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android / platform / external / libmojo / ca6c42abc66e142da1036f0061976d671862c457 / . / mojo / edk / system / node_controller.cc
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// Copyright 2016 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 "mojo/edk/system/node_controller.h"
#include <algorithm>
#include <limits>
#include "base/bind.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram_macros.h"
#include "base/process/process_handle.h"
#include "base/rand_util.h"
#include "base/time/time.h"
#include "base/timer/elapsed_timer.h"
#include "mojo/edk/embedder/embedder_internal.h"
#include "mojo/edk/embedder/named_platform_channel_pair.h"
#include "mojo/edk/embedder/named_platform_handle.h"
#include "mojo/edk/embedder/platform_channel_pair.h"
#include "mojo/edk/system/broker.h"
#include "mojo/edk/system/broker_host.h"
#include "mojo/edk/system/core.h"
#include "mojo/edk/system/ports_message.h"
#include "mojo/edk/system/request_context.h"
#if defined(OS_MACOSX) && !defined(OS_IOS)
#include "mojo/edk/system/mach_port_relay.h"
#endif
#if !defined(OS_NACL)
#include "crypto/random.h"
#endif
namespace mojo {
namespace edk {
namespace {
#if defined(OS_NACL)
template <typename T>
void GenerateRandomName(T* out) { base::RandBytes(out, sizeof(T)); }
#else
template <typename T>
void GenerateRandomName(T* out) { crypto::RandBytes(out, sizeof(T)); }
#endif
ports::NodeName GetRandomNodeName() {
ports::NodeName name;
GenerateRandomName(&name);
return name;
}
void RecordPeerCount(size_t count) {
DCHECK_LE(count, static_cast<size_t>(std::numeric_limits<int32_t>::max()));
// 8k is the maximum number of file descriptors allowed in Chrome.
UMA_HISTOGRAM_CUSTOM_COUNTS("Mojo.System.Node.ConnectedPeers",
static_cast<int32_t>(count),
1 /* min */,
8000 /* max */,
50 /* bucket count */);
}
void RecordPendingChildCount(size_t count) {
DCHECK_LE(count, static_cast<size_t>(std::numeric_limits<int32_t>::max()));
// 8k is the maximum number of file descriptors allowed in Chrome.
UMA_HISTOGRAM_CUSTOM_COUNTS("Mojo.System.Node.PendingChildren",
static_cast<int32_t>(count),
1 /* min */,
8000 /* max */,
50 /* bucket count */);
}
bool ParsePortsMessage(Channel::Message* message,
void** data,
size_t* num_data_bytes,
size_t* num_header_bytes,
size_t* num_payload_bytes,
size_t* num_ports_bytes) {
DCHECK(data && num_data_bytes && num_header_bytes && num_payload_bytes &&
num_ports_bytes);
NodeChannel::GetPortsMessageData(message, data, num_data_bytes);
if (!*num_data_bytes)
return false;
if (!ports::Message::Parse(*data, *num_data_bytes, num_header_bytes,
num_payload_bytes, num_ports_bytes)) {
return false;
}
return true;
}
// Used by NodeController to watch for shutdown. Since no IO can happen once
// the IO thread is killed, the NodeController can cleanly drop all its peers
// at that time.
class ThreadDestructionObserver :
public base::MessageLoop::DestructionObserver {
public:
static void Create(scoped_refptr<base::TaskRunner> task_runner,
const base::Closure& callback) {
if (task_runner->RunsTasksOnCurrentThread()) {
// Owns itself.
new ThreadDestructionObserver(callback);
} else {
task_runner->PostTask(FROM_HERE,
base::Bind(&Create, task_runner, callback));
}
}
private:
explicit ThreadDestructionObserver(const base::Closure& callback)
: callback_(callback) {
base::MessageLoop::current()->AddDestructionObserver(this);
}
~ThreadDestructionObserver() override {
base::MessageLoop::current()->RemoveDestructionObserver(this);
}
// base::MessageLoop::DestructionObserver:
void WillDestroyCurrentMessageLoop() override {
callback_.Run();
delete this;
}
const base::Closure callback_;
DISALLOW_COPY_AND_ASSIGN(ThreadDestructionObserver);
};
} // namespace
NodeController::~NodeController() {}
NodeController::NodeController(Core* core)
: core_(core),
name_(GetRandomNodeName()),
node_(new ports::Node(name_, this)) {
DVLOG(1) << "Initializing node " << name_;
}
#if defined(OS_MACOSX) && !defined(OS_IOS)
void NodeController::CreateMachPortRelay(
base::PortProvider* port_provider) {
base::AutoLock lock(mach_port_relay_lock_);
DCHECK(!mach_port_relay_);
mach_port_relay_.reset(new MachPortRelay(port_provider));
}
#endif
void NodeController::SetIOTaskRunner(
scoped_refptr<base::TaskRunner> task_runner) {
io_task_runner_ = task_runner;
ThreadDestructionObserver::Create(
io_task_runner_,
base::Bind(&NodeController::DropAllPeers, base::Unretained(this)));
}
void NodeController::ConnectToChild(
base::ProcessHandle process_handle,
ConnectionParams connection_params,
const std::string& child_token,
const ProcessErrorCallback& process_error_callback) {
// Generate the temporary remote node name here so that it can be associated
// with the embedder's child_token. If an error occurs in the child process
// after it is launched, but before any reserved ports are connected, this can
// be used to clean up any dangling ports.
ports::NodeName node_name;
GenerateRandomName(&node_name);
{
base::AutoLock lock(reserved_ports_lock_);
bool inserted = pending_child_tokens_.insert(
std::make_pair(node_name, child_token)).second;
DCHECK(inserted);
}
#if defined(OS_WIN)
// On Windows, we need to duplicate the process handle because we have no
// control over its lifetime and it may become invalid by the time the posted
// task runs.
