/usr/lib/x86_64-linux-gnu/libsocketcan.so is in libsocketcan-dev 0.0.10+git20140721-6.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libsocketcan.so.2.2.1
/usr/lib/x86_64-linux-gnu/libsocketcan.so.2.2.1