detect our ipv6 address

libi2pd/NetDb.cpp

@@ -1076,6 +1076,15 @@ namespace data
 			});
 	}
 
+	std::shared_ptr<const RouterInfo> NetDb::GetRandomSSUV6Router () const
+	{
+		return GetRandomRouter (
+			[](std::shared_ptr<const RouterInfo> router)->bool
+			{
+				return !router->IsHidden () && router->IsSSUV6 ();
+			});
+	}		
+
 	std::shared_ptr<const RouterInfo> NetDb::GetRandomIntroducer () const
 	{
 		return GetRandomRouter (

libi2pd/NetDb.hpp

@@ -72,6 +72,7 @@ namespace data
 			std::shared_ptr<const RouterInfo> GetRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith) const;
 			std::shared_ptr<const RouterInfo> GetHighBandwidthRandomRouter (std::shared_ptr<const RouterInfo> compatibleWith) const;
 			std::shared_ptr<const RouterInfo> GetRandomPeerTestRouter (bool v4only = true) const;
+			std::shared_ptr<const RouterInfo> GetRandomSSUV6Router () const; // TODO: change to v6 peer test later
 			std::shared_ptr<const RouterInfo> GetRandomIntroducer () const;
 			std::shared_ptr<const RouterInfo> GetClosestFloodfill (const IdentHash& destination, const std::set<IdentHash>& excluded, bool closeThanUsOnly = false) const;
 			std::vector<IdentHash> GetClosestFloodfills (const IdentHash& destination, size_t num,

libi2pd/RouterInfo.cpp

@@ -808,6 +808,11 @@ namespace data
 			return m_SupportedTransports & (eSSUV4 | eSSUV6);
 	}
 
+	bool RouterInfo::IsSSUV6 () const
+	{
+		return m_SupportedTransports & eSSUV6;
+	}
+
 	bool RouterInfo::IsNTCP2 (bool v4only) const
 	{
 		if (v4only)

libi2pd/RouterInfo.h

@@ -161,6 +161,7 @@ namespace data
 			bool IsReachable () const { return m_Caps & Caps::eReachable; };
 			bool IsNTCP (bool v4only = true) const;
 			bool IsSSU (bool v4only = true) const;
+			bool IsSSUV6 () const;
 			bool IsNTCP2 (bool v4only = true) const;
 			bool IsV6 () const;
 			bool IsV4 () const;

libi2pd/Transports.cpp

@@ -552,6 +552,20 @@ namespace transport
 						m_SSUServer->CreateSession (router);		// no peer test
 				}
 			}
+			if (i2p::context.SupportsV6 ())
+			{
+				// try to connect to few v6 addresses to get our address back
+				for (int i = 0; i < 3; i++)
+				{
+					auto router = i2p::data::netdb.GetRandomSSUV6Router ();
+					if (router)
+					{
+						auto addr = router->GetSSUV6Address ();
+						if (addr)
+							m_SSUServer->CreateDirectSession (router, { addr->host, (uint16_t)addr->port }, false);
+					}
+				}
+			}
 		}
 		else
 			LogPrint (eLogError, "Transports: Can't detect external IP. SSU is not available");