protected virtual void ProcessAuthentication(SkylakeNATClient socket)
{
IPAddress localIP = this.AddressAllocation(socket.Id);
if (localIP == null)
{
socket.Close();
}
else
{
if (this.ResponseAuthentication(socket, localIP, this._dhcpServerAddress, this._dnsServerAddress))
{
lock (this._sockets)
{
if (!_sockets.TryGetValue(socket.Address, out LinkedList <SkylakeNATClient> s) || s == null)
{
s = new LinkedList <SkylakeNATClient>();
_sockets[socket.Address] = s;
#if __USE_UDP_PAYLOAD_TAP_PACKET
s.AddLast(socket);
#endif
}
#if !__USE_UDP_PAYLOAD_TAP_PACKET
if (s != null)
{
socket._rsv_current = s.AddLast(socket);
}
#endif
}
}
#if __USE_UDP_PAYLOAD_TAP_PACKET
Console.WriteLine($"[{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")}] {socket.Id} {socket.Address} {socket.LocalEndPoint}");
#endif
}
}
protected virtual bool Send(IPAddress address, Func <SkylakeNATMessage> message, int sent = 1)
{
if (address == null || message == null)
{
return(false);
}
SkylakeNATClient socket = this.GetClient(address, out int sessions);
if (socket == null)
{
return(false);
}
SkylakeNATMessage packet = message();
if (!socket.Send(packet, sent))
{
for (int i = 0; i < sessions; i++)
{
socket = this.GetClient(address, out sessions);
if (socket == null)
{
break;
}
if (socket.Send(packet, sent))
{
return(true);
}
}
}
return(false);
}
protected virtual void ProcessMessage(SkylakeNATClient socket, SkylakeNATMessage message)
{
if (message.Commands == Commands.NATCommands_kEthernetOutput)
{
IPFrame packet = IPv4Layer.ParseFrame(message.Payload, false);
if (packet != null)
{
if (this._sockets.ContainsKey(packet.Source))
{
this.PrivateInput(socket, packet);
}
else
{
this.CloseManyClient(socket.Address);
}
}
}
}
protected virtual bool ResponseAuthentication(SkylakeNATClient socket, IPAddress local, IPAddress dhcp, IPAddress dns)
{
byte[] message = new byte[sizeof(NATAuthenticationResponse)];
fixed(byte *pinned = message)
{
NATAuthenticationResponse *response = (NATAuthenticationResponse *)pinned;
response->dhcp.local = (uint)Ethernet.GetAddress(local);
response->dhcp.dhcp = (uint)Ethernet.GetAddress(dhcp);
response->dhcp.dns = (uint)Ethernet.GetAddress(dns);
}
socket.Address = local;
return(socket.Send(new SkylakeNATMessage(new BufferSegment(message))
{
Commands = Commands.NATCommands_kAuthentication,
}));
}
protected virtual SkylakeNATClient GetClient(IPAddress address, out int sessions)
{
sessions = 0;
SkylakeNATClient socket = null;
lock (this._sockets)
{
if (_sockets.TryGetValue(address, out LinkedList <SkylakeNATClient> s) && s != null)
{
var node = s.First;
s.RemoveFirst();
s.AddLast(node);
socket = node.Value;
sessions = s.Count;
}
}
return(socket);
}
protected virtual bool CloseManyClient(IPAddress address)
{
if (address == null)
{
return(false);
}
lock (this._sockets)
{
_sockets.TryRemove(address, out LinkedList <SkylakeNATClient> s);
if (s == null)
{
return(false);
}
var node = s.First;
SkylakeNATClient socket = null;
while (node != null)
{
var i = node.Value;
if (i != null)
{
socket = i;
i.Close();
}
node = node.Next;
}
if (socket != null)
{
lock (_addressAllocation)
{
_addressAllocation.TryRemove(socket.Id, out IPAddress address_x);
if (socket.Address != null)
{
_assignedAddresses.Remove(socket.Address);
}
else if (address_x != null)
{
_assignedAddresses.Remove(address_x);
}
}
}
return(true);
}
}
private void ProcessReceiveFromUdp(IAsyncResult ar)
{
lock (this._syncobj)
{
try
{
if (this._disposed)
return; }
if (ar == null)
{
EndPoint remoteEP = this._server.LocalEndPoint;
this._server.BeginReceiveFrom(_mssPacketBuffer, 0, _mssPacketBuffer.Length, 0, ref remoteEP, ProcessReceiveFromUdp, null);
}
else
{
EndPoint remoteEP = new IPEndPoint(IPAddress.Any, 0);
int bytes = this._server.EndReceiveFrom(ar, ref remoteEP);
do
{
if (bytes < sizeof(pkg_hdr))
break;
fixed(byte *pinned = _mssPacketBuffer)
{
pkg_hdr *pkg = (pkg_hdr *)pinned;
if (pkg->fk != pkg_hdr.FK)
{
break;
}
if ((pkg->len + sizeof(pkg_hdr)) != bytes)
{
break;
}
if (pkg->id == 0)
{
break;
}
Commands commands = unchecked ((Commands)pkg->cmd);
if (commands == Commands.NATCommands_kAuthentication)
{
NATClientContext context = null;
SkylakeNATClient client = null;
lock (this._sockets)
{
if (!_natClientTable.TryGetValue(pkg->id, out context) || context == null)
{
client = this.CreateClient(pkg->id, remoteEP);
if (client != null)
{
client.LocalEndPoint = remoteEP;
context = new NATClientContext()
{
client = client
};
_natClientTable[pkg->id] = context;
client.Abort += this._onSocketAbort;
client.Message += this._onSocketMessage;
client.Authentication += this._onAuthentication;
}
}
else
{
client = context.client;
}
}
