Files
libremetaverse/SLProxy/SLProxy.cs

1165 lines
44 KiB
C#

/*
* SLProxy.cs: implementation of Second Life proxy library
*
* Copyright (c) 2006 Austin Jennings
* All rights reserved.
*
* - 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.
* - Neither the name of the Second Life Reverse Engineering Team 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 COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR 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.
*/
//#define DEBUG_SEQUENCE
using Nwc.XmlRpc;
using System;
using System.Collections;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Xml;
using libsecondlife;
// SLProxy: proxy library for Second Life
namespace SLProxy {
// ProxyConfig: configuration for proxy objects
public class ProxyConfig {
// userAgent: name of the proxy application
public string userAgent;
// author: email address of the proxy application's author
public string author;
// protocol: libsecondlife ProtocolManager
public ProtocolManager protocol;
// loginPort: port that the login proxy will listen on
public ushort loginPort = 8080;
// clientFacingAddress: address from which to communicate with the client
public IPAddress clientFacingAddress = IPAddress.Loopback;
// remoteFacingAddress: address from which to communicate with the server
public IPAddress remoteFacingAddress = IPAddress.Any;
// remoteLoginUri: URI for Second Life's login server
public Uri remoteLoginUri = new Uri("https://login.agni.lindenlab.com/cgi-bin/login.cgi");
// verbose: whether or not to print informative messages
public bool verbose = true;
// ProxyConfig: construct a default proxy configuration with the specified userAgent, author, and protocol
public ProxyConfig(string userAgent, string author, ProtocolManager protocol) {
this.userAgent = userAgent;
this.author = author;
this.protocol = protocol;
}
// ProxyConfig: construct a default proxy configuration, parsing command line arguments (try --proxy-help)
public ProxyConfig(string userAgent, string author, ProtocolManager protocol, string[] args) : this(userAgent, author, protocol) {
Hashtable argumentParsers = new Hashtable();
argumentParsers["proxy-help"] = new ArgumentParser(ParseHelp);
argumentParsers["proxy-login-port"] = new ArgumentParser(ParseLoginPort);
argumentParsers["proxy-client-facing-address"] = new ArgumentParser(ParseClientFacingAddress);
argumentParsers["proxy-remote-facing-address"] = new ArgumentParser(ParseRemoteFacingAddress);
argumentParsers["proxy-remote-login-uri"] = new ArgumentParser(ParseRemoteLoginUri);
argumentParsers["proxy-verbose"] = new ArgumentParser(ParseVerbose);
argumentParsers["proxy-quiet"] = new ArgumentParser(ParseQuiet);
foreach (string arg in args)
foreach (string argument in argumentParsers.Keys) {
Match match = (new Regex("^--" + argument + "(?:=(.*))?$")).Match(arg);
if (match.Success) {
string value;
if (match.Groups[1].Captures.Count == 1)
value = match.Groups[1].Captures[0].ToString();
else
value = null;
try {
((ArgumentParser)argumentParsers[argument])(value);
} catch {
Console.WriteLine("invalid value for --" + argument);
ParseHelp(null);
}
}
}
}
private delegate void ArgumentParser(string value);
private void ParseHelp(string value) {
Console.WriteLine("Proxy command-line arguments:" );
Console.WriteLine(" --proxy-help display this help" );
Console.WriteLine(" --proxy-login-port=<port> listen for logins on <port>" );
Console.WriteLine(" --proxy-client-facing-address=<IP> communicate with client via <IP>" );
Console.WriteLine(" --proxy-remote-facing-address=<IP> communicate with server via <IP>" );
Console.WriteLine(" --proxy-remote-login-uri=<URI> use SL login server at <URI>" );
Console.WriteLine(" --proxy-verbose display proxy notifications" );
Console.WriteLine(" --proxy-quiet suppress proxy notifications" );
Environment.Exit(1);
}
private void ParseLoginPort(string value) {
loginPort = Convert.ToUInt16(value);
}
private void ParseClientFacingAddress(string value) {
clientFacingAddress = IPAddress.Parse(value);
}
private void ParseRemoteFacingAddress(string value) {
remoteFacingAddress = IPAddress.Parse(value);
}
private void ParseRemoteLoginUri(string value) {
remoteLoginUri = new Uri(value);
}
private void ParseVerbose(string value) {
if (value != null)
throw new Exception();
verbose = true;
}
private void ParseQuiet(string value) {
if (value != null)
throw new Exception();
verbose = false;
}
}
// Proxy: Second Life proxy server
// A Proxy instance is only prepared to deal with one client at a time.
