From 874a3613e4b7bb2488bce19643b9427d460b6924 Mon Sep 17 00:00:00 2001
From: Star Brilliant <coder@poorlab.com>
Date: Wed, 25 Apr 2018 03:04:31 +0800
Subject: [PATCH] Use dns.DefaultMsgSize instead of magic number 4096

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

diff --git a/doh-client/client.go b/doh-client/client.go
index 4ea9844..4b36c43 100644
--- a/doh-client/client.go
+++ b/doh-client/client.go
@@ -72,7 +72,7 @@ func NewClient(conf *config) (c *Client, err error) {
 			Addr:    addr,
 			Net:     "udp",
 			Handler: udpHandler,
-			UDPSize: 4096,
+			UDPSize: dns.DefaultMsgSize,
 		})
 		c.tcpServers = append(c.tcpServers, &dns.Server{
 			Addr:    addr,
diff --git a/doh-client/ietf.go b/doh-client/ietf.go
index b851441..6ba7a1a 100644
--- a/doh-client/ietf.go
+++ b/doh-client/ietf.go
@@ -73,7 +73,7 @@ func (c *Client) generateRequestIETF(w dns.ResponseWriter, r *dns.Msg, isTCP boo
 		opt = new(dns.OPT)
 		opt.Hdr.Name = "."
 		opt.Hdr.Rrtype = dns.TypeOPT
-		opt.SetUDPSize(4096)
+		opt.SetUDPSize(dns.DefaultMsgSize)
 		opt.SetDo(false)
 		r.Extra = append(r.Extra, opt)
 	} else {
diff --git a/doh-server/google.go b/doh-server/google.go
index c71c53e..3fbc927 100644
--- a/doh-server/google.go
+++ b/doh-server/google.go
@@ -150,7 +150,7 @@ func (s *Server) parseRequestGoogle(w http.ResponseWriter, r *http.Request) *DNS
 	opt := new(dns.OPT)
 	opt.Hdr.Name = "."
 	opt.Hdr.Rrtype = dns.TypeOPT
-	opt.SetUDPSize(4096)
+	opt.SetUDPSize(dns.DefaultMsgSize)
 	opt.SetDo(true)
 	if ednsClientAddress != nil {
 		edns0Subnet := new(dns.EDNS0_SUBNET)
diff --git a/doh-server/ietf.go b/doh-server/ietf.go
index a447ec4..60b43e4 100644
--- a/doh-server/ietf.go
+++ b/doh-server/ietf.go
@@ -93,7 +93,7 @@ func (s *Server) parseRequestIETF(w http.ResponseWriter, r *http.Request) *DNSRe
 		opt = new(dns.OPT)
 		opt.Hdr.Name = "."
 		opt.Hdr.Rrtype = dns.TypeOPT
-		opt.SetUDPSize(4096)
+		opt.SetUDPSize(dns.DefaultMsgSize)
 		opt.SetDo(false)
 		msg.Extra = append(msg.Extra, opt)
 	}
diff --git a/doh-server/server.go b/doh-server/server.go
index 12bc3f6..6197352 100644
--- a/doh-server/server.go
+++ b/doh-server/server.go
@@ -58,7 +58,7 @@ func NewServer(conf *config) (s *Server) {
 		conf: conf,
 		udpClient: &dns.Client{
 			Net:     "udp",
-			UDPSize: 4096,
+			UDPSize: dns.DefaultMsgSize,
 			Timeout: time.Duration(conf.Timeout) * time.Second,
 		},
 		tcpClient: &dns.Client{