Add IPv6 support

new cli options (RPC ones also apply to wallet):
  --p2p-bind-ipv6-address (default = "::")
  --p2p-bind-port-ipv6    (default same as ipv4 port for given nettype)
  --rpc-bind-ipv6-address (default = "::1")

  --p2p-use-ipv6          (default false)
  --rpc-use-ipv6          (default false)

  --p2p-require-ipv4      (default true, if ipv4 bind fails and this is
                           true, will not continue even if ipv6 bind
                           successful)
  --rpc-require-ipv4      (default true, description as above)

ipv6 addresses are to be specified as "[xx:xx:xx::xx:xx]:port" except
in the cases of the cli args for bind address.  For those the square
braces can be omitted.

contrib/epee/include/net/abstract_tcp_server2.h

@@ -227,8 +227,12 @@ namespace net_utils
     std::map<std::string, t_connection_type> server_type_map;
     void create_server_type_map();
 
-    bool init_server(uint32_t port, const std::string address = "0.0.0.0", ssl_options_t ssl_options = ssl_support_t::e_ssl_support_autodetect);
+    bool init_server(uint32_t port, const std::string& address = "0.0.0.0",
-    bool init_server(const std::string port,  const std::string& address = "0.0.0.0", ssl_options_t ssl_options = ssl_support_t::e_ssl_support_autodetect);
+	uint32_t port_ipv6 = 0, const std::string& address_ipv6 = "::", bool use_ipv6 = false, bool require_ipv4 = true,
+	ssl_options_t ssl_options = ssl_support_t::e_ssl_support_autodetect);
+    bool init_server(const std::string port,  const std::string& address = "0.0.0.0",
+	const std::string port_ipv6 = "", const std::string address_ipv6 = "::", bool use_ipv6 = false, bool require_ipv4 = true,
+	ssl_options_t ssl_options = ssl_support_t::e_ssl_support_autodetect);
 
     /// Run the server's io_service loop.
     bool run_server(size_t threads_count, bool wait = true, const boost::thread::attributes& attrs = boost::thread::attributes());
@@ -269,6 +273,7 @@ namespace net_utils
     }
 
     int get_binded_port(){return m_port;}
+    int get_binded_port_ipv6(){return m_port_ipv6;}
 
     long get_connections_count() const
     {
@@ -339,7 +344,9 @@ namespace net_utils
     /// Run the server's io_service loop.
     bool worker_thread();
     /// Handle completion of an asynchronous accept operation.
-    void handle_accept(const boost::system::error_code& e);
+    void handle_accept_ipv4(const boost::system::error_code& e);
+    void handle_accept_ipv6(const boost::system::error_code& e);
+    void handle_accept(const boost::system::error_code& e, bool ipv6 = false);
 
     bool is_thread_worker();
 
@@ -360,11 +367,16 @@ namespace net_utils
 
     /// Acceptor used to listen for incoming connections.
     boost::asio::ip::tcp::acceptor acceptor_;
+    boost::asio::ip::tcp::acceptor acceptor_ipv6;
     epee::net_utils::network_address default_remote;
 
     std::atomic<bool> m_stop_signal_sent;
     uint32_t m_port;
+    uint32_t m_port_ipv6;
     std::string m_address;
+    std::string m_address_ipv6;
+    bool m_use_ipv6;
+    bool m_require_ipv4;
     std::string m_thread_name_prefix; //TODO: change to enum server_type, now used
     size_t m_threads_count;
     std::vector<boost::shared_ptr<boost::thread> > m_threads;
@@ -376,6 +388,8 @@ namespace net_utils
 
     /// The next connection to be accepted
     connection_ptr new_connection_;
+    connection_ptr new_connection_ipv6;
+
 
     boost::mutex connections_mutex;
     std::set<connection_ptr> connections_;

contrib/epee/include/net/abstract_tcp_server2.inl

@@ -145,10 +145,18 @@ PRAGMA_WARNING_DISABLE_VS(4355)
     boost::system::error_code ec;
     auto remote_ep = socket().remote_endpoint(ec);
     CHECK_AND_NO_ASSERT_MES(!ec, false, "Failed to get remote endpoint: " << ec.message() << ':' << ec.value());
-    CHECK_AND_NO_ASSERT_MES(remote_ep.address().is_v4(), false, "IPv6 not supported here");
+    CHECK_AND_NO_ASSERT_MES(remote_ep.address().is_v4() || remote_ep.address().is_v6(), false, "only IPv4 and IPv6 supported here");
 
-    const unsigned long ip_{boost::asio::detail::socket_ops::host_to_network_long(remote_ep.address().to_v4().to_ulong())};
+    if (remote_ep.address().is_v4())
+    {
+      const unsigned long ip_ = boost::asio::detail::socket_ops::host_to_network_long(remote_ep.address().to_v4().to_ulong());
       return start(is_income, is_multithreaded, ipv4_network_address{uint32_t(ip_), remote_ep.port()});
+    }
+    else
+    {
+      const auto ip_{remote_ep.address().to_v6()};
+      return start(is_income, is_multithreaded, ipv6_network_address{ip_, remote_ep.port()});
+    }
     CATCH_ENTRY_L0("connection<t_protocol_handler>::start()", false);
   }
   //---------------------------------------------------------------------------------
@@ -904,12 +912,14 @@ PRAGMA_WARNING_DISABLE_VS(4355)
     m_io_service_local_instance(new worker()),
     io_service_(m_io_service_local_instance->io_service),
     acceptor_(io_service_),
+    acceptor_ipv6(io_service_),
     default_remote(),
     m_stop_signal_sent(false), m_port(0), 
     m_threads_count(0),
     m_thread_index(0),
 		m_connection_type( connection_type ),
-    new_connection_()
+    new_connection_(),
+    new_connection_ipv6()
   {
     create_server_type_map();
     m_thread_name_prefix = "NET";
@@ -920,12 +930,14 @@ PRAGMA_WARNING_DISABLE_VS(4355)
     m_state(boost::make_shared<typename connection<t_protocol_handler>::shared_state>()),
     io_service_(extarnal_io_service),
     acceptor_(io_service_),
+    acceptor_ipv6(io_service_),
     default_remote(),
     m_stop_signal_sent(false), m_port(0),
     m_threads_count(0),
     m_thread_index(0),
 		m_connection_type(connection_type),
-    new_connection_()
+    new_connection_(),
+    new_connection_ipv6()
   {
     create_server_type_map();
     m_thread_name_prefix = "NET";
@@ -947,29 +959,92 @@ PRAGMA_WARNING_DISABLE_VS(4355)
   }
   //---------------------------------------------------------------------------------
   template<class t_protocol_handler>
-  bool boosted_tcp_server<t_protocol_handler>::init_server(uint32_t port, const std::string address, ssl_options_t ssl_options)
+    bool boosted_tcp_server<t_protocol_handler>::init_server(uint32_t port,  const std::string& address,
+	uint32_t port_ipv6, const std::string& address_ipv6, bool use_ipv6, bool require_ipv4,
+	ssl_options_t ssl_options)
   {
     TRY_ENTRY();
     m_stop_signal_sent = false;
     m_port = port;
+    m_port_ipv6 = port_ipv6;
     m_address = address;
+    m_address_ipv6 = address_ipv6;
+    m_use_ipv6 = use_ipv6;
+    m_require_ipv4 = require_ipv4;
+
     if (ssl_options)
       m_state->configure_ssl(std::move(ssl_options));
-    // Open the acceptor with the option to reuse the address (i.e. SO_REUSEADDR).
+
+    std::string ipv4_failed = "";
+    std::string ipv6_failed = "";
+    try
+    {
       boost::asio::ip::tcp::resolver resolver(io_service_);
       boost::asio::ip::tcp::resolver::query query(address, boost::lexical_cast<std::string>(port), boost::asio::ip::tcp::resolver::query::canonical_name);
       boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query);
       acceptor_.open(endpoint.protocol());
+      // Open the acceptor with the option to reuse the address (i.e. SO_REUSEADDR).
       acceptor_.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
       acceptor_.bind(endpoint);
       acceptor_.listen();
       boost::asio::ip::tcp::endpoint binded_endpoint = acceptor_.local_endpoint();
       m_port = binded_endpoint.port();
-    MDEBUG("start accept");
+      MDEBUG("start accept (IPv4)");
       new_connection_.reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, m_state->ssl_options().support));
       acceptor_.async_accept(new_connection_->socket(),
-      boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept, this,
+	boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept_ipv4, this,
 	boost::asio::placeholders::error));
+    }
+    catch (const std::exception &e)
+    {
+      ipv4_failed = e.what();
+    }
+
+    if (ipv4_failed != "")
+    {
+      MERROR("Failed to bind IPv4: " << ipv4_failed);
+      if (require_ipv4)
+      {
+        throw std::runtime_error("Failed to bind IPv4 (set to required)");
+      }
+    }
+
+    if (use_ipv6)
+    {
+      try
+      {
+        if (port_ipv6 == 0) port_ipv6 = port; // default arg means bind to same port as ipv4
+        boost::asio::ip::tcp::resolver resolver(io_service_);
+        boost::asio::ip::tcp::resolver::query query(address_ipv6, boost::lexical_cast<std::string>(port_ipv6), boost::asio::ip::tcp::resolver::query::canonical_name);
+        boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query);
+        acceptor_ipv6.open(endpoint.protocol());
+        // Open the acceptor with the option to reuse the address (i.e. SO_REUSEADDR).
+        acceptor_ipv6.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true));
+        acceptor_ipv6.set_option(boost::asio::ip::v6_only(true));
+        acceptor_ipv6.bind(endpoint);
+        acceptor_ipv6.listen();
+        boost::asio::ip::tcp::endpoint binded_endpoint = acceptor_ipv6.local_endpoint();
+        m_port_ipv6 = binded_endpoint.port();
+        MDEBUG("start accept (IPv6)");
+        new_connection_ipv6.reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, m_state->ssl_options().support));
+        acceptor_ipv6.async_accept(new_connection_ipv6->socket(),
+            boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept_ipv6, this,
+              boost::asio::placeholders::error));
+      }
+      catch (const std::exception &e)
+      {
+        ipv6_failed = e.what();
+      }
+    }
+
+      if (use_ipv6 && ipv6_failed != "")
+      {
+        MERROR("Failed to bind IPv6: " << ipv6_failed);
+        if (ipv4_failed != "")
+        {
+          throw std::runtime_error("Failed to bind IPv4 and IPv6");
+        }
+      }
 
