ds@1952: /**
ds@1952:  * vim: set ts=4 :
ds@1952:  * =============================================================================
ds@1952:  * SourceMod
ds@1952:  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
ds@1952:  * =============================================================================
ds@1952:  *
ds@1952:  * This program is free software; you can redistribute it and/or modify it under
ds@1952:  * the terms of the GNU General Public License, version 3.0, as published by the
ds@1952:  * Free Software Foundation.
ds@1952:  * 
ds@1952:  * This program is distributed in the hope that it will be useful, but WITHOUT
ds@1952:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
ds@1952:  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
ds@1952:  * details.
ds@1952:  *
ds@1952:  * You should have received a copy of the GNU General Public License along with
ds@1952:  * this program.  If not, see <http://www.gnu.org/licenses/>.
ds@1952:  *
ds@1952:  * As a special exception, AlliedModders LLC gives you permission to link the
ds@1952:  * code of this program (as well as its derivative works) to "Half-Life 2," the
ds@1952:  * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
ds@1952:  * by the Valve Corporation.  You must obey the GNU General Public License in
ds@1952:  * all respects for all other code used.  Additionally, AlliedModders LLC grants
ds@1952:  * this exception to all derivative works.  AlliedModders LLC defines further
ds@1952:  * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
ds@1952:  * or <http://www.sourcemod.net/license.php>.
ds@1952:  *
ds@1952:  * Version: $Id$
ds@1952:  */
ds@1952: 
ds@1952: #include "MemoryUtils.h"
ds@1952: #include "ShareSys.h"
ds@1952: #ifdef PLATFORM_LINUX
ds@1952: #include <string.h>
ds@1952: #include <elf.h>
ds@1952: #endif
ds@1952: 
ds@1952: MemoryUtils g_MemUtils;
ds@1952: 
ds@1952: #if 0
ds@1952: MemoryUtils::MemoryUtils()
ds@1952: {
ds@1952: #ifdef PLATFORM_WINDOWS
ds@1952: 
ds@1952: 	SYSTEM_INFO info;
ds@1952: 	GetSystemInfo(&info);
ds@1952: 
ds@1952: 	m_PageSize = info.dwPageSize;
ds@1952: 
ds@1952: #elif defined PLATFORM_POSIX
ds@1952: 
ds@1952: 	m_PageSize = sysconf(_SC_PAGE_SIZE);
ds@1952: 
ds@1952: #endif
ds@1952: }
ds@1952: #endif
ds@1952: 
ds@1952: void MemoryUtils::OnSourceModAllInitialized()
ds@1952: {
ds@1952: 	g_ShareSys.AddInterface(NULL, this);
ds@1952: }
ds@1952: 
ds@1952: void *MemoryUtils::FindPattern(const void *libPtr, const char *pattern, size_t len)
ds@1952: {
ds@1952: 	DynLibInfo lib;
ds@1952: 	bool found;
ds@1952: 	char *ptr, *end;
ds@1952: 
ds@1952: 	memset(&lib, 0, sizeof(DynLibInfo));
ds@1952: 
ds@1952: 	if (!GetLibraryInfo(libPtr, lib))
ds@1952: 	{
ds@1952: 		return NULL;
ds@1952: 	}
ds@1952: 
ds@1952: 	ptr = reinterpret_cast<char *>(lib.baseAddress);
ds@1952: 	end = ptr + lib.memorySize;
ds@1952: 
ds@1952: 	while (ptr < end)
ds@1952: 	{
ds@1952: 		found = true;
ds@1952: 		for (register size_t i = 0; i < len; i++)
ds@1952: 		{
ds@1952: 			if (pattern[i] != '\x2A' && pattern[i] != ptr[i])
ds@1952: 			{
ds@1952: 				found = false;
ds@1952: 				break;
ds@1952: 			}
ds@1952: 		}
ds@1952: 
ds@1952: 		if (found)
ds@1952: 			return ptr;
ds@1952: 
ds@1952: 		ptr++;
ds@1952: 	}
ds@1952: 
ds@1952: 	return NULL;
ds@1952: }
ds@1952: 
ds@1952: bool MemoryUtils::GetLibraryInfo(const void *libPtr, DynLibInfo &lib)
ds@1952: {
ds@1952: 	unsigned long baseAddr;
ds@1952: 
