using System; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Linq; using System.Net.Http; using System.Text; using System.Threading.Tasks; using MediaBrowser.Model.Net; using MediaBrowser.Model.Threading; using RSSDP; namespace Rssdp.Infrastructure { /// /// Provides the platform independent logic for publishing SSDP devices (notifications and search responses). /// public abstract class SsdpDevicePublisherBase : DisposableManagedObjectBase, ISsdpDevicePublisher { #region Fields & Constants private ISsdpCommunicationsServer _CommsServer; private string _OSName; private string _OSVersion; private bool _SupportPnpRootDevice; private IList _Devices; private IReadOnlyList _ReadOnlyDevices; private ITimer _RebroadcastAliveNotificationsTimer; private ITimerFactory _timerFactory; //private TimeSpan _RebroadcastAliveNotificationsTimeSpan; private DateTime _LastNotificationTime; private IDictionary _RecentSearchRequests; private IUpnpDeviceValidator _DeviceValidator; private Random _Random; //private TimeSpan _MinCacheTime; private const string ServerVersion = "1.0"; #endregion #region Message Format Constants #endregion #region Constructors /// /// Default constructor. /// protected SsdpDevicePublisherBase(ISsdpCommunicationsServer communicationsServer, ITimerFactory timerFactory, string osName, string osVersion) { if (communicationsServer == null) throw new ArgumentNullException("communicationsServer"); if (osName == null) throw new ArgumentNullException("osName"); if (osName.Length == 0) throw new ArgumentException("osName cannot be an empty string.", "osName"); if (osVersion == null) throw new ArgumentNullException("osVersion"); if (osVersion.Length == 0) throw new ArgumentException("osVersion cannot be an empty string.", "osName"); _SupportPnpRootDevice = true; _timerFactory = timerFactory; _Devices = new List(); _ReadOnlyDevices = new ReadOnlyCollection(_Devices); _RecentSearchRequests = new Dictionary(StringComparer.OrdinalIgnoreCase); _Random = new Random(); _DeviceValidator = new Upnp10DeviceValidator(); //Should probably inject this later, but for now we only support 1.0. _CommsServer = communicationsServer; _CommsServer.RequestReceived += CommsServer_RequestReceived; _OSName = osName; _OSVersion = osVersion; _CommsServer.BeginListeningForBroadcasts(); } #endregion #region Public Methods /// /// Adds a device (and it's children) to the list of devices being published by this server, making them discoverable to SSDP clients. /// /// /// Adding a device causes "alive" notification messages to be sent immediately, or very soon after. Ensure your device/description service is running before adding the device object here. /// Devices added here with a non-zero cache life time will also have notifications broadcast periodically. /// This method ignores duplicate device adds (if the same device instance is added multiple times, the second and subsequent add calls do nothing). /// /// The instance to add. /// Thrown if the argument is null. /// Thrown if the contains property values that are not acceptable to the UPnP 1.0 specification. [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1804:RemoveUnusedLocals", MessageId = "t", Justification = "Capture task to local variable supresses compiler warning, but task is not really needed.")] public void AddDevice(SsdpRootDevice device) { if (device == null) throw new ArgumentNullException("device"); ThrowIfDisposed(); _DeviceValidator.ThrowIfDeviceInvalid(device); TimeSpan minCacheTime = TimeSpan.Zero; bool wasAdded = false; lock (_Devices) { if (!_Devices.Contains(device)) { _Devices.Add(device); wasAdded = true; minCacheTime = GetMinimumNonZeroCacheLifetime(); } } if (wasAdded) { //_MinCacheTime = minCacheTime; ConnectToDeviceEvents(device); WriteTrace("Device Added", device); SetRebroadcastAliveNotificationsTimer(minCacheTime); SendAliveNotifications(device, true); } } /// /// Removes a device (and it's children) from the list of devices being published by this server, making them undiscoverable. /// /// /// Removing a device causes "byebye" notification messages to be sent immediately, advising clients of the device/service becoming unavailable. We recommend removing the device from