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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/bind.h"
#include "base/compiler_specific.h"
#include "base/location.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "ipc/ipc_channel_proxy.h"
#include "ipc/ipc_logging.h"
#include "ipc/ipc_message_utils.h"
namespace IPC {
// This helper ensures the message is deleted if the task is deleted without
// having been run.
class SendCallbackHelper
: public base::RefCountedThreadSafe<SendCallbackHelper> {
public:
SendCallbackHelper(ChannelProxy::Context* context, Message* message)
: context_(context),
message_(message) {
}
void Send() {
context_->OnSendMessage(message_.release());
}
private:
scoped_refptr<ChannelProxy::Context> context_;
scoped_ptr<Message> message_;
DISALLOW_COPY_AND_ASSIGN(SendCallbackHelper);
};
//------------------------------------------------------------------------------
ChannelProxy::MessageFilter::MessageFilter() {}
ChannelProxy::MessageFilter::~MessageFilter() {}
void ChannelProxy::MessageFilter::OnFilterAdded(Channel* channel) {}
void ChannelProxy::MessageFilter::OnFilterRemoved() {}
void ChannelProxy::MessageFilter::OnChannelConnected(int32 peer_pid) {}
void ChannelProxy::MessageFilter::OnChannelError() {}
void ChannelProxy::MessageFilter::OnChannelClosing() {}
bool ChannelProxy::MessageFilter::OnMessageReceived(const Message& message) {
return false;
}
void ChannelProxy::MessageFilter::OnDestruct() const {
delete this;
}
//------------------------------------------------------------------------------
ChannelProxy::Context::Context(Channel::Listener* listener,
base::MessageLoopProxy* ipc_message_loop)
: listener_message_loop_(base::MessageLoopProxy::current()),
listener_(listener),
ipc_message_loop_(ipc_message_loop),
peer_pid_(0),
channel_connected_called_(false) {
}
ChannelProxy::Context::~Context() {
}
void ChannelProxy::Context::CreateChannel(const IPC::ChannelHandle& handle,
const Channel::Mode& mode) {
DCHECK(channel_.get() == NULL);
channel_id_ = handle.name;
channel_.reset(new Channel(handle, mode, this));
}
bool ChannelProxy::Context::TryFilters(const Message& message) {
#ifdef IPC_MESSAGE_LOG_ENABLED
Logging* logger = Logging::GetInstance();
if (logger->Enabled())
logger->OnPreDispatchMessage(message);
#endif
for (size_t i = 0; i < filters_.size(); ++i) {
if (filters_[i]->OnMessageReceived(message)) {
#ifdef IPC_MESSAGE_LOG_ENABLED
if (logger->Enabled())
logger->OnPostDispatchMessage(message, channel_id_);
#endif
return true;
}
}
return false;
}
// Called on the IPC::Channel thread
bool ChannelProxy::Context::OnMessageReceived(const Message& message) {
// First give a chance to the filters to process this message.
if (!TryFilters(message))
OnMessageReceivedNoFilter(message);
return true;
}
// Called on the IPC::Channel thread
bool ChannelProxy::Context::OnMessageReceivedNoFilter(const Message& message) {
// NOTE: This code relies on the listener's message loop not going away while
// this thread is active. That should be a reasonable assumption, but it
// feels risky. We may want to invent some more indirect way of referring to
// a MessageLoop if this becomes a problem.
listener_message_loop_->PostTask(
FROM_HERE, base::Bind(&Context::OnDispatchMessage, this, message));
return true;
}
// Called on the IPC::Channel thread
void ChannelProxy::Context::OnChannelConnected(int32 peer_pid) {
// Add any pending filters. This avoids a race condition where someone
// creates a ChannelProxy, calls AddFilter, and then right after starts the
// peer process. The IO thread could receive a message before the task to add
// the filter is run on the IO thread.
