monero/contrib/epee/include/net/abstract_tcp_server2.inl

/**
@file
@author from CrypoNote (see copyright below; Andrey N. Sabelnikov)
@monero rfree
@brief the connection templated-class for one peer connection
*/
// Copyright (c) 2006-2013, Andrey N. Sabelnikov, www.sabelnikov.net
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of the Andrey N. Sabelnikov nor the
// names of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER  BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 



#include <boost/foreach.hpp>
#include <boost/uuid/random_generator.hpp>
#include <boost/chrono.hpp>
#include <boost/utility/value_init.hpp>
#include <boost/asio/deadline_timer.hpp>
#include <boost/date_time/posix_time/posix_time.hpp> // TODO
#include <boost/thread/condition_variable.hpp> // TODO
#include <boost/make_shared.hpp>
#include <boost/thread.hpp>
#include "warnings.h"
#include "string_tools_lexical.h"
#include "misc_language.h"

#include <sstream>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <random>

#undef MONERO_DEFAULT_LOG_CATEGORY
#define MONERO_DEFAULT_LOG_CATEGORY "net"

#define AGGRESSIVE_TIMEOUT_THRESHOLD 120 // sockets
#define NEW_CONNECTION_TIMEOUT_LOCAL 1200000 // 2 minutes
#define NEW_CONNECTION_TIMEOUT_REMOTE 10000 // 10 seconds
#define DEFAULT_TIMEOUT_MS_LOCAL 1800000 // 30 minutes
#define DEFAULT_TIMEOUT_MS_REMOTE 300000 // 5 minutes
#define TIMEOUT_EXTRA_MS_PER_BYTE 0.2


namespace epee
{
namespace net_utils
{
  template<typename T>
  T& check_and_get(std::shared_ptr<T>& ptr)
  {
    CHECK_AND_ASSERT_THROW_MES(bool(ptr), "shared_state cannot be null");
    return *ptr;
  }

  /************************************************************************/
  /*                                                                      */
  /************************************************************************/
  template<class t_protocol_handler>
  connection<t_protocol_handler>::connection( boost::asio::io_service& io_service,
                std::shared_ptr<shared_state> state,
		t_connection_type connection_type,
		ssl_support_t ssl_support
	)
	: connection(boost::asio::ip::tcp::socket{io_service}, std::move(state), connection_type, ssl_support)
  {
  }

  template<class t_protocol_handler>
  connection<t_protocol_handler>::connection( boost::asio::ip::tcp::socket&& sock,
                std::shared_ptr<shared_state> state,
		t_connection_type connection_type,
		ssl_support_t ssl_support
	)
	: 
		connection_basic(std::move(sock), state, ssl_support),
		m_protocol_handler(this, check_and_get(state), context),
		buffer_ssl_init_fill(0),
		m_connection_type( connection_type ),
		m_throttle_speed_in("speed_in", "throttle_speed_in"),
		m_throttle_speed_out("speed_out", "throttle_speed_out"),
		m_timer(GET_IO_SERVICE(socket_)),
		m_local(false),
		m_ready_to_close(false)
  {
    MDEBUG("test, connection constructor set m_connection_type="<<m_connection_type);
  }

  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  connection<t_protocol_handler>::~connection() noexcept(false)
  {
    if(!m_was_shutdown)
    {
      _dbg3("[sock " << socket().native_handle() << "] Socket destroyed without shutdown.");
      shutdown();
    }

    _dbg3("[sock " << socket().native_handle() << "] Socket destroyed");
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  boost::shared_ptr<connection<t_protocol_handler> > connection<t_protocol_handler>::safe_shared_from_this()
  {
    try
    {
      return connection<t_protocol_handler>::shared_from_this();
    }
    catch (const boost::bad_weak_ptr&)
    {
      // It happens when the connection is being deleted
      return boost::shared_ptr<connection<t_protocol_handler> >();
    }
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::start(bool is_income, bool is_multithreaded)
  {
    TRY_ENTRY();

    boost::system::error_code ec;
    auto remote_ep = socket().remote_endpoint(ec);
    CHECK_AND_NO_ASSERT_MES(!ec, false, "Failed to get remote endpoint: " << ec.message() << ':' << ec.value());
    CHECK_AND_NO_ASSERT_MES(remote_ep.address().is_v4() || remote_ep.address().is_v6(), false, "only IPv4 and IPv6 supported here");

    if (remote_ep.address().is_v4())
    {
      const unsigned long ip_ = boost::asio::detail::socket_ops::host_to_network_long(remote_ep.address().to_v4().to_ulong());
      return start(is_income, is_multithreaded, ipv4_network_address{uint32_t(ip_), remote_ep.port()});
    }
    else
    {
      const auto ip_ = remote_ep.address().to_v6();
      return start(is_income, is_multithreaded, ipv6_network_address{ip_, remote_ep.port()});
    }
    CATCH_ENTRY_L0("connection<t_protocol_handler>::start()", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::start(bool is_income, bool is_multithreaded, network_address real_remote)
  {
    TRY_ENTRY();

    // Use safe_shared_from_this, because of this is public method and it can be called on the object being deleted
    auto self = safe_shared_from_this();
    if(!self)
      return false;

    m_is_multithreaded = is_multithreaded;
    m_local = real_remote.is_loopback() || real_remote.is_local();

    // create a random uuid, we don't need crypto strength here
    const boost::uuids::uuid random_uuid = boost::uuids::random_generator()();

    context = t_connection_context{};
    bool ssl = m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled;
    context.set_details(random_uuid, std::move(real_remote), is_income, ssl);

    boost::system::error_code ec;
    auto local_ep = socket().local_endpoint(ec);
    CHECK_AND_NO_ASSERT_MES(!ec, false, "Failed to get local endpoint: " << ec.message() << ':' << ec.value());

    _dbg3("[sock " << socket_.native_handle() << "] new connection from " << print_connection_context_short(context) <<
      " to " << local_ep.address().to_string() << ':' << local_ep.port() <<
      ", total sockets objects " << get_state().sock_count);

    if(static_cast<shared_state&>(get_state()).pfilter && !static_cast<shared_state&>(get_state()).pfilter->is_remote_host_allowed(context.m_remote_address))
    {
      _dbg2("[sock " << socket().native_handle() << "] host denied " << context.m_remote_address.host_str() << ", shutdowning connection");
      close();
      return false;
    }

    m_host = context.m_remote_address.host_str();
    try { host_count(m_host, 1); } catch(...) { /* ignore */ }

    m_protocol_handler.after_init_connection();

    reset_timer(boost::posix_time::milliseconds(m_local ? NEW_CONNECTION_TIMEOUT_LOCAL : NEW_CONNECTION_TIMEOUT_REMOTE), false);

    // first read on the raw socket to detect SSL for the server
    buffer_ssl_init_fill = 0;
    if (is_income && m_ssl_support != epee::net_utils::ssl_support_t::e_ssl_support_disabled)
      socket().async_receive(boost::asio::buffer(buffer_),
        strand_.wrap(
          std::bind(&connection<t_protocol_handler>::handle_receive, self,
            std::placeholders::_1,
            std::placeholders::_2)));
    else
      async_read_some(boost::asio::buffer(buffer_),
        strand_.wrap(
          std::bind(&connection<t_protocol_handler>::handle_read, self,
            std::placeholders::_1,
            std::placeholders::_2)));
#if !defined(_WIN32) || !defined(__i686)
	// not supported before Windows7, too lazy for runtime check
	// Just exclude for 32bit windows builds
	//set ToS flag
	int tos = get_tos_flag();
	boost::asio::detail::socket_option::integer< IPPROTO_IP, IP_TOS >
	optionTos( tos );
    socket().set_option( optionTos );
	//_dbg1("Set ToS flag to " << tos);
#endif
	
	boost::asio::ip::tcp::no_delay noDelayOption(false);
	socket().set_option(noDelayOption);
	
    return true;