HANDLE dup_handle = INVALID_HANDLE_VALUE;
BOOL ok = ::DuplicateHandle(
base::GetCurrentProcessHandle(), process_handle,
base::GetCurrentProcessHandle(), &dup_handle,
0, FALSE, DUPLICATE_SAME_ACCESS);
DPCHECK(ok);
process_handle = dup_handle;
#endif
io_task_runner_->PostTask(
FROM_HERE, base::Bind(&NodeController::ConnectToChildOnIOThread,
base::Unretained(this), process_handle,
base::Passed(&connection_params), node_name,
process_error_callback));
}
void NodeController::CloseChildPorts(const std::string& child_token) {
std::vector<ports::PortRef> ports_to_close;
{
std::vector<std::string> port_tokens;
base::AutoLock lock(reserved_ports_lock_);
for (const auto& port : reserved_ports_) {
if (port.second.child_token == child_token) {
DVLOG(1) << "Closing reserved port " << port.second.port.name();
ports_to_close.push_back(port.second.port);
port_tokens.push_back(port.first);
}
}
for (const auto& token : port_tokens)
reserved_ports_.erase(token);
}
for (const auto& port : ports_to_close)
node_->ClosePort(port);
// Ensure local port closure messages are processed.
AcceptIncomingMessages();
}
void NodeController::ClosePeerConnection(const std::string& peer_token) {
io_task_runner_->PostTask(
FROM_HERE, base::Bind(&NodeController::ClosePeerConnectionOnIOThread,
base::Unretained(this), peer_token));
}
void NodeController::ConnectToParent(ConnectionParams connection_params) {
#if !defined(OS_MACOSX) && !defined(OS_NACL_SFI)
// Use the bootstrap channel for the broker and receive the node's channel
// synchronously as the first message from the broker.
base::ElapsedTimer timer;
broker_.reset(new Broker(connection_params.TakeChannelHandle()));
ScopedPlatformHandle platform_handle = broker_->GetParentPlatformHandle();
UMA_HISTOGRAM_TIMES("Mojo.System.GetParentPlatformHandleSyncTime",
timer.Elapsed());
if (!platform_handle.is_valid()) {
// Most likely the browser side of the channel has already been closed and
// the broker was unable to negotiate a NodeChannel pipe. In this case we
// can cancel parent connection.
DVLOG(1) << "Cannot connect to invalid parent channel.";
CancelPendingPortMerges();
return;
}
connection_params = ConnectionParams(std::move(platform_handle));
#endif
io_task_runner_->PostTask(
FROM_HERE,
base::Bind(&NodeController::ConnectToParentOnIOThread,
base::Unretained(this), base::Passed(&connection_params)));
}
void NodeController::ConnectToPeer(ConnectionParams connection_params,
const ports::PortRef& port,
const std::string& peer_token) {
ports::NodeName node_name;
GenerateRandomName(&node_name);
io_task_runner_->PostTask(
FROM_HERE,
base::Bind(&NodeController::ConnectToPeerOnIOThread,
base::Unretained(this), base::Passed(&connection_params),
node_name, port, peer_token));
}
void NodeController::SetPortObserver(const ports::PortRef& port,
scoped_refptr<PortObserver> observer) {
node_->SetUserData(port, std::move(observer));
}
void NodeController::ClosePort(const ports::PortRef& port) {
SetPortObserver(port, nullptr);
int rv = node_->ClosePort(port);
DCHECK_EQ(rv, ports::OK) << " Failed to close port: " << port.name();
AcceptIncomingMessages();
}
int NodeController::SendMessage(const ports::PortRef& port,
std::unique_ptr<PortsMessage> message) {
ports::ScopedMessage ports_message(message.release());
int rv = node_->SendMessage(port, std::move(ports_message));
AcceptIncomingMessages();
return rv;
}
void NodeController::ReservePort(const std::string& token,
const ports::PortRef& port,
const std::string& child_token) {
DVLOG(2) << "Reserving port " << port.name() << "@" << name_ << " for token "
<< token;
base::AutoLock lock(reserved_ports_lock_);
auto result = reserved_ports_.insert(
std::make_pair(token, ReservedPort{port, child_token}));
DCHECK(result.second);
}
void NodeController::MergePortIntoParent(const std::string& token,
const ports::PortRef& port) {
bool was_merged = false;
{
// This request may be coming from within the process that reserved the
// "parent" side (e.g. for Chrome single-process mode), so if this token is
// reserved locally, merge locally instead.
base::AutoLock lock(reserved_ports_lock_);
auto it = reserved_ports_.find(token);
if (it != reserved_ports_.end()) {
node_->MergePorts(port, name_, it->second.port.name());
reserved_ports_.erase(it);
was_merged = true;
}
}
if (was_merged) {
AcceptIncomingMessages();
return;
}
scoped_refptr<NodeChannel> parent;
bool reject_merge = false;
{
// Hold |pending_port_merges_lock_| while getting |parent|. Otherwise,
// there is a race where the parent can be set, and |pending_port_merges_|
// be processed between retrieving |parent| and adding the merge to
// |pending_port_merges_|.
base::AutoLock lock(pending_port_merges_lock_);
parent = GetParentChannel();
if (reject_pending_merges_) {
reject_merge = true;
} else if (!parent) {
pending_port_merges_.push_back(std::make_pair(token, port));
return;
}
}
if (reject_merge) {
node_->ClosePort(port);
DVLOG(2) << "Rejecting port merge for token " << token
<< " due to closed parent channel.";
AcceptIncomingMessages();
return;
}
parent->RequestPortMerge(port.name(), token);
}
int NodeController::MergeLocalPorts(const ports::PortRef& port0,
const ports::PortRef& port1) {
int rv = node_->MergeLocalPorts(port0, port1);
AcceptIncomingMessages();
return rv;
}
scoped_refptr<PlatformSharedBuffer> NodeController::CreateSharedBuffer(
size_t num_bytes) {
#if !defined(OS_MACOSX) && !defined(OS_NACL_SFI)
// Shared buffer creation failure is fatal, so always use the broker when we
// have one. This does mean that a non-root process that has children will use
// the broker for shared buffer creation even though that process is
// privileged.
