add entrypoint for router handler

handler/router/entrypoint.go

@@ -0,0 +1,62 @@
+package router
+
+import (
+	"bytes"
+
+	"github.com/go-gost/core/common/bufpool"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/relay"
+)
+
+func (h *routerHandler) handleEntrypoint(log logger.Logger) error {
+	buf := bufpool.Get(h.md.bufferSize)
+	defer bufpool.Put(buf)
+
+	for {
+		err := func() error {
+			n, addr, err := h.epConn.ReadFrom(buf)
+			if err != nil {
+				return err
+			}
+
+			req := relay.Request{}
+			nn, err := req.ReadFrom(bytes.NewReader(buf[:n]))
+			if err != nil {
+				return nil
+			}
+			if req.Cmd != relay.CmdAssociate {
+				return nil
+			}
+
+			var routerID relay.TunnelID
+			var gateway string
+
+			for _, f := range req.Features {
+				switch f.Type() {
+				case relay.FeatureTunnel:
+					if feature, _ := f.(*relay.TunnelFeature); feature != nil {
+						routerID = feature.ID
+					}
+				case relay.FeatureAddr:
+					if feature, _ := f.(*relay.AddrFeature); feature != nil {
+						gateway = feature.Host
+					}
+				}
+			}
+
+			log.Tracef("redirect from %s to %s@%s", addr, gateway, routerID)
+
+			if c := h.pool.Get(routerID, gateway); c != nil {
+				if w := c.Writer(); w != nil {
+					w.Write(buf[nn:])
+				}
+			}
+
+			return nil
+		}()
+
+		if err != nil {
+			return err
+		}
+	}
+}