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MinHook.inl
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/*
* MinHook - The Minimalistic API Hooking Library for x64/x86
* Copyright (C) 2009-2015 Tsuda Kageyu.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#if !(defined _M_IX86) && !(defined _M_X64)
#error MinHook supports only x86 and x64 systems.
#endif
#define STRICT
#define NOMINMAX
#define _WIN32_WINNT 0x0501
#include <windows.h>
#include <tlhelp32.h>
#include <limits.h>
#include <intrin.h>
// MinHook Error Codes.
typedef enum MH_STATUS
{
// Unknown error. Should not be returned.
MH_UNKNOWN = -1,
// Successful.
MH_OK = 0,
// MinHook is already initialized.
MH_ERROR_ALREADY_INITIALIZED,
// MinHook is not initialized yet, or already uninitialized.
MH_ERROR_NOT_INITIALIZED,
// The hook for the specified target function is already created.
MH_ERROR_ALREADY_CREATED,
// The hook for the specified target function is not created yet.
MH_ERROR_NOT_CREATED,
// The hook for the specified target function is already enabled.
MH_ERROR_ENABLED,
// The hook for the specified target function is not enabled yet, or already
// disabled.
MH_ERROR_DISABLED,
// The specified pointer is invalid. It points the address of non-allocated
// and/or non-executable region.
MH_ERROR_NOT_EXECUTABLE,
// The specified target function cannot be hooked.
MH_ERROR_UNSUPPORTED_FUNCTION,
// Failed to allocate memory.
MH_ERROR_MEMORY_ALLOC,
// Failed to change the memory protection.
MH_ERROR_MEMORY_PROTECT,
// The specified module is not loaded.
MH_ERROR_MODULE_NOT_FOUND,
// The specified function is not found.
MH_ERROR_FUNCTION_NOT_FOUND
}
MH_STATUS;
// Can be passed as a parameter to MH_EnableHook, MH_DisableHook,
// MH_QueueEnableHook or MH_QueueDisableHook.
#define MH_ALL_HOOKS NULL
#ifdef __cplusplus
extern "C" {
#endif
// Initialize the MinHook library. You must call this function EXACTLY ONCE
// at the beginning of your program.
MH_STATUS WINAPI MH_Initialize(VOID);
// Uninitialize the MinHook library. You must call this function EXACTLY
// ONCE at the end of your program.
MH_STATUS WINAPI MH_Uninitialize(VOID);
// Creates a Hook for the specified target function, in disabled state.
// Parameters:
// pTarget [in] A pointer to the target function, which will be
// overridden by the detour function.
// pDetour [in] A pointer to the detour function, which will override
// the target function.
// ppOriginal [out] A pointer to the trampoline function, which will be
// used to call the original target function.
// This parameter can be NULL.
MH_STATUS WINAPI MH_CreateHook(LPVOID pTarget, LPVOID pDetour, LPVOID *ppOriginal);
// Creates a Hook for the specified API function, in disabled state.
// Parameters:
// pszModule [in] A pointer to the loaded module name which contains the
// target function.
// pszTarget [in] A pointer to the target function name, which will be
// overridden by the detour function.
// pDetour [in] A pointer to the detour function, which will override
// the target function.
// ppOriginal [out] A pointer to the trampoline function, which will be
// used to call the original target function.
// This parameter can be NULL.
MH_STATUS WINAPI MH_CreateHookApi(
LPCWSTR pszModule, LPCSTR pszProcName, LPVOID pDetour, LPVOID *ppOriginal);
// Creates a Hook for the specified API function, in disabled state.
// Parameters:
// pszModule [in] A pointer to the loaded module name which contains the
// target function.
// pszTarget [in] A pointer to the target function name, which will be
// overridden by the detour function.
// pDetour [in] A pointer to the detour function, which will override
// the target function.
// ppOriginal [out] A pointer to the trampoline function, which will be
// used to call the original target function.
// This parameter can be NULL.
// ppTarget [out] A pointer to the target function, which will be used
// with other functions.
// This parameter can be NULL.
