toxygen_wrapper

ctypes wrapping of Tox libtoxcore into Python. Taken from the wrapper directory of the now abandoned https://github.com/toxygen-project/toxygen next_gen branch by Ingvar.

There is not complete coverage of the c-toxcore api - they're written to support the toxygeb client. The basics of NGC groups are supported, as well as AV and toxencryptsave. There is no coverage of conferences as they are not used in toxygen and the list of still unwrapped calls as of Feb. 2024 can be found in docs/tox.c-toxcore.missing. The code is typed so that every call in tox*.py should have the right signature, and it runs toxygen with no apparent issues.

It has been tested with UDP and TCP proxy (Tor). It has not been tested on Windows, and there may be some minor breakage, which should be easy to fix. There is a good coverage integration testsuite in toxygen_wrapper/tests. Change to that directory and run tests_wrapper.py --help; the test suite gives a good set of examples of usage.

Install

Edit the Makefile and run make install or cd src and run toxygen_wrapper/tests/tests_wrapper.py

Then you need a libs directory beside the toxygen_wrapper directory and you need to link your libtoxcore.so and libtoxav.so and libtoxencryptsave.so into it. Link all 3 filenames to libtoxcore.so if you have only libtoxcore.so (which is usually the case if you built c-toxcore with cmake rather than autogen/configure). If you want to be different, the environment variable TOXCORE_LIBS overrides the location of libs; look in the file toxygen_wrapper/libtox.py for the details.

Tests

To test, run python3 src/toxygen_wrapper/tests/tests_wrapper.py --help

As is, the code in tox.py is very verbose. Edit the file to change

def LOG_ERROR(a): print('EROR> '+a)
def LOG_WARN(a): print('WARN> '+a)
def LOG_INFO(a): print('INFO> '+a)
def LOG_DEBUG(a): print('DBUG> '+a)
def LOG_TRACE(a): pass # print('TRAC> '+a)

to all pass # or use logging.logger to suite your tastes. logging.logger can be dangerous in callbacks in Qt applications, so we use simple print statements as default. The same applies to toxygen_wrapper/tests/tests_wrapper.py.

Prerequisites

No prerequisites in Python3.

Because this is using Ctypes, you can run it under a python-enabled gdb, which if you compiled the c-toxcore library -DCMAKE_BUILD_TYPE="Debug" means that you can run both the Python and the C under gdb. This is HUGE! The incantation is something like this:

gdb -ex r --args /usr/bin/python3 src/toxygen_wrapper/tests/tests_wrapper.py

with some suitable settings of PYTHONPATH and maybe LD_LIBRARY_PATH.

Other wrappers

There are a number of other wrappings into Python of Tox core. This one uses ctypes which has its merits - there is no need to recompile anything as with Cython - change the Python file and it's done. And you can follow things in a Python debugger, or with the utterly stupendous Python feature of gdb (gdb -ex r --args /usr/bin/python3.9 <pyfile>).

CTYPES code can be brittle, segfaulting if you've got things wrong, but if your wrapping is right, it is very efficient and easy to work on. The faulthandler module can be helpful in debugging crashes (e.g. from segmentation faults produced by erroneous C library wrapping).

Others include:

• https://github.com/TokTok/py-toxcore-c Cython bindings. Incomplete and not really actively supported. Maybe it will get worked on in the future, but TokTok seems to be working on java, go, etc. bindings instead, based on a homebrew generator written in undocumented, uncommented code in a language almost nobody knows, that nobody has installed, written by anonymous coders that are not open to suggestions. There's no active support by gdb`` for debugging Cython and python together like there is for cmake and gdb```. These bindings have no support for NGC groups; and no significant tests.

• https://github.com/oxij/PyTox forked from https://github.com/aitjcize/PyTox by Wei-Ning Huang aitjcize@gmail.com. Hardcore C wrapping which is not easy to keep up to date. No support for NGC but good tests. Abandonned. This was the basis for the TokTok/py-toxcore-c code until recently, and a version is on the 0.2.0 branch of TokTok/py-toxcore-c

To our point of view, the ability of these ctypes to follow code python and C code in the debugger is a crucial advantage.

Updates

Although Tox works over Tor, we do not recommend its usage for anonymity as it leaks DNS requests due to a 6-year old known security issue: https://github.com/TokTok/c-toxcore/issues/469 unless your Tox client does hostname lookups before calling Tox (like toxygen does). Otherwise, do not use it for anonymous communication unless you have a firewall in place.

The Tox project does not follow semantic versioning of its main structures or setters so the project may break the underlying ctypes wrapper at any time; it's not possible to use Tox version numbers to tell what the API will be. In which case you may have to go into the tox.py file in https://git.plastiras.org/emdee/toxygen_wrapper to fix it yourself. The last tested git commit is 5dd9ee3f65423a4095cacb8396a5d406a27610c7 2024-02-10

Up-to-date code is on https://git.plastiras.org/emdee/toxygen_wrapper

Work on this project is suspended until the MultiDevice problem is solved. Fork me!