if (broker_) {
return broker_->GetSharedBuffer(num_bytes);
}
#endif
return PlatformSharedBuffer::Create(num_bytes);
}
void NodeController::RequestShutdown(const base::Closure& callback) {
{
base::AutoLock lock(shutdown_lock_);
shutdown_callback_ = callback;
shutdown_callback_flag_.Set(true);
}
AttemptShutdownIfRequested();
}
void NodeController::NotifyBadMessageFrom(const ports::NodeName& source_node,
const std::string& error) {
scoped_refptr<NodeChannel> peer = GetPeerChannel(source_node);
if (peer)
peer->NotifyBadMessage(error);
}
void NodeController::ConnectToChildOnIOThread(
base::ProcessHandle process_handle,
ConnectionParams connection_params,
ports::NodeName token,
const ProcessErrorCallback& process_error_callback) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
#if !defined(OS_MACOSX) && !defined(OS_NACL)
PlatformChannelPair node_channel;
ScopedPlatformHandle server_handle = node_channel.PassServerHandle();
// BrokerHost owns itself.
BrokerHost* broker_host =
new BrokerHost(process_handle, connection_params.TakeChannelHandle());
bool channel_ok = broker_host->SendChannel(node_channel.PassClientHandle());
#if defined(OS_WIN)
if (!channel_ok) {
// On Windows the above operation may fail if the channel is crossing a
// session boundary. In that case we fall back to a named pipe.
NamedPlatformChannelPair named_channel;
server_handle = named_channel.PassServerHandle();
broker_host->SendNamedChannel(named_channel.handle().name);
}
#else
CHECK(channel_ok);
#endif // defined(OS_WIN)
scoped_refptr<NodeChannel> channel =
NodeChannel::Create(this, ConnectionParams(std::move(server_handle)),
io_task_runner_, process_error_callback);
#else // !defined(OS_MACOSX) && !defined(OS_NACL)
scoped_refptr<NodeChannel> channel =
NodeChannel::Create(this, std::move(connection_params), io_task_runner_,
process_error_callback);
#endif // !defined(OS_MACOSX) && !defined(OS_NACL)
// We set up the child channel with a temporary name so it can be identified
// as a pending child if it writes any messages to the channel. We may start
// receiving messages from it (though we shouldn't) as soon as Start() is
// called below.
pending_children_.insert(std::make_pair(token, channel));
RecordPendingChildCount(pending_children_.size());
channel->SetRemoteNodeName(token);
channel->SetRemoteProcessHandle(process_handle);
channel->Start();
channel->AcceptChild(name_, token);
}
void NodeController::ConnectToParentOnIOThread(
ConnectionParams connection_params) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
{
base::AutoLock lock(parent_lock_);
DCHECK(parent_name_ == ports::kInvalidNodeName);
// At this point we don't know the parent's name, so we can't yet insert it
// into our |peers_| map. That will happen as soon as we receive an
// AcceptChild message from them.
bootstrap_parent_channel_ =
NodeChannel::Create(this, std::move(connection_params), io_task_runner_,
ProcessErrorCallback());
// Prevent the parent pipe handle from being closed on shutdown. Pipe
// closure is used by the parent to detect the child process has exited.
// Relying on message pipes to be closed is not enough because the parent
// may see the message pipe closure before the child is dead, causing the
// child process to be unexpectedly SIGKILL'd.
bootstrap_parent_channel_->LeakHandleOnShutdown();
}
bootstrap_parent_channel_->Start();
}
void NodeController::ConnectToPeerOnIOThread(ConnectionParams connection_params,
ports::NodeName token,
ports::PortRef port,
const std::string& peer_token) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
scoped_refptr<NodeChannel> channel = NodeChannel::Create(
this, std::move(connection_params), io_task_runner_, {});
peer_connections_.insert(
{token, PeerConnection{channel, port, peer_token}});
peers_by_token_.insert({peer_token, token});
channel->SetRemoteNodeName(token);
channel->Start();
channel->AcceptPeer(name_, token, port.name());
}
void NodeController::ClosePeerConnectionOnIOThread(
const std::string& peer_token) {
RequestContext request_context(RequestContext::Source::SYSTEM);
auto peer = peers_by_token_.find(peer_token);
// The connection may already be closed.
if (peer == peers_by_token_.end())
return;
// |peer| may be removed so make a copy of |name|.
ports::NodeName name = peer->second;
DropPeer(name, nullptr);
}
scoped_refptr<NodeChannel> NodeController::GetPeerChannel(
const ports::NodeName& name) {
base::AutoLock lock(peers_lock_);
auto it = peers_.find(name);
if (it == peers_.end())
return nullptr;
return it->second;
}
scoped_refptr<NodeChannel> NodeController::GetParentChannel() {
ports::NodeName parent_name;
{
base::AutoLock lock(parent_lock_);
parent_name = parent_name_;
}
return GetPeerChannel(parent_name);
}
scoped_refptr<NodeChannel> NodeController::GetBrokerChannel() {
ports::NodeName broker_name;
{
base::AutoLock lock(broker_lock_);
broker_name = broker_name_;
}
return GetPeerChannel(broker_name);
}
void NodeController::AddPeer(const ports::NodeName& name,
scoped_refptr<NodeChannel> channel,
bool start_channel) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
DCHECK(name != ports::kInvalidNodeName);
DCHECK(channel);
channel->SetRemoteNodeName(name);
OutgoingMessageQueue pending_messages;
{
base::AutoLock lock(peers_lock_);
if (peers_.find(name) != peers_.end()) {
// This can happen normally if two nodes race to be introduced to each
// other. The losing pipe will be silently closed and introduction should
// not be affected.
