一种比较简单的实现ping的方式
<span style="font-family: Arial, Helvetica, sans-serif;">头文件</span>
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<span style="font-family: Arial, Helvetica, sans-serif;">#ifndef __PING_H__</span>
#define __PING_H__
//
// Ping.h
//
#pragma once
#pragma pack(1)
#include <winsock2.h>
#define ICMP_ECHOREPLY 0
#define ICMP_ECHOREQ 8
#define PINGERR_SOCKET_ERROR -1
#define PINGERR_TIMEOUT -2
#define PINGERR_NOHOST -3
class CPing
{
public:
int Ping(int ip);
protected:
int WaitForEchoReply(SOCKET s);
// ICMP Echo Request/Reply functions
int SendEchoRequest(SOCKET, LPSOCKADDR_IN);
DWORD RecvEchoReply(SOCKET, LPSOCKADDR_IN, u_char *);
u_short in_cksum(u_short *addr, int len);
};
// IP Header -- RFC 791
typedef struct tagIPHDR
{
u_char VIHL; // Version and IHL
u_char TOS; // Type Of Service
short TotLen; // Total Length
short ID; // Identification
short FlagOff; // Flags and Fragment Offset
u_char TTL; // Time To Live
u_char Protocol; // Protocol
u_short Checksum; // Checksum
struct in_addr iaSrc; // Internet Address - Source
struct in_addr iaDst; // Internet Address - Destination
}IPHDR, *PIPHDR;
// ICMP Header - RFC 792
typedef struct tagICMPHDR
{
u_char Type; // Type
u_char Code; // Code
u_short Checksum; // Checksum
u_short ID; // Identification
u_short Seq; // Sequence
char Data; // Data
}ICMPHDR, *PICMPHDR;
#define REQ_DATASIZE 32 // Echo Request Data size
// ICMP Echo Request
typedef struct tagECHOREQUEST
{
ICMPHDR icmpHdr;
DWORD dwTime;
char cData[REQ_DATASIZE];
}ECHOREQUEST, *PECHOREQUEST;
// ICMP Echo Reply
typedef struct tagECHOREPLY
{
IPHDR ipHdr;
ECHOREQUEST echoRequest;
char cFiller[256];
}ECHOREPLY, *PECHOREPLY;
#pragma pack()
#endif
实现
//
// THIS CODE IS BASED ON THE CODE FROM
// THE BOOK WINSOCK 2.0 BY LEWIS NAPPER...
//
//
#include "ping.h"
#include <Mmsystem.h>
#pragma comment( lib,"winmm.lib" )
#pragma comment(lib,"ws2_32.lib")
int CPing::Ping(int ip)
{
SOCKET rawSocket;
int nRet;
struct sockaddr_in saDest;
struct sockaddr_in saSrc;
DWORD dwTimeSent;
DWORD dwElapsed;
u_char cTTL;
// Create a Raw socket
rawSocket = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
if (rawSocket == SOCKET_ERROR)
{
return PINGERR_SOCKET_ERROR;
}
// Setup destination socket address
saDest.sin_addr.s_addr = ip;
saDest.sin_family = AF_INET;
saDest.sin_port = 0;
// Send ICMP echo request
SendEchoRequest(rawSocket, &saDest);
nRet = WaitForEchoReply(rawSocket);
if (nRet == SOCKET_ERROR)
{
return PINGERR_SOCKET_ERROR;
}
if (!nRet)
{
return PINGERR_TIMEOUT;
}
else
{
// Receive reply
dwTimeSent = RecvEchoReply(rawSocket, &saSrc, &cTTL);
// Calculate elapsed time
dwElapsed = timeGetTime() - dwTimeSent;
}
nRet = closesocket(rawSocket);
return (int)dwElapsed;
}
int CPing::SendEchoRequest(SOCKET s,LPSOCKADDR_IN lpstToAddr)
{
static ECHOREQUEST echoReq;
static int nId = 1;
static int nSeq = 1;
int nRet;
// Fill in echo request
echoReq.icmpHdr.Type = ICMP_ECHOREQ;
echoReq.icmpHdr.Code = 0;
echoReq.icmpHdr.Checksum = 0;
echoReq.icmpHdr.ID = u_short(nId++);
echoReq.icmpHdr.Seq = u_short(nSeq++);
// Fill in some data to send
for (nRet = 0; nRet < REQ_DATASIZE; nRet++)
echoReq.cData[nRet] = char(' '+nRet);
// Save tick count when sent
echoReq.dwTime = timeGetTime();
// Put data in packet and compute checksum
echoReq.icmpHdr.Checksum = in_cksum((u_short *)&echoReq, sizeof(ECHOREQUEST));
// Send the echo request
nRet = sendto(s, /* socket */
(LPSTR)&echoReq, /* buffer */
sizeof(ECHOREQUEST),
0, /* flags */
(LPSOCKADDR)lpstToAddr, /* destination */
sizeof(SOCKADDR_IN)); /* address length */
return (nRet);
}
DWORD CPing::RecvEchoReply(SOCKET s, LPSOCKADDR_IN lpsaFrom, u_char *pTTL)
{
ECHOREPLY echoReply;
int nRet;
int nAddrLen = sizeof(struct sockaddr_in);
// Receive the echo reply
nRet = recvfrom(s, // socket
(LPSTR)&echoReply, // buffer
sizeof(ECHOREPLY), // size of buffer
0, // flags
(LPSOCKADDR)lpsaFrom, // From address
&nAddrLen); // pointer to address len
// return time sent and IP TTL
*pTTL = echoReply.ipHdr.TTL;
return(echoReply.echoRequest.dwTime);
}
int CPing::WaitForEchoReply(SOCKET s)
{
struct timeval Timeout;
fd_set readfds;
readfds.fd_count = 1;
readfds.fd_array[0] = s;
Timeout.tv_sec = 1;
Timeout.tv_usec = 0;
return(select(1, &readfds, NULL, NULL, &Timeout));
}
//
// Mike Muuss' in_cksum() function
// and his comments from the original
// ping program
//
// * Author -
// * Mike Muuss
// * U. S. Army Ballistic Research Laboratory
// * December, 1983
/*
* I N _ C K S U M
*
* Checksum routine for Internet Protocol family headers (C Version)
*
*/
u_short CPing::in_cksum(u_short *addr, int len)
{
register int nleft = len;
register u_short *w = addr;
register u_short answer;
register int sum = 0;
/*
* Our algorithm is simple, using a 32 bit accumulator (sum),
* we add sequential 16 bit words to it, and at the end, fold
* back all the carry bits from the top 16 bits into the lower
* 16 bits.
*/
while( nleft > 1 ) {
sum += *w++;
nleft -= 2;
}
/* mop up an odd byte, if necessary */
if( nleft == 1 ) {
u_short u = 0;
*(u_char *)(&u) = *(u_char *)w ;
sum += u;
}
/*
* add back carry outs from top 16 bits to low 16 bits
*/
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
answer = u_short(~sum); /* truncate to 16 bits */
return (answer);
}