libmsc/gsm_04_11.c: refactor MT SMS message handling
According to GSM TS 04.11, the SMC (Short Message Control) state
machine is a part of CM-sublayer of L3, that is responsible for
connection management (establisment and releasing), and SM-RP
(Relay Protocol) message delivery.
For some reason, the connection establisment request from SMC
(GSM411_MMSMS_EST_REQ) was not handled properly - it was
always assumed that connection is already established.
This is why the code initiating a MT (Mobile Terminated) SMS
transfer had to establish a radio connection with subscriber
manually.
Let's benefit from having the SMC state machine, and offload
connection establishment to it. This change makes the local
implementation closer to GSM TS 04.11, and facilitates the
further integration of GSUP transport.
NOTE: the expected unit test output is changed, because now we
always allocate a transaction first, and then establish a
connection, not vice versa.
Change-Id: I4a07ece80d8dd40b23da6bb1ffc9d3d745b54092
12 files changed