I2P: End-to-End encrypted and anonymous Internet https://i2pd.website/
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/*
* Copyright (c) 2013-2022, 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
*/
#include "Log.h"
#include "util.h"
#include "ClientContext.h"
#include "I2PTunnel.h" // for GetLoopbackAddressFor
#include "UDPTunnel.h"
namespace i2p
{
namespace client
{
void I2PUDPServerTunnel::HandleRecvFromI2P(const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len)
{
if (!m_LastSession || m_LastSession->Identity.GetLL()[0] != from.GetIdentHash ().GetLL()[0] || fromPort != m_LastSession->RemotePort)
{
std::lock_guard<std::mutex> lock(m_SessionsMutex);
m_LastSession = ObtainUDPSession(from, toPort, fromPort);
}
m_LastSession->IPSocket.send_to(boost::asio::buffer(buf, len), m_RemoteEndpoint);
m_LastSession->LastActivity = i2p::util::GetMillisecondsSinceEpoch();
}
void I2PUDPServerTunnel::HandleRecvFromI2PRaw (uint16_t, uint16_t, const uint8_t * buf, size_t len)
{
if (m_LastSession)
{
m_LastSession->IPSocket.send_to(boost::asio::buffer(buf, len), m_RemoteEndpoint);
m_LastSession->LastActivity = i2p::util::GetMillisecondsSinceEpoch();
}
}
void I2PUDPServerTunnel::ExpireStale(const uint64_t delta)
{
std::lock_guard<std::mutex> lock(m_SessionsMutex);
uint64_t now = i2p::util::GetMillisecondsSinceEpoch();
auto itr = m_Sessions.begin();
while(itr != m_Sessions.end()) {
if(now - (*itr)->LastActivity >= delta )
itr = m_Sessions.erase(itr);
else
++itr;
}
}
void I2PUDPClientTunnel::ExpireStale(const uint64_t delta)
{
std::lock_guard<std::mutex> lock(m_SessionsMutex);
uint64_t now = i2p::util::GetMillisecondsSinceEpoch();
std::vector<uint16_t> removePorts;
for (const auto & s : m_Sessions) {
if (now - s.second->second >= delta)
removePorts.push_back(s.first);
}
for(auto port : removePorts) {
m_Sessions.erase(port);
}
}
UDPSessionPtr I2PUDPServerTunnel::ObtainUDPSession(const i2p::data::IdentityEx& from, uint16_t localPort, uint16_t remotePort)
{
auto ih = from.GetIdentHash();
for (auto & s : m_Sessions )
{
if (s->Identity.GetLL()[0] == ih.GetLL()[0] && remotePort == s->RemotePort)
{
/** found existing session */
LogPrint(eLogDebug, "UDPServer: Found session ", s->IPSocket.local_endpoint(), " ", ih.ToBase32());
return s;
}
}
boost::asio::ip::address addr;
/** create new udp session */
if(m_IsUniqueLocal && m_LocalAddress.is_loopback())
{
auto ident = from.GetIdentHash();
addr = GetLoopbackAddressFor(ident);
}
else
addr = m_LocalAddress;
boost::asio::ip::udp::endpoint ep(addr, 0);
m_Sessions.push_back(std::make_shared<UDPSession>(ep, m_LocalDest, m_RemoteEndpoint, ih, localPort, remotePort));
auto & back = m_Sessions.back();
return back;
}
UDPSession::UDPSession(boost::asio::ip::udp::endpoint localEndpoint,
const std::shared_ptr<i2p::client::ClientDestination> & localDestination,
const boost::asio::ip::udp::endpoint& endpoint, const i2p::data::IdentHash& to,
uint16_t ourPort, uint16_t theirPort) :
m_Destination(localDestination->GetDatagramDestination()),
IPSocket(localDestination->GetService(), localEndpoint),
Identity (to), SendEndpoint(endpoint),
