i2pd/libi2pd/Destination.cpp

#include <algorithm>
#include <cassert>
#include <string>
#include "Crypto.h"
#include "Log.h"
#include "FS.h"
#include "Timestamp.h"
#include "NetDb.hpp"
#include "Destination.h"
#include "util.h"

namespace i2p
{
namespace client
{
	LeaseSetDestination::LeaseSetDestination (bool isPublic, const std::map<std::string, std::string> * params):
		m_IsRunning (false), m_Thread (nullptr), m_IsPublic (isPublic),
		m_PublishReplyToken (0), m_LastSubmissionTime (0), m_PublishConfirmationTimer (m_Service),
		m_PublishVerificationTimer (m_Service), m_PublishDelayTimer (m_Service), m_CleanupTimer (m_Service)
	{
		int inLen   = DEFAULT_INBOUND_TUNNEL_LENGTH;
		int inQty   = DEFAULT_INBOUND_TUNNELS_QUANTITY;
		int outLen  = DEFAULT_OUTBOUND_TUNNEL_LENGTH;
		int outQty  = DEFAULT_OUTBOUND_TUNNELS_QUANTITY;
		int numTags = DEFAULT_TAGS_TO_SEND;
		std::shared_ptr<std::vector<i2p::data::IdentHash> > explicitPeers;
		try
		{
			if (params)
			{
				auto it = params->find (I2CP_PARAM_INBOUND_TUNNEL_LENGTH);
				if (it != params->end ())
					inLen = std::stoi(it->second);
				it = params->find (I2CP_PARAM_OUTBOUND_TUNNEL_LENGTH);
				if (it != params->end ())
					outLen = std::stoi(it->second);
				it = params->find (I2CP_PARAM_INBOUND_TUNNELS_QUANTITY);
				if (it != params->end ())
					inQty = std::stoi(it->second);
				it = params->find (I2CP_PARAM_OUTBOUND_TUNNELS_QUANTITY);
				if (it != params->end ())
					outQty = std::stoi(it->second);
				it = params->find (I2CP_PARAM_TAGS_TO_SEND);
				if (it != params->end ())
					numTags = std::stoi(it->second);
				LogPrint (eLogInfo, "Destination: parameters for tunnel set to: ", inQty, " inbound (", inLen, " hops), ", outQty, " outbound (", outLen, " hops), ", numTags, " tags");
				it = params->find (I2CP_PARAM_EXPLICIT_PEERS);
				if (it != params->end ())
				{
					explicitPeers = std::make_shared<std::vector<i2p::data::IdentHash> >();
					std::stringstream ss(it->second);
					std::string b64;
					while (std::getline (ss, b64, ','))
					{
						i2p::data::IdentHash ident;
						ident.FromBase64 (b64);
						explicitPeers->push_back (ident);
						LogPrint (eLogInfo, "Destination: Added to explicit peers list: ", b64);
					}
				}
				it = params->find (I2CP_PARAM_INBOUND_NICKNAME);
				if (it != params->end ()) m_Nickname = it->second;
				else // try outbound
				{
					it = params->find (I2CP_PARAM_OUTBOUND_NICKNAME);
					if (it != params->end ()) m_Nickname = it->second;
					// otherwise we set default nickname in Start when we know local address
				}
			}
		}
		catch (std::exception & ex)
		{
			LogPrint(eLogError, "Destination: unable to parse parameters for destination: ", ex.what());
		}
		SetNumTags (numTags);
		m_Pool = i2p::tunnel::tunnels.CreateTunnelPool (inLen, outLen, inQty, outQty);
		if (explicitPeers)
			m_Pool->SetExplicitPeers (explicitPeers);
		if(params)
		{
			auto itr = params->find(I2CP_PARAM_MAX_TUNNEL_LATENCY);
			if (itr != params->end()) {
				auto maxlatency = std::stoi(itr->second);
				itr = params->find(I2CP_PARAM_MIN_TUNNEL_LATENCY);
				if (itr != params->end()) {
					auto minlatency = std::stoi(itr->second);
					if ( minlatency > 0 && maxlatency > 0 ) {
						// set tunnel pool latency
						LogPrint(eLogInfo, "Destination: requiring tunnel latency [", minlatency, "ms, ", maxlatency, "ms]");
						m_Pool->RequireLatency(minlatency, maxlatency);
					}
				}
			}
		}
	}

	LeaseSetDestination::~LeaseSetDestination ()
	{
		if (m_IsRunning)
			Stop ();
		if (m_Pool)
			i2p::tunnel::tunnels.DeleteTunnelPool (m_Pool);
		for (auto& it: m_LeaseSetRequests)
			it.second->Complete (nullptr);
	}

	void LeaseSetDestination::Run ()
	{
		while (m_IsRunning)
		{
			try
			{
				m_Service.run ();
			}
			catch (std::exception& ex)
			{
				LogPrint (eLogError, "Destination: runtime exception: ", ex.what ());
			}
		}
	}

