I have to do a weird thing - forking during initialization of static variables. I turns out main() is too late for that, because we bind sockets in static variables and when we run second instance, it fails in bind and not in our lockfile checking code. Some other ramifications come out because of our heavy use of global variables. Don't do that in your next project - use global variables only when strictly necessary.
This patch adds ability to connect to OpenBTS CLI with TCP socket and UNIX socket. This is configurable in the config file. To connect to the CLI use apps/OpenBTScli executable, which reads configuration from the same config file.
Idea is to make OpenBTS as dumb as possible. It should forward all received SMS messages' RPDU to SMSC (smqueue) and vice versa. All actual message decoding and processing is to be done in smqueue.
Alexander Chemeris