|  | /* | 
|  | * 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 "BpBinder" | 
|  | //#define LOG_NDEBUG 0 | 
|  |  | 
|  | #include <binder/BpBinder.h> | 
|  |  | 
|  | #include <binder/IPCThreadState.h> | 
|  | #include <binder/IResultReceiver.h> | 
|  | #include <cutils/compiler.h> | 
|  | #include <utils/Log.h> | 
|  |  | 
|  | #include <stdio.h> | 
|  |  | 
|  | //#undef ALOGV | 
|  | //#define ALOGV(...) fprintf(stderr, __VA_ARGS__) | 
|  |  | 
|  | namespace android { | 
|  |  | 
|  | // --------------------------------------------------------------------------- | 
|  |  | 
|  | Mutex BpBinder::sTrackingLock; | 
|  | std::unordered_map<int32_t,uint32_t> BpBinder::sTrackingMap; | 
|  | int BpBinder::sNumTrackedUids = 0; | 
|  | std::atomic_bool BpBinder::sCountByUidEnabled(false); | 
|  | binder_proxy_limit_callback BpBinder::sLimitCallback; | 
|  | bool BpBinder::sBinderProxyThrottleCreate = false; | 
|  |  | 
|  | // Arbitrarily high value that probably distinguishes a bad behaving app | 
|  | uint32_t BpBinder::sBinderProxyCountHighWatermark = 2500; | 
|  | // Another arbitrary value a binder count needs to drop below before another callback will be called | 
|  | uint32_t BpBinder::sBinderProxyCountLowWatermark = 2000; | 
|  |  | 
|  | enum { | 
|  | LIMIT_REACHED_MASK = 0x80000000,        // A flag denoting that the limit has been reached | 
|  | COUNTING_VALUE_MASK = 0x7FFFFFFF,       // A mask of the remaining bits for the count value | 
|  | }; | 
|  |  | 
|  | BpBinder::ObjectManager::ObjectManager() | 
|  | { | 
|  | } | 
|  |  | 
|  | BpBinder::ObjectManager::~ObjectManager() | 
|  | { | 
|  | kill(); | 
|  | } | 
|  |  | 
|  | void BpBinder::ObjectManager::attach( | 
|  | const void* objectID, void* object, void* cleanupCookie, | 
|  | IBinder::object_cleanup_func func) | 
|  | { | 
|  | entry_t e; | 
|  | e.object = object; | 
|  | e.cleanupCookie = cleanupCookie; | 
|  | e.func = func; | 
|  |  | 
|  | if (mObjects.indexOfKey(objectID) >= 0) { | 
|  | ALOGE("Trying to attach object ID %p to binder ObjectManager %p with object %p, but object ID already in use", | 
|  | objectID, this,  object); | 
|  | return; | 
|  | } | 
|  |  | 
|  | mObjects.add(objectID, e); | 
|  | } | 
|  |  | 
|  | void* BpBinder::ObjectManager::find(const void* objectID) const | 
|  | { | 
|  | const ssize_t i = mObjects.indexOfKey(objectID); | 
|  | if (i < 0) return nullptr; | 
|  | return mObjects.valueAt(i).object; | 
|  | } | 
|  |  | 
|  | void BpBinder::ObjectManager::detach(const void* objectID) | 
|  | { | 
|  | mObjects.removeItem(objectID); | 
|  | } | 
|  |  | 
|  | void BpBinder::ObjectManager::kill() | 
|  | { | 
|  | const size_t N = mObjects.size(); | 
|  | ALOGV("Killing %zu objects in manager %p", N, this); | 
|  | for (size_t i=0; i<N; i++) { | 
|  | const entry_t& e = mObjects.valueAt(i); | 
|  | if (e.func != nullptr) { | 
|  | e.func(mObjects.keyAt(i), e.object, e.cleanupCookie); | 
|  | } | 
|  | } | 
|  |  | 
|  | mObjects.clear(); | 
|  | } | 
|  |  | 
|  | // --------------------------------------------------------------------------- | 
