net_node.inl

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// Copyright (c) 2014-2022, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. 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.
//
// 3. Neither the name of the copyright holder 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 HOLDER OR CONTRIBUTORS 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.
//
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
 
// IP blocking adapted from Boolberry
 
#include <algorithm>
#include <boost/bind/bind.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/filesystem/operations.hpp>
#include <boost/optional/optional.hpp>
#include <boost/thread/thread.hpp>
#include <boost/uuid/uuid_io.hpp>
#include <boost/algorithm/string.hpp>
#include <atomic>
#include <functional>
#include <limits>
#include <memory>
#include <tuple>
#include <vector>
 
#include "version.h"
#include "string_tools.h"
#include "common/util.h"
#include "common/dns_utils.h"
#include "common/pruning.h"
#include "net/error.h"
#include "net/net_helper.h"
#include "math_helper.h"
#include "misc_log_ex.h"
#include "p2p_protocol_defs.h"
#include "crypto/crypto.h"
#include "storages/levin_abstract_invoke2.h"
#include "cryptonote_core/cryptonote_core.h"
#include "net/parse.h"
 
 
#undef MONERO_DEFAULT_LOG_CATEGORY
#define MONERO_DEFAULT_LOG_CATEGORY "net.p2p"
 
#define NET_MAKE_IP(b1,b2,b3,b4)  ((LPARAM)(((DWORD)(b1)<<24)+((DWORD)(b2)<<16)+((DWORD)(b3)<<8)+((DWORD)(b4))))
 
#define MIN_WANTED_SEED_NODES 12
 
static inline boost::asio::ip::address_v4 make_address_v4_from_v6(const boost::asio::ip::address_v6& a)
{
  const auto &bytes = a.to_bytes();
  uint32_t v4 = 0;
  v4 = (v4 << 8) | bytes[12];
  v4 = (v4 << 8) | bytes[13];
  v4 = (v4 << 8) | bytes[14];
  v4 = (v4 << 8) | bytes[15];
  return boost::asio::ip::address_v4(v4);
}
 
namespace nodetool
{
  template<class t_payload_net_handler>
  node_server<t_payload_net_handler>::~node_server()
  {
    // tcp server uses io_context in destructor, and every zone uses
    // io_service from public zone.
    for (auto current = m_network_zones.begin(); current != m_network_zones.end(); /* below */)
    {
      if (current->first != epee::net_utils::zone::public_)
        current = m_network_zones.erase(current);
      else
        ++current;
    }
  }
  //-----------------------------------------------------------------------------------
  inline bool append_net_address(std::vector<epee::net_utils::network_address> & seed_nodes, std::string const & addr, uint16_t default_port);
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::init_options(boost::program_options::options_description& desc)
  {
    command_line::add_arg(desc, arg_p2p_bind_ip);
    command_line::add_arg(desc, arg_p2p_bind_ipv6_address);
    command_line::add_arg(desc, arg_p2p_bind_port, false);
    command_line::add_arg(desc, arg_p2p_bind_port_ipv6, false);
    command_line::add_arg(desc, arg_p2p_use_ipv6);
    command_line::add_arg(desc, arg_p2p_ignore_ipv4);
    command_line::add_arg(desc, arg_p2p_external_port);
    command_line::add_arg(desc, arg_p2p_allow_local_ip);
    command_line::add_arg(desc, arg_p2p_add_peer);
    command_line::add_arg(desc, arg_p2p_add_priority_node);
    command_line::add_arg(desc, arg_p2p_add_exclusive_node);
    command_line::add_arg(desc, arg_p2p_seed_node);
    command_line::add_arg(desc, arg_tx_proxy);
    command_line::add_arg(desc, arg_anonymous_inbound);
    command_line::add_arg(desc, arg_ban_list);
    command_line::add_arg(desc, arg_p2p_hide_my_port);
    command_line::add_arg(desc, arg_no_sync);
    command_line::add_arg(desc, arg_enable_dns_blocklist);
    command_line::add_arg(desc, arg_no_igd);
    command_line::add_arg(desc, arg_igd);
    command_line::add_arg(desc, arg_out_peers);
    command_line::add_arg(desc, arg_in_peers);
    command_line::add_arg(desc, arg_tos_flag);
    command_line::add_arg(desc, arg_limit_rate_up);
    command_line::add_arg(desc, arg_limit_rate_down);
    command_line::add_arg(desc, arg_limit_rate);
    command_line::add_arg(desc, arg_pad_transactions);
    command_line::add_arg(desc, arg_max_connections_per_ip);
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::init_config()
  {
    TRY_ENTRY();
    auto storage = peerlist_storage::open(m_config_folder + "/" + P2P_NET_DATA_FILENAME);
    if (storage)
      m_peerlist_storage = std::move(*storage);
 
    network_zone& public_zone = m_network_zones[epee::net_utils::zone::public_];
    public_zone.m_config.m_support_flags = P2P_SUPPORT_FLAGS;
    public_zone.m_config.m_peer_id = crypto::rand<uint64_t>();
    m_first_connection_maker_call = true;
 
    CATCH_ENTRY_L0("node_server::init_config", false);
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::for_each_connection(std::function<bool(typename t_payload_net_handler::connection_context&, peerid_type, uint32_t)> f)
  {
    for(auto& zone : m_network_zones)
    {
      zone.second.m_net_server.get_config_object().foreach_connection([&](p2p_connection_context& cntx){
        return f(cntx, cntx.peer_id, cntx.support_flags);
      });
    }
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::for_connection(const boost::uuids::uuid &connection_id, std::function<bool(typename t_payload_net_handler::connection_context&, peerid_type, uint32_t)> f)
  {
    for(auto& zone : m_network_zones)
    {
      const bool result = zone.second.m_net_server.get_config_object().for_connection(connection_id, [&](p2p_connection_context& cntx){
        return f(cntx, cntx.peer_id, cntx.support_flags);
      });
      if (result)
        return true;
    }
    return false;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::is_remote_host_allowed(const epee::net_utils::network_address &address, time_t *t)
  {
    CRITICAL_REGION_LOCAL(m_blocked_hosts_lock);
 
    const time_t now = time(nullptr);
 
    // look in the hosts list
    auto it = m_blocked_hosts.find(address.host_str());
    if (it != m_blocked_hosts.end())
    {
      if (now >= it->second)
      {
        m_blocked_hosts.erase(it);
        MCLOG_CYAN(el::Level::Info, "global", "Host " << address.host_str() << " unblocked.");
        it = m_blocked_hosts.end();
      }
      else
      {
        if (t)
          *t = it->second - now;
        return false;
      }
    }
 
    // manually loop in subnets
    if (address.get_type_id() == epee::net_utils::address_type::ipv4)
    {
      auto ipv4_address = address.template as<epee::net_utils::ipv4_network_address>();
      std::map<epee::net_utils::ipv4_network_subnet, time_t>::iterator it;
      for (it = m_blocked_subnets.begin(); it != m_blocked_subnets.end(); )
      {
        if (now >= it->second)
        {
          it = m_blocked_subnets.erase(it);
          MCLOG_CYAN(el::Level::Info, "global", "Subnet " << it->first.host_str() << " unblocked.");
          continue;
        }
        if (it->first.matches(ipv4_address))
        {
          if (t)
            *t = it->second - now;
          return false;
        }
        ++it;
      }
    }
 
    // not found in hosts or subnets, allowed
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::is_host_limit(const epee::net_utils::network_address &address)
  {
    const network_zone& zone = m_network_zones.at(address.get_zone());
    if (zone.m_current_number_of_in_peers >= zone.m_config.m_net_config.max_in_connection_count) // in peers limit
    {
      MWARNING("Exceeded max incoming connections, so dropping this one.");
      return true;
    }
 
    if(has_too_many_connections(address))
    {
      MWARNING("CONNECTION FROM " << address.host_str() << " REFUSED, too many connections from the same address");
      return true;
    }
 
    return false;
  }
 
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::block_host(epee::net_utils::network_address addr, time_t seconds, bool add_only)
  {
    if(!addr.is_blockable())
      return false;
 
    const time_t now = time(nullptr);
    bool added = false;
 
    CRITICAL_REGION_LOCAL(m_blocked_hosts_lock);
    time_t limit;
    if (now > std::numeric_limits<time_t>::max() - seconds)
      limit = std::numeric_limits<time_t>::max();
    else
      limit = now + seconds;
    const std::string host_str = addr.host_str();
    auto it = m_blocked_hosts.find(host_str);
    if (it == m_blocked_hosts.end())
    {
      m_blocked_hosts[host_str] = limit;
 
      // if the host was already blocked due to being in a blocked subnet, let it be silent
      bool matches_blocked_subnet = false;
      if (addr.get_type_id() == epee::net_utils::address_type::ipv4)
      {
        auto ipv4_address = addr.template as<epee::net_utils::ipv4_network_address>();
        for (auto jt = m_blocked_subnets.begin(); jt != m_blocked_subnets.end(); ++jt)
        {
          if (jt->first.matches(ipv4_address))
          {
            matches_blocked_subnet = true;
            break;
          }
        }
      }
      if (!matches_blocked_subnet)
        added = true;
    }
    else if (it->second < limit || !add_only)
      it->second = limit;
 
    // drop any connection to that address. This should only have to look into
    // the zone related to the connection, but really make sure everything is
    // swept ...
    std::vector<boost::uuids::uuid> conns;
    for(auto& zone : m_network_zones)
    {
      zone.second.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
      {
        if (cntxt.m_remote_address.is_same_host(addr))
        {
          conns.push_back(cntxt.m_connection_id);
        }
        return true;
      });
 
      peerlist_entry pe{};
      pe.adr = addr;
      if (addr.port() == 0)
      {
        zone.second.m_peerlist.evict_host_from_peerlist(true, pe);
        zone.second.m_peerlist.evict_host_from_peerlist(false, pe);
      }
      else
      {
        zone.second.m_peerlist.remove_from_peer_white(pe);
        zone.second.m_peerlist.remove_from_peer_gray(pe);
        zone.second.m_peerlist.remove_from_peer_anchor(addr);
     }
 
      for (const auto &c: conns)
        zone.second.m_net_server.get_config_object().close(c, false);
 
      conns.clear();
    }
 
    if (added)
      MCLOG_CYAN(el::Level::Info, "global", "Host " << host_str << " blocked.");
    else
      MINFO("Host " << host_str << " block time updated.");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::unblock_host(const epee::net_utils::network_address &address)
  {
    CRITICAL_REGION_LOCAL(m_blocked_hosts_lock);
    auto i = m_blocked_hosts.find(address.host_str());
    if (i == m_blocked_hosts.end())
      return false;
    m_blocked_hosts.erase(i);
    MCLOG_CYAN(el::Level::Info, "global", "Host " << address.host_str() << " unblocked.");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::block_subnet(const epee::net_utils::ipv4_network_subnet &subnet, time_t seconds)
  {
    const time_t now = time(nullptr);
 
    CRITICAL_REGION_LOCAL(m_blocked_hosts_lock);
    time_t limit;
    if (now > std::numeric_limits<time_t>::max() - seconds)
      limit = std::numeric_limits<time_t>::max();
    else
      limit = now + seconds;
    const bool added = m_blocked_subnets.find(subnet) == m_blocked_subnets.end();
    m_blocked_subnets[subnet] = limit;
 
    // drop any connection to that subnet. This should only have to look into
    // the zone related to the connection, but really make sure everything is
    // swept ...
    std::vector<boost::uuids::uuid> conns;
    for(auto& zone : m_network_zones)
    {
      zone.second.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
      {
        if (cntxt.m_remote_address.get_type_id() != epee::net_utils::ipv4_network_address::get_type_id())
          return true;
        auto ipv4_address = cntxt.m_remote_address.template as<epee::net_utils::ipv4_network_address>();
        if (subnet.matches(ipv4_address))
        {
          conns.push_back(cntxt.m_connection_id);
        }
        return true;
      });
      for (const auto &c: conns)
        zone.second.m_net_server.get_config_object().close(c, false);
 
      for (int i = 0; i < 2; ++i)
        zone.second.m_peerlist.filter(i == 0, [&subnet](const peerlist_entry &pe){
          if (pe.adr.get_type_id() != epee::net_utils::ipv4_network_address::get_type_id())
            return false;
          return subnet.matches(pe.adr.as<const epee::net_utils::ipv4_network_address>());
        });
 
      conns.clear();
    }
 
    if (added)
      MCLOG_CYAN(el::Level::Info, "global", "Subnet " << subnet.host_str() << " blocked.");
    else
      MINFO("Subnet " << subnet.host_str() << " blocked.");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::unblock_subnet(const epee::net_utils::ipv4_network_subnet &subnet)
  {
    CRITICAL_REGION_LOCAL(m_blocked_hosts_lock);
    auto i = m_blocked_subnets.find(subnet);
    if (i == m_blocked_subnets.end())
      return false;
    m_blocked_subnets.erase(i);
    MCLOG_CYAN(el::Level::Info, "global", "Subnet " << subnet.host_str() << " unblocked.");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::add_host_fail(const epee::net_utils::network_address &address, unsigned int score)
  {
    if(!address.is_blockable())
      return false;
 
