to decrypt packets, start a tox client like this
TOX_LOG_KEYS=/tmp/keys LD_PRELOAD=./result/lib/liblogkeys.so qtox
followed by wireshark like this
TOX_LOG_KEYS=/tmp/keys wireshark
the wireshark plugin should be in a path like:
-r-xr-xr-x 1 root root 29K Dec 31 1969 /home/clever/.local/lib/wireshark/plugins/2.6/epan/libtoxcore.so
example output