MH_STATUS WINAPI MH_CreateHookApiEx(
LPCWSTR pszModule, LPCSTR pszProcName, LPVOID pDetour, LPVOID *ppOriginal, LPVOID *ppTarget);
// Removes an already created hook.
// Parameters:
// pTarget [in] A pointer to the target function.
MH_STATUS WINAPI MH_RemoveHook(LPVOID pTarget);
// Enables an already created hook.
// Parameters:
// pTarget [in] A pointer to the target function.
// If this parameter is MH_ALL_HOOKS, all created hooks are
// enabled in one go.
MH_STATUS WINAPI MH_EnableHook(LPVOID pTarget);
// Disables an already created hook.
// Parameters:
// pTarget [in] A pointer to the target function.
// If this parameter is MH_ALL_HOOKS, all created hooks are
// disabled in one go.
MH_STATUS WINAPI MH_DisableHook(LPVOID pTarget);
// Queues to enable an already created hook.
// Parameters:
// pTarget [in] A pointer to the target function.
// If this parameter is MH_ALL_HOOKS, all created hooks are
// queued to be enabled.
MH_STATUS WINAPI MH_QueueEnableHook(LPVOID pTarget);
// Queues to disable an already created hook.
// Parameters:
// pTarget [in] A pointer to the target function.
// If this parameter is MH_ALL_HOOKS, all created hooks are
// queued to be disabled.
MH_STATUS WINAPI MH_QueueDisableHook(LPVOID pTarget);
// Applies all queued changes in one go.
MH_STATUS WINAPI MH_ApplyQueued(VOID);
// Translates the MH_STATUS to its name as a string.
const char * WINAPI MH_StatusToString(MH_STATUS status);
#ifdef __cplusplus
}
#endif
#ifdef __cplusplus
extern "C" {
#endif
/*
* Hacker Disassembler Engine 32
* Copyright (c) 2006-2009, Vyacheslav Patkov.
* All rights reserved.
*/
// Size of each memory slot.
#ifdef _M_X64
#define MEMORY_SLOT_SIZE 64
#else
#define MEMORY_SLOT_SIZE 32
#endif
VOID InitializeBuffer(VOID);
VOID UninitializeBuffer(VOID);
LPVOID AllocateBuffer(LPVOID pOrigin);
VOID FreeBuffer(LPVOID pBuffer);
BOOL IsExecutableAddress(LPVOID pAddress);
BOOL IsReadableAddress(LPVOID pAddress);
// Size of each memory block. (= page size of VirtualAlloc)
#define MEMORY_BLOCK_SIZE 0x1000
// Max range for seeking a memory block. (= 1024MB)
#define MAX_MEMORY_RANGE 0x40000000
// Memory protection flags to check the executable address.
#define PAGE_EXECUTE_FLAGS (PAGE_EXECUTE | PAGE_EXECUTE_READ | PAGE_EXECUTE_READWRITE | PAGE_EXECUTE_WRITECOPY)
#define PAGE_READABLE_FLAGS (PAGE_READONLY | PAGE_READWRITE | PAGE_EXECUTE_READ | PAGE_EXECUTE_READWRITE)
// Memory slot.
typedef struct _MEMORY_SLOT
{
union
{
struct _MEMORY_SLOT *pNext;
UINT8 buffer[MEMORY_SLOT_SIZE];
};
} MEMORY_SLOT, *PMEMORY_SLOT;
// Memory block info. Placed at the head of each block.
typedef struct _MEMORY_BLOCK
{
struct _MEMORY_BLOCK *pNext;
PMEMORY_SLOT pFree; // First element of the free slot list.
UINT usedCount;
} MEMORY_BLOCK, *PMEMORY_BLOCK;
//-------------------------------------------------------------------------
// Global Variables:
//-------------------------------------------------------------------------
// First element of the memory block list.
PMEMORY_BLOCK g_pMemoryBlocks;
//-------------------------------------------------------------------------
VOID InitializeBuffer(VOID)
{
// Nothing to do for now.