DVLOG(1) << "Ignoring duplicate peer name " << name;
return;
}
auto result = peers_.insert(std::make_pair(name, channel));
DCHECK(result.second);
DVLOG(2) << "Accepting new peer " << name << " on node " << name_;
RecordPeerCount(peers_.size());
auto it = pending_peer_messages_.find(name);
if (it != pending_peer_messages_.end()) {
std::swap(pending_messages, it->second);
pending_peer_messages_.erase(it);
}
}
if (start_channel)
channel->Start();
// Flush any queued message we need to deliver to this node.
while (!pending_messages.empty()) {
channel->PortsMessage(std::move(pending_messages.front()));
pending_messages.pop();
}
}
void NodeController::DropPeer(const ports::NodeName& name,
NodeChannel* channel) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
{
base::AutoLock lock(peers_lock_);
auto it = peers_.find(name);
if (it != peers_.end()) {
ports::NodeName peer = it->first;
peers_.erase(it);
DVLOG(1) << "Dropped peer " << peer;
}
pending_peer_messages_.erase(name);
pending_children_.erase(name);
RecordPeerCount(peers_.size());
RecordPendingChildCount(pending_children_.size());
}
std::vector<ports::PortRef> ports_to_close;
{
// Clean up any reserved ports.
base::AutoLock lock(reserved_ports_lock_);
auto it = pending_child_tokens_.find(name);
if (it != pending_child_tokens_.end()) {
const std::string& child_token = it->second;
std::vector<std::string> port_tokens;
for (const auto& port : reserved_ports_) {
if (port.second.child_token == child_token) {
DVLOG(1) << "Closing reserved port: " << port.second.port.name();
ports_to_close.push_back(port.second.port);
port_tokens.push_back(port.first);
}
}
// We have to erase reserved ports in a two-step manner because the usual
// manner of using the returned iterator from map::erase isn't technically
// valid in C++11 (although it is in C++14).
for (const auto& token : port_tokens)
reserved_ports_.erase(token);
pending_child_tokens_.erase(it);
}
}
bool is_parent;
{
base::AutoLock lock(parent_lock_);
is_parent = (name == parent_name_ || channel == bootstrap_parent_channel_);
}
// If the error comes from the parent channel, we also need to cancel any
// port merge requests, so that errors can be propagated to the message
// pipes.
if (is_parent)
CancelPendingPortMerges();
auto peer = peer_connections_.find(name);
if (peer != peer_connections_.end()) {
peers_by_token_.erase(peer->second.peer_token);
ports_to_close.push_back(peer->second.local_port);
peer_connections_.erase(peer);
}
for (const auto& port : ports_to_close)
node_->ClosePort(port);
node_->LostConnectionToNode(name);
AcceptIncomingMessages();
}
void NodeController::SendPeerMessage(const ports::NodeName& name,
ports::ScopedMessage message) {
Channel::MessagePtr channel_message =
static_cast<PortsMessage*>(message.get())->TakeChannelMessage();
scoped_refptr<NodeChannel> peer = GetPeerChannel(name);
#if defined(OS_WIN)
if (channel_message->has_handles()) {
// If we're sending a message with handles we aren't the destination
// node's parent or broker (i.e. we don't know its process handle), ask
// the broker to relay for us.
scoped_refptr<NodeChannel> broker = GetBrokerChannel();
if (!peer || !peer->HasRemoteProcessHandle()) {
if (broker) {
broker->RelayPortsMessage(name, std::move(channel_message));
} else {
base::AutoLock lock(broker_lock_);
pending_relay_messages_[name].emplace(std::move(channel_message));
}
return;
}
}
#elif defined(OS_MACOSX) && !defined(OS_IOS)
if (channel_message->has_mach_ports()) {
// Messages containing Mach ports are always routed through the broker, even
// if the broker process is the intended recipient.
bool use_broker = false;
{
base::AutoLock lock(parent_lock_);
use_broker = (bootstrap_parent_channel_ ||
parent_name_ != ports::kInvalidNodeName);
}
if (use_broker) {
scoped_refptr<NodeChannel> broker = GetBrokerChannel();
if (broker) {
broker->RelayPortsMessage(name, std::move(channel_message));
} else {
base::AutoLock lock(broker_lock_);
pending_relay_messages_[name].emplace(std::move(channel_message));
}
return;
}
}
#endif // defined(OS_WIN)
if (peer) {
peer->PortsMessage(std::move(channel_message));
return;
}
// If we don't know who the peer is and we are the broker, we can only assume
// the peer is invalid, i.e., it's either a junk name or has already been
// disconnected.
scoped_refptr<NodeChannel> broker = GetBrokerChannel();
if (!broker) {
DVLOG(1) << "Dropping message for unknown peer: " << name;
return;
}
// If we aren't the broker, assume we just need to be introduced and queue
// until that can be either confirmed or denied by the broker.
bool needs_introduction = false;
{
base::AutoLock lock(peers_lock_);
auto& queue = pending_peer_messages_[name];
needs_introduction = queue.empty();
queue.emplace(std::move(channel_message));
}
if (needs_introduction)
broker->RequestIntroduction(name);
}
void NodeController::AcceptIncomingMessages() {
// This is an impactically large value which should never be reached in
// practice. See the CHECK below for usage.
constexpr size_t kMaxAcceptedMessages = 1000000;
size_t num_messages_accepted = 0;
while (incoming_messages_flag_) {
// TODO: We may need to be more careful to avoid starving the rest of the
// thread here. Revisit this if it turns out to be a problem. One
// alternative would be to schedule a task to continue pumping messages
// after flushing once.
messages_lock_.Acquire();
if (incoming_messages_.empty()) {
messages_lock_.Release();
break;
}
// libstdc++'s deque creates an internal buffer on construction, even when
// the size is 0. So avoid creating it until it is necessary.
std::queue<ports::ScopedMessage> messages;
std::swap(messages, incoming_messages_);
incoming_messages_flag_.Set(false);
messages_lock_.Release();
num_messages_accepted += messages.size();
while (!messages.empty()) {
node_->AcceptMessage(std::move(messages.front()));
messages.pop();
}
// This is effectively a safeguard against potential bugs which might lead
// to runaway message cycles. If any such cycles arise, we'll start seeing
// crash reports from this location.
