diff options
* Added a Basic DOS protection container/base object for the most common HTTP Server handlers. XMLRPC Handler, GenericHttpHandler and <Various>StreamHandler
* Applied the XmlRpcBasicDOSProtector.cs to the login service as both an example, and good practice.
* Applied the BaseStreamHandlerBasicDOSProtector.cs to the friends service as an example of the DOS Protector on StreamHandlers
* Added CircularBuffer, used for CPU and Memory friendly rate monitoring.
* DosProtector has 2 states, 1. Just Check for blocked users and check general velocity, 2. Track velocity per user, It only jumps to 2 if it's getting a lot of requests, and state 1 is about as resource friendly as if it wasn't even there.
Diffstat (limited to 'OpenSim/Framework/Servers/HttpServer/XmlRpcBasicDOSProtector.cs')
-rw-r--r-- | OpenSim/Framework/Servers/HttpServer/XmlRpcBasicDOSProtector.cs | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/OpenSim/Framework/Servers/HttpServer/XmlRpcBasicDOSProtector.cs b/OpenSim/Framework/Servers/HttpServer/XmlRpcBasicDOSProtector.cs new file mode 100644 index 0000000..ae59c95 --- /dev/null +++ b/OpenSim/Framework/Servers/HttpServer/XmlRpcBasicDOSProtector.cs | |||
@@ -0,0 +1,211 @@ | |||
1 | /* | ||
2 | * Copyright (c) Contributors, http://opensimulator.org/ | ||
3 | * See CONTRIBUTORS.TXT for a full list of copyright holders. | ||
4 | * | ||
5 | * Redistribution and use in source and binary forms, with or without | ||
6 | * modification, are permitted provided that the following conditions are met: | ||
7 | * * Redistributions of source code must retain the above copyright | ||
8 | * notice, this list of conditions and the following disclaimer. | ||
9 | * * Redistributions in binary form must reproduce the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer in the | ||
11 | * documentation and/or other materials provided with the distribution. | ||
12 | * * Neither the name of the OpenSimulator Project nor the | ||
13 | * names of its contributors may be used to endorse or promote products | ||
14 | * derived from this software without specific prior written permission. | ||
15 | * | ||
16 | * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY | ||
17 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | ||
18 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | ||
19 | * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY | ||
20 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | ||
21 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | ||
22 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | ||
23 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | ||
24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | ||
25 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
26 | */ | ||
27 | |||
28 | using System; | ||
29 | using System.Collections.Generic; | ||
30 | using System.Reflection; | ||
31 | using System.Net; | ||
32 | using Nwc.XmlRpc; | ||
33 | using OpenSim.Framework; | ||
34 | using log4net; | ||
35 | |||
36 | namespace OpenSim.Framework.Servers.HttpServer | ||
37 | { | ||
38 | public enum ThrottleAction | ||
39 | { | ||
40 | DoThrottledMethod, | ||
41 | DoThrow | ||
42 | } | ||
43 | |||
44 | public class XmlRpcBasicDOSProtector | ||
45 | { | ||
46 | private readonly XmlRpcMethod _normalMethod; | ||
47 | private readonly XmlRpcMethod _throttledMethod; | ||
48 | private readonly CircularBuffer<int> _generalRequestTimes; // General request checker | ||