}
//-------------------------------------------------------------------------
VOID UninitializeBuffer(VOID)
{
PMEMORY_BLOCK pBlock = g_pMemoryBlocks;
g_pMemoryBlocks = NULL;
while (pBlock)
{
PMEMORY_BLOCK pNext = pBlock->pNext;
VirtualFree(pBlock, 0, MEM_RELEASE);
pBlock = pNext;
}
}
//-------------------------------------------------------------------------
#ifdef _M_X64
static LPVOID FindPrevFreeRegion(LPVOID pAddress, LPVOID pMinAddr, DWORD dwAllocationGranularity)
{
ULONG_PTR tryAddr = (ULONG_PTR)pAddress;
// Round down to the next allocation granularity.
tryAddr -= tryAddr % dwAllocationGranularity;
// Start from the previous allocation granularity multiply.
tryAddr -= dwAllocationGranularity;
while (tryAddr >= (ULONG_PTR)pMinAddr)
{
MEMORY_BASIC_INFORMATION mbi;
if (VirtualQuery((LPVOID)tryAddr, &mbi, sizeof(MEMORY_BASIC_INFORMATION)) == 0)
break;
if (mbi.State == MEM_FREE)
return (LPVOID)tryAddr;
if ((ULONG_PTR)mbi.AllocationBase < dwAllocationGranularity)
break;
tryAddr = (ULONG_PTR)mbi.AllocationBase - dwAllocationGranularity;
}
return NULL;
}
#endif
//-------------------------------------------------------------------------
#ifdef _M_X64
static LPVOID FindNextFreeRegion(LPVOID pAddress, LPVOID pMaxAddr, DWORD dwAllocationGranularity)
{
ULONG_PTR tryAddr = (ULONG_PTR)pAddress;
// Round down to the next allocation granularity.
tryAddr -= tryAddr % dwAllocationGranularity;
// Start from the next allocation granularity multiply.
tryAddr += dwAllocationGranularity;
while (tryAddr <= (ULONG_PTR)pMaxAddr)
{
MEMORY_BASIC_INFORMATION mbi;
if (VirtualQuery((LPVOID)tryAddr, &mbi, sizeof(MEMORY_BASIC_INFORMATION)) == 0)
break;
if (mbi.State == MEM_FREE)
return (LPVOID)tryAddr;
tryAddr = (ULONG_PTR)mbi.BaseAddress + mbi.RegionSize;
// Round up to the next allocation granularity.
tryAddr += dwAllocationGranularity - 1;
tryAddr -= tryAddr % dwAllocationGranularity;
}
return NULL;
}
#endif
//-------------------------------------------------------------------------
static PMEMORY_BLOCK GetMemoryBlock(LPVOID pOrigin)
{
PMEMORY_BLOCK pBlock;
#ifdef _M_X64
ULONG_PTR minAddr;
ULONG_PTR maxAddr;
SYSTEM_INFO si;
GetSystemInfo(&si);
minAddr = (ULONG_PTR)si.lpMinimumApplicationAddress;
maxAddr = (ULONG_PTR)si.lpMaximumApplicationAddress;
// pOrigin } 512MB
if ((ULONG_PTR)pOrigin > MAX_MEMORY_RANGE && minAddr < (ULONG_PTR)pOrigin - MAX_MEMORY_RANGE)
minAddr = (ULONG_PTR)pOrigin - MAX_MEMORY_RANGE;
if (maxAddr > (ULONG_PTR)pOrigin + MAX_MEMORY_RANGE)
maxAddr = (ULONG_PTR)pOrigin + MAX_MEMORY_RANGE;
// Make room for MEMORY_BLOCK_SIZE bytes.
maxAddr -= MEMORY_BLOCK_SIZE - 1;
#endif
// Look the registered blocks for a reachable one.
for (pBlock = g_pMemoryBlocks; pBlock != NULL; pBlock = pBlock->pNext)
{
#ifdef _M_X64
// Ignore the blocks too far.
if ((ULONG_PTR)pBlock < minAddr || (ULONG_PTR)pBlock >= maxAddr)
continue;
#endif
// The block has at least one unused slot.
if (pBlock->pFree != NULL)
return pBlock;
}
#ifdef _M_X64
// Alloc a new block above if not found.
