gecko-dev/ipc/glue/ProtocolUtils.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=4 et :
*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_ipc_ProtocolUtils_h
#define mozilla_ipc_ProtocolUtils_h 1
#include "base/id_map.h"
#include "base/process.h"
#include "base/process_util.h"
#include "chrome/common/ipc_message_utils.h"
#include "prenv.h"
#include "IPCMessageStart.h"
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/Attributes.h"
#include "mozilla/ipc/ByteBuf.h"
#include "mozilla/ipc/FileDescriptor.h"
#include "mozilla/ipc/MessageChannel.h"
#include "mozilla/ipc/Shmem.h"
#include "mozilla/ipc/Transport.h"
#include "mozilla/ipc/MessageLink.h"
#include "mozilla/recordreplay/ChildIPC.h"
#include "mozilla/LinkedList.h"
#include "mozilla/Maybe.h"
#include "mozilla/MozPromise.h"
#include "mozilla/Mutex.h"
#include "mozilla/NotNull.h"
#include "mozilla/Scoped.h"
#include "mozilla/UniquePtr.h"
#include "MainThreadUtils.h"
#include "nsICrashReporter.h"
#if defined(ANDROID) && defined(DEBUG)
# include <android/log.h>
#endif
template <typename T>
class nsTHashtable;
template <typename T>
class nsPtrHashKey;
// WARNING: this takes into account the private, special-message-type
// enum in ipc_channel.h. They need to be kept in sync.
namespace {
// XXX the max message ID is actually kuint32max now ... when this
// changed, the assumptions of the special message IDs changed in that
// they're not carving out messages from likely-unallocated space, but
// rather carving out messages from the end of space allocated to
// protocol 0. Oops! We can get away with this until protocol 0
// starts approaching its 65,536th message.
enum {
BUILD_IDS_MATCH_MESSAGE_TYPE = kuint16max - 8,
BUILD_ID_MESSAGE_TYPE = kuint16max - 7, // unused
CHANNEL_OPENED_MESSAGE_TYPE = kuint16max - 6,
SHMEM_DESTROYED_MESSAGE_TYPE = kuint16max - 5,
SHMEM_CREATED_MESSAGE_TYPE = kuint16max - 4,
GOODBYE_MESSAGE_TYPE = kuint16max - 3,
CANCEL_MESSAGE_TYPE = kuint16max - 2,
// kuint16max - 1 is used by ipc_channel.h.
};
} // namespace
class nsIEventTarget;
namespace mozilla {
class SchedulerGroup;
namespace dom {
class ContentParent;
} // namespace dom
namespace net {
class NeckoParent;
} // namespace net
namespace ipc {
#ifdef FUZZING
class ProtocolFuzzerHelper;
#endif
class MessageChannel;
#ifdef XP_WIN
const base::ProcessHandle kInvalidProcessHandle = INVALID_HANDLE_VALUE;
// In theory, on Windows, this is a valid process ID, but in practice they are
// currently divisible by four. Process IDs share the kernel handle allocation
// code and they are guaranteed to be divisible by four.
// As this could change for process IDs we shouldn't generally rely on this
// property, however even if that were to change, it seems safe to rely on this
// particular value never being used.
const base::ProcessId kInvalidProcessId = kuint32max;
#else
const base::ProcessHandle kInvalidProcessHandle = -1;
const base::ProcessId kInvalidProcessId = -1;
#endif
// Scoped base::ProcessHandle to ensure base::CloseProcessHandle is called.
struct ScopedProcessHandleTraits {
typedef base::ProcessHandle type;
static type empty() { return kInvalidProcessHandle; }
static void release(type aProcessHandle) {
if (aProcessHandle && aProcessHandle != kInvalidProcessHandle) {
base::CloseProcessHandle(aProcessHandle);
}
}
};
typedef mozilla::Scoped<ScopedProcessHandleTraits> ScopedProcessHandle;
class ProtocolFdMapping;
class ProtocolCloneContext;
// Used to pass references to protocol actors across the wire.
// Actors created on the parent-side have a positive ID, and actors
// allocated on the child side have a negative ID.
struct ActorHandle {
int mId;
};
// What happens if Interrupt calls race?
enum RacyInterruptPolicy { RIPError, RIPChildWins, RIPParentWins };
class IToplevelProtocol;
class IProtocol : public HasResultCodes {
#ifdef FUZZING
friend class mozilla::ipc::ProtocolFuzzerHelper;
#endif
public:
enum ActorDestroyReason {
FailedConstructor,
Deletion,
AncestorDeletion,
NormalShutdown,
AbnormalShutdown
};
// A lot of the functionality of IProtocol only differs between toplevel
// protocols (IToplevelProtocol) and managed protocols (everything else).