49 | private readonly BasicDosProtectorOptions _options; | ||
50 | private readonly Dictionary<string, CircularBuffer<int>> _deeperInspection; // per client request checker | ||
51 | private readonly Dictionary<string, int> _tempBlocked; // blocked list | ||
52 | private readonly System.Timers.Timer _forgetTimer; // Cleanup timer | ||
53 | private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); | ||
54 | private readonly System.Threading.ReaderWriterLockSlim _lockSlim = new System.Threading.ReaderWriterLockSlim(); | ||
55 | |||
56 | public XmlRpcBasicDOSProtector(XmlRpcMethod normalMethod, XmlRpcMethod throttledMethod,BasicDosProtectorOptions options) | ||
57 | { | ||
58 | _normalMethod = normalMethod; | ||
59 | _throttledMethod = throttledMethod; | ||
60 | _generalRequestTimes = new CircularBuffer<int>(options.MaxRequestsInTimeframe + 1,true); | ||
61 | _generalRequestTimes.Put(0); | ||
62 | _options = options; | ||
63 | _deeperInspection = new Dictionary<string, CircularBuffer<int>>(); | ||
64 | _tempBlocked = new Dictionary<string, int>(); | ||
65 | _forgetTimer = new System.Timers.Timer(); | ||
66 | _forgetTimer.Elapsed += delegate | ||
67 | { | ||
68 | _forgetTimer.Enabled = false; | ||
69 | |||
70 | List<string> removes = new List<string>(); | ||
71 | _lockSlim.EnterReadLock(); | ||
72 | foreach (string str in _tempBlocked.Keys) | ||
73 | { | ||
74 | if ( | ||
75 | Util.EnvironmentTickCountSubtract(Util.EnvironmentTickCount(), | ||
76 | _tempBlocked[str]) > 0) | ||
77 | removes.Add(str); | ||
78 | } | ||
79 | _lockSlim.ExitReadLock(); | ||
80 | lock (_deeperInspection) | ||
81 | { | ||
82 | _lockSlim.EnterWriteLock(); | ||
83 | for (int i = 0; i < removes.Count; i++) | ||
84 | { | ||
85 | _tempBlocked.Remove(removes[i]); | ||
86 | _deeperInspection.Remove(removes[i]); | ||
87 | } | ||
88 | _lockSlim.ExitWriteLock(); | ||
89 | } | ||
90 | foreach (string str in removes) | ||
91 | { | ||
92 | m_log.InfoFormat("[{0}] client: {1} is no longer blocked.", | ||
93 | _options.ReportingName, str); | ||
94 | } | ||
95 | _lockSlim.EnterReadLock(); | ||
96 | if (_tempBlocked.Count > 0) | ||
97 | _forgetTimer.Enabled = true; | ||
98 | _lockSlim.ExitReadLock(); | ||
99 | }; | ||
100 | |||
101 | _forgetTimer.Interval = _options.ForgetTimeSpan.TotalMilliseconds; | ||
102 | } | ||
103 | public XmlRpcResponse Process(XmlRpcRequest request, IPEndPoint client) | ||
104 | { | ||
105 | // If these are set like this, this is disabled | ||
106 | if (_options.MaxRequestsInTimeframe < 1 || _options.RequestTimeSpan.TotalMilliseconds < 1) | ||
107 | return _normalMethod(request, client); | ||
108 | |||
109 | string clientstring = GetClientString(request, client); | ||
110 | |||
111 | _lockSlim.EnterReadLock(); | ||
112 | if (_tempBlocked.ContainsKey(clientstring)) | ||
113 | { | ||
114 | _lockSlim.ExitReadLock(); | ||
115 | |||
116 | if (_options.ThrottledAction == ThrottleAction.DoThrottledMethod) | ||
117 | return _throttledMethod(request, client); | ||
118 | else | ||
119 | throw new System.Security.SecurityException("Throttled"); | ||
120 | } | ||
121 | _lockSlim.ExitReadLock(); | ||
122 | |||
123 | _generalRequestTimes.Put(Util.EnvironmentTickCount()); | ||
124 | |||
125 | if (_generalRequestTimes.Size == _generalRequestTimes.Capacity && | ||
126 | (Util.EnvironmentTickCountSubtract(Util.EnvironmentTickCount(), _generalRequestTimes.Get()) < | ||
127 | _options.RequestTimeSpan.TotalMilliseconds)) | ||
128 | { | ||
