windows获取系统网络流量

函数

DWORD GetIfTable(
PMIB_IFTABLE pIfTable,
PULONG pdwSize,
BOOL bOrder
);

功能

获取MIB-II接口列表

参数

PMIB_IFTABLE pIfTable：接收缓冲区，接收GetIfTable返回的MIB-II接口表

PULONG pdwSize：pIfTable缓冲区字节数，若缓冲区过小则返回所需大小

BOOL bOrder：指定pIfTable中返回的接口列表条目是否根据接口索引排序

MIB_IFTABLE结构体

typedef struct _MIB_IFTABLE {
  DWORD     dwNumEntries;
  MIB_IFROW table[ANY_SIZE];
} MIB_IFTABLE, *PMIB_IFTABLE;

typedef struct _MIB_IFROW {
  WCHAR wszName[MAX_INTERFACE_NAME_LEN];
  DWORD dwIndex;
  DWORD dwType;
  DWORD dwMtu;
  DWORD dwSpeed;
  DWORD dwPhysAddrLen;
  BYTE  bPhysAddr[MAXLEN_PHYSADDR];
  DWORD dwAdminStatus;
  DWORD dwOperStatus;
  DWORD dwLastChange;
  DWORD dwInOctets;
  DWORD dwInUcastPkts;
  DWORD dwInNUcastPkts;
  DWORD dwInDiscards;
  DWORD dwInErrors;
  DWORD dwInUnknownProtos;
  DWORD dwOutOctets;
  DWORD dwOutUcastPkts;
  DWORD dwOutNUcastPkts;
  DWORD dwOutDiscards;
  DWORD dwOutErrors;
  DWORD dwOutQLen;
  DWORD dwDescrLen;
  BYTE  bDescr[MAXLEN_IFDESCR];
} MIB_IFROW, *PMIB_IFROW;

http://msdn.microsoft.com/en-us/library/windows/desktop/aa366836(v=vs.85).aspx

返回值

成功返回NO_ERROR，否则返回值即错误码

头文件和引用库

#include <IPHlpApi.h>
#pragma comment(lib, "IPHlpApi.lib")

使用方法

/*获取MIB-II接口表大小*/
DWORD dwBufferLen = 0;
GetIfTable(NULL, &dwBufferLen, 0); 

/*创建MIB-II接口表*/
PMIB_IFTABLE pMibIfTable = (MIB_IFTABLE*)malloc(dwBufferLen);

/*获取MIB-II接口表*/
DWORD dwRet = GetIfTable(pMibIfTable, &dwBufferLen, 0);
if(NO_ERROR != dwRet)
{
	std::cout<<"GetIfTable != NO_ERROR, ErrorCode="<<dwRet<<std::endl;
	free(pMibIfTable);
	return false;
}

细说MIB_IFROW结构体成员

dwType：接口类型，例如IF_TYPE_ETHERNET_CSMACD=6, Ethernet网络接口；IF_TYPE_SOFTWARE_LOOPBACK=24，软件回环测试网络接口。23号之前的网络接口可用来统计系统流量。

dwSpeed：接口速度，单位bps，可用来计算网络带宽

bPhysAddr：接口网卡的MAC地址

dwInOctets：接收的字节数，自系统启动，可用来统计系统网络流量。
dwOutOctets：发送的字节数，自系统启动，可用来统计系统网络流量。

获取网络带宽

bool GetNetworkBandwithByMidTable(int &iMbsBandwidth)
{
	/*获取MIB-II接口表大小*/
	DWORD dwBufferLen = 0;
	GetIfTable(NULL, &dwBufferLen, 0); 

	/*创建MIB-II接口表*/
	PMIB_IFTABLE pMibIfTable = (MIB_IFTABLE*)malloc(dwBufferLen);