// If we put such functionality in IProtocol via virtual methods, that
// means that *every* protocol inherits that functionality through said
// virtual methods, then every protocol needs a (largely redundant)
// entry in its vtable. That redundancy adds up quickly with several
// hundred protocols.
//
// This class (and its two subclasses) ensure that we don't have a bunch
// of redundant entries in protocol vtables: we have a single vtable per
// subclass, and then each protocol has its own instance of one of the
// subclasses. This setup makes things a bit slower, but the space
// savings are worth it.
class ProtocolState {
public:
ProtocolState() : mChannel(nullptr) {}
virtual ~ProtocolState() = default;
// Shared memory functions.
virtual Shmem::SharedMemory* CreateSharedMemory(
size_t, SharedMemory::SharedMemoryType, bool, int32_t*) = 0;
virtual Shmem::SharedMemory* LookupSharedMemory(int32_t) = 0;
virtual bool IsTrackingSharedMemory(Shmem::SharedMemory*) = 0;
virtual bool DestroySharedMemory(Shmem&) = 0;
// Protocol management functions.
virtual int32_t Register(IProtocol*) = 0;
virtual int32_t RegisterID(IProtocol*, int32_t) = 0;
virtual IProtocol* Lookup(int32_t) = 0;
virtual void Unregister(int32_t) = 0;
// Returns the event target set by SetEventTargetForActor() if available.
virtual nsIEventTarget* GetActorEventTarget() = 0;
virtual void SetEventTargetForActor(IProtocol* aActor,
nsIEventTarget* aEventTarget) = 0;
virtual void ReplaceEventTargetForActor(IProtocol* aActor,
nsIEventTarget* aEventTarget) = 0;
virtual already_AddRefed<nsIEventTarget> GetActorEventTarget(
IProtocol* aActor) = 0;
virtual const MessageChannel* GetIPCChannel() const = 0;
virtual MessageChannel* GetIPCChannel() = 0;
// XXX we have this weird setup where ProtocolState has an mChannel
// member, but it (probably?) only gets set for protocols that have
// a manager. That is, for toplevel protocols, this member is dead
// weight and should be removed, since toplevel protocols maintain
// their own channel.
void SetIPCChannel(MessageChannel* aChannel) { mChannel = aChannel; }
protected:
MessageChannel* mChannel;
};
// Managed protocols just forward all of their operations to the topmost
// managing protocol.
class ManagedState final : public ProtocolState {
public:
explicit ManagedState(IProtocol* aProtocol)
: ProtocolState(), mProtocol(aProtocol) {}
Shmem::SharedMemory* CreateSharedMemory(size_t,
SharedMemory::SharedMemoryType,
bool, int32_t*) override;
Shmem::SharedMemory* LookupSharedMemory(int32_t) override;
bool IsTrackingSharedMemory(Shmem::SharedMemory*) override;
bool DestroySharedMemory(Shmem&) override;
int32_t Register(IProtocol*) override;
int32_t RegisterID(IProtocol*, int32_t) override;
IProtocol* Lookup(int32_t) override;
void Unregister(int32_t) override;
nsIEventTarget* GetActorEventTarget() override;
void SetEventTargetForActor(IProtocol* aActor,
nsIEventTarget* aEventTarget) override;
void ReplaceEventTargetForActor(IProtocol* aActor,
nsIEventTarget* aEventTarget) override;
already_AddRefed<nsIEventTarget> GetActorEventTarget(
IProtocol* aActor) override;
const MessageChannel* GetIPCChannel() const override;
MessageChannel* GetIPCChannel() override;
private:
IProtocol* const mProtocol;
};
typedef base::ProcessId ProcessId;
typedef IPC::Message Message;
typedef IPC::MessageInfo MessageInfo;
explicit IProtocol(Side aSide)
: IProtocol(aSide, MakeUnique<ManagedState>(this)) {}
int32_t Register(IProtocol* aRouted) { return mState->Register(aRouted); }
int32_t RegisterID(IProtocol* aRouted, int32_t aId) {
return mState->RegisterID(aRouted, aId);
}
IProtocol* Lookup(int32_t aId) { return mState->Lookup(aId); }
void Unregister(int32_t aId) { return mState->Unregister(aId); }
virtual void RemoveManagee(int32_t, IProtocol*) = 0;
Shmem::SharedMemory* CreateSharedMemory(size_t aSize,
SharedMemory::SharedMemoryType aType,
bool aUnsafe, int32_t* aId) {
return mState->CreateSharedMemory(aSize, aType, aUnsafe, aId);
}
Shmem::SharedMemory* LookupSharedMemory(int32_t aId) {
return mState->LookupSharedMemory(aId);
}
bool IsTrackingSharedMemory(Shmem::SharedMemory* aSegment) {
return mState->IsTrackingSharedMemory(aSegment);
}
bool DestroySharedMemory(Shmem& aShmem) {
return mState->DestroySharedMemory(aShmem);
}
MessageChannel* GetIPCChannel() { return mState->GetIPCChannel(); }
const MessageChannel* GetIPCChannel() const {
return mState->GetIPCChannel();
}
void SetMiddlemanIPCChannel(MessageChannel* aChannel) {
// Middleman processes sometimes need to change the channel used by a
// protocol.
