/*
=================
CL_PacketEvent
A packet has arrived from the main event loop
=================
*/
public void PacketEvent(Net.Packet packet)
{
clc.lastPacketTime = realtime;
if (packet.Type == NetMessageType.OutOfBandData)
{
ConnectionlessPacket(packet);
return;
}
if (state < ConnectState.CONNECTED)
return; // can't be a valid sequenced packet
//
// packet from server
//
if (!IPAddress.Equals(packet.Address.Address, clc.netchan.remoteAddress.Address))
{
Common.Instance.WriteLine("{0}: sequence packet without connection", packet.Address.Address.ToString());
return;
}
if (!NetChan_Process(clc.netchan, packet))
return; // out of order, duplicated, etc
// the header is different lengths for reliable and unreliable messages
int headerBytes = packet.Buffer.Position;
// track the last message received so it can be returned in
// client messages, allowing the server to detect a dropped
// gamestate
int oldpos = packet.Buffer.Position;
packet.Buffer.Position = 0;
clc.serverMessageSequence = packet.Buffer.ReadInt32();
packet.Buffer.Position = oldpos;
clc.lastPacketTime = realtime;
ParseServerMessage(packet);
}
void ConnectionlessPacket(Net.Packet packet)
{
string s = packet.Buffer.ReadString();
string[] tokens = Commands.TokenizeString(s);
Common.Instance.WriteLine("CL Packet: {0}:{1}: {2}", packet.Address.Address, packet.Address.Port, s);
string c = tokens[0];
if (c.Equals("challengeResponse"))
{
if (state != ConnectState.CONNECTING)
{
Common.Instance.WriteLine("Unwanted challenge response recieved. Ignored.");
return;
}
if (!IPAddress.Equals(clc.serverAddress.Address, packet.Address.Address))
{
// This challenge response is not coming from the expected address.
// Check whether we have a matching client challenge to prevent
// connection hi-jacking.
c = tokens[2];
if (!int.Parse(c).Equals(clc.challenge))
{
Common.Instance.WriteLine("Challenge response recieved from unexpected source. Ignored.");
return;
}
}
// start sending challenge response instead of challenge request packets
clc.challenge = int.Parse(tokens[1]);
state = ConnectState.CHALLENGING;
clc.connectPacketCount = 0;
clc.connectTime = -99999;
// take this address as the new server address. This allows
// a server proxy to hand off connections to multiple servers
clc.serverAddress = packet.Address;
Common.Instance.WriteLine("Challenge response: {0}", clc.challenge);
return;
}
// server connection
if (c.Equals("connectResponse"))
{
if ((int)state >= (int)ConnectState.CONNECTED)
{
Common.Instance.WriteLine("Duplicate connect recieved. Ignored");
return;
}
if (state != ConnectState.CHALLENGING)
{
Common.Instance.WriteLine("connectResponse packet while not connecting. Ignored.");
return;
}
if (!IPAddress.Equals(packet.Address.Address, clc.serverAddress.Address))
{
Common.Instance.WriteLine("connectResponse from wrong address. Ignored");
}
clc.netchan = Net.Instance.NetChan_Setup(Net.NetSource.CLIENT, packet.Address, CVars.Instance.VariableIntegerValue("net_qport"));
Net.Instance.ClientConnect(packet.Address);
state = ConnectState.CONNECTED;
clc.lastPacketSentTime = -99999; // send first packet immediately
return;
}
if (c.Equals("print"))
{
s = tokens[1];
clc.serverMessage = s;
Common.Instance.WriteLine(s);
return;
}
Common.Instance.WriteLine("Unknown connectionless packet: {0}" + s);
}
void ParseServerMessage(Net.Packet packet)
{
// get the reliable sequence acknowledge number
clc.reliableAcknowledge = packet.Buffer.ReadInt32();
if (clc.reliableAcknowledge < clc.reliableSequence - 64)
{
clc.reliableAcknowledge = clc.reliableSequence;
}
//
// parse the message
//
NetBuffer buf = packet.Buffer;
while (true)
{
int cmd = buf.ReadByte();
// See if this is an extension command after the EOF, which means we
// got data that a legacy client should ignore.
if ((cmd == (int)svc_ops_e.svc_EOF) && (buf.PeekByte() == (int)clc_ops_e.clc_extension))
{
//Common.Instance.WriteLine("NET: EXTENSION");
buf.ReadByte(); // throw the svc_extension byte away.
cmd = buf.ReadByte(); // something legacy clients can't do!
