1/*
2 * libjingle
3 * Copyright 2004 Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "talk/media/devices/linuxdevicemanager.h"
29
30#include <unistd.h>
31#include "talk/media/base/mediacommon.h"
32#include "talk/media/devices/libudevsymboltable.h"
33#include "talk/media/devices/v4llookup.h"
34#include "webrtc/sound/platformsoundsystem.h"
35#include "webrtc/sound/platformsoundsystemfactory.h"
36#include "webrtc/sound/sounddevicelocator.h"
37#include "webrtc/sound/soundsysteminterface.h"
38#include "webrtc/base/fileutils.h"
39#include "webrtc/base/linux.h"
40#include "webrtc/base/logging.h"
41#include "webrtc/base/pathutils.h"
42#include "webrtc/base/physicalsocketserver.h"
43#include "webrtc/base/stream.h"
44#include "webrtc/base/stringutils.h"
45#include "webrtc/base/thread.h"
46
47namespace cricket {
48
49DeviceManagerInterface* DeviceManagerFactory::Create() {
50  return new LinuxDeviceManager();
51}
52
53class LinuxDeviceWatcher
54    : public DeviceWatcher,
55      private rtc::Dispatcher {
56 public:
57  explicit LinuxDeviceWatcher(DeviceManagerInterface* dm);
58  virtual ~LinuxDeviceWatcher();
59  virtual bool Start();
60  virtual void Stop();
61
62 private:
63  virtual uint32 GetRequestedEvents();
64  virtual void OnPreEvent(uint32 ff);
65  virtual void OnEvent(uint32 ff, int err);
66  virtual int GetDescriptor();
67  virtual bool IsDescriptorClosed();
68
69  DeviceManagerInterface* manager_;
70  LibUDevSymbolTable libudev_;
71  struct udev* udev_;
72  struct udev_monitor* udev_monitor_;
73  bool registered_;
74};
75
76static const char* const kFilteredAudioDevicesName[] = {
77#if defined(CHROMEOS)
78    "surround40:",
79    "surround41:",
80    "surround50:",
81    "surround51:",
82    "surround71:",
83    "iec958:",      // S/PDIF
84#endif
85    NULL,
86};
87static const char* kFilteredVideoDevicesName[] = {
88    NULL,
89};
90
91LinuxDeviceManager::LinuxDeviceManager()
92    : sound_system_(new rtc::PlatformSoundSystemFactory()) {
93  set_watcher(new LinuxDeviceWatcher(this));
94}
95
96LinuxDeviceManager::~LinuxDeviceManager() {
97}
98
99bool LinuxDeviceManager::GetAudioDevices(bool input,
100                                         std::vector<Device>* devs) {
101  devs->clear();
102  if (!sound_system_.get()) {
103    return false;
104  }
105  rtc::SoundSystemInterface::SoundDeviceLocatorList list;
106  bool success;
107  if (input) {
108    success = sound_system_->EnumerateCaptureDevices(&list);
109  } else {
110    success = sound_system_->EnumeratePlaybackDevices(&list);
111  }
112  if (!success) {
113    LOG(LS_ERROR) << "Can't enumerate devices";
114    sound_system_.release();
115    return false;
116  }
117  // We have to start the index at 1 because webrtc VoiceEngine puts the default
118  // device at index 0, but Enumerate(Capture|Playback)Devices does not include
119  // a locator for the default device.
120  int index = 1;
121  for (rtc::SoundSystemInterface::SoundDeviceLocatorList::iterator i = list.begin();
122       i != list.end();
123       ++i, ++index) {
124    devs->push_back(Device((*i)->name(), index));
125  }
126  rtc::SoundSystemInterface::ClearSoundDeviceLocatorList(&list);
127  sound_system_.release();
128  return FilterDevices(devs, kFilteredAudioDevicesName);
129}
130
131static const std::string kVideoMetaPathK2_4("/proc/video/dev/");
132static const std::string kVideoMetaPathK2_6("/sys/class/video4linux/");
133
134enum MetaType { M2_4, M2_6, NONE };
135
136static void ScanDeviceDirectory(const std::string& devdir,
137                                std::vector<Device>* devices) {
138  rtc::scoped_ptr<rtc::DirectoryIterator> directoryIterator(
139      rtc::Filesystem::IterateDirectory());
140
141  if (directoryIterator->Iterate(rtc::Pathname(devdir))) {
142    do {
143      std::string filename = directoryIterator->Name();
144      std::string device_name = devdir + filename;
145      if (!directoryIterator->IsDots()) {
146        if (filename.find("video") == 0 &&
147            V4LLookup::IsV4L2Device(device_name)) {
148          devices->push_back(Device(device_name, device_name));
149        }
150      }
151    } while (directoryIterator->Next());
152  }
153}
154
155static std::string GetVideoDeviceNameK2_6(const std::string& device_meta_path) {
156  std::string device_name;
157
158  rtc::scoped_ptr<rtc::FileStream> device_meta_stream(
159      rtc::Filesystem::OpenFile(device_meta_path, "r"));
160
161  if (device_meta_stream) {
162    if (device_meta_stream->ReadLine(&device_name) != rtc::SR_SUCCESS) {
163      LOG(LS_ERROR) << "Failed to read V4L2 device meta " << device_meta_path;
164    }
165    device_meta_stream->Close();
166  }
167
168  return device_name;
169}
170
