track path data usage and don't kill paths when under heavy use

include/llarp/path.hpp

@@ -326,6 +326,9 @@ namespace llarp
       RouterID
       Endpoint() const;
 
+      bool
+      IsEndpoint(const RouterID& router, const PathID_t& path) const;
+
       const PathID_t&
       RXID() const;
 
@@ -343,6 +346,7 @@ namespace llarp
       DataHandlerFunc m_DataHandler;
       DropHandlerFunc m_DropHandler;
       CheckForDeadFunc m_CheckForDead;
+      llarp_time_t m_LastRecvMessage     = 0;
       llarp_time_t m_LastLatencyTestTime = 0;
       uint64_t m_LastLatencyTestID       = 0;
     };

include/llarp/service/Intro.hpp

@@ -63,7 +63,9 @@ namespace llarp
       bool
       operator<(const Introduction& other) const
       {
-        return expiresAt < other.expiresAt || pathID < other.pathID;
+        return expiresAt < other.expiresAt || pathID < other.pathID
+            || router < other.router || version < other.version
+            || latency < other.latency;
       }
 
       bool
@@ -79,6 +81,15 @@ namespace llarp
       {
         return !(*this == other);
       }
+
+      struct Hash
+      {
+        size_t
+        operator()(const Introduction& i) const
+        {
+          return *i.router.data_l() ^ *i.pathID.data_l();
+        }
+      };
     };
   }  // namespace service
 }  // namespace llarp

include/llarp/service/endpoint.hpp

@@ -194,8 +194,11 @@ namespace llarp
         ShiftIntroduction(){};
         virtual void
         UpdateIntroSet(){};
-        virtual void
-        MarkCurrentIntroBad(){};
+        virtual bool
+        MarkCurrentIntroBad(llarp_time_t now)
+        {
+          return true;
+        };
 
        private:
         void
@@ -227,14 +230,17 @@ namespace llarp
         ShiftIntroduction();
 
         /// mark the current remote intro as bad
-        void
-        MarkCurrentIntroBad();
+        bool
+        MarkCurrentIntroBad(llarp_time_t now);
 
         /// tick internal state
         /// return true to remove otherwise don't remove
         bool
         Tick(llarp_time_t now);
 
+        bool
+        CheckPathIsDead(path::Path* p, llarp_time_t dlt);
+
         void
         AsyncGenIntro(llarp_buffer_t payload, ProtocolType t);
 
@@ -264,7 +270,8 @@ namespace llarp
 
         uint64_t m_UpdateIntrosetTX = 0;
         IntroSet currentIntroSet;
-        std::set< Introduction > m_BadIntros;
+        std::unordered_map< Introduction, llarp_time_t, Introduction::Hash >
+            m_BadIntros;
         llarp_time_t lastShift = 0;
       };
 

llarp/path.cpp

@@ -427,7 +427,8 @@ namespace llarp
         SendRoutingMessage(&latency, r);
       }
       // check to see if this path is dead
-      if(_status == ePathEstablished)
+      if(_status == ePathEstablished
+         && (now > m_LastRecvMessage && now - m_LastRecvMessage > 1000))
       {
         if(m_CheckForDead)
         {
@@ -590,7 +591,13 @@ namespace llarp
     Path::HandleHiddenServiceFrame(const llarp::service::ProtocolFrame* frame)
     {
       if(m_DataHandler)
-        return m_DataHandler(this, frame);
+      {
+        if(m_DataHandler(this, frame))
+        {
+          m_LastRecvMessage = llarp_time_now_ms();
+          return true;
+        }
+      }
       return false;
     }
 

llarp/service/endpoint.cpp

@@ -722,8 +722,11 @@ namespace llarp
       {
         llarp::LogWarn(Name(), " message ", seq, " dropped by endpoint ",
                        p->Endpoint(), " via ", dst);
-        MarkCurrentIntroBad();
-        UpdateIntroSet();
+        if(MarkCurrentIntroBad(llarp_time_now_ms()))
+          llarp::LogInfo(Name(), " switched intros to ", remoteIntro.router,
+                         " via ", remoteIntro.pathID);
+        else
+          UpdateIntroSet();
       }
       return true;
     }
@@ -778,7 +781,7 @@ namespace llarp
     }
 
