Global columns: Handling of this var is crash prone on reloads
Global dahdi_dnd (struct dahdi_pvt *dahdichan, int flag): the use of the word "channel" for those dahdichans is really confusing.
File dnsmgr.c: There is a minor race condition. In the event that an IP address of a dnsmgr managed host changes, there is the potential for the consumer of that address to access the in_addr data at the same time that the dnsmgr thread is in the middle of updating it to the new address.