Commit Graph

87 Commits

Author SHA1 Message Date
Vadim Yanitskiy 6a97cd39b6 Move power control related definitions to power_control.h
Now that we have separate header/code files for the power control,
let's move the related definitions there.  This change makes the
code consistent with osmo-bts, where it's already done this way.

Change-Id: I1cb3f6bfba0306e8f371dcd5162d1813beb3a088
2022-04-08 01:23:04 +03:00
Vadim Yanitskiy 6c33014bb9 power_ctrl_params_def_reset(): set .ctrl_interval for both UL/DL
For the sake of consistency and code readability, initialize the
power loop control interval (P_Con_INTERVAL) for both Uplink and
Downlink directions in the same function.

Change-Id: Ie3d4b481cbfacf27004787616e22b6f8a863b47b
2022-04-08 01:12:17 +03:00
Pau Espin 90b689b577 Disable C/I based MS Power Control Loop by default
osmo-trx-uhd with a B200 has proven to provide bad (lower than usually
considered good) C/I values due to high noise (even with band filters in
place). Hence, default thresholds (gathered from literature on the topic)
are too high and end up in bad algorithm output decisions.
Furthermore, most users of Osmocom don't use it in densely populated
areas, hence RXLEV based algorithm used when C/I based one is disabled
is good enough.
Let's disable C/I based one by default, and let advanced users which
specific needs to enable and confiure thresholds specifically for their
needs (hardware, cell surrounding conditions, etc.).

Related: SYS#4917
Change-Id: If1a73c60695379bcfcd0f44c6ec6dd659563e279
2021-11-25 14:50:04 +01:00
Vadim Yanitskiy 5944ff07a8 gsm_data: use ascending order for interference boundaries
It's more logical to have the boundaries sorted in ascending order:

  * band 1 represents lowest interference levels,
  * band 5 represents highest interference levels.

Change-Id: Ie9bf4bf0c89418685b8ea5096332d22cfba7c521
Related: SYS#5313
2021-11-10 14:45:12 +03:00
Pau Espin 7be36cfde6 Set subslots_per_pchan_vamos[GSM_PCHAN_OSMO_DYN] = 0
VAMOS secondary lchans are to be used specifically when the osmocom dyn
TS is set to pchan_is=TCH_{F,H}. Setting secondary subslots for
OSMO_DYN TS is not needed since it's only used to initialize the TS, and
OSMO DYN already initializes 8 subslots
(subslots_per_pchan[GSM_PCHAN_OSMO_DYN]=8). Otherwise, ts_setup_lchans()
will try to initialize 8+2 lchans on the TS, which is more than needed
and will access out of bounds in the array.

Related: OS#5278
Change-Id: I8727d5b446179c0ebcd8738507efe5a50afaf1e2
2021-10-25 19:17:51 +02:00
Pau Espin 410a1be79e Set subslots_per_pchan[GSM_PCHAN_OSMO_DYN] = 8
Since a while ago, osmocom types dynamic TS supports being configured as
SDCCH8, hence the maximum subslots is 8. This fixes issue where only up
to 2 subslots where being used on those TS.

Related: OS#5278
Related: SYS#5309
Fixes: 52b9912ef9
Change-Id: I50e6530284ef49cfd77d1944d4a183c5df345820
2021-10-25 13:43:48 +02:00
Pau Espin d203d173f2 MS Power Control Loop: Use P_CON_INTERVAL=2 by default
Increase the reaction time at the expense of more stable loop with less
temporary oscillations.

See updated user manual documentation in this commit for a larger
description.

Related: SYS#5371
Change-Id: I46be244a5e01a74086e3a977ec3ea139742a0074
2021-10-07 10:44:44 +00:00
Pau Espin 464227d071 MS Power Control Loop: Allow Turn off/on C/I independent from value setting
Improve the current VTY support to allow enabling/disabling C/I logic
independent from value setting. This way C/I support can be quickly
disabled & enabled.

Reminder: changing power parameters still require VTY Command "bts NR
resend-power-control-defaults" to be excuted prior to new parameters
being applied on the BTS.

