amxmodx/public/memtools/CDetour/detourhelpers.h

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/**
* vim: set ts=4 :
* =============================================================================
* SourceMod
* Copyright (C) 2004-2010 AlliedModders LLC. All rights reserved.
* =============================================================================
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 3.0, as published by the
* Free Software Foundation.
*
* This program 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
* this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, AlliedModders LLC gives you permission to link the
* code of this program (as well as its derivative works) to "Half-Life 2," the
* "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
* by the Valve Corporation. You must obey the GNU General Public License in
* all respects for all other code used. Additionally, AlliedModders LLC grants
* this exception to all derivative works. AlliedModders LLC defines further
* exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
* or <http://www.sourcemod.net/license.php>.
*
* Version: $Id: detourhelpers.h 248 2008-08-27 00:56:22Z pred $
*/
#ifndef _INCLUDE_SOURCEMOD_DETOURHELPERS_H_
#define _INCLUDE_SOURCEMOD_DETOURHELPERS_H_
#if defined(__linux__) || defined(__APPLE__)
#include <sys/mman.h>
#ifndef PAGE_SIZE
#define PAGE_SIZE 4096
#endif
#define ALIGN(ar) ((long)ar & ~(PAGE_SIZE-1))
#define PAGE_EXECUTE_READWRITE PROT_READ|PROT_WRITE|PROT_EXEC
#if defined(__linux)
#include <malloc.h>
#endif
#elif defined(WIN32)
#include <windows.h>
#endif
struct patch_t
{
patch_t()
{
patch[0] = 0;
bytes = 0;
}
unsigned char patch[20];
size_t bytes;
};
inline void ProtectMemory(void *addr, int length, int prot)
{
#if defined(__linux__) || defined(__APPLE__)
void *addr2 = (void *)ALIGN(addr);
mprotect(addr2, sysconf(_SC_PAGESIZE), prot);
#elif defined(WIN32)
DWORD old_prot;
VirtualProtect(addr, length, prot, &old_prot);
#endif
}
inline unsigned char *AllocatePageMemory(size_t size)
{
#if defined WIN32
return (unsigned char *)VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
#elif defined __GNUC__
#if defined __APPLE__
unsigned char *addr = (unsigned char *)valloc(size);
#else
unsigned char *addr = (unsigned char *)memalign(sysconf(_SC_PAGESIZE), size);
#endif
mprotect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC);
return addr;
#endif
}
inline void FreePageMemory(void *addr)
{
#if defined(WIN32)
VirtualFree(addr, 0, MEM_RELEASE);
#else
free(addr);
#endif
}
inline void SetMemPatchable(void *address, size_t size)
{
ProtectMemory(address, (int)size, PAGE_EXECUTE_READWRITE);
}
inline void DoGatePatch(unsigned char *target, void *callback)
{
SetMemPatchable(target, 20);
target[0] = 0xFF; /* JMP */
target[1] = 0x25; /* MEM32 */
*(void **)(&target[2]) = callback;
}
inline void ApplyPatch(void *address, int offset, const patch_t *patch, patch_t *restore)
{
ProtectMemory(address, 20, PAGE_EXECUTE_READWRITE);
unsigned char *addr = (unsigned char *)address + offset;
if (restore)
{
for (size_t i=0; i<patch->bytes; i++)
{
restore->patch[i] = addr[i];
}
restore->bytes = patch->bytes;
}
for (size_t i=0; i<patch->bytes; i++)
{
addr[i] = patch->patch[i];
}
}
#endif //_INCLUDE_SOURCEMOD_DETOURHELPERS_H_