Feature: experimental support snell

adapters/outbound/snell.go

@@ -0,0 +1,71 @@
+package adapters
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+
+	"github.com/Dreamacro/clash/common/structure"
+	obfs "github.com/Dreamacro/clash/component/simple-obfs"
+	"github.com/Dreamacro/clash/component/snell"
+	C "github.com/Dreamacro/clash/constant"
+)
+
+type Snell struct {
+	*Base
+	server     string
+	psk        []byte
+	obfsOption *simpleObfsOption
+}
+
+type SnellOption struct {
+	Name     string                 `proxy:"name"`
+	Server   string                 `proxy:"server"`
+	Port     int                    `proxy:"port"`
+	Psk      string                 `proxy:"psk"`
+	ObfsOpts map[string]interface{} `proxy:"obfs-opts,omitempty"`
+}
+
+func (s *Snell) Dial(metadata *C.Metadata) (C.Conn, error) {
+	c, err := dialTimeout("tcp", s.server, tcpTimeout)
+	if err != nil {
+		return nil, fmt.Errorf("%s connect error: %s", s.server, err.Error())
+	}
+	tcpKeepAlive(c)
+	switch s.obfsOption.Mode {
+	case "tls":
+		c = obfs.NewTLSObfs(c, s.obfsOption.Host)
+	case "http":
+		_, port, _ := net.SplitHostPort(s.server)
+		c = obfs.NewHTTPObfs(c, s.obfsOption.Host, port)
+	}
+	c = snell.StreamConn(c, s.psk)
+	port, _ := strconv.Atoi(metadata.DstPort)
+	err = snell.WriteHeader(c, metadata.String(), uint(port))
+	return newConn(c, s), err
+}
+
+func NewSnell(option SnellOption) (*Snell, error) {
+	server := 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: %s", server, err.Error())
+	}
+
+	if obfsOption.Mode != "tls" && obfsOption.Mode != "http" {
+		return nil, fmt.Errorf("snell %s obfs mode error: %s", server, obfsOption.Mode)
+	}
+
+	return &Snell{
+		Base: &Base{
+			name: option.Name,
+			tp:   C.Snell,
+		},
+		server:     server,
+		psk:        psk,
+		obfsOption: obfsOption,
+	}, nil
+}