{
LPVOID pAlloc = pOrigin;
while ((ULONG_PTR)pAlloc >= minAddr)
{
pAlloc = FindPrevFreeRegion(pAlloc, (LPVOID)minAddr, si.dwAllocationGranularity);
if (pAlloc == NULL)
break;
pBlock = (PMEMORY_BLOCK)VirtualAlloc(
pAlloc, MEMORY_BLOCK_SIZE, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
if (pBlock != NULL)
break;
}
}
// Alloc a new block below if not found.
if (pBlock == NULL)
{
LPVOID pAlloc = pOrigin;
while ((ULONG_PTR)pAlloc <= maxAddr)
{
pAlloc = FindNextFreeRegion(pAlloc, (LPVOID)maxAddr, si.dwAllocationGranularity);
if (pAlloc == NULL)
break;
pBlock = (PMEMORY_BLOCK)VirtualAlloc(
pAlloc, MEMORY_BLOCK_SIZE, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
if (pBlock != NULL)
break;
}
}
#else
// In x86 mode, a memory block can be placed anywhere.
pBlock = (PMEMORY_BLOCK)VirtualAlloc(
NULL, MEMORY_BLOCK_SIZE, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
#endif
if (pBlock != NULL)
{
// Build a linked list of all the slots.
PMEMORY_SLOT pSlot = (PMEMORY_SLOT)pBlock + 1;
pBlock->pFree = NULL;
pBlock->usedCount = 0;
do
{
pSlot->pNext = pBlock->pFree;
pBlock->pFree = pSlot;
pSlot++;
} while ((ULONG_PTR)pSlot - (ULONG_PTR)pBlock <= MEMORY_BLOCK_SIZE - MEMORY_SLOT_SIZE);
pBlock->pNext = g_pMemoryBlocks;
g_pMemoryBlocks = pBlock;
}
return pBlock;
}
//-------------------------------------------------------------------------
LPVOID AllocateBuffer(LPVOID pOrigin)
{
PMEMORY_SLOT pSlot;
PMEMORY_BLOCK pBlock = GetMemoryBlock(pOrigin);
if (pBlock == NULL)
return NULL;
// Remove an unused slot from the list.
pSlot = pBlock->pFree;
pBlock->pFree = pSlot->pNext;
pBlock->usedCount++;
#ifdef _DEBUG
// Fill the slot with INT3 for debugging.
memset(pSlot, 0xCC, sizeof(MEMORY_SLOT));
#endif
return pSlot;
}
//-------------------------------------------------------------------------
VOID FreeBuffer(LPVOID pBuffer)
{
PMEMORY_BLOCK pBlock = g_pMemoryBlocks;
PMEMORY_BLOCK pPrev = NULL;
ULONG_PTR pTargetBlock = ((ULONG_PTR)pBuffer / MEMORY_BLOCK_SIZE) * MEMORY_BLOCK_SIZE;
while (pBlock != NULL)
{
if ((ULONG_PTR)pBlock == pTargetBlock)
{
PMEMORY_SLOT pSlot = (PMEMORY_SLOT)pBuffer;
#ifdef _DEBUG
// Clear the released slot for debugging.
memset(pSlot, 0x00, sizeof(MEMORY_SLOT));
#endif
// Restore the released slot to the list.
pSlot->pNext = pBlock->pFree;
pBlock->pFree = pSlot;
pBlock->usedCount--;
// Free if unused.
