Feature: HTTP proxy support

engine/parse.go

@@ -50,8 +50,10 @@ func parseProxy(s string) (proxy.Proxy, error) {
 		return proxy.NewDirect(), nil
 	case proto.Reject.String():
 		return proxy.NewReject(), nil
+	case proto.HTTP.String():
+		return proxy.NewHTTP(parseAddrUser(u))
 	case proto.Socks5.String():
-		return proxy.NewSocks5(parseSocks(u))
+		return proxy.NewSocks5(parseAddrUser(u))
 	case proto.Shadowsocks.String():
 		return proxy.NewShadowsocks(parseShadowsocks(u))
 	default:
@@ -59,7 +61,7 @@ func parseProxy(s string) (proxy.Proxy, error) {
 	}
 }
 
-func parseSocks(u *url.URL) (address, username, password string) {
+func parseAddrUser(u *url.URL) (address, username, password string) {
 	address = u.Host
 	username = u.User.Username()
 	password, _ = u.User.Password()

proxy/http.go

@@ -0,0 +1,97 @@
+package proxy
+
+// Ref: https://github.com/Dreamacro/clash/adapter/outbound/http
+
+import (
+	"bufio"
+	"context"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+
+	"github.com/xjasonlyu/tun2socks/component/dialer"
+	M "github.com/xjasonlyu/tun2socks/constant"
+	"github.com/xjasonlyu/tun2socks/proxy/proto"
+)
+
+type HTTP struct {
+	*Base
+
+	user string
+	pass string
+}
+
+func NewHTTP(addr, user, pass string) (*HTTP, error) {
+	return &HTTP{
+		Base: &Base{
+			addr:  addr,
+			proto: proto.HTTP,
+		},
+		user: user,
+		pass: pass,
+	}, nil
+}
+
+func (h *HTTP) DialContext(ctx context.Context, metadata *M.Metadata) (c net.Conn, err error) {
+	c, err = dialer.DialContext(ctx, "tcp", h.Addr())
+	if err != nil {
+		return nil, fmt.Errorf("connect to %s: %w", h.Addr(), err)
+	}
+	setKeepAlive(c)
+
+	defer safeConnClose(c, err)
+
+	err = h.shakeHand(metadata, c)
+	return
+}
+
+func (h *HTTP) shakeHand(metadata *M.Metadata, rw io.ReadWriter) error {
+	addr := metadata.DestinationAddress()
+	req := &http.Request{
+		Method: http.MethodConnect,
+		URL: &url.URL{
+			Host: addr,
+		},
+		Host: addr,
+		Header: http.Header{
+			"Proxy-Connection": []string{"Keep-Alive"},
+		},
+	}
+
+	if h.user != "" && h.pass != "" {
+		auth := h.user + ":" + h.pass
+		req.Header.Add("Proxy-Authorization",
+			fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString([]byte(auth))))
+	}
+
+	if err := req.Write(rw); err != nil {
+		return err
+	}
+
+	resp, err := http.ReadResponse(bufio.NewReader(rw), req)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode == http.StatusOK {
+		return nil
+	}
+
+	if resp.StatusCode == http.StatusProxyAuthRequired {
+		return errors.New("HTTP need auth")
+	}
+
+	if resp.StatusCode == http.StatusMethodNotAllowed {
+		return errors.New("CONNECT method not allowed by proxy")
+	}
+
+	if resp.StatusCode >= http.StatusInternalServerError {
+		return errors.New(resp.Status)
+	}
+
+	return fmt.Errorf("HTTP connect status code: %d", resp.StatusCode)
+}

proxy/proto/proto.go

@@ -5,8 +5,9 @@ import "fmt"
 const (
 	Direct Proto = iota
 	Reject
-	Shadowsocks
+	HTTP
 	Socks5
+	Shadowsocks
 )
 
 type Proto uint8
@@ -17,10 +18,12 @@ func (proto Proto) String() string {
 		return "direct"
 	case Reject:
 		return "reject"
-	case Shadowsocks:
-		return "ss"
+	case HTTP:
+		return "http"
 	case Socks5:
 		return "socks5"
+	case Shadowsocks:
+		return "ss"
 	default:
 		return fmt.Sprintf("proto(%d)", proto)
 	}