MOZ_RELEASE_ASSERT(recordreplay::IsMiddleman());
mState->SetIPCChannel(aChannel);
}
// XXX odd ducks, acknowledged
virtual ProcessId OtherPid() const;
Side GetSide() const { return mSide; }
void FatalError(const char* const aErrorMsg) const;
virtual void HandleFatalError(const char* aErrorMsg) const;
Maybe<IProtocol*> ReadActor(const IPC::Message* aMessage,
PickleIterator* aIter, bool aNullable,
const char* aActorDescription,
int32_t aProtocolTypeId);
virtual Result OnMessageReceived(const Message& aMessage) = 0;
virtual Result OnMessageReceived(const Message& aMessage,
Message*& aReply) = 0;
virtual Result OnCallReceived(const Message& aMessage, Message*& aReply) = 0;
virtual int32_t GetProtocolTypeId() = 0;
int32_t Id() const { return mId; }
IProtocol* Manager() const { return mManager; }
bool AllocShmem(size_t aSize, Shmem::SharedMemory::SharedMemoryType aType,
Shmem* aOutMem);
bool AllocUnsafeShmem(size_t aSize,
Shmem::SharedMemory::SharedMemoryType aType,
Shmem* aOutMem);
bool DeallocShmem(Shmem& aMem);
// Sets an event target to which all messages for aActor will be
// dispatched. This method must be called before right before the SendPFoo
// message for aActor is sent. And SendPFoo *must* be called if
// SetEventTargetForActor is called. The receiver when calling
// SetEventTargetForActor must be the actor that will be the manager for
// aActor.
void SetEventTargetForActor(IProtocol* aActor, nsIEventTarget* aEventTarget);
// Replace the event target for the messages of aActor. There must not be
// any messages of aActor in the task queue, or we might run into some
// unexpected behavior.
void ReplaceEventTargetForActor(IProtocol* aActor,
nsIEventTarget* aEventTarget);
nsIEventTarget* GetActorEventTarget();
already_AddRefed<nsIEventTarget> GetActorEventTarget(IProtocol* aActor);
protected:
IProtocol(Side aSide, UniquePtr<ProtocolState> aState)
: mId(0), mSide(aSide), mManager(nullptr), mState(std::move(aState)) {}
friend class IToplevelProtocol;
void SetId(int32_t aId) { mId = aId; }
void ResetManager() { mManager = nullptr; }
// We have separate functions because the accessibility code manually
// calls SetManager.
void SetManager(IProtocol* aManager);
// Sets the manager for the protocol and registers the protocol with
// its manager, setting up channels for the protocol as well. Not
// for use outside of IPDL.
void SetManagerAndRegister(IProtocol* aManager);
void SetManagerAndRegister(IProtocol* aManager, int32_t aId);
static const int32_t kNullActorId = 0;
static const int32_t kFreedActorId = 1;
private:
int32_t mId;
Side mSide;
IProtocol* mManager;
UniquePtr<ProtocolState> mState;
};
typedef IPCMessageStart ProtocolId;
#define IPC_OK() mozilla::ipc::IPCResult::Ok()
#define IPC_FAIL(actor, why) \
mozilla::ipc::IPCResult::Fail(WrapNotNull(actor), __func__, (why))
#define IPC_FAIL_NO_REASON(actor) \
mozilla::ipc::IPCResult::Fail(WrapNotNull(actor), __func__)
/**
* All message deserializer and message handler should return this
* type via above macros. We use a less generic name here to avoid
* conflict with mozilla::Result because we have quite a few using
* namespace mozilla::ipc; in the code base.