     return true;
     }
@@ -988,15 +1063,23 @@ PRAGMA_WARNING_DISABLE_VS(4355)
 PUSH_WARNINGS
 DISABLE_GCC_WARNING(maybe-uninitialized)
   template<class t_protocol_handler>
-  bool boosted_tcp_server<t_protocol_handler>::init_server(const std::string port, const std::string& address, ssl_options_t ssl_options)
+  bool boosted_tcp_server<t_protocol_handler>::init_server(const std::string port,  const std::string& address,
+      const std::string port_ipv6, const std::string address_ipv6, bool use_ipv6, bool require_ipv4,
+      ssl_options_t ssl_options)
   {
     uint32_t p = 0;
+    uint32_t p_ipv6 = 0;
 
     if (port.size() && !string_tools::get_xtype_from_string(p, port)) {
       MERROR("Failed to convert port no = " << port);
       return false;
     }
-    return this->init_server(p, address, std::move(ssl_options));
+
+    if (port_ipv6.size() && !string_tools::get_xtype_from_string(p_ipv6, port_ipv6)) {
+      MERROR("Failed to convert port no = " << port_ipv6);
+      return false;
+    }
+    return this->init_server(p, address, p_ipv6, address_ipv6, use_ipv6, require_ipv4, std::move(ssl_options));
   }
 POP_WARNINGS
   //---------------------------------------------------------------------------------
@@ -1088,7 +1171,7 @@ POP_WARNINGS
       {
         //some problems with the listening socket ?..
         _dbg1("Net service stopped without stop request, restarting...");
-        if(!this->init_server(m_port, m_address))
+        if(!this->init_server(m_port, m_address, m_port_ipv6, m_address_ipv6, m_use_ipv6, m_require_ipv4))
         {
           _dbg1("Reiniting service failed, exit.");
           return false;
@@ -1154,28 +1237,51 @@ POP_WARNINGS
   }
   //---------------------------------------------------------------------------------
   template<class t_protocol_handler>
-  void boosted_tcp_server<t_protocol_handler>::handle_accept(const boost::system::error_code& e)
+  void boosted_tcp_server<t_protocol_handler>::handle_accept_ipv4(const boost::system::error_code& e)
+  {
+    this->handle_accept(e, false);
+  }
+  //---------------------------------------------------------------------------------
+  template<class t_protocol_handler>
+  void boosted_tcp_server<t_protocol_handler>::handle_accept_ipv6(const boost::system::error_code& e)
+  {
+    this->handle_accept(e, true);
+  }
+  //---------------------------------------------------------------------------------
+  template<class t_protocol_handler>
+  void boosted_tcp_server<t_protocol_handler>::handle_accept(const boost::system::error_code& e, bool ipv6)
   {
     MDEBUG("handle_accept");
+
+    boost::asio::ip::tcp::acceptor* current_acceptor = &acceptor_;
+    connection_ptr* current_new_connection = &new_connection_;
+    auto accept_function_pointer = &boosted_tcp_server<t_protocol_handler>::handle_accept_ipv4;
+    if (ipv6)
+    {
+      current_acceptor = &acceptor_ipv6;
+      current_new_connection = &new_connection_ipv6;
+      accept_function_pointer = &boosted_tcp_server<t_protocol_handler>::handle_accept_ipv6;
+    }
+
     try
     {
     if (!e)
     {
       if (m_connection_type == e_connection_type_RPC) {
         const char *ssl_message = "unknown";
-			switch (new_connection_->get_ssl_support())
+        switch ((*current_new_connection)->get_ssl_support())
         {
           case epee::net_utils::ssl_support_t::e_ssl_support_disabled: ssl_message = "disabled"; break;
           case epee::net_utils::ssl_support_t::e_ssl_support_enabled: ssl_message = "enabled"; break;
           case epee::net_utils::ssl_support_t::e_ssl_support_autodetect: ssl_message = "autodetection"; break;
         }
         MDEBUG("New server for RPC connections, SSL " << ssl_message);
-			new_connection_->setRpcStation(); // hopefully this is not needed actually
+        (*current_new_connection)->setRpcStation(); // hopefully this is not needed actually
       }
-		connection_ptr conn(std::move(new_connection_));
+      connection_ptr conn(std::move((*current_new_connection)));
-      new_connection_.reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, conn->get_ssl_support()));
+      (*current_new_connection).reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, conn->get_ssl_support()));
-      acceptor_.async_accept(new_connection_->socket(),
+      current_acceptor->async_accept((*current_new_connection)->socket(),
-        boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept, this,
+          boost::bind(accept_function_pointer, this,
             boost::asio::placeholders::error));
 
       boost::asio::socket_base::keep_alive opt(true);
@@ -1208,9 +1314,9 @@ POP_WARNINGS
     assert(m_state != nullptr); // always set in constructor
     _erro("Some problems at accept: " << e.message() << ", connections_count = " << m_state->sock_count);
     misc_utils::sleep_no_w(100);
-    new_connection_.reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, new_connection_->get_ssl_support()));
+    (*current_new_connection).reset(new connection<t_protocol_handler>(io_service_, m_state, m_connection_type, (*current_new_connection)->get_ssl_support()));
-    acceptor_.async_accept(new_connection_->socket(),
+    current_acceptor->async_accept((*current_new_connection)->socket(),
-      boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept, this,
+        boost::bind(accept_function_pointer, this,
           boost::asio::placeholders::error));
   }
   //---------------------------------------------------------------------------------
@@ -1345,23 +1451,84 @@ POP_WARNINGS
     epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){ CRITICAL_REGION_LOCAL(connections_mutex); connections_.erase(new_connection_l); });
     boost::asio::ip::tcp::socket&  sock_ = new_connection_l->socket();
 
