using System;
using System.Collections.Generic;using System.Linq;using System.Text;using System.Net.Sockets;namespace BLL
{ public class TelnetClient { private TcpClient Client; private NetworkStream ns; private string m_LogonPrompt = "ogin:"; private string m_PasswordPrompt = "assword:"; private readonly int BuffSize = 1024 * 4;/// <summary>
/// 登录输入用户名提示字符 /// 默认值：ogin: /// </summary> public string LoginPrompt { set { m_LogonPrompt = value; } get { return m_LogonPrompt; } } /// <summary> /// 登录输入密码提示字符 /// 默认值：assword: /// </summary> public string PasswordPrompt { set { m_PasswordPrompt = value; } get { return m_PasswordPrompt; } } /// <summary> /// 连接状态 /// </summary> public bool Connected { get { return Client != null ? Client.Connected : false; } } /// <summary> /// 连接远端主机 /// </summary> /// <param name="hostname">主机名称</param> /// <param name="port">端口</param> /// <returns>远端主机响应文本</returns> public string Connect(string hostname, int port) { string result = string.Empty; try { Client = new TcpClient(hostname, port); ns = Client.GetStream(); result = Negotiate(); } catch (Exception e) { result = e.Message; } return result; } /// <summary> /// 连接远端主机并登录 /// </summary> /// <param name="hostname">主机名称</param> /// <param name="port">端口</param> /// <param name="username">用户名</param> /// <param name="password">密码</param> /// <param name="waitTime">连接等待时间</param> /// <returns></returns> public string Connect(string hostname, int port, string username, string password, int waitTime) { string result = string.Empty; result = Connect(hostname, port); if (Connected && result.EndsWith(LoginPrompt)) { Send(username, waitTime); result = Receive(); if (result.EndsWith(PasswordPrompt)) { Send(password, waitTime); result = Receive(); if (!result.EndsWith("<")) { Client.Close(); result = "Logon Error"; } } } return result; } /// <summary> /// 接收 /// </summary> /// <returns>传回的数据</returns> public string Receive() { StringBuilder result = new StringBuilder(); if (Connected && ns.CanRead) { byte[] buff = new byte[BuffSize]; int numberOfRead = 0; do { numberOfRead = ns.Read(buff, 0, BuffSize); result.AppendFormat("{0}", Encoding.ASCII.GetString(buff, 0, numberOfRead)); } while (ns.DataAvailable); } return result.ToString().Trim(); } /// <summary> /// 发送 /// </summary> /// <param name="cmd">指令</param> /// <param name="waitTime">等待超时时间（毫秒）</param> public void Send(string cmd, int waitTime) { if (Connected && ns.CanWrite) { cmd += "\r\n"; byte[] buff = Encoding.ASCII.GetBytes(cmd); ns.Write(buff, 0, buff.Length); System.Threading.Thread.Sleep(waitTime); } } /// <summary> /// 关闭 /// </summary> public void Close() { Client.Close(); } /// <summary> /// 处理Telnet选项谈判，直到出现用户名输入提示 /// </summary> /// <returns></returns> private string Negotiate() { string result = string.Empty; if (Connected) { while (true) { byte[] rev = ReceiveBytes(); result = Encoding.ASCII.GetString(rev).Trim(); if (result.EndsWith(LoginPrompt)) { break; } int count = rev.Length / 3; for (int i = 0; i < count; i++) { int iac = rev[i * 3]; int cmd = rev[i * 3 + 1]; int value = rev[i * 3 + 2]; if (((int)Verbs.IAC) != iac) { continue; } switch (cmd) { case (int)Verbs.DO: ns.WriteByte((byte)iac); ns.WriteByte(value == (int)Options.RD ? (byte)Verbs.WILL : (byte)Verbs.WONT); ns.WriteByte((byte)value); break; case (int)Verbs.DONT: ns.WriteByte((byte)iac); ns.WriteByte((byte)Verbs.WONT); ns.WriteByte((byte)value); break; case (int)Verbs.WILL: ns.WriteByte((byte)iac); ns.WriteByte(value == (int)Options.SGA ? (byte)Verbs.DO : (byte)Verbs.DONT); ns.WriteByte((byte)value); break; case (int)Verbs.WONT: ns.WriteByte((byte)iac); ns.WriteByte((byte)Verbs.DONT); ns.WriteByte((byte)value); break; default: break; } } } } return result; } /// <summary> /// 读取字节流 /// </summary> /// <returns></returns> private byte[] ReceiveBytes() { byte[] result = new byte[0]; byte[] buff = new byte[BuffSize]; int numberOfRead = 0; if (Connected && ns.CanRead) { numberOfRead = ns.Read(buff, 0, BuffSize); result = new byte[numberOfRead]; Array.Copy(buff, result, numberOfRead); } return result; } } enum Verbs { WILL = 251, WONT = 252, DO = 253, DONT = 254, IAC = 255 } enum Options { RD = 1, SGA = 3 }}