	bool LeaseSetDestination::Start ()
	{
		if (!m_IsRunning)
		{
			if (m_Nickname.empty ())
				m_Nickname = i2p::data::GetIdentHashAbbreviation (GetIdentHash ()); // set default nickname
			LoadTags ();
			m_IsRunning = true;
			m_Pool->SetLocalDestination (shared_from_this ());
			m_Pool->SetActive (true);
			m_CleanupTimer.expires_from_now (boost::posix_time::minutes (DESTINATION_CLEANUP_TIMEOUT));
			m_CleanupTimer.async_wait (std::bind (&LeaseSetDestination::HandleCleanupTimer,
				shared_from_this (), std::placeholders::_1));
			m_Thread = new std::thread (std::bind (&LeaseSetDestination::Run, shared_from_this ()));

			return true;
		}
		else
			return false;
	}

	bool LeaseSetDestination::Stop ()
	{
		if (m_IsRunning)
		{
			m_CleanupTimer.cancel ();
			m_PublishConfirmationTimer.cancel ();
			m_PublishVerificationTimer.cancel ();

			m_IsRunning = false;
			if (m_Pool)
			{
				m_Pool->SetLocalDestination (nullptr);
				i2p::tunnel::tunnels.StopTunnelPool (m_Pool);
			}
			m_Service.stop ();
			if (m_Thread)
			{
				m_Thread->join ();
				delete m_Thread;
				m_Thread = 0;
			}
			SaveTags ();
			CleanUp (); // GarlicDestination
			return true;
		}
		else
			return false;
	}

	bool LeaseSetDestination::Reconfigure(std::map<std::string, std::string> params)
	{
		
		auto itr = params.find("i2cp.dontPublishLeaseSet");
		if (itr != params.end())
		{
			m_IsPublic = itr->second != "true";
		}
		
		int inLen, outLen, inQuant, outQuant, numTags, minLatency, maxLatency;
		std::map<std::string, int&> intOpts = {
			{I2CP_PARAM_INBOUND_TUNNEL_LENGTH, inLen},
			{I2CP_PARAM_OUTBOUND_TUNNEL_LENGTH, outLen},
			{I2CP_PARAM_INBOUND_TUNNELS_QUANTITY, inQuant},
			{I2CP_PARAM_OUTBOUND_TUNNELS_QUANTITY, outQuant},
			{I2CP_PARAM_TAGS_TO_SEND, numTags},
			{I2CP_PARAM_MIN_TUNNEL_LATENCY, minLatency},
			{I2CP_PARAM_MAX_TUNNEL_LATENCY, maxLatency}
		};

		auto pool = GetTunnelPool();
		inLen = pool->GetNumInboundHops();
		outLen = pool->GetNumOutboundHops();
		inQuant = pool->GetNumInboundTunnels();
		outQuant = pool->GetNumOutboundTunnels();
		minLatency = 0;
		maxLatency = 0;
		
		for (auto & opt : intOpts)
		{
			itr = params.find(opt.first);
			if(itr != params.end())
			{
				opt.second = std::stoi(itr->second);
			}
		}
		pool->RequireLatency(minLatency, maxLatency);
		return pool->Reconfigure(inLen, outLen, inQuant, outQuant);
	}
	
	std::shared_ptr<const i2p::data::LeaseSet> LeaseSetDestination::FindLeaseSet (const i2p::data::IdentHash& ident)
	{
		std::shared_ptr<i2p::data::LeaseSet> remoteLS;
		{
			std::lock_guard<std::mutex> lock(m_RemoteLeaseSetsMutex);
			auto it = m_RemoteLeaseSets.find (ident);
			if (it != m_RemoteLeaseSets.end ())
				remoteLS = it->second;
		}

		if (remoteLS)
		{
			if (!remoteLS->IsExpired ())
			{
				if (remoteLS->ExpiresSoon())
				{
					LogPrint(eLogDebug, "Destination: Lease Set expires soon, updating before expire");
					// update now before expiration for smooth handover
					auto s = shared_from_this ();
					RequestDestination(ident, [s, ident] (std::shared_ptr<i2p::data::LeaseSet> ls) {
						if(ls && !ls->IsExpired())
						{
							ls->PopulateLeases();
							{
								std::lock_guard<std::mutex> _lock(s->m_RemoteLeaseSetsMutex);
								s->m_RemoteLeaseSets[ident] = ls;
							}
						}
					});
				}
				return remoteLS;
			}
			else
			{
				LogPrint (eLogWarning, "Destination: remote LeaseSet expired");
				std::lock_guard<std::mutex> lock(m_RemoteLeaseSetsMutex);
				m_RemoteLeaseSets.erase (ident);
				return nullptr;
			}
		}
		else
		{
			auto ls = i2p::data::netdb.FindLeaseSet (ident);
			if (ls && !ls->IsExpired ())
			{
				ls->PopulateLeases (); // since we don't store them in netdb
				std::lock_guard<std::mutex> _lock(m_RemoteLeaseSetsMutex);
				m_RemoteLeaseSets[ident] = ls;
				return ls;
			}
		}
		return nullptr;
	}

	std::shared_ptr<const i2p::data::LocalLeaseSet> LeaseSetDestination::GetLeaseSet ()
	{
		if (!m_Pool) return nullptr;
		if (!m_LeaseSet)
			UpdateLeaseSet ();
		std::lock_guard<std::mutex> l(m_LeaseSetMutex);
		return m_LeaseSet;
	}

