From 4ebc7c970a168257c21f823b9fff792458a1ab25 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Mon, 10 Apr 2023 23:04:38 -0400
Subject: [PATCH] bypass medium congestion(D) routers for client tunnels

---
 libi2pd/NetDb.cpp      |  4 ++--
 libi2pd/RouterInfo.cpp | 24 ++++++++++++++++++------
 libi2pd/RouterInfo.h   |  2 +-
 libi2pd/TunnelPool.cpp |  5 +++--
 libi2pd/TunnelPool.h   |  2 +-
 5 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/libi2pd/NetDb.cpp b/libi2pd/NetDb.cpp
index 3847f24f..c9c92b64 100644
--- a/libi2pd/NetDb.cpp
+++ b/libi2pd/NetDb.cpp
@@ -1172,7 +1172,7 @@ namespace data
 				return !router->IsHidden () && router != compatibleWith &&
 					(reverse ? compatibleWith->IsReachableFrom (*router) :
 						router->IsReachableFrom (*compatibleWith)) &&
-					router->IsECIES ();
+					router->IsECIES () && !router->IsHighCongestion (false);
 			});
 	}
 
@@ -1206,7 +1206,7 @@ namespace data
 						router->IsReachableFrom (*compatibleWith)) &&
 					(router->GetCaps () & RouterInfo::eHighBandwidth) &&
 					router->GetVersion () >= NETDB_MIN_HIGHBANDWIDTH_VERSION &&
-					router->IsECIES () && !router->IsHighCongestion ();
+					router->IsECIES () && !router->IsHighCongestion (true);
 			});
 	}
 
diff --git a/libi2pd/RouterInfo.cpp b/libi2pd/RouterInfo.cpp
index 34bd705d..c18e0521 100644
--- a/libi2pd/RouterInfo.cpp
+++ b/libi2pd/RouterInfo.cpp
@@ -1113,13 +1113,25 @@ namespace data
 		m_Timestamp = i2p::util::GetMillisecondsSinceEpoch ();
 	}
 
-	bool RouterInfo::IsHighCongestion () const
+	bool RouterInfo::IsHighCongestion (bool highBandwidth) const
 	{
-		if (m_Congestion == eLowCongestion || m_Congestion == eMediumCongestion) return false;
-		if (m_Congestion == eRejectAll) return true;
-		if (m_Congestion == eHighCongestion)
-			return 	(i2p::util::GetMillisecondsSinceEpoch () < m_Timestamp + HIGH_CONGESTION_INTERVAL*1000LL) ? true : false;
-		return false;
+		switch (m_Congestion)
+		{
+			case eLowCongestion:
+				return false;
+			break;
+			case eMediumCongestion:
+				return highBandwidth;
+			break;
+			case eHighCongestion:
+				return i2p::util::GetMillisecondsSinceEpoch () < m_Timestamp + HIGH_CONGESTION_INTERVAL*1000LL;
+			break;	
+			case eRejectAll:
+				return true;
+			break;	
+			default:
+				return false;
+		}
 	}
 		
 	void LocalRouterInfo::CreateBuffer (const PrivateKeys& privateKeys)
diff --git a/libi2pd/RouterInfo.h b/libi2pd/RouterInfo.h
index 3789438d..070737e8 100644
--- a/libi2pd/RouterInfo.h
+++ b/libi2pd/RouterInfo.h
@@ -250,7 +250,7 @@ namespace data
 			bool IsPublished (bool v4) const;
 			bool IsSSU2PeerTesting (bool v4) const;
 			bool IsSSU2Introducer (bool v4) const;
-			bool IsHighCongestion () const;
+			bool IsHighCongestion (bool highBandwidth) const;
 
 			uint8_t GetCaps () const { return m_Caps; };
 			void SetCaps (uint8_t caps) { m_Caps = caps; };
diff --git a/libi2pd/TunnelPool.cpp b/libi2pd/TunnelPool.cpp
index d21347e6..3dc0256e 100644
--- a/libi2pd/TunnelPool.cpp
+++ b/libi2pd/TunnelPool.cpp
@@ -753,14 +753,15 @@ namespace tunnel
 		return m_CustomPeerSelector != nullptr;
 	}
 
-	bool TunnelPool::ValidatePeers (std::vector<std::shared_ptr<const i2p::data::IdentityEx> >& peers)
+	bool TunnelPool::ValidatePeers (std::vector<std::shared_ptr<const i2p::data::IdentityEx> >& peers) const
 	{
+		bool highBandwidth = !IsExploratory ();
 		for (auto it: peers)
 		{
 			auto r = i2p::data::netdb.FindRouter (it->GetIdentHash ());
 			if (r)
 			{
-				if (r->IsHighCongestion ()) return false;
+				if (r->IsHighCongestion (highBandwidth)) return false;
 				it = r->GetIdentity (); // use identity from updated RouterInfo
 			}	
 		}	
diff --git a/libi2pd/TunnelPool.h b/libi2pd/TunnelPool.h
index f49ce309..e9dd142e 100644
--- a/libi2pd/TunnelPool.h
+++ b/libi2pd/TunnelPool.h
@@ -126,7 +126,7 @@ namespace tunnel
 				typename TTunnels::value_type excluded, i2p::data::RouterInfo::CompatibleTransports compatible) const;
 			bool SelectPeers (Path& path, bool isInbound);
 			bool SelectExplicitPeers (Path& path, bool isInbound);
-			static bool ValidatePeers (std::vector<std::shared_ptr<const i2p::data::IdentityEx> >& peers);
+			bool ValidatePeers (std::vector<std::shared_ptr<const i2p::data::IdentityEx> >& peers) const;
 
 		private: