Violent 17 month old

For some reason since my son turned one he has become very violent. He has always been the sweetest and loving kid and now he has these violent streaks. He will go from hugging me to slapping and hitting me. He will throw his toys at me or hit me with things like fly swatters or remotes. I’ve tried hand smacking and it doesn’t seem to affect him at all. I am hesitant to spank him because I’ve read that it won’t be effective at his age but I’m at a total loss at what to do. I don’t know if this is just a phase but I don’t want this to be a permanent behavior. I have tried redirecting and time out and nothing seems to get him to understand that he is hurting me.