Remove KCP (fixes #4737) (#4741)

lib/config/config.go

@@ -39,8 +39,6 @@ const (
 var (
 	// DefaultTCPPort defines default TCP port used if the URI does not specify one, for example tcp://0.0.0.0
 	DefaultTCPPort = 22000
-	// DefaultKCPPort defines default KCP (UDP) port used if the URI does not specify one, for example kcp://0.0.0.0
-	DefaultKCPPort = 22020
 	// DefaultListenAddresses should be substituted when the configuration
 	// contains <listenAddress>default</listenAddress>. This is done by the
 	// "consumer" of the configuration as we don't want these saved to the
@@ -48,7 +46,6 @@ var (
 	DefaultListenAddresses = []string{
 		util.Address("tcp", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultTCPPort))),
 		"dynamic+https://relays.syncthing.net/endpoint",
-		util.Address("kcp", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultKCPPort))),
 	}
 	// DefaultDiscoveryServersV4 should be substituted when the configuration
 	// contains <globalAnnounceServer>default-v4</globalAnnounceServer>.
@@ -65,25 +62,6 @@ var (
 	// DefaultDiscoveryServers should be substituted when the configuration
 	// contains <globalAnnounceServer>default</globalAnnounceServer>.
 	DefaultDiscoveryServers = append(DefaultDiscoveryServersV4, DefaultDiscoveryServersV6...)
-	// DefaultStunServers should be substituted when the configuration
-	// contains <stunServer>default</stunServer>.
-	DefaultStunServers = []string{
-		"stun.callwithus.com:3478",
-		"stun.counterpath.com:3478",
-		"stun.counterpath.net:3478",
-		"stun.ekiga.net:3478",
-		"stun.ideasip.com:3478",
-		"stun.internetcalls.com:3478",
-		"stun.schlund.de:3478",
-		"stun.sipgate.net:10000",
-		"stun.sipgate.net:3478",
-		"stun.voip.aebc.com:3478",
-		"stun.voiparound.com:3478",
-		"stun.voipbuster.com:3478",
-		"stun.voipstunt.com:3478",
-		"stun.voxgratia.org:3478",
-		"stun.xten.com:3478",
-	}
 	// DefaultTheme is the default and fallback theme for the web UI.
 	DefaultTheme = "default"
 )
@@ -380,6 +358,16 @@ func (cfg *Configuration) clean() error {
 	}
 	cfg.IgnoredDevices = newIgnoredDevices
 
+	// Deprecated protocols are removed from the list of listeners and
+	// device addresses. So far just kcp*.
+	for _, prefix := range []string{"kcp"} {
+		cfg.Options.ListenAddresses = filterURLSchemePrefix(cfg.Options.ListenAddresses, prefix)
+		for i := range cfg.Devices {
+			dev := &cfg.Devices[i]
+			dev.Addresses = filterURLSchemePrefix(dev.Addresses, prefix)
+		}
+	}
+
 	return nil
 }
 
@@ -768,3 +756,21 @@ func cleanSymlinks(filesystem fs.Filesystem, dir string) {
 		return nil
 	})
 }
+
+// filterURLSchemePrefix returns the list of addresses after removing all
+// entries whose URL scheme matches the given prefix.
+func filterURLSchemePrefix(addrs []string, prefix string) []string {
+	for i := 0; i < len(addrs); i++ {
+		uri, err := url.Parse(addrs[i])
+		if err != nil {
+			continue
+		}
+		if strings.HasPrefix(uri.Scheme, prefix) {
+			// Remove this entry
+			copy(addrs[i:], addrs[i+1:])
+			addrs = addrs[:len(addrs)-1]
+			i--
+		}
+	}
+	return addrs
+}

lib/config/config_test.go

@@ -68,13 +68,6 @@ func TestDefaultValues(t *testing.T) {
 		TempIndexMinBlocks:      10,
 		UnackedNotificationIDs:  []string{},
 		WeakHashSelectionMethod: WeakHashAuto,
-		StunKeepaliveS:          24,
-		StunServers:             []string{"default"},
-		KCPCongestionControl:    true,
-		KCPReceiveWindowSize:    128,
-		KCPSendWindowSize:       128,
-		KCPUpdateIntervalMs:     25,
-		KCPFastResend:           false,
 		DefaultFolderPath:       "~",
 		SetLowPriority:          true,
 	}
@@ -217,13 +210,6 @@ func TestOverriddenValues(t *testing.T) {
 			"channelNotification", // added in 17->18 migration
 		},
 		WeakHashSelectionMethod: WeakHashNever,
-		StunKeepaliveS:          10,
-		StunServers:             []string{"a.stun.com", "b.stun.com"},
-		KCPCongestionControl:    false,
-		KCPReceiveWindowSize:    1280,
-		KCPSendWindowSize:       1280,
-		KCPUpdateIntervalMs:     1000,
-		KCPFastResend:           true,
 		DefaultFolderPath:       "/media/syncthing",
 		SetLowPriority:          false,
 	}
@@ -953,6 +939,32 @@ func TestInvalidFolderIDRejected(t *testing.T) {
 	}
 }
 