-    //////////////////////////////////////////////////////////////////////////
+    bool try_ipv6 = false;
+
     boost::asio::ip::tcp::resolver resolver(io_service_);
     boost::asio::ip::tcp::resolver::query query(boost::asio::ip::tcp::v4(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
-    boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);
+    boost::system::error_code resolve_error;
+    boost::asio::ip::tcp::resolver::iterator iterator;
+    try
+    {
+      //resolving ipv4 address as ipv6 throws, catch here and move on
+      iterator = resolver.resolve(query, resolve_error);
+    }
+    catch (const boost::system::system_error& e)
+    {
+      if (!m_use_ipv6 || (resolve_error != boost::asio::error::host_not_found &&
+            resolve_error != boost::asio::error::host_not_found_try_again))
+      {
+        throw;
+      }
+      try_ipv6 = true;
+    }
+    catch (...)
+    {
+      throw;
+    }
+
+    std::string bind_ip_to_use;
+
     boost::asio::ip::tcp::resolver::iterator end;
+    if(iterator == end)
+    {
+      if (!m_use_ipv6)
+      {
+        _erro("Failed to resolve " << adr);
+        return false;
+      }
+      else
+      {
+        try_ipv6 = true;
+        MINFO("Resolving address as IPv4 failed, trying IPv6");
+      }
+    }
+    else
+    {
+      bind_ip_to_use = bind_ip;
+    }
+
+    if (try_ipv6)
+    {
+      boost::asio::ip::tcp::resolver::query query6(boost::asio::ip::tcp::v6(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
+
+      iterator = resolver.resolve(query6, resolve_error);
+
       if(iterator == end)
       {
         _erro("Failed to resolve " << adr);
         return false;
       }
-    //////////////////////////////////////////////////////////////////////////
+      else
+      {
+        if (bind_ip == "0.0.0.0")
+        {
+          bind_ip_to_use = "::";
+        }
+        else
+        {
+          bind_ip_to_use = "";
+        }
 
+      }
+
+    }
+
+    LOG_ERROR("Trying connect to " << adr << ":" << port << ", bind_ip = " << bind_ip_to_use);
 
     //boost::asio::ip::tcp::endpoint remote_endpoint(boost::asio::ip::address::from_string(addr.c_str()), port);
     boost::asio::ip::tcp::endpoint remote_endpoint(*iterator);
 
-    auto try_connect_result = try_connect(new_connection_l, adr, port, sock_, remote_endpoint, bind_ip, conn_timeout, ssl_support);
+    auto try_connect_result = try_connect(new_connection_l, adr, port, sock_, remote_endpoint, bind_ip_to_use, conn_timeout, ssl_support);
     if (try_connect_result == CONNECT_FAILURE)
       return false;
     if (ssl_support == epee::net_utils::ssl_support_t::e_ssl_support_autodetect && try_connect_result == CONNECT_NO_SSL)
@@ -1369,7 +1536,7 @@ POP_WARNINGS
       // we connected, but could not connect with SSL, try without
       MERROR("SSL handshake failed on an autodetect connection, reconnecting without SSL");
       new_connection_l->disable_ssl();
-      try_connect_result = try_connect(new_connection_l, adr, port, sock_, remote_endpoint, bind_ip, conn_timeout, epee::net_utils::ssl_support_t::e_ssl_support_disabled);
+      try_connect_result = try_connect(new_connection_l, adr, port, sock_, remote_endpoint, bind_ip_to_use, conn_timeout, epee::net_utils::ssl_support_t::e_ssl_support_disabled);
       if (try_connect_result != CONNECT_SUCCESS)
         return false;
     }
@@ -1409,17 +1576,59 @@ POP_WARNINGS
     epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){ CRITICAL_REGION_LOCAL(connections_mutex); connections_.erase(new_connection_l); });
     boost::asio::ip::tcp::socket&  sock_ = new_connection_l->socket();
     
-    //////////////////////////////////////////////////////////////////////////
+    bool try_ipv6 = false;
+
     boost::asio::ip::tcp::resolver resolver(io_service_);
     boost::asio::ip::tcp::resolver::query query(boost::asio::ip::tcp::v4(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
-    boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);
+    boost::system::error_code resolve_error;
+    boost::asio::ip::tcp::resolver::iterator iterator;
+    try
+    {
+      //resolving ipv4 address as ipv6 throws, catch here and move on
+      iterator = resolver.resolve(query, resolve_error);
+    }
+    catch (const boost::system::system_error& e)
+    {
+      if (!m_use_ipv6 || (resolve_error != boost::asio::error::host_not_found &&
+            resolve_error != boost::asio::error::host_not_found_try_again))
+      {
+        throw;
+      }
+      try_ipv6 = true;
+    }
+    catch (...)
+    {
+      throw;
+    }
+
     boost::asio::ip::tcp::resolver::iterator end;
+    if(iterator == end)
+    {
+      if (!try_ipv6)
+      {
+        _erro("Failed to resolve " << adr);
+        return false;
+      }
+      else
+      {
+        MINFO("Resolving address as IPv4 failed, trying IPv6");
+      }
+    }
+
+    if (try_ipv6)
+    {
+      boost::asio::ip::tcp::resolver::query query6(boost::asio::ip::tcp::v6(), adr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
+
+      iterator = resolver.resolve(query6, resolve_error);
+
       if(iterator == end)
       {
         _erro("Failed to resolve " << adr);
         return false;
       }
-    //////////////////////////////////////////////////////////////////////////
+    }
+
+
     boost::asio::ip::tcp::endpoint remote_endpoint(*iterator);
      
     sock_.open(remote_endpoint.protocol());

contrib/epee/include/net/http_server_impl_base.h

@@ -57,6 +57,7 @@ namespace epee
     {}
 
     bool init(std::function<void(size_t, uint8_t*)> rng, const std::string& bind_port = "0", const std::string& bind_ip = "0.0.0.0",
+      const std::string& bind_ipv6_address = "::", bool use_ipv6 = false, bool require_ipv4 = true,
       std::vector<std::string> access_control_origins = std::vector<std::string>(),
       boost::optional<net_utils::http::login> user = boost::none,
       net_utils::ssl_options_t ssl_options = net_utils::ssl_support_t::e_ssl_support_autodetect)
@@ -75,8 +76,12 @@ namespace epee
 
       m_net_server.get_config_object().m_user = std::move(user);
 
-      MGINFO("Binding on " << bind_ip << ":" << bind_port);
+      MGINFO("Binding on " << bind_ip << " (IPv4):" << bind_port);
-      bool res = m_net_server.init_server(bind_port, bind_ip, std::move(ssl_options));
+      if (use_ipv6)
+      {
+        MGINFO("Binding on " << bind_ipv6_address << " (IPv6):" << bind_port);
+      }
+      bool res = m_net_server.init_server(bind_port, bind_ip, bind_port, bind_ipv6_address, use_ipv6, require_ipv4, std::move(ssl_options));
       if(!res)
       {
         LOG_ERROR("Failed to bind server");

contrib/epee/include/net/local_ip.h

@@ -27,10 +27,38 @@
 
 #pragma once
 
+#include <string>
+#include <boost/algorithm/string/predicate.hpp>
+#include <boost/asio/ip/address_v6.hpp>
+
 namespace epee
 {
   namespace net_utils
   {
+
+    inline
+    bool is_ipv6_local(const std::string& ip)
+    {
+      auto addr = boost::asio::ip::make_address_v6(ip);
+
+      // ipv6 link-local unicast addresses are fe80::/10
+      bool is_link_local = addr.is_link_local();
+
+      auto addr_bytes = addr.to_bytes();
+
+      // ipv6 unique local unicast addresses start with fc00::/7 -- (fcXX or fdXX)
+      bool is_unique_local_unicast = (addr_bytes[0] == 0xfc || addr_bytes[0] == 0xfd);
+
+      return is_link_local || is_unique_local_unicast;
+    }
+
+    inline
+    bool is_ipv6_loopback(const std::string& ip)
+    {
+      // ipv6 loopback is ::1
+      return boost::asio::ip::address_v6::from_string(ip).is_loopback();
+    }
+
     inline
     bool is_ip_local(uint32_t ip)
     {

