Introduce the structure nr_pdcp_integrity_data_t and adapt code to use it.
Note: in nr_pdcp_sdu_t we keep the 'count' variable (which is also present
in nr_pdcp_integrity_data_t). They represent the same value, but 'count'
in nr_pdcp_integrity_data_t is to be specifically used for integrity while
the other one has other uses, so it's better to keep it.
The case securityModeFailure didn't seem to be implemented
properly, so I just removed it entirely.
The variable 'securityMode' did not make much sense, removed as well.
Plus for integrity, there was: securityMode |= 1 << 5 for nea1
and << 6 for nea2, which does not seem correct (I would expect << 4
and << 5 respectively), so it was properly incorrect.
'securityModeCommand->criticalExtensions.choice.securityModeCommand'
was accessed before checking that
'securityModeCommand->criticalExtensions.present'
is 'NR_SecurityModeCommand__criticalExtensions_PR_securityModeCommand',
which is wrong.
The tests 'securityMode >= NO_SECURITY_MODE' and 'securityMode != 0xff'
don't make sense/are unclear, so removed too.
So let's simplify this function, wrong in several places. And put
some AssertFatal() so that the code won't do weird things. The
AssertFatal() can be removed later and the function improved later
if needed. The case securityModeFailure can also be handled later,
but I think there is more work to do than just encoding the message
and send it to the gNB, so it's not bad to remove it for the moment.
The use of security_mode_completed in the PDCP entity was a hack.
Plus it was not working at all with the deregistration request
when nea2 is used, sent when doing ctrl+c in the nrUE.
So let's remove it.
And let's handle activation of integrity and ciphering more in
accordance with what 38.331 says. SecurityModeComplete has to
be sent integrity protected, but not ciphered. Only after should
the ciphering be activated. (See 38.331 5.3.4.3.)
38.473 section 8.2.3.1 says that upon F1 Setup Request, UE associated
signalling should be erased. In this commit, we trigger a release of all
UEs that were still connected to a DU when we received the SCTP
shutdown, i.e., when the DU disconnects.
From the spec, it does not seem to be mandated to check that the random
identity needs to be unique within a cell. Also, from experience we see
that this only happens when the same UE "comes back"; so since one UE
can only have one connection, the other RRC UE contexts (with the same
identity) should be removed at some point, anyway, leaving only one with
the same identity.
They use 4G NUMBER_OF_UE_MAX, which is not supposed to be present in 5G.
Further, the mutex and variable are global state; for Paging, we should
use F1.
We can only support up to 30 UEs for SRS. In this commit, we change:
- if the total number of UEs is > 32, throw error during compilation to
raise awareness (32 so that a multiple of two still works, everything
else is confusing, see also next point)
- during runtime, handle gracefully if UID is 30 or 31 to not abort (we
can simply not allocate SRS resources)
Also, refactor config_srs() to always give back new memory; the code is
shorter and clearer. Rename to get_contig_srs() to make it explicit.
Guido Casati