    CATCH_ENTRY_L0("connection<t_protocol_handler>::start()", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::request_callback()
  {
    TRY_ENTRY();
    _dbg2("[" << print_connection_context_short(context) << "] request_callback");
    // Use safe_shared_from_this, because of this is public method and it can be called on the object being deleted
    auto self = safe_shared_from_this();
    if(!self)
      return false;

    strand_.post(boost::bind(&connection<t_protocol_handler>::call_back_starter, self));
    CATCH_ENTRY_L0("connection<t_protocol_handler>::request_callback()", false);
    return true;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  boost::asio::io_service& connection<t_protocol_handler>::get_io_service()
  {
    return GET_IO_SERVICE(socket());
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::add_ref()
  {
    TRY_ENTRY();

    // Use safe_shared_from_this, because of this is public method and it can be called on the object being deleted
    auto self = safe_shared_from_this();
    if(!self)
      return false;
    //_dbg3("[sock " << socket().native_handle() << "] add_ref, m_peer_number=" << mI->m_peer_number);
    CRITICAL_REGION_LOCAL(self->m_self_refs_lock);
    //_dbg3("[sock " << socket().native_handle() << "] add_ref 2, m_peer_number=" << mI->m_peer_number);
    ++m_reference_count;
    m_self_ref = std::move(self);
    return true;
    CATCH_ENTRY_L0("connection<t_protocol_handler>::add_ref()", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::release()
  {
    TRY_ENTRY();
    boost::shared_ptr<connection<t_protocol_handler> >  back_connection_copy;
    LOG_TRACE_CC(context, "[sock " << socket().native_handle() << "] release");
    CRITICAL_REGION_BEGIN(m_self_refs_lock);
    CHECK_AND_ASSERT_MES(m_reference_count, false, "[sock " << socket().native_handle() << "] m_reference_count already at 0 at connection<t_protocol_handler>::release() call");
    // is this the last reference?
    if (--m_reference_count == 0) {
        // move the held reference to a local variable, keeping the object alive until the function terminates
        std::swap(back_connection_copy, m_self_ref);
    }
    CRITICAL_REGION_END();
    return true;
    CATCH_ENTRY_L0("connection<t_protocol_handler>::release()", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void connection<t_protocol_handler>::call_back_starter()
  {
    TRY_ENTRY();
    _dbg2("[" << print_connection_context_short(context) << "] fired_callback");
    m_protocol_handler.handle_qued_callback();
    CATCH_ENTRY_L0("connection<t_protocol_handler>::call_back_starter()", void());
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void connection<t_protocol_handler>::save_dbg_log()
  {
    std::string address, port;
    boost::system::error_code e;

    boost::asio::ip::tcp::endpoint endpoint = socket().remote_endpoint(e);
    if (e)
    {
      address = "<not connected>";
      port = "<not connected>";
    }
    else
    {
      address = endpoint.address().to_string();
      port = boost::lexical_cast<std::string>(endpoint.port());
    }
    MDEBUG(" connection type " << to_string( m_connection_type ) << " "
        << socket().local_endpoint().address().to_string() << ":" << socket().local_endpoint().port()
        << " <--> " << context.m_remote_address.str() << " (via " << address << ":" << port << ")");
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void connection<t_protocol_handler>::handle_read(const boost::system::error_code& e,
    std::size_t bytes_transferred)
  {
    TRY_ENTRY();
    //_info("[sock " << socket().native_handle() << "] Async read calledback.");
    
    if (m_was_shutdown)
        return;

    if (!e)
    {
        double current_speed_down;
		{
			CRITICAL_REGION_LOCAL(m_throttle_speed_in_mutex);
			m_throttle_speed_in.handle_trafic_exact(bytes_transferred);
			current_speed_down = m_throttle_speed_in.get_current_speed();
		}
        context.m_current_speed_down = current_speed_down;
        context.m_max_speed_down = std::max(context.m_max_speed_down, current_speed_down);
    
    {
			CRITICAL_REGION_LOCAL(	epee::net_utils::network_throttle_manager::network_throttle_manager::m_lock_get_global_throttle_in );
			epee::net_utils::network_throttle_manager::network_throttle_manager::get_global_throttle_in().handle_trafic_exact(bytes_transferred);
		}

		double delay=0; // will be calculated - how much we should sleep to obey speed limit etc


		if (speed_limit_is_enabled()) {
			do // keep sleeping if we should sleep
			{
				{ //_scope_dbg1("CRITICAL_REGION_LOCAL");
					CRITICAL_REGION_LOCAL(	epee::net_utils::network_throttle_manager::m_lock_get_global_throttle_in );
					delay = epee::net_utils::network_throttle_manager::get_global_throttle_in().get_sleep_time_after_tick( bytes_transferred );
				}

				if (m_was_shutdown)
					return;
				
				delay *= 0.5;
				long int ms = (long int)(delay * 100);
				if (ms > 0) {
					reset_timer(boost::posix_time::milliseconds(ms + 1), true);
					boost::this_thread::sleep_for(boost::chrono::milliseconds(ms));
				}
			} while(delay > 0);
		} // any form of sleeping
		
      //_info("[sock " << socket().native_handle() << "] RECV " << bytes_transferred);
      logger_handle_net_read(bytes_transferred);
      context.m_last_recv = time(NULL);
      context.m_recv_cnt += bytes_transferred;
      m_ready_to_close = false;
      bool recv_res = m_protocol_handler.handle_recv(buffer_.data(), bytes_transferred);
      if(!recv_res)
      {  
        //_info("[sock " << socket().native_handle() << "] protocol_want_close");
        //some error in protocol, protocol handler ask to close connection
        m_want_close_connection = true;
        bool do_shutdown = false;
        CRITICAL_REGION_BEGIN(m_send_que_lock);
        if(!m_send_que.size())
          do_shutdown = true;
        CRITICAL_REGION_END();
        if(do_shutdown)
          shutdown();
      }else
      {
        reset_timer(get_timeout_from_bytes_read(bytes_transferred), false);
        async_read_some(boost::asio::buffer(buffer_),
          strand_.wrap(
            boost::bind(&connection<t_protocol_handler>::handle_read, connection<t_protocol_handler>::shared_from_this(),
              boost::asio::placeholders::error,
              boost::asio::placeholders::bytes_transferred)));
        //_info("[sock " << socket().native_handle() << "]Async read requested.");
      }
    }else
    {
      _dbg3("[sock " << socket().native_handle() << "] Some not success at read: " << e.message() << ':' << e.value());
      if(e.value() != 2)
      {
        _dbg3("[sock " << socket().native_handle() << "] Some problems at read: " << e.message() << ':' << e.value());
        shutdown();
      }
      else
      {
        _dbg3("[sock " << socket().native_handle() << "] peer closed connection");
        bool do_shutdown = false;
        CRITICAL_REGION_BEGIN(m_send_que_lock);
        if(!m_send_que.size())
          do_shutdown = true;
        CRITICAL_REGION_END();
        if (m_ready_to_close || do_shutdown)
          shutdown();
      }
      m_ready_to_close = true;
    }
    // If an error occurs then no new asynchronous operations are started. This
    // means that all shared_ptr references to the connection object will
    // disappear and the object will be destroyed automatically after this
    // handler returns. The connection class's destructor closes the socket.
    CATCH_ENTRY_L0("connection<t_protocol_handler>::handle_read", void());
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void connection<t_protocol_handler>::handle_receive(const boost::system::error_code& e,
    std::size_t bytes_transferred)
  {
    TRY_ENTRY();

    if (m_was_shutdown) return;

    if (e)
    {
      // offload the error case
      handle_read(e, bytes_transferred);
      return;
    }

    buffer_ssl_init_fill += bytes_transferred;
    MTRACE("we now have " << buffer_ssl_init_fill << "/" << get_ssl_magic_size() << " bytes needed to detect SSL");
    if (buffer_ssl_init_fill < get_ssl_magic_size())
    {
      socket().async_receive(boost::asio::buffer(buffer_.data() + buffer_ssl_init_fill, buffer_.size() - buffer_ssl_init_fill),
        strand_.wrap(
          boost::bind(&connection<t_protocol_handler>::handle_receive, connection<t_protocol_handler>::shared_from_this(),
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred)));
      return;
    }

