How to let user submit url on post?

Hi.

I want something like link library, but to put button on every post.
When user clicks button, he will get simple form to add link.
And in admin panel I will see on which post user submited that link and that link of course.

Is there way of adding this with code or plugin.
I can’t find solution, all plugins are to add posts, but what about this, “Add link to existing post”.