CHECK_LE(num_messages_accepted, kMaxAcceptedMessages);
}
if (num_messages_accepted >= 4) {
// Note: We avoid logging this histogram for the vast majority of cases.
// See https://crbug.com/685763 for more context.
UMA_HISTOGRAM_CUSTOM_COUNTS("Mojo.System.MessagesAcceptedPerEvent",
static_cast<int32_t>(num_messages_accepted),
1 /* min */,
500 /* max */,
50 /* bucket count */);
}
AttemptShutdownIfRequested();
}
void NodeController::ProcessIncomingMessages() {
RequestContext request_context(RequestContext::Source::SYSTEM);
{
base::AutoLock lock(messages_lock_);
// Allow a new incoming messages processing task to be posted. This can't be
// done after AcceptIncomingMessages() otherwise a message might be missed.
// Doing it here may result in at most two tasks existing at the same time;
// this running one, and one pending in the task runner.
incoming_messages_task_posted_ = false;
}
AcceptIncomingMessages();
}
void NodeController::DropAllPeers() {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
std::vector<scoped_refptr<NodeChannel>> all_peers;
{
base::AutoLock lock(parent_lock_);
if (bootstrap_parent_channel_) {
// |bootstrap_parent_channel_| isn't null'd here becuase we rely on its
// existence to determine whether or not this is the root node. Once
// bootstrap_parent_channel_->ShutDown() has been called,
// |bootstrap_parent_channel_| is essentially a dead object and it doesn't
// matter if it's deleted now or when |this| is deleted.
// Note: |bootstrap_parent_channel_| is only modified on the IO thread.
all_peers.push_back(bootstrap_parent_channel_);
}
}
{
base::AutoLock lock(peers_lock_);
for (const auto& peer : peers_)
all_peers.push_back(peer.second);
for (const auto& peer : pending_children_)
all_peers.push_back(peer.second);
peers_.clear();
pending_children_.clear();
pending_peer_messages_.clear();
peer_connections_.clear();
}
for (const auto& peer : all_peers)
peer->ShutDown();
if (destroy_on_io_thread_shutdown_)
delete this;
}
void NodeController::GenerateRandomPortName(ports::PortName* port_name) {
GenerateRandomName(port_name);
}
void NodeController::AllocMessage(size_t num_header_bytes,
ports::ScopedMessage* message) {
message->reset(new PortsMessage(num_header_bytes, 0, 0, nullptr));
}
void NodeController::ForwardMessage(const ports::NodeName& node,
ports::ScopedMessage message) {
DCHECK(message);
bool schedule_pump_task = false;
if (node == name_) {
// NOTE: We need to avoid re-entering the Node instance within
// ForwardMessage. Because ForwardMessage is only ever called
// (synchronously) in response to Node's ClosePort, SendMessage, or
// AcceptMessage, we flush the queue after calling any of those methods.
base::AutoLock lock(messages_lock_);
// |io_task_runner_| may be null in tests or processes that don't require
// multi-process Mojo.
schedule_pump_task = incoming_messages_.empty() && io_task_runner_ &&
!incoming_messages_task_posted_;
incoming_messages_task_posted_ |= schedule_pump_task;
incoming_messages_.emplace(std::move(message));
incoming_messages_flag_.Set(true);
} else {
SendPeerMessage(node, std::move(message));
}
if (schedule_pump_task) {
// Normally, the queue is processed after the action that added the local
// message is done (i.e. SendMessage, ClosePort, etc). However, it's also
// possible for a local message to be added as a result of a remote message,
// and OnChannelMessage() doesn't process this queue (although
// OnPortsMessage() does). There may also be other code paths, now or added
// in the future, which cause local messages to be added but don't process
// this message queue.
//
// Instead of adding a call to AcceptIncomingMessages() on every possible
// code path, post a task to the IO thread to process the queue. If the
// current call stack processes the queue, this may end up doing nothing.
io_task_runner_->PostTask(
FROM_HERE,
base::Bind(&NodeController::ProcessIncomingMessages,
base::Unretained(this)));
}
}
void NodeController::BroadcastMessage(ports::ScopedMessage message) {
CHECK_EQ(message->num_ports(), 0u);
Channel::MessagePtr channel_message =
static_cast<PortsMessage*>(message.get())->TakeChannelMessage();
CHECK(!channel_message->has_handles());
scoped_refptr<NodeChannel> broker = GetBrokerChannel();
if (broker)
broker->Broadcast(std::move(channel_message));
else
OnBroadcast(name_, std::move(channel_message));
}
void NodeController::PortStatusChanged(const ports::PortRef& port) {
scoped_refptr<ports::UserData> user_data;
node_->GetUserData(port, &user_data);
PortObserver* observer = static_cast<PortObserver*>(user_data.get());
if (observer) {
observer->OnPortStatusChanged();
} else {
DVLOG(2) << "Ignoring status change for " << port.name() << " because it "
<< "doesn't have an observer.";
}
}
void NodeController::OnAcceptChild(const ports::NodeName& from_node,
const ports::NodeName& parent_name,
const ports::NodeName& token) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
scoped_refptr<NodeChannel> parent;
{
base::AutoLock lock(parent_lock_);
if (bootstrap_parent_channel_ && parent_name_ == ports::kInvalidNodeName) {
parent_name_ = parent_name;
parent = bootstrap_parent_channel_;
}
}
if (!parent) {
DLOG(ERROR) << "Unexpected AcceptChild message from " << from_node;
DropPeer(from_node, nullptr);
return;
}
parent->SetRemoteNodeName(parent_name);
parent->AcceptParent(token, name_);
// NOTE: The child does not actually add its parent as a peer until
// receiving an AcceptBrokerClient message from the broker. The parent
// will request that said message be sent upon receiving AcceptParent.