public class Proxy {
private ProxyConfig proxyConfig;
/*
* Proxy Management
*/
// Proxy: construct a proxy server with the given configuration
public Proxy(ProxyConfig proxyConfig) {
this.proxyConfig = proxyConfig;
InitializeLoginProxy();
InitializeSimProxy();
}
object keepAliveLock = new Object();
// Start: begin accepting clients
public void Start() { lock(this) {
System.Threading.Monitor.Enter(keepAliveLock);
(new Thread(new ThreadStart(KeepAlive))).Start();
RunSimProxy();
Thread runLoginProxy = new Thread(new ThreadStart(RunLoginProxy));
runLoginProxy.IsBackground = true;
runLoginProxy.Start();
IPEndPoint endPoint = (IPEndPoint)loginServer.LocalEndPoint;
IPAddress displayAddress;
if (endPoint.Address == IPAddress.Any)
displayAddress = IPAddress.Loopback;
else
displayAddress = endPoint.Address;
Log("proxy ready at http://" + displayAddress + ":" + endPoint.Port + "/", false);
}}
// Stop: allow foreground threads to die
public void Stop() { lock(this) {
System.Threading.Monitor.Exit(keepAliveLock);
}}
// KeepAlive: blocks until the proxy is free to shut down
public void KeepAlive() {
lock(keepAliveLock);
}
// SetLoginRequestDelegate: specify a callback loginRequestDelegate that will be called when the client requests login
public void SetLoginRequestDelegate(XmlRpcRequestDelegate loginRequestDelegate) { lock(this) {
this.loginRequestDelegate = loginRequestDelegate;
}}
// SetLoginResponseDelegate: specify a callback loginResponseDelegate that will be called when the server responds to login
public void SetLoginResponseDelegate(XmlRpcResponseDelegate loginResponseDelegate) { lock(this) {
this.loginResponseDelegate = loginResponseDelegate;
}}
// AddDelegate: add callback packetDelegate for packets of type packetName going direction
public void AddDelegate(string packetName, Direction direction, PacketDelegate packetDelegate) { lock(this) {
(direction == Direction.Incoming ? incomingDelegates : outgoingDelegates)[packetName] = packetDelegate;
}}
// RemoveDelegate: remove callback for packets of type packetName going direction
public void RemoveDelegate(string packetName, Direction direction) { lock(this) {
(direction == Direction.Incoming ? incomingDelegates : outgoingDelegates).Remove(packetName);
}}
// InjectPacket: send packet to the client or server when direction is Incoming or Outgoing, respectively
public void InjectPacket(Packet packet, Direction direction) { lock(this) {
if (activeCircuit == null) {
// no active circuit; queue the packet for injection once we have one
ArrayList queue = direction == Direction.Incoming ? queuedIncomingInjections : queuedOutgoingInjections;
queue.Add(packet);
} else
// tell the active sim proxy to inject the packet
((SimProxy)simProxies[activeCircuit]).Inject(packet, direction);
}}
// Log: write message to the console if in verbose mode
private void Log(object message, bool important) {
if (proxyConfig.verbose || important)
Console.WriteLine(message);
}
/*
* Login Proxy
*/
private Socket loginServer;
// InitializeLoginProxy: initialize the login proxy
private void InitializeLoginProxy() {
loginServer = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
loginServer.Bind(new IPEndPoint(proxyConfig.clientFacingAddress, proxyConfig.loginPort));
loginServer.Listen(1);
}
// RunLoginProxy: process login requests from clients
private void RunLoginProxy() {
try {
for (;;) {
Socket client = loginServer.Accept();
IPEndPoint clientEndPoint = (IPEndPoint)client.RemoteEndPoint;
Log("handling login request from " + clientEndPoint, false);
NetworkStream networkStream = new NetworkStream(client);
StreamReader networkReader = new StreamReader(networkStream);
StreamWriter networkWriter = new StreamWriter(networkStream);
try {
ProxyLogin(networkReader, networkWriter);
} catch (Exception e) {
Log("login failed: " + e.Message, false);
}
networkWriter.Close();
networkReader.Close();
networkStream.Close();
client.Close();
// send any packets queued for injection
if (activeCircuit != null) lock(this) {
SimProxy activeProxy = (SimProxy)simProxies[activeCircuit];
foreach (Packet packet in queuedOutgoingInjections)
activeProxy.Inject(packet, Direction.Outgoing);
queuedOutgoingInjections = new ArrayList();
}
}
} catch (Exception e) {
Console.WriteLine(e.Message);
Console.WriteLine(e.StackTrace);
}
}
// ProxyLogin: proxy a login request
private void ProxyLogin(StreamReader reader, StreamWriter writer) { lock(this) {
string line;
int contentLength = 0;
// read HTTP header
do {
// read one line of the header
line = reader.ReadLine();
// check for premature EOF
if (line == null)
throw new Exception("EOF in client HTTP header");
// look for Content-Length
Match match = (new Regex(@"Content-Length: (\d+)$")).Match(line);
if (match.Success)
contentLength = Convert.ToInt32(match.Groups[1].Captures[0].ToString());
} while (line != "");
// read the HTTP body into a buffer
char[] content = new char[contentLength];
