add binder for connector

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
+}