rooty/HLMetaModOfficial
1
0
Fork 0
mirror of https://github.com/alliedmodders/metamod-source.git synced 2025-01-18 07:52:32 +01:00
Code Issues Releases Activity

Rewrote user message caching code to always use IServerGameDLL::GetUserMessageInfo (bug 4117, r=dvander).

Browse Source 
Games where the above function can crash are handled by detouring tier0's Error() function and jumping back to our own code. So in theory this should work on all games now.
This commit is contained in:
Scott Ehlert 2009-12-10 00:59:50 -06:00
parent 405290aaaf
commit 1f1d6e57f9
8 changed files with 174 additions and 362 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

203
core-legacy/CSmmAPI.cpp
View File

@ -14,6 +14,8 @@
#include "concommands.h"
#include "CPlugin.h"
#include "util.h"
#include "sh_memory.h"
#include <setjmp.h>
/**
* @brief Implementation of main API interface
@ -21,22 +23,32 @@
*/
using namespace SourceMM;
using namespace SourceHook;
struct UsrMsgInfo
{
UsrMsgInfo()
{
}
UsrMsgInfo(int s, const char *t) : size(s), name(t)
{
}
int size;
String name;
};
CSmmAPI g_SmmAPI;
static CVector<UsrMsgInfo> usermsgs_list;
static jmp_buf usermsg_end;
CSmmAPI::CSmmAPI()
{
m_ConPrintf = NULL;
m_CmdCache = false;
m_MsgCount = -1;
m_VSP = false;
}
CSmmAPI::~CSmmAPI()
{
m_UserMessages.RemoveAll();
}
void CSmmAPI::LogMsg(ISmmPlugin *pl, const char *msg, ...)
{
va_list ap;
@ -491,149 +503,96 @@ int CSmmAPI::GetGameDLLVersion()
return g_GameDllVersion;
}
//////////////////////////////////////////////////////////////////////
// EVEN MORE HACKS HERE! YOU HAVE BEEN WARNED! //
// Signatures necessary in finding the pointer to the CUtlDict that //
// stores user message information. //
// IServerGameDLL::GetUserMessageInfo() normally crashes with bad //
// message indices. This is our answer to it. Yuck! <:-( //
//////////////////////////////////////////////////////////////////////
#ifdef OS_WIN32
/* General Windows sig */
#define MSGCLASS_SIGLEN 7
#define MSGCLASS_SIG "\x8B\x0D\x2A\x2A\x2A\x2A\x56"
#define MSGCLASS_OFFS 2
/* Dystopia Wimdows hack */
#define MSGCLASS2_SIGLEN 16
#define MSGCLASS2_SIG "\x56\x8B\x74\x24\x2A\x85\xF6\x7C\x2A\x3B\x35\x2A\x2A\x2A\x2A\x7D"
#define MSGCLASS2_OFFS 11
/* Windows frame pointer sig */
#define MSGCLASS3_SIGLEN 18
#define MSGCLASS3_SIG "\x55\x8B\xEC\x51\x89\x2A\x2A\x8B\x2A\x2A\x50\x8B\x0D\x2A\x2A\x2A\x2A\xE8"
#define MSGCLASS3_OFFS 13
#elif defined OS_LINUX
/* No frame pointer sig */
#define MSGCLASS_SIGLEN 14
#define MSGCLASS_SIG "\x53\x83\xEC\x2A\x8B\x2A\x2A\x2A\xA1\x2A\x2A\x2A\x2A\x89"
#define MSGCLASS_OFFS 9
/* Frame pointer sig */
#define MSGCLASS2_SIGLEN 16
#define MSGCLASS2_SIG "\x55\x89\xE5\x53\x83\xEC\x2A\x8B\x2A\x2A\xA1\x2A\x2A\x2A\x2A\x89"
#define MSGCLASS2_OFFS 11
#endif
/* This is the ugliest function in all of SourceMM */
/* :TODO: Make this prettier */
bool CSmmAPI::CacheUserMessages()
/* This only gets called if IServerGameDLL::GetUserMessageInfo() triggers it */
void Detour_Error(const tchar *pMsg, ...)
{
UserMsgDict *dict = NULL;
char *vfunc = UTIL_GetOrigFunction(&IServerGameDLL::GetUserMessageInfo, g_GameDll.pGameDLL);
if (!vfunc)
{
return false;
}
if (UTIL_VerifySignature(vfunc, MSGCLASS_SIG, MSGCLASS_SIGLEN))
{
/* Get address of CUserMessages instance */
char **userMsgClass = *reinterpret_cast<char ***>(vfunc + MSGCLASS_OFFS);
/* Get address of CUserMessages::m_UserMessages */
dict = reinterpret_cast<UserMsgDict *>(*userMsgClass);
} else if (UTIL_VerifySignature(vfunc, MSGCLASS2_SIG, MSGCLASS2_SIGLEN)) {
#ifdef OS_WIN32
/* If we get here, the code is possibly inlined like in Dystopia */
/* Get the address of the CUtlRBTree */
char *rbtree = *reinterpret_cast<char **>(vfunc + MSGCLASS2_OFFS);
/* CUtlDict should be 8 bytes before the CUtlRBTree (hacktacular!) */
dict = reinterpret_cast<UserMsgDict *>(rbtree - 8);
#elif defined OS_LINUX
/* Get address of CUserMessages instance */
char **userMsgClass = *reinterpret_cast<char ***>(vfunc + MSGCLASS2_OFFS);
/* Get address of CUserMessages::m_UserMessages */
dict = reinterpret_cast<UserMsgDict *>(*userMsgClass);
#endif
#ifdef OS_WIN32
} else if (UTIL_VerifySignature(vfunc, MSGCLASS3_SIG, MSGCLASS3_SIGLEN)) {
/* Get address of CUserMessages instance */
char **userMsgClass = *reinterpret_cast<char ***>(vfunc + MSGCLASS3_OFFS);
/* Get address of CUserMessages::m_UserMessages */
dict = reinterpret_cast<UserMsgDict *>(*userMsgClass);
#endif
}
if (dict)
{
m_MsgCount = dict->Count();
/* Ensure that count is within bounds of an unsigned byte, because that's what engine supports */
if (m_MsgCount < 0 || m_MsgCount > 255)
{
m_MsgCount = -1;
return false;
}
UserMessage *msg;
/* Cache messages in our CUtlDict */
for (int i = 0; i < m_MsgCount; i++)
{
msg = dict->Element(i);
m_UserMessages.Insert(msg->name, msg);
}
return true;
}
return false;
/* Jump back to setjmp() in CacheUserMessages() */
longjmp(usermsg_end, 1);
}
bool CSmmAPI::MsgCacheSuccessful()
/* IServerGameDLL::GetUserMessageInfo() crashes on games based on the old engine and
* early Orange Box. This is because Error() from tier0 gets called when a bad index is
* passed. This is all due to a bug in CUtlRBTree::IsValidIndex().
*
* So we detour Error() to fix this. Our detour then jumps back into CacheUserMessages()
* to a point before GetUserMessageInfo() is called. The detour is then removed and we
* exit.
*/
void CSmmAPI::CacheUserMessages()
{
return m_MsgCount > -1;
int q, size;
char buffer[256];
unsigned char *target, *detour;
unsigned char orig_bytes[5];
target = (unsigned char *)&Error;
detour = (unsigned char *)&Detour_Error;
/* Save bytes from target function */
memcpy(orig_bytes, target, sizeof(orig_bytes));
/* Patch in relative jump to our Error() detour */
SetMemAccess(target, sizeof(orig_bytes), SH_MEM_READ|SH_MEM_WRITE|SH_MEM_EXEC);
target[0] = IA32_JMP_IMM32;
*(int32_t *)&target[1] = (int32_t)(detour - (target + 5));
/* This is where longjmp() will end up */
if (setjmp(usermsg_end))
{
/* Restore bytes and memory protection */
memcpy(target, orig_bytes, sizeof(orig_bytes));
SetMemAccess(target, sizeof(orig_bytes), SH_MEM_READ|SH_MEM_EXEC);
return;
}
q = 0;
/* If GetUserMessageInfo() calls Error(), we should end up in our detour */
while (g_GameDll.pGameDLL->GetUserMessageInfo(q, buffer, sizeof(buffer), size))
{
usermsgs_list.push_back(UsrMsgInfo(size, buffer));
q++;
}
/* Jump back to setjmp() */
longjmp(usermsg_end, 1);
}
int CSmmAPI::GetUserMessageCount()
{
return m_MsgCount;
return (int)usermsgs_list.size();
}
int CSmmAPI::FindUserMessage(const char *name, int *size)
{
int index = m_UserMessages.Find(name);
if (size && index > -1)
for (size_t i = 0; i < usermsgs_list.size(); i++)
{
UserMessage *msg = m_UserMessages.Element(index);
*size = msg->size;
if (usermsgs_list[i].name.compare(name) == 0)
{
if (size)
{
*size = usermsgs_list[i].size;
}
return (int)i;
}
}
return index;
return -1;
}
const char *CSmmAPI::GetUserMessage(int index, int *size)
{
if (m_MsgCount <= 0 || index < 0 || index >= m_MsgCount)
if (index < 0 || index >= (int)usermsgs_list.size())
{
return NULL;
}
UserMessage *msg = m_UserMessages.Element(index);
if (size)
{
*size = msg->size;
*size = usermsgs_list[index].size;
}
return msg->name;
return usermsgs_list[index].name.c_str();
}
IServerPluginCallbacks *CSmmAPI::GetVSPInfo(int *pVersion)