Related: SYS#4917
Change-Id: Id1224c2d9a52db2ed805c49e048d3086ed0167f5
2021-09-29 15:39:17 +02:00
Pau Espin 8367411772 Power Control Loop: Set P_CON_INTERVAL to 1 by default
TS 45.008 section 4.7.1:
"""
Upon receipt of a command from an SACCH to change its power level on the corresponding uplink channel, the MS
shall change to the new level at a rate of one nominal 2 dB power control step every 60 ms (13 TDMA frames), i.e. a
range change of 15 steps should take about 900 ms. The change shall commence at the first TDMA frame belonging to
the next reporting period (as specified in subclause 8.4). The MS shall change the power one nominal 2 dB step at a
time, at a rate of one step every 60 ms following the initial change, irrespective of whether actual transmission takes
place or not.
"""

Since the reported MS_PWR in L1 SACCH Header is, according to specs, the
one used for the last block of the previous SACCH period, it becomes
clear the first SACCH block after a requested MS Power Level change by
the network may contain mismatches between the announced MS_PWR by the
MS and the measured Rxlev/RxQual. Hence, let's better use a
P_CON_INTERVAL of 1 which retriggers the MS Power Control Loop every second
SACCH block.

Related: SYS#5371
Change-Id: Iade5b597e0e56b07c6d78995fcec7c641e4e643f
2021-09-13 17:48:48 +02:00
Pau Espin 54283ba626 MS Power Control Loop: Support set up of C/I parameters for osmo-bts
This commit extends existing VTY and RSL infrastructure to configure and
manage MS Power Parameters used in MS Power Control loop, by adding
support to set up Carrier-to-Interference (CI) parameters.

Using C/I instead of existing RxQual is preferred due to extended
granularity of C/I (bigger range than RxQual's 0-7).
Furthermore, existing literature (such as "GSM/EDGE: Evolution and Performance"
Table 10.3) provides detailed information about expected target values,
even different values for different channel types. Hence, it was decided
to support setting different MS Power Parameters for different channel
types.

These MS Power Parameters are Osmocom specific, ie. supported only by
newish versions of osmo-bts. Older versions of osmo-bts should ignore
the new IEs added just fine. The new IEs containing the MS POwer
Parameters are not send for non osmo-bts BTSs, hence this commit is
secure with regards to running  osmo-bsc against an ip.access BTS such
as nanoBTS.

Related: SYS#4917
Depends: libosmocore.git Change-Id Iffef0611430ad6c90606149c398d80158633bbca
Change-Id: I7e76ec47b323d469f777624b74b08752d1f5584f
2021-09-06 12:07:20 +02:00
Pau Espin 32d917bec2 cosmetic: power_ctrl_params_def: Fix typo in comment
Change-Id: Ibbbb073fa674666f47d84d8e670790c4028ba874
2021-09-06 10:06:47 +00:00
Neels Hofmeyr 57af76cdcf introduce gsm48_lchan_and_pchan2chan_desc()
The function gsm48_lchan2chan_desc_as_configured() dups
gsm48_lchan2chan_desc() with merely a different pchan type
(ts->pchan_from_config instead of ts->pchan_is).

In an upcoming patch, I would like to do the same, just with yet another
pchan value (derived from lchan->type, because that reflects the channel
type even before a dynamic timeslot switched its pchan type).

So replace gsm48_lchan2chan_desc_as_configured() by
gsm48_lchan_and_pchan2chan_desc() with explicit pchan arg;
also call this from gsm48_lchan2chan_desc(), reducing code dup.

gsm48_lchan2chan_desc_as_configured() had more concise error logging.
Absorb that into the new gsm48_lchan_and_pchan2chan_desc().

Add gsm_lchan_and_pchan2chan_nr(), like gsm_lchan2chan_nr() just with
explicit pchan arg, to be able to pass the pchan down from the new
functions mentioned above.

Related: SYS#5559
Change-Id: I67f178c8160cdda1f2ab5513ac4f65c027d4012f
2021-08-16 00:12:12 +00:00
Pau Espin fc842fba24 Clarify string name for GSM_CHREQ_REASON_CALL
The previous naming was confusing since when appearing on log files it
seemed to mean the reason was mainly only call reestablishment, when it
actually means either call establishment (the usual reason) OR call
re-establishment (should happen seldomly).
Let's add some parenthesis to make it clearer.

