Before Handover is fully completed, the gscon remains in an INIT state. To send
back the BSSMAP Handover Complete message, use osmo_bsc_sigtran_send() directly
to not thwart the message due to the gscon state.
(The gscon state will change to ACTIVE right after that, once the handover FSM
is done.)
Change-Id: Ic48ae2bb23565015d5e2ccb56308fad09347b51a
If inter-BSC HO failed, the conn is by definition not in an active state, and
hence it makes no sense to verify the gscon FSM state before sending. Directly
call osmo_bsc_sigtran_send().
Change-Id: Ic49c94462041800674fa961c4d19c0c045bfe0c0
The API of a_reset.c is currently called with a pointer to struct
reset_ctx. This puts the responsibility of checking the presence of
msc->a.reset_fsm to the caller. It would be much more effective if the
caller would check if msc->a.reset_fsm before dereferencing it.
This also fixes at least one segfault that ocurrs when gscon_timer_cb()
is called but no sccp connection is present yet. Therefore the pointer
to bsc_msc_data would not be populated. This is now detected by
a_reset.c itsself.
- minor code cleanups
- call a_reset.c functions with msc (struct bsc_msc_data)
Change-Id: I0802aaadf0af4e58e41c98999e8c6823838adb61
Related: OS#3447
gsm0808_page() is just a thin wrapper for rsl_paging_cmd(), the only caller is
page_ms() from paging.c. Directly call rsl_paging_cmd() instead.
Move gsm0808_cipher_mode() to the only caller in osmo_bsc_bssap.c, make static.
Change-Id: Ib7ce026b52d4ba3e53a8b2824e74ea92432c48c5
Add FSMs:
- timeslot_fsm: handle dynamic timeslots and OML+RSL availability.
- lchan_fsm: handle an individual lchan activation, RTP stream and release,
signal the appropriate calling FSMs on success, failure, release.
- mgw_endpoint_fsm: handle one entire endpoint with several CI.
- assignment_fsm: BSSMAP Assignment Request.
- handover_fsm: all of intra, inter-MO and inter-MT handover.
Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing
the maximum amount events (32), and it is more logical to treat assignment,
handover and MGW procedures in separate FSMs.
- Add logging macros for each FSM type:
- LOG_TS()
- LOG_LCHAN()
- LOG_MGWEP(), LOG_CI()
- LOG_ASSIGNMENT()
- LOG_HO()
These log with the osmo_fsm_inst where present.
New style decision: logging without a final newline char is awkward,
especially for gsmtap logging and when other logs interleave LOGPC() calls;
we have various cases where the final \n goes missing, and also this invokes
the log category checking N times instead of once.
So I decided to make these macros *always* append a newline, but only if
there is no final newline yet. I hope that the compiler optimizes the
strlen() of the constant format strings away. Thus I can log with or without
typing "\n" and always get an \n termination anyway.
General:
- replace osmo_timers, state enums and program-wide osmo_signal_dispatch()
with dedicated FSM timeouts, states and events.
- introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def.
These can be used (with some macro magic) to define a state's timeout once,
and not make mistakes for each osmo_fsm_inst_state_chg().
Details:
bsc_subscr_conn_fsm.c:
- move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and
mgw_endpoint_fsm.
- There is exactly one state for an ongoing Assignment, with all details
handled in conn->assignment.fi. The state relies on the assignment_fsm's
timeout.
- There is one state for an ongoing Handover; except for an incoming Handover
from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn
are both established.
- move bssmap_add_lcls_status() to osmo_bsc_lcls.c
abis_rsl.c:
- move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in
abis_rsl.c
- reduce some rsl functions to merely send a message, rename to "_tx_".
- rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the
lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function.
- move all timers and error/release handling away into various FSMs.
- tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an
lchan passed, but just mode,type that they require. Rename to
ipacc_speech_mode*() and ipacc_payload_type().
- add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR
message received during BSSMAP Handover Command.
- move various logging to LOG_LCHAN() in order to log with the lchan FSM instance.
One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging
from DRR to DRSL. It might actually make sense to combine those categories.
- lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance.
- handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's
correct).
- gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during
inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS.
assignment_fsm.c:
- the Chan Mode Modify in case of re-using the same lchan is not implemented
yet, because this was also missing in the previous implementation (OS#3357).
osmo_bsc_api.c:
- simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to
lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv
twice, once by member assignment and then again with a memcpy.)
- During handover, we used to copy the MR config from the old lchan. Since we
may handover between FR and HR, rather set the MR Config anew every time, so
that FR rates are always available on FR lchans, and never on HR lchans.
Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore),
I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore)
Change-Id: I82e3f918295daa83274a4cf803f046979f284366
"utils" suggests thin helpers to aid using a proper API, while this .c file
actually *is* the proper RR API. Rename from "utils" to "rr".
Change-Id: I0ffff63d57f03cb324df8e40e41caea5b55a2c85
The vty option bts->codec-support allows the user to set the supported
codecs per BTS level. However, those values are currently only used to
make the handover decision but the logic that handles the BSSMAP
ASSIGNMENT REQUEST does not check those flags.
- Do not ignore bts->codec-support flags on BSSMAP ASSIGNMENT REQUEST
Change-Id: I285234e9c81de74d9fb9907fca2c443b08537435
Closes: OS#3361
At the moment there are three sources that may advertise a list of
supported audio codec/rate settings. There is the MS that advertises
advertises a speech codec list and the MSC that sends a channel type
information element over A and there are also settings in the bsc
configuration file that may restrict the codec/rate types that are
allowed to use.
The function match_codec_pref() looks at all of the three buckets and
selects a codec that satisfies all three. This is already a somewhat
complicated process, overit is very isolated, so lets give it its own
c-file.
Due to the lack of unit-tests it is very hard to make changes here so
lets add also unit-test to make sure that regressions are catched early.
- Put match_codec_pref() and all its helper functions into a separate
c-file.
- Add a unit test.
Change-Id: Iabedfdcec8b99a319f2d57cbea45c5e36c7b6e29
Related: OS#3361
If we receive a BSSMAP ASSIGNMENT REQ for a speech channel
containing only a CIC but no AoIP transport layer address, then that's
illegal and must be rejected.
In Change-Id If362a0084de452727cd063063dfb645eca2f9beb we re-introduced
accepting CIC-only ASSIGNMENT REQ, but we failed to verify that this
actually only happens over a SCCPlite A interface.
This fixes the BSC_Tests.TC_assignment_cic_only testcase.
Change-Id: Ia6e3897edca48b9f838ea69939d9b8be7185abf8
This code contains the following code:
* receive/parse/interpret LCLS specific BSSMAP IEs and PDUs
* osmo_fsm handling the various states and their transitions
* call leg correlation (finding the other subscr_conn with same GCR)
* communication between the two call-leg LCLS FSMs
* detection of supported / unsupported LCLS configurations
* display of GCR / LCLS information in "show conns"
* switch the media streams locally using MDCX to the MGW
Closes: OS#1602
Change-Id: I614fade62834def5cafc94c4d2578cd747a3f9f7
Also: Move mgcp_timeslot_to_port() next to it, as they are
more or less the inverse transformation of each other.
Change-Id: Ica908e2bb8fc4e59e0d146b428c93a9efc385688
The function a_reset_free() is not used anywhere at the code. The
reason for this is that a BSC instance is never cleared once it
is started up. Also the timer number is not according to the spec.
- Remove a_reset_free()
- Fix timer identification number (T4)
- use fi->priv to hold context info
- Fix sourcecode formatting
Change-Id: I72095d52304c520e383755eee6c889bce492cbd4
Related: OS#3102
We deliberately ignore errors from page_subscriber() so there is
no point in having a non-void return value.
Provide more context in the error message logged if paging failed.
Add a comment in an implementation override of base_grace_paging_request()
in the test suite to make return value semantics more clear.
Change-Id: Ie18c2ba53d2055d3eaff8c9ed939eb844af6dd2e
Related: I48f5efbcddd98e15256edfca06ba0ae6acb5bab1
In AMR-type cahnels, the gsm0808_speech_codec doesn't only include
the codec (like EFR/FR/AMR) but also the specific codec configuration,
i.e. the sub-set of AMR modes.
Hence, we cannot convert from a channel type (just the codec) to the
full gsm0808_speech_codec and then memcmp() that with the codec config
received from the MSC. Rather, we must only compare the *type*.
Change-Id: I0a3f362667a689135d5b62d151d491490dfd2976
Related: OS#3094
This error message suggested that parsing a cell identifier list
failed because the list was too short. While, in fact, this code
has no insight into the reason behind the parsing failure.
A generic error message is more appropriate.
Change-Id: I033747e2183984159f1505e772d7c9494b759058
Related: OS#3073
In the current implementation of osmo-bsc, the subscriber connection is
not handled (very) statefully. However, there is some state keeping in the
code that handles the mgcp connection, but there are still to much loose ends
which allow odd situations to happen, which then lead severe error situations
(see also closes tags at the end) This commit adds a number of improvements
to fix those problems.
- Use an osmo-fsm to control the gsm_subscriber_connection state and
make sure that certain operations can only take place at certain states
(e.g let connection oriented SCCP traffic only pass when an SCCP connection
actually exists.
Remove the old osmo_bsc_mgcp.c code. Use the recently developed MGCP client
FSM to handle the MGCP connections.
Also make sure that stuff that already works does not break. This in
particular refers to the internal handover capability and the respective
unit-tests.
See also OS#2823, OS#2768 and OS#2898
- Fix logic to permit assignment to a signalling channel. (OS#2762)
- Introduce T993210 to release lchan + subscr_conn if MSC fails to respond
The GSM specs don't have an explicit timer for this, so let's introdcue
a custom timer (hence starting with 99).
This timeout catches the following situation:
* we send a SCCP CR with COMPL_L3_INFO from the MS to the MSC,
* the MSC doesn't respond (e.g. SCCP routing failure, program down, ...)
The MS is supposed to timeout with T3210, 3220 or 3230. But the BSC
shouldn't trust the MS but have some timer on its own.
SCCP would have a timer T(conn est), but that one is specified to be
1-2min and hence rather long.
See also: OS#2775
- Terminate bsc_subscr_conn_fsm on SCCP N-DISC.ind from MSC
If the MSC is disconnecting the SCCP channel, we must terminate the FSM
which in turn will release all lchan's and other state.
This makes TC_chan_rel_hard_rlsd pass, see also OS#2731
As a side-effect, this fixes TC_chan_act_ack_est_ind_refused(),
where the MSC is answering with CREF to our CR/COMPL_L3.
- Release subscriber connection on RLL RELEASE IND of SAPI0 on main DCCH
The subscriber connection isn't really useful for anything after the
SAPI0 main signalling link has been released. We could try to
re-establish, but our best option is probably simply releasing the
subscriber_conn and anything related to it.
This will make TC_chan_rel_rll_rel_ind pass, see also OS#2730
This commit has been tested using the BSC_Tests TTCN3 testsuit and the
following tests were passed:
TC_chan_act_noreply
TC_chan_act_ack_noest
TC_chan_act_ack_est_ind_noreply
TC_chan_act_ack_est_ind_refused
TC_chan_act_nack
TC_chan_exhaustion
TC_ctrl
TC_chan_rel_conn_fail
TC_chan_rel_hard_clear
TC_chan_rel_hard_rlsd
TC_chan_rel_a_reset
TC_rll_est_ind_inact_lchan
TC_rll_est_ind_inval_sapi1
TC_rll_est_ind_inval_sapi3
TC_rll_est_ind_inval_sacch
TC_assignment_cic_only
TC_assignment_csd
TC_assignment_ctm
TC_assignment_fr_a5_0
TC_assignment_fr_a5_1_codec_missing
TC_assignment_fr_a5_1
TC_assignment_fr_a5_3
TC_assignment_fr_a5_4
TC_paging_imsi_nochan
TC_paging_tmsi_nochan
TC_paging_tmsi_any
TC_paging_tmsi_sdcch
TC_paging_tmsi_tch_f
TC_paging_tmsi_tch_hf
TC_paging_imsi_nochan_cgi
TC_paging_imsi_nochan_lac_ci
TC_paging_imsi_nochan_ci
TC_paging_imsi_nochan_lai
TC_paging_imsi_nochan_lac
TC_paging_imsi_nochan_all
TC_paging_imsi_nochan_plmn_lac_rnc
TC_paging_imsi_nochan_rnc
TC_paging_imsi_nochan_lac_rnc
TC_paging_imsi_nochan_lacs
TC_paging_imsi_nochan_lacs_empty
TC_paging_imsi_a_reset
TC_paging_counter
TC_rsl_drop_counter
TC_classmark
TC_unsol_ass_fail
TC_unsol_ass_compl
TC_unsol_ho_fail
TC_err_82_short_msg
TC_ho_int
Authors:
Harald Welte <laforge@gnumonks.org>
Philipp Maier <pmaier@sysmocom.de>
Neels Hofmeyr <neels@hofmeyr.de>
Closes: OS#2730
Closes: OS#2731
Closes: OS#2762
Closes: OS#2768
Closes: OS#2775
Closes: OS#2823
Closes: OS#2898
Closes: OS#2936
Change-Id: I68286d26e2014048b054f39ef29c35fef420cc97
This replaces custom cell identifier parsing in the paging code with
calls to the new cell identifier parser implementation in libosmocore
(which was derived from the code that is now being replaced here).
