连接过滤器

关键字: 屏蔽IP, 禁止IP, 屏蔽连接， 连接过滤，黑名单，白名单

SuperSocket 中的连接过滤器是一个用于过滤客户端连接的接口。 通过连接过滤器，你可以允许或者禁止从某些地址过来的连接。

连接过滤器的接口定义如下：

  1. /// <summary>
  2. /// The basic interface of connection filter
  3. /// </summary>
  4. public interface IConnectionFilter
  5. {
  6.     /// <summary>
  7.     /// Initializes the connection filter
  8.     /// </summary>
  9.     /// <param name="name">The name.</param>
  10.     /// <param name="appServer">The app server.</param>
  11.     /// <returns></returns>
  12.     bool Initialize(string name, IAppServer appServer);
  14.     /// <summary>
  15.     /// Gets the name of the filter.
  16.     /// </summary>
  17.     string Name { get; }
  19.     /// <summary>
  20.     /// Whether allows the connect according the remote endpoint
  21.     /// </summary>
  22.     /// <param name="remoteAddress">The remote address.</param>
  23.     /// <returns></returns>
  24.     bool AllowConnect(IPEndPoint remoteAddress);
  25. }

bool Initialize(string name, IAppServer appServer);

此方法用于初始化连接过滤器

string Name {get;}

返回连接过滤器名称

bool AllowConnect (IPEndPoint remoteAddress);

这个方法通过判断客户端的地址来决定是否允许该连接。

下面的代码实现了只允许来自指定IP地址范围的连接的功能:

  1. public class IPConnectionFilter : IConnectionFilter
  2. {
  3.     private Tuple<long, long>[] m_IpRanges;
  5.     public bool Initialize(string name, IAppServer appServer)
  6.     {
  7.         Name = name;
  9.         var ipRange = appServer.Config.Options.GetValue("ipRange");
  11.         string[] ipRangeArray;
  13.         if (string.IsNullOrEmpty(ipRange)
  14.             || (ipRangeArray = ipRange.Split(new char[] { ',', ';' }, StringSplitOptions.RemoveEmptyEntries)).Length <= 0)
  15.         {
  16.             throw new ArgumentException("The ipRange doesn't exist in configuration!");
  17.         }
  19.         m_IpRanges = new Tuple<long, long>[ipRangeArray.Length];
  21.         for (int i = 0; i < ipRangeArray.Length; i++)
  22.         {
  23.             var range = ipRangeArray[i];
  24.             m_IpRanges[i] = GenerateIpRange(range);
  25.         }
  27.         return true;
  28.     }
  30.     private Tuple<long, long> GenerateIpRange(string range)
  31.     {
  32.         var ipArray = range.Split(new char[] { '-' }, StringSplitOptions.RemoveEmptyEntries);
  34.         if(ipArray.Length != 2)
  35.             throw new ArgumentException("Invalid ipRange exist in configuration!");
  37.         return new Tuple<long, long>(ConvertIpToLong(ipArray[0]), ConvertIpToLong(ipArray[1]));
  38.     }
  40.     private long ConvertIpToLong(string ip)
  41.     {
  42.         var points = ip.Split(new char[] { '.' }, StringSplitOptions.RemoveEmptyEntries);
  44.         if(points.Length != 4)
  45.             throw new ArgumentException("Invalid ipRange exist in configuration!");
  47.         long value = 0;
  48.         long unit = 1;
  50.         for (int i = points.Length - 1; i >= 0; i--)
  51.         {
  52.             value += unit * points[i].ToInt32();
  53.             unit *= 256;
  54.         }
  56.         return value;
  57.     }
  59.     public string Name { get; private set; }
  61.     public bool AllowConnect(IPEndPoint remoteAddress)
  62.     {
  63.         var ip = remoteAddress.Address.ToString();
  64.         var ipValue = ConvertIpToLong(ip);
  66.         for (var i = 0; i < m_IpRanges.Length; i++)
  67.         {
  68.             var range = m_IpRanges[i];
  70.             if (ipValue > range.Item2)
  71.                 return false;
  73.             if (ipValue < range.Item1)
  74.                 return false;
  75.         }
  77.         return true;
  78.     }
  79. }

然后你需要更新配置文件来启用这个连接过滤器:

1) 添加配置节点 "connectionFilters":

  1. <connectionFilters>
  2.   <add name="IpRangeFilter"
  3.        type="SuperSocket.QuickStart.ConnectionFilter.IPConnectionFilter, SuperSocket.QuickStart.ConnectionFilter" />
  4. </connectionFilters>

2) 为server实例添加connectionFilter属性:

<server name="EchoServer"
        serverTypeName="EchoService" ip="Any" port="2012"
        connectionFilter="IpRangeFilter"
        ipRange="127.0.1.0-127.0.1.255">
</server>

3) 完整的配置文件如下:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <section name="superSocket" type="SuperSocket.SocketEngine.Configuration.SocketServiceConfig, SuperSocket.SocketEngine"/>
    </configSections>
    <appSettings>
        <add key="ServiceName" value="EchoService"/>
    </appSettings>
    <superSocket>
        <servers>
            <server name="EchoServer"
                serverTypeName="EchoService"
                ip="Any" port="2012"
                connectionFilter="IpRangeFilter"
                ipRange="127.0.1.0-127.0.1.255">
            </server>
        </servers>
       <serverTypes>
           <add name="EchoService"
                type="SuperSocket.QuickStart.EchoService.EchoServer, SuperSocket.QuickStart.EchoService" />
       </serverTypes>
       <connectionFilters>
           <add name="IpRangeFilter"
                type="SuperSocket.QuickStart.ConnectionFilter.IPConnectionFilter, SuperSocket.QuickStart.ConnectionFilter" />
       </connectionFilters>
    </superSocket>
    <startup>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
    </startup>
</configuration>