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feat: AsmHook

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This commit is contained in:
Raymond 2021-08-30 16:33:57 -04:00
parent 3fd1637cf0
commit 369d7af8a0
4 changed files with 278 additions and 75 deletions
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73
Dalamud/Hooking/Internal/HookManager.cs
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@ -1,8 +1,11 @@
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using Dalamud.Logging.Internal;
using Dalamud.Memory;
using Iced.Intel;
using Microsoft.Win32;
namespace Dalamud.Hooking.Internal
@ -83,6 +86,76 @@ namespace Dalamud.Hooking.Internal
Originals.Clear();
}
/// <summary>
/// Follow a JMP or Jcc instruction to the next logical location.
/// </summary>
/// <param name="address">Address of the instruction.</param>
/// <returns>The address referenced by the jmp.</returns>
internal static IntPtr FollowJmp(IntPtr address)
{
while (true)
{
var hasOtherHooks = HookManager.Originals.ContainsKey(address);
if (hasOtherHooks)
{
// This address has been hooked already. Do not follow a jmp into a trampoline of our own making.
Log.Verbose($"Detected hook trampoline at {address.ToInt64():X}, stopping jump resolution.");
return address;
}
var bytes = MemoryHelper.ReadRaw(address, 8);
var codeReader = new ByteArrayCodeReader(bytes);
var decoder = Decoder.Create(64, codeReader);
decoder.IP = (ulong)address.ToInt64();
decoder.Decode(out var inst);
if (inst.Mnemonic == Mnemonic.Jmp)
{
var kind = inst.Op0Kind;
IntPtr newAddress;
switch (inst.Op0Kind)
{
case OpKind.NearBranch64:
case OpKind.NearBranch32:
case OpKind.NearBranch16:
newAddress = (IntPtr)inst.NearBranchTarget;
break;
case OpKind.Immediate16:
case OpKind.Immediate8to16:
case OpKind.Immediate8to32:
case OpKind.Immediate8to64:
case OpKind.Immediate32to64:
case OpKind.Immediate32 when IntPtr.Size == 4:
case OpKind.Immediate64:
newAddress = (IntPtr)inst.GetImmediate(0);
break;
case OpKind.Memory when inst.IsIPRelativeMemoryOperand:
newAddress = (IntPtr)inst.IPRelativeMemoryAddress;
newAddress = Marshal.ReadIntPtr(newAddress);
break;
case OpKind.Memory:
newAddress = (IntPtr)inst.MemoryDisplacement64;
newAddress = Marshal.ReadIntPtr(newAddress);
break;
default:
var debugBytes = string.Join(" ", bytes.Take(inst.Length).Select(b => $"{b:X2}"));
throw new Exception($"Unknown OpKind {inst.Op0Kind} from {debugBytes}");
}
Log.Verbose($"Resolving assembly jump ({kind}) from {address.ToInt64():X} to {newAddress.ToInt64():X}");
address = newAddress;
}
else
{
break;
}
}
return address;
}
private static unsafe void RevertHooks()
{
foreach (var (address, originalBytes) in Originals)