17
core-legacy/CSmmAPI.h
View File

@ -1,5 +1,5 @@
/* ======== SourceMM ========
* Copyright (C) 2004-2008 Metamod:Source Development Team
* Copyright (C) 2004-2009 Metamod:Source Development Team
* No warranties of any kind
*
* License: zlib/libpng
@ -17,15 +17,6 @@
*/
#include "ISmmAPI.h"
#include <tier1/utldict.h>
struct UserMessage
{
int size;
const char *name;
};
typedef CUtlDict<UserMessage *, int> UserMsgDict;
typedef void (*CONPRINTF_FUNC)(const char *, ...);
@ -35,7 +26,6 @@ namespace SourceMM
{
public:
CSmmAPI();
~CSmmAPI();
public:
void LogMsg(ISmmPlugin *pl, const char *msg, ...);
public:
@ -80,15 +70,12 @@ namespace SourceMM
{
return m_VSP;
}
bool CacheUserMessages();
bool MsgCacheSuccessful();
void CacheUserMessages();
private:
META_RES m_Res;
CONPRINTF_FUNC m_ConPrintf;
bool m_CmdCache;
bool m_VSP;
int m_MsgCount;
UserMsgDict m_UserMessages;
};
};

29
core-legacy/concommands.cpp
View File

@ -176,29 +176,24 @@ CON_COMMAND(meta, "Metamod:Source Menu")
}
// Display user messages
if (g_SmmAPI.MsgCacheSuccessful())
const char *msgname;
int msgsize;
int msgcount = g_SmmAPI.GetUserMessageCount();
if (msgcount > 0)
{
const char *msgname;
int msgsize;
int msgcount = g_SmmAPI.GetUserMessageCount();
CONMSG(" User Messages: %-32.31s %-5s %-5s\n", "Name", "Index", "Size");
if (msgcount > 0)
for (int i = 0; i < msgcount; i++)
{
CONMSG(" User Messages: %-32.31s %-5s %-5s\n", "Name", "Index", "Size");
msgname = g_SmmAPI.GetUserMessage(i, &msgsize);
for (int i = 0; i < msgcount; i++)
{
msgname = g_SmmAPI.GetUserMessage(i, &msgsize);
CONMSG(" %-32.31s %-5d %-5d\n", msgname, i, msgsize);
}
CONMSG(" %d user message%s in total\n", msgcount, (msgcount > 1) ? "s" : "");
} else {
CONMSG(" User Messages: None\n");
CONMSG(" %-32.31s %-5d %-5d\n", msgname, i, msgsize);
}
CONMSG(" %d user message%s in total\n", msgcount, (msgcount > 1) ? "s" : "");
} else {
CONMSG(" User Messages: Failed to get list of user messages\n");
CONMSG(" User Messages: None\n");
}
return;

