add ssu connector

pkg/connector/ssu/connector.go

@@ -0,0 +1,105 @@
+package ssu
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/go-gost/gost/pkg/connector"
+	"github.com/go-gost/gost/pkg/internal/utils/socks"
+	"github.com/go-gost/gost/pkg/internal/utils/ss"
+	"github.com/go-gost/gost/pkg/logger"
+	md "github.com/go-gost/gost/pkg/metadata"
+	"github.com/go-gost/gost/pkg/registry"
+)
+
+func init() {
+	registry.RegiserConnector("ssu", NewConnector)
+}
+
+type ssuConnector struct {
+	md     metadata
+	logger logger.Logger
+}
+
+func NewConnector(opts ...connector.Option) connector.Connector {
+	options := &connector.Options{}
+	for _, opt := range opts {
+		opt(options)
+	}
+
+	return &ssuConnector{
+		logger: options.Logger,
+	}
+}
+
+func (c *ssuConnector) Init(md md.Metadata) (err error) {
+	return c.parseMetadata(md)
+}
+
+func (c *ssuConnector) 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,
+	})
+
+	switch network {
+	case "udp", "udp4", "udp6":
+	default:
+		err := fmt.Errorf("network %s unsupported, should be udp, udp4 or udp6", network)
+		c.logger.Error(err)
+		return nil, err
+	}
+
+	c.logger.Info("connect: ", address)
+
+	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.md.cipher != nil {
+			pc = c.md.cipher.PacketConn(pc)
+		}
+
+		return ss.UDPClientConn(pc, conn.RemoteAddr(), taddr, c.md.bufferSize), nil
+	}
+
+	return socks.UDPTunClientConn(conn, taddr), nil
+}
+
+func (c *ssuConnector) parseMetadata(md md.Metadata) (err error) {
+	c.md.cipher, err = ss.ShadowCipher(
+		md.GetString(method),
+		md.GetString(password),
+		md.GetString(key),
+	)
+	if err != nil {
+		return
+	}
+
+	c.md.connectTimeout = md.GetDuration(connectTimeout)
+	c.md.bufferSize = md.GetInt(bufferSize)
+	if c.md.bufferSize > 0 {
+		if c.md.bufferSize < 512 {
+			c.md.bufferSize = 512
+		}
+		if c.md.bufferSize > 65*1024 {
+			c.md.bufferSize = 65 * 1024
+		}
+	} else {
+		c.md.bufferSize = 4096
+	}
+
+	return
+}

pkg/connector/ssu/metadata.go

@@ -0,0 +1,21 @@
+package ssu
+
+import (
+	"time"
+
+	"github.com/shadowsocks/go-shadowsocks2/core"
+)
+
+const (
+	method         = "method"
+	password       = "password"
+	key            = "key"
+	connectTimeout = "timeout"
+	bufferSize     = "bufferSize"
+)
+
+type metadata struct {
+	cipher         core.Cipher
+	connectTimeout time.Duration
+	bufferSize     int
+}