    CRITICAL_REGION_LOCAL(m_host_fails_score_lock);
    uint64_t fails = m_host_fails_score[address.host_str()] += score;
    MDEBUG("Host " << address.host_str() << " fail score=" << fails);
    if(fails > P2P_IP_FAILS_BEFORE_BLOCK)
    {
      auto it = m_host_fails_score.find(address.host_str());
      CHECK_AND_ASSERT_MES(it != m_host_fails_score.end(), false, "internal error");
      it->second = P2P_IP_FAILS_BEFORE_BLOCK/2;
      block_host(address);
    }
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::handle_command_line(
      const boost::program_options::variables_map& vm
    )
  {
    bool testnet = command_line::get_arg(vm, cryptonote::arg_testnet_on);
    bool stagenet = command_line::get_arg(vm, cryptonote::arg_stagenet_on);
    bool regtest = command_line::get_arg(vm, cryptonote::arg_regtest_on);
    const bool pad_txs = command_line::get_arg(vm, arg_pad_transactions);
    m_nettype = testnet ? cryptonote::TESTNET : stagenet ? cryptonote::STAGENET : regtest ? cryptonote::FAKECHAIN : cryptonote::MAINNET;
 
    network_zone& public_zone = m_network_zones[epee::net_utils::zone::public_];
    public_zone.m_connect = &public_connect;
    public_zone.m_bind_ip = command_line::get_arg(vm, arg_p2p_bind_ip);
    public_zone.m_bind_ipv6_address = command_line::get_arg(vm, arg_p2p_bind_ipv6_address);
    public_zone.m_port = command_line::get_arg(vm, arg_p2p_bind_port);
    public_zone.m_port_ipv6 = command_line::get_arg(vm, arg_p2p_bind_port_ipv6);
    public_zone.m_can_pingback = true;
    m_external_port = command_line::get_arg(vm, arg_p2p_external_port);
    m_allow_local_ip = command_line::get_arg(vm, arg_p2p_allow_local_ip);
    if (!command_line::is_arg_defaulted(vm, arg_igd)) {
      MWARNING("UPnP port mapping support was removed. The --igd option is currently non-functional.");
    }
    m_offline = command_line::get_arg(vm, cryptonote::arg_offline);
    m_use_ipv6 = command_line::get_arg(vm, arg_p2p_use_ipv6);
    m_require_ipv4 = !command_line::get_arg(vm, arg_p2p_ignore_ipv4);
    public_zone.m_notifier = cryptonote::levin::notify{
      public_zone.m_net_server.get_io_context(), public_zone.m_net_server.get_config_shared(), nullptr, epee::net_utils::zone::public_, pad_txs, m_payload_handler.get_core()
    };
 
    if (command_line::has_arg(vm, arg_p2p_add_peer))
    {
      std::vector<std::string> perrs = command_line::get_arg(vm, arg_p2p_add_peer);
      for(const std::string& pr_str: perrs)
      {
        nodetool::peerlist_entry pe = AUTO_VAL_INIT(pe);
        pe.id = crypto::rand<uint64_t>();
        const uint16_t default_port = cryptonote::get_config(m_nettype).P2P_DEFAULT_PORT;
        expect<epee::net_utils::network_address> adr = net::get_network_address(pr_str, default_port);
        if (adr)
        {
          add_zone(adr->get_zone());
          pe.adr = std::move(*adr);
          m_command_line_peers.push_back(std::move(pe));
          continue;
        }
        CHECK_AND_ASSERT_MES(
          adr == net::error::unsupported_address, false, "Bad address (\"" << pr_str << "\"): " << adr.error().message()
        );
 
        std::vector<epee::net_utils::network_address> resolved_addrs;
        bool r = append_net_address(resolved_addrs, pr_str, default_port);
        CHECK_AND_ASSERT_MES(r, false, "Failed to parse or resolve address from string: " << pr_str);
        for (const epee::net_utils::network_address& addr : resolved_addrs)
        {
          pe.id = crypto::rand<uint64_t>();
          pe.adr = addr;
          m_command_line_peers.push_back(pe);
        }
      }
    }
 
    if (command_line::has_arg(vm,arg_p2p_add_exclusive_node))
    {
      if (!parse_peers_and_add_to_container(vm, arg_p2p_add_exclusive_node, m_exclusive_peers))
        return false;
    }
 
    if (command_line::has_arg(vm, arg_p2p_add_priority_node))
    {
      if (!parse_peers_and_add_to_container(vm, arg_p2p_add_priority_node, m_priority_peers))
        return false;
    }
 
    if (command_line::has_arg(vm, arg_p2p_seed_node))
    {
      boost::unique_lock<boost::shared_mutex> lock(public_zone.m_seed_nodes_lock);
 
      if (!parse_peers_and_add_to_container(vm, arg_p2p_seed_node, public_zone.m_seed_nodes))
        return false;
    }
 
    if (!command_line::is_arg_defaulted(vm, arg_ban_list))
    {
      const std::string ban_list = command_line::get_arg(vm, arg_ban_list);
 
      const boost::filesystem::path ban_list_path(ban_list);
      boost::system::error_code ec;
      if (!boost::filesystem::exists(ban_list_path, ec))
      {
        throw std::runtime_error("Can't find ban list file " + ban_list + " - " + ec.message());
      }
 
      std::string banned_ips;
      if (!epee::file_io_utils::load_file_to_string(ban_list_path.string(), banned_ips))
      {
        throw std::runtime_error("Failed to read ban list file " + ban_list);
      }
 
      std::istringstream iss(banned_ips);
      for (std::string line; std::getline(iss, line); )
      {
        // ignore comments after '#' character
        const size_t pound_idx = line.find('#');
        if (pound_idx != std::string::npos)
          line.resize(pound_idx);
 
        // trim whitespace and ignore empty lines
        boost::trim(line);
        if (line.empty())
          continue;
 
        auto subnet = net::get_ipv4_subnet_address(line);
        if (subnet)
        {
          block_subnet(*subnet, std::numeric_limits<time_t>::max());
          continue;
        }
        const expect<epee::net_utils::network_address> parsed_addr = net::get_network_address(line, 0);
        if (parsed_addr)
        {
          block_host(*parsed_addr, std::numeric_limits<time_t>::max());
          continue;
        }
        MERROR("Invalid IP address or IPv4 subnet: " << line);
      }
    }
 
    if(command_line::has_arg(vm, arg_p2p_hide_my_port))
      m_hide_my_port = true;
 
    if (command_line::has_arg(vm, arg_no_sync))
      m_payload_handler.set_no_sync(true);
 
    m_enable_dns_blocklist = command_line::get_arg(vm, arg_enable_dns_blocklist);
 
    if ( !set_max_out_peers(public_zone, command_line::get_arg(vm, arg_out_peers) ) )
      return false;
    else
      m_payload_handler.set_max_out_peers(epee::net_utils::zone::public_, public_zone.m_config.m_net_config.max_out_connection_count);
 
 
    if ( !set_max_in_peers(public_zone, command_line::get_arg(vm, arg_in_peers) ) )
      return false;
 
    if ( !set_tos_flag(vm, command_line::get_arg(vm, arg_tos_flag) ) )
      return false;
 
    if ( !set_rate_up_limit(vm, command_line::get_arg(vm, arg_limit_rate_up) ) )
      return false;
 
    if ( !set_rate_down_limit(vm, command_line::get_arg(vm, arg_limit_rate_down) ) )
      return false;
 
    if ( !set_rate_limit(vm, command_line::get_arg(vm, arg_limit_rate) ) )
      return false;
 
 
    epee::byte_slice noise = nullptr;
    auto proxies = get_proxies(vm);
    if (!proxies)
      return false;
 
    for (auto& proxy : *proxies)
    {
      network_zone& zone = add_zone(proxy.zone);
      if (zone.m_connect != nullptr)
      {
        MERROR("Listed --" << arg_tx_proxy.name << " twice with " << epee::net_utils::zone_to_string(proxy.zone));
        return false;
      }
      zone.m_connect = &socks_connect;
      zone.m_proxy_address = std::move(proxy.address);
 
      if (!set_max_out_peers(zone, proxy.max_connections))
        return false;
      else
        m_payload_handler.set_max_out_peers(proxy.zone, proxy.max_connections);
 
      epee::byte_slice this_noise = nullptr;
      if (proxy.noise)
      {
        static_assert(sizeof(epee::levin::bucket_head2) < CRYPTONOTE_NOISE_BYTES, "noise bytes too small");
        if (noise.empty())
          noise = epee::levin::make_noise_notify(CRYPTONOTE_NOISE_BYTES);
 
        this_noise = noise.clone();
      }
 
      zone.m_notifier = cryptonote::levin::notify{
        zone.m_net_server.get_io_context(), zone.m_net_server.get_config_shared(), std::move(this_noise), proxy.zone, pad_txs, m_payload_handler.get_core()
      };
    }
 
    for (const auto& zone : m_network_zones)
    {
      if (zone.second.m_connect == nullptr)
      {
        MERROR("Set outgoing peer for " << epee::net_utils::zone_to_string(zone.first) << " but did not set --" << arg_tx_proxy.name);
        return false;
      }
    }
 
    auto inbounds = get_anonymous_inbounds(vm);
    if (!inbounds)
      return false;
 
    const std::size_t tx_relay_zones = m_network_zones.size();
    for (auto& inbound : *inbounds)
    {
      network_zone& zone = add_zone(inbound.our_address.get_zone());
 
      if (!zone.m_bind_ip.empty())
      {
        MERROR("Listed --" << arg_anonymous_inbound.name << " twice with " << epee::net_utils::zone_to_string(inbound.our_address.get_zone()) << " network");
        return false;
      }
 
      if (zone.m_connect == nullptr && tx_relay_zones <= 1)
      {
        MERROR("Listed --" << arg_anonymous_inbound.name << " without listing any --" << arg_tx_proxy.name << ". The latter is necessary for sending local txes over anonymity networks");
        return false;
      }
 
      zone.m_bind_ip = std::move(inbound.local_ip);
      zone.m_port = std::move(inbound.local_port);
      zone.m_net_server.set_default_remote(std::move(inbound.default_remote));
      zone.m_our_address = std::move(inbound.our_address);
 
      if (!set_max_in_peers(zone, inbound.max_connections))
        return false;
    }
 
    max_connections = command_line::get_arg(vm, arg_max_connections_per_ip);
 
    return true;
  }
  //-----------------------------------------------------------------------------------
  inline bool append_net_address(
      std::vector<epee::net_utils::network_address> & seed_nodes
    , std::string const & addr
    , uint16_t default_port
    )
  {
    using namespace boost::asio;
 
    // Split addr string into host string and port string
    std::string host;
    std::string port = std::to_string(default_port);
    net::get_network_address_host_and_port(addr, host, port);
    MINFO("Resolving node address: host=" << host << ", port=" << port);
 
    boost::system::error_code ec;
    io_context io_srv;
    ip::tcp::resolver resolver(io_srv);
    const auto results = resolver.resolve(host, port, boost::asio::ip::tcp::resolver::canonical_name, ec);
    CHECK_AND_ASSERT_MES(!ec && !results.empty(), false, "Failed to resolve host name '" << host << "': " << ec.message() << ':' << ec.value());
 
    for (const auto& result : results)
    {
      const auto& endpoint = result.endpoint();
      if (endpoint.address().is_v4())
      {
        epee::net_utils::network_address na{epee::net_utils::ipv4_network_address{boost::asio::detail::socket_ops::host_to_network_long(endpoint.address().to_v4().to_uint()), endpoint.port()}};
        seed_nodes.push_back(na);
        MINFO("Added node: " << na.str());
      }
      else
      {
        epee::net_utils::network_address na{epee::net_utils::ipv6_network_address{endpoint.address().to_v6(), endpoint.port()}};
        seed_nodes.push_back(na);
        MINFO("Added node: " << na.str());
      }
    }
    return true;
  }
 
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  std::set<std::string> node_server<t_payload_net_handler>::get_ip_seed_nodes() const
  {
    std::set<std::string> full_addrs;
    if (m_nettype == cryptonote::TESTNET)
    {
      full_addrs.insert("176.9.0.187:28080");
      full_addrs.insert("192.99.8.110:28080");
      full_addrs.insert("37.187.74.171:28080");
      full_addrs.insert("88.99.195.15:28080");
      full_addrs.insert("5.104.84.64:28080");
    }
    else if (m_nettype == cryptonote::STAGENET)
    {
      full_addrs.insert("176.9.0.187:38080");
      full_addrs.insert("192.99.8.110:38080");
      full_addrs.insert("37.187.74.171:38080");
      full_addrs.insert("88.99.195.15:38080");
      full_addrs.insert("5.104.84.64:38080");
    }
    else if (m_nettype == cryptonote::FAKECHAIN)
    {
    }
    else
    {
      full_addrs.insert("176.9.0.187:18080");
      full_addrs.insert("88.198.163.90:18080");
      full_addrs.insert("192.99.8.110:18080");
      full_addrs.insert("37.187.74.171:18080");
      full_addrs.insert("88.99.195.15:18080");
      full_addrs.insert("5.104.84.64:18080");
    }
    return full_addrs;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  std::set<std::string> node_server<t_payload_net_handler>::get_dns_seed_nodes()
  {
    if (!m_exclusive_peers.empty() || m_offline)
    {
      return {};
    }
    if (m_nettype == cryptonote::TESTNET)
    {
      return get_ip_seed_nodes();
    }
    if (m_nettype == cryptonote::STAGENET)
    {
      return get_ip_seed_nodes();
    }
    if (m_nettype == cryptonote::FAKECHAIN)
    {
      return {};
    }
    if (!m_enable_dns_seed_nodes)
    {
      // TODO: a domain can be set through socks, so that the remote side does the lookup for the DNS seed nodes.
      m_fallback_seed_nodes_added.test_and_set();
      return get_ip_seed_nodes();
    }
 
    std::set<std::string> full_addrs;
 
    // for each hostname in the seed nodes list, attempt to DNS resolve and
    // add the result addresses as seed nodes
    // TODO: at some point add IPv6 support, but that won't be relevant
    // for some time yet.
 
    struct frame_t
    {
      std::vector<std::vector<std::string>> dns_results;
      boost::mutex sync;
    };
 
    const auto frame = std::make_shared<frame_t>();
    frame->dns_results.resize(m_seed_nodes_list.size());
 
    // some libc implementation provide only a very small stack
    // for threads, e.g. musl only gives +- 80kb, which is not
    // enough to do a resolve with unbound. we request a stack
    // of 1 mb, which should be plenty
    boost::thread::attributes thread_attributes;
    thread_attributes.set_stack_size(1024*1024);
 
    std::list<boost::thread> dns_threads;
    uint64_t result_index = 0;
    const std::weak_ptr<frame_t> frame_weak{frame};
    for (const std::string& addr_str : m_seed_nodes_list)
    {
      boost::thread th = boost::thread(thread_attributes, [frame_weak, addr_str, result_index]
      {
        MDEBUG("dns_threads[" << result_index << "] created for: " << addr_str);
        // TODO: care about dnssec avail/valid
        bool avail, valid;
        std::vector<std::string> addr_list = tools::DNSResolver::instance().get_ipv4(addr_str, avail, valid);
        MINFO("dns_threads[" << result_index << "] addr_str: " << addr_str << "  number of results: " << addr_list.size());
        const auto frame = frame_weak.lock();
        if (frame)
        {
          const boost::lock_guard<boost::mutex> lock{frame->sync};
          frame->dns_results.at(result_index) = std::move(addr_list);
        }
      });
 
      dns_threads.push_back(std::move(th));
      ++result_index;
    }
 
    MDEBUG("dns_threads created, now waiting for completion or timeout of " << CRYPTONOTE_DNS_TIMEOUT_MS << "ms");
    boost::chrono::system_clock::time_point deadline = boost::chrono::system_clock::now() + boost::chrono::milliseconds(CRYPTONOTE_DNS_TIMEOUT_MS);
    uint64_t i = 0;
    for (boost::thread& th : dns_threads)
    {
      if (! th.try_join_until(deadline))
      {
        MWARNING("dns_threads[" << i << "] timed out");
        th.detach();
      }
      ++i;
    }
 
    i = 0;
    const boost::lock_guard<boost::mutex> lock{frame->sync};
    for (const auto& result : frame->dns_results)
    {
      MDEBUG("DNS lookup for " << m_seed_nodes_list[i] << ": " << result.size() << " results");
      // if no results for node, thread's lookup likely timed out
      if (result.size())
      {
        for (const auto& addr_string : result)
          full_addrs.insert(addr_string + ":" + std::to_string(cryptonote::get_config(m_nettype).P2P_DEFAULT_PORT));
      }
      ++i;
    }
 