4
core-legacy/oslink.h
View File

@ -1,5 +1,5 @@
/* ======== SourceMM ========
* Copyright (C) 2004-2008 Metamod:Source Development Team
* Copyright (C) 2004-2009 Metamod:Source Development Team
* No warranties of any kind
*
* License: zlib/libpng
@ -75,6 +75,8 @@ bool GetFileOfAddress(void *pAddr, char *buffer, size_t maxlength);
#if defined __WIN32__ || defined _WIN32 || defined WIN32
typedef __int64 int64_t;
typedef unsigned __int64 uint64_t;
typedef __int32 int32_t;
typedef unsigned __int32 uint32_t;
#elif defined __GNUC__
#include <stdint.h>
#if !__GLIBC_HAVE_LONG_LONG

9
core-legacy/sourcemm.cpp
View File

@ -165,14 +165,7 @@ bool StartupMetamod(CreateInterfaceFn engineFactory, bool bWaitForGameInit)
LogMessage("[META] Warning: Console messages will not be redirected to rcon console.");
}
if (!g_SmmAPI.CacheUserMessages())
{
/* Don't know of a mod that has stripped out user messages completely,
* but perhaps should do something different here?
*/
LogMessage("[META] Warning: Failed to get list of user messages.");
LogMessage("[META] Warning: The 'meta game' command will not display user messages.");
}
g_SmmAPI.CacheUserMessages();
baseFs = (IFileSystem *)((engineFactory)(FILESYSTEM_INTERFACE_VERSION, NULL));
if (baseFs == NULL)

29
core/metamod_console.cpp
View File

@ -126,33 +126,26 @@ bool Command_Meta(IMetamodSourceCommandInfo *info)
#endif
// Display user messages
const char *msgname;
int msgsize;
int messages = g_Metamod.GetUserMessageCount();
if (messages != -1)
if (messages > 0)
{
const char *msgname;
int msgsize;
CONMSG(" User Messages: %-32.31s %-5s %-5s\n", "Name", "Index", "Size");
if (messages > 0)
for (int i = 0; i < messages; i++)
{
CONMSG(" User Messages: %-32.31s %-5s %-5s\n", "Name", "Index", "Size");
msgname = g_Metamod.GetUserMessage(i, &msgsize);
for (int i = 0; i < messages; i++)
{
msgname = g_Metamod.GetUserMessage(i, &msgsize);
CONMSG(" %-32.31s %-5d %-5d\n", msgname, i, msgsize);
}
CONMSG(" %d user message%s in total\n", messages, (messages > 1) ? "s" : "");
}
else
{
CONMSG(" User Messages: None\n");
CONMSG(" %-32.31s %-5d %-5d\n", msgname, i, msgsize);
}
CONMSG(" %d user message%s in total\n", messages, (messages > 1) ? "s" : "");
}
else
{
CONMSG(" User Messages: Failed to get list of user messages\n");
CONMSG(" User Messages: None\n");
}
return true;

