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本帖最后由 风雨网络 于 2013-5-18 20:38 编辑
这个是网上找的代码 怎么改成AU3 的呀!
最简单的方式是在C#里调用cmd的route命令,优点是简单,开发速度快。缺点显而易见,运行效率非常低,添加一条记录可能需要200ms以上。如果添加记录极多的话,这个效率就让人难以接受了。
这里我就讲一下第二种用法,通过调用win api来修改路由表,达到高效率添加的目的。这个问题看似很简单。实际操作起来却遇到很多麻烦。一些细节的描述在网上很少有人提及。
核心函数是:
[DllImport("Iphlpapi.dll")]
[return: MarshalAs(UnmanagedType.U4)]
public static extern int CreateIpForwardEntry(ref MIB_IPFORWARDROW pRoute);
CreateIpForwardEntry 这个函数,入口参数是一个结构,如下所示
[StructLayout(LayoutKind.Sequential)]
public struct MIB_IPFORWARDROW
{
public UInt32 dwForwardDest; //destination IP address.
public UInt32 dwForwardMask; //Subnet mask
public UInt32 dwForwardPolicy; //conditions for multi-path route. Unused, specify 0.
public UInt32 dwForwardNextHop; //IP address of the next hop. Own address?
public UInt32 dwForwardIfIndex; //index of interface
public UInt32 dwForwardType; //route type
public UInt32 dwForwardProto; //routing protocol.
public UInt32 dwForwardAge; //age of route.
public UInt32 dwForwardNextHopAS; //autonomous system number. 0 if not relevant
public int dwForwardMetric1; //-1 if not used (goes for all metrics)
public int dwForwardMetric2;
public int dwForwardMetric3;
public int dwForwardMetric4;
public int dwForwardMetric5;
}
我们把上面这个api函数稍微改造一下,适合C#调用
public static int createIpForwardEntry(UInt32 destIPAddress, UInt32 destMask, UInt32 nextHopIPAddress, UInt32 ifIndex, int metric)
{
MIB_IPFORWARDROW mifr = new MIB_IPFORWARDROW();
mifr.dwForwardDest = destIPAddress;
mifr.dwForwardMask = destMask;
mifr.dwForwardNextHop = nextHopIPAddress;
mifr.dwForwardIfIndex = ifIndex;
mifr.dwForwardPolicy = Convert.ToUInt32(0);
mifr.dwForwardType = Convert.ToUInt32(4);
mifr.dwForwardProto = Convert.ToUInt32(3);
mifr.dwForwardAge = Convert.ToUInt32(0);
mifr.dwForwardNextHopAS = Convert.ToUInt32(0);
mifr.dwForwardMetric1 = metric;
mifr.dwForwardMetric2 = -1;
mifr.dwForwardMetric3 = -1;
mifr.dwForwardMetric4 = -1;
mifr.dwForwardMetric5 = -1;
return CreateIpForwardEntry(ref mifr);
}
其中 mifr.dwForwardDest 是ip地址,
mifr.dwForwardMask 是子网掩码。
mifr.dwForwardNextHop 是网关地址
以上三个参数比较好理解和使用,有一个注意点就是这三个参数都是32位无符号整形,我们平时使用的ip地址都是字符串形式的,比如"192.168.0.1",这就涉及到一个ip地址由string转换成uint32过程
ip地址4个字节,无符号32位整形正好能够保存ip的所有数据
//IP转换成数字地址
public static uint IPToInt(string ipAddress)
{
string disjunctiveStr = ".,:";
char[] delimiter = disjunctiveStr.ToCharArray();
string[] startIP = null;
for (int i = 1; i <= 5; i++)
{
startIP = ipAddress.Split(delimiter, i);
}
string a1 = startIP[0].ToString();
string a2 = startIP[1].ToString();
