mv internal lib

lib/beacon/multicast.go

@@ -0,0 +1,66 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package beacon
+
+import "net"
+
+type Multicast struct {
+	conn   *net.UDPConn
+	addr   *net.UDPAddr
+	intf   *net.Interface
+	inbox  chan []byte
+	outbox chan recv
+}
+
+func NewMulticast(addr, ifname string) (*Multicast, error) {
+	gaddr, err := net.ResolveUDPAddr("udp6", addr)
+	if err != nil {
+		return nil, err
+	}
+	intf, err := net.InterfaceByName(ifname)
+	if err != nil {
+		return nil, err
+	}
+	conn, err := net.ListenMulticastUDP("udp6", intf, gaddr)
+	if err != nil {
+		return nil, err
+	}
+	b := &Multicast{
+		conn:   conn,
+		addr:   gaddr,
+		intf:   intf,
+		inbox:  make(chan []byte),
+		outbox: make(chan recv, 16),
+	}
+
+	go genericReader(b.conn, b.outbox)
+	go b.writer()
+
+	return b, nil
+}
+
+func (b *Multicast) Send(data []byte) {
+	b.inbox <- data
+}
+
+func (b *Multicast) Recv() ([]byte, net.Addr) {
+	recv := <-b.outbox
+	return recv.data, recv.src
+}
+
+func (b *Multicast) writer() {
+	addr := *b.addr
+	addr.Zone = b.intf.Name
+	for bs := range b.inbox {
+		_, err := b.conn.WriteTo(bs, &addr)
+		if err != nil && debug {
+			l.Debugln(err, "on write to", addr)
+		} else if debug {
+			l.Debugf("sent %d bytes to %s", len(bs), addr.String())
+		}
+	}
+}