gecko-dev/dom/media/webrtc/MediaEngineWebRTC.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=8 et ft=cpp : */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "MediaEngineWebRTC.h"

#include "AllocationHandle.h"
#include "CamerasChild.h"
#include "CSFLog.h"
#include "MediaEngineTabVideoSource.h"
#include "MediaEngineRemoteVideoSource.h"
#include "MediaTrackConstraints.h"
#include "mozilla/Logging.h"
#include "nsIComponentRegistrar.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsITabSource.h"
#include "prenv.h"

static mozilla::LazyLogModule sGetUserMediaLog("GetUserMedia");
#undef LOG
#define LOG(args) MOZ_LOG(sGetUserMediaLog, mozilla::LogLevel::Debug, args)

namespace mozilla {

// statics from AudioInputCubeb
nsTArray<int>* AudioInputCubeb::mDeviceIndexes;
int AudioInputCubeb::mDefaultDevice = -1;
nsTArray<nsCString>* AudioInputCubeb::mDeviceNames;
cubeb_device_collection AudioInputCubeb::mDevices = { nullptr, 0 };
bool AudioInputCubeb::mAnyInUse = false;
StaticMutex AudioInputCubeb::sMutex;
uint32_t AudioInputCubeb::sUserChannelCount = 0;

// AudioDeviceID is an annoying opaque value that's really a string
// pointer, and is freed when the cubeb_device_collection is destroyed

void AudioInputCubeb::UpdateDeviceList()
{
  // We keep all the device names, but wipe the mappings and rebuild them.
  // Do this first so that if cubeb has failed we've unmapped our devices
  // before we early return. Otherwise we'd keep the old list.
  for (auto& device_index : (*mDeviceIndexes)) {
    device_index = -1; // unmapped
  }

  cubeb* cubebContext = CubebUtils::GetCubebContext();
  if (!cubebContext) {
    return;
  }

  cubeb_device_collection devices = { nullptr, 0 };

  if (CUBEB_OK != cubeb_enumerate_devices(cubebContext,
                                          CUBEB_DEVICE_TYPE_INPUT,
                                          &devices)) {
    return;
  }

  // Calculate translation from existing mDevices to new devices. Note we
  // never end up with less devices than before, since people have
  // stashed indexes.
  // For some reason the "fake" device for automation is marked as DISABLED,
  // so white-list it.
  mDefaultDevice = -1;
  for (uint32_t i = 0; i < devices.count; i++) {
    LOG(("Cubeb device %u: type 0x%x, state 0x%x, name %s, id %p",
         i, devices.device[i].type, devices.device[i].state,
         devices.device[i].friendly_name, devices.device[i].device_id));
    if (devices.device[i].type == CUBEB_DEVICE_TYPE_INPUT && // paranoia
        devices.device[i].state == CUBEB_DEVICE_STATE_ENABLED )
    {
      auto j = mDeviceNames->IndexOf(devices.device[i].device_id);
      if (j != nsTArray<nsCString>::NoIndex) {
        // match! update the mapping
        (*mDeviceIndexes)[j] = i;
      } else {
        // new device, add to the array
        mDeviceIndexes->AppendElement(i);
        mDeviceNames->AppendElement(devices.device[i].device_id);
        j = mDeviceIndexes->Length()-1;
      }
      if (devices.device[i].preferred & CUBEB_DEVICE_PREF_VOICE) {
        // There can be only one... we hope
        NS_ASSERTION(mDefaultDevice == -1, "multiple default cubeb input devices!");
        mDefaultDevice = j;
      }
    }
  }
  LOG(("Cubeb default input device %d", mDefaultDevice));
  StaticMutexAutoLock lock(sMutex);
  // swap state
  cubeb_device_collection_destroy(cubebContext, &mDevices);
  mDevices = devices;
}

MediaEngineWebRTC::MediaEngineWebRTC(MediaEnginePrefs &aPrefs)
  : mMutex("MediaEngineWebRTC::mMutex"),
    mAudioInput(nullptr),
    mFullDuplex(aPrefs.mFullDuplex),
    mDelayAgnostic(aPrefs.mDelayAgnostic),
    mExtendedFilter(aPrefs.mExtendedFilter),
    mHasTabVideoSource(false)
{
  nsCOMPtr<nsIComponentRegistrar> compMgr;
  NS_GetComponentRegistrar(getter_AddRefs(compMgr));
  if (compMgr) {
    compMgr->IsContractIDRegistered(NS_TABSOURCESERVICE_CONTRACTID, &mHasTabVideoSource);
  }

  camera::GetChildAndCall(
    &camera::CamerasChild::AddDeviceChangeCallback,
    this);
}

void
MediaEngineWebRTC::SetFakeDeviceChangeEvents()
{
  camera::GetChildAndCall(
    &camera::CamerasChild::SetFakeDeviceChangeEvents);
}

