1 files changed, 190 insertions, 0 deletions
diff --git a/src/client/cl_net_chan.cpp b/src/client/cl_net_chan.cpp
new file mode 100644
index 0000000..80ac25d
--- /dev/null
+++ b/src/client/cl_net_chan.cpp
@@ -0,0 +1,190 @@
+/*
+===========================================================================
+Copyright (C) 1999-2005 Id Software, Inc.
+Copyright (C) 2000-2013 Darklegion Development
+Copyright (C) 2015-2019 GrangerHub
+
+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 3 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, see <https://www.gnu.org/licenses/>
+
+===========================================================================
+*/
+
+#include "client.h"
+
+#include "qcommon/q_shared.h"
+#include "qcommon/qcommon.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, idx, srdc, sbit;
+    bool 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 = false;
+
+    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)];
+    idx = 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[idx]) idx = 0;
+        if (string[idx] > 127 || (string[idx] == '%' && clc.netchan.alternateProtocol == 2))
+        {
+            key ^= '.' << (i & 1);
+        }
+        else
+        {
+            key ^= string[idx] << (i & 1);
+        }
+        idx++;
+        // 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, idx;
+    byte key, *string;
+    int srdc, sbit;
+    bool soob;
+
+    srdc = msg->readcount;
+    sbit = msg->bit;
+    soob = msg->oob;
+
+    msg->oob = false;
+
+    reliableAcknowledge = MSG_ReadLong(msg);
+
+    msg->oob = soob;
+    msg->bit = sbit;
+    msg->readcount = srdc;
+
+    string = (byte *)clc.reliableCommands[reliableAcknowledge & (MAX_RELIABLE_COMMANDS - 1)];
+    idx = 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[idx]) idx = 0;
+        if (string[idx] > 127 || (string[idx] == '%' && clc.netchan.alternateProtocol == 2))
+        {
+            key ^= '.' << (i & 1);
+        }
+        else
+        {
+            key ^= string[idx] << (i & 1);
+        }
+        idx++;
+        // decode the data with this key
+        *(msg->data + i) = *(msg->data + i) ^ key;
+    }
+}
+
+/*
+=================
+CL_Netchan_TransmitNextFragment
+=================
+*/
+static bool CL_Netchan_TransmitNextFragment(netchan_t *chan)
+{
+    if (chan->unsentFragments)
+    {
+        Netchan_TransmitNextFragment(chan);
+        return true;
+    }
+
+    return false;
+}
+
+/*
+===============
+CL_Netchan_Transmit
+================
+*/
+void CL_Netchan_Transmit(netchan_t *chan, msg_t *msg)
+{
+    MSG_WriteByte(msg, clc_EOF);
+
+    if (chan->alternateProtocol != 0) CL_Netchan_Encode(msg);
+    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
+=================
+*/
+bool CL_Netchan_Process(netchan_t *chan, msg_t *msg)
+{
+    int ret;
+
+    ret = Netchan_Process(chan, msg);
+    if (!ret) return false;
+    if (chan->alternateProtocol != 0) CL_Netchan_Decode(msg);
+
+    return true;
+}