From 8c5111e11a25568befa87e2f107d0f7422de79a7 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Tue, 17 Jul 2018 15:17:05 -0400
Subject: [PATCH] handle NTCP2 I2NP messages

---
 libi2pd/I2NPProtocol.h | 20 ++++++++++++++++++++
 libi2pd/NTCP2.cpp      | 33 ++++++++++++++++++++++++++++++++-
 libi2pd/NTCP2.h        | 12 ++++++++++++
 3 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/libi2pd/I2NPProtocol.h b/libi2pd/I2NPProtocol.h
index f394d284..01b474be 100644
--- a/libi2pd/I2NPProtocol.h
+++ b/libi2pd/I2NPProtocol.h
@@ -26,6 +26,9 @@ namespace i2p
 	const size_t I2NP_SHORT_HEADER_EXPIRATION_OFFSET = I2NP_SHORT_HEADER_TYPEID_OFFSET + 1;
 	const size_t I2NP_SHORT_HEADER_SIZE = I2NP_SHORT_HEADER_EXPIRATION_OFFSET + 4;
 
+	// I2NP NTCP2 header
+	const size_t I2NP_NTCP2_HEADER_SIZE = I2NP_HEADER_EXPIRATION_OFFSET + 4;		
+
 	// Tunnel Gateway header
 	const size_t TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET = 0;
 	const size_t TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET = TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET + 4;
@@ -194,6 +197,23 @@ namespace tunnel
 			len = offset + I2NP_SHORT_HEADER_SIZE + bufbe16toh (header + I2NP_HEADER_SIZE_OFFSET);
 			return bufbe32toh (header + I2NP_HEADER_MSGID_OFFSET);
 		}
+		// for NTCP2 only
+		uint8_t * GetNTCP2Header () { return GetPayload () - I2NP_NTCP2_HEADER_SIZE; };
+		void FromNTCP2 ()
+		{
+			const uint8_t * ntcp2 = GetNTCP2Header ();
+			memcpy (GetHeader () + I2NP_HEADER_TYPEID_OFFSET, ntcp2 + I2NP_HEADER_TYPEID_OFFSET, 5); // typeid + msgid
+			SetExpiration (bufbe32toh (ntcp2 + I2NP_HEADER_EXPIRATION_OFFSET)*1000LL);
+			SetSize (len - offset - I2NP_HEADER_SIZE);
+			SetChks (0);
+		}	
+
+		void ToNTCP2 ()
+		{
+			uint8_t * ntcp2 = GetNTCP2Header ();
+			htobe32buf (ntcp2 + I2NP_HEADER_EXPIRATION_OFFSET, bufbe64toh (GetHeader () + I2NP_HEADER_EXPIRATION_OFFSET)/1000LL);
+			memcpy (ntcp2 + I2NP_HEADER_TYPEID_OFFSET, GetHeader () + I2NP_HEADER_TYPEID_OFFSET, 5); // typeid + msgid
+		}
 
 		void FillI2NPMessageHeader (I2NPMessageType msgType, uint32_t replyMsgID = 0);
 		void RenewI2NPMessageHeader ();
diff --git a/libi2pd/NTCP2.cpp b/libi2pd/NTCP2.cpp
index a5e70c24..3a6aa1c6 100644
--- a/libi2pd/NTCP2.cpp
+++ b/libi2pd/NTCP2.cpp
@@ -167,7 +167,7 @@ namespace transport
 	{
 		m_IsEstablished = true;
 		m_Establisher.reset (nullptr);
-		transports.PeerConnected (shared_from_this ());
+	//	transports.PeerConnected (shared_from_this ());
 	}
 
 	void NTCP2Session::CreateNonce (uint64_t seqn, uint8_t * nonce)
@@ -619,8 +619,39 @@ namespace transport
 				LogPrint (eLogError, "NTCP2: Unexpected block length ", size);
 				break;
 			}
+			switch (blk)
+			{
+				case eNTCP2BlkDateTime:
+					LogPrint (eLogDebug, "NTCP2: datetime");
+				break;	
+				case eNTCP2BlkOptions:
+					LogPrint (eLogDebug, "NTCP2: options");
+				break;
+				case eNTCP2BlkRouterInfo:
+					LogPrint (eLogDebug, "NTCP2: RouterInfo");
+				break;
+				case eNTCP2BlkI2NPMessage:
+				{
+					LogPrint (eLogDebug, "NTCP2: I2NP");
+					auto nextMsg = NewI2NPMessage (size);
+					nextMsg->len = nextMsg->offset + size + 7; // 7 more bytes for full I2NP header
+					memcpy (nextMsg->GetNTCP2Header (), frame + offset, size);
+					nextMsg->FromNTCP2 ();
+					m_Handler.PutNextMessage (nextMsg);	
+					break;
+				}
+				case eNTCP2BlkTermination:
+					LogPrint (eLogDebug, "NTCP2: termination");
+				break;
+				case eNTCP2BlkPadding:
+					LogPrint (eLogDebug, "NTCP2: padding");
+				break;
+				default:
+					LogPrint (eLogWarning, "NTCP2: Unknown block type ", (int)blk);
+			}
 			offset += size;
 		}
+		m_Handler.Flush ();
 	}
 
 	void NTCP2Session::SendNextFrame (const uint8_t * payload, size_t len)
diff --git a/libi2pd/NTCP2.h b/libi2pd/NTCP2.h
index 167b0528..8ce0ba6d 100644
--- a/libi2pd/NTCP2.h
+++ b/libi2pd/NTCP2.h
@@ -13,6 +13,16 @@ namespace i2p
 {
 namespace transport
 {
+	enum NTCP2BlockType
+	{
+		eNTCP2BlkDateTime = 0,
+		eNTCP2BlkOptions, // 1
+		eNTCP2BlkRouterInfo, // 2
+		eNTCP2BlkI2NPMessage, // 3
+		eNTCP2BlkTermination, // 4
+		eNTCP2BlkPadding = 254	
+	};	
+
 	struct NTCP2Establisher
 	{
 		NTCP2Establisher ();
@@ -107,6 +117,8 @@ namespace transport
 			uint8_t * m_NextReceivedBuffer, * m_NextSendBuffer;
 			uint8_t m_ReceiveIV[8], m_SendIV[8];
 			uint64_t m_ReceiveSequenceNumber, m_SendSequenceNumber;
+
+			i2p::I2NPMessagesHandler m_Handler;
 	};
 
 	class NTCP2Server