    // detect SSL
    if (m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
    {
      if (is_ssl((const unsigned char*)buffer_.data(), buffer_ssl_init_fill))
      {
        MDEBUG("That looks like SSL");
        m_ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_enabled; // read/write to the SSL socket
      }
      else
      {
        MDEBUG("That does not look like SSL");
        m_ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_disabled; // read/write to the raw socket
      }
    }

    if (m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled)
    {
      // Handshake
      if (!handshake(boost::asio::ssl::stream_base::server, boost::asio::const_buffer(buffer_.data(), buffer_ssl_init_fill)))
      {
        MERROR("SSL handshake failed");
        m_want_close_connection = true;
        m_ready_to_close = true;
        bool do_shutdown = false;
        CRITICAL_REGION_BEGIN(m_send_que_lock);
        if(!m_send_que.size())
          do_shutdown = true;
        CRITICAL_REGION_END();
        if(do_shutdown)
          shutdown();
        return;
      }
    }
    else
    {
      handle_read(e, buffer_ssl_init_fill);
      return;
    }

    async_read_some(boost::asio::buffer(buffer_),
      strand_.wrap(
        boost::bind(&connection<t_protocol_handler>::handle_read, connection<t_protocol_handler>::shared_from_this(),
          boost::asio::placeholders::error,
          boost::asio::placeholders::bytes_transferred)));

    // If an error occurs then no new asynchronous operations are started. This
    // means that all shared_ptr references to the connection object will
    // disappear and the object will be destroyed automatically after this
    // handler returns. The connection class's destructor closes the socket.
    CATCH_ENTRY_L0("connection<t_protocol_handler>::handle_receive", void());
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::call_run_once_service_io()
  {
    TRY_ENTRY();
    if(!m_is_multithreaded)
    {
      //single thread model, we can wait in blocked call
      size_t cnt = GET_IO_SERVICE(socket()).run_one();
      if(!cnt)//service is going to quit
        return false;
    }else
    {
      //multi thread model, we can't(!) wait in blocked call
      //so we make non blocking call and releasing CPU by calling sleep(0); 
      //if no handlers were called
      //TODO: Maybe we need to have have critical section + event + callback to upper protocol to
      //ask it inside(!) critical region if we still able to go in event wait...
      size_t cnt = GET_IO_SERVICE(socket()).poll_one();
      if(!cnt)
        misc_utils::sleep_no_w(1);
    }
    
    return true;
    CATCH_ENTRY_L0("connection<t_protocol_handler>::call_run_once_service_io", false);
  }
  //---------------------------------------------------------------------------------
    template<class t_protocol_handler>
  bool connection<t_protocol_handler>::do_send(byte_slice message) {
    TRY_ENTRY();

    // Use safe_shared_from_this, because of this is public method and it can be called on the object being deleted
    auto self = safe_shared_from_this();
    if (!self) return false;
    if (m_was_shutdown) return false;
		// TODO avoid copy

		std::uint8_t const* const message_data = message.data();
		const std::size_t message_size = message.size();

		const double factor = 32; // TODO config
		typedef long long signed int t_safe; // my t_size to avoid any overunderflow in arithmetic
		const t_safe chunksize_good = (t_safe)( 1024 * std::max(1.0,factor) );
        const t_safe chunksize_max = chunksize_good * 2 ;
		const bool allow_split = (m_connection_type == e_connection_type_RPC) ? false : true; // do not split RPC data

        CHECK_AND_ASSERT_MES(! (chunksize_max<0), false, "Negative chunksize_max" ); // make sure it is unsigned before removin sign with cast:
        long long unsigned int chunksize_max_unsigned = static_cast<long long unsigned int>( chunksize_max ) ;

        if (allow_split && (message_size > chunksize_max_unsigned)) {
			{ // LOCK: chunking
    		epee::critical_region_t<decltype(m_chunking_lock)> send_guard(m_chunking_lock); // *** critical *** 

				MDEBUG("do_send() will SPLIT into small chunks, from packet="<<message_size<<" B for ptr="<<(const void*)message_data);
				// 01234567890 
				// ^^^^        (pos=0, len=4)     ;   pos:=pos+len, pos=4
				//     ^^^^    (pos=4, len=4)     ;   pos:=pos+len, pos=8
				//         ^^^ (pos=8, len=4)    ;   

				// const size_t bufsize = chunksize_good; // TODO safecast
				// char* buf = new char[ bufsize ];

				bool all_ok = true;
				while (!message.empty()) {
					byte_slice chunk = message.take_slice(chunksize_good);

					MDEBUG("chunk_start="<<(void*)chunk.data()<<" ptr="<<(const void*)message_data<<" pos="<<(chunk.data() - message_data));
					MDEBUG("part of " << message.size() << ": pos="<<(chunk.data() - message_data) << " len="<<chunk.size());

					bool ok = do_send_chunk(std::move(chunk)); // <====== ***

					all_ok = all_ok && ok;
					if (!all_ok) {
						MDEBUG("do_send() DONE ***FAILED*** from packet="<<message_size<<" B for ptr="<<(const void*)message_data);
						MDEBUG("do_send() SEND was aborted in middle of big package - this is mostly harmless "
							<< " (e.g. peer closed connection) but if it causes trouble tell us at #monero-dev. " << message_size);
						return false; // partial failure in sending
					}
					// (in catch block, or uniq pointer) delete buf;
				} // each chunk

				MDEBUG("do_send() DONE SPLIT from packet="<<message_size<<" B for ptr="<<(const void*)message_data);

                MDEBUG("do_send() m_connection_type = " << m_connection_type);

				return all_ok; // done - e.g. queued - all the chunks of current do_send call
			} // LOCK: chunking
		} // a big block (to be chunked) - all chunks
		else { // small block
			return do_send_chunk(std::move(message)); // just send as 1 big chunk
		}

    CATCH_ENTRY_L0("connection<t_protocol_handler>::do_send", false);
	} // do_send()

  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::do_send_chunk(byte_slice chunk)
  {
    TRY_ENTRY();
    // Use safe_shared_from_this, because of this is public method and it can be called on the object being deleted
    auto self = safe_shared_from_this();
    if(!self)
      return false;
    if(m_was_shutdown)
      return false;
    double current_speed_up;
    {
		CRITICAL_REGION_LOCAL(m_throttle_speed_out_mutex);
		m_throttle_speed_out.handle_trafic_exact(chunk.size());
		current_speed_up = m_throttle_speed_out.get_current_speed();
	}
    context.m_current_speed_up = current_speed_up;
    context.m_max_speed_up = std::max(context.m_max_speed_up, current_speed_up);

    //_info("[sock " << socket().native_handle() << "] SEND " << cb);
    context.m_last_send = time(NULL);
    context.m_send_cnt += chunk.size();
    //some data should be wrote to stream
    //request complete
    
