Commit Graph

211 Commits

Author SHA1 Message Date
Pau Espin d06ec27856 fix typo 's/dowlink/downlink/g'
Change-Id: Iae66aff9eed3856f09e58116ee26ec061733b076
2021-08-23 17:14:23 +02:00
Pau Espin f48de627f4 tbf: Move T3193 to tbf_state FSM
Related: OS#2709
Change-Id: Icf8249651e34132eb7ba99188a23662dec6f8653
2021-08-23 17:14:23 +02:00
Pau Espin a161bf48bd Simplify tbf::set_polling()
When setting a POLL, it will always happen on PACCH, so all the CCCH
part makes no sense there. Let's drop it and move the logging of each
case to the caller, where logging file+line is more useful.

Change-Id: I242f97fd6f927131ac64c1a7c9c3812b6389de04
2021-08-23 17:14:23 +02:00
Pau Espin ea8dbddab1 Move tbf ul_ack_state to osmocom FSM
Related: OS#2709
Change-Id: Icf23bf5a4b85fbcbf1542cebceb76b9ba7185d30
2021-08-23 17:14:23 +02:00
Pau Espin 405d2d10ec tbf_dl: Clarify requirements for DL ACK/NACK
Method is renamed since it clearly relates to getting DL ACK/NACK, no
CTRL ACK.

use same methods in both scheduler and internal use since they are
expectd to be run in the same code path by the scheduler. This way we
make sure the same conditions apply and it's clearer when looking at
the code.

Change-Id: Ib0e9b9547f5292b95064bab2dc182fdf659f0518
2021-08-23 17:14:23 +02:00
Pau Espin 3225290d77 Move timer X2002 to tbf_fsm
Related: OS#2709
Change-Id: I94b71c60ed49d51ebdf6d6b428056b4b94354676
2021-08-23 17:14:23 +02:00
Pau Espin fbc1baa139 tbf: Merge handle_ack_nack() into rcvd_dl_ack()
There's no real use in having those 2 methods separately, and only adds
complexity. Let's merge it to have 1 TBF code path handling DL ACK/NACK.

Change-Id: I546d2e46bda96a2f551b28673464e57831c71828
2021-08-23 17:14:23 +02:00
Pau Espin afe189e802 Get rid of lots of code only used by tests
There are 2 methods "rcvd_dl_ack()" in osmo-pcu code. One is used by
osmo-pcu itself, and the other is only used in tests.
Changing the tests to use the same method as osmo-pcu allows removing
the second one, and with it, a lot of code and complexity out of
osmo-pcu.

Change-Id: I14d9312cb61534dc97fca83141b9c0cd933c9206
2021-08-23 17:14:23 +02:00
Pau Espin 9d67e72e85 Move timer X2001 to tbf_fsm
The side effect is that the timer is enabled for other scenarios where a
PACCH assignment happens, like an Assignment Reject or Ul Assignment
(that's why there's more lines showing up now in TbfTest.err).

Change-Id: Ib8ab2f7397ad05c6fcd5dd74af55a1e2c56e1463
2021-08-23 17:14:22 +02:00
Pau Espin 49a2f404e8 replace dl_ass_state with osmocom FSM
Related: OS#2709
Change-Id: Ia33418478e17986a316ffda48b091030f53fa371
2021-08-23 17:14:22 +02:00
Pau Espin 284711d627 Get rid of tbf_dl:abort()
Having that code in a separate function is confusing and adds code
complexity since it looks like an entry point to start feeing a TBF, but
it simply some (not yet really useful) set of instructions to be called
one 1 code path in tbf_free.
Let's move it there, this way it becomes clear tbf_free() is THE place
to be (if you want to get rid of a TBF).

Change-Id: I30febf4d21a0bfab37524c07598bbb0dd32f7f65
2021-08-23 17:14:22 +02:00
Pau Espin 131deb059f Move rate_ctr free to tbf subclass destructor
This way we clean up tbf_free entry point, and leave memory freeing for
later on at the end when talloc_free is called.

Change-Id: I1c45e3296e565725bcbbca391d9518772fffa89d
2021-08-23 17:14:22 +02:00
Pau Espin 9dacf0b35b Remove duplicate call to gprs_rlcmac_lost_rep
Function is already called by gprs_rlcmac_received_lost(), so next call
following it will be sum=0 and return EINVAL.

