Use MIDIMessageQueue/IsValidWebMIDIData for MIDI byte stream validation

content/browser/renderer_host/media/midi_host.cc

 // 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/renderer_host/media/midi_host.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/debug/trace_event.h"
 #include "base/process/process.h"
 #include "content/browser/browser_main_loop.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/media/media_internals.h"
 #include "content/common/media/midi_messages.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/media_observer.h"
 #include "content/public/browser/user_metrics.h"
 #include "media/midi/midi_manager.h"
+#include "media/midi/midi_message_queue.h"
 
 using media::MIDIManager;
 using media::MIDIPortInfoList;
 
 // The total number of bytes which we're allowed to send to the OS
 // before knowing that they have been successfully sent.
 static 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
@@ skipping 39 matching lines @@
   MIDIPortInfoList input_ports;
   MIDIPortInfoList output_ports;
 
   // Initialize devices and register to receive MIDI data.
   bool success = false;
   if (midi_manager_) {
     success = midi_manager_->StartSession(this);
     if (success) {
       input_ports = midi_manager_->input_ports();
       output_ports = midi_manager_->output_ports();
+      received_messages_queues_.clear();
+      received_messages_queues_.resize(input_ports.size());
     }
   }
 
   Send(new MIDIMsg_SessionStarted(
        client_id,
        success,
        input_ports,
        output_ports));
 }
 
@@ skipping 35 matching lines @@
   sent_bytes_in_flight_ += data.size();
 }
 
 void MIDIHost::ReceiveMIDIData(
     uint32 port,
     const uint8* data,
     size_t length,
     double timestamp) {
   TRACE_EVENT0("midi", "MIDIHost::ReceiveMIDIData");
 
-  // Check a process security policy to receive a system exclusive message.
-  if (length > 0 && data[0] >= kSysExMessage) {
-    if (!ChildProcessSecurityPolicyImpl::GetInstance()->CanSendMIDISysExMessage(
-        renderer_process_id_)) {
-      // 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.
-      return;
+  if (received_messages_queues_.size() <= port)
+    return;
+
+  // Lazy initialization
+  if (received_messages_queues_[port] == NULL)
+    received_messages_queues_[port] = new media::MIDIMessageQueue(true);
+
+  bool sys_ex_allowed = false;
+  bool sys_ex_allowed_initialized = false;
+
+  received_messages_queues_[port]->Add(data, length);
+  std::vector<uint8> 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] == kSysExMessage) {

[yukawa, 2013/11/14 14:55:31]

This condition is slightly different from the previous one, which rejected not
only 0xf0 but also [0xf1, 0xff].  Please let me know if we should keep the
previous condition.

[Takashi Toyoshima, 2013/11/19 01:08:37]

I chatted this with Chris, and double checked that it's ok to pass non-sysex
0xf* messages here.
So your implementation is right.

+      // Lazily check if SysEx is allowed or not in case checking this is
+      // costly.
+      if (!sys_ex_allowed_initialized) {
+        sys_ex_allowed = ChildProcessSecurityPolicyImpl::GetInstance()->
+            CanSendMIDISysExMessage(renderer_process_id_);
+        sys_ex_allowed_initialized = true;
+      }
+      if (!sys_ex_allowed)
+        continue;
     }
+
+    // Send to the renderer.
+    Send(new MIDIMsg_DataReceived(port, message, timestamp));
   }
-
-  // Send to the renderer.
-  std::vector<uint8> v(data, data + length);
-  Send(new MIDIMsg_DataReceived(port, v, 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;
   }
 }
 
 }  // namespace content