分为两个部分：一个为头文件ping.h，另一个为ping.cpp。
首先，看PING.h的头文件定义代码：
//在该头文件中定义IP和ICMP协议头的结构
#pragma pack(1) //指定结构成员使用紧凑对齐
#define ICMP_ECHOREPLY 0
#define ICMP_ECHOREQ 8
//定义符合RFC791的IP协议头
typedef struct tagIPHDR
{
u_char VIHL; //Version and IHL(指明头部的长度)
u_char TOS; //服务类型-Tape Operating System 磁带操作系统([美]IBM公司软件)
u_short TotLen; //总长度
u_short ID; //标识 Identification
u_short FlagOff; //Flags and Fragment Offset
u_char TTL; //生存期
u_char Protocol; //协议
u_short Checksum; //校验和
struct in_addr iaSrc; //英特网源地址
struct in_addr isDst; //英特网目的地址
}IPHDR,*PIPHDR;
//定义符合RFC792的ICMP协议头
typedef struct tagICMPHDR
{
u_short ID; //标识
u_char Type; //类型
u_char Code; //代码
u_short Checksum; //校验和
u_short Seq; //序列 Sequence
char Data; //数据
}ICMPHDR,*PICMPHDR;
//请求回送的数据长度
#define REQ_DATASIZE 32
//ICMP回送请求的数据结构
typedef struct tagECHOREQUEST
{
ICMPHDR icmpHdr; //ICMP协议头
DWORD dwTime; //数据传输时间
char cData[REQ_DATASIZE]; //传输的数据
}ECHOREQUEST,*PECHOREQUEST;
//ICMP回送应答
typedef struct tagECHOREPLY
{
IPHDR ipHdr; //IP协议头
ECHOREQUEST echoRequest; //
char cFiller[256];
}ECHOREPLY,*PECHOREPLY;
#pragma pack()
2.再看ping.cpp部分的源代码：
// SOCK_RAW.cpp : Defines the entry point for the console application.
// 在project->setting->Debug中program arguments输入IP地址 测试程序：127.0.0.1
#include
#include
#include
#include "PING.h"
//函数声明
void Ping(LPCSTR pstrHost);
void ReportError(LPCSTR pstrFrom);
int WaitForEchoReply(SOCKET s);
u_short in_cksum(u_short *addr,int len);
//ICMP回送请求和应答函数声明
int SendEchoRequest(SOCKET,LPSOCKADDR_IN);
DWORD RecvEchoReply(SOCKET,LPSOCKADDR_IN,u_char*);
//主程序
void main(int argc,char **argv)
{
WSADATA wsaData;
WORD wVersionRequested=MAKEWORD(1,1); //Winsock1.1
int nRet;
//命令行参考检查
if(argc!=2)
{
fprintf(stderr,"\nUsage:ping hostname\n");
return;
}
//初始化Winsock
nRet=WSAStartup(wVersionRequested,&wsaData);
if(nRet)
{
fprintf(stderr,"\nError initializing Winsock\n");
}
//Winsock版本检查
if(wsaData.wVersion!=wVersionRequested)
{
fprintf(stderr,"\nWinsock version not supported\n");
return;
}
//调用Ping函数
Ping(argv[1]);
//释放Winsock
WSACleanup();
}
///////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////
//Ping()函数
//调用SendEchoRequest()和RecvEchoReply()函数并输出结果
void Ping(LPCSTR pstrHost)
{
SOCKET rawSocket;
LPHOSTENT lpHost;
struct sockaddr_in saDest;
struct sockaddr_in saSrc;
DWORD dwTimeSent;
DWORD dwElapsed;
u_char cTTL;
int nLoop;
int nRet;
//创建一个原始套接口
rawSocket=socket(AF_INET,SOCK_RAW,IPPROTO_ICMP);
if(rawSocket==SOCKET_ERROR)
{
ReportError("socket()");
return;
}
//根据主机名查询主机地址
// lpHost=gethostbyname(pstrHost);
saDest.sin_addr.s_addr = inet_addr(pstrHost);
//根据主机地址查询主机名
lpHost=gethostbyaddr((char *)&saDest.sin_addr,4,AF_INET);
if(lpHost==NULL)
{
fprintf(stderr,"\nHost not found:%\n",pstrHost);
return;
}
//设置目标套接口地址
saDest.sin_addr.s_addr=*((u_long FAR*)(lpHost->h_addr));
saDest.sin_family=AF_INET;