|  |  | 
|  |  | 
|  | BpBinder* BpBinder::create(int32_t handle) { | 
|  | int32_t trackedUid = -1; | 
|  | if (sCountByUidEnabled) { | 
|  | trackedUid = IPCThreadState::self()->getCallingUid(); | 
|  | AutoMutex _l(sTrackingLock); | 
|  | uint32_t trackedValue = sTrackingMap[trackedUid]; | 
|  | if (CC_UNLIKELY(trackedValue & LIMIT_REACHED_MASK)) { | 
|  | if (sBinderProxyThrottleCreate) { | 
|  | return nullptr; | 
|  | } | 
|  | } else { | 
|  | if ((trackedValue & COUNTING_VALUE_MASK) >= sBinderProxyCountHighWatermark) { | 
|  | ALOGE("Too many binder proxy objects sent to uid %d from uid %d (%d proxies held)", | 
|  | getuid(), trackedUid, trackedValue); | 
|  | sTrackingMap[trackedUid] |= LIMIT_REACHED_MASK; | 
|  | if (sLimitCallback) sLimitCallback(trackedUid); | 
|  | if (sBinderProxyThrottleCreate) { | 
|  | ALOGI("Throttling binder proxy creates from uid %d in uid %d until binder proxy" | 
|  | " count drops below %d", | 
|  | trackedUid, getuid(), sBinderProxyCountLowWatermark); | 
|  | return nullptr; | 
|  | } | 
|  | } | 
|  | } | 
|  | sTrackingMap[trackedUid]++; | 
|  | } | 
|  | return new BpBinder(handle, trackedUid); | 
|  | } | 
|  |  | 
|  | BpBinder::BpBinder(int32_t handle, int32_t trackedUid) | 
|  | : mHandle(handle) | 
|  | , mAlive(1) | 
|  | , mObitsSent(0) | 
|  | , mObituaries(nullptr) | 
|  | , mTrackedUid(trackedUid) | 
|  | { | 
|  | ALOGV("Creating BpBinder %p handle %d\n", this, mHandle); | 
|  |  | 
|  | extendObjectLifetime(OBJECT_LIFETIME_WEAK); | 
|  | IPCThreadState::self()->incWeakHandle(handle, this); | 
|  | } | 
|  |  | 
|  | int32_t BpBinder::handle() const { | 
|  | return mHandle; | 
|  | } | 
|  |  | 
|  | bool BpBinder::isDescriptorCached() const { | 
|  | Mutex::Autolock _l(mLock); | 
|  | return mDescriptorCache.size() ? true : false; | 
|  | } | 
|  |  | 
|  | const String16& BpBinder::getInterfaceDescriptor() const | 
|  | { | 
|  | if (isDescriptorCached() == false) { | 
|  | Parcel send, reply; | 
|  | // do the IPC without a lock held. | 
|  | status_t err = const_cast<BpBinder*>(this)->transact( | 
|  | INTERFACE_TRANSACTION, send, &reply); | 
|  | if (err == NO_ERROR) { | 
|  | String16 res(reply.readString16()); | 
|  | Mutex::Autolock _l(mLock); | 
|  | // mDescriptorCache could have been assigned while the lock was | 
|  | // released. | 
|  | if (mDescriptorCache.size() == 0) | 
|  | mDescriptorCache = res; | 
|  | } | 
|  | } | 
|  |  | 
|  | // we're returning a reference to a non-static object here. Usually this | 
|  | // is not something smart to do, however, with binder objects it is | 
|  | // (usually) safe because they are reference-counted. | 
|  |  | 
|  | return mDescriptorCache; | 
|  | } | 
|  |  | 
|  | bool BpBinder::isBinderAlive() const | 
|  | { | 
|  | return mAlive != 0; | 
|  | } | 
|  |  | 
|  | status_t BpBinder::pingBinder() | 
|  | { | 
|  | Parcel send; | 
|  | Parcel reply; | 
|  | return transact(PING_TRANSACTION, send, &reply); | 
|  | } | 
|  |  | 
|  | status_t BpBinder::dump(int fd, const Vector<String16>& args) | 
|  | { | 
|  | Parcel send; | 
|  | Parcel reply; | 
