/* * Copyright (C) 2016 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 "hwservicemanager" #include "ServiceManager.h" #include "Vintf.h" #include #include #include #include #include #include #include #include using android::hardware::IPCThreadState; using ::android::hardware::interfacesEqual; namespace android { namespace hidl { namespace manager { namespace implementation { AccessControl::CallingContext getBinderCallingContext() { const auto& self = IPCThreadState::self(); pid_t pid = self->getCallingPid(); const char* sid = self->getCallingSid(); if (sid == nullptr) { if (pid != getpid()) { android_errorWriteLog(0x534e4554, "121035042"); } return AccessControl::getCallingContext(pid); } else { return { true, sid, pid }; } } static constexpr uint64_t kServiceDiedCookie = 0; static constexpr uint64_t kPackageListenerDiedCookie = 1; static constexpr uint64_t kServiceListenerDiedCookie = 2; static constexpr uint64_t kClientCallbackDiedCookie = 3; size_t ServiceManager::countExistingService() const { size_t total = 0; forEachExistingService([&] (const HidlService *) { ++total; return true; // continue }); return total; } void ServiceManager::forEachExistingService(std::function f) const { forEachServiceEntry([&] (const HidlService *service) { if (service->getService() == nullptr) { return true; // continue } return f(service); }); } void ServiceManager::forEachExistingService(std::function f) { forEachServiceEntry([&] (HidlService *service) { if (service->getService() == nullptr) { return true; // continue } return f(service); }); } void ServiceManager::forEachServiceEntry(std::function f) const { for (const auto& interfaceMapping : mServiceMap) { const auto& instanceMap = interfaceMapping.second.getInstanceMap(); for (const auto& instanceMapping : instanceMap) { if (!f(instanceMapping.second.get())) { return; } } } } void ServiceManager::forEachServiceEntry(std::function f) { for (auto& interfaceMapping : mServiceMap) { auto& instanceMap = interfaceMapping.second.getInstanceMap(); for (auto& instanceMapping : instanceMap) { if (!f(instanceMapping.second.get())) { return; } } } } HidlService* ServiceManager::lookup(const std::string& fqName, const std::string& name) { auto ifaceIt = mServiceMap.find(fqName); if (ifaceIt == mServiceMap.end()) { return nullptr; } PackageInterfaceMap &ifaceMap = ifaceIt->second; HidlService *hidlService = ifaceMap.lookup(name); return hidlService; } void ServiceManager::serviceDied(uint64_t cookie, const wp& who) { bool serviceRemoved = false; switch (cookie) { case kServiceDiedCookie: serviceRemoved = removeService(who, nullptr /* restrictToInstanceName */); break; case kPackageListenerDiedCookie: serviceRemoved = removePackageListener(who); break; case kServiceListenerDiedCookie: serviceRemoved = removeServiceListener(who); break; case kClientCallbackDiedCookie: { sp base = who.promote(); IClientCallback* callback = static_cast(base.get()); serviceRemoved = unregisterClientCallback(nullptr /*service*/, sp(callback)); } break; } if (!serviceRemoved) { LOG(ERROR) << "Received death notification but interface instance not removed. Cookie: " << cookie << " Service pointer: " << who.promote().get(); } } ServiceManager::InstanceMap &ServiceManager::PackageInterfaceMap::getInstanceMap() { return mInstanceMap; } const ServiceManager::InstanceMap &ServiceManager::PackageInterfaceMap::getInstanceMap() const { return mInstanceMap; } const HidlService *ServiceManager::PackageInterfaceMap::lookup( const std::string &name) const { auto it = mInstanceMap.find(name); if (it == mInstanceMap.end()) { return nullptr; } return it->second.get(); } HidlService *ServiceManager::PackageInterfaceMap::lookup( const std::string &name) { return const_cast( const_cast(this)->lookup(name)); } void ServiceManager::PackageInterfaceMap::insertService( std::unique_ptr &&service) { mInstanceMap.insert({service->getInstanceName(), std::move(service)}); } void ServiceManager::PackageInterfaceMap::sendPackageRegistrationNotification( const hidl_string &fqName, const hidl_string &instanceName) { for (auto it = mPackageListeners.begin(); it != mPackageListeners.end();) { auto ret = (*it)->onRegistration(fqName, instanceName, false /* preexisting */); if (ret.isOk()) { ++it; } else { LOG(ERROR) << "Dropping registration callback for " << fqName << "/" << instanceName << ": transport error."; it = mPackageListeners.erase(it); } } } void ServiceManager::PackageInterfaceMap::addPackageListener(sp listener) { for (const auto &instanceMapping : mInstanceMap) { const std::unique_ptr &service = instanceMapping.second; if (service->getService() == nullptr) { continue; } auto ret = listener->onRegistration( service->getInterfaceName(), service->getInstanceName(), true /* preexisting */); if (!ret.isOk()) { LOG(ERROR) << "Not adding package listener for " << service->getInterfaceName() << "/" << service->getInstanceName() << ": transport error " << "when sending notification for already registered instance."; return; } } mPackageListeners.push_back(listener); } bool ServiceManager::PackageInterfaceMap::removePackageListener(const wp& who) { bool found = false; for (auto it = mPackageListeners.begin(); it != mPackageListeners.end();) { if (interfacesEqual(*it, who.promote())) { it = mPackageListeners.erase(it); found = true; } else { ++it; } } return found; } bool ServiceManager::PackageInterfaceMap::removeServiceListener(const wp& who) { bool found = false; for (auto &servicePair : getInstanceMap()) { const std::unique_ptr &service = servicePair.second; found |= service->removeListener(who); } return found; } static void tryStartService(const std::string& fqName, const std::string& name) { using ::android::base::SetProperty; // The "happy path" here is starting up a service that is configured as a // lazy HAL, but we aren't sure that is the case. If the service doesn't // have an 'interface' entry in its .rc file OR if the service is already // running, then this will be a no-op. So, for instance, if a service is // deadlocked during startup, you will see this message repeatedly. LOG(INFO) << "Since " << fqName << "/" << name << " is not registered, trying to start it as a lazy HAL."; std::thread([=] { (void)SetProperty("ctl.interface_start", fqName + "/" + name); }).detach(); } // Methods from ::android::hidl::manager::V1_0::IServiceManager follow. Return> ServiceManager::get(const hidl_string& hidlFqName, const hidl_string& hidlName) { const std::string fqName = hidlFqName; const std::string name = hidlName; if (!mAcl.canGet(fqName, getBinderCallingContext())) { return nullptr; } HidlService* hidlService = lookup(fqName, name); if (hidlService == nullptr) { tryStartService(fqName, name); return nullptr; } sp service = hidlService->getService(); if (service == nullptr) { tryStartService(fqName, name); return nullptr; } // Let HidlService know that we handed out a client. If the client drops the service before the // next time handleClientCallbacks is called, it will still know that the service had been handed out. hidlService->guaranteeClient(); forEachExistingService([&] (HidlService *otherService) { if (otherService != hidlService && interfacesEqual(service, otherService->getService())) { otherService->guaranteeClient(); } return true; }); // This is executed immediately after the binder driver confirms the transaction. The driver // will update the appropriate data structures to reflect the fact that the client now has the // service this function is returning. Nothing else can update the HidlService at the same // time. This will run before anything else can modify the HidlService which is owned by this // object, so it will be in the same state that it was when this function returns. hardware::addPostCommandTask([hidlService] { hidlService->handleClientCallbacks(false /* isCalledOnInterval */, 1 /*knownClientCount*/); }); return service; } Return ServiceManager::add(const hidl_string& name, const sp& service) { bool addSuccess = false; if (service == nullptr) { return false; } auto pidcon = getBinderCallingContext(); auto ret = service->interfaceChain([&](const auto &interfaceChain) { addSuccess = addImpl(name, service, interfaceChain, pidcon); }); if (!ret.isOk()) { LOG(ERROR) << "Failed to retrieve interface chain: " << ret.description(); return false; } return addSuccess; } bool ServiceManager::addImpl(const std::string& name, const sp& service, const hidl_vec& interfaceChain, const AccessControl::CallingContext& callingContext) { if (interfaceChain.size() == 0) { LOG(WARNING) << "Empty interface chain for " << name; return false; } // First, verify you're allowed to