Change-Id: I015ba16d18fdd6e2441ec3c256b5ac88771d7a8b
2021-08-23 17:14:22 +02:00
Pau Espin 62e06f92e9 Put dl_tbf::cleanup into destructor
It's fine to always attemt dropping the timer since it's set up in the
constructor.
This also drps the double function call abort()+cleanup() which is
confusing.

Change-Id: Ia2aaa43bd8faacf09fe4b36b11b38022bea7a59c
2021-08-23 17:14:21 +02:00
Pau Espin 55f600b702 Move RELEASING tbf_state transition to tbf_fsm
PdchUlcTest output changes because the original state NULL is not
expected when transactioning to RELEASING upon MAX N310* being hit. In
any case, none of those events should happen in NULL state, but we
don't really care about TBF states there so we are fine with whatever
the state is.

Related: OS#2709
Change-Id: I516b8d989a0d705e5664f8aeaf7d108e0105aa16
2021-08-23 17:14:21 +02:00
Pau Espin efcb046ce1 Move WAIT_RELEASE tbf_state transition to tbf_fsm
While at it, method maybe_start_new_window is renamed to
rcvd_dl_final_ack to make more sense out of the code.

Related: OS#2709
Change-Id: Iebd650c1036ef2d5132789778be7117ce3391c01
2021-08-23 17:14:21 +02:00
Pau Espin c32c4a3648 Move FINISHED tbf_state transition to tbf_fsm
Related: OS#2709
Change-Id: I81f507e3a2821254f03364a58ead02333e63099f
2021-08-23 17:14:21 +02:00
Pau Espin 33e8007100 Move NULL and ASSIGN tbf_state transition to tbf_fsm
At some point later in time the state_flags will most probably be split
into different variables, one ending up in a different FSM. It is moved
so far to the exsiting FSM from the C++ class since it's easier to
access it from C and C++ code, and anyway that kind of information
belongs to the FSM.

Related: OS#2709
Change-Id: I3c62e9e83965cb28065338733f182863e54d7474
2021-08-23 17:14:21 +02:00
Pau Espin 9c1db1738f Use new stat item/ctr getter APIs
Patch mostly done with the help of several small spatch snippets.

Change-Id: I600c7a8725f5b229b1a2feb879da7c3b2dce4505
2021-06-04 17:14:32 +02:00
Pau Espin dc2aaac29f tbf: Move existing tbf_state implementation to osmo_fsm
This is only an initial implementation, where all state changes are
still done outside the FSM itself.
The idea is to do the move in several commits so that they can be
digested better in logical steps and avoid major break up.

Related: OS#2709
Change-Id: I6bb4baea2dee191ba5bbcbec2ea9dcf681aa1237
2021-05-19 12:50:25 +02:00
Pau Espin 1a1557a60a Move TBF list from BTS to the TRX structure
The TBFs are managed per TRX. Move the global list from BTS to TRX.

Related: OS#1541
Change-Id: Id3c59c11d57d765fe68aaebaac94290c0d84feb2
2021-05-19 12:50:25 +02:00
Pau Espin 4b6f0bfe69 Implement T3141
Related: OS#1940
Change-Id: I154984b835b2b436b1ebe4631a8afcebb7338c65
2021-05-11 11:32:44 +02:00
Pau Espin 039ee8200a Clarify, document Assignment related timers
Related: OS#3928
Change-Id: Iad31a5c6f83cd78793adf05a6af782ceacae8b11
2021-04-26 18:49:58 +02:00
Pau Espin 16e1678bfc tbf: Get rid of attribute poll_ts
That field is not needed anymore, and it works only under the assumption
that only 1 poll request can be active at a time per TBF, which is not
true.

Change-Id: I9b8bed7741d385bab4cd8c64b841a78a02a05fe1
2021-03-31 17:39:50 +02:00
Pau Espin 58046e45d1 tbf: Get rid of attribute poll_fn
That field is not needed anymore, and it works only under the assumption
that only 1 poll request can be active at a time per TBF, which is not
true.

