/*
* Return a new Object[] array with the contents of "args". We determine
* the number and types of values in "args" based on the method signature.
* Primitive types are boxed.
*
* Returns NULL if the method takes no arguments.
*
* The caller must call dvmReleaseTrackedAlloc() on the return value.
*
* On failure, returns with an appropriate exception raised.
*/
static ArrayObject* boxMethodArgs(const Method* method, const u4* args) {
const char* desc = &method->shorty[1]; // [0] is the return type.
/* count args */
size_t argCount = dexProtoGetParameterCount_fnPtr(&method->prototype);
/* allocate storage */
ArrayObject* argArray = dvmAllocArrayByClass_fnPtr(classJavaLangObjectArray,
argCount, ALLOC_DEFAULT);
if (argArray == NULL)
return NULL;
Object** argObjects = (Object**) (void*) argArray->contents;
/*
* Fill in the array.
*/
size_t srcIndex = 0;
size_t dstIndex = 0;
while (*desc != '\0') {
char descChar = *(desc++);
jvalue value;
switch (descChar) {
case 'Z':
case 'C':
case 'F':
case 'B':
case 'S':
case 'I':
value.i = args[srcIndex++];
argObjects[dstIndex] = (Object*) dvmBoxPrimitive_fnPtr(value,
dvmFindPrimitiveClass_fnPtr(descChar));
/* argObjects is tracked, don't need to hold this too */
dvmReleaseTrackedAlloc_fnPtr(argObjects[dstIndex], NULL);
dstIndex++;
break;
case 'D':
case 'J':
value.j = dvmGetArgLong(args, srcIndex);
srcIndex += 2;
argObjects[dstIndex] = (Object*) dvmBoxPrimitive_fnPtr(value,
dvmFindPrimitiveClass_fnPtr(descChar));
dvmReleaseTrackedAlloc_fnPtr(argObjects[dstIndex], NULL);
dstIndex++;
break;
case '[':
case 'L':
argObjects[dstIndex++] = (Object*) args[srcIndex++];
LOGD("boxMethodArgs object: index = %d", dstIndex - 1);
break;
}
}
return argArray;
}
static void dexspyCallHandler(const u4* args, JValue* pResult, const Method* method, ::Thread* self) {
OriginalMethodsIt original = findOriginalMethod(method);
if (original == dexspyOriginalMethods.end()) {
dvmThrowNoSuchMethodError("could not find Dexspy original method - how did you even get here?");
return;
}
ThreadStatus oldThreadStatus = self->status;
JNIEnv* env = self->jniEnv;
// get java.lang.reflect.Method object for original method
jobject originalReflected = env->ToReflectedMethod(
(jclass)dexspyAddLocalReference(self, original->clazz),
(jmethodID)method,
true);
// convert/box arguments
const char* desc = &method->shorty[1]; // [0] is the return type.
Object* thisObject = NULL;
size_t srcIndex = 0;
size_t dstIndex = 0;
// for non-static methods determine the "this" pointer
if (!dvmIsStaticMethod(&(*original))) {
thisObject = (Object*) dexspyAddLocalReference(self, (Object*)args[0]);
srcIndex++;
}
jclass objectClass = env->FindClass("java/lang/Object");
jobjectArray argsArray = env->NewObjectArray(strlen(method->shorty) - 1, objectClass, NULL);
while (*desc != '\0') {
char descChar = *(desc++);
JValue value;
Object* obj;
switch (descChar) {
case 'Z':
case 'C':
case 'F':
case 'B':
case 'S':
case 'I':
value.i = args[srcIndex++];
obj = (Object*) dvmBoxPrimitive(value, dvmFindPrimitiveClass(descChar));
dvmReleaseTrackedAlloc(obj, NULL);
break;
case 'D':
case 'J':
value.j = dvmGetArgLong(args, srcIndex);
srcIndex += 2;
obj = (Object*) dvmBoxPrimitive(value, dvmFindPrimitiveClass(descChar));
dvmReleaseTrackedAlloc(obj, NULL);
break;
case '[':
case 'L':
obj = (Object*) args[srcIndex++];
break;
default:
ALOGE("Unknown method signature description character: %c\n", descChar);
obj = NULL;
srcIndex++;
}
env->SetObjectArrayElement(argsArray, dstIndex++, dexspyAddLocalReference(self, obj));
}
// call the Java handler function
jobject resultRef = env->CallStaticObjectMethod(
dexspyClass, dexspyHandleHookedMethod, originalReflected, thisObject, argsArray);
// exceptions are thrown to the caller
if (env->ExceptionCheck()) {
dvmChangeStatus(self, oldThreadStatus);
return;
}
// return result with proper type
Object* result = dvmDecodeIndirectRef(self, resultRef);
ClassObject* returnType = dvmGetBoxedReturnType(method);
if (returnType->primitiveType == PRIM_VOID) {
// ignored
} else if (result == NULL) {
if (dvmIsPrimitiveClass(returnType)) {
dvmThrowNullPointerException("null result when primitive expected");
}
pResult->l = NULL;
} else {
if (!dvmUnboxPrimitive(result, returnType, pResult)) {
dvmThrowClassCastException(result->clazz, returnType);
}
}
// set the thread status back to running. must be done after the last env->...()
dvmChangeStatus(self, oldThreadStatus);
}
/*
* Return a new Object[] array with the contents of "args". We determine
* the number and types of values in "args" based on the method signature.
