add router handler & connector

connector/relay/conn.go

@@ -192,14 +192,13 @@ func (c *bindUDPConn) Write(b []byte) (n int, err error) {
 		return
 	}
 
-	// 2-byte data length header
-	var bh [2]byte
-	binary.BigEndian.PutUint16(bh[:], uint16(len(b)))
-	_, err = c.Conn.Write(bh[:])
-	if err != nil {
-		return
-	}
-	return c.Conn.Write(b)
+	buf := bufpool.Get(len(b) + 2)
+	defer bufpool.Put(buf)
+
+	binary.BigEndian.PutUint16(buf[:2], uint16(len(b)))
+	n = copy(buf[2:], b)
+
+	return c.Conn.Write(buf)
 }
 
 func (c *bindUDPConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {

connector/router/conn.go

@@ -0,0 +1,73 @@
+package tunnel
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"net"
+
+	"github.com/go-gost/core/common/bufpool"
+	"github.com/go-gost/relay"
+	xrelay "github.com/go-gost/x/internal/util/relay"
+)
+
+type packetConn struct {
+	net.Conn
+}
+
+func (c *packetConn) Read(b []byte) (n int, err error) {
+	var bb [2]byte
+	_, err = io.ReadFull(c.Conn, bb[:])
+	if err != nil {
+		return
+	}
+
+	dlen := int(binary.BigEndian.Uint16(bb[:]))
+	if len(b) >= dlen {
+		return io.ReadFull(c.Conn, b[:dlen])
+	}
+
+	buf := bufpool.Get(dlen)
+	defer bufpool.Put(buf)
+
+	n, err = io.ReadFull(c.Conn, buf)
+	copy(b, buf[:n])
+
+	return
+}
+
+func (c *packetConn) Write(b []byte) (n int, err error) {
+	if len(b) > math.MaxUint16 {
+		err = errors.New("write: data maximum exceeded")
+		return
+	}
+
+	buf := bufpool.Get(len(b) + 2)
+	defer bufpool.Put(buf)
+
+	binary.BigEndian.PutUint16(buf[:2], uint16(len(b)))
+	n = copy(buf[2:], b)
+
+	return c.Conn.Write(buf)
+}
+
+func readResponse(r io.Reader) (err error) {
+	resp := relay.Response{}
+	_, err = resp.ReadFrom(r)
+	if err != nil {
+		return
+	}
+
+	if resp.Version != relay.Version1 {
+		err = relay.ErrBadVersion
+		return
+	}
+
+	if resp.Status != relay.StatusOK {
+		err = fmt.Errorf("%d %s", resp.Status, xrelay.StatusText(resp.Status))
+		return
+	}
+	return nil
+}

