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
47 namespace cricket {
48
Create()49 DeviceManagerInterface* DeviceManagerFactory::Create() {
50 return new LinuxDeviceManager();
51 }
52
53 class 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_t GetRequestedEvents();
64 virtual void OnPreEvent(uint32_t ff);
65 virtual void OnEvent(uint32_t 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
76 static 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 };
87 static const char* kFilteredVideoDevicesName[] = {
88 NULL,
89 };
90
LinuxDeviceManager()91 LinuxDeviceManager::LinuxDeviceManager()
92 : sound_system_(new rtc::PlatformSoundSystemFactory()) {
93 set_watcher(new LinuxDeviceWatcher(this));
94 }
95
~LinuxDeviceManager()96 LinuxDeviceManager::~LinuxDeviceManager() {
97 }
98
GetAudioDevices(bool input,std::vector<Device> * devs)99 bool 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
131 static const std::string kVideoMetaPathK2_4("/proc/video/dev/");
132 static const std::string kVideoMetaPathK2_6("/sys/class/video4linux/");
133
134 enum MetaType { M2_4, M2_6, NONE };
135
ScanDeviceDirectory(const std::string & devdir,std::vector<Device> * devices)136 static 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
GetVideoDeviceNameK2_6(const std::string & device_meta_path)155 static 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
Trim(const std::string & s,const std::string & drop=" \\t")171 static 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
GetVideoDeviceNameK2_4(const std::string & device_meta_path)181 static 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
GetVideoDeviceName(MetaType meta,const std::string & device_file_name)206 static 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
ScanV4L2Devices(std::vector<Device> * devices)241 static 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
GetVideoCaptureDevices(std::vector<Device> * devices)288 bool LinuxDeviceManager::GetVideoCaptureDevices(std::vector<Device>* devices) {
289 devices->clear();
290 ScanV4L2Devices(devices);
291 return FilterDevices(devices, kFilteredVideoDevicesName);
292 }
293
LinuxDeviceWatcher(DeviceManagerInterface * dm)294 LinuxDeviceWatcher::LinuxDeviceWatcher(DeviceManagerInterface* dm)
295 : DeviceWatcher(dm),
296 manager_(dm),
297 udev_(NULL),
298 udev_monitor_(NULL),
299 registered_(false) {
300 }
301
~LinuxDeviceWatcher()302 LinuxDeviceWatcher::~LinuxDeviceWatcher() {
303 }
304
CurrentSocketServer()305 static rtc::PhysicalSocketServer* CurrentSocketServer() {
306 rtc::SocketServer* ss =
307 rtc::ThreadManager::Instance()->WrapCurrentThread()->socketserver();
308 return reinterpret_cast<rtc::PhysicalSocketServer*>(ss);
309 }
310
Start()311 bool 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
Stop()355 void 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
GetRequestedEvents()371 uint32_t LinuxDeviceWatcher::GetRequestedEvents() {
372 return rtc::DE_READ;
373 }
374
OnPreEvent(uint32_t ff)375 void LinuxDeviceWatcher::OnPreEvent(uint32_t ff) {
376 // Nothing to do.
377 }
378
OnEvent(uint32_t ff,int err)379 void LinuxDeviceWatcher::OnEvent(uint32_t 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
GetDescriptor()399 int LinuxDeviceWatcher::GetDescriptor() {
400 return libudev_.udev_monitor_get_fd()(udev_monitor_);
401 }
402
IsDescriptorClosed()403 bool 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