the published list before shutting down the actual device/service, if possible. /// This method does nothing if the device was not found in the collection. /// /// The instance to add. /// Thrown if the argument is null. public async Task RemoveDevice(SsdpRootDevice device) { if (device == null) throw new ArgumentNullException("device"); ThrowIfDisposed(); bool wasRemoved = false; TimeSpan minCacheTime = TimeSpan.Zero; lock (_Devices) { if (_Devices.Contains(device)) { _Devices.Remove(device); wasRemoved = true; minCacheTime = GetMinimumNonZeroCacheLifetime(); } } if (wasRemoved) { //_MinCacheTime = minCacheTime; DisconnectFromDeviceEvents(device); WriteTrace("Device Removed", device); await SendByeByeNotifications(device, true).ConfigureAwait(false); SetRebroadcastAliveNotificationsTimer(minCacheTime); } } #endregion #region Public Properties /// /// Returns a read only list of devices being published by this instance. /// public IEnumerable Devices { get { return _ReadOnlyDevices; } } /// /// If true (default) treats root devices as both upnp:rootdevice and pnp:rootdevice types. /// /// /// Enabling this option will cause devices to show up in Microsoft Windows Explorer's network screens (if discovery is enabled etc.). Windows Explorer appears to search only for pnp:rootdeivce and not upnp:rootdevice. /// If false, the system will only use upnp:rootdevice for notifiation broadcasts and and search responses, which is correct according to the UPnP/SSDP spec. /// public bool SupportPnpRootDevice { get { return _SupportPnpRootDevice; } set { _SupportPnpRootDevice = value; } } #endregion #region Overrides /// /// Stops listening for requests, stops sending periodic broadcasts, disposes all internal resources. /// /// protected override void Dispose(bool disposing) { if (disposing) { var commsServer = _CommsServer; _CommsServer = null; if (commsServer != null) { commsServer.RequestReceived -= this.CommsServer_RequestReceived; if (!commsServer.IsShared) commsServer.Dispose(); } DisposeRebroadcastTimer(); foreach (var device in this.Devices) { DisconnectFromDeviceEvents(device); } _RecentSearchRequests = null; } } #endregion #region Private Methods #region Search Related Methods private void ProcessSearchRequest(string mx, string searchTarget, IpEndPointInfo remoteEndPoint, IpAddressInfo receivedOnlocalIpAddress) { if (String.IsNullOrEmpty(searchTarget)) { WriteTrace(String.Format("Invalid search request received From {0}, Target is null/empty.", remoteEndPoint.ToString())); return; } WriteTrace(String.Format("Search Request Received From {0}, Target = {1}", remoteEndPoint.ToString(), searchTarget)); if (IsDuplicateSearchRequest(searchTarget, remoteEndPoint)) { //WriteTrace("Search Request is Duplicate, ignoring."); return; } //Wait on random interval up to MX, as per SSDP spec. //Also, as per UPnP 1.1/SSDP spec ignore missing/bank MX header. If over 120, assume random value between 0 and 120. //Using 16 as minimum as that's often the minimum system clock frequency anyway. int maxWaitInterval = 0; if (String.IsNullOrEmpty(mx)) { //Windows Explorer is poorly behaved and doesn't supply an MX header value. //if (this.SupportPnpRootDevice) mx = "1"; //else //return; } if (!Int32.TryParse(mx, out maxWaitInterval) || maxWaitInterval <= 0) return; if (maxWaitInterval > 120) maxWaitInterval = _Random.Next(0, 120); //Do not block synchronously as that may tie up a threadpool thread for several seconds. Task.Delay(_Random.Next(16, (maxWaitInterval * 1000))).ContinueWith((parentTask) => { //Copying devices to local array here to avoid threading issues/enumerator exceptions. IEnumerable devices = null; lock (_Devices) { if (String.Compare(SsdpConstants.SsdpDiscoverAllSTHeader, searchTarget, StringComparison.OrdinalIgnoreCase) == 0) devices = GetAllDevicesAsFlatEnumerable().ToArray(); else if (String.Compare(SsdpConstants.UpnpDeviceTypeRootDevice, searchTarget, StringComparison.OrdinalIgnoreCase) == 0 || (this.SupportPnpRootDevice && String.Compare(SsdpConstants.PnpDeviceTypeRootDevice, searchTarget, StringComparison.OrdinalIgnoreCase) == 0)) devices = _Devices.ToArray(); else if (searchTarget.Trim().StartsWith("uuid:", StringComparison.OrdinalIgnoreCase)) devices = (from device in GetAllDevicesAsFlatEnumerable() where String.Compare(device.Uuid, searchTarget.Substring(5), StringComparison.OrdinalIgnoreCase) == 0 select device).ToArray(); else if (searchTarget.StartsWith("urn:", StringComparison.OrdinalIgnoreCase)) devices = (from device in GetAllDevicesAsFlatEnumerable() where String.Compare(device.FullDeviceType, searchTarget, StringComparison.OrdinalIgnoreCase) == 0 select device).ToArray(); } if (devices != null) { var deviceList = devices.ToList(); //WriteTrace(String.Format("Sending {0} search responses", deviceList.Count)); foreach (var device in deviceList) { SendDeviceSearchResponses(device, remoteEndPoint, receivedOnlocalIpAddress); } } else { //WriteTrace(String.Format("Sending 0 search responses.")); } }); } private IEnumerable GetAllDevicesAsFlatEnumerable() { return _Devices.Union(_Devices.SelectManyRecursive((d) => d.Devices)); } private void SendDeviceSearchResponses(SsdpDevice device, IpEndPointInfo endPoint, IpAddressInfo receivedOnlocalIpAddress) { bool isRootDevice = (device as SsdpRootDevice) != null; if (isRootDevice) { SendSearchResponse(SsdpConstants.UpnpDeviceTypeRootDevice, device, GetUsn(device.Udn, SsdpConstants.UpnpDeviceTypeRootDevice), endPoint, receivedOnlocalIpAddress); if (this.SupportPnpRootDevice) SendSearchResponse(SsdpConstants.PnpDeviceTypeRootDevice, device, GetUsn(device.Udn, SsdpConstants.PnpDeviceTypeRootDevice), endPoint, receivedOnlocalIpAddress); } SendSearchResponse(device.Udn, device, device.Udn, endPoint, receivedOnlocalIpAddress); SendSearchResponse(device.FullDeviceType, device, GetUsn(device.Udn, device.FullDeviceType), endPoint, receivedOnlocalIpAddress); } private static string GetUsn(string udn, string fullDeviceType) { return String.Format("{0}::{1}", udn, fullDeviceType); } private async void SendSearchResponse(string searchTarget, SsdpDevice device, string uniqueServiceName, IpEndPointInfo endPoint, IpAddressInfo receivedOnlocalIpAddress) { var rootDevice = device.ToRootDevice(); //var additionalheaders = FormatCustomHeadersForResponse(device); const string header = "HTTP/1.1 200 OK"; var values = new Dictionary(StringComparer.OrdinalIgnoreCase); values["EXT"] = ""; values["DATE"] = DateTime.UtcNow.ToString("r"); values["CACHE-CONTROL"] = "max-age = 600"; values["ST"] = searchTarget; values["SERVER"] = string.Format("{0}/{1} UPnP/1.0 RSSDP/{2}", _OSName, _OSVersion, ServerVersion); values["USN"] = uniqueServiceName; values["LOCATION"] = rootDevice.Location.ToString(); var message = SsdpHelper.BuildMessage(header, values); try { await _CommsServer.SendMessage(System.Text.Encoding.UTF8.GetBytes(message), endPoint, receivedOnlocalIpAddress).ConfigureAwait(false); } catch (Exception ex) { } //WriteTrace(String.Format("Sent search response to " + endPoint.ToString()), device); } private bool IsDuplicateSearchRequest(string searchTarget, IpEndPointInfo endPoint) { var isDuplicateRequest = false; var newRequest = new SearchRequest() { EndPoint = endPoint, SearchTarget = searchTarget, Received = DateTime.UtcNow }; lock (_RecentSearchRequests) { if (_RecentSearchRequests.ContainsKey(newRequest.Key)) { var lastRequest = _RecentSearchRequests[newRequest.Key]; if (lastRequest.IsOld()) _RecentSearchRequests[newRequest.Key] = newRequest; else isDuplicateRequest = true; } else { _RecentSearchRequests.Add(newRequest.Key, newRequest); if (_RecentSearchRequests.Count > 10) CleanUpRecentSearchRequestsAsync(); } } return isDuplicateRequest; } private void CleanUpRecentSearchRequestsAsync() { lock (_RecentSearchRequests) { foreach (var requestKey in (from r in _RecentSearchRequests where r.Value.IsOld() select r.Key).ToArray()) { _RecentSearchRequests.Remove(requestKey); } } } #endregion #region Notification Related Methods #region Alive private void SendAllAliveNotifications(object state) { try { if (IsDisposed) return; //DisposeRebroadcastTimer(); //WriteTrace("Begin Sending Alive Notifications For All Devices"); _LastNotificationTime = DateTime.Now; IEnumerable devices; lock (_Devices) { devices = _Devices.ToArray(); } foreach (var device in devices) { if (IsDisposed) return; SendAliveNotifications(device, true); } //WriteTrace("Completed Sending