The assignment is triggered by the MSC by sending an ASSIGNMENT REQUEST
with a group call reference. The reference is used to find the VGCS/VBS
channel that belogs to the referenced call.
The existing VGCS/VBS channel is reactivated. This will put the channel
into a state where the MS can establish the link on it, to complete the
assignment. The old connection is released by the MSC and assignment
completion is handled by the VGCS FSM.
Change-Id: Idaa864cd5ce4df6c3193494ce12d91523c104d89
Related: OS#4852
Rename _gsm0808_ass_compl_extend_osmux() to gsm0808_extend_osmux().
This IE is also used for VGCS/VBS assignment command that is located in
a different file.
Change-Id: I1452cabb142f9e7a169f4ddfeac85908abaf8dfc
Related: OS#4852
User reports a SEGV:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 send_assignment_complete (conn=conn@entry=0x557dbabb75a0) at assignment_fsm.c:188
#1 0x0000557db66aa6b0 in assignment_success (conn=0x557dbabb75a0) at assignment_fsm.c:277
#2 0x00007f6007afee82 in _osmo_fsm_inst_dispatch (fi=0x557db9615b80, event=4, data=0x0, file=0x7f6007a7dc21 "mgcp_client_endpoint_fsm.c", line=513) at fsm.c:875
#3 0x00007f6007a78c12 in ?? () from /lib/x86_64-linux-gnu/libosmo-mgcp-client.so.9
version: osmo-bsc 1.9.0.111.fc339.202212220009
The situation apparently is conn->lchan == NULL (primary lchan is gone),
but Assignment has just concluded. Apparently an unexpected / orthogonal
event has interrupted operations.
During assignment_success(), do not assume that conn->lchan is still
present. This should normally be true, but if not, fail the assignment
procedure instead of crashing osmo-bsc.
Related: SYS#6382
Change-Id: I4db25d0458f620954a1ca345282f5d8316341919
Use the full gsm0808_chan_indicator value throughout the lchan related
structs (assignment_fsm_data, gsm_lchan, lchan_activate_info,
lchan_modify_info) instead of reducing it to the boolean
requires_voice_stream.
This is needed so we don't lose the information whether an lchan was
requested for data or speech (both need an rtp stream).
Add a new bsc_chan_ind_requires_rtp_stream function and use it in
conditionals like the previous requires_voice_stream.
Related: OS#4393
Change-Id: I1538c1e6d5cd61559af7c1e2860afd0269dda367
Replace check_requires_voice_stream, which used to iterate over
ch_mode_rate_list and verify that all entries are either for speech or
signalling. Instead verify in check_chan_mode_rate_against_ch_indctr,
that all entries of ch_mode_rate_list have a chan_mode that matches the
ch_indctr (data, speech, signalling; called "speech / data indicator" in
3GPP TS 48.008 § 3.2.2.11).
This ensures that all of them are either data, speech or signalling and
not mixed.
Related: OS#4393
Change-Id: Iee5cbfee84d7f2ad59ee2d5a19891a2b59bbafff
gsm_pchan_ids[] exists only to compose osmo_fsm compliant IDs. We do
have osmo_fsm_inst_update_id_f_sanitize() now, rather use that.
This removes some confusion about which value_string array has an effect
on the VTY command 'ts' / 'phys_chan_config'.
Note that tests/bsc_test.ok does not change, hence the new way of
composing FSM IDs is identical to using the old gsm_pchan_ids[].
Change-Id: Ib85b7aa4ea882ae37919dd3ea0c033e949c083e5
Show the timeslot_fsm, lchan_fsm, assignment_fsm fi->id strings.
The IDs include the current pchan configuration. I want to tweak the
composition of these in an upcoming patch, so the test should show
whether any FSM IDs change from that.