if (pBlock->usedCount == 0)
{
if (pPrev)
pPrev->pNext = pBlock->pNext;
else
g_pMemoryBlocks = pBlock->pNext;
VirtualFree(pBlock, 0, MEM_RELEASE);
}
break;
}
pPrev = pBlock;
pBlock = pBlock->pNext;
}
}
//-------------------------------------------------------------------------
BOOL IsExecutableAddress(LPVOID pAddress)
{
MEMORY_BASIC_INFORMATION mi;
VirtualQuery(pAddress, &mi, sizeof(MEMORY_BASIC_INFORMATION));
return (mi.State == MEM_COMMIT && (mi.Protect & PAGE_EXECUTE_FLAGS));
}
BOOL IsReadableAddress(LPVOID pAddress)
{
MEMORY_BASIC_INFORMATION mi;
VirtualQuery(pAddress, &mi, sizeof(MEMORY_BASIC_INFORMATION));
return (mi.State == MEM_COMMIT && (mi.Protect & PAGE_READABLE_FLAGS) && !(mi.Protect & (PAGE_GUARD|PAGE_NOACCESS)));
}
#ifndef ARRAYSIZE
#define ARRAYSIZE(A) (sizeof(A)/sizeof((A)[0]))
#endif
// Initial capacity of the HOOK_ENTRY buffer.
#define INITIAL_HOOK_CAPACITY 32
// Initial capacity of the thread IDs buffer.
#define INITIAL_THREAD_CAPACITY 128
// Special hook position values.
#define INVALID_HOOK_POS UINT_MAX
#define ALL_HOOKS_POS UINT_MAX
// Freeze() action argument defines.
#define ACTION_DISABLE 0
#define ACTION_ENABLE 1
#define ACTION_APPLY_QUEUED 2
#define ACTION_NOIPACTION 3
// Thread access rights for suspending/resuming threads.
#define THREAD_ACCESS \
(THREAD_SUSPEND_RESUME | THREAD_GET_CONTEXT | THREAD_QUERY_INFORMATION | THREAD_SET_CONTEXT)
// Hook information.
typedef struct _HOOK_ENTRY
{
LPVOID pTarget; // Address of the target function.
LPVOID pDetour; // Address of the detour or relay function.
LPVOID pTrampoline; // Address of the trampoline function.
UINT8 backup[8]; // Original prologue of the target function.
UINT8 patchAbove : 1; // Uses the hot patch area.
UINT8 isEnabled : 1; // Enabled.
UINT8 queueEnable : 1; // Queued for enabling/disabling when != isEnabled.
UINT nIP : 4; // Count of the instruction boundaries.
UINT8 oldIPs[8]; // Instruction boundaries of the target function.
UINT8 newIPs[8]; // Instruction boundaries of the trampoline function.
} HOOK_ENTRY, *PHOOK_ENTRY;
// Suspended threads for Freeze()/Unfreeze().
typedef struct _FROZEN_THREADS
{
LPDWORD pItems; // Data heap
UINT capacity; // Size of allocated data heap, items
UINT size; // Actual number of data items
} FROZEN_THREADS, *PFROZEN_THREADS;
//-------------------------------------------------------------------------
// Global Variables:
//-------------------------------------------------------------------------
// Spin lock flag for EnterSpinLock()/LeaveSpinLock().
volatile LONG g_isLocked = FALSE;
// Private heap handle. If not NULL, this library is initialized.
HANDLE g_hHeap = NULL;
// Hook entries.
struct
{
PHOOK_ENTRY pItems; // Data heap
UINT capacity; // Size of allocated data heap, items
UINT size; // Actual number of data items
} g_hooks;
#pragma pack(push, 1)
// Structs for writing x86/x64 instructions.
// 8-bit relative jump.
typedef struct _JMP_REL_SHORT
{
UINT8 opcode; // EB xx: JMP +2+xx
UINT8 operand;
} JMP_REL_SHORT, *PJMP_REL_SHORT;
// 32-bit direct relative jump/call.
typedef struct _JMP_REL
{
UINT8 opcode; // E9/E8 xxxxxxxx: JMP/CALL +5+xxxxxxxx
UINT32 operand; // Relative destination address
} JMP_REL, *PJMP_REL, CALL_REL;
// 64-bit indirect absolute jump.
typedef struct _JMP_ABS
{
UINT8 opcode0; // FF25 00000000: JMP [+6]
UINT8 opcode1;
UINT32 dummy;
UINT64 address; // Absolute destination address
} JMP_ABS, *PJMP_ABS;
// 64-bit indirect absolute call.