void
MediaEngineWebRTC::EnumerateVideoDevices(uint64_t aWindowId,
                                         dom::MediaSourceEnum aMediaSource,
                                         nsTArray<RefPtr<MediaEngineSource> >* aSources)
{
  mMutex.AssertCurrentThreadOwns();

  mozilla::camera::CaptureEngine capEngine = mozilla::camera::InvalidEngine;

  bool scaryKind = false; // flag sources with cross-origin exploit potential

  switch (aMediaSource) {
    case dom::MediaSourceEnum::Window:
      capEngine = mozilla::camera::WinEngine;
      break;
    case dom::MediaSourceEnum::Application:
      capEngine = mozilla::camera::AppEngine;
      break;
    case dom::MediaSourceEnum::Screen:
      capEngine = mozilla::camera::ScreenEngine;
      scaryKind = true;
      break;
    case dom::MediaSourceEnum::Browser:
      capEngine = mozilla::camera::BrowserEngine;
      scaryKind = true;
      break;
    case dom::MediaSourceEnum::Camera:
      capEngine = mozilla::camera::CameraEngine;
      break;
    default:
      MOZ_CRASH("No valid video engine");
      break;
  }

  /*
   * We still enumerate every time, in case a new device was plugged in since
   * the last call. TODO: Verify that WebRTC actually does deal with hotplugging
   * new devices (with or without new engine creation) and accordingly adjust.
   * Enumeration is not neccessary if GIPS reports the same set of devices
   * for a given instance of the engine. Likewise, if a device was plugged out,
   * mVideoSources must be updated.
   */
  int num;
  num = mozilla::camera::GetChildAndCall(
    &mozilla::camera::CamerasChild::NumberOfCaptureDevices,
    capEngine);

  for (int i = 0; i < num; i++) {
    char deviceName[MediaEngineSource::kMaxDeviceNameLength];
    char uniqueId[MediaEngineSource::kMaxUniqueIdLength];
    bool scarySource = false;

    // paranoia
    deviceName[0] = '\0';
    uniqueId[0] = '\0';
    int error;

    error =  mozilla::camera::GetChildAndCall(
      &mozilla::camera::CamerasChild::GetCaptureDevice,
      capEngine,
      i, deviceName,
      sizeof(deviceName), uniqueId,
      sizeof(uniqueId),
      &scarySource);
    if (error) {
      LOG(("camera:GetCaptureDevice: Failed %d", error ));
      continue;
    }
#ifdef DEBUG
    LOG(("  Capture Device Index %d, Name %s", i, deviceName));

    webrtc::CaptureCapability cap;
    int numCaps = mozilla::camera::GetChildAndCall(
      &mozilla::camera::CamerasChild::NumberOfCapabilities,
      capEngine,
      uniqueId);
    LOG(("Number of Capabilities %d", numCaps));
    for (int j = 0; j < numCaps; j++) {
      if (mozilla::camera::GetChildAndCall(
            &mozilla::camera::CamerasChild::GetCaptureCapability,
            capEngine,
            uniqueId,
            j, cap) != 0) {
       break;
      }
      LOG(("type=%d width=%d height=%d maxFPS=%d",
           cap.rawType, cap.width, cap.height, cap.maxFPS ));
    }
#endif

    if (uniqueId[0] == '\0') {
      // In case a device doesn't set uniqueId!
      strncpy(uniqueId, deviceName, sizeof(uniqueId));
      uniqueId[sizeof(uniqueId)-1] = '\0'; // strncpy isn't safe
    }

    NS_ConvertUTF8toUTF16 uuid(uniqueId);
    RefPtr<MediaEngineSource> vSource;

    nsRefPtrHashtable<nsStringHashKey, MediaEngineSource>*
      devicesForThisWindow = mVideoSources.LookupOrAdd(aWindowId);

    if (devicesForThisWindow->Get(uuid, getter_AddRefs(vSource)) &&
        vSource->RequiresSharing()) {
      // We've already seen this shared device, just refresh and append.
      static_cast<MediaEngineRemoteVideoSource*>(vSource.get())->Refresh(i);
      aSources->AppendElement(vSource.get());
    } else {
      vSource = new MediaEngineRemoteVideoSource(i, capEngine, aMediaSource,
                                                 scaryKind || scarySource);
      devicesForThisWindow->Put(uuid, vSource);
      aSources->AppendElement(vSource);
    }
  }

  if (mHasTabVideoSource || dom::MediaSourceEnum::Browser == aMediaSource) {
    aSources->AppendElement(new MediaEngineTabVideoSource());
  }
}

void
MediaEngineWebRTC::EnumerateMicrophoneDevices(uint64_t aWindowId,
                                              nsTArray<RefPtr<MediaEngineSource> >* aSources)
{
  mMutex.AssertCurrentThreadOwns();

  if (!mAudioInput) {
    if (!SupportsDuplex()) {
      return;
    }
    mAudioInput = new mozilla::AudioInputCubeb();
  }