The bssap tests will fail unless this other change is merged to
libosmocore as well: https://gerrit.osmocom.org/#/c/7288/
Related: OS#2847
Change-Id: I9e2002fbbe135287e9ce09caa3f0a85a84529463
Depends: I7f3e8ace26176e9cbfe2542961d2a95662aa4d97
Add 3-digit flags and use the new RAI and LAI API from libosmocore throughout
the code base to be able to handle an MNC < 100 that has three digits (leading
zeros).
The changes to abis_test and gsm0408_test show that this code now handles
3-digit MNC correctly, by not dropping the leading zero as 0xf in the encoded
PLMN.
Re-implement CTRL commands 'mcc', 'mnc' and 'mcc-mnc-apply' to preserve the
presence of the third digit of the MNC. Always reply with all leading zeros.
Adjust the expected results in ctrl_test_runner.py, to show that it works.
In VTY and CTRL, the parsing of MCC and MNC is inherently made stricter by use
of osmo_{mcc,mnc}_from_str() -- they will no longer allow surplus characters
and detect errno returned by strtol() (in contrast to atoi()).
Depends: Id2240f7f518494c9df6c8bda52c0d5092f90f221 (libosmocore),
Ib7176b1d65a03b76f41f94bc9d3293a8a07d24c6 (libosmocore),
I020a4f11791c61742a3d795f782805f7b7e8733e (libosmocore)
Change-Id: I8e722103344186fde118b26d8353db95a4581daa
The rate counter BSC_CTR_PAGING_ATTEMPTED does not increment when
a paging request is sent to the BSC. The reson for this is that the
function call to rate_ctr_inc() is located in a dead code section.
- Move the function call to rate_ctr_inc() to osmo_bsc_bssmap.c.
incremanet on any paging attempt (valid or not) that is recived
on the A-Interface.
- Remove dead code from paging.c
Change-Id: Iec3eb6724bc655806c3ce3c28448069590d99f91
When the cell identifier list of the BSSMAP paging contains an
"No cell is associated with the transaction." entry then the
paging is dropped and no paging is started at all. This is not
correct. When no cell is associated, the BSS should page the
whole BSS instead.
- Replace respective error case with a paging request to all
bts.
Change-Id: Id85e3a7540bdc13cd0e780e7870f16c35c6a6a50
The BSSMAP Cause value should give a clear indication of why a given
operation failed. Previously we were unconditionally sending
GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE even in cases where mandatory
IEs were missing or other errors occurred unrelated to resource
availability.
Closes: OS#2759
Change-Id: I86adcae2950cbea6dcac4551cfde1054cb0abad1
So far, the administrator had to pick one particular cipher which
would then be used throughout all subscribers/phones. This is a bit
impractical, as e.g. not all phones support A5/3. Extend the VTY
command syntax in a backwards-compatible way to permit for multiple
ciphers.
The bit-mask of permitted ciphers from the MSC (sent in ASSIGNMENT
COMMAND) is intersected with the vty-configured mask a the BSC.
Finally, the best (highest) possible cipher is chosen.
Change-Id: I1d1c8131855bcab2392b4f27f6216bdb2fae10e0
Closes: OS#2461
There was always a 1:1 correspondence between gsm_subscriber_connection
and osmo_bsc_sccp_con, so there's really no point in having two separate
dynamically allocated data structures with pointers back and forth and
another linked list around.
Let's merge osmo_bsc_sccp_con into gsm_subscriber_connection for
simplicity.
The resulting code might not be elegant in places, but I've tried to
do only the most simple changes in this patch, while further
simplifications can be done in later subsequent patches.
As a side-effect, this patch also fixes lchan clearing if the MSC
(or the local SCCP provider) hard-disconnects the SCCP connection.
Change-Id: Idd2b733477ee90d24dec369755a00f1c39c93f39
On BSSMAP Assignment Request received from the MSC, store the Speech Codec List
in the subscr conn, so that we may evaluate available codecs during handover
decision. (Will be used, e.g., by handover_decision_2.)
Change-Id: I8222d73085eb777696e365c94214c05d56e6d129
The decision on how to further process the request depends significantly
on the contents of the only mandatory IE of the ASSIGNMENT REQ. Let's
decode it first.
Change-Id: I030b5ad6f4fc33da9155c8a6061fd982312b20fb
There's nothing wrong with passing the TLVP_VAL/TLVP_LEN directly into
the gsm0808 decoder functions, let's avoid variables that get assigned
and used only once - particularly with such generic names.
Change-Id: I8557b4a9ff4de28b76c7d618631a4700176a8669
This error message is now contained in a loop, and the current iteration
does not know whether paging will fail entirely or if later iterations
will succeed. Update the error message accordingly.
This also makes the error message consistent with the one in page_cgi().
