From 5930e2d221ef3eb09e848ed7a92fb2fa3b692b8b Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Mon, 14 Dec 2015 22:23:28 -0500
Subject: [PATCH] keep pending incoming streams if acceptor is not set

---
 Streaming.cpp | 55 +++++++++++++++++++++++++++++++++++++++++++++++----
 Streaming.h   |  9 +++++++--
 2 files changed, 58 insertions(+), 6 deletions(-)

diff --git a/Streaming.cpp b/Streaming.cpp
index 0b4e514d..deed2adb 100644
--- a/Streaming.cpp
+++ b/Streaming.cpp
@@ -787,7 +787,7 @@ namespace stream
 	}	
 
 	StreamingDestination::StreamingDestination (std::shared_ptr<i2p::client::ClientDestination> owner, uint16_t localPort): 
-		m_Owner (owner), m_LocalPort (localPort) 
+		m_Owner (owner), m_LocalPort (localPort), m_PendingIncomingTimer (m_Owner->GetService ())
 	{
 	}
 		
@@ -802,6 +802,7 @@ namespace stream
 	void StreamingDestination::Stop ()
 	{	
 		ResetAcceptor ();
+		m_PendingIncomingTimer.cancel ();
 		{
 			std::unique_lock<std::mutex> l(m_StreamsMutex);
 			m_Streams.clear ();
@@ -832,8 +833,21 @@ namespace stream
 					m_Acceptor (incomingStream);
 				else
 				{
-					LogPrint ("Acceptor for incoming stream is not set");
-					DeleteStream (incomingStream);
+					LogPrint (eLogInfo, "Acceptor for incoming stream is not set");
+					if (m_PendingIncomingStreams.size () < MAX_PENDING_INCOMING_BACKLOG)
+					{
+						m_PendingIncomingStreams.push_back (incomingStream);
+						m_PendingIncomingTimer.cancel ();
+						m_PendingIncomingTimer.expires_from_now (boost::posix_time::seconds(PENDING_INCOMING_TIMEOUT));
+						m_PendingIncomingTimer.async_wait (std::bind (&StreamingDestination::HandlePendingIncomingTimer, 
+							this, std::placeholders::_1));
+						LogPrint (eLogInfo, "Pending incoming stream added");
+					}
+					else
+					{	
+						LogPrint (eLogError, "Pending incoming streams backlog exceeds ", MAX_PENDING_INCOMING_BACKLOG);
+						incomingStream->Close ();
+					}	
 				}	
 			}	
 			else // follow on packet without SYN
@@ -852,7 +866,7 @@ namespace stream
 			}	
 		}	
 	}	
-
+		
 	std::shared_ptr<Stream> StreamingDestination::CreateNewOutgoingStream (std::shared_ptr<const i2p::data::LeaseSet> remote, int port)
 	{
 		auto s = std::make_shared<Stream> (m_Owner->GetService (), *this, remote, port);
@@ -880,6 +894,39 @@ namespace stream
 		}	
 	}		
 
+	void StreamingDestination::SetAcceptor (const Acceptor& acceptor) 
+	{ 
+		m_Owner->GetService ().post([acceptor, this](void)
+			{                            
+				m_Acceptor = acceptor;
+				for (auto it: m_PendingIncomingStreams)
+					if (it->GetStatus () == eStreamStatusOpen) // still open?
+						m_Acceptor (it);
+				m_PendingIncomingStreams.clear ();
+				m_PendingIncomingTimer.cancel ();
+			});	
+	}
+
+	void StreamingDestination::ResetAcceptor () 
+	{ 
+		m_Owner->GetService ().post([this](void)
+			{                           
+				if (m_Acceptor) m_Acceptor (nullptr); 
+				m_Acceptor = nullptr; 
+			});	
+	}
+
+	void StreamingDestination::HandlePendingIncomingTimer (const boost::system::error_code& ecode)
+	{
+		if (ecode != boost::asio::error::operation_aborted)
+		{
+			LogPrint (eLogInfo, "Pending incoming timeout expired");
+			for (auto it: m_PendingIncomingStreams)
+				it->Close ();
+			m_PendingIncomingStreams.clear ();
+		}	
+	}	
+		
 	void StreamingDestination::HandleDataMessagePayload (const uint8_t * buf, size_t len)
 	{
 		// unzip it
diff --git a/Streaming.h b/Streaming.h
index 580ddf7c..519bda31 100644
--- a/Streaming.h
+++ b/Streaming.h
@@ -49,6 +49,8 @@ namespace stream
 	const int MAX_WINDOW_SIZE = 128;		
 	const int INITIAL_RTT = 8000; // in milliseconds
 	const int INITIAL_RTO = 9000; // in milliseconds
+	const size_t MAX_PENDING_INCOMING_BACKLOG = 128;
+	const int PENDING_INCOMING_TIMEOUT = 10; // in seconds
 	
 	struct Packet
 	{
@@ -201,8 +203,8 @@ namespace stream
 
 			std::shared_ptr<Stream> CreateNewOutgoingStream (std::shared_ptr<const i2p::data::LeaseSet> remote, int port = 0);
 			void DeleteStream (std::shared_ptr<Stream> stream);			
-			void SetAcceptor (const Acceptor& acceptor) { m_Acceptor = acceptor; };
-			void ResetAcceptor () { if (m_Acceptor) m_Acceptor (nullptr); m_Acceptor = nullptr; };
+			void SetAcceptor (const Acceptor& acceptor);
+			void ResetAcceptor ();
 			bool IsAcceptorSet () const { return m_Acceptor != nullptr; };	
 			std::shared_ptr<i2p::client::ClientDestination> GetOwner () const { return m_Owner; };
 			uint16_t GetLocalPort () const { return m_LocalPort; };
@@ -213,6 +215,7 @@ namespace stream
 	
 			void HandleNextPacket (Packet * packet);
 			std::shared_ptr<Stream> CreateNewIncomingStream ();
+			void HandlePendingIncomingTimer (const boost::system::error_code& ecode);
 
 		private:
 
@@ -221,6 +224,8 @@ namespace stream
 			std::mutex m_StreamsMutex;
 			std::map<uint32_t, std::shared_ptr<Stream> > m_Streams;
 			Acceptor m_Acceptor;
+			std::list<std::shared_ptr<Stream> > m_PendingIncomingStreams;
+			boost::asio::deadline_timer m_PendingIncomingTimer;
 			
 		public: