fix dumb as shit path building that causes premature termiantion because of duplicate hops

llarp/exit/session.cpp

@@ -67,6 +67,11 @@ namespace llarp
       {
         return db->Get(m_ExitRouter, cur);
       }
+      else if(hop == numHops - 2)
+      {
+        return db->select_random_hop_excluding(cur,
+                                               {prev.pubkey, m_ExitRouter});
+      }
       else
         return path::Builder::SelectHop(db, prev, cur, hop, roles);
     }

llarp/link/utp.cpp

@@ -228,6 +228,8 @@ namespace llarp
     bool
     Session::IsTimedOut(llarp_time_t now) const
     {
+      if(state == eConnecting)
+        return false;
       if(state == eClose)
         return true;
       if(now <= lastActive)

llarp/nodedb.cpp

@@ -468,3 +468,47 @@ llarp_nodedb::select_random_hop(const llarp::RouterContact &prev,
   }
   return false;
 }
+
+bool
+llarp_nodedb::select_random_hop_excluding(
+    llarp::RouterContact &result, const std::set< llarp::RouterID > &exclude)
+{
+  llarp::util::Lock lock(&access);
+  /// checking for "guard" status for N = 0 is done by caller inside of
+  /// pathbuilder's scope
+  size_t sz = entries.size();
+  if(sz < 3)
+    return false;
+  llarp_time_t now = llarp::time_now_ms();
+
+  auto itr   = entries.begin();
+  size_t pos = llarp::randint() % sz;
+  std::advance(itr, pos);
+  auto start = itr;
+  while(itr == entries.end())
+  {
+    if(exclude.count(itr->first) == 0)
+    {
+      if(itr->second.addrs.size() && !itr->second.IsExpired(now))
+      {
+        result = itr->second;
+        return true;
+      }
+    }
+    itr++;
+  }
+  itr = entries.begin();
+  while(itr != start)
+  {
+    if(exclude.count(itr->first) == 0)
+    {
+      if(itr->second.addrs.size() && !itr->second.IsExpired(now))
+      {
+        result = itr->second;
+        return true;
+      }
+    }
+    ++itr;
+  }
+  return false;
+}

llarp/nodedb.hpp

@@ -9,6 +9,8 @@
 
 #include <absl/base/thread_annotations.h>
 
+#include <set>
+
 /**
  * nodedb.hpp
  *
@@ -113,6 +115,11 @@ struct llarp_nodedb
                     llarp::RouterContact &result, size_t N)
       LOCKS_EXCLUDED(access);
 
+  bool
+  select_random_hop_excluding(llarp::RouterContact &result,
+                              const std::set< llarp::RouterID > &exclude)
+      LOCKS_EXCLUDED(access);
+
   static bool
   ensure_dir(const char *dir);
 };

llarp/path/path.cpp

@@ -450,6 +450,15 @@ namespace llarp
       return hops[0].rc.pubkey;
     }
 
+    std::string
+    Path::HopsString() const
+    {
+      std::stringstream ss;
+      for(const auto& hop : hops)
+        ss << RouterID(hop.rc.pubkey) << " -> ";
+      return ss.str();
+    }
+
     void
     Path::EnterState(PathStatus st, llarp_time_t now)
     {

llarp/path/path.hpp

@@ -362,6 +362,9 @@ namespace llarp
         return _status;
       }
 
+      std::string
+      HopsString() const;
+
       llarp_time_t
       LastRemoteActivityAt() const override
       {

llarp/path/pathbuilder.cpp

@@ -213,11 +213,15 @@ namespace llarp
       size_t tries = 10;
       do
       {
+        cur.Clear();
         --tries;
         if(db->select_random_hop(prev, cur, hop))
-          return true;
-      } while(router->routerProfiling().IsBad(cur.pubkey) && tries > 0);
-      return false;
+        {
+          if(!router->routerProfiling().IsBad(cur.pubkey))
+            return true;
+        }
+      } while(tries > 0);
+      return tries > 0;
     }
 
     bool

llarp/path/pathset.cpp

@@ -292,7 +292,7 @@ namespace llarp
     void
     PathSet::HandlePathBuildTimeout(Path* p)
     {
-      LogInfo("path build for ", p->Name(), " has timed out");
+      LogInfo("path build ", p->HopsString(), " timed out");
     }
 
     bool

llarp/profiling.cpp

@@ -70,7 +70,7 @@ namespace llarp
   bool
   RouterProfile::IsGood(uint64_t chances) const
   {
-    if(connectTimeoutCount > 3)
+    if(connectTimeoutCount > chances)
       return connectTimeoutCount <= connectGoodCount
           && (pathSuccessCount * chances) >= pathFailCount;
     else

llarp/router_contact.hpp

@@ -131,6 +131,12 @@ namespace llarp
           && netID == other.netID;
     }
 
+    bool
+    operator<(const RouterContact &other) const
+    {
+      return pubkey < other.pubkey;
+    }
+
     bool
     operator!=(const RouterContact &other) const
     {

llarp/service/endpoint.cpp

@@ -1854,6 +1854,11 @@ namespace llarp
           return false;
         }
       }
+      else if(hop == numHops - 2)
+      {
+        return db->select_random_hop_excluding(
+            cur, {prev.pubkey, m_NextIntro.router});
+      }
       (void)roles;
       return path::Builder::SelectHop(db, prev, cur, hop, roles);
     }