309 lines
6.6 KiB
Go
309 lines
6.6 KiB
Go
package telnetOMC
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import (
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"bufio"
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"fmt"
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"strings"
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"sync"
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"time"
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"be.ems/lib/dborm"
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"github.com/reiver/go-telnet"
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)
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type TelnetHandler struct {
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ListenAddr string
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ListenPort uint16
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UserName string
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Password string
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AuthType string
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MaxConnNum uint8
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TagNE string
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ListenHost string
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connCount int
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mu sync.Mutex
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}
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func (t *TelnetHandler) HandleTelnetConnection(w telnet.Writer, r telnet.Reader) {
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t.mu.Lock()
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if t.connCount >= int(t.MaxConnNum) {
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t.mu.Unlock()
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w.Write([]byte("Connection limit reached. Try again later.\r\n"))
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return
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}
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t.connCount++
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t.mu.Unlock()
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defer func() {
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t.mu.Lock()
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t.connCount--
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t.mu.Unlock()
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}()
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reader := bufio.NewReader(r)
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writer := bufio.NewWriter(w)
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// 发送欢迎信息
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writer.WriteString("Welcome to the Telnet server!\r\n")
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writer.Flush()
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// 请求用户名
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writer.WriteString("Username: ")
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writer.Flush()
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user, _ := reader.ReadString('\n')
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user = strings.TrimSpace(user)
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// 关闭回显模式
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writer.Write([]byte{255, 251, 1}) // IAC WILL ECHO
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writer.Flush()
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// 请求密码
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writer.WriteString("Password: ")
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writer.Flush()
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// 读取密码并清除控制序列
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var passBuilder strings.Builder
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for {
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b, err := reader.ReadByte()
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if err != nil {
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return
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}
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if b == '\n' || b == '\r' {
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break
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}
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if b == 255 { // IAC
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reader.ReadByte() // 忽略下一个字节
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reader.ReadByte() // 忽略下一个字节
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} else {
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passBuilder.WriteByte(b)
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}
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}
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pass := passBuilder.String()
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// 恢复回显模式
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writer.Write([]byte{255, 252, 1}) // IAC WONT ECHO
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writer.Flush()
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if t.HandleAuth(t.AuthType, user, pass) {
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writer.WriteString("\r\nAuthentication successful!\r\n")
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writer.Flush()
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t.HandleCommands(user, t.TagNE, reader, writer)
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} else {
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writer.WriteString("\r\nAuthentication failed!\r\n")
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writer.Flush()
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}
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}
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// 处理命令输入
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func (t *TelnetHandler) HandleCommands(user, tag string, reader *bufio.Reader, writer *bufio.Writer) {
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header := fmt.Sprintf("[%s@%s]> ", user, tag)
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clearLine := "\033[2K\r" // ANSI 转义序列，用于清除当前行
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for {
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writer.WriteString(clearLine + header)
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writer.Flush()
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var commandBuilder strings.Builder
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for {
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b, err := reader.ReadByte()
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if err != nil {
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return
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}
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if b == '\n' || b == '\r' {
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break
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}
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if b == 127 { // 处理退格键
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if commandBuilder.Len() > 0 {
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// 手动截断字符串
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command := commandBuilder.String()
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command = command[:len(command)-1]
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commandBuilder.Reset()
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commandBuilder.WriteString(command)
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writer.WriteString("\b \b") // 回显退格
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writer.Flush()
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}
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} else {
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// 回显用户输入的字符
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writer.WriteByte(b)
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writer.Flush()
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commandBuilder.WriteByte(b)
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}
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}
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command := strings.TrimSpace(commandBuilder.String())
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// command, err := reader.ReadString('\n')
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// if err != nil {
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// return
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// }
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// command = strings.TrimSpace(command)
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// 处理其他命令
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switch command {
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case "hello":
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writer.WriteString("\r\nHello, world!\r\n")
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case "time":
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writer.WriteString(fmt.Sprintf("\r\nCurrent time: %s\r\n", time.Now().Format(time.RFC1123)))
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case "exit", "quit":
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writer.WriteString("\r\nGoodbye!\r\n")
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writer.Flush()
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return
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case "":
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// case "\n":
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// case "\r\n":
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case "\xff\xfe\x01":
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default:
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writer.WriteString("\r\nUnknown command\r\n")