    // append the fallback nodes if we have too few seed nodes to start with
    if (full_addrs.size() < MIN_WANTED_SEED_NODES)
    {
      if (full_addrs.empty())
        MINFO("DNS seed node lookup either timed out or failed, falling back to defaults");
      else
        MINFO("Not enough DNS seed nodes found, using fallback defaults too");
 
      for (const auto &peer: get_ip_seed_nodes())
        full_addrs.insert(peer);
      m_fallback_seed_nodes_added.test_and_set();
    }
 
    return full_addrs;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  std::set<std::string> node_server<t_payload_net_handler>::get_seed_nodes(epee::net_utils::zone zone)
  {
    switch (zone)
    {
    case epee::net_utils::zone::public_:
      return get_dns_seed_nodes();
    case epee::net_utils::zone::tor:
      if (m_nettype == cryptonote::MAINNET)
      {
        return {
          "zbjkbsxc5munw3qusl7j2hpcmikhqocdf4pqhnhtpzw5nt5jrmofptid.onion:18083",
          "plowsof3t5hogddwabaeiyrno25efmzfxyro2vligremt7sxpsclfaid.onion:18083",
          "plowsoffjexmxalw73tkjmf422gq6575fc7vicuu4javzn2ynnte6tyd.onion:18083",
          "plowsofe6cleftfmk2raiw5h2x66atrik3nja4bfd3zrfa2hdlgworad.onion:18083",
          "aclc4e2jhhtr44guufbnwk5bzwhaecinax4yip4wr4tjn27sjsfg6zqd.onion:18083",
          "lykcas4tus7mkm4bhsgqe4drtd4awi7gja24goscc47xfgzj54yofyqd.onion:18083",
        };
      }
      return {};
    case epee::net_utils::zone::i2p:
      if (m_nettype == cryptonote::MAINNET)
      {
        return {
          "uqj3aphckqtjsitz7kxx5flqpwjlq5ppr3chazfued7xucv3nheq.b32.i2p",
          "vdmnehdjkpkg57nthgnjfuaqgku673r5bpbqg56ix6fyqoywgqrq.b32.i2p",
          "ugnlcdciyhghh2zert7c3kl4biwkirc43ke33jiy5slnd3mv2trq.b32.i2p",
        };
      }
      return {};
    default:
      break;
    }
    throw std::logic_error{"Bad zone given to get_seed_nodes"};
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  typename node_server<t_payload_net_handler>::network_zone& node_server<t_payload_net_handler>::add_zone(const epee::net_utils::zone zone)
  {
    const auto zone_ = m_network_zones.lower_bound(zone);
    if (zone_ != m_network_zones.end() && zone_->first == zone)
      return zone_->second;
 
    network_zone& public_zone = m_network_zones[epee::net_utils::zone::public_];
    return m_network_zones.emplace_hint(zone_, std::piecewise_construct, std::make_tuple(zone), std::tie(public_zone.m_net_server.get_io_context()))->second;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::init(const boost::program_options::variables_map& vm, const std::string& proxy, bool proxy_dns_leaks_allowed)
  {
    bool res = handle_command_line(vm);
    CHECK_AND_ASSERT_MES(res, false, "Failed to handle command line");
    if (proxy.size())
    {
      const auto endpoint = net::socks::endpoint::get(proxy);
      CHECK_AND_ASSERT_MES(endpoint, false, "Failed to parse proxy: " << proxy << " - " << endpoint.error().message());
      network_zone& public_zone = m_network_zones[epee::net_utils::zone::public_];
      public_zone.m_connect = &socks_connect;
      public_zone.m_proxy_address = *endpoint;
      public_zone.m_can_pingback = false;
      m_enable_dns_seed_nodes &= proxy_dns_leaks_allowed;
      m_enable_dns_blocklist &= proxy_dns_leaks_allowed;
    }
 
    if (m_nettype == cryptonote::TESTNET)
    {
      memcpy(&m_network_id, &::config::testnet::NETWORK_ID, 16);
    }
    else if (m_nettype == cryptonote::STAGENET)
    {
      memcpy(&m_network_id, &::config::stagenet::NETWORK_ID, 16);
    }
    else
    {
      memcpy(&m_network_id, &::config::NETWORK_ID, 16);
    }
 
    m_config_folder = command_line::get_arg(vm, cryptonote::arg_data_dir);
    network_zone& public_zone = m_network_zones.at(epee::net_utils::zone::public_);
 
    if ((m_nettype == cryptonote::MAINNET && public_zone.m_port != std::to_string(::config::P2P_DEFAULT_PORT))
        || (m_nettype == cryptonote::TESTNET && public_zone.m_port != std::to_string(::config::testnet::P2P_DEFAULT_PORT))
        || (m_nettype == cryptonote::STAGENET && public_zone.m_port != std::to_string(::config::stagenet::P2P_DEFAULT_PORT))) {
      m_config_folder = m_config_folder + "/" + public_zone.m_port;
    }
 
    res = init_config();
    CHECK_AND_ASSERT_MES(res, false, "Failed to init config.");
 
    for (auto& zone : m_network_zones)
    {
      res = zone.second.m_peerlist.init(m_peerlist_storage.take_zone(zone.first), m_allow_local_ip);
      CHECK_AND_ASSERT_MES(res, false, "Failed to init peerlist.");
    }
 
    for(const auto& p: m_command_line_peers)
      m_network_zones.at(p.adr.get_zone()).m_peerlist.append_with_peer_white(p);
 
    //only in case if we really sure that we have external visible ip
    m_have_address = true;
 
    //configure self
 
    public_zone.m_net_server.set_threads_prefix("P2P"); // all zones use these threads/asio::io_service
 
    // from here onwards, it's online stuff
    if (m_offline)
      return res;
 
    //try to bind
    m_ssl_support = epee::net_utils::ssl_support_t::e_ssl_support_disabled;
    for (auto& zone : m_network_zones)
    {
      zone.second.m_net_server.get_config_object().set_handler(this);
      zone.second.m_net_server.get_config_object().m_invoke_timeout = P2P_DEFAULT_INVOKE_TIMEOUT;
 
      if (!zone.second.m_bind_ip.empty())
      {
        std::string ipv6_addr = "";
        std::string ipv6_port = "";
        zone.second.m_net_server.set_connection_filter(this);
        zone.second.m_net_server.set_connection_limit(this);
        MINFO("Binding (IPv4) on " << zone.second.m_bind_ip << ":" << zone.second.m_port);
        if (!zone.second.m_bind_ipv6_address.empty() && m_use_ipv6)
        {
          ipv6_addr = zone.second.m_bind_ipv6_address;
          ipv6_port = zone.second.m_port_ipv6;
          MINFO("Binding (IPv6) on " << zone.second.m_bind_ipv6_address << ":" << zone.second.m_port_ipv6);
        }
        res = zone.second.m_net_server.init_server(zone.second.m_port, zone.second.m_bind_ip, ipv6_port, ipv6_addr, m_use_ipv6, m_require_ipv4, epee::net_utils::ssl_support_t::e_ssl_support_disabled);
        CHECK_AND_ASSERT_MES(res, false, "Failed to bind server");
      }
    }
 
    m_listening_port = public_zone.m_net_server.get_binded_port();
    MLOG_GREEN(el::Level::Info, "Net service bound (IPv4) to " << public_zone.m_bind_ip << ":" << m_listening_port);
    if (m_use_ipv6)
    {
      m_listening_port_ipv6 = public_zone.m_net_server.get_binded_port_ipv6();
      MLOG_GREEN(el::Level::Info, "Net service bound (IPv6) to " << public_zone.m_bind_ipv6_address << ":" << m_listening_port_ipv6);
    }
    if(m_external_port)
      MDEBUG("External port defined as " << m_external_port);
 
    return res;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  typename node_server<t_payload_net_handler>::payload_net_handler& node_server<t_payload_net_handler>::get_payload_object()
  {
    return m_payload_handler;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::run()
  {
    // creating thread to log number of connections
    mPeersLoggerThread.reset(new boost::thread([&]()
    {
      _note("Thread monitor number of peers - start");
      const network_zone& public_zone = m_network_zones.at(epee::net_utils::zone::public_);
      while (!is_closing && !public_zone.m_net_server.is_stop_signal_sent())
      { // main loop of thread
        //number_of_peers = m_net_server.get_config_object().get_connections_count();
        for (auto& zone : m_network_zones)
        {
          unsigned int number_of_in_peers = 0;
          unsigned int number_of_out_peers = 0;
          zone.second.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
          {
            if (cntxt.m_is_income)
            {
              ++number_of_in_peers;
            }
            else if (!cntxt.is_ping)
            {
              ++number_of_out_peers;
            }
            return true;
          }); // lambda
          zone.second.m_current_number_of_in_peers = number_of_in_peers;
          zone.second.m_current_number_of_out_peers = number_of_out_peers;
        }
        boost::this_thread::sleep_for(boost::chrono::seconds(1));
      } // main loop of thread
      _note("Thread monitor number of peers - done");
    })); // lambda
 
    network_zone& public_zone = m_network_zones.at(epee::net_utils::zone::public_);
    public_zone.m_net_server.add_idle_handler(boost::bind(&node_server<t_payload_net_handler>::idle_worker, this), 1000);
    public_zone.m_net_server.add_idle_handler(boost::bind(&t_payload_net_handler::on_idle, &m_payload_handler), 1000);
 
    //here you can set worker threads count
    int thrds_count = 10;
    boost::thread::attributes attrs;
    attrs.set_stack_size(THREAD_STACK_SIZE);
    //go to loop
    MINFO("Run net_service loop( " << thrds_count << " threads)...");
    if(!public_zone.m_net_server.run_server(thrds_count, true, attrs))
    {
      LOG_ERROR("Failed to run net tcp server!");
    }
 
    MINFO("net_service loop stopped.");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  uint64_t node_server<t_payload_net_handler>::get_public_connections_count()
  {
    auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone == m_network_zones.end())
      return 0;
    return public_zone->second.m_net_server.get_config_object().get_connections_count();
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::deinit()
  {
    kill();
 
    if (!m_offline)
    {
      for(auto& zone : m_network_zones)
        zone.second.m_net_server.deinit_server();
    }
    return store_config();
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::store_config()
  {
    TRY_ENTRY();
 
    if (!tools::create_directories_if_necessary(m_config_folder))
    {
      MWARNING("Failed to create data directory \"" << m_config_folder);
      return false;
    }
 
    peerlist_types active{};
    for (auto& zone : m_network_zones)
      zone.second.m_peerlist.get_peerlist(active);
 
    const std::string state_file_path = m_config_folder + "/" + P2P_NET_DATA_FILENAME;
    if (!m_peerlist_storage.store(state_file_path, active))
    {
      MWARNING("Failed to save config to file " << state_file_path);
      return false;
    }
    CATCH_ENTRY_L0("node_server::store", false);
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::send_stop_signal()
  {
    MDEBUG("[node] stopping server payload handler");
    m_payload_handler.stop();
    MDEBUG("[node] sending stop signal");
    for (auto& zone : m_network_zones)
    {
      const auto close_all_connections = [&, this]()
      {
        std::list<boost::uuids::uuid> connection_ids;
        zone.second.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt) {
          connection_ids.push_back(cntxt.m_connection_id);
          return true;
        });
        for (const auto &connection_id: connection_ids)
        {
          MDEBUG("Closing connection " << connection_id);
          // We need to wait for every connection's shutdown sequence to complete before stopping the io_context.
          zone.second.m_net_server.get_config_object().close(connection_id, true/*wait_for_shutdown*/);
          MDEBUG("Closed connection " << connection_id);
        }
      };
 
      zone.second.m_net_server.send_stop_signal(close_all_connections);
    }
    MDEBUG("[node] Stop signal sent");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::do_handshake_with_peer(peerid_type& pi, p2p_connection_context& context_, bool just_take_peerlist)
  {
    network_zone& zone = m_network_zones.at(context_.m_remote_address.get_zone());
 
    typename COMMAND_HANDSHAKE::request arg;
    typename COMMAND_HANDSHAKE::response rsp;
    get_local_node_data(arg.node_data, zone);
    m_payload_handler.get_payload_sync_data(arg.payload_data);
 
    epee::simple_event ev;
    std::atomic<bool> hsh_result(false);
    bool timeout = false;
 
    bool r = epee::net_utils::async_invoke_remote_command2<typename COMMAND_HANDSHAKE::response>(context_, COMMAND_HANDSHAKE::ID, arg, zone.m_net_server.get_config_object(),
      [this, &pi, &ev, &hsh_result, &just_take_peerlist, &context_, &timeout](int code, const typename COMMAND_HANDSHAKE::response& rsp, p2p_connection_context& context)
    {
      epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){ev.raise();});
 
      if(code < 0)
      {
        LOG_WARNING_CC(context, "COMMAND_HANDSHAKE invoke failed. (" << code <<  ", " << epee::levin::get_err_descr(code) << ")");
        if (code == LEVIN_ERROR_CONNECTION_TIMEDOUT || code == LEVIN_ERROR_CONNECTION_DESTROYED)
          timeout = true;
        return;
      }
 
      if(rsp.node_data.network_id != m_network_id)
      {
        LOG_WARNING_CC(context, "COMMAND_HANDSHAKE Failed, wrong network!  (" << rsp.node_data.network_id << "), closing connection.");
        return;
      }
 
      if(!handle_remote_peerlist(rsp.local_peerlist_new, context))
      {
        LOG_WARNING_CC(context, "COMMAND_HANDSHAKE: failed to handle_remote_peerlist(...), closing connection.");
        add_host_fail(context.m_remote_address);
        return;
      }
      hsh_result = true;
      if(!just_take_peerlist)
      {
        if(!m_payload_handler.process_payload_sync_data(rsp.payload_data, context, true))
        {
          LOG_WARNING_CC(context, "COMMAND_HANDSHAKE invoked, but process_payload_sync_data returned false, dropping connection.");
          hsh_result = false;
          return;
        }
 
        pi = context.peer_id = rsp.node_data.peer_id;
        context.m_rpc_port = rsp.node_data.rpc_port;
        context.m_rpc_credits_per_hash = rsp.node_data.rpc_credits_per_hash;
        context.support_flags = rsp.node_data.support_flags;
        const auto azone = context.m_remote_address.get_zone();
        network_zone& zone = m_network_zones.at(azone);
        zone.m_peerlist.set_peer_just_seen(rsp.node_data.peer_id, context.m_remote_address, context.m_pruning_seed, context.m_rpc_port, context.m_rpc_credits_per_hash);
 
