Style: code style

adapter/outbound/snell.go

@@ -0,0 +1,135 @@
+package outbound
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"strconv"
+
+	"github.com/Dreamacro/clash/common/structure"
+	"github.com/Dreamacro/clash/component/dialer"
+	C "github.com/Dreamacro/clash/constant"
+	obfs "github.com/Dreamacro/clash/transport/simple-obfs"
+	"github.com/Dreamacro/clash/transport/snell"
+)
+
+type Snell struct {
+	*Base
+	psk        []byte
+	pool       *snell.Pool
+	obfsOption *simpleObfsOption
+	version    int
+}
+
+type SnellOption struct {
+	Name     string                 `proxy:"name"`
+	Server   string                 `proxy:"server"`
+	Port     int                    `proxy:"port"`
+	Psk      string                 `proxy:"psk"`
+	Version  int                    `proxy:"version,omitempty"`
+	ObfsOpts map[string]interface{} `proxy:"obfs-opts,omitempty"`
+}
+
+type streamOption struct {
+	psk        []byte
+	version    int
+	addr       string
+	obfsOption *simpleObfsOption
+}
+
+func streamConn(c net.Conn, option streamOption) *snell.Snell {
+	switch option.obfsOption.Mode {
+	case "tls":
+		c = obfs.NewTLSObfs(c, option.obfsOption.Host)
+	case "http":
+		_, port, _ := net.SplitHostPort(option.addr)
+		c = obfs.NewHTTPObfs(c, option.obfsOption.Host, port)
+	}
+	return snell.StreamConn(c, option.psk, option.version)
+}
+
+// StreamConn implements C.ProxyAdapter
+func (s *Snell) StreamConn(c net.Conn, metadata *C.Metadata) (net.Conn, error) {
+	c = streamConn(c, streamOption{s.psk, s.version, s.addr, s.obfsOption})
+	port, _ := strconv.Atoi(metadata.DstPort)
+	err := snell.WriteHeader(c, metadata.String(), uint(port), s.version)
+	return c, err
+}
+
+// DialContext implements C.ProxyAdapter
+func (s *Snell) DialContext(ctx context.Context, metadata *C.Metadata) (_ C.Conn, err error) {
+	if s.version == snell.Version2 {
+		c, err := s.pool.Get()
+		if err != nil {
+			return nil, err
+		}
+
+		port, _ := strconv.Atoi(metadata.DstPort)
+		if err = snell.WriteHeader(c, metadata.String(), uint(port), s.version); err != nil {
+			c.Close()
+			return nil, err
+		}
+		return NewConn(c, s), err
+	}
+
+	c, err := dialer.DialContext(ctx, "tcp", s.addr)
+	if err != nil {
+		return nil, fmt.Errorf("%s connect error: %w", s.addr, err)
+	}
+	tcpKeepAlive(c)
+
+	defer safeConnClose(c, err)
+
+	c, err = s.StreamConn(c, metadata)
+	return NewConn(c, s), err
+}
+
+func NewSnell(option SnellOption) (*Snell, error) {
+	addr := net.JoinHostPort(option.Server, strconv.Itoa(option.Port))
+	psk := []byte(option.Psk)
+
+	decoder := structure.NewDecoder(structure.Option{TagName: "obfs", WeaklyTypedInput: true})
+	obfsOption := &simpleObfsOption{Host: "bing.com"}
+	if err := decoder.Decode(option.ObfsOpts, obfsOption); err != nil {
+		return nil, fmt.Errorf("snell %s initialize obfs error: %w", addr, err)
+	}
+
+	switch obfsOption.Mode {
+	case "tls", "http", "":
+		break
+	default:
+		return nil, fmt.Errorf("snell %s obfs mode error: %s", addr, obfsOption.Mode)
+	}
+
+	// backward compatible
+	if option.Version == 0 {
+		option.Version = snell.DefaultSnellVersion
+	}
+	if option.Version != snell.Version1 && option.Version != snell.Version2 {
+		return nil, fmt.Errorf("snell version error: %d", option.Version)
+	}
+
+	s := &Snell{
+		Base: &Base{
+			name: option.Name,
+			addr: addr,
+			tp:   C.Snell,
+		},
+		psk:        psk,
+		obfsOption: obfsOption,
+		version:    option.Version,
+	}
+
+	if option.Version == snell.Version2 {
+		s.pool = snell.NewPool(func(ctx context.Context) (*snell.Snell, error) {
+			c, err := dialer.DialContext(ctx, "tcp", addr)
+			if err != nil {
+				return nil, err
+			}
+
+			tcpKeepAlive(c)
+			return streamConn(c, streamOption{psk, option.Version, addr, obfsOption}), nil
+		})
+	}
+	return s, nil
+}