don't create relay response block twice

libi2pd/SSU2OutOfSession.cpp

@@ -227,19 +227,18 @@ namespace transport
 
 	SSU2HolePunchSession::SSU2HolePunchSession (SSU2Server& server, uint32_t nonce,
 		const boost::asio::ip::udp::endpoint& remoteEndpoint,
-		std::shared_ptr<const i2p::data::RouterInfo::Address> localAddr):
+		std::shared_ptr<const i2p::data::RouterInfo::Address> addr):
 		SSU2Session (server), // we create full incoming session
 		m_Nonce (nonce)
 	{
 		// we are Charlie
-		m_Token = GetServer ().GetIncomingToken (remoteEndpoint);
 		uint64_t destConnID = htobe64 (((uint64_t)nonce << 32) | nonce); // dest id
 		uint32_t sourceConnID = ~destConnID;
 		SetSourceConnID (sourceConnID);
 		SetDestConnID (destConnID);	
 		SetState (eSSU2SessionStateHolePunch);
 		SetRemoteEndpoint (remoteEndpoint);
-		SetAddress (localAddr);
+		SetAddress (addr);
 		SetTerminationTimeout (SSU2_RELAY_NONCE_EXPIRATION_TIMEOUT);	
 	}	
 
@@ -267,8 +266,12 @@ namespace transport
 		htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000);
 		size_t payloadSize = 7;
 		payloadSize += CreateAddressBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize, ep);
-		payloadSize += CreateRelayResponseBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize,
-			eSSU2RelayResponseCodeAccept, m_Nonce, m_Token, ep.address ().is_v4 ());
+		// relay response block	
+		if (payloadSize + m_RelayResponseBlock.size () < GetMaxPayloadSize ())
+		{	
+			memcpy (payload + payloadSize, m_RelayResponseBlock.data (), m_RelayResponseBlock.size ());
+			payloadSize += m_RelayResponseBlock.size ();
+		}	
 		payloadSize += CreatePaddingBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize);
 		// encrypt
 		uint8_t n[12];
@@ -282,5 +285,16 @@ namespace transport
 		// send
 		GetServer ().Send (header.buf, 16, h + 16, 16, payload, payloadSize, ep);
 	}	
+
+	void SSU2HolePunchSession::SendHolePunch (const uint8_t * relayResponseBlock, size_t relayResponseBlockLen)
+	{
+#if __cplusplus >= 202002L // C++20
+		m_RelayResponseBlock.assign (relayResponseBlock, relayResponseBlock + relayResponseBlockLen);
+#else		
+		m_RelayResponseBlock.resize (relayResponseBlockLen);
+		memcpy (m_RelayResponseBlock.data (), relayResponseBlock, relayResponseBlockLen);
+#endif		
+		SendHolePunch ();
+	}	
 }
 }

libi2pd/SSU2OutOfSession.h

@@ -57,14 +57,18 @@ namespace transport
 		public:
 
 			SSU2HolePunchSession (SSU2Server& server, uint32_t nonce, const boost::asio::ip::udp::endpoint& remoteEndpoint,
-				std::shared_ptr<const i2p::data::RouterInfo::Address> localAddr);
+				std::shared_ptr<const i2p::data::RouterInfo::Address> addr);
 
+			void SendHolePunch (const uint8_t * relayResponseBlock, size_t relayResponseBlockLen);
+			
+		private:
+			
 			void SendHolePunch ();
 			
 		private:
 
 			uint32_t m_Nonce;
-			uint64_t m_Token; // for RelayResponse block
+			std::vector<uint8_t> m_RelayResponseBlock;
 	};	
 }
 }

libi2pd/SSU2Session.cpp

@@ -1351,46 +1351,6 @@ namespace transport
 		SendSessionRequest (token);
 		return true;
 	}
-
-	void SSU2Session::SendHolePunch (uint32_t nonce, const boost::asio::ip::udp::endpoint& ep,
-		const uint8_t * introKey, uint64_t token)
-	{
-		// we are Charlie
-		LogPrint (eLogDebug, "SSU2: Sending HolePunch to ", ep);
-		Header header;
-		uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE];
-		// fill packet
-		header.h.connID = htobe64 (((uint64_t)nonce << 32) | nonce); // dest id
-		RAND_bytes (header.buf + 8, 4); // random packet num
-		header.h.type = eSSU2HolePunch;
-		header.h.flags[0] = 2; // ver
-		header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
-		header.h.flags[2] = 0; // flag
-		memcpy (h, header.buf, 16);
-		uint64_t c = ~header.h.connID;
-		memcpy (h + 16, &c, 8); // source id
-		RAND_bytes (h + 24, 8); // token
-		// payload
-		payload[0] = eSSU2BlkDateTime;
-		htobe16buf (payload + 1, 4);
-		htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000);
-		size_t payloadSize = 7;
-		payloadSize += CreateAddressBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, ep);
-		payloadSize += CreateRelayResponseBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize,
-			eSSU2RelayResponseCodeAccept, nonce, token, ep.address ().is_v4 ());
-		payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize);
-		// encrypt
-		uint8_t n[12];
-		CreateNonce (be32toh (header.h.packetNum), n);
-		i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, introKey, n, payload, payloadSize + 16, true);
-		payloadSize += 16;
-		header.ll[0] ^= CreateHeaderMask (introKey, payload + (payloadSize - 24));
-		header.ll[1] ^= CreateHeaderMask (introKey, payload + (payloadSize - 12));
-		memset (n, 0, 12);
-		i2p::crypto::ChaCha20 (h + 16, 16, introKey, n, h + 16);
-		// send
-		m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, ep);
-	}
 		
