Do not respond to network error, silently fail to prevent caching of …

…SERVFAIL Hopefully we can improve the availability of DoH under unstable network environments.
m13253 · Apr 26, 2018 · c4b2236 · c4b2236
1 parent 1b90731
commit c4b2236
Show file tree

Hide file tree

Showing 4 changed files with 11 additions and 9 deletions.
diff --git a/doh-client/doh-client.conf b/doh-client/doh-client.conf
@@ -47,7 +47,7 @@ bootstrap = [
 ]
 
 # Timeout for upstream request
-timeout = 10
+timeout = 30
 
 # Disable HTTP Cookies
 #

diff --git a/doh-client/ietf.go b/doh-client/ietf.go
@@ -134,19 +134,17 @@ func (c *Client) generateRequestIETF(w dns.ResponseWriter, r *dns.Msg, isTCP boo
 	if len(requestURL) < 2048 {
 		req, err = http.NewRequest("GET", requestURL, nil)
 		if err != nil {
+			// Do not respond, silently fail to prevent caching of SERVFAIL
 			log.Println(err)
-			reply.Rcode = dns.RcodeServerFailure
-			w.WriteMsg(reply)
 			return &DNSRequest{
 				err: err,
 			}
 		}
 	} else {
 		req, err = http.NewRequest("POST", upstream, bytes.NewReader(requestBinary))
 		if err != nil {
+			// Do not respond, silently fail to prevent caching of SERVFAIL
 			log.Println(err)
-			reply.Rcode = dns.RcodeServerFailure
-			w.WriteMsg(reply)
 			return &DNSRequest{
 				err: err,
 			}

diff --git a/doh-client/version.go b/doh-client/version.go
@@ -23,5 +23,7 @@
 
 package main
 
-const VERSION = "1.3.3"
-const USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+const (
+	VERSION    = "1.3.3"
+	USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+)
diff --git a/doh-server/version.go b/doh-server/version.go
@@ -23,5 +23,7 @@
 
 package main
 
-const VERSION = "1.3.3"
-const USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+const (
+	VERSION    = "1.3.3"
+	USER_AGENT = "DNS-over-HTTPS/" + VERSION + " (+https://github.com/m13253/dns-over-https)"
+)