Frida: How to read a struct or a struct pointer or a pointer of a struct pointer?

frida-struct-pointer-pointer.js

/*

  typedef struct {
  
    int size;
    char* data;
  
  } test_struct;
  
  void some_func(test_struct **s);

*/

const some_func_pointer = Module.getExportByName('libsrtp', 'some_func');
const some_func = new NativeFunction(some_func_pointer, "void", ["pointer"]);
Interceptor.replace(some_func_pointer, new NativeCallback(function (pointer) {
  console.log(pointer.readPointer().readInt()) // size
  console.log(pointer.readPointer().add(Process.pointerSize).readPointer().readUtf8String()); // data
  some_func(pointer);
}, "void", ["pointer"]));

frida-struct-pointer.js

/*

  typedef struct {
  
    int size;
    char* data;
  
  } test_struct;
  
  void some_func(test_struct *s);

*/

const some_func_pointer = Module.getExportByName('libsrtp', 'some_func');
const some_func = new NativeFunction(some_func_pointer, "void", ["pointer"]);
Interceptor.replace(some_func_pointer, new NativeCallback(function (pointer) {
  console.log(pointer.readInt()) // size
  console.log(pointer.add(Process.pointerSize).readPointer().readUtf8String()); // data
  some_func(pointer);
}, "void", ["pointer"]));

frida-struct.js

/*

  typedef struct {
  
    int size;
    char* data;
  
  } test_struct;
  
  void some_func(test_struct s);

*/

const some_func_pointer = Module.getExportByName('libsrtp', 'some_func');
const some_func = new NativeFunction(some_func_pointer, "void", ["int", "pointer"]);
Interceptor.replace(some_func_pointer, new NativeCallback(function (size, data) {
  console.log(size)
  console.log(data.readUtf8String())
  some_func(size, data);
}, "void", ["int", "pointer"]));