aspnetcore/src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs

527 lines
22 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Security.Claims;
using System.Threading;
using System.Threading.Tasks;
using System.Threading.Tasks.Channels;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.SignalR.Internal;
using Microsoft.AspNetCore.SignalR.Internal.Protocol;
using Microsoft.AspNetCore.Sockets;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Internal;
using Microsoft.Extensions.Logging;
namespace Microsoft.AspNetCore.SignalR
{
public class HubEndPoint<THub> : HubEndPoint<THub, IClientProxy> where THub : Hub<IClientProxy>
{
public HubEndPoint(HubLifetimeManager<THub> lifetimeManager,
IHubProtocolResolver protocolResolver,
IHubContext<THub> hubContext,
ILogger<HubEndPoint<THub>> logger,
IServiceScopeFactory serviceScopeFactory)
: base(lifetimeManager, protocolResolver, hubContext, logger, serviceScopeFactory)
{
}
}
public class HubEndPoint<THub, TClient> : IInvocationBinder where THub : Hub<TClient>
{
private readonly Dictionary<string, HubMethodDescriptor> _methods = new Dictionary<string, HubMethodDescriptor>(StringComparer.OrdinalIgnoreCase);
private readonly HubLifetimeManager<THub> _lifetimeManager;
private readonly IHubContext<THub, TClient> _hubContext;
private readonly ILogger<HubEndPoint<THub, TClient>> _logger;
private readonly IServiceScopeFactory _serviceScopeFactory;
private readonly IHubProtocolResolver _protocolResolver;
public HubEndPoint(HubLifetimeManager<THub> lifetimeManager,
IHubProtocolResolver protocolResolver,
IHubContext<THub, TClient> hubContext,
ILogger<HubEndPoint<THub, TClient>> logger,
IServiceScopeFactory serviceScopeFactory)
{
_protocolResolver = protocolResolver;
_lifetimeManager = lifetimeManager;
_hubContext = hubContext;
_logger = logger;
_serviceScopeFactory = serviceScopeFactory;
DiscoverHubMethods();
}
public async Task OnConnectedAsync(ConnectionContext connection)
{
var output = Channel.CreateUnbounded<byte[]>();
var connectionContext = new HubConnectionContext(output, connection);
await ProcessNegotiate(connectionContext);
// Hubs support multiple producers so we set up this loop to copy
// data written to the HubConnectionContext's channel to the transport channel
async Task WriteToTransport()
{
while (await output.In.WaitToReadAsync())
{
while (output.In.TryRead(out var buffer))
{
while (await connection.Transport.Out.WaitToWriteAsync())
{
if (connection.Transport.Out.TryWrite(buffer))
{
break;
}
}
}
}
}
var writingOutputTask = WriteToTransport();
try
{
await _lifetimeManager.OnConnectedAsync(connectionContext);
await RunHubAsync(connectionContext);
}
finally
{
await _lifetimeManager.OnDisconnectedAsync(connectionContext);
// Nothing should be writing to the HubConnectionContext
output.Out.TryComplete();
// This should unwind once we complete the output
await writingOutputTask;
}
}
private async Task ProcessNegotiate(HubConnectionContext connection)
{
while (await connection.Input.WaitToReadAsync())
{
while (connection.Input.TryRead(out var buffer))
{
if (NegotiationProtocol.TryParseMessage(buffer, out var negotiationMessage))
{
// Resolve the Hub Protocol for the connection and store it in metadata
// Other components, outside the Hub, may need to know what protocol is in use
// for a particular connection, so we store it here.
connection.Metadata[HubConnectionMetadataNames.HubProtocol] =
_protocolResolver.GetProtocol(negotiationMessage.Protocol, connection);
return;
}
}
}
}
private async Task RunHubAsync(HubConnectionContext connection)
{
await HubOnConnectedAsync(connection);
try
{
await DispatchMessagesAsync(connection);
}
catch (Exception ex)
{
_logger.LogError(0, ex, "Error when processing requests.");
await HubOnDisconnectedAsync(connection, ex);
throw;
}
await HubOnDisconnectedAsync(connection, null);
}
private async Task HubOnConnectedAsync(HubConnectionContext connection)
{
try
{
using (var scope = _serviceScopeFactory.CreateScope())
{
var hubActivator = scope.ServiceProvider.GetRequiredService<IHubActivator<THub, TClient>>();
var hub = hubActivator.Create();
try
{
InitializeHub(hub, connection);
await hub.OnConnectedAsync();
}
finally
{
hubActivator.Release(hub);
}
}
}
catch (Exception ex)
{
_logger.LogError(0, ex, "Error when invoking OnConnectedAsync on hub.");
throw;
}
}
private async Task HubOnDisconnectedAsync(HubConnectionContext connection, Exception exception)
{
try
{
using (var scope = _serviceScopeFactory.CreateScope())
{
var hubActivator = scope.ServiceProvider.GetRequiredService<IHubActivator<THub, TClient>>();
var hub = hubActivator.Create();
try
{
InitializeHub(hub, connection);
await hub.OnDisconnectedAsync(exception);
}
finally
{
hubActivator.Release(hub);
}
}
}
catch (Exception ex)
{
_logger.LogError(0, ex, "Error when invoking OnDisconnectedAsync on hub.");
throw;
}
}
private async Task DispatchMessagesAsync(HubConnectionContext connection)
{
// We use these for error handling. Since we dispatch multiple hub invocations
// in parallel, we need a way to communicate failure back to the main processing loop. The
// cancellation token is used to stop reading from the channel, the tcs
// is used to get the exception so we can bubble it up the stack
var cts = new CancellationTokenSource();
var completion = new TaskCompletionSource<object>();
var protocol = connection.Metadata.Get<IHubProtocol>(HubConnectionMetadataNames.HubProtocol);
try
{
while (await connection.Input.WaitToReadAsync(cts.Token))
{
while (connection.Input.TryRead(out var buffer))
{
if (protocol.TryParseMessages(buffer, this, out var hubMessages))
{
foreach (var hubMessage in hubMessages)
{
switch (hubMessage)
{
case InvocationMessage invocationMessage:
if (_logger.IsEnabled(LogLevel.Debug))
{
_logger.LogDebug("Received hub invocation: {invocation}", invocationMessage);
}
// Don't wait on the result of execution, continue processing other
// incoming messages on this connection.
var ignore = ProcessInvocation(connection, protocol, invocationMessage, cts, completion);
break;
// Other kind of message we weren't expecting
default:
_logger.LogError("Received unsupported message of type '{messageType}'", hubMessage.GetType().FullName);
throw new NotSupportedException($"Received unsupported message: {hubMessage}");
}
}
}
}
}
}
catch (OperationCanceledException)
{
// Await the task so the exception bubbles up to the caller
await completion.Task;
}
}
private async Task ProcessInvocation(HubConnectionContext connection,
IHubProtocol protocol,
InvocationMessage invocationMessage,
CancellationTokenSource dispatcherCancellation,
TaskCompletionSource<object> dispatcherCompletion)
{
try
{
// If an unexpected exception occurs then we want to kill the entire connection
// by ending the processing loop
await Execute(connection, protocol, invocationMessage);
}
catch (Exception ex)
{
// Set the exception on the task completion source
dispatcherCompletion.TrySetException(ex);
// Cancel reading operation
dispatcherCancellation.Cancel();
}
}
private async Task Execute(HubConnectionContext connection, IHubProtocol protocol, InvocationMessage invocationMessage)
{
if (!_methods.TryGetValue(invocationMessage.Target, out var descriptor))
{
// Send an error to the client. Then let the normal completion process occur
_logger.LogError("Unknown hub method '{method}'", invocationMessage.Target);
await SendMessageAsync(connection, protocol, CompletionMessage.WithError(invocationMessage.InvocationId, $"Unknown hub method '{invocationMessage.Target}'"));
}
else
{
await Invoke(descriptor, connection, protocol, invocationMessage);
}
}
private async Task SendMessageAsync(HubConnectionContext connection, IHubProtocol protocol, HubMessage hubMessage)
{
var payload = protocol.WriteToArray(hubMessage);