	void LeaseSetDestination::SetLeaseSet (i2p::data::LocalLeaseSet * newLeaseSet)
	{
		{
			std::lock_guard<std::mutex> l(m_LeaseSetMutex);
			m_LeaseSet.reset (newLeaseSet);
		}
		i2p::garlic::GarlicDestination::SetLeaseSetUpdated ();
		if (m_IsPublic)
		{
			auto s = shared_from_this ();
			m_Service.post ([s](void)
			{
				s->m_PublishVerificationTimer.cancel ();
				s->Publish ();
			});	
		}
	}

	void LeaseSetDestination::UpdateLeaseSet ()
	{
		int numTunnels = m_Pool->GetNumInboundTunnels () + 2; // 2 backup tunnels
		if (numTunnels > i2p::data::MAX_NUM_LEASES) numTunnels = i2p::data::MAX_NUM_LEASES; // 16 tunnels maximum
		CreateNewLeaseSet (m_Pool->GetInboundTunnels (numTunnels));
	}

	bool LeaseSetDestination::SubmitSessionKey (const uint8_t * key, const uint8_t * tag)
	{
		struct
		{
			uint8_t k[32], t[32];
		} data;
		memcpy (data.k, key, 32);
		memcpy (data.t, tag, 32);
		auto s = shared_from_this ();
		m_Service.post ([s,data](void)
			{
				s->AddSessionKey (data.k, data.t);
			});
		return true;
	}

	void LeaseSetDestination::ProcessGarlicMessage (std::shared_ptr<I2NPMessage> msg)
	{
		m_Service.post (std::bind (&LeaseSetDestination::HandleGarlicMessage, shared_from_this (), msg));
	}

	void LeaseSetDestination::ProcessDeliveryStatusMessage (std::shared_ptr<I2NPMessage> msg)
	{
		m_Service.post (std::bind (&LeaseSetDestination::HandleDeliveryStatusMessage, shared_from_this (), msg));
	}

	void LeaseSetDestination::HandleI2NPMessage (const uint8_t * buf, size_t len, std::shared_ptr<i2p::tunnel::InboundTunnel> from)
	{
		uint8_t typeID = buf[I2NP_HEADER_TYPEID_OFFSET];
		switch (typeID)
		{
			case eI2NPData:
				HandleDataMessage (buf + I2NP_HEADER_SIZE, GetI2NPMessageLength(buf, len) - I2NP_HEADER_SIZE);
			break;
			case eI2NPDeliveryStatus:
				// we assume tunnel tests non-encrypted
				HandleDeliveryStatusMessage (CreateI2NPMessage (buf, GetI2NPMessageLength (buf, len), from));
			break;
			case eI2NPDatabaseStore:
				HandleDatabaseStoreMessage (buf + I2NP_HEADER_SIZE, GetI2NPMessageLength(buf, len) - I2NP_HEADER_SIZE);
			break;
			case eI2NPDatabaseSearchReply:
				HandleDatabaseSearchReplyMessage (buf + I2NP_HEADER_SIZE, GetI2NPMessageLength(buf, len) - I2NP_HEADER_SIZE);
			break;
			default:
				i2p::HandleI2NPMessage (CreateI2NPMessage (buf, GetI2NPMessageLength (buf, len), from));
		}
	}

	void LeaseSetDestination::HandleDatabaseStoreMessage (const uint8_t * buf, size_t len)
	{
		uint32_t replyToken = bufbe32toh (buf + DATABASE_STORE_REPLY_TOKEN_OFFSET);
		size_t offset = DATABASE_STORE_HEADER_SIZE;
		if (replyToken)
		{
			LogPrint (eLogInfo, "Destination: Reply token is ignored for DatabaseStore");
			offset += 36;
		}
		i2p::data::IdentHash key (buf + DATABASE_STORE_KEY_OFFSET);
		std::shared_ptr<i2p::data::LeaseSet> leaseSet;
		if (buf[DATABASE_STORE_TYPE_OFFSET] == 1) // LeaseSet
		{
			LogPrint (eLogDebug, "Destination: Remote LeaseSet");
			std::lock_guard<std::mutex> lock(m_RemoteLeaseSetsMutex);
			auto it = m_RemoteLeaseSets.find (key);
			if (it != m_RemoteLeaseSets.end ())
			{
				leaseSet = it->second;
				if (leaseSet->IsNewer (buf + offset, len - offset))
				{
					leaseSet->Update (buf + offset, len - offset);
					if (leaseSet->IsValid () && leaseSet->GetIdentHash () == key)
						LogPrint (eLogDebug, "Destination: Remote LeaseSet updated");
					else
					{
						LogPrint (eLogDebug, "Destination: Remote LeaseSet update failed");
						m_RemoteLeaseSets.erase (it);
						leaseSet = nullptr;
					}
				}
				else
					LogPrint (eLogDebug, "Destination: Remote LeaseSet is older. Not updated");
			}
			else
			{
				leaseSet = std::make_shared<i2p::data::LeaseSet> (buf + offset, len - offset);
				if (leaseSet->IsValid () && leaseSet->GetIdentHash () == key)
				{
					if (leaseSet->GetIdentHash () != GetIdentHash ())
					{
						LogPrint (eLogDebug, "Destination: New remote LeaseSet added");
						m_RemoteLeaseSets[key] = leaseSet;
					}
					else
						LogPrint (eLogDebug, "Destination: Own remote LeaseSet dropped");
				}
				else
				{
					LogPrint (eLogError, "Destination: New remote LeaseSet failed");
					leaseSet = nullptr;
				}
			}
		}
		else
			LogPrint (eLogError, "Destination: Unexpected client's DatabaseStore type ", buf[DATABASE_STORE_TYPE_OFFSET], ", dropped");

