sourcemod-central: extensions/sdktools/detours.h@ca3757e676f6

     1 /**

     2  * vim: set ts=4 :

     3  * =============================================================================

     4  * SourceMod SDKTools Extension

     5  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

     6  * =============================================================================

     7  *

     8  * This program is free software; you can redistribute it and/or modify it under

     9  * the terms of the GNU General Public License, version 3.0, as published by the

    10  * Free Software Foundation.

    11  *

    12  * This program is distributed in the hope that it will be useful, but WITHOUT

    13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

    14  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more

    15  * details.

    16  *

    17  * You should have received a copy of the GNU General Public License along with

    18  * this program.  If not, see <http://www.gnu.org/licenses/>.

    19  *

    20  * As a special exception, AlliedModders LLC gives you permission to link the

    21  * code of this program (as well as its derivative works) to "Half-Life 2," the

    22  * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

    23  * by the Valve Corporation.  You must obey the GNU General Public License in

    24  * all respects for all other code used.  Additionally, AlliedModders LLC grants

    25  * this exception to all derivative works.  AlliedModders LLC defines further

    26  * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

    27  * or <http://www.sourcemod.net/license.php>.

    28  *

    29  * Version: $Id$

    30  */

    32 #ifndef _INCLUDE_SOURCEMOD_DETOURS_H_

    33 #define _INCLUDE_SOURCEMOD_DETOURS_H_

    35 #if defined PLATFORM_LINUX

    36 #include <sys/mman.h>

    37 #define	PAGE_SIZE	4096

    38 #define ALIGN(ar) ((long)ar & ~(PAGE_SIZE-1))

    39 #define	PAGE_EXECUTE_READWRITE	PROT_READ|PROT_WRITE|PROT_EXEC

    40 #endif

    42 struct patch_t

    43 {

    44 	patch_t()

    45 	{

    46 		patch[0] = 0;

    47 		bytes = 0;

    48 	}

    49 	unsigned char patch[20];

    50 	size_t bytes;

    51 };

    53 inline void ProtectMemory(void *addr, int length, int prot)

    54 {

    55 #if defined PLATFORM_LINUX

    56 	void *addr2 = (void *)ALIGN(addr);

    57 	mprotect(addr2, sysconf(_SC_PAGESIZE), prot);

    58 #elif defined PLATFORM_WINDOWS

    59 	DWORD old_prot;

    60 	VirtualProtect(addr, length, prot, &old_prot);

    61 #endif

    62 }

    64 inline void SetMemPatchable(void *address, size_t size)

    65 {

    66 	ProtectMemory(address, (int)size, PAGE_EXECUTE_READWRITE);

    67 }

    69 inline void DoGatePatch(unsigned char *target, void *callback)

    70 {

    71 	SetMemPatchable(target, 20);

    73 	target[0] = 0xFF;	/* JMP */

    74 	target[1] = 0x25;	/* MEM32 */

    75 	*(void **)(&target[2]) = callback;

    76 }

    78 inline void ApplyPatch(void *address, int offset, const patch_t *patch, patch_t *restore)

    79 {

    80 	ProtectMemory(address, 20, PAGE_EXECUTE_READWRITE);

    82 	unsigned char *addr = (unsigned char *)address + offset;

    83 	if (restore)

    84 	{

    85 		for (size_t i=0; i<patch->bytes; i++)

    86 		{

    87 			restore->patch[i] = addr[i];

    88 		}

    89 		restore->bytes = patch->bytes;

    90 	}

    92 	for (size_t i=0; i<patch->bytes; i++)

    93 	{

    94 		addr[i] = patch->patch[i];

    95 	}

    96 }

    98 #endif //_INCLUDE_SOURCEMOD_DETOURS_H_

author	Matt Woodrow <pred@alliedmods.net>
	Sun Jul 06 03:30:06 2008 +0000 (2008-07-06)
changeset 2165	ca3757e676f6
parent 1990	de135d1f05b1
child 2471	194be299b700
permissions	-rw-r--r--