DVLOG(1) << "Child " << name_ << " accepting parent " << parent_name;
}
void NodeController::OnAcceptParent(const ports::NodeName& from_node,
const ports::NodeName& token,
const ports::NodeName& child_name) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
auto it = pending_children_.find(from_node);
if (it == pending_children_.end() || token != from_node) {
DLOG(ERROR) << "Received unexpected AcceptParent message from "
<< from_node;
DropPeer(from_node, nullptr);
return;
}
{
base::AutoLock lock(reserved_ports_lock_);
auto it = pending_child_tokens_.find(from_node);
if (it != pending_child_tokens_.end()) {
std::string token = std::move(it->second);
pending_child_tokens_.erase(it);
pending_child_tokens_[child_name] = std::move(token);
}
}
scoped_refptr<NodeChannel> channel = it->second;
pending_children_.erase(it);
DCHECK(channel);
DVLOG(1) << "Parent " << name_ << " accepted child " << child_name;
AddPeer(child_name, channel, false /* start_channel */);
// TODO(rockot/amistry): We could simplify child initialization if we could
// synchronously get a new async broker channel from the broker. For now we do
// it asynchronously since it's only used to facilitate handle passing, not
// handle creation.
scoped_refptr<NodeChannel> broker = GetBrokerChannel();
if (broker) {
// Inform the broker of this new child.
broker->AddBrokerClient(child_name, channel->CopyRemoteProcessHandle());
} else {
// If we have no broker, either we need to wait for one, or we *are* the
// broker.
scoped_refptr<NodeChannel> parent = GetParentChannel();
if (!parent) {
base::AutoLock lock(parent_lock_);
parent = bootstrap_parent_channel_;
}
if (!parent) {
// Yes, we're the broker. We can initialize the child directly.
channel->AcceptBrokerClient(name_, ScopedPlatformHandle());
} else {
// We aren't the broker, so wait for a broker connection.
base::AutoLock lock(broker_lock_);
pending_broker_clients_.push(child_name);
}
}
}
void NodeController::OnAddBrokerClient(const ports::NodeName& from_node,
const ports::NodeName& client_name,
base::ProcessHandle process_handle) {
#if defined(OS_WIN)
// Scoped handle to avoid leaks on error.
ScopedPlatformHandle scoped_process_handle =
ScopedPlatformHandle(PlatformHandle(process_handle));
#endif
scoped_refptr<NodeChannel> sender = GetPeerChannel(from_node);
if (!sender) {
DLOG(ERROR) << "Ignoring AddBrokerClient from unknown sender.";
return;
}
if (GetPeerChannel(client_name)) {
DLOG(ERROR) << "Ignoring AddBrokerClient for known client.";
DropPeer(from_node, nullptr);
return;
}
PlatformChannelPair broker_channel;
ConnectionParams connection_params(broker_channel.PassServerHandle());
scoped_refptr<NodeChannel> client =
NodeChannel::Create(this, std::move(connection_params), io_task_runner_,
ProcessErrorCallback());
#if defined(OS_WIN)
// The broker must have a working handle to the client process in order to
// properly copy other handles to and from the client.
if (!scoped_process_handle.is_valid()) {
DLOG(ERROR) << "Broker rejecting client with invalid process handle.";
return;
}
client->SetRemoteProcessHandle(scoped_process_handle.release().handle);
#else
client->SetRemoteProcessHandle(process_handle);
#endif
AddPeer(client_name, client, true /* start_channel */);
DVLOG(1) << "Broker " << name_ << " accepting client " << client_name
<< " from peer " << from_node;
sender->BrokerClientAdded(client_name, broker_channel.PassClientHandle());
}
void NodeController::OnBrokerClientAdded(const ports::NodeName& from_node,
const ports::NodeName& client_name,
ScopedPlatformHandle broker_channel) {
scoped_refptr<NodeChannel> client = GetPeerChannel(client_name);
if (!client) {
DLOG(ERROR) << "BrokerClientAdded for unknown child " << client_name;
return;
}
// This should have come from our own broker.
if (GetBrokerChannel() != GetPeerChannel(from_node)) {
DLOG(ERROR) << "BrokerClientAdded from non-broker node " << from_node;
return;
}
DVLOG(1) << "Child " << client_name << " accepted by broker " << from_node;
client->AcceptBrokerClient(from_node, std::move(broker_channel));
}
void NodeController::OnAcceptBrokerClient(const ports::NodeName& from_node,
const ports::NodeName& broker_name,
ScopedPlatformHandle broker_channel) {
// This node should already have a parent in bootstrap mode.
ports::NodeName parent_name;
scoped_refptr<NodeChannel> parent;
{
base::AutoLock lock(parent_lock_);
parent_name = parent_name_;
parent = bootstrap_parent_channel_;
bootstrap_parent_channel_ = nullptr;
}
DCHECK(parent_name == from_node);
DCHECK(parent);
std::queue<ports::NodeName> pending_broker_clients;
std::unordered_map<ports::NodeName, OutgoingMessageQueue>
pending_relay_messages;
{
base::AutoLock lock(broker_lock_);
broker_name_ = broker_name;
std::swap(pending_broker_clients, pending_broker_clients_);
std::swap(pending_relay_messages, pending_relay_messages_);
}
DCHECK(broker_name != ports::kInvalidNodeName);
// It's now possible to add both the broker and the parent as peers.
