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/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
Copyright (C) 2000-2009 Darklegion Development
This file is part of Tremulous.
Tremulous is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.
Tremulous is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Tremulous; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
#include "../qcommon/q_shared.h"
#include "../qcommon/qcommon.h"
#include "client.h"
#ifdef LEGACY_PROTOCOL
/*
==============
CL_Netchan_Encode
// first 12 bytes of the data are always:
long serverId;
long messageAcknowledge;
long reliableAcknowledge;
==============
*/
static void CL_Netchan_Encode( msg_t *msg ) {
int serverId, messageAcknowledge, reliableAcknowledge;
int i, index, srdc, sbit, soob;
byte key, *string;
if ( msg->cursize <= CL_ENCODE_START ) {
return;
}
srdc = msg->readcount;
sbit = msg->bit;
soob = msg->oob;
msg->bit = 0;
msg->readcount = 0;
msg->oob = 0;
serverId = MSG_ReadLong(msg);
messageAcknowledge = MSG_ReadLong(msg);
reliableAcknowledge = MSG_ReadLong(msg);
msg->oob = soob;
msg->bit = sbit;
msg->readcount = srdc;
string = (byte *)clc.serverCommands[ reliableAcknowledge & (MAX_RELIABLE_COMMANDS-1) ];
index = 0;
//
key = clc.challenge ^ serverId ^ messageAcknowledge;
for (i = CL_ENCODE_START; i < msg->cursize; i++) {
// modify the key with the last received now acknowledged server command
if (!string[index])
index = 0;
if (string[index] > 127) {
key ^= '.' << (i & 1);
}
else {
key ^= string[index] << (i & 1);
}
index++;
// encode the data with this key
*(msg->data + i) = (*(msg->data + i)) ^ key;
}
}
/*
==============
CL_Netchan_Decode
// first four bytes of the data are always:
long reliableAcknowledge;
==============
*/
static void CL_Netchan_Decode( msg_t *msg ) {
long reliableAcknowledge, i, index;
byte key, *string;
int srdc, sbit, soob;
srdc = msg->readcount;
sbit = msg->bit;
soob = msg->oob;
msg->oob = 0;
reliableAcknowledge = MSG_ReadLong(msg);
msg->oob = soob;
msg->bit = sbit;
msg->readcount = srdc;
string = (byte *) clc.reliableCommands[ reliableAcknowledge & (MAX_RELIABLE_COMMANDS-1) ];
index = 0;
// xor the client challenge with the netchan sequence number (need something that changes every message)
key = clc.challenge ^ LittleLong( *(unsigned *)msg->data );
for (i = msg->readcount + CL_DECODE_START; i < msg->cursize; i++) {
// modify the key with the last sent and with this message acknowledged client command
if (!string[index])
index = 0;
if (string[index] > 127) {
key ^= '.' << (i & 1);
}
else {
key ^= string[index] << (i & 1);
}
index++;
// decode the data with this key
*(msg->data + i) = *(msg->data + i) ^ key;
}
}
#endif
/*
=================
CL_Netchan_TransmitNextFragment
=================
*/
qboolean CL_Netchan_TransmitNextFragment(netchan_t *chan)
{
if(chan->unsentFragments)
{
Netchan_TransmitNextFragment(chan);
return qtrue;
}
return qfalse;
}
/*
===============
CL_Netchan_Transmit
================
*/
void CL_Netchan_Transmit( netchan_t *chan, msg_t* msg ) {
MSG_WriteByte( msg, clc_EOF );
#ifdef LEGACY_PROTOCOL
if(chan->compat)
CL_Netchan_Encode(msg);
#endif
Netchan_Transmit(chan, msg->cursize, msg->data);
// Transmit all fragments without delay
while(CL_Netchan_TransmitNextFragment(chan))
{
Com_DPrintf("WARNING: #462 unsent fragments (not supposed to happen!)\n");
}
}
/*
=================
CL_Netchan_Process
=================
*/
qboolean CL_Netchan_Process( netchan_t *chan, msg_t *msg ) {
int ret;
ret = Netchan_Process( chan, msg );
if (!ret)
return qfalse;
#ifdef LEGACY_PROTOCOL
if(chan->compat)
CL_Netchan_Decode(msg);
#endif
return qtrue;
}
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