fix: telnet serve enhancement

sshsvc/sshsvc.go

@@ -19,6 +19,7 @@ import (
 	"be.ems/sshsvc/config"
 	"be.ems/sshsvc/logmml"
 	"be.ems/sshsvc/snmp"
+	telnetOMC "be.ems/sshsvc/telnet"
 
 	//"github.com/gliderlabs/ssh"
 	"golang.org/x/crypto/ssh"
@@ -110,22 +111,34 @@ func main() {
 		log.Fatal("Failed to Listen: ", err)
 		os.Exit(4)
 	}
-	fmt.Printf("MML SSH server startup, listen port：%d\n", conf.Sshd.ListenPort)
+	//fmt.Printf("MML SSH server startup, listen port：%d\n", conf.Sshd.ListenPort)
 	// 启动telnet服务器
-	telnetUri := fmt.Sprintf("%s:%d", conf.TelnetServer.ListenAddr, conf.TelnetServer.ListenPort)
+	//telnetUri := fmt.Sprintf("%s:%d", conf.TelnetServer.ListenAddr, conf.TelnetServer.ListenPort)
 	// telnetListener, err := net.Listen("tcp", telnetUri)
 	// if err != nil {
 	// 	log.Fatal("Failed to Listen: ", err)
 	// 	os.Exit(4)
 	// }
-	fmt.Printf("MML Telnet server startup, listen port：%d\n", conf.TelnetServer.ListenPort)
+	//fmt.Printf("MML Telnet server startup, listen port：%d\n", conf.TelnetServer.ListenPort)
 	// telnetconn, err := telnetListener.Accept()
 	// if err != nil {
 	// 	log.Fatal("Failed to accept telnet connection: ", err)
 	// 	os.Exit(6)
 	// }
 
-	go startTelnetServer(telnetUri)
+	telnetSvc := telnetOMC.TelnetHandler{
+		// ListenAddr: conf.TelnetServer.ListenAddr,
+		// ListenPort: conf.TelnetServer.ListenPort,
+		// UserName:   conf.TelnetServer.UserName,
+		// Password:   conf.TelnetServer.Password,
+		// AuthType:   conf.TelnetServer.AuthType,
+		// MaxConnNum: conf.TelnetServer.MaxConnNum,
+		// TagNE:      conf.TelnetServer.TagNE,
+		ListenHost: conf.TelnetServer.ListenAddr + ":" + strconv.Itoa(int(conf.TelnetServer.ListenPort)),
+	}
+	// go telnetSvc.StartTelnetServer()
+	go StartTelnetServer(telnetSvc.ListenHost)
+
 	snmpSvc := snmp.SNMPService{
 		ListenAddr: conf.SNMPServer.ListenAddr,
 		ListenPort: conf.SNMPServer.ListenPort,
@@ -183,7 +196,7 @@ func handleAuth(authType, userName, password string) bool {
 	return false
 }
 
-func startTelnetServer(addr string) {
+func StartTelnetServer(addr string) {
 	listener, err := net.Listen("tcp", addr)
 	if err != nil {
 		fmt.Println("Error starting Telnet server:", err)
@@ -202,7 +215,7 @@ func startTelnetServer(addr string) {
 		telnetMu.Lock()
 		if telnetCC >= int(conf.TelnetServer.MaxConnNum) {
 			telnetMu.Unlock()
-			io.WriteString(conn, "Connection limit reached. Try again later.\n")
+			io.WriteString(conn, "Connection limit reached. Try again later.\r\n")
 			conn.Close()
 			continue
 		}
@@ -225,7 +238,7 @@ func handleTelnetConnection(conn net.Conn) {
 	writer := bufio.NewWriter(conn)
 
 	// 发送欢迎信息
-	writer.WriteString("Welcome to the Telnet server!\n")
+	writer.WriteString("Welcome to the Telnet server!\r\n")
 	writer.Flush()
 
