Add basic blacklist functionality

ctrl/config.go

@@ -25,6 +25,7 @@ type Suo5Config struct {
 	DisableGzip      bool           `json:"disable_gzip"`
 	EnableCookiejar  bool           `json:"enable_cookiejar"`
 	TestExit         string         `json:"-"`
+	ExcludeDomain    []string       `json:"exclude_domain"`
 
 	Offset                  int                                  `json:"-"`
 	Header                  http.Header                          `json:"-"`

ctrl/handler.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"slices"
 	"strconv"
 	"sync"
 	"time"
@@ -52,6 +53,12 @@ func (m *socks5Handler) Handle(conn net.Conn) error {
 		return err
 	}
 
+	if slices.Contains(m.config.ExcludeDomain, req.Addr.Host) {
+		defer conn.Close()
+		log.Infof("drop connection to %s", req.Addr.Host)
+		return nil
+	}
+
 	log.Infof("start connection to %s", req.Addr.String())
 	switch req.Cmd {
 	case gosocks5.CmdConnect:
@@ -258,7 +265,6 @@ func marshal(m map[string][]byte) []byte {
 		buf.Write(v)
 	}
 	return buf.Bytes()
-
 }
 
 func unmarshal(bs []byte) (map[string][]byte, error) {

main.go

@@ -119,6 +119,11 @@ func main() {
 			Usage:   "test a real connection, if success exit(0), else exit(1)",
 			Hidden:  true,
 		},
+		&cli.StringSliceFlag{
+			Name:    "exclude_domain",
+			Aliases: []string{"E"},
+			Usage:   "Exclude certain domain name for proxy, ex -E 'portswigger.net'",
+		},
 	}
 	app.Before = func(c *cli.Context) error {
 		if c.Bool("debug") {
@@ -152,6 +157,7 @@ func Action(c *cli.Context) error {
 	noGzip := c.Bool("no-gzip")
 	useJar := c.Bool("jar")
 	testExit := c.String("test-exit")
+	exclude := c.StringSlice("exclude_domain")
 
 	var username, password string
 	if auth == "" {
@@ -195,6 +201,7 @@ func Action(c *cli.Context) error {
 		DisableGzip:      noGzip,
 		EnableCookiejar:  useJar,
 		TestExit:         testExit,
+		ExcludeDomain:    exclude,
 	}
 	ctx, cancel := signalCtx()
 	defer cancel()