Change-Id: I63a34a702f028b871530fb7caeb13e8ea1cc78ac
2021-03-31 17:39:50 +02:00
Pau Espin 2c0931cedc Get rid of param 'poll' with constant value
Value 'false' is always passed by all callers of the function, so
there's no need to pass it. Furthermore, since it's false, there's no
need to access poll_fn since RRBP will always be invalid.

Change-Id: Ia48ce2a021865e76e813dedb22aca9c2522c5693
2021-03-31 17:39:50 +02:00
Pau Espin 127e7392f6 tbf: get rid of poll_state completely
The poll_state logic was part of previous implementation (prior to pdch
ul controller) where the ssumption was that TBF could only had 1 POLL
request in transit, which is really not true. With current
infrastructure we don't need this state tracking at all.

Change-Id: Ie5b807ccd38aa736ae11b3310ca61ad0156ca4d4
2021-03-31 17:39:50 +02:00
Pau Espin ed066b5328 tbf: Get rid of unneeded poll_scheduled()
This API is not really needed anymore, since anyway it works under the
assumption there can only be 1 POLL in transit per TBF, which isn't
necessarily true.

Change-Id: I875f51cade95faeb2d79dcebfead4c83e23a731b
2021-03-31 17:39:50 +02:00
Pau Espin 86580e1966 pdch_ulc: Store TBF poll reason
This allows easily checking the initial reason to trigger the poll when
either it is received or times out.

Later on this reason can be transformed into an FSM event and sent to
the related FSM.

Related: OS#5020
Change-Id: Ie8fefd1f47ad674ce597a8065b15284088956bde
2021-03-31 17:39:50 +02:00
Pau Espin Pedrol cf6c71263f tbf_dl: fix FBI not set upon X2031 = 0
If Idle TBF timer (X2031) is set to 0, it means the TBF release is
immediately started once all queued data has been scheduled. In that
case, we must set FBI=1 (by setting cv=0) and move to FINISH state.

This used to work over the usual path where X2031 != 0, because release
start will alays happen at a later sched poll time where a dummy LLC
frame is sent and FBI set accordingly.

Change-Id: Ib20602936ae084c413f6bfe14eea33b602020be0
2021-03-02 18:25:33 +01:00
Pau Espin Pedrol 8afc6bad80 tbf_dl: Fix m_last_dl_drained_fn not set under some conditions
Old commit getting rid of LLC UI dummy and updating create_new_bsn()
function introduced a bug by not moving update of value m_last_dl_drained_fn
prior to a new break introduced.
As a result, the value is not updated in the case LLC queue becomes
drained but last few bytes are drained at exactly that moment.
Furthermore, then the IDLE tbf timer (X2031, keep_open())) returns always
true since according to it the drain never happened.

The impact of the bug is basically delaying a bit more than expected the
time the TBF stays in IDLE state with the TBF release process yet
to be started.

Related: OS#4849
Fixes: 7d0f9a0ec3
Change-Id: I7420aeffda3500bcdc990291e4a56511af433ff9
2021-03-02 18:24:46 +01:00
Pau Espin Pedrol 5b9d0bb8e5 tbf: log keep_open condition status
Change-Id: I069e84926aaa8f13b23c3ea4083b4c68dbc6cff2
2021-03-02 13:13:52 +01:00
Pau Espin Pedrol a89008b724 tbd_dl: Don't re-initialize class field twice
Change-Id: Ia92c24032dc1f8965008ff03a3a0a94bbb93893a
2021-03-02 13:09:32 +01:00
Pau Espin 36177c6b58 tbf: Improve logging when TBF being allocated or no TBF avail
Change-Id: I68491fe2c643262e35b4d4f1ecac34afcf61848f
2021-02-26 11:50:15 +01:00
Pau Espin fc464935a4 Fix Dl EGPRS data blocks being generated occasionally on GPRS TBFs
Under some circumstances, it could happen that a DL TBF is created as a
GPRS TBF due to not yet having enough information of the MS, and only
after the TBF is created the PCU gains that information and upgrades the
MS mode to "EGPRS". Hence, there's the possibility to run into a
situation where a GPRS TBF is attached to a EGPRS MS.

It may also happen sometimes that despite the TBF and the MS be EGPRS,
there's need to further limit the DL MCS to use, eg. MCS1-4 (GMSK).

