asp.net ： 拒绝频繁的IP访问

//首先我们要实现 IHttpModule接口

using System;

using System.Collections.Generic;

using System.Text;

using System.Web;

using System.Web.UI;

using System.Web.SessionState;

using System.Configuration;

namespace MyHttp

{

    public class UrlReWrite : IHttpModule

    {

        /// <summary>

        /// 单个IP最大连接限制数量

        /// </summary>

        private int rowCount = Convert.ToInt32(ConfigurationSettings.AppSettings["HttpRowCount"]);

        /// <summary>

        /// 指定区域时间范围 单位分

        /// </summary>

        private int httpTime = Convert.ToInt32(ConfigurationSettings.AppSettings["HttpTime"]);

        public void Init(HttpApplication application)

        {

            application.BeginRequest += (new

                 EventHandler(this.Application_BeginRequest));

            application.EndRequest += (new

                 EventHandler(this.Application_EndRequest));

        }

        private void Application_BeginRequest(Object source, EventArgs e)

        {

            HttpApplication Application = (HttpApplication)source;

            HttpContext ctx = Application.Context;

            //IP地址

            string isIp = ctx.Request.UserHostAddress;

            if (ctx.Application["time"] == null)

            {

                ctx.Application["time"] = DateTime.Now;

            }

            else

            {

                DateTime isTime = (DateTime)ctx.Application["time"];

                int timeTract = Convert.ToInt32(DateTime.Now.Subtract(isTime).Minutes.ToString());

                if (timeTract > (httpTime - 1))

                {

                    ctx.Application["time"] = null;

                    ctx.Application["myip"] = null;

                }

            }

            if (ctx.Application["myip"] != null && ctx.Application["myip"] is CartIp)

            {

                CartIp cartIp = (CartIp)ctx.Application["myip"];

                cartIp.Insert(isIp);

                ctx.Application["myip"] = cartIp;

                if (cartIp.GetCount(isIp) > rowCount)

                {

                    ctx.Response.Clear();

                    ctx.Response.Close();

                }

            }

            else

            {

                CartIp cartIp = new CartIp();

                cartIp.Insert(isIp);

                HttpContext.Current.Application["myip"] = cartIp;

            }

        }

        private void Application_EndRequest(Object source, EventArgs e)

        {

        }  

        public void Dispose()

        {

        }

    }

}

 

//ListIp 类

 

using System;

using System.Collections.Generic;

using System.Text;

namespace MyHttp

{

    [Serializable]

    public class ListIp

    {

        private string ip;

        private int count;

        /// <summary>

        /// IP地址

        /// </summary>

        public string IP

        {

            get { return ip; }

            set { ip = value; }

        }

        /// <summary>

        /// 累加数量

        /// </summary>

        public int Count

        {

            get { return count; }

            set { count = value; }

        }

    }

    [Serializable]

    public class CartIp

    {

        public CartIp()

        {

            if (_listIp == null)

            {

                _listIp = new List<ListIp>();

            }

        }

        private List<ListIp> _listIp;

        public List<ListIp> _ListIp

        {

            get { return _listIp; }

            set { _listIp = value; }

        }

        /// <summary>

        /// 添加IP

        /// </summary>

        public void Insert(string ip)

        {

            int indexof = ItemLastInfo(ip);

            if (indexof == -1)

            {

                //不存在

                ListIp item = new ListIp();

                item.IP = ip;

                _listIp.Add(item);

            }

            else

            {

                _listIp[indexof].Count += 1;

            }

        }

        //判断IP是否存在

        public int ItemLastInfo(string ip)

        {

            int index = 0;

            foreach (ListIp item in _ListIp)

            {

                if (item.IP == ip)

                {

                    return index;//存在

                }

                index += 1;

            }

            return -1;//不存在

        }

        /// <summary>

        /// 获得IP的数量

        /// </summary>

        /// <param name="ip"></param>

        /// <returns></returns>

        public int GetCount(string ip)

        {

            foreach (ListIp item in _ListIp)

            {

                if (item.IP == ip)

                {

                    return item.Count;//存在

                }

            }

            return -1;//不存在

        }

    }

}

 

 

//在web.config 配置访问规则

<appSettings>

<add key="HttpRowCount" value="100"/>

<add key="HttpTime" value="10"/>

</appSettings>

 

<system.web>

   <httpModules>

   <add name="UrlReWrite" type="MyHttp.UrlReWrite"/>

  </httpModules>

</system.web>