ddddmmmmNNNNeeeettttCCCCoooonnnnnnnneeeecccctttt is the sender side routine which sets up a control
connection. It opens a socket descriptor and tries to connect to the
specified address. It calls _c_o_n_n_e_c_t and sets appropriate socket options.
It requires a port and a hostname, specified through the parameters
DMNET_PORT and DMNET_REMOTE_HOSTNAME.
ddddmmmmNNNNeeeettttLLLLiiiisssstttteeeennnn and ddddmmmmNNNNeeeettttAAAAcccccccceeeepppptttt are the receiver side calls that set up a
control connection. ddddmmmmNNNNeeeettttLLLLiiiisssstttteeeennnn opens a socket descriptor for control,
sets socket options as appropriate, calls _b_i_n_d to bind the control socket
to a specified port and calls _l_i_s_t_e_n for an incoming connect request.
ddddmmmmNNNNeeeettttAAAAcccccccceeeepppptttt blocks until a connection is made.
DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
ddddmmmmNNNNeeeettttLLLLiiiisssstttteeeennnn , ddddmmmmNNNNeeeettttAAAAcccccccceeeepppptttt and ddddmmmmNNNNeeeettttCCCCoooonnnnnnnneeeecccctttt return DDDDMMMM____SSSSUUUUCCCCCCCCEEEESSSSSSSS if a
connection to the remote socket is made and the apropriate socket options
were set successfully and DDDDMMMM____FFFFAAAAIIIILLLLUUUURRRREEEE otherwise.
ddddmmmmNNNNeeeettttLLLLiiiisssstttteeeennnn returns DM_FAILURE and sets errno to EADDRINUSE if it cannot
bind to the specified port. ddddmmmmNNNNeeeettttLLLLiiiisssstttteeeennnn is idempotent, and can be called
more than once, to bind to different ports, for instance. ddddmmmmNNNNeeeettttAAAAcccccccceeeepppptttt
must be called only after ddddmmmmNNNNeeeettttLLLLiiiisssstttteeeennnn returns DM_SUCCESS.