Change-Id: I8ec229702343343dedcbb242b6d0ed170c858511
This is mostly no-op code refactoring which makes it easier to maintain the
code for each paging case and reduces the scope of several local variables.
Also, ensure that paging failures where no matching BTS was found are logged
consistently in all cases. The log level changes from ERROR to NOTICE since
this is not necessarily a fatal condition.
Change-Id: If8fdf425145791f4904a70e295bdc3c7d0f4d5f6
This is a simple combination of the LAC and CI cases which have
already been implemented.
The BSC_Tests.TC_paging_imsi_nochan_lac_ci ttcn3 test passes.
The switch statement in bssmap_handle_paging() is getting a bit large,
and scoping of local variables could be improved. I will focus on
cleaning this up later once paging functionality is complete.
Change-Id: If7f596663a97a1db1a00f115a366f4a5a271c127
Depends: Id83f8b3b1ce80a39417176d99fd09f3b394fd19c
Related: OS#2752
This is essentially a case which combines paging by LAI and CI.
Depends: Ic1c72c7f83e53988eb9fedf314b1dc459836833d
Change-Id: Id83f8b3b1ce80a39417176d99fd09f3b394fd19c
Related: OS#2751
We can now either page an invidual BTS directly or page several BTS in a
given location area. This decision is taken based on the contents of the
cell identifier list in the paging request. Select a set of BTS for paging
while processing the cell identifier list, rather than requiring the
paging layer to loop over all BTS in the MSC.
This change requires some adjustment in bssap_test. In particular,
this test must now add a BTS to its network in order to pass.
The purpose of this change is to make the layering a bit cleaner.
There is one functional change: We no longer abort paging if paging fails
for a particular BTS. Instead, we keep trying to page on other BTS.
Change-Id: Ic1c72c7f83e53988eb9fedf314b1dc459836833d
Suggested-by: Harald Welte
Depends: Ic7772e75c3d7fb0df6e17e118bb33b3248352d4d
Related: OS#2753
This builds upon https://gerrit.osmocom.org/#/c/5698/ which implements
support for paging by LAI.
The ttcn3 test TC_paging_imsi_nochan_ci passes with this code when
run in isolation. It does not pass if another paging test (such as
TC_paging_imsi_nochan_lai) is executed beforehand. This problem
looks similar to the scenario tested in TC_paging_imsi_a_reset.
Change-Id: Ic7772e75c3d7fb0df6e17e118bb33b3248352d4d
Depends: Ic3c62ff0fccea586794ea4b3c275a0685cc9326e
Related: OS#2753
This is a new inline function that hides all accesses to conn->bts.
A follow-up patch will then point this to conn->lchan->ts->trx->bts
to get rid of the bts field.
Change-Id: Ib6cf7097ced34eebe80441c29ab1534f21956a33
The OsmoBSC code contained a refcount leak on bsc_subscr in the paging
code. For every PAGING command received from the MSC we consistently
leaked one refcount, resulting in a resulting memory leak.
Change-Id: I3d0fb406ca2a1042c6c3424e0dd263c1933b0d50
Closes: OS#2780
Properly match up any A5/N with the MSC's list of permitted algos.
Properly set the reject cause in case of mismatching algorithm choices.
Actually allow choosing A5/1 thru 3 as configured on the VTY, by passing
a5_encryption through to gsm0808_cipher_mode() (instead of a hardcoded 1).
Properly handle failure rc of gsm0808_cipher_mode() by sending a reject
message.
Cosmetically clarify which GSM0808_IE_ENCRYPTION_INFORMATION bits mean what by
means of local variables; add some comments on expected encryption formats; add
comment that the BSC should be able to have more than one a5_encryption.
Related: OS#2745 OS#2755
Change-Id: Ide8a615905555e35be4584b458d4d40345686175
When the MSC has lost its state and issues a RESET, we should not only
clear all ongoing radio connections, but we should also stop any paging.
There's no point in paging a subscriber if the MSC doesn't know about
this paging anymore.
Change-Id: If3f53d3bb66ad2dc02db823cb813590c6b59c700
Closes: OS#2736
the functions mgcp_timeslot_to_endpoint() and rtp_calculate_port()
which are used to calculate the port in the sccp-lite / non AoIP
case are part of libosmo-legacy-mgcp. Unfortunately libosmo-mgcp
and libosmo-legacy-mgcp cause problems when used at the same
time.
Replace the functions mgcp_timeslot_to_endpoint() and rtp_calculate_port()
with a local helper function.
Change-Id: Id10311332aeabd8fd3ba1922198e34708e04cef9
Neels Hofmeyr
Philipp Maier
Harald Welte
Pau Espin