add() the whole interface hierarchy for(size_t i = 0; i < interfaceChain.size(); i++) { const std::string fqName = interfaceChain[i]; if (!mAcl.canAdd(fqName, callingContext)) { return false; } } // Detect duplicate registration if (interfaceChain.size() > 1) { // second to last entry should be the highest base class other than IBase. const std::string baseFqName = interfaceChain[interfaceChain.size() - 2]; const HidlService *hidlService = lookup(baseFqName, name); if (hidlService != nullptr && hidlService->getService() != nullptr) { // This shouldn't occur during normal operation. Here are some cases where // it might get hit: // - bad configuration (service installed on device multiple times) // - race between death notification and a new service being registered // (previous logs should indicate a separate problem) const std::string childFqName = interfaceChain[0]; pid_t newServicePid = IPCThreadState::self()->getCallingPid(); pid_t oldServicePid = hidlService->getDebugPid(); LOG(WARNING) << "Detected instance of " << childFqName << " (pid: " << newServicePid << ") registering over instance of or with base of " << baseFqName << " (pid: " << oldServicePid << ")."; } } // Unregister superclass if subclass is registered over it { // For IBar extends IFoo if IFoo/default is being registered, remove // IBar/default. This makes sure the following two things are equivalent // 1). IBar::castFrom(IFoo::getService(X)) // 2). IBar::getService(X) // assuming that IBar is declared in the device manifest and there // is also not an IBaz extends IFoo and there is no race. const std::string childFqName = interfaceChain[0]; const HidlService *hidlService = lookup(childFqName, name); if (hidlService != nullptr) { const sp remove = hidlService->getService(); if (remove != nullptr) { const std::string instanceName = name; removeService(remove, &instanceName /* restrictToInstanceName */); } } } for(size_t i = 0; i < interfaceChain.size(); i++) { const std::string fqName = interfaceChain[i]; PackageInterfaceMap &ifaceMap = mServiceMap[fqName]; HidlService *hidlService = ifaceMap.lookup(name); if (hidlService == nullptr) { ifaceMap.insertService( std::make_unique(fqName, name, service, callingContext.pid)); } else { hidlService->setService(service, callingContext.pid); } ifaceMap.sendPackageRegistrationNotification(fqName, name); } bool linkRet = service->linkToDeath(this, kServiceDiedCookie).withDefault(false); if (!linkRet) { LOG(ERROR) << "Could not link to death for " << interfaceChain[0] << "/" << name; } return true; } Return ServiceManager::getTransport(const hidl_string& fqName, const hidl_string& name) { using ::android::hardware::getTransport; if (!mAcl.canGet(fqName, getBinderCallingContext())) { return Transport::EMPTY; } switch (getTransport(fqName, name)) { case vintf::Transport::HWBINDER: return Transport::HWBINDER; case vintf::Transport::PASSTHROUGH: return Transport::PASSTHROUGH; case vintf::Transport::EMPTY: default: return Transport::EMPTY; } } Return ServiceManager::list(list_cb _hidl_cb) { if (!mAcl.canList(getBinderCallingContext())) { _hidl_cb({}); return Void(); } hidl_vec list; list.resize(countExistingService()); size_t idx = 0; forEachExistingService([&] (const HidlService *service) { list[idx++] = service->string(); return true; // continue }); _hidl_cb(list); return Void(); } Return ServiceManager::listByInterface(const hidl_string& fqName, listByInterface_cb _hidl_cb) { if (!mAcl.canGet(fqName, getBinderCallingContext())) { _hidl_cb({}); return Void(); } auto ifaceIt = mServiceMap.find(fqName); if (ifaceIt == mServiceMap.end()) { _hidl_cb(hidl_vec()); return Void(); } const auto &instanceMap = ifaceIt->second.getInstanceMap(); hidl_vec list; size_t total = 0; for (const auto &serviceMapping : instanceMap) { const std::unique_ptr &service = serviceMapping.second; if (service->getService() == nullptr) continue; ++total; } list.resize(total); size_t idx = 0; for (const auto &serviceMapping : instanceMap) { const std::unique_ptr &service = serviceMapping.second; if (service->getService() == nullptr) continue; list[idx++] = service->getInstanceName(); } _hidl_cb(list); return Void(); } Return ServiceManager::registerForNotifications(const hidl_string& fqName, const hidl_string& name, const sp& callback) { if (callback == nullptr) { return