Every if statement that includes a check for
the NFAPI_MODE that did not check for the new
PNF_STANDALONE_MODE now has been updated. Also
changed the tx_req and dl_config_req logs
when they are received at the OAI UE to be
info logs instead of error logs.
This change allows us to disable the LOG_I messages to reduce
overhead.
Removed LOG_VAR macro because it was used in only one place, and
a better solution is to simply use `__attribute__((unused))`.
NAS triggered the Kenb Refresh Req always for (hardcoded) UE 0. This
fixes this by setting the correct UE ID.
An effect of this was that the Kenb would always be set for UE 0,
regardless for which UE it was actually intended. This led for integrity
check failures for every UE with ID > 0.
- print current working directory
- print git version (if available)
- print security keys
this last one is a security breach, but as of today
it's not a problem
see https://gitlab.eurecom.fr/oai/openairinterface5g/issues/227
When the UE connects to the eNodeB and receives its IP address from the
network, it calls system() to set it in the linux kernel world. This call
is not done in a realtime thread, but in the NAS, which uses its own thread,
independent of the realtime processing.
In some situations this totally disrupts realtime processing.
It is difficult to know precisely why that happens, but it seems that calling
fork(), as system() does, in a multi-threaded program is not a good idea. (So
say several people on the internet.) It is not clear why the softmodem is
impacted, but it seems that fork() is really what triggers the disruption.
Several tests lead to that conclusion.
To fix the problem, we create a child background process very early in main()
(before anything else basically). Then instead of calling system(), the main
process sends the string to the background process. The background process
gets the string, passes it to system() and reports the success/failure back
to the main process.
This solution involves a lot of system calls, but calling system() in the
first place is not cheap either. As long as no realtime thread uses this
mechanism, things should be fine. Time will tell.
The compilation line was:
./build_oai --eNB -w USRP
The file openairinterface5g/cmake_targets/log/lte-softmodem.Rel10.txt
has been checked and all LOG_X (and 'msg') warnings have been fixed.
Those functions modify a global char array (a string).
Let's pass a buffer to those functions, so that it's
thread safe. The caller has been modified, with hopefully
a buffer big enough (still bigger than what was there before,
so should not break more than it did).
Michael Cook