Alive Notifications For All Devices"); } catch (ObjectDisposedException ex) { WriteTrace("Publisher stopped, exception " + ex.Message); Dispose(); } //finally //{ // // This is causing all notifications to stop // //if (!this.IsDisposed) // //SetRebroadcastAliveNotificationsTimer(_MinCacheTime); //} } private void SendAliveNotifications(SsdpDevice device, bool isRoot) { if (isRoot) { SendAliveNotification(device, SsdpConstants.UpnpDeviceTypeRootDevice, GetUsn(device.Udn, SsdpConstants.UpnpDeviceTypeRootDevice)); if (this.SupportPnpRootDevice) SendAliveNotification(device, SsdpConstants.PnpDeviceTypeRootDevice, GetUsn(device.Udn, SsdpConstants.PnpDeviceTypeRootDevice)); } SendAliveNotification(device, device.Udn, device.Udn); SendAliveNotification(device, device.FullDeviceType, GetUsn(device.Udn, device.FullDeviceType)); foreach (var childDevice in device.Devices) { SendAliveNotifications(childDevice, false); } } private void SendAliveNotification(SsdpDevice device, string notificationType, string uniqueServiceName) { var rootDevice = device.ToRootDevice(); const string header = "NOTIFY * HTTP/1.1"; var values = new Dictionary(StringComparer.OrdinalIgnoreCase); // If needed later for non-server devices, these headers will need to be dynamic values["HOST"] = "239.255.255.250:1900"; values["DATE"] = DateTime.UtcNow.ToString("r"); values["CACHE-CONTROL"] = "max-age = " + rootDevice.CacheLifetime.TotalSeconds; values["LOCATION"] = rootDevice.Location.ToString(); values["SERVER"] = string.Format("{0}/{1} UPnP/1.0 RSSDP/{2}", _OSName, _OSVersion, ServerVersion); values["NTS"] = "ssdp:alive"; values["NT"] = notificationType; values["USN"] = uniqueServiceName; var message = SsdpHelper.BuildMessage(header, values); _CommsServer.SendMulticastMessage(message); //WriteTrace(String.Format("Sent alive notification"), device); } #endregion #region ByeBye private async Task SendByeByeNotifications(SsdpDevice device, bool isRoot) { if (isRoot) { await SendByeByeNotification(device, SsdpConstants.UpnpDeviceTypeRootDevice, GetUsn(device.Udn, SsdpConstants.UpnpDeviceTypeRootDevice)).ConfigureAwait(false); if (this.SupportPnpRootDevice) await SendByeByeNotification(device, "pnp:rootdevice", GetUsn(device.Udn, "pnp:rootdevice")).ConfigureAwait(false); ; } await SendByeByeNotification(device, device.Udn, device.Udn).ConfigureAwait(false); ; await SendByeByeNotification(device, String.Format("urn:{0}", device.FullDeviceType), GetUsn(device.Udn, device.FullDeviceType)).ConfigureAwait(false); ; foreach (var childDevice in device.Devices) { await SendByeByeNotifications(childDevice, false).ConfigureAwait(false); ; } } [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA2204:Literals should be spelled correctly", MessageId = "byebye", Justification = "Correct value for this type of notification in SSDP.")] private Task SendByeByeNotification(SsdpDevice device, string notificationType, string uniqueServiceName) { const string header = "NOTIFY * HTTP/1.1"; var values = new Dictionary(StringComparer.OrdinalIgnoreCase); // If needed later for non-server devices, these headers will need to be dynamic values["HOST"] = "239.255.255.250:1900"; values["DATE"] = DateTime.UtcNow.ToString("r"); values["SERVER"] = string.Format("{0}/{1} UPnP/1.0 RSSDP/{2}", _OSName, _OSVersion, ServerVersion); values["NTS"] = "ssdp:byebye"; values["NT"] = notificationType; values["USN"] = uniqueServiceName; var message = SsdpHelper.BuildMessage(header, values); return _CommsServer.SendMulticastMessage(message); //WriteTrace(String.Format("Sent byebye notification"), device); } #endregion #region Rebroadcast Timer private void DisposeRebroadcastTimer() { var timer = _RebroadcastAliveNotificationsTimer; _RebroadcastAliveNotificationsTimer = null; if (timer != null) timer.Dispose(); } private void SetRebroadcastAliveNotificationsTimer(TimeSpan minCacheTime) { //if (minCacheTime == _RebroadcastAliveNotificationsTimeSpan) return; DisposeRebroadcastTimer(); if (minCacheTime == TimeSpan.Zero) return; // According to UPnP/SSDP spec, we should randomise the interval at // which we broadcast notifications, to help with network congestion. // Specs also advise to choose a random interval up to *half* the cache time. // Here we do that, but using the minimum non-zero cache time of any device we are publishing. var rebroadCastInterval = new TimeSpan(minCacheTime.Ticks); // If we were already setup to rebroadcast someime in the future, // don't just blindly reset the next broadcast time to the new interval // as repeatedly changing the interval might end up causing us to over // delay in sending the next one. var nextBroadcastInterval = rebroadCastInterval; if (_LastNotificationTime != DateTime.MinValue) { nextBroadcastInterval = rebroadCastInterval.Subtract(DateTime.Now.Subtract(_LastNotificationTime)); if (nextBroadcastInterval.Ticks < 0) nextBroadcastInterval = TimeSpan.Zero; else if (nextBroadcastInterval > rebroadCastInterval) nextBroadcastInterval = rebroadCastInterval; } //_RebroadcastAliveNotificationsTimeSpan = rebroadCastInterval; _RebroadcastAliveNotificationsTimer = _timerFactory.Create(SendAllAliveNotifications, null, nextBroadcastInterval, rebroadCastInterval); WriteTrace(String.Format("Rebroadcast Interval = {0}, Next Broadcast At = {1}", rebroadCastInterval.ToString(), nextBroadcastInterval.ToString())); } private TimeSpan GetMinimumNonZeroCacheLifetime() { var nonzeroCacheLifetimesQuery = (from device in _Devices where device.CacheLifetime != TimeSpan.Zero select device.CacheLifetime).ToList(); if (nonzeroCacheLifetimesQuery.Any()) return nonzeroCacheLifetimesQuery.Min(); else return TimeSpan.Zero; } #endregion #endregion private static string GetFirstHeaderValue(System.Net.Http.Headers.HttpRequestHeaders httpRequestHeaders, string headerName) { string retVal = null; IEnumerable values = null; if (httpRequestHeaders.TryGetValues(headerName, out values) && values != null) retVal = values.FirstOrDefault(); return retVal; } public static Action LogFunction { get; set; } private static void WriteTrace(string text) { if (LogFunction != null) { LogFunction(text); } //System.Diagnostics.Debug.WriteLine(text, "SSDP Publisher"); } private static void WriteTrace(string text, SsdpDevice device) { var rootDevice = device as SsdpRootDevice; if (rootDevice != null) WriteTrace(text + " " + device.DeviceType + " - " + device.Uuid + " - " + rootDevice.Location); else WriteTrace(text + " " + device.DeviceType + " - " + device.Uuid); } private void ConnectToDeviceEvents(SsdpDevice device) { device.DeviceAdded += device_DeviceAdded; device.DeviceRemoved += device_DeviceRemoved; foreach (var childDevice in device.Devices) { ConnectToDeviceEvents(childDevice); } } private void DisconnectFromDeviceEvents(SsdpDevice device) { device.DeviceAdded -= device_DeviceAdded; device.DeviceRemoved -= device_DeviceRemoved; foreach (var childDevice in device.Devices) { DisconnectFromDeviceEvents(childDevice); } } #endregion #region Event Handlers private void device_DeviceAdded(object sender, DeviceEventArgs e) { SendAliveNotifications(e.Device, false); ConnectToDeviceEvents(e.Device); } private void device_DeviceRemoved(object sender, DeviceEventArgs e) { var task = SendByeByeNotifications(e.Device, false); Task.WaitAll(task); DisconnectFromDeviceEvents(e.Device); } private void CommsServer_RequestReceived(object sender, RequestReceivedEventArgs e) { if (this.IsDisposed) return; if (string.Equals(e.Message.Method.Method, SsdpConstants.MSearchMethod, StringComparison.OrdinalIgnoreCase)) { //According to SSDP/UPnP spec, ignore message if missing these headers. // Edit: But some devices do it anyway //if (!e.Message.Headers.Contains("MX")) // WriteTrace("Ignoring search request - missing MX header."); //else if (!e.Message.Headers.Contains("MAN")) // WriteTrace("Ignoring search request - missing MAN header."); //else ProcessSearchRequest(GetFirstHeaderValue(e.Message.Headers, "MX"), GetFirstHeaderValue(e.Message.Headers, "ST"), e.ReceivedFrom, e.LocalIpAddress); } } #endregion #region Private Classes private class SearchRequest { public IpEndPointInfo EndPoint { get; set; } public DateTime Received { get; set; } public string SearchTarget { get; set; } public string Key { get { return this.SearchTarget + ":" + this.EndPoint.ToString(); } } public bool IsOld() { return DateTime.UtcNow.Subtract(this.Received).TotalMilliseconds > 500; } } #endregion } }