Revert active TCP candidate support

This reverts commit 00bbd29
and 1d502ca

agent.go

@@ -9,7 +9,6 @@ import (
 	"context"
 	"fmt"
 	"net"
-	"strconv"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -73,8 +72,6 @@ type Agent struct {
 	prflxAcceptanceMinWait time.Duration
 	relayAcceptanceMinWait time.Duration
 
-	tcpPriorityOffset uint16
-
 	portMin uint16
 	portMax uint16
 
@@ -588,44 +585,6 @@ func (a *Agent) getBestValidCandidatePair() *CandidatePair {
 }
 
 func (a *Agent) addPair(local, remote Candidate) *CandidatePair {
-	if local.TCPType() == TCPTypeActive && remote.TCPType() == TCPTypeActive {
-		return nil
-	}
-
-	if local.TCPType() == TCPTypeActive && remote.TCPType() == TCPTypePassive {
-		addressToConnect := net.JoinHostPort(remote.Address(), strconv.Itoa(remote.Port()))
-
-		conn, err := a.net.Dial("tcp", addressToConnect)
-		if err != nil {
-			a.log.Errorf("Failed to dial TCP address %s: %v", addressToConnect, err)
-			return nil
-		}
-
-		packetConn := newTCPPacketConn(tcpPacketParams{
-			ReadBuffer: tcpReadBufferSize,
-			LocalAddr:  conn.LocalAddr(),
-			Logger:     a.log,
-		})
-
-		if err = packetConn.AddConn(conn, nil); err != nil {
-			a.log.Errorf("Failed to add TCP connection: %v", err)
-			return nil
-		}
-
-		localAddress, ok := conn.LocalAddr().(*net.TCPAddr)
-		if !ok {
-			a.log.Errorf("Failed to cast local address to TCP address")
-			return nil
-		}
-
-		localCandidateHost, ok := local.(*CandidateHost)
-		if !ok {
-			a.log.Errorf("Failed to cast local candidate to CandidateHost")
-			return nil
-		}
-		localCandidateHost.port = localAddress.Port // This causes a data race with candidateBase.Port()
-		local.start(a, packetConn, a.startedCh)
-	}
 	p := newCandidatePair(local, remote, a.isControlling)
 	a.checklist = append(a.checklist, p)
 	return p
@@ -802,9 +761,7 @@ func (a *Agent) addCandidate(ctx context.Context, c Candidate, candidateConn net
 			}
 		}
 
-		if c.TCPType() != TCPTypeActive {
-			c.start(a, candidateConn, a.startedCh)
-		}
+		c.start(a, candidateConn, a.startedCh)
 
 		set = append(set, c)
 		a.localCandidates[c.NetworkType()] = set
@@ -1072,19 +1029,13 @@ func (a *Agent) handleInbound(m *stun.Message, local Candidate, remote net.Addr)
 				return
 			}
 
-			remoteTCPType := TCPTypeUnspecified
-			if local.TCPType() == TCPTypePassive {
-				remoteTCPType = TCPTypeActive
-			}
-
 			prflxCandidateConfig := CandidatePeerReflexiveConfig{
 				Network:   networkType.String(),
 				Address:   ip.String(),
 				Port:      port,
 				Component: local.Component(),
 				RelAddr:   "",
 				RelPort:   0,
-				TCPType:   remoteTCPType,
 			}
 
 			prflxCandidate, err := NewCandidatePeerReflexive(&prflxCandidateConfig)

agent_config.go

@@ -41,18 +41,11 @@ const (
 	// defaultMaxBindingRequests is the maximum number of binding requests before considering a pair failed
 	defaultMaxBindingRequests = 7
 
-	// TCPPriorityOffset is a number which is subtracted from the default (UDP) candidate type preference
-	// for host, srflx and prfx candidate types.
-	defaultTCPPriorityOffset = 27
-
 	// maxBufferSize is the number of bytes that can be buffered before we start to error
 	maxBufferSize = 1000 * 1000 // 1MB
 
 	// maxBindingRequestTimeout is the wait time before binding requests can be deleted
 	maxBindingRequestTimeout = 4000 * time.Millisecond
-
-	// tcpReadBufferSize is the size of the read buffer of tcpPacketConn used by active tcp candidate
-	tcpReadBufferSize = 8
 )
 
 func defaultCandidateTypes() []CandidateType {
@@ -181,12 +174,6 @@ type AgentConfig struct {
 
 	// Include loopback addresses in the candidate list.
 	IncludeLoopback bool
-
-	// TCPPriorityOffset is a number which is subtracted from the default (UDP) candidate type preference
-	// for host, srflx and prfx candidate types. It helps to configure relative preference of UDP candidates
-	// against TCP ones. Relay candidates for TCP and UDP are always 0 and not affected by this setting.
-	// When this is nil, defaultTCPPriorityOffset is used.
-	TCPPriorityOffset *uint16
 }
 
 // initWithDefaults populates an agent and falls back to defaults if fields are unset
@@ -221,12 +208,6 @@ func (config *AgentConfig) initWithDefaults(a *Agent) {
 		a.relayAcceptanceMinWait = *config.RelayAcceptanceMinWait
 	}
 
-	if config.TCPPriorityOffset == nil {
-		a.tcpPriorityOffset = defaultTCPPriorityOffset
-	} else {
-		a.tcpPriorityOffset = *config.TCPPriorityOffset
-	}
-
 	if config.DisconnectedTimeout == nil {
 		a.disconnectedTimeout = defaultDisconnectedTimeout
 	} else {

agent_test.go

@@ -1637,7 +1637,7 @@ func TestAcceptAggressiveNomination(t *testing.T) {
 
 	KeepaliveInterval := time.Hour
 	cfg0 := &AgentConfig{
-		NetworkTypes:     []NetworkType{NetworkTypeUDP4, NetworkTypeUDP6},
+		NetworkTypes:     supportedNetworkTypes(),
 		MulticastDNSMode: MulticastDNSModeDisabled,
 		Net:              net0,
 
@@ -1652,7 +1652,7 @@ func TestAcceptAggressiveNomination(t *testing.T) {
 	require.NoError(t, aAgent.OnConnectionStateChange(aNotifier))
 
 	cfg1 := &AgentConfig{
-		NetworkTypes:      []NetworkType{NetworkTypeUDP4, NetworkTypeUDP6},
+		NetworkTypes:      supportedNetworkTypes(),
 		MulticastDNSMode:  MulticastDNSModeDisabled,
 		Net:               net1,
 		KeepaliveInterval: &KeepaliveInterval,