171static std::string Trim(const std::string& s, const std::string& drop = " \t") {
172  std::string::size_type first = s.find_first_not_of(drop);
173  std::string::size_type last  = s.find_last_not_of(drop);
174
175  if (first == std::string::npos || last == std::string::npos)
176    return std::string("");
177
178  return s.substr(first, last - first + 1);
179}
180
181static std::string GetVideoDeviceNameK2_4(const std::string& device_meta_path) {
182  rtc::ConfigParser::MapVector all_values;
183
184  rtc::ConfigParser config_parser;
185  rtc::FileStream* file_stream =
186      rtc::Filesystem::OpenFile(device_meta_path, "r");
187
188  if (file_stream == NULL) return "";
189
190  config_parser.Attach(file_stream);
191  config_parser.Parse(&all_values);
192
193  for (rtc::ConfigParser::MapVector::iterator i = all_values.begin();
194      i != all_values.end(); ++i) {
195    rtc::ConfigParser::SimpleMap::iterator device_name_i =
196        i->find("name");
197
198    if (device_name_i != i->end()) {
199      return device_name_i->second;
200    }
201  }
202
203  return "";
204}
205
206static std::string GetVideoDeviceName(MetaType meta,
207    const std::string& device_file_name) {
208  std::string device_meta_path;
209  std::string device_name;
210  std::string meta_file_path;
211
212  if (meta == M2_6) {
213    meta_file_path = kVideoMetaPathK2_6 + device_file_name + "/name";
214
215    LOG(LS_INFO) << "Trying " + meta_file_path;
216    device_name = GetVideoDeviceNameK2_6(meta_file_path);
217
218    if (device_name.empty()) {
219      meta_file_path = kVideoMetaPathK2_6 + device_file_name + "/model";
220
221      LOG(LS_INFO) << "Trying " << meta_file_path;
222      device_name = GetVideoDeviceNameK2_6(meta_file_path);
223    }
224  } else {
225    meta_file_path = kVideoMetaPathK2_4 + device_file_name;
226    LOG(LS_INFO) << "Trying " << meta_file_path;
227    device_name = GetVideoDeviceNameK2_4(meta_file_path);
228  }
229
230  if (device_name.empty()) {
231    device_name = "/dev/" + device_file_name;
232    LOG(LS_ERROR)
233      << "Device name not found, defaulting to device path " << device_name;
234  }
235
236  LOG(LS_INFO) << "Name for " << device_file_name << " is " << device_name;
237
238  return Trim(device_name);
239}
240
241static void ScanV4L2Devices(std::vector<Device>* devices) {
242  LOG(LS_INFO) << ("Enumerating V4L2 devices");
243
244  MetaType meta;
245  std::string metadata_dir;
246
247  rtc::scoped_ptr<rtc::DirectoryIterator> directoryIterator(
248      rtc::Filesystem::IterateDirectory());
249
250  // Try and guess kernel version
251  if (directoryIterator->Iterate(kVideoMetaPathK2_6)) {
252    meta = M2_6;
253    metadata_dir = kVideoMetaPathK2_6;
254  } else if (directoryIterator->Iterate(kVideoMetaPathK2_4)) {
255    meta = M2_4;
256    metadata_dir = kVideoMetaPathK2_4;
257  } else {
258    meta = NONE;
259  }
260
261  if (meta != NONE) {
262    LOG(LS_INFO) << "V4L2 device metadata found at " << metadata_dir;
263
264    do {
265      std::string filename = directoryIterator->Name();
266
267      if (filename.find("video") == 0) {
268        std::string device_path = "/dev/" + filename;
269
270        if (V4LLookup::IsV4L2Device(device_path)) {
271          devices->push_back(
272              Device(GetVideoDeviceName(meta, filename), device_path));
273        }
274      }
275    } while (directoryIterator->Next());
276  } else {
277    LOG(LS_ERROR) << "Unable to detect v4l2 metadata directory";
278  }
279
280  if (devices->size() == 0) {
281    LOG(LS_INFO) << "Plan B. Scanning all video devices in /dev directory";
282    ScanDeviceDirectory("/dev/", devices);
283  }
284
285  LOG(LS_INFO) << "Total V4L2 devices found : " << devices->size();
286}
287
288bool LinuxDeviceManager::GetVideoCaptureDevices(std::vector<Device>* devices) {
289  devices->clear();
290  ScanV4L2Devices(devices);
291  return FilterDevices(devices, kFilteredVideoDevicesName);
292}
293
294LinuxDeviceWatcher::LinuxDeviceWatcher(DeviceManagerInterface* dm)
295    : DeviceWatcher(dm),
296      manager_(dm),
297      udev_(NULL),
298      udev_monitor_(NULL),
299      registered_(false) {
300}
301
302LinuxDeviceWatcher::~LinuxDeviceWatcher() {
303}
304
305static rtc::PhysicalSocketServer* CurrentSocketServer() {
306  rtc::SocketServer* ss =
307      rtc::ThreadManager::Instance()->WrapCurrentThread()->socketserver();
308  return reinterpret_cast<rtc::PhysicalSocketServer*>(ss);
309}
310
311bool LinuxDeviceWatcher::Start() {
312  // We deliberately return true in the failure paths here because libudev is
313  // not a critical component of a Linux system so it may not be present/usable,
314  // and we don't want to halt LinuxDeviceManager initialization in such a case.
