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// Copyright (c) 2013 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 "content/browser/media/midi_host.h"
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/memory/ptr_util.h"
#include "base/process/process.h"
#include "base/trace_event/trace_event.h"
#include "content/browser/bad_message.h"
#include "content/browser/browser_main_loop.h"
#include "content/browser/child_process_security_policy_impl.h"
#include "content/common/media/midi_messages.h"
#include "content/public/browser/content_browser_client.h"
#include "media/midi/message_util.h"
#include "media/midi/midi_message_queue.h"
#include "media/midi/midi_service.h"
namespace content {
namespace {
// The total number of bytes which we're allowed to send to the OS
// before knowing that they have been successfully sent.
const size_t kMaxInFlightBytes = 10 * 1024 * 1024; // 10 MB.
// We keep track of the number of bytes successfully sent to
// the hardware. Every once in a while we report back to the renderer
// the number of bytes sent since the last report. This threshold determines
// how many bytes will be sent before reporting back to the renderer.
const size_t kAcknowledgementThresholdBytes = 1024 * 1024; // 1 MB.
} // namespace
using midi::IsDataByte;
using midi::IsSystemRealTimeMessage;
using midi::IsValidWebMIDIData;
using midi::MidiPortInfo;
using midi::kSysExByte;
using midi::kEndOfSysExByte;
using midi::mojom::PortState;
using midi::mojom::Result;
MidiHost::MidiHost(int renderer_process_id, midi::MidiService* midi_service)
: BrowserMessageFilter(MidiMsgStart),
renderer_process_id_(renderer_process_id),
has_sys_ex_permission_(false),
is_session_requested_(false),
midi_service_(midi_service),
sent_bytes_in_flight_(0),
bytes_sent_since_last_acknowledgement_(0),
output_port_count_(0) {
DCHECK(midi_service_);
}
MidiHost::~MidiHost() = default;
void MidiHost::OnChannelClosing() {
// If we get here the MidiHost is going to be destroyed soon. Prevent any
// subsequent calls from MidiService by closing our session.
// If Send() is called from a different thread (e.g. a separate thread owned
// by the MidiService implementation), it will get posted to the IO thread.
// There is a race condition here if our refcount is 0 and we're about to or
// have already entered OnDestruct().
if (is_session_requested_ && midi_service_) {
midi_service_->EndSession(this);
is_session_requested_ = false;
}
}
void MidiHost::OnDestruct() const {
BrowserThread::DeleteOnIOThread::Destruct(this);
}
// IPC Messages handler
bool MidiHost::OnMessageReceived(const IPC::Message& message) {
bool handled = true;
IPC_BEGIN_MESSAGE_MAP(MidiHost, message)
IPC_MESSAGE_HANDLER(MidiHostMsg_StartSession, OnStartSession)
IPC_MESSAGE_HANDLER(MidiHostMsg_SendData, OnSendData)
IPC_MESSAGE_HANDLER(MidiHostMsg_EndSession, OnEndSession)
IPC_MESSAGE_UNHANDLED(handled = false)
IPC_END_MESSAGE_MAP()
return handled;
}
void MidiHost::OnStartSession() {
is_session_requested_ = true;
if (midi_service_)
midi_service_->StartSession(this);
}
void MidiHost::OnSendData(uint32_t port,
const std::vector<uint8_t>& data,
double timestamp) {
{
base::AutoLock auto_lock(output_port_count_lock_);
if (output_port_count_ <= port) {
bad_message::ReceivedBadMessage(this, bad_message::MH_INVALID_MIDI_PORT);
return;
}
}
if (data.empty())
return;
// Blink running in a renderer checks permission to raise a SecurityError
// in JavaScript. The actual permission check for security purposes
// happens here in the browser process.
if (!has_sys_ex_permission_ &&
std::find(data.begin(), data.end(), kSysExByte) != data.end()) {
bad_message::ReceivedBadMessage(this, bad_message::MH_SYS_EX_PERMISSION);
return;
}
if (!IsValidWebMIDIData(data))
return;
{
base::AutoLock auto_lock(in_flight_lock_);
// Sanity check that we won't send too much data.
// TODO(yukawa): Consider to send an error event back to the renderer
// after some future discussion in W3C.
if (data.size() + sent_bytes_in_flight_ > kMaxInFlightBytes)
return;
sent_bytes_in_flight_ += data.size();
}
if (midi_service_)
midi_service_->DispatchSendMidiData(this, port, data, timestamp);
}
void MidiHost::OnEndSession() {
is_session_requested_ = false;
if (midi_service_)
midi_service_->EndSession(this);
}
void MidiHost::CompleteStartSession(Result result) {
DCHECK(is_session_requested_);
if (result == Result::OK) {
// ChildSecurityPolicy is set just before OnStartSession by
// MidiDispatcherHost. So we can safely cache the policy.
has_sys_ex_permission_ = ChildProcessSecurityPolicyImpl::GetInstance()->
CanSendMidiSysExMessage(renderer_process_id_);
}
Send(new MidiMsg_SessionStarted(result));
}
void MidiHost::AddInputPort(const MidiPortInfo& info) {
base::AutoLock auto_lock(messages_queues_lock_);
// MidiMessageQueue is created later in ReceiveMidiData().
received_messages_queues_.push_back(nullptr);
Send(new MidiMsg_AddInputPort(info));
}
void MidiHost::AddOutputPort(const MidiPortInfo& info) {
base::AutoLock auto_lock(output_port_count_lock_);
output_port_count_++;
Send(new MidiMsg_AddOutputPort(info));
}
void MidiHost::SetInputPortState(uint32_t port, PortState state) {
Send(new MidiMsg_SetInputPortState(port, state));
}
void MidiHost::SetOutputPortState(uint32_t port, PortState state) {
Send(new MidiMsg_SetOutputPortState(port, state));
}
void MidiHost::ReceiveMidiData(uint32_t port,
const uint8_t* data,
size_t length,
double timestamp) {
TRACE_EVENT0("midi", "MidiHost::ReceiveMidiData");
base::AutoLock auto_lock(messages_queues_lock_);
if (received_messages_queues_.size() <= port)
return;
// Lazy initialization
if (received_messages_queues_[port] == nullptr)
received_messages_queues_[port] =
base::MakeUnique<midi::MidiMessageQueue>(true);
received_messages_queues_[port]->Add(data, length);
std::vector<uint8_t> message;
while (true) {
received_messages_queues_[port]->Get(&message);
if (message.empty())
break;
// MIDI devices may send a system exclusive messages even if the renderer
// doesn't have a permission to receive it. Don't kill the renderer as
// OnSendData() does.
if (message[0] == kSysExByte && !has_sys_ex_permission_)
continue;
// Send to the renderer.
Send(new MidiMsg_DataReceived(port, message, timestamp));
}
}
void MidiHost::AccumulateMidiBytesSent(size_t n) {
{
base::AutoLock auto_lock(in_flight_lock_);
if (n <= sent_bytes_in_flight_)
sent_bytes_in_flight_ -= n;
}
if (bytes_sent_since_last_acknowledgement_ + n >=
bytes_sent_since_last_acknowledgement_)
bytes_sent_since_last_acknowledgement_ += n;
if (bytes_sent_since_last_acknowledgement_ >=
kAcknowledgementThresholdBytes) {
Send(new MidiMsg_AcknowledgeSentData(
bytes_sent_since_last_acknowledgement_));
bytes_sent_since_last_acknowledgement_ = 0;
}
}
void MidiHost::Detach() {
midi_service_ = nullptr;
}
} // namespace content
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