129 | //Trigger deeper inspection | ||
130 | if (DeeperInspection(request, client)) | ||
131 | return _normalMethod(request, client); | ||
132 | if (_options.ThrottledAction == ThrottleAction.DoThrottledMethod) | ||
133 | return _throttledMethod(request, client); | ||
134 | else | ||
135 | throw new System.Security.SecurityException("Throttled"); | ||
136 | } | ||
137 | XmlRpcResponse resp = null; | ||
138 | |||
139 | resp = _normalMethod(request, client); | ||
140 | |||
141 | return resp; | ||
142 | } | ||
143 | |||
144 | // If the service is getting more hits per expected timeframe then it starts to separate them out by client | ||
145 | private bool DeeperInspection(XmlRpcRequest request, IPEndPoint client) | ||
146 | { | ||
147 | lock (_deeperInspection) | ||
148 | { | ||
149 | string clientstring = GetClientString(request, client); | ||
150 | |||
151 | |||
152 | if (_deeperInspection.ContainsKey(clientstring)) | ||
153 | { | ||
154 | _deeperInspection[clientstring].Put(Util.EnvironmentTickCount()); | ||
155 | if (_deeperInspection[clientstring].Size == _deeperInspection[clientstring].Capacity && | ||
156 | (Util.EnvironmentTickCountSubtract(Util.EnvironmentTickCount(), _deeperInspection[clientstring].Get()) < | ||
157 | _options.RequestTimeSpan.TotalMilliseconds)) | ||
158 | { | ||
159 | //Looks like we're over the limit | ||
160 | _lockSlim.EnterWriteLock(); | ||
161 | if (!_tempBlocked.ContainsKey(clientstring)) | ||
162 | _tempBlocked.Add(clientstring, Util.EnvironmentTickCount() + (int)_options.ForgetTimeSpan.TotalMilliseconds); | ||
163 | else | ||
164 | _tempBlocked[clientstring] = Util.EnvironmentTickCount() + (int)_options.ForgetTimeSpan.TotalMilliseconds; | ||
165 | _lockSlim.ExitWriteLock(); | ||
166 | |||
167 | m_log.WarnFormat("[{0}]: client: {1} is blocked for {2} milliseconds, X-ForwardedForAllowed status is {3}, endpoint:{4}",_options.ReportingName,clientstring,_options.ForgetTimeSpan.TotalMilliseconds, _options.AllowXForwardedFor, client.Address); | ||
168 | |||
169 | return false; | ||
170 | } | ||
171 | //else | ||
172 | // return true; | ||
173 | } | ||
174 | else | ||
175 | { | ||
176 | _deeperInspection.Add(clientstring, new CircularBuffer<int>(_options.MaxRequestsInTimeframe + 1, true)); | ||
177 | _deeperInspection[clientstring].Put(Util.EnvironmentTickCount()); | ||
178 | _forgetTimer.Enabled = true; | ||
179 | } | ||
180 | |||
181 | } | ||
182 | return true; | ||
183 | } | ||
184 | private string GetClientString(XmlRpcRequest request, IPEndPoint client) | ||
185 | { | ||
186 | string clientstring; | ||
187 | if (_options.AllowXForwardedFor && request.Params.Count > 3) | ||
188 | { | ||
189 | object headerstr = request.Params[3]; | ||
190 | if (headerstr != null && !string.IsNullOrEmpty(headerstr.ToString())) | ||
191 | clientstring = request.Params[3].ToString(); | ||
192 | else | ||
193 | clientstring = client.Address.ToString(); | ||
194 | } | ||
195 | else | ||
196 | clientstring = client.Address.ToString(); | ||
197 | return clientstring; | ||
198 | } | ||
199 | |||
200 | } | ||
201 | |||
202 | public class BasicDosProtectorOptions | ||
203 | { | ||
204 | public int MaxRequestsInTimeframe; | ||
205 | public TimeSpan RequestTimeSpan; | ||
206 | public TimeSpan ForgetTimeSpan; | ||
207 | public bool AllowXForwardedFor; | ||
208 | public string ReportingName = "BASICDOSPROTECTOR"; | ||
209 | public ThrottleAction ThrottledAction = ThrottleAction.DoThrottledMethod; | ||
210 | } | ||
211 | } | ||