315  if (!libudev_.Load() || IsWrongLibUDevAbiVersion(libudev_.GetDllHandle())) {
316    LOG(LS_WARNING)
317        << "libudev not present/usable; LinuxDeviceWatcher disabled";
318    return true;
319  }
320  udev_ = libudev_.udev_new()();
321  if (!udev_) {
322    LOG_ERR(LS_ERROR) << "udev_new()";
323    return true;
324  }
325  // The second argument here is the event source. It can be either "kernel" or
326  // "udev", but "udev" is the only correct choice. Apps listen on udev and the
327  // udev daemon in turn listens on the kernel.
328  udev_monitor_ = libudev_.udev_monitor_new_from_netlink()(udev_, "udev");
329  if (!udev_monitor_) {
330    LOG_ERR(LS_ERROR) << "udev_monitor_new_from_netlink()";
331    return true;
332  }
333  // We only listen for changes in the video devices. Audio devices are more or
334  // less unimportant because receiving device change notifications really only
335  // matters for broadcasting updated send/recv capabilities based on whether
336  // there is at least one device available, and almost all computers have at
337  // least one audio device. Also, PulseAudio device notifications don't come
338  // from the udev daemon, they come from the PulseAudio daemon, so we'd only
339  // want to listen for audio device changes from udev if using ALSA. For
340  // simplicity, we don't bother with any audio stuff at all.
341  if (libudev_.udev_monitor_filter_add_match_subsystem_devtype()(
342          udev_monitor_, "video4linux", NULL) < 0) {
343    LOG_ERR(LS_ERROR) << "udev_monitor_filter_add_match_subsystem_devtype()";
344    return true;
345  }
346  if (libudev_.udev_monitor_enable_receiving()(udev_monitor_) < 0) {
347    LOG_ERR(LS_ERROR) << "udev_monitor_enable_receiving()";
348    return true;
349  }
350  CurrentSocketServer()->Add(this);
351  registered_ = true;
352  return true;
353}
354
355void LinuxDeviceWatcher::Stop() {
356  if (registered_) {
357    CurrentSocketServer()->Remove(this);
358    registered_ = false;
359  }
360  if (udev_monitor_) {
361    libudev_.udev_monitor_unref()(udev_monitor_);
362    udev_monitor_ = NULL;
363  }
364  if (udev_) {
365    libudev_.udev_unref()(udev_);
366    udev_ = NULL;
367  }
368  libudev_.Unload();
369}
370
371uint32 LinuxDeviceWatcher::GetRequestedEvents() {
372  return rtc::DE_READ;
373}
374
375void LinuxDeviceWatcher::OnPreEvent(uint32 ff) {
376  // Nothing to do.
377}
378
379void LinuxDeviceWatcher::OnEvent(uint32 ff, int err) {
380  udev_device* device = libudev_.udev_monitor_receive_device()(udev_monitor_);
381  if (!device) {
382    // Probably the socket connection to the udev daemon was terminated (perhaps
383    // the daemon crashed or is being restarted?).
384    LOG_ERR(LS_WARNING) << "udev_monitor_receive_device()";
385    // Stop listening to avoid potential livelock (an fd with EOF in it is
386    // always considered readable).
387    CurrentSocketServer()->Remove(this);
388    registered_ = false;
389    return;
390  }
391  // Else we read the device successfully.
392
393  // Since we already have our own filesystem-based device enumeration code, we
394  // simply re-enumerate rather than inspecting the device event.
395  libudev_.udev_device_unref()(device);
396  manager_->SignalDevicesChange();
397}
398
399int LinuxDeviceWatcher::GetDescriptor() {
400  return libudev_.udev_monitor_get_fd()(udev_monitor_);
401}
402
403bool LinuxDeviceWatcher::IsDescriptorClosed() {
404  // If it is closed then we will just get an error in
405  // udev_monitor_receive_device and unregister, so we don't need to check for
406  // it separately.
407  return false;
408}
409
410};  // namespace cricket
411