typedef struct _CALL_ABS
{
UINT8 opcode0; // FF15 00000002: CALL [+6]
UINT8 opcode1;
UINT32 dummy0;
UINT8 dummy1; // EB 08: JMP +10
UINT8 dummy2;
UINT64 address; // Absolute destination address
} CALL_ABS;
// 32-bit direct relative conditional jumps.
typedef struct _JCC_REL
{
UINT8 opcode0; // 0F8* xxxxxxxx: J** +6+xxxxxxxx
UINT8 opcode1;
UINT32 operand; // Relative destination address
} JCC_REL;
// 64bit indirect absolute conditional jumps that x64 lacks.
typedef struct _JCC_ABS
{
UINT8 opcode; // 7* 0E: J** +16
UINT8 dummy0;
UINT8 dummy1; // FF25 00000000: JMP [+6]
UINT8 dummy2;
UINT32 dummy3;
UINT64 address; // Absolute destination address
} JCC_ABS;
#pragma pack(pop)
typedef struct _TRAMPOLINE
{
LPVOID pTarget; // [In] Address of the target function.
LPVOID pDetour; // [In] Address of the detour function.
LPVOID pTrampoline; // [In] Buffer address for the trampoline and relay function.
#ifdef _M_X64
LPVOID pRelay; // [Out] Address of the relay function.
#endif
BOOL patchAbove; // [Out] Should use the hot patch area?
UINT nIP; // [Out] Number of the instruction boundaries.
UINT8 oldIPs[8]; // [Out] Instruction boundaries of the target function.
UINT8 newIPs[8]; // [Out] Instruction boundaries of the trampoline function.
} TRAMPOLINE, *PTRAMPOLINE;
BOOL CreateTrampolineFunction(PTRAMPOLINE ct);
//-------------------------------------------------------------------------
// Returns INVALID_HOOK_POS if not found.
static UINT FindHookEntry(LPVOID pTarget)
{
UINT i;
for (i = 0; i < g_hooks.size; ++i)
{
if ((ULONG_PTR)pTarget == (ULONG_PTR)g_hooks.pItems[i].pTarget)
return i;
}
return INVALID_HOOK_POS;
}
//-------------------------------------------------------------------------
static PHOOK_ENTRY AddHookEntry()
{
if (g_hooks.pItems == NULL)
{
g_hooks.capacity = INITIAL_HOOK_CAPACITY;
g_hooks.pItems = (PHOOK_ENTRY)HeapAlloc(
g_hHeap, 0, g_hooks.capacity * sizeof(HOOK_ENTRY));
if (g_hooks.pItems == NULL)
return NULL;
}
else if (g_hooks.size >= g_hooks.capacity)
{
PHOOK_ENTRY p = (PHOOK_ENTRY)HeapReAlloc(
g_hHeap, 0, g_hooks.pItems, (g_hooks.capacity * 2) * sizeof(HOOK_ENTRY));
if (p == NULL)
return NULL;
g_hooks.capacity *= 2;
g_hooks.pItems = p;
}
return &g_hooks.pItems[g_hooks.size++];
}
//-------------------------------------------------------------------------
static void DeleteHookEntry(UINT pos)
{
if (pos < g_hooks.size - 1)
g_hooks.pItems[pos] = g_hooks.pItems[g_hooks.size - 1];
g_hooks.size--;
if (g_hooks.capacity / 2 >= INITIAL_HOOK_CAPACITY && g_hooks.capacity / 2 >= g_hooks.size)
{
PHOOK_ENTRY p = (PHOOK_ENTRY)HeapReAlloc(
g_hHeap, 0, g_hooks.pItems, (g_hooks.capacity / 2) * sizeof(HOOK_ENTRY));
if (p == NULL)
return;
g_hooks.capacity /= 2;
g_hooks.pItems = p;
}
}
//-------------------------------------------------------------------------
static DWORD_PTR FindOldIP(PHOOK_ENTRY pHook, DWORD_PTR ip)
{
UINT i;
if (pHook->patchAbove && ip == ((DWORD_PTR)pHook->pTarget - sizeof(JMP_REL)))
return (DWORD_PTR)pHook->pTarget;
for (i = 0; i < pHook->nIP; ++i)
{
if (ip == ((DWORD_PTR)pHook->pTrampoline + pHook->newIPs[i]))
return (DWORD_PTR)pHook->pTarget + pHook->oldIPs[i];
}
#ifdef _M_X64
// Check relay function.