        // move
        if(azone == epee::net_utils::zone::public_ && rsp.node_data.peer_id == zone.m_config.m_peer_id)
        {
          LOG_DEBUG_CC(context, "Connection to self detected, dropping connection");
          hsh_result = false;
          return;
        }
        LOG_INFO_CC(context, "New connection handshaked, pruning seed " << epee::string_tools::to_string_hex(context.m_pruning_seed));
        LOG_DEBUG_CC(context, " COMMAND_HANDSHAKE INVOKED OK");
      }else
      {
        LOG_DEBUG_CC(context, " COMMAND_HANDSHAKE(AND CLOSE) INVOKED OK");
      }
      context_ = context;
    }, P2P_DEFAULT_HANDSHAKE_INVOKE_TIMEOUT);
 
    if(r)
    {
      ev.wait();
    }
 
    if(!hsh_result)
    {
      LOG_WARNING_CC(context_, "COMMAND_HANDSHAKE Failed");
      if (!timeout)
        zone.m_net_server.get_config_object().close(context_.m_connection_id, false);
    }
    else if (!just_take_peerlist)
    {
      if (context_.support_flags == 0)
        try_get_support_flags(context_, [](p2p_connection_context& flags_context, const uint32_t& support_flags) 
        {
          flags_context.support_flags = support_flags;
        });
    }
 
    return hsh_result;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::do_peer_timed_sync(const epee::net_utils::connection_context_base& context_, peerid_type peer_id)
  {
    typename COMMAND_TIMED_SYNC::request arg = AUTO_VAL_INIT(arg);
    m_payload_handler.get_payload_sync_data(arg.payload_data);
 
    network_zone& zone = m_network_zones.at(context_.m_remote_address.get_zone());
    bool r = epee::net_utils::async_invoke_remote_command2<typename COMMAND_TIMED_SYNC::response>(context_, COMMAND_TIMED_SYNC::ID, arg, zone.m_net_server.get_config_object(),
      [this](int code, const typename COMMAND_TIMED_SYNC::response& rsp, p2p_connection_context& context)
    {
      context.m_in_timedsync = false;
      if(code < 0)
      {
        LOG_WARNING_CC(context, "COMMAND_TIMED_SYNC invoke failed. (" << code <<  ", " << epee::levin::get_err_descr(code) << ")");
        return;
      }
 
      if(!handle_remote_peerlist(rsp.local_peerlist_new, context))
      {
        LOG_WARNING_CC(context, "COMMAND_TIMED_SYNC: failed to handle_remote_peerlist(...), closing connection.");
        m_network_zones.at(context.m_remote_address.get_zone()).m_net_server.get_config_object().close(context.m_connection_id, false);
        add_host_fail(context.m_remote_address);
      }
      if(!context.m_is_income)
        m_network_zones.at(context.m_remote_address.get_zone()).m_peerlist.set_peer_just_seen(context.peer_id, context.m_remote_address, context.m_pruning_seed, context.m_rpc_port, context.m_rpc_credits_per_hash);
      if (!m_payload_handler.process_payload_sync_data(rsp.payload_data, context, false))
      {
        m_network_zones.at(context.m_remote_address.get_zone()).m_net_server.get_config_object().close(context.m_connection_id, false);
      }
    });
 
    if(!r)
    {
      LOG_WARNING_CC(context_, "COMMAND_TIMED_SYNC Failed");
      return false;
    }
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_random_index_with_fixed_probability(size_t max_index)
  {
    //divide by zero workaround
    if(!max_index)
      return 0;
 
    size_t x = crypto::rand<size_t>()%(16*max_index+1);
    size_t res = (x*x*x)/(max_index*max_index*16*16*16); //parabola \/
    MDEBUG("Random connection index=" << res << "(x="<< x << ", max_index=" << max_index << ")");
    return res;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::is_peer_used(const peerlist_entry& peer)
  {
    const auto zone = peer.adr.get_zone();
    const auto server = m_network_zones.find(zone);
    if (server == m_network_zones.end())
      return false;
 
    const bool is_public = (zone == epee::net_utils::zone::public_);
    if(is_public && server->second.m_config.m_peer_id == peer.id)
      return true;//dont make connections to ourself
 
    bool used = false;
    server->second.m_net_server.get_config_object().foreach_connection([&, is_public](const p2p_connection_context& cntxt)
    {
      if((is_public && cntxt.peer_id == peer.id && peer.adr.is_same_host(cntxt.m_remote_address)) || (!cntxt.m_is_income && peer.adr == cntxt.m_remote_address))
      {
        used = true;
        return false;//stop enumerating
      }
      return true;
    });
    return used;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::is_peer_used(const anchor_peerlist_entry& peer)
  {
    const auto zone = peer.adr.get_zone();
    const auto server = m_network_zones.find(zone);
    if (server == m_network_zones.end())
      return false;
 
    const bool is_public = (zone == epee::net_utils::zone::public_);
    if(is_public && server->second.m_config.m_peer_id == peer.id)
      return true;//dont make connections to ourself
 
    bool used = false;
    server->second.m_net_server.get_config_object().foreach_connection([&, is_public](const p2p_connection_context& cntxt)
    {
      if((is_public && cntxt.peer_id == peer.id && peer.adr.is_same_host(cntxt.m_remote_address)) || (!cntxt.m_is_income && peer.adr == cntxt.m_remote_address))
      {
        used = true;
        return false;//stop enumerating
      }
      return true;
    });
    return used;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::is_addr_connected(const epee::net_utils::network_address& peer)
  {
    const auto zone = m_network_zones.find(peer.get_zone());
    if (zone == m_network_zones.end())
      return false;
 
    bool connected = false;
    zone->second.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
    {
      if(!cntxt.m_is_income && peer == cntxt.m_remote_address)
      {
        connected = true;
        return false;//stop enumerating
      }
      return true;
    });
 
    return connected;
  }
 
#define LOG_PRINT_CC_PRIORITY_NODE(priority, con, msg) \
  do { \
    if (priority) {\
      LOG_INFO_CC(con, "[priority]" << msg); \
    } else {\
      LOG_INFO_CC(con, msg); \
    } \
  } while(0)
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::try_to_connect_and_handshake_with_new_peer(const epee::net_utils::network_address& na, bool just_take_peerlist, uint64_t last_seen_stamp, PeerType peer_type, uint64_t first_seen_stamp)
  {
    network_zone& zone = m_network_zones.at(na.get_zone());
    if (zone.m_connect == nullptr) // outgoing connections in zone not possible
      return false;
 
    if (zone.m_our_address == na)
      return false;
 
    if (zone.m_current_number_of_out_peers == zone.m_config.m_net_config.max_out_connection_count) // out peers limit
    {
      return false;
    }
    else if (zone.m_current_number_of_out_peers > zone.m_config.m_net_config.max_out_connection_count)
    {
      zone.m_net_server.get_config_object().del_out_connections(1);
      --(zone.m_current_number_of_out_peers); // atomic variable, update time = 1s
      return false;
    }
 
 
    MDEBUG("Connecting to " << na.str() << " (peer_type=" << peer_type << ", last_seen: "
        << (last_seen_stamp ? epee::misc_utils::get_time_interval_string(time(NULL) - last_seen_stamp):"never")
        << ")...");
 
    auto con = zone.m_connect(zone, na, m_ssl_support);
    if(!con)
    {
      bool is_priority = is_priority_node(na);
      LOG_PRINT_CC_PRIORITY_NODE(is_priority, bool(con), "Connect failed to " << na.str()
        /*<< ", try " << try_count*/);
      record_addr_failed(na);
      return false;
    }
 
    con->m_anchor = peer_type == anchor;
    peerid_type pi = AUTO_VAL_INIT(pi);
    bool res = do_handshake_with_peer(pi, *con, just_take_peerlist);
 
    if(!res)
    {
      bool is_priority = is_priority_node(na);
      LOG_PRINT_CC_PRIORITY_NODE(is_priority, *con, "Failed to HANDSHAKE with peer "
        << na.str()
        /*<< ", try " << try_count*/);
      record_addr_failed(na);
      return false;
    }
 
    if(just_take_peerlist)
    {
      zone.m_net_server.get_config_object().close(con->m_connection_id, false);
      LOG_DEBUG_CC(*con, "CONNECTION HANDSHAKED OK AND CLOSED.");
      return true;
    }
 
    peerlist_entry pe_local = AUTO_VAL_INIT(pe_local);
    pe_local.adr = na;
    pe_local.id = pi;
    time_t last_seen;
    time(&last_seen);
    pe_local.last_seen = static_cast<int64_t>(last_seen);
    pe_local.pruning_seed = con->m_pruning_seed;
    pe_local.rpc_port = con->m_rpc_port;
    pe_local.rpc_credits_per_hash = con->m_rpc_credits_per_hash;
    zone.m_peerlist.append_with_peer_white(pe_local);
    //update last seen and push it to peerlist manager
 
    anchor_peerlist_entry ape = AUTO_VAL_INIT(ape);
    ape.adr = na;
    ape.id = pi;
    ape.first_seen = first_seen_stamp ? first_seen_stamp : time(nullptr);
 
    zone.m_peerlist.append_with_peer_anchor(ape);
    zone.m_notifier.on_handshake_complete(con->m_connection_id, con->m_is_income);
    zone.m_notifier.new_out_connection();
 
    LOG_DEBUG_CC(*con, "CONNECTION HANDSHAKED OK.");
    return true;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::check_connection_and_handshake_with_peer(const epee::net_utils::network_address& na, uint64_t last_seen_stamp)
  {
    network_zone& zone = m_network_zones.at(na.get_zone());
    if (zone.m_connect == nullptr)
      return false;
 
    LOG_PRINT_L1("Connecting to " << na.str() << "(last_seen: "
                                  << (last_seen_stamp ? epee::misc_utils::get_time_interval_string(time(NULL) - last_seen_stamp):"never")
                                  << ")...");
 
    auto con = zone.m_connect(zone, na, m_ssl_support);
    if (!con) {
      bool is_priority = is_priority_node(na);
 
      LOG_PRINT_CC_PRIORITY_NODE(is_priority, p2p_connection_context{}, "Connect failed to " << na.str());
      record_addr_failed(na);
 
      return false;
    }
 
    con->m_anchor = false;
    peerid_type pi = AUTO_VAL_INIT(pi);
    const bool res = do_handshake_with_peer(pi, *con, true);
    if (!res) {
      bool is_priority = is_priority_node(na);
 
      LOG_PRINT_CC_PRIORITY_NODE(is_priority, *con, "Failed to HANDSHAKE with peer " << na.str());
      record_addr_failed(na);
      return false;
    }
 
    zone.m_net_server.get_config_object().close(con->m_connection_id, false);
 
    LOG_DEBUG_CC(*con, "CONNECTION HANDSHAKED OK AND CLOSED.");
 
    return true;
  }
 
#undef LOG_PRINT_CC_PRIORITY_NODE
 
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::record_addr_failed(const epee::net_utils::network_address& addr)
  {
    CRITICAL_REGION_LOCAL(m_conn_fails_cache_lock);
    m_conn_fails_cache[addr.host_str()] = time(NULL);
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::is_addr_recently_failed(const epee::net_utils::network_address& addr)
  {
    CRITICAL_REGION_LOCAL(m_conn_fails_cache_lock);
    auto it = m_conn_fails_cache.find(addr.host_str());
    if(it == m_conn_fails_cache.end())
      return false;
 
    if(time(NULL) - it->second > P2P_FAILED_ADDR_FORGET_SECONDS)
      return false;
    else
      return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::make_new_connection_from_anchor_peerlist(const std::vector<anchor_peerlist_entry>& anchor_peerlist)
  {
    for (const auto& pe: anchor_peerlist) {
      _note("Considering connecting (out) to anchor peer: " << peerid_to_string(pe.id) << " " << pe.adr.str());
 
      if(is_peer_used(pe)) {
        _note("Peer is used");
        continue;
      }
 
      if(!is_remote_host_allowed(pe.adr)) {
        continue;
      }
 
      if(is_addr_recently_failed(pe.adr)) {
        continue;
      }
 
      MDEBUG("Selected peer: " << peerid_to_string(pe.id) << " " << pe.adr.str()
                               << "[peer_type=" << anchor
                               << "] first_seen: " << epee::misc_utils::get_time_interval_string(time(NULL) - pe.first_seen));
 
      if(!try_to_connect_and_handshake_with_new_peer(pe.adr, false, 0, anchor, pe.first_seen)) {
        _note("Handshake failed");
        continue;
      }
 
      return true;
    }
 
    return false;
  }
  //-----------------------------------------------------------------------------------
  // Find a single candidate from the given peer list in the given zone and connect to it if possible
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::make_new_connection_from_peerlist(network_zone& zone, bool use_white_list)
  {
 
    // Local helper method to get the host string, i.e. the pure IP address without port
    const auto get_host_string = [](const epee::net_utils::network_address &address) {
      if (address.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id())
      {
        const boost::asio::ip::address_v6 actual_ip = address.as<const epee::net_utils::ipv6_network_address>().ip();
        if (actual_ip.is_v4_mapped())
        {
          boost::asio::ip::address_v4 v4ip = make_address_v4_from_v6(actual_ip);
          uint32_t actual_ipv4;
          memcpy(&actual_ipv4, v4ip.to_bytes().data(), sizeof(actual_ipv4));
          return epee::net_utils::ipv4_network_address(actual_ipv4, 0).host_str();
        }
      }
      return address.host_str();
    };
 