contrib/epee/include/net/net_parse_helpers.h

@@ -128,11 +128,51 @@ namespace net_utils
     return true;
   }
 
+  inline
+    bool parse_url_ipv6(const std::string url_str, http::url_content& content)
+  {
+    STATIC_REGEXP_EXPR_1(rexp_match_uri, "^((.*?)://)?(\\[(.*)\\](:(\\d+))?)(.*)?", boost::regex::icase | boost::regex::normal);
+    //                                     12         3   4      5 6        7
+
+    content.port = 0;
+    boost::smatch result;
+    if(!(boost::regex_search(url_str, result, rexp_match_uri, boost::match_default) && result[0].matched))
+    {
+      LOG_PRINT_L1("[PARSE URI] regex not matched for uri: " << rexp_match_uri);
+      //content.m_path = uri;
+      return false;
+    }
+    if(result[2].matched)
+    {
+      content.schema = result[2];
+    }
+    if(result[4].matched)
+    {
+      content.host = result[4];
+    }
+    else  // if host not matched, matching should be considered failed
+    {
+      return false;
+    }
+    if(result[6].matched)
+    {
+      content.port = boost::lexical_cast<uint64_t>(result[6]);
+    }
+    if(result[7].matched)
+    {
+      content.uri = result[7];
+      return parse_uri(result[7], content.m_uri_content);
+    }
+
+    return true;
+  }
 
   inline
     bool parse_url(const std::string url_str, http::url_content& content)
   {
 
+    if (parse_url_ipv6(url_str, content)) return true;
+
     ///iframe_test.html?api_url=http://api.vk.com/api.php&api_id=3289090&api_settings=1&viewer_id=562964060&viewer_type=0&sid=0aad8d1c5713130f9ca0076f2b7b47e532877424961367d81e7fa92455f069be7e21bc3193cbd0be11895&secret=368ebbc0ef&access_token=668bc03f43981d883f73876ffff4aa8564254b359cc745dfa1b3cde7bdab2e94105d8f6d8250717569c0a7&user_id=0&group_id=0&is_app_user=1&auth_key=d2f7a895ca5ff3fdb2a2a8ae23fe679a&language=0&parent_language=0&ad_info=ElsdCQBaQlxiAQRdFUVUXiN2AVBzBx5pU1BXIgZUJlIEAWcgAUoLQg==&referrer=unknown&lc_name=9834b6a3&hash=
     //STATIC_REGEXP_EXPR_1(rexp_match_uri, "^([^?#]*)(\\?([^#]*))?(#(.*))?", boost::regex::icase | boost::regex::normal);
     STATIC_REGEXP_EXPR_1(rexp_match_uri, "^((.*?)://)?(([^/:]*)(:(\\d+))?)(.*)?", boost::regex::icase | boost::regex::normal);

contrib/epee/include/net/net_utils_base.h

@@ -31,6 +31,7 @@
 
 #include <boost/uuid/uuid.hpp>
 #include <boost/asio/io_service.hpp>
+#include <boost/asio/ip/address_v6.hpp>
 #include <typeinfo>
 #include <type_traits>
 #include "enums.h"
@@ -154,6 +155,59 @@ namespace net_utils
 	inline bool operator>=(const ipv4_network_subnet& lhs, const ipv4_network_subnet& rhs) noexcept
 	{ return !lhs.less(rhs); }
 
+	class ipv6_network_address
+	{
+	protected:
+		boost::asio::ip::address_v6 m_address;
+		uint16_t m_port;
+
+	public:
+		ipv6_network_address()
+			: ipv6_network_address(boost::asio::ip::address_v6::loopback(), 0)
+		{}
+
+		ipv6_network_address(const boost::asio::ip::address_v6& ip, uint16_t port)
+			: m_address(ip), m_port(port)
+		{
+		}
+
+		bool equal(const ipv6_network_address& other) const noexcept;
+		bool less(const ipv6_network_address& other) const noexcept;
+		bool is_same_host(const ipv6_network_address& other) const noexcept
+		{ return m_address == other.m_address; }
+
+		boost::asio::ip::address_v6 ip() const noexcept { return m_address; }
+		uint16_t port() const noexcept { return m_port; }
+		std::string str() const;
+		std::string host_str() const;
+		bool is_loopback() const;
+		bool is_local() const;
+		static constexpr address_type get_type_id() noexcept { return address_type::ipv6; }
+		static constexpr zone get_zone() noexcept { return zone::public_; }
+		static constexpr bool is_blockable() noexcept { return true; }
+
+		static const uint8_t ID = 2;
+		BEGIN_KV_SERIALIZE_MAP()
+			boost::asio::ip::address_v6::bytes_type bytes = this_ref.m_address.to_bytes();
+			epee::serialization::selector<is_store>::serialize_t_val_as_blob(bytes, stg, hparent_section, "addr");
+			const_cast<boost::asio::ip::address_v6&>(this_ref.m_address) = boost::asio::ip::address_v6(bytes);
+			KV_SERIALIZE(m_port)
+		END_KV_SERIALIZE_MAP()
+	};
+
+	inline bool operator==(const ipv6_network_address& lhs, const ipv6_network_address& rhs) noexcept
+	{ return lhs.equal(rhs); }
+	inline bool operator!=(const ipv6_network_address& lhs, const ipv6_network_address& rhs) noexcept
+	{ return !lhs.equal(rhs); }
+	inline bool operator<(const ipv6_network_address& lhs, const ipv6_network_address& rhs) noexcept
+	{ return lhs.less(rhs); }
+	inline bool operator<=(const ipv6_network_address& lhs, const ipv6_network_address& rhs) noexcept
+	{ return !rhs.less(lhs); }
+	inline bool operator>(const ipv6_network_address& lhs, const ipv6_network_address& rhs) noexcept
+	{ return rhs.less(lhs); }
+	inline bool operator>=(const ipv6_network_address& lhs, const ipv6_network_address& rhs) noexcept
+	{ return !lhs.less(rhs); }
+
 	class network_address
 	{
 		struct interface
@@ -261,6 +315,8 @@ namespace net_utils
 			{
 				case address_type::ipv4:
 					return this_ref.template serialize_addr<ipv4_network_address>(is_store_, stg, hparent_section);
+				case address_type::ipv6:
+					return this_ref.template serialize_addr<ipv6_network_address>(is_store_, stg, hparent_section);
 				case address_type::tor:
 					return this_ref.template serialize_addr<net::tor_address>(is_store_, stg, hparent_section);
 				case address_type::i2p:

contrib/epee/src/net_helper.cpp

@@ -11,10 +11,39 @@ namespace net_utils
 		//////////////////////////////////////////////////////////////////////////
 		boost::asio::ip::tcp::resolver resolver(GET_IO_SERVICE(timeout));
 		boost::asio::ip::tcp::resolver::query query(boost::asio::ip::tcp::v4(), addr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
-		boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);
+
+		bool try_ipv6 = false;
+		boost::asio::ip::tcp::resolver::iterator iterator;
 		boost::asio::ip::tcp::resolver::iterator end;
+		boost::system::error_code resolve_error;
+		try
+		{
+			iterator = resolver.resolve(query, resolve_error);
 			if(iterator == end) // Documentation states that successful call is guaranteed to be non-empty
+			{
+				// if IPv4 resolution fails, try IPv6.  Unintentional outgoing IPv6 connections should only
+				// be possible if for some reason a hostname was given and that hostname fails IPv4 resolution,
+				// so at least for now there should not be a need for a flag "using ipv6 is ok"
+				try_ipv6 = true;
+			}
+
+		}
+		catch (const boost::system::system_error& e)
+		{
+			if (resolve_error != boost::asio::error::host_not_found &&
+					resolve_error != boost::asio::error::host_not_found_try_again)
+			{
+				throw;
+			}
+			try_ipv6 = true;
+		}
+		if (try_ipv6)
+		{
+			boost::asio::ip::tcp::resolver::query query6(boost::asio::ip::tcp::v6(), addr, port, boost::asio::ip::tcp::resolver::query::canonical_name);
+			iterator = resolver.resolve(query6);
+			if (iterator == end)
 				throw boost::system::system_error{boost::asio::error::fault, "Failed to resolve " + addr};
+		}
 
