diff options
Diffstat (limited to 'src/client/cl_net_chan.c')
| -rw-r--r-- | src/client/cl_net_chan.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/src/client/cl_net_chan.c b/src/client/cl_net_chan.c new file mode 100644 index 0000000..ef214fe --- /dev/null +++ b/src/client/cl_net_chan.c @@ -0,0 +1,168 @@ +/* +=========================================================================== +Copyright (C) 1999-2005 Id Software, Inc. +Copyright (C) 2000-2006 Tim Angus + +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" + +/* +============== +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 || string[index] == '%') { + 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 || string[index] == '%') { + key ^= '.' << (i & 1); + } + else { + key ^= string[index] << (i & 1); + } + index++; + // decode the data with this key + *(msg->data + i) = *(msg->data + i) ^ key; + } +} + +/* +================= +CL_Netchan_TransmitNextFragment +================= +*/ +void CL_Netchan_TransmitNextFragment( netchan_t *chan ) { + Netchan_TransmitNextFragment( chan ); +} + +/* +=============== +CL_Netchan_Transmit +================ +*/ +void CL_Netchan_Transmit( netchan_t *chan, msg_t* msg ) { + MSG_WriteByte( msg, clc_EOF ); + + CL_Netchan_Encode( msg ); + Netchan_Transmit( chan, msg->cursize, msg->data ); +} + +extern int oldsize; +int newsize = 0; + +/* +================= +CL_Netchan_Process +================= +*/ +qboolean CL_Netchan_Process( netchan_t *chan, msg_t *msg ) { + int ret; + + ret = Netchan_Process( chan, msg ); + if (!ret) + return qfalse; + CL_Netchan_Decode( msg ); + newsize += msg->cursize; + return qtrue; +} |