/// <summary>
/// Initializes a new instance of the <see cref="AsmHook"/> class.
/// This is an assembly hook and should not be used for except under unique circumstances.
/// Hook is not activated until Enable() method is called.
/// </summary>
/// <param name="address">A memory address to install a hook.</param>
/// <param name="assembly">FASM syntax assembly code representing your hook. The first line should be use64.</param>
/// <param name="name">The name of what you are hooking, since a delegate is not required.</param>
/// <param name="asmHookBehaviour">How the hook is inserted into the execution flow.</param>
public AsmHook(IntPtr address, string[] assembly, string name, AsmHookBehaviour asmHookBehaviour = AsmHookBehaviour.ExecuteFirst)
{
address = HookManager.FollowJmp(address);
var hasOtherHooks = HookManager.Originals.ContainsKey(address);
if (!hasOtherHooks)
{
MemoryHelper.ReadRaw(address, 0x32, out var original);
HookManager.Originals[address] = original;
}
this.address = address;
this.hookImpl = ReloadedHooks.Instance.CreateAsmHook(assembly, address.ToInt64(), (Reloaded.Hooks.Definitions.Enums.AsmHookBehaviour)asmHookBehaviour);
this.statsMethod = new DynamicMethod(name, null, null);
this.statsMethod.GetILGenerator().Emit(OpCodes.Ret);
var dele = this.statsMethod.CreateDelegate(typeof(Action));
HookManager.TrackedHooks.Add(new HookInfo(this, dele, Assembly.GetCallingAssembly()));
}
/// <summary>
/// Creates a cheat engine style hook, replacing instruction(s) with a JMP to a user provided set of ASM instructions (and optionally the original ones).
/// </summary>
/// <param name="asmCode">The assembly code to execute, precompiled.</param>
/// <param name="functionAddress">The address of the function or mid-function to hook.</param>
/// <param name="behaviour">Defines what should be done with the original code that was replaced with the JMP instruction.</param>
/// <param name="hookLength">Optional explicit length of hook. Use only in rare cases where auto-length check overflows a jmp/call opcode.</param>
public AsmHook(byte[] asmCode, long functionAddress, AsmHookBehaviour behaviour = AsmHookBehaviour.ExecuteFirst, int hookLength = -1) : this()
{
/*
* === Hook Summary ===
*
* A. Backup Original Code & Generate Function Disable Stub
* A1. Find amount of bytes required to insert JMP opcode, backup original bytes.
* B2. Function disable stub will contain original code and jump back to end of hook.
*
* B. Generate Function Stub.
* B1. For stub, generate code combining asmCode and original instructions, depending on AsmHookBehaviour
* B2. Add jmp back to end of original hook.
*
* Graph:
* Original => Stub Entry (JMP To Hook or Original Copy) => Hook/Original Copy with JMP back.
*
* Notes: For hook disable, replace jmp address to function disable stub.
* For hook re-enable, replace jmp address to function hook stub.
*/
if (hookLength == -1)
{
hookLength = Utilities.GetHookLength((IntPtr)functionAddress, MaxJmpSize, _is64Bit);
}
CurrentProcess.SafeReadRaw((IntPtr)functionAddress, out byte[] originalFunction, hookLength);
long jumpBackAddress = functionAddress + hookLength;
/* Size calculations for buffer, must have sufficient space. */
// Stubs:
// Stub Entry => Stub Hook.
// Stub Hook => Caller.
// Disable.Original Stub => Caller.
int codeAlignment = 4; // Alignment of code in memory.
int numberOfStubs = 3; // Also number of allocations.
int alignmentRequiredBytes = (codeAlignment * numberOfStubs);
int stubEntrySize = MaxJmpSize;
int stubHookSize = asmCode.Length + hookLength + MaxJmpSize;
int stubOriginalSize = hookLength + MaxJmpSize;
int requiredSizeOfBuffer = stubEntrySize + stubHookSize + stubOriginalSize + alignmentRequiredBytes;
var buffer = Utilities.FindOrCreateBufferInRange(requiredSizeOfBuffer);
buffer.ExecuteWithLock(() =>
{
var patcher = new IcedPatcher(_is64Bit, originalFunction, (IntPtr)functionAddress);
// Make Hook and Original Stub
buffer.SetAlignment(codeAlignment);
IntPtr hookStubAddr = MakeHookStub(buffer, patcher, asmCode, originalFunction, jumpBackAddress, behaviour);
buffer.SetAlignment(codeAlignment);
IntPtr originalStubAddr = MakeOriginalStub(buffer, patcher, originalFunction, jumpBackAddress);
// Make Jump to Entry, Original Stub
byte[] jmpToOriginal = Utilities.AssembleAbsoluteJump(originalStubAddr, _is64Bit);
byte[] jmpToHook = Utilities.AssembleAbsoluteJump(hookStubAddr, _is64Bit);
// Make Entry Stub
IntPtr entryStubAddr = buffer.Add(jmpToHook, codeAlignment);
// Make Disable/Enable
_disableHookPatch = new Patch(entryStubAddr, jmpToOriginal);
_enableHookPatch = new Patch(entryStubAddr, jmpToHook);
// Make Hook Enabler
var jumpOpcodes = Utilities.AssembleAbsoluteJump(entryStubAddr, _is64Bit).ToList();
Utilities.FillArrayUntilSize <byte>(jumpOpcodes, 0x90, hookLength);
_activateHookPatch = new Patch((IntPtr)functionAddress, jumpOpcodes.ToArray());
return(true);
});
}
/// <summary>
/// Creates a cheat engine style hook, replacing instruction(s) with a JMP to a user provided set of ASM instructions (and optionally the original ones).