8
core/metamod_oslink.h
View File

@ -1,8 +1,8 @@
/**
* vim: set ts=4 :
* vim: set ts=4 sw=4 tw=99 noet :
* ======================================================
* Metamod:Source
* Copyright (C) 2004-2008 AlliedModders LLC and authors.
* Copyright (C) 2004-2009 AlliedModders LLC and authors.
* All rights reserved.
* ======================================================
*
@ -21,8 +21,6 @@
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*
* Version: $Id$
*/
#ifndef _INCLUDE_OSLINK_H
@ -95,6 +93,8 @@ bool GetFileOfAddress(void *pAddr, char *buffer, size_t maxlength);
#if defined __WIN32__ || defined _WIN32 || defined WIN32
typedef __int64 int64_t;
typedef unsigned __int64 uint64_t;
typedef __int32 int32_t;
typedef unsigned __int32 uint32_t;
#elif defined __GNUC__
#include <stdint.h>
#if !__GLIBC_HAVE_LONG_LONG

237
core/provider/provider_ep2.cpp
View File

@ -24,12 +24,12 @@
*/
#include <stdio.h>
#include <setjmp.h>
#include "../metamod_oslink.h"
#include <sourcehook.h>
#include <convar.h>
#include <eiface.h>
#include <tier0/icommandline.h>
#include <tier1/utldict.h>
#include <sh_vector.h>
#include <sh_string.h>
#include "../metamod_util.h"
@ -60,7 +60,8 @@ DLL_IMPORT ICommandLine *CommandLine();
#endif
/* Functions */
bool CacheUserMessages();
void CacheUserMessages();
void Detour_Error(const tchar *pMsg, ...);
#if SOURCE_ENGINE >= SE_ORANGEBOX
void ClientCommand(edict_t *pEdict, const CCommand &args);
void LocalCommand_Meta(const CCommand &args);
@ -71,10 +72,10 @@ void LocalCommand_Meta();
void _ServerCommand();
/* Variables */
static bool usermsgs_extracted = false;
static CVector<UsrMsgInfo> usermsgs_list;
static BaseProvider g_Ep1Provider;
static List<ConCommandBase *> conbases_unreg;
static CVector<UsrMsgInfo> usermsgs_list;
static jmp_buf usermsg_end;
ICvar *icvar = NULL;
IFileSystem *baseFs = NULL;
@ -90,22 +91,6 @@ SH_DECL_HOOK2_void(IServerGameClients, ClientCommand, SH_NOATTRIB, 0, edict_t *,
SH_DECL_HOOK1_void(IServerGameClients, ClientCommand, SH_NOATTRIB, 0, edict_t *);
#endif
bool AssumeUserMessages()
{
int q, size;
char buffer[256];
q = 0;
while (server->GetUserMessageInfo(q, buffer, sizeof(buffer), size))
{
usermsgs_list.push_back(UsrMsgInfo(size, buffer));
q++;
}
return true;
}
void BaseProvider::ConsolePrint(const char *str)
{
#if SOURCE_ENGINE >= SE_ORANGEBOX
@ -155,10 +140,7 @@ void BaseProvider::Notify_DLLInit_Pre(CreateInterfaceFn engineFactory,
g_SMConVarAccessor.RegisterConCommandBase(&meta_local_cmd);
if ((usermsgs_extracted = CacheUserMessages()) == false)
{
usermsgs_extracted = AssumeUserMessages();
}
CacheUserMessages();
#if SOURCE_ENGINE == SE_DARKMESSIAH
if (!g_SMConVarAccessor.InitConCommandBaseList())
@ -334,11 +316,6 @@ void BaseProvider::UnregisterConCommandBase(ConCommandBase *pCommand)
int BaseProvider::GetUserMessageCount()
{
if (!usermsgs_extracted)
{
return -1;
}
return (int)usermsgs_list.size();
}
@ -361,7 +338,7 @@ int BaseProvider::FindUserMessage(const char *name, int *size)