while (await connection.Output.WaitToWriteAsync())
{
if (connection.Output.TryWrite(payload))
{
return;
}
}
// Output is closed. Cancel this invocation completely
_logger.LogWarning("Outbound channel was closed while trying to write hub message");
throw new OperationCanceledException("Outbound channel was closed while trying to write hub message");
}
private async Task Invoke(HubMethodDescriptor descriptor, HubConnectionContext connection, IHubProtocol protocol, InvocationMessage invocationMessage)
{
var methodExecutor = descriptor.MethodExecutor;
using (var scope = _serviceScopeFactory.CreateScope())
{
if (!await IsHubMethodAuthorized(scope.ServiceProvider, connection.User, descriptor.Policies))
{
_logger.LogDebug("Failed to invoke {hubMethod} because user is unauthorized", invocationMessage.Target);
if (!invocationMessage.NonBlocking)
{
await SendMessageAsync(connection, protocol, CompletionMessage.WithError(invocationMessage.InvocationId, $"Failed to invoke '{invocationMessage.Target}' because user is unauthorized"));
}
return;
}
var hubActivator = scope.ServiceProvider.GetRequiredService<IHubActivator<THub, TClient>>();
var hub = hubActivator.Create();
try
{
InitializeHub(hub, connection);
object result = null;
// ReadableChannel is awaitable but we don't want to await it.
if (methodExecutor.IsMethodAsync && !IsChannel(methodExecutor.MethodReturnType, out _))
{
if (methodExecutor.MethodReturnType == typeof(Task))
{
await (Task)methodExecutor.Execute(hub, invocationMessage.Arguments);
}
else
{
result = await methodExecutor.ExecuteAsync(hub, invocationMessage.Arguments);
}
}
else
{
result = methodExecutor.Execute(hub, invocationMessage.Arguments);
}
if (IsStreamed(methodExecutor, result, methodExecutor.MethodReturnType, out var enumerator))
{
_logger.LogTrace("[{connectionId}/{invocationId}] Streaming result of type {resultType}", connection.ConnectionId, invocationMessage.InvocationId, methodExecutor.MethodReturnType.FullName);
await StreamResultsAsync(invocationMessage.InvocationId, connection, protocol, enumerator);
}
else if (!invocationMessage.NonBlocking)
{
_logger.LogTrace("[{connectionId}/{invocationId}] Sending result of type {resultType}", connection.ConnectionId, invocationMessage.InvocationId, methodExecutor.MethodReturnType.FullName);
await SendMessageAsync(connection, protocol, CompletionMessage.WithResult(invocationMessage.InvocationId, result));
}
}
catch (TargetInvocationException ex)
{
_logger.LogError(0, ex, "Failed to invoke hub method");
if (!invocationMessage.NonBlocking)
{
await SendMessageAsync(connection, protocol, CompletionMessage.WithError(invocationMessage.InvocationId, ex.InnerException.Message));
}
}
catch (Exception ex)
{
_logger.LogError(0, ex, "Failed to invoke hub method");
if (!invocationMessage.NonBlocking)
{
await SendMessageAsync(connection, protocol, CompletionMessage.WithError(invocationMessage.InvocationId, ex.Message));
}
}
finally
{
hubActivator.Release(hub);
}
}
}
private void InitializeHub(THub hub, HubConnectionContext connection)
{
hub.Clients = _hubContext.Clients;
hub.Context = new HubCallerContext(connection);
hub.Groups = new GroupManager<THub>(_lifetimeManager);
}
private bool IsChannel(Type type, out Type payloadType)
{
var channelType = type.AllBaseTypes().FirstOrDefault(t => t.IsGenericType && t.GetGenericTypeDefinition() == typeof(ReadableChannel<>));
if (channelType == null)
{
payloadType = null;
return false;
}
else
{
payloadType = channelType.GetGenericArguments()[0];
return true;
}
}
private async Task StreamResultsAsync(string invocationId, HubConnectionContext connection, IHubProtocol protocol, IAsyncEnumerator<object> enumerator)
{
// TODO: Cancellation? See https://github.com/aspnet/SignalR/issues/481
try
{
while (await enumerator.MoveNextAsync())
{
// Send the stream item
await SendMessageAsync(connection, protocol, new StreamItemMessage(invocationId, enumerator.Current));
}
await SendMessageAsync(connection, protocol, CompletionMessage.Empty(invocationId));
}
catch (Exception ex)
{
await SendMessageAsync(connection, protocol, CompletionMessage.WithError(invocationId, ex.Message));
}
}
private bool IsStreamed(ObjectMethodExecutor methodExecutor, object result, Type resultType, out IAsyncEnumerator<object> enumerator)
{
if (result == null)
{
enumerator = null;
return false;
}
var observableInterface = IsIObservable(resultType) ?
