Crate rhook[−][src]

Rhook

Hooks libc functions with an easy API

Example

Say you want to limit the badnwhidth of a program

Usually downloading calls libc::recv function

So our goal is to throttle it with a simple sleep

To do that with this crate: (taking speedtest program as an example)

1- Check its manpage https://man7.org/linux/man-pages/man2/recv.2.html to see what the function’s input/output

2- use this crate

run_with(vec!("speedtest"), vec!(Hook::Recv(stringify!(|sockfd, buf, len, flags|{
  std::thread::sleep_ms(100);
  original_recv(sockfd, buf, len, flags)
}))))

Thats it! Note that you have acess inside the closure to the original function denoted by the prefix original_ + the function name

Couple of points:

If you take ownership of an input value inside of the closure, be sure to use ManuallyDrop so you don’t free it

Check out the tests for more examples

Enums

Hook

libc hook

Functions

run_with

run a program with the specified hooks