From 61d36ea8c390e79d494b044610a33cc0dbcb95c8 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Thu, 23 Oct 2014 16:56:50 -0400
Subject: [PATCH] send datagram

---
 Datagram.cpp | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 Datagram.h   | 12 +++++++++-
 2 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/Datagram.cpp b/Datagram.cpp
index 5c3cd259..e05b5463 100644
--- a/Datagram.cpp
+++ b/Datagram.cpp
@@ -1,11 +1,56 @@
+#include <string.h>
+#include <vector>
+#include <cryptopp/sha.h>
 #include <cryptopp/gzip.h>
 #include "Log.h"
+#include "TunnelBase.h"
+#include "RouterContext.h"
+#include "Destination.h"
 #include "Datagram.h"
 
 namespace i2p
 {
 namespace datagram
 {
+	DatagramDestination::DatagramDestination (i2p::client::ClientDestination& owner): 
+		m_Owner (owner) 
+	{
+		auto identityLen = m_Owner.GetIdentity ().ToBuffer (m_OutgoingBuffer, MAX_DATAGRAM_SIZE);
+		m_Signature = m_OutgoingBuffer + identityLen;
+		auto signatureLen = m_Owner.GetIdentity ().GetSignatureLen ();
+		m_Payload = m_Signature + signatureLen;
+		m_HeaderLen = identityLen + signatureLen;
+	}
+
+	void DatagramDestination::SendDatagramTo (const uint8_t * payload, size_t len, const i2p::data::LeaseSet& remote)
+	{
+		auto leases = remote.GetNonExpiredLeases ();
+		if (!leases.empty ())
+		{
+			memcpy (m_Payload, payload, len);
+			if (m_Owner.GetIdentity ().GetSigningKeyType () == i2p::data::SIGNING_KEY_TYPE_DSA_SHA1)
+			{
+				uint8_t hash[32];	
+				CryptoPP::SHA256().CalculateDigest (hash, m_Payload, len);
+				m_Owner.Sign (hash, 32, m_Signature);
+			}
+			else
+				m_Owner.Sign (m_Payload, len, m_Signature);
+
+			std::vector<i2p::tunnel::TunnelMessageBlock> msgs;			
+			uint32_t i = i2p::context.GetRandomNumberGenerator ().GenerateWord32 (0, leases.size () - 1);
+			auto msg = m_Owner.WrapMessage (remote, CreateDataMessage (m_OutgoingBuffer, len + m_HeaderLen));
+			msgs.push_back (i2p::tunnel::TunnelMessageBlock 
+				{ 
+					i2p::tunnel::eDeliveryTypeTunnel,
+					leases[i].tunnelGateway, leases[i].tunnelID,
+					msg
+				});
+		}
+		else
+			LogPrint ("Failed to send datagram. All leases expired");	
+	}
+
 	void DatagramDestination::HandleDataMessagePayload (const uint8_t * buf, size_t len)
 	{
 		// unzip it
@@ -24,6 +69,23 @@ namespace datagram
 
 	}
 
+	I2NPMessage * DatagramDestination::CreateDataMessage (const uint8_t * payload, size_t len)
+	{
+		I2NPMessage * msg = NewI2NPMessage ();
+		CryptoPP::Gzip compressor; // default level
+		compressor.Put (payload, len);
+		compressor.MessageEnd();
+		int size = compressor.MaxRetrievable ();
+		uint8_t * buf = msg->GetPayload ();
+		*(uint32_t *)buf = htobe32 (size); // length
+		buf += 4;
+		compressor.Get (buf, size);
+		memset (buf + 4, 0, 4); // source and destination are zeroes
+		buf[9] = i2p::client::PROTOCOL_TYPE_DATAGRAM; // datagram protocol
+		msg->len += size + 4; 
+		FillI2NPMessageHeader (msg, eI2NPData);
+		return msg;
+	}	
 }
 }
 
diff --git a/Datagram.h b/Datagram.h
index d5c21f6b..5d8f6f5b 100644
--- a/Datagram.h
+++ b/Datagram.h
@@ -2,6 +2,8 @@
 #define DATAGRAM_H__
 
 #include <inttypes.h>
+#include "LeaseSet.h"
+#include "I2NPProtocol.h"
 
 namespace i2p
 {
@@ -16,14 +18,22 @@ namespace datagram
 	{
 		public:
 
-			DatagramDestination (i2p::client::ClientDestination& owner): m_Owner (owner) {};
+			DatagramDestination (i2p::client::ClientDestination& owner);
 			~DatagramDestination () {};				
 
+			void SendDatagramTo (const uint8_t * payload, size_t len, const i2p::data::LeaseSet& remote);
 			void HandleDataMessagePayload (const uint8_t * buf, size_t len);
 
+		private:
+
+			I2NPMessage * CreateDataMessage (const uint8_t * payload, size_t len);
+
 		private:
 
 			i2p::client::ClientDestination& m_Owner;
+			uint8_t m_OutgoingBuffer[MAX_DATAGRAM_SIZE];
+			uint8_t * m_Signature, * m_Payload;
+			size_t m_HeaderLen;
 	};		
 }
 }