reader.Read(content, 0, contentLength);
// convert the body into an XML-RPC request
XmlRpcRequest request = (XmlRpcRequest)(new XmlRpcRequestDeserializer()).Deserialize(new String(content));
// call the loginRequestDelegate
if (loginRequestDelegate != null)
try {
loginRequestDelegate(request);
} catch (Exception e) {
Log("exception in login request deligate: " + e.Message, true);
Log(e.StackTrace, true);
}
// add our userAgent and author to the request
Hashtable requestParams = new Hashtable();
if (proxyConfig.userAgent != null)
requestParams["user-agent"] = proxyConfig.userAgent;
if (proxyConfig.author != null)
requestParams["author"] = proxyConfig.author;
request.Params.Add(requestParams);
// forward the XML-RPC request to the server
XmlRpcResponse response = (XmlRpcResponse)request.Send(proxyConfig.remoteLoginUri.ToString());
Hashtable responseData = (Hashtable)response.Value;
// proxy any simulator address given in the XML-RPC response
if (responseData.Contains("sim_ip") && responseData.Contains("sim_port")) {
IPEndPoint realSim = new IPEndPoint(IPAddress.Parse((string)responseData["sim_ip"]), Convert.ToUInt16(responseData["sim_port"]));
IPEndPoint fakeSim = ProxySim(realSim);
responseData["sim_ip"] = fakeSim.Address.ToString();
responseData["sim_port"] = fakeSim.Port;
activeCircuit = realSim;
}
// start a new proxy session
Reset();
// call the loginResponseDelegate
if (loginResponseDelegate != null) {
try {
loginResponseDelegate(response);
} catch (Exception e) {
Log("exception in login response delegate: " + e.Message, true);
Log(e.StackTrace, true);
}
}
// forward the XML-RPC response to the client
writer.WriteLine("HTTP/1.0 200 OK");
writer.WriteLine("Content-type: text/xml");
writer.WriteLine();
XmlTextWriter responseWriter = new XmlTextWriter(writer);
XmlRpcResponseSerializer.Singleton.Serialize(responseWriter, response);
responseWriter.Close();
}}
/*
* Sim Proxy
*/
private Socket simFacingSocket;
private IPEndPoint activeCircuit = null;
private Hashtable proxyEndPoints = new Hashtable();
private Hashtable simProxies = new Hashtable();
private Hashtable proxyHandlers = new Hashtable();
private XmlRpcRequestDelegate loginRequestDelegate = null;
private XmlRpcResponseDelegate loginResponseDelegate = null;
private Hashtable incomingDelegates = new Hashtable();
private Hashtable outgoingDelegates = new Hashtable();
private ArrayList queuedIncomingInjections = new ArrayList();
private ArrayList queuedOutgoingInjections = new ArrayList();
// InitializeSimProxy: initialize the sim proxy
private void InitializeSimProxy() {
InitializeAddressCheckers();
simFacingSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
simFacingSocket.Bind(new IPEndPoint(proxyConfig.remoteFacingAddress, 0));
Reset();
}
// Reset: start a new session
private void Reset() {
foreach (SimProxy simProxy in simProxies.Values)
simProxy.Reset();
}
private byte[] receiveBuffer = new byte[8192];
private byte[] zeroBuffer = new byte[8192];
private EndPoint remoteEndPoint = (EndPoint)new IPEndPoint(IPAddress.Any, 0);
// RunSimProxy: start listening for packets from remote sims
private void RunSimProxy() {
simFacingSocket.BeginReceiveFrom(receiveBuffer, 0, receiveBuffer.Length, SocketFlags.None, ref remoteEndPoint, new AsyncCallback(ReceiveFromSim), null);
}
// ReceiveFromSim: packet received from a remote sim
private void ReceiveFromSim(IAsyncResult ar) { lock(this) try {
// pause listening and fetch the packet
bool needsZero = false;
bool needsCopy = true;
int length;
length = simFacingSocket.EndReceiveFrom(ar, ref remoteEndPoint);
if (proxyHandlers.Contains(remoteEndPoint)) {
// find the proxy responsible for forwarding this packet
SimProxy simProxy = (SimProxy)proxyHandlers[remoteEndPoint];
// interpret the packet according to the SL protocol
Packet packet;
if ((receiveBuffer[0] & Helpers.MSG_ZEROCODED) == 0)
packet = new Packet(receiveBuffer, length, proxyConfig.protocol, proxyConfig.protocol.Command(receiveBuffer), false);
else {
Helpers.ZeroDecodeCommand(receiveBuffer, zeroBuffer);
packet = new Packet(receiveBuffer, length, proxyConfig.protocol, proxyConfig.protocol.Command(zeroBuffer), false);
needsZero = true;
}
#if DEBUG_SEQUENCE
Console.WriteLine("<- " + packet.Layout.Name + " #" + packet.Sequence);
#endif
// check for ACKs we're waiting for
packet = simProxy.CheckAcks(packet, Direction.Incoming, ref length, ref needsCopy);
// modify sequence numbers to account for injections
ushort oldSequence = packet.Sequence;
packet = simProxy.ModifySequence(packet, Direction.Incoming, ref length, ref needsCopy);
// keep track of sequence numbers
if (packet.Sequence > simProxy.incomingSequence)
simProxy.incomingSequence = packet.Sequence;
// check the packet for addresses that need proxying
if (incomingCheckers.Contains(packet.Layout.Name)) {
if (needsZero) {
length = Helpers.ZeroDecode(packet.Data, length, zeroBuffer);