* Primitive types are boxed.
*
* Returns NULL if the method takes no arguments.
*
* The caller must call dvmReleaseTrackedAlloc() on the return value.
*
* On failure, returns with an appropriate exception raised.
*/
static ArrayObject* boxMethodArgs(const Method* method, const u4* args)
{
const char* desc = &method->shorty[1]; // [0] is the return type.
ArrayObject* argArray = NULL;
int argCount;
Object** argObjects;
bool failed = true;
/* count args */
argCount = dexProtoGetParameterCount(&method->prototype);
/* allocate storage */
argArray = dvmAllocArray(gDvm.classJavaLangObjectArray, argCount,
kObjectArrayRefWidth, ALLOC_DEFAULT);
if (argArray == NULL)
goto bail;
argObjects = (Object**) argArray->contents;
/*
* Fill in the array.
*/
int srcIndex = 0;
argCount = 0;
while (*desc != '\0') {
char descChar = *(desc++);
JValue value;
switch (descChar) {
case 'Z':
case 'C':
case 'F':
case 'B':
case 'S':
case 'I':
value.i = args[srcIndex++];
argObjects[argCount] = (Object*) dvmWrapPrimitive(value,
dvmFindPrimitiveClass(descChar));
/* argObjects is tracked, don't need to hold this too */
dvmReleaseTrackedAlloc(argObjects[argCount], NULL);
argCount++;
break;
case 'D':
case 'J':
value.j = dvmGetArgLong(args, srcIndex);
srcIndex += 2;
argObjects[argCount] = (Object*) dvmWrapPrimitive(value,
dvmFindPrimitiveClass(descChar));
dvmReleaseTrackedAlloc(argObjects[argCount], NULL);
argCount++;
break;
case '[':
case 'L':
argObjects[argCount++] = (Object*) args[srcIndex++];
break;
}
}
failed = false;
bail:
if (failed) {
dvmReleaseTrackedAlloc((Object*)argArray, NULL);
argArray = NULL;
}
return argArray;
}
static void xposedCallHandler(const u4* args, JValue* pResult,
const Method* method, ::Thread* self) {
if (!xposedIsHooked(method)) {
dvmThrowNoSuchMethodError(
"could not find Xposed original method - how did you even get here?");
return;
}
XposedHookInfo* hookInfo = (XposedHookInfo*) method->insns;
Method* original = (Method*) hookInfo;
Object* originalReflected = hookInfo->reflectedMethod;
Object* additionalInfo = hookInfo->additionalInfo;
// convert/box arguments
const char* desc = &method->shorty[1]; // [0] is the return type.
Object* thisObject = NULL;
size_t srcIndex = 0;
size_t dstIndex = 0;
// for non-static methods determine the "this" pointer
if (!dvmIsStaticMethod(original)) {
thisObject = (Object*) args[0];
srcIndex++;
}
ArrayObject* argsArray = dvmAllocArrayByClass(objectArrayClass,
strlen(method->shorty) - 1, ALLOC_DEFAULT);
if (argsArray == NULL) {
return;
}
while (*desc != '\0') {
char descChar = *(desc++);
JValue value;
Object* obj;
switch (descChar) {
case 'Z':
case 'C':
case 'F':
case 'B':
case 'S':
case 'I':
value.i = args[srcIndex++];
obj = (Object*) dvmBoxPrimitive(value,
dvmFindPrimitiveClass(descChar));
dvmReleaseTrackedAlloc(obj, self);
break;
case 'D':
case 'J':
value.j = dvmGetArgLong(args, srcIndex);
srcIndex += 2;
obj = (Object*) dvmBoxPrimitive(value,
dvmFindPrimitiveClass(descChar));
dvmReleaseTrackedAlloc(obj, self);
break;
case '[':
case 'L':
obj = (Object*) args[srcIndex++];
break;
default:
ALOGE("Unknown method signature description character: %c\n",
descChar);
obj = NULL;
srcIndex++;
}
xposedSetObjectArrayElement(argsArray, dstIndex++, obj);
}
// call the Java handler function
JValue result;
dvmCallMethod(self, xposedHandleHookedMethod, NULL, &result,
originalReflected, (int) original, additionalInfo, thisObject,
argsArray);
dvmReleaseTrackedAlloc(argsArray, self);
// exceptions are thrown to the caller
if (dvmCheckException(self)) {
return;
}
// return result with proper type
ClassObject* returnType = dvmGetBoxedReturnType(method);
if (returnType->primitiveType == PRIM_VOID) {
// ignored
} else if (result.l == NULL) {
if (dvmIsPrimitiveClass(returnType)) {
dvmThrowNullPointerException("null result when primitive expected");
}
pResult->l = NULL;
} else {
if (!dvmUnboxPrimitive(result.l, returnType, pResult)) {
dvmThrowClassCastException(result.l->clazz, returnType);
}
}
}