Related: SYS#5548
Change-Id: Id2dccd71803335c284a5ba271fa7f7890d253c27
2021-07-29 14:40:26 +02:00
Pau Espin 52b9912ef9 Support SDCCH8 in osmo dyn ts
This feature signals support to configure Osmocom Dynamic Timeslot type
as SDCCH8, on top of historically supported TCH/H and TCH/F.
The idea is that when unneeded, the TS is configured as PDCH, and as
soon as there's need for an SDCCH and there's none available, the TS is
dynamically reconfigured to SDCCH8. Once all logical channels in the
dynamic TS are released and hence becomes free, the BSC will reconfigure
it to PDCH.

Related: SYS#5309
Depends: libosmocore.git Change-Id Ifc0ca8916bd3e93e5a60a7dd7391d2588fdb5532
Change-Id: I29ac8b90168dba3ac309daeb0b6cfdbbcb8e9172
2021-07-06 07:16:15 +00:00
Pau Espin cc75145131 Rename osmo dyn ts enums to contain SDCCH8
They will gain support to be activated as SDCCH/8 soon too.

Related: OS#5309
Depends: libosmocore.git I56dcfe4d17899630b17f80145c3ced72f1e91e68
Change-Id: Id5b89fe589a52ff88486435ac43809edb4b80f98
2021-07-06 07:16:15 +00:00
Neels Hofmeyr ee921cf903 VTY: add lchan re-assignment command
Add VTY command to trigger an intra-cell re-assignment, also allowing to
re-assign to a secondary VAMOS lchan.

Related: SYS#5315 OS#4940
Change-Id: If006f5caaf83b07675f57e5665cfa79328da55e6
2021-06-10 16:15:35 +02:00
Neels Hofmeyr d37dcb9f68 RSL: rx and tx VAMOS Channel Number cbits for VAMOS lchans
Add the Osmocom-specific extension to indicate VAMOS shadow lchans in
RSL, in lchan lookup and RSL message transmission.

Note that RR messages containing cbits (Assignment Command, Handover
Command, ...) must *not* send Osmocom specific cbits to the MS. Only the
RSL messages directed to the BTS send Osmocom specific bits.

Related: SYS#5315 OS#4940
Depends: If33c1695922d110c0d2c60d5c0136caf2587194e (libosmocore)
Change-Id: I957eff0d2c33ec795eda75a4bff21965b0179f73
2021-06-10 16:15:35 +02:00
Neels Hofmeyr 43aeeaf05a RSL chan_nr: replace OSMO_ASSERT with error handling
It's bad to abort the program for an incompatible chan_nr.  Instead of
OSMO_ASSERT(), make sure that error handling happens all they way to the
original callers of gsm_lchan2chan_nr etc.

This is also preparation to add further error causes: Osmocom specific
cbits needed for a non-Osmo BTS.

Related: SYS#5315 OS#4940
Change-Id: I71ed6437c403a3f9336e17a94b4948fca295d853
2021-06-10 16:15:35 +02:00
Neels Hofmeyr 426941e87f update the lchan name to always reflect VAMOS shadowness
Change gsm_lchan_name_compute() to a function that in-place updates the
lchan->name. That allows calling it numerous times with the talloc
handled internally. Rename it to lchan_update_name().

Add 'shadow' to lchan_update_name() and lchan_fsm_update_id() for VAMOS
shadow lchans, and also print the lchan index that it is a shadow for,
instead of the index in the lchan array.

When set_pchan_is() updates the VAMOSness of the lchans, call
lchan_fsm_update_id(). From lchan_fsm_update_id() also call
lchan_update_name().

This is a bit convoluted for legacy reasons. There are utility programs
and C tests using bts_trx.c but not lchan_fsm.c. lchan_update_name()
lives in gsm_data.c for that reason. This patch calls
lchan_update_name() from lchan_fsm_update_id() and not vice versa to
avoid having to add stubbed lchan_fsm_update_id() functions to all
utility programs and C tests.

We can't easily unify the lchan->name and lchan->fi->id without lots of
refactoring rippling through all those little utility programs and C
tests.

Change-Id: I7c2bae3b895a91f1b99b4147ecc0e3009cb7439a
2021-06-10 16:15:35 +02:00
Neels Hofmeyr d163aa3805 add VAMOS secondary lchans to timeslot struct
So far there is a bunch of code setting a primary lchan in VAMOS mode.
This patch now adds the actual secondary "shadow" lchans that may be
combined with a primary lchan in VAMOS mode to form a multiplex.

