Define module.Module interface, update admin/tuntap/multicast modules to comply with it, fix #581

cmd/yggdrasil/main.go

@@ -23,6 +23,7 @@ import (
 	"github.com/yggdrasil-network/yggdrasil-go/src/admin"
 	"github.com/yggdrasil-network/yggdrasil-go/src/config"
 	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
+	"github.com/yggdrasil-network/yggdrasil-go/src/module"
 	"github.com/yggdrasil-network/yggdrasil-go/src/multicast"
 	"github.com/yggdrasil-network/yggdrasil-go/src/tuntap"
 	"github.com/yggdrasil-network/yggdrasil-go/src/version"
@@ -32,9 +33,9 @@ import (
 type node struct {
 	core      yggdrasil.Core
 	state     *config.NodeState
-	tuntap    tuntap.TunAdapter
-	multicast multicast.Multicast
-	admin     admin.AdminSocket
+	tuntap    module.Module // tuntap.TunAdapter
+	multicast module.Module // multicast.Multicast
+	admin     module.Module // admin.AdminSocket
 }
 
 func readConfig(useconf *bool, useconffile *string, normaliseconf *bool) *config.NodeConfig {
@@ -231,25 +232,30 @@ func main() {
 	}
 	// Register the session firewall gatekeeper function
 	n.core.SetSessionGatekeeper(n.sessionFirewall)
+	// Allocate our modules
+	n.admin = &admin.AdminSocket{}
+	n.multicast = &multicast.Multicast{}
+	n.tuntap = &tuntap.TunAdapter{}
 	// Start the admin socket
 	n.admin.Init(&n.core, n.state, logger, nil)
 	if err := n.admin.Start(); err != nil {
 		logger.Errorln("An error occurred starting admin socket:", err)
 	}
+	n.admin.SetupAdminHandlers(n.admin.(*admin.AdminSocket))
 	// Start the multicast interface
 	n.multicast.Init(&n.core, n.state, logger, nil)
 	if err := n.multicast.Start(); err != nil {
 		logger.Errorln("An error occurred starting multicast:", err)
 	}
-	n.multicast.SetupAdminHandlers(&n.admin)
+	n.multicast.SetupAdminHandlers(n.admin.(*admin.AdminSocket))
 	// Start the TUN/TAP interface
 	if listener, err := n.core.ConnListen(); err == nil {
 		if dialer, err := n.core.ConnDialer(); err == nil {
-			n.tuntap.Init(n.state, logger, listener, dialer)
+			n.tuntap.Init(&n.core, n.state, logger, tuntap.TunOptions{Listener: listener, Dialer: dialer})
 			if err := n.tuntap.Start(); err != nil {
 				logger.Errorln("An error occurred starting TUN/TAP:", err)
 			}
-			n.tuntap.SetupAdminHandlers(&n.admin)
+			n.tuntap.SetupAdminHandlers(n.admin.(*admin.AdminSocket))
 		} else {
 			logger.Errorln("Unable to get Dialer:", err)
 		}

go.mod

@@ -17,3 +17,5 @@ require (
 	golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a
 	golang.org/x/text v0.3.2
 )
+
+go 1.13

src/admin/admin.go

@@ -27,10 +27,10 @@ import (
 type AdminSocket struct {
 	core       *yggdrasil.Core
 	log        *log.Logger
-	reconfigure chan chan error
 	listenaddr string
 	listener   net.Listener
 	handlers   map[string]handler
+	started    bool
 }
 
 // Info refers to information that is returned to the admin socket handler.
@@ -54,25 +54,27 @@ func (a *AdminSocket) AddHandler(name string, args []string, handlerfunc func(In
 }
 
