change multicast config format

src/config/config.go

@@ -27,19 +27,25 @@ import (
 // supply one of these structs to the Yggdrasil core when starting a node.
 type NodeConfig struct {
 	sync.RWMutex        `json:"-"`
-	Peers               []string               `comment:"List of connection strings for outbound peer connections in URI format,\ne.g. tls://a.b.c.d:e or socks://a.b.c.d:e/f.g.h.i:j. These connections\nwill obey the operating system routing table, therefore you should\nuse this section when you may connect via different interfaces."`
+	Peers               []string                   `comment:"List of connection strings for outbound peer connections in URI format,\ne.g. tls://a.b.c.d:e or socks://a.b.c.d:e/f.g.h.i:j. These connections\nwill obey the operating system routing table, therefore you should\nuse this section when you may connect via different interfaces."`
-	InterfacePeers      map[string][]string    `comment:"List of connection strings for outbound peer connections in URI format,\narranged by source interface, e.g. { \"eth0\": [ tls://a.b.c.d:e ] }.\nNote that SOCKS peerings will NOT be affected by this option and should\ngo in the \"Peers\" section instead."`
+	InterfacePeers      map[string][]string        `comment:"List of connection strings for outbound peer connections in URI format,\narranged by source interface, e.g. { \"eth0\": [ tls://a.b.c.d:e ] }.\nNote that SOCKS peerings will NOT be affected by this option and should\ngo in the \"Peers\" section instead."`
-	Listen              []string               `comment:"Listen addresses for incoming connections. You will need to add\nlisteners in order to accept incoming peerings from non-local nodes.\nMulticast peer discovery will work regardless of any listeners set\nhere. Each listener should be specified in URI format as above, e.g.\ntls://0.0.0.0:0 or tls://[::]:0 to listen on all interfaces."`
+	Listen              []string                   `comment:"Listen addresses for incoming connections. You will need to add\nlisteners in order to accept incoming peerings from non-local nodes.\nMulticast peer discovery will work regardless of any listeners set\nhere. Each listener should be specified in URI format as above, e.g.\ntls://0.0.0.0:0 or tls://[::]:0 to listen on all interfaces."`
-	AdminListen         string                 `comment:"Listen address for admin connections. Default is to listen for local\nconnections either on TCP/9001 or a UNIX socket depending on your\nplatform. Use this value for yggdrasilctl -endpoint=X. To disable\nthe admin socket, use the value \"none\" instead."`
+	AdminListen         string                     `comment:"Listen address for admin connections. Default is to listen for local\nconnections either on TCP/9001 or a UNIX socket depending on your\nplatform. Use this value for yggdrasilctl -endpoint=X. To disable\nthe admin socket, use the value \"none\" instead."`
-	MulticastInterfaces []string               `comment:"Regular expressions for which interfaces multicast peer discovery\nshould be enabled on. If none specified, multicast peer discovery is\ndisabled. The default value is .* which uses all interfaces."`
+	MulticastInterfaces []MulticastInterfaceConfig `comment:"Regular expressions for which interfaces multicast peer discovery\nshould be enabled on. If none specified, multicast peer discovery is\ndisabled. The default value is .* which uses all interfaces."`
-	AllowedPublicKeys   []string               `comment:"List of peer public keys to allow incoming peering connections\nfrom. If left empty/undefined then all connections will be allowed\nby default. This does not affect outgoing peerings, nor does it\naffect link-local peers discovered via multicast."`
+	AllowedPublicKeys   []string                   `comment:"List of peer public keys to allow incoming peering connections\nfrom. If left empty/undefined then all connections will be allowed\nby default. This does not affect outgoing peerings, nor does it\naffect link-local peers discovered via multicast."`
-	PublicKey           string                 `comment:"Your public key. Your peers may ask you for this to put\ninto their AllowedPublicKeys configuration."`
+	PublicKey           string                     `comment:"Your public key. Your peers may ask you for this to put\ninto their AllowedPublicKeys configuration."`
-	PrivateKey          string                 `comment:"Your private key. DO NOT share this with anyone!"`
+	PrivateKey          string                     `comment:"Your private key. DO NOT share this with anyone!"`
-	LinkLocalTCPPort    uint16                 `comment:"The port number to be used for the link-local TCP listeners for the\nconfigured MulticastInterfaces. This option does not affect listeners\nspecified in the Listen option. Unless you plan to firewall link-local\ntraffic, it is best to leave this as the default value of 0. This\noption cannot currently be changed by reloading config during runtime."`
+	LinkLocalTCPPort    uint16                     `comment:"The port number to be used for the link-local TCP listeners for the\nconfigured MulticastInterfaces. This option does not affect listeners\nspecified in the Listen option. Unless you plan to firewall link-local\ntraffic, it is best to leave this as the default value of 0. This\noption cannot currently be changed by reloading config during runtime."`
-	IfName              string                 `comment:"Local network interface name for TUN adapter, or \"auto\" to select\nan interface automatically, or \"none\" to run without TUN."`
+	IfName              string                     `comment:"Local network interface name for TUN adapter, or \"auto\" to select\nan interface automatically, or \"none\" to run without TUN."`
-	IfMTU               uint64                 `comment:"Maximum Transmission Unit (MTU) size for your local TUN interface.\nDefault is the largest supported size for your platform. The lowest\npossible value is 1280."`
+	IfMTU               uint64                     `comment:"Maximum Transmission Unit (MTU) size for your local TUN interface.\nDefault is the largest supported size for your platform. The lowest\npossible value is 1280."`
-	NodeInfoPrivacy     bool                   `comment:"By default, nodeinfo contains some defaults including the platform,\narchitecture and Yggdrasil version. These can help when surveying\nthe network and diagnosing network routing problems. Enabling\nnodeinfo privacy prevents this, so that only items specified in\n\"NodeInfo\" are sent back if specified."`
+	NodeInfoPrivacy     bool                       `comment:"By default, nodeinfo contains some defaults including the platform,\narchitecture and Yggdrasil version. These can help when surveying\nthe network and diagnosing network routing problems. Enabling\nnodeinfo privacy prevents this, so that only items specified in\n\"NodeInfo\" are sent back if specified."`
-	NodeInfo            map[string]interface{} `comment:"Optional node info. This must be a { \"key\": \"value\", ... } map\nor set as null. This is entirely optional but, if set, is visible\nto the whole network on request."`
+	NodeInfo            map[string]interface{}     `comment:"Optional node info. This must be a { \"key\": \"value\", ... } map\nor set as null. This is entirely optional but, if set, is visible\nto the whole network on request."`
+}
+
+type MulticastInterfaceConfig struct {
+	Regex    string
+	Incoming bool
+	Outgoing bool
 }
 
