add ifname4 and ifname6 options

Config.cpp

@@ -41,6 +41,8 @@ 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")
       ("ifname",    value<std::string>()->default_value(""), "Network interface to bind to")
+			("ifname4",   value<std::string>()->default_value(""), "Network interface to bind to for ipv4")
+			("ifname6",   value<std::string>()->default_value(""), "Network interface to bind to for ipv6")
       ("nat",       value<bool>()->zero_tokens()->default_value(true), "Should we assume we are behind NAT?")
       ("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")

RouterContext.cpp

@@ -74,6 +74,22 @@ namespace i2p
 			routerInfo.AddSSUAddress (host.c_str(), port, routerInfo.GetIdentHash ());
 			routerInfo.AddNTCPAddress (host.c_str(), port);
 		}
+
+		std::string ifname4; i2p::config::GetOption("ifname4", ifname4);
+		if(ifname4.size())
+		{
+			std::string host = i2p::util::net::GetInterfaceAddress(ifname4, false).to_string();
+			routerInfo.AddSSUAddress (host.c_str(), port, routerInfo.GetIdentHash());
+			routerInfo.AddNTCPAddress (host.c_str(), port);
+		}
+		std::string ifname6; i2p::config::GetOption("ifname6", ifname6);
+		if (ifname6.size())
+		{
+			std::string host = i2p::util::net::GetInterfaceAddress(ifname6, true).to_string();
+			routerInfo.AddSSUAddress (host.c_str(), port, routerInfo.GetIdentHash());
+			routerInfo.AddNTCPAddress (host.c_str(), port);	
+		}
+		
 		routerInfo.SetCaps (i2p::data::RouterInfo::eReachable | 
 			i2p::data::RouterInfo::eSSUTesting | i2p::data::RouterInfo::eSSUIntroducer); // LR, BC
         routerInfo.SetProperty ("netId", std::to_string (m_NetID));