VAMOS lchans are put in the same ts->lchan[] array that keeps the
primary lchans. They are at most two additional usable lchans (for a
TCH/H shadow) added to either TCH/F or TCH/H.

Keeping these in the same array allows looping over all lchans easily.
The ts->max_primary_lchans indicates the index of the first VAMOS shadow
lchan.

Related: SYS#5315 OS#4940
Change-Id: I928af99498bba488d317693f3144d4fccbbe9af3
2021-06-10 16:15:35 +02:00
Vadim Yanitskiy cdaf3ec006 Make interference measurement parameters configurable
According to 3GPP TS 45.008, the BSS shall monitor the levels of
interference on its IDLE traffic channels.  The actual measurements
are performed in the BTS and then reported to the BSC over the
A-bis/RSL link(s) in RF RESource INDication messages.

3GPP TS 45.008 defines the following measurement parameters:

  * Intave: Interference Averaging period (see table A.1),
  * Interference level Boundaries (see table A.1).

Both parameters are sent to the BTS over the A-bis/OML, and can
now be configured via the VTY interface.  Only those BTS models
which 'speak' the OML protocol defined in 3GPP TS 52.021 will
actually get the configured parameters, others will keep using
the hard-coded parameters.

Change-Id: I99ebf57aac1f3ca7e0497c3b4f6b0738c6ed7e47
Related: SYS#5313, OS#1866
2021-06-04 19:42:43 +00:00
Neels Hofmeyr e24da2ef95 ensure chan_mode comparisons in non-VAMOS mode
Both VAMOS- and non-VAMOS speech modes should result in indentical voice
handling. So make sure that all chan_modes are converted to non-vamos
before comparing / evaluating in switch statements.

Change-Id: I791e7966b1f8eaa3299a8a46abeb313cf5136e0b
2021-05-31 05:20:03 +00:00
Neels Hofmeyr 5df7e771a8 gsm48_lchan2chan_desc(): expose TSC as param
Expose the training sequence code used in the RSL Channel Description IE
as an input parameter.

So far the Channel Description IE is always composed with a training
sequence code from gsm_ts_tsc(). For RSL commands enabling VAMOS mode,
specific training sequence codes are required.

So far, all callers still use gsm_ts_tsc(), making this a patch without
any functional change. Upcoming patches will pass specific TSC as
configured for VAMOS instead, in specific places.

Related: SYS#5315 OS#4940
Change-Id: I49503a6f5d25bb3bc9a0505bd79ed1d5c4f50577
2021-05-28 17:22:59 +00:00
Neels Hofmeyr 69def1f97e hodec 2: do intra-cell congestion resolution by Assignment
So far we do all channel reassignments by Handover Command. Since
osmo-bsc now supports rassignment of ongoing voice calls, do intra-cell
congestion resolution by Assignment Command.

In effect, add support for expecting an Assignment Command in
handover_test, and expect assignments instead of handovers for
intra-cell congestion resolution test cases.

Related: SYS#5330 OS#3277
Change-Id: Id56a890106b93fcee67ac9401b890e7b63bba421
2021-05-28 17:22:59 +00:00
Neels Hofmeyr 3625c90c22 eliminate lchan->rsl_cmode
Related: SYS#5315 OS#4940
Change-Id: I1c167b22bb6638a929488d093bde0f1a5fb227ad
2021-05-27 17:06:21 +02:00
Neels Hofmeyr 0951d75665 make sure channel mode and s15_s0 are updated only after an ACK
I noticed during testing that an lchan used as TCH/F in fact still had
its channel mode set to Signalling -- because on Assignment, the Speech
mode used to be placed in the *previous* lchan and the new lchan was
never updated after the Activ ACK. This is unbearable confusion which I
complained about numerous times, so far mostly for cosmetic reasons. But
implementing re-assignment properly actually requires this to be cleaned
up.

Keep all volatile chan mode settings in lchan->activate.* or
lchan->modify.*, and only update lchan->* members when an ACK has been
received for those settings. So a failed request keeps a sane state.

Make sure that those settings are in fact updated in the proper lchan,
upon an ACK, so that subsequent re-assignment or mode-modify know the
accurate lchan state.

