add no ipv4 option in config

Config.cpp

@@ -117,6 +117,7 @@ namespace config {
 	  ("datadir",   value<std::string>()->default_value(""),     "Path to storage of i2pd data (RI, keys, peer profiles, ...)")
       ("host",      value<std::string>()->default_value("0.0.0.0"),     "External IP")
       ("port",      value<uint16_t>()->default_value(0),                "Port to listen for incoming connections (default: auto)")
+      ("ipv4",      value<bool>()->zero_tokens()->default_value(true),  "Enable communication through ipv4")
       ("ipv6",      value<bool>()->zero_tokens()->default_value(false), "Enable communication through ipv6")
       ("daemon",    value<bool>()->zero_tokens()->default_value(false), "Router will go to background after start")
       ("service",   value<bool>()->zero_tokens()->default_value(false), "Router will use system folders like '/var/lib/i2pd'")

Daemon.cpp

@@ -104,9 +104,11 @@ namespace i2p
 				i2p::context.UpdateAddress (boost::asio::ip::address::from_string (host));	
 			}
 
-			bool ipv6;    i2p::config::GetOption("ipv6", ipv6);
+			bool ipv6;		i2p::config::GetOption("ipv6", ipv6);
+			bool ipv4;		i2p::config::GetOption("ipv4", ipv4);
 			bool transit; i2p::config::GetOption("notransit", transit);
-			i2p::context.SetSupportsV6     (ipv6);
+			i2p::context.SetSupportsV6		 (ipv6);
+			i2p::context.SetSupportsV4		 (ipv4);
 			i2p::context.SetAcceptsTunnels (!transit);
 
 			bool isFloodfill; i2p::config::GetOption("floodfill", isFloodfill);

RouterContext.cpp

@@ -257,7 +257,17 @@ namespace i2p
 		else
 			m_RouterInfo.DisableV6 ();
 		UpdateRouterInfo ();
-	}	
+	}
+  	
+	void RouterContext::SetSupportsV4 (bool supportsV4)
+	{
+		if (supportsV4)
+			m_RouterInfo.EnableV4 ();
+		else
+			m_RouterInfo.DisableV4 ();
+		UpdateRouterInfo ();
+	}
+  
 
 	void RouterContext::UpdateNTCPV6Address (const boost::asio::ip::address& host)
 	{

RouterContext.h

@@ -64,7 +64,10 @@ namespace i2p
 			bool AcceptsTunnels () const { return m_AcceptsTunnels; };
 			void SetAcceptsTunnels (bool acceptsTunnels) { m_AcceptsTunnels = acceptsTunnels; };
 			bool SupportsV6 () const { return m_RouterInfo.IsV6 (); };
+			bool SupportsV4 () const { return m_RouterInfo.IsV4 (); };
 			void SetSupportsV6 (bool supportsV6);
+			void SetSupportsV4 (bool supportsV4);
+
 			void UpdateNTCPV6Address (const boost::asio::ip::address& host); // called from NTCP session		
 			void UpdateStats ();		
 

RouterInfo.cpp

@@ -651,12 +651,24 @@ namespace data
 		return m_SupportedTransports & (eNTCPV6 | eSSUV6);
 	}
 
+	bool RouterInfo::IsV4 () const
+	{
+		return m_SupportedTransports & (eNTCPV4 | eSSUV4);
+	}
+	
 	void RouterInfo::EnableV6 ()
 	{
 		if (!IsV6 ())
 			m_SupportedTransports |= eNTCPV6 | eSSUV6;
 	}
-		
+
+  void RouterInfo::EnableV4 ()
+	{
+		if (!IsV4 ())
+			m_SupportedTransports |= eNTCPV4 | eSSUV4;
+	}
+	
+  
 	void RouterInfo::DisableV6 ()
 	{		
 		if (IsV6 ())
@@ -686,7 +698,38 @@ namespace data
 			}	
 		}	
 	}
-		
+
+  void RouterInfo::DisableV4 ()
+	{		
+		if (IsV4 ())
+		{	
+			// NTCP
+			m_SupportedTransports &= ~eNTCPV4; 
+			for (size_t i = 0; i < m_Addresses.size (); i++)
+			{
+				if (m_Addresses[i]->transportStyle == i2p::data::RouterInfo::eTransportNTCP &&
+					m_Addresses[i]->host.is_v4 ())
+				{
+					m_Addresses.erase (m_Addresses.begin () + i);
+					break;
+				}
+			}	
+			
+			// SSU
+			m_SupportedTransports &= ~eSSUV4; 
+			for (size_t i = 0; i < m_Addresses.size (); i++)
+			{
+				if (m_Addresses[i]->transportStyle == i2p::data::RouterInfo::eTransportSSU &&
+					m_Addresses[i]->host.is_v4 ())
+				{
+					m_Addresses.erase (m_Addresses.begin () + i);
+					break;
+				}
+			}	
+		}	
+	}
+	
+  
 	bool RouterInfo::UsesIntroducer () const
 	{
 		return m_Caps & Caps::eUnreachable; // non-reachable

RouterInfo.h

@@ -133,8 +133,11 @@ namespace data
 			bool IsNTCP (bool v4only = true) const;
 			bool IsSSU (bool v4only = true) const;
 			bool IsV6 () const;
+			bool IsV4 () const;
 			void EnableV6 ();
 			void DisableV6 ();
+			void EnableV4 ();
+			void DisableV4 ();
 			bool IsCompatible (const RouterInfo& other) const { return m_SupportedTransports & other.m_SupportedTransports; };
 			bool UsesIntroducer () const;
 			bool IsIntroducer () const { return m_Caps & eSSUIntroducer; };