Opens an existing DHCP network container or creates a new container specified by netp and maskp (both host order) in location and initializes handpp to point to the instance handle. Performs any initialization needed by the data store. When creating a new DHCP network container, the caller's identity is used for owner/permissions. Valid flags include DSVC_CREATE, DSVC_READ, DSVC_WRITE, DSVC_NONBLOCK. Note that the creation of a DHCP network container as read-only (DSVC_CREATE | DSVC_READ) is invalid.