+func TestFilterURLSchemePrefix(t *testing.T) {
+	cases := []struct {
+		before []string
+		prefix string
+		after  []string
+	}{
+		{[]string{}, "kcp", []string{}},
+		{[]string{"tcp://foo"}, "kcp", []string{"tcp://foo"}},
+		{[]string{"kcp://foo"}, "kcp", []string{}},
+		{[]string{"tcp6://foo", "kcp6://foo"}, "kcp", []string{"tcp6://foo"}},
+		{[]string{"kcp6://foo", "tcp6://foo"}, "kcp", []string{"tcp6://foo"}},
+		{
+			[]string{"tcp://foo", "tcp4://foo", "kcp://foo", "kcp4://foo", "banana://foo", "banana4://foo", "banananas!"},
+			"kcp",
+			[]string{"tcp://foo", "tcp4://foo", "banana://foo", "banana4://foo", "banananas!"},
+		},
+	}
+
+	for _, tc := range cases {
+		res := filterURLSchemePrefix(tc.before, tc.prefix)
+		if !reflect.DeepEqual(res, tc.after) {
+			t.Errorf("filterURLSchemePrefix => %q, expected %q", res, tc.after)
+		}
+	}
+}
+
 // defaultConfigAsMap returns a valid default config as a JSON-decoded
 // map[string]interface{}. This is useful to override random elements and
 // re-encode into JSON.

lib/config/optionsconfiguration.go

@@ -134,14 +134,6 @@ type OptionsConfiguration struct {
 	UnackedNotificationIDs  []string                `xml:"unackedNotificationID" json:"unackedNotificationIDs"`
 	TrafficClass            int                     `xml:"trafficClass" json:"trafficClass"`
 	WeakHashSelectionMethod WeakHashSelectionMethod `xml:"weakHashSelectionMethod" json:"weakHashSelectionMethod" restart:"true"`
-	StunServers             []string                `xml:"stunServer" json:"stunServers" default:"default"`
-	StunKeepaliveS          int                     `xml:"stunKeepaliveSeconds" json:"stunKeepaliveSeconds" default:"24"`
-	KCPNoDelay              bool                    `xml:"kcpNoDelay" json:"kcpNoDelay" default:"false"`
-	KCPUpdateIntervalMs     int                     `xml:"kcpUpdateIntervalMs" json:"kcpUpdateIntervalMs" default:"25"`
-	KCPFastResend           bool                    `xml:"kcpFastResend" json:"kcpFastResend" default:"false"`
-	KCPCongestionControl    bool                    `xml:"kcpCongestionControl" json:"kcpCongestionControl" default:"true"`
-	KCPSendWindowSize       int                     `xml:"kcpSendWindowSize" json:"kcpSendWindowSize" default:"128"`
-	KCPReceiveWindowSize    int                     `xml:"kcpReceiveWindowSize" json:"kcpReceiveWindowSize" default:"128"`
 	DefaultFolderPath       string                  `xml:"defaultFolderPath" json:"defaultFolderPath" default:"~"`
 	SetLowPriority          bool                    `xml:"setLowPriority" json:"setLowPriority" default:"true"`
 

lib/config/testdata/overridenvalues.xml

@@ -35,14 +35,6 @@
         <overwriteRemoteDeviceNamesOnConnect>true</overwriteRemoteDeviceNamesOnConnect>
         <tempIndexMinBlocks>100</tempIndexMinBlocks>
         <weakHashSelectionMethod>never</weakHashSelectionMethod>
-        <stunKeepaliveSeconds>10</stunKeepaliveSeconds>
-        <stunServer>a.stun.com</stunServer>
-        <stunServer>b.stun.com</stunServer>
-        <kcpCongestionControl>false</kcpCongestionControl>
-        <kcpReceiveWindowSize>1280</kcpReceiveWindowSize>
-        <kcpSendWindowSize>1280</kcpSendWindowSize>
-        <kcpUpdateIntervalMs>1000</kcpUpdateIntervalMs>
-        <kcpFastResend>true</kcpFastResend>
         <defaultFolderPath>/media/syncthing</defaultFolderPath>
         <setLowPriority>false</setLowPriority>
     </options>

lib/config/wrapper.go

@@ -15,7 +15,6 @@ import (
 	"github.com/syncthing/syncthing/lib/fs"
 	"github.com/syncthing/syncthing/lib/osutil"
 	"github.com/syncthing/syncthing/lib/protocol"
-	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/util"
 )
@@ -433,29 +432,6 @@ func (w *Wrapper) setRequiresRestart() {
 	atomic.StoreUint32(&w.requiresRestart, 1)
 }
 
-func (w *Wrapper) StunServers() []string {
-	var addresses []string
-	for _, addr := range w.cfg.Options.StunServers {
-		switch addr {
-		case "default":
-			addresses = append(addresses, DefaultStunServers...)
-		default:
-			addresses = append(addresses, addr)
-		}
-	}
-
-	addresses = util.UniqueStrings(addresses)
-
-	// Shuffle
-	l := len(addresses)
-	for i := range addresses {
-		r := rand.Intn(l)
-		addresses[i], addresses[r] = addresses[r], addresses[i]
-	}
-
-	return addresses
-}
-
 func (w *Wrapper) MyName() string {
 	w.mut.Lock()
 	myID := w.cfg.MyID