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/*
* Copyright (C) 2018 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.
*/
#pragma once
#include <android/binder_ibinder.h>
#include <android/binder_shell.h>
#include "ibinder_internal.h"
#include <atomic>
#include <mutex>
#include <optional>
#include <vector>
#include <binder/Binder.h>
#include <binder/IBinder.h>
#include <utils/Vector.h>
inline bool isUserCommand(transaction_code_t code) {
return code >= FIRST_CALL_TRANSACTION && code <= LAST_CALL_TRANSACTION;
}
struct ABBinder;
struct ABpBinder;
struct AIBinder : public virtual ::android::RefBase {
explicit AIBinder(const AIBinder_Class* clazz);
virtual ~AIBinder();
bool associateClass(const AIBinder_Class* clazz);
const AIBinder_Class* getClass() const { return mClazz; }
virtual ::android::sp<::android::IBinder> getBinder() = 0;
virtual ABBinder* asABBinder() { return nullptr; }
virtual ABpBinder* asABpBinder() { return nullptr; }
bool isRemote() const {
::android::sp<::android::IBinder> binder = const_cast<AIBinder*>(this)->getBinder();
return binder->remoteBinder() != nullptr;
}
private:
std::optional<bool> associateClassInternal(const AIBinder_Class* clazz,
const ::android::String16& newDescriptor, bool set);
// AIBinder instance is instance of this class for a local object. In order to transact on a
// remote object, this also must be set for simplicity (although right now, only the
// interfaceDescriptor from it is used).
const AIBinder_Class* mClazz;
std::mutex mClazzMutex;
};
// This is a local AIBinder object with a known class.
struct ABBinder : public AIBinder, public ::android::BBinder {
virtual ~ABBinder();
void* getUserData() { return mUserData; }
::android::sp<::android::IBinder> getBinder() override { return this; }
ABBinder* asABBinder() override { return this; }
const ::android::String16& getInterfaceDescriptor() const override;
::android::status_t dump(int fd, const ::android::Vector<::android::String16>& args) override;
::android::status_t onTransact(uint32_t code, const ::android::Parcel& data,
::android::Parcel* reply, binder_flags_t flags) override;
private:
ABBinder(const AIBinder_Class* clazz, void* userData);
// only thing that should create an ABBinder
friend AIBinder* AIBinder_new(const AIBinder_Class*, void*);
// Can contain implementation if this is a local binder. This can still be nullptr for a local
// binder. If it is nullptr, the implication is the implementation state is entirely external to
// this object and the functionality provided in the AIBinder_Class is sufficient.
void* mUserData;
};
// This binder object may be remote or local (even though it is 'Bp'). The implication if it is
// local is that it is an IBinder object created outside of the domain of libbinder_ndk.
struct ABpBinder : public AIBinder, public ::android::BpRefBase {
// Looks up to see if this object has or is an existing ABBinder or ABpBinder object, otherwise
// it creates an ABpBinder object.
static ::android::sp<AIBinder> lookupOrCreateFromBinder(
const ::android::sp<::android::IBinder>& binder);
virtual ~ABpBinder();
void onLastStrongRef(const void* id) override;
::android::sp<::android::IBinder> getBinder() override { return remote(); }
ABpBinder* asABpBinder() override { return this; }
private:
explicit ABpBinder(const ::android::sp<::android::IBinder>& binder);
};
struct AIBinder_Class {
AIBinder_Class(const char* interfaceDescriptor, AIBinder_Class_onCreate onCreate,
AIBinder_Class_onDestroy onDestroy, AIBinder_Class_onTransact onTransact);
const ::android::String16& getInterfaceDescriptor() const { return mWideInterfaceDescriptor; }
const char* getInterfaceDescriptorUtf8() const { return mInterfaceDescriptor.c_str(); }
// required to be non-null, implemented for every class
const AIBinder_Class_onCreate onCreate = nullptr;
const AIBinder_Class_onDestroy onDestroy = nullptr;
const AIBinder_Class_onTransact onTransact = nullptr;
// optional methods for a class
AIBinder_onDump onDump = nullptr;
AIBinder_handleShellCommand handleShellCommand = nullptr;
private:
// Copy of the raw char string for when we don't have to return UTF-16
const std::string mInterfaceDescriptor;
// This must be a String16 since BBinder virtual getInterfaceDescriptor returns a reference to
// one.
const ::android::String16 mWideInterfaceDescriptor;
};
// Ownership is like this (when linked to death):
//
// AIBinder_DeathRecipient -sp-> TransferDeathRecipient <-wp-> IBinder
//
// When the AIBinder_DeathRecipient is dropped, so are the actual underlying death recipients. When
// the IBinder dies, only a wp to it is kept.
struct AIBinder_DeathRecipient : ::android::RefBase {
// One of these is created for every linkToDeath. This is to be able to recover data when a
// binderDied receipt only gives us information about the IBinder.
struct TransferDeathRecipient : ::android::IBinder::DeathRecipient {
TransferDeathRecipient(const ::android::wp<::android::IBinder>& who, void* cookie,
const ::android::wp<AIBinder_DeathRecipient>& parentRecipient,
const AIBinder_DeathRecipient_onBinderDied onDied)
: mWho(who), mCookie(cookie), mParentRecipient(parentRecipient), mOnDied(onDied) {}
void binderDied(const ::android::wp<::android::IBinder>& who) override;
const ::android::wp<::android::IBinder>& getWho() { return mWho; }
void* getCookie() { return mCookie; }
private:
::android::wp<::android::IBinder> mWho;
void* mCookie;
::android::wp<AIBinder_DeathRecipient> mParentRecipient;
// This is kept separately from AIBinder_DeathRecipient in case the death recipient is
// deleted while the death notification is fired
const AIBinder_DeathRecipient_onBinderDied mOnDied;
};
explicit AIBinder_DeathRecipient(AIBinder_DeathRecipient_onBinderDied onDied);
binder_status_t linkToDeath(const ::android::sp<::android::IBinder>&, void* cookie);
binder_status_t unlinkToDeath(const ::android::sp<::android::IBinder>& binder, void* cookie);
private:
// When the user of this API deletes a Bp object but not the death recipient, the
// TransferDeathRecipient object can't be cleaned up. This is called whenever a new
// TransferDeathRecipient is linked, and it ensures that mDeathRecipients can't grow unbounded.
void pruneDeadTransferEntriesLocked();
std::mutex mDeathRecipientsMutex;
std::vector<::android::sp<TransferDeathRecipient>> mDeathRecipients;
AIBinder_DeathRecipient_onBinderDied mOnDied;
};