/* * 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; } } }