Add generic relayer interface

relayer/relayer.go

@@ -0,0 +1,47 @@
+// Copyright (c) 2024 Kai Luo <[email protected]>. All rights reserved.
+
+package relayer
+
+import (
+	"log"
+	"net"
+
+	"github.com/bzEq/bx/core"
+)
+
+type Options struct {
+	LocalAddr string
+	NextHops  []string
+}
+
+type Relayer struct {
+	fe Frontend
+	be Backend
+}
+
+type Frontend interface {
+	Accept() (core.Port, net.Addr, error)
+}
+
+type Backend interface {
+	Dial(addr net.Addr) (core.Port, error)
+}
+
+func (self *Relayer) Relay() error {
+	for {
+		fp, addr, err := self.fe.Accept()
+		if err != nil {
+			return err
+		}
+		go func(fp core.Port, addr net.Addr) {
+			defer fp.Close()
+			bp, err := self.be.Dial(addr)
+			if err != nil {
+				log.Println(err)
+				return
+			}
+			defer bp.Close()
+			core.RunSimpleSwitch(fp, bp)
+		}(fp, addr)
+	}
+}