
I would put him in another room when visitors call put him on a lead and introduce him make him sit when he is good give him a treat as he improves make him sit before you open the door to visitors have some treats in a pot by the door and ask visitors to give him a treat when he sits and is well behaved. (easier said than done I know)!
All puppies go through this stage the jumping up at hands and holding onto clothes I always have a small toy on me to put in thier mouths so that they come to learn that it is ok to chew the toy and not me.
when he does hurt shout OW as his mother would yelp to let him know that is not acceptable.
He will soon learn
good luck
Roni