1999 Silverado Vortec 5.3

Noticed good size oil leak this evening. After looking under the hood, I noticed that a hose was disconnected. I managed to push it back in, but its still pretty loose. Wondering what the hose is, and if it just pushes in or did it have a fitting that broke. Im basically a noob at this stuff so any help would be appreciated. Pics provided.

 

Thats your PCV valve. Pull the hose off and then pull the metal valve out that it connects to and make sure it isn't clogged.

 

Pulled out the valve, it was pretty clogged. Just going to put a new one on. Thanks!