Related are upcoming patches that sort out the AMR multirate
configuration in a similar fashion, see
Iebac2dc26412d877e5364f90d6f2ed7a7952351e
Ia7519d2fa9e7f0b61b222d27d077bde4660c40b9
Ie57f9d0e3912632903d9740291225bfd1634ed47.

Related: SYS#5315 OS#4940 OS#3787 OS#3833
Change-Id: Ie0da36124d73efc28a8809b63d7c96e2167fc412
2021-05-27 17:06:21 +02:00
Neels Hofmeyr 5234c64bd0 assignment_fsm: send BSSMAP response only after Assignment Request
So far, only the MSC asked for Assignment via Assignment Request, which
we answer with a BSSMAP Assignment Complete or Assignment Failure when
done.

When Assignment is triggered for any other reason (congestion
resolution, VAMOS, VTY), we will not send any such messages to the MSC.

Additional enum values will be added in subsequent commits:
Id56a890106b93fcee67ac9401b890e7b63bba421 ASSIGN_FOR_CONGESTION_RESOLUTION
If006f5caaf83b07675f57e5665cfa79328da55e6 ASSIGN_FOR_VTY

Related: SYS#5315 OS#4940
Change-Id: Ie0cddbdb00abcec78e153f4ae6d04ce75080a111
2021-05-27 15:01:57 +00:00
Neels Hofmeyr d5cb0eb8fd lchan and assignment FSMs: make Channel Mode Modify more sane
The Channel Mode Modify procedure is currently implemented for changing
a TCH lchan from signalling to voice mode. For that, however, it is
re-using (abusing) the channel activation structs and state transitions,
and thus always implies activating a voice stream when the mode
modification is done.

I will add a Channel Mode Modify to enable VAMOS mode soon, so I require
separate structs and state transitions which also work on an lchan that
already has a voice stream established: a struct lchan_modify_info and
LCHAN_EV_REQUEST_MODE_MODIFY, and dedicated assignment FSM state
ASSIGNMENT_ST_WAIT_LCHAN_MODIFIED.

For the part where a Channel Mode Modify enables a voice stream after
switching from signalling to speech mode, still use the channel
activation code path, but only once the mode modification is done.

General improvements:
- To ask for a mode modification, emit an FSM event that ensures a mode
  modify only happens when the lchan state allows it.
- The new lchan_modify_info struct reflects only those parts that have
  an effect during a mode modification (before the lchan_activate_info
  was fully populated, many values not having an effect).
- More accurate logging, indicating "Mode Modify" instead of "Channel
  Activation"

A TTCN3 test for the Channel Mode Modify procedure is added in
Idf4efaed986de0bbd2b663313e837352cc139f0f, and the test passes both
before and after this patch is applied.

Related: SYS#4895
Change-Id: I4986844f839b1c9672c61d916eb3d33d0042d747
2021-05-21 15:43:30 +02:00
Neels Hofmeyr 794e1281d8 cosmetic: rename FOR_* to ACTIVATE_FOR_*
Soon, there will also be enums with ASSIGNMENT_FOR_* and MODIFY_FOR_*
naming. Add the ACTIVATE_ prefix to the existing enum to clarify.

Change-Id: I12190d4d154a1da6a9ebc9a755ccc2fe382ff188
2021-05-21 15:43:30 +02:00
Neels Hofmeyr 730fc73bd2 comment: tweak pchan_subslots() description
Change-Id: I4d3ca6efc7b4fadd6711ae80502027cec1b7b84e
2021-04-28 16:32:19 +02:00
Neels Hofmeyr ef28721c16 gsm_lchan_name_compute with ctx
Use a talloc ctx directly without an intermediate static buffer.

A subsequent patch will add a name tweak for VAMOS secondary lchans, so
it felt appropriate to first clean this.

Change-Id: Idb922605c15242a2cdc7c34668c845a179a15660
2021-04-28 16:32:19 +02:00
Vadim Yanitskiy d2e0654ee4 gsm_data: return early if MS Power class remains the same
The following message makes no sense:

  DRLL DEBUG gsm_data.c:844 MS Power class update: 4 -> 4

because nothing really changed, MS Power class remains 4.  Neither
it makes sense to call lchan_update_ms_power_ctrl_level().

