Add SetDTLSConnectContextMaker to SettingEngine

Allows a user to set the context used during the DTLS Handshake. This
can be used to extend or reduce the timeout on the DTLS Handshake.

Resolves pion#2477

Author: lisay-yan

dtlstransport.go

@@ -334,6 +334,7 @@ func (t *DTLSTransport) Start(remoteParameters DTLSParameters) error {
 	dtlsConfig.FlightInterval = t.api.settingEngine.dtls.retransmissionInterval
 	dtlsConfig.InsecureSkipVerifyHello = t.api.settingEngine.dtls.insecureSkipHelloVerify
 	dtlsConfig.EllipticCurves = t.api.settingEngine.dtls.ellipticCurves
+	dtlsConfig.ConnectContextMaker = t.api.settingEngine.dtls.connectContextMaker
 
 	// Connect as DTLS Client/Server, function is blocking and we
 	// must not hold the DTLSTransport lock

settingengine.go

@@ -7,6 +7,7 @@
 package webrtc
 
 import (
+	"context"
 	"io"
 	"net"
 	"time"
@@ -63,6 +64,7 @@ type SettingEngine struct {
 		insecureSkipHelloVerify bool
 		retransmissionInterval  time.Duration
 		ellipticCurves          []dtlsElliptic.Curve
+		connectContextMaker     func() (context.Context, func())
 	}
 	sctp struct {
 		maxReceiveBufferSize uint32
@@ -368,6 +370,17 @@ func (e *SettingEngine) SetDTLSEllipticCurves(ellipticCurves ...dtlsElliptic.Cur
 	e.dtls.ellipticCurves = ellipticCurves
 }
 
+// SetDTLSConnectContextMaker sets the context used during the DTLS Handshake.
+// It can be used to extend or reduce the timeout on the DTLS Handshake.
+// If nil, the default dtls.ConnectContextMaker is used. It can be implemented as following.
+//
+//	func ConnectContextMaker() (context.Context, func()) {
+//		return context.WithTimeout(context.Background(), 30*time.Second)
+//	}
+func (e *SettingEngine) SetDTLSConnectContextMaker(connectContextMaker func() (context.Context, func())) {
+	e.dtls.connectContextMaker = connectContextMaker
+}
+
 // SetSCTPMaxReceiveBufferSize sets the maximum receive buffer size.
 // Leave this 0 for the default maxReceiveBufferSize.
 func (e *SettingEngine) SetSCTPMaxReceiveBufferSize(maxReceiveBufferSize uint32) {

settingengine_test.go

@@ -7,6 +7,7 @@
 package webrtc
 
 import (
+	"context"
 	"net"
 	"testing"
 	"time"
@@ -252,6 +253,14 @@ func TestSetDTLSEllipticCurves(t *testing.T) {
 	}
 }
 
+func TestSetDTLSHandShakeTimeout(*testing.T) {
+	s := SettingEngine{}
+
+	s.SetDTLSConnectContextMaker(func() (context.Context, func()) {
+		return context.WithTimeout(context.Background(), 60*time.Second)
+	})
+}
+
 func TestSetSCTPMaxReceiverBufferSize(t *testing.T) {
 	s := SettingEngine{}
 	assert.Equal(t, uint32(0), s.sctp.maxReceiveBufferSize)