if (ip == (DWORD_PTR)pHook->pDetour)
return (DWORD_PTR)pHook->pTarget;
#endif
return 0;
}
//-------------------------------------------------------------------------
static DWORD_PTR FindNewIP(PHOOK_ENTRY pHook, DWORD_PTR ip)
{
UINT i;
for (i = 0; i < pHook->nIP; ++i)
{
if (ip == ((DWORD_PTR)pHook->pTarget + pHook->oldIPs[i]))
return (DWORD_PTR)pHook->pTrampoline + pHook->newIPs[i];
}
return 0;
}
//-------------------------------------------------------------------------
static void ProcessThreadIPs(HANDLE hThread, UINT pos, UINT action)
{
// If the thread suspended in the overwritten area,
// move IP to the proper address.
CONTEXT c;
#ifdef _M_X64
DWORD64 *pIP = &c.Rip;
#else
DWORD *pIP = &c.Eip;
#endif
UINT count;
c.ContextFlags = CONTEXT_CONTROL;
if (!GetThreadContext(hThread, &c))
return;
if (pos == ALL_HOOKS_POS)
{
pos = 0;
count = g_hooks.size;
}
else
{
count = pos + 1;
}
for (; pos < count; ++pos)
{
PHOOK_ENTRY pHook = &g_hooks.pItems[pos];
BOOL enable;
DWORD_PTR ip;
switch (action)
{
case ACTION_DISABLE:
enable = FALSE;
break;
case ACTION_ENABLE:
enable = TRUE;
break;
case ACTION_APPLY_QUEUED:
enable = pHook->queueEnable;
break;
}
if (pHook->isEnabled == enable)
continue;
if (enable)
ip = FindNewIP(pHook, *pIP);
else
ip = FindOldIP(pHook, *pIP);
if (ip != 0)
{
*pIP = ip;
SetThreadContext(hThread, &c);
}
}
}
//-------------------------------------------------------------------------
static VOID EnumerateThreads(PFROZEN_THREADS pThreads)
{
HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
if (hSnapshot != INVALID_HANDLE_VALUE)
{
THREADENTRY32 te;
te.dwSize = sizeof(THREADENTRY32);
if (Thread32First(hSnapshot, &te))
{
do
{
if (te.dwSize >= (FIELD_OFFSET(THREADENTRY32, th32OwnerProcessID) + sizeof(DWORD))
&& te.th32OwnerProcessID == GetCurrentProcessId()
&& te.th32ThreadID != GetCurrentThreadId())
{
if (pThreads->pItems == NULL)
{
pThreads->capacity = INITIAL_THREAD_CAPACITY;
pThreads->pItems
= (LPDWORD)HeapAlloc(g_hHeap, 0, pThreads->capacity * sizeof(DWORD));
if (pThreads->pItems == NULL)
break;
}
else if (pThreads->size >= pThreads->capacity)
{
LPDWORD p = (LPDWORD)HeapReAlloc(
g_hHeap, 0, pThreads->pItems, (pThreads->capacity * 2) * sizeof(DWORD));
if (p == NULL)
break;
pThreads->capacity *= 2;
pThreads->pItems = p;
}
pThreads->pItems[pThreads->size++] = te.th32ThreadID;
}
te.dwSize = sizeof(THREADENTRY32);
} while (Thread32Next(hSnapshot, &te));
}
CloseHandle(hSnapshot);
}
}
//-------------------------------------------------------------------------
static VOID Freeze(PFROZEN_THREADS pThreads, UINT pos, UINT action)
{
pThreads->pItems = NULL;
pThreads->capacity = 0;
pThreads->size = 0;
EnumerateThreads(pThreads);
if (pThreads->pItems != NULL)
{
UINT i;
for (i = 0; i < pThreads->size; ++i)
{
HANDLE hThread = OpenThread(THREAD_ACCESS, FALSE, pThreads->pItems[i]);
if (hThread != NULL)