 		//////////////////////////////////////////////////////////////////////////
 

contrib/epee/src/net_utils_base.cpp

@@ -21,6 +21,19 @@ namespace epee { namespace net_utils
 	bool ipv4_network_address::is_loopback() const { return net_utils::is_ip_loopback(ip()); }
 	bool ipv4_network_address::is_local() const { return net_utils::is_ip_local(ip()); }
 
+	bool ipv6_network_address::equal(const ipv6_network_address& other) const noexcept
+	{ return is_same_host(other) && port() == other.port(); }
+
+	bool ipv6_network_address::less(const ipv6_network_address& other) const noexcept
+	{ return is_same_host(other) ? port() < other.port() : m_address < other.m_address; }
+
+	std::string ipv6_network_address::str() const
+	{ return std::string("[") + host_str() + "]:" + std::to_string(port()); }
+
+	std::string ipv6_network_address::host_str() const { return m_address.to_string(); }
+	bool ipv6_network_address::is_loopback() const { return m_address.is_loopback(); }
+	bool ipv6_network_address::is_local() const { return m_address.is_link_local(); }
+
 
 	bool ipv4_network_subnet::equal(const ipv4_network_subnet& other) const noexcept
 	{ return is_same_host(other) && m_mask == other.m_mask; }

src/daemon/rpc_command_executor.cpp

@@ -68,7 +68,7 @@ namespace {
     std::string id_str;
     std::string port_str;
     std::string elapsed = peer.last_seen == 0 ? "never" : epee::misc_utils::get_time_interval_string(now - last_seen);
-    std::string ip_str = epee::string_tools::get_ip_string_from_int32(peer.ip);
+    std::string ip_str = peer.ip != 0 ? epee::string_tools::get_ip_string_from_int32(peer.ip) : std::string("[") + peer.host + "]";
     std::stringstream peer_id_str;
     peer_id_str << std::hex << std::setw(16) << peer.id;
     peer_id_str >> id_str;

src/net/parse.cpp

@@ -34,28 +34,69 @@
 
 namespace net
 {
+    void get_network_address_host_and_port(const std::string& address, std::string& host, std::string& port)
+    {
+        // require ipv6 address format "[addr:addr:addr:...:addr]:port"
+        if (address.find(']') != std::string::npos)
+        {
+            host = address.substr(1, address.rfind(']') - 1);
+            if ((host.size() + 2) < address.size())
+            {
+                port = address.substr(address.rfind(':') + 1);
+            }
+        }
+        else
+        {
+            host = address.substr(0, address.rfind(':'));
+            if (host.size() < address.size())
+            {
+                port = address.substr(host.size() + 1);
+            }
+        }
+    }
+
     expect<epee::net_utils::network_address>
     get_network_address(const boost::string_ref address, const std::uint16_t default_port)
     {
-        const boost::string_ref host = address.substr(0, address.rfind(':'));
+        std::string host_str = "";
+        std::string port_str = "";
 
-        if (host.empty())
+        bool ipv6 = false;
+
+        get_network_address_host_and_port(std::string(address), host_str, port_str);
+
+        boost::string_ref host_str_ref(host_str);
+        boost::string_ref port_str_ref(port_str);
+
+        if (host_str.empty())
             return make_error_code(net::error::invalid_host);
-        if (host.ends_with(".onion"))
+        if (host_str_ref.ends_with(".onion"))
             return tor_address::make(address, default_port);
-        if (host.ends_with(".i2p"))
+        if (host_str_ref.ends_with(".i2p"))
             return i2p_address::make(address, default_port);
 
+        boost::system::error_code ec;
+        boost::asio::ip::address_v6 v6 = boost::asio::ip::make_address_v6(host_str, ec);
+        ipv6 = !ec;
+
         std::uint16_t port = default_port;
-        if (host.size() < address.size())
+        if (port_str.size())
         {
-            if (!epee::string_tools::get_xtype_from_string(port, std::string{address.substr(host.size() + 1)}))
+            if (!epee::string_tools::get_xtype_from_string(port, port_str))
                 return make_error_code(net::error::invalid_port);
         }
 
+        if (ipv6)
+        {
+            return {epee::net_utils::ipv6_network_address{v6, port}};
+        }
+        else
+        {
             std::uint32_t ip = 0;
-        if (epee::string_tools::get_ip_int32_from_string(ip, std::string{host}))
+            if (epee::string_tools::get_ip_int32_from_string(ip, host_str))
                 return {epee::net_utils::ipv4_network_address{ip, port}};
+        }
+
         return make_error_code(net::error::unsupported_address);
     }
 

src/net/parse.h

@@ -36,6 +36,8 @@
 
 namespace net
 {
+    void get_network_address_host_and_port(const std::string& address, std::string& host, std::string& port);
+
     /*!
       Identifies onion, i2p and IPv4 addresses and returns them as a generic
       `network_address`. If the type is unsupported, it might be a hostname,

src/p2p/net_node.cpp

@@ -108,10 +108,11 @@ namespace
 
 namespace nodetool
 {
-    const command_line::arg_descriptor<std::string> arg_p2p_bind_ip        = {"p2p-bind-ip", "Interface for p2p network protocol", "0.0.0.0"};
+    const command_line::arg_descriptor<std::string> arg_p2p_bind_ip        = {"p2p-bind-ip", "Interface for p2p network protocol (IPv4)", "0.0.0.0"};
+    const command_line::arg_descriptor<std::string> arg_p2p_bind_ipv6_address        = {"p2p-bind-ipv6-address", "Interface for p2p network protocol (IPv6)", "::"};
     const command_line::arg_descriptor<std::string, false, true, 2> arg_p2p_bind_port = {
         "p2p-bind-port"
-      , "Port for p2p network protocol"
+      , "Port for p2p network protocol (IPv4)"
       , std::to_string(config::P2P_DEFAULT_PORT)
       , {{ &cryptonote::arg_testnet_on, &cryptonote::arg_stagenet_on }}
       , [](std::array<bool, 2> testnet_stagenet, bool defaulted, std::string val)->std::string {
@@ -122,6 +123,20 @@ namespace nodetool
           return val;
         }
       };
+    const command_line::arg_descriptor<std::string, false, true, 2> arg_p2p_bind_port_ipv6 = {
+        "p2p-bind-port-ipv6"
+      , "Port for p2p network protocol (IPv6)"
+      , std::to_string(config::P2P_DEFAULT_PORT)
+      , {{ &cryptonote::arg_testnet_on, &cryptonote::arg_stagenet_on }}
+      , [](std::array<bool, 2> testnet_stagenet, bool defaulted, std::string val)->std::string {
+          if (testnet_stagenet[0] && defaulted)
+            return std::to_string(config::testnet::P2P_DEFAULT_PORT);
+          else if (testnet_stagenet[1] && defaulted)
+            return std::to_string(config::stagenet::P2P_DEFAULT_PORT);
+          return val;
+        }
+      };
+
     const command_line::arg_descriptor<uint32_t>    arg_p2p_external_port  = {"p2p-external-port", "External port for p2p network protocol (if port forwarding used with NAT)", 0};
     const command_line::arg_descriptor<bool>        arg_p2p_allow_local_ip = {"allow-local-ip", "Allow local ip add to peer list, mostly in debug purposes"};
     const command_line::arg_descriptor<std::vector<std::string> > arg_p2p_add_peer   = {"add-peer", "Manually add peer to local peerlist"};
@@ -136,6 +151,8 @@ namespace nodetool
 
