more

docs/proto_v0.txt

@@ -656,6 +656,7 @@ start a new session
   A: "H",
   C: "<1048 bytes ciphertext block>",
   D: "<N bytes encrypted HSD>",
+  F: "<16 bytes source path_id>",
   N: "<32 bytes nonce for key exchange>",
   V: 0,
   Z: "<64 bytes signature of entire message using sender's signing key>"
@@ -691,6 +692,8 @@ C, K = PQKE_A(I_B.k)
 N = RAND(32)
 D = SE(X, K, N)
 
+path = PickSendPath()
+
 M = {
   A: "T",
   P: I_B.P,
@@ -699,6 +702,7 @@ M = {
     A: "H",
     C: C,
     D: D,
+    F: path.lastHop.txID,
     N: N,
     V: 0,
     Z: "\x00" * 64
@@ -711,6 +715,8 @@ Z = S(A_sk, BE(M))
 alice transmits a TDFM to router with public key I_B.K via her path that ends 
 with router with public key I_B.k
 
+path = PickSendPath()
+
 {
   A: "T",
   P: I_B.P,
@@ -719,6 +725,7 @@ with router with public key I_B.k
     A: "H",
     C: C,
     D: D,
+    F: path.lastHop.txID,
     N: N,
     V: 0,
     Z: Z
@@ -744,6 +751,7 @@ transfer data on a session previously made
 {
   A: "H",
   D: "<N bytes encrypted HSD>",
+  F: "<16 bytes path id of soruce>",
   N: "<32 bytes nonce for symettric cipher>",
   T: "<16 bytes converstation tag>",
   V: 0,

llarp/service/endpoint.cpp

@@ -998,6 +998,7 @@ namespace llarp
         if(!frame->Verify(Crypto(), si))
           return false;
         // remove convotag it doesn't exist
+        LogWarn("remove convotag T=", frame->T);
         RemoveConvoTag(frame->T);
         return true;
       }
@@ -1027,6 +1028,7 @@ namespace llarp
         , m_Endpoint(ep)
     {
       createdAt = ep->Now();
+      currentConvoTag.Zero();
     }
 
     void
@@ -1682,11 +1684,11 @@ namespace llarp
         path = m_Endpoint->GetPathByRouter(remoteIntro.router);
       if(path)
       {
-        routing::PathTransferMessage transfer(msg, remoteIntro.pathID);
+        const routing::PathTransferMessage transfer(msg, remoteIntro.pathID);
         if(path->SendRoutingMessage(&transfer, m_Endpoint->Router()))
         {
           llarp::LogDebug("sent data to ", remoteIntro.pathID, " on ",
-                          remoteIntro.router);
+                          remoteIntro.router, " seqno=", sequenceNo);
           lastGoodSend = m_Endpoint->Now();
           ++sequenceNo;
           return true;
@@ -1798,16 +1800,23 @@ namespace llarp
           ++itr;
       }
       // send control message if we look too quiet
-      if(now - lastGoodSend > (sendTimeout / 2))
+      if(lastGoodSend)
       {
-        if(!GetNewestPathByRouter(remoteIntro.router))
+        if(now - lastGoodSend > (sendTimeout / 2))
         {
-          BuildOneAlignedTo(remoteIntro.router);
+          if(!GetNewestPathByRouter(remoteIntro.router))
+          {
+            BuildOneAlignedTo(remoteIntro.router);
+          }
+          Encrypted< 64 > tmp;
+          tmp.Randomize();
+          llarp_buffer_t buf(tmp.data(), tmp.size());
+          AsyncEncryptAndSendTo(buf, eProtocolControl);
+          SharedSecret k;
+          if(currentConvoTag.IsZero())
+            return false;
+          return !m_DataHandler->HasConvoTag(currentConvoTag);
         }
-        Encrypted< 64 > tmp;
-        tmp.Randomize();
-        llarp_buffer_t buf(tmp.data(), tmp.size());
-        AsyncEncryptAndSendTo(buf, eProtocolControl);
       }
       // if we are dead return true so we are removed
       return lastGoodSend
@@ -1815,6 +1824,12 @@ namespace llarp
           : (now >= createdAt && now - createdAt > connectTimeout);
     }
 
+    bool
+    Endpoint::HasConvoTag(const ConvoTag& t) const
+    {
+      return m_Sessions.find(t) != m_Sessions.end();
+    }
+
     bool
     Endpoint::OutboundContext::SelectHop(llarp_nodedb* db,
                                          const RouterContact& prev,

llarp/service/endpoint.hpp

@@ -261,6 +261,9 @@ namespace llarp
       static void
       HandlePathDead(void*);
 
+      bool
+      HasConvoTag(const ConvoTag& t) const override;
+
       bool
       ShouldBuildMore(llarp_time_t now) const override;
 

llarp/service/handler.hpp

@@ -28,6 +28,9 @@ namespace llarp
       virtual void
       RemoveConvoTag(const ConvoTag& remote) = 0;
 
+      virtual bool
+      HasConvoTag(const ConvoTag& remote) const = 0;
+
       virtual void
       PutSenderFor(const ConvoTag& remote, const ServiceInfo& si) = 0;