LastActivity(i2p::util::GetMillisecondsSinceEpoch()),
LocalPort(ourPort),
RemotePort(theirPort)
{
IPSocket.set_option (boost::asio::socket_base::receive_buffer_size (I2P_UDP_MAX_MTU ));
Receive();
}
void UDPSession::Receive()
{
LogPrint(eLogDebug, "UDPSession: Receive");
IPSocket.async_receive_from(boost::asio::buffer(m_Buffer, I2P_UDP_MAX_MTU),
FromEndpoint, std::bind(&UDPSession::HandleReceived, this, std::placeholders::_1, std::placeholders::_2));
}
void UDPSession::HandleReceived(const boost::system::error_code & ecode, std::size_t len)
{
if(!ecode)
{
LogPrint(eLogDebug, "UDPSession: Forward ", len, "B from ", FromEndpoint);
auto ts = i2p::util::GetMillisecondsSinceEpoch();
auto session = m_Destination->GetSession (Identity);
if (ts > LastActivity + I2P_UDP_REPLIABLE_DATAGRAM_INTERVAL)
m_Destination->SendDatagram(session, m_Buffer, len, LocalPort, RemotePort);
else
m_Destination->SendRawDatagram(session, m_Buffer, len, LocalPort, RemotePort);
size_t numPackets = 0;
while (numPackets < i2p::datagram::DATAGRAM_SEND_QUEUE_MAX_SIZE)
{
boost::system::error_code ec;
size_t moreBytes = IPSocket.available(ec);
if (ec || !moreBytes) break;
len = IPSocket.receive_from (boost::asio::buffer (m_Buffer, I2P_UDP_MAX_MTU), FromEndpoint, 0, ec);
m_Destination->SendRawDatagram (session, m_Buffer, len, LocalPort, RemotePort);
numPackets++;
}
if (numPackets > 0)
LogPrint(eLogDebug, "UDPSession: Forward more ", numPackets, "packets B from ", FromEndpoint);
m_Destination->FlushSendQueue (session);
LastActivity = ts;
Receive();
}
else
LogPrint(eLogError, "UDPSession: ", ecode.message());
}
I2PUDPServerTunnel::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) :
m_IsUniqueLocal (true), m_Name (name), m_LocalAddress (localAddress),
m_RemoteEndpoint (forwardTo), m_LocalDest (localDestination), m_Gzip (gzip)
{
}
I2PUDPServerTunnel::~I2PUDPServerTunnel ()
{
Stop ();
}
void I2PUDPServerTunnel::Start ()
{
m_LocalDest->Start ();
auto dgram = m_LocalDest->CreateDatagramDestination (m_Gzip);
dgram->SetReceiver (std::bind (&I2PUDPServerTunnel::HandleRecvFromI2P, this, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, std::placeholders::_4, std::placeholders::_5));
dgram->SetRawReceiver (std::bind (&I2PUDPServerTunnel::HandleRecvFromI2PRaw, this, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, std::placeholders::_4));
}
void I2PUDPServerTunnel::Stop ()
{
auto dgram = m_LocalDest->GetDatagramDestination ();
if (dgram) dgram->ResetReceiver ();
}
std::vector<std::shared_ptr<DatagramSessionInfo> > I2PUDPServerTunnel::GetSessions ()
{
std::vector<std::shared_ptr<DatagramSessionInfo> > sessions;
std::lock_guard<std::mutex> lock (m_SessionsMutex);
for (UDPSessionPtr s: m_Sessions)
{
if (!s->m_Destination) continue;
auto info = s->m_Destination->GetInfoForRemote (s->Identity);
if (!info) continue;
auto sinfo = std::make_shared<DatagramSessionInfo> ();
sinfo->Name = m_Name;
sinfo->LocalIdent = std::make_shared<i2p::data::IdentHash> (m_LocalDest->GetIdentHash ().data ());
sinfo->RemoteIdent = std::make_shared<i2p::data::IdentHash> (s->Identity.data ());
sinfo->CurrentIBGW = info->IBGW;
sinfo->CurrentOBEP = info->OBEP;
