C#中实现Ping

在C#中实现Ping，代码如下：

using System;
using System.Net;
using System.Net.Sockets;
///ping.cs
namespace  SystemMonitor {
///
///  主要的类:ping
///
class  Ping {
//声明几个常量
const  int  SOCKET_ERROR  =  -1;
const  int  ICMP_ECHO  =  8;
///
///  这里取得Hostname参数
///
public  static  void  PingUrl(string[]  argv) {
if(argv.Length==0) {
//If  user  did  not  enter  any  Parameter  inform  him
Console.WriteLine("Usage:Ping    /r")  ;
Console.WriteLine("  The  name  of  the  Host  who  you  want  to  ping");
Console.WriteLine("/r  Ping  the  host  continuously")  ;
}
else  if(argv.Length==1) {
//Just  the  hostname  provided  by  the  user
//call  the  method  "PingHost"  and  pass  the  HostName  as  a  parameter
PingHost(argv[0])  ;
}
else  if(argv.Length==2) {
//the  user  provided  the  hostname  and  the  switch
if(argv[1]=="/r") {
//loop  the  ping  program
while(true) {
//call  the  method  "PingHost"  and  pass  the  HostName  as  a  parameter
PingHost(argv[0])  ;
}
}
else {
//if  the  user  provided  some  other  switch
PingHost(argv[0])  ;
}
}
else {
//Some  error  occurred
Console.WriteLine("Error  in  Arguments")  ;
}
}
///
///  主要的方法，用来取得IP，
///  并计算响应时间
///
public  static  void  PingHost(string  host) {
//Declare  the  IPHostEntry
IPHostEntry  serverHE,  fromHE;
int  nBytes  =  0;
int  dwStart  =  0,  dwStop  =  0;
//Initilize  a  Socket  of  the  Type  ICMP
Socket  socket  =
new  Socket(AddressFamily.InterNetwork,  SocketType.Raw,  ProtocolType.Icmp);
//  Get  the  server  endpoint
try {
serverHE  =  Dns.GetHostByName(host);
}
catch(Exception) {
Console.WriteLine("Host  not  found");  //  fail
return  ;
}
//  Convert  the  server  IP_EndPoint  to  an  EndPoint
IPEndPoint  ipepServer  =  new  IPEndPoint(serverHE.AddressList[0],  0);
EndPoint  epServer  =  (ipepServer);
//  Set  the  receiving  endpoint  to  the  client  machine
fromHE  =  Dns.GetHostByName(Dns.GetHostName());
IPEndPoint  ipEndPointFrom  =  new  IPEndPoint(fromHE.AddressList[0],  0);
EndPoint  EndPointFrom  =  (ipEndPointFrom);
int  PacketSize  =  0;
IcmpPacket  packet  =  new  IcmpPacket();
//  Construct  the  packet  to  send
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];
//Initilize  the  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  ) {
Console.WriteLine("Error  in  Making  Packet");
return  ;
}
//  now  get  this  critter  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  ) {
Console.WriteLine("Error  in  Making  Packet");
return  ;
}
dwStart  =  System.Environment.TickCount;  //  Start  timing
//send  the  Pack  over  the  socket
if  ((nBytes  =  socket.SendTo(sendbuf,  PacketSize,  0,  epServer))  ==  SOCKET_ERROR) {
Console.WriteLine("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) {
Console.WriteLine("Host  not  Responding")  ;
recd=true  ;
break;
}
else  if(nBytes>0) {
dwStop  =  System.Environment.TickCount  -  dwStart;  //  stop  timing
Console.WriteLine("Reply  from  "+epServer.ToString()+"  in  "
+dwStop+"MS  :Bytes  Received"+nBytes);
recd=true;
break;
}
timeout=System.Environment.TickCount  -  dwStart;
if(timeout>1000) {
Console.WriteLine("Time  Out")  ;
recd=true;
}
}
//close  the  socket
socket.Close();
}
///
///  This  method  get  the  Packet  and  calculates  the  total  size
///  of  the  Pack  by  converting  it  to  byte  array
///
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);
//  Console.WriteLine("Serialize  type  ");
Array.Copy(  b_type,  0,  Buffer,  Index,  b_type.Length  );
Index  +=  b_type.Length;
//  Console.WriteLine("Serialize  code  ");
Array.Copy(  b_code,  0,  Buffer,  Index,  b_code.Length  );
Index  +=  b_code.Length;
//  Console.WriteLine("Serialize  cksum  ");
Array.Copy(  b_cksum,  0,  Buffer,  Index,  b_cksum.Length  );
Index  +=  b_cksum.Length;
//  Console.WriteLine("Serialize  id  ");
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;
}
///
///  This  Method  has  the  algorithm  to  make  a  checksum
///
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);
}
}  //  class  ping
///
///  Class  that  holds  the  Pack  information
///
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
}