From 87c0eabdb8063378389b10f73b2666f08a90b449 Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Wed, 15 May 2019 18:15:22 +0200
Subject: [PATCH] dnsdist: Extract TLS SNI for DoH if support is present

---
 pdns/dnsdistdist/doh.cc                         |  7 +++++++
 pdns/dnsdistdist/m4/pdns_check_libh2o_evloop.m4 | 13 +++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/pdns/dnsdistdist/doh.cc b/pdns/dnsdistdist/doh.cc
index 22c3765ca8..4e585d4afa 100644
--- a/pdns/dnsdistdist/doh.cc
+++ b/pdns/dnsdistdist/doh.cc
@@ -185,6 +185,13 @@ static int processDOHQuery(DOHUnit* du)
     dq.ednsAdded = du->ednsAdded;
     dq.du = du;
     queryId = ntohs(dh->id);
+#ifdef HAVE_H2O_SOCKET_GET_SSL_SERVER_NAME
+    h2o_socket_t* sock = du->req->conn->callbacks->get_socket(du->req->conn);
+    const char * sni = h2o_socket_get_ssl_server_name(sock);
+    if (sni != nullptr) {
+      dq.sni = sni;
+    }
+#endif /* HAVE_H2O_SOCKET_BET_SSL_SERVER_NAME */
 
     std::shared_ptr<DownstreamState> ss{nullptr};
     auto result = processQuery(dq, cs, holders, ss);
diff --git a/pdns/dnsdistdist/m4/pdns_check_libh2o_evloop.m4 b/pdns/dnsdistdist/m4/pdns_check_libh2o_evloop.m4
index ffe066b72f..00781ce32b 100644
--- a/pdns/dnsdistdist/m4/pdns_check_libh2o_evloop.m4
+++ b/pdns/dnsdistdist/m4/pdns_check_libh2o_evloop.m4
@@ -3,6 +3,19 @@ AC_DEFUN([PDNS_CHECK_LIBH2OEVLOOP], [
   PKG_CHECK_MODULES([LIBH2OEVLOOP], [libh2o-evloop], [
     [HAVE_LIBH2OEVLOOP=1]
     AC_DEFINE([HAVE_LIBH2OEVLOOP], [1], [Define to 1 if you have libh2o-evloop])
+    save_CFLAGS=$CFLAGS
+    save_LIBS=$LIBS
+    CFLAGS="$LIBH2OEVLOOP_CFLAGS $CFLAGS"
+    LIBS="$LIBH2OEVLOOP_LIBS $LIBS"
+    AC_CHECK_DECLS([h2o_socket_get_ssl_server_name], [
+          AC_DEFINE([HAVE_H2O_SOCKET_GET_SSL_SERVER_NAME], [1], [define to 1 if h2o_socket_get_ssl_server_name is available.])
+        ],
+        [ : ],
+        [AC_INCLUDES_DEFAULT
+          #include <h2o/socket.h>
+      ])
+    CFLAGS=$save_CFLAGS
+    LIBS=$save_LIBS
   ], [ : ])
   AM_CONDITIONAL([HAVE_LIBH2OEVLOOP], [test "x$LIBH2OEVLOOP_LIBS" != "x"])
 ])
-- 
2.47.2