lib/connections: Add QUIC protocol support (fixes #5377) (#5737)

lib/config/config.go

@@ -39,6 +39,8 @@ const (
 var (
 	// DefaultTCPPort defines default TCP port used if the URI does not specify one, for example tcp://0.0.0.0
 	DefaultTCPPort = 22000
+	// DefaultQUICPort defines default QUIC port used if the URI does not specify one, for example quic://0.0.0.0
+	DefaultQUICPort = 22000
 	// 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
@@ -46,6 +48,7 @@ var (
 	DefaultListenAddresses = []string{
 		util.Address("tcp", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultTCPPort))),
 		"dynamic+https://relays.syncthing.net/endpoint",
+		util.Address("quic", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultQUICPort))),
 	}
 	DefaultGUIPort = 8384
 	// DefaultDiscoveryServersV4 should be substituted when the configuration
@@ -65,6 +68,30 @@ var (
 	DefaultDiscoveryServers = append(DefaultDiscoveryServersV4, DefaultDiscoveryServersV6...)
 	// DefaultTheme is the default and fallback theme for the web UI.
 	DefaultTheme = "default"
+	// Default stun servers should be substituted when the configuration
+	// contains <stunServer>default</stunServer>.
+
+	// DefaultPrimaryStunServers are servers provided by us (to avoid causing the public servers burden)
+	DefaultPrimaryStunServers = []string{
+		"stun.syncthing.net:3478",
+	}
+	DefaultSecondaryStunServers = []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",
+	}
 )
 
 func New(myID protocol.DeviceID) Configuration {
@@ -258,8 +285,8 @@ func (cfg *Configuration) clean() error {
 		existingFolders[folder.ID] = folder
 	}
 
-	cfg.Options.ListenAddresses = util.UniqueStrings(cfg.Options.ListenAddresses)
-	cfg.Options.GlobalAnnServers = util.UniqueStrings(cfg.Options.GlobalAnnServers)
+	cfg.Options.ListenAddresses = util.UniqueTrimmedStrings(cfg.Options.ListenAddresses)
+	cfg.Options.GlobalAnnServers = util.UniqueTrimmedStrings(cfg.Options.GlobalAnnServers)
 
 	if cfg.Version > 0 && cfg.Version < OldestHandledVersion {
 		l.Warnf("Configuration version %d is deprecated. Attempting best effort conversion, but please verify manually.", cfg.Version)

lib/config/config_test.go

@@ -69,6 +69,9 @@ func TestDefaultValues(t *testing.T) {
 		UnackedNotificationIDs:  []string{},
 		DefaultFolderPath:       "~",
 		SetLowPriority:          true,
+		StunKeepaliveStartS:     180,
+		StunKeepaliveMinS:       20,
+		StunServers:             []string{"default"},
 	}
 
 	cfg := New(device1)
@@ -212,8 +215,11 @@ func TestOverriddenValues(t *testing.T) {
 			"channelNotification",   // added in 17->18 migration
 			"fsWatcherNotification", // added in 27->28 migration
 		},
-		DefaultFolderPath: "/media/syncthing",
-		SetLowPriority:    false,
+		DefaultFolderPath:   "/media/syncthing",
+		SetLowPriority:      false,
+		StunKeepaliveStartS: 9000,
+		StunKeepaliveMinS:   900,
+		StunServers:         []string{"foo"},
 	}
 
 	os.Unsetenv("STNOUPGRADE")

lib/config/optionsconfiguration.go

@@ -52,6 +52,9 @@ type OptionsConfiguration struct {
 	DefaultFolderPath       string   `xml:"defaultFolderPath" json:"defaultFolderPath" default:"~"`
 	SetLowPriority          bool     `xml:"setLowPriority" json:"setLowPriority" default:"true"`
 	MaxConcurrentScans      int      `xml:"maxConcurrentScans" json:"maxConcurrentScans"`
+	StunKeepaliveStartS     int      `xml:"stunKeepaliveStartS" json:"stunKeepaliveStartS" default:"180"` // 0 for off
+	StunKeepaliveMinS       int      `xml:"stunKeepaliveMinS" json:"stunKeepaliveMinS" default:"20"`      // 0 for off
+	StunServers             []string `xml:"stunServer" json:"stunServers" default:"default"`
 
 	DeprecatedUPnPEnabled        bool     `xml:"upnpEnabled,omitempty" json:"-"`
 	DeprecatedUPnPLeaseM         int      `xml:"upnpLeaseMinutes,omitempty" json:"-"`
@@ -61,29 +64,33 @@ type OptionsConfiguration struct {
 	DeprecatedMinHomeDiskFreePct float64  `xml:"minHomeDiskFreePct,omitempty" json:"-"`
 }
 