|  | send.writeFileDescriptor(fd); | 
|  | const size_t numArgs = args.size(); | 
|  | send.writeInt32(numArgs); | 
|  | for (size_t i = 0; i < numArgs; i++) { | 
|  | send.writeString16(args[i]); | 
|  | } | 
|  | status_t err = transact(DUMP_TRANSACTION, send, &reply); | 
|  | return err; | 
|  | } | 
|  |  | 
|  | // NOLINTNEXTLINE(google-default-arguments) | 
|  | status_t BpBinder::transact( | 
|  | uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) | 
|  | { | 
|  | // Once a binder has died, it will never come back to life. | 
|  | if (mAlive) { | 
|  | status_t status = IPCThreadState::self()->transact( | 
|  | mHandle, code, data, reply, flags); | 
|  | if (status == DEAD_OBJECT) mAlive = 0; | 
|  |  | 
|  | if (reply != nullptr) { | 
|  | reply->setTransactingBinder(this); | 
|  | } | 
|  |  | 
|  | return status; | 
|  | } | 
|  |  | 
|  | return DEAD_OBJECT; | 
|  | } | 
|  |  | 
|  | // NOLINTNEXTLINE(google-default-arguments) | 
|  | status_t BpBinder::linkToDeath( | 
|  | const sp<DeathRecipient>& recipient, void* cookie, uint32_t flags) | 
|  | { | 
|  | Obituary ob; | 
|  | ob.recipient = recipient; | 
|  | ob.cookie = cookie; | 
|  | ob.flags = flags; | 
|  |  | 
|  | LOG_ALWAYS_FATAL_IF(recipient == nullptr, | 
|  | "linkToDeath(): recipient must be non-NULL"); | 
|  |  | 
|  | { | 
|  | AutoMutex _l(mLock); | 
|  |  | 
|  | if (!mObitsSent) { | 
|  | if (!mObituaries) { | 
|  | mObituaries = new Vector<Obituary>; | 
|  | if (!mObituaries) { | 
|  | return NO_MEMORY; | 
|  | } | 
|  | ALOGV("Requesting death notification: %p handle %d\n", this, mHandle); | 
|  | getWeakRefs()->incWeak(this); | 
|  | IPCThreadState* self = IPCThreadState::self(); | 
|  | self->requestDeathNotification(mHandle, this); | 
|  | self->flushCommands(); | 
|  | } | 
|  | ssize_t res = mObituaries->add(ob); | 
|  | return res >= (ssize_t)NO_ERROR ? (status_t)NO_ERROR : res; | 
|  | } | 
|  | } | 
|  |  | 
|  | return DEAD_OBJECT; | 
|  | } | 
|  |  | 
|  | // NOLINTNEXTLINE(google-default-arguments) | 
|  | status_t BpBinder::unlinkToDeath( | 
|  | const wp<DeathRecipient>& recipient, void* cookie, uint32_t flags, | 
|  | wp<DeathRecipient>* outRecipient) | 
|  | { | 
|  | AutoMutex _l(mLock); | 
|  |  | 
|  | if (mObitsSent) { | 
|  | return DEAD_OBJECT; | 
|  | } | 
|  |  | 
|  | const size_t N = mObituaries ? mObituaries->size() : 0; | 
|  | for (size_t i=0; i<N; i++) { | 
|  | const Obituary& obit = mObituaries->itemAt(i); | 
|  | if ((obit.recipient == recipient | 
|  | || (recipient == nullptr && obit.cookie == cookie)) | 
|  | && obit.flags == flags) { | 
|  | if (outRecipient != nullptr) { | 
|  | *outRecipient = mObituaries->itemAt(i).recipient; | 
|  | } | 
|  | mObituaries->removeAt(i); | 
|  | if (mObituaries->size() == 0) { | 
|  | ALOGV("Clearing death notification: %p handle %d\n", this, mHandle); | 
|  | IPCThreadState* self = IPCThreadState::self(); | 
|  | self->clearDeathNotification(mHandle, this); | 
|  | self->flushCommands(); | 
|  | delete mObituaries; | 
|  | mObituaries = nullptr; | 
|  | } | 
|  | return NO_ERROR; | 
|  | } | 