  int nDevices = 0;
  mAudioInput->GetNumOfRecordingDevices(nDevices);
  int i;
#if defined(MOZ_WIDGET_ANDROID)
  i = 0; // Bug 1037025 - let the OS handle defaulting for now on android/b2g
#else
  // -1 is "default communications device" depending on OS in webrtc.org code
  i = -1;
#endif
  for (; i < nDevices; i++) {
    // We use constants here because GetRecordingDeviceName takes char[128].
    char deviceName[128];
    char uniqueId[128];
    // paranoia; jingle doesn't bother with this
    deviceName[0] = '\0';
    uniqueId[0] = '\0';

    int error = mAudioInput->GetRecordingDeviceName(i, deviceName, uniqueId);
    if (error) {
      LOG((" AudioInput::GetRecordingDeviceName: Failed %d", error));
      continue;
    }

    if (uniqueId[0] == '\0') {
      // Mac and Linux don't set uniqueId!
      strcpy(uniqueId, deviceName); // safe given assert and initialization/error-check
    }


    RefPtr<MediaEngineSource> aSource;
    NS_ConvertUTF8toUTF16 uuid(uniqueId);

    nsRefPtrHashtable<nsStringHashKey, MediaEngineSource>*
      devicesForThisWindow = mAudioSources.LookupOrAdd(aWindowId);

    if (devicesForThisWindow->Get(uuid, getter_AddRefs(aSource)) &&
        aSource->RequiresSharing()) {
      // We've already seen this device, just append.
      aSources->AppendElement(aSource.get());
    } else {
      aSource = new MediaEngineWebRTCMicrophoneSource(
          new mozilla::AudioInputCubeb(i),
          i, deviceName, uniqueId,
          mDelayAgnostic, mExtendedFilter);
      devicesForThisWindow->Put(uuid, aSource);
      aSources->AppendElement(aSource);
    }
  }
}

void
MediaEngineWebRTC::EnumerateDevices(uint64_t aWindowId,
                                    dom::MediaSourceEnum aMediaSource,
                                    nsTArray<RefPtr<MediaEngineSource> >* aSources)
{
  // We spawn threads to handle gUM runnables, so we must protect the member vars
  MutexAutoLock lock(mMutex);
  if (MediaEngineSource::IsVideo(aMediaSource)) {
    EnumerateVideoDevices(aWindowId, aMediaSource, aSources);
  } else if (aMediaSource == dom::MediaSourceEnum::AudioCapture) {
    RefPtr<MediaEngineWebRTCAudioCaptureSource> audioCaptureSource =
      new MediaEngineWebRTCAudioCaptureSource(nullptr);
    aSources->AppendElement(audioCaptureSource);
  } else {
    MOZ_ASSERT(aMediaSource == dom::MediaSourceEnum::Microphone);
    EnumerateMicrophoneDevices(aWindowId, aSources);
  }
}

bool
MediaEngineWebRTC::SupportsDuplex()
{
  return mFullDuplex;
}

void
MediaEngineWebRTC::ReleaseResourcesForWindow(uint64_t aWindowId)
{
  {
    nsRefPtrHashtable<nsStringHashKey, MediaEngineSource>*
      audioDevicesForThisWindow = mAudioSources.Get(aWindowId);

    if (audioDevicesForThisWindow) {
      for (auto iter = audioDevicesForThisWindow->Iter(); !iter.Done();
           iter.Next()) {
        iter.UserData()->Shutdown();
      }

      // This makes audioDevicesForThisWindow invalid.
      mAudioSources.Remove(aWindowId);
    }
  }

  {
    nsRefPtrHashtable<nsStringHashKey, MediaEngineSource>*
      videoDevicesForThisWindow = mVideoSources.Get(aWindowId);
    if (videoDevicesForThisWindow) {
      for (auto iter = videoDevicesForThisWindow->Iter(); !iter.Done();
           iter.Next()) {
        iter.UserData()->Shutdown();
      }

      // This makes videoDevicesForThisWindow invalid.
      mVideoSources.Remove(aWindowId);
    }
  }
}

namespace {
template<typename T>
void ShutdownSources(T& aHashTable)
{
  for (auto iter = aHashTable.Iter(); !iter.Done(); iter.Next()) {
    for (auto iterInner = iter.UserData()->Iter(); !iterInner.Done();
         iterInner.Next()) {
      MediaEngineSource* source = iterInner.UserData();
      source->Shutdown();
    }
  }
}
}

void
MediaEngineWebRTC::Shutdown()
{
  // This is likely paranoia
  MutexAutoLock lock(mMutex);

  if (camera::GetCamerasChildIfExists()) {
    camera::GetChildAndCall(
      &camera::CamerasChild::RemoveDeviceChangeCallback, this);
  }

  LOG(("%s", __FUNCTION__));
  // Shutdown all the sources, since we may have dangling references to the
  // sources in nsDOMUserMediaStreams waiting for GC/CC
  ShutdownSources(mVideoSources);
  ShutdownSources(mAudioSources);

  mozilla::camera::Shutdown();
  AudioInputCubeb::CleanupGlobalData();
}

}