    // No sleeping here; sleeping is done once and for all in "handle_write"

    m_send_que_lock.lock(); // *** critical ***
    epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){m_send_que_lock.unlock();});

    long int retry=0;
    const long int retry_limit = 5*4;
    while (m_send_que.size() > ABSTRACT_SERVER_SEND_QUE_MAX_COUNT)
    {
        retry++;

        /* if ( ::cryptonote::core::get_is_stopping() ) { // TODO re-add fast stop
            _fact("ABORT queue wait due to stopping");
            return false; // aborted
        }*/

        using engine = std::mt19937;

        engine rng;
        std::random_device dev;
        std::seed_seq::result_type rand[engine::state_size]{};  // Use complete bit space

        std::generate_n(rand, engine::state_size, std::ref(dev));
        std::seed_seq seed(rand, rand + engine::state_size);
        rng.seed(seed);

        long int ms = 250 + (rng() % 50);
        MDEBUG("Sleeping because QUEUE is FULL, in " << __FUNCTION__ << " for " << ms << " ms before packet_size="<<chunk.size()); // XXX debug sleep
        m_send_que_lock.unlock();
        boost::this_thread::sleep(boost::posix_time::milliseconds( ms ) );
        m_send_que_lock.lock();
        _dbg1("sleep for queue: " << ms);
	if (m_was_shutdown)
		return false;

        if (retry > retry_limit) {
            MWARNING("send que size is more than ABSTRACT_SERVER_SEND_QUE_MAX_COUNT(" << ABSTRACT_SERVER_SEND_QUE_MAX_COUNT << "), shutting down connection");
            shutdown();
            return false;
        }
    }

    m_send_que.push_back(std::move(chunk));

    if(m_send_que.size() > 1)
    { // active operation should be in progress, nothing to do, just wait last operation callback
        auto size_now = m_send_que.back().size();
        MDEBUG("do_send_chunk() NOW just queues: packet="<<size_now<<" B, is added to queue-size="<<m_send_que.size());
        //do_send_handler_delayed( ptr , size_now ); // (((H))) // empty function
      
      LOG_TRACE_CC(context, "[sock " << socket().native_handle() << "] Async send requested " << m_send_que.front().size());
    }
    else
    { // no active operation

        if(m_send_que.size()!=1)
        {
            _erro("Looks like no active operations, but send que size != 1!!");
            return false;
        }

        auto size_now = m_send_que.front().size();
        MDEBUG("do_send_chunk() NOW SENSD: packet="<<size_now<<" B");
        if (speed_limit_is_enabled())
			do_send_handler_write( m_send_que.back().data(), m_send_que.back().size() ); // (((H)))

        CHECK_AND_ASSERT_MES( size_now == m_send_que.front().size(), false, "Unexpected queue size");
        reset_timer(get_default_timeout(), false);
            async_write(boost::asio::buffer(m_send_que.front().data(), size_now ) ,
                                 strand_.wrap(
                                 std::bind(&connection<t_protocol_handler>::handle_write, self, std::placeholders::_1, std::placeholders::_2)
                                 )
                                 );
        //_dbg3("(chunk): " << size_now);
        //logger_handle_net_write(size_now);
        //_info("[sock " << socket().native_handle() << "] Async send requested " << m_send_que.front().size());
    }
    
    //do_send_handler_stop( ptr , cb ); // empty function

    return true;

    CATCH_ENTRY_L0("connection<t_protocol_handler>::do_send_chunk", false);
  } // do_send_chunk
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  boost::posix_time::milliseconds connection<t_protocol_handler>::get_default_timeout()
  {
    unsigned count;
    try { count = host_count(m_host); } catch (...) { count = 0; }
    const unsigned shift = get_state().sock_count > AGGRESSIVE_TIMEOUT_THRESHOLD ? std::min(std::max(count, 1u) - 1, 8u) : 0;
    boost::posix_time::milliseconds timeout(0);
    if (m_local)
      timeout = boost::posix_time::milliseconds(DEFAULT_TIMEOUT_MS_LOCAL >> shift);
    else
      timeout = boost::posix_time::milliseconds(DEFAULT_TIMEOUT_MS_REMOTE >> shift);
    return timeout;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  boost::posix_time::milliseconds connection<t_protocol_handler>::get_timeout_from_bytes_read(size_t bytes)
  {
    boost::posix_time::milliseconds ms = (boost::posix_time::milliseconds)(unsigned)(bytes * TIMEOUT_EXTRA_MS_PER_BYTE);
    const auto cur = m_timer.expires_from_now().total_milliseconds();
    if (cur > 0)
      ms += (boost::posix_time::milliseconds)cur;
    if (ms > get_default_timeout())
      ms = get_default_timeout();
    return ms;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  unsigned int connection<t_protocol_handler>::host_count(const std::string &host, int delta)
  {
    static boost::mutex hosts_mutex;
    CRITICAL_REGION_LOCAL(hosts_mutex);
    static std::map<std::string, unsigned int> hosts;
    unsigned int &val = hosts[host];
    if (delta > 0)
      MTRACE("New connection from host " << host << ": " << val);
    else if (delta < 0)
      MTRACE("Closed connection from host " << host << ": " << val);
    CHECK_AND_ASSERT_THROW_MES(delta >= 0 || val >= (unsigned)-delta, "Count would go negative");
    CHECK_AND_ASSERT_THROW_MES(delta <= 0 || val <= std::numeric_limits<unsigned int>::max() - (unsigned)delta, "Count would wrap");
    val += delta;
    return val;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void connection<t_protocol_handler>::reset_timer(boost::posix_time::milliseconds ms, bool add)
  {
    const auto tms = ms.total_milliseconds();
    if (tms < 0 || (add && tms == 0))
    {
      MWARNING("Ignoring negative timeout " << ms);
      return;
    }
    MTRACE((add ? "Adding" : "Setting") << " " << ms << " expiry");
    auto self = safe_shared_from_this();
    if(!self)
    {
      MERROR("Resetting timer on a dead object");
      return;
    }
    if (m_was_shutdown)
    {
      MERROR("Setting timer on a shut down object");
      return;
    }
    if (add)
    {
      const auto cur = m_timer.expires_from_now().total_milliseconds();
      if (cur > 0)
        ms += (boost::posix_time::milliseconds)cur;
    }
    m_timer.expires_from_now(ms);
    m_timer.async_wait([=](const boost::system::error_code& ec)
    {
      if(ec == boost::asio::error::operation_aborted)
        return;
      MDEBUG(context << "connection timeout, closing");
      self->close();
    });
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::shutdown()
  {
    CRITICAL_REGION_BEGIN(m_shutdown_lock);
    if (m_was_shutdown)
      return true;
    m_was_shutdown = true;
    // Initiate graceful connection closure.
    m_timer.cancel();
    boost::system::error_code ignored_ec;
    if (m_ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled)
    {
      const shared_state &state = static_cast<const shared_state&>(get_state());
      if (!state.stop_signal_sent)
        socket_.shutdown(ignored_ec);
    }
    socket().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ignored_ec);
    if (!m_host.empty())
    {
      try { host_count(m_host, -1); } catch (...) { /* ignore */ }
      m_host = "";
    }
    CRITICAL_REGION_END();
    m_protocol_handler.release_protocol();
    return true;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::close()
  {
    TRY_ENTRY();
    auto self = safe_shared_from_this();
    if(!self)
      return false;
    //_info("[sock " << socket().native_handle() << "] Que Shutdown called.");
    m_timer.cancel();
    size_t send_que_size = 0;
    CRITICAL_REGION_BEGIN(m_send_que_lock);
    send_que_size = m_send_que.size();
    CRITICAL_REGION_END();
    m_want_close_connection = true;
    if(!send_que_size)
    {
      shutdown();
    }
    
    return true;
    CATCH_ENTRY_L0("connection<t_protocol_handler>::close", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::send_done()
  {
    if (m_ready_to_close)
      return close();
    m_ready_to_close = true;
    return true;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::cancel()
  {
    return close();
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void connection<t_protocol_handler>::handle_write(const boost::system::error_code& e, size_t cb)
  {
    TRY_ENTRY();
    LOG_TRACE_CC(context, "[sock " << socket().native_handle() << "] Async send calledback " << cb);

    if (e)
    {
      _dbg1("[sock " << socket().native_handle() << "] Some problems at write: " << e.message() << ':' << e.value());
      shutdown();
      return;
    }
    logger_handle_net_write(cb);

