In the existing legal system you can't. But we could write laws that allow this to be a thing (i.e. instead of the current situation of "you have full control o

In the existing legal system you can't. But we could write laws that allow this to be a thing (i.e. instead of the current situation of "you have full control over who can copy/redistribute your IP" it becomes "anyone can copy/redistribute your IP but you are allowed to specify X criteria including the requirement to redistribute source code").