Change-Id: If369f23fa140b9d7792f5a511815cbbd14b371e9
I'm going to add a regression test that probes lchan_fsm. I noticed that
I have to call lchan_fsm_init() for osmo_fsm_register(). Let's make this
implicit as we usually do now, to not have to register FSMs in tests.
Change-Id: I58760e743c78a370aedc9720f265c0f8da5c2045
T23042 was a placeholder for timers to be filled in later. Replace it
with timers that can be configured via VTY.
Previous timeout for the states was 5s, from using the default of 5 for
undefined timers.
* ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC and
HO_ST_WAIT_MGW_ENDPOINT_TO_MSC:
* Runs gscon_connect_mgw_to_msc() on enter, which waits for one MGCP
CRCX or MDCX response (or changes state immediately)
* Use existing X9 ("Timeout for availability of MGW endpoint"), 5s,
which is already being used by lchan_rtp_fsm for a similar purpose
* HO_ST_WAIT_RR_HO_DETECT:
* Handover initiation as described in 3GPP TS 04.08 § 3.4.4.1:
"The network initiates the handover procedure by sending a HANDOVER
COMMAND message to the mobile station on the main DCCH. It then
starts timer T3103."
* Use existing but unused timer T3103 ("Handover"), 5s
* HO_ST_WAIT_RR_HO_COMPLETE:
* Handover completion as described in 3GPP TS 04.08 § 3.4.4.3:
"When receiving the HANDOVER COMPLETE message, the network stops
timer T3103 and releases the old channels."
* Continue using T3103 with keep_timer = true
Closes: OS#5787
Change-Id: Id0d4d0788f609f3272fc81c80a754383dde25c16
In send_assignment_complete(), obviously return the current channel
configuration from lchan->current_ch_mode_rate, which is the proper
place to get the channel mode after RSL Chan Activ Ack.
It is interesting to look at the history of this line of code.
lchan->current_ch_mode_rate was added later, so now the mistake is very
obvious.
Related: SYS#6229
Change-Id: I3bf8f5ea9ae2a3c12fc5b483818d550a069fe66e
Use spaces around equals signs inside structs, as expected from the
kernel coding style we mostly follow.
Neels wrote:
> IIUC "T=123" without spaces is my personal favorite that goes against
> the accepted linter standard, i guess rather than everyone else
> adapting to my weird style, i should start adding spaces in my
> patches.
Change-Id: I01ce986a1b0cdd74d945a04ae62a07f2850d366f
Unfortunately "-std=c99" is not sufficient to make gcc ignore cold that
uses constructs of earlier C standards, which were abandoned in C99.
See https://lwn.net/ml/fedora-devel/Y1kvF35WozzGBpc8@redhat.com/ for
some related discussion.
Change-Id: Ic92aa70d569778a776f4c5d24c455f71fd50b61b
It is really difficult right now to find out where all the different
stuff relative to operation and lifecycle of an lchan is. Let's move
everything to its own file to have all the related defines and logic
together.
Change-Id: Idd855d126c43ac6576c5f3ba7e0b8014127a65e1
This API has been available since 1.0.0, and we actually require
libosmocore >= 1.7.0 nowadays, so it's totally fine using the
libosmocore API and drops the local duplicate.
Change-Id: I95c59b31cf1b08e1d513b589ef386d2dd55f09a2
This change implements an additional channel allocation mode, which
can be employed during a TCH channel allocation for assignment.
Selection between ascending and descending order is performed
depending on pre-configured parameters:
* Uplink RxLev threshold and number of samples for averaging,
* C0 (BCCH carrier) channel load threshold.
This is useful in setups where Tx power of the RF carriers cannot be
adjusted +dynamically at run-time and thus BS Power Control cannot
be performed. In such setups the BCCH carrier is transmitting at
relatively higher power than the other RF carriers. The key idea
is to allocate channels in a smarter way, so that UEs with poor signal
would get channels on carriers with high Tx power, while UEs with good
signal could use carriers with lower Tx power.
