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Diffstat (limited to 'third_party/minhook/src/buffer.c')
| -rw-r--r-- | third_party/minhook/src/buffer.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/third_party/minhook/src/buffer.c b/third_party/minhook/src/buffer.c new file mode 100644 index 0000000..940df65 --- /dev/null +++ b/third_party/minhook/src/buffer.c @@ -0,0 +1,312 @@ +/* + * MinHook - The Minimalistic API Hooking Library for x64/x86 + * Copyright (C) 2009-2017 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. + */ + +#include <windows.h> +#include "buffer.h" + +// 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) + +// 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. +static 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; + } +} + +//------------------------------------------------------------------------- +#if defined(_M_X64) || defined(__x86_64__) +static LPVOID FindPrevFreeRegion(LPVOID pAddress, LPVOID pMinAddr, DWORD dwAllocationGranularity) +{ + ULONG_PTR tryAddr = (ULONG_PTR)pAddress; + + // Round down to the 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(mbi)) == 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 + +//------------------------------------------------------------------------- +#if defined(_M_X64) || defined(__x86_64__) +static LPVOID FindNextFreeRegion(LPVOID pAddress, LPVOID pMaxAddr, DWORD dwAllocationGranularity) +{ + ULONG_PTR tryAddr = (ULONG_PTR)pAddress; + + // Round down to the 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(mbi)) == 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; +#if defined(_M_X64) || defined(__x86_64__) + 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) + { +#if defined(_M_X64) || defined(__x86_64__) + // 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; + } + +#if defined(_M_X64) || defined(__x86_64__) + // 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(mi)); + + return (mi.State == MEM_COMMIT && (mi.Protect & PAGE_EXECUTE_FLAGS)); +} |