 // init runs the initial admin setup.
-func (a *AdminSocket) Init(c *yggdrasil.Core, state *config.NodeState, log *log.Logger, options interface{}) {
+func (a *AdminSocket) Init(c *yggdrasil.Core, state *config.NodeState, log *log.Logger, options interface{}) error {
 	a.core = c
 	a.log = log
-	a.reconfigure = make(chan chan error, 1)
 	a.handlers = make(map[string]handler)
-	go func() {
-		for {
-			e := <-a.reconfigure
-			current, previous := state.GetCurrent(), state.GetPrevious()
-			if current.AdminListen != previous.AdminListen {
-				a.listenaddr = current.AdminListen
-				a.Stop()
-				a.Start()
-			}
-			e <- nil
-		}
-	}()
 	current := state.GetCurrent()
 	a.listenaddr = current.AdminListen
+	return nil
+}
+
+func (a *AdminSocket) UpdateConfig(config *config.NodeConfig) {
+	a.log.Debugln("Reloading admin configuration...")
+	if a.listenaddr != config.AdminListen {
+		a.listenaddr = config.AdminListen
+		if a.IsStarted() {
+			a.Stop()
+		}
+		a.Start()
+	}
+}
+
+func (a *AdminSocket) SetupAdminHandlers(na *AdminSocket) {
 	a.AddHandler("list", []string{}, func(in Info) (Info, error) {
 		handlers := make(map[string]interface{})
 		for handlername, handler := range a.handlers {
@@ -81,15 +83,15 @@ func (a *AdminSocket) Init(c *yggdrasil.Core, state *config.NodeState, log *log.
 		return Info{"list": handlers}, nil
 	})
 	a.AddHandler("getSelf", []string{}, func(in Info) (Info, error) {
-		ip := c.Address().String()
-		subnet := c.Subnet()
+		ip := a.core.Address().String()
+		subnet := a.core.Subnet()
 		return Info{
 			"self": Info{
 				ip: Info{
-					"box_pub_key":   c.EncryptionPublicKey(),
+					"box_pub_key":   a.core.EncryptionPublicKey(),
 					"build_name":    version.BuildName(),
 					"build_version": version.BuildVersion(),
-					"coords":        fmt.Sprintf("%v", c.Coords()),
+					"coords":        fmt.Sprintf("%v", a.core.Coords()),
 					"subnet":        subnet.String(),
 				},
 			},
@@ -312,17 +314,24 @@ func (a *AdminSocket) Init(c *yggdrasil.Core, state *config.NodeState, log *log.
 	})
 }
 
-// start runs the admin API socket to listen for / respond to admin API calls.
+// Start runs the admin API socket to listen for / respond to admin API calls.
 func (a *AdminSocket) Start() error {
 	if a.listenaddr != "none" && a.listenaddr != "" {
 		go a.listen()
+		a.started = true
 	}
 	return nil
 }
 
-// cleans up when stopping
+// IsStarted returns true if the module has been started.
+func (a *AdminSocket) IsStarted() bool {
+	return a.started
+}
+
+// Stop will stop the admin API and close the socket.
 func (a *AdminSocket) Stop() error {
 	if a.listener != nil {
+		a.started = false
 		return a.listener.Close()
 	} else {
 		return nil

src/module/module.go

@@ -0,0 +1,20 @@
+package module
+
+import (
+	"github.com/gologme/log"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/admin"
+	"github.com/yggdrasil-network/yggdrasil-go/src/config"
+	"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
+)
+
+// Module is an interface that defines which functions must be supported by a
+// given Yggdrasil module.
+type Module interface {
+	Init(core *yggdrasil.Core, state *config.NodeState, log *log.Logger, options interface{}) error
+	Start() error
+	Stop() error
+	UpdateConfig(config *config.NodeConfig)
+	SetupAdminHandlers(a *admin.AdminSocket)
+	IsStarted() bool
+}

src/multicast/multicast.go

@@ -55,6 +55,12 @@ func (m *Multicast) Init(core *yggdrasil.Core, state *config.NodeState, log *log
 // listen for multicast beacons from other hosts and will advertise multicast
 // beacons out to the network.
 func (m *Multicast) Start() error {
+	if len(m.config.GetCurrent().MulticastInterfaces) == 0 {
+		return fmt.Errorf("no MulticastInterfaces configured")
+	}
+
+	m.log.Infoln("Starting multicast module")
+
 	addr, err := net.ResolveUDPAddr("udp", m.groupAddr)
 	if err != nil {
 		return err
@@ -80,8 +86,14 @@ func (m *Multicast) Start() error {
 	return nil
 }
 
