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/*
* Copyright (c) 2013-2020, The PurpleI2P Project
*
* This file is part of Purple i2pd project and licensed under BSD3
*
* See full license text in LICENSE file at top of project tree
*/
#ifndef DATAGRAM_H__
#define DATAGRAM_H__
#include <inttypes.h>
#include <memory>
#include <functional>
#include <map>
#include <vector>
#include "Base.h"
#include "Identity.h"
#include "LeaseSet.h"
#include "I2NPProtocol.h"
#include "Garlic.h"
namespace i2p
{
namespace client
{
class ClientDestination;
}
namespace datagram
{
// milliseconds for max session idle time
const uint64_t DATAGRAM_SESSION_MAX_IDLE = 10 * 60 * 1000;
// milliseconds for how long we try sticking to a dead routing path before trying to switch
const uint64_t DATAGRAM_SESSION_PATH_TIMEOUT = 10 * 1000;
// milliseconds interval a routing path is used before switching
const uint64_t DATAGRAM_SESSION_PATH_SWITCH_INTERVAL = 20 * 60 * 1000;
// milliseconds before lease expire should we try switching leases
const uint64_t DATAGRAM_SESSION_LEASE_HANDOVER_WINDOW = 30 * 1000;
// milliseconds fudge factor for leases handover
const uint64_t DATAGRAM_SESSION_LEASE_HANDOVER_FUDGE = 1000;
// milliseconds minimum time between path switches
const uint64_t DATAGRAM_SESSION_PATH_MIN_LIFETIME = 5 * 1000;
// max 64 messages buffered in send queue for each datagram session
const size_t DATAGRAM_SEND_QUEUE_MAX_SIZE = 64;
class DatagramSession : public std::enable_shared_from_this<DatagramSession>
{
public:
DatagramSession(std::shared_ptr<i2p::client::ClientDestination> localDestination, const i2p::data::IdentHash & remoteIdent);
void Start ();
void Stop ();
/** @brief ack the garlic routing path */
void Ack();
/** send an i2np message to remote endpoint for this session */
void SendMsg(std::shared_ptr<I2NPMessage> msg);
/** get the last time in milliseconds for when we used this datagram session */
uint64_t LastActivity() const { return m_LastUse; }
bool IsRatchets () const { return m_RoutingSession && m_RoutingSession->IsRatchets (); }
struct Info
{
std::shared_ptr<const i2p::data::IdentHash> IBGW;
std::shared_ptr<const i2p::data::IdentHash> OBEP;
const uint64_t activity;
Info() : IBGW(nullptr), OBEP(nullptr), activity(0) {}
Info(const uint8_t * ibgw, const uint8_t * obep, const uint64_t a) :
activity(a) {
if(ibgw) IBGW = std::make_shared<i2p::data::IdentHash>(ibgw);
else IBGW = nullptr;
if(obep) OBEP = std::make_shared<i2p::data::IdentHash>(obep);
else OBEP = nullptr;
}
};
Info GetSessionInfo() const;
private:
void FlushSendQueue();
void ScheduleFlushSendQueue();
void HandleSend(std::shared_ptr<I2NPMessage> msg);
std::shared_ptr<i2p::garlic::GarlicRoutingPath> GetSharedRoutingPath();
void HandleLeaseSetUpdated(std::shared_ptr<i2p::data::LeaseSet> ls);
private:
std::shared_ptr<i2p::client::ClientDestination> m_LocalDestination;
i2p::data::IdentHash m_RemoteIdent;
std::shared_ptr<const i2p::data::LeaseSet> m_RemoteLeaseSet;
std::shared_ptr<i2p::garlic::GarlicRoutingSession> m_RoutingSession;
std::shared_ptr<const i2p::data::Lease> m_CurrentRemoteLease;
std::shared_ptr<i2p::tunnel::OutboundTunnel> m_CurrentOutboundTunnel;
boost::asio::deadline_timer m_SendQueueTimer;
std::vector<std::shared_ptr<I2NPMessage> > m_SendQueue;
uint64_t m_LastUse;
bool m_RequestingLS;
};
typedef std::shared_ptr<DatagramSession> DatagramSession_ptr;
const size_t MAX_DATAGRAM_SIZE = 32768;
class DatagramDestination
{
typedef std::function<void (const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len)> Receiver;
typedef std::function<void (uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len)> RawReceiver;
public:
DatagramDestination (std::shared_ptr<i2p::client::ClientDestination> owner, bool gzip);
~DatagramDestination ();
void SendDatagramTo (const uint8_t * payload, size_t len, const i2p::data::IdentHash & ident, uint16_t fromPort = 0, uint16_t toPort = 0);
void SendRawDatagramTo (const uint8_t * payload, size_t len, const i2p::data::IdentHash & ident, uint16_t fromPort = 0, uint16_t toPort = 0);
void HandleDataMessagePayload (uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len, bool isRaw = false);
void SetReceiver (const Receiver& receiver) { m_Receiver = receiver; };
void ResetReceiver () { m_Receiver = nullptr; };
void SetReceiver (const Receiver& receiver, uint16_t port) { std::lock_guard<std::mutex> lock(m_ReceiversMutex); m_ReceiversByPorts[port] = receiver; };
void ResetReceiver (uint16_t port) { std::lock_guard<std::mutex> lock(m_ReceiversMutex); m_ReceiversByPorts.erase (port); };
void SetRawReceiver (const RawReceiver& receiver) { m_RawReceiver = receiver; };
void ResetRawReceiver () { m_RawReceiver = nullptr; };
std::shared_ptr<DatagramSession::Info> GetInfoForRemote(const i2p::data::IdentHash & remote);
// clean up stale sessions
void CleanUp ();
private:
std::shared_ptr<DatagramSession> ObtainSession(const i2p::data::IdentHash & ident);
std::shared_ptr<I2NPMessage> CreateDataMessage (const std::vector<std::pair<const uint8_t *, size_t> >& payloads,
uint16_t fromPort, uint16_t toPort, bool isRaw = false, bool checksum = true);
void HandleDatagram (uint16_t fromPort, uint16_t toPort, uint8_t *const& buf, size_t len);
void HandleRawDatagram (uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
/** find a receiver by port, if none by port is found try default receiever, otherwise returns nullptr */
Receiver FindReceiver(uint16_t port);
private:
std::shared_ptr<i2p::client::ClientDestination> m_Owner;
Receiver m_Receiver; // default
RawReceiver m_RawReceiver; // default
bool m_Gzip; // gzip compression of data messages
std::mutex m_SessionsMutex;
std::map<i2p::data::IdentHash, DatagramSession_ptr > m_Sessions;
std::mutex m_ReceiversMutex;
std::map<uint16_t, Receiver> m_ReceiversByPorts;
i2p::data::GzipInflator m_Inflator;
i2p::data::GzipDeflator m_Deflator;
std::vector<uint8_t> m_From, m_Signature;
};
}
}
#endif