Merge pull request #742 from majestrate/sam-multiaccept

Multiple stream acceptors with SAM

Datagram.cpp

@@ -310,7 +310,7 @@ namespace datagram
 		std::vector<i2p::tunnel::TunnelMessageBlock> send;
 		auto routingPath = GetSharedRoutingPath();
 		// if we don't have a routing path we will drop all queued messages
-		if(routingPath)
+		if(routingPath && routingPath->outboundTunnel && routingPath->remoteLease)
 		{
 			for (const auto & msg : m_SendQueue)
 			{

SAM.cpp

@@ -54,11 +54,7 @@ namespace client
 			case eSAMSocketTypeAcceptor:
 			{
 				if (m_Session)
-				{	
 					m_Session->DelSocket (shared_from_this ());
-					if (m_Session->localDestination)
-						m_Session->localDestination->StopAcceptingStreams ();
-				}
 				break;
 			}
 			default:
@@ -289,6 +285,11 @@ namespace client
 				dest->SetReceiver (std::bind (&SAMSocket::HandleI2PDatagramReceive, shared_from_this (), 
 					std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, std::placeholders::_4, std::placeholders::_5));
 			}
+			else
+			{
+				// start accepting streams because we're not a datagram session
+				m_Session->localDestination->AcceptStreams (std::bind (&SAMSession::AcceptI2P, m_Session, std::placeholders::_1));
+			}
 
 			if (m_Session->localDestination->IsReady ())
 				SendSessionCreateReplyOk ();
@@ -400,21 +401,26 @@ namespace client
 		m_ID = id;
 		m_Session = m_Owner.FindSession (id);
 		if (m_Session)
-		{
-			if (!m_Session->localDestination->IsAcceptingStreams ())
 		{
 			m_SocketType = eSAMSocketTypeAcceptor;
 			m_Session->AddSocket (shared_from_this ());
-				m_Session->localDestination->AcceptStreams (std::bind (&SAMSocket::HandleI2PAccept, shared_from_this (), std::placeholders::_1));
 			SendMessageReply (SAM_STREAM_STATUS_OK, strlen(SAM_STREAM_STATUS_OK), false);
 		}	
-			else
-				SendMessageReply (SAM_STREAM_STATUS_I2P_ERROR, strlen(SAM_STREAM_STATUS_I2P_ERROR), true);
-		}	
 		else
 			SendMessageReply (SAM_STREAM_STATUS_INVALID_ID, strlen(SAM_STREAM_STATUS_INVALID_ID), true);
 	}
 
+	void SAMSocket::Accept(std::shared_ptr<i2p::stream::Stream> stream)
+	{
+		if(stream) {
+			m_SocketType = eSAMSocketTypeStream;
+			HandleI2PAccept(stream);
+		} else {
+			SendMessageReply (SAM_STREAM_STATUS_I2P_ERROR, strlen(SAM_STREAM_STATUS_I2P_ERROR), true);
+			auto s = shared_from_this ();
+			m_Owner.GetService ().post ([s] { s->Terminate (); });
+		}
+	}
 	size_t SAMSocket::ProcessDatagramSend (char * buf, size_t len, const char * data)
 	{
 		LogPrint (eLogDebug, "SAM: datagram send: ", buf, " ", len);
@@ -659,10 +665,6 @@ namespace client
 			LogPrint (eLogDebug, "SAM: incoming I2P connection for session ", m_ID);
 			m_Stream = stream;
 			context.GetAddressBook ().InsertAddress (stream->GetRemoteIdentity ());
-			auto session = m_Owner.FindSession (m_ID);
-			if (session)	
-				session->localDestination->StopAcceptingStreams ();	
-			m_SocketType = eSAMSocketTypeStream;
 			if (!m_IsSilent)
 			{
 				// get remote peer address
@@ -704,26 +706,76 @@ namespace client
 	}
 
 	SAMSession::SAMSession (std::shared_ptr<ClientDestination> dest):
-		localDestination (dest)
+		localDestination (dest),
+		m_BacklogPumper(dest->GetService())
 	{
+		PumpBacklog();
 	}
 
-	SAMSession::~SAMSession ()
+	void SAMSession::AcceptI2P(std::shared_ptr<i2p::stream::Stream> stream)
 	{
-		CloseStreams();
-		i2p::client::context.DeleteLocalDestination (localDestination);
+		if(!stream) return; // fail
+		std::unique_lock<std::mutex> lock(m_SocketsMutex);
+		if(m_Backlog.size() > SAM_MAX_ACCEPT_BACKLOG) {
+			stream->Close();
+			return;
+		}
+		m_Backlog.push_back(stream);
 	}
 
