Method addrDiscoveryLoop

net/udprelay/server.go:458–560

()

}

func (s *Server) addrDiscoveryLoop() {
	defer s.wg.Done()
	timer := time.NewTimer(0) // fire immediately
	defer timer.Stop()

	getAddrPorts := func() ([]netip.AddrPort, error) {
		ctx, cancel := context.WithCancel(context.Background())
		defer cancel()

		var addrPorts set.Set[netip.AddrPort]
		addrPorts.Make()

		// get local addresses
		ips, _, err := netmon.LocalAddresses()
		if err != nil {
			return nil, err
		}
		for _, ip := range ips {
			if ip.IsValid() {
				if ip.Is4() {
					addrPorts.Add(netip.AddrPortFrom(ip, s.uc4Port))
				} else {
					addrPorts.Add(netip.AddrPortFrom(ip, s.uc6Port))
				}
			}
		}

		// Get cloud metadata service addresses.
		// TODO(illotum) Same is done within magicsock, consider caching within cloudInfo
		cloudIPs, err := s.cloudInfo.GetPublicIPs(ctx)
		if err == nil { // Not handling the err, GetPublicIPs already printed to log.
			for _, ip := range cloudIPs {
				if ip.IsValid() {
					if ip.Is4() {
						addrPorts.Add(netip.AddrPortFrom(ip, s.uc4Port))
					} else {
						addrPorts.Add(netip.AddrPortFrom(ip, s.uc6Port))
					}
				}
			}
		}

		dm := s.getDERPMap()
		if dm == nil {
			// We don't have a DERPMap which is required to dynamically
			// discover external addresses, but we can return the endpoints we
			// do have.
			return addrPorts.Slice(), nil
		}

		// get addrPorts as visible from DERP
		rep, err := s.netChecker.GetReport(ctx, dm, &netcheck.GetReportOpts{
			OnlySTUN: true,
		})
		if err != nil {
			return nil, err
		}
		// Add STUN-discovered endpoints with their observed ports.