Change-Id: I519d2d1575cbb5352cc381a60513db8e0e2cb0a0
2021-01-15 22:55:48 +01:00
Vadim Yanitskiy f4674e3f7a power_control: fix swapped lower/upper RxQual threshold values
According to 3GPP TS 45.008, section A.3.2.1:

  c) Comparison of RXQUAL_XX with L_RXQUAL_XX_P (XX = DL or UL):

     Increase XX_TXPWR if at least P3 averaged values out of N3
     averaged values are greater (worse quality) than L_RXQUAL_XX_P.

  d) Comparison of RXQUAL_XX with U_RXQUAL_XX_P (XX = DL or UL):

     Decrease XX_TXPWR if at least P4 averaged values out of N4
     averaged values are lower (better quality) than U_RXQUAL_XX_P.

Given that RxQual is a value in range 0 .. 7, where 0 is the best
and 7 is the worst: L_RXQUAL_XX_P must define the worst quality,
while U_RXQUAL_XX_P must define the best quality value.

Change-Id: I0f37b23ed360782f3c1f4275234c4e18a17aa89b
Related: SYS#4918
2020-12-27 12:56:34 +00:00
Vadim Yanitskiy 53866d3bf7 power_control: add VTY command to set static / maximum BS Power
Change-Id: I11ca856aba46aaf84d94cbbdf4c39a01ee8289b9
Related: SYS#4918
2020-12-22 11:11:07 +00:00
Vadim Yanitskiy 8bde75c91d power_control: add new structures and default parameters
Change-Id: I7fb8ccb997490b40a061d09c241359aaabc37c4a
Related: SYS#4918
2020-12-19 22:54:48 +01:00
Pau Espin 64c422858d Store GPRS MOs directly under BTS SiteMgr object
The only real 1-1 relationship between BTS NM objects is the one between
GPRS Cell and BTS (which is actually a BTS cell).
In our current osmo-bts implementation we don't care much since we only
handle 1-cell BTSses, but let's make the data structure organization
more generic.

Implementation notes:
The gsm_bts_sm is moved to its own file, APIs to allocate are added and
the new public object is hooked correctly in the allocation process of
osmo-bsc.

Change-Id: I06461b7784fa2a78de37383406e35beae85fbad8
2020-12-03 16:31:36 +01:00
Pau Espin 12e15479d6 Set all NM OML objects to Locked by default
Before they were set with a value of 0, which had no related enum field,
but since in general all comparsions are done against NM_STATE_UNLOCKED
they also hold valid.

The major change in behavior with this patch is upon OML link down,
where gsm_bts_mo_reset() is called on all objects. This way, upon OML
re-establishment we have again all objects as Locked again, which is the
expected default value as per TS 12.21.

Change-Id: I68ae0bc51a565f903b47cf72f3e3dd6f1a2d2651
2020-10-15 05:55:36 +00:00
Neels Hofmeyr 4ae338d5b6 LCS: implement the bulk of Location Services
Depends: I4d7302a4853518916b6b425e710c10568eb2ffe5 (libosmocore)
Change-Id: I28314ba97df86a118497e9b2770e2e6e2484e872
2020-10-09 00:26:02 +02:00
Alexander Couzens cdfd687af4 gsm_data: always set spare bits in channel description
The spare bits were never encoded even when the spec says it must be 00.
Most caller of _chan_desc_fill_tail() initialized the struct with memset(),
but not all.
The SI4 did not initialize it.

Change-Id: Ib03d6d2cdadc49e49aa94917d17f81ef3c83f11c
2020-09-10 08:43:58 +00:00
Pau Espin aca53203d1 Move struct gsm_bts_trx: gsm-data.* => bts_trx.*
See rant fro similar recent commit moving stuff to bts.*.

Change-Id: I11758ca3d255d849d77bd068f24bb68bde1f89a5
2020-07-18 21:45:32 +00:00
Pau Espin e2f1c95774 bts: Drop duplicated function to get trx by number
In the big mess of gsm_data we reached a point where we have multiple
functions doing the same thing, most probably because it's hard finding
stuff in there. Let's drop one of them (the one which less callers) and
move it to bts.*, where it belongs.