                // The single sleeping that is needed for correctly handling "out" speed throttling
		if (speed_limit_is_enabled()) {
			sleep_before_packet(cb, 1, 1);
		}

    bool do_shutdown = false;
    CRITICAL_REGION_BEGIN(m_send_que_lock);
    if(m_send_que.empty())
    {
      _erro("[sock " << socket().native_handle() << "] m_send_que.size() == 0 at handle_write!");
      return;
    }

    m_send_que.pop_front();
    if(m_send_que.empty())
    {
      if(m_want_close_connection)
      {
        do_shutdown = true;
      }
    }else
    {
      //have more data to send
		reset_timer(get_default_timeout(), false);
		auto size_now = m_send_que.front().size();
		MDEBUG("handle_write() NOW SENDS: packet="<<size_now<<" B" <<", from  queue size="<<m_send_que.size());
		if (speed_limit_is_enabled())
			do_send_handler_write_from_queue(e, m_send_que.front().size() , m_send_que.size()); // (((H)))
		CHECK_AND_ASSERT_MES( size_now == m_send_que.front().size(), void(), "Unexpected queue size");
		  async_write(boost::asio::buffer(m_send_que.front().data(), size_now) , 
           strand_.wrap(
            std::bind(&connection<t_protocol_handler>::handle_write, connection<t_protocol_handler>::shared_from_this(), std::placeholders::_1, std::placeholders::_2)
			  )
          );
      //_dbg3("(normal)" << size_now);
    }
    CRITICAL_REGION_END();

    if(do_shutdown)
    {
      shutdown();
    }
    CATCH_ENTRY_L0("connection<t_protocol_handler>::handle_write", void());
  }

  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void connection<t_protocol_handler>::setRpcStation()
  {
    m_connection_type = e_connection_type_RPC; 
    MDEBUG("set m_connection_type = RPC ");
  }


  template<class t_protocol_handler>
  bool connection<t_protocol_handler>::speed_limit_is_enabled() const {
		return m_connection_type != e_connection_type_RPC ;
	}

  /************************************************************************/
  /*                                                                      */
  /************************************************************************/

  template<class t_protocol_handler>
  boosted_tcp_server<t_protocol_handler>::boosted_tcp_server( t_connection_type connection_type ) :
    m_state(std::make_shared<typename connection<t_protocol_handler>::shared_state>()),
    m_io_service_local_instance(new worker()),
    io_service_(m_io_service_local_instance->io_service),
    acceptor_(io_service_),
    acceptor_ipv6(io_service_),
    default_remote(),
    m_stop_signal_sent(false), m_port(0), 
    m_threads_count(0),
    m_thread_index(0),
		m_connection_type( connection_type ),
    new_connection_(),
    new_connection_ipv6()
  {
    create_server_type_map();
    m_thread_name_prefix = "NET";
  }

  template<class t_protocol_handler>
  boosted_tcp_server<t_protocol_handler>::boosted_tcp_server(boost::asio::io_service& extarnal_io_service, t_connection_type connection_type) :
    m_state(std::make_shared<typename connection<t_protocol_handler>::shared_state>()),
    io_service_(extarnal_io_service),
    acceptor_(io_service_),
    acceptor_ipv6(io_service_),
    default_remote(),
    m_stop_signal_sent(false), m_port(0),
    m_threads_count(0),
    m_thread_index(0),
		m_connection_type(connection_type),
    new_connection_(),
    new_connection_ipv6()
  {
    create_server_type_map();
    m_thread_name_prefix = "NET";
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  boosted_tcp_server<t_protocol_handler>::~boosted_tcp_server()
  {
    this->send_stop_signal();
    timed_wait_server_stop(10000);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void boosted_tcp_server<t_protocol_handler>::create_server_type_map() 
  {
		server_type_map["NET"] = e_connection_type_NET;
		server_type_map["RPC"] = e_connection_type_RPC;
		server_type_map["P2P"] = e_connection_type_P2P;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
    bool boosted_tcp_server<t_protocol_handler>::init_server(uint32_t port,  const std::string& address,
	uint32_t port_ipv6, const std::string& address_ipv6, bool use_ipv6, bool require_ipv4,
	ssl_options_t ssl_options)
  {
    TRY_ENTRY();
    m_stop_signal_sent = false;
    m_port = port;
    m_port_ipv6 = port_ipv6;
    m_address = address;
    m_address_ipv6 = address_ipv6;
    m_use_ipv6 = use_ipv6;
    m_require_ipv4 = require_ipv4;

    if (ssl_options)
      m_state->configure_ssl(std::move(ssl_options));

    std::string ipv4_failed = "";
    std::string ipv6_failed = "";
    try
    {
      boost::asio::ip::tcp::resolver resolver(io_service_);
      boost::asio::ip::tcp::resolver::query query(address, boost::lexical_cast<std::string>(port), boost::asio::ip::tcp::resolver::query::canonical_name);
      boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query);
      acceptor_.open(endpoint.protocol());
#if !defined(_WIN32)
      acceptor_.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
#endif
      acceptor_.bind(endpoint);
      acceptor_.listen();
      boost::asio::ip::tcp::endpoint binded_endpoint = acceptor_.local_endpoint();
      m_port = binded_endpoint.port();
      MDEBUG("start accept (IPv4)");
      new_connection_.reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, m_state->ssl_options().support));
      acceptor_.async_accept(new_connection_->socket(),
	boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept_ipv4, this,
	boost::asio::placeholders::error));
    }
    catch (const std::exception &e)
    {
      ipv4_failed = e.what();
    }

    if (ipv4_failed != "")
    {
      MERROR("Failed to bind IPv4: " << ipv4_failed);
      if (require_ipv4)
      {
        throw std::runtime_error("Failed to bind IPv4 (set to required)");
      }
    }

    if (use_ipv6)
    {
      try
      {
        if (port_ipv6 == 0) port_ipv6 = port; // default arg means bind to same port as ipv4
        boost::asio::ip::tcp::resolver resolver(io_service_);
        boost::asio::ip::tcp::resolver::query query(address_ipv6, boost::lexical_cast<std::string>(port_ipv6), boost::asio::ip::tcp::resolver::query::canonical_name);
        boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query);
        acceptor_ipv6.open(endpoint.protocol());
#if !defined(_WIN32)
        acceptor_ipv6.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
#endif
        acceptor_ipv6.set_option(boost::asio::ip::v6_only(true));
        acceptor_ipv6.bind(endpoint);
        acceptor_ipv6.listen();
        boost::asio::ip::tcp::endpoint binded_endpoint = acceptor_ipv6.local_endpoint();
        m_port_ipv6 = binded_endpoint.port();
        MDEBUG("start accept (IPv6)");
        new_connection_ipv6.reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, m_state->ssl_options().support));
        acceptor_ipv6.async_accept(new_connection_ipv6->socket(),
            boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept_ipv6, this,
              boost::asio::placeholders::error));
      }
      catch (const std::exception &e)
      {
        ipv6_failed = e.what();
      }
    }