		auto it1 = m_LeaseSetRequests.find (key);
		if (it1 != m_LeaseSetRequests.end ())
		{
			it1->second->requestTimeoutTimer.cancel ();
			if (it1->second) it1->second->Complete (leaseSet);
			m_LeaseSetRequests.erase (it1);
		}
	}

	void LeaseSetDestination::HandleDatabaseSearchReplyMessage (const uint8_t * buf, size_t len)
	{
		i2p::data::IdentHash key (buf);
		int num = buf[32]; // num
		LogPrint (eLogDebug, "Destination: DatabaseSearchReply for ", key.ToBase64 (), " num=", num);
		auto it = m_LeaseSetRequests.find (key);
		if (it != m_LeaseSetRequests.end ())
		{
			auto request = it->second;
			bool found = false;
			if (request->excluded.size () < MAX_NUM_FLOODFILLS_PER_REQUEST)
			{
				for (int i = 0; i < num; i++)
			{
				i2p::data::IdentHash peerHash (buf + 33 + i*32);
				if (!request->excluded.count (peerHash) && !i2p::data::netdb.FindRouter (peerHash))
				{
					LogPrint (eLogInfo, "Destination: Found new floodfill, request it"); // TODO: recheck this message
					i2p::data::netdb.RequestDestination (peerHash);
				}
			}

				auto floodfill = i2p::data::netdb.GetClosestFloodfill (key, request->excluded);
				if (floodfill)
				{
					LogPrint (eLogInfo, "Destination: Requesting ", key.ToBase64 (), " at ", floodfill->GetIdentHash ().ToBase64 ());
					if (SendLeaseSetRequest (key, floodfill, request))
						found = true;
				}
			}
			if (!found)
			{
				LogPrint (eLogInfo, "Destination: ", key.ToBase64 (), " was not found on ", MAX_NUM_FLOODFILLS_PER_REQUEST, " floodfills");
				request->Complete (nullptr);
				m_LeaseSetRequests.erase (key);
			}
		}
		else
			LogPrint (eLogWarning, "Destination: Request for ", key.ToBase64 (), " not found");
	}

	void LeaseSetDestination::HandleDeliveryStatusMessage (std::shared_ptr<I2NPMessage> msg)
	{
		uint32_t msgID = bufbe32toh (msg->GetPayload () + DELIVERY_STATUS_MSGID_OFFSET);
		if (msgID == m_PublishReplyToken)
		{
			LogPrint (eLogDebug, "Destination: Publishing LeaseSet confirmed for ", GetIdentHash().ToBase32());
			m_ExcludedFloodfills.clear ();
			m_PublishReplyToken = 0;
			// schedule verification
			m_PublishVerificationTimer.expires_from_now (boost::posix_time::seconds(PUBLISH_VERIFICATION_TIMEOUT));
			m_PublishVerificationTimer.async_wait (std::bind (&LeaseSetDestination::HandlePublishVerificationTimer,
			shared_from_this (), std::placeholders::_1));
		}
		else
			i2p::garlic::GarlicDestination::HandleDeliveryStatusMessage (msg);
	}

	void LeaseSetDestination::SetLeaseSetUpdated ()
	{
		UpdateLeaseSet ();
	}

	void LeaseSetDestination::Publish ()
	{
		if (!m_LeaseSet || !m_Pool)
		{
			LogPrint (eLogError, "Destination: Can't publish non-existing LeaseSet");
			return;
		}
		if (m_PublishReplyToken)
		{
			LogPrint (eLogDebug, "Destination: Publishing LeaseSet is pending");
			return;
		}
		auto ts = i2p::util::GetSecondsSinceEpoch ();
		if (ts < m_LastSubmissionTime + PUBLISH_MIN_INTERVAL)
		{
			LogPrint (eLogDebug, "Destination: Publishing LeaseSet is too fast. Wait for ", PUBLISH_MIN_INTERVAL, " seconds");
			m_PublishDelayTimer.cancel ();
			m_PublishDelayTimer.expires_from_now (boost::posix_time::seconds(PUBLISH_MIN_INTERVAL));
			m_PublishDelayTimer.async_wait (std::bind (&LeaseSetDestination::HandlePublishDelayTimer,
				shared_from_this (), std::placeholders::_1));
			return;
		}
		auto outbound = m_Pool->GetNextOutboundTunnel ();
		if (!outbound)
		{
			LogPrint (eLogError, "Destination: Can't publish LeaseSet. No outbound tunnels");
			return;
		}
		auto inbound = m_Pool->GetNextInboundTunnel ();
		if (!inbound)
		{
			LogPrint (eLogError, "Destination: Can't publish LeaseSet. No inbound tunnels");
			return;
		}
		auto floodfill = i2p::data::netdb.GetClosestFloodfill (m_LeaseSet->GetIdentHash (), m_ExcludedFloodfills);
		if (!floodfill)
		{
			LogPrint (eLogError, "Destination: Can't publish LeaseSet, no more floodfills found");
			m_ExcludedFloodfills.clear ();
			return;
		}
		m_ExcludedFloodfills.insert (floodfill->GetIdentHash ());
		LogPrint (eLogDebug, "Destination: Publish LeaseSet of ", GetIdentHash ().ToBase32 ());
		RAND_bytes ((uint8_t *)&m_PublishReplyToken, 4);
		auto msg = WrapMessage (floodfill, i2p::CreateDatabaseStoreMsg (m_LeaseSet, m_PublishReplyToken, inbound));
		m_PublishConfirmationTimer.expires_from_now (boost::posix_time::seconds(PUBLISH_CONFIRMATION_TIMEOUT));
		m_PublishConfirmationTimer.async_wait (std::bind (&LeaseSetDestination::HandlePublishConfirmationTimer,
			shared_from_this (), std::placeholders::_1));
		outbound->SendTunnelDataMsg (floodfill->GetIdentHash (), 0, msg);
		m_LastSubmissionTime = ts;
	}