    // Get the current list of known peers of the desired kind, ordered by 'last_seen'.
    // Deduplicate ports right away, i.e. if we know several peers on the same host address but
    // with different ports, take only one of them, to avoid giving such peers undue weight
    // and make it impossible to game peer selection by advertising on a large number of ports.
    // Making this list also insulates us from any changes that may happen to the original list
    // while we are working here, and allows an easy retry in the inner try loop.
    std::vector<peerlist_entry> peers;
    std::unordered_set<std::string> hosts;
    size_t total_peers_size = 0;
    zone.m_peerlist.foreach(use_white_list, [&peers, &hosts, &total_peers_size, &get_host_string](const peerlist_entry &peer)
    {
      ++total_peers_size;
      const std::string host_string = get_host_string(peer.adr);
      if (hosts.insert(host_string).second)
      {
        peers.push_back(peer);
      }
      // else ignore this additional peer on the same IP number
 
      return true;
    });
 
    const size_t peers_size = peers.size();
    MDEBUG("Looking at " << peers_size << " port-deduplicated peers out of " << total_peers_size
      << ", i.e. dropping " << (total_peers_size - peers_size));
 
    std::set<uint64_t> tried_peers;  // all peers ever tried
 
    // Outer try loop, with up to 3 attempts to actually connect to a suitable randomly choosen candidate
    size_t outer_loop_count = 0;
    while ((outer_loop_count < 3) && !zone.m_net_server.is_stop_signal_sent())
    {
      ++outer_loop_count;
 
      const uint32_t next_needed_pruning_stripe = m_payload_handler.get_next_needed_pruning_stripe().second;
 
      // Build a list of all distinct /24 subnets we are connected to now right now; to catch
      // any connection changes, re-build the list for every outer try loop pass
      std::set<uint32_t> connected_subnets;
      const uint32_t subnet_mask = ntohl(0xffffff00);
      const bool is_public_zone = &zone == &m_network_zones.at(epee::net_utils::zone::public_);
      if (is_public_zone)
      {
        zone.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
        {
          if (cntxt.m_remote_address.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id())
          {
            const epee::net_utils::network_address na = cntxt.m_remote_address;
            const uint32_t actual_ip = na.as<const epee::net_utils::ipv4_network_address>().ip();
            connected_subnets.insert(actual_ip & subnet_mask);
          }
          else if (cntxt.m_remote_address.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id())
          {
            const epee::net_utils::network_address na = cntxt.m_remote_address;
            const boost::asio::ip::address_v6 &actual_ip = na.as<const epee::net_utils::ipv6_network_address>().ip();
            if (actual_ip.is_v4_mapped())
            {
              boost::asio::ip::address_v4 v4ip = make_address_v4_from_v6(actual_ip);
              uint32_t actual_ipv4;
              memcpy(&actual_ipv4, v4ip.to_bytes().data(), sizeof(actual_ipv4));
              connected_subnets.insert(actual_ipv4 & subnet_mask);
            }
          }
          return true;
        });
      }
 
      std::vector<peerlist_entry> subnet_peers;
      std::vector<peerlist_entry> filtered;
 
      // Inner try loop: Find candidates first with subnet deduplication, if none found again without.
      // Finding none happens if all candidates are from subnets we are already connected to and/or
      // they don't offer the needed stripe when pruning. Only actually loop and deduplicate if we are
      // in the public zone because private zones don't have subnets.
      for (int step = 0; step < 2; ++step)
      {
        if ((step == 1) && !is_public_zone)
          break;
 
        const bool try_subnet_dedup = step == 0 && is_public_zone;
        const std::vector<peerlist_entry> &candidate_peers = try_subnet_dedup ? subnet_peers : peers;
        if (try_subnet_dedup)
        {
          // Deduplicate subnets using 3 steps
 
          // Step 1: Prepare to access the peers in a random order
          std::vector<size_t> shuffled_indexes(peers.size());
          std::iota(shuffled_indexes.begin(), shuffled_indexes.end(), 0);
          std::shuffle(shuffled_indexes.begin(), shuffled_indexes.end(), crypto::random_device{});
 
          // Step 2: Deduplicate by only taking 1 candidate from each /24 subnet that occurs, the FIRST
          // candidate seen from each subnet within the now random order
          std::set<uint32_t> subnets = connected_subnets;
          for (size_t index : shuffled_indexes)
          {
            const peerlist_entry &peer = peers.at(index);
            bool take = true;
            if (peer.adr.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id())
            {
              const epee::net_utils::network_address na = peer.adr;
              const uint32_t actual_ip = na.as<const epee::net_utils::ipv4_network_address>().ip();
              const uint32_t subnet = actual_ip & subnet_mask;
              take = subnets.find(subnet) == subnets.end();
              if (take)
                // This subnet is now "occupied", don't take any more candidates from this one
                subnets.insert(subnet);
            }
            else if (peer.adr.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id())
            {
              const epee::net_utils::network_address na = peer.adr;
              const boost::asio::ip::address_v6 &actual_ip = na.as<const epee::net_utils::ipv6_network_address>().ip();
              if (actual_ip.is_v4_mapped())
              {
                boost::asio::ip::address_v4 v4ip = make_address_v4_from_v6(actual_ip);
                uint32_t actual_ipv4;
                memcpy(&actual_ipv4, v4ip.to_bytes().data(), sizeof(actual_ipv4));
                uint32_t subnet = actual_ipv4 & subnet_mask;
                take = subnets.find(subnet) == subnets.end();
                if (take)
                  subnets.insert(subnet);
              }
              // else 'take' stays true, we will take an IPv6 address that is not V4 mapped
            }
            if (take)
              subnet_peers.push_back(peer);
          }
 
          // Step 3: Put back into order according to 'last_seen', i.e. most recently seen first
          std::sort(subnet_peers.begin(), subnet_peers.end(), [](const peerlist_entry &a, const peerlist_entry &b)
          {
            return a.last_seen > b.last_seen;
          });
 
          const size_t subnet_peers_size = subnet_peers.size();
          MDEBUG("Looking at " << subnet_peers_size << " subnet-deduplicated peers out of " << peers_size
            << ", i.e. dropping " << (peers_size - subnet_peers_size));
        } // deduplicate
        // else, for step 1 / second pass of inner try loop, take all peers from all subnets
 
        // Take as many candidates as we need and care about stripes if pruning
        const size_t limit = use_white_list ? 20 : std::numeric_limits<size_t>::max();
        for (const peerlist_entry &peer : candidate_peers) {
          if (filtered.size() >= limit)
            break;
          if (tried_peers.count(peer.id))
            // Already tried, not a possible candidate
            continue;
 
          if (next_needed_pruning_stripe == 0 || peer.pruning_seed == 0)
            filtered.push_back(peer);
          else if (next_needed_pruning_stripe == tools::get_pruning_stripe(peer.pruning_seed))
            filtered.insert(filtered.begin(), peer);
          // else wrong stripe, skip
        }
 
        if (!filtered.empty())
          break;
      } // inner try loop
 
      if (filtered.empty())
      {
        MINFO("No available peer in " << (use_white_list ? "white" : "gray") << " list filtered by " << next_needed_pruning_stripe);
        return false;
      }
 
      size_t random_index;
      if (use_white_list)
      {
        // If using the white list, we first pick in the set of peers we've already been using earlier;
        // that "fixed probability" heavily favors the peers most recently seen in the candidate list
        random_index = get_random_index_with_fixed_probability(filtered.size() - 1);
 
        CRITICAL_REGION_LOCAL(m_used_stripe_peers_mutex);
        if (next_needed_pruning_stripe > 0 && next_needed_pruning_stripe <= (1ul << CRYPTONOTE_PRUNING_LOG_STRIPES) && !m_used_stripe_peers[next_needed_pruning_stripe-1].empty())
        {
          const epee::net_utils::network_address na = m_used_stripe_peers[next_needed_pruning_stripe-1].front();
          m_used_stripe_peers[next_needed_pruning_stripe-1].pop_front();
          for (size_t i = 0; i < filtered.size(); ++i)
          {
            const peerlist_entry &peer = filtered.at(i);
            if (peer.adr == na)
            {
              MDEBUG("Reusing stripe " << next_needed_pruning_stripe << " peer " << peer.adr.str());
              random_index = i;
              break;
            }
          }
        }
      }
      else
        random_index = crypto::rand_idx(filtered.size());
      CHECK_AND_ASSERT_MES(random_index < filtered.size(), false, "random_index < filtered.size() failed!!");
 
      // We have our final candidate for this pass of the outer try loop
      const peerlist_entry &candidate = filtered.at(random_index);
 
      if (tried_peers.count(candidate.id))
        // Already tried, don't try that one again
        continue;
      tried_peers.insert(candidate.id);
 
      _note("Considering connecting (out) to " << (use_white_list ? "white" : "gray") << " list peer: " <<
          peerid_to_string(candidate.id) << " " << candidate.adr.str() << ", pruning seed " << epee::string_tools::to_string_hex(candidate.pruning_seed) <<
          " (stripe " << next_needed_pruning_stripe << " needed), in loop pass " << outer_loop_count);
 
      if (zone.m_our_address == candidate.adr)
        // It's ourselves, obviously don't take that
        continue;
 
      if (is_peer_used(candidate)) {
        _note("Peer is used");
        continue;
      }
 
      if (!is_remote_host_allowed(candidate.adr)) {
        _note("Not allowed");
        continue;
      }
 
      if (is_addr_recently_failed(candidate.adr)) {
         _note("Recently failed");
        continue;
      }
 
      MDEBUG("Selected peer: " << peerid_to_string(candidate.id) << " " << candidate.adr.str()
      << ", pruning seed " << epee::string_tools::to_string_hex(candidate.pruning_seed) << " "
      << "[peer_list=" << (use_white_list ? white : gray)
      << "] last_seen: " << (candidate.last_seen ? epee::misc_utils::get_time_interval_string(time(NULL) - candidate.last_seen) : "never"));
 
      const time_t begin_connect = time(NULL);
      if (!try_to_connect_and_handshake_with_new_peer(candidate.adr, false, candidate.last_seen, use_white_list ? white : gray)) {
        time_t fail_connect = time(NULL);
        _note("Handshake failed after " << epee::misc_utils::get_time_interval_string(fail_connect - begin_connect));
        continue;
      }
 
      return true;
    } // outer try loop
 
    return false;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::connect_to_seed(epee::net_utils::zone zone)
  {
      network_zone& server = m_network_zones.at(zone);
      boost::upgrade_lock<boost::shared_mutex> seed_nodes_upgrade_lock(server.m_seed_nodes_lock);
 
      if (!server.m_seed_nodes_initialized)
      {
        const std::uint16_t default_port = cryptonote::get_config(m_nettype).P2P_DEFAULT_PORT;
        boost::upgrade_to_unique_lock<boost::shared_mutex> seed_nodes_lock(seed_nodes_upgrade_lock);
        server.m_seed_nodes_initialized = true;
        for (const auto& full_addr : get_seed_nodes(zone))
        {
          // seeds should have hostname converted to IP already
          MDEBUG("Seed node: " << full_addr);
          server.m_seed_nodes.push_back(MONERO_UNWRAP(net::get_network_address(full_addr, default_port)));
        }
        MDEBUG("Number of seed nodes: " << server.m_seed_nodes.size());
      }
 
      if (server.m_seed_nodes.empty() || m_offline || !m_exclusive_peers.empty())
        return true;
 
      size_t try_count = 0;
      bool is_connected_to_at_least_one_seed_node = false;
      size_t current_index = crypto::rand_idx(server.m_seed_nodes.size());
      while(true)
      {
        if(server.m_net_server.is_stop_signal_sent())
          return false;
 
        peerlist_entry pe_seed{};
        pe_seed.adr = server.m_seed_nodes[current_index];
        if (is_peer_used(pe_seed))
          is_connected_to_at_least_one_seed_node = true;
        else if (try_to_connect_and_handshake_with_new_peer(server.m_seed_nodes[current_index], true))
          break;
        if(++try_count > server.m_seed_nodes.size())
        {
          // only IP zone has fallback (to direct IP) seeds
          if (zone == epee::net_utils::zone::public_ && !m_fallback_seed_nodes_added.test_and_set())
          {
            MWARNING("Failed to connect to any of seed peers, trying fallback seeds");
            current_index = server.m_seed_nodes.size() - 1;
            {
              boost::upgrade_to_unique_lock<boost::shared_mutex> seed_nodes_lock(seed_nodes_upgrade_lock);
 
              for (const auto &peer: get_ip_seed_nodes())
              {
                MDEBUG("Fallback seed node: " << peer);
                append_net_address(server.m_seed_nodes, peer, cryptonote::get_config(m_nettype).P2P_DEFAULT_PORT);
              }
            }
            if (current_index == server.m_seed_nodes.size() - 1)
            {
              MWARNING("No fallback seeds, continuing without seeds");
              break;
            }
            // continue for another few cycles
          }
          else
          {
            if (!is_connected_to_at_least_one_seed_node)
              MWARNING("Failed to connect to any of seed peers, continuing without seeds");
            break;
          }
        }
        if(++current_index >= server.m_seed_nodes.size())
          current_index = 0;
      }
      return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::connections_maker()
  {
    using zone_type = epee::net_utils::zone;
 
    if (m_offline) return true;
    if (!connect_to_peerlist(m_exclusive_peers)) return false;
 
    if (!m_exclusive_peers.empty()) return true;
 
    bool one_succeeded = false;
    for(auto& zone : m_network_zones)
    {
      size_t start_conn_count = get_outgoing_connections_count(zone.second);
      if(!zone.second.m_peerlist.get_white_peers_count() && !connect_to_seed(zone.first))
      {
        continue;
      }
 
      if (zone.first == zone_type::public_ && !connect_to_peerlist(m_priority_peers)) continue;
 
      size_t base_expected_white_connections = (zone.second.m_config.m_net_config.max_out_connection_count*P2P_DEFAULT_WHITELIST_CONNECTIONS_PERCENT)/100;
 