// Note that the broker and parent may be the same node.
scoped_refptr<NodeChannel> broker;
if (broker_name == parent_name) {
DCHECK(!broker_channel.is_valid());
broker = parent;
} else {
DCHECK(broker_channel.is_valid());
broker =
NodeChannel::Create(this, ConnectionParams(std::move(broker_channel)),
io_task_runner_, ProcessErrorCallback());
AddPeer(broker_name, broker, true /* start_channel */);
}
AddPeer(parent_name, parent, false /* start_channel */);
{
// Complete any port merge requests we have waiting for the parent.
base::AutoLock lock(pending_port_merges_lock_);
for (const auto& request : pending_port_merges_)
parent->RequestPortMerge(request.second.name(), request.first);
pending_port_merges_.clear();
}
// Feed the broker any pending children of our own.
while (!pending_broker_clients.empty()) {
const ports::NodeName& child_name = pending_broker_clients.front();
auto it = pending_children_.find(child_name);
DCHECK(it != pending_children_.end());
broker->AddBrokerClient(child_name, it->second->CopyRemoteProcessHandle());
pending_broker_clients.pop();
}
#if defined(OS_WIN) || (defined(OS_MACOSX) && !defined(OS_IOS))
// Have the broker relay any messages we have waiting.
for (auto& entry : pending_relay_messages) {
const ports::NodeName& destination = entry.first;
auto& message_queue = entry.second;
while (!message_queue.empty()) {
broker->RelayPortsMessage(destination, std::move(message_queue.front()));
message_queue.pop();
}
}
#endif
DVLOG(1) << "Child " << name_ << " accepted by broker " << broker_name;
}
void NodeController::OnPortsMessage(const ports::NodeName& from_node,
Channel::MessagePtr channel_message) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
void* data;
size_t num_data_bytes, num_header_bytes, num_payload_bytes, num_ports_bytes;
if (!ParsePortsMessage(channel_message.get(), &data, &num_data_bytes,
&num_header_bytes, &num_payload_bytes,
&num_ports_bytes)) {
DropPeer(from_node, nullptr);
return;
}
CHECK(channel_message);
std::unique_ptr<PortsMessage> ports_message(
new PortsMessage(num_header_bytes,
num_payload_bytes,
num_ports_bytes,
std::move(channel_message)));
ports_message->set_source_node(from_node);
node_->AcceptMessage(ports::ScopedMessage(ports_message.release()));
AcceptIncomingMessages();
}
void NodeController::OnRequestPortMerge(
const ports::NodeName& from_node,
const ports::PortName& connector_port_name,
const std::string& token) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
DVLOG(2) << "Node " << name_ << " received RequestPortMerge for token "
<< token << " and port " << connector_port_name << "@" << from_node;
ports::PortRef local_port;
{
base::AutoLock lock(reserved_ports_lock_);
auto it = reserved_ports_.find(token);
if (it == reserved_ports_.end()) {
DVLOG(1) << "Ignoring request to connect to port for unknown token "
<< token;
return;
}
local_port = it->second.port;
reserved_ports_.erase(it);
}
int rv = node_->MergePorts(local_port, from_node, connector_port_name);
if (rv != ports::OK)
DLOG(ERROR) << "MergePorts failed: " << rv;
AcceptIncomingMessages();
}
void NodeController::OnRequestIntroduction(const ports::NodeName& from_node,
const ports::NodeName& name) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
scoped_refptr<NodeChannel> requestor = GetPeerChannel(from_node);
if (from_node == name || name == ports::kInvalidNodeName || !requestor) {
DLOG(ERROR) << "Rejecting invalid OnRequestIntroduction message from "
<< from_node;
DropPeer(from_node, nullptr);
return;
}
scoped_refptr<NodeChannel> new_friend = GetPeerChannel(name);
if (!new_friend) {
// We don't know who they're talking about!
requestor->Introduce(name, ScopedPlatformHandle());
} else {
PlatformChannelPair new_channel;
requestor->Introduce(name, new_channel.PassServerHandle());
new_friend->Introduce(from_node, new_channel.PassClientHandle());
}
}
void NodeController::OnIntroduce(const ports::NodeName& from_node,
const ports::NodeName& name,
ScopedPlatformHandle channel_handle) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
if (!channel_handle.is_valid()) {
node_->LostConnectionToNode(name);
DVLOG(1) << "Could not be introduced to peer " << name;
base::AutoLock lock(peers_lock_);
pending_peer_messages_.erase(name);
return;
}
scoped_refptr<NodeChannel> channel =
NodeChannel::Create(this, ConnectionParams(std::move(channel_handle)),
io_task_runner_, ProcessErrorCallback());
DVLOG(1) << "Adding new peer " << name << " via parent introduction.";
AddPeer(name, channel, true /* start_channel */);
}
void NodeController::OnBroadcast(const ports::NodeName& from_node,
Channel::MessagePtr message) {
DCHECK(!message->has_handles());
void* data;
size_t num_data_bytes, num_header_bytes, num_payload_bytes, num_ports_bytes;
if (!ParsePortsMessage(message.get(), &data, &num_data_bytes,
&num_header_bytes, &num_payload_bytes,
&num_ports_bytes)) {
DropPeer(from_node, nullptr);
return;
}
// Broadcast messages must not contain ports.
if (num_ports_bytes > 0) {
DropPeer(from_node, nullptr);
return;
}
base::AutoLock lock(peers_lock_);
for (auto& iter : peers_) {
// Copy and send the message to each known peer.
Channel::MessagePtr peer_message(
new Channel::Message(message->payload_size(), 0));
memcpy(peer_message->mutable_payload(), message->payload(),
message->payload_size());
iter.second->PortsMessage(std::move(peer_message));
}
}
#if defined(OS_WIN) || (defined(OS_MACOSX) && !defined(OS_IOS))
void NodeController::OnRelayPortsMessage(const ports::NodeName& from_node,
base::ProcessHandle from_process,
const ports::NodeName& destination,
Channel::MessagePtr message) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
if (GetBrokerChannel()) {
// Only the broker should be asked to relay a message.
LOG(ERROR) << "Non-broker refusing to relay message.";
DropPeer(from_node, nullptr);
return;
}
// The parent should always know which process this came from.
DCHECK(from_process != base::kNullProcessHandle);
#if defined(OS_WIN)
// Rewrite the handles to this (the parent) process. If the message is
// destined for another child process, the handles will be rewritten to that
// process before going out (see NodeChannel::WriteChannelMessage).
//
// TODO: We could avoid double-duplication.
//
// Note that we explicitly mark the handles as being owned by the sending
// process before rewriting them, in order to accommodate RewriteHandles'
// internal sanity checks.
