check for duplicate destination

libi2pd_client/I2CP.cpp

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2021, The PurpleI2P Project
+* Copyright (c) 2013-2022, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -519,21 +519,26 @@ namespace client
 	void I2CPSession::CreateSessionMessageHandler (const uint8_t * buf, size_t len)
 	{
 		RAND_bytes ((uint8_t *)&m_SessionID, 2);
-		m_Owner.InsertSession (shared_from_this ());
 		auto identity = std::make_shared<i2p::data::IdentityEx>();
 		size_t offset = identity->FromBuffer (buf, len);
 		if (!offset)
 		{
 			LogPrint (eLogError, "I2CP: Create session malformed identity");
-			SendSessionStatusMessage (3); // invalid
+			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
 			return;
 		}
+		if (m_Owner.FindSessionByIdentHash (identity->GetIdentHash ()))
+		{
+			LogPrint (eLogError, "I2CP: Create session duplicate address ", identity->GetIdentHash ().ToBase32 ());
+			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
+			return;
+		}	
 		uint16_t optionsSize = bufbe16toh (buf + offset);
 		offset += 2;
 		if (optionsSize > len - offset)
 		{
 			LogPrint (eLogError, "I2CP: Options size ", optionsSize, "exceeds message size");
-			SendSessionStatusMessage (3); // invalid
+			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
 			return;
 		}
 		std::map<std::string, std::string> params;
@@ -549,33 +554,41 @@ namespace client
 				m_Destination = m_Owner.IsSingleThread () ?
 					std::make_shared<I2CPDestination>(m_Owner.GetService (), shared_from_this (), identity, true, params):
 					std::make_shared<RunnableI2CPDestination>(shared_from_this (), identity, true, params);
-				SendSessionStatusMessage (1); // created
+				if (m_Owner.InsertSession (shared_from_this ()))
-				LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " created");
+				{		
-				m_Destination->Start ();
+					SendSessionStatusMessage (eI2CPSessionStatusCreated); // created
+					LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " created");
+					m_Destination->Start ();
+				}	
+				else
+				{
+					LogPrint (eLogError, "I2CP: Session already exists");
+					SendSessionStatusMessage (eI2CPSessionStatusRefused);
+				}	
 			}
 			else
 			{
 				LogPrint (eLogError, "I2CP: Session already exists");
-				SendSessionStatusMessage (4); // refused
+				SendSessionStatusMessage (eI2CPSessionStatusRefused); // refused
 			}
 		}
 		else
 		{
 			LogPrint (eLogError, "I2CP: Create session signature verification failed");
-			SendSessionStatusMessage (3); // invalid
+			SendSessionStatusMessage (eI2CPSessionStatusInvalid); // invalid
 		}
 	}
 
 	void I2CPSession::DestroySessionMessageHandler (const uint8_t * buf, size_t len)
 	{
-		SendSessionStatusMessage (0); // destroy
+		SendSessionStatusMessage (eI2CPSessionStatusDestroyed); // destroy
 		LogPrint (eLogDebug, "I2CP: Session ", m_SessionID, " destroyed");
 		Terminate ();
 	}
 
 	void I2CPSession::ReconfigureSessionMessageHandler (const uint8_t * buf, size_t len)
 	{
-		uint8_t status = 3; // rejected
+		I2CPSessionStatus status = eI2CPSessionStatusInvalid; // rejected
 		if(len > sizeof(uint16_t))
 		{
 			uint16_t sessionID = bufbe16toh(buf);
@@ -605,7 +618,7 @@ namespace client
 								if(m_Destination->Reconfigure(opts))
 								{
 									LogPrint(eLogInfo, "I2CP: Reconfigured destination");
-									status = 2; // updated
+									status = eI2CPSessionStatusUpdated; // updated
 								}
 								else
 									LogPrint(eLogWarning, "I2CP: Failed to reconfigure destination");
@@ -630,11 +643,11 @@ namespace client
 		SendSessionStatusMessage (status);
 	}
 
-	void I2CPSession::SendSessionStatusMessage (uint8_t status)
+	void I2CPSession::SendSessionStatusMessage (I2CPSessionStatus status)
 	{
 		uint8_t buf[3];
 		htobe16buf (buf, m_SessionID);
-		buf[2] = status;
+		buf[2] = (uint8_t)status;
 		SendI2CPMessage (I2CP_SESSION_STATUS_MESSAGE, buf, 3);
 	}
 
@@ -1009,5 +1022,19 @@ namespace client
 	{
 		m_Sessions.erase (sessionID);
 	}
+
+	std::shared_ptr<I2CPSession> I2CPServer::FindSessionByIdentHash (const i2p::data::IdentHash& ident) const
+	{
+		for (const auto& it: m_Sessions)
+		{
+			if (it.second)
+			{	
+				auto dest = it.second->GetDestination ();
+				if (dest && dest->GetIdentHash () == ident)
+					return it.second;
+			}	
+		}
+		return nullptr;
+	}	
 }
 }

libi2pd_client/I2CP.h

@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2020, The PurpleI2P Project
+* Copyright (c) 2013-2022, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -61,6 +61,15 @@ namespace client
 		eI2CPMessageStatusNoLeaseSet = 21
 	};
 
+	enum I2CPSessionStatus
+	{
+		eI2CPSessionStatusDestroyed = 0,
+		eI2CPSessionStatusCreated = 1,
+		eI2CPSessionStatusUpdated = 2,
+		eI2CPSessionStatusInvalid = 3,
+		eI2CPSessionStatusRefused = 4
+	};
+	
 	// params
 	const char I2CP_PARAM_MESSAGE_RELIABILITY[] = "i2cp.messageReliability";
 
@@ -180,7 +189,7 @@ namespace client
 			std::string ExtractString (const uint8_t * buf, size_t len);
 			size_t PutString (uint8_t * buf, size_t len, const std::string& str);
 			void ExtractMapping (const uint8_t * buf, size_t len, std::map<std::string, std::string>& mapping);
-			void SendSessionStatusMessage (uint8_t status);
+			void SendSessionStatusMessage (I2CPSessionStatus status);
 			void SendHostReplyMessage (uint32_t requestID, std::shared_ptr<const i2p::data::IdentityEx> identity);
 
 		private:
@@ -216,6 +225,7 @@ namespace client
 
 			bool InsertSession (std::shared_ptr<I2CPSession> session);
 			void RemoveSession (uint16_t sessionID);
+			std::shared_ptr<I2CPSession> FindSessionByIdentHash (const i2p::data::IdentHash& ident) const;
 
 		private: