Web MIDI: implement right sysex handling for received messages.

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"
@@ skipping 118 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");
 
-  // For now disallow all System Exclusive messages even if we
-  // have permission.
-  // TODO(toyoshim): allow System Exclusive if browser has granted
-  // this client access.  We'll likely need to pass a GURL
-  // here to compare against our permissions.
-  if (length > 0 && data[0] >= kSysExMessage)
+  // 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;
+    }
+  }
 
   // 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