sessions.push_back (sinfo);
}
return sessions;
}
I2PUDPClientTunnel::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) :
m_Name (name), m_RemoteDest (remoteDest), m_LocalDest (localDestination), m_LocalEndpoint (localEndpoint),
m_ResolveThread (nullptr), m_LocalSocket (nullptr), RemotePort (remotePort),
m_LastPort (0), m_cancel_resolve (false), m_Gzip (gzip)
{
}
I2PUDPClientTunnel::~I2PUDPClientTunnel ()
{
Stop ();
}
void I2PUDPClientTunnel::Start ()
{
// Reset flag in case of tunnel reload
if (m_cancel_resolve) m_cancel_resolve = false;
m_LocalSocket.reset (new boost::asio::ip::udp::socket (m_LocalDest->GetService (), m_LocalEndpoint));
m_LocalSocket->set_option (boost::asio::socket_base::receive_buffer_size (I2P_UDP_MAX_MTU));
m_LocalSocket->set_option (boost::asio::socket_base::reuse_address (true));
auto dgram = m_LocalDest->CreateDatagramDestination (m_Gzip);
dgram->SetReceiver (std::bind (&I2PUDPClientTunnel::HandleRecvFromI2P, this,
std::placeholders::_1, std::placeholders::_2,
std::placeholders::_3, std::placeholders::_4,
std::placeholders::_5));
dgram->SetRawReceiver (std::bind (&I2PUDPClientTunnel::HandleRecvFromI2PRaw, this,
std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, std::placeholders::_4));
m_LocalDest->Start ();
if (m_ResolveThread == nullptr)
m_ResolveThread = new std::thread (std::bind (&I2PUDPClientTunnel::TryResolving, this));
RecvFromLocal ();
}
void I2PUDPClientTunnel::Stop ()
{
auto dgram = m_LocalDest->GetDatagramDestination ();
if (dgram) dgram->ResetReceiver ();
m_cancel_resolve = true;
m_Sessions.clear();
if(m_LocalSocket && m_LocalSocket->is_open ())
m_LocalSocket->close ();
if(m_ResolveThread)
{
m_ResolveThread->join ();
delete m_ResolveThread;
m_ResolveThread = nullptr;
}
m_RemoteAddr = nullptr;
}
void I2PUDPClientTunnel::RecvFromLocal ()
{
m_LocalSocket->async_receive_from (boost::asio::buffer (m_RecvBuff, I2P_UDP_MAX_MTU),
m_RecvEndpoint, std::bind (&I2PUDPClientTunnel::HandleRecvFromLocal, this, std::placeholders::_1, std::placeholders::_2));
}
void I2PUDPClientTunnel::HandleRecvFromLocal (const boost::system::error_code & ec, std::size_t transferred)
{
if (m_cancel_resolve) {
LogPrint (eLogDebug, "UDP Client: Ignoring incomming data: stopping");
return;
}
if (ec) {
LogPrint (eLogError, "UDP Client: Reading from socket error: ", ec.message (), ". Restarting listener...");
RecvFromLocal (); // Restart listener and continue work
return;
}
if (!m_RemoteAddr || !m_RemoteAddr->IsIdentHash ()) // TODO: handle B33
{
LogPrint (eLogWarning, "UDP Client: Remote endpoint not resolved yet");
RecvFromLocal ();
return; // drop, remote not resolved
}
auto remotePort = m_RecvEndpoint.port ();
if (!m_LastPort || m_LastPort != remotePort)
{
auto itr = m_Sessions.find (remotePort);
if (itr != m_Sessions.end ())
m_LastSession = itr->second;
else
{
m_LastSession = std::make_shared<UDPConvo> (boost::asio::ip::udp::endpoint (m_RecvEndpoint), 0);
m_Sessions.emplace (remotePort, m_LastSession);
}
m_LastPort = remotePort;
}
// send off to remote i2p destination
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