ScopedPlatformHandleVectorPtr handles = message->TakeHandles();
for (size_t i = 0; i < handles->size(); ++i)
(*handles)[i].owning_process = from_process;
if (!Channel::Message::RewriteHandles(from_process,
base::GetCurrentProcessHandle(),
handles.get())) {
DLOG(ERROR) << "Failed to relay one or more handles.";
}
message->SetHandles(std::move(handles));
#else
MachPortRelay* relay = GetMachPortRelay();
if (!relay) {
LOG(ERROR) << "Receiving Mach ports without a port relay from "
<< from_node << ". Dropping message.";
return;
}
if (!relay->ExtractPortRights(message.get(), from_process)) {
// NodeChannel should ensure that MachPortRelay is ready for the remote
// process. At this point, if the port extraction failed, either something
// went wrong in the mach stuff, or the remote process died.
LOG(ERROR) << "Error on receiving Mach ports " << from_node
<< ". Dropping message.";
return;
}
#endif // defined(OS_WIN)
if (destination == name_) {
// Great, we can deliver this message locally.
OnPortsMessage(from_node, std::move(message));
return;
}
scoped_refptr<NodeChannel> peer = GetPeerChannel(destination);
if (peer)
peer->PortsMessageFromRelay(from_node, std::move(message));
else
DLOG(ERROR) << "Dropping relay message for unknown node " << destination;
}
void NodeController::OnPortsMessageFromRelay(const ports::NodeName& from_node,
const ports::NodeName& source_node,
Channel::MessagePtr message) {
if (GetPeerChannel(from_node) != GetBrokerChannel()) {
LOG(ERROR) << "Refusing relayed message from non-broker node.";
DropPeer(from_node, nullptr);
return;
}
OnPortsMessage(source_node, std::move(message));
}
#endif
void NodeController::OnAcceptPeer(const ports::NodeName& from_node,
const ports::NodeName& token,
const ports::NodeName& peer_name,
const ports::PortName& port_name) {
DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
auto it = peer_connections_.find(from_node);
if (it == peer_connections_.end()) {
DLOG(ERROR) << "Received unexpected AcceptPeer message from " << from_node;
DropPeer(from_node, nullptr);
return;
}
scoped_refptr<NodeChannel> channel = std::move(it->second.channel);
ports::PortRef local_port = it->second.local_port;
std::string peer_token = std::move(it->second.peer_token);
peer_connections_.erase(it);
DCHECK(channel);
// If the peer connection is a self connection (which is used in tests),
// drop the channel to it and skip straight to merging the ports.
if (name_ == peer_name) {
peers_by_token_.erase(peer_token);
} else {
peers_by_token_[peer_token] = peer_name;
peer_connections_.insert(
{peer_name, PeerConnection{nullptr, local_port, peer_token}});
DVLOG(1) << "Node " << name_ << " accepted peer " << peer_name;
AddPeer(peer_name, channel, false /* start_channel */);
}
// We need to choose one side to initiate the port merge. It doesn't matter
// who does it as long as they don't both try. Simple solution: pick the one
// with the "smaller" port name.
if (local_port.name() < port_name) {
node()->MergePorts(local_port, peer_name, port_name);
}
}
void NodeController::OnChannelError(const ports::NodeName& from_node,
NodeChannel* channel) {
if (io_task_runner_->RunsTasksOnCurrentThread()) {
DropPeer(from_node, channel);
// DropPeer may have caused local port closures, so be sure to process any
// pending local messages.
AcceptIncomingMessages();
} else {
io_task_runner_->PostTask(
FROM_HERE,
base::Bind(&NodeController::OnChannelError, base::Unretained(this),
from_node, channel));
}
}
#if defined(OS_MACOSX) && !defined(OS_IOS)
MachPortRelay* NodeController::GetMachPortRelay() {
{
base::AutoLock lock(parent_lock_);
// Return null if we're not the root.
if (bootstrap_parent_channel_ || parent_name_ != ports::kInvalidNodeName)
return nullptr;
}
base::AutoLock lock(mach_port_relay_lock_);
return mach_port_relay_.get();
}
#endif
void NodeController::CancelPendingPortMerges() {
std::vector<ports::PortRef> ports_to_close;
{
base::AutoLock lock(pending_port_merges_lock_);
reject_pending_merges_ = true;
for (const auto& port : pending_port_merges_)
ports_to_close.push_back(port.second);
pending_port_merges_.clear();
}
for (const auto& port : ports_to_close)
node_->ClosePort(port);
}
void NodeController::DestroyOnIOThreadShutdown() {
destroy_on_io_thread_shutdown_ = true;
}
void NodeController::AttemptShutdownIfRequested() {
if (!shutdown_callback_flag_)
return;
base::Closure callback;
{
base::AutoLock lock(shutdown_lock_);
if (shutdown_callback_.is_null())
return;
if (!node_->CanShutdownCleanly(
ports::Node::ShutdownPolicy::ALLOW_LOCAL_PORTS)) {
DVLOG(2) << "Unable to cleanly shut down node " << name_;
return;
}
callback = shutdown_callback_;
shutdown_callback_.Reset();
shutdown_callback_flag_.Set(false);
}
DCHECK(!callback.is_null());
callback.Run();
}
NodeController::PeerConnection::PeerConnection() = default;
NodeController::PeerConnection::PeerConnection(
const PeerConnection& other) = default;
NodeController::PeerConnection::PeerConnection(
PeerConnection&& other) = default;
NodeController::PeerConnection::PeerConnection(
scoped_refptr<NodeChannel> channel,
const ports::PortRef& local_port,
const std::string& peer_token)
: channel(std::move(channel)),
local_port(local_port),
peer_token(peer_token) {}
NodeController::PeerConnection::~PeerConnection() = default;
NodeController::PeerConnection& NodeController::PeerConnection::
operator=(const PeerConnection& other) = default;
NodeController::PeerConnection& NodeController::PeerConnection::
operator=(PeerConnection&& other) = default;
} // namespace edk
} // namespace mojo