ping.c

一个通过无线设备传输文件程序主要涉及内容是网络通信和RS232设置

/*
* Copyright (c) 2004,wuxi xietong tech corp
* All rights reserved.
*
* filename：hc_key.c
* content ：key dispatch for HC
*
* version  ：2.0
* author   ：hwz
* date     ：2004/03/01
*
*/
#include "common.h"
#include "hc.h"
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <time.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/wait.h>
#include <string.h>
#include <stdarg.h>
#include <netdb.h>
#include <netinet/ip_icmp.h>
#include <math.h>
#include <netinet/in.h>


void hc_key_sock_init(void);
int ping_four(void);
int ping_test(void);
int unpackip(char *buf,int len);
unsigned short cal_chksum(unsigned short *addr,int len);
void ping(void);
int	sock_pings;
struct sockaddr_un	addr_rec;
struct sockaddr_un 	addr_wtdog;


//#define SEVR_ADDR       "192.168.0.87"
#define SEVR_ADDR       "172.29.1.14"
#define TIMEL		3	

int main(void)
{
	struct hc_event_msg_str msg;
	time_t now_time=0;
        time_t last_time=0;
        int pingret=-1;
	int count=0;
	int count_ok=0;
	int once=1;

	err_dump_init("/tmp/ping.log");
	set_sighandler();
	hc_global_init();
	hc_key_sock_init();

	DEBUG_DUMP("begin while ...");
	while(1){
	    	now_time = time(NULL);
            	if( (now_time-last_time) >= TIMEL) {
                	pingret = ping_four();
                	if(pingret == 0) {
                        	count = 0;
				if(once ==1)
					count_ok = 1;
                	} else {
				count_ok = 0;
                        	count++;
                	}
                	last_time = now_time;
                	err_dump(PRINT_ERROR,"***********msg.event_key = %d\n",count);
		}

		if(count == 2){
			msg.type = HC_EVENT_TYPE_KEY;
                	msg.event_key = -1;
                	sendto(sock_pings, (char *)&msg, sizeof(msg), 0,
                            (struct sockaddr *)&addr_rec, sizeof(addr_rec));
			count = 0;
			once=1;
		}
		if(count_ok == 1) {
			msg.type = HC_EVENT_TYPE_KEY;
			msg.event_key=0;
			sendto(sock_pings, (char *)&msg, sizeof(msg), 0,
                            (struct sockaddr *)&addr_rec, sizeof(addr_rec));
			once=0;
			count_ok=0;
		}
	}
	close(sock_pings);
	return 0;		
}

void hc_key_sock_init()
{
	int	ret, on=1;
	struct sockaddr_un      addr_un;
	

	unlink(HC_KEY_SOCK);
	sock_pings = socket(PF_UNIX, SOCK_DGRAM, 0);
        setsockopt(sock_pings, SOL_SOCKET, SO_REUSEADDR,(char *)&on, sizeof(on));
        addr_un.sun_family = AF_UNIX;
        strcpy(addr_un.sun_path, HC_KEY_SOCK);
        ret = bind(sock_pings, (struct sockaddr *)&addr_un, sizeof(addr_un));
        if( ret<0 ){
                ERR_DUMP();
                exit(-1);
        }

	addr_rec.sun_family = AF_UNIX;
        strcpy(addr_rec.sun_path, HC_EVENT_GENERAL_SOCK);	

	addr_wtdog.sun_family = AF_UNIX;
	strcpy(addr_wtdog.sun_path, HC_EVENT_WTDOG_SOCK);

}


int     sock_ping;
int     datalen =56;
int     seq =0;
int     iTimeOut = 1;
char    message_buf[256];
struct  sockaddr_in send_addr;

unsigned short cal_chksum(unsigned short *addr,int len)
{       int nleft=len;
        int sum=0;
        unsigned short *w=addr;
        unsigned short answer=0;

        while(nleft>1)
        {       sum+=*w++;
                nleft-=2;
        }
        if( nleft==1)
        {       *(unsigned char *)(&answer)=*(unsigned char *)w;
                sum+=answer;
        }
        sum=(sum>>16)+(sum&0xffff);
        sum+=(sum>>16);
        answer=~sum;
        return answer;
}
void ping(void)
{
        int  len;
        struct icmphdr *icmp;

        icmp = (struct icmphdr*)message_buf;
        icmp->type = ICMP_ECHO;
        icmp->code = 0;
        icmp->un.echo.sequence = seq++;
        icmp->un.echo.id = getpid();
        gettimeofday((struct timeval *)(icmp+1), NULL);
        len=datalen+8;
        icmp->checksum = 0;
        icmp->checksum = cal_chksum((unsigned short*)icmp, len);
        len =sendto(sock_ping, message_buf, len, 0, (struct sockaddr*)&send_addr, sizeof(send_addr));
        if (len < 0){
                err_dump(PRINT_ERROR,"send_to error\n");
        }
}

int unpackip(char *buf,int len)
{
        int iphdrlen;
        struct ip *ip;
        struct icmp *icmp;
/*
	struct timeval *tvs;
        struct timeval tvr;
        double rrt;
*/

        ip=(struct ip *)buf;
        iphdrlen=ip->ip_hl<<2;
        icmp=(struct icmp *)(buf+iphdrlen);
        len-=iphdrlen;
        if( len<8)
        {
              err_dump(PRINT_ERROR, "ICMP packets\'s length is less than 8\n");
                return -1;
        }
       if( (icmp->icmp_type==ICMP_ECHOREPLY)){
/*		gettimeofday(&tvr,NULL);
                tvs=(struct timeval*)(icmp+1);
                hdtv(&tvr,tvs);
                rrt = tvr.tv_sec*1000.0+tvr.tv_usec/1000.0;
                err_dump(PRINT_ERROR,"**************rtt:%.3fms\n",rrt);
*/
                return 0;
	}else
               return -1;
	return 0;
}

int ping_test(void)
{
        int size;
        int ret;

        if ((sock_ping = socket(AF_INET,SOCK_RAW,IPPROTO_ICMP)) < 0){
                err_dump(PRINT_ERROR,"socket\n");
                return -1;
        }

        bzero(&send_addr,sizeof(send_addr));
        send_addr.sin_family = AF_INET;
        send_addr.sin_addr.s_addr =  inet_addr(SEVR_ADDR);

        seq = 0;

        ping();

	usleep(200);
        size = recvfrom(sock_ping, message_buf, sizeof(message_buf), MSG_DONTWAIT, NULL, NULL);


//        size = recvfrom(sock_ping, message_buf, sizeof(message_buf), 0, NULL, NULL);
        if( size<=0 ) {
                close( sock_ping );
//                err_dump(PRINT_ERROR," size<=0\n");
                return -1;
        }
        ret = unpackip(message_buf, size);
        if( ret<0 ){
//                err_dump(PRINT_ERROR,"ret=unpackip<0 \n");
                close( sock_ping );
                return -1;
        }


        close( sock_ping );
        return 0;
}

int ping_four(void)
{
        int i;
        int count;
        int ret;

        for(i=0;i<10;i++){
                count = 8;
rep:            ret = ping_test();
                if (ret != 0) {
//                        err_dump(PRINT_ERROR,"ping fail count:%d\n",count);
                        count --;
                        if (count > 0)
                                goto rep;
                        return -1;
                }else{
//                        err_dump(PRINT_ERROR,"ping ok count:%d\n",count);
                        break;
                }
        }
        return 0;
}