/// <summary>
/// 备份原始方法头
/// </summary>
protected virtual void BackupHeader()
{
byte *pTarget = (byte *)_targetPtr.ToPointer();
_backupArray = new byte[_headSize];
for (int i = 0; i < _headSize; i++)
{
if (_proxyPtr != null)
{
_proxyPtr[i] = pTarget[i];
}
_backupArray[i] = pTarget[i];
}
if (_proxyPtr != null)
{
int index = 0;
if (LDasm.CheckShortCall(_proxyPtr, s_jmpBuff.Length, out index))
{
if (!NativeAPI.IsAndroidARM())
{
// 目标地址 = 偏移 + 5 + 指令地址
int oldOffsetAddr = *((int *)(_proxyPtr + index + 1));
long targetAddr = oldOffsetAddr + 5 + (long)_targetPtr + index;
// 因为指令地址发生了改变，所以要重新计算偏移 公式: 偏移 = 目标地址 - 指令地址 - 5
int newOffsetAddr = (int)(targetAddr - ((long)_proxyPtr + index) - 5);
*((int *)(_proxyPtr + index + 1)) = newOffsetAddr;
}
}
}
}
/// <summary>
/// 备份原始方法头
/// </summary>
protected virtual void BackupHeader()
{
byte *pTarget = (byte *)_targetPtr.ToPointer();
_backupArray = new byte[_headSize];
for (int i = 0; i < _headSize; i++)
{
if (_proxyPtr != null)
{
_proxyPtr[i] = pTarget[i];
}
_backupArray[i] = pTarget[i];
}
if (_proxyPtr != null)
{
int index = 0;
if (LDasm.CheckShortCall(_proxyPtr, s_jmpBuff.Length, out index))
{
if (IntPtr.Size == 8)
{
// 目标地址 = 偏移 + 5 + 指令地址
int oldOffsetAddr = *((int *)(_proxyPtr + index + 1));
long targetAddr = oldOffsetAddr + 5 + (long)_targetPtr + index;
fixed(byte *p = &s_jmpBuff[s_addrOffset])
{
IntPtr *ptr = (IntPtr *)p;
*ptr = (IntPtr)targetAddr;
}
// 原来的跳转指令长度为5，现在为 14所以把_headsize 拓宽
_headSize = _headSize - 5 + 14;
for (int i = index; i < 14 + index; i++)
{
_proxyPtr[i] = s_jmpBuff[i - index];
}
}
else
{
// 目标地址 = 偏移 + 5 + 指令地址
int oldOffsetAddr = *((int *)(_proxyPtr + index + 1));
long targetAddr = oldOffsetAddr + 5 + (long)_targetPtr + index;
// 因为指令地址发生了改变，所以要重新计算偏移 公式: 偏移 = 目标地址 - 指令地址 - 5
int newOffsetAddr = (int)(targetAddr - ((long)_proxyPtr + index) - 5);
*((int *)(_proxyPtr + index + 1)) = newOffsetAddr;
}
}
}
}
/// <summary>
/// 创建一个 native Hooker
/// </summary>
/// <param name="libraryName">C/C++ 本地库名字</param>
/// <param name="symbol">方法符号</param>
/// <param name="replace">替换委托</param>
public NativeMethodHooker(string libraryName, string symbol, Delegate replace)
{
SetupJmpBuff();
IntPtr targetPtr = NativeAPI.miku_hooker_get_address(libraryName, symbol);
_headSize = (int)LDasm.SizeofMinNumByte(targetPtr.ToPointer(), s_jmpBuff.Length);
_proxyBuffSize = _headSize + s_jmpBuff.Length;
_targetPtr = targetPtr;
_replacPtr = Marshal.GetFunctionPointerForDelegate(replace);
_proxyPtr = (byte *)NativeAPI.miku_hooker_jit_alloc(IntPtr.Zero, _proxyBuffSize);
Install();
}
/// <summary>
/// 创建一个 Hooker
/// </summary>
/// <param name="target">需要替换的目标方法</param>
/// <param name="replace">准备好的替换方法</param>
private CSharpMethodHooker(MethodBase target, MethodBase replace, MethodBase proxy)
{
SetupJmpBuff();
IntPtr targetPtr = NativeAPI.GetFunctionAddr(target);
IntPtr replacePtr = NativeAPI.GetFunctionAddr(replace);
IntPtr proxyPtr = NativeAPI.GetFunctionAddr(proxy);
_headSize = (int)LDasm.SizeofMinNumByte(targetPtr.ToPointer(), s_jmpBuff.Length);
_proxyBuffSize = _headSize + s_jmpBuff.Length;
_proxyPtr = (byte *)proxyPtr.ToPointer();
_targetPtr = targetPtr;
_replacPtr = replacePtr;
Install();
}
