From b10e5ce35819397d105b122396ce4c6f8cfc7716 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Sun, 26 Sep 2021 11:20:20 -0400
Subject: [PATCH] send ping

---
 libi2pd/Streaming.cpp | 51 ++++++++++++++++++++++++++++++++++++++++++-
 libi2pd/Streaming.h   |  4 +++-
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/libi2pd/Streaming.cpp b/libi2pd/Streaming.cpp
index c6447b5f..be3d09d8 100644
--- a/libi2pd/Streaming.cpp
+++ b/libi2pd/Streaming.cpp
@@ -490,7 +490,7 @@ namespace stream
 			handler(boost::system::error_code ());
 		m_Service.post (std::bind (&Stream::SendBuffer, shared_from_this ()));
 	}
-
+	
 	void Stream::SendBuffer ()
 	{
 		int numMsgs = m_WindowSize - m_SentPackets.size ();
@@ -665,6 +665,42 @@ namespace stream
 		LogPrint (eLogDebug, "Streaming: Quick Ack sent. ", (int)numNacks, " NACKs");
 	}
 
+	void Stream::SendPing ()
+	{
+		Packet p;
+		uint8_t * packet = p.GetBuffer ();
+		size_t size = 0;
+		htobe32buf (packet, m_RecvStreamID);
+		size += 4; // sendStreamID
+		memset (packet + size, 0, 14); 
+		size += 14; // all zeroes    
+		uint16_t flags = PACKET_FLAG_ECHO | PACKET_FLAG_SIGNATURE_INCLUDED | PACKET_FLAG_FROM_INCLUDED;
+		bool isOfflineSignature = m_LocalDestination.GetOwner ()->GetPrivateKeys ().IsOfflineSignature ();
+		if (isOfflineSignature) flags |= PACKET_FLAG_OFFLINE_SIGNATURE;
+		htobe16buf (packet + size, flags);
+		size += 2; // flags
+		size_t identityLen = m_LocalDestination.GetOwner ()->GetIdentity ()->GetFullLen ();
+		size_t signatureLen = m_LocalDestination.GetOwner ()->GetPrivateKeys ().GetSignatureLen ();
+		uint8_t * optionsSize = packet + size; // set options size later
+		size += 2; // options size
+		m_LocalDestination.GetOwner ()->GetIdentity ()->ToBuffer (packet + size, identityLen);
+		size += identityLen; // from
+		if (isOfflineSignature)
+		{
+			const auto& offlineSignature = m_LocalDestination.GetOwner ()->GetPrivateKeys ().GetOfflineSignature ();
+			memcpy (packet + size, offlineSignature.data (), offlineSignature.size ());
+			size += offlineSignature.size (); // offline signature
+		}
+		uint8_t * signature = packet + size; // set it later
+		memset (signature, 0, signatureLen); // zeroes for now
+		size += signatureLen; // signature
+		htobe16buf (optionsSize, packet + size - 2 - optionsSize); // actual options size
+		m_LocalDestination.GetOwner ()->Sign (packet, size, signature);		
+		p.len = size;
+		SendPackets (std::vector<Packet *> { &p });
+		LogPrint (eLogDebug, "Streaming: Ping of ", p.len, " bytes sent");
+	}	
+		
 	void Stream::Close ()
 	{
 		LogPrint(eLogDebug, "Streaming: closing stream with sSID=", m_SendStreamID, ", rSID=", m_RecvStreamID, ", status=", m_Status);
@@ -1103,6 +1139,13 @@ namespace stream
 		}
 		else
 		{
+			if (packet->IsEcho ())
+			{
+				// pong
+				LogPrint (eLogInfo, "Streaming: Pong received rSID=", packet->GetReceiveStreamID ());
+				DeletePacket (packet);
+				return;
+			}	
 			if (packet->IsSYN () && !packet->GetSeqn ()) // new incoming stream
 			{
 				uint32_t receiveStreamID = packet->GetReceiveStreamID ();
@@ -1197,6 +1240,12 @@ namespace stream
 		return s;
 	}
 
+	void  StreamingDestination::SendPing (std::shared_ptr<const i2p::data::LeaseSet> remote)
+	{
+		auto s = std::make_shared<Stream> (m_Owner->GetService (), *this, remote, 0);
+		s->SendPing ();
+	}	
+		
 	std::shared_ptr<Stream> StreamingDestination::CreateNewIncomingStream (uint32_t receiveStreamID)
 	{
 		auto s = std::make_shared<Stream> (m_Owner->GetService (), *this);
diff --git a/libi2pd/Streaming.h b/libi2pd/Streaming.h
index 189b1a64..c13dcab1 100644
--- a/libi2pd/Streaming.h
+++ b/libi2pd/Streaming.h
@@ -179,7 +179,8 @@ namespace stream
 			void HandlePing (Packet * packet);
 			size_t Send (const uint8_t * buf, size_t len);
 			void AsyncSend (const uint8_t * buf, size_t len, SendHandler handler);
-
+			void SendPing ();
+			
 			template<typename Buffer, typename ReceiveHandler>
 			void AsyncReceive (const Buffer& buffer, ReceiveHandler handler, int timeout = 0);
 			size_t ReadSome (uint8_t * buf, size_t len) { return ConcatenatePackets (buf, len); };
@@ -268,6 +269,7 @@ namespace stream
 			void Stop ();
 
 			std::shared_ptr<Stream> CreateNewOutgoingStream (std::shared_ptr<const i2p::data::LeaseSet> remote, int port = 0);
+			void SendPing (std::shared_ptr<const i2p::data::LeaseSet> remote);
 			void DeleteStream (std::shared_ptr<Stream> stream);
 			bool DeleteStream (uint32_t recvStreamID);
 			void SetAcceptor (const Acceptor& acceptor);