connector/router/connector.go

@@ -0,0 +1,117 @@
+package tunnel
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/go-gost/core/connector"
+	md "github.com/go-gost/core/metadata"
+	"github.com/go-gost/relay"
+	ctxvalue "github.com/go-gost/x/ctx"
+	"github.com/go-gost/x/registry"
+)
+
+func init() {
+	registry.ConnectorRegistry().Register("router", NewConnector)
+}
+
+type routerConnector struct {
+	md      metadata
+	options connector.Options
+}
+
+func NewConnector(opts ...connector.Option) connector.Connector {
+	options := connector.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &routerConnector{
+		options: options,
+	}
+}
+
+func (c *routerConnector) Init(md md.Metadata) (err error) {
+	return c.parseMetadata(md)
+}
+
+func (c *routerConnector) Connect(ctx context.Context, conn net.Conn, network, address string, opts ...connector.ConnectOption) (net.Conn, error) {
+	log := c.options.Logger.WithFields(map[string]any{
+		"remote":  conn.RemoteAddr().String(),
+		"local":   conn.LocalAddr().String(),
+		"network": network,
+		"address": address,
+		"sid":     string(ctxvalue.SidFromContext(ctx)),
+	})
+	log.Debugf("connect %s/%s", address, network)
+
+	if c.md.connectTimeout > 0 {
+		conn.SetDeadline(time.Now().Add(c.md.connectTimeout))
+		defer conn.SetDeadline(time.Time{})
+	}
+
+	req := relay.Request{
+		Version: relay.Version1,
+		Cmd:     relay.CmdAssociate,
+	}
+
+	if c.options.Auth != nil {
+		pwd, _ := c.options.Auth.Password()
+		req.Features = append(req.Features, &relay.UserAuthFeature{
+			Username: c.options.Auth.Username(),
+			Password: pwd,
+		})
+	}
+
+	switch network {
+	case "udp":
+		req.Features = append(req.Features, &relay.NetworkFeature{
+			Network: relay.NetworkUDP,
+		})
+
+	case "ip":
+		req.Features = append(req.Features, &relay.NetworkFeature{
+			Network: relay.NetworkIP,
+		})
+	}
+
+	srcAddr := conn.LocalAddr().String()
+	if v := ctxvalue.ClientAddrFromContext(ctx); v != "" {
+		srcAddr = string(v)
+	}
+
+	af := &relay.AddrFeature{}
+	af.ParseFrom(srcAddr)
+	req.Features = append(req.Features, af) // src address
+
+	af = &relay.AddrFeature{}
+	af.ParseFrom(address)
+	req.Features = append(req.Features, af) // dst address
+
+	req.Features = append(req.Features, &relay.TunnelFeature{
+		ID: c.md.routerID,
+	})
+
+	if _, err := req.WriteTo(conn); err != nil {
+		return nil, err
+	}
+	// drain the response
+	if err := readResponse(conn); err != nil {
+		return nil, err
+	}
+
+	switch network {
+	case "udp", "ip":
+		conn = &packetConn{
+			Conn: conn,
+		}
+	default:
+		err := fmt.Errorf("network %s is unsupported", network)
+		log.Error(err)
+		return nil, err
+	}
+
+	return conn, nil
+}

connector/router/metadata.go

@@ -0,0 +1,42 @@
+package tunnel
+
+import (
+	"errors"
+	"time"
+
+	mdata "github.com/go-gost/core/metadata"
+	"github.com/go-gost/relay"
+	mdutil "github.com/go-gost/x/metadata/util"
+	"github.com/google/uuid"
+)
+
+var (
+	ErrInvalidRouterID = errors.New("router: invalid router ID")
+)
+
+type metadata struct {
+	connectTimeout time.Duration
+	routerID       relay.TunnelID
+}
+
+func (c *routerConnector) parseMetadata(md mdata.Metadata) (err error) {
+	c.md.connectTimeout = mdutil.GetDuration(md, "connectTimeout")
+
+	if s := mdutil.GetString(md, "router.id"); s != "" {
+		uuid, err := uuid.Parse(s)
+		if err != nil {
+			return err
+		}
+		c.md.routerID = relay.NewTunnelID(uuid[:])
+	}
+
+	if c.md.routerID.IsZero() {
+		uuid, err := uuid.NewUUID()
+		if err != nil {
+			return err
+		}
+		c.md.routerID = relay.NewTunnelID(uuid[:])
+	}
+
+	return
+}

connector/tunnel/conn.go

@@ -130,14 +130,13 @@ func (c *bindUDPConn) Write(b []byte) (n int, err error) {
 		return
 	}
 
-	// 2-byte data length header
-	var bh [2]byte
-	binary.BigEndian.PutUint16(bh[:], uint16(len(b)))
-	_, err = c.Conn.Write(bh[:])
-	if err != nil {
-		return
-	}
-	return c.Conn.Write(b)
+	buf := bufpool.Get(len(b) + 2)
+	defer bufpool.Put(buf)
+
+	binary.BigEndian.PutUint16(buf[:2], uint16(len(b)))
+	n = copy(buf[2:], b)
+
+	return c.Conn.Write(buf)
 }
 
 func (c *bindUDPConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {