From 697ece64cccbb8e154a4a3fa1796e2fbf0c33b08 Mon Sep 17 00:00:00 2001
From: Thomas Winget <tewinget@gmail.com>
Date: Thu, 25 Jul 2019 19:54:10 -0400
Subject: [PATCH] make TransitHop self-destruct if path is invalidated

---
 llarp/messages/relay_status.cpp | 16 +++++-----------
 llarp/path/transit_hop.cpp      | 26 ++++++++++++++++++++++++--
 llarp/path/transit_hop.hpp      |  9 +++++++++
 3 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/llarp/messages/relay_status.cpp b/llarp/messages/relay_status.cpp
index 813523394..68aa51380 100644
--- a/llarp/messages/relay_status.cpp
+++ b/llarp/messages/relay_status.cpp
@@ -21,19 +21,14 @@ namespace llarp
     using HopHandler_ptr = std::shared_ptr< llarp::path::IHopHandler >;
 
     std::array< EncryptedFrame, 8 > frames;
-    PathID_t pathid;
     uint64_t status = 0;
     HopHandler_ptr path;
     AbstractRouter* router;
 
     LRSM_AsyncHandler(const std::array< EncryptedFrame, 8 >& _frames,
-                      const PathID_t& _pathid, uint64_t _status,
-                      HopHandler_ptr _path, AbstractRouter* _router)
-        : frames(_frames)
-        , pathid(_pathid)
-        , status(_status)
-        , path(_path)
-        , router(_router)
+                      uint64_t _status, HopHandler_ptr _path,
+                      AbstractRouter* _router)
+        : frames(_frames), status(_status), path(_path), router(_router)
     {
     }
 
@@ -139,9 +134,8 @@ namespace llarp
       return false;
     }
 
-    const uint64_t ourStatus = LR_StatusRecord::SUCCESS;
-    auto handler             = std::make_shared< LRSM_AsyncHandler >(
-        frames, pathid, ourStatus, path, router);
+    auto handler =
+        std::make_shared< LRSM_AsyncHandler >(frames, status, path, router);
 
     handler->queue_handle();
 
diff --git a/llarp/path/transit_hop.cpp b/llarp/path/transit_hop.cpp
index f8f96e579..f2a1d3bc3 100644
--- a/llarp/path/transit_hop.cpp
+++ b/llarp/path/transit_hop.cpp
@@ -38,7 +38,7 @@ namespace llarp
     bool
     TransitHop::Expired(llarp_time_t now) const
     {
-      return now >= ExpireTime();
+      return destroy || (now >= ExpireTime());
     }
 
     llarp_time_t
@@ -58,13 +58,22 @@ namespace llarp
 
       // TODO: add to IHopHandler some notion of "path status"
 
-      if(!msg->AddFrame(pathKey, status))
+      const uint64_t ourStatus = LR_StatusRecord::SUCCESS;
+      if(!msg->AddFrame(pathKey, ourStatus))
       {
         return false;
       }
 
       LR_StatusMessage::QueueSendMessage(r, info.downstream, msg);
 
+      if((status & LR_StatusRecord::SUCCESS) == 0)
+      {
+        LogDebug(
+            "TransitHop received non-successful LR_StatusMessage, queueing "
+            "self-destruct");
+        QueueDestroySelf(r);
+      }
+
       return true;
     }
 
@@ -347,5 +356,18 @@ namespace llarp
 
       return stream;
     }
+
+    void
+    TransitHop::SetSelfDestruct()
+    {
+      destroy = true;
+    }
+
+    void
+    TransitHop::QueueDestroySelf(AbstractRouter* r)
+    {
+      auto func = std::bind(&TransitHop::SetSelfDestruct, this);
+      r->logic()->queue_func(func);
+    }
   }  // namespace path
 }  // namespace llarp
diff --git a/llarp/path/transit_hop.hpp b/llarp/path/transit_hop.hpp
index cd75aa95f..eb958eb50 100644
--- a/llarp/path/transit_hop.hpp
+++ b/llarp/path/transit_hop.hpp
@@ -92,6 +92,8 @@ namespace llarp
       llarp_proto_version_t version;
       llarp_time_t m_LastActivity = 0;
 
+      bool destroy = false;
+
       bool
       IsEndpoint(const RouterID& us) const
       {
@@ -200,6 +202,13 @@ namespace llarp
       bool
       HandleDownstream(const llarp_buffer_t& X, const TunnelNonce& Y,
                        AbstractRouter* r) override;
+
+     private:
+      void
+      SetSelfDestruct();
+
+      void
+      QueueDestroySelf(AbstractRouter* r);
     };
 
     inline std::ostream&