NTCP2 transports through the Yggdrasil

libi2pd/Config.cpp

@@ -276,6 +276,11 @@ namespace config {
 			("cpuext.force", bool_switch()->default_value(false),                    "Force usage of CPU extensions. Useful when cpuinfo is not available on virtual machines")
 		;
 
+		options_description meshnets("Meshnet transports options");
+		meshnets.add_options()
+			("meshnets.yggdrasil", bool_switch()->default_value(false),              "Support transports through the Yggdrasil (deafult: false)")
+		;	
+		
 		m_OptionsDesc
 			.add(general)
 			.add(limits)
@@ -297,6 +302,7 @@ namespace config {
 			.add(nettime)
 			.add(persist)
 			.add(cpuext)
+			.add(meshnets)
 		;
 	}
 

libi2pd/NTCP2.cpp

@@ -1181,7 +1181,7 @@ namespace transport
 							auto conn = std::make_shared<NTCP2Session>(*this);
 							m_NTCP2Acceptor->async_accept(conn->GetSocket (), std::bind (&NTCP2Server::HandleAccept, this, conn, std::placeholders::_1));
 						}
-						else if (address->host.is_v6() && context.SupportsV6 ())
+						else if (address->host.is_v6() && (context.SupportsV6 () || context.SupportsMesh ()))
 						{
 							m_NTCP2V6Acceptor.reset (new boost::asio::ip::tcp::acceptor (GetService ()));
 							try

libi2pd/RouterContext.cpp

@@ -521,6 +521,15 @@ namespace i2p
 		UpdateRouterInfo ();
 	}
 
+	void RouterContext::SetSupportsMesh (bool supportsmesh)
+	{	
+		if (supportsmesh)
+			m_RouterInfo.EnableMesh ();
+		else
+			m_RouterInfo.DisableMesh ();
+		UpdateRouterInfo ();
+	}
+		
 	void RouterContext::UpdateNTCP2V6Address (const boost::asio::ip::address& host)
 	{
 		bool updated = false;

libi2pd/RouterContext.h

@@ -107,8 +107,10 @@ namespace i2p
 			void SetAcceptsTunnels (bool acceptsTunnels) { m_AcceptsTunnels = acceptsTunnels; };
 			bool SupportsV6 () const { return m_RouterInfo.IsV6 (); };
 			bool SupportsV4 () const { return m_RouterInfo.IsV4 (); };
+			bool SupportsMesh () const { return m_RouterInfo.IsMesh (); };
 			void SetSupportsV6 (bool supportsV6);
 			void SetSupportsV4 (bool supportsV4);
+			void SetSupportsMesh (bool supportsmesh);
 			bool IsECIES () const { return GetIdentity ()->GetCryptoKeyType () == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD; };
 			std::unique_ptr<i2p::crypto::NoiseSymmetricState>& GetCurrentNoiseState () { return m_CurrentNoiseState; };
 			

libi2pd/RouterInfo.cpp

@@ -847,6 +847,11 @@ namespace data
 		return m_SupportedTransports & (eSSUV4 | eNTCP2V4);
 	}
 
+	bool RouterInfo::IsMesh () const
+	{
+		return m_SupportedTransports & eNTCP2V6Mesh;
+	}	
+		
 	void RouterInfo::EnableV6 ()
 	{
 		if (!IsV6 ())
@@ -892,6 +897,27 @@ namespace data
 		}
 	}
 
+	void RouterInfo::EnableMesh ()
+	{
+		if (!IsMesh ())
+			m_SupportedTransports |= eNTCP2V6Mesh;
+	}
+		
+	void RouterInfo::DisableMesh ()
+	{		
+		if (IsMesh ())
+		{
+			m_SupportedTransports &= ~eNTCP2V6Mesh;
+			for (auto it = m_Addresses->begin (); it != m_Addresses->end ();)
+			{
+				auto addr = *it;
+				if (i2p::util::net::IsYggdrasilAddress (addr->host))
+					it = m_Addresses->erase (it);
+				else
+					++it;
+			}
+		}	
+	}	
 
 	bool RouterInfo::UsesIntroducer () const
 	{
@@ -958,6 +984,15 @@ namespace data
 			});
 	}	
 
+	std::shared_ptr<const RouterInfo::Address> RouterInfo::GetYggdrasilAddress () const
+	{
+		return GetAddress (
+			[](std::shared_ptr<const RouterInfo::Address> address)->bool
+			{
+				return i2p::util::net::IsYggdrasilAddress (address->host);
+			});
+	}	
+		
 	std::shared_ptr<RouterProfile> RouterInfo::GetProfile () const
 	{
 		if (!m_Profile)

libi2pd/RouterInfo.h

@@ -155,6 +155,7 @@ namespace data
 			std::shared_ptr<const Address> GetPublishedNTCP2V6Address () const; 
 			std::shared_ptr<const Address> GetSSUAddress (bool v4only = true) const;
 			std::shared_ptr<const Address> GetSSUV6Address () const;
+			std::shared_ptr<const Address> GetYggdrasilAddress () const;
 
 			void AddSSUAddress (const char * host, int port, const uint8_t * key, int mtu = 0);
 			void AddNTCP2Address (const uint8_t * staticKey, const uint8_t * iv, const boost::asio::ip::address& host = boost::asio::ip::address(), int port = 0);
@@ -171,10 +172,13 @@ namespace data
 			bool IsNTCP2 (bool v4only = true) const;
 			bool IsV6 () const;
 			bool IsV4 () const;
+			bool IsMesh () const;	
 			void EnableV6 ();
 			void DisableV6 ();
 			void EnableV4 ();
 			void DisableV4 ();
+			void EnableMesh ();
+			void DisableMesh ();	
 			bool IsCompatible (const RouterInfo& other) const { return m_SupportedTransports & other.m_SupportedTransports; };
 			bool HasValidAddresses () const { return m_SupportedTransports; };
 			bool UsesIntroducer () const;

libi2pd/Transports.cpp

@@ -442,13 +442,27 @@ namespace transport
 				if (m_SSUServer && peer.router->IsSSU (!context.SupportsV6 ()))
 				{
 					auto address = peer.router->GetSSUAddress (!context.SupportsV6 ());
-					if (!m_CheckReserved || !i2p::util::net::IsInReservedRange(address->host))
+					if (address && (!m_CheckReserved || !i2p::util::net::IsInReservedRange(address->host)))
 					{
 						m_SSUServer->CreateSession (peer.router, address->host, address->port);
 						return true;
 					}
 				}
 			}
+			if (peer.numAttempts == 3) // Mesh
+			{
+				peer.numAttempts++;
+				if (context.SupportsMesh () && m_NTCP2Server)
+				{
+					auto address = peer.router->GetYggdrasilAddress ();
+					if (address)
+					{
+						auto s = std::make_shared<NTCP2Session> (*m_NTCP2Server, peer.router, address);
+						m_NTCP2Server->Connect (address->host, address->port, s);
+						return true;
+					}	
+				}	
+			}
 			LogPrint (eLogInfo, "Transports: No NTCP or SSU addresses available");
 			i2p::data::netdb.SetUnreachable (ident, true); // we are here because all connection attempts failed
 			peer.Done ();