1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the OpenSimulator Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using System;
using System.Collections.Generic;
using System.Net.Sockets;
using System.Net;
using System.Net.NetworkInformation;
using System.Reflection;
using log4net;
namespace OpenSim.Framework
{
/// <summary>
/// Handles NAT translation in a 'manner of speaking'
/// Allows you to return multiple different external
/// hostnames depending on the requestors network
///
/// This enables standard port forwarding techniques
/// to work correctly with OpenSim.
/// </summary>
public static class NetworkUtil
{
// Logger
private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
private static bool m_disabled = true;
public static bool Enabled
{
set { m_disabled = value; }
get { return m_disabled; }
}
// IPv4Address, Subnet
static readonly Dictionary<IPAddress,IPAddress> m_subnets = new Dictionary<IPAddress, IPAddress>();
public static IPAddress GetIPFor(IPAddress user, IPAddress simulator)
{
if (m_disabled)
return simulator;
// Check if we're accessing localhost.
foreach (IPAddress host in Dns.GetHostAddresses(Dns.GetHostName()))
{
if (host.Equals(user) && host.AddressFamily == AddressFamily.InterNetwork)
{
m_log.Info("[NetworkUtil] Localhost user detected, sending them '" + host + "' instead of '" + simulator + "'");
return host;
}
}
// Check for same LAN segment
foreach (KeyValuePair<IPAddress, IPAddress> subnet in m_subnets)
{
byte[] subnetBytes = subnet.Value.GetAddressBytes();
byte[] localBytes = subnet.Key.GetAddressBytes();
byte[] destBytes = user.GetAddressBytes();
if (subnetBytes.Length != destBytes.Length || subnetBytes.Length != localBytes.Length)
return null;
bool valid = true;
for (int i = 0; i < subnetBytes.Length; i++)
{
if ((localBytes[i] & subnetBytes[i]) != (destBytes[i] & subnetBytes[i]))
{
valid = false;
break;
}
}
if (subnet.Key.AddressFamily != AddressFamily.InterNetwork)
valid = false;
if (valid)
{
m_log.Info("[NetworkUtil] Local LAN user detected, sending them '" + subnet.Key + "' instead of '" + simulator + "'");
return subnet.Key;
}
}
// Otherwise, return outside address
return simulator;
}
private static IPAddress GetExternalIPFor(IPAddress destination, string defaultHostname)
{
// Adds IPv6 Support (Not that any of the major protocols supports it...)
if (destination.AddressFamily == AddressFamily.InterNetworkV6)
{
foreach (IPAddress host in Dns.GetHostAddresses(defaultHostname))
{
if (host.AddressFamily == AddressFamily.InterNetworkV6)
{
m_log.Info("[NetworkUtil] Localhost user detected, sending them '" + host + "' instead of '" + defaultHostname + "'");
return host;
}
}
}
if (destination.AddressFamily != AddressFamily.InterNetwork)
return null;
// Check if we're accessing localhost.
foreach (KeyValuePair<IPAddress, IPAddress> pair in m_subnets)
{
IPAddress host = pair.Value;
if (host.Equals(destination) && host.AddressFamily == AddressFamily.InterNetwork)
{
m_log.Info("[NATROUTING] Localhost user detected, sending them '" + host + "' instead of '" + defaultHostname + "'");
return destination;
}
}
// Check for same LAN segment
foreach (KeyValuePair<IPAddress, IPAddress> subnet in m_subnets)
{
byte[] subnetBytes = subnet.Value.GetAddressBytes();
byte[] localBytes = subnet.Key.GetAddressBytes();
byte[] destBytes = destination.GetAddressBytes();
if (subnetBytes.Length != destBytes.Length || subnetBytes.Length != localBytes.Length)
return null;
bool valid = true;
for (int i=0;i<subnetBytes.Length;i++)
{
if ((localBytes[i] & subnetBytes[i]) != (destBytes[i] & subnetBytes[i]))
{
valid = false;
break;
}
}
if (subnet.Key.AddressFamily != AddressFamily.InterNetwork)
valid = false;
if (valid)
{
m_log.Info("[NetworkUtil] Local LAN user detected, sending them '" + subnet.Key + "' instead of '" + defaultHostname + "'");
return subnet.Key;
}
}
// Check to see if we can find a IPv4 address.
foreach (IPAddress host in Dns.GetHostAddresses(defaultHostname))
{
if (host.AddressFamily == AddressFamily.InterNetwork)
return host;
}
// Unable to find anything.
throw new ArgumentException("[NetworkUtil] Unable to resolve defaultHostname to an IPv4 address for an IPv4 client");
}
static NetworkUtil()
{
try
{
foreach (NetworkInterface ni in NetworkInterface.GetAllNetworkInterfaces())
{
foreach (UnicastIPAddressInformation address in ni.GetIPProperties().UnicastAddresses)
{
if (address.Address.AddressFamily == AddressFamily.InterNetwork)
{
if (address.IPv4Mask != null)
{
m_subnets.Add(address.Address, address.IPv4Mask);
}
}
}
}
}
catch (NotImplementedException)
{
// Mono Sucks.
}
}
public static IPAddress GetIPFor(IPEndPoint user, string defaultHostname)
{
if (!m_disabled)
{
// Try subnet matching
IPAddress rtn = GetExternalIPFor(user.Address, defaultHostname);
if (rtn != null)
return rtn;
}
// Otherwise use the old algorithm
IPAddress ia;
if (IPAddress.TryParse(defaultHostname, out ia))
return ia;
ia = null;
foreach (IPAddress Adr in Dns.GetHostAddresses(defaultHostname))
{
if (Adr.AddressFamily == AddressFamily.InterNetwork)
{
ia = Adr;
break;
}
}
return ia;
}
public static string GetHostFor(IPAddress user, string defaultHostname)
{
if (!m_disabled)
{
IPAddress rtn = GetExternalIPFor(user, defaultHostname);
if (rtn != null)
return rtn.ToString();
}
return defaultHostname;
}
}
}
|