false; } if (!mAcl.canGet(fqName, getBinderCallingContext())) { return false; } PackageInterfaceMap &ifaceMap = mServiceMap[fqName]; if (name.empty()) { bool ret = callback->linkToDeath(this, kPackageListenerDiedCookie).withDefault(false); if (!ret) { LOG(ERROR) << "Failed to register death recipient for " << fqName << "/" << name; return false; } ifaceMap.addPackageListener(callback); return true; } HidlService *service = ifaceMap.lookup(name); bool ret = callback->linkToDeath(this, kServiceListenerDiedCookie).withDefault(false); if (!ret) { LOG(ERROR) << "Failed to register death recipient for " << fqName << "/" << name; return false; } if (service == nullptr) { auto adding = std::make_unique(fqName, name); adding->addListener(callback); ifaceMap.insertService(std::move(adding)); } else { service->addListener(callback); } return true; } Return ServiceManager::unregisterForNotifications(const hidl_string& fqName, const hidl_string& name, const sp& callback) { if (callback == nullptr) { LOG(ERROR) << "Cannot unregister null callback for " << fqName << "/" << name; return false; } // NOTE: don't need ACL since callback is binder token, and if someone has gotten it, // then they already have access to it. if (fqName.empty()) { bool success = false; success |= removePackageListener(callback); success |= removeServiceListener(callback); return success; } PackageInterfaceMap &ifaceMap = mServiceMap[fqName]; if (name.empty()) { bool success = false; success |= ifaceMap.removePackageListener(callback); success |= ifaceMap.removeServiceListener(callback); return success; } HidlService *service = ifaceMap.lookup(name); if (service == nullptr) { return false; } return service->removeListener(callback); } Return ServiceManager::registerClientCallback(const hidl_string& hidlFqName, const hidl_string& hidlName, const sp& server, const sp& cb) { if (server == nullptr || cb == nullptr) return false; const std::string fqName = hidlFqName; const std::string name = hidlName; // only the server of the interface can register a client callback pid_t pid = IPCThreadState::self()->getCallingPid(); if (!mAcl.canAdd(fqName, getBinderCallingContext())) { return false; } HidlService* registered = lookup(fqName, name); if (registered == nullptr) { return false; } // sanity if (registered->getDebugPid() != pid) { LOG(WARNING) << "Only a server can register for client callbacks (for " << fqName << "/" << name << ")"; return false; } sp service = registered->getService(); if (!interfacesEqual(service, server)) { LOG(WARNING) << "Tried to register client callback for " << fqName << "/" << name << " but a different service is registered under this name."; return false; } bool linkRet = cb->linkToDeath(this, kClientCallbackDiedCookie).withDefault(false); if (!linkRet) { LOG(ERROR) << "Could not link to death for registerClientCallback"; return false; } // knownClientCount // - one from binder transaction (base here) // - one from hwservicemanager registered->addClientCallback(cb, 2 /*knownClientCount*/); return true; } Return ServiceManager::unregisterClientCallback(const sp& server, const sp& cb) { if (cb == nullptr) return false; bool removed = false; forEachExistingService([&] (HidlService *service) { if (server == nullptr || interfacesEqual(service->getService(), server)) { removed |= service->removeClientCallback(cb); } return true; // continue }); return removed; } void ServiceManager::handleClientCallbacks() { forEachServiceEntry([&] (HidlService *service) { // hwservicemanager will hold one reference, so knownClientCount is 1. service->handleClientCallbacks(true /* isCalledOnInterval */, 1 /*knownClientCount*/); return true; // continue }); } Return ServiceManager::addWithChain(const hidl_string& name, const sp& service, const hidl_vec& chain) { if (service == nullptr) { return false; } auto callingContext = getBinderCallingContext(); return addImpl(name, service, chain, callingContext); } Return ServiceManager::listManifestByInterface(const hidl_string& fqName, listManifestByInterface_cb _hidl_cb) { if (!mAcl.canGet(fqName, getBinderCallingContext())) { _hidl_cb({}); return Void(); } std::set instances = getInstances(fqName); hidl_vec ret(instances.begin(), instances.end()); _hidl_cb(ret); return Void(); } Return ServiceManager::tryUnregister(const