      // carefully avoid `continue` in nested loop
      
      size_t conn_count = get_outgoing_connections_count(zone.second);
      while(conn_count < zone.second.m_config.m_net_config.max_out_connection_count)
      {
        const size_t expected_white_connections = m_payload_handler.get_next_needed_pruning_stripe().second ? zone.second.m_config.m_net_config.max_out_connection_count : base_expected_white_connections;
        if(conn_count < expected_white_connections)
        {
          //start from anchor list
          while (get_outgoing_connections_count(zone.second) < P2P_DEFAULT_ANCHOR_CONNECTIONS_COUNT
            && make_expected_connections_count(zone.second, anchor, P2P_DEFAULT_ANCHOR_CONNECTIONS_COUNT));
          //then do white list
          while (get_outgoing_connections_count(zone.second) < expected_white_connections
            && make_expected_connections_count(zone.second, white, expected_white_connections));
          //then do grey list
          while (get_outgoing_connections_count(zone.second) < zone.second.m_config.m_net_config.max_out_connection_count
            && make_expected_connections_count(zone.second, gray, zone.second.m_config.m_net_config.max_out_connection_count));
        }else
        {
          //start from grey list
          while (get_outgoing_connections_count(zone.second) < zone.second.m_config.m_net_config.max_out_connection_count
            && make_expected_connections_count(zone.second, gray, zone.second.m_config.m_net_config.max_out_connection_count));
          //and then do white list
          while (get_outgoing_connections_count(zone.second) < zone.second.m_config.m_net_config.max_out_connection_count
            && make_expected_connections_count(zone.second, white, zone.second.m_config.m_net_config.max_out_connection_count));
        }
        if(zone.second.m_net_server.is_stop_signal_sent())
          return false;
        size_t new_conn_count = get_outgoing_connections_count(zone.second);
        if (new_conn_count <= conn_count)
        {
          // we did not make any connection, sleep a bit to avoid a busy loop in case we don't have
          // any peers to try, then break so we will try seeds to get more peers
          boost::this_thread::sleep_for(boost::chrono::seconds(1));
          break;
        }
        conn_count = new_conn_count;
      }
 
      if (start_conn_count == get_outgoing_connections_count(zone.second) && start_conn_count < zone.second.m_config.m_net_config.max_out_connection_count)
      {
        MINFO("Failed to connect to any, trying seeds");
        if (!connect_to_seed(zone.first))
          continue;
      }
      one_succeeded = true;
    }
 
    return one_succeeded;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::make_expected_connections_count(network_zone& zone, PeerType peer_type, size_t expected_connections)
  {
    if (m_offline)
      return false;
 
    std::vector<anchor_peerlist_entry> apl;
 
    if (peer_type == anchor) {
      zone.m_peerlist.get_and_empty_anchor_peerlist(apl);
    }
 
    size_t conn_count = get_outgoing_connections_count(zone);
    //add new connections from white peers
    if(conn_count < expected_connections)
    {
      if(zone.m_net_server.is_stop_signal_sent())
        return false;
 
      MDEBUG("Making expected connection, type " << peer_type << ", " << conn_count << "/" << expected_connections << " connections");
 
      if (peer_type == anchor && !make_new_connection_from_anchor_peerlist(apl)) {
        return false;
      }
 
      if (peer_type == white && !make_new_connection_from_peerlist(zone, true)) {
        return false;
      }
 
      if (peer_type == gray && !make_new_connection_from_peerlist(zone, false)) {
        return false;
      }
    }
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_public_outgoing_connections_count()
  {
    auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone == m_network_zones.end())
      return 0;
    return get_outgoing_connections_count(public_zone->second);
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_incoming_connections_count(network_zone& zone)
  {
    size_t count = 0;
    zone.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
    {
      if(cntxt.m_is_income)
        ++count;
      return true;
    });
    return count;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_outgoing_connections_count(network_zone& zone)
  {
    size_t count = 0;
    zone.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
    {
      if(!cntxt.m_is_income && !cntxt.is_ping)
        ++count;
      return true;
    });
 
    // Refresh the counter in the zone. The thread that the 'run' method sets up for the
    // job to update the counters runs only once every second. If we only rely on that,
    // 'try_to_connect_and_handshake_with_new_peer' called in 'make_new_connection_from_peerlist'
    // will often fail right away because it thinks there are still enough connections, with
    // perfectly good new peer candidates totally wasted, and a bad success rate choosing peers
    zone.m_current_number_of_out_peers = count;
 
    return count;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_outgoing_connections_count()
  {
    size_t count = 0;
    for(auto& zone : m_network_zones)
      count += get_outgoing_connections_count(zone.second);
    return count;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_incoming_connections_count()
  {
    size_t count = 0;
    for (auto& zone : m_network_zones)
    {
      zone.second.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
      {
        if(cntxt.m_is_income)
          ++count;
        return true;
      });
    }
    return count;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_public_white_peers_count()
  {
    auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone == m_network_zones.end())
      return 0;
    return public_zone->second.m_peerlist.get_white_peers_count();
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  size_t node_server<t_payload_net_handler>::get_public_gray_peers_count()
  {
    auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone == m_network_zones.end())
      return 0;
    return public_zone->second.m_peerlist.get_gray_peers_count();
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::get_public_peerlist(std::vector<peerlist_entry>& gray, std::vector<peerlist_entry>& white)
  {
    auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone != m_network_zones.end())
      public_zone->second.m_peerlist.get_peerlist(gray, white);
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::get_peerlist(std::vector<peerlist_entry>& gray, std::vector<peerlist_entry>& white)
  {
    for (auto &zone: m_network_zones)
    {
      zone.second.m_peerlist.get_peerlist(gray, white); // appends
    }
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::idle_worker()
  {
    m_peer_handshake_idle_maker_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::peer_sync_idle_maker, this));
    m_connections_maker_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::connections_maker, this));
    m_gray_peerlist_housekeeping_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::gray_peerlist_housekeeping, this));
    m_peerlist_store_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::store_config, this));
    m_incoming_connections_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::check_incoming_connections, this));
    m_dns_blocklist_interval.do_call(boost::bind(&node_server<t_payload_net_handler>::update_dns_blocklist, this));
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::update_dns_blocklist()
  {
    if (!m_enable_dns_blocklist)
      return true;
    if (m_nettype != cryptonote::MAINNET)
      return true;
 
    static const std::vector<std::string> dns_urls = {
      "blocklist.moneropulse.se"
    , "blocklist.moneropulse.org"
    , "blocklist.moneropulse.net"
    , "blocklist.moneropulse.co"
    , "blocklist.moneropulse.fr"
    , "blocklist.moneropulse.de"
    , "blocklist.moneropulse.ch"
    };
 
    std::vector<std::string> records;
    if (!tools::dns_utils::load_txt_records_from_dns(records, dns_urls))
      return true;
 
    unsigned good = 0, bad = 0;
    for (const auto& record : records)
    {
      std::vector<std::string> ips;
      boost::split(ips, record, boost::is_any_of(";"));
      for (const auto &ip: ips)
      {
        if (ip.empty())
          continue;
        auto subnet = net::get_ipv4_subnet_address(ip);
        if (subnet)
        {
          block_subnet(*subnet, DNS_BLOCKLIST_LIFETIME);
          ++good;
          continue;
        }
        const expect<epee::net_utils::network_address> parsed_addr = net::get_network_address(ip, 0);
        if (parsed_addr)
        {
          block_host(*parsed_addr, DNS_BLOCKLIST_LIFETIME, true);
          ++good;
          continue;
        }
        MWARNING("Invalid IP address or subnet from DNS blocklist: " << ip << " - " << parsed_addr.error());
        ++bad;
      }
    }
    if (good > 0)
      MINFO(good << " addresses added to the blocklist");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::check_incoming_connections()
  {
    if (m_offline)
      return true;
 
    const auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone != m_network_zones.end() && get_incoming_connections_count(public_zone->second) == 0)
    {
      if (m_hide_my_port || public_zone->second.m_config.m_net_config.max_in_connection_count == 0)
      {
        MGINFO("Incoming connections disabled, enable them for full connectivity");
      }
      else
      {
        const el::Level level = el::Level::Warning;
        MCLOG_RED(level, "global", "No incoming connections - check firewalls/routers allow port " << get_this_peer_port());
      }
    }
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::peer_sync_idle_maker()
  {
    MDEBUG("STARTED PEERLIST IDLE HANDSHAKE");
    typedef std::list<std::pair<epee::net_utils::connection_context_base, peerid_type> > local_connects_type;
    local_connects_type cncts;
    for(auto& zone : m_network_zones)
    {
      zone.second.m_net_server.get_config_object().foreach_connection([&](p2p_connection_context& cntxt)
      {
        if(cntxt.peer_id && !cntxt.m_in_timedsync)
        {
          cntxt.m_in_timedsync = true;
          cncts.push_back(local_connects_type::value_type(cntxt, cntxt.peer_id));//do idle sync only with handshaked connections
        }
        return true;
      });
    }
 
    std::for_each(cncts.begin(), cncts.end(), [&](const typename local_connects_type::value_type& vl){do_peer_timed_sync(vl.first, vl.second);});
 
    MDEBUG("FINISHED PEERLIST IDLE HANDSHAKE");
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::sanitize_peerlist(std::vector<peerlist_entry>& local_peerlist)
  {
    for (size_t i = 0; i < local_peerlist.size(); ++i)
    {
      bool ignore = false;
      peerlist_entry &be = local_peerlist[i];
      epee::net_utils::network_address &na = be.adr;
      if (na.is_loopback() || na.is_local())
      {
        ignore = true;
      }
      else if (be.adr.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id())
      {
        const epee::net_utils::ipv4_network_address &ipv4 = na.as<const epee::net_utils::ipv4_network_address>();
        if (ipv4.ip() == 0)
          ignore = true;
        else if (ipv4.port() == be.rpc_port)
          ignore = true;
      }
      if (be.pruning_seed && (be.pruning_seed < tools::make_pruning_seed(1, CRYPTONOTE_PRUNING_LOG_STRIPES) || be.pruning_seed > tools::make_pruning_seed(1ul << CRYPTONOTE_PRUNING_LOG_STRIPES, CRYPTONOTE_PRUNING_LOG_STRIPES)))
        ignore = true;
      if (ignore)
      {
        MDEBUG("Ignoring " << be.adr.str());
        std::swap(local_peerlist[i], local_peerlist[local_peerlist.size() - 1]);
        local_peerlist.resize(local_peerlist.size() - 1);
        --i;
        continue;
      }
      local_peerlist[i].last_seen = 0;
    }
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::handle_remote_peerlist(const std::vector<peerlist_entry>& peerlist, const epee::net_utils::connection_context_base& context)
  {
    if (peerlist.size() > P2P_MAX_PEERS_IN_HANDSHAKE)
    {
      MWARNING(context << "peer sent " << peerlist.size() << " peers, considered spamming");
      return false;
    }
    std::vector<peerlist_entry> peerlist_ = peerlist;
    if(!sanitize_peerlist(peerlist_))
      return false;
 
    const epee::net_utils::zone zone = context.m_remote_address.get_zone();
    for(const auto& peer : peerlist_)
    {
      if(peer.adr.get_zone() != zone)
      {
        MWARNING(context << " sent peerlist from another zone, dropping");
        return false;
      }
    }
 
    LOG_DEBUG_CC(context, "REMOTE PEERLIST: remote peerlist size=" << peerlist_.size());
    LOG_TRACE_CC(context, "REMOTE PEERLIST: " << ENDL << print_peerlist_to_string(peerlist_));
    CRITICAL_REGION_LOCAL(m_blocked_hosts_lock);
    return m_network_zones.at(context.m_remote_address.get_zone()).m_peerlist.merge_peerlist(peerlist_, [this](const peerlist_entry &pe) {
      return !is_addr_recently_failed(pe.adr) && is_remote_host_allowed(pe.adr);
    });
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::get_local_node_data(basic_node_data& node_data, const network_zone& zone)
  {
    node_data.peer_id = zone.m_config.m_peer_id;
    if(!m_hide_my_port && zone.m_can_pingback)
      node_data.my_port = m_external_port ? m_external_port : m_listening_port;
    else
      node_data.my_port = 0;
    node_data.rpc_port = zone.m_can_pingback ? m_rpc_port : 0;
    node_data.rpc_credits_per_hash = zone.m_can_pingback ? m_rpc_credits_per_hash : 0;
    node_data.network_id = m_network_id;
    node_data.support_flags = zone.m_config.m_support_flags;
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  int node_server<t_payload_net_handler>::handle_get_support_flags(int command, COMMAND_REQUEST_SUPPORT_FLAGS::request& arg, COMMAND_REQUEST_SUPPORT_FLAGS::response& rsp, p2p_connection_context& context)
  {
    rsp.support_flags = m_network_zones.at(context.m_remote_address.get_zone()).m_config.m_support_flags;
    return 1;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::request_callback(const epee::net_utils::connection_context_base& context)
  {
    m_network_zones.at(context.m_remote_address.get_zone()).m_net_server.get_config_object().request_callback(context.m_connection_id);
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::relay_notify_to_list(int command, epee::levin::message_writer data_buff, std::vector<std::pair<epee::net_utils::zone, boost::uuids::uuid>> connections)
  {
    epee::byte_slice message = data_buff.finalize_notify(command);
    std::sort(connections.begin(), connections.end());
    auto zone = m_network_zones.begin();
    for(const auto& c_id: connections)
    {
      for (;;)
      {
        if (zone == m_network_zones.end())
        {
           MWARNING("Unable to relay all messages, " << epee::net_utils::zone_to_string(c_id.first) << " not available");
           return false;
        }
        if (c_id.first <= zone->first)
          break;
 
        ++zone;
      }
      if (zone->first == c_id.first)
        zone->second.m_net_server.get_config_object().send(message.clone(), c_id.second);
    }
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  epee::net_utils::zone node_server<t_payload_net_handler>::send_txs(std::vector<cryptonote::blobdata> txs, const epee::net_utils::zone origin, const boost::uuids::uuid& source, const cryptonote::relay_method tx_relay)
  {
    namespace enet = epee::net_utils;
 
    const auto send = [&txs, &source, tx_relay] (std::pair<const enet::zone, network_zone>& network)
    {
      if (network.second.m_notifier.send_txs(std::move(txs), source, tx_relay))
        return network.first;
      return enet::zone::invalid;
    };
 
    if (m_network_zones.empty())
      return enet::zone::invalid;
 
    if (origin != enet::zone::invalid)
      return send(*m_network_zones.begin()); // send all txs received via p2p over public network
 
    if (m_network_zones.size() <= 2)
      return send(*m_network_zones.rbegin()); // see static asserts below; sends over anonymity network iff enabled
 
