package tunnel import ( "fmt" "github.com/cloudflare/cloudflared/tunneldns" "github.com/pkg/errors" "github.com/rs/zerolog" "github.com/urfave/cli/v2" ) func runDNSProxyServer(c *cli.Context, dnsReadySignal chan struct{}, shutdownC <-chan struct{}, log *zerolog.Logger) error { port := c.Int("proxy-dns-port") if port <= 0 || port > 65535 { return errors.New("The 'proxy-dns-port' must be a valid port number in <1, 65535> range.") } maxUpstreamConnections := c.Int("proxy-dns-max-upstream-conns") if maxUpstreamConnections < 0 { return fmt.Errorf("'%s' must be 0 or higher", "proxy-dns-max-upstream-conns") } listener, err := tunneldns.CreateListener(c.String("proxy-dns-address"), uint16(port), c.StringSlice("proxy-dns-upstream"), c.StringSlice("proxy-dns-bootstrap"), maxUpstreamConnections, log) if err != nil { close(dnsReadySignal) listener.Stop() return errors.Wrap(err, "Cannot create the DNS over HTTPS proxy server") } err = listener.Start(dnsReadySignal) if err != nil { return errors.Wrap(err, "Cannot start the DNS over HTTPS proxy server") } <-shutdownC _ = listener.Stop() log.Info().Msg("DNS server stopped") return nil }