As a result, when asking for the current DL (M)CS to use, we must tell
the MS which kind of limitations we want to apply. The later reasoning
was already implemented when GPRS+EGPRS multiplexing was added, but the
former was not being checked. Hence, by further spreading through the
call stack the "req_kind_mode" we match both cases.

Related: OS#4973
Change-Id: Ic0276ce045660713129f0c72f1158a3321c5977f
2021-01-25 16:56:59 +01:00
Pau Espin db5e339da4 Get rid of singleton gprs_bssgp_pcu_current_bctx()
Access it from existing pointers instead.

Change-Id: I77455da5221090ebea142ecd49d5dba0065bfc5c
2021-01-21 18:02:57 +01:00
Pau Espin 8a35e640a3 Convert gprs_bssgp_pcu.cpp to C
There's no real use of C++ in that file, and it causes problems when
using llist_head entry macros in future patches adding initial support
for multiple BTS in PCU object, so let's move it to plain C.

Change-Id: Ic771a89fd78b5e66151a5384f0ff6a8895589466
2021-01-19 16:28:13 +01:00
Pau Espin 2182e627cd Unify BTS into a C usable structure
Previous work on BTS class started to get stuff out of the C++ struct
 into a C struct (BTS -> struct gprs_glcmac_bts) so that some parts of
it were accessible from C code. Doing so, however, ended up being messy
too, since all code needs to be switching from one object to another,
which actually refer to the same logical component.

Let's instead rejoin the structures and make sure the struct is
accessible and usable from both C and C++ code by rewriting all methods
to be C compatible and converting 3 allocated suboject as pointers.
This way BTS can internally still use those C++ objects while providing
a clean APi to both C and C++ code.

Change-Id: I7d12c896c5ded659ca9d3bff4cf3a3fc857db9dd
2021-01-19 16:28:10 +01:00
Pau Espin f473ec9d7a Move llc_* fields from BTS to PCU
Change-Id: Iffb916e53fdf99164ad07cd19e4b35a64136307e
2021-01-18 11:54:57 +01:00
Pau Espin 519d071131 Move ws_* fields from BTS to PCU
Change-Id: I997bc52f0d924c8f2a0b1d6cf23af98828ad4258
2021-01-18 11:54:57 +01:00
Pau Espin e8dcf64881 Move cs_adj* fields from BTS to PCU
Change-Id: I2b00a83279dccd4feeeeb95e34878c4405e7972c
2021-01-18 11:54:57 +01:00
Pau Espin 97296b299c Move dl_arq_type field from BTS to PCU
Change-Id: I0b82ab59edd58d60e5581c707dc49f58de0ba203
2021-01-18 11:54:53 +01:00
Pau Espin 05f9f59a67 Move dl_tbf_preemptive_retransmission field from BTS to PCU
Change-Id: I3ab32fcafe83f3ecb116a5b8a05f58f3fddc5451
2021-01-18 11:38:38 +01:00
Pau Espin 924aaad4bc Move T_defs_pcu from BTS to PCU object
Change-Id: I0cac5c12dff2e90b52d00383a00b4b94a9603a0a
2021-01-18 10:37:05 +00:00
Pau Espin Pedrol da971ee502 Convert GprsMS and helpers classes to C
As we integrate osmo-pcu more and more with libosmocore features, it
becomes really hard to use them since libosmocore relies heavily on C
specific compilation features, which are not available in old C++
compilers (such as designated initializers for complex types in FSMs).

GprsMs is right now a quite simple object since initial design of
osmo-pcu made it optional and most of the logic was placed and stored
duplicated in TBF objects. However, that's changing as we introduce more
features, with the GprsMS class getting more weight. Hence, let's move
it now to be a C struct in order to be able to easily use libosmocore
features there, such as FSMs.

Some helper classes which GprsMs uses are also mostly move to C since
they are mostly structs with methods, so there's no point in having
duplicated APIs for C++ and C for such simple cases.

For some more complex classes, like (ul_,dl_)tbf, C API bindings are
added where needed so that GprsMs can use functionalitites from that
class. Most of those APIs can be kept afterwards and drop the C++ ones
since they provide no benefit in general.

