Allow listen.host to contain names (#825)

examples/config.yml

@@ -107,7 +107,7 @@ lighthouse:
 # Port Nebula will be listening on. The default here is 4242. For a lighthouse node, the port should be defined,
 # however using port 0 will dynamically assign a port and is recommended for roaming nodes.
 listen:
-  # To listen on both any ipv4 and ipv6 use "[::]"
+  # To listen on both any ipv4 and ipv6 use "::"
   host: 0.0.0.0
   port: 4242
   # Sets the max number of packets to pull from the kernel for each syscall (under systems that support recvmmsg)

main.go

@@ -151,8 +151,21 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 	port := c.GetInt("listen.port", 0)
 
 	if !configTest {
+		rawListenHost := c.GetString("listen.host", "0.0.0.0")
+		var listenHost *net.IPAddr
+		if rawListenHost == "[::]" {
+			// Old guidance was to provide the literal `[::]` in `listen.host` but that won't resolve.
+			listenHost = &net.IPAddr{IP: net.IPv6zero}
+
+		} else {
+			listenHost, err = net.ResolveIPAddr("ip", rawListenHost)
+			if err != nil {
+				return nil, util.NewContextualError("Failed to resolve listen.host", nil, err)
+			}
+		}
+
 		for i := 0; i < routines; i++ {
-			udpServer, err := udp.NewListener(l, c.GetString("listen.host", "0.0.0.0"), port, routines > 1, c.GetInt("listen.batch", 64))
+			udpServer, err := udp.NewListener(l, listenHost.IP, port, routines > 1, c.GetInt("listen.batch", 64))
 			if err != nil {
 				return nil, util.NewContextualError("Failed to open udp listener", m{"queue": i}, err)
 			}

udp/udp_generic.go

@@ -23,9 +23,9 @@ type Conn struct {
 	l *logrus.Logger
 }
 
-func NewListener(l *logrus.Logger, ip string, port int, multi bool, batch int) (*Conn, error) {
+func NewListener(l *logrus.Logger, ip net.IP, port int, multi bool, batch int) (*Conn, error) {
 	lc := NewListenConfig(multi)
-	pc, err := lc.ListenPacket(context.TODO(), "udp", fmt.Sprintf("%s:%d", ip, port))
+	pc, err := lc.ListenPacket(context.TODO(), "udp", net.JoinHostPort(ip.String(), fmt.Sprintf("%v", port)))
 	if err != nil {
 		return nil, err
 	}

udp/udp_linux.go

@@ -45,7 +45,7 @@ const (
 
 type _SK_MEMINFO [_SK_MEMINFO_VARS]uint32
 
-func NewListener(l *logrus.Logger, ip string, port int, multi bool, batch int) (*Conn, error) {
+func NewListener(l *logrus.Logger, ip net.IP, port int, multi bool, batch int) (*Conn, error) {
 	syscall.ForkLock.RLock()
 	fd, err := unix.Socket(unix.AF_INET6, unix.SOCK_DGRAM, unix.IPPROTO_UDP)
 	if err == nil {
@@ -59,7 +59,7 @@ func NewListener(l *logrus.Logger, ip string, port int, multi bool, batch int) (
 	}
 
 	var lip [16]byte
-	copy(lip[:], net.ParseIP(ip))
+	copy(lip[:], ip.To16())
 
 	if multi {
 		if err = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil {

udp/udp_tester.go

@@ -45,9 +45,9 @@ type Conn struct {
 	l *logrus.Logger
 }
 
-func NewListener(l *logrus.Logger, ip string, port int, _ bool, _ int) (*Conn, error) {
+func NewListener(l *logrus.Logger, ip net.IP, port int, _ bool, _ int) (*Conn, error) {
 	return &Conn{
-		Addr:      &Addr{net.ParseIP(ip), uint16(port)},
+		Addr:      &Addr{ip, uint16(port)},
 		RxPackets: make(chan *Packet, 10),
 		TxPackets: make(chan *Packet, 10),
 		l:         l,