OnAddFilter();
peer_pid_ = peer_pid;
for (size_t i = 0; i < filters_.size(); ++i)
filters_[i]->OnChannelConnected(peer_pid);
// See above comment about using listener_message_loop_ here.
listener_message_loop_->PostTask(
FROM_HERE, base::Bind(&Context::OnDispatchConnected, this));
}
// Called on the IPC::Channel thread
void ChannelProxy::Context::OnChannelError() {
for (size_t i = 0; i < filters_.size(); ++i)
filters_[i]->OnChannelError();
// See above comment about using listener_message_loop_ here.
listener_message_loop_->PostTask(
FROM_HERE, base::Bind(&Context::OnDispatchError, this));
}
// Called on the IPC::Channel thread
void ChannelProxy::Context::OnChannelOpened() {
DCHECK(channel_ != NULL);
// Assume a reference to ourselves on behalf of this thread. This reference
// will be released when we are closed.
AddRef();
if (!channel_->Connect()) {
OnChannelError();
return;
}
for (size_t i = 0; i < filters_.size(); ++i)
filters_[i]->OnFilterAdded(channel_.get());
}
// Called on the IPC::Channel thread
void ChannelProxy::Context::OnChannelClosed() {
// It's okay for IPC::ChannelProxy::Close to be called more than once, which
// would result in this branch being taken.
if (!channel_.get())
return;
for (size_t i = 0; i < filters_.size(); ++i) {
filters_[i]->OnChannelClosing();
filters_[i]->OnFilterRemoved();
}
// We don't need the filters anymore.
filters_.clear();
channel_.reset();
// Balance with the reference taken during startup. This may result in
// self-destruction.
Release();
}
// Called on the IPC::Channel thread
void ChannelProxy::Context::OnSendMessage(Message* message) {
if (!channel_.get()) {
delete message;
OnChannelClosed();
return;
}
if (!channel_->Send(message))
OnChannelError();
}
// Called on the IPC::Channel thread
void ChannelProxy::Context::OnAddFilter() {
std::vector<scoped_refptr<MessageFilter> > new_filters;
{
base::AutoLock auto_lock(pending_filters_lock_);
new_filters.swap(pending_filters_);
}
for (size_t i = 0; i < new_filters.size(); ++i) {
filters_.push_back(new_filters[i]);
// If the channel has already been created, then we need to send this
// message so that the filter gets access to the Channel.
if (channel_.get())
new_filters[i]->OnFilterAdded(channel_.get());
// Ditto for if the channel has been connected.
if (peer_pid_)
new_filters[i]->OnChannelConnected(peer_pid_);
}
}
// Called on the IPC::Channel thread
void ChannelProxy::Context::OnRemoveFilter(MessageFilter* filter) {
for (size_t i = 0; i < filters_.size(); ++i) {
if (filters_[i].get() == filter) {
filter->OnFilterRemoved();
filters_.erase(filters_.begin() + i);
return;
}
}
NOTREACHED() << "filter to be removed not found";
}
// Called on the listener's thread
void ChannelProxy::Context::AddFilter(MessageFilter* filter) {
base::AutoLock auto_lock(pending_filters_lock_);
pending_filters_.push_back(make_scoped_refptr(filter));
ipc_message_loop_->PostTask(
FROM_HERE, base::Bind(&Context::OnAddFilter, this));
}
// Called on the listener's thread
void ChannelProxy::Context::OnDispatchMessage(const Message& message) {
if (!listener_)
return;
OnDispatchConnected();
#ifdef IPC_MESSAGE_LOG_ENABLED
Logging* logger = Logging::GetInstance();
if (message.type() == IPC_LOGGING_ID) {
logger->OnReceivedLoggingMessage(message);
return;
}
if (logger->Enabled())
logger->OnPreDispatchMessage(message);
#endif
listener_->OnMessageReceived(message);
#ifdef IPC_MESSAGE_LOG_ENABLED
if (logger->Enabled())
logger->OnPostDispatchMessage(message, channel_id_);
#endif
}
// Called on the listener's thread
void ChannelProxy::Context::OnDispatchConnected() {
if (channel_connected_called_)
return;
channel_connected_called_ = true;
if (listener_)
listener_->OnChannelConnected(peer_pid_);
}
// Called on the listener's thread
void ChannelProxy::Context::OnDispatchError() {
if (listener_)
listener_->OnChannelError();
}
//-----------------------------------------------------------------------------
ChannelProxy::ChannelProxy(const IPC::ChannelHandle& channel_handle,
Channel::Mode mode,
Channel::Listener* listener,
base::MessageLoopProxy* ipc_thread)
: context_(new Context(listener, ipc_thread)),
outgoing_message_filter_(NULL),
did_init_(false) {
Init(channel_handle, mode, true);
}
ChannelProxy::ChannelProxy(Context* context)
: context_(context),
outgoing_message_filter_(NULL),
did_init_(false) {
}
ChannelProxy::~ChannelProxy() {
Close();
}
void ChannelProxy::Init(const IPC::ChannelHandle& channel_handle,
Channel::Mode mode,
bool create_pipe_now) {
DCHECK(!did_init_);
#if defined(OS_POSIX)
// When we are creating a server on POSIX, we need its file descriptor
// to be created immediately so that it can be accessed and passed
// to other processes. Forcing it to be created immediately avoids
// race conditions that may otherwise arise.
