From d5578666bcfb4f8c994e44a355bd786f232482e2 Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 15 Apr 2022 12:35:20 +0200
Subject: [PATCH] dnsdist: Use the correct outgoing protocol in our ring
 buffers

---
 pdns/dnsdist-tcp.cc     | 6 +++++-
 pdns/dnsdistdist/doh.cc | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/pdns/dnsdist-tcp.cc b/pdns/dnsdist-tcp.cc
index 57c079c4fa..e0de9f35e6 100644
--- a/pdns/dnsdist-tcp.cc
+++ b/pdns/dnsdist-tcp.cc
@@ -257,7 +257,11 @@ static void handleResponseSent(std::shared_ptr<IncomingTCPConnectionState>& stat
     double udiff = ids.sentTime.udiff();
     vinfolog("Got answer from %s, relayed to %s (%s, %d bytes), took %f usec", ds->d_config.remote.toStringWithPort(), ids.origRemote.toStringWithPort(), (state->d_handler.isTLS() ? "DoT" : "TCP"), currentResponse.d_buffer.size(), udiff);
 
-    ::handleResponseSent(ids, udiff, state->d_ci.remote, ds->d_config.remote, static_cast<unsigned int>(currentResponse.d_buffer.size()), currentResponse.d_cleartextDH, ds->getProtocol());
+    auto backendProtocol = ds->getProtocol();
+    if (backendProtocol == dnsdist::Protocol::DoUDP) {
+      backendProtocol = dnsdist::Protocol::DoTCP;
+    }
+    ::handleResponseSent(ids, udiff, state->d_ci.remote, ds->d_config.remote, static_cast<unsigned int>(currentResponse.d_buffer.size()), currentResponse.d_cleartextDH, backendProtocol);
 
     updateTCPLatency(ds, udiff);
   }
diff --git a/pdns/dnsdistdist/doh.cc b/pdns/dnsdistdist/doh.cc
index a03e842a2c..da1e8ef838 100644
--- a/pdns/dnsdistdist/doh.cc
+++ b/pdns/dnsdistdist/doh.cc
@@ -469,7 +469,11 @@ public:
     double udiff = du->ids.sentTime.udiff();
     vinfolog("Got answer from %s, relayed to %s (https), took %f usec", du->downstream->d_config.remote.toStringWithPort(), du->ids.origRemote.toStringWithPort(), udiff);
 
-    handleResponseSent(du->ids, udiff, *dr.remote, du->downstream->d_config.remote, du->response.size(), cleartextDH, du->downstream->getProtocol());
+    auto backendProtocol = du->downstream->getProtocol();
+    if (backendProtocol == dnsdist::Protocol::DoUDP && du->tcp) {
+      backendProtocol = dnsdist::Protocol::DoTCP;
+    }
+    handleResponseSent(du->ids, udiff, *dr.remote, du->downstream->d_config.remote, du->response.size(), cleartextDH, backendProtocol);
 
     ++g_stats.responses;
     if (du->ids.cs) {
-- 
2.47.2