    /* These checks are to ensure that i2p is highest priority if multiple
       zones are selected. Make sure to update logic if the values cannot be
       in the same relative order. `m_network_zones` must be sorted map too. */
    static_assert(std::is_same<std::underlying_type<enet::zone>::type, std::uint8_t>{}, "expected uint8_t zone");
    static_assert(unsigned(enet::zone::invalid) == 0, "invalid expected to be 0");
    static_assert(unsigned(enet::zone::public_) == 1, "public_ expected to be 1");
    static_assert(unsigned(enet::zone::i2p) == 2, "i2p expected to be 2");
    static_assert(unsigned(enet::zone::tor) == 3, "tor expected to be 3");
 
    // check for anonymity networks with noise and connections
    for (auto network = ++m_network_zones.begin(); network != m_network_zones.end(); ++network)
    {
      if (enet::zone::tor < network->first)
        break; // unknown network
 
      const auto status = network->second.m_notifier.get_status();
      if (status.has_noise && status.connections_filled)
        return send(*network);
    }
 
    // use the anonymity network with outbound support
    for (auto network = ++m_network_zones.begin(); network != m_network_zones.end(); ++network)
    {
      if (enet::zone::tor < network->first)
        break; // unknown network
 
      const auto status = network->second.m_notifier.get_status();
      if (network->second.m_connect && status.has_outgoing)
        return send(*network);
    }
 
    MWARNING("Unable to send " << txs.size() << " transaction(s): anonymity networks had no outgoing connections");
    return enet::zone::invalid;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::callback(p2p_connection_context& context)
  {
    m_payload_handler.on_callback(context);
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::invoke_notify_to_peer(const int command, epee::levin::message_writer message, const epee::net_utils::connection_context_base& context)
  {
    if(is_filtered_command(context.m_remote_address, command))
      return false;
 
    network_zone& zone = m_network_zones.at(context.m_remote_address.get_zone());
    int res = zone.m_net_server.get_config_object().send(message.finalize_notify(command), context.m_connection_id);
    return res > 0;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::drop_connection(const epee::net_utils::connection_context_base& context)
  {
    m_network_zones.at(context.m_remote_address.get_zone()).m_net_server.get_config_object().close(context.m_connection_id, false);
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler> template<class t_callback>
  bool node_server<t_payload_net_handler>::try_ping(basic_node_data& node_data, p2p_connection_context& context, const t_callback &cb)
  {
    if(!node_data.my_port)
      return false;
 
    bool address_ok = (context.m_remote_address.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id() || context.m_remote_address.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id());
    CHECK_AND_ASSERT_MES(address_ok, false,
        "Only IPv4 or IPv6 addresses are supported here");
 
    const epee::net_utils::network_address na = context.m_remote_address;
    std::string ip;
    uint32_t ipv4_addr = 0;
    boost::asio::ip::address_v6 ipv6_addr;
    bool is_ipv4;
    if (na.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id())
    {
      ipv4_addr = na.as<const epee::net_utils::ipv4_network_address>().ip();
      ip = epee::string_tools::get_ip_string_from_int32(ipv4_addr);
      is_ipv4 = true;
    }
    else
    {
      ipv6_addr = na.as<const epee::net_utils::ipv6_network_address>().ip();
      ip = ipv6_addr.to_string();
      is_ipv4 = false;
    }
    network_zone& zone = m_network_zones.at(na.get_zone());
 
    if(!zone.m_peerlist.is_host_allowed(context.m_remote_address))
      return false;
 
    std::string port = epee::string_tools::num_to_string_fast(node_data.my_port);
 
    epee::net_utils::network_address address;
    if (is_ipv4)
    {
      address = epee::net_utils::network_address{epee::net_utils::ipv4_network_address(ipv4_addr, node_data.my_port)};
    }
    else
    {
      address = epee::net_utils::network_address{epee::net_utils::ipv6_network_address(ipv6_addr, node_data.my_port)};
    }
    peerid_type pr = node_data.peer_id;
    bool r = zone.m_net_server.connect_async(ip, port, zone.m_config.m_net_config.ping_connection_timeout, [cb, /*context,*/ address, pr, this](
      const typename net_server::t_connection_context& ping_context,
      const boost::system::error_code& ec)->bool
    {
      if(ec)
      {
        LOG_WARNING_CC(ping_context, "back ping connect failed to " << address.str());
        return false;
      }
      COMMAND_PING::request req;
      COMMAND_PING::response rsp;
      //vc2010 workaround
      /*std::string ip_ = ip;
      std::string port_=port;
      peerid_type pr_ = pr;
      auto cb_ = cb;*/
 
      // GCC 5.1.0 gives error with second use of uint64_t (peerid_type) variable.
      peerid_type pr_ = pr;
 
      network_zone& zone = m_network_zones.at(address.get_zone());
 
      bool inv_call_res = epee::net_utils::async_invoke_remote_command2<COMMAND_PING::response>(ping_context, COMMAND_PING::ID, req, zone.m_net_server.get_config_object(),
        [=](int code, const COMMAND_PING::response& rsp, p2p_connection_context& context)
      {
        if(code <= 0)
        {
          LOG_WARNING_CC(ping_context, "Failed to invoke COMMAND_PING to " << address.str() << "(" << code <<  ", " << epee::levin::get_err_descr(code) << ")");
          return;
        }
 
        network_zone& zone = m_network_zones.at(address.get_zone());
        if(rsp.status != PING_OK_RESPONSE_STATUS_TEXT || pr != rsp.peer_id)
        {
          LOG_WARNING_CC(ping_context, "back ping invoke wrong response \"" << rsp.status << "\" from" << address.str() << ", hsh_peer_id=" << pr_ << ", rsp.peer_id=" << peerid_to_string(rsp.peer_id));
          zone.m_net_server.get_config_object().close(ping_context.m_connection_id, false);
          return;
        }
        zone.m_net_server.get_config_object().close(ping_context.m_connection_id, false);
        cb();
      });
 
      if(!inv_call_res)
      {
        LOG_WARNING_CC(ping_context, "back ping invoke failed to " << address.str());
        zone.m_net_server.get_config_object().close(ping_context.m_connection_id, false);
        return false;
      }
      return true;
    }, "0.0.0.0", m_ssl_support, p2p_connection_context{true /* is_ping */});
    if(!r)
    {
      LOG_WARNING_CC(context, "Failed to call connect_async, network error.");
    }
    return r;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::try_get_support_flags(const p2p_connection_context& context, std::function<void(p2p_connection_context&, const uint32_t&)> f)
  {
    if(context.m_remote_address.get_zone() != epee::net_utils::zone::public_)
      return false;
 
    COMMAND_REQUEST_SUPPORT_FLAGS::request support_flags_request;
    bool r = epee::net_utils::async_invoke_remote_command2<typename COMMAND_REQUEST_SUPPORT_FLAGS::response>
    (
      context,
      COMMAND_REQUEST_SUPPORT_FLAGS::ID, 
      support_flags_request, 
      m_network_zones.at(epee::net_utils::zone::public_).m_net_server.get_config_object(),
      [=](int code, const typename COMMAND_REQUEST_SUPPORT_FLAGS::response& rsp, p2p_connection_context& context_)
      {  
        if(code < 0)
        {
          LOG_WARNING_CC(context_, "COMMAND_REQUEST_SUPPORT_FLAGS invoke failed. (" << code <<  ", " << epee::levin::get_err_descr(code) << ")");
          return;
        }
        
        f(context_, rsp.support_flags);
      },
      P2P_DEFAULT_HANDSHAKE_INVOKE_TIMEOUT
    );
 
    return r;
  }  
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  int node_server<t_payload_net_handler>::handle_timed_sync(int command, typename COMMAND_TIMED_SYNC::request& arg, typename COMMAND_TIMED_SYNC::response& rsp, p2p_connection_context& context)
  {
    if(!m_payload_handler.process_payload_sync_data(arg.payload_data, context, false))
    {
      LOG_WARNING_CC(context, "Failed to process_payload_sync_data(), dropping connection");
      drop_connection(context);
      return 1;
    }
 
    //fill response
    const epee::net_utils::zone zone_type = context.m_remote_address.get_zone();
    network_zone& zone = m_network_zones.at(zone_type);
 
    //will add self to peerlist if in same zone as outgoing later in this function
    const bool outgoing_to_same_zone = !context.m_is_income && zone.m_our_address.get_zone() == zone_type;
    const uint32_t max_peerlist_size = P2P_DEFAULT_PEERS_IN_HANDSHAKE - (outgoing_to_same_zone ? 1 : 0);
 
    std::vector<peerlist_entry> local_peerlist_new;
    zone.m_peerlist.get_peerlist_head(local_peerlist_new, true, max_peerlist_size);
 
    /* Tor/I2P nodes receiving connections via forwarding (from tor/i2p daemon)
    do not know the address of the connecting peer. This is relayed to them,
    iff the node has setup an inbound hidden service.
 
    \note Insert into `local_peerlist_new` so that it is only sent once like
      the other peers. */
    if(outgoing_to_same_zone)
    {
      local_peerlist_new.insert(
        local_peerlist_new.begin() + crypto::rand_range(std::size_t(0), local_peerlist_new.size()),
        peerlist_entry{zone.m_our_address, zone.m_config.m_peer_id, 0}
      );
    }
 
    //only include out peers we did not already send
    rsp.local_peerlist_new.reserve(local_peerlist_new.size());
    for (auto &pe: local_peerlist_new)
    {
      if (!context.sent_addresses.insert(pe.adr).second)
        continue;
      rsp.local_peerlist_new.push_back(std::move(pe));
    }
    m_payload_handler.get_payload_sync_data(rsp.payload_data);
 
    LOG_DEBUG_CC(context, "COMMAND_TIMED_SYNC");
    return 1;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  int node_server<t_payload_net_handler>::handle_handshake(int command, typename COMMAND_HANDSHAKE::request& arg, typename COMMAND_HANDSHAKE::response& rsp, p2p_connection_context& context)
  {
    if(arg.node_data.network_id != m_network_id)
    {
 
      LOG_INFO_CC(context, "WRONG NETWORK AGENT CONNECTED! id=" << arg.node_data.network_id);
      drop_connection(context);
      add_host_fail(context.m_remote_address);
      return 1;
    }
 
    if(!context.m_is_income)
    {
      LOG_WARNING_CC(context, "COMMAND_HANDSHAKE came not from incoming connection");
      drop_connection(context);
      add_host_fail(context.m_remote_address);
      return 1;
    }
 
    if(context.peer_id)
    {
      LOG_WARNING_CC(context, "COMMAND_HANDSHAKE came, but seems that connection already have associated peer_id (double COMMAND_HANDSHAKE?)");
      drop_connection(context);
      return 1;
    }
 
    const auto azone = context.m_remote_address.get_zone();
    network_zone& zone = m_network_zones.at(azone);
 
    // test only the remote end's zone, otherwise an attacker could connect to you on clearnet
    // and pass in a tor connection's peer id, and deduce the two are the same if you reject it
    if(azone == epee::net_utils::zone::public_ && arg.node_data.peer_id == zone.m_config.m_peer_id)
    {
      LOG_DEBUG_CC(context, "Connection to self detected, dropping connection");
      drop_connection(context);
      return 1;
    }
 
    if(!m_payload_handler.process_payload_sync_data(arg.payload_data, context, true))
    {
      LOG_WARNING_CC(context, "COMMAND_HANDSHAKE came, but process_payload_sync_data returned false, dropping connection.");
      drop_connection(context);
      return 1;
    }
 
    zone.m_notifier.on_handshake_complete(context.m_connection_id, context.m_is_income);
 
    //associate peer_id with this connection
    context.peer_id = arg.node_data.peer_id;
    context.m_in_timedsync = false;
    context.m_rpc_port = arg.node_data.rpc_port;
    context.m_rpc_credits_per_hash = arg.node_data.rpc_credits_per_hash;
    context.support_flags = arg.node_data.support_flags;
 
    if(arg.node_data.my_port && zone.m_can_pingback)
    {
      peerid_type peer_id_l = arg.node_data.peer_id;
      uint32_t port_l = arg.node_data.my_port;
      //try ping to be sure that we can add this peer to peer_list
      try_ping(arg.node_data, context, [peer_id_l, port_l, context, this]()
      {
        CHECK_AND_ASSERT_MES((context.m_remote_address.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id() || context.m_remote_address.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id()), void(),
            "Only IPv4 or IPv6 addresses are supported here");
        //called only(!) if success pinged, update local peerlist
        peerlist_entry pe;
        const epee::net_utils::network_address na = context.m_remote_address;
        if (context.m_remote_address.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id())
        {
          pe.adr = epee::net_utils::ipv4_network_address(na.as<epee::net_utils::ipv4_network_address>().ip(), port_l);
        }
        else
        {
          pe.adr = epee::net_utils::ipv6_network_address(na.as<epee::net_utils::ipv6_network_address>().ip(), port_l);
        }
        time_t last_seen;
        time(&last_seen);
        pe.last_seen = static_cast<int64_t>(last_seen);
        pe.id = peer_id_l;
        pe.pruning_seed = context.m_pruning_seed;
        pe.rpc_port = context.m_rpc_port;
        pe.rpc_credits_per_hash = context.m_rpc_credits_per_hash;
        this->m_network_zones.at(context.m_remote_address.get_zone()).m_peerlist.append_with_peer_white(pe);
        LOG_DEBUG_CC(context, "PING SUCCESS " << context.m_remote_address.host_str() << ":" << port_l);
      });
    }
    
    if (context.support_flags == 0)
      try_get_support_flags(context, [](p2p_connection_context& flags_context, const uint32_t& support_flags) 
      {
        flags_context.support_flags = support_flags;
      });
 