      if (use_ipv6 && ipv6_failed != "")
      {
        MERROR("Failed to bind IPv6: " << ipv6_failed);
        if (ipv4_failed != "")
        {
          throw std::runtime_error("Failed to bind IPv4 and IPv6");
        }
      }

    return true;
    }
    catch (const std::exception &e)
    {
      MFATAL("Error starting server: " << e.what());
      return false;
    }
    catch (...)
    {
      MFATAL("Error starting server");
      return false;
    }
  }
  //-----------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool boosted_tcp_server<t_protocol_handler>::init_server(const std::string port,  const std::string& address,
      const std::string port_ipv6, const std::string address_ipv6, bool use_ipv6, bool require_ipv4,
      ssl_options_t ssl_options)
  {
    uint32_t p = 0;
    uint32_t p_ipv6 = 0;

    if (port.size() && !string_tools::get_xtype_from_string(p, port)) {
      MERROR("Failed to convert port no = " << port);
      return false;
    }

    if (port_ipv6.size() && !string_tools::get_xtype_from_string(p_ipv6, port_ipv6)) {
      MERROR("Failed to convert port no = " << port_ipv6);
      return false;
    }
    return this->init_server(p, address, p_ipv6, address_ipv6, use_ipv6, require_ipv4, std::move(ssl_options));
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool boosted_tcp_server<t_protocol_handler>::worker_thread()
  {
    TRY_ENTRY();
    const uint32_t local_thr_index = m_thread_index++; // atomically increment, getting value before increment
    std::string thread_name = std::string("[") + m_thread_name_prefix;
    thread_name += boost::to_string(local_thr_index) + "]";
    MLOG_SET_THREAD_NAME(thread_name);
    //   _fact("Thread name: " << m_thread_name_prefix);
    while(!m_stop_signal_sent)
    {
      try
      {
        io_service_.run();
        return true;
      }
      catch(const std::exception& ex)
      {
        _erro("Exception at server worker thread, what=" << ex.what());
      }
      catch(...)
      {
        _erro("Exception at server worker thread, unknown execption");
      }
    }
    //_info("Worker thread finished");
    return true;
    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::worker_thread", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void boosted_tcp_server<t_protocol_handler>::set_threads_prefix(const std::string& prefix_name)
  {
    m_thread_name_prefix = prefix_name;
		auto it = server_type_map.find(m_thread_name_prefix);
		if (it==server_type_map.end()) throw std::runtime_error("Unknown prefix/server type:" + std::string(prefix_name));
    auto connection_type = it->second; // the value of type
    MINFO("Set server type to: " << connection_type << " from name: " << m_thread_name_prefix << ", prefix_name = " << prefix_name);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void boosted_tcp_server<t_protocol_handler>::set_connection_filter(i_connection_filter* pfilter)
  {
    assert(m_state != nullptr); // always set in constructor
    m_state->pfilter = pfilter;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool boosted_tcp_server<t_protocol_handler>::run_server(size_t threads_count, bool wait, const boost::thread::attributes& attrs)
  {
    TRY_ENTRY();
    m_threads_count = threads_count;
    m_main_thread_id = boost::this_thread::get_id();
    MLOG_SET_THREAD_NAME("[SRV_MAIN]");
    while(!m_stop_signal_sent)
    {

      // Create a pool of threads to run all of the io_services.
      CRITICAL_REGION_BEGIN(m_threads_lock);
      for (std::size_t i = 0; i < threads_count; ++i)
      {
        boost::shared_ptr<boost::thread> thread(new boost::thread(
          attrs, boost::bind(&boosted_tcp_server<t_protocol_handler>::worker_thread, this)));
          _note("Run server thread name: " << m_thread_name_prefix);
        m_threads.push_back(thread);
      }
      CRITICAL_REGION_END();
      // Wait for all threads in the pool to exit.
      if (wait)
      {
		_fact("JOINING all threads");
        for (std::size_t i = 0; i < m_threads.size(); ++i) {
			m_threads[i]->join();
         }
         _fact("JOINING all threads - almost");
        m_threads.clear();
        _fact("JOINING all threads - DONE");

      } 
      else {
		_dbg1("Reiniting OK.");
        return true;
      }

      if(wait && !m_stop_signal_sent)
      {
        //some problems with the listening socket ?..
        _dbg1("Net service stopped without stop request, restarting...");
        if(!this->init_server(m_port, m_address, m_port_ipv6, m_address_ipv6, m_use_ipv6, m_require_ipv4))
        {
          _dbg1("Reiniting service failed, exit.");
          return false;
        }else
        {
          _dbg1("Reiniting OK.");
        }
      }
    }
    return true;
    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::run_server", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool boosted_tcp_server<t_protocol_handler>::is_thread_worker()
  {
    TRY_ENTRY();
    CRITICAL_REGION_LOCAL(m_threads_lock);
    BOOST_FOREACH(boost::shared_ptr<boost::thread>& thp,  m_threads)
    {
      if(thp->get_id() == boost::this_thread::get_id())
        return true;
    }
    if(m_threads_count == 1 && boost::this_thread::get_id() == m_main_thread_id)
      return true;
    return false;
    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::is_thread_worker", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool boosted_tcp_server<t_protocol_handler>::timed_wait_server_stop(uint64_t wait_mseconds)
  {
    TRY_ENTRY();
    boost::chrono::milliseconds ms(wait_mseconds);
    for (std::size_t i = 0; i < m_threads.size(); ++i)
    {
      if(m_threads[i]->joinable() && !m_threads[i]->try_join_for(ms))
      {
        _dbg1("Interrupting thread " << m_threads[i]->native_handle());
        m_threads[i]->interrupt();
      }
    }
    return true;
    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::timed_wait_server_stop", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void boosted_tcp_server<t_protocol_handler>::send_stop_signal()
  {
    m_stop_signal_sent = true;
    typename connection<t_protocol_handler>::shared_state *state = static_cast<typename connection<t_protocol_handler>::shared_state*>(m_state.get());
    state->stop_signal_sent = true;
    TRY_ENTRY();
    connections_mutex.lock();
    for (auto &c: connections_)
    {
      c->cancel();
    }
    connections_.clear();
    connections_mutex.unlock();
    io_service_.stop();
    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::send_stop_signal()", void());
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void boosted_tcp_server<t_protocol_handler>::handle_accept_ipv4(const boost::system::error_code& e)
  {
    this->handle_accept(e, false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void boosted_tcp_server<t_protocol_handler>::handle_accept_ipv6(const boost::system::error_code& e)
  {
    this->handle_accept(e, true);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  void boosted_tcp_server<t_protocol_handler>::handle_accept(const boost::system::error_code& e, bool ipv6)
  {
    MDEBUG("handle_accept");

    boost::asio::ip::tcp::acceptor* current_acceptor = &acceptor_;
    connection_ptr* current_new_connection = &new_connection_;
    auto accept_function_pointer = &boosted_tcp_server<t_protocol_handler>::handle_accept_ipv4;
    if (ipv6)
    {
      current_acceptor = &acceptor_ipv6;
      current_new_connection = &new_connection_ipv6;
      accept_function_pointer = &boosted_tcp_server<t_protocol_handler>::handle_accept_ipv6;
    }

    try
    {
    if (!e)
    {
      if (m_connection_type == e_connection_type_RPC) {
        const char *ssl_message = "unknown";
        switch ((*current_new_connection)->get_ssl_support())
        {
          case epee::net_utils::ssl_support_t::e_ssl_support_disabled: ssl_message = "disabled"; break;
          case epee::net_utils::ssl_support_t::e_ssl_support_enabled: ssl_message = "enabled"; break;
          case epee::net_utils::ssl_support_t::e_ssl_support_autodetect: ssl_message = "autodetection"; break;
        }
        MDEBUG("New server for RPC connections, SSL " << ssl_message);
        (*current_new_connection)->setRpcStation(); // hopefully this is not needed actually
      }
      connection_ptr conn(std::move((*current_new_connection)));
      (*current_new_connection).reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, conn->get_ssl_support()));
      current_acceptor->async_accept((*current_new_connection)->socket(),
          boost::bind(accept_function_pointer, this,
            boost::asio::placeholders::error));