Change-Id: I9071a0ab250844619280fbe2be63ed99f2c87eb1
2020-07-18 21:45:32 +00:00
Pau Espin 388ed58482 Move struct gsm_bts: gsm_data.* => bts.*
Place all code related to the object into the related file.

Having all the data model in one file made sense in early stage of
development to make progress quickly, but nowadays it hurts more than
helps, due to constantly growing size and more and more bits being
added to the model, gaining in complexity.

Currently, having lots of different objects mixed up in gsm_data.h is a hole
of despair, where nobody can make any sense were to properly put new stuff
in, ending up with functions related to same object in different files
or with wrong prefixes, declarations of non-existing functions, etc.
because people cannot make up their mind on strict relation to objects
in the data model.
Splitting them in files really helps finding code operating on a
specific object and helping with logically splitting in the future.

Change-Id: I00c15f5285b5c1a0109279b7ab192d5467a04ece
2020-07-18 21:45:32 +00:00
Neels Hofmeyr 3405c77282 propagate RSL error cause codes to RR Channel Release cause
In various places that receive an error cause from RSL and place it in
lchan.release.rsl_error_cause, translate it to an RR cause and place that in
the recently added lchan.release.rr_cause. Hence the RR Channel Release message
now reflects more specific error causes when the reason for the error was
received in an RSL message's cause value.

Change-Id: I46eb12c91a8c08162b43dd22c7ba825ef3bbc6ac
2020-07-16 12:03:19 +00:00
Neels Hofmeyr b523f54de4 RR Channel Release: pass Cause code from BSSMAP Clear to the BTS
In lchan.release, add 'cause_rr', and set RR Channel Release message's cause
value to lchan.release.cause_rr.

In lchan_release(), do not set lchan.release.rsl_error_cause to the RR cause
value, these are unrelated. Store in new lchan.release.cause_rr instead. The
rsl_error_cause is apparently only used for logging, except for one place in
lchan_fsm_wait_activ_ack() that compares it to RSL_ERR_RCH_ALR_ACTV_ALLOC, so
there should not be a functional difference by this fix.

Propagate the BSSMAP Clear Command cause to the RR Channel Release:

Add struct gscon_clear_cmd_data as event data for GSCON_EV_A_CLEAR_CMD -- so
far it sent the is_csfb flag, add the gsm0808_cause; invoking the event happens
in bssmap_handle_clear_cmd().

Adjust event handling in gscon_fsm_allstate(); there, pass the cause to
gscon_release_lchans(). In gscon_release_lchans(), pass the cause to
gscon_release_lchan(), and then lchan_release(), which sets the new
lchan.release.cause_rr to the passed cause value.

As soon as the lchan FSM enters the proper state, it calls
gsm48_send_rr_release(). There, set the cause value in the encoded message to
lchan.release.cause_rr.

Interworking with osmo-msc: so far, osmo-msc fails to set the Clear Command
cause code for normal release, it just passes 0 which amounts to
GSM0808_CAUSE_RADIO_INTERFACE_MESSAGE_FAILURE. Before this patch, osmo-bsc
always sent GSM48_RR_CAUSE_NORMAL in the RR Channel Release, and after this
patch it will receive 0 == GSM0808_CAUSE_RADIO_INTERFACE_MESSAGE_FAILURE from
osmo-msc and more accurately translate that to GSM48_RR_CAUSE_PROT_ERROR_UNSPC.
This means in practice that we will now see an error cause in RR Channel
Release instead of GSM48_RR_CAUSE_NORMAL when working with osmo-msc. For
changing osmo-msc to send GSM0808_CAUSE_CALL_CONTROL instead (which translates
to GSM48_RR_CAUSE_NORMAL), see OS#4664 and change-id
I1347ed72ae7d7ea73a557b866e764819c5ef8c42 (osmo-msc).

A test for this is in Ie6c99f28b610a67f2d59ec00b3541940e882251b
(osmo-ttcn3-hacks).

Related: SYS#4872
Change-Id: I734cc55c501d61bbdadee81a223b26f9df57f959
2020-07-16 12:03:19 +00:00
Pau Espin cce0ae11b6 Avoid selecting channels from administratively locked trx
Found while playing with "rf_locked 1" on a 2TRX setup with channel
allocator descend. After applying the setting, the 1st TRX is still used
to allocate the channels. After this patch is applied, the BSC correctly
allocates channels from TRX0.