/// </summary>
/// <param name="asmCode">
/// The assembly code to execute, in FASM syntax.
/// (Should start with use32/use64)
/// </param>
/// <param name="functionAddress">The address of the function or mid-function to hook.</param>
/// <param name="behaviour">Defines what should be done with the original code that was replaced with the JMP instruction.</param>
/// <param name="hookLength">Optional explicit length of hook. Use only in rare cases where auto-length check overflows a jmp/call opcode.</param>
public AsmHook(string[] asmCode, long functionAddress, AsmHookBehaviour behaviour = AsmHookBehaviour.ExecuteFirst, int hookLength = -1) : this(Utilities.Assembler.Assemble(asmCode), functionAddress, behaviour, hookLength)
{
}
private IntPtr MakeHookStub(MemoryBuffer buffer, IcedPatcher patcher, byte[] asmCode, byte[] originalCode, long jumpBackAddress, AsmHookBehaviour behaviour)
{
var bytes = new List <byte>(asmCode.Length + originalCode.Length);
var jmpBackBytes = Utilities.AssembleAbsoluteJump((IntPtr)jumpBackAddress, _is64Bit);
switch (behaviour)
{
case AsmHookBehaviour.ExecuteFirst:
bytes.AddRange(asmCode);
bytes.AddRange(patcher.EncodeForNewAddress(buffer.Properties.WritePointer + bytes.Count));
break;
case AsmHookBehaviour.ExecuteAfter:
bytes.AddRange(patcher.EncodeForNewAddress(buffer.Properties.WritePointer + bytes.Count));
bytes.AddRange(asmCode);
break;
case AsmHookBehaviour.DoNotExecuteOriginal:
bytes.AddRange(asmCode);
break;
default:
throw new ArgumentOutOfRangeException(nameof(behaviour), behaviour, null);
}
bytes.AddRange(jmpBackBytes);
return(buffer.Add(bytes.ToArray(), 1)); // Buffer is pre-aligned
}
public IAsmHook CreateAsmHook(byte[] asmCode, long functionAddress, AsmHookBehaviour behaviour = AsmHookBehaviour.ExecuteFirst, int hookLength = -1) => new AsmHook(asmCode, functionAddress, behaviour, hookLength);
/// <inheritdoc />
public IAsmHook MakeAsmHook(byte[] asmCode, AsmHookBehaviour behaviour = AsmHookBehaviour.ExecuteFirst, int hookLength = -1)
{
return(Hooks.CreateAsmHook(asmCode, Address, behaviour, hookLength));
}
public IAsmHook CreateAsmHook(byte[] asmCode, long functionAddress, AsmHookBehaviour behaviour, int hookLength) => new AsmHook(asmCode, functionAddress, behaviour, hookLength);
public IAsmHook CreateAsmHook(byte[] asmCode, long functionAddress, AsmHookBehaviour behaviour) => CreateAsmHook(asmCode, functionAddress, behaviour, -1);
public IAsmHook MakeAsmHook(byte[] asmCode, AsmHookBehaviour behaviour = AsmHookBehaviour.ExecuteFirst, int hookLength = -1)
{
return(mFunction.MakeAsmHook(asmCode, behaviour, hookLength));
}
/// <summary>
/// Creates a cheat engine style hook, replacing instruction(s) with a JMP to a user provided set of ASM instructions (and optionally the original ones).
/// </summary>
/// <param name="asmCode">The assembly code to execute, precompiled.</param>
/// <param name="functionAddress">The address of the function or mid-function to hook.</param>
/// <param name="behaviour">Defines what should be done with the original code that was replaced with the JMP instruction.</param>
/// <param name="hookLength">Optional explicit length of hook. Use only in rare cases where auto-length check overflows a jmp/call opcode.</param>
public AsmHook(byte[] asmCode, long functionAddress, AsmHookBehaviour behaviour = AsmHookBehaviour.ExecuteFirst, int hookLength = -1) : this(asmCode, functionAddress,
new AsmHookOptions() { Behaviour = behaviour, hookLength = hookLength })
{
}
/// <summary>
/// Creates a cheat engine style hook, replacing instruction(s) with a JMP to a user provided set of ASM instructions (and optionally the original ones).
/// </summary>
/// <param name="asmCode">
/// The assembly code to execute, in FASM syntax.
/// (Should start with use32/use64)
/// </param>
/// <param name="functionAddress">The address of the function or mid-function to hook.</param>
/// <param name="behaviour">Defines what should be done with the original code that was replaced with the JMP instruction.</param>
/// <param name="hookLength">Optional explicit length of hook. Use only in rare cases where auto-length check overflows a jmp/call opcode.</param>
public AsmHook(string[] asmCode, nuint functionAddress, AsmHookBehaviour behaviour = AsmHookBehaviour.ExecuteFirst, int hookLength = -1)
: this(Utilities.Assembler.Assemble(asmCode), functionAddress, new AsmHookOptions() { Behaviour = behaviour, hookLength = hookLength })
{
}
public IAsmHook CreateAsmHook(byte[] asmCode, long functionAddress, AsmHookBehaviour behaviour, int hookLength) => new AsmHook(asmCode, (nuint)functionAddress.ToUnsigned(), behaviour, hookLength);