      boost::asio::socket_base::keep_alive opt(true);
      conn->socket().set_option(opt);

      bool res;
      if (default_remote.get_type_id() == net_utils::address_type::invalid)
        res = conn->start(true, 1 < m_threads_count);
      else
        res = conn->start(true, 1 < m_threads_count, default_remote);
      if (!res)
      {
        conn->cancel();
        return;
      }
      conn->save_dbg_log();
      return;
    }
    else
    {
      MERROR("Error in boosted_tcp_server<t_protocol_handler>::handle_accept: " << e);
    }
    }
    catch (const std::exception &e)
    {
      MERROR("Exception in boosted_tcp_server<t_protocol_handler>::handle_accept: " << e.what());
    }

    // error path, if e or exception
    assert(m_state != nullptr); // always set in constructor
    _erro("Some problems at accept: " << e.message() << ", connections_count = " << m_state->sock_count);
    misc_utils::sleep_no_w(100);
    (*current_new_connection).reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, (*current_new_connection)->get_ssl_support()));
    current_acceptor->async_accept((*current_new_connection)->socket(),
        boost::bind(accept_function_pointer, this,
          boost::asio::placeholders::error));
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool boosted_tcp_server<t_protocol_handler>::add_connection(t_connection_context& out, boost::asio::ip::tcp::socket&& sock, network_address real_remote, epee::net_utils::ssl_support_t ssl_support)
  {
    if(std::addressof(get_io_service()) == std::addressof(GET_IO_SERVICE(sock)))
    {
      connection_ptr conn(new connection<t_protocol_handler>(std::move(sock), m_state, m_connection_type, ssl_support));
      if(conn->start(false, 1 < m_threads_count, std::move(real_remote)))
      {
        conn->get_context(out);
        conn->save_dbg_log();
        return true;
      }
    }
    else
    {
	MWARNING(out << " was not added, socket/io_service mismatch");
    }
    return false;
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  typename boosted_tcp_server<t_protocol_handler>::try_connect_result_t boosted_tcp_server<t_protocol_handler>::try_connect(connection_ptr new_connection_l, const std::string& adr, const std::string& port, boost::asio::ip::tcp::socket &sock_, const boost::asio::ip::tcp::endpoint &remote_endpoint, const std::string &bind_ip, uint32_t conn_timeout, epee::net_utils::ssl_support_t ssl_support)
  {
    TRY_ENTRY();

    sock_.open(remote_endpoint.protocol());
    if(bind_ip != "0.0.0.0" && bind_ip != "0" && bind_ip != "" )
    {
      boost::asio::ip::tcp::endpoint local_endpoint(boost::asio::ip::address::from_string(bind_ip.c_str()), 0);
      boost::system::error_code ec;
      sock_.bind(local_endpoint, ec);
      if (ec)
      {
        MERROR("Error binding to " << bind_ip << ": " << ec.message());
        if (sock_.is_open())
          sock_.close();
        return CONNECT_FAILURE;
      }
    }

    /*
    NOTICE: be careful to make sync connection from event handler: in case if all threads suddenly do sync connect, there will be no thread to dispatch events from io service.
    */

    boost::system::error_code ec = boost::asio::error::would_block;

    //have another free thread(s), work in wait mode, without event handling
    struct local_async_context
    {
      boost::system::error_code ec;
      boost::mutex connect_mut;
      boost::condition_variable cond;
    };

    boost::shared_ptr<local_async_context> local_shared_context(new local_async_context());
    local_shared_context->ec = boost::asio::error::would_block;
    boost::unique_lock<boost::mutex> lock(local_shared_context->connect_mut);
    auto connect_callback = [](boost::system::error_code ec_, boost::shared_ptr<local_async_context> shared_context)
    {
      shared_context->connect_mut.lock(); shared_context->ec = ec_; shared_context->cond.notify_one(); shared_context->connect_mut.unlock();
    };

    sock_.async_connect(remote_endpoint, std::bind<void>(connect_callback, std::placeholders::_1, local_shared_context));
    while(local_shared_context->ec == boost::asio::error::would_block)
    {
      bool r = local_shared_context->cond.timed_wait(lock, boost::get_system_time() + boost::posix_time::milliseconds(conn_timeout));
      if (m_stop_signal_sent)
      {
        if (sock_.is_open())
          sock_.close();
        return CONNECT_FAILURE;
      }
      if(local_shared_context->ec == boost::asio::error::would_block && !r)
      {
        //timeout
        sock_.close();
        _dbg3("Failed to connect to " << adr << ":" << port << ", because of timeout (" << conn_timeout << ")");
        return CONNECT_FAILURE;
      }
    }
    ec = local_shared_context->ec;

    if (ec || !sock_.is_open())
    {
      _dbg3("Some problems at connect, message: " << ec.message());
      if (sock_.is_open())
        sock_.close();
      return CONNECT_FAILURE;
    }

    _dbg3("Connected success to " << adr << ':' << port);

    const ssl_support_t ssl_support = new_connection_l->get_ssl_support();
    if (ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_enabled || ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
    {
      // Handshake
      MDEBUG("Handshaking SSL...");
      if (!new_connection_l->handshake(boost::asio::ssl::stream_base::client))
      {
        if (ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect)
        {
          boost::system::error_code ignored_ec;
          sock_.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ignored_ec);
          sock_.close();
          return CONNECT_NO_SSL;
        }
        MERROR("SSL handshake failed");
        if (sock_.is_open())
          sock_.close();
        return CONNECT_FAILURE;
      }
    }

    return CONNECT_SUCCESS;

    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::try_connect", CONNECT_FAILURE);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler>
  bool boosted_tcp_server<t_protocol_handler>::connect(const std::string& adr, const std::string& port, uint32_t conn_timeout, t_connection_context& conn_context, const std::string& bind_ip, epee::net_utils::ssl_support_t ssl_support)
  {
    TRY_ENTRY();

    connection_ptr new_connection_l(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, ssl_support) );
    connections_mutex.lock();
    connections_.insert(new_connection_l);
    MDEBUG("connections_ size now " << connections_.size());
    connections_mutex.unlock();
    epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){ CRITICAL_REGION_LOCAL(connections_mutex); connections_.erase(new_connection_l); });
    boost::asio::ip::tcp::socket&  sock_ = new_connection_l->socket();

    bool try_ipv6 = false;

    boost::asio::ip::tcp::resolver resolver(io_service_);
    boost::asio::ip::tcp::resolver::query query(boost::asio::ip::tcp::v4(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
    boost::system::error_code resolve_error;
    boost::asio::ip::tcp::resolver::iterator iterator;
    try
    {
      //resolving ipv4 address as ipv6 throws, catch here and move on
      iterator = resolver.resolve(query, resolve_error);
    }
    catch (const boost::system::system_error& e)
    {
      if (!m_use_ipv6 || (resolve_error != boost::asio::error::host_not_found &&
            resolve_error != boost::asio::error::host_not_found_try_again))
      {
        throw;
      }
      try_ipv6 = true;
    }
    catch (...)
    {
      throw;
    }

    std::string bind_ip_to_use;

    boost::asio::ip::tcp::resolver::iterator end;
    if(iterator == end)
    {
      if (!m_use_ipv6)
      {
        _erro("Failed to resolve " << adr);
        return false;
      }
      else
      {
        try_ipv6 = true;
        MINFO("Resolving address as IPv4 failed, trying IPv6");
      }
    }
    else
    {
      bind_ip_to_use = bind_ip;
    }

    if (try_ipv6)
    {
      boost::asio::ip::tcp::resolver::query query6(boost::asio::ip::tcp::v6(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);

      iterator = resolver.resolve(query6, resolve_error);

      if(iterator == end)
      {
        _erro("Failed to resolve " << adr);
        return false;
      }
      else
      {
        if (bind_ip == "0.0.0.0")
        {
          bind_ip_to_use = "::";
        }
        else
        {
          bind_ip_to_use = "";
        }

