permission).string(), uid, pid); |
| } |
| return res; |
| } |
| |
| // Is this a permission failure, or did the controller go away? |
| if (IInterface::asBinder(pc)->isBinderAlive()) { |
| ALOGW("Permission failure: %s from uid=%d pid=%d", |
| String8(permission).string(), uid, pid); |
| return false; |
| } |
| |
| // Object is dead! |
| gPermissionControllerLock.lock(); |
| if (gPermissionController == pc) { |
| gPermissionController = nullptr; |
| } |
| gPermissionControllerLock.unlock(); |
| } |
| |
| // Need to retrieve the permission controller. |
| sp<IBinder> binder = defaultServiceManager()->checkService(_permission); |
| if (binder == nullptr) { |
| // Wait for the permission controller to come back... |
| if (startTime == 0) { |
| startTime = uptimeMillis(); |
| ALOGI("Waiting to check permission %s from uid=%d pid=%d", |
| String8(permission).string(), uid, pid); |
| } |
| sleep(1); |
| } else { |
| pc = interface_cast<IPermissionController>(binder); |
| // Install the new permission controller, and try again. |
| gPermissionControllerLock.lock(); |
| gPermissionController = pc; |
| gPermissionControllerLock.unlock(); |
| } |
| } |
| } |
| |
| #endif //__ANDROID_VNDK__ |
| |
| // ---------------------------------------------------------------------- |
| |
| ServiceManagerShim::ServiceManagerShim(const sp<AidlServiceManager>& impl) |
| : mTheRealServiceManager(impl) |
| {} |
| |
| sp<IBinder> ServiceManagerShim::getService(const String16& name) const |
| { |
| static bool gSystemBootCompleted = false; |
| |
| sp<IBinder> svc = checkService(name); |
| if (svc != nullptr) return svc; |
| |
| const bool isVendorService = |
| strcmp(ProcessState::self()->getDriverName().c_str(), "/dev/vndbinder") == 0; |
| const long timeout = uptimeMillis() + 5000; |
| // Vendor code can't access system properties |
| if (!gSystemBootCompleted && !isVendorService) { |
| #ifdef __ANDROID__ |
| char bootCompleted[PROPERTY_VALUE_MAX]; |
| property_get("sys.boot_completed", bootCompleted, "0"); |
| gSystemBootCompleted = strcmp(bootCompleted, "1") == 0 ? true : false; |
| #else |
| gSystemBootCompleted = true; |
| #endif |
| } |
| // retry interval in millisecond; note that vendor services stay at 100ms |
| const long sleepTime = gSystemBootCompleted ? 1000 : 100; |
| |
| int n = 0; |
| while (uptimeMillis() < timeout) { |
| n++; |
| ALOGI("Waiting for service '%s' on '%s'...", String8(name).string(), |
| ProcessState::self()->getDriverName().c_str()); |
| usleep(1000*sleepTime); |
| |
| sp<IBinder> svc = checkService(name); |
| if (svc != nullptr) return svc; |
| } |
| ALOGW("Service %s didn't start. Returning NULL", String8(name).string()); |
| return nullptr; |
| } |
| |
| sp<IBinder> ServiceManagerShim::checkService(const String16& name) const |
| { |
| sp<IBinder> ret; |
| if (!mTheRealServiceManager->checkService(String8(name).c_str(), &ret).isOk()) { |
| return nullptr; |
| } |
| return ret; |
| } |
| |
| status_t ServiceManagerShim::addService(const String16& name, const sp<IBinder>& service, |
| bool allowIsolated, int dumpsysPriority) |
| { |
| Status status = mTheRealServiceManager->addService( |
| String8(name).c_str(), service, allowIsolated, dumpsysPriority); |
| return status.exceptionCode(); |
| } |
| |
| Vector<String16> ServiceManagerShim::listServices(int dumpsysPriority) |
| { |
| std::vector<std::string> ret; |
| if (!mTheRealServiceManager->listServices(dumpsysPriority, &ret).isOk()) { |
| return {}; |
| } |
| |
| Vector<String16> res; |
| res.setCapacity(ret.size()); |
| for (const std::string& name : ret) { |
| res.push(String16(name.c_str())); |
| } |
| return res; |
| } |
| |
| sp<IBinder> ServiceManagerShim::waitForService(const String16& name16) |
| { |
| class Waiter : public android::os::BnServiceCallback { |
| Status onRegistration(const std::string& /*name*/, |
| const sp<IBinder>& binder) override { |
| std::unique_lock<std::mutex> lock(mMutex); |
| mBinder = binder; |
| lock.unlock(); |
| // Flushing here helps ensure the service's ref count remains accurate |
| IPCThreadState::self()->flushCommands(); |
| mCv.notify_one(); |
| return Status::ok(); |
| } |
| public: |
| sp<IBinder> mBinder; |
| std::mutex mMutex; |
| std::condition_variable mCv; |
| }; |
| |
| // Simple RAII object to ensure a function call immediately before going out of scope |
| class Defer { |
| public: |
| Defer(std::function<void()>&& f) : mF(std::move(f)) {} |
| ~Defer() { mF(); } |
| private: |
| std::function<void()> mF; |
| }; |
| |
| const std::string name = String8(name16).c_str(); |
| |
| sp<IBinder> out; |
| if (!mTheRealServiceManager->getService(name, &out).isOk()) { |
| return nullptr; |
| } |
| if (out != nullptr) return out; |
| |
| sp<Waiter> waiter = new Waiter; |
| if (!mTheRealServiceManager->registerForNotifications( |
| name, waiter).isOk()) { |
| return nullptr; |
| } |
| Defer unregister ([&] { |
| mTheRealServiceManager->unregisterForNotifications(name, waiter); |
| }); |
| |
| while(true) { |
| { |
| std::unique_lock<std::mutex> lock(waiter->mMutex); |
| using std::literals::chrono_literals::operator""s; |
| waiter->mCv.wait_for(lock, 1s, [&] { |
| return waiter->mBinder != nullptr; |
| }); |
| if (waiter->mBinder != nullptr) return waiter->mBinder; |
| } |
| |
| // Handle race condition for lazy services. Here is what can happen: |
| // - the service dies (not processed by init yet). |
| // - sm processes death notification. |
| // - sm gets getService and calls init to start service. |
| // - init gets the start signal, but the service already appears |
| // started, so it does nothing. |
| // - init gets death signal, but doesn't know it needs to restart |
| // the service |
| // - we need to request service again to get it to start |
| if (!mTheRealServiceManager->getService(name, &out).isOk()) { |
| return nullptr; |
| } |
| if (out != nullptr) return out; |
| |
| ALOGW("Waited one second for %s", name.c_str()); |
| } |
| } |
| |
| bool ServiceManagerShim::isDeclared(const String16& name) { |
| bool declared; |
| if (!mTheRealServiceManager->isDeclared(String8(name).c_str(), &declared).isOk()) { |
| return false; |
| } |
| return declared; |
| } |
| |
| } // namespace android |