Change-Id: I0b50e3367aaad9dcada76da97b438e452c8b230c
2021-01-05 10:34:25 +00:00
Pau Espin 7d0f9a0ec3 Dl TBF: Get rid of LLC UI dummy blocks following other data
According to:
* 3GPP TS 44.060 version 16.0.0 "9.3.1a Delayed release of downlink Temporary Block Flow"
* 3GPP TS 44.064 version 16.0.0 "6.4.2.2 Unconfirmed Information (UI) Dummy command"

LLC UI Dummy frames are to be used when there no more data to send, only
in order to delay the release of a TBF. Hence, while not incorrect per
se, makes no sense to send those LLC UI Dummy frames inserted into
rlcmac blocks which already contain other LLC frames, since the MS in
that case is already being kept active.
It only makes sense to send those LLC UI Dummy frames when we have
nothing else to send, that is, alone inside a RLCMAC block without other
LLC frames.

Related: OS#4849
Change-Id: Ifae1a7b2b3dfad8df19585063088ba0df2749c8f
2020-12-01 15:57:37 +01:00
Pau Espin 022f9e56e5 Implement downgrade to DL MCS1-4 when USF for GPRS_only MS
In previous status, if USF for GPRS-only MS was selected, then EGPRS
TBFs were skipped and either a GPRS TBF was selected or a Dummy Block
was sent. That means the behavior was unfair towards EGPRS TBFs, because
sometimes they were skipped in favor of GPRS ones.
This patch imporves the situation in the above mentioned USF scenario, by
first, under specific conditions, allowing selection of an EGPRS TBF and
then forcing it to transmit in EGPRS-GMSK (MCS1-4) so that the
USF-targeted MS can still decode the USF, while at the same time
providing more fairness by allowing the EGPRS TBF to transmit data.

The specific conditions mentioned above are, mainly, related to the fact
that once a DL data block has been sent, and hence a BSN was assigned to
it, it cannot be retransmitted later using another MCS, since lower
MCS1-4 wouldn't be able to contain higher MCS RLC payload.

The set of conditions could be expanded in the future by also selecting
the EGPRS TBF if retransmition is required and the block to be
retransmitted was originally transmitted as MCS1-4.

Related: OS#4544
Change-Id: I9af23e175435fe9ae7b0e4119ad52fcd4707b9ca
2020-12-01 11:56:01 +00:00
Pau Espin 569f0d27c7 tbf_dl: Don't fake EGPRS MS class when no related info is available
For instance if PCU received DL data to be sent to an MS from an SGSN,
and the MS is not currently cached in the PCU (because there's no TBF
active for it), it will page it and transmit the DL data to it.
The SGSN is capable of sending (EGPRS) MS Class information in that same
DL data message, so it's the one responsible for providing that
information if not available at the PCU.
In the PCU if we don't have information about that MS and SGSN didn't
provide us information about it, we cannot assume the MS is going to be
EGPRS capable and even less expecting a specific EGPRS MS class.
So let's drop this code.

Related: OS#4544
Change-Id: Icce66cadb51af25ae0c3b3719940eccb548fe33b
2020-11-04 21:39:42 +01:00
Pau Espin 758ace867b tbf_dl: Update (egprs_)ms_class for already known MS
If SGSN provides us with MS class information upon DL data, let's use it
and set it in an already existing MS object if not yet known.

Also remove all unneeded code passing ms_class to append_data() which
would simply try to (again) set the ms_class.

Change-Id: I4979c9344bffd3ba7657bbab94981d233eab801f
2020-10-29 12:38:17 +01:00
Pau Espin 528820dbe1 tbf: Clean up gprs_rlcmac_dl_tbf::handle()
Avoid passing tons of params to internal helper function
tbf_nel_dl_assignment() in order to either fetch again the ms object or
create a new one. Let's instead create the ms function earlier if needed
and fill it with all the discovered information prior to calling the
helper function. This provides cleaner code and also better log output.

This way we also avoid trying to fill the MS twice and unneeded
getter+setter for TA.

tbf::imsi(): There' always an ms, so simply forward call to
ms()->imsi().

We can also get rid of assign_imsi, since the modified code is the only
place where it's used and there's already some code in place there to
update the MS. We instead merge it with set_imsi and keep the
duplication code to catch possible bugs from callers.

Move merge_and_clear_ms from tbf class to GprsMS, where it really
belongs.

Change-Id: Id18098bac3cff26fc4a8d2f419e21641a1f4c83b
2020-10-29 11:34:17 +00:00