packet.Data = zeroBuffer;
needsZero = false;
}
Packet newPacket = ((AddressChecker)incomingCheckers[packet.Layout.Name])(packet);
SwapPacket(packet, newPacket, length);
packet = newPacket;
length = packet.Data.Length;
needsCopy = false;
}
// pass the packet to any callback delegates
if (incomingDelegates.Contains(packet.Layout.Name)) {
if (needsZero) {
length = Helpers.ZeroDecode(packet.Data, length, zeroBuffer);
packet.Data = zeroBuffer;
needsCopy = true;
}
if (needsCopy) {
byte[] newData = new byte[length];
Array.Copy(packet.Data, 0, newData, 0, length);
packet.Data = newData;
}
try {
Packet newPacket = ((PacketDelegate)incomingDelegates[packet.Layout.Name])(packet, (IPEndPoint)remoteEndPoint);
if (newPacket == null) {
if ((packet.Data[0] & Helpers.MSG_RELIABLE) != 0)
simProxy.Inject(SpoofAck(oldSequence), Direction.Outgoing);
if ((packet.Data[0] & Helpers.MSG_APPENDED_ACKS) != 0)
packet = SeparateAck(packet);
else
packet = null;
} else {
bool oldReliable = (packet.Data[0] & Helpers.MSG_RELIABLE) != 0;
bool newReliable = (newPacket.Data[0] & Helpers.MSG_RELIABLE) != 0;
if (oldReliable && !newReliable)
simProxy.Inject(SpoofAck(oldSequence), Direction.Outgoing);
else if (!oldReliable && newReliable)
simProxy.WaitForAck(packet, Direction.Incoming);
SwapPacket(packet, newPacket, packet.Data.Length);
packet = newPacket;
}
} catch (Exception e) {
Log("exception in incoming delegate: " + e.Message, true);
Log(e.StackTrace, true);
}
if (packet != null)
simProxy.SendPacket(packet, packet.Data.Length, false);
} else
simProxy.SendPacket(packet, length, needsZero);
} else
// ignore packets from unknown peers
Log("dropping packet from " + remoteEndPoint, false);
} catch (Exception e) {
Console.WriteLine(e.Message);
Console.WriteLine(e.StackTrace);
} finally {
// resume listening
simFacingSocket.BeginReceiveFrom(receiveBuffer, 0, receiveBuffer.Length, SocketFlags.None, ref remoteEndPoint, new AsyncCallback(ReceiveFromSim), null);
}}
// SendPacket: send a packet to a sim from our fake client endpoint
public void SendPacket(Packet packet, IPEndPoint endPoint, int length, bool skipZero) {
if (skipZero || (packet.Data[0] & Helpers.MSG_ZEROCODED) == 0)
simFacingSocket.SendTo(packet.Data, length, SocketFlags.None, endPoint);
else {
int zeroLength = Helpers.ZeroEncode(packet.Data, length, zeroBuffer);
simFacingSocket.SendTo(zeroBuffer, zeroLength, SocketFlags.None, endPoint);
}
}
// SpoofAck: create an ACK for the given packet
public Packet SpoofAck(ushort sequence) {
Hashtable blocks = new Hashtable();
Hashtable fields = new Hashtable();
fields["ID"] = (uint)sequence;
blocks[fields] = "Packets";
return PacketBuilder.BuildPacket("PacketAck", proxyConfig.protocol, blocks, Helpers.MSG_ZEROCODED);
}
// SeparateAck: create a standalone PacketAck for packet's appended ACKs
public Packet SeparateAck(Packet packet) {
int ackCount = ((packet.Data[0] & Helpers.MSG_APPENDED_ACKS) == 0 ? 0 : (int)packet.Data[packet.Data.Length - 1]);
Hashtable blocks = new Hashtable();
for (int i = 0; i < ackCount; ++i) {
Hashtable fields = new Hashtable();
int offset = packet.Data.Length - (ackCount - i) * 4 - 1;
fields["ID"] = (uint)
(packet.Data[offset++] << 0)
+ (packet.Data[offset++] << 8)
+ (packet.Data[offset++] << 16)
+ (packet.Data[offset++] << 24)
;
blocks[fields] = "Packets";
}
Packet ack = PacketBuilder.BuildPacket("PacketAck", proxyConfig.protocol, blocks, Helpers.MSG_ZEROCODED);
ack.Sequence = packet.Sequence;
return ack;
}
// SwapPacket: copy the sequence number and appended ACKs from one packet to another
public static void SwapPacket(Packet oldPacket, Packet newPacket, int oldLength) {
newPacket.Sequence = oldPacket.Sequence;
int oldAcks = (oldPacket.Data[0] & Helpers.MSG_APPENDED_ACKS) == 0 ? 0 : (int)oldPacket.Data[oldLength - 1];
int newAcks = (newPacket.Data[0] & Helpers.MSG_APPENDED_ACKS) == 0 ? 0 : (int)newPacket.Data[newPacket.Data.Length - 1];
if (oldAcks != 0 || newAcks != 0) {
int oldAckSize = oldAcks == 0 ? 0 : oldAcks * 4 + 1;
int newAckSize = newAcks == 0 ? 0 : newAcks * 4 + 1;
byte[] newData = new byte[newPacket.Data.Length - newAckSize + oldAckSize];
Array.Copy(newPacket.Data, 0, newData, 0, newPacket.Data.Length - newAckSize);
if (newAcks != 0)
newData[0] ^= Helpers.MSG_APPENDED_ACKS;
if (oldAcks != 0) {
newData[0] |= Helpers.MSG_APPENDED_ACKS;
Array.Copy(oldPacket.Data, oldLength - oldAckSize, newData, newPacket.Data.Length - newAckSize, oldAckSize);
}
newPacket.Data = newData;
}
}
// ProxySim: return the proxy for the specified sim, creating it if it doesn't exist
private IPEndPoint ProxySim(IPEndPoint simEndPoint) {
if (proxyEndPoints.Contains(simEndPoint))
// return the existing proxy
return (IPEndPoint)proxyEndPoints[simEndPoint];
else {
// return a new proxy
SimProxy simProxy = new SimProxy(proxyConfig, simEndPoint, this);
IPEndPoint fakeSim = simProxy.LocalEndPoint();
Log("creating proxy for " + simEndPoint + " at " + fakeSim, false);