if (mode & Channel::MODE_SERVER_FLAG) {
create_pipe_now = true;
}
#endif // defined(OS_POSIX)
if (create_pipe_now) {
// Create the channel immediately. This effectively sets up the
// low-level pipe so that the client can connect. Without creating
// the pipe immediately, it is possible for a listener to attempt
// to connect and get an error since the pipe doesn't exist yet.
context_->CreateChannel(channel_handle, mode);
} else {
context_->ipc_message_loop()->PostTask(
FROM_HERE, base::Bind(&Context::CreateChannel, context_.get(),
channel_handle, mode));
}
// complete initialization on the background thread
context_->ipc_message_loop()->PostTask(
FROM_HERE, base::Bind(&Context::OnChannelOpened, context_.get()));
did_init_ = true;
}
void ChannelProxy::Close() {
// Clear the backpointer to the listener so that any pending calls to
// Context::OnDispatchMessage or OnDispatchError will be ignored. It is
// possible that the channel could be closed while it is receiving messages!
context_->Clear();
if (context_->ipc_message_loop()) {
context_->ipc_message_loop()->PostTask(
FROM_HERE, base::Bind(&Context::OnChannelClosed, context_.get()));
}
}
bool ChannelProxy::Send(Message* message) {
DCHECK(did_init_);
if (outgoing_message_filter())
message = outgoing_message_filter()->Rewrite(message);
#ifdef IPC_MESSAGE_LOG_ENABLED
Logging::GetInstance()->OnSendMessage(message, context_->channel_id());
#endif
context_->ipc_message_loop()->PostTask(
FROM_HERE,
base::Bind(&SendCallbackHelper::Send,
new SendCallbackHelper(context_.get(), message)));
return true;
}
void ChannelProxy::AddFilter(MessageFilter* filter) {
context_->AddFilter(filter);
}
void ChannelProxy::RemoveFilter(MessageFilter* filter) {
context_->ipc_message_loop()->PostTask(
FROM_HERE, base::Bind(&Context::OnRemoveFilter, context_.get(),
make_scoped_refptr(filter)));
}
void ChannelProxy::ClearIPCMessageLoop() {
context()->ClearIPCMessageLoop();
}
#if defined(OS_POSIX) && !defined(OS_NACL)
// See the TODO regarding lazy initialization of the channel in
// ChannelProxy::Init().
int ChannelProxy::GetClientFileDescriptor() {
Channel* channel = context_.get()->channel_.get();
// Channel must have been created first.
DCHECK(channel) << context_.get()->channel_id_;
return channel->GetClientFileDescriptor();
}
int ChannelProxy::TakeClientFileDescriptor() {
Channel* channel = context_.get()->channel_.get();
// Channel must have been created first.
DCHECK(channel) << context_.get()->channel_id_;
return channel->TakeClientFileDescriptor();
}
bool ChannelProxy::GetClientEuid(uid_t* client_euid) const {
Channel* channel = context_.get()->channel_.get();
// Channel must have been created first.
DCHECK(channel) << context_.get()->channel_id_;
return channel->GetClientEuid(client_euid);
}
#endif
//-----------------------------------------------------------------------------
} // namespace IPC
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