i2pd/tunnel/TransitTunnel.cpp

#include <string.h>
#include "util/I2PEndian.h"
#include "util/Log.h"
#include "RouterContext.h"
#include "I2NPProtocol.h"
#include "Tunnel.h"
#include "transport/Transports.h"
#include "TransitTunnel.h"

namespace i2p
{
namespace tunnel
{   
    TransitTunnel::TransitTunnel (uint32_t receiveTunnelID, 
        const uint8_t * nextIdent, uint32_t nextTunnelID, 
        const uint8_t * layerKey,const uint8_t * ivKey): 
            m_TunnelID (receiveTunnelID),  m_NextTunnelID (nextTunnelID), 
            m_NextIdent (nextIdent)
    {   
        m_Encryption.SetKeys (layerKey, ivKey);
    }   

    void TransitTunnel::EncryptTunnelMsg (std::shared_ptr<const I2NPMessage> in, std::shared_ptr<I2NPMessage> out)
    {       
        m_Encryption.Encrypt (in->GetPayload () + 4, out->GetPayload () + 4); 
    }   

    TransitTunnelParticipant::~TransitTunnelParticipant ()
    {
    }   
        
    void TransitTunnelParticipant::HandleTunnelDataMsg (std::shared_ptr<const i2p::I2NPMessage> tunnelMsg)
    {
        auto newMsg = CreateEmptyTunnelDataMsg ();
        EncryptTunnelMsg (tunnelMsg, newMsg);
        
        m_NumTransmittedBytes += tunnelMsg->GetLength ();
        htobe32buf (newMsg->GetPayload (), GetNextTunnelID ());
        newMsg->FillI2NPMessageHeader (eI2NPTunnelData); 
        m_TunnelDataMsgs.push_back (newMsg);
    }

    void TransitTunnelParticipant::FlushTunnelDataMsgs ()
    {
        if (!m_TunnelDataMsgs.empty ())
        {   
            auto num = m_TunnelDataMsgs.size ();
            if (num > 1)
                LogPrint (eLogDebug, "TransitTunnel: ",GetTunnelID (),"->", GetNextTunnelID (), " ", num);
            i2p::transport::transports.SendMessages (GetNextIdentHash (), m_TunnelDataMsgs);
            m_TunnelDataMsgs.clear ();
        }   
    }   
        
    void TransitTunnel::SendTunnelDataMsg (std::shared_ptr<i2p::I2NPMessage> msg)
    {   
        LogPrint (eLogError, "We are not a gateway for transit tunnel ", m_TunnelID);
    }       

    void TransitTunnel::HandleTunnelDataMsg (std::shared_ptr<const i2p::I2NPMessage> tunnelMsg)
    {
        LogPrint (eLogError, "Incoming tunnel message is not supported  ", m_TunnelID);
    }   
        
    void TransitTunnelGateway::SendTunnelDataMsg (std::shared_ptr<i2p::I2NPMessage> msg)
    {
        TunnelMessageBlock block;
        block.deliveryType = eDeliveryTypeLocal;
        block.data = msg;
        std::unique_lock<std::mutex> l(m_SendMutex);
        m_Gateway.PutTunnelDataMsg (block);
    }       

    void TransitTunnelGateway::FlushTunnelDataMsgs ()
    {
        std::unique_lock<std::mutex> l(m_SendMutex);
        m_Gateway.SendBuffer ();
    }   
        
    void TransitTunnelEndpoint::HandleTunnelDataMsg (std::shared_ptr<const i2p::I2NPMessage> tunnelMsg)
    {
        auto newMsg = CreateEmptyTunnelDataMsg ();
        EncryptTunnelMsg (tunnelMsg, newMsg);
        
        LogPrint (eLogDebug, "TransitTunnel endpoint for ", GetTunnelID ());
        m_Endpoint.HandleDecryptedTunnelDataMsg (newMsg); 
    }
        
    TransitTunnel * CreateTransitTunnel (uint32_t receiveTunnelID,
        const uint8_t * nextIdent, uint32_t nextTunnelID, 
        const uint8_t * layerKey,const uint8_t * ivKey, 
        bool isGateway, bool isEndpoint)
    {
        if (isEndpoint)
        {   
            LogPrint (eLogInfo, "TransitTunnel endpoint: ", receiveTunnelID, " created");
            return new TransitTunnelEndpoint (receiveTunnelID, nextIdent, nextTunnelID, layerKey, ivKey);
        }   
        else if (isGateway)
        {   
            LogPrint (eLogInfo, "TransitTunnel gateway: ", receiveTunnelID, " created");
            return new TransitTunnelGateway (receiveTunnelID, nextIdent, nextTunnelID, layerKey, ivKey);
        }   
        else    
        {   
            LogPrint (eLogInfo, "TransitTunnel: ", receiveTunnelID, "->", nextTunnelID, " created");
            return new TransitTunnelParticipant (receiveTunnelID, nextIdent, nextTunnelID, layerKey, ivKey);
        }   
    }       
}
}