CSSZombieEscape/sm-ext-Voice
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Add fix for voice related unreliable netchannel overflow exploit

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This commit is contained in:
BotoX 2020-08-30 14:16:56 +02:00
parent 7855fd04a2
commit c4f5affecd
2 changed files with 35 additions and 10 deletions
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39
extension.cpp
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@ -46,6 +46,14 @@
#include "CDetour/detours.h"
#include "extension.h"
// voice packets are sent over unreliable netchannel
//#define NET_MAX_DATAGRAM_PAYLOAD 4000 // = maximum unreliable payload size
// voice packetsize = 64 | netchannel overflows at >4000 bytes
// with 22050 samplerate and 512 frames per packet -> 23.22ms per packet
// SVC_VoiceData overhead = 5 bytes
// sensible limit of 8 packets per frame = 552 bytes -> 185.76ms of voice data per frame
#define NET_MAX_VOICE_BYTES_FRAME (8 * (5 + 64))
ConVar g_SmVoiceAddr("sm_voice_addr", "127.0.0.1", FCVAR_PROTECTED, "Voice server listen ip address.");
ConVar g_SmVoicePort("sm_voice_port", "27020", FCVAR_PROTECTED, "Voice server listen port.", true, 1025.0, true, 65535.0);
@ -64,11 +72,11 @@ ISDKTools *g_pSDKTools = NULL;
IServer *iserver = NULL;
double g_fLastVoiceData[SM_MAXPLAYERS + 1];
int g_aFrameVoiceBytes[SM_MAXPLAYERS + 1];
DETOUR_DECL_STATIC4(SV_BroadcastVoiceData, void, IClient *, pClient, int, nBytes, char *, data, int64, xuid)
{
g_Interface.OnBroadcastVoiceData(pClient, nBytes, data);
if(g_Interface.OnBroadcastVoiceData(pClient, nBytes, data))
DETOUR_STATIC_CALL(SV_BroadcastVoiceData)(pClient, nBytes, data, xuid);
}
@ -81,11 +89,12 @@ DETOUR_DECL_STATIC2(SV_BroadcastVoiceData_LTCG, void, char *, data, int64, xuid)
__asm mov pClient, ecx;
__asm mov nBytes, edx;
g_Interface.OnBroadcastVoiceData(pClient, nBytes, data);
bool ret = g_Interface.OnBroadcastVoiceData(pClient, nBytes, data);
__asm mov ecx, pClient;
__asm mov edx, nBytes;
if(ret)
DETOUR_STATIC_CALL(SV_BroadcastVoiceData_LTCG)(data, xuid);
}
#endif
@ -409,13 +418,29 @@ void CVoice::OnGameFrame(bool simulating)
{
HandleNetwork();
HandleVoiceData();
// Reset per-client voice byte counter to 0 every frame.
memset(g_aFrameVoiceBytes, 0, sizeof(g_aFrameVoiceBytes));
}
void CVoice::OnBroadcastVoiceData(IClient *pClient, int nBytes, char *data)
bool CVoice::OnBroadcastVoiceData(IClient *pClient, int nBytes, char *data)
{
// Reject empty packets
if(nBytes < 1)
return false;
int client = pClient->GetPlayerSlot() + 1;
// Reject voice packet if we'd send more than NET_MAX_VOICE_BYTES_FRAME voice bytes from this client in the current frame.
// 5 = SVC_VoiceData header/overhead
g_aFrameVoiceBytes[client] += 5 + nBytes;
if(g_aFrameVoiceBytes[client] > NET_MAX_VOICE_BYTES_FRAME)
return false;
g_fLastVoiceData[client] = gpGlobals->curtime;
return true;
}
void CVoice::HandleNetwork()
@ -456,7 +481,7 @@ void CVoice::HandleNetwork()
m_aPollFds[m_PollFds].revents = 0;
m_PollFds++;
smutils->LogMessage(myself, "Client %d connected!\n", Client);
//smutils->LogMessage(myself, "Client %d connected!\n", Client);
}
}
@ -482,7 +507,7 @@ void CVoice::HandleNetwork()
pClient->m_Socket = -1;
m_aPollFds[PollFds].fd = -1;
CompressPollFds = true;
smutils->LogMessage(myself, "Client %d disconnected!(2)\n", Client);
//smutils->LogMessage(myself, "Client %d disconnected!(2)\n", Client);
continue;
}
@ -515,7 +540,7 @@ void CVoice::HandleNetwork()
pClient->m_Socket = -1;
m_aPollFds[PollFds].fd = -1;
CompressPollFds = true;
smutils->LogMessage(myself, "Client %d disconnected!(1)\n", Client);
//smutils->LogMessage(myself, "Client %d disconnected!(1)\n", Client);
continue;
}

2
extension.h
View File

@ -137,7 +137,7 @@ public: // IConCommandBaseAccessor
public:
CVoice();
void OnGameFrame(bool simulating);
void OnBroadcastVoiceData(IClient *pClient, int nBytes, char *data);
bool OnBroadcastVoiceData(IClient *pClient, int nBytes, char *data);
private:
int m_ListenSocket;