select introducers randomly. More logging for RelayIntro

libi2pd/SSU2.cpp

@@ -6,6 +6,7 @@
 * See full license text in LICENSE file at top of project tree
 */
 
+#include <random>
 #include "Log.h"
 #include "RouterContext.h"
 #include "Transports.h"
@@ -576,18 +577,27 @@ namespace transport
 		auto ts = i2p::util::GetSecondsSinceEpoch ();
 		std::shared_ptr<i2p::data::RouterInfo> r;
 		uint32_t relayTag = 0;
-		for (auto& it: address->ssu->introducers)
+		if (!address->ssu->introducers.empty ())
 		{	
-			if (it.iTag && ts < it.iExp)
+			std::vector<int> indicies;
+			for (int i = 0; i < (int)address->ssu->introducers.size (); i++) indicies.push_back(i);
+			if (indicies.size () > 1)
+				std::shuffle (indicies.begin(), indicies.end(), std::mt19937(std::random_device()()));
+
+			for (auto i: indicies)
 			{
-				r = i2p::data::netdb.FindRouter (it.iKey);
+				const auto& introducer = address->ssu->introducers[indicies[i]]; 
+				if (introducer.iTag && ts < introducer.iExp)
+				{	
+					r = i2p::data::netdb.FindRouter (introducer.iKey);
 					if (r && r->IsReachableFrom (i2p::context.GetRouterInfo ()))
 					{
-					relayTag = it.iTag;
+						relayTag = introducer.iTag;
 						if (relayTag) break;
 					}
 				}	
 			}
+		}	
 		if (r)
 		{
 			if (relayTag)

libi2pd/SSU2Session.cpp

@@ -1070,6 +1070,7 @@ namespace transport
 		const uint8_t * introKey, uint64_t token)
 	{
 		// we are Charlie
+		LogPrint (eLogDebug, "SSU2: Sending HolePunch to ", ep);
 		Header header;
 		uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE];
 		// fill packet
@@ -1641,11 +1642,14 @@ namespace transport
 							SendHolePunch (bufbe32toh (buf + 33), ep, addr->i, token);
 						}	
 						else
+						{	
+							LogPrint (eLogWarning, "SSU2: RelayIntro unsupported address");
 							code = eSSU2RelayResponseCodeCharlieUnsupportedAddress;
 						}	
+					}	
 					else
 					{
-						LogPrint (eLogWarning, "SSU2: RelayInfo unknown address");
+						LogPrint (eLogWarning, "SSU2: RelayIntro unknown address");
 						code = eSSU2RelayResponseCodeCharlieAliceIsUnknown;	
 					}		
 				}