	void LeaseSetDestination::HandlePublishConfirmationTimer (const boost::system::error_code& ecode)
	{
		if (ecode != boost::asio::error::operation_aborted)
		{
			if (m_PublishReplyToken)
			{
				m_PublishReplyToken = 0;
				if (GetIdentity ()->GetCryptoKeyType () == i2p::data::CRYPTO_KEY_TYPE_ELGAMAL)
				{
					LogPrint (eLogWarning, "Destination: Publish confirmation was not received in ", PUBLISH_CONFIRMATION_TIMEOUT,  " seconds, will try again");
					Publish ();
				}
				else
				{
					LogPrint (eLogWarning, "Destination: Publish confirmation was not received in ", PUBLISH_CONFIRMATION_TIMEOUT,  " seconds from Java floodfill for crypto type ", (int)GetIdentity ()->GetCryptoKeyType ());
					// Java floodfill never sends confirmantion back for unknown crypto type
					// assume it successive and try to verify
					m_PublishVerificationTimer.expires_from_now (boost::posix_time::seconds(PUBLISH_VERIFICATION_TIMEOUT));
					m_PublishVerificationTimer.async_wait (std::bind (&LeaseSetDestination::HandlePublishVerificationTimer,
			shared_from_this (), std::placeholders::_1));

				}
			}
		}
	}

	void LeaseSetDestination::HandlePublishVerificationTimer (const boost::system::error_code& ecode)
	{
		if (ecode != boost::asio::error::operation_aborted)
		{
			auto s = shared_from_this ();
			RequestLeaseSet (GetIdentHash (),
				// "this" added due to bug in gcc 4.7-4.8
				[s,this](std::shared_ptr<i2p::data::LeaseSet> leaseSet)
				{
					if (leaseSet)
					{
						if (s->m_LeaseSet && *s->m_LeaseSet == *leaseSet)
						{
							// we got latest LeasetSet
							LogPrint (eLogDebug, "Destination: published LeaseSet verified for ", GetIdentHash().ToBase32());
							s->m_PublishVerificationTimer.expires_from_now (boost::posix_time::seconds(PUBLISH_REGULAR_VERIFICATION_INTERNAL));
							s->m_PublishVerificationTimer.async_wait (std::bind (&LeaseSetDestination::HandlePublishVerificationTimer, s, std::placeholders::_1));
							return;
						}
						else
							LogPrint (eLogDebug, "Destination: LeaseSet is different than just published for ", GetIdentHash().ToBase32());
					}
					else
						LogPrint (eLogWarning, "Destination: couldn't find published LeaseSet for ", GetIdentHash().ToBase32());
					// we have to publish again
					s->Publish ();
				});
		}
	}

	void LeaseSetDestination::HandlePublishDelayTimer (const boost::system::error_code& ecode)
	{
		if (ecode != boost::asio::error::operation_aborted)
			Publish ();
	}

	bool LeaseSetDestination::RequestDestination (const i2p::data::IdentHash& dest, RequestComplete requestComplete)
	{
		if (!m_Pool || !IsReady ())
		{
			if (requestComplete)
				m_Service.post ([requestComplete](void){requestComplete (nullptr);});
			return false;
		}
		m_Service.post (std::bind (&LeaseSetDestination::RequestLeaseSet, shared_from_this (), dest, requestComplete));
		return true;
	}

	void LeaseSetDestination::CancelDestinationRequest (const i2p::data::IdentHash& dest, bool notify)
	{
		auto s = shared_from_this ();
		m_Service.post ([dest, notify, s](void)
			{
				auto it = s->m_LeaseSetRequests.find (dest);
				if (it != s->m_LeaseSetRequests.end ())
				{
					auto requestComplete = it->second;
					s->m_LeaseSetRequests.erase (it);
					if (notify && requestComplete) requestComplete->Complete (nullptr);
				}
			});
	}