hidl_string& hidlFqName, const hidl_string& hidlName, const sp& service) { const std::string fqName = hidlFqName; const std::string name = hidlName; if (service == nullptr) { return false; } if (!mAcl.canAdd(fqName, getBinderCallingContext())) { return false; } HidlService* registered = lookup(fqName, name); // sanity pid_t pid = IPCThreadState::self()->getCallingPid(); if (registered->getDebugPid() != pid) { LOG(WARNING) << "Only a server can unregister itself (for " << fqName << "/" << name << ")"; return false; } sp server = registered->getService(); if (!interfacesEqual(service, server)) { LOG(WARNING) << "Tried to unregister for " << fqName << "/" << name << " but a different service is registered under this name."; return false; } // knownClientCount // - one from binder transaction (base here) // - one from hwservicemanager bool clients = registered->forceHandleClientCallbacks(false /*isCalledOnInterval*/, 2 /*knownClientCount*/); if (clients) { // client callbacks are either disabled or there are other clients LOG(INFO) << "Tried to unregister for " << fqName << "/" << name << " but there are clients: " << clients; return false; } // will remove entire parent hierarchy bool success = removeService(service, &name /*restrictToInstanceName*/); if (registered->getService() != nullptr) { LOG(ERROR) << "Bad state. Unregistration failed for " << fqName << "/" << name << "."; return false; } return success; } Return ServiceManager::debugDump(debugDump_cb _cb) { if (!mAcl.canList(getBinderCallingContext())) { _cb({}); return Void(); } std::vector list; forEachServiceEntry([&] (const HidlService *service) { hidl_vec clientPids; clientPids.resize(service->getPassthroughClients().size()); size_t i = 0; for (pid_t p : service->getPassthroughClients()) { clientPids[i++] = p; } list.push_back({ .interfaceName = service->getInterfaceName(), .instanceName = service->getInstanceName(), .pid = service->getDebugPid(), .clientPids = clientPids, .arch = ::android::hidl::base::V1_0::DebugInfo::Architecture::UNKNOWN }); return true; // continue }); _cb(list); return Void(); } Return ServiceManager::registerPassthroughClient(const hidl_string &fqName, const hidl_string &name) { auto callingContext = getBinderCallingContext(); if (!mAcl.canGet(fqName, callingContext)) { /* We guard this function with "get", because it's typically used in * the getService() path, albeit for a passthrough service in this * case */ return Void(); } PackageInterfaceMap &ifaceMap = mServiceMap[fqName]; if (name.empty()) { LOG(WARNING) << "registerPassthroughClient encounters empty instance name for " << fqName.c_str(); return Void(); } HidlService *service = ifaceMap.lookup(name); if (service == nullptr) { auto adding = std::make_unique(fqName, name); adding->registerPassthroughClient(callingContext.pid); ifaceMap.insertService(std::move(adding)); } else { service->registerPassthroughClient(callingContext.pid); } return Void(); } bool ServiceManager::removeService(const wp& who, const std::string* restrictToInstanceName) { bool keepInstance = false; bool removed = false; for (auto &interfaceMapping : mServiceMap) { auto &instanceMap = interfaceMapping.second.getInstanceMap(); for (auto &servicePair : instanceMap) { const std::string &instanceName = servicePair.first; const std::unique_ptr &service = servicePair.second; if (interfacesEqual(service->getService(), who.promote())) { if (restrictToInstanceName != nullptr && *restrictToInstanceName != instanceName) { // We cannot remove all instances of this service, so we don't return that it // has been entirely removed. keepInstance = true; continue; } service->setService(nullptr, static_cast(IServiceManager::PidConstant::NO_PID)); removed = true; } } } return !keepInstance && removed; } bool ServiceManager::removePackageListener(const wp& who) { bool found = false; for (auto &interfaceMapping : mServiceMap) { found |= interfaceMapping.second.removePackageListener(who); } return found; } bool ServiceManager::removeServiceListener(const wp& who) { bool found = false; for (auto &interfaceMapping : mServiceMap) { auto &packageInterfaceMap = interfaceMapping.second; found |= packageInterfaceMap.removeServiceListener(who); } return found; } } // namespace implementation } // namespace manager } // namespace hidl } // namespace android