public void MutateIncoming(TransportMessage transportMessage)
{
var messageTypeString = GetSubscriptionMessageTypeFrom(transportMessage);
var intent = transportMessage.MessageIntent;
if (string.IsNullOrEmpty(messageTypeString) && intent != MessageIntentEnum.Subscribe && intent != MessageIntentEnum.Unsubscribe)
{
return;
}
if (string.IsNullOrEmpty(messageTypeString))
{
throw new InvalidOperationException("Message intent is Subscribe, but the subscription message type header is missing!");
}
if (intent != MessageIntentEnum.Subscribe && intent != MessageIntentEnum.Unsubscribe)
{
throw new InvalidOperationException("Subscription messages need to have intent set to Subscribe/Unsubscribe");
}
var subscriberAddress = transportMessage.ReplyToAddress;
if (subscriberAddress == null || subscriberAddress == Address.Undefined)
{
throw new InvalidOperationException("Subscription message arrived without a valid ReplyToAddress");
}
if (SubscriptionStorage == null)
{
var warning = string.Format("Subscription message from {0} arrived at this endpoint, yet this endpoint is not configured to be a publisher. To avoid this warning make this endpoint a publisher by configuring a subscription storage or using the AsA_Publisher role.", subscriberAddress);
Logger.WarnFormat(warning);
if (Debugger.IsAttached) // only under debug, so that we don't expose ourselves to a denial of service
{
throw new InvalidOperationException(warning); // and cause message to go to error queue by throwing an exception
}
return;
}
//service locate to avoid a circular dependency
Builder.Build <IBus>().DoNotContinueDispatchingCurrentMessageToHandlers();
if (transportMessage.MessageIntent == MessageIntentEnum.Subscribe)
{
if (!SubscriptionAuthorizer.AuthorizeSubscribe(messageTypeString, subscriberAddress.ToString(), transportMessage.Headers))
{
Logger.Debug(string.Format("Subscription request from {0} on message type {1} was refused.", subscriberAddress, messageTypeString));
}
else
{
Logger.Info("Subscribing " + subscriberAddress + " to message type " + messageTypeString);
var mt = new MessageType(messageTypeString);
SubscriptionStorage.Subscribe(transportMessage.ReplyToAddress, new[] { mt });
if (ClientSubscribed != null)
{
ClientSubscribed(this, new SubscriptionEventArgs
{
MessageType = messageTypeString,
SubscriberReturnAddress = subscriberAddress
});
}
}
return;
}
if (!SubscriptionAuthorizer.AuthorizeUnsubscribe(messageTypeString, subscriberAddress.ToString(), transportMessage.Headers))
{
Logger.Debug(string.Format("Unsubscribe request from {0} on message type {1} was refused.", subscriberAddress, messageTypeString));
return;
}
Logger.Info("Unsubscribing " + subscriberAddress + " from message type " + messageTypeString);
SubscriptionStorage.Unsubscribe(subscriberAddress, new[] { new MessageType(messageTypeString) });
}
/// <summary>
/// Set a <see cref="SubscriptionAuthorizer"/> to be used when verifying a <see cref="MessageIntentEnum.Subscribe"/> or <see cref="MessageIntentEnum.Unsubscribe"/> message.
/// </summary>
/// <remarks>This is a "single instance" extension point. So calling this api multiple time will result in only the last one added being executed at message receive time.</remarks>
/// <param name="transportExtensions">The <see cref="TransportExtensions"/> to extend.</param>
/// <param name="authorizer">The <see cref="SubscriptionAuthorizer"/> to execute.</param>
public static void SubscriptionAuthorizer(this TransportExtensions transportExtensions, SubscriptionAuthorizer authorizer)
{
Guard.AgainstNull(nameof(authorizer), authorizer);
var settings = transportExtensions.Settings;
var transport = settings.Get <TransportDefinition>();
if (transport.GetOutboundRoutingPolicy(settings).Publishes == OutboundRoutingType.Multicast)
{
var message = $"The transport {transport.GetType().Name} supports native publish-subscribe so subscriptions are not managed by the transport in the publishing endpoint. Use the native transport tools managing subscritions.";
throw new ArgumentException(message, nameof(authorizer));
}
settings.Set <SubscriptionAuthorizer>(authorizer);
}
