This is a lightweight and efficient library for detour hooking for Linux. It allows you to redirect the execution flow to your function before or after the original function is called.
To hook a function, create a Hook object and pass the address of the original function, the address of your own function, and the size of the stolen bytes. The stolen bytes size is the number of bytes that will be overwritten with a jump to your own function. In case you want to dynamically find this at runtime I recommend a length disassembler.
Hook* hook = new Hook(OriginalFunction, MyFunction, StolenBytesSize);After creating the Hook object, enable it by calling the Enable() method.
hook->Enable();If the hook was successfully enabled, the error member of the Hook object will be set to DETOURHOOKING_SUCCESS. You can check this by using an assertion:
assert(hook->error == DETOURHOOKING_SUCCESS);In case you want to disable the Hook you can use the Disable() method
hook->Disable();To minimize memory usage, the library reuses memory pages whenever possible. When you create a new hook, it will try to find a suitable location in memory to store the stolen bytes and the jump instruction. If no suitable location is found, it will allocate a new memory page.
Here's a simple example that hooks the puts function and adds a prefix to the output:
#include "DetourHooking.hpp"
#include <cstdio>
#include <cstdarg>
#include <cassert>
int MyPuts(const char *__s)
{
return printf("I can confirm this: %s", __s);
}
int main()
{
Hook* hook = new Hook((void*)puts, (void*) MyPuts, /* The stolen bytes size will vary for each system */);
hook->Enable();
assert(hook->error == DETOURHOOKING_SUCCESS);
puts("Detour Hooking is awesome\n");
return 0;
}Another example can be found in the Example subdirectory
- ChatGPT for writing large parts of this readme ^^