	/*获取MIB-II接口表*/
	DWORD dwRet = GetIfTable(pMibIfTable, &dwBufferLen, 0);
	if(NO_ERROR != dwRet)
	{
		std::cout<<"GetIfTable != NO_ERROR, ErrorCode="<<dwRet<<std::endl;
		free(pMibIfTable);
		return false;
	}

	iMbsBandwidth = INT_MAX;

	/*多网卡*/
	for(int i = 0; i != pMibIfTable->dwNumEntries; ++i)
	{
		if (pMibIfTable->table[i].dwType <= 23)
		{
			int iTmp = static_cast<int>(pMibIfTable->table[i].dwSpeed/1000/1000);
			if(iTmp != 0 && iTmp < iMbsBandwidth)
				iMbsBandwidth = iTmp;
		}
	}

	free(pMibIfTable);
	if(iMbsBandwidth == INT_MAX)
		return false;
	return true;
}

网卡的传输速度有10Mbps、100Mbps、1000Mbps，查看网卡速度的方法：设备管理器—网络适配器—选择网卡—属性—高级—连接速度和双工模式—值—下拉菜单中的最大值。

网络带宽由多种因素决定，例如为连接在只具备100M传输速度的双绞线上的计算机配置1000M的网卡就是一种浪费，因为其至多也只能实现100M的传输速率。

故网络带宽为各种物理介质中的最小值，可认为是所有网卡传输速度的最小值（且不为0）。

获取发送比特数和接收比特数，自系统启动

bool GetStatisticOfSysNetworkFlow(DWORD &dwbitTotalRecv, DWORD &dwbitTotalSend)
{
	/*获取MIB-II接口表大小*/
	DWORD dwBufferLen = 0;
	GetIfTable(NULL, &dwBufferLen, 0); 

	/*创建MIB-II接口表*/
	PMIB_IFTABLE pMibIfTable = (MIB_IFTABLE*)malloc(dwBufferLen);

	/*获取MIB-II接口表*/
	DWORD dwRet = GetIfTable(pMibIfTable, &dwBufferLen, 0);
	if(NO_ERROR != dwRet)
	{
		std::cout<<"GetIfTable != NO_ERROR, ErrorCode="<<dwRet<<std::endl;
		free(pMibIfTable);
		return false;
	}

	dwbitTotalRecv = dwbitTotalSend = 0;

	/*多网卡*/
	for(int i = 0; i != pMibIfTable->dwNumEntries; ++i)
	{
		if (pMibIfTable->table[i].dwType <= 23)
		{
			dwbitTotalRecv += pMibIfTable->table[i].dwInOctets;
			dwbitTotalSend += pMibIfTable->table[i].dwOutOctets;
		}
	}

	/*Byte转bit*/
	dwbitTotalRecv *= 8;
	dwbitTotalSend *= 8;

	free(pMibIfTable);
	return true;
}

计算每秒发送比特数和每秒接收比特数

bool GetSysNetworkFlowByMidTable(DWORD &dwbpsRecv, DWORD &dwbpsSend)
{
	/*首次获取*/
	DWORD dwTotalRecv1 = 0, dwTotalSend1 = 0;
	if(!GetStatisticOfSysNetworkFlow(dwTotalRecv1, dwTotalSend1))
	{
		printf("GetStatisticOfSysNetworkFlow == false
");
		return false;
	}

	Sleep(1000);

	/*再取*/
	DWORD dwTotalRecv2 = 0, dwTotalSend2 = 0;
	if(!GetStatisticOfSysNetworkFlow(dwTotalRecv2, dwTotalSend2))
	{
		printf("GetStatisticOfSysNetworkFlow == false
");
		return false;
	}

	/*计算*/
	dwbpsRecv = dwTotalRecv2 - dwTotalRecv1;
	dwbpsSend = dwTotalSend2 - dwTotalSend1;

	return true;
}

注：Windows Performance Counter性能计数器的Network Interface对象能够获取系统网络数据，经验证在Win7下Performance Counter可能不存在Network Interface对象，导致程序运行失败。