 // NewSigningKeys replaces the signing keypair in the NodeConfig with a new

src/defaults/defaults.go

@@ -2,6 +2,8 @@ package defaults
 
 import "github.com/yggdrasil-network/yggdrasil-go/src/config"
 
+type MulticastInterfaceConfig = config.MulticastInterfaceConfig
+
 // Defines which parameters are expected by default for configuration on a
 // specific platform. These values are populated in the relevant defaults_*.go
 // for the platform being targeted. They must be set.
@@ -13,7 +15,7 @@ type platformDefaultParameters struct {
 	DefaultConfigFile string
 
 	// Multicast interfaces
-	DefaultMulticastInterfaces []string
+	DefaultMulticastInterfaces []MulticastInterfaceConfig
 
 	// TUN/TAP
 	MaximumIfMTU  uint64

src/defaults/defaults_darwin.go

@@ -13,9 +13,9 @@ func GetDefaults() platformDefaultParameters {
 		DefaultConfigFile: "/etc/yggdrasil.conf",
 
 		// Multicast interfaces
-		DefaultMulticastInterfaces: []string{
+		DefaultMulticastInterfaces: []MulticastInterfaceConfig{
-			"en.*",
+			{Regex: "en.*", Incoming: true, Outgoing: true},
-			"bridge.*",
+			{Regex: "bridge.*", Incoming: true, Outgoing: true},
 		},
 
 		// TUN/TAP

src/defaults/defaults_freebsd.go

@@ -13,8 +13,8 @@ func GetDefaults() platformDefaultParameters {
 		DefaultConfigFile: "/usr/local/etc/yggdrasil.conf",
 
 		// Multicast interfaces
-		DefaultMulticastInterfaces: []string{
+		DefaultMulticastInterfaces: []MulticastInterfaceConfig{
-			".*",
+			{Regex: ".*", Incoming: true, Outgoing: true},
 		},
 
 		// TUN/TAP

src/defaults/defaults_linux.go

@@ -13,8 +13,8 @@ func GetDefaults() platformDefaultParameters {
 		DefaultConfigFile: "/etc/yggdrasil.conf",
 
 		// Multicast interfaces
-		DefaultMulticastInterfaces: []string{
+		DefaultMulticastInterfaces: []MulticastInterfaceConfig{
-			".*",
+			{Regex: ".*", Incoming: true, Outgoing: true},
 		},
 
 		// TUN/TAP

src/defaults/defaults_openbsd.go

@@ -13,8 +13,8 @@ func GetDefaults() platformDefaultParameters {
 		DefaultConfigFile: "/etc/yggdrasil.conf",
 
 		// Multicast interfaces
-		DefaultMulticastInterfaces: []string{
+		DefaultMulticastInterfaces: []MulticastInterfaceConfig{
-			".*",
+			{Regex: ".*", Incoming: true, Outgoing: true},
 		},
 
 		// TUN/TAP

src/defaults/defaults_other.go

@@ -13,8 +13,8 @@ func GetDefaults() platformDefaultParameters {
 		DefaultConfigFile: "/etc/yggdrasil.conf",
 