 	bool SSU2Session::ProcessHolePunch (uint8_t * buf, size_t len)
 	{
@@ -1985,8 +1945,8 @@ namespace transport
 	{
 		// we are Charlie
 		SSU2RelayResponseCode code = eSSU2RelayResponseCodeAccept;
-		uint64_t token = 0;
-		bool isV4 = false;
+		boost::asio::ip::udp::endpoint ep;
+		std::shared_ptr<const i2p::data::RouterInfo::Address> addr;
 		auto r = i2p::data::netdb.FindRouter (buf + 1); // Alice
 		if (r)
 		{
@@ -1999,31 +1959,29 @@ namespace transport
 			s.Insert (buf + 47, asz); // Alice Port, Alice IP
 			if (s.Verify (r->GetIdentity (), buf + 47 + asz))
 			{
-				// send HolePunch
-				boost::asio::ip::udp::endpoint ep;
+				// obtain and check endpoint and address for HolePunch
 				if (ExtractEndpoint (buf + 47, asz, ep))
 				{
-					std::shared_ptr<const i2p::data::RouterInfo::Address> addr;
 					if (!ep.address ().is_unspecified () && ep.port ())
-						addr = ep.address ().is_v6 () ? r->GetSSU2V6Address () : r->GetSSU2V4Address ();
-					if (addr)
 					{
 						if (m_Server.IsSupported (ep.address ()))
 						{
-							token = m_Server.GetIncomingToken (ep);
-							isV4 = ep.address ().is_v4 ();
-							SendHolePunch (bufbe32toh (buf + 33), ep, addr->i, token);
-							m_Server.AddConnectedRecently (ep, i2p::util::GetSecondsSinceEpoch ());
+							addr = ep.address ().is_v6 () ? r->GetSSU2V6Address () : r->GetSSU2V4Address ();
+							if (!addr)
+							{
+								LogPrint (eLogWarning, "SSU2: RelayIntro address for endpoint not found");
+								code = eSSU2RelayResponseCodeCharlieAliceIsUnknown;
+							}	
 						}
 						else
 						{
 							LogPrint (eLogWarning, "SSU2: RelayIntro unsupported address");
 							code = eSSU2RelayResponseCodeCharlieUnsupportedAddress;
-						}
+						}	
 					}
 					else
 					{
-						LogPrint (eLogWarning, "SSU2: RelayIntro unknown address");
+						LogPrint (eLogWarning, "SSU2: RelayIntro invalid endpoint");
 						code = eSSU2RelayResponseCodeCharlieAliceIsUnknown;
 					}
 				}
@@ -2059,8 +2017,16 @@ namespace transport
 		}
 		// send relay response to Bob
 		auto packet = m_Server.GetSentPacketsPool ().AcquireShared ();
+		uint32_t nonce = bufbe32toh (buf + 33);
 		packet->payloadSize = CreateRelayResponseBlock (packet->payload, m_MaxPayloadSize,
-			code, bufbe32toh (buf + 33), token, isV4);
+			code, nonce, m_Server.GetIncomingToken (ep), ep.address ().is_v4 ());
+		if (code == eSSU2RelayResponseCodeAccept && addr)
+		{
+			// send HolePunch 
+			auto holePunchSession = std::make_shared<SSU2HolePunchSession>(m_Server, nonce, ep, addr); 
+			m_Server.AddSession (holePunchSession);
+			holePunchSession->SendHolePunch (packet->payload, packet->payloadSize); // relay response block
+		}	
 		packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize);
 		/*uint32_t packetNum = */SendData (packet->payload, packet->payloadSize);
 		// sometimes Bob doesn't ack this RelayResponse

libi2pd/SSU2Session.h

@@ -274,8 +274,6 @@ namespace transport
 			bool ProcessSessionConfirmed (uint8_t * buf, size_t len);
 			bool ProcessRetry (uint8_t * buf, size_t len);
 			bool ProcessHolePunch (uint8_t * buf, size_t len);
-			void SendHolePunch (uint32_t nonce, const boost::asio::ip::udp::endpoint& ep,
-				const uint8_t * introKey, uint64_t token);
 			virtual bool ProcessPeerTest (uint8_t * buf, size_t len);
 			void ProcessData (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& from);
 
@@ -298,8 +296,6 @@ namespace transport
 			size_t CreateAddressBlock (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& ep);
 			size_t CreatePaddingBlock (uint8_t * buf, size_t len, size_t minSize = 0);
 			size_t CreatePeerTestBlock (uint8_t * buf, size_t len, uint8_t msg, SSU2PeerTestCode code, const uint8_t * routerHash, const uint8_t * signedData, size_t signedDataLen);
-
-			size_t CreateRelayResponseBlock (uint8_t * buf, size_t len, SSU2RelayResponseCode code, uint32_t nonce, uint64_t token, bool v4);
 			
 		private:
 
@@ -356,6 +352,8 @@ namespace transport
 			size_t CreateFirstFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage> msg);
 			size_t CreateFollowOnFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage> msg, uint8_t& fragmentNum, uint32_t msgID);
 			size_t CreateRelayIntroBlock (uint8_t * buf, size_t len, const uint8_t * introData, size_t introDataLen);
+			size_t CreateRelayResponseBlock (uint8_t * buf, size_t len, SSU2RelayResponseCode code, uint32_t nonce, uint64_t token, bool v4);
+
 			size_t CreatePeerTestBlock (uint8_t * buf, size_t len, uint32_t nonce); // Alice
 			size_t CreateTerminationBlock (uint8_t * buf, size_t len);