*/
class IPCResult {
public:
static IPCResult Ok() { return IPCResult(true); }
static IPCResult Fail(NotNull<IProtocol*> aActor, const char* aWhere,
const char* aWhy = "");
MOZ_IMPLICIT operator bool() const { return mSuccess; }
private:
explicit IPCResult(bool aResult) : mSuccess(aResult) {}
bool mSuccess;
};
template <class PFooSide>
class Endpoint;
/**
* All top-level protocols should inherit this class.
*
* IToplevelProtocol tracks all top-level protocol actors created from
* this protocol actor.
*/
class IToplevelProtocol : public IProtocol {
template <class PFooSide>
friend class Endpoint;
protected:
explicit IToplevelProtocol(const char* aName, ProtocolId aProtoId,
Side aSide);
~IToplevelProtocol();
public:
class ToplevelState final : public ProtocolState {
#ifdef FUZZING
friend class mozilla::ipc::ProtocolFuzzerHelper;
#endif
public:
ToplevelState(const char* aName, IToplevelProtocol* aProtocol, Side aSide);
Shmem::SharedMemory* CreateSharedMemory(size_t,
SharedMemory::SharedMemoryType,
bool, int32_t*) override;
Shmem::SharedMemory* LookupSharedMemory(int32_t) override;
bool IsTrackingSharedMemory(Shmem::SharedMemory*) override;
bool DestroySharedMemory(Shmem&) override;
void DeallocShmems();
bool ShmemCreated(const Message& aMsg);
bool ShmemDestroyed(const Message& aMsg);
int32_t Register(IProtocol*) override;
int32_t RegisterID(IProtocol*, int32_t) override;
IProtocol* Lookup(int32_t) override;
void Unregister(int32_t) override;
nsIEventTarget* GetActorEventTarget() override;
void SetEventTargetForActor(IProtocol* aActor,
nsIEventTarget* aEventTarget) override;
void ReplaceEventTargetForActor(IProtocol* aActor,
nsIEventTarget* aEventTarget) override;
already_AddRefed<nsIEventTarget> GetActorEventTarget(
IProtocol* aActor) override;
virtual already_AddRefed<nsIEventTarget> GetMessageEventTarget(
const Message& aMsg);
const MessageChannel* GetIPCChannel() const override;
MessageChannel* GetIPCChannel() override;
private:
int32_t NextId();
IToplevelProtocol* const mProtocol;
int32_t mLastLocalId;
IDMap<IProtocol*> mActorMap;
IDMap<Shmem::SharedMemory*> mShmemMap;
Mutex mEventTargetMutex;
IDMap<nsCOMPtr<nsIEventTarget>> mEventTargetMap;
MessageChannel mChannel;
};
void SetTransport(UniquePtr<Transport> aTrans) { mTrans = std::move(aTrans); }
Transport* GetTransport() const { return mTrans.get(); }
ProtocolId GetProtocolId() const { return mProtocolId; }
base::ProcessId OtherPid() const final;
void SetOtherProcessId(base::ProcessId aOtherPid);
bool TakeMinidump(nsIFile** aDump, uint32_t* aSequence);
virtual void OnChannelClose() = 0;
virtual void OnChannelError() = 0;
virtual void ProcessingError(Result aError, const char* aMsgName) {}
virtual void OnChannelConnected(int32_t peer_pid) {}
bool Open(mozilla::ipc::Transport* aTransport, base::ProcessId aOtherPid,
MessageLoop* aThread = nullptr,
mozilla::ipc::Side aSide = mozilla::ipc::UnknownSide);
bool Open(MessageChannel* aChannel, MessageLoop* aMessageLoop,
mozilla::ipc::Side aSide = mozilla::ipc::UnknownSide);
bool Open(MessageChannel* aChannel, nsIEventTarget* aEventTarget,
mozilla::ipc::Side aSide = mozilla::ipc::UnknownSide);
bool OpenWithAsyncPid(mozilla::ipc::Transport* aTransport,
MessageLoop* aThread = nullptr,
mozilla::ipc::Side aSide = mozilla::ipc::UnknownSide);
// Open a toplevel actor such that both ends of the actor's channel are on
// the same thread. This method should be called on the thread to perform
// the link.
//
// WARNING: Attempting to send a sync or intr message on the same thread
// will crash.
bool OpenOnSameThread(MessageChannel* aChannel,
mozilla::ipc::Side aSide = mozilla::ipc::UnknownSide);
void Close();
void SetReplyTimeoutMs(int32_t aTimeoutMs);
void DeallocShmems() { DowncastState()->DeallocShmems(); }
bool ShmemCreated(const Message& aMsg) {
return DowncastState()->ShmemCreated(aMsg);
}
bool ShmemDestroyed(const Message& aMsg) {
return DowncastState()->ShmemDestroyed(aMsg);
}
virtual bool ShouldContinueFromReplyTimeout() { return false; }
// WARNING: This function is called with the MessageChannel monitor held.
virtual void IntentionalCrash() { MOZ_CRASH("Intentional IPDL crash"); }
// The code here is only useful for fuzzing. It should not be used for any
// other purpose.
#ifdef DEBUG
// Returns true if we should simulate a timeout.
// WARNING: This is a testing-only function that is called with the
// MessageChannel monitor held. Don't do anything fancy here or we could
// deadlock.
virtual bool ArtificialTimeout() { return false; }
// Returns true if we want to cause the worker thread to sleep with the
// monitor unlocked.
virtual bool NeedArtificialSleep() { return false; }
// This function should be implemented to sleep for some amount of time on
// the worker thread. Will only be called if NeedArtificialSleep() returns
// true.
virtual void ArtificialSleep() {}
#else
bool ArtificialTimeout() { return false; }
bool NeedArtificialSleep() { return false; }
void ArtificialSleep() {}
#endif
virtual void EnteredCxxStack() {}
virtual void ExitedCxxStack() {}
virtual void EnteredCall() {}
virtual void ExitedCall() {}
bool IsOnCxxStack() const;
virtual RacyInterruptPolicy MediateInterruptRace(const MessageInfo& parent,
const MessageInfo& child) {
return RIPChildWins;
}
/**
* Return true if windows messages can be handled while waiting for a reply
* to a sync IPDL message.
*/
virtual bool HandleWindowsMessages(const Message& aMsg) const { return true; }
virtual void OnEnteredSyncSend() {}
virtual void OnExitedSyncSend() {}
virtual void ProcessRemoteNativeEventsInInterruptCall() {}
virtual void OnChannelReceivedMessage(const Message& aMsg) {}
bool IsMainThreadProtocol() const { return mIsMainThreadProtocol; }
void SetIsMainThreadProtocol() { mIsMainThreadProtocol = NS_IsMainThread(); }
already_AddRefed<nsIEventTarget> GetMessageEventTarget(const Message& aMsg) {
return DowncastState()->GetMessageEventTarget(aMsg);
}
protected:
ToplevelState* DowncastState() const {
return static_cast<ToplevelState*>(mState.get());
}
// Override this method in top-level protocols to change the event target
// for a new actor (and its sub-actors).
virtual already_AddRefed<nsIEventTarget> GetConstructedEventTarget(
const Message& aMsg) {
return nullptr;
}
// Override this method in top-level protocols to change the event target
// for specific messages.
virtual already_AddRefed<nsIEventTarget> GetSpecificMessageEventTarget(
const Message& aMsg) {
return nullptr;
}
private:
base::ProcessId OtherPidMaybeInvalid() const;
ProtocolId mProtocolId;
UniquePtr<Transport> mTrans;
base::ProcessId mOtherPid;
bool mIsMainThreadProtocol;
};
class IShmemAllocator {
public:
virtual bool AllocShmem(size_t aSize,
mozilla::ipc::SharedMemory::SharedMemoryType aShmType,
mozilla::ipc::Shmem* aShmem) = 0;
virtual bool AllocUnsafeShmem(
size_t aSize, mozilla::ipc::SharedMemory::SharedMemoryType aShmType,
mozilla::ipc::Shmem* aShmem) = 0;
virtual bool DeallocShmem(mozilla::ipc::Shmem& aShmem) = 0;
};
#define FORWARD_SHMEM_ALLOCATOR_TO(aImplClass) \
virtual bool AllocShmem( \
size_t aSize, mozilla::ipc::SharedMemory::SharedMemoryType aShmType, \
mozilla::ipc::Shmem* aShmem) override { \
return aImplClass::AllocShmem(aSize, aShmType, aShmem); \
} \
virtual bool AllocUnsafeShmem( \
size_t aSize, mozilla::ipc::SharedMemory::SharedMemoryType aShmType, \
mozilla::ipc::Shmem* aShmem) override { \
return aImplClass::AllocUnsafeShmem(aSize, aShmType, aShmem); \
} \
virtual bool DeallocShmem(mozilla::ipc::Shmem& aShmem) override { \
return aImplClass::DeallocShmem(aShmem); \
}
inline bool LoggingEnabled() {
#if defined(DEBUG) || defined(FUZZING)
return !!PR_GetEnv("MOZ_IPC_MESSAGE_LOG");
#else
return false;
#endif
}
inline bool LoggingEnabledFor(const char* aTopLevelProtocol) {
#if defined(DEBUG) || defined(FUZZING)
const char* filter = PR_GetEnv("MOZ_IPC_MESSAGE_LOG");
if (!filter) {
return false;
}
return strcmp(filter, "1") == 0 || strcmp(filter, aTopLevelProtocol) == 0;
#else
return false;
#endif
}
enum class MessageDirection {
eSending,
eReceiving,
};
MOZ_NEVER_INLINE void LogMessageForProtocol(const char* aTopLevelProtocol,
base::ProcessId aOtherPid,
const char* aContextDescription,
uint32_t aMessageId,
MessageDirection aDirection);
MOZ_NEVER_INLINE void ProtocolErrorBreakpoint(const char* aMsg);
// The code generator calls this function for errors which come from the
// methods of protocols. Doing this saves codesize by making the error
// cases significantly smaller.