+// IsStarted returns true if the module has been started.
+func (m *Multicast) IsStarted() bool {
+	return m.isOpen
+}
+
 // Stop is not implemented for multicast yet.
 func (m *Multicast) Stop() error {
+	m.log.Infoln("Stopping multicast module")
 	m.isOpen = false
 	if m.announcer != nil {
 		m.announcer.Stop()
@@ -98,7 +110,16 @@ func (m *Multicast) Stop() error {
 // needed.
 func (m *Multicast) UpdateConfig(config *config.NodeConfig) {
 	m.log.Debugln("Reloading multicast configuration...")
+	if m.IsStarted() {
+		if len(config.MulticastInterfaces) == 0 || config.LinkLocalTCPPort != m.listenPort {
+			m.Stop()
+		}
+	}
 	m.config.Replace(*config)
+	m.listenPort = config.LinkLocalTCPPort
+	if !m.IsStarted() && len(config.MulticastInterfaces) > 0 {
+		m.Start()
+	}
 }
 
 // GetInterfaces returns the currently known/enabled multicast interfaces. It is

src/tuntap/tun.go

@@ -56,6 +56,11 @@ type TunAdapter struct {
 	isOpen       bool
 }
 
+type TunOptions struct {
+	Listener *yggdrasil.Listener
+	Dialer   *yggdrasil.Dialer
+}
+
 // Gets the maximum supported MTU for the platform based on the defaults in
 // defaults.GetDefaults().
 func getSupportedMTU(mtu int) int {
@@ -110,16 +115,21 @@ func MaximumMTU() int {
 
 // Init initialises the TUN/TAP module. You must have acquired a Listener from
 // the Yggdrasil core before this point and it must not be in use elsewhere.
-func (tun *TunAdapter) Init(config *config.NodeState, log *log.Logger, listener *yggdrasil.Listener, dialer *yggdrasil.Dialer) {
+func (tun *TunAdapter) Init(core *yggdrasil.Core, config *config.NodeState, log *log.Logger, options interface{}) error {
+	tunoptions, ok := options.(TunOptions)
+	if !ok {
+		return fmt.Errorf("invalid options supplied to TunAdapter module")
+	}
 	tun.config = config
 	tun.log = log
-	tun.listener = listener
-	tun.dialer = dialer
+	tun.listener = tunoptions.Listener
+	tun.dialer = tunoptions.Dialer
 	tun.addrToConn = make(map[address.Address]*tunConn)
 	tun.subnetToConn = make(map[address.Subnet]*tunConn)
 	tun.dials = make(map[string][][]byte)
 	tun.writer.tun = tun
 	tun.reader.tun = tun
+	return nil
 }
 
 // Start the setup process for the TUN/TAP adapter. If successful, starts the
@@ -160,13 +170,6 @@ func (tun *TunAdapter) _start() error {
 		return nil
 	}
 	tun.isOpen = true
-	tun.reconfigure = make(chan chan error)
-	go func() {
-		for {
-			e := <-tun.reconfigure
-			e <- nil
-		}
-	}()
 	go tun.handler()
 	tun.reader.Act(nil, tun.reader._read) // Start the reader
 	tun.icmpv6.Init(tun)
@@ -177,6 +180,11 @@ func (tun *TunAdapter) _start() error {
 	return nil
 }
 
+// IsStarted returns true if the module has been started.
+func (tun *TunAdapter) IsStarted() bool {
+	return tun.isOpen
+}
+
 // Start the setup process for the TUN/TAP adapter. If successful, starts the
 // read/write goroutines to handle packets on that interface.
 func (tun *TunAdapter) Stop() error {