	void LeaseSetDestination::RequestLeaseSet (const i2p::data::IdentHash& dest, RequestComplete requestComplete)
	{
		std::set<i2p::data::IdentHash> excluded;
		auto floodfill = i2p::data::netdb.GetClosestFloodfill (dest, excluded);
		if (floodfill)
		{
			auto request = std::make_shared<LeaseSetRequest> (m_Service);
			if (requestComplete)
				request->requestComplete.push_back (requestComplete);
			auto ts = i2p::util::GetSecondsSinceEpoch ();
			auto ret = m_LeaseSetRequests.insert (std::pair<i2p::data::IdentHash, std::shared_ptr<LeaseSetRequest> >(dest,request));
			if (ret.second) // inserted
			{
				request->requestTime = ts;
				if (!SendLeaseSetRequest (dest, floodfill, request))
				{
					// request failed
					m_LeaseSetRequests.erase (ret.first);
					if (requestComplete) requestComplete (nullptr);
				}
			}
			else // duplicate
			{
				LogPrint (eLogInfo, "Destination: Request of LeaseSet ", dest.ToBase64 (), " is pending already");
				if (ts > ret.first->second->requestTime + MAX_LEASESET_REQUEST_TIMEOUT)
				{
					// something went wrong
					m_LeaseSetRequests.erase (ret.first);
					if (requestComplete) requestComplete (nullptr);
				}
				else if (requestComplete)
					ret.first->second->requestComplete.push_back (requestComplete);
			}
		}
		else
		{
			LogPrint (eLogError, "Destination: Can't request LeaseSet, no floodfills found");
			if (requestComplete) requestComplete (nullptr);
		}
	}

	bool LeaseSetDestination::SendLeaseSetRequest (const i2p::data::IdentHash& dest,
		std::shared_ptr<const i2p::data::RouterInfo>  nextFloodfill, std::shared_ptr<LeaseSetRequest> request)
	{
		if (!request->replyTunnel || !request->replyTunnel->IsEstablished ())
			request->replyTunnel = m_Pool->GetNextInboundTunnel ();
		if (!request->replyTunnel) LogPrint (eLogError, "Destination: Can't send LeaseSet request, no inbound tunnels found");
		if (!request->outboundTunnel || !request->outboundTunnel->IsEstablished ())
			request->outboundTunnel = m_Pool->GetNextOutboundTunnel ();
		if (!request->outboundTunnel) LogPrint (eLogError, "Destination: Can't send LeaseSet request, no outbound tunnels found");

		if (request->replyTunnel && request->outboundTunnel)
		{
			request->excluded.insert (nextFloodfill->GetIdentHash ());
			request->requestTimeoutTimer.cancel ();

			uint8_t replyKey[32], replyTag[32];
			RAND_bytes (replyKey, 32); // random session key
			RAND_bytes (replyTag, 32); // random session tag
			AddSessionKey (replyKey, replyTag);

			auto msg = WrapMessage (nextFloodfill,
				CreateLeaseSetDatabaseLookupMsg (dest, request->excluded,
					request->replyTunnel, replyKey, replyTag));
			request->outboundTunnel->SendTunnelDataMsg (
				{
					i2p::tunnel::TunnelMessageBlock
					{
						i2p::tunnel::eDeliveryTypeRouter,
						nextFloodfill->GetIdentHash (), 0, msg
					}
				});
			request->requestTimeoutTimer.expires_from_now (boost::posix_time::seconds(LEASESET_REQUEST_TIMEOUT));
			request->requestTimeoutTimer.async_wait (std::bind (&LeaseSetDestination::HandleRequestTimoutTimer,
				shared_from_this (), std::placeholders::_1, dest));
		}
		else
			return false;
		return true;
	}

	void LeaseSetDestination::HandleRequestTimoutTimer (const boost::system::error_code& ecode, const i2p::data::IdentHash& dest)
	{
		if (ecode != boost::asio::error::operation_aborted)
		{
			auto it = m_LeaseSetRequests.find (dest);
			if (it != m_LeaseSetRequests.end ())
			{
				bool done = false;
				uint64_t ts = i2p::util::GetSecondsSinceEpoch ();
				if (ts < it->second->requestTime + MAX_LEASESET_REQUEST_TIMEOUT)
				{
					auto floodfill = i2p::data::netdb.GetClosestFloodfill (dest, it->second->excluded);
					if (floodfill)
					{
						// reset tunnels, because one them might fail
						it->second->outboundTunnel = nullptr;
						it->second->replyTunnel = nullptr;
						done = !SendLeaseSetRequest (dest, floodfill, it->second);
					}
					else
						done = true;
				}
				else
				{
					LogPrint (eLogWarning, "Destination: ", dest.ToBase64 (), " was not found within ",  MAX_LEASESET_REQUEST_TIMEOUT, " seconds");
					done = true;
				}

				if (done)
				{
					auto requestComplete = it->second;
					m_LeaseSetRequests.erase (it);
					if (requestComplete) requestComplete->Complete (nullptr);
				}
			}
		}
	}

	void LeaseSetDestination::HandleCleanupTimer (const boost::system::error_code& ecode)
	{
		if (ecode != boost::asio::error::operation_aborted)
		{
			CleanupExpiredTags ();
			CleanupRemoteLeaseSets ();
			CleanupDestination ();
			m_CleanupTimer.expires_from_now (boost::posix_time::minutes (DESTINATION_CLEANUP_TIMEOUT));
			m_CleanupTimer.async_wait (std::bind (&LeaseSetDestination::HandleCleanupTimer,
				shared_from_this (), std::placeholders::_1));
		}
	}

	void LeaseSetDestination::CleanupRemoteLeaseSets ()
	{
		auto ts = i2p::util::GetMillisecondsSinceEpoch ();
		std::lock_guard<std::mutex> lock(m_RemoteLeaseSetsMutex);
		for (auto it = m_RemoteLeaseSets.begin (); it != m_RemoteLeaseSets.end ();)
		{
			if (it->second->IsEmpty () || ts > it->second->GetExpirationTime ()) // leaseset expired
			{
				LogPrint (eLogWarning, "Destination: Remote LeaseSet ", it->second->GetIdentHash ().ToBase64 (), " expired");
				it = m_RemoteLeaseSets.erase (it);
			}
			else
				++it;
		}
	}