simProxy.Run();
proxyEndPoints.Add(simEndPoint, fakeSim);
simProxies.Add(simEndPoint, simProxy);
return fakeSim;
}
}
// AddHandler: remember which sim proxy corresponds to a given sim
private void AddHandler(EndPoint endPoint, SimProxy proxy) {
proxyHandlers.Add(endPoint, proxy);
}
// SimProxy: proxy for a single simulator
private class SimProxy {
private ProxyConfig proxyConfig;
private IPEndPoint remoteEndPoint;
private Proxy proxy;
private Socket socket;
public ushort incomingSequence;
public ushort outgoingSequence;
private ArrayList incomingInjections;
private ArrayList outgoingInjections;
private ushort incomingOffset = 0;
private ushort outgoingOffset = 0;
private Hashtable incomingAcks;
private Hashtable outgoingAcks;
private ArrayList incomingSeenAcks;
private ArrayList outgoingSeenAcks;
// SimProxy: construct a proxy for a single simulator
public SimProxy(ProxyConfig proxyConfig, IPEndPoint simEndPoint, Proxy proxy) {
this.proxyConfig = proxyConfig;
remoteEndPoint = new IPEndPoint(simEndPoint.Address, simEndPoint.Port);
this.proxy = proxy;
socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
socket.Bind(new IPEndPoint(proxyConfig.clientFacingAddress, 0));
proxy.AddHandler(remoteEndPoint, this);
Reset();
}
// Reset: start a new session
public void Reset() {
incomingSequence = 0;
outgoingSequence = 0;
incomingInjections = new ArrayList();
outgoingInjections = new ArrayList();
incomingAcks = new Hashtable();
outgoingAcks = new Hashtable();
incomingSeenAcks = new ArrayList();
outgoingSeenAcks = new ArrayList();
}
// BackgroundTasks: resend unacknowledged packets and keep data structures clean
private void BackgroundTasks() { try {
int tick = 1;
int incomingInjectionsPoint = 0;
int outgoingInjectionsPoint = 0;
int incomingSeenAcksPoint = 0;
int outgoingSeenAcksPoint = 0;
for (;; Thread.Sleep(1000)) lock(proxy) {
if ((tick = (tick + 1) % 60) == 0) {
for (int i = 0; i < incomingInjectionsPoint; ++i) {
incomingInjections.RemoveAt(0);
++incomingOffset;
#if DEBUG_SEQUENCE
Console.WriteLine("incomingOffset = " + incomingOffset);
#endif
}
incomingInjectionsPoint = incomingInjections.Count;
for (int i = 0; i < outgoingInjectionsPoint; ++i) {
outgoingInjections.RemoveAt(0);
++outgoingOffset;
#if DEBUG_SEQUENCE
Console.WriteLine("outgoingOffset = " + outgoingOffset);
#endif
}
outgoingInjectionsPoint = outgoingInjections.Count;
for (int i = 0; i < incomingSeenAcksPoint; ++i) {
#if DEBUG_SEQUENCE
Console.WriteLine("incomingAcks.Remove(" + incomingSeenAcks[0] + ")");
#endif
incomingAcks.Remove(incomingSeenAcks[0]);
incomingSeenAcks.RemoveAt(0);
}
incomingSeenAcksPoint = incomingSeenAcks.Count;
for (int i = 0; i < outgoingSeenAcksPoint; ++i) {
#if DEBUG_SEQUENCE
Console.WriteLine("outgoingAcks.Remove(" + outgoingSeenAcks[0] + ")");
#endif
outgoingAcks.Remove(outgoingSeenAcks[0]);
outgoingSeenAcks.RemoveAt(0);
}
outgoingSeenAcksPoint = outgoingSeenAcks.Count;
}
foreach (ushort id in incomingAcks.Keys)
if (!incomingSeenAcks.Contains(id)) {
Packet packet = (Packet)incomingAcks[id];
packet.Data[0] |= Helpers.MSG_RESENT;
#if DEBUG_SEQUENCE
Console.WriteLine("RESEND <- " + packet.Layout.Name + " #" + packet.Sequence);
#endif
SendPacket(packet, packet.Data.Length, false);
}
foreach (ushort id in outgoingAcks.Keys)
if (!outgoingSeenAcks.Contains(id)) {
Packet packet = (Packet)outgoingAcks[id];
packet.Data[0] |= Helpers.MSG_RESENT;
#if DEBUG_SEQUENCE
Console.WriteLine("RESEND -> " + packet.Layout.Name + " #" + packet.Sequence);
#endif
proxy.SendPacket(packet, remoteEndPoint, packet.Data.Length, false);
}
}
} catch (Exception e) {
Console.WriteLine(e.Message);
Console.WriteLine(e.StackTrace);
}}
// LocalEndPoint: return the endpoint that the client should communicate with
public IPEndPoint LocalEndPoint() {
return (IPEndPoint)socket.LocalEndPoint;
}
private byte[] receiveBuffer = new byte[8192];
private byte[] zeroBuffer = new byte[8192];
private EndPoint clientEndPoint = new IPEndPoint(IPAddress.Any, 0);
bool firstReceive = true;
// Run: forward packets from the client to the sim
public void Run() {
Thread backgroundTasks = new Thread(new ThreadStart(BackgroundTasks));
backgroundTasks.IsBackground = true;
backgroundTasks.Start();
socket.BeginReceiveFrom(receiveBuffer, 0, receiveBuffer.Length, SocketFlags.None, ref clientEndPoint, new AsyncCallback(ReceiveFromClient), null);
}
// ReceiveFromClient: packet received from the client
private void ReceiveFromClient(IAsyncResult ar) { lock(proxy) try {
// pause listening and fetch the packet
bool needsZero = false;
bool needsCopy = true;
int length;
length = socket.EndReceiveFrom(ar, ref clientEndPoint);
// interpret the packet according to the SL protocol
Packet packet;
if ((receiveBuffer[0] & Helpers.MSG_ZEROCODED) == 0)
packet = new Packet(receiveBuffer, length, proxyConfig.protocol, proxyConfig.protocol.Command(receiveBuffer), false);
else {
