asp.Net防類似DDOS攻撃(CC攻撃)コード
Web.config
コード:
コード:
using System
;
using System
.Web
;
using System
.Collections
.Generic
;
using System
.Collections
.Specialized
;
using System
.Timers
;
namespace UrlRewriter
{
/// <summary>
/// IP
/// </summary>
public
class
DosAttackModule :
IHttpModule
{
void
IHttpModule.Dispose
(
)
{
}
void
IHttpModule.Init
(
HttpApplication context)
{
context.BeginRequest
+=
new
EventHandler(
context_BeginRequest)
;
}
private
static
Dictionary<
string, short>
_IpAdresses =
new
Dictionary<
string, short>
(
)
;
private
static
Stack<
string>
_Banned =
new
Stack<
string>
(
)
;
private
static
Timer
_Timer =
CreateTimer(
)
;
private
static
Timer
_BannedTimer =
CreateBanningTimer(
)
;
private
const
int
BANNED_REQUESTS =
1
;
//
private
const
int
REDUCTION_INTERVAL =
1000
;
// 1 （ ）
private
const
int
RELEASE_INTERVAL =
5
*
60
*
1000
;
// 5 （ IP ）
private
void
context_BeginRequest(
object sender, EventArgs e)
{
string ip =
HttpContext.Current
.Request
.UserHostAddress
;
if
(
_Banned.Contains
(
ip)
)
{
HttpContext.Current
.Response
.StatusCode
=
403
;
HttpContext.Current
.Response
.End
(
)
;
}
CheckIpAddress(
ip)
;
}
/// <summary>
/// IP
/// </summary>
private
static
void
CheckIpAddress(
string ip)
{
if
(
!
_IpAdresses.ContainsKey
(
ip)
)
// IP 1
{
_IpAdresses[
ip]
=
1
;
}
else
if
(
_IpAdresses[
ip]
==
BANNED_REQUESTS)
// IP “ ”
{
_Banned.Push
(
ip)
;
_IpAdresses.Remove
(
ip)
;
}
else
// 1
{
_IpAdresses[
ip]
++;
}
}
#region Timers
/// <summary>
/// ， _IpAddress 。
/// </summary>
private
static
Timer
CreateTimer(
)
{
Timer
timer =
GetTimer(
REDUCTION_INTERVAL)
;
timer.Elapsed
+=
new
ElapsedEventHandler(
TimerElapsed)
;
return
timer;
}
/// <summary>
/// ， IP
/// </summary>
/// <returns></returns>
private
static
Timer
CreateBanningTimer(
)
{
Timer
timer =
GetTimer(
RELEASE_INTERVAL)
;
timer.Elapsed
+=
delegate {
_Banned.Pop
(
)
;
}
;
// IP
return
timer;
}
/// <summary>
/// ，
/// </summary>
/// <param name="interval"> </param>
private
static
Timer
GetTimer(
int
interval)
{
Timer
timer =
new
Timer
(
)
;
timer.Interval
=
interval;
timer.Start
(
)
;
return
timer;
}
/// <summary>
/// IP
/// </summary>
private
static
void
TimerElapsed(
object sender, ElapsedEventArgs e)
{
foreach
(
string key in _IpAdresses.Keys
)
{
_IpAdresses[
key]
--;
if
(
_IpAdresses[
key]
==
0
)
_IpAdresses.Remove
(
key)
;
}
}
#endregion
}
}