add tunnel handler and connector

handler/tunnel/bind.go

@@ -0,0 +1,67 @@
+package tunnel
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/hex"
+	"net"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/relay"
+	"github.com/go-gost/x/internal/util/mux"
+	"github.com/google/uuid"
+)
+
+func (h *tunnelHandler) handleBind(ctx context.Context, conn net.Conn, network, address string, tunnelID relay.TunnelID, log logger.Logger) (err error) {
+	resp := relay.Response{
+		Version: relay.Version1,
+		Status:  relay.StatusOK,
+	}
+
+	uuid, err := uuid.NewRandom()
+	if err != nil {
+		resp.Status = relay.StatusInternalServerError
+		resp.WriteTo(conn)
+		return
+	}
+	connectorID := relay.NewConnectorID(uuid[:])
+	if network == "udp" {
+		connectorID = relay.NewUDPConnectorID(uuid[:])
+	}
+
+	addr := address
+	if host, port, _ := net.SplitHostPort(addr); host == "" {
+		v := md5.Sum([]byte(tunnelID.String()))
+		host = hex.EncodeToString(v[:8])
+		addr = net.JoinHostPort(host, port)
+	}
+	af := &relay.AddrFeature{}
+	err = af.ParseFrom(addr)
+	if err != nil {
+		log.Warn(err)
+	}
+	resp.Features = append(resp.Features, af,
+		&relay.TunnelFeature{
+			ID: connectorID.ID(),
+		},
+	)
+	resp.WriteTo(conn)
+
+	// Upgrade connection to multiplex session.
+	session, err := mux.ClientSession(conn)
+	if err != nil {
+		return
+	}
+
+	h.pool.Add(tunnelID, NewConnector(connectorID, session))
+	if h.md.ingress != nil {
+		h.md.ingress.Set(ctx, addr, tunnelID.String())
+	}
+	if h.recorder.Recorder != nil {
+		h.recorder.Recorder.Record(ctx, tunnelID[:])
+	}
+
+	log.Debugf("%s/%s: tunnel=%s, connector=%s established", addr, network, tunnelID, connectorID)
+
+	return
+}