      }

    }

    MDEBUG("Trying to connect to " << adr << ":" << port << ", bind_ip = " << bind_ip_to_use);

    //boost::asio::ip::tcp::endpoint remote_endpoint(boost::asio::ip::address::from_string(addr.c_str()), port);
    boost::asio::ip::tcp::endpoint remote_endpoint(*iterator);

    auto try_connect_result = try_connect(new_connection_l, adr, port, sock_, remote_endpoint, bind_ip_to_use, conn_timeout, ssl_support);
    if (try_connect_result == CONNECT_FAILURE)
      return false;
    if (ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect && try_connect_result == CONNECT_NO_SSL)
    {
      // we connected, but could not connect with SSL, try without
      MERROR("SSL handshake failed on an autodetect connection, reconnecting without SSL");
      new_connection_l->disable_ssl();
      try_connect_result = try_connect(new_connection_l, adr, port, sock_, remote_endpoint, bind_ip_to_use, conn_timeout, epee::net_utils::ssl_support_t::e_ssl_support_disabled);
      if (try_connect_result != CONNECT_SUCCESS)
        return false;
    }

    // start adds the connection to the config object's list, so we don't need to have it locally anymore
    connections_mutex.lock();
    connections_.erase(new_connection_l);
    connections_mutex.unlock();
    bool r = new_connection_l->start(false, 1 < m_threads_count);
    if (r)
    {
      new_connection_l->get_context(conn_context);
      //new_connection_l.reset(new connection<t_protocol_handler>(io_service_, m_config, m_sock_count, m_pfilter));
    }
    else
    {
      assert(m_state != nullptr); // always set in constructor
      _erro("[sock " << new_connection_l->socket().native_handle() << "] Failed to start connection, connections_count = " << m_state->sock_count);
    }
    
	new_connection_l->save_dbg_log();

    return r;

    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::connect", false);
  }
  //---------------------------------------------------------------------------------
  template<class t_protocol_handler> template<class t_callback>
  bool boosted_tcp_server<t_protocol_handler>::connect_async(const std::string& adr, const std::string& port, uint32_t conn_timeout, const t_callback &cb, const std::string& bind_ip, epee::net_utils::ssl_support_t ssl_support)
  {
    TRY_ENTRY();    
    connection_ptr new_connection_l(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, ssl_support) );
    connections_mutex.lock();
    connections_.insert(new_connection_l);
    MDEBUG("connections_ size now " << connections_.size());
    connections_mutex.unlock();
    epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){ CRITICAL_REGION_LOCAL(connections_mutex); connections_.erase(new_connection_l); });
    boost::asio::ip::tcp::socket&  sock_ = new_connection_l->socket();
    
    bool try_ipv6 = false;

    boost::asio::ip::tcp::resolver resolver(io_service_);
    boost::asio::ip::tcp::resolver::query query(boost::asio::ip::tcp::v4(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
    boost::system::error_code resolve_error;
    boost::asio::ip::tcp::resolver::iterator iterator;
    try
    {
      //resolving ipv4 address as ipv6 throws, catch here and move on
      iterator = resolver.resolve(query, resolve_error);
    }
    catch (const boost::system::system_error& e)
    {
      if (!m_use_ipv6 || (resolve_error != boost::asio::error::host_not_found &&
            resolve_error != boost::asio::error::host_not_found_try_again))
      {
        throw;
      }
      try_ipv6 = true;
    }
    catch (...)
    {
      throw;
    }

    boost::asio::ip::tcp::resolver::iterator end;
    if(iterator == end)
    {
      if (!try_ipv6)
      {
        _erro("Failed to resolve " << adr);
        return false;
      }
      else
      {
        MINFO("Resolving address as IPv4 failed, trying IPv6");
      }
    }

    if (try_ipv6)
    {
      boost::asio::ip::tcp::resolver::query query6(boost::asio::ip::tcp::v6(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);

      iterator = resolver.resolve(query6, resolve_error);

      if(iterator == end)
      {
        _erro("Failed to resolve " << adr);
        return false;
      }
    }


    boost::asio::ip::tcp::endpoint remote_endpoint(*iterator);
     
    sock_.open(remote_endpoint.protocol());
    if(bind_ip != "0.0.0.0" && bind_ip != "0" && bind_ip != "" )
    {
      boost::asio::ip::tcp::endpoint local_endpoint(boost::asio::ip::address::from_string(bind_ip.c_str()), 0);
      boost::system::error_code ec;
      sock_.bind(local_endpoint, ec);
      if (ec)
      {
        MERROR("Error binding to " << bind_ip << ": " << ec.message());
        if (sock_.is_open())
          sock_.close();
        return false;
      }
    }
    
    boost::shared_ptr<boost::asio::deadline_timer> sh_deadline(new boost::asio::deadline_timer(io_service_));
    //start deadline
    sh_deadline->expires_from_now(boost::posix_time::milliseconds(conn_timeout));
    sh_deadline->async_wait([=](const boost::system::error_code& error)
      {
          if(error != boost::asio::error::operation_aborted) 
          {
            _dbg3("Failed to connect to " << adr << ':' << port << ", because of timeout (" << conn_timeout << ")");
            new_connection_l->socket().close();
          }
      });
    //start async connect
    sock_.async_connect(remote_endpoint, [=](const boost::system::error_code& ec_)
      {
        t_connection_context conn_context = AUTO_VAL_INIT(conn_context);
        boost::system::error_code ignored_ec;
        boost::asio::ip::tcp::socket::endpoint_type lep = new_connection_l->socket().local_endpoint(ignored_ec);
        if(!ec_)
        {//success
          if(!sh_deadline->cancel())
          {
            cb(conn_context, boost::asio::error::operation_aborted);//this mean that deadline timer already queued callback with cancel operation, rare situation
          }else
          {
            _dbg3("[sock " << new_connection_l->socket().native_handle() << "] Connected success to " << adr << ':' << port <<
              " from " << lep.address().to_string() << ':' << lep.port());

            // start adds the connection to the config object's list, so we don't need to have it locally anymore
            connections_mutex.lock();
            connections_.erase(new_connection_l);
            connections_mutex.unlock();
            bool r = new_connection_l->start(false, 1 < m_threads_count);
            if (r)
            {
              new_connection_l->get_context(conn_context);
              cb(conn_context, ec_);
            }
            else
            {
              _dbg3("[sock " << new_connection_l->socket().native_handle() << "] Failed to start connection to " << adr << ':' << port);
              cb(conn_context, boost::asio::error::fault);
            }
          }
        }else
        {
          _dbg3("[sock " << new_connection_l->socket().native_handle() << "] Failed to connect to " << adr << ':' << port <<
            " from " << lep.address().to_string() << ':' << lep.port() << ": " << ec_.message() << ':' << ec_.value());
          cb(conn_context, ec_);
        }
      });
    return true;
    CATCH_ENTRY_L0("boosted_tcp_server<t_protocol_handler>::connect_async", false);
  }
  
} // namespace
} // namespace