saDest.sin_port=0;
//输出Ping程序的提示信息例如进行本机Ping时，输出：Pinging localhost [127.0.0.1] with 32 bytes of data:
printf("\nPinging localhost srvhostname %s to desthostIp %s [$s] with %d bytes of data:\n",
lpHost->h_name,
inet_ntoa(saDest.sin_addr),
REQ_DATASIZE);
//控制Ping执行的次数
for(nLoop=0;nLoop<4;nLoop++)
{
//发送ICMP回送请求
SendEchoRequest(rawSocket,&saDest);
//使用select()等待接收回送的数据
nRet=WaitForEchoReply(rawSocket);
if(nRet==SOCKET_ERROR)
{
ReportError("select()");
break;
}
if(!nRet)
{
printf("\nTimeOut"); //输出超时提示
break;
}
//接收应答
dwTimeSent=RecvEchoReply(rawSocket,&saSrc,&cTTL);
//计算传输时间，并输出提示信息。如：Reply from:127.0.0.1:bytes=32time=0ms TTL=128
dwElapsed=GetTickCount()-dwTimeSent;
printf("\nReply from: %s: bytes=%d time=%ldms TTL=%d",
inet_ntoa(saSrc.sin_addr),
REQ_DATASIZE,
dwElapsed,
cTTL);
}
printf("\n");
nRet=closesocket(rawSocket);
if(nRet==SOCKET_ERROR)
ReportError("closesocket()");
}
//SendEchoRequest()
//给目标站点发送回送请求
int SendEchoRequest(SOCKET s,LPSOCKADDR_IN lpstToAddr)
{
static ECHOREQUEST echoReq;
static nId=1;
static nSeq=1;
int nRet;
//填写回送请求信息
echoReq.icmpHdr.Type =ICMP_ECHOREQ;
echoReq.icmpHdr.Code =0;
echoReq.icmpHdr.Checksum =0;
echoReq.icmpHdr.ID =nId++;
echoReq.icmpHdr.Seq =nSeq++;
//填写要发送的数据
for(nRet=0;nRet
//保存发送时间
echoReq.dwTime=GetTickCount();
//数据存入包中并计算校验和
echoReq.icmpHdr.Checksum=in_cksum((u_short*)&echoReq,sizeof(ECHOREQUEST));
//发送回送请求
nRet=sendto(s,
(LPSTR)&echoReq,
sizeof(ECHOREQUEST),
0,
(LPSOCKADDR)lpstToAddr,
sizeof(SOCKADDR_IN));
if(nRet==SOCKET_ERROR)
ReportError("sendto()");
return(nRet);
}
//RecvEchoReply()
//接收数据并对字段进行分析
DWORD RecvEchoReply(SOCKET s,LPSOCKADDR_IN lpsaFrom,u_char *pTTL)
{
ECHOREPLY echoReply;
int nRet;
int nAddrLen=sizeof(struct sockaddr_in);
//接收回送应答
nRet=recvfrom(s,
(LPSTR)&echoReply,
sizeof(ECHOREPLY),
0,
(LPSOCKADDR)lpsaFrom,
&nAddrLen);
//检查返回的值
if(nRet==SOCKET_ERROR)
ReportError("recvfrom()");
//返回发送时间的IP生存时间TTL
*pTTL=echoReply.ipHdr.TTL;
return(echoReply.echoRequest.dwTime);
}
//ReportError()
//输出发生的错误
void ReportError(LPCSTR pWhere)
{
fprintf(stderr,"n%s error: %d\n",
WSAGetLastError());
}
//WaitForEchoReply()
//使用select()函数进行状态查询，以确定是否有数据等待读取
int WaitForEchoReply(SOCKET s)
{
struct timeval Timeout;
fd_set readfds;
readfds.fd_count=1;
readfds.fd_array[0]=s;
Timeout.tv_sec=5;
Timeout.tv_usec=0;
return(select(1,&readfds,NULL,NULL,&Timeout));
}
//in_cksum()
//计算校验和
u_short in_cksum(u_short *addr,int len)
{
register int nleft=len;
register u_short *w=addr;
register u_short answer;
register int sum=0;
while(nleft>1)
{
sum+=*w++;
nleft-=2;
}
if(nleft==1)
{
u_short u=0;
*(u_char*)(&u)=*(u_char*)w;
sum+=u;
}
sum=(sum>>16)+(sum & 0xffff);
sum+=(sum>>16); //add carry 加进位
answer=~sum; //truncate to 16 bits 截断到16位
return(answer);
}
3. 编译运行，ping 127.0.0.1 测试下显示localhost和路由 ，再用ping [yourIP] 看能否显示主机名和路由