 	// 请求用户名
@@ -266,41 +279,102 @@ func handleTelnetConnection(conn net.Conn) {
 	writer.Flush()
 
 	if handleAuth(conf.TelnetServer.AuthType, user, pass) {
-		writer.WriteString("\nAuthentication successful!\n")
+		writer.WriteString("\r\nAuthentication successful!\r\n")
 		writer.Flush()
-		handleCommands(user, conf.TelnetServer.TagNE, reader, writer)
+		HandleCommands(user, conf.TelnetServer.TagNE, reader, writer)
 	} else {
-		writer.WriteString("\nAuthentication failed!\n")
+		writer.WriteString("\r\nAuthentication failed!\r\n")
+		writer.Flush()
+	}
+}
+
+// 处理命令输
+func HandleCommands(user, tag string, reader *bufio.Reader, writer *bufio.Writer) {
+	header := fmt.Sprintf("[%s@%s]> ", user, tag)
+	clearLine := "\033[2K\r" // ANSI 转义序列，用于清除当前行
+	for {
+		var commandBuilder strings.Builder
+		for {
+			b, err := reader.ReadByte()
+			if err != nil {
+				return
+			}
+			if b == '\n' || b == '\r' {
+				break
+			}
+			if b == '\xff' || b == '\xfe' || b == '\x01' {
+				continue
+			}
+			if b == 127 { // 处理退格键
+				if commandBuilder.Len() > 0 {
+					// 手动截断字符串
+					command := commandBuilder.String()
+					command = command[:len(command)-1]
+					commandBuilder.Reset()
+					commandBuilder.WriteString(command)
+					writer.WriteString("\b \b") // 回显退格
+					writer.Flush()
+				}
+			} else {
+				// 回显用户输入的字符
+				writer.WriteByte(b)
+				writer.Flush()
+				commandBuilder.WriteByte(b)
+			}
+		}
+		command := strings.TrimSpace(commandBuilder.String())
+
+		// 处理其他命令
+		switch command {
+		case "hello":
+			writer.WriteString("\r\nHello, world!\r\n")
+		case "time":
+			writer.WriteString(fmt.Sprintf("\r\nCurrent time: %s\r\n", time.Now().Format(time.RFC1123)))
+		case "exit", "quit":
+			writer.WriteString("\r\nGoodbye!\r\n")
+			writer.Flush()
+			return
+		case "":
+		// case "\n":
+		// case "\r\n":
+		case "\xff\xfe\x01":
+		default:
+			writer.WriteString("\r\nUnknown command\r\n")
+			writer.Flush()
+		}
+		writer.WriteString(clearLine + header)
 		writer.Flush()
 	}
 }
 
 // 处理命令输入
-func handleCommands(user, tag string, reader *bufio.Reader, writer *bufio.Writer) {
+func HandleCommandsNew(user, tag string, reader *bufio.Reader, writer *bufio.Writer) {
 	header := fmt.Sprintf("[%s@%s]> ", user, tag)
+	clearLine := "\033[2K\r" // ANSI 转义序列，用于清除当前行
 	for {
+		writer.WriteString(clearLine + header)
+		writer.Flush()
+
 		command, err := reader.ReadString('\n')
 		if err != nil {
 			return
 		}
 		command = strings.TrimSpace(command)
-		// 处理其他命令
+
+		// Handle other commands
 		switch command {
 		case "hello":
-			writer.WriteString("Hello, world!\n")
+			writer.WriteString("\r\nHello, world!\r\n")
 		case "time":
-			writer.WriteString(fmt.Sprintf("Current time: %s\n", time.Now().Format(time.RFC1123)))
+			writer.WriteString(fmt.Sprintf("\r\nCurrent time: %s\r\n", time.Now().Format(time.RFC1123)))
 		case "exit", "quit":
-			writer.WriteString("Goodbye!\n")
+			writer.WriteString("\r\nGoodbye!\r\n")
 			writer.Flush()
 			return
-		case "":
-		case "\n":
-		case "\xff\xfe\x01":
 		default:
-			writer.WriteString("Unknown command\n")
+			writer.WriteString("\r\nUnknown command\r\n")
 		}
-		writer.WriteString(header)
+
 		writer.Flush()
 	}
 }