	ClientDestination::ClientDestination (const i2p::data::PrivateKeys& keys, bool isPublic, const std::map<std::string, std::string> * params):
		LeaseSetDestination (isPublic, params), m_Keys (keys), m_StreamingAckDelay (DEFAULT_INITIAL_ACK_DELAY),
		m_DatagramDestination (nullptr), m_RefCounter (0),
		m_ReadyChecker(GetService())
	{
		if (isPublic)
			PersistTemporaryKeys ();
		else
			i2p::data::PrivateKeys::GenerateCryptoKeyPair(GetIdentity ()->GetCryptoKeyType (),
				m_EncryptionPrivateKey, m_EncryptionPublicKey);
		m_Decryptor = m_Keys.CreateDecryptor (m_EncryptionPrivateKey);
		if (isPublic)
			LogPrint (eLogInfo, "Destination: Local address ", GetIdentHash().ToBase32 (), " created");

		// extract streaming params
		if (params)
		{
			auto it = params->find (I2CP_PARAM_STREAMING_INITIAL_ACK_DELAY);
			if (it != params->end ())
				m_StreamingAckDelay = std::stoi(it->second);
		}
	}

	ClientDestination::~ClientDestination ()
	{
	}

	bool ClientDestination::Start ()
	{
		if (LeaseSetDestination::Start ())
		{
			m_StreamingDestination = std::make_shared<i2p::stream::StreamingDestination> (GetSharedFromThis ()); // TODO:
			m_StreamingDestination->Start ();
			for (auto& it: m_StreamingDestinationsByPorts)
				it.second->Start ();
			return true;
		}
		else
			return false;
	}

	bool ClientDestination::Stop ()
	{
		if (LeaseSetDestination::Stop ())
		{
			m_ReadyChecker.cancel();
			m_StreamingDestination->Stop ();
			//m_StreamingDestination->SetOwner (nullptr);
			m_StreamingDestination = nullptr;
			for (auto& it: m_StreamingDestinationsByPorts)
			{
				it.second->Stop ();
				//it.second->SetOwner (nullptr);
			}
			m_StreamingDestinationsByPorts.clear ();
			if (m_DatagramDestination)
			{
				delete m_DatagramDestination;
				m_DatagramDestination = nullptr;
			}
			return true;
		}
		else
			return false;
	}

#ifdef I2LUA
	void ClientDestination::Ready(ReadyPromise & p)
	{
		ScheduleCheckForReady(&p);
	}

	void ClientDestination::ScheduleCheckForReady(ReadyPromise * p)
	{
		// tick every 100ms
		m_ReadyChecker.expires_from_now(boost::posix_time::milliseconds(100));
		m_ReadyChecker.async_wait([&, p] (const boost::system::error_code & ecode) {
			HandleCheckForReady(ecode, p);
		});
	}

	void ClientDestination::HandleCheckForReady(const boost::system::error_code & ecode, ReadyPromise * p)
	{
		if(ecode) // error happened
			p->set_value(nullptr);
		else if(IsReady()) // we are ready
			p->set_value(std::shared_ptr<ClientDestination>(this));
		else // we are not ready
			ScheduleCheckForReady(p);
	}
#endif

	void ClientDestination::HandleDataMessage (const uint8_t * buf, size_t len)
	{
		uint32_t length = bufbe32toh (buf);
		if(length > len - 4)
		{
			LogPrint(eLogError, "Destination: Data message length ", length, " exceeds buffer length ", len);
			return;
		}
		buf += 4;
		// we assume I2CP payload
		uint16_t fromPort = bufbe16toh (buf + 4), // source
			toPort = bufbe16toh (buf + 6); // destination
		switch (buf[9])
		{
			case PROTOCOL_TYPE_STREAMING:
			{
				// streaming protocol
				auto dest = GetStreamingDestination (toPort);
				if (dest)
					dest->HandleDataMessagePayload (buf, length);
				else
					LogPrint (eLogError, "Destination: Missing streaming destination");
			}
			break;
			case PROTOCOL_TYPE_DATAGRAM:
				// datagram protocol
				if (m_DatagramDestination)
					m_DatagramDestination->HandleDataMessagePayload (fromPort, toPort, buf, length);
				else
					LogPrint (eLogError, "Destination: Missing datagram destination");
			break;
			default:
				LogPrint (eLogError, "Destination: Data: unexpected protocol ", buf[9]);
		}
	}

