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Big critical hits cleanup. Cleaner, easier to maintain, uses less memory and should be much less likely to cause crashes when valve change things on me.

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--HG--
extra : convert_revision : svn%3A39bc706e-5318-0410-9160-8a85361fbb7c/trunk%402317
This commit is contained in:
Matt Woodrow
2008-07-01 09:04:00 +00:00
parent b01dd0798c
commit d530d0c726
12 changed files with 1013 additions and 486 deletions
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extensions/tf2/asm/asm.c
+329
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#include "asm.h"
//if dest is NULL, returns minimum number of bytes needed to be copied
//if dest is not NULL, it will copy the bytes to dest as well as fix CALLs and JMPs
//http://www.devmaster.net/forums/showthread.php?t=2311
int copy_bytes(unsigned char *func, unsigned char* dest, int required_len) {
int bytecount = 0;
while(bytecount < required_len && *func != 0xCC)
{
// prefixes F0h, F2h, F3h, 66h, 67h, D8h-DFh, 2Eh, 36h, 3Eh, 26h, 64h and 65h
int operandSize = 4;
int FPU = 0;
int twoByte = 0;
unsigned char opcode = 0x90;
unsigned char modRM = 0xFF;
while(*func == 0xF0 ||
*func == 0xF2 ||
*func == 0xF3 ||
(*func & 0xFC) == 0x64 ||
(*func & 0xF8) == 0xD8 ||
(*func & 0x7E) == 0x62)
{
if(*func == 0x66)
{
operandSize = 2;
}
else if((*func & 0xF8) == 0xD8)
{
FPU = *func;
if (dest)
*dest++ = *func++;
else
func++;
bytecount++;
break;
}
if (dest)
*dest++ = *func++;
else
func++;
bytecount++;
}
// two-byte opcode byte
if(*func == 0x0F)
{
twoByte = 1;
if (dest)
*dest++ = *func++;
else
func++;
bytecount++;
}
// opcode byte
opcode = *func++;
if (dest) *dest++ = opcode;
bytecount++;
// mod R/M byte
modRM = 0xFF;
if(FPU)
{
if((opcode & 0xC0) != 0xC0)
{
modRM = opcode;
}
}
else if(!twoByte)
{
if((opcode & 0xC4) == 0x00 ||
(opcode & 0xF4) == 0x60 && ((opcode & 0x0A) == 0x02 || (opcode & 0x09) == 0x09) ||
(opcode & 0xF0) == 0x80 ||
(opcode & 0xF8) == 0xC0 && (opcode & 0x0E) != 0x02 ||
(opcode & 0xFC) == 0xD0 ||
(opcode & 0xF6) == 0xF6)
{
modRM = *func++;
if (dest) *dest++ = modRM;
bytecount++;
}
}
else
{
if((opcode & 0xF0) == 0x00 && (opcode & 0x0F) >= 0x04 && (opcode & 0x0D) != 0x0D ||
(opcode & 0xF0) == 0x30 ||
opcode == 0x77 ||
(opcode & 0xF0) == 0x80 ||
(opcode & 0xF0) == 0xA0 && (opcode & 0x07) <= 0x02 ||
(opcode & 0xF8) == 0xC8)
{
// No mod R/M byte
}
else
{
modRM = *func++;
if (dest) *dest++ = modRM;
bytecount++;
}
}
// SIB
if((modRM & 0x07) == 0x04 &&
(modRM & 0xC0) != 0xC0)
{
if (dest)
*dest++ = *func++; //SIB
else
func++;
bytecount++;
}
// mod R/M displacement
// Dword displacement, no base
if((modRM & 0xC5) == 0x05) {
if (dest) {
*(unsigned int*)dest = *(unsigned int*)func;
dest += 4;
}
func += 4;
bytecount += 4;
}
// Byte displacement
if((modRM & 0xC0) == 0x40) {
if (dest)
*dest++ = *func++;
else
func++;
bytecount++;
}
// Dword displacement
if((modRM & 0xC0) == 0x80) {
if (dest) {
*(unsigned int*)dest = *(unsigned int*)func;
dest += 4;
}
func += 4;
bytecount += 4;
}
// immediate
if(FPU)
{
// Can't have immediate operand
}
else if(!twoByte)
{
if((opcode & 0xC7) == 0x04 ||
(opcode & 0xFE) == 0x6A || // PUSH/POP/IMUL
(opcode & 0xF0) == 0x70 || // Jcc
opcode == 0x80 ||
opcode == 0x83 ||
(opcode & 0xFD) == 0xA0 || // MOV
opcode == 0xA8 || // TEST
(opcode & 0xF8) == 0xB0 || // MOV
(opcode & 0xFE) == 0xC0 || // RCL
opcode == 0xC6 || // MOV
opcode == 0xCD || // INT
(opcode & 0xFE) == 0xD4 || // AAD/AAM
(opcode & 0xF8) == 0xE0 || // LOOP/JCXZ
opcode == 0xEB ||
opcode == 0xF6 && (modRM & 0x30) == 0x00) // TEST
{
if (dest)
*dest++ = *func++;
else
func++;
bytecount++;
}
else if((opcode & 0xF7) == 0xC2) // RET
{
if (dest) {
*(unsigned short*)dest = *(unsigned short*)func;
dest += 2;
}
func += 2;
bytecount += 2;
}
else if((opcode & 0xFC) == 0x80 ||
(opcode & 0xC7) == 0x05 ||
(opcode & 0xF8) == 0xB8 ||
(opcode & 0xFE) == 0xE8 || // CALL/Jcc
(opcode & 0xFE) == 0x68 ||
(opcode & 0xFC) == 0xA0 ||
(opcode & 0xEE) == 0xA8 ||
opcode == 0xC7 ||
opcode == 0xF7 && (modRM & 0x30) == 0x00)
{
if (dest) {
//Fix CALL/JMP offset
if ((opcode & 0xFE) == 0xE8) {
if (operandSize == 4)
*(long*)dest = ((func + *(long*)func) - dest);
else
*(short*)dest = ((func + *(short*)func) - dest);
} else {
if (operandSize == 4)
*(unsigned long*)dest = *(unsigned long*)func;
else
*(unsigned short*)dest = *(unsigned short*)func;
}
dest += operandSize;
}
func += operandSize;
bytecount += operandSize;
}
}
else
{
if(opcode == 0xBA || // BT
opcode == 0x0F || // 3DNow!
