| //! Vtable patching utilities for WA.exe's .rdata vtables. | |
| use core::mem::size_of; | |
| /// Temporarily make a vtable region writable, run a patcher closure, then | |
| /// restore the original memory protection. | |
| /// | |
| /// # Safety | |
| /// `vtable_addr` must point to a valid vtable with at least `slots` entries. | |
| pub unsafe fn patch_vtable( | |
| vtable_addr: *mut u32, | |
| slots: usize, | |
| patcher: impl FnOnce(*mut u32), | |
| ) -> Result<(), &'static str> { | |
| let mut old_protect: u32 = 0; | |
| let ok = windows_sys::Win32::System::Memory::VirtualProtect( | |
| vtable_addr as *mut core::ffi::c_void, | |
| slots * size_of::<u32>(), | |
| 0x04, // PAGE_READWRITE | |
| &mut old_protect, | |
| ); | |
| if ok == 0 { | |
| return Err("VirtualProtect failed on vtable"); | |
| } | |
| patcher(vtable_addr); | |
| windows_sys::Win32::System::Memory::VirtualProtect( | |
| vtable_addr as *mut core::ffi::c_void, | |
| slots * size_of::<u32>(), | |
| old_protect, | |
| &mut old_protect, | |
| ); | |
| Ok(()) | |
| } | |