Helpers.ZeroDecodeCommand(receiveBuffer, zeroBuffer);
packet = new Packet(receiveBuffer, length, proxyConfig.protocol, proxyConfig.protocol.Command(zeroBuffer), false);
needsZero = true;
}
#if DEBUG_SEQUENCE
Console.WriteLine("-> " + packet.Layout.Name + " #" + packet.Sequence);
#endif
// check for ACKs we're waiting for
packet = CheckAcks(packet, Direction.Outgoing, ref length, ref needsCopy);
// modify sequence numbers to account for injections
ushort oldSequence = packet.Sequence;
packet = ModifySequence(packet, Direction.Outgoing, ref length, ref needsCopy);
// keep track of sequence numbers
if (packet.Sequence > outgoingSequence)
outgoingSequence = packet.Sequence;
// check the packet for addresses that need proxying
if (proxy.outgoingCheckers.Contains(packet.Layout.Name)) {
if (needsZero) {
length = Helpers.ZeroDecode(packet.Data, length, zeroBuffer);
packet.Data = zeroBuffer;
needsZero = false;
}
Packet newPacket = ((AddressChecker)proxy.outgoingCheckers[packet.Layout.Name])(packet);
SwapPacket(packet, newPacket, length);
packet = newPacket;
length = packet.Data.Length;
needsCopy = false;
}
// pass the packet to any callback delegates
if (proxy.outgoingDelegates.Contains(packet.Layout.Name)) {
if (needsZero) {
length = Helpers.ZeroDecode(packet.Data, length, zeroBuffer);
packet.Data = zeroBuffer;
needsCopy = true;
}
if (needsCopy) {
byte[] newData = new byte[length];
Array.Copy(packet.Data, 0, newData, 0, length);
packet.Data = newData;
}
try {
Packet newPacket = ((PacketDelegate)proxy.outgoingDelegates[packet.Layout.Name])(packet, remoteEndPoint);
if (newPacket == null) {
if ((packet.Data[0] & Helpers.MSG_RELIABLE) != 0)
Inject(proxy.SpoofAck(oldSequence), Direction.Incoming);
if ((packet.Data[0] & Helpers.MSG_APPENDED_ACKS) != 0)
packet = proxy.SeparateAck(packet);
else
packet = null;
} else {
bool oldReliable = (packet.Data[0] & Helpers.MSG_RELIABLE) != 0;
bool newReliable = (newPacket.Data[0] & Helpers.MSG_RELIABLE) != 0;
if (oldReliable && !newReliable)
Inject(proxy.SpoofAck(oldSequence), Direction.Incoming);
else if (!oldReliable && newReliable)
WaitForAck(packet, Direction.Outgoing);
SwapPacket(packet, newPacket, packet.Data.Length);
packet = newPacket;
}
} catch (Exception e) {
proxy.Log("exception in outgoing delegate: " + e.Message, true);
proxy.Log(e.StackTrace, true);
}
if (packet != null)
proxy.SendPacket(packet, remoteEndPoint, packet.Data.Length, false);
} else
proxy.SendPacket(packet, remoteEndPoint, length, needsZero);
// send any packets queued for injection
if (firstReceive) {
firstReceive = false;
foreach (Packet queuedPacket in proxy.queuedIncomingInjections)
Inject(queuedPacket, Direction.Incoming);
proxy.queuedIncomingInjections = new ArrayList();
}
} catch (Exception e) {
Console.WriteLine(e.Message);
Console.WriteLine(e.StackTrace);
} finally {
// resume listening
socket.BeginReceiveFrom(receiveBuffer, 0, receiveBuffer.Length, SocketFlags.None, ref clientEndPoint, new AsyncCallback(ReceiveFromClient), null);
}}
// SendPacket: send a packet from the sim to the client via our fake sim endpoint
public void SendPacket(Packet packet, int length, bool skipZero) {
if (skipZero || (packet.Data[0] & Helpers.MSG_ZEROCODED) == 0)
socket.SendTo(packet.Data, length, SocketFlags.None, clientEndPoint);
else {
int zeroLength = Helpers.ZeroEncode(packet.Data, length, zeroBuffer);
socket.SendTo(zeroBuffer, zeroLength, SocketFlags.None, clientEndPoint);
}
}
// Inject: inject a packet
public void Inject(Packet packet, Direction direction) {
if (direction == Direction.Incoming) {
if (firstReceive) {
proxy.queuedIncomingInjections.Add(packet);
return;
}
incomingInjections.Add(++incomingSequence);
packet.Sequence = incomingSequence;
} else {
outgoingInjections.Add(++outgoingSequence);
packet.Sequence = outgoingSequence;
}
#if DEBUG_SEQUENCE
Console.WriteLine("INJECT " + (direction == Direction.Incoming ? "<-" : "->") + " " + packet.Layout.Name + " #" + packet.Sequence);
#endif
if ((packet.Data[0] & Helpers.MSG_RELIABLE) != 0)
WaitForAck(packet, direction);
if (direction == Direction.Incoming)
if ((packet.Data[0] & Helpers.MSG_ZEROCODED) == 0)
socket.SendTo(packet.Data, packet.Data.Length, SocketFlags.None, clientEndPoint);
else {
int zeroLength = Helpers.ZeroEncode(packet.Data, packet.Data.Length, zeroBuffer);
socket.SendTo(zeroBuffer, zeroLength, SocketFlags.None, clientEndPoint);
}
else
proxy.SendPacket(packet, remoteEndPoint, packet.Data.Length, false);
}
// WaitForAck: take care of resending a packet until it's ACKed
public void WaitForAck(Packet packet, Direction direction) {
Hashtable table = direction == Direction.Incoming ? incomingAcks : outgoingAcks;
table.Add(packet.Sequence, packet);
}
// CheckAcks: check for and remove ACKs of packets we've injected
public Packet CheckAcks(Packet packet, Direction direction, ref int length, ref bool needsCopy) {