-	void SAMSession::CloseStreams ()
+	void SAMSession::PumpBacklog()
+	{
+		// pump backlog every 100ms
+		boost::posix_time::milliseconds dlt(100);
+		m_BacklogPumper.expires_from_now(dlt);
+		m_BacklogPumper.async_wait(std::bind(&SAMSession::HandlePumpBacklog, this, std::placeholders::_1));
+	}
+
+	std::shared_ptr<SAMSocket> SAMSession::FindAcceptor()
+	{
+		for (auto & sock : m_Sockets) {
+			auto t = sock->GetSocketType();
+			if(t == eSAMSocketTypeAcceptor) {
+				return sock;
+			}
+		}
+		return nullptr;
+	}
+
+	void SAMSession::HandlePumpBacklog(const boost::system::error_code & ec)
 	{
+		if(ec) return;
 		{
+			std::unique_lock<std::mutex> lock(m_SocketsMutex);
+			auto itr = m_Backlog.begin();
+			while(itr != m_Backlog.end()) {
+				auto sock = FindAcceptor();
+				if (sock) {
+					sock->Accept(*itr);
+					itr = m_Backlog.erase(itr);
+				} else {
+					++itr;
+				}
+			}
+		}
+		PumpBacklog();
+	}
+
+	void SAMSession::CloseStreams ()
+	{
+		m_BacklogPumper.cancel();
+		localDestination->GetService().post([&] () {
 			std::lock_guard<std::mutex> lock(m_SocketsMutex);
 			for (auto& sock : m_Sockets) {
 				sock->CloseStream();
 			}
+			for(auto & stream : m_Backlog) {
+				stream->Close();
 			}
-		// XXX: should this be done inside locked parts?
 			m_Sockets.clear();
+			m_Backlog.clear();
+			i2p::client::context.DeleteLocalDestination (localDestination);
+		});
 	}
 
 	SAMBridge::SAMBridge (const std::string& address, int port):
@@ -834,8 +886,9 @@ namespace client
 			auto session = std::make_shared<SAMSession>(localDestination);
 			std::unique_lock<std::mutex> l(m_SessionsMutex);
 			auto ret = m_Sessions.insert (std::make_pair(id, session));
-			if (!ret.second)
+			if (!ret.second) {
 				LogPrint (eLogWarning, "SAM: Session ", id, " already exists");
+			} 
 			return ret.first->second;
 		}
 		return nullptr;

SAM.h

@@ -21,6 +21,7 @@ namespace client
 	const size_t SAM_SOCKET_BUFFER_SIZE = 8192;
 	const int SAM_SOCKET_CONNECTION_MAX_IDLE = 3600; // in seconds
 	const int SAM_SESSION_READINESS_CHECK_INTERVAL = 20; // in seconds
+	const int SAM_MAX_ACCEPT_BACKLOG = 50;
 	const char SAM_HANDSHAKE[] = "HELLO VERSION";
 	const char SAM_HANDSHAKE_REPLY[] = "HELLO REPLY RESULT=OK VERSION=%s\n";
 	const char SAM_HANDSHAKE_I2P_ERROR[] = "HELLO REPLY RESULT=I2P_ERROR\n";	
@@ -84,6 +85,8 @@ namespace client
 			void SetSocketType (SAMSocketType socketType) { m_SocketType = socketType; };
 			SAMSocketType GetSocketType () const { return m_SocketType; };
 
+			void Accept(std::shared_ptr<i2p::stream::Stream> stream);
+
 		private:
 
 			void Terminate ();	
@@ -134,6 +137,8 @@ namespace client
 	struct SAMSession
 	{
 		std::shared_ptr<ClientDestination> localDestination;
+		boost::asio::deadline_timer m_BacklogPumper;
+		std::list<std::shared_ptr<i2p::stream::Stream> > m_Backlog;
 		std::list<std::shared_ptr<SAMSocket> > m_Sockets;
 		std::mutex m_SocketsMutex;
 
@@ -160,7 +165,13 @@ namespace client
 		}
 
 		SAMSession (std::shared_ptr<ClientDestination> dest);
-		~SAMSession ();
+
+		void AcceptI2P(std::shared_ptr<i2p::stream::Stream> stream);
+
+		std::shared_ptr<SAMSocket> FindAcceptor();
+
+		void PumpBacklog();
+		void HandlePumpBacklog(const boost::system::error_code & ec);
 
 		void CloseStreams ();
 	};