在C#中实现Ping
作者： 孟宪会 出自： 【孟宪会之精彩世界】 发布日期： 2003-7-10 17:03:52
在C#中实现Ping，代码如下：
using System;
using System.Drawing;
using System.Collections;
using System.Data;
using System.Net;
using System.Net.Sockets;
/// Ping类
public class Ping
{
//声明常量
const int SOCKET_ERROR = -1;
const int ICMP_ECHO = 8;
// 程序入口
public static void Main()
{
Ping p = new Ping();
Console.WriteLine("请输入要 Ping 的IP或者主机名字：");
string MyUrl = Console.ReadLine();
Console.WriteLine("正在 Ping " + MyUrl + " ……");
Console.Write(p.PingHost(MyUrl));
}
public string PingHost(string host)
{
// 声明 IPHostEntry
IPHostEntry serverHE, fromHE;
int nBytes = 0;
int dwStart = 0, dwStop = 0;
//初始化ICMP的Socket
Socket socket =
new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp);
socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.SendTimeout, 1000);
// 得到Server EndPoint
try
{
serverHE = Dns.GetHostByName(host);
}
catch (Exception)
{
return "没有发现主机";
}
// 把 Server IP_EndPoint转换成EndPoint
IPEndPoint ipepServer = new IPEndPoint(serverHE.AddressList[0], 0);
EndPoint epServer = (ipepServer);
// 设定客户机的接收Endpoint
fromHE = Dns.GetHostByName(Dns.GetHostName());
IPEndPoint ipEndPointFrom = new IPEndPoint(fromHE.AddressList[0], 0);
EndPoint EndPointFrom = (ipEndPointFrom);
int PacketSize = 0;
IcmpPacket packet = new IcmpPacket();
// 构建要发送的包
packet.Type = ICMP_ECHO; //8
packet.SubCode = 0;
packet.CheckSum = UInt16.Parse("0");
packet.Identifier = UInt16.Parse("45");
packet.SequenceNumber = UInt16.Parse("0");
int PingData = 32; // sizeof(IcmpPacket) - 8;
packet.Data = new Byte[PingData];
// 初始化Packet.Data
for (int i = 0; i < PingData; i++)
{
packet.Data[i] = (byte)'#';
}
//Variable to hold the total Packet size
PacketSize = PingData + 8;
Byte[] icmp_pkt_buffer = new Byte[PacketSize];
Int32 Index = 0;
//Call a Method Serialize which counts
//The total number of Bytes in the Packet
Index = Serialize(
packet,
icmp_pkt_buffer,
PacketSize,
PingData);
//Error in Packet Size
if (Index == -1)
{
return "Error Creating Packet";
}
// convert into a UInt16 array
//Get the Half size of the Packet
Double double_length = Convert.ToDouble(Index);
Double dtemp = Math.Ceiling(double_length / 2);
int cksum_buffer_length = Convert.ToInt32(dtemp);
//Create a Byte Array
UInt16[] cksum_buffer = new UInt16[cksum_buffer_length];
//Code to initialize the Uint16 array
int icmp_header_buffer_index = 0;
for (int i = 0; i < cksum_buffer_length; i++)
{
cksum_buffer[i] =
BitConverter.ToUInt16(icmp_pkt_buffer, icmp_header_buffer_index);
icmp_header_buffer_index += 2;
}
//Call a method which will return a checksum
UInt16 u_cksum = checksum(cksum_buffer, cksum_buffer_length);
//Save the checksum to the Packet
packet.CheckSum = u_cksum;
// Now that we have the checksum, serialize the packet again
Byte[] sendbuf = new Byte[PacketSize];
//again check the packet size
Index = Serialize(
packet,
sendbuf,
PacketSize,
PingData);
//if there is a error report it
if (Index == -1)
{
return "Error Creating Packet";
}
dwStart = System.Environment.TickCount; // Start timing
//send the Packet over the socket
if ((nBytes = socket.SendTo(sendbuf, PacketSize, 0, epServer)) == SOCKET_ERROR)
{
return "Socket Error: cannot send Packet";
}
// Initialize the buffers. The receive buffer is the size of the
// ICMP header plus the IP header (20 bytes)
Byte[] ReceiveBuffer = new Byte[256];
nBytes = 0;
//Receive the bytes
bool recd = false;
int timeout = 0;
//loop for checking the time of the server responding
while (!recd)
{
nBytes = socket.ReceiveFrom(ReceiveBuffer, 256, 0, ref EndPointFrom);
if (nBytes == SOCKET_ERROR)
{
return "主机没有响应";
}
else if (nBytes > 0)
{
dwStop = System.Environment.TickCount - dwStart; // stop timing
return "Reply from " + epServer.ToString() + " in "
+ dwStop + "ms. Received: " + nBytes + " Bytes.";
}
timeout = System.Environment.TickCount - dwStart;
if (timeout > 1000)
{
return "超时";
}
}
//close the socket
socket.Close();
return "";
}
/// <summary>
/// This method get the Packet and calculates the total size
/// of the Pack by converting it to byte array
/// </summary>
public static Int32 Serialize(IcmpPacket packet, Byte[] Buffer,
Int32 PacketSize, Int32 PingData)
{
Int32 cbReturn = 0;
// serialize the struct into the array
int Index = 0;
Byte[] b_type = new Byte[1];
b_type[0] = (packet.Type);
Byte[] b_code = new Byte[1];
b_code[0] = (packet.SubCode);
Byte[] b_cksum = BitConverter.GetBytes(packet.CheckSum);
Byte[] b_id = BitConverter.GetBytes(packet.Identifier);
Byte[] b_seq = BitConverter.GetBytes(packet.SequenceNumber);
Array.Copy(b_type, 0, Buffer, Index, b_type.Length);
Index += b_type.Length;
Array.Copy(b_code, 0, Buffer, Index, b_code.Length);
Index += b_code.Length;
Array.Copy(b_cksum, 0, Buffer, Index, b_cksum.Length);
Index += b_cksum.Length;
Array.Copy(b_id, 0, Buffer, Index, b_id.Length);
Index += b_id.Length;
Array.Copy(b_seq, 0, Buffer, Index, b_seq.Length);
Index += b_seq.Length;
// copy the data
Array.Copy(packet.Data, 0, Buffer, Index, PingData);
Index += PingData;
if (Index != PacketSize/* sizeof(IcmpPacket) */)
{
cbReturn = -1;
return cbReturn;
}
cbReturn = Index;
return cbReturn;
}
/// <summary>
/// This Method has the algorithm to make a checksum
/// </summary>
public static UInt16 checksum(UInt16[] buffer, int size)
{
Int32 cksum = 0;
int counter;
counter = 0;
while (size > 0)
{
UInt16 val = buffer[counter];
cksum += Convert.ToInt32(buffer[counter]);
counter += 1;
size -= 1;
}
cksum = (cksum >> 16) + (cksum & 0xffff);
cksum += (cksum >> 16);
return (UInt16)(~cksum);
}
}
/// 类结束
/// <summary>
///Class that holds the Pack information
/// </summary>
public class IcmpPacket
{
public Byte Type; // type of message
public Byte SubCode; // type of sub code
public UInt16 CheckSum; // ones complement checksum of struct
public UInt16 Identifier; // identifier
public UInt16 SequenceNumber; // sequence number
public Byte[] Data;
} // class IcmpPacket