MOZ_NEVER_INLINE void FatalError(const char* aMsg, bool aIsParent);
// The code generator calls this function for errors which are not
// protocol-specific: errors in generated struct methods or errors in
// transition functions, for instance. Doing this saves codesize by
// by making the error cases significantly smaller.
MOZ_NEVER_INLINE void LogicError(const char* aMsg);
MOZ_NEVER_INLINE void ActorIdReadError(const char* aActorDescription);
MOZ_NEVER_INLINE void BadActorIdError(const char* aActorDescription);
MOZ_NEVER_INLINE void ActorLookupError(const char* aActorDescription);
MOZ_NEVER_INLINE void MismatchedActorTypeError(const char* aActorDescription);
MOZ_NEVER_INLINE void UnionTypeReadError(const char* aUnionName);
MOZ_NEVER_INLINE void ArrayLengthReadError(const char* aElementName);
MOZ_NEVER_INLINE void SentinelReadError(const char* aElementName);
struct PrivateIPDLInterface {};
nsresult Bridge(const PrivateIPDLInterface&, MessageChannel*, base::ProcessId,
MessageChannel*, base::ProcessId, ProtocolId, ProtocolId);
bool Open(const PrivateIPDLInterface&, MessageChannel*, base::ProcessId,
Transport::Mode, ProtocolId, ProtocolId);
bool UnpackChannelOpened(const PrivateIPDLInterface&, const IPC::Message&,
TransportDescriptor*, base::ProcessId*, ProtocolId*);
#if defined(XP_WIN)
// This is a restricted version of Windows' DuplicateHandle() function
// that works inside the sandbox and can send handles but not retrieve
// them. Unlike DuplicateHandle(), it takes a process ID rather than
// a process handle. It returns true on success, false otherwise.
bool DuplicateHandle(HANDLE aSourceHandle, DWORD aTargetProcessId,
HANDLE* aTargetHandle, DWORD aDesiredAccess,
DWORD aOptions);
#endif
/**
* Annotate the crash reporter with the error code from the most recent system
* call. Returns the system error.
*/
void AnnotateSystemError();
enum class LivenessState { Dead, Null, Start = Null };
bool StateTransition(bool aIsDelete, LivenessState* aNext);
enum class ReEntrantDeleteLivenessState {
Dead,
Null,
Dying,
Start = Null,
};
bool ReEntrantDeleteStateTransition(bool aIsDelete, bool aIsDeleteReply,
ReEntrantDeleteLivenessState* aNext);
/**
* An endpoint represents one end of a partially initialized IPDL channel. To
* set up a new top-level protocol:
*
* Endpoint<PFooParent> parentEp;
* Endpoint<PFooChild> childEp;
* nsresult rv;
* rv = PFoo::CreateEndpoints(parentPid, childPid, &parentEp, &childEp);
*
* You're required to pass in parentPid and childPid, which are the pids of the
* processes in which the parent and child endpoints will be used.
*
* Endpoints can be passed in IPDL messages or sent to other threads using
* PostTask. Once an Endpoint has arrived at its destination process and thread,
* you need to create the top-level actor and bind it to the endpoint:
*
* FooParent* parent = new FooParent();
* bool rv1 = parentEp.Bind(parent, processActor);
* bool rv2 = parent->SendBar(...);
*
* (See Bind below for an explanation of processActor.) Once the actor is bound
* to the endpoint, it can send and receive messages.