if (context != null && client != null)
{
lock (context)
{
context.agingsw.Restart();
}
client.LocalEndPoint = remoteEP;
client.OnAuthentication(EventArgs.Empty);
}
}
else
{
SkylakeNATClient client = null;
lock (this._sockets)
{
_natClientTable.TryGetValue(pkg->id, out NATClientContext context);
if (context != null)
{
lock (context)
{
context.agingsw.Restart();
}
client = context.client;
}
}
if (client != null)
{
BufferSegment payload = null;
if (pkg->len > 0)
{
int ofs = sizeof(pkg_hdr);
#if _USE_RC4_SIMPLE_ENCIPHER
fixed(byte *payloadPtr = &_mssPacketBuffer[ofs])
RC4.rc4_crypt(this.Key, payloadPtr, pkg->len, this.Subtract, 0);
#endif
payload = client._encryptor.Decrypt(new BufferSegment(_mssPacketBuffer, ofs, pkg->len));
}
else
{
payload = new BufferSegment(BufferSegment.Empty);
}
client.OnMessage(new SkylakeNATMessage(payload)
{
Commands = commands,
});
}
}
}
} while (false);
this.ProcessReceiveFromUdp(null);
}
}
protected virtual void PrivateInput(SkylakeNATClient socket, IPFrame packet)
{
this.NAT.PrivateInput(packet);
}
protected virtual void ProcessAbort(SkylakeNATClient socket)
{
this.NAT.Release(socket.Address);
}
public Router(IPAddress ethernet, int port, string key, int subtract)
{
if (ethernet == null)
{
throw new ArgumentNullException("It is not allowed to specify an ethernet card address with a null value");
}
if (IPEndPoint.MinPort >= port || port > IPEndPoint.MaxPort)
{
throw new ArgumentOutOfRangeException($"The port used to connect to the server is less than or equal to {IPEndPoint.MinPort} or greater than {IPEndPoint.MaxPort}");
}
this.Port = port;
this.Key = key;
this.Subtract = subtract;
#if !__USE_UDP_PAYLOAD_TAP_PACKET
this._server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
this._server.NoDelay = true;
this._server.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
#else
this._server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
this._server.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
#endif
this._server.Bind(new IPEndPoint(ethernet, port));
this._onSocketAbort = (sender, e) =>
{
if (sender is SkylakeNATClient socket)
{
socket.Close();
if (socket.Address != null)
{
lock (this._sockets)
{
bool deleteCompletely = false;
if (_sockets.TryGetValue(socket.Address, out LinkedList <SkylakeNATClient> s))
{
if (s == null)
{
deleteCompletely = true;
}
else
{
var node = socket._rsv_current;
if (node != null)
{
var l = node.List;
if (l != null)
{
l.Remove(node);
}
socket._rsv_current = null;
}
if (s.Count <= 0)
{
deleteCompletely = true;
}
}
}
if (deleteCompletely)
{
_sockets.TryRemove(socket.Address, out s);
lock (_addressAllocation)
{
_addressAllocation.TryRemove(socket.Id, out IPAddress address_x);
if (socket.Address != null)
{
_assignedAddresses.Remove(socket.Address);
}
else if (address_x != null)
{
_assignedAddresses.Remove(address_x);
}
}
}
}
this.ProcessAbort(socket);
}
}
};
this._onSocketMessage = (sender, e) =>
{
if (sender is SkylakeNATClient socket)
{
this.ProcessMessage(socket, e);
}
};
this._onAuthentication = (sender, e) =>
{
if (sender is SkylakeNATClient socket)
{
this.ProcessAuthentication(socket);
}
};
// 建立以太网NAT链路工作引擎
#if NO_USAGE_PCAP_NET
this.Ethernet = new Ethernet(ethernet, false);
#else
this.Ethernet = new Ethernet(ethernet, true);
#endif
this.NAT = new NAT(this.Ethernet.GetEthernetAddress());
// 建立以太网NAT传入传出链路
this.NAT.PublicOutput += (sender, e) => this.Ethernet.Output(e);
this.NAT.PrivateOutput += (seder, e) => this.PrivateOutput(e);
this.Ethernet.PublicInput += (sender, e) => this.NAT.PublicInput(e);
#if __USE_UDP_PAYLOAD_TAP_PACKET
this._doAgingswNatClientContextTimer = new Timer();
this._doAgingswNatClientContextTimer.Elapsed += (sender, e) =>
{
foreach (var kv in _natClientTable)
{
bool freely = false;
var context = kv.Value;
if (context == null)
{
freely = true;
}
else
{
SkylakeNATClient clients = null;
lock (context)
{
if (context.agingsw.ElapsedMilliseconds >= 10000)
{
freely = true;
clients = context.client;
}
}
clients?.OnAbort(EventArgs.Empty);
}
if (freely)
{
lock (this._sockets)
{
SkylakeNATClient clients = context.client;
if (clients != null)
{
IPAddress address = IPAddress.Any;
lock (_addressAllocation)
{
_addressAllocation.TryRemove(clients.Id, out address);
if (address == null)
{
address = clients.Address;
}
if (address != null && !Ethernet.Equals(address, IPAddress.Any))
{
_assignedAddresses.Remove(address);
_sockets.TryRemove(address, out LinkedList <SkylakeNATClient> linkedlist_xx);
}
}
}
_natClientTable.TryRemove(kv.Key, out NATClientContext context_xx);
}
}
}
};
this._doAgingswNatClientContextTimer.Interval = 500;
this._doAgingswNatClientContextTimer.Start();
#endif
}
