hankhank / overload

Overload

What is overload.

A library to create shared libraries that can be LD_PRELOAD'd to intercept hook function calls in other shared libraries

How it works

If the executable uses dlopen and dlsym to load the library it hooks dlopen and then rewrites the PLT table entries for the specified symbols.

If the executable was linked against the library it specifies an init function that rewrites the PLT table entries for the specified symbols.

Usages

If you have an executable that uses library libfoo.so.1 and want to intercept a function call recv() without modifying the library or the executable build a shared library that includes overload.c and defines the array ol_funcs_to_hook, and puts the number of hooked functions in ol_num_hooked_funcs.

ol_logger must also be defined to handle logging from the overload wrapper.

Then run the executable like env LD_PRELOAD=liboverload.so exe

License

MIT