(opcode & 0xFC) == 0x70 || // PSLLW
(opcode & 0xF7) == 0xA4 || // SHLD
opcode == 0xC2 ||
opcode == 0xC4 ||
opcode == 0xC5 ||
opcode == 0xC6)
{
if (dest)
*dest++ = *func++;
else
func++;
}
else if((opcode & 0xF0) == 0x80) // Jcc -i
{
if (dest) {
if (operandSize == 4)
*(unsigned long*)dest = *(unsigned long*)func;
else
*(unsigned short*)dest = *(unsigned short*)func;
dest += operandSize;
}
func += operandSize;
bytecount += operandSize;
}
}
}
return bytecount;
}
//insert a specific JMP instruction at the given location
void inject_jmp(void* src, void* dest) {
*(unsigned char*)src = OP_JMP;
*(long*)((unsigned char*)src+1) = (long)((unsigned char*)dest - ((unsigned char*)src + OP_JMP_SIZE));
}
//fill a given block with NOPs
void fill_nop(void* src, unsigned int len) {
unsigned char* src2 = (unsigned char*)src;
while (len) {
*src2++ = OP_NOP;
--len;
}
}
void* eval_jump(void* src) {
unsigned char* addr = (unsigned char*)src;
if (!addr) return 0;
//import table jump
if (addr[0] == OP_PREFIX && addr[1] == OP_JMP_SEG) {
addr += 2;
addr = *(unsigned char**)addr;
//TODO: if addr points into the IAT
return *(void**)addr;
}
//8bit offset
else if (addr[0] == OP_JMP_BYTE) {
addr = &addr[OP_JMP_BYTE_SIZE] + *(char*)&addr[1];
//mangled 32bit jump?
if (addr[0] = OP_JMP) {
addr = addr + *(int*)&addr[1];
}
return addr;
}
/*
//32bit offset
else if (addr[0] == OP_JMP) {
addr = &addr[OP_JMP_SIZE] + *(int*)&addr[1];
}
*/
return addr;
}
/*
from ms detours package
static bool detour_is_imported(PBYTE pbCode, PBYTE pbAddress)
{
MEMORY_BASIC_INFORMATION mbi;
VirtualQuery((PVOID)pbCode, &mbi, sizeof(mbi));
__try {
PIMAGE_DOS_HEADER pDosHeader = (PIMAGE_DOS_HEADER)mbi.AllocationBase;
if (pDosHeader->e_magic != IMAGE_DOS_SIGNATURE) {
return false;
}
PIMAGE_NT_HEADERS pNtHeader = (PIMAGE_NT_HEADERS)((PBYTE)pDosHeader +
pDosHeader->e_lfanew);
if (pNtHeader->Signature != IMAGE_NT_SIGNATURE) {
return false;
}
if (pbAddress >= ((PBYTE)pDosHeader +
pNtHeader->OptionalHeader
.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].VirtualAddress) &&
pbAddress < ((PBYTE)pDosHeader +
pNtHeader->OptionalHeader
.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].VirtualAddress +
pNtHeader->OptionalHeader
.DataDirectory[IMAGE_DIRECTORY_ENTRY_IAT].Size)) {
return true;
}
return false;
}
__except(EXCEPTION_EXECUTE_HANDLER) {
return false;
}
}
*/
extensions/tf2/asm/asm.h
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#ifndef __ASM_H__
#define __ASM_H__
#define OP_JMP 0xE9
#define OP_JMP_SIZE 5
#define OP_NOP 0x90
#define OP_NOP_SIZE 1
#define OP_PREFIX 0xFF
#define OP_JMP_SEG 0x25
#define OP_JMP_BYTE 0xEB
#define OP_JMP_BYTE_SIZE 2
#ifdef __cplusplus
extern "C" {
#endif
//if dest is NULL, returns minimum number of bytes needed to be copied
//if dest is not NULL, it will copy the bytes to dest as well as fix CALLs and JMPs
//http://www.devmaster.net/forums/showthread.php?t=2311
int copy_bytes(unsigned char *func, unsigned char* dest, int required_len);
//insert a specific JMP instruction at the given location
void inject_jmp(void* src, void* dest);
//fill a given block with NOPs
void fill_nop(void* src, unsigned int len);
//evaluate a JMP at the target
void* eval_jump(void* src);
#ifdef __cplusplus
}
#endif
#endif //__ASM_H__