I agree with most of what EB360 said. Don't bother batting arrows because Link can and will charge them, waiting for you to release your f-smash and then hitting you. When Link uses his arrows, he's got a bit of ending lag behind it, so keep that in mind. Also keep in mind that when his boomerang has already been thrown, he's unable to use it until it returns, so take advantage of that. His bombs, I would say are the biggest threat out of his B specials. The reason I say this is because when you blow up, he has a few options to follow up afterwards. You can try to absorb his bombs, but if Link gets wise, he'll fire an arrow before throwing a bomb at you, and if you're already in your PSI Magnet, then you take more damage than you should have.
Link is strong close up, but his projectile keeps him safe and when you put him in a situation where he's forced to fight close and he's relying heavily on projectile, then you're going to make him uncomfortable. I'm not a fan of campy characters to be honest. I have an issue with them and the best way for you to figure them out is to soak in as much learning experience as you can possible. There are probably good players who can tell you how to deal with campers, but until then, you're better off learning. And it sucks, because when you go up against a camper, it makes you predictable. At least that's how I feel.