     bool
-    Endpoint::CheckPathIsDead(path::Path*, llarp_time_t latency)
+    Endpoint::CheckPathIsDead(path::Path* p, llarp_time_t latency)
     {
       if(latency >= m_MinPathLatency)
       {
@@ -985,32 +988,35 @@ namespace llarp
       return true;
     }  // namespace service
 
-    void
-    Endpoint::OutboundContext::MarkCurrentIntroBad()
+    bool
+    Endpoint::OutboundContext::MarkCurrentIntroBad(llarp_time_t now)
     {
-      auto now     = llarp_time_now_ms();
       bool shifted = false;
+      bool success = false;
       // insert bad intro
-      m_BadIntros.insert(remoteIntro);
+      m_BadIntros.insert(std::make_pair(remoteIntro, now));
       // shift off current intro
       for(const auto& intro : currentIntroSet.I)
       {
-        if(m_BadIntros.count(intro) == 0 && !intro.ExpiresSoon(now))
+        if(m_BadIntros.find(intro) == m_BadIntros.end()
+           && !intro.ExpiresSoon(now))
         {
           shifted     = intro.router != remoteIntro.router;
           remoteIntro = intro;
+          success     = true;
           break;
         }
       }
       // don't rebuild paths rapidly
       if(now - lastShift < MIN_SHIFT_INTERVAL)
-        return;
+        return success;
       // rebuild path if shifted
       if(shifted)
       {
         lastShift = now;
         ManualRebuild(1);
       }
+      return success;
     }
 
     void
@@ -1025,7 +1031,7 @@ namespace llarp
         m_Endpoint->EnsureRouterIsKnown(intro.router);
         if(intro.ExpiresSoon(now))
           continue;
-        if(m_BadIntros.count(intro) == 0 && remoteIntro != intro)
+        if(m_BadIntros.find(intro) == m_BadIntros.end() && remoteIntro != intro)
         {
           shifted     = intro.router != remoteIntro.router;
           remoteIntro = intro;
@@ -1172,7 +1178,10 @@ namespace llarp
         auto now = llarp_time_now_ms();
         if(remoteIntro.ExpiresSoon(now))
         {
-          MarkCurrentIntroBad();
+          if(!MarkCurrentIntroBad(now))
+          {
+            llarp::LogWarn("no good path yet, your message may drop");
+          }
         }
         routing::PathTransferMessage transfer(msg, remoteIntro.pathID);
         if(!path->SendRoutingMessage(&transfer, m_Endpoint->Router()))
@@ -1220,13 +1229,17 @@ namespace llarp
     {
       if(remoteIntro.ExpiresSoon(now))
       {
-        MarkCurrentIntroBad();
+        if(!MarkCurrentIntroBad(now))
+        {
+          // TODO: log?
+        }
       }
-      m_Endpoint->EnsureRouterIsKnown(remoteIntro.router);
+      if(!remoteIntro.router.IsZero())
+        m_Endpoint->EnsureRouterIsKnown(remoteIntro.router);
       auto itr = m_BadIntros.begin();
       while(itr != m_BadIntros.end())
       {
-        if(itr->IsExpired(now))
+        if(now - itr->second > DEFAULT_PATH_LIFETIME)
           itr = m_BadIntros.erase(itr);
         else
           ++itr;
@@ -1294,7 +1307,11 @@ namespace llarp
       if(remoteIntro.ExpiresSoon(now))
       {
         // shift intro
-        MarkCurrentIntroBad();
+        if(!MarkCurrentIntroBad(now))
+        {
+          llarp::LogError("dropping message, no path after shifting intros");
+          return;
+        }
       }
 
       auto path = m_PathSet->GetNewestPathByRouter(remoteIntro.router);