From f0084785059b8e78acef3301e1fd818ec6b0c73b Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Mon, 29 Jan 2024 19:54:43 -0500
Subject: [PATCH] handle I2NP messages drops

---
 libi2pd/I2NPProtocol.h    | 7 +++++--
 libi2pd/NTCP2.cpp         | 1 +
 libi2pd/NetDb.cpp         | 6 +++++-
 libi2pd/NetDbRequests.cpp | 6 +++++-
 libi2pd/SSU2Session.cpp   | 1 +
 libi2pd/Transports.h      | 7 +++++++
 6 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/libi2pd/I2NPProtocol.h b/libi2pd/I2NPProtocol.h
index e86f4f32..a2877a08 100644
--- a/libi2pd/I2NPProtocol.h
+++ b/libi2pd/I2NPProtocol.h
@@ -13,6 +13,7 @@
 #include <string.h>
 #include <set>
 #include <memory>
+#include <functional>
 #include "Crypto.h"
 #include "I2PEndian.h"
 #include "Identity.h"
@@ -149,7 +150,8 @@ namespace tunnel
 		uint8_t * buf;
 		size_t len, offset, maxLen;
 		std::shared_ptr<i2p::tunnel::InboundTunnel> from;
-
+		std::function<void ()> onDrop;
+		
 		I2NPMessage (): buf (nullptr),len (I2NP_HEADER_SIZE + 2),
 			offset(2), maxLen (0), from (nullptr) {}; // reserve 2 bytes for NTCP header
 
@@ -241,7 +243,6 @@ namespace tunnel
 			SetSize (len - offset - I2NP_HEADER_SIZE);
 			SetChks (0);
 		}
-
 		void ToNTCP2 ()
 		{
 			uint8_t * ntcp2 = GetNTCP2Header ();
@@ -253,6 +254,8 @@ namespace tunnel
 		void RenewI2NPMessageHeader ();
 		bool IsExpired () const;
 		bool IsExpired (uint64_t ts) const; // in milliseconds
+
+		void Drop () { if (onDrop) { onDrop (); onDrop = nullptr; }; }
 	};
 
 	template<int sz>
diff --git a/libi2pd/NTCP2.cpp b/libi2pd/NTCP2.cpp
index fff2fdc7..ad8ef51d 100644
--- a/libi2pd/NTCP2.cpp
+++ b/libi2pd/NTCP2.cpp
@@ -1140,6 +1140,7 @@ namespace transport
 				if (!msg || msg->IsExpired (ts))
 				{
 					// drop null or expired message
+					if (msg) msg->Drop ();
 					m_SendQueue.pop_front ();
 					continue;
 				}	
diff --git a/libi2pd/NetDb.cpp b/libi2pd/NetDb.cpp
index f1be7520..0bf7af9d 100644
--- a/libi2pd/NetDb.cpp
+++ b/libi2pd/NetDb.cpp
@@ -736,7 +736,11 @@ namespace data
 				!i2p::transport::transports.IsConnected (floodfill->GetIdentHash ()))
 				direct = false; // floodfill can't be reached directly
 			if (direct)
-				transports.SendMessage (floodfill->GetIdentHash (), dest->CreateRequestMessage (floodfill->GetIdentHash ()));
+			{
+				auto msg = dest->CreateRequestMessage (floodfill->GetIdentHash ());
+				msg->onDrop = [this, dest]() { this->m_Requests.SendNextRequest (dest); }; 
+				transports.SendMessage (floodfill->GetIdentHash (), msg);
+			}	
 			else
 			{
 				auto pool = i2p::tunnel::tunnels.GetExploratoryPool ();
diff --git a/libi2pd/NetDbRequests.cpp b/libi2pd/NetDbRequests.cpp
index 92e5a7b8..4099f921 100644
--- a/libi2pd/NetDbRequests.cpp
+++ b/libi2pd/NetDbRequests.cpp
@@ -188,7 +188,11 @@ namespace data
 					!i2p::transport::transports.IsConnected (nextFloodfill->GetIdentHash ()))
 					direct = false; // floodfill can't be reached directly
 				if (direct)
-					i2p::transport::transports.SendMessage (nextFloodfill->GetIdentHash (), dest->CreateRequestMessage (nextFloodfill->GetIdentHash ()));
+				{
+					auto msg = dest->CreateRequestMessage (nextFloodfill->GetIdentHash ());
+					msg->onDrop = [this, dest]() { this->SendNextRequest (dest); }; 
+					i2p::transport::transports.SendMessage (nextFloodfill->GetIdentHash (), msg);
+				}	
 				else
 				{	
 					auto pool = i2p::tunnel::tunnels.GetExploratoryPool ();
diff --git a/libi2pd/SSU2Session.cpp b/libi2pd/SSU2Session.cpp
index 5c951391..fa6d9eca 100644
--- a/libi2pd/SSU2Session.cpp
+++ b/libi2pd/SSU2Session.cpp
@@ -382,6 +382,7 @@ namespace transport
 				if (!msg || msg->IsExpired (ts))
 				{
 					// drop null or expired message
+					if (msg) msg->Drop ();
 					m_SendQueue.pop_front ();
 					continue;
 				}
diff --git a/libi2pd/Transports.h b/libi2pd/Transports.h
index 0e5518b1..c78a8bd0 100644
--- a/libi2pd/Transports.h
+++ b/libi2pd/Transports.h
@@ -86,6 +86,13 @@ namespace transport
 			}	
 		}
 
+		~Peer ()
+		{
+			// drop not sent delayed messages
+			for (auto& it: delayedMessages)
+				it->Drop ();
+		}	
+			
 		void Done ()
 		{
 			for (auto& it: sessions)