static void InstallHook(HookData hook)
{
Console.WriteLine(hook.Host.FullName + " => " + hook.Virus.FullName);
switch (hook.Type)
{
case "Before":
{
InstallHookBefore(hook);
break;
}
case "After":
{
InstallHookAfter(hook);
break;
}
default:
{
Console.WriteLine("Unknow hook type : " + hook.Type);
break;
}
}
}
static void InstallHookAfter(HookData hook)
{
if (!CheckSignatureCompatibility(hook.Host, hook.Virus, true))
{
Console.WriteLine("Error : Method signature difference between Hook and Target");
return;
}
foreach (var arg in hook.Host.Parameters)
{
Console.WriteLine(arg.Name + " : " + arg.ParameterType);
}
foreach (var arg in hook.Virus.Parameters)
{
Console.WriteLine(arg.Name + " : " + arg.ParameterType);
}
bool hasReturnType = hook.Host.ReturnType.FullName != "System.Void";
VariableDefinition returnVar = null;
if (hasReturnType)
{
returnVar = new VariableDefinition("returnVar", hook.Host.ReturnType);
hook.Host.Body.Variables.Add(returnVar);
}
var ilp = hook.Host.Body.GetILProcessor();
var last = hook.Host.Body.Instructions[hook.Host.Body.Instructions.Count - 1]; // Ret
// Store original return value
if (hasReturnType)
{
ilp.InsertBefore(last, ilp.Create(OpCodes.Stloc, returnVar));
}
// Add this parameter
if (hook.Host.HasThis && !hook.Host.ExplicitThis)
{
ilp.InsertBefore(last, ilp.Create(OpCodes.Ldarg_0));
}
// Add parameters
foreach (var param in hook.Host.Parameters)
{
ilp.InsertBefore(last, ilp.Create(OpCodes.Ldarg, param));
}
// Load original return value
if (hasReturnType)
{
ilp.InsertBefore(last, ilp.Create(OpCodes.Ldloc, returnVar));
}
ilp.InsertBefore(last, ilp.Create(OpCodes.Call, hook.Host.Module.Import(hook.Virus)));
}
static List <HookData> GetHookList(AssemblyDefinition hookAssembly)
{
List <HookData> hooks = new List <HookData>();
foreach (var module in hookAssembly.Modules)
{
foreach (var type in module.Types)
{
foreach (var method in type.Methods)
{
HookData hook = GetHookAttribute(method);
if (hook != null)
{
hooks.Add(hook);
}
}
}
}
return(hooks);
}
static void InstallHookBefore(HookData hook)
{
if (!CheckSignatureCompatibility(hook.Host, hook.Virus, false))
{
Console.WriteLine("Error : Method signature difference between Hook and Target");
return;
}
if (hook.Virus.ReturnType.FullName != "System.Void")
{
Console.WriteLine("Error : Hook must return void");
return;
}
foreach (var arg in hook.Host.Parameters)
{
Console.WriteLine(arg.Name + " : " + arg.ParameterType);
}
foreach (var arg in hook.Virus.Parameters)
{
Console.WriteLine(arg.Name + " : " + arg.ParameterType);
}
var ilp = hook.Host.Body.GetILProcessor();
var first = hook.Host.Body.Instructions[0];
if (hook.Host.HasThis && !hook.Host.ExplicitThis)
{
ilp.InsertBefore(first, ilp.Create(OpCodes.Ldarg_0));
}
foreach (var param in hook.Host.Parameters)
{
ilp.InsertBefore(first, ilp.Create(OpCodes.Ldarg, param));
}
ilp.InsertBefore(first, ilp.Create(OpCodes.Call, hook.Host.Module.Import(hook.Virus)));
}
static MethodDefinition FindTargetHook(AssemblyDefinition targetAssembly, HookData hook)
{
foreach (var module in targetAssembly.Modules)
{
foreach (var type in module.Types)
{
if (!(type.Namespace == hook.Namespace && type.Name == hook.Class))
{
continue;
}
foreach (var method in type.Methods)
{
if (method.Name == hook.Method)
{
return(method);
}
}
}
}
return(null);
}