lib/connections: Add KCP support (fixes #804)

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3489

lib/config/config.go

@@ -13,10 +13,12 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"net"
 	"net/url"
 	"os"
 	"path"
 	"sort"
+	"strconv"
 	"strings"
 
 	"github.com/syncthing/syncthing/lib/protocol"
@@ -32,12 +34,17 @@ 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
 	// config.
 	DefaultListenAddresses = []string{
-		"tcp://0.0.0.0:22000",
+		util.Address("tcp", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultTCPPort))),
+		util.Address("kcp", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultKCPPort))),
 		"dynamic+https://relays.syncthing.net/endpoint",
 	}
 	// DefaultDiscoveryServersV4 should be substituted when the configuration
@@ -57,7 +64,25 @@ 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"
 )

lib/config/config_test.go

@@ -65,6 +65,8 @@ func TestDefaultValues(t *testing.T) {
 		TempIndexMinBlocks:      10,
 		UnackedNotificationIDs:  []string{},
 		WeakHashSelectionMethod: WeakHashAuto,
+		StunKeepaliveS:          24,
+		StunServers:             []string{"default"},
 	}
 
 	cfg := New(device1)
@@ -203,6 +205,8 @@ func TestOverriddenValues(t *testing.T) {
 			"channelNotification", // added in 17->18 migration
 		},
 		WeakHashSelectionMethod: WeakHashNever,
+		StunKeepaliveS:          10,
+		StunServers:             []string{"a.stun.com", "b.stun.com"},
 	}
 
 	os.Unsetenv("STNOUPGRADE")

lib/config/optionsconfiguration.go

@@ -131,6 +131,8 @@ type OptionsConfiguration struct {
 	UnackedNotificationIDs  []string                `xml:"unackedNotificationID" json:"unackedNotificationIDs"`
 	TrafficClass            int                     `xml:"trafficClass" json:"trafficClass"`
 	WeakHashSelectionMethod WeakHashSelectionMethod `xml:"weakHashSelectionMethod" json:"weakHashSelectionMethod"`
+	StunServers             []string                `xml:"stunServer" json:"stunServers" default:"default"`
+	StunKeepaliveS          int                     `xml:"stunKeepaliveSeconds" json:"stunKeepaliveSeconds" default:"24"`
 
 	DeprecatedUPnPEnabled  bool     `xml:"upnpEnabled,omitempty" json:"-"`
 	DeprecatedUPnPLeaseM   int      `xml:"upnpLeaseMinutes,omitempty" json:"-"`

lib/config/testdata/overridenvalues.xml

@@ -35,5 +35,8 @@
         <overwriteRemoteDeviceNamesOnConnect>true</overwriteRemoteDeviceNamesOnConnect>
         <tempIndexMinBlocks>100</tempIndexMinBlocks>
         <weakHashSelectionMethod>never</weakHashSelectionMethod>
+        <stunKeepaliveSeconds>10</stunKeepaliveSeconds>
+        <stunServer>a.stun.com</stunServer>
+        <stunServer>b.stun.com</stunServer>
     </options>
 </configuration>

lib/config/wrapper.go

@@ -13,6 +13,7 @@ import (
 	"github.com/syncthing/syncthing/lib/events"
 	"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"
 )
@@ -404,3 +405,26 @@ func (w *Wrapper) RequiresRestart() bool {
 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
+}