ping 程序（vc6.0 原始套接字实现）

#include <stdio.h>
#include <WINSOCK2.H>
#include <windows.h>

#include <ws2tcpip.h> //IP_TTL
#pragma comment(lib,"ws2_32.lib")
//ICMP首部结构体
typedef struct tagICMPHEADER
{
unsigned char type;//类型
unsigned char code;//代码
unsigned short checknum;//检验和
unsigned short id;//标识符
unsigned short seq_num;//序列号
}ICMPHEADER;
//IP首部结构体
typedef struct _ip_hdr
{
unsigned char ihl:4;   //首部长度
unsigned char version:4, //版本
unsigned char tos;   //服务类型
unsigned short tot_len; //总长度
unsigned short id;    //标志
unsigned short frag_off; //分片偏移
unsigned char ttl;   //生存时间
unsigned char protocol; //协议
unsigned short chk_sum; //检验和
struct in_addr srcaddr; //源IP地址
struct in_addr dstaddr; //目的IP地址
}IPHEADER;

//计算检验和
unsigned short checksum(unsigned short *buffer, int size)
{
unsigned long cksum = 0; // 将所有的16数相加
while (size > 1)
{
cksum += *buffer++;
size -= sizeof(unsigned short);
}
if (size) //加上最后一个BYTE
{
cksum += *(unsigned char*)buffer;
}
while (cksum>>16)
{
cksum = (cksum & 0xffff) + (cksum >> 16);
}
return (unsigned short)~cksum;
}

int main()
{
WSADATA wsadata;
if(WSAStartup(MAKEWORD(2,2),&wsadata)!=0)
{
printf("初始化socket dll失败\n");
return 1;
}
//设置ICMP首部内容
ICMPHEADER icmp_hdr;
icmp_hdr.type=8;
icmp_hdr.code=0;
icmp_hdr.checknum=0;
icmp_hdr.id=(unsigned short)GetCurrentProcessId();
icmp_hdr.seq_num=0;
//计算检验和
icmp_hdr.checknum=checksum((unsigned short*)&icmp_hdr,sizeof(icmp_hdr));
//设置原始套接字
SOCKET sock=WSASocket(AF_INET,SOCK_RAW,IPPROTO_ICMP,NULL,0,0);
if(INVALID_SOCKET==sock)
{
printf("创建socket失败\n");
WSACleanup();
return 1;
}
int ttl=255;
//设置TTL为255
if(setsockopt(sock,IPPROTO_IP,IP_TTL,(const char*)&ttl,sizeof(ttl))==SOCKET_ERROR)
{
printf("set TTL error!\n");
WSACleanup();
return 2;
}
//目标地址
SOCKADDR_IN Dest_addr;
memset(&Dest_addr,0,sizeof(Dest_addr));
Dest_addr.sin_family=AF_INET;
Dest_addr.sin_addr.S_un.S_addr=inet_addr("192.168.1.1");
//发送ICMP请求报文
int status=sendto(sock,(const char*)&icmp_hdr,sizeof(icmp_hdr),0,(SOCKADDR*)&Dest_addr,sizeof(Dest_addr));
if(SOCKET_ERROR==status)
{
printf("sent error!\n");
shutdown(sock,SD_BOTH);
closesocket(sock);
WSACleanup();
return 3;
}
int size=60+sizeof(ICMPHEADER);
char *buffer=(char*)malloc(size);
memset(buffer,0,size);
int des=sizeof(SOCKADDR_IN);
//接受ICMP回应报文并分析
while (true)
{
recvfrom(sock,buffer,size,0,(SOCKADDR*)&Dest_addr,&des);
ICMPHEADER *p=(ICMPHEADER*)((char*)buffer+((IPHEADER*)buffer)->ihl*4);
if(p->type==0)
{
if(p->id==icmp_hdr.id)
{
printf("ping %s成功\n",inet_ntoa(Dest_addr.sin_addr));
break;
}
}
else
{
printf("ping %s不成功\n",inet_ntoa(Dest_addr.sin_addr));
break;
}
}
shutdown(sock,SD_BOTH);
closesocket(sock);
WSACleanup();
return 0;
}