Hashtable acks = direction == Direction.Incoming ? outgoingAcks : incomingAcks;
ArrayList seenAcks = direction == Direction.Incoming ? outgoingSeenAcks : incomingSeenAcks;
if (acks.Count == 0)
return packet;
// check for embedded ACKs
if (packet.Layout.Name == "PacketAck") {
bool changed = false;
Hashtable blocks = PacketUtility.Unbuild(packet);
Hashtable newBlocks = new Hashtable();
foreach (Hashtable fields in blocks.Keys) {
ushort id = (ushort)((uint)fields["ID"]);
#if DEBUG_SEQUENCE
string hrup = "Check !" + id;
#endif
if (acks.Contains(id)) {
#if DEBUG_SEQUENCE
hrup += " get's";
#endif
seenAcks.Add(id);
changed = true;
} else
newBlocks.Add(fields, blocks[fields]);
#if DEBUG_SEQUENCE
Console.WriteLine(hrup);
#endif
}
if (changed) {
Packet newPacket = PacketBuilder.BuildPacket("PacketAck", proxyConfig.protocol, newBlocks, packet.Data[0]);
SwapPacket(packet, newPacket, length);
packet = newPacket;
length = packet.Data.Length;
needsCopy = false;
}
}
// check for appended ACKs
if ((packet.Data[0] & Helpers.MSG_APPENDED_ACKS) != 0) {
byte ackCount = packet.Data[length - 1];
for (int i = 0; i < ackCount;) {
int offset = length - (ackCount - i) * 4 - 1;
ushort ackID = (ushort)(packet.Data[offset + 3] + (packet.Data[offset + 2] << 8));
#if DEBUG_SEQUENCE
string hrup = "Check @" + ackID;
#endif
if (acks.Contains(ackID)) {
#if DEBUG_SEQUENCE
hrup += " get's";
#endif
byte[] newData = new byte[length -= 4];
Array.Copy(packet.Data, 0, newData, 0, offset);
Array.Copy(packet.Data, offset + 4, newData, offset, length - offset - 4);
--newData[newData.Length - 1];
packet.Data = newData;
--ackCount;
seenAcks.Add(ackID);
needsCopy = false;
} else
++i;
#if DEBUG_SEQUENCE
Console.WriteLine(hrup);
#endif
}
if (ackCount == 0) {
byte[] newData = new byte[length -= 1];
Array.Copy(packet.Data, 0, newData, 0, length);
newData[0] ^= Helpers.MSG_APPENDED_ACKS;
packet.Data = newData;
}
}
return packet;
}
// ModifySequence: modify a packet's sequence number and ACK IDs to account for injections
public Packet ModifySequence(Packet packet, Direction direction, ref int length, ref bool needsCopy) {
ArrayList ourInjections = direction == Direction.Outgoing ? outgoingInjections : incomingInjections;
ArrayList theirInjections = direction == Direction.Incoming ? outgoingInjections : incomingInjections;
ushort ourOffset = direction == Direction.Outgoing ? outgoingOffset : incomingOffset;
ushort theirOffset = direction == Direction.Incoming ? outgoingOffset : incomingOffset;
ushort newSequence = (ushort)(packet.Sequence + ourOffset);
foreach (ushort injection in ourInjections)
if (newSequence >= injection)
++newSequence;
#if DEBUG_SEQUENCE
Console.WriteLine("Mod #" + packet.Sequence + " = " + newSequence);
#endif
packet.Sequence = newSequence;
if ((packet.Data[0] & Helpers.MSG_APPENDED_ACKS) != 0) {
int ackCount = packet.Data[length - 1];
for (int i = 0; i < ackCount; ++i) {
int offset = length - (ackCount - i) * 4 - 1;
uint ackID = (uint)(packet.Data[offset + 3] + (packet.Data[offset + 2] << 8)) - theirOffset;
#if DEBUG_SEQUENCE
uint hrup = (uint)(packet.Data[offset + 3] + (packet.Data[offset + 2] << 8));
#endif
for (int j = theirInjections.Count - 1; j >= 0; --j)
if (ackID >= (ushort)theirInjections[j])
--ackID;
#if DEBUG_SEQUENCE
Console.WriteLine("Mod @" + hrup + " = " + ackID);
#endif
packet.Data[offset + 3] = (byte)(ackID % 256);
packet.Data[offset + 2] = (byte)(ackID / 256);
}
}
if (packet.Layout.Name == "PacketAck") {
Hashtable blocks = PacketUtility.Unbuild(packet);
foreach (Hashtable fields in blocks.Keys) {
if ((string)blocks[fields] == "Packets") {
uint ackID = (uint)fields["ID"] - theirOffset;
#if DEBUG_SEQUENCE
uint hrup = (uint)fields["ID"];
#endif
for (int i = theirInjections.Count - 1; i >= 0; --i)
if (ackID >= (ushort)theirInjections[i])
--ackID;
#if DEBUG_SEQUENCE
Console.WriteLine("Mod !" + hrup + " = " + ackID);
#endif
fields["ID"] = ackID;
}
}
Packet newPacket = PacketBuilder.BuildPacket("PacketAck", proxyConfig.protocol, blocks, packet.Data[0]);
SwapPacket(packet, newPacket, length);
packet = newPacket;
length = packet.Data.Length;
needsCopy = false;
}
return packet;
}
}
// Checkers swap proxy addresses in for real addresses. A few constraints:
// - Checkers must not alter the incoming packet.
// - Checkers must return a freshly built packet, even if nothing's changed.
// - The incoming packet's buffer may be longer than the length of the data it contains.
// - The incoming packet's buffer must not be used after the checker returns.
// This is all because checkers may be operating on data that's still in a scratch buffer.
delegate Packet AddressChecker(Packet packet);
Hashtable incomingCheckers = new Hashtable();
Hashtable outgoingCheckers = new Hashtable();
// InitializeAddressCheckers: initialize delegates that check packets for addresses that need proxying
private void InitializeAddressCheckers() {
// TODO: what do we do with mysteries and empty IPs?