Change-Id: I1b7a0d706976b73cc5c30a8714b830811addfe8d
Related: osmo-ttcn3-hacks.git Ia522f37c1c001b3a36f5145b8875fbb88311c2e5
Related: SYS#5460
A follow-up patch implements a special channel allocation mode, which is
only working for assignment (basically TCH selection for a voice call).
This mode cannot be employed for initial CHANNEL REQUEST or handover due
to the absence of an already established lchan.
Adding this mode to the existing VTY command syntax would be confusing:
channel allocator (ascending|desscending|dynamic)
^^^^^^^
so this patch extends the VTY syntax in a way that it becomes possible
to configure different channel allocator modes for different cases:
OsmoBSC(config-net-bts)# channel allocator mode ?
set-all Set a single mode for all variants
chan-req Channel allocation for CHANNEL REQUEST (RACH)
assignment Channel allocation for assignment
handover Channel allocation for handover
The old command syntax, which is basically 'set-all', is kept for
backwards compatibility, but marked as deprecated.
Change-Id: I3ae73b36ee9433cc768376b56f0765e5f416162f
Related: SYS#5460
Add missing conn->assignment.created_ci_for_msc to
gscon_forget_mgw_endpoint_ci().
Before this patch, when assignment.created_ci_for_msc lingers after a
DLCX, it can cause a use-after-free on assignment_reset(). Possible
scenario is rx BSSMAP Clear Cmd during ongoing Assignment.
In assignment_reset(), locally cache the ci pointer, because
gscon_forget_mgw_endpoint_ci() now NULLs created_ci_for_msc.
Related: OS#5572
Change-Id: If89610020f47fd6517081dd11b83911b043bd0f1
When the assignment succeeds, the assignment_request has taken effect
and whatever it requested should now be in effect.
Hence copy the new RTP information from the assignment_request to the
conn's storage indicating what is currently used, always, not only when
lchan_changed == true. The RTP information may have changed also from a
Mode Modify where the lchan stays the same but changes its mode of use,
e.g. from signalling to voice.
When there is no RTP involved, this data is zero or empty, so there is
no harm in copying it, always.
Related: SYS#5916
Change-Id: I0788d1f013b8f820f559b6ed58a5f9bb8a02e0b4
When the assignment fails, we roll back the MSC side RTP endpoint at the
MGW that may have been created before the failure occured. On success,
we clear the mgcp_ci pointer so it is not rolled back.
Always clear this, not only when lchan_changed == true. That is because
a channel Mode Modify may also have added a voice stream that should
retain the newly created RTP endpoint at the MGW.
If no voice stream is involved, the pointer should already be NULL.
There is no reason to have a condition for clearing this pointer.
Just always clear it.
This fixes all voice calls that modify a TCH lchan from signalling-only
to voice mode. Before this patch, their MSC side RTP endpoint was DLCX'd
right on assignment success.
In particular, this fixes Emergency Calls (which usually get a TCH lchan
assigned right from the start, and hence do a Mode Modify to add voice).
Related: SYS#5916
Change-Id: I5ab10ee7fd9c5d7608e8a06893881d990943feed
I find it weird that we store the A5 algorithm ID in a format that
is used on the wire: N + 1 (valid for both A-bis and A interfaces).
What confused me even more is that in some functions we print it
as if it was in a normal, human-readable format. And this is
also why one can see weird constructions like:
if (lchan->encr.alg_id > ALG_A5_NR_TO_RSL(0)) { ... }
Let's ensure that our internal structures use the A5/N format:
alg_id=0: A5/0 (0x01 on the A-bis/A interface)
alg_id=1: A5/1 (0x02 on the A-bis/A interface)
alg_id=2: A5/2 (0x03 on the A-bis/A interface)
...
alg_id=7: A5/7 (0x08 on the A-bis/A interface)
so that we can print and compare the value of alg_id without using
additional arithmetics. Let's also rename 'alg_id' to 'alg_a5_n'
as it most clearly indicates which representation it is storing.
This is how the above code snippet would look like:
if (lchan->encr.alg_a5_n > 0) { ... }
Change-Id: Ieb50c9a352cfa5481aebac2379e0a461663543ec
Counting the Assignment success after osmo_fsm_inst_term() meant that we
were counting a cleared out channel mode, which always yielded
signalling mode.
Count the Assignment success *before* terminating, so that we correctly
count the successful assignment as speech mode.
Related: SYS#4878
Related: Icb1386ec2ccd70eb3c026301b9b08ad7177278f7 (osmo-ttcn3-hacks)
Change-Id: Ie9fcd1e86f27ecb2f11e2e8813faac365cb470b8
From the nature of the lchan_activate_info.tsc_set and .tsc, it is easy
to forget to set tsc_set,tsc = -1 to use default TSC Set and TSC values.
Handover code is one such instance that forgets to set -1.
Change the semantics of tsc_set and tsc so that this kind of error can
not happen again as easily: use a separate bool to flag whether to use
the default config or explicit values.
Implicitly fix the lchan_activate_infos "launched" in handover_fsm.c as
well as abis_rsl_chan_rqd_queue_poll().
Related: OS#5244 SYS#4895
Related: I1ed6f068c85b01e5a2d7b5f2651498a1521f89af (osmo-ttcn3-hacks)
Change-Id: Iae20df4387c3d75752301bd5daeeea7508966393
When the SDCCH gets released while the TCH still beeing activated, then
the ChanActivACK that is received after the TCH is activated will trigger
a segmentation fault in the assignment_fsm. The reason for this is that
conn->lchan, which holds the SDCCH at that point in time, is now NULL.
To prevent osmo-bsc from crashing, the FSM should check for the presence
of conn->lchan first. If it does not exist, the FSM should terminate.
(Assignment failed)
Change-Id: I3b1cd88bea62ef0032f6c035bac95d3df9fdca7a
Related: SYS#5627
assignment_fsm_allstate_action is only used in module assignment_fsm.c,
so lets decalare it as static
Change-Id: I90d6c11bd485e3be80efc7f146e0129d93e18458
Instead of having static const structs in header files (which end up
duplicated in each and every compile unit!), have one .c file with the
rate_ctr and stat_item descriptions.
Related: SYS#5542
Change-Id: I8fd6380b5ae8ed2d3347e7cfbf674c30b6841ed9
Let's make sure the null pointer is caught by the assert if ever code
ends up here with conn->lchan being NULL.
Change-Id: I404df638da6a93caa535f10fd330ea24a775bfc3
Drop terminating newline from an assignment_fail() call which causes an
erratic line feed in logging.
Change-Id: Ib56e1f6a45c7e2c235f8ef0c8dea7151481677ab
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
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
lchan->activate.info.ch_mode_rate should remain unchanged, it is the
immutable request data. However, for VAMOS, we will want to
automatically see that the chan_mode is chosen correctly.
As a first step, place a mutable ch_mode_rate copy at
lchan->activate.ch_mode_rate, i.e. not in .activate.info, but in
.activate. Use that everywhere.
This is mostly a non-functional change, preparing for a subsequent patch
that adds handling of VAMOS shadow lchans.
As side effect of adding lchan_activate_set_ch_mode_rate_and_mr_config()
after MODE_MODIF_ACK (enabling the voice stream after a channel mode
modify), fix AMR config: the call to lchan_mr_config() was missing.
Change-Id: Icc9cc7481b3984fdca34eef49ea91ad3388c06fe
An unintended change in default behavior was introduced in patch:
"allow explixit TSC Set and TSC on chan activ / modif / assignment"
Ic665125255d7354f5499d10dda1dd866ab243d24
c33eb8d569
Set tsc_set and tsc = -1 for all lchan_activate_info and
assignment_request requests to actually yield the default behavior of
selecting the TSC based on the timeslot cfg or the BSIC value.
