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;



	}

}