|  | } | 
|  |  | 
|  | return NAME_NOT_FOUND; | 
|  | } | 
|  |  | 
|  | void BpBinder::sendObituary() | 
|  | { | 
|  | ALOGV("Sending obituary for proxy %p handle %d, mObitsSent=%s\n", | 
|  | this, mHandle, mObitsSent ? "true" : "false"); | 
|  |  | 
|  | mAlive = 0; | 
|  | if (mObitsSent) return; | 
|  |  | 
|  | mLock.lock(); | 
|  | Vector<Obituary>* obits = mObituaries; | 
|  | if(obits != nullptr) { | 
|  | ALOGV("Clearing sent death notification: %p handle %d\n", this, mHandle); | 
|  | IPCThreadState* self = IPCThreadState::self(); | 
|  | self->clearDeathNotification(mHandle, this); | 
|  | self->flushCommands(); | 
|  | mObituaries = nullptr; | 
|  | } | 
|  | mObitsSent = 1; | 
|  | mLock.unlock(); | 
|  |  | 
|  | ALOGV("Reporting death of proxy %p for %zu recipients\n", | 
|  | this, obits ? obits->size() : 0U); | 
|  |  | 
|  | if (obits != nullptr) { | 
|  | const size_t N = obits->size(); | 
|  | for (size_t i=0; i<N; i++) { | 
|  | reportOneDeath(obits->itemAt(i)); | 
|  | } | 
|  |  | 
|  | delete obits; | 
|  | } | 
|  | } | 
|  |  | 
|  | void BpBinder::reportOneDeath(const Obituary& obit) | 
|  | { | 
|  | sp<DeathRecipient> recipient = obit.recipient.promote(); | 
|  | ALOGV("Reporting death to recipient: %p\n", recipient.get()); | 
|  | if (recipient == nullptr) return; | 
|  |  | 
|  | recipient->binderDied(this); | 
|  | } | 
|  |  | 
|  |  | 
|  | void BpBinder::attachObject( | 
|  | const void* objectID, void* object, void* cleanupCookie, | 
|  | object_cleanup_func func) | 
|  | { | 
|  | AutoMutex _l(mLock); | 
|  | ALOGV("Attaching object %p to binder %p (manager=%p)", object, this, &mObjects); | 
|  | mObjects.attach(objectID, object, cleanupCookie, func); | 
|  | } | 
|  |  | 
|  | void* BpBinder::findObject(const void* objectID) const | 
|  | { | 
|  | AutoMutex _l(mLock); | 
|  | return mObjects.find(objectID); | 
|  | } | 
|  |  | 
|  | void BpBinder::detachObject(const void* objectID) | 
|  | { | 
|  | AutoMutex _l(mLock); | 
|  | mObjects.detach(objectID); | 
|  | } | 
|  |  | 
|  | BpBinder* BpBinder::remoteBinder() | 
|  | { | 
|  | return this; | 
|  | } | 
|  |  | 
|  | BpBinder::~BpBinder() | 
|  | { | 
|  | ALOGV("Destroying BpBinder %p handle %d\n", this, mHandle); | 
|  |  | 
|  | IPCThreadState* ipc = IPCThreadState::self(); | 
|  |  | 
|  | if (mTrackedUid >= 0) { | 
|  | AutoMutex _l(sTrackingLock); | 
|  | uint32_t trackedValue = sTrackingMap[mTrackedUid]; | 
|  | if (CC_UNLIKELY((trackedValue & COUNTING_VALUE_MASK) == 0)) { | 
|  | ALOGE("Unexpected Binder Proxy tracking decrement in %p handle %d\n", this, mHandle); | 
|  | } else { | 
|  | if (CC_UNLIKELY( | 
|  | (trackedValue & LIMIT_REACHED_MASK) && | 
|  | ((trackedValue & COUNTING_VALUE_MASK) <= sBinderProxyCountLowWatermark) | 
|  | )) { | 
|  | ALOGI("Limit reached bit reset for uid %d (fewer than %d proxies from uid %d held)", | 
|  | getuid(), mTrackedUid, sBinderProxyCountLowWatermark); | 
|  | sTrackingMap[mTrackedUid] &= ~LIMIT_REACHED_MASK; | 
|  | } | 
|  | if (--sTrackingMap[mTrackedUid] == 0) { | 