ds@1952: 	if (libPtr == NULL)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: #ifdef PLATFORM_WINDOWS
ds@1952: 
ds@1952: 	MEMORY_BASIC_INFORMATION info;
ds@1952: 	IMAGE_DOS_HEADER *dos;
ds@1952: 	IMAGE_NT_HEADERS *pe;
ds@1952: 	IMAGE_FILE_HEADER *file;
ds@1952: 	IMAGE_OPTIONAL_HEADER *opt;
ds@1952: 
ds@1952: 	if (!VirtualQuery(libPtr, &info, sizeof(MEMORY_BASIC_INFORMATION)))
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	baseAddr = reinterpret_cast<unsigned long>(info.AllocationBase);
ds@1952: 
ds@1952: 	/* All this is for our insane sanity checks :o */
ds@1952: 	dos = reinterpret_cast<IMAGE_DOS_HEADER *>(baseAddr);
ds@1952: 	pe = reinterpret_cast<IMAGE_NT_HEADERS *>(baseAddr + dos->e_lfanew);
ds@1952: 	file = &pe->FileHeader;
ds@1952: 	opt = &pe->OptionalHeader;
ds@1952: 
ds@1952: 	/* Check PE magic and signature */
ds@1952: 	if (dos->e_magic != IMAGE_DOS_SIGNATURE || pe->Signature != IMAGE_NT_SIGNATURE || opt->Magic != IMAGE_NT_OPTIONAL_HDR32_MAGIC)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	/* Check architecture, which is 32-bit/x86 right now
ds@1952: 	 * Should change this for 64-bit if Valve gets their act together
ds@1952: 	 */
ds@1952: 	if (file->Machine != IMAGE_FILE_MACHINE_I386)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	/* For our purposes, this must be a dynamic library */
ds@1952: 	if ((file->Characteristics & IMAGE_FILE_DLL) == 0)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	/* Finally, we can do this */
ds@1952: 	lib.memorySize = opt->SizeOfImage;
ds@1952: 
ds@1952: #elif defined PLATFORM_LINUX
ds@1952: 
ds@1952: 	Dl_info info;
ds@1952: 	Elf32_Ehdr *file;
ds@1952: 	Elf32_Phdr *phdr;
ds@1952: 	uint16_t phdrCount;
ds@1952: 
ds@1952: 	if (!dladdr(libPtr, &info))
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	if (!info.dli_fbase || !info.dli_fname)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	/* This is for our insane sanity checks :o */
ds@1952: 	baseAddr = reinterpret_cast<unsigned long>(info.dli_fbase);
ds@1952: 	file = reinterpret_cast<Elf32_Ehdr *>(baseAddr);
ds@1952: 
ds@1952: 	/* Check ELF magic */
ds@1952: 	if (memcmp(ELFMAG, file->e_ident, SELFMAG) != 0)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	/* Check ELF version */
ds@1952: 	if (file->e_ident[EI_VERSION] != EV_CURRENT)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	/* Check ELF architecture, which is 32-bit/x86 right now
ds@1952: 	 * Should change this for 64-bit if Valve gets their act together
ds@1952: 	 */
ds@1952: 	if (file->e_ident[EI_CLASS] != ELFCLASS32 || file->e_machine != EM_386 || file->e_ident[EI_DATA] != ELFDATA2LSB)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	/* For our purposes, this must be a dynamic library/shared object */
ds@1952: 	if (file->e_type != ET_DYN)
ds@1952: 	{
ds@1952: 		return false;
ds@1952: 	}
ds@1952: 
ds@1952: 	phdrCount = file->e_phnum;
ds@1952: 	phdr = reinterpret_cast<Elf32_Phdr *>(baseAddr + file->e_phoff);
ds@1952: 	
ds@1952: 	/* Add up the memory sizes of segments marked as PT_LOAD as those are the only ones that should be in memory */
ds@1952: 	for (uint16_t i = 0; i < phdrCount; i++)
ds@1952: 	{
ds@1952: 		Elf32_Phdr &hdr = phdr[i];
ds@1952: 
ds@1952: 		if (hdr.p_type == PT_LOAD)
ds@1952: 		{
ds@1952: 			lib.memorySize += hdr.p_memsz;
ds@1952: 		}
ds@1952: 	}
ds@1952: 
ds@1952: #endif
ds@1952: 
ds@1952: 	lib.baseAddress = reinterpret_cast<void *>(baseAddr);
ds@1952: 
ds@1952: 	return true;
ds@1952: }