add network feature for relay

listener/serial/listener.go

@@ -0,0 +1,118 @@
+package serial
+
+import (
+	"context"
+	"net"
+	"time"
+
+	"github.com/go-gost/core/listener"
+	"github.com/go-gost/core/logger"
+	md "github.com/go-gost/core/metadata"
+	serial_util "github.com/go-gost/x/internal/util/serial"
+	limiter "github.com/go-gost/x/limiter/traffic/wrapper"
+	metrics "github.com/go-gost/x/metrics/wrapper"
+	"github.com/go-gost/x/registry"
+	goserial "github.com/tarm/serial"
+)
+
+func init() {
+	registry.ListenerRegistry().Register("serial", NewListener)
+}
+
+type serialListener struct {
+	cqueue  chan net.Conn
+	closed  chan struct{}
+	addr    net.Addr
+	logger  logger.Logger
+	md      metadata
+	options listener.Options
+}
+
+func NewListener(opts ...listener.Option) listener.Listener {
+	options := listener.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	if options.Addr == "" {
+		options.Addr = serial_util.DefaultPort
+	}
+
+	return &serialListener{
+		logger:  options.Logger,
+		options: options,
+	}
+}
+
+func (l *serialListener) Init(md md.Metadata) (err error) {
+	if err = l.parseMetadata(md); err != nil {
+		return
+	}
+
+	l.addr = &serial_util.Addr{Port: l.options.Addr}
+
+	l.cqueue = make(chan net.Conn)
+	l.closed = make(chan struct{})
+
+	go l.listenLoop()
+
+	return
+}
+
+func (l *serialListener) Accept() (conn net.Conn, err error) {
+	select {
+	case conn := <-l.cqueue:
+		return conn, nil
+	case <-l.closed:
+	}
+
+	return nil, listener.ErrClosed
+}
+
+func (l *serialListener) Addr() net.Addr {
+	return l.addr
+}
+
+func (l *serialListener) Close() error {
+	select {
+	case <-l.closed:
+		return net.ErrClosed
+	default:
+		close(l.closed)
+	}
+	return nil
+}
+
+func (l *serialListener) listenLoop() {
+	for {
+		ctx, cancel := context.WithCancel(context.Background())
+		err := func() error {
+			cfg := serial_util.ParseConfigFromAddr(l.options.Addr)
+			cfg.ReadTimeout = l.md.timeout
+			port, err := goserial.OpenPort(cfg)
+			if err != nil {
+				return err
+			}
+
+			c := serial_util.NewConn(port, l.addr, cancel)
+			c = metrics.WrapConn(l.options.Service, c)
+			c = limiter.WrapConn(l.options.TrafficLimiter, c)
+
+			l.cqueue <- c
+
+			return nil
+		}()
+		if err != nil {
+			l.logger.Error(err)
+			cancel()
+		}
+
+		select {
+		case <-ctx.Done():
+		case <-l.closed:
+			return
+		}
+
+		time.Sleep(time.Second)
+	}
+}