101 lines
1.7 KiB
Go
101 lines
1.7 KiB
Go
package sacn
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import (
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"net"
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"time"
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"golang.org/x/net/ipv4"
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)
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type Receiver struct {
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conn *ipv4.PacketConn
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rawConn net.PacketConn
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handler func(src *net.UDPAddr, pkt interface{})
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done chan struct{}
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}
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func NewReceiver(ifaceName string) (*Receiver, error) {
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c, err := net.ListenPacket("udp4", ":5568")
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if err != nil {
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return nil, err
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}
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p := ipv4.NewPacketConn(c)
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if ifaceName != "" {
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iface, err := net.InterfaceByName(ifaceName)
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if err != nil {
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c.Close()
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return nil, err
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}
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p.SetMulticastInterface(iface)
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}
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return &Receiver{
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conn: p,
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rawConn: c,
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done: make(chan struct{}),
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}, nil
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}
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func (r *Receiver) JoinUniverse(iface *net.Interface, universe uint16) error {
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group := net.IPv4(239, 255, byte(universe>>8), byte(universe&0xff))
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return r.conn.JoinGroup(iface, &net.UDPAddr{IP: group})
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}
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func (r *Receiver) JoinDiscovery(iface *net.Interface) error {
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return r.conn.JoinGroup(iface, DiscoveryAddr)
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}
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func (r *Receiver) SetHandler(fn func(src *net.UDPAddr, pkt interface{})) {
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r.handler = fn
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}
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func (r *Receiver) Start() {
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go r.receiveLoop()
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}
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func (r *Receiver) Stop() {
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select {
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case <-r.done:
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default:
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close(r.done)
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}
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r.rawConn.Close()
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}
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func (r *Receiver) receiveLoop() {
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buf := make([]byte, 638)
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for {
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select {
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case <-r.done:
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return
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default:
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}
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r.rawConn.SetReadDeadline(time.Now().Add(1 * time.Second))
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n, _, src, err := r.conn.ReadFrom(buf)
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if err != nil {
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if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
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continue
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}
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select {
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case <-r.done:
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return
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default:
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continue
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}
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}
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pkt, err := ParsePacket(buf[:n])
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if err != nil {
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continue
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}
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if r.handler != nil {
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r.handler(src.(*net.UDPAddr), pkt)
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}
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}
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}
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