Struct Replacement 

pub struct Replacement { /* private fields */ }

A replacement of an entry in the PLT section.

The address in the PLT entry is restored when this value is dropped.

Implementations

impl Replacement

pub fn original_address(&self) -> *const c_void

Returns the original address of the PLT entry.

This address can be used to invoke the function replaced by ObjectFile::replace.

Example

use plthook::ObjectFile;
use std::mem;

extern "C" fn broken_getpid() -> libc::pid_t {
    -1
}

let program = ObjectFile::open_main_program().unwrap();

let pid = unsafe { libc::getpid() };
assert_ne!(pid, -1);

// Replace getpid with our broken function.

let replacement = unsafe {
    program.replace("getpid", broken_getpid as *const _).unwrap()
};

let libc_getpid: extern "C" fn() -> libc::pid_t = unsafe {
    mem::transmute(replacement.original_address())
};

assert_eq!(unsafe { libc::getpid() }, -1);
assert_eq!(unsafe { (libc_getpid)() }, pid);

drop(replacement);
assert_eq!(unsafe { libc::getpid() }, pid);

pub fn discard(&mut self)

Discard this replacement, so the original address will not be restored when this replacement is dropped.

Trait Implementations

impl Drop for Replacement

fn drop(&mut self)

Executes the destructor for this type.