    //fill response
    zone.m_peerlist.get_peerlist_head(rsp.local_peerlist_new, true);
    for (const auto &e: rsp.local_peerlist_new)
      context.sent_addresses.insert(e.adr);
    get_local_node_data(rsp.node_data, zone);
    m_payload_handler.get_payload_sync_data(rsp.payload_data);
    LOG_DEBUG_CC(context, "COMMAND_HANDSHAKE");
    return 1;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  int node_server<t_payload_net_handler>::handle_ping(int command, COMMAND_PING::request& arg, COMMAND_PING::response& rsp, p2p_connection_context& context)
  {
    LOG_DEBUG_CC(context, "COMMAND_PING");
    rsp.status = PING_OK_RESPONSE_STATUS_TEXT;
    rsp.peer_id = m_network_zones.at(context.m_remote_address.get_zone()).m_config.m_peer_id;
    return 1;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::log_peerlist()
  {
    std::vector<peerlist_entry> pl_white;
    std::vector<peerlist_entry> pl_gray;
    for (auto& zone : m_network_zones)
      zone.second.m_peerlist.get_peerlist(pl_gray, pl_white);
    MINFO(ENDL << "Peerlist white:" << ENDL << print_peerlist_to_string(pl_white) << ENDL << "Peerlist gray:" << ENDL << print_peerlist_to_string(pl_gray) );
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::log_connections()
  {
    MINFO("Connections: \r\n" << print_connections_container() );
    return true;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  std::string node_server<t_payload_net_handler>::print_connections_container()
  {
 
    std::stringstream ss;
    for (auto& zone : m_network_zones)
    {
      zone.second.m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
      {
        ss << cntxt.m_remote_address.str()
          << " \t\tpeer_id " << peerid_to_string(cntxt.peer_id)
          << " \t\tconn_id " << cntxt.m_connection_id << (cntxt.m_is_income ? " INC":" OUT")
          << std::endl;
        return true;
      });
    }
    std::string s = ss.str();
    return s;
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::on_connection_new(p2p_connection_context& context)
  {
    MINFO("["<< epee::net_utils::print_connection_context(context) << "] NEW CONNECTION");
  }
  //-----------------------------------------------------------------------------------
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::on_connection_close(p2p_connection_context& context)
  {
    network_zone& zone = m_network_zones.at(context.m_remote_address.get_zone());
    if (!zone.m_net_server.is_stop_signal_sent() && !context.m_is_income) {
      epee::net_utils::network_address na = AUTO_VAL_INIT(na);
      na = context.m_remote_address;
 
      zone.m_peerlist.remove_from_peer_anchor(na);
    }
 
    if (!zone.m_net_server.is_stop_signal_sent()) {
      zone.m_notifier.on_connection_close(context.m_connection_id);
    }
    m_payload_handler.on_connection_close(context);
 
    MINFO("["<< epee::net_utils::print_connection_context(context) << "] CLOSE CONNECTION");
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::is_priority_node(const epee::net_utils::network_address& na)
  {
    return (std::find(m_priority_peers.begin(), m_priority_peers.end(), na) != m_priority_peers.end()) || (std::find(m_exclusive_peers.begin(), m_exclusive_peers.end(), na) != m_exclusive_peers.end());
  }
 
  template<class t_payload_net_handler> template <class Container>
  bool node_server<t_payload_net_handler>::connect_to_peerlist(const Container& peers)
  {
    const network_zone& public_zone = m_network_zones.at(epee::net_utils::zone::public_);
    for(const epee::net_utils::network_address& na: peers)
    {
      if(public_zone.m_net_server.is_stop_signal_sent())
        return false;
 
      if(is_addr_connected(na))
        continue;
 
      try_to_connect_and_handshake_with_new_peer(na);
    }
 
    return true;
  }
 
  template<class t_payload_net_handler> template <class Container>
  bool node_server<t_payload_net_handler>::parse_peers_and_add_to_container(const boost::program_options::variables_map& vm, const command_line::arg_descriptor<std::vector<std::string> > & arg, Container& container)
  {
    std::vector<std::string> perrs = command_line::get_arg(vm, arg);
 
    for(const std::string& pr_str: perrs)
    {
      const uint16_t default_port = cryptonote::get_config(m_nettype).P2P_DEFAULT_PORT;
      expect<epee::net_utils::network_address> adr = net::get_network_address(pr_str, default_port);
      if (adr)
      {
        add_zone(adr->get_zone());
        container.push_back(std::move(*adr));
        continue;
      }
      std::vector<epee::net_utils::network_address> resolved_addrs;
      bool r = append_net_address(resolved_addrs, pr_str, default_port);
      CHECK_AND_ASSERT_MES(r, false, "Failed to parse or resolve address from string: " << pr_str);
      for (const epee::net_utils::network_address& addr : resolved_addrs)
      {
        container.push_back(addr);
      }
    }
 
    return true;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::set_max_out_peers(network_zone& zone, int64_t max)
  {
    if(max == -1) {
      zone.m_config.m_net_config.max_out_connection_count = P2P_DEFAULT_CONNECTIONS_COUNT;
      return true;
    }
    zone.m_config.m_net_config.max_out_connection_count = max;
    return true;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::set_max_in_peers(network_zone& zone, int64_t max)
  {
    zone.m_config.m_net_config.max_in_connection_count = max;
    return true;
  }
 
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::change_max_out_public_peers(size_t count)
  {
    auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone != m_network_zones.end())
    {
      const auto current = public_zone->second.m_net_server.get_config_object().get_out_connections_count();
      public_zone->second.m_config.m_net_config.max_out_connection_count = count;
      if(current > count)
        public_zone->second.m_net_server.get_config_object().del_out_connections(current - count);
      m_payload_handler.set_max_out_peers(epee::net_utils::zone::public_, count);
    }
  }
 
  template<class t_payload_net_handler>
  uint32_t node_server<t_payload_net_handler>::get_max_out_public_peers() const
  {
    const auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone == m_network_zones.end())
      return 0;
    return public_zone->second.m_config.m_net_config.max_out_connection_count;
  }
 
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::change_max_in_public_peers(size_t count)
  {
    auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone != m_network_zones.end())
    {
      const auto current = public_zone->second.m_net_server.get_config_object().get_in_connections_count();
      public_zone->second.m_config.m_net_config.max_in_connection_count = count;
      if(current > count)
        public_zone->second.m_net_server.get_config_object().del_in_connections(current - count);
    }
  }
 
  template<class t_payload_net_handler>
  uint32_t node_server<t_payload_net_handler>::get_max_in_public_peers() const
  {
    const auto public_zone = m_network_zones.find(epee::net_utils::zone::public_);
    if (public_zone == m_network_zones.end())
      return 0;
    return public_zone->second.m_config.m_net_config.max_in_connection_count;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::set_tos_flag(const boost::program_options::variables_map& vm, int flag)
  {
    if(flag==-1){
      return true;
    }
    epee::net_utils::connection<epee::levin::async_protocol_handler<p2p_connection_context> >::set_tos_flag(flag);
    _dbg1("Set ToS flag  " << flag);
    return true;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::set_rate_up_limit(const boost::program_options::variables_map& vm, int64_t limit)
  {
    this->islimitup=(limit != -1) && (limit != default_limit_up);
 
    if (limit==-1) {
      limit=default_limit_up;
    }
 
    epee::net_utils::connection<epee::levin::async_protocol_handler<p2p_connection_context> >::set_rate_up_limit( limit );
    MINFO("Set limit-up to " << limit << " kB/s");
    return true;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::set_rate_down_limit(const boost::program_options::variables_map& vm, int64_t limit)
  {
    this->islimitdown=(limit != -1) && (limit != default_limit_down);
    if(limit==-1) {
      limit=default_limit_down;
    }
    epee::net_utils::connection<epee::levin::async_protocol_handler<p2p_connection_context> >::set_rate_down_limit( limit );
    MINFO("Set limit-down to " << limit << " kB/s");
    return true;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::set_rate_limit(const boost::program_options::variables_map& vm, int64_t limit)
  {
    int64_t limit_up = 0;
    int64_t limit_down = 0;
 
    if(limit == -1)
    {
      limit_up = default_limit_up;
      limit_down = default_limit_down;
    }
    else
    {
      limit_up = limit;
      limit_down = limit;
    }
    if(!this->islimitup) {
      epee::net_utils::connection<epee::levin::async_protocol_handler<p2p_connection_context> >::set_rate_up_limit(limit_up);
      MINFO("Set limit-up to " << limit_up << " kB/s");
    }
    if(!this->islimitdown) {
      epee::net_utils::connection<epee::levin::async_protocol_handler<p2p_connection_context> >::set_rate_down_limit(limit_down);
      MINFO("Set limit-down to " << limit_down << " kB/s");
    }
 
    return true;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::has_too_many_connections(const epee::net_utils::network_address &address)
  {
    if (address.get_zone() != epee::net_utils::zone::public_)
      return false; // Unable to determine how many connections from host
 
    uint32_t count = 0;
 
    m_network_zones.at(epee::net_utils::zone::public_).m_net_server.get_config_object().foreach_connection([&](const p2p_connection_context& cntxt)
    {
      if (cntxt.m_is_income && cntxt.m_remote_address.is_same_host(address)) {
        count++;
 
        // the only call location happens BEFORE foreach_connection list is updated
        if (count >= max_connections) {
          return false;
        }
      }
 
      return true;
    });
    // the only call location happens BEFORE foreach_connection list is updated
    return count >= max_connections;
  }
 
  template<class t_payload_net_handler>
  bool node_server<t_payload_net_handler>::gray_peerlist_housekeeping()
  {
    if (m_offline) return true;
    if (!m_exclusive_peers.empty()) return true;
 
    for (auto& zone : m_network_zones)
    {
      if (m_payload_handler.needs_new_sync_connections(zone.first))
        continue;
 
      if (zone.second.m_net_server.is_stop_signal_sent())
        return false;
 
      if (zone.second.m_connect == nullptr)
        continue;
 
      peerlist_entry pe{};
      if (!zone.second.m_peerlist.get_random_gray_peer(pe))
        continue;
 
      if (!check_connection_and_handshake_with_peer(pe.adr, pe.last_seen))
      {
        zone.second.m_peerlist.remove_from_peer_gray(pe);
        LOG_PRINT_L2("PEER EVICTED FROM GRAY PEER LIST: address: " << pe.adr.host_str() << " Peer ID: " << peerid_to_string(pe.id));
      }
      else
      {
        zone.second.m_peerlist.set_peer_just_seen(pe.id, pe.adr, pe.pruning_seed, pe.rpc_port, pe.rpc_credits_per_hash);
        LOG_PRINT_L2("PEER PROMOTED TO WHITE PEER LIST IP address: " << pe.adr.host_str() << " Peer ID: " << peerid_to_string(pe.id));
      }
    }
    return true;
  }
 
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::add_used_stripe_peer(const typename t_payload_net_handler::connection_context &context)
  {
    const uint32_t stripe = tools::get_pruning_stripe(context.m_pruning_seed);
    if (stripe == 0 || stripe > (1ul << CRYPTONOTE_PRUNING_LOG_STRIPES))
      return;
    const uint32_t index = stripe - 1;
    CRITICAL_REGION_LOCAL(m_used_stripe_peers_mutex);
    MINFO("adding stripe " << stripe << " peer: " << context.m_remote_address.str());
    m_used_stripe_peers[index].erase(std::remove_if(m_used_stripe_peers[index].begin(), m_used_stripe_peers[index].end(),
        [&context](const epee::net_utils::network_address &na){ return context.m_remote_address == na; }), m_used_stripe_peers[index].end());
    m_used_stripe_peers[index].push_back(context.m_remote_address);
  }
 
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::remove_used_stripe_peer(const typename t_payload_net_handler::connection_context &context)
  {
    const uint32_t stripe = tools::get_pruning_stripe(context.m_pruning_seed);
    if (stripe == 0 || stripe > (1ul << CRYPTONOTE_PRUNING_LOG_STRIPES))
      return;
    const uint32_t index = stripe - 1;
    CRITICAL_REGION_LOCAL(m_used_stripe_peers_mutex);
    MINFO("removing stripe " << stripe << " peer: " << context.m_remote_address.str());
    m_used_stripe_peers[index].erase(std::remove_if(m_used_stripe_peers[index].begin(), m_used_stripe_peers[index].end(),
        [&context](const epee::net_utils::network_address &na){ return context.m_remote_address == na; }), m_used_stripe_peers[index].end());
  }
 
  template<class t_payload_net_handler>
  void node_server<t_payload_net_handler>::clear_used_stripe_peers()
  {
    CRITICAL_REGION_LOCAL(m_used_stripe_peers_mutex);
    MINFO("clearing used stripe peers");
    for (auto &e: m_used_stripe_peers)
      e.clear();
  }
 
  template<typename t_payload_net_handler>
  boost::optional<p2p_connection_context_t<typename t_payload_net_handler::connection_context>>
  node_server<t_payload_net_handler>::socks_connect(network_zone& zone, const epee::net_utils::network_address& remote, epee::net_utils::ssl_support_t ssl_support)
  {
    auto result = socks_connect_internal(zone.m_net_server.get_stop_signal(), zone.m_net_server.get_io_context(), zone.m_proxy_address, remote);
    if (result) // if no error
    {
      p2p_connection_context context{};
      if (zone.m_net_server.add_connection(context, std::move(*result), remote, ssl_support))
        return {std::move(context)};
    }
    return boost::none;
  }
 
  template<typename t_payload_net_handler>
  boost::optional<p2p_connection_context_t<typename t_payload_net_handler::connection_context>>
  node_server<t_payload_net_handler>::public_connect(network_zone& zone, epee::net_utils::network_address const& na, epee::net_utils::ssl_support_t ssl_support)
  {
    bool is_ipv4 = na.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id();
    bool is_ipv6 = na.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id();
    CHECK_AND_ASSERT_MES(is_ipv4 || is_ipv6, boost::none,
      "Only IPv4 or IPv6 addresses are supported here");
 
    std::string address;
    std::string port;
 
    if (is_ipv4)
    {
      const epee::net_utils::ipv4_network_address &ipv4 = na.as<const epee::net_utils::ipv4_network_address>();
      address = epee::string_tools::get_ip_string_from_int32(ipv4.ip());
      port = epee::string_tools::num_to_string_fast(ipv4.port());
    }
    else if (is_ipv6)
    {
      const epee::net_utils::ipv6_network_address &ipv6 = na.as<const epee::net_utils::ipv6_network_address>();
      address = ipv6.ip().to_string();
      port = epee::string_tools::num_to_string_fast(ipv6.port());
    }
    else
    {
      LOG_ERROR("Only IPv4 or IPv6 addresses are supported here");
      return boost::none;
    }
 
    typename net_server::t_connection_context con{};
    const bool res = zone.m_net_server.connect(address, port,
      zone.m_config.m_net_config.connection_timeout,
      con, "0.0.0.0", ssl_support);
 
    if (res)
      return {std::move(con)};
    return boost::none;
  }
}