From 457b64f92dbbce9974453da71fc5af2802a4292f Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Fri, 14 Jun 2024 18:05:01 -0400
Subject: [PATCH] try to connect to introducer through any available address

---
 libi2pd/RouterInfo.cpp |  7 ++++++-
 libi2pd/RouterInfo.h   |  1 +
 libi2pd/SSU2.cpp       | 26 ++++++++++++++++++++++----
 3 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/libi2pd/RouterInfo.cpp b/libi2pd/RouterInfo.cpp
index 13fd2e17..56281de7 100644
--- a/libi2pd/RouterInfo.cpp
+++ b/libi2pd/RouterInfo.cpp
@@ -1022,9 +1022,14 @@ namespace data
 	bool RouterInfo::IsPublished (bool v4) const
 	{
 		if (m_Caps & (eUnreachable | eHidden)) return false; // if router sets U or H we assume that all addresses are not published
-		return m_PublishedTransports & (v4 ? (eNTCP2V4 | eSSU2V4) : (eNTCP2V6 | eSSU2V6));
+		return IsPublishedOn (v4 ? (eNTCP2V4 | eSSU2V4) : (eNTCP2V6 | eSSU2V6));
 	}	
 
+	bool RouterInfo::IsPublishedOn (CompatibleTransports transports) const
+	{
+		return m_PublishedTransports & transports;
+	}
+	
 	bool RouterInfo::IsNAT2NATOnly (const RouterInfo& other) const
 	{
 		return !(m_PublishedTransports & other.m_SupportedTransports) &&
diff --git a/libi2pd/RouterInfo.h b/libi2pd/RouterInfo.h
index 412c815e..cff5515e 100644
--- a/libi2pd/RouterInfo.h
+++ b/libi2pd/RouterInfo.h
@@ -264,6 +264,7 @@ namespace data
 			bool IsEligibleFloodfill () const;
 			bool IsDeclaredFloodfill () const { return m_Caps & RouterInfo::eFloodfill; };
 			bool IsPublished (bool v4) const;
+			bool IsPublishedOn (CompatibleTransports transports) const;
 			bool IsNAT2NATOnly (const RouterInfo& other) const; // only NAT-to-NAT connection is possible
 			bool IsSSU2PeerTesting (bool v4) const;
 			bool IsSSU2Introducer (bool v4) const;
diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp
index ab1a7d8b..41707b15 100644
--- a/libi2pd/SSU2.cpp
+++ b/libi2pd/SSU2.cpp
@@ -810,7 +810,8 @@ namespace transport
 				r = i2p::data::netdb.FindRouter (introducer.iH);
 				if (r)
 				{	
-					if (r->IsReachableFrom (i2p::context.GetRouterInfo ()))
+					if (r->IsPublishedOn (i2p::context.GetRouterInfo ().GetCompatibleTransports (false) & // outgoing
+					    (i2p::data::RouterInfo::eSSU2V4 | i2p::data::RouterInfo::eSSU2V6)))                  
 					{
 						relayTag = introducer.iTag;
 						addr = address->IsV6 () ? r->GetSSU2V6Address () : r->GetSSU2V4Address ();
@@ -819,9 +820,26 @@ namespace transport
 							break;
 						else
 						{
-							// address is invalid, try next introducer
-							relayTag = 0;
-							addr = nullptr;
+							// address is invalid try another SSU2 address if exists
+							if (address->IsV4 ())
+							{
+								if (i2p::context.SupportsV6 ())
+									addr = r->GetSSU2V6Address ();
+							}	
+							else
+							{
+								if (i2p::context.SupportsV4 ())
+									addr = r->GetSSU2V4Address ();
+							}	
+							if (addr && !addr->host.is_unspecified () && addr->port &&
+								!i2p::transport::transports.IsInReservedRange(addr->host))
+								break;
+							else
+							{	
+								// all addresses are invalid, try next introducer
+								relayTag = 0;
+								addr = nullptr;
+							}	
 						}	
 					}
 				}