| 0,0 → 1,70 |
|---|
| unit PatchU; |
| |
| interface |
| |
| type |
| pPatchEvent = ^TPatchEvent; |
| |
| // "Asm" opcode hack to patch an existing routine |
| TPatchEvent = packed record |
| Jump: Byte; |
| Offset: Integer; |
| end; |
| |
| TPatchMethod = class |
| private |
| PatchedMethod, OriginalMethod: TPatchEvent; |
| PatchPositionMethod: pPatchEvent; |
| FIsPatched: boolean; |
| public |
| property IsPatched: boolean read FIsPatched; |
| constructor Create(const aSource, aDestination: Pointer); |
| destructor Destroy; override; |
| procedure Restore; |
| procedure Hook; |
| end; |
| |
| implementation |
| |
| uses |
| Windows, Sysutils; |
| |
| { TPatchMethod } |
| |
| constructor TPatchMethod.Create(const aSource, aDestination: Pointer); |
| var |
| OldProtect: Cardinal; |
| begin |
| PatchPositionMethod := pPatchEvent(aSource); |
| OriginalMethod := PatchPositionMethod^; |
| PatchedMethod.Jump := $E9; |
| PatchedMethod.Offset := Integer(PByte(aDestination)) - Integer(PByte(PatchPositionMethod)) - SizeOf(TPatchEvent); |
| |
| if not VirtualProtect(PatchPositionMethod, SizeOf(TPatchEvent), PAGE_EXECUTE_READWRITE, OldProtect) then |
| RaiseLastOSError; |
| |
| Hook; |
| end; |
| |
| destructor TPatchMethod.Destroy; |
| begin |
| Restore; |
| inherited; |
| end; |
| |
| procedure TPatchMethod.Hook; |
| begin |
| if FIsPatched then Exit; |
| FIsPatched := true; |
| PatchPositionMethod^ := PatchedMethod; |
| end; |
| |
| procedure TPatchMethod.Restore; |
| begin |
| if not FIsPatched then Exit; |
| FIsPatched := false; |
| PatchPositionMethod^ := OriginalMethod; |
| end; |
| |
| end. |
| |