resultType :
resultType.GetInterfaces().FirstOrDefault(IsIObservable);
if (observableInterface != null)
{
enumerator = AsyncEnumeratorAdapters.FromObservable(result, observableInterface);
return true;
}
else if (IsChannel(resultType, out var payloadType))
{
enumerator = AsyncEnumeratorAdapters.FromChannel(result, payloadType);
return true;
}
else
{
// Not streamed
enumerator = null;
return false;
}
}
private static bool IsIObservable(Type iface)
{
return iface.IsGenericType && iface.GetGenericTypeDefinition() == typeof(IObservable<>);
}
private void DiscoverHubMethods()
{
var hubType = typeof(THub);
var hubTypeInfo = hubType.GetTypeInfo();
foreach (var methodInfo in HubReflectionHelper.GetHubMethods(hubType))
{
var methodName = methodInfo.Name;
if (_methods.ContainsKey(methodName))
{
throw new NotSupportedException($"Duplicate definitions of '{methodName}'. Overloading is not supported.");
}
var executor = ObjectMethodExecutor.Create(methodInfo, hubTypeInfo);
var authorizeAttributes = methodInfo.GetCustomAttributes<AuthorizeAttribute>(inherit: true);
_methods[methodName] = new HubMethodDescriptor(executor, authorizeAttributes);
if (_logger.IsEnabled(LogLevel.Debug))
{
_logger.LogDebug("Hub method '{methodName}' is bound", methodName);
}
}
}
private async Task<bool> IsHubMethodAuthorized(IServiceProvider provider, ClaimsPrincipal principal, IList<IAuthorizeData> policies)
{
// If there are no policies we don't need to run auth
if (!policies.Any())
{
return true;
}
var authService = provider.GetRequiredService<IAuthorizationService>();
var policyProvider = provider.GetRequiredService<IAuthorizationPolicyProvider>();
var authorizePolicy = await AuthorizationPolicy.CombineAsync(policyProvider, policies);
// AuthorizationPolicy.CombineAsync only returns null if there are no policies and we check that above
Debug.Assert(authorizePolicy != null);
var authorizationResult = await authService.AuthorizeAsync(principal, authorizePolicy);
// Only check authorization success, challenge or forbid wouldn't make sense from a hub method invocation
return authorizationResult.Succeeded;
}
Type IInvocationBinder.GetReturnType(string invocationId)
{
return typeof(object);
}
Type[] IInvocationBinder.GetParameterTypes(string methodName)
{
HubMethodDescriptor descriptor;
if (!_methods.TryGetValue(methodName, out descriptor))
{
return Type.EmptyTypes;
}
return descriptor.ParameterTypes;
}
// REVIEW: We can decide to move this out of here if we want pluggable hub discovery
private class HubMethodDescriptor
{
public HubMethodDescriptor(ObjectMethodExecutor methodExecutor, IEnumerable<IAuthorizeData> policies)
{
MethodExecutor = methodExecutor;
ParameterTypes = methodExecutor.MethodParameters.Select(p => p.ParameterType).ToArray();
Policies = policies.ToArray();
}
public ObjectMethodExecutor MethodExecutor { get; }
public Type[] ParameterTypes { get; }
public IList<IAuthorizeData> Policies { get; }
}
}
}