Change-Id: I5201d2749363c9cbd0706177bde09117b163cbe3
2020-06-23 14:21:20 +00:00
Vadim Yanitskiy 6281d4f869 fix crashes due to OSMO_ASSERT(conn->lchan)
Starting from ttcn3-bsc-test-sccplite build #777, it was noticed
that osmo-bsc crashes with the following message:

  Assert failed conn->lchan include/osmocom/bsc/gsm_data.h:1376

The cause of this is a recently merged patch that calls conn_get_bts() during
assignment_fsm rate counter dispatch:
"Count assignment rates per BTS as well"
commit b5ccf09fc4
Change-Id I0009e51d4caf68e762138d98e2e23d49acc3cc1a

The root cause being that the assignment_fsm attempts to count an Assignment
event for a BTS after the lchan has already been released and disassociated
from the conn.

The assertion is found in conn_get_bts(), which is used in various places. In
fact, each caller is a potential DoS risk -- though most are in code paths that
are guaranteed to have an lchan and bts present, having an OSMO_ASSERT() on the
relatively volatile presence of an lchan is not a good idea for osmo-bsc's
stability and error resilience.

- Change conn_get_bts() to return NULL in the lack of an lchan.
- Adjust all callers of conn_get_bts() to gracefully handle a NULL return val.
- Same for cgi_for_msc() and callers, closely related.

Here is a backtrace:

  Program received signal SIGABRT
  pwndbg> bt
    0x0000555555be6e52 in conn_get_bts (conn=0x622000057160) at include/osmocom/bsc/gsm_data.h:1376
    0x0000555555c1edc8 in assignment_fsm_timer_cb (fi=0x612000060220) at assignment_fsm.c:758
    0x00007ffff72b1104 in fsm_tmr_cb (data=0x612000060220) at libosmocore/src/fsm.c:325
    0x00007ffff72ab062 in osmo_timers_update () at libosmocore/src/timer.c:257
    0x00007ffff72ab5d2 in _osmo_select_main (polling=0) at libosmocore/src/select.c:260
    0x00007ffff72abd2f in osmo_select_main_ctx (polling=<optimized out>) at libosmocore/src/select.c:291
    0x0000555555e1b81b in main (argc=3, argv=0x7fffffffe1b8) at osmo_bsc_main.c:953
    0x00007ffff6752002 in __libc_start_main () from /usr/lib/libc.so.6
    0x0000555555b61bbe in _start ()

In the case of the assignment_fsm counter, we now miss a chance to increase a
BTS counter for a failed Assignment, but this is a separate problem. The main
point of this patch is that osmo-bsc must not crash.

Related: OS#4620, OS#4619
Patch-by: fixeria
Tweaked-by: neels
Fixes: I0009e51d4caf68e762138d98e2e23d49acc3cc1a
Change-Id: Id681dfb0ad654bdb4b71805d1ad4f39a8bf6bbd1
2020-06-23 12:53:50 +00:00
Daniel Willmann 112609f918 osmo-bsc: Use designated initializer in bts_stat_desc
Change-Id: Ic29f3a7e6fb16955bc74cc163d45a243b373183a
2020-06-08 15:21:59 +02:00
Neels Hofmeyr bf4134edaf drop CC 'local-prefix' feature
It is not entirely clear to me what this used to do once, but I've stumbled
upon this before. By now I am certain that this is a non-standard legacy
feature. The BSC does *not* redirect connections during CC transactions.

Along with this, a bunch of legacy utility functions can be dropped. All of
this is unused code.

(Preparing for MSC pooling.)

Change-Id: Id54afe8ccf0e11b9121a733224054c9565eafb58
2020-05-29 20:16:40 +00:00
Alexander Chemeris 5d63827318 stats: Add counters and gauges for BORKEN lchans/TS
Now we can monitor the situation with the BORKEN lchans and TS in our
BTS's over time.

Change-Id: I427bbe1613a0e92bff432a7d76592fe50f620ebe
2020-05-19 20:00:32 +00:00
Alexander Chemeris 8b0f6879ed stats: Export connected OML/RSL links count per BTS.
Change-Id: I88c8025940a0eecb034b1c70f76ea17937fa0325
2020-05-09 12:26:06 +03:00