 		// Multicast interfaces
-		DefaultMulticastInterfaces: []string{
+		DefaultMulticastInterfaces: []MulticastInterfaceConfig{
-			".*",
+			{Regex: ".*", Incoming: true, Outgoing: true},
 		},
 
 		// TUN/TAP

src/defaults/defaults_windows.go

@@ -13,8 +13,8 @@ func GetDefaults() platformDefaultParameters {
 		DefaultConfigFile: "C:\\Program Files\\Yggdrasil\\yggdrasil.conf",
 
 		// Multicast interfaces
-		DefaultMulticastInterfaces: []string{
+		DefaultMulticastInterfaces: []MulticastInterfaceConfig{
-			".*",
+			{Regex: ".*", Incoming: true, Outgoing: true},
 		},
 
 		// TUN/TAP

src/multicast/multicast.go

@@ -38,8 +38,10 @@ type Multicast struct {
 }
 
 type interfaceInfo struct {
-	iface net.Interface
+	iface    net.Interface
-	addrs []net.Addr
+	addrs    []net.Addr
+	incoming bool
+	outgoing bool
 }
 
 type listenerInfo struct {
@@ -136,18 +138,16 @@ func (m *Multicast) _stop() error {
 }
 
 func (m *Multicast) _updateInterfaces() {
-	interfaces := make(map[string]interfaceInfo)
+	interfaces := m.getAllowedInterfaces()
-	intfs := m.getAllowedInterfaces()
+	for name, info := range interfaces {
-	for _, intf := range intfs {
+		addrs, err := info.iface.Addrs()
-		addrs, err := intf.Addrs()
 		if err != nil {
-			m.log.Warnf("Failed up get addresses for interface %s: %s", intf.Name, err)
+			m.log.Warnf("Failed up get addresses for interface %s: %s", name, err)
+			delete(interfaces, name)
 			continue
 		}
-		interfaces[intf.Name] = interfaceInfo{
+		info.addrs = addrs
-			iface: intf,
+		interfaces[name] = info
-			addrs: addrs,
-		}
 	}
 	m._interfaces = interfaces
 }
@@ -163,10 +163,10 @@ func (m *Multicast) Interfaces() map[string]net.Interface {
 }
 
 // getAllowedInterfaces returns the currently known/enabled multicast interfaces.
-func (m *Multicast) getAllowedInterfaces() map[string]net.Interface {
+func (m *Multicast) getAllowedInterfaces() map[string]interfaceInfo {
-	interfaces := make(map[string]net.Interface)
+	interfaces := make(map[string]interfaceInfo)
 	// Get interface expressions from config
-	exprs := m.config.MulticastInterfaces
+	ifcfgs := m.config.MulticastInterfaces
 	// Ask the system for network interfaces
 	allifaces, err := net.Interfaces()
 	if err != nil {
@@ -188,15 +188,23 @@ func (m *Multicast) getAllowedInterfaces() map[string]net.Interface {
 			// Ignore point-to-point interfaces
 			continue
 		}
-		for _, expr := range exprs {
+		for _, ifcfg := range ifcfgs {
 			// Compile each regular expression
-			e, err := regexp.Compile(expr)
+			e, err := regexp.Compile(ifcfg.Regex)
 			if err != nil {
 				panic(err)
 			}
 			// Does the interface match the regular expression? Store it if so
 			if e.MatchString(iface.Name) {
-				interfaces[iface.Name] = iface
+				if ifcfg.Incoming || ifcfg.Outgoing {
+					info := interfaceInfo{
+						iface:    iface,
+						incoming: ifcfg.Incoming,
+						outgoing: ifcfg.Outgoing,
+					}
+					interfaces[iface.Name] = info
+				}
+				break
 			}
 		}
 	}
@@ -272,8 +280,13 @@ func (m *Multicast) _announce() {
 			if !addrIP.IsLinkLocalUnicast() {
 				continue
 			}
-			// Join the multicast group
+			if info.outgoing {
-			_ = m.sock.JoinGroup(&iface, groupAddr)
+				// Join the multicast group, so we can listen for advertisements to open outgoing connections
+				_ = m.sock.JoinGroup(&iface, groupAddr)
+			}
+			if !info.incoming {
+				break // Don't send multicast advertisements if we don't accept incoming connections
+			}
 			// Try and see if we already have a TCP listener for this interface
 			var info *listenerInfo
 			if nfo, ok := m.listeners[iface.Name]; !ok || nfo.listener.Listener == nil {
@@ -378,7 +391,7 @@ func (m *Multicast) listen() {
 		phony.Block(m, func() {
 			interfaces = m._interfaces
 		})
-		if _, ok := interfaces[from.Zone]; ok {
+		if info, ok := interfaces[from.Zone]; ok && info.outgoing {
 			addr.Zone = ""
 			pin := fmt.Sprintf("/?key=%s", hex.EncodeToString(key))
 			u, err := url.Parse("tls://" + addr.String() + pin)