string a3 = startIP[2].ToString();
string a4 = startIP[3].ToString();
uint U1 = uint.Parse(a1);
uint U2 = uint.Parse(a2);
uint U3 = uint.Parse(a3);
uint U4 = uint.Parse(a4);
uint U = U4 << 24;
U += U3 << 16;
U += U2 << 8;
U += U1;
return U;
}
转换函数如上,需要注意的是msdn上明确指出,转换的ip地址,需要是低字节在前,就是说192.168.0.1这个ip地址,最后的0x01要放在uint的32位的前面8个字节上。
问题最大的就是 dwForwardIfIndex 和 dwForwardMetric1 这两个参数如何获得
方法如下:
uint forwardMetric = 0;
int pdwSize = 20000;
pIPForwardTable = new byte[pdwSize];
iphlpapi.GetIpForwardTable(pIPForwardTable, out pdwSize, true);
ForwardIfIndex = pIPForwardTable[20];
以上代码获得ForwardIfIndex 的值,这个值被存放在 pIPForwardTable 下标为20的地方 囧
可以参考 参考链接 这个非常隐蔽。
[DllImport("Iphlpapi.dll")]
public static extern uint GetIpInterfaceEntry(ref MIB_IPINTERFACE_ROW pRoute);
[DllImport("iphlpapi.dll", CharSet = CharSet.Auto)]
public static extern int GetBestInterface(UInt32 DestAddr, out UInt32 BestIfIndex);
iphlpapi.GetBestInterface(GetNetworkInfo.IPToInt(strIP), out interfaceIndex);
iphlpapi.MIB_IPINTERFACE_ROW aRow = new iphlpapi.MIB_IPINTERFACE_ROW();
aRow.Family = 2;
aRow.InterfaceLuid = 0;
aRow.InterfaceIndex = interfaceIndex;
//GetIpInterfaceEntry is available in Vista/2008 server or higher
uint errorCode = iphlpapi.GetIpInterfaceEntry(ref aRow);
if (errorCode != 0)
{
AppendRichTextBox("Can't get Metric number");
sr.Close();
return;
}
forwardMetric = aRow.Metric;
以上代码可以获得 forwardMetric 的值,这样,所有参数就都全了,最终调用:
if (iphlpapi.createIpForwardEntry(GetNetworkInfo.IPToInt(strIP),
GetNetworkInfo.IPToInt(SubnetMask),
GetNetworkInfo.IPToInt(defaultGateway), ForwardIfIndex, (int)forwardMetric + 5) != 0)
{
//添加错误
}
forwardMetric 最终要加上一个offset,不能比 aRow.Metric 小
要删除记录,那就比较简单了,把结构当中的 mifr.dwForwardMetric1 = -1 即可
public static int deleteIpForwardEntry(UInt32 destIPAddress, UInt32 destMask, UInt32 nextHopIPAddress, UInt32 ifIndex)
{
MIB_IPFORWARDROW mifr = new MIB_IPFORWARDROW();
mifr.dwForwardDest = destIPAddress;
mifr.dwForwardMask = destMask;
mifr.dwForwardNextHop = nextHopIPAddress;
mifr.dwForwardIfIndex = ifIndex;
mifr.dwForwardPolicy = Convert.ToUInt32(0);
mifr.dwForwardType = Convert.ToUInt32(4);
mifr.dwForwardProto = Convert.ToUInt32(3);
mifr.dwForwardAge = Convert.ToUInt32(0);
mifr.dwForwardNextHopAS = Convert.ToUInt32(0);
mifr.dwForwardMetric1 = -1;
mifr.dwForwardMetric2 = -1;
mifr.dwForwardMetric3 = -1;
mifr.dwForwardMetric4 = -1;
mifr.dwForwardMetric5 = -1;
return DeleteIpForwardEntry(ref mifr);
}
以上的做法虽然有点复杂,但是好处是显而易见的,运行效率非常高,运行createIpForwardEntry方法几百次仅仅需要不到1s的时间。 |
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