hook_msgboxa/
hook_msgboxa.rs

1use hooking::Hook;
2use std::ffi::CStr;
3
4#[link(name = "user32")]
5unsafe extern "system" {
6    unsafe fn MessageBoxA(
7        hWnd: *mut std::ffi::c_void,
8        lpText: *const i8,
9        lpCaption: *const i8,
10        uType: u32,
11    ) -> i32;
12}
13
14unsafe extern "C" fn hook_destination(
15    _: *mut std::ffi::c_void,
16    lp_text: *const i8,
17    lp_caption: *const i8,
18    _: u32,
19) -> i32 {
20    let original_msgbox: extern "C" fn(*mut std::ffi::c_void, *const i8, *const i8, u32) -> i32 = unsafe {
21        std::mem::transmute(
22            hooking::original_function_ptr()
23                .expect("invoked from hook")
24                .as_ptr(),
25        )
26    };
27
28    println!(
29        "Called with title: {:?} | Body: {:?}",
30        unsafe { CStr::from_ptr(lp_text) },
31        unsafe { CStr::from_ptr(lp_caption) }
32    );
33
34    original_msgbox(
35        std::ptr::null_mut(),
36        c"msgbox was hooked!".as_ptr(),
37        c"Intercepted hook".as_ptr(),
38        0,
39    )
40}
41
42fn main() {
43    let mut hook = unsafe {
44        Hook::by_name(
45            Some(c"user32.dll"),
46            c"MessageBoxA",
47            hook_destination as *mut _,
48        )
49        .unwrap()
50    };
51
52    println!("Applying hook");
53
54    unsafe {
55        hook.apply_hook().unwrap();
56        MessageBoxA(
57            std::ptr::null_mut(),
58            c"Am i hooked?".as_ptr(),
59            c"hooked-rs".as_ptr(),
60            0,
61        );
62    }
63
64    unsafe {
65        hook.remove_hook().unwrap();
66        MessageBoxA(
67            std::ptr::null_mut(),
68            c"Not hooked anymore".as_ptr(),
69            c"hooked-rs".as_ptr(),
70            0,
71        );
72    }
73}
hook_msgboxa/hook_msgboxa.rs

hook_msgboxa/
hook_msgboxa.rs
