From 913ddc5081a78e0d2f5262162e7bf96523bea68c Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 6 Oct 2019 17:49:49 +0200
Subject: [PATCH] add a quic.Config option for DATAGRAM frames

---
 client_test.go | 2 ++
 config.go      | 1 +
 config_test.go | 2 ++
 interface.go   | 5 ++++-
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/client_test.go b/client_test.go
index bbdf35f5..6004e64e 100644
--- a/client_test.go
+++ b/client_test.go
@@ -465,6 +465,7 @@ var _ = Describe("Client", func() {
 					ConnectionIDLength:    13,
 					StatelessResetKey:     []byte("foobar"),
 					TokenStore:            tokenStore,
+					EnableDatagrams:       true,
 				}
 				c := populateClientConfig(config, false)
 				Expect(c.HandshakeTimeout).To(Equal(1337 * time.Minute))
@@ -474,6 +475,7 @@ var _ = Describe("Client", func() {
 				Expect(c.ConnectionIDLength).To(Equal(13))
 				Expect(c.StatelessResetKey).To(Equal([]byte("foobar")))
 				Expect(c.TokenStore).To(Equal(tokenStore))
+				Expect(c.EnableDatagrams).To(BeTrue())
 			})
 
 			It("errors when the Config contains an invalid version", func() {
diff --git a/config.go b/config.go
index 7e211e7b..833051f0 100644
--- a/config.go
+++ b/config.go
@@ -98,6 +98,7 @@ func populateConfig(config *Config) *Config {
 		ConnectionIDLength:                    config.ConnectionIDLength,
 		StatelessResetKey:                     config.StatelessResetKey,
 		TokenStore:                            config.TokenStore,
+		EnableDatagrams:                       config.EnableDatagrams,
 		Tracer:                                config.Tracer,
 	}
 }
diff --git a/config_test.go b/config_test.go
index 71aa3e76..f45e8179 100644
--- a/config_test.go
+++ b/config_test.go
@@ -69,6 +69,8 @@ var _ = Describe("Config", func() {
 				f.Set(reflect.ValueOf([]byte{1, 2, 3, 4}))
 			case "KeepAlive":
 				f.Set(reflect.ValueOf(true))
+			case "EnableDatagrams":
+				f.Set(reflect.ValueOf(true))
 			case "Tracer":
 				f.Set(reflect.ValueOf(mocklogging.NewMockTracer(mockCtrl)))
 			default:
diff --git a/interface.go b/interface.go
index e27a81d1..dba6b34c 100644
--- a/interface.go
+++ b/interface.go
@@ -259,7 +259,10 @@ type Config struct {
 	StatelessResetKey []byte
 	// KeepAlive defines whether this peer will periodically send a packet to keep the connection alive.
 	KeepAlive bool
-	Tracer    logging.Tracer
+	// See https://datatracker.ietf.org/doc/draft-ietf-quic-datagram/.
+	// Datagrams will only be available when both peers enable datagram support.
+	EnableDatagrams bool
+	Tracer          logging.Tracer
 }
 
 // ConnectionState records basic details about a QUIC connection