const char *BaseProvider::GetUserMessage(int index, int *size)
{
if (!usermsgs_extracted || index < 0 || index >= (int)usermsgs_list.size())
if (index < 0 || index >= (int)usermsgs_list.size())
{
return NULL;
}
@ -534,153 +511,59 @@ void ClientCommand(edict_t *pEdict)
RETURN_META(MRES_IGNORED);
}
//////////////////////////////////////////////////////////////////////
// EVEN MORE HACKS HERE! YOU HAVE BEEN WARNED! //
// Signatures necessary in finding the pointer to the CUtlDict that //
// stores user message information. //
// IServerGameDLL::GetUserMessageInfo() normally crashes with bad //
// message indices. This is our answer to it. Yuck! <:-( //
//////////////////////////////////////////////////////////////////////
#ifdef OS_WIN32
/* General Windows sig */
#define MSGCLASS_SIGLEN 7
#define MSGCLASS_SIG "\x8B\x0D\x2A\x2A\x2A\x2A\x56"
#define MSGCLASS_OFFS 2
/* Dystopia Windows hack */
#define MSGCLASS2_SIGLEN 16
#define MSGCLASS2_SIG "\x56\x8B\x74\x24\x2A\x85\xF6\x7C\x2A\x3B\x35\x2A\x2A\x2A\x2A\x7D"
#define MSGCLASS2_OFFS 11
/* Windows frame pointer sig */
#define MSGCLASS3_SIGLEN 18
#define MSGCLASS3_SIG "\x55\x8B\xEC\x51\x89\x2A\x2A\x8B\x2A\x2A\x50\x8B\x0D\x2A\x2A\x2A\x2A\xE8"
#define MSGCLASS3_OFFS 13
#elif defined OS_LINUX
/* No frame pointer sig */
#define MSGCLASS_SIGLEN 14
#define MSGCLASS_SIG "\x53\x83\xEC\x2A\x8B\x2A\x2A\x2A\xA1\x2A\x2A\x2A\x2A\x89"
#define MSGCLASS_OFFS 9
/* Frame pointer sig */
#define MSGCLASS2_SIGLEN 16
#define MSGCLASS2_SIG "\x55\x89\xE5\x53\x83\xEC\x2A\x8B\x2A\x2A\xA1\x2A\x2A\x2A\x2A\x89"
#define MSGCLASS2_OFFS 11
#endif
struct UserMessage
/* This only gets called if IServerGameDLL::GetUserMessageInfo() triggers it */
void Detour_Error(const tchar *pMsg, ...)
{
int size;
const char *name;
};
typedef CUtlDict<UserMessage *, int> UserMsgDict;
/* This is the ugliest function in all of MM:S */
bool CacheUserMessages()
{
UserMsgDict *dict = NULL;
/* Get address of original GetUserMessageInfo() */
char *vfunc = (char *)SH_GET_ORIG_VFNPTR_ENTRY(server, &IServerGameDLL::GetUserMessageInfo);
/* Oh dear, we have a relative jump on our hands
* PVK II on Windows made me do this, but I suppose it doesn't hurt to check this on Linux too...
*/
if (*vfunc == '\xE9')
{
/* Get address from displacement...
*
* Add 5 because it's relative to next instruction:
* Opcode <1 byte> + 32-bit displacement <4 bytes>
*/
vfunc += *reinterpret_cast<int *>(vfunc + 1) + 5;
}
if (UTIL_VerifySignature(vfunc, MSGCLASS_SIG, MSGCLASS_SIGLEN))
{
/* Get address of CUserMessages instance */
char **userMsgClass = *reinterpret_cast<char ***>(vfunc + MSGCLASS_OFFS);
/* Get address of CUserMessages::m_UserMessages */
dict = reinterpret_cast<UserMsgDict *>(*userMsgClass);
}
else if (UTIL_VerifySignature(vfunc, MSGCLASS2_SIG, MSGCLASS2_SIGLEN))
{
#ifdef OS_WIN32
/* If we get here, the code is possibly inlined like in Dystopia */
/* Get the address of the CUtlRBTree */
char *rbtree = *reinterpret_cast<char **>(vfunc + MSGCLASS2_OFFS);
