initial commit

connector/ss/udp/connector.go

@@ -0,0 +1,95 @@
+package ss
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/go-gost/gost/v3/pkg/connector"
+	md "github.com/go-gost/gost/v3/pkg/metadata"
+	"github.com/go-gost/gost/v3/pkg/registry"
+	"github.com/go-gost/x/internal/util/relay"
+	"github.com/go-gost/x/internal/util/ss"
+	"github.com/shadowsocks/go-shadowsocks2/core"
+)
+
+func init() {
+	registry.ConnectorRegistry().Register("ssu", NewConnector)
+}
+
+type ssuConnector struct {
+	cipher  core.Cipher
+	md      metadata
+	options connector.Options
+}
+
+func NewConnector(opts ...connector.Option) connector.Connector {
+	options := connector.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	return &ssuConnector{
+		options: options,
+	}
+}
+
+func (c *ssuConnector) Init(md md.Metadata) (err error) {
+	if err = c.parseMetadata(md); err != nil {
+		return
+	}
+
+	if c.options.Auth != nil {
+		method := c.options.Auth.Username()
+		password, _ := c.options.Auth.Password()
+		c.cipher, err = ss.ShadowCipher(method, password, c.md.key)
+	}
+
+	return
+}
+
+func (c *ssuConnector) 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,
+	})
+	log.Infof("connect %s/%s", address, network)
+
+	switch network {
+	case "udp", "udp4", "udp6":
+	default:
+		err := fmt.Errorf("network %s is unsupported", network)
+		log.Error(err)
+		return nil, err
+	}
+
+	if c.md.connectTimeout > 0 {
+		conn.SetDeadline(time.Now().Add(c.md.connectTimeout))
+		defer conn.SetDeadline(time.Time{})
+	}
+
+	taddr, _ := net.ResolveUDPAddr(network, address)
+	if taddr == nil {
+		taddr = &net.UDPAddr{}
+	}
+
+	pc, ok := conn.(net.PacketConn)
+	if ok {
+		if c.cipher != nil {
+			pc = c.cipher.PacketConn(pc)
+		}
+
+		// standard UDP relay
+		return ss.UDPClientConn(pc, conn.RemoteAddr(), taddr, c.md.bufferSize), nil
+	}
+
+	if c.cipher != nil {
+		conn = ss.ShadowConn(c.cipher.StreamConn(conn), nil)
+	}
+
+	// UDP over TCP
+	return relay.UDPTunClientConn(conn, taddr), nil
+}