jellyfin/RSSDP/SsdpDevicePublisherBase.cs
2016-10-29 18:22:20 -04:00

725 lines
29 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
namespace Rssdp.Infrastructure
{
/// <summary>
/// Provides the platform independent logic for publishing SSDP devices (notifications and search responses).
/// </summary>
public abstract class SsdpDevicePublisherBase : DisposableManagedObjectBase, ISsdpDevicePublisher
{
#region Fields & Constants
private ISsdpCommunicationsServer _CommsServer;
private string _OSName;
private string _OSVersion;
private bool _SupportPnpRootDevice;
private IList<SsdpRootDevice> _Devices;
private ReadOnlyEnumerable<SsdpRootDevice> _ReadOnlyDevices;
private System.Threading.Timer _RebroadcastAliveNotificationsTimer;
//private TimeSpan _RebroadcastAliveNotificationsTimeSpan;
private DateTime _LastNotificationTime;
private IDictionary<string, SearchRequest> _RecentSearchRequests;
private IUpnpDeviceValidator _DeviceValidator;
private Random _Random;
//private TimeSpan _MinCacheTime;
private const string ServerVersion = "1.0";
#endregion
#region Message Format Constants
#endregion
#region Constructors
/// <summary>
/// Default constructor.
/// </summary>
/// <param name="communicationsServer">The <see cref="ISsdpCommunicationsServer"/> implementation, used to send and receive SSDP network messages.</param>
/// <param name="osName">Then name of the operating system running the server.</param>
/// <param name="osVersion">The version of the operating system running the server.</param>
protected SsdpDevicePublisherBase(ISsdpCommunicationsServer communicationsServer, 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;
_Devices = new List<SsdpRootDevice>();
_ReadOnlyDevices = new ReadOnlyEnumerable<SsdpRootDevice>(_Devices);
_RecentSearchRequests = new Dictionary<string, SearchRequest>(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
/// <summary>
/// Adds a device (and it's children) to the list of devices being published by this server, making them discoverable to SSDP clients.
/// </summary>
/// <remarks>
/// <para>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.</para>
/// <para>Devices added here with a non-zero cache life time will also have notifications broadcast periodically.</para>
/// <para>This method ignores duplicate device adds (if the same device instance is added multiple times, the second and subsequent add calls do nothing).</para>
/// </remarks>
/// <param name="device">The <see cref="SsdpDevice"/> instance to add.</param>
/// <exception cref="System.ArgumentNullException">Thrown if the <paramref name="device"/> argument is null.</exception>
/// <exception cref="System.InvalidOperationException">Thrown if the <paramref name="device"/> contains property values that are not acceptable to the UPnP 1.0 specification.</exception>
[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);
}
}
/// <summary>
/// Removes a device (and it's children) from the list of devices being published by this server, making them undiscoverable.
/// </summary>
/// <remarks>
/// <para>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.</para>
/// <para>This method does nothing if the device was not found in the collection.</para>
/// </remarks>
/// <param name="device">The <see cref="SsdpDevice"/> instance to add.</param>
/// <exception cref="System.ArgumentNullException">Thrown if the <paramref name="device"/> argument is null.</exception>
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
/// <summary>
/// Returns a read only list of devices being published by this instance.
/// </summary>
public IEnumerable<SsdpRootDevice> Devices
{
get
{
return _ReadOnlyDevices;
}
}
/// <summary>
/// If true (default) treats root devices as both upnp:rootdevice and pnp:rootdevice types.
/// </summary>
/// <remarks>
/// <para>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.</para>
/// <para>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.</para>
/// </remarks>
public bool SupportPnpRootDevice
{
get { return _SupportPnpRootDevice; }
set
{
_SupportPnpRootDevice = value;
}
}
#endregion
#region Overrides
/// <summary>
/// Stops listening for requests, stops sending periodic broadcasts, disposes all internal resources.
/// </summary>
/// <param name="disposing"></param>
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, UdpEndPoint endPoint)
{
if (String.IsNullOrEmpty(searchTarget))
{
WriteTrace(String.Format("Invalid search request received From {0}, Target is null/empty.", endPoint.ToString()));
return;
}
WriteTrace(String.Format("Search Request Received From {0}, Target = {1}", endPoint.ToString(), searchTarget));
if (IsDuplicateSearchRequest(searchTarget, endPoint))
{
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<SsdpDevice> 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, endPoint);
}
}
else
WriteTrace(String.Format("Sending 0 search responses."));
});
}
private IEnumerable<SsdpDevice> GetAllDevicesAsFlatEnumerable()
{
return _Devices.Union(_Devices.SelectManyRecursive<SsdpDevice>((d) => d.Devices));
}
private void SendDeviceSearchResponses(SsdpDevice device, UdpEndPoint endPoint)
{
bool isRootDevice = (device as SsdpRootDevice) != null;
if (isRootDevice)
{
SendSearchResponse(SsdpConstants.UpnpDeviceTypeRootDevice, device, GetUsn(device.Udn, SsdpConstants.UpnpDeviceTypeRootDevice), endPoint);
if (this.SupportPnpRootDevice)
SendSearchResponse(SsdpConstants.PnpDeviceTypeRootDevice, device, GetUsn(device.Udn, SsdpConstants.PnpDeviceTypeRootDevice), endPoint);
}
SendSearchResponse(device.Udn, device, device.Udn, endPoint);
SendSearchResponse(device.FullDeviceType, device, GetUsn(device.Udn, device.FullDeviceType), endPoint);
}
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, UdpEndPoint endPoint)
{
var rootDevice = device.ToRootDevice();
//var additionalheaders = FormatCustomHeadersForResponse(device);
const string header = "HTTP/1.1 200 OK";
var values = new Dictionary<string, string>(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 = BuildMessage(header, values);
try
{
await _CommsServer.SendMessage(System.Text.Encoding.UTF8.GetBytes(message), endPoint).ConfigureAwait(false);
}
catch (Exception ex)
{
}
WriteTrace(String.Format("Sent search response to " + endPoint.ToString()), device);
}
private bool IsDuplicateSearchRequest(string searchTarget, UdpEndPoint 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;
}
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1804:RemoveUnusedLocals", MessageId = "t", Justification = "Capturing task to local variable avoids compiler warning, but value is otherwise not required.")]
private void CleanUpRecentSearchRequestsAsync()
{
var t = Task.Run(() =>
{
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<SsdpRootDevice> 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<string, string>(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 = BuildMessage(header, values);
_CommsServer.SendMulticastMessage(System.Text.UTF8Encoding.UTF8.GetBytes(message));
WriteTrace(String.Format("Sent alive notification"), device);
}
private string BuildMessage(string header, Dictionary<string, string> values)
{
var builder = new StringBuilder();
const string argFormat = "{0}: {1}\r\n";
builder.AppendFormat("{0}\r\n", header);
foreach (var pair in values)
{
builder.AppendFormat(argFormat, pair.Key, pair.Value);
}
builder.Append("\r\n");
return builder.ToString();
}
#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<string, string>(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 = BuildMessage(header, values);
return _CommsServer.SendMulticastMessage(System.Text.UTF8Encoding.UTF8.GetBytes(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 = new System.Threading.Timer(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<String> values = null;
if (httpRequestHeaders.TryGetValues(headerName, out values) && values != null)
retVal = values.FirstOrDefault();
return retVal;
}
public static Action<string> 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 (e.Message.Method.Method == SsdpConstants.MSearchMethod)
{
//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);
}
}
#endregion
#region Private Classes
private class SearchRequest
{
public UdpEndPoint 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
}
}