// sometimes you get a svc_extension at end of stream...dangling
// bits in the huffman decoder giving a bogus value?
if (cmd == -1)
cmd = (int)svc_ops_e.svc_EOF;
}
if (cmd == (int)svc_ops_e.svc_EOF)
{
// END OF MESSAGE
break;
}
switch (cmd)
{
case (int)svc_ops_e.svc_serverCommand:
ParseCommandString(buf);
break;
case (int)svc_ops_e.svc_gamestate:
ParseGameState(buf);
break;
case (int)svc_ops_e.svc_snapshot:
ParseSnapshot(buf);
break;
case (int)svc_ops_e.svc_download:
//ParseDownload(buf);
break;
case (int)svc_ops_e.svc_nop:
break;
default:
Common.Instance.Error("Illegible server message");
break;
}
}
}
bool NetChan_Process(Net.netchan_t chan, Net.Packet packet)
{
bool ret = Net.Instance.NetChan_Process(chan, packet);
return ret;
}
public void NetChan_Transmit(Net.netchan_t chan, NetBuffer msg)
{
msg.Write((byte)clc_ops_e.clc_EOF);
Net.Instance.NetChan_Transmit(chan, msg);
}
/*
=================
SV_ConnectionlessPacket
A connectionless packet has four leading 0xff
characters to distinguish it from a game channel.
Clients that are in the game can still send
connectionless packets.
=================
*/
void ConnectionLessPacket(Net.Packet packet)
{
NetBuffer buf = packet.Buffer;
string data = buf.ReadString();
Common.Instance.WriteLine("SV_ConnLessPacket: {0}=>{1}", packet.Address, data);
string[] tokens = Commands.TokenizeString(data);
string c = tokens[0];
if (c.Equals("getchallenge"))
{
GetChallenge(packet.Address, tokens[1]);
}
else if (c.Equals("connect"))
{
DirectConnect(packet.Address, tokens);
}
}
/*
=================
SV_PacketEvent
A packet has arrived from the main event loop
=================
*/
public void PacketEvent(Net.Packet packet)
{
// check for connectionless packet (0xffffffff) first
if (packet.Type == Lidgren.Network.NetMessageType.OutOfBandData)
{
ConnectionLessPacket(packet);
return;
}
// read the qport out of the message so we can fix up
// stupid address translating routers
NetBuffer buf = packet.Buffer;
buf.ReadInt32();
int qport = buf.ReadInt16() & 0xffff;
// find which client the message is from
for (int i = 0; i < clients.Count; i++)
{
client_t client = clients[i];
if (client.state == clientState_t.CS_FREE)
continue;
if (!packet.Address.Address.Equals(client.netchan.remoteAddress.Address))
continue;
// it is possible to have multiple clients from a single IP
// address, so they are differentiated by the qport variable
if (client.netchan.qport != qport)
{
continue;
}
// the IP port can't be used to differentiate them, because
// some address translating routers periodically change UDP
// port assignments
if (client.netchan.remoteAddress.Port != packet.Address.Port)
{
Common.Instance.WriteLine("PacketEvent: fixing up translation port");
client.netchan.remoteAddress.Port = packet.Address.Port;
}
// make sure it is a valid, in sequence packet
//??
// zombie clients still need to do the Netchan_Process
// to make sure they don't need to retransmit the final
// reliable message, but they don't do any other processing
if (client.state != clientState_t.CS_ZOMBIE)
{
client.lastPacketTime = time; // don't timeout
ExecuteClientMessage(client, buf);
}
return;
}
// if we received a sequenced packet from an address we don't recognize,
// send an out of band disconnect packet to it
Net.Instance.OutOfBandMessage(Net.NetSource.SERVER, packet.Address, "disconnect");
}
