参照ipconflict程序写的简单的ping 程序

ipconflict 的参照地址   http://blog.csdn.net/stpeace/article/details/44626287

http://blog.csdn.net/codeheng/article/details/51240231

#include <stdio.h>

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/time.h>
#include <netinet/ip_icmp.h>
#include <unistd.h>
#include <signal.h>


#define MAX_SIZE 1024


char send_buf[MAX_SIZE];
char recv_buf[MAX_SIZE];
int nsend = 0,nrecv = 0;
int datalen = 56;


//统计结果
void statistics(int signum)
{
printf("\n----------------PING statistics---------------\n");
printf("%d packets transmitted,%d recevid,%%%.2f lost\n",nsend,nrecv,(float)(nsend - nrecv)/nsend * 100);
exit(EXIT_SUCCESS);
}


//校验和算法
int calc_chsum(unsigned short *addr,int len)
{
int sum = 0,n = len;
unsigned short answer = 0;
unsigned short *p = addr;

//每两个字节相加
while(n > 1)
{
sum += *p ++;
n -= 2;
}

//处理数据大小是奇数，在最后一个字节后面补0
if(n == 1)
{
*((unsigned char *)&answer) = *(unsigned char *)p;
sum += answer;
}

//将得到的sum值的高2字节和低2字节相加
sum = (sum >> 16) + (sum & 0xffff);

//处理溢出的情况
sum += sum >> 16;
answer = ~sum;


return answer;
}


int pack(int pack_num)
{
int packsize;
struct icmp *icmp;
struct timeval *tv;


icmp = (struct icmp *)send_buf;
icmp->icmp_type = ICMP_ECHO;
icmp->icmp_code = 0;
icmp->icmp_cksum = 0;
icmp->icmp_id = htons(getpid());
icmp->icmp_seq = htons(pack_num);
tv = (struct timeval *)icmp->icmp_data;


//记录发送时间
if(gettimeofday(tv,NULL) < 0)
{
perror("Fail to gettimeofday");
return -1;
}

packsize = 8 + datalen;


icmp->icmp_cksum = calc_chsum((unsigned short *)icmp,packsize);

return packsize;
}


int send_packet(int sockfd,struct sockaddr *paddr)
{
int packsize;

//将send_buf填上a
memset(send_buf,'a',sizeof(send_buf));


nsend ++;
//打icmp包
packsize = pack(nsend);


if(sendto(sockfd,send_buf,packsize,0,paddr,sizeof(struct sockaddr)) < 0)
{
perror("Fail to sendto");
return -1;
}


return 0;
}


struct timeval  time_sub(struct timeval *tv_send,struct timeval *tv_recv)
{
struct timeval ts;


if(tv_recv->tv_usec - tv_send->tv_usec < 0)
{
tv_recv->tv_sec --;
tv_recv->tv_usec += 1000000;
}

ts.tv_sec = tv_recv->tv_sec - tv_send->tv_sec;
ts.tv_usec = tv_recv->tv_usec - tv_send->tv_usec;


return ts;
}


int unpack(int len,struct timeval *tv_recv,struct sockaddr *paddr,char *ipname)
{
struct ip *ip;
struct icmp *icmp;
struct timeval *tv_send,ts;
int ip_head_len;
float rtt;


ip = (struct ip *)recv_buf;
ip_head_len = ip->ip_hl << 2;
icmp = (struct icmp *)(recv_buf + ip_head_len);

len -= ip_head_len;


if(len < 8)
{
printf("ICMP packets\'s is less than 8.\n");
return -1;
}


tv_send = (struct timeval *)icmp->icmp_data;
ts = time_sub(tv_send,tv_recv);
rtt = ts.tv_sec * 1000 + (float)ts.tv_usec/1000;//以毫秒为单位

if(ntohs(icmp->icmp_id) == getpid() && icmp->icmp_type == ICMP_ECHOREPLY)
{
nrecv ++;
printf("%d bytes from %s (%s):icmp_req = %d ttl=%d rtt=%.3fms.\n",
len,ipname,inet_ntoa(((struct sockaddr_in *)paddr)->sin_addr),ntohs(icmp->icmp_seq),ip->ip_ttl,rtt);
}

return 0;
}


int recv_packet(int sockfd,char *ipname)
{
int addr_len ,n;
struct timeval tv;
struct sockaddr from_addr;

addr_len = sizeof(struct sockaddr);
memset(recv_buf,0,sizeof(recv_buf));


if((n = recvfrom(sockfd,recv_buf,sizeof(recv_buf),0,&from_addr,&addr_len)) < 0)
{
perror("Fail to recvfrom");
return -1;
}


if(gettimeofday(&tv,NULL) < 0)
{
perror("Fail to gettimeofday");
return -1;
}


unpack(n,&tv,&from_addr,ipname);


return 0;
}


//myping 192.168.0.1 || myping www.baidu.com
int main(int argc,char *argv[])
{
int size = 50 * 1024;
int sockfd,netaddr;
struct protoent *protocol;
struct hostent *host;
struct sockaddr_in peer_addr;

if(argc < 2)
{
fprintf(stderr,"usage : %s ip.\n",argv[0]);
exit(EXIT_FAILURE);
}

//获取icmp的信息
if((protocol = getprotobyname("icmp")) ==  NULL)
{
perror("Fail to getprotobyname");
exit(EXIT_FAILURE);
}

//创建原始套接字
if((sockfd = socket(AF_INET,SOCK_RAW,protocol->p_proto)) < 0)
{
perror("Fail to socket");
exit(EXIT_FAILURE);
}
#if 0
//回收root权限,设置当前用户权限
setuid(getuid());
#endif 


#if 0
/*
扩大套接子接收缓冲区到50k，这样做主要为了减少接收缓冲区溢出的可能性
若无中意ping一个广播地址或多播地址，将会引来大量应答
*/
if(setsockopt(sockfd,SOL_SOCKET,SO_RCVBUF,&size,sizeof(size)) < 0)
{
perror("Fail to setsockopt");
exit(EXIT_FAILURE);
}
#endif 


//填充对方的地址
bzero(&peer_addr,sizeof(peer_addr));
peer_addr.sin_family = AF_INET;


//判断是主机名(域名)还是ip
if((netaddr = inet_addr(argv[1])) == INADDR_NONE)
{
//是主机名（域名）
if((host = gethostbyname(argv[1])) == NULL)
{
fprintf(stderr,"%s unknown host : %s.\n",argv[0],argv[1]);
exit(EXIT_FAILURE);
}
//&(peer_addr.sin_addr.s_addr)
//strcpy
memcpy((char *)&(peer_addr.sin_addr),host->h_addr,host->h_length);

}else{//ip地址
peer_addr.sin_addr.s_addr = netaddr;
}

//注册信号处理函数
signal(SIGALRM,statistics);
signal(SIGINT,statistics);
alarm(5);


//开始信息
printf("PING %s(%s) %d bytes of data.\n",argv[1],inet_ntoa(peer_addr.sin_addr),datalen);


//发送包文和接收报文
while(1)
{
send_packet(sockfd,(struct sockaddr *)&peer_addr);
recv_packet(sockfd,argv[1]);
alarm(5);
sleep(1);
}


exit(EXIT_SUCCESS);
}