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}
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writer.Flush()
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}
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}
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func (t *TelnetHandler) ServeTELNET(ctx telnet.Context, w telnet.Writer, r telnet.Reader) {
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t.mu.Lock()
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if t.connCount >= int(t.MaxConnNum) {
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t.mu.Unlock()
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w.Write([]byte("Connection limit reached. Try again later.\r\n"))
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return
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}
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t.connCount++
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t.mu.Unlock()
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defer func() {
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t.mu.Lock()
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t.connCount--
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t.mu.Unlock()
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}()
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writer := bufio.NewWriter(w)
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reader := bufio.NewReader(r)
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// 发送欢迎信息
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writer.WriteString("Welcome to the Telnet server!\r\n")
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writer.Flush()
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// 请求用户名
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writer.WriteString("Username: ")
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writer.Flush()
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user, _ := reader.ReadString('\n')
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user = strings.TrimSpace(user)
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// 关闭回显模式
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writer.Write([]byte{255, 251, 1}) // IAC WILL ECHO
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writer.Flush()
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// 请求密码
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writer.WriteString("Password: ")
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writer.Flush()
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// 读取密码并清除控制序列
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var passBuilder strings.Builder
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for {
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b, err := reader.ReadByte()
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if err != nil {
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return
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}
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if b == '\n' || b == '\r' {
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break
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}
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if b == 255 { // IAC
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reader.ReadByte() // 忽略下一个字节
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reader.ReadByte() // 忽略下一个字节
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} else {
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passBuilder.WriteByte(b)
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}
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}
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pass := passBuilder.String()
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// 恢复回显模式
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writer.Write([]byte{255, 252, 1}) // IAC WONT ECHO
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writer.Flush()
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// w.Write([]byte("Welcome to the Telnet server!\r\n"))
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// w.Write([]byte("Username: "))
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// writer := bufio.NewWriter(w)
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// reader := bufio.NewReader(r)
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// writer.Flush()
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// user, _ := reader.ReadString('\n')
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// user = strings.TrimSpace(user)
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// w.Write([]byte("Password: "))
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// writer.Flush()
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// pass, _ := reader.ReadString('\n')
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// pass = strings.TrimSpace(pass)
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if !t.HandleAuth(t.AuthType, user, pass) {
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w.Write([]byte("\r\nAuthentication failed!\r\n"))
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writer.Flush()
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return
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}
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w.Write([]byte("\r\nAuthentication successful!\r\n"))
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writer.Flush()
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header := fmt.Sprintf("[%s@%s]> ", t.UserName, t.TagNE)
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for {
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w.Write([]byte(header))
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var command strings.Builder
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for {
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b := make([]byte, 1)
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_, err := r.Read(b)
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if err != nil {
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return
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}
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if b[0] == '\r' || b[0] == '\n' {
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break
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}
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command.WriteByte(b[0])
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}
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cmd := strings.TrimSpace(command.String())
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switch cmd {
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case "hello":
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w.Write([]byte("Hello, world!\r\n"))
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case "time":
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w.Write([]byte(fmt.Sprintf("Current time: %s\r\n", time.Now().Format(time.RFC1123))))
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case "exit", "quit":
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w.Write([]byte("Goodbye!\r\n"))
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return
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default:
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w.Write([]byte("Unknown command\r\n"))
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}
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}
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}
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func (t *TelnetHandler) HandleAuth(authType, userName, password string) bool {
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switch authType {
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case "local":
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if userName == t.UserName && password == t.Password {
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return true
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}
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return false
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case "radius":
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exist, err := dborm.XEngDB().Table("OMC_PUB.sysUser").Where("userName=? AND password=md5(?)", userName, password).Exist()
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if err != nil {
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return false
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}
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return exist
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case "omc":
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default:
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}
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return false
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}
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func (t *TelnetHandler) StartTelnetServer() {
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// //handle := TelnetHandler{}
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// listener, err := net.Listen("tcp", t.ListenHost)
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// if err != nil {
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// fmt.Println("Error starting Telnet server:", err)
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// return
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// }
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// defer listener.Close()
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// fmt.Printf("Telnet server started on %s\n", t.ListenHost)
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// go telnet.Serve(listener, t)
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go telnet.ListenAndServe(t.ListenHost, t)
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}
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