I2P: End-to-End encrypted and anonymous Internet https://i2pd.website/
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/*
* Copyright (c) 2013-2024, 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 UDPTUNNEL_H__
#define UDPTUNNEL_H__
#include <inttypes.h>
#include <string>
#include <memory>
#include <thread>
#include <vector>
#include <unordered_map>
#include <boost/asio.hpp>
#include "Identity.h"
#include "Destination.h"
#include "Datagram.h"
#include "AddressBook.h"
namespace i2p
{
namespace client
{
/** 2 minute timeout for udp sessions */
const uint64_t I2P_UDP_SESSION_TIMEOUT = 1000 * 60 * 2;
const uint64_t I2P_UDP_REPLIABLE_DATAGRAM_INTERVAL = 100; // in milliseconds
/** max size for i2p udp */
const size_t I2P_UDP_MAX_MTU = 64*1024;
struct UDPSession
{
i2p::datagram::DatagramDestination * m_Destination;
boost::asio::ip::udp::socket IPSocket;
i2p::data::IdentHash Identity;
boost::asio::ip::udp::endpoint FromEndpoint;
boost::asio::ip::udp::endpoint SendEndpoint;
uint64_t LastActivity;
uint16_t LocalPort;
uint16_t RemotePort;
uint8_t m_Buffer[I2P_UDP_MAX_MTU];
UDPSession(boost::asio::ip::udp::endpoint localEndpoint,
const std::shared_ptr<i2p::client::ClientDestination> & localDestination,
const boost::asio::ip::udp::endpoint& remote, const i2p::data::IdentHash& ident,
uint16_t ourPort, uint16_t theirPort);
void HandleReceived(const boost::system::error_code & ecode, std::size_t len);
void Receive();
};
/** read only info about a datagram session */
struct DatagramSessionInfo
{
/** the name of this forward */
std::string Name;
/** ident hash of local destination */
std::shared_ptr<const i2p::data::IdentHash> LocalIdent;
/** ident hash of remote destination */
std::shared_ptr<const i2p::data::IdentHash> RemoteIdent;
/** ident hash of IBGW in use currently in this session or nullptr if none is set */
std::shared_ptr<const i2p::data::IdentHash> CurrentIBGW;
/** ident hash of OBEP in use for this session or nullptr if none is set */
std::shared_ptr<const i2p::data::IdentHash> CurrentOBEP;
/** i2p router's udp endpoint */
boost::asio::ip::udp::endpoint LocalEndpoint;
/** client's udp endpoint */
boost::asio::ip::udp::endpoint RemoteEndpoint;
10 months ago
/** how long has this conversation been idle in ms */
uint64_t idle;
};
typedef std::shared_ptr<UDPSession> UDPSessionPtr;
/** server side udp tunnel, many i2p inbound to 1 ip outbound */
class I2PUDPServerTunnel
{
public:
I2PUDPServerTunnel (const std::string & name,
std::shared_ptr<i2p::client::ClientDestination> localDestination,
const boost::asio::ip::address& localAddress,
const boost::asio::ip::udp::endpoint& forwardTo, uint16_t port, bool gzip);
~I2PUDPServerTunnel ();
/** expire stale udp conversations */
void ExpireStale (const uint64_t delta=I2P_UDP_SESSION_TIMEOUT);
void Start ();
void Stop ();
const char * GetName () const { return m_Name.c_str(); }
std::vector<std::shared_ptr<DatagramSessionInfo> > GetSessions ();
std::shared_ptr<ClientDestination> GetLocalDestination () const { return m_LocalDest; }
void SetUniqueLocal (bool isUniqueLocal = true) { m_IsUniqueLocal = isUniqueLocal; }
private:
void HandleRecvFromI2P (const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
void HandleRecvFromI2PRaw (uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
UDPSessionPtr ObtainUDPSession (const i2p::data::IdentityEx& from, uint16_t localPort, uint16_t remotePort);
uint32_t GetSessionIndex (uint16_t fromPort, uint16_t toPort) const { return ((uint32_t)fromPort << 16) + toPort; }
private:
bool m_IsUniqueLocal;
const std::string m_Name;
boost::asio::ip::address m_LocalAddress;
boost::asio::ip::udp::endpoint m_RemoteEndpoint;
std::mutex m_SessionsMutex;
std::unordered_map<uint32_t, UDPSessionPtr> m_Sessions; // (from port, to port)->session
std::shared_ptr<i2p::client::ClientDestination> m_LocalDest;
UDPSessionPtr m_LastSession;
uint16_t m_inPort;
bool m_Gzip;
public:
bool isUpdated; // transient, used during reload only
};
class I2PUDPClientTunnel
{
public:
I2PUDPClientTunnel (const std::string & name, const std::string &remoteDest,
const boost::asio::ip::udp::endpoint& localEndpoint, std::shared_ptr<i2p::client::ClientDestination> localDestination,
uint16_t remotePort, bool gzip);
~I2PUDPClientTunnel ();
void Start ();
void Stop ();
const char * GetName () const { return m_Name.c_str(); }
std::vector<std::shared_ptr<DatagramSessionInfo> > GetSessions ();
bool IsLocalDestination (const i2p::data::IdentHash & destination) const { return destination == m_LocalDest->GetIdentHash(); }
std::shared_ptr<ClientDestination> GetLocalDestination () const { return m_LocalDest; }
inline void SetLocalDestination (std::shared_ptr<ClientDestination> dest)
{
if (m_LocalDest) m_LocalDest->Release ();
if (dest) dest->Acquire ();
m_LocalDest = dest;
}
void ExpireStale (const uint64_t delta=I2P_UDP_SESSION_TIMEOUT);
private:
typedef std::pair<boost::asio::ip::udp::endpoint, uint64_t> UDPConvo;
void RecvFromLocal ();
void HandleRecvFromLocal (const boost::system::error_code & e, std::size_t transferred);
void HandleRecvFromI2P (const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
void HandleRecvFromI2PRaw (uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
void TryResolving ();
private:
const std::string m_Name;
std::mutex m_SessionsMutex;
std::unordered_map<uint16_t, std::shared_ptr<UDPConvo> > m_Sessions; // maps i2p port -> local udp convo
const std::string m_RemoteDest;
std::shared_ptr<i2p::client::ClientDestination> m_LocalDest;
const boost::asio::ip::udp::endpoint m_LocalEndpoint;
std::shared_ptr<const Address> m_RemoteAddr;
std::thread * m_ResolveThread;
std::unique_ptr<boost::asio::ip::udp::socket> m_LocalSocket;
boost::asio::ip::udp::endpoint m_RecvEndpoint;
uint8_t m_RecvBuff[I2P_UDP_MAX_MTU];
uint16_t RemotePort, m_LastPort;
bool m_cancel_resolve;
bool m_Gzip;
std::shared_ptr<UDPConvo> m_LastSession;
public:
bool isUpdated; // transient, used during reload only
};
}
}
#endif