	void ClientDestination::CreateStream (StreamRequestComplete streamRequestComplete, const i2p::data::IdentHash& dest, int port)
	{
		if (!streamRequestComplete)
		{
			LogPrint (eLogError, "Destination: request callback is not specified in CreateStream");
			return;
		}
		auto leaseSet = FindLeaseSet (dest);
		if (leaseSet)
			streamRequestComplete(CreateStream (leaseSet, port));
		else
		{
			auto s = GetSharedFromThis ();
			RequestDestination (dest,
				[s, streamRequestComplete, port](std::shared_ptr<i2p::data::LeaseSet> ls)
				{
					if (ls)
						streamRequestComplete(s->CreateStream (ls, port));
					else
						streamRequestComplete (nullptr);
				});
		}
	}

	std::shared_ptr<i2p::stream::Stream> ClientDestination::CreateStream (std::shared_ptr<const i2p::data::LeaseSet> remote, int port)
	{
		if (m_StreamingDestination)
			return m_StreamingDestination->CreateNewOutgoingStream (remote, port);
		else
			return nullptr;
	}

	std::shared_ptr<i2p::stream::StreamingDestination> ClientDestination::GetStreamingDestination (int port) const
	{
		if (port)
		{
			auto it = m_StreamingDestinationsByPorts.find (port);
			if (it != m_StreamingDestinationsByPorts.end ())
				return it->second;
		}
		// if port is zero or not found, use default destination
		return m_StreamingDestination;
	}

	void ClientDestination::AcceptStreams (const i2p::stream::StreamingDestination::Acceptor& acceptor)
	{
		if (m_StreamingDestination)
			m_StreamingDestination->SetAcceptor (acceptor);
	}

	void ClientDestination::StopAcceptingStreams ()
	{
		if (m_StreamingDestination)
			m_StreamingDestination->ResetAcceptor ();
	}

	bool ClientDestination::IsAcceptingStreams () const
	{
		if (m_StreamingDestination)
			return m_StreamingDestination->IsAcceptorSet ();
		return false;
	}

	void ClientDestination::AcceptOnce (const i2p::stream::StreamingDestination::Acceptor& acceptor)
	{
		if (m_StreamingDestination)
			m_StreamingDestination->AcceptOnce (acceptor);
	}

	std::shared_ptr<i2p::stream::StreamingDestination> ClientDestination::CreateStreamingDestination (int port, bool gzip)
	{
		auto dest = std::make_shared<i2p::stream::StreamingDestination> (GetSharedFromThis (), port, gzip);
		if (port)
			m_StreamingDestinationsByPorts[port] = dest;
		else // update default
			m_StreamingDestination = dest;
		return dest;
	}

  i2p::datagram::DatagramDestination * ClientDestination::CreateDatagramDestination ()
	{
		if (m_DatagramDestination == nullptr)
			m_DatagramDestination = new i2p::datagram::DatagramDestination (GetSharedFromThis ());
		return m_DatagramDestination;
	}

	std::vector<std::shared_ptr<const i2p::stream::Stream> > ClientDestination::GetAllStreams () const
	{
		std::vector<std::shared_ptr<const i2p::stream::Stream> > ret;
		if (m_StreamingDestination)
		{
			for (auto& it: m_StreamingDestination->GetStreams ())
				ret.push_back (it.second);
		}
		for (auto& it: m_StreamingDestinationsByPorts)
			for (auto& it1: it.second->GetStreams ())
				ret.push_back (it1.second);
		return ret;
	}

	void ClientDestination::PersistTemporaryKeys ()
	{
		std::string ident = GetIdentHash().ToBase32();
		std::string path  = i2p::fs::DataDirPath("destinations", (ident + ".dat"));
		std::ifstream f(path, std::ifstream::binary);

		if (f) {
			f.read ((char *)m_EncryptionPublicKey,  256);
			f.read ((char *)m_EncryptionPrivateKey, 256);
			return;
		}

		LogPrint (eLogInfo, "Destination: Creating new temporary keys for address ", ident, ".b32.i2p");
		i2p::data::PrivateKeys::GenerateCryptoKeyPair(GetIdentity ()->GetCryptoKeyType (),
				m_EncryptionPrivateKey, m_EncryptionPublicKey);

		std::ofstream f1 (path, std::ofstream::binary | std::ofstream::out);
		if (f1) {
			f1.write ((char *)m_EncryptionPublicKey,  256);
			f1.write ((char *)m_EncryptionPrivateKey, 256);
			return;
		}
		LogPrint(eLogError, "Destinations: Can't save keys to ", path);
	}

	void ClientDestination::CreateNewLeaseSet (std::vector<std::shared_ptr<i2p::tunnel::InboundTunnel> > tunnels)
	{
		auto leaseSet = new i2p::data::LocalLeaseSet (GetIdentity (), m_EncryptionPublicKey, tunnels);
		// sign
		Sign (leaseSet->GetBuffer (), leaseSet->GetBufferLen () - leaseSet->GetSignatureLen (), leaseSet->GetSignature ()); // TODO
		SetLeaseSet (leaseSet);
	}

	void ClientDestination::CleanupDestination ()
	{
		if (m_DatagramDestination) m_DatagramDestination->CleanUp ();
	}

	bool ClientDestination::Decrypt (const uint8_t * encrypted, uint8_t * data, BN_CTX * ctx) const
	{
		if (m_Decryptor)
			return m_Decryptor->Decrypt (encrypted, data, ctx, true);
		else
			LogPrint (eLogError, "Destinations: decryptor is not set");
		return false;
	}
}
}