AddMystery("OpenCircuit");
AddMystery("AgentPresenceResponse");
incomingCheckers.Add("TeleportFinish", new AddressChecker(CheckTeleportFinish));
// ViewerStats: IP is 0.0.0.0
incomingCheckers.Add("AgentToNewRegion", new AddressChecker(CheckAgentToNewRegion));
incomingCheckers.Add("CrossedRegion", new AddressChecker(CheckCrossedRegion));
incomingCheckers.Add("EnableSimulator", new AddressChecker(CheckEnableSimulator));
// KickUser: IP is 0.0.0.0
incomingCheckers.Add("UserLoginLocationReply", new AddressChecker(CheckUserLoginLocationReply));
}
// AddMystery: add a checker delegate that logs packets we're watching for development purposes
private void AddMystery(String name) {
incomingCheckers.Add(name, new AddressChecker(LogIncomingMysteryPacket));
outgoingCheckers.Add(name, new AddressChecker(LogOutgoingMysteryPacket));
}
// GenericCheck: replace the sim address in a packet with our proxy address
private Packet GenericCheck(Packet packet, string block, string fieldIP, string fieldPort, bool active) {
Hashtable blocks = PacketUtility.Unbuild(packet);
IPEndPoint realSim = new IPEndPoint((IPAddress)PacketUtility.GetField(blocks, block, fieldIP), Convert.ToInt32(PacketUtility.GetField(blocks, block, fieldPort)));
IPEndPoint fakeSim = ProxySim(realSim);
PacketUtility.SetField(blocks, block, fieldIP, fakeSim.Address);
PacketUtility.SetField(blocks, block, fieldPort, (ushort)fakeSim.Port);
if (active)
activeCircuit = realSim;
return PacketBuilder.BuildPacket(packet.Layout.Name, proxyConfig.protocol, blocks, packet.Data[0]);
}
// CheckTeleportFinish: check TeleportFinish packets
private Packet CheckTeleportFinish(Packet packet) {
return GenericCheck(packet, "Info", "SimIP", "SimPort", true);
}
// CheckAgentToNewRegion: check AgentToNewRegion packets
private Packet CheckAgentToNewRegion(Packet packet) {
return GenericCheck(packet, "RegionData", "IP", "Port", true);
}
// CheckEnableSimulator: check EnableSimulator packets
private Packet CheckEnableSimulator(Packet packet) {
return GenericCheck(packet, "SimulatorInfo", "IP", "Port", false);
}
// CheckCrossedRegion: check CrossedRegion packets
private Packet CheckCrossedRegion(Packet packet) {
return GenericCheck(packet, "RegionData", "SimIP", "SimPort", true);
}
// CheckUserLoginLocationReply: check UserLoginLocationReply packets
private Packet CheckUserLoginLocationReply(Packet packet) {
return GenericCheck(packet, "SimulatorBlock", "IP", "Port", true);
}
// LogPacket: log a packet dump
private Packet LogPacket(Packet packet, string type) {
Log(type + " packet:", true);
Log(packet, true);
return PacketBuilder.BuildPacket(packet.Layout.Name, proxyConfig.protocol, PacketUtility.Unbuild(packet), packet.Data[0]);
}
// LogIncomingMysteryPacket: log an incoming packet we're watching for development purposes
private Packet LogIncomingMysteryPacket(Packet packet) {
return LogPacket(packet, "incoming mystery");
}
// LogOutgoingMysteryPacket: log an outgoing packet we're watching for development purposes
private Packet LogOutgoingMysteryPacket(Packet packet) {
return LogPacket(packet, "outgoing mystery");
}
}
// XmlRpcRequestDelegate: specifies a delegate to be called for XML-RPC requests
public delegate void XmlRpcRequestDelegate(XmlRpcRequest request);
// XmlRpcResponseDelegate: specifies a delegate to be called for XML-RPC responses
public delegate void XmlRpcResponseDelegate(XmlRpcResponse response);
// PacketDelegate: specifies a delegate to be called when a packet passes through the proxy
public delegate Packet PacketDelegate(Packet packet, IPEndPoint endPoint);
// Direction: specifies whether a packet is going to the client (Incoming) or to a sim (Outgoing)
public enum Direction {
Incoming,
Outgoing
}
// PacketUtility: provides various utility methods for working with libsecondlife Packet objects
public class PacketUtility {
// Unbuild: deconstruct a packet into a Hashtable of blocks suitable for passing to PacketBuilder
public static Hashtable Unbuild(Packet packet) {
Hashtable blockTable = new Hashtable();
foreach (Block block in packet.Blocks()) {
Hashtable fieldTable = new Hashtable();
foreach (Field field in block.Fields)
fieldTable[field.Layout.Name] = field.Data;
blockTable[fieldTable] = block.Layout.Name;
}
return blockTable;
}
// GetField: given a table of blocks, return the value of the specified block and field
// In the case of packets with variable blocks, an arbitrary block will be used.
public static object GetField(Hashtable blocks, string block, string field) {
foreach (Hashtable fields in blocks.Keys)
if ((string)blocks[fields] == block)
if (fields.Contains(field))
return fields[field];
return null;
}
// SetField: given a table of blocks, update the value of the specified block and field
// In the case of packets with variable blocks, all blocks will be updated.
public static void SetField(Hashtable blocks, string block, string field, object value) {
foreach (Hashtable fields in blocks.Keys)
if ((string)blocks[fields] == block)
if (fields.Contains(field))
fields[field] = value;
}
}
}