add binder for connector

pkg/connector/relay/conn.go

@@ -0,0 +1,117 @@
+package relay
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"sync"
+
+	"github.com/go-gost/gost/pkg/logger"
+	"github.com/go-gost/relay"
+)
+
+type conn struct {
+	net.Conn
+	udp        bool
+	wbuf       bytes.Buffer
+	once       sync.Once
+	headerSent bool
+	logger     logger.Logger
+}
+
+func (c *conn) Read(b []byte) (n int, err error) {
+	c.once.Do(func() {
+		resp := relay.Response{}
+		_, err = resp.ReadFrom(c.Conn)
+		if err != nil {
+			return
+		}
+		if resp.Version != relay.Version1 {
+			err = relay.ErrBadVersion
+			return
+		}
+		if resp.Status != relay.StatusOK {
+			err = fmt.Errorf("status %d", resp.Status)
+			return
+		}
+	})
+
+	if err != nil {
+		return
+	}
+
+	if !c.udp {
+		return c.Conn.Read(b)
+	}
+
+	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 := make([]byte, dlen)
+	_, err = io.ReadFull(c.Conn, buf)
+	n = copy(b, buf)
+	return
+}
+
+func (c *conn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
+	n, err = c.Read(b)
+	addr = c.Conn.RemoteAddr()
+	return
+}
+
+func (c *conn) Write(b []byte) (n int, err error) {
+	if len(b) > 0xFFFF {
+		err = errors.New("write: data maximum exceeded")
+		return
+	}
+	n = len(b) // force byte length consistent
+	if c.wbuf.Len() > 0 {
+		if c.udp {
+			var bb [2]byte
+			binary.BigEndian.PutUint16(bb[:2], uint16(len(b)))
+			c.wbuf.Write(bb[:])
+			c.headerSent = true
+		}
+		c.wbuf.Write(b) // append the data to the cached header
+		// _, err = c.Conn.Write(c.wbuf.Bytes())
+		// c.wbuf.Reset()
+		_, err = c.wbuf.WriteTo(c.Conn)
+		return
+	}
+
+	if !c.udp {
+		return c.Conn.Write(b)
+	}
+	if !c.headerSent {
+		c.headerSent = true
+		b2 := make([]byte, len(b)+2)
+		copy(b2, b)
+		_, err = c.Conn.Write(b2)
+		return
+	}
+	nsize := 2 + len(b)
+	var buf []byte
+	if nsize <= mediumBufferSize {
+		buf = mPool.Get().([]byte)
+		defer mPool.Put(buf)
+	} else {
+		buf = make([]byte, nsize)
+	}
+	binary.BigEndian.PutUint16(buf[:2], uint16(len(b)))
+	n = copy(buf[2:], b)
+	_, err = c.Conn.Write(buf[:nsize])
+	return
+}
+
+func (c *relayConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
+	return c.Write(b)
+}

pkg/connector/relay/connector.go

@@ -0,0 +1,101 @@
+package relay
+
+import (
+	"context"
+	"net"
+	"strconv"
+	"time"
+
+	"github.com/go-gost/gost/pkg/connector"
+	"github.com/go-gost/gost/pkg/logger"
+	md "github.com/go-gost/gost/pkg/metadata"
+	"github.com/go-gost/gost/pkg/registry"
+	"github.com/go-gost/relay"
+)
+
+func init() {
+	registry.RegiserConnector("relay", NewConnector)
+}
+
+type relayConnector struct {
+	logger logger.Logger
+	md     metadata
+}
+
+func NewConnector(opts ...connector.Option) connector.Connector {
+	options := &connector.Options{}
+	for _, opt := range opts {
+		opt(options)
+	}
+
+	return &relayConnector{
+		logger: options.Logger,
+	}
+}
+
+func (c *relayConnector) Init(md md.Metadata) (err error) {
+	return c.parseMetadata(md)
+}
+
+func (c *relayConnector) Connect(ctx context.Context, conn net.Conn, network, address string, opts ...connector.ConnectOption) (net.Conn, error) {
+	c.logger = c.logger.WithFields(map[string]interface{}{
+		"remote":  conn.RemoteAddr().String(),
+		"local":   conn.LocalAddr().String(),
+		"network": network,
+		"address": address,
+	})
+	c.logger.Infof("connect: %s/%s", address, network)
+
+	if c.md.connectTimeout > 0 {
+		conn.SetDeadline(time.Now().Add(c.md.connectTimeout))
+		defer conn.SetDeadline(time.Time{})
+	}
+
+	var udpMode bool
+	if network == "udp" || network == "udp4" || network == "udp6" {
+		udpMode = true
+	}
+
+	req := relay.Request{
+		Version: relay.Version1,
+	}
+	if udpMode {
+		req.Flags |= relay.FUDP
+	}
+
+	if c.md.user != nil {
+		pwd, _ := c.md.user.Password()
+		req.Features = append(req.Features, &relay.UserAuthFeature{
+			Username: c.md.user.Username(),
+			Password: pwd,
+		})
+	}
+
+	if address != "" {
+		host, port, _ := net.SplitHostPort(address)
+		nport, _ := strconv.ParseUint(port, 10, 16)
+		if host == "" {
+			host = net.IPv4zero.String()
+		}
+
+		if nport > 0 {
+			var atype uint8
+			ip := net.ParseIP(host)
+			if ip == nil {
+				atype = relay.AddrDomain
+			} else if ip.To4() == nil {
+				atype = relay.AddrIPv6
+			} else {
+				atype = relay.AddrIPv4
+			}
+
+			req.Features = append(req.Features, &relay.TargetAddrFeature{
+				AType: atype,
+				Host:  host,
+				Port:  uint16(nport),
+			})
+		}
+	}
+
+	return conn, nil
+}

pkg/connector/relay/metadata.go

@@ -0,0 +1,36 @@
+package relay
+
+import (
+	"net/url"
+	"strings"
+	"time"
+
+	md "github.com/go-gost/gost/pkg/metadata"
+)
+
+type metadata struct {
+	connectTimeout time.Duration
+	user           *url.Userinfo
+	nodelay        bool
+}
+
+func (c *relayConnector) parseMetadata(md md.Metadata) (err error) {
+	const (
+		auth           = "auth"
+		connectTimeout = "connectTimeout"
+		nodelay        = "nodelay"
+	)
+
+	if v := md.GetString(auth); v != "" {
+		ss := strings.SplitN(v, ":", 2)
+		if len(ss) == 1 {
+			c.md.user = url.User(ss[0])
+		} else {
+			c.md.user = url.UserPassword(ss[0], ss[1])
+		}
+	}
+	c.md.connectTimeout = md.GetDuration(connectTimeout)
+	c.md.nodelay = md.GetBool(nodelay)
+
+	return
+}