     const command_line::arg_descriptor<bool>        arg_no_igd  = {"no-igd", "Disable UPnP port mapping"};
     const command_line::arg_descriptor<std::string> arg_igd = {"igd", "UPnP port mapping (disabled, enabled, delayed)", "delayed"};
+    const command_line::arg_descriptor<bool>        arg_p2p_use_ipv6  = {"p2p-use-ipv6", "Enable IPv6 for p2p", false};
+    const command_line::arg_descriptor<bool>        arg_p2p_require_ipv4  = {"p2p-require-ipv4", "Require successful IPv4 bind for p2p", true};
     const command_line::arg_descriptor<int64_t>     arg_out_peers = {"out-peers", "set max number of out peers", -1};
     const command_line::arg_descriptor<int64_t>     arg_in_peers = {"in-peers", "set max number of in peers", -1};
     const command_line::arg_descriptor<int> arg_tos_flag = {"tos-flag", "set TOS flag", -1};

src/p2p/net_node.h

@@ -151,7 +151,9 @@ namespace nodetool
         : m_connect(nullptr),
           m_net_server(epee::net_utils::e_connection_type_P2P),
           m_bind_ip(),
+          m_bind_ipv6_address(),
           m_port(),
+          m_port_ipv6(),
           m_our_address(),
           m_peerlist(),
           m_config{},
@@ -167,7 +169,9 @@ namespace nodetool
         : m_connect(nullptr),
           m_net_server(public_service, epee::net_utils::e_connection_type_P2P),
           m_bind_ip(),
+          m_bind_ipv6_address(),
           m_port(),
+          m_port_ipv6(),
           m_our_address(),
           m_peerlist(),
           m_config{},
@@ -182,7 +186,9 @@ namespace nodetool
       connect_func* m_connect;
       net_server m_net_server;
       std::string m_bind_ip;
+      std::string m_bind_ipv6_address;
       std::string m_port;
+      std::string m_port_ipv6;
       epee::net_utils::network_address m_our_address; // in anonymity networks
       peerlist_manager m_peerlist;
       config m_config;
@@ -357,7 +363,13 @@ namespace nodetool
     bool is_peer_used(const peerlist_entry& peer);
     bool is_peer_used(const anchor_peerlist_entry& peer);
     bool is_addr_connected(const epee::net_utils::network_address& peer);
-    void add_upnp_port_mapping(uint32_t port);
+    void add_upnp_port_mapping_impl(uint32_t port, bool ipv6=false);
+    void add_upnp_port_mapping_v4(uint32_t port);
+    void add_upnp_port_mapping_v6(uint32_t port);
+    void add_upnp_port_mapping(uint32_t port, bool ipv4=true, bool ipv6=false);
+    void delete_upnp_port_mapping_impl(uint32_t port, bool ipv6=false);
+    void delete_upnp_port_mapping_v4(uint32_t port);
+    void delete_upnp_port_mapping_v6(uint32_t port);
     void delete_upnp_port_mapping(uint32_t port);
     template<class t_callback>
     bool try_ping(basic_node_data& node_data, p2p_connection_context& context, const t_callback &cb);
@@ -419,12 +431,15 @@ namespace nodetool
     bool m_have_address;
     bool m_first_connection_maker_call;
     uint32_t m_listening_port;
+    uint32_t m_listening_port_ipv6;
     uint32_t m_external_port;
     uint16_t m_rpc_port;
     bool m_allow_local_ip;
     bool m_hide_my_port;
     igd_t m_igd;
     bool m_offline;
+    bool m_use_ipv6;
+    bool m_require_ipv4;
     std::atomic<bool> is_closing;
     std::unique_ptr<boost::thread> mPeersLoggerThread;
     //critical_section m_connections_lock;
@@ -485,7 +500,11 @@ namespace nodetool
     const int64_t default_limit_up = P2P_DEFAULT_LIMIT_RATE_UP;      // kB/s
     const int64_t default_limit_down = P2P_DEFAULT_LIMIT_RATE_DOWN;  // kB/s
     extern const command_line::arg_descriptor<std::string> arg_p2p_bind_ip;
+    extern const command_line::arg_descriptor<std::string> arg_p2p_bind_ipv6_address;
     extern const command_line::arg_descriptor<std::string, false, true, 2> arg_p2p_bind_port;
+    extern const command_line::arg_descriptor<std::string, false, true, 2> arg_p2p_bind_port_ipv6;
+    extern const command_line::arg_descriptor<bool>        arg_p2p_use_ipv6;
+    extern const command_line::arg_descriptor<bool>        arg_p2p_require_ipv4;
     extern const command_line::arg_descriptor<uint32_t>    arg_p2p_external_port;
     extern const command_line::arg_descriptor<bool>        arg_p2p_allow_local_ip;
     extern const command_line::arg_descriptor<std::vector<std::string> > arg_p2p_add_peer;

src/p2p/net_node.inl

@@ -93,7 +93,11 @@ namespace nodetool
   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_require_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);
@@ -341,7 +345,9 @@ namespace nodetool
     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);
@@ -375,6 +381,8 @@ namespace nodetool
       return false;
     }
     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_require_ipv4);
 
     if (command_line::has_arg(vm, arg_p2p_add_peer))
     {
@@ -518,12 +526,17 @@ namespace nodetool
 
     std::string host = addr;
     std::string port = std::to_string(default_port);
-    size_t pos = addr.find_last_of(':');
+    size_t colon_pos = addr.find_last_of(':');
-    if (std::string::npos != pos)
+    size_t dot_pos = addr.find_last_of('.');
+    size_t square_brace_pos = addr.find('[');
+
+    // IPv6 will have colons regardless.  IPv6 and IPv4 address:port will have a colon but also either a . or a [
+    // as IPv6 addresses specified as address:port are to be specified as "[addr:addr:...:addr]:port"
+    // One may also specify an IPv6 address as simply "[addr:addr:...:addr]" without the port; in that case
+    // the square braces will be stripped here.
+    if ((std::string::npos != colon_pos && std::string::npos != dot_pos) || std::string::npos != square_brace_pos)
     {
-      CHECK_AND_ASSERT_MES(addr.length() - 1 != pos && 0 != pos, false, "Failed to parse seed address from string: '" << addr << '\'');
+      net::get_network_address_host_and_port(addr, host, port);
-      host = addr.substr(0, pos);
-      port = addr.substr(pos + 1);
     }
     MINFO("Resolving node address: host=" << host << ", port=" << port);
 
@@ -546,7 +559,9 @@ namespace nodetool
       }
       else
       {
-        MWARNING("IPv6 unsupported, skip '" << host << "' -> " << endpoint.address().to_v6().to_string(ec));
+        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;
@@ -780,21 +795,40 @@ namespace nodetool
 
       if (!zone.second.m_bind_ip.empty())
       {
+        std::string ipv6_addr = "";
+        std::string ipv6_port = "";
         zone.second.m_net_server.set_connection_filter(this);
-        MINFO("Binding on " << zone.second.m_bind_ip << ":" << zone.second.m_port);
+        MINFO("Binding (IPv4) on " << zone.second.m_bind_ip << ":" << zone.second.m_port);
-        res = zone.second.m_net_server.init_server(zone.second.m_port, zone.second.m_bind_ip, epee::net_utils::ssl_support_t::e_ssl_support_disabled);
+        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 to " << public_zone.m_bind_ip << ":" << m_listening_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);
 
     // add UPnP port mapping
     if(m_igd == igd)
-      add_upnp_port_mapping(m_listening_port);
+    {
+      add_upnp_port_mapping_v4(m_listening_port);
+      if (m_use_ipv6)
+      {
+        add_upnp_port_mapping_v6(m_listening_port_ipv6);
+      }
+    }
 
     return res;
   }
@@ -1997,19 +2031,43 @@ namespace nodetool
     if(!node_data.my_port)
       return false;
 
-    CHECK_AND_ASSERT_MES(context.m_remote_address.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id(), 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());
-        "Only IPv4 addresses are supported here");
+    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;
-    uint32_t actual_ip = na.as<const epee::net_utils::ipv4_network_address>().ip();
+    std::string ip;
+    uint32_t ipv4_addr;
+    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 ip = epee::string_tools::get_ip_string_from_int32(actual_ip);
     std::string port = epee::string_tools::num_to_string_fast(node_data.my_port);
-    epee::net_utils::network_address address{epee::net_utils::ipv4_network_address(actual_ip, 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,
@@ -2193,12 +2251,19 @@ namespace nodetool
       //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(), void(),
+        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 addresses are supported here");
+            "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);
@@ -2565,16 +2630,19 @@ namespace nodetool
   }
 
   template<class t_payload_net_handler>
-  void node_server<t_payload_net_handler>::add_upnp_port_mapping(uint32_t port)
+  void node_server<t_payload_net_handler>::add_upnp_port_mapping_impl(uint32_t port, bool ipv6) // if ipv6 false, do ipv4
   {
-    MDEBUG("Attempting to add IGD port mapping.");
+    std::string ipversion = ipv6 ? "(IPv6)" : "(IPv4)";
+    MDEBUG("Attempting to add IGD port mapping " << ipversion << ".");
     int result;
+    const int ipv6_arg = ipv6 ? 1 : 0;
+
 #if MINIUPNPC_API_VERSION > 13
     // default according to miniupnpc.h
     unsigned char ttl = 2;
-    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, 0, ttl, &result);
+    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, ipv6_arg, ttl, &result);
 #else
-    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, 0, &result);
+    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, ipv6_arg, &result);
 #endif
     UPNPUrls urls;
     IGDdatas igdData;
@@ -2611,16 +2679,38 @@ namespace nodetool
   }
 
   template<class t_payload_net_handler>
-  void node_server<t_payload_net_handler>::delete_upnp_port_mapping(uint32_t port)
+  void node_server<t_payload_net_handler>::add_upnp_port_mapping_v4(uint32_t port)
   {
-    MDEBUG("Attempting to delete IGD port mapping.");
+    add_upnp_port_mapping_impl(port, false);
+  }
+
+  template<class t_payload_net_handler>
+  void node_server<t_payload_net_handler>::add_upnp_port_mapping_v6(uint32_t port)
+  {
+    add_upnp_port_mapping_impl(port, true);
+  }
+
+  template<class t_payload_net_handler>
+  void node_server<t_payload_net_handler>::add_upnp_port_mapping(uint32_t port, bool ipv4, bool ipv6)
+  {
+    if (ipv4) add_upnp_port_mapping_v4(port);
+    if (ipv6) add_upnp_port_mapping_v6(port);
+  }
+
+
+  template<class t_payload_net_handler>
+  void node_server<t_payload_net_handler>::delete_upnp_port_mapping_impl(uint32_t port, bool ipv6)
+  {
+    std::string ipversion = ipv6 ? "(IPv6)" : "(IPv4)";
+    MDEBUG("Attempting to delete IGD port mapping " << ipversion << ".");
     int result;
+    const int ipv6_arg = ipv6 ? 1 : 0;
 #if MINIUPNPC_API_VERSION > 13
     // default according to miniupnpc.h
     unsigned char ttl = 2;
-    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, 0, ttl, &result);
+    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, ipv6_arg, ttl, &result);
 #else
-    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, 0, &result);
+    UPNPDev* deviceList = upnpDiscover(1000, NULL, NULL, 0, ipv6_arg, &result);
 #endif
     UPNPUrls urls;
     IGDdatas igdData;
@@ -2653,6 +2743,25 @@ namespace nodetool
     }
   }
 
+  template<class t_payload_net_handler>
+  void node_server<t_payload_net_handler>::delete_upnp_port_mapping_v4(uint32_t port)
+  {
+    delete_upnp_port_mapping_impl(port, false);
+  }
+
+  template<class t_payload_net_handler>
+  void node_server<t_payload_net_handler>::delete_upnp_port_mapping_v6(uint32_t port)
+  {
+    delete_upnp_port_mapping_impl(port, true);
+  }
+
+  template<class t_payload_net_handler>
+  void node_server<t_payload_net_handler>::delete_upnp_port_mapping(uint32_t port)
+  {
+    delete_upnp_port_mapping_v4(port);
+    delete_upnp_port_mapping_v6(port);
+  }
+
   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)
@@ -2671,13 +2780,34 @@ namespace nodetool
   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)
   {
-    CHECK_AND_ASSERT_MES(na.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id(), boost::none,
+    bool is_ipv4 = na.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id();
-      "Only IPv4 addresses are supported here");
+    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(epee::string_tools::get_ip_string_from_int32(ipv4.ip()),
+    const bool res = zone.m_net_server.connect(address, port,
-      epee::string_tools::num_to_string_fast(ipv4.port()),
       zone.m_config.m_net_config.connection_timeout,
       con, "0.0.0.0", ssl_support);
 

src/p2p/net_peerlist_boost_serialization.h

@@ -76,6 +76,9 @@ namespace boost
         case epee::net_utils::ipv4_network_address::get_type_id():
           do_serialize<epee::net_utils::ipv4_network_address>(is_saving, a, na);
           break;
+        case epee::net_utils::ipv6_network_address::get_type_id():
+          do_serialize<epee::net_utils::ipv6_network_address>(is_saving, a, na);
+          break;
         case net::tor_address::get_type_id():
           do_serialize<net::tor_address>(is_saving, a, na);
           break;
@@ -98,6 +101,34 @@ namespace boost
         na = epee::net_utils::ipv4_network_address{ip, port};
     }
 
+    template <class Archive, class ver_type>
+    inline void serialize(Archive &a, boost::asio::ip::address_v6& v6, const ver_type ver)
+    {
+      if (typename Archive::is_saving())
+      {
+        auto bytes = v6.to_bytes();
+        for (auto &e: bytes) a & e;
+      }
+      else
+      {
+        boost::asio::ip::address_v6::bytes_type bytes;
+        for (auto &e: bytes) a & e;
+        v6 = boost::asio::ip::address_v6(bytes);
+      }
+    }
+
+    template <class Archive, class ver_type>
+    inline void serialize(Archive &a, epee::net_utils::ipv6_network_address& na, const ver_type ver)
+    {
+      boost::asio::ip::address_v6 ip{na.ip()};
+      uint16_t port{na.port()};
+      a & ip;
+      a & port;
+      if (!typename Archive::is_saving())
+        na = epee::net_utils::ipv6_network_address{ip, port};
+    }
+
+
     template <class Archive, class ver_type>
     inline void save(Archive& a, const net::tor_address& na, const ver_type)
     {

src/rpc/core_rpc_server.cpp

@@ -161,7 +161,9 @@ namespace cryptonote
 
     auto rng = [](size_t len, uint8_t *ptr){ return crypto::rand(len, ptr); };
     return epee::http_server_impl_base<core_rpc_server, connection_context>::init(
-      rng, std::move(port), std::move(rpc_config->bind_ip), std::move(rpc_config->access_control_origins), std::move(http_login), std::move(rpc_config->ssl_options)
+      rng, std::move(port), std::move(rpc_config->bind_ip),
+      std::move(rpc_config->bind_ipv6_address), std::move(rpc_config->use_ipv6), std::move(rpc_config->require_ipv4),
+      std::move(rpc_config->access_control_origins), std::move(http_login), std::move(rpc_config->ssl_options)
     );
   }
   //------------------------------------------------------------------------------------------------------------------------------
@@ -1026,6 +1028,11 @@ namespace cryptonote
       if (entry.adr.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id())
         res.white_list.emplace_back(entry.id, entry.adr.as<epee::net_utils::ipv4_network_address>().ip(),
             entry.adr.as<epee::net_utils::ipv4_network_address>().port(), entry.last_seen, entry.pruning_seed, entry.rpc_port);
+      else if (entry.adr.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id())
+      {
+        res.white_list.emplace_back(entry.id, entry.adr.as<epee::net_utils::ipv6_network_address>().host_str(),
+            entry.adr.as<epee::net_utils::ipv6_network_address>().port(), entry.last_seen, entry.pruning_seed, entry.rpc_port);
+      }
       else
         res.white_list.emplace_back(entry.id, entry.adr.str(), entry.last_seen, entry.pruning_seed, entry.rpc_port);
     }
@@ -1036,6 +1043,9 @@ namespace cryptonote
       if (entry.adr.get_type_id() == epee::net_utils::ipv4_network_address::get_type_id())
         res.gray_list.emplace_back(entry.id, entry.adr.as<epee::net_utils::ipv4_network_address>().ip(),
             entry.adr.as<epee::net_utils::ipv4_network_address>().port(), entry.last_seen, entry.pruning_seed, entry.rpc_port);
+      else if (entry.adr.get_type_id() == epee::net_utils::ipv6_network_address::get_type_id())
+        res.white_list.emplace_back(entry.id, entry.adr.as<epee::net_utils::ipv6_network_address>().host_str(),
+            entry.adr.as<epee::net_utils::ipv6_network_address>().port(), entry.last_seen, entry.pruning_seed, entry.rpc_port);
       else
         res.gray_list.emplace_back(entry.id, entry.adr.str(), entry.last_seen, entry.pruning_seed, entry.rpc_port);
     }

src/rpc/core_rpc_server_commands_defs.h

@@ -1200,6 +1200,9 @@ namespace cryptonote
     peer(uint64_t id, const std::string &host, uint64_t last_seen, uint32_t pruning_seed, uint16_t rpc_port)
       : id(id), host(host), ip(0), port(0), rpc_port(rpc_port), last_seen(last_seen), pruning_seed(pruning_seed)
     {}
+    peer(uint64_t id, const std::string &host, uint16_t port, uint64_t last_seen, uint32_t pruning_seed, uint16_t rpc_port)
+      : id(id), host(host), ip(0), port(port), rpc_port(rpc_port), last_seen(last_seen), pruning_seed(pruning_seed)
+    {}
     peer(uint64_t id, uint32_t ip, uint16_t port, uint64_t last_seen, uint32_t pruning_seed, uint16_t rpc_port)
       : id(id), host(epee::string_tools::get_ip_string_from_int32(ip)), ip(ip), port(port), rpc_port(rpc_port), last_seen(last_seen), pruning_seed(pruning_seed)
     {}

src/rpc/rpc_args.cpp

@@ -90,6 +90,9 @@ namespace cryptonote
 
   rpc_args::descriptors::descriptors()
      : rpc_bind_ip({"rpc-bind-ip", rpc_args::tr("Specify IP to bind RPC server"), "127.0.0.1"})
+     , rpc_bind_ipv6_address({"rpc-bind-ipv6-address", rpc_args::tr("Specify IPv6 address to bind RPC server"), "::1"})
+     , rpc_use_ipv6({"rpc-use-ipv6", rpc_args::tr("Allow IPv6 for RPC"), false})
+     , rpc_require_ipv4({"rpc-require-ipv4", rpc_args::tr("Require successful IPv4 bind for RPC"), true})
      , rpc_login({"rpc-login", rpc_args::tr("Specify username[:password] required for RPC server"), "", true})
      , confirm_external_bind({"confirm-external-bind", rpc_args::tr("Confirm rpc-bind-ip value is NOT a loopback (local) IP")})
      , rpc_access_control_origins({"rpc-access-control-origins", rpc_args::tr("Specify a comma separated list of origins to allow cross origin resource sharing"), ""})
@@ -108,6 +111,9 @@ namespace cryptonote
   {
     const descriptors arg{};
     command_line::add_arg(desc, arg.rpc_bind_ip);
+    command_line::add_arg(desc, arg.rpc_bind_ipv6_address);
+    command_line::add_arg(desc, arg.rpc_use_ipv6);
+    command_line::add_arg(desc, arg.rpc_require_ipv4);
     command_line::add_arg(desc, arg.rpc_login);
     command_line::add_arg(desc, arg.confirm_external_bind);
     command_line::add_arg(desc, arg.rpc_access_control_origins);
@@ -127,6 +133,9 @@ namespace cryptonote
     rpc_args config{};
     
     config.bind_ip = command_line::get_arg(vm, arg.rpc_bind_ip);
+    config.bind_ipv6_address = command_line::get_arg(vm, arg.rpc_bind_ipv6_address);
+    config.use_ipv6 = command_line::get_arg(vm, arg.rpc_use_ipv6);
+    config.require_ipv4 = command_line::get_arg(vm, arg.rpc_require_ipv4);
     if (!config.bind_ip.empty())
     {
       // always parse IP here for error consistency
@@ -148,6 +157,34 @@ namespace cryptonote
         return boost::none;
       }
     }
+    if (!config.bind_ipv6_address.empty())
+    {
+      // allow square braces, but remove them here if present
+      if (config.bind_ipv6_address.find('[') != std::string::npos)
+      {
+        config.bind_ipv6_address = config.bind_ipv6_address.substr(1, config.bind_ipv6_address.size() - 2);
+      }
+
+
+      // always parse IP here for error consistency
+      boost::system::error_code ec{};
+      const auto parsed_ip = boost::asio::ip::address::from_string(config.bind_ipv6_address, ec);
+      if (ec)
+      {
+        LOG_ERROR(tr("Invalid IP address given for --") << arg.rpc_bind_ipv6_address.name);
+        return boost::none;
+      }
+
+      if (!parsed_ip.is_loopback() && !command_line::get_arg(vm, arg.confirm_external_bind))
+      {
+        LOG_ERROR(
+          "--" << arg.rpc_bind_ipv6_address.name <<
+          tr(" permits inbound unencrypted external connections. Consider SSH tunnel or SSL proxy instead. Override with --") <<
+          arg.confirm_external_bind.name
+        );
+        return boost::none;
+      }
+    }
 
     const char *env_rpc_login = nullptr;
     const bool has_rpc_arg = command_line::has_arg(vm, arg.rpc_login);

src/rpc/rpc_args.h

@@ -52,6 +52,9 @@ namespace cryptonote
       descriptors& operator=(descriptors&&) = delete;
 
       const command_line::arg_descriptor<std::string> rpc_bind_ip;
+      const command_line::arg_descriptor<std::string> rpc_bind_ipv6_address;
+      const command_line::arg_descriptor<bool> rpc_use_ipv6;
+      const command_line::arg_descriptor<bool> rpc_require_ipv4;
       const command_line::arg_descriptor<std::string> rpc_login;
       const command_line::arg_descriptor<bool> confirm_external_bind;
       const command_line::arg_descriptor<std::string> rpc_access_control_origins;
@@ -76,6 +79,9 @@ namespace cryptonote
     static boost::optional<epee::net_utils::ssl_options_t> process_ssl(const boost::program_options::variables_map& vm, const bool any_cert_option = false);
 
     std::string bind_ip;
+    std::string bind_ipv6_address;
+    bool use_ipv6;
+    bool require_ipv4;
     std::vector<std::string> access_control_origins;
     boost::optional<tools::login> login; // currently `boost::none` if unspecified by user
     epee::net_utils::ssl_options_t ssl_options = epee::net_utils::ssl_support_t::e_ssl_support_enabled;

src/wallet/wallet_rpc_server.cpp

@@ -247,7 +247,9 @@ namespace tools
     m_net_server.set_threads_prefix("RPC");
     auto rng = [](size_t len, uint8_t *ptr) { return crypto::rand(len, ptr); };
     return epee::http_server_impl_base<wallet_rpc_server, connection_context>::init(
-      rng, std::move(bind_port), std::move(rpc_config->bind_ip), std::move(rpc_config->access_control_origins), std::move(http_login),
+      rng, std::move(bind_port), std::move(rpc_config->bind_ip),
+      std::move(rpc_config->bind_ipv6_address), std::move(rpc_config->use_ipv6), std::move(rpc_config->require_ipv4),
+      std::move(rpc_config->access_control_origins), std::move(http_login),
       std::move(rpc_config->ssl_options)
     );
   }