Hook libc functions with an easy API
https://docs.rs/rhook
1- Import the trait [RunHook]
2- Create an Command with Command::new and add hooks to it via addhook and addhooks methods
3- Confirm the hooks with set_hooks method this step is necessary
4- Now you can carry on with the usual Command methods (output, spawn,status,..)
Say you want to limit the bandwidth 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 is the function's input/output
2- use this crate ```rust use rhook::{RunHook, Hook};
std::process::Command::new("speedtest").addhook(Hook::Recv(stringify!(|sockfd, buf, len, flags|{ std::thread::sleepms(10); originalrecv(sockfd, buf, len, flags) }))).sethooks().unwrap().spawn(); ```
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
To check if a program dynamicly loads libc use ldd $path_to_program
To check what libc functions a program calls use nm -D $path_to_program
Check out the examples for more info
License: MIT