Go to the download section of ddccontrol project's page and download the latest ddccontrol and ddccontrol-db source tarballs.
Then unpack these two archives with:
# tar xvfz ddccontrol-X.Y.tar.gz # tar xvfz ddccontrol-db-YYYYMMDD.tar.gz
You should now have two directories, ddccontrol and ddccontrol-db.