-func (orig OptionsConfiguration) Copy() OptionsConfiguration {
-	c := orig
-	c.ListenAddresses = make([]string, len(orig.ListenAddresses))
-	copy(c.ListenAddresses, orig.ListenAddresses)
-	c.GlobalAnnServers = make([]string, len(orig.GlobalAnnServers))
-	copy(c.GlobalAnnServers, orig.GlobalAnnServers)
-	c.AlwaysLocalNets = make([]string, len(orig.AlwaysLocalNets))
-	copy(c.AlwaysLocalNets, orig.AlwaysLocalNets)
-	c.UnackedNotificationIDs = make([]string, len(orig.UnackedNotificationIDs))
-	copy(c.UnackedNotificationIDs, orig.UnackedNotificationIDs)
-	return c
+func (opts OptionsConfiguration) Copy() OptionsConfiguration {
+	optsCopy := opts
+	optsCopy.ListenAddresses = make([]string, len(opts.ListenAddresses))
+	copy(optsCopy.ListenAddresses, opts.ListenAddresses)
+	optsCopy.GlobalAnnServers = make([]string, len(opts.GlobalAnnServers))
+	copy(optsCopy.GlobalAnnServers, opts.GlobalAnnServers)
+	optsCopy.AlwaysLocalNets = make([]string, len(opts.AlwaysLocalNets))
+	copy(optsCopy.AlwaysLocalNets, opts.AlwaysLocalNets)
+	optsCopy.UnackedNotificationIDs = make([]string, len(opts.UnackedNotificationIDs))
+	copy(optsCopy.UnackedNotificationIDs, opts.UnackedNotificationIDs)
+	return optsCopy
 }
 
 // RequiresRestartOnly returns a copy with only the attributes that require
 // restart on change.
-func (orig OptionsConfiguration) RequiresRestartOnly() OptionsConfiguration {
-	copy := orig
+func (opts OptionsConfiguration) RequiresRestartOnly() OptionsConfiguration {
+	optsCopy := opts
 	blank := OptionsConfiguration{}
-	util.CopyMatchingTag(&blank, &copy, "restart", func(v string) bool {
+	util.CopyMatchingTag(&blank, &optsCopy, "restart", func(v string) bool {
 		if len(v) > 0 && v != "true" {
-			panic(fmt.Sprintf(`unexpected tag value: %s. expected untagged or "true"`, v))
+			panic(fmt.Sprintf(`unexpected tag value: %s. Expected untagged or "true"`, v))
 		}
 		return v != "true"
 	})
-	return copy
+	return optsCopy
+}
+
+func (opts OptionsConfiguration) IsStunDisabled() bool {
+	return opts.StunKeepaliveMinS < 1 || opts.StunKeepaliveStartS < 1 || !opts.NATEnabled
 }

lib/config/testdata/overridenvalues.xml

@@ -36,5 +36,8 @@
         <tempIndexMinBlocks>100</tempIndexMinBlocks>
         <defaultFolderPath>/media/syncthing</defaultFolderPath>
         <setLowPriority>false</setLowPriority>
+        <stunKeepaliveStartS>9000</stunKeepaliveStartS>
+        <stunKeepaliveMinS>900</stunKeepaliveMinS>
+        <stunServer>foo</stunServer>
     </options>
 </configuration>

lib/config/wrapper.go

@@ -14,6 +14,7 @@ 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"
 )
@@ -88,6 +89,7 @@ type Wrapper interface {
 
 	ListenAddresses() []string
 	GlobalDiscoveryServers() []string
+	StunServers() []string
 
 	Subscribe(c Committer)
 	Unsubscribe(c Committer)
@@ -105,6 +107,30 @@ type wrapper struct {
 	requiresRestart uint32 // an atomic bool
 }
 
+func (w *wrapper) StunServers() []string {
+	var addresses []string
+	for _, addr := range w.cfg.Options.StunServers {
+		switch addr {
+		case "default":
+			defaultPrimaryAddresses := make([]string, len(DefaultPrimaryStunServers))
+			copy(defaultPrimaryAddresses, DefaultPrimaryStunServers)
+			rand.Shuffle(defaultPrimaryAddresses)
+			addresses = append(addresses, defaultPrimaryAddresses...)
+
+			defaultSecondaryAddresses := make([]string, len(DefaultSecondaryStunServers))
+			copy(defaultSecondaryAddresses, DefaultSecondaryStunServers)
+			rand.Shuffle(defaultSecondaryAddresses)
+			addresses = append(addresses, defaultSecondaryAddresses...)
+		default:
+			addresses = append(addresses, addr)
+		}
+	}
+
+	addresses = util.UniqueTrimmedStrings(addresses)
+
+	return addresses
+}
+
 // Wrap wraps an existing Configuration structure and ties it to a file on
 // disk.
 func Wrap(path string, cfg Configuration) Wrapper {
@@ -442,7 +468,7 @@ func (w *wrapper) GlobalDiscoveryServers() []string {
 			servers = append(servers, srv)
 		}
 	}
-	return util.UniqueStrings(servers)
+	return util.UniqueTrimmedStrings(servers)
 }
 
 func (w *wrapper) ListenAddresses() []string {
@@ -455,7 +481,7 @@ func (w *wrapper) ListenAddresses() []string {
 			addresses = append(addresses, addr)
 		}
 	}
-	return util.UniqueStrings(addresses)
+	return util.UniqueTrimmedStrings(addresses)
 }
 
 func (w *wrapper) RequiresRestart() bool {