By setting tsc = 0 implicitly, the patch caused all requests to ask for
tsc 0 instead of calling gsm_ts_tsc().
For a Channel Mode Modify in assignment_fsm, pass the lchan's current
TSC to keep it unchanged.
osmo-ttcn3-hacks Id67a949e0f61ec8123976eb8d336f04510c55c01 adds a test
to verify the expected TSC in all of the activation, assignment and
modify messages. Current osmo-bsc master fails, this patch fixes.
Related: SYS#5315 OS#4940 Ic665125255d7354f5499d10dda1dd866ab243d24
Change-Id: If12df11511fe22ea167782f776736a1a9c484b1f
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
Activating / modifying to a VAMOS mode will require picking specific TSC
Set / TSC. It is a bad idea to pick the TSC in each message encoding
function, rather make this choice centrally.
So far we pick the training sequence code to use based on the timeslot
configuration, and this TSC is determined only upon encoding the RSL
messages.
Instead, pick the TSC to use upon the initial lchan activation /
modification request; store this in the request structs and pass through
the activation / modification code paths.
For VAMOS modes, we also need to pick a TSC Set. Do so also upon activ /
modif request. Note that the TSC Set is not yet applied in this patch,
it will be applied in upcoming VAMOS patches.
The activ / modif request may pass -1 for tsc_set and/or tsc to indicate
no specific choice of TSC Set and TSC, resulting in the same behavior as
before this patch.
For example, lchan->activate.info.tsc* may be passed as -1. The exact
choice for tsc_set and tsc is then stored in lchan->activate.tsc*, i.e.
one level up (the .info sub-struct is considered as immutable input
args). The lchan->activate.tsc* are the values actually encoded in RSL
messages. After the ACK, the lchan->activate.tsc* is stored in
lchan->tsc* to indicate the TSC actually in use. Same for modif.
Note that in 3GPP TS 45.002, the TSC Set are numbered 1 to 4, while the
TSC are numbered 0 to 7. On the wire, though, TSC Set is sent as 0 to 3
value. This is a weird discrepancy, odd choice made by the spec authors.
For conformance with the spec wording, I decided to pass the TSC Set
number as a 1-4 ranged value, and only convert it to the 0-3 on-the-wire
format upon message encoding. So log messages and VTY output will
indicate the first TSC Set as "1", but the first TSC as "0", as defined
in 3GPP TS 45.002, even if that is somewhat weird.
Related: SYS#5315 OS#4940
Change-Id: Ic665125255d7354f5499d10dda1dd866ab243d24
So far the assignment FSM always tried to satisfy the channel mode and
rate by either re-using the current lchan or finding a new, unused
lchan. For VAMOS however, we want to pick one specific lchan.
Add target_lchan to struct assignment_request and skip all mode matching
and lchan selection when a specific target_lchan is set.
Related: SYS#5315 OS#4940
Change-Id: I71e0d4ff4746706e0be5266e4574d70ca432e3d7
It is better design to take state change actions in the onenter
function, instead of triggering a state change and then calling
lchan_mode_modify() or lchan_activate(). The reason is that in
principle, any state change may cause error handling to abort and
deallocate FSMs.
This is also preparation for reassignment to a specific lchan in an
upcoming patch.
Related: SYS#5315 OS#4940 OS#3277
Change-Id: I9a2e7eefd4196b80671311e5dfd275893ec0e275
The single place that calls this special case is now actually doing the
exact same thing as the general case, and this is merely code dup.
Related: SYS#5315 OS#4940
Change-Id: Ic62e8a48d3c88a1966086240a41732d169328491
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
Andreas Eversberg
Oliver Smith
Neels Hofmeyr
Harald Welte
Pau Espin
Vadim Yanitskiy
Philipp Maier