From f49b5a3a0b655ca41579cba0d81d81bef44f97e8 Mon Sep 17 00:00:00 2001
From: Star Brilliant <coder@poorlab.com>
Date: Thu, 30 Nov 2017 16:14:05 +0800
Subject: [PATCH] Modify HTTP status codes to affect the error

---
 doh-client/client.go | 2 +-
 doh-server/server.go | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/doh-client/client.go b/doh-client/client.go
index acaf442..f9d4760 100644
--- a/doh-client/client.go
+++ b/doh-client/client.go
@@ -194,7 +194,7 @@ func (c *Client) handlerFunc(w dns.ResponseWriter, r *dns.Msg, isTCP bool) {
 		return
 	}
 	if resp.StatusCode != 200 {
-		log.Printf("Server returned error: %s\n", resp.Status)
+		log.Printf("HTTP error: %s\n", resp.Status)
 		reply.Rcode = dns.RcodeServerFailure
 		w.WriteMsg(reply)
 		return
diff --git a/doh-server/server.go b/doh-server/server.go
index 0bb664b..2b656b2 100644
--- a/doh-server/server.go
+++ b/doh-server/server.go
@@ -205,7 +205,7 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 
 	resp, err := s.doDNSQuery(msg)
 	if err != nil {
-		jsonDNS.FormatError(w, fmt.Sprintf("DNS query failure (%s)", err.Error()), 503)
+		jsonDNS.FormatError(w, fmt.Sprintf("DNS query failure (%s)", err.Error()), 502)
 		return
 	}
 	respJson := jsonDNS.Marshal(resp)
@@ -223,6 +223,9 @@ func (s *Server) handlerFunc(w http.ResponseWriter, r *http.Request) {
 		}
 		w.Header().Set("Expires", respJson.EarliestExpires.Format(time.RFC1123))
 	}
+	if respJson.Status == dns.RcodeServerFailure {
+		w.WriteHeader(503)
+	}
 	w.Write(respStr)
 }