From 6caec6b551a704e31d49e40f5add84a739c9e00b Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Thu, 13 Jun 2024 18:10:45 -0400
Subject: [PATCH] check if updated router is still introducer. Remove
 non-introducer sessions from introducers list

---
 libi2pd/SSU2.cpp        | 29 ++++++++++++++---------------
 libi2pd/SSU2Session.cpp | 35 ++++++++++++++++++++++++++++-------
 libi2pd/SSU2Session.h   |  1 +
 3 files changed, 43 insertions(+), 22 deletions(-)

diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp
index 107c5ef7..ab1a7d8b 100644
--- a/libi2pd/SSU2.cpp
+++ b/libi2pd/SSU2.cpp
@@ -1104,22 +1104,21 @@ namespace transport
 				session = it1->second;
 				excluded.insert (it);
 			}
-			if (session && session->IsEstablished () && session->GetRelayTag () && session->IsOutgoing ()) // still session with introducer?
-			{
-				if (ts < session->GetCreationTime () + SSU2_TO_INTRODUCER_SESSION_EXPIRATION)
+			if (session && session->IsEstablished () && session->GetRelayTag () && session->IsOutgoing () && // still session with introducer?
+				ts < session->GetCreationTime () + SSU2_TO_INTRODUCER_SESSION_EXPIRATION)
+			{	
+				session->SendKeepAlive ();
+				if (ts < session->GetCreationTime () + SSU2_TO_INTRODUCER_SESSION_DURATION)	
+					newList.push_back (it);
+				else	
 				{	
-					session->SendKeepAlive ();
-					if (ts < session->GetCreationTime () + SSU2_TO_INTRODUCER_SESSION_DURATION)	
-						newList.push_back (it);
-					else	
-					{	
-						impliedList.push_back (it); // keep in introducers list, but not publish
-						session = nullptr;	
-					}		
-				}	
-				else
-					session = nullptr;
-			}
+					impliedList.push_back (it); // keep in introducers list, but not publish
+					session = nullptr;	
+				}		
+			}	
+			else
+				session = nullptr;
+			
 			if (!session)
 				i2p::context.RemoveSSU2Introducer (it, v4);
 		}
diff --git a/libi2pd/SSU2Session.cpp b/libi2pd/SSU2Session.cpp
index a0adb5f3..51e328b6 100644
--- a/libi2pd/SSU2Session.cpp
+++ b/libi2pd/SSU2Session.cpp
@@ -1575,14 +1575,9 @@ namespace transport
 					LogPrint (eLogDebug, "SSU2: Options");
 				break;
 				case eSSU2BlkRouterInfo:
-				{
-					// not from SessionConfirmed, we must add it instantly to use in next block
 					LogPrint (eLogDebug, "SSU2: RouterInfo");
-					auto ri = ExtractRouterInfo (buf + offset, size);
-					if (ri)
-						i2p::data::netdb.AddRouterInfo (ri->GetBuffer (), ri->GetBufferLen ());	// TODO: add ri
-					break;
-				}
+					HandleRouterInfo (buf + offset, size);
+				break;
 				case eSSU2BlkI2NPMessage:
 				{
 					LogPrint (eLogDebug, "SSU2: I2NP message");
@@ -1742,6 +1737,32 @@ namespace transport
 		};
 	}
 
+	void SSU2Session::HandleRouterInfo (const uint8_t * buf, size_t len)
+	{
+		auto ri = ExtractRouterInfo (buf, len);
+		if (ri)
+		{	
+			// not from SessionConfirmed, we must add it instantly to use in next block
+			auto newRi = i2p::data::netdb.AddRouterInfo (ri->GetBuffer (), ri->GetBufferLen ());	// TODO: add ri
+			if (newRi)
+			{
+				auto remoteIdentity = GetRemoteIdentity ();
+				if (remoteIdentity && remoteIdentity->GetIdentHash () == newRi->GetIdentHash ())
+				{
+					// peer's RouterInfo update
+					SetRemoteIdentity (newRi->GetIdentity ());
+					auto address = m_RemoteEndpoint.address ().is_v6 () ? newRi->GetSSU2V6Address () : newRi->GetSSU2V4Address ();
+					if (address)
+					{
+						m_Address = address;
+						if (IsOutgoing () && m_RelayTag && !address->IsIntroducer ())
+							m_RelayTag = 0; // not longer introducer
+					}	
+				}	
+			}	
+		}	
+	}	
+		
 	void SSU2Session::HandleAck (const uint8_t * buf, size_t len)
 	{
 		if (m_State == eSSU2SessionStateSessionConfirmedSent)
diff --git a/libi2pd/SSU2Session.h b/libi2pd/SSU2Session.h
index 76dc55df..587f74b6 100644
--- a/libi2pd/SSU2Session.h
+++ b/libi2pd/SSU2Session.h
@@ -303,6 +303,7 @@ namespace transport
 
 			void HandlePayload (const uint8_t * buf, size_t len);
 			void HandleDateTime (const uint8_t * buf, size_t len);
+			void HandleRouterInfo (const uint8_t * buf, size_t len);
 			void HandleAck (const uint8_t * buf, size_t len);
 			void HandleAckRange (uint32_t firstPacketNum, uint32_t lastPacketNum, uint64_t ts);
 			void HandleAddress (const uint8_t * buf, size_t len);