|  | sTrackingMap.erase(mTrackedUid); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | if (ipc) { | 
|  | ipc->expungeHandle(mHandle, this); | 
|  | ipc->decWeakHandle(mHandle); | 
|  | } | 
|  | } | 
|  |  | 
|  | void BpBinder::onFirstRef() | 
|  | { | 
|  | ALOGV("onFirstRef BpBinder %p handle %d\n", this, mHandle); | 
|  | IPCThreadState* ipc = IPCThreadState::self(); | 
|  | if (ipc) ipc->incStrongHandle(mHandle, this); | 
|  | } | 
|  |  | 
|  | void BpBinder::onLastStrongRef(const void* /*id*/) | 
|  | { | 
|  | ALOGV("onLastStrongRef BpBinder %p handle %d\n", this, mHandle); | 
|  | IF_ALOGV() { | 
|  | printRefs(); | 
|  | } | 
|  | IPCThreadState* ipc = IPCThreadState::self(); | 
|  | if (ipc) ipc->decStrongHandle(mHandle); | 
|  |  | 
|  | mLock.lock(); | 
|  | Vector<Obituary>* obits = mObituaries; | 
|  | if(obits != nullptr) { | 
|  | if (!obits->isEmpty()) { | 
|  | ALOGI("onLastStrongRef automatically unlinking death recipients"); | 
|  | } | 
|  |  | 
|  | if (ipc) ipc->clearDeathNotification(mHandle, this); | 
|  | mObituaries = nullptr; | 
|  | } | 
|  | mLock.unlock(); | 
|  |  | 
|  | if (obits != nullptr) { | 
|  | // XXX Should we tell any remaining DeathRecipient | 
|  | // objects that the last strong ref has gone away, so they | 
|  | // are no longer linked? | 
|  | delete obits; | 
|  | } | 
|  | } | 
|  |  | 
|  | bool BpBinder::onIncStrongAttempted(uint32_t /*flags*/, const void* /*id*/) | 
|  | { | 
|  | ALOGV("onIncStrongAttempted BpBinder %p handle %d\n", this, mHandle); | 
|  | IPCThreadState* ipc = IPCThreadState::self(); | 
|  | return ipc ? ipc->attemptIncStrongHandle(mHandle) == NO_ERROR : false; | 
|  | } | 
|  |  | 
|  | uint32_t BpBinder::getBinderProxyCount(uint32_t uid) | 
|  | { | 
|  | AutoMutex _l(sTrackingLock); | 
|  | auto it = sTrackingMap.find(uid); | 
|  | if (it != sTrackingMap.end()) { | 
|  | return it->second & COUNTING_VALUE_MASK; | 
|  | } | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | void BpBinder::getCountByUid(Vector<uint32_t>& uids, Vector<uint32_t>& counts) | 
|  | { | 
|  | AutoMutex _l(sTrackingLock); | 
|  | uids.setCapacity(sTrackingMap.size()); | 
|  | counts.setCapacity(sTrackingMap.size()); | 
|  | for (const auto& it : sTrackingMap) { | 
|  | uids.push_back(it.first); | 
|  | counts.push_back(it.second & COUNTING_VALUE_MASK); | 
|  | } | 
|  | } | 
|  |  | 
|  | void BpBinder::enableCountByUid() { sCountByUidEnabled.store(true); } | 
|  | void BpBinder::disableCountByUid() { sCountByUidEnabled.store(false); } | 
|  | void BpBinder::setCountByUidEnabled(bool enable) { sCountByUidEnabled.store(enable); } | 
|  |  | 
|  | void BpBinder::setLimitCallback(binder_proxy_limit_callback cb) { | 
|  | AutoMutex _l(sTrackingLock); | 
|  | sLimitCallback = cb; | 
|  | } | 
|  |  | 
|  | void BpBinder::setBinderProxyCountWatermarks(int high, int low) { | 
|  | AutoMutex _l(sTrackingLock); | 
|  | sBinderProxyCountHighWatermark = high; | 
|  | sBinderProxyCountLowWatermark = low; | 
|  | } | 
|  |  | 
|  | // --------------------------------------------------------------------------- | 
|  |  | 
|  | }; // namespace android |