*/
template <class PFooSide>
class Endpoint {
public:
typedef base::ProcessId ProcessId;
Endpoint()
: mValid(false),
mMode(static_cast<mozilla::ipc::Transport::Mode>(0)),
mMyPid(0),
mOtherPid(0) {}
Endpoint(const PrivateIPDLInterface&, mozilla::ipc::Transport::Mode aMode,
TransportDescriptor aTransport, ProcessId aMyPid,
ProcessId aOtherPid)
: mValid(true),
mMode(aMode),
mTransport(aTransport),
mMyPid(aMyPid),
mOtherPid(aOtherPid) {}
Endpoint(Endpoint&& aOther)
: mValid(aOther.mValid),
mTransport(aOther.mTransport),
mMyPid(aOther.mMyPid),
mOtherPid(aOther.mOtherPid) {
if (aOther.mValid) {
mMode = aOther.mMode;
}
aOther.mValid = false;
}
Endpoint& operator=(Endpoint&& aOther) {
mValid = aOther.mValid;
if (aOther.mValid) {
mMode = aOther.mMode;
}
mTransport = aOther.mTransport;
mMyPid = aOther.mMyPid;
mOtherPid = aOther.mOtherPid;
aOther.mValid = false;
return *this;
}
~Endpoint() {
if (mValid) {
CloseDescriptor(mTransport);
}
}
ProcessId OtherPid() const { return mOtherPid; }
// This method binds aActor to this endpoint. After this call, the actor can
// be used to send and receive messages. The endpoint becomes invalid.
bool Bind(PFooSide* aActor) {
MOZ_RELEASE_ASSERT(mValid);
if (mMyPid != base::GetCurrentProcId()) {
// These pids must match, unless we are recording or replaying, in
// which case the parent process will have supplied the pid for the
// middleman process instead. Fix this here. If we're replaying
// we'll see the pid of the middleman used while recording.
MOZ_RELEASE_ASSERT(recordreplay::IsRecordingOrReplaying());
MOZ_RELEASE_ASSERT(recordreplay::IsReplaying() ||
mMyPid == recordreplay::child::MiddlemanProcessId());
mMyPid = base::GetCurrentProcId();
}
UniquePtr<Transport> t = mozilla::ipc::OpenDescriptor(mTransport, mMode);
if (!t) {
return false;
}
if (!aActor->Open(
t.get(), mOtherPid, XRE_GetIOMessageLoop(),
mMode == Transport::MODE_SERVER ? ParentSide : ChildSide)) {
return false;
}
mValid = false;
aActor->SetTransport(std::move(t));
return true;
}
bool IsValid() const { return mValid; }
private:
friend struct IPC::ParamTraits<Endpoint<PFooSide>>;
Endpoint(const Endpoint&) = delete;
Endpoint& operator=(const Endpoint&) = delete;
bool mValid;
mozilla::ipc::Transport::Mode mMode;
TransportDescriptor mTransport;
ProcessId mMyPid, mOtherPid;
};
#if defined(XP_MACOSX)
void AnnotateCrashReportWithErrno(CrashReporter::Annotation tag, int error);
#else
static inline void AnnotateCrashReportWithErrno(CrashReporter::Annotation tag,
int error) {}
#endif
// This function is used internally to create a pair of Endpoints. See the
// comment above Endpoint for a description of how it might be used.
template <class PFooParent, class PFooChild>
nsresult CreateEndpoints(const PrivateIPDLInterface& aPrivate,
base::ProcessId aParentDestPid,
base::ProcessId aChildDestPid,
Endpoint<PFooParent>* aParentEndpoint,
Endpoint<PFooChild>* aChildEndpoint) {
MOZ_RELEASE_ASSERT(aParentDestPid);
MOZ_RELEASE_ASSERT(aChildDestPid);
TransportDescriptor parentTransport, childTransport;
nsresult rv;
if (NS_FAILED(rv = CreateTransport(aParentDestPid, &parentTransport,
&childTransport))) {
AnnotateCrashReportWithErrno(
CrashReporter::Annotation::IpcCreateEndpointsNsresult, int(rv));
return rv;
}
*aParentEndpoint =
Endpoint<PFooParent>(aPrivate, mozilla::ipc::Transport::MODE_SERVER,
parentTransport, aParentDestPid, aChildDestPid);
*aChildEndpoint =
Endpoint<PFooChild>(aPrivate, mozilla::ipc::Transport::MODE_CLIENT,
childTransport, aChildDestPid, aParentDestPid);
return NS_OK;
}
void TableToArray(const nsTHashtable<nsPtrHashKey<void>>& aTable,
nsTArray<void*>& aArray);
} // namespace ipc
template <typename Protocol>
class ManagedContainer : public nsTHashtable<nsPtrHashKey<Protocol>> {
typedef nsTHashtable<nsPtrHashKey<Protocol>> BaseClass;
public:
// Having the core logic work on void pointers, rather than typed pointers,
// means that we can have one instance of this code out-of-line, rather
// than several hundred instances of this code out-of-lined. (Those
// repeated instances don't necessarily get folded together by the linker
// because they contain member offsets and such that differ between the
// functions.) We do have to pay for it with some eye-bleedingly bad casts,
// though.
