implement proper SAPI3 handling for SMS

SM's need to be transferred over their own RLL connection on SAPI3, rather than
the default SAPI0 connection that we're using for signalling like 04.08
RR/MM/CC.

This is not that much of a problem in the case of SMS SUBMIT from the MS to
the netwrok.  In that case, the MS will start its primary RLL connection
with SAPI3, and we can just respond with SAPI3.

However, in the case of SMS DELIVER to a MS, we first page the MS, it then
establishes SAPI0.  We then need to explicitly request the establishment of
a SAPI3 RLL connection, before we can send CP-DATA with our RP-DATA and DELIVER
RPDU

Now that we have the bsc_rll.c code, we can actually wait for a paging
response, and from the paging response request the establishment of the SAPI3
connection.  We will be called back once that connection is open and can
successively start transmission of the SM.
2 files changed
tree: e036c3c05e8bba8e854a6e8c58afc3d86c660c03
  1. linux-kernel/
  2. openbsc/
  3. wireshark/