{
SuspendThread(hThread);
if (action != ACTION_NOIPACTION) ProcessThreadIPs(hThread, pos, action);
CloseHandle(hThread);
}
}
}
}
//-------------------------------------------------------------------------
static VOID Unfreeze(PFROZEN_THREADS pThreads)
{
if (pThreads->pItems != NULL)
{
UINT i;
for (i = 0; i < pThreads->size; ++i)
{
HANDLE hThread = OpenThread(THREAD_ACCESS, FALSE, pThreads->pItems[i]);
if (hThread != NULL)
{
ResumeThread(hThread);
CloseHandle(hThread);
}
}
HeapFree(g_hHeap, 0, pThreads->pItems);
}
}
//-------------------------------------------------------------------------
static MH_STATUS EnableHookLL(UINT pos, BOOL enable)
{
PHOOK_ENTRY pHook = &g_hooks.pItems[pos];
DWORD oldProtect;
SIZE_T patchSize = sizeof(JMP_REL);
LPBYTE pPatchTarget = (LPBYTE)pHook->pTarget;
if (pHook->patchAbove)
{
pPatchTarget -= sizeof(JMP_REL);
patchSize += sizeof(JMP_REL_SHORT);
}
if (!VirtualProtect(pPatchTarget, patchSize, PAGE_EXECUTE_READWRITE, &oldProtect))
return MH_ERROR_MEMORY_PROTECT;
if (enable)
{
PJMP_REL pJmp = (PJMP_REL)pPatchTarget;
pJmp->opcode = 0xE9;
pJmp->operand = (UINT32)((LPBYTE)pHook->pDetour - (pPatchTarget + sizeof(JMP_REL)));
if (pHook->patchAbove)
{
PJMP_REL_SHORT pShortJmp = (PJMP_REL_SHORT)pHook->pTarget;
pShortJmp->opcode = 0xEB;
pShortJmp->operand = (UINT8)(0 - (sizeof(JMP_REL_SHORT) + sizeof(JMP_REL)));
}
}
else
{
if (pHook->patchAbove)
memcpy(pPatchTarget, pHook->backup, sizeof(JMP_REL) + sizeof(JMP_REL_SHORT));
else
memcpy(pPatchTarget, pHook->backup, sizeof(JMP_REL));
}
VirtualProtect(pPatchTarget, patchSize, oldProtect, &oldProtect);
// Just-in-case measure.
FlushInstructionCache(GetCurrentProcess(), pPatchTarget, patchSize);
pHook->isEnabled = enable;
pHook->queueEnable = enable;
return MH_OK;
}
//-------------------------------------------------------------------------
static MH_STATUS EnableAllHooksLL(BOOL enable)
{
MH_STATUS status = MH_OK;
UINT i, first = INVALID_HOOK_POS;
for (i = 0; i < g_hooks.size; ++i)
{
if (g_hooks.pItems[i].isEnabled != enable)
{
first = i;
break;
}
}
if (first != INVALID_HOOK_POS)
{
FROZEN_THREADS threads;
Freeze(&threads, ALL_HOOKS_POS, enable ? ACTION_ENABLE : ACTION_DISABLE);
for (i = first; i < g_hooks.size; ++i)
{
if (g_hooks.pItems[i].isEnabled != enable)
{
status = EnableHookLL(i, enable);
if (status != MH_OK)
break;
}
}
Unfreeze(&threads);
}
return status;
}
//-------------------------------------------------------------------------
static VOID EnterSpinLock(VOID)
{
SIZE_T spinCount = 0;
// Wait until the flag is FALSE.
while (InterlockedCompareExchange(&g_isLocked, TRUE, FALSE) != FALSE)
{
// No need to generate a memory barrier here, since InterlockedCompareExchange()
// generates a full memory barrier itself.
// Prevent the loop from being too busy.
if (spinCount < 32)
Sleep(0);
else
Sleep(1);
spinCount++;
}
}