void ToArray(nsTArray<Protocol*>& aArray) const {
::mozilla::ipc::TableToArray(
*reinterpret_cast<const nsTHashtable<nsPtrHashKey<void>>*>(
static_cast<const BaseClass*>(this)),
reinterpret_cast<nsTArray<void*>&>(aArray));
}
};
template <typename Protocol>
Protocol* LoneManagedOrNullAsserts(
const ManagedContainer<Protocol>& aManagees) {
if (aManagees.IsEmpty()) {
return nullptr;
}
MOZ_ASSERT(aManagees.Count() == 1);
return aManagees.ConstIter().Get()->GetKey();
}
// appId's are for B2G only currently, where managees.Count() == 1. This is
// not guaranteed currently in Desktop, so for paths used for desktop,
// don't assert there's one managee.
template <typename Protocol>
Protocol* SingleManagedOrNull(const ManagedContainer<Protocol>& aManagees) {
if (aManagees.Count() != 1) {
return nullptr;
}
return aManagees.ConstIter().Get()->GetKey();
}
} // namespace mozilla
namespace IPC {
template <>
struct ParamTraits<mozilla::ipc::ActorHandle> {
typedef mozilla::ipc::ActorHandle paramType;
static void Write(Message* aMsg, const paramType& aParam) {
IPC::WriteParam(aMsg, aParam.mId);
}
static bool Read(const Message* aMsg, PickleIterator* aIter,
paramType* aResult) {
int id;
if (IPC::ReadParam(aMsg, aIter, &id)) {
aResult->mId = id;
return true;
}
return false;
}
static void Log(const paramType& aParam, std::wstring* aLog) {
aLog->append(StringPrintf(L"(%d)", aParam.mId));
}
};
template <class PFooSide>
struct ParamTraits<mozilla::ipc::Endpoint<PFooSide>> {
typedef mozilla::ipc::Endpoint<PFooSide> paramType;
static void Write(Message* aMsg, const paramType& aParam) {
IPC::WriteParam(aMsg, aParam.mValid);
if (!aParam.mValid) {
return;
}
IPC::WriteParam(aMsg, static_cast<uint32_t>(aParam.mMode));
// We duplicate the descriptor so that our own file descriptor remains
// valid after the write. An alternative would be to set
// aParam.mTransport.mValid to false, but that won't work because aParam
// is const.
mozilla::ipc::TransportDescriptor desc =
mozilla::ipc::DuplicateDescriptor(aParam.mTransport);
IPC::WriteParam(aMsg, desc);
IPC::WriteParam(aMsg, aParam.mMyPid);
IPC::WriteParam(aMsg, aParam.mOtherPid);
}
static bool Read(const Message* aMsg, PickleIterator* aIter,
paramType* aResult) {
MOZ_RELEASE_ASSERT(!aResult->mValid);
if (!IPC::ReadParam(aMsg, aIter, &aResult->mValid)) {
return false;
}
if (!aResult->mValid) {
// Object is empty, but read succeeded.
return true;
}
uint32_t mode;
if (!IPC::ReadParam(aMsg, aIter, &mode) ||
!IPC::ReadParam(aMsg, aIter, &aResult->mTransport) ||
!IPC::ReadParam(aMsg, aIter, &aResult->mMyPid) ||
!IPC::ReadParam(aMsg, aIter, &aResult->mOtherPid)) {
return false;
}
aResult->mMode = Channel::Mode(mode);
return true;
}
static void Log(const paramType& aParam, std::wstring* aLog) {
aLog->append(StringPrintf(L"Endpoint"));
}
};
} // namespace IPC
#endif // mozilla_ipc_ProtocolUtils_h