sonals / softk

Dynamic library C API signature extraction for dynamic invocation

This library extracts function signatures of exported C functions in an ELF file and creates a table of function to an ffi_type array describing the function parameters. For signature extraction, this library requires the input ELF to be compiled with DWARF information generated with gcc -g switch. Note -g should be used even when the input ELF is compliled with optimization like -O2 or -O3.

Dependencies

1. libdw
2. libelf
3. libffi

Build

Release

mkdir -p build/Release
cd build/Release
cmake -DCMAKE_BUILD_TYPE=Release ../../src/
make
make test

Debug

mkdir -p build/Debug
cd build/Debug
cmake -DCMAKE_BUILD_TYPE=Debug ../../src/
make
make test

Usage

./sk <elf_file_with_debug_symbols>

Example Session

xsjsonalsmbp:~/<1>softk/build/Debug>./sk ./sk
Using shared object file: ./sk
----
main(int argc, * argv)
----
----
poo(?? tear, float fear)
----
----
doo(int ear, * var)
----
----
zoo(int8_t zar, int16_t dar)
----
----
foo(* bar, double baz)
----
xsjsonalsmbp:~/<1>softk/build/Debug>

TODO

Add infrastructure to the library to dlopen an input ELF, enumerate symbols using generated signal table, find a given function's entry point using dlsym and then invoke the function after dynamically assembling a call frame using user provided function args.