From b29ec20ad46d5d4ce03aaa36bbc6e1d5be7748e7 Mon Sep 17 00:00:00 2001
From: Jeff Becker <jeff@i2p.rocks>
Date: Fri, 26 Jul 2019 12:19:08 -0400
Subject: [PATCH] try deferred resolve for exit handler

---
 llarp/handlers/exit.cpp | 26 ++++++++++++++++++++++----
 llarp/handlers/exit.hpp |  5 +++++
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/llarp/handlers/exit.cpp b/llarp/handlers/exit.cpp
index c371cacf7..137659fd0 100644
--- a/llarp/handlers/exit.cpp
+++ b/llarp/handlers/exit.cpp
@@ -171,10 +171,20 @@ namespace llarp
           }
           else if(m_SNodeKeys.find(pubKey) == m_SNodeKeys.end())
           {
-            // we do not have it mapped
-            // map it
-            ip = ObtainServiceNodeIP(r);
-            msg.AddINReply(ip, isV6);
+            // we do not have it mapped, async obtain it
+            ObtainSNodeSession(
+                r, [&](std::shared_ptr< exit::BaseSession > session) {
+                  if(session && session->IsReady())
+                  {
+                    msg.AddINReply(m_KeyToIP[pubKey], isV6);
+                  }
+                  else
+                  {
+                    msg.AddNXReply();
+                  }
+                  reply(msg);
+                });
+            return;
           }
           else
           {
@@ -196,6 +206,14 @@ namespace llarp
       return true;
     }
 
+    void
+    ExitEndpoint::ObtainSNodeSession(const RouterID &router,
+                                     exit::SessionReadyFunc obtainCb)
+    {
+      ObtainServiceNodeIP(router);
+      m_SNodeSessions[router]->AddReadyHook(obtainCb);
+    }
+
     llarp_time_t
     ExitEndpoint::Now() const
     {
diff --git a/llarp/handlers/exit.hpp b/llarp/handlers/exit.hpp
index e96409468..d8d6abbab 100644
--- a/llarp/handlers/exit.hpp
+++ b/llarp/handlers/exit.hpp
@@ -120,6 +120,11 @@ namespace llarp
       huint128_t
       ObtainServiceNodeIP(const RouterID& router);
 
+      /// async obtain snode session and call callback when it's ready to send
+      void
+      ObtainSNodeSession(const RouterID& router,
+                         exit::SessionReadyFunc obtainCb);
+
       bool
       QueueSNodePacket(const llarp_buffer_t& buf, huint128_t from);