网卡流量探测器

只是一个简单的demo

可以优化的更好

(思路: 上行展示, 下行展示)

// NetSpeed.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <pcap.h>
#include <remote-ext.h>
#include <Winsock2.h>
#pragma comment(lib,"wpcap.lib")
#pragma comment(lib,"ws2_32.lib")

timeval timebegin={0};
timeval timeend={0};
int ktime = 0;
int Capturelen = 0;
/* packet handler 函数原型 */
void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data);

main()
{
pcap_if_t *alldevs;
pcap_if_t *d;
int inum;
int i=0;
pcap_t *adhandle;
char errbuf[PCAP_ERRBUF_SIZE];
    
    /* 获取本机设备列表 */
    if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf) == -1)
    {
        fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
        return 0;
    }
    
    /* 打印列表 */
    for(d=alldevs; d; d=d->next)
    {
        printf("%d. %s", ++i, d->name);
        if (d->description)
            printf(" (%s)\n", d->description);
        else
            printf(" (No description available)\n");
    }
    
    if(i==0)
    {
        printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
        return -1;
    }
    
    printf("Enter the interface number (1-%d):",i);
    scanf("%d", &inum);
    
    if(inum < 1 || inum > i)
    {
        printf("\nInterface number out of range.\n");
        /* 释放设备列表 */
        pcap_freealldevs(alldevs);
        return -1;
    }
    
    /* 跳转到选中的适配器 */
    for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++);
    
    /* 打开设备 */
    if ( (adhandle= pcap_open(d->name,          // 设备名
                              65536,            // 65535保证能捕获到不同数据链路层上的每个数据包的全部内容
							     PCAP_OPENFLAG_PROMISCUOUS,    // 混杂模式
                              1000,             // 读取超时时间
                              NULL,             // 远程机器验证
                              errbuf            // 错误缓冲池
                              ) ) == NULL)
    {
        fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name);
        /* 释放设备列表 */
        pcap_freealldevs(alldevs);
        return -1;
    }
    
    printf("\nlistening on %s...\n", d->description);
    
    /* 释放设备列表 */
    pcap_freealldevs(alldevs);
    
    /* 开始捕获 */
    pcap_loop(adhandle, 0, packet_handler, NULL);
    
    return 0;
}


/* 每次捕获到数据包时，libpcap都会自动调用这个回调函数 */
void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data)
{
    struct tm *ltime;
    char timestr[16];
    time_t local_tv_sec;
	if(ktime == 0)
	{
		 timebegin = header->ts;
		 timeend = header->ts;
		 ktime++;
		 return;
	}
	timeend = header->ts;
    /* 将时间戳转换成可识别的格式 */
    local_tv_sec = header->ts.tv_sec;
    ltime=localtime(&local_tv_sec);
    strftime( timestr, sizeof timestr, "%H:%M:%S", ltime);
    //printf("%s,%.6d len:%d\n", timestr, header->ts.tv_usec, header->len);
    
	 Capturelen += header->caplen;
	/*
	float timeSec  = (float)header->ts.tv_sec + (header->ts.tv_usec/1000);
	printf("sec: %d , microsec %d \n",header->ts.tv_sec,header->ts.tv_usec);
	printf("len: %d , time: %.1f \n",Capturelen,timeSec);
	*/
	int timeSec = (timeend.tv_sec-timebegin.tv_sec)*1000000 + timeend.tv_usec - timebegin.tv_usec; 
	
	/*

	*/
	if(timeSec > 1000000)
	{
		float speed  = (float)Capturelen/timeSec*1000000;
		//printf("speed is:  %.1f B/s \n",speed);
		
		if(speed>=0.0 && speed <1024.0)
		{
			printf("speed is:  %.1f B/s \n",speed);
		}else if(speed>=1024.0 && speed< 1024*1024)
		{
			printf("speed is: %.1f KB/s \n",speed/1024);
		}else if(speed>=1024*1024 && speed< 1024*1024*1024)
		{
			printf("speed is: %.1f MB/s \n",speed/1024/1024);
		}
		timebegin = timeend;
		Capturelen = 0;

	}
}