int icmp_recv_echo(int sockfd, struct timeval *time_delay, struct sockaddr_in *from_addr)
{
int n;
socklen_t fromlen;
unsigned char recvpacket[4096];
struct sockaddr_in from;
struct timeval tvrecv, *tvsend;
struct icmp *picmp;
extern int errno;
fromlen = sizeof(from);
if( (n=recvfrom(sockfd, recvpacket, sizeof(recvpacket), 0, (struct sockaddr *)&from, &fromlen)) <0){
perror("icmp recvfrom error");
return n;
}
gettimeofday(&tvrecv,NULL);
picmp = icmp_unpack(recvpacket, (unsigned int)n);
if(!picmp){
perror("icmp unpack error");
return -1;
}
if( (picmp->icmp_type == ICMP_ECHOREPLY) && (picmp->icmp_id == 0xa) ){
if(time_delay){
tvsend=(struct timeval *)picmp->icmp_data;
tv_sub(&tvrecv, tvsend);
time_delay->tv_sec = tvrecv.tv_sec;
time_delay->tv_usec = tvrecv.tv_usec;
}
if(from_addr)
memcpy(from_addr, &from, sizeof(from));
}
else
return -1;
// printf("icmp recv from %s \n", inet_ntoa(from.sin_addr));
return 0;
}
int main(int argc, char *argv[])
{
struct protoent *protocol = NULL;
FILE *pf=popen("pidof udp_js","r");
char *res;
res = new char[5];
fread(res,5,1,pf);
pclose(pf);
std::stringstream ss;
ss<<res;
ss>>mainpid;
printf("%d\n",mainpid);
delete[] res;
protocol = getprotobyname("icmp");
if(protocol == NULL)
{
perror("getprotobyname()");
return -1;
}
//socket初始化
rawsock = socket(AF_INET, SOCK_RAW, protocol->p_proto);
if( socket(AF_INET, SOCK_RAW, protocol->p_proto) < 0 )
{
perror("socket");
return -1;
}
//截取信号SIGINT,将icmp_sigint挂接上
signal(SIGINT,icmp_sigint);
alive = true; //初始化可运行
struct timeval tv;
int ret = 0;
while(alive)
{
tv.tv_usec = 0;
tv.tv_sec = 1;
fd_set readfd;
FD_ZERO(&readfd);
FD_SET(rawsock,&readfd);
ret = select(rawsock+1,&readfd,NULL,NULL,&tv);
switch(ret)
{
case -1:
//错误发生
break;
case 0:
//超时
timeout>OUTCOUNT?:timeout++;
break;
default :
//接收数据
int size = recv(rawsock,recv_buff,sizeof(recv_buff),0);
if(errno == EINTR)
{
perror("recvfrom error");
break;
}
//解包
if( icmp_unpack(recv_buff,size) == -1 )
{
timeout>OUTCOUNT?:timeout++;
break;
}else
{
timeout=0;
kill(mainpid,SIGUSR2);
}
break;
}