LogPrint (eLogDebug, "UDP Client: Send ", transferred, " to ", m_RemoteAddr->identHash.ToBase32 (), ":", RemotePort);
auto session = m_LocalDest->GetDatagramDestination ()->GetSession (m_RemoteAddr->identHash);
if (ts > m_LastSession->second + I2P_UDP_REPLIABLE_DATAGRAM_INTERVAL)
m_LocalDest->GetDatagramDestination ()->SendDatagram (session, m_RecvBuff, transferred, remotePort, RemotePort);
else
m_LocalDest->GetDatagramDestination ()->SendRawDatagram (session, m_RecvBuff, transferred, remotePort, RemotePort);
size_t numPackets = 0;
while (numPackets < i2p::datagram::DATAGRAM_SEND_QUEUE_MAX_SIZE)
{
boost::system::error_code ec;
size_t moreBytes = m_LocalSocket->available (ec);
if (ec || !moreBytes) break;
transferred = m_LocalSocket->receive_from (boost::asio::buffer (m_RecvBuff, I2P_UDP_MAX_MTU), m_RecvEndpoint, 0, ec);
remotePort = m_RecvEndpoint.port ();
// TODO: check remotePort
m_LocalDest->GetDatagramDestination ()->SendRawDatagram (session, m_RecvBuff, transferred, remotePort, RemotePort);
numPackets++;
}
if (numPackets)
LogPrint (eLogDebug, "UDP Client: Sent ", numPackets, " more packets to ", m_RemoteAddr->identHash.ToBase32 ());
m_LocalDest->GetDatagramDestination ()->FlushSendQueue (session);
// mark convo as active
if (m_LastSession)
m_LastSession->second = ts;
RecvFromLocal ();
}
std::vector<std::shared_ptr<DatagramSessionInfo> > I2PUDPClientTunnel::GetSessions ()
{
// TODO: implement
std::vector<std::shared_ptr<DatagramSessionInfo> > infos;
return infos;
}
void I2PUDPClientTunnel::TryResolving ()
{
i2p::util::SetThreadName ("UDP Resolver");
LogPrint (eLogInfo, "UDP Tunnel: Trying to resolve ", m_RemoteDest);
std::shared_ptr<const Address> addr;
while (!(addr = context.GetAddressBook().GetAddress(m_RemoteDest)) && !m_cancel_resolve)
{
LogPrint (eLogWarning, "UDP Tunnel: Failed to lookup ", m_RemoteDest);
std::this_thread::sleep_for (std::chrono::seconds (1));
}
if (m_cancel_resolve)
{
LogPrint(eLogError, "UDP Tunnel: Lookup of ", m_RemoteDest, " was cancelled");
return;
}
if (!addr)
{
LogPrint (eLogError, "UDP Tunnel: ", m_RemoteDest, " not found");
return;
}
LogPrint(eLogInfo, "UDP Tunnel: Resolved ", m_RemoteDest, " to ", m_RemoteAddr->identHash.ToBase32 ());
}
void I2PUDPClientTunnel::HandleRecvFromI2P (const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len)
{
if (m_RemoteAddr && from.GetIdentHash() == m_RemoteAddr->identHash)
HandleRecvFromI2PRaw (fromPort, toPort, buf, len);
else
LogPrint(eLogWarning, "UDP Client: Unwarranted traffic from ", from.GetIdentHash().ToBase32 ());
}
void I2PUDPClientTunnel::HandleRecvFromI2PRaw (uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len)
{
auto itr = m_Sessions.find (toPort);
// found convo ?
if (itr != m_Sessions.end ())
{
// found convo
if (len > 0)
{
LogPrint (eLogDebug, "UDP Client: Got ", len, "B from ", m_RemoteAddr ? m_RemoteAddr->identHash.ToBase32 () : "");
m_LocalSocket->send_to (boost::asio::buffer (buf, len), itr->second->first);
// mark convo as active
itr->second->second = i2p::util::GetMillisecondsSinceEpoch ();
}
}
else
LogPrint (eLogWarning, "UDP Client: Not tracking udp session using port ", (int) toPort);
}
}
}