添加 bash id, 避免链接到不正确的服务器

Author: shynome

bash/bash.go

@@ -29,6 +29,7 @@ type Bash struct {
 
 	IDGenerator IDGenerator
 	VERSION     string
+	ID          string
 }
 
 type ID interface {
@@ -54,6 +55,7 @@ func (sh *Bash) Serve(l net.Listener) (err error) {
 	if sh.IDGenerator == nil {
 		return fmt.Errorf("IDGenerator is required")
 	}
+	sh.ID = fmt.Sprintf("lcode-hub@%s:%s", sh.VERSION, uuid.NewString())
 	sh.listener = l
 	for {
 		conn := To1(l.Accept())
@@ -74,6 +76,11 @@ func (sh *Bash) serve(conn net.Conn) (err error) {
 		return
 	}
 	switch v := string(header[0]); v {
+	case "-":
+		defer conn.Close()
+		if string(header) == "-1" {
+			io.WriteString(conn, sh.ID+"\n")
+		}
 	case "0":
 		sh.Connect(r, conn)
 	case "1":
@@ -121,7 +128,7 @@ func (sh *Bash) Connect(r *bufio.Reader, conn net.Conn) (err error) {
 
 	c := webdav.NewClient(conn)
 
-	To(c.Open(r, sh.VERSION))
+	To(c.Open(r, sh.VERSION, sh.ID))
 	defer c.Close()
 	idRaw := strings.ToLower(c.ID)
 

bash/webdav/client.go

@@ -63,12 +63,12 @@ func (c *Client) log(err error) {
 	}
 	c.Logger(nil, err)
 }
-func (c *Client) Open(r *bufio.Reader, version string) (err error) {
+func (c *Client) Open(r *bufio.Reader, version string, id string) (err error) {
 	defer err2.Handle(&err, func() {
 		c.log(fmt.Errorf("bash client start failed: %w", err))
 	})
 	To(c.parseArgs(r, version))
-	To(c.initServerAddr())
+	To(c.initServerAddr(r, id))
 	To(c.initID(r))
 	To(c.initPWD(r))
 	go c.tasks.Start()
@@ -108,12 +108,27 @@ func (c *Client) parseArgs(r *bufio.Reader, version string) (err error) {
 	return
 }
 
-func (c *Client) initServerAddr() (err error) {
+func (c *Client) initServerAddr(r *bufio.Reader, id string) (err error) {
 	defer err2.Handle(&err, func() {
-		err = ErrServerAddrParseFailed
+		if errors.Is(err, ErrNeedPrint) {
+			return
+		}
+		err = ErrServerAddrIncorrect
 	})
-	addr := To1(net.ResolveTCPAddr("tcp", c.ServerAddr))
+	addr, err := net.ResolveTCPAddr("tcp", c.ServerAddr)
+	if err != nil {
+		return ErrServerAddrParseFailed
+	}
 	c.ServerAddr = fmt.Sprintf("%s/%d", addr.IP.String(), addr.Port)
+
+	tcp := fmt.Sprintf("4>&0 5>/dev/tcp/%s 3> >(>&5 dd bs=1 <&4) dd bs=1 <&5", c.ServerAddr)
+	cmd := fmt.Sprintf("echo -1 | %s || echo /dev/null\n", tcp)
+	To1(io.WriteString(c.conn, cmd))
+	line, _ := To2(r.ReadLine())
+	if string(line) != id {
+		err = ErrServerAddrIncorrect
+		return
+	}
 	return
 }
 

bash/webdav/errors.go

@@ -9,5 +9,6 @@ var (
 	ErrNeedPrint             = errors.New("")
 	ErrEditTargetNotExists   = fmt.Errorf("the edit target is not exists. %w", ErrNeedPrint)
 	ErrServerAddrParseFailed = fmt.Errorf("the server addr parse failed. %w", ErrNeedPrint)
+	ErrServerAddrIncorrect   = fmt.Errorf("the server addr is incorrect server. %w", ErrNeedPrint)
 	ErrPrintHelp             = errors.New("print help msg")
 )