/* CUtlDict should be 8 bytes before the CUtlRBTree (hacktacular!) */
dict = reinterpret_cast<UserMsgDict *>(rbtree - 8);
#elif defined OS_LINUX
/* Get address of CUserMessages instance */
char **userMsgClass = *reinterpret_cast<char ***>(vfunc + MSGCLASS2_OFFS);
/* Get address of CUserMessages::m_UserMessages */
dict = reinterpret_cast<UserMsgDict *>(*userMsgClass);
#endif
#ifdef OS_WIN32
}
else if (UTIL_VerifySignature(vfunc, MSGCLASS3_SIG, MSGCLASS3_SIGLEN))
{
/* Get address of CUserMessages instance */
char **userMsgClass = *reinterpret_cast<char ***>(vfunc + MSGCLASS3_OFFS);
/* Get address of CUserMessages::m_UserMessages */
dict = reinterpret_cast<UserMsgDict *>(*userMsgClass);
#endif
}
#if !defined OS_WIN32
if (dict == NULL)
{
char path[255];
if (GetFileOfAddress(vfunc, path, sizeof(path)))
{
void *handle = dlopen(path, RTLD_NOW);
if (handle != NULL)
{
void *addr = dlsym(handle, "usermessages");
if (addr == NULL)
{
dlclose(handle);
return false;
}
dict = (UserMsgDict *)*(void **)addr;
dlclose(handle);
}
}
}
#endif
if (dict != NULL)
{
int msg_count = dict->Count();
/* Ensure that count is within bounds of an unsigned byte, because that's what engine supports */
if (msg_count < 0 || msg_count > 255)
{
return false;
}
UserMessage *msg;
UsrMsgInfo u_msg;
/* Cache messages in our CUtlDict */
for (int i = 0; i < msg_count; i++)
{
msg = dict->Element(i);
u_msg.name = msg->name;
u_msg.size = msg->size;
usermsgs_list.push_back(u_msg);
}
return true;
}
return false;
/* Jump back to setjmp() in CacheUserMessages() */
longjmp(usermsg_end, 1);
}
#define IA32_JMP_IMM32 0xE9
/* IServerGameDLL::GetUserMessageInfo() crashes on games based on the old engine and
* early Orange Box. This is because Error() from tier0 gets called when a bad index is
* passed. This is all due to a bug in CUtlRBTree::IsValidIndex().
*
* So we detour Error() to fix this. Our detour then jumps back into CacheUserMessages()
* to a point before GetUserMessageInfo() is called. The detour is then removed and we
* exit.
*/
void CacheUserMessages()
{
int q, size;
char buffer[256];
unsigned char *target, *detour;
unsigned char orig_bytes[5];
target = (unsigned char *)&Error;
detour = (unsigned char *)&Detour_Error;
/* Save bytes from target function */
memcpy(orig_bytes, target, sizeof(orig_bytes));
/* Patch in relative jump to our Error() detour */
SetMemAccess(target, sizeof(orig_bytes), SH_MEM_READ|SH_MEM_WRITE|SH_MEM_EXEC);
target[0] = IA32_JMP_IMM32;
*(int32_t *)&target[1] = (int32_t)(detour - (target + 5));
/* This is where longjmp() will end up */
if (setjmp(usermsg_end))
{
/* Restore bytes and memory protection */
memcpy(target, orig_bytes, sizeof(orig_bytes));
SetMemAccess(target, sizeof(orig_bytes), SH_MEM_READ|SH_MEM_EXEC);
return;
}
q = 0;
/* If GetUserMessageInfo() calls Error(), we should end up in our detour */
while (server->GetUserMessageInfo(q, buffer, sizeof(buffer), size))
{
usermsgs_list.push_back(UsrMsgInfo(size, buffer));
q++;
}
/* Jump back to setjmp() */
longjmp(usermsg_end, 1);
}